AstraLux: the Calar Alto Lucky Imaging Camera

AstraLux is the Lucky Imaging camera for the Calar Alto 2.2-m telescope, based on an electron-multiplying high speed CCD. By selecting only the best 1-10% of several thousand short exposure frames, AstraLux provides nearly diffraction limited imaging capabilities in the SDSS i' and z' filters over a field of view of 24x24 arcseconds. By choosing commercially available components wherever possible, the instrument could be built in short time and at comparably low cost. We present the instrument design, the data reduction pipeline, and summarise the performance and characteristicsComment: 12 pages, 7 figures, to appear in "Ground-based and Airborne Instrumentation for Astronomy II" SPIE conference, Marseille, 23-28 June 200

Static and Dynamic Aspects of Scientific Collaboration Networks

Collaboration networks arise when we map the connections between scientists which are formed through joint publications. These networks thus display the social structure of academia, and also allow conclusions about the structure of scientific knowledge. Using the computer science publication database DBLP, we compile relations between authors and publications as graphs and proceed with examining and quantifying collaborative relations with graph-based methods. We review standard properties of the network and rank authors and publications by centrality. Additionally, we detect communities with modularity-based clustering and compare the resulting clusters to a ground-truth based on conferences and thus topical similarity. In a second part, we are the first to combine DBLP network data with data from the Dagstuhl Seminars: We investigate whether seminars of this kind, as social and academic events designed to connect researchers, leave a visible track in the structure of the collaboration network. Our results suggest that such single events are not influential enough to change the network structure significantly. However, the network structure seems to influence a participant's decision to accept or decline an invitation.Comment: ASONAM 2012: IEEE/ACM International Conference on Advances in Social Networks Analysis and Minin

Development of proposals, including legal instruments, to improve the data situation on the whereabouts of end-of-life vehicles

To minimize the impact of end-of life vehicles on the environment they have to be managed in accordance with the legal requirements. Against this background it is important to comprehend the whereabouts of permanently decommissioned passenger cars. From the available statistical sources it was only possible to account for the whereabouts in parts for the last years. The subject-matter of the research project was the closure of this "statistical gap" to the maximum extent possible. The objectives of the project were the identification of the possible reasons underlying the "statistical gap", the determination, itemisation and, to the maximum extent possible, quantification of information on the actual whereabouts of permanently decommissioned vehicles and the development of measures and instruments that can be used to permanently improve the data situation

Suitability of Permanent Probe Implants For the Measurement of Intramedullary Perfusion and Temperature Near the Bone Cortex: A Pilot Study Using a Rabbit Model

This study was conducted to test the suitability of permanent probe implants for the measurement of  intramedullary perfusion by laser Doppler flowmetry and for the measurement of temperature near the  bone cortex. Measurements were carried out on the conscious animal in order to rule out the influence of  anaesthesia on intramedullary perfusion and temperature. During the first experimental animal trials, some  of the probes made of polysulphon broke and/or gave false temperature measurements, so the original  probe design was modified. The probes were reinforced with metal, and the temperature sensors were made  less permeable to moisture. These modified probes were found to be suitable for permanent measurement  of intramedullary perfusion and of temperature near the cortex in the conscious rabbit.

Norms and foreign policy: Constructivist foreign policy theory

Im Kontext des DFG-Forschungsprojekts 'Deutsche Außenpolitik nach der Vereinigung' am Institut für Politikwissenschaft der Universität Tübingen entstandenes Papier, das den konstruktivistischen Ansatz hinsichtlich der Außenpolitik, internationaler und gesellschaftlicher Normen darstellt

Normen und Außenpolitik : Konstruktivistische Außenpolitiktheorie

Im Kontext des DFG-Forschungsprojekts 'Deutsche Außenpolitik nach der Vereinigung' am Institut für Politikwissenschaft der Universität Tübingen entstandenes Papier, das den konstruktivistischen Ansatz hinsichtlich der Außenpolitik, internationaler und gesellschaftlicher Normen darstellt