1,527 research outputs found

    Residual interaction effects on deeply bound pionic states in Sn and Pb isotopes

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    We have studied the residual interaction effects theoretically on the deeply bound pionic states in Pb and Sn isotopes. We need to evaluate the residual interaction effects carefully in order to deduce the nuclear medium effects for pion properties, which are believed to provide valuable information on nuclear chiral dynamics. The s- and p-wave πN\pi-N interactions are used for the pion-nucleon residual interactions. We show that the complex energy shifts are around [(10-20)+i(2-7)]keV for 1s states in Sn, which should be taken into account in the analyses of the high precision data of deeply bound pionic 1s1s states in Sn isotopes.Comment: REVTEX4, 6 pages, 5 tables, Submitted to Phys. Rev. C, Some explanations are added in Version

    Effects of high-intensity interval walking training on physical fitness and blood pressure in middle-aged and older people

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    Reproduced from Mayo Clin Proc., with permission), permission is hereby granted to place a pdf of Nemoto, K et al. Effects of high-intensity interval walking training on physical fitness and blood pressure in middle-aged and older people. Mayo Clin Proc. 82 (7):803-811 into the institutional repository of Shinshu University at https://soar-ir.shinshu-u.ac.jp/ArticleMAYO CLINIC PROCEEDINGS. 82(7): 803-811 (2007)journal articl

    Phase transition in inelastic disks

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    This letter investigates the molecular dynamics of inelastic disks without external forcing. By introducing a new observation frame with a rescaled time, we observe the virtual steady states converted from asymptotic energy dissipation processes. System behavior in the thermodynamic limit is carefully investigated. It is found that a phase transition with symmetry breaking occurs when the magnitude of dissipation is greater than a critical value.Comment: 9 pages, 6 figure

    Dynamics of Viscoplastic Deformation in Amorphous Solids

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    We propose a dynamical theory of low-temperature shear deformation in amorphous solids. Our analysis is based on molecular-dynamics simulations of a two-dimensional, two-component noncrystalline system. These numerical simulations reveal behavior typical of metallic glasses and other viscoplastic materials, specifically, reversible elastic deformation at small applied stresses, irreversible plastic deformation at larger stresses, a stress threshold above which unbounded plastic flow occurs, and a strong dependence of the state of the system on the history of past deformations. Microscopic observations suggest that a dynamically complete description of the macroscopic state of this deforming body requires specifying, in addition to stress and strain, certain average features of a population of two-state shear transformation zones. Our introduction of these new state variables into the constitutive equations for this system is an extension of earlier models of creep in metallic glasses. In the treatment presented here, we specialize to temperatures far below the glass transition, and postulate that irreversible motions are governed by local entropic fluctuations in the volumes of the transformation zones. In most respects, our theory is in good quantitative agreement with the rich variety of phenomena seen in the simulations.Comment: 16 pages, 9 figure

    Dynamical brittle fractures of nanocrystalline silicon using large-scale electronic structure calculations

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    A hybrid scheme between large-scale electronic structure calculations is developed and applied to nanocrystalline silicon with more than 105^5 atoms. Dynamical fracture processes are simulated under external loads in the [001] direction. We shows that the fracture propagates anisotropically on the (001) plane and reconstructed surfaces appear with asymmetric dimers. Step structures are formed in larger systems, which is understood as the beginning of a crossover between nanoscale and macroscale samples.Comment: 10 pages, 4 figure

    Phase-Space Metric for Non-Hamiltonian Systems

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    We consider an invariant skew-symmetric phase-space metric for non-Hamiltonian systems. We say that the metric is an invariant if the metric tensor field is an integral of motion. We derive the time-dependent skew-symmetric phase-space metric that satisfies the Jacobi identity. The example of non-Hamiltonian systems with linear friction term is considered.Comment: 12 page

    The potential energy landscape of a model glass former: thermodynamics, anharmonicities, and finite size effects

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    It is possible to formulate the thermodynamics of a glass forming system in terms of the properties of inherent structures, which correspond to the minima of the potential energy and build up the potential energy landscape in the high-dimensional configuration space. In this work we quantitatively apply this general approach to a simulated model glass-forming system. We systematically vary the system size between N=20 and N=160. This analysis enables us to determine for which temperature range the properties of the glass former are governed by the regions of the configuration space, close to the inherent structures. Furthermore, we obtain detailed information about the nature of anharmonic contributions. Moreover, we can explain the presence of finite size effects in terms of specific properties of the energy landscape. Finally, determination of the total number of inherent structures for very small systems enables us to estimate the Kauzmann temperature

    Magnetic local time dependence of geomagnetic disturbances contributing to the AU and AL indices

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    The Auroral Electrojet (AE) indices, which are composed of four indices (AU, AL, AE, and AO), are calculated from the geomagnetic field data obtained at 12 geomagnetic observatories that are located in geomagnetic latitude (GMLAT) of 61.7°-70°. The indices have been widely used to study magnetic activity in the auroral zone. In the present study, we examine magnetic local time (MLT) dependence of geomagnetic field variations contributing to the AU and AL indices. We use 1-min geomagnetic field data obtained in 2003. It is found that both AU and AL indices have two ranges of MLT (AU: 15:00-22:00MLT, ~06:00 MLT; and AL: ~02:00 MLT, 09:00-12:00 MLT) contributing to the index during quiet periods and one MLT range (AU: 15:00-20:00MLT, and AL: 00:00-06:00 MLT) during disturbed periods. These results are interpreted in terms of various ionospheric current systems, such as, Sqp, Sq, and DP2

    Exercise Effects on Methylation of ASC Gene

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    Chronic moderate exercise has been reported to reduce pro-inflammatory cytokines. To analyze the molecular mechanisms by which training exerts these effects, the epigenetic influences of age and exercise on the ASC gene, which is responsible for IL-1 beta and IL-18 secretion, were investigated by ASC gene methylation. Further, the relationship between carcinogenesis and exercise, and methylation of the p15 tumor suppressive gene was also analyzed. High-intensity interval walking exercise, consisting of 3 min low-intensity walking at 40% of peak aerobic capacity followed by a 3 min high-intensity walking period above 70% of peak aerobic capacity, was continued for 6 months. Peripheral blood DNA extracts from young control (n = 34), older control (n = 153), and older exercise (n = 230) groups were then analyzed by pyrosequencing for DNA methylation. Methylation of ASC decreased significantly with age (young control vs. older control, p < 0.01), which is indicative of an age-dependent increase in ASC expression. Compared to the older control group, the degree of ASC methylation was higher in the older exercise group (older control vs. older exercise: p < 0.01), and presumably lower ASC expression. Neither exercise nor age affected the methylation of the p15. In summary, chronic moderate exercise appears to attenuate the age-dependent decrease in ASC methylation, implying suppression of excess pro-inflammatory cytokines through reduction of ASC expression.ArticleINTERNATIONAL JOURNAL OF SPORTS MEDICINE. 31(9):671-675 (2010)journal articl
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