促进农业基础研究保障我国粮食安全——973计划对我国粮食安全的贡献及其发展建议

近年来,国际粮食储备量持续下降而产生了世界粮食危机,我国的粮食安全问题也逐步引起政府和国民的重视.本文分析了我国粮食产量的发展趋势,提出了影响粮食单产的基础科学问题,并从优良品种培育、高产栽培、植物保护和农田土壤方面总结了973计划所取得的成就,进一步提出农业重大基础研究保障粮食安全的发展建议.     

女大学生功利型婚恋观透视

女大学生中的少数人在对待自己的爱情婚姻问题上,从＂唯爱论＂向＂唯钱论＂转身。其内在原因是依附心理、攀比心理和众从心理,外在的社会文化原因是市场经济的物化作用、女性就业的特殊压力。功利型婚恋观体现了部分女大学生追求幸福生活的尝试,也反映了她们在婚恋观上的迷茫。应通过加强学校的教育、父母家庭的积极影响等加以引导。     

乡镇土地资源生态安全评价及区划研究

土地资源是人类生存与发展最基本的资源环境基础。人口增长、工业化以及城市化的快速发展严重地威胁着土地的生态安全状况。土地生态安全的评价及区划研究,能深度剖析土地资源开发利用的状况,为我国各级政府部门进行土地利用规划编制提供科学依据。已有土地生态安全评价及其区划研究主要侧重于国家级、省级、市级、县级这4个层面。乡镇土地生态安全评价及区划方面的研究较少。本文借鉴已有研究成果,首先阐述了土地生态安全的概念,然后构建了一整套适合于乡镇进行土地生态安全评价及区划的技术方法体系,最后选择云南省禄劝县作为案例进行评价和区划。     

当前大学体育公共课教学质量评估方案初探

采用文献资料法、问卷调查法、专家访谈法、实验法等方法对当前大学体育公共课教学质量评估方案进行了初步探讨。在统计出专家调查问卷结果的基础上,结合模糊数学的原理和统计学方法确定了较为全面、客观的评估指标,初步制定出主、客观评价相结合、二级与三级评判相结合的综合性评估方案,对当前大学体育公共课教学质量的提高具有一定的指导意义。     

Dynamical analysis of winter terrain park jumps

Jump features in winter terrain parks frequently pose a hazard to patrons and may represent a significant liability risk to winter resorts. By performing a simple dynamic analysis of terrain park jumps, the relative risk to impact injuries for any proposed jump design can be quantified thereby allowing terrain park designers to minimize the risk from this class of injury.     

“阳光体育运动”实施与普通高校体育新课程创新教学模式构建

青少年的体质健康水平是我们整个民族健康素质的根基。全国亿万学生"阳光体育运动"的实施,是新时期加强青少年体育,增强青少年体质健康的战略举措,是各级学校贯彻党的教育方针,认真落实"健康第一"的指导思想和形成"终身体育"行为习惯的具体体现。普通高校体育新课程教学应随着"阳光体育运动"的实施注入新的模式,以满足不同层次学生身体和精神的高品质的生活需求,更有效地促进大学生体质健康水平的提高。     

浅析武术运动的社会价值及其在全民健身运动中的作用

文章运用文献资料研究方法,对武术运动的社会价值进行了分析,并对其在全民健身运动中的作用进行了简要的论述,指出了加强武术运动快速发展的必要性和可能性及其与全民健身运动相结合的现实意义。     

Experiences of teacher evaluation systems on high school physical education programs

Primary objective: Teacher evaluation is being revamped by policy-makers. The marginalized status of physical education has protected this subject area from reform for many decades, but in our current era of system-wide, data-based decision-making, physical education is no longer immune. Standardized and local testing, together with structured observation measures, are swiftly being mandated in the USA as required elements of teacher evaluation systems in an effort to improve school programs and student achievement. The purpose of this investigation was to document how this reform was initiated and the experiences of teachers, students and administrators, from three high school physical education programs, during initiation of this reform. Documenting how physical education programs respond to such reforms develops our understanding of top-down reform efforts and helps to identify conditions under which such reforms have the intended effect on physical education teachers and student learning in physical education.

