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    Endoscopic surgery for juvenile angiofibroma: a critical review of indications after 46 cases.

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    BACKGROUND: At present, transnasal endoscopic surgery is considered a viable option in the management of small-intermediate size juvenile angiofibromas (JAs). The authors critically review their 14-year experience in the management of this lesion to refine selection criteria for an endoscopic approach. METHODS: From January 1994 to May 2008, 46 patients were treated by a pure endoscopic resection after vascular embolization (87%). The lesions were classified according to Andrews (Andrews JC, et al., The surgical management of extensive nasopharyngeal angiofibromas with the infratemporal fossa approach, Laryngoscope 99:429-437, 1989) and Onerci (Onerci M, et al. Juvenile nasopharyngeal angiofibroma: A revised staging system, Rhinology 44:39-45, 2006) staging systems. All patients were followed by regular endoscopic and magnetic resonance imaging (MRI) examinations. RESULTS: Lesions were classified as follows: stage I, n = 5; stage II, n = 24; stage IIIa, n = 14; stage IIIb, n = 3 according to Andrews classification system; stage 1, n = 9; stage II, n = 12; stage III, n = 26 according to Onerci's system. Unilateral blood supply was detected in 39 (85%) cases. Feeding vessels from the internal carotid artery (ICA) were also reported in 14 (30%) patients. Intraoperative blood loss ranged from 250 to 1300 mL (mean, 580 mL). In four (8.7%) cases, suspicious residual disease was detected by MRI. In one patient, a 1-cm persistent lesion was endoscopically removed because septoplasty was required and a slight increase in size was noticed. The other three lesions, all located in the root of the pterygoid plate, are nearly stable in size and are currently under MRI follow-up. CONCLUSION: The improvement of surgical instrumentation and the experience acquired during a 14-year period have contributed to expanding the indications for endoscopic surgery in the management of JAs. Even stage III lesions may be successfully managed, unless the ICA is encased or if it provides an extensive blood supply. An external approach may be required when critical structures such as the ICA, cavernous sinus, or optic nerve are involved by lesions that are persistent after previous treatment; such a situation may prevent safe and radical dissection with a pure endoscopic approach. Better understanding of the factors influencing the growth of residual lesions is needed to differentiate those requiring re-treatment from those which can be simply observed

    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

    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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