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271.
The purpose of this study was to analyze the kinematic variables that determine the performance of the standing long jump in children 6- to 12-years-old. There were 121 healthy children (58 girls) recorded while they performed the standing long jump test. All kinematic variables showed a significant correlation with calculated jump distance and measured jump distance, except for the knee joint angle at maximum shoulder extension angle, ankle joint angle at maximum shoulder extension angle, and shoulder joint angle at maximum knee flexion angle. Stepwise multiple regression analysis showed that sex, age, and body mass index accounted for 51.1% of the jump distance variance. Among all the kinematic variables, take-off distance and take-off speed were accounted for the most of the variation in the jump distance. Physical education teachers and coaches should consider special attention to these anthropometrics and kinematic aspects in improving the standing long jump performance in children.  相似文献   
272.
This study aimed to analyse the association between socioeconomic status (SES) and fatness and fitness in preschoolers. 2,638 preschoolers (3–5 years old; 47.2% girls) participated. SES was estimated from the parental educational and occupational levels, and the marital status. Fatness was assessed by body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Physical fitness components were assessed using the PREFIT battery. Preschoolers whose parents had higher educational levels had lower fatness (P < 0.05). BMI significantly differed across occupational levels of each parent (P < 0.05) and WHtR across paternal levels (P = 0.004). Musculoskeletal fitness was different across any SES factor (P < 0.05), except handgrip across paternal occupational levels (P ≥ 0.05). Preschoolers with high paternal occupation had higher speed/agility (P = 0.005), and those with high or low maternal education had higher VO2max (P = 0.046). Odds of being obese and having low musculoskeletal fitness was lower as SES was higher (P < 0.05). Those with married parents had higher cardiorespiratory fitness than single-parent ones (P = 0.010). School-based interventions should be aware of that children with low SES are at a higher risk of obesity and low fitness already in the first years of life.  相似文献   
273.
Purpose:The aim of the present study was to analyze the associations of youths' sedentary behavior(SB) with parents' and siblings' SB and physical activity(PA),as well as the associations of youths' coparticipation with parents,siblings,and friends in PA and SB with youths' SB.Methods:The sample consisted of 1543 youths(12.02±2.51 years;788 boys) enrolled in the baseline cohort of the UP&DOWN study.SB was assessed by accelerometry and questionnaire.Participants reported the time spent by their parents and siblings watching television,playing videogames,surfing the Internet,sitting/resting,and doing PA.Further,participants reported coparticipation with parents,siblings,and friends in these activities.Linear mixed models,including school and city as random effects,were performed.Results:Parents' television time was positively associated with youths' screen-based SB.Coparticipation with friends in playing videogames(in boys) and in surfing the Internet(in girls) showed a positive association with screen-based SB and a negative association with educational-based SB.Moreover,coparticipation with siblings and friends in PA was inversely associated with accelerometer-based SB in boys and girls.Conclusion:Our results emphasize the important role of social modeling in the development of sedentary lifestyles in youths.Interventions aimed at reducing health risk behaviors in youths could be more effective if they are oriented from a social perspective that involves their families and networks of their closest friends.  相似文献   
274.
Serum ceruloplasmin is one of the most commonly used screening tests for Wilson’s disease. However immunological assays for ceruloplasmin are not recommended for diagnosis and management of Wilson’s disease through calculation of free copper index. Enzymatic methods using non-physiological substrates have toxicity and stability problems, making them difficult to automate. Ferroxidase assays may be a satisfactory alternative for measuring serum ceruloplasmin. The o-dianisidine hydrochloride manual method for estimation of serum ceruloplasmin enzyme activity was compared with an automated method using the ferroxidase activity of ceruloplasmin in measurement in a double blind study in 91 consecutive patients screened for Wilson’s disease. The o-dianisidine and ferroxidase methods both successfully identified 7 patients with Wilson’s disease. Values for these 7 patients in the o-dianisidine and ferroxidase methods were median 5.0 (range 0–16.0 U/L) and median 45.0 (range 4–166 U/L) respectively. There were 7 other positive values (<62 U/L) with the o-diansidine method and 2 (<200 U/L) with the ferroxidase method, where WD was not confirmed. ROC curves for both methods showed area under the curve of 0.998 for o-dianisidine and 0.997 for ferroxidase. Using literature cut off values of 62 U/L and 200 U/L respectively both methods had 100% sensitivity and specificity was 91.7% (o-dianisidine) and 97.6% (ferroxidase). For the o-dianisidine assay, specificity was improved to 98.8% using a cut off of 22.5 U/L. In the 84 persons (46 adults and 38 children) in whom the diagnosis of Wilson’s disease was not established, the mean value for ceruloplasmin activity by the o-dianisidine and ferroxidase methods was 124.7 ± 48.7 U/L and 571.4 ± 168.1 U/L respectively. There were no significant differences between sex or age of patients (p > 0.29). In a subsequent evaluation with 372 specimens, the Pearson correlation coefficient between the assays was 0.908, p < 0.01, slope 4.06, intercept 265.8, with the manual assay as the x-axis. The ferroxidase assay is a suitable replacement for the o-dianisidine assay in detecting patients with Wilson’s disease.  相似文献   
275.
