http://www.diva-portal.org/umu/theses/coming.xsql 7 theses are published to be defended at Umeå University en reference/libraries/digital http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1949 My initial aim was a functional analysis of the conserved Op18/stathmin family of microtubule-regulators, which includes the ubiquitous cytosolic Op18 protein and the neural membrane-attached RB3 and SCG10 proteins. The solved X-ray structure has shown that these proteins form a complex with tubulin -heterodimers via two imperfect helical repeats, which result in two head-to-tail aligned heterodimers in a tandem-tubulin complex. We have analyzed GTP exchange and GTP hydrolysis at the two exchangeable GTP-binding sites (E-site) within the tandem-tubulin complex. A comparison of Op18, RB3 and SCG10 proteins indicates that Op18/Stathmin family proteins have evolved to maintain the two heterodimers in a configuration that restrains the otherwise potent GTPase productive interactions facilitated by the head-to-head alignment of heterodimers in protofilaments. We concluded from these studies that tubulin heterodimers in complex with Op18/stathmin family members are subject to allosteric effects that prevent futile cycles of GTP hydrolysis. To understand the significance of the large differences in tubulin affinity of Op18, RB3 and SCG10, we have fused each of the heterodimer-binding regions of these three proteins with the CD2 cell-surface protein to generate confined plasma membrane localization of the resulting CD2 chimeras. We showed that, in contrast to CD2-Op18, both the CD2-SCG10 and CD2-RB3 chimeras sequester tubulin at the plasma membrane, which results in >35% reduction of cytosolic tubulin heterodimer levels. However, all three CD2-chimeras, including the tubulin sequestration-incompetent CD2-Op18, destabilize interphase microtubules. Given that microtubules are in extensive contact with the plasma membrane during the interphase, these findings indicate that Op18-like proteins have the potential to destabilize microtubules by both sequestration and direct interaction with microtubules. Sm16/SmSLP (Stathmin-Like Protein) has been identified as a protein released during skin penetration of the Schistosoma mansoni parasite. This protein has been ascribed both anti-inflammatory activities and a functional similarity with the conserved cytosolic tubulin-binding protein stathmin/Op18. However, our studies refuted any functional similarity with stathmin/Op18 and we found instead that Sm16/SmSLP is a lipid bilayer binding protein that is taken up by cells through endocytosis. To study immuno-modulatory properties of Sm16/SmSLP, we designed an engineered version with decreased aggregation propensity, thus facilitating expression and purification of a soluble Sm16 /SmSLP protein from the eukaryotic organism Pichia pastoris. Determination of the hydrodynamic parameters revealed that both the recombinant and native Sm16/SmSLP is a ~9-subunits oligomer. The recombinant protein was found to have no effect on T lymphocyte activation, cell proliferation or the basal level of cytokine production of whole human blood or monocytic cells. Interestingly, however, recombinant Sm16 was found to potently inhibit the cytokine response to the Toll-like receptor (TLR) ligands lipopolysaccharide (LPS) and Poly(I:C). Since Sm16 specifically inhibits degradation of the IRAK1 signaling protein in LPS stimulated monocytes, it seems likely that inhibition is exerted proximal to the TLR-complex. kristoffer.brannstrom@molbiol.umu.se 2008-12-18 Brännström, Kristoffer Umeå University, Faculty of Medicine, Molecular Biology (Faculty of Medicine) urn:nbn:se:umu:diva-1949 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1949 2009 application/xml http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1947 Plants have spread to almost everywhere in the world. As they disperse, they meet many different environments to which they may be able to adapt. For a plant species to adapt to a new environment, genetic variation is needed. The individuals differ from each other in their genetic composition, which often means differences in phenotypes. Those individuals that manage to reproduce will form the next generation. With different conditions in different environments, it will not be the same phenotypes that reproduce everywhere. In that way, plant species will form into a mosaic of locally adapted populations varying genetically as the species disperses. After the last ice age plants have started to disperse away from the equators. With increasing latitudes come increasing challenges to migrating plants. As plant species disperse northwards along this gradient of varying conditions individuals are selected for cold adaptive traits like flowering time and freezing tolerance, acquired by cold acclimation. In this way, genetic variation from the original populations for these traits becomes sorted out along a latitudinal cline. The aim of this thesis was to understand how selection along a latitudinal gradient has shaped natural variation in cold adaptive traits in plants dispersing northwards, and specifically, to investigate what variation can be observed in phenotypes for these traits and how these traits correlate with genetic variation in genes known to be involved in cold acclimation. In this study significant variation was found in a sample of the model plan Arabidopsis thaliana accessions in cold adaptive traits flowering time and freezing tolerance. A clear latitudinal cline in the cold adaptive traits