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  • 101701.
    Ziegenbein, Tim
    Linköping University, Department of Computer and Information Science, Human-Centered systems.
    Designing HTML5 2D platformer for web cam based motion games2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Movement interaction in games has over the last years been a main subject in the area of game design and recent motion based interaction systems provide many improvements over earlier systems. Research has proven that motion based games provide several benefits over general games, they increase the players’ engagement level and may induce both mental and physical health benefits. Still, not much research has been conducted in the area of motion based platform games, even though the platform game genre is one of the most popular game genres. In this thesis, a case study is conducted in order to extract design principles and guidelines applicable for motion based platform games. The study includes implementation of a browser-based 2D platform game that uses the web camera to provide motion based interaction. One of the conclusions in this study indicates that many game features from ordinary platform games only require minor modifications to be applicable for motion based platform games.

  • 101702.
    Ziegert, Kristina
    Linköping University, Department of Medicine and Care, Nursing Science. Linköping University, Faculty of Health Sciences.
    Everyday life among next of kin of haemodialysis patients2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Everyday life can be complex when next of kin of haemodialysis patients are preoccupied with taking care of the patient and his/her health. which implies the difficulties and requirements needed. The general aim of this thesis was to explore and describe everyday life among next of kin of haemodialysis patients with focus on the life situation, health, time and professional support. Two perspectives of the thesis was applied: a holistic perspective on the everyday life of next of haemodialysis patient and a social perspective with focus on human communication and understanding of next of kin's experience of everyday life. A qualitative descriptive and explorative design. comprising a phenomenographic and content analysis was used in Studies I-IV. The data collected in the studies consisted of interviews with next of kin to haemodialysis patient and analysis of professional support for next of kin to chronic haemodialysis patients in nursing documentation from two hospitals in Sweden.

    The experience of time in everyday life among next of kin of haemodialysis patients demonstrated that time for them is minimised and life space contracted. Next of kin experienced ambivalence towards their own health, especially in cases of patients' spouses When next of kin of haemodialysis patient's became involved in the patients' care, they experienced arduousness in relation to their own health as well as less uninterrupted time for themselves in everyday life. and their life situation was characterised by confinement and social isolation. They were aware of the prognosis of renal disease and the fact that haemodialysis is a life-sustaining treatment, which forced them to live for the moment. The everyday life among the next of kin changed when the family became involved in the care. which in turn lead to a changed life situation and restrictions in everyday life. Lack of knowledge in nursing documentation of professional support revealed necessity of the readiness of next of kin. It is therefore important to be familiar with this in the nursing process. especially when the patient and their next of kin need support and attention in everyday life.

    List of papers
    1. Conceptions of life situation among next-of-kin of haemodialysis patients
    Open this publication in new window or tab >>Conceptions of life situation among next-of-kin of haemodialysis patients
    2001 (English)In: Journal of Nursing Management, ISSN 0966-0429, E-ISSN 1365-2834, Vol. 9, no 4, p. 231-239Article in journal (Refereed) Published
    Abstract [en]

    The presence of renal disease in a family is a strain on both the patient and the next-of-kin, affecting their life situations. Surprisingly, few studies dealing with the ways that the next-of-kin experience their situation are available. The aim of this study was to describe how the next-of-kin of haemodialysis patients conceive their life situation. Data were collected by interviewing 12 people who live with someone with dialysis-treated renal disease and analysed according to a qualitative method inspired by the phenomenographic approach. Six description categories of how the subjects construed their life situation emerged: a feeling of confinement; a feeling of social isolation; a feeling that the way of life has changed; a feeling of security in life; a feeling of a threatening future; and promoting health. The next-of-kin generally expressed a large degree of commitment to and concern for the sick person. In spite of their life situation having been dramatically changed, the next-of-kin described an ability to adapt. With the help of society the feelings of confinement and social isolation can be dispersed, enabling the next-of-kin to promote the health of the sick person. A suggestion for further research is to study what adaptation strategies next-of-kin use in their life situation.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-27214 (URN)10.1046/j.1365-2834.2001.00233.x (DOI)11863 (Local ID)11863 (Archive number)11863 (OAI)
    Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13Bibliographically approved
    2. Health in everyday life among spouses of haemodialysis patients: a content analysis
    Open this publication in new window or tab >>Health in everyday life among spouses of haemodialysis patients: a content analysis
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Despite the fact that haemodialysis requires that spouses support and assist their partner during the treatment period, little attention has been focused on their health. The aim of this study was to explore experiences of health in everyday life in spouses of haemodialysis patients. The study had an explorative and descriptive design based on content analysis. Thirteen participants were interviewed in their home without the presence of the patient. The results show that arduousness was experienced when that spouses' everyday life was taken up by caring for the patient at the expense of his/her own health. Spouses exhibited stamina and neglected their own health when focusing on the patient and minimising their own condition. Independence in everyday life revealed that spouses who cared about themselves and looked after their own health experienced relaxation and happiness, which protected their health. Clinical interventions should include an assessment of the spouses' health and everyday life in order to plan the care to ensure that it is directed towards increasing their independence. Future study could be done with a grounded theory method on this population to determine relationships between elements of the social process of arduousness, stamina and/or independence in the context ofhaving a spouse experiencing haemodialysis.

    Keywords
    health experience, everyday life, spouses, haemodialysis patients, content analysis
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-81931 (URN)
    Available from: 2012-09-25 Created: 2012-09-25 Last updated: 2012-09-25Bibliographically approved
    3. Time in everyday life as experienced by next of kin of haemodialysis patients
    Open this publication in new window or tab >>Time in everyday life as experienced by next of kin of haemodialysis patients
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Aim The aim of this study was to explore the content of time in everyday life as experienced by the next of kin of haemodialysis patients.

    Background Chronic renal disease often requires haemodialysis which is a time-consuming treatment that necessitates careful planning of everyday life and involves next of kin to a large degree. Next of kin's time can be severely restricted when his/her life is devoted to the needs of the haemodialysis patient.

    Method This study used explorative and descriptive design with a qualitative content analysis approach. Twenty next of kin selected purposive with the criterion of having at least one year of experience as a next of kin of a patient on haemodialysis.

    Results Analysis of data from the interviews revealed experiences of time in everyday lives of the next of kin of haemodialysis patients. Their experiences were reflected in the concepts fragmented time, vacuous time and uninterrupted time.

    Conclusion The experience of time in the everyday lives of next of kin of haemodialysis patients demonstrated that time for themselves was minimised and that common life space contracted. The next of kin were also aware of the prognosis of renal disease and the fact that haemodialysis was a life-sustaining treatment, which forced them to live in the present. They afforded wellness when they experienced a break from everyday live and could use their time for their own needs. Attention should be focused on time in the nurse's assessment of the next of kin's everyday life and whether or not next of kin have sufficient time required for the patient's care. There is need for further research that focuses on a generalisation of the fmdings by means of the development of instruments that can contribute assessment of time in everyday life among next of kin of chronically ill patients.

    Keywords
    Time, everyday life, next of kin, haemodialysis patients, content analysis
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-81932 (URN)
    Available from: 2012-09-25 Created: 2012-09-25 Last updated: 2012-09-25Bibliographically approved
    4. Professional support for next of kin of patients receiving chronic haemodialysis treatment: a content analysis study of nursing documentation
    Open this publication in new window or tab >>Professional support for next of kin of patients receiving chronic haemodialysis treatment: a content analysis study of nursing documentation
    2007 (English)In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 16, no 2, p. 353-361Article in journal (Refereed) Published
    Abstract [en]

    Aim and objectives.  The aim of this study was to examine the content of nursing documentation with a focus on professional support for next of kin (NoK) of patients receiving chronic haemodialysis treatment.

    Background.  Professional support in nursing focuses on promotion, maintenance and restoration of health and prevention of illness.

    Design.  The study had a descriptive design and qualitative content analysis was used to search for themes based on descriptions contained in the collected nursing documentation.

    Methods.  The total number of nursing records of patients receiving chronic haemodialysis treatment (n = 50) for the 5-year period 1998–2002 was included. All nursing documentation was systematic in accordance with the VIPS-documentation model.

    Results.  The professional support could be described within the framework of three themes: to explore NoK's supportive resources, to enable NoK’ readiness in caring for the patient and to co-operate with NoK in the care of the patient in the home, captured by the core theme which described the professional support as a continuous process.

    Conclusions.  Next of kin are a supportive resource in the nursing care of patients receiving chronic haemodialysis treatment and professional support for NoK focuses on planning their participation in the care of patients in the home.

    Relevance to clinical practice.  Professional support for NoK should be documented in family focused nursing diagnoses, which would make it possible to search for different types of support. Future research might explore nurses’ or NoK's views on carer support.

    Keywords
    Content analysis, Haemodialysis, Next of kin, Nursing, Nursing documentation, Professional support
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-49996 (URN)10.1111/j.1365-2702.2006.01597.x (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12Bibliographically approved
  • 101703.
    Ziegert, Kristina
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    Omvårdnad av patientmed diabetes mellitus2002In: Omvårdnad vid långvariga sjukdomstillstånd : fallbeskrivningar / [ed] Ulrike Kylberg, Evy Lidell, Lund: Studentlitteratur , 2002, 1, p. 123-138Chapter in book (Other academic)
    Abstract [sv]

    Att vårda personer med långvariga sjukdomstillstånd utgör en betydande del av sjuksköterskors omvårdnadsarbete. Genom mångsidiga omvårdnadsinsatser får patienter och anhöriga ett anpassat stöd så att behov och resurser förblir i god balans. Detta är en viktig aspekt av omvårdnad i en tid med stark betoning på ansvar för egenvård. I denna bok vill författarna delge läsaren sina kunskaper och erfarenheter av hur olika omvårdnaden vid långvariga sjukdomstillstånd kan gestalta sig

  • 101704.
    Ziegert, Kristina
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    Å vaere pårörende till mennesker med kronisk nyresvikt og hemodialysebehandling2002In: Bære hverandres byrder : pårørende i sykepleien / [ed] Berit Støre Brinchmann; Stinne Glasdam, Bergen: Fagbokforlaget , 2002, p. 127-139Chapter in book (Other academic)
  • 101705.
    Ziegert, Kristina
    et al.
    Linköping University, Department of Medicine and Care, Nursing Science. Linköping University, Faculty of Health Sciences.
    Fridlund, Bengt
    Linköping University, Department of Medicine and Care, Nursing Science. Linköping University, Faculty of Health Sciences.
    Conceptions of life situation among next-of-kin of haemodialysis patients2001In: Journal of Nursing Management, ISSN 0966-0429, E-ISSN 1365-2834, Vol. 9, no 4, p. 231-239Article in journal (Refereed)
    Abstract [en]

    The presence of renal disease in a family is a strain on both the patient and the next-of-kin, affecting their life situations. Surprisingly, few studies dealing with the ways that the next-of-kin experience their situation are available. The aim of this study was to describe how the next-of-kin of haemodialysis patients conceive their life situation. Data were collected by interviewing 12 people who live with someone with dialysis-treated renal disease and analysed according to a qualitative method inspired by the phenomenographic approach. Six description categories of how the subjects construed their life situation emerged: a feeling of confinement; a feeling of social isolation; a feeling that the way of life has changed; a feeling of security in life; a feeling of a threatening future; and promoting health. The next-of-kin generally expressed a large degree of commitment to and concern for the sick person. In spite of their life situation having been dramatically changed, the next-of-kin described an ability to adapt. With the help of society the feelings of confinement and social isolation can be dispersed, enabling the next-of-kin to promote the health of the sick person. A suggestion for further research is to study what adaptation strategies next-of-kin use in their life situation.

