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  • Public defence: 2025-04-22 13:15 Ada Lovelace, LinköpingOrder onlineBuy this publication >>
    Arvanitaki, Antonia
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Performance Analysis of Wireless Systems with Security Constraints2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Broadcast channels are fundamental components of wireless communication systems, extensively utilized in various applications such as the Internet of Things (IoT). However, security poses a significant concern in such networks due to their broadcast nature, making them vulnerable to unauthorized access and eavesdropping. Physical layer security, among other security measures, is crucial for enhancing the security posture of broadcast channels and is often integrated into cross-layer design approaches. Analyzing the performance of secure broadcast channels is a complex endeavor, compounded by several critical factors. Issues such as fading, interference from nearby transmissions, and path loss significantly influence key performance metrics like average packet delay and throughput. The consideration of bursty traffic remains largely unexplored in these systems. The utilization of traffic characteristics such as random arrivals can further improve the performance of those systems without sacrificing security.

    The main contribution of this thesis is addressing these factors in a holistic way for ensuring the efficient operation of broadcast channels. More specifically, proposing and studying congestion control policies as an effective strategy to manage packet transmission flow can mitigate the adverse effects of factors like interference and path loss on average packet delay. By maintaining a balanced transmission flow, congestion control policies help alleviate delays caused by channel impairments. Decoding schemes also play a pivotal role in optimizing network performance. Successive decoding, in particular, offers superior performance compared to treating interference as noise, leveraging higher-quality communication channels more effectively to improve overall network performance. Furthermore, adjusting packet transmission power based on channel conditions can help mitigate interference issues. Utilizing reinforcement learning techniques enables dynamic adjustment of transmission power, allowing the system to adapt to changing channel conditions and optimize performance accordingly. Addressing issues like interference, path loss, and packet delay is crucial for optimizing the performance of secure broadcast channels. By employing congestion control policies, optimizing decoding schemes, and leveraging reinforcement learning for power control, broadcasters can enhance network efficiency and security in various wireless communication applications.

    This thesis proposes an integrated approach to enhancing the performance and security of broadcast channels by addressing key performance bottlenecks. Unlike existing studies that focus separately on congestion control, decoding strategies, or power adaptation, we present a holistic framework that combines these techniques to mitigate interference, reduce packet delay, and optimize throughput. Specifically, we propose the use of congestion control policies to regulate packet transmission flow, thereby minimizing the impact of interference and path loss on latency. Additionally, we explore the benefits of successive decoding over conventional interference-as-noise approaches, demonstrating its ability to leverage high-quality communication channels for improved network efficiency. Finally, we introduce a reinforcement learning-based power control mechanism that dynamically adjusts transmission power in response to channel conditions, enabling adaptive interference mitigation and enhanced system performance.

    List of papers
    1. Delay Performance of a Two-User Broadcast Channel with Security Constraints
    Open this publication in new window or tab >>Delay Performance of a Two-User Broadcast Channel with Security Constraints
    2018 (English)In: 2018 GLOBAL INFORMATION INFRASTRUCTURE AND NETWORKING SYMPOSIUM (GIIS), IEEE , 2018Conference paper, Published paper (Refereed)
    Abstract [en]

    In this paper we consider the two-user broadcast channel with security constraints. We assume that one of the receivers has a secrecy constraint; i.e., its packets need to be kept secret from the other receiver. The receiver with secrecy constraint has full-duplex capability to transmit a jamming signal to increase its secrecy. We derive the average delay per packet and provide simulation and numerical results, where we compare different performance metrics for the cases when the legitimate receiver performs successive decoding and when both receivers treat interference as noise.

    Place, publisher, year, edition, pages
    IEEE, 2018
    Series
    Global Information Infrastructure and Networking Symposium, ISSN 2150-329X
    National Category
    Telecommunications
    Identifiers
    urn:nbn:se:liu:diva-155955 (URN)10.1109/GIIS.2018.8635694 (DOI)000461059500015 ()978-1-5386-7272-3 (ISBN)
    Conference
    Global Information Infrastructure and Networking Symposium (GIIS)
    Available from: 2019-04-01 Created: 2019-04-01 Last updated: 2025-03-20
    2. Delay Performance of a Two-User Broadcast Channel with Security Constraints
    Open this publication in new window or tab >>Delay Performance of a Two-User Broadcast Channel with Security Constraints
    2020 (English)In: SN Computer Science, ISSN 2661-8907, Vol. 1, no 1, article id 53Article in journal (Refereed) Published
    Abstract [en]

    In this paper, we consider the two-user broadcast channel with security constraints. We assume that a source broadcasts packets to two receivers, and that one of them has secrecy constraints, i.e., its packets need to be kept secret from the other receiver. The receiver with secrecy constraint has full-duplex capability, allowing it to transmit a jamming signal to increase its secrecy. We derive the average delay per packet and provide simulations and numerical results, where we compare different performance metrics for the cases when both receivers treat interference as noise, when the legitimate receiver performs successive decoding, and when the eavesdropper performs successive decoding. The results show that successive decoding provides better average packet delay for the legitimate user. Furthermore, we define a new metric that characterizes the reduction on the success probability for the legitimate user that is caused by the secrecy constraint. The results show that secrecy poses a significant amount of packet delay for the legitimate receiver when either receiver performs successive decoding. We also formulate an optimization problem, wherein the throughput of the eavesdropper is maximized under delay and secrecy rate constraints at the legitimate receiver. We provide numerical results for the optimization problem, where we show the trade-off between the transmission power for the jamming and the throughput of the non-legitimate receiver. The results provide insights into how channel ordering and encoding differences can be exploited to improve performance under different interference conditions.

    Place, publisher, year, edition, pages
    Springer, 2020
    Keywords
    Broadcast channel, Delay, Queueing, Security constraints
    National Category
    Telecommunications
    Identifiers
    urn:nbn:se:liu:diva-179795 (URN)10.1007/s42979-019-0055-3 (DOI)
    Available from: 2021-10-01 Created: 2021-10-01 Last updated: 2025-03-20Bibliographically approved
    3. Secrecy in Congestion-Aware Broadcast Channels
    Open this publication in new window or tab >>Secrecy in Congestion-Aware Broadcast Channels
    2021 (English)In: Proc. Wireless Days Conference (WD) 2021, Institute of Electrical and Electronics Engineers (IEEE), 2021Conference paper, Published paper (Refereed)
    Abstract [en]

    Congestion-aware scheduling in the case of traditional downlink cellular communication has neglected the heterogeneity in terms of secrecy among different clients. In this paper, we study a two-user congestion-aware broadcast channel with heterogeneous traffic and different security requirements. The traffic with security requirements is intended for a legitimate user and it has bursty nature. The incoming packets are stored in a queue at the source. Furthermore, there is a second traffic flow intended for another user, it is delay tolerant and does not have secrecy constraints. The receiver which needs to be served with confidential data has full-duplex capabilities, and it can send a jamming signal to hinder eavesdropping of its data at the other user. We consider two randomized policies for selecting which packets to transmit, one is congestion-aware by taking into consideration the queue size, whereas the other one is non-congestion-aware. We analyse the throughput and the delay performance under two decoding schemes at the receivers and provide insights into their relative security performance and into how congestion control at the queue holding confidential information can help decrease the average delay per packet. We show that the two policies have the same secrecy performance for large random access probabilities. The derived results also take account of the self-interference caused at the receiver for whom confidential data is intended due to its full-duplex operation while jamming the communication at the other user.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2021
    Keywords
    Broadcast channel; Delay; Queueing; Random access; Secrecy
    National Category
    Telecommunications Communication Systems
    Identifiers
    urn:nbn:se:liu:diva-180862 (URN)10.1109/WD52248.2021.9508287 (DOI)000701612800008 ()2-s2.0-85125385163 (Scopus ID)9781665425599 (ISBN)9781665425605 (ISBN)
    Conference
    Wireless Days Conference (WD), Paris, France, 30 June-2 July 2021
    Note

    Funding Agencies|Swedish Research Council (VR)Swedish Research Council; CENIIT; Indo-Sweden Project, Department of Science and Technology, India

    Available from: 2021-11-06 Created: 2021-11-06 Last updated: 2025-03-20Bibliographically approved
    4. Performance analysis of congestion-aware secure broadcast channels
    Open this publication in new window or tab >>Performance analysis of congestion-aware secure broadcast channels
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    2021 (English)In: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, Vol. 2021, no 1, article id 178Article in journal (Refereed) Published
    Abstract [en]

    Congestion-aware scheduling in case of downlink cellular communication has ignored the distribution of diverse content to different clients with heterogeneous secrecy requirements. Other possible application areas that encounter the preceding issue are secure offloading in mobile-edge computing, and vehicular communication. In this paper, we extend the work in Arvanitaki et al. (SN Comput Sci 1(1):53, 2019) by taking into consideration congestion and random access. Specifically, we study a two-user congestion-aware broadcast channel with heterogeneous traffic and different security requirements. We consider two randomized policies for selecting which packets to transmit, one is congestion-aware by taking into consideration the queue size, whereas the other one is congestion-agnostic. We analyse the throughput and the delay performance under two decoding schemes at the receivers, and provide insights into their relative security performance and into how congestion control at the queue holding confidential information can help decrease the average delay per packet. We show that the congestion-aware policy provides better delay, throughput, and secrecy performance for large arrival packet probabilities at the queue holding the confidential information. The derived results also take account of the self-interference caused at the receiver for whom confidential data is intended due to its full-duplex operation while jamming the communication at the other user. Finally, for two decoding schemes, we formulate our problems in terms of multi-objective optimization, which allows for finding a trade-off between the average packet delay for packets intended for the legitimate user and the throughput for the other user under congestion-aware policy.

    Place, publisher, year, edition, pages
    Springer, 2021
    Keywords
    Broadcast channel; Queueing; Congestion control; Secrecy; Multi-objective optimization
    National Category
    Communication Systems
    Identifiers
    urn:nbn:se:liu:diva-179849 (URN)10.1186/s13638-021-02046-7 (DOI)000699017600001 ()
    Note

    Funding Agencies|Linkoping University; CUGS (National Graduate School in Computer Science), IDA, Linkoping University

    Available from: 2021-10-05 Created: 2021-10-05 Last updated: 2025-03-20
    5. Deep Reinforcement Learning for Power Control in Secure Broadcast Channels
    Open this publication in new window or tab >>Deep Reinforcement Learning for Power Control in Secure Broadcast Channels
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    2023 (English)In: 2023 21st International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), 2023Conference paper, Published paper (Refereed)
    Series
    International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), ISSN 2690-3334, E-ISSN 2690-3342
    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:liu:diva-208863 (URN)10.23919/WiOpt58741.2023.10349852 (DOI)2-s2.0-85184655790 (Scopus ID)9783903176553 (ISBN)9798350341584 (ISBN)
    Conference
    WiOpt Workshop on Machine Learning in Wireless Communications (WMLC @WiOpt), Singapore, 24-27 August 2023
    Funder
    Swedish Research CouncilELLIIT - The Linköping‐Lund Initiative on IT and Mobile CommunicationsEU, Horizon Europe, 101096526
    Available from: 2024-10-27 Created: 2024-10-27 Last updated: 2025-03-20Bibliographically approved
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  • Public defence: 2025-04-23 13:15 ACAS, A-building, LinköpingOrder onlineBuy this publication >>
    Hyvärinen, Jari
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering.
    Efficient Fluid Structure Interaction Analysis in the Conceptual Design Phase: Industrially Proven and Validated Unique Methodology based on Aerospace Concepts2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aircraft flutter failure, vibration induce fan explosions, and vibration induced failure of tubes, pipes, and hoses subjected to internal and/or external axial flow showing fatigue type failure. These are all examples of aeroelastic or more generally fluid-elastic stability and response problems with the systems. The aim with this thesis is to illustrate the possibilities that opens when a frequency domain approach to the solution of fluid-elastic problems is utilized. A methodology of this type was developed in the first phase of the research leading to this thesis. The basic methods for aircraft aeroelastic analysis started to appear a few years before the second world war, and was further developed during the post second world war era. In this research the methodology used in the aeronautical community has been generalized, such that the early type of thinking can be used when studying more or less any type of system (in which the interaction between fluids and structures has a significant influence on it’s dynamic characteristics).

    This thesis presents the study of these type of phenomena for several applications. The presented applications range from investigations of the cause of failure of ventilation fans to the study of the dynamics of high pressure hydraulic hoses. In all case, results are presented from studies where the analysis is either compared with experimental behavior, or where the results are used as guidance for design changes followed by tests of the updated design showing dramatic improvement of the dynamic behavior. The purpose of presenting the application case studies is to give the reader an insight into how the tools can be used and the type of phenomena that appear for these fluid-elastic systems. It is clearly illustrated that fluid-elastic systems need to be analyzed through the entire function envelop of the system and not only at specific conditions. The reason for this is that unwanted instability conditions may appear anywhere in the envelop. To be able to scan the envelop much more efficient tools are needed than the ones provided through coupling of ALE-CFD and FEM software. By reading this thesis, the analyst gets an eye opener and a first step into an interesting field of engineering that is fairly unexplored outside the aeronautical community.

    List of papers
    1. An Arbitrary Lagrangian-Eulerian finite element method
    Open this publication in new window or tab >>An Arbitrary Lagrangian-Eulerian finite element method
    1998 (English)In: Computational Mechanics, ISSN 0178-7675, E-ISSN 1432-0924, Vol. 21, no 1, p. 81-90Article in journal (Refereed) Published
    Abstract [en]

    This paper describes an Arbitrary Lagrangian- Eulerian (ALE) finite element method for the simulation of fluid domains with moving structures. The fluid is viscous, incompressible and unsteady and the fluid motion is solved by a fractional step discretization of the Navier-Stokes equations. The emphasis is on convection dominated flows, and a three-step method is used for the convection term. The moving structure causes the mesh of the fluid domain to move, and a new algorithm is proposed to solve the important and crucial problem of the calculation of the mesh velocities.

    Place, publisher, year, edition, pages
    Springer Nature, 1998
    Keywords
    Convection, Reynolds Number, Finite Element Method, Circular Cylinder, Convection Term
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:liu:diva-211773 (URN)10.1007/s004660050285 (DOI)
    Available from: 2025-02-21 Created: 2025-02-21 Last updated: 2025-02-21Bibliographically approved
    2. Aeroelasticity - the interplay between fluids and solids
    Open this publication in new window or tab >>Aeroelasticity - the interplay between fluids and solids
    2001 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 11, no 4Article in journal (Refereed) Published
    Abstract [en]

    Many MEMS devices rely on the interaction between fluids and solids, e.g. pumps. To optimize such devices, it is essential to be aware of the general characteristics of this aeroelastic interaction. An essential part of an aeroelastic analysis is the efficient and accurate prediction of the steady and unsteady fluid dynamics. The difference between the presented approach based on LINFLOW and ANSYS, and that used in classical aeronautical tools for aeroelastic analysis is discussed. This paper also uses the proposed procedure to discuss in a general manner some aeroelastic effects. The results of the analysis are successfully compared with measurements for micromachined watch crystals, in air and water.

    Place, publisher, year, edition, pages
    Institute of Physics (IOP), 2001
    National Category
    Vehicle and Aerospace Engineering
    Identifiers
    urn:nbn:se:liu:diva-211777 (URN)10.1088/0960-1317/11/4/323 (DOI)
    Available from: 2025-02-21 Created: 2025-02-21 Last updated: 2025-02-21Bibliographically approved
    3. Flexible-Wall Turbulence Control for Drag Reduction on Streamlined and Bluff Bodies
    Open this publication in new window or tab >>Flexible-Wall Turbulence Control for Drag Reduction on Streamlined and Bluff Bodies
    2008 (English)In: Session: FC-15: Turbulence and Transition Control, American Institute of Aeronautics and Astronautics , 2008Conference paper, Published paper (Refereed)
    Abstract [en]

    A passive Flexible Composite Surface Deturbulator tape has been found capable of eliminating all skin-friction on streamlined bodies and minimize form drag on complex bluff bodies by suppressing turbulence in separated shear layers. The periodic ridged substrate of an optimized Deturbulator mitigates turbulence producing vortices by breaking long wavelength flow induced oscillations of the flexible surface. Preliminary aeroelastic analysis of the Deturbulator using LINFLOW software has identified combinations of structural modes which create conditions for extracting turbulent energy from the flow.

    Place, publisher, year, edition, pages
    American Institute of Aeronautics and Astronautics, 2008
    Series
    Fluid Dynamics and Co-located Conferences
    Keywords
    Aerodynamic Characteristics, Turbulence, Boundary Layer Separation, Adverse Pressure Gradient, Vortices, Calibrated Airspeed, Low Speed Wind Tunnel, Separated Flows, Velocity Profiles, Skin Friction Drag
    National Category
    Fluid Mechanics
    Identifiers
    urn:nbn:se:liu:diva-211778 (URN)10.2514/6.2008-4207 (DOI)9781600869945 (ISBN)
    Conference
    4th Flow Control Conference 3 June 2008 - 26 June 2008 Seattle, Washington
    Available from: 2025-02-21 Created: 2025-02-21 Last updated: 2025-02-21Bibliographically approved
    4. Study of concept for hydraulic hose dynamics investigations to enable understanding of the hose fluid-structure interaction behavior
    Open this publication in new window or tab >>Study of concept for hydraulic hose dynamics investigations to enable understanding of the hose fluid-structure interaction behavior
    2020 (English)In: Advances in Mechanical Engineering, ISSN 1687-8132, E-ISSN 1687-8140, Vol. 12, no 4, article id 1687814020916110Article in journal (Refereed) Published
    Abstract [en]

    Fatigue failure of a hydraulic hose systems, caused by violent vibrations, has become a critical factor creating operational and maintenance cost for the end user of rock drill equipment. Similar behavior is also appearing in, for example, forestry machines. Hoses are used as parts of the energy feeding system in machines such as the ones use for mining and civil construction operations. This work aims to create an understanding of the dynamic behavior of a selected hydraulic hose. The numerical modeling approach selected includes a boundary element method approach in the fluid-elastic analysis of the dynamics of a pressurized hose with conveying fluid. Experimental modal analysis was used to validate the numerical model. Pre-tension and pressure-induced tension were monitored with an in-house-developed strain gauge-based load cell. The analysis and experiments show that a complex coupling, of pure structural bending modes, appears when the hose is subjected to internal flow. Some of the modeshapes show a circular motion of the hose cross sections. As shown in this article, these coupled modes become increasingly sensitive to external or internal excitation with increasing flow rate. To illustrate the strength of the proposed approach, the second part of the work in this article presents a parametric study of hose dynamics for hoses with typical dimensions used in industrial applications. This investigation of how different parameters influence the dynamic characteristics of hydraulic hoses shows, for example, that hose end-support stiffness has a large impact on the stability and dynamic behavior of the hose. A soft support tends to create a static instability-type behavior where the lowest frequency mode frequency decreases to levels close to zero with increasing flow speed. Pre-tension of the hose has a stabilizing effect on the hose dynamics. In the case when the internal pressure of the hydraulic hose does not generate tension of the hose, then the increase or decrease in the internal pressure has limited influence on the hose dynamics: this is at least a conclusion valid in the investigated 100-210 bar pressure range. In addition, a smaller diameter hose is more sensitive than a larger diameter hose, and this is valid as long as the pre-tension is high enough to maintain static stability in the entire flow rate range.

    Place, publisher, year, edition, pages
    SAGE PUBLICATIONS LTD, 2020
    Keywords
    Dynamics; fluid-structure; stability
    National Category
    Other Materials Engineering
    Identifiers
    urn:nbn:se:liu:diva-165654 (URN)10.1177/1687814020916110 (DOI)000528902800001 ()
    Note

    Funding Agencies|Linkoping University

    Available from: 2020-05-11 Created: 2020-05-11 Last updated: 2025-02-21
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  • Public defence: 2025-04-25 09:00 Aulan, JönköpingOrder onlineBuy this publication >>
    Bruhn, Helena
    Linköping University, Department of Biomedical and Clinical Sciences, The Division of Cell and Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    PROGNOSTIC FACTORS FOR GLIOBLASTOMA SURVIVAL IN A CLINICAL CONTEXT: The role of presenting symptoms and treatments2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Glioblastoma is the most common and most malignant primary brain tumour. Survival is short, only around 15 months. This thesis explores factors influencing survival time.

    The first article showed that survival was significantly prolonged in the County of Jönköping, after the implementation of a new treatment regimen in 2006. In this regimen, patients receive chemotherapy and radiotherapy concomitantly, over six weeks followed by adjuvant chemotherapy given every four weeks over six months. The study shows that survival was prolonged by 110 days.

    For the second article, a review of patient records of all 189 glioblastoma patients diagnosed in the County of Jönköping 2001-2016 was performed. Patients with cognitive impairment were more difficult to diagnose, had larger tumours, and survived four months shorter than patients without cognitive impairment. If epileptic seizures were the presenting symptom, the tumours were found to be smaller at the time of diagnosis and patients lived three months longer than patients with no seizures at onset.

    To further explore the difference in survival for patients with different presenting symptoms the Swedish Brain Tumour Registry (SBTR) was used in the third paper. Using the SBTR, we analysed 1458 glioblastoma patients diagnosed between 2018 and 2021. Cognitive impairment was linked to significantly shorter survival—even after adjusting for age, performance status, tumour size, MGMT methylation, surgical resection grade, and oncological treatment—while epileptic seizures initially appeared beneficial on univariate analysis but lost significance after adjustment.

    The fourth study analysed 7669 glioblastoma patients from SBTR (1999–2023). Survival has improved across all age groups, almost all treatments, and regions, and analysis of relative survival demonstrated that patients primarily died from their brain tumour rather than other causes. Although initial data showed regional differences in survival, these differences diminished after adjusting for demographic data (age and sex) and tumour-related factors (preoperative performance status, tumour size), highlighting the need to control for such factors when comparing treatment outcomes between hospitals, regions and countries.

    In summary, this thesis shows that while glioblastoma survival has improved over time, the overall prognosis remains poor. Patients presenting with cognitive dysfunction have a significantly shorter survival—even after adjusting for age, tumour size, and treatment—which is a novel finding. These patients are also less likely to receive oncological treatment, likely due to concerns about their understanding and ability to cope with therapy. Although earlier studies suggested that epileptic seizures at presentation were a positive prognostic factor, our larger study indicates that this association is explained by other factors. Finally, we confirm the prognostic impacts of age, tumour size, preoperative performance status, MGMT promoter methylation status (in patients treated with alkylating agents), extent of surgery, and oncological treatment.

    List of papers
    1. Improved survival of Swedish glioblastoma patients treated according to Stupp
    Open this publication in new window or tab >>Improved survival of Swedish glioblastoma patients treated according to Stupp
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    2018 (English)In: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 138, no 4, p. 332-337Article in journal (Refereed) Published
    Abstract [en]

    ObjectivesThe median survival in glioblastoma (GBM) patients used to be less than 1year. Surgical removal of the tumor with subsequent concomitant radiation/temozolomide (the Stupp regimen) has been shown to prolong survival. The Stupp protocol was implemented in the county of Jonkoping in 2006. The purpose of this study was to examine if the Stupp treatment has prolonged overall survival, in an unselected patient cohort with histologically verified GBM. Material and MethodThis study includes all patients from the county of Jonkoping, with a diagnosis of GBM from January 2001 to December 2012. Patients were divided into 2 cohorts, 2001-2005 and 2006-2012, that is before and after implementation of the Stupp regimen. By reviewing the medical case notes, the dates of the histological diagnosis and of death were identified. The median and mean overall survival and Kaplan-Meier survival analysis were calculated and compared between the 2 cohorts. ResultsThe mean survival was 110days longer in the cohort treated according to the Stupp regimen. Four patients in the 2006-2012 cohort and 1 patient in the 2001-2005 cohort are still alive. When comparing survival in patients with radical surgery vs biopsy, those that underwent radical surgery survived longer. The significance was slightly greater in the 2001-2005 cohort (mean 163 vs 344days, Pamp;lt;.001) than in the 2006-2012 cohort (mean 220 vs 397days, P=.02). ConclusionSurvival significantly improved after the implementation of the Stupp regimen in the study region of Sweden.

    Place, publisher, year, edition, pages
    WILEY, 2018
    Keywords
    glioblastoma; mortality; radiotherapy; Stupp treatment; survival; temozolomide
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-151465 (URN)10.1111/ane.12966 (DOI)000443931400010 ()29882211 (PubMedID)
    Note

    Funding Agencies|Gustav Lindholms Stiftelse for elakartade hjarntumorer; Futurum

    Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2025-03-26
    2. Initial cognitive impairment predicts shorter survival of patients with glioblastoma
    Open this publication in new window or tab >>Initial cognitive impairment predicts shorter survival of patients with glioblastoma
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    2022 (English)In: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 145, no 1, p. 94-101Article in journal (Refereed) Published
    Abstract [en]

    Objectives Seizures as presenting symptom of glioblastoma (GBM) are known to predict prolonged survival, whereas the clinical impact of other initial symptoms is less known. Our main objective was to evaluate the influence of different presenting symptoms on survival in a clinical setting. We also assessed lead times, tumour size and localization. Methods Medical records of 189 GBM patients were reviewed regarding the first medical appointment, presenting symptom/s, date of diagnostic radiology and survival. Tumour size, localization and treatment data were retrieved. Overall survival was calculated using Kaplan-Meier and Mann-Whitney U test. Cox regression was used for risk estimation. Results Cognitive impairment as the initial symptom was often misinterpreted in primary health care leading to a delayed diagnosis. Initial global symptoms (66% of all patients) were associated with reduced survival compared to no global symptoms (median 8.4 months vs. 12.6 months). Those with the most common cognitive dysfunctions: change of behaviour, memory impairment and/or disorientation had a reduced median survival to 6.4 months. In contrast, seizures (32%) were associated with longer survival (median 11.2 months vs. 8.3 months). Global symptoms were associated with larger tumours than seizures, but tumour size had no linear association with survival. The setting of the first medical appointment was evenly distributed between primary health care and emergency units. Conclusion Patients with GBM presenting with cognitive symptoms are challenging to identify, have larger tumours and reduced survival. In contrast, epileptic seizures as the first symptom are associated with longer survival and smaller tumours.

    Place, publisher, year, edition, pages
    Wiley, 2022
    Keywords
    cognitive functions; epilepsy; glioblastoma; neuro-oncology; radiation; seizures; survival; temozolomide
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-179431 (URN)10.1111/ane.13529 (DOI)000695135800001 ()34514585 (PubMedID)
    Note

    Funding Agencies|Gustav Lindholm Foundation for malignant brain tumours

    Available from: 2021-09-23 Created: 2021-09-23 Last updated: 2025-03-26
    3. Do presenting symptoms predict treatment decisions and survival in glioblastoma? Real-world data from 1458 patients in the Swedish brain tumor registry
    Open this publication in new window or tab >>Do presenting symptoms predict treatment decisions and survival in glioblastoma? Real-world data from 1458 patients in the Swedish brain tumor registry
    2024 (English)In: Neuro-Oncology Practice, ISSN 2054-2577, E-ISSN 2054-2585, Vol. 11, no 5, p. 652-659Article in journal (Refereed) Published
    Abstract [en]

    Background Glioblastoma is the most common malignant brain tumor in adults. Non-invasive clinical parameters could play a crucial role in treatment planning and serve as predictors of patient survival. Our register-based real-life study aimed to investigate the prognostic value of presenting symptoms. Methods Data on presenting symptoms and survival, as well as known prognostic factors, were retrieved for all glioblastoma patients in Sweden registered in the Swedish Brain Tumor Registry between 2018 and 2021. The prognostic impact of different presenting symptoms was calculated using the Cox proportional hazard model. Results Data from 1458 adults with pathologically verified IDH wild-type glioblastoma were analyzed. Median survival time was 345 days. The 2-year survival rate was 21.5%. Registered presenting symptoms were focal neurological deficits, cognitive dysfunction, headache, epilepsy, signs of raised intracranial pressure, and cranial nerve symptoms, with some patients having multiple symptoms. Patients with initial cognitive dysfunction had significantly shorter survival than patients without; 265 days (245-285) vs. 409 days (365-453; P < .001). The reduced survival remained after Cox regression adjusting for known prognostic factors. Patients presenting with seizures and patients with headaches had significantly longer overall survival compared to patients without these symptoms, but the difference was not retained in multivariate analysis. Patients with cognitive deficits were less likely to have radical surgery and to receive extensive anti-neoplastic nonsurgical treatment. Conclusions This extensive real-life study reveals that initial cognitive impairment acts as an independent negative predictive factor for treatment decisions and adversely affects survival outcomes in glioblastoma patients.

    Place, publisher, year, edition, pages
    OXFORD UNIV PRESS, 2024
    Keywords
    cognition; glioblastoma; prognostic factors; survival; symptoms
    National Category
    Neurology
    Identifiers
    urn:nbn:se:liu:diva-204362 (URN)10.1093/nop/npae036 (DOI)001234683600001 ()2-s2.0-85199031357 (Scopus ID)
    Note

    Funding Agencies|Swedish Brain Tumour Registry; National Cancer Foundation; Cancer Foundation Northern Sweden; Futurum Academy for Health and Care

    Available from: 2024-06-12 Created: 2024-06-12 Last updated: 2025-03-26Bibliographically approved
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  • Public defence: 2025-04-25 10:00 Planck, LinköpingOrder onlineBuy this publication >>
    Balachandran, Arvind
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.
    Design, Modulation, and Control of Battery-Integrated Modular Multilevel Converters for Automotive Applications2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A critical component of a battery electric vehicle (BEV) is the battery pack, which has many series- and parallel-connected electrochemical cells. The total power, energy delivered, and lifetime of the battery pack are limited by the weakest cell in the pack. Battery-integrated modular multilevel converters (BI-MMC) can overcome this limitation by increasing cell-level control. BI-MMCs have several series-connected DC-to-AC converters with a battery module having a few series- and parallel-connected cells called submodules (SM). The research in this thesis focuses on the design, modulation, and control of BI-MMCs.

