Search

Background: Giant cell arteritis (GCA) is a systemic vasculitis that affects especially extra-cerebral cranial arteries, but also extracranial vessels. Ultrasound (US) and MRI support diagnostic procedure, but the gold standard remains the histological analysis of a superficial temporal artery (TA) [for full text, please go to the a.m. URL], 45. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh), 31. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh), 27. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR)

We propose a semiparametric model for regression and classification problems involving multiple response variables. The model makes use of a set of Gaussian processes to model the relationship to the inputs in a nonparametric fashion. Conditional dependencies between the responses can be captured through a linear mixture of the driving processes. This feature becomes important if some of the responses of predictive interest are less densely supplied by observed data than related auxiliary ones. We propose an efficient approximate inference scheme for this semiparametric model whose complexity is linear in the number of training data points.

EGU.European Geosciences Union General Assembly, Vienne, AUT, 17-/04/2016 - 22/04/2016

Sediment transport is an important component of the soil erosion process, which depends on several hydraulic parameters like unit discharge, mean flow velocity, and slope gradient. In most of the previous studies, the impact of these hydraulic parameters on transport capacity was studied for non-erodible bed conditions. Hence, this study aimed to examine the influence of unit discharge, mean flow velocity and slope gradient on sediment transport capacity for erodible beds and also to investigate the relationship between transport capacity and composite force predictors, i.e. shear stress, stream power, unit stream power and effective stream power. In order to accomplish the objectives, experiments were carried out in a 3.0 m long and 0.5 m wide flume using four well sorted sands (0.230, 0.536, 0.719, 1.022 mm). Unit discharges ranging from 0.07 to 2.07 × 10−3 m2 s−1 were simulated inside the flume at four slopes (5.2, 8.7, 13.2 and 17.6%) to analyze their impact on sediment transport rate. The sediment transport rate measured at the bottom end of the flume by taking water and sediment samples was considered equal to sediment transport capacity, because the selected flume length of 3.0 m was found sufficient to reach the transport capacity. The experimental result reveals that the slope gradient has a stronger impact on transport capacity than unit discharge and mean flow velocity due to the fact that the tangential component of gravity force increases with slope gradient. Our results show that unit stream power is an optimal composite force predictor for estimating transport capacity. Stream power and effective stream power can also be successfully related to the transport capacity, however the relations are strongly dependent on grain size. Shear stress showed poor performance, because part of shear stress is dissipated by bed irregularities, bed form evolution and sediment detachment. An empirical transport capacity equation was derived, which illustrates that transport capacity can be predicted from median grain size, total discharge and slope gradient.

A supercritical (SC) nitrogen (N2) switch is designed and tested. The dielectric strength and recovery rate of the SC switch are investigated by experiments. In order to theoretically study the discharge and recovery process of the SC N2 switch under high repetition rate operation, a numerical model is developed. For SC N2 with initial parameters of p = 80.9 bar and T = 300 K, the simulation results show that within several nanoseconds after the streamer bridges the switch gap, the spark is fully developed and this time depends on the applied electric field between electrodes. During the whole discharge process, the maximum temperature in the channel is about 20¿000 K. About 10 µs after the spark excitation of 200 ns duration, the temperature on the axis decays to Taxis = 1500 K, mainly contributed by the gas expansion and heat transfer mechanisms. After 100 µs, the dielectric strength of the gap recovers to above half of the cold breakdown voltage due to the temperature decay in the channel. Both experimental and numerical investigations indicate that supercritical fluid is a good insulating medium that has a proved high breakdown voltage and fast recovery speed.

Hintergrund und Ziele: Im September 2011 gründete die Sektion Kornea der Deutschen Ophthalmologischen Gesellschaft (DOG) das deutsche Akanthamöbenkeratitis-Register. Die Daten dieser multizentrischen Erhebung werden an der Universitätsaugenklinik Homburg/Saar gesammelt und ausgewertet.[for full text, please go to the a.m. URL], 86. Versammlung der Vereinigung Rhein-Mainischer Augenärzte

Terrestrial Laser Scanners (TLS) provide a non-contact method to measure soil microtopography of relatively large surface areas. The appropriateness of the technology in relatation to the derived Digital Elevation Models (DEM) however has not been reported. The suitability of TLS for soil microtopography measurements was tested on-field for three large soil surface areas in agricultural fields. The acquired point clouds were filtered with a custom cloud import algorithm, and converted into digital elevation models (DEM) of different resolutions. To assess DEM quality, point clouds measured from different viewpoints were statistically compared. The statistical fit between point clouds from different viewpoints depends on spatial resolution of the DEM. The best results were obtained at the higher resolutions (0.02 to 0.04¿cm), where less than 5 % of the grid cells showed significant differences between one viewpoint and the next (p¿

