1,720,955 research outputs found
Bicuspid aortic valve in competitive athletes.
No full textAIM:
Bicuspid aortic valve (BAV) is a common congenital cardiac condition. The presence of BAV in non-elite athletes has been poorly investigated; it is usually asymptomatic until valvular stenosis, regurgitation or other vascular alterations are evident.
DESIGN:
Over a three-year period, 2273 competitive athletes were consecutively investigated with transthoracic echocardiography. The traditional parameters, the aortic root dimensions at four levels and the systolic and diastolic flow of aortic valve, were studied with continuous Doppler according to the echo guidelines.
SETTING:
The study protocol included all the non-elite athletes investigated for the first evaluation to obtain eligibility.
PATIENTS:
2273 competitive athletes aged 8-60 years from several sports and regularly trained were evaluated with anamnesis, clinical check-up and echocardiography in order to exclude subjects with systemic or congenital heart disease.
RESULTS:
BAV was diagnosed in 58 athletes (2.5%). Of these, nine had normal valvular function, 47 had abnormal valvular function with mild-moderate aortic regurgitation, and two had moderate stenosis. Aortic root dimensions at all levels were significantly greater in athletes with BAV than in athletes with a normal tricuspid valve. No relation was found with age, body surface area, aortic regurgitation or years of training.
CONCLUSIONS:
BAV is a relatively common congenital cardiac disease in athletes and commonly asymptomatic for a long time. This study suggests the usefulness of evaluating young athletes using echocardiography at least once when they start their sporting activity
Effects of sports activity in athletes with bicuspid aortic valve and mild aortic regurgitation.
No full textOBJECTIVE:
In this study, the impact of regular training on left ventricle morphology in a group of athletes with bicuspid aortic valve (BAV) was evaluated.
DESIGN:
Longitudinal cohort study. A group of competitive athletes with BAV was followed up with a yearly standard echocardiographic examination for 5 years.
SETTING:
Sport Medicine Centre, University of Florence, Pre-Participation Protocol Study.
PARTICIPANTS:
A group of 88 consecutive athletes diagnosed with BAV was identified in the period January to December 1999, and 30 of these completed a 5-year follow-up. They were compared with a group of 56 athletes with a normal tricuspid valve (TAV).
RESULTS:
BAV athletes showed significant progressive increase in left ventricular dimensions and aortic diameters at four levels. The values were within the range of the general and non-athletic BAV populations. In TAV athletes, the aortic and left ventricle dimensions did not increase significantly and remained within physiological range.
CONCLUSIONS:
Left ventricular dimensions in competitive BAV athletes remain within the normal range. There is, however, a significant progressive increase in the BAV group compared with the TAV group. These results are in agreement with data obtained in previous studies on the non-athletic BAV population. Sports activity does not have an additional effect on cardiac morphology in athletes with asymptomatic BAV associated with mild regurgitation, for at least 5 years
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
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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