    The efficiency and adaptability of five basic BI-MMC topologies with half-bridge and full-bridge SMs across three main system configurations are presented. Full-bridge topologies offer high efficiency, some even higher than the state-of- the-art SiC two-level inverter. However, adapting them to BEVs requires significant architectural modifications to the BEV’s electrical system. The half-bridge topologies require fewer architectural modifications for adaption into the BEVs. However, they have lower efficiency and require a larger number of SMs, which increases the cost. The efficiency is increased with six-phase system configurations but at the cost of more SMs than three-phase system configurations. Another aspect of adaptability is the DC charging capabilities of BI-MMCs. The maximum DC charging power of the BI-MMCs with the same SM semiconductor losses as during traction is derived, and results show that most BI-MMCs have a maximum DC charging power of about 1MW.

    Key design parameters that affect the efficiency and cost of BI-MMCs are identified. They are the number of series-connected cells in an SM, SM DC-link capacitor energy, and MOSFET switching frequency. BI-MMCs with five to seven series-connected cells per SM have the highest efficiency, at an average power of 100 kW and considering phase-shifted carrier-based modulation. Selecting the MOSFET switching frequency close to the resonant frequency of the SM DC-link capacitors and the SM battery modules decreases the total efficiency. Increasing or decreasing the MOSFET switching frequency increases the efficiency but affects the loss distribution between the SM DC-link capacitors and the SM battery modules.

    BI-MMCs with nearest level modulation (NLM) have higher efficiencies than phase-shifted carrier-based modulation and the SiC two-level inverter. However, using NLM with low-frequency sort-and-select inter-SM balancing methods (sNLM) results in an uneven distribution of battery losses among the SMs, which may impact the thermal design. Using NLM with cyclic submodule duty cycle rotation at the fundamental frequency gives higher efficiencies than sNLM and an even distribution of battery losses among the SMs.

    Reconstruction of converter reference signals with a higher sample frequency at the submodule level can be used to adapt distributed control architecture to BI-MMCs. The advantage is the low communication burden between the central and the SM control units. Furthermore, the accuracy of the SM battery currents (over one fundamental period) is improved, and the output distortion is low.

    List of papers
    1. DC Charging Capabilities of Battery-Integrated Modular Multilevel Converters Based on Maximum Tractive Power
    Open this publication in new window or tab >>DC Charging Capabilities of Battery-Integrated Modular Multilevel Converters Based on Maximum Tractive Power
    2023 (English)In: Electricity, E-ISSN 2673-4826, Vol. 4, no 1, p. 62-77Article in journal (Refereed) Published
    Abstract [en]

    The increase in the average global temperature is a consequence of high greenhouse gas emissions. Therefore, using alternative energy carriers that can replace fossil fuels, especially for automotive applications, is of high importance. Introducing more electronics into an automotive battery pack provides more precise control and increases the available energy from the pack. Battery-integrated modular multilevel converters (BI-MMCs) have high efficiency, improved controllability, and better fault isolation capability. However, integrating the battery and inverter influences the maximum DC charging power. Therefore, the DC charging capabilities of 5 3-phase BI-MMCs for a 40-ton commercial vehicle designed for a maximum tractive power of 400 kW was investigated. Two continuous DC charging scenarios are considered for two cases: the first considers the total number of submodules during traction, and the second increases the total number of submodules to ensure a maximum DC charging voltage of 1250 V. The investigation shows that both DC charging scenarios have similar maximum power between 1 and 3 MW. Altering the number of submodules increases the maximum DC charging power at the cost of increased losses.

    Place, publisher, year, edition, pages
    MDPI, 2023
    Keywords
    EV powertrain; DC charging; batteries; DC-AC converters; MMC; BI-MMC; AC batteries; reconfigurable batteries; modular batteries
    National Category
    Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-191802 (URN)10.3390/electricity4010005 (DOI)001187454500001 ()
    Note

    Funding Agencies|Foundation for Strategic Environmental Research (MISTRA)

    Available from: 2023-02-15 Created: 2023-02-15 Last updated: 2025-03-20Bibliographically approved
    2. Design and Analysis of Battery-Integrated Modular Multilevel Converters for Automotive Powertrain Applications
    Open this publication in new window or tab >>Design and Analysis of Battery-Integrated Modular Multilevel Converters for Automotive Powertrain Applications
    2021 (English)In: 2021 23RD EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE21 ECCE EUROPE), IEEE , 2021Conference paper, Published paper (Refereed)
    Abstract [en]

    The automotive industry has grown considerably over the last century consequently increasing green-house gas emissions and thus contributing towards increase in the average global temperature. It is thus of paramount importance to increase the use of alternative energy sources. Electric vehicles have gained popularity over the last decade. However, a major concern with electric vehicles is their range. The range of an electric vehicle is limited by the battery pack, in particular, the weakest cell of the pack. One method of increasing the available energy from the battery pack is by introducing more electronics. Modular multilevel converters, with their modular concept, could be a viable solution. The concept of battery-integrated modular multilevel converters (BI-MMC) for automotive applications is explored. In particular, the impact of the number of cascaded cells per submodule is investigated, considering battery losses, DC-link capacitor losses, and the converter losses. Furthermore, an optimization of the DC-link capacitors and the selection of MOSFET switching frequency is presented in order to minimize the total losses.

    Place, publisher, year, edition, pages
    IEEE, 2021
    Series
    European Conference on Power Electronics and Applications, ISSN 2325-0313
    Keywords
    DC-AC converters, Modular Multilevel Converters, Power converters for EV, Electric vehicle, Hybrid Electric Vehicle (HEV)
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-187241 (URN)10.23919/EPE21ECCEEurope50061.2021.9570570 (DOI)000832143901075 ()9789075815375 (ISBN)9781665433846 (ISBN)
    Conference
    23rd European Conference on Power Electronics and Applications (EPE ECCE Europe), ELECTR NETWORK, sep 06-10, 2021
    Available from: 2022-08-15 Created: 2022-08-15 Last updated: 2025-03-20
    3. Experimental Evaluation of Battery Impedance and Submodule Loss Distribution for Battery Integrated Modular Multilevel Converters
    Open this publication in new window or tab >>Experimental Evaluation of Battery Impedance and Submodule Loss Distribution for Battery Integrated Modular Multilevel Converters
    2022 (English)In: 2022 24TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE22 ECCE EUROPE), Institute of Electrical and Electronics Engineers (IEEE), 2022Conference paper, Published paper (Refereed)
    Abstract [en]

    Greenhouse gas emissions and the increase in average global temperature are growing concerns now more so than ever. Therefore it is of importance to increase the use of alternative energy sources, especially in the automotive industry. Battery electric vehicles (BEV) have gained popularity over the past several years. However, the performance of a BEV is limited by the battery pack, in particular, the weakest cell in the pack. Therefore, improved cell controllability and high efficiency are seen as important directions for research and development and one direction where it can be achieved is through using battery-integrated modular multilevel converters (BI-MMC). The battery current in BI-MMCs contains additional harmonics and the frequency dependent losses of these harmonics are determined by the resonance between the battery and the DC-link capacitor bank. The paper presents an experimental validation of previously published theoretical results for both harmonic allocations and loss distribution at the switching frequency within the BI-MMC submodule. Furthermore, a methodology for measuring the battery impedance using the full-load converter switching currents is presented.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2022
    Series
    European Conference on Power Electronics and Applications, ISSN 2325-0313
    Keywords
    Modular Multilevel Converters (MMC); Power converters for EV; Batteries; DC-AC converters; Automotive application
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-187242 (URN)000886231600101 ()9789075815399 (ISBN)9781665487009 (ISBN)
    Conference
    24th European Conference on Power Electronics and Applications (EPE ECCE Europe), Hanover, GERMANY, sep 05-09, 2022
    Available from: 2022-08-15 Created: 2022-08-15 Last updated: 2025-03-20Bibliographically approved
    4. Experimental Evaluation of Submodule Losses in Battery-Integrated MMCs with NLM and PSPWM
    Open this publication in new window or tab >>Experimental Evaluation of Submodule Losses in Battery-Integrated MMCs with NLM and PSPWM
    2024 (English)In: 2024 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC, IEEE , 2024Conference paper, Published paper (Refereed)
    Abstract [en]

    Electric vehicle (EV) battery packs contain several parallel and series-connected cells and variations in leakage currents and cell characteristics result in heterogeneous discharge rates among cells, thus limiting the total energy delivery of the pack. Battery-integrated modular multilevel converters (BI-MMCs) increase the controllability of cells thereby improving the energy utilization of the battery pack. Design optimization for BI-MMC with phase-shifted modulation (PSPWM) showed that submodule (SM) DC-link capacitors designed to bypass the switching frequency components result in minimum total losses. However, this requires a large DC-link capacitor bank, which increases the system cost. An alternative modulation technique, nearest level modulation (NLM), characterized by low semiconductor switching frequency, is often preferred for MMCs with many SMs. The first contribution is an experimental loss comparison in an SM of a BI-MMC with PSPWM and NLM. The second contribution is investigating the impact of the size of DC-link capacitors on battery and capacitor losses for NLM. The experiments showed that the battery and capacitor losses are independent of the DC-link capacitor size when using NLM. Furthermore, NLM has lower total losses but higher battery losses than PSPWM. A single-phase 4-SM BI-MMC is used as the experimental platform for the comparison.

    Place, publisher, year, edition, pages
    IEEE, 2024
    Series
    Annual IEEE Applied Power Electronics Conference and Exposition (APEC), ISSN 1048-2334, E-ISSN 2470-6647
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-203321 (URN)10.1109/APEC48139.2024.10509105 (DOI)001227525000122 ()9798350316643 (ISBN)9798350316650 (ISBN)
    Conference
    2024 IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, FEB 25-29, 2024
    Available from: 2024-05-07 Created: 2024-05-07 Last updated: 2025-03-20
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  • Public defence: 2025-04-25 10:15 Online through Zoom (contact ninna.stensgard@liu.se) and Ada Lovelace, LinköpingOrder onlineBuy this publication >>
    Shoja, Shamisa
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Complexity Certification Algorithms for Mixed-Integer Linear and Quadratic Programming: with Applications to Hybrid MPC2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Model predictive control (MPC) generates control actions by iteratively solving optimization problems while explicitly accounting for system dynamics and constraints. Hybrid MPC extends this framework to systems involving both continuous and discrete variables, where the underlying optimization problems typically take the form of mixed-integer linear programs (MILPs) or mixed-integer quadratic programs (MIQPs), depending on the chosen performance measures. Ensuring the reliable real-time execution of hybrid MPC, particularly in safety-critical applications, requires rigorous worst-case computational complexity guarantees to meet limited time and hardware constraints.

    Motivated by this need, this thesis develops a comprehensive framework for certifying the worst-case computational complexity of solving MILPs and MIQPs, tailored to hybrid MPC applications. Specifically, it focuses on the branch-and-bound (B&B) method, a standard approach for solving these non-convex optimization problems through solving a sequence of relaxations. The proposed framework quantifies key complexity measures, such as the total number of linear systems of equations solved in relaxations (iterations) and the number of relaxations (B&B nodes) explored within B&B, to provide a priori guarantees on computational effort, thereby enabling a deep understanding of the computational resources needed to solve these optimization problems in real time.

    To enhance practical applicability, the framework is extended to incorporate algorithmic strategies commonly used in B&B, such as various branching strategies, node-selection strategies, and warm-starting of the solver of the relaxations in B&B. Additionally, it is adapted to suboptimal B&B algorithms, which reduce computational effort by trading off global optimality. The framework is further extended to certify certain primal heuristics, including start and improvement heuristics, which leverage feasible solutions to enhance efficiency throughout the B&B process. To further improve scalability, this thesis introduces parallel complexity-certification algorithms, enabling the analysis of high-dimensional and computationally demanding problems. By providing theoretical guarantees and detailed insights, these results facilitate the reliable deployment of B&B-based MILP and MIQP solvers, which are essential for real-time applications such as hybrid MPC, where computational tractability needs to be ensured a priori.

    List of papers
    1. Overall Complexity Certification of a Standard Branch and Bound Method for Mixed-Integer Quadratic Programming
    Open this publication in new window or tab >>Overall Complexity Certification of a Standard Branch and Bound Method for Mixed-Integer Quadratic Programming
    2022 (English)In: 2022 AMERICAN CONTROL CONFERENCE (ACC), Atlanta, GA, USA: IEEE, 2022, p. 4957-4964Conference paper, Published paper (Refereed)
    Abstract [en]

    This paper presents a method to certify the computational complexity of a standard Branch and Bound method for solving Mixed-Integer Quadratic Programming (MIQP) problems defined as instances of a multi-parametric MIQP. Beyond previous work, not only the size of the binary search tree is considered, but also the exact complexity of solving the relaxations in the nodes by using recent results from exact complexity certification of active-set QP methods. With the algorithm proposed in this paper, a total worst-case number of QP iterations to be performed in order to solve the MIQP problem can be determined as a function of the parameter in the problem. An important application of the proposed method is Model Predictive Control for hybrid systems, that can be formulated as an MIQP that has to be solved in real-time. The usefulness of the proposed method is successfully illustrated in numerical examples.

    Place, publisher, year, edition, pages
    Atlanta, GA, USA: IEEE, 2022
    Keywords
    Mixed-integer quadratic Programming, Complexity Certification
    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:liu:diva-188903 (URN)10.23919/ACC53348.2022.9867176 (DOI)000865458704088 ()2-s2.0-85138492032 (Scopus ID)9781665451963 (ISBN)9781665494809 (ISBN)
    Conference
    American Control Conference (ACC), Atlanta, GA, USA, 08-10 June, 2022
    Funder
    Wallenberg AI, Autonomous Systems and Software Program (WASP)
    Note

    Funding: Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation

    Available from: 2022-09-30 Created: 2022-09-30 Last updated: 2025-03-25Bibliographically approved
    2. Exact Complexity Certification of a Standard Branch and Bound Method for Mixed-Integer Linear Programming
    Open this publication in new window or tab >>Exact Complexity Certification of a Standard Branch and Bound Method for Mixed-Integer Linear Programming
    2022 (English)In: Proceedings of 2022 Conference on Decision and Control (CDC), Institute of Electrical and Electronics Engineers (IEEE), 2022, p. 6298-6305Conference paper, Published paper (Refereed)
    Abstract [en]

    Model predictive control (MPC) with linear cost function for hybrid systems requires the solution of a mixed-integer linear program (MILP) at each sampling time. The branch and bound (B&B) method is a commonly used tool for solving mixed-integer problems. In this work, we present an algorithm to exactly certify the computational complexity of a standard B&B-based MILP solver. By the proposed method, guarantees on worst-case complexity bounds, e.g., the worst-case iterations or size of the B&B tree, are provided. This knowledge is a fundamental requirement for the implementation of MPC in a real-time system. Different node selection strategies, including best-first, are considered when certifying the complexity of the B&B method. Furthermore, the proposed certification algorithm is extended to consider warm-starting of the inner solver in the B&B. We illustrate the usefulness of the proposed algorithm by comparing against the corresponding online MILP solver in numerical experiments using both cold-started and warm-started LP solvers.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2022
    Series
    IEEE Conference on Decision and Control, ISSN 0743-1546, E-ISSN 2576-2370
    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:liu:diva-192390 (URN)10.1109/CDC51059.2022.9992451 (DOI)000948128105047 ()2-s2.0-85147012584 (Scopus ID)9781665467629 (ISBN)9781665467612 (ISBN)
    Conference
    The 61st IEEE Conference on Decision and Control (CDC), Cancun, Mexico, 06-09 December, 2022
    Note

    Funding: Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation

    Available from: 2023-03-14 Created: 2023-03-14 Last updated: 2025-03-25Bibliographically approved
    3. Exact Complexity Certification of Suboptimal Branch-and-Bound Algorithms for Mixed-Integer Linear Programming
    Open this publication in new window or tab >>Exact Complexity Certification of Suboptimal Branch-and-Bound Algorithms for Mixed-Integer Linear Programming
    2023 (English)In: IFAC PAPERSONLINE, ELSEVIER , 2023, Vol. 56, no 2, p. 7428-7435Conference paper, Published paper (Refereed)
    Abstract [en]

    In this paper, we present a method to exactly certify the computational complexity of standard suboptimal branch-and-bound (B&B) algorithms for computing suboptimal solutions to mixed-integer linear programming (MILP) problems. Three well-known approaches for suboptimal B&B are considered. This work shows that it is possible to exactly certify the computational complexity also when these approaches are used. Moreover, it also enables to compute exact bounds on the level of suboptimality actually to be obtained online, also for methods previously without any such guarantees. It additionally provides a novel deeper insight into how they affect the performance of the B&B algorithm in terms of the required computation time and memory storage. The exact bounds on the online worst-case computational complexity (e.g., the accumulated number of LP solver iterations or size of the B&B tree) and the worst-case suboptimality computed with the proposed method are very relevant for real-time applications such as Model Predictive Control (MPC) for hybrid systems. The numerical experiments confirm the correctness of the proposed method, and they demonstrate the usefulness of the certification method for certification of a standard online B&B-based MILP solver employing the three considered suboptimal techniques. Copyright (c) 2023 The Authors.

    Place, publisher, year, edition, pages
    ELSEVIER, 2023
    Keywords
    Numerical methods for optimal control; Optimal control of hybrid systems; Mixed-integer linear programming; Branch and bound method; Complexity certification; Suboptimal solutions
    National Category
    Discrete Mathematics
    Identifiers
    urn:nbn:se:liu:diva-202555 (URN)10.1016/j.ifacol.2023.10.624 (DOI)001122557300187 ()
    Conference
    22nd World Congress of the International Federation of Automatic Control (IFAC), Yokohama, JAPAN, jul 09-14, 2023
    Note

    Funding Agencies|Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation

    Available from: 2024-04-16 Created: 2024-04-16 Last updated: 2025-03-25
    4. Exact Complexity Certification of Start Heuristics in Branch-and-Bound Methods for Mixed-Integer Linear Programming
    Open this publication in new window or tab >>Exact Complexity Certification of Start Heuristics in Branch-and-Bound Methods for Mixed-Integer Linear Programming
    2023 (English)In: 2023 62ND IEEE CONFERENCE ON DECISION AND CONTROL, CDC, IEEE , 2023, p. 2292-2299Conference paper, Published paper (Refereed)
    Abstract [en]

    Model predictive control (MPC) with linear performance measure for hybrid systems requires the solution of a mixed-integer linear program (MILP) at each time instance. A well-known method to solve MILP problems is branch-and-bound (B&B). To enhance the performance of B&B, start heuristic methods are often used, where they have shown to be useful supplementary tools to find good feasible solutions early in the B&B search tree, hence, reducing the overall effort in B&B to find optimal solutions. In this work, we extend the recently-presented complexity certification framework for B&B-based MILP solvers to also certify computational complexity of the start heuristics that are integrated into B&B. Therefore, the exact worst-case computational complexity of the three considered start heuristics and, consequently, the B&B method when applying each one can be determined offline, which is of significant importance for real-time applications of hybrid MPC. The proposed algorithms are validated by comparing against the corresponding online heuristic-based MILP solvers in numerical experiments.

    Place, publisher, year, edition, pages
    IEEE, 2023
    Series
    IEEE Conference on Decision and Control, ISSN 0743-1546, E-ISSN 2576-2370
    National Category
    Control Engineering
    Identifiers
    urn:nbn:se:liu:diva-201875 (URN)10.1109/CDC49753.2023.10384105 (DOI)001166433801147 ()9798350301243 (ISBN)9798350301250 (ISBN)
    Conference
    62nd IEEE Conference on Decision and Control (CDC), IEEE Control Syst Soc, Singapore, SINGAPORE, dec 13-15, 2023
    Note

    Funding Agencies|Wallenberg AI, Autonomous Systems and Software Program (WASP) - Knut and Alice Wallenberg Foundation

    Available from: 2024-03-28 Created: 2024-03-28 Last updated: 2025-03-25
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  • Public defence: 2025-04-25 13:00 K1, Kåkenhus, NorrköpingOrder onlineBuy this publication >>
    Holstein, Jane
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Prevention, Rehabilitation and Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Learning Cultural Competence in Healthcare: Self-assessment and Education2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background

    Healthcare in Sweden must provide equitable and effective care to all residents by adapting to an aging and multicultural population with varied needs. To achieve this, increased cultural competence among healthcare professionals is required. To support healthcare professionals, in developing professional knowledge in encounters with migrant persons a self-rating instrument measuring cultural competence as well as education in cultural competence can equip professionals to meet this need. Improving cultural competence in healthcare can enhance communication and patient satisfaction, reduce misunderstandings and errors, and improve overall healthcare outcomes. However, there is a lack of relevant instruments and education to learn cultural competence across various healthcare areas in Sweden.

    Aim

    The general aim of this thesis was to develop and evaluate a self-assessment instrument in cultural competence for healthcare professionals. Further the aim was to design an educational program to enhance cultural competence among healthcare professionals working in interprofessional teams.

    Methods

    This thesis consists of four studies, with varied methodology and design. In study I, 19 occupational therapists participated, divided into four focus groups. Qualitative content analysis was used to examine the content validity and utility of the CCAI-S. In study II data was collected by a web-based questionnaire based on CCAI-S to 428 occupational therapists to investigate the construct validity, reliability and utility of the CCAI-S. Factor analysis was performed as well as descriptive statistics. In study III data was collected by a web-based questionnaire based on CCAI-S to measure cultural competence in 279 healthcare professionals in interprofessional teams. Data was analyzed with descriptive statistics, univariate analyses and linear regression. Study IV used a co-design methodology, in which healthcare professionals (n =11), patients (n =6) and researchers (n =5) collaborated to develop an educational programme in cultural competence. The analysis in the process was integrated with data collection through an iterative and agile approach.

    Results

    The CCAI-S showed high content validity for all 24 items, though six required reformulation. It demonstrated strong utility for increasing cultural awareness among healthcare professionals and highlighted the importance of organizational support in developing cultural competence. A three-factor model was identified: 'Openness and awareness,' 'Workplace support,' and 'Interaction skills,' with high factor loadings and strong Cronbach’s Alpha support. Even though all 24 items were deemed clinically relevant based on construct validity of CCAI-S led to 13 of 24 items deemed relevant. 58% of healthcare professionals reported high levels of Openness and awareness, 35% high interaction skills, and 6% high workplace support. Cultural competence was linked to a high percentage of migrant clients and prior cultural competence development through experience or education. Professionals felt open and aware but lacked workplace support and education. A prototype of an educational programme with four modules was co-designed: cultural knowledge, reasoning, interaction, and context, each with specific learning objectives and activities to enhance cultural competence in healthcare.

    Conclusion

    The CCAI-S demonstrated good measurement properties and high clinical relevance. Most healthcare professionals felt culturally open and aware but needed more workplace support and education to improve their interaction skills and develop cultural competence. The CCAI-S can guide organizations in enhancing staff cultural competence. The educational program's clinical relevance was ensured through co-design by professionals and patients. Fostering cultural competence in healthcare is essential for meeting diverse patient needs. Prioritizing self-assessment and education can lead to a more inclusive and effective healthcare system.

    List of papers
    1. Validity and utility of the Swedish version of the Cultural Competence Assessment Instrument
    Open this publication in new window or tab >>Validity and utility of the Swedish version of the Cultural Competence Assessment Instrument
    2019 (English)In: British Journal of Occupational Therapy, ISSN 0308-0226, E-ISSN 1477-6006, Vol. 82, no 7, p. 422-432Article in journal (Refereed) Published
    Abstract [en]

    Introduction: Global migration as well as migration to Sweden has increased during the last few decades. A self-rating instrument that measures cultural competence could support occupational therapists' professional knowledge when they encounterclients from different cultural backgrounds. The purpose of this study was to evaluate the content validity and utility of the Swedish version of the Cultural Competence Assessment Instrument among occupational therapists. Nineteen occupational therapists participated in four focus groups.

    Method: Qualitative analysis was used to evaluate content validity and utility.

    Results: The results revealed that all 24 items of the Cultural Competence Assessment Instrument were valid, even though six of the items were in need of reformulations and exemplifications. The category Interactions with clients showed that the Cultural Competence Assessment Instrument – Swedish version could be utilised individually to raise awareness on cultural issues inpractice. The category Workplace and its organisational support showed that the Cultural Competence Assessment Instrument – Swedish version had potential for use in different workplaces, and indicated the importance of organisational support in the development of communications and cultural competence.

    Conclusion: The evaluation indicated positive content validity for the Cultural Competence Assessment Instrument – Swedish version, and that it had the potential to be utilised in the Swedish context.

    Keywords
    Instrument development, occupational therapy, qualitative research, ethnicity, cultural competence
    National Category
    Occupational Therapy
    Identifiers
    urn:nbn:se:liu:diva-156137 (URN)10.1177/0308022619825813 (DOI)000473502900005 ()
    Available from: 2019-04-05 Created: 2019-04-05 Last updated: 2025-03-24
    2. Clinical Relevance and Psychometric Properties of the Swedish Version of the Cultural Competence Assessment Instrument
    Open this publication in new window or tab >>Clinical Relevance and Psychometric Properties of the Swedish Version of the Cultural Competence Assessment Instrument
    2020 (English)In: Occupational Therapy International, ISSN 0966-7903, E-ISSN 1557-0703, Vol. 2020, article id 2453239Article in journal (Refereed) Published
    Abstract [en]

    Based on the increasing diversity of Swedish society, health professionals, like occupational therapists, find it challenging to provide culturally competent services to international clients. Consequently, cultural competence among professionals needs to be measured and improved using psychometrically tested instruments. This study examines the clinical relevance, construct validity, and reliability of the Swedish version of the Cultural Competence Assessment Instrument among Swedish occupational therapists. Material and Methods. A randomised sample of 312 Swedish occupational therapists answered a survey based on the Swedish version of the Cultural Competence Assessment Instrument with supplementary questions on the clinical relevance of the instrument. Descriptive statistics were used to examine the clinical relevance of the Swedish version of the Cultural Competence Assessment Instrument. Factor analyses, both exploratory and confirmatory, were run to examine the factor structure. Cronbachs alpha was performed to assess the internal consistency of the instrument. Results. The participants reported that the 24 items had high clinical relevance. The validation yielded a three-factor model: openness and awareness, workplace support, and interaction skills. All three of these factors showed high loadings. Conclusions. The study results indicated positive clinical relevance and psychometric properties for the Swedish version of the Cultural Competence Assessment Instrument and strong support to be utilised in Sweden. The implications of this study are important given the rapid growth in migration over the last few decades. A self-rating instrument measuring cultural competence could support occupational therapists professional knowledge and development when they interact with international clients. As the tool was originally developed in English in the United States, the feedback from the Swedish version could potentially be useful for the instrument in modified form and for use by occupational therapists in English-speaking countries.

    Place, publisher, year, edition, pages
    WILEY-HINDAWI, 2020
    National Category
    Occupational Therapy
    Identifiers
    urn:nbn:se:liu:diva-165955 (URN)10.1155/2020/2453239 (DOI)000531664400001 ()32395094 (PubMedID)
    Available from: 2020-06-04 Created: 2020-06-04 Last updated: 2025-03-24
    3. Cultural competence in healthcare professionals, specialised in diabetes, working in primary healthcare-A descriptive study
    Open this publication in new window or tab >>Cultural competence in healthcare professionals, specialised in diabetes, working in primary healthcare-A descriptive study
    Show others...
    2022 (English)In: Health & Social Care in the Community, ISSN 0966-0410, E-ISSN 1365-2524, Vol. 30, no 3, p. e717-e726Article in journal (Refereed) Published
    Abstract [en]

    Self-care is the most important cornerstone of diabetes treatment. As self-care is affected by cultural beliefs, it is important for healthcare professionals to be able to adapt their educational approach and to be culturally competent. The aim of this study was to describe the cultural competence in Swedish healthcare professionals, specialised in diabetes care and to examine related factors for cultural competence. The healthcare professionals perceived level of cultural competence was measured across three domains-Openness and awareness, Workplace support and Interaction skills-in 279 Swedish healthcare professionals from all 21 regions of Sweden, using the Cultural Competence Assessment Instrument (Swedish version-CCAI-S). Descriptive statistics were used to describe cultural competence in healthcare professionals, and linear regression was conducted to examine factors related to cultural competence. Of the healthcare professionals studied, 58% perceived that they had a high level of Openness and awareness, 35% perceived that they had a high level of Interaction skills and 6% perceived that they had a high level of Workplace support. Two factors were found to be related to cultural competence, namely, high percentage of migrant clients at the healthcare clinic and whether the healthcare professionals previously had developed cultural competence through practical experience, education and/or by themselves. In conclusion, most healthcare professionals perceived that they had cultural openness and awareness but need more support from their workplace to improve their interaction skills. Cultural competence-related education could support the healthcare professionals to develop interaction skills.

    Place, publisher, year, edition, pages
    WILEY, 2022
    Keywords
    cultural background; cultural competence; diabetes mellitus; healthcare professionals; primary healthcare; self-care
    National Category
    Nursing
    Identifiers
    urn:nbn:se:liu:diva-177424 (URN)10.1111/hsc.13442 (DOI)000663264800001 ()34145649 (PubMedID)
    Available from: 2021-06-29 Created: 2021-06-29 Last updated: 2025-03-24
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  • Public defence: 2025-04-25 13:00 I:101, LinköpingOrder onlineBuy this publication >>
    Forsell, Johan
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Lärares och elevers erfarenheter av grupparbetsbedömning i gymnasieskolan: Möjligheter, utmaningar samt konsekvenser för validitet, reliabilitet och rättvisa2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis aims to explore upper secondary school teachers’ and students’ experiences of opportunities and challenges in group work assessment and the consequences that group work assessment entails on the quality of assessment in terms of validity, reliability and fairness. In the thesis, there is a particular interest in how teachers can collect evidence for summative assessment of students’ individual knowledge developed through group work. This thesis is based on a qualitative research approach. The empirical data in the first sub-study, a systematic literature review, consists of 83 peer-reviewed publications. The second sub-study is based on empirical data from semi-structured interviews. A total of 12 interviews with teachers were conducted, before and after fulfilling a group work assignment. The third sub-study is based on empirical data from 33 focus group interviews with 129 upper secondary school students. The fourth sub-study is based on empirical data from 23 video observations of cross-group presentations where 128 students carried out individual presentations of a previous group work on linguistic variations. In addition to the video observations, six of the interviews from the second sub-study were also used. Thematic analysis was used as an analytical method in all four empirical sub-studies. The results of the thesis show how group work assessment differs from assessment in a general sense in that, for example, group work assessment can be carried out on several levels. Based on upper secondary school teachers’ and upper secondary school students’ experiences of group work assessment, the thesis shows several opportunities and challenges. Teachers find it challenging to discern and assess students’ individual knowledge in group work. Group work assessment at group level has consequences on the validity and reliability of the assessment and is linked by both teachers and students to unfairness. Students experience unfairness in group work assessment as everyone contributes differently but receives the same assessment. The thesis shows an opportunity to use individual cross-group presentations to collect evidence to assess students’ individual knowledge. At the same time, teachers experience challenges with the method, such as giving time for presentations and assessing script-bound students. A conclusion is that the challenges can be prevented by teachers being active when collecting evidence from cross-group presentations by asking questions and interacting with the students. In this way, teachers can collect broader evidence that speaks for a more valid, reliable and fair individual group work assessment of students’ knowledge.

