Hyogo University of Teacher Education (兵庫教育大学, Hyōgo Kyōiku Daigaku) is a national university in Katō, Hyōgo, Japan, founded as "New Concept University" of Teacher Education for Undergraduate and Graduate in 1978.Graduate School satellite campus in Kobe was established in 2000..
Cosmic voids in the large-scale structure are among the useful probes for testing gravity on cosmological scales. In this paper, we investigate the evolution of voids in the Horndeski theory using the effective field theory (EFT) of dark energy. Modeling the void formation with the dynamics of spherical mass shells, we study how modifications of gravity encoded into the EFT of dark energy change the linearly extrapolated critical density contrast that is relevant for the criterion for void formation, with particular focus on the time-dependent parameter characterizing the effect of kinetic braiding. It is found that the change in the critical density contrast is one order of magnitude smaller than the dimensionless EFT parameter because of a slight imbalance between two compensating effects. We then compute the void abundance using the Sheth-van de Weygaert void size function and demonstrate that it exhibits scale-dependent modifications. It is shown that the modifications to the void size function on small scales are almost entirely determined by the modified linear matter power spectrum, while the modifications on large scales are dominated by the contributions from the linear matter spectrum and the critical density contrast.
The relationship between upper- and lower-limb positioning during standing sprint starts and acceleration performance across developmental stages remains unclear. The purpose of this study was to categorize the standing sprint start postures of participants ranging from elementary school to university students and to examine how these postures influence the time from the start signal to the first foot contact and the 5-m split time during a 50-m sprint. Starting postures were classified as Type A (same-side arm-leg alignment) or Type B (opposite-side arm-leg alignment). Two-way ANOVA revealed a significant main effect for posture type, indicating that Type B generally resulted in a shorter initial acceleration time than did Type A. Furthermore, a significant interaction effect was found for the 5-m split time for boys, with a particularly pronounced trend of decreasing times from lower elementary school to junior high school grades. These findings suggest that contralateral arm-leg positioning during standing sprint starts is associated with early acceleration performance and may reflect developmental changes in coordination relevant to sprint performance and coaching practice.
