Münster University of Applied Sciences

About: Münster University of Applied Sciences is a education organization based out in Münster, Germany. It is known for research contribution in the topics: Luminescence & Laser. The organization has 694 authors who have published 1067 publications receiving 12597 citations.

Is prepulse modification altered by continuous theta burst stimulation? DAT1 genotype and motor threshold interact on prepulse modification following brain stimulation

Abstract: Previous studies suggest an inhibitory top-down control of the amygdala by the prefrontal cortex (PFC). Both brain regions play a role in the modulation of prepulse modification (PPM) of the acoustic startle response by a pre-stimulus. Repetitive transcranial magnetic stimulation (rTMS) can modulate the activity of the PFC and might thus affect PPM. This study tested the effect of inhibitory rTMS on PPM accounting for a genetic variant of the dopamine transporter gene (DAT1). Healthy participants (N = 102) were stimulated with continuous theta burst stimulation (cTBS, an intense form of inhibitory rTMS) or sham treatment over the right PFC. Afterwards, during continuous presentation of a background white noise a louder noise burst was presented either alone (control startle) or preceded by a prepulse. Participants were genotyped for a DAT1 variable number tandem repeat (VNTR) polymorphism. Two succeeding sessions of cTBS over the right PFC (2 × 600 stimuli with a time lag of 15 min) attenuated averaged prepulse inhibition (PPI) in participants with a high resting motor threshold. An attenuation of PPI induced by prepulses with great distances to the pulse (480, 2000 ms) was observed following active cTBS in participants that were homozygous carriers of the 10-repeat-allele of the DAT1 genotype and had a high resting motor threshold. Our results confirm the importance of the prefrontal cortex for the modulation of PPM. The effects were observed in participants with a high resting motor threshold only, probably because they received a higher dose of cTBS. The effects in homozygous carriers of the DAT1 10-repeat allele confirm the relevance of dopamine for PPM. Conducting an exploratory study we decided against the use of a correction for multiple testing.

Electronegativity Order of Group IV Elements: Evidence from Molecular Geometry

Abstract: Estimation des electronegatives des elements du groupe IVB (A) a partir des longueurs de liaison observees dans les molecules AX 2 et AX 4 avec X=F, Cl, Br: χ(C)>χ(Ge)>χ(Sn)>χ(Si)

Optical pump concepts for highly efficient quasi-three-level lasers

Abstract: Efficient quasi-three-level laser operation requires the generation of the highest possible pump rate from a given pump source. We derive the fundamental scaling laws for the pump rate and we extract optimization criteria for pump concepts from these laws. The analysis is then applied to the thin-disk laser. Based on the results, a novel pump concept for thin-disk lasers is proposed, which allows for several tens of pump beam passes and reduces the optical complexity of conventional pump concepts. Furthermore, the beam quality of the pump source is preserved almost completely, facilitating the highest possible pump rate.

Efficiency calibration of germanium detectors with internal standards

Abstract: A simple experimental method for the efficiency calibration of germanium detectors especially for environmental samples is presented, using only the natural radionuclides in the sample. The method is based on the fact that for the energy range above 300 keV the full-energy-peak efficiency of a Ge detector can be described in a first order approximation by a linear interpolation curve in the log-log display with errors lying normally under 5%. Photons with different energies which are emitted from one radionuclide yield count rates which are correlated to the corresponding efficiencies. From this correlation one coefficient of the interpolation curve — a first order polynomial — can be calculated. The second coefficient can be obtained by the count rate of40K, resulting from KCl, which is mixed homogeneously with the sample. Expecially for environmental samples with large volumes, this method is very useful, because it takes into account the self-absorption of photons in the sample.