  • 101706.
    Ziegert, Kristina
    et al.
    Linköping University, Department of Medicine and Health Sciences, Nursing Science. Linköping University, Faculty of Health Sciences.
    Fridlund, Bengt
    Halmstad University.
    Lidell , Evy
    Halmstad University.
    "Time for dialysis as time to live": Experiences of time in everyday life of the Swedish next of kin of hemodialysis patients2009In: NURSING and HEALTH SCIENCES, ISSN 1441-0745 , Vol. 11, no 1, p. 45-50Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to explore the content of time in everyday life as experienced by the next of kin of patients on hemodialysis in Sweden. Chronic renal disease often requires hemodialysis, which is a time-consuming treatment that makes it necessary to carefully plan everyday life and involves the next of kin to a large degree. This study used a descriptive design with a content analysis approach. The analysis of the data from the twenty interviews revealed the experiences of time in the everyday lives of the next of kin of a patient on hemodialysis. The content of time in everyday life can be described as follows: fragmented time, vacuous time, and uninterrupted time. The findings show how everyday life time for the next of kin is minimized and that the common life space is contracted. The next of kin must be provided with supervision in order to provide them with more of their own time in everyday life, which can benefit their health.

  • 101707.
    Ziegert, Kristina
    et al.
    Linköping University, Department of Medicine and Care, Nursing Science. Linköping University, Faculty of Health Sciences.
    Fridlund, Bengt
    School of Social and Health Sciences, Halmstad University, Halmstad and Department of Health Sciences, Lund University, Lund, Sweden.
    Lidell, Evy
    School of Social and Health Sciences, Halmstad University, Halmstad.
    Health in everyday life among spouses of haemodialysis patients: a content analysisManuscript (preprint) (Other academic)
    Abstract [en]

    Despite the fact that haemodialysis requires that spouses support and assist their partner during the treatment period, little attention has been focused on their health. The aim of this study was to explore experiences of health in everyday life in spouses of haemodialysis patients. The study had an explorative and descriptive design based on content analysis. Thirteen participants were interviewed in their home without the presence of the patient. The results show that arduousness was experienced when that spouses' everyday life was taken up by caring for the patient at the expense of his/her own health. Spouses exhibited stamina and neglected their own health when focusing on the patient and minimising their own condition. Independence in everyday life revealed that spouses who cared about themselves and looked after their own health experienced relaxation and happiness, which protected their health. Clinical interventions should include an assessment of the spouses' health and everyday life in order to plan the care to ensure that it is directed towards increasing their independence. Future study could be done with a grounded theory method on this population to determine relationships between elements of the social process of arduousness, stamina and/or independence in the context ofhaving a spouse experiencing haemodialysis.

  • 101708.
    Ziegert, Kristina
    et al.
    Linköping University, Department of Medical and Health Sciences, Nursing Science. Linköping University, Faculty of Health Sciences.
    Fridlund, Bengt
    School of Health Sciences and Social Work, Växjö University, Växjö, Sweden.
    Lidell, Evy
    School of Social and Health Sciences, Halmstad University, Halmstad, Sweden.
    Professional support for next of kin of patients receiving chronic haemodialysis treatment: a content analysis study of nursing documentation2007In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 16, no 2, p. 353-361Article in journal (Refereed)
    Abstract [en]

    Aim and objectives.  The aim of this study was to examine the content of nursing documentation with a focus on professional support for next of kin (NoK) of patients receiving chronic haemodialysis treatment.

    Background.  Professional support in nursing focuses on promotion, maintenance and restoration of health and prevention of illness.

    Design.  The study had a descriptive design and qualitative content analysis was used to search for themes based on descriptions contained in the collected nursing documentation.

    Methods.  The total number of nursing records of patients receiving chronic haemodialysis treatment (n = 50) for the 5-year period 1998–2002 was included. All nursing documentation was systematic in accordance with the VIPS-documentation model.

    Results.  The professional support could be described within the framework of three themes: to explore NoK's supportive resources, to enable NoK’ readiness in caring for the patient and to co-operate with NoK in the care of the patient in the home, captured by the core theme which described the professional support as a continuous process.

    Conclusions.  Next of kin are a supportive resource in the nursing care of patients receiving chronic haemodialysis treatment and professional support for NoK focuses on planning their participation in the care of patients in the home.

    Relevance to clinical practice.  Professional support for NoK should be documented in family focused nursing diagnoses, which would make it possible to search for different types of support. Future research might explore nurses’ or NoK's views on carer support.

  • 101709.
    Ziegert, Kristina
    et al.
    Linköping University, Department of Medicine and Care, Nursing Science. Linköping University, Faculty of Health Sciences.
    Fridlund, Bengt
    School of Social and Health Sciences, Halmstad University, Halmstad and Department of Health Sciences, Lund University, Lund, Sweden.
    Lidell, Evy
    School of Social and Health Sciences, Halmstad University, Halmstad, Sweden.
    Time in everyday life as experienced by next of kin of haemodialysis patientsManuscript (preprint) (Other academic)
    Abstract [en]

    Aim The aim of this study was to explore the content of time in everyday life as experienced by the next of kin of haemodialysis patients.

    Background Chronic renal disease often requires haemodialysis which is a time-consuming treatment that necessitates careful planning of everyday life and involves next of kin to a large degree. Next of kin's time can be severely restricted when his/her life is devoted to the needs of the haemodialysis patient.

    Method This study used explorative and descriptive design with a qualitative content analysis approach. Twenty next of kin selected purposive with the criterion of having at least one year of experience as a next of kin of a patient on haemodialysis.

    Results Analysis of data from the interviews revealed experiences of time in everyday lives of the next of kin of haemodialysis patients. Their experiences were reflected in the concepts fragmented time, vacuous time and uninterrupted time.

    Conclusion The experience of time in the everyday lives of next of kin of haemodialysis patients demonstrated that time for themselves was minimised and that common life space contracted. The next of kin were also aware of the prognosis of renal disease and the fact that haemodialysis was a life-sustaining treatment, which forced them to live in the present. They afforded wellness when they experienced a break from everyday live and could use their time for their own needs. Attention should be focused on time in the nurse's assessment of the next of kin's everyday life and whether or not next of kin have sufficient time required for the patient's care. There is need for further research that focuses on a generalisation of the fmdings by means of the development of instruments that can contribute assessment of time in everyday life among next of kin of chronically ill patients.

  • 101710.
    Ziegert, Kristina
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    Högstedt, B
    Fridlund, B
    Lidell, E
    Time distribution factors of hospital and home care among chronic haemodialysis patients2004In: EDTNA-ERCA Journal, ISSN 1019-083X, Vol. 30, no 1, p. 19-22Article in journal (Refereed)
    Abstract [en]

    Today, many studies are available that focus on haemodialysis, however studies on the time distribution factor involved are lacking. It is therefore important to study the distribution of time, taking into account outpatient care, inpatient care and home care. The aim of the study was to chart over a five-year period, the time distribution factors of hospital care and home care among chronic haemodialysis patients. The design of the study was descriptive, and the data material was drawn from a patient register (N=61). The data analysis was performed by means of both descriptive and inferential statistics.

  • 101711.
    Ziegler, Gernot
    Linköping University, Department of Science and Technology.
    MPEG Z/Alpha and high-resolution MPEG2003Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    The progression of technical development has yielded practicable camera systems for the acquisition of so called depth maps, images with depth information.

    Images and movies with depth information open the door for new types of applications in the area of computer graphics and vision. That implies that they will need to be processed in all increasing volumes.

    Increased depth image processing puts forth the demand for a standardized data format for the exchange of image data with depth information, both still and animated. Software to convert acquired depth data to such videoformats is highly necessary.

    This diploma thesis sheds light on many of the issues that come with this new task group. It spans from data acquisition over readily available software for the data encoding to possible future applications.

    Further, a software architecture fulfilling all of the mentioned demands is presented.

    The encoder is comprised of a collection of UNIX programs that generate MPEG Z/Alpha, an MPEG2 based video format. MPEG Z/Alpha contains beside MPEG2's standard data streams one extra data stream to store image depth information (and transparency).

    The decoder suite, called TexMPEG, is a C library for the in-memory decompression of MPEG Z/Alpha. Much effort has been put into video decoder parallelization, and TexMPEG is now capable of decoding multiple video streams, not only in parallel internally, but also with inherent frame synchronization between parallely decoded MPEG videos.

  • 101712.
    Ziegler, Magnus
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Improving Assessments of Hemodynamics and Vascular Disease2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Blood vessels are more than simple pipes, passively enabling blood to pass through them. Their form and function are dynamic, changing with both aging and disease. This process involves a feedback loop wherein changes to the shape of a blood vessel affect the hemodynamics, causing yet more structural adaptation. This feedback loop is driven in part by the hemodynamic forces generated by the blood flow, and the distribution and strength of these forces appear to play a role in the initiation, progression, severity, and the outcome of vascular diseases.

    Magnetic Resonance Imaging (MRI) offers a unique platform for investigating both the form and function of the vascular system. The form of the vascular system can be examined using MR-based angiography, to generate detailed geometric analyses, or through quantitative techniques for measuring the composition of the vessel wall and atherosclerotic plaques. To complement these analyses, 4D Flow MRI can be used to quantify the functional aspect of the vascular system, by generating a full time-resolved three-dimensional velocity field that represents the blood flow.

    This thesis aims to develop and evaluate new methods for assessing vascular disease using novel hemodynamic markers generated from 4D Flow MRI and quantitative MRI data towards the larger goal of a more comprehensive non-invasive examination oriented towards vascular disease. In Paper I, we developed and evaluated techniques to quantify flow stasis in abdominal aortic aneurysms to measure this under-explored aspect of aneurysmal hemodynamics. In Paper II, the distribution and intensity of turbulence in the aorta was quantified in both younger and older men to understand how aging changes this aspect of hemodynamics. A method to quantify the stresses generated by turbulence that act on the vessel wall was developed and evaluated using simulated flow data in Paper III, and in Paper V this method was utilized to examine the wall stresses of the carotid artery. The hemodynamics of vascular disease cannot be uncoupled from the anatomical changes the vessel wall undergoes, and therefore Paper IV developed and evaluated a semi-automatic method for quantifying several aspects of vessel wall composition. These developments, taken together, help generate more valuable information from imaging data, and can be pooled together with other methods to form a more comprehensive non-invasive examination for vascular disease.

