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  • 51.
    Aarsand, P.A.
    Linköpings universitet, Institutionen för beteendevetenskap och lärande. Linköpings universitet, Filosofiska fakulteten.
    Frame switches and identity performances: Alternating between online and offline2008Ingår i: Text and Talk, ISSN 1860-7330, Vol. 28, nr 2, s. 147-165Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study problematizes activity frames and participation frameworks (Goffman 1981), exploring how students deploy online (MSN Messenger) and offline activity frames in identity performances. One problem in analyzing participation frameworks and particularly notions of subordinate forms, like crossplay, byplay, and sideplay, is that these concepts require that the analyst can identify one dominant activity. This was not possible in the present data, which consist of video recordings of computer activities in a seventh-grade classroom. It is shown how MSN (online) identities were invoked in subsequent and intermittent face-to-face interaction, a dialogue that started on MSN would continue in face-to-face interaction, and vice versa. This means that frame switches constituted important features of the students' identity work. Similarly, the students employed nicknames or what are here called tags, that is, textual-visual displays of speaker identities, located in the boundary zone between online and offline activities. In the classroom interactions, there was thus not one dominant activity frame, but rather the activities involved borderwork, and more specifically frame switches and a strategic use of tags. © Walter de Gruyter 2008.

  • 52.
    Aarsand, Pål André
    Linköpings universitet, Institutionen för tema, Tema Barn. Linköpings universitet, Filosofiska fakulteten.
    Alternating between online and offline: tags and frame switches as interactional resources2007Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The present data are based on an ethnographic study of computer use in everyday interactions in a seventh grade class (of 13-14 year-olds). The data were analysed in terms of activity frames and participation frameworks (Goffman 1981), exploring how students deployed online and offline activity frames in their identity performance. It is shown how MSN (online) identities are invoked in subsequent and intermittent face-to-face interaction; a dialogue can start on MSN and continue in faceto-face interaction, and vice versa. This means that frame switches are important features of the students’ identity work. Similarly, the students employed nicknames or tags, that is, textual-visual displays of ‘speaker’ identities, located in the boundary zone between online and offline activities. In terms of participation frameworks, it is also documented ways in which students engaged in crossplay (Goffman 1981), where a ratified participant communicated with a non-ratified participant. Yet, one problem in analysing participation frameworks and particularly byplay and sideplay (Goffman 1981) is that these concepts require that the analyst can identify one dominant activity. This was not possible in the present data. Instead, the data are primarily analysed in terms of borderwork, that here entails frame switchings, crossplay and a strategic use of tags.

  • 53. Beställ onlineKöp publikationen >>
    Aarsand, Pål André
    Linköpings universitet, Institutionen för tema, Tema Barn. Linköpings universitet, Filosofiska fakulteten.
    Around the Screen: Computer activities in children’s everyday lives2007Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The present ethnography documents computer activities in everyday life. The data consist of video recordings, interviews and field notes, documenting (i) 16 students in a seventh grade class in a computer room and other school settings and (ii) 22 children, interacting with siblings, friends and parents in home settings. The thesis is inspired by discourse analytical as well as ethnographic approaches, including notions from Goffman (1974, 1981), e.g. those of activity frame and participation framework, which are applied and discussed.

    The thesis consists of four empirical studies. The first study focuses on students’ illegitimate use, from the school’s point of view, of online chatting in a classroom situation. It is shown that the distinction offline/online is not a static one, rather it is made relevant as part of switches between activity frames, indicating the problems of applying Goffman’s (1981) notions of sideplay, byplay and crossplay to analyses of interactions in which several activity frames are present, rather than one main activity. Moreover, it is shown that online identities, in terms of what is here called tags, that is, visual-textual nicknames, are related to offline phenomena, including local identities as well as contemporary aesthetics. The second study focuses on placement of game consoles as part of family life politics. It is shown that game consoles were mainly located in communal places in the homes. The distinction private/communal was also actualized in the participants’ negotiations about access to game consoles as well as negotiations about what to play, when, and for how long. It is shown that two strategies were used, inclusion and exclusion, for appropriating communal places for computer game activities. The third study focuses on a digital divide in terms of a generational divide with respect to ascribed computer competence, documenting how the children and adults positioned each other as people ‘in the know’ (the children) versus people in apprentice-like positions (the adults). It is shown that this generation gap was deployed as a resource in social interaction by both the children and the adults. The forth study focuses on gaming in family life, showing that gaming was recurrently marked by response cries (Goffman, 1981) and other forms of blurted talk. These forms of communication worked as parts of the architecture of intersubjectivity in gaming (cf. Heritage, 1984), indexing the distinction virtual/‘real’. It is shown how response cries, sound making, singing along and animated talk extended the virtual in that elements of the game became parts of the children’s social interaction around the screen, forming something of an action aesthetic, a type of performative action for securing and displaying joint involvement and collaboration. As a whole, the present studies show how the distinctions master/apprentice, public/private, virtual/real and subject/object are indexicalized and negotiated in computer activities.

    Delarbeten
    1. Alternating between online and offline: tags and frame switches as interactional resources
    Öppna denna publikation i ny flik eller fönster >>Alternating between online and offline: tags and frame switches as interactional resources
    2007 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The present data are based on an ethnographic study of computer use in everyday interactions in a seventh grade class (of 13-14 year-olds). The data were analysed in terms of activity frames and participation frameworks (Goffman 1981), exploring how students deployed online and offline activity frames in their identity performance. It is shown how MSN (online) identities are invoked in subsequent and intermittent face-to-face interaction; a dialogue can start on MSN and continue in faceto-face interaction, and vice versa. This means that frame switches are important features of the students’ identity work. Similarly, the students employed nicknames or tags, that is, textual-visual displays of ‘speaker’ identities, located in the boundary zone between online and offline activities. In terms of participation frameworks, it is also documented ways in which students engaged in crossplay (Goffman 1981), where a ratified participant communicated with a non-ratified participant. Yet, one problem in analysing participation frameworks and particularly byplay and sideplay (Goffman 1981) is that these concepts require that the analyst can identify one dominant activity. This was not possible in the present data. Instead, the data are primarily analysed in terms of borderwork, that here entails frame switchings, crossplay and a strategic use of tags.

    Nyckelord
    participation framework, activity frames, online activities, offline activities, identities, borderwork.
    Nationell ämneskategori
    Övrig annan samhällsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-14501 (URN)
    Tillgänglig från: 2007-05-14 Skapad: 2007-05-14 Senast uppdaterad: 2010-10-11
    2. Gaming and Territorial Negotiations in Family Life
    Öppna denna publikation i ny flik eller fönster >>Gaming and Territorial Negotiations in Family Life
    2009 (Engelska)Ingår i: Childhood, ISSN 0907-5682, E-ISSN 1461-7013, Vol. 16, nr 4, s. 497-517Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    This article examines territorial negotiations concerning gaming, drawing on video recordings of gaming practices in middle-class families. It explores how private vs public gaming space was co-construed by children and parents in front of the screen as well as through conversations about games. Game equipment was generally located in public places in the homes, which can be understood in terms of parents’ surveillance of their children, on the one hand, and actual parental involvement, on the other. Gaming space emerged in the interplay between game location, technology and practices, which blurred any fixed boundaries between public and private, place and space, as well as traditional age hierarchies.

    Nyckelord
    computer gaming • family politics • parental involvement • place/space • public/private
    Nationell ämneskategori
    Övrig annan samhällsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-14502 (URN)10.1177/0907568209343879 (DOI)
    Anmärkning
    Tidigare titel: Computer gaming and territorial negotiations in family life Tillgänglig från: 2007-05-14 Skapad: 2007-05-14 Senast uppdaterad: 2017-12-13
    3. Computer- and Video games in Family Life: The digital divide as a resource in intergenerational interactions
    Öppna denna publikation i ny flik eller fönster >>Computer- and Video games in Family Life: The digital divide as a resource in intergenerational interactions
    2007 (Engelska)Ingår i: Childhood, ISSN 0907-5682, Vol. 14, nr 2, s. 235-256Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In this ethnographic study of family life, intergenerational video and computer game activities were videotaped and analysed. Both children and adults invoked the notion of a digital divide, i.e. a generation gap between those who master and do not master digital technology. It is argued that the digital divide was exploited by the children to control the game activities. Conversely, parents and grandparents positioned themselves as less knowledgeable, drawing on a displayed divide as a rhetorical resource for gaining access to playtime with the children. In these intergenerational encounters, the digital divide was thus an interactional resource rather than a problem.

    Nyckelord
    computer games, digital divide, family, knowledge-relations, participation framework, video games
    Nationell ämneskategori
    Övrig annan samhällsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-14503 (URN)10.1177/0907568207078330 (DOI)
    Tillgänglig från: 2007-05-14 Skapad: 2007-05-14 Senast uppdaterad: 2009-04-21
    4. Response cries and other gaming moves: Building intersubjectivity in gaming
    Öppna denna publikation i ny flik eller fönster >>Response cries and other gaming moves: Building intersubjectivity in gaming
    2009 (Engelska)Ingår i: Journal of Pragmatics, ISSN 0378-2166, Vol. 41, nr 8, s. 1557-1575Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The present study focuses on the ways in which response cries (Goffman, 1981) are deployed as interactional resources in computer gaming in everyday life. It draws on a large-scale data set of video recordings of the everyday lives of middleclass families. The recordings of gaming between children and between children and parents show that response cries were not arbitrarily located within different phases of gaming (planning, gaming or commenting on gaming). Response cries were primarily used as interactional resources for securing and sustaining joint attention (cf. Goodwin, 1996) during the gaming as such, that is, during periods when the gaming activity was characterized by a relatively high tempo. In gaming between children, response cries co-occurred with their animations of game characters and with sound making, singing along, and code switching in ways that formed something of an action aesthetic, a type of aesthetic that was most clearly seen in gaming between game equals (here: between children). In contrast, response cries were rare during the planning phases and during phases in which the participants primarily engaged in setting up or adjusting the game.

    Nyckelord
    Computer gaming; Response cries; Intersubjectivity; Everyday life; Action aesthetic
    Nationell ämneskategori
    Övrig annan samhällsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-14504 (URN)10.1016/j.pragma.2007.05.014 (DOI)
    Tillgänglig från: 2007-05-14 Skapad: 2007-05-14 Senast uppdaterad: 2010-02-05
    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 54.
    Aarsand, Pål André
    Linköpings universitet, Institutionen för tema, Tema Barn. Linköpings universitet, Filosofiska fakulteten.
    Computer- and Video games in Family Life: The digital divide as a resource in intergenerational interactions2007Ingår i: Childhood, ISSN 0907-5682, Vol. 14, nr 2, s. 235-256Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this ethnographic study of family life, intergenerational video and computer game activities were videotaped and analysed. Both children and adults invoked the notion of a digital divide, i.e. a generation gap between those who master and do not master digital technology. It is argued that the digital divide was exploited by the children to control the game activities. Conversely, parents and grandparents positioned themselves as less knowledgeable, drawing on a displayed divide as a rhetorical resource for gaining access to playtime with the children. In these intergenerational encounters, the digital divide was thus an interactional resource rather than a problem.

  • 55.
    Aarsand, Pål André
    et al.
    Linköpings universitet, Institutionen för tema, Tema Barn. Linköpings universitet, Filosofiska fakulteten.
    Aronsson, Karin
    Linköpings universitet, Institutionen för tema, Tema Barn. Linköpings universitet, Filosofiska fakulteten.
    Response cries and other gaming moves: Building intersubjectivity in gaming2009Ingår i: Journal of Pragmatics, ISSN 0378-2166, Vol. 41, nr 8, s. 1557-1575Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study focuses on the ways in which response cries (Goffman, 1981) are deployed as interactional resources in computer gaming in everyday life. It draws on a large-scale data set of video recordings of the everyday lives of middleclass families. The recordings of gaming between children and between children and parents show that response cries were not arbitrarily located within different phases of gaming (planning, gaming or commenting on gaming). Response cries were primarily used as interactional resources for securing and sustaining joint attention (cf. Goodwin, 1996) during the gaming as such, that is, during periods when the gaming activity was characterized by a relatively high tempo. In gaming between children, response cries co-occurred with their animations of game characters and with sound making, singing along, and code switching in ways that formed something of an action aesthetic, a type of aesthetic that was most clearly seen in gaming between game equals (here: between children). In contrast, response cries were rare during the planning phases and during phases in which the participants primarily engaged in setting up or adjusting the game.

  • 56.
    Aarsand, Pål
    et al.
    Department of Education and Life long learning, Norweigan University Of Science and Technology, Trondheim, Norway.
    Sparrman, Anna
    Linköpings universitet, Institutionen för tema, Tema Barn. Linköpings universitet, Filosofiska fakulteten.
    Visual transcriptions as socio-technical assemblages2021Ingår i: Visual Communication, ISSN 1470-3572, E-ISSN 1741-3214, Vol. 20, nr 2, s. 289-309Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the development of visual digital technologies it has become more common in the social sciences to both use and present research visually. This article explores different strategies for working with and including images in ethnomethodology and conversation analysis (EMCA) transcriptions. The purpose is to investigate how, and if, the ontology of the transcript changes when verbal transcripts become visual transcripts. The article explores what ensures that a transcript is still a transcript and what happens to the reflexive interpretative strategy fundamental to EMCA when new digital technologies make it possible to incorporate images in transcripts. The articles focus is on the social life of methods as well as methodological productivity showing how images can enact different social realities and scientific knowledge.

  • 57.
    Aarts, B.
    et al.
    Netherlands Forensic Institute, Biological Traces and DNA, The Hague, Netherlands.
    Kokshoorn, B.
    Netherlands Forensic Institute, Biological Traces and DNA, The Hague, Netherlands.
    Mc Kenna, L.G.
    Forensic Science Ireland, DNA department, Dublin, Ireland.
    Drotz, W.
    Swedish National Forensic Centre, DNA department, Linköping, Sweden.
    Ansell, Ricky
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Swedish National Forensic Centre, DNA department, Linköping, Sweden.
    van Oorschot, R.A.
    Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Macleod- Victoria, Australia.
    Kloosterman, A.D.
    Netherlands Forensic Institute, Biological Traces and DNA, The Hague, Netherlands.
    DNActivity: International cooperation in activity level interpretation of forensic DNA evidence.2015Ingår i: Abstract book, 7th European Academy of Forensic Science, EAFS, Prag, Tjeckien, 2015., 2015, s. 555-Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Questions posed to expert witnesses by the legal community and the courts are expanding to include not just those relating to source level (i.e. ‘who is the donor of the trace?’) but also those relating to activitity level (i.e. ‘how did the DNA get there?’). The answers to these questions are usually formulated as the probability of the evidence under alternative scenarios. As activity level questions are part of investigative and legal considerations it is of paramount importance that expert witnesses are provided with knowledge and tools to address these questions.

