Irreversible Circulation of Fluctuation and Entropy Production

Physical and chemical stochastic processes described by the master equation are investigated. In this paper, we examine the entropy production both for the master equation and for the corresponding Fokker-Planck equation. For the master equation, the exact expression of the entropy production was recently derived by Gaspard using the Kolmogorov-Sinai entropy ({\em J.Stat.Phys.}, \textbf{117} (2004), 599; [Errata; \textbf{126} (2006), 1109 ]). Although Gaspard's expression is derived from a stochastic consideration, it should be noted that Gaspard's expression conincides with the thermodynamical expression. For the corresponding Fokker-Planck equation, by using the detailed imbalance relation which appears in the derivation process of the fluctuation theorem through the Onsger-Machlup theory, the entropy production is expressed in terms of the {\em irreversible circulation of fluctuation}, which was proposed by Tomita and Tomita ({\em Prog.Theor.Phys.}, \textbf{51} (1974), 1731). However, this expression for the corresponding Fokker-Planck equation differs from that of the entropy production for the master equation. This discrepancy is due to the difference between the master equation and the corresponding Fokker-Planck equation, namely the former treats discrete events, but the latter equation is an approximation of the former one. In fact, in the latter equation, the original discrete events are smoothed out. To overcome this difficulty, we propose the {\em path weight principle}. By using this principle, the modified expression of the entropy production for the corresponding Fokker-Planck equation coincides with that of the master equation (i.e., the thermodynamical expression) for a simple chemical reaction system and a diffusion system.Comment: 17pages, no figures, to appear in Progreess of Theoretical Physics, Vol. 119, No.

Adaptive Texture Alignment for Japanese Kimono Design

A yukata is a type of traditional Japanese kimono. An alignment of its texture pattern is an important factor of the yukata design. There are rules in the texture alignment of the yukata. The rules are comparratively simple. However, the texture alignment is difficult for the designer because the texture alignment should be performed with consideration to the rules and the wearer's taste, Additioanlly, it is necessary for the designer to create the cutting pattern from a limited length of the kimono cloth. Consequently, a design support system for the yukata is required. We have developed the image processing algorithm to simulate the condition of the texture alignment. It becomes possible to perform the texture alignment based on the traditioonal rule automatically. However, some cutting pattern becomes over length of a standard kimono cloth. In this paper, we describe a multi-agent system for supporting the texture alignment of the yukata. We developed texture alignment agents, and a management agent. The management agent acts management of the wearer's body sizes, the condition of the texture alignment and the cutting pattern and orders to the texture alignment agents to carry out the texture alignment according to the wearer's taste. By repeating trial and error, the realistic texture alignment became possible. </p

EFFECT OF LEG MUSCLE FATIGUE 0N INSTEP SOCCER KICK

The aim of this study was to examine the effect of muscle fatigue on the soccer instep kicking motion. The muscle fatigue was induced by repeated knee extension and flexion until exhaustion. The kicking motions of seven players were captured at 500 Hz using a three-dimensional cinematographic technique before and immediately after the fatigue protocol. We found the muscle fatigue declined the peak linear and angular velocity of the distal segment during kicking. This was most likely attributed to the reduced peak magnitudes of resultant moment and motion-depended interactive moment acting at the knee joint. These results indicated that the muscle fatigue not only declined the muscle force but also induced a worse inter-segmental coordination during kicking

KINETIC COMPARISON OF INSTEP SOCCER KICK BETWEEN PREFERRED AND NON-PREFERRED LEG IN HIGHLY SKILLED PLAYRES

The kinetic differences of soccer instep kicking between the preferred and non-preferred leg were examined. The kicking motions of both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The moments due to muscle force and segmental interactions were computed. Significantly greater ball velocity and shank angular velocity were achieved in the preferred leg. The preferred leg showed a significantly greater muscle moment than that of the non-preferred leg. No marked differences were found for the interactive moment between both legs. The results indicate that the highly skilled soccer players were able to produce a well coordinated inter-segmental motion not only for the preferred leg but also for the non-preferred leg. The faster leg swing observed for the preferred leg was most likely a result of the larger muscle moment

A Truncation Mutation in TBC1D4 in a Family with Acanthosis Nigricans and Postprandial Hyperinsulinemia

Tre-2, BUB2, CDC16, 1 domain family member 4 (TBC1D4) (AS160) is a Rab-GTPase activating protein implicated in insulin-stimulated glucose transporter 4 (GLUT4) translocation in adipocytes and myotubes. To determine whether loss-of-function mutations in TBC1D4 might impair GLUT4 translocation and cause insulin resistance in humans, we screened the coding regions of this gene in 156 severely insulin-resistant patients. A female presenting at age 11 years with acanthosis nigricans and extreme postprandial hyperinsulinemia was heterozygous for a premature stop mutation (R363X) in TBC1D4. After demonstrating reduced expression of wild-type TBC1D4 protein and expression of the truncated protein in lymphocytes from the proband, we further characterized the biological effects of the truncated protein in 3T3L1 adipocytes. Prematurely truncated TBC1D4 protein tended to increase basal cell membrane GLUT4 levels (P = 0.053) and significantly reduced insulin-stimulated GLUT4 cell membrane translocation (P \u3c 0.05). When coexpressed with wild-type TBC1D4, the truncated protein dimerized with full-length TBC1D4, suggesting that the heterozygous truncated variant might interfere with its wild-type counterpart in a dominant negative fashion. Two overweight family members with the mutation also manifested normal fasting glucose and insulin levels but disproportionately elevated insulin levels following an oral glucose challenge. This family provides unique genetic evidence of TBC1D4 involvement in human insulin action

