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Nagoya, Japan

Nagoya University , abbreviated to Meidai , is a Japanese national university headquartered in Chikusa-ku, Nagoya. It is the last Imperial University in Japan and among the National Seven Universities. It is the 4th best ranked higher education institution in Japan.As of 2014, six faculty and alumni of the university have won the Nobel Prize in science. Wikipedia.

Yamazaki D.G.,Japan National Astronomical Observatory | Kajino T.,Japan National Astronomical Observatory | Kajino T.,University of Tokyo | Mathews G.J.,University of Notre Dame | Ichiki K.,Nagoya University
Physics Reports | Year: 2012

Magnetic fields appear wherever plasma and currents can be found. As such, they thread through all scales in Nature. It is natural, therefore, to suppose that magnetic fields might have been formed within the high temperature environments of the big bang. Such a primordial magnetic field (PMF) would be expected to arise from and/or influence a variety of cosmological phenomena such as inflation, cosmic phase transitions, big bang nucleosynthesis, the cosmic microwave background (CMB) temperature and polarization anisotropies, the cosmic gravity wave background, and the formation of large-scale structure. In this review, we summarize the development of theoretical models for analyzing the observational consequences of a PMF. We also summarize the current state of the art in the search for observational evidence of a PMF. In particular, we review the framework needed to calculate the effects of a PMF power spectrum on the CMB and the development of large scale structure. We summarize the current constraints on the PMF amplitude . BΛ and the power spectral index . nB and discuss prospects for better determining these quantities in the near future. © 2012 Elsevier B.V. Source

Sugiyama H.,University of Toyama | Tsumura K.,Nagoya University | Yokoya H.,National Taiwan University | Yokoya H.,University of Toyama
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012

The doubly charged scalar boson (H ±±) is introduced in several models of the new physics beyond the standard model. The H ±± has Yukawa interactions with two left-handed charged leptons or two right-handed charged leptons depending on the models. We study kinematical properties of H ±± decay products through tau leptons in order to discriminate the chiral structures of the new Yukawa interaction. The chirality of tau leptons can be measured by the energy distributions of the tau decay products, and thus the chiral structure of the new Yukawa interaction can be traced in the invariant-mass distributions of the H ±± decay products. We perform simulation studies for the typical decay patterns of the H ±± with simple event selections and tau-tagging procedures, and show that the chiral structure of the Yukawa interactions of H ±± can be distinguished by measuring the invariant-mass distributions. © 2012 Elsevier B.V. Source

The propagation of collisionless shock waves and the influence of the space-charge field on the development of fluid instabilities induced by a collisionless shock wave are investigated by solving the two-fluid plasma equations numerically in two space-dimensions. A second-order accurate Riemann solver is employed to sharply capture the shock wave and contact discontinuity. First, a series of shock-tube problems is solved to verify the method. The shock structure similar to that obtained in a previous particle-in-cell (PIC) simulation is reproduced. However, it is found that the shock wave propagates at speeds higher than the PIC results for high initial density ratios at the shock tube diaphragm. Second, the interactions between a collisionless shock wave of Mach number 1.6 and an isolated cylindrical bubble of Atwood number 0.81 are investigated. It is found that in addition to the well-known Richtmyer-Meshkov instability, filamentary fluid-instability is induced at the bubble interface introducing turbulence in the region ahead of the shock wave. © 2012 American Institute of Physics. Source

Erhart J.,Vienna University of Technology | Sponar S.,Vienna University of Technology | Sulyok G.,Vienna University of Technology | Badurek G.,Vienna University of Technology | And 2 more authors.
Nature Physics | Year: 2012

The uncertainty principle generally prohibits simultaneous measurements of certain pairs of observables and forms the basis of indeterminacy in quantum mechanics 1. Heisenberg's original formulation, illustrated by the famous γ-ray microscope, sets a lower bound for the product of the measurement error and the disturbance 2. Later, the uncertainty relation was reformulated in terms of standard deviations 3-5, where the focus was exclusively on the indeterminacy of predictions, whereas the unavoidable recoil in measuring devices has been ignored 6. A correct formulation of the error-disturbance uncertainty relation, taking recoil into account, is essential for a deeper understanding of the uncertainty principle, as Heisenberg's original relation is valid only under specific circumstances 7-10. A new error-disturbance relation, derived using the theory of general quantum measurements, has been claimed to be universally valid 11-14. Here, we report a neutron-optical experiment that records the error of a spin-component measurement as well as the disturbance caused on another spin-component. The results confirm that both error and disturbance obey the new relation but violate the old one in a wide range of an experimental parameter. © 2012 Macmillan Publishers Limited. All rights reserved. Source

Reflective light collectors with hexagonal entrance and exit apertures are frequently used in front of the focal-plane camera of a very-high-energy gamma-ray telescope to increase the collection efficiency of atmospheric Cherenkov photons and reduce the night-sky background entering at large incident angles. The shape of a hexagonal light collector is usually based on Winston's design, which is optimized for only two-dimensional optical systems. However, it is not known whether a hexagonal Winston cone is optimal for the real three-dimensional optical systems of gamma-ray telescopes. For the first time we optimize the shape of a hexagonal light collector using quadratic and cubic Bézier curves. We demonstrate that our optimized designs simultaneously achieve a higher collection efficiency and background reduction rate than traditional designs. © 2012 Elsevier B.V. All rights reserved. Source

Shiraishi M.,Nagoya University
Journal of Cosmology and Astroparticle Physics | Year: 2012

We study the parity violation in the cosmic microwave background (CMB) bispectrum induced by primordial magnetic fields (PMFs). Deriving a general formula for the CMB bispectrum generated from not only non-helical but also helical PMFs, we find that helical PMFs produce characteristic signals, which disappear in parity-conserving cases, such as the intensity-intensity-intensity bispectra arising from ∑ 3 n=1ℓ n = odd. For fast numerical calculation of the CMB bispectrum, we reduce the one-loop formula to the tree-level one by using the so-called pole approximation. Then, we show that the magnetic anisotropic stress, which depends quadratically on non-helical and helical PMFs and acts as a source of the CMB fluctuation, produces the local-type non-Gaussianity. Comparing the CMB bispectra composed of the scalar and tensor modes with the noise spectra, we find that assuming the generation of the nearly scale-invariant non-helical and helical PMFs from the grand unification energy scale (10 14GeV) to the electroweak one (10 3GeV), the intensity-intensity-intensity bispectrum for ∑ 3 n=1ℓ n = odd can be observed by the WMAP experiment under the condition that B 1Mpc; 2/3 1Mpc; 1/3 > 2.7-4.5nG with B 1Mpc; and 1Mpc; being the non-helical and helical PMF strengths smoothed on 1 Mpc, respectively. © 2012 IOP Publishing Ltd and Sissa Medialab srl. Source

Hiwatashi Y.,Aberystwyth University | Sato Y.,Nagoya University | Doonan J.H.,Aberystwyth University
Plant Cell | Year: 2014

Microtubules (MTs) play a crucial role in the anisotropic deposition of cell wall material, thereby affecting the direction of growth. A wide range of tip-growing cells display highly polarized cell growth, and MTs have been implicated in regulating directionality and expansion. However, the molecular machinery underlying MT dynamics in tip-growing plant cells remains unclear. Here, we show that highly dynamic MT bundles form cyclically in the polarized expansion zone of the moss Physcomitrella patens caulonemal cells through the coalescence of growing MT plus ends. Furthermore, the plant-specific kinesins (KINID1) that are is essential for the proper MT organization at cytokinesis also regulate the turnover of the tip MT bundles as well as the directionality and rate of cell growth. The plus ends of MTs grow toward the expansion zone, and KINID1 is necessary for the stability of a single coherent focus of MTs in the center of the zone, whose formation coincides with the accumulation of KINID1. We propose that KINID-dependent MT bundling is essential for the correct directionality of growth as well as for promoting growth per se. Our findings indicate that two localized cell wall deposition processes, tip growth and cytokinesis, previously believed to be functionally and evolutionarily distinct, share common and plant-specific MT regulatory components. © 2014 American Society of Plant Biologists. All rights reserved. Source

Okada R.,Nagoya University
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association | Year: 2012

This study aimed to investigate the associations of hyperfiltration and hypofiltration with prediabetes and prehypertension. The study subjects included 99 140 people aged 20-89 years who underwent health checkups in Aichi Prefecture, Japan. The prevalence of hyperfiltration [estimated glomerular filtration rate (eGFR) above the age-/sex-specific 95th percentile] and hypofiltration (eGFR below the age-/sex-specific 5th percentile) was compared among stages of prediabetes (fasting plasma glucose <100, 100-109, 110-125 and ≥126 mg/dL for no prediabetes, Stage 1 prediabetes, Stage 2 prediabetes and diabetes, respectively) and prehypertension [blood pressure (BP) <120/80, 120-129/80-84, 130-139/85-89 and ≥140/90 mmHg for no prehypertension, Stage 1 prehypertension, Stage 2 prehypertension and hypertension, respectively). The prevalence of hyperfiltration increased with increasing stage of prediabetes [odds ratios (ORs): 1.29, 1.58 and 2.47 for Stage 1 prediabetes, Stage 2 prediabetes and diabetes, respectively] and prehypertension (ORs: 1.10, 1.33 and 1.52 for Stage 1 prehypertension, Stage 2 prehypertension and hypertension, respectively). Hypofiltration was not associated with prediabetes or prehypertension. The prevalence of glomerular hyperfiltration increased with increasing stages of prediabetes and prehypertension. Therefore, kidney function should be monitored in subjects with prediabetes or prehypertension. In subjects with hyperfiltration, earlier treatment of hyperglycemia and high BP may be necessary to prevent the development of kidney damage. Source

Hayashi M.,Nagoya University | Hayashi M.,National University of Singapore | Tsurumaru T.,MItsubishi Electric
New Journal of Physics | Year: 2012

We present a tight security analysis of the Bennett-Brassard 1984 protocol taking into account the finite-size effect of key distillation and achieving unconditional security. We begin by presenting a concise analysis utilizing the normal approximation of the hypergeometric function. Next we show that a similar tight bound can also be obtained by a rigorous argument without relying on any approximation. In particular, for the convenience of experimentalists who wish to evaluate the security of their quantum key distribution systems, we also give the explicit procedures of our key distillation and show how to calculate the secret key rate and the security parameter from a given set of experimental parameters. In addition to the exact values of key rates and security parameters, we also describe how to obtain their rough estimates using the normal approximation. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Source

Buratti M.,University of Perugia | Momihara K.,Nagoya University
Designs, Codes, and Cryptography | Year: 2011

We investigate further the existence question regarding optimal (v, 4, 2, 1) optical orthogonal codes begun in Momihara and Buratti (IEEE Trans Inform Theory 55:514-523, 2009). We give some non-existence results for infinitely many values of v ≡ ± 3 (mod 9) and several explicit constructions for infinite classes of perfect optical orthogonal codes. © 2010 Springer Science+Business Media, LLC. Source

Yamamoto T.T.,Nagoya University
Astronomy and Astrophysics | Year: 2012

Context. The area asymmetry between the preceding and following regions of opposite magnetic polarity in a bipolar sunspot group has been known since the studies of Hale and his colleagues in the early 20th century. This area asymmetry, however, has not yet been investigated quantitatively using magnetograms. Aims. We quantitatively define the area asymmetry of bipolar magnetic fields in the photosphere of active regions on the Sun, and investigate correlations between the area asymmetry and other parameters. Methods. We selected 138 bipolar regions including eleven recurrent regions from magnetograms observed by the Michelson Doppler Imager (MDI) from 23 April 1996 to 2 September 2001. These regions are on the southern hemisphere and around the solar meridian. The area asymmetry (A), tilt angle (θ), and magnetic orientation (M) are investigated separately in the preceding and following polarities of the respective active regions. Results. It is found that in 37% (51/138) of our events the preceding polarity regions have larger areas than the following polarity regions. The ratio of the area of the preceding and following polarity regions become close to be unity in four recurrent active regions. In the other four regions, the area ratios do not change, and in three regions, the area ratios become far from unity. Conclusions. Our results quantitatively confirmed our impression that areas of the preceding polarities are lower than those of the following polarities in many bipolar magnetic regions. © 2012 ESO. Source

Kumagai S.,University of Occupational and Environmental Health Japan | Kurumatani N.,Nara Medical University | Arimoto A.,Red Cross | Ichihara G.,Nagoya University
Occupational and Environmental Medicine | Year: 2013

Objectives The present study was conducted to investigate the relationship between occupational chemical exposure and incidence of cholangiocarcinoma among workers in the offset colour proof-printing section of a small printing company in Osaka, Japan. Methods We identified 51 men who had worked in the proof-printing room, and 11 men who had worked in the front room for at least 1 year between 1991 and 2006. We interviewed them about the chemicals they used, and estimated their levels of exposure to chemicals. We also investigated the medical records of 11 cholangiocarcinoma patients, and calculated the standardised mortality ratio (SMR) from 1991 to 2011. Results Workers used 1,2-dichloropropane (1,2-DCP) from approximately 1985 to 2006, and dichloromethane (DCM) from approximately 1985 to 1997/1998. Exposure concentrations were estimated to be 100-670 ppm for 1,2-DCP and 80-540 ppm for DCM among the proof-printing workers. All 11 patients were pathologically diagnosed with cholangiocarcinoma. Ages at diagnosis were 25-45 years, and ages at death were 27-46 years among the six deceased individuals. The primary cancer site was the intrahepatic bile duct for five patients, and the extrahepatic bile ducts for six. All patients were exposed to 1,2-DCP for 7-17 years and diagnosed with cholangiocarcinoma 7-20 years after their first exposure. Ten patients were also exposed to DCM for 1-13 years. The SMR for cholangiocarcinoma was 2900 (expected deaths: 0.00204, 95% CI 1100 to 6400) for all workers combined. Conclusions These findings suggest that 1,2-DCP and/or DCM may cause cholangiocarcinoma in humans. Source

Although the neurodevelopmental and genetic underpinnings of autism spectrum disorder (ASD) have been investigated, the etiology of the disorder has remained elusive, and clinical diagnosis continues to rely on symptom-based criteria. In this study, to classify both control subjects and a large sample of patients with ASD, we used resting state functional magnetic resonance imaging (rs-fMRI) and a neural network. Imaging data from 312 subjects with ASD and 328 subjects with typical development was downloaded from the multi-center research project. Only subjects under 20 years of age were included in this analysis. Correlation matrices computed from rs-fMRI time-series data were entered into a probabilistic neural network (PNN) for classification. The PNN classified the two groups with approximately 90% accuracy (sensitivity=92%, specificity=87%). The accuracy of classification did not differ among the institutes, or with respect to experimental and imaging conditions, sex, handedness, or intellectual level. Medication status and degree of head movement did not affect accuracy values. The present study indicates that an intrinsic connectivity matrix produced from rs-fMRI data could yield a possible biomarker of ASD. These results support the view that altered network connectivity within the brain contributes to the neurobiology of ASD. © 2014 Elsevier Ltd. Source

Wachino J.-I.,Japan National Institute of Infectious Diseases | Arakawa Y.,Japan National Institute of Infectious Diseases | Arakawa Y.,Nagoya University
Drug Resistance Updates | Year: 2012

Exogenously acquired 16S rRNA methyltransferase (16S-RMTase) genes responsible for a very high level of resistance against various aminoglycosides have been widely distributed among Enterobacteriaceae and glucose- nonfermentative microbes recovered from human and animal. The 16S-RMTases are classified into two subgroups, N7-G1405 16S-RMTases and N1-A1408 16S-RMTases, based on the mode of modification of 16S rRNA. Both MTases add the methyl group of S-adenosyl-l-methionine (SAM) to the specific nucleotides at the A-site of 16S rRNA, which interferes with aminoglycoside binding to the target. The genetic determinants responsible for 16S-RMTase production are often mediated by mobile genetic elements like transposons and further embedded into transferable plasmids or chromosome. This genetic apparatus may thus contribute to the rapid worldwide dissemination of the resistance mechanism among pathogenic microbes. More worrisome is the fact that 16S-RMTase genes are frequently associated with other antimicrobial resistance mechanisms such as NDM-1 metallo-β-lactamase and CTX-M-type ESBLs, and some highly pathogenic microbes including Salmonella spp. have already acquired these genes. Thus far, 16S-RMTases have been reported from at least 30 countries or regions. The worldwide dissemination of 16S-RMTases is becoming a serious global concern and this implies the necessity to continue investigations on the trend of 16S-RMTases to restrict their further worldwide dissemination. © 2012 Elsevier Ltd. All rights reserved. Source

Fujiyoshi Y.,Nagoya University
Methods in molecular biology (Clifton, N.J.) | Year: 2013

In biological science, there are still many interesting and fundamental yet difficult questions, such as those in neuroscience, remaining to be answered. Structural and functional studies of membrane proteins, which are key molecules of signal transduction in neural and other cells, are essential for understanding the molecular mechanisms of many fundamental biological processes. Technological and instrumental advancements of electron microscopy have facilitated comprehension of structural studies of biological components, such as membrane proteins. While X-ray crystallography has been the main method of structure analysis of proteins including membrane proteins, electron crystallography is now an established technique to analyze structures of membrane proteins in the lipid bilayer, which is close to their natural biological environment. By utilizing cryo-electron microscopes with helium-cooled specimen stages, structures of membrane proteins were analyzed at a resolution better than 3 Å. Such high-resolution structural analysis of membrane proteins by electron crystallography opens up the new research field of structural physiology. Considering the fact that the structures of integral membrane proteins in their native membrane environment without artifacts from crystal contacts are critical in understanding their physiological functions, electron crystallography will continue to be an important technology for structural analysis. In this chapter, I will present several examples to highlight important advantages and to suggest future directions of this technique. Source

Iritani S.,Nagoya University
Nagoya Journal of Medical Science | Year: 2013

Studies that seek to determine the etiology of schizophrenia through pathological images and morphological abnormalities of the brain have been conducted since the era of E. Kraepelin, and pioneers in neuropathology such as A. Alzheimer have also eagerly pursued such studies. However, there have been no disease-specific findings, and there was a brief era in which it was said that "schizophrenia is the graveyard of neuropathologists." However, since the 1980s, neuroimaging studies with CT and MRI etc., have been used in many reports of cases of schizophrenia with abnormal brain morphology, thus generating renewed interest in developments within brain tissue and leading to new neuropathological studies. There are now many reports in which, in addition to morphological observations, cell distribution and the like are image-processed and statistically processed through computers. Due to methodological problems in making progress in the field of cerebral pathology, we have not yet been able to observe disease-specific findings, although there are several findings with high certainty. However, the neurodevelopmental hypothesis has been supported as being able to reasonably explain the accumulated findings of previous studies. At the same time, results of recent molecular-biological studies have revealed the risk genes for this disease, and because many of those genes are associated with functions related to nerve differentiation, development, and plasticity, there is growing interest in their correlations with cerebral pathology. We are now on the verge of uncovering the etiology of this disease by integrating cerebral neuroimaging, molecular genetics, and cerebral neuropathology. In that sense, neuropathological studies of this disease from new viewpoints have become essential. Source

Sato J.,Saitama University | Yamanaka M.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We consider the case that the μ-e conversion signal is discovered but other charged lepton flavor violating (cLFV) processes will never be found. In such a case, we need other approaches to confirm the μ-e conversion and its underlying physics without conventional cLFV searches. We study R-parity violating (RPV) SUSY models as a benchmark. We briefly review that our interesting case is realized in RPV SUSY models with reasonable settings in light of current theoretical and experimental status. We focus on the exotic collider signatures at the LHC (pp→μ-e+ and pp→jj) as the other approaches. We show the correlations between the branching ratio of the μ-e conversion process and cross sections of these processes. It is the first time that these correlations have been graphically shown. We exhibit the RPV parameter dependence of the branching ratio and the cross sections and discuss the feasibility of determining the parameters. © 2015 American Physical Society. Source

Akamatsu Y.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We derive the quantum master equations for heavy quark systems in a high-temperature quark-gluon plasma in the Lindblad form. The master equations are derived in the influence functional formalism for open quantum systems in perturbation theory. These master equations have a wide range of applications, such as decoherence of a heavy quarkonium and Langevin dynamics of a heavy quark in the quark-gluon plasma. We also show the equivalence between the quarkonium master equations in the recoilless limit and the Schrödinger equations with stochastic potential. © 2015 American Physical Society. Source

Hayashi M.,Nagoya University | Hayashi M.,National University of Singapore | Morimae T.,Gunma University
Physical Review Letters | Year: 2015

We introduce a simple protocol for verifiable measurement-only blind quantum computing. Alice, a client, can perform only single-qubit measurements, whereas Bob, a server, can generate and store entangled many-qubit states. Bob generates copies of a graph state, which is a universal resource state for measurement-based quantum computing, and sends Alice each qubit of them one by one. Alice adaptively measures each qubit according to her program. If Bob is honest, he generates the correct graph state, and, therefore, Alice can obtain the correct computation result. Regarding the security, whatever Bob does, Bob cannot get any information about Alice's computation because of the no-signaling principle. Furthermore, malicious Bob does not necessarily send the copies of the correct graph state, but Alice can check the correctness of Bob's state by directly verifying the stabilizers of some copies. © 2015 American Physical Society. Source

Moriyama S.,Nagoya University | Moriyama S.,Kyoto University | Nosaka T.,Kyoto University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

The coefficients of the membrane instantons in the ABJM theory are known to be quadratic polynomials of the chemical potential. For better insight into this nonconstantness, we consider more general superconformal Chern-Simons theories labelled by two parameters (q,p). In these theories, we show that the membrane instantons split into three types of nonperturbative effects, one more type compared with the previous observation. We also determine their explicit coefficients which are independent of the chemical potential. We find that, although these constants contain poles at certain values of q and p including the ABJM case, all of the poles cancel among themselves, and the finite quadratic polynomial coefficients are reproduced at these values. This is similar to what happens between the membrane instantons and the worldsheet instantons in the ABJM theory. © 2015 American Physical Society. Source

Blum T.,University of Connecticut | Blum T.,Brookhaven National Laboratory | Chowdhury S.,University of Connecticut | Hayakawa M.,Nagoya University | And 2 more authors.
Physical Review Letters | Year: 2015

The most compelling possibility for a new law of nature beyond the four fundamental forces comprising the standard model of high-energy physics is the discrepancy between measurements and calculations of the muon anomalous magnetic moment. Until now a key part of the calculation, the hadronic light-by-light contribution, has only been accessible from models of QCD, the quantum description of the strong force, whose accuracy at the required level may be questioned. A first principles calculation with systematically improvable errors is needed, along with the upcoming experiments, to decisively settle the matter. For the first time, the form factor that yields the light-by-light scattering contribution to the muon anomalous magnetic moment is computed in such a framework, lattice QCD+QED and QED. A nonperturbative treatment of QED is used and checked against perturbation theory. The hadronic contribution is calculated for unphysical quark and muon masses, and only the diagram with a single quark loop is computed for which statistically significant signals are obtained. Initial results are promising, and the prospect for a complete calculation with physical masses and controlled errors is discussed. © 2015 American Physical Society. Source

Norimatsu W.,Nagoya University | Kusunoki M.,EcoTopia Science Institute
Physical Chemistry Chemical Physics | Year: 2014

We review here recent progress on epitaxial graphene grown on a SiC substrate. Epitaxial graphene can be easily grown by heating the SiC single crystal in a high vacuum or in an inert gas atmosphere. The SiC surfaces used for graphene growth contain Si- and C-terminated faces. On the Si-face, homogeneous and clean graphene can be grown with a controlled number of layers, and the carrier mobility reaches as high as several m2 V s -1, although this is reduced by the presence of the substrate steps. On the C-face, although the number of layers is not homogeneous, twisted bilayer graphene can be grown, which is expected to be the technique of choice to modify the electronic structure of graphene. From the application point of view, graphene on SiC will be the platform used to fabricate high-speed electronic devices and dense graphene nanoribbon arrays, which will be used to introduce a bandgap. © 2014 the Owner Societies. Source

Mori K.,Nagoya University
Medical Image Analysis | Year: 2016

This paper gives our perspective on the next two decades of computational anatomy, which has made great strides in the recognition and understanding of human anatomy from conventional clinical images. The results from this field are now used in a variety of medical applications, including quantitative analysis of organ shapes, interventional assistance, surgical navigation, and population analysis. Several anatomical models have also been used in computational anatomy, and these mainly target millimeter-scale shapes. For example, liver-shape models are almost completely modeled at the millimeter scale, and shape variations are described at such scales. Most clinical 3D scanning devices have had just under 1 or 0.5 mm per voxel resolution for over 25 years, and this resolution has not changed drastically in that time. Although . Z-axis (head-to-tail direction) resolution has been drastically improved by the introduction of multi-detector CT scanning devices, in-plane resolutions have not changed very much either. When we look at human anatomy, we can see different anatomical structures at different scales. For example, pulmonary blood vessels and lung lobes can be observed in millimeter-scale images. If we take 10-μm-scale images of a lung specimen, the alveoli and bronchiole regions can be located in them. Most work in millimeter-scale computational anatomy has been done by the medical-image analysis community. In the next two decades, we encourage our community to focus on micro-scale computational anatomy. In this perspective paper, we briefly review the achievements of computational anatomy and its impacts on clinical applications; furthermore, we show several possibilities from the viewpoint of microscopic computational anatomy by discussing experimental results from our recent research activities. © 2016 Elsevier B.V. Source

Yamamoto Y.,Nagoya University
Chemical Society Reviews | Year: 2014

Transition-metal (TM)-catalyzed hydroarylation reactions of alkynes have received much attention, because they enable the net insertion of alkyne C-C triple bonds into C-H bonds of aromatic precursors, resulting in regio- and stereo-selective formation of synthetically useful arylalkenes. Taking advantage of this feature, TM-catalyzed alkyne hydroarylations have been successfully used for the synthesis of heterocycles. TM-catalyzed alkyne hydroarylations can be classified into three major categories depending on the type of reaction and precursors involved: (1) palladium-catalyzed reductive Heck reactions of alkynes with aryl halides, (2) TM-catalyzed conjugate arylation reactions of activated alkynes with arylboronic acids, and (3) TM-catalyzed aromatic C-H alkenylations with alkynes. This review surveys heterocycle synthesis via TM-catalyzed hydroarylation of alkynes according to the above classification, with an emphasis on the scope and limitations, as well as the underlying mechanisms. © 2014 The Royal Society of Chemistry. Source

Nakao A.,Nagoya University
Digestive Surgery | Year: 2016

Isolated pancreatoduodenectomy (PD) is an ideal surgery for pancreatic head cancer. In cancer surgery, 'isolated' means en bloc resection using a non-touch isolation technique. I have been developing isolated PD for pancreatic cancer since 1981. In this operation, the most important and first step is to use a mesenteric approach instead of Kocher's maneuver. The precise surgical techniques of the mesenteric approach are introduced in this paper. © 2016 S. Karger AG, Basel. Source

Shinohara H.,Nagoya University
Chemical Record | Year: 2012

With the advent of the Krätschmer-Huffman historical breakthrough on the macroscopic synthesis of C 60 in the late summer of 1990, I decided to stop all my research so far in the area of spectroscopy of gas-phase molecular microclusters. Since then, my odyssey in and quest for the so-called nanocarbons started. Thanks to the brand-new and enchanting world of fullerenes, metallofullerenes, carbon nanotubes and nano-peapods, I have been able to entertain (and still am entertaining!) "the pleasure of finding things out", as Richard Feynman once put it in an interview by a BBC television program in 1981. I believe that as long as one has big dreams and lays the groundwork for the dreams, one will achieve them. My quest for nanocarbons is still on its way. © 2012 The Chemical Society of Japan and Wiley-VCH, Weinheim. Source

Fukutomi Y.,Japan Agency for Marine - Earth Science and Technology | Yasunari T.,Nagoya University
Climate Dynamics | Year: 2013

This study examines wave disturbances on submonthly (6-30-day) timescales over the tropical Indian Ocean during Southern Hemisphere summer using Japanese Reanalysis (JRA25-JCDAS) products and National Oceanic and Atmospheric Administration outgoing longwave radiation data. The analysis period is December-February for the 29 years from 1979/1980 through 2007/2008. An extended empirical orthogonal function (EEOF) analysis of daily 850-hPa meridional wind anomalies reveals a well-organized wave-train pattern as a dominant mode of variability over the tropical Indian Ocean. Daily lagged composite analyses for various atmospheric variables based on the EEOF result show the structure and evolution of a wave train consisting of meridionally elongated troughs and ridges along the Indian Ocean Intertropical Convergence Zone (ITCZ). The wave train is oriented in a northeast-southwest direction from Sumatra toward Madagascar. The waves have zonal wavelengths of about 3,000-5,000 km and exhibit westward and southwestward phase propagation. Individual troughs and ridges as part of the wave train sequentially travel westward and southwestward from the west of Sumatra into Madagascar. Meanwhile, eastward and northeastward amplification of the wave train occurs associated with the successive growth of new troughs and ridges over the equatorial eastern Indian Ocean. This could be induced by eastward and northeastward wave energy dispersion from the southwestern to eastern Indian Ocean along the mean monsoon westerly flow. In addition, the waves modulate the ITCZ convection. Correlation statistics show the average behavior of the wave disturbances over the tropical Indian Ocean. These statistics and other diagnostic measures are used to characterize the waves obtained from the composite analysis. The waves appear to be connected to the monsoon westerly flow. The waves tend to propagate through a band of the large meridional gradient of absolute vorticity produced by the mean monsoon westerly flow. This suggests that the monsoon westerly flow provides favorable background conditions for the propagation and maintenance of the waves and acts as a waveguide over the tropical Indian Ocean. The horizontal structure of the wave train may be interpreted as that of a mixture of equatorial Rossby waves and mixed Rossby-gravity wavelike gyres. © 2012 The Author(s). Source

