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  • Kühnemund, Malte
    et al.
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Stockholm Univ, Dept Biophys & Biochem, Sci Life Lab, SE-17165 Solna, Sweden..
    Hernandez-Neuta, Ivan
    Stockholm Univ, Dept Biophys & Biochem, Sci Life Lab, SE-17165 Solna, Sweden..
    Sharif, Mohd Istiaq
    Stockholm Univ, Dept Biophys & Biochem, Sci Life Lab, SE-17165 Solna, Sweden..
    Cornaglia, Matteo
    Ecole Polytech Fed Lausanne, Lab Microsyst, CH-1015 Lausanne, Switzerland..
    Gijs, Martin A. M.
    Ecole Polytech Fed Lausanne, Lab Microsyst, CH-1015 Lausanne, Switzerland..
    Nilsson, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Uppsala University, Science for Life Laboratory, SciLifeLab. Stockholm Univ, Dept Biophys & Biochem, Sci Life Lab, SE-17165 Solna, Sweden..
    Sensitive and inexpensive digital DNA analysis by microfluidic enrichment of rolling circle amplified single-molecules2017In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 45, no 8, e59Article in journal (Refereed)
    Abstract [en]

    Single molecule quantification assays provide the ultimate sensitivity and precision for molecular analysis. However, most digital analysis techniques, i.e. droplet PCR, require sophisticated and expensive instrumentation for molecule compartmentalization, amplification and analysis. Rolling circle amplification (RCA) provides a simpler means for digital analysis. Nevertheless, the sensitivity of RCA assays has until now been limited by inefficient detection methods. We have developed a simple microfluidic strategy for enrichment of RCA products into a single field of view of a low magnification fluorescent sensor, enabling ultra-sensitive digital quantification of nucleic acids over a dynamic range from 1.2 aM to 190 fM. We prove the broad applicability of our analysis platform by demonstrating 5-plex detection of as little as similar to 1 pg (similar to 300 genome copies) of pathogenic DNA with simultaneous antibiotic resistance marker detection, and the analysis of rare oncogene mutations. Our method is simpler, more cost-effective and faster than other digital analysis techniques and provides the means to implement digital analysis in any laboratory equipped with a standard fluorescent microscope.

  • Mellhorn, Malin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Water hyacinths (Eichornia crassipes) and their presence in Shire River, Malawi: Problems caused by them and ways of utilise them elsewhere2013Student paper other, 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Malawi is one of many countries throughout the world struggling with massive amounts of water hyacinths (Eichornia crassipes) in the country’s fresh water resources.  In nutrient-rich ecosystems where the aquatic weed has no natural enemies it will reproduce very rapidly with the consequence that lakes become overgrown, water flow in rivers is reduced, and other water organisms becomes excluded. At the same time, the plants form a good breeding place for species carrying tropical diseases for example Malaria and Bilharzia. Water hyacinths are usually more of a problem for poorer countries since there are often great economic losses caused by the weed and to control their relative abundance is costly.

    In Malawi, 99 % of the produced electricity is based on water resources, mainly through hydropower turbines in the main river, Shire River. Water hyacinths, aggregated as islands, floating along the river and clogging the turbines cause repeated electricity black-outs and approximately 140 megawatt power is lost every day. To counter the weed interference with the electricity supply, there are great amounts of water hyacinths harvested every day and dumped along the road, with no further disposal plan. In this report, soil from one local dumping area is analysed to determine if such places are leaching nutrients or metals to the surrounding environment. 

    Water hyacinths contain naturally high values of nutrients and farmers use these harvested plants as a green manure to improve soil properties on agricultural land. This paper aims to examine levels of metal in water hyacinths used as green manure. This is of interest since water hyacinths have the ability to effectively absorb substances from the water body which could pose a risk for potentially toxic elements (PTEs) to accumulate in the agricultural soil and subsequently in crops.

    Sampling and analyses were carried out with standard methods. Metal and nutrient levels in the analysed samples were obtained through detection with atomic absorption spectrophotometry (AAS), ion chromatography (IC) and UV/VIS spectrophotometry at the Department of Chemistry of Chancellor College in Zomba, Malawi.

    None of the investigated metal ions (Cr, Pb, Cd) were found in the analysed water hyacinths and since soil sampling was done during the dry season this thesis cannot determine if the dumping areas are leaching nutrients. Relatively high amounts of total phosphorus were found in the plants. Overall, the conclusion is that there is no risk of using water hyacinths harvested in Shire River as a green manure on agricultural land. 

  • Public defence: 2017-06-13 10:15 Hörsal 2, Ekonomikum, Uppsala
    Escobar, Sebastian
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Economics.
    Essays on inheritance, small businesses and energy consumption2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Essay 1: People’s planning to evade the inheritance tax curtails its merits. However, the extent of planning remains a matter of argument. According to popular belief, it is widespread, but few estimates have been presented. This study estimates the extent of estate size under-reporting, a form of inheritance tax planning, using the repeal of the Swedish tax on spousal bequests, in 2004, and a regression discontinuity design. The results show that, on average, estate sizes were 17 percent lower, and the share of estates that completely escaped tax payments was 26 percent larger due to under-reporting. As a consequence, government revenues from the tax were only half of what they would have been without under-reporting. Moreover, preferences and means for under-reporting were not only prevalent among the wealthy, but also among those receiving relatively small inheritances. The study contributes to a growing literature on tax avoidance and evasion by estimating the extent of estate size under-reporting, its effect on government revenues and by showing that it was widespread in the population.

  • Public defence: 2017-06-14 13:00 Å4001, Uppsala
    Pereira, Raul
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.
    Correlation Functions in Integrable Theories: From weak to strong coupling2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The discovery of integrability in planar N=4 super Yang-Mills and ABJM has enabled a precise study of AdS/CFT. In the past decade integrability has been successfully applied to the spectrum of anomalous dimensions, which can now be obtained at any value of the coupling. However, in order to solve conformal field theories one also needs to understand their structure constants. Recently, there has been great progress in this direction with the all-loop proposal of Basso, Komatsu and Vieira. But there is still much to understand, as it is not yet possible to use that formalism to find structure constants of short operators at strong coupling. It is important to study wrapping corrections and resum them as the TBA did for the spectrum. It is also crucial to obtain perturbative data that can be used to check if the all-loop proposal is correct or if there are new structures that need to be unveiled.

    In this thesis we compute several structure constants of short operators at strong coupling, including the structure constant of Konishi with half-BPS operators. Still at strong coupling, we find a relation between the building blocks of superstring amplitudes and the tensor structures allowed by conformal symmetry. We also consider the case of extremal correlation functions and the relation of their poles to mixing with double-trace operators.

    We also study three-point functions at weak coupling. We take the OPE limit in a four-point function of half-BPS operators in order to shed some light on the structure of five-loop wrapping corrections of the Hexagon form factors. Finally, we take the first steps in the generalization of the Hexagon programme to other theories. We find the non-extremal setup in ABJM and the residual symmetry that it preserves, which we use to fix the two-particle form factor and constrain the four-particle hexagon. Finally, we find that the Watson equations hint at a dressing phase that needs to be further investigated.

    List of papers
    1. Computing Three-Point Functions for Short Operators
    Open this publication in new window or tab >>Computing Three-Point Functions for Short Operators
    2014 (English)In: Journal of High Energy Physics (JHEP), ISSN 1029-8479, E-ISSN 1126-6708, no 3, 096- p.Article in journal (Refereed) Published
    Abstract [en]

    We compute the three-point structure constants for short primary operators of N=4 super Yang-Mills theory to leading order in the inverse coupling by mapping the problem to a flat-space string theory calculation. We check the validity of our procedure by comparing to known results for three chiral primaries. We then compute the three-point functions for any combination of chiral and non-chiral primaries, with the non-chiral primaries all dual to string states at the first massive level. Along the way we find many cancellations that leave us with simple expressions, suggesting that integrability is playing an important role.

    National Category
    Subatomic Physics
    Research subject
    Theoretical Physics
    Identifiers
    urn:nbn:se:uu:diva-218834 (URN)10.1007/JHEP03(2014)096 (DOI)000347830500001 ()
    Available from: 2014-02-18 Created: 2014-02-18 Last updated: 2017-04-26Bibliographically approved
    2. Three-point correlators from string amplitudes: mixing and Regge spins
    Open this publication in new window or tab >>Three-point correlators from string amplitudes: mixing and Regge spins
    2015 (English)In: Journal of High Energy Physics (JHEP), ISSN 1029-8479, E-ISSN 1126-6708, no 4, 134Article in journal (Refereed) Published
    Abstract [en]

    This paper has two parts. We first compute the leading contribution to the strong-coupling mixing between the Konishi operator and a double-trace operator composed of chiral primaries by using flat-space vertex operators for the string-duals of the operators. We then compute the three-point functions for protected or unprotected scalar operators with higher spin operators on the leading Regge trajectory. Here we see that the nontrivial spatial structures required by conformal invariance arise naturally from the form of the polarization tensors in the vertex operators. We find agreement with recent results extracted from Mellin amplitudes for four-point functions, as well as with earlier supergravity calculations. We also obtain some new results for other combinations of operators.

    Keyword
    Supersymmetric gauge theory, Superstrings and Heterotic Strings, AdS-CFT Correspondence, Strong Coupling Expansion
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-255290 (URN)10.1007/JHEP04(2015)134 (DOI)000353519700002 ()
    Funder
    Swedish Research Council, 2012-3269
    Available from: 2015-06-22 Created: 2015-06-15 Last updated: 2017-04-26Bibliographically approved
  • Eriksen Tell, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Structural Investigations of HiPIMS-deposited Diamond-Like Carbon Thin Films using Raman Spectroscopy2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Diamond-like carbon (DLC) is a versatile material which exhibits excellentmechanical, electrical and optical properties making it suitable for applications rangingfrom biomedical implants to engine components. The properties of DLC thin films aredetermined by the bonding configuration (sp3/sp2 fraction) of its carbon atoms. Inorder to prepare DLC thin films for desired applications, it is essential to control andestimate the sp3/sp2 fraction precisely.

    Raman spectroscopy is widely employed for the estimation of sp3/sp2 fraction due toits non-destructive nature, high probing depth and possibility of quick acquisition. Thequality of information obtained from Raman analysis depends largely on the structureof DLC thin films, which varies from one deposition method to another. Using theexisting approaches for the estimation of sp3/sp2 fraction for a particular type of DLCthin films could entail large errors and thereby result in misleading conclusions. For anaccurate analysis of the film structure, it is therefore important that a carefullydesigned strategy is employed. In this work, Raman spectroscopy is employed forstructural investigation of DLC thin films deposited by High Power ImpulseMagnetron Sputtering (HiPIMS). Owing to the unique DLC film properties obtainedfrom HiPIMS, Raman spectroscopic investigations were made by developing ananalysis routine relevant for HiPIMS-deposited films. The developed approach isvalidated by complementary analysis of film density. The method is further employedfor investigating the compressive stress and thermal stability of the resulting films. Theanalyzed films were deposited using different buffer gas (Ar and Ne) and ion energy toproduce a range of sp2/sp3 ratios. Raman measurements were performed using visible(532 nm) and UV (325 nm) lasers. Film density was determined using X-RayReflectivity (XRR) and chemical composition using Elastic Recoil Detection Analysis(ERDA). The compressive stresses of the films were determined usingwafer-curvature method and thermal stability of the films was investigated byperforming Raman measurements on films annealed from 100 degrees C to 600degrees C.

    By developing an analysis routine and employing appropriate fitting method, it wasshown that the Full Width at Half Maximum (FWHM) of the G peak in the Ramanspectrum is the most relevant parameter for estimating the sp3/sp2 fraction. Theaccuracy of the analysis routine was verified by studying the evolution of sp3/sp2fraction and film density with respect to ion energy. The correlation between sp3/sp2fraction and film density was good. The differences in mass density and compressivestresses between Ar- and Ne-HiPIMS deposited films were also found to beconsistent with the estimated sp3/sp2 fractions. The structural evolution of theannealed films, investigated by Raman spectroscopy, showed that the Ne-HiPIMS filmsexhibit a transition from sp3 rich structure to sp2 rich structure at ~450 degrees Cwhereas the transition for the Ar-HiPIMS films occurs at ~300 degrees C. This impliesthat the Ne-HiPIMS films are thermally more stable than the Ar-HiPIMS films.

  • Falk Soylu, Denniz
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Applied Mathematics and Statistics.
    Recovery Rate Modelling of Non-performing Consumer Loans2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Luzhkova, Elena
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Languages, Department of Linguistics and Philology.
    Semantic categorization of body parts among English and Russian monolinguals and bilinguals2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Semantic typology and categorization are important fields of research in linguistics. The aim of our work is to inspect these fields in regard to bilingualism. In this thesis we examine semantic categorization of body parts among four different groups of people: monolingual English speakers, monolingual Russian speakers, bilingual Russian speakers answering in English and bilingual Russian speakers answering in Russian. The hierarchies, ambiguities in naming patterns and homology were in the center of this study. The groups were also compared to each other in order to observe the effects of the first language learned (L1) and the second language learned (L2) on bilinguals. The results showed that Russian L1 bilinguals answering the Russian questionnaire displayed the same results as the Russian monolinguals, indicating a lack of influence from the L2. The Russian L1 bilinguals answering the English questionnaire used a semantic categorization most similar to their L1 and also demonstrated a broadening of the semantic categories related to neither the L1 nor the L2.

  • Public defence: 2017-06-14 13:15 Hörsal 2, Uppsala
    Launberg, Anna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Business Studies.
    Creating value from science: Interaction between academia, business and healthcare in the Uppsala PET Centre case2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Recent decades have seen greater focus, both national and global, on universities’ role in boosting economic growth. Besides teaching and conducting research, universities are urged to contribute directly to the economy by commercialising research findings and interacting with industry.

    This thesis explores the dynamics and effects of such interplay by concentrating on a particular case of interaction involving Uppsala University, Uppsala University Hospital and a large multinational corporation. More specifically, the aim of the study was to investigate how use of science and value creation from science are affected when actors belonging to disparate spheres interact closely. The thesis recounts the evolution of the Uppsala PET Centre, established as a University research institute in 1989, which has served both as a site for pre-clinical and clinical research and as an important resource in routine clinical work. The whole Centre was commercialised when a large firm acquired it in 2002, only to be decommercialised and returned to the University and the University Hospital less than a decade later.

    Using a network perspective, this thesis analyses the journey of the Uppsala PET Centre by studying interfaces between physical and organisational resources. The basic argument is that to understand the effects of inter-sphere interaction on science use, one must consider the materiality of science and differences between the interacting actor spheres in terms of preferences, norms and goals – ‘schemes of valuation’ in the present work. The study shows that the materiality of science has a restrictive impact on flexibility of science use, and different actors’ simultaneous use of science is therefore severely constrained. Because of these constraints, the actor spheres involved struggle to control physical scientific resources in ways aligned with their particular schemes of valuation. Sharing, turn-taking and efforts to separate overlapping use contexts become the means of managing the restricted scope for science use.

    Further, this thesis demonstrates that while interfaces containing physical resources are controllable and always result in some kind of value (albeit not necessarily on the scale expected), the outcomes of combinations of organisational resources connected with disparate schemes of valuation are impossible to anticipate and control.

