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41.
The aims of this study were: (1) to identify the exercise intensity that corresponds to the maximal lactate steady state in adolescent endurance-trained runners; (2) to identify any differences between the sexes; and (3) to compare the maximal lactate steady state with commonly cited fixed blood lactate reference parameters. Sixteen boys and nine girls volunteered to participate in the study. They were first tested using a stepwise incremental treadmill protocol to establish the blood lactate profile and peak oxygen uptake ([Vdot]O2). Running speeds corresponding to fixed whole blood lactate concentrations of 2.0, 2.5 and 4.0?mmol?·?l?1 were calculated using linear interpolation. The maximal lactate steady state was determined from four separate 20-min constant-speed treadmill runs. The maximal lactate steady state was defined as the fastest running speed, to the nearest 0.5?km?·?h?1, where the change in blood lactate concentration between 10 and 20?min was?<0.5?mmol?·?l?1. Although the boys had to run faster than the girls to elicit the maximal lactate steady state (15.7 vs 14.3?km?·?h?1, P?<0.01), once the data were expressed relative to percent peak [Vdot]O2 (85 and 85%, respectively) and percent peak heart rate (92 and 94%, respectively), there were no differences between the sexes (P?>0.05). The running speed and percent peak [Vdot]O2 at the maximal lactate steady state were not different to those corresponding to the fixed blood lactate concentrations of 2.0 and 2.5?mmol?·?l?1 (P?>0.05), but were both lower than those at the 4.0?mmol?·?l?1 concentration (P?<0.05). In conclusion, the maximal lactate steady state corresponded to a similar relative exercise intensity as that reported in adult athletes. The running speed, percent peak [Vdot]O2 and percent peak heart rate at the maximal lactate steady state are approximated by the fixed blood lactate concentration of 2.5?mmol?·?l?1 measured during an incremental treadmill test in boys and girls.  相似文献   
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Working memory training improves children's cognitive performance on untrained tasks; however, little is known about the underlying neural mechanisms. This was investigated in 32 typically developing children aged 10–14 years (19 girls and 13 boys) using a randomized controlled design and multi-modal magnetic resonance imaging (Devon, UK; 2015–2016). Training improved working memory performance and increased intrinsic functional connectivity between the bilateral intraparietal sulci. Furthermore, improvements in working memory were associated with greater recruitment of the left middle frontal gyrus on a complex span task. Repeated engagement of fronto-parietal regions during training may increase their activity and functional connectivity over time, affording greater working memory performance. The plausibility of generalizable cognitive benefits from a neurobiological perspective and implications for neurodevelopmental theory are discussed.  相似文献   
44.
OBJECTIVE: Children's Advocacy Centers (CACs) aim to improve child forensic interviewing following allegations of child abuse by coordinating multiple investigations, providing child-friendly interviewing locations, and limiting redundant interviewing. This analysis presents one of the first rigorous evaluations of CACs' implementation of these methods. METHODS: This analysis is part of a quasi-experimental study, the Multi-Site Evaluation of Children's Advocacy Centers, which evaluated four CACs relative to within-state non-CAC comparison communities. Case abstractors collected data on investigation methods in 1,069 child sexual abuse cases with forensic interviews by reviewing case records from multiple agencies. RESULTS: CAC cases were more likely than comparison cases to feature police involvement in CPS cases (41% vs. 15%), multidisciplinary team (MDT) interviews (28% vs. 6%), case reviews (56% vs. 7%), joint police/child protective services (CPS) investigations (81% vs. 52%) and video/audiotaping of interviews (52% vs. 17%, all these comparisons p<.001). CACs varied in which coordination methods they used, and some comparison communities also used certain coordination methods more than the CAC with which they were paired. Eighty-five percent of CAC interviews took place in child-friendly CAC facilities, while notable proportions of comparison interviews took place at CPS offices (22%), police facilities (18%), home (16%), or school (19%). Ninety-five percent of children had no more than two forensic interviews, and CAC and comparison differences on number of interviews were mostly non-significant. CONCLUSIONS: Relative to the comparison communities, these CACs appear to have increased coordination on investigations and child forensic interviewing. The CAC setting was the location for the vast majority of CAC child interviews, while comparison communities often used settings that many consider undesirable. CACs showed no advantage on reducing the number of forensic interviews, which was consistently small across the sample.  相似文献   
45.
Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents.  相似文献   
46.
ABSTRACT

This study examined the validity of a tool that assesses tackle and ruck technique in training and established reference data for tackle, ball-carry and ruck technique at different levels of play in rugby union. One hundred and thirty-one amateur rugby union players; 37 senior, 51 first-grade academy and 43 second-grade academy players, participated in a two-on-two contact drill. The drill was filmed and the players’ tackle, ball-carry and ruck technique were assessed using standardized technical criteria. Senior level players scored significantly higher in all three assessments; tackle technique senior vs academy 1st (p < 0.01, effect size (ES) = 0.7, moderate), senior vs academy 2nd (p < 0.01, ES = 0.7, moderate); ball-carry technique senior vs academy 1st (p < 0.01, ES = 0.6, moderate), senior vs academy 2nd (p < 0.01, ES = 0.8, moderate); ruck technique senior vs academy 1st (p < 0.01, ES = 0.7, moderate), senior vs academy 2nd (p < 0.01, ES = 0.4, small). These findings emphasize the importance of developing contact technique to allow players to progress to higher levels, and provide validity to an assessment tool which can facilitate this process.  相似文献   
47.
This study examined 33 mothers' and preschoolers' oral language skills (decontextualized discourse) across an emergent reading, shared reading, and oral storytelling interaction. The sample comprised primarily African American families from various socioeconomic backgrounds, ranging from Head Start families to middle-income families. Two measures of decontextualized language were assessed—literate language features and type of talk (i.e., a coding scheme categorizing comments/questions on a continuum from contextualized to decontextualized talk). Mothers used more decontextualized language during the oral storytelling interaction versus the other interactions, but children used more during the emergent reading interaction. Mothers with advanced literacy skills were more likely to make decontextualized comments/questions and use mental/linguistic verbs during the interactions. Results are discussed in terms of implications for parent-child home literacy interventions.  相似文献   
48.
This study examines gender-based attributional ambiguity among higher education administrators in the US, specifically academic deans. Attributional ambiguity involves situations in which members of underrepresented groups cannot determine whether interactions both negative and positive have occurred because of their minority status or for some unrelated yet plausible reason. A conceptual model of attributional ambiguity in higher education administration is presented highlighting the types of situations that produce this ambiguity, two variants of attributional ambiguity (i.e. cognitive and social), and the psychological and organizational consequences of such ambiguity. Reasons that attributional ambiguity is inherent to higher education administration are examined including the fluidity of gender roles, the culture of academia, and leaders’ minimization of discriminatory experiences. Implications for professional practice are also presented such as the need for curricula, trainings, mentoring, and coaching that addresses attributional ambiguity and greater publicity related to women’s underrepresentation in leadership roles in higher education.  相似文献   
49.
The purpose of the current pilot study was to examine the effects of a teacher‐designed and teacher‐led numerical board game intervention. Fifty‐four 4‐ to 6‐year‐olds were randomly assigned to either the number board game intervention or an active control group. Relative to the control group, children who received the number game intervention demonstrated significant improvements on a numeral identification task. This finding is significant in so far as numeral identification skills play a critical role in more advanced numerical and mathematical reasoning. There was no evidence of training‐related improvements on any of the other tasks. In addition to the intervention effects, the present study provides an example of a successful teacher‐researcher collaboration, providing new insights into the making of bidirectional relations between research and practice.  相似文献   
50.
This study reports the results of extensive interviews with an intact sample of moderately delinquent adolescents concerning their sexual assault histories. Findings indicate a surprisingly high incidence of victimization among the females interviewed which, the authors suggest, may characterize the larger population of delinquent females. The behavioral-situational contexts of reported victimization experiences are examined for salient commonalities and the following composite rape scenerio can be cast from the data: An unsupervised, 14-year-old female, who has been consuming alcohol or marijuana, is sexually assaulted, following threat and/or force, to the point of penile-vaginal penetration, by an older male friend or acquaintance (who has also consumed alcohol or marijuana) in his home or vehicle or other place where she is inherently unprotected. Some comments are offered concerning the requirements of an effective technology of child rape prevention.  相似文献   
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