Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s?1, P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required. 相似文献
These studies examined whether toddlers take their communicative partners' knowledge states into account when communicating with them. In Study 1 , 16 2-year-old children (mean age 2-7) had to ask a parent for help in retrieving a toy. On each trial, a child was first introduced to a new toy that was then placed in 1 of 2 containers on a high shelf. The parent either witnessed these events along with the child or did not because she or he had left the room or had covered her or his eyes and ears. As predicted, when asking for help in retrieving the toy, children significantly more often named the toy, named its location, and gestured to its location when a parent had not witnessed these events than when she or he had. In Study 2, 16 2-year-old children (mean age 2-3) had to ask a parent for help in retrieving a sticker dropped into 1 of 2 identical containers placed out of reach in the far corners of a table. The parent either witnessed, along with the child, which container the sticker was dropped into or did not because her or his eyes were closed. In their requests for help, young 2-year-old children gestured to the sticker's location significantly more often when the parent did not know its location than when she or he did. The implications of these findings for current characterizations of 2-year-old children's ability to assess the knowledge of others is discussed. 相似文献
We reanalyzed data from published studies (Harp & Mayer, 1997, 1998; Mayer & Moreno, 1998, Mayer et al., 1995, 1996) in which college students learned about the formation of lightning, and were then given open-ended problem-solving question. When asked, “What could you do to decrease the intensity of lightning?,” females were approximately eight times more likely than males to refuse to answer on the grounds that nature cannot be altered. The pattern persisted across four data sets involving 810 participants. The results have practical implications for the design of alternative assessment instruments involving open-ended questions and theoretical implications for gender-based differences in verbal communication styles. 相似文献
ABSTRACT The desire to be close to nature and live in tune with it grew as industrialisation, urbanisation and the impact of technology became increasingly ubiquitous at the turn of the twentieth century. Throughout Europe, model schools were established in rural environments. These private reform schools could not solve the problems of public urban schools. Founded on the initiative of teachers and parents, the Schullandheim (rural school hostel) emerged as a new form bringing urban education and schooling close to nature after the First World War in Germany. Even if related pedagogic activities developed at that time in other countries there is no evidence for comparable institutions. Besides tracing the development of Schullandheime, the article shows how the school hostel idea was embedded in the contemporary educational discussion about the influence large cities had on youth and explores the educational and cultural differences within the school hostel movement through the use of visual material. 相似文献
The present study reports an empirical investigation into concept formation of young children. Based on interviews conducted before and after participating in a playfully enacted chemistry lesson at a culture center, it is analyzed how 6-year-old children conceptualize water, molecule, and chemistry. Theoretically, the study is informed by Vygotsky’s cultural-historical perspective on concept formation. The empirical data consist of pre- and post-interviews with children and documentation of their participation in the intermediate activity. This documentation is used in the post-interviews as a mutual ground for talking with the children about what they remember and how they understand the activity they participated in and what the activity intended to illustrate. The results are presented in terms of three inductively generated categories: ‘everyday’, ‘experientially-based’, and ‘generalized experiences’ concepts, respectively. The implications of these findings for early childhood chemistry (science) education are discussed.
While most German anatomy institutes provide only limited information about body donors and their lives, students have expressed a desire to learn more about these individuals, especially about their motivations to donate their bodies for the sake of medical education. In order to gratify this wish, as well as to further humanize body donors, an educational film was compiled, and a study designed to capture the film's effects on medical students. This is the first study using standardized, validated psychological tools to evaluate the impact of an educational film about body donors on students’ empathy and psychological stress levels. The study followed a longitudinal, controlled, and cluster randomized design, including 77 (48 females/29 males) participants who watched the video either before, midway, or after the dissection course. Questionnaires were completed at four points in time applying the Jefferson Scale for Empathy (JSPE-S) and the Interpersonal Reactivity Index (IRI) to measure empathy. Psychological stress levels were recorded by the Brief Symptom Inventory (BSI). Overall, students recommended the film to be shown to all students (median 6.0; maximum on the six-point Likert scale). Viewing the film revealed no significant changes between study groups or over time in JSPE-S sum scores. All groups demonstrated a significant reduction of BSI values before the dissection course actually started and increased values during the course, but both developments appeared not to be associated with the intervention. Overall, the educational film did not correlate with any negative effects on students’ empathy and psychological stress levels, and it was strongly approved of by students, as it provided more humanizing personal information about body donors without violating their anonymity. 相似文献
Minerva - We extend previous research by systematically investigating whether perceptions of scientific authorship vary between domains. Employing regulations for authorship of scientific journals... 相似文献