Behandlungsstrategien bei Befall mit Echtem und Falschem Mehltau an Arznei- und Gewürzpflanzen im ökologischen Anbau am Beispiel von Blütendrogen, Blattdrogen, Krautdrogen und Körnerdrogen

Laufzeit des BOEL-Projektes (FKZ: 02OE144): Mai 2002 bis Oktober 2003 Ziel des Projektes ist die Einführung praxistauglicher Strategien zur Mehltauregulierung an Arznei- und Gewürzpflanzen im ökologischen Anbau. Die Übertragung von Strategien und Erfahrungen aus anderen Sparten auf die Arznei- und Gewürzpflanzen sollen im Feldversuch geprüft werden, die Schaderreger charakterisiert und in ihrer Biologie beschrieben werden. Ferner wird an der Optimierung der Anbaubedingungen gearbeitet. Geprüft werden Pflanzenschutz- und Pflanzenstärkungsmittel sowie pflanzenbauliche Maßnahmen (Düngung. Bestandesdichte) an vier beispielhaften Kulturen (Anis, Apfelminze, Weidenröschen und Ringelblume)

High Velocity Dust Collisions: Forming Planetesimals in a Fragmentation Cascade with Final Accretion

In laboratory experiments we determine the mass gain and loss in central collisions between cm to dm-size SiO2 dust targets and sub-mm to cm-size SiO2 dust projectiles of varying mass, size, shape, and at different collision velocities up to ~56.5 m/s. Dust projectiles much larger than 1 mm lead to a small amount of erosion of the target but decimetre targets do not break up. Collisions produce ejecta which are smaller than the incoming projectile. Projectiles smaller than 1 mm are accreted by a target even at the highest collision velocities. This implies that net accretion of decimetre and larger bodies is possible. Independent of the original size of a projectile considered, after several collisions all fragments will be of sub-mm size which might then be (re)-accreted in the next collision with a larger body. The experimental data suggest that collisional growth through fragmentation and reaccretion is a viable mechanism to form planetesimals

Kindererziehung im alternativen Projekt

In dem vorliegenden Beitrag wird ein praktisches Beispiel für eine alternative strukturelle Erziehung gegeben. (DIPF/Orig.

”Alternative” im Dorf - haben wir voneinander gelernt? Erfahrungen aus drei Jahren Leben im Dorf

Die Autorin und der Autor dieses Beitrags, die gemeinsam mit ihren Kindern Reutlingen verließen, um in Obermusbach ein neues ländliches Leben und Arbeiten zu beginnen, berichten wie und wie weit eine Annäherung, ein gegenseitiges Lernen zwischen ihnen und den Menschen im Dorf möglich geworden ist. (DIPF/Orig.

Seebeck coefficients of half-metallic ferromagnets

In this report the Co2 based Heusler compounds are discussed as potential materials for spin voltage generation. The compounds were synthesized by arcmelting and consequent annealing. Band structure calculations were performed and revealed the compounds to be half-metallic ferromagnets. Magnetometry was performed on the samples and the Curie temperatures and the magnetic moments were determined. The Seebeck coefficients were measured from low to ambient temperatures for all compounds. For selected compounds high temperature measurements up to 900 K were performed.Comment: accepted contribution o the Special Issue "Spin Caloritronics" of Solid State Communication

Breaking the Ice: Planetesimal Formation at the Snowline

Recently Saito & Sirono (2011) proposed that large ice aggregates which drift in- wards in protoplanetary disks break up during sublimation, ejecting embedded silicate particles. This would lead to a concentration of small solid particles close to the snow- line. In view of this model we carried out laboratory experiments where we observed freely levitating ice aggregates sublimating. We find that frequent break up is indeed very common. Scaled to a 10 cm aggregate about 2x10^4 small silicate aggregates might result. This supports the idea that sublimation of drifting ice aggregates might locally increase the density of small dust (silicate) particles which might more easily be swept up by larger dust aggregates or trigger gravitational instability. Either way this might locally boost the formation of planetesimals at the snowline.Comment: 6 pages, 9 figure

The nature of the Galactic Center source IRS 13 revealed by high spatial resolution in the infrared

High spatial resolution observations in the 1 to 3.5 micron region of the Galactic Center source known historically as IRS 13 are presented. They include ground-based adaptive optics images in the H, Kp (2.12/0.4 micron) and L bands, NICMOS data in filters between 1.1 and 2.2 micron, and integral field spectroscopic data from BEAR, an Imaging FTS, in the HeI 2.06 micron and the Br$\gamma$ line regions. Analysis of all these data provides a completely new picture of the main component, IRS 13E, which appears as a cluster of seven individual stars within a projected diameter of ~0.5'' (0.02 pc). The brightest sources, 13E1, 13E2, 13E3 (a binary), and 13E4, are all massive stars, 13E1 a blue object, with no detected emission line while 13E2 and 13E4 are high-mass emission line stars. 13E2 is at the WR stage and 13E4 a massive O-type star. 13E3A and B are extremely red objects, proposed as other examples of dusty WR stars. All these sources have a common westward proper motion. 13E5, is a red source similar to 13E3A/B. This concentration of comoving massive hot stars, IRS 13E, is proposed as the remaining core of a massive star cluster, which could harbor an intermediate-mass black hole (IMBH) of ~1300 M_sol. This detection plays in favor of a scenario in which the helium stars and the other hot stars in the central pc originate from the stripping of a massive cluster formed several tens of pc from the center. The detection of a discrete X-ray emission (Baganoff et al. 2003) at the IRS~13 position is examined in this context.Comment: 14 pages, 6 figures (3 in color), LaTeX2e, accepted in A&