376 research outputs found
Early endosomal SNAREs form a structurally conserved SNARE complex and fuse liposomes with multiple topologies
Stand, Probleme, Perspektiven der Ausbildung im Fachseminar SoWi
Über Stand, Probleme und Perspektiven der Ausbildung im Fachseminar Sozialwissenschaften (Wirtschaft und Politik etc.) in der Zweiten Phase der Lehrerausbildung in den 16 Bundesländern gibt es keinen vergleichenden und aktuellen Überblick. Das folgende Gespräch versucht diesem Defizit ansatzweise entgegenzuwirken, indem Fachleiter aus drei Bundesländern (Hessen, Nordrhein-Westfalen, Thüringen) die Situation in ihrem Fachseminar und Arbeitsfeld darstellen und bewerten. Die Informationen und Statements wurden online eingeholt. Die Stellungnahmen wurden untereinander ausgetauscht und gelesen; es wurde aber darauf verzichtet, die einzelnen Positionen untereinander zu kommentieren, da dies die Situation eines natürlichen Gruppeninterviews vor Ort erfordert hätte. Schon ein Blick auf die Tabelle am Ende des Gesprächs zeigt Unterschiede in den Bezeichnungen und der Organisation im Detail auf. Auf der inhaltlichen Ebene zeigen sich aber gemeinsame Probleme, die Berufsanfänger auf dem Weg der Professionalisierung zu bewältigen haben. Das Gespräch soll systematische Bestandsaufnahme und Forschung zur Fachausbildung SoWi im Referendariat anregen.
There is no comparative and current overview regarding conditions, problems and perspectives of teacher training in the subject orientated course for student teachers (Fachseminar) prior to second state examination (Staatsexamen) in the field of social sciences (civics, economics and politics etc.). Conditions among the 16 Federal states of Germany differ in detail. The following discussion tries to work against this deficit basically, as specialized leaders from three Federal states (Hessen, North Rhine-Westphalia, Thuringia) represent and evaluate the situation in their field of work. The information and statements were caught up on-line. The statements were exchanged among themselves but not commentated since this would have required the situation of a natural group interview. The table at the end points out significiant differences in the designations and the organization in the detail. On the other hand there seems to be shared/common problems, which novices have to master on their way of professionalization. The discussion aims at fostering systematic documentation and research for subjet orientated social science teacher training in the Referendariat
Heterozygous, Polyploid, Giant Bacterium, Achromatium, Possesses an Identical Functional Inventory Worldwide across Drastically Different Ecosystems
Achromatium is large, hyperpolyploid and the only known heterozygous bacterium. Single cells contain approximately 300 different chromosomes with allelic diversity far exceeding that typically harbored by single bacteria genera. Surveying all publicly available sediment sequence archives, we show that Achromatium is common worldwide, spanning temperature, salinity, pH, and depth ranges normally resulting in bacterial speciation. Although saline and freshwater Achromatium spp. appear phylogenetically separated, the genus Achromatium contains a globally identical, complete functional inventory regardless of habitat. Achromatium spp. cells from differing ecosystems (e.g., from freshwater to saline) are, unexpectedly, equally functionally equipped but differ in gene expression patterns by transcribing only relevant genes. We suggest that environmental adaptation occurs by increasing the copy number of relevant genes across the cell’s hundreds of chromosomes, without losing irrelevant ones, thus maintaining the ability to survive in any ecosystem type. The functional versatility of Achromatium and its genomic features reveal alternative genetic and evolutionary mechanisms, expanding our understanding of the role and evolution of polyploidy in bacteria while challenging the bacterial species concept and drivers of bacterial speciation
Imprint of past and present environmental conditions on microbiology and biogeochemistry of coastal Quaternary sediments
To date, North Sea tidal-flat sediments have been intensively studied down to a depth of 5 m below seafloor (mbsf). However, little is known about the biogeochemistry, microbial abundance, and activity of sulfate reducers as well as methanogens in deeper layers. In this study, two 20 m-long cores were retrieved from the tidal-flat area of Spiekeroog Island, NW Germany. The drill sites were selected with a close distance of 900 m allowing to compare two depositional settings: first, a paleo-channel filled with Holocene sediments and second, a mainly Pleistocene sedimentary succession. Analyzing these cores, we wanted to test to which degree the paleo-environmental imprint is superimposed by present processes. <br><br> In general, the numbers of bacterial 16S rRNA genes are one to two orders of magnitude higher than those of <i>Archaea</i>. The abundances of key genes for sulfate reduction and methanogenesis (<i>dsr</i>A and <i>mcr</i>A) correspond to the sulfate and methane profiles. A co-variance of these key genes at sulfate-methane interfaces and enhanced ex situ AOM rates suggest that anaerobic oxidation of methane may occur in these layers. Microbial and biogeochemical profiles are vertically stretched relative to 5 m-deep cores from shallower sediments in the same study area, but still appear compressed compared to deep sea sediments. Our interdisciplinary analysis shows that the microbial abundances and metabolic rates are elevated in the Holocene compared to Pleistocene sediments. However, this is mainly due to present environmental conditions such as pore water flow and organic matter availability. The paleo-environmental imprint is still visible but superimposed by these processes
Анализ динамики состояния растительного покрова на территориях снегоотвалов с использованием геоинформационных технологий и космических снимков
International audienc
Genome sequence of Desulfobacterium autotrophicum HRM2, a marine sulfate reducer oxidizing organic carbon completely to carbon dioxide
Sulfate-reducing bacteria (SRB) belonging to the metabolically versatile Desulfobacteriaceae are abundant in marine sediments and contribute to the global carbon cycle by complete oxidation of organic compounds. Desulfobacterium autotrophicum HRM2 is the first member of this ecophysiologically important group with a now available genome sequence. With 5.6 megabasepairs (Mbp) the genome of Db. autotrophicum HRM2 is about 2 Mbp larger than the sequenced genomes of other sulfate reducers (SRB). A high number of genome plasticity elements (> 100 transposon-related genes), several regions of GC discontinuity and a high number of repetitive elements (132 paralogous genes Mbp−1) point to a different genome evolution when comparing with Desulfovibrio spp. The metabolic versatility of Db. autotrophicum HRM2 is reflected in the presence of genes for the degradation of a variety of organic compounds including long-chain fatty acids and for the Wood–Ljungdahl pathway, which enables the organism to completely oxidize acetyl-CoA to CO2 but also to grow chemolithoautotrophically. The presence of more than 250 proteins of the sensory/regulatory protein families should enable Db. autotrophicum HRM2 to efficiently adapt to changing environmental conditions. Genes encoding periplasmic or cytoplasmic hydrogenases and formate dehydrogenases have been detected as well as genes for the transmembrane TpII-c3, Hme and Rnf complexes. Genes for subunits A, B, C and D as well as for the proposed novel subunits L and F of the heterodisulfide reductases are present. This enzyme is involved in energy conservation in methanoarchaea and it is speculated that it exhibits a similar function in the process of dissimilatory sulfate reduction in Db. autotrophicum HRM2
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