Prevention of vole damage in organic pomiculture

Vole damage is one of the most difficult phytosanitary problems to solve in organic pomiculture. A survey conducted in 2002 among German fruit growers showed that 90 % of the farms suffered from this damage. The water vole (A. terrestris) revealed to be the main pest in 80 % of the orchards. 61 % of the farmers announced a high interest in the development of new preventive and control methods. To stop immigration of voles into orchards a mechanical barrier system was developed and tested at two study sites in Baden-Wuerttemberg and Rhineland-Palatinate. At each location barrier systems with wire mesh (mesh size 10 mm) and polyolefine-foil were installed arround two 0.7 ha study plots. Two unprotected plots were used as a control. The barriers were anchored 20 cm deep into the soil. 30 cm of the material protruded over the surface. Automatic gates were installed for the entrance of vehicles. 4 persons needed approximately one day to install a barrier around a plot with the size of 1 ha. Not only was the wire mesh cheaper than the foil, it was permeable for wind, water and small beneficial organisms. After installing the barrier systems, voles were removed from all plots. Snap trap boxes were ranged along the outside of the barriers to catch migrating voles. A total of 33 water voles and 1263 common voles (M. arvalis) were captured on both study sites from October 2002 to November 2003. During the study period a total of 5 water voles immigrated into the first control plot and 6 settled into the other plot. Four water voles entered two of the barrier protected plots by using fresh mole galleries. The other protected plots stayed free from water voles. Simultaneous to the field studies, trials in two enclosures were carried out in Muenster. The barriers kept all water voles outside the protected plots. The results showed a high efficacy of the developed barrier system

How expensive is vole damage?

Vole species, especially Arvicola terrestris and Microtus arvalis cause significant economical damage in organic pomiculture by gnawing the root system of trees. The importance of voles as pest organisms is well known. Nevertheless, the estimation of financial loss caused by voles is difficult for German fruit growers. We conducted a survey among organic fruit growers to get data on kind and amount of annual damage. Using the available publications and official statistics we calculated economical values of organic apple trees for different types of orchard processing and tree ages. Furthermore we calculated the number of trees lost due to voles in one year

Will the valuation ratios revert to their historical means? Some evidence from breakpoint tests

If valuation ratios return to their historical means any time soon, then equity prices must fall substantially, or earnings and dividends must accelerate sharply, or some combination of these events must occur. Historical patterns over the past century suggest that stock prices will fall to align valuation ratios with their means. Of course, the means of the valuation ratios could have changed. To assess the likelihood of such changes, the authors employ breakpoint tests, which allow for multiple breakpoints at unknown break dates. The authors also review alternative explanations for changes in the ratios. They conclude that although no single explanation may be convincing by itself, taken in toto with empirical evidence of structural change, the preponderance of evidence suggests that the mean of the dividend-price ratio is now somewhere between 1% and 2%, probably nearer to 1%. They also conclude that the mean price-to-earnings ratio is now somewhere between 20 and 25, perhaps even higher.Stock - Prices

Mutual funds, fee transparency, and competition

Mutual funds enable small, less experienced investors to hold diversified portfolios of stocks and bonds at relatively low costs. Though the mutual fund market is competitive in many ways, fees can vary substantially for what are essentially identical products. This may be due to bundling of services, but it may also reflect some confusion on the part of less experienced investors, which inhibits comparative shopping among funds. Suggested reforms for improved fee disclosure seek to make fees more transparent for less informed investors and should improve competitive discipline among funds.Mutual funds

Abwehr von Wühlmausschäden im ökologischen Obstbau mit Hilfe von Migrationsbarrieren

Sowohl im integrierten als auch im ökologischen Obstbau gelingt eine dauerhafte Abwehr von Wühlmausschäden mit den zur Verfügung stehenden Mitteln nur unzureichend. Nach den Ergebnissen einer Umfrage, für die 279 Rückmeldungen ausgewertet wurden, sind 90 % der deutschen Obstbaubetriebe von Wühlmausschäden betroffen. Hauptschadensverursacher ist die Schermaus (Arvicola terrestris), die für Schäden auf 80 % der Flächen verantwortlich gemacht wird

