124 research outputs found

    Wikipedia als Referenzorgan

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    Wikipedia wird inzwischen von vielen Nutzern regelmäßig als Nachschlagewerk genutzt. Aufgrund des offenen Charakters der Online-Enzyklopädie, bei der sich jeder direkt beteiligen kann, ist jedoch zusätzliche Medienkompetenz notwendig, um die Qualität einzelner Wikipedia-Artikel einschätzen zu können. Im Vortrag sollen Methoden zur Beurteilung von Wikipedia-Artikeln dargestellt und die Frage beleuchtet werden, unter welchen Umständen Wikipedia als Referenzorgan geeignet ist

    WikiCite als kollaborativer Ansatz für offene Zitationsdaten

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    WikiCite ist eine Initiative zur Erstellung einer offenen bibliographischen Datenbank für alle Wikimedia-Projekte und darüber hinaus als Grundlage für freies Wissen allgemein. Die Umsetzung im Rahmen der freien Wissensdatenbank Wikidata läuft spätestens seit 2016. Inzwischen sind bereits bibliographische Angaben zu über 10 Millionen Publikationen verfügbar und werden im Sinne des Wiki-Prinzips kollaborativ erweitert. Ein besonderer Vorteil der Erschließung in Wikidata besteht in der Möglichkeit Publikationsdaten mit Personen, Schlagworten und anderen Publikationen zu verknüpfen. Diese Praxis hat viel mit bibliothekarischer Erschließung gemein und lässt sich durch Normdaten mit dieser verbinden, es gibt aber auch wesentliche Unterschiede und Besonderheiten.Zu den im Rahmen von WikiCite erfassten Informationen gehören auch Zitationsdaten, die zunehmend für bibliothekarische Anwendungen interessant werden. So lassen sich mit offenen Zitationsdaten die Recherchemöglichkeiten durch Kataloganreicherungen erweitern, Rankingverfahren von Suchergebnissen verbessern sowie transparente und replizierbare bibliometrische Analysen durchführen. Die Umsetzung ist bereits jetzt mit den für Wikidata bereitgestellten Techniken möglich.Der Vortrag soll am Beispiel offener Zitationsdaten eine Einführung in WikiCite geben und damit eine grundlegend neue Entwicklung bei der Erschließung von Publikationen aufzeigen

    Erfassung von Wissensorganisationssystemen in BARTOC - Ergebnis eines Projektseminars an der Hochschule Hannover

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    Das Basel Register of Thesauri, Ontologies & Classifications (BARTOC) hat sich innerhalb weniger Jahre mit mehr als 2.700 Einträgen zu einem umfangreichen Verzeichnis von Wissensorganisationssystemen entwickelt. Im Sommersemester 2017 wurde diese Entwicklung von einem Projektseminar mit Bachelor-Studierenden der Hochschule Hannover begleitet. Eine Revision und Erweiterung der Inhalte von BARTOC führte zu einer besseren Abdeckung ausgewählter Metadatenfelder. Darüber hinaus wurden verschiedene Statistiken, Informationsmaterialien und ein neues Logo erstellt

    A non-transmissible live attenuated SARS-CoV-2 vaccine

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    Live attenuated vaccines (LAVs) administered via the mucosal route may offer better control of the COVID-19 pandemic than non-replicating vaccines injected intramuscularly. Conceptionally, LAVs have several advantages, including presentation of the entire antigenic repertoire of the virus, and the induction of strong mucosal immunity. Thus, immunity induced by LAV could offer superior protection against future surges of COVID-19 cases caused by emerging SARS-CoV-2 variants. However, LAVs carry the risk of unintentional transmission. To address this issue, we investigated whether transmission of a SARS-CoV-2 LAV candidate can be blocked by removing the furin cleavage site (FCS) from the spike protein. The level of protection and immunity induced by the attenuated virus with the intact FCS was virtually identical to the one induced by the attenuated virus lacking the FCS. Most importantly, removal of the FCS completely abolished horizontal transmission of vaccine virus between cohoused hamsters. Furthermore, the vaccine was safe in immunosuppressed animals and showed no tendency to recombine in vitro or in vivo with a SARS-CoV-2 field strain. These results indicate that removal of the FCS from SARS-CoV-2 LAV is a promising strategy to increase vaccine safety and prevent vaccine transmission without compromising vaccine efficacy