AN ACCURATE ESTIMATION OF THE SPRINGBOARD REACTION FORCE IN VAULTING TABLE OF GYMNASTICS

The purpose of this study was to establish the measurement method of the reaction force from the springboard used in vaulting table of gymnastics. Ten male gymnasts?performed the handspring vault. The springboard was mounted on four force plates. The ground reaction force was obtained at 1000Hz. A high-speed camera at 500Hz sampled the springboard motion. The springboard was modeled as, 1) twenty-nine segment model consisting of three boards, 2) twelve segment model consisting of upper board, 3) two segment model consisting of upper board and 4) one segment model consisting of upper board. Board reaction forces of these models were calculated from GRF and accelerations of segments. Results indicate that the simpler two segment model can be used to accurately calculate the BRF as same as the complicated model (twenty-nine segment)

Contact Analysis and Simulation of Rolled Plastic Film Used for Roof Ventilation in Japanese Greenhouses

Greenhouses are capable of producing a variety of high-value crops year-round. A novel Japanese greenhouse design is gaining popularity because of its automated roll-up ventilation system that is integrated into the roof. However, due to the frequent movement of the roll-up system, the plastic film deteriorates rapidly and typically lasts for only three or four months. In order to better understand the film deterioration, we studied the mechanics involved at the point of contact between the film and the metal greenhouse frame. We found that film deformation and failure were closely related to stretching and creasing, and these processes were observed at the microscopic level. An experimental device was developed to further study the damage to greenhouse film due to the roll-up movement. We concluded that the reduction in film thickness due to static loading or rolling contact was the best predictor of future film damage

Stability of MRI turbulent Accretion Disks

Based on the characteristics of the magnetorotational instability (MRI) and the MRI-driven turbulence, we construct a steady model for a geometrically thin disk using "non-standard" $\alpha$-prescription. The efficiency of the angular momentum transport depends on the magnetic Prandtl number, $Pm = \nu/\eta$, where $\nu$ and $\eta$ are the microscopic viscous and magnetic diffusivities. In our disk model, Shakura-Sunyaev's $\alpha$-parameter has a power-law dependence on the magnetic Prandtl number, that is $\alpha \propto Pm^\delta$ where $\delta$ is the constant power-law index. Adopting Spitzer's microscopic diffusivities, the magnetic Prandtl number becomes a decreasing function of the disk radius when $\delta > 0$. The transport efficiency of the angular momentum and the viscous heating rate are thus smaller in the outer part of the disk, while these are impacted by the size of index $\delta$. We find that the disk becomes more unstable to the gravitational instability for a larger value of index $\delta$. The most remarkable feature of our disk model is that the thermal and secular instabilities can grow in its middle part even if the radiation pressure is negligibly small in the condition $\delta > 2/3$. In the realistic disk systems, it would be difficult to maintain the steady mass accretion state unless the $Pm$-dependence of MRI-driven turbulence is relatively weak.Comment: 9 pages, 6 figures, Accepted for publication in Ap

Group V Phospholipase A2 Induces Leukotriene Biosynthesis in Human Neutrophils through the Activation of Group IVA Phospholipase A2

We reported previously that exogenously added human group V phospholipase A2 (hVPLA2) could elicit leukotriene B4 (LTB4) biosynthesis in human neutrophils (Han, S. K., Kim, K. P., Koduri, R., Bittova, L., Munoz, N. M., Leff, A. R., Wilton, D. C., Gelb, M. H., and Cho, W. (1999) J. Biol. Chem. 274, 11881-11888). To determine the mechanism of the hVPLA2-induced LTB4 biosynthesis in neutrophils, we thoroughly examined the effects of hVPLA2 and their lipid products on the activity of group IVA cytosolic PLA2 (cPLA2) and LTB4 biosynthesis under different conditions. As low as 1 nM exogenous hVPLA2 was able to induce the release of arachidonic acid (AA) and LTB4. Typically, AA and LTB4 were released in two phases, which were synchronized with a rise in intracellular calcium concentration ([Ca2+]i) near the perinuclear region and cPLA2 phosphorylation. A cellular PLA2 assay showed that hVPLA2 acted primarily on the outer plasma membrane, liberating fatty acids and lysophosphatidylcholine (lyso-PC), whereas cPLA2 acted on the perinuclear membrane. Lyso-PC and polyunsaturated fatty acids including AA activated cPLA2 and 5-lipoxygenase by increasing [Ca2+]i and inducing cPLA2 phosphorylation, which then led to LTB4 biosynthesis. The delayed phase was triggered by the binding of secreted LTB4 to the cell surface LTB4 receptor, which resulted in a rise in [Ca2+]i and cPLA2 phosphorylation through the activation of mitogen-activated protein kinase, extracellular signal-regulated kinase 1/2. These results indicate that a main role of exogenous hVPLA2 in neutrophil activation and LTB4 biosynthesis is to activate cPLA2 and 5-lipoxygenase primarily by liberating from the outer plasma membrane lyso-PC that induces [Ca2+]i increase and cPLA2 phosphorylation and that hVPLA2-induced LTB4 production is augmented by the positive feedback activation of cPLA2 by LTB4