21 research outputs found

    AZT resistance of simian foamy virus reverse transcriptase is based on the excision of AZTMP in the presence of ATP

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    Azidothymidine (AZT, zidovudine) is one of the few nucleoside inhibitors known to inhibit foamy virus replication. We have shown previously that up to four mutations in the reverse transcriptase gene of simian foamy virus from macaque (SFVmac) are necessary to confer high resistance against AZT. To characterize the mechanism of AZT resistance we expressed two recombinant reverse transcriptases of highly AZT-resistant SFVmac in Escherichia coli harboring three (K211I, S345T, E350K) or four mutations (K211I, I224T, S345T, E350K) in the reverse transcriptase gene. Our analyses show that the polymerization activity of these mutants is impaired. In contrast to the AZT-resistant reverse transcriptase of HIV-1, the AZT resistant enzymes of SFVmac reveal differences in their kinetic properties. The SFVmac enzymes exhibit lower specific activities on poly(rA)/oligo(dT) and higher KM-values for polymerization but no change in KD-values for DNA/DNA or RNA/DNA substrates. The AZT resistance of the mutant enzymes is based on the excision of the incorporated inhibitor in the presence of ATP. The additional amino acid change of the quadruple mutant appears to be important for regaining polymerization efficiency

    Inklusionsorientierte Schulentwicklung

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    Der Band eröffnet einen interdisziplinären Zugang zur Thematik der inklusionsorientierten Schulentwicklung, indem die Dimensionen der Organisations-, Personal- und Unterrichtsentwicklung aus Perspektive verschiedener (Sub-)Disziplinen und Zugänge betrachtet und miteinander verknüpft werden. Neben einer historisch orientierten Inklusionsforschung, mit der Fragen möglicher Anknüpfungspunkte, Pfadabhängigkeiten oder Zäsuren bearbeitet werden, widmen sich die Beiträge des Bandes u.a. der Analyse des Status quo schulischer Inklusion, z.B. hinsichtlich relevanter Merkmale inklusionsorientierten Unterrichts oder möglicher Grenzen der Inklusionsforschung und -implementierung. Zudem werden Zukunftsperspektiven aus gegenwärtigen wissenschaftlichen Diskursen und Erkenntnissen abgeleitet

    Wir tanzen mit Bällen – Entwicklung und Förderung der Gestaltungskompetenz bei Schülerinnen und Schülern der Grundschule.

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    Kastrup V, Böer D. Wir tanzen mit Bällen – Entwicklung und Förderung der Gestaltungskompetenz bei Schülerinnen und Schülern der Grundschule. In: Roth A-C, Balz E, Frohn J, Neumann P, eds. Kompetenzorientiert Sport unterrichten – Grundlagen, Befunde, Beispiele. Forum Sportpädagogik. Vol 4. Aachen: Shaker Verlag; 2012: 173-183

    Identification and Analysis of Expression of Novel MicroRNAs of Murine Gammaherpesvirus 68▿ †

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    Murine gammaherpesvirus 68 (MHV-68) is closely related to Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) and provides a small-animal model with which to study the pathogenesis of gammaherpesvirus (γHV) infections. To completely explore the potential of the MHV-68 system for the investigation of γHV microRNAs (miRNAs), it would be desirable to know the number and expression patterns of all miRNAs encoded by MHV-68. By deep sequencing of small RNAs, we systematically investigated the expression profiles of MHV-68 miRNAs in both lytically and persistently infected cells. In addition to the nine known MHV-68 miRNAs, we identified six novel MHV-68 miRNA genes and analyzed the expression levels of all MHV-68 miRNAs. Furthermore, we also characterized the cellular miRNA expression signatures in MHV-68-infected versus noninfected NIH 3T3 fibroblasts and in 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-treated versus nontreated S11 cells. We found that mmu-mir-15b and mmu-mir-16 are highly upregulated upon MHV-68 infection of NIH 3T3 cells, indicating a potential role for cellular miRNAs during MHV-68 infection. Our data will aid in the full exploration of the functions of γHV miRNAs

    Anomalous temperature dependence of multiple Andreev reflections in a topological insulator Josephson junction

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    As a promising platform for unconventional superconductivity, Josephson junctions (JJs) of tetradymite topological insulators (TIs) and s-wave superconductors have been investigated in recent years. This family of TI materials, however, often suffers from spurious bulk transport, which hampers the observation of the exotic physics of their topological surface states. Thus, disentangling the transport mechanism of bulk and surface contributions in TI JJs is of high importance when investigating proximity induced superconductivity in those crystals. In this work, we add to the insights regarding these contributions by studying the temperature-dependent behaviour of a Bi2Te3-based JJ with transparent interfaces. In electrical transport measurements, we investigate differential conductance spectra of multiple Andreev reflections (MARs) and find a qualitative temperature-dependent change from peak features at low temperatures to dip features at higher ones. The observation of both kind of MAR patterns in a single JJ suggests contributions of diffusive bulk and ballistic surface states and links to a similar finding in the temperature dependence of the critical current. Our work advances the research of induced superconductivity in TIs and offers new avenues to study the induced superconductivity in the topological surface states of these materials

    Exploring the effects of dietary inulin in rainbow trout fed a high-starch, 100% plant-based diet

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    Abstract Background High dietary carbohydrates can spare protein in rainbow trout (Oncorhynchus mykiss) but may affect growth and health. Inulin, a prebiotic, could have nutritional and metabolic effects, along with anti-inflammatory properties in teleosts, improving growth and welfare. We tested this hypothesis in rainbow trout by feeding them a 100% plant-based diet, which is a viable alternative to fishmeal and fish oil in aquaculture feeds. In a two-factor design, we examined the impact of inulin (2%) as well as the variation in the carbohydrates (CHO)/plant protein ratio on rainbow trout. We assessed the influence of these factors on zootechnical parameters, plasma metabolites, gut microbiota, production of short-chain fatty acids and lactic acid, as well as the expression of free-fatty acid receptor genes in the mid-intestine, intermediary liver metabolism, and immune markers in a 12-week feeding trial. Results The use of 2% inulin did not significantly change the fish intestinal microbiota, but interestingly, the high CHO/protein ratio group showed a change in intestinal microbiota and in particular the beta diversity, with 21 bacterial genera affected, including Ralstonia, Bacillus, and 11 lactic-acid producing bacteria. There were higher levels of butyric, and valeric acid in groups fed with high CHO/protein diet but not with inulin. The high CHO/protein group showed a decrease in the expression of pro-inflammatory cytokines (il1b, il8, and tnfa) in liver and a lower expression of the genes coding for tight-junction proteins in mid-intestine (tjp1a and tjp3). However, the 2% inulin did not modify the expression of plasma immune markers. Finally, inulin induced a negative effect on rainbow trout growth performance irrespective of the dietary carbohydrates. Conclusions With a 100% plant-based diet, inclusion of high levels of carbohydrates could be a promising way for fish nutrition in aquaculture through a protein sparing effect whereas the supplementation of 2% inulin does not appear to improve the use of CHO when combined with a 100% plant-based diet
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