Better fiscal rules for Europe : reflections based on new empirical evidence

Die Fiskalregeln der Eurozone wurden in den letzten fünf Jahren reformiert und erweitert. Ob diese Veränderungen tatsächlich zu einem gesteigerten Maß an fiskalpolitischer Klugheit geführt haben und weitreichend genug waren, ist jedoch unklar. Dieses Grundsatzpapier fasst die jüngsten Forschungsergebnisse eines spanisch-deutsch-amerikanischen Forscherteams unter der Leitung des ZEW zusammen. In der Studie werden die allgemeine Wirksamkeit bisheriger fiskalischer Regelwerke sowie das Zusammenspiel zwischen Regeln, politischen Faktoren und dem Finanzausgleich untersucht. Eine Hauptempfehlung: Die Fiskalpolitik sollte Haushaltsentwicklungen in scheinbar guten Zeiten stärker im Auge behalten und explizit Vorsicht walten lassen bei der Nutzung unerwarteter Mehreinnahmen sowie dem Entstehen umfangreicher Bürokratien

Spin-wave stiffness of the Dzyaloshinskii-Moriya helimagnet compounds Fe1−xCoxSi studied by small-angle neutron scattering

The spin wave stiffness was measured by small-angle neutron scattering method in the Dzyaloshinskii-Moriya helimagnet compounds Fe1−xCoxSi with x=0.25,0.30,0.50. It has been shown that the spin wave dispersion in the fully polarized state is anisotropic due to Dzyaloshinskii-Moriya interaction. It is reflected in the neutron scattering pattern as two circles for neutrons obtaining and losing the magnon energy, respectively. The centers of the circles are shifted by the momentum transfer oriented along the applied magnetic field H and equal to the wave vector of the spiral ±ks. The radius of the circles is directly related to the stiffness of spin waves and depends on the magnetic field. We have found that the spin-wave stiffness A change weakly with temperature for each individual compound. On the other hand, the spin-wave stiffness A increases linearly with x in contrast to the x dependences of the critical temperature Tc and the low-temperature ordered moment. Experimentally obtained values of the stiffness A approve quantitative applicability of the Bak-Jensen model for the compounds under study

How Rainforest Conversion to Agricultural Systems in Sumatra (Indonesia) Affects Active Soil Bacterial Communities

Palm oil production in Indonesia increased constantly over the last decades, which led to massive deforestation, especially on Sumatra island. The ongoing conversion of rainforest to agricultural systems results in high biodiversity loss. Here, we present the first RNA-based study on the effects of rainforest transformation to rubber and oil palm plantations in Indonesia for the active soil bacterial communities. For this purpose, bacterial communities of three different converted systems (jungle rubber, rubber plantation, and oil palm plantation) were studied in two landscapes with rainforest as reference by RT-PCR amplicon-based analysis of 16S rRNA gene transcripts. Active soil bacterial communities were dominated by Frankiales (Actinobacteria), subgroup 2 of the Acidobacteria and Alphaproteobacteria (mainly Rhizobiales and Rhodospirillales). Community composition differed significantly between the converted land use systems and rainforest reference sites. Alphaproteobacteria decreased significantly in oil palm samples compared to rainforest samples. In contrast, relative abundances of taxa within the Acidobacteria increased. Most important abiotic drivers for shaping soil bacterial communities were pH, calcium concentration, base saturation and C:N ratio. Indicator species analysis showed distinct association patterns for the analyzed land use systems. Nitrogen-fixing taxa including members of Rhizobiales and Rhodospirillales were associated with rainforest soils while nitrifiers and heat-resistant taxa including members of Actinobacteria were associated with oil palm soils. Predicted metabolic profiles revealed that the relative abundances of genes associated with fixation of nitrogen significantly decreased in plantation soils. Furthermore, predicted gene abundances regarding motility, competition or gene transfer ability indicated rainforest conversion-induced changes as well

Searches at HERA for Squarks in R-Parity Violating Supersymmetry

A search for squarks in R-parity violating supersymmetry is performed in e^+p collisions at HERA at a centre of mass energy of 300 GeV, using H1 data corresponding to an integrated luminosity of 37 pb^(-1). The direct production of single squarks of any generation in positron-quark fusion via a Yukawa coupling lambda' is considered, taking into account R-parity violating and conserving decays of the squarks. No significant deviation from the Standard Model expectation is found. The results are interpreted in terms of constraints within the Minimal Supersymmetric Standard Model (MSSM), the constrained MSSM and the minimal Supergravity model, and their sensitivity to the model parameters is studied in detail. For a Yukawa coupling of electromagnetic strength, squark masses below 260 GeV are excluded at 95% confidence level in a large part of the parameter space. For a 100 times smaller coupling strength masses up to 182 GeV are excluded.Comment: 32 pages, 14 figures, 3 table