Utopie Fernsehen

Die vorliegende Arbeit geht der Frage nach, wie das zu Beginn des 20. Jahrhunderts in den Laboratorien als technische Erfindung bereits erprobte, in der Öffentlichkeit aber bloß als Utopie existierende Fernsehen Einfluss auf Dziga Vertovs Verständnis von Film genommen hat. Einige Stellen in Vertovs Schriften zeugen von seiner Kenntnis über den aktuellen Entwicklungsstand der Fernsehtechnik um 1925. Zu diesem Zeitpunkt definiert Vertov den Film als eine Möglichkeit für Menschen, einander trotz der Entfernung sehen und hören zu können. Der 1926 entstandene Film Šestaja čast mira [Ein Sechstel der Erde] kann als Modell für die Utopie Fernsehen bei Vertov gelten. Mit der um 1929 beginnenden Einführung des Tonfilms nehmen Vertovs Entwürfe für eine auf Fernsehtechnik begründeten Produktionsweise von Filmen zu, durch die sich Vertov eine kollektive Autorenschaft erhofft. Das tatsächliche Fernsehen hingegen hat die in den frühen 1920er Jahren zirkulierenden Überlegungen zur Umverteilung der Produktionsmittel in sein Gegenteil verkehrt. Anscheinend lösen erst Videotechnik und die mögliche Verbreitung durch das WorldWideWeb die von Vertov projektierte Entwicklung einer „Massenautorenschaft“ ein.The present work pursues the question how television influenced Vertov’s understanding of cinema. Having already proved itself as invention in laboratories at the beginning of the 20th century, television only existed as an utopian dream. In some of his writings Vertov shows his knowledge of the current stage of television developement in 1925. At that time, Vertov defined the possibility of film as a chance for people to see and hear each other despite distance. Vertov’s feature-length film Šestaja čast mira [One Sixth of the World] from 1926 serves as a modell for his utopia of television. When the talkies started in 1929, Vertovs conceptions for a mode of film production based on technical methods of television increased, whereby Vertov hoped to achieve a collective authorship. But the actual television inverted these considerations of the early twenties about the shifting of resources into their opposite. Only the invention of video and the distribution through the WorldWideWeb seems to redeem Vertov’s idea of „mass authorship.

Identification and characterization of sRNAs in Streptomyces coelicolor

Streptomyces coelicolor ist der Modellorganismus der GC reichen, Gram+ Actinomyceten, die mehr als zwei Drittel aller bekannten Antibiotika produzieren. Phänotypisch zeichnet er sich durch die Bildung eines Substrat- und eines Luftmyzels aus, welches im Laufe der weiteren Differenzierung Sporen bildet. Streptomyceten produzieren neben Antibiotika noch eine Vielzahl biotechnologisch interessanter Metaboliten. Der komplexe Lebenszyklus und Stoffwechsel erfordern eine genaue Regulation der Genexpression. Die letzten Jahre haben gezeigt, dass neben Proteinen auch die RNA eine regulatorische Funktion hat. Verschiedene regulatorisch aktive RNA Elemente wie Riboswitche, RNA-Thermometer und kleine nicht kodierende RNAs (small noncoding RNAs – sRNAs) wurden identifiziert. sRNAs wirken meist als antisense Riboregulatoren, indem sie ihre Ziel-mRNA binden und dadurch die Translation hemmen oder fördern. In dieser Arbeit wurden verschiedene bioinformatische Methoden verwendet, um sRNAs im Genom von S. coelicolor vorherzusagen. Es wurden Terminatorstrukturen und konservierte Sekundärstrukturen in den intergenen Regionen vorhergesagt, die keinem Gen zuzuordnen waren. In einem weiteren Ansatz wurden Bindestellen des Regulatorproteins DasR vorhergesagt, um DasR kontrollierte sRNAs zu identifizieren. Zusätzlich wurde mittels 454 Sequenzierung erstmalig das Transkriptom von S. coeliocolor analysiert. Auf diese Weise konnten etwa 500 sRNAs vorhergesagt werden. Eine der beiden charakterisierten sRNAs, sc32, ist 139 nt lang. Ihr Promoter liegt im kodierenden Bereich des Gens bldC und sie wird spezifisch durch Kälteschock induziert. Die zweite charakterisierte sRNA, sc1, ist 159 nt lang und in allen sequenzierten Streptomyceten konserviert. Ihre Expression wird nur bei Stickstoffmangel in der Stationärphase reprimiert. Durch molekularbiologische Analysen konnte ein Zielgen von sc1 identifiziert werden, die extrazelluläre Agarase DagA. Es konnte gezeigt werden, dass sc1 an die dagA-mRNA bindet und dadurch die Translation inhibiert. Als zweites mögliches Ziel von sc1 konnte die Histidinkinase SCO5239 identifiziert werden. Hier wurde gezeigt, dass Koexpression von sc1 die Expression einer SCO5239 Reportergenfusion um den Faktor acht steigert. Durch Analyse des Proteoms von sc1 Mutanten, konnte die differenzierte Expression von elf weiteren Proteinen gezeigt werden. Sc1 scheint als Regulator zu agieren, indem es auf die Stickstoffversorgung der Zelle reagiert und den Sekundärmetabolismus deaktiviert.Streptomyces coelicolor is the model organism for the class of GC rich, gram+ actinomycetes that produce more than two thirds of all known antibiotics. It grows in a characteristic substrate and areal mycelium that during further development diffentiaties into spores. Next to antibiotics, Streptomycetes produce a variety of biotechnological interesting metabolites. This complex life cycle and metabolism demands a strict regulation of gene expression. The last years have shown, that next to proteins also RNA can have a regulatory function. Numerous regulatory active RNA elements like riboswitches, RNA-thermometers and small non coding RNAs (sRNAs) have been identified. In most cases sRNAs act as antisense riboregulators by binding to their target-mRNA and thereby blocking or activating its translation. In this work, several different bioinformatic methods were used to predict sRNAs in the genome of S. coelicolor. With these methods terminators and other conserved secondary structures in the intergenic regions of the genome that could not be assigned to an annotated gene were predicted. In another approach binding sites for the global regulator protein DasR were predicted to identify DasR-controlled sRNAs. Additionally for the first time the transcriptome of S. coelicolor was analyzed by 454 deep sequencing. Using this methods ~ 500 sRNAs could be predicted in the genome of S. coelicolor. One of the two characterized sRNAs – sc32 – is 139nt long. Its promoter resides in the conding region of the gene bldC and its expression is specifically induced by cold-shock conditions. The second characterized sRNA – sc1 – is 159nt long and conserved among all Streptomyces species sequenced today. Its expression is repressed by nitrogen starvation in stationary phase. By biochemical analyses a target mRNA of sc1 could be identified – the extracellular agarase dagA. It could be shown that sc1 binds to the dagA-mRNA and thereby hinders translation. As a second putative target of sc1 the histidine kinase SCO5239 could be identified. It was shown that coexpression of sc1 increases the expression of an SCO5239 reporter gene fusion eight times. Analysis of the proteome of sc1 mutants showed a differential expression of further eleven proteins. Sc1 seems to act as a regulator by sensing the nitrogen supply of the cell and in response deactivating the secondary metabolism

