Sex differences in elbow and wrist joint loading during the cartwheel and round off with different hand positions performed by young gymnasts

The aim of the study was to determine if sex differences exist in the key elbow and wrist joint injury risk factors during different cartwheel (CW) and round-off (RO) techniques performed by young male and female artistic gymnasts. Sixteen active young gymnasts (8 males and 8 females) performed 30 successful trials of CW and RO with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic and kinetic data were collected for each trial. Two-way repeated measures ANOVA (3 × 2, technique × sex) and effect-sizes (ES) were used for statistical analysis. In conclusion, female gymnasts exhibited greater normalised peak vertical ground reaction forces (VGRF), elbow and wrist compression forces and elbow internal adduction moments during CW and RO skills compared with male gymnasts. In both sexes, the parallel and reverse techniques increased peak VGRF, elbow and wrist compression forces and the elbow internal adduction moment. Increased elbow flexion resulted in decreased peak VGRF, elbow compression forces and elbow internal adduction moment. Injury risk factors including elbow extension and internal adduction moment with axial compression force suggest that a CW and RO in reverse and parallel techniques can be hazardous especially for young female gymnasts.     

The organic chemicals industry of the USSR: a case-study in the measurement of comparative technological sophistication by means of kilogram-prices

The comparative kilogram-price of an equivalent product group in international trade is a rough indication of underlying technological capability. Although there are many theoretical and practical difficulties involved in applying this approach to East-West trade, these difficulties can be minimised by a careful selection of product groups. In this connection, advanced chemical products are particularly suitable because the chemical industry is one in which both kilogram-prices and technological sophistication tend to increase hand-in-hand at successive stages of manufacture. The results of this enquiry are quite striking. From the standpoint of bilateral trade, the kilogram-prices of Soviet and East European exports to the EEC countries are consistently lower than those of corresponding imports from the EEC. Throughout the period 1960–1972 these differentials appears to be closing either very slowly or not at all, while the Soviet and East European share of the EEC marked has remained more or less constant or has declined since the mid-1960's. From the alternative perspective of the “neutral” Yugoslavian market, the kilogram-prices of EEC exports are again consistently higher than those obtained by the Comecon coun tries. Moreover, there has been a considerable eroson in the market share of the Comecon countries since the mid-1960's. These general findings are broadly in line with other kinds of estimates and suggest that in these relatively advanced and dynamic sectors of industry, Soviet and East European technology is at present substantially inferior to that of the Common Market countries.     

Computation of time domain response by numerical inversion of the Laplace transform

A new method for the calculation of time responses of lumped time invariant networks is presented. It is based on the numerical inversion of the Laplace transform and involves the computation of the frequency domain function at pre-assigned complex points and forming a weighted sum. The method exactly inverts a certain number of terms of the Taylor expansion of the time response and is thus equivalent to the methods used for the integration of differential equations. This equivalence is established on two examples. The order of integration can be changed between 1 and 46 without any difficulty. Additional properties resulting from the application of the numerical Laplace transform inversion are also discussed and some novel applications indicated.     

NEW LAW ON HIGHER EDUCATION IN CZECHOSLOVAKIA

The Federal Assembly of the Czechoslovak Socialist Republic approved, on 10 April 1980, the new law (Nr.39/80) on higher education. This law was under preparation nearly three years by the Czech and Slovak ministries of education and representatives of universities and other institutes of higher education as we'll as experts in charge of economic and social development. Starting from 1 September 1980 it will replace the previous law on higher education (Nr. 19/66) that has been in effect since 1966.

The following article, written for “Higher Education in Europe” by Professor Jiri M#akeri?ka, Director of the Research Institute on Engineering Studies in Prague, presents the main elements of this new law.     

Achieving optimum sports performance during Ramadan: some practical recommendations

Muslim athletes should fast from sunrise to sunset each day throughout the 30 days of Ramadan. Most athletes will continue to train throughout Ramadan, and they may also be required to compete at this time, but they will also engage in the religious, cultural, and social activities that Ramadan represents. The available evidence indicates that high-level athletes can maintain performance during Ramadan if physical training, food and fluid intake, and sleep are appropriate and well controlled. Individualized monitoring of athletes may help to prevent fatigue and overtraining and to reduce the risk of consequent illness and injury. The timing and intensity of training may require adjustment to optimize the training response, and training close to or after sunset may have advantages, but this will vary between individual and team sports and between environments that are predominantly Muslim and those that are predominantly non-Muslim. Training late in the day allows nutrition interventions after training to promote adaptations to the training stimulus, to promote recovery, and might help to reduce muscle damage. Sleep deficits have a number of adverse effects on well-being and performance, and athletes should ensure adequate sleep throughout Ramadan. In non-Muslim majority environments, especially in team sports, coaches and athletes should be sensitive to the needs of their team-mates who may be fasting. Event organizers should take account of the needs of Muslim athletes when scheduling the dates and timings of sports competitions.     