    List of papers
    1. Group Work Assessment: Assessing Social Skills at Group Level
    Open this publication in new window or tab >>Group Work Assessment: Assessing Social Skills at Group Level
    2020 (English)In: Small Group Research, ISSN 1046-4964, E-ISSN 1552-8278, Vol. 51, no 1, p. 87-124Article in journal (Refereed) Published
    Abstract [en]

    Group work assessment is often described by teachers as complex and challenging, with individual assessment and fair assessment emerging as dilemmas. The aim of this literature review is to explore and systematize research about group work assessment in educational settings. This is an integrated research area consisting of research combining group work and classroom assessment. A database search was conducted, inspired by the guidelines of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The analysis and categorization evolved into a typology consisting of five themes: (a) purpose of group work assessment, (b) what is assessed in group work, (c) methods for group work assessment, (d) effects and consequences of group work assessment, and (e) quality in group work assessment. The findings reveal that research in the field of group work assessment notably focuses on social skills and group processes. Peer assessment plays a prominent role and teachers as assessors are surprising absences in the reviewed research.

    Place, publisher, year, edition, pages
    Sage Publications, 2020
    Keywords
    group work, assessment, systematic review, group work assessment, education
    National Category
    Pedagogy Sociology (Excluding Social Work, Social Anthropology, Demography and Criminology)
    Identifiers
    urn:nbn:se:liu:diva-161030 (URN)10.1177/1046496419878269 (DOI)000492259900001 ()
    Funder
    Swedish Research Council
    Note

    Funding agencies: Swedish Research CouncilSwedish Research Council [VR 721 2012-5476]

    Available from: 2019-10-17 Created: 2019-10-17 Last updated: 2025-03-25Bibliographically approved
    2. Teachers’ perceived challenges in group work assessment
    Open this publication in new window or tab >>Teachers’ perceived challenges in group work assessment
    2021 (English)In: Cogent Education, E-ISSN 2331-186X, Vol. 8, no 1, article id 1886474Article in journal (Refereed) Published
    Abstract [en]

    Group work assessment is a challenging and complex practice for teachers. This study focuses on the challenges teachers perceive before and after participating in a group work assessment project that emphasizes individual assessment. By conducting a qualitative thematic analysis of twelve interviews with six teachers at upper secondary schools in Sweden, several challenges could be identified. The most prominent challenge concerning group work assessment is how to discern students’ individual performance within groups. This challenge has consequences for both the validity and the fairness of the assessment. Further, teachers experienced challenges with (un)fairness in group work assessment, in terms of both achieving fairness and having to deal with students’ emotions regarding perceived unfairness. The results also show how teachers perceive inadequate conditions, such as a lack of time and methods, and generate challenges in their practice, which is also related to reliability.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2021
    Keywords
    Group work assessment; challenges; intergroup presentations; quality in assessment
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-173332 (URN)10.1080/2331186X.2021.1886474 (DOI)000618272300001 ()
    Funder
    Swedish Research Council, VR 721 2012-5476
    Note

    Funding agencies: Swedish Research CouncilSwedish Research CouncilEuropean Commission [VR 721 2012-5476]

    Available from: 2021-02-16 Created: 2021-02-16 Last updated: 2025-03-25
    3. Upper secondary school students’ perspectives on un/fairness in group work assessment
    Open this publication in new window or tab >>Upper secondary school students’ perspectives on un/fairness in group work assessment
    2025 (English)In: Research Papers in Education, ISSN 0267-1522, E-ISSN 1470-1146, Vol. 40, no 2, p. 259-280Article in journal (Refereed) Published
    Abstract [en]

    Students' perspectives of un/fairness in group work assessment are known to be related to the issues of varied contributions in group work and how to discern each student's contribution or knowledge from the group's joint work. Students' perceptions of un/fairness in group work assessment are important since it relates to their motivation. This study aims to investigate upper secondary students' perspectives on un/fairness in group work assessment. In the study, 129 upper secondary school students in Sweden between the ages of 15 and 16 years participated. The students were interviewed in 33 focus groups. The interviews were thematically analysed. The study's findings illustrate how ambition, motivation and friendship relations in groups may vary and cause what students perceive as unfairness. Varied ambitions and motivations among group members also appear to breed situations where group members' contributions to group work may vary, which also is perceived by students as unfair. Other factors that can contribute to a perception of unfairness are when knowledge levels vary among group members or friendship relations. How un/fairness is perceived also depends on the level at which the assessment is implemented, group or individual level. The greatest experience of unfairness is generated by implementing group assessment.

    Place, publisher, year, edition, pages
    ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2025
    Keywords
    Group work assessment; fairness; unfairness; upper secondary school; students' perspectives
    National Category
    Pedagogy Didactics
    Identifiers
    urn:nbn:se:liu:diva-206097 (URN)10.1080/02671522.2024.2378429 (DOI)001271099700001 ()
    Funder
    Swedish Research Council, VR 721 2012-5476Swedish Research Council
    Note

    Funding Agencies|Swedish Research Council [VR 721 2012-5476]

    Available from: 2024-08-05 Created: 2024-08-05 Last updated: 2025-04-10
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  • Public defence: 2025-04-25 13:15 Dome, Visualiseringscenter C, NorrköpingOrder onlineBuy this publication >>
    Elmquist, Elias
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, Faculty of Science & Engineering.
    Sensibly Sound: Human-Centered Integration of Sonification and Visualization2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With an increased creation of and access to data, and a growing demand on humans in analytical and decision-making processes, there is a need to further facilitate perceptual and cognitive abilities to support these processes. An approach to support these tasks is to leverage more sensory systems, such as the auditory, to increase information retention to get a more comprehensive understanding of a dataset or situation, while also involving more senses to further engage the user. Audiovisual data interfaces enable the distribution of data variables to any of the two senses to reduce the risk of cognitive overload, or highlight specific data variables by mapping them to both sensory modalities. However, the success of an audiovisual data interface is dependent on the integration of the two senses and how this is utilized in the resulting interface.

    This thesis contributes to sonification research by taking a human-centered approach to integrating sonification and visualization. The human-centered approach involved working with domain experts and users during the design process of the sonification, and to create perceptually motivated designs by utilizing how the auditory and visual systems complement each other and how they are integrated in cognition for sense-making.

    The thesis contains six studies that explored the integration of sonification and visualization, ranging from literature surveys to design-oriented studies. A state-of-the-art report provided a survey on the integration of sonification and visualization to offer an introduction to the field to new and current practitioners. In another study, a conceptual framework for scene analysis was developed to support the design and analysis of audiovisual data representations. The rest of the studies were design-oriented, where each focused on a specific aspect of how sonification can complement visualization, depending on the domain and tasks of the study. Other than providing concrete examples of audiovisual integrations, the main contributions of the design-oriented studies are provided in their evaluation results in the form of design recommendations. These include the use of redundant mappings for multi-dimensional data analysis, and considering subjective differences of domain experts for situational awareness support in air traffic control. The design-oriented studies also compared sonification designs, where one study showed a potential trade-off of using informative or pleasant designs for astronomy science communication. Another comparison showed that concrete sonification designs can complement abstract visualizations. Lastly, the thesis provides design considerations by comparing the level of redundancy, indexicality, and complexity of each sonification design through the developed conceptual framework. Overall, this thesis offers motivated recommendations for the integration of sonification and visualization.

    List of papers
    1. Open Your Ears and Take a Look: A State‐of‐the‐Art Report on the Integration of Sonification and Visualization
    Open this publication in new window or tab >>Open Your Ears and Take a Look: A State‐of‐the‐Art Report on the Integration of Sonification and Visualization
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    2024 (English)In: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, Vol. 43, no 3, article id e15114Article in journal (Refereed) Published
    Abstract [en]

    The research communities studying visualization and sonification for data display and analysis share exceptionally similar goals, essentially making data of any kind interpretable to humans. One community does so by using visual representations of data, and the other community employs auditory (non-speech) representations of data. While the two communities have a lot in common, they developed mostly in parallel over the course of the last few decades. With this STAR, we discuss a collection of work that bridges the borders of the two communities, hence a collection of work that aims to integrate the two techniques into one form of audiovisual display, which we argue to be “more than the sum of the two.” We introduce and motivate a classification system applicable to such audiovisual displays and categorize a corpus of 57 academic publications that appeared between 2011 and 2023 in categories such as reading level, dataset type, or evaluation system, to mention a few. The corpus also enables a meta-analysis of the field, including regularly occurring design patterns such as type of visualization and sonification techniques, or the use of visual and auditory channels, showing an overall diverse field with different designs. An analysis of a co-author network of the field shows individual teams without many interconnections. The body of work covered in this STAR also relates to three adjacent topics: audiovisual monitoring, accessibility, and audiovisual data art. These three topics are discussed individually in addition to the systematically conducted part of this research. The findings of this report may be used by researchers from both fields to understand the potentials and challenges of such integrated designs while hopefully inspiring them to collaborate with experts from the respective other field.

    Place, publisher, year, edition, pages
    Wiley-Blackwell Publishing Inc., 2024
    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-204437 (URN)10.1111/cgf.15114 (DOI)001241901600001 ()
    Conference
    EuroVis 2024
    Funder
    Knut and Alice Wallenberg Foundation, KAW 2019.0024
    Note

    Funding Agencies|Knut and Alice Wallenberg Foundation

    Available from: 2024-06-11 Created: 2024-06-11 Last updated: 2025-03-21
    2. Towards a Systematic Scene Analysis Framework for Audiovisual Data Representations
    Open this publication in new window or tab >>Towards a Systematic Scene Analysis Framework for Audiovisual Data Representations
    2024 (English)In: Audiovisual Symposium notes, Falun, 2024Conference paper, Oral presentation with published abstract (Refereed)
    Place, publisher, year, edition, pages
    Falun: , 2024
    Keywords
    Audiovisual integration, Visualization, Sonification, Scene graph, Scene analysis
    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-210422 (URN)
    Conference
    Audiovisual Symposium
    Funder
    Knut and Alice Wallenberg Foundation, 2019.0024
    Available from: 2024-12-13 Created: 2024-12-13 Last updated: 2025-03-21
    3. Parallel Chords: an audio-visual analytics design for parallel coordinates
    Open this publication in new window or tab >>Parallel Chords: an audio-visual analytics design for parallel coordinates
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    2024 (English)In: Personal and Ubiquitous Computing, ISSN 1617-4909, E-ISSN 1617-4917Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    One of the commonly used visualization techniques for multivariate data is the parallel coordinates plot. It provides users with a visual overview of multivariate data and the possibility to interactively explore it. While pattern recognition is a strength of the human visual system, it is also a strength of the auditory system. Inspired by the integration of the visual and auditory perception in everyday life, we introduce an audio-visual analytics design named Parallel Chords combining both visual and auditory displays. Parallel Chords lets users explore multivariate data using both visualization and sonification through the interaction with the axes of a parallel coordinates plot. To illustrate the potential of the design, we present (1) prototypical data patterns where the sonification helps with the identification of correlations, clusters, and outliers, (2) a usage scenario showing the sonification of data from non-adjacent axes, and (3) a controlled experiment on the sensitivity thresholds of participants when distinguishing the strength of correlations. During this controlled experiment, 35 participants used three different display types, the visualization, the sonification, and the combination of these, to identify the strongest out of three correlations. The results show that all three display types enabled the participants to identify the strongest correlation — with visualization resulting in the best sensitivity. The sonification resulted in sensitivities that were independent from the type of displayed correlation, and the combination resulted in increased enjoyability during usage.

    Place, publisher, year, edition, pages
    Springer, 2024
    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-203454 (URN)10.1007/s00779-024-01795-8 (DOI)2-s2.0-85191992877 (Scopus ID)
    Funder
    Knut and Alice Wallenberg Foundation, 2019.0024
    Available from: 2024-05-13 Created: 2024-05-13 Last updated: 2025-03-21
    4. SonAir: the design of a sonification of radar data for air traffic control
    Open this publication in new window or tab >>SonAir: the design of a sonification of radar data for air traffic control
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    2023 (English)In: Journal on Multimodal User Interfaces, ISSN 1783-7677, E-ISSN 1783-8738, Vol. 17, no 3, p. 137-149Article in journal (Refereed) Published
    Abstract [en]

    Along with the increase of digitalization and automation, a new kind of working environment is emerging in the field of air traffic control. Instead of situating the control tower at the airport, it is now possible to remotely control the airport at any given location, i.e. in a remote tower center (RTC). However, by controlling the airport remotely, the situational awareness and sense of presence might be compromised. By using directional sound, a higher situational awareness could potentially be achieved while also offloading the visual perception which is heavily used in air traffic control. Suitable use cases for sonification in air traffic control were found through workshops with air traffic controllers. A sonification design named SonAir was developed based on the outcome of the workshops, and was integrated with an RTC simulator for evaluating to what degree SonAir could support air traffic controllers in their work. The results suggest that certain aspects of SonAir could be useful for air traffic controllers. A continuous sonification where the spatial positioning of aircraft were conveyed was experienced to be partially useful, but the intrusiveness of SonAir should be further considered to fit the air traffic controllers’ needs. An earcon that conveyed when an aircraft enters the airspace and from which direction was considered useful to support situational awareness.

    Place, publisher, year, edition, pages
    SPRINGER, 2023
    Keywords
    Sonification; Air traffic control; Situational awareness; User evaluation
    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-196256 (URN)10.1007/s12193-023-00404-x (DOI)001021523300001 ()
    Note

    Funding: Swedish Transport Authority [TRV-2019/53555]; Knut and Alice Wallenberg Foundation [KAW 2019.0024]

    Available from: 2023-07-08 Created: 2023-07-08 Last updated: 2025-03-21
    5. OpenSpace Sonification: Complementing Visualization of the Solar System with Sound
    Open this publication in new window or tab >>OpenSpace Sonification: Complementing Visualization of the Solar System with Sound
    2021 (English)In: Proceedings of the 26th International Conference on Auditory Display (ICAD 2021) / [ed] Areti Andreopoulou, Milena Droumeva, Joseph W. Newbold, Kyla McMullen and Paul Vickers, The International Community for Auditory Display , 2021, p. 135-142Conference paper, Published paper (Refereed)
    Abstract [en]

    Data visualization software is commonly used to explore outer space in a planetarium environment, where the visuals of the software is typically accompanied with a narrator and supplementary background music. By letting sound take a bigger role in these kinds of presentations, a more informative and immersive experience can be achieved. The aim of the present study was to explore how sonification can be used as a complement to the visualization software OpenSpace to convey information about the Solar System, as well as increasing the perceived immersiveness for the audience in a planetarium environment. This was investigated by implementing a sonification that conveyed planetary properties, such as the size and orbital period of a planet, by mapping this data to sonification parameters. With a user-centered approach, the sonification was designed iteratively and evaluated in both an online and planetarium environment. The results of the evaluations show that the participants found the sonification informative and interesting, which suggest that sonification can be beneficially used as a complement to visualization in a planetarium environment.

    Place, publisher, year, edition, pages
    The International Community for Auditory Display, 2021
    Keywords
    Sonification, OpenSpace, Sonifiering
    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-183828 (URN)10.21785/icad2021.018 (DOI)0967090474 (ISBN)9780967090474 (ISBN)
    Conference
    International Conference on Auditory Display, an Online Conference, June 25–28, 2021
    Available from: 2022-04-11 Created: 2022-04-11 Last updated: 2025-03-21Bibliographically approved
    6. Birdsongification: Contextual and Complementary Sonification for Biology Visualization
    Open this publication in new window or tab >>Birdsongification: Contextual and Complementary Sonification for Biology Visualization
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    2024 (English)In: Proceedings of the International Conference on Auditory Display, ISSN 1093-9547, E-ISSN 2168-5126, p. 34-41Article in journal (Refereed) Published
    Abstract [en]

    Choosing whether to represent data in an abstract or concrete manner through sonification is generally dependent on the applicability of the dataset and personal preference of the designer. For supporting a visualization with a high level of abstraction, a sonification can purposefully act as a complement by giving concrete contextual cues to the data representation with the use of auditory icons. This paper presents a case study of using bird songs as auditory icons to give context to a biology visualization, and explores how additional information of the bird species can be conveyed together with the auditory icons with parameter mapping sonification. The auditory icons are used as a foundation to convey additional information of the dataset, either by creating a parametric auditory icon, or by adding an additional sonification that accompanies the auditory icon. A user evaluation was conducted to validate and compare the different sonification mappings. The results show that there is a subjective difference of how participants perceived the sonifications, where the participants preferred sonifications that had a concrete mapping design. The sonification approaches that are explored in this study have the potential to be applied to more general sonification designs.

    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-208608 (URN)10.21785/icad2024.006 (DOI)
    Conference
    29th International Conference on Auditory Display
    Funder
    Knut and Alice Wallenberg Foundation, 2019.0024
    Available from: 2024-10-17 Created: 2024-10-17 Last updated: 2025-03-21Bibliographically approved
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  • Public defence: 2025-04-29 09:00 Hasselquistsalen, building 511, LinköpingOrder onlineBuy this publication >>
    Hojjati, Sara
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences.
    Biomarkers for monitoring disease activity and predicting disease progression in multiple sclerosis: Studies on body fluid and imaging biomarkers2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Multiple sclerosis (MS) is a chronic neuroinflammatory and neurodegenerative disease driven by complex pathophysiological mechanisms that contribute to neurologic impairment and disability progression. This thesis explores protein and metabolite biomarkers and employs machine learning models to predict disease trajectory in MS, aiming to improve diagnosis, prognosis, and treatment response.

    To address this objective, comprehensive proteomic profiling was conducted on cerebrospinal fluid (CSF) and plasma from individuals with early-stage MS and healthy controls. Differentially expressed CSF proteins were enriched in pathways related to B cell activation, and a linear regression model incorporating 11 of these proteins and age effectively predicted long-term disability progression for up to 13 years. Additionally, logistic regression models based on CSF proteins could distinguish MS from controls and predict short-term disease activity.

    Since disease progression in MS is influenced not only by baseline pathology but also by therapeutic interventions, further focus was placed on how dimethyl fumarate (DMF), a common oral treatment in MS, affects plasma and CSF proteomic profiles related to pathological mechanisms in MS. Longitudinal analysis revealed DMF-induced reductions in inflammatory proteins associated with T-helper 1 immunity, underscoring the drug’s ability to modulate this key pathologic pathway. Importantly, baseline levels of specific axonal, glial and myelination-related proteins differentiated responders from non-responders, suggesting a potential role for these biomarkers in guiding treatment selection and optimizing therapeutic strategies.

    Expanding the focus beyond proteomics, metabolic dysregulation in MS was examined through the analysis of CSF and normal-appearing white matter (NAWM) metabolites across different disease stages. Metabolites that were most strongly associated with clinical factors in MS were linked to mitochondrial dysfunction, axonal integrity, astrogliosis and demyelination. CSF biomarkers in linear regression models could distinguish MS from unspecific but similar neurological symptoms and differentiate between subtypes of the disease. A random forest model incorporating NAWM metabolites demonstrated high predictive power for long-term disability progression for up to 16 years, offering a promising non-invasive tool for MS prognosis.

    Together, these studies provide a comprehensive perspective on MS pathophysiology, presenting protein- and metabolite-based models for enhanced diagnosis, treatment response monitoring, and long-term disease progression assessment. The biomarkers suggested in this thesis lay the groundwork for future translational applications in clinical practice.

    List of papers
    1. Proteomics reveal biomarkers for diagnosis, disease activity and long-term disability outcomes in multiple sclerosis
    Open this publication in new window or tab >>Proteomics reveal biomarkers for diagnosis, disease activity and long-term disability outcomes in multiple sclerosis
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    2023 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 14, no 1, article id 6903Article in journal (Refereed) Published
    Abstract [en]

    Sensitive and reliable protein biomarkers are needed to predict disease trajectory and personalize treatment strategies for multiple sclerosis (MS). Here, we use the highly sensitive proximity-extension assay combined with next-generation sequencing (Olink Explore) to quantify 1463 proteins in cerebrospinal fluid (CSF) and plasma from 143 people with early-stage MS and 43 healthy controls. With longitudinally followed discovery and replication cohorts, we identify CSF proteins that consistently predicted both short- and long-term disease progression. Lower levels of neurofilament light chain (NfL) in CSF is superior in predicting the absence of disease activity two years after sampling (replication AUC = 0.77) compared to all other tested proteins. Importantly, we also identify a combination of 11 CSF proteins (CXCL13, LTA, FCN2, ICAM3, LY9, SLAMF7, TYMP, CHI3L1, FYB1, TNFRSF1B and NfL) that predict the severity of disability worsening according to the normalized age-related MS severity score (replication AUC = 0.90). The identification of these proteins may help elucidate pathogenetic processes and might aid decisions on treatment strategies for persons with MS.

    Place, publisher, year, edition, pages
    NATURE PORTFOLIO, 2023
    National Category
    Neurosciences
    Identifiers
    urn:nbn:se:liu:diva-199196 (URN)10.1038/s41467-023-42682-9 (DOI)001129872400021 ()37903821 (PubMedID)
    Note

    Funding: The study was funded by the Swedish Foundation for Strategic Research (SB16-0011 [M.G., J.E.]), the Swedish Brain Foundation, Knut and Alice Wallenberg Foundation, and Margareth AF Ugglas Foundation, Swedish Research Council (2019-04193 [M.G.], 2018-02776 [J.E.], 2020-02700 [F.P.], 2020-00014 [Z.L.P.], 2021-03092 [J.E.]), the Medical Research Council of Southeast Sweden (FORSS-315121 [J.E.]), NEURO Sweden (F2018-0052 [J.E.]), ALF grants, Region Östergötland, the Swedish Foundation for MS Research and the European Union’s Marie Sklodowska-Curie (813863 [J.E.]). The authors would like to acknowledge support of the Clinical biomarker facility at SciLifeLab Sweden for providing assistance in protein analyses.

    Available from: 2023-11-16 Created: 2023-11-16 Last updated: 2025-03-31Bibliographically approved
    2. Dimethyl fumarate treatment in relapsing remitting MS changes the inflammatory CSF protein profile by a prominent decrease in T-helper 1 immunity
    Open this publication in new window or tab >>Dimethyl fumarate treatment in relapsing remitting MS changes the inflammatory CSF protein profile by a prominent decrease in T-helper 1 immunity
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    2023 (English)In: Multiple Sclerosis and Related Disorders, ISSN 2211-0348, E-ISSN 2211-0356, Vol. 80, article id 105126Article in journal (Refereed) Published
    Abstract [en]

    Background: Dimethyl fumarate (DMF) is a common treatment for multiple sclerosis (MS), but its mechanisms of action are not fully understood. Targeted proteomics offers insights into effects of DMF and biomarkers for treatment responses.Objectives: To assess influence of DMF on inflammation-and neuro-associated proteins in plasma and cerebro-spinal fluid (CSF) in MS and to reveal biomarkers for predicting treatment responses.Methods: Using the high-sensitivity and high-specificity method of proximity extension assay (PEA), we measured 182 inflammation-and neuro-associated proteins in paired plasma (n = 28) and CSF (n = 12) samples before and after one year of DMF treatment. Disease activity was evaluated through clinical examination and MRI. Statistical tests, network analysis, and regression models were used.Results: Several proteins including T-helper 1 (Th1)-associated proteins (CXCL10, CXCL11, granzyme A, IL-12p70, lymphotoxin-alpha) were consistently decreased in CSF, while IL-7 was increased after one year of treatment. The changes in plasma protein levels did not follow the same pattern as in CSF. Logistic regression models identified potential biomarker candidates (including plexins and neurotrophins) for prediction of treatment response.Conclusions: DMF treatment induced prominent changes in CSF proteins, consistently reducing Th1-associated pro-inflammatory proteins. Neurodegeneration-related CSF proteins were able to predict treatment response. Protein biomarkers hold promise for personalized medicine.

    Place, publisher, year, edition, pages
    ELSEVIER SCI LTD, 2023
    Keywords
    Multiple sclerosis; Biomarkers; Dimethyl fumarate; Targeted proteomics; Proximity extension assay; Inflammation; Neurodegeneration; Response to treatment
    National Category
    Immunology
    Identifiers
    urn:nbn:se:liu:diva-199686 (URN)10.1016/j.msard.2023.105126 (DOI)001112477000001 ()37952502 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [2018-02776, 2021-03092]; European Union [813863]; MIIC (Medical Infection and Inflammation Center, Linkoping University and Region Ostergotland, Sweden); ALF Grants, Region Ostergotland, Sweden

    Available from: 2023-12-19 Created: 2023-12-19 Last updated: 2025-03-31
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  • Public defence: 2025-04-30 09:00 Belladona, building 511, LinköpingOrder onlineBuy this publication >>
    Hiniesto Iñigo, Irene
    Linköping University, Department of Biomedical and Clinical Sciences, The Division of Cell and Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Modulation of the cardiac Kv7.1/KCNE1 channel by endocannabinoids and derivatives in the context of Long QT Syndrome2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Long QT Syndrome (LQTS) is a life-threatening cardiac channelopathy primarily caused by mutations in the KCNQ1 gene, leading to dysfunction of the KV7.1/KCNE1 channel complex, essential for proper repolarization of the ventricular action potential. These mutations predispose individuals to prolonged QT intervals and increased risk of arrhythmia. Despite current treatment options, such as β-blockers, these therapies do not address the root cause of the disease, and up to 30% of individuals remain at risk for cardiac events. Moreover, the clinical phenotypes of genotype-positive patients vary considerably, suggesting that factors beyond the primary mutation play a significant role. One possible explanation is the presence of endogenous compounds that modulate the KV7.1/KCNE1 channel.

    This thesis investigates the potential role of endocannabinoid compounds, which have emerged as key players in cardiovascular function, in modulating the KV7.1/KCNE1 channel. The primary technique employed in this thesis is the Two-electrode voltage clamp (TEVC) performed in Xenopus laevis oocytes expressing wild-type or mutated KV7.1/KCNE1 channels. Complementary Molecular Dynamic simulations were conducted to further explore the mechanism of action of these compounds. In addition, other electrophysiological techniques, including Automated and Manual Patch-clamp and Langendorff experiments, were used to assess the translational potential of these compounds in more complex systems.

    We demonstrated that endocannabinoids with a Serine head group, which are negatively charged at physiological pH, facilitate the activation of wild-type KV7.1/KCNE1 by interacting with KV7.1 at two distinct sites, resulting in a shift in voltage dependence to a negative direction along the voltage axis, and increase of maximal conductance. Furthermore, we showed that the endocannabinoid N-arachidonoyl-L-Serine (ARA-S) effectively activates a broad range of LQTS-associated KV7.1 mutants, even when its primary binding site is altered, with varying concentrations required to restore mutant channels to a wild-type-like behavior. The translational relevance of these findings is highlighted by the maintained effects of ARA-S in KV7.1/KCNE1 when expressed in mammalian cell lines and by shortening of the action potential duration in LQTS rabbit cardiomyocytes and a drug-induced LQTS model of isolated guinea pig hearts. Moreover, the development of synthetic endocannabinoids with structural tail modifications demonstrated potential for identifying novel activators of KV7.1/KCNE1.

    These findings highlight endocannabinoids as potential protective factors in LQTS, opening new possibilities for clinical management and therapeutic development.  

    List of papers
    1. Endocannabinoids enhance hKV7.1/KCNE1 channel function and shorten the cardiac action potential and QT interval
    Open this publication in new window or tab >>Endocannabinoids enhance hKV7.1/KCNE1 channel function and shorten the cardiac action potential and QT interval
    Show others...
    2023 (English)In: EBioMedicine, E-ISSN 2352-3964, Vol. 89Article in journal (Refereed) Published
    Abstract [en]

    Background Genotype-positive patients who suffer from the cardiac channelopathy Long QT Syndrome (LQTS) may display a spectrum of clinical phenotypes, with often unknown causes. Therefore, there is a need to identify factors influencing disease severity to move towards an individualized clinical management of LQTS. One possible factor influencing the disease phenotype is the endocannabinoid system, which has emerged as a modulator of cardio-vascular function. In this study, we aim to elucidate whether endocannabinoids target the cardiac voltage-gated potassium channel KV7.1/KCNE1, which is the most frequently mutated ion channel in LQTS.Methods We used two-electrode voltage clamp, molecular dynamics simulations and the E4031 drug-induced LQT2 model of ex-vivo guinea pig hearts.Findings We found a set of endocannabinoids that facilitate channel activation, seen as a shifted voltage-dependence of channel opening and increased overall current amplitude and conductance. We propose that negatively charged endocannabinoids interact with known lipid binding sites at positively charged amino acids on the channel, providing structural insights into why only specific endocannabinoids modulate KV7.1/KCNE1. Using the endocannabinoid ARA-S as a prototype, we show that the effect is not dependent on the KCNE1 subunit or the phosphorylation state of the channel. In guinea pig hearts, ARA-S was found to reverse the E4031-prolonged action potential duration and QT interval. Interpretation We consider the endocannabinoids as an interesting class of hKV7.1/KCNE1 channel modulators with putative protective effects in LQTS contexts.Copyright (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

    Place, publisher, year, edition, pages
    ELSEVIER, 2023
    Keywords
    Arrhythmia; Electrophysiology; KCNQ1; Kv7; Long QT Syndrome; Molecular dynamics
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:liu:diva-192694 (URN)10.1016/j.ebiom.2023.104459 (DOI)000947168000001 ()36796231 (PubMedID)
    Note

    Funding Agencies|ERC [850622]; Canadian Institutes of Health Research; Canada Research Chairs and Compute Canada; Swedish National Infrastructure for Computing

    Available from: 2023-03-29 Created: 2023-03-29 Last updated: 2025-03-28
    2. Rescue of loss-of-function long QT syndrome-associated mutations in K<sub>V</sub>7.1/KCNE1 by the endocannabinoid N-arachidonoyl-L-serine (ARA-S)
    Open this publication in new window or tab >>Rescue of loss-of-function long QT syndrome-associated mutations in K<sub>V</sub>7.1/KCNE1 by the endocannabinoid N-arachidonoyl-L-serine (ARA-S)
    Show others...
    2025 (English)In: British Journal of Pharmacology, ISSN 0007-1188, E-ISSN 1476-5381Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    Background and PurposeCongenital long QT syndrome (LQTS) involves genetic mutations affecting ion channels, leading to a prolonged QT interval and increased risk of potentially lethal ventricular arrhythmias. Mutations in the genes encoding KV7.1/KCNE1 are the most frequent, with channel loss-of-function contributing to LQTS. The endocannabinoid N-arachidonoyl-L-serine (ARA-S) has been shown to facilitate activation of wild type KV7.1/KCNE1 channels and to counteract a prolonged QT interval in isolated guinea pig hearts. In this study, we examine the ability of ARA-S to facilitate activation of LQTS-associated mutations, in various regions of the channel, and hence to counteract loss-of-function.Experimental ApproachThe two-electrode voltage clamp technique on Xenopus oocytes expressing human KV7.1/KCNE1 channels was used to investigate the effects of ARA-S in 20 LQTS type 1-associated mutations distributed across the channel. Thereafter, different electrophysiology was used to assess ARA-S effects in mammalian cells.Key ResultsARA-S enhanced the function of all mutated channels by shifting V50 and increasing current amplitude. However, the magnitude of effect varied, related to whether mutations were in one of the two putative ARA-S binding sites on the channel as suggested by molecular dynamics simulations. ARA-S displayed translational potential by facilitating channel opening in mammalian cells and shortening the action potential duration in cardiomyocytes.Conclusions and ImplicationsThis study demonstrates the rescuing capability of ARA-S on a diverse set of LQTS mutants. These insights may aid in developing drug compounds using ARA-S sites and mechanisms and guide interpretation of which LQTS mutants respond well to such compounds.