    The thesis concludes that there are reasons to rethink our expectations of the short-term economic and social effects of university–industry interaction, a complicated affair that encompasses opportunities and unforeseeable challenges alike.

  • Seidel, Linda
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Selin, Max
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Ser vi oss?: Om bilderbokens betydelse för arbetet med etnisk mångfald i förskolan2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vad finns det för böcker i förskolan idag, finns det en bok för alla där man kan känna igen sig i?  Barn behöver böcker i förskolan som väcker deras intresse för hur omvärlden ser ut idag med dess mångfald av etniciteter. Med detta som utgångspunkt har vi valt att studera hur pedagoger arbetar för att göra detta möjligt. Syftet med detta självständiga arbete är att undersöka hur förskollärare ser på etnisk mångfald i den barnlitteratur som finns tillgänglig för förskolor samt vilka resurser förskollärare använder sig av när det gäller urvalet av dessa böcker. Den datainsamlingsmetod vi använt oss av är kvalitativa intervjuer, dessa intervjuer ställs i relation till det sociokulturella perspektivet. Under arbetet presenterar nio förskollärares syn på etnicitet i bilderböcker. Resultatet som dels framkom i intervjuerna är, enligt förskollärarna i vår studie, att utbudet av bilderböcker med etniskt mångfaldsinslag är en bristvara i dagens förskola. Detta bekräftas i tidigare forskning. Inom detta arbete menar de förskollärare vi intervjuat att biblioteken är viktiga då de kan erbjuda stöd och hjälp i urvalet av barnböcker till verksamheten. Dessutom blir förskollärarna en viktig resurs som tar hjälp av biblioteken i att välja barnböcker. Studien tyder således på att lokala biblioteket har goda förutsättningar att vara den mest givande resursen när det kommer till att hitta etniska bilderböcker för barn.

  • Karlsson, Therése
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Monster och spöken: En analys av hur genus framställs i fem barnböcker där monster och spöken har en central roll2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att analysera genusperspektivet i fem utvalda barnböcker om monster och spöken där skildringen av kön inte alltid är uppenbar. För att kunna besvara syftet har några frågeställningar formats: På vilket sätt uttrycks kön hos monster och spöken i de utvalda barnböckerna? Hur framställs bildernas färg och form ur ett genusperspektiv? Hur framställs texten ur ett genusperspektiv? Jag har använt mig av en kvalitativ bildanalys som metod och de teoretiska utgångspunkterna är genusperspektiv och sociokulturellt perspektiv. Litteraturen som har granskats är de fem barnböckerna Monsterbesök, Ingrid och Ivar letar spöken, Monster finns faktiskt! Eller?, Bravo bli modig och Lilla spöket Laban.Resultatet av studien visar att kön framgår i alla granskade barnböcker trots att skildringen av kön inte behöver vara uppenbar. Monstrens och spökenas utseenden och attribut är i de flesta böckerna könstypiska och i vissa fall förstärks detta med hjälp av uttryck som rörelser, miner och kroppsspråk. Den skrivna texten tar upp beskrivande pronomen och namn som även de är lätta att koppla till ett visst kön.

  • Public defence: 2017-06-14 09:15 Room 2005, Uppsala
    Xu, Chao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Non-aqueous Electrolytes and Interfacial Chemistry in Lithium-ion Batteries2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lithium-ion battery (LIB) technology is currently the most promising candidate for power sources in applications such as portable electronics and electric vehicles. In today's state-of-the-art LIBs, non-aqueous electrolytes are the most widely used family of electrolytes. In the present thesis work, efforts are devoted to improve the conventional LiPF6-based electrolytes with additives, as well as to develop alternative lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI)-based electrolytes for silicon anodes. In addition, electrode/electrolyte interfacial chemistries in such battery systems are extensively investigated.

    Two additives, LiTDI and fluoroethylene carbonate (FEC), are evaluated individually for conventional LiPF6-based electrolytes combined with various electrode materials. Introduction of each of the two additives leads to improved battery performance, although the underlying mechanisms are rather different. The LiTDI additive is able to scavenge moisture in the electrolyte, and as a result, enhance the chemical stability of LiPF6-based electrolytes even at extreme conditions such as storage under high moisture content and at elevated temperatures. In addition, it is demonstrated that LiTDI significantly influences the electrode/electrolyte interfaces in NMC/Li and NMC/graphite cells. On the other hand, FEC promotes electrode/electrolyte interfacial stability via formation of a stable solid electrolyte interphase (SEI) layer, which consists of FEC-derivatives such as LiF and polycarbonates in particular.

    Moreover, LiTDI-based electrolytes are developed as an alternative to LiPF6 electrolytes for silicon anodes. Due to severe salt and solvent degradation, silicon anodes with the LiTDI-baseline electrolyte showed rather poor electrochemical performance. However, with the SEI-forming additives of FEC and VC, the cycling performance of such battery system is greatly improved, owing to a stabilized electrode/electrolyte interface.

    This thesis work highlights that cooperation of appropriate electrolyte additives is an effective yet simple approach to enhance battery performance, and in addition, that the interfacial chemistries are of particular importance to deeply understand battery behavior.

    List of papers
    1. LiTDI: A Highly Efficient Additive for Electrolyte Stabilization in Lithium-Ion Batteries
    Open this publication in new window or tab >>LiTDI: A Highly Efficient Additive for Electrolyte Stabilization in Lithium-Ion Batteries
    Show others...
    2017 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 29, no 5, 2254-2263 p.Article in journal (Refereed) Published
    Abstract [en]

    The poor stability of LiPF6-based electrolytes has always been a bottleneck for conventional lithium-ion batteries. The presence of inevitable trace amounts of moisture and the operation of batteries at elevated temperatures are particularly detrimental to electrolyte stability. Here, lithium 2trifluoromethy1-4,5-dicyanoimidazole (LiTDI) is investigated as a moisture-scavenging electrolyte additive and can sufficiently suppress the hydrolysis of LiPF6. With 2 wt % LiTDI, no LiPF6 degradation can be detected after storage for 35 days, even though the water level in the electrolyte is enriched by 2000 ppm. An improved thermal stability is also obtained by employing the LiTDI additive, and the moisture-scavenging mechanism is discussed. The beneficial effects of the LiTDI additive on battery performance are demonstrated by the enhanced capacity retention of both the LiNi1/3Mn1/3Co1/3O2 (NMC)/Li and NMC/graphite cells at 55 degrees C. In particular, the increase in cell voltage hysteresis is greatly hindered when LiTDI is presented in the electrolyte. Further development of the LiTDI additive may allow the improvement of elevated-temperature batteries, as well as energy savings by reducing the amount of effort necessary for dehydration of battery components.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2017
    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-319530 (URN)10.1021/acs.chemmater.6b05247 (DOI)000396639400040 ()
    Funder
    Swedish Energy Agency, 34191-1 39036-1Swedish Foundation for Strategic Research Carl Tryggers foundation
    Available from: 2017-04-06 Created: 2017-04-06 Last updated: 2017-04-26Bibliographically approved
    2. The Role of LiTDI Additive in LiNi1/3Mn1/3Co1/3O2/graphite Lithium-ion Batteries at Elevated Temperatures
    Open this publication in new window or tab >>The Role of LiTDI Additive in LiNi1/3Mn1/3Co1/3O2/graphite Lithium-ion Batteries at Elevated Temperatures
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-320188 (URN)
    Available from: 2017-04-17 Created: 2017-04-17 Last updated: 2017-04-26
    3. Improved Performance of the Silicon Anode for Li-Ion Batteries: Understanding the Surface Modification Mechanism of Fluoroethylene Carbonate as an Effective Electrolyte Additive
    Open this publication in new window or tab >>Improved Performance of the Silicon Anode for Li-Ion Batteries: Understanding the Surface Modification Mechanism of Fluoroethylene Carbonate as an Effective Electrolyte Additive
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    2015 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 7, 2591-2599 p.Article in journal (Refereed) Published
    Abstract [en]

    Silicon as a negative electrode material for lithium-ion batteries has attracted tremendous attention due to its high theoretical capacity, and fluoroethylene carbonate (FEC) was used as an electrolyte additive, which significantly improved the cyclability of silicon-based electrodes in this study. The decomposition of the FEC additive was investigated by synchrotron-based X-ray photoelectron spectroscopy (PES) giving a chemical composition depth-profile. The reduction products of FEC were found to mainly consist of LiF and -CHF-OCO2-type compounds. Moreover, FEC influenced the lithium hexafluorophosphate (LiPF6) decomposition reaction and may have suppressed further salt degradation. The solid electrolyte interphase (SEI) formed from the decomposition of ethylene carbonate (EC) and diethyl carbonate (DEC), without the FEC additive present, covered surface voids and lead to an increase in polarization. However, in the presence of FEC, which degrades at a higher reduction potential than EC and DEC, instantaneously a conformal SEI was formed on the silicon electrode. This stable SEI layer sufficiently limited the emergence of large cracks and preserved the original surface morphology as well as suppressed the additional SEI formation from the other solvent. This study highlights the vital importance of how the chemical composition and morphology of the SEI influence battery performance.

    National Category
    Other Chemistry Topics
    Identifiers
    urn:nbn:se:uu:diva-253257 (URN)10.1021/acs.chemmater.5b00339 (DOI)000353176100041 ()
    Available from: 2015-05-26 Created: 2015-05-25 Last updated: 2017-04-26Bibliographically approved
    4. A hard X-ray photoelectron spectroscopy study on the solid electrolyte interphase of a lithium 4,5-dicyano-2- (trifluoromethyl)imidazolide based electrolyte for Si-electrodes
    Open this publication in new window or tab >>A hard X-ray photoelectron spectroscopy study on the solid electrolyte interphase of a lithium 4,5-dicyano-2- (trifluoromethyl)imidazolide based electrolyte for Si-electrodes
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    2016 (English)In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 301, 105-112 p.Article in journal (Other academic) Published
    Abstract [en]

    This report focuses on the relatively new salt, lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI), and its functionality together with a silicon based composite electrode in a half-cell lithium ion battery context. LiTDI is a promising alternative to the commonly used LiPF6 salt because it does not form HF which can decompose the oxide layer on Si. The formation of a solid electrolyte interphase (SEI) as well as the development of the active Si-particles are investigated during the first electrochemical lithiation and de-lithiation. Characterizations are carried out at different state of charge with scanning electron microscopy (SEM) as well as hard x-ray photoelectron spectroscopy (HAXPES) at two different photon energies. This enables a depth resolved picture of the reaction processes and gives an idea of the chemical buildup of the SEI. The SEI is formed by solvent and LiTDI decomposition products and its composition is similar to SEI formed by other carbonate based electrolytes. The LiTDI salt or its decomposition products are not in itself reactive towards the active Si-material and no unwanted side reactions occurs with the active Si-particles. Despite some decomposition of the LiTDI salt, it is a promising alternative for electrolytes aimed towards Si-based electrodes.

    Keyword
    Lithium 4, 5-dicyano-2-(trifluoromethyl); imidazolide; Silicon negative electrode; Solid electrolyte interphase; Hard x-ray photoelectron spectroscopy
    National Category
    Natural Sciences Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-261159 (URN)10.1016/j.jpowsour.2015.09.112 (DOI)000365060500014 ()
    Funder
    VINNOVA, P37446-1EU, FP7, Seventh Framework ProgrammeEU, FP7, Seventh Framework ProgrammeEU, FP7, Seventh Framework Programme
    Available from: 2015-08-31 Created: 2015-08-31 Last updated: 2017-04-26Bibliographically approved
    5. SEI Formation and Interfacial Stability of a Si Electrode in a LiTDI-Salt Based Electrolyte with FEC and VC Additives for Li-Ion Batteries
    Open this publication in new window or tab >>SEI Formation and Interfacial Stability of a Si Electrode in a LiTDI-Salt Based Electrolyte with FEC and VC Additives for Li-Ion Batteries
    Show others...
    2016 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 24, 15758-15766 p.Article in journal (Refereed) Published
    Abstract [en]

    An electrolyte based on the new salt, lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI), is evaluated in combination with nano-Si composite electrodes for potential use in Li-ion batteries. The additives fluoroethylene carbonate (FEC) and vinylene carbonate (VC) are also added to the electrolyte to enable an efficient SEI formation. By employing hard X-ray photoelectron spectroscopy (HAXPES), the SEI formation and the development of the active material is probed during the first 100 cycles. With this electrolyte formulation, the Si electrode can cycle at 1200 mAh g(-1) for more than 100 cycles at a coulombic efficiency of 99%. With extended cycling, a decrease in Si particle size is observed as well as an increase in silicon oxide amount. As opposed to LiPF6 based electrolytes, this electrolyte or its decomposition products has no side reactions with the active Si material. The present results further acknowledge the positive effects of SEI forming additives. It is suggested that polycarbonates and a high LiF content are favorable components in the SEI over other kinds of carbonates formed by ethylene carbonate (EC) and dimethyl carbonate (DMC) decomposition. This work thus confirms that LiTDI in combination with the investigated additives is a promising salt for Si electrodes in future Li-ion batteries.

    Keyword
    lithium 4, 5-dicyano-2-(trifluoromethyl)imidazolide, fluoroethylene carbonate, vinylene carbonate, silicon negative electrode, solid electrolyte interphase, hard X-ray photoelectron spectroscopy
    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-299892 (URN)10.1021/acsami.6b02650 (DOI)000378584800099 ()27220376 (PubMedID)
    Funder
    VINNOVAEU, European Research Council, 312284
    Note

    Kan vara artikeln från manuskriptet http://uu.diva-portal.org/smash/record.jsf?pid=diva2:915177

    Available from: 2016-07-29 Created: 2016-07-29 Last updated: 2017-04-26Bibliographically approved
  • Klockare, Isabelle
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    ”Vi lär oss ingenting på dagis, det är vi som lär dem”: En studie kring de äldre förskolebarnens perspektiv på åldersblandade barngrupper2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I dagens samhälle ser ålderssammansättningen av förskolans barngrupper olika ut. I denna studie behandlas fem och sexåringars perspektiv på åldersblandade barngrupper. Syftet är att få en förståelse för hur de äldre barnen kan uppleva att gå tillsammans med de yngre och även om de anser att det påverkar deras lärande inom olika områden. Den valda metoden för att besvara detta är kvalitativ barnintervju. Det har genomförts fyra intervjuer med barn som är fem till sex år gamla. Barnen gick på fyra olika förskoleavdelningar. De teoretiska utgångspunkterna för studien är samläran och den närmsta utvecklinszonen.

    Tidigare relevant forskning kring området har presenterats och använts tillsammans med de teoretiska utgångspunkterna som underlag i förberedelser, genomförande och efterarbete av intervjuer. Resultatet visar att de äldre barnen både har positiva och negativa erfarenheter kring att gå i en åldersblandad barngrupp. De äldre har stor förståelse för de yngre barnens omvårdnadsbehov och hjälper gärna till för att de ska ha det bra. Närkontakt och att vara de yngre barnens hjälpande hand upplevs som positivt. I de äldre barnens värld upplevs de yngre även som jobbiga. De slåss, skriker, stör deras lek och kommunikationen är svår. Utifrån barnintervjuerna går det att dra slutsatsen att de äldre barnen inte upplever att de yngre barnen bidrar till deras lärande och utveckling, men de påverkar heller inte deras verksamhet negativt.

