1,721,048 research outputs found

    Association of Fc?RIIa (CD32a) with lipid rafts regulates ligand binding activity

    No full text
    Binding of Igs to myeloid cells via FcR is a key event in the control of innate and acquired immunity. FcRIIa (CD32a) is a receptor for multivalent IgG expressed predominantly by myeloid cells, and its association with microdomains rich in cholesterol and sphingolipids, termed as lipid rafts, has been reported to be essential for efficient signaling. However, for many myeloid cell types, ligand binding to CD32a is suppressed by as yet undefined mechanisms. In this study, we have examined the role of CD32a-lipid raft interactions in the regulation of IgG binding to CD32a. Disruption of lipid raft structure following depletion or sequestration of membrane cholesterol greatly inhibited CD32a-mediated IgG binding. Furthermore, specific CD32a mutants, which show reduced association with lipid rafts (A224S and C241A), displayed decreased levels of IgG binding compared with wild-type CD32a. In contrast, constitutively lipid raft-associated CD32a (GPI-anchored CD32a) exhibited increased capacity for IgG binding compared with the full-length transmembrane CD32a. Our findings clearly suggest a major role for lipid rafts in the regulation of IgG binding and, more specifically, that suppression of CD32a-mediated IgG binding in myeloid cells is achieved by receptor exclusion from lipid raft membrane microdomains

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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 link
    We 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 link
    We 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

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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

    A study of platelets and the endothelium in idiopathic pulmonary fibrosis

    Full text link
    Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease associated with significant morbidity and early mortality. Despite this, the pathogenesis remains poorly understood and there is no effective disease modifying treatment. Epidemiological studies demonstrate an association between IPF and vascular disease. Platelets and the endothelium play an important role in maintaining vascular integrity, patency and function. In addition to their role in haemostasis, platelets have significant inflammatory and pro-fibrotic potential. Platelets and the lung have a close relationship in physiology and in disease however the role of platelets in IPF has not previously been investigated.In this thesis we investigate the link between IPF and vascular disease and consider a potential pathogenic role of platelets in IPF. We do this through the following series of experiments: (1) investigation of the platelet endothelial cell adhesion molecule-1 single nucleotide polymorphisms in IPF and controls; (2) assessment of markers of platelet activation in IPF and controls; (3) investigation of the effect of IPF plasma on control platelets; (4) assessment of platelet function by measurement of platelet-endothelial cell adhesion; and (5) evaluation of plasma markers of endothelial activation and fibrinolysis in IPF.We demonstrate that IPF patients exhibit increased platelet reactivity and that this can be reproduced in control platelets following incubation in IPF plasma suggesting that a plasma factor is responsible for this phenomenon. In addition, we show that the increased platelet reactivity in IPF is associated with an increased propensity to adhere to vascular endothelium confirming abnormal platelet function in IPF patients and suggesting a potential pathogenic mechanism. We do not demonstrate any difference in plasma levels of endothelial activation markers or fibrinolysis between IPF patients and controls. Similarly, we find no clinically significant difference in the prevalence of the PECAM-1 polymorphisms in IPF and controls
    corecore