Relations Between Secondary Pupils’ Conceptions About Functions and Problem Solving in Different Representations

The present study explores pupils’ constructed definitions of the concept of function in relation to their abilities in dealing with tasks of functions involving different forms of representations and problem solving tasks. A major concern is also to examine the interrelations between these three ways of thinking about or dealing with the concept of function. The sample of the study consisted of secondary school pupils in Cyprus. A test was developed which involved seven items: one item requested pupils to provide a definition of what function is and the other six items were developed in order to investigate pupils’ ability to transfer information from one representation to another and to solve problems on function. Findings revealed pupils’ difficulties in giving a proper definition for the concept of function and resolving problems on functions involving conversions between diverse modes of representation. Several inconsistencies among pupils’ constructed definitions, their competence to use different representations of functions and their problem solving ability, were also uncovered, indicating lack of flexibility between different ways of approaching functions.     

Muscle performance following an acute bout of plyometric training combined with low or high intensity weight exercise

Abstract

To determine the time course of performance responses after an acute bout of plyometric exercise combined with high and low intensity weight training, a 3-group (including a control group), repeated-measures design was employed. Changes in performance were monitored through jumping ability by measuring countermovement and squat jumping, and strength performance assessment through isometric and isokinetic testing of knee extensors (at two different velocities). Participants in both experimental groups performed a plyometric protocol consisting of 50 jumps over 50 cm hurdles and 50 drop jumps from a 50 cm plyometric box. Additionally, each group performed two basic weight exercises consisting of leg presses and leg extensions at 90–95% of maximum muscle strength for the high intensity group and 60% of maximum muscle strength for the low intensity group. The results of the study suggest that an acute bout of intense plyometric exercise combined with weight exercise induces time-dependent changes in performance, which are also dependent on the nature of exercise protocol and testing procedures. In conclusion, acute plyometric exercise with weight exercise may induce a substantial decline in jumping performance for as long as 72 hours but not in other forms of muscle strength.     

The potential of toe flexor muscles to enhance performance

Abstract

The metatarsal phalangeal joint (MPJ) and its crossing toe flexor muscles (TFM) represent the link between the large energy generating leg extensor muscles and the ground. The purpose of this study was to examine the functional adaptability of TFM to increased mechanical stimuli and the effects on walking, running and jumping performance.

Fifteen men performed a heavy resistance TFM strength training with 90% of the maximal voluntary isometric contraction (MVIC) for 7 weeks (560 contractions) for the left and right foot. Maximal MPJ and ankle plantar flexion moments during MVICs were measured in dynamometers before and after the intervention. Motion analyses (inverse dynamics) were performed during barefoot walking, running, and vertical and horizontal jumping. Athletic performance was determined by measuring jump height and distance.

Left (0.21 to 0.38 Nm · kg^?1; P < 0.001) and right (0.24 to 0.40 Nm · kg^?1; P < 0.001) MPJ plantar flexion moments in the dynamometer, external MPJ dorsiflexion moments (0.69 to 0.75 Nm · kg^?1; P = 0.012) and jump distance (2.25 to 2.31 m; P = 0.006) in horizontal jumping increased significantly.

TFM responded highly to increased loading within a few weeks. The increased force potential made a contribution to an athlete's performance enhancement.     

Flexibility training in preadolescent female athletes: Acute and long-term effects of intermittent and continuous static stretching

This study compared the acute and long-term effects of intermittent and continuous static stretching training on straight leg raise range of motion (ROM). Seventy-seven preadolescent female gymnasts were divided into a stretching (n = 57), and a control group (n = 20). The stretching group performed static stretching of the hip extensors of both legs, three times per week for 15 weeks. One leg performed intermittent (3 × 30 s with 30 s rest) while the other leg performed continuous stretching (90 s). ROM pre- and post-stretching was measured at baseline, on weeks 3, 6, 9, 12, 15 and after 2 weeks of detraining. ROM was increased during both intermittent and continuous stretching training, but remained unchanged in the control group. Intermittent stretching conferred a larger improvement in ROM compared to both continuous stretching and control from week 3, until the end of training, and following detraining (p = 0.045 to 0.001 and d = 0.80 to 1.41). During detraining, ROM after the intermittent protocol decreased (p = 0.001), while it was maintained after the continuous protocol (p = 0.36). Acute increases in ROM following the intermittent stretching were also larger than in the continuous (p = 0.038). Intermittent stretching was more effective than continuous, for both long-term and acute ROM enhancement in preadolescent female athletes.     

Conducting Research into European Union Education and Training Policy: some theoretical and methodological considerations

This paper has several purposes. It introduces a new project funded by the European Commission within its Training and Mobility of Researchers (TMR) programme; it describes the research design of the Oxford part of that project, which is now beginning, and of a comparative study which was already being undertaken in Oxford on the implementation of the ‘European Dimension’ in education in England, Scotland and Wales; and it describes a number of theoretical and methodological problems we anticipate having to address as the studies proceed.     

Head teachers’ leadership for social justice and inclusion

This article is concerned with exploring the ways in which head teachers’ leadership for social justice is understood and enacted within the context of inclusion. Head teachers’ leadership praxis is influenced by individual understandings of social justice, as well as dominant institutional realities and policy priorities that indicate the extent to which there is commitment to the process of socially just change. This commitment is significantly manifested in the ways in which an educational system advances new forms of professionalism, effectiveness indicators and accountability regimes that are aligned with concerns about providing socially just and non-discriminatory learning communities for learner diversity.