Instrução contendo a estrutura rítmica da habilidade melhora a eficiência na aprendizagem da pernada do nado peito

A aprendizagem de habilidades motoras pode ser promovida mediante instrução visual ou auditiva que transmite informações sobre diversas características da habilidade, tais como espaciais ou rítmicas. Para habilidades aquáticas como a pernada do nado peito, os manuais técnicos enfatizam características espaciais, negligenciando aspectos rítmicos da habilidade, apesar de a teoria da aprendizagem motora considerar o timing relativo uma característica crucial na distinção entre uma habilidade e outra. Objetivou-se analisar o impacto da instrução com e sem a informação sobre a estrutura rítmica correta, transmitida visual ou auditivamente, sobre a aprendizagem da pernada do nado peito. Cinquenta estudantes de Educação Física foram distribuídos em quatro grupos experimentais (instrução auditiva, visual, com e sem informação rítmica correta) e realizaram 400 tentativas de aquisição da pernada do nado peito, mais 50 de retenção e 50 de transferência, durante as quais foram mapeados os índices de pernada, de configuração rítmica e espacial. Os resultados mostraram índices marginalmente melhores (p=0,075), no teste de retenção, dos participantes que receberam a instrução com a informação rítmica correta, e uma forte correlação entre os índices de pernada com os de configuração rítmica ao longo de todo o processo, mas não com os de configuração espacial. Não houve diferença entre os grupos de instrução visual e auditiva. Esses resultados corroboram resultados anteriores sobre os efeitos da informação rítmica na aprendizagem de uma habilidade motora complexa, e reforçam o papel do ritmo na eficiência na execução de uma habilidade e consequentemente na sua aprendizagem.Motor learning can be fostered by visual or auditory instruction conveying information on different features of the skill, like spatial and rhythmic characteristics. For swimming skills like the breaststroke kick, manuals predominantly emphasise spatial features, neglecting rhythmic aspects – even though motor learning considers movement rhythm crucial for distinguishing one skill from another. We aimed to analyse the impact of instruction containing or not the adequate rhythmic pattern information, conveyed by visual or auditory stimulus, on learning the breaststroke kick. Fifty university students, assigned to four experimental groups (auditory, visual, with and without rhythmic information), performed 400 acquisition plus 50 retention and 50 transfer trials during which stroke index, rhythmic and spatial pattern indices and instruction request frequency were mapped. Results showed a marginal difference (p= .075) between higher indices in the retention test of participants receiving information about adequate rhythm, as well as a strong correlation between stroke index and rhythm pattern index, but not with spatial pattern index. No difference between auditory and visual groups was found. This result supports earlier research on the impact of rhythmic information on the learning of complex motor skills, and emphasises the role rhythm plays in skill efficiency and consequently in motor learning

Transferrin-modified chitosan nanoparticles for targeted nose-to-brain delivery of proteins

Nose-to-brain delivery presents a promising alternative route compared to classical blood-brain barrier passage, especially for the delivery of high molecular weight drugs. In general, macromolecules are rapidly degraded in physiological environment. Therefore, nanoparticulate systems can be used to protect biomolecules from premature degradation. Furthermore, targeting ligands on the surface of nanoparticles are able to improve bioavailability by enhancing cellular uptake due to specific binding and longer residence time. In this work, transferrin-decorated chitosan nanoparticles are used to evaluate the passage of a model protein through the nasal epithelial barrier in vitro. It was demonstrated that strain-promoted azide-alkyne cycloaddition reaction can be utilized to attach a functional group to both transferrin and chitosan enabling a rapid covalent surface-conjugation under mild reaction conditions after chitosan nanoparticle preparation. The intactness of transferrin and its binding efficiency were confirmed via SDS-PAGE and SPR measurements. Resulting transferrin-decorated nanoparticles exhibited a size of about 110-150 nm with a positive surface potential. Nanoparticles with the highest amount of surface bound targeting ligand also displayed the highest cellular uptake into a human nasal epithelial cell line (RPMI 2650). In an air-liquid interface co-culture model with glioblastoma cells (U87), transferrin-decorated nanoparticles showed a faster passage through the epithelial cell layer as well as increased cellular uptake into glioblastoma cells. These findings demonstrate the beneficial characteristics of a specific targeting ligand. With this chemical and technological formulation concept, a variety of targeting ligands can be attached to the surface after nanoparticle formation while maintaining cargo integrity

Verbal instruction: requesting an attentional focus does not ensure compliance and better performance

The purposes of this study were to investigate a) the effect of redundant and non-redundant instruction on external focus of attention adoption, b) the effect of adopting an external focus of attention on performance in a front crawl swimming task, and c) the effect of redundancy in the wording of a verbal instruction on the above variables. 43 college students (m/f) aged 17 to 46 swam 25 m crawl at maximum speed, once under each of three conditions: without focus instruction (SF), following a focus instruction (CF) and a redundant focus instruction (CFR), in counterbalanced order. For focus adoption control, after completing the task participants were asked about what they had focused on while swimming. As a measure of performance, time and number of strokes were taken and the stroke index was calculated. The results showed that under redundant focus instruction (CFR) condition, 42 % failed to adopt the attentional focus as asked, and following focus (CF) instruction, 23 %. Under CF condition, the frequency of participants that adopted the focus was higher than of those who did not. Performance did not differ significantly among the three conditions (p>0,05). These findings stress the need of manipulation checks in attentional focus research, regarding both performance and motor learning efficiency, as well as the need for further investigation into the relation between instruction extension and performance

