Ibaraki, Japan
Ibaraki, Japan

University of Tsukuba , one of the oldest national universities in Japan, is located in the city of Tsukuba, Ibaraki Prefecture in the Kantō region of Japan. The University has 28 college clusters and schools with a total of around 15,000 students . The main Tsukuba campus covers an area of 258 hectares , making it the largest single campus in Japan.It is famous for research in physics, economics, physical education and social science. Its Graduate School of Life and Environmental science is represented on the national Coordinating Committee for Earthquake Prediction. The university is one of the Japanese elite institutions of higher education as part of the Ministry of Education, Culture, Sports, Science and Technology's thirteen "Global 30" selected Project universities. Wikipedia.


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Patent
Kewpie Corporation and University of Tsukuba | Date: 2015-03-05

Hyaluronic acid modified with sphingosine-1-phosphate, and a medicine comprising the hyaluronic acid as an active ingredient, wherein the medicine can alleviate hepatic disorder caused by hypoxia/reoxygenation by protecting the liver sinusoidal endothelial cells, and the medicine can prevent and/or treat liver failure due to liver transplantation, hepatectomy, or other surgeries associated with liver ischemia/reperfusion.


Patent
Fujitsu Limited and University of Tsukuba | Date: 2016-08-04

A storage unit stores therein a collection of structures of biomolecules whose structure varies. A computing unit decreases a temperature set as a temperature parameter, which represents the temperature of the biomolecules, from a prescribed value in steps. When decreasing the temperature of the temperature parameter, the computing unit performs clustering on the structures included in the collection from before the decrease, detects detect outlier structures from the clustering result, and performs molecular dynamics simulations using the temperature parameter with the outlier structures as initial structures. Then, the computing unit stores structures generated by the molecular dynamics simulations in the storage unit.


Patent
Fujitsu Limited and University of Tsukuba | Date: 2016-08-04

An information processing apparatus includes: a memory configured to store a plurality of structures of a substance whose structure changes and a dimension group, which is a group of index dimensions that are indices for structural analysis of the substance, out of a plurality of dimensions that express the structure of the substance; and a processor configured to perform a procedure including: performing, for each of a plurality of candidate dimensions, which are not included in the dimension group, out of the plurality of dimensions, clustering of a plurality of structures in multidimensional space that has every index dimension included in the dimension group and a candidate dimension as coordinate axes; and adding a specified candidate dimension for which it is possible to generate a largest number of clusters to the dimension group as an index dimension.


Patent
Kewpie Corporation and University of Tsukuba | Date: 2017-01-11

Hyaluronic acid modified with sphingosine-1-phosphoate, and a medicine comprising the hyaluronic acid as an active ingredient, wherein the medicine can alleviate hepatic disorder caused by hypoxia/reoxygenation by protecting the liver sinusoidal endothelial cells, and the medicine can prevent and/or treat liver failure due to liver transplantation, hepatectomy, or other surgeries associated with liver ischemia/reperfusion.


Patent
University of Tsukuba and Nihon Kohden | Date: 2017-01-25

An electrocardiogram analyzer includes a first acquiring section that acquires a body surface electrocardiogram of a subject, a second acquiring section that acquires an intracardiac electrocardiogram of a ventricle of a heart of the subject, and an analyzing section that performs a frequency analysis on the intracardiac electrocardiogram and includes a range setting section that sets an analysis time range of the frequency analysis in the intracardiac electrocardiogram based on a unit waveform of the body surface electrocardiogram, and a calculating section that, in the analysis time range, performs the frequency analysis on the intracardiac electrocardiogram, and that calculates an index value indicating a ratio of local abnormal ventricular activities in the intracardiac electrocardiogram.


A biopotential can be measured with high accuracy without the electrodes coming into direct contact with the skin and without being affected by any motion artifact. The present invention comprises a first lead which detects a biopotential containing noise components, a second lead which is electrically isolated from the first lead and detects noise components, and a differential amplifier circuit which is input with a first signal output from the first lead and a second signal output from the second lead, and which amplifies and outputs a difference between the first signal and the second signal, wherein a value of an input impedance on the second signal side of the differential amplifier circuit is set so that the noise components detected from the second lead will have a frequency that is higher than a frequency spectrum of the biopotential.


Patent
Cyberdyne and University of Tsukuba | Date: 2017-04-19

There is provided a wearing-type movement assistance device capable of sufficiently ensuring a degree of freedom of the upper body and coping with a body type difference between wearers. The wearing-type movement assistance device includes a frame to be worn on an upper limb of a wearer, a drive unit provided in each of joints of the frame, a biomedical signal detection unit detecting a biological potential signal of the wearer, a joint angle detection unit detecting an angle of each joint, and a control unit controlling the drive unit based on the biological potential signal and the angle of each joint. The frame includes a vertical frame that extends in a vertical direction, a shoulder frame that is laterally provided in a shoulder width direction from an upper end of the vertical frame, a first arm frame having one end coupled to an end of the shoulder frame via a shoulder joint unit, and a second arm frame having one end coupled to the other end of the first arm frame via an intermediate joint unit and the other end connected to an elbow joint unit. The shoulder joint unit, the intermediate joint unit, and the elbow joint unit are provided with the drive unit.


Patent
Cyberdyne and University of Tsukuba | Date: 2017-04-19

Provided are a prosthesis-mounted action-assist device and a wearable action-assist device that enable step-over-step stair ascending and descending and achieve smooth switching between tasks in accordance with a motion of a wearer. The prosthesis-mounted action-assist device assists an action of a knee disposed between an upper leg frame and a lower leg frame of a prosthetic leg. The device includes an actuator applying power to the prosthetic leg, an absolute angle sensor detecting a hip angle relative to a vertical direction, an angle sensor detecting a knee angle, a floor reaction force sensor detecting a floor reaction force to a wearer, a data storage unit storing reference parameters of phases of tasks, and a control unit comparing the hip angle, the knee angle, and the floor reaction force with the reference parameters stored in the data storage unit to estimate a phase of a task of the wearer and generating an autonomous command signal for causing the actuator to produce power for the phase.


Polarization-sensitive optical image measurement is subject to a non-negligible bias, and consequent deviation in birefringence, in a surrounding range of low SN ratios (signal-to-noise ratios) and low signal strengths; however, this deviation in birefringence is removed to make accurate quantitative measurement possible. Noise-containing OCT signals obtained by polarization OCT are processed using a birefringence calculation algorithm, to obtain measured birefringence, after which noise is statistically adjusted to simulate a measured birefringence distribution and determine the noise characteristics of the measured birefringence values, and then Monte Carlo calculations are repeated by assuming different values for the noise level and the true birefringence value, respectively, to form three-dimensional histogram of combinations of true birefringence values, SN ratios, and measured birefringence values, after which specified measured birefringence values and SN ratios are assumed from the three-dimensional histogram information to obtain a true birefringence probability density distribution, and true birefringence values are estimated from the true birefringence probability density distribution.


Estoque R.C.,University of Tsukuba | Estoque R.C.,Don Mariano Marcos Memorial State University | Murayama Y.,University of Tsukuba
Landscape and Urban Planning | Year: 2013

This study analyzes the dynamics of the socio-ecological system of Baguio City, the summer capital of the Philippines, in order to derive meaningful information for use in planning its sustainable development. Remote sensing data and geographic information systems techniques, in conjunction with spatial metrics and socio-economic information, were used to facilitate the analysis. The spatial and socio-economic components of Baguio's rapid urbanization over the past 21 years (1988-2009) were the major factors that contributed to dramatic changes in the setting's natural landscape, as indicated by an almost threefold increase in its built-up area, at the expense of other land-use/land-cover classes. Its rapid growth has seen the city's population exceed its designed ceiling of 25,000 people by a factor of at least twelve. Such landscape changes and population growth have resulted in a substantial decrease in the overall annual ecosystem service value (ESV) of Baguio of approximately 60%. The human-to-ESV ratio in the city has also decreased over this same period, from 1:31 (US$/year) in 1988 to just 1:7 in 2009. Although Baguio has enjoyed economic, political and social prominence for more than a century, its rapid population growth and urban expansion are now exerting pressure on its natural landscape, jeopardizing the environmental sustainability of this highly valued hill station. This study offers important insights to all, but especially those in fast-urbanizing regions, as Baguio's case offers learning experience valuable for achieving more successful landscape and urban planning. © 2013 Elsevier B.V.


Estoque R.C.,University of Tsukuba | Estoque R.C.,Don Mariano Marcos Memorial State University | Murayama Y.,University of Tsukuba
Applied Geography | Year: 2012

The main purpose of this study is to examine the potential impacts of the past and future land use/cover (LUC) changes on the ecosystem services of Baguio city, the Philippines, and discuss their implications for policy development and implementation. Remote sensing-derived LUC maps for 1988, 1998 and 2009, along with GEOMOD, a Geographic Information Systems-based LUC change model, and ecosystem service value (ESV) coefficients were used to facilitate the analysis. The results revealed a decrease in the ESV of Baguio for the past 21 years (1988-2009), of which a substantial amount was due to loss of forest cover. Consequently, the human-to-ESV (H-ESV) ratio has decreased over the years. The scenario-based LUC change analysis revealed that if the urban LUC change pattern continues, the total ESV and the H-ESV ratio will also continue to decrease in 2020, especially if the forest cover is not fully protected and conserved. Geospatial tools and techniques facilitate exploratory analysis critical to the understanding of the potential impacts of future LUC changes under different scenarios. Our results highlighted that under the great pressure of urbanization, there is a need to strengthen the proper implementation of policies in order to maintain and improve ecosystem services. Although there are limitations to the estimated ESVs of Baguio to be taken into account in future studies, the magnitude of the estimated changes in the LUC is substantial. Thus, it may still be possible to draw general inferences about the effect of the perceived LUC changes on the estimated ESVs. © 2012 Elsevier Ltd.


Fujiu K.,Japan Science and Technology Agency | Nakayama Y.,University of Tsukuba | Nakayama Y.,Tokyo Gakugei University | Iida H.,Tokyo Gakugei University | And 4 more authors.
Nature Cell Biology | Year: 2011

Ciliates and flagellates temporarily swim backwards on collision by generating a mechanoreceptor potential. Although this potential has been shown to be associated with cilia in Paramecium, the molecular entity of the mechanoreceptor has remained unknown. Here we show that Chlamydomonas cells express TRP11, a member of the TRP (transient receptor potential) subfamily V, in the proximal region of the flagella, and that suppression of TRP11 expression results in loss of the avoiding reaction. The results indicate that Chlamydomonas flagella exhibit mechanosensitivity, despite constant motility, by localizing the mechanoreceptor in the proximal region, where active bending is restricted. © 2011 Macmillan Publishers Limited. All rights reserved.


Yamada M.,Tokyo Gakugei University | Akasaka T.,University of Tsukuba | Nagase S.,Kyoto University
Chemical Reviews | Year: 2013

Carbenes are unquestionably powerful intermediates to functionalize fullerenes. Various carbene precursors are useful for reactions. The availability of widely diverse carbene precursors enriches the fullerene chemistry. Both electrophilic and nucleophilic carbenes are applicable reagents, giving the corresponding fullerene derivatives. The reaction mechanisms depend on the precursors and reaction conditions applied. A typical carbene reaction involves addition to a π bond of olefins, which is also the case for a π bond of fullerenes. It is also important to note that carbenes exhibit diverse reactivity. Singlet carbenes possess both electrophilic and nucleophilic character, whereas triplet carbenes show diradical reactivity. Dihalocarbene, because it is among the simplest and most representative carbene species, is widely used in synthetic chemistry. Diazo compounds are useful carbene transfer reagents to fullerenes.


Tatekawa Y.,University of Tsukuba | Muraji T.,Ibaraki Childrens Hospital
European Journal of Cardio-thoracic Surgery | Year: 2011

We reviewed six cases demonstrating acquired tracheomalacia due to innominate artery compression of the trachea and investigated the benefit and effectiveness of a technique for correcting tracheomalacia. All the patients developed scoliosis and the innominate artery run over the trachea. Four cases had permanent neurologic impairment, whereas two patients developed acquired neurologic impairment. The surgical strategy for acquired tracheomalacia due to innominate artery compression of the trachea involved superior mediastinal exposure, external reinforcement with autologous cartilage graft, anterior sling of the innominate artery with a muscle sling, and tracheopexy. Our surgical procedure has been effective in maintaining the patency of the tracheal lumen in all cases but one. This patient suffered from straight back syndrome and developed recurrence of tracheomalacia owing to mucosal infolding secondary to the deformed spine in a supine position. The authors believe our surgical procedure is effective to relieve the symptoms of tracheomalacia, but it is important to select surgical interventions in accordance with the specific patient's condition. © 2010 European Association for Cardio-Thoracic Surgery.