  • Hedblom, Emma
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Limani Palmqvist, Frida
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Konflikthantering i förskolan: En kvalitativ intervjustudie om pedagogens syn på konflikthantering2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • Andersson, Veronica
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Öling, Maria
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Miljöns betydelse för barns lek2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of our study is to examine preschoolteachers ' views on the aspects that is important in the creation of the educational indoor environment related to children’s play. We also want to investigate the offers that can be distinguished in preschoolteachers ' views on children's play in the indoor environment. In order to achieve the purpose of the study and questions of the study, we have conducted interviews with six professional pre-school teachers. The preschool teacher whom we interviewed have different lengths of time and experience in the profession and are operating in two different municipalities in central Sweden. We have been using a qualitative research method and semi-structured interviews. In our study, we assume an environmental psychological approach using affordance-the concept, as the central theoretical starting point.  The results of the study indicates that preschool teachers believe that play is important for the child and that they, in different ways, have created environments to enable and encourage children's play. The results reveal that the environments of the wards are created in different ways to, among other things, reduce running and direct children toward desired actions in the educational indoor environment.

  • Larsson, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Vestberg, Johanna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Barnlitteratur i förskolan: Sex förskollärares arbete med barnlitteratur2017Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vårt syfte med denna kvalitativa intervjustudie är att undersöka sex stycken förskollärares förhållningssätt till ett språkfrämjande arbete kring litteratur i förskoleverksamheter. Metoden vi valt är ostrukturerade intervjuer med sex verksamma förskollärare på fyra olika förskolor. Vår teoretiska utgångspunkt har varit Vygotskijs sociokulturella perspektiv där barnen lär i samspel med både förskollärare och andra barn i en språkfrämjande miljö i förskolan. Resultatet av vår studie visar att förskollärare strävar efter ett språkfrämjande förhållningssätt där litteraturen har en betydelsefull roll i barnens språkutveckling. Slutsatsen av studien är att förskollärarna ser många möjligheter kring arbetet med barnlitteratur i samspel med barnen. 

  • Krantz, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Linevid, Martina
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Delaktighet och samspel i dagens förskola2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • Jonasson, Camilla
    et al.
    Nymoen, Stina
    Lärplattan i förskolan: - en kvalitativ studie om hur fyra förskollärare utformar sin undervisning med lärplattor i barngrupp2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Digitaliseringen av förskolan är ett faktum och läroplanen för förskolan är under förändring. Denna förändring kräver ökad kompetensutveckling för förskollärare eftersom ansvaret vilar hos dem att förse de stora barngrupperna med kunskap som de har rätt till. Ett sätt för huvudmannen att förse förskollärarna med kompetensutveckling är via IKT-grupper.Syftet med grupperna är att deltagarna ska inspireras och ta del av varandras arbete med digitala verktyg i förskolan. Syftet med vår undersökning är att belysa hur förskolläraren tar del av information om hur lärplattan kan användas som ett verktyg i verksamheten. Samtidigt syftar vår undersökning till att undersöka hur förskolläraren tillämpar lärplattan tillsammans med förskolebarn i den planerade aktiviteten. Studien grundas på observationer av planerade aktiviteter samt intervjuer med förskollärare från fyra förskolor i två kommuner i Mellansverige.Vårt resultat visar att förskollärare använder lärplattor i kombination med andra digitala verktyg för att engagera och göra fler barn delaktiga i de gemensamma lärprocesserna. Vidare visar vår forskning en indikation på att sociala medier är förskollärares primära inspirationskälla till utvecklandet av IKT-undervisningen och lärmiljön i förskolan.

  • Paulsson, Emma
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Government.
    EU och Kina - En empirisk undersokning om normativ makt och kritik i diplomatiska relationer2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • Public defence: 2017-06-14 13:00 B/B42, Uppsala
    Ebai, Tonge
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools.
    Development of Enhanced Molecular Diagnostic Tools for Protein Detection and Analysis2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Improved diagnosis, prognosis and disease follow-up is a fundamental procedure and a constant challenge in medicine.  Among the different molecular biomarkers, proteins are the essential regulatory component in blood; hence, by developing enhanced specific and sensitive molecular tools will gives great insight into the different processes in disease treatment.  In this thesis, we build on the proximity ligation assay to develop and apply new adaptable methods to facilitate protein detection.

    In paper I, I present a variant of the proximity ligation assay (we call PLARCA) using micro titer plate for detection and quantification of protein using optical density as readout in the fluorometer. PLARCA detected femtomolar levels of these proteins in patient samples, which was considerably below the detection threshold for ELISA.

    In paper II, we developed and adapted a new method into the in situ PLA methods for detection and identification of extracellular vesicles (EVs) using flow cytometry as readout (a method we call ExoPLA).  We identified five target proteins on the surface of the Evs and using three colors, we identified the EV using flow cytometer.

    In paper III, we aim to improve the efficiency of in situ PLA by creating and developing new designs and versions of the assay we called Unfold probes Through comparison of detection of protein using in situ PLA versus Unfold probes, we observed considerable decrease in non-specific signals, and also a lower detection threshold.

    In paper IV, we describe the development of a solid phase proximity extension (sp-PEA) assay for protein detection and quantification. We compared detection of IL-8, TNF-alpha, IL-10 and IL-6 using spPEA and PEA; spPEA demonstrations over 2 orders of magnitudes in the lower detection concentrations by decreased in background noise.

    List of papers
    1. Sensitive protein detection in microtiter plates by proximity ligation with rolling circle amplification (PLARCA)
    Open this publication in new window or tab >>Sensitive protein detection in microtiter plates by proximity ligation with rolling circle amplification (PLARCA)
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    (English)Manuscript (preprint) (Other academic)
    Keyword
    Enzyme-linked immunosorbent assay, immunoassay and rolling circle amplification
    National Category
    Medical Biotechnology
    Identifiers
    urn:nbn:se:uu:diva-320376 (URN)
    Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2017-05-02
    2. Detecting individual extracellular vesicles using a multicolor in situ proximity ligation assay with flow cytometric readout
    Open this publication in new window or tab >>Detecting individual extracellular vesicles using a multicolor in situ proximity ligation assay with flow cytometric readout
    Show others...
    2016 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, 34358Article in journal (Refereed) Published
    Abstract [en]

    Flow cytometry is a powerful method for quantitative and qualitative analysis of individual cells. However, flow cytometric analysis of extracellular vesicles (EVs), and the proteins present on their surfaces has been hampered by the small size of the EVs - in particular for the smallest EVs, which can be as little as 40 nm in diameter, the limited number of antigens present, and their low refractive index. We addressed these limitations for detection and characterization of EV by flow cytometry through the use of multiplex and multicolor in situ proximity ligation assays (in situ PLA), allowing each detected EV to be easily recorded over background noise using a conventional flow cytometer. By targeting sets of proteins on the surface that are specific for distinct classes of EVs, the method allows for selective recognition of populations of EVs in samples containing more than one type of EVs. The method presented herein opens up for analyses of EVs using flow cytometry for their characterization and quantification.

    National Category
    Cell and Molecular Biology
    Identifiers
    urn:nbn:se:uu:diva-306259 (URN)10.1038/srep34358 (DOI)000384185900001 ()27681459 (PubMedID)
    Funder
    EU, European Research Council, 259796; 294409Swedish Research Council
    Available from: 2016-10-26 Created: 2016-10-26 Last updated: 2017-04-25Bibliographically approved
    3. Enhanced in situ proximity ligation assays via Unfolding PLA probes
    Open this publication in new window or tab >>Enhanced in situ proximity ligation assays via Unfolding PLA probes
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
    Identifiers
    urn:nbn:se:uu:diva-248874 (URN)
    Funder
    Swedish Foundation for Strategic Research EU, FP7, Seventh Framework Programme, 278568EU, FP7, Seventh Framework Programme, 264737
    Available from: 2015-04-08 Created: 2015-04-08 Last updated: 2017-05-04
    4. Protein detection by sensitive magnetic bead-based proximity extension assays
    Open this publication in new window or tab >>Protein detection by sensitive magnetic bead-based proximity extension assays
    (English)Manuscript (preprint) (Other academic)
    Keyword
    protein detection, magnetic bead, sensitivity and detection limits
    National Category
    Medical Biotechnology
    Identifiers
    urn:nbn:se:uu:diva-320377 (URN)
    Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2017-05-04
  • Public defence: 2017-06-13 10:15 Room 2446, Uppsala
    Wang, Siyang
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing.
    Finite Difference and Discontinuous Galerkin Methods for Wave Equations2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wave propagation problems can be modeled by partial differential equations. In this thesis, we study wave propagation in fluids and in solids, modeled by the acoustic wave equation and the elastic wave equation, respectively. In real-world applications, waves often propagate in heterogeneous media with complex geometries, which makes it impossible to derive exact solutions to the governing equations. Alternatively, we seek approximated solutions by constructing numerical methods and implementing on modern computers. An efficient numerical method produces accurate approximations at low computational cost.

    There are many choices of numerical methods for solving partial differential equations. Which method is more efficient than the others depends on the particular problem we consider. In this thesis, we study two numerical methods: the finite difference method and the discontinuous Galerkin method. The finite difference method is conceptually simple and easy to implement, but has difficulties in handling complex geometries of the computational domain. We construct high order finite difference methods for wave propagation in heterogeneous media with complex geometries. In addition, we derive error estimates to a class of finite difference operators applied to the acoustic wave equation. The discontinuous Galerkin method is flexible with complex geometries. Moreover, the discontinuous nature between elements makes the method suitable for multiphysics problems. We use an energy based discontinuous Galerkin method to solve a coupled acoustic-elastic problem.

    List of papers
    1. High order finite difference methods for the wave equation with non-conforming grid interfaces
    Open this publication in new window or tab >>High order finite difference methods for the wave equation with non-conforming grid interfaces
    2016 (English)In: Journal of Scientific Computing, ISSN 0885-7474, E-ISSN 1573-7691, Vol. 68, 1002-1028 p.Article in journal (Refereed) Published
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-264754 (URN)10.1007/s10915-016-0165-1 (DOI)000380693700006 ()
    External cooperation:
    Available from: 2016-01-27 Created: 2015-10-16 Last updated: 2017-04-23Bibliographically approved
    2. An improved high order finite difference method for non-conforming grid interfaces for the wave equation
    Open this publication in new window or tab >>An improved high order finite difference method for non-conforming grid interfaces for the wave equation
    (English)Article in journal (Other academic) Submitted
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-320600 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-04-23
    3. Convergence of summation-by-parts finite difference methods for the wave equation
    Open this publication in new window or tab >>Convergence of summation-by-parts finite difference methods for the wave equation
    2017 (English)In: Journal of Scientific Computing, ISSN 0885-7474, E-ISSN 1573-7691, Vol. 71, 219-245 p.Article in journal (Refereed) Published
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-264752 (URN)10.1007/s10915-016-0297-3 (DOI)000398062500009 ()
    Available from: 2016-09-27 Created: 2015-10-16 Last updated: 2017-05-17Bibliographically approved
    4. Convergence of finite difference methods for the wave equation in two space dimensions
    Open this publication in new window or tab >>Convergence of finite difference methods for the wave equation in two space dimensions
    (English)Article in journal (Other academic) Submitted
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-320603 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-04-23
    5. An energy based discontinuous Galerkin method for acoustic-elastic waves
    Open this publication in new window or tab >>An energy based discontinuous Galerkin method for acoustic-elastic waves
    (English)Manuscript (preprint) (Other academic)
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-320601 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-04-23
  • Arta, Behzad
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Vikten av socialt stöd för ensamkommande barn i relationen till gode mannen: Intervjustudie2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It is increasingly common for unaccompanied minors to seek asylum as political refugees. The most crucial factors for unaccompanied minors are the time they arrive in Sweden and the manner in which they are received. As one of the people they meet on arrival, their legal guardian is both important and appreciated by unaccompanied children. The purpose of this study has been to gain a deeper understanding of what unaccompanied minors consider to be significant in relation to the legal guardian during the asylum process. Data were collected through nine semi-structured interviews of unaccompanied minors. Data were collected through nine semi-structured interviews. These data were analyzed by qualitative content analysis. The results show that a good relationship with the legal guardian is significant for unaccompanied minors. The study found that participants wanted a legal guardian to be available, and for the legal guardian to see the mission as a relationship, to be informal, and to serve as a substitute for a parent/parents. It also emerged that emotional support is important for unaccompanied minors. The conclusion of the interview-based study was that the legal guardian was an important person in the unaccompanied minors’ lives during the asylum process. Besides receiving practical aid, the children asked for emotional support and expected that their legal guardian would be more like a friend or parent.

  • Andersson, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    Robertsson, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    Intelligent Transportation Systems: Capturing the socio-economic value of uncertain and flexible investments2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this study is to evaluate an alternative socio-economical valuation method (i.e., Hybrid Real Options, HRO) to the traditional benefit cost method (CBA) for the evaluation of investments within Intelligent Transportation Systems (ITS). The proposed alternative method will be evaluated by the use of a case study where it is applied and compared to the results of the traditional method. The case study evaluates the socio-economical effects of an investment in Variable Speed Limits along a section of the motorway E18. The results of the study shows that the choice of evaluation methods affects both the investment strategy and the estimated socio-economical benefits of the investment. Using the HRO method yields twice as high socio-economical benefits compared to the CBA method. The main reason for this being that HRO account for risk and uncertainties wheras CBA only accounts for the most probable outcome of the investment. The choice of method is a complex task that involves many stakeholders however a more critical approach to the choice of socio-economical evaluation method is advocated based on the results of this study.

  • Public defence: 2017-06-13 13:30 Ång/4001, Uppsala
    Huang, Wen
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Hydrogen in nano-sized metals: Diffusion and hysteresis effects2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Metal hydrides can be used as hydrogen storage materials for fuel cells and batteries, and as sensors for detecting hydrogen gas. The use of metal hydrides for hydrogen storage can be hindered by poor kinetics and low capacity. Moreover, poor sensitivity, long recovery and response time, limit the applications of metal hydrides as hydrogen sensors. Diffusion is an important factor affecting the hydrogen kinetics and response time. Hysteresis effects accompany the phase transition of hydrogen in metals and can influence the properties of metal hydrides as well. These need to be considered in their applications as storage materials or sensors.

    This thesis concerns the possibility of tuning hydrogen diffusion and studies the mechanism of hysteresis effects of hydrogen absorption in metals. In these experiments, nano-sized vanadium is used as the model system for these studies. Hydrogen concentration is determined by the light transmission. By measuring the concentration profiles and isotherms of hydrogen, it is possible to determine the diffusion coefficients and hysteresis effects.

