685 results match your criteria: "the Graduate University for Advanced Studies SOKENDAI[Affiliation]"

Mathematical mechanism of state-dependent phase resetting properties of alpha rhythm in the human brain.

Neurosci Res

July 2020

RIKEN, CBS-TOYOTA Collaboration Center; RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan; Division of Neural Dynamics, Department of System Neuroscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan.

It is well-known that 10-Hz alpha oscillations in humans observed by electroencephalogram (EEG) are enhanced when the eyes are closed. Toward explaining this, a previous experimental study using manipulation by transcranial magnetic stimulation (TMS) revealed more global propagation of phase resetting in the eyes-open condition than in the eyes-closed condition in the alpha band. Those results indicate a significant increase of directed information flow across brain networks from the stimulated area to the rest of the brain when the eyes are open, suggesting that sensitivity to environmental changes and external stimuli is adaptively controlled by changing the dynamics of the alpha rhythm.

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Attention facilitates the gating of information from the sending brain area to the receiving areas, with this being achieved by dynamical changes in effective connectivity, which refers to the directional influences between cortical areas. To probe the effective connectivity and cortical excitability modulated by covertly shifted attention, transcranial magnetic stimulation (TMS) was used to directly perturb the right retinotopic visual cortex with respect to attended and unattended locations, and the impact of this was tracked from the stimulated area to other areas by concurrent use of electroencephalography (EEG). TMS to the contralateral visual hemisphere led to a stronger evoked potential than stimulation to the ipsilateral hemisphere.

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One of the major factors limiting biomass productivity in algae is the low thermodynamic efficiency of photosynthesis. The greatest thermodynamic inefficiencies in photosynthesis occur during the conversion of light into chemical energy. At full sunlight the light-harvesting antenna captures photons at a rate nearly 10 times faster than the rate-limiting step in photosynthetic electron transport.

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Polygenic Architecture of Human Neuroanatomical Diversity.

Cereb Cortex

April 2020

Human Genetics and Cognitive Functions Unit, Institut Pasteur, UMR 3571, CNRS, Université Paris Diderot, Paris 75015, France.

We analyzed the genomic architecture of neuroanatomical diversity using magnetic resonance imaging and single nucleotide polymorphism (SNP) data from >26 000 individuals from the UK Biobank project and 5 other projects that had previously participated in the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) consortium. Our results confirm the polygenic architecture of neuroanatomical diversity, with SNPs capturing from 40% to 54% of regional brain volume variance. Chromosomal length correlated with the amount of phenotypic variance captured, r ~ 0.

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A manifold learning approach to mapping individuality of human brain oscillations through beta-divergence.

Neurosci Res

July 2020

RIKEN CBS-TOYOTA Collaboration Center (BTCC), RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan; Division of Neural Dynamics, Department of System Neuroscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan.

This paper proposes an approach for visualizing individuality and inter-individual variations of human brain oscillations measured as multichannel electroencephalographic (EEG) signals in a low-dimensional space based on manifold learning. Using a unified divergence measure between spectral densities termed the "beta-divergence", we introduce an appropriate dissimilarity measure between multichannel EEG signals. Then, t-distributed stochastic neighbor embedding (t-SNE; a state-of-the-art algorithm for manifold learning) together with the beta-divergence based distance was applied to resting state EEG signals recorded from 100 healthy subjects.

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Adaptive trust calibration for human-AI collaboration.

PLoS One

May 2020

Department of Informatics, School of Multidisciplinary Sciences, The Graduate University for Advanced Studies (SOKENDAI), Tokyo, Japan.

Safety and efficiency of human-AI collaboration often depend on how humans could appropriately calibrate their trust towards the AI agents. Over-trusting the autonomous system sometimes causes serious safety issues. Although many studies focused on the importance of system transparency in keeping proper trust calibration, the research in detecting and mitigating improper trust calibration remains very limited.

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Testing the Seesaw Mechanism and Leptogenesis with Gravitational Waves.

Phys Rev Lett

January 2020

TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.

