1,721,504 research outputs found
The timing of vision in basketball three-point shots
Full text linkThe aim of the present study was to explore the relationship between gaze behaviour, motor responses and the direction of visual attention when different levels of basketball players were engaged in a basketball three-point shot. Twelve near-experts and 12 amateur basketball players, wearing an eye tracker and an inertial sensor, performed 20 shots on a basketball field, receiving the ball from a teammate, who then acted as the opponent. The trial sequence was subdivided into catching, aiming and ball flight phases. The analysis demonstrated that near-experts exhibited longer fixation durations and saccades of lower amplitude and peak velocity than amateurs. The gaze behaviour showed that all players utilized fixations during the last part of the catching phase, during most of the aiming phase, and during the final part of the ball flight phase. The greatest number of saccades was exhibited between the aiming and the ball flight phases, when the ball was released by the players. Saccades were oriented toward the teammate during the catching phase. Instead, during the aiming and ball flight phases, saccade orientations were not polarized toward a specific visual cue. In conclusion, vision plays a critical role in every aspect of the three-point shot in basketball, from catching the ball, to aiming preparation, and shot execution. It is a key factor in decision-making, spatial awareness, and overall performance in team sports
Recovery time profiling after short-, middle-and long-distance swimming performance
No full textPiras, A, Cortesi, M, Campa, F, Perazzolo, M, and Gatta, G. Recovery time profiling after short-, middle- and long-distance swimming performance. J Strength Cond Res 33(5): 1408-1415, 2019-We investigated cardiac autonomic responses and hemodynamic parameters on recovery time after short-, middle- and long-swimming performance. Ten male regional-level swimmers were tested to estimate time and frequency domains of arterial baroreflex sensitivity (BRS) and heart rate variability after 100, 200, and 400 m of front crawl. We found a BRS reduction for 90 minutes after a maximal 100- and 200-m front crawl event, meanwhile the reflex was restored back to the baseline value approximately 70 minutes after 400 m. The vagally mediated high-frequency power of R-R intervals was significantly reduced for 30 minutes after 400 m, and more than 90 minutes after 100 and 200 m, with a concomitant increase of sympathetic modulation. After 400 m, athletes have reduced their stroke volume for 50 minutes, which remained at the baseline level after 100 and 200 m. Heart rate was restored back after 90 minutes in all conditions, whereas total peripheral vascular resistance was significantly reduced for 50 minutes after 200 and 400 m, with a persistent reduction after 100 m. Time course of autonomic recovery after 3 different swimming performances is influenced by exercise intensity and duration, showing a rapid recovery after 400 m, an intermediate recovery after 200 m, and a significantly delayed recovery after a more strictly anaerobic performance like 100 m of front crawl. These results could encourage coaches to consider that athlete might be affected by the specific recovery time of the previous exercise performed, suggesting that the management of the exercise intensity, and appropriate monitoring of cardiac autonomic parameters might be helpful to know the physical condition of each athlete
I costumi a “compressione graduata” per aiutare il recupero nel nuoto
No full textDurante le manifestazioni di nuoto, le gare si susseguono a ritmo incessante e gli atleti che puntano ad eccellere sono motivati a competere su diverse distanze. Ai Mondiali di Doha nel 2014, l’ungherese Katinka Hosszu ha partecipato a 20 gare in 5 giorni, due volte sui 400 metri ed una su gli 800 metri, vincendo 4 ori e segnando 4 record del mondo. Nel 2015, agli Europei a Netanya, si è ripetuta gareggiando in venti gare (sempre in 5 giorni) e vincendo 6 ori ed 1 argento.
La tendenza a partecipare a più gare ha riportato l’attenzione verso il problema del recupero. Dopo sforzi elevati, alti livelli di stress comportano accumulo di metaboliti (Kirwan 1988, Costill 1991) che influenzando negativamente le gare successive (Felix 1997), determinando importanti cali della prestazione negli ultimi giorni della competizione, quando invece si dovrebbe essere al meglio per poter competere durante le finali
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
Understanding the underlying mechanisms of Quiet Eye: the role of microsaccades and pupil-size during fixation.
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