    To answer such questions within a probabilistic framework, empirical data is needed to estimate probabilities of transfer, persistence and recovery of DNA as well as background levels of DNA on everyday objects. There is a paucity of empirical data on these topics, but the number of studies is increasing both through in-house experiments and experimental data published in international scientific journals.

    Laboratories that conduct such studies all use different experimental setups, trace recovery strategies and techniques and DNA analysis systems and equipment. It is essential for the forensic genetics community in general to establish whether the data generated by different labs are in concordance, and can therefore be readily used by the forensic community.

    Moreover, if existing data and data generated from future experiments are made available to the (forensic) community, knowledge is needed on the key factors that underlie potential interlaboratory variation.

    The aims and objectives of this ENFSI Monopoly 2013 project are to conduct a study of methodologies and data from different laboratories and to assess the comparability of the scientific data on transfer, persistence and recovery of DNA. This comparison will allow us to identify key factors that underlie potential variation. This information will be used to setup guidelines to enable sharing and database-storage of relevant scientific

    data. This will improve the ability of forensic scientists and other professionals of the Criminal Justice System to give evidence-based answers to questions that relate to the activity level of the crime under investigation.

  • 58.
    Aartsen, Marja
    et al.
    Oslo Metropolitan University, Norway.
    Walsh, Kieran
    National University of Ireland Galway, Ireland.
    Löwenstein, Ariela
    Haifa University, Israel.
    Katz, Ruth
    University of Haifa, Israel.
    Naim, Sigal Pearl
    Yezreel Academic College, Israel.
    Motel-Klingebiel, Andreas
    Linköpings universitet, Institutionen för kultur och samhälle, Avdelningen för åldrande och social förändring. Linköpings universitet, Filosofiska fakulteten.
    Wanka, Anna
    Goethe University in Frankfurt am Main, Germany; University of Stuttgart, Germany..
    Urbaniak, Anna
    University of Vienna, Austria.
    Hansen, Thomas
    Oslo Metropolitan University, Norway.
    Vidovićová, Lucie
    Masaryk University, Tjeckien.
    Exclusion from Social Relations in Later Lifeand the Role of Gender: A Heuristic Model2021Ingår i: Gender and Research, ISSN 2570-6578, Vol. 22, nr 1, s. 16-35Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Being socially connected is a universal human need, but a substantial number ofolder men and women are or become excluded from these connections in later life. Exclusionfrom social relations (ESR) is unwanted as it undermines people’s ability to lead a healthy,active, and independent life. Policies to reduce this form of exclusion have been limited ineffectiveness, due in part to a broader lack of knowledge about the dynamics of socialexclusion in older ages and the intersection of social exclusion with gender constructions. Toadvance our understanding of ESR in later life, we develop a heuristic model based on theoriesand previous empirical studies. Considering the gendered constructing forces of ESR in olderage that can potentially lead to loneliness and reduced health and wellbeing, the modelidentifies individual drivers, such as biopsychosocial conditions, personal standards and life--course transitions, and macro-level drivers, such as norms and welfare state provisions. Thismodel can serve as a conceptual platform for further theoretical development and empiricalstudy on the gendered construction of ESR in later life. While our focus is on drivers of ESRand its outcomes, potential reversed effects are also discussed.

    Ladda ner fulltext (pdf)
    fulltext
  • 59.
    Aasa, Agneta
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Omvårdnad. Linköpings universitet, Hälsouniversitetet.
    Hovbäck, Malin
    Linköpings universitet, Institutionen för medicin och hälsa, Omvårdnad. Linköpings universitet, Hälsouniversitetet.
    Det preoperativa informationssamtalets betydelse för patientens delaktighet i sin vård inom kolorektalkirurgi2011Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Bakgrund: ERAS (Enhanced Recovery After Surgery) är ett standardiserat multimodalt vårdprogram vid elektiv kolorektalkirurgi, som syftar till snabbare återhämtning och kortare vårdtider genom ett tvärprofessionellt samarbete.  En vecka innan planerad operation träffar sjuksköterskan patienten för ett samtal om vårdförloppet.

     

    Syfte: Att identifiera och beskriva patientens upplevelse av sjuksköterskans ERAS- samtal och dess betydelse för patientens delaktighet i sin vård. 

     

    Metod: Datainsamlingen skedde genom kvalitativa intervjuer. Tolv patienter, nio män och tre kvinnor har intervjuats. De ljudinspelade samtalen har transkriberats ordagrant och analyserats med hjälp av tolkande fenomenologisk analys (Interpretative Phenomenological Analysis).

     

    Resultat: Analysarbetet resulterade i fem olika teman; bli sedd, trygghet, tillit, ansvar samt delaktighet. Alla teman relaterar till varandra och illustrerar en positiv och en negativ sida av den upplevda erfarenheten. Tillsammans bildar en helhet av upplevelsen; ERAS- samtalet och dess betydelse för patientens delaktighet.

     

    Konklusion: Resultatet visar att patienterna känner sig sedda under informationssamtalet. Det är viktigt att bekräfta patienten och knyta an mer till informationssamtalet under vårdtiden för att patienterna ska vara delaktiga och ta eget ansvar. Tilliten till vårdpersonalen har betydelse för att patienterna ska känna trygghet. Studien visar att ERAS- samtalet upplevs strukturerat och individuellt men informationen måste följa patienterna under hela vårdtillfället.

    Ladda ner fulltext (pdf)
    magisteruppsats
  • 60.
    Aasa, Agneta
    et al.
    Kirurgmottagningen, Ryhovs Länssjukhus, Jönköping, Sweden.
    Hovbäck, Malin
    Kirurgmottagningen, Ryhovs Länssjukhus, Jönköping, Sweden.
    Berterö, Carina
    Linköpings universitet, Institutionen för medicin och hälsa, Omvårdnad. Linköpings universitet, Hälsouniversitetet.
    The importance of preoperative information for patient participation in colorectal surgery care2013Ingår i: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 22, nr 11-12, s. 1604-1612Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aims and objectives

    To identify and describe patients' experiences of a preoperative information session with a nurse, as part of the enhanced recovery after surgery (ERAS) concept, and its impact on patient participation in their own care.

    Background

    Enhanced recovery after surgery is a standardised, multimodal treatment programme for elective colorectal surgery, leading to faster recovery and shorter hospital stays via interprofessional collaboration. The ERAS concept is initiated for patients a week before surgery when the patient receives detailed information about the care process during a meeting with a nurse.

    Design

    The study is a qualitative interpretive study based on interviews.

    Methods

    Twelve patients, nine men and three women, were interviewed. The interviews were transcribed verbatim and analysed using interpretive phenomenological analysis (IPA).

    Results

    The analysis identified and formulated five themes: being seen, security, trust, responsibility and participation. All themes are closely related and illustrate positive and negative sides of the patient's experience. They hang together and form a complete set of experiences: ERAS conversation and its impact on patients' participation.

    Conclusions

    The results show that patients feel confirmed in the ERAS conversation. Healthcare professionals need to be bonding more information call during hospitalisation. It is important to confirm the patient in order for them to participate and take responsibility. Reliance on caregivers is important for patients to feel safe and to participate in their own care. This study shows that the ERAS conversation was experienced as being structured and individually tailored, but the information must apply to the patients throughout the period of care.

    Relevance to clinical practice

    Some shortcomings have been revealed, which should enable improvement in the care of patients. Healthcare professionals need to raise awareness of patients' responsibilities for participation in their own recovery and care. Healthcare professionals and patients need to be aware of each other's responsibilities.

    Ladda ner fulltext (pdf)
    fulltext
  • 61.
    Aasa, Amanda
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniska Kretsar och System.
    Svennblad, Amanda
    Linköpings universitet, Institutionen för systemteknik, Elektroniska Kretsar och System.
    Design of an Automated Test Setup for Power-Controlled Nerve Stimulator Using NFC for Implantable Sensors2021Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Electrical stimulation on nerves is a relatively new area of research and has been proved to speed up recoveryfrom nerve damage. In this work, the efficiency and stability of antennas integrated on printed circuit boards provided by the department of electrical engineering are examined. An automated test bench containing a stepmotor with a slider and an Arduino is created. Different setups were used when measuring on the boards, which resulted in that the largest antenna gave the most stable output despite the distance between transmitterand receiver. The conclusion was that the second best antenna and the smallest one would be suitable as well,and the better choice if it is to be implemented under the skin. A physical setup consisting of LEDs, an Arduino, a computer, and a function generator was created to examinethe voltage control functionality, where colored LEDs were lit depending on the voltage level. The functionality was then implemented in a circuit that in the future shall be integrated on the printed circuit board. To control high voltages a limiter circuit was examined and implemented. The circuit was simulated and tested, with a realization that a feature covering voltage enlargement is needed for the future. 

    Ladda ner fulltext (pdf)
    fulltext
  • 62.
    Aasa, Mikael
    et al.
    Karolinska Institute.
    Henriksson, Martin
    Linköpings universitet, Institutionen för medicin och hälsa, Utvärdering och hälsoekonomi. Linköpings universitet, Hälsouniversitetet.
    Dellborg, Mikael
    Gothenburg University.
    Grip, Lars
    Gothenburg University.
    Herlitz, Johan
    Gothenburg University.
    Levin, Lars-Åke
    Linköpings universitet, Institutionen för medicin och hälsa, Utvärdering och hälsoekonomi. Linköpings universitet, Hälsouniversitetet.
    Svensson, Leif
    Stockholm Prehospital Centre.
    Janzon, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Cost and health outcome of primary percutaneous coronary intervention versus thrombolysis in acute ST-segment elevation myocardial infarction-Results of the Swedish Early Decision reperfusion Study (SWEDES) trial2010Ingår i: AMERICAN HEART JOURNAL, ISSN 0002-8703, Vol. 160, nr 2, s. 322-328Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background In ST-elevation myocardial infarction, primary percutaneous coronary intervention (PCI) has a superior clinical outcome, but it may increase costs in comparison to thrombolysis. The aim of the study was to compare costs, clinical outcome, and quality-adjusted survival between primary PCI and thrombolysis. Methods Patients with ST-elevation myocardial infarction were randomized to primary PCI with adjunctive enoxaparin and abciximab (n = 101), or to enoxaparin followed by reteplase (n = 104). Data on the use of health care resources, work loss, and health-related quality of life were collected during a 1-year period. Cost-effectiveness was determined by comparing costs and quality-adjusted survival. The joint distribution of incremental costs and quality-adjusted survival was analyzed using a nonparametric bootstrap approach. Results Clinical outcome did not differ significantly between the groups. Compared with the group treated with thrombolysis, the cost of interventions was higher in the PCI-treated group ($4,602 vs $3,807; P = .047), as well as the cost of drugs ($1,309 vs $1,202; P = .001), whereas the cost of hospitalization was lower ($7,344 vs $9,278; P = .025). The cost of investigations, outpatient care, and loss of production did not differ significantly between the 2 treatment arms. Total cost and quality-adjusted survival were $25,315 and 0.759 vs $27,819 and 0.728 (both not significant) for the primary PCI and thrombolysis groups, respectively. Based on the 1-year follow-up, bootstrap analysis revealed that in 80%, 88%, and 89% of the replications, the cost per health outcome gained for PCI will be andlt;$0, $50,000, and $100,000 respectively. Conclusion In a 1-year perspective, there was a tendency toward lower costs and better health outcome after primary PCI, resulting in costs for PCI in comparison to thrombolysis that will be below the conventional threshold for cost-effectiveness in 88% of bootstrap replications.

  • 63.
    Aase, Audun
    et al.
    Norwegian Institute Public Heatlh, Norway.
    Hajdusek, Ondrej
    Academic Science Czech Republic, Czech Republic.
    Oines, Oivind
    Norwegian Vet Institute, Norway.
    Quarsten, Hanne
    Sorlandet Hospital Health Enterprise, Norway.
    Wilhelmsson, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Herstad, Tove K.
    Norwegian Institute Public Heatlh, Norway.
    Kjelland, Vivian
    University of Agder, Norway; Sorlandet Hospital Health Enterprise, Norway.
    Sima, Radek
    Academic Science Czech Republic, Czech Republic.
    Jalovecka, Marie
    Academic Science Czech Republic, Czech Republic.
    Lindgren, Per-Eric
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. County Hospital Ryhov, Sweden.
    Aaberge, Ingeborg S.
    Norwegian Institute Public Heatlh, Norway.
    Validate or falsify: Lessons learned from a microscopy method claimed to be useful for detecting Borrelia and Babesia organisms in human blood2016Ingår i: INFECTIOUS DISEASES, ISSN 2374-4235, Vol. 48, nr 6, s. 411-419Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background A modified microscopy protocol (the LM-method) was used to demonstrate what was interpreted as Borrelia spirochetes and later also Babesia sp., in peripheral blood from patients. The method gained much publicity, but was not validated prior to publication, which became the purpose of this study using appropriate scientific methodology, including a control group. Methods Blood from 21 patients previously interpreted as positive for Borrelia and/or Babesia infection by the LM-method and 41 healthy controls without known history of tick bite were collected, blinded and analysed for these pathogens by microscopy in two laboratories by the LM-method and conventional method, respectively, by PCR methods in five laboratories and by serology in one laboratory. Results Microscopy by the LM-method identified structures claimed to be Borrelia- and/or Babesia in 66% of the blood samples of the patient group and in 85% in the healthy control group. Microscopy by the conventional method for Babesia only did not identify Babesia in any samples. PCR analysis detected Borrelia DNA in one sample of the patient group and in eight samples of the control group; whereas Babesia DNA was not detected in any of the blood samples using molecular methods. Conclusions The structures interpreted as Borrelia and Babesia by the LM-method could not be verified by PCR. The method was, thus, falsified. This study underlines the importance of doing proper test validation before new or modified assays are introduced.

