The University of TokyoTokyo

Medicine, Japan

The University of TokyoTokyo

Medicine, Japan

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Yamaya Y.,Japan National Institute of Advanced Industrial Science and Technology | Mogi T.,Hokkaido University | Honda R.,Prediction Institute | Hase H.,Geothermal Energy Research & Development Co. | And 2 more authors.
Geochemistry, Geophysics, Geosystems | Year: 2017

The Ishikari Lowland on the island of Hokkaido in northeastern Japan is situated at the end of a westward-moving foreland fold-and-thrust belt from the Hidaka collision zone, where the northeastern Japan and Kurile arcs meet. This activity forms a tectonic zone under an east-west compression field in this region. A magnetotelluric resistivity survey was performed to investigate the mechanism for the strain concentration in this region. A three-dimensional (3-D) resistivity inversion showed a conductive thick sedimentary layer and an underlying resistive basement. Remarkable conductors were found in the resistive basement beneath the Ishikari-teichi-toen fault zone (ITFZ) and the Shikotsu caldera. The conductors beneath the ITFZ were interpreted as aqueous fluids that accumulated in the damaged zone in connection with the formation of pull-apart faults and horst. In contrast, the conductor beneath the Shikotsu caldera corresponds to a magmatic fluid path from the upper mantle. These features suggest that the ductile deformation in the upper crust contribute to the strain concentration in this region. The soft thick sediments allow ductile deformations to occur. Furthermore, local fluid-rich zones in the basement cause the crustal strength to be heterogeneous. These thick sediments and local fluids in the basement both contribute to the strain concentration in this region. © 2017. American Geophysical Union. All Rights Reserved.

Inuzuka R.,The University of TokyoTokyo | Kuwata S.,Saitama University | Kurishima C.,Saitama University | Liang F.,Shanghai JiaoTong University | And 3 more authors.
Circulation Journal | Year: 2015

Background: The myocardial performance index (MPI) has emerged as a Doppler-derived index for global ventricular function capable of estimating combined systolic and diastolic performance. While several studies have reported its load-dependency, responses of the MPI to various hemodynamic changes have not been fully characterized. Methods and Results: The response characteristics of the MPI were examined and compared with ejection fractions (EF) by changing hemodynamic parameters within the physiological range in a lumped parameter model of the cardiovascular system. At baseline, the MPI was 0.42 and the EF was 0.68. Heart rate increase resulted in a decrease in EF and an increase in the MPI. Reduction in end-systolic elastance decreased EF and increased the MPI. Volume overload and ventricular stiffening did not affect EF but paradoxically reduced the MPI. Increased afterload due to higher systemic resistance resulted in a decrease in EF and increase in the MPI, but afterload increase caused by reduced arterial compliance led to a decrease in both EF and MPI. These MPI characteristics caused paradoxical improvement of the MPI during disease progression of chronic heart failure in a simulation of mitral regurgitation. Conclusions: The MPI is affected by a wider variety of hemodynamic parameters than EF. In addition, it is predicted to decrease paradoxically with volume overload, reduction in arterial compliance, or ventricular diastolic stiffening. These MPI characteristics should be considered when assessing cardiovascular dynamics using this index. © 2016, Japanese Circulation Society. All rights reserved.

PubMed | Japan National Institute of Infectious Diseases and The University of TokyoTokyo
Type: | Journal: Frontiers in microbiology | Year: 2016

Neutralizing antibody (NAb) responses are promising immune effectors for control of human immunodeficiency virus (HIV) infection. Protective activity and mechanisms of immunodeficiency virus-specific NAbs have been increasingly scrutinized in animals infected with simian immunodeficiency virus (SIV), chimeric simian/human immunodeficiency virus (SHIV) and related viruses. Studies on such models have unraveled a previously underscored protective potential against

Konishi S.,The University of TokyoTokyo | Konishi S.,University of Washington | O'Connor K.A.,University of Washington
American Journal of Human Biology | Year: 2016

