6,535 research outputs found
Reliability of DXA for the measurement of total and regional body composition in elite soccer players
No full textReliability of DXA for the measurement of total and regional body composition in elite soccer players
Fanchini M, Guido Rillo, Mattias Bruni, Carwyn Sharp
AS Roma Football Club, Roma, ITA
University of Verona, Faculty of Exercise and Sport Science, ITA;
INTRODUCTION
Dual-energy X-ray absorptiometry (DXA) is widely used for the assessment of total and regional body composition. Acquisition of the data can be done automatically with the in-built software however the software may under/overestimate regional parameters (i.e. legs). As such, the data may also be acquired by operator manual adjustment of the regions-of-interest (ROI) but the experience of the operator may influence the accuracy and reliability. In elite football monitoring leg muscle mass is relevant therefore operator adjustment may be required. The aim of this study was to examine the reliability of total and regional body composition when comparing automatic and manual ROI assessment performed by operators with different experience levels.
METHODS
Twenty-four elite soccer players (age 18 ± 1 yrs; height 179 ± 5 cm; body mass 72 ± 5 kg) from an Italian Serie-A team participated in a test-retest study. Tests were performed with Lunar iDXA (GE Healthcare Lunar, Madison, USA) and examined with in-built software (enCORE 17, GE Medical Systems Ultrasound & Primary Care Diagnostics, USA) on two different days. Total body fat mass (FM) and free fat mass (FFM) were examined as total body composition, and free fat mass of right and left legs (FFMR and FFML) were examined as regional body composition parameters. ROI were determined automatically (AROI) and by two operators with low and high experience (Low1 and High1). After two weeks, the operators were asked to do the analysis again (Low2 and High2) on the same images. Reliability was examined as Typical Error of Measurement (expressed as percentage, TEM) and Intraclass Correlation Coefficient (ICC).
RESULTS
The values were within the range 9.7-10.2 kg for FM, 58.8-59.5 kg for FFM, 10.3-12.8 kg for FFMR and 10.2-12.7 kg for FFML. The TEMs were within the range 2.0-2.4% for FM and 0.8-0.9% for FFM for all the assessment. The TEMs for FFMR were 1.4, 4.1, 1.2, 1.6, 1.3 % for AROI, Low1, High1, Low2 and High2 respectively. The TEMs for FFML were 2.0, 3.9, 1.1, 1.3, 1.1 % for AROI, Low1, High1, Low2 and High2 respectively. Low1 showed higher values of TEM for FFMR and FFML.
The ICC were within the range 0.99-1.00 for FM, 0.82-0.98 for FFMR, 0.83-0.98 for FFML and 0.99 for FFM.
DISCUSSION
The reliability of total and regional body parameters found in the present group of elite soccer players was similar to the values reported in the literature (1, 2). No significant difference was found between reliability parameters in FM, FFM however the lowest reliability found in Low1 in FFMR and FFML suggested the low experience of the operator have influenced the DXA results in his first assessment. Even if operators are familiarized with ROI customization they need experience to provide reliable outcomes.
1. Hart NH, Nimphius S, Spiteri T, Cochrane JL, Newton RU. J Sports Sci Med, 2015, 14, 620-626
2. Bilsborough JC, Greenway K, Opar D, Livingstone S, Cordy J, Coutts AJ. J Sports Sci, 2014, 19, 1821-
The Life and Letters of William Sharp and "Fiona Macleod"
No full text"William Sharp (1855-1905) conducted one of the most audacious literary deceptions of his or any time. Sharp was a Scottish poet, novelist, biographer and editor who in 1893 began to write critically and commercially successful books under the name Fiona Macleod. This was far more than just a pseudonym: he corresponded as Macleod, enlisting his sister to provide the handwriting and address, and for more than a decade ""Fiona Macleod"" duped not only the general public but such literary luminaries as William Butler Yeats and, in America, E. C. Stedman.