Yang W.,Beijing Normal University | Yang W.,University of Tsukuba | Matsushita B.,University of Tsukuba | Chen J.,Beijing Normal University | Fukushima T.,University of Tsukuba
Remote Sensing of Environment | Year: 2011

Remote estimation of water constituent concentrations in case II waters has been a great challenge, primarily due to the complex interactions among the phytoplankton, tripton, colored dissolved organic matter (CDOM) and pure water. Semi-analytical algorithms for estimating constituent concentrations are effective and easy to implement, but two challenges remain. First, a dataset without a sampling bias is needed to calibrate estimation models; and second, the semi-analytical indices were developed based on several specific assumptions that may not be universally applicable. In this study, a semi-analytical model-optimizing and look-up-table (SAMO-LUT) method was proposed to address these two challenges. The SAMO-LUT method is based on three previous semi-analytical models to estimate chlorophyll a, tripton and CDOM. Look-up tables and an iterative searching strategy were used to obtain the most appropriate parameters in the models. Three datasets (i.e., noise-free simulation data, in situ data and Medium Resolution Imaging Spectrometer (MERIS) satellite data) were collected to validate the performance of the proposed method. The results show that the SAMO-LUT method yields error-free results for the ideal simulation dataset; and is able also to accurately estimate the water constituent concentrations with an average bias (mean normalized bias, MNB) lower than 9% and relative random uncertainty (normalized root mean square error, NRMS) lower than 34% even for in situ and MERIS data. These results demonstrate the potential of the proposed algorithm to accurately monitor inland and coastal waters based on satellite observations. © 2011 Elsevier Inc.


Vong L.B.,University of Tsukuba | Tomita T.,University of Tsukuba | Tomita T.,Timelapse Vision Inc. | Yoshitomi T.,University of Tsukuba | Nagasaki Y.,University of Tsukuba
Gastroenterology | Year: 2012

BACKGROUND & AIMS: Drugs used to treat patients with ulcerative colitis are not always effective because of nonspecific distribution, metabolism in the gastrointestinal tract, and side effects. We designed a nitroxide radical-containing nanoparticle (RNPO) that accumulates specifically in the colon to suppress inflammation and reduce the undesirable side effects of nitroxide radicals. METHODS: RNPO was synthesized by assembly of an amphiphilic block copolymer that contains stable nitroxide radicals in an ether-linked hydrophobic side chain. Biodistribution of RNPO in mice was determined from radioisotope and electron spin resonance measurements. The effects of RNPO were determined in mice with dextran sodium sulfate (DSS)-induced colitis and compared with those of low-molecular-weight drugs (4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl [TEMPOL] or mesalamine). RESULTS: RNPO, with a diameter of 40 nm and a shell of poly(ethylene glycol), had a significantly greater level of accumulation in the colonic mucosa than low-molecular-weight TEMPOL or polystyrene latex particles. RNP O was not absorbed into the bloodstream through the intestinal wall, despite its long-term retention in the colon, which prevented its distribution to other parts of the body. Mice with DSS-induced colitis had significantly lower disease activity index and less inflammation following 7 days of oral administration of RNPO compared with mice with DSS-induced colitis or mice given low-molecular-weight TEMPOL or mesalamine. CONCLUSIONS: We designed an orally administered RNPO that accumulates specifically in the colons of mice with colitis and is more effective in reducing inflammation than low-molecular-weight TEMPOL or mesalamine. RNPO might be developed for treatment of patients with ulcerative colitis. © 2012 AGA Institute.


Tanaka E.,Hamamatsu Photonics K K | Kudo H.,University of Tsukuba
Physics in Medicine and Biology | Year: 2010

We have reported a block-iterative algorithm named DRAMA for image reconstruction for emission tomography (Tanaka and Kudo 2003 Phys. Med. Biol. 48 1405-22). DRAMA is a modified version of the row-action maximum likelihood algorithm (RAMLA), in which the relaxation parameter is subset dependent and is changed in such a way that the noise propagation from subsets to the reconstructed image is substantially independent of the access order of the subsets. The algorithm provides fast convergence with a reasonable signal-to-noise ratio. The optimal relaxation parameter has been derived assuming a two-dimensional (2D)-PET model, and detailed performance in three-dimensional (3D) reconstruction has not been clear enough. We have developed the new version 'DRAMA-3D', based on the 3D-PET model. The optimal relaxation parameter is a function of the access order of the subsets and the ring difference, and its value is determined by simple formulas from the design parameters of the PET scanner, the operating conditions and the post-smoothing resolution. In this paper, we present the theory of DRAMA-3D, the results of simulation studies on the performance of DRAMA-3D and the comparative studies of the related algorithms. It is shown that DRAMA-3D is robust for various access orders of subsets and is suitable to realize one-pass (single-iteration) reconstruction. © 2010 Institute of Physics and Engineering in Medicine.


Suzuki N.,KDDI | Tsuda K.,University of Tsukuba
Procedia Computer Science | Year: 2013

Many research studies are being conducted about the analysis of human behavior using sensor devices in the real world, and a variety of information can be found all over Internet. The primary objective is to improve social behavior and habits, such as the prohibition against smoking and the use mobile phones while driving. These unhealthy social behaviors and habits tend to cause health problems and antisocial behaviors. Behavioral modification specialists understand that habitual behavior is one of the most important behaviors in solving these issues. This paper proposes a new method to extract habitual behaviors for discovering the objectives of the behavioral modification. Specifically, Latent Dirichlet Allocation, or LDA, is used for clustering words into appropriate topics of periodical behaviors from literary expressions, and Point-wise Mutual Information, or PMI, is applied to select suitable words for habitual behaviors. The technique by using text data from question-answering websites from the telecommunications industry area was evaluated and showed good performance results. © 2013 The Authors.


Honda Y.,University of Tsukuba | Ono M.,Association of International Research Initiatives for Environmental Studies
Environmental Health and Preventive Medicine | Year: 2011

Objectives: The objective of this study was to assess the relation between temperature and suicide mortality in Japan using time series analysis with a semiparametric approach. Methods: We analyzed the relation between daily fluctuations in suicide mortality and maximum temperatures for all regions in Japan over the period of time from 1972 to 1995 using a generalized additive model. The model controls for the time trend, season, selected meteorological parameters, day of the week, and holiday. Adjustment was based using penalized splines and the decision on the amount of smoothness was based on minimizing the unbiased risk estimation criterion. Results: The results show that suicide mortality in Japan has a seasonal character and it varies from year to year, with the highest occurrence in April, as well as in the first part of the week, especially on Mondays and Tuesdays. As for the day of the week, there were only few suicide cases on Saturdays and holidays. We found that for all regions in Japan when temperature increased the suicide mortality increased on the same day (lag = 0). Analysis by method of suicide showed that when temperature increased mortality significantly increased only for suicide by a violent method. The pattern of the relation for other methods remained unclear. Conclusions: This study suggests that an increase in temperature has a short-term effect on suicide mortality in Japan. © 2010 The Japanese Society for Hygiene.


Hamano J.,University of Tsukuba | Tokuda Y.,Mito Kyodo General Hospital
Journal of Primary Care and Community Health | Year: 2014

Background: Although several previous studies have examined the prevalence and risk factors associated with inappropriate prescribing (IP) among elderly patients, as identified by the Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) and Screening Tool to Alert doctors to Right Treatment (START) criteria, no research has been conducted among elderly home care patients. Objective: This study aimed to explore the prevalence of IP and its risk factors as identified by the STOPP/START criteria among elderly home care patients in Japan. Study Design: Crosssectional study. Setting: Home care settings in Japan. Participants: Eighty-nine patients aged 65 years or older who received regular home visiting services from Yamato Clinic between May 2013 and June 2013. Main Outcome Measure: The prevalence of IP and its risk factors as identified by the STOPP/START criteria. Results: Of the study population, 40.4% had at least one potentially inappropriate medication and 60.7% had at least one incidence of underprescribing. Risk factors for potentially inappropriate medications were hypertension, constipation, and polypharmacy, while those for underprescription were osteoporosis and polypharmacy. Conclusion: The prevalence of IP among elderly home care patients is high, with risk factors that include not only polypharmacy but also several specific underlying medical conditions. © The Author(s) 2014.


Takisawa K.,University of Tsukuba | Kanemoto K.,Research Institute of Tsukuba Bio Technology Corporation | Miyazaki T.,Research Institute of Tsukuba Bio Technology Corporation | Kitamura Y.,University of Tsukuba
Bioresource Technology | Year: 2013

Hydrolysis of lipids from microalgae under high water content was investigated as a pretreatment of direct esterification. Results indicated that the hydrolysis process reduced the inhibition by water in FAME production; in addition, FAME obtained by esterification of hydrolysates was increased by 181.7% compared to FAME obtained by direct transesterification under the same amount of water content (80%). This method has great potential in terms of biodiesel production from microalgae since it uses no organic solvent, reduces the drying cost and lowers the operating cost compared to any other traditional method. © 2013 Elsevier Ltd.


Sawada H.,Nippon Telegraph and Telephone | Araki S.,Nippon Telegraph and Telephone | Makino S.,University of Tsukuba
IEEE Transactions on Audio, Speech and Language Processing | Year: 2011

This paper presents a blind source separation method for convolutive mixtures of speech/audio sources. The method can even be applied to an underdetermined case where there are fewer microphones than sources. The separation operation is performed in the frequency domain and consists of two stages. In the first stage, frequency-domain mixture samples are clustered into each source by an expectationmaximization (EM) algorithm. Since the clustering is performed in a frequency bin-wise manner, the permutation ambiguities of the bin-wise clustered samples should be aligned. This is solved in the second stage by using the probability on how likely each sample belongs to the assigned class. This two-stage structure makes it possible to attain a good separation even under reverberant conditions. Experimental results for separating four speech signals with three microphones under reverberant conditions show the superiority of the new method over existing methods. We also report separation results for a benchmark data set and live recordings of speech mixtures. © 2010 IEEE.


Wolf T.,University of Stuttgart | Neumann P.,University of Stuttgart | Nakamura K.,Energy Research Company | Sumiya H.,Sumitomo Electric Industries | And 3 more authors.
Physical Review X | Year: 2015

Nitrogen-vacancy (NV) defect centers in diamond are promising solid-state magnetometers. Single centers allow for high-spatial-resolution field imaging but are limited in their magnetic field sensitivity. Using defect-center ensembles, sensitivity can be scaled with √N p when N is the number of defects. In the present work, we use an ensemble of N ~ 1011 defect centers within an effective sensor volume of 8.5 × 10-4 mm3 for sensing at room temperature. By carefully eliminating noise sources and using highquality diamonds with large NV concentrations, we demonstrate, for such sensors, a sensitivity scaling as 1= √t p, where t is the total measurement time. The associated photon-shot-noise-limited magnetic-field sensitivity for ac signals of f = 20 kHz is 0.9 pT= √Hz. For a total measurement time of 100 s, we reach a standard deviation of about 100 fT. Further improvements using decoupling sequences and material optimization could lead to fT= √Hz p sensitivity.


Santosh M.,Kochi University | Liu S.J.,Chinese Academy of Geological Sciences | Tsunogae T.,University of Tsukuba | Li J.H.,Peking University
Precambrian Research | Year: 2012

Ultrahigh-temperature (UHT) metamorphic rocks associated with the 'Khondalite Belt' within the Inner Mongolia Suture Zone (IMSZ) provide robust evidence for extreme thermal metamorphism in the North China Craton (NCC). The IMSZ marks the collisional suture between the Yinshan Block to the north and the Ordos Block to the South as the NCC was incorporated within the Columbia supercontinent amalgam during Paleoproterozoic. Here we present a synthesis of the salient features of the UHT rocks from the NCC including petrologic indicators, fluid characteristics, and monazite and zircon chronometry on the extreme crustal metamorphism. The granulites carry diagnostic UHT mineral assemblages including sapphirine+quartz, low Zn/Fe3+ spinel+quartz, high alumina orthopyroxene+sillimanite+quartz and high temperature mesoperthite. The stability fields of the typical mineral assemblages, conventional geothermobarometry and phase equilibria modeling using pseudosections as reported in a number of recent studies converge to indicate that these UHT rocks experienced metamorphic temperatures up to or in excess of 1000°C at ca. 10kbar, followed by an isobaric cooling segment. The rocks were exhumed along a near-isothermal decompression path. Microstructures, mineral reactions and phase equilibria modeling suggest an anti-clockwise P-T path, similar to those displayed by metamorphic orogens developed in subduction-collision settings. The dominant category of fossil fluids preserved within the major UHT minerals is CO2, consistent with the stability of the broadly anhydrous mineral assemblage in these rocks. Both chemical and radiogenic isotopic ages from monazite and zircon chronometry suggest the timing of the UHT event as around 1.92Ga. The Paleoproterozoic high grade metamorphism younging from 1.95Ga in the western domain to 1.92Ga in the eastern domain of the Khondalite Belt might suggest a scissor-like closure of oblique collision between the Yinshan and the Ordos Blocks.The salient features of the UHT metamorphism in the NCC include: (1) extreme metamorphic temperatures at moderate pressures, (2) dominantly anhydrous nature of the mineral assemblages, typically the stability of orthopyroxene, (3) common presence of CO2-rich fluid inclusions as the trace of the ambient fluid, (4) regional extent of the UHT granulites, and (5) the association of the UHT orogen with an accretionary belt in a continental collisional suture. We evaluate the diverse models on the generation of UHT orogens including their formation in thickened and inverted back-arcs, orogen self-heating through heat producing elements, heat and CO2 input by plume impingement below a carbonated tectosphere, and asthenospheric upwelling through ridge subduction and slab-window process or during post-collisional slab break-off. The ultra-hot and dry UHT rocks in the NCC provide one of the well preserved examples from the Paleoproterozoic globe for investigating extreme metamorphism and related tectonic processes within the plate tectonic paradigm. © 2011 Elsevier B.V.


