liu.seSearch for publications in DiVA
1 - 16 of 16
rss atomLink to result list
Permanent link
  • Public defence: 2017-01-30 10:15 Visionen, House B, Linköping
    Melot, Nicolas
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Melot, Nicolas
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Algorithms and Framework for Energy Efficient Parallel Stream Computing on Many-Core Architectures2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The rise of many-core processor architectures in the market answers to a constantly growing need of processing power to solve more and more challenging problems such as the ones in computing for big data. Fast computation is more and more limited by the very high power required and the management of the considerable heat produced. Many programming models compete to take profit of many-core architectures to improve both execution speed and energy consumption, each with their advantages and drawbacks. The work described in this thesis is based on the dataflow computing approach and investigates the benefits of a carefully pipelined execution of streaming applications, focusing in particular on off- and on-chip memory accesses. As case study, we implement classic and on-chip pipelined versions of mergesort for Intel SCC and Xeon. We see how the benefits of the on-chip pipelining technique are bounded by the underlying architecture, and we explore the problem of fine tuning streaming applications for many-core architectures to optimize for energy given a throughput budget. We propose a novel methodology to compute schedules optimized for energy efficiency given a fixed throughput target. We introduce \emph{Drake}, derived from Schedeval, a tool that generates pipelined applications for Many-Core architectures and allows the performance testing in time or energy of their static schedule. We show that streaming applications based on Drake compete with specialized implementations and we use Schedeval to demonstrate performance differences between schedules that are otherwise considered as equivalent by a simple model.

  • Public defence: 2017-02-01 10:15 ACAS, A-huset, Linköping
    Saeedi, Mohammad Reza
    Linköping University, Department of Management and Engineering. Linköping University, Faculty of Science & Engineering.
    Saeedi, Mohammad Reza
    Linköping University, Department of Management and Engineering. Linköping University, Faculty of Science & Engineering.
    Pluripotent Dynamic Capabilities in the Internationalization of Firms: Focus on Learning, Innovating and Networking in SMEs from Sweden2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Internationalization of small and medium-sized enterprises (SMEs) has been a considerable concern for international business (IB) scholars. Particularly, for those economies such as Sweden with small local markets, internationalization of SMEs could be fundamental. The firm-specific advantages (FSAs), including what the firm has and does, are crucial for SMEs to overcome in the face of their numerous different obstacles such as liability of smallness (LOS) and liability of foreignness (LOF).

    Examining the extant literature on the evolution of IB theories indicates that over time, IB scholars have been reaching to dynamic-based FSAs (what the firm does) as the source of developing and protecting sustainable competitive advantages (SCA) across national borders in a changing business environment. The nature of dynamic-based FSAs could be similar to dynamic capabilities. But, when it comes to determining specific component factors  of dynamic-based  FSAs  (as dynamic  capabilities),  there has been little agreement between IB researchers. In other words, the room of the dynamic capabilities is still dark. In this respect, shedding light into this room, particularly in the area of IB studies, is crucial. In addition, after determining the component factors of the dynamic-based FSAs, it is also critical to know the likely relationships between the identified component factors as well as their impact on the SMEs’ international performance (IP) as an important outcome of the internationalization. This means that there is a potential theoretical gap associated with the conceptualization of the component factors of the dynamic-based FSAs on one hand, and a potential empirical gap on the other. Given both theoretical and empirical research gaps, the purpose of this study is to examine, from a theoretical perspective, the nature of the dynamic-based FSA and its related component factors in the IB context, as well as empirically explore how SMEs’ IP is influenced by the identified component factors of the dynamic-based FSAs.

    To perform this study, first of all, based on lenses of the resource-based view (RBV) and dynamic capability view (DCV), the literature on organizational capability in the context of the IB studies was systematically reviewed to fill the theoretical gap. Consequently, three component factors of dynamic-based FSAs including networking capability (NC) as a relational-based FSA, innovative capability (IC) as an innovative-based FSA and absorptive capacity (ACAP) as a learning-based FSA were identified, all of which are pluripotent and dynamic in nature. Then, a deductive approach was followed to develop several hypotheses and the associated conceptual model. Furthermore, a survey strategy, collecting data from 330 Swedish internationalized manufacturing SMEs, was applied to accomplish the purpose of the study. Then, the Partial Least Squares Structural Equation Modeling (PLS-SEM) as a quantitative method was used to analyze the collected data.

    The results of the PLS-SEM analysis show that the SMEs’ international performance (IP) is positively influenced by the three identified component factors, whether directly or indirectly. In this regard, ACAP and NC are the two reliable predictors (directly) of the SMEs’ IP. The results indicate that innovative capability (IC) does not have direct impact on the SMEs’ IP, and that its effect is fully transmitted on IP only by the mediating effect of the networking capability (NC). Further analysis showed that ACAP, as an endogenous latent variable, additionally has a positive indirect association with SMEs’ international performance (IP). Moreover, the results also indicate that innovative capability is directly and positively affected by ACAP (innovating-by-learning effect). It was also empirically revealed that ACAP is a very strong predictor for networking capability, which is labeled as the networking-by-learning effect. Another major finding was that in internationalized SMEs, NC is strongly, directly and positively affected by IC; this effect also is termed as the networking-by-innovating effect. The overall picture resulting from the PLS- SEM analysis indicates that ACAP in internationalized SMEs is a wellspring to develop both innovative capability and networking capability, as well as influence SMEs’ IP. Furthermore, these results suggest that the networking capability is a vital gateway to transmit the effect of the other two component factors on IP and, at the same time, directly influence IP.

  • Public defence: 2017-02-02 09:00 Berzeliussalen, Linköping
    Stratmann, Johannes
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Stratmann, Johannes
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Genetic Mechanisms during Terminal Cell Fate Specification in the Drosophila CNS2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Specification of the many unique neuronal subtypes found in the nervous system depends on spatiotemporal cues and terminal selector cascades, mostly acting in sequential combinatorial codes of transcription factors (TFs) to dictate cell fate. Out of 10,000 cells in the Drosophila embryonic ventral nerve cord (VNC), only 28 cells selectively express Nplp1. The Nplp1 neurons in the Drosophila VNC can be subdivided into the thoracic ventro-lateral Tv1 and the dorsal-medial dAp neurons. Nplp1 expression in both cell subtypes is activated by the same terminal selector cascade: col > ap/eya > dimm > Nplp1. However Tv1 and dAp neurons are generated by different neuronal progenitors (neuroblasts, NB), and depend on different upstream cues to activate the cell specification cascade. The Tv1 cells are generated by NB5-6T, and in these cells the Nplp1 terminal selector cascade is triggered by spatio-temporal input provided by Antp/hth/exd/lbe/cas. Our studies identified that NB4-3 gives rise to the dAp cells and that the Nplp1 terminal selector cascade in dAp cells is activated by Kr/pdm>grn. I demonstrated how two different spatio-temporal combinations can funnel on a shared downstream terminal selector cascade to determine a highly related cell fate, in different regions of the VNC. I tested this scenario at the molecular level, by identification of cisregulatory modules (CRMs) for the main factors involved in the Nplp1 terminal selector cascade. Intriguingly, I found that col is under control of two separate CRMs, which are controlled by either Antp/hth/exd/lbe/cas in the NB5-6T lineage, and Kr/pdm/grn in the NB4-3 lineage. In addition, CRISPR deletion of the endogenous col CRMs did not result in loss of Col and Nplp1, indicating that col might be under control of more, yet unidentified CRMs. Nplp1 is expressed in one out of four cells in the thoracic Apterous cluster (Ap cluster); the Tv1 cell. The allocation of the right cell fate to each of the four Ap cluster cells, is regulated by the sub-temporal cascade including the factors Sqz/Nab/Svp, acting downstream of the temporal factor Cas. The sub-temporal factors have a repressive action on Col and Dimm, and thus on the terminal selector cascade regulating Nplp1 expression in the Tv1  cell. We demonstrated that the late and Tv1 specific expression of the early temporal factor Kr suppresses Svp in the Tv1 cell and allows for the progression of the Nplp1 cell fate specification cascade. Hence, early temporal factors involved in temporal progression of neuronal progenitors, can be re-utilized late and postmitotically to specify cell fate. It is tempting to speculate that similar mechanisms act to generate similar cell fate in different regions of the CNS, as well as the issue of sub-temporal multitasking, are common features both in Drosophila and higher organisms.

    List of papers
    1. Neuronal Cell Fate Specification by the Convergence of Different Spatiotemporal Cues on a Common Terminal Selector Cascade
    Open this publication in new window or tab >>Neuronal Cell Fate Specification by the Convergence of Different Spatiotemporal Cues on a Common Terminal Selector Cascade
    Show others...
    2016 (English)In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 14, no 5, e1002450- p.Article in journal (Refereed) Published
    Abstract [en]

    Specification of the myriad of unique neuronal subtypes found in the nervous system depends upon spatiotemporal cues and terminal selector gene cascades, often acting in sequential combinatorial codes to determine final cell fate. However, a specific neuronal cell subtype can often be generated in different parts of the nervous system and at different stages, indicating that different spatiotemporal cues can converge on the same terminal selectors to thereby generate a similar cell fate. However, the regulatory mechanisms underlying such convergence are poorly understood. The Nplp1 neuropeptide neurons in the Drosophila ventral nerve cord can be subdivided into the thoracic-ventral Tv1 neurons and the dorsal-medial dAp neurons. The activation of Nplp1 in Tv1 and dAp neurons depends upon the same terminal selector cascade: colamp;gt;ap/eyaamp;gt;dimmamp;gt;Nplp1. However, Tv1 and dAp neurons are generated by different neural progenitors (neuroblasts) with different spatiotemporal appearance. Here, we find that the same terminal selector cascade is triggered by Kr/pdmamp;gt;grn in dAp neurons, but by Antp/hth/exd/lbe/cas in Tv1 neurons. Hence, two different spatiotemporal combinations can funnel into a common downstream terminal selector cascade to determine a highly related cell fate.

    Place, publisher, year, edition, pages
    PUBLIC LIBRARY SCIENCE, 2016
    National Category
    Developmental Biology
    Identifiers
    urn:nbn:se:liu:diva-129501 (URN)10.1371/journal.pbio.1002450 (DOI)000376906100001 ()27276273 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council (VR-NT) [621-2010-5214]; Wallenberg Foundation [KAW2012.0101]; Swedish Cancer Foundation [120531]; Spanish Ministerio de Economia y Competitividad [BFU2013-43858-P]

    Available from: 2016-06-20 Created: 2016-06-20 Last updated: 2016-12-15
    2. Neuronal cell fate diversification controlled by sub-temporal action of Kruppel
    Open this publication in new window or tab >>Neuronal cell fate diversification controlled by sub-temporal action of Kruppel
    2016 (English)In: eLIFE, E-ISSN 2050-084X, Vol. 5, e19311e19311Article in journal (Refereed) Published
    Abstract [en]

    During Drosophila embryonic nervous system development, neuroblasts express a programmed cascade of five temporal transcription factors that govern the identity of cells generated at different time-points. However, these five temporal genes fall short of accounting for the many distinct cell types generated in large lineages. Here, we find that the late temporal gene castor sub-divides its large window in neuroblast 5-6 by simultaneously activating two cell fate determination cascades and a sub-temporal regulatory program. The sub-temporal program acts both upon itself and upon the determination cascades to diversify the castor window. Surprisingly, the early temporal gene Kruppel acts as one of the sub-temporal genes within the late castor window. Intriguingly, while the temporal gene castor activates the two determination cascades and the sub-temporal program, spatial cues controlling cell fate in the latter part of the 5-6 lineage exclusively act upon the determination cascades.

    Place, publisher, year, edition, pages
    eLife Sciences Publications Ltd., 2016
    National Category
    Immunology in the medical area
    Identifiers
    urn:nbn:se:liu:diva-132850 (URN)10.7554/eLife.19311 (DOI)000386456200001 ()27740908 (PubMedID)
    Note

    Funding Agencies|Svenska Forskningsradet Formas [621-2013-5258]; Cancerfonden [120531]; Knut och Alice Wallenbergs Stiftelse [KAW2011.0165]; Ministerio de Industria, Energia y Turismo [BFU2013-43858-P]

    Available from: 2016-12-06 Created: 2016-11-30 Last updated: 2016-12-29
  • Public defence: 2017-02-03 09:00 Berzeliussalen, Linköping
    Liljeroos, Maria
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences.
    Liljeroos, Maria
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Medicine and Health Sciences.
    Caring needs in patient-partner dyads affected by heart failure: An evaluation of the long-term effects of a dyadic psycho-educational intervention2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Introduction: As medical treatment has improved, patients with heart failure (HF) now live longer and care mostly takes place at home with partners providing the main assistance. Taking care of an ill or disabled individual imposes a well-documented burden on the partner’s healthrelated quality of life. The awareness of partners’ burdensome situation is increasing, but few interventions have targeted the needs of patientpartner dyads with HF. The results have been inconclusive and give no clear guidance on how interventional programmes should be designed to improve both patient and partner outcomes.

