Reference power values for the jump squat exercise in elite athletes: A multicenter study     

Pedro L. Valenzuela  Michael McGuigan  Guillermo Sánchez-Martínez  Elaia Torrontegi  Javier Vázquez-Carrión  Zigor Montalvo 《Journal of sports sciences》2020,38(19):2273-2278

ABSTRACT

The present study aimed to provide reference values for lower-limb muscle power assessed during the incremental jump squat (JS) test in elite athletes (i.e., professional athletes competing at international level). We pooled data from all JS tests performed by elite athletes of different sports in two high-performance centres between 2015 and 2019, and computed reference values (i.e., terciles) for mean power (MP), mean propulsive power (MPP), and peak power (PP). Reference values were obtained from 684 elite athletes (458 male and 226 female) of 16 different sports (boxing, judo, karate, fencing, taekwondo, wrestling, basketball, soccer, futsal, handball, rugby union, badminton, tennis, long distance running, triathlon, and sprinting). Significant differences (p < 0.001) were found between male and female athletes for MP (7.47 ± 1.93 and 6.15 ± 1.68 W·Kg^?1, respectively), MPP (10.50 ± 2.75 and 8.63 ± 2.43 W·Kg^?1), and PP (23.64 ± 6.12 and 19.35 ± 5.49 W·Kg^?1). However, the velocity at which these power measures was attained seemed to be independent of sex (~0.95, 1.00 and 2.00 m·s^?1 for mean, mean propulsive, and peak velocity, respectively) and homogeneous across different sport disciplines (coefficient of variation <10%). These data can be used to classify athletes’ power capabilities, and the optimum velocity ranges provided here could be useful for training purposes.  相似文献   

Depression and Anxiety in the Postnatal Period: An Examination of Infants’ Home Language Environment,Vocalizations, and Expressive Language Abilities     

Ruth Brookman  Marina Kalashnikova  Janet Conti  Nan Xu Rattanasone  Kerry-Ann Grant  Katherine Demuth  Denis Burnham 《Child development》2020,91(6):e1211-e1230

This longitudinal study investigated the effects of maternal emotional health concerns, on infants’ home language environment, vocalization quantity, and expressive language skills. Mothers and their infants (at 6 and 12 months; 21 mothers with depression and or anxiety and 21 controls) provided day-long home-language recordings. Compared with controls, risk group recordings contained fewer mother–infant conversational turns and infant vocalizations, but daily number of adult word counts showed no group difference. Furthermore, conversational turns and infant vocalizations were stronger predictors of infants’ 18-month vocabulary size than depression and anxiety measures. However, anxiety levels moderated the effect of conversational turns on vocabulary size. These results suggest that variability in mothers’ emotional health influences infants’ language environment and later language ability.  相似文献   

Unraveling the Relation Between Reading Comprehension and Print Exposure     

Florina Erbeli  Elsje van Bergen  Sara A. Hart 《Child development》2020,91(5):1548-1562

The purpose of this study was to test the directionality of influence between reading comprehension (RC) and print exposure (PE), thereby estimating genetic and environmental effects of this relation. The sample consisted of 910 twins in fourth through ninth grades (M_age = 12.33 years, SD = 1.41) from the Florida Twin Project on Reading, Behavior, and Environment. Using direction-of-causation model in a twin design, results supported a direction of influence running from RC to PE. This relation was underpinned by genetic and environmental factors of RC as well as PE. Implications for reading education are discussed.  相似文献   

Opening the door: Physical infrastructure,school leaders’ work-related social interactions,and sustainable educational improvement     

《Teaching and Teacher Education》2020

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The centrality of immigrant students within teacher-student interaction networks: A relational approach to educational inclusion     

《Teaching and Teacher Education》2020

The conceptualizations of educational inclusion, previously restricted to securing access to formal education, recently highlight the promotion of equitable social and academic relations as well. This study investigates the inclusion of students with immigrant background within their class’ teacher-student interaction networks, while distinguishing by the initiator and content of interactions. Data from 38 Chilean mathematics teachers/classrooms and 933 seventh graders were collected and analyzed using systematic observation, social network visualization and multilevel models. Results show that the inclusion of students depends significantly on their country of origin. There is also significant variation in teacher-immigrant student interactions across classrooms.  相似文献   

