Effect of computer interfaces on chemistry problem solving among various ethnic groups: A comparison of Pen-Point and Powerbook computers

This study investigated the effect of Pen-Point and Powerbook computers on solving a multiple step chemistry (molaritý) problem among White, Afro-American and Hispanic students (N=60) at the high school level. The screens on both computers were partitioned into a work field and a reasoning field. Both computers were programmed to record the time spent in each field, the number of entries made, and a copy of the entries made. Statistical analysis of data showed that more of the White and Afro-American Pen-Point computer users solved the problem correctly than did students using the Powerbook computer. All three ethnic groups made fewer entries, and took less time using the Pen-Point computer than the Powerbook. Attitude survey results of all ethnic groups showed that more Pen-Point computer users felt comfortable working with computers. Over all, the results suggest that the Pen-Point computer has a more positive effect on the problem solving performance and attitude of students towards computers than the Powerbook computer.     

柔韧素质的重要性及训练要点

学生喜欢体育锻炼,但往往忽视基础素质训练。人的柔韧素质对掌握体育技能至关重要。没有柔韧性,不可能顺利准确地完成运动项目所要求的动作。所以应大力加强柔韧素质训练,训练时要注意循序渐进、强度适中、动静结合、整体训练等几个方面。     

耐力和抗阻运动对血脂代谢的影响

长期规律的体育运动均可有效地改善其不良的脂质结构,并能延缓因增龄而带来的不良影响,从而使冠心病的危险性显著降低。目前WHO已将体育运动过少列为冠心病的独立危险因素。因为运动训练对血脂水平的改善起到了至关重要的作用。本综述旨在阐明耐力运动和抗阻运动对血脂代谢的影响。     

浅谈免棱镜全站仪在工程测量中的应用

介绍了免棱镜全站仪的工作原理及优缺点,对Leica TS06全站仪在无反射棱镜条件下的测距性能进行了测试,得出了测距边长、测量目标的属性对免棱镜测距的影响关系,介绍了免棱镜全站仪在工程项目测量中的应用实例。     

The Reliability of Distance Run Tests for Children in Grades K—4

Abstract

The purpose of this study was to determine test–retest reliability for the 1-mile, 3/4-mile, and 1/2-mile distance run/walk tests for children in Grades K—4. Fifty-one intact physical education classes were randomly assigned to one of the three distance run conditions. A total of 1,229 (621 boys, 608 girls) complied the test–retests in the fall (October), with 1,050 of these students (543 boys, 507 girls) repeating the tests in the spring (May). Results indicated that the 1-mile run/walk distance, as recommended for young children in most national test batteries, has acceptable intraclass reliability (.83 < R < .90) for both boys and girls in Grades 3 and 4, has minimal (fall) to acceptable (spring) reliability for Grade 2 students (.70 < R < .83), but is not reliable for children in Grades K and 1 (.34 < R < .56). The 1/2 mile was the only distance meeting minimal reliability standards for boys and girls in Grades K and 1 (.73 < R < .82). Results also indicated that reliability estimates remained fairly stable across gender and age groups from the fall to spring testing periods, with the exception of the noticeably improved values for Grade 2 students on the 1-mile run/walk test. Criterion-referenced reliability (P, percent agreement) was also estimated relative to Physical Best and Fitnessgram run/walk standards. Reliability coefficients for all age group standards were acceptable to high (.70 < P < .95), except for Fitnessgram standards for 5-year-old girls on the 1-mile test for both fall and spring and for 6-year-old boys and girls on the 1-mile test administered in the spring.     

Influence of regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and running performance

Abstract

This study investigated the influence of the regression model and initial intensity during an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and performance in elite-standard runners. Twenty-three well-trained runners completed a discontinuous incremental running test on a treadmill. Speed started at 9 km · h^?1 and increased by 1.5 km · h^?1 every 4 min until exhaustion, with a minute of recovery for blood collection. Lactate–speed data were fitted by exponential and polynomial models. The lactate threshold was determined for both models, using all the co-ordinates, excluding the first and excluding the first and second points. The exponential lactate threshold was greater than the polynomial equivalent in any co-ordinate condition (P < 0.001). For both models, the lactate threshold was lower when all co-ordinates were used than when the first and the first and second points were excluded (P < 0.001). 10-km race pace was correlated with both the exponential and polynomial lactate thresholds for all the co-ordinate conditions (r ≥ 0.75, P < 0.001 and r ≥ 0.56, P < 0.05, respectively). The results suggest that the exponential lactate threshold should be used instead of the polynomial equivalent since it is more strongly associated with performance and is independent of the initial intensity of the test.     

Response of brain-derived neurotrophic factor to combining cognitive and physical exercise

Purpose: Brain-derived neurotrophic factor (BDNF) is well known for its potential to promote brain plasticity. It has been proposed that combining cognitive and physical exercise (CCPE) may have the potential to generate more synergistic benefits in cognitive function than either cognitive exercise (CE) or physical exercise (PE) alone. The purpose of this study was to examine acute responses of peripheral BDNF levels and cognitive performance to CE, PE, and CCPE.

Methods: Thirteen healthy adult men participated in four experimental sessions; a 30-min CE, a 30-min cycling PE at an intensity of 60% peak oxygen uptake, a 30-min CCPE at the same intensity as PE, and a 30-min session of complete rest. Plasma BDNF levels and cognitive performance were measured before and after each session.

Results: Both PE and CCPE significantly increased plasma BDNF levels (p?p?≥?.05), and there was no significant difference in peripheral BDNF levels between PE and CCPE (p?≥?.05). No session induced a significant change in cognitive performance (p?≥?.05).

Conclusions: Our study suggests that CE and PE have different responses of peripheral BDNF levels and that CCPE had no additional or synergistic effect on peripheral BDNF levels compared with PE alone. This study offers further insights into the potential mechanisms underlying the respective roles of CE, PE, and CCPE for peripheral BDNF levels and cognitive performance.     

Funding,reputation and targets: the discursive logics of high-stakes testing

This paper provides insights into teacher and school-based administrators’ responses to policy demands for improved outcomes on high-stakes, standardised literacy and numeracy tests in Australia. Specifically, the research reveals the effects of the National Assessment Program – Literacy and Numeracy (NAPLAN), and associated policies, in the state of Queensland. Drawing suggestively across Michel Foucault’s notions of disciplinary power and subjectivity, and Pierre Bourdieu’s concept of social fields, the research utilises interviews with teachers and school-based administrators to reveal how high-stakes, standardised testing practices served to discursively constitute performative teacher subjectivities around issues of funding, teacher and school reputation and target-setting within what is described as the ‘field of schooling practices’. The paper argues that the contestation evident within this field is also reflective and constitutive of more educative schooling discourses and practices, even as performative logics dominate.     

长株潭城市群知识产权发展现状研究

通过网络和文献调查及实地调研,收集长株潭城市群1998年-2007年十年间的知识产权投入、知识产权成果、知识产权运用以及知识产权保护和管理四个方面的指标数据,对长株潭城市群的知识产权发展现状进行分析,大量的系统统计数据表明,需要从发展知识产权文化、实施知识产权战略等几方面努力保护知识产权。     

对应用型本科院校俱乐部制体育教学“教考分离”的思考

分析了应用型本科院校俱乐部制体育教学实施"教考分离"的利弊,提出了应用型本科院校俱乐部制下体育教学"教考分离"的实施条件和具体实施建议。