The Virgo High-Resolution CO Survey. II. Rotation Curves and Dynamical Mass Distributions

Based on a high-resolution CO survey of Virgo spirals with the Nobeyama Millimeter-wave Array, we determined the dynamical centers using velocity fields, and derived position-velocity diagrams (PVDs) along the major axes of the galaxies across their dynamical centers. We applied a new iteration method to derive rotation curves (RCs), which reproduce the observed PVDs. The obtained high-accuracy RCs generally show steep rise in the central 100 to 200 pc regions, followed by flat rotation in the disk. We applied a deconvolution method to calculate the surface-mass density (SMD) using the RCs based on two extreme assumptions that the mass distribution is either spherical or thin-disk shaped. Both assumptions give nearly identical results, agreeing with each other within a factor of two at any radii. The SMD distributions revealed central massive cores with peak SMD of 10^4 - 10^5 Msun pc^-2 and total mass within 200 pc radius of the order of about 10^9 Msun Correlation analysis among the derived parameters show that the central CO-line intensity is positively correlated with the central SMD, which suggests that the deeper is the gravitational potential, the higher is the molecular gas concentration in the nuclei regardless morphological types.Comment: PASJ 2003 in press, Latex 12 pages, 6 figures (Bigger gif/ps figures available at http://www.ioa.s.u-tokyo.ac.jp/radio/virgo2

Coherence in parametric fluorescence

We investigate spontaneous four wave mixing (SFWM) in a single-channel side-coupled integrated spaced sequence of resonators (SCISSOR). Analytic expressions for the number of photon pairs generated, as well as the biphoton wave function (joint spectral amplitude) describing the pairs, are derived and numerically computed for different pump pulse durations and numbers of ring resonators. In the limit of a long input pump pulse, we show a strong analogy between super-linear scaling of generation efficiency with respect to the number of rings in the structure and Dicke superradiance. More generally, we discuss in detail the factors that influence the shape of the biphoton wave function, as well as the conditions for observing super-SFWM

Magnetic interactions in transition metal doped ZnO : An abinitio study

We calculate the nature of magnetic interactions in transition-metal doped ZnO using the local spin density approximation and LSDA+\textit{U} method of density functional theory. We investigate the following four cases: (i) single transition metal ion types (Cr, Mn, Fe, Co, Ni and Cu) substituted at Zn sites, (ii) substitutional magnetic transition metal ions combined with additional Cu and Li dopants, (iii) substitutional magnetic transition metal ions combined with oxygen vacancies and (iv) pairs of magnetic ion types (Co and Fe, Co and Mn, etc.). Extensive convergence tests indicate that the calculated magnetic ground state is unusually sensitive to the k-point mesh and energy cut-off, the details of the geometry optimizations and the choice of the exchange-correlation functional. We find that ferromagnetic coupling is sometimes favorable for single type substitutional transition metal ions within the local spin density approximation. However, the nature of magnetic interactions changes when correlations on the transition-metal ion are treated within the more realistic LSDA + \textit{U} method, often disfavoring the ferromagnetic state. The magnetic configuration is sensitive to the detailed arrangement of the ions and the amount of lattice relaxation, except in the case of oxygen vacancies when an antiferromagnetic state is always favored.Comment: 11 pages, 17 figure

Investigation of the thermal expansion and heat capacity of the CaCu3Ti4O12 ceramics

The thermal expansion of the CaCu3Ti4O12 ceramics has been measured over a wide temperature range 120–1200 K. The high quality of the samples under study has been confirmed by good agreement of the results of measurements of the heat capacity in the range 2–300 K and in the vicinity of the phase transition of magnetic nature at 25 K with the data for the single crystal. No anomalies in the thermal expansion that can be associated with the phase transition at 726–732 K assumed by other investigators have been found. The influence exerted on the thermal expansion by the heat treatment of the sample in a helium atmosphere and in air has been investigated

A Study of Dopamine Metabolism in a Patient with Juvenile Parkinsonism by Positron Emission Tomography

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Exhaustive Exercise Enhances Immune Response To Flagellin Via Adrenaline-Mediated Up-Regulation of TLR5 Expression