    A profound decrease of hydrogen diffusion in Fe/V(001) superlattice has been found, as compared to that in bulk vanadium. This result is interpreted as lower zero-point energy in octahedral site than that in tetrahedral site. Profound isotope effect on diffusion has also been found. Influence of clamping of the substrate on the diffusion of hydrogen with concentration in vanadium thin film is discovered. The diffusion coefficient below c = 0.1 [H/V] is close to that in bulk vanadium and decreases substantially when c > 0.1 [H/V] compared with that in bulk vanadium. This finding is interpreted as the site change from tetrahedral to octahedral occupancy when the hydrogen concentration increases. Large finite size effect on deuterium chemical diffusion is observed, which is concluded to be caused by D-D interaction change that will influence the deuterium chemical diffusion at different thickness of vanadium layers. However, finite size has no effect on hydrogen transport at extremely low hydrogen concentrations in Fe/V (001) superlattices, this illustrates that the interface can not influence the mean free path of hydrogen in any way. This is completely different from electron transport condition in nano-sized metals. Hysteresis effect is observed below critical temperature in Fe/V(001) superlattices; this occurrence confirms the hypothesis that hysteresis effect is caused by coherency strain in coherent  transformation.

    List of papers
    1. The influence of site occupancy on diffusion of hydrogen in vanadium
    Open this publication in new window or tab >>The influence of site occupancy on diffusion of hydrogen in vanadium
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    2017 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 95, no 6, 064310Article, review/survey (Refereed) Published
    Abstract [en]

    We investigate the effect of site occupancy on the chemical diffusion of hydrogen in strained vanadium. The diffusion rate is found to decrease substantially, when hydrogen is occupying octahedral sites as compared to tetrahedral sites. Profound isotope effects are observed when comparing the diffusion rate of H and D. The changes in the diffusion rate are found to be strongly influenced by the changes in the potential energy landscape, as deduced from first-principles molecular dynamics calculations.

    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-275058 (URN)10.1103/PhysRevB.95.064310 (DOI)000395988800002 ()
    Note

    The manuscript version of this article is part of two PhD theses: http://uu.diva-portal.org/smash/record.jsf?pid=diva2:900624

    http://uu.diva-portal.org/smash/record.jsf?pid=diva2:950756

    Available from: 2016-01-28 Created: 2016-01-28 Last updated: 2017-05-03Bibliographically approved
    2. Concentration dependence of hydrogen diffusion in clamped vanadium (001) films
    Open this publication in new window or tab >>Concentration dependence of hydrogen diffusion in clamped vanadium (001) films
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    2017 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 29, no 4, 045402Article in journal (Refereed) Published
    Abstract [en]

    The chemical diffusion coefficient of hydrogen in a 50 nm thin film of vanadium (0 0 1) is measured as a function of concentration and temperature, well above the known phase boundaries. Arrhenius analysis of the tracer diffusion constants reveal large changes in the activation energy with concentration: from 0.10 at 0.05 in II V-1 to 0.5 eV at 0.2 in II V-1. The results are consistent with a change from tetrahedral to octahedral site occupancy, in that concentration range. The change in site occupancy is argued to be caused by the uniaxial expansion of the film originating from the combined hydrogen induced expansion and the clamping of the film to the substrate.

    Keyword
    diffusion, hydrogen, single crystal
    National Category
    Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-312024 (URN)10.1088/1361-648X/29/4/045402 (DOI)000389233200001 ()
    Funder
    Swedish Energy AgencySwedish Research Council
    Available from: 2017-01-05 Created: 2017-01-04 Last updated: 2017-05-03Bibliographically approved
    3. Diffusion of hydrogen in ultra-thin V(001) layers
    Open this publication in new window or tab >>Diffusion of hydrogen in ultra-thin V(001) layers
    Show others...
    (English)Article in journal (Other academic) Submitted
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-320733 (URN)
    Available from: 2017-04-24 Created: 2017-04-24 Last updated: 2017-05-03
    4. Finite size effects as a tool to accelerate diffusion of light interstitials
    Open this publication in new window or tab >>Finite size effects as a tool to accelerate diffusion of light interstitials
    Show others...
    (English)Article in journal (Other academic) Submitted
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-320562 (URN)
    Available from: 2017-04-21 Created: 2017-04-21 Last updated: 2017-05-03
    5. Experimental realization of hysteresis in a coherent phase transition
    Open this publication in new window or tab >>Experimental realization of hysteresis in a coherent phase transition
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-320734 (URN)
    Available from: 2017-04-24 Created: 2017-04-24 Last updated: 2017-05-03
  • Public defence: 2017-06-12 09:00 A1:111a, Uppsala
    Torabi Moghadam, Behrooz
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Computational discovery of DNA methylation patterns as biomarkers of ageing, cancer, and mental disorders: Algorithms and Tools2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Epigenetics refers to the mitotically heritable modifications in gene expression without a change in the genetic code. A combination of molecular, chemical and environmental factors constituting the epigenome is involved, together with the genome, in setting up the unique functionality of each cell type.

    DNA methylation is the most studied epigenetic mark in mammals, where a methyl group is added to the cytosine in a cytosine-phosphate-guanine dinucleotides or a CpG site. It has been shown to have a major role in various biological phenomena such as chromosome X inactivation, regulation of gene expression, cell differentiation, genomic imprinting. Furthermore, aberrant patterns of DNA methylation have been observed in various diseases including cancer.

    In this thesis, we have utilized machine learning methods and developed new methods and tools to analyze DNA methylation patterns as a biomarker of ageing, cancer subtyping and mental disorders.

    In Paper I, we introduced a pipeline of Monte Carlo Feature Selection and rule-base modeling using ROSETTA in order to identify combinations of CpG sites that classify samples in different age intervals based on the DNA methylation levels. The combination of genes that showed up to be acting together, motivated us to develop an interactive pathway browser, named PiiL, to check the methylation status of multiple genes in a pathway. The tool enhances detecting differential patterns of DNA methylation and/or gene expression by quickly assessing large data sets.

    In Paper III, we developed a novel unsupervised clustering method, methylSaguaro, for analyzing various types of cancers, to detect cancer subtypes based on their DNA methylation patterns. Using this method we confirmed the previously reported findings that challenge the histological grouping of the patients, and proposed new subtypes based on DNA methylation patterns. In Paper IV, we investigated the DNA methylation patterns in a cohort of schizophrenic and healthy samples, using all the methods that were introduced and developed in the first three papers.

    List of papers
    1. Combinatorial identification of DNA methylation patterns over age in the human brain
    Open this publication in new window or tab >>Combinatorial identification of DNA methylation patterns over age in the human brain
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    2016 (English)In: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 17, 393Article in journal (Refereed) Published
    Abstract [en]

    Background: DNA methylation plays a key role in developmental processes, which is reflected in changing methylation patterns at specific CpG sites over the lifetime of an individual. The underlying mechanisms are complex and possibly affect multiple genes or entire pathways. Results: We applied a multivariate approach to identify combinations of CpG sites that undergo modifications when transitioning between developmental stages. Monte Carlo feature selection produced a list of ranked and statistically significant CpG sites, while rule-based models allowed for identifying particular methylation changes in these sites. Our rule-based classifier reports combinations of CpG sites, together with changes in their methylation status in the form of easy-to-read IF-THEN rules, which allows for identification of the genes associated with the underlying sites. Conclusion: We utilized machine learning and statistical methods to discretize decision class (age) values to get a general pattern of methylation changes over the lifespan. The CpG sites present in the significant rules were annotated to genes involved in brain formation, general development, as well as genes linked to cancer and Alzheimer's disease.

    Keyword
    DNA methylation, Aging, Rule-based classification, Feature selection
    National Category
    Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
    Identifiers
    urn:nbn:se:uu:diva-305330 (URN)10.1186/s12859-016-1259-3 (DOI)000383750700001 ()
    Funder
    Swedish Research Council FormaseSSENCE - An eScience Collaboration
    Available from: 2016-10-14 Created: 2016-10-14 Last updated: 2017-05-03Bibliographically approved
    2. PiiL: visualization of DNA methylation and gene expression data in gene pathways
    Open this publication in new window or tab >>PiiL: visualization of DNA methylation and gene expression data in gene pathways
    (English)Article in journal (Refereed) Submitted
    Abstract [en]

    DNA methylation is a major mechanism involved in the epigenetic state of a cell. It has been observed that the methylation status of certain CpG sites close to or within a gene can directly affect its expression, either by silencing or, in some cases, up-regulating transcription. However, a vertebrate genome contains millions of CpG sites, all of which are potential targets for methylation modification, and the specific effects of most sites has not been characterized to date. To study the complex interplay between methylation status, cellular programs, and the resulting phenotypes, we present PiiL, an interactive gene expression pathway browser, facilitating the analysis through an integrated view of methylation and expression on multiple levels.

    PiiL allows for specific hypothesis testing by quickly assessing pathways or gene networks, where the data is projected onto pathways that can be downloaded directly from the online KEGG database. PiiL provides a comprehensive set of analysis features, allowing for quickly searching for specific patterns, as well as to examine individual CpG sites and their impact on expression of the host gene and other genes in regulatory networks. To exemplify the power of this approach, we analyzed two types of brain tumors, Glioblastoma multiform and lower grade gliomas.

    At a glance, we could confirm earlier findings that the predominant methylation and expression patterns separate perfectly by mutations in the IDH genes, rather than by histology. We could also infer the IDH mutation status for samples for which the genotype was not known. By applying different filtering methods, we show that a subset of CpG sites exhibits consistent methylation patterns, and that the status of sites affect the expression of key regulator genes, as well as other genes located downstream in the same pathways.

    PiiL is implemented in Java with focus on a user-friendly graphical interface. The source code is available under the GPL license from https://github.com/behroozt/PiiL.git.

    Keyword
    DNA methylation, gene expression, KEGG pathways, visualization
    National Category
    Bioinformatics (Computational Biology)
    Identifiers
    urn:nbn:se:uu:diva-320675 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-04-24
    3. An unsupervised approach subgroups cancer types by distinct local DNA methylation patterns
    Open this publication in new window or tab >>An unsupervised approach subgroups cancer types by distinct local DNA methylation patterns
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    (English)Article in journal (Other academic) Submitted
    Abstract [en]

    Cancer is one of the most common causes of death in humans. It can arise from many different cell types, and even cancers originating from the same tissue can constitute a heterogeneous group of diseases. While cytogenetics, the analysis of mutations and karyotypic alterations, has greatly improved the accuracy of diagnosis, it is likely that there are more categories in which cancers can be divided than is known today. Moreover, new biomarkers confirming existing classification schemes are desirable. Here, we interrogated the DNA methylation (DNAm) landscape as a novel indicator for discerning cancer subtypes.

    We developed and applied an unsupervised method, methylSaguaro, which is based on the combination of a Hidden Markov Model and a Neural Net. We first compared the concept of hypothesizing patterns and grouping to statistical methods that require a priori hypotheses to perform enrichment tests. We then analyzed samples from four cancer groups, Gliomas, Chronic Lymphocytic Leukemia (CLL), Renal Cell Carcinomas (RCC), and Acute Myeloid Leukemia (AML). On gliomas and CLL, we confirmed known cancer groupings in DNAm that perfectly correspond to known mutations. On Renal Cell Carcinomas, our method disagrees with the histological classification on 4% of the samples, and finds a novel cluster, suggesting that there might be a novel subtype that was hitherto unknown. On AML, methylSaguaro spreads the samples out on a continuous spectrum, enriching one end with patients assessed as having “poor” risk based on cytogenetics, but indicating that DNAm patterns would suggest a different risk assessment. Since methylSaguaro reports both the patterns and the specific sites behind the signals, we analyzed regions and genes indicative of subtypes across the cancers, revealing 41 genes affected by alterations in more than one cancer. In summary, we expect that DNAm, coupled with a hypothesis-free analysis method, will add to the set of clinical instruments to diagnose, assess, and treat cancer.

    Keyword
    unsupervised learning, DNA methylation, cancer subtyping
    National Category
    Bioinformatics (Computational Biology)
    Identifiers
    urn:nbn:se:uu:diva-320676 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-04-24
    4. Analyzing DNA methylation patterns in Schizophrenic patients using machine learning methods
    Open this publication in new window or tab >>Analyzing DNA methylation patterns in Schizophrenic patients using machine learning methods
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    (English)Article in journal (Other academic) Submitted
    Abstract [en]

    Schizophrenia is common mental disorder with known genetic component involved. Since the association of environmental factors and schizophrenia has been reported, we analyzed a cohort of 75 schizophrenic and 50 control samples to investigate DNA methylation patterns, as one of the key players of epigenetic gene regulation.

    Here we applied machine-learning and visualization methods, which were shown previously to be successful in detecting and highlighting differentially methylated patterns between cases and controls. On this data set, however, these methods did not uncover any signal discerning schizophrenia patients and healthy controls, suggesting that if a link exists, it is heterogeneous and complex.

    National Category
    Bioinformatics (Computational Biology)
    Identifiers
    urn:nbn:se:uu:diva-320678 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-05-02
  • Tegenu, Tsegaye
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Social and Economic Geography.
    Youth Bulge in Cities and Towns, its Remedies2017Other (Other (popular science, discussion, etc.))
  • Tegenu, Tsegaye
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Social and Economic Geography.
    100 Million People Economic System in Ethiopia2017Other (Other (popular science, discussion, etc.))
  • Public defence: 2017-06-09 09:15 Rosénsalen, Uppsala
    Gunnarsdóttir, Jóhanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Obstetrics and Gynaecology.
    Epidemiological Studies of Preeclampsia: Maternal & Offspring Perspectives 2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Preeclampsia is a placental-related disorder characterized by generalized endothelial activation. Vascular predisposition is associated with the occurrence of preeclampsia and the recurrence risk is substantial. Onset of preeclampsia is preceded by placental hypo-perfusion, and placental over-production of vasoconstrictive agents might explain symptoms such as hypertension and proteinuria. Preeclampsia is associated with the birth of small-for-gestational-age (SGA) infants. The trajectory of postnatal growth in SGA-born children is described as catch-up, but it is unclear whether prenatal preeclampsia is independently associated with postnatal growth.

    The objectives were: firstly, to study the association between partner change and prior miscarriages on the occurrence of preeclampsia and SGA; secondly, to study postnatal growth in children prenatally exposed to preeclampsia; and thirdly, to address the association between blood pressure (BP) changes during pregnancy and risks of preeclampsia and SGA.

    Population-based cohort studies were performed with information from the following registers: Swedish Medical Birth Register, Uppsala Mother and Child Database and Stockholm-Gotland Obstetric Database. Associations were estimated with logistic and linear regression analyses, with adjustments for maternal characteristics, including body mass index, pre-gestational diseases and socioeconomic factors.

    The results were, firstly, that partner change was associated with preeclampsia and SGA birth in the second pregnancy but depended on the outcome of the first pregnancy, and that a history of recurrent miscarriages was associated with increased risks of preeclampsia and SGA. Secondly, prenatal exposure to preeclampsia was associated with increased offspring growth in height during the first five years. This association was also seen in children born with normal birth weight for gestational age. Thirdly, pre-hypertension in late gestation and elevated diastolic BP from early to mid-gestation were both associated with SGA birth. Further, women with pre-hypertension in early gestation without lowered diastolic BP until mid-gestation seemed to represent a risk group for preeclampsia.

    To conclude, the importance of previous pregnancy outcomes in the antenatal risk evaluation was highlighted. Secondly, the results imply that postnatal growth trajectory is related to maternal preeclampsia, in addition to SGA. Thirdly, the association between BP changes within a normal range and SGA may challenge the clinical cut-off for hypertension in pregnancy.