freezing tolerance for A. thaliana was observed. Analysis of nucleotide polymorphism for the cold responsive ICE1 (inducer of CBF expression 1) transcription factor revealed a haplotype structure with two allelic clades as well as unusually high levels of synonymous polymorphism. Nucleotide polymorphism analysis for the transcription factors CBF1, CBF2 and CBF3 (C-repeat binding factors) that play a key role in regulating the expression of a group of target genes known as the “CBF regulon” showed a distinct geographical haplotype structure. One haplotype was dominant in southern accessions while in the other northern accessions overrepresented. There was a significant effect of CBF haplotype on both freezing tolerance and flowering time even after correcting for latitude. Significant differences in CBF expression levels were found between the different CBF genes as well as between different accessions. Sequence variation at CBF was shown to have a significant effect on expression levels of CBF2. No clear correlations were found between CBF gene expression and freezing tolerance or temperature sensitivity for any of the accessions used in the study. This highlights the complex relationship between sequence variation in candidate genes and gene expression, and the problems associated with unraveling the genetic basis of ecologically important traits. antoine.bos@emg.umu.se 2008-12-18 Bos, Antoine Umeå University, Faculty of Science and Technology, Ecology and Environmental Science urn:nbn:se:umu:diva-1947 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1947 2008 application/xml http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1951 This thesis examines strategies and practices, in Soviet ethnographic research, concerning terminologies for and classifications of what in research texts are conventionally called “supernatural beings” in the world views of the Samoyedic peoples. The question is put whether there are any general rules for the terminology used by scholars for these kinds of beings. The thesis also explores claims that a conventional ethnographic terminology, consisting of technical terms such as gods, goddesses, spirits, owners etc., leads to misinterpretations of the indigenous conceptions under study. By presenting, analysing and discussing Soviet scholars’ strategies and practices in this regard, the thesis is a contribution to the ongoing debate among historians of religions on the use of scientific terminology for beings in different world views. It is also, to a limited extent, a source critical investigation of Soviet research on the religions of the Samoyedic peoples. In chapter 2 the international scholarly debate on terminology for so called supernatural beings is summarized and discussed. The principles for constructing concepts in general are also delineated, using prototype theory and a model for polythetic definition. In chapter 3 a survey over the purposes, main fields of interest, and theoretical and methodological development of Soviet ethnography is presented as an essential background to the investigation of individual ethnographic texts. Chapter 4 and 5 constitute the empirical part of the thesis, with a presentation and analysis of Soviet ethnographic descriptions of beings in the world views of the Samoyedic speaking Nenets, Enets, Sel’kup and Nganasan. Since findings on Nganasan world view in Soviet ethnography was seen as particularly viable for reconstructions of proposed primitive communist thought, matriarchal society, the origin of religion, and mankind’s development of beliefs in “spirits” and “gods”, chapter 5 is solely dedicated to the research on the Nganasan. In chapter 6 the result of the empirical part of the study is confronted with the questions put in chapter 1, as well as the theoretical and methodological conclusions of chapter 2. It is concluded that there is no typical Marxist-Leninist terminology for “supernatural beings”, but that certain developments regarding terminology and classifications in Soviet ethnography on the Samoyeds can be detected. These developments consists of (1) a growing awareness among ethnographers of the distinction between indigenous, emic and etic terminology – an awareness which makes their descriptions become more detailed and closer to the Samoyedic sources. (2) From the 1960s one can trace an ever deepening reliance on Marxist-Leninist theory in Soviet Samoyedology. In accordance with Marxist ideas about primeval society as matriarchal and non-religious, ethnographers focused more and more on (and discovered more) female beings in Samoyedic world views. They also interpreted the “beings” under study as remnants of a primeval materialistic world view and proposed explanations of their development from “natural” to “supernatural beings”. It is also concluded that there are no general rules for scientific terminology. Technical terms are chosen in accordance with the varying aims and theoretical standpoints of different scholars. Whether the terms are appropriate or not, depends on their transparency. olle.sundstrom@religion.umu.se 2008-12-19 Sundström, Olle Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies urn:nbn:se:umu:diva-1951 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1951 2008 application/xml http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1944 More girls into science and technology have been a repeated goal in Swedish school politics for some decades. It has been called the gender equality issue. However, neither the ideas associated with science education