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1.
Contingent self-esteem (CSE) describes the degree to which self-esteem is dependent on meeting day-to-day appraisals from oneself and others. This will vary between individuals, ranging from lower to higher CSE. A lower CSE is related to a range of adaptive social and emotional outcomes in adolescents and young adults. This study explores children’s CSE and how this associates with behavioural outcomes. A total of 280 children between the ages of 9 and 11 years completed a composite questionnaire on aspects of their self-esteem and behaviour. Children’s class teachers completed behavioural outcome questionnaires for a random sample of 100 of these children. Based on teachers’ and children’s scores, high levels of global self-esteem were associated with lower CSE and fewer behavioural difficulties. CSE domains of social feedback and physical appearance retained significant associations with behavioural outcomes after controlling for global self-esteem. This may relate to the degree that children depend on the perceived evaluations of others. Implications for educational psychologists are highlighted. 相似文献
2.
目的:探讨不同负荷运动训练对大鼠骨骼肌线粒体三羧酸循环的影响及其机制。方法:将雄性Wistar大鼠50只随机均分为5组:安静对照组(C)、低负荷运动训练组(LT)、中等负荷运动训练组(MT)、高负荷运动训练组(HT)和极高负荷运动训练组(ST),每组10只。各运动组分别进行6周的跑台运动训练。训练方案结束后,取腓肠肌样本,提取线粒体,测定线粒体柠檬酸合成酶(CS)、异柠檬酸脱氢酶(ICD)和α-酮戊二酸脱氢酶(α-KGDHC)活性;线粒体Ga2+含量、胞浆NADH、NAD+、ATP和ADP含量,以及ICD mRNA转录水平。结果:(1)不同负荷运动训练组线粒体CS、ICD和α-KGDHC的活性均显著高于安静对照组(P < 0.01),且CS和ICD活性由高到低顺序均为:MT组 > HT组 > ST组 > LT组 > C组,α-KGDHC活性由高到低顺序为:HT组 > MT组 > ST组 > LT组 > C组。(2)不同负荷运动训练组线粒体Ca2+ 含量均显著高于安静对照组(P < 0.01),其含量由高到低顺序为:MT组 > HT组 > ST组 > LT组 > C组;胞浆NADH/NAD+和ATP/ADP的比值均显著低于安静对照组(P < 0.01),其比值由低到高顺序为:MT组 < ST组 < HT组 < LT组 < C组。(3)不同负荷运动训练组ICD mRNA转录水平均高于安静对照组(P < 0.01),其水平由高到低顺序为: MT组 > HT组 > ST组 > LT组 > C组。结论:低负荷、中等负荷、高负荷及极高负荷运动训练均可提高大鼠骨骼肌线粒体三羧酸循环功能,且中等负荷运动训练效果最佳。其机制与胞浆NADH/NAD+和ATP/ADP比值、线粒体摄钙能力及限速酶基因的表达有关。 相似文献
3.
George Giatsis Vassilios Panoutsakopoulos Iraklis A. Kollias 《Journal of sports sciences》2018,36(9):997-1008
The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p < .05) surface effects on the jump height, the ankle joint angle at the lowest height of the body center of mass and the ankle angular velocity. Also, significant arm swing effects were found on jump height, maximum power output, temporal parameters, range of motion and angular velocity of the hip. These findings could be attributed to the instability of the sand, which resulted in reduced peak power output due to the differences of body configuration at the lowest body position and lower limb joints’ range of motion. The combined effect of the backward arm swing and the recoil of the sand that resulted in decreased resistance at ankle plantar flexion should be controlled at the preparation of selected jumping tasks in beach-volleyball. 相似文献
4.