  • 64.
    Aaseth, Jan
    et al.
    Innlandet Hosp Trust, Norway.
    Alexander, Jan
    Norwegian Inst Publ Hlth, Norway.
    Alehagen, Urban
    Linköpings universitet, Institutionen för hälsa, medicin och vård, Avdelningen för diagnostik och specialistmedicin. Linköpings universitet, Medicinska fakulteten.
    Coenzyme Q(10) supplementation - In ageing and disease2021Ingår i: Mechanisms of Ageing and Development, ISSN 0047-6374, E-ISSN 1872-6216, Vol. 197, artikel-id 111521Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coenzyme Q(10) (CoQ(10)) is an essential component of the mitochondrial electron transport chain. It is also an antioxidant in cellular membranes and lipoproteins. All cells produce CoQ(10) by a specialized cytoplasmatic-mitochondrial pathway. CoQ(10) deficiency can result from genetic failure or ageing. Some drugs including statins, widely used by inter alia elderly, may inhibit endogenous CoQ(10) synthesis. There are also chronic diseases with lower levels of CoQ(10) in tissues and organs. High doses of CoQ(10) may increase both circulating and intracellular levels, but there are conflicting results regarding bioavailability. Here, we review the current knowledge of CoQ(10) biosynthesis and primary and acquired CoQ(10) deficiency, and results from clinical trials based on CoQ(10) supplementation. There are indications that supplementation positively affects mitochondrial deficiency syndrome and some of the symptoms of ageing. Cardiovascular disease and inflammation appear to be alleviated by the antioxidant effect of CoQ(10). There is a need for further studies and well-designed clinical trials, with CoQ(10) in a formulation of proven bioavailability, involving a greater number of participants undergoing longer treatments in order to assess the benefits of CoQ(10) treatment in neurodegenerative disorders, as well as in metabolic syndrome and its complications.

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  • 65.
    Aaseth, Jan
    et al.
    Innlandet Hosp, Norway; Inland Norway Univ Appl Sci, Norway.
    Alexander, Jan
    Norwegian Inst Publ Hlth, Norway.
    Alehagen, Urban
    Linköpings universitet, Institutionen för hälsa, medicin och vård, Avdelningen för diagnostik och specialistmedicin. Linköpings universitet, Medicinska fakulteten.
    Tinkov, Alexey
    Yaroslavl State Univ, Russia; IM Sechenov First Moscow State Med Univ Sechenov, Russia.
    Skalny, Anatoly
    IM Sechenov First Moscow State Med Univ Sechenov, Russia; KG Razumovsky Moscow State Univ Technol & Managem, Russia.
    Larsson, Anders
    Uppsala Univ, Sweden.
    Crisponi, Guido
    Univ Cagliari, Italy.
    Nurchi, Valeria Marina
    Univ Cagliari, Italy.
    The Aging Kidney - As Influenced by Heavy Metal Exposure and Selenium Supplementation2021Ingår i: Biomolecules, E-ISSN 2218-273X, Vol. 11, nr 8, artikel-id 1078Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The aging process in the kidneys has been well studied. It is known that the glomerular filtration rate (GFR) declines with age in subjects older than 50-60 years. However, there is still insufficient knowledge regarding the response of the aged kidney to environmental toxicants such as mercury, cadmium, and lead. Here, we present a review on the functional decline and proposed mechanisms in the aging kidney as influenced by metal pollutants. Due to the prevalence of these toxicants in the environment, human exposure is nearly unavoidable. Further, it is well known that acute and chronic exposures to toxic metals may be detrimental to kidneys of normal adults, thus it may be hypothesized that exposure of individuals with reduced GFR will result in additional reductions in renal function. Individuals with compromised renal function, either from aging or from a combination of aging and disease, may be particularly susceptible to environmental toxicants. The available data appear to show an association between exposure to mercury, cadmium and/or lead and an increase in incidence and severity of renal disease in elderly individuals. Furthermore, some physiological thiols, as well as adequate selenium status, appear to exert a protective action. Further studies providing improved insight into the mechanisms by which nephrotoxic metals are handled by aging kidneys, as well as possibilities of therapeutic protection, are of utmost importance.

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  • 66.
    Aaseth, Jan
    et al.
    Innlandet Hospital Trust, Norway; Hedmark University of Appl Science, Norway.
    Alexander, Jan
    Norwegian Institute Public Heatlh, Norway; Norwegian University of Life Science NMBU, Norway.
    Bjorklund, Geir
    Council Nutr and Environm Med, Norway.
    Hestad, Knut
    Innlandet Hospital Trust, Norway; Hedmark University of Appl Science, Norway.
    Dusek, Petr
    Charles University of Prague, Czech Republic; Charles University of Prague, Czech Republic; Gen University Hospital Prague, Czech Republic.
    Roos, Per M.
    Karolinska Institute, Sweden; St Goran Hospital, Sweden.
    Alehagen, Urban
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Treatment strategies in Alzheimers disease: a review with focus on selenium supplementation2016Ingår i: Biometals, ISSN 0966-0844, E-ISSN 1572-8773, Vol. 29, nr 5, s. 827-839Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alzheimers disease (AD) is a neurodegenerative disorder presenting one of the biggest healthcare challenges in developed countries. No effective treatment exists. In recent years the main focus of AD research has been on the amyloid hypothesis, which postulates that extracellular precipitates of beta amyloid (A beta) derived from amyloid precursor protein (APP) are responsible for the cognitive impairment seen in AD. Treatment strategies have been to reduce A beta production through inhibition of enzymes responsible for its formation, or to promote resolution of existing cerebral A beta plaques. However, these approaches have failed to demonstrate significant cognitive improvements. Intracellular rather than extracellular events may be fundamental in AD pathogenesis. Selenate is a potent inhibitor of tau hyperphosphorylation, a critical step in the formation of neurofibrillary tangles. Some selenium (Se) compounds e.g. selenoprotein P also appear to protect APP against excessive copper and iron deposition. Selenoproteins show anti-inflammatory properties, and protect microtubules in the neuronal cytoskeleton. Optimal function of these selenoenzymes requires higher Se intake than what is common in Europe and also higher intake than traditionally recommended. Supplementary treatment with N-acetylcysteine increases levels of the antioxidative cofactor glutathione and can mediate adjuvant protection. The present review discusses the role of Se in AD treatment and suggests strategies for AD prevention by optimizing selenium intake, in accordance with the metal dysregulation hypothesis. This includes in particular secondary prevention by selenium supplementation to elderly with mild cognitive impairment.

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  • 67.
    Aaseth, Jan
    et al.
    Innlandet Hosp, Norway; Inland Norway Univ Appl Sci, Norway.
    Ellefsen, Stian
    Inland Norway Univ Appl Sci, Norway.
    Alehagen, Urban
    Linköpings universitet, Institutionen för hälsa, medicin och vård, Avdelningen för diagnostik och specialistmedicin. Linköpings universitet, Medicinska fakulteten.
    Sundfor, Tine M.
    Oslo Univ Hosp, Norway.
    Alexander, Jan
    Norwegian Inst Publ Hlth, Norway.
    Diets and drugs for weight loss and health in obesity: An update2021Ingår i: Biomedicine and Pharmacotherapy, ISSN 0753-3322, E-ISSN 1950-6007, Vol. 140, artikel-id 111789Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Numerous combinations of diets and pharmacological agents, including lifestyle changes, have been launched to treat obesity. There are still ambiguities regarding the efficacies of different approaches despite many clinical trials and the use of animal models to study physiological mechanisms in weight management and obesity comorbidities, Here, we present an update on promising diets and pharmacological aids. Literature published after the year 2005 was searched in PubMed, Medline and Google scholar. Among recommended diets are low-fat (LF) and low-carbohydrate (LC) diets, in addition to the Mediterranean diet and the intermittent fasting approach, all of which presumably being optimized by adequate contents of dietary fibers. A basic point for weight loss is to adopt a diet that creates a permanently negative and acceptable energy balance, and prolonged dietary adherence is a crucial factor. As for pharmacological aids, obese patients with type 2 diabetes or insulin resistance seem to benefit from LC diet combined with a GLP-1 agonist, e.g. semaglutide, which may improve glycemic control, stimulate satiety, and suppress appetite. The lipase inhibitor orlistat is still used to maintain a low-fat approach, which may be favorable e.g. in hypercholesterolemia. The bupropion-naltrexone-combination appears promising for interruption of the vicious cycle of addictive over-eating. Successful weight loss seems to improve almost all biomarkers of obesity comorbidities. Until more support for specific strategies is available, clinicians should recommend an adapted lifestyle, and when necessary, a drug combination tailored to individual needs and comorbidities. Different diets may change hormonal secretion, gut-brain signaling, and influence hunger, satiety and energy expenditure. Further research is needed to clarify mechanisms and how such knowledge can be used in weight management.

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  • 68.
    Aaseth, Jan O.
    et al.
    Innlandet Hosp Trust, Norway; Inland Norway Univ Appl Sci, Norway.
    Alehagen, Urban
    Linköpings universitet, Institutionen för hälsa, medicin och vård, Avdelningen för diagnostik och specialistmedicin. Linköpings universitet, Medicinska fakulteten.
    Opstad, Trine Baur
    Oslo Univ Hosp Ullevaal, Norway; Univ Oslo, Norway.
    Alexander, Jan
    Norwegian Inst Publ Hlth, Norway.
    Vitamin K and Calcium Chelation in Vascular Health2023Ingår i: Biomedicines, E-ISSN 2227-9059, Vol. 11, nr 12, artikel-id 3154Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The observation that the extent of artery calcification correlates with the degree of atherosclerosis was the background for the alternative treatment of cardiovascular disease with chelator ethylenediamine tetraacetate (EDTA). Recent studies have indicated that such chelation treatment has only marginal impact on the course of vascular disease. In contrast, endogenous calcium chelation with removal of calcium from the cardiovascular system paralleled by improved bone mineralization exerted, i.e., by matrix Gla protein (MGP) and osteocalcin, appears to significantly delay the development of cardiovascular diseases. After post-translational vitamin-K-dependent carboxylation of glutamic acid residues, MGP and other vitamin-K-dependent proteins (VKDPs) can chelate calcium through vicinal carboxyl groups. Dietary vitamin K is mainly provided in the form of phylloquinone from green leafy vegetables and as menaquinones from fermented foods. Here, we provide a review of clinical studies, addressing the role of vitamin K in cardiovascular diseases, and an overview of vitamin K kinetics and biological actions, including vitamin-K-dependent carboxylation and calcium chelation, as compared with the action of the exogenous (therapeutic) chelator EDTA. Consumption of vitamin-K-rich foods and/or use of vitamin K supplements appear to be a better preventive strategy than EDTA chelation for maintaining vascular health.

  • 69.
    Aasheim, Fanny
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Gestsson, Linnea
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Det spelar ingen roll hur du gör det - bara du gör det: Hur ett koncept kan utformas för att uppmana till motion utan att bidra till hälsohets2020Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
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  • 70.
    Aasland, Olaf G.
    et al.
    University of Oslo, Norway.
    Nygaard, Peter
    Norwegian Institute for Alcohol and Drug Research, Oslo, Norway.
    Nilsen, Per
    Linköpings universitet, Institutionen för medicin och hälsa, Socialmedicin och folkhälsovetenskap. Linköpings universitet, Hälsouniversitetet.
    The long and winding road to widespread implementation of screening and brief intervention for alcohol problems: A historical overview with special attention to the WHO initiatives2008Ingår i: Nordic Studies on Alcohol and Drugs, ISSN 1455-0725, E-ISSN 1458-6126, Vol. 25, nr 6, s. 469-476Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Before 1970, special institutions, often prison-like, were built for the severely dependent. The effect of this type of treatment, often lasting for months or even years, was hard to document scientifically. During the 1970s several steps were taken towards a more preventive strategy that involved delivery of alcohol interventions in general health care settings, particularly within primary health care. The World Health Organization's (WHO) introduction of the concepts of hazardous and harmful drinking represented a shift from the traditional dichotomous view of individuals being alcoholic-or-not to a continuum where, in line with Rose's "prevention paradox", a large number of people with low risk may give rise to more cases of disease than the small number with high risk. The need for efficient methods to detect persons with various degrees of alcohol risk was evident, and a WHO multinational project that resulted in the publication of AUDIT (Alcohol Use Disorders identification Test) was carried out in the mid 1980s. The usefulness of this principle of case finding was then investigated in a subsequent multinational WHO project of brief intervention, as well as in several other similar projects. Many of these projects have proven quite efficient, but screening and brief intervention for alcohol problems is still not standard procedure in primary health care. The paper discusses some of the reasons why.

  • 71.
    Aaslund, Ulrika
    et al.
    Linköpings universitet, Ekonomiska institutionen.
    Larsson Jagbrant, Anna
    Linköpings universitet, Ekonomiska institutionen.
    Nutida uppfattningar om svensk utrikespolitik: en diskursanalays av svenska politikers föreställningar om utrikespolitik idag2005Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [sv]

    Syftet med vår uppsats är att undersöka diskursen om utrikespolitik ur ett svenskt perspektiv. I uppsatsen undersöker vi hur svenska politiker diskuterar dagens och framtidens svenska utrikespolitik. Studien bygger på intervjuer med sju av ledamöterna i riksdagens utrikesutskott. I analysen av dessa ledamöters utsagor utgår vi från ett diskursanalytiskt perspektiv och använder diskursteorin som verktyg. Svensk utrikespolitik har i historien ofta förknippats med neutralitetstänkande och främjandet av värderingar såsom mänskliga rättigheter och nedrustning. I och med utvecklingen av en gemensam utrikes- och säkerhetspolitik för Europa pågår dock en diskussion om vad svensk utrikespolitik är idag. Likaså pågår idag en akademisk debatt om hur utrikespolitik ska förstås i en alltmer internationaliserad värld. Till följd av detta är vår studie av svenska politikers föreställningar om utrikespolitik i allra högsta grad befogad.

    Vi konstaterar i vår studie att både enighet och meningsskiljaktigheter förekommer i den diskurs om utrikespolitik som de intervjuade ledamöterna ger uttryck för. Under våra intervjuer framkom framförallt att utrikespolitik definieras som relationer mellan stater och staters rätt att bedriva utrikespolitik motiverades med hänvisning till att medborgarna i en stat har en gemensam identitet. Det blev också tydligt att grupptillhörighet ofta uppfattades påverka det europeiska utrikespolitiska samarbetet. Sammanfattningsvis kan vi alltså konstatera att ett djupt rotat identitetstänkande tycks vara tongivande för synen på utrikespolitik.