Nabekura T.,University of California at San Francisco | Kanaya M.,University of Tsukuba | Shibuya A.,University of Tsukuba | Fu G.,Scripps Research Institute | And 3 more authors.
Immunity | Year: 2014

Recent studies demonstrate that natural killer (NK) cells have adaptive immune features. Here, we investigated the role of the costimulatory molecule DNAM-1 in the differentiation of NK cells in a mouse model of cytomegalovirus (MCMV) infection. Antibody blockade of DNAM-1 suppressed the expansion of MCMV-specific Ly49H+ cells during viral infection and inhibited the generation of memory NK cells. Similarly, DNAM-1-deficient (Cd226-/-) Ly49H+ NK cells exhibited intrinsic defects in expansion and differentiation into memory cells. Src-family tyrosine kinase Fyn and serine-threonine protein kinase C isoform eta (PKCη) signaling through DNAM-1 played distinct roles in the generation of MCMV-specific effector and memory NK cells. Thus, cooperative signaling through DNAM-1 and Ly49H are required for NK cell-mediated host defense against MCMV infection. © 2014 Elsevier Inc.


Kaneda T.,Hakuoh University | Nishihira Y.,University of Tsukuba
Clinical Neurophysiology | Year: 2012

Objective: We examined the modulation of event-related brain potentials (ERPs) and the accuracy of sensori-motor coordination on short-term repetition of the concurrent performance of a somatosensory discrimination (oddball) task and a visuo-motor tracking task. Methods: The subjects concurrently performed visuomotor tracking and somatosensory oddball tasks. In the dual-task condition, the subjects performed the visuomotor tracking and somatosensory oddball tasks concurrently for about an hour. In the oddball-only condition, they performed just the oddball task for the same period. Results: Tracking performance improved with task repetition. The amplitude of the P300 elicited by somatosensory stimulation in the oddball-only condition decreased significantly with task repetition, whereas in the dual-task condition, it showed a complex pattern of change. The earlier responses were decreased in amplitude in the dual-task condition compared to the oddball-only condition, and gradually decreased with task repetition in both conditions. Conclusions: Dynamic changes in ERPs and task performance with dual-task repetition support the idea that dual-task repetition produces changes in resource allocation following the automation of stimulus processing in addition to so-called habituation. Significance: This study also provides evidence for use of ERP amplitudes as physiological indices of functionally different types of resources. © 2011 International Federation of Clinical Neurophysiology.


Takahashi F.,RIKEN | Mizoguchi T.,University of Tsukuba | Yoshida R.,Kagoshima University | Ichimura K.,Kagawa University | Shinozaki K.,RIKEN
Molecular Cell | Year: 2011

Rapid recognition and signal transduction of mechanical wounding through various signaling molecules, including calcium (Ca 2+), protein phosphorylation, and reactive oxygen species (ROS), are necessary early events leading to stress resistance in plants. Here we report that an Arabidopsis mitogen-activated protein kinase 8 (MPK8) connects protein phosphorylation, Ca 2+, and ROS in the wound-signaling pathway. MPK8 is activated through mechanical wounding, and this activation requires direct binding of calmodulins (CaMs) in a Ca 2+-dependent manner. MPK8 is also phosphorylated and activated by a MAPKK MKK3 in the prototypic kinase cascade, and full activation of MPK8 needs both CaMs and MKK3 in planta. The MPK8 pathway negatively regulates ROS accumulation through controlling expression of the Rboh D gene. These findings suggest that two major activation modes in eukaryotes, Ca 2+/CaMs and the MAP kinase phosphorylation cascade, converge at MPK8 to monitor or maintain an essential part of ROS homeostasis. © 2011 Elsevier Inc.


Solem R.C.,University of California at San Francisco | Eames B.F.,University of Oregon | Tokita M.,University of Tsukuba | Schneider R.A.,University of California at San Francisco
Developmental Biology | Year: 2011

Secondary cartilage occurs at articulations, sutures, and muscle attachments, and facilitates proper kinetic movement of the skeleton. Secondary cartilage requires mechanical stimulation for its induction and maintenance, and accordingly, its evolutionary presence or absence reflects species-specific variation in functional anatomy. Avians illustrate this point well. In conjunction with their distinct adult mode of feeding via levered straining, duck develop a pronounced secondary cartilage at the insertion (i.e., enthesis) of the mandibular adductor muscles on the lower jaw skeleton. An equivalent cartilage is absent in quail, which peck at their food. We hypothesized that species-specific pattern and a concomitant dissimilarity in the local mechanical environment promote secondary chondrogenesis in the mandibular adductor enthesis of duck versus quail. To test our hypothesis we employed two experimental approaches. First, we transplanted neural crest mesenchyme (NCM) from quail into duck, which produced chimeric "quck" with a jaw complex resembling that of quail, including an absence of enthesis secondary cartilage. Second, we modified the mechanical environment in embryonic duck by paralyzing skeletal muscles, and by blocking the ability of NCM to support mechanotransduction through stretch-activated ion channels. Paralysis inhibited secondary cartilage, as evidenced by changes in histology and expression of genes that affect chondrogenesis, including members of the FGF and BMP pathways. Ion channel inhibition did not alter enthesis secondary cartilage but caused bone to form in place of secondary cartilage at articulations. Thus, our study reveals that enthesis secondary cartilage forms through mechanisms that are distinct from those regulating other secondary cartilage. We conclude that by directing the musculoskeletal patterning and integration of the jaw complex, NCM modulates the mechanical forces and molecular signals necessary to control secondary cartilage formation during development and evolution. © 2011 Elsevier Inc.


In measurement data selection, when a vector composed of measurement data obtained for respective combinations of light emitting positions, light detection positions, and resolving times in a time-resolved waveform is given as y, a vector in which pixel values of learning image data are components is given as x, and a system matrix for calculating internal image data from the measurement data is given as A_(1), the vector y which meets the conditional expressions (2) and (3) miny_(0)^(0)(2), xA_(1)^(T)y_(2)^(2)^(2)(3) or the conditional expression (4) min(y_(0)^(0)+xA_(1)^(T)y_(2)^(2))(4) is determined, and upon measurement of a subject, only the measurement data corresponding to nonzero components of the vector y is used to prepare the internal image data.


Human life and the entire ecosystem of South East Asia depend upon the monsoon climate and its predictability. More than 40% of the earths population lives in this region. Droughts and floods associated with the variability of rainfall frequently cause serious damage to ecosystems in these regions and, more importantly, injury and loss of human life. The headwater areas of seven major rivers in SE Asia, i.e. Yellow River, Yangtze, Mekong, Salween, Irrawaddy, Brahmaputra and Ganges, are located in the Tibetan Plateau. Estimates of the Plateau water balance rely on sparse and scarce observations that cannot provide the required accuracy, spatial density and temporal frequency. Fully integrated use of satellite and ground observations is necessary to support water resources management in SE Asia and to clarify the roles of the interactions between the land surface and the atmosphere over the Tibetan Plateau in the Asian monsoon system. The goal of this project is to: 1. Construct out of existing ground measurements and current / future satellites an observing system to determine and monitor the water yield of the Plateau, i.e. how much water is finally going into the seven major rivers of SE Asia; this requires estimating snowfall, rainfall, evapotranspiration and changes in soil moisture; 2. Monitor the evolution of snow, vegetation cover, surface wetness and surface fluxes and analyze the linkage with convective activity, (extreme) precipitation events and the Asian Monsoon; this aims at using monitoring of snow, vegetation and surface fluxes as a precursor of intense precipitation towards improving forecasts of (extreme) precipitations in SE Asia. A series of international efforts initiated in 1996 with the GAME-Tibet project. The effort described in this proposal builds upon 10 years of experimental and modeling research and the consortium includes many key-players and pioneers of this long term research initiative.


Patent
Sumitomo Electric Industries and University of Tsukuba | Date: 2014-01-15

A carbon nanostructures geometry and electrical characteristics can be controlled. A method for processing a carbon nanostructure according to the present invention includes the steps of: preparing a carbon nanostructure (e.g., a carbon nanotube (1)) (a CNT preparation step); and exposing the carbon nanotube (1) to an energy beam (e.g., an electron beam) while vibrating the carbon nanotube (1) (an exposure step). This facilitates modifying the carbon nanotube (1) in length and electrical characteristics.


Patent
Center de Biotechnologie de la Technopole de Borj-Cedria and University of Tsukuba | Date: 2012-11-26

Obesity is one of the major health concerns in the Twenty-First Century and is one of the leading causes of preventable death. It is a strong risk factor for Type 2 Diabetes. Disclosed herein are compositions and methods using Nitraria retusa extracts for enhancing energy metabolism, inhibiting fat accumulation, inhibiting preadipocyte differentiation, reducing diabetic hypercholesterolemia, and for treating or ameliorating obesity.


The present disclosure provides a method for assessing the environmental effects of alkylbenzenesulfonate (LAS). For example, the method includes contacting a population of cells with a sample, measuring an expression level of one or more LAS biomarkers in the cell population, comparing the level of expression of the one or more LAS biomarker to one or more reference values corresponding to the one or more LAS biomarkers, and determining an LAS risk associated with the sample.


Patent
University of Tsukuba and Sumitomo Electric Industries | Date: 2012-03-08

A carbon nanostructures geometry and electrical characteristics can be controlled. A method for processing a carbon nanostructure according to the present invention includes the steps of: preparing a carbon nanostructure (e.g., a carbon nanotube) (a CNT preparation step); and exposing the carbon nanotube to an energy beam (e.g., an electron beam) while vibrating the carbon nanotube (an exposure step). This facilitates modifying the carbon nanotube in length and electrical characteristics.


Patent
University of Sfax and University of Tsukuba | Date: 2013-08-09

The present invention relate to a highly efficient and novel method, using clean technologies, for obtaining a natural bioactive concentrate that is rich on polyphenols from olive mill water (OMW). The clean technologies integrate centrifugation, a drowning-out crystallization-based separation process, and vacuum evaporation. The method provides a highly-concentrated polyphenol isolate (up to 99% (mass fraction)) from other components presents in OMW, with up to half of the polyphenol content being hydroxytyrosol. The isolated polyphenols exhibit anti-oxidant, anti-microbial, anti-inflammatory, and anti-carcinogenic activities; they can be prepared as solid particles, as an aqueous solution, in an emulsion, or as lipidic-based nanoparticles. The isolated polyphenols can be used in the food industry, cosmetic industry, or pharmaceutical industry.


Miura K.,University of Tsukuba | Tada Y.,Kagawa University
Frontiers in Plant Science | Year: 2014

Salicylic acid (SA) is a naturally occurring phenolic compound. SA plays an important role in the regulation of plant growth, development, ripening, and defense responses. The role of SA in the plant-pathogen relationship has been extensively investigated. In addition to defense responses, SA plays an important role in the response to abiotic stresses, including drought, low temperature, and salinity stresses. It has been suggested that SA has great agronomic potential to improve the stress tolerance of agriculturally important crops. However, the utility of SA is dependent on the concentration of the applied SA, the mode of application, and the state of the plants (e.g., developmental stage and acclimation). Generally, low concentrations of applied SA alleviate the sensitivity to abiotic stresses, and high concentrations of applied induce high levels of oxidative stress, leading to a decreased tolerance to abiotic stresses. In this article, the effects of SA on the water stress responses and regulation of stomatal closure are reviewed. © 2014 Miura and Tada.


