Ertragsentwicklung langjährig viehlos bewirtschafteter Öko- Ackerflächen am Oberrhein

The evaluation of data from arable land in the southern part of upper Rhine valley that has been cultivated in organic agriculture without livestock since 1972 showed decreasing soil-contents of plant available P and K despite of positive fertilizer balances as well as decreasing yields of cereals on sites of lower quality. Only on a profound soil with a high level of organic substance this trend was not as marked; with autumn rye and soybeans there the yield trend was even positive (see figure 1)

Make life simple: unleash the full power of the parallel tempering algorithm

We introduce a new update scheme to systematically improve the efficiency of parallel tempering simulations. We show that by adapting the number of sweeps between replica exchanges to the canonical autocorrelation time, the average round-trip time of a replica in temperature space can be significantly decreased. The temperatures are not dynamically adjusted as in previous attempts but chosen to yield a 50% exchange rate of adjacent replicas. We illustrate the new algorithm with results for the Ising model in two and the Edwards-Anderson Ising spin glass in three dimensionsComment: 4 pages, 5 figure

Gute Chancen für den Öko-Sojaanbau in Deutschland

From 2011 to 2013 a total of 35 different soybean cultivars were tested in organically managed replicated trials under a wide range of pedo-climatic conditions in Germany. The resulting yields were affected by the climatic region, soybean maturity group, water availability during grain filling and soybean cultivar. From our results we can conclude that with current cultivars a successful soybean cropping in most parts of Germany is possible. Only in the cooler regions of northern Germany and in the uplands yields are usually not competitive with other crops

Football fever: goal distributions and non-Gaussian statistics

Analyzing football score data with statistical techniques, we investigate how the not purely random, but highly co-operative nature of the game is reflected in averaged properties such as the probability distributions of scored goals for the home and away teams. As it turns out, especially the tails of the distributions are not well described by the Poissonian or binomial model resulting from the assumption of uncorrelated random events. Instead, a good effective description of the data is provided by less basic distributions such as the negative binomial one or the probability densities of extreme value statistics. To understand this behavior from a microscopical point of view, however, no waiting time problem or extremal process need be invoked. Instead, modifying the Bernoulli random process underlying the Poissonian model to include a simple component of self-affirmation seems to describe the data surprisingly well and allows to understand the observed deviation from Gaussian statistics. The phenomenological distributions used before can be understood as special cases within this framework. We analyzed historical football score data from many leagues in Europe as well as from international tournaments, including data from all past tournaments of the “FIFA World Cup” series, and found the proposed models to be applicable rather universally. In particular, here we analyze the results of the German women's premier football league and consider the two separate German men's premier leagues in the East and West during the cold war times as well as the unified league after 1990 to see how scoring in football and the component of self-affirmation depend on cultural and political circumstances

Universality of the evaporation/condensation transition

AbstractBy making use of the well-known lattice-gas interpretation, we investigated the evaporation/condensation transition through Monte Carlo simulations of the square lattice Ising model with nearest-neighbour couplings and periodic boundary conditions. The particle density can be varied by choosing different fixed magnetisations. In the analysis of our data we followed recent analytical work by Biskup et al. [Europhys. Lett. 60 (2002) 21], who also used the Ising model to study liquid-vapour systems at a fixed excess δN of particles above the ambient gas density in the limit of large system sizes. By identifying a dimensionless parameter Δ(δN), they showed that for Δ<Δc all excess is absorbed in background fluctuations (“evaporated” system), while for Δ>Δc a single large droplet of the dense phase occurs (“condensed” system). Besides the threshold value Δc also the fraction λ of excess particles forming the droplet is given explicitly.To test the applicability of these asymptotic results to practically accessible system sizes, we measured the volume of the largest minority droplet, corresponding to a fluid drop, for various L×L lattices with L=40,…,640. Using analytic values for the spontaneous magnetisation m0, the susceptibility χ and the Wulff interfacial free-energy density τW for the infinite system, we were able to determine Δc and λ numerically in very good agreement with the theoretical prediction. We also discuss the associated free-energy barrier and its implication for multimagnetical simulations, and put these findings into context with the related droplet/strip transition respectively barrier

Entwicklung und Evolution dienstorientierter Anwendungen im Web Engineering

Die vorliegende Abhandlung untersucht die methodische und systematische Herangehensweise an die Entwicklung dienstorientierter Anwendungen im Web Engineering. Dabei wird deren architekturelle Betrachtung in den Vordergrund gerückt, die auf der Grundlage autonomer, wiederverwendbarer Komponenten in Form von Web Services basiert. Dazu werden dedizierte Modelle, Methoden und Werkzeuge entlang dieser - an Web-Standards orientierten - Architektur entwickelt