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  • 72.
    Aasmundtveit, K.E.
    et al.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Samuelsen, E.J.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Guldstein, M.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Steinsland, C.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Flornes, O.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Fagermo, C.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Seeberg, T.M.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Pettersson, Lars
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Feidenhans'l, R.
    Forskningscenter Risø, DK-4000 Roskilde, Denmark.
    Ferrer, S.
    Europ. Synchrt. Radiation Facility, BP 220, F-38043 Grenoble Cedex, France.
    Structural anisotropy of poly(alkylthiophene) films2000Ingår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 33, nr 8, s. 3120-3127Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The structural anisotropy of various poly(alkylthiophene) films have been studied by X-ray diffraction, using both conventional methods and synchrotron radiation at grazing incidence. Solution-cast films orient with the side chains preferably normal to the film surface, whereas spin-cast films of nonstereoregular material orient with both the main and the side chains in the film plane. For thick (10-50 µm) solution-cast films, the degree of orientation depends strongly on the solvent used for casting, and on the stereoregularity of the polymer, films of stereoregular materials being more oriented than those of nonregular materials. The most oriented nonregular films are those cast from mixtures of chloroform and tetrahydrofuran. Thin (50-500 nm) solution-cast films are more oriented than the thicker ones, and the effects of different stereoregularity or different casting solvents are small. For spin-cast films, the degree of orientation is independent of substrate and solvent. Spin-cast films of stereoregular material have two different phases: One with the side chains normal to the substrate, and another where they are parallel to the substrate. The diffraction peaks of spin-cast poly(octylthiophene) narrow considerably upon heating.

  • 73.
    Aasmundtveit, K.E.
    et al.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., Trondheim, Norway.
    Samuelsen, E.J.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., Trondheim, Norway.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Pettersson, Lars
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Johansson, Tomas
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Ferrer, S.
    Europ. Synchrt. Radiat. Facil. (E., F-38043, Grenoble, France.
    Structural aspects of electrochemical doping and dedoping of poly(3,4-ethylenedioxythiophene)2000Ingår i: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 113, nr 1, s. 93-97Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electrochemical dedoping and redoping of p-toluene sulfonate doped poly(3,4-ethylenedioxythiophene) (PEDOT) has been studied with in situ grazing incidence diffraction with water used as an electrolyte. The diffraction peak positions and integrated intensities do not change significantly during doping and dedoping, while the peak widths increase upon dedoping and decrease upon doping. This implies that the lattice parameters and the relative positions of the polymer chains and the p-toluene sulfonate ions remain unchanged, the redox processes being carried out by the motion of smaller ions between the polymer and the electrolyte, and that the structural order decreases upon dedoping and increases upon doping in a reversible manner.

  • 74.
    Aasmundtveit, K.E.
    et al.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskaplige U., N-7491 Trondheim, Norway.
    Samuelsen, E.J.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskaplige U., N-7491 Trondheim, Norway.
    Mammo, W.
    Institutionen för Organisk Kemi, Chalmers Tekniska Hôgskola, S-412 96 Göteborg, Sweden.
    Svensson, M.
    Institutionen för Organisk Kemi, Chalmers Tekniska Hôgskola, S-412 96 Göteborg, Sweden.
    Andersson, M.R.
    Institutionen för Polymerteknik, Chalmers Tekniska Hôgskola, S-412 96 Göteborg, Sweden.
    Pettersson, Lars
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Structural ordering in phenyl-substituted polythiophenes2000Ingår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 33, nr 15, s. 5481-5489Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Various substituted poly(phenylthiophene)s have been studied by X-ray diffraction. They are semicrystalline, with very different degrees of crystallinity. Those with para-substituted phenyl groups have a low degree of crystallinity, whereas those with ortho-substituted phenyl groups are more crystalline. The most crystalline materials in this study have two equally long substituents on the phenyl ring, one at the ortho position and the other at the ortho or meta position on the opposite side of the phenyl ring. Poly(3-(2,5-dioctylphenyl)thiophene) (PDOPT) was most thoroughly studied, and a structural model is proposed. The structure of PDOPT is quite different from previously studied substituted polythiophenes in that the octyl side chains are directed normal to the thiophene planes. In this way, the conjugated polymer chains are kept separated from each other. Solution-cast and spin-cast PDOPT films are anisotropic, with the octyl side chains oriented normal to the film surface in both cases. This is contrary to the situation for poly(3-alkylthiophene)s, where solution-cast and spin-cast films orient in different ways.

  • 75.
    Aav, Sebastian
    Linköpings universitet, Institutionen för teknik och naturvetenskap.
    Adaptive Music System for DirectSound2005Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    With the intention of surveying the field of research in adaptive audio systems for interactive media, a suggested audio system design for adaptive music control is described, and a prototype implementation of key parts of the system is presented and evaluated.

    Foregoing midi-triggered sound banks, the proposed design uses layered segmented audio files, defined and controlled by XML-scripts. The results demonstrate an inclination of a flexible system, capable of adequate adaptive behaviour of high quality sound.

    The implemented system will serve as an extensive basis for future work contributing to the research of adaptive behaviour to both music and sound effects for interactive media, and also as a preliminary foray into the more experimental field of stand-alone non-linear music playback.

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  • 76. Aavikko, R.
    et al.
    Saarinen, K.
    Magnusson, Björn
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial.
    Janzén, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial.
    Clustering of Vacancies in Semi-Insulating SiC Observed with Positron Spectroscopy2006Ingår i: Materials Science Forum, Vols. 527-529, 2006, Vol. 527-529, s. 575-578Konferensbidrag (Refereegranskat)
  • 77. Aavikko, R
    et al.
    Saarinen, K
    Magnusson, Björn
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial.
    Janzén, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial.
    Observation of vacancy clusters in HTCVD grown SiC2005Ingår i: Materials Science Forum, Vols. 483-485, 2005, Vol. 483, s. 469-472Konferensbidrag (Refereegranskat)
    Abstract [en]

    Positron lifetime spectroscopy was used to study defects in semi-insulating (SI) silicon carbide (SiC) substrates grown by high-temperature chemical vapor deposition (HTCVD). The measured positron lifetime spectra can be decomposed into two components, of which the longer corresponds to vacancy clusters. We have carried out atomic superposition calculations to estimate the size of these clusters.

  • 78. Aavikko, R.
    et al.
    Saarinen, K.
    Tuomisto, F.
    Magnusson, Björn
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska högskolan.
    Nguyen, Son Tien
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska högskolan.
    Janzén, Erik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska högskolan.
    Clustering of vacancy defects in high-purity semi-insulating SiC2007Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 75, nr 8, s. 085208-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Positron lifetime spectroscopy was used to study native vacancy defects in semi-insulating silicon carbide. The material is shown to contain (i) vacancy clusters consisting of four to five missing atoms and (ii) Si-vacancy-related negatively charged defects. The total open volume bound to the clusters anticorrelates with the electrical resistivity in both as-grown and annealed materials. Our results suggest that Si-vacancy-related complexes electrically compensate the as-grown material, but migrate to increase the size of the clusters during annealing, leading to loss of resistivity. © 2007 The American Physical Society.

  • 79.
    Abadei, S.
    et al.
    Department of Microelectronics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
    Gevorgian, S.
    Department of Microelectronics, Chalmers University of Technology, 412 96 Göteborg, Sweden, Core Unit Research Center, Ericsson Microwave Systems, SE-431 84, Mölnda, Sweden.
    Kugler, Veronika Mozhdeh
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Helmersson, Ulf
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Plasma och beläggningsfysik.
    Andreasson, J.
    Department of Materials and Manufacturing Engineering, Luleå University of Technology, 971 87, Luleå, Sweden.
    Microwave properties of tunable capacitors basee on magnetron sputtered ferroelectric Na0.5K0.5NbO3 film on low and high resistivity silicon substrates2001Ingår i: Integrated Ferroelectrics, ISSN 1058-4587, E-ISSN 1607-8489, Vol. 39, nr 1-4, s. 359-366Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In this work, small signal DC voltage dependent dielectric permittivity, loss tangent, and tuneability of magnetron sputtered epitaxial Na0.5K0.5NO3 films are studied experimentally. (100)-oriented Na0.5K0.5NbO3 films are deposited onto SiO2-buffered CMOS grade low resistivity (p = 10-20 cm) and high resistivity (p = 15-45 kcm) silicon substrates. Planar capacitors with 2 or 4 m gaps between electrodes have been fabricated on top of ferroelectric films. These devices have been characterized in the frequency range 1.0 MHz to 50 GHz at temperatures 30 - 300K. Na0.5K0.5NbO3/SiO2/Si structures on high resistivity silicon substrate exhibit C-V performances typical for Metal-Insulator- Semiconductor (MIS) capacitors. At low frequencies, f 1.0 GHz, the large tuneability and large losses are associated with the MIS structure, while at higher microwave frequencies the tuneability is mainly associated with the ferroelectric, film. At 1.0 MHz and room temperature, the tuneability of Na0.5K0.5NbO3/SiO2/Si structures more than 90%, reducing to 10-15 % at 50 GHz. The losses decrease with increasing the DC bias and frequency. A Q-factor more than 15 at 50 GHz is observed. The dielectric permittivity of the Na0.5K0.5NbO3 film is in the range 50-150 at frequencies 0.045-50 GHz. On low resistivity substrate the performance of Na0.5K0.5NbO3 films is completely screened by the high losses in silicon, and the tuneability is negligible. © 2001 Taylor and Francis.

  • 80.
    Abadias, Gregory
    et al.
    University of Poitiers, France.
    Sarakinos, Kostas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Plasma och beläggningsfysik. Linköpings universitet, Tekniska högskolan.
    Fenker, Martin
    FEM, Germany.
    Kassavetis, Spiros
    Aristotle University of Thessaloniki, Greece.
    Editorial Material: Preface in SURFACE and COATINGS TECHNOLOGY, vol 255, issue , pp2014Ingår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    n/a

  • 81.
    Abadias, Gregory
    et al.
    Univ Poitiers, France.
    Sarakinos, Kostas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanodesign. Linköpings universitet, Tekniska fakulteten.
    Patsalas, Panos
    Aristotle Univ Thessaloniki, Greece.
    Preface2020Ingår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 404, artikel-id 126450Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    n/a

  • 82.
    Abadir Guirgis, Georg
    Linköpings universitet, Institutionen för datavetenskap.
    Lärarperspektiv på riskutbildningen för motorcyklister2011Självständigt arbete på grundnivå (kandidatexamen), 12 poäng / 18 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Under det senaste decenniet har det i Sverige blivit allt populärare att åka motorcykel. Enobligatorisk riskutbildning för behörighet A och A1 infördes från och med den 1 november2009. Då riskutbildningen är ny har få utvärderingar gjorts.Denna studie utvärderar riskutbildningen för motorcyklister utifrån trafikskolläraresperspektiv. Målet har varit att sammanställa synpunkter och erfarenheter från lärarna påutbildningen. Ett ytterligare mål har varit att undersöka trafikskollärarnas upplevda effekter avutbildningen på elevers trafikbeteende. Sex semistrukturerade intervjuer med trafikskolläraresamt en observationsstudie på olika trafikskolor genomfördes. Utöver detta genomfördesdeltagande observation av en fortbildning där 15 trafikskollärare deltog. Resultatet frånstudien visar att lärarna anser att behovet av riskutbildningen är stort och attimplementationen av den nya riskutbildningen gått bra. Förutom att elever efter utbildningenrefererar till den, vilket enligt lärarna indikerar att de tagit till sig vad som sagts, märks det nui större utsträckning än tidigare att elever kör lugnare och tänker sig mer för i vissasituationer. Detta påtalades vara ett klart önskvärt resultat.

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  • 83.
    Abadir Guirgis, Georg
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Filosofiska fakulteten.
    Mindre energi och rätt tid: Utvärdering av utbildning och träning för lokförare i energieffektiv körning – en simulatorstudie2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Under 1980-talet introducerades den första tågsimulatorn i svensk lokförarutbildning. Denna simulator är fortfarande den enda fullskalesimulator som används för att utbilda lokförare i Sverige. En anledning till att det inte finns fler tycks vara att det bl.a. saknas pedagogiska och ekonomiska motiv för en utvidgad användning av simulatorer i undervisning och träning. Energibesparingar inom spårtrafik dvs. att köra tåg energieffektivt är idag mycket aktuellt hos alla tågoperatörer i Sverige. Vissa operatörer utbildar redan sina förare teoretiskt i energieffektiv körning och tester av energieffektiv körning i verklig trafik har visat på en möjlig besparing om 16 % energi efter det att lokförare genomgått en teoretisk utbildning i energieffektiv körning. Då det emellertid fanns en del osäkerhet i mätdata från de tester som genomförts i verklig trafik och betingelserna samt försöksprocedur varierade mellan förarna fanns det ett behov av att undersöka besparingspotentialen under mer kontrollerade former. Dessutom visade sig att utbildning samt tillgång till ett stödsystem under körning gav en mindre besparing i energi (13 %). Således genomfördes en studie med hjälp av en tågsimulator. I simulatorn har man full kontroll på mätdata och betingelserna är lika för alla förare. Simulatorn som användes i studien är utvecklad på VTI (Statens väg- och transportforskningsinstitut) och är modellerad efter en X50 Regina. Syftet med denna studie var således att undersöka om samma teoretiska utbildning i energieffektiv körning, i kombination med simulatorträning under ideala förhållanden skulle ge lika bra eller bättre energibesparing jämfört med resultaten från tester i verklig trafik. Vidare undersöktes effekten av återkoppling under träningen med avseende på energibesparing. I studien deltog 24 lokförarelever som delades in i tre grupper med 8 elever i varje. Två av grupperna fick genomföra två körningar (referens- och testkörning) med utbildning och simulatorträning mellan tillfällena, medan den tredje gruppen (kontrollgrupp) endast genomförde referens- och testkörning utan utbildning och träning. De två grupperna som fick utbildning fick dock träna under två olika betingelser, en med återkoppling (energiförbrukning och banlutning) och en utan återkoppling. Det visade sig att utbildning i energieffektiv körning i kombination med 30 minuters simulatorträning resulterade i en total besparing för båda grupperna på ungefär 24 % energi, om man sen tar hänsyn till att man förbättrar sin körning genom att bara få tillfälle att köra upprepade gånger (kontrollgruppen använde 8 % mindre energi andra gången) så visade det sig att besparingen blev lika stor som den man fann i verklig trafik (16 %). Då resultaten blev lika fast betingelserna var olika finns det anledning till att vidare undersöka hur olika körförhållanden påverkar utfallet. Dessutom behöver man bättre förstå varför utbildning plus stödsystem gav mindre effekt än bara utbildning i verklig trafik samt varför återkoppling under träning inte gav någon påvisbar effekt. Det vill säga det finns anledning till ytterligare insatser för att utforma träning och stödsystem till förarna. Förutom energibesparing visade resultatet att rättidigheten förbättrades efter utbildning och simulatorträning. Resultaten talar för att det finns outnyttjad potential för tågsimulatorer i den svenska lokförarutbildningen både för att träna och utvärdera effekter av utbildningsinsatser.