We present the possibility that the seesaw mechanism with thermal leptogenesis can be tested using the stochastic gravitational background. Achieving neutrino masses consistent with atmospheric and solar neutrino data, while avoiding nonperturbative couplings, requires right handed neutrinos lighter than the typical scale of grand unification. This scale separation suggests a symmetry protecting the right-handed neutrinos from getting a mass.

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The role of the significant flexibility of the β-turn in photoactive yellow protein (PYP) due to Gly115 was studied. G115A and G115P mutations were observed to accelerate the photocycle and shift the equilibrium between the late photocycle intermediate (pB) and its precursor (pR) toward pR. Thermodynamic analysis of dark-state recovery from pB demonstrated that the transition state (pB) has a negative change in transition heat capacity, suggesting that an exposed hydrophobic surface of pB is buried in pB.

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Cytoplasmic dynein is a dimeric motor protein which processively moves along microtubule. Its motor domain (head) hydrolyzes ATP and induces conformational changes of linker, stalk, and microtubule binding domain (MTBD) to trigger stepping motion. Here we applied scattering imaging of gold nanoparticle (AuNP) to visualize load-free stepping motion of processive dynein.

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Regioselective Bay-Functionalization of Perylenes Toward Tailor-Made Synthesis of Acceptor Materials for Organic Photovoltaics.

Chempluschem

February 2020

Department Department of Applied Chemistry Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan.

The development of an efficient synthetic protocol for multiply bay-functionalized perylenes and application of these products to photovoltaics are reported. Tetrabenzyl 1-(4-tert-butylphenoxy)perylene-3,4,9,10-tetracarboxylate underwent a regioselective bromination at the 7-position followed by a further bromination at the 12-position to provide a 7,12-dibromide in high 84% yield. This compound was transformed into a tetrasubstituted C -symmetric dibromide by a controlled monoetherification and a final bromination.

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In order to achieve deep tissue imaging, a number of optical clearing agents have been developed. However, in a conventional microscopy setup, an objective lens can only be moved until it is in contact with a coverslip, which restricts the maximum focusing depth into a cleared tissue specimen. Until now, it is still a fact that the working distance of a high magnification objective lens with a high numerical aperture is always about 100 μm.

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Deep Imaging Analysis in VISUAL Reveals the Role of YABBY Genes in Vascular Stem Cell Fate Determination.

Plant Cell Physiol

February 2020

Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan.

Stem cells undergo cell division and differentiation to ensure organized tissue development. Because plant cells are immobile, plant stem cells ought to decide their cell fate prior to differentiation, to locate specialized cells in the correct position. In this study, based on a chemical screen, we isolated a novel secondary cell wall indicator BF-170, which binds to lignin and can be used to image in vitro and in situ xylem development.

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Spatially extended ecological public goods, such as forests, grasslands, and fish stocks, are at risk of being overexploited by selfish consumers-a phenomenon widely recognized as the 'tragedy of the commons.' The interplay of spatial and ecological dimensions introduces new features absent in non-spatial ecological contexts, such as consumer mobility, local information availability, and strategy evolution through social learning in neighborhoods. It is unclear how these features interact to influence the harvesting and dispersal strategies of consumers.

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Smaller anterior subgenual cingulate volume mediates the effect of girls' early sexual maturation on negative psychobehavioral outcome.

Neuroimage

April 2020

Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study (UTIAS), The University of Tokyo, Tokyo, Japan; UTokyo Institute for Diversity and Adaptation of Human Mind (UTIDAHM), The University of Tokyo, Tokyo, Japan; UTokyo Center for Integrative Science of Human Behavior (CiSHuB), The University of Tokyo, Tokyo, Japan.

Early-maturing girls are relatively likely to experience compromised psychobehavioral outcomes. Some studies have explored the association between puberty and brain morphology in adolescents, while the results were non-specific for females or the method was a region-of-interest analysis. To our knowledge, no large-scale study has comprehensively explored the effects of pubertal timing on whole-brain volumetric development or the neuroanatomical substrates of the association in girls between pubertal timing and psychobehavioral outcomes.

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UNI-EM: An Environment for Deep Neural Network-Based Automated Segmentation of Neuronal Electron Microscopic Images.