    List of papers
    1. The paternal role in pre-eclampsia and giving birth to a small for gestational age infant: a population-based cohort study
    Open this publication in new window or tab >>The paternal role in pre-eclampsia and giving birth to a small for gestational age infant: a population-based cohort study
    2012 (English)In: BMJ open, ISSN 2044-6055, Vol. 2, no 4, e001178- p.Article in journal (Refereed) Published
    Abstract [en]

    OBJECTIVE:

    To estimate the effect of partner change on risks of pre-eclampsia and giving birth to a small for gestational age infant.

    DESIGN:

    Prospective population study.

    SETTING:

    Sweden.

    PARTICIPANTS:

    Women with their first and second successive singleton births in Sweden between 1990 and 2006 without pregestational diabetes and/or hypertension (n=446 459).

    OUTCOME MEASURES:

    Preterm (<37 weeks) and term (≥37 weeks) pre-eclampsia, and giving birth to a small for gestational age (SGA) infant. Risks were adjusted for interpregnancy interval, maternal age, body mass index, height and smoking habits in second pregnancy, years of involuntary childlessness before second pregnancy, mother's country of birth, years of formal education and year of birth. Further, when we calculated risks of SGA we restricted the study population to women with non-pre-eclamptic pregnancies.

    RESULTS:

    In women who had a preterm pre-eclampsia in first pregnancy, partner change was associated with a strong protective effect for preterm pre-eclampsia recurrence (OR 0.24; 95% CI 0.07 to 0.88). Similarly, partner change was also associated with a protective effect of recurrence of SGA birth (OR 0.75; 95% CI 0.67 to 0.84). In contrast, among women without SGA in first birth, partner change was associated with an increased risk of SGA in second pregnancy. Risks of term pre-eclampsia were not affected by partner change.

    CONCLUSIONS:

    There is a paternal effect on risks of preterm pre-eclampsia and giving birth to an SGA infant.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-186861 (URN)10.1136/bmjopen-2012-001178 (DOI)000315049300065 ()22936817 (PubMedID)
    Available from: 2012-11-29 Created: 2012-11-29 Last updated: 2017-04-21Bibliographically approved
    2. Risk of placental dysfunction disorders after prior miscarriages: a population-based study
    Open this publication in new window or tab >>Risk of placental dysfunction disorders after prior miscarriages: a population-based study
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    2014 (English)In: American Journal of Obstetrics and Gynecology, ISSN 0002-9378, E-ISSN 1097-6868, Vol. 211, no 1, 34.e1-34.e8 p.Article in journal (Refereed) Published
    Abstract [en]

    OBJECTIVE: The objective of the investigation was to study the association between prior miscarriages and the risks of placental dysfunction disorders, including preeclampsia, stillbirth, birth of a small for gestational age (SGA) infant, placental abruption, and spontaneous preterm birth. STUDY DESIGN: In a population-based cohort study including 619,587 primiparous women, we estimated risks of placental dysfunction disorders for women with 1 (n = 68,185), 2 (n = 11,410) and 3 or more (n = 3823) self-reported prior miscarriages. Risks were calculated as odds ratios by unconditional logistic regression analysis and adjustments were made for maternal age, early pregnancy body mass index, height, smoking habits, country of birth, years of formal education, in vitro fertilization, chronic hypertension, pregestational diabetes, hypothyroidism, systemic lupus erythematosis, fetal sex, and year of childbirth. RESULTS: Compared with women with no prior miscarriage, women with 1 prior miscarriage had almost no increased risks. Women with 2 prior miscarriages had increased risks of spontaneous preterm birth, preterm (<37 weeks) SGA infant, and placental abruption. The rates of all disorders were higher for women with 3 or more prior miscarriages compared with women without prior miscarriages: preeclampsia, 5.83% vs 4.27%; stillbirth, 0.69% vs 0.33%, SGA infant, 5.09% vs 3.22%, placental abruption, 0.81% vs 0.41%; and spontaneous preterm birth, 6.45% vs 4.40%. The adjusted odds ratios for preterm (<37 weeks) disorders in women with 3 prior miscarriages were approximately 2. CONCLUSION: History of 2 or more miscarriages is associated with an increased risk of placental dysfunction disorders and should be regarded as a risk factor in antenatal care.

    Keyword
    intrauterine growth restriction, miscarriage, placental abruption, preeclampsia, spontaneous preterm birth, stillbirth
    National Category
    Obstetrics, Gynecology and Reproductive Medicine
    Identifiers
    urn:nbn:se:uu:diva-231320 (URN)10.1016/j.ajog.2014.01.041 (DOI)000339747000013 ()24495667 (PubMedID)
    Available from: 2014-09-08 Created: 2014-09-07 Last updated: 2017-04-21Bibliographically approved
    3. Prenatal exposure to preeclampsia is associated with accelerated height gain in early childhood
    Open this publication in new window or tab >>Prenatal exposure to preeclampsia is associated with accelerated height gain in early childhood
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    (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203Article in journal (Refereed) Submitted
    National Category
    Obstetrics, Gynecology and Reproductive Medicine
    Identifiers
    urn:nbn:se:uu:diva-320671 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-05-03
    4. Prehypertension in Pregnancy and Risks of Small for Gestational Age Infant and Stillbirth
    Open this publication in new window or tab >>Prehypertension in Pregnancy and Risks of Small for Gestational Age Infant and Stillbirth
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    2016 (English)In: Hypertension, ISSN 0194-911X, E-ISSN 1524-4563, Vol. 67, no 3, 640-646 p.Article in journal (Refereed) Published
    Abstract [en]

    It is not fully known whether maternal prehypertension is associated with increased risk of adverse fetal outcomes, and it is debated whether increases in blood pressure during pregnancy influence adverse fetal outcomes. We performed a population-based cohort study in nonhypertensive women with term (37 weeks) singleton births (n=157446). Using normotensive (diastolic blood pressure [DBP] <80 mmHg) women as reference, we calculated adjusted odds ratios with 95% confidence intervals between prehypertension (DBP 80-89 mmHg) at 36 gestational weeks (late pregnancy) and risks of a small-for-gestational-age (SGA) birth or stillbirth. We further estimated whether an increase in DBP from early to late pregnancy affected these risks. We found that 11% of the study population had prehypertension in late pregnancy. Prehypertension was associated with increased risks of both SGA birth and stillbirth; adjusted odds ratios (95% confidence intervals) were 1.69 (1.51-1.90) and 1.70 (1.16-2.49), respectively. Risks of SGA birth in term pregnancy increased by 2.0% (95% confidence intervals 1.5-2.8) per each mmHg rise in DBP from early to late pregnancy, whereas risk of stillbirth was not affected by rise in DBP during pregnancy. We conclude that prehypertension in late pregnancy is associated with increased risks of SGA birth and stillbirth. Risk of SGA birth was also affected by rise in DBT during pregnancy. Our findings provide new insight to the relationship between maternal blood pressure and fetal well-being and suggest that impaired maternal perfusion of the placenta contribute to SGA birth and stillbirth.

    Keyword
    blood pressure, fetal death, fetal growth retardation, prehypertension, stillbirth
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-280233 (URN)10.1161/HYPERTENSIONAHA.115.06752 (DOI)000369755200028 ()26831196 (PubMedID)
    Funder
    Swedish Research Council, 2014-3561
    Available from: 2016-03-09 Created: 2016-03-09 Last updated: 2017-04-21Bibliographically approved
    5. Elevated diastolic blood pressure until mid-gestation is associated with preeclampsia and small for gestational age.
    Open this publication in new window or tab >>Elevated diastolic blood pressure until mid-gestation is associated with preeclampsia and small for gestational age.
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Obstetrics, Gynecology and Reproductive Medicine
    Identifiers
    urn:nbn:se:uu:diva-320672 (URN)
    Available from: 2017-04-23 Created: 2017-04-23 Last updated: 2017-05-03
  • Public defence: 2017-06-12 13:00 A1:111a, Uppsala
    Holmgren, Benjamin T.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Microbiology.
    Connecting Systemic RNAi to the Endomembrane System in Caenorhabditis elegans2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    RNA interference (RNAi) is a gene regulation mechanism conserved among eukaryotes. To silence gene expression, RNAi relies on a short single-stranded guide RNA to steer the RNA-induced Silencing Complex (RISC) to mRNAs with guide strand-complementary sequences. RNAi is a highly membrane-associated process. The RISC complex is likely loaded at the rough Endoplasmic Reticulum, where it can bind to and degrade mRNAs. Components of the RISC complex also colocalize to late endosomes, and the efficiency of RNAi-mediated silencing is affected by changes in late endosome to lysosome fusion. RNAi can be systemic and inherited, effecting gene silencing in distal tissues and in the offspring.

    In this thesis, the model organism Caenorhabditis elegans was used to identify and characterize factors connecting systemic and inherited RNAi to the endomembrane system. We identify two SNARE proteins, SEC-22 and SYX-6, that both act as negative regulators of RNAi. SNAREs are necessary for vesicle fusion. Both SEC-22 and SYX-6 localize to late endosomes, and both interact with systemic RNAi protein SID-5 in a yeast two-hybrid (Y2H) screen. We find that in addition to its function in systemic RNAi, SID-5 is required for proper maturation of late endosomes. Furthermore, we identify the putative RNA-binding protein C12D8.1 as a novel regulator of RNAi inheritance. Mutant C12D8.1 animals will have enhanced inheritance of RNAi silencing, which negatively affects the ability of the progeny to silence new targets using RNAi. Finally, we describe a novel, object-based method for estimating significance in colocalization studies. This method helped us describe and quantify spatial relations between fluorophore-labeled proteins in situations where such analyses would otherwise be impossible.

    In conclusion, the work presented here further elucidates the connection between cellular RNAi, the endomembrane system, and the outside world.

    List of papers
    1. The conserved SNARE SEC-22 localizes to late endosomes and negatively regulates RNA interference in Caenorhabditis elegans
    Open this publication in new window or tab >>The conserved SNARE SEC-22 localizes to late endosomes and negatively regulates RNA interference in Caenorhabditis elegans
    2017 (English)In: RNA, ISSN 1355-8382, Vol. 23, no 3, 297-307 p.Article in journal (Refereed) Published
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-321388 (URN)10.1261/rna.058438.116 (DOI)
    Available from: 2017-05-04 Created: 2017-05-04 Last updated: 2017-05-04
    2. RNA Transport Protein SID-5 Interacts with Multiple SNAREs and Affects Membrane Trafficking in C. elegans Intestinal Cells
    Open this publication in new window or tab >>RNA Transport Protein SID-5 Interacts with Multiple SNAREs and Affects Membrane Trafficking in C. elegans Intestinal Cells
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-320894 (URN)
    Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2017-04-27
    3. Putative RNA-Binding Protein C12D8.1 Negatively Regulates Inheritance of RNAi in Caenorhabditis elegans
    Open this publication in new window or tab >>Putative RNA-Binding Protein C12D8.1 Negatively Regulates Inheritance of RNAi in Caenorhabditis elegans
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-320895 (URN)
    Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2017-05-03
    4. DESCROD Estimates Significant Colocalization by Randomized Object Displacement
    Open this publication in new window or tab >>DESCROD Estimates Significant Colocalization by Randomized Object Displacement
    (English)Manuscript (preprint) (Other academic)
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-320893 (URN)
    Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2017-04-27
  • Lärkefjord, Gabriel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences.
    Provoking Placebo: A Literature Study About Placebo Response in Nursing2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: The placebo effect and the placebo response is a misunderstood phenomenon and their potential is wildly underestimated. Most people, including health care professionals, consider the placebo effect to be a “make believe” effect which only affects gullible people. It is argued that the nurse is in an unusually advantageous position to observe and facilitate the placebo effect and make use of the benefits for the patients. Observation of said response is made by many authors but there is little to no research on the placebo effect from a nursing standpoint. Some of the research results can however be translated to the nurse profession and used in clinical settings. Aim: The purpose is to describe areas where the placebo effect may affect nursing of the patient. Method: A literature review format was chosen to comprise existing knowledge on the placebo effect, which can be applied for nursing. Results: Themes that arose from examination of chosen literature included: Emotional state, Expectation and Conditioning, Conscious and Social learning and Patient-caregiver relationship. Many of the observed interventions could be applied using the nursing philosophy of Hildegard Peplau. Conclusion: The placebo effect can be used by the nurse to improve the result of the patient´s treatment. If placebo becomes a focus in nursing research the results could be more applicable to benefit patients than if researched by other professional groups.

  • Skoglund, Vilhelm
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Law, Department of Law.
    Granskning av hållbarhetsrapporter: En utredning och utvärdering av nya lagregler2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • Sheikhahmadi, Kajal
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Ahlberg, Sofia
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Flerspråkighet i förskolan: En kvalitativ studie om pedagogens arbete med flerspråkiga barns språkutveckling2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka hur pedagoger arbetar med språkutvecklingen hos flerspråkiga barn i förskolan. Dessutom vill vi skaffa oss kunskap om vilket material som används i arbete med dessa barn vid språkutveckling. Studien baseras på en kvalitativ undersökning och kvalitativa intervjuer används för att kunna besvara på vårt syfte och frågeställningar. Intervjuerna genomfördes med sju pedagoger dvs. fyra förskollärare och tre barnskötare, i två olika kommuner i Stockholms län. Det sammanställda resultatet visar att alla förskolor använder olika verktyg/redskap som exempelvis TAKK (tecken som alternativ och kompletterande kommunikation), böcker på olika språk, sånger och ramsor samt bilder för att tydliggöra det dagliga arbetet för både flerspråkiga barn och barn som inte har kommit så långt i sin språkutveckling. Med hjälp av olika verktyg/redskap underlättar pedagogerna för barnen att kunna kommunicera både med varandra och med de vuxna i förskolan. Vidare visar studien att pedagogernas roll har stor betydelse för arbete med flerspråkiga barns språkutveckling.

  • Thienel, Matthias
    et al.
    Univ Tubingen, Inst Med Psychol & Behav Neurobiol, Otfried Muller Str 25, D-72076 Tubingen, Germany..
    Wilhelm, Ines
    Univ Childrens Hosp Zurich, Child Dev Ctr, Zurich, Switzerland..
    Benedict, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Functional Pharmacology.
    Born, Jan
    Univ Tubingen, Inst Med Psychol & Behav Neurobiol, Otfried Muller Str 25, D-72076 Tubingen, Germany.;German Ctr Diabet Res DZD, Tubingen, Germany.;Univ Tubingen IDM, Helmholtz Ctr Munich, Inst Diabet Res & Metab Dis, Tubingen, Germany..
    Hallschmid, Manfred
    Univ Tubingen, Inst Med Psychol & Behav Neurobiol, Otfried Muller Str 25, D-72076 Tubingen, Germany.;German Ctr Diabet Res DZD, Tubingen, Germany.;Univ Tubingen IDM, Helmholtz Ctr Munich, Inst Diabet Res & Metab Dis, Tubingen, Germany..
    Intranasal insulin decreases circulating cortisol concentrations during early sleep in elderly humans2017In: Neurobiology of Aging, ISSN 0197-4580, E-ISSN 1558-1497, Vol. 54, 170-174 p., 170e174Article in journal (Refereed)
    Abstract [en]

    Aging is associated with increases in hypothalamic-pituitary-adrenal (HPA) axis activity that can predispose to metabolic and cognitive impairments. We investigated in elderly and young subjects whether intranasal insulin administration to the human brain reduces early-sleep nadir concentrations of adrenocorticotropin and cortisol, that is, indicators of baseline HPA axis activity. In within-subject comparisons, intranasal insulin (160 IU) or placebo was administered to 14 elderly (mean age 70.0 years) and 30 young (23.6 years) healthy subjects before bedtime. Sleep was polysomno-graphically assessed and blood samples were repeatedly collected. Elderly compared with young participants displayed increased early-sleep cortisol concentrations (p < 0.04) and reductions in slow wave and REM sleep (p < 0.001). Insulin administration reduced cortisol levels between 2300 hours and 0020 hours in the elderly (p = 0.03) but not young participants (p = 0.56; p = 0.003 for interaction). Findings indicate that central nervous insulin acts as an inhibitory signal in basal HPA axis activity regulation and suggest that intranasal insulin may normalize sleep-associated stress axis activity in older age.