Soil erosion is a serious global problem requiring effective modeling for accurate assessment of sensitive areas and related erosion rates. The outcome of soil erosion models depends strongly on the estimation of sediment transport capacity. In most of the existing spatially distributed soil erosion models sediment transport capacity of overland flow is often estimated using stream flow transport capacity functions. The applicability of stream flow functions to overland flow conditions is questionable because hydraulic conditions like flow depth, slope steepness and surface roughness under overland flow are substantially different from stream flow conditions. Hence, the main objectives of this study were i) to check the suitability of five existing well known and widely used transport capacity functions (Yalin 1963; Low, 1989; Govers, 1990; modified Engelund and Hansen (Smith et al., 1995); and Abrahams et al., 2001) for use under overland flow conditions, and ii) to derive a new function based on unit stream power by dimensional analysis to quantify transport capacity for overland flow. To accomplish the objectives, experiments in a 3.0 m long and 0.5 m wide flume were carried out using four different sands (0.230, 0.536, 0.719, and 1.022 mm). The unit discharges used for experimentation ranged from 0.07 to 2.07 x 10(-3) m(2) s(-1) and slopes ranged from 5.2 to 17.6%. In this study, none of the predictions with the existing functions was in good agreement with measured results over the whole range of experimental conditions, especially at low flow intensities. The percentages of observations in which the discrepancy ratio ranged between 0.5 and 2.0 were: 65% (Yalin 1963), 74% (Low, 1989), 57% (Govers, 1990), 54% (modified Engelund and Hansen (Smith et al., 1995)), and 25% (Abrahams et al., 2001). The results showed that the selected functions reasonably estimate transport capacities only under those ranges of conditions for which they were formulated. Although the excess.shear stress concept based function (i.e. Low's function) produced excellent results, the degree of accuracy of the results varied substantially with grain size (P.O.(0.5-2.0): 53-100%). In contrast, the performance of the Govers' function, which is based on the unit stream power concept, was quite similar for all the selected sands (P.O.(0.5-2.0): 50-63%). Based on the unit stream power concept, a new function for low flow intensities was derived by dimensional analysis using the data gained from the flume experiments. (c) 2012 Elsevier B.V. All rights reserved.

Introduction: Genome-wide association studies have mapped loci that are associated with serum levels of bilirubin. Bilirubin is a major component of gallstones, so we investigated whether these variants predict gallstone bilirubin content and overall risk for gallstones. Materials and methods: Loci[for full text, please go to the a.m. URL], 128. Kongress der Deutschen Gesellschaft für Chirurgie

High dopant concentrations are often a prerequisite condition for the realization of semiconductors with new functionalities. For example, magnetic dopants can be used to fabricate ferromagnetic semiconductors (FMS) [1] or intermediate band semiconductors for solar cells [2, 3]. The main problem for processing these materials is the very low solubility of magnetic dopants in elementary and III-V semiconductors. Therefore, thermodynamical non-equilibrium conditions have to be applied to overcome these limits. Thereby, the diffusion path during processing has to be as short as possible to reduce clustering processes which would result in a deactivation of dopants. The diffusion barrier Q of standard shallow donor or acceptor dopants in the solid phase is generally high which results in very low diffusion coefficients. Therefore, during the fast cooling process after PLA, diffusion or hopping of such shallow dopant atoms in recrystallized Si and GaAs has not been considered in detail and no models were developed which quantify interdiffusion processes of dopants for materials with large bulk diffusion barriers Q. However, 3d transition metal dopants in the most important semiconductors have relatively small bulk diffusion barriers Q that result in higher diffusion rates as compared to standard shallow donors. Therefore, the usual assumption that dopants remain fixed on their initial position during PLA processing has to be verified for each type of magnetic dopant in semiconductor spintronics materials. In this work, we perform a Monte Carlo Study on a three-dimensional diffusion model to evaluate the kinetics of initial clustering in a simple cubic host:dopant system. In a second step, the temperature quenching process during PLA was calculated for the materials GaAs and Si and conclusions about diffusion and clustering of typical 3d transition metal dopants can be drawn with respect to the PLA parameters. For Mn in GaAs we also consider declustering effects that have to be included for strongly diffusing dopants like Mn in Si. [1] T. Dietl, H. Ohno, F. Matsukura, J. Cibert, and D. Ferrand, Science 287, 1019 (2000). [2] A. Luque and A. Marti, Phys. Rev. Lett. 78, 5014 (1997). [3] J. Olea, M. Toledano-Luque, D. Pastor, G. Gonzáles-Díaz, and I. Mártil, J. Appl. Phys. 104, 016105 (2008).

The demographics and the growing numbers of people provide a strong signal that the demand for electrical power in Southern Africa will grow considerably over the foreseeable future. Without a steady and increasing supply of electricity development of the continent is likely to be constrained. The inventory of solar, wind, hydrothermal, geothermal and biomass resources will probably provide sources of energy for the future The parallels between extraction of natural resources in the minerals industry and the green energy industry is striking, and the well-established project development process in the minerals industry provides an ideal and useful template for comparing the establishment and development of green energy projects. The potential levels of power generation and carbon savings are described.