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Popular Abstract in Swedish Med ett stokastiskt fält (random field) kan man matematiskt modellera en yta vars struktur och variationer i större eller mindre utsträckning kan beskrivas som slumpmässiga. Ett typexempel är havsytan. Det finns vissa ''regler'' för hur den kan se ut, men det exakta utseendet hos en viss våg uppfattas som slumpmässigt. Reglerna omfattar bland annat medelnivån, huIn this thesis the focus is on crossing points in random fields and the probability distributions of various crossing variables in different applications. The crossing points are generalisations to random fields of points of level crossings by stochastic processes. Only crossing events that occur at distinct points in the parameter space are considered, for example stationary points (zero-crossing

Aims Prospective studies of autonomic nerve function are rare. We have followed the progression of autonomic dysfunction in relation to nephropathy over 14 years in Type 1 diabetic patients. Methods Autonomic nerve function was assessed by heart-rate responses to deep breathing (E/I ratio) and tilting (acceleration and brake indices) and by the postural blood pressure reaction in 58 patients, 43

For linear systems with quadratic loss the optimal control is a linear feedback from all the state variables of the system. If all the states are not measurable, it is sometimes possible to construct a suboptimal linear regulator which is almost as good as the full optimal. In this report an algorithm is deduced, which computes a suboptimal strategy when the statistics of the initial state of the

Common to all DMT/OFDM systems is a large peak-to-average ratio (PAR), which can lead to low power efficiency and nonlinear distortion. Tone reservation uses unused or reserved tones to design a peak-canceling signal to lower the PAR of a transmit block. In DMT ADSL systems, the power allocated to these tones may be limited due to crosstalk issues with many users in one twisted pair bundle. This P

In behavioral experiments, the hawkmoth Deilephila elpenor can learn both the color and the position of artificial flowers. When very similar colors are used, moths select the correct color during the first test on a given day, thus using a stimulus strategy, but after repeated rewards, they switch to a place strategy and choose the flower in the position where they received the reward. When dissi

Objective: Reduction of cortisone to cortisol is mediated by 11 beta-hydroxysteroid dehydrogenase type 1 (11 beta HSD1), a putative key enzyme in obesity-related complications. Experimental studies suggest that adipokines, notably leptin and tumor necrosis factor-alpha (TNF-alpha), are of importance for 11 beta HSD1 activity. We hypothesized that the regulation of hepatic preceptor glucocorticoid

89 children from 20 countries adopted to Swedish parents between 1984 and 1988 were tested for the presence of hepatitis C antibodies (anti-HCV). Sera taken soon after their arrival to Sweden were retrospectively analyzed. Two children, an 18-month-old boy from Poland and an 8-month-old girl from India, were anti-HCV positive. The girl from India had lost the anti-HCV antibodies in sera taken at t

Adsorption of pyridine to TiO2 anatase(1 0 1) surfaces via carboxylic acid and phosphonic acid anchor groups has been investigated using periodic DFT calculations. Stronger adsorption is observed for pyridine-4-phosphonic acid than for pyridine-4-carboxylic acid. Periodic molecular orbitals are visualized, and surface electron transfer properties are interpreted in terms of the orbital mixing. Mor

A recursive algorithm is proposed for estimation of parameters in mixture models, where the observations are governed by a hidden Markov chain. The performance of the algorithm is studied by simulations of a symmetric normal mixture. The algorithm seems to be stable and produce approximately normally distributed estimates, provided the adaptive matrix is kept well conditioned.

The interaction between human papillomavirus (HPV) particles and cell surface heparan sulfate requires intact conformation of the HPV particles. Type-specific HPV serology is currently based on virus-like particles (VLPs) with intact conformation. Presence of incorrectly folded VLPs in VLP preparations is recognized as an important cause of cross-reactivity in HPV serology. Heparin-coated microtit

I formulate a simple model of the ultimatum game, in which a proposer and a responder can receive a reward if they agree on how to divide this reward between them. The model is easy to analyse and shows that strong tendencies to fair division are expected when evolution of strategy frequencies follow the traditional gradient dynamics assumed in evolutionary models. The mean stable offer is typical

We present some results on the existence of bounded positive solutions to a class of nonlinear second order ordinary diferential equations by using the Schauder-Ekhonov fixed point theorem. An application to the existence of bounded positive solutions to certain quasilinear elliptic equations in two-dimensional exterior domains is also given.

Levosimendan is a new agent for the treatment of acute heart failure. Levosimendan acts via complementary mechanisms; it enhances contractility by sensitising cardiac myofilaments to calcium and dilates blood vessels by opening ATP-dependent potassium channels. In contrast to traditional inotropes (beta-agonists or phosphodiesterase inhibitors), levosimendan does not raise myocyte calcium levels a

Aberrations in the G1/S checkpoint are common in malignancies and are probably important for tumor development. Few G1/S studies have been performed on renal cell carcinoma (RCC) and therefore in this study the cyclin D3 protein content in 80 RCCs and that in 12 corresponding normal kidney cortex tissues are characterized using Western blotting. High cyclin D3 protein content was observed in 16% o