Matthew J. Madison 《Educational Measurement》2019,38(2):68-78
Recent advances have enabled diagnostic classification models (DCMs) to accommodate longitudinal data. These longitudinal DCMs were developed to study how examinees change, or transition, between different attribute mastery statuses over time. This study examines using longitudinal DCMs as an approach to assessing growth and serves three purposes: (1) to define and evaluate two reliability measures to be used in the application of longitudinal DCMs; (2) through simulation, demonstrate that longitudinal DCM growth estimates have increased reliability compared to longitudinal item response theory models; and (3) through an empirical analysis, illustrate the practical and interpretive benefits of longitudinal DCMs. A discussion describes how longitudinal DCMs can be used as practical and reliable psychometric models when categorical and criterion‐referenced interpretations of growth are desired. 相似文献
5.
Vietnam is an important case for studying the impact of foreign firms’ backward linkages on local firms’ productivity. As an emerging economy Vietnam became the second most popular FDI destination after China in Pacific Asia since 2014. Our empirical analysis for Vietnam as a whole demonstrates a significant difference in the productivity growth between domestic suppliers who have a direct linkage with foreign firms and non-suppliers. This is also true for the Southeast Region (SE) with Ho-Chi-Minh City as economic center. However, in the Red River Delta (RRD), that difference is not statistically significant. Based on in-depth interviews with domestic suppliers, we reveal that in the RRD, effects of foreign firms on the productivity upgrading of domestic suppliers are indirect and limited while internal factors like absorptive capacity are more important for the productivity growth. These regional differences can be traced back to different regional specializations which still persist from the pre-reform era. 相似文献
6.
随着数字化浪潮的涌现,数字经济必将对中国的经济产生更为深远的影响,表现在不仅将促进国内生产总值(GDP)更快速的增长,还将提升生产率、消费结构转型、优化投资结构、提升企业出口规模、提高人力资本质量,并引领新型智慧城市的发展。文章构建了非竞争型就业投入占用产出模型,采用支出法GDP(即最终支出的3个方面:消费、资本形成总额和出口总额)核算了我国数字经济的经济规模,最终估计3类支出所形成的经济规模分别对就业的影响效应。研究发现:(1)ICT(信息和通信技术)产业与传统产业的融合能够带动经济规模的扩张,特别是网络消费的增长,以此产生的消费导向型就业效应正在逐步扩大(使得非农就业占全部就业人数比例从2014年的15.2%增长到2016年的20.2%),其中未来应特别关注的发展领域应聚焦在医疗健康、文化娱乐和交通通讯。(2)数字经济对技术密集型制造业的就业影响强于劳动密集型和资本密集型,同时在生产型服务业中也表现出了强有力的就业影响效应,并促使我国产业经济从劳动密集型向技术密集型的转型。(3)中国的数字化转型将带来生产率的提升和创新的提速,并促进职业技能的培养,促使人力资本从低成本优势向职业技能优势转型,从而培养更高技能的劳动力队伍。 相似文献
7.
8.
目的:探究低负荷加压训练对自发性高血压大鼠的降压效果及其作用机制。方法:选取4周龄雄性自发性高血压大鼠,随机分为对照组(高血压安静组)、低负荷训练组、低负荷加压训练组和高负荷训练组。低负荷训练组进行35%~55%1RM递进式低负荷爬梯训练,低负荷加压训练组进行30%~40%血流受限结合35%~55%1RM递进式低负荷爬梯训练,高负荷训练组进行55%~75%1RM递进式高负荷爬梯训练,训练后测定血压、血液中内皮素-1、血管内皮生长因子、一氧化氮合成酶的表达和心肌组织中内皮型一氧化氮合成酶的表达。结果:1)与对照组、高负荷训练组相比,低负荷加压训练组收缩压、舒张压显著下降(P<0.05);与低负荷训练组相比,低负荷加压训练组舒张压显著下降(P<0.05)。2)与对照组相比,低负荷加压训练组血液中内皮素-1表达显著下调(P<0.05),血管内皮生长因子和一氧化氮合成酶表达显著上调(P<0.05);3)与对照组相比,低负荷加压训练组心肌中内皮型一氧化氮合成酶表达显著上调(P<0.05);4)在低负荷加压训练组中,收缩压与内皮素-1呈正相关,相关性分析具有统计学意义(P<0.05);收缩压与一氧化氮合成酶、血管内皮生长因子、内皮型一氧化氮合成酶均呈负相关,相关性分析具有统计学意义(P<0.05)。结论:1)低负荷加压训练降压效果优于高负荷训练;2)低负荷加压训练能够通过下调血液中内皮素-1的表达,上调血液中血管内皮生长因子和一氧化氮合成酶的表达,同时上调心肌中内皮型一氧化氮合成酶表达,改善内皮细胞功能,达到降压的效果。 相似文献
9.
