1,721,017 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Ameliorating effects of exercise on disrupted epididymal sperm parameters in high fat diet-induced obese rats
Get PDFObjective: Obesity causes male infertility problems and affects the sperm quality. Recent studies have shown that exercise has positive effects on male fertility. The present study aimed to show the effects of swimming exercise on the epididymal sperm number, motility and morphology in hight fat diet (HFD)-induced obese rats. Materials and Methods: Four experimental groups (n=8 in each group) were formed. Standard (STD) and STD+Exercise (STD+EXC) groups were fed with standard rat diet (6% of calories as fat); HFD and HFD+Exercise (HFD+EXC) groups were fed with high fat diet (45% of calories as fat) for 18 weeks. The rats in STD+EXC and HFD+EXC groups were trained by swimming sessions (1 h per day for 5 days a week) during the last 6 weeks of the experiment. The left caudal epididymis was prepared to evaluate the number, motility and morphology of the spermatozoa. The right epididymal samples were processed for histological evaluation. Results: Normospermic parameters were seen in STD and STD+EXC groups. Sperm number and motility decreased and spermatozoa with abnormal morphology increased significantly in HFD group when compared with STD group. A large number of spermatozoa in the epididymal duct lumen and regular morphology of the fibromuscular connective tissue were observed in STD and STD+EXC groups. Most of the epididymal ducts consisted of decreased amount of spermatozoal accumulation in the HFD group. Degenerated pseudostratified columnar epithelium with vacuole formation were additional findings in this group. On the other hand, swimming exercise had an enhancement effect on sperm parameters with prominent spermatozoal accumulation in the ducts of epididymis in HFD induced obese rats. Conclusion: This study shows that HFD-induced obesity decreased the number and motility of spermatozoa, increased abnormal spermatozoa and caused disrupted epididymal morphology. We hypothesize that exercise enhanced HFD-induced spermatogenic and epididymal damages by the regulation of scrotal heat and possible inhibition of oxidative damage in the epididymis
Scanning electron microscopic study of cold-stored small bowel: comparison of Euro-Collins and Lactated Ringer's solutions
No full textThe increasing use of the small bowel for transplantation necessitates the development of optimum preservation techniques. The aim of our study was to investigate time-related morphological changes of the rat small bowel during preservation of the organ in hypothermic Euro-Collins and Lactated Ringer's solutions. It is the only study comparing these widely used preservation solutions with scanning electron microscopy, which is especially suitable to show the intestinal mucosa, one of the tissues of the intestine most susceptible to ischemia. Small bowels were perfused with either Euro-Collins, Lactated Ringer's or physiological saline solution and placed in respective preservation solutions at 4 degrees C for 0, 3, 6 and 12 hours. Biopsy samples were prepared for examination at the light and scanning electron microscopic levels. According to the results of this study we conclude that, even Lactated Ringer's solution showed better tissue preservation than Euro-Collins solution, both preservation solutions are suitable for short term preservation of the small bowel and that further ameliorations of the preservation solutions and/or techniques are required for long term preservation
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
The effect of alpha-melanocyte stimulating hormone on gentamicin-induced acute nephrotoxicity in rats
No full textThe effect of a-melanocyte stimulating hormone (alpha-MSH) was investigated on gentamicin-induced acute renal injury in rats. Sprague-Dawley rats (200-250 g; n = 8-10) were treated with gentamicin sulphate (GEN; 80 mg kg(-1)) or saline intraperitoneally for 7 consecutive days. alpha-MSH was administered at a dose of 25 mu g rat(-1) day(-1) following GEN or saline injections. On day 8, all animals were decapitated. Trunk blood and 24 h urine were collected to measure the serum creatinine levels, blood urea nitrogen (BUN) levels and to calculate the creatinine clearance values. The kidneys were excised for histological evaluation and for the measurement of malondialclehyde (MDA) levels, glutathione (GSH) contents and myeloperoxiclase (MPO) activity. Treatment with a-MSH reduced the severity of the renal lesions microscopically, decreased MDA content and MPO activity and restored GSH in kidney samples. However, it did not restore the impaired renal function tests due to GEN challenge. In conclusion, a-MSH treatment has a beneficial effect on GEN-induced acute nephrotoxicity, as confirmed by histological evaluation and biochemical assays; but it does not improve GEN-induced renal dysfunction. The mechanism of the protective effect could be attributed, at least in part, to decreased tissue leukocyte infiltration and thus, to decreased oxygen-derived reactive metabolite production. Copyright (c) 2007 John Wiley & Sons, Ltd
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Effect of FK506 in experimental glomerulonephritis: Light microscopic and ultrastructural study
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