METAL DEFICIENCY IN CLUSTER STAR-FORMING GALAXIES AT<i>Z</i>= 2

Valentino, F.,Daddi, E.,Strazzullo, V.,Gobat, R.,Onodera, M.,Bournaud, F.,Juneau, S.,Renzini, A.,Arimoto, N.,Carollo, M.,Zanella, A. IOP Publishing 2015 The Astrophysical journal Vol.801 No.2

<P>We investigate the environmental effect on the metal enrichment of star-forming galaxies (SFGs) in the farthest spectroscopically confirmed and X-ray-detected cluster, CL J1449+0856 at z = 1.99. We combined Hubble Space Telescope/WFC3 G141 slitless spectroscopic data, our thirteen-band photometry, and a recent Subaru/Multi-object InfraRed Camera and Spectrograph (MOIRCS) near-infrared spectroscopic follow-up to constrain the physical properties of SFGs in CL J1449+0856 and in a mass-matched field sample. After a conservative removal of active galactic nuclei, stacking individual MOIRCS spectra of 6 (31) sources in the cluster (field) in the mass range 10 <= log(M/M-circle dot) <= 11, we find a similar to 4 sigma. lower [N II]/H alpha ratio in the cluster than in the field. Stacking a subsample of 16 field galaxies with H beta and [O III] in the observed range, we measure an [O III]/H beta ratio fully compatible with the cluster value. Converting these ratios into metallicities, we find that the cluster SFGs are up to 0.25 dex poorer in metals than their field counterparts, depending on the adopted calibration. The low metallicity in cluster sources is confirmed using alternative indicators. Furthermore, we observe a significantly higher H alpha luminosity and equivalent width in the average cluster spectrum than in the field. This is likely due to the enhanced specific star formation rate; even if lower dust reddening and/or an uncertain environmental dependence on. the continuum-to-nebular emission differential reddening may play a role. Our findings might be explained by the accretion of pristine gas around galaxies at z = 2 and from cluster-scale reservoirs, possibly connected with a phase of rapid halo mass assembly at z > 2 and of a high galaxy merging rate.</P>

An extremely young massive clump forming by gravitational collapse in a primordial galaxy

Zanella, A.,Daddi, E.,Le Floc’h, E.,Bournaud, F.,Gobat, R.,Valentino, F.,Strazzullo, V.,Cibinel, A.,Onodera, M.,Perret, V.,Renaud, F.,Vignali, C. Nature Publishing Group, a division of Macmillan P 2015 Nature Vol.521 No.7550

When cosmic star formation history reaches a peak (at about redshift z ≈ 2), galaxies vigorously fed by cosmic reservoirs are dominated by gas and contain massive star-forming clumps, which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges. Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses, coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies.

Molecular Analysis of Archaea, Bacteria and Eucarya Communities in the Rumen - Review-

White, B.A.,Cann, I.K.O.,Kocherginskaya, S.A.,Aminov, R.I.,Thill, L.A.,Mackie, R.I.,Onodera, R. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.1

If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.

A study on the Raman spectra of Al-doped and Ga-doped ZnO ceramics

Jang, M.S.,Ryu, M.K.,Yoon, M.H.,Lee, S.H.,Kim, H.K.,Onodera, A.,Kojima, S. Elsevier 2009 Current Applied Physics Vol.9 No.3

Al<SUB>x</SUB>Zn<SUB>1-x</SUB>O and Ga<SUB>y</SUB>Zn<SUB>1-y</SUB>O ceramics were synthesized through a solid-state reaction technique. The crystal phase of the samples was identified by an X-ray diffraction experiment. For each sample, the electrical resistivity was determined. The Al 2-mol%-doped and Ga 0.5-mol%-doped ZnO ceramics had the lowest resistivity. Raman measurement was performed to study the doping effects in the ZnO ceramics including ZnO single crystal as a reference. The line-shape parameters, q<SUB>1</SUB> and Γ<SUB>1</SUB>, at the same certain doping rate and the solubility limit of Al (2mol%) and Ga (0.5mol%) in ZnO ceramics, are strongly related to the each other, and that the solubility limit plays an important role. The second-order Raman peak at 1162cm<SUP>-1</SUP> of the ZnO ceramics was fitted by Fano formalism. The Fano's fitting parameters, such as the lifetime of phonon and the degree of asymmetry degree of the second-order Raman peak changed as the amounts of dopants were varied.

