144,672 research outputs found
Y. Imai
No full textImai is sitting at a lab bench with several pieces of lab equipment and a lab notebook.Inscriptions on image and/or album page: "Y. Imai/1928"Digitized by: MBLWHOI Libraryimage/jpg black and white image reformatted digitalPhotograph
Fast cryptanalysis of the Matsumoto-Imai public key scheme
No full textThe Matsumoto-Imai public key scheme was developed to provide very fast signatures. It is based on substitution polynomials over GF ( 2 m). This paper shows in two ways that the Matsumoto-Imai public key scheme is very easy to break. In the faster of the two attacks the time to cryptanalyze the scheme is about proportional to the binary length of the public key. This shows that Matsumoto and Imai greatl
Identification of sirm, a novel insulin-regulated SH3 binding protein that associates with Grb-2 and FYN.
No full textWe have previously developed a mouse model of insulin-resistant diabetes by targeted inactivation of the insulin receptor gene. During studies of gene expression in livers of insulin receptor-deficient mice, we identified a novel cDNA, which me have termed sirm (Son of Insulin Receptor Mutant mice), sirm is largely, albeit not exclusively, expressed in insulin-responsive tissues, Insulin is a potent modulator of sirm expression, and sirm mRNA levels correlate with tissue sensitivity to insulin. The product of the sirm gene is a serine/threonine-rich protein with several proline-rich motifs and an NPNY motif, conforming to the consensus sequence recognized by the phosphotyrosine binding domains of insulin receptor substrate and Shc proteins, However, Sirm bears no extended homologies with other known proteins. Based on the sequences of the proline-rich domains, we sought to determine whether Sirm binds to the SH3 domains of FYN and Grb-8, We demonstrate here that Sirm binds to FYN and Grb-8 in 3TS-L1 adipocytes and that insulin treatment results in the dissociation of the Sirm FYN and Sirm-Grb-2 complexes. We also show that Sirm is a substrate for the kinase activity of FYN in vitro, Based on the patterns of expression of sirm, its regulation by insulin, and the interactions with molecules in the insulin signaling pathway, we surmise that Sirm plays a role in modulating tissue sensitivity to insulin
New evidence on the Early Cretaceous Fossil Avifauna in the eastern margin of Asia from the Kitadani Formation of the Tetori Group
No full text博士論文本文Full 以下に掲載：CHAPTER 3: Memoir of the Fukui Prefectural Dinosaur Museum 17(1) pp.1-8 2018. Fukui Prefectural Dinosar Museum. 共著者：Imai, T., Y. Tsukiji, Y. Azuma CHAPTER 4: Historical Biology 27(8) pp.1090-1097 2014. Taylor & Francis. 共著者：Imai, T., Y. Azum
Expression of variant forms of insulin receptor substrate-1 identified in patients with noninsulin-dependent diabetes mellitus
No full textSeveral polymorphisms have been identified in the amino acid sequence of human insulin receptor substrate-1 (IRS-1). Some of the variant sequences have been reported to be increased in prevalence among patients with noninsulin-dependent diabetes mellitus (NIDDM). This observation led to the hypothesis that these amino acid substitutions may impair the function of IRS-1, thereby causing the insulin resistance seen in patients with NIDDM. To address this question, we have designed studies to evaluate the effects of three variant sequences identified in our laboratory: Gly(819)-->Arg, Gly(972)-->Arg, and Arg(1221)-->Cys. We constructed four IRS-1 expression vectors for transfection in COS-7 cells: wild-type, single mutant (Gly(819)-->Arg), double mutant (Gly(819)-->Arg; Gly(972)-->Arg), and triple mutant (Glys(819)-->Arg; Gly(972)-->Arg; Arg(1221)-->Cys) IRS-1. The mutations did not alter the level of expression or the extent of insulin receptor-mediated tyrosine phosphorylation of recombinant IRS-1. Moreover, the mutations did not lead to a detectable impairment in the association of recombinant IRS-1 with important downstream effecters, including the p85 subunit of phosphatidylinositol 3-kinase and growth factor receptor-binding protein-2. We conclude that these amino acid substitutions do not appear to cause a major defect in the function of IRS-1, as judged by our assays. However, this type of assay probably lacks the sensitivity to detect subtle functional defects. In light of the suggestive associations observed in epidemiological studies, it is premature to totally discard the hypothesis that variant sequences of IRS-1 may contribute to the pathogenesis of NIDDM. Nevertheless, our studies cannot be interpreted as lending support to that hypothesis
Comparative Primate Molecular Cytogenetics: Revealing Ancestral Genomes, Marker Order and Evolutionary New Centromeres
No full textOn the transformation of austentite to martensite and tempering process of martensite in iron-nitrogen system
No full textThe transformation of austenite to martensite and the tempering of martensite in iron-carbon system, have been investigated by several workers but very few studies have related to the problem in iron-nitrogen system, inspite of the fact that both nitrogen and carbon have similar atomic volumes and that a forced interstitial solid solution is formed in iron. In the present work the authors have studied the transformation of austenite to martensite based on statistical thermodynamics and crystallography using Fe-N alloys, and have compared the results to those Fe-N alloys, and have compared the results to those obtained with Fe-C alloys. Studies on tempering of martensite and austenite in Fe-N alloys were carried out by X-ray diffraction analysis. (Prof. Y. Imai, Messrs M. Izumiyama and M. Tsuchiya Metallurgical Research Institute, Tohuku University, Japan
Spatially-localized time dependent solutions including turbulence and their interactions in 2D Kolmogorov flow
No full textIn 2D Kolmogorov flow in small aspect ratio domains, spatially-localized solutions such as kink, traveling or time-dependent kink-antikink pars coexist. However, the conservation of the flow rate in the y direction strongly restrict combination of localized solutions and their positioning. We find that by adding a homogeneous flow U y their positioning is controlled and each of localized solutions including a spatially-localized chaos is isolated. Numerical results suggest that these isolated solutions can be elements constructing a whole flow
Characteristics of overlap region in high-Reynolds number turbulent channel flow
No full textDirect numerical simulation of the fully developed turbulent channel flows have been carried out at the Reynolds number based on the friction velocity and the channel half width, 2000, 4000 and 8000. A hybrid 10th order accurate finite difference scheme in the stream and spanwise directions, and a second-order scheme in the wall-normal direction is adapted as the spatial discretization method. We observed the plateau profiles in the indicator function corresponded to the von Karman constant. Furthermore, second peak of streamwise pre-multiplied spectra were appeared in the same wall normal height, 300 < y+ < 600, in case of Re = 4000. Nevertheless, the effects of the lager than the channel half height scale on the streamwise turbulent intensity are fixed contributions without dependence on Reynolds number. These results suggested that the new streamwise vortexes are formed between buffer layer and outer layer with increasing of Reynolds number
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