Shock absorption and stability during landings is provided by both, gymnast ability and mat properties. The aims of this study were to determine the influence of different mat constructions on their energy absorption and stability capabilities, and to analyse how these properties affect gymnast's plantar pressures as well as subjective mat perception during landing. Six mats were tested using a standard mechanical drop test. In addition, plantar pressures and subjective perception during landing were obtained from 15 expert gymnasts. The different mats influenced plantar pressures and gymnasts' subjective perception during landing of gymnasts. Significant correlations between plantar pressures at the medial metatarsal and lateral metatarsal zones of the gymnasts' feet with the different shock absorption characteristics of the mats were found. However, subjective perception tests were not able to discriminate mat functionality between the six mats as no significant correlations between the mechanical mat properties with the subjective perception of these properties were found. This study demonstrated that plantar pressures are a useful tool for discriminating different landing mats. Using similar approaches, ideally including kinematics as well, could help us in our understanding about the influences of different mats upon gymnast-mat interaction.  相似文献   
276.
We study the employment and sales growth of entrepreneurial ventures that have received a government-sponsored participative loan (PL), a hybrid form of financing between debt and equity. We use propensity-score matching (PSM) and instrumental variable analysis (2SLS) to study a sample of 512 entrepreneurial ventures that received a PL from a Spanish government agency between 2005 and 2011. We find evidence that PLs significantly boosted their beneficiaries’ employment and sales. In the two years following loan issuance, a 1-million-Euro PL generated an increase in average employment of between 12.1 (PSM) and 14.7 (2SLS) units and an increase in sales of between 1.09 and 1.97 million Euro relative to the average for the two years prior to loan issuance. The effect is larger for high-tech, young and small entrepreneurial ventures and for those that received a PL during the global financial crisis. The effect on growth is significant and stable, and PLs increase their beneficiaries’ annual growth by 10.6% for employment and by 18.0% for sales. We do not find evidence of industry or regional spillovers, nor do we find differences in the probability of survival of PL beneficiaries after we control for their characteristics.  相似文献   
277.
Science is undergoing a crisis that has been referred to, since the early 21st century, as a crisis of confidence and a crisis of replication. This article reviews questions pertaining to the replication crisis; questions addressing the quality and credibility of the sciences; specifically, questions linked to what are known as false positives, null results, and questionable research practices (p-hacking, harking, cherry-picking). As an outcome of our review and analysis, a set of recommendations to strengthen the elaboration of reliable and valid research studies is provided. Changes are needed in order to foment meta-research, open science practices and replication studies; notably, changes are needed in the instruction of research methods; in the use and interpretation of statistical data, as well as in research culture in general. We conclude that the replication crisis presents an opportunity to improve research practices and the quality of scientific production in all fields of research, including research in education.  相似文献   
278.
ABSTRACT

The aim of this study was to assess the influence of different bike positions on the perception of fatigue, pain and comfort. Twenty cyclists underwent three tests that involved cycling for 45 min at their individual 50% peak aerobic power output while adopting different positions on the bike. Participants performed the cycling tests adopting three positions defined by two parameters (knee flexion angle [20°, 30°, 40°] and trunk flexion angle [35°, 45°, 55°]) in random order. Angles were measured using a 2D motion analysis system during cycling and applying Fonda’s correction factor. Perceptions of comfort, fatigue and pain were reported before the end of each test. The combination of 40° knee flexion and 35° trunk flexion was perceived as the most uncomfortable position. Moreover, greater knee flexion had a negative effect on trunk comfort, accompanied by greater levels of fatigue and pain perception in the anterior part of the thigh and knee. In conclusion, cyclists perceived the most comfortable position to be when the saddle height was within the recommended knee angle (30° calculated from the offset position or 40 ± 4.0° of absolute value). Upright trunk was found to be the most comfortable position for recreational cyclists, where aerodynamics is not so important. Cyclists’ bike perceptions should be taken into account when it comes to choosing the most beneficial position, since this can play a role in injury prevention and enhance cycling performance.  相似文献   
279.
A comprehensive school and community wellness plan was developed and implemented to transform Lemon Grove Academy for the Sciences and Humanities, an urban school, where student achievement and faculty satisfaction has soared. The school has become the center for the local neighborhood where culture, language, and equity are valued. The school's Comprehensive Wellness Plan includes student wellness, family wellness, staff/faculty wellness, and environmental wellness.  相似文献   
280.
Using data from a national survey of school psychologists we investigated (a) the extent to which school psychologists supported students' social–emotional and behavioral well-being using data and evidence-based practices programming, (b) how facilitators and barriers impacted school psychologists' service delivery in these areas, and (c) how participants' demographic characteristics predicted facilitators to these practices. The survey was administered to randomly selected National Association of School Psychologists' members. One hundred ninety-nine full-time, school-based school psychologists (24% response rate) completed the survey. Results indicated more practitioners reported using data to design, implement, and evaluate evidence-based strategies for social–emotional and behavioral supports (M = 3.32, SD = 0.90) than reported using evidence-based strategies themselves in these same areas (M = 3.10, SD = 1.05). School psychologists who reported more facilitators were more likely to use data and engage in evidence-based practices related to social–emotional and behavioral supports for students. Results also indicated certain barriers impeded school psychologists' practices in these areas. Few demographic characteristics predicted the presence of facilitators or barriers. Findings from the current study extend the extant literature by providing empirical data on facilitators of and barriers to services related to school psychologists' use of data and evidence-based practices in these areas.  相似文献   
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