349 research outputs found

    Ganztagsgrundschulen auf dem Weg zu Konzepten individueller Förderung. Ein Fortbildungsbaustein des BLK-Verbundprojekts "Lernen fĂŒr den GanzTag"

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    Individuelle Förderung ist ein zentraler Anspruch schulischer Bildung und Erziehung, fĂŒr den Ganztagsschulen besonders gĂŒnstige Rahmenbedingungen ermöglichen. Dennoch ergeben sich bei der Entwicklung schulspezifischer Konzepte individueller Förderung in Offenen Ganztagsgrundschulen (OGS) aus Sicht der Organisationsentwicklung einige Herausforderungen, fĂŒr deren Bearbeitung das Modul „Individuelle Förderung in der Offenen Ganztagsschule im Primarbereich“ des BLK-Verbundprojekts „Lernen fĂŒr den GanzTag“ eine Handreichung sein will. (DIPF/Orig.

    Bovine Endometrial Epithelial Cells Scale Their Pro-inflammatory Response In vitro to Pathogenic Trueperella pyogenes Isolated from the Bovine Uterus in a Strain-Specific Manner

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    Among different bacteria colonizing the bovine uterus, Trueperella pyogenes is found to be associated with clinical endometritis (CE). The ability of cows to defend against T. pyogenes infections depends on the virulence of invading bacteria and on the host's innate immunity. Therefore, to gain insights into bacterial factors contributing to the interplay of this host pathogen, two strains of T. pyogenes were included in this study: one strain (TP2) was isolated from the uterus of a postpartum dairy cow developing CE and a second strain (TP5) was isolated from a uterus of a healthy cow. The two strains were compared in terms of their metabolic fingerprints, growth rate, virulence gene transcription, and effect on bovine endometrial epithelial cells in vitro. In addition, the effect of the presence of peripheral blood mononuclear cells (PBMCs) on the response of endometrial epithelial cells was evaluated. TP2, the strain isolated from the diseased cow, showed a higher growth rate, expressed more virulence factors (cbpA, nanH, fimE, and fimG), and elicited a higher mRNA expression of pro-inflammatory factors (PTGS2, CXCL3, and IL8) in bovine endometrial epithelial cells compared with TP5, the strain isolated from the healthy cow. The presence of PBMCs amplified the mRNA expression of pro-inflammatory factors (PTGS2, CXCL3, IL1A, IL6, and IL8) in bovine endometrial epithelial cells co-cultured with live TP2 compared with untreated cells, especially as early as after 4 h. In conclusion, particular strain characteristics of T. pyogenes were found to be important for the development of CE. Furthermore, immune cells attracted to the site of infection might also play an important role in up-regulation of the pro-inflammatory response in the bovine uterus and thus significantly contribute to the host-pathogen interaction

    Impacts of dust deposition on dissolved trace metal concentrations (Mn, Al and Fe) during a mesocosm experiment

