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71.
72.
Identifying social learning in wild populations is complicated by the relative lack of ability to conduct controlled experiments in natural habitats. Even in more controlled captive settings, tracking the innovation and spread of behavior among known individuals can be challenging, and these studies often suffer from a lack of ecological validity. In recent years, a host of new approaches have been undertaken to attempt to provide more quantitative control and empirical demonstration of social learning, both in the wild and in captive settings that more closely mimic natural contexts. Developmental approaches are being undertaken more regularly that allow us to study the ontogenetic trajectory of complex skills in a variety of taxa. Likewise, a spirited focus on the social context of social learning has emerged, and researchers have begun to meticulously analyze the influences of social systems and the characteristics of demonstrators and observers. Here, we provide a review of these studies and summarize the opportunities and constraints that exist when one attempts to study learning in social species. We suggest that although the study of social learning in nonhuman animals is becoming much more complex, addressing this complexity provides a fruitful model for understanding the evolution of human cultural behavior.  相似文献   
73.
During competition, kayak athletes must optimally adapt to environmental factors (e.g. wind, waves) to achieve peak performance. However, the ability to adapt to such perturbations has never been assessed in kayak paddling. Therefore, the aim of the current study was to evaluate the local dynamic stability in sports technique of youth sprint kayak athletes. In a cross-sectional study, 14 healthy male athletes were recruited from an elite youth sprint kayak squad. During an incremental kayak ergometer test, mean power, heart rates and local dynamic technique stability of hands, arms, trunk and paddle were registered and the association with the athletes 2000?m free-water times were estimated using mixed models. The 2000?m free-water performance significantly predicted the paddles (p?=?.037) local dynamic stability whereas no association was found for the trunk or the upper extremity kinematics. In conclusion, kayak athletes with high-performance capability over 2000?m paddling depict high local dynamic technique stability. This emphasizes the importance of a stable technique for advanced kayak skills, especially regarding paddling movements.  相似文献   
74.
Purpose: To evaluate the influence of physical maturity on the changes in ventricular morphology and function with sport training in female youth athletes.

Methods: Thirty-two female athletes (age 13–18 years) underwent height and weight measurement and 2-D echocardiographic evaluation immediately prior to, and following, a 20-week soccer season. Pre- and post-season left ventricular end-diastolic diameter (LVEDD), end-diastolic volume (LVEDV), ejection fraction (LVEF), stroke volume (LVSV), mass (LVM), and posterior wall thickness (LVPWT), right ventricular end-diastolic diameter (RVEDD), end-diastolic area (RVEDA), and fractional area change (RVFAC), and interventricular septal thickness (IVST) were compared. In-season change in each variable was compared across pre-season hours of vigorous physical activity (0–1, 2–3, >3 hours).

Results: Significant increases were identified in LVEDV (51.3?±?10.4?v 56.4?±?9.6?ml/m2, p?=?0.001) and RVEDA (10.5?±?1.9?v 11.3?±?2.5?cm2/m2, p?=?0.040), but not LVEDD, LVM, LVPWT, LVSV, RVEDD, RVEDA, RVFAC, or IVST (p?>?0.05 for all). In-season changes in echocardiographic variables did not differ across hours of pre-season vigorous physical activity (p?>?0.05 for all).

Conclusion: Among female adolescent soccer players, in-season training elicits changes in resting ventricular volume, but not wall thickness or systolic function. These adaptations do not appear to be influenced by pre-season physical activity level.  相似文献   
75.
Two studies investigated whether parent–child discussion of peer provocations reduces young children's hostile attributional bias. Study 1 (= 109, age 4–7)—an observational study—showed that parent–child discussion of nonhostile attributions (when reading a picture book) predicted reductions in children's hostile attributional bias from pre‐ to postdiscussion. Study 2 (= 160, age 4–6)—an experimental study—showed that stimulating parents to discuss either nonhostile attributions or normative beliefs (vs. a control condition) reduced children's hostile attributional bias in response to hypothetical vignettes, but not in response to a staged peer provocation. These findings suggest that by framing social situations, parents may help their children perceive less hostility in their social worlds.  相似文献   
76.
Misconceptions about adaptation by natural selection are widespread among adults and likely stem, in part, from cognitive biases and intuitive theories observable in early childhood. Current educational guidelines that recommend delaying comprehensive instruction on the topic of adaptation until adolescence, therefore, raise concerns because children's scientifically inaccurate theories about species may be left unchallenged for many years, allowing them to entrench and become difficult to overcome. In consequence, this investigation sought to explore whether classrooms of kindergartners and second graders could acquire a basic but comprehensive understanding of adaptation from an intervention constructed around two picture storybooks that mechanistically explain natural selection. Learning was assessed in near and far transfer contexts both immediately and a month later. Kindergartners and second graders demonstrated substantial learning of biological information; however, second graders showed pronounced abilities to near and far generalize, immediately and over time. Results suggest that causally cohesive interventions with an emphasis on mechanistic explanation facilitate children's classroom learning of complex counterintuitive scientific ideas.  相似文献   
77.
The purpose of this study was to examine protective factors as predictors of suicide risk among graduate students (n = 413) at a large midwestern university. Using binary logistic regression, the authors assigned students to risk classifications (i.e., nonrisk group or suicide risk group). Results indicated emotional stability as the strongest predictor for participants’ placement into the nonrisk or suicide risk group. The authors discuss implications for counselors and directors of college counseling centers, as well as directions for future research.  相似文献   
78.
79.
Abstract

The purpose of this study was to examine the relationship between motor proficiency and body mass index (BMI) in preschool children. Thirty-eight children ages 4–6 years had their BMI calculated and were assessed using the Movement Assessment Battery for Children-2 (MABC-2; Henderson, Sugden, & Barnett, 2007). These data were analyzed in two ways. The correlation between BMI and MABC-2 percentile ranks was calculated. Next, the groups were subdivided based on BMI status (high, M = 85.5; medium, M = 49.8; low, M = 10.8), and compared using t tests to determine if differences existed in MABC-2 percentile ranks. No significant relationship existed between MABC-2 and BMI percentile ranks (r = -.237). However, significant differences in MABC-2 percentile ranks existed between high and low (p = .042), and high and medium (p = .043) groups. These results suggest that preschool children classified as overweight or obese may have lower motor proficiency than their normal weight and under weight peers. This study indicates there is a direct relationship between motor proficiency and BMI in the preschool population.  相似文献   
80.
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