927 research outputs found

    Cross-linguistic views of gesture usage

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    People have stereotypes about gesture usage. For instance, speakers in East Asia are not supposed to gesticulate, and it is believed that Italians gesticulate more than the British. Despite the prevalence of such views, studies that investigate these stereotypes are scarce. The present study examined peopleÕs views on spontaneous gestures by collecting data from five different countries. A total of 363 undergraduate students from five countries (France, Italy, Japan, the Netherlands and USA) participated in this study. Data were collected through a two-part questionnaire. Part 1 asked participants to rate two characteristics of gesture: frequency and size of gesture for 13 different languages. Part 2 asked them about their views on factors that might affect the production of gestures. The results showed that most participants in this study believe that Italian, Spanish, and American English speakers produce larger gestures more frequently than other language speakers. They also showed that each culture group, even within Europe, put weight on a slightly different aspect of gestures

    Coherent oscillations of electrons in tunnel-coupled wells under ultrafast intersubband excitation

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    Ultrafast intersubband excitation of electrons in tunnell-coupled wells is studied depending on the structure parameters, the duration of the infrared pump and the detuning frequency. The temporal dependencies of the photoinduced concentration and dipole moment are obtained for two cases of transitions: from the single ground state to the tunnel-coupled excited states and from the tunnel-coupled states to the single excited state. The peculiarities of dephasing and population relaxation processes are also taken into account. The nonlinear regime of the response is also considered when the splitting energy between the tunnel-coupled levels is renormalized by the photoexcited electron concentration. The dependencies of the period and the amplitude of oscillations on the excitation pulse are presented with a description of the nonlinear oscillations damping.Comment: 8 pages, 12 figure

    Optical Conductivity and Electronic Structure of CeRu4Sb12 under High Pressure

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    Optical conductivity [s(w)] of Ce-filled skutterudite CeRu4Sb12 has been measured at high pressure to 8 GPa and at low temperature, to probe the pressure evolution of its electronic structures. At ambient pressure, a mid-infrared peak at 0.1 eV was formed in s(w) at low temperature, and the spectral weight below 0.1 eV was strongly suppressed, due to a hybridization of the f electron and conduction electron states. With increasing external pressure, the mid-infrared peak shifts to higher energy, and the spectral weight below the peak was further depleted. The obtained spectral data are analyzed in comparison with band calculation result and other reported physical properties. It is shown that the electronic structure of CeRu4Sb12 becomes similar to that of a narrow-gap semiconductor under external pressure.Comment: 8 pages, 9 figure

    Composition of Ices in Low-Mass Extrasolar Planets

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    We study the formation conditions of icy planetesimals in protoplanetary disks in order to determine the composition of ices in small and cold extrasolar planets. Assuming that ices are formed from hydrates, clathrates, and pure condensates, we calculate their mass fractions with respect to the total quantity of ices included in planetesimals, for a grid of disk models. We find that the composition of ices weakly depends on the adopted disk thermodynamic conditions, and is rather influenced by the initial composition of the gas phase. The use of a plausible range of molecular abundance ratios and the variation of the relative elemental carbon over oxygen ratio in the gas phase of protoplanetary disks, allow us to apply our model to a wide range of planetary systems. Our results can thus be used to constrain the icy/volatile phase composition of cold planets evidenced by microlensing surveys, hypothetical ocean-planets and carbon planets, which could be detected by Corot or Kepler.Comment: Accepted for publication in The Astrophysical Journa

    Changes Over Time in Absolute and Relative Socioeconomic Differences in Smoking: A Comparison of Cohort Studies From Britain, Finland, and Japan

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    INTRODUCTION: Socioeconomic differences in smoking over time and across national contexts are poorly understood. We assessed the magnitude of relative and absolute social class differences in smoking in cohorts from Britain, Finland and Japan over 5-7 years. METHODS: The British Whitehall II study (n=4350), Finnish Helsinki Health Study (n=6328), and Japanese Civil Servants Study (n=1993) all included employed men and women aged 35-68 at baseline in 1997-2002. Follow-up was in 2003-2007 (mean follow-up 5.1, 6.5 and 3.6 years, respectively). Occupational social class (managers, professionals and clerical employees) was measured at baseline. Current smoking and covariates (age, marital status, body mass index and self-rated health) were measured at baseline and follow-up. We assessed relative social class differences using the Relative Index of Inequality (RII) and absolute differences using the Slope Index of Inequality (SII). RESULTS: Social class differences in smoking were found in Britain and Finland, but not in Japan. Age-adjusted relative differences at baseline ranged from RII 3.08 (95% confidence interval 1.99-4.78) among Finnish men to 2.32 (1.24-4.32) among British women, with differences at follow-up greater by 8-58%. Absolute differences remained stable and varied from SII 0.27 (0.15-0.40) among Finnish men to 0.10 (0.03-0.16) among British women. Further adjustment for covariates had modest effects on inequality indices. CONCLUSIONS: Large social class differences in smoking persisted among British and Finnish men and women, with widening tendencies in relative differences over time. No differences could be confirmed among Japanese men or women

