Development of un-irradiated and un-spiked laser fusion K-Ar dating for single grain minerals (2nd report)

A laser fusion K-Ar dating has been developed as an in-situ micro measurement of radiometric ages applicable for less-abundant minerals found on thin sections [1, 2]. Strong induced radio-activities in Fe-rich minerals by neutron irradiation prohibits collecting sufficient amount of mineral separates, which partly limits applications of Ar-Ar method[3]. Nonetheless, once K-Ar method establish for a single grain mineral containing trace K with <0.1 wt%, much wider applications are anticipated, e.g. fine minerals of hydrothermal origin. Thus, we have installed a laser fusion apparatus to GVI-5400He noble gas mass spectrometer of JAMSTEC, as a part of the TAIGA-project: Grant-in-aid for Scientific Research on Innovative Areas. Quantitative determination of K for trace concentration, approx. 0.1wt%, using EPMA sometimes faces poor accuracy and/or precision for a requirement of accurate dating. Thus we have been tested single grain K measurement under a low blank protocol using graphite furnace atomizer to ensure high sensitivities. This K measurement follows a laser fusion Ar measurement applied to the retrieved single melted mineral grain itself. An accurate K-Ar age determination requireds complete retrieval both K and radiogenic Ar. Thus, conditions laser irradiation and K quantitation have investigated using SORI-93 K-Ar standard [4]. Our preliminary results show a 15% older averaged age with more than 10% deviation for recommended age for SORI-93 (92.6+/-0.6Ma, [4]), which is still under investigation. [1] Sato et al. (2008) Chikyukagaku, 42, 179-199. [2] Sato et al. (2011) JpGU annual meeting 2011. [3] Ishibashi et al. (2009) J. Geogr., 118, 1186-1204. [4] Sudo et al. (1998) Geochemical J., 32, 49-58.SGL43-P02ポスター要旨 / 日本地球惑星科学連合2012年大会（2012年5月20日～5月25日, 幕張メッセ国際会議場） / 日本惑星科学連合の許諾に基づき本文ファイルを掲

Circular Dichroism of Optically Active Poly(dialkylsilane) Aggregates in Microcapsules

Terao K., Kikuchi N., Sato S., et al. Circular Dichroism of Optically Active Poly(dialkylsilane) Aggregates in Microcapsules. Langmuir, 22(19), 7975-7980, August 10, 2006. Copyright © 2006, American Chemical Society. https://doi.org/10.1021/la060810+

ネコ皮質視覚野ニューロンの活動性に対するコリン投射系破壊の効果

H. Sato, Y. Hata, K. Hagihara, and T. Tsumoto, "Effects of cholinergic depletion on neuron activities in the cat visual cortex," Journal of Neurophysiology, 58:4, pp.781-794, 1987. https://doi.org/10.1152/jn.1987.58.4.78

Coupled-channel study of gamma p --> K+ Lambda

A coupled-channel (CC) approach has been developed to investigate kaon photoproduction on the nucleon. In addition to direct K+ Lambda production, our CC approach accounts for strangeness production including K+ Lambda final state interactions with both pi0 p and pi+ n intermediate states. Calculations for the gamma p --> K+ Lambda reaction have been performed, and compared with the recent data from SAPHIR, with emphasis on the CC effects. We show that the CC effects are significant at the level of inducing 20% changes on total cross sections; thereby, demonstrating the need to include pi N channels to correctly describe the gamma p --> K+ Lambda reaction.Comment: 12 pages, 6 eps figures, uses elsart.cls, submitted to Phys.Lett.B; v2: added paragraph in section

Dynamical coupled-channel study of K+ Lambda photoproduction

Results for the reaction gamma p --> K+ Lambda, studied within a constituent quark model and a dynamical coupled-channel approach, are presented and compared with recent data. Issues related to the search for missing baryon resonances are briefly discussed and the role played by a third S_{11} resonance is underlined.Comment: To appear in the proceedings of BARYONS 2004, Palaiseau, France, 25-29 Oct 200

Vitamin K catabolite inhibition of ovariectomy-induced bone loss: Structure–activity relationship considerations

The potential benefit of vitamin K as a therapeutic in osteoporosis is controversial and the vitamin K regimen being used clinically (45 mg/day) employs doses that are many times higher than required to ensure maximal gamma‐carboxylation of the vitamin K‐dependent bone proteins. We therefore tested the hypothesis that vitamin K catabolites, 5‐carbon (CAN5C) and 7‐carbon carboxylic acid (CAN7C) aliphatic side‐chain derivatives of the naphthoquinone moiety exert an osteotrophic role consistent with the treatment of osteoporosis

Photoinduced Magnetization in a Thin Fe-CN-Co Film

The magnetization of a thin Fe-Co cyanide film has been investigated from 5 K to 300 K and in fields up to 500 G. Upon illumination with visible light, the magnetization of the film rapidly increases. The original cluster glass behavior is further developed in the photoinduced state and shows substantial changes in critical temperature and freezing temperature.Comment: 2 pages, 2 figures, 1 table, International Conference on Magnetism 200