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BackgroundPuberty is a critical time in the development of overweight and obesity. The aim of this study was to examine relationships between measures of adiposity, cardiovascular fitness, and biomarkers of cardiovascular disease risk in adolescents.MethodsIn a cross-sectional study design, 129 girls and 95 boys aged 12.9–14.4 years at various stages of puberty were included, along with their mothers (n = 217) and fathers (n = 207). Anthropometric assessments of adiposity were made, along with cardiovascular physical fitness, using the 20-m shuttle run test, and biomarkers associated with cardiovascular risk, including glucose, insulin, triglyceride, fibrinogen, and C-reactive protein (CRP) concentrations.ResultsWaist-to-height ratio values were similar in boys and girls and correlated positively with diastolic blood pressure, insulin, triglyceride, fibrinogen, and CRP concentrations, and inversely with cardiovascular fitness scores. Skinfold thickness measurements were higher in girls. High-molecular-weight adiponectin concentrations were lower in boys than girls, particularly in late puberty, and CRP levels were higher. Cardiovascular fitness, maternal body mass index (BMI), and paternal BMI contributed independently to the variance in waist measurements in girls and boys. Gender, triceps skinfold thickness, and weight-to-height ratio, but not parental BMI, contributed independently to the variance in cardiovascular fitness.ConclusionThere is a relationship between measures of adolescent adiposity and parental weight that involves factors other than cardiovascular fitness. Adolescent boys have relatively more abdominal fat than girls and a tendency to have a proinflammatory profile of biomarkers. These observations suggest that family and social environmental interventions are best undertaken earlier in childhood, particularly among boys. 相似文献
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ABSTRACT Ankle sprains are the most common injury in regular badminton players and usually occur at the end of a match or training. The purpose of the present study was to examine the influence of fatigue produced by badminton practice on the lower limb biomechanics of badminton players. It was hypothesized that fatigue induces ankle kinematic and lower leg muscle activity changes which may increase the risk of ankle sprain. Ankle kinematics, ankle kinetics and muscles activities of 17 regular badminton players were recorded during lateral jumps before and after an intense badminton practice session. Post-fatigue, ankle inversion at foot strike and peak ankle inversion increased (+2.6°, p = 0.003 and +2.5°, p = 0.005, respectively). EMG pre-activation within 100 ms before foot landing significantly decreased after fatigue for soleus (?23.4%, p = 0.031), gastrocnemius lateralis (?12.2%, p = 0.035), gastrocnemius medialis (?23.3%, p = 0.047) and peroneus brevis (?17.4%, p = 0.036). These results demonstrate impaired biomechanics of badminton players when fatigue increases, which may cause a greater risk of experiencing an ankle sprain injury. 相似文献
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Gergely Simon Caroline Busch Marco A. B. Andrade Julien Reboud Jonathan M. Cooper Marc P. Y. Desmulliez Mathis O. Riehle Anne L. Bernassau 《Biomicrofluidics》2021,15(1)
Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes. 相似文献
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Julien Fuchs 《Paedagogica Historica: International Journal of the History of Education》2017,53(5):602-622
AbstractThis article looks at the French state’s approach to the “colonies de vacances” between 1944 and 1958. Created in 1876 by the Reverend Bion in Zurich, these summer camps originated as a charitable institution: their initial purpose was to provide rural retreats and to restore the health of poor urban youth. Set up on French soil in 1880, these institutions gradually grew in France in the late nineteenth and early twentieth centuries. Considered both as complements to the republican school and as extensions of the “patronages” (parish unions), they were important for children and adolescents from the industrial city suburbs, and were enshrined in the leisure policies of the Popular Front from 1936 onwards. After the Second World War, summer camps in France became a major social institution (300,000 children went to summer camps in 1945, 900,000 in 1949) in response to both hygiene and educational needs. Based on the archives of the Directorate of Youth Movements and Popular Education (1944–1947) and the General Directorate of Youth and Sports (1948–1958), this article aims to examine the politics behind the organisation of these summer camps and to demonstrate the social and political importance of these popular educational institutions which, in 1957, involved 1.35 million French children and teenagers. Although the history of French summer camp federations (UFCV, CEMEA, CPVC, UFOVAL, etc.) has been widely studied, how the state sees its role and influences these organisations has mostly been considered indirectly. The intention is to show that among the educational, cultural and sports policies implemented during the Fourth Republic in France, those related to the organisation of “colonies de vacances”, and therefore the organisation of holidays for a very large number of children and teenagers, occupy a significant place. In 1944, the summer camps were widely supported by the French state, which also planned to regulate this booming sector. The creation of qualifications for summer camp staff and directors in 1949 obliged organisations to start training schemes: they trained staff and directors to work in the municipal camps, associations, etc. Security issues led to the state tightening control of the summer camps, their recruitment and their activities. There was a great deal of political investment in these “colonies de vacances” during this period, and this was reflected in the creation of a Ministerial Education Committee in 1950, a general and regional body of inspectors for these camps, etc. However, the considerable expansion of summer camps posed increasing problems at the national political level resulting in changes to the initial subsidy policies. The State played a major part in crucial issues such as the sociological diversification of these institutions and the changes in their social role according to evolving sociocultural trend. The fact remains that the “colonies de vacances” were for the French state a centrepiece of the “popular education” that the political actors of the Fourth Republic wanted to implement in order to build the France of the post-war period.. 相似文献
