1,721,243 research outputs found

    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

    Testosterone levels in obese male patients with obstructive sleep apnea syndrome: relation to oxygen desaturation, body weight, fat distribution and the metabolic parameters

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    To investigate the impact of obstructive sleep apnea syndrome (OSAS) on testosterone levels and on the main parameters of the metabolic syndrome in abdominally obese men, 15 male subjects with abdominal obesity phenotype and polysomnographic diagnosis of OSAS (OB-OSAS) and 15 controls matched for age and anthropometric parameters (OB) were investigated. Anthropometry, SHBG, sex hormones and several parameters of the metabolic syndrome were measured. Only subjects with an Epworth Sleepiness Score greater than 10 underwent a polysomnographic study with calculation of the number of desaturation rates per sleeping hour (ODI), the minimal oxygen saturation during each desaturation episode (minSaO(2)) and the mean minimal arterial oxygen saturation for the whole night period (MminSaO(2)). Both total and free testosterone levels were lower in OB-OSAS than in OB patients. A negative correlation between polysomnographic parameters (ODI, minSaO(2) and MminSaO(2)) and testosterone levels was found. The relationship between total and free testosterone and ODI persisted after adjusting for body mass index (BMI) and waist (W) values. Triglyceride and uric acid levels were significantly higher in OB-OSAS than in OB patients. A negative correlation between testosterone and acid uric level and a positive correlation between testosterone and HDL-cholesterol level was found, regardless of BMI and W circumference, particularly in the OB-OSAS group. Our study suggests that, in patients with obesity and OSAS, the severity of hypoxia during sleeping hours may be an additional factor in reducing testosterone levels, regardless of BMI and abdominal fatness. This may contribute in worsening metabolic abnormalities which, in men with OSAS, exceed those expected on the basis of degree of obesity and pattern of fat distribution

    New perspectives on the definition and management of polycystic ovary syndrome

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    Background: There is a growing debate on the opportunity of improving the understanding in the diagnosis and management of polycystic ovary syndrome (PCOS). Objective: This review article summarizes recent research related to the definition of polycystic ovary syndrome (PCOS). Methods: Review of the recent literature on the topic. Results: New ideas on the definition of hyperandrogenism, based on new scientific data and clinical perspectives are presented. (i) In fact, recent studies have pointed out the need to improve the concept of androgen excess by using a larger androgen profile, rather than simply measuring the testosterone blood levels. (ii) Due to the poor correlation between androgen blood levels and the degree of hirsutism, it is proposed that the definition of hyperandrogenism should be based on the presence of blood androgen excess and hirsutism, considered separately, because their pathophysiological mechanisms may differ according to the different phenotypes of PCOS. (iii) The potential role of obesity in favoring the development of PCOS during adolescence is also discussed and the concept of “PCOS secondary to obesity” is developed. (iv) Finally, the need for greater appropriateness in the evaluation of possible coexistence is highlighted, in patients with PCOS who have fasting or glucose-stimulated very high insulin levels, or severe insulin-resistant states. Conclusions: Based on what was discussed in this review, we believe that there are margins for modifying some of the current criteria that define the various PCOS phenotypes

    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
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