    List of papers
    1. Visualizing and quantifying flow stasis in abdominal aortic aneurysms in men using 4D flow MRI
    Open this publication in new window or tab >>Visualizing and quantifying flow stasis in abdominal aortic aneurysms in men using 4D flow MRI
    Show others...
    2019 (English)In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 57, p. 103-110Article in journal (Refereed) Published
    Abstract [en]

    Purpose: To examine methods for visualizing and quantifying flow stasis in abdominal aortic aneurysms (AAA) using 4D Flow MRI. Methods: Three methods were investigated: conventional volumetric residence time (VRT), mean velocity analysis (MVA), and particle travel distance analysis (TDA). First, ideal 4D Flow MRI data was generated using numerical simulations and used as a platform to explore the effects of noise and background phase-offset errors, both of which are common 4D Flow MRI artifacts. Error-free results were compared to noise or offset affected results using linear regression. Subsequently, 4D Flow MRI data for thirteen (13) subjects with AAA was acquired and used to compare the stasis quantification methods against conventional flow visualization. Results: VRT (R-2 = 0.69) was more sensitive to noise than MVA (R-2 = 0.98) and TDA (R-2 = 0.99) at typical noncontrast signal-to-noise ratio levels (SNR = 20). VRT (R-2 = 0.14) was more sensitive to background phase-offsets than MVA (R-2 = 0.99) and TDA (R-2 = 0.96) when considering a 95% effective background phase-offset correction. Qualitatively, TDA outperformed MVA (Wilcoxon p amp;lt; 0.005, mean score improvement 1.6/5), and had good agreement (median score 4/5) with flow visualizations. Conclusion: Flow stasis can be quantitatively assessed using 4D Flow MRI. While conventional residence time calculations fail due to error accumulation as a result of imperfect measured velocity fields, methods that do not require lengthy particle tracking perform better. MVA and TDA are less sensitive to measurement errors, and TDA generates results most similar to those obtained using conventional flow visualization.

    Place, publisher, year, edition, pages
    ELSEVIER SCIENCE INC, 2019
    Keywords
    Abdominal aortic aneurysm; Hemodynamics; 4D flow MRI; Flow stasis
    National Category
    Medical Laboratory and Measurements Technologies
    Identifiers
    urn:nbn:se:liu:diva-154524 (URN)10.1016/j.mri.2018.11.003 (DOI)000458096100012 ()30445146 (PubMedID)
    Available from: 2019-02-20 Created: 2019-02-20 Last updated: 2020-01-14
    2. Age-Related Vascular Changes Affect Turbulence in Aortic Blood Flow
    Open this publication in new window or tab >>Age-Related Vascular Changes Affect Turbulence in Aortic Blood Flow
    Show others...
    2018 (English)In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 9, article id 36Article in journal (Refereed) Published
    Abstract [en]

    Turbulent blood flow is implicated in the pathogenesis of several aortic diseases but the extent and degree of turbulent blood flow in the normal aorta is unknown. We aimed to quantify the extent and degree of turbulece in the normal aorta and to assess whether age impacts the degree of turbulence. 22 young normal males (23.7 +/- 3.0 y.o.) and 20 old normal males (70.9 +/- 3.5 y.o.) were examined using four dimensional flow magnetic resonance imaging (4D Flow MRI) to quantify the turbulent kinetic energy (TKE), a measure of the intensity of turbulence, in the aorta. All healthy subjects developed turbulent flow in the aorta, with total TKE of 3-19 mJ. The overall degree of turbulence in the entire aorta was similar between the groups, although the old subjects had about 73% more total TKE in the ascending aorta compared to the young subjects (young = 3.7 +/- 1.8 mJ, old = 6.4 +/- 2.4 mJ, p amp;lt; 0.001). This increase in ascending aorta TKE in old subjects was associated with age-related dilation of the ascending aorta which increases the volume available for turbulence development. Conversely, age-related dilation of the descending and abdominal aorta decreased the average flow velocity and suppressed the development of turbulence. In conclusion, turbulent blood flow develops in the aorta of normal subjects and is impacted by age-related geometric changes. Non-invasive assessment enables the determination of normal levels of turbulent flow in the aorta which is a prerequisite for understanding the role of turbulence in the pathophysiology of cardiovascular disease.

    Place, publisher, year, edition, pages
    FRONTIERS MEDIA SA, 2018
    Keywords
    turbulent kinetic energy (TKE); turbulent blood flow; aortic blood flow; aortic dilation; normal values; 4D flow MRI; phase contrast MRI
    National Category
    Physiology
    Identifiers
    urn:nbn:se:liu:diva-145129 (URN)10.3389/fphys.2018.00036 (DOI)000423400000001 ()29422871 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council [2013-6077, 2014-6191]; Swedish Heart and Lung foundation [20140398]; Kangwon National University [D1001179-01-01]; Basic Science Research Program through the National Research Foundation of Korea (NRF) - Ministry of Education [2016R1A6A3A03006337]

    Available from: 2018-02-19 Created: 2018-02-19 Last updated: 2019-04-17
    3. Assessment of Turbulent Flow Effects on the Vessel Wall Using Four-Dimensional Flow MRI
    Open this publication in new window or tab >>Assessment of Turbulent Flow Effects on the Vessel Wall Using Four-Dimensional Flow MRI
    2017 (English)In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 77, no 6, p. 2310-2319Article in journal (Refereed) Published
    Abstract [en]

    Purpose: To explore the use of MR-estimated turbulence quantities for the assessment of turbulent flow effects on the vessel wall. Methods: Numerical velocity data for two patient-derived models was obtained using computational fluid dynamics (CFD) for two physiological flow rates. The four-dimensional (4D) Flow MRI measurements were simulated at three different spatial resolutions and used to investigate the estimation of turbulent wall shear stress (tWSS) using the intravoxel standard deviation (IVSD) of velocity and turbulent kinetic energy (TKE) estimated near the vessel wall. Results: Accurate estimation of tWSS using the IVSD is limited by the spatial resolution achievable with 4D Flow MRI. TKE, estimated near the wall, has a strong linear relationship to the tWSS (mean R(2=)0.84). Near-wall TKE estimates from MR simulations have good agreement to CFD-derived ground truth (mean R-2=0.90). Maps of near-wall TKE have strong visual correspondence to tWSS. Conclusion: Near-wall estimation of TKE permits assessment of relative maps of tWSS, but direct estimation of tWSS is challenging due to limitations in spatial resolution. Assessment of tWSS and near-wall TKE may open new avenues for analysis of different pathologies. (C) 2016 International Society for Magnetic Resonance in Medicine

    Place, publisher, year, edition, pages
    WILEY, 2017
    Keywords
    phase contrast magnetic resonance imaging; wall shear stress; turbulence; turbulent kinetic energy; aorta
    National Category
    Medical Image Processing
    Identifiers
    urn:nbn:se:liu:diva-138232 (URN)10.1002/mrm.26308 (DOI)000401270900022 ()27350049 (PubMedID)
    Note

    Funding Agencies|Swedish Research Council; National Supercomputer Centre [SNIC2014-11-22]

    Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2019-04-17
  • 101713.
    Ziegler, Magnus
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Lantz, Jonas
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Ebbers, Tino
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Dyverfeldt, Petter
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Assessment of Turbulent Flow Effects on the Vessel Wall Using Four-Dimensional Flow MRI2017In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 77, no 6, p. 2310-2319Article in journal (Refereed)
    Abstract [en]

    Purpose: To explore the use of MR-estimated turbulence quantities for the assessment of turbulent flow effects on the vessel wall. Methods: Numerical velocity data for two patient-derived models was obtained using computational fluid dynamics (CFD) for two physiological flow rates. The four-dimensional (4D) Flow MRI measurements were simulated at three different spatial resolutions and used to investigate the estimation of turbulent wall shear stress (tWSS) using the intravoxel standard deviation (IVSD) of velocity and turbulent kinetic energy (TKE) estimated near the vessel wall. Results: Accurate estimation of tWSS using the IVSD is limited by the spatial resolution achievable with 4D Flow MRI. TKE, estimated near the wall, has a strong linear relationship to the tWSS (mean R(2=)0.84). Near-wall TKE estimates from MR simulations have good agreement to CFD-derived ground truth (mean R-2=0.90). Maps of near-wall TKE have strong visual correspondence to tWSS. Conclusion: Near-wall estimation of TKE permits assessment of relative maps of tWSS, but direct estimation of tWSS is challenging due to limitations in spatial resolution. Assessment of tWSS and near-wall TKE may open new avenues for analysis of different pathologies. (C) 2016 International Society for Magnetic Resonance in Medicine

  • 101714.
    Ziegler, Magnus
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Welander, Martin
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Lantz, Jonas
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Lindenberger, Marcus
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Bjarnegård, Niclas
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Ebbers, Tino
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Dyverfeldt, Petter
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Visualizing and quantifying flow stasis in abdominal aortic aneurysms in men using 4D flow MRI2019In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 57, p. 103-110Article in journal (Refereed)
    Abstract [en]

    Purpose: To examine methods for visualizing and quantifying flow stasis in abdominal aortic aneurysms (AAA) using 4D Flow MRI. Methods: Three methods were investigated: conventional volumetric residence time (VRT), mean velocity analysis (MVA), and particle travel distance analysis (TDA). First, ideal 4D Flow MRI data was generated using numerical simulations and used as a platform to explore the effects of noise and background phase-offset errors, both of which are common 4D Flow MRI artifacts. Error-free results were compared to noise or offset affected results using linear regression. Subsequently, 4D Flow MRI data for thirteen (13) subjects with AAA was acquired and used to compare the stasis quantification methods against conventional flow visualization. Results: VRT (R-2 = 0.69) was more sensitive to noise than MVA (R-2 = 0.98) and TDA (R-2 = 0.99) at typical noncontrast signal-to-noise ratio levels (SNR = 20). VRT (R-2 = 0.14) was more sensitive to background phase-offsets than MVA (R-2 = 0.99) and TDA (R-2 = 0.96) when considering a 95% effective background phase-offset correction. Qualitatively, TDA outperformed MVA (Wilcoxon p amp;lt; 0.005, mean score improvement 1.6/5), and had good agreement (median score 4/5) with flow visualizations. Conclusion: Flow stasis can be quantitatively assessed using 4D Flow MRI. While conventional residence time calculations fail due to error accumulation as a result of imperfect measured velocity fields, methods that do not require lengthy particle tracking perform better. MVA and TDA are less sensitive to measurement errors, and TDA generates results most similar to those obtained using conventional flow visualization.

  • 101715. Ziehe, Thomas
    Självrefererandet kan inte undvikas: Några effekter av undervisningens rationaliseringar1994In: Ungdomar i skilda sfärer, Johan Fornäs, Ulf Boëthius och Bo Reimer (red.), Stockholm: Brutus Östlings Bokförlag Symposion AB , 1994, p. 285-297Chapter in book (Other academic)
    Abstract [en]

    Ett av de signifikativa kännetecknen för den kulturella moderniseringen är ökningen av självreferensstrukturer. Självreferenser ändrar på ett subtilt sätt vår relation till världen och till oss själva. Jag skulle med ledning av några fenomen här vilja visa hur självreferensen även trängt in i vår pedagogiska vardag och nu förändrar den inifrån. För detta har jag valt ut tre områden där man kan påvisa detta resultat av moderniseringen – den pedagogiska vetenskapen, skolans praxis och individernas identitetsutveckling.

