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Laryngeal carcinoma showing multidirectional epithelial neuroendocrine and sarcomatous differentiation
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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
Evaluation of a new enzyme immunoassay for detecting Helicobacter pylori in feces: a prospective pilot study
No full textOBJECTIVE: There is an increasing interest in noninvasive tests for detecting Helicobacter pylori (H. pylori) infection. Unlike serological and urea breath tests, the possibility of searching for H. pylori in feces has been scarcely investigated. The aim of this prospective pilot study was to evaluate the usefulness of a new enzyme immunoassay for detecting H. pylori antigens in feces, as a predictor of H. pylori status in the pre- and posttreatment settings. METHODS: One hundred and fifty-four symptomatic, anti-H. pylori untreated patients (Group A) and 116 anti-H. pylori treated patients (Group B) underwent gastroscopy with biopsies of the antrum and corpus for histology (H) and rapid urease test (RUT). In the anti-H. pylori treated group, a 13C-urea breath test (UBT) was also performed. In Group A, H. pylori status was defined as positive or negative when both H and RUT gave concordant positive or negative results. In Group B, the patients were considered eradicated if all three tests were negative. A stool specimen was collected from all patients the day after gastroscopy, and tested by using an enzyme immunoassay commercial kit for detecting H. pylori antigens in feces (HpSAT). RESULTS: Eighty-five patients in Group A (55%) and 44 in Group B (38%) were H. pylori infected. On the whole, HpSAT showed a sensitivity of 94% and specificity of 86%. In Group A and Group B, sensitivity and specificity were 94% versus 93%, and 90% versus 82%, respectively (p < 0.05). CONCLUSIONS: HpSAT seems to be a reliable method for predicting H. pylori status in anti-H. pylori untreated patients. Conversely, the test appears less suitable to evaluate the outcome of the eradicating treatment. Consequently, it is likely to be accepted for the primary diagnosis of H. pylori status, particularly in dyspeptic young 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
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