Physiologisch-metabolische Aspekte von Langzeit-Ausdauertests im Schulsport

From the perspective of preventive medicine and learning physiology it is important to introduce children and young people to effective aerobic endurance training. In the field study presented, boys and girls of school years 6, 8, 10 and 12 underwent 3 running tests of 12, 20 and 30 min duration and were tested for lactate concentration, heart rate and rate of perceived exertion (RPE). The physiological metabolic parameters were compared and recommendations for an appropriate long-term endurance test for school sport were given depending on the results. The 12 min running test provoked a higher average lactate concentration (5.3-10.9 mmol/l lactate) in both sexes of all school years than the 2 longer running tests. The average lactate concentrations, however, may be evaluated as quite harmless in school sport provided there is adequate preparation. The longer running tests also require sufficient preparation as they cause average lactate concentrations of approximately 4-8.5 mmol/l and obviously higher demands for volitional properties than shorter running tests. The 20 min running test can be considered as an alternative to the Cooper test (12 min running test): lactate concentrations in blood are between 18.5 % and 23?% lower on average and heart rates and RPE after the test are only slightly higher.     

Capture zone of linear strategies in interception problems with variable structure dynamics

The paper considers planar interception engagements against maneuverable targets using a linearized kinematic model with constant velocities. Both the interceptor and the target have bounded controls and first-order linear dynamics. Due to the linearization, the duration of the interception is prescribed. The target dynamics is fixed, but the interceptor has variable structure dynamics, switching from one mode to another once during the engagement. For such engagements the capture zone of a given linear feedback control is constructed. Numerical examples demonstrate that proper change of the interceptor dynamic mode leads to an enlarged capture zone.     

God–Mother–Baby: What Children Think They Know

This study tested one hundred and nine 3‐ to 6‐year‐old children on a knowledge‐ignorance task about knowledge in humans (mother, baby) and God. In their responses, participants not reliably grasping that seeing leads to knowing in humans (pre‐representational) were significantly influenced by own knowledge and marginally by question format. Moreover, knowledge was attributed significantly more often to mother than baby and explained by agent‐based characteristics. Of participants mastering the task for humans (representational), God was largely conceived as ignorant “man in the sky” by younger and increasingly as “supernatural agent in the sky” by older children. Evidence for egocentrism and for anthropomorphizing God lends support to an anthropomorphism hypothesis. First‐time evidence for an agent‐based conception of others' knowledge in pre‐representational children is presented.     

Implementation eines wissenschaftlich erprobten,didaktischen Konzepts: Der Einfluss pädagogischer Autonomie auf die Wirksamkeit in der Praxis

There is growing interest in evidence-based interventions that can improve student teachers’ professional development. But how can these interventions be implemented into everyday teacher education practice by teacher educators themselves—without losing their initial, lab-tested effectiveness due to teacher educators’ practical educational autonomy? Through a quasi-experimental field study the following question is investigated: What is the impact of different degrees of educational autonomy (low/middle/high) that 19 teacher educa­tors are granted while implementing an experimentally proven concept into their teacher training courses on the development of the competence to diagnose classroom situations among 261 student teachers? ANCOVAs using planned contrasts indicate that the effectiveness of the concept can be sustained in ‘the real world’ of teacher education practice, even if practitioners—no longer researchers—are responsible for the concept realization; thereby, the highest increase in student teachers’ competence occurred when low educational autonomy was granted, i.e., the concept was implemented closely to the original.     

Under-threes’ mathematical learning – teachers’ perspectives

This project highlights preschool teachers’ views of toddlers’ learning in mathematics. The Swedish national curriculum covers even the youngest children who are 1–3?years old. Interesting questions are thus: what should mathematics be for this age group and how should preschool teachers work with maths to achieve the curriculum objectives? Data were collected through interviews with six preschool teachers working in four different preschools. The data show that the teachers emphasize the body as very important for the learning process, which means that for these children, it is not a matter of simply talking about mathematical concepts, but experiencing them bodily. The teachers also report that they now pay more attention than previously to what material the children use and how they interact with it. They are more aware of how they organize and offer the various materials in the preschool and how this influences the way children use them and, consequently, their learning processes.     

