Three-dimensional architecture and biogenesis of membrane structures associated with hepatitis C virus replication

All positive strand RNA viruses are known to replicate their genomes in close association with intracellular membranes. In case of the hepatitis C virus (HCV), a member of the family Flaviviridae, infected cells contain accumulations of vesicles forming a membranous web (MW) that is thought to be the site of viral RNA replication. However, little is known about the biogenesis and three-dimensional structure of the MW. In this study we used a combination of immunofluorescence- and electron microscopy (EM)-based methods to analyze the membranous structures induced by HCV in infected cells. We found that the MW is derived primarily from the endoplasmic reticulum (ER) and contains markers of rough ER as well as markers of early and late endosomes, COP vesicles, mitochondria and lipid droplets (LDs). The main constituents of the MW are single and double membrane vesicles (DMVs). The latter predominate and the kinetic of their appearance correlates with kinetics of viral RNA replication. DMVs are induced primarily by NS5A whereas NS4B induces single membrane vesicles arguing that MW formation requires the concerted action of several HCV replicase proteins. Three-dimensional reconstructions identify DMVs as protrusions from the ER membrane into the cytosol, frequently connected to the ER membrane via a neck-like structure. In addition, late in infection multi-membrane vesicles become evident, presumably as a result of a stress-induced reaction. Thus, the morphology of the membranous rearrangements induced in HCV-infected cells resemble those of the unrelated picorna-, corona- and arteriviruses, but are clearly distinct from those of the closely related flaviviruses. These results reveal unexpected similarities between HCV and distantly related positive-strand RNA viruses presumably reflecting similarities in cellular pathways exploited by these viruses to establish their membranous replication factories

Robust excitation of C-band quantum dots for quantum communication

Building a quantum internet requires efficient and reliable quantum hardware, from photonic sources to quantum repeaters and detectors, ideally operating at telecommunication wavelengths. Thanks to their high brightness and single-photon purity, quantum dot (QD) sources hold the promise to achieve high communication rates for quantum-secured network applications. Furthermore, it was recently shown that excitation schemes, such as longitudinal acoustic phonon-assisted (LA) pumping, provide security benefits by scrambling the coherence between the emitted photon-number states. In this work, we investigate further advantages of LA-pumped quantum dots with emission in the telecom C-band as a core hardware component of the quantum internet. We experimentally demonstrate how varying the pump energy and spectral detuning with respect to the excitonic transition can improve quantum-secured communication rates and provide stable emission statistics regardless of network-environment fluctuations. These findings have significant implications for general implementations of QD single-photon sources in practical quantum communication networks

MyD88 signalling in colonic mononuclear phagocytes drives colitis in IL-10-deficient mice

Commensal bacterial sensing by Toll-like receptors is critical for maintaining intestinal homeostasis, but can lead to colitis in the absence of interleukin-10. Although Toll-like receptors are expressed in multiple cell types in the colon, the cell type(s) responsible for the development of colitis are currently unknown. Here we generated mice that are selectively deficient in MyD88 in various cellular compartments in an interleukin-10[superscript −/−] setting. Although epithelial expression of MyD88 was dispensable, MyD88 expression in the mononuclear phagocyte compartment was required for colitis development. Specifically, phenotypically distinct populations of colonic mononuclear phagocytes expressed high levels of interleukin-1β, interleukin-23 and interleukin-6, and promoted T-helper 17 responses in the absence of interleukin-10. Thus, gut bacterial sensing through MyD88 in mononuclear phagocytes drives inflammatory bowel disease when unopposed by interleukin-10.Howard Hughes Medical InstituteNational Institutes of Health (U.S.) (NIH grant DK071754)National Institutes of Health (U.S.) (NIH grant AI046688)National Institutes of Health (U.S.) (NIH grant AI055502)National Institutes of Health (U.S.) (NIH grant RO1OD011141)National Institutes of Health (U.S.) (Training grant)National Cancer Institute (U.S.) (Irvington Fellowship

Früherkennung von Fruchtbarkeitsstörungen

Zur Früherkennung von Fruchtbarkeitsstörungen und Eutererkrankungen beim Milchrind wurden Modelle erarbeitet, um Zwischentragezeiten bzw. Mastitiserkrankungen vorhersagen zu können. Die Früherkennung basierte auf den anfallenden Informationen rund um das Management einer sächsischen Milchviehherde. Im Fruchtbarkeitsmodell konnten hohe Sensitivitäten bei Fehlerraten um 20 Prozent erreicht werden. Im Eutererkrankungsmodell lagen die Fehlerraten bei über 50 Prozent. Daher sind die Frühwarnsysteme noch nicht praxisreif

Impacts of climate change on plant diseases – opinions and trends

There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

Evaluation der Berufseinstiegsbegleitung nach § 421s SGB III: Zwischenbericht 2011

Die Anforderungen an Schülerinnen und Schüler zwei Jahre vor ihrem Schulabschluss sind hoch. Schulisch sind sie mit vielen Prüfungen gefordert. Daneben müssen sie Bewerbungen für Ausbildungsplätze schreiben. Wenn es zum Bewerbungsgespräch kommt, stehen sie vor einer unbekannten Situation. Viele sind unsicher darüber, wie es nach der Schule weitergeht. Das Berufsleben - später meist selbstverständlich - ist die große Unbekannte. In dieser Phase hilft die Berufseinstiegsbegleitung nach dem Arbeitsförderungsrecht derzeit in einer modellhaften Erprobung an rund 1.000 Schulen denjenigen, die besondere Schwierigkeiten beim Schulabschluss und beim Übergang in die berufliche Zukunft haben. Bisher wurden dabei rund 37.000 Schülerinnen und Schülern durch die Bundesagentur für Arbeit gefördert. Die begleitende Wirkungsforschung (Evaluation) zeigt nun, dass sich bei den Teilnehmenden leichte Verbesserungen der Noten in Mathematik, Deutsch und Englisch zeigen. Von denjenigen, die die Schule „in Begleitung“ verlassen haben, haben 22,8 % eine betriebliche und 5,1 % eine schulische Berufsausbildung begonnen. Vergleichszahlen zu Übergängen von der Schule in den Beruf von jungen Menschen "ohne entsprechende Begleitung" liegen noch nicht vor. Nach der Schule verteilen sich die Schülerinnen und Schüler auf verschiedene Betriebe, Berufsschulen und andere Einrichtungen. Für die Tätigkeit der Berufseinstiegsbegleiterinnen und -begleiter stellt dies eine räumliche und eine organisatorische Herausforderung dar. Denn die Berufseinstiegsbegleitung endet in der Berufsausbildung normalerweise erst nach sechs Monaten. Damit soll die kritische Anfangsphase, in der die meisten Abbrüche stattfinden, stabilisiert werden. Die bisherigen positiven Erfahrungen mit der Berufseinstiegsbegleitung haben die Bundesregierung dazu veranlasst, im Entwurf eines Gesetzes zur Verbesserung der Eingliederungschancen am Arbeitsmarkt die Entfristung der Berufseinstiegsbegleitung vorzuschlagen. Der Deutsche Bundestag hat dieses Gesetz am 23. September 2011 verabschiedet