    Aim: The overall aim of this thesis was to evaluate the effects of a psychoeducational intervention delivered to patient-partner dyads with HF during long-term follow-up, and to explore the dyads’ perceived caring needs.

    Methods: The thesis is based on four papers that used both quantitative and qualitative data. Study I and II used a randomized controlled design with a follow-up assessment after 24 months including 155 patientpartner dyads. The control group received care as usual. The intervention group received care as usual, and in addition they participated in the nurse-led psycho-educational intervention. Data was collected using questionnaires before and 24 months after the intervention, in order to determine the long-term effects on patients and partners regarding health related quality of life, perceived control, symptoms of depression and partners’ caregiver burden (I, II). A conceptual health promotion model inspired the intervention. To describe how the model was applied, a qualitative approach analysing nurses’ documentation of the sessions with 71 dyads in the intervention group (III) was used. Study IV has an explorative design. To further explore the dyads’ perceived caring needs, focus groups interviews with 19 patient-partner dyads with heart failure (IV) were performed.

    Results: The intervention did not have any significant effect on physical or mental health- related quality of life, depressive symptoms, or perceived control over the heart failure among the dyads (I) or caregiver burden in the partners (II) after 24 months. Furthermore, time to first event did not differ significantly between the dyads in the intervention group and the control group (I, II). As for the partners, both the intervention and control group reported decreased physical health between the baseline assessment and the 24-month follow-up (I). The intervention was composed of three components; 1) cognitive 2) supportive, and 3) behavioural component. The analysis of the nurses’ documentation confirmed the coverage of all the components and the analysis revealed a vide range of caring needs among the dyads (III). The dyads described a need to learn about HF to be able to manage everyday life. Regular outpatient clinic visits and access to telephone support were vital and both the patient and the partner need to be present at the clinic visits. Meeting others who are in the same situation and sharing the burden in nurse-led group sessions was proposed as an opportunity to support each other and others (IV).

    Conclusions: Over the 24-month follow-up period, the intervention had a neutral effect on health- related quality of life, depressive symptoms and perceived control over the HF among the dyads, and on partners’ caregiver burden. Considering the fact that partners serve as a critical extension of the formal healthcare system, and that both patients and partners ask for more support, it will become crucial to find new ways to support dyads affected by heart failure. This thesis may be viewed as a first step in trying to understand dyads’ perceived caring needs, and it can serve as a guide in clinical work and when designing new dyadic interventions.

    List of papers
    1. Long Term Follow-Up after a Randomized Integrated Educational and Psychosocial Intervention in Patient-Partner Dyads Affected by Heart Failure
    Open this publication in new window or tab >>Long Term Follow-Up after a Randomized Integrated Educational and Psychosocial Intervention in Patient-Partner Dyads Affected by Heart Failure
    Show others...
    2015 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 9, e0138058- p.Article in journal (Refereed) Published
    Abstract [en]

    Background To date, contemporary heart failure care remains patient-focused, but awareness of the partners and families situation is increasing. Randomized studies have mainly evaluated the short-term effects of dyadic interventions. Therefore, the aim of this study was to determine the 24-month effects of an intervention with psych-educational support in dyads of heart failure patients and their partners. Methods This study used a randomized study design and 155 patient-partner dyads were enrolled. The intervention included a nurse-led program of three sessions addressing psychoeducational support. Results The intervention did not have any effect on health, depressive symptoms or perceived control among the patient-partner dyads after 24 months. Furthermore, time to first event did not differ significantly between the intervention group and the control patients. Conclusion This study may be regarded as a first step in trying to understand dyads need for supportive care. Individualized and more targeted interventions seem necessary to achieve a higher impact on dyad outcomes.

    Place, publisher, year, edition, pages
    PUBLIC LIBRARY SCIENCE, 2015
    National Category
    Clinical Medicine Sociology
    Identifiers
    urn:nbn:se:liu:diva-122211 (URN)10.1371/journal.pone.0138058 (DOI)000361800700030 ()26406475 (PubMedID)
    Note

    Funding Agencies|Centre for Clinical Research Sormland; Linkoping University; Swedish Research Council; Swedish Institute for Health Sciences

    Available from: 2015-10-26 Created: 2015-10-23 Last updated: 2016-12-13
    2. Long-term effects of a dyadic psycho-educational intervention on caregiver burden and morbidity in partners of patients with heart failure: a randomized controlled trial
    Open this publication in new window or tab >>Long-term effects of a dyadic psycho-educational intervention on caregiver burden and morbidity in partners of patients with heart failure: a randomized controlled trial
    Show others...
    2016 (English)In: Quality of Life Research, ISSN 0962-9343, E-ISSN 1573-2649, 1-13 p.Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    Background

    Partners of patients with heart failure provide both practical and emotional support. Many partners assume caregiving responsibilities without being aware of the burden related with this role.

    Objective

    Our work has established that a psycho-educational intervention has benefits at 3, but not at 12 months for patients with heart failure. Further we had not described the long-term effects in caregivers. This study aimed to determine the 24-months effects of a dyadic psycho-educational intervention on caregiver burden and morbidity in partners of patients with heart failure and study factors associated with a change in caregiver burden.

    Design

    A randomized controlled study design, with a follow-up assessment after 24 months.

    Setting and participants

    Partners to patients with heart failure were recruited from two hospitals in the southeast of Sweden.

    Intervention

    A three session nurse-led psycho-educational program was tested and included psychosocial support to maintain the partners’ physical and mental functions, and perceived control. Several instrument were used to measure caregiver burden, perceived control, physical and mental health, depression and morbidity.

    Results

    One hundred fifty-five partners were included. There were no significant differences in any index of caregiver burden or morbidity among the partners in the intervention and control groups after 24 months. Overall, the mean total caregiver burden was found to be significantly increased compared to baseline (36 ± 12 vs 38 ± 14, p < 0.05). A younger partner, less comorbidity, higher levels of perceived control, better physical health and less symptoms of depression in patients, and better mental health in the partners were factors associated with absence of increased caregiver burden over time.

    Discussion and conclusion

    Our intervention did not significantly decrease caregiver burden or morbidity. Over time, several aspects of burden increased in both groups. To improve outcomes, individualized and targeted interventions might be beneficial.

    Place, publisher, year, edition, pages
    Dordrecht: Springer Netherlands, 2016
    National Category
    Nursing Physiotherapy Family Medicine Psychiatry Geriatrics
    Identifiers
    urn:nbn:se:liu:diva-133178 (URN)10.1007/s11136-016-1400-9 (DOI)27631892 (PubMedID)2-s2.0-84986309447 (ScopusID)
    Available from: 2016-12-13 Created: 2016-12-13 Last updated: 2016-12-21Bibliographically approved
    3. Perceived caring needs in patient-partner dyads affected by heart failure: A qualitative study.
    Open this publication in new window or tab >>Perceived caring needs in patient-partner dyads affected by heart failure: A qualitative study.
    2014 (English)In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 23, no 19-20, 2928-2938 p.Article in journal (Refereed) Published
    Abstract [en]

    AIMS AND OBJECTIVES: To explore the perceived caring needs in patient-partner dyads affected by heart failure to develop an understanding of potential areas of support.

    BACKGROUND: Being affected by heart failure has a great impact on both the patient and the partner but until now contemporary care has remained patient focused.

    DESIGN: A qualitative study design was used.

    METHODS: Eight focus group interviews were performed, which included nineteen patients diagnosed with heart failure and their cohabiting partner. Patients were aged between 55-89 years and partners' ages ranged from 48-87 years. Data were analysed using qualitative content analyses.

    RESULTS: The dyads perceived that caring needs could be summarised in two themes 'Dyads perceive a need for continuous guidance through the different phases of the illness trajectory' and 'Dyads perceive a need to share burden and support with each other and others'. The dyads described a need to learn more about heart failure to be able to manage everyday life. Regular outpatient clinic visits and access to telephone support were vital, and having someone who cared about the well-being of the partners was perceived as comforting. Both the patient and the partner need to be present at the clinic visits. Receiving the same information and being able to ask questions reduce insecurity. Meeting others in the same situation and sharing the burden in group sessions were proposed as an opportunity to support each other and others.

    CONCLUSIONS: There is a need to improve education and support for patient-partner dyads affected by heart failure.

    RELEVANCE TO CLINICAL PRACTICE: The result shows the importance to provide continuous healthcare contacts throughout the illness trajectory. Furthermore, partners should be included at follow-up, and support groups should be organised so that dyads can meet and support each other.

    Place, publisher, year, edition, pages
    Wiley-Blackwell, 2014
    Keyword
    heart failure, family, partner, focus groups, qualitative study, psychosocial nursing
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-107727 (URN)10.1111/jocn.12588 (DOI)000343857700023 ()24698101 (PubMedID)
    Available from: 2014-06-19 Created: 2014-06-19 Last updated: 2016-12-13
  • Public defence: 2017-02-03 10:15 Planck, Fysikhuset, Linköping
    Speda, Jutta
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Speda, Jutta
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Methods development for metaproteomics-guided bioprospecting of novel enzymes2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Industrial biotechnology has been announced by several organizations and governments as a key enabling technology for the enhanced economic growth in a low-carbon and knowledge-based bioeconomy. An important goal to promote an environment friendly and sustainable industrial biotechnology is the discovery of new enzymes.

    To date, almost all enzymes used in industry have been discovered by pure culturing of microorganisms, however, it is known that less than 1% of all microorganisms can be obtained in pure cultures. The remaining majority of microorganisms is only viable by close biological interactions provided in microbial communities and is not available for enzyme discovery using the classical pure culture approaches. The investigation of microbial communities, which can be viewed as metaorganisms, has been enabled during the last two decades by refining established methods for the analysis of genes, mRNA or proteins and are called metagenomics, metatranscriptomics and metaproteomics, respectively. To date, these techniques have mostly been used in the field of microbial ecology for the understanding of the composition, function and metabolism of microbial communities but not for the purpose of bioprospecting for novel enzymes. Identification of genes that code for possible enzyme candidates is hindered, due to the fact that 30-40% of the sequenced metagenomes contain genes coding for unidentified proteins. Additionally, the -omics techniques generate large amounts of data that need to be analyzed and the outcome of the analysis does not necessarily lead to the discovery of novel applicable enzymes.

    The work presented in this thesis describes the establishment of the necessary conditions for a metaproteomics-based method that allows for a straightforward and targeted identification of novel enzymes with desired activity from microbial communities. The approach provides a valuable alternative to the incomplete and inefficient analysis of non-targeting data and laborious workflow, which is typically generated by the established meta-omics techniques. In developing the methods presented in this thesis, microbial communities in constructed environments were established, which allowed for the controlled expression of extracellular hydrolytic enzymes under defined conditions. By combination and modulation of advanced metaproteomics and metagenomics techniques, we were able to directly identify the enzymes and the corresponding gene sequences of several cellulolytic enzymes as a first example for the feasibility of this approach.

    List of papers
    1. Applying theories of microbial metabolism for induction of targeted enzyme activity in a methanogenic microbial community at a metabolic steady state
    Open this publication in new window or tab >>Applying theories of microbial metabolism for induction of targeted enzyme activity in a methanogenic microbial community at a metabolic steady state
    2016 (English)In: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614, Vol. 100, no 18, 7989-8002 p.Article in journal (Refereed) Published
    Abstract [en]

    Novel enzymes that are stable in diverse conditions are intensively sought because they offer major potential advantages in industrial biotechnology, and microorganisms in extreme environments are key sources of such enzymes. However, most potentially valuable enzymes are currently inaccessible due to the pure culturing problem of microorganisms. Novel metagenomic and metaproteomic techniques that circumvent the need for pure cultures have theoretically provided possibilities to identify all genes and all proteins in microbial communities, but these techniques have not been widely used to directly identify specific enzymes because they generate vast amounts of extraneous data. In a first step towards developing a metaproteomic approach to pinpoint targeted extracellular hydrolytic enzymes of choice in microbial communities, we have generated and analyzed the necessary conditions for such an approach by the use of a methanogenic microbial community maintained on a chemically defined medium. The results show that a metabolic steady state of the microbial community could be reached, at which the expression of the targeted hydrolytic enzymes were suppressed, and that upon enzyme induction a distinct increase in the targeted enzyme expression was obtained. Furthermore, no cross talk in expression was detected between the two focal types of enzyme activities under their respective inductive conditions. Thus, the described approach should be useful to generate ideal samples, collected before and after selective induction, in controlled microbial communities to clearly discriminate between constituently expressed proteins and extracellular hydrolytic enzymes that are specifically induced, thereby reducing the analysis to only those proteins that are distinctively up-regulated.