Oshima K.,University of Chicago | Oshima K.,Nagoya University | Fehon R.G.,University of Chicago
Journal of Cell Science | Year: 2011

Barrier junctions prevent pathogen invasion and restrict paracellular leakage across epithelial sheets. To understand how one barrier junction, the septate junction (SJ), is regulated in vivo, we used fluorescence recovery after photobleaching (FRAP) to examine SJ protein dynamics in Drosophila. Most SJ-associated proteins, including Coracle, Neurexin IV and Nervana 2, displayed similar, extremely immobile kinetics. Loss of any of these components resulted in dramatically increased mobility of all others, suggesting that they form a single, highly interdependent core complex. Immobilization of SJ core components coincided with formation of the morphological SJ but occurred after their known role in maintaining epithelial polarity, suggesting that these functions are independent. In striking contrast to the core components, the tumor suppressor protein Discs large was much more mobile and its loss did not affect mobility of core SJ proteins, suggesting that it is not a member of this complex, even though it colocalizes with the SJ. Similarly, disruption of endocytosis affected localization of SJ core components, but did not affect their mobility. These results indicate that formation of a stable SJ core complex is separable from its proper subcellular localization, and provide new insights into the complex processes that regulate epithelial polarity and assembly of the SJ. © 2011. Published by The Company of Biologists Ltd. Source

Sirono S.-I.,Nagoya University
Earth, Planets and Space | Year: 2013

One of the probable scenarios of differentiation between silicate-ice in an icy object is the settling of a silicate particle in water after the melting of the object. In order for settling to proceed or occur, the size of the particle should be sufficiently large such that the settling velocity of the particle exceeds the background flow velocity induced by thermal convection. The sizes of the particles change because of dissolution and precipitation. This process is called ripening. In this study, the critical particle sizes required for settling, and the timescales for the growth of the particles to these sizes through ripening, are analytically derived. It is observed that settling is possible if the silicate particles coagulate with each other to form a network in water. If the particles do not coagulate, the probability of the occurrence of settling is low, because the time duration required for the particle growth to the critical size is large. The coagulation of silicate particles strongly depends on the pH of the water. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS). Source

Yamaguchi S.,Nagoya University
Journal of the American Chemical Society | Year: 2014

The synthesis of a planarized trinaphthylborane with partially fused structure is presented. This compound shows not only high chemical and thermal stability but also sufficient Lewis acidity to form Lewis adducts with pyridine derivatives in solution. The B-N Lewis adducts exhibit unprecedented photodissociation behavior in the excited state, reminiscent of the photogeneration of carbenium ions from triarylmethane leuco dyes. Consequently, these B-N Lewis adducts exhibit dual fluorescence emission arising from the initial tetracoordinate B-N adducts and the photodissociated tricoordinate boranes. © 2014 American Chemical Society. Source

Ishihara K.,Nagoya University
Topics in Organometallic Chemistry | Year: 2015

Although boric acid (B(OH)3) and boronic acids (RB(OH)2) behave as oligomeric mixtures, these boron compounds, as well as borane, electrophilically activate carboxylic acids as a mixed anhydride under equilibrium. In particular, electron-deficient arylboronic acids are useful as Lewis or Brønsted acid catalysts. The pKa of boronic acids is in the range of 5–9, which is significantly higher than that of the strong protic acids. However, diortho-substituted arylboronic acids with electron-withdrawing groups are unstable and are easily decomposed by basepromoted protodeboronation. In this chapter, the main emphasis is upon the recent progress on boronic acid-catalyzed reactions of carboxylic acids, as well as a few other reactions which can be catalyzed by boronic acids. © Springer International Publishing Switzerland 2015. Source

Terasaki I.,Nagoya University
Journal of Applied Physics | Year: 2011

We have evaluated the power factor of transition metal oxides at high temperatures using the Heikes formula and the Ioffe-Regel conductivity. The evaluated power factor is found to be nearly independent of carrier concentration in a wide range of doping, and explains the experimental data for cobalt oxides well. This suggests that the same power factor can be obtained with a thermopower larger than 2kB/e, and also suggests a reasonably high value of the dimensionless figure of merit ZT. We propose an oxide thermoelectric power generator by using materials having a thermopower larger than 300 V/K. © 2011 American Institute of Physics. Source

Noyori R.,RIKEN | Noyori R.,Nagoya University
Angewandte Chemie - International Edition | Year: 2013

The art of science: The field of asymmetric catalysis has evolved over nearly 50 years from a seemingly insignificant investigation into a copper-catalyzed cyclopropanation reaction to applications that bring global benefits. In this Essay, Nobel Laureate Ryoji Noyori outlines the history of asymmetric catalysis using a chiral organometallic complex, and explains how scientific discovery requires not only talent but also serendipity. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Zaima S.,Nagoya University
Japanese Journal of Applied Physics | Year: 2013

Si ultralarge-scale integration (ULSI) circuits have been developed by downscaling device dimensions on the basis of the concept of scaling, following Moore's law. However, continued downscaling in future ULSI devices will become more difficult because of an increase in the number of technological and economic problems. Therefore, it is necessary to establish a new direction of technological development different from that based on downscaling. In this review, a technology that realizes devices with high performance, integration, and functionality independently of downscaling, is referred to as a postscaling technology, and the current status and future perspectives of postscaling technology are briefly summarized and discussed. © 2013 The Japan Society of Applied Physics. Source

Saka H.,Nagoya University
Journal of Materials Science | Year: 2016

Dislocations in FCC structure are dissociated into two partial dislocations. The dissociation width of a dissociated dislocation controls the mechanical behavior of the alloy. Experimental work using transmission electron microscopy on factors determining the dissociation width is reviewed with special reference to the Suzuki segregation. © 2015, Springer Science+Business Media New York. Source

Okuzumi S.,Nagoya University | Hirose S.,Japan Agency for Marin Earth Science and Technology
Astrophysical Journal | Year: 2011

Turbulence driven by magnetorotational instability (MRI) crucially affects the evolution of solid bodies in protoplanetary disks. On the other hand, small dust particles stabilize MRI by capturing ionized gas particles needed for the coupling of the gas and magnetic fields. To provide an empirical basis for modeling the coevolution of dust and MRI, we perform three-dimensional, ohmic-resistive MHD simulations of a vertically stratified shearing box with an MRI-inactive "dead zone" of various sizes and with a net vertical magnetic flux of various strengths. We find that the vertical structure of turbulence is well characterized by the vertical magnetic flux and three critical heights derived from the linear analysis of MRI in a stratified disk. In particular, the turbulent structure depends on the resistivity profile only through the critical heights and is insensitive to the details of the resistivity profile. We discover scaling relations between the amplitudes of various turbulent quantities (velocity dispersion, density fluctuation, vertical diffusion coefficient, and outflow mass flux) and vertically integrated accretion stresses. We also obtain empirical formulae for the integrated accretion stresses as a function of the vertical magnetic flux and the critical heights. These empirical relations allow us to predict the vertical turbulent structure of a protoplanetary disk for a given strength of the magnetic flux and a given resistivity profile. © 2011. The American Astronomical Society. All rights reserved. Source

MacHida M.N.,Japan National Astronomical Observatory | Inutsuka S.-I.,Nagoya University | Matsumoto T.,Hosei University
Astrophysical Journal | Year: 2011

The formation and evolution of a circumstellar disk in magnetized cloud cores are investigated from a prestellar core stage until ∼104 yr after protostar formation. In the circumstellar disk, fragmentation first occurs due to gravitational instability in a magnetically inactive region, and substellar-mass objects appear. The substellar-mass objects lose their orbital angular momenta by gravitational interaction with the massive circumstellar disk and finally fall onto the protostar. After this fall, the circumstellar disk increases its mass by mass accretion and again induces fragmentation. The formation and falling of substellar-mass objects are repeated in the circumstellar disk until the end of the main accretion phase. In this process, the mass of the fragments remains small, because the circumstellar disk loses its mass by fragmentation and subsequent falling of fragments before it becomes very massive. In addition, when fragments orbit near the protostar, they disturb the inner disk region and promote mass accretion onto the protostar. The orbital motion of substellar-mass objects clearly synchronizes with the time variation of the accretion luminosity of the protostar. Moreover, as the objects fall, the protostar shows a strong brightening for a short duration. The intermittent protostellar outflows are also driven by the circumstellar disk whose magnetic field lines are highly tangled owing to the orbital motion of fragments. The time-variable protostellar luminosity and intermittent outflows may be a clue for detecting planetary-mass objects in the circumstellar disk. © 2011. The American Astronomical Society. All rights reserved. Source

Sirono S.-I.,Nagoya University
Astrophysical Journal | Year: 2011

Icy grain aggregates are formed in the outer region of a protoplanetary nebula. The infall of these aggregates to the central star is due to gas drag, and their temperature increases as the infall proceeds. The icy molecules on the grain move to the neck where the grains get connected through sublimation and condensation of the molecules. This process is called sintering. As the sintering proceeds, the mechanical strength of the neck changes considerably, strongly affecting the collisional evolution of the aggregates. The timescale required for sintering is determined in this study, based on which the region where the sintering proceeds within a prescribed timescale is obtained. It is found that the region covers a substantial fraction of the protoplanetary nebula, and the location of the region depends on the temperature distribution inside the nebula. If the aggregate is stirred up and the temperature of the aggregate increases temporally, the sintering region spreads to the whole nebula. © 2011. The American Astronomical Society. All rights reserved. Source

Aleksic B.,Nagoya University
Molecular Psychiatry | Year: 2016

Recent schizophrenia (SCZ) studies have reported an increased burden of de novo copy number variants (CNVs) and identified specific high-risk CNVs, although with variable phenotype expressivity. However, the pathogenesis of SCZ has not been fully elucidated. Using array comparative genomic hybridization, we performed a high-resolution genome-wide CNV analysis on a mainly (92%) Japanese population (1699 SCZ cases and 824 controls) and identified 7066 rare CNVs, 70.0% of which were small (<100 kb). Clinically significant CNVs were significantly more frequent in cases than in controls (odds ratio=3.04, P=9.3 × 10-9, 9.0% of cases). We confirmed a significant association of X-chromosome aneuploidies with SCZ and identified 11 de novo CNVs (e.g., MBD5 deletion) in cases. In patients with clinically significant CNVs, 41.7% had a history of congenital/developmental phenotypes, and the rate of treatment resistance was significantly higher (odds ratio=2.79, P=0.0036). We found more severe clinical manifestations in patients with two clinically significant CNVs. Gene set analysis replicated previous findings (e.g., synapse, calcium signaling) and identified novel biological pathways including oxidative stress response, genomic integrity, kinase and small GTPase signaling. Furthermore, involvement of multiple SCZ candidate genes and biological pathways in the pathogenesis of SCZ was suggested in established SCZ-associated CNV loci. Our study shows the high genetic heterogeneity of SCZ and its clinical features and raises the possibility that genomic instability is involved in its pathogenesis, which may be related to the increased burden of de novo CNVs and variable expressivity of CNVs.Molecular Psychiatry advance online publication, 31 May 2016; doi:10.1038/mp.2016.88. © 2016 Macmillan Publishers Limited Source

In this study, we developed an integrated method for classifying micro-landforms and flood hazard zones based on a geomorphological approach utilizing Shuttle Radar Topographic Mission (SRTM) and LANDSAT ETM + (Enhanced Thematic Mapper Plus) data combined with field investigation. Micro-landform units on an alluvial plain were classified in relation to flood conditions by integrating an SRTM digital elevation model (DEM) with spectral characteristics from a pair of LANDSAT images from dry and flood seasons. In addition, the LANDSAT ETM + band4-band3 of the flood season image was calculated to identify moist surfaces. Next, a flood hazard zonation map was generated by categorizing geomorphological features and the average elevation of each landform into flood hazard classes. Then, three-dimensional (3D) diagrams of the composed maps were produced using GRASS 6.3 to visualize the geomorphology and flooding risk. The results were validated using field surveys, topographic maps and past inundation images. This case study was undertaken for the Thu Bon alluvial plain, central Vietnam. The findings of this study revealed a close interaction between the geomorphological characteristics of this region and flood conditions. Flooding and sedimentation mechanisms cause dynamic formations of fluvial and coastal landforms, and these geomorphological features in turn affect flood hazard. Furthermore, 43.34% of the area of this plain is classified as having a very high or high flood hazard in lowland areas and a flash flood hazard in higher areas. © 2011 Elsevier Ltd. Source

Suzuki T.K.,Nagoya University
Earth, Planets and Space | Year: 2012

By using our previous results of magnetohydrodynamical simulations for the solar wind from open flux tubes, I discuss how the solar wind in the past is different from the current solar wind. The simulations are performed in fixed one-dimensional super-radially open magnetic flux tubes by inputing various types of fluctuations from the photosphere, which automatically determines solar wind properties in a forward manner. The three important parameters which determine physical properties of the solar wind are surface fluctuation, magnetic field strengths, and the configuration of magnetic flux tubes. Adjusting these parameters to the sun at earlier times in a qualitative sense, I infer that the quasi-steady-state component of the solar wind in the past was denser and slightly slower if the effect of the magneto-centrifugal force is not significant. I also discuss effects of magneto-centrifugal force and roles of coronal mass ejections. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS). Source

Nakamichi N.,RIKEN | Nakamichi N.,Nagoya University
Plant and Cell Physiology | Year: 2011

A wide range of biological processes exhibit circadian rhythm, enabling plants to adapt to the environmental day-night cycle. This rhythm is generated by the so-called 'circadian clock'. Although a number of genetic approaches have identified >25 clock-associated genes involved in the Arabidopsis clock mechanism, the molecular functions of a large part of these genes are not known. Recent comprehensive studies have revealed the molecular functions of several key clock-associated proteins. This progress has provided mechanistic insights into how key clock-associated proteins are integrated, and may help in understanding the essence of the clock's molecular mechanisms. © 2011 The Author. Source

Okui Y.,Tokyo Institute of Technology | Han M.,Tokyo Institute of Technology | Han M.,Nagoya University
Chemical Communications | Year: 2012

We created light-directed dynamic spheres based on simple azobenzene monomers showing (i) a high yield of reversible trans ↔ cis photoisomerization and (ii) noticeable phase transition from crystalline to isotropic states under UV light irradiation at ambient temperature. © 2012 The Royal Society of Chemistry. Source

Shimokawa J.,Nagoya University
Tetrahedron Letters | Year: 2014

Divergent strategy in natural product synthesis allows the comprehensive synthesis of family natural products. Efficient formulation of this idea requires the biosynthetic/biosynthesis-inspired insight toward the well-orchestrated design of a pluripotent late-stage intermediate, in concomitant with the applicability of the intermediates for versatile transformations. This digest focuses on the actual applications of those strategies in natural product synthesis with an emphasis on the recipes for the choice of the common intermediates. © 2014 The Author. Published by Elsevier Ltd. Source

Endogenous electrophiles, such as α,β-unsaturated aldehydes and ketones generated during lipid peroxidation, exhibit a facile reactivity with proteins, generating a variety of intra and intermolecular covalent adducts. It has been postulated that these host-derived, modified proteins with electrophiles, which constitute the products of diverse classes of oxidative reactions, represent damage-associated molecular patterns (DAMPs). The DAMPs, that occur in vivo, can be a ligand of multiple proteins, which in turn, may lead tothe profound innate and adaptive immune responses and mediate homeostatic functions consequent to inflammation and cell death. © 2013 The Author. Source

Okano K.,Tohoku University | Tokuyama H.,Tohoku University | Fukuyama T.,Nagoya University
Chemical Communications | Year: 2014

Herein, we review copper-mediated aromatic amination reactions including the classical Ullmann coupling and the recently developed mild aryl amination with an effective ligand as well as the C-H amination reaction. Several applications of intramolecular aryl amination to the syntheses of natural products demonstrate the general applicability of the reaction. This journal is © the Partner Organisations 2014. Source

Takahashi D.,Tohoku University | Morimoto A.,Nagoya University
Progress in Oceanography | Year: 2013

An analysis of a surface flow field in the East China Sea (ECS) obtained by combining satellite altimeter and drifter data provides comprehensive information of its mean field and annual variation. The Taiwan Warm Current, the onshore Kuroshio intrusion, the Kuroshio, the northeastward Kuroshio branch, the northward current west of Kyushu, the Cheju Warm Current, and the Tsushima Warm Current are regarded as persistent currents. Annual variation is a dominant signal in the ECS and is a major component of the seasonal variation. The contribution of the annual variation to the seasonal variation is estimated as 50% over the ECS, and exceeds 70% for the Kuroshio northeast of Taiwan, the Taiwan Warm Current, the Taiwan Strait Warm Current, the onshore Kuroshio intrusion, the northeastward Kuroshio branch, the northward current west of Kyushu, and the Tsushima Warm Current. The annual variation is characterized by propagation of vorticity anomalies from northeast of the Taiwan Strait and in the Tsushima Strait. The vorticity anomaly from northeast of the Taiwan Strait propagates downstream in the northeastward Kuroshio branch along isobaths of about 100. m on the shelf edge. In contrast, the vorticity anomaly in the Tsushima Strait propagates upstream of the Tsushima Warm Current along isobaths of 100-200. m. The propagation of the vorticity anomalies causes the annual variation with a phase difference in the northeastward Kuroshio branch and the northward current west of Kyushu, and the behavior of the vorticity anomalies can be well explained as a first approximation by a dispersion relation of a quasigeostrophic topographic Rossby wave propagating in a mean flow. Generation of the vorticity anomalies from northeast of the Taiwan Strait and in the Tsushima Strait appears to be closely related to the annual variation of the Kuroshio's current speed northeast of Taiwan and of volume transport through the Tsushima Strait, respectively. © 2013 Elsevier Ltd. Source

Osada K.,Nagoya University
Atmospheric Research | Year: 2013

The volume fraction (ε) of water soluble material in atmospheric aerosol particles is an important parameter related to their hygroscopicity and activation processes to form cloud and ice particles. To estimate ε of coarse dust particles, confocal scanning laser microscope was applied to measure the volume difference of individual particles before and after water dialysis directly. Individual particles (sphere equivalent diameter approx. 1-8. μm) of Asian reference dusts (CJ1 and CJ2) and atmospheric coarse particles during four Asian dust events were analyzed to ascertain ε. Median values of ε for CJ1 and CJ2 were, respectively, 29% and 13% with no size trend. Median values of ε for coarse aerosol particles during four dust events were 18-42%, which show nearly pure (low ε) to aged (higher ε possibly attributable to addition of sea salts and other water soluble salts) Asian dust. Dust particles with high ε are potentially important for acting as giant CCN. Therefore the aging of dust particles during transport might enhance the number of giant CCN over the North Pacific. © 2013 Elsevier B.V. Source

Kazama M.,Tohoku University | Noda T.,Nagoya University
Soils and Foundations | Year: 2012

The 2011 off the Pacific Coast of Tohoku Earthquake, which occurred on March 11, 2011, caused enormous damage, particularly to the strip of land along the Pacific Ocean from the Tohoku Region to the Kanto Region, due to seismic motion and the tsunami it triggered. This report presents an outline of the earthquake and summarizes the associated seismic damage to social infrastructure facilities. © 2012 The Japanese Geotechnical Society. Source

Terakawa T.,Nagoya University | Miller S.A.,University of Bonn | Deichmann N.,ETH Zurich
Journal of Geophysical Research: Solid Earth | Year: 2012

[1] We analyzed 118 well-constrained focal mechanisms to estimate the pore fluid pressure field of the stimulated region during the fluid injection experiment in Basel, Switzerland. This technique, termed focal mechanism tomography (FMT), uses the orientations of slip planes within the prevailing regional stress field as an indicator of the fluid pressure along the plane at the time of slip. The maximum value and temporal change of excess pore fluid pressures are consistent with the known history of the wellhead pressure applied at the borehole. Elevated pore fluid pressures were concentrated within 500 m of the open hole section, which are consistent with the spatiotemporal evolution of the induced microseismicity. Our results demonstrate that FMT is a robust approach, being validated at the meso-scale of the Basel stimulation experiment. We found average earthquake triggering excess pore fluid pressures of about 10 MPa above hydrostatic. Overpressured fluids induced many small events (M < 3) along faults unfavorably oriented relative to the tectonic stress pattern, while the larger events tended to occur along optimally oriented faults. This suggests that small-scale hydraulic networks, developed from the high pressure stimulation, interact to load (hydraulically isolated) high strength bridges that produce the larger events. The triggering pore fluid pressures are substantially higher than that predicted from a linear pressure diffusion process from the source boundary, and shows that the system is highly permeable along flow paths that allow fast pressure diffusion to the boundaries of the stimulated region. © 2012. American Geophysical Union. Source

Kneeshaw S.,University of Edinburgh | Gelineau S.,University of Edinburgh | Tada Y.,Nagoya University | Loake GaryJ.,University of Edinburgh | Spoel StevenH.,University of Edinburgh
Molecular Cell | Year: 2014

In eukaryotes, bursts of reactive oxygen and nitrogen species mediate cellular responses to the environment by modifying cysteines of signaling proteins. Cysteine reactivity toward nitric oxide (NO) leads to formation of S-nitrosothiols (SNOs) that play important roles in pathogenesis and immunity. However, it remains poorly understood how SNOs are employed as specific, reversible signaling cues. Here we show that in plant immunity the oxidoreductase Thioredoxin-h5 (TRXh5) reverses SNO modifications by acting as a selective protein-SNO reductase. While TRXh5 failed to restore immunity in gsnor1 mutants that display excessive accumulation of the NO donor S-nitrosoglutathione, it rescued immunity in nox1 mutants that exhibit elevated levels of free NO. Rescue by TRXh5 was conferred through selective denitrosylation of excessive protein-SNO, which reinstated signaling by the immune hormone salicylic acid. Our data indicate that TRXh5 discriminates between protein-SNO substrates to provide previously unrecognized specificity and reversibility to protein-SNO signaling in plant immunity. © 2014 Elsevier Inc. All rights reserved. Source

Kojima S.,Nagoya University
Current Opinion in Microbiology | Year: 2015

Many motile bacteria swim by rotating their motility organ, the flagellum. Rotation of the flagellum is driven by a motor at its base, and torque is generated by the rotor-stator interaction coupled with the specific ion flow through the channel in the stator. Because the stator works as an energy-conversion complex in the motor, understanding the functional mechanism of the stator is critically important. But its characterization has been hampered due to the difficulty in isolating the functional stator complex from the membrane. Recently, successful new approaches for studying the stator have been reported that reveal its novel properties. Two of those, visualization of the in vivo behavior of stator units using fluorescently tagged proteins and structure-guided functional analyses of the soluble region in the stator, are summarized in this short review. © 2015 Elsevier Ltd. Source

Kurita N.,Nagoya University
Journal of Geophysical Research: Atmospheres | Year: 2013

In tropical regions, the empirical negative relationship between the isotopic content of precipitation and rainfall amount, known as the "amount effect", has been used as a rationale for paleohydroclimate reconstruction from isotope records. However, there is still no comprehensive physical explanation for this empirical effect. Here we reconsider the well-known amount effect using newly available isotope data for both surface water vapor and precipitation obtained from shipboard observations. In this study, we hypothesized that stratiform rainfall associated with mesoscale convective systems (MCSs) is a key process in reducing tropical water isotopic concentrations and tested this hypothesis with an idealized MCS model. Our conceptual model reasonably accounted for several observed features and indicated that isotopic reductions in tropical oceanic regions reflect a precipitating system's change. Relatively high isotope ratios corresponded to disorganized convection. On the other hand, MCSs were characterized by lower isotope ratios with increasing stratiform area. In addition, the amplitude of this isotopic depletion was related to the scale of the precipitation system. The lowest isotopic ratios were observed during the passage of large-scale disturbances - corresponding to the Madden-Julian oscillation convective envelope - in which MCSs are embedded. This means that the frequent appearance of MCSs results in further decreases in the isotopic ratio of surface vapor and precipitation. From this, we conclude that the amount effect can be interpreted as the development of a precipitation system from an isolated convection cell into a large-scale system containing several MCSs and that past large-scale convective activity can be reconstructed from isotope records. Key Points Provide new data for water isotopes over the oceanProvide a key process for controlling isotopic variation in tropical waterPropose new interpretation of the ©2013. American Geophysical Union. All Rights Reserved. Source

Masunaga H.,Nagoya University
Journal of the Atmospheric Sciences | Year: 2013

The thermodynamic variability associated with moist convection over tropical oceans is analyzed by making use of a variety of satellite sensors including radars, an infrared and microwave sounder unit, and a microwave radiometer and scatterometer aboard different platforms. Satellite measurements of atmospheric parameters including air temperature, water vapor, cumulus cloud cover, and surface wind are composited with respect to the temporal lead or lag from Tropical Rainfall Measuring Mission (TRMM)-detected convection to obtain statistically continuous time series on hourly to daily time scales. The Atmospheric Infrared Sounder (AIRS)- observed temperature and humidity profiles, representing cloud-cleared sounding, are combined with semitheoretical estimates of in-cloud temperature and humidity to construct the large-scale mean field. Those measurements are ingested to the moisture and thermal budget equations integrated vertically over each layer separated by cloud base. This strategy makes it possible to evaluate the free-tropospheric (FT) convergence of moisture and dry static energy and their vertical flux at cloud base from satellite observations alone. The main findings include the following: 1) vertical moisture transport at cloud base is the dominant source of FT moistening prior to isolated cumulus development while overwhelmed by horizontal moisture convergence for highly organized systems; 2) FT diabatic heating is largely offset on an instantaneous basis; and 3) FT moistening by convective eddies amounts to a half of the total cloud-base moisture flux in the background state, while large-scale mean updrafts modulate the variability of cloud-base flux when highly organized systems develop. The known correlation between congestus clouds and FT moisture before deep convection may be accounted for by large-scale mean moisture updraft rather than congestus eddy moistening. © 2013 American Meteorological Society. Source

Hashimoto C.,Nagoya University | Noda A.,Kozo Keikaku Eng. Inc. | Matsu'ura M.,The Institute of Statistical Mathematics of Tokyo
Geophysical Journal International | Year: 2012

The M w 9.0 off northeast Japan (Tohoku-oki) earthquake occurred on 2011 March 11 at the interface between the North American (NA) and Pacific (PA) plates. The occurrence of interplate earthquakes can be regarded as the sudden release of tectonic stress accumulated by the interseismic gradual increase of slip deficit in source regions. The inversion analysis of GPS velocity data for a seismically calm period (1996-2000) before the Tohoku-oki earthquake has revealed the existence of five remarkable slip-deficit zones distributed on the NA-PA plate interface along the southern Kuril-Japan trench. We analysed coseismic GPS displacement data for the Tohoku-oki earthquake with the same inversion method, and obtained the bimodal distribution of coseismic slip spreading over the southern two, Miyagi-oki and Fukushima-oki, interseismic slip-deficit zones. The maximum slip is 32 m for the Miyagi-oki slip-deficit zone but only 7 m for the Fukushima-oki slip-deficit zone. The extraordinarily large coseismic slip in the Miyagi-oki slip-deficit zone, where ordinarily large earthquakes with about 3 m coseismic slips have repeated every 40 yr in the past two centuries, suggests the total rupture of a 300-km-long basement asperity underlying much smaller-scale local asperities. © 2012 The Authors Geophysical Journal International © 2012 RAS. Source

Komatsu M.,Nagoya University
Nuclear and Particle Physics Proceedings | Year: 2016

The OPERA experiment is designed to prove neutrino oscillations in the νμ to ντ channel through the direct observation of the tau lepton in tau neutrino charged current interactions. The experiment has accumulated data for five years, from 2008 to 2012, with the CERN Neutrinos to Gran Sasso (CNGS), an almost pure νμ beam. In the last two years, a very large amount of the data accumulated in the nuclear emulsions has been analyzed. The latest results on oscillations with the increased statistics, which include a fourth tau neutrino candidate event, will be presented. Given the extremely low expected background, this result corresponds to the observation of the oscillation process with a four sigma level significance. © 2015 Elsevier B.V. Source

Figaj M.,Nagoya University
Environmental Economics and Policy Studies | Year: 2010