Feto-fetales Transfusionssyndrom : Kardiale <em>Follow-Up-</em>Studie bei Zwillingen 17 Jahre nach intrauteriner Therapie

Hintergrund: Das feto-fetale Transfusionssyndrom (FFTS) ist eine schwere Erkrankung von monochorial-diamnioten Zwillingsschwangerschaften, bei welcher genetisch identische Zwillinge ganz unterschiedlichen intrauterinen kardiovaskulären Belastungen ausgesetzt sind. Das FFTS kann zu relevanten fetalen und postnatalen Unterschieden in der kardiovaskulären Funktion von Donatoren und Akzeptoren führen. Fragestellung: Ziel der Studie war es herauszufinden, ob Unterschiede in der kardiovaskulären Funktion zwischen den ehemaligen Akzeptoren und Donatoren im frühen Erwachsenenalter, trotz intrauteriner Therapie, fortbestehen. Zudem sollte überprüft werden, ob intrauterine kardiovaskuläre Belastungen Ursache für kardiovaskuläre Risiken im Erwachsenenalter sein können (Barker-Hypothese). Methode: In dieser Pilotstudie wurden 12 Zwillingspaare – acht nach Laser- und vier nach Amniozentesetherapie – im mittleren Alter von 17 (16-19) Jahren mit detaillierter Echokardiographie, Kardio-MRT (inklusive Strain-Analyse) sowie Blutdruck- und Pulswellenanalyse untersucht. Ergebnis: Es zeigten sich keine signifikanten Unterschiede zwischen den Donatoren und Akzeptoren im M-Mode, Fluss-Doppler, Herzvolumen, Ejektionsfraktion, Blutdruck und in der Gefäßsteifigkeit. In der Strain-Analyse zeigten sich ventrikelspezifische Unterschiede: im Feature Tracking Imaging (MRT) zeigten die Akzeptoren eine reduzierte systolische RV-Funktion (RV Longitudinaler Strain (LS); p Fazit: Trotz der fetal unterschiedlichen kardiovaskulären Belastungen zeigten sich bei dem Studienkollektiv im Alter von 17 Jahren nur subtile Unterschiede in der Herzfunktion zwischen den ehemaligen Donatoren und Akzeptoren. Dies spricht für ein gutes kardiovaskuläres Langzeit-Outcome des FFTS

Critical mass and the dependency of research quality on group size

Academic research groups are treated as complex systems and their cooperative behaviour is analysed from a mathematical and statistical viewpoint. Contrary to the naive expectation that the quality of a research group is simply given by the mean calibre of its individual scientists, we show that intra-group interactions play a dominant role. Our model manifests phenomena akin to phase transitions which are brought about by these interactions, and which facilitate the quantification of the notion of critical mass for research groups. We present these critical masses for many academic areas. A consequence of our analysis is that overall research performance of a given discipline is improved by supporting medium-sized groups over large ones, while small groups must strive to achieve critical mass.Comment: 16 pages, 6 figures consisting of 16 panels. Presentation and reference list improved for version

Monte Carlo study of the evaporation/condensation transition on different Ising lattices

In 2002 Biskup et al. [Europhys. Lett. 60, 21 (2002)] sketched a rigorous proof for the behavior of the 2D Ising lattice gas, at a finite volume and a fixed excess \delta M of particles (spins) above the ambient gas density (spontaneous magnetisation). By identifying a dimensionless parameter \Delta (\delta M) and a universal constant \Delta_c, they showed in the limit of large system sizes that for \Delta < \Delta_c the excess is absorbed in the background (``evaporated'' system), while for \Delta > \Delta_c a droplet of the dense phase occurs (``condensed'' system). To check the applicability of the analytical results to much smaller, practically accessible system sizes, we performed several Monte Carlo simulations for the 2D Ising model with nearest-neighbour couplings on a square lattice at fixed magnetisation M. Thereby, we measured the largest minority droplet, corresponding to the condensed phase, at various system sizes (L=40, >..., 640). With analytic values for for the spontaneous magnetisation m_0, the susceptibility \chi and the Wulff interfacial free energy density \tau_W for the infinite system, we were able to determine \lambda numerically in very good agreement with the theoretical prediction. Furthermore, we did simulations for the spin-1/2 Ising model on a triangular lattice and with next-nearest-neighbour couplings on a square lattice. Again, finding a very good agreement with the analytic formula, we demonstrate the universal aspects of the theory with respect to the underlying lattice. For the case of the next-nearest-neighbour model, where \tau_W is unknown analytically, we present different methods to obtain it numerically by fitting to the distribution of the magnetisation density P(m).Comment: 14 pages, 17 figures, 1 tabl