    Place, publisher, year, edition, pages
    Springer, 2016
    Keyword
    Microbial community; Enzyme discovery; Metaproteomics; Biogas; Cellulase; Protease
    National Category
    Microbiology
    Identifiers
    urn:nbn:se:liu:diva-131888 (URN)10.1007/s00253-016-7547-z (DOI)000382008000017 ()27115757 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [621-2009-4150]; InZymes Biotech AB

    Available from: 2016-10-13 Created: 2016-10-11 Last updated: 2016-12-14
    2. Assessment of sample preparation methods for metaproteomics of extracellular proteins
    Open this publication in new window or tab >>Assessment of sample preparation methods for metaproteomics of extracellular proteins
    2017 (English)In: Analytical Biochemistry, ISSN 0003-2697, E-ISSN 1096-0309, Vol. 516, 23-36 p.Article in journal (Refereed) Published
    Abstract [en]

    Enzyme discovery in individual strains of microorganisms is compromised by the limitations of pure culturing. In principle, metaproteomics allows for fractionation and study of different parts of the protein complement but has hitherto mainly been used to identify intracellular proteins. However, the extracellular environment is also expected to comprise a wealth of information regarding important proteins. An absolute requirement for metaproteomic studies of protein expression, and irrespective of downstream methods for analysis, is that sample preparation methods provide clean, concentrated and representative samples of the protein complement. A battery of methods for concentration, extraction, precipitation and resolubilization of proteins in the extracellular environment of a constructed microbial community was assessed by means of 2D gel electrophoresis and image analysis to elucidate whether it is possible to make the extracellular protein complement available for metaproteomic analysis. Most methods failed to provide pure samples and therefore negatively influenced protein gel migration and gel background clarity. However, one direct precipitation method (TCA-DOC/acetone) and one extraction/precipitation method (phenol/methanol) provided complementary high quality 2D gels that allowed for high spot detection ability and thereby also spot detection of less abundant extracellular proteins.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    Keyword
    Enzyme discovery, Microbial community, Metaproteome, Extracellular, Sample preparation, 2D gel electrophoresis
    National Category
    Analytical Chemistry Biocatalysis and Enzyme Technology
    Identifiers
    urn:nbn:se:liu:diva-132902 (URN)10.1016/j.ab.2016.10.008 (DOI)000388056800005 ()27742212 (PubMedID)
    Funder
    Swedish Research Council, 621-2009-4150
    Note

    Funding agencies: Swedish Research Council [621-2009-4150]; Tekniska Verken i Linkoping AB; InZymes Biotech AB

    Available from: 2016-12-01 Created: 2016-12-01 Last updated: 2016-12-14Bibliographically approved
  • Public defence: 2017-02-03 13:15 ACAS, A-huset, Linköping
    Noroozi, Sayeh
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, Faculty of Science & Engineering.
    Noroozi, Sayeh
    Linköping University, Department of Management and Engineering, Production Economics. Linköping University, Faculty of Science & Engineering.
    Sales and operations planning based on a modularized view of supply chains: Supporting process industries and discrete manufacturing industries2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of this dissertation is to propose a framework for sales and operations planning (S&OP), which is based on a modularized view of supply chains. The framework should support both process industries and discrete manufacturing industries in their quest for performance. S&OP has been highlighted in this framework due to its essential role in integrating different functions within a company and integrating a company with its supply chain partners (referred to as horizontal integration), and linking different planning levels in a company (referred to as vertical integration). As an integrator, S&ÖP influences companies’ performance.

    Originally, S&OP was developed as a generic process but still in line with the requirements of discrete manufacturing industries. The specific requirements of process industries have not been emphasized in this process to the same extent. In order to suggest a modularized S&OP framework for both process industries and  discrete manufacturing  industries, a systematic literature review is performed to understand the specific characteristics of S&OP in process industries. As a result, the importance of continuity/discontinuity of materials and its influence on the required production processes are highlighted. This indicates that the production process in process industries is actually a hybrid of continuous production and discrete production, whereas the discrete manufacturing industries often only deploy discrete production. Continuous production has specific characteristics that would be beneficial to include in the S&OP process; nonetheless, this is in contrast to the view in the literature that considers S&OP a generic process. Generic here means that S&OP is independent of the context in terms of, for example, the industry in which it is implemented. This issue is investigated in this dissertation by identifying the requirements, which can be considered in the S&OP of process industries as add-ons to the generic S&OP. In addition to this, two other concepts addressing the properties of the production process are identified as important in planning and control, including S&OP. One addresses the level of repetitivity of the production process in response to the market demand, and the other concerns the trigger of the production flow. The three concepts are related to three different types of decoupling points and are the basis for a typology developed herein that provides a modularized view of supply chains. The application of the typology to S&OP leads to a modularized S&OP framework applicable to both process industries and discrete manufacturing industries. The modularized view of supply chains has been long emphasized as an effective and efficient way to support companies’ performance and their competitive position. The typology and the S&OP framework are developed through conceptual research methods.

    To study how the modularized S&ÖP framework is related to companies’ performance measures, different performance measures (including sustainable performance measures) at the S&OP level are extracted from the literature. The performance measures are then classified according to the typology, and linked to strategic performance attributes. Aligning performance measures at S&OP levels and strategic performance attributes would help in enhancing companies’ performance. Sustainable performance measures are included in this classification to provide additional support for companies’ performance. Finally, this approach in classification of  performance measures is studied in four case companies, and the empirical performance measures are linked to the companies’ strategic performance attributes and competitive strategies. The results of this empirical study have, to some extent, verified the results from the classification of performance measures based on the literature.

    This dissertation contributes to the development of knowledge in S&OP. First, it identifies three key concepts in planning and control of manufacturing companies. Second, it investigates how S&OP should be tailored to the specific characteristics of companies and their supply chains. The modularized S&OP framework developed in this dissertation is based on the three identified concepts. This framework provides a foundation for fulfilling the supply chains needs by suggesting decision-making processes, planning techniques, and performance measures for different modules. More specifically, this work investigates how S&OP should be designed and implemented in process industries, which has not been extensively studied before. Third, this dissertation shows how S&OP level performance measures can be selected in line with the specific characteristics of supply chains. Finally, by integrating the sustainable performance measures in the S&OP process, this dissertation expands the scope of S&OP and its potential in supporting companies’ performance.

    List of papers
    1. A modularised typology for flow design based on decoupling points - a holistic view on process industries and discrete manufacturing industries
    Open this publication in new window or tab >>A modularised typology for flow design based on decoupling points - a holistic view on process industries and discrete manufacturing industries
    2016 (English)In: Production planning & control (Print), ISSN 0953-7287, E-ISSN 1366-5871, Vol. 27, no 16, 1344-1355 p.Article in journal (Refereed) Published
    Abstract [en]

    Management of production activities covers a wide range of decisions. In this paper, a modularised approach is suggested that, through configuration, generates a case-specific flow design. The approach is based on identification of decision categories that are generic and fundamental in the flow design, covering both discrete manufacturing industries and process industries. Each decision category identifies a unique property of the flow which changes at a particular point: this is termed a decoupling point. A three-dimensional modularised typology is developed by combining three different decision categories. Cases from the steel industry and the tooling industry are used to illustrate how the typology can be applied. The modularised approach provides a typology for the application of both qualitative and quantitative methods for flow management, including planning, control and performance management.

    Place, publisher, year, edition, pages
    TAYLOR & FRANCIS LTD, 2016
    Keyword
    Typology; decoupling point; planning and control; process industry; modularisation
    National Category
    Production Engineering, Human Work Science and Ergonomics
    Identifiers
    urn:nbn:se:liu:diva-132245 (URN)10.1080/09537287.2016.1220649 (DOI)000384468200004 ()
    Note

    Funding Agencies|Swedish Foundation for Strategic Research [PIC-LI]; Process Industrial IT and Automation (PiiA) - VINNOVA; Swedish Energy Agency, Formas; Swedish industry [2014-05110]

    Available from: 2016-10-24 Created: 2016-10-21 Last updated: 2016-12-19
    2. A modularized framework for sales and operations planning with focus on process industries
    Open this publication in new window or tab >>A modularized framework for sales and operations planning with focus on process industries
    2016 (English)In: Production & Manufacturing Research, ISSN 2169-3277, Vol. 4, no 1, 65-89 p.Article in journal (Refereed) Published
    Abstract [en]

    This paper suggests a modularized sales and operations planning (S&OP) framework, consisting of content and process. The framework’s content is based on a typology of decoupling points in which the effect of decoupling points on the decision variables in S&OP is studied. The framework’s process takes a step back and addresses the need for a more elaborate design to precede the operational use of S&OP content for different production contexts. The framework supports both process industries (PIs) and discrete manufacturing industries (DIs), and recognizes their specific requirements and reflects them in their S&OP. The differentiating characteristics of PIs and DIs are emphasized through three different decoupling points, namely: discretization decoupling point, control mode decoupling point, and customer order decoupling point. The suggested framework aims to fill the gap in the literature regarding the lack of aggregate planning processes that match the PIs’ specific requirements by reflecting the differentiating characteristics of PIs in S&OP.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2016
    National Category
    Economics and Business Other Mechanical Engineering Software Engineering
    Identifiers
    urn:nbn:se:liu:diva-133240 (URN)10.1080/21693277.2016.1200502 (DOI)
    Available from: 2016-12-15 Created: 2016-12-15 Last updated: 2017-01-08Bibliographically approved
    3. S&OP related key performance measures with integration of sustainability: a decoupling point based and modularized view on supply chains
    Open this publication in new window or tab >>S&OP related key performance measures with integration of sustainability: a decoupling point based and modularized view on supply chains
    2017 (English)In: International manufacturing strategy in a time of great flux / [ed] Louis Brennan, Alessandra Vecchi, Cham: Springer, 2017, 197-233 p.Chapter in book (Refereed)
    Abstract [en]

    Key performance measures (KPMs) play an important role in the management of supply chains. An important integrator of the supply chain management is Sales and Operations Planning (S&OP) that connects the strategic and operational plans. S&OP usually impacts supply chain performance through the management of resources and customer satisfaction. This paper suggests a new classification for S&OP-related KPMs. The classification follows a typology of decision categories which are based on decoupling points. The typology supports a modularized approach to supply chain design and provides the possibility to select the KPMs according to the decision criteria of each module. The KPMs are further linked to the SCOR performance attributes to provide the link to the companies’ strategic directives and the strategic conflicts which appear in the modules of the typology are discussed. The sustainable KPMs have also been included in order to provide opportunities for improved sustainable performance. The integration of sustainable KPMs helps in creating competitive advantages for companies through development of capabilities which are beneficial but hard to replicate by competitors. The paper ends with an example that illustrates how the classification can be applied to a case company.

    Place, publisher, year, edition, pages
    Cham: Springer, 2017
    Series
    Measuring Operations Performance, ISSN 2363-9970
    Keyword
    Key performance measures, Sales and operations planning, Sustainability, SCOR model, Decoupling points
    National Category
    Business Administration Other Mechanical Engineering Environmental Management Transport Systems and Logistics Social Sciences Interdisciplinary
    Identifiers
    urn:nbn:se:liu:diva-133242 (URN)10.1007/978-3-319-25351-0_10 (DOI)9783319253503 (Print) (ISBN)9783319253510 (online) (ISBN)
    Available from: 2016-12-15 Created: 2016-12-15 Last updated: 2016-12-22Bibliographically approved
  • Public defence: 2017-02-07 13:00 Belladonna, Linköping
    Olofsson, Magnus
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Olofsson, Magnus
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Microbiological Surveillance in Primary Health Care: New Aspects of Antimicrobial Resistance and Molecular Epidemiology in an Ageing Population2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background

    The inexorable rise in antimicrobial resistance (AMR) interferes with the goals of health care services around the world, given how critical the antibacterials are in making infections treatable and surgical procedures doable. Nursing homes residents have been identified as a reservoir for AMR, possibly due to the combination of being physically and mentally frail, frequently treated with antibacterials, and frequently moved between nursing home and hospital. Microbiological surveillance is a key countermeasure against further AMR development. Yet, surveillance data is easily biased due to precision problems regarding how the data is collected and evaluated.

    Methods

    Beginning in 2008, we launched two programmes (“SHADES” and “MIDIO”) aimed to gathering AMR data in a systematic fashion from elderly nursing home residents and elderly people living in their own place of residence. In doing so, we focused on colonizing strains of the two most important nosocomial infectious agents, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The bacteria were collected from multiple body sites and analysed with respect to antimicrobial susceptibility and genetic diversity.

    Results

    Active surveillance of AMR showed that (i) a S. aureus isolate could be retrieved from 1 in every 2 individuals given a single round of sampling, but aggregating several rounds of sampling, this figure might reach 7 in every 10 individuals, (ii) an E. coli isolate could be retrieved from 4 in every 5 individuals, (iii) the overall prevalence of AMR was favourable when compared to the situation in many other countries, (iv) the genetic diversity of S. aureus was generally high and provided only limited evidence of clonal expansion or contraction, and (v) diabetes mellitus was one of very few patient-level factors to show an association with the degree of genetic diversity in S. aureus.

    Conclusions

    The prevalence of colonization with S. aureus and E. coli was somewhat higher than expected, but the degree of AMR was very low. The genetic diversity of S. aureus was generally high. Diabetes mellitus emerged as the only patient-level factor associated with a higher degree of genetic diversity in S. aureus.