The factors affecting global environmental aid allocated by Japan, the USA, the World Bank, and the Global Environment Facility (GEF) are examined for the period of 1995-2006. Thirty different political, geographical, developmental, economic, environmental, and national security variables were tested to determine which variables show a strong correlation with environmental aid. Based on regression analysis using aid amounts generated from the OECD creditor reporting system (CRS) database, aid allocation results were derived. Two types of aid distribution patterns were tested: which countries receive aid and which variables affect how much aid they receive. The significant variables in both cases proved to be different. The variables that determined whether a country will receive environmental funds were mostly related to poverty and environmental factors. However, the extent of aid received was primarily determined by economic and environmental concerns. Egypt proved to be an important variable for the USA. Political variables did not play a significant role in environmental aid distribution. © 2010 Springer. Source

Goshima G.,Nagoya University | Kimura A.,National Institute of Genetics
Current Opinion in Cell Biology | Year: 2010

The structure, dynamics, and mechanics of mitotic and meiotic spindles have been progressively elucidated through the advancements in microscopic technology, identification of the genes involved, and construction of theoretical frameworks. Here, we review recent works that have utilized quantitative image analysis to advance our understanding of the complex spindle structure of animal cells. In particular, we discuss how microtubules (MTs) are nucleated and distributed inside the spindle. Accumulating evidence supports the presence of MT-dependent MT generation within the spindle. This mechanism would produce dense arrays of intraspindle MTs with various lengths, which may contribute to efficient spindle assembly and stabilize the metaphase spindle. RNA interference (RNAi) screens with quantitative image analysis led to the identification of the augmin complex that plays a key role in this MT generation process. © 2009 Elsevier Ltd. All rights reserved. Source

An important goal of membrane biology is to define the local heterogeneity of membrane lipid composition. Here we describe a quantitative electron microscopic method that enables the localization of specific membrane lipids at the nanometer scale. The method involves freezing cells rapidly to halt the molecular motion, physically stabilizing membrane molecules in the freeze-fracture replica by the deposition of evaporated platinum and carbon layers and labeling with specific probes for electron microscopic observation. Lipids in both the outer and inner membrane leaflets can thus be labeled, and their distributions can be analyzed quantitatively by statistical methods. A major advantage of this method is that it does not require the expression of artificial probes. Therefore, this method can be applied to any cell in vitro or in vivo, and the whole procedure can be completed in 1-2 d. Source

Matsuda S.,University of Ryukyus | Iryu Y.,Nagoya University
Marine Geology | Year: 2011

The distribution, abundance, composition, and growth history of rhodoliths were investigated based on 222 grab samples and 202 submarine photographs taken from 223 sites arranged at regular intervals and on 13 additional samples (5 dredge and 8 grab samples). These samples were collected at water depths ranging from 15 to 970. m around Okinawa-jima, Ryukyu Islands, Japan. The rhodoliths grow in deep fore-reef to shelf areas at water depths of 50 to 135. m. Where rhodoliths occur, they cover 45% of the sea bottom. The rhodoliths are primarily spheroidal to ellipsoidal in shape (with mean diameters usually less than 8. cm); internally they are primarily composed of nongeniculate coralline algae and an encrusting foraminifer Acervulina inhaerens. The rhodoliths have envelopes of well-preserved, concentric to irregular laminations or, much more commonly, are bored and display various degrees of bioerosion. Constructional voids (primary spaces between encrusters) and borings range from empty to completely filled with unlithified and lithified mixtures of micrites and bioclasts. The bioerosion is more extensive with increasing water depth and is progressively much more pervasive at water depths greater than 90. m. The rhodoliths are covered with nongeniculate coralline algae and A. inhaerens associated with other epilithic skeletal and nonskeletal organisms. The living biotic cover on rhodoliths is relatively great down to water depths ~. 100. m; below this, the cover decreases rapidly with increasing water depth. Rhodoliths with similar size, shape, and composing organisms to those in the Ryukyu Islands are commonly found on deep fore-reef to shelf areas or on the banks and seamounts of tropical reef regions, likely as the combined result of ecological degradation (=decreased number and coverage) of hermatypic corals and the relative predominance of nongeniculate coralline algae and encrusting foraminifers in such areas. The slow accretion rates of rhodoliths (<0.1 mm/year) indicate that their formation is commonly to frequently intermittent, probably because of their burial in the surrounding sediment. © 2011 Elsevier B.V. Source

Sekido Y.,Aichi Cancer Center Research Institute | Sekido Y.,Nagoya University
Cancer Science | Year: 2010

Malignant mesothelioma (MM) is a tumor with poor prognosis associated with asbestos exposure. While it remains to be clarified how asbestos fibers confer genetic/epigenetic alterations and induce cellular transformation in normal mesothelial cells, the understanding of key molecular mechanisms of MM cell development, proliferation, and invasion has progressed. MM shows frequent genetic inactivation of tumor suppressor genes of p16INK4a/. p14ARF and neurofibromatosis type 2 (NF2) which encodes Merlin, and epigenetic inactivation of RASSF1A. However, no frequent mutations of well-known oncogenes such as K-RAS and PIK3CA have been identified. Activation of multiple receptor tyrosine kinases including the epidermal growth factor receptor (EGFR) family and MET, and subsequent deregulations of mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K)-AKT signaling cascades are frequently observed in most MM cells. The tumor suppressive function of Merlin in MM cells is also being investigated by dissecting its possible downstream signaling cascade called the Hippo pathway. Further comprehensive delineation of dysregulated signaling cascades in MM cells will lead to identification of key addiction pathways for cell survival and proliferation of MM cells, which strongly promote establishment of a new molecular target therapy for MM. © 2009 Japanese Cancer Association. Source

Miyoshi Y.,Nagoya University | Kataoka R.,Tokyo Institute of Technology
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2011

The outer radiation belt shows solar cycle variation: the L-shell of the electron flux peak in the outer belt shifts inward during the period between the rising phase and the solar maximum, while it shifts outward between the beginning of the declining phase and the solar minimum. We show a possible mechanism which considers two typical types of magnetic storms categorized in accordance with solar wind drivers, namely coronal mass ejections (CMEs) and corotating interaction regions (CIRs). Large flux enhancements at the inner portion of the outer belt tend to occur during the recovery phase of great storms driven by CMEs, while large flux enhancements at the outer portion and at geosynchronous orbit tend to occur during the recovery phase of relatively moderate storms driven by CIRs. High-speed coronal hole streams which do not always cause large magnetic storms also effectively enhance the electron flux enhancement at the outer portion and in geosynchronous orbit. In this framework, the plasmapause always plays an important role in both flux enhancement and flux loss in the outer belt. The average plasmapause position depends on the storm amplitude, and the plasmapause reaches closest to the Earth during great storms driven by CMEs. CMEs themselves and CME-driven storms occur during maximum periods of solar activity, while CIRs themselves and CIR-driven storms occur during the solar declining phase. The observed long-term variations of the outer belt can therefore be understood in terms of their dependence on the large-scale interplanetary structures, varying depending on the phase of the solar cycle. © 2010 Elsevier Ltd. Source

Neurons are highly polarized cells that have structurally distinct processes-the axons and dendrites-that differentiate from common immature neurites. In cultured hippocampal neurons, one of these immature neurites stochastically initiates rapid extension and becomes an axon, whereas the others become dendrites. Various extracellular and intracellular signals contribute to axon specification; however, the specific intracellular pathways whereby particular extracellular stimuli lead to axon specification remain to be delineated. Here, we found that the neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) were required for axon specification in an autocrine or a paracrine fashion. Using local application with a micropipette to selectively stimulate individual neurites, we found that stimulation of a selected neurite by BDNF or NT-3 induced neurite outgrowth and subsequent axon formation. NT-3 induced a rapid increase in calcium ions (Ca(2+)) in an inositol 1,4,5-trisphosphate (IP(3))-dependent fashion as well as local activation of the Ca(2+) effector Ca(2+)/calmodulin-dependent protein kinase kinase (CaMKK) in the growth cone. Inhibition of neurotrophin receptors or CaMKK attenuated NT-3-induced axon specification in cultured neurons and axon formation in cortical neurons in vivo. These results identify a role for IP(3)-Ca(2+)-CaMKK signaling in axon specification. Source

Chaston C.C.,University of California at Berkeley | Seki K.,Nagoya University
Journal of Geophysical Research: Space Physics | Year: 2010

We simulate the 3-D evolution of a thin current sheet as it impinges on the ionosphere from a magnetospheric source in a manner analogous to that which may occur during the onset of an auroral substorm. We consider two scenarios: one in which electron inertia alone acts to allow motion between the plasma and the geomagnetic field, and a second where a resistive layer at the interface between the ionosphere and magnetosphere is included. These two scenarios in our fluid model are intended to represent what have become known as "Alfvnic" and "Quasi-static" or "Inverted-V" aurora, respectively. In the absence of resistivity the evolution is shown to be driven by a combination of Kelvin-Helmholtz and tearing instabilities leading to vortices similar to folds and the eventual break-up of the planar arc into distorted fine-scale sheets and filamentary currents. The later stage of this evolution is driven by an instability on the steep transverse current gradients created by the former instabilities. With a resistive layer present the K-H instability dominates leading to the formation of auroral curls. We show how these evolutionary processes can be ordered based on the ratio of the transverse electric and magnetic fields (△EX/△BY) across the current sheet relative to the Alfvn speed, and demonstrate how the evolution is dependent on wave reflection from the topside ionosphere. © 2010 by the American Geophysical Union. Source

Suzuki R.,Nagoya University
International Journal of Hematology | Year: 2010

Extranodal NK/T cell lymphoma, nasal type (ENKL) with advanced stage and aggressive NK-cell leukemia (ANKL) are highly aggressive neoplasms with a dismal clinical outcome. It is well known that P-glycoprotein, which is a product of MDR1 gene and related to multi-drug resistance, is expressed on tumor cells of ENKL or ANKL. This is a major reason for the refractoriness to conventional chemotherapeutic regimens for malignant lymphoma containing anthracycline. However, recent studies have identified that several drugs including l-asparaginase, methotrexate and alkylators show excellent effect for these tumors. The SMILE (steroid, methotrexate, ifosfamide, l-asparaginase and etoposide) regimen is one of the promising regimens for advanced or relapsed/refractory ENKL, but its myelotoxicity is strong. ANKL needs another treatment strategy because of a systemic disease progression and extensive organ insufficiency. Optimal treatment scheme using such effective agents for these unfavorable NK-cell tumors should further be explored. © 2010 The Japanese Society of Hematology. Source

Niimi T.,Nagoya University
Methods in Molecular Biology | Year: 2012

Leishmania tarentolae is a trypanosomatid protozoan parasite of the gecko, and has been established as a new eukaryotic expression system for the production of recombinant proteins. It seems that a protozoan parasite is a curious choice as the expression host; however, Trypanosomatidae are rich in glycoproteins with a pattern of glycosylation closely related to those in mammals and higher vertebrates. Thus, one of the main advantages of a L. tarentolae expression system is the mammalian-type posttranslational modification of target proteins. Although there are few examples of recombinant protein expression using this system, it can be an attractive alternative to using mammalian cells. This chapter presents an overview of the newly developed protein expression system based on L. tarentolae. © 2012 Springer Science+Business Media, LLC. Source

Results of recent studies on the model higher plant Arabidopsis thaliana have led us to learn about the generality and versatility of two-component systems (TCS) in eukaryotes. In the plant, TCS are crucially involved in certain signal transduction mechanisms underlying the regulation of plant development in response to a subset of plant hormones, namely, cytokinin and ethylene. Results of extensive plant genomics revealed that these hormone-responsive TCS are evolutionarily conserved in many other plants, including mosses, grasses, crops, and trees. In particular, the conserved cytokinin-responsive TCS is typical in the sense that the signaling pathway consists of cytokinin-receptor histidine kinases (HK), histidine-containing phosphotransfer (HPt) factors, and downstream phosphoaccepting response regulators (RR), which together act as His-to-Asp multistep phosphorelay components, and which together modulate the downstream network of cytokinin-responsive gene regulation. The ethylene-responsive TCS is atypical in that ethylene-receptor HKs appear to directly interact with the downstream mitogen-activated protein kinase (MAPK) cascade. The ethylene-responsive HKs have already been introduced in the previous edition of Methods in Enzymology [Schaller, G. E., and Binder, B. M. (2007). Biochemical characterization of plant ethylene receptors following transgenic expression in yeast. Methods Enzymol. 422, 270-287]. Hence, here we focus on the cytokinin-receptor HKs, which are capable of functioning in microorganisms, such as Escherichia coli and Saccharomyces cerevisiae. Some versatile protocols useful for analyzing plant TCS factors by employing these microorganisms will be introduced. Copyright © 2010 Elsevier Inc. All rights reserved. Source

Kawabe T.,Nagoya University
Nagoya journal of medical science | Year: 2011

The CD40 ligand/CD40 pathway is widely recognized for its prominent role in immune regulation and homeostasis. CD40, a member of the tumor necrosis factor receptor family, is expressed by antigen-presenting cells, as well as non-immune cells and tumors. The engagement of the CD40 and CD40 ligands, which are transiently expressed on T cells and other non-immune cells under inflammatory conditions, regulates a wide spectrum of molecular and cellular processes, including the initiation and progression of cellular and humoral adaptive immunity. Based on recent research findings, the engagement of the CD40 with a deregulated amount of CD40 ligand has been implicated in a number of inflammatory diseases. We will discuss the involvement of the CD40 ligand/CD40 interaction in the pathophysiology of inflammatory diseases, including autoimmune diseases, atherothrombosis, cancer, and respiratory diseases. Source

Akiyama M.,Nagoya University
Nagoya journal of medical science | Year: 2011

Research into the molecular genetics and pathomechanisms of ichthyoses have advanced considerably, resulting in the identification of several causative genes and molecules underlying the disease. In 2009, the First Ichthyosis Consensus Conference was held to establish a consensus for the nomenclature and classification of inherited ichthyoses, by which an international consensus for the classification of inherited ichthyosis was achieved. In this review, the pathogeneses of various ichthyoses are summarized based on their revised classification and terminology. Skin barrier defects are involved in the pathogenesis of various types of ichthyosis. The known causative molecules underlying ichthyosis include ABCA12, lipoxygenase-3, 12R-lipoxygenase, CYP4F22, ichthyin and steroid sulfatase, all of which are thought to be related to the intercellular lipid layers. ABCA12 is a known keratinocyte lipid transporter associated with lipid transport in lamellar granules and a loss of ABCA12 function leads to defective lipid transport in the keratinocytes, resulting in the most severe, harlequin ichthyosis phenotype. Other causative molecules for ichthyoses are transglutaminase 1, keratins and filaggrin. Transglutaminase 1 plays a role in cornified cell envelope formation. Keratins 1, 10 and 2 are involved in the keratin network of suprabasal keratinocytes and filaggrin is essential for the formation of keratohyalin granules. It is important to obtain information concerning genetic defects and to elucidate ichthyotic disease pathomechanisms for the establishment of an effective therapy and beneficial genetic counseling, including a prenatal diagnosis for families affected by ichthyotic disease. Source

Sasaki K.,Hokkaido University | Takada N.,Nagoya University
Pure and Applied Chemistry | Year: 2010

The irradiation of an intense laser pulse onto a solid target immersed in liquid produces dense plasma. The plasma produced by liquid-phase laser ablation has unique features at high pressure and temperature, which are never realized by liquid-phase discharges. Another unique characteristic of liquid-phase laser ablation is the formation of a cavitation bubble. This article reports the fundamental aspects of liquid-phase laser-ablation plasmas, cavitation bubbles, and the formation processes of nanoparticles, together with some applications of liquid-phase laser ablation. © 2010 IUPAC. Source

Tokita K.,Nagoya University
Population Ecology | Year: 2015

We review the history and recent progress of the analytical theories of a random community models. In particular, we focus on a global stability analysis of replicator equations with random interactions and species abundance distributions based on statistical mechanics. © 2015, The Society of Population Ecology and Springer Japan. Source

Ichie T.,Kochi University | Nakagawa M.,Nagoya University
Ecological Research | Year: 2013

Limitations in resources are considered to be important in mass-fruiting trees, based on the speculation that they need to consume a large amount of stored resources in a very short period. To test this hypothesis, we studied the total reproductive costs per individual of the tree Dryobalanops aromatica (Dipterocarpaceae), and the dynamics of stored mineral nutrients, specifically nitrogen, phosphorus, and potassium; we then estimated the contribution of each of the stored resources to reproduction in a lowland dipterocarp forest in Sarawak, Malaysia. D. aromatica is an emergent and masting tree species, and it produced a large amount of mature fruit in a masting period running 2001-2002. The dynamics patterns were markedly different for each of the stored nutrients. The phosphorus concentration clearly decreased in the branch, stem and root during reproduction, but nitrogen fluctuated by only a small amount in any organ during this period. The potassium concentration fell in all organs during flowering, but even increased during fruit development. Stored phosphorus accounted for 67. 7% of the total phosphorus requirements for reproduction, but nitrogen accounted for only 19. 7%. Stored potassium did not appear to contribute anything, at least to fruit production. Our results suggest that D. aromatica supplies phosphorus needed for reproduction mainly from stored resources in the tree, unlike nitrogen or potassium. The accumulation of phosphorus could be the decisive factor in the occurrence and frequency of mast reproduction in the relatively poor soil conditions prevailing in the tropical rain forests of Southeast Asia. © 2011 The Ecological Society of Japan. Source

Kaneyoshi T.,Nagoya University
Physica B: Condensed Matter | Year: 2015

The phase diagram and magnetizations in an Ising nanowire based on the core-shell concept are examined by using the effective-field theory with correlations. The nanowire is constructed from the ferromagnetic core and the spin glass like disordered surface shell. The effects of surface disorder and interlayer coupling between the core and the shell on the magnetic properties are examined. We have found a lot of novel phenomena in them. © 2015 Elsevier B.V. All rights reserved. Source

S Miyachi E.,Nagoya University
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences | Year: 2011

Dural arteriovenous fistula (DAVF) can be separated into two types: DAVF which drains through an affected sinus (sinus type) and DAVF with direct reflux to the cortical vein (non-sinus type). The present report attempted to clarify the mechanism of formation and development of DAVF focusing on the emissary vein (EV) hypothesis.First, inflammation occurs at the penetrating point of the EV on the dura due to idiopathic or secondary causes. Local inflammatory reactions induce vessel dilatation and neovascularization, and subsequently create arteriovenous (AV) connections on the arteriole level. Although EV communicating with dural arteries might play a role as draining routes at first, they start to degrade due to compression of enlarged emissary arteries or to a hemodynamic shift to the drainage pathway of least resistance. Following the occlusion of drainage pathway through EV into the sinus or cortical veins may form, resulting in clinically detectable DAVF. The AV shunt then expands to the surrounding dura associated with recruitment of feeders from distant sites induced by expression of angiogenetic factors and a shift in the hemodynamic balance. In sinus type DAVF, the sinus is progressively compartmentalized and finally occludes due to thrombogenesis with activated coagulopathy or to hemodynamic hypertrophy of the sinus wall. This progression results in the mature, aggressive DAVF with drainage impairments. Previous mechanistic hypotheses focusing on sinus hypertension and sinus thromboses cannot explain the pathogenesis of non-sinus type of DAVF. Although the etiology of DAVF may be concerned by the thrombo-occlusive change of sinus, the unique theory presented in this report may enable an understanding of the common etiology of both types of DAVF. Source

Murohara T.,Nagoya University
Microvascular Research | Year: 2010

The presence of circulating endothelial repopulating cells in the adult human peripheral blood has been proposed since long time ago. In the late 1990s, the putative endothelial progenitor cells (EPCs) were first identified and reported by Asahara and co-workers. Since then, a number of studies have demonstrated that these cells are derived from bone marrow and induce microvascular vasculogenesis and re-endothelialization of injured vessels. Meantime, human umbilical cord blood also gained much attention for the reason of possible additional source to obtain EPCs since cord blood has been shown to contain more number of active hematopoietic stem cells as compared to adult peripheral blood. This review summarizes the aspect of human cord blood-derived EPCs with special focuses into their identity and future clinical application. © 2009 Elsevier Inc. Source

Kawamura J.,Waseda University | Omura Y.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

Recently, the ATLAS and CMS collaborations report excesses around 750 GeV in the diphoton channels. This might be the evidence which reveals new physics beyond the Standard Model. In this paper, we consider models with a 750 GeV scalar and vectorlike particles, which couple each other through Yukawa couplings. The decay of the scalar to diphoton is given by the loop diagrams involving the extra colored particles. We investigate not only the setup required by the excesses, but also the LHC constraints, especially concerned with the vectorlike particles. In our scenario, the extra colored particles decay to quarks and a dark matter (DM) via Yukawa couplings. Then, the signals from the vectorlike particles are dijet, bb and/or tt with large missing energy. We discuss two possibilities for the setups: One is a model with vectorlike fermions and a scalar DM, and the other is a model with vectorlike scalars and a fermionic DM. We suggest the parameter region favored by the excess in each case, and study the constraints based on the latest LHC results at s=8 TeV and 13 TeV. We conclude that the favored region is almost excluded by the LHC bounds, especially when the 750 GeV scalar dominantly decays to DMs. The mass differences between the vectorlike particles and the DM should be less than O(100) GeV [O(10) GeV] to realize the large diphoton signal and the large decay width, if the extra colored particle only decays to a top (bottom) quark and a dark matter. Otherwise, these scenarios are already excluded by the latest LHC results. © 2016 American Physical Society. Source

Natuhara Y.,Nagoya University
Ecological Engineering | Year: 2013

This paper reviews research on the ecosystem services or multifunctionality of paddy rice cultivation in Japan, focusing on biodiversity as a basis for ecosystem services, with the aim of describing the current status and impact of the subject and exploring options for sustainable practices. Ecosystem services provided by paddy fields include; groundwater recharge, production of non-rice foods, flood control, soil erosion and landslide prevention, climate-change mitigation, water purification, culture and landscape, and support of ecosystems and biodiversity. Among these services, the value of services that regulate ecosystem functions was estimated to be US$ 72.8 billion in Japan. More than 5000 species have been recorded in paddy fields and the surrounding environment. Because paddy fields are artificially disturbed by water level management, plowing, and harvest, most species move between paddy fields and the surrounding environment. The linkage between paddy fields and the associated environment plays an important role in biodiversity. Two changes that have affected the ecosystem of paddy fields are modernization and abandonment of farming. Satoyama, a traditional socio-ecological production landscape, which provided a functional linkage between paddy fields and the associated environment has lost its functions. Biodiversity-conscious rice farming has been promoted by collaborations among farmers, consumers and governments. Biodiversity certification programs are successful examples of biodiversity-conscious framing. In these programs incentives include direct payments and/or premium prices paid by consumers, as well as farmers willingness to improve the safety of food and environment. © 2012 Elsevier B.V. Source

Kobayashi K.,Nagoya University
Journal of Spinal Disorders and Techniques | Year: 2015

STUDY DESIGN:: The efficacy of use of a drain tip culture for early detection of surgical-site infection (SSI) was investigated in 329 patients after spinal surgery. OBJECTIVE:: To examine the efficacy of a wound drain tip culture for detection of SSI in spinal surgery. SUMMARY OF BACKGROUND DATA:: A complication of SSI after spinal surgery has high associated morbidity and mortality, and is often difficult to treat. MATERIALS AND METHODS:: The subjects were patients who underwent spinal surgery at our institution between January 2010 and March 2013. All subjects were treated with antimicrobial prophylaxis based on evidence-based guidelines and were followed for at least 6 months after surgery. Data from culture studies using the distal tip of the wound drain were used for analysis. RESULTS:: Drain tip cultures were positive in 34 cases and there were 19 SSIs. Ten of the 34-tip culture-positive wounds developed SSI. Drain tip cultures had a sensitivity of 52%, specificity of 92%, positive predictive value (PPV) of 29%, and negative predictive value of 97% for predicting a wound infection. The association between a positive suction tip culture and wound infection was significant (P<0.05). The PPV for SSI was 60% in cases in which methicillin-resistant bacteria were detected in a drain tip, and the SSI rate in these cases differed significantly compared with those with non–methicillin-resistant bacteria (P=0.01). CONCLUSIONS:: A drain tip culture is useful for early detection of SSI caused by methicillin-resistant bacteria. © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source

Maki M.,Nagoya University
FEBS Journal | Year: 2012

Apparently unrelated systems often merge and work together to achieve diverse biological functions. This minireview series was aimed to unveil new facets of ESCRTs and calpains: ESCRT proteins in MVB formation, virus budding and cell division; the ambient pH sensing and adaptation in association with ESCRTs and the calpain system; evolutionary and physical linkage between calpains and PEF proteins © 2012 The Author Journal compilation © 2012 FEBS. Source

Koyama T.,University of Tokyo | Koyama T.,Nagoya University | Suemoto T.,University of Tokyo
Reports on Progress in Physics | Year: 2011

The F center in alkali halides is a well-known prototype of a strongly coupled localized electron-phonon system. This colour center is one of the long studied targets in the field of photophysics because it is simple but rich in variety. Steady-state spectroscopy, such as modulation spectroscopy and Raman scattering spectroscopy, has elucidated the strength of the electron-phonon coupling in the (meta-)stable state, i.e. the ground state and the relaxed excited state. Picosecond spectroscopy has improved understanding of the state mixing in the transient state. Owing to recent developments of ultrafast lasers with pulse widths shorter than oscillation periods of phonons, it has been possible to perform real-time observation of lattice vibration, and the understanding of the transient state has been remarkably expanded. In this paper, we review early and present studies on dynamics of electron-phonon coupling at the F center, especially recent real-time observations on the dynamics of nuclear wave packets in the excited state of the F center in KI, KBr, KCl and RbCl. These real-time observations reveal (i) spatial extension of the electronic wave function of a trapped electron, (ii) the difference between the coupled phonons in the ground state and the excited state, (iii) diabatic transition between the adiabatic potential energy surfaces and (iv) anharmonicity of the potential energy surface. © 2011 IOP Publishing Ltd. Source

Ozawa M.,Nagoya University
Foundations of Physics | Year: 2011

The recently established universal uncertainty principle revealed that two nowhere commuting observables can be measured simultaneously in some state, whereas they have no joint probability distribution in any state. Thus, one measuring apparatus can simultaneously measure two observables that have no simultaneous reality. In order to reconcile this discrepancy, an approach based on quantum logic is proposed to establish the relation between quantum reality and measurement. We provide a language speaking of values of observables independent of measurement based on quantum logic and we construct in this language the state-dependent notions of joint determinateness, value identity, and simultaneous measurability. This naturally provides a contextual interpretation, in which we can safely claim such a statement that one measuring apparatus measures one observable in one context and simultaneously it measures another nowhere commuting observable in another incompatible context. © 2010 Springer Science+Business Media, LLC. Source

Itami K.,Nagoya University
Chemical Record | Year: 2011

This account highlights elements of our efforts to explore new functionalization chemistry of fullerenes using molecular catalysts since 2006. These endeavors have led to the development of new reactions such as (i) organoboron addition to fullerenes, (ii) C-H bond allylation and arylation of organo(hydro)fullerenes, (iii) C-H/C-C bond cleavage of alkynyl(hydro) fullerenes, (iv) regioselective tetraallylation of fullerenes, (v) double nucleophilic substitution of aziridinofullerene, and (vi) [2 + 2] cycloaddition of aziridinofullerene with alkynes. These works not only highlight the potential of molecular catalysis for fullerene functionalization, but also unlock opportunities for markedly different strategies in nanocarbon synthesis. © 2011 The Chemical Society of Japan and Wiley-VCH, Weinheim. Source

Tamasaku K.,RIKEN | Tamasaku K.,Japan Science and Technology Agency | Sawada K.,RIKEN | Nishibori E.,Nagoya University | Ishikawa T.,RIKEN
Nature Physics | Year: 2011

Scientists have continually tried to improve the spatial resolution of imaging ever since the invention of the optical microscope in around 1610 by Galileo. Recently, a spatial resolution near /10 was achieved in a near-field scheme by using surface plasmon polaritons. However, further improvement in this direction is hindered by the size of metallic nanostructures. Here we show that atom-scale resolution is achievable in the extreme-ultraviolet region by using X-ray parametric down-conversion, which detaches the achievable resolution from the wavelength of the probe light. We visualize three-dimensionally the local optical response of diamond at wavelengths between 103 and 206Å with a resolution as fine as 0.54Å. This corresponds to a resolution from /190 to /380, an order of magnitude better than ever achieved. Although the present study focuses on the relatively high-energy optical regions, our method could be extended into the visible region using advanced X-ray sources, and would open a new window into the optical properties of solids. © 2011 Macmillan Publishers Limited. All rights reserved. Source

