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1.
ABSTRACT

The length of telomeres is an objective measure of biologic ageing. This study evaluated the extent minutes of walking per week are associated with leukocyte telomere length (LTL) in a random sample of 5,823 U.S. adults. The investigation was cross-sectional and data were obtained from the National Health and Nutrition Examination Survey (NHANES). LTL was measured by the quantitative polymerase chain reaction method. Walking minutes was calculated from walking frequency and duration measures. Results showed that for each year of chronological age, telomeres were 15.6 base pairs shorter (P < 0.0001). With walking minutes and LTL treated as continuous variables, the relationship was quadratic, not linear (F = 11.2, P = 0.0023). With walking time divided into three categories, adults who performed ≥ 150 minutes of walking per week had longer telomeres than those who did no regular walking, and those who did some, but less than the recommendation (F = 5.0, P = 0.0137). Regular walkers were estimated to have a biologic ageing advantage associated with 6.5–7.6 years less biologic ageing compared to non-walkers, after adjusting for covariates. Additional investigations designed to study causality and the mechanisms associated with the walking and LTL relationship are needed.  相似文献   
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The field of educational measurement has evolved considerably since the first doctoral programs were established. In response, programs have typically tacked on courses that address newly developed theories, methods, tools, and techniques. As our review of current programs evidences, this approach produces artificial distinctions among topics and techniques that are in fact a tightly coupled whole. This position paper advocates a redesign of the scope and sequence for doctoral programs focused on the preparation of the next generations of educational measurement specialists; a redesign that reflects the full life‐cycle of instrument development and use.  相似文献   
4.
Elementary and secondary students spend more hours outside of class than in formal school and thus have more time for interaction with everyday science. However, evidence from a large international survey, Program of International Student Assessment (PISA) (OECD 2012), found a negative relationship between number of hours attending after-school science and science assessment scores in many countries, raising questions about why. The secondary analysis of the 2006, 2009, and 2012 PISA surveys found that in most Western countries the longer students attended after-school science programs (in a typical week), the lower their PISA standardized science test score, but the higher their positive attitudes toward future science careers, interest in science, and self-confidence in science. Several potential hypotheses for this relationship are examined and rejected. Further analysis of a causal relationship between frequent attendance in after-school programs and student achievement and attitudes should clearly identify the content of the program so that the analysis could distinguish experiences closely related to regular school curricula from the informal science activities that are not. A new analysis also should include carefully designed longitudinal surveys to test the effectiveness of informal experiences on later life choices in career and study.  相似文献   
5.
This study describes one teacher's use of multimedia, specifically CD-ROM talking books, in the classroom. The goal of the investigation was to reveal and analyse how a primary (Grade 3) teacher integrated CD-ROM books into her curriculum. Issues emerging from the study included how features of the software interact with features of classrooms, how patterns of instruction are affected by the infusion of technology, and how students interact with the software, and each other, while reading the CD- ROM books  相似文献   
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The purpose of the study was to investigate faculty perceptions of student evaluative information collected by three methods: objective questionnaire items, open-ended questions, and group interviews. Faculty rated three simulated evaluation reports on their potential for accuracy, trustworthiness, usefulness, comprehensiveness, believability, interpretability, and value as information used for self-improvement and promotion purposes. Faculty, in general, regarded the evaluative information to be more credible, useful, and accurate for their own self-improvement than for promotion purposes. Faculty also desired more than one type of evaluative information regardless of the purpose of evaluation.  相似文献   
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Male albino rats were run in a discrete-trial two-bar operant analog of the double alley. Completion of a FR 4 response chain on the first bar was rewarded 50% of the time for the 12 experimental Ss, but was never rewarded for the 12 control Ss. Both groups received consistent reward at the end of a FR 4 chain on the second bar. Eighty-four trials were given at a rate of four trials per day. A significantly faster rate of responding on the second bar was found following nonrewarded first-bar ratios than following rewarded first-bar ratios. This frustration effect was not attributable to response depression, since the nonrewarded performance of the experimental group exceeded that of the control group.  相似文献   
9.
This article reasserts the centrality of reasoning as the focus for moral education. Attention to moral cognition must be extended to incorporate sociogenetic processes in moral growth. Moral education is not simply growth within the moral domain, but addresses capacities of students to engage in cross-domain coordination. Development beyond adolescence in moral thinking is in two forms: (1) the gradual application of morality in broader adult contexts, and (2) the result of social discourse and progressive readjustments at the individual and societal level of views of the morality of societal practices. Postconventional moral reasoning is not a rarified stage of moral cognition, but an orientation and set of discourse skills potentially available to all normally developing adult moral reasoners.  相似文献   
10.
This article establishes a broad framework from which to interpret and evaluate the reading–science learning–writing connection. The presentation of breakthroughs, barriers, and promises is intended to outline the established links between, to identify current bottlenecks in thinking about, and to highlight productive inquiries into, print-based languages and scientific understanding. The ideas presented come from various disciplines connected to science education. The ideas are meant to be informative, provocative, integrative, supportive, and without hidden agenda.  相似文献   
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