    List of papers
    1. Colonization with Staphylococcus aureus in Swedish nursing homes: A cross-sectional study
    Open this publication in new window or tab >>Colonization with Staphylococcus aureus in Swedish nursing homes: A cross-sectional study
    Show others...
    2012 (English)In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 44, no 1, 3-8 p.Article in journal (Refereed) Published
    Abstract [en]

    Background: Screening for bacterial colonization among risk populations could provide better estimates of the volume of the bacteria-related disease reservoir and the level of antimicrobial resistance, than do conventional laboratory reports. Methods: Two hundred and one participants at 10 Swedish nursing homes were screened for colonization with Staphylococcus aureus between January and October 2009. Of the 201 participants, 61 (30%) were male. The median age was 86 y. All participants were systematically sampled from the nasal mucosa, the pharyngeal mucosa, the groin, and active skin lesions, if any. Results: Ninety-nine of 199 participants (50%) were colonized with S. aureus. The colonization rate was 34% for the nose, 35% for throat, 10% for groin, and 54% for active skin lesions. An antibiotic-resistant S. aureus isolate was identified in 8.5% of all participants regardless of colonization status. A total of 24 resistant isolates were detected, and 21 of these were resistant to fluoroquinolones. There was no case of colonization with methicillin-resistant S. aureus (MRSA). Conclusions: The presence of resistant isolates was generally low, and the greater part of the resistance was fluoroquinolone-related. To achieve reasonable precision, screening programmes of this kind must include samples from both the nose and throat, and, although low, the prevalence of antimicrobial resistance in Swedish nursing homes still calls for reflection on how to use the fluoroquinolones wisely. © 2012 Informa Healthcare.

    Place, publisher, year, edition, pages
    Informa Healthcare, 2012
    Keyword
    Colonization; Drug resistance (bacterial); Methicillin-resistant Staphylococcus aureus; Nursing homes; Staphylococcus aureus
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-74118 (URN)10.3109/00365548.2011.598875 (DOI)
    Available from: 2012-01-20 Created: 2012-01-19 Last updated: 2016-12-19Bibliographically approved
    2. Prevalence and molecular epidemiology of Staphylococcus aureus in Swedish nursing homes – as revealed in the SHADES study
    Open this publication in new window or tab >>Prevalence and molecular epidemiology of Staphylococcus aureus in Swedish nursing homes – as revealed in the SHADES study
    Show others...
    2014 (English)In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 142, no 6, 1310-1316 p.Article in journal (Refereed) Published
    Abstract [en]

    Knowledge of carriage and population dynamics of Staphylococcus aureus is crucial for infection risk assessment and to reveal transmission patterns of strains. We report the prevalence and molecular epidemiology of S. aureus in elderly people (n = 290) living in nursing homes in three cities in the south of Sweden. The overall carriage prevalence rate was 48% when results from nares (31%) and throat (34%) samples were combined. Common spa types were equally distributed but a frequent type, t160, was found only in one of the regions. Carriage of different spa types was detected in 23% of individuals and antimicrobial resistance rates were higher in S. aureus isolates from those carrying more than one spa type. Five of the 21 individuals who carried different spa types were colonized simultaneously with resistant and non-resistant strains. Seventeen per cent of the individuals carried S. aureus of the same spa type on all occasions. Methicillin resistance was not detected. In conclusion we found a high prevalence of S. aureus in this elderly population with a high rate of dual colonization with different spa types. We also found signs of institutional spread of one strain.

    Place, publisher, year, edition, pages
    Cambridge University Press, 2014
    Keyword
    Colonization, molecular typing, multiclonality, nursing home, spa type
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-97342 (URN)10.1017/S0950268813002033 (DOI)000334247600020 ()23962597 (PubMedID)
    Available from: 2013-09-10 Created: 2013-09-10 Last updated: 2016-12-19Bibliographically approved
    3. Low level of antimicrobial resistance in Escherichia coli among Swedish nursing home residents
    Open this publication in new window or tab >>Low level of antimicrobial resistance in Escherichia coli among Swedish nursing home residents
    Show others...
    2013 (English)In: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 45, no 2, 117-123 p.Article in journal (Refereed) Published
    Abstract [en]

    Background: Screening for bacterial colonization and antimicrobial resistance (AMR) among a defined population could aid in the identification of at-risk populations and provide targets for antibiotic stewardship and infection control programmes. Methods: Two hundred and sixty-eight participants at 11 Swedish nursing homes underwent serial screening for colonization with Escherichia coli between March 2008 and September 2010. Seventy-two of the 268 participants (27%) were male. The median age was 85 y. Samples were collected from urine, the rectal mucosa, the groin, and active skin lesions. Results: Two hundred and nine of 268 participants (78%) were colonized with E. coli at any body site/fluid. The specific colonization rates were 81% (rectum), 48% (urine), 30% (groin), 59% (unknown), and 13% (skin lesion). An antibiotic-resistant E. coli isolate was identified in 18% of all participants regardless of colonization status; all together, 87 resistant isolates were detected. Only 1 participant carried isolates with resistance to third-generation cephalosporins (cefotaxime and ceftazidime). Conclusions: The presence of resistance was generally low, and the greater part of the resistant cases was connected with 3 common antibiotics: ampicillin, trimethoprim/sulfamethoxazole, and ciprofloxacin. In spite of generally increasing resistance against third-generation cephalosporins in E. coli in Sweden, this study does not implicate residence at a Swedish nursing home as a risk factor for the acquisition of expressed cephalosporin resistance.

    Place, publisher, year, edition, pages
    Informa Healthcare, 2013
    Keyword
    Mass screening, colonization, nursing homes, drug resistance, bacterial, Escherichia coli
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-85105 (URN)10.3109/00365548.2012.717232 (DOI)000313677200006 ()22992114 (PubMedID)
    Available from: 2012-11-02 Created: 2012-11-02 Last updated: 2016-12-19
  • Public defence: 2017-02-10 09:00 Berzeliussalen, Linköping
    Gunnar, Erika
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Gunnar, Erika
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Regulatory programs controlling profileration during Drosophila nervous system development2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The central nervous system (CNS) is the most complex organ in the body, responsible for complex functions, including thinking, reasoning and memory. The CNS contains cells of many different types, often generated in vast numbers. Hence, CNS development requires precise genetic control of both cell fate and of cell proliferation, to generate the right number of cells, with the proper identity, and in the proper location. The cells also need to make connections with each other for correct signaling and function. This complexity evokes the question of how this is regulated. How does the stem cells, responsible for building the CNS, know how many times to divide, and how does the daughters know which identity to acquire and in which location they shall end up? During Drosophila melanogaster development, the neuroblasts (NBs) are responsible for generating the CNS. In each hemisegment, every NB is unique in identity, and generates a predetermined number of daughters with specific identities. The lineages of different NBs vary in size, but are always the same for each specific NB, and the division modes of each NBs is hence stereotyped. Most NBs start dividing by renewing themselves while generating daughters that will in turn divide once to generate two neurons and/or glia (denoted type I mode). Many, maybe all, NBs later switch to generating daughters that will differentiate directly into a neuron or glia (denoted type 0 mode). This type I>0 switch occurs at different time-points during lineage progression, and influences the total numbers of cells generated from a single NB.

    The work presented in this thesis aimed at investigating the genetic regulation of proliferation, with particular focus on the type I>0 switch. In the first project, the implication of the Notch pathway on the type I>0 switch was studied. Mutants of the Notch pathway do not switch, and the results show that the Notch pathway regulates the switch by activation of several target genes, both regulators and cell cycle genes. One of the target genes, the E(spl)-C genes, have been difficult to study due to functional redundancy. This study reveals that even though they can functionally compensate for each other, they have individual functions in different lineages. Regarding cell cycle genes, both Notch and E(spl)-C regulate several key cell cycle genes, and molecular analysis indicated that this regulation is direct. In the second project we studied the seq gene, previously identified in a genetic screen. We found that seq controls the type I>0 switch by regulating the key cell cycle genes, but also through interplay with the Notch pathway. Notch and seq stop proliferation, and in the third project we wanted to identify genes that drive proliferation. We found that there is battery of early NB genes, socalled early factors, which activate the cell cycle, and drive NB and daughter proliferation. These are gradually replaced by late regulators, and the interplay between early and late factors acts to achieve precise control of lineage progression.

    The work presented here increases our understanding of how regulatory programs act to control the development of the CNS; to generate the right number of cells of different identities. These results demonstrate the importance of correct regulation of proliferation in both stem cells and daughters. Problems in this control can result in either an underdeveloped CNS or loss of control such as in cancer. Knowledge about these regulatory programs can contribute to the development of therapeutics against these diseases.

    List of papers
    1. Control of Neural Daughter Cell Proliferation by Multi-level Notch/Su(H)/E(spl)-HLH Signaling
    Open this publication in new window or tab >>Control of Neural Daughter Cell Proliferation by Multi-level Notch/Su(H)/E(spl)-HLH Signaling
    Show others...
    2016 (English)In: PLoS Genetics, ISSN 1553-7390, E-ISSN 1553-7404, Vol. 12, no 4, e1005984Article in journal (Refereed) Published
    Abstract [en]

    The Notch pathway controls proliferation during development and in adulthood, and is frequently affected in many disorders. However, the genetic sensitivity and multi-layered transcriptional properties of the Notch pathway has made its molecular decoding challenging. Here, we address the complexity of Notch signaling with respect to proliferation, using the developing Drosophila CNS as model. We find that a Notch/Su(H)/E(spl)-HLH cascade specifically controls daughter, but not progenitor proliferation. Additionally, we find that different E(spl)-HLH genes are required in different neuroblast lineages. The Notch/Su(H)/E(spl)-HLH cascade alters daughter proliferation by regulating four key cell cycle factors: Cyclin E, String/Cdc25, E2f and Dacapo (mammalian p21(CIP1)/p27(KIP1)/p57(Kip2)). ChIP and DamID analysis of Su(H) and E(spl)-HLH indicates direct transcriptional regulation of the cell cycle genes, and of the Notch pathway itself. These results point to a multi-level signaling model and may help shed light on the dichotomous proliferative role of Notch signaling in many other systems.

    Place, publisher, year, edition, pages
    PUBLIC LIBRARY SCIENCE, 2016
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-128759 (URN)10.1371/journal.pgen.1005984 (DOI)000375231900032 ()27070787 (PubMedID)
    Note

    Funding Agencies|Knut and Alice Wallenberg Foundation [KAW2012.0101]; Swedish Research Council [621-2010-5214]; Swedish Cancer Foundation [120531]

    Available from: 2016-05-31 Created: 2016-05-30 Last updated: 2016-12-29
    2. sequoia controls the type I>0 daughter proliferation switch in the developing Drosophila nervous system
    Open this publication in new window or tab >>sequoia controls the type I>0 daughter proliferation switch in the developing Drosophila nervous system
    2016 (English)In: Development, ISSN 0950-1991, E-ISSN 1477-9129, Vol. 143, no 20, 3774-3784 p.Article in journal (Refereed) Published
    Abstract [en]

    Neural progenitors typically divide asymmetrically to renew themselves, while producing daughters with more limited potential. In the Drosophila embryonic ventral nerve cord, neuroblasts initially produce daughters that divide once to generate two neurons/glia (type I proliferation mode). Subsequently, many neuroblasts switch to generating daughters that differentiate directly (type 0). This programmed type I&gt;0 switch is controlled by Notch signaling, triggered at a distinct point of lineage progression in each neuroblast. However, how Notch signaling onset is gated was unclear. We recently identified Sequoia (Seq), a C2H2 zinc-finger transcription factor with homology to Drosophila Tramtrack (Ttk) and the positive regulatory domain (PRDM) family, as important for lineage progression. Here, we find that seq mutants fail to execute the type I&gt;0 daughter proliferation switch and also display increased neuroblast proliferation. Genetic interaction studies reveal that seq interacts with the Notch pathway, and seq furthermore affects expression of a Notch pathway reporter. These findings suggest that seq may act as a context-dependent regulator of Notch signaling, and underscore the growing connection between Seq, Ttk, the PRDM family and Notch signaling.

    Place, publisher, year, edition, pages
    The Company of Biologists Ltd, 2016
    Keyword
    Lineage tree, Cell cycle, Asymmetric division, Combinatorial control, Notch
    National Category
    Cell and Molecular Biology Biochemistry and Molecular Biology Cell Biology Medical Biotechnology
    Identifiers
    urn:nbn:se:liu:diva-132739 (URN)10.1242/dev.139998 (DOI)27578794 (PubMedID)
    Available from: 2016-11-22 Created: 2016-11-22 Last updated: 2016-12-29Bibliographically approved
  • Public defence: 2017-02-10 09:00 Hugo Theorell, Linköping
    Rejmstad, Peter
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, Faculty of Science & Engineering.
    Rejmstad, Peter
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, Faculty of Science & Engineering.
    Optical Monitoring of Cerebral Microcirculation2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The cerebral microcirculation consists of a complex network of small blood vessels that support nerve cells with oxygen and nutrition. The blood flow and oxygen delivery in the microcirculatory blood vessels are regulated through mechanisms which may be influenced or impaired by disease or brain damage resulting from conditions such as brain tumors, traumatic brain injury or subarachnoid hemorrhage (SAH). Monitoring of parameters relating to the microvascular circulation is therefore needed in the clinical setting. Optical techniques such as diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) are capable of estimating the oxygen saturation (SO2) and tracking the microvascular blood flow (perfusion) using a fiber optic probe. This thesis presents the work carried out to adapt DRS and LDF for monitoring cerebral microcirculation in the human brain.

