Bilingual Mathematics

在加拿大。有人讲英语,有人讲法语,于是加拿大就将英语和法语都定为自己的官方语言。其实,加拿大不仅仅在官方语言上实施“一国两制”,在度量单位上也是公制和英制交替使用。这给加拿大人生活带来了些许不便。Brad也常为之头疼。     

Driving in China

Brad夫妇今年来中国故地重游。看到如今城市里满大街的汽车代替了20年前比比皆是的自行车,感慨之余,也对中国马路上的交通状况甚是担忧。     

The Sorrows of Being Young

编者按：年轻,固然令人羡慕,却也是个容易彷徨困惑的年纪。脚下的路似乎很长,但到底会伸向何方？又该如何去走？Brad给出了他中肯的建议。     

The biomechanical characteristics of high-performance endurance running

The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s^?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact.     

The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: A systematic review

Although the effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy have been investigated in several studies, the findings are equivocal and the practical implications remain unclear. In an attempt to provide clarity on the topic, we performed a systematic literature search of PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Physiotherapy Evidence Database (PEDro) electronic databases. Six studies were found to have met the inclusion criteria: (a) an experimental trial published in an English-language peer-reviewed journal; (b) the study compared the use of short (≤60?s) to long (>60?s) inter-set rest intervals in a traditional dynamic resistance exercise using both concentric and eccentric muscle actions, with the only difference in resistance training among groups being the inter-set rest interval duration; (c) at least one method of measuring changes in muscle mass was used in the study; (d) the study lasted for a minimum of four weeks, employed a training frequency of ≥2 resistance training days per week, and (e) used human participants without known chronic disease or injury. Current evidence indicates that both short and long inter-set rest intervals may be useful when training for achieving gains in muscle hypertrophy. Novel findings involving trained participants using measures sensitive to detect changes in muscle hypertrophy suggest a possible advantage for the use of long rest intervals to elicit hypertrophic effects. However, due to the paucity of studies with similar designs, further research is needed to provide a clear differentiation between these two approaches.     

Individual Differences in Emotional Reactivity and Academic Achievement: A Psychophysiological Study

Factors related to grade point average (GPA) are of great importance for students' success. Yet, little is known about the impact of individual differences in emotional reactivity on students' academic performance. We aimed to examine the emotional reactivity–GPA link and to assess whether self‐esteem and psychological distress moderate this relationship. Eighty undergraduate students reported on their GPA, self‐esteem, and psychological distress. Students' pupil radius was monitored during affective picture viewing to assess sympathetic activation in response to emotional stimuli. Cluster analysis on pupil reactivity to pictures identified low, average, and high emotionally reactive students. Regression analyses indicated that profiles of emotional reactivity were associated with GPA. This relationship was moderated by self‐esteem, but not psychological distress. Among students with higher emotional reactivity, those with lower self‐esteem reported poorer GPA. Findings document the importance of differences in students' emotional reactivity and self‐esteem in relation to academic success.     

Self-Regulating Informational Text Reading Comprehension: Perceptions of Low-Achieving Students

Students who struggle with learning may not have the metacognition needed to support the multiple processes required to understand what is read in informational text. Instruction for these students, therefore, should include methodologies that promote self-regulation of critical thinking processes. Fifty-eight low-achieving students were provided Self-Regulated Strategy Development instruction for the TWA (Think before reading, think While reading, think After reading) strategy approach. Students were explicitly taught to establish goals, self-monitor performance, use positive self-instructions, and self-reinforce. We examined these students' perceptions in regard to application of the self-regulation procedures. Students' worksheets and comments as well as perceptions documented in post-instruction interviews were used to gain insight into students' metacognitive awareness of the self-regulation procedures taught and learned.