没有相应问题的回答——阿尔都塞文本解读方法透析

阿尔都塞的症候阅读法最为关注的是那些在文本中出现的“没有相应问题的回答”,这是对恩格斯在《资本论》第二版序言中的某些思想的承接。正是运用这种方法,他不仅从马克思那里读出了不同于古典经济学的总问题,而且还读出了他自己的“理论实践”和马克思寄予后人的殷切期望。这一方法不仅启示我们去直面经典作家的文本,而且还给后人解读文本提供了三个不同视角。     

市场经济条件下自学考试社会助学发展的思考

运用价值规律相关理论,从市场经济角度对高等教育自学考试社会助学做出考察,探讨了自学考试管理机构利用市场规律对社会助学进行调控的基本手段和方法.这对高等教育自学考试机构加强社会助学管理具有一定的理论指导意义.     

“2012年第59届美国运动医学会年会”专栏——体力活动研究的现状及趋势

体力活动研究近年来受到越来越多的关注。以2012年第59届美国运动医学会年会交流论文为例,从体力活动与健康、体力活动现状调查、体力活动测量工具、体力活动影响因素、体力活动促进五个方面对当前体力活动研究的现状进行总结。结果表明第59届美国运动医学会年会发表的体力活动相关研究具有选题范围广、研究深入细致、实践应用价值大等特点。建议在我国进行体力活动研究时采用客观准确的方法测量体力活动水平与健康指标,明确两者间的量效关系,从而提出适合国人的体力活动指南;在体力活动的流行病学调查中,尽量应用客观测量工具,并采用追踪研究的设计,从而准确评估国人体力活动水平及其变化趋势;从多个层面深入研究不同人群的体力活动影响因素,为体力活动干预方案的设计提供切实依据;体力活动干预方案的设计要依据成熟的理论和可靠的证据,同时兼顾方案的效果和实施的成本效益。     

体力活动：ADHD儿童认知功能改善的干预选择

注意缺陷与多动症(ADHD)是儿童常见的行为障碍,患儿通常伴有自我调节障碍与学业困难,其生活品质与社会功能的发展受到极大的消极影响。体力活动对儿童的认知功能有积极影响,可以作为ADHD的干预策略予以应用。ADHD儿童的运动参与干预理论模型及相应的预防机制亟需探索与发展。     

Position statement: Testing physical condition in a population – how good are the methods?

Abstract

A poor physical condition – expressed as physical inactivity and poor physical fitness – is associated with the development of chronic diseases and premature death. Our aim was to evaluate the methods currently available for measuring physical activity and physical fitness in the general population.

Physical activity is determined by duration, frequency, and intensity and derives from many different domains, making it difficult to assess over long periods and no feasible general criterion measure exists. Both objective and subjective methods are available. Of the objective methods, accelerometry is the most attractive technology, and is well enough developed for general use in large populations. The advantage of accelerometry is that it is not dependent on the memory of the individual, but its main disadvantage is that it grossly underestimates energy expenditure, due to the lack of registration of certain activities. This may be overcome to a certain extent by combining accelerometry with heart rate monitoring, although this still does not measure activity in different domains. Of the subjective methods, self-report questionnaires are inexpensive and easy to administer. Many questionnaires have been developed, but we require (1) consensus on which measures to use for validation and (2) further development of internationally standardized questionnaires for use in different settings and to address different scientific questions. Many questionnaires correlate well with biological markers and development of chronic diseases, but subjective measurement will always entail a certain degree of misclassification. Furthermore, unstructured physical activity such as housework and gardening may be subject to recall bias. No method appears better to any other, and the choice of instrument will depend on the research question being asked. Future research should combine information from both objective and subjective methods.

Physical fitness comprises several components, including cardiorespiratory endurance and muscle strength and endurance. Direct measurement of oxygen consumption is the criterion measure for cardiorespiratory endurance. As regards muscle strength and endurance, only test–retest reliability is available. Hand-held dynamometers greatly facilitate field testing for maximal isometric muscle strength assessment, while force plate measurements can be used for the lower extremities. For endurance, simple tests such as push-ups and sit-ups are reliable.     

Social influence in relation to current and intended physical activity among adolescents

Abstract

The aim of the present study was to examine the impact of social support and negative social influence from various contexts on adolescents’ current and intended physical activity. Questionnaire data were obtained from 1156 students aged 16–17 years. Relationships among variables were examined with principal component analysis and structural equation modelling. Social influence from several contexts was strongly related to current and intended physical activity, particularly among students in work preparing school programmes. Social support in a sport club context provided the strongest unique contribution to the relationship with physical activity, and social support from an outside perspective (e.g. suggestions, help to plan, and positive talk about physical activity), from the contexts school and leisure, had multidimensional effects. Social support could exist in tandem with experiences of negative social influences (e.g. complaints, critique, teasing). In conclusion, it is necessary to expand our understanding of processes that surround supportive as well as negative social influences on adolescents’ level of physical activity and distinguish between main, buffering, and intervening effects of social support.     