Enhancing scientific discovery learning through metacognitive support

Using a virtual physics lab, we analyzed the impact of metacognitive support on simulation-based scientific discovery learning (SDL). The dependent variables for learning outcome were the immediate conceptual knowledge gain and the retained conceptual knowledge three weeks later. Additional dependent variables were the actual use of a domain-specific cognitive strategy, motivation, emotions, and cognitive load. To contrast the effects of metacognitive support with possible effects of goal specificity, the experimental study followed a 2 × 2 design with a sample of N = 129 ninth grade students and with metacognitive support (yes vs. no) and learning goals (specific vs. nonspecific) as factors. The results showed positive effects of metacognitive support on learning outcome, on actual cognitive strategy use, and on learning emotions. No interaction effect of metacognitive support and goal specificity on learning outcome was observed.     

通过身体的城市——相关西方社会理论的评述

本文首先提出了2个当代城市研究的个案,并批判了他们对于城市及其空间建构过程的片面性理解;其次,通过回顾经典的城市理论,本文梳理出了身体、空间和城市之间的相关性;最后,展开了关于当代城市理论的探讨,从空间组织形式的角度去探讨了身体与城市之间的实践关系。总体而言,本文在西方社会理论的脉络中探讨了身体、空间和城市等几个重要概念,并强调了对于"身体"概念的理解有助于我们更好地去理解城市及其内在逻辑。     

Hydrogel-based microfluidic incubator for microorganism cultivation and analyses

This work presents an array of microfluidic chambers for on-chip culturing of microorganisms in static and continuous shear-free operation modes. The unique design comprises an in-situ polymerized hydrogel that forms gas and reagent permeable culture wells in a glass chip. Utilizing a hydrophilic substrate increases usability by autonomous capillary priming. The thin gel barrier enables efficient oxygen supply and facilitates on-chip analysis by chemical access through the gel without introducing a disturbing flow to the culture. Trapping the suspended microorganisms inside a gel well allows for a much simpler fabrication than in conventional trapping devices as the minimal feature size does not depend on cell size. Nutrients and drugs are provided on-chip in the gel for a self-contained and user-friendly handling. Rapid antibiotic testing in static cultures with strains of Enterococcus faecalis and Escherichia coli is presented. Cell seeding and diffusive medium supply is provided by phaseguide technology, enabling simple operation of continuous culturing with a great flexibility. Cells of Saccharomyces cerevisiae are utilized as a model to demonstrate continuous on-chip culturing.     

Influence of mass on the speed of wheelchair racing

Reducing the mass of a racing wheelchair improves the winning time even for relatively small mass reductions over short distances (100 m). In this study, the improvement of speed and winning time on mass reduction was modelled mathematically, the speed profiles of 100 m wheelchair races as well as the rolling resistance and drag area of the athlete–wheelchair system was determined experimentally, and the improvement of the winning time through mass reduction was calculated from the mathematical model and experimental data. For winning times of 30 s, the relative improvement of the winning time is at least equal to the relative reduction of mass. For winning times of 15 s, the relative improvement of the winning time is at least half the relative reduction of mass. A reduction by 1 kg results in an overall improvement of the winning time of about 1–2.3% for winning times of 15–30 s (100-m race). In absolute terms, a mass saving of 1 and 5 kg on a 60-kg system would reduce a 15-s winning time for the 100 m by 0.132 and 0.66 s, respectively, and a 30-s winning time by 0.63 and 2.86 s, respectively. The mass of a wheelchair is the most important parameter for improving the winning time. The influence of the mass on the winning time is 4 or 1.5 times greater than the influence of the rolling friction coefficient, and 4 or 5.5 times greater than the influence of the drag area in a 15 or 30-s race, respectively. These principles should be considered when designing a racing wheelchair.