621 research outputs found

    Replica Method for Wide Correlators in Gaussian Orthogonal, Unitary And Symplectic Random Matrix Ensembles

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    We calculate connected correlators in Gaussian orthogonal, unitary and symplectic random matrix ensembles by the replica method in the 1/N-expansion. We obtain averaged one-point Green's functions up to the next-to-leading order O(1/N) and wide two-level correlators up to the first nontrivial order O(1/N^2) and wide three-level correlators up to the first nontrivial order O(1/N4)O(1/N^4) by carefully treating fluctuations in saddle-point evaluation.Comment: LaTeX 21 pages, a new result on wide three-level correlators adde

    An asymptotic formula for marginal running coupling constants and universality of loglog corrections

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    Given a two-loop beta function for multiple marginal coupling constants, we derive an asymptotic formula for the running coupling constants driven to an infrared fixed point. It can play an important role in universal loglog corrections to physical quantities.Comment: 16 pages; typos fixed, one appendix removed for quick access to the main result; to be published in J. Phys.

    Dynamics of oscillating scalar field in thermal environment

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    There often appear coherently oscillating scalar fields in particle physics motivated cosmological scenarios, which may have rich phenomenological consequences. Scalar fields should somehow interact with background thermal bath in order to decay into radiation at an appropriate epoch, but introducing some couplings to the scalar field makes the dynamics complicated. We investigate in detail the dynamics of a coherently oscillating scalar field, which has renormalizable couplings to another field interacting with thermal background. The scalar field dynamics and its resultant abundance are significantly modified by taking account of following effects : (1) thermal correction to the effective potential, (2) dissipation effect on the scalar field in thermal bath, (3) non-perturbative particle production events and (4) formation of non-topological solitons. There appear many time scales depending on the scalar mass, amplitude, couplings and the background temperature, which make the efficiencies of these effects non-trivial.Comment: 45 pages, 6 figures; v2: several typos corrected; v3: minor corrections and references added; v4: minor corrections to reflect the published version; v5: minor correction

    Neonatal deafening causes changes in Fos protein induced by cochlear electrical stimulation

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    The influence of neonatal deafness on cochlear electrically evoked Fos expression in the auditory brainstem was examined. Newborn rats were deafened by systemic injection of kanamycin, 1 mg/g daily for 12 days. At 4, 5, 6 or 8 weeks of age, these animals received cochlear electrical stimulation with a basal monopolar electrode for 90 minutes. Age-matched untreated control animals received similar stimulation. Experimental and control animals were assessed for spiral ganglion cell densities and Fos immunoreactive staining in the central nucleus of the inferior colliculus. Spiral ganglion cell assessments showed significant decreases in spiral ganglion cell densities in deafened rats compared to age-matched controls, at 5 weeks of age in lower turns and 6 and 8 weeks in all turns. Cochlear electrical stimulation induced Fos immunoreactive staining in the nucleus of auditory brain stem neurons in treatment and control groups. A significantly greater number of Fos immunoreactive neurons was found in the contralateral central nucleus of inferior colliculus in 5, 6 and 8 week old deafened animals compared to age-matched controls. The increases were larger with a longer duration of deafness. These results suggest that there are changes in auditory processing as a consequence of neonatal deafness.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47464/1/11068_2004_Article_5253210.pd

    Essential contribution of a chemokine, CCL3, and its receptor, CCR1, to hepatocellular carcinoma progression

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    金沢大学がん研究所がん病態制御We previously observed that a chemokine, macrophage inflammatory protein-1 α/CCL3, and its receptor, CCR1, were aberrantly expressed in human hepatocellular carcinoma (HCC) tissues. Here, we show that CCL3 and CCR1 are also expressed in 2 different models of this cancer; N-nitrosodiethylamine (DEN)-induced HCC and HCC induced by hepatitis B virus surface (HBs) antigen-primed splenocyte transfer to myelo-ablated syngeneic HBs antigen transgenic mice. At 10 months after DEN treatment, foci number and sizes were remarkably reduced in CCR1- and CCL3-deficient mice, compared with those of wild-type (WT) mice, although tumor incidence were marginally, but significantly, higher in CCR1- and CCL3-deficient mice than in WT mice. Of note is that tumor angiogenesis was also markedly diminished in CCL3- and CCR1-deficient mice, with a concomitant reduction in the number of intratumoral Kupffer cells, a rich source of growth factors and matrix metalloproteinases (MMPs). Among growth factors and MMPs that we examined, only MMP9 and MMP13 gene expression was augmented progressively in liver of WT mice after DEN treatment. Moreover, MMP9, but not MMP13, gene expression was attenuated in CCR1- and CCL3-deficient mice, compared with that of WT mice. Furthermore, MMP9 was expressed mainly by mononuclear cells but not hepatoma cells, and MMP9-expressing cell numbers were decreased in CCR1- or CCL3-deficient mice, compared with WT mice. These observations suggest the contribution of the CCR1-CCL3 axis to HCC progression. © 2005 Wiley-Liss, Inc
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