  • Public defence: 2017-06-09 10:00 Geijersalen (Eng6-1023), Uppsala
    Rydberg, Andreas
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of History of Science and Ideas.
    Inner Experience: An Analysis of Scientific Experience in Early Modern Germany2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In the last decades a number of studies have shed light on early modern scientific experience. While some of these studies have focused on how new facts were forced out of nature in so-called experimental situations, others have charted long-term transformations. In this dissertation I explore a rather different facet of scientific experience by focusing on the case of the Prussian university town Halle in the period from the late seventeenth till the mid-eighteenth century. At this site philosophers, theologians and physicians were preoccupied with categories such as inner senses, inner experience, living experience, psychological experiments and psychometrics. In the study I argue that these hitherto almost completely overlooked categories take us away from observations of external things to the internal organisation of experience and to entirely internal objects of experience. Rather than seeing this internal side of scientific experience as mere theory and epistemology, I argue that it was an integral and central part of what has been referred to as the cultura animi tradition, that is, the philosophical and medical tradition of approaching the soul as something in need of cultivation, education, disciplination and cure.

    The study contains four empirical chapters. In the first chapter I analyse the meaning and function of experience in Christian Wolff’s philosophy understood as spiritual exercise and cultura animi. In the second chapter I examine experience in the theologian Hermann Francke’s cultura animi, focusing particularly on the relation between scientific experience and what scholars have referred to as religious experience. In the third chapter I chart aesthetic experience in Alexander Baumgarten’s aesthetics. In the fourth chapter I examine the role of experience in the medicine of Georg Ernst Stahl, Friedrich Hoffmann and their followers. The analysis of medical experience channels the discussion into questions regarding the relation between the cultura animi tradition and the kind of attitudes, practices and processes that have been connected to modern objectivity.

     

  • Public defence: 2017-06-07 10:15 Hörsal 2, Uppsala
    Murzabekov, Marat
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Social and Economic Geography.
    Political Pasture: A Governmentality Analysis of Community-Based Pasture Management in Kyrgyzstan2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis seeks to understand the development and implementation of the community-based pasture management policy in Kyrgyzstan, which transferred the responsibility for pasture-use planning from state administrative organs to local community-based organizations.

    Using document analysis, this thesis contextualizes the emergence and evolution of the policy’s key premises, including the advantages of community-based management compared to state-centered management. Using interviews and observations, this thesis draws out individual experiences of herders, forestry service officials and the members of pasture committees with the implementation of the policy in the Kadamzhai district of Kyrgyzstan.

    Findings suggest that historical continuities in pasture governance play an important role in the functioning of such policies. On the national level, the reliance of the state on the Soviet administrative and territorial division has reinforced pasture-use fragmentation, where different institutional actors struggle for authority over pastures. These struggles can be observed on the local level, where the implementation of policy is often challenged by forestry officials believing in the advantages of the Soviet fortress conservation, rather than community-based management.

    Second, the local outcomes of policy depend on the compliant or resistant subject positions of individuals involved in pasture use. Policy implementation succeeded in the recruitment of compliant pasture committee chairmen, who claim to be interested in bringing good to the communities through steering the use of pastures. However, the procedures for the establishment of committees contributed to their top-down functioning, where herders often consider the committees as a state agency and find different strategies to avoid their imposed payments.

  • Frank, Jacob
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Law, Department of Law.
    Tillräknande av kunskap inom fullmaktsrätten: - Dags att se bortom behörigheten?2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    En avtalsparts vetskap eller culpösa ovetskap om ett visst betydelsefullt förhållande kan leda till att ett avtal eller en annan rättshandling ogiltigförklaras eller ges ett annat innehåll än eljest. Men hur förhåller det sig när den relevanta vetskapen finns hos den som för avtalspartens räkning framförhandlat avtalet? I denna uppsats kommer författaren att utreda under vilka förutsättningar en mellanmans (fullmäktigs) onda tro får samma betydelse för avtalspartens (huvudmannens) rättsställning som om huvudmannen själv varit i ond tro.

                          Det har från olika håll ifrågasatts om full behörighet att träffa ett avtal måste föreligga för att huvudmannen ska tillräknas ond tro hos en fullmäktig. Tidig rättspraxis ger vid handen att en fullmäktigs insikter och åtgärder under förhandlingar med motparten saknar betydelse vid tolkningen av avtalet, när fullmäktigens behörighet varit begränsad till att förhandla och förmedla anbud. Inte heller i ogiltighetshänseende har en fullmäktigs onda tro utan vidare tillmätts betydelse, när det villkor som tredje man felaktigt utgått från legat utom behörigheten. Den beskrivna ordningen stämmer dåligt överens med hur tredje man i allmänhet uppfattar situationen och den går inte särskilt väl ihop med rättsläget efter det att avtal väl slutits; från och med detta ögonblick kommer huvudmannen (avtalsparten) att ansvara för sina anställda och andra medhjälpare på samma sätt som för sig själv (in contractu).

                          HD har på senare år ändrat sin praxis och mycket talar numera för att huvudregeln är den motsatta; så länge fullmäktigen utrustats med en förhandlingsfullmakt kan hans eller hennes insikt om motpartens uppfattning tillräknas huvudmannen. Vilken rättsföljden blir av ett tillräknande avgörs av ett samspel mellan hur tvisten formuleras av parterna samt vad grundläggande avtals- och fullmaktsrättsliga principer ger vid handen. Utgångspunkten är att huvudmannen inte kan bli bunden av en sidolöpare (d.v.s. ett villkor som inte täcks av behörigheten), men i ogiltighetshänseende ska han stå risken för vad fullmäktigen vet om tredje mans uppfattning. Föreligger emellertid konsensus om avtalets giltighet i sig och tvist endast råder om dess innehåll, måste en tolkning av avtalet göras av domstolen till förmån för den ena eller andra parten. I ett sådant fall får fullmäktigens vetskap om tredje mans uppfattning, en omständighet som normalt endast leder till ogiltighet, betydelse för tolkningen av avtalet.

  • Airey, Sam
    et al.
    Uppsala Univ, Villavagen 16, S-75236 Uppsala, Sweden..
    Krause, Torsten
    Lund Univ, Ctr Sustainabil Studies, S-22100 Lund, Sweden..
    "Georgetown ain't got a tree. We got the trees"-Amerindian Power & Participation in Guyana's Low Carbon Development Strategy2017In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 8, no 3, 51Article in journal (Refereed)
    Abstract [en]

    International bi-lateral agreements to support the conservation of rainforests to reduce greenhouse gas emissions are growing in prevalence. In 2009, the governments of Guyana and Norway established Guyana's Low Carbon Development Strategy (LCDS). We examine the extent to which the participation and inclusion of Guyana's indigenous population within the LCDS is being achieved. We conducted a single site case study, focussing on the experiences and perceptions from the Amerindian community of Chenapou. Based on 30 interviews, we find that a deficit of adequate dialogue and consultation has occurred in the six years since the LCDS was established. Moreover, key indigenous rights, inscribed at both a national and international level, have not been upheld with respect to the community of Chenapou. Our findings identify consistent shortcomings to achieve genuine participation and the distinct and reinforced marginalisation of Amerindian communities within the LCDS. A further critique is the failure of the government to act on previous research, indicating a weakness of not including indigenous groups in the Guyana-Norway bi-lateral agreement. We conclude that, if the government is to uphold the rights of Amerindian communities in Guyana, significant adjustments are needed. A more contextualised governance, decentralising power and offering genuine participation and inclusion, is required to support the engagement of marginal forest-dependent communities in the management of their natural resources.

  • Aaboud, M.
    et al.
    Bergeås, Elin Kuutmann
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Brenner, Richard
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Ekelöf, Tord
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Ellert, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Ferrari, Arnaud
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Madsen, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Öhman, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Rangel-Smith, Camilla
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Zwalinski, L.
    Measurements of top quark spin observables in tt events using dilepton final states in root s=8 TeV pp collisions with the ATLAS detector2017In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 3, 113Article in journal (Refereed)
    Abstract [en]

    Measurements of top quark spin observables in tt¯tt¯ events are presented based on 20.2 fb−1 of s√=8s=8 TeV proton-proton collisions recorded with the ATLAS detector at the LHC. The analysis is performed in the dilepton final state, characterised by the presence of two isolated leptons (electrons or muons). There are 15 observables, each sensitive to a different coefficient of the spin density matrix of tt¯tt¯ production, which are measured independently. Ten of these observables are measured for the first time. All of them are corrected for detector resolution and acceptance effects back to the parton and stable-particle levels. The measured values of the observables at parton level are compared to Standard Model predictions at next-to-leading order in QCD. The corrected distributions at stable-particle level are presented and the means of the distributions are compared to Monte Carlo predictions. No significant deviation from the Standard Model is observed for any observable.

  • Thorleifsdottir, Ragna Hlin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Dermatology and Venereology. Univ Iceland, Dermatol Sect, Fac Med, Reykjavik, Iceland.
    Sigurdardottir, Sigrun Laufey
    Landspitali Natl Univ Hosp Iceland, Dept Immunol, Reykjavik, Iceland..
    Sigurgeirsson, Bardur
    Univ Iceland, Dermatol Sect, Fac Med, Reykjavik, Iceland..
    Olafsson, Jon Hjaltalin
    Univ Iceland, Dermatol Sect, Fac Med, Reykjavik, Iceland..
    Sigurdsson, Martin Ingi
    Landspitali Natl Univ Hosp Iceland, Dept Anesthesiol & Crit Care, Reykjavik, Iceland..
    Petersen, Hannes
    Landspitali Natl Univ Hosp Iceland, Dept Otolaryngol Head & Neck Surg, Reykjavik, Iceland..
    Gudjonsson, Johann Eli
    Univ Michigan, Sch Med, Dept Dermatol, Ann Arbor, MI USA..
    Johnston, Andrew
    Univ Michigan, Sch Med, Dept Dermatol, Ann Arbor, MI USA..
    Valdimarsson, Helgi
    Landspitali Natl Univ Hosp Iceland, Dept Immunol, Reykjavik, Iceland..
    Patient-reported Outcomes and Clinical Response in Patients with Moderate-to-severe Plaque Psoriasis Treated with Tonsillectomy: A Randomized Controlled Trial2017In: Acta Dermato-Venereologica, ISSN 0001-5555, E-ISSN 1651-2057, Vol. 97, no 3, 340-345 p.Article in journal (Refereed)
    Abstract [en]

    Psoriasis is a chronic inflammatory skin disease with profound effects on patients' health-related quality of life (HRQoL). Twenty-nine patients with plaque psoriasis and a history of streptococcal-associated psoriasis exacerbations were randomly assigned to tonsillectomy (n = 15) or control (n = 14) groups and followed for 24 months. Patients were evaluated with the Psoriasis Disability Index, Psoriasis Life Stress Inventory and Psoriasis Area and Severity Index. HRQoL and psoriasis-related stress improved significantly in the tonsillectomy group compared with the control group (p = 0.037 and p = 0.002, respectively), with a mean 50% improvement in HRQoL and a mean 59% improvement in psoriasis-induced stress. Clinical improvement correlated significantly with improved HRQoL (r = 0.297, p = 0.008) and psoriasis-related stress (r = 0.310, p = 0.005). Of the tonsillectomized patients, 87% concluded that the procedure was worthwhile. Tonsillectomy may improve quality of life for selected patients with plaque psoriasis.

  • Nordin, P.
    et al.
    Umea Univ, Swedish Hernia Register, Dept Surg & Perioperat Sci, S-90185 Umea, Sweden..
    Ahlberg, J.
    Swedish Natl Patient Insurance Co, LOF, Stockholm, Sweden..
    Johansson, Henry
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Endocrine Surgery. Swedish Patient Claims Panel, Stockholm, Sweden..
    Holmberg, H.
    Umea Univ, Dept Publ Hlth & Clin Med, Umea, Sweden..
    Hafström, L.
    Univ Gothenburg, Sahlgrenska Univ Hosp, Sahlgrenska Acad, Transplant Inst, Gothenburg, Sweden.;Swedish Patient Claims Panel, Gothenburg, Sweden..
    Risk factors for injuries associated with damage claims following groin hernia repair2017In: Hernia, ISSN 1265-4906, E-ISSN 1248-9204, Vol. 21, no 2, 215-221 p.Article in journal (Refereed)
    Abstract [en]

    Surgical repair of groin hernia should be carried out with minimal complication rates, and it is important to have regular quality control and accurate means of assessment. The Swedish healthcare system has a mutual insurance company (LA-F) that receives claims from patients who have suffered healthcare-related damage or malpractice. The Swedish Hernia Register (SHR) currently covers around 98% of all Swedish groin hernia operations. The aim of this study was to analyse damage claims following groin hernia repair surgery and link these with entries in the SHR, in order to identify risk factors and causes of injuries and malpractice associated with hernia repair. Data on all 48,574 groin hernia operations registered in the SHR between 2008 and 2010 were compared and linked with data on claims made to the Swedish National Patient Injury Insurance (LA-F). Of the 130 damage claims received by LA-F, 26 dealt with bleeding, 20 with testicular injury and 7 with intestinal lesions. Eighty (62%) of the complications were considered malpractice according to the Swedish Patient Injury Act. Acute and recurrent surgery, sutured repair and general anaesthesia were associated with a significantly increased risk for a damage claim independently the patients were compensated or not. Females filed claims in greater proportion than males. There was no significant difference in background factors between claims accepted by LA-F and compensated and those who were rejected compensation. Risk factors for filing a damage claim included acute surgery, operation for recurrence, sutured repair and general anaesthesia, whereas local anaesthesia reduced the risk.

  • Public defence: 2017-06-09 13:00 Enghoffsalen, Uppsala
    Batra, Gorav
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cardiology.
    Atrial Fibrillation in the setting of Coronary Artery Disease: Risks and outcomes with different treatment options2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Coronary artery disease (CAD) is the leading cause of mortality worldwide and atrial fibrillation (AF) is a prevalent arrhythmia associated with increased risk of mortality and morbidity. Despite improved outcome in both diseases, there is a need to further describe the prevalence, outcome and management of CAD in patients with concomitant AF.

