276 research outputs found
Geodetic inversion for spatial distribution of slip under smoothness, discontinuity, and sparsity constraints
Maximum tsunami height prediction using pressure gauge data by a Gaussian process at Owase in the Kii Peninsula, Japan
We constructed a model to predict the maximum tsunami height by a Gaussian process (GP) that uses pressure gauge data from the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) in the Nankai trough. We found a greatly improved generalization error of the maximum tsunami height by our prediction model. The error is about one third of that by a previous method, which tends to make larger predictions, especially for large tsunami heights (>10 m). These results indicate that GP enables us to get a more accurate prediction of tsunami height by using pressure gauge data
L-Lysine production independent of the oxidative pentose phosphate pathway by Corynebacterium glutamicum with the Streptococcus mutans gapN gene
Published online 29 March 2016We have recently developed a Corynebacterium glutamicum strain that generates NADPH via the glycolytic pathway by replacing endogenous NAD-dependent glyceraldehyde 3-phosphate dehydrogenase (GapA) with a nonphosphorylating NADP-dependent glyceraldehyde 3-phosphate dehydrogenase (GapN) from Streptococcus mutans. Strain RE2, a suppressor mutant spontaneously isolated for its improved growth on glucose from the engineered strain, was proven to be a high-potential host for l-lysine production (Takeno et al., 2010). In this study, the suppressor mutation was identified to be a point mutation in rho encoding the transcription termination factor Rho. Strain RE2 still showed retarded growth despite the mutation rho696. Our strategy for reconciling improved growth with a high level of l-lysine production was to use GapA together with GapN only in the early growth phase, and subsequently shift this combination-type glycolysis to one that depends only on GapN in the rest of the growth phase. To achieve this, we expressed gapA under the myo-inositol-inducible promoter of iolT1 encoding a myo-inositol transporter in strain RE2. The resulting strain RE2Aiol was engineered into an l-lysine producer by introduction of a plasmid carrying the desensitized lysC, followed by examination for culture conditions with myo-inositol supplementation. We found that as a higher concentration of myo-inositol was added to the seed culture, the following fermentation period became shorter while maintaining a high level of l-lysine production. This finally reached a fermentation period comparable to that of the control GapA strain, and yielded a 1.5-fold higher production rate compared with strain RE2. The transcript level of gapA, as well as the GapA activity, in the early growth phase increased in proportion to the myo-inositol concentration and then fell to low levels in the subsequent growth phase, indicating that improved growth was a result of increased GapA activity, especially in the early growth phase. Moreover, blockade of the pentose phosphate pathway through a defect in glucose 6-phosphate dehydrogenase did not significantly affect l-lysine production in the engineered GapN strains, while a drastic decrease in l-lysine production was observed for the control GapA strain. Determination of the intracellular NADPH/NADP+ ratios revealed that the ratios in the engineered strains were significantly higher than the ratio of the control GapA strain irrespective of the pentose phosphate pathway. These results demonstrate that our strain engineering strategy allows efficient l-lysine production independent of the oxidative pentose phosphate pathway.ArticleMETABOLIC ENGINEERING. 37:1-10 (2016)journal articl
A nonlinear parametric model based on a power law relationship for predicting the coastal tsunami height
When a subduction-zone earthquake occurs, the tsunami height must be predicted to cope with the damage generated by the tsunami. Therefore, tsunami height prediction methods have been studied using simulation data acquired by large-scale calculations. In this research, we consider the existence of a nonlinear power law relationship between the water pressure gauge data observed by the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) and the coastal tsunami height. Using this relationship, we propose a nonlinear parametric model and conduct a prediction experiment to compare the accuracy of the proposed method with those of previous methods and implement particular improvements to the extrapolation accuracy
Effects of ultradian variation on smoking behavior
The purpose of this study is to examine the enhancement model of smoking maintenance, which has been proposed by Mangan & Golding (1978). We studied the relationships of the ultradian variations among the smoking behavior and sleepiness. The results were as follows. (1) The results of the time series analysis revealed that several spectral peaks were obtained in day time fluctuations of smoking behavior, sleepiness, mood and task performance. The average peak frequency for each parameter distributed in the range of 10 to 14 cycle/day (c/d : See Fig. 3-6). (2) The significant correlations were obtained between the parameters of the smoking behavior (frequency of puffing and VAS score of need for smoking) and the daytime sleepiness (VAS score). The significant average correlation coefficients between smoking need and sleepiness were observed (See Table 2). In general, present results agree with the enhancement model of smoking maintenance
Ambient dose rate in Mikurashima Island after the Fukushima Daiichi Nuclear Power Plant accident
No detailed ambient dose rate has been reported, either before or after the Fukushima Daiichi Nuclear Power Plant (F1-NPP) accident, for Mikurashima Island, one of the islands within the authority of the Tokyo Metropolitan Government. Thus, the ambient dose rate on Mikurashima Island was observed 4.5 years after the F1-NPP accident. A car-borne survey and a foot patrol survey of the ambient dose rates were conducted over the entire island using a 3-in × 3-in NaI(Tl) scintillation spectrometer. The average ambient dose rate was 27 nGy h^-1 (12 – 45 nGy h^-1) and a higher dose distribution was observed for the northern and eastern areas of Mikurashima Island. However, the impact from the F1-NPP accident (i.e., the presence of artificial radionuclides) was mainly observed for the mountain area of the island (4 – 9 nGy h^-1; located about the center to south-southeast direction). Based on the measured ambient dose rate, the estimated annual effective dose after the accident was 0.09 mSv y^-1
<Abstract of annual report>Synthesis and Thermal Reaction of Cyano-Stabilized Cyclic Sulfur Ylides, 2-Alkyl-1-cyano-3,4-dihydro-1H-2-thionianaphthalen-1-ides.
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