VLBI2010 - The TWIN radio telescope project at Wettzell, Germany

The Twin Telescope Wettzell (TTW) Project is funded to be exec uted during the period of 2008-2011. The design of the TTW was based on the VLBI2010 vision of the corresponding IVS Working Group. In the first two project years the design passed the simulations with respect to its specifications and was approved for production. At the Geodetic Observatory Wettzell a thorough soil analysis was made in order to define the sites for the towers of the new radio telescopes. Meanwhile the construction work has begun and acceptance tests of several telescope parts, e.g. azimuth bearings, took place. The full assembly of the radio telescopes is scheduled for the next two years. In parallel to the construction work at the Wettzell site, the design work for the different feed options progressed

Unseen Labor: An ATG Interview with Ann Kardos and Gretchen Neidhardt

Ann Kardos, creator of the Unseen Labor project, sought to tackle the mysteries of metadata work in a visual way. She invited colleagues to visually illustrate the story of metadata labor through stitching. ATG occasional contributor, Ramune Kubilius, asked some questions in order to learn more about this interesting, multi-faceted project

Virale und nichtvirale Gentherapieansätze zur Behandlung von Netzhauterkrankungen

Zusammenfassung: Für die Behandlung von Netzhauterkrankungen eröffnet der Einsatz der Gentherapie neue Perspektiven. Die Verwendung von verschiedenartigen Oligonukleotiden oder viralen Expressionsvektoren erlaubt die Entwicklung von neuen Heilungsstrategien für Neovaskularisierungskrankheiten und retinale Degeneration. Therapeutische Oligonukleotide ("Antisense"-Oligonukleotide, Aptamere und siRNA) können den gezielten Abbau von Transkripten und damit die Konzentrationsabnahme eines an der Pathogenese beteiligten Proteins induzieren. Dagegen wird mit viralen Vektoren (rAAV und Lentivirus) häufig die Funktion eines defekten Gens durch die eines gesunden ersetzt und so die Ursache der Krankheit bekämpft. Die an Tiermodellen erfolgreich angewandten Gentherapien führten bereits zur Entwicklung von Medikamenten, und weitere werden zurzeit klinisch erprob

Genome variation and molecular epidemiology of Salmonella enterica serovar Typhimurium pathovariants

Salmonella enterica serovar Typhimurium is one of approximately 2,500 distinct serovars of the genus Salmonella but is exceptional in its wide distribution in the environment, livestock, and wild animals. S. Typhimurium causes a large proportion of nontyphoidal Salmonella (NTS) infections, accounting for a quarter of infections, second only to S. enterica serovar Enteritidis in incidence. S. Typhimurium was once considered the archetypal broad-host-range Salmonella serovar due to its wide distribution in livestock and wild animals, and much of what we know of the interaction of Salmonella with the host comes from research using a small number of laboratory strains of the serovar (LT2, SL1344, and ATCC 14028). But it has become clear that these strains do not reflect the genotypic or phenotypic diversity of S. Typhimurium. Here, we review the epidemiological record of S. Typhimurium and studies of the host-pathogen interactions of diverse strains of S. Typhimurium. We present the concept of distinct pathovariants of S. Typhimurium that exhibit diversity of host range, distribution in the environment, pathogenicity, and risk to food safety. We review recent evidence from whole-genome sequencing that has revealed the extent of genomic diversity of S. Typhimurium pathovariants, the genomic basis of differences in the level of risk to human and animal health, and the molecular epidemiology of prominent strains. An improved understanding of the impact of genome variation of bacterial pathogens on pathogen-host and pathogen-environment interactions has the potential to improve quantitative risk assessment and reveal how new pathogens evolve

A Kohn-Sham system at zero temperature

An one-dimensional Kohn-Sham system for spin particles is considered which effectively describes semiconductor {nano}structures and which is investigated at zero temperature. We prove the existence of solutions and derive a priori estimates. For this purpose we find estimates for eigenvalues of the Schr\"odinger operator with effective Kohn-Sham potential and obtain $W^{1,2}$-bounds of the associated particle density operator. Afterwards, compactness and continuity results allow to apply Schauder's fixed point theorem. In case of vanishing exchange-correlation potential uniqueness is shown by monotonicity arguments. Finally, we investigate the behavior of the system if the temperature approaches zero.Comment: 27 page