Han C.,University of Electro - Communications | Suehiro N.,University of Tsukuba | Hashimoto T.,University of Electro - Communications
IEEE Transactions on Information Theory | Year: 2011

The complete complementary code (CCC) that was proposed by Suehiro and Hatori is a sequence family, that is a set of sequence sets, with ideal correlation sums. Numerous studies in the literature show its applications to direct-spread code-division multiple access (DS-CDMA) systems for interchannel interference (ICI)-free communication with improved spectral efficiency. In this paper, we propose a systematic framework for the construction of CCCs based on N -shift cross-orthogonal sequence families (N-CO-SFs). We show theoretical bounds on the size of N-CO-SFs and CCCs and give a set of four algorithms for their generation and extension. The algorithms are optimal in the sense that the size of the resultant sequence families achieves theoretical bounds and, with the algorithms, we can construct an optimal CCC consisting of sequences whose lengths are not only almost arbitrary but even variable between sequence sets. We also discuss the family size, alphabet size, and length of constructible CCCs based on the proposed algorithms. © 2011 IEEE.


Daeneke T.,Monash University | Uemura Y.,Japan National Institute of Advanced Industrial Science and Technology | Uemura Y.,University of Tsukuba | Duffy N.W.,CSIRO | And 5 more authors.
Advanced Materials | Year: 2012

Solar energy conversion efficiencies of over 4% have been achieved in DSCs constructed with aqueous electrolytes based on the ferricyanide-ferrocyanide redox couple, thereby avoiding the use of expensive, flammable and toxic solvents. This paradigm shift was made possible by the use of a hydrophobic organic carbazole dye. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Culturing cells and tissues in vitro hasprovided valuable insights into the molecular mechanisms regulating redox signaling in cells with implications for medicine. However, standard culture techniques maintain mammalian cells in vitro under an artificial physicochemical environment such as ambient air and 5% CO2. Oxidative stress is caused by the rapid oxidation of cysteine to cystine in culture media catalyzed by transition metals, leading to diminished intracellular cysteine and glutathione (GSH) pools. Some cells, such as fibroblasts and macrophages, express cystine transport activity, designated as systemxc-, which enables cells to maintain these pools to counteract oxidative stress. Additionally, many cells have the ability to activate the redox sensitive transcription factor Nrf2, a master regulator of cellular defenses against oxidative stress, and to upregulate xCT, the subunit of the xc- transport system leading to increases in cellular GSH. In contrast, some cells, including lymphoid cells, embryonic stem cells and iPS cells, express relatively low levels of xCT and cannot maintain cellular cysteine and GSH pools. Thus, fibroblasts have been used as feeder cells for the latter cell types based on their ability to supply cysteine. Other key Nrf2 regulated gene products include heme oxygenase 1, peroxiredoxin 1 and sequestosome1. In macrophages, oxidized LDL activates Nrf2 and upregulates the scavenger receptor CD36 forming a positive feedback loop to facilitate removal of the oxidant from the vascular microenvironment. This review describes cell type specific responses to oxygen derived stress, and the key roles that activation of Nrf2 and membrane transport of cystine and cysteine play in the maintenance and proliferation of mammalian cells in culture. © 2014 The Authors.


Yasukochi Y.,University of Tsukuba | Satta Y.,Graduate University for Advanced Studies
G3: Genes, Genomes, Genetics | Year: 2014

An extraordinary diversity of amino acid sequences in the peptide-binding region (PBR) of human leukocyte antigen [HLA; human major histocompatibility complex (MHC)] molecules has been maintained by balancing selection. The process of accumulation of amino acid diversity in the PBR for six HLA genes (HLA-A, B, C, DRB1, DQB1, and DPB1) shows that the number of amino acid substitutions in the PBR among alleles does not linearly correlate with the divergence time of alleles at the six HLA loci. At these loci, some pairs of alleles show significantly less nonsynonymous substitutions at the PBR than expected from the divergence time. The same phenomenon was observed not only in the HLA but also in the rat MHC. To identify the cause for this, DRB1 sequences, a representative case of a typical nonlinear pattern of substitutions, were examined. When the amino acid substitutions in the PBR were placed with maximum parsimony on a maximum likelihood tree based on the non-PBR substitutions, heterogeneous rates of nonsynonymous substitutions in the PBR were observed on several branches. A computer simulation supported the hypothesis that allelic pairs with low PBR substitution rates were responsible for the stagnation of accumulation of PBR nonsynonymous substitutions. From these observations, we conclude that the nonsynonymous substitution rate at the PBR sites is not constant among the allelic lineages. The deceleration of the rate may be caused by the coexistence of certain pathogens for a substantially long time during HLA evolution. © 2014 Yasukochi and Satta.


Schone C.,UK National Institute for Medical Research | Apergis-Schoute J.,University of Cambridge | Sakurai T.,Kanazawa University | Sakurai T.,University of Tsukuba | And 4 more authors.
Cell Reports | Year: 2014

Stable wakefulness requires orexin/hypocretin neurons (OHNs) and OHR2 receptors. OHNs sense diverse environmental cues and control arousal accordingly. For unknown reasons, OHNs contain multiple excitatory transmitters, including OH peptides and glutamate. To analyze their cotransmission within computational frameworks for control, we optogenetically stimulated OHNs and examined resulting outputs (spike patterns) in a downstream arousal regulator, the histamine neurons (HANs). OHR2s were essential for sustained HAN outputs. OHR2-dependent HAN output increased linearly during constant OHN input, suggesting that the OHN→HANOHR2 module may function as an integral controller. OHN stimulation evoked OHR2-dependent slow postsynaptic currents, similar to midnanomolar OH concentrations. Conversely, glutamate-dependent output transiently communicated OHN input onset, peaking rapidly then decaying alongside OHN→HAN glutamate currents. Blocking glutamate-driven spiking did not affect OH-driven spiking and vice versa, suggesting isolation (low cross-modulation) of outputs. Therefore, in arousal regulators, cotransmitters may translate distinct features of OHN activity into parallel, nonredundant control signals for downstream effectors. © 2014 The Authors.


Sato H.,University of Tsukuba | Takenaka I.,Okayama College | Kawahara J.I.,Japan National Institute of Advanced Industrial Science and Technology
Quarterly Journal of Experimental Psychology | Year: 2012

Selective attention can be improved under conditions in which a high perceptual load is assumed to exhaust cognitive resources, leaving scarce resources for distractor processing. The present study examined whether perceptual load and acute stress share common attentional resources by manipulating perceptual and stress loads. Participants identified a target within an array of nontargets that were flanked by compatible or incompatible distractors. Attentional selectivity was measured by longer reaction times in response to the incompatible than to the compatible distractors. Participants in the stress group participated in a speech test that increased anxiety and threatened self-esteem. The effect of perceptual load interacted with the stress manipulation in that participants in the control group demonstrated an interference effect under the low perceptual load condition, whereas such interference disappeared under the high perceptual load condition. Importantly, the stress group showed virtually no interference under the low perceptual load condition, whereas substantial interference occurred under the high perceptual load condition. These results suggest that perceptual and stress related demands consume the same attentional resources. © 2012 The Experimental Psychology Society.


Miyagi A.,Chiba Institute of Technology | Nabetani H.,Japan National Agriculture and Food Research Organization | Nakajima M.,University of Tsukuba
Separation and Purification Technology | Year: 2012

In the present study, transport mechanisms of various binary systems such as alcohol-hexane, alkane-hexane, lipid-hexane, and diesel fuel-kerosene systems through a PDMS-based dense membrane were investigated using a combined regular solution (RS) and solution-diffusion (SD) model at constant pressure and temperature. The combined model contains many important factors for permeability such as diffusivity, degree of swelling membrane, membrane thickness, and osmotic pressure. Total, hexane, and solvent fluxes (except for a part of the solvent flux) of all systems were controlled by molar volumes of hexane and solvent and solubility parameters of hexane, solvent, and membrane polymer based on the combined model. The selectivity of the solvent in these systems seems to depend upon the similarity of the molecular structures of hexane and solvent, corresponding to entropy mixing, and the interaction of the hexane-solvent- membrane polymer, corresponding to enthalpy mixing. The combined model could well describe the transport mechanism of the binary system. © 2011 Elsevier B.V. All rights reserved.


Parry O.H.,Durham University | Eke V.R.,Durham University | Frenk C.S.,Durham University | Okamoto T.,Durham University | Okamoto T.,University of Tsukuba
Monthly Notices of the Royal Astronomical Society | Year: 2012

We investigate the formation and evolution of satellite galaxies using smoothed particle hydrodynamics (SPH) simulations of a Milky Way (MW) like system, focusing on the best resolved examples, analogous to the classical MW satellites. Comparing with a pure dark matter simulation, we find that the condensation of baryons has had a relatively minor effect on the structure of the satellites' dark matter haloes. The stellar mass that forms in each satellite agrees relatively well over three levels of resolution (a factor of ∼64 in particle mass) and scales with (sub)halo mass in a similar way in an independent semi-analytical model. Our model provides a relatively good match to the average luminosity function of the MW and M31. To establish whether the potential wells of our satellites are realistic, we measure their masses within observationally determined half-light radii, finding that they have somewhat higher mass-to-light ratios than those derived for the MW dSphs from stellar kinematic data; the most massive examples are most discrepant. A statistical test yields an ∼6 per cent probability that the simulated and observationally derived distributions of masses are consistent. If the satellite population of the MW is typical, our results could imply that feedback processes not properly captured by our simulations have reduced the central densities of subhaloes, or that they initially formed with lower concentrations, as would be the case, for example, if the dark matter were made of warm, rather than cold particles. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.


Ko J.-H.,Hallym University | Kim T.H.,Hallym University | Roleder K.,University of Silesia | Rytz D.,Edelsteine Edelmetalle GmbH FEE | Kojima S.,University of Tsukuba
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

The acoustic anomalies and precursor dynamics of high-quality barium titanate single crystals were investigated by Brillouin light scattering and the birefringence measurements in the paraelectric phase above the cubic-to-tetragonal ferroelectric phase transition temperature (Tc). Two elastic stiffness coefficients C11 and C44, the related sound velocities, and their absorption coefficients were determined from Tc to 400C for the first time. The longitudinal acoustic (LA) mode showed a substantial softening over a wide temperature range above Tc which was accompanied by a remarkable increase in the acoustic damping as well as growth of central peaks. The broad central peak (CP) exhibited a two-mode and one-mode behavior in the paraelectric and ferroelectric phase, respectively, which was consistent with recent far-infrared reflectivity measurements and first-principle-based calculations. The acoustic anomalies and CP behavior were correlated with the anomalous birefringence, piezoelectric effect, and the deviation of the Curie-Weiss law observed from the same crystal. This strongly indicates similarity between the dynamics of polar clusters in typical ferroelectrics and the dynamics of polar nanoregions in relaxors, consistent with recent acoustic emission measurements. The relaxation times estimated from the central peak and the LA mode anomalies exhibited similar temperature dependences with comparable orders of magnitude, indicating that the polarization fluctuations due to the precursor polar clusters couples to the LA mode through density fluctuations. All these anomalies share common microscopic origin, correlated Ti off-centered motions forming polar clusters having local symmetry breaking in the paraelectric phase. The existence of the polar clusters were directly evidenced by the temperature evolution of the precise birefringence map. The narrow central peak within ±5 GHz proposed before was not confirmed to exist in the present study. © 2011 American Physical Society.


Suzuki H.,University of Tsukuba | Tomoda A.,University of Fukui
BMC Psychiatry | Year: 2015

Background: Although exposure to early life stress is known to affect mental health, the underlying mechanisms of its impacts on depressive symptoms among institutionalized children and adolescents have been little studied. Methods: To investigate the role of attachment and self-esteem in association with adverse childhood experiences (ACEs) and depressive symptoms, 342 children (149 boys, 193 girls; age range 9-18 years old, mean age = 13.5 ± 2.4) living in residential foster care facilities in Japan completed questionnaires related to internal working models, self-esteem, and depressive symptoms. Their care workers completed questionnaires on ACEs. Results: Structural equation modeling (SEM) was created and the goodness of fit was examined (CMIN = 129.223, df = 1.360, GFI = .959, AGFI = .936, CFI = .939, RMSEA = .033). Maltreatment negatively predicted scores on secure attachment, but positively predicted scores on avoidant and ambivalent attachment. The secure attachment score negatively predicted depressive symptoms. The ambivalent attachment score positively predicted depressive symptoms both directly and through self-esteem, whereas the avoidant attachment score positively predicted depressive symptoms only directly. Maltreatment neither directly predicts self-esteem nor depressive symptoms, and parental illness/death and parental sociopathic behaviors did not predict any variables. Conclusions: Results show that the adversity of child maltreatment affects depression through attachment styles and low self-esteem among institutionalized children. Implications of child maltreatment and recommendations for child welfare services and clinical interventions for institutionalized children are discussed. © 2015 Suzuki and Tomoda; licensee BioMed Central.


