MUSCLE ARCHITECTURE AND THE RATIO OF JOINT TORQUE TO MUSCLE VOLUME OF TRICEPS SURAE MUSCLES IN YOUNG MEN AND WOMEN

INTRODUCTION: Muscle volume is a major determinant of joint torque (Fukunaga et al., 2001). However, it is not clear whether there are gender-differences in a relationship between joint torque and muscle volume. It is not clear also about muscle architecture, e.g., physiological cross-sectional area (PCSA) and fascicle length. We aim to compare 1) muscle architecture under the maximal voluntary contraction condition and muscle volume (MVTS) of the triceps surae muscles (TS), and 2) the relationship between MVC and MVTS, for young men and women

Effects of a Supermassive Black Hole Binary on a Nuclear Gas Disk

We study influence of a galactic central supermassive black hole (SMBH) binary on gas dynamics and star formation activity in a nuclear gas disk by making three-dimensional Tree+SPH simulations. Due to orbital motions of SMBHs, there are various resonances between gas motion and the SMBH binary motion. We have shown that these resonances create some characteristic structures of gas in the nuclear gas disk, for examples, gas elongated or filament structures, formation of gaseous spiral arms, and small gas disks around SMBHs. In these gaseous dense regions, active star formations are induced. As the result, many star burst regions are formed in the nuclear region.Comment: 19 pages, 11 figures, accepted for publication in Ap

Characteristics of Japanese wrestlers with respect to function and structure of limbs

It is well known that hypertrophy and strength gain of the human skeletal muscle are induced by muscle training. It has also been shown that the training effect on size and strength of the skeletal muscle are altered the different athletic training protocols (1, 4). From these findings, it seems possible that wrestlers possess the hypertrophied muscle and stronger muscle strength by specific training. In the present study, we assess the functional and structural characteristics of the skeletal muscle in Japanese wrestlers

A Neuroeconomics Approach to Inferring Utility Functions in Sensorimotor Control

Making choices is a fundamental aspect of human life. For over a century experimental economists have characterized the decisions people make based on the concept of a utility function. This function increases with increasing desirability of the outcome, and people are assumed to make decisions so as to maximize utility. When utility depends on several variables, indifference curves arise that represent outcomes with identical utility that are therefore equally desirable. Whereas in economics utility is studied in terms of goods and services, the sensorimotor system may also have utility functions defining the desirability of various outcomes. Here, we investigate the indifference curves when subjects experience forces of varying magnitude and duration. Using a two-alternative forced-choice paradigm, in which subjects chose between different magnitude–duration profiles, we inferred the indifference curves and the utility function. Such a utility function defines, for example, whether subjects prefer to lift a 4-kg weight for 30 s or a 1-kg weight for a minute. The measured utility function depends nonlinearly on the force magnitude and duration and was remarkably conserved across subjects. This suggests that the utility function, a central concept in economics, may be applicable to the study of sensorimotor control

Prediction method of inhomogeneous thermal flux loss in a magnet

Thermal flux loss (FL) is one of the important properties in applications of Nd-Fe-B magnets to electrical and electronic devices. FL is expected to occur inhomogeneously in magnets with a complex shape, because it depends on the strength of the local demagnetizing field. Thus, in terms of their applications, we need to predict the inhomogeneous FL from basic magnetic properties measured for a magnet with a simple shape such as a sphere. In this contribution, we propose a method of predicting inhomogeneous initial flux loss, FLint, in a magnet with a complex shape, and compare the predicted values of FLint with the measured ones for a model magnet. Consequently, the predicted and measured distributions agreed with each other. This result suggests that the proposed method can be applied to the prediction of FLint in magnets with a complicated shape used in electrical and electronic devices. c2006 American Institute of Physic

Clustering data by inhomogeneous chaotic map lattices

A new approach to clustering, based on the physical properties of inhomogeneous coupled chaotic maps, is presented. A chaotic map is assigned to each data-point and short range couplings are introduced. The stationary regime of the system corresponds to a macroscopic attractor independent of the initial conditions. The mutual information between couples of maps serves to partition the data set in clusters, without prior assumptions about the structure of the underlying distribution of the data. Experiments on simulated and real data sets show the effectiveness of the proposed algorithm.Comment: 8 pages, 6 figures. Revised version accepted for publication on Physical Review Letter