  • 101716.
    Zielinski, Andrzej
    et al.
    Blekinge Centre Competence, Sweden .
    Borgquist, Lars
    Linköping University, Department of Medical and Health Sciences, General Practice. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in the West of Östergötland, Unit of Research and Development in Local Health Care, County of Östergötland.
    Halling, Anders
    University of Southern Denmark, Denmark .
    Distance to hospital and socioeconomic status influence secondary health care use2013In: Scandinavian Journal of Primary Health Care, ISSN 0281-3432, E-ISSN 1502-7724, Vol. 31, no 2, p. 83-88Article in journal (Refereed)
    Abstract [en]

    Objective. The aim of this study was to investigate how distance to hospital and socioeconomic status (SES) influence the use of secondary health care (SHC) when taking comorbidity into account. Design and setting. A register-based study in Ostergotland County. Subjects. The adult population of Ostergotland County. Main outcome measures. Odds of SHC use in the population and rates of SHC use by patients were studied after taking into account comorbidity level assigned using the Adjusted Clinical Groups (ACG) Case-Mix System. The baseline for analysis of SES was individuals with the lowest education level (level 1) and the lowest income (1st quartile). Results. The study showed both positive and negative association between SES and use of SHC. The risk of incurring SHC costs was 12% higher for individuals with education level 1. Individuals with income in the 2nd quartile had a 4% higher risk of incurring SHC costs but a 17% lower risk of emergency department visits. Individuals with income in the 4th quartile had 9% lower risk of hospitalization. The risk of using SHC services for the population was not associated with distance to hospital. Patients living over 40 km from hospital and patients with higher SES had lower use of SHC services. Conclusions. It was found that distance to hospital and SES influence SHC use after adjusting for comorbidity level, age, and gender. These results suggest that GPs and health care managers should pay a higher degree of attention to this when planning primary care services in order to minimize the potentially redundant use of SHC.

  • 101717.
    Ziels, Ryan
    et al.
    Linköping University, Biogas Research Center. University of Washington, USA.
    Gustavsson, Carl
    Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB.
    Shakeri Yekta, Sepehr
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Impacts of co-digestion waste vegetable oil with primary and wasteactivated sludge on microbial community and process performance2014Conference paper (Refereed)
  • 101718.
    Ziels, Ryan
    et al.
    Linköping University, Biogas Research Center. Civil and Environmental Engineering, University of Washington, WA, USA.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Beck, David A.C.
    Science Institute, University of Washington, WA, USA.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences. Scandinavian Biogas Fuels AB, Sweden.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences.
    Stensel, H. David
    Civil and Environmental Engineering, University of Washington, WA, USA.
    Svensson, Bo H.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences.
    Microbial community adaptation influences long-chain fatty acidconversion during anaerobic codigestion of fats, oils, and grease withmunicipal sludge2016In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 103, p. 372-382Article in journal (Refereed)
    Abstract [en]

    Codigesting fats, oils, and greases with municipal wastewater sludge can greatly improve biomethanerecovery at wastewater treatment facilities. Process loading rates of fats, oils, and greases have beenpreviously tested with little knowledge of the digester microbial community structure, and high transientfat loadings have led to long chain fatty acid (LCFA) accumulation and digester upsets. This studyutilized recently-developed quantitative PCR assays for syntrophic LCFA-degrading bacteria along with16S amplicon sequencing to relate changes in microbial community structure to LCFA accumulationduring transient loading increases to an anaerobic codigester receiving waste restaurant oil andmunicipal wastewater sludge. The 16S rRNA gene concentration of the syntrophic b-oxidizing genusSyntrophomonas increased to ~15% of the Bacteria community in the codigester, but stayed below 3% inthe control digester that was fed only wastewater sludge. Methanosaeta and Methanospirillum were thedominant methanogenic genera enriched in the codigester, and together comprised over 80% of theArchaea community by the end of the experimental period. Constrained ordination showed that changesin the codigester Bacteria and Archaea community structures were related to measures of digester performance.Notably, the effluent LCFA concentration in the codigester was positively correlated to thespecific loading rate of waste oil normalized to the Syntrophomonas 16S rRNA concentration. Specificloading rates of 0e1.5 1012 g VS oil/16S gene copies-day resulted in LCFA concentrations below 30 mg/g TS, whereas LCFA accumulated up to 104 mg/g TS at higher transient loading rates. Based on thecommunity-dependent loading limitations found, enhanced biomethane production from high loadingsof fats, oils and greases can be achieved by promoting a higher biomass of slow-growing syntrophicconsortia, such as with longer digester solids retention times. This work also demonstrates the potentialfor controlling the loading rate of fats, oils, and greases based on the analysis of the codigester communitystructure, such as with quantitative PCR measurements of syntrophic LCFA-degrading bacteriaabundance.

  • 101719.
    Ziels, Ryan M.
    et al.
    University of Washington, WA 98195 USA.
    Beck, David A. C.
    University of Washington, WA 98195 USA; University of Washington, WA 98195 USA.
    Genero, Magalí Martí
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Gough, Heidi L.
    University of Washington, WA 98195 USA.
    Stensel, H. David
    University of Washington, WA 98195 USA.
    Svensson, Bo
    Linköping University, The Tema Institute, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Monitoring the dynamics of syntrophic beta-oxidizing bacteria during anaerobic degradation of oleic acid by quantitative PCR2015In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 91, no 4Article in journal (Refereed)
    Abstract [en]

    The ecophysiology of long-chain fatty acid-degrading syntrophic beta-oxidizing bacteria has been poorly understood due to a lack of quantitative abundance data. Here, TaqMan quantitative PCR (qPCR) assays targeting the 16S rRNA gene of the known mesophilic syntrophic beta-oxidizing bacterial genera Syntrophomonas and Syntrophus were developed and validated. Microbial community dynamics were followed using qPCR and Illumina-based high-throughput amplicon sequencing in triplicate methanogenic bioreactors subjected to five consecutive batch feedings of oleic acid. With repeated oleic acid feeding, the initial specific methane production rate significantly increased along with the relative abundances of Syntrophomonas and methanogenic archaea in the bioreactor communities. The novel qPCR assays showed that Syntrophomonas increased from 7 to 31% of the bacterial community 16S rRNA gene concentration, whereas that of Syntrophus decreased from 0.02 to less than 0.005%. High-throughput amplicon sequencing also revealed that Syntrophomonas became the dominant genus within the bioreactor microbiomes. These results suggest that increased specific mineralization rates of oleic acid were attributed to quantitative shifts within the microbial communities toward higher abundances of syntrophic beta-oxidizing bacteria and methanogenic archaea. The novel qPCR assays targeting syntrophic beta-oxidizing bacteria may thus serve as monitoring tools to indicate the fatty acid beta-oxidization potential of anaerobic digester communities.

  • 101720.
    Ziels, Ryan M.
    et al.
    Department of Civil Engineering, The University of British Columbia, Vancouver, BC, Canada.
    Svensson, Bo H
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Sundberg, Carina
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Arts and Sciences.
    Larsson, Madeleine
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Karlsson, Anna
    Scandinavian Biogas Fuels AB, Stockholm, Sweden.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Microbial rRNA gene expression and co-occurrence profiles associate with biokinetics and elemental composition in full-scale anaerobic digesters2018In: Microbial Biotechnology, ISSN 1751-7907, E-ISSN 1751-7915, Vol. 11, no 4, p. 694-709Article in journal (Refereed)
    Abstract [en]

    This study examined whether the abundance and expression of microbial 16S rRNA genes were associated with elemental concentrations and substrate conversion biokinetics in 20 full-scale anaerobic digesters, including seven municipal sewage sludge (SS) digesters and 13 industrial codigesters. SS digester contents had higher methane production rates from acetate, propionate and phenyl acetate compared to industrial codigesters. SS digesters and industrial codigesters were distinctly clustered based on their elemental concentrations, with higher concentrations of NH3-N, Cl, K and Na observed in codigesters. Amplicon sequencing of 16S rRNA genes and reverse-transcribed 16S rRNA revealed divergent grouping of microbial communities between mesophilic SS digesters, mesophilic codigesters and thermophilic digesters. Higher intradigester distances between Archaea 16S rRNA and rRNA gene profiles were observed in mesophilic codigesters, which also had the lowest acetate utilization biokinetics. Constrained ordination showed that microbial rRNA and rRNA gene profiles were significantly associated with maximum methane production rates from acetate, propionate, oleate and phenyl acetate, as well as concentrations of NH3-N, Fe, S, Mo and Ni. A co-occurrence network of rRNA gene expression confirmed the three main clusters of anaerobic digester communities based on active populations. Syntrophic and methanogenic taxa were highly represented within the subnetworks, indicating that obligate energy-sharing partnerships play critical roles in stabilizing the digester microbiome. Overall, these results provide new evidence showing that different feed substrates associate with different micronutrient compositions in anaerobic digesters, which in turn may influence microbial abundance, activity and function.

  • 101721.
    Ziemke, Tom
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. University of Skövde.
    Czym jest to, co zwiemy ucieleśnieniem?: (What's that Thing Called Embodiment?)2015In: AVANT - Trends in Interdisciplinary Studies, ISSN 2082-6710, Vol. VI, no 3, p. 161-174Article in journal (Refereed)
    Abstract [en]

    Embodiment has become an important concept in many areas of cognitivescience. There are, however, very different notions of exactly what embodiment is andwhat kind of body is required for what type of embodied cognition. Hence, while manynowadays would agree that humans are embodied cognizers, there is much lessagreement on what kind of artifact could be considered embodied. This paper identifiesand contrasts six different notions of embodiment which can roughly be characterizedas (1) structural coupling between agent and environment, (2) historical embodimentas the result of a history of struct ural coupling, (3) physical embodiment,(4) organismoid embodiment, i.e. organism-like bodily form (e.g., humanoid robots),(5) organismic embodiment of autopoietic, living systems, and (6) social embodiment.

  • 101722.
    Ziemke, Tom
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. Interaction Lab, School of Informatics, University of Skövde, Skövde, Swede.
    The body of knowledge: On the role of the living body in grounding embodied cognition2016In: Biosystems (Amsterdam. Print), ISSN 0303-2647, E-ISSN 1872-8324, Vol. 148, p. 4-11Article, review/survey (Refereed)
    Abstract [en]

    Embodied cognition is a hot topic in both cognitive science and AI, despite the fact that there still is relatively little consensus regarding what exactly constitutes ‘embodiment’. While most embodied AI and cognitive robotics research views the body as the physical/sensorimotor interface that allows to ground computational cognitive processes in sensorimotor interactions with the environment, more biologically-based notions of embodied cognition emphasize the fundamental role that the living body – and more specifically its homeostatic/allostatic self-regulation – plays in grounding both sensorimotor interactions and embodied cognitive processes. Adopting the latter position – a multi-tiered affectively embodied view of cognition in living systems – it is further argued that modeling organisms as layered networks of bodily self-regulation mechanisms can make significant contributions to our scientific understanding of embodied cognition.

  • 101723.
    Ziemke, Tom
    et al.
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Arvola, MattiasLinköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.Dahlbäck, NilsLinköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Arts and Sciences.Billing, ErikInstitutionen för informationsteknologi, Högskolan i Skövde.
    Proceedings of the 14th SweCog Conference: Linköping 2018, 11-12 October2018Conference proceedings (editor) (Refereed)
    Abstract [en]

    Welcome to SweCog 2018 in Linköping!

    This booklet contains the program and short papers for oral and poster presentations at SweCog 2018, this year’s edition of the annual conference of the Swedish Cognitive Science Society. Following the SweCog tradition and its aim to support networking among researchers in cognitive science and related areas, contributions cover a wide spectrum of research.

    A trend in recent years, also reflected in this year’s conference program, is an increasing number of contributions that deal with different types of autonomous technologies, such as social robots, virtual agents or automated vehicles, and in particular people’s interaction with such systems. This clearly is a growing research area of high societal relevance, where cognitive science - with its interdisciplinary and human-centered approach - can make significant contributions.