    Place, publisher, year, edition, pages
    WILEY, 2025
    Keywords
    arrhythmia; electrophysiology; KCNQ1; Kv7; molecular dynamics
    National Category
    Immunology in the Medical Area
    Identifiers
    urn:nbn:se:liu:diva-212543 (URN)10.1111/bph.70008 (DOI)001444401500001 ()40083204 (PubMedID)
    Note

    Funding Agencies|European Research Council (ERC) under the European Union [850622]; Konung Gustaf; Drottning Victorias Stiftelse; Swedish Research Council [2022-00844]; National Institutes of Health, National Heart, Lung, and Blood Institute [2R01HL131461-05]; Bern Center of Precision Medicine Lighthouse Grant 'PACE'; National Academic Infrastructure for Supercomputing in Sweden (NAISS) [2023/1-3, 2023/3-35]

    Available from: 2025-03-25 Created: 2025-03-25 Last updated: 2025-04-01
    3. The endocannabinoid ARA-S facilitates the activation of cardiac Kv7.1/KCNE1 channels from different species
    Open this publication in new window or tab >>The endocannabinoid ARA-S facilitates the activation of cardiac Kv7.1/KCNE1 channels from different species
    2024 (English)In: CHANNELS, ISSN 1933-6950, Vol. 18, no 1, article id 2420651Article in journal (Refereed) Published
    Abstract [en]

    The endogenous endocannabinoid-like compound N-arachidonoyl-L-serine (ARA-S) facilitates activation of the human Kv7.1/KCNE1 channel and shortens a prolonged action potential duration and QT interval in guinea pig hearts. Hence, ARA-S is interesting to study further in cardiac models to explore the functional impact of such Kv7.1/KCNE1-mediated effects. To guide which animal models would be suitable for assessing ARA-S effects, and to aid interpretation of findings in different experimental models, it is useful to know whether Kv7.1/KCNE1 channels from relevant species respond similarly to ARA-S. To this end, we used the two-electrode voltage clamp technique to compare the effects of ARA-S on Kv7.1/KCNE1 channels from guinea pig, rabbit, and human Kv7.1/KCNE1, when expressed in Xenopus laevis oocytes. We found that the activation of Kv7.1/KCNE1 channels from all tested species was facilitated by ARA-S, seen as a concentration-dependent shift in the voltage-dependence of channel opening and increase in current amplitude and conductance over a broad voltage range. The rabbit channel displayed quantitatively similar effects as the human channel, whereas the guinea pig channel responded with more prominent increase in current amplitude and maximal conductance. This study suggests that rabbit and guinea pig models are both suitable for studying ARA-S effects mediated via Kv7.1/KCNE1.

    Place, publisher, year, edition, pages
    TAYLOR & FRANCIS INC, 2024
    Keywords
    Electrophysiology; IKs; KCNQ1; lipid
    National Category
    Physiology and Anatomy
    Identifiers
    urn:nbn:se:liu:diva-209304 (URN)10.1080/19336950.2024.2420651 (DOI)001343181200001 ()39462453 (PubMedID)2-s2.0-85207374286 (Scopus ID)
    Note

    Funding Agencies|European Research Council (ERC) under the European Union [850622]

    Available from: 2024-11-11 Created: 2024-11-11 Last updated: 2025-03-28
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  • Public defence: 2025-05-06 13:15 K3, Kåkenhus, NorrköpingOrder onlineBuy this publication >>
    Citrohn, Björn
    Linköping University, Department of Behavioural Sciences and Learning, Division of Learning, Aesthetics, Natural Science. Linköping University, Faculty of Educational Sciences.
    Fysiska modeller i designprojekt: Om teknikkunskaper och didaktiska relationer i högstadiets teknikundervisning2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In Swedish compulsory school, physical models are used in design projects to develop, visualize, and understand technological solutions while also enhancing technological knowledge. This dissertation examines this usage with the aim to contribute to technology education research by exploring the role of physical models in design projects. The four articles in the dissertation are based on three empirical studies, with data collected through teacher interviews and video observations of technology education. The material, consisting of transcribed data from the studies, has been analyzed qualitatively using both inductive and deductive content analysis.

    The dissertation provides insights into how the availability of materials influences students' ability to develop physical models and express intentions with their final products. A limited range of materials can lead to simpler models that require additional forms of expression, affecting the didactic relationships between students, technological knowledge, and physical models. The findings also show that teachers, through the planning of a design project, can control the project's complexity and degree of freedom by focusing on different aspects of models and involving users and the environment. To facilitate the analysis of design projects, the dissertation presents an analytical tool for examining the technological knowledge offered in the project. Furthermore, the results indicate that teachers' perceptions and interpretations of technological knowledge and the use of models in technology education influence the technological knowledge students are provided. Finally, the dissertation demonstrates that students' work with models is an iterative and reflective process, where they, like engineers, use models to test, refine, and visualize their ideas.

    The implications are that material availability, constraints, and model usage in a project shape the technological knowledge students gain in design projects. By recognizing this relationship, researchers and teachers can contribute to the development of technology education research and teaching in schools. Lastly, the analytical tool presented in the dissertation can be used by teachers in project planning to assess in advance what technological knowledge students will acquire in the project.

    List of papers
    1. Technology teacher’s perceptions of model functions in technology education
    Open this publication in new window or tab >>Technology teacher’s perceptions of model functions in technology education
    2020 (English)In: International journal of technology and design education, ISSN 0957-7572, E-ISSN 1573-1804, Vol. 32, no 2, p. 805-823Article in journal (Refereed) Published
    Abstract [en]

    In this study we investigate how 11 Swedish technology teachers perceive model functions in technology education. The main reason for investigating model functions in technology is an identified lack of knowledge about, and research studies into, a conscious use of models when teaching technology, even though models are part of technology education in many countries. In order to answer the research question of how technology teachers perceive model functions in technology education, we have used directed content analysis where Nia and de Vries (J Technol Des Educ 27:627–653, 2017) model functions constituted a framework. The teachers connect model functions to two teaching contexts: Design process and Explain and facilitate understanding of technological solutions. Model functions are understood as parts of the design process which relate to technology/engineering knowledge, a prescriptive way of understanding models. Models are also used to explain and clarify specific technological situations or functions when teaching technology closely related to a scientific, descriptive way of using models. Five of Nia and de Vries model functions are identified in this empirical study. This strengthens the importance of addressing model functions in technological education.

    Place, publisher, year, edition, pages
    Springer, 2020
    Keywords
    Model function · Modelling · Technology teacher · Directed content analysis
    National Category
    Didactics
    Identifiers
    urn:nbn:se:liu:diva-197802 (URN)10.1007/s10798-020-09632-8 (DOI)000578244700001 ()2-s2.0-85092501485 (Scopus ID)
    Funder
    Linnaeus University
    Available from: 2023-09-14 Created: 2023-09-14 Last updated: 2025-04-01Bibliographically approved
    2. The use of models and modelling in design projects in three different technology classrooms
    Open this publication in new window or tab >>The use of models and modelling in design projects in three different technology classrooms
    2023 (English)In: International journal of technology and design education, ISSN 0957-7572, E-ISSN 1573-1804, Vol. 33, p. 63-90Article in journal (Refereed) Published
    Abstract [en]

    In this study, we aim to investigate activities using models in a design project in three technology classrooms. Activities that use models are important for students’ development of knowledge and skills connected to the design process. Nevertheless, few empirical studies have thus far examined how models and modelling are used in a classroom environment when students and teachers are involved in a design project. In order to meet our aim, we video-recorded eight lessons from three different technology classrooms (students aged 13–15), where the students were involved in diferent problem-solving activities using models and modelling. The three projects had diferent specifcations, and the students’ degrees of freedom thereby varied. The video recordings were analysed using a qualitative content analysis. The analysis resulted in seven activities being identifed where the teachers and students talked about models and modelling in order to solve the problem. The results also revealed three diferent dimensions of models: material, structure and function. These dimensions are present in almost all activities that use models. In a project with a high degree of freedom, all three dimensions of models are present. On the contrary, in a project with a lower freedom, only one of the dimensions is present, resulting in a lower degree of complexity for the students. The study emphasizes that the presumptions and openness of a design project in technology education can provide diferent possibilities for students learning in relation to models and modelling.

    Place, publisher, year, edition, pages
    Dordrecht, Netherlands: Springer Netherlands, 2023
    Keywords
    Models, Technology education, Activities, Design project, Dimensions of models
    National Category
    Didactics
    Identifiers
    urn:nbn:se:liu:diva-182679 (URN)10.1007/s10798-022-09730-9 (DOI)000749991800001 ()35125675 (PubMedID)
    Note

    Funding: Linnaeus University

    Available from: 2022-02-02 Created: 2022-02-02 Last updated: 2025-04-01Bibliographically approved
    3. Affordances of models and modelling: a study of four technology design projects in the Swedish secondary school
    Open this publication in new window or tab >>Affordances of models and modelling: a study of four technology design projects in the Swedish secondary school
    2022 (English)In: Design and Technology Education: An International Journal, ISSN 1360-1431, E-ISSN 2040-8633, Vol. 27, no 3, p. 58-75Article in journal (Refereed) Published
    Abstract [en]

    This study aims to investigate affordances of models and modelling in design projects in technology education. To learn more about affordances when working with models and modelling, four Swedish technology teachers were interviewed using a narrative approach. Despite a small number of informants data were rich, containing detailed descriptions of sequences where students used models and modelling in ways not planned by the teachers. By using a qualitative, generic inductive approach, the narrative interviews revealed seven different affordances of models and modelling in the projects: Seeing different solutions; Finding possibilities and limitations in solutions; Representing an idea, structure or function; Communicating solutions with drawings; Making problems and solutions visible; Trial and error and learning from mistakes and finally Taking inspirations from each other’s solutions. Some conclusions and implications of the study are that when the students can see and use a wide variety of materials when modelling, they are more creative in finding solutions to design problems. The use of conceptual design in schools, leading to students performing trial and error using models to solve problems, might also be connected to the importance of a variety of materials. In the study, teachers describe how their students used models, trying different solutions, representing ideas, and trying, failing and trying again. All these modelling activities are important parts of a design process and might prove that the doing itself is a process of reflection.

    Keywords
    Models, Modelling, Design project, Affordances, Technology Education
    National Category
    Didactics
    Identifiers
    urn:nbn:se:liu:diva-197801 (URN)
    Available from: 2023-09-14 Created: 2023-09-14 Last updated: 2025-04-01Bibliographically approved
    4. A framework for analyzing technological knowledge in school design projects including models
    Open this publication in new window or tab >>A framework for analyzing technological knowledge in school design projects including models
    2023 (English)In: Design and Technology Education: An International Journal, ISSN 1360-1431, E-ISSN 2040-8633, Vol. 28, no 2, p. 154-169Article in journal (Refereed) Published
    Abstract [en]

    This study investigates, and further develops, a framework for analyzing technological knowledge emanating from school design projects; a framework that has the potential to be used as a tool for teachers when choosing and planning design projects. The study also intends to answer the research question: What technological knowledge, associated to physical models, emanates from design projects common in Swedish secondary schools. To answer the research question, the framework is used to analyze three design projects common in Swedish secondary schools. The design projects were video-recorded during actual classroom work by using a self-following robot camera. The projects involved three teachers and 70 students in grades 7, 8 and 9. Deductive content analysis of the video-recordings revealed that technological knowledge from four categories–Technical skills, Technological scientific knowledge, Socio-ethical technical understanding and Engineering capabilities–within the framework emanated from the three projects. A new category of technological knowledge was also found, namely Technological research capabilities. This fifth category is related to the capability to search for, and interpret, information about solutions when doing a design. An implication of the conducted study is that design projects are important to enable development of technological knowledge in the school subject technology. However, considering the amount of time a design project requires, there is only room for a few projects in secondary school. Therefore, technology teachers have to carefully choose and combine projects to educate technological literate citizens as well as prepare students for studies and future careers within engineering and technology.

    Place, publisher, year, edition, pages
    Liverpool: , 2023
    National Category
    Didactics
    Identifiers
    urn:nbn:se:liu:diva-199474 (URN)
    Funder
    Linköpings universitet
    Available from: 2023-12-04 Created: 2023-12-04 Last updated: 2025-04-01
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  • Public defence: 2025-05-07 10:00 I:101, I-building, Linköping
    Kloo, Mattias
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    School Bullying and its Link to Authoritative Teaching and Peer Relations in the Classroom2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    From the day they start school, most children are placed into classrooms, surrounded by peers of approximately the same age with whom they are expected to spend several hours every school day for the next few years, overseen by their classroom teacher(s). The intense social interactions that follow within this classroom context lead not only to the formation of deep friendships between classmates but also to social frustration and animosities, which, in turn, risk developing into bullying.

    The overall aim of this thesis was to examine the link between bullying and different social factors within the classroom context. More specifically, these factors included authoritative teaching, classroom friendships, both individual and classroom friendship quality, and classroom sense of peer community. Student-report questionnaire data were collected from Swedish upper elementary school students through two longitudinal projects. The data were then analyzed using different forms of cross-sectional and longitudinal multi-level models.

    The findings from Study 1 showed that authoritative teaching was associated with both less bullying perpetration and victimization within the classroom. Furthermore, when examining the two dimensions of authoritative teaching (teacher structure and support) separately, only teacher support was significantly associated with bullying. Building on these results, Study 2 showed that the negative association between authoritative teaching and bullying victimization lasted throughout upper elementary school. However, the study also found that this association, while staying significant, weakened over time. In its examination of classroom peer relationships instead, Study 3 found individual friendlessness to be associated with a higher degree of bullying victimization, whereas a stronger sense of classroom peer community was associated with less victimization at a classroom level. Furthermore, both Studies 3 and 4 found higher quality friendships to be linked to less victimization at both the individual and classroom level. In its examination of specific friendship qualities, both Studies 3 and 4 found conflictual friendships to be linked to more victimization at both the individual and classroom level, whereas friendship help was only related to bullying victimization at the individual level. In addition, Study 4 found a negative association between friendship security and bullying victimization at both the individual and classroom levels, as well as a negative association between friendship companionship and victimization, but only at the classroom level. Finally, Study 4 found no credible interaction between friendship quality and time.

    In sum, these studies underscore the importance of viewing bullying as part of a complex interplay of social factors related to both the classroom teacher(s) and the relationships between classmates within a shared classroom context.

    List of papers
    1. Classroom-Level Authoritative Teaching and Its Associations with Bullying Perpetration and Victimization
    Open this publication in new window or tab >>Classroom-Level Authoritative Teaching and Its Associations with Bullying Perpetration and Victimization
    2023 (English)In: Journal of School Violence, ISSN 1538-8220, E-ISSN 1538-8239, Vol. 22, no 2, p. 276-289Article in journal (Refereed) Published
    Abstract [en]

    The aim of the present study was to investigate and clarify the association between authoritative teaching at the classroom level and bullying perpetration and victimization among Swedish upper elementary school students. For this purpose, authoritative teaching was analyzed both as combined construct, and as the effects of the two dimensions that characterize authoritative teaching (i.e. structure and support). In all, 1,522 students (M-age = 10.54 SD = 0.35) from 110 classrooms completed a questionnaire in their classrooms. The findings from the multilevel regression analyses showed that students in classrooms with less authoritative teachers engaged more in bullying behaviors and were more often victimized. When authoritative teaching was divided into structure and support, only teacher support showed a significant negative association with bullying perpetration and victimization.

    Place, publisher, year, edition, pages
    ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2023
    Keywords
    Bullying; victimization; authoritative teaching; teacher support; teacher structure; classroom
    National Category
    Public Health, Global Health and Social Medicine
    Identifiers
    urn:nbn:se:liu:diva-192687 (URN)10.1080/15388220.2023.2180746 (DOI)000937801100001 ()2-s2.0-85148522366 (Scopus ID)
    Note

    Funding Agencies|Vetenskapsradet [D0775301]

    Available from: 2023-03-29 Created: 2023-03-29 Last updated: 2025-04-04
    2. Longitudinal links of authoritative teaching and bullying victimization in upper elementary school
    Open this publication in new window or tab >>Longitudinal links of authoritative teaching and bullying victimization in upper elementary school
    2024 (English)In: Educational Psychology, ISSN 0144-3410, E-ISSN 1469-5820, Vol. 44, no 2, p. 171-188Article in journal (Refereed) Published
    Abstract [en]

    The aim of the present study was to investigate whether authoritative teaching at the classroom-level was associated with bullying victimisation, and how this association evolved over the course of upper elementary school (i.e. in grades 4 through 6) by estimating whether the association declined with time. Data came from the first three waves of an ongoing longitudinal project examining social and moral correlates of school bullying. Survey data were analysed from 1,830 students. Multilevel analyses showed that teachers who displayed high levels of warmth, caring, and supportiveness together with high levels of structure, control, and demandingness tended to have students who reported less bullying victimisation. This association between authoritative teaching at the classroom-level and bullying victimisation, while still significant, decreased over the course of the two-year study.

    Place, publisher, year, edition, pages
    ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2024
    Keywords
    Authoritative teaching; authoritative teacher; classroom management; bullying; victimisation
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-201668 (URN)10.1080/01443410.2024.2325594 (DOI)001176545500001 ()2-s2.0-85187119185 (Scopus ID)
    Note

    Funding Agencies|Robert Thornberg by the Swedish Research Council

    Available from: 2024-03-19 Created: 2024-03-19 Last updated: 2025-04-04Bibliographically approved
    3. Individual and classroom-level associations of within classroom friendships, friendship quality and a sense of peer community on bullying victimization
    Open this publication in new window or tab >>Individual and classroom-level associations of within classroom friendships, friendship quality and a sense of peer community on bullying victimization
    2025 (English)In: Social Psychology of Education, ISSN 1381-2890, E-ISSN 1573-1928, Vol. 28, no 1, article id 42Article in journal (Refereed) Published
    Abstract [en]

    For most students, attending school entails daily intense social interactions with classmates in a classroom context. While many of these interactions are positive and lead to the development of friendships and a shared classroom community, some students instead suffer peer harassment and bullying. According to the social-ecological theory these disparate social phenomena may be linked. The aim of this study was to examine how number of friends, perceived friendship quality, and a sense of peer community were associated with bullying victimization at both the individual and classroom level. Additionally, to thoroughly investigate the nuances of different types of friendship qualities the concept was analyzed both as one unified construct and as five distinct dimensions (companionship, conflict, help, security, and closeness). Survey data from 587 Swedish upper elementary school students (56.22% girls; Mage = 11.72, SD = 0.96) across 54 classrooms was collected and analyzed using multilevel regression. Results showed that having at least one friend was negatively associated with victimization and that victimization was less prevalent in classrooms where students experienced a shared sense of community. Furthermore, while high-quality friendships were associated with less victimization at both the individual and classroom level, when the five dimensions where considered, only conflictual and helpful friendships were significantly associated with victimization (on both levels of analysis for conflictual friendships and only on the individual level for helpful friendships). Together these results highlights the importance of schools helping students cultivate high-quality friendships, teaching constructive conflict management and promoting a more prosocial classroom community.

    Place, publisher, year, edition, pages
    SPRINGER, 2025
    Keywords
    Bullying; Peer victimization; Peer friendships; Classroom climate
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-211563 (URN)10.1007/s11218-025-10027-7 (DOI)001407791600001 ()
    Note

    Funding Agencies|Linkoping University

    Available from: 2025-02-10 Created: 2025-02-10 Last updated: 2025-04-04
  • Public defence: 2025-05-08 09:00 Belladonna, Växthuset, LinköpingOrder onlineBuy this publication >>
    Larsson, Alexander
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences.
    Exploring Novel Treatments for Wounds2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wound healing is a complex and dynamic process involving the interplay of various cellular and molecular mechanisms aimed at restoring skin integrity and function. Burns, a common type of acute wound, represent a significant challenge due to their high morbidity. Effective burn wound management requires advanced therapeutic strategies that create a favorable environment for healing through wound care, the use of advanced wound dressings, and surgical interventions including skin transplantation. There has been growing interest in novel approaches, such as biomaterials and cell-based therapies, which offer promising solutions for improving wound healing outcomes. This thesis explores innovative treatments designed to enhance wound healing, focusing on creating an optimal wound environment through assisted debridement and the use of biomaterials for dressings, dermal substitutes, and scaffolds for autologous cells.

    In paper I, the potential of porous gelatin microcarriers (PGM) as a scaffold for delivering autologous keratinocytes and fibroblasts to wounds was investigated. In vitro experiments demonstrated that PGM supports cell attachment and proliferation, with an optimal transplantation time identified within 24 to 96 hours. Using a porcine model, wounds treated with cell-seeded PGM exhibited improved re-epithelialization compared to single-cell suspensions and untreated controls. Histological analysis revealed that the PGM were degraded within four weeks and supported the formation of a mature neo-epidermis, demonstrating its potential as an efficient and time-saving alternative to traditional cultured epidermal autografts.

    The study presented in paper II assessed the efficacy of amino acid-buffered hypochlorite (AABH) as a debridement agent in an infected porcine burn model. AABH, in combination with mechanical debridement, was compared to mechanical debridement alone and untreated controls. AABH significantly improved the removal of necrotic tissue, reduced bacterial load, and promoted wound healing. These findings suggest that AABH could serve as an effective and accessible tool for wound debridement, particularly in settings where specialized surgical expertise is limited.

    In paper III, a randomized clinical trial compared a bacterial cellulose (BC) dressing to a porcine xenograft (PX) dressing for treating partial-thickness burns. Wounds treated with the BC dressing demonstrated healing times comparable to those of the PX dressing. Additionally, there were no significant differences in infection rates, pain, impact on everyday life, length of hospital stay, dressing costs, need for surgical interventions, or scar assessment when comparing the two dressings. In conclusion, BC demonstrated equivalent effectiveness to PX, making it an alternative for burn wound management. Furthermore, a significant advantage of BC is that it is not animal-derived, addressing ethical and cultural concerns.

    The study presented in paper IV explored the use of recombinant spider silk modified with bioactive fibronectin motifs (FN-silk) as a dermal substitute. Using a porcine full-thickness wound model, FN-silk was compared to the collagen-based matrix MatriDerm®. FN-silk demonstrated excellent biocompatibility, and the material was gradually degraded in vivo. Wounds treated with FN-silk displayed significantly enhanced re-epithelialization and higher elasticity compared to those treated with MatriDerm® or untreated controls. These results highlight FN-silk's potential as a next-generation biomaterial for promoting epidermal healing and dermal regeneration.

    List of papers
    1. Transplantation of autologous cells and porous gelatin microcarriers to promote wound healing
    Open this publication in new window or tab >>Transplantation of autologous cells and porous gelatin microcarriers to promote wound healing
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    2021 (English)In: Burns, ISSN 0305-4179, E-ISSN 1879-1409, Vol. 47, no 3, p. 601-610Article in journal (Refereed) Published
    Abstract [en]

    Definitive treatment to achieve wound healing in major burns frequently include skin transplantation, where split-thickness skin grafts is considered gold standard. This method is associated with several drawbacks. To overcome these hurdles, efforts have been made to develop tissue engineered skin substitutes, often comprised of a combination of cells and biomaterials. In the present study, we aimed to investigate transplantation of autologous keratinocytes and fibroblasts seeded on porous gelatin microcarriers using a porcine wound model. Pre-seeded microcarriers were transplanted to a total of 168 surgical full-thickness wounds (2 cm diameter) on eight adult female pigs and covered with occlusive dressings. The experimental groups included wounds transplanted with microcarriers seeded with the combination of keratinocytes and fibroblasts, microcarriers seeded with each cell type individually, microcarriers without cells, each cell type in suspension, and NaCl control. Wounds were allowed to heal for one, two, four or eight weeks before being excised and fixated for subsequent histological and immunohistochemical analysis. In vitro, we confirmed that viable cells populate the surface and the pores of the microcarriers. In vivo, the microcarriers were to a large extent degraded after two weeks. After one week, all treatment groups, with the exception of microcarriers alone, displayed significantly thicker neo-epidermis compared to controls. After two weeks, wounds transplanted with microcarriers seeded with cells displayed significantly thicker neo-epidermis compared to controls. After four weeks there was no difference in the thickness of neo-epidermis. In conclusion, the experiments performed illustrate that autologous cells seeded on porous gelatin microcarriers stimulates the re-epithelialization of wounds. This method could be a promising candidate for skin transplantation. Future studies will focus on additional outcome parameters to evaluate long-term quality of healing following transplantation. (c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

    Place, publisher, year, edition, pages
    Elsevier Science Ltd, 2021
    Keywords
    Burns; Wound healing; Transplantation; Tissue engineering; Guided tissue regeneration
    National Category
    Cell and Molecular Biology
    Identifiers
    urn:nbn:se:liu:diva-176186 (URN)10.1016/j.burns.2020.08.003 (DOI)000649382400012 ()32843238 (PubMedID)
    Note

    Funding Agencies|Swedish government [LIO-834921]; county councils, the ALF-agreement [LIO-834921]

    Available from: 2021-06-09 Created: 2021-06-09 Last updated: 2025-03-26
    2. Amino acid buffered hypochlorite facilitates debridement of porcine infected burn wounds
    Open this publication in new window or tab >>Amino acid buffered hypochlorite facilitates debridement of porcine infected burn wounds
    2023 (English)In: Burns, ISSN 0305-4179, E-ISSN 1879-1409, Vol. 49, no 6, p. 1363-1371Article in journal (Refereed) Published
    Abstract [en]

    Introduction: Removal of necrotic tissue is a vital step in the treatment of full-thickness burn wounds, with surgical debridement being the most effective method. Since minor burn wounds are typically treated on an outpatient basis where surgical capabilities can be limited there is a need for alternative treatment options. In this study we aim to evaluate the use of amino acid buffered hypochlorite (AABH) as a chemical enhancement for wound debridement in a porcine infected burn wound model.Method: A total of 60 full-thickness burn wounds, 3 cm in diameter, were created on four pigs using a standardized burn device. The wounds were inoculated with 107 colonyforming units (CFU) of S. aureus. The experimental groups included wounds debrided with a plastic curette, wounds debrided after pretreatment with AABH, and control wounds wiped with gauze. Wounds were treated twice per week for three weeks. Debridement, healing, and infection parameters were evaluated over time.Results: After one week, but not after two and three weeks, the curette and AABH groups had higher debrided weights compared to control (p &lt; 0.05). Percentage of wound area adequately cleared from necrotic tissue was higher in the AABH-group compared to the curette-group and control, after one week. The earliest healing was measured in the AABH group after two weeks (5 % of wounds), which also had the most healed wounds after three weeks (55 %). In both the AABH and the curette groups, bacterial load had fallen below 10(5) CFU/g after two weeks. No CFU were detectable in the AABH group after three weeks. The AABH-group was also the easiest to debride.Conclusion: Our results indicate that AABH facilitates wound debridement and could be a helpful addition to an effective treatment modality for removal of necrotic tissue in full thickness burns.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

    Place, publisher, year, edition, pages
    Elsevier, 2023
    Keywords
    Debridement; Burns; Hypochlorite; Porcine model
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-198390 (URN)10.1016/j.burns.2022.11.011 (DOI)001074068400001 ()36543728 (PubMedID)
    Note

    Funding Agencies|RLS Global AB, Sweden

    Available from: 2023-10-10 Created: 2023-10-10 Last updated: 2025-03-26
    3. Biosynthetic cellulose compared to porcine xenograft in the treatment of partial-thickness burns: A randomised clinical trial
    Open this publication in new window or tab >>Biosynthetic cellulose compared to porcine xenograft in the treatment of partial-thickness burns: A randomised clinical trial
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    2022 (English)In: Burns, ISSN 0305-4179, E-ISSN 1879-1409, Vol. 48, no 5, p. 1236-1245Article in journal (Refereed) Published
    Abstract [en]

    Aim: The aim was to compare two dressing treatments for partial-thickness burns: biosynthetic cellulose dressing (BsC) (Epiprotect (R) S2Medical AB, Linkoping, Sweden) and porcine xenograft (EZ Derm (R), Molnlycke Health Care, Gothenburg, Sweden). Methods: Twenty-four adults with partial-thickness burns were included in this randomized clinical trial conducted at The Burn Centers in Linkoping and Uppsala, Sweden between June 2016 and November 2018. Time to healing was the primary outcome. Secondary outcomes were wound infection, pain, impact on everyday life, length of hospital stay, cost, and burn scar outcome (evaluated with POSAS). Results: We found no significant differences between the two dressing groups regarding time to healing, wound infection, pain, impact on everyday life, duration of hospital stay, cost, or burn scar outcome at the first follow up. Burn scar outcome at the 12-month follow up showed that the porcine xenograft group patients scored their scars higher on the POSAS items thickness (p = 0.048) and relief (p = 0.050). This difference was, however, not confirmed by the observer. Conclusions: The results showed the dressings performed similarly when used in adults with burns evaluated as partial thickness. (C) 2021 The Authors. Published by Elsevier Ltd.

