80 research outputs found

    Stochastic RR matrix for Uq(An(1))U_q(A^{(1)}_n)

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    We show that the quantum RR matrix for symmetric tensor representations of Uq(An(1))U_q(A^{(1)}_n) satisfies the sum rule required for its stochastic interpretation under a suitable gauge. Its matrix elements at a special point of the spectral parameter are found to factorize into the form that naturally extends Povolotsky's local transition rate in the qq-Hahn process for n=1n=1. Based on these results we formulate new discrete and continuous time integrable Markov processes on a one-dimensional chain in terms of nn species of particles obeying asymmetric stochastic dynamics. Bethe ansatz eigenvalues of the Markov matrices are also given.Comment: 21 pages. Remark 9 added, Typos in Appendix A fixe

    Insights into motor learning from a viewpoint of transcranial magnetic stimulation

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    Several protocols of non-invasive transcranial magnetic stimulation have been developed in the past decades. Single-and paired-pulse transcranial magnetic stimulation are painless, and noninvasive tools to evaluate cortical and corticospinal excitability in cerebral cortex compared with transcranial electric stimulation. Motor evoked potential induced by paired-pulse transcranial magnetic stimulation can particularly assess changes of the cortical excitability after motor learning, such as motor skill and motor practice in sports and functional recovery in rehabilitation. However, the effect of electric current in transcranial magnetic stimulation on pyramidal neuron and interneuron in gray and white matters is not actually understood well yet in the field of sports and rehabilitation sciences. Here, we show the important basic knowledge of neurophysiology and transcranial magnetic stimulation and introduce some studies of cortical plasticity and motor learning by using transcranial magnetic stimulation

    Comparison of stochastic stability boundaries for parametrically forced systems with application to ship rolling motion

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    Numerous accidents caused by parametric rolling have been reported on container ships and pure car carriers (PCCs). A number of theoretical studies have been performed to estimate the occurrence condition of parametric rolling in both regular and irregular seas. Some studies in random wave conditions have been the approximate extension of the occurrence conditions for regular waves (e.g. Maki et al). Furthermore, several researches have been based on the stochastic process in ocean engineering (Roberts and Dostal). This study tackled the parametric rolling in irregular seas from the stability of the system's origin. It provided a novel theoretical explanation of the instability mechanism for two cases: white noise parametric excitation and colored noise parametric excitation. The authors then confirmed the usefulness of the previously provided formulae by Roberts and Dostal through numerical examples.Comment: 10 pages, 4 figure

    Effect of endurance training on excessive CO2 expiration due to lactate production in exercise

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    We attempted to determine the change in total excess volume of CO2 Output (CO2 excess) due to bicarbonate buffering of lactic acid produced in exercise due to endurance training for approximately 2 months and to assess the relationship between the changes of CO2 excess and distance-running performance. Six male endurance runners, aged 19–22 years, were subjects. Maximal oxygen uptake (VO2max), oxygen uptake (VO2) at anaerobic threshold (AT), CO2 excess and blood lactate concentration were measured during incremental exercise on a cycle ergometer and 12-min exhausting running performance (12-min ERP) was also measured on the track before and after endurance training. The absolute magnitudes in the improvement due to training for C02 excess per unit of body mass per unit of blood lactate accumulation (Ala−) in exercise (CO2 excess·mass−1·Δla−), 12-min ERP, VO2 at AT (AT-VO2) and VO2max on average were 0.8 ml·kg−1·l−1·mmol−1, 97.8m, 4.4 ml·kg−1· min−1 and 7.3 ml·kg−1·min−1, respectively. The percentage change in CO2 excess·mass−1·Δla− (15.7%) was almost same as those of VO2max (13.7%) and AT-VO2 (13.2%). It was found to be a high correlation between the absolute amount of change in CO2 excess·mass−1·Δla− and the absolute amount of change in AT-VO2 (r=0.94, P<0.01). Furthermore, the absolute amount of change in C02 excess·mass−1·Δla−, as well as that in AT-VO2 (r=0.92, P<0.01), was significantly related to the absolute amount of change in 12-min ERP (r=0.81, P<0.05). It was concluded that a large CO2excess·mass−1·Δla−1 of endurance runners could be an important factor for success in performance related to comparatively intense endurance exercise such as 3000–4000 m races

    Regional contributions through athletic lessons for elementary school children

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    We have provided athletic lessons for elementary school children for four years. These lessons are at the center of a project that aims to contribute to the local community. Initially, we decided on the following theme: “Have fun, learn to run fast, and stand on the Big Swan track.” To improve children’s competitive abilities, we focused on engaging them in fun activities that would lay the foundation for a life filled with sports; to motivate and engage the children, we gave them a chance to attend track meets as part of the program. This project has great potential, both as a practical approach to Track and Field instruction and as a basis for student volunteer activities in the elementary school teaching course. We believe that faculty members and students of Niigata University of Health and Welfare will be able to connect with many more children in the region through this project

    Effect of acute sodium bicarbonate ingestion on excess CO2 output during incremental exercise

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    The effect of bicarbonate ingestion on total excess volume of CO2 Output (CO2 excess), due to bicaronate buffering of lactic acid in exercise, was studied in eight healthy male volunteers during incremental exercise on a cycle ergometer performed after ingestion (0.3 g · kg−1 body mass) of CaCO3 (control) and NaHCO3 (alkalosis). The resting arterialized venous blood pH (P<0.05) and bicarbonate concentration ([HCO3−]b;P<0.01) were significantly higher in acute metabolic alkalosis [AMA; pH, 7.44 (SD 0.03); [HCO3−]b; 29.4 (SD 1.5) mmol·1-1] than in the control [pH, 7.39 (SD 0.03); [HCO3−]b, 25.5 (SD 1.0) mmol·1−1]. The blood lactate concentrations ([la−]b) during exercise below the anaerobic threshold (AT) were not affected by AMA, while significantly higher [la−]b at exhaustion [12.29 (SD 1.87) vs 9.57 (SD 2.14) mmol·1−1,P < 0.05] and at 3 min after exercise [14.41 (SD 1.75) vs 12.26 (SD 1.40) mmol · l−1,P < 0.05] were found in AMA compared with the control. The CO2 excess increased significantly from the control [3177 (SD 506) ml] to AMA [3897 (SD 381) ml;P < 0.05]. The CO2 excess per body mass was found to be significantly correlated with both the increase of [la−]b from rest to 3 min after exercise (Δ [la−]b;r=0.926,P < 0.001) and with the decrease of [HCO3−]b from rest to 3 min after exercise (Δ [HCO3−]b;r=0.872,P<0.001), indicating that CO2 excess per body mass increased linearly with both Δ [la−b and Δ [HCO3−]b. As a consequence, CO2 excess per body mass per unit increase of [la−]b (CO2 excess·mass−1·Δ [la−]b) was similar for the two conditions. The present results would suggest that the relationship between CO2 excess and blood lactate accumulation was unaffected by acute metabolic alkalosis, because the relative contribution of bicarbonate buffering of lactic acid was the same as in the control
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