Accurate assessment of the brake torque on a rope-braked cycle ergometer

Sports Engineering - A Monark cycle ergometer is a device globally used in physiological studies to measure the work and energy levels of exercising humans. In this paper a rope-braked cycle...     

儿童青少年运动员的营养需要

1. 儿童青少年运动员应该食用多样化的食物，其中，蛋白质应占膳食总能量的12％-15％，碳水化合物至少占55％，而脂肪至多占30％。日常生活中如何吃才能满足这些要求呢？膳食指南宝塔提供了一条可行之道。2.有些营养素对热爱运动的儿童青少年运动员非常重要，要保证摄入充足，这些营养素是碳水化合物（包括纤维素）、维生素B6、维生素D、铁、钙、镁、锌、铬。科学合理、包罗各类食物的平衡膳食，对青少年运动员最大程度地全面摄取各种营养素，满足生长发育和运动训练的需要，是非常必要的。3.鼓励儿童青少年运动员在运动训练前、中、后进行补液，以避免脱水的发生。4.如果膳食合理平衡，就没必要额外补充营养品。     

Comparison of oil and egg tempera paint systems using time-of-flight secondary ion mass spectrometry

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is quickly becoming a critical tool in the field of art conservation. This technique provides high-resolution spatial maps of both inorganic and organic components located within cross-sectional samples collected from works of art. With recent advances in surface analysis, ToF-SIMS can now be used to identify specific amino acids present in protein-containing materials as well as fatty acids in drying oils. For example, the detection of the ion fragment associated with the amino acid hydroxyproline can be used to confirm the use of animal glue in a paint sample. As an analytical technique, ToF-SIMS avoids the need for derivatization/silylation reagents, with no interference by the presence of pigments. Furthermore, the layered systems that are often encountered in historical paint samples remain intact throughout the analytical procedure. This allows for the co-localization of organic and inorganic species in specific layers (e.g. egg yolk paint atop a glue ground). Because of this ability to localize the analytical signal to approximately 6?µm or less, the mass spectral information can be used to produce mass-resolved and spatially-resolve images which can be correlated to previous studies of the same samples. In this study, ToF-SIMS was used to analyze a paint cross section obtained from a painting attributed to Raphael, and another from a painting by the Sienese artist Matteo di Giovanni.     

The effect of limb dominance on lower limb functional performance – a systematic review

Lower limb dominance (or lateral preference) could potentially effect functional performance. Clinicians are often asked to make judgements as to when a patient has sufficiently “recovered” from an injury, typically using strength and dynamic performance outcome measures. The primary purpose of this study was to systematically review the literature in relation to limb dominance within active adult populations and discuss some limitations to current methods and relate this to current clinical practice. A search of MEDLINE and CINAHL and EMBASE databases and reference lists of those articles identified was performed. Eleven articles were selected for meta-analysis. There was no statistical effect of limb dominance for any of the functional tests: isokinetic quadriceps and hamstring tests, hamstring:quadriceps ratios, single-leg hop for distance, single-leg vertical jump and vertical ground reaction force following a single-leg vertical jump. Pooled symmetry values varied from 94.6% to 99.6% across the tests, above the clinically accepted benchmark of 90% used in clinical practice. Although the results of this study must be used with discretion, asymmetries in the tasks described in this analysis should be viewed as undesirable and remedied accordingly. Further research is needed to quantify asymmetries, particularly in relation to sport-specific contexts.     

Can textured insoles improve ankle proprioception and performance in dancers?

With the aim of determining both the acute and the chronic effects of textured insoles on the ankle discrimination and performance ability of dancers, 60 ballet dancers from the Australian Ballet School, aged 14–19 years, were divided into three groups (two intervention groups and a control group), age- and level-matched. In the first 5 weeks (weeks 1 to 5), the first intervention group (GRP1) was asked to wear textured insoles in their ballet shoes and the second intervention group (GRP2) was not given textured insoles to wear. In the next 5 weeks (weeks 6 to 10), GRP2 was asked to wear the same type of textured insoles and GRP1 did not wear the textured insoles. The control group (CTRL) did not wear textured insoles during the whole 10 weeks. All participants were tested preintervention, after 5 weeks and after 10 weeks for ankle discrimination score (AUC scores). Dance performance was assessed by 5–7 dance teachers. Pre-to-post change in AUC scores was significantly greater for the groups wearing insoles than for the controls (P = .046) and the size of pre-to-post changes did not differ between the two intervention groups (P = .834). Significant correlation was found between ankle discrimination score and performance scores, using the textured insoles (r = .412; P = .024). In conclusion, the stimulation to the proprioceptive system arising from textured insoles worn for five weeks was sufficient to improve the proprioceptive ability and performance ability of ballet dancers.     

Tipping Trouble

给小费？这在中国似乎不必。对于小费,各国有各国的讲究。在日本,如果给小费的话,会被认为是非常不礼貌的;而在美国,如果不给小费。服务员也许会追到街上问你要。     

Teacher Efficacy Research 1998–2009: Signs of Progress or Unfulfilled Promise?

This review investigates the state of teacher self- and collective efficacy research conducted from 1998 to 2009. Two hundred and eighteen empirical articles published in 1998–2009 were examined for key characteristics and compared to research published in the previous 12 years (i.e., 1986–1997). Results from the review show increases in overall teacher efficacy research, methodological diversity, domain specificity, internationalization, and focus on collective efficacy. Continuing problem areas were a lack of attention to the sources of teacher efficacy, continued measurement and conceptual problems, a lack of evidence for the links between teacher efficacy and student outcomes, and uncertain relevance of teacher efficacy research to educational practice. An outline of directions for future teacher efficacy research is provided.     

Performance Indicators and Quality Review in Australian Universities

This paper examines the relationship between sets of quantitative performance and diversity indicators and the qualitative banding of Australian universities made by the Committee for Quality Assurance in Higher Education. Using factor analysis, three performance factors (Traditional Research University Performance, Teaching Performance and Competitive Research Performance) and four diversity factors (Size, Equity, Student Staff Ratios and Access) were obtained. Strong association was found between quality ranking and composite measures of performance. When factor‐based composite measures were used, quality rankings were significantly correlated with Traditional Research University Performance, Teaching Performance and Size, and negatively with Equity.