Iidaka T.,Nagoya University
Brain and Nerve | Year: 2012

Electrophysiological experiments in monkeys, and more recent functional magnetic resonance imaging (fMRI) studies in human subjects have shown that the superior temporal sulcus (STS) plays a role in face processing. The various roles of the STS in human cognition, including face processing, language, audio-visual integration, and motion perception, are expected to be subserved by the widespread neural connectivity of the STS with other brain regions, such as the primary sensory, limbic, and prefrontal areas. Among the multiple components involved in face processing, fMRI studies have shown that the STS is predominantly involved in the processing of gaze direction and emotional expression. Peak coordinates reported in previous fMRI studies were plotted on the Montreal Neurological Institute's standard brain template. A large cluster was located along the posterior to middle part of the STS, a role that is not selective for a particular task or for cognitive processing. The author focused on 3 aspects of the functional role of the STS: (i) the STS performs regionally specific functions; the posterior STS has low face-selectivity, and the anterior STS is relatively selective for face stimuli, (ii) the STS not only detects gaze direction and facial expression, but also detects intention, as indicated by the experimental stimuli, and (iii) the STS response increases when the intention and the subsequent results do not match. Based on these findings, the author speculates that the role of the STS in human cognition and emotion is to process "social attention," which is a crucial human skill for making inferences with respect to others' goals, intentions, and actions. Source

Ismail A.,Damanhour University | Takeda S.,Nagoya University | Nick P.,Karlsruhe Institute of Technology
Journal of Experimental Botany | Year: 2014

Salinity does not only stress plants but also challenges human life and the economy by posing severe constraints upon agriculture. To understand salt adaptation strategies of plants, it is central to extend agricultural production to salt-affected soils. Despite high impact and intensive research, it has been difficult to dissect the plant responses to salt stress and to define the decisive key factors for the outcome of salinity signalling. To connect the rapidly accumulating data from different systems, treatments, and organization levels (whole-plant, cellular, and molecular), and to identify the appropriate correlations among them, a clear conceptual framework is required. Similar to other stress responses, the molecular nature of the signals evoked after the onset of salt stress seems to be general, as with that observed in response to many other stimuli, and should not be considered to confer specificity per se. The focus of the current review is therefore on the temporal patterns of signals conveyed by molecules such as Ca2+, H+, reactive oxygen species, abscisic acid, and jasmonate. We propose that the outcome of the salinity response (adaptation versus cell death) depends on the timing with which these signals appear and disappear. In this context, the oftenneglected non-selective cation channels are relevant. We also propose that constraining a given signal is as important as its induction, as it is the temporal competence of signalling (signal on demand) that confers specificity. © The Author 2014. Source

Masunaga H.,Nagoya University | L'Ecuyer T.S.,Colorado State University
Journal of Climate | Year: 2010

The east Pacific double intertropical convergence zone (ITCZ) in austral fall is investigated with particular focus on the growing processes of its Southern Hemisphere branch. Satellite measurements from the Tropical Rainfall Measuring Mission (TRMM) and Quick Scatterometer (QuikSCAT) are analyzed to derive 8-yr climatology from 2000 to 2007. The earliest sign of the south ITCZ emerges in sea surface temperature (SST) by January, followed by the gradual development of surface convergence and water vapor. The shallow cumulus population starts growing to form the south ITCZ in February, a month earlier than vigorous deep convection is organized into the south ITCZ. The key factors that give rise to the initial SST enhancement or the southeast Pacific warm band are diagnosed by simple experiments. The experiments are designed to calculate SST, making use of an ocean mixed layer "model" forced by surface heat fluxes, all of which are derived from satellite observations. It is found that the shortwave flux absorbed into the ocean mixed layer is the primary driver of the southeast Pacific warm band. The warm band does not develop in boreal fall because the shortwave flux is seasonally so small that it is overwhelmed by other negative fluxes, including the latent heat and longwave fluxes. Clouds offset the net radiative flux by 10-15 W m-2, which is large enough for the warm band to develop in boreal fall if it were not for clouds reflecting shortwave radiation. Interannual variability of the double ITCZ is also discussed in brief. © 2010 American Meteorological Society. Source

Suzuki A.,Nagoya University
Brain and Nerve | Year: 2012

This paper reviews theories and research pertaining to emotional functions of the insula - a cortical area that is located deep in the lateral sulcus and has been included in the limbic lobe because of its intimate connections with the cingulate, amygdala, and orbitofrontal cortex. The insula is known to contain the primary gustatory cortex across mammalian species, and thus, earlier studies have focused on its special role in disgust, which is an emotion closely associated with the sensation of bad taste. In recent years, more emphasis has been placed on the insular contribution to conscious experience of emotion in general. Emotional experience has been known to depend on both the perception of bodily reactions to emotion-provoking objects and the cognitive appraisal of contexts. The insula is theoretically suited for representing such emotional experience because it receives interoceptive inputs from the whole body, and its connections with the prefrontal regions can provide contextual information. In fact, many studies have shown that the activation of the insula, particularly its anterior part, covaries with subjective feelings, which reflect not only physical stimulus intensity but also cognitive factors such as prediction. Such insular activation seems to work as a so-called "as if" somatic marker that inclines us to approach or avoid the stimulus; in addictive disorders, insular activation is proposed to be the neural basis for intense urges. In addition, the insula also represents "simulated" emotional experience, including empathy with others, which may play an important role in social learning. Thus, further investigations into the emotional functions of the insula would help elucidate the still unknown role of conscious experience in regulating cognitive processes and behavior. Source

Ishizaki T.,Japan National Institute of Advanced Industrial Science and Technology | Saito N.,EcoTopia Science Institute | Takai O.,Nagoya University
Langmuir | Year: 2010

A micropatterned superhydrophobic/superhydrophilic surface was successfully fabricated by plasma CVD and VUV irradiation. Physicochemical properties of the superhydrophobic, superhydrophilic, and superhydrophobic/superhydrophilic surfaces were investigated. The roughness structures on the superhydrophilic surface remained intact compared to those of the superhydrophobic surface. The micropatterned superhydrophobic/superhydrophilic surface was used as a scaffold of cell culture. On the micropatterned surface, the cells attached to the superhydrophilic regions in a highly selective manner, forming circular microarrays of the cells corresponding to the pattern. On the micropatterned surface with pattern distances of 200 μm between superhydrophilic regions, the cells adhered on the superhydrophilic regions and partly extended to the neighboring cells. In contrast, when the pattern distances between the superhydrophilic regions were more than 400 μm, the cells did not extend to the neighboring cells. Cell adhesion behaviors on superhydrophobic and superhydrophilic surfaces were also examined. The cells adhered and proliferated on both superhydrophobic and superhydrophilic surfaces. However, on the superhydrophobic surface, constant contact to facilitate cell division and proliferation was required. On the other hand, the cells easily adhered and proliferated on the superhydrophilic surface immediately after seeding. These differences in cell adhesion behavior induced site-selective cell adhesion on the superhydrophilic regions. Furthermore, protein adsorption behavior that plays an important role in cell adhesion on flat hydrophobic and hydrophilic surface was also examined. The amounts of the protein adsorption on the flat hydrophilic surface were much greater than those on the flat hydrophobic surface. © 2010 American Chemical Society. Source

Masunaga H.,Nagoya University
Journal of Climate | Year: 2012

In this study the observed relationship of precipitation with column relative humidity (CRH), a metric of tropospheric humidity, is examined in order to address a known discrepancy inherent to past studies. A composite analysis of satellite data is carried out to explore the short-term (i.e., from hourly to daily) atmospheric variability for comparison with the climatology, hypothesizing that a primary cause for the discrepancy arises from a difference in the time scale of interest. The analysis is broken down into four classes on the basis of the degree of convective organization, ranging from unorganized shallow cumuli to highly organized convective systems. The CRH-precipitation relationship is found to be extremely nonlinear for the shortterm variability, while the nonlinearity weakens to some degree when different convective systems in diverse humidity environments are averaged together into climatology. The weak exponential rise in the climatological CRH-precipitation curve occurs because highly organized convective systems become more frequent and intense and thus receive increasing weight in the climatological mean as the environment moistens. © 2012 American Meteorological Society. Source

Nishizawa N.,Nagoya University
Optical Fiber Technology | Year: 2012

Ultrawideband supercontinua have been generated using ultrashort pulses and zero-dispersion highly nonlinear fiber. However, they have inherent large noise and spectral fine structure. We generated a widely and flatly broadened, low-noise, highly coherent, high-quality supercontinuum and used it to demonstrate ultrahigh-resolution optical coherence tomography in several wavelength regions. © 2012 Elsevier Inc. All rights reserved. Source

Matsumoto S.,Osaka University | Fumoto K.,University Utrecht | Okamoto T.,Hiroshima University | Kaibuchi K.,Nagoya University | Kikuchi A.,Osaka University
EMBO Journal | Year: 2010

Wnt5a is a representative ligand that activates the Wnt/Β-catenin- independent pathway, resulting in the regulation of cell adhesion, migration, and polarity, but its molecular mechanism is poorly understood. This report shows that Dishevelled (Dvl) binds to adenomatous polyposis coli (APC) gene product, and this binding is enhanced by Wnt5a. Dvl was involved in the stabilization of the plus end dynamics of microtubules as well as APC. Frizzled2 (Fz2) was present with Wnt5a at the leading edge of migrating cells and formed a complex with APC through Dvl. Fz2 also interacted with integrins at the leading edge, and Dvl and APC associated with and activated focal adhesion kinase and paxillin. The binding of APC to Dvl enhanced the localization of paxillin to the leading edge and was involved in Wnt5a-dependent focal adhesion turnover. Furthermore, this new Wnt5a signalling pathway was important for the epithelial morphogenesis in the three-dimensional culture. These results suggest that the functional and physical interaction of Dvl and APC is involved in Wnt5a/Fz2-dependent focal adhesion dynamics during cell migration and epithelial morphogenesis. © 2010 European Molecular Biology Organization | All Rights Reserved. Source

Matthew S.C.,Queens University | Glasspoole B.W.,Queens University | Eisenberger P.,Queens University | Crudden C.M.,Queens University | Crudden C.M.,Nagoya University
Journal of the American Chemical Society | Year: 2014

The Suzuki-Miyaura cross-coupling of chiral, enantiomerically enriched dibenzylic boronic esters is described. The reaction proceeds with almost complete retention of stereochemistry, providing access to triarylmethanes, compounds that have high biological activity and are difficult to prepare in enantiomerically pure form using other methods. © 2014 American Chemical Society. Source

For efficient photoresponses of liquid-crystal (LC) azobenzene (Az) polymer systems, planar LC orientation of the Az mesogenic group is required because the light irradiation process usually occurs with normal incidence to the film surface. However, LC molecules with a rodlike shape tend to orient perpendicularly to the film surface according to the excluded volume effect theory. This review introduces new approaches for inducing planar orientation in side-chain LC Az polymer films via interface and surface molecular designs. The planar orientation offers efficient in-plane photoalignment and photoswitching to hierarchical LC architectures from molecular LC mesogens and LC phases to mesoscopic microphase-separated structures. These approaches are expected to provide new concepts and possibilities in new LC polymer devices. © 2016 The Author. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Indoxyl sulfate, a nephrovascular uremic toxin, is markedly accumulated in the serum of chronic kidney disease (CKD) patients. Because of its protein binding ability, its removal by hemodialysis is not as efficient as that of non-protein bound uremic toxins. AST-120 delays the progression of CKD by adsorbing indole, a precursor of indoxyl sulfate, in the intestines, and consequently reduces the serum levels of indoxyl sulfate. Indoxyl sulfate exhibits cellular toxicity in renal tubular cells, glomerular mesangial cells, vascular smooth muscle cells, vascular endothelial cells, cardiac myocytes, and osteoblasts by inducing oxidative stress. Indoxyl sulfate stimulates the progression of CKD by increasing the expression of fibrogenic genes such as transforming growth factor-β1 in CKD rats. Indoxyl sulfate stimulates aortic calcification in hypertensive rats; thus, indoxyl sulfate is involved in the progression of CKD and cardiovascular disease. Experimental and clinical data demonstrate that AST-120 delays the progression not only of chronic kidney disease, but also of cardiovascular disease. © 2011 The Author. Therapeutic Apheresis and Dialysis © 2011 International Society for Apheresis. Source

Nishikawa T.,Nagoya University | Isobe M.,National Tsing Hua University
Chemical Record | Year: 2013

Tetrodotoxin, a toxic principle of puffer fish intoxication, is one of the most famous marine natural products due to its densely functionalized structure and potent toxicity. Despite its small molecular size (MW 319 g mol -1), tetrodotoxin has long been well known as a formidable molecule in natural product synthesis. We have devoted more than twenty years to developing synthetic strategies for this molecule, resulting in the preparation of a variety of analogues of tetrodotoxin for biological experiments. This account describes a brief history of tetrodotoxin research and an overview of our synthetic efforts toward tetrodotoxin with the underlying logic and strategy. Tetrodotoxin, a toxic principle of puffer fish intoxication, is one of the most well-known marine natural products due to its unique structure and potent toxicity. Despite its small molecular size (MW 319 g mol-1), tetrodotoxin has long been well known as a formidable molecule in natural product synthesis. We have devoted more than twenty years to developing synthetic strategies for this molecule, resulting in the preparation of a variety of analogues of tetrodotoxin for biological experiments. This account provides a brief history of tetrodotoxin research, and an overview of our synthetic efforts toward tetrodotoxin with the underlying logic and strategy. Copyright © 2013 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Naito T.,Kushiro Public University of Economics | Ogawa H.,Nagoya University
Environmental Economics and Policy Studies | Year: 2014

This article examines the optimal environmental regulation in a mixed duopolistic market wherein environmental damage is associated with production. Specifically, the effects of partial privatization on optimal policy choices, environmental damage, and social welfare are examined under three regimes: no regulation, direct regulation on emission, and the indirect regulation via Pigouvian tax. The common result under the different regimes of regulation is that the optimal level of environmental regulation critically depends on the degree of privatization, and its relationship is not monotonous. Furthermore, results show that while privatization results in different impacts on policy choices, environmental damage, and social welfare under the three different regimes, it is mostly compatible with an improvement in environmental quality. © 2009, Springer Japan. Source

Takekawa M.,Nagoya University
Nagoya journal of medical science | Year: 2011

Mammalian cells are frequently exposed to a variety of environmental stresses, such as ultraviolet rays, ionizing radiation, genotoxins, heat shock, and oxidative stress. In coping with the barrage of these and other stresses, multi-cellular eukaryotic organisms have developed a strategy as to how damaged cells will respond to stresses. In general, if the intensity of the damage is moderate, the cell will seek to repair the damage. If, however, the damage to a cell is too severe to be repaired, the affected cells are eliminated by apoptosis. This cell death reduces the risk to the organism as a whole, such as development of a cancer. Such a crucial decision between survival and death is, at least in part, mediated by the stress-activated MAP kinase (SAPK) pathways. SAPKs are a group of serine/threonine protein kinases that convert extracellular stress stimuli into diverse cellular responses, including cell cycle arrest, apoptotic cell death, and cytokine production, through phosphorylation of specific target proteins. Recent progress in the identification of molecules that participate in the SAPK pathways, such as GADD45 proteins and Wipl, has provided new insights, not only into the molecular basis of the cellular response to environmental stress, but also into the etiology of human diseases including cancer. Source

Myneni V.D.,McGill University | Hitomi K.,Nagoya University | Kaartinen M.T.,McGill University
Blood | Year: 2014

Factor XIII-A (FXIII-A) transglutaminase (TG) was recently identified as a potential causative obesity gene in human white adipose tissue (WAT). Here, we have examined the role of TG activity and the role of protein crosslinking in adipogenesis. Mouse WAT and preadipocytes showed abundant TG activity arising from FXIII-A. FXIII-A was localized to the cell surface and acted as a negative regulator of adipogenesis by promoting assembly of fibronectin (FN) from plasma into preadipocyte extracellular matrix. This modulated cytoskeletal dynamics and maintained the preadipocyte state. FXIII-A-assembled plasma FN (pFN) matrix promoted preadipocyte proliferation and potentiated the proproliferative effects of insulin (INS) while suppressing the prodifferentiating INS signaling. FXIII-A-deficient mouse embryonic fibroblasts showed increased lipid accumulation and decreased proliferation as well as decreased pFN assembly into extracellular matrix. Thus, FXIII-A serves as a preadipocyte-bound proliferation/differentiation switch that mediates effects of hepatocyte-produced circulating pFN. © 2014 by The American Society of Hematology. Source

Spirocyclic scaffolds are embedded in many biologically active natural compounds, including candidates for medicines, perfumes and agricultural chemicals. Therefore, the development of efficient synthetic methods directed at those structures is strongly in demand. To this end, we have recently developed synthetic methodologies for two different spirocyclic frameworks, spiro[4.5]decanes and spirocyclic oxindoles, based on the Claisen rearrangement. We have developed the Claisen rearrangement protocol by which bicyclic 2-(alkenyl)dihydropyrans with functionality at the 4-position can be transformed into spiro[4.5]decanes in good-to-excellent yields with excellent stereoselectivities. We applied this method to a concise total synthesis of several biologically active spirocyclic sesquiterpenes. Related Claisen rearrangement in alkenyl pyranoindole systems can also be achieved. Thus, a one-pot intramolecular Ullmann coupling (IUC)/Claisen rearrangement sequence from 2-iodoindoles was found to provide spirocyclic oxindoles in good yields with excellent stereoselectivities. We applied this sequence to the synthesis of pyrrolidinoindoline alkaloids. © Georg Thieme Verlag Stuttgart · New York. Source

Takeuchi T.T.,Nagoya University
Monthly Notices of the Royal Astronomical Society | Year: 2010

We provide an analytic method to construct a bivariate distribution function (DF) with given marginal distributions and correlation coefficient. We introduce a convenient mathematical tool, called a copula, to connect two DFs with any prescribed dependence structure. If the correlation of two variables is weak (Pearson's correlation coefficient |ρ| < 1/3), the Farlie-Gumbel-Morgenstern (FGM) copula provides an intuitive and natural way to construct such a bivariate DF. When the linear correlation is stronger, the FGM copula cannot work anymore. In this case, we propose using a Gaussian copula, which connects two given marginals and is directly related to the linear correlation coefficient between two variables. Using the copulas, we construct the bivariate luminosity function (BLF) and discuss its statistical properties. We focus especially on the far-infrared-far-ulatraviolet (FUV-FIR) BLF, since these two wavelength regions are related to star-formation (SF) activity. Though both the FUV and FIR are related to SF activity, the univariate LFs have a very different functional form: the former is well described by the Schechter function whilst the latter has a much more extended power-law-like luminous end. We construct the FUV-FIR BLFs using the FGM and Gaussian copulas with different strengths of correlation, and examine their statistical properties. We then discuss some further possible applications of the BLF: the problem of a multiband flux-limited sample selection, the construction of the star-formation rate (SFR) function, and the construction of the stellar mass of galaxies (M *)-specific SFR (SFR/M *) relation. The copulas turn out to be a very useful tool to investigate all these issues, especially for including complicated selection effects. © 2010 The Author. Journal compilation © 2010 RAS. Source

Sato M.,Nagoya University | Nishimichi T.,University of Tokyo
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We study how well the Gaussian approximation is valid for computing the covariance matrices of the convergence power and bispectrum in weak gravitational lensing analyses. We focus on its impact on the cosmological parameter estimations by comparing the results with and without non-Gaussian error contribution in the covariance matrix. We numerically derive the covariance matrix as well as the cosmology dependence of the spectra from a large set of N-body simulations performed for various cosmologies and carry out Fisher matrix forecasts for tomographic weak lensing surveys with three source redshifts. After showing the consistency of the power and bispectra measured from our simulations with the state-of-the-art fitting formulas, we investigate the covariance matrix assuming a typical ongoing survey across 1500 deg2 with the mean source number density of 30 arcmin-2 at the mean redshift zs=1.0. Although the shape noise contributes a significant fraction to the total error budget and it mitigates the impact of the non-Gaussian error for this source number density, we find that the non-Gaussian error degrades the cumulative signal-to-noise ratio up to the maximum multipole of 2000 by a factor of about 2 (3) in the power (bi-) spectrum analysis. Its impact on the final cosmological parameter forecast with 6 parameters can be as large as 15% in the size of the one-dimensional statistical error. This can be a problem in future wide and deep weak lensing surveys for precision cosmology. We also show how much the dark energy figure of merit is affected by the non-Gaussian error contribution and demonstrate an optimal survey design with a fixed observational time. © 2013 American Physical Society. Source

Matsuoka K.,Nagoya University
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2014

A square shape multi-anode micro-channel-plate photomultiplier tube (MCP-PMT) was developed for the Belle II TOP counter. It has a 23×23 mm2 multi-alkali photocathode with a peak quantum efficiency (QE) of 28% around a wavelength of 360 nm. It has a 2×106 gain and is capable of detecting a single photon with a transit time spread (TTS) of 40 ps or less. The QE, gain and TTS were measured for each MCP-PMT to check the quality in the mass production of 550 MCP-PMTs. The lifetime of the MCP-PMT was extended to 10 C/cm2 by adapting the atomic layer deposition technique for the MCP coating. Other properties of the MCP-PMT are also discussed: the angle and polarization dependence of the QE, and the effects of charge sharing and cross-talk. A prototype TOP counter was tested with a 2 GeV/c positron beam. The distribution of the time of propagation was consistent with the calculated expectation which included those properties of the MCP-PMT. © 2014 Elsevier B.V. Source

Hirose S.,Nagoya University
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2014

The time of propagation (TOP) counter is a novel particle identification device for the Belle II experiment, utilizing the ring imaging Cherenkov technique. It is composed of a 2.7 m long quartz bar and 32 micro channel plate photomultiplier tubes (MCP-PMTs) attached on the end of the bar. The MCP-PMT has a typical quantum efficiency of 28%, a photoelectron collection efficiency of about 55%, and a transit time spread (TTS) less than 50 ps for single photon detection. Since the TOP counters are installed in the 1.5 T magnetic field of the Belle II detector, the MCP-PMTs are required to keep those characteristics with gain of more than 5×105 in the magnetic field. Therefore, we investigated gain, TTS, and single photon detection efficiency of the MCP-PMTs in the magnetic field and found that they satisfy the requirements. We are starting complete inspections for more than 500 MCP-PMTs, and have inspected up to 87 MCP-PMTs. © 2014 Elsevier B.V. All rights reserved. Source

We show that complete positivity is not only sufficient but also necessary for the validity of the quantum data-processing inequality. As a consequence, the reduced dynamics of a quantum system are completely positive, even in the presence of initial correlations with its surrounding environment, if and only if such correlations do not allow any anomalous backward flow of information from the environment to the system. Our approach provides an intuitive information-theoretic framework to unify and extend a number of previous results. © 2014 American Physical Society. Source

Beye F.,Nagoya University | Kobayashi T.,Hokkaido University | Kuwakino S.,Chung Yuan Christian University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We show that non-Abelian discrete symmetries in orbifold string models have a gauge origin. This can be understood when looking at the vicinity of a symmetry enhanced point in moduli space. At such an enhanced point, orbifold fixed points are characterized by an enhanced gauge symmetry. This gauge symmetry can be broken to a discrete subgroup by a nontrivial vacuum expectation value of the Kähler modulus T. Using this mechanism it is shown that the δ(54) non-Abelian discrete symmetry group originates from a SU(3) gauge symmetry, whereas the D4 symmetry group is obtained from a SU(2) gauge symmetry. © 2014 The Authors. Source

Kobayashi H.,Nagoya University | Dauphas N.,University of Chicago
Icarus | Year: 2013

Mars is likely to be a planetary embryo formed through collisions with planetesimals, which can explain its small mass and rapid formation timescale obtained from 182Hf-182W chronometry. In the classical theory of planet formation, the final embryo mass is determined only by the solid surface density. However, embryos can stir surrounding planetesimals, leading to fragmentation through erosive (cratering) collisions. We find that radial drift of small fragments can drastically reduce the solid surface density. On the other hand, embryo growth is accelerated by fragment accretion. Since collisional fragmentation efficiency depends on the initial size of planetesimals, the final embryo mass and its growth time are determined by the initial planetesimal size and disk surface density. We have investigated the effect of these two parameters on the mass of Mars and the predicted radiogenic excess of 182W in the martian mantle. Two scenarios can explain the rapid formation of small Mars: (i) it formed by accretion of small planetesimals in a massive disk or (ii) it formed from large planetesimals but its growth was arrested by the inward then outward migration of Jupiter. Taking into account all constraints, we conclude that Mars is likely to have formed in a massive disk of about ~0.1 solar mass from planetesimals smaller than ~10km in radius. Such small planetesimal size cannot explain core accretion of Jupiter, suggesting that there may have been a heliocentric gradient in planetesimal size in the solar nebula. © 2013 Elsevier Inc. Source

Baktygul K.,Nagoya University
Nagoya journal of medical science | Year: 2011

This study was undertaken to evaluate the pattern of antibiotic prescriptions in a secondary health care setting in Kyrgyzstan. A retrospective analysis was performed of antibiotic prescriptions in 251 inpatient records of patients admitted to the Sokuluk Territorial Hospital. A total of 19 different antibiotics were prescribed. Penicillin G (24.9%), gentamicin (16.1%), metronidazole (15.6%) and cefazolin (14.5%) were those most frequently prescribed. The major indications for antibiotics were diseases of the respiratory system (28.0%), injury, poisoning and certain other consequences from external causes (25.5%), and diseases of the digestive system (14.3%). Almost three-quarters of the antibiotics were used parenterally, 252 of which (58.9%) were administered intramuscularly and 70 (16.4%) intravenously. Forty-five percent of the patients received two antibiotics, and 12.0% received three antibiotics during their stay at the hospital. Antibiotic therapy proved inappropriate for 184 patients (73.3%). The most common reason given for inappropriateness was the unjustified (not indicated) use of antibiotics in 143 (48.6%) cases. There was a significantly higher inappropriate choice of antibiotics in gynecology (OR = 2.70, 95% CI = 1.02-7.69) when compared with that in other wards. Although antibiotics were prescribed in all cases post-operatively, none of those patients were given pre-operative prophylactic antibiotics when indicated. We concluded that antibiotic prescriptions were seriously inappropriate in the Kyrgyz Republic with prescribing patterns failing to strictly adhere to the national guidelines. Adoption of an international standard and locally conformable guidelines of antibiotic use can help correct such problems. Source

Yamawaki K.,Nagoya University
International Journal of Modern Physics A | Year: 2010

In contrast to the folklore that Technicolor (TC) is a "Higgsless theory", we shall discuss existence of a composite Higgs boson, Techni-Dilaton (TD), a pseudo-Nambu-Goldstone boson of the scale invariance in the Scale-invariant/Walking/Conformal TC (SWC TC) which generates a large anomalous dimension γm ≃ 1 in a wide region from the dynamical mass m = O (TeV) of the techni-fermion all the way up to the intrinsic scale ΛTC of the SWC TC (analogue of ΛQCD), where ΛTC is taken typically as the scale of the Extended TC scale ΛETC: ΛTC ≃ Λ ETC ∼ 103 TeV (≫ m). All the techni-hadrons have mass on the same order O(m) which in SWC TC is extremely smaller than the intrinsic scale ΛTC ≃ ΛETC, in sharp contrast to QCD where both are of the same order. The mass of TD arises from the non-perturbative scale anomaly associated with the techni-fermion mass generation and is typically 500-600 GeV, even smaller than other techni-hadrons of the same order of O (m), in another contrast to QCD which is believed to have no scalar q̄q bound state lighter than other hadrons. We discuss the TD mass in various methods, Gauged NJL model via ladder Schwinger-Dyson (SD) equation, straightforward calculations in the ladder SD/ Bethe-Salpeter equation, and the holographic approach including techni-gluon condensate. The TD may be discovered in LHC. © 2010 World Scientific Publishing Company. Source

Nishimoto S.,Nagoya City Science Museum | Yoshida H.,Nagoya University
Lithos | Year: 2010

This paper investigates the mineralogical effects of hydrothermal alteration at depth in fractures in granite. A fracture accompanied by an alteration halo and filled with clay was found at a depth of 200 m in a drill core through Toki granite, Gifu, central Japan. Microscopic observation, XRD, XRF, EPMA and SXAM investigations revealed that the microcrystalline clays consist of illite, quartz and pyrite and that the halo round the fracture can be subdivided into a phyllic zone adjacent to the fracture, surrounded by a propylitic zone in which Fe-phyllosilicates are present, and a distinctive outer alteration front characterized by plagioclase breakdown. The processes that result in these changes took place in three successive stages: 1) partial dissolution of plagioclase with partial chloritization of biotite; 2) biotite dissolution and precipitation of Fe-phyllosilicate in the dissolution pores; 3) dissolution of K-feldspar and Fe-phyllosilicate, and illite precipitation associated with development of microcracks. These hydrothermal alterations of the granite proceed mainly by a dissolution-precipitation process resulting from the infiltration of hydrothermal fluid along microcracks. Such infiltration causes locally high mobility of Al and increases the ratio of fluid to rock in the alteration halo. These results contribute to an understanding of how granitic rock becomes altered in orogenic fields such as the Japanese island arc. © 2009 Elsevier B.V. All rights reserved. Source

Kaneda F.,Tohoku University | Baek S.-Y.,Tohoku University | Ozawa M.,Nagoya University | Edamatsu K.,Tohoku University
Physical Review Letters | Year: 2014

We experimentally test the error-disturbance uncertainty relation (EDR) in generalized, strength-variable measurement of a single photon polarization qubit, making use of weak measurement that keeps the initial signal state practically unchanged. We demonstrate that the Heisenberg EDR is violated, yet the Ozawa and Branciard EDRs are valid throughout the range of our measurement strength. © 2014 American Physical Society. Source