Juegos y ejercicios para estimular la psicomotricidad : cómo fomentar en los niños una actitud positiva hacia el deporte

Conjunto de sugerencias para padres y educadores para organizar ejercicios de gimnasia que permitan favorecer el desarrollo psicomotor de los niños y despertar su afición por la actividad física y los deportes. Se establecen los principios básicos para la práctica de ejercicios con niños pequeños y a continuación se presentan clasificados por grupos de edad y por grado de dificultad. Cada una de las unidades de ejercicios tiene como tema principal un aparato o entorno y se componen de tres partes bien diferenciadas: la primera parte tiene como objetivo la predisposición o calentamiento fisiológico y psicológico. La parte principal corresponde propiamente a los ejercicios educativos, mientras que la parte final consta de ejercicios, juegos o canciones para terminar la unidad.CataluñaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

Verbal language in physical education class: its functions and records

Neste trabalho, estuda-se o uso da linguagem verbal pelo professor na aula de educação física, suas funções e suas variedades, aplicadas ás diversas situações de comunicação. A análise do conceito de educação física e do seu quadro de objetivos permite concluir que a linguagem verbal como meio de comunicação é indispensável para o desenvolvimento das atividades dessa disciplina. Sua função não se restringe á informação. Permite influenciar o comportamento dos alunos e criar o clima emocional necessário á aula. Além disso, contribui para caracterizar o professor como indivíduo e como representante de um papel social. Ao longo desta dissertação, procura-se mostrar que as variedades de linguagem, ou melhor, de registro, estão ligadas ás variedades de situação de comunicação. Numa aula de educação física, distinguem-se três tipos de situação. Em primeiro lugar, aquelas cujo assunto é a aprendizagem motora e nestas a linguagem culta e o vocabulário técnico constituem-se a opção mais adequada, pois permitem uma comunicação precisa e inequívoca, criando o clima de seriedade e concentração necessário á aprendizagem. Em segundo, estariam as situações que tratam da organização da aula. A linguagem coloquial juntamente com o vocabulário técnico popular se revelam como recursos linguístico mais adequados, pois facilitam a comunicação rápida, conferindo á aula de educação física uma imagem descontraída. Finalmente, em situações que tem por tema a transmissão de conhecimento teórico, novamente a linguagem culta e o vocabulário técnico se mostram mais adequados. Ao final, este trabalho procura demonstrar que, se a linguagem culta nem sempre se apresenta como a variedade linguística adequada á aula de educação física, por outro lado, também o emprego sistemático da linguagem coloquial não pode ser considerado ideal. Eria preciso, pois, adequar a linguagem ás exigências particulares da aula de educação física, e ás diferentes situações que nela ocorrem, aproveitando conscientemente as variedades que a linguagem ofereceThis dissertation studies the use of verbal language by teachers in physical education lessons. Its functions and varieties used in different situations of communication. Primarily the analysis of physical education concepts and aims shows that verbal communication is indispensable in that educational process. Its function is not limited to communicating information, but also allows the teacher to influence pupils behavior, and to create the emotional climate required for a particular educational process. Furthermore, it contributes to creating the teachers image both as an individual and as a role performer. The study tries to how language varieties or registers are related to varieties of situation. Whitin a physical education lesson, three types of situation may occur. First, those whose subject is motor learning. In those moments formal language and technical vocabulary should be preferred to warrant precision and inequivocal communication, and to create a climate of seriousness and concentration. Second, those situations whose subject is the organization of activities. Here, colloquial language together with popular technical vocabulary is indicated to facilitate quick communication and to create a relaxed image of physical education. Third, those situations that deal with transmission of theoretical knowledge require technical vocabulary and formal language, also. Finally, this work shows that. If formal language is not the all-around adequate option is physical education linguistic behavior, on the other hand, systematic use of colloquial language is not ideal either. It would be necessary, therefore, that the teacher try to adapt his language to the particular requirements of a physical education lesson, and to the different situations that may occur, by consciously exploiting the varieties offered by verbal languag

Female Perceptions of Male Body Movements

The majority of studies on human physical appearance within the evolutionary psychology framework have focused on static two-dimensional representations of facial and body morphology. While such experiments are useful for testing people’s preferences and reactions to even subtle changes in physical features, there is an inherent limitation with regard to the ecological validity of these types of stimuli. Recent research on female perceptions of male body movements suggests that females derive similar cues of male “quality” from movement as from faces and bodies. Here we review studies on key biological and social characteristics that can be derived from body movements, with a focus on female perception of males, and present evidence for the assertion that male dance movements in particular affect female mate preferences. We support this by reporting preliminary empirical data of studies on (1) cross-cultural similarities and differences in female perceptions of male dance movements and (2) relationships between female perceptions of male dancing, running, and walking. Finally, we present some ideas for future research directions to stimulate the scientific investigation on the significance of male body movements in the context of inter- and intrasexual selection