    Place, publisher, year, edition, pages
    Elsevier Science Ltd, 2022
    Keywords
    Burn wound dressing; Cellulose dressing; Healing time; Partial thickness burn; Porcine skin
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-188627 (URN)10.1016/j.burns.2021.09.017 (DOI)000849634500024 ()34629186 (PubMedID)
    Available from: 2022-09-20 Created: 2022-09-20 Last updated: 2025-03-26
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  • Public defence: 2025-05-08 13:00 Granitsalen, LinköpingOrder onlineBuy this publication >>
    Bäck, Sophia
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Personalized Analysis of Left Atrial Blood Flow through Computational Modeling2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, the atrial blood flow was modeled using computational fluid dynamics (CFD) to better understand atrial hemodynamics and blood stasis. Atrial hemodynamics and especially stasis are of interest since thrombi can form in the left atrium, travel with the blood stream to the brain, and cause strokes. To model atrial blood flow in a personalized manner, several modeling assumptions and choices need to be made, for example how to model the motion of the atrial wall. There are different approaches to estimate stasis; however, there is no standard method. While it is known that in patients with atrial fibrillation (AF), the stroke risk is increased, the exact mechanisms for this are not fully understood, especially in patients that are in sinus rhythm most of the time. One approach to reduce the stroke risk is to occlude the left atrial appendage (LAA). However, this has not been evaluated for patients in an early phase of AF.

    The aim of this thesis was to enhance our understanding of left atrial hemodynamics. For this, the blood flow in the left atrium was simulated using CFD based on time-resolved CT images, including the patient-specific geometry and wall motion. In this thesis, different stasis markers are investigated and a new method to quantify atrial hemodynamics was developed, splitting the atrial blood flow into 6 components. Additionally, virtual LAA occlusion was investigated to see how it impacts atrial hemodynamics during sinus rhythm.

    In this thesis, the atrial blood flow and stasis in 21 paroxysmal AF patients during sinus rhythm were compared to 8 controls. The wall motion tracked from time-resolved CT that was used in the CFD simulations showed similar flow rates as measurements from 4D flow MRI. All stasis markers investigated showed higher stasis in AF patients during sinus rhythm compared to the controls. Atrial flow component analysis revealed how blood travels through the left atrium. In the control group, the blood flow was dominated by components characterizing a direct path through the LA. In the patients with AF, however, an increased amount of blood stays in the LA for more than two heart beats and more blood flows back to the lungs. Virtual LAAO showed a reduction of stasis, for some individuals to similar levels as the control group. For others, stasis was reduced but still high, and stasis was located close to the occlusion device. This could indicate an increased risk for device-related thrombi.

    In conclusion, this thesis contributes to our understanding of the atrial blood flow. Using CT-based CFD simulations, we could show that stasis is increased in AF patients during sinus rhythm. In the future, adding patient-specific stasis assessment could improve decision-making to prescribe anticoagulants and thus reduce the incidence of cardioembolic strokes.

    List of papers
    1. Assessment of transmitral and left atrial appendage flow rate from cardiac 4D-CT
    Open this publication in new window or tab >>Assessment of transmitral and left atrial appendage flow rate from cardiac 4D-CT
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    2023 (English)In: Communications Medicine, E-ISSN 2730-664X, Vol. 3, no 1, article id 22Article in journal (Refereed) Published
    Abstract [en]

    Plain language summaryAssessing the blood flow inside the heart is important in diagnosis and treatment of various cardiovascular diseases, such as atrial fibrillation or heart failure. We developed a method to accurately track the motion of the heart walls over the course of a heartbeat in three-dimensional Computed Tomography (CT) images. Based on the motion, we calculated the amount of blood passing through the mitral valve and the left atrial appendage orifice, which are markers used in the diagnostic of heart failure and assessment of stroke risk in atrial fibrillation. The results agreed well with measurements from 4D flow MRI, an imaging technique that measures blood velocities. Our method could broaden the use of CT and make additional exams redundant. It can even be used to calculate the blood flow inside the heart. BackgroundCardiac time-resolved CT (4D-CT) acquisitions provide high quality anatomical images of the heart. However, some cardiac diseases require assessment of blood flow in the heart. Diastolic dysfunction, for instance, is diagnosed by measuring the flow through the mitral valve (MV), while in atrial fibrillation, the flow through the left atrial appendage (LAA) indicates the risk for thrombus formation. Accurate validated techniques to extract this information from 4D-CT have been lacking, however.MethodsTo measure the flow rate though the MV and the LAA from 4D-CT, we developed a motion tracking algorithm that performs a nonrigid deformation of the surface separating the blood pool from the myocardium. To improve the tracking of the LAA, this region was deformed separately from the left atrium and left ventricle. We compared the CT based flow with 4D flow and short axis MRI data from the same individual in 9 patients.ResultsFor the mitral valve flow, good agreement was found for the time span between the early and late diastolic peak flow (bias: &lt;0.1 s). The ventricular stroke volume is similar compared to short-axis MRI (bias 3 ml). There are larger differences in the diastolic peak flow rates, with a larger bias for the early flow rate than the late flow rate. The peak LAA outflow rate measured with both modalities matches well (bias: -6 ml/s).ConclusionsOverall, the developed algorithm provides accurate tracking of dynamic cardiac geometries resulting in similar flow rates at the MV and LAA compared to 4D flow MRI. Back et al. describe a motion tracking algorithm to measure the flow rate through the mitral valve (MV) and the left atrial appendage (LAA) from 4D-CT data. The developed algorithm provided accurate tracking of dynamic cardiac geometries resulting in similar flow rates at the MV and LAA to those measured by 4D flow MRI.

    Place, publisher, year, edition, pages
    Springer Nature, 2023
    National Category
    Medical Laboratory Technologies
    Identifiers
    urn:nbn:se:liu:diva-192697 (URN)10.1038/s43856-023-00252-6 (DOI)000942301600002 ()36774374 (PubMedID)
    Available from: 2023-03-29 Created: 2023-03-29 Last updated: 2025-04-02
    2. Elevated atrial blood stasis in paroxysmal atrial fibrillation during sinus rhythm: a patient-specific computational fluid dynamics study
    Open this publication in new window or tab >>Elevated atrial blood stasis in paroxysmal atrial fibrillation during sinus rhythm: a patient-specific computational fluid dynamics study
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    2023 (English)In: Frontiers in Cardiovascular Medicine, E-ISSN 2297-055X, Vol. 10, article id 1219021Article in journal (Refereed) Published
    Abstract [en]

    Introduction: Atrial fibrillation (AF) is associated with an increased risk of stroke, often caused by thrombi that form in the left atrium (LA), and especially in the left atrial appendage (LAA). The underlying mechanism is not fully understood but is thought to be related to stagnant blood flow, which might be present despite sinus rhythm. However, measuring blood flow and stasis in the LAA is challenging due to its small size and low velocities. We aimed to compare the blood flow and stasis in the left atrium of paroxysmal AF patients with controls using computational fluid dynamics (CFD) simulations.Methods : The CFD simulations were based on time-resolved computed tomography including the patient-specific cardiac motion. The pipeline allowed for analysis of 21 patients with paroxysmal AF and 8 controls. Stasis was estimated by computing the blood residence time.Results and Discussion: Residence time was elevated in the AF group (p &lt; 0.001). Linear regression analysis revealed that stasis was strongest associated with LA ejection ratio (p &lt; 0.001, R-2 = 0.68) and the ratio of LA volume and left ventricular stroke volume (p &lt; 0.001, R-2 = 0.81). Stroke risk due to LA thrombi could already be elevated in AF patients during sinus rhythm. In the future, patient specific CFD simulations may add to the assessment of this risk and support diagnosis and treatment.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2023
    Keywords
    atrial fibrillation; computational fluid dynamics; left atrial appendage; computed tomography; atrial cardiomyopathy; stroke
    National Category
    Cardiology and Cardiovascular Disease
    Identifiers
    urn:nbn:se:liu:diva-197884 (URN)10.3389/fcvm.2023.1219021 (DOI)001059086800001 ()37649669 (PubMedID)
    Note

    Funding Agencies|This project was funded by the Swedish Medical Research Council (2018-02779); the Swedish research council (2018-04454), ALF Grants, Region Ouml;stergouml;tland (974839 and 969563); Swedish Heart and Lung Foundation (20200220 and 20210441), VINNOVA (2019 [2018-04454]; Swedish Medical Research Council [974839]; Swedish research council [969563, 20200220]; ALF Grants [20210441, 2019-02261]; Swedish Heart and Lung Foundation [2021/3-35]; VINNOVA; Henry och Ella Sthls foundation; Swedish National Infrastructure for Computing (SNIC) - Swedish Research Council; [2018-02779]

    Available from: 2023-09-19 Created: 2023-09-19 Last updated: 2025-04-02
    3. Comprehensive left atrial flow component analysis reveals abnormal flow patterns in paroxysmal atrial fibrillation
    Open this publication in new window or tab >>Comprehensive left atrial flow component analysis reveals abnormal flow patterns in paroxysmal atrial fibrillation
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    2024 (English)In: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 326, no 3, p. H511-H521Article in journal (Refereed) Published
    Abstract [en]

    Left atrial (LA) blood flow plays an important role in diseases such as atrial fibrillation (AF) and atrial cardiomyopathy since alterations in the blood flow might lead to thrombus formation and stroke. Using traditional techniques, such as echocardiography, atrial flow velocities can be measured at the pulmonary veins and the mitral valve, but a comprehensive understanding of the three-dimensional atrial flow field is missing. Previously, ventricular flow has been analyzed using flow component analysis, revealing new insights into ventricular flow and function. Thus, the aim of this project was to develop a comprehensive flow component analysis method for the LA and explore its utility in 21 patients with paroxysmal atrial fibrillation compared with a control group of 8 participants. The flow field was derived from time-resolved CT acquired during sinus rhythm using computational fluid dynamics. Flow components were computed from particle tracking. We identified six atrial flow components: conduit, reservoir, delayed ejection, retained inflow, residual volume, and pulmonary vein backflow. It was shown that conduit flow, defined as blood entering and leaving the LA within the same diastolic phase, exists in most subjects. Although the volume of conduit and reservoir is similar in patients with paroxysmal AF in sinus rhythm and controls, the volume of the other components is increased in paroxysmal AF. Comprehensive quantification of LA flow using flow component analysis makes atrial blood flow quantifiable, thus facilitating investigation of mechanisms underlying atrial dysfunction and can increase understanding of atrial blood flow in disease progression and stroke risk. NEW & NOTEWORTHY We developed a new comprehensive approach to atrial blood component analysis that includes both conduit flow and residual volume and compared the flow components of atrial fibrillation (AF) patients in sinus rhythm with controls. Conduit and reservoir flow were similar between the groups, whereas components with longer residence time in the left atrium were increased in the AF group. This could add to the pathophysiological understanding of atrial diseases and possibly clinical management.

    Place, publisher, year, edition, pages
    AMER PHYSIOLOGICAL SOC, 2024
    Keywords
    atrial fibrillation; flow component analysis; hemodynamics; left atrium
    National Category
    Cardiology and Cardiovascular Disease
    Identifiers
    urn:nbn:se:liu:diva-202504 (URN)10.1152/ajpheart.00614.2023 (DOI)001180537400005 ()38133621 (PubMedID)
    Note

    Funding Agencies|Region Ostergotland Grants [974839, RO-987498]; Swedish Heart and Lung Foundation [20200220, 20210441]; Swedish Research Council [2018-02779, 2022-03931]; Sweden's Innovation Agency Vinnova Grant [2019-02261]

    Available from: 2024-04-16 Created: 2024-04-16 Last updated: 2025-04-02
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  • Public defence: 2025-05-09 09:00 Aulan, JönköpingOrder onlineBuy this publication >>
    Magnusson, Cecilia
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences. Department of Infectious Diseases, Region Jönköping County, Jönköping, Sweden.
    Outbreak epidemiology, virulence and quality of life in Clostridioides difficile infection2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Clostridioides difficile is a toxigenic, anaerobic spore-forming bacterium. C. difficile infection (CDI) is the leading cause of healthcare-associated diarrhea and pseudomembranous colitis, particularly in elderly, hospitalized patients that have received antibiotic treatment.

    The aims of this thesis were to investigate the molecular epidemiology, transmission and virulence of CDI in Region Jönköping County, including a local outbreak of C. difficile ribotype (RT) 046. Additionally, the thesis aimed to assess the impact of fecal microbiota transplantation (FMT) on the health related quality of life (HRQoL) in patients with recurrent CDI (rCDI).

    In paper I we collected and ribotyped C. difficile isolates from patients in the county during one year. Two different RTs, RT 001 and RT 012, were associated with nosocomial transmission. In paper II we analyzed a large local outbreak dominated by RT 046 using ribotyping and whole genome sequencing to explore epidemiological links. Furthermore the virulence of RT 046 was assessed, and interventions implemented to stop the outbreak were evaluated. RT 046 was widely spread throughout Högland Hospital, and was associated with a higher mortality compared to other strains. In paper III, toxin production and sporulation capacity in epidemic RT 046 were compared to other less prominent RTs. RT 046 produced higher levels of toxin and exhibited a higher degree of antibiotic resistance compared to the other strains from the outbreak. Finally, in paper IV we evaluated the HRQoL in patients with rCDI before and after treatment with FMT. We found that patients with rCDI had low HRQoL which increased significantly after treatment with FMT.

    List of papers
    1. Ribotyping of lostridium difficile strains associated with nosocomial transmission and relapses in a Swedish County
    Open this publication in new window or tab >>Ribotyping of lostridium difficile strains associated with nosocomial transmission and relapses in a Swedish County
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    2013 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 121, no 2, p. 153-157Article in journal (Refereed) Published
    Abstract [en]

    Clostridium difficile is an emerging threat in hospital environments. To analyse possible transmission and to distinguish between relapse and reinfection a collection of C. difficile isolates, sampled from 162 consecutive episodes of C. difficile infection, were PCR ribotyped. Two ribotypes (001 and 012) were prone to cause nosocomial acquisition. Moreover, ribotype 001 had a tendency to cause relapses as almost one in two patients with this ribotype had one or more relapses. By using PCR ribotyping strains inclined to cause relapses and strains associated with hospital transmission might be detected. This enables optimized hygiene measures and may improve the choice of treatment regimen.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2013
    Keywords
    Clostridium difficile, molecular epidemiology, ribotyping, transmission, CDI, hygiene measures
    National Category
    Infectious Medicine
    Identifiers
    urn:nbn:se:liu:diva-212778 (URN)10.1111/j.1600-0463.2012.02950.x (DOI)000313830700009 ()23030627 (PubMedID)2-s2.0-84872665873 (Scopus ID)
    Note

    Funding: Financial support was received from Futurum The Academy of Healthcare, County Council of Jönköping, Sweden.

    Available from: 2025-04-02 Created: 2025-04-02 Last updated: 2025-04-02Bibliographically approved
    2. Characterization of a Clostridioides difficile outbreak caused by PCR ribotype 046, associated with increased mortality
    Open this publication in new window or tab >>Characterization of a Clostridioides difficile outbreak caused by PCR ribotype 046, associated with increased mortality
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    2022 (English)In: Emerging Microbes & Infections, E-ISSN 2222-1751, Vol. 11, no 1, p. 850-859Article in journal (Refereed) Published
    Abstract [en]

    This study describes a large nosocomial outbreak of Clostridioides difficile infections (CDI) dominated by ribotype (RT) 046 in a Swedish hospital. The present study aimed to examine the pathogenicity of this RT, explore epidemiological links by whole genome sequencing (WGS), and evaluate different interventions implemented to stop the outbreak. Clinical isolates (n = 366) collected during and after the outbreak were ribotyped and 246 isolates were subjected to WGS. Medical records of patients infected with the seven most common RTs were evaluated. RT046 was spread effectively throughout the hospital and was the most common among the 44 different RTs found (114/366 isolates). Infection with RT046 was associated with higher mortality compared to other strains (20.2% to 7.8%), although there were no differences in concomitant disease, age or antibiotic treatment. To control the outbreak, several measures were successfully implemented.

    Place, publisher, year, edition, pages
    Taylor & Francis Ltd, 2022
    Keywords
    Clostridioides difficile; CDI; mortality; outbreak; epidemiology; ribotyping; whole-genome sequencing
    National Category
    Infectious Medicine
    Identifiers
    urn:nbn:se:liu:diva-184057 (URN)10.1080/22221751.2022.2049981 (DOI)000771404100001 ()35240942 (PubMedID)
    Note

    Funding: Academy for Health and Care, Region Jonkoping County, Sweden

    Available from: 2022-04-04 Created: 2022-04-04 Last updated: 2025-04-02
    3. Improved health-related quality of life in patients with recurrent Clostridioides difficile infection after treatment with faecal microbiota transplantation
    Open this publication in new window or tab >>Improved health-related quality of life in patients with recurrent Clostridioides difficile infection after treatment with faecal microbiota transplantation
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    2024 (English)In: Infectious Diseases, ISSN 2374-4235, E-ISSN 2374-4243Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    BackgroundClostridioides difficile is a major burden for both healthcare systems and the patients. Faecal microbiota transplantation (FMT) is becoming more common as a treatment since it reduces the risk of recurrent Clostridioides difficile infection (rCDI).ObjectivesTo evaluate how treatment with FMT is affecting the health-related quality of life (HRQoL) in patients with rCDI.MethodsA prospective observational cohort study was conducted where patients who were offered FMT as a treatment for rCDI were asked to fill in a questionnaire based on the Short Health Scale (SHS) and EuroQol 5-Dimensions 5-Levels (EQ-5D-5L) about their HRQoL before and after treatment.ResultsPatients with rCDI had poor HRQoL, which improved following FMT.ConclusionsSince FMT cures, reduces the risk of new recurrences of CDI and improves the HRQoL of the patients, it should be offered as a treatment for patients with rCDI. Also, SHS is a useful and reliable instrument for measuring HRQoL in patients with rCDI.

    Place, publisher, year, edition, pages
    TAYLOR & FRANCIS LTD, 2024
    Keywords
    ; faecal microbiota transplantation; Short Health Scale
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-209330 (URN)10.1080/23744235.2024.2415694 (DOI)001343047000001 ()39460926 (PubMedID)2-s2.0-85208134144 (Scopus ID)
    Note

    Funding Agencies|Academy for Health and Care, Region Jonkoping County, Medical Research Council of Southeast Sweden; Region Ostergotland, Sweden

    Available from: 2024-11-12 Created: 2024-11-12 Last updated: 2025-04-02
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  • Public defence: 2025-05-09 13:00 Hasselquistsalen, LinköpingOrder onlineBuy this publication >>
    Karlsson, Jesper
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection. Linköping University, Faculty of Medicine and Health Sciences.
    Autoreactivity to protective molecules in systemic lupus erythematosus2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease primarily affecting women of young age. It is a multi-organ disease with a diversity of clinical manifestations affecting the heart, skin, joint, lung, and kidneys, and disease flares and times of remission are typically seen in an oscillating pattern in patients with SLE. SLE is characterized by extensive autoantibody production, dysregulation of the immune system, and formation of immune complexes which are not properly cleared. The pathophysiology of the disease is complex and monitoring SLE can be difficult. The aim of this thesis was to investigate the significance of protective molecules and autoantibodies targeting them in a group of well-characterized patients with SLE.

    The pentraxin family is a group of highly conserved pattern recognition molecules with immunomodulatory functions involved in recognition and clearance of pathogens as well as cellular debris and apoptotic cells. The short pentraxin C-reactive protein (CRP) and the long pentraxin pentraxin-3 (PTX3) are members of the family with overlapping functions. CRP is natively pentameric (pCRP) and can undergo irreversible dissociation to its monomeric subunits (mCRP) in certain conditions. These two isoforms of CRP are known to exert contrasting immunologic effects, where mCRP is seen as the more pro-inflammatory isoform. In Paper I of this thesis, we measured these two CRP isoforms in the serum of patients with SLE and found that their ratio in paired samples could differentiate between patients in active disease versus remission. In Paper II we investigated pCRP and mCRP on the surface of extracellular vesicles (EVs) in SLE and discovered an abundance of mCRP-bound EVs in active SLE and in anti-CRP autoantibody positive patients, as well as a higher ratio of mCRP/pCRP-bound EVs in active disease. These findings suggest the mCRP/pCRP ratio as a potential biomarker for monitoring disease activity, and a possible role of mCRP-bound EVs in SLE pathophysiology.

    Autoantibodies targeting CRP as well as PTX3 have been found in SLE. Anti-CRP antibodies are seen to reflect disease activity while anti-PTX3 antibodies are suggested to have a protective role in SLE. Herein, anti-CRP and anti-PTX3 antibodies were measured and the linear binding epitopes of CRP and PTX3 were investigated in Paper III and Paper IV. We found a variety of epitopes scattered across the full sequence of both proteins, and some of them associated with disease activity and clinical variables of importance in SLE. The levels of anti-PTX3 were seen in lower levels among patients with active SLE compared to those with quiescent disease.

    In conclusion, combined assessment of pCRP and mCRP might be useful in monitoring disease activity, and mCRP-bound EVs associated with active disease and anti-CRP antibody positivity. In addition, anti-CRP and anti-PTX3 antibodies target various epitopes with different potential implications in SLE. Further studies are needed to investigate the potential pathophysiological implications of these studies.

    List of papers
    1. Associations of C-reactive protein isoforms with systemic lupus erythematosus phenotypes and disease activity
    Open this publication in new window or tab >>Associations of C-reactive protein isoforms with systemic lupus erythematosus phenotypes and disease activity
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    2022 (English)In: Arthritis Research & Therapy , E-ISSN 1478-6362, Vol. 24, no 1, article id 139Article in journal (Refereed) Published
    Abstract [en]

    Background Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a large production of autoantibodies and deficient clearance of cellular waste. The disease typically oscillates between episodes of elevated disease activity and quiescent disease. C-reactive protein (CRP) is a pentameric acute-phase protein usually reflecting inflammation and tissue damage. However, despite increased inflammation and elevated interleukin-6, the levels of CRP typically remain low or only slightly raised in SLE. Under certain conditions, pentameric CRP (pCRP) can dissociate into its monomeric isoform (mCRP), which mainly has been ascribed pro-inflammatory properties. The present study aims to investigate the potential relationship between pCRP and mCRP, respectively, with disease activity and clinical features of SLE. Methods The levels of pCRP and mCRP were measured, by turbidimetry (high-sensitive) and sandwich enzyme-linked immunosorbent assay (ELISA) respectively, in serum samples from 160 patients with SLE and 30 patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Twenty-two of the SLE cases were selected for analysis at two time-points; quiescent disease and active disease. The two CRP isoforms were evaluated in relation to disease activity and clinical features in the two diseases. Results Levels of pCRP and mCRP were significantly lower in SLE than AAV (p &lt; 0.001) and the ratio of mCRP/pCRP was higher in SLE compared to AAV. The mCRP/pCRP ratio was higher for patients in remission and able to significantly separate between active/quiescent disease in paired, but not in non-paired, samples from patients with SLE. Significant correlations were observed with SLICC/ACR damage index for pCRP levels as well as inversely with the mCRP/pCRP ratio. Lower mCRP levels associated with malar rash. Conclusion As the interrelationship between the two isoforms appear to (a) discriminate between quiescent and active SLE and (b) differ between SLE and AAV, our data indicates that the two CRP isoforms could exert contrasting immunological effects and/or reflect different milieus. Given the biological effects of mCRP, it is possible that altered levels may indicate increased opsonization of immune complexes and apoptotic debris, and thereby prevent their deposition outside the reticuloendothelial system and manifestations such as lupus nephritis and lupus-related skin disease.

    Place, publisher, year, edition, pages
    BMC, 2022
    Keywords
    Acute-phase protein; Inflammation; Biomarker; Complement; Pentraxin; Systemic lupus erythematosus; C-reactive protein; Vasculitis
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-186501 (URN)10.1186/s13075-022-02831-9 (DOI)000810224400001 ()35690780 (PubMedID)
    Note

    Funding Agencies|Linkoping University; Swedish Rheumatism Association; Region Ostergotland (ALF Grants); Gustafsson Foundation; King Gustaf Vs 80-year Anniversary foundation; King Gustaf V and Queen Victorias Freemasons foundation

    Available from: 2022-06-29 Created: 2022-06-29 Last updated: 2025-03-27
    2. Extracellular vesicles opsonized by monomeric C-reactive protein (CRP) are accessible as autoantigens in patients with systemic lupus erythematosus and associate with autoantibodies against CRP
    Open this publication in new window or tab >>Extracellular vesicles opsonized by monomeric C-reactive protein (CRP) are accessible as autoantigens in patients with systemic lupus erythematosus and associate with autoantibodies against CRP
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    2023 (English)In: Journal of Autoimmunity, ISSN 0896-8411, E-ISSN 1095-9157, Vol. 139, article id 103073Article in journal (Refereed) Published
    Abstract [en]

    The pentraxin C-reactive protein (CRP) is a pentameric protein now known to be able to undergo dissociation into a monomeric, modified isoform, referred to as mCRP. In carefully assessing the bioactivities of each isoform, mCRP has strong pro-inflammatory activities while pCRP has mild anti-inflammatory activities. Systemic lupus erythematosus (SLE) is a disease characterized by a vast number of autoantibodies, including anti-CRP autoan-tibodies which have been associated with SLE disease activity and lupus nephritis. The origin of these autoan-tibodies is currently unknown. Extracellular vesicles (EVs) have been implicated in SLE pathogenesis as they can expose nuclear antigens on their outside surface, thereby being a potential adjuvant for the generation of au-toantibodies. Herein, we studied exposure of both pCRP and mCRP on EVs in SLE plasma and the implications of each in disease activity, organ damage and clinical manifestations. We used flow cytometry to detect CRP iso-forms on EV surfaces in 67 well-characterized SLE patients and 60 sex-and age-matched healthy controls. Au-toantibodies against mCRP were measured using ELISA. We found an abundance of both pCRP and mCRP on SLE EVs compared to controls. Furthermore, mCRP+ but not pCRP+ EVs were elevated in patients with active disease and in anti-CRP positive patients. The proportions of mCRP+ EVs were lower in patients with acquired organ damage, especially in patients with lupus nephritis (LN), and displayed an inverse relationship with disease duration in LN and patients with active disease. Speculatively, these data suggest EV-bound mCRP as a relevant factor in SLE pathogenesis, which could contribute to development of anti-CRP autoantibodies by stimulating an immune response.

    Place, publisher, year, edition, pages
    ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2023
    Keywords
    Systemic lupus erythematosus; C-reactive protein; Extracellular vesicles; Anti -CRP antibodies; Immune complexes
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-196781 (URN)10.1016/j.jaut.2023.103073 (DOI)001032975500001 ()37356347 (PubMedID)2-s2.0-85163296022 (Scopus ID)
    Note

    Funding Agencies|Swedish Rheumatism Association [R-939149]; Region Ostergotland (ALF Grants); Gustafsson Foundation; King Gustaf Vs 80-year Anniversary foundation [FAI-2020-0663]; King Gustaf V and Queen Victorias Freemasons foundation [2017-21]

    Available from: 2023-08-23 Created: 2023-08-23 Last updated: 2025-03-27
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  • Public defence: 2025-05-16 09:15 Plank, F-building, LinköpingOrder onlineBuy this publication >>
    Zattarin, Elisa
    Linköping University, Department of Physics, Chemistry and Biology, Biophysics and bioengineering. Linköping University, Faculty of Science & Engineering.
    Multifunctional and Antimicrobial Nanocellulose-based Wound Dressings2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Hard-to-heal wounds cause significant patient suffering and place a heavy burden on healthcare systems, accounting for about 4 % of the entire healthcare budget globally. In hospital settings, up to 40% of beds are occupied by patients with wounds, and substantial resources are allocated to outpatient care. Wounds are highly susceptible to bacterial colonization, which can lead to infection and further delay healing. With the rise of multidrug-resistant bacteria, this challenge has become a global healthcare concern.

    This thesis explores new antimicrobial strategies and techniques to modify nanocellulose wound dressings to enable both detection and treatment of infections in hard-to-heal wounds. Nanocellulose, and in particular bacterial nano-cellulose (BC), is an attractive wound dressing material that provides a moist wound microenvironment and a protective barrier against external pathogens but lacks inherent antimicrobial properties. Antimicrobial peptides (AMPs) have recently gained attention for wound treatment due to their potent antimicrobial effects and low risk of antibiotic resistance.

    This thesis explores the possibility to functionalize BC wound dressings with AMPs, focusing on: i) enhancing AMPs loading, ii) preventing uncontrolled release, and iii) enabling triggered AMPs release to develop stimuli-responsive wound dressings. Initially, the physical adsorption of the AMPs PLNC8 αβ in BC was investigated. However, this approach resulted in low loading efficiency and uncontrolled release. To improve AMPs loading, mesoporous silica nanoparticles (MSNs) were self-assembled in the BC dressings, resulting in a BC-MSN composite with a threefold increase in specific surface area. The nanocomposites retained attractive wound dressing properties and AMPs loading proved to be more efficient, achieving up to a fourfold increase in AMPs concentrations. In a second approach loading of AMPs micelles and AMPs-loaded MSNs in a hyaluronic acid hydrogel that was subsequently grafted to BC was developed. This strategy ensured efficient AMPs loading and high antimicrobial activity while stimulating healing.