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  • 84.
    Abadpour, Shadab
    et al.
    Oslo Univ Hosp, Norway; Univ Oslo, Norway.
    Tyrberg, Bjorn
    AstraZeneca, Sweden.
    Schive, Simen W.
    Oslo Univ Hosp, Norway.
    Wennberg Huldt, Charlotte
    AstraZeneca, Sweden.
    Gennemark, Peter
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten. AstraZeneca, Sweden.
    Ryberg, Erik
    AstraZeneca, Sweden.
    Ryden-Bergsten, Tina
    AstraZeneca, Sweden.
    Smith, David M.
    AstraZeneca, Sweden; AstraZeneca, England.
    Korsgren, Olle
    Uppsala Univ, Sweden.
    Skrtic, Stanko
    AstraZeneca, Sweden; Univ Gothenburg, Sweden.
    Scholz, Hanne
    Oslo Univ Hosp, Norway; Univ Oslo, Norway.
    Winzell, Maria Sorhede
    AstraZeneca, Sweden.
    Inhibition of the prostaglandin D-2-GPR44/DP2 axis improves human islet survival and function2020Ingår i: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 63, nr 7, s. 1355-1367Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aims/hypothesis Inflammatory signals and increased prostaglandin synthesis play a role during the development of diabetes. The prostaglandin D-2 (PGD(2)) receptor, GPR44/DP2, is highly expressed in human islets and activation of the pathway results in impaired insulin secretion. The role of GPR44 activation on islet function and survival rate during chronic hyperglycaemic conditions is not known. In this study, we investigate GPR44 inhibition by using a selective GPR44 antagonist (AZ8154) in human islets both in vitro and in vivo in diabetic mice transplanted with human islets. Methods Human islets were exposed to PGD(2) or proinflammatory cytokines in vitro to investigate the effect of GPR44 inhibition on islet survival rate. In addition, the molecular mechanisms of GPR44 inhibition were investigated in human islets exposed to high concentrations of glucose (HG) and to IL-1 beta. For the in vivo part of the study, human islets were transplanted under the kidney capsule of immunodeficient diabetic mice and treated with 6, 60 or 100 mg/kg per day of a GPR44 antagonist starting from the transplantation day until day 4 (short-term study) or day 17 (long-term study) post transplantation. IVGTT was performed on mice at day 10 and day 15 post transplantation. After termination of the study, metabolic variables, circulating human proinflammatory cytokines, and hepatocyte growth factor (HGF) were analysed in the grafted human islets. Results PGD(2) or proinflammatory cytokines induced apoptosis in human islets whereas GPR44 inhibition reversed this effect. GPR44 inhibition antagonised the reduction in glucose-stimulated insulin secretion induced by HG and IL-1 beta in human islets. This was accompanied by activation of the Akt-glycogen synthase kinase 3 beta signalling pathway together with phosphorylation and inactivation of forkhead box O-1and upregulation of pancreatic and duodenal homeobox-1 and HGF. Administration of the GPR44 antagonist for up to 17 days to diabetic mice transplanted with a marginal number of human islets resulted in reduced fasting blood glucose and lower glucose excursions during IVGTT. Improved glucose regulation was supported by increased human C-peptide levels compared with the vehicle group at day 4 and throughout the treatment period. GPR44 inhibition reduced plasma levels of TNF-alpha and growth-regulated oncogene-alpha/chemokine (C-X-C motif) ligand 1 and increased the levels of HGF in human islets. Conclusions/interpretation Inhibition of GPR44 in human islets has the potential to improve islet function and survival rate under inflammatory and hyperglycaemic stress. This may have implications for better survival rate of islets following transplantation.

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  • 85.
    Abafogi, Abdurhaman Teyib
    et al.
    Sungkyunkwan Univ, South Korea.
    Kim, Jaewon
    Sungkyunkwan Univ, South Korea.
    Lee, Jinyeop
    Sungkyunkwan Univ, South Korea.
    Mohammed, Merem Omer
    Sungkyunkwan Univ, South Korea.
    van Noort, Danny
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teknisk biologi. Linköpings universitet, Tekniska fakulteten. Univ Ljubljana, Slovenia; Univ Ingn and Tecnol UTEC, Peru.
    Park, Sungsu
    Sungkyunkwan Univ, South Korea; Sungkyunkwan Univ, South Korea; Sungkyunkwan Univ, South Korea.
    3D-Printed Modular Microfluidic Device Enabling Preconcentrating Bacteria and Purifying Bacterial DNA in Blood for Improving the Sensitivity of Molecular Diagnostics2020Ingår i: Sensors, E-ISSN 1424-8220, SENSORS, Vol. 20, nr 4, artikel-id 1202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Molecular diagnostics for sepsis is still a challenge due to the presence of compounds that interfere with gene amplification and bacteria at concentrations lower than the limit of detection (LOD). Here, we report on the development of a 3D printed modular microfluidic device (3Dpm mu FD) that preconcentrates bacteria of interest in whole blood and purifies their genomic DNA (gDNA). It is composed of a W-shaped microchannel and a conical microchamber. Bacteria of interest are magnetically captured from blood in the device with antibody conjugated magnetic nanoparticles (Ab-MNPs) at 5 mL/min in the W-shaped microchannel, while purified gDNA of the preconcentrated bacteria is obtained with magnetic silica beads (MSBs) at 2 mL/min in the conical microchamber. The conical microchamber was designed to be connected to the microchannel after the capturing process using a 3D-printed rotary valve to minimize the exposure of the MSBs to interfering compounds in blood. The pretreatment process of spiked blood (2.5 mL) can be effectively completed within about 50 min. With the 3Dpm mu FD, the LOD for the target microorganism Escherichia coli O157:H7 measured by both polymerase chain reaction (PCR) with electrophoresis and quantitative PCR was 10 colony forming unit (CFU) per mL of whole blood. The results suggest that our method lowers the LOD of molecular diagnostics for pathogens in blood by providing bacterial gDNA at high purity and concentration.

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  • 86.
    Aban, Kevin
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    Göst, Jens
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska högskolan.
    Analysis of transports with pharmaceuticals on Arlanda airport2013Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Rapporten syftar till att kartlägga och analysera dagens transportflöde av läkemedel på fraktområdet Cargo City på Arlanda. Cargo Center och APH Logistics är två fraktagenter som har sin verksamhet på Cargo City. Observera att Cargo City och Cargo Center inte har samma innebörd. Cargo Center och APH Logistics erbjuder genom nära samarbete transport och hantering av temperaturkänsligt gods, som till exempel läkemedel. Läkemedel är värdefullt gods som kräver särskild skötsel vid transport, hantering och förvaring. Det ställer stränga krav på samtliga aktörer i försörjningskedjan. Genom studiebesök och intervjuer har författarna kartlagt det befintliga flödet av läkemedel. SACT, ett åkeri och dotterbolag till Cargo Center, utför transporten av godset till Cargo City med nerkylda lastbilar. APH Logistics omlastningsterminal på Cargo City är temperaturkontrollerad, vilket innebär att läkemedelsgodset förvaras och lastats i flygcontainrar där. Det färdiglastade godset forslas sedan vidare till Cargo Centers terminal. Där sker vikt- och volymkontroll av godset, det registreras i olika datasystem och slutligen märks det med etiketter, så som flygfraktsedeln. Mycket av godset som hanteras på Arlanda körs med lastbil till andra flygplatser och destinationer runt om i Europa istället för att flygfraktas direkt från flygplatsen. Dessutom hanteras och förvaras inte allt läkemedelsgods under temperaturkontrollerade former. En totalkostnadsanalys har gjorts för att jämföra olika transportflödesscenarion. Dessutom har författarna identifierat den kundservice Cargo Center och APH Logistics bör erbjuda kunden. Den bygger på kvalitativa resonemang. Resultatet av rapporten är författarnas rekommendation till företagen av hur de bör gå tillväga i framtiden. Den ger både kortsiktiga och långsiktiga tips.

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  • 87.
    Abara, Precious Ugo
    et al.
    Univ Padua, Italy; Tech Univ Munich, Germany.
    Ticozzi, Francesco
    Univ Padua, Italy; Dartmouth Coll, NH 03755 USA.
    Altafini, Claudio
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska fakulteten.
    Spectral Conditions for Stability and Stabilization of Positive Equilibria for a Class of Nonlinear Cooperative Systems2018Ingår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 63, nr 2, s. 402-417Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nonlinear cooperative systems associated to vector fields that are concave or subhomogeneous describe well interconnected dynamics that are of key interest for communication, biological, economical, and neural network applications. For this class of positive systems, we provide conditions that guarantee existence, uniqueness and stability of strictly positive equilibria. These conditions can be formulated directly in terms of the spectral radius of the Jacobian of the system. If control inputs are available, then it is shown how to use state feedback to stabilize an equilibrium point in the interior of the positive orthant.

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  • 88.
    Abarghouyi, Hadis
    et al.
    IUST, Iran; MTNi Co, Iran.
    Razavizadeh, S. Mohammad
    IUST, Iran.
    Björnson, Emil
    Linköpings universitet, Institutionen för systemteknik, Kommunikationssystem. Linköpings universitet, Tekniska fakulteten.
    QoE-Aware Beamforming Design for Massive MIMO Heterogeneous Networks2018Ingår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, nr 9, s. 8315-8323Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the main goals of the future wireless networks is improving the users quality of experience (QoE). In this paper, we consider the problem of the QoE-based resource allocation in the downlink of a massive multiple-input multiple-output heterogeneous network. The network consists of a macrocell with a number of small cells embedded in it. The small cells base stations (BSs) are equipped with a few antennas, while the macro BS is equipped with a massive number of antennas. We consider the two services Video and Web Browsing and design the beamforming vectors at the BSs. The objective is to maximize the aggregated mean opinion score (MOS) of the users under constraints on the BSs powers and the required quality of service of the users. We also consider extra constraints on the QoE of users to more strongly enforce the QoE in the beamforming design. To reduce the complexity of the optimization problem, we suggest suboptimal and computationally efficient solutions. Our results illustrate that increasing the number of antennas at the BSs and also increasing the number of small cells antennas in the network leads to a higher user satisfaction.

  • 89.
    Abarkan, Myriam
    et al.
    Univ Bordeaux, France.
    Pirog, Antoine
    Univ Bordeaux, France.
    Mafilaza, Donnie
    Univ Bordeaux, France.
    Pathak, Gaurav
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. MOC, France.
    NKaoua, Gilles
    Univ Bordeaux, France.
    Puginier, Emilie
    Univ Bordeaux, France.
    OConnor, Rodney
    MOC, France.
    Raoux, Matthieu
    Univ Bordeaux, France.
    Donahue, Mary
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. MOC, France.
    Renaud, Sylvie
    Univ Bordeaux, France.
    Lang, Jochen
    Univ Bordeaux, France.
    Vertical Organic Electrochemical Transistors and Electronics for Low Amplitude Micro-Organ Signals2022Ingår i: Advanced Science, E-ISSN 2198-3844, Vol. 9, nr 8, artikel-id 2105211Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electrical signals are fundamental to key biological events such as brain activity, heartbeat, or vital hormone secretion. Their capture and analysis provide insight into cell or organ physiology and a number of bioelectronic medical devices aim to improve signal acquisition. Organic electrochemical transistors (OECT) have proven their capacity to capture neuronal and cardiac signals with high fidelity and amplification. Vertical PEDOT:PSS-based OECTs (vOECTs) further enhance signal amplification and device density but have not been characterized in biological applications. An electronic board with individually tuneable transistor biases overcomes fabrication induced heterogeneity in device metrics and allows quantitative biological experiments. Careful exploration of vOECT electric parameters defines voltage biases compatible with reliable transistor function in biological experiments and provides useful maximal transconductance values without influencing cellular signal generation or propagation. This permits successful application in monitoring micro-organs of prime importance in diabetes, the endocrine pancreatic islets, which are known for their far smaller signal amplitudes as compared to neurons or heart cells. Moreover, vOECTs capture their single-cell action potentials and multicellular slow potentials reflecting micro-organ organizations as well as their modulation by the physiological stimulator glucose. This opens the possibility to use OECTs in new biomedical fields well beyond their classical applications.

