| 1. |
- Hamsten, Carl, 1981-
(författare)
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Protein based approaches to understand and prevent contagious bovine pleuropneumonia
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Contagious bovine pleuropneumonia (CBPP) is a severe infectious disease caused by Mycoplasma mycoides subsp. mycoides small colony type (M. mycoides SC) and is a vast problem in Africa. Current CBPP prevention is based on attenuated live strain vaccines, but these are limited by factors such as short-term immunity, cold-chain dependence and retained virulence. CBPP can be diagnosed using post-mortem examination, identification of the agent using culture and PCR based methods as well as serological diagnostic methods, but the latter are generally not sensitive enough and there is also demand for an inexpensive, pen side field test.The research presented in this thesis was focused on using recombinantly expressed surface proteins from M. mycoides SC to characterize humoral immune responses to CBPP. Thereby candidate proteins to be used in development of serological diagnostic methods and possibly subunit vaccines could be identified. As a first step, five putative variable surface proteins of M. mycoides SC were expressed and purified from E. coli in Paper I. These proteins were analyzed using immunoblotting techniques and results showed that one protein, MSC_0364, was variably expressed on the surface of M. mycoides SC in vitro. Paper II presents expanded efforts including cloning and expression of 64 recombinant surface proteins and an assay for high throughput analysis of protein-specific IgG, IgA and IgM titers in hundreds of sera using a bead-based screening assay. The assay was evaluated by protein-specific inhibition experiments, comparisons to Western blotting and monitoring of immune responses over time in a study with sera taken from eight animals over 293 days from a previous vaccine trial.Papers III and IV present applications using the recombinant proteins and bead-based screening assay wherein proteins for diagnostic and vaccine development were identified. In Paper III, the assay was used to screen 61 proteins using well-characterized serum samples from cattle with CBPP and healthy controls, resulting in selection of eight proteins suitable for diagnostic use. These proteins were combined and evaluated in a proof-of-concept ELISA with a discriminative power that enabled 96% correct classification of sera from CBPP-affected and CBPP-free bovines. Paper IV reports the results and protein-specific analyses of a vaccine trial using the recombinant putative variable surface proteins presented in Paper I as a subunit vaccine. The vaccine conferred no protection, but a weak vaccine response could not be excluded as the cause of failure. In an effort to identity other protein candidates to be used in a subunit vaccine, protein-specific analysis of humoral immune responses elicited by the currently approved live strain vaccine, T1/44, were investigated. Here, five proteins with high IgG titers associated to immunity were identified: LppQ, MSC_02714, MSC_0136, MSC_0079 and MSC_0431. These proteins may be important in the development of a novel subunit vaccine against CBPP.
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| 2. |
- Holmlund, Sofia, 1972-
(författare)
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Jorden vi ärvde : Arvsöverlåtelser och familjestrateger på den uppländska landsbygden 1810-1930
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates inheritance among landowning families in the parish of Estuna in east-central Sweden between 1810 and 1930. The patterns of action examined in the study are analyzed as strategies in terms of objectives and principles on the one hand, and means towards these objectives and principles on the other. Before 1885, strategies were based on family interest. The individual’s dependency on inheritance was strong: a fact manifesting itself e.g. in the strong connections between inheritance and matrimonial patterns. The principal goal of the family strategies was to accomplish a transfer of the estate under sustainable conditions to one of the heirs, preferably – but not necessarily – a son. After 1845, as a response to institutional and social change, forms of conveyance changed. For example, after the introduction of equal rights of inheritance between sons and daughters in 1846, the number of quasi-commercial sales of land directly to sons increased, as a way of circumventing judicial demands. Yet this change of action in no way counter-acted the comprehensive goals and principles of inheritance. On the contrary, it was a means to overcome new difficulties in accomplishing these goals. After 1885, inheritance strategies reflected individual, rather than collective, aims. Estates were parcelled and the lots sold by the heirs at a profit. Furthermore, matrimony no longer showed connection with the spouses’ respective inheritance. This development was a result of institutional developments as well as of economic change, both diminishing paternal power. Industrialization had created openings outside domestic agriculture, and so individuals became less dependent on family and family resources. During this period, the older generation tended to keep their estates as long as possible, and this was read as a defensive strategy aimed at continued maintenance of estates within the family.