Early Pleistocene complex cut-and-fill sequences in the Alps

Cut-and-fill sequences are the result of climatically or tectonically induced alternating aggradation and incision phases of a fluvial system. A recently established cosmogenic nuclide chronology of the Cover Gravels (Deckenschotter in German) in the northern Alpine Foreland, which are the oldest Quaternary glaciofluvial gravels and comprise evidence of early Pleistocene glaciations, suggests a cut-and-fill build-up. This suggested cut-and-fill architecture challenges the morphostratigraphy. The Deckenschotter deposits represent a suitable archive for reconstructing drainage patterns, base level changes, and the landscape evolution of the northern Alpine Foreland during the early Pleistocene. In this study, we focused on the highest morphostratigraphic Deckenschotter sites: three at Irchel and one in the area around Lake Constance. Sediment analyses were performed to determine their provenance and depositional environments. The geochronology was established using isochron-burial dating. The results indicate that the sediments were transported from the Central and eastern Central Alps, as well as from the Molasse, to the foreland and deposited in a proximal glaciofluvial environment. Based on these findings, we propose that the Deckenschotter are cut-and-fill sequences that accumulated in three stages during the early Pleistocene at ca. 2.5 Ma, ca. 1.5 Ma, and ca. 1 Ma. The presence of a cut-and-fill system implies that the regional base level was relatively constant during the early Pleistocene. In addition, the ca. 2.5 Ma glaciofluvial gravels document the first evidence of glaciers in the northern Alpine Foreland. This timing is synchronous with the onset of Quaternary glaciation in the northern hemisphere at ca. 2.7 Ma

Age of the Most Extensive Glaciation in the Alps

Previous research suggested that the Alpine glaciers of the Northern Swiss Foreland reached their maximum extensive position during the Middle Pleistocene. Relict tills and glaciofluvial deposits, attributed to the Most Extensive Glaciation (MEG), have been found only beyond the extents of the Last Glacial Maximum (LGM). Traditionally, these sediments have been correlated to the Riss glaciation sensu Penck and Brückner and have been morphostratigraphically classified as the Higher Terrace (HT) deposits. The age of the MEG glaciation was originally proposed to be intermediate to the Brunhes/Matuyama transition (780 ka) and the Marine Isotope Stage 6 (191 ka). In this study, we focused on the glacial deposits in Möhlin (Canton of Aargau, Switzerland), in order to constrain the age of the MEG. The sediments from these deposits were analyzed to determine the provenance and depositional environments. We applied isochron-burial dating, with cosmogenic 10Be and 26Al, to the till layer in the Bünten gravel pit near Möhlin. Our results indicate that a glacier of Alpine origin reached its most extensive position during the Middle Pleistocene (500 ± 100 ka). The age of the MEG thus appears to be synchronous with the most extensive glaciations in the northern hemisphere