    We look forward to two exciting days in Linköping, and we thank the many people who have contributed to the organization of this year’s SweCog conference, in particular of course all authors and reviewers! The organization of SweCog 2018 has been supported by the Faculty of Arts and Sciences, the Department of Culture Communication (IKK), and the Department of Computer Information Science (IDA) at Linköpping University, as well as Cambio Healthcare Systems and Visual Sweden.

    Tom Ziemke, Mattias Arvola, Nils Dahlbäc and Erik Billing

  • 101724.
    Ziemke, Tom
    et al.
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering. University of Skövde, Sweden.
    Schaefer, Kristin E.
    US Army, MD USA.
    Endsley, Mica
    SA Technologies, CA USA.
    Situation awareness in human-machine interactive systems2017In: Cognitive Systems Research, ISSN 2214-4366, E-ISSN 1389-0417, Vol. 46Article in journal (Other academic)
    Abstract [en]

    This special issue brings together six papers on situation awareness in human-machine interactive systems, in particular in teams of collaborating humans and artificial agents. The editorial provides a brief introduction and overviews the contributions, addressing issues such as team and shared situation awareness, trust, transparency, timing, engagement, and ethical aspects. (C) 2017 Published by Elsevier B.V.

  • 101725.
    Ziemssen, Tjalf
    et al.
    Neurol University of Klin Klinikum Carl Gustav Carus, Germany.
    Bajenaru, Ovidiu A.
    Carol Davila University of Medical and Pharm, Romania.
    Carra, Adriana
    Hospital Britanico Buenos Aires, Argentina.
    de Klippel, Nina
    Virga Jessaziekenhuis, Belgium.
    Correia de Sa, Joao
    Hospital Santa Maria, Portugal.
    Edland, Astrid
    Central Hospital Buskerud, Norway.
    Frederiksen, Jette L.
    University of Copenhagen, Denmark.
    Heinzlef, Olivier
    Tenon Hospital, France.
    Karageorgiou, Klimentini E.
    Gen Hospital Athens, Greece.
    Delgado, Rafael H. Lander
    Landtblom, Anne-Marie
    Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Local Health Care Services in Central Östergötland, Department of Neurology.
    Macias Islas, Miguel A.
    Central University of Guadalajara, Mexico.
    Tubridy, Niall
    Dublin University, Ireland.
    Gilgun-Sherki, Yossi
    Teva Pharmaceut Ind Ltd, Israel.
    Erratum to: A 2-year observational study of patients with relapsing-remitting multiple sclerosis converting to glatiramer acetate from other disease-modifying therapies: the COPTIMIZE trial2015In: Journal of Neurology, ISSN 0340-5354, E-ISSN 1432-1459, Vol. 262, no 1, p. 248-248Article in journal (Other academic)
    Abstract [en]

    n/a

  • 101726.
    Ziemssen, Tjalf
    et al.
    Klinikum Carl Gustav Carus, Germany.
    Bajenaru, Ovidiu A.
    Carol Davila University of Medical and Pharm, Romania.
    Carra, Adriana
    Hospital Britanico Buenos Aires, Argentina.
    de Klippel, Nina
    Virga Jessaziekenhuis, Belgium.
    de Sa, Joao C.
    Hospital Santa Mari, Belgium.
    Edland, Astrid
    Central Hospital Buskerud, Norway.
    Frederiksen, Jette L.
    University of Copenhagen, Denmark.
    Heinzlef, Olivier
    Hop Tenon, France.
    Karageorgiou, Klimentini E.
    Gen Hospital Athens, Greece.
    Lander Delgado, Rafael H.
    Landtblom, Anne-Marie
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Neurology. Östergötlands Läns Landsting, Local Health Care Services in West Östergötland, Department of Medical Specialist in Motala.
    Macias Islas, Miguel A.
    Central University of Guadalajara, Mexico.
    Tubridy, Niall
    Dublin City University, Ireland.
    Gilgun-Sherki, Yossi
    Teva Pharmaceut Ind Ltd, Israel.
    A 2-year observational study of patients with relapsing-remitting multiple sclerosis converting to glatiramer acetate from other disease-modifying therapies: the COPTIMIZE trial2014In: Journal of Neurology, ISSN 0340-5354, E-ISSN 1432-1459, Vol. 261, no 11, p. 2101-2111Article in journal (Refereed)
    Abstract [en]

    Studies suggest that patients with relapsing-remitting multiple sclerosis (RRMS) who do not benefit from other disease-modifying treatments (DMTs) may benefit from converting to glatiramer acetate (GA). COPTIMIZE was a 24-month observational study designed to assess the disease course of patients converting to GA 20 mg daily from another DMT. Eligible patients had converted to GA and had received prior DMT for 3-6 months, depending on the reasons for conversion. Patients were assessed at baseline and at 6, 12, 18, and 24 months. In total, 672 patients from 148 centers worldwide were included in the analysis. Change of therapy to GA was prompted primarily by lack of efficacy (53.6 %) or intolerable adverse events (AEs; 44.8 %). Over a 24-month period, 72.7 % of patients were relapse free. Mean annual relapse rate decreased from 0.86 [95 % confidence interval (CI) 0.81-0.91] before the change to 0.32 (95 % CI 0.26-0.40; p less than 0.0001) at last observation, while the progression of disability was halted, as the Kurtzke Expanded Disability Status Scale (EDSS) scores remained stable. Patients improved significantly (p less than 0.05) on measures of fatigue, quality of life, depression, and cognition; mobility scores remained stable. The results indicate that changing RRMS patients to GA is associated with positive treatment outcomes.

  • 101727.
    Zika, Rebecca
    Linköping University, Department of Management and Engineering, Commercial and Business Law. Linköping University, Faculty of Arts and Sciences.
    Omvandlingar av fordringar i obeståndssituationer: Får avdrag för kapitalförlust göras för fordran som omvandlats till ett ovillkorat aktieägartillskott2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Uppsatsen behandlar aktieägarens rätt till avdrag för kapitalförlust när denne har omvandlat en fordran på det egna bolaget till ett ovillkorat aktieägartillskott vid en obeståndssituation. Detta omnämns i uppsatsen som omvandlingssituationen. Problematiken kring detta ligger i att aktieägartillskott inte är särreglerade varken inom civilrätten eller skatterätten. Det finns inte heller några klara förarbetsuttalanden.

    I mars 2009 kom det ett antal domar från Regeringsrätten som behandlade huruvida en aktieägare skulle få göra förlustavdrag i den ovan nämnda omvandlingssituationen. Sakomständigheterna i de olika målen var snarlika och domskälen var därmed närmast identiska i dessa mål, ett av målen är ett referatmål och heter RÅ 2009 ref. 41. I målet ansåg majoriteten att fordran skulle anses vara avyttrad i och med omvandlingen till aktieägartillskottet. Därmed skulle aktieägaren få göra avdrag för den kapitalförlust som uppkom.

    De skiljaktiga i målet menade att eftersom fordran som omvandlats saknade marknadsvärde vid omvandlingstillfället har inte heller aktieägartillskottet något värde. Detta innebär enligt de skiljaktiga att aktieägaren inte har fått någon ersättning för sin fordran och den kunde inte anses vara avyttrad. Det som vållat förvirring efter 2009 års mål är att de skiljaktiga återanvände argumenten från RÅ 2002 ref. 107 och RÅ 2002 not. 216, trots att målen inte behandlade samma rättsfrågor. Uppsatsens syfte är därför att behandla  rågorna som uppkommer kring omvandlingssituationen och försöka reda ut den förvirring som råder.

    Aktieägartillskott är inte ursprungligen en rent skatterättslig företeelse utan har från början utvecklats inom bolagsrätten. Det råder en viss osäkerhet kring behandlingen av aktieägartillskott eftersom de inte är särreglerade vare sig civilrättsligt eller skatterättsligt. Regleringen kring aktieägartillskott har istället utvecklats i praxis. Generellt kan sägas om aktieägartillskott att dessa i praktiken lämnas av aktieägare, som vill rädda bolaget från skyldighet att träda i likvidation. Ovillkorade aktieägartillskott ses som rena kapitaltillskott medan villkorade aktieägartillskott lämnas med villkor om återbetalning när bolaget har fritt eget kapital.

    Avyttringsbegreppet är utförligt reglerat i 44 kap. 3-10 §§ inkomstskattelagen. Trots denna utförliga reglering av avyttringsbegreppet har rättspraxis ofta fått sätta gränserna för tolkningen av detta begrepp. Den nuvarande lagregleringen kring avyttringsbegreppet infördes från början i samband med 1990 års skattereform. I propositionen till förändringen skrevs bland annat att den vida innebörd som avyttringsbegreppet givits i praxis inte skulle inskränkas. Formuleringen i lagtexten skulle alltså inte inskränka gällande rätt. Med avyttring skulle avses enligt 44 kap. 3 § IL köp, byte eller därmed jämförliga överlåtelser. Denna formulering hade utvecklats i praxis och fanns även med i propositionen från 1967 men hade dittills inte lagreglerats. Vid 1990 års skattereform infördes den i lagtexten och i propositionen konstaterade man att det avgörande för att avyttring ska föreligga är att egendomen eller del av egendomen definitivt avhänts ägaren. Detta gäller även om egendomen inte byter ägare utan istället upphör att existera.

    Rättsfrågan i målen från 2009 var om en fordran hade avyttrats och om det i så fall hade uppkommit en avdragsgill kapitalförlust. Ett aktieägartillskott kan ske genom att givaren, när bolaget är i en obeståndssituation, omvandlar en fordran som denne har på bolaget till ett ovillkorat aktieägartillskott, alltså den omvandlingssituation som uppsatsen behandlar. Bolagets nettobehållning ökar då med ett belopp uppgående till fordrans nominella värde. Detta sker även om marknadsvärdet på fordran vid omvandlingstillfället skulle vara lägre än det nominella beloppet. I omvandlingssituationen har det i samtliga fall, i rättspraxis, konstaterats att fordran har varit värdelös vid omvandlingstillfället, eftersom den saknar marknadsvärde.

    Jag har inte kunnat påvisa att målen från 2002 och 2009 har blivit inkonsekvent dömda eller att 2009 års mål borde fått någon annan utgång. För att klargöra rättsläget skulle det dock vara bra om ett liknande mål togs upp och dömdes med samma utgång i plenum eller åtminstone utan skiljaktiga regeringsråd.

  • 101728.
    Zikrin, Spartak
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Large-Scale Optimization Methods with Application to Design of Filter Networks2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nowadays, large-scale optimization problems are among those most challenging. Any progress in developing methods for large-scale optimization results in solving important applied problems more effectively. Limited memory methods and trust-region methods represent two ecient approaches used for solving unconstrained optimization problems. A straightforward combination of them deteriorates the efficiency of the former approach, especially in the case of large-scale problems. For this reason, the limited memory methods are usually combined with a line search. We develop new limited memory trust-region algorithms for large-scale unconstrained optimization. They are competitive with the traditional limited memory line-search algorithms.

    In this thesis, we consider applied optimization problems originating from the design of lter networks. Filter networks represent an ecient tool in medical image processing. It is based on replacing a set of dense multidimensional lters by a network of smaller sparse lters called sub-filters. This allows for improving image processing time, while maintaining image quality and the robustness of image processing.

