Multiwavelength and parsec-scale properties of extragalactic jets

Extragalactic jets originating from the central supermassive black holes of active galaxies are powerful, highly relativistic plasma outflows, emitting light from the radio up to the gamma-ray regime. The details of their formation, composition and emission mechanisms are still not completely clear. The combination of high-resolution observations using very long baseline interferometry (VLBI) and multiwavelength monitoring provides the best insight into these objects. Here, such a combined study of sources of the TANAMI sample is presented, investigating the parsec-scale and high-energy properties. The TANAMI program is a multiwavelength monitoring program of a sample of the radio and gamma-ray brightest extragalactic jets in the southern sky, below -30deg declination. We obtain the first-ever VLBI images for most of the sources, providing crucial information on the jet kinematics and brightness distribution at milliarcsecond resolution. Two particular sources are discussed in detail: PMN J1603-4904, which can be classified either as an atypical blazar or a gamma-ray loud (young) radio galaxy, and Centaurus A, the nearest radio-loud active galaxy. The VLBI kinematics of the innermost parsec of Centaurus A's jet result in a consistent picture of an accelerated jet flow with a spine-sheath like structure.Comment: Doctoral Thesis Award Lecture 2015, AN 2016, 337,

Incentive Compatible Extraction of Natural Resource Rent

The exploitation of natural resources often generates considerable economic rent. Since such so-called resource rents accrue due to innate characteristics of the resource itself thus reflecting its eco-nomic value and not due to managerial abilities of the exploiting firm, at least part of it should - as a price for the use of the resource – be collected by the owner of the resource, which is often the gov-ernment. As the owner of the resource faces a classical principal-agent problem, the incentives to exploit a resource efficiently should be taken into account when setting up a rent extraction scheme. We pre-sent a formalism that unifies different existing approaches to such schemes and address issues such as asymmetric information, risk aversion, and uncertainty. Finally, we discuss the feasibility to base a rent extraction scheme on such a formalism and point out its main problems. The most important ones are the presence of intrinsically unobservable and very uncertain values and the high complexity of the formalism. There are mainly two possibilities to deal with these problems: either to make additional as-sumptions and to set boundary conditions such as to solve the problem in a simplified setting, as much of the literature does, or to refrain from solving it, and instead use it as a general guiding principle, which helps to avoid gross errors and shows the broad direction, but leaves the concrete implementa-tion rather to a political process than to an economic analysis.natural resource rent, incentives, rent extraction, regulation

Empirical study of the influence of social groups in evacuation scenarios

The effects of social groups on pedestrian dynamics, especially in evacuation scenarios, have attracted some interest recently. However, due to the lack of reliable empirical data, most of the studies focussed on modelling aspects. It was shown that social groups can have a considerable effect, e.g. on evacuation times. In order to test the model predictions we have performed laboratory experiments of evacuations with different types and sizes of the social groups. The experiments have been performed with pupils of different ages. Parameters that have been considered are (1) group size, (2) strength of intra-group interactions, and (3) composition of the groups (young adults, children, and mixtures). For all the experiments high-quality trajectories for all participants have been obtained using the PeTrack software. This allows for a detailed analysis of the group effects. One surprising observation is a decrease of the evacuation time with increasing group size.Comment: 8 pages, 4 figures, to be published in Traffic and Granular Flow '15 (Springer, 2016

Innovativ und international – mit regionalem Personal: Ergebnisse einer Befragung von New Economy-Unternehmen in Sachsen und Thüringen

BT and IT firms in Saxony and Thuringia were surveyed about their recruiting activities, the scope of their product markets and their R&D activities. The major findings are: The majority of firms engage in product and process development, their product markets are not predominantly local markets, and that they recruit their labor force in the local labor market. The latter fact is explained by the existence of the modern infrastructure in higher learning and research in the new Länder (which formerly constituted the GDR). Consequently the firms are optimistic to be also able to attract highly qualified personnel in the future.The recently enacted law, which grants a number of work permits for highly qualified jobs (green card) is therefore of no great significance to these firms.

Current concepts of ectopic nodal inclusions with special emphasis on nodal nevi

Nodal inclusions of ectopic tissue within lymph nodes are seen comparatively often in dermatopathology and general pathology. Glandular and nonglandular epithelium, as well as melanocytic nevi can be observed within lymph nodes and represent mostly incidental findings without any relevance. The main challenge in reporting these morphologic features is to differentiate such benign inclusions from metastatic settlements of distinct organ tumors. As sentinel node biopsy and lymph node dissection have become standard procedure in clinical oncology and have an immense clinical impact, the correct evaluation of these nodal inclusions is indispensable to avoid undertreatment or overtreatment of patients. In addition, the genesis of these inclusions has not yet been satisfactorily clarified. Two concepts have been laid out: the theory of benign metastases and the migration arrest theory. However, neither theory has so far been able to answer the following questions: Why do we find more nodal nevi in patients with melanoma who had a sentinel node biopsy than in patients without melanoma, and why do we not find nodal nevi in deep visceral lymph nodes? We present a comprehensive review of the current knowledge on nodal inclusions, proposing a concept for the pathogenesis of nodal nevi, to answer these questions

Internationales Product Management 2011 : Einsatz und Trends – Ergebnisse Schweiz

StudieIm Bereich Product Management führen wir 2011 erstmalig eine umfassende Studie zum Status Quo und den aktuellen Trends des Product Managements durch. Befragt werden Product Management-Entscheidungsträger aus der Schweiz sowie aus dem Ausland

Schützen Statine vor Schlaganfall und Alzheimer? : neue Therapiemöglichkeiten im Zentralnervensystem

Statine stellen heute Medikamente der ersten Wahl bei zu hohen Cholesterin- Blutwerten dar. Denn sie hemmen die Hydroxymethylglutaryl-CoA Reduktase (HMG-CoA Reduktase), ein wichtiges Schlüsselenzym, das für die körpereigene Herstellung von Cholesterin notwendig ist. Bei der pharmakologischen Bewertung der Statine muss allerdings auch der Cholesterinstoffwechsel im Gehirn berücksichtigt werden, dem cholesterinreichsten Organ des menschlichen Körpers. Bislang existieren nur wenige Daten zu den Effekten dieser Medikamente im zentralen Nervensystem. Im Rahmen eines Leitprojekts des Zentrums für Arzneimittelforschung, -Entwicklung und Sicherheit (ZAFES) wird derzeit die Pharmakologie der Statine im Gehirn intensiv untersucht, um die therapeutischen Einsatzmöglichkeiten von Statinen im Zusammenhang mit der Therapie von Erkrankungen, wie Schlaganfall und Alzheimer-Demenz, aufzuklären und gegebenenfalls zu erweitern

X-ray monitoring of the radio and gamma-ray loud Narrow-Line Seyfert 1 Galaxy PKS 2004-447

We present preliminary results of the X-ray analysis of XMM-Newton and Swift observations as part of a multi-wavelength monitoring campaign in 2012 of the radio-loud narrow line Seyfert 1 galaxy PKS 2004-447. The source was recently detected in gamma-rays by Fermi/LAT among only four other galaxies of that type. The 0.5-10 keV X-ray spectrum is well-described by a simple absorbed powerlaw (photon index ~ 1.6). The source brightness exhibits variability on timescales of months to years with indications for spectral variability, which follows a 'bluer-when-brighter' behaviour, similar to blazars.Comment: Proceedings for the 'Jet 2013' conference. Includes 3 pages, 3 figure