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941.
This study used longitudinal cross-lagged modeling to examine reciprocal relations between maternal depression and child behavior problems. Data were drawn from 3,119 children (40% Hispanic, 30% African American, 20% White, and 10% other) from the Family and Child Experiences Survey of 2009 (a nationally representative sample of children served by Head Start). Results documented reciprocal relations between maternal depression and child behavior problems across early childhood (i.e., child age 3–5). Furthermore, the effect of child behavior problems on maternal depression was moderated by child race/ethnicity during children’s first year in Head Start, such that the negative effect of child behavior problems on African American mothers’ depression was more pronounced compared to Hispanics and other racial/ethnic groups.  相似文献   
942.
Single-case design (SCD) is a research methodology that may be utilized to establish the presence of a functional relation between an independent and dependent variable. Recent research has found the design to frequently be used within school psychology in the evaluation of intervention procedures. However, the overall prevalence of the design within the broader school psychology literature is unknown. As such, the purpose of the current review was to identify trends in the use of SCD within school psychology publications. Furthermore, the review sought to identify institutions and journals that most frequently published SCD. Finally, the review sought to evaluate trends in experimental rigor of published SCD. Twelve journals were examined, with all publications since their inception reviewed and classified by publication type. Results of the review indicated that SCD was the least frequently published article type. However, data indicate an increase in the prevalence and rigor of the design in recent years. Whereas some journals and institutions were found to have steady rates of SCD publications, others were found to have recent increases in the publication of the design. Implications of findings as they pertain to practitioner practice and adoption of evidence-based practice are described.  相似文献   
943.
Athlete pre-participation screening is focused on detecting pathological conditions like arrhythmogenic right ventricular cardiomyopathy (ARVC). The diagnosis of ARVC is established by applying the revised 2010 ARVC Task Force Criteria (TFC) that assesses RV structure and function. Some athletes may meet structural TFC without having ARVC but we do not know the consequences for RV function. This study compared RV structural and functional indices in male athletes that meet the structural TFC (MTFC) for ARVC and those that do not (NMTFC). We recruited 214 male elite athletes. All participants underwent 2D, Doppler, tissue Doppler and strain (ε) echocardiography with a focused and comprehensive assessment of the right heart. Athletes were grouped on RV structural data: MTFC n = 34; NMTFC n = 180. Functional data were compared between groups. By selection, MTFC had larger absolute and scaled RV outflow tract (RVOT) diameter compared to NMTFC (P ?0.05) but these athletes did not develop a proportional increase in the RV inflow dimensions. There was no difference in global conventional RV systolic function between both groups however, there was significantly lower global RV ε in athletes that MTFC which can be explained, in part, by the RVOT dimension.  相似文献   
944.
This study compared the energy expenditure (EE) levels during object projection skill performance (OPSP) as assessed by indirect calorimetry and accelerometry. Thirty-four adults (female n = 18) aged 18–30 (23.5 ± 2.5 years) performed three, 9-min sessions of kicking, over-arm throwing, and striking performed at 6-, 12-, and 30-sec intervals. EE was estimated (METS) using indirect calorimetry (COSMED K4b2) and hip-worn accelerometry (ActiGraph GT3X+). EE using indirect calorimetry demonstrated moderate-intensity physical activity (3.4 ± 0.7 METS––30-sec interval, 5.8 ± 1.2 METS––12-sec interval) to vigorous intensity physical activity (8.3 ± 1.7 METS––6-sec interval). However, accelerometry predicted EE suggested only light-intensity physical activity (1.7 ± 0.2 METS––30-sec interval, 2.2 ± 0.4 METS––12-sec interval, 2.7 ± 0.6 METS––6-sec interval). Hip-worn, ActiGraph GT3X+ accelerometers do not adequately capture physical activity intensity levels during OPSP, regardless of differences in skill performance intervals.  相似文献   
945.
