1,721,171 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

    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

    Skeletal involvement in adult patients with endogenous hypercortisolism

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    Overt endogenous glucocorticoid excess is a well-recognized cause of bone loss and osteoporotic fractures. Cortisol excess inhibits bone formation, increases bone resorption, impairs calcium absorption from the gut, and affects the secretion of several hormones (in particular gonadotropins and GH), cytokines, and growth factors, influencing bone metabolism. The glucocorticoid excess mainly affects trabecular bone, leading to vertebral fractures in up to 70% of patients. Osteoporotic fractures may be the presenting symptom of an otherwise silent glucocorticoid excess and can precede the diagnosis of hypercortisolism by up to 2 yr. The removal of glucocorticoid excess leads to a recovery of bone mass which is, however, often incomplete and delayed, although it reduces the risk of osteoporotic fractures. Bisphosphonate therapy has been suggested to be useful in maintaining bone mass in these patients. Subclinical hypercortisolism, a condition of impaired hypothalamic-adrenal-axis homeostasis without the classical signs and symptoms of glucocorticoid excess, is a recently defined entity, which has been shown to be associated to increased bone resorption, bone loss, and high prevalence of vertebral fractures regardless of gonadal status. However, data about the effect of this subtle glucocorticoid excess on bone are still scarce and conflicting. Moreover, it is not yet known whether removing the cause of subclinical hypercortisolism leads to a recovery of bone mass and reduces the risk of osteoporotic fractures. Finally, recent data suggest that subclinical hypercortisolism is a common and underrated finding in patients with established osteoporosis. In summary, it is crucial to evaluate the risk of osteoporosis and fractures in patients with glucocorticoid excess; on the other hand, it also seems advisable to screen for glucocorticoid excess patients with osteoporotic fractures without known secondary causes of osteoporosis

    Follow-up of patients with adrenal incidentaloma, in accordance with the European society of endocrinology guidelines : could we be safe?

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    Recently, the European Society of Endocrinology (ESE) published new guidelines on the management of adrenal incidentalomas. At the same time Lopez and coworkers published on the Annals of Internal Medicine an important study showing that even patients with non-functioning adrenal tumors have an increased risk of incident diabetes. In consideration of previous data and of the results of the study of Lopez and coworkers, some points emerge from the ESE Guidelines that deserve attention. Firstly, it must be observed that the term "autonomous cortisol secretion," introduced by the ESE Panel in the place of the commonly used "subclinical hypercortisolism," seems questionable, since the guidelines do not suggest determining the adrenocorticotroph hormone levels that could give the certain proof of a truly autonomous cortisol secretion. Secondly, the ESE Guidelines suggest against repeated hormonal workup in AI patients with a normal hormonal secretion at initial evaluation, but also in those with a "possible autonomous cortisol secretion," if in the absence of comorbidities potentially related to hypercortisolism. Thirdly, the ESE Guidelines suggest against further imaging during follow-up in patients with an adrenal mass below 4 cm in size with clear benign features on imaging studies. Considering the available literature data that are briefly summarized in this comment, we believe that no sufficient evidence is available to date for giving sharp-cutting recommendations about the uselessness of a biochemical and morphological follow-up in AI patients, even in those with initially benign and not hypersecreting adrenal adenomas. However, if a recommendation has to be given on the basis of the present evidences, we should suggest to biochemically and morphologically follow-up AI patients for at least 5 years

    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

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods
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