著者

斎藤 伸治 SAITO Shinji

出版者

岩手大学人文社会科学部欧米言語文化コース

雑誌

欧米言語文化論集

巻号頁・発行日

pp.119-135, 2012-02-07 (Released:2016-05-18)

著者

Kim Kang Miyazaki Kunimasa Saito Shinji

出版者

IOP Publishing

雑誌

Journal of physics. Condensed matter (ISSN:09538984)

巻号頁・発行日

vol.23, no.23, pp.234123, 2011-05

被引用文献数

40 26

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Using molecular dynamics simulations, we study the slow dynamics of supercooled liquidsconfined in a random matrix of immobile obstacles. We study the dynamical crossover fromglass-like to Lorentz-gas-like behavior in terms of the density correlation function, the meansquare displacement, the nonlinear dynamic susceptibility, the non-Gaussian parameter, and thefragility. We find the cooperative and spatially heterogeneous dynamics to be suppressed as theobstacle density increases, leading to a more Arrhenius-like behavior in the temperaturedependence of the relaxation time. Our findings are qualitatively consistent with the results ofrecent experimental and numerical studies for various classes of spatially heterogeneoussystems. We also investigate the dependence of the dynamics of mobile particles on theprotocol used to generate the random matrix. A re-entrant transition from the arrested phase tothe liquid phase as the mobile particle density increases is observed for a class of protocols.This re-entrance is explained in terms of the distribution of the volume of the voids that areavailable to the mobile particles.

著者

Tsai Melody Ohniwa Ryosuke L Kato Yusuke Takeshita Sayaka L Ohta Toshiko Saito Shinji Hayashi Hideo Morikawa Kazuya

出版者

BioMed Central

雑誌

BMC microbiology (ISSN:14712180)

巻号頁・発行日

vol.11, pp.13, 2011-01

被引用文献数

100 26

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BackgroundThe ability of staphylococci to grow in a wide range of salt concentrations is well documented. In this study, we aimed to clarify the role of cardiolipin (CL) in the adaptation of Staphylococcus aureus to high salinity.ResultsUsing an improved extraction method, the analysis of phospholipid composition suggested that CL levels increased slightly toward stationary phase, but that this was not induced by high salinity. Deletion of the two CL synthase genes, SA1155 (cls1) and SA1891 (cls2), abolished CL synthesis. The cls2 gene encoded the dominant CL synthase. In a cls2 deletion mutant, Cls1 functioned under stress conditions, including high salinity. Using these mutants, CL was shown to be unnecessary for growth in either basal or high-salt conditions, but it was critical for prolonged survival in high-salt conditions and for generation of the L-form.ConclusionsCL is not essential for S. aureus growth under conditions of high salinity, but is necessary for survival under prolonged high-salt stress and for the generation of L-form variants.

著者

斎藤 伸治 SAITO Shinji

出版者

岩手大学人文社会科学部

雑誌

言語と文化・文学の諸相

巻号頁・発行日

pp.199-215, 2008-03-21

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現代言語学の祖とされるソシュールは,古代ギリシア以来ずっと支配的だった言語に対する1つの見方・問題意識を,無意味なもの,言語の本質を捉え損なうものとして退けたということが言われる(丸山(1981), Harris andTaylor(1989)などを参照)。このソシュール以前の西洋の言語に対する見方というのは,ソシュールの言葉を用いれば, 「名称目録的言語観」(nomenclaturism)というものであり,平たく言えば「言葉とは本質的に事物を名指すものであり,その事物は言葉とは独立に存在している」という言語観であった。西洋における最初の本格的な言語論であるプラトンの『クラテュロス』篇(伝統的な副題は「名前の正しさについて」)は,この言葉と事物との間の関係が自然的なものかあるいは人間社会の側の慣習にすぎないものかについて論じたものであり,この書以来ずっと,言語とはまず基本的に外界のものを名指すものであるという言語観が,西洋の思想界を支配してきたということになる。