Theoretical framework: Fullan’s three phases of school change has been used to analyze and guide school change efforts in several subject areas including physical education. The phases are initiation, implementation and institutionalization. This study is situated primarily within the first phase of school change, the initiation phase.

Methods and procedures: This study took place over a 21-month period in 3 suburban school districts in a northeast metropolitan area of the USA. Interviews with district physical education administrators, high school physical education teachers and students were conducted. Field notes of physical education classes, informal interviews and related artifacts including pre- and post-physical education assessments were collected. To ensure trustworthiness, several steps were taken including member checks, triangulation and peer review. The data were analyzed to find common themes and patterns using the constant comparative method.

Results: Several themes emerged: (1) changes in curriculum and assessment; (2) effect on administrators; (3) stakeholder apathy and (4) department collaboration.

Conclusion: Changes, although minor, did take place in the wake of this top-down teacher reform; however, additional research needs to be completed to determine whether or not these changes are meaningful or long lasting.     

Effectiveness of physical education to promote motor competence in primary school children

Background: Motor skill (MS) competence is an important contributing factor for healthy development.

Purpose: The goal was to test the effectiveness of primary school physical education (PE) on MS and physical fitness (PF) development.

Methods: Three classes (n?=?60, aged 9.0?±?0.9) were randomly assigned to three diverse conditions during a school year: two PE lessons/week (PE-2), three PE lessons/week (PE-3), and no PE lessons control group (CG). BMI, skinfolds, PF (9-min run/walk, sit-up, modified pull-ups), gymnastics, soccer, handball, basketball and track-and-field skills were evaluated. Effect sizes (d) were reported as magnitude of change.

Results: Skinfolds significantly increased only in CG (d?=?1.21). PF composite z-scores improved in PE-3 (d?=?0.61), but decreased in PE-2 (d?=?0.57), and had no changes in CG. Statistically significant improvement was verified in gymnastics and handball skills in both experimental groups (gymnastic: d?=?2.95 and d?=?2.61 for PE-3 and PE-2, respectively; handball: d?=?1.87 and d?=?0.57 for PE-3 and PE-2, respectively), and no changes were seen in CG. In soccer, there were improvements only in the PE-3 (d?=?0.55), and in basketball only in PE-2 (d?=?0.46). There were no changes in any group for track-and-field skills.

Conclusions: PE programs can effectively promote PF and MS development.     

A prospective examination of the impact of high levels of exercise training on sedentary behaviour

The aim of this study is to determine changes in sedentary behaviour in response to extensive aerobic exercise training. Participants included adults who self-selected to run a marathon. Sedentary behaviour, total activity counts and physical activity (PA) intensity were assessed (Actigraph GT3X) for seven consecutive days during seven assessment periods (?3, ?2, and ?1 month prior to the marathon, within 2 weeks of the marathon, and +1, +2, and +3 months after the marathon). Models were fitted with multiple imputation data using the STATA mi module. Random intercept generalized least squares (GLS) regression models were used to determine change in sedentary behaviour with seven waves of repeated measures. Results: Twenty-three individuals (mean?±?S_x: 34.4?±?2.1y, 23.0?±?1.9% fat, 15 women, 8 men) completed the study. Marathon finishing times ranged from 185 to 344 minutes (253.2?±?9.6 minutes). Total counts in the vertical axis were 1,729,414 lower one month after the race, compared with two months prior to the race (peak training). Furthermore, counts per minute decreased by 252.7 counts·minute^?1 during that same time period. Daily sedentary behaviour did not change over the seven assessment periods, after accounting for age, gender, per cent body fat, wear time, marathon finishing time, and previous marathon experience. This prospective study supports the notion that PA and sedentary behaviours are distinct, showing that sedentary behaviour was not impacted by high levels of aerobic training.