66 research outputs found
Bildung über den ganzen Tag. Forschungs- und Theorieperspektiven der Erziehungswissenschaft
No full textDie Beiträge diskutieren aus verschiedenen erziehungswissenschaftlichen Perspektiven die Fragestellung, welche Rolle und Bedeutung der Ganztagsschule in der aktuellen Bildungsrealität zukommt. Theorie, Forschung, Politik und Praxis werden dabei aufeinander bezogen, so dass zugleich ein Blick auf die aktuelle Positionierung der Erziehungswissenschaft geworfen wird. Am Fall der Ganztagsschulthematik werden exemplarisch zentrale innerdisziplinäre Probleme diskutiert
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No full textThe marine heterotrophic roseobacter Phaeobacter gallaeciensis DSM 17395 was grown with glucose in defined mineral medium. Relative abundance changes of global protein (2-D DIGE) and metabolite (GC-MS) profiles were determined across five different time points of growth. In total, 215 proteins were identified and 147 metabolites detected (101 structurally identified), among which 60 proteins and 87 metabolites displayed changed abundances upon entry into stationary growth phase. Glucose breakdown to pyruvate apparently proceeds via the Entner-Doudoroff (ED) pathway, since phosphofructokinase of the Embden-Meyerhof-Parnas pathway is missing and the key metabolite of the ED-pathway, 2-keto-3-desoxygluconate, was detected. The absence of pfk in other genome-sequenced roseobacters suggests that the use of the ED pathway is an important physiological property among these heterotrophic marine bacteria. Upon entry into stationary growth phase (due to glucose starvation), sulfur assimilation (including cysteine biosynthesis) and parts of cell envelope synthesis (e.g. the lipid precursor 1-monooleoylglycerol) were down-regulated and cadaverine formation up-regulated. In contrast, central carbon catabolism remained essentially unchanged, pointing to a metabolic "stand-by" modus as an ecophysiological adaptation strategy. Stationary phase response of P. gallaeciensis differs markedly from that of standard organisms such as Escherichia coli, as evident e.g. by the absence of an rpoS gene
Comparative genome analysis and genome-guided physiological analysis of <it>Roseobacter litoralis</it>
No full textAbstract Background Roseobacter litoralis OCh149, the type species of the genus, and Roseobacter denitrificans OCh114 were the first described organisms of the Roseobacter clade, an ecologically important group of marine bacteria. Both species were isolated from seaweed and are able to perform aerobic anoxygenic photosynthesis. Results The genome of R. litoralis OCh149 contains one circular chromosome of 4,505,211 bp and three plasmids of 93,578 bp (pRLO149_94), 83,129 bp (pRLO149_83) and 63,532 bp (pRLO149_63). Of the 4537 genes predicted for R. litoralis, 1122 (24.7%) are not present in the genome of R. denitrificans. Many of the unique genes of R. litoralis are located in genomic islands and on plasmids. On pRLO149_83 several potential heavy metal resistance genes are encoded which are not present in the genome of R. denitrificans. The comparison of the heavy metal tolerance of the two organisms showed an increased zinc tolerance of R. litoralis. In contrast to R. denitrificans, the photosynthesis genes of R. litoralis are plasmid encoded. The activity of the photosynthetic apparatus was confirmed by respiration rate measurements, indicating a growth-phase dependent response to light. Comparative genomics with other members of the Roseobacter clade revealed several genomic regions that were only conserved in the two Roseobacter species. One of those regions encodes a variety of genes that might play a role in host association of the organisms. The catabolism of different carbon and nitrogen sources was predicted from the genome and combined with experimental data. In several cases, e.g. the degradation of some algal osmolytes and sugars, the genome-derived predictions of the metabolic pathways in R. litoralis differed from the phenotype. Conclusions The genomic differences between the two Roseobacter species are mainly due to lateral gene transfer and genomic rearrangements. Plasmid pRLO149_83 contains predominantly recently acquired genetic material whereas pRLO149_94 was probably translocated from the chromosome. Plasmid pRLO149_63 and one plasmid of R. denitrifcans (pTB2) seem to have a common ancestor and are important for cell envelope biosynthesis. Several new mechanisms of substrate degradation were indicated from the combination of experimental and genomic data. The photosynthetic activity of R. litoralis is probably regulated by nutrient availability.</p
Phaeobacter gallaeciensis genomes from globally opposite locations reveal high similarity of adaptation to surface life