Objective: We already reported that lipopolysacchride (LPS)-induced tumor necrosis factor (TNF)-α production as a bacterial infection model to induce immune response, was inhibited by exhaustive exercise. However, it remains unclear whether or not the immune response to flagellin (FG), which binds to toll like receptor 5(TLR5) and induces pro-inflammatory cytokine production, is also inhibited by this severe exercise. The aim of this study was to determine whether or not exhaustive exercise affects TNF-α productions after FG injection in mice. Methods: Both exhaustive-exercised (EX; n=12) and non-exercised (N-EX; n=12) male C3H/HeN mice were injected with FG (1 mg/kg, i.v), and blood samples were collected. In addition, to clarify the effect of catecholamine on immune response macrophage and intestinal cells after FG stimulation, RAW264 cells and Caco2 cells were cultured 30min after propranolol (Prop; β-adrenergic receptors blocker) or Ly294002 (Ly; PI3K inhibitor) treatments, and were then stimulated with adrenaline (AD; 1 μM) and FG (5 μg/ml). Moreover, the effect of Prop (10 mg/kg, n=12) on FG-induced TNF-α production in EX mice was also examined. Results: TNF-α in EX group was significantly higher than that in N-EX group after FG injection. In epithelium cells, more intensity of TLR5 localization was observed on the plasma membrane area than in the cytosol area in EX mice, but not N-EX mice. Caco2 cells, but not RAW264 cells, significantly increased the FG-induced TNF-α production using AD treatment. Moreover, Prop treatment attenuated the AD-induced TNF-α production in response to FG in Caco2 cells. Although TLR5 expression on RAW264 cells was significantly decreased after AD treatment, the expression on Caco2 cells was rapidly increased. In fact, we observed the AD-dependent TLR5 translocation from cytoplasm to cell membrane in Caco2 cells, and the membrane translocation was inhibited by Prop and Ly treatment. Moreover, the pretreatment with Prop attenuated the exercise-induced plasma TNF-α response to FG in vivo. Conclusion: Our results suggest that immune response to FG via TLR5 might be enhanced by exhaustive exercise in mice

Rest-UV Absorption Lines as Metallicity Estimator: the Metal Content of Star-Forming Galaxies at z~5

We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z~3. We then apply this relation to a sample of 224 galaxies at 3.5 = 4.8) in COSMOS, for which unique UV spectra from DEIMOS and accurate stellar masses from SPLASH are available. The average galaxy population at z~5 and log(M/Msun) > 9 is characterized by 0.3-0.4 dex (in units of 12+log(O/H)) lower metallicities than at z~2, but comparable to z~3.5. We find galaxies with weak/no Ly-alpha emission to have metallicities comparable to z~2 galaxies and therefore may represent an evolved sub-population of z~5 galaxies. We find a correlation between metallicity and dust in good agreement with local galaxies and an inverse trend between metallicity and star-formation rate (SFR) consistent with observations at z~2. The relation between stellar mass and metallicity (MZ relation) is similar to z~3.5, however, there are indications of it being slightly shallower, in particular for the young, Ly-alpha emitting galaxies. We show that, within a "bathtub" approach, a shallower MZ relation is expected in the case of a fast (exponential) build-up of stellar mass with an e-folding time of 100-200 Myr. Due to this fast evolution, the process of dust production and metal enrichment as a function of mass could be more stochastic in the first billion years of galaxy formation compared to later times.Comment: 20 pages, 13 figures, 4 tables; Submitted to Ap

Detailed Measurements of Characteristic Profiles of Magnetic Diffuse Scattering in ErB2_2C2_2

Detailed neutron diffraction measurements on a single crystalline ErB$_2$C$_2$ were performed. We observed magnetic diffuse scattering which consists of three components just above the transition temperatures, which is also observed in characteristic antiferroquadrupolar ordering compounds HoB$_2$C$_2$ and TbB$_2$C$_2$. The result of this experiments indicates that the antiferroquadrupolar interaction is not dominantly important as a origin of the magnetic diffuse scattering.Comment: 5 pages, 5 figures, submitted to J. Phys. Soc. Jp