自行车——最环保的交通工具(英文)

人类历史发展至今,已经脱离了刀耕火种的原始生存状态,步入了一段前所未有的文明时期。人类利用日渐发达的聪明才智,制造出汽车、飞机等交通工具,并登上了月球,在火星和深遂的海洋中安排机器人进行勘测……然而,随着这种文明的发展,也出现了很多环境问题。既然历史的车轮无法让我们再回到从前简单的生活方式当中,就只有认识且反省人类曾经对环境犯下的错误,并在将来的日子里竭力纠正——无论这是一项多么艰巨的任务。     

Making Friends with Foreigners on the Internet

交个外国网友到底靠不靠谱？友谊在他们心中又占多大份量？这些问题一直在困扰着Rose。身为加拿大人的Brad会给她什么样的建议？     

Kid's stuff: the nature and impact of peer and sibling violence on younger and older children

OBJECTIVE: It is widely presumed that when children are hit by peers or siblings, it is not as serious as similar acts between adults or older youth, which would be termed, "assaults" and "violent crimes". The goal of this study was to compare the violent peer and sibling episodes of younger children to those of older youth in terms of their seriousness and association with symptoms that might indicate traumatic effects. METHOD: The study collected reports of past year's violent victimizations and childhood symptoms in a national probability telephone sample of 2030 children and youth ages 2-17. The experiences of 10-17-year olds were obtained via self-reports and those of the 2-9-year olds from caregivers. RESULTS: The younger children's peer and sibling victimizations were not less serious than the older youth on the dimensions of injury, being hit with an object that could cause injury or being victimized on multiple occasions. Younger children and older youth also had similar trauma symptom levels associated with both peer and sibling victimization. CONCLUSION: There was no basis in this study for presuming peer and sibling victimizations to be more benign when they involve younger children. The findings provide justification for being concerned about such peer and sibling violence in schools and families and for counting such victimizations in victimization inventories and clinical assessments.     

Specific language impairment, theory of mind, and visual perspective taking: evidence for simulation theory and the developmental role of language

Recent research has found that the acquisition of theory of mind (ToM) is delayed in children with specific language impairment (SLI). The present study used a battery of ToM and visual perspective taking (VPT) tasks to investigate whether the delayed acquisition of ToM in children with SLI is associated with delayed VPT development. Harris' (1992, 1996) simulation theory predicts that the development of VPT will be delayed. Participants were 20 children with SLI (M=62.9 months) and 20 typically developing children (M=61.2 months) who were matched for nonverbal ability, gender, and age. The results supported Harris' theory and a role for language in ToM and VPT development.     

Re-conceptualizing Emotion and Motivation to Learn in Classroom Contexts

To better inform and improve classroom teaching and learning, now more than ever before, educational researchers need to effectively and efficiently describe essential components of positive learning environments. In this article, we discuss how our research findings about motivation in classrooms have led to a closer examination of emotions. We describe how motivation theories such as Academic Risk Taking, Flow Theory, and Goal Theory have helped us better understand emotions in our classroom research. Our findings suggest that engaging students in learning requires consistently positive emotional experiences, which contribute to a classroom climate that forms the foundation for teacher–student relationships and interactions necessary for motivation to learn. We conclude that we need to integrate emotion, motivation, and cognition theoretically and methodologically to move our research forward. New theories and methods, even new forms of intellectual discourse, are required. Therefore, we end this article by beginning a discussion of new directions for conceptualizing and researching classrooms in ways that will involve examining the emotions of students and teachers.

Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.     

Are assessment environments gendered? An analysis of the learning responses of male and female students to different assessment environments

There is considerable variation between male and female Bachelor degree performance at Oxford and Cambridge (Oxbridge) where male students attain more First and Third Class degrees and female students attain more Second Class degrees. Various hypotheses have been put forward to explain this phenomenon including the possibility that the distinctive Oxbridge assessment environment, very different from those at both pre‐ and post‐92 universities, might account for the difference. Data from the Assessment Experience Questionnaire (AEQ; Oxbridge, pre‐ and post‐92 universities, one science, one humanities and one applied social science subject from each) were analysed to determine gendered perceptions of the assessment environment. Significant gender differences were found on five AEQ scales (Quantity of effort, Coverage of syllabus, Quantity and quality of feedback, Use of feedback and Appropriate assessment) but there was no significant interaction between gender and university. Consequently, there were few clues in students' responses to confirm that the Oxbridge assessment environment explains gendered differences in degree performance.     

Comparison of efficiency measures for academic interventions based on acquisition and maintenance

Previous research has demonstrated the importance of examining the instructional efficiency of academic interventions and has defined efficiency as the number of items learned per instructional minute. Maintenance of the skill is also an important instructional goal, however. Therefore, the current study compared efficiency metrics using initial learning and maintenance with 25 fourth‐grade students. Each student was taught the pronunciation and English translation of 12 words from the Esperanto international language with two instructional conditions (six words for each condition). The first condition was traditional drill (TD) rehearsal with all unknown words, and the second was incremental rehearsal (IR) with one unknown and eight known words. Results indicated that, although the IR condition led to significantly more words being retained, TD was significantly more efficient using initial learning. The two conditions were equally efficient, however, when maintenance data were used. Therefore, evaluating the efficiency of instructional interventions should consider maintenance data as well. © 2009 Wiley Periodicals, Inc.