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2,032 results on '"KATAYAMA, I."'

51. Permeability profiles across the crust-mantle sections in the Oman Drilling Project inferred from dry and wet resistivity data

Author

Katayama, I., Abe, N., Hatakeyama, K., Akamatsu, Y., Okazaki, K., Ulven, O. I., Hong, G., Zhu, W., Cordonnier, B., Michibayashi, K., Godard, M., Kelemen, P., the Oman Drilling Project Phase, 2 Science Party, Crispini, Laura, Hiroshima University, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), University of Oslo (UiO), Seoul National University [Seoul] (SNU), University of Maryland [College Park], University of Maryland System, Nagoya University, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Lamont-Doherty Earth Observatory (LDEO), and Columbia University [New York]

Subjects
010504 meteorology & atmospheric sciences, Gabbro, Oman, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Mineralogy, Drilling, Crust, Ophiolite, 01 natural sciences, oceanic lithosphere, Mantle (geology), resistivity, Geophysics, serpentinite, Space and Planetary Science, Geochemistry and Petrology, Electrical resistivity and conductivity, ophiolite, Transition zone, Earth and Planetary Sciences (miscellaneous), permeability, Porosity, Geology, 0105 earth and related environmental sciences
Abstract

International audience; Permeability profiles in the crust‐mantle sequences of the Samail ophiolite were constructed based on onboard measurements of the electrical resistivity of cores recovered during the Oman Drilling Project. For each sample, we measured dry and brine‐saturated resistivity during the description campaign on the drilling vessel Chikyu. Owing to the conductive brine in the pore space, wet resistivity is systematically lower than dry resistivity. The difference between dry and wet resistivity is attributed to the movement of dissolved ions in brine that occupies the pore space. We applied effective medium theory to calculate the volume fraction of pores that contribute to electrical transport. Using an empirical cubic law between transport porosity and permeability, we constructed permeability profiles for the crust‐mantle transition zone and the serpentinized mantle sections in the Samail ophiolite. The results indicate that (1) the gabbro sequence has a markedly lower permeability than the underlying mantle sequence; (2) serpentinized dunites have higher permeability than serpentinized harzburgites; and (3) discrete sample permeability is correlated with ultrasonic velocity, suggesting that the permeability variations predominately reflect crack density and geometry.

Published
2020

54. Genome-wide association study identifies CDH13 as a susceptibility gene for rhododendrol-induced leukoderma.

Author

Okamura, K, Abe, Y, Naka, I, Ohashi, J, Yagami, A, Matsunaga, K, Kobayashi, Y, Fukai, K, Tanemura, A, Katayama, I, Masui, Y, Ito, A, Yamashita, T, Nagai, H, Nishigori, C, Oiso, N, Aoyama, Y, Araki, Y, Saito, T, Hayashi, M, Hozumi, Y, Suzuki, T, Okamura, K, Abe, Y, Naka, I, Ohashi, J, Yagami, A, Matsunaga, K, Kobayashi, Y, Fukai, K, Tanemura, A, Katayama, I, Masui, Y, Ito, A, Yamashita, T, Nagai, H, Nishigori, C, Oiso, N, Aoyama, Y, Araki, Y, Saito, T, Hayashi, M, Hozumi, Y, and Suzuki, T

Abstract

Racemic RS-4-(4-hydroxyphenyl)-2-butanol (rhododendrol; trade name: Rhododenol [RD]), which is used in topical skin-lightening cosmetics, was unexpectedly reported in Japan to induce leukoderma or vitiligo called RD-induced leukoderma (RIL) after repeated application. To our knowledge, no studies have investigated chemical-induced vitiligo pathogenesis on a genome-wide scale. Here, we conducted a genome-wide association study (GWAS) for 147 cases and 112 controls. CDH13, encoding a glycosylphosphatidylinositol-anchored protein called T-cadherin (T-cad), was identified as the strongest RIL susceptibility gene. RD sensitivity was remarkably increased by T-cad knockdown in cultured normal human melanocytes. Furthermore, we confirmed tyrosinase upregulation and downregulation of the anti-apoptotic molecules (BCL-2 and BCL-XL), suggesting that T-cad is associated with RD via tyrosinase or apoptotic pathway regulation. Finally, monobenzyl ether of hydroquinone sensitivity also tended to increase with T-cad knockdown, suggesting that the T-cad could be a candidate susceptibility gene for RIL and other chemical-induced vitiligo forms. This is the first GWAS for chemical-induced vitiligo, and it could be a useful model for studying the disease's genetic aspects.