What should teacher educators know about technology? Perspectives and self-assessments     

《Teaching and Teacher Education》2020

This article offers a first look at teacher educators’ (N = 336) perceptions of their technology competencies based on the Teacher Educator Technology Competencies (TETCs; Foulger, Graziano, Schmidt-Crawford, & Slykhuis, 2017). The participants generally rated their competence levels highly in relation to the TETCs. Although many participants reported that the TETCs adequately reflected the competencies required of them, they suggested various additions and changes to the TETCs. This mixed-method study advances understanding of teacher educators’ perceptions of the importance of various competences to their work and offers feedback from the field regarding which competencies might be missing from the TETCs.  相似文献   

Positivity and quality of college life of business students: The mediating role of learning approaches     

《Studies in Educational Evaluation》2020

Drawing upon the causal agency theory, this study examined the direct and indirect (via learning approaches) links between positivity and quality of college life (QCL) of business students in a transitioning market, Vietnam. Two studies were conducted to test these relationships using structural equation modeling. Findings from study 1, based on a sample of 428 business students, showed that positivity was positively related to QCL. Further, deep learning approaches mediated the relationship between positivity and QCL. Findings from study 2, based on a sample of 416 business students, reconfirmed the role of positivity in QCL. However, the indirect relationship between positivity and QCL was not significant, demonstrating that surface learning approaches did not mediate the relationship between positivity and QCL. The findings contribute to the literature on positivity in higher education by confirming the overarching role that positivity plays, directly and indirectly (via deep learning approaches), in QCL.  相似文献   

Second Language Assessment and Action Research,edited by Anne Burns and Hanan Khalifa,Cambridge, UCLES/Cambridge University Press, 2017, 327 pp., €39.70 (hardback), ISBN 978-1-108-43670-0     

Xiangdong Gu  Yiting Duan 《Assessment & Evaluation in Higher Education》2020,45(1):165-167

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Acculturative stress and cultural identity styles as predictors of psychosocial functioning in Hispanic Americans     

《Int J Intercult Relat》2021

We test acculturative stress, Hybrid (HIS) and Alternating (AIS) Identity Styles, and their interaction effects as predictors of psychosocial functioning over a 12-day period among Hispanic American university students. Participants completed measures of acculturative stress, HIS, AIS, and internalizing (anxiety and depression) and externalizing (social aggression and rule-breaking) symptoms on Day 1; on Day 12 they completed the symptom measures a second time. Structural equation modelling was used to examine the Day 1 effects of acculturative stress, cultural identity styles, and their interactions on Day 12 symptoms controlling for the Day 1 symptoms. We hypothesized that acculturative stress would predict more, and the HIS would predict fewer, symptoms and that the AIS would moderate the relationship between acculturative stress and symptoms over time. Results indicated that: (1) acculturative stress predicted an increase in internalizing symptoms; (2) the HIS predicted a decrease in internalizing and externalizing symptoms; and (3) the AIS attenuated the relationship between acculturative stress and externalizing symptoms. The results are discussed in relation to the distinctive features of internalizing and externalizing symptoms, and recommendations for future research are advanced.  相似文献   

Rethinking the intention to behavior link in information technology use: Critical review and research directions     

《International Journal of Information Management》2021

Extant research on technology acceptance has devoted considerable attention to the relationship between behavioral intention (BI) and system use (SU) over time. However, the empirical results have been mixed—studies have found BI to both influence and not influence SU. Studies that examined the BI→SU relationship have employed different research models and research designs. Prior research models have examined direct effects on SU, indirect effects on SU through BI, the moderator effects on BI→SU, and the mediating role of BI in BI→SU. Studies have employed different types of respondents, information technologies, geographic regions, voluntariness, and measurement designs. This study proposes that such differences in research models and designs contribute to the mixed results for BI→SU, and reports a meta-analysis of findings reported in 113 prior studies along with a critical review of the BI→SU relationship. While no significant differences were found in the results for the BI→SU relationship across various research design characteristics, this study finds that the measurement of SU has been conflated with future and current or past behavior, direct and indirect effects on SU impact BI→SU, BI is modeled to fully and partially mediate the effects of other variables on SU, and moderators for the BI→SU relationship may be necessary. This study identifies several directions for future research and underlines the need to rethink the link between BI and SU.  相似文献