The Hubble Constant from the Fornax Cluster Distance

Type Ia supernovae are the best cosmological standard candles available. The intrinsic scatter of their decline-rate- and colour-corrected peak brightnesses in the Hubble diagram is within observational error limits, corresponding to an uncertainty of only 3km/s/Mpc of the Hubble constant. Any additional uncertainty, resulting from peak-brightness calibration, must be kept small by measuring distances to nearby host galaxies most precisely. A number of different distance determinations of the Fornax cluster of galaxies agree well on a distance modulus of 31.35+-0.04mag (18.6+-0.3Mpc). This leads to accurate absolute magnitudes of the well-observed Fornax type Ia SNe SN1980N, SN1981D, and SN1992A and finally to a Hubble constant of H_0=72+-6km/s/Mpc.Comment: 5 pages, 1 figure, to be published in: Science in the VLT Era and Beyond. ESO VLT Opening Symposium, Springer, in press; typos remove

Langfristprojekte der Bundesregierung in der Energiepolitik

Der hohe Ölpreis, Bedenken hinsichtlich der künftigen Versorgungssicherheit beim Erdöl und die Sorge um die Umwelt haben die Aufmerksamkeit auf die Zusammensetzung der Energieversorgung gelenkt. Welche Rolle sollten in Zukunft die verschiedenen Energieträger spielen

Die Strompolitik vor neuen Aufgaben

Die aktuelle Strompolitik steht vor einer Reihe grundlegender Entscheidungen. Welche Aufgaben stehen an? Wie werden die Weichen gestellt? Welche Optionen bestehen? Georg Wilhelm Adamowitsch, Gert Maichel und Dieter Schmitt nehmen Stellung

Design, synthesis and pharmacological evaluation of nucleotidic and non-nucleotidic inhibitors and probes for the ecto-5'-nucleotidase (CD73)

Ecto-5'-nucleotidase (CD73) plays a central role in the metabolic breakdown of extracellular AMP. The enzyme is attached to the cell membrane by a glycosylphosphatidylinositol anchor, but can also be released by shedding, or integrated into exosomes. Overexpression of CD73 on cancer and immune cells leads to increased extracellular adenosine levels resulting in the activation of adenosine receptors (ARs). In the tumor microenvironment activation of ARs leads to an immunosuppressive, proliferation-enhancing, pro-angiogenic, and pro-metastatic environment. Several currently ongoing clincal studies evaluating monoclonal antibodies against CD73 and the first clinical studies employing a small-molecule CD73 inhibitor emphasize the clinical relevance of CD73 as a novel drug target. In this thesis, we describe the design, synthesis and pharmacological evaluation of CD73 inhibitors belonging to various scaffolds including α,β-methylene-adenosine diphosphates, diphosphonate mimetics, and xanthine derivatives. Furthermore, we describe the development of a fluorescent substrate, fluorescent probes, and further tool compounds for studying CD73. Whereas CD73 inhibitors could become a new class of immune-checkpoint inhibitory therapeutics, molecular probes have great potential as diagnostic tools and drugs

EU trade policy in the age of bilateralism

Together with a strong emphasis on deep integration, the main thrust of the EU's new trade strategy as announced in October 2006 is competitive regionalism, i.e. the competition between different jurisdictions which seek strategic advantages for themselves through the conclusion of bilateral agreements with priority trading partners. This article outlines the new trade strategy in the light of the changes caused by the Lisbon Treaty. It then presents a detailed positioning of the EU in the geography of international trade policy

Multiple-ionization of xenon atoms by positron impact

Previously the cross sections were measured for positronium formation and single ionization by positron impact for He and H2. With the same apparatus, slightly modified, the single and multiple ionization of xenon is now investigated. The principle of the method is the detection of ion and positron in time correlation which allows the discrimination of positronium formation (whereby the positron vanishes) and the destinction of single, double and triple impact ionization (which lead to different ion flight times from the gas target to the ion detector). By using secondary electrons from the positron moderator, similar measurements were performed on electron impact ionization. By comparing with literature values for electron multiple ionization cross sections, the detection-probability ratios were determined for the differently charged ions

Die Strompolitik vor neuen Aufgaben

Die aktuelle Strompolitik steht vor einer Reihe grundlegender Entscheidungen. Welche Aufgaben stehen an? Wie werden die Weichen gestellt? Welche Optionen bestehen? Georg Wilhelm Adamowitsch, Gert Maichel und Dieter Schmitt nehmen Stellung. --