1,721,228 research outputs found
MORPHOMETRY AND GH/IGF-1 AXIS DEFICIENCY MAY IDENTIFY A FORM OF DILATED CARDIOMYOPATHY WHICH IS CORRECTED BY RECOMBINANT HUMAN GROWTH-HORMONE (RHGH)
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Vitamin D deficiency and sarcopenia in older persons
No full textVitamin D deficiency is a common health problem worldwide, in particular among older people. Vitamin D regulates and modulates the physiology and function of multiple human systems, including the skeletal muscle. The effect of vitamin D on the muscle has been widely investigated, suggesting that this hormone can stimulate the proliferation and differentiation of skeletal muscle fibers, maintaining and improving muscle strength and physical performance. Older persons have a higher prevalence of low Vitamin D levels as a consequence of low dietary intake and reduced ultraviolet irradiation of the skin. Therefore, older people with vitamin D deficiency might be at risk of sarcopenia, a geriatric syndrome characterized by the progressive loss of skeletal muscle mass and strength often complicated by adverse events, such as falls, disability hospitalization and death. Several randomized clinical trials have been conducted to investigate the effect of oral vitamin D supplementation in older patients to prevent or treat sarcopenia, but results are still controversial. In this narrative review we summarize the biological, clinical and epidemiological evidence supporting the hypothesis of a causal association between Vitamin D deficiency and an increased risk of sarcopenia in older people
Particle Beam Therapy (Hadrontherapy): Basis for interest and Clinical Experience
No full textThe particle or hadron beams deployed in radiotherapy (protons, neutrons and helium, carbon, oxygen and neon ions) have physical and radiobiological characteristics which differ from those of conventional radiotherapy beams (photons) and which offer a number of theoretical advantages over conventional radiotherapy. After briefly describing the properties of hadron beams in comparison to photons, this review discusses the indications for hadrontherapy and analyses accumulated experience on the use of this modality to treat mainly neoplastic lesions, as published by the relatively few hadrontherapy centres operating around the world. The analysis indicates that for selected patients and tumours (particularly uveal melanomas and base of skull/spinal chordomas and chondrosarcomas), hadrontherapy produces greater disease-ti ee survival. The advantages of hadrontherapy are most promisingly realised when used in conjunction with modern patient positioning, radiation delivery and focusing techniques (e.g. on-line imaging, three-dimensional conformal radiotherapy) developed to improve the efficacy of photon therapy. Although the construction and running costs of hadrontherapy units are considerably greater than those of conventional facilities, a comprehensive analysis that considers all the costs, particularly those resulting from the failure of less effective conventional radiotherapy, might indicate that hadrontherapy could be cost effective. En conclusion, the growing interest in this form of treatment seems to be fully justified by the results obtained to date, although more efficacy and dosing studies are required. (C) 1998 Elsevier Science Ltd. All rights reserved
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