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Irineu Loturco Lucas A. Pereira Valter P. Reis Chris Bishop Vinicius Zanetti Pedro E. Alcaraz 《Journal of sports sciences》2020,38(11-12):1416-1422
ABSTRACT This study aimed to examine the effects of two jump squat (JS) training programs involving different loading ranges in under-20 soccer players during a preseason period. Twenty-three elite young soccer players performed sprint speed (at 5-, 10-, and 20-m), change-of-direction (COD) speed, JS peak-power (PP), and countermovement jump (CMJ) tests pre and post four weeks of training. Athletes were pair-matched in two groups according to their optimum power loads (OPL) as follows: lower than OPL (LOPL; athletes who trained at a load 20% lower than the OPL) and higher than OPL (HOPL; athletes who trained at a load 20% higher than the OPL). Magnitude-based inferences were used to compare pre- and post-training measures. Meaningful increases in the PP JS were observed for both groups. Likely and possible improvements were observed in the 5- and 10-m sprint velocity in the LOPL group. Meanwhile, possible and likely improvements were observed in the CMJ, 5- and 10-m sprint velocity, and COD speed in the HOPL group. Overall, both training schemes induced positive changes in athletic performance. Soccer coaches and sport scientists can implement the JS OPL-based training schemes presented here, either separately or combined, to improve the physical performance of youth soccer players. 相似文献
23.
Ethics and Information Technology - Under what circumstances if ever ought we to grant that Artificial Intelligences (AI) are persons? The question of whether AI could have the high degree of moral... 相似文献
24.
Terese L. Chmielewski Justin Tatman Shuhei Suzuki MaryBeth Horodyski Darcy S. Reisman Russell M. Bauer James R. Clugston Daniel C. Herman 《运动与健康科学(英文)》2021,10(2):154
This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion (SRC) to increased risk for musculoskeletal injury. Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts. A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk. Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task. Motor control is inclusive of motor planning and motor learning. If sensory information is not accurately perceived or there is interference with sensory information processing and cognition, motor function will be altered, and an athlete may become vulnerable to injury during sport participation. Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria, including a normal neurological examination, resolution of symptoms, and return to baseline function on traditional concussion testing. In conjunction, altered motor function is demonstrated after SRC in muscle activation and force production, movement patterns, balance/postural stability, and motor task performance, especially performance of a motor task paired with a cognitive task (i.e., dual-task condition). The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum. 相似文献
25.
Rebeca Fernandes Ferreira Lima Marcela Raffaelli Normanda Araujo de Morais Juliana P. Santana Carlos J. Nieto Silvia H. Koller 《Child development》2020,91(4):1237-1253
Trajectories of adjustment were examined in a sample of street-involved youth across a 1-year period. Participants (N = 113; Mage = 14.18 years; 80.5% male, 91% non-White) were recruited in three Brazilian cities. Interviews conducted at three time points included six measures of physical and psychological adjustment. Unconditional growth models revealed linear declines over time (i.e., improved adjustment) on three indicators: health symptoms, sexual risk behaviors, and negative affect. There were no linear changes in drug use, positive affect, or life satisfaction. Conditional growth models revealed few significant effects for age or gender, but ratings of stressful life events moderated longitudinal changes in health symptoms, drug use, and negative affect. Implications for practice, policy, and theory are discussed. 相似文献
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Mizuki H. Wyant Elizabeth H. Hurst Justin Reedy 《Journal of Intercultural Communication Research》2020,49(4):372-393
ABSTRACT This study examined international students’ interests in public issues in the U.S. and motivational factors behind their discourse or avoidance of such issues. In-depth interviews with international students revealed that they discuss certain public issues in the U.S. to gain or exchange information and knowledge, because these issues are relevant to themselves and others, or due to the misconceptions that others have about their country. Moreover, international students tend to avoid certain public issues because of the level of their knowledge and lack of interest in such issues and in order to avoid dissonance caused by the public issues. 相似文献
28.
Simon J. Roberts James R. Rudd Matthew J. Reeves 《Journal of sports sciences》2020,38(11-12):1454-1464
ABSTRACT The present study examined the efficacy of a coaching curriculum, based on non-linear pedagogy, on improving attacking players’ individual learning objectives (ILOs) in elite-youth football. Participants included 22 attacking players (i.e., centre-forwards, wide-players and attacking midfield players) from a professional football academy in England. The players were randomly appointed to both control (CON) and intervention (INT) periods following baseline measures. The INT (non-linear) and CON (linear) periods were both designed to support the ILOs provided to each player as part of the elite player performance plan. The study adopted a randomised cross-over design and ILOs considered important for attacking players (i.e., strong foot finishing, weak foot finishing, 1-v-1 and decision-making) were evaluated using the Loughborough Shooting Skill Test. The results showed significant differences for INT in 1-v-1 (P< 0.02) and decision-making (P< 0.01). However, there were no significant differences for strong foot finishing, weak foot finishing or time taken. These results support non-linear pedagogy in developing 1-v-1 game play and decision-making but not for technical shooting proficiency. 相似文献
29.
Sheina Lew-Levy Adam H. Boyette Alyssa N. Crittenden Barry S. Hewlett Michael E. Lamb 《Child development》2020,91(4):1284-1301
Few data exist on gender-typed and gender-segregated play in hunter-gatherer societies, despite their unique demographic and cultural features which may influence children’s gendered play. Using naturalistic observations of Hadza (N = 46, 41% female) and BaYaka (N = 65, 48% female) hunter-gatherer 3- to 18-year-olds from Tanzania and the Republic of Congo, we showed that access to playmates was negatively associated with playing in mixed-gender groups. Young boys did not engage in more rough-and-tumble play than girls, but adolescent boys participated in this type of play more than adolescent girls. Children were also more likely to participate in work-themed play which conformed to gender norms within their society. Findings are discussed within the context of gendered division of labor, child autonomy, and demography. 相似文献
30.
Luis Felipe Luna-Reyes David F. Andersen Laura J. Black Theresa A. Pardo 《Government Information Quarterly》2021,38(2):101570
This research identifies main feedback dynamics associated with social processes necessary to make sense of ambiguous project goals, typical of large digital government projects. The study reports on findings from a case analysis using participatory approaches in system dynamics, based on a digital government project integrating information systems of New York's criminal justice agencies. Findings stress the importance of visuals in the sensemaking process that results from the interaction of technical and social outcomes produced through identifying and continuously re-interpreting main project issues and goals. Project analyses suggest that requisite elements of successfully managing this type of project include 1) facilitation that enables diversity of ideas, 2) shared visuals and re-presentations of participants' efforts to work on the issues, and 3) iterative social construction of objectives, progress, and valid processes for doing the work; each of these plays a role in three different feedback processes sustaining (or undermining) the group engagement needed to yield successful integrative work. The study contributes to the literature in digital government by introducing the lenses of people-centered project management processes, an emerging approach in project management, to underscore the role of social processes in technical projects. 相似文献