Pole length affects cross-country skiers’ performance in an 80-m double poling trial performed on snow from standing start

We investigated the hypothesis that longer and shorter poles would be faster and slower, respectively, than poles of self-selected length in all-out double poling. Eight elite cross-country skiers performed 80 m all-out double poling on snow performed from a standing start. Three trials with each of the pole lengths: self-selected, 7.5 cm shorter, and 7.5 cm longer than self-selected were performed. Time was recorded every 20 m and skiers were filmed during the last 40 m for calculation of cycle rate and length. Times at 80 m were 0.9 ± 0.7% shorter with longer poles than with self-selected poles (p ≤ 0.05), while they were 1.2 ± 1.0% slower with shorter poles (p ≤ 0.05). Much of these differences were established within the first 20 m. Calculated lead at 80 m with longer poles was 0.88 ± 0.65 m over self-selected poles (p ≤ 0.05). Mean cycle rate and length ranged from 1.35 to 1.45 Hz and from 4.84 to 5.52 m, respectively, across pole lengths (p > 0.05).     

Körperbild und Körperzufriedenheit im Leistungssport

The controversy surrounding the role of competitive sports in the development of eating disorders has increased in recent decades. There are inconsistent findings in the literature concerning the relationship between eating disorders and competitive sports, especially aesthetic sports. The aim of this study was therefore to assess eating disorder-related psychopathology in a sample of competitive figure skaters (FS) representative for competitive aesthetic sports. Special attention is paid to the investigation of body image and body satisfaction. Patients with anorexia nervosa (AN) and a healthy control group (CG) served as comparison groups. None of the FS met the complete diagnostic criteria for an eating disorder. Furthermore no significant differences were observed between the FS and the CG regarding body image and body satisfaction. However, a significant difference was detected compared to the AN patients. Our results underline the necessity for a differentiated analysis and careful diagnostics of sport-specific aspects when considering eating disorder-related psychopathology in competitive sports.     

塔里木盆地水土资源开发及其生态环境效应

塔里木河盆地人口与经济发展而带来的水土资源开发利用程度的增加 ,对盆地生态环境产生了重大的影响。由于上游水土资源开发面积急剧增加 ,导致支流向干流输水逐年减少、年内分配趋于集中、引水口猛增导致干流下游河段断流等水文现象。塔里木盆地水土资源开发到来的效应有积极建设性的一面 ,也有消极的破坏原有生态环境的一面。积极一面主要表现在 :①人工绿洲面积扩大 ,绿洲内部小气候条件改善 ;②土地生产能力提高 ;③水资源有效利用率提高 ;④绿洲内部结构更加完善、趋于稳定等。消极一面主要表现在 :①天然绿洲植被衰退 ;②土地沙漠化和沼泽化、盐渍化并存 ;③河流水质恶化、下游地下水位下降等。塔里木河流域水土资源开发的同时要重视生态环境建设与调控具有重要意义     

Environmental action and student environmental leaders: exploring the influence of environmental attitudes,locus of control,and sense of personal responsibility

The Student Climate and Conservation Congress (SC3) is a joint educational effort between the United States Fish and Wildlife Service and the Green Schools Alliance that aims to develop the next generation of conservation leaders through fostering action competence in youth. Data from SC3 participants was used to investigate four predictors of adult environmental behavior (environmental attitudes, locus of control, sense of personal responsibility, intention) to explore their predictability of environmental action and intention toward future involvement in environmental action in student environmental leaders. Of the four variables explored, pre-program levels of environmental attitudes was a significant predictor of environmental action. Additionally, changes in levels of environmental attitudes significantly predicted environmental action, with an increase in environmental attitudes being associated with a decrease in environmental action. Pre-program levels of environmental attitudes and sense of personal responsibility, and an interaction between the two, potentially were predictors of intention toward future involvement in environmental action. Changes in pre- and post-program levels of environmental attitudes, locus of control, and sense of personal responsibility did not significantly predict intention toward future involvement in environmental action, nor did environmental action. Implications for programming and research, in light of the study’s limitations, are discussed.     

The advantages of an ADHD classification from the perspective of teachers

ABSTRACT

In Western countries, the number of ADHD diagnoses and medical treatments of children has risen spectacularly over the last decennia, as has the amount of criticism about this trend. Various studies have shown that children receiving an ADHD classification often follow from initial signals that were raised in a school context. Hence, it becomes important to investigate precisely what advantages attach to ADHD classification in educational practice. In this qualitative study, 30 teachers were interviewed about their experiences and views of ADHD. The results suggest that a small number of interviewees sees no advantages to ADHD classification: the classification does not practically help them as teachers, they are familiar with the drawbacks of ADHD classification, and they take issue with the idea of labelling children. The greater number of interviewees, however, suggest ambivalence about ADHD classification: they are aware of its drawbacks while experiencing mainly advantages. According to the interviewees, ADHD classification explains undesirable behaviours and disappointing academic achievement. Classification thereby removes blame from pupils, parents and teachers, and so can be a starting point for productive agreement and collaboration. We will discuss the implications of these findings in the light of the concept of reification, child-centred problematisation and the development of more inclusive education.     

Early childhood educators’ use of natural outdoor settings as learning environments: an exploratory study of beliefs,practices, and barriers

In efforts to encourage use of natural outdoor settings as learning environments within early childhood education, survey research was conducted with 46 early childhood educators from northern Minnesota (United States) to explore their beliefs and practices regarding natural outdoor settings, as well investigate predictors of and barriers to the educational use of these settings. Of the beliefs measured, only two were significantly related to frequency of use of natural outdoor settings: belief regarding difficulty in using natural outdoor settings and belief regarding their relationship to nature. The strongest predictor of use was belief regarding difficulty in using natural outdoor settings, accounting for 67.7% of the variance in the regression model. Results indicate primary barriers to be lack of walking access to natural outdoor settings, lack of time, winter weather, and safety concerns. These findings suggest efforts to increase early childhood educators’ use of natural outdoor settings should not focus on influencing their beliefs about the value of using natural outdoor settings in early childhood education, but instead on reducing barriers, thereby making the use of these settings seem more feasible.     

Dynamics of Engineering Education ?Uniformity or Quality

A number of internal and external pressures bear down on engineering colleges today. These include the shortage of experienced manpower, the rapid rate of scientific discoveries requiring absorption in curricula, the increasing college population, competition by industry for faculty members, and the need for additional income for plant expansion and faculty salaries. Within the body of engineering schools, one faction presses for the scientific reorientation of curricula while another holds to the professional art of design as the principle requirement in engineering colleges. Despite the traditional assumption that education is distinguished by large moments of inertia and that the time scale is measured in terms of generations, we lack sufficient time in a world of latent chaos. Positive and exciting internal forces must be injected into our dynamic system.     

Modern Objectives and Methods for Laboratory Instruction

In considering the role of the undergraduate laboratory in an engineering curriculum, it is important that the objectives of the laboratory program be well understood and clearly set forth. It is proposed that the objectives of a modern laboratory program should be: 1) to supplement and strengthen the teaching of subject matter by laboratory methods and 2) to teach the theory and practice of experimentation. A complete laboratory program designed to meet the above objectives should include classroom demonstrations, self-demonstrations, a course on the theory and practice of experimentation, a measurements course, and a senior projects laboratory. The unique features of, such a laboratory program are 1) the self-demonstrations which are designed and programmed much like a teaching machine but which are made up of normal laboratory equipment with which the student carries out an actual physical experiment, and 2) the handling of the theory and practice of experimentation as a body of information which can be taught and which exists as a subject in its own right to be included in an engineering curriculum.