Hase M.,University of Pittsburgh | Hase M.,University of Tsukuba | Katsuragawa M.,University of Electro - Communications | Constantinescu A.M.,University of Pittsburgh | Petek H.,University of Pittsburgh
Nature Photonics | Year: 2012

High-order nonlinear light-matter interactions in gases enable the generation of X-ray and attosecond light pulses, metrology and spectroscopy 1. Optical nonlinearities in solid-state materials are particularly interesting for combining optical and electronic functions for high-bandwidth information processing2. Third-order nonlinear optical processes in silicon have been used to process optical signals with bandwidths greater than 1 GHz (ref. 2). However, fundamental physical processes for a silicon-based optical modulator in the terahertz bandwidth range have not yet been explored. Here, we demonstrate ultrafast phononic modulation of the optical index of silicon by irradiation with intense few-cycle femtosecond pulses. The anisotropic reflectivity modulation by the resonant Raman susceptibility at the fundamental frequency of the longitudinal optical phonon of silicon (15.6 THz) generates a frequency comb up to seventh order. All-optical >100 THz frequency comb generation is realized by harnessing the coherent atomic motion of the silicon crystalline lattice at its highest mechanical frequency. © 2012 Macmillan Publishers Limited. All rights reserved.


Nabekura T.,University of California at San Francisco | Nabekura T.,University of Tsukuba | Girard J.-P.,Institut Universitaire de France | Lanier L.L.,University of California at San Francisco
Journal of Immunology | Year: 2015

NK cells provide important host defense against viruses and can differentiate into self-renewing memory NK cells after infection, alloantigen stimulation, and cytokine stimulation. In this study, we investigated the role of the IL-33 receptor ST2 in the differentiation of NK cells during mouse CMV (MCMV) infection. Although ST2-deficient (Il1rl1-/-) Ly49H+ NK cells develop normally and differentiate into memory cells after MCMV infection, naive and memory Il1rl1-/- Ly49H+ NK cells exhibited profound defects in MCMV-specific expansion, resulting in impaired protection against MCMV challenge. Additionally, IL-33 enhanced m157 Ag-specific proliferation of Ly49H+ NK cells in vitro. Thus, an IL-33/ST2 signaling axis in NK cells contributes to host defense against MCMV. Copyright © 2015 by The American Association of Immunologists, Inc.


Aoki S.,Kyoto University | Aoki S.,University of Tsukuba | Creutz M.,Brookhaven National Laboratory
Physical Review Letters | Year: 2014

We investigate some aspects of two-flavor QCD with mu≠md at low energy, using the leading order chiral perturbation theory including anomaly effects. While nothing special happens at mu=0 for the fixed md≠0, the neutral pion mass becomes zero at two critical values of mu, between which the neutral pion field condenses, leading to a spontaneously CP broken phase, the so-called Dashen phase. We also show that the "topological susceptibility" in the chiral perturbation theory diverges at these two critical points. We briefly discuss a possibility that mu=0 can be defined by the vanishing the "topological susceptibility. We finally analyze the case of mu=md=m with θ=π, which is equivalent to mu=-md=-m with θ=0 by the chiral rotation. In this case, the η condensation occurs at small m, violating the CP symmetry spontaneously. Deep in the η condensation phase, three pions become Nambu-Goldstone bosons, but they show unorthodox behavior at small m that mπ2=O(m2), which, however, is shown to be consistent with the chiral Ward-Takahashi identities. © 2014 American Physical Society.


Murakami H.,University of Hawaii at Manoa | Hsu P.-C.,University of Hawaii at Manoa | Hsu P.-C.,Nanjing University of Information Science and Technology | Arakawa O.,University of Tsukuba | Li T.,University of Hawaii at Manoa
Journal of Climate | Year: 2014

The influence of model biases on projected future changes in the frequency of occurrence of tropical cyclones (FOCs) was investigated using a new empirical statistical method. Assessments were made of present-day (1979-2003) simulations and future (2075-99) projections, using atmospheric general circulation models under the Intergovernmental Panel on Climate Change (IPCC) A1B scenario and phase 5 of the Coupled Model Intercomparison Project (CMIP5) models under the representative concentration pathway (RCP) 4.5 and 8.5 scenarios. The models project significant decreases in global-total FOCs by approximately 6%-40%; however, model biases introduce an uncertainty of approximately 10%in the total future changes.The influence of biases depends on themodel physics rather than model resolutions and emission scenarios. In general, the biases result in overestimates of projected future changes in basin-total FOCs in the north Indian Ocean (by +18%) and South Atlantic Ocean (+143%) and underestimates in the western North Pacific Ocean (-27%), eastern North Pacific Ocean (-29%), and North Atlantic Ocean (-53%). The calibration of model performance using the smaller bias influence appears crucial to deriving meaningful signals in future FOC projections. To obtain more reliable projections, ensemble averages were calculated using the models less influence by model biases. Results indicate marked decreases in projected FOCs in the basins of the Southern Hemisphere, Bay of Bengal, western North Pacific Ocean, eastern North Pacific, and Caribbean Sea and increases in the Arabian Sea and the subtropical central Pacific Ocean. © 2014 American Meteorological Society.


Ozawa M.,University of Tsukuba | Kuroiwa T.,University of Tsukuba | Ikeda A.,University of Tsukuba | Ikeda A.,CNRS Charles Coulomb Laboratory | Miyazaki K.,University of Tsukuba
Physical Review Letters | Year: 2012

Recent studies show that volume fractions φ J at the jamming transition of frictionless hard spheres and disks are not uniquely determined but exist over a continuous range. Motivated by this observation, we numerically investigate the dependence of φ J on the initial configurations of the parent fluid equilibrated at a volume fraction φ eq, before compressing to generate a jammed packing. We find that φ J remains constant when φ eq is small but sharply increases as φ eq exceeds the dynamic transition point which the mode-coupling theory predicts. We carefully analyze configurational properties of both jammed packings and parent fluids and find that, while all jammed packings remain isostatic, the increase of φ J is accompanied with subtle but distinct changes of local orders, a static length scale, and an exponent of the finite-size scaling. These results are consistent with the scenario of the random first-order transition theory of the glass transition. © 2012 American Physical Society.


Hu Z.,University of Electro - Communications | Han X.,CAS Beijing Institute of Applied Physics And Computational Mathematics | Li Y.,CAS Beijing Institute of Applied Physics And Computational Mathematics | Kato D.,Japan National Institute for Fusion Science | And 2 more authors.
Physical Review Letters | Year: 2012

We report the experimentally determined angular distribution of the [1s2s22p 1/2] 1→[1s22s2] 0 transition in dielectronic recombination of Li-like Au. Recently, Fritzsche et al. predicted that the Breit interaction plays a dominant role in the angular distribution of this transition. However, the predicted phenomenon has not yet been observed experimentally due to technical difficulties in conventional methods. To overcome the difficulties, we combine two different measurements with an electron beam ion trap (EBIT) to obtain the x-ray angular distribution. One is the x-ray measurement at 90° and another is the integral resonant strength measurement through the ion charge abundance in the EBIT. Our measurements agree well with the theoretical prediction and confirm the dominance of the Breit interaction. © 2012 American Physical Society.


Vladisavljevic G.T.,Loughborough University | Kobayashi I.,Japan National Agriculture and Food Research Organization | Nakajima M.,Japan National Agriculture and Food Research Organization | Nakajima M.,University of Tsukuba
Microfluidics and Nanofluidics | Year: 2012

This review provides an overview of major microengineering emulsification techniques for production of monodispersed droplets. The main emphasis has been put on membrane emulsification using Shirasu Porous Glass and microsieve membrane, microchannel emulsification using grooved-type and straight-through microchannel plates, microfluidic junctions and flow focusing microfluidic devices. Microfabrication methods for production of planar and 3D poly(dimethylsiloxane) devices, glass capillary microfluidic devices and single-crystal silicon microchannel array devices have been described including soft lithography, glass capillary pulling and microforging, hot embossing, anisotropic wet etching and deep reactive ion etching. In addition, fabrication methods for SPG and microseive membranes have been outlined, such as spinodal decomposition, reactive ion etching and ultraviolet LIGA (Lithography, Electroplating, and Moulding) process. The most widespread application of micromachined emulsification devices is in the synthesis of monodispersed particles and vesicles, such as polymeric particles, microgels, solid lipid particles, Janus particles, and functional vesicles (liposomes, polymersomes and colloidosomes). Glass capillary microfluidic devices are very suitable for production of core/shell drops of controllable shell thickness and multiple emulsions containing a controlled number of inner droplets and/or inner droplets of two or more distinct phases. Microchannel emulsification is a very promising technique for production of monodispersed droplets with droplet throughputs of up to 100 l h -1. © 2012 Springer-Verlag.


Tang F.,Shanghai JiaoTong University | Barolli L.,Fukuoka Institute of Technology | Li J.,University of Tsukuba
IEEE Transactions on Industrial Informatics | Year: 2014

Data communication in mobile ad hoc cognitive networks (MACNets) significantly suffers from link instability and channel interference. The availability and stability of each link in MACNets highly depends on not only the relative movement of neighbor nodes but also the adjacent communication among primary nodes and among cognitive nodes. In multihop and multiflow MACNets, this problem becomes even worse because multiple links potentially interfere with each other. In this paper, we propose a cross-layer distributed approach, called mobility-prediction-based joint stable routing and channel assignment (MP-JSRCA), to maximize the network throughput by jointly selecting stable routes and assigning channels avoiding inter- and intra-flow interferences based on mobility prediction. To quantitatively measure the communication quality of links, we propose a new metric data transmission cost (DTC) that captures node mobility, impact to primary nodes, and channel conflict among cognitive nodes. In our MP-JSRCA, each relay node selects the best link with the smallest DTC as the next hop, within a specified sector region towards the destination. NS2-based simulation results demonstrate that our MP-JSRCA algorithm significantly improves network throughput, and the higher degree of interference MACNets experience, the more improvement can be achieved. © 2012 IEEE.


Nishijima T.,Japan National Agriculture and Food Research Organization | Nishijima T.,University of Tsukuba
Journal of the Japanese Society for Horticultural Science | Year: 2012

Large flower size is an important trait that influences the economic value of floricultural plants. Large flower size is conferred by two morphological changes i.e. increased petal number and individual petal size. Increased petal number is induced by enlargement of the floral meristem or homeotic conversion of stamens and carpels into petals. Genes regulating meristematic competence mediate enlargement of the floral meristem, while floral homeotic genes mediate the homeotic conversion of floral organs. Increased individual petal size is induced by increased cell size or cell number. Polyploidization of the nuclear genome increases petal cell size, while increased petal cell number is induced by enhanced expression of the genes involved in auxin signal transduction and cytokinin biosynthesis. In this review, the molecular mechanisms affecting flower size, elucidated mainly using model plants such as Arabidopsis, are summarized. Further, our research on the roles of cytokinin biosynthesis and signal transduction in increased flower size in petunia, induced by the single major gene Grandiflora, is discussed. Based on these results, a possible systematic breeding method for increasing flower size is discussed.© 2012.


Yamashita A.,Nara Women's University | Watanabe A.,Nara Women's University | Akine S.,University of Tsukuba | Nabeshima T.,University of Tsukuba | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2011

Designer SMM: An ErIII-based single-molecule magnet (SMM) was synthesized by designing the ligand-field anisotropy around an ErIII ion in an equatorial arrangement of donors using a rigid and planar macrocyclic Schiff base ligand including three ZnII ions. The resulting Er IIIZnII3 complex (see picture; C gray, O red, N blue) behaves as a SMM with an energy barrier of 24.6(9) K for flipping of the molecular magnetic moment. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Nabekura T.,University of California at San Francisco | Nabekura T.,University of Tsukuba | Lanier L.L.,University of California at San Francisco
Immunity | Year: 2016

Natural killer (NK) cells are important in host defense against pathogens, and they can subsequently differentiate into memory NK cells. The Ly49 and KIR gene families in rodents and humans encode both inhibitory and activating receptors for MHC class I. The physiological role of activating KIR or Ly49 receptors that recognize self-MHC class I during immune response to viral infections is unknown. Here, we address how the activating Ly49D receptor impacts the NK cell response to mouse cytomegalovirus (MCMV) infection by comparing the activation and differentiation of Ly49D-bearing NK cells in mice lacking or expressing H-2Dd, the cognate MHC class I ligand of Ly49D. After MCMV infection, Ly49D augmented IFN-γ production by MCMV-specific Ly49H+ NK cells and preferentially promoted the generation of memory Ly49H+ NK cells. Thus, activating receptors for self-MHC class I modulate the differentiation of MCMV-specific NK cells and are beneficial for host defense against MCMV infection. © 2016 Elsevier Inc.


Aoki S.,University of Tsukuba | Aoki S.,Brookhaven National Laboratory | Fukaya H.,Nagoya University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We consider chiral perturbation theory with a nonzero θ term. Because of the CP violating term, the vacuum of chiral fields is shifted to a nontrivial element on the SU(Nf) group manifold. The CP violation also provides mixing of different CP eigenstates, between scalar and pseudoscalar, or vector and axialvector, operators. We investigate up to O(θ2) effects on the mesonic two-point correlators of chiral perturbation theory to the one-loop order. We also address the effects of fixing topology, by using saddle-point integration in the Fourier transform with respect to θ. © 2010 The American Physical Society.