Analysis of previous perceptual and motor experience in breaststroke kick learning

One of the variables that influence motor learning is the learner’s previous experience, which may provide perceptual and motor elements to be transferred to a novel motor skill. For swimming skills, several motor experiences may prove effective. Purpose. The aim was to analyse the influence of previous experience in playing in water, swimming lessons, and music or dance lessons on learning the breaststroke kick. Methods. The study involved 39 Physical Education students possessing basic swimming skills, but not the breaststroke, who performed 400 acquisition trials followed by 50 retention and 50 transfer trials, during which stroke index as well as rhythmic and spatial configuration indices were mapped, and answered a yes/no questionnaire regarding previous experience. Data were analysed by ANOVA (p = 0.05) and the effect size (Cohen’s d ≥0.8 indicating large effect size). Results. The whole sample improved their stroke index and spatial configuration index, but not their rhythmic configuration index. Although differences between groups were not significant, two types of experience showed large practical effects on learning: childhood water playing experience only showed major practically relevant positive effects, and no experience in any of the three fields hampered the learning process. Conclusions. The results point towards diverse impact of previous experience regarding rhythmic activities, swimming lessons, and especially with playing in water during childhood, on learning the breaststroke kick

Reactivity to Accelerometer Measurement of Children and Adolescents

PURPOSE: Awareness of being monitored can influence participants' habitual physical activity (PA) behavior. This reactivity effect may threaten the validity of PA assessment. Reports on reactivity when measuring the PA of children and adolescents have been inconsistent. The aim of this study was to investigate whether PA outcomes measured by accelerometer devices differ from measurement day to measurement day, and whether the day of the week and the day on which measurement started influence these differences. METHODS: Accelerometer data (Counts per minute, cpm) of children and adolescents (n = 2081) pooled from eight studies in Switzerland with at least 10 hours of daily valid recording were investigated for effects of measurement day, day of the week, and start day using mixed linear regression. RESULTS: The first measurement day was the most active day. Cpm were significantly higher than on the second to the sixth day, but not on the seventh day. Differences in the age-adjusted means between the first and consecutive days ranged from 23 to 45 cpm (3.6-7.1%). In pre-school children, the differences almost reached 10%. The start day significantly influenced PA outcome measures. CONCLUSION: Reactivity to accelerometer measurement of PA is likely to be present to an extent of about 5% on the first day and may introduce a relevant bias to accelerometer-based studies. In pre-school children, the effects are larger than in elementary and secondary school children. As the day of the week and the start day significantly influence PA estimates, researchers should plan for at least one familiarization day in school-age children and randomly assign start days

Transport of antarctic krill (Euphausia superba) across the Scotia Sea. Part II: Krill growth and survival

A time-dependent, size-structured, physiologically based krill growth model was used in conjunction with a circulation model to test the hypothesis that Antarctic krill (Euphausia superba) populations at South Georgia are sustained by import of individuals from upstream regions. Surface phytoplankton concentrations along the simulated drifter trajectories were extracted from historical Coastal Zone Color Scanner (CZCS) measurements and sea ice biota concentrations were calculated from sea ice concentration and extent extracted along drifter trajectories from Special Sensor Microwave/Imager measurements. As additional food sources, a time series of heterotrophic food was constructed from historical data, and time series of detritus concentrations were calculated using phytoplankton concentrations extracted from CZCS measurements together with measured particulate organic carbon to chlorophyll a ratios. These food resources along specified drifter trajectories were then input to the krill growth model to determine the size and viability of krill during transport from the source region to South Georgia. The krill growth model simulations showed that no single food source can support continuous growth of krill during the 58–306 days needed for transport to South Georgia. However, under the current assumptions results indicate that combinations of food sources during the transport time enhanced krill survival, with heterotrophic food and detritus being particularly important during periods of low phytoplankton concentrations. The growth model simulations also showed that larval and juvenile krill originating along the western Antarctic Peninsula can grow to 1+ (14–36 mm) and 2+ (26–45 mm) age and size classes observed at South Georgia during the time needed for transport to this region. Krill originating in the Weddell Sea need 20 months for transport, which allows retention in a potentially high food environment, provided by sea ice, for almost 1 year. Krill then complete transport to South Georgia in the following year and larval and juvenile krill grow to 2+ (26–45 mm) and 3+ (35–60 mm) age and size classes during transport. The results of this study show that the successful transport of krill to South Georgia depends on a multitude of factors, such as the location of the spawning area and timing of spawning, food concentrations during transport, predation, and variations in the location of the Southern Antarctic Circumpolar Current Front (SACCF) and in sea ice extent