Umeda T.,Nagoya University
Journal of Geophysical Research: Space Physics | Year: 2010

Two-dimensional electromagnetic particle-in-cell simulations are performed for examination of electromagnetic plasma emission at twice the electron plasma frequency. Electromagnetic "2fp" waves are considered to be excited by nonlinear three-wave processes in beam-plasma interactions. In this paper, nonlinear development of an electron-beam-plasma instability is studied as an initial value problem. The present simulation result confirmed that electromagnetic 2fp waves are strongly enhanced by the wave-wave interaction between forward and backward Langmuir waves, which is in agreement with the previous studies. It is also demonstrated that large-amplitude forward Langmuir waves decay into backward Langmuir waves and ion acoustic waves via a parametric decay and that electromagnetic 2fp waves are also enhanced by the decay of Langmuir waves. However, the growth rate of the electromagnetic 2fp waves due to the parametric decay of Langmuir waves is not as high. It should be noted that induced backscattering of Langmuir waves by enhanced thermal fluctuations of ions cannot be neglected in the excitation of backward Langmuir waves. Hence, low-noise simulations are necessary to suppress the effect of enhanced thermal fluctuations in the particle-in-cell method. Copyright 2010 by the American Geophysical Union. Source

Kuroki T.,Nagoya University | Sugino F.,Okayama Institute for Quantum Physics
Journal of High Energy Physics | Year: 2014

In the previous paper, the authors pointed out correspondence of a supersymmetric double-well matrix model with two-dimensional type IIA superstring theory on a nontrivial Ramond-Ramond background from the viewpoint of symmetries and spectrum. In this paper we further investigate the correspondence from dynamical aspects by comparing scattering amplitudes in the matrix model and those in the type IIA theory. In the latter, cocycle factors are introduced to vertex operators in order to reproduce correct transformation laws and target-space statistics. By a perturbative treatment of the Ramond-Ramond background as insertions of the corresponding vertex operators, various IIA amplitudes are explicitly computed including quantitatively precise numerical factors. We show that several kinds of amplitudes in both sides indeed have exactly the same dependence on parameters of the theory. Moreover, we have a number of relations among coefficients which connect quantities in the type IIA theory and those in the matrix model. Consistency of the relations convinces us of the validity of the correspondence. © 2014 The Author(s). Source

Shinoda W.,Nagoya University
Biochimica et Biophysica Acta - Biomembranes | Year: 2016

Molecular permeation through lipid membranes is a fundamental biological process that is important for small neutral molecules and drug molecules. Precise characterization of free energy surface and diffusion coefficients along the permeation pathway is required in order to predict molecular permeability and elucidate the molecular mechanisms of permeation. Several recent technical developments, including improved molecular models and efficient sampling schemes, are illustrated in this review. For larger penetrants, explicit consideration of multiple collective variables, including orientational, conformational degrees of freedom, are required to be considered in addition to the distance from the membrane center along the membrane normal. Although computationally demanding, this method can provide significant insights into the molecular mechanisms of permeation for molecules of medical and pharmaceutical importance. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg. © 2016 Elsevier B.V. Source

A genome-wide association study (GWAS) can be a powerful tool for the identification of genes associated with agronomic traits in crop species, but it is often hindered by population structure and the large extent of linkage disequilibrium. In this study, we identified agronomically important genes in rice using GWAS based on whole-genome sequencing, followed by the screening of candidate genes based on the estimated effect of nucleotide polymorphisms. Using this approach, we identified four new genes associated with agronomic traits. Some genes were undetectable by standard SNP analysis, but we detected them using gene-based association analysis. This study provides fundamental insights relevant to the rapid identification of genes associated with agronomic traits using GWAS and will accelerate future efforts aimed at crop improvement. © 2016 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. Source

Awata H.,Nagoya University | Yamada Y.,Kobe University
Progress of Theoretical Physics | Year: 2010

We discuss an analog of the AGT relation in five dimensions. We define a q-deformation of the β-ensemble which satisfies q-W N constraint. We also show a relation with the Nekrasov partition function of 5D SU(N) gauge theory with N f = 2N. Source

Kaneyoshi T.,510 Kurosawadai | Kaneyoshi T.,Nagoya University
Journal of Magnetism and Magnetic Materials | Year: 2010

Magnetizations of a cylindrical nanowire described by the transverse Ising model are investigated by the use of the effective field theory with correlations (EFT), since the phase diagrams of the system have been examined in the previous work (J. Magn. Magn. Mater. (2010), in press) by using the two theoretical frameworks of the mean field theory and the EFT. The temperature dependences of longitudinal and transverse magnetizations in the system are strongly affected by the surface situations. Many characteristic phenomena are found in the thermal variations, depending on the ratio of the physical parameters in the surface shell and the core. In particular, the effects of the two transverse fields at the surface shell and in the core to these magnetizations have been firstly clarified. © 2010 Elsevier B.V. All rights reserved. Source

Kaneyoshi T.,1 510 Kurosawadai | Kaneyoshi T.,Nagoya University
Journal of Magnetism and Magnetic Materials | Year: 2010

Phase diagrams of a cylindrical nanowire described by the transverse Ising model are investigated by the use of two theoretical frameworks, namely the mean field theory and the effective field theory with correlations. The phase diagram of the system is strongly affected by the surface situations. Some characteristic phenomena are found in the phase diagram, depending on the ratio of the physical parameters in the surface shell and the core. © 2010 Elsevier B.V. Source

Yoshioka S.,Osaka University | Takeoka Y.,Nagoya University
ChemPhysChem | Year: 2014

It is desirable to produce colourful pigments that have anti-fading properties and are environmentally friendly. In this Concept, we describe recently developed pigments that exhibit such characteristics. The pigments consist of amorphous arrays of submicron silica particles, and they exhibit saturated and angle-independent structural colours. Variously coloured pigments can be produced by changing the size of the particles, and the saturation of the colour can be controlled by incorporating small amounts of black particles. We review a simple analysis that is useful for interpreting the angular independence of the structural colours and discuss the remaining tasks that must be accomplished for the realistic application of these pigments. In full color: This Concept describes recently developed structurally colored pigments that have antifading properties and are environmentally friendly. The pigments consist of amorphous arrays of submicron silica particles (see picture). The colour saturation is controlled by incorporating small amounts of carbon black. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

The technical simplicity of retrograde cerebral perfusion (RCP) together with a highly favorable effect upon stroke rates and survival after aortic arch surgery justifies continued clinical use of RCP in patients requiring hypothermic circulatory arrest (HCA), in particular patients with dissecting or atheromatous arch branches. In clinical practice, using RCP can provide effective brain protection in HCA for about 40 to 60 minutes, although there is a time limitation. © 2010 Elsevier Inc. Source

Kumagai T.,Nagoya University | Kumagai T.,Duke University | Porporato A.,Duke University
Plant, Cell and Environment | Year: 2012

Although Bornean tropical rainforests are among the moistest biomes in the world, they sporadically experience periods of water stress. The observations indicate that these ecosystems tend to have little regulation of water use, despite episodes of relatively severe drought. This water-use behaviour is often referred to as anisohydric behaviour, as opposed to isohydric plants that regulate stomatal movement to prevent hydraulic failure. Although it is generally thought that anisohydric behaviour is an adaptation to more drought-prone habitats, we show that anisohydric plants may also be more favoured than isohydric plants under very moist environments where there is little risk of hydraulic failure. To explore this subject, we examined the advantages of isohydric and anisohydric species as a function of the hydroclimatic environment using a stochastic model of soil moisture and carbon assimilation dynamics parameterized by field observations. The results showed that under very moist conditions, anisohydric species tend to have higher productivity than isohydric plants, despite the fact that the two plant types show almost the same drought-induced mortality. As precipitation decreases, the mortality of anisohydric plants drastically increases whereas that of isohydric plants remains relatively constant and low; in these conditions, isohydric plants surpass anisohydric plants in their productivity. The observations indicate that a Bornean tropical rainforest ecosystem tends to have little regulation of water use referred to as anisohydric behavior, as opposed to isohydric plants that have a wide range of stomatal regulation to prevent hydraulic failure. Although it is generally thought that such an anisohydric behavior is an adaptation to more drought-prone habitats, we show that anisohydric plants may also be more favored than isohydric plants under very moist environments, e.g., a tropical rainforest. In this study, we examined the advantages of isohydric and anisohydric species as a function of the hydroclimatic environment using stochastic model of soil moisture and carbon assimilation dynamics parameterized by field observations. © 2011 Blackwell Publishing Ltd. Source

Matsubayashi Y.,Nagoya University
Plant and Cell Physiology | Year: 2011

More than a dozen secreted peptides are now recognized as important hormones that coordinate and specify cellular functions in plants. Recent evidence has shown that secreted peptide hormones often undergo post-translational modification and proteolytic processing, which are critical for their function. Such 'small post-translationally modified peptide hormones' constitute one of the largest groups of peptide hormones in plants. This short review highlights recent progress in research on post-translationally modified peptide hormones, with particular emphasis on their structural characteristics and modification mechanisms. © 2010 The Author. Source

Kanamaru K.,Nagoya University
Bioscience, Biotechnology and Biochemistry | Year: 2011

The His-Asp phosphorelay signal transduction system has been identified in most organisms, including bacteria, yeasts, fungi, and plants, except for animals. This system is important in adaptation to stress, control of cell growth, and induction of development in response to environmental changes. On the basis of genomic information, it has been found that Aspergillus nidulans, a model species of fungi, includes 15 histidine kinases (HKs), one histidine-containing phosphotransmitter protein (HPt), and four reponse regulators (RRs) as factors related to the signal transduction system. In this review, it is explain that the His-Asp phosphorelay system is important in controling cell growth (responses to fungicides, the induction of asexual and sexual development, and so on) under different growth conditions with reference to A. nidulans. Source

Two distinct types of colloidal particle aggregated states exist in opal, namely, the colloidal crystal and the colloidal amorphous array. Today, these aggregates can be artificially prepared and are now studied as non-fading structurally colored materials as a result of our better understanding of their optical properties. Additionally, by applying the aggregates as stimuli-responsive materials, we can fabricate stimuli-responsive structurally colored systems that change their hue and saturation in response to external stimuli. In this review, the conditions necessary for fabricating stimuli-responsive structurally colored systems using the two types of aggregates present in opal are explained. This journal is © 2013 The Royal Society of Chemistry. Source

Niwa T.,Nagoya University
Mass Spectrometry Reviews | Year: 2011

Mass spectrometry (MS) has been successfully applied for the identification and quantification of uremic toxins and uremia-associated modified proteins. This review focuses on the recent progress in the MS analysis of uremic toxins. Uremic toxins include low-molecular weight solutes, protein-bound low-molecular weight solutes, and middle molecules (peptides and proteins). Based on MS analysis of these uremic toxins, the pathogenesis of the uremic symptoms will be elucidated to prevent and manage the symptoms. Notably, protein-bound uremic toxins such as indoxyl sulfate, p-cresyl sulfate, and 3-carboxy-4-methyl-5- propyl-2-furanpropionic acid have emerged as important targets of therapeutic removal. Hemodialysis even with a high-flux membrane cannot efficiently remove the protein-bound uremic toxins because of their high albumin-binding property. The accumulation of these protein-bound uremic toxins in the blood of dialysis patients might play an important role in the development of uremic complications such as cardiovascular disease. Indoxyl sulfate is the most promising protein-bound uremic toxin as a biomarker of progress in chronic kidney disease. Novel dialysis techniques or membranes should be developed to efficiently remove these protein-bound uremic toxins for the prevention and management of uremic complications. © 2011 Wiley Periodicals, Inc. Source

Yamamoto A.,Nagoya University
Nuclear Science and Engineering | Year: 2012

An approach incorporating the discontinuity factor in transport calculations based on the integrodifferential transport equation, e.g., the discrete ordinates method, the method of characteristics, and the Monte Carlo method, is proposed. In the present approach, the effect of the discontinuity factor is incorporated by correcting cross sections (absorption, production, and scattering cross sections are divided by the discontinuity factor), and the anisotropic scattering cross sections of odd order are corrected with the discontinuity factor and the total cross section. The validity of the present method is confirmed through simple benchmark calculations using the method of characteristics. The present method would be a candidate for a mitigation method for errors associated with approximations, e.g., energy condensation, spatial homogenization, or coarse discretization, in transport calculations. Source

Tabata T.,Kobe University | Okuda T.,Nagoya University
Energy | Year: 2012

This paper discusses the effectiveness of a woody biomass utilization system that would result in increased net energy production through wood pellet production, along with energy recovery processes as they relate to household energy demand. The direct environmental load of the system, including wood pellet production and utilization processes, was evaluated. Furthermore, the indirect load, including the economic impact of converting the existing fossil-fuel-based energy system into a woody biomass-based system, on the entire society was also evaluated. Gifu Prefecture in Japan was selected for a case study, which included a comparative evaluation of the environmental load and costs both with and without coordination with the wood pellet production process and the waste-to-energy of municipal solid waste process, using the life cycle assessment methodology. If the release of greenhouse gases from the combustion of wood pellets is included in calculations, then burning wood pellets results in unfavorable environmental consequences. However, when the reduced indirect environmental load due to the utilization of wood pellets versus petroleum is included in calculations, then favorable environmental consequences result, with a net reduction of greenhouse gases emissions by 14,060 ton-CO 2eq. © 2012 Elsevier Ltd. Source

The Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study) is a long-term cohort study to investigate the interactions among genotypes, lifestyles, and lifestyle-related diseases, especially cancer. This article reports the outline of the baseline survey of the Daiko Study, one site of the J-MICC Study. That survey was conducted between June 9, 2008 and May 31, 2010 at the Daiko Medical Center of Nagoya University in Nagoya, Japan. Subjects were registered residents of Nagoya City aged 35 to 69 years who had not participated in other J-MICC sites. Recruitment was mainly announced through leaflets distributed in mailboxes citywide, personal communications, and regional information, such as posters in public or commercial facilities. Participants provided blood plasma, serum, buffy coat, urine, and data on health check-ups. They also completed a self-reported questionnaire on lifestyle, disease history, family history, and for women, reproductive history. As of the end of September 2010, 4 out of 5172 registered participants had withdrawn from the study, leaving data from 5168 participants (1467 males and 3701 females) available for analysis. Mean age +/- standard deviation (SD) was 52.5 +/- 10.3 years. Current smokers accounted for 24.1% (n=354) of males and 6.9% (n=256) of females. Current drinkers included 74.9% (n=1099) of males and 45.9% (n=1699) of females. Lifestyle data and specimens were successfully collected to examine any associations among disease biomarkers, lifestyles, and genotypes. Source

The angiotensin I-converting enzyme (ACE) is involved in cell proliferation, angiogenesis, inflammation, and tissue remodeling, all of which could play a role in carcinogenesis. The DD genotype of ACE I/D polymorphism with a higher ACE level than either ID or II genotypes was reported to increase the risk of several cancers. This is a case-control study examining the association between the polymorphism and gastric cancer risks among Japanese. Cases numbered 583 patients aged 27 to 80 years with gastric cancer diagnosed at the Aichi Cancer Center Hospital from 2001 to 2005. Controls were 1,742 sex and age frequency-matched cancer-free patients, who visited the same hospital during that same period. The ACE I/D polymorphism was genotyped using a polymerase chain reaction with confronting two-pair primers. The results showed that the age- and sex- adjusted ORs of gastric cancer were 0.95 (95% CI, 0.78-1.16) for ID, and 1.08 (95% CI, 0.80-1.46) for DD relative to II. Among the controls with H. pylori sero-positive or gastric atrophy (GA), the ORs of ID and DD relative to II were 1.20 (95% CI, 0.88-1.63) and 1.16 (95% CI, 0.73-1.84) for mild GA, and 1.22 (95% CI, 0.84-1.78) and 1.08 (95% CI, 0.61-1.89) for severe GA, respectively. In conclusion, there was no significant association of the ACE I/D polymorphism with the risk of gastric cancer. Among the controls, the polymorphism was not associated with the severity of GA. Source

Akiyama S.,Nagoya University
Cellular and Molecular Life Sciences | Year: 2012

KaiC is a core protein of the cyanobacterial Kai oscillator, which persists without transcription-translation feedback. In the presence of KaiA and KaiB, KaiC reveals rhythmic activation/inactivation of its ATPase and autokinase/autophosphotase activities over approximately 24 h. Since the in vitro reconstruction of the Kai oscillator, the structures and functions of the Kai proteins have been studied extensively. Each protein's crystal structure and low-resolution views of Kai complexes have been reported. In addition, newer data are emerging on dynamic aspects such as assembly/disassembly of the Kai components and a ticking motion of KaiC, which is probably coupled to its slow, temperature-compensated ATPase activity. The accumulated evidence offers an ideal opportunity to revisit a fundamental question regarding biological circadian clocks: what determines the temperature-compensated 24 h period? In this review, I summarize the current understanding of the Kai oscillator's molecular mechanism and discuss emerging ideas on protein clocks. © 2012 Springer Basel AG. Source

Akamatsu Y.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

On the basis of the closed-time-path formalism of nonequilibrium quantum field theory, we derive the real-time quantum dynamics of heavy-quark systems. Even though our primary goal is the description of heavy quarkonia, our method allows a unified description of the propagation of single heavy quarks as well as their bound states. To make calculations tractable, we deploy leading-order perturbation theory and consider the nonrelativistic limit. Various dynamical equations, such as the master equation for quantum Brownian motion and the time-evolution equation for heavy-quark and quarkonium forward correlators, are obtained from a single operator: the renormalized effective Hamiltonian. We are thus able to reproduce previous results of perturbative calculations of the drag force and the complex potential simultaneously. In addition, we present stochastic time-evolution equations for the heavy-quark and quarkonium wave function, which are equivalent to the dynamical equations. © 2013 American Physical Society. Source

Senaha E.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

The viable window to electroweak baryogenesis in a supersymmetric U(1) ′ model is studied in light of the 126 GeV Higgs boson. To investigate the decoupling of the sphaleron process in the broken phase, we evaluate the sphaleron rate and order of the electroweak phase transition. In this model, the electroweak phase transition is strongly first order due to the doublet-singlet Higgs mixing. Consequently, for typical parameter sets the Z′ boson has to be lighter than (150-300) GeV and thus leptophobic to be consistent with the collider bounds. We also estimate the baryon asymmetry of the Universe based on the closed-time-path formalism and find that the CP-violating source term fueled by the Z′-ino can generate sufficient baryon asymmetry. © 2013 American Physical Society. Source

Hibino T.,Nagoya University
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2011

The development of proton conductors has proceeded rapidly in recent years. A number of organic or inorganic materials show proton conductivities of ∼10-2Scm-1 at temperatures below 100°C. However, although there is great current demand for proton conductors capable of operating in the temperature range of 100400° C in practical applications, very few materials that can satisfy this demand have been reported to date. Acceptor-doped SnP2O7 are promising candidate materials because their proton conductivities reach >10-1Scm-1 in the temperature range of interest. This paper presents an overview of the current status of acceptor-doped SnP2O7, highlighting the mechanism and kinetics of proton conduction and the development of electrochemical devices using these materials. New insights for proton insertion and conduction are proposed that use electrochemical techniques. Two approaches to designing SnP2O7-based composite electrolytes with good mechanical properties have also been developed for different operating temperatures. In addition, the benefits of intermediate-temperature operation using these materials are discussed in terms of practical applications, especially in fuel cells, exhaust sensors, and solid catalysts. © 2011 The Ceramic Society of Japan. All rights reserved. Source

DeKosky B.J.,University of Texas at Austin | Kojima T.,University of Texas at Austin | Kojima T.,Nagoya University | Rodin A.,University of Texas at Austin | And 4 more authors.
Nature Medicine | Year: 2015

High-throughput immune repertoire sequencing has emerged as a critical step in the understanding of adaptive responses following infection or vaccination or in autoimmunity. However, determination of native antibody variable heavy-light pairs (VH-VL pairs) remains a major challenge, and no technologies exist to adequately interrogate the >1 × 106 B cells in typical specimens. We developed a low-cost, single-cell, emulsion-based technology for sequencing antibody VH-VL repertoires from >2 × 106 B cells per experiment with demonstrated pairing precision >97%. A simple flow-focusing apparatus was used to sequester single B cells into emulsion droplets containing lysis buffer and magnetic beads for mRNA capture; subsequent emulsion RT-PCR generated VH-VL amplicons for next-generation sequencing. Massive VH-VL repertoire analyses of three human donors provided new immunological insights including (i) the identity, frequency and pairing propensity of shared, or 'public', VL genes, (ii) the detection of allelic inclusion (an implicated autoimmune mechanism) in healthy individuals and (iii) the occurrence of antibodies with features, in terms of gene usage and CDR3 length, associated with broadly neutralizing antibodies to rapidly evolving viruses such as HIV-1 and influenza. © 2015 Nature America, Inc. All rights reserved. Source

This Review is a personal reflection on the research that led to the development of a method for growing gallium nitride (GaN) on a sapphire substrate. The results paved the way for the development of smart display systems using blue LEDs. The most important work was done in the mid to late 80s. The background to the author's work and the process by which the technology that enables the growth of GaN and the realization of p-type GaN was established are reviewed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Northoff G.,Ottawa Health Research Institute | Qin P.,Ottawa Health Research Institute | Nakao T.,Ottawa Health Research Institute | Nakao T.,Japan Society for the Promotion of Science | Nakao T.,Nagoya University
Trends in Neurosciences | Year: 2010

Studies in animals and humans have demonstrated intrinsic activity in the brain during the resting state. The concept of the default-mode network (DMN) - a set of brain regions in which resting-state activity (RSA) activity is reduced in response to external stimuli - recently raised much controversy concerning the psychological correlates of RSA. However, it remains unclear how RSA interacts with stimulus-induced activity. Here we review studies in humans and animals that address how RSA interacts with stimulus-induced activity; we also discuss, conversely, how stimulus-induced activity can modulate RSA. Psychologically, the rest-stimulus interaction is relevant to predicting subsequent behavioral and mental states. We conclude that a better understanding of the rest-stimulus interaction is likely to be crucial to the elucidation of the brain's contribution to mental states. © 2010 Elsevier Ltd. Source

Uwaha M.,Nagoya University
Journal of Crystal Growth | Year: 2011

The chirality conversion of crystals by grinding in an open system under circulation is studied. A generalized classical nucleation model and simple reaction-type models both show that steady perfect chirality conversion is possible if circulation is weak. By increasing the circulation rate λ, the amplification rate of a chirality imbalance becomes small and the imbalance of chiral products in the steady state decreases with λ. The chiral steady state disappears above a critical strength of circulation. The transition between the racemic and the chiral state is continuous in the system of achiral molecules and discontinuous in the system of chiral molecules. © 2010 Elsevier B.V. All rights reserved. Source

Seki T.,Nagoya University
Macromolecular Rapid Communications | Year: 2014

Photoresponsive azobenzene-containing systems ranging from molecular to macroscopic material levels have greatly been increasing their significance in materials chemistry. This review focuses on the studies on light induced or triggered motions in azobenzene liquid crystalline (LC) polymer films at mesoscopic and microscopic levels. Due to the cooperative nature of liquid crystalline materials, highly efficient photoalignment and photo-triggered migrating motions are realized in mostly repeated manners. Here, recent advances in surface-grafted LC polymer brushes, LC block copolymer films, and LC polymer films that exhibit mass migrations are overviewed. Such newly emerged photoresponsive systems are expected to provide new possibilities and applications in polymer thin film technologies. Due to the cooperative nature of liquid crystalline materials, highly efficient photoalignment and phototriggered migrating motions are realized. This review article focuses on the studies on photoinduced and photo-triggered motions in azobenzene liquid crystalline polymer films at mesoscopic and microscopic levels. Such newly emerged photoresponsive systems are expected to provide new possibilities and applications in polymer thin film technologies. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Hayashi Y.,Nagoya University
Diabetes, Obesity and Metabolism | Year: 2011

Multiple bioactive peptides are produced from proglucagon encoded by glucagon gene (Gcg). Glucagon is produced in islet α-cells through processing by prohormone convertase 2 (Pcsk2) and exerts its action through the glucagon receptor (Gcgr). Although it is difficult to produce a genetic model that harbours isolated glucagon deficiency without affecting the production of other peptides derived from proglucagon, three different animal models that harbour deficiencies in glucagon signalling have been generated by gene targeting strategy. Although both Pcsk2-/- and Gcgr-/- mice display lower blood glucose levels, homozygous glucagon-GFP knock-in mice (Gcggfp/gfp) display normoglycaemia despite complete glucagon deficiency. In Gcggfp/gfp mice, the metabolic impact of glucagon deficiency is probably ameliorated by lower plasma insulin levels and glucagon-independent mechanisms that maintain gluconeogeneis. As both Pcsk2-/- and Gcgr-/- mice exhibit increased production of glucagon-like peptide-1 (GLP-1), which is absent in Gcggfp/gfp, GLP-1 is the likely cause of the difference in metabolic impact of glucagon deficiency in these animal models. Although all the three models display islet 'α'-cell hyperplasia, the mechanisms involved remain to be elucidated. Studies using Pcsk2-/-, Gcgr-/- and Gcggfp/gfp mice, especially in combination with α-cell ablation models such as pancreas-specific aristaless-related homeobox (ARX) knockout mice, should further clarify the physiological and pathological roles of glucagon in the regulation of metabolism and the control of islet cell differentiation and proliferation. © 2011 Blackwell Publishing Ltd. Source

Sakakura A.,EcoTopia Science Institute | Ishihara K.,Nagoya University
Chemical Society Reviews | Year: 2011

The rational design of small but highly functional artificial catalysts is very important for practical organic synthesis. Asymmetric Lewis acid catalyses with non-covalent secondary interactions have been developed for enantioselective reactions. This tutorial review describes the concept, design and examples of asymmetric Cu(ii) catalyses for cycloaddition reactions based on intramolecular π-cation or n-cation interactions between the copper(ii) cation and auxiliary Lewis basic sites of the chiral ligands. © 2011 The Royal Society of Chemistry. Source

Shimizu K.-I.,Hokkaido University | Satsuma A.,Nagoya University
Energy and Environmental Science | Year: 2011

Design of solid acid catalysts is one of the key technologies to establish environmental friendly catalytic processes. Featuring cation-exchanged clay and metal salts of heteropolyacids as model solid acid catalysts, a strategy for design of active catalysts for green chemical and biomass conversion processes is discussed. The important role of solid Lewis acids was suggested in acetylation of alcohols with acetic anhydride by cation-exchanged clay, Friedel-Crafts acylation and alkylation of aromatic compounds with metal salts of heteropolyacids, and hydrolysis of cellulose into saccharides. The significant influence of reactor design and reaction conditions on dehydration of saccharides into 5-hydroxymethylfurfural (HMF) is also discussed. © 2011 The Royal Society of Chemistry. Source

Tamura M.,Kao Corporation | Shimizu K.-I.,Hokkaido University | Satsuma A.,Nagoya University
Applied Catalysis A: General | Year: 2012

Acid/base properties (type, strength, number) of a wide range of metal oxides were studied by IR (infra-red) spectroscopy. Ammonia, pyridine and CD 3CN were used as probe molecules for acidity measurement. CO 2, CHCl 3, benzaldehyde and nitrobenzene were used for basicity measurement. Pyridine for the nature and number of acid sites, CD 3CN for the strength of acid sites, CHCl 3 for the strength of basic sites and nitrobenzene for the number of basic sites were found to be suitable probes. The absorption coefficients of pyridine for acidic sites and nitrobenzene for basic sites, estimated for various metal oxides by IR coupled with mass spectrometry, were within ±10% of the average value, which indicates that the integrated molar extinction coefficients could be used for semi-quantification of acid/base sites of various oxides samples. The comprehensive IR results in this study will be available to characterize properties of Lewis and Bronsted acid sites and basic sites on metal oxides by a simple IR experiment. © 2012 Elsevier B.V. Source

Nakamura S.,Nagoya University | Ooguri H.,California Institute of Technology | Ooguri H.,University of Tokyo
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We define an effective temperature and study its properties for a class of out-of-equilibrium steady states in a heat bath. Our analysis is based on the anti-de Sitter spacetime/conformal field theory (AdS/CFT) correspondence, and examples include systems driven by applied electric fields and branes dragged in plasmas. We found that the effective temperature can be lower than that of the heat bath and that the out-of-equilibrium noise can be smaller than that in equilibrium. We show that a generalization of the fluctuation-dissipation relation holds for the effective temperature. In particular, we generalize the Johnson-Nyquist relation for a large electric field. © 2013 American Physical Society. Source

Kaneyoshi T.,Nagoya University
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2015

The phase diagram and magnetizations in two transverse Ising nanoislands with different (hexagonal and square) structures which are consisted of the two layers are examined by using the effective-field theory with correlations. The effects of interlayer coupling and two transverse fields at the center and the perimeter atoms on them are examined. We present some characteristic phenomena in the magnetic properties which come from the frustration induced by them. © 2014 Elsevier B.V. All rights reserved. Source