A study on the Raman spectra of Al-doped and Ga-doped ZnO ceramics

장민수,류민기,이순현,김형국,A. Onodera,S. Kojima,윤명희 한국물리학회 2009 Current Applied Physics Vol.9 No.3

AlxZn1-xO and GayZn1-yO ceramics were synthesized through a solid-state reaction technique. The crystal phase of the samples was identified by an X-ray diffraction experiment. For each sample, the electrical resistivity was determined. The Al 2-mol%-doped and Ga 0.5-mol%-doped ZnO ceramics had the lowest resistivity. Raman measurement was performed to study the doping effects in the ZnO ceramics including ZnO single crystal as a reference. The line-shape parameters, q1 and C1, at the same certain doping rate and the solubility limit of Al (2 mol%) and Ga (0.5 mol%) in ZnO ceramics, are strongly related to the each other, and that the solubility limit plays an important role. The second-order Raman peak at 1162 cm-1 of the ZnO ceramics was fitted by Fano formalism. The Fano’s fitting parameters, such as the lifetime of phonon and the degree of asymmetry degree of the second-order Raman peak changed as the amounts of dopants were varied.

Phase Transition in Ferroelectric SrBi$_2$Ta$_2$O$_9$ Single Crystal

K. Yoshio,A. Onodera,A. Yamada,A. Sakai,H. Yamashita,I. Matsubara 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV

Single plate-like crystal of Bi-layered ferroelectric perovskite SrBi2Ta2O9 was prepared by self- ux method. Temperature dependence of the lattice constant c, specic heat, Raman scattering were measured to study phase transitions in SrBi2Ta2O9. There are clear anomalies at 613 K (Tc) and 850 K (T) in the c-axis. The mechanism of this phase transition was discussed in terms of Dzialoshinsky-Moriya-type interaction.

Effects of Isopropyl Alcohol Infusions on the Ruminating Behavior of Goats

Asato, N.,Hirata, T.,Hirayama, T.,Onodera, R.,Shinjo, A.,Oshiro, S. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.8

Metabolites, such as isopropyl alcohol (IPA) produced by rumen fermentation, were intravenously infused into a jugular vein of goats during feeding to explore the mechanism and roles of IPA in ruminating behavior (number of boli and ruminating time). Three female goats were confined in metabolism cages with a stanchion, The ruminating behavior measured by the number of ruminations, ruminating time, number of remastications, and remasticating time decreased (p<0,05) with intravenous IPA infusion. The IPA concentrations and VFA concentrations increased in the blood circulation. Our data suggest that sensitive receptors of rumination to IPA are more likely to be in an area such as the brain stem where they can respond to blood metabolite levels.

PITCH EXTRACTION USING AN APPROXIMATELY IDEAL LOW-PASS FILTER

T. Matsuoka,A. Sugama,E. Onodera,Y. Ishida 한국소음진동공학회 1994 한국소음진동공학회 국제학술대회논문집 Vol.1994 No.4

Effects of Intraruminal versus Intravenous Infusions of Acetone on the Ruminating and Masticating Behavior of Goats

Asato, N.,Hirayama, T.,Higa, T.,Onodera, R.,Shinjo, A.,Oshiro, S. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.2

Acetone, which is produced from butyric acid when it passes through the rumen wall, was infused into the rumen and jugular veins of three female goats to investigate the role of acetone in ruminating and masticating behavior. The ruminating behavior, as measured by the number of boli and the ruminating time, decreased (p<0.05) with intraruminal acetone infusion. However, the ruminating behavior did not change significantly in response to intravenous acetone infusion. Feed intake significantly decreased with intraruminal acetone infusion, but not with intravenous acetone infusion. The concentrations of acetone in the plasma increased significantly (p<0.05) with both acetone infusion regions. Ruminal fluid acetone, and isopropyl alcohol (IPA), which is one of the ketone bodies, produced from acetone by bacterial action in rumen, concentrations were significantly increased (p<0.05) with both acetone infusion regions. These results suggest that the chemoreceptors sensitive to acetone are more likely to be in the rumen epithelium, portal system, or liver, where they can respond to acetone levels.

Effects of Intraruminal Isopropyl Alcohol Infusions on the Ruminating Behavior of Goats

Asato, N.,Hirata, T.,Hirayama, T.,Onodera, R.,Shinjo, A.,Oshiro, S. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.8

Isopropyl alcohol (IPA), produced from acetone by rumen bacterial action, was infused into the rumen of three female goats kept in a climatically controlled experimental room during feeding to investigate the mechanism and roles of IPA in ruminating behavior (number of boli and ruminating time). The ruminating behavior measured by the number of boli, ruminating time, number of remastications, and remasticating time increased (p<0.05) with intraruminal IPA infusion. The concentrations of IPA and acetone in the rumen and the plasma significantly increased (p<0.05) during intraruminal IPA infusion. These data suggest that rumination receptors sensitive to IPA and acetone may be in an area such as the rumen epithelium and the brain stem where they can respond to metabolite levels.