    A method for real-time estimation of SO2 in brain tissue was developed based on the P3 approximation of diffuse light transport and quadratic polynomial fit to the measured DRS signal. A custom-made fiberoptic probe was constructed for measurements during tumor surgery and in neurointensive care. Software modules with specific user interface for LDF and DRS were programmed to process, record and present parameters such as perfusion, total backscattered light, heart rate, pulsatility index, blood fraction and SO2 from acquired signals.

    The systems were evaluated on skin, and experimentally by using optical phantoms with properties mimicking brain tissue. The oxygen pressure (pO2) in the phantoms was regulated to track spectroscopic changes coupled with the level of SO2. Clinical evaluation was performed during intraoperative measurements during tumor surgery (n = 10) and stereotactic deep brain stimulation implantations (n = 20). The LDF and DRS systems were also successfully assessed in the neurointensive care unit for a patient treated for SAH. The cerebral autoregulation was studied by relating the parameters from the optical systems to signals from the standard monitoring equipment in neurointensive care.

    In summary, the presented work takes DRS and LDF one step further toward clinical use for optical monitoring of cerebral microcirculation.

    List of papers
    1. A laser Doppler system for monitoring of intracerebral microcirculation
    Open this publication in new window or tab >>A laser Doppler system for monitoring of intracerebral microcirculation
    2012 (English)In: Conf Proc IEEE Eng Med Biol Soc., ISSN 1557-170X, 1988-1991 p.Article in journal (Refereed) Published
    Abstract [en]

    A two-channel standard laser Doppler perfusion monitor has been adapted for intracerebral measurements. Software developed in Labview makes it possible to present the microvascular perfusion, total light intensity (TLI), heart rate and trend curves in real-time during surgery. A custom-made optical probe was designed in order to enable easy fixation during brain surgery. The constructed brain probe was evaluated and compared to a standard probe. Both probes presented similar feasibility when used for the skin recordings. In addition, evaluation was done in one patient in relation to tumor resection. Stable perfusion and TLI signals were immediately recorded when the probe was positioned in cerebral tissue. Movement artifacts were clearly seen when the probe was moved to a new site. Recordings in cortex and tumor border showed higher perfusion and lower TLI compared to measurements in subcortical white matter. The calculated heart rate estimate agreed well with the noted value from the electrocardiographic patient monitoring system.                                                                                                                                                      

    Place, publisher, year, edition, pages
    IEEE, 2012
    National Category
    Medical Engineering
    Identifiers
    urn:nbn:se:liu:diva-86150 (URN)10.1109/EMBC.2012.6346346 (DOI)000313296502058 ()23366307 (PubMedID)978-1-4244-4119-8 (ISBN)e-978-1-4244-4120-4 (ISBN)978-1-4577-1787-1 (ISBN)
    Funder
    Swedish Research Council
    Available from: 2012-12-07 Created: 2012-12-07 Last updated: 2017-01-11Bibliographically approved
    2. A laser Doppler system for monitoring of cerebral microcirculation: implementation and evaluation during neurosurgery
    Open this publication in new window or tab >>A laser Doppler system for monitoring of cerebral microcirculation: implementation and evaluation during neurosurgery
    2016 (English)In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, ISSN 0140-0118, Vol. 54, no 1, 123-131 p.Article in journal (Refereed) Published
    Abstract [en]

    The aim of this study was to adapt and evaluate laser Doppler perfusion monitoring (LDPM) together with custom designed brain probes and software for continuous recording of cerebral microcirculation in patients undergoing neurosurgery. The LDPM system was used to record perfusion and backscattered light (TLI). These parameters were displayed together with the extracted heart rate (HR), pulsatility index (PI) and signal trends from adjustable time intervals. Technical evaluation was done on skin during thermal provocation. Clinical measurements were performed on ten patients undergoing brain tumour surgery. Data from 76 tissue sites were captured with a length varying between 10 s to 15 min. Statistical comparisons were done using Mann-Whitney tests. Grey and tumour tissue could be separated from white matter using the TLI-signal (p < 0.05). The perfusion was significantly higher in grey and tumour tissue compared to white matter (p < 0.005). LDPM was successfully used as an intraoperative tool for monitoring local blood flow and additional parameters linked to cerebral microcirculation (perfusion, TLI, heart rate and PI) during tumour resection. The systems stability opens up for studies in the postoperative care of patients with e.g. traumatic brain injury or subarachnoid haemorrhage.

    Place, publisher, year, edition, pages
    Springer Berlin/Heidelberg, 2016
    Keyword
    Microcirculation, Brain tumour Laser Doppler perfusion monitoring (LDPM), Pulsatility index (PI), Neurosurgery
    National Category
    Medical Laboratory and Measurements Technologies
    Identifiers
    urn:nbn:se:liu:diva-120632 (URN)10.1007/s11517-015-1332-5 (DOI)000371437900010 ()26105147 (PubMedID)
    Funder
    Swedish Research Council, 6212-010-4216
    Available from: 2015-08-20 Created: 2015-08-20 Last updated: 2017-01-11
    3. A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy
    Open this publication in new window or tab >>A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy
    2016 (English)In: Journal of Biophotonics, ISSN 1864-063X, E-ISSN 1864-0648Article in journal (Refereed) Epub ahead of print
    Abstract [en]

    Continuous measurement of local brain oxygen saturation (SO2) can be used to monitor the status of brain trauma patients in the neurocritical care unit. Currently, micro-oxygen-electrodes are considered as the “gold standard” in measuring cerebral oxygen pressure (pO2), which is closely related to SO2 through the oxygen dissociation curve (ODC) of hemoglobin, but with the drawback of slow in response time. The present study suggests estimation of SO2 in brain tissue using diffuse reflectance spectroscopy (DRS) for finding an analytical relation between measured spectra and the SO2 for different blood concentrations. The P3 diffusion approximation is used to generate a set of spectra simulating brain tissue for various levels of blood concentrations in order to estimate SO2. The algorithm is evaluated on optical phantoms mimicking white brain matter (blood volume of 0.5–2%) where pO2 and temperature is controlled and on clinical data collected during brain surgery. The suggested method is capable of estimating the blood fraction and oxygen saturation changes from the spectroscopic signal and the hemoglobin absorption profile.

    Place, publisher, year, edition, pages
    Wiley-VCH Verlagsgesellschaft, 2016
    Keyword
    oxygenation, diffuse reflectance spectroscopy, hemoglobin, optical phantom, human brain
    National Category
    Other Medical Engineering
    Identifiers
    urn:nbn:se:liu:diva-127362 (URN)10.1002/jbio.201500334 (DOI)27094015 (PubMedID)
    Available from: 2016-04-22 Created: 2016-04-22 Last updated: 2017-01-11Bibliographically approved
  • Public defence: 2017-02-10 10:15 Planck (J206), Fysikhuset, Linköping
    Volpi, Riccardo
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, Faculty of Science & Engineering.
    Volpi, Riccardo
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, Faculty of Science & Engineering.
    Modelling Charge Transport for Organic Solar Cells within Marcus Theory2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With the technological advancement of modern society, electronic devices are getting progressively more integrated in our everyday lives. Their continuouslygrowing presence is generating numerous concerns about costs, efficiency and the environmental impact of the electronic waste. In this context, organic electronics is finding its way through the market, allowing for potentially low-cost, light, flexible, transparent and environmentally friendly electronics. Despite the numerous successes of organic electronics, the functioning of several categories of organic devices still represents a technological challenge, due to problems like low efficiencies and stabilities (degradation over time).

    Organic devices are composed by one or more organic materials depending on the particular application. The conformation and electronic structure of the organic molecules as well as their supramolecular arrangement in the single phase or at the interface are known to strongly a affect the mobility and/or the efficiency of the device. While there is consensus on the fundamental physics of organic devices, we still lack a detailed comprehensive theory able to fully explain experimental data. In this thesis we focus on trying to expand our knowledge of charge transport in organic materials through theoretical modelling and simulation of organic electronic devices. While the methodology developed is generally valid for any organic device, we will particularly focus on the case represented by organic photovoltaics.

    The morphology of the system is obtained by molecular dynamics simulations. Marcus theory is used to calculate the hopping rate of the charge carriers and subsequently study the possibility of free charge carriers production in an organic solar cell. The theory is then compared both with Kinetic Monte Carlo simulations and with experiments to identify the main pitfalls of the actual theory and ways to improve it. The Marcus rate between two molecules depends on the molecular orbital energies, the transfer integral between the two molecules and the reorganization energy. The orbital energies and the transfer integrals between two neighbouring molecules are obtained through quantum mechanical calculations in vacuum. Electrostatic effects of the environment are included through atomic charges and atomic polarizabilities, producing a correction both to the orbital energy and to the reorganization energy. We have studied several systems in the single phase (polyphenylene vinylene, C60, PC61BM) and at the interface between two organic materials (anthracene/C60, TQ1/PC71BM).

    We show how a combination of different methodologies can be used to obtain a realistic ab-initio model of organic devices taking into account environmental effects. This allows us to obtain qualitative agreement with experimental data of mobility in the single phase and to determine whether or not two materials are suitable to be used together in an organic solar cell.

    List of papers
    1. Transition fields in organic materials: From percolation to inverted Marcus regime. A consistent Monte Carlo simulation in disordered PPV
    Open this publication in new window or tab >>Transition fields in organic materials: From percolation to inverted Marcus regime. A consistent Monte Carlo simulation in disordered PPV
    2015 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 142, no 9, 094503- p.Article in journal (Refereed) Published
    Abstract [en]

    In this article, we analyze the electric field dependence of the hole mobility in disordered poly (p-phenylene vinylene). The charge carrier mobility is obtained from Monte Carlo simulations. Depending on the field strength three regions can be identified: the percolation region, the correlation region, and the inverted region. Each region is characterized by a different conduction mechanism and thus a different functional dependence of the mobility on the electric field. Earlier studies have highlighted that Poole-Frenkel law, which appears in the correlation region, is based on the type of correlation caused by randomly distributed electric dipoles. This behavior is thus observed in a limited range of field strengths, and by studying a broader range of electric fields, a more fundamental understanding of the transport mechanism is obtained. We identify the electric fields determining the transitions between the different conduction mechanisms in the material and we explain their physical origin. In principle, this allows us to characterize the mobility field dependence for any organic material. Additionally, we study the charge carrier trapping mechanisms due to diagonal and off-diagonal disorder, respectively. (C) 2015 AIP Publishing LLC.

    Place, publisher, year, edition, pages
    American Institute of Physics (AIP), 2015
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-117234 (URN)10.1063/1.4913733 (DOI)000350973900041 ()25747090 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council (VR); MATTER Network; SERC (Swedish e-Science Research Center)

    Available from: 2015-04-22 Created: 2015-04-21 Last updated: 2016-12-20
    2. Effect of Polarization on the Mobility of C60: A Kinetic Monte-Carlo Study
    Open this publication in new window or tab >>Effect of Polarization on the Mobility of C60: A Kinetic Monte-Carlo Study
    Show others...
    2016 (English)In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 12, no 2, 812-824 p.Article in journal (Refereed) Published
    Abstract [en]

    We present a study of mobility field and temperature dependence for C60 with Kinetic Monte-Carlo simulations. We propose a new scheme to take into account polarization effects in organic materials through atomic induced dipoles on nearby molecules. This leads to an energy correction for the single site energies and to an external reorganization happening after each hopping. The inclusion of polarization allows us to obtain a good agreement with experiments for both mobility field and temperature dependence.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2016
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-122989 (URN)10.1021/acs.jctc.5b00975 (DOI)000370112900032 ()
    Note

    Vid tiden för disputation förelåg publikationen endast som manuskript

    Funding agencies:  SeRC (Swedish e-Science Research Center)

    Available from: 2015-12-01 Created: 2015-12-01 Last updated: 2016-12-20Bibliographically approved
    3. Theoretical Study of the Charge-Transfer State Separation within Marcus Theory: The C-60-Anthracene Case Study
    Open this publication in new window or tab >>Theoretical Study of the Charge-Transfer State Separation within Marcus Theory: The C-60-Anthracene Case Study
    2016 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 37, 24722-24736 p.Article in journal (Refereed) Published
    Abstract [en]

    We study, within Marcus theory, the possibility of the charge-transfer (CT) state splitting at organic interfaces and a subsequent transport of the free charge carriers to the electrodes. As a case study we analyze model anthracene-C-60 interfaces. Kinetic Monte Carlo (KMC) simulations on the cold CT state were performed at a range of applied electric fields, and with the fields applied at a range of angles to the interface to simulate the action of the electric field in a bulk heterojunction (BHJ) interface. The results show that the inclusion of polarization in our model increases CT state dissociation and charge collection. The effect of the electric field on CT state splitting and free charge carrier conduction is analyzed in detail with and without polarization. Also, depending on the relative orientation of the anthracene and C-60 molecules at the interface, CT state splitting shows different behavior with respect to both applied field strength and applied field angle. The importance of the hot CT in helping the charge carrier dissociation is also analyzed in our scheme.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2016
    Keyword
    organic solar cell; charge transfer state; splitting separation; interface; Marcus theory; kinetic Monte Carlo
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:liu:diva-132221 (URN)10.1021/acsami.6b06645 (DOI)000384033600054 ()27561228 (PubMedID)
    Note

    Funding Agencies|SERC (Swedish e-Science Research Center)

    Available from: 2016-10-25 Created: 2016-10-21 Last updated: 2016-12-20
  • Public defence: 2017-02-10 10:15 ACAS, A-huset, Linköping
    Eslami, Mohammad H.
    Linköping University, Department of Management and Engineering, Project Innovations and Entrepreneurship. Linköping University, Faculty of Science & Engineering.
    Eslami, Mohammad H.
    Linköping University, Department of Management and Engineering, Project Innovations and Entrepreneurship. Linköping University, Faculty of Science & Engineering.
    Knowledge integration with customers in collaborative product developmentproject2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Driven by rapid technological developments, greater customer expectations, and increased product complexity,product development processes increasingly rely on the integration of dispersed specialist knowledge.Consequently, many industrial firms are changing the way they approach product development. Productdevelopment increasingly relies on knowledge integration across firm boundaries. Customers are one of the mostindispensable sources of knowledge, and their knowledge needs to be integrated during product development.However, little is known about the processes and mechanisms used to integrate customer knowledge in productdevelopment.Therefore, firms must devise processes and mechanisms that support knowledge integration withcustomers. This thesis aims to investigate knowledge integration with customers in collaborative productdevelopment.