Mizuno T.,Nagoya University
International Journal of Alzheimer's Disease | Year: 2012

Neuroinflammation is involved in the pathogenesis of Alzheimer's disease (AD). Microglia, macrophage-like resident immune cells in the brain, play critical roles in the inflammatory aspects of AD. Microglia may be activated by oligomeric and fibrillar species of amyloid β(Aβ) that are constituents of senile plaques and by molecules derived from degenerated neurons, such as purines and chemokines, which enhance their migration and phagocytosis. The main neurotoxic molecules produced by activated microglia may be reactive oxygen species, glutamate, and inflammatory cytokines such as tumor-necrosis-factor-α and interleukin-(IL-) 1β These molecules differentially induce neurotoxicity. Aβ itself directly damages neurons. In terms of neuroprotective properties, microglia treated with fractalkine or IL-34 attenuate Aβ neurotoxicity by Aβ clearance and the production of antioxidants. Therefore, regulation of the microglial role in neuroprotection may be a useful therapeutic strategy for AD. Copyright © 2012 Tetsuya Mizuno. Source

Matsumoto T.,Nagoya University | Yoshida K.,Kyoto University
Journal of High Energy Physics | Year: 2015

Abstract: We further study integrable deformations of the AdS5×S5 superstring by following the Yang-Baxter sigma model approach with classical r-matrices satisfying the classical Yang-Baxter equation (CYBE). Deformed string backgrounds specified by r-matrices are considered as solutions of type IIB supergravity, and therefore the relation between gravitational solutions and r-matrices may be called the gravity/CYBE correspondence. In this paper, we present a family of string backgrounds associated with a classical r-matrices carrying two parameters and its three-parameter generalization. The two-parameter case leads to the metric and NS-NS two-form of a solution found by Hubeny-Rangamani-Ross [hep-th/0504034] and another solution in [arXiv:1402.6147]. For all of the backgrounds associated with the three-parameter case, the metric and NS-NS two-form are reproduced by performing TsT transformations and S-dualities for the undeformed AdS5 × S5 background. As a result, one can anticipate the R-R sector that should be reproduced via a supercoset construction. © 2015, The Author(s). Source

Zinchenko A.,Nagoya University
Advances in Colloid and Interface Science | Year: 2016

In a living cell, long genomic DNA is strongly compacted and exists in the environment characterized by a dense macromolecular crowding, high concentrations of mono- and divalent cations, and confinement of ca. 10. μm size surrounded by a phospholipid membrane. Experimental modelling of such complex biological system is challenging but important to understand spatiotemporal dynamics and functions of the DNA in cell. The accumulated knowledge about DNA condensation/compaction in conditions resembling those in the real cell can be eventually used to design and construct partly functional "artificial cells" having potential applications in drug delivery systems, gene therapy, and production of synthetic cells. In this review, I would like to overview the past progress in our understanding of the DNA conformational behavior and, in particular, DNA condensation/compaction phenomenon and its relation to the DNA biological activity. This understanding was gained by designing relevant experimental models mimicking DNA behavior in the environment of living cell. Starting with a brief summary of classic experimental systems to study DNA condensation/compaction, in later parts, I highlight recent experimental methodologies to address the effects of macromolecular crowding and nanoscale and microscale confinements on DNA conformation dynamics. All the studies are discussed in the light of their relevance to DNA behavior in living cells, and future prospects of the field are outlined. © 2016 Elsevier B.V. Source

Akamatsu Y.,Nagoya University
Physical Review C - Nuclear Physics | Year: 2015

A Langevin equation of heavy quarks in high-temperature quark-gluon plasma is derived. The dynamics of heavy quark color is coupled with the phase space dynamics and causes a macroscopic superposition state of heavy quark momentum. Decoherence of the superposition state allows one to use a classical description. The time scale of decoherence gives an appropriate discretization time scale Δt∼M/CFγ for the classical Langevin equation, where M is heavy quark mass and γ is heavy quark momentum diffusion constant. © 2015 American Physical Society. ©2015 American Physical Society. Source

Inoue T.,Aoyama Gakuin University | Inutsuka S.-I.,Nagoya University
Astrophysical Journal | Year: 2012

Using three-dimensional magnetohydrodynamic simulations, including the effects of radiative cooling/heating, chemical reactions, and thermal conduction, we investigate the formation of molecular clouds in the multi-phase interstellar medium. As suggested by recent observations, we consider the formation of molecular clouds due to accretion of H I clouds. Our simulations show that the initial H I medium is piled up behind the shock waves induced by accretion flows. Since the initial medium is highly inhomogeneous as a consequence of thermal instability, a newly formed molecular cloud becomes very turbulent owing to the development of the Richtmyer-Meshkov instability. The kinetic energy of the turbulence dominates the thermal, magnetic, and gravitational energies throughout the entire 10 Myr evolution. However, the kinetic energy measured using CO-fraction-weighted densities is comparable to the other energies, once the CO molecules are sufficiently formed as a result of UV shielding. This suggests that the true kinetic energy of turbulence in molecular clouds as a whole can be much larger than the kinetic energy of turbulence estimated using line widths of molecular emission. We find that clumps in a molecular cloud show the following statistically homogeneous evolution: the typical plasma β of the clumps is roughly constant 〈β〉 ≃ 0.4; the size-velocity dispersion relation is Δv ≃ 1.5 km s-1 (l/1 pc)0.5, irrespective of the density; the clumps evolve toward magnetically supercritical, gravitationally unstable cores; and the clumps seem to evolve into cores that satisfy the condition for fragmentation into binaries. These statistical properties may represent the initial conditions of star formation. © 2012. The American Astronomical Society. All rights reserved.. Source

Kamigaito M.,Nagoya University
Polymer Journal | Year: 2011

This review presents a short overview of recent developments in metal-catalyzed living radical polymerization, mainly focusing on our recent research studies related to the subject. Metal-catalyzed living radical polymerization or atom transfer radical polymerization, which was originally developed via evolution of the metal-catalyzed Kharasch or atom transfer radical addition to chain-growth polymerization via reversible activation, has now been widely developed in many aspects. The effective metal catalysts include various transition metals, such as ruthenium, copper, iron and nickel, and highly active and versatile catalytic systems have been developed by designing ligands, applying lower oxidation metal species and using additives to widen the scope of controllable monomers and to minimize the amount of metal catalysts and the residual metals in the products. The development of the initiating systems has enabled the synthesis of a wide variety of novel, well-defined polymers, including end-functionalized, block, graft and star polymers, but also more complicated polymers possessing multiple controlled structures. Furthermore, metal-catalyzed living radical polymerization has been judiciously combined with stereospecific radical polymerization based on the use of polar solvents or Lewis acid additives, resulting in the dual control of the molecular weight and the tacticity of the resulting polymers and enabling the preparation of stereoblock and stereogradient polymers. © The Society of Polymer Science, Japan (SPSJ) All rights reserved. Source

Moriyama S.,Nagoya University | Nosaka T.,Kyoto University
Journal of High Energy Physics | Year: 2015

It was known that the ABJM matrix model is dual to the topological string theory on a Calabi-Yau manifold. Using this relation it was possible to write down the exact instanton expansion of the partition function of the ABJM matrix model. The expression consists of a universal function constructed from the free energy of the refined topological string theory with an overall topological invariant characterizing the CalabiYau manifold. In this paper we explore two other superconformal Chern-Simons theories of the circular quiver type. We find that the partition function of one theory enjoys the same expression from the refined topological string theory as the ABJM matrix model with different topological invariants while that of the other is more general. We also observe an unexpected relation between these two theories.[Figure not available: see fulltext.] © 2015, The Author(s). Source

Makela J.J.,University of Illinois at Urbana - Champaign | Otsuka Y.,Nagoya University
Space Science Reviews | Year: 2012

We present a review of the current state of understanding regarding two classes of irregularities causing mesoscale structuring (hundreds of kilometers) in the nighttime ionosphere at low- and mid-latitudes. Additionally, current state of understanding of equatorial plasma bubbles at low latitudes, and medium-scale traveling ionospheric disturbances at mid latitudes and their relationship to possible seeding from lower altitudes are described. In each case, well-developed linear theories exist to explain the general properties of the irregularities. However, these linear theories have growth rates too low to explain the actual observations, giving rise to the need to invoke seeding mechanisms. We describe the observational databases that have been compiled over the decades and discuss possible coupling and seeding mechanisms that would overcome the low growth rate and explain the observed structuring at the mesoscale. Future research directions are also briefly discussed. © 2011 Springer Science+Business Media B.V. Source

Akasaki I.,Meijo University | Akasaki I.,Nagoya University
Angewandte Chemie - International Edition | Year: 2015

In the beginning there was light: Mankind has pursued light sources since ancient times, starting with flames, then the development of electric light bulbs much later, and most recently the production of light-emitting diodes. Isami Akasaki describes the historical progress that led to the invention of the first blue LED and related optical devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

The phase diagrams and magnetizations of two nanoscaled thin films with dilution at the surfaces are investigated by the use of the effective field theory with correlations. In particular, the effects of interlayer coupling between the surface and the next inner layer on them are discussed for the two thin films with a thickness L (L=3 and L=4). A number of interesting phenomena have been found in the phase diagrams and the thermal variations of magnetizations, such as a broad maximum in the variation of transition temperature and the behavior of compensation point, showing completely different features between the two systems. © 2012 Elsevier B.V. All rights reserved. Source

The cysteine protease cathepsin K (CatK) has been implicated in the pathogenesis of cardiovascular disease. We sought to determine the link between atrial fibrillation (AF) and plasma CatK levels and to investigate the expression of and therapeutic target for CatK in vivo and in vitro. Plasma CatK and extracellular matrix protein peptides (intact procollagen type I of N-terminal propeptide; carboxyl-terminal telopeptide of type I collagen [ICTP]) were measured in 209 consecutive patients with AF (paroxysmal AF, 146; persistent AF, 63) and 112 control subjects. In addition, the regulation of CatK expression was investigated in vivo and vitro. Patients with AF had higher plasma CatK and ICTP levels than did control subjects. Patients with persistent AF had higher levels of plasma CatK and ICTP than did patients with paroxysmal AF. CatK was correlated with ICTP concentration and left atrial diameter in all subjects. In rabbits, superoxide production, CatK activity, fibrosis, and the levels of atrial tissue angiotensin II, angiotensin type 1 receptor, gp91phox, phospho-p38 mitogen-activated protein kinase, and CatK were greater in those with tachypacing-induced AF than in controls, and these changes were reversed with angiotensin type 1 receptor antagonist. Olmesartan and mitogen-activated protein kinase inhibitor decreased the CatK expression induced by angiotensin II in rat neonatal myocytes. These data indicated that increased plasma CatK levels are linked with the presence of AF. Angiotensin type 1 receptor antagonist appears to be effective in alleviating atrial fibrosis in a rabbit AF model, partly reducing angiotensin type 1 receptor-p38mitogen-activated protein kinase-dependent and -independent CatK activation, thus preventing AF. Source

Tsuchiya Y.,Nagoya University
Nature Chemical Biology | Year: 2016

Striga spp. (witchweed) is an obligate parasitic plant that attaches to host roots to deplete them of nutrients. In Sub-Saharan Africa, the most destructive Striga species, Striga hermonthica, parasitizes major food crops affecting two-thirds of the arable land and over 100 million people. One potential weakness in the Striga infection process is the way it senses the presence of a host crop. Striga only germinates in the presence of the plant hormone strigolactone, which exudes from a host root. Hence small molecules that perturb strigolactone signaling may be useful tools for disrupting the Striga lifecycle. Here we developed a chemical screen to suppress strigolactone signaling in the model plant Arabidopsis. One compound, soporidine, specifically inhibited a S. hermonthica strigolactone receptor and inhibited the parasite's germination. This indicates that strigolactone-based screens using Arabidopsis are useful in identifying lead compounds to combat Striga infestations. © 2016 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. Source

Matsuzaki S.,Kyoto Sangyo University | Yamawaki K.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We find that a holographic walking technicolor model has a limit ("conformal limit") where the technidilaton (TD) becomes a massless Nambu-Goldstone boson of the scale symmetry with its nonzero finite decay constant F•0, which naturally realizes a light TD, say at 125 GeV, near the limit. In such a light TD case, we find that F• is uniquely determined by the technipion decay constant Fπ independently of the holographic parameters: F•/F π√2NTF, with NTF being the number of technifermions. We show that the holographic TD is consistent with a new boson at 125 GeV recently discovered at the LHC. © 2012 American Physical Society. Source

Ogata Y.,Nagoya University
Radiation Measurements | Year: 2013

Vast amounts of radioactive materials were released to environment by the nuclear disaster of Fukushima Daiichi Nuclear Plant (NPP) in March 2011. A small amount of radionuclides were detected in rainwater even at Nagoya, 440 km far from the NPP. We report here results for fallouts in the unit of Bq/m 2 at Nagoya, which are estimated from activity concentrations (Bq/cm3) and precipitations (mm) of rainwaters collected in the period from 20 March to 12 May 2011. © 2012 Elsevier Ltd. All rights reserved. Source

Buscemi F.,Nagoya University
Physical Review Letters | Year: 2012

Departing from the usual paradigm of local operations and classical communication adopted in entanglement theory, we study here the interconversion of quantum states by means of local operations and shared randomness. A set of necessary and sufficient conditions for the existence of such a transformation between two given quantum states is given in terms of the payoff they yield in a suitable class of nonlocal games. It is shown that, as a consequence of our result, such a class of nonlocal games is able to witness quantum entanglement, however weak, and reveal nonlocality in any entangled quantum state. An example illustrating this fact is provided. © 2012 American Physical Society. Source

Mizushima T.,Okayama University | Sato M.,University of Tokyo | Sato M.,Nagoya University | MacHida K.,Okayama University
Physical Review Letters | Year: 2012

We here demonstrate that the superfluid He3-B under a magnetic field in a particular direction stays topological due to a discrete symmetry, that is, in a symmetry protected topological order. Because of the symmetry protected topological order, helical surface Majorana fermions in the B phase remain gapless and their Ising spin character persists. We unveil that the competition between the Zeeman magnetic field and dipole interaction involves an anomalous quantum phase transition in which a topological phase transition takes place together with spontaneous symmetry breaking. Based on the quasiclassical theory, we illustrate that the phase transition is accompanied by anisotropic quantum criticality of spin susceptibilities on the surface, which is detectable in NMR experiments. © 2012 American Physical Society. Source

Ichiki K.,Nagoya University | Takada M.,University of Tokyo
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We study the spherical, top-hat collapse model for a mixed dark matter model including cold dark matter (CDM) and massive neutrinos of mass scales ranging from m ν0.05 to a few 0.1eV, the range of lower and upper bounds implied from the neutrino oscillation experiments and the cosmological constraints. To develop this model, we properly take into account relative differences between the density perturbation amplitudes of different components (radiation, baryon, CDM, and neutrinos) around the top-hat CDM overdensity region assuming the adiabatic initial conditions. Furthermore, we solve the linearized Boltzmann hierarchy equations to obtain time evolution of the linearized neutrino perturbations, yet including the effect of nonlinear gravitational potential due to the nonlinear CDM and baryon overdensities in the late stage. We find that the presence of massive neutrinos slows down the collapse of CDM (plus baryon) overdensity; however, the neutrinos cannot fully catch up with the nonlinear CDM perturbation due to its large free-streaming velocity for the ranges of neutrino masses and halo masses we consider. We find that, just like CDM models, the collapse time of CDM overdensity is well monitored by the linear theory extrapolated overdensity of CDM plus baryon perturbation, smoothed with a given halo mass scale, if taking into account the suppression effect of the massive neutrinos on the linear growth rate. Using these findings, we argue that the presence of massive neutrinos of mass scales 0.05 or 0.1eV may cause a significant decrease in the abundance of massive halos compared to the model without the massive neutrinos, e.g., by 25% or factor2, respectively, for halos with 1015M ™ and at z=1. © 2012 American Physical Society. Source

Hayasaka K.,Nagoya University
Journal of Physics: Conference Series | Year: 2013

We report the results and prospects on the τ lepton flavor violation at Belle and Belle II. Source

Matsuzaki S.,Kyoto Sangyo University | Yamawaki K.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

The techni-dilaton (TD) is predicted in walking technicolor (WTC) arising as a pseudo-Nambu-Goldstone boson associated with the approximate scale symmetry spontaneously broken by techni-fermion condensation. The TD mass is therefore smaller than those of other techni-hadrons on the order of several TeVs, small enough to be within reach of the current LHC search. We present a new method to derive the TD couplings directly from the Ward-Takahashi identities, which enables us to explicitly calculate the quantities relevant to the TD LHC signatures. To set definite benchmarks, we take one-doublet and one-family models of WTC and discuss the TD signatures at the LHC, in comparison with those of the standard model (SM) Higgs. It is shown that the TD in the one-doublet model is invisible at the LHC, while the TD signals in the one-family model can be found as a large excess relative to the SM Higgs at around 125GeV only in the diphoton channel. © 2012 American Physical Society. Source

Hatakeyama N.,Aichi Medical University | Matsuda N.,Nagoya University
Current Pharmaceutical Design | Year: 2014

Systemic inflammatory response syndrome (SIRS) is triggered by various factors such as surgical operation, trauma, burn injury, ischemia, pancreatitis and bacterial translocation. Sepsis is a SIRS associated with bacterial infection. SIRS and sepsis tend to trigger excessive production of inflammatory cytokines and other inflammatory molecules and induce multiple organ failure, such as acute lung injury, acute kidney injury and inflammatory cardiac injury. Epithelial and endothelial cells in some major organs express inflammatory receptors on the plasma membrane and work as alert cells for inflammation, and regulation of these alert cells could have a relieving effect on the inflammatory response. In inflammatory conditions, initial cardiac dysfunction is mediated by decreased preload and adequate infusion therapy is required. Tachyarrhythmia is a complication of inflammatory conditions and early control of the inflammatory reaction would prevent the structural remodeling that is resistant to therapies. Furthermore, there seems to be crosstalk between major organs with a central focus on the kidneys in inflammatory conditions. As an alert cell strategy, volatile anesthetics, sevoflurane and isoflurane, seem to have anti-inflammatory effects, and both experimental and clinical studies have shown the beneficial effects of these drugs in various settings of inflammatory conditions. On the other hand, in terms of intravenous anesthetics, propofol and ketamine, their current status is still controversial as there is a lack of confirmatory evidence on whether they have an organ-protective effect in inflammatory conditions. The local anesthetic lidocaine suppressed inflammatory responses upon both systemic and local administration. For the control of inflammatory conditions, anesthetic agents may be a target of drug development in accordance with other treatments and drugs. © 2014 Bentham Science Publishers. Source

Kaneyoshi T.,Nagoya University
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2013

Thickness (L) dependence for phase diagrams in nanoscaled thin films with bond and site dilutions at the surfaces, described by the transverse Ising model, are investigated by the use of the effective field theory with correlations, in order to clarify whether some characteristic phenomena found in the previous works for the most thin films (L=3) can be found by increasing the thickness in thin films. We find that the approaches to bulk values, when increasing L, are rather different between the two systems with site and bond dilutions at the surfaces, when the ratio p (p=ΩS/Ω, where ΩS and Ω are the transverse fields at the surfaces and in the inner layer) is given by p=1.0. When p=6.0, many characteristic phenomena can be obtained in the phase diagrams. Unconventional phenomena of phase diagram have also been obtained, when the value of p is changed in the thin films with a very low site or bond concentration q (q=0.1) at the surfaces. © 2013 Elsevier B.V. Source

Nakosai S.,University of Tokyo | Tanaka Y.,Nagoya University | Nagaosa N.,University of Tokyo | Nagaosa N.,RIKEN
Physical Review Letters | Year: 2012

We theoretically study a possible topological superconductivity in the interacting two layers of Rashba systems, which can be fabricated by the heterostructures of semiconductors and oxides. The hybridization, which induces the gap in the single particle dispersion, and the electron-electron interaction between the two layers leads to the novel phase diagram of the superconductivity. It is found that the topological superconductivity without breaking time-reversal symmetry is realized when (i) the Fermi energy is within the hybridization gap, and (ii) the interlayer interaction is repulsive, both of which can be satisfied in realistic systems. Edge channels are studied in a tight-binding model numerically, and the several predictions on experiments are also given. © 2012 American Physical Society. Source

A comprehensive analysis of the extended emission-line region (EELR) around quasars is presented. A new Subaru/Suprime-Cam observation is combined with a literature search, resulting in a compilation of 81 EELR measurements for type-1 and type-2 quasars with an associated active galactic nucleus (AGN) and host galaxy properties. It is found that the EELR phenomenon shows clear correlation with the Eddington ratio, which links EELR to the constituents of principal component 1, or eigenvector 1, of the AGN emission correlations. We also find that EELR is preferentially associated with gas-rich, massive blue galaxies. This supports the idea that the primary determinant of EELR creation is gas availability and that the gas may be brought in by galaxy merger, triggering the current star formation as well as AGN activity, and also gives an explanation for the fact that most luminous EELRs are found around radio-loud sources with low Eddington ratio. By combining all the observations, it is suggested that EELR quasars occupy the massive blue corner of the green valley, the AGN realm, on the galaxy color-stellar mass diagram. Once a galaxy is pushed to this corner, an activated AGN would create an EELR by energy injection into the interstellar gas and eventually blow it away, leading to star formation quenching. The results presented here provide a piece of evidence for the presence of such an AGN feedback process, which may play a leading role in the co-evolution of galaxies and central super-massive black holes. © 2012 The American Astronomical Society. All rights reserved. Source

Ouchi N.,Nagoya University | Parker J.L.,Boston University | Lugus J.J.,Boston University | Walsh K.,Boston University
Nature Reviews Immunology | Year: 2011

The worldwide epidemic of obesity has brought considerable attention to research aimed at understanding the biology of adipocytes (fat cells) and the events occurring in adipose tissue (fat) and in the bodies of obese individuals. Accumulating evidence indicates that obesity causes chronic low-grade inflammation and that this contributes to systemic metabolic dysfunction that is associated with obesity-linked disorders. Adipose tissue functions as a key endocrine organ by releasing multiple bioactive substances, known as adipose-derived secreted factors or adipokines, that have pro-inflammatory or anti-inflammatory activities. Dysregulated production or secretion of these adipokines owing to adipose tissue dysfunction can contribute to the pathogenesis of obesity-linked complications. In this Review, we focus on the role of adipokines in inflammatory responses and discuss their potential as regulators of metabolic function. © 2011 Macmillan Publishers Limited. All rights reserved. Source

Murata T.,Nagoya University | Murata T.,Aichi Cancer Center Research Institute
Microbiology and Immunology | Year: 2014

The Epstein-Barr virus (EBV) is a human gamma-herpesvirus that is implicated in various types of proliferative diseases. Upon infection, it predominantly establishes latency in B cells and cannot ever be eradicated; it persists for the host's lifetime. Reactivation of the virus from latency depends on expression of the viral immediate-early gene, BamHI Z fragment leftward open reading frame 1 (BZLF1). The BZLF1 promoter normally exhibits only low basal activity but is activated in response to chemical or biological inducers, such as 12-O-tetradecanoylphorbol-13-acetate, calcium ionophore, histone deacetylase inhibitor, or anti-Ig. Transcription from the BZLF1 promoter is activated by myocyte enhancer factor 2, specificity protein 1, b-Zip type transcription factors and mediating epigenetic modifications of the promoter, such as histone acetylation and H3K4me3. In contrast, repression of the promoter is mediated by transcriptional suppressors, such as ZEB, ZIIR-BP, and jun dimerization protein 2, causing suppressive histone modifications like histone H3K27me3, H3K9me2/3 and H4K20me3. Interestingly, there is little CpG DNA methylation of the promoter, indicating that DNA methylation is not crucial for suppression of BZLF1. This review will focus on the molecular mechanisms by which the EBV lytic switch is controlled and discuss the physiological significance of this switching for its survival and oncogenesis. © 2014 The Societies and Wiley Publishing Asia Pty Ltd. Source

Masunaga H.,Nagoya University | L'Ecuyer T.S.,Colorado State University
Journal of Climate | Year: 2011

The equatorial asymmetry of the east Pacific intertropical convergence zone (ITCZ) is explored on the basis of an ocean surface heat budget analysis carried out with a variety of satellite data products. The annual mean climatology of absorbed shortwave flux exhibits a pronounced meridional asymmetry due to a reduction of insolation by high clouds in the north ITCZ. Ocean mixed layer advection has the largest, if not exclusive, effect of counteracting this shortwave-exerted asymmetry. Other heat fluxes, in particular latent heat flux, predominate over the advective heat flux in magnitude but are secondary with respect to equatorial asymmetry. The asymmetry in advective heat flux stems from a warm pool off the Central American coast and, to a lesser extent, the North Equatorial Counter Current, neither of which exist in the Southern Hemisphere. The irregular continental geography presumably comes into play by generating a warm pool north of the equator and bringing cold waters to the south in the far eastern Pacific. In addition to the annual climatology, the north-south contrast in the seasonal cycle of surface heat flux is instrumental in sustaining the north ITCZ throughout the year. The northeast Pacific is exposed to a seasonal cycle that is considerably weaker than that in the southeast Pacific, arising from multiple causes including the finite eccentricity of the earth's orbit and meridional gradient in mixed layer absorptivity. Simple experiments generating synthetic sea surface temperature (SST) illustrate that the muted seasonal cycle of heat flux forcing moderates the SST seasonal variability in the northeast Pacific and thus allows the north ITCZ to persist year round. Existing theories on the ITCZ asymmetry are briefly examined in light of the present findings. © 2011 American Meteorological Society. Source

Takenaka K.,Nagoya University
Science and Technology of Advanced Materials | Year: 2012

Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over -30 ppm K -1. Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade. © 2012 National Institute for Materials Science. Source

Gurtin M.E.,Carnegie Mellon University | Ohno N.,Nagoya University
Journal of the Mechanics and Physics of Solids | Year: 2011

This paper develops a gradient theory of single-crystal plasticity based on a system of microscopic force balances, one balance for each slip system, derived from the principle of virtual power, and a mechanical version of the second law that includes, via the microscopic forces, work performed during plastic flow. When combined with thermodynamically consistent constitutive relations the microscopic force balances become nonlocal flow rules for the individual slip systems in the form of partial differential equations requiring boundary conditions. Central ingredients in the theory are densities of (geometrically necessary) edge and screw dislocations, densities that describe the accumulation of dislocations, and densities that characterize forest hardening. The form of the forest densities is based on an explicit kinematical expression for the normal Burgers vector on a slip plane. © 2010 2010 Elsevier Ltd. All rights reserved. Source

Okubo H.,Nagoya University
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2012

Research and development results of enhancement techniques of electrical insulation performance for higher electric field application in power transmission/substation equipment, such as transformers, switchgears and cables, are described, especially based on the view point of dielectric materials. Firstly, the electric field analysis, field optimization and field measurement techniques are introduced to discuss higher electric field stress applications in power equipment. Secondly, material types, including gases, liquids, solids, vacuum and their composite systems are discussed to make power equipment with higher insulation performance, lower losses, lower environmental impact and higher reliability. In the process of development, a highly sophisticated new approach to clarify the physical mechanisms of partial discharges was developed and applied. By the introduction and applications of the above mentioned new electrical insulation techniques based on dielectric materials, concepts of future power equipment with higher electric field stress are proposed. This paper is based on the Whitehead Memorial Lecture given at the IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP) 2011 in Cancun, Mexico. © 2012 IEEE. Source

Horii Y.,Nagoya University
Acta Physica Polonica B | Year: 2012

Precision of the determination of the CP-violating angle φ3 has been improved by various measurements on the decays B plusmn; → D (*)K (*)±. In this report, we show several recent updates which provide important ingredients in determining φ3. Source

Tanimoto M.,Nagoya University
Signal Processing: Image Communication | Year: 2012

FTV (Free-viewpoint Television) enables us to view a 3D scene by freely changing our viewpoint. FTV is the ultimate 3DTV with infinite number of views and ranked as the top of visual media. We realized FTV by developing various types of ray capture, processing and display technologies. We have also realized all-around ray-reproducing 3DTV. The international standardization of FTV has been conducted in MPEG. The first phase of FTV was MVC (Multi-view Video Coding) and the second phase is 3DV (3D Video). © 2012 Elsevier B.V. All rights reserved. Source

Zinchenko A.A.,Nagoya University
Polymer Science - Series C | Year: 2012

During the past decade biomacromolecules attracted tremendous attention as versatile materials for self-assembly, nanoconstruction, and templating. An increasing number of reports highlights creative applications of DNA, proteins, and their assemblies for construction of materials, which synthesis by traditional top-down techniques is not possible. This review summarizes various aspects of the application of biomacromolecules and their self-organized structures for building-up inorganic nanomaterials of different complicity by metallization or mineralization of natural templates. The central focus of the review is given to DNA-templated and DNA-directed synthesis of nanostructures, as the progress in the utilization of DNA for nanoconstruction is most considerable. © 2012 Pleiades Publishing, Ltd. Source

