1,720,982 research outputs found
Interaction of seminal plasma proteins with cell surface antigens: presence of a CD4-binding glycoprotein in human seminal plasma.
No full textWe report in this paper the presence in the human seminal plasma of a glycoprotein capable of binding to CD4, a surface antigen expressed on the surface of T-cells, macrophages, and sperm cells, which acts as a coreceptor in antigen-mediated T-cell activation and as a receptor for the AIDS virus, HIV-1. This protein, namely gp17 (apparent MW = 17,500 Da), was purified by affinity chromatography and characterized by SDS/PAGE analysis. Its binding to CD4 was inhibited by anti-CD4 mAbs directed against V1, a region of CD4 implicated in the binding to MHC class II antigens and to the HIV-1 envelope protein gp120, but not by mAbs directed against other CD4 determinants. The presence of a CD4-masking factor in human seminal plasma may be relevant to the modulation of maternal immunity at insemination and to the control of sexual transmission of HIV-1
Relative ratios of Lactoferrin, Albumin and Acid Phosphatase seminal levels as sperm quality markers in fertile and infertile men.
No full textHuman seminal plasma proteins from fertile and infertile men were fractionated by electrophoresis. The amounts of three Coomassie-stained protein bands were measured by densitometry. Their relative ratios were constant in normospermic men but varied in the infertile patients. Laboratory manipulation of the semen was shown not to affect the protein ratios as observed after liquefaction, incubation at various temperatures, and storage at -20 degrees C. The three proteins were purified by chromatographic techniques and identified as lactoferrin, albumin, and acid phosphatase by electrophoresis, high-pressure liquid chromatography, and enzyme assays. The use of these proteins to evaluate the contributions of different fluids to seminal plasma is discussed
Relative ratios of Lactoferrin, Albumin and Acid Phosphatase seminal levels as sperm quality markers in fertile and infertile men.
No full textHuman seminal plasma proteins from fertile and infertile men were fractionated by electrophoresis. The amounts of three Coomassie-stained protein bands were measured by densitometry. Their relative ratios were constant in normospermic men but varied in the infertile patients. Laboratory manipulation of the semen was shown not to affect the protein ratios as observed after liquefaction, incubation at various temperatures, and storage at -20 degrees C. The three proteins were purified by chromatographic techniques and identified as lactoferrin, albumin, and acid phosphatase by electrophoresis, high-pressure liquid chromatography, and enzyme assays. The use of these proteins to evaluate the contributions of different fluids to seminal plasma is discussed
Interaction of seminal plasma proteins with cell surface antigens: presence of a CD4-binding glycoprotein in human seminal plasma.
No full textWe report in this paper the presence in the human seminal plasma of a glycoprotein capable of binding to CD4, a surface antigen expressed on the surface of T-cells, macrophages, and sperm cells, which acts as a coreceptor in antigen-mediated T-cell activation and as a receptor for the AIDS virus, HIV-1. This protein, namely gp17 (apparent MW = 17,500 Da), was purified by affinity chromatography and characterized by SDS/PAGE analysis. Its binding to CD4 was inhibited by anti-CD4 mAbs directed against V1, a region of CD4 implicated in the binding to MHC class II antigens and to the HIV-1 envelope protein gp120, but not by mAbs directed against other CD4 determinants. The presence of a CD4-masking factor in human seminal plasma may be relevant to the modulation of maternal immunity at insemination and to the control of sexual transmission of HIV-1
Multilayer Neural Networks for Speaker Normalization
No full textIn this work, the speaker normalisation problem is afforded by two different techniques. The first one is based non a linear transformation of acoustic data. The second is based on a neural network trained using the back propagation algorithm. Two metric spaces for the speakers data representation are used. These are shown to improve the normalization performance. A Dynamic Time Warping recognition system is used to test the two approaches and compare the recognition performance
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
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
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