The effects of linear, nonlinear, and differential motor learning methods on the emergence of creative action in individual soccer players

Objective: The purpose of this study was to compare the effects of linear (LP), nonlinear (NLP), and differential (DL) motor learning methods on the emergence of creative actions in soccer. Method: Sixty-six novice players were randomly allocated to one of three groups, which practiced soccer skills for three months, according to different motor learning methods. In the LP-group, attention was focused on acquiring movement patterns largely through prescriptive instructions and feedback and frequent repetitions. By contrast, in the NLP-group, the aim was to guide the players’ search for movement solutions. This was done by manipulating task constraints to induce practice variability. Finally, in the DL-group, prescriptive instructions were again used, but now to maximize random variation in the practice of movement patterns. Results: Behavioral analysis after the three-month training showed that the number of different actions (i.e., variability) was highest in the NLP-group, followed by DL-group, whereas the LP-group showed the lowest number of different actions. Similarly, the NLP-group and DL-group demonstrated more original and creative actions than the LP-group. Conclusion: In sum, the NLP and DL motor learning methods, which aim to promote motor variability in practice, are most conducive for the emergence of creative actions. Coaches are advised to design training environment that help learners increase their adaptive motor repertoire and creative actions

People�s attitudes towards the use of quarantine in the Covid-19 pandemic in Iran: Validity and reliability study

Background: The purpose of this study was first to translate (into Persian) and evaluate the psychometric properties of the attitudes towards the use of quarantine questionnaires (PAQ). Methods: This methodological study was conducted on 1000 adults� participants in Iran, using convenience sampling. Based on permission from the developer of the scale, it was back-translated. Content validity, exploratory and confirmatory factor analyses were tested. Reliability of the questionnaire was evaluated with test�retest and internal consistency. Results: The adequacy of the sample was acceptable because of the results of the Kaiser�Meyer�Olkin test (0.788), and Bartlett�s test of sphericity revealed statistically significant results (P <.001). Exploratory factor analysis showed the 4-factor structure of the instrument. The reliability of the scale was 0.77 based on internal consistency. Also, the intra-class reliability of the scale was 0.9. The attitude of the maximum number of respondents towards quarantine is positive and they support a quarantine in the pandemic of COVID-19 in Iran. Conclusions: Current study showed that the Persian version of attitudes towards the use of quarantine (PAQ) in the Iranian population including 17 items could be used as a valid and reliable instrument. © 2021 John Wiley & Sons Lt

A carboxy-terminal peptide of the α1-subunit of the dihydropyridine receptor inhibits Ca2+-release channels

Excitation-contraction coupling in skeletal muscle is thought to involve a physical interaction between the α1-subunit of the dihydropyridine receptor (DHPR) and the sarcoplasmic reticulum (SR) Ca2+-release channel (also known as the ryanodine receptor). Considerable evidence has accumulated to suggest that the cytoplasmic loop between domains II and III of the DHPR α1-subunit is at least partially responsible for this interaction. Other parts of this subunit or other subunits may, however, contribute to the functional and/or structural coupling between these two proteins. A synthetic peptide corresponding to a conserved sequence located between amino acids 1487 and 1506 in the carboxy terminus of the α1-subunit inhibits both [3H]ryanodine binding to skeletal and cardiac SR membranes and the activity of skeletal SR Ca2+-release channels reconstituted into planar lipid bilayers. A second, multiantigenic peptide synthesized to correspond to the same sequence inhibits both binding and channel activity at lower concentrations than the linear peptide. These peptides slow the rate at which [3H]ryanodine binds to its high-affinity binding site and decrease the rate at which [3H]ryanodine dissociates from this site. A third polypeptide synthesized in Escherichia coli and corresponding to amino acids 1381-1627 and encompassing the above sequence has similar effects. This portion of the α1-subunit of the transverse tubule DHPR is therefore a candidate for contributing to the interaction of this protein with the Ca2+-release channel

Interaction between ryanodine and neomycin binding sites on Ca2+ release channel from skeletal muscle sarcoplasmic reticulum

Neomycin is a potent inhibitor of skeletal muscle sarcoplasmic reticulum (SR) calcium release. To elucidate the mechanism of inhibition, the effects of neomycin on the binding of [3H]ryanodine to the Ca2+ release channel and on its channel activity when reconstituted into planar lipid bilayer were examined. Equilibrium binding of [3H]ryanodine was partially inhibited by neomycin. Inhibition was incomplete at high neomycin concentrations, indicating noncompetitive inhibition rather than direct competitive inhibition. Neomycin and [3H]ryanodine can bind to the channel simultaneously and, if [3H]ryanodine is bound first, the addition of neomycin will slow the dissociation of [3H]ryanodine from the high affinity site. Neomycin also slows the association of [3H]ryanodine with the high affinity binding site. The neomycin binding site, therefore, appears to be distinct from the ryanodine binding site. Dissociation of [3H]ryanodine from trypsin-treated membranes or from a solubilized 14 S complex is also slowed by neomycin. This complex is composed of polypeptides derived from the carboxyl terminus of the Ca2+ release channel after Arg-4475 (Callaway, C., Seryshev, A., Wang, J. P., Slavik, K., Needleman, D. H., Cantu, C., Wu, Y., Jayaraman, T., Marks, A. R., and Hamilton, S. L. (1994) J. Biol. Chem. 269, 15876-15884). The proteolytic 14 S complex isolated with ryanodine bound produces a channel upon reconstitution into planar lipid bilayers, and its activity is inhibited by neomycin. Our data are consistent with a model in which the ryanodine binding sites, the neomycin binding sites, and the channel-forming portion of the Ca2+ release channel are located between Arg-4475 and the carboxyl terminus

Social-Ecological Determinants of Elite Student Athletes’ Dual Career Development in Hong Kong and Taiwan

[[abstract]]Previous research has encouraged a cultural specific framework to be developed through research in Asian countries, such as China, to help internationalize the findings and help athletes to adapt them to their society and culture. Based on a socioecological framework, this study investigated how social-ecological determinants affect elite student athletes’ (ESA) experience of the socialization process of dual career development in Hong Kong and Taiwan. We interviewed eight ESAs who trained at the national level, studying simultaneously at universities in Hong Kong and Taiwan. Grounded theory techniques and procedures were used to analyze the data. Results revealed that ESAs are affected by interrelated determinants at different levels: individual (career aims, identities, roles, characters, self-efficacy, and motivation), micro-level (coaches, teammates, parents, siblings, physical education [PE] teachers, other teachers, alumni, seniors, and classmates), meso-level (interrelations between individual and micro-level), exo-level (government, financial, policy, academic, medical, and parent–teacher association), macro-level (attitudes, norms, values, beliefs, resources, and culture), and chrono-level (transition).[[notice]]補正完