Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics. 相似文献
The French orthographic code is complex, and its acquisition is laborious (Catach, 2008; Fayol & Jaffré, 2008). Three hypotheses attempt to explain orthographic knowledge acquisition (OKA). For some, exposure to the code leads to OKA through a self-learning process (Share, 2004). For others, OKA benefits from graphophonological processes (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). Finally, some authors suggest that OKA is possible thanks to visual specific processes (Ans, Carbonnel, & Valdois, 1998). The main goal of this study was to test these hypotheses in a classroom context with comparable samples. In total, 143 2nd-grade children participated in this quasi-experimental study with a pretest, immediate posttest, and delayed posttest design. We assigned participants to one of four conditions. For three conditions, we created three teaching procedures based on each of the hypotheses: frequency of contacts with target words; explicit teaching of graphophonological properties of words; explicit teaching of visual properties of words. The fourth served as a control group. ANOVA analyses indicated that all three experimental conditions favored OKA, showing that the different teaching procedures led to spelling development. However, the visual condition was the most favorable. Three main conclusions can be drawn from this study: (a) models of OKA should account for the different paths that can lead to spelling acquisition; (b) visual properties of words and their acquisition need additional research, and (c) applied research in real classroom contexts is not only relevant for informing teaching practices but also for better understanding how learning takes place.
For many years now, most countries of the world have increasingly valued the headteacher as a powerful force in facilitating school and staff development. Such recognition has resulted in widespread training programmes—even in the poorest countries. In Spain, however, there has been, until very recently, considerable ambiguity over the role of the headteacher. This uncertainty is manifested in the appointment system of headteachers and the lack of commitment to training. This paper seeks to show the reasons for this situation, through an evaluation of recent legislation, the impact of Franco's legacy on education and the current preoccupation with democratic government at all levels. The paper highlights important changes of attitude towards the role of the head now taking place, mainly at local levels, and encourages the government to ensure that examples of effective training, emanating from these ideological shifts, are recognised and contained within national programmes.相似文献
The objective of this study centres on identifying and classifying the conceptions of teaching and learning held by future secondary school teachers, and on analysing the relationship between these conceptions and the way classroom space is organized and exams are designed. The test instruments used were applied to a sample of 138 graduates, who were all following the Pedagogical Aptitude Course (CAP) during the academic year 2002/03. Results show that the more traditional teaching/learning models are related to a more vertical classroom layout. Significant correlations between beliefs and exam demands were also found. 相似文献
AN EXPLORATION OF THE EDUCATIONAL RESILIENCE OF TEACHING STAFF – This study focuses on the degree of resilience displayed
by teaching staff with the aim of promoting their professional development and preventing job-related exhaustion. Seven underprivileged
schools in Montreal were selected, and 24 teaching staff with contrasting personal profiles were interviewed on the subject
of their work. The Alceste software was used to analyse the conversations, which revolved around techniques applied when dealing
with critical incidents. The main analysis identified five different discourses among the respondents. Three of these were
associated with the more resilient of the teachers and two were associated with the more vulnerable ones. Resilient teaching
staff characteristically discussed dealing with aggressive behaviour, the teaching-learning relationship and the subject of
social relationships, whereas vulnerable teaching staff focused on work beyond the classroom, people in positions of higher
authority and the community. The authors note that teachers who are just embarking on their careers appear more vulnerable
than more experienced teaching staff, which suggests that more resources should be provided to support teachers in their profession. 相似文献
Autonomy-supportive parenting is found to foster children’s adjustment but relatively few studies have been conducted with toddlers. In the present exploratory study, parents (N = 182) reported what practices they use when asking their toddlers (M age = 26.9 months) to engage in important yet uninteresting activities. Parents rated twenty-six potentially autonomy-supportive practices, along with a well-known scale measuring the extent to which they have a positive attitude towards autonomy support. Research Findings: Using correlational and factorial analyses, eight practices were identified: various ways to communicate empathy, providing developmentally appropriate rationales, describing the problem in an informational and neutral way, and modeling the requested behavior. This subset of autonomy-supportive practices for toddlers was positively related with toddlers’ rule internalization, providing them with further validity. Practice or Policy: These preliminary findings may be useful in guiding future conceptual, empirical, and applied work on the support of toddlers’ autonomy and its assessment in an emotionally-charged and challenging context. 相似文献