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  • 90.
    Abate, E.
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. University of Gondar, Ethiopia.
    Elias, D.
    University of Southern Denmark, Denmark.
    Getachew, A.
    University of Gondar, Ethiopia.
    Alemu, S.
    University of Gondar, Ethiopia.
    Diro, E.
    University of Gondar, Ethiopia.
    Britton, S.
    Karolinska Hospital, Sweden.
    Aseffa, A.
    Armauer Hansen Research Institute, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Kalmar County Hospital, Sweden.
    Effects of albendazole on the clinical outcome and immunological responses in helminth co-infected tuberculosis patients: a double blind randomised clinical trial2015Ingår i: International Journal of Parasitology, ISSN 0020-7519, E-ISSN 1879-0135, Vol. 45, nr 2-3, s. 133-140Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite several review papers and experimental studies concerning the impact of chronic helminth infection on tuberculosis in recent years, there is a scarcity of data from clinical field studies in highly endemic areas for these diseases. We believe this is the first randomised clinical trial investigating the impact of albendazole treatment on the clinical and immunological outcomes of helminth co-infected tuberculosis patients. A randomised, double-blind, placebo-controlled trial of albendazole (400 mg per day for 3 days) in helminth-positive tuberculosis patients was conducted in Gondar, Ethiopia. The primary outcome was clinical improvement (Delta TB score) after 2 months. Among secondary outcomes were changes in the levels of eosinophils, CD4+ T cells, regulatory T cells, IFN-gamma, IL-5 and IL-10 after 3 months. A total of 140 helminth co-infected tuberculosis patients were included with an HIV co-infection rate of 22.8%. There was no significant effect on the primary outcome (Delta TB score: 5.6 +/- 2.9 for albendazole versus 5.9 +/- 2.5 for placebo, P = 0.59). The albendazole-treated group showed a decline in eosinophil cells (P = 0.001) and IL-10 (P = 0.017) after 3 months. In an exploratory analysis after 12 weeks, the albendazole treated group showed a trend towards weight gain compared with the placebo group (11.2 +/- 8.5 kg versus 8.2 +/- 8.7 kg, P = 0.08)). The reductions in eosinophil counts and IL-10 show that asymptomatic helminth infection significantly affects host immunity during tuberculosis and can be effectively reversed by albendazole treatment. The clinical effects of helminth infection on chronic infectious diseases such as tuberculosis merit further characterisation. (C) 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  • 91. Beställ onlineKöp publikationen >>
    Abate, Ebba
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    The impact of helminth infection in patients with active tuberculosis2013Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The geographic distribution of helminth infection and tuberculosis (TB) overlap substantially. Experimental animal models and limited data from humans have shown that intestinal helminths could subvert the host immune response towards a T-helper 2 (Th2)-type immune response and an increased regulatory T-cell activity (Tregs). This in turn affects the host's ability to mount an effective Th1 immune-mediated protection against Mycobacterium tuberculosis. However, evidence for this hypothesis in the human setting from helminth infected TB patients is limited. This thesis primarily focuses on the immunological and clinical impact of helminth infection on pulmonary TB. The kinetics of the Quantiferon-Gold (QFN) assay, which measures IFN-³ response to TB-specific antigens in whole blood was assessed and showed a modest decline during TB treatment to the level observed for healthy blood donors. We further assessed another clinical monitoring tool, the-TB-score, composed of clinical signs and symptoms of TB, and found an early decline two weeks after initiation of TB- treatment where a failure of decline correlated with increased mortality. Overall, the helminth co-infection rate was significantly higher in TB patients compared to healthy controls. Helminth co-infection was associated to a significantly higher rate of eosinophilia and IgE-levels in healthy controls and patients with tuberculosis. During the first weeks of anti-TB treatment, a marked decrease in the rate of helminth infection was observed in HIV co-infected compared to HIV-negative TB patients. However, helminth co-infection was more common in HIV negative than HIV positive TB patients. There was no detectable impact of helminth infection on the clinical presentation of pulmonary tuberculosis. At baseline, helminth co-infected TB patients showed an increased frequency of Tregs compared to helminth negative TB patients and healthy controls. This was accompanied by an increased rate of PPD stimulated IL-5 and spontaneous production of IL-10 by peripheral blood mononuclear cells among helminth co-infected TB patients. A placebo controlled randomized trial was conducted in order to test the hypothesis that albendazole treatment of helminth positive TB patients may improve the clinical response of TB by reducing the immunmodulatory effect of helminthes on TB immunity. A total of 140 helminth co-infected TB patients were randomized to albendazole (400 mg per os for three consecutive days) or placebo. No significant difference was observed between the albendazole and placebo group in terms of the primary outcome (TB score change between baseline and week 8). Among the secondary outcomes, a significant decline of peripheral eosinophil cells was observed in the albendazole treated group, but no effect on other outcome variables (changes in chest x-ray findings, IgE level and sputum smear conversion). Regarding the immunological assessment no significant difference was observed for changes in Tregs, and PPD-induced production of IFN- ³ or IL-5 although a non-significant trend of a decrease in IL-10 expressing PBMCs were observed in the albendazole group. Taken together, the burden of helminth infection was higher in TB patients than in a healthy control group. Helminth co-infection during pulmonary TB in the human setting induces an immune response characterized by increased IgE production, eosinophilia as well as increased levels of Tregs and spontaneous IL-10 production. Thus, the immunological impact of helminth infection on the outcome and risk for developing TB merits further investigation.

    Delarbeten
    1. Kinetics of the QuantiFERON((R))-TB Gold In-Tube test during treatment of patients with sputum smear-positive tuberculosis in relation to initial TST result and severity of disease
    Öppna denna publikation i ny flik eller fönster >>Kinetics of the QuantiFERON((R))-TB Gold In-Tube test during treatment of patients with sputum smear-positive tuberculosis in relation to initial TST result and severity of disease
    Visa övriga...
    2010 (Engelska)Ingår i: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 42, nr 9, s. 650-657Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Abstract The QuantiFERON((R))-TB Gold In-Tube test (QFN) measures interferon-gamma production in response to Mycobacterium tuberculosis antigens. Our aim was to assess the kinetics of the QFN and initial tuberculin skin test (TST) result in relation to severity of disease in a tuberculosis (TB) endemic area. Smear-positive TB patients (n = 71) were recruited at Gondar University Hospital, Ethiopia. The TST, QFN, CD4+ cell count and clinical symptoms (TB score) were assessed and followed up during treatment. From baseline to 7 months after treatment, there was a significant decrease in QFN reactivity (93.8% to 62.5% in HIV-negative/TB; 70.3% to 33.3% in HIV-positive/TB patients) down to a level comparable to a control group of blood donors (51.2%). The agreement between TST and QFN was poor in TB patients compared to healthy controls. A negative TST correlated to more advanced TB in contrast to a negative QFN test. We conclude that the QFN reactivity is significantly reduced at the end of treatment against active TB to the background level of healthy blood donors, and that the agreement between TST and QFN is poor including correlation to the severity of disease.

    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-58804 (URN)10.3109/00365548.2010.482942 (DOI)000282716000002 ()20465490 (PubMedID)
    Tillgänglig från: 2010-08-27 Skapad: 2010-08-27 Senast uppdaterad: 2013-05-02
    2. Early treatment response evaluated by a clinical scoring system correlates with the prognosis of pulmonary tuberculosis patients in Ethiopia: A prospective follow-up study.
    Öppna denna publikation i ny flik eller fönster >>Early treatment response evaluated by a clinical scoring system correlates with the prognosis of pulmonary tuberculosis patients in Ethiopia: A prospective follow-up study.
    Visa övriga...
    2012 (Engelska)Ingår i: Scandinavian journal of infectious diseases, ISSN 1651-1980, Vol. 44, nr 11, s. 828-834Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Background: In resource-limited settings the monitoring of tuberculosis (TB) patients is challenging, and early identification of TB patients with a high mortality risk is important. The aim of this study was to investigate prospectively whether early changes in a clinical scoring system (TB score) can predict treatment outcome in Ethiopian patients with pulmonary tuberculosis. Method: TB patients (n = 250) and blood donors (n = 82) were recruited prospectively at Gondar University Hospital, Ethiopia. Clinical scoring was performed using an interview-based questionnaire and clinical examination. Results: Among TB patients (53.6% of whom were HIV co-infected) the median TB score declined from week 0 to week 2 (8 (interquartile range (IQR) 6-9) vs 4 (IQR 2-6)) and dropped to a low level at week 8, which was still significantly higher than that found in blood donors (2 (IQR 1-4) vs 0 (IQR 0-1), p < 0.0001). Patients who died had a significantly higher TB score at week 0, week 2, and week 8 than survivors. Mortality was associated with a failure to achieve a decrease greater than 25% in the TB score at 2 weeks. Baseline CD4 + cell counts (< 200 cells/mm(3)) were associated with mortality but not with initial TB score results. Conclusions: The TB score was increased during the first 2 months of treatment among patients who died. Failure to achieve a greater than 25% decrease in TB score after 2 weeks of treatment was associated with increased mortality. Repeated clinical scoring during the intensive phase of TB treatment could be useful to identify high-risk patients.

    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-85315 (URN)10.3109/00365548.2012.694468 (DOI)000310008900004 ()22812387 (PubMedID)
    Anmärkning

    funding agencies|Swedish Heart and Lung Foundation||EU/EDCTP project|JP 2009.10800.006|Swedish heart and lung Foundation (King Oscar II Jubilee Foundation)||EU/EDCP|JP.10800.006|

    Tillgänglig från: 2012-11-15 Skapad: 2012-11-15 Senast uppdaterad: 2013-05-02
    3. The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia
    Öppna denna publikation i ny flik eller fönster >>The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia
    Visa övriga...
    2012 (Engelska)Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 7, nr 8Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Background: Areas endemic of helminth infection, tuberculosis (TB) and HIV are to a large extent overlapping. The aim of this study was to assess the impact of asymptomatic helminth infection on the immunological response among TB patients with and without HIV, their house hold contacts and community controls. less thanbrgreater than less thanbrgreater thanMethodology: Consecutive smear positive TB patients (n = 112), their household contacts (n = 71) and community controls (n = 112) were recruited in Gondar town, Ethiopia. Stool microscopy, HIV serology, serum IgE level, eosinophil and CD4 counts were performed and tuberculosis patients were followed up for 3 months after initiation of anti-TB treatment. less thanbrgreater than less thanbrgreater thanResults: Helminth co-infection rate was 29% in TB patients and 21% in both community control and household contacts (p = 0.3) where Ascaris lumbricoides was the most prevalent parasite. In TB patients the seroprevalence of HIV was 47% (53/112). Eosinophilia and elevated IgE level were significantly associated with asymptomatic helminth infection. During TB treatment, the worm infection rate of HIV+/TB patients declined from 31% (10/32) at week 0 to 9% (3/32) at week 2 of TB treatment, whereas HIV2/TB patients showed no change from baseline to week 2, 29% (13/45) vs. 22.2% (10/45). This trend was stable at week 8 and 12 as well. less thanbrgreater than less thanbrgreater thanConclusion: One third of smear positive TB patients were infected with helminths. Eosinophilia and elevated IgE level correlated with asymptomatic worm infection, indicating an effect on host immunity. The rate of worm infection declined during TB treatment in HIV+/TB co-infected patients whereas no decline was seen in HIV2/TB group.

    Ort, förlag, år, upplaga, sidor
    Public Library of Science, 2012
    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-84349 (URN)10.1371/journal.pone.0042901 (DOI)000308206000014 ()
    Anmärkning

    Funding Agencies|Swedish Agency for Research Cooperation with Developing Countries||Swedish International Development Cooperation Agency (SAREC/SIDA)||European-Developing Countries Clinical Trials Partnership (EU/EDCTP)|JP 10800.006|Swedish Research Council||Swedish Heart and Lung Foundation (Oscar II Jubilee Foundation)||

    Tillgänglig från: 2012-10-05 Skapad: 2012-10-05 Senast uppdaterad: 2021-06-14
    4. Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis
    Öppna denna publikation i ny flik eller fönster >>Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis
    Visa övriga...
    2013 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: The effects of helminth infection on chronic infectious diseases such as HIV and tuberculosis (TB) merit further characterization. Thus, we assessed the baseline clinical characteristics of helminth infection in patients with active TB in a high endemic area.

    Methodology: Consecutive, newly diagnosed TB patients were recruited from three health institutions in the north Gondar administrative zone, Ethiopia. Structured questionnaires were used to collect socio-demographic and clinical characteristics. Additionally, the TB score, mid upper arm circumference, body mass index (BMI), BCG vaccination status, stool and sputum microscopy as well as HIV serology and CD4+T cells counts were evaluated.

    Results: A total of 377 pulmonary TB patients were included in the study. The helminth co infection rate was 33% (123/377) and the most prevalent parasite was Ascaris lumbricoides (53%, 65/123). The HIV co-infection rate was 29% (110/377). Seventy percent (77/110) of the HIV co-infected patients were on anti- retroviral therapy at the time of TB diagnosis. Helminth infection was more prevalent in HIV-negative TB patients compared to HIV-positive TB patients (p=0.025). Smoking and walking bare foot were independently associated to helminth infection in TB patients after adjusting for the influence of HIV. Other than increased eosinophilia, no other significant differences were observed between helminth positive and helminth negative TB patients in the clinical presentation including the TB score, CD4+T-cells, BMI or bacterial load.

    Conclusion: The clinical presentation of active pulmonary tuberculosis was not affected by helminth infection. Helminth infection was less frequent among HIV-positive TB patients and this finding merits further investigation.

    Nyckelord
    Tuberculosis, HIV, helminth, TB score, CD4, Ethiopia
    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-91825 (URN)
    Tillgänglig från: 2013-05-02 Skapad: 2013-05-02 Senast uppdaterad: 2013-05-02Bibliografiskt granskad
    5. Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial
    Öppna denna publikation i ny flik eller fönster >>Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial
    Visa övriga...
    2013 (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: The impact of helminth infection on the host immune response to tuberculosis (TB) has been characterized in experimental models but less so in the clinical setting. The objective of this study was to investigate the impact of deworming on the clinical outcome and cell mediated immune response in active TB.

    Methods: Newly diagnosed pulmonary TB patients in Gondar, Ethiopia were examined for helminth infection. Helminth-positive TB patients (W+/TB) were randomized to albendazole (400mg X III per os) or placebo. The primary outcome was change in TB-score after 2 months, and secondary outcomes were sputum smear conversion at the 2nd month, and changes in chest x-ray pattern, CD4+ T-cell count, eosinophil count, IgE-levels and immunological responses after 3 months. In a subset of W+/TB, W-/TB patients and healthy controls, flow cytometry and ELISPOT assays were used to characterize the regulatory T-cell population (Tregs) and the frequency of PPD- stimulated IFN-γ, IL-5 and IL-10 producing peripheral blood mononuclear cells (PBMCs).

    Results: A total of 140 helminth co-infected TB patients were included with an HIV coinfection rate of 22.8 %. Following albendazole treatment of the W+/TB patients, there was a significant decrease in helminth infection compared to placebo (8% (4/49) vs. 48 % (22/46), p<0.001). No significant effect was observed for albendazole compared to placebo on the primary outcome as evaluated by the TB-score (5.6 ±2.87 vs. 5.87 ±2.54, p=0.59). Eosinophil counts decreased significantly in the albendazole group. In a subgroup analysis of helminthnegative patients following albendazole treatment versus placebo, the albendazole group showed a trend for lower levels of IL-10 producing cells at month three (p=0.08). At baseline, W+/TB patients had a significantly higher mean level of Tregs (% Tregs/CD4+) compared to W-/TB patients and helminth-positive community controls. Additionally, the frequency of IFN-γ, IL-5 and spontaneous IL-10 levels was increased in helminth-positive compared to helminth-negative TB patients.

    Conclusions: No significant effects on the clinical outcome as measured with the TB-score was detected after albendazole treatment of helminth-positive TB patients compared to placebo. However, significant changes were observed in specific immunological responses such as reduced eosinophil counts and a trend towards lower levels of IL-10 producing cells. At baseline, helminth co-infected TB patients exhibited an increased Treg response as well as an increased IL-5 and spontaneous IL-10 production.

