An ancient compound rediscovered: perspectives of aphid control in organic hop growing by the use of quassia products

In the first three decades of the 20th century, quassia extract was widely used in hop growing as a chemical agent to control Phorodon humuli and other insect pests. In the first years of the 21st century this compound was rediscovered by German organic hop growers. In nine efficacy trials conducted in five field seasons, quassia products proved to be effective control agents for P. humuli in organically grown aroma cultivars. As the best method of application a systemic variant was developed by painting a suspension of quassia extract to the bines. This method proved not only to be very effective but was also best from an environmental point of view as sprayed quassia extracts had side effects on non-target organisms. As an optimal systemic application rate 24 g/ha of the active ingredient quassine was determined

Analyzing genome-wide association studies with an FDR controlling modification of the Bayesian information criterion

The prevailing method of analyzing GWAS data is still to test each marker individually, although from a statistical point of view it is quite obvious that in case of complex traits such single marker tests are not ideal. Recently several model selection approaches for GWAS have been suggested, most of them based on LASSO-type procedures. Here we will discuss an alternative model selection approach which is based on a modification of the Bayesian Information Criterion (mBIC2) which was previously shown to have certain asymptotic optimality properties in terms of minimizing the misclassification error. Heuristic search strategies are introduced which attempt to find the model which minimizes mBIC2, and which are efficient enough to allow the analysis of GWAS data. Our approach is implemented in a software package called MOSGWA. Its performance in case control GWAS is compared with the two algorithms HLASSO and GWASelect, as well as with single marker tests, where we performed a simulation study based on real SNP data from the POPRES sample. Our results show that MOSGWA performs slightly better than HLASSO, whereas according to our simulations GWASelect does not control the type I error when used to automatically determine the number of important SNPs. We also reanalyze the GWAS data from the Wellcome Trust Case-Control Consortium (WTCCC) and compare the findings of the different procedures

Cooperative Simultaneous Localization and Synchronization in Mobile Agent Networks

Cooperative localization in agent networks based on interagent time-of-flight measurements is closely related to synchronization. To leverage this relation, we propose a Bayesian factor graph framework for cooperative simultaneous localization and synchronization (CoSLAS). This framework is suited to mobile agents and time-varying local clock parameters. Building on the CoSLAS factor graph, we develop a distributed (decentralized) belief propagation algorithm for CoSLAS in the practically important case of an affine clock model and asymmetric time stamping. Our algorithm allows for real-time operation and is suitable for a time-varying network connectivity. To achieve high accuracy at reduced complexity and communication cost, the algorithm combines particle implementations with parametric message representations and takes advantage of a conditional independence property. Simulation results demonstrate the good performance of the proposed algorithm in a challenging scenario with time-varying network connectivity.Comment: 13 pages, 6 figures, 3 tables; manuscript submitted to IEEE Transaction on Signal Processin

Bekämpfung von Blattläusen und Peronospora im Ökologischen Hopfenbau

In den Jahren 2004 bis 2006 wurden in einem Forschungsprojekt Alternativen zur An-wendung kupfer- und schwefelhaltiger Pflanzenschutzmittel im Ökologischen Hofenbau gesucht. Besonderes Augenmerk galt dabei der Peronospora (Falscher Mehltau), die bis dato nur mit kupferhaltigen Produkten effektiv kontrolliert werden kann, sowie der Hop-fenblattlaus. Zur Bekämpfung der Peronospora wurden insgesamt zehn Produkte oder Varianten zum Teil über drei Saisons geprüft. Als Fazit der Versuche konnte kein kupfer-freies Produkt gefunden werden, das auch nur annähernd die Peronospora im Hopfen be-kämpfen kann, da diese ohne Ausschaltung der Primärinfektion mit rein biologischen Pro-dukten nicht effektiv kontrolliert werden kann. Kupferhydroxidhaltige Niedrigkupfer-Produkte müssen in der Aufwandmenge noch angepasst werden. Bei der Bekämpfung der Hopfenblattlaus bestätigte sich, dass Quassia-Extrakt im Spritz-verfahren sehr gute Wirkung hat. Als wesentlich umweltfreundlichere Variante des Quas-sia-Einsatzes wurde allerdings der systemische Einsatz des industriell hergestellten Pro-duktes „TRF-002“ im Streichverfahren überprüft und für gut befunden. Die optimale Wirkstoffmenge beträgt dabei 24 g/ha Quassin. Alle übrigen getesteten Wirkstoffe konn-ten nicht überzeugen

Neutrino signature of supernova hydrodynamical instabilities in three dimensions

The first full-scale three-dimensional (3D) core-collapse supernova (SN) simulations with sophisticated neutrino transport show pronounced effects of the standing accretion shock instability (SASI) for two high-mass progenitors (20 and 27 M_sun). In a low-mass progenitor (11.2 M_sun), large-scale convection is the dominant nonradial hydrodynamic instability in the postshock accretion layer. The SASI-associated modulation of the neutrino signal (80 Hz in our two examples) will be clearly detectable in IceCube or the future Hyper-Kamiokande detector, depending on progenitor properties, distance, and observer location relative to the main SASI sloshing direction. The neutrino signal from the next galactic SN can therefore diagnose the nature of the hydrodynamic instability.Comment: 6 pages, including 4 figures. Results unchanged. Matches published version in PRL. Animated visualization available at: http://www.mpa-garching.mpg.de/ccsnarchive/data/Hanke2013_movie/index.htm