1,721,231 research outputs found

    Psycho-physiological aspects of small combats in taekwondo: impact of area size and within-round sparring partners

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    The study investigated physiological and psychological responses to taekwondo combat sessions as a function of different area sizes and within-round sparring partners. Twenty-four adolescent (age: 17 +/- 1years) male (n = 12) and female (n = 12) taekwondo athletes participated in the study. Each athlete confronted 1 (1 vs.1; no sparring partner change) or 2 (1vs.2; within-round sparring partner change every minute) opponents in different area sizes (i.e., 4 x 4 m, 6 x 6 m, and 8 x 8 m) for 2 min. Blood lactate concentration ([La]) was measured before and after bouts. Heart rate (HR) was measured throughout the contests and rating of perceived exertion was assessed after bouts. Mean HR (HRmean) and percentage of maximum HR (%HRmax) determined during a 20-m multistage shuttle run test were used for analysis. Mood states were assessed before and after bouts and physical enjoyment was analyzed after bouts. The results showed higher HRmean and %HRmax values for the 1 vs.1 compared to the 1vs.2 condition (p < 0.001) and [La] values were higher at post-combat measurements (p < 0.001). Moreover, tension and fatigue were higher in 6 x 6 m compared with 8 x 8 m (p = 0.022 and p = 0.023, respectively) and anger was higher in 6 x 6 m and 8 x 8 m in comparison with 4 x 4 m (p = 0.012 and p = 0.043, respectively). Confusion increased from before to after bouts (p < 0.001), from 4 x 4 m and 6 x 6 m area sizes to 8 x 8 m (p = 0.001 and p = 0.018, respectively), and from 1vs.1 to 1vs.2 (p < 0.001). Furthermore, vigour decreased from before to after bouts (p < 0.01). Taekwondo combat sessions are a specific conditioning exercise for athletes. Thus, coaches can use the 1vs.1 condition to elicit higher HR responses and 6 x 6 m area size to induce higher psychological stress, mimicking what occurs during a competition

    Effects of adding small combat games to regular Taekwondo training on physiological and performance outcomes in male young athletes

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    This study investigated the effect of area sizes (4 * 4, 6 * 6, and 8 * 8 m) and effort-pause ratios (free combat vs. 1:2) variation on the physiological and perceptive responses during taekwondo combats (Study 1). In a second study, the effects on physical performance of 8 weeks of small combat-based training added to regular taekwondo training were investigated (Study 2). In random order, 32 male taekwondo athletes performed six (i.e., two effort-to-pause ratios * three area sizes conditions) different 2-min taekwondo combats (Study 1). Thereafter (Study 2), they were randomly assigned to three experimental groups (4 * 4, 6 * 6, and 8 * 8 m) and an active control group (CG). Regarding Study 1, blood lactate concentration [La] before and after each combat, mean heart rate (HRmean) during each combat, and rating of perceived exertion (CR-10) immediately after each combat were assessed. Regarding Study 2, progressive specific taekwondo (PSTT) to estimate maximum oxygen consumption (VO2max), taekwondo-specific agility, and countermovement jump (CMJ) tests were administered before and after 8 weeks of training. Study 1 results showed that 4 * 4 m elicited lower HRmean values compared with 6 * 6 m (d = -0.42 [small], p = 0.030) and free combat induced higher values compared with the 1:2 ratio (d = 1.71 [large], p < 0.001). For [La]post, 4 * 4 m area size induced higher values than 6 * 6 m (d = 0.99 [moderate], p < 0.001) and 8 * 8 m (d = 0.89 [moderate], p < 0.001) and free combat induced higher values than 1:2 ratio (d = 0.69 [moderate], p < 0.001). Higher CR-10 scores were registered after free combat compared with 1:2 ratio (d = 0.44 [small], p = 0.007). For Study 2, VO2max increased after training [F (1, 56) =30.532, p < 0.001; post-hoc: d = 1.27 [large], p < 0.001] with higher values for 4 * 4 m compared with CG (d = 1.15 [moderate], p = 0.009). Agility performance improved after training [F (1, 56) = 4.419, p = 0.04; post-hoc: d = -0.46 [small], p = 0.04] and 4 * 4 m induced lower values in comparison with 6 * 6 m (d = -1.56 [large], p = 0.001) and CG (d = -0.77 [moderate], p = 0.049). No training type influenced CMJ performance. Smaller area size elicited contrasting results in terms of metabolic demand compared with larger sizes (i.e., lower HRmean but higher [La] and CR-10), whereas free combat induced variables' consistently higher values compared with imposed 1:2 ratio (Study 1). Taekwondo training is effective to improve VO2max and agility (Study 2), but small combat training modality should be investigated further

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    INJURIES DURING SUWARI SEOI NAGE IN ITALIAN JUDO ATHLETES

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    The safety of the athletes has to be a priority for every sport organization and coaches. Judo is a grappling combat sport, where the injuries occur during competition and training. Despite the wide range of attacks possibilities in Judo, very few are the most used techniques in competition. One of the most successful and frequently used technique is the Suwari Seoi Nage, the throw type where the attacker fall on both knees during the action. However, we didn’t find any investigation about the impact of the use of Suwari Seoi Nage on acute injury in Judo athletes. Thus, this pilot study was conducted with a sample of Italian judokas. The aim was to identify the risk factor injury events that can occur to who performs this technique, in order to suggest possible preventive strategies in future. The survey assessed to 94 adult athletes, females and males, brown and black belts, with different judo abilities and training experiences, find out that the injuries during the execution of this technique happened to one judo player every four, mainly to the knees, mostly because of a wrong execution and secondly because of a bad defense from the opponent

    Variations on the Author

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    “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

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    We 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

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    We 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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