    To attain a more precise AMPs release control, a strategy to coat AMPs-loaded MSNs with proteins was developed. Protein capped MSNs retained the AMPs in absence of proteases, while protease-triggered degradation of the capping led to a ~85% AMPs release. Protease activity is typically highly upregulated in infected wounds and the protease responsive AMPs release can thus facilitate efficient infection control. In addition to controlled AMPs delivery, this thesis explores novel AMPs designs. Starting with PLNC8 β, iterations of truncations, amino acid substitutions, and lipidation, lead to the discovery of a new class of sequence-optimized antimicrobial peptides (SOAPs) with broad-spectrum activity and potent antimicrobial action in the micromolar concentration range. To further enhance their efficacy and reduce the required dosage, SOAP peptides were loaded onto self-assembled BC-silver nanoparticle (AgNP) composite dressings, allowing for the simultaneous delivery of AMPs and silver ions.

    Beyond infection treatment, this work also explores the potential of BC-MSN composite materials for wound infection detection. The high surface area of the composite was utilized to immobilize a pH-responsive molecule capable of detecting pH changes in the wound microenvironment indicative of infection. The immediate color change of the dressings in infected wounds could enable early and non-invasive wound status monitoring.

    Overall, the functionalization strategies presented in this thesis provide a highly adaptable platform for development of multifunctional antimicrobial nano-cellulose wound dressings, offering new possibilities for advanced wound care.

    List of papers
    1. Nanocellulose composite wound dressings for real-time pH wound monitoring
    Open this publication in new window or tab >>Nanocellulose composite wound dressings for real-time pH wound monitoring
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    2023 (English)In: Materials Today Bio, ISSN 2590-0064, Vol. 19, article id 100574Article in journal (Refereed) Published
    Abstract [en]

    The skin is the largest organ of the human body. Wounds disrupt the functions of the skin and can have catastrophic consequences for an individual resulting in significant morbidity and mortality. Wound infections are common and can substantially delay healing and can result in non-healing wounds and sepsis. Early diagnosis and treatment of infection reduce risk of complications and support wound healing. Methods for monitoring of wound pH can facilitate early detection of infection. Here we show a novel strategy for integrating pH sensing capabilities in state-of-the-art hydrogel-based wound dressings fabricated from bacterial nanocellulose (BC). A high surface area material was developed by self-assembly of mesoporous silica nanoparticles (MSNs) in BC. By encapsulating a pH-responsive dye in the MSNs, wound dressings for continuous pH sensing with spatiotemporal resolution were developed. The pH responsive BC-based nanocomposites demonstrated excellent wound dressing properties, with respect to conformability, mechanical properties, and water vapor transmission rate. In addition to facilitating rapid colorimetric assessment of wound pH, this strategy for generating functional BC-MSN nanocomposites can be further be adapted for encapsulation and release of bioactive compounds for treatment of hard-to-heal wounds, enabling development of novel wound care materials.

    Place, publisher, year, edition, pages
    Elsevier, 2023
    Keywords
    Bacterial nanocellulose, Wound dressing, pH sensor, Infection, Mesoporous silica nanoparticles
    National Category
    Biomaterials Science
    Identifiers
    urn:nbn:se:liu:diva-192408 (URN)10.1016/j.mtbio.2023.100574 (DOI)000944392500001 ()36852226 (PubMedID)
    Note

    Funding agencies: This work was supported by the Swedish Foundation for Strategic Research (SFF) grant no. FFL15-0026 and framework grant RMX18-0039 (HEALiX), the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU no. 2009–00971), the competence center FunMat-II that is financially supported by Vinnova (grant no. 2016-05156), the Knut and Alice Wallenberg Foundation (grant no. KAW 2016.0231), the Swedish Research Council (VR) (grant no. 2021-04427) and Swedish strategic research program Bio4Energy. Illustrations were created with BioRender.com. We thank S2Medical AB, Linköping, Sweden, for providing BC.

    Available from: 2023-03-15 Created: 2023-03-15 Last updated: 2025-04-14Bibliographically approved
    2. Development of novel broad-spectrum antimicrobial lipopeptides derived from plantaricin NC8 β
    Open this publication in new window or tab >>Development of novel broad-spectrum antimicrobial lipopeptides derived from plantaricin NC8 β
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    2023 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 13, no 1, article id 4104Article in journal (Refereed) Published
    Abstract [en]

    Bacterial resistance towards antibiotics is a major global health issue. Very few novel antimicrobial agents and therapies have been made available for clinical use during the past decades, despite an increasing need. Antimicrobial peptides have been intensely studied, many of which have shown great promise in vitro. We have previously demonstrated that the bacteriocin Plantaricin NC8 αβ (PLNC8 αβ) from Lactobacillus plantarum effectively inhibits Staphylococcus spp., and shows little to no cytotoxicity towards human keratinocytes. However, due to its limitations in inhibiting gram-negative species, the aim of the present study was to identify novel antimicrobial peptidomimetic compounds with an enhanced spectrum of activity, derived from the β peptide of PLNC8 αβ. We have rationally designed and synthesized a small library of lipopeptides with significantly improved antimicrobial activity towards both gram-positive and gram-negative bacteria, including the ESKAPE pathogens. The lipopeptides consist of 16 amino acids with a terminal fatty acid chain and assemble into micelles that effectively inhibit and kill bacteria by permeabilizing their cell membranes. They demonstrate low hemolytic activity and liposome model systems further confirm selectivity for bacterial lipid membranes. The combination of lipopeptides with different antibiotics enhanced the effects in a synergistic or additive manner. Our data suggest that the novel lipopeptides are promising as future antimicrobial agents, however additional experiments using relevant animal models are necessary to further validate their in vivo efficacy.

    Place, publisher, year, edition, pages
    Nature Publishing Group, 2023
    National Category
    Basic Medicine
    Identifiers
    urn:nbn:se:liu:diva-194112 (URN)10.1038/s41598-023-31185-8 (DOI)000988825800016 ()
    Funder
    Swedish Foundation for Strategic Research, RMX18 0039Örebro University
    Note

    Funding agencies: Tis work was supported by the Swedish Foundation for Strategic Research (SSF), RMX18 0039 and the Knowledge Foundation, 20180148.

    Available from: 2023-05-25 Created: 2023-05-25 Last updated: 2025-04-14
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  • Public defence: 2025-05-16 09:30 Ada Lovelace, B-building, LinköpingOrder onlineBuy this publication >>
    Ahmadian, Amirhossein
    Linköping University, Department of Computer and Information Science, The Division of Statistics and Machine Learning. Linköping University, Faculty of Science & Engineering.
    Handling Novel and Out-Of-Distribution Data in Deep Learning: OOD Detection and Shortcut Mitigation2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Advancements in machine learning, and particularly deep learning, have revolutionized the real-world applications of artificial intelligence in recent years. A main property of deep neural models is their ability to learn a task based on a set of examples, that is, the training data. Although the state-of-the-art performance of such models is promising in many tasks, this of-ten holds only as long as the inputs to the model are “sufficiently similar” to the training data. Mathematically, a ubiquitous assumption in machine learning studies is that the test data used for evaluating a model are sampled from the same probability distribution as the training data. It is challenging to approach any problem where this assumption is violated, as it requires handling Out-Of-Distribution (OOD) data, i.e., data points that are systematically different from the training (in-distribution) data. In particular, one might be interested in detecting OOD inputs at test time given an unlabeled training set, which is the main problem explored in this thesis. This type of OOD detection (a.k.a. novelty/anomaly detection) has various applications in discovering unusual events and phenomena as well as improving safety in AI systems. Another challenging problem in deep learning is that a model might rely on certain trivial relations (spurious correlations) existing in training data to solve a task. Such “shortcuts” can bring a high performance on in-distribution data, but they may collapse on more realistic OOD data. It is therefore vital to mitigate the shortcut learning effects in deep models, which is the second topic studied in this thesis.

    A part of the present thesis is concerned with leveraging pretrained deep models for OOD detection on images, without modifying their standard training algorithms. A method is proposed to use invertible (flow-based) generative models based on null hypothesis testing ideas, leading to an OOD detection method that is fast and more reliable than the traditional likelihood-based method. Diffusion (score-based) models are another type of modern generative models used for OOD detection in this thesis, in combination with pretrained deep encoders. Another contribution of the thesis is in leveraging the power of large self-supervised models in fully unsupervised fine-grained OOD detection. It is shown that the simple k-nearest neighbor distance in the representation space of such models results in a reasonable performance but can be boosted substantially through the proposed adjustments, without any model fine-tuning. The local geometry of representations and background (irrelevant) features are considered to this end.

    OOD detection with time series data is another problem studied in this thesis. Specifically, a method is proposed based on Contrastive Predictive Coding (CPC) self-supervised learning, and applied to detect novel categories in human activity data. It is demonstrated, both empirically and through theoretical motivation, that modifying the CPC to use a radial basis function instead of the conventional log-bilinear function is a requirement for reliable and efficient OOD detection. This extension is combined with quantization of representation vectors to achieve better performance.

    This thesis also addresses the problem of learning deep representations (transfer learning) in a situation where a shortcut exists in data. In this problem, a deep model is trained on a shortcut-biased image dataset to solve a self-supervised or supervised classification task. The representations learned by this model are used to train a smaller model on a related but different downstream task, and the adverse effect of the shortcut is verified empirically there. Moreover, a method is proposed to enhance the representation learning in this scenario, based on an auxiliary model trained in an adversarial manner along with the upstream classifier.

    List of papers
    1. Likelihood-free Out-of-Distribution Detection with Invertible Generative Models
    Open this publication in new window or tab >>Likelihood-free Out-of-Distribution Detection with Invertible Generative Models
    2021 (English)In: Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence (IJCAI 2021), International Joint Conferences on Artifical Intelligence (IJCAI) , 2021, p. 2119-2125Conference paper, Published paper (Refereed)
    Abstract [en]

    Likelihood of generative models has been used traditionally as a score to detect atypical (Out-of-Distribution, OOD) inputs. However, several recent studies have found this approach to be highly unreliable, even with invertible generative models, where computing the likelihood is feasible. In this paper, we present a different framework for generative model--based OOD detection that employs the model in constructing a new representation space, instead of using it directly in computing typicality scores, where it is emphasized that the score function should be interpretable as the similarity between the input and training data in the new space. In practice, with a focus on invertible models, we propose to extract low-dimensional features (statistics) based on the model encoder and complexity of input images, and then use a One-Class SVM to score the data. Contrary to recently proposed OOD detection methods for generative models, our method does not require computing likelihood values. Consequently, it is much faster when using invertible models with iteratively approximated likelihood (e.g. iResNet), while it still has a performance competitive with other related methods

    Place, publisher, year, edition, pages
    International Joint Conferences on Artifical Intelligence (IJCAI), 2021
    Series
    Proceedings of the International Joint Conference on Artificial Intelligence, ISSN 1045-0823
    Keywords
    Deep Learning, Anomaly/Outlier Detection, Uncertainty Representations
    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:liu:diva-188936 (URN)10.24963/ijcai.2021/292 (DOI)001202335502027 ()2-s2.0-85125461759 (Scopus ID)9780999241196 (ISBN)
    Conference
    International Joint Conference on Artificial Intelligence (IJCAI), 19-26 August, 2021
    Available from: 2022-10-03 Created: 2022-10-03 Last updated: 2025-04-14Bibliographically approved
    2. Unsupervised Novelty Detection in Pretrained Representation Space with Locally Adapted Likelihood Ratio
    Open this publication in new window or tab >>Unsupervised Novelty Detection in Pretrained Representation Space with Locally Adapted Likelihood Ratio
    2024 (English)In: International Conference on Artificial Intelligence and Statistics 2024, Proceedings of Machine Learning Research, 2024, Vol. 238Conference paper, Published paper (Refereed)
    Abstract [en]

    Detecting novelties given unlabeled examples of normal data is a challenging task in machine learning, particularly when the novel and normal categories are semantically close. Large deep models pretrained on massive datasets can provide a rich representation space in which the simple k-nearest neighbor distance works as a novelty measure. However, as we show in this paper, the basic k-NN method might be insufficient in this context due to ignoring the 'local geometry' of the distribution over representations as well as the impact of irrelevant 'background features'. To address this, we propose a fully unsupervised novelty detection approach that integrates the flexibility of k-NN with a locally adapted scaling of dimensions based on the 'neighbors of nearest neighbor' and computing a 'likelihood ratio' in pretrained (self-supervised) representation spaces. Our experiments with image data show the advantage of this method when off-the-shelf vision transformers (e.g., pretrained by DINO) are used as the feature extractor without any fine-tuning.

    Series
    Proceedings of Machine Learning Research, ISSN 2640-3498
    National Category
    Computer Sciences Computer graphics and computer vision Signal Processing
    Identifiers
    urn:nbn:se:liu:diva-203391 (URN)001221034002024 ()
    Conference
    27th International Conference on Artificial Intelligence and Statistics (AISTATS), Valencia, SPAIN, MAY 02-04, 2024
    Available from: 2024-05-08 Created: 2024-05-08 Last updated: 2025-04-14
    3. Enhancing Representation Learning with Deep Classifiers in Presence of Shortcut
    Open this publication in new window or tab >>Enhancing Representation Learning with Deep Classifiers in Presence of Shortcut
    2023 (English)In: Proceedings of IEEE ICASSP 2023, 2023Conference paper, Published paper (Refereed)
    Abstract [en]

    A deep neural classifier trained on an upstream task can be leveraged to boost the performance of another classifier in a related downstream task through the representations learned in hidden layers. However, presence of shortcuts (easy-to-learn features) in the upstream task can considerably impair the versatility of intermediate representations and, in turn, the downstream performance. In this paper, we propose a method to improve the representations learned by deep neural image classifiers in spite of a shortcut in upstream data. In our method, the upstream classification objective is augmented with a type of adversarial training where an auxiliary network, so called lens, fools the classifier by exploiting the shortcut in reconstructing images. Empirical comparisons in self-supervised and transfer learning problems with three shortcut-biased datasets suggest the advantages of our method in terms of downstream performance and/or training time.

    Keywords
    Deep Representation Learning, Shortcut Learning, Transfer Learning, Adversarial Methods, Computer Vision
    National Category
    Computer Sciences Computer graphics and computer vision
    Identifiers
    urn:nbn:se:liu:diva-198763 (URN)10.1109/ICASSP49357.2023.10096346 (DOI)
    Conference
    2023 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
    Available from: 2023-10-26 Created: 2023-10-26 Last updated: 2025-04-14
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  • Public defence: 2025-05-16 13:00 Hugo Theorellsalen, building 440, LinköpingOrder onlineBuy this publication >>
    Dohlmar, Frida
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Diagnostics and Specialist Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Medical radiation physics.
    Inverse Brachytherapy Treatment Planning: Validation and Development2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Manual treatment planning in brachytherapy is time-consuming and highly dependent on the skill of the planner. To be able to perform the planning efficiently and to give the patient the best possible brachytherapy treatment, new methods need to be developed. New methods need to be validated carefully. This thesis aims to validate and advance high dose-rate brachytherapy planning methods.

    Current treatment planning methods were studied and used for comparison. An in-house-developed post-adjustment tool was validated for prostate brachytherapy, with the goal to reduce high-dose volumes while preserving target coverage and avoiding increased organ-at-risk doses. Additionally, an inverse treatment planning method for cervical brachytherapy was developed using clinically available optimisation tools.

    Validation was performed using established and novel dose metrics, supported by oncologist’s observer studies. Statistical methods from diagnostic radiology were adapted for comprehensive analysis of the observer studies—marking their first application in radiation therapy.

    Results confirmed that the post-adjustment tool effectively reduced high-dose volumes in prostate brachytherapy, while preserving the target coverage and the dose to the organs-at-risk. The inverse cervical brachytherapy method was successfully implemented in two clinical systems, with treatment plans scored equal to manual plans in the observer study. These two new methods could make it possible to use inverse methods for cervical brachytherapy, and to perform inverse prostate brachytherapy without manual adjustments. This will make the treatment planning process faster and less dependent on the skill of the treatment planner.

    List of papers
    1. An audit of high dose-rate prostate brachytherapy treatment planning at six Swedish clinics
    Open this publication in new window or tab >>An audit of high dose-rate prostate brachytherapy treatment planning at six Swedish clinics
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    2021 (English)In: Journal of Contemporary Brachytherapy, ISSN 1689-832X, E-ISSN 2081-2841, Vol. 13, no 1, p. 59-71Article in journal (Refereed) Published
    Abstract [en]

    Purpose: High dose-rate prostate brachytherapy has been implemented in Sweden in the late 1980s and early 1990s in six clinics using the same schedule: 20 Gy in two fractions combined with 50 Gy in 25 fractions with external beam radiation therapy. Thirty years have passed and during these years, various aspects of the treatment process have developed, such as ultrasound-guided imaging and treatment planning system. An audit was conducted, including a questionnaire and treatment planning, which aimed to gather knowledge about treatment planning methods in Swedish clinics. Material and methods: A questionnaire and a treatment planning case (non-anatomical images) were sent to six Swedish clinics, in which high-dose-rate prostate brachytherapy is performed. Treatment plans were compared using dosimetric indices and equivalent 2 Gy doses (EQD(2)). Treatment planning system report was used to compare dwell positions and dwell times. Results: For all the clinics, the planning aim for the target was 10.0 Gy, but the volume to receive the dose differed from 95% to 100%. Dose constraints for organs at risk varied with up to 2 Gy. The dose to 90% of target volume ranged from 10.0 Gy to 11.1 Gy, equivalent to 26.0 Gy EQD(2) and 31.3 Gy EQD(2), respectively. Dose non-homogeneity ratio differed from 0.18 to 0.32 for clinical target volume (CTV) in treatment plans and conformity index ranged from 0.52 to 0.59 for CTV. Conclusions: Dose constraints for the organs at risk are showing a larger variation than that reflected in compared treatments plans. In all treatment plans in our audit, at least 10 Gy was administered giving a total treatment of 102 Gy EQD(2), which is in the upper part of the prescription doses published in the GEC/ESTRO recommendations.

    Place, publisher, year, edition, pages
    TERMEDIA PUBLISHING HOUSE LTD, 2021
    Keywords
    brachytherapy; audit; dosimetric indices
    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:liu:diva-174413 (URN)10.5114/jcb.2021.103588 (DOI)000620114000010 ()
    Note

    Funding Agencies|Radium-hemmets forskningsfonder (Stockholm, Sweden) [161042]; Swedish Cancer SocietySwedish Cancer Society [CAN 2018/622, CAN 2017/1029]

    Available from: 2021-03-21 Created: 2021-03-21 Last updated: 2025-04-09
    2. Validation of automated post-adjustments of HDR prostate brachytherapy treatment plans by quantitative measures and oncologist observer study
    Open this publication in new window or tab >>Validation of automated post-adjustments of HDR prostate brachytherapy treatment plans by quantitative measures and oncologist observer study
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    2023 (English)In: Brachytherapy, ISSN 1538-4721, E-ISSN 1873-1449, Vol. 22, no 3, p. 407-415Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: The aim was to evaluate a postprocessing optimization algorithms ability to improve the spatial properties of a clinical treatment plan while preserving the target coverage and the dose to the organs at risk. The goal was to obtain a more homogenous treatment plan, minimizing the need for manual adjustments after inverse treatment planning. MATERIALS AND METHODS: The study included 25 previously treated prostate cancer pa-tients. The treatment plans were evaluated on dose-volume histogram parameters established clin-ical and quantitative measures of the high dose volumes. The volumes of the four largest hot spots were compared and complemented with a human observer study with visual grading by eight oncologists. Statistical analysis was done using ordinal logistic regression. Weighted kappa and Fleiss kappa were used to evaluate intra-and interobserver reliability. RESULTS: The quantitative analysis showed that there was no change in planning target volume (PTV) coverage and dose to the rectum. There were significant improvements for the adjusted treatment plan in: V150% and V200% for PTV, dose to urethra, conformal index, and dose nonhomogeneity ratio. The three largest hot spots for the adjusted treatment plan were significantly smaller compared to the clinical treatment plan. The observers preferred the adjusted treatment plan in 132 cases and the clinical in 83 cases. The observers preferred the adjusted treatment plan on homogeneity and organs at risk but preferred the clinical plan on PTV coverage. CONCLUSIONS: Quantitative analysis showed that the postadjustment optimization tool could improve the spatial properties of the treatment plans while maintaining the target coverage. (c) 2022 The Authors. Published by Elsevier Inc. on behalf of American Brachytherapy Society. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

    Place, publisher, year, edition, pages
    ELSEVIER SCIENCE INC, 2023
    Keywords
    Prostate brachytherapy; Automated treatment planning; Inverse treatment planning; Dosimetric indices; Ob-server study
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:liu:diva-195322 (URN)10.1016/j.brachy.2022.12.008 (DOI)001000924700001 ()36739222 (PubMedID)
    Available from: 2023-06-20 Created: 2023-06-20 Last updated: 2025-04-09
    3. Dwell time shaping in inverse treatment planning for cervical brachytherapy
    Open this publication in new window or tab >>Dwell time shaping in inverse treatment planning for cervical brachytherapy
    Show others...
    2024 (English)In: Physics and Imaging in Radiation Oncology, E-ISSN 2405-6316, Vol. 32, article id 100672Article in journal (Refereed) Published
    Abstract [en]

    Background and purpose: Manual treatment planning for cervical brachytherapy is a challenging task; therefore, we investigated a method for inverse treatment planning using pseudo-structures to control the dwell distribution. Our hypothesis was that this method could produce treatment plans with a pear-shaped dose distribution and a high central dose, that comply with clinical constraints. Materials and methods: Data from 16 previously treated patients were used to compare three treatment planning methods: i) manual, ii) straightforward inverse, and iii) inverse with pseudo-structures. The treatment plans were compared using dose-volume histogram parameters and by analysing the dwell times, and the distribution of total reference air-kerma (TRAK) in the different parts of the applicator. Methods were evaluated in one treatment planning system and verified in a second treatment planning system. Results: The median dose to 90 % of the clinical tumor volume was 7.6 Gy, 7.8 Gy and 8.1 Gy for manual, pseudostructure and straightforward methods respectively. Distribution of TRAK for the different parts of the applicator for the three methods (manual, pseudo-structures, and straightforward), with combined intracavitary and interstitial treatments, were for vaginal part 39 %, 33 % and 15 %, for intra-uterine part 47 %, 50 % and 47 % and for interstitial part 13 %, 17 % and 38 % respectively. The results were similar in the second treatment planning system. Conclusion: The developed pseudo-structures worked as intended in shaping the dwell time distribution and in meeting the clinical constraints for both investigated treatment planning systems.

    Place, publisher, year, edition, pages
    ELSEVIER, 2024
    Keywords
    Brachytherapy; Treatment planning; Cervical cancer; Optimisation; Inverse treatment planning
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:liu:diva-210187 (URN)10.1016/j.phro.2024.100672 (DOI)001357660500001 ()39620172 (PubMedID)2-s2.0-85208681861 (Scopus ID)
    Note

    Funding Agencies|Swedish Research Council [VR-NT 2019-05416, VR-NT 2023-04181]

    Available from: 2024-12-03 Created: 2024-12-03 Last updated: 2025-04-09
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  • Public defence: 2025-05-16 13:00 Key1, Keyhuset, LinköpingOrder onlineBuy this publication >>
    Malmström, Louise
    Linköping University, Department of Behavioural Sciences and Learning, Education and Adult Learning. Linköping University, Faculty of Educational Sciences.
    Lärande för politiskt ledarskap: Kunskapers värde utifrån partiinterna logiker för socialdemokratiska ledare2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aim of this thesis is to contribute knowledge about how different skills are valued in relation to political leadership based on internal party logics. More specifically, the study focuses on social democratic leaders, how internal party leadership training for them is designed, and what significant learning such training contributes to this group.

    The thesis is structured as a compilation thesis. The research questions are primarily addressed in four articles. The first and second articles highlight the knowledge that social democratic members of parliament and social democratic municipal political leaders consider valuable in relation to their assignments. The second and third articles provide an overview of how intra-party leadership training is organised for these two groups and what skills are central to such training. The third and fourth articles focus on the learning outcomes of the intra-party leadership training for this group and how their leader-ship practices change after the training.

    The empirical data of the thesis is mainly derived from interviews, ethnographic participant observations, and questionnaire responses. Based on Bourdieu's conceptual framework, internal party logics are illustrated regarding what knowledge is recognised as valuable and what can function as inclusive or exclusive in the various stages of political leadership.

    Overall, the thesis contributes knowledge about what is valued in order to be elected, to fulfil one's mission successfully, and to be re-elected. The discrepancy between the different sets of knowledge valued at different stages is discussed. Additionally, the role of intra-party leadership training as a leveller of these skills, its role in calibrating leaders' ideology and behaviour, and its importance in building a popular methodological bank and a supportive network are highlighted.

    List of papers
    1. Den folkligt bildade politikern: Akademiska kunskaper och det symboliska kapitalets logik inom den socialdemokratiska riksdagsgruppen i Sverige
    Open this publication in new window or tab >>Den folkligt bildade politikern: Akademiska kunskaper och det symboliska kapitalets logik inom den socialdemokratiska riksdagsgruppen i Sverige
    2015 (Swedish)In: Nordisk kulturpolitisk tidskrift, ISSN 1403-3216, E-ISSN 2000-8325, Vol. 18, no 2, p. 233-249Article in journal (Refereed) Published
    Abstract [en]

    Globally speaking, parliamentarians tend to be more highly educated than their average constituent. In some countries, such as Great Britain and France, there is also a clear link between political power and some certain educational institutions, such as Cambridge and Oxford, which have become important roads to a successful political career. The Swedish political elite differs from this pattern. Even though Swedish parliamentarians generally have a higher education than the average Swede, having an academic education has not been a necessity for a successful political career. This is particularly evident in the Social Democratic Party, which is Sweden’s largest party. Non-academic educational pathways have been of great importance. Historically, popular education, particularly certain «folk high schools», have served as an alternative educational portal for politicians. Is this still the case? What forms of education and knowledge are currently important portals for entering the political elite in Sweden? This paper explores these questions, using interviews with Social Democratic MPs and data from Statistics Sweden on MPs' educational background. Bourdieu's concept of symbolic capital is used to analyze how different skills and educational experiences confer value within the Social Democratic Party. The results show that there are a number of different types of knowledge and experience that are considered of great value. The value of academic knowledge exhibits a great deal of ambivalence. In terms of exchange value (e.g. academic degrees), academic knowledge is conferred low value and is often downplayed narratively. At the same time, however, in terms of use value, academic knowledge is acknowledged to have considerable utility as academic education is seen to facilitate the reading of political documents that forms a large part of MPs' daily lives. The results also suggest that non-formal education still appears to be a highly valued educational pathway to political power in Sweden.

    Place, publisher, year, edition, pages
    Högskolan i Borås, 2015
    Keywords
    higher education, popular education, parliamentarians, symbolic capital, the social democratic party, sweden, political elites, folkbildning, riksdagsledamöter, symboliskt kapital, socialdemokraterna, sverige, politiska eliter, högre utbildning
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-122709 (URN)
    Projects
    Utbildningsvägar till makten
    Funder
    Swedish Research Council
    Available from: 2015-11-17 Created: 2015-11-17 Last updated: 2025-04-16Bibliographically approved
    2. Vad bör en kommunpolitisk ledare kunna?: Kunskaper som symboliskt kapital bland socialdemokratiska lokalpolitiker
    Open this publication in new window or tab >>Vad bör en kommunpolitisk ledare kunna?: Kunskaper som symboliskt kapital bland socialdemokratiska lokalpolitiker
    2021 (Swedish)In: Utbildning och Demokrati, ISSN 1102-6472, E-ISSN 2001-7316, Vol. 30, no 3, p. 33-56Article in journal (Refereed) Published
    Abstract [en]

    In Sweden, there are no specific academic paths leading to a political career and many local elected leaders develop the knowledge they need in other ways. The aim of this article is to find out which kinds of knowledge they value and how they develop these. Using the results from questionnaires and interviews with local social democratic leaders, four groups of knowledge that constitute symbolic capital in the field of Swedish local politics are identified: ideological, communicative, organisational and academic. Some types of knowledge are communicated openly, whilst others are hard to pinpoint and even contradictory, which tends to exclude some members. Both long-term members and newer members find attending party training useful to develop the knowledge they need to get elected and fulfil their political assignment.

    Keywords
    party-political education, local elected leaders, symbolic capital, social democrats, labour movement, political skills
    National Category
    Social Sciences Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-188527 (URN)10.48059/uod.v30i3.1580 (DOI)
    Funder
    Swedish Research Council
    Available from: 2022-09-15 Created: 2022-09-15 Last updated: 2025-04-16
    3. Shaping reflective political leaders
    Open this publication in new window or tab >>Shaping reflective political leaders
    2024 (English)In: International Journal of Lifelong Education, ISSN 0260-1370, E-ISSN 1464-519XArticle in journal (Refereed) Epub ahead of print
    Abstract [en]

    Unlike many other countries, in Sweden there are more significant paths to political leadership than the university degree. Most Swedish political parties offer leadership training programmes that include practical and ideological content and several have a design rooted in the popular education movement. This article explores how party political training for leaders happens in practice, using data from interviews, surveys, text files and ethnographic field notes. Using reflection and ideology as theoretical concepts, the study shows how reflection is used for different aims, and how it can shape participants ideologically. Ideology, in terms of describing what is good, is communicated from the top down in these courses in a general way. In terms of showing what is possible and desirable to either legitimise or challenge, these programmes leave that open to negotiation among the participants, which implies a confidence in their competence by virtue of being elected. Allowing different interpretations risks undermining the party's ideological core; however, since popular education methods are not negotiated, participants are required to reflect deliberately and listen to each others views on the issues under discussion. This can be understood as a safety line as it most likely leads to self-sanitation from the party's perspective.