nor the ideas associated with gender are obvious. The aim of the thesis is to analyse different views of gender, science and technology in Swedish educational policy, as they appear over time in the preparatory documents of the curricula of the nine year comprehensive compulsory school. The purpose is thus to understand the recurrent theme of “girls and science and technology”. The study is a text analysis and the empirical material consists of commission reports, government proposals, motions and minutes of the ensuing parliamentary debates. In the earliest documents girls and boys were described as opposites and their differences were emphasised. However these ideas were not unchallenged. Gender differences were toned down, variations within the genders were emphasised, and it was pointed out that boys and girls are not uniform groups. It was argued that calling areas and tasks female and male are conventions that can be broken. Proposals were made implying a breaking up of the strict boundary between girls’ and boys’ respective spheres of activity. Later a lot of the old ideas were recurring although society had changed. However clear attempts to break the gender borders were also repeated. In this ambition technology was central. From the early 1960s a girl choosing technology stands out as a symbol of a pupil making a gender-crossing choice. Maria.Hedlin@hik.se 2008-12-11 Hedlin, Maria Umeå University, Faculty of Teacher Education, Mathematics, Technology and Science Education urn:nbn:se:umu:diva-1944 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1944 2009 application/xml http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1950 The extracellular matrix (ECM) offers a protective shelter for cells and provides signaling paths important for cell to cell communication. ECM consists of basement membranes (BM) and interstitial matrix. BMs provide mechanical support for parenchymal cells, influence cell proliferation, survival, migration and differentiation. They are also important for tissue integrity. Laminins (LM) are the major non-collagenous component of BMs. Cell-ECM interactions, mediated by receptors, are indispensable during embryonic development, wound healing, remodeling and homeostasis of tissues. The integrins are the major cell-adhesion receptors. The expression of alpha11 integrin chain in the cornea is of great interest, as it is part of the alpha11beta1 integrin receptor for collagen type I, the predominant component of the corneal stroma. The aims were to thoroughly characterize the ECM in the developing and adult human eye, with particular focus on the cornea, LM and alpha11 integrin chains, and to examine alpha11 integrin chain in an animal model of corneal wound healing and remodeling. Human fetal eyes, 9-20 weeks of gestation (wg), and adult human corneas with different diagnosis were treated for immunohistochemistry with specific antibodies against LM and alpha11 integrin chains. Normal and knockout (ko) mice were treated with laser surgery to create a deep wound in the corneal stroma. The wound healing process was followed at different time points. The cellular source of alpha11 integrin chain was studied in cell cultures. In the fetal eyes, the BM of the corneal epithelium, the Descemet’s membrane (DM) and the Bruch’s membrane each had their specific combinations of LM chains and time line of development, whereas the lens capsule and the internal limiting membrane showed constant LM chain patterns. The epithelial BMs of normal and diseased adult corneas contained similar LM chains. The normal morphology of the epithelial BM was altered in the different diseases, particularly when scarring was present. In the scarred keratoconus corneas there were excessive LM chains. The majority of keratoconus corneas also expressed extra LM chains in the DM. At 10-17 wg alpha11 integrin chain was present in the human corneal stroma, especially in the anterior portion, but it was scarce at 20 wg, in normal adult corneas and in Fuchs’ endothelial dystrophy. In contrast, it was increased in the anterior portion of the stroma in keratoconus corneas with scarring. Alpha11 integrin ko mice had a defective healing with subsequent thinner corneas. Alpha11 integrin expression correlated to the presence of alpha-smooth muscle actin in vivo as well as in vitro. The distinct spatial and temporal patterns of distribution for alpha11 integrin and each of the LM chains suggest that they play an important role in human ocular differentiation. The selectively affected LM composition and the novel expression of alpha11 integrin chain in scarred keratoconus corneas as well as the pathologic healing in ko mice, indicate that alpha11 integrin and LM chains also play an important role in the process of corneal healing, remodeling and scarring and might participate in the pathogenesis of corneal disease. This knowledge is of practical importance for future topical therapeutic agents capable of modulating the corneal wound healing processes. berit.bystrom@anatomy.umu.se 2008-12-19 Byström, Berit Umeå University, Faculty of Medicine, Clinical Sciences, Ophthalmology Umeå University, Faculty of Medicine, Integrative Medical Biology, Anatomy urn:nbn:se:umu:diva-1950 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1950 2009 application/xml http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1948 Liquid chromatography is an analytical technique that is constantly facing new challenges in the separation of small molecules and large biomacromolecules. Recently the development