1,721,529 research outputs found

    S. Uinzio, C. Di Santé, V. Fusco, G. Ravasi, R. Fabris, F. Rossi de Gasperis, Israele e le genti (RdT Books), 1991

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    Jacques Schlosser. S. Uinzio, C. Di Santé, V. Fusco, G. Ravasi, R. Fabris, F. Rossi de Gasperis, Israele e le genti (RdT Books), 1991. In: Revue des Sciences Religieuses, tome 70, fascicule 3, 1996. p. 407

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Informational analysis: a Shannon theoretic approach to measure the performance of a diagnostic test.

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    Diagnostic test accuracy, based on sensitivity, specificity, positive/negative predictive values (dichotomous case), and on ROC analysis (continuous case), should be expressed with a single, coherent index. We propose to modelize the diagnostic test as a flow of information between the disease, that is, a hidden state of the patient, and the physicians. We assume that (1) sensitivity, specificity, and false-positive/false-negative rates are the probabilities of a binary asymmetric channel; (2) the diagnostic channel information is measured by mutual information. We introduce two summary measures of accuracy, namely the information ratio (IR) for the dichotomous case, and the global information ratio (GIR) for the continuous case. We apply our model to a study by Pisano et al. (N Engl J Med 353(17):1773-1783, 2005), who compared digital versus film mammography, in diagnosing breast cancer in a screening population of 42,760 women. In film mammography, the maximum IR (0.178) corresponds to the standard cutoff of sensitivity and specificity provided by the ROC analysis (GIR 0.200). Maximum IR and GIR for digital mammography are higher (0.201 and 0.229, respectively), but IR corresponds to a cutoff with higher sensitivity but lower specificity, thus suggesting that larger information provided by digital mammography carries the risk of more false-positive cases

    Fifty years of Shannon information theory in assessing the accuracy and agreement of diagnostic tests

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    Since 1948, Shannon theoretic methods for modeling information have found a wide range of applications in several areas where information plays a key role, which goes well beyond the original scopes for which they have been conceived, namely data compression and error correction over a noisy channel. Among other uses, these methods have been applied in the broad field of medical diagnostics since the 1970s, to quantify diagnostic information, to evaluate diagnostic test performance, but also to be used as technical tools in image processing and registration. This review illustrates the main contributions in assessing the accuracy of diagnostic tests and the agreement between raters, focusing on diagnostic test performance measurements and paired agreement evaluation. This work also presents a recent unified, coherent, and hopefully, final information-theoretical approach to deal with the flows of information involved among the patient, the diagnostic test performed to appraise the state of disease, and the raters who are checking the test results. The approach is assessed by considering two case studies: the first one is related to evaluating extra-prostatic cancers; the second concerns the quality of rapid tests for COVID-19 detection

    Variations on the Author

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    “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

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    We 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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