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The molecular mechanisms by which the black eumelanin biopolymers exert their photoprotective action on human skin and eyes are still poorly understood, owing to critical insolubility and structural heterogeneity issues hindering direct investigation of excitation and emission behavior. Recently, we set up strategies to obtain water-soluble 5,6-dihydroxyindole (DHI)-based polymers as useful models
We have studied the growth of doped InAsyP1-y (InAsP) NWs and InAsP-InP core-shell NWs. Using hydrogen chloride (HCl) we were able to prevent radial growth on the InAsP NWs. Undoped and H2S-doped InAsP NWs had almost pure wurtzite crystal structure, while DEZn-doped NWs showed wurtzite periodically separated by short sections of pure zincblende with rotational twins. Electrical measurements confir
It has been a common practice both in Sweden and worldwide to enclose nuclear reactors with prestressed concrete structures. The prestress level decreases with time from its initial value due to various degradation mechanisms. To ensure that the prestress level is sufficient the tendon force is measured at regular in-service inspections. The intention with this paper is to present a reliability-ba
The analysis of annual extremes of hydrological and meteorological variables is frequently complicated by the presence of gaps in record, and when records are not only fragmented but also short, it is necessary to utilize to the full the information contained in them. One method is to abstract for statistical analysis all extreme events whose peaks exceed a pre-selected threshold value, but the th
Popular Abstract in Swedish Under de senaste decennierna har matematisk modellering av finansiella marknader rönt stor uppmärksamhet både inom akademi och inom industri. Ett område som har visats särskilt intresse är prissättning av finansiella instrument så som optioner. En europeisk köpoption på en underliggande aktie är ett kontrakt som ger innehavaren rätten att vid en förutbestämt tidpunkt, The first part of this thesis deals with approximations of stochastic integrals and discrete time hedging of derivative contracts; two closely related subjects. Paper A considers the problem of approximating the value of a Wiener process. The discretization points are placed at times when the absolute difference between the value of the process and the approximation reaches a threshold level. It i
Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease that can affect the central nervous system. Neuropsychiatric symptoms are found in 25-70% of patients. Using diffusion tensor imaging (DTI) various studies have reported changes in white matter integrity in SLE patients with neuropsychiatric symptoms (NPSLE patients). The purpose of this study was to investigate, if regi
The prevalence of troublesome fear of childbirth (FOC) in Western countries is about 20%, of which approximately 6-10% suffer from severe FOC that impacts daily life. The countries of Sweden and Denmark are quite alike as far as childbirth culture is concerned. However, to some extent they differ in the organisation of midwifery care during the antenatal and labour period, respectively, and this m
The problem of fitting models to measured data has been studied extensively, not least in the field of computer vision. A central problem in this field is the difficulty in reliably find corresponding structures and points in different images, resulting in outlier data. This thesis presents theoretical results improving the understanding of the connection between model parameter estimation and pos
Popular Abstract in Swedish Autoimmuna sjukdomar, såsom typ 1 diabetes, uppstår till följd av en obalans i immunsystemet där immunceller ser kroppens egna vävnader som ett hot och angriper dem. Vid typ 1 diabetes är det de insulin-producerande β-cellerna i bukspottskörteln som förstörs, vilket leder till att man resten av livet får tillföra kroppen insulin genom injektioner. Anledningen till varföAutoimmunity, such as type 1 diabetes (T1D), arises as a result of tolerance breakdown against host tissues, i.e. the β-cells. Central tolerance is established during thymic T cell development and defects in key events during this process could contribute to the pathogenesis of autoimmune diseases. The work presented in this thesis was aiming at unravelling some of those aspects. We have investi
Microscopic diffusion anisotropy in porous materials can be quantified from diffusion NMR data acquired with a combination of directional and isotropic diffusion encoding. A drawback with current pulses sequences for isotropic encoding is that they all rely on spin echo sequences, which are only applicable to pore liquids with long transverse relaxation times and porous materials with negligible i
Magnetomotive ultrasound imaging is an emerging technique where superparamagnetic iron oxide nanoparticles can be used as an ultrasound contrast agent. A time-varying external magnetic field acts to move tissue embedded particles, and ultrasound is used to detect the resulting tissue movement. In experimental phantom studies we have observed a phase lag dispersion in the magnetomotive response in
Recension av Svetlana Aleksijevitj, Kriget har inget kvinnligt ansikte. En utopis röster.
Ankylosing spondylitis (AS) is associated with several extra-articular manifestations. Nephrolithiasis (NL) has not been recognized as one of those, however, several factors known to increase the risk of NL are at play in AS patients. The objective was to estimate rates and predictors of NL in Swedish patients with AS compared to the general population.
Pathological conditions affect several stages of neurogenesis in the adult brain, including proliferation, survival, cell fate, migration, and functional integration. Here we explored how a pathological environment modulates the heterogeneous afferent synaptic input that shapes the functional properties of newly formed neurons. We analyzed the expression of adhesion molecules and other synaptic pr
Stands of pedunculate oak (Quercus robur) planted 50-80 years ago on two types of land (previously forested land and former arable fields) were compared regarding vegetation and soil. Former arable soils were characterized by a higher pH, higher nitrate concentration and higher soil density, but had lower organic matter content and lower ammonium concentration in the topsoil (0-5 cm). These differ
This study reports increasing iron concentrations in rivers draining into the Baltic Sea. Given the decisive role of iron to the structure and biogeochemical function of aquatic ecosystems, this trend is likely one with far reaching consequences to the receiving system. What those consequences may be depends on the fate of the iron in estuarine mixing. We here assess the stability of riverine iron
A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb(-1) of proton-proton collision data recorded by the ATLAS experiment at root s = 8 TeVat the Large Hadron Collider. Five final states, targeting the decays H -> WW*, tau tau, and ZZ*, are examined for the presence of the Standard Model (SM) Higgs boson: two same-ch
All aerobic organisms are to some degree affected by oxidative stress, which is an imbalance between pro-oxidants and antioxidants in favor of the former. Pro-oxidants can damage DNA, proteins and lipids, and as such oxidative stress can carry considerably fitness costs. In mammals excessive calorie intake is a known cause of oxidative stress. We investigated whether in migrant birds, which typica
Addition of surfactants to aqueous solutions of polyelectrolytes carrying an opposite charge causes the spontaneous formation of complexes in the bulk phase in certain concentration ranges. Under some conditions, compact monodisperse multichain complexes are obtained in the bulk. The size of these complexes depends on the mixing procedure and it can be varied in a controlled way from nanometers up