The cytoplasm of living cells: A functional mixture of thousands of components

Inside every living cell is the cytoplasm: a fluid mixture of thousands of different macromolecules, predominantly proteins. This mixture is where most of the biochemistry occurs that enables living cells to function, and it is perhaps the most complex liquid on earth. Here we take an inventory of what is actually in this mixture. Recent genome-sequencing work has given us for the first time at least some information on all of these thousands of components. Having done so we consider two physical phenomena in the cytoplasm: diffusion and possible phase separation. Diffusion is slower in the highly crowded cytoplasm than in dilute solution. Reasonable estimates of this slowdown can be obtained and their consequences explored, for example, monomer-dimer equilibria are established approximately twenty times slower than in a dilute solution. Phase separation in all except exceptional cells appears not to be a problem, despite the high density and so strong protein-protein interactions present. We suggest that this may be partially a byproduct of the evolution of other properties, and partially a result of the huge number of components present.Comment: 11 pages, 1 figure, 1 tabl

Konjunkturen der NS-Bewegung: eine Untersuchung der Veranstaltungsaktivitäten der Münchener NSDAP, 1925-1930

"Basierend auf den Erkenntnissen der Soziologie sozialer Bewegungen werden die unterschiedlichen Konjunkturen in der Konstitutionsphase der NSDAP in München von 1925 bis 193O untersucht. Insbesondere wird entlang von framing-Strategien der Frage nachgegangen, ob und in welchem Maß die Nutzung besonderer Opportunitätsstrukturen der Partei den Durchbruch bei den Reichstagswahlen im September 1930 ermöglicht hat. Mittels einer inhaltsanalytischen Auswertung der im Völkischen Beobachter angekündigten Vortragsthemen öffentlicher Veranstaltungen der NSDAP in München kann gezeigt werden, daß es der NSDAP in dem ausgeprägten konjunkturellen 'auf und ab' der Parteiaktivitäten seit Anfang 1929 gelungen ist, dank eines zusammenhängenden Rahmens von Themen und deren geschickter Einbindung in identity, injustice und agency frames, spezifische political opportunities in geeigneter Weise in Sinnmuster zu integrieren und als zentrale Probleme für den Bewegungserfolg operativ und effektiv zu nutzen. Diese framing-Leistung ist der NSDAP in ihrer Durchbruchsphase offensichtlich mit eindrucksvollem Erfolg gelungen und hat ihren Aufstieg zur Macht zumindest erleichtert." (Autorenreferat)"Following insights of social movement theory, this paper looks at movement cycles during the initial development of the NSDAP in Munich between 1925 and 1930. The paper explores the different framing strategies the party employed in trying to make efficient use of opportunity structures in the political discourse of the late 1920s, for the mobilizations of resources and popular support. It is argued that changes in framing strategies after 1928 provided an important ingredient leading to the party's political breakthrough with the national elections of September 1930. Based on a content analysis of the official party newspaper, Völkischer Beobachter, the topics of political events and speeches the NSDAP organized in Munich between 1925 and 1930 are analyzed. The results show that, after a period of political difficulties in 1927-1928, the NSDAP managed to achieve a coherent set of themes around economic and political issues that had been characteristically absent in previous periods. Specifically, evidence is found that from 1929 onwards, the party managed to integrate an injustice frame with an identity frame and an agency frame to forge a politically powerful and forward-looking message that may have facilitated both its acceptance among broader segments of the population, and its ultimate rise to power." (author's abstract

Thermodynamics of Heat Shock Response

Production of heat shock proteins are induced when a living cell is exposed to a rise in temperature. The heat shock response of protein DnaK synthesis in E.coli for temperature shifts from temperature T to T plus 7 degrees, respectively to T minus 7 degrees is measured as function of the initial temperature T. We observe a reversed heat shock at low T. The magnitude of the shock increases when one increase the distance to the temperature $T_0 \approx 23^o$, thereby mimicking the non monotous stability of proteins at low temperature. Further we found that the variation of the heat shock with T quantitatively follows the thermodynamic stability of proteins with temperature. This suggest that stability related to hot as well as cold unfolding of proteins is directly implemented in the biological control of protein folding. We demonstrate that such an implementation is possible in a minimalistic chemical network.Comment: To be published in Physical Review Letter