Sharp wrote ""I feel another self within me now more than ever; it is as if I were possessed by a spirit who must speak out"". This three-volume collection brings together Sharp’s own correspondence – a fascinating trove in its own right, by a Victorian man of letters who was on intimate terms with writers including Dante Gabriel Rossetti, Walter Pater, and George Meredith – and the Fiona Macleod letters, which bring to life Sharp’s intriguing ""second self"".
With an introduction and detailed notes by William F. Halloran, this richly rewarding collection offers a wonderful insight into the literary landscape of the time, while also investigating a strange and underappreciated phenomenon of late-nineteenth-century English literature. It is essential for scholars of the period, and it is an illuminating read for anyone interested in authorship and identity.
Do non-contact injuries occur during high-speed running in elite football? Preliminary results from a new GPS and video-based method
No full textObjectivesUnderstanding how injuries occur (inciting circumstances) is useful for developing etiological hypotheses and prevention strategies that can be tested. The aims of this study were 1) to evaluate the feasibility of a method combining video and GPS data to estimate the speed and acceleration of activities leading to injuries; 2) to use this method to analyse the inciting circumstances leading to non-contact injuries in football players.DesignRetrospective descriptive study.MethodsData collected from 46 elite players over three seasons are included. Training and matches were video recorded and external load measures were collected through Catapult Vector S7 GPS. Injury nciting circumstances were analysed through GPS measures and visual inspection.ResultsIn total 34 non-contact injuries were analysed. Sixteen out of the seventeen hamstring injuries occurred when players were running for (median and IQR) 16.75 m (8.42–26.65 m), achieved a peak speed of 29.28 km·h−1 (26.61–31.13 km·h−1) which corresponded to 87.55% of players' maximal speed (78.5% - 89.75%). Of the three adductor injuries, one occurred while the player was decelerating without the ball, one injury occurred while the player was accelerating and controlling the ball at knee level, and one injury occurred while the player was performing an instep kick. Two quadriceps injuries occurred while the players were kicking either while walking or while running.ConclusionsFrom the preliminary results reported in this study most hamstring injuries occurred when players ran > 25 km·h−1 and above 80% of their maximal speed. This study suggests that this novel approach can allow a detailed and standardised analysis of injury inciting circumstances
Vicki Potempa demonstrating at the pro-abortion rally in Sydney, New South Wales, May 2010 [picture] /
No full textTitle from acquisitions documentation.; Acquired in digital format; access copy available online.; Mode of access: Internet via World Wide Web.; Purchased from the photographer, 2010. "Vicki Potempa seen here at a pro-abortion rally in Sydney. Author and 2001 Outstanding Humanist Achiever, Vicki has been an advocate to Women's Reproductive Rights since 1966 when she underwent her own abortion"--Information supplied by photographer
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Interaction Design: Beyond Human-Computer Interaction
No full textAccomplished authors, Preece, Rogers and Sharp, have written a key new textbook on this core subject area. Interaction Design deals with a broad scope of issues, topics and paradigms that has traditionally been the scope of Human-Computer Interaction (HCI) and Interaction Design (ID). The book covers psychological and social aspects of users, interaction styles, user requirements, design approaches, usability and evaluation, traditional and future interface paradigms and the role of theory in informing design. The topics will be grounded in the design process and the aim is to present relevant issues in an integrated and coherent way, rather than assembling a collection of chapters on individual HCI topics.KEY FEATURES: This truly integrated approach to HCI provides students with background information from psychology, sociology, anthropology, information systems and computer science provides principles and skills for designing any technology through the use of many interesting and state of the art examples. The author supported, highly interactive Web Site provides resources that allow students to collaborate on experiments, participate in design competitions, collaborate on design, find resources and communicate with others. The accompanying Web Site also features examples, step-by-step exercises and templates for questionnaires