    AF was a common finding among patients with MI, with 16% having new-onset, paroxysmal or chronic AF. Patients post-MI with concomitant AF, regardless of subtype, were at increased risk of composite cardiovascular outcome of mortality, MI or ischemic stroke, including mortality and ischemic stroke alone. No major difference in outcome was observed between AF subtypes. At discharge, an oral anticoagulant was prescribed to 27% of the patients with MI and AF undergoing percutaneous coronary intervention (PCI). Aspirin or clopidogrel plus warfarin versus dual antiplatelet therapy with aspirin plus clopidogrel were associated with similar 0-90-day and lower 91-365-day risk of cardiovascular outcome, without increased risk of major bleeding events. Triple therapy with aspirin, clopidogrel plus warfarin versus dual antiplatelet therapy was associated with non-significant lower risk of cardiovascular outcome, but with increased risk of bleeding events. Treatment with renin-angiotensin system (RAS) inhibitors post-MI was associated with lower risk of all-cause and cardiovascular mortality in patients with and without congestive heart failure and/or AF. However, RAS inhibition in patients without AF was not associated with lower risk of new-onset AF. Approximately 1 in 3 patients undergoing isolated coronary artery bypass grafting (CABG) had pre- or postoperative AF. Patients with AF, regardless of subtype, were at higher risk of all-cause mortality, cardiovascular mortality and congestive heart failure. Furthermore, postoperative AF was associated with higher risk of recurrent AF.

    In conclusion, AF was a common finding in the setting of MI and CABG. AF, irrespectively if in the setting of MI or CABG was associated with higher risk of ischemic events and mortality. Also, postoperative AF was associated with recurrent AF. Oral anticoagulants post-MI and PCI in patients with AF was underutilized, however, optimal antithrombotic therapy is still unknown. RAS inhibition post-MI seems beneficial, however, it was not associated with lower incidence of new-onset AF.

    List of papers
    1. All types of atrial fibrillation in the setting of myocardial infarction are associated with impaired outcome
    Open this publication in new window or tab >>All types of atrial fibrillation in the setting of myocardial infarction are associated with impaired outcome
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    2016 (English)In: Heart, ISSN 1355-6037, E-ISSN 1468-201X, Vol. 102, no 12, 926-933 p.Article in journal (Refereed) Published
    Abstract [en]

    Objectives To evaluate 90-day cardiovascular outcome in patients after myocardial infarction (MI) in relation to different subtypes of atrial fibrillation (AF) and MI. Methods We studied 155 071 hospital survivors of MI between 2000 and 2009 in Swedish registries. AF subtypes were defined according to history of AF and in-hospital ECG recordings. Clinical outcomes were evaluated with multivariable Cox models. Results AF was documented in 24 023 (15.5%) cases. The AF subtypes were new-onset AF with sinus rhythm at discharge (3.7%), new-onset AF with AF at discharge (3.9%), paroxysmal AF (4.9%) and chronic AF (3.0%). The event rate per 100 person-years for the composite cardiovascular outcome (all-cause mortality, MI or ischaemic stroke) was 90.9 in patients with any type of AF versus 45.2 in patients with sinus rhythm, adjusted hazard ratio with 95% CI (HR) 1.28 (1.19 to 1.37). There were no significant differences in the composite cardiovascular outcome between AF subtypes. AF was associated with higher risk of mortality, HR 1.59 (1.41 to 1.80), reinfarction, HR 1.14 (1.05 to 1.24), and ischaemic stroke, HR 2.29 (1.92 to 2.74), respectively. In subgroup analysis, AF was associated with a higher risk of composite cardiovascular outcome in the non-ST-elevation myocardial infarction (NSTEMI) and STelevation myocardial infarction (STEMI) cohort, HR 1.24 (1.13 to 1.36) and HR 1.34 (1.21 to 1.48), respectively, with p value for interaction= 0.23. Conclusions AF is common in the setting of MI and is associated with a higher risk of composite cardiovascular outcome and the individual components; mortality, reinfarction and ischaemic stroke, respectively. No major difference in outcome was observed between AF subtypes. No difference in outcome for AF was observed between the NSTEMI and STEMI cohort.

    National Category
    Cardiac and Cardiovascular Systems
    Identifiers
    urn:nbn:se:uu:diva-299058 (URN)10.1136/heartjnl-2015-308678 (DOI)000377548100010 ()26928408 (PubMedID)
    Funder
    Swedish Foundation for Strategic Research , KF10-0024
    Available from: 2016-07-13 Created: 2016-07-13 Last updated: 2017-04-21
    2. Antithrombotic therapy after myocardial infarction in patients with atrial fibrillation undergoing percutaneous coronary intervention
    Open this publication in new window or tab >>Antithrombotic therapy after myocardial infarction in patients with atrial fibrillation undergoing percutaneous coronary intervention
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:uu:diva-320310 (URN)
    Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2017-04-21
    3. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are associated with improved outcome but do not prevent new-onset atrial fibrillation after acute myocardial infarction
    Open this publication in new window or tab >>Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are associated with improved outcome but do not prevent new-onset atrial fibrillation after acute myocardial infarction
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    2017 (English)In: Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease, ISSN 2047-9980, E-ISSN 2047-9980, Vol. 6, no 3, e005165Article in journal (Refereed) Published
    Abstract [en]

    Background Treatment with renin‐angiotensin system (RAS) inhibitors might restrain the structural/electrical remodeling associated with atrial fibrillation (AF). Limited evidence exists regarding the potential benefits of RAS inhibition post‐acute myocardial infarction (AMI) in patients with AF. This study sought to assess the association between RAS inhibition and all‐cause mortality and new‐onset AF in patients with/without congestive heart failure (CHF) post‐AMI.

    Methods and Results Patients hospitalized for AMI between 2006 and 2012 were identified in Swedish registries. Patients were stratified in 4 subgroups; patients with CHF and AF (n=11 489); patients with CHF without AF (n=31 676); patients with AF without CHF (n=10 066); and patients without both CHF and AF (n=59 417). Patients exposed to RAS inhibition were compared to nontreated. Three‐year risk of all‐cause mortality and new‐onset AF was assessed using adjusted Cox regression analyses. At discharge, 83 291 (73.9%) patients received RAS inhibition. RAS inhibition was associated with lower 3‐year risk of all‐cause mortality in CHF patients with AF, adjusted hazard ratio (HR) with 95% CI 0.75 (0.70–0.81), CHF patients without AF, HR 0.65 (0.60–0.69), AF patients without CHF, HR 0.82 (0.75–0.90), and in patients without CHF and AF, HR 0.76 (0.72–0.81), respectively. RAS inhibition was not associated with lower 3‐year risk of new‐onset AF in patients without AF but with/without CHF; HR 0.96 (0.84–1.10) and 1.12 (1.02–1.22), respectively.

    Conclusions RAS inhibition post‐AMI was associated with lower risk of all‐cause mortality. In patients with/without CHF, RAS inhibition was not associated with lower incidence of new‐onset AF.

    Keyword
    atrial fibrillation, myocardial infarction
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:uu:diva-317878 (URN)10.1161/JAHA.116.005165 (DOI)000399322900044 ()28320744 (PubMedID)
    Funder
    Swedish Foundation for Strategic Research
    Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2017-05-15Bibliographically approved
    4. Atrial fibrillation in patients undergoing coronary artery surgery is associated with adverse outcome
    Open this publication in new window or tab >>Atrial fibrillation in patients undergoing coronary artery surgery is associated with adverse outcome
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Clinical Medicine
    Identifiers
    urn:nbn:se:uu:diva-320311 (URN)
    Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2017-04-21
  • Public defence: 2017-06-10 09:00 Rosénsalen, Uppsala
    Senkowski, Wojciech
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    High-throughput screening using multicellular tumor spheroids to reveal and exploit tumor-specific vulnerabilities2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    High-throughput drug screening (HTS) in live cells is often a vital part of the preclinical anticancer drug discovery process. So far, two-dimensional (2D) monolayer cell cultures have been the most prevalent model in HTS endeavors. However, 2D cell cultures often fail to recapitulate the complex microenvironments of in vivo tumors. Monolayer cultures are highly proliferative and generally do not contain quiescent cells, thought to be one of the main reasons for the anticancer therapy failure in clinic. Thus, there is a need for in vitro cellular models that would increase predictive value of preclinical research results. The utilization of more complex three-dimensional (3D) cell cultures, such as multicellular tumor spheroids (MCTS), which contain both proliferating and quiescent cells, has therefore been proposed. However, difficult handling and high costs still pose significant hurdles for application of MCTS for HTS.

    In this work, we aimed to develop novel assays to apply MCTS for HTS and drug evaluation. We also set out to identify cellular processes that could be targeted to selectively eradicate quiescent cancer cells. In Paper I, we developed a novel MCTS-based HTS assay and found that nutrient-deprived and hypoxic cancer cells are selectively vulnerable to treatment with inhibitors of mitochondrial oxidative phosphorylation (OXPHOS). We also identified nitazoxanide, an FDA-approved anthelmintic agent, to act as an OXPHOS inhibitor and to potentiate the effects of standard chemotherapy in vivo. Subsequently, in Paper II we applied the high-throughput gene-expression profiling method for MCTS-based drug screening. This led to discovery that quiescent cells up-regulate the mevalonate pathway upon OXPHOS inhibition and that the combination of OXPHOS inhibitors and mevalonate pathway inhibitors (statins) results in synergistic toxicity in this cell population. In Paper III, we developed a novel spheroid-based drug combination-screening platform and identified a set of molecules that synergize with nitazoxanide to eradicate quiescent cancer cells. Finally, in Paper IV, we applied our MCTS-based methods to evaluate the effects of phosphodiesterase (PDE) inhibitors in PDE3A-expressing cell lines.

    In summary, this work illustrates how MCTS-based HTS yields potential to reveal and exploit previously unrecognized tumor-specific vulnerabilities. It also underscores the importance of cell culture conditions in preclinical drug discovery endeavors.

    List of papers
    1. Three-Dimensional Cell Culture-Based Screening Identifies the Anthelmintic Drug Nitazoxanide as a Candidate for Treatment of Colorectal Cancer
    Open this publication in new window or tab >>Three-Dimensional Cell Culture-Based Screening Identifies the Anthelmintic Drug Nitazoxanide as a Candidate for Treatment of Colorectal Cancer
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    2015 (English)In: Molecular Cancer Therapeutics, ISSN 1535-7163, E-ISSN 1538-8514, Vol. 14, no 6, 1504-1516 p.Article in journal (Refereed) Published
    Abstract [en]

    Because dormant cancer cells in hypoxic and nutrient-deprived regions of solid tumors provide a major obstacle to treatment, compounds targeting those cells might have clinical benefits. Here, we describe a high-throughput drug screening approach, using glucose-deprived multicellular tumor spheroids (MCTS) with inner hypoxia, to identify compounds that specifically target this cell population. We used a concept of drug repositioning-using known molecules for new indications. This is a promising strategy to identify molecules for rapid clinical advancement. By screening 1,600 compounds with documented clinical history, we aimed to identify candidates with unforeseen potential for repositioning as anticancer drugs. Our screen identified five molecules with pronounced MCTS-selective activity: nitazoxanide, niclosamide, closantel, pyrvinium pamoate, and salinomycin. Herein, we show that all five compounds inhibit mitochondrial respiration. This suggests that cancer cells in low glucose concentrations depend on oxidative phosphorylation rather than solely glycolysis. Importantly, continuous exposure to the compounds was required to achieve effective treatment. Nitazoxanide, an FDA-approved antiprotozoal drug with excellent pharmacokinetic and safety profile, is the only molecule among the screening hits that reaches high plasma concentrations persisting for up to a few hours after single oral dose. Nitazoxanide activated the AMPK pathway and downregulated c-Myc, mTOR, and Wnt signaling at clinically achievable concentrations. Nitazoxanide combined with the cytotoxic drug irinotecan showed anticancer activity in vivo. We here report that the FDA-approved anthelmintic drug nitazoxanide could be a potential candidate for advancement into cancer clinical trials.

    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:uu:diva-260735 (URN)10.1158/1535-7163.MCT-14-0792 (DOI)000358054300025 ()25911689 (PubMedID)
    Funder
    Swedish Cancer SocietySwedish Research CouncilSwedish Childhood Cancer Foundation
    Available from: 2015-08-24 Created: 2015-08-24 Last updated: 2017-04-22Bibliographically approved
    2. Large-Scale Gene Expression Profiling Platform for Identification of Context-Dependent Drug Responses in Multicellular Tumor Spheroids
    Open this publication in new window or tab >>Large-Scale Gene Expression Profiling Platform for Identification of Context-Dependent Drug Responses in Multicellular Tumor Spheroids
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    2016 (English)In: CELL CHEMICAL BIOLOGY, ISSN 2451-9448, Vol. 23, no 11, 1428-1438 p.Article in journal (Refereed) Published
    Abstract [en]

    Cancer cell lines grown as two-dimensional (2D) cultures have been an essential model for studying cancer biology and anticancer drug discovery. However, 2D cancer cell cultures have major limitations, as they do not closely mimic the heterogeneity and tissue context of in vivo tumors. Developing three-dimensional (3D) cell cultures, such as multicellular tumor spheroids, has the potential to address some of these limitations. Here, we combined a high-throughput gene expression profiling method with a tumor spheroid-based drug-screening assay to identify context-dependent treatment responses. As a proof of concept, we examined drug responses of quiescent cancer cells to oxidative phosphorylation (OXPHOS) inhibitors. Use of multicellular tumor spheroids led to discovery that the mevalonate pathway is upregulated in quiescent cells during OXPHOS inhibition, and that OXPHOS inhibitors and mevalonate pathway inhibitors were synergistically toxic to quiescent spheroids. This work illustrates how 3D cellular models yield functional and mechanistic insights not accessible via 2D cultures.

    National Category
    Cell and Molecular Biology Cancer and Oncology
    Identifiers
    urn:nbn:se:uu:diva-311191 (URN)10.1016/j.chembiol.2016.09.013 (DOI)000388373200015 ()27984028 (PubMedID)
    Funder
    Swedish Cancer SocietySwedish Foundation for Strategic Research
    Available from: 2016-12-22 Created: 2016-12-22 Last updated: 2017-04-22Bibliographically approved
    3. Drug combination screening in multicellular tumor spheroids identifies synthetic lethalities in quiescent cancer cells
    Open this publication in new window or tab >>Drug combination screening in multicellular tumor spheroids identifies synthetic lethalities in quiescent cancer cells
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Cancer and Oncology Medicinal Chemistry
    Research subject
    Molecular Medicine
    Identifiers
    urn:nbn:se:uu:diva-320596 (URN)
    Available from: 2017-04-22 Created: 2017-04-22 Last updated: 2017-04-22
    4. Targeting tumor cells based on PDE3A expression
    Open this publication in new window or tab >>Targeting tumor cells based on PDE3A expression
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Medicinal Chemistry Cancer and Oncology
    Identifiers
    urn:nbn:se:uu:diva-320597 (URN)
    Available from: 2017-04-22 Created: 2017-04-22 Last updated: 2017-04-22
  • Neteborn, Magdalena
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of Literature, Rhetoric.
    Ethos och Persona på Facebook: En casestudy av Livrustkammarens självpresentation på Facebook2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sociala medier, och särskilt Facebook, skiljer sig mycket från de äldre medierna

    (tidningar, radio, TV etc.) då det är plattformar där “vanliga människor”, utan journalistisk

    skolning, har möjlighet att uttrycka sig inför stora publiker. Det sker en form av

    paradigmskifte i vad som anses retoriskt effektivt och därmed hur vi ska presentera oss

    själva. Jag ser att rollen en administratör tar på en Facebooksida skiljer sig mycket från

    rollen en journalist på en tidning får när de skriver. De presenterar sig på skilda sätt och

    Facebookadministratören håller sig i regel mer personlig och nära sina läsare.