Objectives: Elevated and suppressed concentrations of cortisol have been linked with less favorable metabolic biomarkers, such as elevated lipids and glycosylated hemoglobin (HbA1c). Based on recent work reporting that some individuals secrete more cortisol into saliva (high saliva-to-blood cortisol ratio; high secretors) than others after correcting for blood cortisol concentrations, our objectives were to examine (1) whether lipids and glycosylated hemoglobin varied across cortisol and salivary secretor status; and (2) if blood and saliva provide the same results with respect to metabolic markers. Methods: Matched saliva and dried blood spot (DBS) specimens collected once a week for four weeks (N = 48 healthy women, 192 specimens) were assayed for cortisol. Fasting blood specimens collected once from each woman were quantified for cholesterol (total, HDL, LDL), triglycerides and HbA1c. Results: Low salivary cortisol secretors showed significantly higher triglyceride and HbA1c compared to high-secretors (P<0.05; t-test). The only significant correlation with mean blood or salivary cortisol concentration was a negative correlation between salivary cortisol and HbA1c (P = 0.021, r = −0.333). Conclusions: Triglycerides, HDL, and especially HbA1c were associated with salivary cortisol secretor status but not with DBS cortisol concentrations. These results suggest that blood and saliva cortisol measures might provide different health outcome information, and that salivary cortisol secretor status may provide additional information on health status. Am. J. Hum. Biol. 28:539–544, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Iwata Y.,The University of TokyoTokyo | Yoshida Y.,Preferred Infrastructure
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In this paper, we introduce a methodology, called decompositionbased reductions, for showing the equivalence among various problems of bounded-width. First, we show that the following are equivalent for any α > 0: – SAT can be solved in O∗ (2αtw) time, – 3-SAT can be solved in O∗ (2αtw) time, – Max 2-SAT can be solved in O∗(2αtw) time, – Independent Set can be solved in O∗(2αtw) time, and – Independent Set can be solved in O∗ (2αcw) time, where tw and cw are the tree-width and clique-width of the instance, respectively. Then, we introduce a new parameterized complexity class EPNL, which includes Set Cover and TSP, and show that SAT, 3-SAT, Max 2-SAT, and Independent Set parameterized by path-width are EPNLcomplete. This implies that if one of these EPNL-complete problems can be solved in O∗ (ck) time, then any problem in EPNL can be solved in O∗(ck) time. © Springer-Verlag Berlin Heidelberg 2015

Takatori S.,The University of TokyoTokyo | Fujimoto T.,Nagoya University
Communicative and Integrative Biology | Year: 2016

We developed a new method to observe distribution of phosphatidylinositol 3, 5-bisphosphate [PtdIns(3, 5)P2] using electron microscopy. In freeze-fracture replicas of quick-frozen samples, PtdIns (3, 5)P2 was labeled specifically using recombinant ATG18 tagged with glutathione S-transferase and 4×FLAG, which was mixed with an excess of recombinant PX domain to suppress binding of ATG18 to phosphatidylinositol 3-phosphate. Using this method, PtdIns(3, 5)P2 was found to be enriched in limited domains in the yeast vacuole and mammalian endosomes. In the yeast vacuole exposed to hyperosmolar stress, PtdIns(3, 5)P2 was distributed at a significantly higher density in the intramembrane particle (IMP)-deficient liquid-ordered domains than in the surrounding IMP-rich domains. In mammalian cells, PtdIns(3, 5)P2 was observed in endosomes of tubulo-vesicular morphology labeled for RAB5 or RAB7. Notably, distribution density of PtdIns(3, 5)P2 in the endosome was significantly higher in the vesicular portion than in the tubular portion. The nanoscale distribution of PtdIns(3, 5)P2 revealed in the present study is important to understand its functional roles in the vacuole and endosomes. © 2016 Sho Takatori and Toyoshi Fujimoto.

Akazaki T.,The University of TokyoTokyo | Hasuo I.,The University of TokyoTokyo
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

Building on the work by Fainekos and Pappas and the one by Donz´e and Maler, we introduce AvSTL, an extension of metric interval temporal logic by averaged temporal operators. Its expressivity in capturing both space and time robustness helps solving falsification problems (searching for a critical path in hybrid system models); it does so by communicating a designer’s intention more faithfully to the stochastic optimization engine employed in a falsification solver. We also introduce a sliding window-like algorithm that keeps the cost of computing truth/robustness values tractable. © Springer International Publishing Switzerland 2015.