    Place, publisher, year, edition, pages
    ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2024
    Keywords
    Leadership training; popular education; labour movement
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-208654 (URN)10.1080/02601370.2024.2412593 (DOI)001331814900001 ()
    Available from: 2024-10-21 Created: 2024-10-21 Last updated: 2025-04-16
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  • Public defence: 2025-05-19 14:00 K4, building Kåkenhus and online via Zoom (contact madelene.topfer@liu.se)., NorrköpingOrder onlineBuy this publication >>
    Menshikova, Anastasia
    Linköping University, Department of Management and Engineering, The Institute for Analytical Sociology, IAS. Linköping University, Faculty of Arts and Sciences.
    Cultural change: Studying social interdependencies in public discourse with computational text analysis2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis uses computational text analysis to advance the sociological understanding of how culture, as reflected in public discourse, comes to change. Drawing upon theoretical foundations of analytical sociology and cultural sociology, I view public discourse as a collective phenomenon shaped by an interplay of individual-level dynamics and interdependencies between different societal spheres that contribute to public discussions. Computational text analysis enables analyzing the interdependencies and individual-level dynamics underlying shifts in public discourse and advances the sociological explanation of cultural change. Using the empirical setting of the Swedish immigration discourse, this work explicates mechanisms and conditions shaping changes in public discourse in the wake of unexpected events and political crises. This thesis contributes to existing work with new research designs for analyzing individual-level and macro-level cultural changes by further integrating computational text analysis into sociological research.

    Essay I theorizes and tests the role of different individual-level mechanisms in generating aggregate-level shifts in social media discourses following disruptive events. I analyze how changes in (1) the way individuals talk about immigration (within-individual change) and (2) the composition of individuals who participate in online discussions (compositional change) contribute to the aggregate-level shifts in the Swedish online immigration debate following a series of Jihadist terrorist attacks in the 2010s in Sweden and in Europe. I quantify how shifts in the salience of culture, security, and economy in immigration discourse before and after attacks are jointly shaped by the two mechanisms. This study underscores the necessity of individual-level text data in distinguishing between mechanisms that can produce similar shifts in aggregate measures of discourse.

    Essay II systematically analyzes the effects of terrorist attacks on public opinion towards im-migration across Europe and evaluates the moderating role of national-level media attention preceding the attacks. I examine this idea empirically by analyzing the impact of 38 jihadist terrorist attacks on public opinion on immigration in 19 European countries in 2013-19, using a multi-site natural experiment approach. In this paper, I combine survey data from the ESS with a multilingual corpus of media coverage from the largest European national media outlets. Contrary to the expectations, even under conditions of heightened media attention on immigration, I find no significant effects of terrorism. I demonstrate the importance of combining digital trace textual data from social media with traditional data sources for sociological inquiry.

    Essay III studies long-term cultural change and compares the similarity between cultural meanings in the national newspapers and on social media over more than a decade. I compare changes in collective meanings of immigration — the macro-level dynamics within different spheres of public discourse — in the Swedish national newspapers and at the largest Swedish online forum, Flashback. I test whether the European ‘refugee crisis’ brought the two spheres of public discourse closer together or drove them further apart. This paper offers a novel methodological approach to drawing a plausible and comprehensive comparison between discourses generated by vastly different groups of actors using seeded topic modeling. The results support the convergence story, meaning networks in the newspapers and online became more aligned during 2015–16 European ‘refugee crisis.’

    Essay IV examines the relationship between everyday interests and political preferences within Sweden’s multi-party context, thus analyzing a broader social context surrounding politically engaged Swedes who discuss politics and immigration online. Using data from Swedish Twitter from 2010-2020 and utilizing mixed-membership clustering to discover coherent groups of everyday interests in unstructured social media data, we analyze how non-partisan everyday interests align with specific political parties and the left-right political scale. The results demonstrate that the fragmentation of everyday interests in a multi-party political system aligns with political ideologies rather than partisan identities. Despite the observed polarization, certain interests transcend political divides, offering opportunities for dialogue across ideological lines.

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  • Public defence: 2025-05-20 13:00 Key 1, Key-building, LinköpingOrder onlineBuy this publication >>
    Lidström, Tina
    Linköping University, Department of Behavioural Sciences and Learning, Education and Sociology. Linköping University, Faculty of Arts and Sciences.
    Re-shaping Teacher Professionalism Through Discursive Interaction: On Tensions Around the Idea of Teacher Assistants in Educational Reform2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Under the acceleration of educational reforms and “fast policy” different ideas about teachers and what “good” education involves are at the centre of educational and political debates. Ideas of what a teacher is and “ought to be” tie into questions of purpose in teacher professionalism and its inherent values. This thesis deals with how different actors shape and give differing meanings to values around teacher professionalism. The overarching aim is to gain a deeper understanding of different actors’ shaping of teacher professionalism under the tensions around the idea of teacher assistants at and across national and transnational education policy levels, and the local compulsory school level. In so doing, the thesis delves into the dilemmas, tensions, and possibilities that emerge through discursive interaction among actors, shaped by different social and institutional conditions.

    Drawing on a theoretical and methodological framework of discursive institutionalism and curriculum theory, a deeper understanding of the re-shaping of teacher professionalism through discursive interaction is gained. A central concept based in this framework is “discursive space” (i.e., a “room for manoeuvre”) where actors negotiate between different values around what teacher professionalism “ought to be” across institutional levels, but with differing contextual conditions. The study is based on both interviews with teachers and teacher assistants as local actors at the compulsory school level in Sweden, and policy documents at national and transnational levels. Central policy actors that are included at the national level are the Ministry of Education and Research and the National Agency for Education, and the Organisation for Economic Cooperation and Development (OECD) at the transnational level.

    The study shows how actors embark on discursive interaction in a negotiated and conditioned discursive space. Although actors’ discursive interaction involves diverging values around teacher professionalism it also centres these values around teachers’ “core responsibility” for teaching and teaching as “core focus” in what may be conceptualised as “teachification”. However, this “teachification” points to a reductionist and oversimplified understanding of teaching and teacher professionalism in education policy, where the complexities of the compulsory school context are not taken into consideration. This means that the re-shaping of teacher professionalism includes a shift in teachers’ professional responsibility, where moral and social values are reduced and values around standardisation and accountability simultaneously increase. This re-shaping also involves the shaping of a conditioned teacher assistant professionalism, which includes teacher assistants’ implicit professional responsibility within and surrounding teaching. In the discursive space, dilemmas emerge in relation to teachers’ “sharing” of questions of purpose in professional responsibility. Dilemmas also emerge in a “struggle for time”, where temporal conditions are articulated as crucial to motivating questions of purpose in teachers’ professional responsibility. In parallel, multiple temporalities around teacher professionalism and teaching create tensions when policy actors’ and local actors’ temporalities diverge.

    The thesis points to a re-conceptualisation of teacher professionalism involving change in how teacher professionalism is governed and understood towards transnational “soft” governance. This change involves “teachification” where specific sorts of time, i.e., to “increase time” and a certain temporalisation, i.e., to shape by measuring and quantifying come to the fore. In the discursive space, further tensions emerge between teachers’ values, ideals and beliefs and the reductionist understanding of teaching and teacher professionalism with an increased push towards accountability regarding teachers’ professional responsibility for teaching.

    More broadly, the idea of teacher assistants is integrated in complex policy constructions at the national level that are pushed by transnational discourses and a “crisis”- narrative around students’ learning outcomes driven by the OECD. Tensions emerge when a national context “translates” seemingly simple ideas in a complex education system that bring with them certain normative values around what teacher professionalism “ought to be”, pointing towards de-professionalism rather than re-professionalism. These tensions reflect national variations regarding cultural traditions around professionalism, different administrative traditions as well as diverging levels of bureaucratic control and political demands on education.

    Taken together, the thesis raises issues related to transnationally oriented curriculum research regarding the constitutive and performative role of ideas and discourses in turning to actors in a landscape of accelerated educational reforms. The thesis sheds light on a struggle around how discursive practices are both reinforced and changed in the discursive space. The thesis also sheds light on how discourses with their embedded ideas, shape diverging institutional and social conditions for actors’ discursive interaction across arenas and levels where discursive powers are at play. This implies that ideational structures reflect and animate certain normative beliefs, values and norms in a globalised institutional context of education. In turn, these structures illuminate how schools, as institutional settings, and, thus, local actors are conditioned by and through educational reforms.

    List of papers
    1. The policy idea of ‘the teacher assistant’: Construction and legitimation through a discursive institutionalist lens
    Open this publication in new window or tab >>The policy idea of ‘the teacher assistant’: Construction and legitimation through a discursive institutionalist lens
    2024 (English)In: European Educational Research Journal, E-ISSN 1474-9041, Vol. 23, no 1, p. 108-124Article in journal (Refereed) Published
    Abstract [en]

    Transnational policy discourses shape teacher professionalism through discursive patterns in policy initiatives from the global policy actor, OECD. The policy idea of ‘the teacher assistant’ has emerged through discourses on teacher professionalism, spurring ambiguities regarding what the policy idea is and ought to be in Sweden. The aim of this article is to critically examine the construction and legitimation of the policy idea of ‘the teacher assistant’, in relation to teachers and the educational institution, through the lens of discursive institutionalism and strands in Curriculum Theory. The focus is a critical understanding of the interplay between ideas, discourses, actors and institutional context. The analysis of policy documents shows how the policy idea is constructed and legitimised through actors’ coordinative and communicative discourses at the national level, influenced by the OECD at the transnational level. The policy idea is intertwined with ideas and discourses on teachers’ professional development through a national professional programme and institutional conditions for goal attainment in schools. Tensions emerge regarding underlying assumptions about teacher quality, highlighting ideas of what teachers are and ought to be, within comprehensive reform strategies. Tensions entail emerging ideas of standardisation and differentiation and ambiguities regarding the policy idea of ‘the teacher assistant’.

    Place, publisher, year, edition, pages
    Sage Publications, 2024
    Keywords
    Teacher professionalism, teacher assistant, discursive institutionalism, teacher quality, OECD, education policy
    National Category
    Educational Sciences
    Identifiers
    urn:nbn:se:liu:diva-188923 (URN)10.1177/14749041221123636 (DOI)000857700500001 ()
    Available from: 2022-10-03 Created: 2022-10-03 Last updated: 2025-04-16
    2. Teacher assistants’ values in a discursive space: emerging change and re-negotiation of teacher professionalism in Sweden
    Open this publication in new window or tab >>Teacher assistants’ values in a discursive space: emerging change and re-negotiation of teacher professionalism in Sweden
    2024 (English)In: Nordic Journal of Studies in Educational Policy, ISSN 2002-0317Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    In the Nordic context, transnational discourses influence recontextualisation of ideas and discourses, and thus, how local actors negotiate around values imbued with ideas and discourses. In Sweden, the idea of teacher assistants has been prompted – through policy discourses on teacher professionalism – under imperatives of reducing teachers’ workload and increasing professional responsibility and accountability. The aim of this article is to explore teacher assistants’ values regarding roles and responsibilities in relation to teachers and education in light of policy discourses on teacher professionalism. Drawing on discursive institutionalism and curriculum theory, the concept of ‘discursive space’ is utilized to explore values in an institutional context. Based on twelve interviews with teacher assistants in compulsory schools, the analysis shows how a reductionist notion of teaching gives rise to dilemmas around being teachers’ ‘alter ego’ when values around teaching as ‘core’ are prioritized. Dilemmas around local pluralization emerge when teacher assistants are viewed as a ‘solution’ to a plethora of issues. Challenges emerge in the context of ambiguity around teacher assistants’ orientation towards teaching or processes ‘surrounding’ teaching. The analysis illustrates conditioned values highlighting dilemmas and challenges, but also possibilities for discursive action. Altogether, a re-negotiation of teacher professionalism emerges in the discursive space.

    Place, publisher, year, edition, pages
    Informa UK Limited, 2024
    Keywords
    Teacher professionalism, ideas, teacher assistant, discursive space, discursive institutionalism
    National Category
    Pedagogy
    Identifiers
    urn:nbn:se:liu:diva-205530 (URN)10.1080/20020317.2024.2370989 (DOI)
    Available from: 2024-06-26 Created: 2024-06-26 Last updated: 2025-04-16
    3. Teachers’ values in a space of change: The idea of teacher assistants as re-negotiation of teacher professionalism
    Open this publication in new window or tab >>Teachers’ values in a space of change: The idea of teacher assistants as re-negotiation of teacher professionalism
    2024 (English)In: Education Inquiry, E-ISSN 2000-4508Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    Teacher professionalism has long been subject to contestation as embedded with certain ideas, norms and values. Transnational discourses on teacher professionalism have spurred the recontextualisation of the idea of teacher assistants in Swedish educational reform. Policy imperatives around increasing teachers’ professional responsibility and accountability have raised issues regarding what values around teacher professionalism ought to be prioritised. The aim of this article is to explore teachers’ values regarding professional responsibility in the compulsory school context based on the interaction with teacher assistants and in light of policy discourses on teacher professionalism. The concept of “discursive space” is utilised to explore juxtaposed values within the local and across national and transnational levels. This concept is based in a combination of discursive institutionalism and curriculum theory with an actor-centred approach around ideas and discourses in an institutional context. The analysis shows dilemmas around holistic aspects and fragmentation regarding professional responsibility, but also, possibilities when “sharing” responsibilities with teacher assistants. Dilemmas emerge around questions on purpose and temporal struggles. Dilemmas emerge regarding professional responsibility against accountability purposes and result-orientation. Re-negotiation of teacher professionalism is spurred by the idea of teacher assistants, and surrounding discourses, creating dilemmas for teachers in the negotiated discursive space.

    Place, publisher, year, edition, pages
    Informa UK Limited, 2024
    Keywords
    Teacher professionalism, ideas, teacher assistant, discursive space, discursive institutionalism
    National Category
    Pedagogical Work
    Identifiers
    urn:nbn:se:liu:diva-207290 (URN)10.1080/20004508.2024.2396169 (DOI)001302358700001 ()
    Available from: 2024-09-03 Created: 2024-09-03 Last updated: 2025-04-16
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  • Public defence: 2025-05-21 13:15 ACAS, A-building, LinköpingOrder onlineBuy this publication >>
    Abu Sa'a, Ehab
    Linköping University, Department of Management and Engineering, Project Innovations and Entrepreneurship. Linköping University, Faculty of Science & Engineering.
    Leveraging Co-created Knowledge in Multi-sector University-Industry Collaboration2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In an era of accelerating technological complexity and societal transformation, multi-sector university–industry collaborations (UICs) have become vital arenas for co-creating and exchanging knowledge across institutional and industrial boundaries. Yet, industrial organizations often struggle to harness the full potential of such collaborations, particularly when it comes to effectively sharing, recognizing, and leveraging knowledge among diverse actors from different industries. Much of the existing research remains centered on the academic perspective of UIC, typically portraying universities as the primary source of knowledge. Such a framing tends to overlook the industrial perspective, especially the potential of industry-to-industry knowledge sharing and the perspective of firms with limited UIC experience. Furthermore, previous research has largely focused on dyadic university-industry ties and immediate project-level outcomes, with less attention to the structural, organizational, and social dynamics that support knowledge exchange across industries, and how this knowledge is later integrated within firms and diffused to the broader knowledge ecosystem.

    This thesis addresses these gaps by exploring how collaboration-level structures and firm-level actions influence the sharing and leveraging of knowledge within and beyond multi-sector UICs. It is based on a compilation of five empirical research articles grounded in case studies of multi-sector UIC initiatives in Sweden and Denmark, involving diverse industries, academic actors, and intermediaries. Data was collected mainly through interviews and observations. The analysis covers collaboration structures and practices, boundary-spanning roles, industrial engagement strategies, and actions related to internal knowledge dissemination.

    The thesis makes three key contributions. First, it identifies collaboration-level structures, both formal and informal, that support cross-industry knowledge sharing and ecosystem shaping. Second, it highlights industrial-level actions that enable deep internal knowledge integration, with attention to experience, engagement, and organizational readiness. Third, it offers a framework of pathways and antecedents to leveraging knowledge in multi-sector UICs, emphasizing the interplay of structures, social capital, and industrial engagement. These insights provide practical implications for industrial organizations, UIC managers, and policymakers aiming to foster impactful, inclusive, and sustainable collaborations.

    List of papers
    1. Unpacking social capital in University–Industry Collaborations: Pathways to cross-industry knowledge sharing
    Open this publication in new window or tab >>Unpacking social capital in University–Industry Collaborations: Pathways to cross-industry knowledge sharing
    2025 (English)In: Technovation, ISSN 0166-4972, E-ISSN 1879-2383, Vol. 140, article id 103160Article in journal (Refereed) Published
    Abstract [en]

    This study investigates the role of University–Industry Collaboration (UIC) in enabling cross-industry knowledge sharing, focusing on the implications of structural social capital within these collaborations. Through a multiple case study involving three distinct UIC structures, we explore how the nature of these collaborations, whether research-focused or networking-focused, influences cross-industry knowledge sharing. Our findings reveal that research-focused UIC, characterized by formal and structured interactions, primarily leverages cognitive social capital to abstract and disseminate knowledge across industries. Conversely, networking-focused UIC, which operates through informal and less-structured channels, relies mainly on relational social capital to foster direct, trust-based knowledge sharing between industries. We identify key enablers and distinctions in these UIC structures, illustrating how they shape cross-industry knowledge sharing. Specifically, we propose a conceptual model, highlighting the mediating role of social capital dimensions and the moderating effects of interest and funding. This model offers new insights into the relationship between structural social capital and cross-industry knowledge sharing in UIC. From a managerial perspective, our study suggests that whether firms engaged in UIC can leverage UIC structures for cross-industry knowledge sharing largely comes down to their own strategical development and management of social capital. From a policy perspective, our study suggests that augmenting already existing policy toward cross-regional knowledge sharing by considering aspects of networking-focused UIC and cross-industrial knowledge sharing, could leverage gains from UIC.

    Place, publisher, year, edition, pages
    Elsevier, 2025
    Keywords
    Cross-industry knowledge sharing; Innovation management; Innovation policy; Social capital; University–industry collaboration
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:liu:diva-210953 (URN)10.1016/j.technovation.2024.103160 (DOI)001397726200001 ()2-s2.0-85213205934 (Scopus ID)
    Note

    Funding Agencies|Erik Johnsson's Foundation

    Available from: 2025-01-15 Created: 2025-01-15 Last updated: 2025-04-16Bibliographically approved
    2. Guests or Collaborators? Exploring Industrial Engagement in University-Industry Collaborations
    Open this publication in new window or tab >>Guests or Collaborators? Exploring Industrial Engagement in University-Industry Collaborations
    2024 (English)Conference paper, Oral presentation with published abstract (Refereed)
    National Category
    Other Mechanical Engineering Business Administration
    Identifiers
    urn:nbn:se:liu:diva-205630 (URN)
    Conference
    R&D management conference, Stockholm
    Available from: 2024-06-27 Created: 2024-06-27 Last updated: 2025-04-16
    3. Exploring enablers of internal knowledge dissemination for boundary-spanning industrial PhD students
    Open this publication in new window or tab >>Exploring enablers of internal knowledge dissemination for boundary-spanning industrial PhD students
    2024 (English)In: Creativity and Innovation Management, ISSN 0963-1690, E-ISSN 1467-8691, Vol. 33, no 3, p. 530-550Article in journal (Refereed) Published
    Abstract [en]

    Industrial PhD students, affiliating to industrial firms and academic institutions, hold unique boundary-spanning positions as they engage in knowledge co-creation through university–industry collaboration (UIC). Despite much research on knowledge transfer processes and boundary spanners in inter-organizational contexts, firms who engage in UIC remain uncertain about how to reap the benefits of co-creating knowledge through industrial PhD projects. This paper investigates the enablers of knowledge dissemination for PhD students in industrial firms. Based on a qualitative case study in Sweden, our study identifies enablers and mechanisms related to individual and organizational actions in the internal knowledge dissemination process. Based on the findings, the paper presents a model that distinguishes between surface and deep knowledge dissemination and elaborates on the symbiotic nature of enablers, with middle management mediating between the individual and organizational levels. The paper enhances research on knowledge dissemination in UIC by specifically addressing industrial PhD students' dissemination of co-created knowledge. The findings inform organizations in managing their expectations, making more informed decisions and improving dissemination conditions for boundary-spanning industrial PhD students in UIC.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2024
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:liu:diva-188900 (URN)10.1111/caim.12596 (DOI)001176886600001 ()2-s2.0-85186862104 (Scopus ID)
    Note

    Funding Agencies|Erik Johnsson's Foundation

    Available from: 2022-09-30 Created: 2022-09-30 Last updated: 2025-04-16Bibliographically approved
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  • Public defence: 2025-05-22 09:00 Belladonna, LinköpingOrder onlineBuy this publication >>
    Kjölhede, Anders
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    On Aspects of Outcomes of Gender Affirming Surgery in Individuals Assigned Female at Birth with Gender Dysphoria2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Gender dysphoria (GD) is a condition in which an individual identifies with a gender different from the one assigned at birth, which causes distress. The number of treatment-seeking individuals with GD is increasing. The exact proportion of individuals with GD is difficult to estimate and is therefore not available. However, numbers of up to 75 per 100,000 have been reported. Gender-affirming treatment for individuals with GD mainly includes gender-affirming hormone therapy and gender-affirming surgery (GAS), and needs to be individualized according to the wishes and goals of the patient. For individuals with GD assigned female at birth (AFAB), testosterone in different preparations constitutes the hormone therapy. GAS is often divided into chest surgery and genital GAS (gGAS). For the AFAB individual with GD, the most commonly performed procedures include subcutaneous mastectomy (SCM), hysterectomy with bilateral salpingo-oophorectomy, neophallus construction and vaginectomy.

    A neophallus can be achieved through two main methods: metoidioplasty and phalloplasty. These techniques differ fundamentally in both the resulting neophallus, and the surgical techniques and tissues involved. The metoidioplasty utilizes the testosterone-induced hypertrophied clitoris to create a small penis, while phalloplasty is a flap-based procedure that can be shaped to resemble a cisgendered (congruent birth and identified gender) man's penis.

    Although scientific studies are becoming more plentiful, with improving levels of evidence, outcomes of these procedures are not well established. The aim of this thesis was to investigate less-researched outcomes to contribute to the growing body of evidence on GAS for AFAB individuals with GD. Specifically, the number of surgical procedures required for a complete outcome of metoidioplasty or groin flap phalloplasty, as well as the impact of vaginectomy, SCM, and neophallus construction on various aspects of health-related quality of life (HRQoL).

    Material and methods: This thesis is based on four substudies. The substudies were single-center studies conducted at the Department of Plastic Surgery, Hand Surgery, and Burns at Linköping University Hospital. The GAS procedures investigated were neophallus construction with either groin flap phalloplasty or metoidioplasty, vaginectomy, and SCM. Demographic data, the number of surgical procedures, and complications related to each of the procedures were retrospectively obtained from patients’ local hospital electronic medical records.

    In three of the substudies, condition-specific HRQoL was recorded either longitudinally, in a prospective manner, or as a cross-sectional measurement, using questionnaires. A minimum of one year had passed before postoperative assessment was undertaken for longitudinal measures. The Pelvic Floor Distress Inventory, Short Form Version (PFDI-20), was used to assess changes in symptoms related to pelvic floor dysfunction after vaginectomy. The Self-Esteem and Relationship Questionnaire (SEAR) and Sexual Quality of Life - Male Version (SQoL-M) were used to quantify sexual quality of life in patients who had undergone neophallus construction and those awaiting the procedure. Measurements of HRQoL related to SCM were assessed using a novel self-constructed (by our research group) questionnaire.

    Results: A total of 217 AFAB individuals with GD were included across the four substudies with 23 individuals included in more than one substudy. Follow-up times were variable, with a median of 7.3 years (1 - 13), 7.5 years (1 - 13), 1 year, and 3.5 years (1 - 5) for groin flap phalloplasty, metoidioplasty, vaginectomy and SCM, respectively. Complications occurred frequently, in 46% after groin flap phalloplasty, in 34% after metoidioplasty, and in 43% after vaginectomy, but less frequently after SCM (11%), although most of them were of minor severity. Additional stages of surgery were also common, with a median 5 (2 - 14) surgical procedures for groin flap phalloplasty, 2 (1 - 10) for metoidioplasty, 1 (1 - 2) for vaginectomy, and 2 (1 - 4) for SCM.

    Vaginectomy had no impact on PFDI-20 score (preoperative score 24, postoperative score 35 (p = 0.10)). In the substudy on SQoL related to neophallus construction, we found no statistically significant difference in SEAR scores between the waiting list group and the postoperative group, 71 and 75, respectively (p = 0.38). The same was true for SQoL-M, where the waiting list group scored 55 and the postoperative group scored 73 (p = 0.25). 24% of patients with groin flap phalloplasty and 24% with metoidioplasty reported using their neophallus for penetrative intercourse. Patients undergoing SCM reported a statistically significant improvement in all items on the self-constructed HRQoL questionnaire except for perceived nipple-areola complex sensation, which saw a significant deterioration (p < 0.001).

    Conclusion: GAS constitutes an important part of the treatment of individuals with GD. Although advances have been made, both in methods of surgery and in research of these methods, high quality studies are lacking. Outcomes of GAS are complex, however, the results of this thesis have helped shed light on outcomes, and, improved the growing body of evidence on common GAS procedures for AFAB individuals with GD.

    List of papers
    1. Metoidioplasty and groin flap phalloplasty as two surgical methods for the creation of a neophallus in female-to-male gender-confirming surgery: A retrospective study comprising 123 operated patients
    Open this publication in new window or tab >>Metoidioplasty and groin flap phalloplasty as two surgical methods for the creation of a neophallus in female-to-male gender-confirming surgery: A retrospective study comprising 123 operated patients
    2019 (English)In: JPRAS Open, E-ISSN 2352-5878, Vol. 22, p. 1-8Article in journal (Refereed) Published
    Abstract [en]

    In gender-confirming surgery of the female-to-male gender dysphoric patient, there is currently no ideal method for the creation of a neophallus. Historically, in our clinic, groin flap phalloplasty (GFP) has been the dominating method, but during the last 20 years, it has gradually been replaced with metoidioplasty (MP). The aim of this study was to investigate whether this change of method has influenced factors such as the frequency of complications and the number of operations needed to complete the reconstruction of the neophallus.

    Place, publisher, year, edition, pages
    Elsevier, 2019
    Keywords
    Female-to-male; Gender dysphoria; Gender-confirming surgery; Groin flap phalloplasty; Metoidioplasty
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-164705 (URN)10.1016/j.jpra.2019.07.003 (DOI)32158891 (PubMedID)
    Available from: 2020-03-31 Created: 2020-03-31 Last updated: 2025-04-07
    2. A Study on Symptoms of Pelvic Floor Dysfunction in Assigned Female at Birth Patients Diagnosed with Gender Dysphoria Undergoing Vaginectomy
    Open this publication in new window or tab >>A Study on Symptoms of Pelvic Floor Dysfunction in Assigned Female at Birth Patients Diagnosed with Gender Dysphoria Undergoing Vaginectomy
    2024 (English)In: Plastic and Reconstructive Surgery - Global Open, E-ISSN 2169-7574, Vol. 12, no 7, article id e5950Article in journal (Refereed) Published
    Abstract [en]

    Background: A person diagnosed with gender dysphoria who was assigned female at birth (AFAB) may request a vaginectomy as part of gender-affirming treatment. The aim of this study was to investigate the impact of vaginectomy on symptoms of pelvic floor dysfunction (PFD). Methods: This is a cohort study on patient-reported symptoms of PFD in patients who were AFAB, diagnosed with gender dysphoria, and undergoing vaginectomy in a single surgical center. Patients responded to a questionnaire preoperatively and 1 year postoperatively. The questionnaire consisted of 33 questions, including a modified short-form version of the Pelvic Floor Distress Inventory (PFDI-20). Results: Twenty-three consecutive patients were included in the study and 20 patients (87%) completed the 1-year follow-up. The preoperative median PFDI-20 score was 24 (0-114) compared with 32 (0-168) at the 1-year follow-up (P = 0.07). Patients who had previously undergone neophallus construction with a metoidioplasty (n = 15) had no significant change between the preoperative and the 1-year postoperative PFDI-20 score [median 17.5 (0-114) and 27.5 (0-145) (P = 0.65), respectively]; whereas those with a groin flap phalloplasty (n = 5) had a significant increase in reported symptoms [median 37 (10-95) and 124 (45-168), respectively (P = 0.04)]. Conclusions: Overall, vaginectomy could be performed without any major impact on symptoms of PFD. However, this seemed to be true mainly for patients with previous metoidioplasty, whereas patients with previous groin flap phalloplasty reported worsening of symptoms.

    Place, publisher, year, edition, pages
    LIPPINCOTT WILLIAMS & WILKINS, 2024
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-206451 (URN)10.1097/GOX.0000000000005950 (DOI)001259920200005 ()38957715 (PubMedID)
    Note

    Funding Agencies|ALF grants from Region Ostergotland

    Available from: 2024-08-20 Created: 2024-08-20 Last updated: 2025-04-15
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  • Public defence: 2025-05-23 09:00 Berzeliussalen, LinköpingOrder onlineBuy this publication >>
    Brüggemann, Cecilia
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Children's and Women's Health. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Gynaecology and Obstetrics in Linköping.
    Oxytocin Augmentation of Labour: Impact of Timing, Cumulative Dose and Plasma Concentrations on Perinatal Outcomes, and Women’s Experiences of Decision-making2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Introduction: Oxytocin augmentation is a common intervention in modern labour care, used to reduce labour dystocia and caesarean section rates. New definitions on the start of active labour, as well as a lack of knowledge on the association between cumulative dose, plasma concentrations, and labour outcomes warranted this research, along with the need to understand women’s experiences of decision-making regarding labour interventions.

    Methods: Studies I and II were cohort studies, associating the cervical dilation at the time of oxytocin initiation and the cumulative oxytocin dose in primiparous women experiencing spontaneous onset of labour, with adverse labour and postpartum outcomes using logistic regression methods. In Study III, plasma oxytocin concentrations were serially measured during ongoing oxytocin augmentation and thereafter analysed using tandem mass spectrometry (MS/MS). The median and maximum oxytocin concentrations were examined in relation to labour outcomes, and the correlation between the maximum concentration and the number and total duration of contractions was calculated. In Study IV, women with spontaneous onset of labour were interviewed on their experiences of decision-making regarding labour interventions. The transcribed interviews were analysed using reflexive thematic analysis.