of ultra high pressure liquid chromatography has increased the demand on sturdy particles as stationary phase. At the same time the particle size has decreased to sub-2 µm and packed into shorter analytical columns. This thesis deals with the development of new ways of preparing particulate polymer materials using divinylbenzene (DVB) as crosslinker. It includes a novel procedure for synthesizing monodisperse polymer particles by photoinitiated precipitation polymerization. A 150 W short arc xenon lamp was used to initiate the polymerizations. The synthesized particles are monodisperse and have an average particle size ranging from 1.5 to 4 μm depending on reaction conditions and have subsequently been used as grafting templates. The surface of DVB particles contains residual vinyl groups that serve as anchoring points for further functionalization via a variety of grafting schemes. Copolymerization with incorporation of 2,3-epoxypropyl methacrylate yielded pendant oxirane groups on the particle surface. Atom transfer radical polymerization (ATRP) was used to graft methacrylates from the surface resulting in a core-shell type material. A “grafting to” scheme was used to attach pre-made sulfopropyl methacrylate telomers onto particles containing oxirane rings. Populärvetenskaplig sammanfattning på svenska Vätskekromatografi är en analytisk kemisk teknik som ständigt står inför nya utmaningar när det gäller att separera allt från små organiska föreningar till stora makro¬molekyler. Denna avhandling beskriver tillverkning av polymera partiklar med exceptionellt jämn storleksfördelning och ytmodifiering av dessa, för användning som stationärfas i kromatografi¬kolonner. Polymeriserings¬tekniken som används är utfällnings¬polymerisering där lösningen UV-bestrålas av en 150 W xenonlampa. Monomeren (byggstenen) löses tillsammans med en intiator i ett lösningsmedel och efterhand som polymeriseringen fortskrider faller polymerpartiklarna ut. Polymerpartiklarna är gjorda av monomeren divinylbensen som fungerar som en tvärbindare, dvs att den länkar ihop flera kedjor till ett hårt litet nystan. Partiklarna växte till en storlek på 1,5 till 4 µm under två till fyra dygn. Efter tillverkningen är partiklarnas yta täckta av vinylgrupper som kan användas för att fästa funktionella polymerkedjor. Genom att tillföra monomeren 2,3-epoxipropyl¬metakrylat i polymeriseringen kunde man desutom få en partikelyta som innehöll epoxigrupper. Epoxigrupperna användes för att fästa positivt laddade polymerkedjor av bestämd längd. Materialet packades i en kromatografikolonn och användes för att separera en testlösning bestående av fyra proteiner. Partiklarna användes även som bas för ymppolymerisering där den vinyltäckta ytan fått reagera med vätebromid. Detta gör att partiklarna blir stora makroinitiatorer som kan användas för att på ett kontrollerat sätt låta polymerkedjor växa från ytan. I en undersökning ympades 2,3-epoxypropylmetakrylat från ytan på partiklarna och resultatet blev ett tjockt ytskikt. Epoxigrupperna kunde sedan hydrolyseras till dioler vilket gjorde partiklarna mer hydrofila. fredrik.lime@chem.umu.se 2008-12-18 Limé, Fredrik Umeå University, Faculty of Science and Technology, Chemistry urn:nbn:se:umu:diva-1948 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1948 2008 application/xml http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1953 With a post-structural approach and an analytical focus on processes of governmentality and biopower, this study is concerned with how discourses of health are contextualized in educational practice and interaction between educators and participants in workplace health promotion (WHP) interventions. Of concern are issues of the discursive production, regulation and representation of power, knowledge and subjects as gendered beings in workplace health promotion interventions. The methods for generating data are participant observation, interviews and gathering of documentation pertaining to four different workplace health promotion nterventions. Based on these data, the thesis offers an analysis of the health discourses drawn on in the interventions and the technologies of power and of the self by which the participants are governed and invited to govern themselves in the name of health. It also asks what practices and positions that thus come to be made available or not to the participants. Two health discourses are identified: the biomedical discourse and the wellness discourse. Both discourses are drawn on in all four studied interventions, the biomedical discourse being the dominating discourse drawn on. The biomedical discourse is informed by scientific ‘facts’ and statistics and is underpinned by a notion of risk. The wellness discourse is informed by an understanding of health as a subjective embodied experience and is underpinned by a notion of pleasure. Drawing on these discourses, the responsibility for health is placed with the participants and the healthy participant/employee is constituted as a rationally motivated risk-avoider and disciplined pleasure seeker who is both willing and able to actively make ‘good’ choices regarding their lifestyle. Furthermore, and informed by essentialist and heteronormative ideas about gender, the ideal healthy person is modelled on a male norm, representing women as the deviant Other. b2000erika@hotmail.com 2008-12-22 Björklund, Erika Umeå University, Faculty of Social Sciences, Education urn:nbn:se:umu:diva-1953 http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1953 2008 application/xml