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    The deposition of atmospheric dust is the primary process supplying trace elements abundant in crustal rocks (e.g. Al, Mn and Fe) to the surface ocean. Upon deposition, the residence time in surface waters for each of these elements differs according to their chemical speciation and biological utilization. Presently, however, the chemical and physical processes occurring after atmospheric deposition are poorly constrained, principally because of the difficulty in following natural dust events in situ. In the present work we examined the temporal changes in the biogeochemistry of crustal metals (in particular Al, Mn and Fe) after an artificial dust deposition event. The experiment was contained inside trace metal clean mesocosms (0–12.5 m depths) deployed in the surface waters of the northwestern Mediterranean, close to the coast of Corsica within the frame of the DUNE project (a DUst experiment in a low Nutrient, low chlorophyll Ecosystem). Two consecutive artificial dust deposition events, each mimicking a wet deposition of 10 g m−2 of dust, were performed during the course of this DUNE-2 experiment. The changes in dissolved manganese (Mn), iron (Fe) and aluminum (Al) concentrations were followed immediately after the seeding with dust and over the following week. The Mn, Fe and Al inventories and loss or dissolution rates were determined. The evolution of the inventories after the two consecutive additions of dust showed distinct behaviors for dissolved Mn, Al and Fe. Even though the mixing conditions differed from one seeding to the other, Mn and Al showed clear increases directly after both seedings due to dissolution processes. Three days after the dust additions, Al concentrations decreased as a consequence of scavenging on sinking particles. Al appeared to be highly affected by the concentrations of biogenic particles, with an order of magnitude difference in its loss rates related to the increase of biomass after the addition of dust. In the case of dissolved Fe, it appears that the first dust addition resulted in a decrease as it was scavenged by sinking dust particles, whereas the second seeding induced dissolution of Fe from the dust particles due to the excess Fe binding ligand concentrations present at that time. This difference, which might be related to a change in Fe binding ligand concentration in the mesocosms, highlights the complex processes that control the solubility of Fe. Based on the inventories at the mesocosm scale, the estimations of the fractional solubility of metals from dust particles in seawater were 1.44 ± 0.19% and 0.91 ± 0.83% for Al and 41 ± 9% and 27 ± 19% for Mn for the first and the second dust addition. These values are in good agreement with laboratory-based estimates. For Fe no fractional solubility was obtained after the first seeding, but 0.12 ± 0.03% was estimated after the second seeding. Overall, the trace metal dataset presented here makes a significant contribution to enhancing our knowledge on the processes influencing trace metal release from Saharan dust and the subsequent processes of bio-uptake and scavenging in a low nutrient, low chlorophyll are

    Photocapacitance study of type-II GaSb/GaAs quantum ring solar cells

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    In this study, the density of states associated with the localization of holes in GaSb/GaAs quantum rings are determined by the energy selective charging of the quantum ring distribution. The authors show, using conventional photocapacitance measurements, that the excess charge accumulated within the type-II nanostructures increases with increasing excitation energies for photon energies above 0.9 eV. Optical excitation between the localized hole states and the conduction band is therefore not limited to the Γ(k = 0) point, with pseudo-monochromatic light charging all states lying within the photon energy selected. The energy distribution of the quantum ring states could consequently be accurately related from the excitation dependence of the integrated photocapacitance. The resulting band of localized hole states is shown to be well described by a narrow distribution centered 407 meV above the GaAs valence band maximum

    E2F Family Members Are Differentially Regulated by Reversible Acetylation

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    The six members of the E2F family of transcription factors play a key role in the control of cell cycle progression by regulating the expression of genes involved in DNA replication and cell proliferation. E2F-1, -2, and -3 belong to a structural and functional subfamily distinct from those of the other E2F family members. Here we report that E2F-1, -2, and -3, but not E2F-4, -5, and -6, associate with and are acetylated by p300 and cAMP-response element-binding protein acetyltransferases. Acetylation occurs at three conserved lysine residues located at the N-terminal boundary of their DNA binding domains. Acetylation of E2F-1 in vitro and in vivo markedly increases its binding affinity for a consensus E2F DNA-binding site, which is paralleled by enhanced transactivation of an E2F-responsive promoter. Acetylation of E2F-1 can be reversed by histone deacetylase-1, indicating that reversible acetylation is a mechanism for regulation also of non-histone proteins

    Neue Chance fĂŒr den Nordsee-Kabeljau: Seevögel machen bereits im Sommer 2001 auf starken Jahrgang aufmerksam

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    Im Oktober/November des vergangenen Jahres ergab sich wĂ€hrend der 483. Reise von FK „Solea“ ein im Vergleich zu den vier Vorjahren hoher Fangindex von 220 Kabeljau Gadus morhua je Stunde (Weber 2001). Die Fische hatten eine LĂ€nge von 15 bis18 cm und waren besonders in KĂŒstennĂ€he Ostfrieslands anzutreffen. Durch unsere Langzeituntersuchungen zur Ökologie der Flussseeschwalbe Sterna hirundo im Wattenmeer sind wir bereits im Juni des Jahres 2001 auf den starken Jahrgang des Kabeljaus aufmerksam geworden und können die Vermutung von Weber bestĂ€tigen, dass die Kabeljaus den Sommer ĂŒber im Wattengebiet herangewachsen sind
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