    The work described in this thesis combines a case study with a survey approach. More specifically, five casestudies were conducted at three industrial manufacturing firms. Data were collected in 46 interviews, along withinformal discussions, workshops, and secondary material. The case studies revealed the role of knowledgeintegration, knowledge integration mechanisms, and the importance of contextual factors related to the customer’stechnical capability, and the locus of initiative for the product development project. A cross-sectional survey wasperformed in order to ascertain the role of knowledge integration and its effect on innovation performance and theeffect of firms and customers’ technical capability and locus of initiative on knowledge integration withcustomers. The survey study generated 216 responses from firms operating in the Swedish manufacturingindustry.

    This thesis consists of a compiled summary and five appended papers. The results in these provide the basis formodelling knowledge integration with customers. The findings confirm that integrating knowledge withcustomers in product development is associated with better innovation performance. Further, the results point tothe dynamic characteristics of knowledge integration in product development processes. More specifically, firmstend to apply different combinations of mechanisms in different phases, depending on the intended content of theknowledge contribution of the customer and the requirements of each phase in the development process. Inaddition, the degree of technical capability, internal integration capability, and locus of initiative are importantfactors influencing knowledge integration processes. This thesis sheds new light on collaborative productdevelopment with customers by demonstrating that knowledge, and particularly the integration of knowledgeacross firm boundaries, is a central property of product development. The study focuses on industrial andmanufacturing firms, complementing current perspectives on the role of customers in other sectors. In thisparticular sector, complexity and system-wide implications need to be resolved together with customers throughknowledge integration activities. An important implication of the thesis is that firms need to devise mechanismsfor knowledge integration with customers, and be prepared to redevise these as the firm progresses through theproduct development phases.

    List of papers
    1. Knowledge integration with customers in collaborative product development projects
    Open this publication in new window or tab >>Knowledge integration with customers in collaborative product development projects
    2016 (English)In: The journal of business & industrial marketing, ISSN 0885-8624, E-ISSN 2052-1189, Vol. 31, no 7, 889-900 p.Article in journal (Refereed) Published
    Abstract [en]

    Purpose This paper addresses the need for managerial and organizational approaches to knowledge integration with customer in collaborative product development projects. The purpose is to identify the roles of customers in terms of the customerᅵs knowledge contribution and timing of customer collaboration in the product development process. Design/methodology/approach This study is based on a multi-case study approach, comprising four product development projects from two large international suppliers. The cases were selected following the theoretical replication logic. Data consist of interviews, workshops, and secondary information. For each of the cases, a within case analysis was performed followed by a cross-case analysis. Findings The study shows that the customerᅵs knowledge contribution is aligned with the specific requirements of each phase of the product development. Three specific customer roles are identified and connected to the customerᅵs knowledge contribution and the timing of customer collaboration. The technical capability of the customer and the locus of initiative of the product development project are affecting the prerequisites for knowledge integration with customers. Research limitations/implications The study is performed from the perspective of supplier firms. We have not been able to capture the perspective of the customer in detail. As it is expected that both customers and suppliers benefit from a systematic knowledge exchange, future studies could examine knowledge contributions in both directions. Practical implications The findings can be used to devise effective approaches for collaborative product development with customers related to the customerᅵs knowledge contribution and the timing of customer collaboration and provide guidance to firms seeking to benefit from knowledge residing at customers. Originality/value This is one of the first studies to focus on the integration of customersᅵ knowledge in product development processes. This paper contributes to the customerᅵsupplier collaboration literature by presenting further insight into customersᅵ knowledge contributions, the timing of customer collaboration in product development processes and the prerequisites for knowledge integration with customers.

    National Category
    Economics Economics and Business
    Identifiers
    urn:nbn:se:liu:diva-130858 (URN)10.1108/JBIM-05-2014-0099 (DOI)
    Available from: 2016-08-29 Created: 2016-08-29 Last updated: 2017-01-17Bibliographically approved
    2. Internal integration in complex collaborative product development projects
    Open this publication in new window or tab >>Internal integration in complex collaborative product development projects
    2016 (English)In: International Journal of Innovation Management, ISSN 1363-9196, E-ISSN 1757-5877, Vol. 20, 1650008Article in journal (Refereed) Accepted
    Abstract [en]

    While the importance of internal integration for effective inter-firm collaboration with suppliers is widely acknowledged, it is presently unclear how it is achieved in complex collaborative product development projects. This paper aims to address this gap in extant knowledge by investigating the internal integration approaches and exploring related project management challenges. Specifically, three internal integration approaches are found, namely integration based on multidirectional, frequent interaction; integration based on delimited, problem-solving; and based on unidirectional, information-oriented interaction. The study findings suggest that internal integration approaches are related to the degree of uncertainty in the subsystems of the suppliers, rather than the overall product system. Consequently, in complex product development projects involving many internal functions and several different suppliers, the specific supplier tasks, rather than the overall project structure and aims, determine the mode of internal integration required. This complexity creates important challenges for organisation, and requires flexibility in internal integration approaches.

    Place, publisher, year, edition, pages
    World Scientific Publishing, 2016
    Keyword
    Internal integration; supplier involvement; task uncertainty; collaborative projects; subsystem; case study
    National Category
    Business Administration
    Identifiers
    urn:nbn:se:liu:diva-114889 (URN)10.1142/S1363919616500080 (DOI)
    Note

    The previous status of this article was Manuscript.

    Available from: 2015-03-05 Created: 2015-03-05 Last updated: 2017-01-17Bibliographically approved
  • Public defence: 2017-02-10 13:00 Berzeliussalen, Linköping
    Brohede, Sabina
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Paediatrics in Linköping.
    Brohede, Sabina
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center of Paediatrics and Gynaecology and Obstetrics, Department of Paediatrics in Linköping.
    Body Dysmorphic Disorder: Capturing a prevalent but under-recognized disorder2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background

    Individuals with body dysmorphic disorder (BDD) are highly distressed due to defects they perceive in their physical appearance that are not noticeable to others. The condition often leads to impaired functioning in relationships, socialization, and intimacy and a decreased ability to function in work, school, or other daily activities. Although BDD seems to be relatively prevalent, it is under-recognized by people in general and by health care professionals. Individuals with BDD are secretive about their symptoms, and they usually do not recognize that they are suffering from a psychiatric disorder. Instead, in an attempt to relieve their symptoms by correcting their perceived defects, they commonly seek dermatological treatment or cosmetic surgery. However, such interventions usually do not result in any decrease in BDD symptom severity, but can rather aggravate the symptoms. Therefore, it is crucial that health care professionals recognize BDD in order to offer adequate care. Prior to the studies conducted for this thesis, there were no known data regarding the prevalence of BDD in Sweden.

    Main aims

    (i) To translate a screening questionnaire for BDD (the Body Dysmorphic Disorder Questionnaire, BDDQ) into Swedish and validate the questionnaire in a community sample. (ii) To estimate the prevalence of BDD in the general population of Swedish women and in female dermatology patients. (iii) To explore BDD patients’ experiences of living with the disorder, including their experiences of the health care system.

    Methods

    The BDDQ was validated using the Structured Clinical Interview for DSM-IV (SCID) as the gold standard for diagnosing BDD (Study I). The validated BDDQ was used to estimate the prevalence of BDD in a randomly selected population-based sample of Swedish women (n=2 885) (Study II) and in a consecutive sample of female dermatology patients (n=425) (Study III). In Studies II and III, the Hospital Anxiety and Depression Scale was used to assess symptoms of depression and anxiety. In Study III, quality of life was evaluated by the Dermatology Life Quality Index. BDD patients’ lived experiences were explored using a qualitative research design (Study IV). Fifteen individuals with BDD were interviewed, and the interviews were analysed using Interpretive Description.

    Results

    The Swedish translation of the BDDQ displayed a sensitivity of 94%, a specidicity of 90% and a (positive) likelihood ratio of 9.4. The prevalence of women screening positive for BDD was 2.1% (95% CI 1.7–2.7) in the population-based sample of women and 4.9% (95% CI 3.2–7.4) in the dermatology patients’ sample. The positive predictive value of the BDDQ (71%) gave an estimated BDD prevalence of 1.5% (95% CI 1.1–2.0) in the female Swedish population. Women screening positive for BDD had signidicantly more symptoms of anxiety and depression compared to those screening negative for BDD in both samples. In the dermatology patients, quality of life was severely impaired in patients with positive BDD screening. The overarching concept found in Study IV was that patients with BDD felt imprisoned and were struggling to become free and to no longer feel abnormal. The participants had encountered difdiculties in accessing health care and had disappointing experiences of the health care system.

    Conclusion

    The findings of this thesis indicate that BDD is a relatively common disorder in the Swedish female population, and that it is more prevalent in dermatology patients. BDD patients struggle to be free from a feeling of imprisonment, and in this struggle they encounter difficulties in accessing health care. Therefore, it is important to increase awareness and recognition of BDD among health care professionals to ensure that patients with BDD receive the appropriate care.

    List of papers
    1. Validation of the Body Dysmorphic Disorder Questionnaire in a community sample of Swedish women
    Open this publication in new window or tab >>Validation of the Body Dysmorphic Disorder Questionnaire in a community sample of Swedish women
    2013 (English)In: Psychiatry Research, ISSN 0165-1781, E-ISSN 1872-7123, Vol. 210, no 2, 647-652 p.Article in journal (Refereed) Published
    Abstract [en]

    Body Dysmorphic Disorder (BDD) is characterized by a distressing and impairing preoccupation with a nonexistent or slight defect in appearance. Patients with the disorder present to both psychiatric and non-psychiatric physicians. A few studies have assessed BDD prevalence in the general population and have shown that the disorder is relatively common. To date, no BDD assessment instruments have been validated in the general population. Our aim was to validate a brief self-screening instrument, the Body Dysmorphic Disorder Questionnaire (BDDQ), in a female community sample. The BDDQ was translated into Swedish and filled out by 2891 women from a randomly selected community sample. The questionnaire was validated in a subsample of 88 women, using the Structured Clinical Interview for DSM-IV (SCID) together with clinical assessment as the gold standard. In the validation subsample, the BDDQ showed good concurrent validity, with a sensitivity of 94%, a specificity of 90% and a likelihood ratio of 9.4. The questionnaire can therefore be of value when screening for BDD in female populations.

