The accuracy and precision of DXA for assessing body composition in team sport athletes     

Johann Christopher Bilsborough  Kate Greenway  David Opar  Steuart Livingstone  Justin Cordy  Aaron James Coutts 《Journal of sports sciences》2013,31(19):1821-1828

Abstract

This study determined the precision of pencil and fan beam dual-energy X-ray absorptiometry (DXA) devices for assessing body composition in professional Australian Football players. Thirty-six professional Australian Football players, in two groups (fan DXA, N = 22; pencil DXA, N = 25), underwent two consecutive DXA scans. A whole body phantom with known values for fat mass, bone mineral content and fat-free soft tissue mass was also used to validate each DXA device. Additionally, the criterion phantom was scanned 20 times by each DXA to assess reliability. Test–retest reliability of DXA anthropometric measures were derived from repeated fan and pencil DXA scans. Fat-free soft tissue mass and bone mineral content from both DXA units showed strong correlations with, and trivial differences to, the criterion phantom values. Fat mass from both DXA showed moderate correlations with criterion measures (pencil: r = 0.64; fan: r = 0.67) and moderate differences with the criterion value. The limits of agreement were similar for both fan beam DXA and pencil beam DXA (fan: fat-free soft tissue mass = ?1650 ± 179 g, fat mass = ?357 ± 316 g, bone mineral content = 289 ± 122 g; pencil: fat-free soft tissue mass = ?1701 ± 257 g, fat mass = ?359 ± 326 g, bone mineral content = 177 ± 117 g). DXA also showed excellent precision for bone mineral content (coefficient of variation (%CV) fan = 0.6%; pencil = 1.5%) and fat-free soft tissue mass (%CV fan = 0.3%; pencil = 0.5%) and acceptable reliability for fat measures (%CV fan: fat mass = 2.5%, percent body fat = 2.5%; pencil: fat mass = 5.9%, percent body fat = 5.7%). Both DXA provide precise measures of fat-free soft tissue mass and bone mineral content in lean Australian Football players. DXA-derived fat-free soft tissue mass and bone mineral content are suitable for assessing body composition in lean team sport athletes.  相似文献   

Sleep restriction impairs maximal jump performance and joint coordination in elite athletes     

Cheri D. Mah  Aaron J. Sparks  Michael A. Samaan  Richard B. Souza  Anthony Luke 《Journal of sports sciences》2013,31(17):1981-1988

ABSTRACT

The study objective was to examine the effects of three days of sleep restriction on maximal jump performance and joint coordination. Eleven elite cyclists obtained a one-week baseline of habitual sleep then restricted sleep to 4 h/night (SR) for three nights assessed through self-report and actigraphy. Pre and post-intervention measures were a box drop maximal vertical jump with 3D motion capture to assess physical performance and biomechanical changes, and Psychomotor Vigilance Task (PVT) assessed changes in response time. Associations between biomechanical, physical, and cognitive performance measures were assessed. Participants restricted reported sleep from 7.4 ± 0.5 h/night at baseline to 4.0 ± 0.2 h/night and actigraphy indicated 6.7 ± 0.7 to 3.7 ± 0.2 h/night. Following SR, jump height decreased (0.44 ± 0.09 vs. 0.42 ± 0.10 m, p = 0.02, g = 0.21). Hip sagittal/knee frontal (Δ15.5°, p = 0.04, g = 0.40) and hip frontal/knee frontal (Δ11.0°, p < 0.01, g = 0.44) plane coordination variability increased after SR. Hip sagittal/knee frontal plane coordination variability after SR was associated with increasingly slower PVT response time (r = 0.63, p = 0.03). These findings suggest SR for three days decreased maximal jump performance. SR increased joint coordination variability and was associated with greater impairment in response time. SR leads to deviations from preferred movement patterns, which may have implications for decrements in athlete performance and increased injury risk.  相似文献   

Componential Model of Reading (CMR): Validation Studies     

RM Joshi  PG Aaron 《Journal of learning disabilities》2012,45(5):387-390

The three current models of identifying learning disabilities: discrepancy model, RtI, and Componential Model of reading are discussed in terms of their utility.  相似文献   

Teleconsultation as the New Frontier of Educational and Psychological Consultation: Introduction to the Special Issue     

Aaron J Fischer  William P. Erchul  Brandon K. Schultz 《Journal of educational and psychological consultation》2018,28(3):249-254

ABSTRACT

In this lead-in article, we define teleconsultation as the delivery of consultative services through videoconferencing and other technologies. We then describe the emergence and potential positive impact of teleconsultation in schools. Finally, we introduce the articles that make up this special issue of the Journal of Educational and Psychological Consultation.  相似文献   

When Is Teleconsultation Acceptable to School Psychologists?     