    Design of lter networks is a nontrivial procedure that involves three steps: 1) choosing the network structure, 2) choosing the sparsity pattern of each sub-filter and 3) optimizing the nonzero coecient values. So far, steps 1 and 2 were mainly based on the individual expertise of network designers and their intuition. Given a sparsity pattern, the choice of the coecients at stage 3 is related to solving a weighted nonlinear least-squares problem. Even in the case of sequentially connected lters, the resulting problem is of a multilinear least-squares (MLLS) type, which is a non-convex large-scale optimization problem. This is a very dicult global optimization problem that may have a large number of local minima, and each of them is singular and non-isolated. It is characterized by a large number of decision variables, especially for 3D and 4D lters.

    We develop an effective global optimization approach to solving the MLLS problem that reduces signicantly the computational time. Furthermore, we  develop efficient methods for optimizing sparsity of individual sub-filters  in lter networks of a more general structure. This approach offers practitioners a means of nding a proper trade-o between the image processing quality and time. It allows also for improving the network structure, which makes automated some stages of designing lter networks.

    List of papers
    1. On Efficiently Combining Limited Memory and Trust-Region Techniques
    Open this publication in new window or tab >>On Efficiently Combining Limited Memory and Trust-Region Techniques
    2013 (English)Report (Other academic)
    Abstract [en]

    Limited memory quasi-Newton methods and trust-region methods represent two efficient approaches used for solving unconstrained optimization problems. A straightforward combination of them deteriorates the efficiency of the former approach, especially in the case of large-scale problems. For this reason, the limited memory methods are usually combined with a line search. We show how to efficiently combine limited memory and trust-region techniques. One of our approaches is based on the eigenvalue decomposition of the limited memory quasi-Newton approximation of the Hessian matrix. The decomposition allows for finding a nearly-exact solution to the trust-region subproblem defined by the Euclidean norm with an insignificant computational overhead compared with the cost of computing the quasi-Newton direction in line-search limited memory methods. The other approach is based on two new eigenvalue-based norms. The advantage of the new norms is that the trust-region subproblem is separable and each of the smaller subproblems is easy to solve. We show that our eigenvalue-based limited-memory trust-region methods are globally convergent. Moreover, we propose improved versions of the existing limited-memory trust-region algorithms. The presented results of numerical experiments demonstrate the efficiency of our approach which is competitive with line-search versions of the L-BFGS method.

    Place, publisher, year, edition, pages
    Linköping: Linköping University Electronic Press, 2013. p. 33
    Series
    LiTH-MAT-R, ISSN 0348-2960 ; 2013:13
    Keywords
    Unconstrained Optimization; Large-scale Problems; Limited Memory Methods;
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:liu:diva-102005 (URN)LiTH-MAT-R--2013/13--SE (ISRN)
    Available from: 2013-11-26 Created: 2013-11-26 Last updated: 2016-01-12Bibliographically approved
    2. Global search strategies for solving multilinear least-squares problems
    Open this publication in new window or tab >>Global search strategies for solving multilinear least-squares problems
    2012 (English)In: Sultan Qaboos University Journal for Science, ISSN 1027-524X, Vol. 17, no 1, p. 12-21Article in journal (Refereed) Published
    Abstract [en]

    The multilinear least-squares (MLLS) problem is an extension of the linear leastsquares problem. The difference is that a multilinear operator is used in place of a matrix-vector product. The MLLS is typically a large-scale problem characterized by a large number of local minimizers. It originates, for instance, from the design of filter networks. We present a global search strategy that allows for moving from one local minimizer to a better one. The efficiency of this strategy is illustrated by results of numerical experiments performed for some problems related to the design of filter networks.

    Place, publisher, year, edition, pages
    Sultan Qaboos University, 2012
    Keywords
    Global optimization; Global search strategies; Multilinear least-squares; Filter
    National Category
    Computational Mathematics Medical Image Processing
    Identifiers
    urn:nbn:se:liu:diva-78918 (URN)
    Available from: 2012-08-28 Created: 2012-06-25 Last updated: 2015-09-03Bibliographically approved
    3. Sparsity Optimization in Design of Multidimensional Filter Networks
    Open this publication in new window or tab >>Sparsity Optimization in Design of Multidimensional Filter Networks
    2013 (English)Report (Other academic)
    Abstract [en]

    Filter networks is a powerful tool used for reducing the image processing time, while maintaining its reasonably high quality.They are composed of sparse sub-filters whose low sparsity ensures fast image processing.The filter network design is related to solvinga sparse optimization problem where a cardinality constraint bounds above the sparsity level.In the case of sequentially connected sub-filters, which is the simplest network structure of those considered in this paper, a cardinality-constrained multilinear least-squares (MLLS) problem is to be solved. If to disregard the cardinality constraint, the MLLS is typically a large-scale problem characterized by a large number of local minimizers. Each of the local minimizers is singular and non-isolated.The cardinality constraint makes the problem even more difficult to solve.An approach for approximately solving the cardinality-constrained MLLS problem is presented.It is then applied to solving a bi-criteria optimization problem in which both thetime and quality of image processing are optimized. The developed approach is extended to designing filter networks of a more general structure. Its efficiency is demonstrated by designing certain 2D and 3D filter networks. It is also compared with the existing approaches.

    Place, publisher, year, edition, pages
    Linköping: Linköping University Electronic Press, 2013. p. 21
    Series
    LiTH-MAT-R, ISSN 0348-2960 ; 2013:16
    Keywords
    Sparse optimization; Cardinality Constraint; Multicriteria Optimization; Multilinear Least-Squares Problem; Filter networks; Medical imaging
    National Category
    Computational Mathematics Medical Image Processing Signal Processing
    Identifiers
    urn:nbn:se:liu:diva-103915 (URN)LiTH-MAT-R-2013/16-SE (ISRN)
    Available from: 2014-02-03 Created: 2014-02-03 Last updated: 2016-11-24Bibliographically approved
  • 101729.
    Zilg, B.
    et al.
    Karolinska Institute, Sweden.
    Alkass, K.
    Karolinska Institute, Sweden.
    Berg, Sören
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Druid, H.
    Karolinska Institute, Sweden.
    Interpretation of postmortem vitreous concentrations of sodium and chloride2016In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 263, p. 107-113Article in journal (Refereed)
    Abstract [en]

    Vitreous fluid can be used to analyze sodium and chloride levels in deceased persons, but it remains unclear to what extent such results can be used to diagnose antemortem sodium or chloride imbalances. In this study we present vitreous sodium and chloride levels from more than 3000 cases. We show that vitreous sodium and chloride levels both decrease with approximately 2.2 mmol/L per day after death. Since potassium is a well-established marker for postmortem interval (PMI) and easily can be analyzed along with sodium and chloride, we have correlated sodium and chloride levels with the potassium levels and present postmortem reference ranges relative the potassium levels. We found that virtually all cases outside the reference range show signs of antemortem hypo- or hypernatremia. Vitreous sodium or chloride levels can be the only means to diagnose cases of water or salt intoxication, beer potomania or dehydration. We further show that postmortem vitreous sodium and chloride strongly correlate and in practice can be used interchangeably if analysis of one of the ions fails. It has been suggested that vitreous sodium and chloride levels can be used to diagnose drowning or to distinguish saltwater from freshwater drowning. Our results show that in cases of freshwater drowning, vitreous sodium levels are decreased, but that this mainly is an effect of postmortem diffusion between the eye and surrounding water rather than due to the drowning process, since the decrease in sodium levels correlates with immersion time. (C) 2016 Elsevier Ireland Ltd. All rights reserved.

  • 101730.
    Zilg, B
    et al.
    Karolinska Institute.
    Alkass, K
    Karolinska Institute.
    Berg, Sören
    Linköping University, Department of Medical and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences.
    Druid, H
    Karolinska Institute.
    Postmortem identification of hyperglycemia2009In: FORENSIC SCIENCE INTERNATIONAL, ISSN 0379-0738, Vol. 185, no 1-3, p. 89-95Article in journal (Refereed)
    Abstract [en]

    The detection of diabetic coma postmortem requires accurate biochemical analysis. Due to continuous consumption of glucose by surviving cells postmortem, blood glucose levels decrease rapidly. Therefore, vitreous fluid has been used as a substitute in forensic practice, since it has a very low cell count, It has been repeatedly reported that the sum value of vitreous glucose and lactate should be used to estimate the original antemortem blood glucose level, based on the assumption that pre-existing glucose is gradually converted to lactate under anaerobic conditions during agonal phase and the early postmortem period. in this Study, we applied a strategy including consistent sampling of vitreous fluid from the centre of both eyes of deceased subjects as soon as possible after arrival at the morgue, and immediate bedside analysis using a blood gas instrument. In total, 3076 cases were included during 2004-2006. We found that, after an initial drop of vitreous glucose during the very early postmortem period, the levels stayed stable for appreciable time postmortem. Analysis of a second sample collected at autopsy 1-3 days later gave similar results (R-2 = 0.90). In contrast, the vitreous lactate levels showed a steady increase. This implies that the sum value of glucose and lactate increases with postmortem time, as reflected by vitreous potassium level. In fact, a statistically significant difference in the SUM Value was seen between subjects with potassium below 10 mmol/L (n = 1086) and above 20 mmol/L (n = 531), p < .001. In addition, in this large material, we did not identify a single case with circumstantial indication of hyperglycemia that only showed high vitreous lactate. We therefore suggest that vitreous glucose alone Should be used to diagnose hyperglycemia postmortem and that the limit of 10 mmol/L should have a good specificity for diabetic coma, which theoretically would equal an original blood glucose value of about 26 mmol/L. As to the methodology, we found that sonication, centrifugation and addition of fluoride to the samples are unnecessary procedures when using a blood gas instrument. The strategy resulted in a doubling of the number of diabetic coma identified at our department compared to preceding period when analysis only was performed on selected cases.

  • 101731.
    Zilg, B.
    et al.
    Karolinska Institute, Sweden.
    Bernard, S.
    University of Lyon 1, France.
    Alkass, K.
    Karolinska Institute, Sweden.
    Berg, Sören
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Druid, H.
    Karolinska Institute, Sweden.
    A new model for the estimation of time of death from vitreous potassium levels corrected for age and temperature2015In: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 254, p. 158-166Article in journal (Refereed)
    Abstract [en]

    Analysis of potassium concentration in the vitreous fluid of the eye is frequently used by forensic pathologists to estimate the postmortem interval (PMI), particularly when other methods commonly used in the early phase of an investigation can no longer be applied. The postmortem rise in vitreous potassium has been recognized for several decades and is readily explained by a diffusion of potassium from surrounding cells into the vitreous fluid. However, there is no consensus regarding the mathematical equation that best describes this increase. The existing models assume a linear increase, but different slopes and starting points have been proposed. In this study, vitreous potassium levels, and a number of factors that may influence these levels, were examined in 462 cases with known postmortem intervals that ranged from 2 h to 17 days. We found that the postmortem rise in potassium followed a non-linear curve and that decedent age and ambient temperature influenced the variability by 16% and 5%, respectively. A long duration of agony and a high alcohol level at the time of death contributed less than 1% variability, and evaluation of additional possible factors revealed no detectable impact on the rise of vitreous potassium. Two equations were subsequently generated, one that represents the best fit of the potassium concentrations alone, and a second that represents potassium concentrations with correction for decedent age and/or ambient temperature. The former was associated with narrow confidence intervals in the early postmortem phase, but the intervals gradually increased with longer PMIs. For the latter equation, the confidence intervals were reduced at all PMIs. Therefore, the model that best describes the observed postmortem rise in vitreous potassium levels includes potassium concentration, decedent age, and ambient temperature. Furthermore, the precision of these equations, particularly for long PMIs, is expected to gradually improve by adjusting the constants as more reference data are added over time. A web application that facilitates this calculation process and allows for such future modifications has been developed. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

  • 101732.
    Zilic, Edmin
    Linköping University, Department of Electrical Engineering.
    Implementering av 1D-DCT2006Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    IDCT (Inverse Discrete Cosine Transform) is a common algorithm being used with image and sound decompression. The algorithm is a Fourier related transform which can occur in many different types like, one-dimensional, two-dimensional, three-dimensional and many more.