High Body Mass Index is not a barrier to physical activity: Analysis of international rugby players’ anthropometric data

Abstract

Recent data indicate that levels of overweight and obesity are increasing at an alarming rate throughout the world. At a population level (and commonly to assess individual health risk), the prevalence of overweight and obesity is calculated using cut-offs of the Body Mass Index (BMI) derived from height and weight. Similarly, the BMI is also used to classify individuals and to provide a notional indication of potential health risk.

It is likely that epidemiologic surveys that are reliant on BMI as a measure of adiposity will overestimate the number of individuals in the overweight (and slightly obese) categories. This tendency to misclassify individuals may be more pronounced in athletic populations or groups in which the proportion of more active individuals is higher. This differential is most pronounced in sports where it is advantageous to have a high BMI (but not necessarily high fatness). To illustrate this point we calculated the BMIs of international professional rugby players from the four teams involved in the semi-finals of the 2003 Rugby Union World Cup. According to the World Health Organisation (WHO) cut-offs for BMI, approximately 65% of the players were classified as overweight and approximately 25% as obese.

These findings demonstrate that a high BMI is commonplace (and a potentially desirable attribute for sport performance) in professional rugby players. An unanswered question is what proportion of the wider population, classified as overweight (or obese) according to the BMI, is misclassified according to both fatness and health risk? It is evident that being overweight should not be an obstacle to a physically active lifestyle. Similarly, a reliance on BMI alone may misclassify a number of individuals who might otherwise have been automatically considered fat and/or unfit.     

Exercise and bone

Abstract

The aim of this study was to examine the interrelationship between aerobic fitness, body composition, and physical activity in 9- and 15-year-olds. The 270 participants were randomly selected from 18 primary and secondary schools in Iceland. Aerobic fitness was assessed by a graded exercise test on a bicycle ergometer. Body composition was estimated via: logarithm of sum of four skinfolds (log_e skinfolds), waist adjusted for height, and body mass index (BMI). Physical activity was measured with Actigraph activity monitors using total activity each day as the physical activity variable. Aerobic fitness was chosen as the primary outcome variable, body composition as the secondary variable, and physical activity as the tertiary variable. All the full models explained a similar proportion of fitness variance for both age groups (45–65%). Among the 15-year-olds, log_e skinfolds explained a significantly larger proportion of the fitness variance (54%) than waist adjusted for height (29%) and BMI (15%), but all the body composition variables explained a similar proportion of the fitness variance (35–42%) among the 9-year-olds. Physical activity explained a smaller proportion (0%) of the unadjusted variance in fitness for the 9-year-olds than for the 15-year-olds (19%). This group difference became non-significant (0% vs. 4%) when adjusting for log_e skinfolds but remained significant when controlling for waist adjusted for height (0% vs. 15%) and BMI (0% vs. 18%). Gender differences in aerobic fitness after puberty can largely be explained by gender differences in log_e skinfolds and physical activity. In conclusion, the interrelationship between fitness, body composition, physical activity, and gender is not the same among 9- and 15-year-olds.     

Characterization of aerobically fit individuals with cardiovascular disease

Abstract

With an ageing population there is an increased prevalence of individuals living with cardiovascular disease (CVD). Characteristics of older aerobically fit individuals with previously diagnosed CVD have not been studied. Therefore, our knowledge is limited as to how, or if, aerobically fit individuals with CVD attempt to adapt their physical activity and the intensity of their training programmes. The objective of this paper is to characterise the physical activity habits and behaviours of older aerobically fit individuals with CVD. We identified 28 aerobically fit patients with CVD from those who completed a minimum of 15 and 12 min of the Bruce treadmill protocol for men and women, respectively. Consenting participants responded to questionnaires regarding physical activity levels, competitive event participation and self-monitoring since diagnosis of heart disease. Average age and treadmill time of participants were 56 and 49 years and 15.6 and 13.0 min for males and females, respectively. Data were obtained regarding recent medical history (medical diagnoses, surgeries/procedures). Despite the majority of individuals participating in the same or more activity since their diagnosis, 25% indicated that their condition limited their activity and 39% reported having symptoms during activity. Nearly all participants (93%) indicated that they monitored their heart rate during exercise. However, only 14% of participants stated that their physician advised them on how to exercise safely. It is necessary for physicians and cardiac rehabilitation programmes to be involved in safe and effective exercise programming to allow individuals to return to sport after CVD.     

A cross-cultural study of adolescents' physical activity levels in France and Spain

Abstract

The goals of this study were (1) to describe and compare levels of physical activity (PA), assessed by accelerometry, of adolescents in two close Spanish and French cities according to gender and period of the week and (2) to assess, with reference to country and gender, the extent to which international PA guidelines were fulfilled. The PA of 401 adolescents (53.37% females) from France and Spain (55.72% French) aged 14.45±0.67 years was assessed with GT3X accelerometers for seven consecutive days to evaluate their habitual levels of moderate to vigorous physical activity (MVPA). Data collection took place from September to December 2010 in six public and state schools in France and Spain. There were significant differences in MVPA in terms of country, gender and period of the week. Spanish adolescents were more active than French adolescents, boys were more active than girls and MVPA was higher on weekdays than at weekends. French girls showed the lowest level of PA. Only 35.9% of the whole sample met the guidelines for PA in both countries. Governments of relevant countries, especially France, should adopt PA promotion policies targeted at adolescents in order to enhance their compliance with PA guidelines.