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keyword
    Self-report instrument; Measurement; Somatoform disorders; Appearance concerns; Body image
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-103301 (URN)10.1016/j.psychres.2013.07.019 (DOI)000328518600044 ()
    Available from: 2014-01-17 Created: 2014-01-16 Last updated: 2016-12-22
    2. Prevalence of body dysmorphic disorder among Swedish women: A population-based study
    Open this publication in new window or tab >>Prevalence of body dysmorphic disorder among Swedish women: A population-based study
    2015 (English)In: Comprehensive Psychiatry, ISSN 0010-440X, E-ISSN 1532-8384, Vol. 58, 108-115 p.Article in journal (Refereed) Published
    Abstract [en]

    Background: Body dysmorphic disorder (BDD) is characterized by a highly distressing and impairing preoccupation with nonexistent or slight defects in appearance. Patients with BDD present to both psychiatric and non-psychiatric physicians. A few studies have assessed BDD prevalence in representative samples of the general population and have demonstrated that this disorder is relatively common. Our primary objective was to assess the prevalence of BDD in the Swedish population because no data are currently available. Methods: In the current cross-sectional study, 2891 randomly selected Swedish women aged 18-60 years participated. The occurrence of BDD was assessed using the Body Dysmorphic Disorder Questionnaire (BDDQ), which is a validated self-report measure derived from the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria for BDD. In addition, symptoms of depression and anxiety were measured using the Hospital Anxiety and Depression Scale (HADS). Results: The prevalence of BDD among Swedish women was 2.1%. The women with BDD had significantly more symptoms of depression and anxiety than the women without BDD. Depression (HADS depression score greater than= 8) and anxiety (HADS anxiety score greater than= 8) were reported by 42% and 72% of the women with BDD, respectively. Conclusions: The results of the present study indicate that BDD is relatively common among Swedish women (2.1%) and that it is associated with significant morbidity.

    Place, publisher, year, edition, pages
    WB Saunders, 2015
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:liu:diva-117368 (URN)10.1016/j.comppsych.2014.12.014 (DOI)000351807800015 ()25617963 (PubMedID)
    Note

    Funding Agencies|Linkoping University; Ostergotland County Council

    Available from: 2015-04-24 Created: 2015-04-24 Last updated: 2016-12-22
    3. I will be at deaths door and realize that Ive wasted maybe half of my life on one body part: the experience of living with body dysmorphic disorder
    Open this publication in new window or tab >>I will be at deaths door and realize that Ive wasted maybe half of my life on one body part: the experience of living with body dysmorphic disorder
    2016 (English)In: International journal of psychiatry in clinical practice (Print), ISSN 1365-1501, E-ISSN 1471-1788, Vol. 20, no 3, 191-198 p.Article in journal (Refereed) Published
    Abstract [en]

    Objectives: The purpose of this study was to explore the experiences of patients living with body dysmorphic disorder (BDD), including their experiences with the health care system. Methods: Fifteen individuals with BDD were interviewed, and interpretive description was used to analyse the interviews. Results: The following six themes were identified: being absorbed in time-consuming procedures, facing tension between ones own ideal and the perceived reality, becoming the disorder, being restricted in life, attempting to reduce ones problems and striving to receive care. The overarching concept derived from the themes was feeling imprisoned - struggling to become free and to no longer feel abnormal. Conclusions: Ideas of imprisonment and abnormality compose the entire experience of living with this disorder. Although the participants suffered greatly from their BDD, these patients encountered difficulties in accessing health care and had disappointing experiences during their encounters with the health care system. Therefore, it is important to increase awareness and knowledge of BDD among health care professionals to ensure that patients with BDD receive the appropriate care.

    Place, publisher, year, edition, pages
    TAYLOR & FRANCIS LTD, 2016
    Keyword
    Body dysmorphic disorder; body image; interview; qualitative research
    National Category
    Psychiatry
    Identifiers
    urn:nbn:se:liu:diva-131206 (URN)10.1080/13651501.2016.1197273 (DOI)000380144000013 ()27314665 (PubMedID)
    Available from: 2016-09-16 Created: 2016-09-12 Last updated: 2016-12-22
  • Public defence: 2017-02-16 10:15 Planck, Fysikhuset, Linköping
    Sukkaew, Pitsiri
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Sukkaew, Pitsiri
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    A Quantum Chemical Exploration of SiC Chemical Vapor Deposition2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    SiC is a wide bandgap semiconductor with many attractive properties. It hasattracted particular attentions in the areas of power and sensor devices as wellas biomedical and biosensor applications. This is owing to its properties suchas large bandgap, high breakdown electric field, high thermal conductivitiesand chemically robustness. Typically, SiC homoepitaxial layers are grownusing the chemical vapor deposition (CVD) technique. Experimental studiesof SiC CVD have been limited to post-process measuring of the layer ratherthan in situ measurements. In most cases, the observations are presented interms of input conditions rather than in terms of the unknown growth conditionnear the surface. This makes it difficult to really understand the underlyingmechanism of what causes the features observed experimentally. Withhelp of computational methods such as computational fluid dynamic (CFD)we can now explore various variables that are usually not possible to measure.CFD modeling of SiC CVD, however, requires inputs such as thermochemicalproperties and chemical reactions, which in many cases are not known. In thisthesis, we use quantum chemical calculations to provide the missing detailscomplementary to CFD modeling.

    We first determine the thermochemical properties of the halides and halohydridesof Si and C species, SiHnXm and CHnXm, for X being F, Cl and Brwhich were shown to be reliable compared to the available experimentaland/or theoretical data. In the study of gas-phase kinetics, we combine ab initiomethods and DFTs with conventional transition state theory to derive kineticparameters for gas phase reactions related to Si-H-X species. Lastly, westudy surface adsorptions related to SiC-CVD such as adsorptions of small CHand Si-H-X species, and in the case of C-H adsorption, the study was extendedto include subsequent surface reactions where stable surface productsmay be formed.

    List of papers
    1. Shortcomings of CVD modeling of SiC today
    Open this publication in new window or tab >>Shortcomings of CVD modeling of SiC today
    Show others...
    2013 (English)In: Theoretical Chemistry accounts, ISSN 1432-881X, E-ISSN 1432-2234, Vol. 132, no 11, 1398- p.Article in journal (Refereed) Published
    Abstract [en]

    The active, epitaxial layers of silicon carbide (SiC) devices are grown by chemical vapor deposition (CVD), at temperatures above 1,600 °C, using silane and light hydrocarbons as precursors, diluted in hydrogen. A better understanding of the epitaxial growth process of SiC by CVD is crucial to improve CVD tools and optimize growth conditions. Through computational fluid dynamic (CFD) simulations, the process may be studied in great detail, giving insight to both flow characteristics, temperature gradients and distributions, and gas mixture composition and species concentrations throughout the whole CVD reactor. In this paper, some of the important parts where improvements are very much needed for accurate CFD simulations of the SiC CVD process to be accomplished are pointed out. First, the thermochemical properties of 30 species that are thought to be part of the gas-phase chemistry in the SiC CVD process are calculated by means of quantum-chemical computations based on ab initio theory and density functional theory. It is shown that completely different results are obtained in the CFD simulations, depending on which data are used for some molecules, and that this may lead to erroneous conclusions of the importance of certain species. Second, three different models for the gas-phase chemistry are compared, using three different hydrocarbon precursors. It is shown that the predicted gas-phase composition varies largely, depending on which model is used. Third, the surface reactions leading to the actual deposition are discussed. We suggest that hydrocarbon molecules in fact have a much higher surface reactivity with the SiC surface than previously accepted values.

    Place, publisher, year, edition, pages
    Springer Berlin/Heidelberg, 2013
    Keyword
    Silicon carbide, Chemical vapor deposition, Computational fluid dynamics, Thermochemical data, Gas-phase reactions, Surface reactions
    National Category
    Physical Chemistry Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-103136 (URN)10.1007/s00214-013-1398-9 (DOI)000325107800001 ()
    Funder
    Swedish Foundation for Strategic Research , SM11-0051Swedish Foundation for Strategic Research , EM11-0034
    Available from: 2014-01-13 Created: 2014-01-13 Last updated: 2017-01-16
    2. Thermochemical Properties of Halides and Halohydrides of Silicon and Carbon
    Open this publication in new window or tab >>Thermochemical Properties of Halides and Halohydrides of Silicon and Carbon
    Show others...
    2016 (English)In: ECS Journal of Solid State Science and Technology, ISSN 2162-8769, E-ISSN 2162-8777, Vol. 5, no 2, P27-P35 p.Article in journal (Refereed) Published
    Abstract [en]

    Atomization energies, enthalpies of formation, entropies as well as heat capacities of the SiHnXm and CHnXm systems, with X being F, Cl and Br, have been studied using quantum chemical calculations. The Gaussian-4 theory (G4) and Weizman-1 theory as modified by Barnes et al. 2009 (W1RO) have been applied in the calculations of the electronic, zero point and thermal energies. The effects of low-lying electronically excited states due to spin orbit coupling were included for all atoms and diatomic species by mean of the electronic partition functions derived from the experimental or computational energy splittings. The atomization energies, enthalpies of formation, entropies and heat capacities derived from both methods were observed to be reliable. The thermochemical properties in the temperature range of 298-2500 K are provided in the form of 7-coefficient NASA polynomials. (C) The Author(s) 2015. Published by ECS. All rights reserved.

    Place, publisher, year, edition, pages
    ELECTROCHEMICAL SOC INC, 2016
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-124117 (URN)10.1149/2.0081602jss (DOI)000365748800023 ()
    Note

    Funding Agencies|Swedish Foundation for Strategic Research

    Available from: 2016-01-22 Created: 2016-01-19 Last updated: 2017-01-16
  • Public defence: 2017-02-17 13:00 Temcas, hus T, Linköping
    Söderström, Sara
    Linköping University, Department of Thematic Studies.
    Söderström, Sara
    Linköping University, Department of Thematic Studies.
    Regional Environmental Governance and Avenues for the Ecosystem Approach to management in the Baltic Sea Area2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis explores the avenues for the ecosystem approach to management in theBaltic Sea Region. This region is one of the most contaminated water bodies inthe world, although the first Regional Seas Convention was created here and theregion has a long history of cooperation and environmental protection. Thecurrent environmental governance arrangements are examined with specific focuson governance structures, cross-sectoral integration and ecological boundaries.The ecosystem approach to management as both a tool and vision of holisticmanagement of natural resources is traced through the evolution of environmentalgovernance, as well as its manifestation in contemporary environmental policiesin the region. It is found that the major EU directives, as well as HELCOMpolices, promote the ecosystem approach and that its presence has increased inrecent years; it is now the major guiding principle in European marinegovernance. However, the governance structures impede implementation indifferent ways. The environmental problem areas in the region all require differentgovernance arrangements, thus obstructing a holistic approach. The environmentalproblems per se also affect each other, necessitating far-reaching sectoralintegration and cross-border cooperation, which at present is the major obstacleregarding implementation. The contemporary trends combining solidregionalisation through HELCOM with increased Europeanisation and macroregionalisationby different EU initiatives offer some promise, but the crosssectoralimpediments must be resolved if the ecosystem approach is to become apractical approach and not just a policy principle.

    List of papers
    1. 'Environmental governance' and 'ecosystem management': avenues for synergies between two approaches
    Open this publication in new window or tab >>'Environmental governance' and 'ecosystem management': avenues for synergies between two approaches
    2016 (English)In: Interdisciplinary Environmental Review, ISSN 1521-0227, E-ISSN 2042-6992, Vol. 17, no 1, 1-19 p.Article in journal (Refereed) Published
    Abstract [en]

    Based on a literature review of over 160 journal articles and books, this article examines the ecosystem management and environmental governance approaches, and looks for common topics and integrated research agendas. While scientific articles on environmental governance stem primarily from social science research, the ecosystem management approach is more natural science-oriented. A review of journal articles from the ISI Web of Knowledge (Web of Science) reveals that the two research communities hardly interact. The paper discusses two thematic linkages between the two approaches: the debates dealing with the scale and level of environmental policy; and the discussions surrounding multi-stakeholder participation. Moreover, the article identifies areas with a high potential for the establishment of common ground, such as the current discussion on science-policy interfaces. We argue for more interaction, claim that the two research approaches can learn from each other, and discuss the potential for the development of interdisciplinary research agendas.

    Place, publisher, year, edition, pages
    Bucks: InderScience Publishers, 2016
    Keyword
    environmental governance; ecosystem management; environmental policy scale; environmental policy level; multi-stakeholder participation; science-policy interfaces; multiple stakeholders; literature review; interdisciplinary research.
    National Category
    Social Sciences Interdisciplinary Environmental Management Human Aspects of ICT Information Systems, Social aspects
    Identifiers
    urn:nbn:se:liu:diva-133973 (URN)10.1504/IER.2016.074871 (DOI)
    Available from: 2017-01-17 Created: 2017-01-17 Last updated: 2017-01-17Bibliographically approved
    2. Marine Governance in the Baltic Sea: Current Trends of Europeanization and Regionalization
    Open this publication in new window or tab >>Marine Governance in the Baltic Sea: Current Trends of Europeanization and Regionalization
    2015 (English)In: Governing Europe's Marine Environment: Europeanization of Regional Seas or Regionalization of EU Policies? / [ed] Michael Gilek and Kristine Kern, Farnham: Ashgate, 2015, 163-181 p.Chapter in book (Other academic)
    Place, publisher, year, edition, pages
    Farnham: Ashgate, 2015
    Keyword
    Miljövetenskapliga studier; Östersjö- och Östeuropaforskning
    National Category
    Environmental Sciences
    Identifiers
    urn:nbn:se:liu:diva-133975 (URN)9781409447276 (ISBN)
    Available from: 2017-01-17 Created: 2017-01-17 Last updated: 2017-01-17Bibliographically approved
  • Public defence: 2017-02-17 13:15 Visionen, Hus B, Linköping
    Rankin, Amy
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.
    Rankin, Amy
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.
    Making Sense of Adaptations: Resilience in High-Risk Work2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    To cope with variations, disturbances, and unexpected events in complex socio-technical systems people are required to continuously adapt to the changing environment, sometimes in novel and innovative ways. This thesis investigates adaptive performance in complex work settings across domains, with a focus on examining what enables and disables successful adaptations, and how contextual factors shape performance. Examples of adaptive performance studies include a crisis command team dealing with the loss of key personnel, a crew coping with unreliable system feedback in the cockpit, and a nursing team managing an overload of patients. The two main contributions of this thesis is the analysis of cases of people coping with variations and disturbances, and the development of conceptual models to report findings, structure cases, and make sense of sharp-end adaptations in complex work settings. The findings emphasise that adaptive performance outside procedures and textbook scenarios at the sharp end is a critical ability to cope with variation and unexpected events. However, the results also show that adaptations may come at the cost of new vulnerabilities and system brittleness. Analysing adaptive performance in everyday events informs safety management by making visible limitations and possibilities of system design, organisational structures, procedures, and training.