    Syftet med denna uppsats är att undersöka hur retoriska strategier för självpresentation,

    ethos och persona används idag inom Facebook som är ett relativt modernt medium. Det

    är en casestudy med den statliga myndigheten Livrustkammarens Facebooksida som

    exempel. Detta för att de skapat ett rykte kring sig om att vara roliga och effektiva i sin

    kommunikation.

  • Public defence: 2017-06-09 13:00 80101, Uppsala
    Vaicenavicius, Juozas
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Optimal Sequential Decisions in Hidden-State Models2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis consists of five research articles on the general topic of optimal decision making under uncertainty in a Bayesian framework. The papers are preceded by three introductory chapters.

    Papers I and II are dedicated to the problem of finding an optimal stopping strategy to liquidate an asset with unknown drift. In Paper I, the price is modelled by the classical Black-Scholes model with unknown drift. The first passage time of the posterior mean below a monotone boundary is shown to be optimal. The boundary is characterised as the unique solution to a nonlinear integral equation. Paper II solves the same optimal liquidation problem, but in a more general model with stochastic regime-switching volatility. An optimal liquidation strategy and various structural properties of the problem are determined.

    In Paper III, the problem of sequentially testing the sign of the drift of an arithmetic Brownian motion with the 0-1 loss function and a constant cost of observation per unit of time is studied from a Bayesian perspective. Optimal decision strategies for arbitrary prior distributions are determined and investigated. The strategies consist of two monotone stopping boundaries, which we characterise in terms of integral equations.

    In Paper IV, the problem of stopping a Brownian bridge with an unknown pinning point to maximise the expected value at the stopping time is studied. Besides a few general properties established, structural properties of an optimal strategy are shown to be sensitive to the prior. A general condition for a one-sided optimal stopping region is provided.

    Paper V deals with the problem of detecting a drift change of a Brownian motion under various extensions of the classical Wiener disorder problem. Monotonicity properties of the solution with respect to various model parameters are studied. Also, effects of a possible misspecification of the underlying model are explored.

    List of papers
    1. Optimal liquidation of an asset under drift uncertainty
    Open this publication in new window or tab >>Optimal liquidation of an asset under drift uncertainty
    2016 (English)In: SIAM Journal on Financial Mathematics, ISSN 1945-497X, E-ISSN 1945-497XArticle in journal (Refereed) Published
    Abstract [en]

    We study a problem of finding an optimal stopping strategy to liquidate an asset with unknown drift. Taking a Bayesian approach, we model the initial beliefs of an individual about the drift by allowing an arbitrary probability distribution to characterize the uncertainty about the drift parameter. Filtering theory is used to describe the evolution of the posterior beliefs about the drift once the price process is being observed. An optimal stopping time is determined as the first passage time of the posterior mean below a monotone boundary, which can be characterized as the unique solution to a nonlinear integral equation. We also study monotonicity properties with respect to the prior distribution and the asset volatility.

    Keyword
    optimal liquidation, incomplete information, sequential analysis
    National Category
    Mathematics
    Identifiers
    urn:nbn:se:uu:diva-283523 (URN)10.1137/15M1033265 (DOI)000391850000013 ()
    Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2017-04-26Bibliographically approved
    2. Asset liquidation under drift uncertainty and regime-switching volatility
    Open this publication in new window or tab >>Asset liquidation under drift uncertainty and regime-switching volatility
    (English)Article in journal (Other academic) Submitted
    Abstract [en]

    Optimal liquidation of an asset with unknown constant drift and stochastic regime-switching volatility is studied. The uncertainty about the drift is represented by an arbitrary probability distribution, the stochastic volatility is modelled by m-state Markov chain. Using filtering theory, an equivalent reformulation of the original problem as a four-dimensional optimal stopping problem is found and then analysed by constructing approximating sequences of three-dimensional optimal stopping problems. An optimal liquidation strategy and various structural properties of the problem are determined. Analysis of the two-point prior case is presented in detail, building on which, an outline of the extension to the general prior case is given.

    Keyword
    optimal liquidation, model uncertainty, regime-switching volatility, sequential analysis
    National Category
    Probability Theory and Statistics
    Identifiers
    urn:nbn:se:uu:diva-320805 (URN)
    Available from: 2017-04-25 Created: 2017-04-25 Last updated: 2017-04-26
    3. Bayesian Sequential Testing Of The Drift Of A Brownian Motion
    Open this publication in new window or tab >>Bayesian Sequential Testing Of The Drift Of A Brownian Motion
    2015 (English)In: ESAIM. P&S, ISSN 1292-8100, E-ISSN 1262-3318, Vol. 19, 626-648 p.Article in journal (Refereed) Published
    Abstract [en]

    We study a classical Bayesian statistics problem of sequentially testing the sign of the drift of an arithmetic Brownian motion with the 0-1 loss function and a constant cost of observation per unit of time for general prior distributions. The statistical problem is reformulated as an optimal stopping problem with the current conditional probability that the drift is non-negative as the underlying process. The volatility of this conditional probability process is shown to be non-increasing in time, which enables us to prove monotonicity and continuity of the optimal stopping boundaries as well as to characterize them completely in the finite-horizon case as the unique continuous solution to a pair of integral equations. In the infinite-horizon case, the boundaries are shown to solve another pair of integral equations and a convergent approximation scheme for the boundaries is provided. Also, we describe the dependence between the prior distribution and the long-term asymptotic behaviour of the boundaries.

    Keyword
    Bayesian analysis, sequential hypothesis testing, optimal stopping
    National Category
    Probability Theory and Statistics
    Identifiers
    urn:nbn:se:uu:diva-276901 (URN)10.1051/ps/2015012 (DOI)000368218600031 ()
    Funder
    Swedish Research Council
    Available from: 2016-02-16 Created: 2016-02-16 Last updated: 2017-04-26Bibliographically approved
    4. Optimal stopping of a Brownian bridge with an unknown pinning point
    Open this publication in new window or tab >>Optimal stopping of a Brownian bridge with an unknown pinning point
    (English)Article in journal (Other academic) Submitted
    National Category
    Probability Theory and Statistics
    Identifiers
    urn:nbn:se:uu:diva-320806 (URN)
    Available from: 2017-04-25 Created: 2017-04-25 Last updated: 2017-04-26
    5. Wiener disorder detection under disorder magnitude uncertainty
    Open this publication in new window or tab >>Wiener disorder detection under disorder magnitude uncertainty
    (English)Manuscript (preprint) (Other academic)
    National Category
    Probability Theory and Statistics
    Identifiers
    urn:nbn:se:uu:diva-320807 (URN)
    Available from: 2017-04-25 Created: 2017-04-25 Last updated: 2017-04-26
  • Public defence: 2017-06-08 09:15 Polhemsalen, Uppsala
    Frisk, Christopher
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Modeling and electrical characterization of Cu(In,Ga)Se2 and Cu2ZnSnS4 solar cells2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, modeling and electrical characterization have been performed on Cu(In,Ga)Se2 (CIGS) and Cu2ZnSnS4 (CZTS) thin film solar cells, with the aim to investigate potential improvements to power conversion efficiency for respective technology. The modeling was primarily done in SCAPS, and current-voltage (J-V), quantum efficiency (QE) and capacitance-voltage (C-V) were the primary characterization methods. In CIGS, models of a 19.2 % efficient reference device were created by fitting simulations of J-V and QE to corresponding experimental data. Within the models, single and double GGI = Ga/(Ga+In) gradients through the absorber layer were optimized yielding up to 2 % absolute increase in efficiency, compared to the reference models. For CIGS solar cells of this performance level, electron diffusion length (Ln) is comparable to absorber thickness. Thus, increasing GGI towards the back contact acts as passivation and constitutes largest part of the efficiency increase. For further efficiency increase, majority bottlenecks to improve are optical losses and electron lifetime in the CIGS. In a CZTS model of a 6.7 % reference device, bandgap (Eg) fluctuations and interface recombination were shown to be the majority limit to open circuit voltage (Voc), and Shockley-Read-Hall (SRH) recombination limiting Ln and thus being the majority limit to short-circuit current and fill-factor. Combined, Eg fluctuations and interface recombination cause about 10 % absolute loss in efficiency, and SRH recombination about 9 % loss, compared to an ideal system. Part of the Voc-deficit originates from a cliff-type conduction band offset (CBO) between CZTS and the standard CdS buffer layer, and the energy of the dominant recombination path (EA) is around 1 eV, well below Eg for CZTS. However, it was shown that the CBO could be adjusted and improved with Zn1-xSn­xOy buffer layers. Best results gave EA = 1.36 eV, close to Eg = 1.3-1.35 eV for CZTS as given by photoluminescence, and the Voc-deficit decreased almost 100 mV. Experimentally by varying the absorber layer thickness in CZTS devices, the efficiency saturated at <1 μm, due to short Ln, expected to be 250-500 nm, and narrow depletion width, commonly of the order 100 nm in in-house CZTS. Doping concentration (NA) determines depletion width, but is critical to device performance in general. To better estimate NA with C-V, ZnS and CZTS sandwich structures were created, and in conjunction with simulations it was seen that the capacitance extracted from CZTS is heavily frequency dependent. Moreover, it was shown that C-V characterization of full solar cells may underestimate NA greatly, meaning that the simple sandwich structure might be preferable in this type of analysis. Finally, a model of the Cu2ZnSn(S,Se)4 was created to study the effect of S/(S+Se) gradients, in a similar manner to the GGI gradients in CIGS. With lower Eg and higher mobility for pure selenides, compared to pure sulfides, it was seen that increasing S/(S+Se) towards the back contact improves efficiency with about 1 % absolute, compared to the best ungraded model where S/(S+Se) = 0.25. Minimizing Eg fluctuation in CZTS in conjunction with suitable buffer layers, and improving Ln in all sulfo-selenides, are needed to bring these technologies into the commercial realm.

    List of papers
    1. Optimizing Ga-profiles for highly efficient Cu(In,Ga)Se2 thin film solar cells in simple and complex defect models
    Open this publication in new window or tab >>Optimizing Ga-profiles for highly efficient Cu(In,Ga)Se2 thin film solar cells in simple and complex defect models
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    2014 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 47, no 48, 485104- p.Article in journal (Refereed) Published
    Abstract [en]

    Highly efficient Cu(In,Ga)(S,Se)2 photovoltaic thin film solar cells often have a compositional variation of Ga to In in the absorber layer, here described as a Ga-profile. In this work we have studied the role of Ga-profiles in four different models, based on input data from electrical and optical characterizations of an in-house state-of-the-art Cu(In,Ga)Se2 (CIGS) solar cell with power conversion efficiency above 19 %. A simple defect model with mid-gap defects in the absorber layer was compared with models with Ga-dependent defect concentrations and amphoteric defects. In these models optimized single-graded Ga-profiles have been compared with optimized double-graded Ga-profiles. It was found that the defect concentration for effective Shockley-Read-Hall recombination is low for high efficiency CIGS devices and that the doping concentration of the absorber layer, chosen according to the defect model, is paramount when optimizing Ga-profiles. For optimized single-graded Ga-profiles the simulated power conversion efficiency, depending on the model, is 20.5-20.8 %, and the equivalent double-graded Ga-profiles yield 20.6-21.4 %, indicating that the bandgap engineering of the CIGS device structure can lead to improvements in efficiency. Apart from the effects of increased doping in the complex defect models, the results are similar when comparing the complex defect models to the simple defect models. 

    Keyword
    Solar cell, CIGS, modelling, simulation, optimizing, Ga-profile
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Research subject
    Engineering Science with specialization in Electronics
    Identifiers
    urn:nbn:se:uu:diva-235838 (URN)10.1088/0022-3727/47/48/485104 (DOI)000344941100009 ()
    Funder
    Swedish Research Council, B0393101Swedish Energy Agency
    Available from: 2014-11-17 Created: 2014-11-11 Last updated: 2017-04-18Bibliographically approved
    2. Combining strong interface recombination with bandgap narrowing and short diffusion length in Cu2ZnSnS4 device modeling
    Open this publication in new window or tab >>Combining strong interface recombination with bandgap narrowing and short diffusion length in Cu2ZnSnS4 device modeling
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    2016 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 144, 364-370 p.Article in journal (Refereed) Published
    Abstract [en]

    In this work we establish a device model in SCAPS, incorporating bandgap narrowing, short minority carrier diffusion length and interface recombination. The model is based on a reference device with standard structure; sputtered Mo on soda lime glass, a reactively sputtered and annealed Cu2ZnSnS4 (CZTS) absorber layer, chemical bath deposited CdS and sputtered i-ZnO buffer layers, and front contact formed with sputtered ZnO:Al and an evaporated Ni/Al/Ni grid. The efficiency of the reference device is 6.7%. Model parameter values of the absorber layer are based on the analysis of temperature dependent current–voltage (JVT) measurements, capacitance–voltage (CV) and drive-level capacitance profiling (DLCP) measurements, performed on the reference device, and on the comparison of simulated and measured quantum efficiency (QE) and current–voltage (JV) performance. Additional parameters are taken from literature. The key elements, electron–hole pair generation and recombination in the absorber layer, are the main focus in this study. Reported values of the absorption coefficient of CZTS vary around one order of magnitude when comparing data from reflectance–transmission (RT) measurements with ellipsometry measurements, and calculations. Therefore, a modified semi-empirical absorption coefficient, extracted from RT and QE measurements, with the depletion width from CV and DLCP, is presented and used in this study. The dominating recombination path is evaluated with JVT   analysis and the zero Kelvin activation energy (EA,0) is extracted from both temperature dependent open circuit voltage (VOC) and from modified Arrhenius plots. In each case,is found to be substantially smaller than the bandgap energy, even when considering bandgap narrowing due to disorder, which is an indication that the deficit observed in our CZTS device dominated by interface recombination. Finally, a complete device model is established, with JV   and QE simulations in good agreement with corresponding measurements, where the interface has the biggest impact on the Voc deficit, but with clear contribution from bulk recombination, with minority carrier diffusion length 250 nm, and from bandgap narrowing, giving a lower than nominal bandgap energy of 1.35 eV.

    Keyword
    absorption coefficient, CZTS, interface recombination, kesterite, modeling, simulation.
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:uu:diva-268929 (URN)10.1016/j.solmat.2015.09.019 (DOI)000366223900047 ()
    Funder
    Swedish Energy Agency, 32787-3Swedish Research Council, B0393101
    Available from: 2015-12-11 Created: 2015-12-11 Last updated: 2017-04-18Bibliographically approved
    3. Reduced interface recombination in Cu2ZnSnS4 solar cells with atomic layer deposition Zn1-xSnxO buffer layers
    Open this publication in new window or tab >>Reduced interface recombination in Cu2ZnSnS4 solar cells with atomic layer deposition Zn1-xSnxO buffer layers