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| 3. |
- Jonasson, Sofia, 1980-
(författare)
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Lung mechanics and airway inflammation in murine models of asthma
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Allergic asthma is an inflammatory disease of the airways and is characterized by eosinophilic inflammation and increased airway reactivity. In the studies presented in this thesis, lung mechanics and measurements of airway reactivity were assessed in anaesthetized tracheostomized mice by using an animal ventilator (flexiVent®). A forced oscillation technique makes it possible to measure of both airway and tissue mechanics with a potential to distinguish between central and peripheral airways. The results of the experiments on lung mechanics imply that it is important to understand how altered lung mechanics can affect the airway physiology in order to assess the relevance of different animal models of asthma. We have investigated the effects of changing different components of the lung mechanical measurements, such as administering bronchoconstrictive agents via inhalation or intravenously and implementing deep inhalation in animals with airway inflammation. We have also investigated the relation between airway inflammation and oxidative stress. We found that the formation and time-course of F2-isoprostanes, a marker of oxidative stress, and tissue damage were associated with the degree of inflammation and with the degree of heterogeneous airway airflow. Finally we wished to investigate the hypothesis that nitric oxide (NO) may interact with glucocorticoid (GC) treatment because we see a potential for finding new strategies to increase the therapeutic effect in poor responders or patients resistant to GC treatment. NO plays a central role in physiological regulation of the airway function, and is involved in asthma. We found that the concomitant administration of NO and GC attenuated the airway reactivity more than either treatment alone. In conclusion, with the information presented in this thesis, we hope to contribute to the development of better experimental tools and to improved understanding of murine models of asthma for investigating and understanding the underlying pathophysiology of asthma.
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| 4. |
- Persson, Carl, 1967
(författare)
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Den hemliga sjön – en resa till det småländska inlandet för 9 000 år sedan
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis is based on the excavation of a Stone Age site approximately 9,300 years old located in the south Swedish inland. Although the site delivered very few finds it was a site of considerable potential merit. The landscape in the forested region was to a considerable extent untouched by human activity. As there were no natural deposits of flint in the area, all flint had been brought to the site from the coast. A GIS-based analysis enabled small concentrations of finds to be identified and analyzed. The analysis included both technological interpretations and use-wear analyses. The results of these analyses showed that many different tasks were carried out on the site although almost no tools or blades were produced at the site. All flints found were the remnants of sharpening and retouching, consciously discarded or lost. An analysis of the 14C-datings from other sites showed that the inland was only visited sporadically during the first few millennia after the end of the ice age. There are no data which indicate permanent settlement in the inland during the Mesolithic. The inland was thus not colonized in the conventional sense. It was not a linear process and different areas acquired different significances during different periods. The motivation to explore the inland was not primarily ecological or economical. Instead the landscape was analyzed from a social perspective. The starting point was Maurice Bloch's description of man's ability to assume various societal roles and give their environment a social dimension. From this perspective, the landscape, journeys and animals were all various aspects of the same social phenomenon. Keeping this fundamental pre-requisite in mind, the author goes on to analyze the landscape from several different perspectives. Taking his inspiration from Claude Lévi-Strauss, he compares the interior of the country and the coast from a structural perspective, stating that one possible reason for visiting the interior was that it provided a direct contrast to people's everyday life on the coast. People's desire to change and expand their social roles inevitably led them to move between the inland and the coast.
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| 5. |
- Persson, Katarina Sofia, 1972-
(författare)
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Deformation zones in models and nature
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Field studies encounter several complicating factors not studied in the models. Examples are oblique convergence, heterogeneous materials and thermal softening by intruding magmas. Within the deeply eroded Svecokarelian orogeny, studies in eastern Bergslagen indicate strain accommodation of the N-S orogenic shortening by regional E-W folding and shear along the conjugate Singö Shear Zone and Ornö Banded Series. Rising temperature resulted in migmatites affecting the strain accommodation resulting in decoupling and rotation of folds along one of the deformation zones.Deformation zones developed in convergent orogens have been studied in both analogue models and in nature. These studies have focused on a number of important factors controlling strain accommodation during orogenesis. The models show that the shape of the leading edge of the indenting continent controls whether the initial suture remains active or if an effective indenter develops, the spacing and number of faults, the width of the orogen and the height of the mountains. All these characteristics depend on the rate and spatial distribution of erosion and sedimentation. Erosion decreases the importance of effective indenters and favors shearing on existing faults leading to steeper, longer lived shears bounding narrow orogens. If sediments load the margin (e.g. foreland), the thrusts propagate further outboard widening the orogen. The strain that is accommodated by compaction and shearing along deep décollement and conjugate imbricate shears is episodic in time. This work links episodes of increased rates of erosion and sedimentation to episodes of high uplift rates, i.e. the development of new imbricate thrusts or pop-up wedges.