Published
2020

65. Crack geometry of serpentinized peridotites inferred from onboard ultrasonic data from the Oman Drilling Project

Author

Katayama, I., Abe, N., Okazaki, K., Hatakeyama, K., Akamatsu, Y., Michibayashi, K., Godard, M., Kelemen, P., The Oman Drilling Project Phase, 2 Science Party (include Laura Crispini), Crispini, Laura, Department of Earth and Planetary Systems Science [Hiroshima], Hiroshima University, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kochi Institute for Core Sample Research, Graduate School of Environmental Studies [Nagoya], Nagoya University, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), Lamont-Doherty Earth Observatory (LDEO), and Columbia University [New York]

Subjects
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, Crack, 010504 meteorology & atmospheric sciences, Elastic wave velocity, Mantle hydration, Oman Drilling Project, Serpentinite, Borehole, Drilling, Geometry, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Matrix (geology), Geophysics, Lithosphere, Electrical resistivity and conductivity, Ultrasonic sensor, Porosity, Elastic modulus, Geology, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract

International audience; To assess the geometry of cracks in highly altered peridotites, we analyzed the ultrasonic velocity of serpentinized dunites and harzburgites collected by the Oman Drilling Project (Holes BA1B, 3A, and 4A). First, we estimated the hydrated fraction from grain density to obtain the porosity-free matrix velocity, which indicated complete serpentinization at shallow depths and decreasing hydration at greater depths. We assume that the difference between the solid matrix and measured onboard ultrasonic velocity is attributed to cracks with a spheroidal shape in the samples. Application of the effective medium theory to onboard data, such as P-wave velocity and porosity, indicates that the average pore aspect ratio is mostly between 0.1 and 0.01, and crack density varies from 0.58 to 0.02. We found a positive relationship between aspect ratio and hydrated fraction, suggesting a change in crack shape related to dissolution-precipitation processes during hydration. The relatively high aspect ratio and hence high fluid flux at shallow depths are also consistent with the onboard resistivity data and present-day hydration processes inferred from the borehole fluid chemistry. The inversion of ultrasonic data provides a series of elastic moduli that can be used to make a rough approximation of Poisson's ratio from the onboard data, which is a key physical property for interpreting geophysical observations in the oceanic lithosphere.

Published
2021

69. Gated multiple-sampling and tracking proportional chamber: New detector system for nuclear astrophysical study with radioactive nuclear beams

Author

Hashimoto, T., Ishiyama, H., Ishikawa, T., Kawamura, T., Nakai, K., Watanabe, Y.X., Miyatake, H., Tanaka, M.H., Fuchi, Y., Yoshikawa, N., Jeong, S.C., Katayama, I., Nomura, T., Furukawa, T., Mitsuoka, S., Nishio, K., Matsuda, M., Ikezoe, H., Fukuda, T., Das, S.K., Saha, P.K., Mizoi, Y., Komatsubara, T., Yamaguchi, M., and Tagishi, Y.

Published
2006
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87. Present-day ultrahigh-pressure conditions of coesite inclusions in zircon and garnet: Evidence from laser Raman microspectroscopy

Author

Parkinson, C.D. and Katayama, I.

Subjects
Asia -- Natural history, Precious stones -- Inclusions, Rocks, Metamorphic -- Inclusions, Zircon -- Environmental aspects, Garnet -- Environmental aspects, Earth sciences
Abstract

Coesite (the dense, high-pressure polymorph of quartz) occurs as inclusions in mechanically strong minerals in deeply subducted, metamorphosed crustal rocks in a number of Eurasian collisional orogens. It is the primary indicator mineral of ultrahigh-pressure (P) metamorphism. Whereas some coesite inclusions are untransformed, most exhibit partial transformation to palisade quartz and a concomitant increase in volume (resulting in rupture and radial fracturing of the host grain). Coesite can be identified by its diagnostic Raman spectrum; the strongest band (at atmospheric pressure, room temperature) is at 521 cm(super -l). Laser Raman microspectroscopic analyses of coesite inclusions within garnet and zircon in ultrahigh-P metamorphic rocks from Kazakhstan, Indonesia, and China reveal consistent differences in the Raman spectra of (1) partially transformed coesite + quartz (main Raman band at 521 cm(super -1)) and (2) untransformed monomineralic coesite grains (main band at 525-526 cm(super -1)). Applying the room-temperature calibration of pressure dependence of the coesite Raman spectrum, we conclude that the latter coesite inclusions are subject to a remarkable pressure differential of 19-23 kbar with the host grains, and are still undergoing pressure-temperature conditions on or close to the quartz-coesite equilibrium boundary.

Published
1999

100. What is the origin of macroscopic friction?

Author

Sakuma, H., Kawai, K., Katayama, I., and Suehara, S.

Subjects
Multidisciplinary, Materials science, 010504 meteorology & atmospheric sciences, Materials Science, SciAdv r-articles, Mechanics, Surface finish, 010502 geochemistry & geophysics, 01 natural sciences, Potential energy, Shear (geology), Density functional theory, Mica, Computer Science::Databases, Research Articles, Research Article, 0105 earth and related environmental sciences
Abstract

The origin of macroscopic friction can be explained by the roughness of the potential energy surface of sliding planes., What is the origin of molecular friction, and how can macroscopic friction be explained in terms of molecular friction? To elucidate the origins of molecular and macroscopic friction, we conducted density functional theory calculations and double-direct shear tests at normal stresses ranging from 5 to 60 MPa for mica surfaces. Frictional forces between mica surfaces were theoretically predicted to oscillate periodically every 30° of sliding direction, in agreement with previous experimental findings. This result affirms that the potential energy roughness of mica under sliding is the origin of molecular friction, which depends on the normal stress and sliding direction. The discovered mechanism of molecular friction can quantitatively explain experimentally observed macroscopic friction of mica when the presence of wear particles is taken into consideration.

Published
2018

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