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    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

    Effect of timolol, latanoprost, and dorzolamide on circadian IOP in glaucoma or ocular hypertension

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    PURPOSE. To compare the around-the-clock intraocular pressure (IOP) reduction induced by timolol 0.5%, latanoprost 0.005%, and dorzolamide in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT). METHODS. In this crossover trial, 20 patients with POAG (n = 10) or OHT (n = 10) were treated with timolol, latanoprost, and dorzolamide for 1 month. The treatment sequence was randomized. All patients underwent measurements for four 24-hour tonometric curves: at baseline and after each 1-month period of treatment. The patients were admitted to the hospital, and IOP was measured by two well-trained evaluators masked to treatment assignment. Measurements were taken at 3, 6, and 9 AM and noon and at 3, 6, and 9 PM and midnight by handheld electronic tonometer (TonoPen XL; Bio-Rad, Glendale, CA) with the patient supine and sitting, and a Goldmann applanation tonometer (Haag-Streit, Bern, Switzerland) with the patient sitting at the slit lamp. Systemic blood pressure was recorded at the same times. The between-group differences were tested for significance by means of parametric analysis of variance. The circadian IOP curve of a small group of untreated healthy young subjects was also recorded using the same procedures. To compare the circadian IOP rhythms in the POAG-OHT and control groups, the acrophases for each subject were calculated. RESULTS. When Goldmann sitting values were considered, all the drugs significantly reduced IOP in comparison with baseline at all times, except for timolol at 3 AM. Latanoprost was more effective in lowering IOP than timolol at 3, 6, and 9 AM (P = 0.03), noon (P = 0.01), 9 PM, and midnight (P = 0.05) and was more effective than dorzolamide at 9 AM, noon (P = 0.03), and 3 and 6 PM (P = 0.04). Timolol was more effective than dorzolamide at 3 PM (P = 0.05), whereas dorzolamide performed better than timolol at midnight and 3 AM (P = 0.05). An ancillary finding of this study was that in the group of healthy subjects, the pattern of IOP curve was different that in patients with eye disease. CONCLUSIONS. Latanoprost seemed to lead to a fairly uniform circadian reduction in IOP, whereas timolol seemed to be less effective during the nighttime hours. Dorzolamide was less effective than latanoprost but led to a significant reduction in nocturnal IOP. The reason for the difference in the pattern of the IOP curve of healthy subjects is currently unknown and deserves further investigation

    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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