    List of papers
    1. Sensemaking following surprise in the cockpit-a re-framing problem
    Open this publication in new window or tab >>Sensemaking following surprise in the cockpit-a re-framing problem
    2016 (English)In: Cognition, Technology & Work, ISSN 1435-5558, E-ISSN 1435-5566, Vol. 18, no 4, 623-642 p.Article in journal (Refereed) Published
    Abstract [en]

    Re-framing is the process by which a person "fills the gap" between what is expected and what has been observed, that is, to try and make sense of what is going on following a surprise. It is an active and adaptive process guided by expectations, which are based on knowledge and experience. In this article, surprise situations in cockpit operations are examined by investigating the re-framing process. The results show difficulties that pilots have in re-framing following surprise, including the identification of subtle cues and managing uncertainties regarding automated systems, coping with multiple goals, tasks and narrow time frames and identifying an appropriate action. A crew-aircraft sensemaking model is presented, outlining core concepts of re-framing processes and sensemaking activities. Based on the findings, three critical areas are identified that deserve further attention to improve pilot abilities to cope with unexpected events; (1) identification of what enables and obstructs re-framing, (2) training to build frames and develop re-framing strategies and (3) control strategies as part of the re-framing process.

    Keyword
    Sensemaking; Surprise; Cockpit operations; Re-framing; Training
    National Category
    Production Engineering, Human Work Science and Ergonomics
    Identifiers
    urn:nbn:se:liu:diva-132839 (URN)10.1007/s10111-016-0390-2 (DOI)000386502500001 ()
    Note

    Funding Agencies|Man4Gen

    Available from: 2016-12-06 Created: 2016-11-30 Last updated: 2017-01-12
    2. Resilience in Everyday Operations: A Framework for Analysing Adaptations in High Risk Work
    Open this publication in new window or tab >>Resilience in Everyday Operations: A Framework for Analysing Adaptations in High Risk Work
    Show others...
    2014 (English)In: Journal of Cognitive Engineering and Decision Making, ISSN 1555-3434, Vol. 8, no 1, 78-97 p.Article in journal (Refereed) Published
    Abstract [en]

    Managing complexity and uncertainty in high risk, socio-technical, systems requires people to continuously adapt. Designing resilient systems that support adaptive behaviour requires a deepened understanding of the context in which the adaptations take place, enablers for successful adaptations and their affect the overall system. Also, it requires a focus on how people actually perform, not how they are presumed to perform according to textbook situations. We propose a framework to analyse adaptive behaviour in everyday situations where systems are working near the margins of safety. The examples that underlie the framework are derived from nine focus groups with representatives working with safety related issues in different work domains, including health care, nuclear, transportation and emergency services. Further, the variety space diagram is developed as a means to illustrate how system variability, disturbances and constraints affect work performance.

    Place, publisher, year, edition, pages
    Sage Publications, 2014
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-91989 (URN)10.1177/1555343413498753 (DOI)2-s2.0-84893856937 (ScopusID)
    Available from: 2013-05-07 Created: 2013-05-07 Last updated: 2017-01-12Bibliographically approved
    3. A case study of factor influencing role improvisation in crisis response teams
    Open this publication in new window or tab >>A case study of factor influencing role improvisation in crisis response teams
    2013 (English)In: Cognition, Technology & Work, ISSN 1435-5558, E-ISSN 1435-5566, Vol. 15, no 1, 79-93 p.Article in journal (Refereed) Published
    Abstract [en]

    Common characteristics of crisis situations are ambiguous and unplanned for events. The need for improvised roles can therefore be an imperative factor for the success of an operation. The aim of this study is to deepen the understanding of the processes taking place during improvised work ‘‘as it happens’’. A case study of a crisis management team at work is presented and provides an in-depth analysis of the information and communication flow of persons acting in improvised roles, including con- textual factors influencing the task at hand. The analysis suggests that three main factors lay behind decreased per- formance by the team when some of its members were forced to take on roles for which they lacked professional training; lack of language skills, lack of domain knowledge and insufficient organizational structure of the tasks. Based on the observations from this case study, we suggest three ways of improving a team’s performance and hence resil- ience when forced to improvise due to lack of personnel in one or more required competence areas. These are training to take on the responsibility for tasks or roles outside ones professional area of specialization, developing formal routines for changes in roles and tasks and developing and using tools and routines for information sharing.

    Place, publisher, year, edition, pages
    Springer, 2013
    Keyword
    Role improvisation, Crisis management, Resilience engineering, Organizational improvisation, Episode analysis
    National Category
    Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-80311 (URN)10.1007/s10111-011-0186-3 (DOI)000313737400010 ()
    Available from: 2012-08-23 Created: 2012-08-23 Last updated: 2017-01-12
    4. A framework for learning from adaptive performance
    Open this publication in new window or tab >>A framework for learning from adaptive performance
    2014 (English)In: Resilience engineering in practice. Vol. 2: Becoming resilient / [ed] Christopher P. Nemeth, Erik Hollnagel, Surrey: Ashgate, 2014, 2, 79-95 p.Chapter in book (Other academic)
    Place, publisher, year, edition, pages
    Surrey: Ashgate, 2014 Edition: 2
    Keyword
    Political Science, Labor & Industrial Relations, Psychology, Industrial & Organizational Psychology, Technology & Engineering, Technical Writing
    National Category
    Political Science Psychology
    Identifiers
    urn:nbn:se:liu:diva-133849 (URN)9781472425157 (ISBN)
    Available from: 2017-01-12 Created: 2017-01-12 Last updated: 2017-01-12Bibliographically approved
  • Public defence: 2017-02-23 13:15 John von Neumann, Hus B, Linköping
    Haque, Muhammad Fahim Ul
    Linköping University, Department of Electrical Engineering. Linköping University, Faculty of Science & Engineering.
    Haque, Muhammad Fahim Ul
    Linköping University, Department of Electrical Engineering. Linköping University, Faculty of Science & Engineering.
    Pulse-Width Modulated RF Transmitters2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The market for wireless portable devices has grown signicantly over the recent years.Wireless devices with ever-increased functionality require high rate data transmissionand reduced costs. High data rate is achieved through communication standards such asLTE and WLAN, which generate signals with high peak-to-average-power ratio (PAPR),hence requiring a power amplier (PA) that can handle a large dynamic range signal. Tokeep the costs low, modern CMOS processes allow the integration of the digital, analogand radio functions on to a single chip. However, the design of PAs with large dynamicrange and high eciency is challenging due to the low voltage headroom.

    To prolong the battery life, the PAs have to be power-ecient as they consume a sizablepercentage of the total power. For LTE and WLAN, traditional transmitters operatethe PA at back-o power, below their peak efficiency, whereas pulse-width modulation(PWM) transmitters use the PA at their peak power, resulting in a higher efficiency.PWM transmitters can use both linear and SMPAs where the latter are more power efficient and easy to implement in nanometer CMOS. The PWM transmitters have a higher efficiency but suffer from image and aliasing distortion, resulting in a lower dynamic range,amplitude and phase resolution.

    This thesis studies several new transmitter architectures to improve the dynamicrange, amplitude and phase resolution of PWM transmitters with relaxed filtering requirements.The architectures are suited for fully integrated CMOS solutions, in particular forportable applications.

    The first transmitter (MAF-PWMT) eliminates aliasing and image distortions whileallowing the use of SMPAs by combining RF-PWM and band-limited PWM. The transmittercan be implemented using all-digital techniques and exhibits an improved linearity and spectral performance. The approach is validated using a Class-D PA based transmitter where an improvement of 10.2 dB in the dynamic range compared to a PWM transmitter for a 1.4 MHz of LTE signal is achieved.

    The second transmitter (AC-PWMT) compensates for aliasing distortion by combining PWM and outphasing. It can be used with switch-mode PAs (SMPAs) or linear PAs at peak power. The proposed transmitter shows better linearity, improved spectral performanceand increased dynamic range as it does not suffer from AM-AM distortion of the PAs and aliasing distortion due to digital PWM. The idea is validated using push-pull PAs and the proposed transmitter shows an improvement of 9 dB in the dynamic rangeas compared to a PWM transmitter using digital pulse-width modulation for a 1.4 MHzLTE signal.

    The third transmitter (MD-PWMT) is an all-digital implementation of the second transmitter. The PWM is implemented using a Field Programmable Gate Array(FPGA) core, and outphasing is implemented as pulse-position modulation using FPGA transceivers, which drive two class-D PAs. The digital implementation offers the exibility to adapt the transmitter for multi-standard and multi-band signals. From the measurement results, an improvement of 5 dB in the dynamic range is observed as compared to an all-digital PWM transmitter for a 1.4 MHz LTE signal.

    The fourth transmitter (EP-PWMT) improves the phase linearity of an all-digital PWM transmitter using PWM and asymmetric outphasing. The transmitter uses PWM to encode the amplitude, and outphasing for enhanced phase control thus doubling the phase resolution. The measurement setup uses Class-D PAs to amplify a 1.4 MHz LTEup-link signal. An improvement of 2.8 dB in the adjacent channel leakage ratio is observed whereas the EVM is reduced by 3.3 % as compared to an all-digital PWM transmitter.

    The fifth transmitter (CRF-ML-PWMT) combines multilevel and RF-PWM, whereas the sixth transmitter (CRF-MP-PMWT) combines multiphase PWM and RF-PWM. Both transmitters have smaller chip area as compared to the conventional multiphase and multilevel PWM transmitters, as a combiner is not required. The proposed transmitters also show better dynamic range and improved amplitude resolution as compared to conventional RF-PWM transmitters.

    The solutions presented in this thesis aims to enhance the performance and simplify the digital implementation of PWM-based RF transmitters.

    List of papers
    1. Combined RF and Multilevel PWM Switch Mode Power Amplifier
    Open this publication in new window or tab >>Combined RF and Multilevel PWM Switch Mode Power Amplifier
    2013 (English)In: Norchip, IEEE , 2013, 1-4 p.Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel power amplifier (PA) architecture based on the combination of radio frequency pulse width modulation (RFPWM) and multilevel PWM. The architecture provides better dynamic range at high carrier frequency compared to RFPWM. The benefits of this architecture over multilevel PWM are that it only requires a single PA and no combiner. The average efficiency for an 802.11g baseband signal is better than multilevel PWM. Our results also shows that the proposed technique exhibit a constant dynamic range at carrier frequency of 3, 4 and 5 GHz, in contrast to RFPWM which shows a decrease in dynamic range for increase in carrier frequency.

    Place, publisher, year, edition, pages
    IEEE, 2013
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-102929 (URN)10.1109/NORCHIP.2013.6702010 (DOI)978-147991647-4 (ISBN)
    Conference
    NORCHIP 2013; Vilnius; Lithuania
    Available from: 2014-01-08 Created: 2014-01-08 Last updated: 2017-01-18
    2. Combined RF and Multiphase PWM Transmitter
    Open this publication in new window or tab >>Combined RF and Multiphase PWM Transmitter
    2015 (English)In: 2015 European Conference on Circuit Theory and Design (ECCTD), IEEE , 2015, 264-267 p.Conference paper (Refereed)
    Abstract [en]

    This paper presents two novel transmitter architectures based on the combination of radio-frequency pulse-width modulation and multiphase pulse-width modulation. The proposed transmitter architectures provide good amplitude resolution and large dynamic range at high carrier frequency, which is problematic with existing radio-frequency pulse-width modulation based transmitters. They also have better power efficiency and smaller chip area compared to multiphase pulse-width modulation based transmitters.

    Place, publisher, year, edition, pages
    IEEE, 2015
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-122703 (URN)10.1109/ECCTD.2015.7299999 (DOI)000380498200001 ()978-1-4799-9877-7 (ISBN)
    Conference
    2015 European Conference on Circuit Theory and Design (ECCTD), Trondheim, Norway, August 24-26, 2015
    Available from: 2015-11-16 Created: 2015-11-16 Last updated: 2017-01-18Bibliographically approved