Oh M.,University of Tsukuba | Oh M.,Japan National Agriculture and Food Research Organization | Komatsu S.,University of Tsukuba | Komatsu S.,Japan National Agriculture and Food Research Organization
Journal of Proteomics | Year: 2015

Flooding and drought affect soybean growth because soybean is a stress-sensitive crop. In 2-day-old plants exposed to 2-day flooding or drought, the fresh weight of roots was markedly suppressed, although the root morphology clearly differed between two conditions. To understand the response mechanisms of soybean to flooding and drought stresses, a gel-free proteomic technique was used. A total of 97 and 48 proteins were significantly changed in response to flooding and drought stresses, respectively. Proteins involved in protein synthesis were decreased by flooding stress and increased by drought. Glycolysis-related proteins were increased in roots by both flooding and drought stresses. Fermentation, stress, and cell wall-related proteins were increased in response to flooding stress, whereas cell organization and redox-related proteins were increased under drought stress. Among the identified proteins, three S-adenosylmethionine synthetases were commonly decreased and increased in response to flooding and drought stresses, respectively. The mRNA expression levels of S-adenosylmethionine synthetase genes displayed a similar tendency to the changes in protein abundance. These results suggest that S-adenosylmethionine synthetase is involved in the regulation of stress response because it was changed in response to flooding and drought stresses. Biological significance: This study reported on the response mechanisms of soybean to flooding and drought stresses using the gel-free proteomic technique. Proteins involved in protein synthesis were decreased by flooding stress and increased by drought. Glycolysis-related proteins were increased in roots by both flooding and drought stresses. Fermentation, stress, and cell wall-related proteins were increased in response to flooding stress, whereas cell organization and redox-related proteins were increased under drought stress. Among the identified proteins, three S-adenosylmethionine synthetases were commonly decreased and increased in response to flooding and drought stresses, respectively. The mRNA expression levels of S-adenosylmethionine synthetase genes displayed a similar tendency to the changes in protein abundance. These results suggest that S-adenosylmethionine synthetase is involved in the regulation of stress response because it was changed in response to flooding and drought stresses. © 2014 Elsevier B.V.


Morita T.,Seirei Mikatahara General Hospital | Kizawa Y.,University of Tsukuba
Current Opinion in Supportive and Palliative Care | Year: 2013

Purpose of review Providing palliative care in Japan is one of the most important health issues. Understanding palliative care delivery systems of other countries is useful when developing and modifying palliative care systems worldwide. This review summarizes the current status of palliative care in Japan, focusing on the structure and process development. Recent findings Palliative care units and hospital palliative care consultation teams are the two main specialized palliative care services in Japan. The number of palliative care units is 215 (involved in 8.4% of all cancer deaths), and there are approximately 500 hospital palliative care teams. Conversely, specialized home care services are one of the most undeveloped areas in Japan. However, the government has been trying to develop more efficient home care services through modifying laws, healthcare systems, and multiple educational and cooperative projects. The numbers of palliative care specialists are increasing across all disciplines: cancer pain nurses (1365), palliative care nurses (1100), palliative care physicians (646), and palliative care pharmacists (238). Postgraduate education for physicians is performed via the special nationwide efforts of the Palliative care Emphasis program on symptom management and Assessment for Continuous medical Education (PEACE) project - a 2-day program adopting a trainer-trainee strategy. Over 30 000 physicians have participated in the PEACE program. A total of 1298 and 544 physicians have completed a trainer course for palliative medicine and psycho-oncology, respectively. Multiple structure and process evaluation, bereaved family surveys in palliative care units, and patient and family evaluation in the regional palliative care program indicate many improvements. Summary Palliative care in Japan has progressed rapidly, and the Cancer Control Act has played a very important role in developing palliative medicine. Challenges include developing a structure for palliative care in the community or regional palliative care programs, establishing a method to measure and improve the quality of palliative care at a national level, developing evidence-based medicine and policy making, and palliative care for the noncancerous population. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.


Wang X.,University of Tsukuba | Li J.,University of Tsukuba | Tang F.,Shanghai JiaoTong University
IEEE Transactions on Parallel and Distributed Systems | Year: 2015

Cooperative communication, which utilizes neighboring nodes to relay the overhearing information, has been employed as an effective technique to deal with the channel fading and to improve the network performances. Network coding, which combines several packets together for transmission, is very helpful to reduce the redundancy at the network and to increase the overall throughput. Introducing network coding into the cooperative retransmission process enables the relay node to assist other nodes while serving its own traffic simultaneously. To leverage the benefits brought by both of them, an efficient Medium Access Control (MAC) protocol is needed. In this paper, we propose a novel network coding aware cooperative MAC protocol, namely NCAC-MAC, for wireless ad hoc networks. The design objective of NCAC-MAC is to increase the throughput and reduce the delay. Simulation results reveal that NCAC-MAC can improve the network performance under general circumstances comparing with two benchmarks. © 2015 IEEE.


Fukui K.,University of Tsukuba | Maki A.,KTH Royal Institute of Technology
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2015

Subspace-based methods are known to provide a practical solution for image set-based object recognition. Based on the insight that local shape differences between objects offer a sensitive cue for recognition, this paper addresses the problem of extracting a subspace representing the difference components between class subspaces generated from each set of object images independently of each other. We first introduce the difference subspace (DS), a novel geometric concept between two subspaces as an extension of a difference vector between two vectors, and describe its effectiveness in analyzing shape differences. We then generalize it to the generalized difference subspace (GDS) for multi-class subspaces, and show the benefit of applying this to subspace and mutual subspace methods, in terms of recognition capability. Furthermore, we extend these methods to kernel DS (KDS) and kernel GDS (KGDS) by a nonlinear kernel mapping to deal with cases involving larger changes in viewing direction. In summary, the contributions of this paper are as follows: 1) a DS/KDS between two class subspaces characterizes shape differences between the two respectively corresponding objects, 2) the projection of an input vector onto a DS/KDS realizes selective visualization of shape differences between objects, and 3) the projection of an input vector or subspace onto a GDS/KGDS is extremely effective at extracting differences between multiple subspaces, and therefore improves object recognition performance. We demonstrate validity through shape analysis on synthetic and real images of 3D objects as well as extensive comparison of performance on classification tests with several related methods; we study the performance in face image classification on the Yale face database B+ and the CMU Multi-PIE database, and hand shape classification of multi-view images. © 2015 IEEE.


Patent
Fujitsu Limited and University of Tsukuba | Date: 2016-02-01

An information processing apparatus includes: an outlying structure detecting unit that uses a certain outlier detection method to detect, from a distribution of molecular structures in a structural space, molecular structures deviating from others; an outlying degree specifying unit that specifies outlying degrees for the respective detected molecular structures; and an MD simulation executing unit that executes molecular simulations with initial structures set to the molecular structures to which weights are assigned in such a manner that a larger weight is assigned to a molecular structure for which the higher outlying degree has been specified.


News Article | December 6, 2016
Site: www.eurekalert.org

It is not well understood what role sleep loss plays in affecting areas of the brain that control the desire to consume unhealthy foods. A new paper published on December 6 in the journal eLife finds that rapid eye movement (REM) sleep loss leads to increased consumption of unhealthy foods, specifically sucrose and fat. The researchers at the University of Tsukuba's International Institute for Integrative Sleep Medicine (IIIS) used a new method to produce REM sleep loss in mice along with a chemical-genetic technique to block prefrontal cortex neurons and the behaviors they mediate. As a result, the IIIS researchers discovered that inhibiting these neurons reversed the effect of REM sleep loss on sucrose consumption while having no effect on fat consumption. REM sleep is a unique phase of sleep in mammals that is closely associated with dreaming and characterized by random eye movement and almost complete paralysis of the body. The prefrontal cortex plays a role in judging the palatability of foods through taste, smell and texture. Moreover, persons who are obese tend to have increased activity in the prefrontal cortex when exposed to high calorie foods. "Our results suggest that the medial prefrontal cortex may play a direct role in controlling our desire to consume weight promoting foods, high in sucrose content, when we are lacking sleep," says Kristopher McEown, the lead author on this project. IIIS was launched by the Ministry of Education, Culture, Sports, Science and Technology of Japan with the aim of building globally visible research centers. At IIIS gather globally prominent scientists from multiple research fields contributing to elucidate the fundamental principles of sleep/wake regulation, and develop new strategies to assess and treat sleep diseases as well as the closely associated metabolic and mental disorders. The research was funded by the Japan Society for the Promotion of Science.


News Article | November 2, 2016
Site: www.sciencedaily.com

The first unbiased genetic screen for sleep defects in mice has yielded two interesting mutants, Sleepy, which sleeps excessively, and Dreamless, which lacks rapid eye movement (REM) sleep. The findings are the first step towards discovering the biochemistry that controls the switch from wakefulness to sleep, the researchers say. Although sleep is essential for life and we spend one third of our lives doing it, the function of sleep, and the physiology that regulates it, remain longstanding mysteries in biology. Researchers have hypothesized that there is a substance that builds up when we are awake, and then has to be discharged or recovered while we are sleeping. "But we still don't understand those processes," said HHMI Investigator Joseph Takahashi at the University of Texas Southwestern Medical Center in Dallas. To address these issues, Takahashi and former HHMI Investigator Masashi Yanagisawa, now Professor in the International Institute for Integrative Sleep Medicine at the University of Tsukuba in Japan, decided to take an unbiased exploratory approach. Instead of beginning with a hypothesis about specific genes that might be involved, the researchers introduced random genetic mutations in more than 8,000 mice and screened them using electroencephalography (EEG) to determine which ones had abnormal sleep as a result of the genetic perturbations. "The barrier in the past has been that it's a very laborious process. To do a genetic screen, you should be prepared to screen thousands of animals before you find something interesting, and most people are just not willing to measure EEGs in thousands of mice," explained Takahashi. But by optimizing the surgical methods, electrodes, and the software to analyze the EEGs in automated fashion, the researchers were able to conduct the first unbiased genetic screen of this magnitude for sleep defects in mice, which they report in this week's issue of Nature. The researchers identified two mutations, which they called Sleepy and Dreamless, and subsequently mapped them to locations in the mouse genome. Sleepy mice, which need approximately one third more sleep than normal mice, carry a mutation in the Sik3 kinase gene. Because the Sik3 kinase can phosphorylate many proteins, it is likely to be involved in many signaling pathways, which makes it trickier to characterize. To investigate why Sleepy mice need more sleep, the researchers examined the circadian clock in Sleepy mice, but they did not find a circadian rhythm disturbance. They tested whether the mice had defects in their arousal system by stimulating them with environmental (e.g., a new cage) and pharmacological (e.g, caffeine and modafinil) stimuli, but found that the mice had normal arousal responses. They concluded that the Sleepy mice had an increased sleep need, but the physiological reasons for that remained unclear. "Sleep need still remains a mystery, but what we hope is that this kinase is maybe the key, the initial key to this big door," said Yanagisawa. Dreamless mice, which have reduced rapid eye movement (REM) sleep, carry a mutation in a sodium channel. Understanding the effects of the dreamless mutation was more straightforward. The mutation increases the conductivity of a leaky sodium channel that was previously known to regulate neuronal excitability. The neuronal populations that terminate REM sleep have too much excitability, said Yanagisawa, which is why the mice have reduced REM sleep. The researchers are optimistic that the screen will yield more mutants with sleep defects to investigate. "We really hope that this is opening up some mysteries ... this is just the beginning," said Yanagisawa.