    Multipole State of Heavy Lanthanide Filled Skutterudites

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    We discuss multipole properties of filled skutterudites containing heavy lanthanide Ln from a microscopic viewpoint on the basis of a seven-orbital Anderson model. For Ln=Gd, in contrast to naive expectation, quadrupole moments remain in addition to main dipole ones. For Ln=Ho, we find an exotic state governed by octupole moment. For Ln=Tb and Tm, no significant multipole moments appear at low temperatures, while for Ln=Dy, Er, and Yb, dipole and higher-order multipoles are dominant. We briefly discuss possible relevance of these multipole states with actual materials.Comment: 5 pages, 3 figure

    Anomalous negative excursion of carbon isotope in organic carbon after the last Paleoproterozoic glaciation in North America

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    Early Paleoproterozoic time (2.5–2.0 Ga) spanned a critical phase in Earth's history, characterized by repeated glaciations and an increase in atmospheric oxygen (the Great Oxidation Event (GOE)). Following the last and most intense glaciation of this period, marine carbonates record a large positive excursion of ή^(13)C value (termed the “Lomagundi event”) between about 2.2 and 2.1 Ga coinciding with the global appearances of red beds and sulfates, which suggest an accumulation of high levels of atmospheric oxygen. Here we report the discovery of large negative excursions of ή^(13)C in organic matter (down to −55‰) from quartzose sandstones (of the Marquette Range and the Huronian Supergroups, North America) intermediate in age between the last Paleoproterozoic glaciation and the possible onset of the Lomagundi event. The negative excursion is concomitant with the appearance of intensely weathered quartzose sandstones, which may represent hot and humid conditions. There are some interpretations that potentially explain the negative excursions: (1) redeposition of older ^(13)C-depleted kerogen, (2) later post-depositional infiltration of oil, (3) active methane productions by methanogens in shallow-marine environments, or (4) dissociation of methane hydrate. If the latter two were the case, they would provide clues for understanding the environmental change connecting the intense glaciation and an increase in oxygen

    Scalar order: possible candidate for order parameters in skutterudites

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    Phenomenological Landau analysis shows that the properties of ordered phases in some skutterudites are consistently accounted for by a scalar order parameter which preserves the cubic symmetry, even in the ordered phase. A universal value is found for the anisotropy ratio of the transition temperature in a magnetic field, homogeneous magnetization, and induced staggered magnetization. The difference in magnetic behavior between PrFe4_4P12_{12} and PrRu4_4P12_{12} near their phase transitions is explained within a single framework. For the low-field phase of PrFe4_4P12_{12}, the scalar order with the Γ1g\Gamma_{1g} symmetry can explain (i) the absence of field induced dipoles perpendicular to the magnetic field, (ii) isotropic magnetic susceptibility in the ordered phase, (iii) the field angle dependence of the transition temperature, and (iv) the splitting pattern of the 31^{31}P nuclear magnetic resonance (NMR) spectra. It is proposed how the order parameter in SmRu4_4P12_{12} is identified by NMR analysis of a single crystal.Comment: 4 pages, 4 figure

    Spin fluctuations in CuGeO3_3 probed by light scattering

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    We have measured temperature dependence of low-frequency Raman spectra in CuGeO3_3, and have observed the quasi-elastic scattering in the (c,c)(c,c) polarization above the spin-Peierls transition temperature. We attribute it to the fluctuations of energy density in the spin system. The magnetic specific heat and an inverse of the magnetic correlation length can be derived from the quasi-elastic scattering. The inverse of the magnetic correlation length is proportional to (T−TSP)1/2(T-T_{SP})^{1/2} at high temperatures. We compare the specific heat with a competing-JJ model. This model cannot explain quantitatively both the specific heat and the magnetic susceptibility with the same parameters. The origin of this discrepancy is discussed.Comment: 17 pages, REVTeX, 5 Postscript figures; in press in PR

    Enhanced Impurity Scattering due to Quantum Critical Fluctuations

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    It is shown on the basis of the lowest order perturbation expansion with respect to critical fluctuations that the critical fluctuations give rise to an enhancement of the potential scattering of non-magnetic impurities. This qualitatively accounts for the enhancement of the resistivity due to impurities which has been observed in variety of systems near the quantum critical point, while the higher order processes happen to give much larger enhancement as seen from the Ward identity arguments. The cases with dynamical critical exponent zz=2 and zz=3 are discussed explicitly.Comment: Submitted to J. Phys. Soc. Jpn. on 27 September, 200
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