1,720,960 research outputs found
Size at birth and carotid atherosclerosis in later life
No full textSeveral studies have shown that low birthweight is associated with a higher risk of stroke and coronary heart disease in later life. Increased atherogenesis may be one underlying mechanism, but few studies have examined this directly. We used duplex ultrasonography to assess the extra-cranial carotid arteries of 389 elderly men and women born and still living in Sheffield, UK, whose recorded birth measurements were available. Men and women who had weighed 6.5 lbs or less at birth had a higher risk of having carotid stenosis >30% than those who weighed over 7.5 lbs, but this trend was not statistically significant (OR 1.8, 95% CI 1.0–3.3). Women who had been lighter or who had a smaller head circumference at birth tended to have an increased intima-media thickness, but these relations ceased to be statistically significant after adjustment for gestational age and cardiovascular risk factors. In men, by contrast, an increased intima-media thickness was associated with having been heavier at birth (P=0.049) or having had a larger abdominal circumference at birth (P=0.040), after adjustment for gestational age and cardiovascular risk factors. These results provide little evidence that impaired fetal growth increases susceptibility to atherogenesis
Antioxidant vitamin status and carotid atherosclerosis in the elderly
No full textBackground: The oxidative modification of LDL is thought to play a crucial role in the initiation of atherosclerosis. Antioxidant vitamins can protect LDL from oxidation, and high intakes or blood concentrations of these vitamins have been linked with a reduced risk of cardiovascular disease. Few data are available on the importance of antioxidant vitamins in earlier stages of atherogenesis.Objective: We investigated the cross-sectional relation between antioxidant vitamin status and carotid atherosclerosis in a group of elderly persons.Design: The study sample comprised 468 men and women aged 66–75 y living in Sheffield, United Kingdom. Duplex ultrasonography was used to measure intima-media thickness and the degree of stenosis in the extracranial carotid arteries. Antioxidant vitamin status was assessed by measuring fasting plasma concentrations of vitamin C, vitamin E, and ß-carotene.Results: In the men, after adjustment for age and cardiovascular disease risk factors, a 20% higher plasma vitamin C concentration was associated with a 0.004-mm smaller intima-media thickness; a 20% higher ß-carotene concentration was associated with a 0.005-mm smaller intima-media thickness. Compared with men with high blood concentrations of ß-carotene or cholesterol-adjusted vitamin E, those with low blood concentrations of these vitamins were 2.5 times as likely to have carotid stenosis of >30%. We found no significant trends between plasma concentrations of antioxidant vitamins and either measure of carotid atherosclerosis in the women.Conclusion: A high antioxidant vitamin status may help to prevent the initiation and progression of early atherosclerotic lesions in men
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
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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