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We investigated differences between field-study classrooms and traditional science classrooms in terms of the learning environment and students’ attitudes to science, as well as the differential effectiveness of field-study classrooms for students differing in sex and English proficiency. A modified version of selected scales from the What Is Happening In this Class? questionnaire was used to assess the learning environment, whereas students’ attitudes were assessed with a shortened version of a scale from the Test of Science Related Attitudes. A sample of 765 grade 5 students from 17 schools responded to the learning environment and attitude scales in terms of both their traditional science classrooms and classrooms at a field-study centre in Florida. Large effect sizes supported the effectiveness of the field-studies classroom in terms of both the learning environment and student attitudes. Relative to the home school science class, the field-study class was considerably more effective for students with limited English proficiency than for native English speakers. 相似文献
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Kathleen H. Miles Bradley Clark Julien D. Périard Roland Goecke Kevin G. Thompson 《Journal of sports sciences》2018,36(8):934-941
The primary aim of this study was to determine whether facial feature tracking reliably measures changes in facial movement across varying exercise intensities. Fifteen cyclists completed three, incremental intensity, cycling trials to exhaustion while their faces were recorded with video cameras. Facial feature tracking was found to be a moderately reliable measure of facial movement during incremental intensity cycling (intra-class correlation coefficient = 0.65–0.68). Facial movement (whole face (WF), upper face (UF), lower face (LF) and head movement (HM)) increased with exercise intensity, from lactate threshold one (LT1) until attainment of maximal aerobic power (MAP) (WF 3464 ± 3364mm, P < 0.005; UF 1961 ± 1779mm, P = 0.002; LF 1608 ± 1404mm, P = 0.002; HM 849 ± 642mm, P < 0.001). UF movement was greater than LF movement at all exercise intensities (UF minus LF at: LT1, 1048 ± 383mm; LT2, 1208 ± 611mm; MAP, 1401 ± 712mm; P < 0.001). Significant medium to large non-linear relationships were found between facial movement and power output (r2 = 0.24–0.31), HR (r2 = 0.26–0.33), [La?] (r2 = 0.33–0.44) and RPE (r2 = 0.38–0.45). The findings demonstrate the potential utility of facial feature tracking as a non-invasive, psychophysiological measure to potentially assess exercise intensity. 相似文献
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Julien Caunter Stanley J. Solomon Jerry Lewis William Bayer Alan Rosenthal 《Communication Booknotes Quarterly》2013,44(4):4-6
Julien Caunter's How to Make Movie Magic in Amateur Films (Philadelphia: Chilton Books, 1971---price not known) Stanley J. Solomon The Film Idea (New York: Harcourt, Brace, Javanovich, March 1972---$4.95 paper) Jerry Lewis' The Total Filmmaker (New York: Random House, 1971---$6.95) William Bayer's Breaking Through, Selling Out, Dropping Dead, and Other Notes on Film Making (New York: Macmillan, 1971---$5.95) Alan Rosenthal (ed.) The New Documentary in Action: A Casebook in Film Making (Berkeley: University of California Press, 1971---$11.95) 相似文献
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Herbert W. Marsh Julien P. Chanal Philippe G. Sarrazin 《Journal of sports sciences》2013,31(1):101-111
Abstract A large body of research in support of the reciprocal effects model of causal ordering demonstrates that prior academic self-concept predicts subsequent academic achievement beyond what can be explained in terms of prior achievement. Here we evaluate the generalizability of this support for the reciprocal effects model to a physical activity context in which achievement is reflected in gymnastics skills on a standardized gymnastics performance test evaluated by expert judges. Based on the responses of 376 adolescents collected at the start (T1) and end (T2) of a gymnastics training programme, there is support for a reciprocal effects model in which there are significant paths leading from both T1 gymnastics self-concept to T2 gymnastics skills and from T1 gymnastics skills to T2 self-concept. Although there were gender and age effects (girls and older participants had better gymnastics skills, boys had higher self-concepts), multiple group structural equation models indicated that support for the reciprocal effects model generalized over responses by boys and girls. In summary, self-concept and performance are both determinants and consequences of each other. 相似文献
10.
Virginie Nicaise Julien E. Bois Stuart J. Fairclough Anthony J. Amorose Geneviève Cogérino 《Journal of sports sciences》2013,31(8):915-926
Abstract In this study, we examined the perceptions of physical education (PE) teachers' feedback patterns with female and male high school students (n = 325). Eight physical education teachers (4 females and 4 males) were involved. We examined (a) whether teachers' feedback was perceived differently by boys and girls, and how the sex of the teacher influenced these perceptions, and (b) the effects of types of feedback (praise, no response-successful, encouragement, technical information, criticism, no response-unsuccessful, and teacher's invested time) on students' perceived competence, effort, enjoyment, and their PE performance. A multivariate analysis revealed an interaction between teacher and student gender on perceptions of teacher feedback. Hierarchical regression analyses highlighted that the perceived feedback significantly predicted students' perceptions of competence (ΔR 2 = 0.088), effort (ΔR 2 = 0.119), enjoyment (ΔR 2 = 0.085), and their PE performance (ΔR 2 = 0.039) after accounting for the gender of the students and teachers and the students' initial PE performance. The perceptions of praise and teachers' invested time were positively linked with the dependent variables, whereas encouragement and technical information and criticism were negatively linked. The findings are discussed in terms of teaching effectiveness and gender equity. 相似文献