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| 6. |
- Persson, Per-Eskil
(författare)
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Räkna med bokstäver! En longitudinell studie av vägar till en förbättrad algebraundervisning på gymnasienivå
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Huvudsyftet med studien är att skapa insikter om algebrakunskaper och villkor för algebralärande hos gymnasieelever. Ett andra syfte är att med utgångspunkt i resultaten föreslå vägar till en förbättrad algebraundervisning inom det svenska skolsystemet. Studien bygger på ett längre forsknings- och utvecklingsprojekt, som kan indelas i fyra faser. I den empiriska grundstudien följdes två årskullar elever under sin studietid på en gymnasieskola i Sydsverige, och några huvudfaktorer för framgång i algebrastudierna identifierades. Denna delstudie har närmare presenterats i min licentiatuppsats.De tre följande faserna är beskrivna i de tre artiklar, som denna avhandling vilar på. I den andra delstudien reflekterar jag över vad min utveckling från att bara vara lärare till att även bli forskare betytt för min förståelse för vad som händer i klassrummet och på vilka sätt detta förändrat mitt sätt att undervisa. I den tredje fördjupas analysen av elevernas svar på frågan om hur ett centralt funktionssamband kan förklaras. Den fjärde delstudien är en litteraturöversikt över nyare forskning kring räknares och andra teknologiska verktygs inverkan på algebrakunskaper och –lärande.Samtliga delstudier sätts in i ett övergripande sammanhang som utgår från den didaktiska triangeln med huvuddelarna: den lärande/eleven, läraren/undervisningen och det lärda/resultatet av undervisningen. Som bakgrund för studien används ett teoretiskt ramverk bestående av fem huvudkomponenter: matematik och matematikfilosofi, teorier om kunskap och lärande, symbolernas betydelse, representationsformer och verktyg för lärande. En utförlig översikt över tidigare forskning inom området algebraundervisning ges, med ett multidimensionellt perspektiv och med speciellt fokus på delområden av betydelse för studien.En rad resultat från de olika delstudierna presenteras och sammanställs, utgående från såväl det teoretiska ramverket som den didaktiska triangeln. Dessa resultat bildar sedan utgångspunkt för viktiga implikationer för undervisningspraktiken i matematik inom områdena: kunskap och kunskapsutveckling, symboler och representationsformer, algebra som en röd tråd i matematikundervisningen, teknologi i matematikundervisningen och de affektiva faktorernas betydelse. Dessutom ges förslag till lärare om olika metoder och tillvägagångssätt för lokala utvecklingsarbeten på skolorna, samt förslag till vidare forskning.
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| 7. |
- Wilkens, Carl, 1968-
(författare)
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Auri sacra fames : Interest Rates -- Prediction, Jumps and the Market Price of Risk
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of three essays investigating different aspects of interest rates."Prediction of Future Risk-Neutral Short-Term Interest Rate Densities: Can the Black, Derman and Toy Model Assist?" (Co-authored with David Vestin.) This essay evaluates two different approaches to inferring expectations of future interest rates from asset prices. One is based on bond data and builds on the Black, Derman and Toy model, the other is based on option prices. We compare the outcome with a specified assumed benchmark data generating process. The main conclusion is that the option based model works well, whereas the bond based model has difficulties in capturing aspects of the true distribution."Natura non facit saltum – Or Are Jumps an Inherent Feature in European Interest Rate Markets?" A jump-enhanced diffusion model for the instantaneous interest rate is estimated on the EURIBOR, LIBOR and STIBOR one-week interest rates via the characteristic function and a Fourier transform to recover the density function. This is compared with an estimated non-jump diffusion model. Both continuous-time and discrete-time versions of the model are estimated. For all three interest rate series, likelihood ratio tests favor the jump-enhanced model at a statistically significant level. This result holds for both the continuous-time and the discrete-time versions of the model."Estimating the Market Price of Risk in European Interest Rate Markets Using Spectral GMM." The market price of risk in European interest rate markets, constituted by the market price of diffusion risk and the market price of jump risk, is estimated for a jump diffusion model, using the characteristic function and the Generalized Method of Moments. Utilized data is the EURIBOR twelve-month interest rate during 1999-2003. The results are in line with earlier studies on US interest rate markets. The estimation technique appears promising in its technical simplicity, but entails practical estimation difficulties such as start-value sensitivity and lack of efficiency.
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