News Article | November 2, 2016
Site: www.eurekalert.org

DALLAS - November 2, 2016 - Researchers have identified the first two core genes that regulate the amount of deep sleep and dreaming, a key development they believe will lead to the discovery of a network of related genes controlling sleep. The study from the Peter O'Donnell Jr. Brain Institute demonstrates in mice that a single gene controls the amount of non-REM (rapid eye movement) sleep, which includes deep sleep. A second gene controls the amount or need for REM sleep, associated with vivid dreaming. The findings provide a critical molecular entry point to explain how sleep works and to identify potential targets to better treat sleep disorders. "This research is just the beginning. We believe that these two genes are the first of many that regulate sleep," said study co-author Dr. Joseph S. Takahashi, Chairman of Neuroscience with the O'Donnell Brain Institute at UT Southwestern Medical Center and Investigator in the Howard Hughes Medical Institute. Previous research has identified genes that regulate the switch between wakefulness and sleep. But until this latest study in Nature, scientists have not known what mechanisms control the drive or need for non-REM sleep, nor the amount of REM sleep. To find out, researchers used a forward-genetic approach in which they screened for sleep disorders in 8,000 mice using electroencephalogy (EEG) to monitor brain waves. They found two distinct pedigrees of note: Researchers introduced these same mutations into normal mice and saw their sleep behaviors change accordingly. "We hope this is the entry door to the black box that explains how our sleep is regulated," said the senior co-author Dr. Masashi Yanagisawa, an Adjunct Professor of Molecular Genetics at UT Southwestern and former HHMI Investigator. He now directs the International Institute for Integrative Sleep Medicine (IIIS) at the University of Tsukuba in Japan, where most of the mice were screened. Normal sleep patterns include short durations of REM sleep surrounded by longer stretches of non-REM sleep and account for about a quarter of a night's rest in most young adults. Many forms of sleep disorder distort these patterns. Because the Sik3 and Nalcn genes have just been identified, no evidence yet exists to link them directly to known sleep disturbances in humans. However, while the role and importance of REM sleep remains a point of debate, many scientists agree this stage of rest is involved in the formation of emotional memories and coping with negative experiences. Thus, a lack of REM sleep may contribute to conditions such as posttraumatic stress disorder (PTSD). "At least in theory, this study opens up future possibilities to create new sleep-regulating drugs, but doing so will occur in the distant future," said Dr. Yanagisawa, noting that the proteins produced by Sik3 and Nalcn could possibly be molecular targets for new medicines. Dr. Takahashi used a forward-genetic approach two decades ago to make a landmark discovery of the Clock gene that regulates the body's biological clock. The finding led his team to discover a network of more than 20 other related genes. Dr. Takahashi said he expects the screen for sleep genes will lead to more genes, forming perhaps a much larger group than the clock genes because sleep affects more parts of the brain. What's unclear is how big a part the other genes in that network play in regulating sleep. The Takahashi lab found that only a handful of the clock genes have a crucial role in the larger network. "If the same is true for sleep, this is going to be a simplifying, illuminating discovery," said Dr. Takahashi, holder of the Loyd B. Sands Distinguished Chair in Neuroscience and 2016 recipient of the Peter Farrell Prize in Sleep Medicine. Dr. Takahashi said he had wanted to conduct such a genetic screen for sleep mutants for many years but had to overcome logistical issues to conduct a large-scale effort. Most mouse studies involve no more than a few dozen animals, but Dr. Yanagisawa rapidly scaled up and optimized his lab's ability to screen large numbers of mice initially at UT Southwestern and now at his institute in Japan. "To be able to screen 8,000 mice is something that most people would say is too much work," said Dr. Takahashi, explaining that each mouse had to be surgically wired for the EEG readings, among other steps. "Technically, this project was very challenging." About UT Southwestern Medical Center UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution's faculty includes many distinguished members, including six who have been awarded Nobel Prizes since 1985. The faculty of almost 2,800 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in about 80 specialties to more than 100,000 hospitalized patients and oversee approximately 2.2 million outpatient visits a year. This news release is available on our website at http://www. . To automatically receive news releases from UT Southwestern via email, subscribe at http://www. A study from the Peter O'Donnell Jr. Brain Institute has identified the first two core genes that regulate the amount of deep sleep and dreaming. While normal sleep patterns include short durations of rapid eye movement (REM) sleep surrounded by longer stretches of non-REM sleep, the study published in Nature demonstrates how one gene can alter these patterns. Here's a look at the stages of sleep: REM: Rapid eye movement sleep, associated with vivid dreaming. Brain waves are similar to those experienced during wakefulness. Breathing, heart rate and blood pressure increase. Muscles become paralyzed, protecting the person from acting out dreams. Person is more likely to wake from REM than non-REM sleep, though the awakenings usually last only a few seconds. While the role and importance of REM sleep remains a point of debate, many scientists agree it is involved in the formation of emotional memories and coping with negative experiences. Stage 1: Between wakefulness and sleep. The heart rate begins to slow and breathing becomes regular. Dreaming is relatively rare. The person may be aware of sounds and may have quick body jerks. If awakened, the person will often believe they were not asleep. Brain waves begin to transition from beta/gamma to slower alpha waves, then theta waves. Stage 2: Muscle activity decreases and awareness of outside sounds recedes. Sigma waves, or sleep spindles, provide short bursts of brain activity that combine with other low and high voltage peaks. These protect the person's sleeping state from outside disruptions and help with processing memory and other information. The person passes through this stage several times each night, usually accounting for about half the total sleep. Stage 3: Deep sleep. The person is completely removed from outside stimuli and will feel groggy if awakened. Heart rate, breathing and blood pressure are at their lowest levels. Dreaming is more common at this stage than other non-REM stages, though not as common as during REM sleep. Like in stage 2, memory and information processing occur during this stage. Sleep walking or talking may also occur.


News Article | November 2, 2016
Site: www.eurekalert.org

The first unbiased genetic screen for sleep defects in mice has yielded two interesting mutants, Sleepy, which sleeps excessively, and Dreamless, which lacks rapid eye movement (REM) sleep. The findings are the first step towards discovering the biochemistry that controls the switch from wakefulness to sleep, the researchers say. Although sleep is essential for life and we spend one third of our lives doing it, the function of sleep, and the physiology that regulates it, remain longstanding mysteries in biology. Researchers have hypothesized that there is a substance that builds up when we are awake, and then has to be discharged or recovered while we are sleeping. "But we still don't understand those processes," said HHMI Investigator Joseph Takahashi at the University of Texas Southwestern Medical Center in Dallas. To address these issues, Takahashi and former HHMI Investigator Masashi Yanagisawa, now Professor in the International Institute for Integrative Sleep Medicine at the University of Tsukuba in Japan, decided to take an unbiased exploratory approach. Instead of beginning with a hypothesis about specific genes that might be involved, the researchers introduced random genetic mutations in more than 8,000 mice and screened them using electroencephalography (EEG) to determine which ones had abnormal sleep as a result of the genetic perturbations. "The barrier in the past has been that it's a very laborious process. To do a genetic screen, you should be prepared to screen thousands of animals before you find something interesting, and most people are just not willing to measure EEGs in thousands of mice," explained Takahashi. But by optimizing the surgical methods, electrodes, and the software to analyze the EEGs in automated fashion, the researchers were able to conduct the first unbiased genetic screen of this magnitude for sleep defects in mice, which they report in this week's issue of Nature. The researchers identified two mutations, which they called Sleepy and Dreamless, and subsequently mapped them to locations in the mouse genome. Sleepy mice, which need approximately one third more sleep than normal mice, carry a mutation in the Sik3 kinase gene. Because the Sik3 kinase can phosphorylate many proteins, it is likely to be involved in many signaling pathways, which makes it trickier to characterize. To investigate why Sleepy mice need more sleep, the researchers examined the circadian clock in Sleepy mice, but they did not find a circadian rhythm disturbance. They tested whether the mice had defects in their arousal system by stimulating them with environmental (e.g., a new cage) and pharmacological (e.g, caffeine and modafinil) stimuli, but found that the mice had normal arousal responses. They concluded that the Sleepy mice had an increased sleep need, but the physiological reasons for that remained unclear. "Sleep need still remains a mystery, but what we hope is that this kinase is maybe the key, the initial key to this big door," said Yanagisawa. Dreamless mice, which have reduced rapid eye movement (REM) sleep, carry a mutation in a sodium channel. Understanding the effects of the dreamless mutation was more straightforward. The mutation increases the conductivity of a leaky sodium channel that was previously known to regulate neuronal excitability. The neuronal populations that terminate REM sleep have too much excitability, said Yanagisawa, which is why the mice have reduced REM sleep. The researchers are optimistic that the screen will yield more mutants with sleep defects to investigate. "We really hope that this is opening up some mysteries ... this is just the beginning," said Yanagisawa.