Alessandro Moura Zagatto Paulo Eduardo Redkva Rodrigo Araújo Bonetti de Poli Joel Abraham Martinez González Jeniffer Zanetti Brandani Thiago Penedo 《European Journal of Sport Science》2019,19(5):645-652
The purpose of this study was to investigate the use of a single 3-min all-out maximal effort to estimate anaerobic capacity (AC) through the lactate and excess post-exercise oxygen consumption (EPOC) response methods (AC[La?]+EPOCfast) on a cycle ergometer. Eleven physically active men (age?=?28.1?±?4.0?yrs, height?=?175.1?±?4.2?cm, body mass?=?74.8?±?11.9?kg and ?O2max?=?40.7?±?7.3?mL?kg?1?min?1), participated in the study and performed: i) five submaximal efforts, ii) a supramaximal effort at 115% of intensity of ?O2max, and iii) a 3-min all-out maximal effort. Anaerobic capacity was estimated using the supramaximal effort through conventional maximal accumulated oxygen deficit (MAOD) and also through the sum of oxygen equivalents from the glycolytic (fast component of excess post-exercise oxygen consumption) and phosphagen pathways (blood lactate accumulation) (AC[La?]+EPOCfast), while during the 3-min all-out maximal effort the anaerobic capacity was estimated using the AC[La?]+EPOCfast procedure. There were no significant differences between the three methods (p?>?0.05). Additionally, the anaerobic capacity estimated during the 3-min all-out effort was significantly correlated with the MAOD (r?=?0.74; p?=?0.009) and AC[La?]+EPOCfast methods (r?=?0.65; p?=?0.029). Therefore, it is possible to conclude that the 3-min all-out effort is valid to estimate anaerobic capacity in physically active men during a single cycle ergometer effort. 相似文献
10.
Jack E. T. Wells Andrew C. S. Mitchell Laura H. Charalambous Iain M. Fletcher 《Journal of sports sciences》2018,36(16):1847-1851
Whilst previous research has highlighted significant relationships between golfers’ clubhead velocity (CHV) and their vertical jump height and maximum strength, these field-based protocols were unable to measure the actual vertical ground reaction force (vGRF) variables that may correlate to performance. The aim of this study was to investigate relationships between isometric mid-thigh pull (IMTP), countermovement jump (CMJ), squat jump (SJ) and drop jump (DJ) vGRF variables and CHV in highly skilled golfers. Twenty-seven male category 1 golfers performed IMTP, CMJ, SJ and DJ on a dual force platform. The vertical jumps were used to measure positive impulse during different stretch-shortening cycle velocities, with the IMTP assessing peak force (PF) and rate of force development (RFD). Clubhead velocity was measured using a TrackMan launch monitor at a golf driving range. Pearsons correlation coefficient analyses revealed significant relationships between peak CHV and CMJ positive impulse (r = 0.788, p < 0.001), SJ positive impulse (r = 0.692; p < 0.001), DJ positive impulse (r = 0.561, p < 0.01), PF (r = 0.482, p < 0.01), RFD from 0–150 ms (r = 0.343, p < 0.05) and RFD from 0–200 ms (r = 0.398, p < 0.05). The findings from this investigation indicate strong relationships between vertical ground reaction force variables and clubhead velocity. 相似文献