No full textPhaeobacter gallaeciensis, a member of the abundant marine Roseobacter clade, is known to be an effective colonizer of biotic and abiotic marine surfaces. Production of the antibiotic tropodithietic acid (TDA) makes P. gallaeciensis a strong antagonist of many bacteria, including fish and mollusc pathogens. In addition to TDA, several other secondary metabolites are produced, allowing the mutualistic bacterium to also act as an opportunistic pathogen. Here we provide the manually annotated genome sequences of the P. gallaeciensis strains DSM 17395 and 2.10, isolated at the Atlantic coast of north western Spain and near Sydney, Australia, respectively. Despite their isolation sites from the two different hemispheres, the genome comparison demonstrated a surprisingly high level of synteny (only 3% nucleotide dissimilarity and 88% and 93% shared genes). Minor differences in the genomes result from horizontal gene transfer and phage infection. Comparison of the P. gallaeciensis genomes with those of other roseobacters revealed unique genomic traits, including the production of iron-scavenging siderophores. Experiments supported the predicted capacity of both strains to grow on various algal osmolytes. Transposon mutagenesis was used to expand the current knowledge on the TDA biosynthesis pathway in strain DSM 17395. This first comparative genomic analysis of finished genomes of two closely related strains belonging to one species of the Roseobacter clade revealed features that provide competitive advantages and facilitate surface attachment and interaction with eukaryotic hosts
Enige metingen aan een ladingsgewijs bedreven en continu doorstroomde tankreactor met propellerroerder
No full textApplied SciencesKramers Laboratorium voor Fysische Technologi
Biogeography and phylogenetic diversity of a cluster of exclusively marine myxobacteria
No full textMyxobacteria are common in terrestrial habitats and well known for their formation of fruiting bodies and production of secondary metabolites. We studied a cluster of myxobacteria consisting only of sequences of marine origin (marine myxobacteria cluster, MMC) in sediments of the North Sea. Using a specific PCR, MMC sequences were detected in North Sea sediments down to 2.2 m depth, but not in the limnetic section of the Weser estuary and other freshwater habitats. In the water column, this cluster was only detected on aggregates up to a few meters above the sediment surface, but never in the fraction of free-living bacteria. A quantitative real-time PCR approach revealed that the MMC constituted up to 13% of total bacterial 16S rRNA genes in surface sediments of the North Sea. In a global survey, including sediments from the Mediterranean Sea, the Atlantic, Pacific and Indian Ocean and various climatic regions, the MMC was detected in most samples and to a water depth of 4300 m. Two fosmids of a library from sediment of the southern North Sea containing 16S rRNA genes affiliated with the MMC were sequenced. Both fosmids have a single unlinked 16S rRNA gene and no complete rRNA operon as found in most bacteria. No synteny to other myxobacterial genomes was found. The highest numbers of orthologues for both fosmids were assigned to Sorangium cellulosum and Haliangium ochraceum. Our results show that the MMC is an important and widely distributed but largely unknown component of marine sediment-associated bacterial communities
Desigualdades sociais, modernização da sociedade e “trabalho social" Considerações acerca do projeto do serviço social na "era da globalização"
No full textThe sociocultural climate in the Northern countries has become more impetuous and cold. In many places the social architecture has been disposed of. Are the Northern capitalist bourgeois countries moving away from a state order committed to the social welfare and moving towards an order that is exclusively bound to the rationality of the capitalist market? This study discusses this issue in three steps. Initially, it presents some points of diagnoses of the present social situation in Germany and contrasts them with selected data about Brazilian society with the purpose of better explaining them. In the second step, the author develops the thesis that the profound transformations in Western industrial countries are structurally similar to the transformation processes that are taking place in the “developing countries”. Finally, the study deals with the meaning and significance of those social transformations for social work.
Key words: Social inequalities; Social welfare; Globalization; Social Work; GermanyO clima sócio-cultural nos países do hemisfério norte vem se tornando mais impetuoso e frio. Em muitos lugares, a arquitetura social está sendo colocada à disposição. Será que os países burgueses capitalistas do hemisfério norte estão se afastando de uma ordem estatal comprometida com o bem-estar social, aproximando-se de uma ordem exclusivamente presa às racionalidades do mercado capitalista? Nossa contribuição abordará estas questões em três passos. Primeiro, serão apresentados, de modo pontual, alguns diagnósticos referentes à atual situação social na Alemanha, confrontando-os com dados selecionados sobre a sociedade brasileira, no intuito de facilitar sua explicação. Num segundo passo, defenderemos a tese de que as transformações profundas nos países industrializados ocidentais são estruturalmente pouco diferentes em comparação com os processos de transformação que ocorrem nos “países emergentes”. E, finalmente, será tratado o significado dessas transformações sociais para o trabalho social. Palavras-chave: Desigualdades sociais; Bem-estar social; Globalização; Serviço Social; Alemanha
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