Sci Rep

December 2019

Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi 36-1, Sakyo-ku, Kyoto, 606-8501, Japan.

Recently, there has been rapid expansion in the field of micro-connectomics, which targets the three-dimensional (3D) reconstruction of neuronal networks from stacks of two-dimensional (2D) electron microscopy (EM) images. The spatial scale of the 3D reconstruction increases rapidly owing to deep convolutional neural networks (CNNs) that enable automated image segmentation. Several research teams have developed their own software pipelines for CNN-based segmentation.

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Insights regarding skin regeneration in non-amniote vertebrates: Skin regeneration without scar formation and potential step-up to a higher level of regeneration.

Semin Cell Dev Biol

April 2020

Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, 3 Bunkyo-cho, Hirosaki 036-8561, Japan. Electronic address:

Skin wounds are among the most common injuries in animals and humans. Vertebrate skin is composed of an epidermis and dermis. After a deep skin injury in mammals, the wound heals, but the dermis cannot regenerate.

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In most animal cells, mitotic spindle formation is mediated by coordination of centrosomal and acentrosomal pathways. At the onset of mitosis, centrosomes promote spindle bipolarization. However, the mechanism through which the acentrosomal pathways facilitate the establishment of spindle bipolarity in early mitosis is not completely understood.

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Plant somatic cells reprogram and regenerate new tissues or organs when they are severely damaged. These physiological processes are associated with dynamic transcriptional responses but how chromatin-based regulation contributes to wound-induced gene expression changes and subsequent cellular reprogramming remains unknown. In this study we investigate the temporal dynamics of the histone modifications H3K9/14ac, H3K27ac, H3K4me3, H3K27me3, and H3K36me3, and analyze their correlation with gene expression at early time points after wounding.

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Optogenetics is now a fundamental tool for investigating the relationship between neuronal activity and behavior. However, its application to the investigation of motor control systems in nonhuman primates is rather limited, because optogenetic stimulation of cortical neurons in nonhuman primates has failed to induce or modulate any hand/arm movements. Here, we used a tetracycline-inducible gene expression system carrying CaMKII promoter and the gene encoding a Channelrhodopsin-2 variant with fast kinetics in the common marmoset, a small New World monkey.

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The abundance and distribution of highly radioactive cesium-rich microparticles (CsMPs) that were released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) during the first stage of the nuclear disaster in March 2011 are described for 20 surface soils collected around the FDNPP. Based on the spatial distribution of the numbers (particles/g) and radioactive fraction (RF) of the CsMPs in surface soil, which is defined as the sum of the CsMP radioactivity (in Bq) divided by the total radioactivity (in Bq) of the soil sample, three regions of particular interest have been identified: i.) near-northwest (N-NW), ii.

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Electrical stimulation of the primary somatosensory cortex using intracranial electrodes is crucial for the evocation of artificial somatosensations, typically tactile sensations associated with specific regions of the body, in brain-machine interface (BMI) applications. The qualitative characteristics of these artificially evoked somatosensations has been well documented. As of yet, however, the quantitative aspects of these evoked somatosensations, that is to say the quantitative relationship between intensity of electrical stimulation and perceived intensity of the resultant somatosensation remains obscure.

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Many plants can reproduce vegetatively, producing clonal progeny from vegetative cells; however, little is known about the molecular mechanisms underlying this process. Liverwort (Marchantia polymorpha), a basal land plant, propagates asexually via gemmae, which are clonal plantlets formed in gemma cups on the dorsal side of the vegetative thallus [1]. The initial stage of gemma development involves elongation and asymmetric divisions of a specific type of epidermal cell, called a gemma initial, which forms on the floor of the gemma cup [2, 3].

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Crystal structure of heliorhodopsin.

Nature

October 2019

Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.

Heliorhodopsins (HeRs) are a family of rhodopsins that was recently discovered using functional metagenomics. They are widely present in bacteria, archaea, algae and algal viruses. Although HeRs have seven predicted transmembrane helices and an all-trans retinal chromophore as in the type-1 (microbial) rhodopsin, they display less than 15% sequence identity with type-1 and type-2 (animal) rhodopsins.

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