Wiebe D. de Boer

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The use of genetically modified (GM) plants in agriculture has been a topic in public debate for over a decade. Despite their potential to increase yields, there may be unintended negative side-effects of GM plants on soil micro-organisms that are essential for functioning of agro-ecosystems. Fungi are important soil organisms and can have beneficial or(More)
The public data from the EGRET space telescope on diffuse Galactic gamma rays in the energy range from 0.1 to 10 GeV are reanalyzed with the purpose of searching for signals of Dark Matter annihilation (DMA). The analysis confirms the previously observed excess for energies above 1 GeV in comparison with the expectations from conventional Galactic models.(More)
In speed skating, performance is related to the product of the amount of work per stroke and the stroke frequency. Work per stroke is dependent on the component of the push-off force in the direction perpendicular to the gliding direction of the skate. The push-off force at different velocities was measured in three trained speed skaters. The results showed(More)
A CMOS compatible Ge avalanche photodiode is fabricated on Si by using a selective chemical-vapor deposition (CVD) epitaxial growth technique. At a temperature of 700˚C, single crystal islands of As-doped Ge are grown in windows to the Si with sizes up to hundreds of μm 2 , to a layer thickness of approximately 1 µm, This is followed by a pure Ga and then a(More)
Within the Constrained Minimal Supersymmetric Standard Model (CMSSM) it is possible to predict the low energy gauge couplings and masses of the 3. generation particles from a few parameters at the GUT scale. In addition the MSSM predicts electroweak symmetry breaking due to large radiative corrections from Yukawa couplings, thus relating the Z 0 boson mass(More)
Recently it was shown that the excess of diffuse Galactic gamma rays above 1 GeV traces the Dark Matter halo, as proven by reconstructing the peculiar shape of the rotation curve of our Galaxy from the gamma ray excess. This can be interpreted as a Dark Matter annihilation signal. In this paper we investigate if this interpretation is consistent with(More)
Single-Crystal CVD-Diamond Detectors (SC-DD) of ~ 300μm thickness have been tested in Cave A with proton beams of E p > 1AGeV as start detectors for minimum ionizing particles. Fast charge-sensitive amplifiers developed at GSI and Bucharest were used. At particle rates up to 1MHz, stable operation and detection efficiency of ~100% are observed. The measured(More)