1,721,027 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
[Xenotransplantation of hDAF-transgenic swine hearts]
No full textHearts of transgenic pigs expressing a human regulator of complement activation, decay accelerating factor (hDAF), were transplanted either heterotopically into the abdomen of cynomolgus monkeys or orthotopically into baboons. None of these transgenic hearts was hyperacutely rejected. Immunosuppression with a combination of cyclosporine A, cyclophosphamide and steroids produced a maximum survival of 62 days (median 40 days) in the heterotopic model. Transgenic hearts transplanted into the orthotopic position allowed a maximum survival of 9 days (median 2.5 days). A more effective and less toxic immunosuppressive protocol for the prevention of accelerated xenograft rejection is the subject of ongoing research. The use of organs from transgenic pigs may help to solve the problem of donor shortage in clinical allotransplantation
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
The control of hyperacute rejection by genetic engineering of the donor species
No full textActivation of endogenous complement is inhibited both in the soluble phase and at the membrane surface by a group of structurally similar proteins. A possible solution to hyperacute rejection is to produce donor animals transgenic for human complement regulators. Mouse cells expressing the human complement regulatory proteins decay accelerating factor (DAF) or membrane cofactor protein (MCP) were produced both by hybridomatechnology and by transfection with the appropriate cDNAs. The expression of either or both of these products protected the mouse cell from lysis by human (though not rabbit)complement in the presence of naturally occurring human anti-mouse antibody. This effect could be abrogated by the addition of monoclonal antibody against DAF or MCP. Hyperacute rejection of discordant organ xenografts is mediated by human complement. A 6.5 kilobase minigene for DAF has been microinjected into porcine fertilised ova. Forty-five pigs transgenic for human DAF have been produced. of these, 65% transcribe message. The amount of message produced varied substantially from animal to animal and was independent of copy number integrated. Expression of human DAF on the porcine lymphocyte surface could be detected and this was able to downregulate human complement activation. Amounts of protein expressed on different tissues varied both from pig to pig and within animals from tissue to tissue. The pigs grow and develop normally with no evidenceof ill effects due to possession of the transgene. © 1955 Royal College of Ophthalmologists
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