Abwehr von Wühlmausschäden im ökologischen Obstbau

Wühlmausschäden sind weit verbreitet und gehören zu den nur schwer lösbaren Pflanzenschutzproblemen im ökologischen Landbau. Nach einer Umfrage des Institutes für Nematologie und Wirbeltierkunde der Biologischen Bundesanstalt für Land- und Forstwirtschaft (BBA), im Jahre 2002 waren 90 % der befragten Obstbaubetriebe von Wühlmausschäden betroffen. Als Hauptschadensverursacher treten vor allem die Schermaus (Arvicola terrestris ), auch große Wühlmaus genannt, und die Feldmaus ( Microtus arvalis) auf. Mit den wenigen zur Verfügung stehenden Mitteln erreicht aber nur ein Bruchteil der ökologisch wirtschaftenden Betriebe einen akzeptablen Bekämpfungserfolg. Von Wissenschaft und Industrie werden viele Anstrengungen unternommen, um bekannte Abwehrmaßnahmen zu verbessern und neue Präparate sowie Methoden zu entwickeln. Dazu werden die Lebensweise und in letzter Zeit vor allem das sehr komplexe Verhalten von Wühlmäusen intensiv untersucht. In diesem Merkblatt werden die derzeit möglichen und angewandten Bekämpfungs- und Abwehrmaßnahmen für den ökologischen Obstbau sowie deren Erfolgsaussichten vorgestellt. Verschiedene Hinweise sollen helfen, die Wühlmausabwehr effizienter zu gestalten. Das Merkblatt richtet sich in erster Linie an Obstbauern und Obstbauberater. Aber auch Baumschulbetriebe, Gemüsebauern, kommunale Einrichtungen und Gartenbesitzer werden Anregungen für die Lösung von Wühlmausproblemen finden

Magneto-Optical Spectrum Analyzer

We present a method for the investigation of gigahertz magnetization dynamics of single magnetic nano elements. By combining a frequency domain approach with a micro focus Kerr effect detection, a high sensitivity to magnetization dynamics with submicron spatial resolution is achieved. It allows spectra of single nanostructures to be recorded. Results on the uniform precession in soft magnetic platelets are presented.Comment: 5 pages, 7 figure

The cell adhesion molecule BT-IgSF is essential for a functional blood-testis barrier and male fertility in mice

The Ig-like cell adhesion molecule (IgCAM) brain- and testis-specific immunoglobulin superfamily (BT-IgSF) protein plays a major role in male fertility in mice. However, the molecular mechanism by which BT-IgSF supports fertility is unclear. Here, we found that it is localized in Sertoli cells at the blood-testis barrier (BTB) and at the apical ectoplasmic specialization. Absence of BT-IgSF in Sertoli cells in both global and conditional mouse mutants (i.e. AMHCre and Rosa26CreERT2 lines) resulted in male infertility, atrophic testes with vacuolation, azoospermia, and spermatogenesis arrest. Although transcripts of junctional proteins such as connexin43, ZO-1, occludin, and claudin11 were upregulated in the absence of BT-IgSF, the functional integrity of the BTB was impaired, as revealed by injection of a BTB-impermeable component into the testes under in vivo conditions. Disruption of the BTB coincided with mislocalization of connexin43, which was present throughout the seminiferous epithelium and not restricted to the BTB as in wildtype tissues, suggesting impaired cell-cell communication in the BT-IgSF-KO mice. Since EM images revealed a normal BTB structure between Sertoli cells in the BT-IgSF-KO mice, we conclude that infertility in these mice is most likely caused by a functionally impaired BTB. In summary, our results indicate that BT-IgSF is expressed at the BTB and is required for male fertility by supporting the functional integrity of the BTB

Motion tracking of iris features to detect small eye movements

The inability of current video-based eye trackers to reliably detect very small eye movements has led to confusion about the prevalence or even the existence of monocular microsaccades (small, rapid eye movements that occur in only one eye at a time). As current methods often rely on precisely localizing the pupil and/or corneal reflection on successive frames, current microsaccade-detection algorithms often suffer from signal artifacts and a low signal-to-noise ratio. We describe a new video-based eye tracking methodology which can reliably detect small eye movements over 0.2 degrees (12 arcmin) with very high confidence. Our method tracks the motion of iris features to estimate velocity rather than position, yielding a better record of microsaccades. We provide a more robust, detailed record of miniature eye movements by relying on more stable, higher-order features (such as local features of iris texture) instead of lower-order features (such as pupil center and corneal reflection), which are sensitive to noise and drift

Stochastic Methods for Aircraft Design

The global stochastic optimization method, simulated annealing (SA), was adapted and applied to various problems in aircraft design. The research was aimed at overcoming the problem of finding an optimal design in a space with multiple minima and roughness ubiquitous to numerically generated nonlinear objective functions. SA was modified to reduce the number of objective function evaluations for an optimal design, historically the main criticism of stochastic methods. SA was applied to many CFD/MDO problems including: low sonic-boom bodies, minimum drag on supersonic fore-bodies, minimum drag on supersonic aeroelastic fore-bodies, minimum drag on HSCT aeroelastic wings, FLOPS preliminary design code, another preliminary aircraft design study with vortex lattice aerodynamics, HSR complete aircraft aerodynamics. In every case, SA provided a simple, robust and reliable optimization method which found optimal designs in order 100 objective function evaluations. Perhaps most importantly, from this academic/industrial project, technology has been successfully transferred; this method is the method of choice for optimization problems at Northrop Grumman