1,720,962 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Modulation anti-viraler Signalwege durch herpesvirale Onkoproteine
Full text linkThe innate immune system detects pathogen-associated molecular patterns and immediately initiates
cytokine-based defense mechanisms. In the cytosol, viral DNA is recognized by the sensor protein
cGAS, whereas viral RNA is sensed by RIG-I. These receptors transmit signals to the adaptor proteins
STING and MAVS, respectively. The adaptors, to a variable extent, rely on TRAF proteins to transmit
signals to downstream kinases that activate, most prominently, IRF3 and NF-κB. The activated
transcription factors cooperate to induce the innate immune response characterized by IFN-β
production. Gamma-herpesviruses like the human Epstein-Barr virus (EBV) possess an oncogenic
potential that is mediated by their so-called oncoproteins. The primary EBV oncoprotein, LMP1, and
the closely related herpesvirus oncoprotein Tio interact with TRAFs to activate NF-κB. Based on the
shared signaling intermediates, this study addressed the hypothesis that Tio and LMP1 can interfere
with the cGAS-STING and RIG-I-MAVS pathways. Therefore, HEK293 wildtype and TRAF6
knockout cells were used for NF-κB, IRF3 and IFN-β-promoter reporter assays, IFN-β RT-qPCRs,
immunoblotting and immunoprecipitation analyses. Intracellular localization was studied by
immunofluorescence staining of HeLa cells.
Tio strongly enhanced STING-mediated IFN-β activation by amplifying the underlying NF-κB activity.
All effects of STING and Tio on IFN-β as well as NF-κB activity were TRAF6 dependent, whereas
IRF3 induction by STING was completely TRAF6 independent and unaffected by Tio. In the context of
MAVS signaling, Tio repressed IFN-β induction by decreasing the underlying IRF3 activity. This
impairment was again TRAF6 dependent. Mechanistically, Tio was found to detach TRAF6 from the
mitochondrial MAVS signaling complex, thereby disrupting the TBK1-induced IRF3 activation.
Modulation of MAVS signaling relied on Tio’s distinct TRAF6-binding motif, likely making Tio the
dominant interactor of TRAF6. LMP1 also enhanced STING signaling towards NF-κB and IFN-β
activation but restrained the concomitant IRF3 induction. The EBV oncoprotein LMP1 repressed
MAVS-mediated IRF3 activation and IFN-β induction more efficiently than Tio. Accordingly, the
relocation of TRAF6 from the mitochondrial signaling complex was also observed for LMP1,
indicating a conserved gamma-herpesviral mechanism. In addition, LMP1 was found to employ a
TRAF6-independent mechanism to repress IRF3 activation, and a TRAF6-dependent mechanism to
directly interfere with activated IRF3, possibly explaining the stronger repression relative to Tio.
Furthermore, LMP1 was detected in complex with IRF3, pointing at potential accessory mechanisms to
modulate IRF3 activity. Together, the results of this study highlight a novel function of herpesviral
oncoproteins as immune regulators, distinctly shaping host immune responses and possibly resulting in
a microenvironment beneficial for viral persistence. In terms of LMP1, these findings could contribute
towards a better understanding of the maintenance of EBV latencyDas angeborene Immunsystem detektiert Pathogen-assoziierte molekulare Muster und initiiert schnelle
Zytokin-basierte Abwehrmechanismen. So wird im Zytosol virale DNA durch den Sensor cGAS
erkannt, virale RNA durch RIG-I. Diese Rezeptoren vermitteln Signale an die Adaptorprotein STING
bzw. MAVS. Die Adaptoren sind in unterschiedlichem Mass von TRAF-Proteinen abhängig, um
Signale an nachgeordnete Kinasen weiterzuleiten. Diese Enzyme aktivieren insbesondere IRF3 und NF-
κB. Die aktivierten Transkriptionsfaktoren induzieren gemeinsam eine für die angeborene Immunantwort
typische IFN-β-Produktion. Gamma-Herpesviren wie das humane Epstein-Barr-Virus (EBV)
besitzen ein onkogenes Potential, das durch ihre sogenannten Onkoproteine vermittelt wird. Das
primäre EBV-Onkoprotein LMP1 und auch das nahe verwandte Tio-Protein interagieren mit TRAFs
um NF-κB zu aktiveren. Die gemeinsam genutzten Kofaktoren führten zur Hypothese, dass Tio und
LMP1 mit den cGAS-STING- und RIG-I-MAVS-Signalübertragungswegen interferieren. Daher
wurden in dieser Studie HEK293-Zellen (Wildtyp und TRAF6-knockout) verwendet für NF-κB-, IRF3-
und IFN-β-Promotor-Reporterassays, IFN-β RT-qPCRs, Immunoblot- und Immunopräzipitationsanalysen.