Soonglerdsongpha S.,The University of TokyoTokyo | Kasuga I.,The University of TokyoTokyo | Kurisu F.,The University of TokyoTokyo | Furumai H.,The University of TokyoTokyo
Sustainable Environment Research | Year: 2011

This study was to compare the removal efficiency of assimilable organic carbon (AOC) by biological activated carbon (BAC) filtration in three advanced drinking water treatment plants in Japan. The influence of total microbial abundances and bacterial community associated with BAC on AOC removal was also investigated. Results showed that AOC concentrations were increased after ozonation treatment. BAC filtration offered high removal efficiency of AOC from 53 to 73%. The highest reduction was observed in plant A. Total microorganisms on BAC in plant A, B and C enumerated by 4',6-diamidino-2-phenylindole staining method were 4.4 × 108, 9.0 × 108 and 5.1 × 108 cells g-1 wet, respectively. Cell-specific activity of AOC removal in BAC treatment followed the order of plant A, plant C and plant B. The bacterial community structures of raw water and BAC samples were investigated by polymerase chain reaction- denaturing gradient gel electrophoresis and Terminal Restriction Fragment Length Polymorphism.Bacterial communities in raw water of all three plants were similar but significantly different from those on BAC. This suggests that community structure changes along the treatment process. Bacterial community on BAC of plant A was slightly different from those on BAC of plant B and C. The difference in service time or retention time of BAC filtration might have some influence on bacterial community structures. © 2011, Chinese Institute of Environmental Engineering. All rights reserved.

Fujii W.,The University of TokyoTokyo | Onuma A.,The University of TokyoTokyo | Sugiura K.,The University of TokyoTokyo | Naito K.,The University of TokyoTokyo
Journal of Reproduction and Development | Year: 2014

Triple-knockout mice generated by the one-step CRISPR/Cas9 system were examined for the effects of multiple gene modifications on each phenotype and individual gene function. Sixty embryos were transferred, and 9 pups were obtained; all 9 pups had mutations on 3 loci, and 7 pups showed mutations in all-alleles. F0 mice showed knockout phenotypes or no protein expression of target genes simultaneously, and these mutations were normally inherited in the next generation. ©2014 by the Society for Reproduction and Development.

PubMed | Tokyo University of Information Sciences, The University of TokyoTokyo and Tokyo University of Science
Type: | Journal: Frontiers in neural circuits | Year: 2016

Cortical information processing of the onset, offset, and continuous plateau of an acoustic stimulus should play an important role in acoustic object perception. To date, transient activities responding to the onset and offset of a sound have been well investigated and cortical subfields and topographic representation in these subfields, such as place code of sound frequency, have been well characterized. However, whether these cortical subfields with tonotopic representation are inherited in the sustained activities that follow transient activities and persist during the presentation of a long-lasting stimulus remains unknown, because sustained activities do not exhibit distinct, reproducible, and time-locked responses in their amplitude to be characterized by grand averaging. To address this gap in understanding, we attempted to decode sound information from densely mapped sustained activities in the rat auditory cortex using a sparse parameter estimation method called sparse logistic regression (SLR), and investigated whether and how these activities represent sound information. A microelectrode array with a grid of 10 10 recording sites within an area of 4.0 mm 4.0 mm was implanted in the fourth layer of the auditory cortex in rats under isoflurane anesthesia. Sustained activities in response to long-lasting constant pure tones were recorded. SLR then was applied to discriminate the sound-induced band-specific power or phase-locking value from those of spontaneous activities. The highest decoding performance was achieved in the high-gamma band, indicating that cortical inhibitory interneurons may contribute to the sparse tonotopic representation in sustained activities by mediating synchronous activities. The estimated parameter in the SLR decoding revealed that the informative recording site had a characteristic frequency close to the test frequency. In addition, decoding of the four test frequencies demonstrated that the decoding performance of the SLR deteriorated when the test frequencies were close, supporting the hypothesis that the sustained activities were organized in a tonotopic manner. Finally, unlike transient activities, sustained activities were more informative in the belt than in the core region, indicating that higher-order auditory areas predominate over lower-order areas during sustained activities. Taken together, our results indicate that the auditory cortex processes sound information tonotopically and in a hierarchical manner.

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