    Nyckelord
    Regulatory T-cells, helminth, tuberculosis, albendazole, deworming, Ethiopia, HIV
    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-91827 (URN)
    Tillgänglig från: 2013-05-02 Skapad: 2013-05-02 Senast uppdaterad: 2013-05-02Bibliografiskt granskad
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    The impact of helminth infection in patients with active tuberculosis
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  • 92.
    Abate, Ebba
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Belayneh, Meseret
    University of Addis Ababa, Ethiopia .
    Gelaw, Aschalew
    University of Gondar, Ethiopia .
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Getachew, Assefa
    University of Gondar, Ethiopia .
    Alemu, Shitaye
    University of Gondar, Ethiopia .
    Diro, Ermias
    University of Gondar, Ethiopia .
    Fikre, Nigussu
    University of Addis Ababa, Ethiopia .
    Britton, Sven
    Karolinska Hospital, Sweden .
    Elias, Daniel
    University of So Denmark, Denmark .
    Aseffa, Abraham
    Armauer Hansen Research Institute, Ethiopia .
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    The Impact of Asymptomatic Helminth Co-Infection in Patients with Newly Diagnosed Tuberculosis in North-West Ethiopia2012Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 7, nr 8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Areas endemic of helminth infection, tuberculosis (TB) and HIV are to a large extent overlapping. The aim of this study was to assess the impact of asymptomatic helminth infection on the immunological response among TB patients with and without HIV, their house hold contacts and community controls. less thanbrgreater than less thanbrgreater thanMethodology: Consecutive smear positive TB patients (n = 112), their household contacts (n = 71) and community controls (n = 112) were recruited in Gondar town, Ethiopia. Stool microscopy, HIV serology, serum IgE level, eosinophil and CD4 counts were performed and tuberculosis patients were followed up for 3 months after initiation of anti-TB treatment. less thanbrgreater than less thanbrgreater thanResults: Helminth co-infection rate was 29% in TB patients and 21% in both community control and household contacts (p = 0.3) where Ascaris lumbricoides was the most prevalent parasite. In TB patients the seroprevalence of HIV was 47% (53/112). Eosinophilia and elevated IgE level were significantly associated with asymptomatic helminth infection. During TB treatment, the worm infection rate of HIV+/TB patients declined from 31% (10/32) at week 0 to 9% (3/32) at week 2 of TB treatment, whereas HIV2/TB patients showed no change from baseline to week 2, 29% (13/45) vs. 22.2% (10/45). This trend was stable at week 8 and 12 as well. less thanbrgreater than less thanbrgreater thanConclusion: One third of smear positive TB patients were infected with helminths. Eosinophilia and elevated IgE level correlated with asymptomatic worm infection, indicating an effect on host immunity. The rate of worm infection declined during TB treatment in HIV+/TB co-infected patients whereas no decline was seen in HIV2/TB group.

    Ladda ner fulltext (pdf)
    fulltext
  • 93.
    Abate, Ebba
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. University of Gondar, Ethiopia.
    Belayneh, Meseret
    University of Addis Ababa, Ethiopia.
    Idh, Jonna
    Vastervik Hospital, Sweden.
    Diro, Ermias
    University of Gondar, Ethiopia.
    Elias, Daniel
    University of Southern Denmark, Denmark.
    Britton, Sven
    Karolinska Hospital, Sweden.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Kalmar County Hospital, Sweden.
    Asymptomatic Helminth Infection in Active Tuberculosis Is Associated with Increased Regulatory and Th-2 Responses and a Lower Sputum Smear Positivity2015Ingår i: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 9, nr 8, artikel-id e0003994Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background The impact of intestinal helminth infection on the clinical presentation and immune response during active tuberculosis (TB) infection is not well characterized. Our aim was to investigate whether asymptomatic intestinal helminth infection alters the clinical signs and symptoms as well as the cell mediated immune responses in patients with active TB.

    Methodology Consecutive, newly diagnosed TB patients and healthy community controls (CCs) were recruited in North-west Ethiopia. TB-score, body mass index and stool samples were analyzed. Cells from HIV-negative TB patients (HIV-/TB) and from CCs were analyzed for regulatory T-cells (Tregs) and cytokine responses using flow cytometry and ELISPOT, respectively.

    Results A significantly higher ratio of helminth co-infection was observed in TB patients without HIV (Helm+/HIV-/TB) compared to HIV negative CCs, (40% (121/306) versus 28% (85/306), p = 0.003). Helm+/HIV-/TB patients showed significantly increased IL-5 secreting cells compared to Helm-/HIV-/TB (37 SFU (IQR:13-103) versus 2 SFU (1-50); p = 0.02, n = 30). Likewise, levels of absolute Tregs (9.4 (3.2-16.7) cells/mu l versus 2.4 (1.1-4.0) cells/mu l; p = 0.041) and IL-10 secreting cells (65 SFU (7-196) versus 1 SFU (0-31); p = 0.014) were significantly higher in Helm+/HIV-/TB patients compared to Helm-/HIV-/TB patients. In a multivariate analysis, a lower rate of sputum smear positivity for acid fast bacilli, lower body temperature, and eosinophilia were independently associated with helminth infection in TB patients.

    Conclusions Asymptomatic helminth infection is associated with increased regulatory T-cell and Th2-type responses and a lower rate of sputum smear positivity. Further studies are warranted to investigate the clinical and immunological impact of helminth infection in TB patients.

    Ladda ner fulltext (pdf)
    fulltext
  • 94.
    Abate, Ebba
    et al.
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia; Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Elias, Daniel
    University of Southern Denmark, Institute of Molecular Medicine, Department of cancer and inflammation, Odense, Denmark.
    Getachew, Assefa
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Alemu, Shitaye
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Diro, Ermias
    Department of Radiology, University of Gondar, Gondar, Ethiopia.
    Britton, Sven
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Effects of albendazole treatment on the clinical outcome and immunological responses in patients with helminth infection and pulmonary tuberculosis: a randomized clinical trial2013Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: The impact of helminth infection on the host immune response to tuberculosis (TB) has been characterized in experimental models but less so in the clinical setting. The objective of this study was to investigate the impact of deworming on the clinical outcome and cell mediated immune response in active TB.

    Methods: Newly diagnosed pulmonary TB patients in Gondar, Ethiopia were examined for helminth infection. Helminth-positive TB patients (W+/TB) were randomized to albendazole (400mg X III per os) or placebo. The primary outcome was change in TB-score after 2 months, and secondary outcomes were sputum smear conversion at the 2nd month, and changes in chest x-ray pattern, CD4+ T-cell count, eosinophil count, IgE-levels and immunological responses after 3 months. In a subset of W+/TB, W-/TB patients and healthy controls, flow cytometry and ELISPOT assays were used to characterize the regulatory T-cell population (Tregs) and the frequency of PPD- stimulated IFN-γ, IL-5 and IL-10 producing peripheral blood mononuclear cells (PBMCs).

    Results: A total of 140 helminth co-infected TB patients were included with an HIV coinfection rate of 22.8 %. Following albendazole treatment of the W+/TB patients, there was a significant decrease in helminth infection compared to placebo (8% (4/49) vs. 48 % (22/46), p<0.001). No significant effect was observed for albendazole compared to placebo on the primary outcome as evaluated by the TB-score (5.6 ±2.87 vs. 5.87 ±2.54, p=0.59). Eosinophil counts decreased significantly in the albendazole group. In a subgroup analysis of helminthnegative patients following albendazole treatment versus placebo, the albendazole group showed a trend for lower levels of IL-10 producing cells at month three (p=0.08). At baseline, W+/TB patients had a significantly higher mean level of Tregs (% Tregs/CD4+) compared to W-/TB patients and helminth-positive community controls. Additionally, the frequency of IFN-γ, IL-5 and spontaneous IL-10 levels was increased in helminth-positive compared to helminth-negative TB patients.

    Conclusions: No significant effects on the clinical outcome as measured with the TB-score was detected after albendazole treatment of helminth-positive TB patients compared to placebo. However, significant changes were observed in specific immunological responses such as reduced eosinophil counts and a trend towards lower levels of IL-10 producing cells. At baseline, helminth co-infected TB patients exhibited an increased Treg response as well as an increased IL-5 and spontaneous IL-10 production.

  • 95.
    Abate, Ebba
    et al.
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia; Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Idh, Jonna
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Belayneh, Meseret
    School of Medical Laboratory Sciences, Medical Faculty, Addis Ababa University, Addis Ababa.
    Getachew, Assefa
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Alemu, Shitaye
    Gondar College of Medical and Health Sciences, Gondar University, Gondar, Ethiopia.
    Diro, Ermias
    Department of Radiology, University of Gondar, Gondar, Ethiopia.
    Britton, Sven
    Department of Infectious Diseases, Karolinska Hospital, Stockholm, Sweden.
    Elias, Daniel
    University of Southern Denmark, Institute of Molecular Medicine, Department of cancer and inflammation, Odense, Denmark.
    Aseffa, Abraham
    Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
    Stendahl, Olle
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Schön, Thomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Medicinsk mikrobiologi. Linköpings universitet, Hälsouniversitetet.
    Impact of helminth infection on the clinical presentation 1 of pulmonary tuberculosis2013Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: The effects of helminth infection on chronic infectious diseases such as HIV and tuberculosis (TB) merit further characterization. Thus, we assessed the baseline clinical characteristics of helminth infection in patients with active TB in a high endemic area.

    Methodology: Consecutive, newly diagnosed TB patients were recruited from three health institutions in the north Gondar administrative zone, Ethiopia. Structured questionnaires were used to collect socio-demographic and clinical characteristics. Additionally, the TB score, mid upper arm circumference, body mass index (BMI), BCG vaccination status, stool and sputum microscopy as well as HIV serology and CD4+T cells counts were evaluated.

    Results: A total of 377 pulmonary TB patients were included in the study. The helminth co infection rate was 33% (123/377) and the most prevalent parasite was Ascaris lumbricoides (53%, 65/123). The HIV co-infection rate was 29% (110/377). Seventy percent (77/110) of the HIV co-infected patients were on anti- retroviral therapy at the time of TB diagnosis. Helminth infection was more prevalent in HIV-negative TB patients compared to HIV-positive TB patients (p=0.025). Smoking and walking bare foot were independently associated to helminth infection in TB patients after adjusting for the influence of HIV. Other than increased eosinophilia, no other significant differences were observed between helminth positive and helminth negative TB patients in the clinical presentation including the TB score, CD4+T-cells, BMI or bacterial load.

    Conclusion: The clinical presentation of active pulmonary tuberculosis was not affected by helminth infection. Helminth infection was less frequent among HIV-positive TB patients and this finding merits further investigation.

  • 96.
    Abate Waktola, Ebba Abate
    et al.
    Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. EPHI, Ethiopia.
    Blomgran, Robert
    Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation.
    Verma, Deepti
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation.
    Lerm, Maria
    Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation.
    Fredrikson, Mats
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för neuro- och inflammationsvetenskap. Linköpings universitet, Medicinska fakulteten.
    Belayneh, Meseret
    Univ Addis Abeba, Ethiopia.
    Söderkvist, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk genetik.
    Stendahl, Olle
    Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation.
    Schön, Thomas
    Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi, infektion och inflammation. Kalmar County Hospital, Kalmar, Sweden.
    Polymorphisms in CARD8 and NLRP3 are associated with extrapulmonary TB and poor clinical outcome in active TB in Ethiopia2019Ingår i: Scientific Reports, E-ISSN 2045-2322, Vol. 9, artikel-id 3126Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Innate immunity is a first line defense against Mycobacterium tuberculosis infection where inflammasome activation and secretion of the pro-inflammatory cytokine IL-1beta, plays a major role. Thus, genetic polymorphisms in innate immunity-related genes such as CARD8 and NLRP3 may contribute to the understanding of why most exposed individuals do not develop infection. Our aim was to investigate the association between polymorphisms in CARD8 and NLRP3 and active tuberculosis (TB) as well as their relationship to treatment outcome in a high-endemic setting for TB. Polymorphisms in CARD8 (C10X) and NLRP3 (Q705K) were analysed in 1190 TB patients and 1990 healthy donors (HD). There was a significant association between homozygotes in the CARD8 polymorphism and extrapulmonary TB (EPTB), which was not the case for pulmonary TB or HDs. Among TB-patients, there was an association between poor treatment outcome and the NLRP3 (Q705K) polymorphism. Our study shows that inflammasome polymorphisms are associated with EPTB and poor clinical outcome in active TB in Ethiopia. The practical implications and determining causal relationships on a mechanistic level needs further study.

    Ladda ner fulltext (pdf)
    fulltext
  • 97.
    Abbas Abdulmehdi, Iman
    Linköpings universitet, Institutionen för kultur och samhälle.
    Waiting for Godot: A Play in Which the Main Characters' Lives Are Presented As Meaningless2023Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The objective of this argumentative paper is to study the play Waiting for Godot from a specific point of view. The statement of this thesis is that the lives of Vladimir and Estragon are presented as meaningless, and this claim is based on the analysis of the play and the study of other published scholarship that is associated with the topic. The thesis is divided into three chapters, each chapter discusses each argument and shed light on some philosophical concepts such as Existentialism, Absurdisim, and Nihilism. However, the main focus is on the fundamental meaning of the lives of the main characters, Vladimir and Estragon.

    Ladda ner fulltext (pdf)
    fulltext
  • 98.
    Abbas, Ashraf H.
    et al.
    Plastic Surgery Unit, Surgery Dept., Suez Canal University, Ismailia, Egypt.
    Elmasry, Moustafa
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Hand- och plastikkirurgiska kliniken US. Plastic Surgery Unit, Surgery Dept., Suez Canal University, Ismailia, Egypt.
    Steinvall, Ingrid
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Hand- och plastikkirurgiska kliniken US.
    Adly, Osama A.
    Plastic Surgery Unit, Surgery Dept., Suez Canal University, Ismailia, Egypt.
    Elbadawy, Mohamed A.
    Plastic Surgery Unit, Surgery Dept., Suez Canal University, Ismailia, Egypt.
    Moati, Taha Ali
    General Surgery department, Suez Canal University, Ismailia, Egypt.
    Sjöberg, Folke
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för kliniska vetenskaper. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Sinnescentrum, Hand- och plastikkirurgiska kliniken US. Region Östergötland, Sinnescentrum, Anestesi- och intensivvårdskliniken US.
    Aesthetic Outcome After Reconstruction of Complex SoftTissue Defects with Free Antero-Lateral Thigh Flap UsingSimple Equipment2015Ingår i: Journal of surgery, ISSN 2330-0914, Vol. 3, nr 2-1, s. 36-41Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: We aimed to assess the aesthetic outcome of surgical reconstruction by free ALT flap using binocular single-refraction magnifying glasses and a modified post- operative surveillance protocol. Methods: 16 patients were operated for free antero-lateral thigh flap to reconstruct complex soft tissue defects with a close clinical follow up protocol for post operative care depending on the attending personnel in the Plastic surgery unit, Suez Canal University hospital, Ismailia, Egypt. Aesthetic outcome was assessed using a questionnaire based on Posch et al. 2005, including the following items colour, contour, presence of hair, overall appearance and donor site scar. Results: The patients’ assessed aesthetic outcome was acceptable in majority of the cases; median score was 4 for all assessed items. Complete flap loss occurred in one case, other complications as arterial thrombosis and hematomas and infection were detected and managed accordingly with flap salvage in the 3 complicated cases. Conclusion: The result suggests that the proposed protocol is sufficient as an alternative. The aesthetic outcome assessed by the patient and the failure rate was in line with other studies.

