1,712 research outputs found

    A broader perspective on three lifespan theories: Comment on Boerner and Jopp

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    Using Cloud Services in a Modern Learning Management System

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    LMS (Learning Management Systems) today are being widely used in almost every educational facility. In the last years all conceivable use cases that need to be carried out by such LMS have been defined and the features a modern LMS needs to offer are very clear. Rarely do we find something a teacher or student needs that an LMS cannot offer. So the task for LMS developers shifted from offering all tools a teacher or student needs to make these tools as convenient to use as possible. Our goal in this research work is to describe the web services we use in TeachCenter, an LMS that has been widely used for the past years at Graz University of Technology to simplify the use of certain components. It can be pointed out that cloud services have to be an integral part of a modern LMS

    Testing normality in any dimension by Fourier methods in a multivariate Stein equation

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    We study a novel class of affine-invariant and consistent tests for multivariate normality. The tests are based on a characterization of the standard d-variate normal distribution by way of the unique solution of an initial value problem connected to a partial differential equation, which is motivated by a multivariate Stein equation. The test criterion is a suitably weighted L2-statistic. We derive the limit distribution of the test statistic under the null hypothesis as well as under contiguous and fixed alternatives to normality. A consistent estimator of the limiting variance under fixed alternatives, as well as an asymptotic confidence interval of the distance of an underlying alternative with respect to the multivariate normal law, is derived. In simulation studies, we show that the tests are strong in comparison with prominent competitors and that the empirical coverage rate of the asymptotic confidence interval converges to the nominal level. We present a real data example and also outline topics for further research

    Anisotropy in the helicity modulus of a 3D XY-model: application to YBCO

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    We present a Monte Carlo study of the helicity moduli of an anisotropic classical three-dimensional (3D) XY-model of YBCO in superconducting state. It is found that both the ab-plane and the c-axis helicity moduli, which are proportional to the inverse square of the corresponding magnetic field penetration depth, vary linearly with temperature at low temperatures. The result for the c-axis helicity modulus is in disagreement with the experiments on high quality samples of YBCO. Thus we conclude that purely classical phase fluctuations of the superconducting order parameter cannot account for the observed c-axis electrodynamics of YBCO.Comment: 7 pages, 1 figur

    Molecular and immunological characterization of profilin from mugwort pollen

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    In late summer in Europe, pollen of mugwort is one of the major sources of atopic allergens. No information about the complete molecular structure of any mugwort allergen has been published so far. Here we report the isolation and characterization of mugwort pollen cDNA clones coding for two isoforms of the panallergen profilin. Thirtysix percent of the mugwort allergic patients tested displayed IgE antibodies against natural and recombinant profilin, and no significant differences were observed in the IgEbinding properties of the isoforms. One profilin isoform was purified to homogeneity and detailed structural analysis indicated that the protein exists in solution as dimers and tetramers stabilized by sulfydryl and/or ionic interactions. Profilin monomers were detectable only after exposure of multimers to harsh denaturing conditions. Dimers and tetramers did not significantly differ in their ability to bind serum IgE from mugwort pollenallergic patients. However, oligomeric forms might have a higher allergenic potential than monomers because larger molecules would have additional epitopes for IgEmediated histamine release. Profilin isolated from mugwort pollen also formed multimers. Thus, oligomerization is not an artifact resulting from the recombinant production of the allergen. Inhibition experiments showed extensive IgE crossreactivity of recombinant mugwort profilin and profilin from various pollen and food extracts

    Platelet transfusion can mimic somatic mtDNA mutations

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