The effect of smartphones and playing video games on decision-making in soccer players: A crossover and randomised study     

Leonardo S. Fortes  Dalton De Lima-Junior  Lenamar Fiorese  José R. A. Nascimento-Júnior  Arnaldo L. Mortatti  Maria E. C. Ferreira 《Journal of sports sciences》2020,38(5):552-558

ABSTRACT

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (p < .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.  相似文献   

The Efficacy of Preschool Developmental Indicators as a Screen for Early Primary School-Based Literacy Interventions     

Philip J. Schluter  Richard Audas  Jesse Kokaua  Brigid McNeill  Barry Taylor  Barry Milne  Gail Gillon 《Child development》2020,91(1):e59-e76

Literacy success lays the foundation for children's later educational, health, and well-being outcomes. Thus, early identification of literacy need is vital. Using data from New Zealand's national preschool health screening program for fiscal years 2010/2011–2014/2015, demographic and health variables from 255,090 children aged 4 years were related to whether they received a literacy intervention in early primary school. Overall, 20,652 (8.1%) children received an intervention. Time-to-event analysis revealed that all considered variables were significantly related to literacy intervention (all p < .01), but the full model lacked reasonable predictive power for population screening purposes (Harrell's c-statistic = .624; 95% CI [.618, .629]). Including more direct literacy measures in the national screening program is likely needed for improvement.  相似文献   

Comparing Associations Between Puberty,Ethnic–Racial Identity,Self-Concept,and Depressive Symptoms Among African American and Caribbean Black Boys     

Rona Carter  Eleanor K. Seaton  Janelle L. Blazek 《Child development》2020,91(6):2019-2041

Research on pubertal development among Black boys is limited. Addressing this gap, we examined associations between three pubertal domains (e.g., voice change, hair growth, and perceived relative timing), depressive symptoms, self-esteem, and self-efficacy, among a nationally representative sample of 395 African American and 164 Caribbean Black boys (M_age = 15 years). Moderation by ethnic–racial identity (e.g., racial centrality, racial regard) was also explored. Results indicated that for both ethnic subgroups early voice change increased self-esteem; whereas early voice change increased depressive symptoms among boys who felt society views Blacks more negatively. Buffering effects of ethnic–racial identity also varied significantly between the two groups. Findings suggest that the meaning Black boys ascribe to their ethnic–racial group may explain puberty-linked outcomes.  相似文献   

Artificial intelligence and African conceptions of personhood     

Wareham  C. S. 《Ethics and Information Technology》2021,23(2):127-136

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   

Outstanding performances during elite-standard short and middle-distance finals and the hyperandrogenism regulation—A detailed analysis of Caster Semenya’s results     

Jonathan Ospina-Betancurt  Maria S. Zakynthinaki 《Journal of sports sciences》2020,38(6):703-709

ABSTRACT

Recently, there has been much controversy over the International Association of Athletics Federation (IAAF) regulations regarding eligibility to compete and natural testosterone levels in female athletes. Much interest lies in the analysis of Caster Semenya's extraordinary performance. The objective of this work were, a) Complete an analysis of Caster Semenya's results during the 800m finals and b) search for existing similar performances by other female athletes. We analysed the results of the finals of all IAAF World Championships and Olympic Games from 1984–2016, including the 800m results of the Diamond Leagues 2016–2018. Exponential curves were fit to the data to characterise and predict performance for each event. Caster Semenya's finishing times before her ineligibility to compete and after the suspension of the IAAF hyperandrogenism regulation were found to be 1.24% and 1.49%, respectively, faster than the characteristic performance of the elite-standard in the women’s 800m final. Other female athletes, with finishing times faster than the ones predicted by the characteristic curves were also discovered. The percentage difference in performance between Caster Semenya and the other participants did not reach 3% in the 800m event. No conclusions can be drawn regarding extraordinary results ever performed during the 100m, 200m or 400m finals.  相似文献   

Key somatic variables associated with,and differences between the 4 swimming strokes     

Alan M. Nevill  Yassine Negra  Tony D. Myers  Senda Sammoud  Helmi Chaabene 《Journal of sports sciences》2020,38(7):787-794