  • 99.
    Abbas, Malik Waseem
    et al.
    Natl Inst Biotechnol and Genet Engn, Pakistan.
    Soomro, Razium Ali
    Natl Inst Biotechnol and Genet Engn, Pakistan; Univ Sindh, Pakistan; Univ Bristol, England.
    Kalwar, Nazar Hussain
    Shah Abdul Latif Univ, Pakistan.
    Zahoor, Mehvish
    Natl Inst Biotechnol and Genet Engn, Pakistan.
    Avci, Ahmet
    Selcuk Univ, Turkey.
    Pehlivan, Erol
    Selcuk Univ, Turkey.
    Hallam, Keith Richard
    Univ Bristol, England.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Carbon quantum dot coated Fe3O4 hybrid composites for sensitive electrochemical detection of uric acid2019Ingår i: Microchemical journal (Print), ISSN 0026-265X, E-ISSN 1095-9149, Vol. 146, s. 517-524Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The study explores carbon quantum dots (C-dots) as potential candidates for enhancing the signal sensitivity of an electrochemical sensor devised for biologically important molecule, such as uric acid (UA). The C-dots were evaluated for their electrochemical characteristics in combination with Fe3O4 nanoparticles (Fe3O4 NPs), which were applied as the primary electro-catalytic promoter. The hybrid nanocomposite (C-dots/Fe3O4 HCs) formation was achieved by facilitating the adsorption of C-dots over Fe3O4 NPs using amine-carbonyl interactions. Unlike, one pot method, the proposed strategy enables aggregation-free coverage of Fe3O4 NPs with highly conductive layer of C-dots that can act as conduction centres to support ultra-fast electron transfer kinetics to satisfy the need of high signal sensitivity. The hybrid composite demonstrated remarkable signal improvement when tested against the electrochemical oxidation of UA. The heighten current response and lower over-potential values enabled development of a DC-amperometric (DC-AMP) sensor for UA with a linear working range of 0.01 to 0.145 mu M and signal sensitivity measurable up to 6.0 x 10(-9) M. The said improvement was manifested as a synergetic outcome of active redox couple (Fe (III/II)), larger surface area of Fe3O4 NPs engulfed with a layer of highly conductive C-dots acting as efficient charge sensitisers.

  • 100. Beställ onlineKöp publikationen >>
    Abbas, Muhammad
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    On the Implementation of Integer and Non-Integer Sampling Rate Conversion2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The main focus in this thesis is on the aspects related to the implementation of integer and non-integer sampling rate conversion (SRC). SRC is used in many communication and signal processing applications where two signals or systems having different sampling rates need to be interconnected. There are two basic approaches to deal with this problem. The first is to convert the signal to analog and then re-sample it at the desired rate. In the second approach, digital signal processing techniques are utilized to compute values of the new samples from the existing ones. The former approach is hardly used since the latter one introduces less noise and distortion. However, the implementation complexity for the second approach varies for different types of conversion factors. In this work, the second approach for SRC is considered and its implementation details are explored. The conversion factor in general can be an integer, a ratio of two integers, or an irrational number. The SRC by an irrational numbers is impractical and is generally stated for the completeness. They are usually approximated by some rational factor.

    The performance of decimators and interpolators is mainly determined by the filters, which are there to suppress aliasing effects or removing unwanted images. There are many approaches for the implementation of decimation and interpolation filters, and cascaded integrator comb (CIC) filters are one of them. CIC filters are most commonly used in the case of integer sampling rate conversions and often preferred due to their simplicity, hardware efficiency, and relatively good anti-aliasing (anti-imaging) characteristics for the first (last) stage of a decimation (interpolation). The multiplierless nature, which generally yields to low power consumption, makes CIC filters well suited for performing conversion at higher rate. Since these filters operate at the maximum sampling frequency, therefore, are critical with respect to power consumption. It is therefore necessary to have an accurate and efficient ways and approaches that could be utilized to estimate the power consumption and the important factors that are contributing to it. Switching activity is one such factor. To have a high-level estimate of dynamic power consumption, switching activity equations in CIC filters are derived, which may then be used to have an estimate of the dynamic power consumption. The modeling of leakage power is also included, which is an important parameter to consider since the input sampling rate may differ several orders of magnitude. These power estimates at higher level can then be used as a feed-back while exploring multiple alternatives.

    Sampling rate conversion is a typical example where it is required to determine the values between existing samples. The computation of a value between existing samples can alternatively be regarded as delaying the underlying signal by a fractional sampling period. The fractional-delay filters are used in this context to provide a fractional-delay adjustable to any desired value and are therefore suitable for both integer and non-integer factors. The structure that is used in the efficient implementation of a fractional-delay filter is know as Farrow structure or its modifications. The main advantage of the Farrow structure lies in the fact that it consists of fixed finite-impulse response (FIR) filters and there is only one adjustable fractional-delay parameter, used to evaluate a polynomial with the filter outputs as coefficients. This characteristic of the Farrow structure makes it a very attractive structure for the implementation. In the considered fixed-point implementation of the Farrow structure, closed-form expressions for suitable word lengths are derived based on scaling and round-off noise. Since multipliers share major portion of the total power consumption, a matrix-vector multiple constant multiplication approach is proposed to improve the multiplierless implementation of FIR sub-filters.

    The implementation of the polynomial part of the Farrow structure is investigated by considering the computational complexity of different polynomial evaluation schemes. By considering the number of operations of different types, critical path, pipelining complexity, and latency after pipelining, high-level comparisons are obtained and used to short list the suitable candidates. Most of these evaluation schemes require the explicit computation of higher order power terms. In the parallel evaluation of powers, redundancy in computations is removed by exploiting any possible sharing at word level and also at bit level. As a part of this, since exponents are additive under multiplication, an ILP formulation for the minimum addition sequence problem is proposed.

    Delarbeten
    1. Power Estimation of Recursive and Non-Recursive CIC Filters Implemented in Deep-Submicron Technology
    Öppna denna publikation i ny flik eller fönster >>Power Estimation of Recursive and Non-Recursive CIC Filters Implemented in Deep-Submicron Technology
    2010 (Engelska)Ingår i: Proceedings of International Conference on Green Circuits and Systems (ICGCS), 2010, Date: 21-23 June, 2010, IEEE , 2010, s. 221-225Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    The power modeling of different realizations of cascaded integrator-comb (CIC) decimation filters has been a subject of several recent works. In this work we have extended these with modeling of leakage power, which is an important factor since the input sample rate may differ several orders of magnitude. Furthermore, we have pointed out the importance of the input wordlength on the comparison of recursive and nonrecursive implementations.

    Ort, förlag, år, upplaga, sidor
    IEEE, 2010
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-70451 (URN)10.1109/ICGCS.2010.5543063 (DOI)978-1-4244-6877-5 (ISBN)978-1-4244-6876-8 (ISBN)
    Konferens
    International Conference on Green Circuits and Systems (ICGCS), June 21–23, Shanghai, China
    Tillgänglig från: 2011-09-20 Skapad: 2011-09-08 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    2. Switching Activity Estimation of CIC Filter Integrators
    Öppna denna publikation i ny flik eller fönster >>Switching Activity Estimation of CIC Filter Integrators
    2010 (Engelska)Ingår i: Proceedings of Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics (PrimeAsia), 2010, Date:22-24 Sept. 2010, IEEE , 2010, s. 21-24Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    In this work, a method for estimation of the switching activity in integrators is presented. To achieve low power, it is always necessary to develop accurate and efficient methods to estimate the switching activity. The switching activities are then used to estimate the power consumption. In our work, the switching activity is first estimated for the general purpose integrators and then it is extended for the estimation of switching activity in cascaded integrators in CIC filters.

    Ort, förlag, år, upplaga, sidor
    IEEE, 2010
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-70452 (URN)10.1109/PRIMEASIA.2010.5604971 (DOI)978-1-4244-6736-5 (ISBN)978-1-4244-6735-8 (ISBN)
    Konferens
    Asia Pacific Conference on Postgraduate Research in Microelectronics and Electronics (PrimeAsia), 22-24 September, Shanghai, China
    Anmärkning
    ©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. MUHAMMAD ABBAS and Oscar Gustafsson, Switching Activity Estimation of CIC Filter Integrators, 2010, Asia Pacific Conf. on Postgraduate Research in Microelectronics and Electronics, Shanghai, China. http://dx.doi.org/10.1109/PRIMEASIA.2010.5604971 Tillgänglig från: 2011-09-20 Skapad: 2011-09-08 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    3. Scaling of fractional delay filters based on the Farrow structure
    Öppna denna publikation i ny flik eller fönster >>Scaling of fractional delay filters based on the Farrow structure
    2009 (Engelska)Ingår i: Proceedings of IEEE International Symposium on Circuits and Systems, 2009. ISCAS 2009, Piscataway: IEEE , 2009, s. 489-492Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    In this work we consider scaling of fractional delay filters using the Farrow structure. Based on the observation that the subfilters approximate the Taylor expansion of a differentiator, we derive estimates of the L2-norm scaling values at the outputs of each subfilter as well as at the inputs of each delay multiplier. The scaling values can then be used to derive suitable wordlengths in a fixed-point implementation.

    Ort, förlag, år, upplaga, sidor
    Piscataway: IEEE, 2009
    Nationell ämneskategori
    Signalbehandling
    Identifikatorer
    urn:nbn:se:liu:diva-51070 (URN)10.1109/ISCAS.2009.5117792 (DOI)000275929800123 ()978-1-4244-3827-3 (ISBN)
    Konferens
    IEEE International Symposium on Circuits and Systems, 24-27 May 2009, Taipei,Taiwan
    Tillgänglig från: 2009-10-15 Skapad: 2009-10-15 Senast uppdaterad: 2018-09-01Bibliografiskt granskad
    4. Computational and Implementation Complexity of Polynomial Evaluation Schemes
    Öppna denna publikation i ny flik eller fönster >>Computational and Implementation Complexity of Polynomial Evaluation Schemes
    2011 (Engelska)Ingår i: Proceedings of NORCHIP, 2011 Date:14-15 Nov. 2011, IEEE conference proceedings, 2011, s. 1-6Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    In this work, we consider the computational complexity of different polynomial evaluation schemes. By considering the number of operations of different types, critical path, pipelining complexity, and latency after pipelining, high-level comparisons are obtained. These can then be used to short list suitable candidates for an implementation given the specifications. Not only multiplications are considered, but they are divided into data-data multiplications, squarers, and data-coefficient multiplications, as the latter can be optimized depending on implementation architecture and application.

    Ort, förlag, år, upplaga, sidor
    IEEE conference proceedings, 2011
    Nyckelord
    Adders, Computer architecture, Delay, Filtering algorithms, ISO, Pipeline processing, Polynomials
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-73935 (URN)10.1109/NORCHP.2011.6126735 (DOI)978-1-4577-0515-1 (ISBN)978-1-4577-0514-4 (ISBN)
    Konferens
    NORCHIP 2011. The Nordic Microelectronics event, 29th Norchip Conference 14-15 November 2011, Lund, Sweden
    Tillgänglig från: 2012-01-17 Skapad: 2012-01-17 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    5. Low-Complexity Parallel Evaluation of Powers Exploiting Bit-Level Redundancy
    Öppna denna publikation i ny flik eller fönster >>Low-Complexity Parallel Evaluation of Powers Exploiting Bit-Level Redundancy
    2010 (Engelska)Ingår i: Conference Record of the Forty Fourth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2010, 7-10 Nov. 2010 / [ed] Michael B. Matthews, Washington, DC, USA: IEEE Computer Society , 2010, s. 1168-1172Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    In this work, we investigate the problem of computing any requested set of power terms in parallel using summations trees. This problem occurs in applications like polynomial approximation, Farrow filters (polynomial evaluation part) etc. In the proposed technique, the partial product of each power term is initially computed independently. A redundancy check is then made in each and among all partial products matrices at bit level. The redundancy here relates to the fact that same three partial products may be present in more than one columns, and, hence, can be mapped to the same full adder. The proposed algorithm is tested for different sets of powers and wordlengths to exploit the sharing potential.

    Ort, förlag, år, upplaga, sidor
    Washington, DC, USA: IEEE Computer Society, 2010
    Serie
    Asilomar Conference on Signals, Systems and Computers. Conference Record, ISSN 1058-6393
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-70453 (URN)10.1109/ACSSC.2010.5757714 (DOI)978-1-4244-9722-5 (ISBN)
    Konferens
    Signals, Systems and Computers (ASILOMAR), 2010, 7-10 Nov. 2010 , Pacific Grove, CA, USA
    Tillgänglig från: 2011-09-20 Skapad: 2011-09-08 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    6. Integer Linear Programming Modeling of Addition Sequences With Additional Constraints for Evaluation of Power Terms
    Öppna denna publikation i ny flik eller fönster >>Integer Linear Programming Modeling of Addition Sequences With Additional Constraints for Evaluation of Power Terms
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In this work, an integer linear programming (ILP) based model is proposed for the computation of a minimal cost addition sequence for a given set of integers. Since exponents are additive under multiplication, the minimal length addition sequence will provide an optimal solution for the evaluation of a requested set of power terms. This in turn finds application in, e.g., window-based exponentiation for cryptography and polynomial evaluation. Not only is an optimal model proposed, the model is extended to consider different costs for multipliers and squarers as well as controlling the depth of the resulting addition sequence.

    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-73936 (URN)
    Tillgänglig från: 2012-01-17 Skapad: 2012-01-17 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    7. Switching Activity Estimation of DDFS Phase Accumulators
    Öppna denna publikation i ny flik eller fönster >>Switching Activity Estimation of DDFS Phase Accumulators
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    In this letter, equations for the one’s probability and switching activities for direct digital frequency synthesis (DDFS) phase accumulators are derived. These results are useful for obtaining good accuracy estimated of both leakage and dynamic power consumption for the phase accumulator and the phase-to-magnitude converter.

    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-73937 (URN)
    Tillgänglig från: 2012-01-17 Skapad: 2012-01-17 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    Ladda ner fulltext (pdf)
    On the Implementation of Integer and Non-Integer Sampling Rate Conversion
    Ladda ner (pdf)
    omslag
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