1,720,992 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
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
L’ecotomografia nei tumori epatici primitivi. Possibilità, limiti e rapporti con l’arteriografia
No full textIs CT scan monitoring useful in patients with epithelial ovarian cancer and follow-up negative CA 125 serum levels?
No full textWe retrospectively reviewed our series of ovarian cancers to assess the benefit of routine follow-up abdominal computer tomography (CT) scans in asymptomatic patients with CA 125 levels 35 U/ml prior to surgery or initial chemotherapy, and complete routine follow-up. Fifty-two patients (75%) satisfied the inclusion criteria. After surgery, 32 of the 52 CA 125 positive patients (61%) showed a decrease in CA 125 levels; 10 other patients showed a negativity of CA 125 after cisplatinum polychemotherapy. After a median time of 49 months (range 16-117 months), 9 of the 42 patients (21%) developed a relapse. The overall CA 125 sensitivity at the time of relapse was 78%, with a specificity of 94%; the sensitivity for early detection of relapses was 70%. Two-hundred and seventy-six abdominal and pelvic CT scans were performed and 8 were positive for tumor relapse, with an overall sensitivity of 89%. The sensitivity of CT scans was 33% for early detection of relapses. The routine performance of follow-up CT scans did not significantly improve the overall detection of early relapses in ovarian carcinoma. A longitudinal monitoring of serum CA 125 is a reliable method of follow-up. Abdominal and pelvic CT scans should be performed in patients who, after a period in which they have been classified as not having evidence of disease with normal CA 125 serum levels, show elevated and rising CA 125, with the aim of finding and characterizing relapses
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