    Early protective effect of a (“pan”) coronavirus vaccine (PanCoVac) in Roborovski dwarf hamsters after single-low dose intranasal administration

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    Introduction: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the danger posed by human coronaviruses. Rapid emergence of immunoevasive variants and waning antiviral immunity decrease the effect of the currently available vaccines, which aim at induction of neutralizing antibodies. In contrast, T cells are marginally affected by antigen evolution although they represent the major mediators of virus control and vaccine protection against virus-induced disease. Materials and methods: We generated a multi-epitope vaccine (PanCoVac) that encodes the conserved T cell epitopes from all structural proteins of coronaviruses. PanCoVac contains elements that facilitate efficient processing and presentation of PanCoVac-encoded T cell epitopes and can be uploaded to any available vaccine platform. For proof of principle, we cloned PanCoVac into a non-integrating lentivirus vector (NILV-PanCoVac). We chose Roborovski dwarf hamsters for a first step in evaluating PanCoVac in vivo. Unlike mice, they are naturally susceptible to SARS-CoV-2 infection. Moreover, Roborovski dwarf hamsters develop COVID-19-like disease after infection with SARS-CoV-2 enabling us to look at pathology and clinical symptoms. Results: Using HLA-A*0201-restricted reporter T cells and U251 cells expressing a tagged version of PanCoVac, we confirmed in vitro that PanCoVac is processed and presented by HLA-A*0201. As mucosal immunity in the respiratory tract is crucial for protection against respiratory viruses such as SARS-CoV-2, we tested the protective effect of single-low dose of NILV-PanCoVac administered via the intranasal (i.n.) route in the Roborovski dwarf hamster model of COVID-19. After infection with ancestral SARS-CoV-2, animals immunized with a single-low dose of NILV-PanCoVac i.n. did not show symptoms and had significantly decreased viral loads in the lung tissue. This protective effect was observed in the early phase (2 days post infection) after challenge and was not dependent on neutralizing antibodies. Conclusion: PanCoVac, a multi-epitope vaccine covering conserved T cell epitopes from all structural proteins of coronaviruses, might protect from severe disease caused by SARS-CoV-2 variants and future pathogenic coronaviruses. The use of (HLA-) humanized animal models will allow for further efficacy studies of PanCoVac-based vaccines in vivo

    Single-cell-resolved interspecies comparison shows a shared inflammatory axis and a dominant neutrophil-endothelial program in severe COVID-19

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    A key issue for research on COVID-19 pathogenesis is the lack of biopsies from patients and of samples at the onset of infection. To overcome these hurdles, hamsters were shown to be useful models for studying this disease. Here, we further leverage the model to molecularly survey the disease progression from time-resolved single-cell RNA sequencing data collected from healthy and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected Syrian and Roborovski hamster lungs. We compare our data to human COVID-19 studies, including bronchoalveolar lavage, nasal swab, and postmortem lung tissue, and identify a shared axis of inflammation dominated by macrophages, neutrophils, and endothelial cells, which we show to be transient in Syrian and terminal in Roborovski hamsters. Our data suggest that, following SARS-CoV-2 infection, commitment to a type 1- or type 3-biased immunity determines moderate versus severe COVID-19 outcomes, respectively

    D* Production in Deep Inelastic Scattering at HERA

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    This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel D+(D0Kπ+)π+D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ (+ c.c.) has been used in the study. The e+pe^+p cross section for inclusive D^{*\pm} production with 5<Q2<100GeV25<Q^2<100 GeV^2 and y<0.7y<0.7 is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {1.3<pT(D±)<9.01.3<p_T(D^{*\pm})<9.0 GeV and η(D±)<1.5| \eta(D^{*\pm}) |<1.5}. Differential cross sections as functions of p_T(D^{*\pm}), η(D±),W\eta(D^{*\pm}), W and Q2Q^2 are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and η\eta(D^{*\pm}), the charm contribution F2ccˉ(x,Q2)F_2^{c\bar{c}}(x,Q^2) to the proton structure function is determined for Bjorken xx between 2 \cdot 104^{-4} and 5 \cdot 103^{-3}.Comment: 17 pages including 4 figure

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde
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