1,720,967 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
Hemophilia, how will end the story? [Emofilia, come si concluderà la storia?]
No full textHemophilia A (HA) and B (HB) are the most frequent inherited bleeding disorders caused by defects in the F8C and F9 genes that encode coagulation factor VIII and factor IX, respectively. Both HA and HB are X-linked recessive diseases and have an incidence of 1:5000 and 1:30,000 males, respectively. The diagnosis is based on normal prothrombin time, altered activated partial thromboplastin time and reduced activity of factor VIII or factor IX in plasma. Furthermore, laboratory contributes to identify the inhibitor (an immunoglobulin against the factor that some hemophilic patients develop during therapy) and to reveal acquired hemophilia. Carrier females of HA and HB are tipically asymptomatic and can be identified only by molecular analysis; their evaluation is important, as one third of cases of hemophilia is due to novel mutations and in these cases the mother (and consanguineous females) of the proband have no risk to be carrier. Both diseases are due to a myriad of different mutations (mostly private), so that the molecular diagnosis is based on scanning techniques or gene sequencing. Given the number of hemophilic patients that experience severe perinatal complications, high-risk couples usually require prenatal diagnosis. We revise here our experience on 50 prenatal diagnoses of hemophilia. The clinical heterogeneity of hemophilic patients prompted many groups to study prothrombotic gene variants in these subjects to investigate whether such variants modify the clinical expression of disease. Finally, therapy (using recombinant factors) and, in a near future, gene therapy will change the natural history of hemophilic patients
Hemophilia, how will end the story? [Emofilia, come si concluderà la storia?]
No full textHemophilia A (HA) and B (HB) are the most frequent inherited bleeding disorders caused by defects in the F8C and F9 genes that encode coagulation factor VIII and factor IX, respectively. Both HA and HB are X-linked recessive diseases and have an incidence of 1:5000 and 1:30,000 males, respectively. The diagnosis is based on normal prothrombin time, altered activated partial thromboplastin time and reduced activity of factor VIII or factor IX in plasma. Furthermore, laboratory contributes to identify the inhibitor (an immunoglobulin against the factor that some hemophilic patients develop during therapy) and to reveal acquired hemophilia. Carrier females of HA and HB are tipically asymptomatic and can be identified only by molecular analysis; their evaluation is important, as one third of cases of hemophilia is due to novel mutations and in these cases the mother (and consanguineous females) of the proband have no risk to be carrier. Both diseases are due to a myriad of different mutations (mostly private), so that the molecular diagnosis is based on scanning techniques or gene sequencing. Given the number of hemophilic patients that experience severe perinatal complications, high-risk couples usually require prenatal diagnosis. We revise here our experience on 50 prenatal diagnoses of hemophilia. The clinical heterogeneity of hemophilic patients prompted many groups to study prothrombotic gene variants in these subjects to investigate whether such variants modify the clinical expression of disease. Finally, therapy (using recombinant factors) and, in a near future, gene therapy will change the natural history of hemophilic patients
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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