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.

Sakuma M.,The University of TokyoTokyo | Kita S.,The University of TokyoTokyo | Higuchi H.,The University of TokyoTokyo
Science and Technology of Advanced Materials | Year: 2016

The processes involved in malignant gliomas damage were quantitatively evaluated by microscopy. The near-infrared fluorescent dye IR700 that is conjugated to an anti-CD133 antibody (IR700-CD133) specifically targets malignant gliomas (U87MG) and stem cells (BT142) and is endocytosed into the cells. The gliomas are then photodamaged by the release of reactive oxygen species (ROS) and the heat induced by illumination of IR700 by a red laser, and the motility of the vesicles within these cells is altered as a result of cellular damage. To investigate these changes in motility, we developed a new method that measures fluctuations in the intensity of phase-contrast images obtained from small areas within cells. The intensity fluctuation in U87MG cells gradually decreased as cell damage progressed, whereas the fluctuation in BT142 cells increased. The endocytosed IR700 dye was co-localized in acidic organelles such as endosomes and lysosomes. The pH in U87MG cells, as monitored by a pH indicator, was decreased and then gradually increased by the illumination of IR700, while the pH in BT142 cells increased monotonically. In these experiments, the processes of cell damage were quantitatively evaluated according to the motility of vesicles and changes in pH. © 2016 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis.

Daikoku T.,The University of TokyoTokyo | Yatomi Y.,The University of TokyoTokyo | Yumoto M.,The University of TokyoTokyo
Brain and Cognition | Year: 2016

The present study investigated whether neural responses could demonstrate the statistical learning of chord sequences and how the perception underlying a pitch class can affect the statistical learning of chord sequences. Neuromagnetic responses to two chord sequences of augmented triads that were presented every 0.5 s were recorded from fourteen right-handed participants. One sequence was a series of 360 chord triplets, each of which consisted of three chords in the same pitch class (clustered pitch-classes sequences). The other sequence was a series of 360 chord triplets, each of which consisted of three chords in different pitch classes (dispersed pitch-classes sequences). The order of the triplets was constrained by a first-order Markov stochastic model such that a forthcoming triplet was statistically defined by the most recent triplet (80% for one; 20% for the other two). We performed a repeated-measures ANOVA with the peak amplitude and latency of the P1m, N1m and P2m. In the clustered pitch-classes sequences, the P1m responses to the triplets that appeared with higher transitional probability were significantly reduced compared with those with lower transitional probability, whereas no significant result was detected in the dispersed pitch-classes sequences. Neuromagnetic significance was concordant with the results of familiarity interviews conducted after each learning session. The P1m response is a useful index for the statistical learning of chord sequences. Domain-specific perception based on the pitch class may facilitate the domain-general statistical learning of chord sequences. © 2016 Elsevier Inc.

Koso H.,Japan Institute for Molecular Science | Tsuhako A.,Japan Institute for Molecular Science | Lai C.-Y.,the University of TokyoTokyo | Baba Y.,Japan Institute for Molecular Science | And 5 more authors.
GLIA | Year: 2016

Neurodegeneration has been shown to induce microglial activation and the infiltration of monocyte-derived macrophages into the CNS, resulting in the coexistence of these two populations within the same lesion, though their distinct features remain elusive. To investigate the impact of rod photoreceptor degeneration on microglial activation, we generated a toxin-mediated genetic model of rod degeneration. Rod injury induced microglial proliferation and migration toward the photoreceptors. Bone marrow transplantation revealed the invasion of monocyte-derived macrophages into the retina, with microglia and the infiltrating macrophages showing distinct distribution patterns in the retina. By comparing the gene expression profiles of the activated microglia and infiltrating macrophages, we identified microglia-specific genes, including Ak1, Ctsf, Sall1, Phlda3, and Spns2. An analysis of Sall1gfp knock-in mice showed GFP expression in the microglia of developing and mature healthy retinas. DTA injury induced the expansion of Sall1gfp+ microglia, whereas Ly6C+ monocyte-derived macrophages were mostly Sall1gfp-, supporting the idea that Sall1 is exclusively expressed in microglia within the retinal phagocyte pool. We evaluated the contribution of microglia to the phagocyte pool in rd1 mutant retinas and found that Sall1gfp+ microglia constituted the majority of phagocytes. A Sall1 deficiency did not affect microglial colonization of the retina and the cortex, but it did change their morphology from a ramified to a more amoeboid appearance. The morphological defects observed in Sall1-deficient microglia were not rescued by the presence of wild-type non-microglial cells, suggesting that Sall1 functions cell-autonomously in microglia. Taken together, our data indicate that Sall1 regulates microglial morphology during development. GLIA 2016;64:2005–2024. © 2016 Wiley Periodicals, Inc.

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.

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