Die intrazelluläre Lokalikation wurde mittels Immunofluoreszenz-Färbung von HeLa-Zellen
überprüft.
Tio verstärkte die STING-vermittelte IFN-β-Aktivierung deutlich, speziell durch gesteigerte NF-κB
Aktivität. Alle Effekte von STING und Tio auf IFN-β und die NF-κB-Aktivität waren TRAF6-
abhängig, während die IRF3-Induktion durch STING komplett TRAF6-unabhängig und nicht von Tio
beeinflusst war. Dagegen reprimierte Tio im Zusammenhang mit MAVS die IFN-β-Induktion über eine
Verminderung der IRF3-Aktivität. Diese Reduktion war wieder TRAF6-abhängig. Begleitend zeigte
sich, dass Tio TRAF6 aus dem mitochondrialen MAVS-Signalkomplex herauslöste und die TBK1-
induzierte IRF3-Aktivierung unterbrochen wurde. Die MAVS-modulierende Wirkung basierte auf Tio’s
speziellem TRAF6-Bindemotiv, welches Tio vermutlich zum dominanten TRAF6-Interaktor macht.
LMP1 verstärkte ebenfalls die NF-κB- und IFN-β-Aktitivierung durch STING, beschränkte jedoch die
gleichzeitige IRF3-Induktion. Das EBV-Onkoprotein reprimierte die MAVS-vermittelte IRF3-
Aktivierung und IFN-β-Induktion wesentlich effizienter als Tio. Dementsprechend führte auch LMP1
zu einer Entfernung von TRAF6 aus dem mitochondrialen Signalkomplex, was für einen konservierten
gamma-herpesviralen Mechanismus spricht. Die verstärkte Repression durch LMP1 ließe sich dadurch
erklären, dass LMP1 zusätzlich über einen TRAF6-unabhängigen Weg die IRF3-Aktivierung und über
einen TRAF6-abhängigen Weg das bereits aktivierte IRF3 hemmte. Außerdem wurde LMP1 im
Komplex mit IRF3 nachgewiesen, was auf weitere Mechanismen zur Modulation von IRF3 hindeutet.
Insgesamt wurde in dieser Studie die bisher unbekannte Funktion herpesviraler Onkoproteine als
Immunregulatoren beschrieben, welche die Immunantwort des Wirtes formen und eine für die virale
Persistenz vorteilhafte Mikroumgebung schaffen könnten. Im Hinblick auf LMP1 könnte sich daraus
ein Beitrag zum besseren Verständnis der EBV-Latenz ergeben
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Peripheral T-cell lymphoma in herpesvirus saimiri-infected tamarins: Tumor cell lines reveal subgroup-specific differences
No full textEfficiency of lymphoma induction by herpesvirus saimiri (HVS) isolates correlates with the genetically defined viral subgroups A, B, and C. To compare subgroup-specific effects, highly susceptible tamarins were infected with HVS strain A-11, B-SMHI, or C-488. All animals developed T-cell lymphomas indistinguishable with respect to clinical, pathological, and virological parameters. Ex vivo T-cell lines were established readily from the HVS C-488 animal, less efficiently in the presence of HVS A-11, and from only a single HVS B-SMHI sample. These cultivated cells revealed strain-specific biochemical characteristics. HVS A-11 strongly induced the expression of tyrosine kinase Lyn. HVS C-488 led to the activation of STAT3, which is most likely linked to the association of virus-encoded Tip with tyrosine kinase Lck. The lack of these activities in HVS B-SMHI-transformed cells may correlate with the reduced oncogenic phenotype of this virus in species other than tamarins. (C) 2002 Elsevier Science (USA)
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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