    Results: Oxytocin augmentation initiated ≤5cm cervical dilation was more often associated with caesarean section (p<0.001) and a negative birth experience (p 0.006), but logistic regression indicated no increased risk of operative births (1.28 (aOR 0.78-2.08)). A high cumulative oxytocin dose (>75th percentile, >4370mU/437mL) increased the risk of postpartum haemorrhage (2.77 (aOR 1.77-4.37)), an overdistended bladder postpartum (2.17 (aOR 1.08-4.38)) and a negative birth experience (1.65 (aOR 1.11-2.46)). The median and maximum plasma oxytocin concentration during labour with oxytocin infusion was higher among women with an operative birth (caesarean section or vacuum extraction) compared to women with a spontaneous vaginal birth (p 0.03 and p 0.027), without any differences in remaining outcomes. The experiences of decision-making regarding labour interventions were highly individual. The themes To be a crew member, Choosing to be a passenger and To be left behind were developed, reflecting the varying experiences of labouring women.

    Conclusions: According to new recommendations on the start of active labour, early initiation of oxytocin should be avoided, if possible, as it may have negative consequences on labour outcomes and women’s birth experiences. Initiating oxytocin infusion in early labour should perhaps be viewed as a form of labour induction and discussed accordingly among healthcare professionals and with women in labour. Healthcare professionals should also be ready to prevent and manage postpartum haemorrhages when high cumulative oxytocin doses have been administered and should use active measures to detect and avoid an overdistended bladder in the early postpartum period. The plasma oxytocin concentration in labour is highly individual, but women with an operative birth had higher concentrations than women with spontaneous vaginal births. The association needs further research to better understand the effects. Labouring women’s need for inclusion in decision-making varies depending on individual, situational and contextual factors; however, most women want to receive information on their labour process and the welfare of their child. By adopting a women-centred approach, offering choice and control in labour and birth, and empowering women through sharing evidence-based information and shared decision-making, women’s satisfaction with decision-making during childbirth might increase, thereby also improving their overall birth experience.

    List of papers
    1. Labor dystocia and oxytocin augmentation before or after six centimeters cervical dilatation, in nulliparous women with spontaneous labor, in relation to mode of birth
    Open this publication in new window or tab >>Labor dystocia and oxytocin augmentation before or after six centimeters cervical dilatation, in nulliparous women with spontaneous labor, in relation to mode of birth
    2022 (English)In: BMC Pregnancy and Childbirth, E-ISSN 1471-2393, Vol. 22, no 1, article id 408Article in journal (Refereed) Published
    Abstract [en]

    Background The effects of diagnosing and treating labor dystocia with oxytocin infusion at different cervical dilatations have not been fully evaluated. Therefore, we aimed to examine whether cervical dilatation at diagnosis of dystocia and initiation of oxytocin infusion at different stages of cervical dilatation were associated with mode of birth, obstetric complications and womens birthing experience. Methods A retrospective cohort study, including 588 nulliparous term women with spontaneous onset of labor and dystocia requiring oxytocin augmentation. The study population was divided into three groups according to cervical dilatation at diagnosis of dystocia and initiation of oxytocin-infusion (&lt;= 5 cm, 6-10 cm, fully dilated) with mode of birth as the primary outcome. Secondary outcomes were obstetrical and neonatal complications and women s experience of childbirth. Statistical comparison between groups using Chi-square and ANOVA was performed. The risk of operative birth (cesarean section and instrumental birth) was assessed using binary logistic regression with suitable adjustments (maternal age, body mass index and risk assessment on admission to the labor ward). Results The cesarean section rate differed between the groups (p &lt; 0.001); 12% in the &lt;= 5 cm group, 6% in the 6-10 cm group and 0% in the fully dilated group. There was no increased risk for operative birth in the &lt;= 5 cm group compared to the 6-10 cm group, adjusted OR 1.28 95%CI (0.78-2.08). The fully dilated group had a decreased risk of operative birth (adjusted OR 0.48 95%CI (0.27-0.85). The rate of a negative birthing experience was high in all groups (28.5%, 19% and 18%) but was only increased among women in the &lt;= 5 cm group compared with the 6-10 cm group, adjusted OR 1.76 95%CI (1.05-2.95). Conclusions Although no difference in the risk of operative birth was found between the &lt;= 5 cm and 6-10 cm cervical dilatation-groups, the cesarean section rate was highest in women with dystocia requiring oxytocin augmentation at &lt;= 5 cm cervical dilatation. This might indicate that oxytocin augmentation before 6 cm cervical dilatation could be contra-productive in preventing cesarean sections. Further, the increased risk of negative birth experience in the &lt;= 5 cm group should be kept in mind to improve labor care.

    Place, publisher, year, edition, pages
    BMC, 2022
    Keywords
    Oxytocin augmentation; Active labor; Labor dystocia; Cesarean section; Birth experience
    National Category
    Gynaecology, Obstetrics and Reproductive Medicine
    Identifiers
    urn:nbn:se:liu:diva-185389 (URN)10.1186/s12884-022-04710-2 (DOI)000795561200002 ()35562716 (PubMedID)
    Note

    Funding Agencies|Linkoping University; ALF (Avtal om Lakarutbildning och forskning) grants; Region Ostergotland [RO-938175]

    Available from: 2022-06-01 Created: 2022-06-01 Last updated: 2025-04-08
    2. Cumulative oxytocin dose in spontaneous labour: Adverse postpartum outcomes, childbirth experience, and breastfeeding
    Open this publication in new window or tab >>Cumulative oxytocin dose in spontaneous labour: Adverse postpartum outcomes, childbirth experience, and breastfeeding
    Show others...
    2024 (English)In: European Journal of Obstetrics, Gynecology, and Reproductive Biology, ISSN 0301-2115, E-ISSN 1872-7654, Vol. 295, p. 98-103Article in journal (Refereed) Published
    Abstract [en]

    Objectives: This study aimed to determine the association between the total cumulative oxytocin dose during labour and adverse postpartum outcomes, childbirth experience and breastfeeding in term primiparous women with spontaneous onset of labour.

    Study design: A prospective observational multicentre study, including 1395 women with spontaneous labour, in seven hospitals in Southeast Sweden. Multivariable logistic regression (Crude Odds Ratios (OR) and adjusted OR (aOR) for relevant confounders) was used to analyze the association between oxytocin dose and postpartum outcomes. The exposure was the cumulative oxytocin dose during labour, classified in percentiles (<25th, 25-75th, >75th). The outcomes were occurrence of obstetric anal sphincter injury, postpartum haemorrhage (blood loss > 1000 ml), Apgar score < 7 at five minutes, umbilical cord arterial pH, postpartum bladder overdistension, exclusive breastfeeding at one week and three months, and the woman’s perceived birth experience.

    Results: Women receiving high amounts (>75th percentile, >4370 mU) of oxytocin infusion during labour had an increased risk of postpartum haemorrhage (OR 2.73 (1.78–4.19)), an overdistended bladder (OR 2.19 (1.11–4.31)), an infant with an Apgar score < 7 at five minutes (OR 2.89 (1.27–6.57)), a negative birth experience (OR 1.83 (1.25–2.69)), and a decreased chance of exclusive breastfeeding at one week (OR 0.63 (0.41–0.96)). After adjusting for confounders, all outcomes remained statistically significant except risk of low Apgar score and chance of exclusive breastfeeding.

    Conclusion: In women with high cumulative oxytocin dose during labour prompt, and prophylactic administration of uterotonics after delivery of the placenta should be considered to reduce the risk of postpartum haemorrhage. The risk for bladder overdistension can be reduced by implementing routines for observation for signs of bladder filling in the early postpartum period, as well as routine use of bladder scans post micturition to assess for successful bladder emptying. As women’s birth experience have a major impact on their future mental health, should be routinely assessed postpartum, and support should be offered to women with negative experiences.

    Keywords
    Oxytocin, Postpartum haemorrhage, Overdistended bladder, Apgar score, Childbirth experience, Breastfeeding
    National Category
    Childbirth and Maternity care
    Identifiers
    urn:nbn:se:liu:diva-212876 (URN)10.1016/j.ejogrb.2024.01.040 (DOI)
    Available from: 2025-04-08 Created: 2025-04-08 Last updated: 2025-04-08Bibliographically approved
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  • Public defence: 2025-05-23 09:15 E324, Schrödinger, F-building, LinköpingOrder onlineBuy this publication >>
    Gjøen, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    From Wild to Tame: Domestication of the social brain in Red Junglefowl selected for tameness2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Domestication has led to profound changes in animal behaviour, physiology, and brain morphology. This phenomenon is known as the domestication syndrome. One of the main early drivers for these phenotypic changes is hypothesised to be selection for tameness, i.e. reduced fear of humans and that this trait is heritable. Previous studies on domestication in animals have shown that selection for tameness not only changes inter-specific behaviour, as shown towards humans, but also intra-specific behaviour. This thesis examines how selection for tameness in Red Junglefowl (Gallus gallus) influences social interactions and cerebellar traits, shedding light on the mechanism underlying domestication-related changes. Paper I, II, and IV, focus on how social behaviour in chickens has been shaped by domestication, with domesticated breeds often displaying different social strategies compared to their wild ancestor. To investigate whether selection for tameness alone can drive these changes (paper I), we studied Red Junglefowl lines selected for either high (HF) or low (LF) fear of humans over multiple generations. In a semi-natural setting, we separated HF from LF and made groups consisting of two males and two females. LF birds exhibited more social conflicts and increased male crowing, while HF birds spent more time in proximity and engaged in more non-aggressive social pecking. These differences reflects behavioural distinctions found between wild Red junglefowl and domesticated laying hens, supporting the hypothesis that domestication-related social changes can arise as a side effect of tameness. In addition to changes in conspecific interactions, domesticated chickens exhibit reduced fearfulness and stress responses compared to their wild counterparts (paper II). Behavioural testing in a risk-taking scenario of domesticated White Leghorns (Gallus gallus domesticus) and parental Red junglefowl chicks confirmed that junglefowl were more fearful but also more exploratory. Importantly, social partners helped buffer fear responses in both breeds, with a stronger effect in Red Junglefowl. This suggests that domestication has not only reduced overall fear but also modified the role of social support in managing stress. To investigate the effect of a social buffer further, we gave adult chickens the choice of a known vs unknown social buffer (paper III). Four gradient groups of domestication were tested: White leghorn (WL), the parentals of unselected Red Junglefowl (RJF), low-fear Red Junglefowl (LF), high-fear Red Junglefowl (HF). The birds were tested one by one, in an arena, where they could freely investigate the area, but on each side, there were a couple of same sex birds, one with known birds, and one with unknown birds. We found that LF birds engaged in more non-aggressive social exploration and emitted more food calls; behaviours more commonly associated with domesticated chickens. While unselected RJF males showed increased interest in unfamiliar birds and displayed more agonistic behaviours, whereas this pattern was not mirrored in the HF and LF lines, suggesting that selection for tameness and fearfulness alters social coping. Notably, LF males showed similarities to domesticated White Leghorns, further supporting the idea that tameness selection contributes to shifts in social behaviour. Surprisingly, the WL females showed more agonistic behaviour, mostly towards strange birds, which could be explained by increased motivation to feed and consequently resource defence. The cerebellum, a key brain region in motor coordination and complex cognitive functions, has by different degrees, been shown to be affected by domestication in several species. While domesticated chickens have smaller relative brain size than their wild ancestors, their cerebellum has been relatively enlarged. To explore whether this pattern could be attributed to tameness selection, we examined brain morphology in HF and LF Red Junglefowl (paper III). LF birds exhibited reduced relative brain mass, particularly in the non-cerebellar brain regions, aligning with patterns observed in dully domesticated breeds. HF birds had higher neuronal density in the cerebellum, suggesting that while overall cerebellar size is increased in domesticated-like birds, it does not affect the number of neurons in the cerebellum. Hence, the reason for conserving the cerebellum size, is not more neurons. Thus, to map out the reason for the increased relative cerebellum size, different cerebellar behavioural tests assessing motor coordination, balance and social navigation, were conducted (paper V). There was no significant difference in coordination or balance between HF and LF chicks, but HF birds completed an obstacle course more quickly, possible due to increased social motivation. LF birds exhibited more reorientation pauses, which may reflect higher exploratory tendencies rather than deficits in movement control. Although the HF birds had shorter latency in an obstacle course, there was no significant difference in a rotarod test, which indicates that HF does not necessarily have superior motor skills.  In a Y-maze test assessing social preferences, HF birds showed preference for a non-aggressive rooster, indicating a possible link between fearfulness and risk-taking behaviour and social orientation, whereas this was not observed in the LF birds. The findings suggest that selection for tameness alone can drive significant changes in social behaviour, mirroring domestication effects seen in the modern domesticated chickens. These changes include increased social conflict, altered social exploration patterns, and a shift in social attraction. While LF birds have relatively larger cerebellum, this does not necessarily enhance coordination but may influence social processing, highlighting the complex relationship between tameness, behaviour, and brain morphology.

    List of papers
    1. Selection for Reduced Fear of Humans Changes Intra-Specific Social Behavior in Red Junglefowl - Implications for Chicken Domestication
    Open this publication in new window or tab >>Selection for Reduced Fear of Humans Changes Intra-Specific Social Behavior in Red Junglefowl - Implications for Chicken Domestication
    2022 (English)In: Genes, E-ISSN 2073-4425, Vol. 13, no 1, article id 43Article in journal (Refereed) Published
    Abstract [en]

    The domestic fowl has a different social behavior compared to their ancestor, the red junglefowl. To examine whether selection for tameness has affected their intra-specific social behavior, 32 red junglefowl from two selection lines, one selected for increased tameness and one selected for a high fear of humans for ten generations, were kept in a group of two females and two males each and were observed in a semi-natural undisturbed enclosure. Birds selected for a low fear of humans had more social conflict, and the males from this selection crowed more and were more often observed in low social proximity to others. The high-fear birds spent more time close together with the rest of the group and performed more social, non-aggressive pecking. These results are consistent with known differences between ancestral red junglefowl and domesticated laying hens. Our results show that intra-specific social behavior has been affected as a side-effect of selection for increased tameness. This may have interesting implications for the emergence of the domestication syndrome in chickens.

    Place, publisher, year, edition, pages
    MDPI, 2022
    Keywords
    aggression; tameness; fowl
    National Category
    Endocrinology and Diabetes
    Identifiers
    urn:nbn:se:liu:diva-182933 (URN)10.3390/genes13010043 (DOI)000749524100001 ()35052386 (PubMedID)
    Available from: 2022-02-17 Created: 2022-02-17 Last updated: 2025-04-14
    2. Domestication and social environment modulate fear responses in young chickens
    Open this publication in new window or tab >>Domestication and social environment modulate fear responses in young chickens
    2023 (English)In: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 210, article id 104906Article in journal (Refereed) Published
    Abstract [en]

    Domesticated species differ from their wild ancestors in a mosaic of traits. Classical domestication theories agree that reactivity to fear and stress is one of the main traits affected. Domesticated species are expected to be less fear and stress prone to than their wild counterparts. To test this hypothesis, we compared the behavioural responses of White Leghorn (WL) chicks to their wild counterparts, Red Junglefowl (RJF) chicks in risk-taking situations. In order to obtain food, the chicks faced an unknown and potentially harmful object at the presence or absence of a social partner. We found that according to our predictions, RJF were more stressed and fearful of the object than the WL. Still, RJF were more explorative than WL. Additionally, the presence of a social partner reduced the fear response in both, but had a stronger effect on RJF. Finally, WL were more food orientated than the RJF. Our results confirmed classical domestication hypotheses of downregulation of the stress system and importance of the social partner in domesticated farm chicken.

    Place, publisher, year, edition, pages
    ELSEVIER, 2023
    Keywords
    Chicken; Domestication; Red junglefowl; Risk-taking; Social buffer; Social support; Stress response
    National Category
    Behavioral Sciences Biology
    Identifiers
    urn:nbn:se:liu:diva-196806 (URN)10.1016/j.beproc.2023.104906 (DOI)001029994800001 ()37311492 (PubMedID)
    Note

    Funding Agencies|Austrian Science Fund (FWF) [W1262-B29]; Swedish Research Council [2019-04869]

    Available from: 2023-08-23 Created: 2023-08-23 Last updated: 2025-04-14
    3. Selection for Reduced Fear of Humans Changes Brain and Cerebellum Size in Red Junglefowl in Line with Effects of Chicken Domestication
    Open this publication in new window or tab >>Selection for Reduced Fear of Humans Changes Brain and Cerebellum Size in Red Junglefowl in Line with Effects of Chicken Domestication
    2023 (English)In: Brain Sciences, E-ISSN 2076-3425, Vol. 13, no 7, article id 988Article in journal (Refereed) Published
    Abstract [en]

    A central part of the domestication syndrome is a reduction in relative brain size. In chickens, it has previously been shown that domesticated birds have smaller relative brain mass, but larger relative mass of cerebellum, compared to their ancestors, the Red Junglefowl. It has been suggested that tameness may drive the domestication syndrome, so we examined the relationship between brain characteristics and tameness in 31 Red Junglefowl from lines divergently selected during ten generations for tameness. Our focus was on the whole brain, cerebellum, and the remainder of the brain. We used the isotropic fractionator technique to estimate the total number of cells in the cerebellum and differentiate between neurons and non-neuronal cells. We stained the cell nuclei with DAPI and performed cell counting using a fluorescence microscope. NeuN immunostaining was used to identify neurons. The absolute and relative masses of the brains and their regions were determined through weighing. Our analysis revealed that birds selected for low fear of humans (LF) had smaller relative brain mass compared to those selected for high fear of humans (HF). Sex had a significant impact only on the absolute size of the cerebellum, not its relative size. These findings support the notion that selection for increased tameness leads to an enlargement of the relative size of cerebellum in chickens consistent with comparisons of domesticated and ancestral chickens. Surprisingly, the HF birds had a higher density of neurons in the cerebellum compared to the LF line, despite having a smaller cerebellum overall. These findings highlight the intricate relationship between brain structure and behavior in the context of domestication.

    Place, publisher, year, edition, pages
    MDPI, 2023
    Keywords
    domestication; chicken; cerebellum
    National Category
    Neurosciences
    Identifiers
    urn:nbn:se:liu:diva-196719 (URN)10.3390/brainsci13070988 (DOI)001035057500001 ()37508920 (PubMedID)
    Available from: 2023-08-21 Created: 2023-08-21 Last updated: 2025-04-14
    4. Social preferences in chickens-effects of domestication and tameness
    Open this publication in new window or tab >>Social preferences in chickens-effects of domestication and tameness
    2024 (English)In: FRONTIERS IN ANIMAL SCIENCE, ISSN 2673-6225, Vol. 5, article id 1487688Article in journal (Refereed) Published
    Abstract [en]

    It has been suggested that evolution of domesticated phenotypes may have evolved as a result of correlated selection responses to reduced fear, a prominent feature in early domestication. To investigate whether domestication changes in social preferences can be attributed to increased tameness, we studied two lines of Red Junglefowl, ancestors of domesticated chickens, bidirectionally selected during 12 generations for high (HF) or low (LF) fear of humans and compared the differences between these lines to those between unselected Red Junglefowl (RJF) and domesticated White Leghorn egg layers (WL). One bird at a time was observed on its own for 12 min in an arena with one adjacent pen behind netting on each side. One of the adjacent pens contained familiar birds, and the other contained unfamiliar birds. Towards the end of the observation period, a sudden stressful stimulus was displayed, and we compared the reactions of the breeds to this as well. Male RJF spent more time close to the unfamiliar birds than WL, and performed more agonistic behaviour, but this was not mirrored in the selected birds. For females, it was WL that performed the most agonistic behaviour. Both LF and WL males showed more non-agonistic social exploration than HF and RJF respectively. Male LF and WL emitted more food calls than HF and RJF respectively. We conclude that several differences between RJF and WL were mirrored in the selection lines, with LF behaving more like domesticated WL. This is in line with the hypothesis that selection for tameness may have driven domestication related changes in social behaviour against conspecifics.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2024
    Keywords
    domestication; Red Junglefowl (Gallus gallus); social preference; chickens; tameness; social behaviour; White Leghorn
    National Category
    Behavioral Sciences Biology
    Identifiers
    urn:nbn:se:liu:diva-210701 (URN)10.3389/fanim.2024.1487688 (DOI)001386214700001 ()2-s2.0-85213518316 (Scopus ID)
    Note

    Funding Agencies|Vetenskapsrdet10.13039/501100004359

    Available from: 2025-01-09 Created: 2025-01-09 Last updated: 2025-04-14
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  • Public defence: 2025-05-23 13:00 Belladonna, building 511, LinköpingOrder onlineBuy this publication >>
    Strand, Liam
    Linköping University, Department of Health, Medicine and Caring Sciences, Division of Society and Health. Linköping University, Faculty of Medicine and Health Sciences.
    Withdrawing and Withholding Treatments: Normative and Psychological Challenges in Healthcare Priority Setting2025Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    When medical treatments are not deemed cost-effective, given considerations of e.g., needs and severity, and therefore denied reimbursement, the treatment is commonly withheld from all future patients. However, should the treatment also be withdrawn from patients who have gained early access to it? Previous normative analyses and clinical guidelines suggest that treatments should be equally rationed by both withdrawing and withholding, but empirical studies and policy practices indicate that withholding is more acceptable than withdrawing. It has been suggested that psychological difficulties associated with withdrawing cause this discrepancy, but this remains a hypothesis rather than an experimentally tested explanation.

    The overall aim of the thesis is to explore ethical and psychological aspects of withdrawing treatments in relation to cost-effectiveness, given that withholding is justified. In addition, there is an ambition to formulate ethically justified reimbursement recommendations that account for psychological factors in human judgement and decision-making. The specific research questions are:

    • What are physicians’ and patient organisation representatives’ experiences and perceptions of withdrawing and withholding treatments in rationing situations due to relative scarcity? (Paper I).
    • To what extent do people express an ethical difference between withdrawing and withholding treatments in reimbursement decisions?(Papers II + III).
    • How do different possibly morally relevant circumstances shape support for rationing by withdrawing and withholding? (Papers II + III).
    • What could be a balanced and justified approach to withdrawing and withholding treatments in healthcare priority setting? (Paper IV).

    In Paper I, an interview study was conducted with physicians and patient organisation representatives. In Papers II and III, two experiments tested differences in acceptance of rationing treatments by withdrawing and withholding. In addition, Paper II presents the importance of decision level (policy or bedside), while Paper III presents the importance of different potentially morally relevant circumstances previously identified in Paper I. Paper IV presents a normative analysis, using a reflective equilibrium process, to formulate balanced and justified recommendations on how to withdraw and withhold treatments in reimbursement decisions.

    Paper I showed nuanced perceptions of withdrawing and withholding treatments. In some respects, the two rationing types were deemed ethically equivalent, while in other respects, they were considered ethically inequivalent. Paper II found that 18% of participants accepted withdrawing treatments at the policy level, compared to 29% acceptance for withholding treatments at the policy level and 25% acceptance for withdrawing treatments at the bedside level. Paper III found no general difference in acceptance between withdrawing and withholding treatments. However, differences emerged when analysing specific circumstances, where withholding was viewed as more problematic than withdrawing in four out of eleven circumstances. Across Papers II and III, the overall support for rationing was low. Paper IV analysed the ethical acceptability of withdrawing treatments, given that withholding is acceptable, as well as the ethical acceptability of providing patients with early access to treatments financed by the healthcare system. It is suggested that withdrawing treatments is ethically acceptable, but when patients are granted early access, a practice where physicians inform patients that the treatment will be withdrawn if it does not get reimbursed is required.

    The main conclusions of the thesis can be summarised as follows:

    • In some respects, treatment withdrawal is deemed as ethically equivalent to withholding, while in other aspects, it is deemed as ethically more problematic (Paper I)
    • When presented with a detailed vignette of the rationing situation, people express withdrawing to be less acceptable than withholding (Paper II). However, when presented with short and concise statements, no general difference is perceived (Paper III).
    • Withdrawing is deemed more acceptable at the bedside level than at the policy level (Paper II). However, different circumstances can render withholding equally, and sometimes even more, unacceptable than withdrawing (Paper III).
    • An ethically balanced and justified approach to withdrawing and withholding treatments is that: if withholding is acceptable, then withdrawing is too; early access is in principle problematic; but if early access is to be given, physicians must inform patients that the treatment will be withdrawn if it does not get reimbursed (Paper IV).
    List of papers
    1. Withdrawing or withholding treatments in health care rationing: an interview study on ethical views and implications
    Open this publication in new window or tab >>Withdrawing or withholding treatments in health care rationing: an interview study on ethical views and implications
    2022 (English)In: BMC Medical Ethics, E-ISSN 1472-6939, Vol. 23, no 1, article id 63Article in journal (Refereed) Published
    Abstract [en]

    Background When rationing health care, a commonly held view among ethicists is that there is no ethical difference between withdrawing or withholding medical treatments. In reality, this view does not generally seem to be supported by practicians nor in legislation practices, by for example adding a grandfather clause when rejecting a new treatment for lacking cost-effectiveness. Due to this discrepancy, our objective was to explore physicians and patient organization representatives experiences- and perceptions of withdrawing and withholding treatments in rationing situations of relative scarcity. Methods Fourteen semi-structured interviews were conducted in Sweden with physicians and patient organization representatives, thematic analysis was used. Results Participants commonly express internally inconsistent views regarding if withdrawing or withholding medical treatments should be deemed as ethically equivalent. Participants express that in terms of patients need for treatment (e.g., the treatments effectiveness and the patients medical condition) withholding and withdrawing should be deemed ethically equivalent. However, in terms of prognostic differences, and the patient-physician relation and communication, there is a clear discrepancy which carry a moral significance and ultimately makes withdrawing psychologically difficult for both physicians and patients, and politically difficult for policy makers. Conclusions We conclude that the distinction between withdrawing and withholding treatment as unified concepts is a simplification of a more complex situation, where different factors related differently to these two concepts. Following this, possible policy solutions are discussed for how to resolve this experienced moral difference by practitioners and ease withdrawing treatments due to health care rationing. Such solutions could be to have agreements between the physician and patient about potential future treatment withdrawals, to evaluate the treatments effect, and to provide guidelines on a national level.

    Place, publisher, year, edition, pages
    BMC, 2022
    Keywords
    Reimbursement; Disinvestment; Qualitative research; Priority setting; Equivalence thesis; Sweden
    National Category
    Medical Ethics
    Identifiers
    urn:nbn:se:liu:diva-186819 (URN)10.1186/s12910-022-00805-9 (DOI)000815483600001 ()35751123 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council for Health, Working Life and Welfare [FORTE 2019-01101]; Linkoping University

    Available from: 2022-07-05 Created: 2022-07-05 Last updated: 2025-04-16
    2. Withdrawing versus Withholding Treatments in Medical Reimbursement Decisions: A Study on Public Attitudes
    Open this publication in new window or tab >>Withdrawing versus Withholding Treatments in Medical Reimbursement Decisions: A Study on Public Attitudes
    Show others...
    2024 (English)In: Medical decision making, ISSN 0272-989X, E-ISSN 1552-681X, Vol. 44, no 6, p. 641-648Article in journal (Refereed) Published
    Abstract [en]

    BackgroundThe use of policies in medical treatment reimbursement decisions, in which only future patients are affected, prompts a moral dilemma: is there an ethical difference between withdrawing and withholding treatment?DesignThrough a preregistered behavioral experiment involving 1,067 participants, we tested variations in public attitudes concerning withdrawing and withholding treatments at both the bedside and policy levels.ResultsIn line with our first hypothesis, participants were more supportive of rationing decisions presented as withholding treatments compared with withdrawing treatments. Contrary to our second prestated hypothesis, participants were more supportive of decisions to withdraw treatment made at the bedside level compared with similar decisions made at the policy level.ImplicationsOur findings provide behavioral insights that help explain the common use of policies affecting only future patients in medical reimbursement decisions, despite normative concerns of such policies. In addition, our results may have implications for communication strategies when making decisions regarding treatment reimbursement.

    Place, publisher, year, edition, pages
    Sage Publications, 2024
    Keywords
    experiment, priority setting, health policy, equivalence thesis
    National Category
    Health Care Service and Management, Health Policy and Services and Health Economy Economics
    Identifiers
    urn:nbn:se:liu:diva-205746 (URN)10.1177/0272989x241258195 (DOI)001252816000001 ()38912645 (PubMedID)
    Funder
    Forte, Swedish Research Council for Health, Working Life and Welfare, Forte
    Note

    Funding Agencies|Swedish Research Council for Health, Working Life and Welfare (Forte) [19-01101]

    Available from: 2024-07-01 Created: 2024-07-01 Last updated: 2025-04-16
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  • Public defence: 2025-05-23 13:15 Key 1, Key-huset, LinköpingOrder onlineBuy this publication >>
    Lindeberg, Jenny Sofie
    Linköping University, Department of Culture and Society, Division of History, Arts and Religious Studies. Linköping University, Faculty of Arts and Sciences.
    Pälsbranschen som lokalt kulturarv: Kulturarvsskapande processer i Tranås 1938–20252025Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This dissertation uses historical perspectives to examine how the fur industry was constructed as a cultural heritage in the Swedish small town Tranås between the years 1938 and 2025. The aim is to contribute to a deeper understanding of how heritage is created in processes at local level and shows that such processes need to be understood in relation to local contexts. This is done through theoretical and methodological developments that are tested on the source materials. The empirical focus of the study is how different actors shaped this cultural heritage by constructing published stories, an archive, a collection, and museum exhibitions. These constructions are analysed by focusing on three phases respectively inspired by postmodern archival theory: initiation, fixation, and activation. The results show that local companies, businessmen and craftsmen had greater opportunities than other groups to initiate and participate in constructions of and negotiations about the content and meanings of this cultural heritage. This is reflected in the content that was fixated in publications, the archive and collection, and the museum exhibitions which was constantly focused on, or related to, a grand narrative of businesses, businessmen and craftsmen. The analysis of activations reveals that this narrative has persisted over time, through new initiations and fixations. Throughout the study it is also shown that silences were created around certain experiences and events, such as workers’ experiences or events of animal rights activism. In sum, studying how cultural heritage was created in three phases has revealed the conditions that enabled constructions of the fur industry as an unproblematic part of the local cultural heritage in Tranås. One of these conditions was a local authorized heritage discourse which gave certain actors, and their constructions of this heritage, greater influence than others. These constructions persisted even when the fur industry became a contested and critiqued phenomenon, both in Sweden and internationally. The dissertation thus contributes to research on contested heritage by showing how local contexts enabled the fur industry to be constructed as an unproblematic cultural heritage even when the fur industry was contested.

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