The response of intracellular signaling and muscle-protein metabolism to nutrition and exercise
No full textIn recent years, a body of literature examining the response of muscle-protein metabolism to exercise and nutrition has arisen. Developments in methods, especially stable isotopic tracer methodology, have allowed much information to be gathered in vivo in humans. The metabolic mechanism behind increased muscle mass requires that muscle-protein synthesis exceeds breakdown, i.e., net muscle-protein synthesis. Increased net muscle-protein balance may occur due to exercise, but net synthesis may occur only with the addition of nutrients, particularly a source of amino acids. The major impact of increased amino acid availability on net muscle-protein balance is due to stimulation of muscle-protein synthesis and less to inhibition of muscle-protein breakdown. Amino acids seem to stimulate muscle-protein synthesis, not only by mass action, i.e., providing substrate, but also as signals for initiation of protein synthesis. Stimulation of muscle-protein synthesis by amino acid ingestion may be linked to increased intracellular amino acid levels and/or to changing amino acid levels in the blood. Carbohydrate ingestion, most likely through the action of insulin, also may play a role in the response of muscle to exercise and nutrition. There is very little research in humans in vivo on the intracellular signaling that is linked to muscle-protein synthesis. It is clear that intracellular signaling responds to both insulin and amino acids, but the interactions with exercise are not well known; however, the details of the pathways have only just begun to be investigated, especially in humans. Delineation of these pathways is complicated, and there is little doubt that multiple intracellular signaling pathways with several levels of communication are involved in the hypertrophy process in response to nutrition and exercise. A systematic investigation of the relationship of the signaling to insulin and amino acids combined with exercise will provide important information, especially for populations vulnerable to muscle loss
The effect of branched-chain amino acid supplementation Rebuild II [TM], on cortisol levels in healthy resistance trained males
No full textComputer-mediated communication [CMC] is beginning to be used more frequently in traditional classrooms. A group of physical chemistry professors have developed Physical Chemistry On-Line [PCOL] modules designed to augment in-class instruction and engage students at geographically dispersed institutions in activities to help them learn physical chemistry concepts. These modules use context-rich scenarios with a guided-inquiry approach, and the WWW and e-mail for information distribution and communication. This allows for intra- and inter-institutional collaboration between module participants. Three modules implemented during the Fall 2000 term are evaluated in this study. In order to assess the effectiveness of PCOL, each student completed a pre-module and post-module survey, pre-module and post-module content questions, and participated in an online discussion group. The primary focus of this analysis was to determine the student's: 1) perception of on-line activities, 2) perception of on-line interactions, and 3) use of computers.Thesis (M.S.)School of Physical Educatio
A sharp exceptional set estimate for visibility
No full textA Borel set BRn is visible from xRn, if the radial projection of B with base point x has positive Hn-1 measure. I prove that if dimB>n-1, then B is visible from every point xRn\E, where E is an exceptional set with dimension dimE2(n-1)-dimB. This is the sharp bound for all n2. Many parts of the proof were already contained in a recent previous paper by P. Mattila and the author, where a weaker bound for dimE was derived as a corollary from a certain slicing theorem. Here, no improvement to the slicing result is obtained; in brief, the main observation of the present paper is that the proof method gives the optimal result, when applied directly to the visibility problem.Peer reviewe
English folk songs from the southern Appalachians : comprising two hundred and seventy-four songs and ballads with nine hundred and sixty-eight tunes, including thirty-nine tunes contributed by Olive Dame Campbell. Volume II
No full textA collection of folk songs gathered by Cecil Sharp and Olive Campbell, and edited by Maud Karples, from the Southern Appalachian Mountains. Volume two contains 135 songs, 5 hymns, 27 nursery songs, 15 jigs, and 20 play-party games.Herbert Halpert Collection. -- Includes index. -- First edition, "by Olive Dame Campbell and Cecil J. Sharp," published in 1917.Includes bibliographical references (p. 402-405)
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