The comment by Nicholson (2011a) questions the "consistency" of the "definition" of the "biological end-member" used by Kaiser (2011a) in the calculation of oxygen gross production. "Biological end-member" refers to the relative oxygen isotope ratio difference between photosynthetic oxygen and Air-O2 (abbreviated 17δP and 18δP for 17O/16O and 18O/16O, respectively). The comment claims that this leads to an overestimate of the discrepancy between previous studies and that the resulting gross production rates are "30% too high". Nicholson recognises the improved accuracy of Kaiser's direct calculation ("dual-delta") method compared to previous approximate approaches based on 17O excess (17Δ) and its simplicity compared to previous iterative calculation methods. Although he correctly points out that differences in the normalised gross production rate (g) are largely due to different input parameters used in Kaiser's "base case" and previous studies, he does not acknowledge Kaiser's observation that iterative and dual-delta calculation methods give exactly the same g for the same input parameters (disregarding kinetic isotope fractionation during air-sea exchange). The comment is based on misunderstandings with respect to the "base case" 17δP and 18δP values. Since direct measurements of 17δP and 18δPdo not exist or have been lost, Kaiser constructed the "base case" in a way that was consistent and compatible with literature data. Nicholson showed that an alternative reconstruction of 17δP gives g values closer to previous studies. However, unlike Nicholson, we refrain from interpreting either reconstruction as a benchmark for the accuracy of g. A number of publications over the last 12 months have tried to establish which of these two reconstructions is more accurate. Nicholson draws on recently revised measurements of the relative 17O/16O difference between VSMOW and Air-O2 ( 17δVSMOW; Barkan and Luz, 2011), together with new measurements of photosynthetic isotope fractionation, to support his comment. However, our own measurements disagree with these revised 17δVSMOW values. If scaled for differences in 18δVSMOW, they are actually in good agreement with the original data (Barkan and Luz, 2005) and support Kaiser's "base case" g values. The statement that Kaiser's g values are "30% too high" can therefore not be accepted, pending future work to reconcile different 17δVSMOW measurements. Nicholson also suggests that approximated calculations of gross production should be performed with a triple isotope excess defined as 17Δ#≡ ln (1+ 17δ)-λ ln(1+18δ), with λ Combining double low line θR Combining double low line ln(1+ 17εR ) / ln(1+18εR). However, this only improves the approximation for certain 17δP and 18δP values, for certain net to gross production ratios (f) and for certain ratios of gross production to gross Air-O2 invasion (g). In other cases, the approximated calculation based on 17Δ† ≡17δ - κ 18δ with κ Combining double low line γR Combining double low line 17εR/18εR (Kaiser, 2011a) gives more accurate results. © Author(s) 2012. Source

Yamamoto Y.,Nagoya University
Chemical Reviews | Year: 2012

The transition-metal-catalyzed cycloisomerizations of α,ω- dienes have been continuously investigated because such cycloisomerization reactions provide atom-economical routes to various carbo- and heterocyclic compounds. Nevertheless, early catalytic systems generally lacked the requisite isomeric selectivity and the general substrate scope. Considerable efforts devoted to the identification of selective and versatile catalyst systems have led to recent developments of late-transitionmetal-catalyzed cycloisomerizations of 1,6-dienes with wide substrate scope and high isomeric selectivity, including asymmetric cycloisomerizations. There is, nevertheless, room for improvement of the substrate scope, the isomeric selectivity, and the enantiomeric selectivity. In addition, by combining the newly developed catalytic systems with state-of-the-art techniques such as a microwave treatment and the use of unique solvent systems, further progress in diene cycloisomerizations is being made possible. For xample, recyclable catalyst systems for the 1,6-diene cycloisomerization have been established using ionic liquids and scCO2 as solvents. Further investigations into the utilization of heterogeneous catalysts and carbophilic Lewis acid catalysts as well as less examined substrates would result in the development of unprecedented modes of cycloisomerization and would increase the synthetic value of α,ω-diene cyclization. © 2012 American Chemical Society. Source

Yamamoto K.,Nagoya University
Communications in Computational Physics | Year: 2013

A diesel particulate filter (DPF) is a key technology to meet future emission standards of particulate matters (PM), mainly soot. It is generally consists of a wall-flow type filter positioned in the exhaust stream of a diesel vehicle. It is difficult to simulate the thermal flow in DPF, because we need to consider the soot deposition and combustion in the complex geometry of filter wall. In our previous study, we proposed an approach for the conjugate simulation of gas-solid flow. That is, the gas phase was simulated by the lattice Boltzmann method (LBM), coupled with the equation of heat conduction inside the solid filter substrate. However, its numerical procedure was slightly complex. In this study, to reduce numerical costs, we have tested a new boundary condition with chemical equilibrium in soot combustion at the surface of filter substrate. Based on the soot oxidation rate with catalysts evaluated in experiments, the lattice Boltzmann simulation of soot combustion in the catalyzed DPF is firstly presented to consider the process in the after-treatment of diesel exhaust gas. The heat and mass transfer is shown to discuss the effect of catalysts. © 2013 Global-Science Press. Source

Arai T.,High Energy Accelerator Research Organization | Arai T.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

A scalar field theory with quartic self-interaction in de Sitter space is studied using the two-particle irreducible effective action formalism. This formalism partially resums infinite series of loop diagrams and enables us to circumvent the IR divergence problem for a massless minimally coupled scalar field in de Sitter space. However, due to its nonperturbative nature, the renormalization prescription is a nontrivial task. To calculate physical quantities, an appropriate renormalization prescription is required. In this paper, we will show that the minimal subtraction-like scheme is possible at the Hartree-Fock truncation of the two-particle irreducible effective action in a general curved space, and infinite series of divergent terms are needed as counterterms. The infrared effects on the physical mass and phase structure are calculated. © 2012 American Physical Society. Source

Because the biopsy specimen of extrahepatic bile duct carcinoma (EHBDC) is small and shows reactive changes, the histological distinction between malignant and benign tissue can be difficult. Recent studies reported that S100P and insulin-like growth factor II mRNA-binding protein 3 (IMP3) were not only diagnostic molecules but also prognostic biomarkers in several organs. The objective of this study is to clarify the diagnostic and prognostic value of immunohistochemical expression of S100P and IMP3 in transpapillary biliary forceps biopsy (TBFB) samples. The TBFB samples were collected from 80 patients (EHBDC, 68 patients; benign, 12 patients), retrospectively. When using cytoplasmic-positive staining for IMP3 as a marker of malignancy, the sensitivity and specificity reached 79.4 and 91.7 %, respectively. The sensitivity, specificity and accuracy achieved 89.7, 91.7 and 90.0 %, respectively, when using positive staining for IMP3 and/or positive histology as a maker of malignancy. While univariate (P = 0.033) and multivariate (P = 0.039) analysis revealed that S100P-positive EHBDC patients showed significantly shorter survival. The results of this study suggest that immunohistochemical staining for IMP3 is useful in the diagnosis of EHBDC and that of S100P is useful as a prognostic marker for EHBDC. Source

Sindhikara D.J.,Nagoya University | Emerson D.J.,University of Florida | Roitberg A.E.,University of Florida
Journal of Chemical Theory and Computation | Year: 2010

Previous work by us showed that in replica exchange molecular dynamics, exchanges should be attempted extremely often, providing gains in efficiency and no undesired effects. Since that time some questions have been raised about the extendability of these claims to the general case. In this work, we answer this question in two ways. First, we perform a study measuring the effect of exchange attempt frequency in explicit solvent simulations including thousands of atoms. This shows, consistent with the previous assertion, that high exchange attempt frequency allows an optimal rate of exploration of configurational space. Second, we present an explanation of many theoretical and technical pitfalls when implementing replica exchange that cause "improper" exchanges resulting in erroneous data, exacerbated by high exchange attempt frequency. © 2010 American Chemical Society. Source

Sawa M.,Nagoya University
IEEE Transactions on Information Theory | Year: 2010

An optical orthogonal signature pattern code (OOSPC) finds application in transmitting 2-D images through multicore fiber in code-division multiple-access (CDMA) communication systems. Observing a one-to-one correspondence between an OOSPC and a certain combinatorial subject, called a packing design, we present a construction of optimal OOSPCs with weight 4 and maximum collision parameter 2, which generalizes a well-known Köhler construction of optimal optical orthogonal codes (OOC) with weight 4 and maximum collision parameter 2. Using this new construction enables one to obtain infinitely many optimal OOSPCs, whose existence was previously unknown. We prove that for a multiple n of 4, there exists no optimal OOSPC of size 6 times; n with weight 4 and maximum collision parameter 2, together with a report which shows a gap between optimal OOCs and optimal OOSPCs when 6 and n are not coprime. We also present a recursive construction of OOSPCs which are asymptotically optimal with respect to the Johnson bound. As a by-product, we obtain an asymptotically optimal (m,n,4,2)-OOSPC for all positive integers m and n. © 2010 IEEE. Source

Okuzumi S.,Nagoya University | Hirose S.,Japan Agency for Marin Earth Science and Technology
Astrophysical Journal Letters | Year: 2012

Turbulence driven by magnetorotational instability (MRI) affects planetesimal formation by inducing diffusion and collisional fragmentation of dust particles. We examine conditions preferred for planetesimal formation in MRI-inactive "dead zones" using an analytic dead-zone model based on our recent resistive MHD simulations. We argue that successful planetesimal formation requires not only a sufficiently large dead zone (which can be produced by tiny dust grains) but also a sufficiently small net vertical magnetic flux (NVF). Although often ignored, the latter condition is indeed important since the NVF strength determines the saturation level of turbulence in MRI-active layers. We show that direct collisional formation of icy planetesimal across the fragmentation barrier is possible when the NVF strength is lower than 10 mG (for the minimum-mass solar nebula model). Formation of rocky planetesimals via the secular gravitational instability is also possible within a similar range of the NVF strength. Our results indicate that the fate of planet formation largely depends on how the NVF is radially transported in the initial disk formation and subsequent disk accretion processes. © 2012. The American Astronomical Society. All rights reserved.. Source

Ogihara M.,Nagoya University | Ida S.,Tokyo Institute of Technology
Astrophysical Journal | Year: 2012

As the number of discovered extrasolar planets has been increasing, diversity of planetary systems requires studies of new formation scenarios. It is important to study satellite formation in circumplanetary disks, which is often viewed as analogous to formation of rocky planets in protoplanetary disks. We investigated satellite formation from satellitesimals around giant planets through N-body simulations that include gravitational interactions with a circumplanetary gas disk. Our main aim is to reproduce the observable properties of the Galilean satellites around Jupiter through numerical simulations, as previous N-body simulations have not explained the origin of the resonant configuration. We performed accretion simulations based on the work of Sasaki et al., in which an inner cavity is added to the model of Canup & Ward. We found that several satellites are formed and captured in mutual mean motion resonances outside the disk inner edge and are stable after rapid disk gas dissipation, which explains the characteristics of the Galilean satellites. In addition, owing to the existence of the disk edge, a radial compositional gradient of the Galilean satellites can also be reproduced. An additional objective of this study is to discuss orbital properties of formed satellites for a wide range of conditions by considering large uncertainties in model parameters. Through numerical experiments and semianalytical arguments, we determined that if the inner edge of a disk is introduced, a Galilean-like configuration in which several satellites are captured into a 2:1 resonance outside the disk inner cavity is almost universal. In fact, such a configuration is produced even for a massive disk ≳ 104 g cm-2 and rapid type I migration. This result implies the inevitability of a Galilean satellite formation in addition to providing theoretical predictions for extrasolar satellites. That is, we can predict a substantial number of exomoon systems in the 2:1 mean motion resonance close to their host planets awaiting discovery. © 2012. The American Astronomical Society. All rights reserved. Source

Toyokuni S.,Nagoya University
Frontiers in Pharmacology | Year: 2014

Iron is the most abundant metal in the human body and mainly works as a cofactor for proteins such as hemoglobin and various enzymes. No independent life forms on earth can survive without iron. However, excess iron is intimately associated with carcinogenesis by increasing oxidative stress via its catalytic activity to generate hydroxyl radicals. Biomolecules with redox-active sulfhydryl function(s) (thiol compounds) are necessary for the maintenance of mildly reductive cellular environments to counteract oxidative stress, and for the execution of redox reactions for metabolism and detoxification. Involvement of glutathione S-transferase and thioredoxin has long attracted the attention of cancer researchers. Here, I update recent findings on the involvement of iron and thiol compounds during carcinogenesis and in cancer cells. It is now recognized that the cystine/glutamate transporter (antiporter) is intimately associated with ferroptosis, an iron-dependent, non-apoptotic form of cell death, observed in cancer cells, and also with cancer stem cells; the former with transporter blockage but the latter with its stabilization. Excess iron in the presence of oxygen appears the most common known mutagen. Ironically, the persistent activation of antioxidant systems via genetic alterations in Nrf2 and Keap1 also contributes to carcinogenesis. Therefore, it is difficult to conclude the role of iron and thiol compounds as friends or foes, which depends on the quantity/distribution and induction/flexibility, respectively. Avoiding further mutation would be the most helpful strategy for cancer prevention, and myriad of efforts are being made to sort out the weaknesses of cancer cells. © 2014 Toyokuni. Source

Nojiri S.,Nagoya University
Modern Physics Letters A | Year: 2010

We review how we can construct the gravity models which reproduces the arbitrary development of the universe. We consider the reconstruction in the Einstein gravity coupled with generalized perfect fluid, scalar-Einstein gravity, scalar-Einstein-Gauss-Bonnet gravity, Einstein-F(G)-gravity, and F(R)-gravity. Very explicit formulas are given to reconstruct the models, which could be used when we find the detailed data of the development of the universe by future observations. Especially we find the formulas using e-foldings, which has a direct relation with observed redshift. As long as we observe the time development of the Hubble rate H, there exists a variety of models describing the arbitrary development of universe. © 2010 World Scientific Publishing Company. Source

Ormel C.W.,University of California at Berkeley | Okuzumi S.,Tokyo Institute of Technology | Okuzumi S.,Nagoya University
Astrophysical Journal | Year: 2013

A critical phase in the standard model for planet formation is the runaway growth (RG) phase. During RG bodies in the 0.1-100 km size range (planetesimals) quickly produce a number of much larger seeds. The RG phase is essential for planet formation as the emergent planetary embryos can accrete the leftover planetesimals at large gravitational focusing factors. However, torques resulting from turbulence-induced density fluctuations may violate the criterion for the onset of RG, which is that the magnitude of the planetesimals' random (eccentric) motions is less than their escape velocity. This condition represents a more stringent constraint than the condition that planetesimals survive their mutual collisions. To investigate the effects of magneto-rotational instability turbulence on the viability of the RG scenario, we apply our semi-analytical recipes of Paper I, which we augment by a coagulation/fragmentation model for the dust component. We find that the surface-area-equivalent abundance of 0.1 μm particles is reduced by factors 102-103, which tends to render the dust irrelevant to the turbulence. We express the turbulent activity in the midplane regions in terms of a size srun above which planetesimals will experience RG. We find that srun is mainly determined by the strength of the vertical net field that threads the disks and the disk radius. At disk radii beyond 5 AU, srun becomes larger than ∼100 km and the collision times among these bodies longer than the duration of the nebula phase. Our findings imply that the classical, planetesimal-dominated model for planet formation is not viable in the outer regions of a turbulent disk. © 2013. The American Astronomical Society. All rights reserved. Source

Okuzumi S.,Tokyo Institute of Technology | Okuzumi S.,Nagoya University | Ormel C.W.,University of California at Berkeley
Astrophysical Journal | Year: 2013

Turbulence in protoplanetary disks affects planet formation in many ways. While small dust particles are mainly affected by the aerodynamical coupling with turbulent gas velocity fields, planetesimals and larger bodies are more affected by gravitational interaction with gas density fluctuations. For the latter process, a number of numerical simulations have been performed in recent years, but a fully parameter-independent understanding has not been yet established. In this study, we present simple scaling relations for the planetesimal stirring rate in turbulence driven by magnetorotational instability (MRI), taking into account the stabilization of MRI due to ohmic resistivity. We begin with order-of-magnitude estimates of the turbulence-induced gravitational force acting on solid bodies and associated diffusion coefficients for their orbital elements. We then test the predicted scaling relations using the results of recent ohmic-resistive MHD simulations by Gressel et al. We find that these relations successfully explain the simulation results if we properly fix order-of-unity uncertainties within the estimates. We also update the saturation predictor for the density fluctuation amplitude in MRI-driven turbulence originally proposed by Okuzumi & Hirose. Combination of the scaling relations and saturation predictor allows us to know how the turbulent stirring rate of planetesimals depends on disk parameters such as the gas column density, distance from the central star, vertical resistivity distribution, and net vertical magnetic flux. In Paper II, we apply our recipe to planetesimal accretion to discuss its viability in turbulent disks. © 2013. The American Astronomical Society. All rights reserved. Source

Takahashi R.,Hirosaki University | Sato M.,Nagoya University | Nishimichi T.,University of Tokyo | Taruya A.,University of Tokyo | Oguri M.,University of Tokyo
Astrophysical Journal | Year: 2012

Based on a suite of state-of-the-art high-resolution N-body simulations, we revisit the so-called halofit model as an accurate fitting formula for the nonlinear matter power spectrum. While the halofit model has frequently been used as a standard cosmological tool to predict the nonlinear matter power spectrum in a universe dominated by cold dark matter, its precision has been limited by the low resolution of N-body simulations used to determine the fitting parameters, suggesting the necessity of an improved fitting formula at small scales for future cosmological studies. We run high-resolution N-body simulations for 16 cosmological models around the Wilkinson Microwave Anisotropy Probe best-fit cosmological parameters (one-, three-, five-, and seven-year results), including dark energy models with a constant equation of state. The simulation results are used to re-calibrate the fitting parameters of the halofit model so as to reproduce small-scale power spectra of the N-body simulations, while keeping the precision at large scales. The revised fitting formula provides an accurate prediction of the nonlinear matter power spectrum in a wide range of wavenumbers (k ≤ 30 h Mpc-1) at redshifts 0 ≤ z ≤ 10, with 5% precision for k ≤ 1 h Mpc-1 at 0 ≤ z ≤ 10 and 10% for 1 ≤ k ≤ 10 h Mpc-1 at 0 ≤ z ≤ 3. We discuss the impact of the improved halofit model on weak-lensing power spectra and correlation functions, and show that the improved model better reproduces ray-tracing simulation results. © 2012. The American Astronomical Society. All rights reserved.. Source

Takeuchi H.,Nagoya University
Clinical and Experimental Neuroimmunology | Year: 2010

Microgliosis (accumulation of activated microglia) around degenerative neurons is a common pathological feature of various neurological disorders. Glutamate released by activated microglia induces excito-neurotoxicity and most likely contributes to neurodegeneration in numerous neurological diseases including ischemia, inflammation, epilepsy and neurodegenerative diseases. Although both blockade of glutamate receptors and inhibition of microglial activation are the therapeutic candidates for activated microglia-mediated neurodegenerative diseases, clinical trials have been failed because of adverse effects. In the present review, the neurotoxic factors from activated microglia are examined, and how these factors disturb neuronal functions is discussed. The efforts to suppress neurotoxic mechanisms by microglia are also introduced. © 2010 Japanese Society for Neuroimmunology. Source

The phase diagram (critical temperature and compensation temperature) and the total magnetizations in a nanoscaled transverse Ising thin film with thickness L and a negative interlayer coupling at the surfaces are investigated by the use of both the effective-field theory with correlations and the mean-field theory. Particular emphasis is given to the effects of the surface and its dilution on them. We have found that, for appropriate values of the system parameters, compensation point (or points) may be obtained in the present system with L=5 (or L=10). © 2012 Copyright Taylor and Francis Group, LLC. Source

Ogawa-Ohnishi M.,Japan National Institute for Basic Biology | Matsushita W.,Nagoya University | Matsubayashi Y.,Japan National Institute for Basic Biology
Nature Chemical Biology | Year: 2013

Hydroxyproline (Hyp) O-arabinosylation is a post-translational modification that is prominent in extracellular glycoproteins in plants. Hyp O-arabinosylation is generally found in these glycoproteins in the form of linear oligoarabinoside chains and has a key role in their function by contributing to conformational stability. However, Hyp O-arabinosyltransferase (HPAT), a key enzyme that catalyzes the transfer of the L-arabinose to the hydroxyl group of Hyp residues, has remained undiscovered. Here, we purified and identified Arabidopsis HPAT as a Golgi-localized transmembrane protein that is structurally similar to the glycosyltransferase GT8 family. Loss-of-function mutations in HPAT-encoding genes cause pleiotropic phenotypes that include enhanced hypocotyl elongation, defects in cell wall thickening, early flowering, early senescence and impaired pollen tube growth. Our results indicate essential roles of Hyp O-arabinosylation in both vegetative and reproductive growth in plants. © 2013 Nature America, Inc. All rights reserved. Source

Kaneyoshi T.,Nagoya University
Phase Transitions | Year: 2012

The phase diagram and magnetizations of a cylindrical nanotube described by the transverse Ising model are investigated by the use of the effective field theory with correlations. Some comparisons between the nanotube and the nanowire have been given for the phase diagrams. In particular, the temperature dependences of longitudinal magnetization in the system with a negative shell-core interaction are investigated. Some characteristic phenomena (new types in ferrimagnetism) which have not been observed in the nanowire as well as similar phenomena are found in the thermal variations, depending on the ratio of the physical parameters in the surface shell and the core. The possibilities of two compensation points and a field induced compensation point in the nanotube are also discussed. © 2012 Taylor & Francis Group, LLC. Source

Toyokuni S.,Nagoya University
Journal of Clinical Biochemistry and Nutrition | Year: 2011

Persistent oxidative stress has been associated with carcinogenesis. Iron overload is considered one such condition that causes oxidative stress. Epidemiological studies support a close link between iron overload and carcinogenesis. Reportedly, regular semiannual phlebotomies reduced cancer risk in an otherwise normal population. More specifically, genetic hemochromatosis, chronic viral hepatitis, ovarian endometriosis and asbestosis induce iron overload, which can lead to hepatocellular carcinoma, ovarian carcinoma or mesothelioma in humans. Through a combination of animal experiments and microarray analyses, homozygous deletion of CDKN2A/2B has been recognized as one of the major target genes involved in iron overload-induced carcinogenesis. CDKN2A/2B are the second most frequently inactivated tumor suppressing genes in human cancers. Currently, when infection is becoming sufficiently controlled worldwide, iron regulation may be the next target for human longevity. ©2011 JCBN. Source

Machida M.N.,Japan National Astronomical Observatory | Inutsuka S.-I.,Nagoya University | Matsumoto T.,Hosei University
Astrophysical Journal | Year: 2010

The formation and evolution of the circumstellar disk in unmagnetized molecular clouds is investigated using three-dimensional hydrodynamic simulations from the prestellar core until the end of the main accretion phase. In collapsing cloud cores, the first (adiabatic) core with a size of ≳3 AU forms prior to the formation of the protostar. At its formation, the first core has a thick disk-like structure and is mainly supported by the thermal pressure. After the protostar formation, it decreases the thickness gradually and becomes supported by the centrifugal force. We found that the first core is a precursor of the circumstellar disk with a size of ≥3 AU. This means that unmagnetized protoplanetary disk smaller than <3 AU does not exist. Reflecting the thermodynamics of the collapsing gas, at the protostar formation epoch, the first core (or the circumstellar disk) has a mass of ∼0.005-0.1 M ⊙, while the protostar has a mass of ∼103 M ⊙. Thus, just after the protostar formation, the circumstellar disk is about 10-100 times more massive than the protostar. In the main accretion phase that lasts for ∼ 105 yr, the circumstellar disk mass initially tends to dominate the protostellar mass. Such a massive disk is unstable to gravitational instability and tends to show fragmentation. Our calculations indicate that the low-mass companions may form in the circumstellar disk in the main accretion phase. In addition, the mass accretion rate onto the protostar shows a strong time variability that is caused by the torque from the low-mass companions and/or the spiral arms in the circumstellar disk. Such variability provides an important signature for detecting the substellar mass companion in the circumstellar disk around very young protostars. © 2010. The American Astronomical Society. Source

Hikage C.,Nagoya University
Monthly Notices of the Royal Astronomical Society: Letters | Year: 2014

We propose a new method of measuring halo occupation distribution (HOD) together with cosmic growth rate using multipole components of galaxy power spectrum Pl(k). The non-linear redshift-space distortion due to the random motion of satellite galaxies, i.e. Fingers-of-God, generates high-l multipole anisotropy in galaxy clustering, such as the hexadecapole (l = 4) and tetra-hexadecapole (l = 6), which are sensitive to the fraction and the velocity dispersion of satellite galaxies. Using simulated samples following the HOD of luminous red galaxies, we find that the input HOD parameters are successfully reproduced from Pl(k), and that high-l multipole information help to break the degeneracy among HOD parameters. We also show that the measurements of the cosmic growth rate as well as the satellite fraction and velocity dispersions are significantly improved by adding the small-scale information of high-l multipoles. © 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

The effects of dung form and condition and of dung beetles on the emergence of seedlings from herbaceous seeds in sika deer dung were examined in a temperate grassland ecosystem dominated by Zoysia japonica and Hydrocotyle maritima. I conducted field experiments to compare seedling emergence between dung exposed to dung beetles and intact dung using both dung pellets and pats during a typical rainy month (June) and the hottest, drier month (August), when large numbers of seeds of the dominant species were present in the dung. The exposed dung was immediately attacked and broken up by dung beetles, whereas dung protected from the beetles remained intact. In June, at least 12 herbaceous species, including Z. japonica, H. maritima, Mazus pumilus, and Plantago asiatica, emerged from the dung, versus at least six species in August. Decomposition rates of the pellets in June and decomposition scores of the pats in June and August were positively correlated with the number of emerging seedlings, suggesting that the acceleration of decomposition by dung beetles can positively affect seed germination. In this system of interactions among sika deer, herbaceous plants, and dung beetles, sika deer dung prevented seeds from germinating, and beetles had an indirect positive effect on seedling emergence by accelerating decomposition of the dung, although the extent of the effect may depend on the dung type, plant species, and environmental factors. © 2011 The Ecological Society of Japan. Source

The plasma membrane H (+) -ATPase provides the driving force for solute transport via an electrochemical gradient of H (+) across the plasma membrane, and regulates pH homeostasis and membrane potential in plant cells. However, the plasma membrane H (+) -ATPase in non-vascular plant bryophyte is largely unknown. Here, we show that the moss Physcomitrella patens, which is known as a model bryophyte, expresses both the penultimate Thr-containing H (+) -ATPase (pT H (+) -ATPase) and non-pT H (+) -ATPase as in the green algae, and that pT H (+) -ATPase is regulated by phosphorylation of its penultimate Thr. A search in the P. patens genome database revealed seven H (+) -ATPase genes, designated PpHA (Physcomitrella patens H (+) -ATPase). Six isoforms are the pT H (+) -ATPase; a remaining isoform is non-pT H (+) -ATPase. An apparent 95-kD protein was recognized by anti-H (+) -ATPase antibodies against an isoform of Arabidopsis thaliana and was phosphorylated on the penultimate Thr in response to a fungal toxin fusicoccin and light in protonemata, indicating that the 95-kD protein contains pT H (+) -ATPase. Furthermore, we could not detect the pT H (+) -ATPase in the charophyte alga Chara braunii, which is the closest relative of the land plants, by immunological methods. These results strongly suggest the pT H (+) -ATPase most likely appeared for the first time in bryophyte. Source

One of the ultimate goals of the study on mechanosensitive (MS) channels is to understand the biophysical mechanisms of how the MS channel protein senses forces and how the sensed force induces channel gating. The bacterial MS channel MscL is an ideal subject to reach this goal owing to its resolved 3D protein structure in the closed state on the atomic scale and large amounts of electrophysiological data on its gating kinetics. However, the structural basis of the dynamic process from the closed to open states in MscL is not fully understood. In this study, we performed molecular dynamics (MD) simulations on the initial process of MscL opening in response to a tension increase in the lipid bilayer. To identify the tension-sensing site(s) in the channel protein, we calculated interaction energy between membrane lipids and candidate amino acids (AAs) facing the lipids. We found that Phe78 has a conspicuous interaction with the lipids, suggesting that Phe78 is the primary tension sensor of MscL. Increased membrane tension by membrane stretch dragged radially the inner (TM1) and outer (TM2) helices of MscL at Phe78, and the force was transmitted to the pentagon-shaped gate that is formed by the crossing of the neighboring TM1 helices in the inner leaflet of the bilayer. The radial dragging force induced radial sliding of the crossing portions, leading to a gate expansion. Calculated energy for this expansion is comparable to an experimentally estimated energy difference between the closed and the first subconductance state, suggesting that our model simulates the initial step toward the full opening of MscL. The model also successfully mimicked the behaviors of a gain of function mutant (G22N) and a loss of function mutant (F78N), strongly supporting that our MD model did simulate some essential biophysical aspects of the mechano-gating in MscL. Source

