University of Mainz

About: University of Mainz is a education organization based out in Mainz, Rheinland-Pfalz, Germany. It is known for research contribution in the topics: Population & Immune system. The organization has 37673 authors who have published 71163 publications receiving 2497880 citations. The organization is also known as: Johannes Gutenberg-Universität Mainz & Universität Mainz.

Pathophysiology, diagnosis and prognostic implications of endothelial dysfunction

Abstract: Endothelial dysfunction (ED) in the setting of cardiovascular risk factors such as hypercholesterolemia, hypertension, diabetes mellitus, chronic smoking as well as in patients with heart failure h...

Flow equation of quantum Einstein gravity in a higher-derivative truncation

Abstract: Motivated by recent evidence indicating that quantum Einstein gravity (QEG) might be nonperturbatively renormalizable, the exact renormalization group equation of QEG is evaluated in a truncation of theory space which generalizes the Einstein-Hilbert truncation by the inclusion of a higher-derivative term ${(R}^{2})$ The beta functions describing the renormalization group flow of the cosmological constant, Newton's constant, and the ${R}^{2}$ coupling are computed explicitly The fixed point properties of the 3-dimensional flow are investigated, and they are confronted with those of the 2-dimensional Einstein-Hilbert flow The non-Gaussian fixed point predicted by the latter is found to generalize to a fixed point on the enlarged theory space In order to test the reliability of the ${R}^{2}$ truncation near this fixed point we analyze the residual scheme dependence of various universal quantities; it turns out to be very weak The two truncations are compared in detail, and their numerical predictions are found to agree with a surprisingly high precision Because of the consistency of the results it appears increasingly unlikely that the non-Gaussian fixed point is an artifact of the truncation If it is present in the exact theory QEG is probably nonperturbatively renormalizable and ``asymptotically safe'' We discuss how the conformal factor problem of Euclidean gravity manifests itself in the exact renormalization group approach and show that, in the ${R}^{2}$ truncation, the investigation of the fixed point is not afflicted with this problem Also the Gaussian fixed point of the Einstein-Hilbert truncation is analyzed; it turns out that it does not generalize to a corresponding fixed point on the enlarged theory space

Surface Cyclones in the ERA-40 Dataset (1958–2001). Part I: Novel Identification Method and Global Climatology

Abstract: A novel method is introduced to generate climatological frequency distributions of meteorological features from gridded datasets. The method is used here to derive a climatology of extratropical cyclones from sea level pressure (SLP) fields. A simple and classical conception of cyclones is adopted where a cyclone is identified as the finite area that surrounds a local SLP minimum and is enclosed by the outermost closed SLP contour. This cyclone identification procedure can be applied to individual time instants, and climatologies of cyclone frequency, fc, are obtained by simple time averaging. Therefore, unlike most other climatologies, the method is not based on the application of a tracking algorithm and considers the size of cyclones. In combination with a conventional cyclone center tracking algorithm that allows the determination of cyclone life times and the location of cyclogenesis and cyclolysis, additional frequency fields can be obtained for special categories of cyclones that are gener...