Irisin is a myokine that is thought to be secreted in response to exercise that may help to prevent obesity and maintain normal glucose metabolism. In this study we investigated the associations between irisin and glucose homeostasis in middle-aged, overweight and obese men (n?= 144) with impaired glucose regulation, and the impact of exercise training on these relationships. The participants underwent 12 weeks of resistance or aerobic (Nordic walking) exercise training three times per week, 60 minutes per session. Venous blood (n?=?105) and skeletal muscle samples (n?=?45) were obtained at baseline and post-intervention. Compared to controls, Nordic walking, but not resistance training, increased irisin levels in plasma (9.6?±?4.2%, P?=?0.014; 8.7?± 4.9%, P?=?0.087; respectively) compared to controls. When considering all subjects, baseline irisin correlated positively with atherogenic index of plasma (r?=?0.244, P?=?0.013) and 2-hour insulin levels (r?=?0.214, P?=?0.028), and negatively with age (r?=??0.262, P?=?0.007), adiponectin (r?=??0.240, P?=?0.014) and McAuley index (r?=??0.259, P?=?0.008). Training-induced FNDC5 mRNA changes were negatively correlated with HbA1c (r?=??0.527, P?=?0.030) in the resistance training group and with chemerin in the Nordic walking group (r?=??0.615, P?=?0.033). In conclusion, 12-weeks of Nordic walking was more effective than resistance training in elevating plasma irisin, in middle-aged men with impaired glucose tolerance. Thus, the change in irisin in response to exercise training varied by the type of exercise but showed limited association with improvements in glucose homeostasis.  相似文献   
946.
The Lawn Tennis Association’s mini tennis (MT) is a modified version of tennis consisting of progressive stages; however, there have been few attempts to evaluate how MT might shape performance behaviours. Here, we examine effects of playing MT on the emergence of children’s match-play behaviours in 48 junior tennis players. Performance in 1010 match-play points were filmed and coded across 4 tennis stages (MT Red, MT Orange, MT Green and Full Ball), using a notational analysis system. Recorded performance variables included rally length, first serve percentage and shot type, for the purpose of analysing inter-stage comparisons. Results showed a series of specific adaptations to playing characteristics across the stages, including rally length, shot variety and serve success. MT Red rallies (7.36 ± 6.06) were longer than Full Ball rallies (3.83 ± 2.40), and a higher percentage of forehands were played at MT Red (66.40 ± 8.49%) than at Full Ball stage (45.96 ± 6.47%). Findings suggested that MT stages can afford children more opportunities to develop their skills and elicit different match-play characteristics than Full Ball task constraints. Coaches, therefore, should consider the nature of emergent adaptations when designing practice environments to facilitate learning in young tennis players.  相似文献   
947.
The development of cable force during hammer-throw turns is crucial to the throw distance. In this paper, we present a method that is capable of measuring cable force in real time and, as it does not interfere with technique, it is capable of providing immediate feedback to coaches and athletes during training. A strain gauge was mounted on the wires of three hammers to measure the tension in the wire and an elite male hammer thrower executed three throws with each hammer. The output from the gauges was recorded by a data logger positioned on the lower back of the thrower. The throws were captured by three high-speed video cameras and the three-dimensional position of the hammer's head was determined by digitizing the images manually. The five best throws were analysed. The force acting on the hammer's head was calculated from Newton's second law of motion and this was compared with the force measured via the strain gauge. Qualitatively the time dependence of the two forces was essentially the same, although the measured force showed more detail in the troughs of the force-time curves. Quantitatively the average difference between the measured and calculated forces over the five throws was 76 N, which corresponds to a difference of 3.8% for a cable force of 2000 N.  相似文献   
948.
Recent research on student learning has revealed that a number of students in any learning context are unable to distinguish between contrasting contextualised approaches to learning. In other words, the relationship between their perceptions of the learning context and their approaches to learning disintegrates and becomes incoherent. These students are observed to be among the lower academic achievers in their group. This paper reports on the results of a study which shows that physics students’ prior understandings of key concepts are systematically related to the way they approach their studies, their perceptions of the learning context and the quality of the outcomes of their studies. As with previous studies, one group reported disintegrated learning experiences. As a group they were found to have the poorest pre-conceptual knowledge, to have the poorest postconceptual knowledge, and to be the lowest achievers. These results are consistent with the earlier studies, but extend them by showing that disintegrated perceptions and approaches are related to students’ understanding before and after the subject as determined using qualitative indicators of understanding as well as assessment results.  相似文献   
949.
核电的公众接受性研究   总被引:4,自引:0,他引:4  
公众接受性对核电的发展产生过程理要影响,已引起许多核电国家的重视,本文描述了公众接受性对核电发展的影响,阐述了公众接受性的重要研究理论。  相似文献   
950.
Sixty-eight third graders who were less-skilled readers performed more poorly than younger reading-level control children on tests of pseudoword reading and phonological sensitivity. These findings add to the growing consensus that the proximal cause of reading difficulties are spelling-sound coding problems that result from deficient underlying phonological processes and structures. Analyses of their word and pseudoword reading performance provided some suggestive evidence that less-skilled readers are less sensitive than their younger reading-level matched counterparts to all subword-size orthographic units, perhaps especially to grapheme-sized units.  相似文献   
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