Relationship between exchange block time in swim starts and final performance in relay races in international championships

Abstract

The purpose of this study was to investigate the association between relay exchange block time and final performance in 4 × 100-m and 4 × 200-m freestyle and 4 × 100-m medley relays as a function of sex (men and women) and classification (medallists and non-medallists) in international competitions. Nineteen international competitions covering a 13-year period (2000–2012) were analysed retrospectively. The data corresponded to a total of 827 team relay histories (407 men, 420 women). Kruskal–Wallis and Mann–Whitney tests were performed to determine any differences by sex, classification, and event. Similarly, the relationship between the exchange block times and final performance was examined by means of a Pearson correlation analysis. In the three events, the men’s exchange block times were shorter than those of the women (η² = 0.049–0.109; P < 0.001). The exchange block time was especially relevant for the women’s relay medallists in the 4 × 100-m freestyle (r = 0.306, P = 0.021) and 4 × 100-m medley (r = 0.385, P = 0.011), while for men the relationship was clearer for the non-medallists. These results suggest that the exchange block time should be considered as one of the performance parameters of swimming relay starts, and thus should be included explicitly as part of training. In particular, the coach could design training targeted at standardising an optimal exchange block time equal to or less than that expected for other teams in the competition.     

Effects of mat characteristics on plantar pressure patterns and perceived mat properties during landing in gymnastics

Shock absorption and stability during landings is provided by both, gymnast ability and mat properties. The aims of this study were to determine the influence of different mat constructions on their energy absorption and stability capabilities, and to analyse how these properties affect gymnast's plantar pressures as well as subjective mat perception during landing. Six mats were tested using a standard mechanical drop test. In addition, plantar pressures and subjective perception during landing were obtained from 15 expert gymnasts. The different mats influenced plantar pressures and gymnasts' subjective perception during landing of gymnasts. Significant correlations between plantar pressures at the medial metatarsal and lateral metatarsal zones of the gymnasts' feet with the different shock absorption characteristics of the mats were found. However, subjective perception tests were not able to discriminate mat functionality between the six mats as no significant correlations between the mechanical mat properties with the subjective perception of these properties were found. This study demonstrated that plantar pressures are a useful tool for discriminating different landing mats. Using similar approaches, ideally including kinematics as well, could help us in our understanding about the influences of different mats upon gymnast-mat interaction.     

The Evolution of the Concept of Capacitance Throughout the Development of the Electric Theory and the Understanding of Its Meaning by University Students

There are few didactic studies concerning the difficulties met by students inunderstanding the meaning of capacitance in a charged body. However, theunderstanding of capacitance can be a good indicator of the Students' learningof electrostatic theory in general. To describe Students' difficulties in learningthis concept we have considered, on the one hand, that individuals constructmental representations in order to help their understanding of the way a physicalsystem works under varied circumstances. On the other hand, a critical study ofthe history and epistemology of science is likely to enlighten us teachers andresearchers about the presence of qualitative leaps in the evolution of a concept.Thus, the consideration by teachers of these `discontinuities between meaningsfor the same concept, may lead them to understand Students' difficulties on learningit. We developed a historical study of the development of the capacitance conceptand an empirical study with students to identify historical and learning difficulties.The results obtained seem to show that most of the students who reason aboutaspects related to the charge of bodies and capacitance feel more comfortablewhen they talk in terms of charge than in terms of electric potential in a similarway to the first explanations of the early electric theories.     

The effects of explicit timing on middle‐school students’ writing production across 5‐ and 15‐min sessions

Enhancing rates of accurate, active, academic responding can enhance learning. Both temporal manipulations (i.e., reducing time to work on assignments) and providing multiple distributed temporal cues (MDTC), sometimes referred to as explicit timing, have been shown to enhance rates of accurate mathematics responding. The current study was designed to evaluate the effects of session length (i.e., 5 vs. 15 min to write) and temporal cues (i.e., a single initial temporal cue vs. MDTC) on seventh‐ and eighth‐grade students writing assignment rates and writing accuracy. Results showed that the 5 min writing sessions did result in significantly greater rates of accurate responding than the 15 min sessions; however, explicit timing did not significantly alter writing rates or accuracy. These findings suggest that educators can enhance rates of accurate writing by reducing writing session lengths. Discussion focuses on applied implications of providing briefer writing sessions and future research investigating the interaction between multiple temporal cues and assignments.     

Which firms want PhDs? An analysis of the determinants of the demand

PhD graduates hold the highest education degree, are trained to conduct research and can be considered a key element in the creation, commercialization and diffusion of innovations. The impact of PhDs on innovation and economic development takes place through several channels such as the accumulation of scientific capital stock, the enhancement of technology transfers and the promotion of cooperation relationships in innovation processes. Although the placement of PhDs in industry provides a very important mechanism for transmitting knowledge from universities to firms, information about the characteristics of the firms that employ PhDs is very scarce. The goal of this paper is to improve understanding of the determinants of the demand for PhDs in the private sector. Three main potential determinants of the demand for PhDs are considered: cooperation between firms and universities, R&D activities of firms and several characteristics of firms, size, sector, productivity and age. The results from the econometric analysis show that cooperation between firms and universities encourages firms to recruit PhDs and point to the existence of accumulative effects in the hiring of PhD graduates.     

