1,721,043 research outputs found
Neuromuscular Factors Related to Hamstring Muscle Function, Performance and Injury
No full textHamstring function is influenced by a number of neural, architectural and morphological factors, and the adaptability of these characteristics has important implications for optimizing performance and reducing injury risk. High rates of maximal or near-maximal hamstring force development are required to generate peak horizontal velocities during running, and this is largely determined by the extent to which these muscles can be voluntarily activated. Greater eccentric hamstring strength also correlates with better acceleration capacity and likely improves the ability to decelerate the lower limb during the presumably injurious terminal swing phase of high-speed running. The intra- and intermuscular coordination of the hamstrings appears to influence both hamstring muscle fatiguability and the risk of muscle strain injury. Muscle volume and architectural features such as fascicle length and pennation angle also influence hamstring function, and these vary considerably between hamstring muscles, between individuals and with training status. The adaptability of these features has been explored to a significant extent in recent times, and careful exercise selection allows selective targeting of individual hamstring muscles or muscle segments and this appears to influence the pattern of chronic adaptations such as muscle hypertrophy. Short fascicles within the often-injured long head of biceps femoris may predispose athletes to strain injury but these appear to respond in a contraction-mode-specific manner; lengthening after eccentric training and shortening after concentric training of 4 or more weeks. Conventional training with eccentric and concentric phases in each repetition can also lengthen fascicles, possibly in an excursion (muscle length)-dependent manner. A large biceps femoris muscle to proximal aponeurosis width ratio has been proposed as a potential risk factor for hamstring strain injury, although this is only supported by biomechanical modelling at the time of writing. High levels of anterior pelvic tilt and lateral trunk flexion during sprint running may also predispose athletes to hamstring strain injury, although the quantity of evidence for this is small at the moment. At present, the optimal methods for altering coordination and running technique are not known
Aging and the force-velocity relationship of muscles
No full textAging in humans is associated with a loss in neuromuscular function and performance. This is related, in part, to the reduction in muscular strength and power caused by a loss of skeletal muscle mass (sarcopenia) and changes in muscle architecture. Due to these changes, the force-velocity (f-v) relationship of human muscles alters with age. This change has functional implications such as slower walking speeds. Different methods to reverse these changes have been investigated, including traditional resistance training, power training and eccentric (or eccentrically-biased) resistance training. This review will summarise the changes of the f-v relationship with age, the functional implications of these changes and the various methods to reverse or at least partly ameliorate these changes
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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