Dialogue in the support of learning to teach: a case study of a mentor/mentee pair in a teacher education programme

In this paper, we examine the role of reflection in teacher preparation, specifically within a mentoring relationship between cooperating and preservice teacher. We report findings from a case analysis of this pair who engaged in problem-posing dialogue within pre- and post-conferences around practice over one year of their work together in an elementary-level classroom. The context is an innovative programme in which cooperating teachers pursue their Master’s degree while undergraduates (preservice teachers) complete their elementary education degrees. Our analysis of talk about teaching during six coaching cycles as well as supporting documents illustrates how Jane’s mentoring supported reflective practices and disrupted a notion of a field experience as simply a place to ‘practice’ pedagogical knowledge with corrective feedback. Additionally, we explore the tensions in this approach to mentoring. This case study has implications for teacher educators who seek to bolster teacher preparation through the support of mentoring relationships.     

Method for Computing Time Response of Systems Described by Transfer Functions

A simple numerical method for computing the time domain response of linear time invariant systems described by their transfer functions is presented. The method does not require computation of transfer function poles or residues; it is not influenced by the multiplicity of poles or zeroes, nor does it require computation of the matrix exponential. Rather, it is based on a numerical method for inverting Laplace transforms. It is equivalent to very high order, absolutely stable numerical integration. Stiff systems present no problems.     

Reliability of a measurement technique for achilles tendon length

ABSTRACT

Recently, there has been an increasing amount of literature dealing with new methods of Achilles tendon (AT) length measurement. However, most of these studies measured the AT length between the calcaneus and medial head of the gastrocnemius and the reliability of such a measurement has not been satisfactorily presented. The purpose of this study was to determine the reliability of the measurement of AT length within and between sessions. AT length was measured by using a combination of ultrasound imaging and optoelectronic stereophotogrammetry. Nineteen healthy athletes visited the lab on six different days where the AT length was measured on both lower extremities: 1) from the calcaneus to the mid-point of the medial and lateral heads of the gastrocnemius; and 2) from the calcaneus to the soleus musculotendinous attachment. The reliability results indicated high intraclass correlation coefficients (ICC > 0.8), a low typical error (< 0.6) and a standard error of measurement (SEM < 5.5 mm) for all measured AT lengths on within and between sessions. This non-invasive reliable measurement method may be recommended for sport science research purposes.     

Distributing learning over time: the spacing effect in children's acquisition and generalization of science concepts

The spacing effect describes the robust finding that long‐term learning is promoted when learning events are spaced out in time rather than presented in immediate succession. Studies of the spacing effect have focused on memory processes rather than for other types of learning, such as the acquisition and generalization of new concepts. In this study, early elementary school children (5‐ to 7‐year‐olds; N = 36) were presented with science lessons on 1 of 3 schedules: massed, clumped, and spaced. The results revealed that spacing lessons out in time resulted in higher generalization performance for both simple and complex concepts. Spaced learning schedules promote several types of learning, strengthening the implications of the spacing effect for educational practices and curriculum.     

“Exploring this whole thing of social justice” narrative as a tool for critical sociocultural knowledge development in teacher education

Many teacher education programs provide teachers with opportunities to read, write, and discuss critical pedagogy, with the hope that such work will allow them to develop more equitable and just teaching practices. Yet, there often remains a gap between the theoretical discussions of teaching and learning in teacher education classrooms and the pedagogical practice in those teachers’ K-12 classrooms. In this study, we examine how one teacher, Gabriela, used narratives to make connections between her third-grade classroom and the critical concepts she was exploring in a teacher education course. Embedded within an ethnographic case study of an inservice teacher education program, we used a discourse analytic approach to examine both the sociocultural knowledge and the identities Gabriela constructed through narrative as she engaged with issues of language, race, and power within the course. We consider some of the affordances of narrative in this space, including how it allowed Gabriela to integrate her understandings of multiple course topics, to position herself in multiple ways as a teacher, and to disrupt her existing understandings of race and racism in the classroom. This analysis suggests that critically oriented teacher education programs might more intentionally make space for narrative to connect critical theory and pedagogical practice.