    The goal with this thesis is to create a fast and low effect version of two-dimensional IDCT algorithm, where techniques as multiple-constant multiplication and subexpression sharing plus bit-serial and bit-parallel arithmetic are used.

    The result is a hardware implementation with power consumption at 19,56 mW.

  • 101733.
    Zimdahl Kahlin, Anna
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Helander, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Chemistry. Linköping University, Faculty of Medicine and Health Sciences.
    Skoglund, Karin
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Söderkvist, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Mårtensson, Lars-Göran
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lindqvist Appell, Malin
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Comprehensive study of thiopurine methyltransferase genotype, phenotype, and genotype-phenotype discrepancies in Sweden2019In: Biochemical Pharmacology, ISSN 0006-2952, E-ISSN 1356-1839, Vol. 164, p. 263-272Article in journal (Refereed)
    Abstract [en]

    Thiopurines are widely used in the treatment of leukemia and inflammatory bowel diseases. Thiopurine metabolism varies among individuals because of differences in the polymorphic enzyme thiopurine methyltransferase (TPMT, EC 2.1.1.67), and to avoid severe adverse reactions caused by incorrect dosing it is recommended that the patients TPMT status be determined before the start of thiopurine treatment. This study describes the concordance between genotyping for common TPMT alleles and phenotyping in a Swedish cohort of 12,663 patients sampled before or during thiopurine treatment. The concordance between TPMT genotype and enzyme activity was 94.5%. Compared to the genotype, the first measurement of TPMT enzyme activity was lower than expected for 4.6% of the patients. Sequencing of all coding regions of the TPMT gene in genotype/phenotype discrepant individuals led to the identification of rare and novel TPMT alleles. Fifteen individuals (0.1%) with rare or novel genotypes were identified, and three TPMT alleles (TPMT*42, *43, and *44) are characterized here for the first time. These 15 patients would not have been detected as carrying a deviating TPMT genotype if only genotyping of the most common TPMT variants had been performed. This study highlights the benefit of combining TPMT genotype and phenotype determination in routine testing. More accurate dose recommendations can be made, which might decrease the number of adverse reactions and treatment failures during thiopurine treatment.

    The full text will be freely available from 2020-04-18 07:47
  • 101734.
    Zimmer, Hubert
    et al.
    Department of Psychology University of Zaarbrucken.
    Magnussen, Svein
    Psykologisk Institutt University of Oslo.
    Rudner, Mary
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences, The Swedish Institute for Disability Research.
    Rönnberg, Jerker
    Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Behavioural Sciences, The Swedish Institute for Disability Research.
    Visuospatial thinking, imagination, and remembering2007In: Everyday Memory / [ed] Svein Magnussen and Tore Helstrup, London: Psychology Press , 2007, p. 27-56Chapter in book (Other academic)
    Abstract [en]

        

    This book presents an authoritative overview of memory in everyday contexts. Written by an expert team of international authors, it gathers together research on some of the more neglected but revealing areas of memory, to provide a comprehensive overview of remembering in real life situations.

    Contributions from leading experts deal with a variety of important questions concerning everyday memory, from under-researched areas such as memory for odours, to more well known areas, like collective memory. Topics covered also include:

    • Beliefs about memory and the metaphors used to discuss memory
    • The relation between self-referent beliefs and actual memory performance
    • The development of autobiographical memory.

    Everyday Memory summarises current knowledge and presents new interpretations and hypotheses to be explored by future research. It discusses aspects of human memory which are frequently ignored or dealt with only very briefly by ordinary textbooks and as a result will have a broad appeal for researchers and students.

  • 101735.
    Zimmerli, Dario
    et al.
    Univ Zurich, Switzerland.
    Cecconi, Virginia
    Univ Zurich, Switzerland.
    Valenta, Tomas
    Univ Zurich, Switzerland.
    Hausmann, George
    Univ Zurich, Switzerland.
    Cantù, Claudio
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Univ Zurich, Switzerland.
    Restivo, Gaetana
    Univ Hosp Zurich, Switzerland.
    Hafner, Jurg
    Univ Hosp Zurich, Switzerland.
    Basler, Konrad
    Univ Zurich, Switzerland.
    van den Broek, Maries
    Univ Zurich, Switzerland.
    WNT ligands control initiation and progression of human papillomavirus-driven squamous cell carcinoma2018In: Oncogene, ISSN 0950-9232, E-ISSN 1476-5594, Vol. 37, no 27, p. 3753-3762Article in journal (Refereed)
    Abstract [en]

    Human papillomavirus (HPV)-driven cutaneous squamous cell carcinoma (cSCC) is the most common cancer in immunosuppressed patients. Despite indications suggesting that HPV promotes genomic instability during cSCC development, the molecular pathways underpinning HPV-driven cSCC development remain unknown. We compared the transcriptome of HPV-driven mouse cSCC with normal skin and observed higher amounts of transcripts for Porcupine and WNT ligands in cSCC, suggesting a role for WNT signaling in cSCC progression. We confirmed increased Porcupine expression in human cSCC samples. Blocking the secretion of WNT ligands by the Porcupine inhibitor LGK974 significantly diminished initiation and progression of HPV-driven cSCC. Administration of LGK974 to mice with established cSCC resulted in differentiation of cancer cells and significant reduction of the cancer stem cell compartment. Thus, WNT/beta-catenin signaling is essential for HPV-driven cSCC initiation and progression as well as for maintaining the cancer stem cell niche. Interference with WNT secretion may thus represent a promising approach for therapeutic intervention.

  • 101736.
    Zimmerli, Dario
    et al.
    Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland.
    Hausmann, George
    Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland.
    Cantù, Claudio
    Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland.
    Basler, Konrad
    Institute of Molecular Life Sciences, University of Zürich, Zürich, Switzerland.
    Pharmacological interventions in the Wnt pathway: inhibition of Wnt secretion versus disrupting the protein-protein interfaces of nuclear factors2017In: British Journal of Pharmacology, ISSN 0007-1188, E-ISSN 1476-5381, Vol. 174, no 24, p. 4600-4610Article in journal (Refereed)
    Abstract [en]

    Mutations in components of the Wnt pathways are a frequent cause of many human diseases, particularly cancer. Despite the fact that a causative link between aberrant Wnt signalling and many types of human cancers was established more than a decade ago, no Wnt signalling inhibitors have made it into the clinic so far. One reason for this is that no pathway-specific kinase is known. Additionally, targeting the protein-protein interactions needed to transduce the signal has not met with success so far. Complicating the search for and use of inhibitors is the complexity of the cascades triggered by the Wnts and their paramount biological importance. Wnt/β-catenin signalling is involved in virtually all aspects of embryonic development and in the control of the homeostasis of adult tissues. Encouragingly, however, in recent years, first successes with Wnt-pathway inhibitors have been reported in mouse models of disease. In this review, we summarize possible roads to follow during the quest to pharmacologically modulate the Wnt signalling pathway in cancer.

  • 101737.
    Zimmerli, Stefan
    et al.
    Division of Infectious Diseases and The Rosalind Russell Arthritis Research Laboratory, San Francisco General Hospital, University of California at San Francisco, San Francisco, California, USA.
    Majeed, Meytham
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Gustafsson, Mikael
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sanan, David A.
    Gladstone Institute of Cardiovascular Disease, San Francisco, California, USA.
    Ernst, Joel D.
    Division of Infectious Diseases and The Rosalind Russell Arthritis Research Laboratory, San Francisco General Hospital, University of California at San Francisco, San Francisco, California, USA.
    Phagosome-Lysosome Fusion Is a Calcium-independent Event in Macrophages1996In: Journal of Cell Biology, ISSN 0021-9525, E-ISSN 1540-8140, Vol. 132, no 1-2, p. 49-61Article in journal (Refereed)
    Abstract [en]

    Phagosome-lysosome membrane fusion is a highly regulated event that is essential for intracellular killing of microorganisms, Functionally, it represents a form of polarized regulated secretion, which is classically dependent on increases in intracellular ionized calcium ([Ca2+](i)). Indeed, increases in [Ca2+](i) are essential for phagosome-granule (lysosome) fusion in neutrophils and for lysosomal fusion events that mediate host cell invasion by Trypanosoma cruzi trypomastigotes, Since several intracellular pathogens survive in macrophage phagosomes that do not fuse with lysosomes, we examined the regulation of phagosome-lysosome fusion in macrophages. Macrophages (MO) were treated with 12.5 mu M bis-(2-amino-S-methylphenoxy) ethane-N,N,N',N',-tetraacetic acid tetraacetoxymethyl ester (MAPT/AM), a cell-permeant calcium chelator which reduced resting cytoplasmic [Ca2+]; from 80 nM to less than or equal to 20 nM and completely blocked increases in [Ca2+](i) in response to multiple stimuli, even in the presence of extracellular calcium, Subsequently, MO phagocytosed serum-opsonized zymosan, staphylococci, or Mycobacterium bovis, Microbes were enumerated by 4',6-diamidino-2-phenylindole, dihydrochloride (DAPI) staining, and phagosome-lysosome fusion was scored using both lysosome-associated membrane protein (LAMP-1) as a membrane marker and rhodamine dextran as a content marker for lysosomes, Confirmation of phagosomelysosome fusion by electron microscopy validated the fluorescence microscopy findings, We found that phagosome-lysosome fusion in MO occurs normally at very low [Ca2+](i) (less than or equal to 20 nM), Kinetic analysis showed that in MO none of the steps leading from particle binding to eventual phagosome-lysosome fusion are regulated by [Ca2+](i) in a rate-limiting way. Furthermore, confocal microscopy revealed no difference in the intensity of LAMP-1 immunofluorescence in phagolysosome membranes in calcium-buffered vs, control macrophages, We conclude that neither membrane recognition nor fusion events in the phagosomal pathway in macrophages are dependent on or regulated by calcium.

  • 101738.
    Zimmerman, Rosa
    et al.
    University of Buenos Aires.
    Broitman, Esteban
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology. University of Buenos Aires.
    Aplicaciones de las Peliculas Delgadas en Microelectronica1986In: Revista Telegrafica Electronica, ISSN 0035-0516, Vol. 75, no 880, p. 2052-2056Article in journal (Refereed)
    Abstract [es]

    En este articulo se presenta una reseña acerca del uso de las peliculas delgadas en microelectronica con especial enfasis en las peliculas resistivas. Se detallan las propiedades electricas de la aleacion niquel-cromo.

