1,720,968 research outputs found
Apoptosis: prospects for pharmacological manipulation of activated programmed cell death in immunological disease.
No full textApoptosis of lymphoid cells is an important process in regulating the development and maintenance of the immune system. In addition, apoptosis can be considered as the primary cause of a variety of diseases. The decision of a cell to undergo apoptosis or to proliferate can be influenced by several activating stimuli, as well as by the phenotype of the cell and its stage of activation. Consequently, apoptosis represents one feature of the multiple events that regulate a correct immune response. Here, we discuss the regulatory pathways responsible for the induction of apoptosis in normal and pathological conditions, and analyse the possible substances interfering with these pathways with particular attention to the levels at which these substances act
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
Differential susceptibility to monomeric HIV gp120-mediated apoptosis in antigen-activated CD4+ T cell populations.
No full textTo support the hypothesis that indirect mechanisms mediated by viral products like the HIV envelope glycoprotein gp120 could be responsible for T lymphocyte depletion in HIV infection, we developed a system in which the impairment of T cell functions could be investigated in vitro. In particular, we characterized the conditions that allow T lymphocytes repeatedly stimulated with an antigen to be sensitive or resistant to gp120-mediated apoptotic signals. To achieve this goal, a panel of antigen-specific CD4+ T cell clones and primary CD4+ T lymphocytes were treated for 2 and 18 h with saturating amounts of monomeric gp120 (without cross-linking with specific antibodies) and antigen-driven T cell proliferation and apoptosis were analyzed. We show that monomeric gp120 induces apoptosis only in T lymphocytes repeatedly stimulated with the antigen, that primary T lymphocytes are resistant to programmed cell death mediated by monomeric gp120, but are sensitive to anti-CD4 antibodies, and that gp120-mediated apoptosis is dependent on the period of time between the binding of gp120 to CD4 and the encounter with antigen. To investigate the different susceptibility to gp120 induced apoptosis of primary CD4+ and T cell clones further, the number of membrane CD4 molecules and their affinity for gp120, together with Bcl-2 and Fas expression, were studied. Our data suggest that a down-modulation of membrane CD4 together with high expression of the Bcl-2 gene and protein characterizes the susceptibility to apoptosis of gp120-treated cells. In conclusion, our results define the phenotypic features of T cells susceptible to HIV gp120-induced apoptosis and demonstrate that the same clonotype, depending on the activation state, may present a differential sensitivity to apoptosis induction.To support the hypothesis that indirect mechanisms mediated by viral products like the HIV envelope glycoprotein gp120 could be responsible for T lymphocyte depletion in HIV infection, we developed a system in which the impairment of T cell functions could be investigated in vitro. In particular, we characterized the conditions that allow T lymphocytes repeatedly stimulated with an antigen to be sensitive or resistant to gp120‐mediated apoptotic signals. To achieve this goal, a panel of antigen‐specific CD4+ T cell clones and primary CD4+ T lymphocytes were treated for 2 and 18 h with saturating amounts of monomeric gp120 (without cross‐linking with specific antibodies) and antigen‐driven T cell proliferation and apoptosis were analyzed. We show that monomeric gp120 induces apoptosis only in T lymphocytes repeatedly stimulated with the antigen, that primary T lymphocytes are resistant to programmed cell death mediated by monomeric gp120, but are sensitive to anti‐CD4 antibodies, and that gp120‐mediated apoptosis is dependent on the period of time between the binding of gp120 to CD4 and the encounter with antigen. To investigate the different susceptibility to gp120 induced apoptosis of primary CD4+ and T cell clones further, the number of membrane CD4 molecules and their affinity for gp120, together with Bcl‐2 and Fas expression, were studied. Our data suggest that a down‐modulation of membrane CD4 together with high expression of the Bcl‐2 gene and protein characterizes the susceptibility to apoptosis of gp120‐treated cells. In conclusion, our results define the phenotypic features of T cells susceptible to HIV gp120‐induced apoptosis and demonstrate that the same clonotype, depending on the activation state, may present a differential sensitivity to apoptosis induction. Copyright © 1995 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinhei
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
Phosphatidylinositol 4-phosphate 5-kinase α: a key modulator of CD28 costimulatory signals
No full textkoamabayili/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
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