PERSONNEL NEEDS IN SCHOOL PSYCHOLOGY: A 10‐YEAR FOLLOW‐UP STUDY ON PREDICTED PERSONNEL SHORTAGES

Concerns regarding whether a sufficient supply of school psychologists exists have been evident for decades. Studies have predicted that school psychology would face a critical personnel shortage that would peak in 2010, but continue into the foreseeable future. The current study is a 10‐year follow‐up investigation based on previously published personnel shortage projections. Data derived from the National Association of School Psychologists 2009–2010 national study were used to examine current personnel shortages as well as to project the extent to which personnel shortages are likely to continue. Findings indicate that the field of school psychology continues to experience a personnel shortage that will continue through 2025. Additionally, greater rates of retirements are projected for the field for school psychologists who are males, who possess a doctoral degree, and for university faculty. Analyses based on the U.S. Census Regions indicate that notable differences are likely to occur in the match between the supply of and demand for school psychologists based on geographical location. Implications are discussed relating to the recruitment and retention of school psychologists and to the services they deliver.     

Government innovation through social media

Social media in government is becoming one of the major trends in Electronic Government (e-government) research and practice worldwide. During the last few years, several authors have addressed the potential of social media for the innovation of public sector organizations. Most of these contributions have focused on the technical dimensions of social media, while other aspects have not attracted equal attention. In contrast, this introductory article interrogates the role of social media in the basic areas of e-government: government information flows and the availability of government information; the use of information technology to create and provide innovative government services; the impact of information technology on the relationships between the governed and those governing; and the increasing importance of information policies and information technologies for democratic practices. Accordingly, the next few pages propose and develop three dimensions of social media in government: tools, goals, and topics. We think that these dimensions could help to better understand the use of social media in government settings. Then, after a brief review of current trends in social media and government research, we present the articles included in this special issue. Finally, we present some practical lessons and suggest ideas for future research. This special issue could be seen as a starting point for the development of innovation through social media in public administrations around the world.     

The measurement of production efficiency in scientific journals through stochastic frontier analysis models: Application to quantitative economics journals

The importance of a scientific journal is usually established by considering the number of citations received by the papers that the journal publishes. In this way, the number of citations received by a scientific journal can be considered as a measure of the total production of the journal. In this paper, in order to obtain measures of the efficiency in the production process, the approach provided by stochastic frontier analysis (SFA) is considered, and econometric models are proposed. These models estimate a frontier production, which is the maximum achievable number of citations to the journal based on its resources. The efficiency can then be measured by considering the difference between the actual production and the estimated frontier. This approach is applied to the measurement of the productive efficiency of the journals of the JCR social sciences edition database, which belong simultaneously to the areas of “economics” and “social sciences, mathematical methods”.     

Spirituality And The Body

Modern spirituality is still challenged by the age-old opposition between matter and spirit. But this traditional dualism has lost some of its sting because modern science itself has been forced to countenance the existence of invisible realities. This article presents some areas of contemporary life in which the spiritual is conspicuously entwined with the material even though the relationship often goes unnoticed. If spirituality can be helped to confront its own tacit acceptance of the material, then it may be possible to move toward a postmodern spirituality, one in which there will be less animosity against, and more acceptance of, the material dimensions of existence.     

Análisis del desarrollo fonológico en sujetos malagueños

Resumen

El presente estudio intenta analizar, desde una perspectiva psicolinguistica, el desarrollo fonológico de niños castellanoparlantes de la ciudad de Málaga, en función de variables como el sexo, el nivel sociocultural y edad de los sujetos, atendiendo, por otra parte, a la influencia de características dialectales del habla andaluza.

Tras la elaboración y administración de una prueba de screening, en condiciones de imitación, se registraron las producciones correctas y distintos procesos de simplificación del habla (sustitución, relativos a la estructura de la sílaba y asimilatorios), no encontrándose diferencias significativas con respecto al sexo, aunque sí en cuanto al nivel sociocultural y a la edad de los sujetos.

Cabe destacar que la influencia del modelo lingüístico andaluz podría enmascarar los patrones evolutivos del desarrollo fonológico infantil. Sin embargo, el hecho de que los sujetos malagueños presenten porcentajes bajos en pronunciación correcta en edades avanzadas, en algunas categorías de fonemas, es debido a la influencia de variantes dialectales, más a que presenten patrones evolutivos más tardíos en cuanto a su capacidad de representación fonológica.