1,720,974 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
CalDAG-GEFI deficiency protects mice in a novel model of FcγRIIA-mediated thrombosis and thrombocytopenia
Full text linkAbstractPlatelet activation via Fcγ receptor IIA (FcγRIIA) is a critical event in immune-mediated thrombocytopenia and thrombosis syndromes (ITT). We recently identified signaling by the guanine nucleotide exchange factor CalDAG-GEFI and the adenosine diphosphate receptor P2Y12 as independent pathways leading to Rap1 small GTPase activation and platelet aggregation. Here, we evaluated the contribution of CalDAG-GEFI and P2Y12 signaling to platelet activation in ITT. Mice transgenic for the human FcγRIIA (hFcR) and deficient in CalDAG-GEFI−/− (hFcR/CDGI−/−) were generated. Compared with controls, aggregation of hFcR/CDGI−/− platelets or P2Y12 inhibitor-treated hFcR platelets required more than 5-fold and approximately 2-fold higher concentrations of a FcγRIIA stimulating antibody against CD9, respectively. Aggregation and Rap1 activation were abolished in P2Y12 inhibitor-treated hFcR/CDGI−/− platelets. For in vivo studies, a novel model for antibody-induced thrombocytopenia and thrombosis was established. FcγRIIA-dependent platelet thrombosis was induced by infusion of Alexa750-labeled antibodies to glycoprotein IX (CD42a), and pulmonary thrombi were detected by near-infrared imaging technology. Anti-GPIX antibodies dose-dependently caused thrombocytopenia and pulmonary thrombosis in hFcR-transgenic but not wild-type mice. CalDAG-GEFI-deficient but not clopidogrel-treated hFcR-transgenic mice were completely protected from ITT. In summary, we established a novel mouse model for ITT, which was used to identify CalDAG-GEFI as a potential new target in the treatment of ITT.</jats:p
Chemokine Fractalkine mediates leukocyte recruitment to inflammatory endothelial cells in flowing whole blood
No full textDas Chemokin Fractalkine (CX3CL1) wird unter anderem auf entzündlich veränderten Endothelzellen exprimiert. Das Ziel der vorliegenden Dissertation war es daher, die Rolle des Chemokins Fractalkine für die Rekrutierung von Leukozyten an entzündlich veränderte Endothelzellen unter arteriellen Scherkräften, wie sie in atherosklerotisch erkrankten Arterien vorzufinden sind, zu untersuchen. Es konnte gezeigt werden, dass Fractalkine die Leukozytenadhäsion an entzündete Endothelzellen unter arteriellen Scherraten fördert. Zusätzlich konnte gezeigt werden, dass Thrombozyten zwingend notwendig für die Rekrutierung von Leukozyten an entzündlich verändertes Endothel unter arteriellen Flussraten waren. Thrombozyten exprimieren den Fractalkine-Rezeptor (CX3CR1) und die vorliegende Arbeit zeigt, dass eine Degranulation und folgende Oberflächenexpression von P-Selektin sowie eine Thrombozyten-Leukozyten-Interaktion durch Fractalkine induziert wird. Es konnte ferner gezeigt werden, dass die durch Fractalkine induzierte Expression von P-Selektin auf Thrombozyten wichtig für die Leukozytenadhäsion auf inflammatorischem Endothel unter arteriellen Flussbedingungen ist.The membrane-bound chemokine fractalkine (CX3CL1) is expressed on various cell types including activated endothelial cells and has been implicated in the inflammatory process of atherosclerosis. The aim of this doctoral thesis was to dissect the role of fractalkine in leukocyte recruitment to the inflamed endothelium under arterial shear forces.
We addressed leukocyte adhesion to TNF-α/IFN-γ−stimulated endothelial cells (HUVEC) under arterial shear conditions using a flow chamber system. TNF-α/IFN-γ−stimulated HUVECs abundantly expressed (CX3CL1)and promoted strong leukocyte accumulation. Firm adhesion of leukocytes was reduced by approximately 40% by a function blocking anti-fractalkine antibody or by an antibody directed against (CX3CR1). Surprisingly, platelets were strictly required for fractalkine-induced leukocyte adhesion to the inflamed endothelium. Correspondingly, specific inhibition of platelet adhesion by interference with platelet β3 integrins (c7E3) or platelet glycoprotein (GP)Ibα significantly reduced leukocyte accumulation on inflamed endothelial cells, indicating that in the absence of platelets endothelial fractalkine is not sufficient to induce leukocyte recruitment. Platelets express the fractalkine receptor (CX3CR1) and we show here using flow cytometry that platelet degranulation and surface expression of P-selectin are induced in response to both soluble and membrane-bound fractalkine thereby promoting platelet-leukocyte aggregate formation. Further, using stable fractalkine transfectants we demonstrate that fractalkine-induced platelet P-selectin exposure is critical for leukocyte adhesion.
Fractalkine expressed by inflamed endothelial cells triggers P-selectin exposure on adherent platelets thereby initiating the local accumulation of leukocytes, an essential step in the development of atherosclerotic lesions
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
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
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
- …