Brandon K. Schultz  Kimberly A Zoder-Martell  Aaron Fischer  Melissa A Collier-Meek  William P Erchul  Alexander M Schoemann 《Journal of educational and psychological consultation》2018,28(3):279-296

ABSTRACT

School psychologists report a desire to increase consultation with teachers but are limited by competing job demands. Consultation via videoconference (i.e., teleconsultation) offers one possible means of increasing consultant availability to teachers, but little is known about the acceptability of this technology in actual practice. In this exploratory study, we conducted an online survey to assess the conditions under which school consultants would use teleconsultation to assist teachers remotely. Sixty-two school psychology practitioners, trainers, and trainees completed a choice-based conjoint survey designed to assess teleconsultation acceptability in the context of varying commute times, consultee comfort levels, and student problem severities. Findings suggest important differences in teleconsultation acceptability in the context of real-world tradeoffs. Implications of these results are discussed, as well as the potential for using conjoint analysis to better understand technology decisions among school consultants.  相似文献   

Beyond traditional literacy: Learning and transformative practices using ICT     

Therese?KeaneEmail author  William?F.?Keane  Aaron?S.?Blicblau 《Education and Information Technologies》2016,21(4):769-781

Educators, government bodies and employers have acknowledged the need for modern learners to acquire 21st century skills using information and communication technologies, to personalise student learning. Students need broader skills than the 3Rs (reading, writing and arithmetic) to operate in the 21st century. These broader skills known as the 4Cs include: creativity, communication, collaboration and critical thinking. The use of information and communication technologies is crucial in developing the 4Cs in conjunction with understanding how learning takes place. However, simply using technology does not guarantee that deep learning will occur. The use of technology needs to align and adapt with our knowledge of learning to be able to operate in a transformative space. This paper is designed to link the understandings of deep learning, 21st century skills and appropriate use of information and communication technologies to provide direction to educators who wish to lead in a technological environment of change.  相似文献   

Cognitive Techniques as a Means for Facilitating Supervisee Development     

Aaron Kindsvatter  Darcy Haag Granello  Jill Duba 《Counselor Education & Supervision》2008,47(3):179-192

During periods of uncertainty or psychological distress, a supervisee may encounter or develop rigid or unhelpful thinking patterns that could delay development by promoting discouraging realities and experiences. Such cognitive experiences often are so subtle that they occur outside of the supervisee's immediate awareness. This article explores how the cognitive model of counseling could be used in supervision as a guide to help the supervisor and supervisee discover and modify negative thought processes.  相似文献   

Disclosure and secrecy in adolescent-parent relationships   总被引：3，自引：0，他引：3  

Smetana JG  Metzger A  Gettman DC  Campione-Barr N 《Child development》2006,77(1):201-217

Beliefs about parents' legitimate authority and adolescents' obligations to disclose to parents and actual disclosure and secrecy in different domains were examined in 276 ethnically diverse, lower middle-class 9th and 12th graders (Ms=14.62 and 17.40 years) and their parents (n=249). Adolescents were seen as more obligated to disclose prudential issues and less obligated to disclose personal than moral, conventional, and multifaceted issues; parents viewed adolescents as more obligated to disclose to parents than adolescents perceived themselves to be. Adolescents disclosed more to mothers than to fathers, particularly regarding personal issues, but mothers overestimated girls' disclosure. Greater trust, perceived obligations to disclose, and, for personal issues, more parental acceptance and psychological control predicted more disclosure and less secrecy.  相似文献   

Contextual influences and athlete attitudes to drugs in sport     

Aaron C.T. Smith  Bob Stewart  Sunny Oliver-Bennetts  Sharyn McDonald  Lynley Ingerson  Alastair Anderson  Geoff Dickson  Paul Emery  Fiona Graetz 《Sport Management Review》2010,13(3):181-197

This article reports on 11 narrative-based case histories which sought to: (1) uncover the attitudes of players and athletes to drugs in sport, and (2) explore contextual factors influencing the formation of those attitudes as informed by social ecology theory. Overall, participants viewed the use of banned performance-enhancing substances as cheating, ‘hard’ non-performance-enhancing recreational or illicit substances as unwise, legal non-performance-enhancing substances as acceptable, and legal performance-enhancing substances as essential. In short, attitudes were sometimes quite libertarian, and contingent upon first, the legality of the substance, and second, its performance impact. Results also indicated that athletes’ attitudes about drugs were fundamentally shaped by sport's culture. Other significant factors included its commercial scale, closely identifiable others, early experiences and critical incidents of players and athletes, and their level of performance.  相似文献   

An Integrative Approach to Portfolio Evaluation for Teacher Licensure   总被引：3，自引：0，他引：3  

Pamela A. Moss  Aaron M. Schutz  Kathleen M. Collins 《Journal of Personnel Evaluation in Education》1998,12(2):139-161

The purpose of our overall research agenda is to develop and evaluate a methodology for the assessment of teachers in which experienced teachers, serving as judges, engage in dialogue to integrate multiple sources of evidence about a candidate to reach a sound conclusion. The project that provides the venue for this research agenda is the Interstate New Teacher Assessment and Support Consortium (INTASC), which is developing a portfolio assessment system to assist participating states in making a decision about teacher licensure. To develop the theoretical foundation necessary to support and evaluate such dialogic and integrative assessment practices, we turn, in part, to the tradition of philosophical hermeneutics, as a complement to psychometrics. In this article, we characterize and assess the processes in which judges, trying out an integrative approach to portfolio evaluation for the first time, engage as they collaboratively construct and document their conclusions, and we locate this work in the larger research agenda. The premise of this project, which is being carefully evaluated in the course of inquiry, is that these integrative practices cannot only lead to an epistemologically sound evaluation of teaching but also promote an ongoing professional dialogue of critical reflection on teaching practice.  相似文献