Ohsawa Y.,Nagoya University
Physics Reports | Year: 2014

This paper describes the theory and particle simulations of ultrarelativistic particle acceleration caused by shock waves in a collisionless magnetized plasma.Since knowledge of field strengths and structures is necessary for the analysis of particle motions, theories of magnetosonic waves are reviewed first: (1) linear and nonlinear magnetosonic waves in a single-ion-species plasma, (2) those in a two-ion-species plasma, (3) those in an electron-positron-ion (EPI) plasma, and (4) the electric field parallel to the magnetic field, E∥. The first topic contains a general introduction to the magnetosonic wave. The second and third topics are concerned with three-component plasmas, in which the magnetosonic wave is split into two modes; the plasma behavior can thus be considerably different from that in a single-ion-species plasma. The fourth topic is the parallel electric field E∥ in a nonlinear magnetosonic wave. It is shown that E∥ can be strong even in low frequency, magnetohydrodynamic phenomena.Next, nonstochastic particle acceleration caused by the intense electric and magnetic fields formed in a shock wave is studied with theory and with fully kinetic, fully relativistic, electromagnetic, particle simulations. The subjects include (1) electron trapping and acceleration, (2) energization of thermal and relativistic ions, (3) heavy-ion acceleration and resultant damping of nonlinear pulses in a multi-ion-species plasma, and (4) positron acceleration due to E∥ in the shock transition region in an EPI plasma. In addition to these processes near a shock front, (5) the evolution of large-amplitude Alfvénwaves generated behind a shock front and acceleration of electrons in the Alfvénwave region are examined.Simulations demonstrate particle acceleration caused by these nonlinear magnetohydrodynamic waves to ultrarelativistic energies much higher than those of solar energetic particles. The acceleration theory based on the investigation of nonlinear waves quantitatively accounts for these simulation results. © 2013 Elsevier B.V. Source

Muraoka K.,Chubu University | Kono A.,Nagoya University
Journal of Physics D: Applied Physics | Year: 2011

In recent years, low-temperature discharge plasmas with electron temperatures around a few eV have been actively studied and used for fundamental discharge physics research and industrial process applications. Here the electron density and temperature (and sometimes also the electron energy distribution function) are the most fundamental parameters that dictate the fates of these discharge plasmas and this information is of utmost importance. Laser Thomson scattering, which was developed for high-temperature plasmas in the early 1960s, has gained widespread use in the low-temperature plasma community since the late 1970s and has now matured as an established method of plasma diagnostics. Scattering diagnostic techniques for high-temperature plasmas have had to be modified to accommodate particular situations and constraints, such as laser perturbation of plasmas, low electron densities and the presence of material surfaces near to the plasmas. In this review, starting from a basic description of the technique, we outline some of the most salient results, which would not have been obtained without it, in discharges ranging from high-pressure to low-pressure gases, and near to material surfaces. Also, the signal-to-noise ratio and future potential of the method are discussed. © 2011 IOP Publishing Ltd. Source

Kurokawa H.,Nagoya University | Nakamoto T.,Tokyo Institute of Technology
Astrophysical Journal | Year: 2014

During their evolution, short-period exoplanets may lose envelope mass through atmospheric escape owing to intense X-ray and extreme ultraviolet (XUV) radiation from their host stars. Roche-lobe overflow induced by orbital evolution or intense atmospheric escape can also contribute to mass loss. To study the effects of mass loss on inner planet populations, we calculate the evolution of hot Jupiters considering mass loss of their envelopes and thermal contraction. Mass loss is assumed to occur through XUV-driven atmospheric escape and the following Roche-lobe overflow. The runaway effect of mass loss results in a dichotomy of populations: hot Jupiters that retain their envelopes and super Earths whose envelopes are completely lost. Evolution primarily depends on the core masses of planets and only slightly on migration history. In hot Jupiters with small cores (≃ 10 Earth masses), runaway atmospheric escape followed by Roche-lobe overflow may create sub-Jupiter deserts, as observed in both mass and radius distributions of planetary populations. Comparing our results with formation scenarios and observed exoplanets populations, we propose that populations of closely orbiting exoplanets are formed by capturing planets at/inside the inner edges of protoplanetary disks and subsequent evaporation of sub-Jupiters. © 2014. The American Astronomical Society. All rights reserved.. Source

Asgari-Targhi M.,Harvard - Smithsonian Center for Astrophysics | Van Ballegooijen A.A.,Harvard - Smithsonian Center for Astrophysics | Imada S.,Nagoya University
Astrophysical Journal | Year: 2014

The observed non-thermal widths of coronal emission lines could be due to Alfvén wave turbulence. To test this idea, we examine and analyze the dynamics of an active region observed on 2012 September 7. We use spectral line profiles of Fe XII, Fe XIII, Fe XV, and Fe XVI obtained by the Extreme-ultraviolet Imaging Spectrometer on the it Hinode spacecraft. The observations show non-thermal velocities, Doppler outflows, and intensities for loops in this active region. The observed non-thermal velocities are compared with predictions from models for Alfvén wave turbulence in the observed coronal loops. This modeling takes into account the relationship between the width of the coronal emission lines and the orientation of the coronal loops with respect to the line-of-sight direction. We find that in order to produce the observed line widths we need to introduce a random parallel-flow component in addition to the perpendicular velocity due to Alfvén waves. The observed widths are consistent with photospheric footpoint velocities in the range 0.3-1.5 km s-1. We conclude that the Alfvén wave turbulence model is a strong candidate for explaining how the observed loops are heated. © 2014. The American Astronomical Society. All rights reserved. Source

Kobayashi N.,Nagoya University | Fan L.-S.,Ohio State University
Biomass and Bioenergy | Year: 2011

This paper provides a perspective on the biomass direct chemical looping (BDCL) scheme which directly converts biomass into hydrogen and/or electricity with CO2 capture. The discussion involves the preliminary design, potential challenges, and feasibility assessments in the BDCL process. Description of the BDCL process and the characteristics of biomass are provided in order to discuss potential advantage and disadvantage that may occur in this system. The feasibility of employing the BDCL process based on preliminary studies relative to competing biomass technologies and conventional fossil fuel conversion schemes is also discussed based on the perspective of energy conversion efficiencies, and economic analysis. Biomass has proven to be less efficient and more cost intensive compared to the current fossil fuel processes, due to its relatively low energy density, high moisture content and distributed-resource. However, the BDCL process has the potential to compete against conventional energy generation systems via its high conversion efficiency. A preliminary economic analysis demonstrates that BDCL system integrated with CCS to receive carbon credit is capable of producing electricity at a competitive price to the current fossil fuel processes. © 2010 Elsevier Ltd. Source

Naoe T.,Nagoya University
International Journal of Hematology | Year: 2012

Acute myeloid leukemia (AML) is predominantly a disease of older adults, with a median age at diagnosis of over 65 years. AML in older adults differs biologically and clinically from that in younger ones, and is characterized by stronger intrinsic resistance and lower tolerance to chemotherapy. The effects of age on both patient- and disease-related factors result in a higher incidence of early death during chemotherapy, a lower rate of complete remission, and a reduced chance of long-term survival. Treatment options for older adults with AML include intensive chemotherapy, less-intensive chemotherapy, best supportive care, or enrolment in clinical trials. Given the heterogeneous nature of AML in older adults, therapeutic decisions need to be individualized after systematic assessment of disease biology and patient characteristics. Regardless of treatment, however, outcomes for older AML patients remain in general unsatisfactory. In contrast with the progress made for younger adults, the treatment of AML in older adults has not improved significantly in recent decades. Development of less toxic and more targeted agents may well provide treatment alternatives for a majority of these patients. The overall dismal outcome with currently available treatment approaches has encouraged older AML patients to participate in prospective clinical trials. © 2012 The Japanese Society of Hematology. Source

Kimura Y.,Nagoya University | Herring J.R.,U.S. National Center for Atmospheric Research
Journal of Fluid Mechanics | Year: 2012

We investigate homogeneous incompressible turbulence subjected to a range of degrees of stratification. Our basic method is pseudospectral direct numerical simulations at a resolution of 1024 3. Such resolution is sufficient to reveal inertial power-law ranges for suitably comprised horizontal and vertical spectra, which are designated as the wave and vortex mode (the Craya-Herring representation). We study mainly turbulence that is produced from randomly large-scale forcing via an Ornstein-Uhlenbeck process applied isotropically to the horizontal velocity field. In general, both the wave and vortex spectra are consistent with a Kolmogorov-like k- 5/3 range at sufficiently large k. At large scales, and for sufficiently strong stratification, the wave spectrum is a steeper k -2, while that for the vortex component is consistent with k -3. Here k is the horizontally gathered wavenumber. In contrast to the horizontal wavenumber spectra, the vertical wavenumber spectra show very different features. For those spectra, a clear k z -3 dependence for small scales is observed while the large scales show rather flat spectra. By modelling the horizontal layering of vorticity, we attempt to explain the flat spectra. These spectra are linked to two-point structure functions of the velocity correlations in the horizontal and vertical directions. We can observe the power-law transition also in certain of the two-point structure functions. © 2012 Cambridge University Press. Source

Ohta M.,Nagoya University
Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases | Year: 2010

Helicobacter pylori infection is implicated in the pathogenesis of extradigestive diseases such as acne rosacea and idiopathic chronic urticaria and autoimmune diseases such as autoimmune gastric atrophy, rheumatoid arthritis, anti phospholipid antibody syndrome, autoimmune thyroiditis, Sjoegren syndrome, Henoch-Schoenlein purpura, and Type B insulin resistance syndrome. H. pylori eradication ameliorated the condition in some, but not all, of those with these autoimmune diseases. Recent studies primarily in Italy and Japan found that H. pylori eradication in those infected with chronic immune thrombocytopenic purpura (ITP) results in a persistent platelet count increase in over half of those treated, suggesting that although pathogenetic mechanisms underlying the relationship between H. pylori infection and autoimmune disease remain unclear, yet-unknown immunological events induced by H. pylori infection almost certainly occur in the development of autoimmune response. A majority of isolated H. pylori strains express human Lewis (Le(x) and/or Le(y) determinants and in some strains, Le(a), Le(b), sialyl-Le(x)), and H determinants in the O-chain of the surface lipopolysaccharide. Previous studies showed that this molecular mimicry helps the bacterium evade host responses while evoking autoantibody responses to Le antigens. The anti-Le(y) autoantibody is also reported to promote H. pylori adhesion to gastric epithelial cells, leading to development of gastric atrophy. Moreover, one can hypothesize that anti-Le autoreactive antibodies induced by H. pylori infection are involved in the development of autoimmune diseases, although no clinical studies showing that anti-Le immune responses are involved in the etiology of these autoimmune diseases have been conducted. Proving this hypothesis would require quantitative and qualitative analysis of autoantibodies and T cell functions to Le antigens. High frequent phase variation of Le structures in the O-polysaccharide of H. pylori may influence the immune response of patients to Le antigens. Source

Iguchi S.,Japan National Astronomical Observatory | Okuda T.,Nagoya University | Sudou H.,Gifu University
Astrophysical Journal Letters | Year: 2010

Recent observational results provide possible evidence that binary black holes (BBHs) exist in the center of giant galaxies and may merge to form a supermassive black hole in the process of their evolution. We first detected a periodic flux variation on a cycle of 93 ±1 days from the 3 mm monitor observations of a giant elliptical galaxy 3C 66B for which an orbital motion with a period of 1.05 ±0.03 yr had been already observed. The detected signal period being shorter than the orbital period can be explained by taking into consideration the Doppler-shifted modulation due to the orbital motion of a BBH. Assuming that the BBH has a circular orbit and that the jet axis is parallel to the binary angular momentum, our observational results demonstrate the presence of a very close BBH that has a binary orbit with an orbital period of 1.05 ±0.03 yr, an orbital radius of (3.9 ±1.0) ×10 -3 pc, an orbital separation of (6.1-0.9 +1.0) × 10-3 pc, a larger black hole mass of (1.2 -0.2 +0.5) × 109 M⊙, and a smaller black hole mass of (7.0-6.4 +4.7) × 10 8 M⊙. The BBH decay time of (5.1 -2.5 +60.5 ) × 102 yr provides evidence for the occurrence of black hole mergers. This Letter will demonstrate the interesting possibility of black hole collisions to form a supermassive black hole in the process of evolution, one of the most spectacular natural phenomena in the universe. © 2010 The American Astronomical Society. All rights reserved. Source

Eisenberger P.,Queens University | Bestvater B.P.,Queens University | Keske E.C.,Queens University | Crudden C.M.,Queens University | Crudden C.M.,Nagoya University
Angewandte Chemie - International Edition | Year: 2015

1,2,3-Triazolylidene-based mesoionic carbene boranes have been synthesized in a convenient one-pot protocol from the corresponding 1,2,3-triazolium salts, base, and borane. Borenium ions are obtained by hydride abstraction and serve as catalysts in mild hydrogenation reactions of imines and unsaturated N-heterocycles at ambient pressure and temperature. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. Source

Circadian clocks enable organisms to define subjective time, that is, to anticipate diurnal day and night cycles. Endogenous circadian rhythms regulate many aspects of an organism's physiological and morphological growth and development. These daily oscillations are synchronized to the environment by external cues such as light and temperature, resulting in enhanced fitness and growth vigor in plants. Recent findings concerning biochemical properties of central oscillators in Arabidopsis thaliana have advanced our understanding of circadian clock function. Central oscillators are composed of three classes of transcriptional repressors. The interactions among them include a repressilator structure. Output from the circadian clock is transduced through regulating transcription of downstream genes directly by the oscillator components. The essential role of the output pathway in the circadian system is to make different elementary steps responsible for daily cellular processes exert maximum effects at specific times of the day. Recently, significant progress was made in defining the mechanisms by which plant growth on a day-to-day basis is activated at specific times of the day in a manner dependent on photoperiod and temperature conditions. Plant growth is controlled by the clock through interactions with light and phytohormone signaling. This review focuses on the node that connects clock output to light and phytohormone signaling that coordinates plant growth with rhythmic changes in the environment. Source

Yokoshima S.,Nagoya University
Chemical and Pharmaceutical Bulletin | Year: 2013

Herein we present our unique strategies to synthesize natural products. To prepare mersicarpine, an atypical indole alkaloid, our procedure features an Eschenmoser-Tanabe fragmentation to synthesize an alkyne unit, a combination of a Sonogashira coupling and a gold(III) catalyzed cyclization to construct the indole skeleton, and a one-pot process to arrange the cyclic imine and the hemiaminal moieties. Additionally, we synthesized a frog poison, histrionicotoxin, via a chirality transfer from an allenylsilane to prepare a pseudosymmetrical dienyne, dienyne metathesis to produce an optically active bicyclo [5.4.0] system, and an asymmetric propargylation. To synthesize lyconadin A, a Lycopodium alkaloid, a combination of an aza- Prins reaction and electrocyclic ring opening constructed the highly fused tetracyclic compound. The synthesis of isoschizogamine features a facile construction of the carbon framework through a Wagner-Meerwein rearrangement, a tandem metathesis, a stereoselective rhodium-mediated 1,4-addition of an arylboronic acid, and a ring-closing metathesis via a hemiaminal ether. © 2013 The Pharmaceutical Society of Japan. Source

Yamazaki M.,Nagoya University | Jalife J.,University of Michigan
Journal of Arrhythmia | Year: 2012

Atrial fibrillation (AF) is the most common arrhythmia in adults; it affects approximately 0.8 million patients in Japan alone. Yet despite many years of basic and clinical research, the exact mechanisms underlying the initiation and maintenance of AF remain poorly understood. In this review article, we summarize recent high-resolution optical mapping studies in isolated sheep hearts, which have provided new insights into the dynamics and mechanisms of AF. We focus on 3 models of AF. First, we discuss results from experiments on AF induced by atrial stretch that revealed the presence of spatio-temporally organized waves emerging from the posterior wall of the left atrium. In the presence of adreno-cholinergic stimulation and stretch, AF was governed by evolving interactions between reentry and spontaneous focal discharges. Next, we outline the results obtained from a persistent AF model (average AF duration: 21.3 day) induced by intermittent rapid atrial pacing. By using simultaneous optical mapping of epicardial and endocardial activation patterns, we demonstrated that AF in this model was maintained by 3-dimensional scroll waves with I-shaped filaments anchored to junctions between thin and thick myocardium. Numerical simulation results predicted that wall thickness-dependent activation of stretch-activated channels and the filament tension dynamics were sufficient to explain the specific localization of the I-shaped filament. In a final set of studies discussed herein, we investigated AF in sheep with tachypacing-induced heart failure and found that microreentry in the left atria was a major mechanism of AF maintenance, although focal discharges at the pulmonary vein area also played a role. Large fibrotic patches in failing hearts may serve as potential anchoring sites for micro-reentry in this model. Thus, the 3 different experimental results in isolated sheep hearts presented here clearly suggest that self-sustained rotors do exist in the atria and that such rotors are in fact the high frequency sources that determine the complex patterns of activation that characterize AF. © 2012 Japanese Heart Rhythm Society. Published by Elsevier B.V. All rights reserved. Source

Takeoka Y.,Nagoya University
Polymer Journal | Year: 2015

This review addresses recent developments in structurally colored materials composed of submicrometer-sized fine particles, where the structural color is not angle-dependent. Recently, studies on colloidal crystals of submicrometer-sized fine particles for structurally colored materials applications have drawn great attention. Materials researchers have become aware that many living things exhibit bright structural colors that arise from amorphous arrays of particles, pores and fibers, and are now engaged in research related to this phenomenon. In particular, colloidal amorphous arrays composed of submicrometer-sized fine particles, which can display vivid structural color without angle dependence, have become a popular topic of study within recent years. In this paper, I review the possibility of using colloidal amorphous arrays as stimuli-responsive colored materials based on the properties of colloidal amorphous arrays that have been elucidated in recent experimental investigations. © 2015 The Society of Polymer Science, Japan (SPSJ) All rights reserved. Source

Matsumoto S.,Nagoya University
Letters in Mathematical Physics | Year: 2013

Consider a symmetric unitary random matrix V = (vij)1 ≤ i, j ≤ N from a circular orthogonal ensemble. In this paper, we study moments of a single entry vij. For a diagonal entry vii, we give the explicit values of the moments, and for an off-diagonal entry vij, we give leading and subleading terms in the asymptotic expansion with respect to a large matrix size N. Our technique is to apply the Weingarten calculus for a Haar-distributed unitary matrix. © 2012 Springer Science+Business Media Dordrecht. Source

Restless legs syndrome (RLS) is a common neurological disorder. Dementia with Lewy bodies (DLB) is the second most common form of neurodegenerative dementia after Alzheimer's disease. Both RLS and DLB can be effectively treated by dopaminergic medications, suggesting the role of dopamine dysfunction in the pathogenesis of both diseases. Here, I report on a Japanese woman with probable DLB and RLS who was treated with gabapentin enacarbil, a non-dopaminergic agent. Because a dopamine agonist, a first-line therapy for moderate to severe RLS, caused the occurrence of metamorphopsia, an alternative treatment of gabapentin enacarbil was used; this treatment improved the patient's RLS without worsening her psychiatric symptoms. An alternative treatment is desirable for DLB patients with RLS because they often experience intolerable side-effects with a dopamine agonist, especially visual hallucinations. Administering gabapentin enacarbil also improved the continuous leg pain that occurred in conjunction with the development of RLS. Although the neurobiological mechanism in the development of pain remains unclear, a range of non-dopaminergic structures likely mediated pain processing in DLB in the present case based on neuropharmacological results. This is the first report reporting the effects of gabapentin enacarbil for RLS and leg pain in a DLB patient with psychiatric symptoms. © 2014 Japanese Psychogeriatric Society. Source

Kaneyoshi T.,Nagoya University
Physica B: Condensed Matter | Year: 2014

The phase diagram, magnetization and Arrott plot of an ultrathin film with site or bond dilution at the surfaces are investigated by the use of the effective field theory with correlations (or the mean field theory for comparison). The system is consisted from the two Ising layers. A lot of characteristic phenomena can be found in them. In particular, the behaviors of them are completely different, depending on whether the site or bond dilution is performed at the surfaces. A lot of unexpected phenomena, such as a new type of frustration, have been obtained in the phase diagram and magnetization, when the strength of interlayer coupling between the two layers is changed. © 2013 Elsevier B.V. Source

Peters J.-M.,imp Inc | Nishiyama T.,imp Inc | Nishiyama T.,Nagoya University
Cold Spring Harbor Perspectives in Biology | Year: 2012

During S phase, not only does DNA have to be replicated, but also newly synthesized DNA molecules have to be connected with each other. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic spindle, and is thus an essential prerequisite for chromosome segregation. Cohesion is mediated by cohesin complexes that are thought to embrace sister chromatids as large rings. Cohesin binds to DNA dynamically before DNA replication and is converted into a stably DNA-bound form during replication. This conversion requires acetylation of cohesin, which in vertebrates leads to recruitment of sororin. Sororin antagonizes Wapl, a protein that is able to release cohesin from DNA, presumably by opening the cohesin ring. Inhibition ofWapl by sororin therefore "locks" cohesin rings on DNA and allows them to maintain cohesion for long periods of time in mammalian oocytes, possibly for months or even years. © 2012 Cold Spring Harbor Laboratory Press; all rights reserved. Source

Reactive oxygen species (ROS) have many functions in aerobic organisms. High levels of ROS can have a negative impact on plant cells leading to senescence and cell death. ROS accumulates in cells subjected to environmental stress and induces a cellular response to this external stimulus. To protect cells from the negative impacts of excess ROS, plants also possess a ROS detoxifying system to maintain normal ROS levels. The regulation of ROS levels is particularly important as ROS also functions as an important signal molecule and can regulate plant growth by modulating gene expression. Despite the functional importance of ROS signaling, little is known about the molecular mechanisms involved in the regulation of gene expression through ROS. Therefore, the present study investigated the effect of hydrogen peroxide (H2O2), a ROS compound, on cell cycle-related gene expression. Gene expression analyses coupled with microdissected sections of the developmental zone of Arabidopsis root tips revealed that H2O2 affects the expression of cell cycle-related genes. Additionally, ROS scavenging enzymes were found to play an important role in the root growth phenotype induced by H2O2. Specifically, root growth inhibition by H2O2 was diminished in transgenic Arabidopis overexpressing peroxidase but increased in a catalase2 (cat2) mutant. The strong root growth inhibition observed in the cat2 mutant upon H2O2 treatment indicated that CAT2 has an essential role in maintaining root meristem activity in the presence of oxidative stress. Overall, these results confirm that ROS function not only as stress-related compounds but that they also function as signaling molecules to regulate the progression of the cell cycle in root tips. © 2012 Elsevier Ireland Ltd. Source

Kaneyoshi T.,Nagoya University
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2014

The phase diagrams and magnetizations in a nanoscaled thin film with bond and site dilutions at the surfaces, described by the transverse Ising model, are investigated by the use of the effective field theory with correlations. We find a number of unexpected novel phenomena in them, when the ratio between the transverse field at the surfaces and the transverse field in the inner layer takes a large value; such as the increase of transition temperature, even when the dilution with nonmagnetic atoms at the surfaces is increased. © 2013 Elsevier B.V. Source

Kodera Y.,Nagoya University
Nagoya Journal of Medical Science | Year: 2013

Peritoneal metastasis from gastric cancer is often undetectable by routine imaging studies. Even a microscopic metastasis detected only by cytologic examination of the peritoneal washes denotes a dismal prognosis, and surgery is ruled out as futile for patients who turn out to be cytology-positive by staging laparoscopy. On the other hand, recent developments in cancer chemotherapy have improved the outcome of the cytology-positive population to the point where a certain proportion of these patients survive for 5 years through a straightforward strategy of radical surgery followed by chemotherapy. Thus, there is certainly a role for surgeons in patients with minimal peritoneal metastasis, both in clinical practice and in clinical trials where multimodal treatment strategies including surgery are to be explored. Even in this category of patients, surgery in combination with various types of chemotherapy remains the only hope for a cure. Source

The phase diagrams of two nanoscaled thin films with bond and site dilutions at the surfaces, described by the spin-1 transverse Ising model, are investigated by the use of an effective field theory with correlations. A number of characteristic phenomena have been found in them, which are heavily dependent on the ratios (r = J1/J and p = ΩS/ Ω, where J is the exchange interaction in the inner layer, J1 is the exchange interaction between the surface and the next inner layer, ΩS is the transverse field at the surfaces and Ω is the transverse field in the inner layer). Some of them have exhibited very similar behaviors found in the two spin-1/2 nanoscaled thin films with bond and site dilutions at the surfaces. © 2013 Taylor & Francis. Source

Kaneyoshi T.,Nagoya University
Journal of Physics and Chemistry of Solids | Year: 2015

The phase diagrams and temperature dependences of magnetizations in core-shell transverse Ising nanosystems, namely nanowire, nanotube and nanoparticles, are studied by the use of the effective-field theory with correlations (EFT). Some novel and universal features, such as the possibility of re-entrant phenomena being free from disorder induced frustration, are obtained for the magnetic properties in such systems. © 2015 Elsevier Ltd. All rights reserved. Source

Svalgaard L.,Stanford University | Kamide Y.,Nagoya University
Astrophysical Journal | Year: 2013

The solar polar fields reverse because magnetic flux from decaying sunspots moves toward the poles, with a preponderance of flux from the trailing spots. If there is a strong asymmetry, in the sense that most activity is in the northern hemisphere, then that excess flux will move toward the north pole and reverse that pole first. If there is more activity in the south later on, then that flux will help to reverse the south pole. In this way, two humps in the solar activity and a corresponding difference in the time of reversals develop (in the ideal case). Such a difference was originally noted in the very first observation of polar field reversal just after the maximum of the strongly asymmetric solar cycle 19, when the southern hemisphere was most active before sunspot maximum and the south pole duly reversed first, followed by the northern hemisphere more than a year later, when that hemisphere became most active. Solar cycles since then have had the opposite asymmetry, with the northern hemisphere being most active before solar maximum. We show that polar field reversals for these cycles have all happened in the north first, as expected. This is especially noteworthy for the present solar cycle 24. We suggest that the association of two or more peaks of solar activity when separated by hemispheres with correspondingly different times of polar field reversals is a general feature of the cycle, and that asymmetric polar field reversals are simply a consequence of the asymmetry of solar activity. © 2013. The American Astronomical Society. All rights reserved. Source

Hayashi Y.,Nagoya University
Nihon eiseigaku zasshi. Japanese journal of hygiene | Year: 2012

The hypothesis that offspring growing up malnourished during their fetal period have a high risk of lifestyle diseases in later life has been attracting great attention. Although animal experiments and epidemiological studies have been reported, most of them focused on the deficiency of maternal malnutritional elements or starvation. We found that di(2-ethylhexyl) phthalate (DEHP) decreased maternal plasma triglyceride levels, which is a significant source of nutrients for fetuses, in mice. Therefore, we analyzed how offspring exposed to malnutritional status during their fetal period develop potential adverse effects in later life. Male and female wild-type (mPPARα), Pparα-null, and hPPARα mice were treated with diets containing 0 or 0.05% DEHP. After 4 weeks, males and females in the same genotype and dose group were mated. After continued exposure until weaning, each group was divided into two groups, and one of them was dissected. The remaining was further divided into two subgroups; one was fed normal feed (control-diet group), while the other was fed a high-fat diet (HFD group). After 8-week feeding, all the mice were dissected. In the control-diet group, DEHP exposure at the fetal and pup stages increased food consumption in mPPARα and hPPARα mice, but not in Ppara-null mice. In contrast, DEHP exposure decreased plasma leptin levels in mPPARα and hPPARα mice at the weaning stage. In the HFD group, DEHP exposure at the fetal and pup stages influenced neither food consumption nor leptin levels. These findings suggest that maternal malnutrition may be caused by not only nutritional deficiency but also exposure to some chemicals such as DEHP, and the latter case may also influence feeding behavior in offspring. These effects may be related to hepatic PPARα and diminished by HFD feeding. Further study is warranted as to whether such feeding behavior influences the risk of lifestyle diseases such as obesity. Source

Shimaki Y.,Nagoya University | Arakawa M.,Kobe University
Icarus | Year: 2012

Knowing the collisional process among small porous icy bodies in the outer solar system is a key to understanding the formation of EKBOs and the evolution of icy planetesimals. Impact experiments of sintered porous ice spheres with 40%, 50%, 60% and 70% porosity were conducted by using three types of projectiles at the impact velocity from 2.4 to 489. m/s, and we studied the effects of porosity on the collisional processes. Projectile sticking occurred at the impact velocity higher than 44. m/s for 60% porosity targets and higher than 13. m/s for 70% porosity targets. The antipodal velocity of the porous ice target increased with the increase of energy density, Q, and it increased slightly with the increase of porosity, although it was exceptionally high in cases when the projectile penetrated the target. The shattering strength of porous ice targets was found to decrease from 100 to 31. J/kg with the increase of porosity from 40% to 70%. The cumulative fragment mass distribution was found to depend on the energy density and the target porosity, and the slopes of the distribution in the small fragment region were almost flat for more porous targets. We reanalyzed the cumulative fragment mass distribution and first obtained the empirical equation showing the fragment mass distribution of porous ice targets as a function of the energy density and the porosity. © 2012 Elsevier Inc. Source