ABSTRACT

This study identified key somatic and demographic characteristics that benefit all swimmers and, at the same time, identified further characteristics that benefit only specific swimming strokes. Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. We adopted a multiplicative, allometric regression model to identify the key characteristics associated with 100 m swimming speeds (controlling for age). The model was refined using backward elimination. Characteristics that benefited some but not all strokes were identified by introducing stroke-by-predictor variable interactions. The regression analysis revealed 7 “common” characteristics that benefited all swimmers suggesting that all swimmers benefit from having less body fat, broad shoulders and hips, a greater arm span (but shorter lower arms) and greater forearm girths with smaller relaxed arm girths. The 4 stroke-specific characteristics reveal that backstroke swimmers benefit from longer backs, a finding that can be likened to boats with longer hulls also travel faster through the water. Other stroke-by-predictor variable interactions (taken together) identified that butterfly swimmers are characterized by greater muscularity in the lower legs. These results highlight the importance of considering somatic and demographic characteristics of young swimmers for talent identification purposes (i.e., to ensure that swimmers realize their most appropriate strokes).  相似文献   

Does modality matter? A latent profile and transition analysis of sedentary behaviours among school-aged youth: The UP&DOWN study     

David Sánchez-Oliva  Rebecca M. Leech  Alberto Grao-Cruces  Irene Esteban-Cornejo  Carmen Padilla-Moledo  Oscar L. Veiga 《Journal of sports sciences》2020,38(9):1062-1069

ABSTRACT

The aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8–18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time.  相似文献   

The Use of a Mobile Learning Tool by Medical Students in Undergraduate Anatomy and its Effects on Assessment Outcomes     

Nikola Golenhofen  Felix Heindl  Claudia Grab-Kroll  David A.C. Messerer  Tobias M. Böckers  Anja Böckers 《Anatomical sciences education》2020,13(1):8-18

Hand-held devices have revolutionized communication and education in the last decade. Consequently, mobile learning (m-learning) has become popular among medical students. Nevertheless, there are relatively few studies assessing students' learning outcomes using m-learning devices. This observational study presents an anatomy m-learning tool (eMed-App), an application developed to accompany an anatomy seminar and support medical students' self-directed learning of the skeletal system. Questionnaire data describe where, how frequently, and why students used the app. Multiple choice examination results were analyzed to evaluate whether usage of the app had an effect on test scores. The eMed-App application was used by 77.5% of the students, mainly accessed by Android smartphones, and at students' homes (62.2%) in order to prepare themselves for seminar sessions (60.8%), or to review learning content (67%). Most commonly, students logged on for less than 15 minutes each time (67.8%). Frequent app users showed better test results on items covering eMed-App learning content. In addition, users also achieved better results on items that were not related to the content of the app and, thus, gained better overall test results and lower failure rates. The top quartile of test performers used the eMed-App more frequently compared to students in lower quartiles. This study demonstrated that many students, especially the high-performing ones, made use of the eMed-App. However, the app itself did not result in better outcomes, suggesting that top students might have been more motivated to use the app than students who were generally weak in anatomy.  相似文献   

Predicting the early growth of word and nonword reading fluency in a consistent syllabic orthography     

Tomohiro Inoue  George K. Georgiou  Naoko Muroya  Miyuki Hosokawa  Hisao Maekawa  Rauno Parrila 《Journal of Research in Reading》2020,43(3):364-381

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Press Credentials and Hybrid Boundary Zones: The Case of WorldNetDaily and the Standing Committee of Correspondents     

Jordan M. Foley 《Journalism Practice》2020,14(8):933-953

ABSTRACT

Press credentialing practices are a vital, yet understudied site of scholarly research on journalistic norms and practices. Press credentialing not only structures internal professional hierarchies, but they also signify the boundaries of the journalistic field itself. This paper explores the legal and theoretical implications of press credentialing to cover the United States Congress, drawing on the concepts of boundary work and journalistic authority to demonstrate the material impact of the space between fields on professional legitimation in journalism. Using WorldNetDaily (WND) as a case study, I argue that the Standing Committee of Correspondents (SCC) occupies a hybrid boundary zone between the journalistic and political fields, generating a unique tension in First Amendment jurisprudence that places journalists in a paradoxical role as both the professional embodiments of free speech and its constitutional steward. The resulting jurisdictional conflict between the SCC and WND extends the relational model of journalistic authority by articulating how journalist-state relations can fundamentally augment the process of legitimation at its fuzzy boundaries. The relevance and implications for press credentialing practices in the digital age are discussed.  相似文献