1,721,083 research outputs found
Coronary atherosclerosis in athletes: recent insights and clinical considerations
No full textEvidence from international cohort studies has shown increased coronary atheroscle-rosis in male athletes vs controls, 1 whereas data for female athletes are scarce and contradictory but likely not different from controls. 1 A larger lifelong exercise volume and greater proportion of very vigorous intensity exercise training were identified as independent predictors of the prevalence and progression of coronary artery calcification scores (CACS) in males. 2-4 Early studies hypothesised that accelerated calcification may represent plaque stabilisation as less harmful plaque phenotypes (ie, more calcified and less mixed plaques) were found in athletes vs controls. 3 4 However, this concept was challenged by the Master@Heart study as lifelong male endurance athletes had a similar plaque morphology compared with non-athletes. 5 These collective findings raise questions whether athletes should be worried about the development of coronary atherosclerosis and its clinical sequelae. THE GOOD NEWS Athletes have a better life expectancy compared with the general population with risk reductions for all-cause and cardiovascular mortality of ~30%-40%. Moreover, individuals with a higher cardiorespiratory fitness have a lower cardiovascular event rate for any given CACS compared with individuals with lower fitness. 6 This may be partially attributable to a less harmful plaque composition. For example, in a UK cohort of 106 male master athletes (55±9 years old) without cardiovascular risk factors compared with 54 non-athletic controls, athletes had more calcified and less mixed plaque morphology, 3 which are known to be less rupture prone. 7 These findings were reinforced by the Dutch Measuring Athletes' Risk of Cardiovascular Events (MARC) study, consisting of 318 recreational male athletes (aged ≥45 years), as fewer mixed and more often only calci-fied plaques were found among the most active vs least active athletes. 4 Although the Belgian Master@Heart study showed no difference in plaque composition between 191 lifelong athletes (56 (51-61) years old) and 176 non-athletic controls, this may relate to the inclusion criteria. Controls were allowed to perform up to 3 hours of exercise per week and those with cardiovascular risk factors were excluded. The Master@Heart control group, therefore, constitutes a group of extremely healthy individuals, evidenced by their very low age-specific CAC percen-tile scores (0 (0-62)%), benign plaque composition (67% calcified plaque) and high fitness level (122 (108-138)% of predicted VO 2peak). In fact, plaque characteristics of the Master@Heart controls were comparable with the master athletes of the UK cohort 3 and the most active group of the MARC study, 4 suggesting that all participants of the Master@Heart study had predominantly favourable plaque morphology
High-load resistance training in cardiac rehabilitation: is it time to debunk old clinical dogmas for a better clinical tomorrow?
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Advancing Aerobic Exercise Training Intensity Prescription in Health and Disease Beyond Standard Recommendations: A Call to Action
No full textGuidelines for aerobic exercise training (AET) often recommend training intensities on the basis of a percentage of peak effort (e.g. %peak heart rate [%HRpeak ], %peak oxygen uptake [%VO2peak ]). However, such an approach could be associated with a higher inter-individual variability in acutely induced physiological responses (e.g. blood lactate, HR, VO2) when compared with threshold-based prescription (i.e. ventilatory threshold [VT] or lactate threshold [LT]). Therefore, we performed a literature review to compare the acute physiological impact of AET prescription based on fraction of the peak effort versus threshold-based exercise prescription (VTs and LTs), and how these prescription options may influence the efficacy of exercise intervention in healthy subjects and patients with cardiovascular risk or disease. Data from cross-sectional studies (15 studies; 5312 participants) indeed reveal a greater inter-individual variance in acute physiological responses to a single exercise (e.g. HR, VO2 , blood lactate) when exercising at the same %HR peak or % VO2peak compared with exercising at (a fraction of) VT or LT. Data from randomised exercise intervention studies (3 studies; 135 participants) and a meta-analysis (1544 individuals from 42 studies) show that aerobic exercise prescription based on the percentage of peak effort leads to smaller improvements in VO2peak and metabolic health when compared with aerobic exercise prescription based on the VTs or LT. These collective findings suggest that threshold-based AET intensity prescription elicit more homogeneous acute physiological responses, and greater VO2peak improvements. Hence, it is time to move past standard recommendations and implement a threshold-based approach when prescribing the AET intensity.No funding or research grants were used in the preparation of this manuscript
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
Coronary atherosclerosis in athletes: emerging concepts and preventive strategies
No full textThere should be no assumption that an athlete is immune to coronary artery disease (CAD), even when traditional cardiovascular (CV) risk factors appear well-managed. Excelling in certain aspects of health does not equate to total CV protection. Recent data from cardiac imaging studies have raised the possibility that long-term, high-volume, high-intensity endurance exercise is associated with coronary atherosclerosis. Whilst the risk of CV events has not been shown to rise with athletic activity, the potential for CAD should not be overlooked as it is the leading cause of sudden cardiac death in athletes >35 years of age (i.e. 'Masters athletes'). Evaluating both traditional and non-traditional risk factors for CAD is the most important part of pre-participation evaluation in Masters athletes. When managing athletes at risk of CAD it is important to adopt a shared decision-making approach regarding lifestyle adaptation and lipid-lowering treatments. In the great majority of athletes, after excluding the presence of symptoms and inducible ischaemia, this advice should include encouragement to continue exercising as available data indicate that higher levels of fitness are associated with a markedly attenuated incidence of coronary events regardless of the severity of coronary disease. Future research is needed to establish the relationship between clinically relevant CAD outcomes and coronary artery calcification in Masters Athletes, the role of sex, as well as exploration of the mechanisms underpinning these unexpected CV adaptations.The authors would like to thank Dr Laura DeFina for providing add itional data on the characterization of coronary artery calcification scores in the Cooper Clinic Longitudinal Stud
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
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