4,755 research outputs found
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
FORCE-LENGTH RELATIONSHIPS OF HUMAN GASTROCNEMIUS AND SOLEUS MUSCLES IN VIVO
INTRODUCTION: Synergistic muscle have different architecture, and therefore could have different force-length relationships for the same joint angle changes. Previous studies have failed to reveal the force-length relationships of synergistic muscles. The purpose of this study was to investigate the force-length relationships of the triceps surae muscles for humans in vivo
CHANGES IN FORCE-LENGTH RELATIONSHIP OF TRICEPS SURAE MUSCLES AFTER REPEATED ECCENTRIC-CONCENTRIC EXERCISES
INTRODUCTION: Postexercise muscle soreness develops gradually 24 to 48 hours after an eccentric exercise. The prolonged reduction of maximal voluntary force also occurs after eccentric exercise (Nosaka et al, 1991). The reduction in maximal force is thought to be due to peripheral muscle damage derived by eccentric lengthening, but the exact mechanisms are yet to be discovered. One possibility of the reduction in force is the shifting of the optimal length for force production (Prasartwuth et al. 2006). In this study we tested this possibility for the human triceps surae muscles
Structural Insights into Differences in Drug-binding Selectivity between Two Forms of Human α1-Acid Glycoprotein Genetic Variants, the A and F1*S Forms
Human α1-acid glycoprotein (hAGP) in serum functions as a carrier of basic drugs. In most individuals, hAGP exists as a mixture of two genetic variants, the F1*S and A variants, which bind drugs with different selectivities. We prepared a mutant of the A variant, C149R, and showed that its drug-binding properties were indistinguishable from those of the wild type. In this study, we determined the crystal structures of this mutant hAGP alone and complexed with disopyramide (DSP), amitriptyline (AMT), and the nonspecific drug chlorpromazine (CPZ). The crystal structures revealed that the drug-binding pocket on the A variant is located within an eight-stranded β-barrel, similar to that found in the F1*S variant and other lipocalin family proteins. However, the binding region of the A variant is narrower than that of the F1*S variant. In the crystal structures of complexes with DSP and AMT, the two aromatic rings of each drug interact with Phe-49 and Phe-112 at the bottom of the binding pocket. Although the structure of CPZ is similar to those of DSP and AMT, its fused aromatic ring system, which is extended in length by the addition of a chlorine atom, appears to dictate an alternative mode of binding, which explains its nonselective binding to the F1*S and A variant hAGPs. Modeling experiments based on the co-crystal structures suggest that, in complexes of DSP, AMT, or CPZ with the F1*S variant, Phe-114 sterically hinders interactions with DSP and AMT, but not CPZ. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc
SUGGESTION TO ROWERS OBTAINED BY INVERSE DYNAMICS AND FUZZY MODELING
The aims of this study were to clarify the relationships between rower’s partial motions and the rowing performance, i.e. boat speed and efficiency, and to suggest the rower which part of the body he/she should concentrate on. Inverse dynamics found time-series patterns of joint torque power. The power patterns were parameterized to six parameters, amounts and timings of three partial motions, i.e. leg extension, trunk swing and arm pull, during the driving phase of rowing stroke. These parameters are easy for a rower to sense and control one by one. Fuzzy modeling identified the relationship between the parameters and the performance. The obtained linguistic fuzzy rules gave effective suggestion to each rower
An Emulator of Timing, Trigger and Control (TTC) System for the ATLAS End cap Muon Trigger Electronics
A Simple Iterative Algorithm for Parsimonious Binary Kernel Fisher Discrimination
By applying recent results in optimization theory variously known as optimization transfer or majorize/minimize algorithms, an algorithm for binary, kernel, Fisher discriminant analysis is introduced that makes use of a non-smooth penalty on the coefficients to provide a parsimonious solution. The problem is converted into a smooth optimization that can be solved iteratively with no greater overhead than iteratively re-weighted least-squares. The result is simple, easily programmed and is shown to perform, in terms of both accuracy and parsimony, as well as or better than a number of leading machine learning algorithms on two well-studied and substantial benchmarks
- …