416 research outputs found

    Relative information entropy and Weyl curvature of the inhomogeneous Universe

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    Penrose conjectured a connection between entropy and Weyl curvature of the Universe. This is plausible, as the almost homogeneous and isotropic Universe at the onset of structure formation has negligible Weyl curvature, which then grows (relative to the Ricci curvature) due to the formation of large-scale structure and thus reminds us of the second law of thermodynamics. We study two scalar measures to quantify the deviations from a homogeneous and isotropic space-time, the relative information entropy and a Weyl tensor invariant, and show their relation to the averaging problem. We calculate these two quantities up to second order in standard cosmological perturbation theory and find that they are correlated and can be linked via the kinematic backreaction of a spatially averaged universe model.Comment: 8 pages, matches the published version in Physical Review

    Some studies of dielectric relaxation

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    A general correlation function is firstly reviewed in line with Kubo's formulation (Chap. 1, (a)), and dielectric relaxation processes together with some fundamental properties are considered with the help of the function (Chap. 1, (b)). The Introduction of Hoffmann's site model enables us to calculate a dielectric correlation function. This technique is applied to the dielectric relaxation of some molecules, (Chap. 1 (c)). Discussion with respect to the calculation of the molecular dipole moment for a molecule which contains two equivalent rotational groups is made (Chap. 2, (a)). The results are applied to two convenient models, i.e., a free rotation model and a model called "free oscillation" which is proposed in this thesis. The latter model is employed for the cases of o-haloanisole and o-halothioanisole, Experimental dielectric constant and loss data were analyzed by the Cole-Cole equation as well as Budo's equation (Chap. 3). Rotation of the methoxy group in dimethoxy compounds was examined by relaxation time and dipole moment. The mean relaxation time for o-dimethoxybenzene is found to be short. (Chap. 4). The variation of the relaxation time of the methoxy group of anisole is considered theoretically (Chap. 4, (c)). Mesomeric and double internal rotation mechanisms concerning the anomalously short relaxation time of diphenyl ether are discussed. Correlation function treatments are made based on the former mechanism.( Chap. 5). Rotation around S-S bonds is concluded to be restrictive. (Chap. 6). Relaxation time and dipole moment values of difuryl mercury are explained in terms of the non-linearity of C-Hg-C bond. (Chap. 7)

    Information Entropy in Cosmology

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    The effective evolution of an inhomogeneous cosmological model may be described in terms of spatially averaged variables. We point out that in this context, quite naturally, a measure arises which is identical to a fluid model of the `Kullback-Leibler Relative Information Entropy', expressing the distinguishability of the local inhomogeneous mass density field from its spatial average on arbitrary compact domains. We discuss the time-evolution of `effective information' and explore some implications. We conjecture that the information content of the Universe -- measured by Relative Information Entropy of a cosmological model containing dust matter -- is increasing.Comment: LateX, PRLstyle, 4 pages; to appear in PR

    The Stretcher Operation of KSR (NUCLEAR SCIENCE RESEARCH FACILITY-Particle and Photon Beams)

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    The electron ring KSR has been utilized as a pulse stretcher of the 100 MeV S-band electron linac. The duty factor of the electron beam has been increased drastically more than 90% from 2 10-5

    上顎の形態発生におけるWnt signaling pathwayの役割

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    Cleft lip with or without cleft palate (CLP) usually results from a failure of the medial nasal prominences to fuse with the lateral and maxillary prominences. This failure inhibits facial morphogenesis regulated by several major morphogenetic signaling pathways. We hypothesized that CLP results from the failure of the Wnt signaling pathway. To examine whether Wnt signaling can influences upper jaw development, we applied beads soaked with Dickkopf-1 (Dkk-1), Alsterpaullone (AL) or Wnt3a to the right side of the maxillary prominence of the chick embryo. The embryo showed a defect of the maxilla on the treated side, and skeletal staining revealed hypoplasia of the premaxilla and palatine bone as a result of Dkk-1-soaked bead implantation. 5-bromo-2'-deoxyuridine (BrdU)-positive cell numbers in the treated maxillary prominence were significantly lower at both 24 and 48 hr after implantation. Down-regulation of the expression of Bmp4, Tbx22, Sox9, and Barx1 was confirmed in the maxillary prominence treated with Dkk-1, which indicated that the deformity of the maxillary bone was controlled by gene targets of the Wnt signaling pathway. Expression of N-cadherin was seen immunohistochemically in the maxillary prominences of embryos at 6 hr and increased at 24 hr after AL treatment. Wnt signaling enhanced by AL or Wnt3a up-regulated the expression levels of Msx1, Bmp4, Tbx22, Sox9, and Barx1. Our data suggest that the Wnt signaling pathway regulates maxillary morphogenesis and growth through Bmp4, Tbx22, Sox9, and Barx1. Wnt signaling might regulate N-cadherin expression via Msx1, resulting in cell aggregation for osteochondrogenesis.博士(医学)・乙第1430号・令和元年6月26日© 2019 The Japan Society of Histochemistry and CytochemistryCopyright: © 2019 The author. This is an open access article distributed under the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, istribution, and reproduction in any medium, provided the original work is properly cited.J-STAGEへのリンク : http://dx.doi.org/10.1267/ahc.1803
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