Nonuniform Late Pleistocene glacier fluctuations in tropical Eastern Africa

Today’s ice caps and glaciers in Africa are restricted to the highest peaks, but during the Pleistocene, several mountains on the continent were extensively glaciated. However, little is known about regional differences in the timing and extent of past glaciations and the impact of paleoclimatic changes on the afro-alpine environment and settlement history. Here, we present a glacial chronology for the Ethiopian Highlands in comparison with other East African Mountains. In the Ethiopian Highlands, glaciers reached their maximum 42 to 28 ka thousand years ago before the global Last Glacial Maximum. The local maximum was accompanied by a temperature depression of 4.4° to 6.0°C and a ~700-m downward shift of the afro-alpine vegetation belt, reshaping the human and natural habitats. The chronological comparison reveals that glaciers in Eastern Africa responded in a nonuniform way to past climatic changes, indicating a regionally varying influence of precipitation, temperature, and orography on paleoglacier dynamics

Strong lateral exchange coupling and current-induced switching in single-layer ferrimagnetic films with patterned compensation temperature

Strong, adjustable magnetic couplings are of great importance to all devices based on magnetic materials. Controlling the coupling between adjacent regions of a single magnetic layer, however, is challenging. In this work, we demonstrate strong exchange-based coupling between arbitrarily shaped regions of a single ferrimagnetic layer. This is achieved by spatially patterning the compensation temperature of the ferrimagnet by either oxidation or He+ irradiation. The coupling originates at the lateral interface between regions with different compensation temperature and scales inversely with their width. We show that this coupling generates large lateral exchange coupling fields and we demonstrate its application to control the switching of magnetically compensated dots with an electric current

Absolute Determination of the 22Na(p,g) Reaction Rate in Novae

Gamma-ray telescopes in orbit around the Earth are searching for evidence of the elusive radionuclide 22Na produced in novae. Previously published uncertainties in the dominant destructive reaction, 22Na(p,g)23Mg, indicated new measurements in the proton energy range of 150 to 300 keV were needed to constrain predictions. We have measured the resonance strengths, energies, and branches directly and absolutely by using protons from the University of Washington accelerator with a specially designed beamline, which included beam rastering and cold vacuum protection of the 22Na implanted targets. The targets, fabricated at TRIUMF-ISAC, displayed minimal degradation over a ~ 20 C bombardment as a result of protective layers. We avoided the need to know the stopping power, and hence the target composition, by extracting resonance strengths from excitation functions integrated over proton energy. Our measurements revealed that resonance strengths for E_p = 213, 288, 454, and 610 keV are stronger by factors of 2.4 to 3.2 than previously reported. Upper limits have been placed on proposed resonances at 198-, 209-, and 232-keV. We have re-evaluated the 22Na(p,g) reaction rate, and our measurements indicate the resonance at 213 keV makes the most significant contribution to 22Na destruction in novae. Hydrodynamic simulations including our rate indicate that the expected abundance of 22Na ejecta from a classical nova is reduced by factors between 1.5 and 2, depending on the mass of the white-dwarf star hosting the nova explosion.Comment: 20 pages, 18 figures; shortened paper, accepted in Phys. Rev.

Cosmogenic Exposure Dating (36Cl) of Landforms on Jan Mayen, North Atlantic, and the Effects of Bedrock Formation Age Assumptions on 36Cl Ages

Jan Mayen is a small volcanic island situated 550 km north of Iceland. Glacial sediments and landforms are relatively common on the island but, so far, only a few of them have been dated. In this study, we present and discuss 89 36Cl dates of primarily glacial and volcanic events on Jan Mayen. Calculations of sample exposure ages were complicated by young exposure ages, young rock formation age, and high native Cl contents, leading to updates in CRONUScalc to enable accurate exposure age calculations. The samples provide good evidence against an equilibrium assumption when subtracting background production (e.g., 36Cl produced by neutron capture from fission of U or Th) for samples on young bedrock, with younger exposure ages most significantly affected. Exposure ages were calculated with a range of assumptions of bedrock formation ages appropriate for Jan Mayen, including the assumption that the rock formation age equaled the exposure age (i.e., the youngest age it could possibly have), and we found that although the effect on most of the ages was small, the calculated ages of 25 of the samples increased by more than 1 standard deviation from the age calculated assuming equilibrium background production, with a maximum deviation of 6.1 ka. Due to the very young bedrock on Jan Mayen, we consider the nonequilibrium ages to be the most reliable ages from the island and conclude that large-scale deglaciation on the south and central, lower-lying, parts of the island, started around 20 ka and lasted until ~7 ka. On northern Jan Mayen, the slopes of the 2277 m high stratovolcano Beerenberg are currently partly glaciated; however, outside of the Little Ice Age moraines, all but two samples give ages between 14 and 5.7 ka