Different types of compression clothing do not increase sub-maximal and maximal endurance performance in well-trained athletes

Abstract

Three textiles with increasing compressive surface were compared with non-compressive conventional clothing on physiological and perceptual variables during sub-maximal and maximal running. Fifteen well-trained endurance athletes (mean ± s: age 27.1 ± 4.8 years, [Vdot]O_2max 63.7 ± 4.9 ml · min^?1 · kg^?1) performed four sub-maximal (～70%[Vdot]O_2max) and maximal tests with and without different compression stockings, tights, and whole-body compression suits. Arterial lactate concentration, oxygen saturation and partial pressure, pH, oxygen uptake, and ratings of muscle soreness were recorded before, during, and after all tests. In addition, we assessed time to exhaustion. Sub-maximal (P = 0.22) and maximal oxygen uptake (P = 0.26), arterial lactate concentration (P = 0.16; 0.20), pH (P = 0.23; 0.46), oxygen saturation (P = 0.13; 0.26), and oxygen partial pressure (P = 0.09; 0.20) did not differ between the types of clothing (effect sizes = 0.00–0.45). Ratings of perceived exertion (P = 0.10; 0.15), muscle soreness (P = 0.09; 0.10) and time to exhaustion (P = 0.16) were also unaffected by the different clothing (effect sizes = 0.28–0.85). This was the first study to evaluate the effect on endurance performance of different types of compression clothing with increasing amounts of compressive surface. Overall, there were no performance benefits when using the compression garments.     

The dilemma of dealing with persistent teaching traditions: findings of a video study

Nowadays, there is a consensus that good teaching and learning needs instructional variation and personalised forms of learning. In teacher education, these concepts have been implemented for years, and prospective teachers are taught accordingly; it is thus assumed that the teaching of novice teachers is in accordance with these new teaching concepts. In the research project ‘ALPHA’, the teaching of novice teachers at the beginning and at the end of their first year in the profession and the teaching of experienced teachers with five or more years of teaching experience was videotaped, so that longitudinal and cross-sectional comparisons were possible. The lessons were analysed by applying a coding system on the instruction and by employing a rater inventory in order to understand the structure and quality of the lessons. Overall, the results indicate high levels of whole class teaching with a rather high level of traditional classroom instruction both for the novice and the experienced teachers. However, the proportions vary depending on the location of teacher education. The results provide evidence that the new teaching concepts learned on the teacher education programme are not necessarily implemented in the classroom and provide possible reasons why this might be the case.     

University physics students’ ideas of thermal radiation expressed in open laboratory activities using infrared cameras

Background: University physics students were engaged in open-ended thermodynamics laboratory activities with a focus on understanding a chosen phenomenon or the principle of laboratory apparatus, such as thermal radiation and a heat pump. Students had access to handheld infrared (IR) cameras for their investigations.

Purpose: The purpose of the research was to explore students’ interactions with reformed thermodynamics laboratory activities. It was guided by the research question: How do university physics students make use of IR cameras in open-ended investigation of thermal radiation as a phenomenon?

Sample: The study was conducted with a class of first-year university physics students in Sweden. The interaction with the activities of four of the students was selected for analysis. The four students are males.

Design and methods: We used a qualitative, interpretive approach to the study of students’ interaction. The primary means of data collection was video recording of students’ work with the laboratory activities and their subsequent presentations. The analysis focused on how IR cameras helped students notice phenomena relating to thermal radiation, with comparison to previous research on students’ conceptions of thermal radiation.

Results: When using the IR camera, students attended to the reflection of thermal radiation on shiny surfaces, such as polished metals, windows or a whiteboard and emissive properties of surfaces of different types. In this way, they went beyond using the technology as a temperature probe. Students were able to discuss merits and shortcomings of IR cameras in comparison with digital thermometers.

Conclusions: With the help of IR cameras, university physics students attend to thermal phenomena that would otherwise easily go unnoticed.     

民族语言授课远程高等教育发展的比较分析

总结了国内少数民族语言授课远程高等教育的发展过程,并比较分析了同一时期维吾尔语授课和蒙古语授课远程高等教育发展状况,由此提出了创办和发展蒙古语授课现代远程高等教育的启示。     

Strategien zur webbasierten Multilingualen Fragebeantwortung

Zusammenfassung  Wir stellen eine Reihe von innovativen Methoden zur webbasierten multilingualen Fragebeantwortung in offenen Dom?nen vor. Insbesondere werden neuartige Strategien zur Bestimmung optimaler Antwortkontexte und zur Extraktion von exakten Antworten auf Basis von sprachunabh?ngigen, datengetriebenen maschinellen Lernverfahren beschrieben. Es werden zwei alternative Methoden für die crosslinguale Frageanalyse skizziert mit deren Hilfe für eine Anfrage in einer natürlichen Sprache Antworten in Dokumenten einer anderen natürlichen Sprache bestimmt werden k?nnen. Alle Methoden sind detailliert evaluiert und weisen eine vielversprechende Performanz auf. CR subject classification  I.2.6 ; I.2.7 ; J.1 ; K.3.2 ; D.3.3 ; D.2.2     

Prior knowledge in mathematics and study success in engineering: informational value of learner data collected from a web-based pre-course

The article describes the development and evaluation of a web-based pre-course in mathematics, delivered to four cohorts of engineering students at a German university. Based on demographic, personal, and learning-related data relationships between students’ preconditions, their learning gains in the pre-course, and study success in the degree programme were analysed. The results support the existing literature in that domain-related prior knowledge and secondary school achievement play a dominant role regarding study success in engineering. The analyses also showed that the influence of cognitive predictors could only be compensated for by a strong learner engagement. At-risk students with high pre-course learning gains showed significantly better first-year performance. The number of self-tests a student attempted was positively related to pre-course learning gains and even to first-year performance, suggesting that this variable is a good indicator of student engagement.     

Vapor-liquid equilibrium simulation of binary and ternary mixtures of CH4, C2H4 and iso-C4H10

The vapor-liquid equilibrium（VLE） properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solvent.Hence,Gibbs ensemble Monte Carlo（GEMC） simulations were used to estimate vapor-liquid equilibrium for the binary and ternary mixtures of CH4,C2H4 and iso-C4H10 with the united atom potential NERD model.The selected simulation conditions are based on the experiment in the literature.The results of this work were shown to be in satisfactory agreement with available experimental data and predictions of Peng-Robinson equation of state.The structure of simulated liquid phase is also characterized by radial distribution function（RDF）,which contributes to further understanding of the VLE curve of these systems.RDF is not sensitive to the pressure and temperature range.With the increase of pressure or the decrease of temperature,the molecules tend to gather together.     

发挥学会优势 服务科技创新

<正>创新是实现经济迅速发展的原动力,科协是国家推动科技事业发展的重要力量,在国家创新体系中具有独特的组织网络资源优势、特殊的主体地位和不可或缺的作用。近年来,在上级科协领导的指导和支持下,我会充分发挥学会优势,将推动科技创新摆在各项工作的首位,积极调整社会定位,充分发挥学会功能,为推进创新型城市建设做出了积极贡献。