  • 101739.
    Zimmermann, F.
    et al.
    TU Bergakad Freiberg, Germany.
    Beyer, Franziska
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Gaertner, G.
    TU Bergakad Freiberg, Germany.
    Roeder, C.
    TU Bergakad Freiberg, Germany.
    Nguyen, Son Tien
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Janzén, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Vesela, D.
    Research Centre Rez, Czech Republic.
    Lorincik, J.
    Research Centre Rez, Czech Republic.
    Hofmann, P.
    NaMLab gGmbH, Germany.
    Krupinski, M.
    NaMLab gGmbH, Germany.
    Mikolajick, T.
    NaMLab gGmbH, Germany; Technical University of Dresden, Germany.
    Habel, F.
    Freiberger Compound Mat GmbH, Germany.
    Leibiger, G.
    Freiberger Compound Mat GmbH, Germany.
    Heitmann, J.
    TU Bergakad Freiberg, Germany.
    Origin of orange color in nominally undoped HVPE GaN crystals2017In: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 70, p. 127-130Article in journal (Refereed)
    Abstract [en]

    In this article we investigated unintentionally doped (UID) GaN grown by hydride vapor phase epitaxy (HVPE) with respect to point defects and impurity concentration. The samples were orange tinted to different extent. Optical analysis was performed by micro-photoluminescence and absorption spectroscopy. Absorption measurements revealed an absorption peak at 1.5 eV related to an internal transition in Mn3+ impurities and a second band with low energy onset at 1.9 eV, both increasing with the extent of orange color. Electron paramagnetic resonance investigations showed the presence of Mn2+ and Fe3+ in the colored crystals. The overall impurity concentration was verified by secondary ion mass spectrometry. Orange tint is associated with an increase of transition metal contamination, especially Mn. Based on these observations we suggest that the orange coloring in the investigated UID HVPE GaN samples is caused by the presence of Mn impurities. (C) 2017 Elsevier B.V. All rights reserved.

  • 101740.
    Zimmermann, Jay
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Updating an Android Cloud Storage Solutionfrom an Existing iOS Application2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Android and iOS are two of the leading smart phone and mobile device operating systems on the present market. Both of these platforms support third party application development. Cloud storage involves storing and accessing data online.

    The goal of this project involved helping a cloud storage company, with an existing iOS application and a less developed Android application, to update the Android application and simultaneously develop both applications. In addition to producing functionality in the applications it was the goal of this project to determine methods that would be useful in further updating and production of new functionality.

    While a wide range of tools exist aimed at helping cross platform development none of the frameworks examined fit the requirements of this project. As a result development was done natively on each platform. Attempts were made to translate the iOS code line by line and to simply build from an outline of the iOS functionality.

    During this process a number of tools that could replace each other on each device were determined. Additionally a number of the challenges in translating between operating systems were discussed. Finally while translating functionality line by line proved ineffective, it was found that noting down some aspects of the iOS code structure and some server call code could be useful for Android development when one was familiar with the iOS code.

  • 101741.
    Zimmermann, U
    et al.
    Royal Inst Technol, Dept Microelect & Informat Technol, SE-16440 Kista, Sweden Linkoping Univ, Dept Phys & Measurement Technol, S-58183 Linkoping, Sweden.
    Osterman, J
    Royal Inst Technol, Dept Microelect & Informat Technol, SE-16440 Kista, Sweden Linkoping Univ, Dept Phys & Measurement Technol, S-58183 Linkoping, Sweden.
    Zhang, J
    Henry, Anne
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Hallen, A
    Royal Inst Technol, Dept Microelect & Informat Technol, SE-16440 Kista, Sweden Linkoping Univ, Dept Phys & Measurement Technol, S-58183 Linkoping, Sweden.
    Electrical characterization of high-voltage 4H-SiC diodes on high-temperature CVD-grown epitaxial layers2002In: Materials Science Forum, Vols. 389-393, 2002, Vol. 389-3, p. 1285-1288Conference paper (Refereed)
    Abstract [en]

    High-temperature chemical vapour deposition (HTCVD) in a vertical chimney reactor was used to grow thick low-doped epitaxial layers of 4H silicon carbide. These layers were used as drift layers in a combined process to manufacture both bipolar and unipolar high-voltage diodes. The resulting diodes were characterized electrically in order to gain knowledge about the electric quality of the HTCVD epitaxial layers to assess the high-voltage properties of this material.

  • 101742.
    Zink, Bjørn-Henrik
    Linköping University, Department of Management and Economics.
    Strategic Determinants in the Software Industry: a study of six software companies in Sweden2003Independent thesis Advanced level (degree of Magister)Student thesis
    Abstract [en]

    Background: The software industry is being described as an industry of fierce competition and rapid technology change. The innovation pace is said to be so high that today's new technology might be history tomorrow. Where do the companies of the software industry focus when making strategic decisions? According to the strategic literature, a firm can focus on either the external environment or the internal environment as strategic starting points.

    Purpose: The purpose of this thesis is to find out what determines the strategy of firms in the software industry.

    Procedure: Interviews with six software companies in Sweden.

    Result: Four strategic determinants were identified: Flexible software solution, Markets that fit the software solution, Market Segmentation, Customers within the market segment. In this way, both the internal and external environment determines the strategies of the software companies.

  • 101743.
    Zinko, Heimo
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Mindre koldioxid med solvärme2005In: Energimagasinet : teknik, ekonomi, miljö, ISSN 0348-9493, Vol. 7, p. 26-30Article in journal (Other (popular science, discussion, etc.))
  • 101744.
    Zinko, Heimo
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Solar energy in a deregulated European energy system2006In: International Symposium,2006, 2006Conference paper (Refereed)
    Abstract [en]

       

  • 101745.
    Zinko, Heimo
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    The role of solar energy in the light of a deregulated European energy system2005In: ISES-Conference,2005, 2005Conference paper (Refereed)
  • 101746.
    Zinko, Heimo
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Gebremedhin, Alemayehu
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Klasson, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Reduction of CO2 emissions in district heating areas2008In: 10th World Renewable Energy Congress WRECX,2008, 2008, p. 2675-2680Conference paper (Refereed)
  • 101747.
    Zinko, Heimo
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Söderberg, Sven-Olof
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Fahlén, Elsa
    Gebremedhin, Alemayehu
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Energy Systems.
    Integration av absorptionsmaskiner i fjärrvärmesystem2004Report (Other academic)
  • 101748.
    Zinner, Christoph
    et al.
    University of Wurzburg, Germany; Mid Sweden University, Sweden.
    Morales-Alamo, David
    University of Las Palmas Gran Canaria, Spain; University of Las Palmas Gran Canaria, Spain.
    Ortenblad, Niels
    Mid Sweden University, Sweden; University of Southern Denmark, Denmark.
    Larsen, Filip J.
    Swedish School Sport and Health Science, Sweden.
    Schiffer, Tomas
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Willis, Sarah J.
    Mid Sweden University, Sweden.
    Gelabert-Rebato, Miriam
    University of Las Palmas Gran Canaria, Spain; University of Las Palmas Gran Canaria, Spain.
    Perez-Valera, Mario
    University of Las Palmas Gran Canaria, Spain; University of Las Palmas Gran Canaria, Spain.
    Boushel, Robert
    University of British Columbia, Canada.
    Calbet, Jose A. L.
    University of Las Palmas Gran Canaria, Spain; University of Las Palmas Gran Canaria, Spain; University of British Columbia, Canada.
    Holmberg, Hans-Christer
    Mid Sweden University, Sweden; University of British Columbia, Canada; UiT Arctic University of Norway, Norway.
    The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans2016In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 7, no 426Article in journal (Refereed)
    Abstract [en]

    To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 x 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO(2)peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training. VO(2)peak and Wmax increased 3-11% after training, with a more pronounced change in the arms (P amp;lt; 0.05). Gross efficiency improved for the arms (+8.8%, P amp;lt; 0.05), but not the legs (-0.6%). Wingate peak and mean power outputs improved similarly for the arms and legs, as did TT performance. After training, VO2 during the two Wingate tests was increased by 52 and 6% for the arms and legs, respectively (P amp;lt; 0.001). In the case of the arms, VO2 was higher during the first than second Wingate test (64 vs. 44%, P amp;lt; 0.05). During the TT, relative exercise intensity, HR, VO2, VCO2, V-E, and V-t were all lower during arm-cranking than leg-pedaling, and oxidation of fat was minimal, remaining so after training. Despite the higher relative intensity, fat oxidation was 70% greater during leg-pedaling (P = 0.017). The aerobic energy contribution in the legs was larger than for the arms during the Wingate tests, although VO2 for the arms was enhanced more by training, reducing the O-2 deficit after SIT. The levels of muscle glycogen, as well as the myosin heavy chain composition were unchanged in both cases, while the activities of 3-hydroxyacyl-CoA-dehydrogenase and citrate synthase were elevated only in the legs and capillarization enhanced in both limbs. Multiple regression analysis demonstrated that the variables that predict TT performance differ for the arms and legs. The primary mechanism of adaptation to SIT by both the arms and legs is enhancement of aerobic energy production. However, with their higher proportion of fast muscle fibers, the arms exhibit greater plasticity.

  • 101749.
    Zins, Matthieu
    Linköping University, Department of Electrical Engineering, Computer Vision.
    Color Fusion and Super-Resolution for Time-of-Flight Cameras2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The recent emergence of time-of-flight cameras has opened up new possibilities in the world of computer vision. These compact sensors, capable of recording the depth of a scene in real-time, are very advantageous in many applications, such as scene or object reconstruction. This thesis first addresses the problem of fusing depth data with color images. A complete process to combine a time-of-flight camera with a color camera is described and its accuracy is evaluated. The results show that a satisfying precision is reached and that the step of calibration is very important.

    The second part of the work consists of applying super-resolution techniques to the time-of-flight camera in order to improve its low resolution. Different types of super-resolution algorithms exist but this thesis focuses on the combination of multiple shifted depth maps. The proposed framework is made of two steps: registration and reconstruction. Different methods for each step are tested and compared according to the improvements reached in term of level of details, sharpness and noise reduction. The results obtained show that Lucas-Kanade performs the best for the registration and that a non-uniform interpolation gives the best results in term of reconstruction. Finally, a few suggestions are made about future work and extensions for our solutions.

  • 101750.
    Ziparo, V. A.
    et al.
    University of Rome “Sapienza”.
    Kleiner, Alexander
    University of Freiburg.
    Farinelli, A.
    University of Rome “Sapienza”.
    Marchetti, L.
    University of Rome “Sapienza”.
    Nardi, D.
    University of Rome “Sapienza”.
    Cooperative Exploration for USAR Robots with Indirect Communication2007In: Proc. of 6th IFAC Symposium on Intelligent Autonomous Vehicles (IAV), 2007Conference paper (Refereed)
    Abstract [en]

    To coordinate a team of robots for exploration is a challenging problem, particularly in unstructured areas, as for example post-disaster scenarios where direct communication is severely constrained. Furthermore, conventional methods of SLAM, e.g. those performing data association based on visual features, are doomed to fail due to bad visibility caused by smoke and fire. We use indirect communication (based on RFIDs), to share knowledge and use a gradient-like local search to direct robots towards interesting areas. To share a common frame of reference among robots we use a feature based SLAM approach (where features are RFIDs). The approach has been evaluated on a 3D simulation based on USARSim.

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