News Article | November 16, 2016
Site: www.nature.com

Male C57BL/6J mice (CLEA Japan) were treated with ethylnitrosourea (85 mg kg−1, Sigma-Aldrich) by intraperitoneal injection twice at weekly intervals at the age of 8 weeks. At the age of 25–30 weeks, the sperm of the mice was used for in vitro fertilization with eggs of C57BL/6N mice to obtain F offspring. Mice were provided food and water ad libitum, and were maintained on a 12-h light:12-h dark cycle and housed under controlled temperature and humidity conditions. All procedures were approved by the Institutional Animal Care and Use Committee of the University of Tsukuba and the RIKEN BioResource Center, University of Texas Southwestern Medical Center at Dallas. EEG/EMG electrode implantation was performed as described previously35, with isoflurane (3% for induction, 1% for maintenance) used for anaesthesia. Seven days after surgery, the mice were tethered to a counterbalanced arm (Instech Laboratories) that allowed free movement and exerted minimal weight. At the age of 12 weeks, male mice were implanted with EEG/EMG electrodes and then screened for sleep/wakefulness behaviour. Examined parameters were total time spent in wake, NREMS and REMS states, episode duration of wake, NREMS and REMS states, appearance of muscle atonia during REMS, and rebound sleep after 4-h sleep deprivation by shaking the cages. For quantitative parameters, we selected mice whose phenotypes deviated from the average by at least 3 standard deviations. After confirming the reproducibility of the sleep phenotype, the mice were selected for offspring production by natural mating or IVF with wild-type females to examine the heritability of the sleep phenotypes. If at least 30% of the male littermates showed sleep phenotypes similar to their father, we considered the sleep abnormalities to be heritable. Single nucleotide polymorphisms of N mice were determined using a custom TaqMan Genotyping assay (Thermo Fisher). The custom probes were designed based on the polymorphism data between C57BL/6J and C57BL/6N (ref. 20). QTL analysis was performed using J/qtl software (Jackson Laboratory). Whole exomes were captured with SureSelectXT2 Mouse All Exon (Agilent) and processed to a paired end 2 × 100-bp run on the Illumina HiSeq2000 platform at the UTSW McDermott Center Next Generation Sequencing Core. Reads were mapped to the University of California Santa Cruz mm9 genome reference sequence for C57BL/6J using Burrows–Wheeler aligner and quality filtered using SAMtools. Cleaned BAM files were used to realign data and call variants using the Genome Analysis ToolKit to detect heterozygous mutations. The recording room was kept under 12-h light:12-h dark cycles and a constant temperature (24–25 °C). To examine sleep–wake behaviour under baseline conditions, EEG/EMG signals were recorded for two consecutive days from the onset of the light phase. EEG/EMG data were visualized and analysed using a MatLab (MathWorks)-based, custom semi-automated staging program followed by visual inspection. EEG signals were subjected to fast Fourier transform analysis from 1 to 30 Hz with 1-Hz bin using MatLab-based custom software. Epochs containing movement artefacts were included in the state totals but excluded from subsequent spectral analysis. Sleep/wakefulness was staged into wakefulness, NREMS and REMS. Wakefulness was scored based on the presence of low amplitude, fast EEG, and high amplitude, variable EMG. NREMS was characterized by high amplitude, delta (1–4 Hz) frequency EEG and low EMG tonus, whereas REMS was staged based on theta (6–9 Hz)-dominant EEG and EMG atonia. Hourly delta density during NREMS indicates hourly averages of delta density which is the ratio of delta power to total EEG power at each 20-s epoch. For the power spectrum of sleep/wakefulness, the EEG power of each frequency bins was expressed as a percentage of the total EEG power over all frequency bins (1–30 Hz) and sleep/wakefulness states35, 36. For sleep deprivation, mice were sleep deprived for 2, 4 and 6 h from the onset of the light phase by gently touching the cages when they started to recline and lower their heads. Food and water were available. To evaluate the effect of sleep deprivation, the NREMS delta power during the first hour after sleep deprivation was expressed relative to the same zeitgeber time (ZT) of the basal recording or relative to the mean of the basal recording. For caffeine and modafinil injection experiments, mice were fully acclimatized for intraperitoneal injection before sleep recording. After 24-h baseline recording, mice received caffeine (Sigma), modafinil (Sigma) or vehicle (0.5% methyl cellulose (Wako)) intraperitoneally at ZT0, followed by 12-h recording. Injections were delivered once per week, with each injection followed by a 6–8-day washout period, during which mice remained in the recording chamber. To examine the sleep/wakefulness behaviour under constant darkness, after 48-h recording under a 12-h light:12-h dark cycle, EEG/EMG recording continued in constant darkness for 3 days. Mice were housed individually in a cage (width 23 cm, length 33 cm, height 14 cm) containing a wireless running wheel (Med Associate ENV-044). Cages were placed in a light-tight chamber equipped with green LED light (100 lx at the bottom of the cage). The rotation numbers of wheels were obtained with 1-min bin using Wheel manager software (Med Associate). Mice were entrained to 12-h light:12-h dark cycle for 7 days, and then released into constant darkness for 3 weeks. The free running period was calculated with linear regression analysis of activity onset using MatLab-based custom software. Circadian activity amplitude was calculated by fast Fourier transform of activity data, which were processed with Bartlett window using MatLab-based custom software. Relative amplitude was normalized to the mean amplitude of the wild- type group. A rabbit polyclonal antibody against the C-terminal 171 amino acids of mouse SIK3 was generated using custom antibody production service (Pacific Immunology). Tissues were homogenized using a rotor-stator homogenizer (Polytron) in ice-cold lysis buffer (20 mM HEPES, pH 7.5, 100 mM NaCl, 10 mM Na P O , 1.5% Triton X-100,15 mM NaF, 1× PhosSTOP (Roche), 5 mM EDTA, 1× protease inhibitor (Roche)), and then centrifuged at 13,000g at 4 °C. The supernatants were separated by SDS–PAGE and transferred on PVDF membrane. Western blotting was performed according to standard protocols. In situ hybridization was performed as described previously37. In brief, a 0.7–0.8-kb fragment of Nalcn cDNA was inserted into pGEM-T easy (Promega) and used for DIG-labelled probe synthesis. Mice were deeply anaesthetized with sodium pentobarbital and perfused transcardially with PBS followed by 4% paraformaldehyde (PFA). Forty-micrometre-thick brain sections were treated with 0.3% Triton X-100, digested with 1 μg ml−1 proteinase K, treated with 0.75% glycine, and then treated with 0.25% acetic anhydride in 0.1 M triethanolamine. After overnight incubation with a digoxigenin (DIG)-labelled probe at 60 °C, the sections were washed and then incubated with alkaline phosphatase-conjugated anti-DIG Fab fragments (Roche, 11175041910). The reactions were visualized with a 5-bromo-4-chloro-3-indolyl-phosphate/4-nitroblue tetrazolium (BCIP/NBT) substrate solution (Roche). HEK293 cells (RCB1637) and HEK293T cells (RCB2202) were obtained from the RIKEN BRC Cell Bank. Cells were cultured in DMEM (Wako) supplemented with 10% FBS, 1% GlutaMAX (Thermo Fisher Scientific), and penicillin/streptomycin at 37 °C in a humidified atmosphere of 5% CO . Cell lines were regularly tested for mycoplasma contamination using MycoAlert (Lonza). Cell lines were regularly renewed by obtaining cell stocks from the Cell Bank for authentication. We used HEK293 and HEK293T cells because of their reliable growth, high efficiency in transfection and morphology suitable for electrophysiological experiments. For generating Sik3Slp knock-in mice, a genomic fragment containing exon 13 of the Sik3 gene was isolated from C57BL/6 mouse genomic BAC clone from a RP23 mouse genomic BAC library (Advanced GenoTEchs Co). A 1.7-kb fragment of FRT-PGK-gb2-neo-FRT-loxP cassette (Gene Bridges) flanked by two flippase recognition target (FRT) sites was inserted before exon 12. The targeting vector also contains a G-to-A substitution at the fifth nucleotide from the beginning of intron 13. The targeting vector was linearized and electroporated into the C57BL/6N ES cell line RENKA. Correctly targeted clones were injected into eight-cell stage ICR mouse embryos, which were cultured to produce blastocysts and then transferred to pseudopregnant ICR females. Resulting male chimaeric mice were crossed with female C57BL/6N mice to establish the Sik3Slp-neo/+ line. To remove the neomycin resistance gene with the FLP-FRT system, Sik3Slp-neo/+ mice were crossed with Actb-FLP knock-in mice. The custom-designed ZFN mRNAs targeting the exon 13–intron 13 boundary region of the Sik3 gene were obtained from Sigma-Aldrich’s Composers Custom ZFN service. Before the final assembly of the ZFN products, Sigma-Aldrich validated the designed ZFN binding sequences in silico using their bioinformatics tools and in vitro using Nero2A cell lines, ensuring high cutting efficiency and specificity using mismatch-specific endonuclease CelI according to the manufacturer’s instructions. The ZFN mRNAs were injected into single-cell stage C57BL/6J mouse zygotes at the University of Texas Southwestern Transgenic Core facility. The injected eggs were then transferred to pseudopregnant females to generate F founders. In total, 45 out of 96 F mice were found to be modified at the exon 13–intron 13 boundary region of the Sik3 gene. We crossed one F male mouse that had a 2-bp deletion from the last nucleotide of exon 13 with female C57BL/6N mice to obtain F mice of Sik3Slp/+ ZFN. The F mice were used to confirm the skipping of exon13 in Sik3 mRNA, which was purified from the brains and livers. The F male mice were used for sleep/wakefulness behaviour analysis. To produce a Cas9/single-guide RNA (sgRNA) expression vector, oligonucleotide DNAs (5′-CACCGCGAGCGGCCATCGACCCGC-3′ and 5′-AAACGCGGGTCGATGGCCGCTCGC-3′) were annealed and then inserted into pX330 vector (Addgene). The cleavage activity of the pX330-Sik3Ex1 vector was evaluated by the EGxxFP system38. Genomic DNA containing exon 1 of the Sik3 gene was amplified and inserted into pCAG-EGxxFP to produce pCAG-EGxxFP-Sik3Ex1. The pX330-Sik3Ex1 and pCAG-EGxxFP-Sik3Ex1 were transfected into HEK293 cells. As a donor oligonucleotide, a single-stranded 200-nucleotide DNA was synthesized (Integrated DNA Technologies), which contained a Flag-haemagglutinin-coding sequence in the centre and 70-nucleotide arms at the 5′ and 3′ ends. Female C57BL/6J mice or Sik3Slp knock-in mice were injected with pregnant mare serum gonadotropin and human chorionic gonadotropin at a 48-h interval, and mated with male C57BL/6J mice. The fertilized one-cell embryos were collected from the oviducts. Then, 5 ng μl−1 of pX330-Sik3Ex1 vector and 10 ng μl−1 of the donor oligonucleotide were injected into the pronuclei of these one-cell-stage embryos. The injected one-cell embryos were then transferred into pseudopregnant ICR mice. F mice were genotyped for the presence of Flag-coding sequence in exon1 of the Sik3 gene and for the presence of the Sik3Slp mutation. F mice containing Flag–SIK3 were further examined for the presence of the Cas9 transgene and off-target effects. Candidate off-target sites were identified based on a complete match of 16 bp at the 3′ end, including the PAM sequence. F mice were mated with C57BL/6N mice to obtain F offspring. NalcnDrl mice were produced as described above. To produce the sgRNA expression vector, pX330-NalcnEx9, oligonucleotide DNAs (5′-CACCAGCAATAAACACATTCTGAA-3′ and 5′-AAACTTCAGAATGTGTTTATTGCT-3′) were used. Genomic DNA containing exon 9 of the Nalcn gene was amplified and inserted into pCAG-EGxxFP to produce pCAG-EGxxFP-NalcnEx9. As a donor oligonucleotide, a single-stranded 199-nucleotide DNA containing a T-to-A substitution at the centre was synthesized (Integrated DNA Technologies). Nalcn mutant mice of N –N generation were used for sleep/wakefulness analysis. To evaluate Flag-tagged SIK3 protein in brains, we performed peptide mapping of the purified Flag–SIK3 protein. The brains of Flag-Sik3 knock-in mice and Flag-Sik3Slp knock-in mice were quickly dissected after cervical dislocation. Brains were homogenized in detergent-free buffer and then centrifuged (100,000g, 30 min, 4 °C). The supernatant was immunoprecipitated with anti-DDDDK antibody beads (MBL 3325). The eluate was run on a polyacrylamide gel and stained with SilverQuest Silver staining kit (Life technologies). Flag–SIK3 band (150 kDa) was dissected with a fresh blade. The proteins in the bands were reduced with 10 mM dithiothreitol and alkylated with 40 mM iodoacetamide. Each sample was digested with trypsin (4 μg ml−1; Trypsin Gold, Promega) at 37 °C overnight. The extracted peptides were then separated via nano flow LC (Advance LC, Michrom Bioresources) using a C18 column. The LC eluate was coupled to a nano-ionspray source attached to a Orbitrap Velos Pro mass spectrometer (Thermo Fisher Scientific). All MS/MS spectra were searched using Proteome Discoverer 1.3 software (Thermo Fisher Scientific). Peptides were mapped through mouse SIK3 (NP_081774) with 56% coverage. To examine the effect of sleep deprivation on the phosphorylation status of SIK3 protein, five Flag-Sik3 knock-in mice or five Flag-Sik3Slp knock-in mice were ad libitum slept (S) or sleep-deprived (SD) for 4 h by gentle handling immediately after light onset (ZT0–ZT4). Five wild-type mice were used as a negative control. At ZT4, mouse brains were quickly dissected after cervical dislocation, rinsed with cold PBS, and snap frozen in liquid nitrogen. Each half of the brains was lysed in 2 ml of ice-cold lysis buffer (20 mM HEPES, pH 7.4, 150 mM NaCl, 1 mM EDTA, 1% Triton X-100, 2 mM MgCl , 15 mM NaF, 10 mM Na P O ) freshly supplemented with protease/phosphatase inhibitor cocktail tablets (Roche), and homogenized in a glass tissue homogenizer. After brain homogenate was incubated for 30 min and centrifuged at 13,000g for 20 min at 4 °C, the supernatant was pre-cleared by IgG and Protein G beads for 30 min before immunoprecipitation. Each pre-cleared lysate was added to 50 μl of anti-Flag antibody-conjugated Sepharose beads (Sigma, A2220) and rotated overnight at 4 °C. After washing the beads five times with cold wash buffer (20 mM HEPES, pH 7.4, 150 mM NaCl, 1 mM EDTA, 1% Triton X-100, 2 mM MgCl , 15 mM NaF, 10 mM Na P O ), 50 μl of elution buffer (2% SDS, 60 mM Tris-HCl, pH 6.8, 50 mM DTT, 10% glycerol) was added and rotated for 10 min at 4 °C. Elution was repeated twice and combined into one eluate and analysed by western blotting. For each group of Flag knock-in mice, the five eluates of were mixed and equally split into two or three samples for mass spectrometric analysis. Thus, a total of six (Flag-Sik3) or nine (Flag-Sik3 and Flag-Sik3Slp) samples were reduced, alkylated, and trypsin digested overnight. After desalting, each sample was labelled with a different Tandem Mass Tag (TMT) reagent (Thermo Fisher Scientific), then all samples were combined into one mixture for HPLC fractionation using a C18 column. A total of 12 fractions were collected, and analysed separately on the Orbitrap-Fusion mass spectrometry platform (Thermo Fisher Scientific) using a reverse-phase liquid chromatography tandem mass spectrometry (LC–MS/MS) method. We performed data analysis to identify peptides and quantified reporter ion relative abundance using Proteome Discoverer 2.1 (Thermo Fisher Scientific). The relative abundance of quantified SIK3 phosphorylation sites was normalized with wild-type negative control and total SIK3 protein abundance. To express wild-type NALCN, we used pTracer-CMV2-ratNALCN-EF1α-EGFP (a gift from D. Ren)39. A single nucleotide substitution was induced to make pTracer-CMV2-ratNALCN(DRL)-EF1α-EGFP using a KOD plus Mutagenesis kit (Toyobo). HEK293T cells were grown to ~50% confluency in 12-well plates. Using Lipofectamine LTX (2 μl) and PLUS (1 μl) reagents (Thermo Fisher Scientific), the cells were cotransfected with 0.3 μg of each plasmid DNA encoding rat NALCN-EGFP (wild type or DRL), mouse UNC-80, and mouse SRC (Y529F) (constitutively active Src) in 12-well plates. UNC-80 and SRC kinase activate NALCN27, 28. In some experiments, the cells were incubated with 10 μM Gd3+ to inhibit NALCN. The cells were dissociated and plated on 18-mm coverslips coated with poly-l-lysine in fresh culture medium before patch-clamp recordings. All patch-clamp recordings from HEK293T cells were performed >72 h after transfection. Recording patch pipettes were pulled from glass capillaries (1B150F-4, World Precision Instruments) using a micropipette puller (P-97, Sutter Instrument) to give a resistance of ~9 MΩ. The series resistance of whole-cell recordings was ~40 MΩ, which was not compensated. Patch pipettes were filled with solution containing 150 mM CsOH, 120 mM methanesulfonic acid, 10 mM NaCl, 10 mM EGTA, 2 mM Mg ATP and 10 mM HEPES (pH 7.4 adjusted with methanesulfonic acid; osmolarity, 290−299 mOsm l−1 adjusted with CsCl). The cells on coverslips were transferred to a recording chamber under a fluorescence upright microscope (Axio Examiner D1, Zeiss) and continuously perfused with the bath solutions containing 150 mM NaCl, 3.5 mM KCl, 10 mM HEPES, 20 mM glucose, 5 mM NaOH, 2 mM MgCl and 1.2 mM CaCl (pH 7.4 adjusted; osmolarity, 300−310 mOsm l−1). The transfected cells were identified by enhance green fluorescent protein (eGFP) fluorescence. Patch-clamp recordings were performed at room temperature (24 °C) using a computer-controlled amplifier (MultiClamp 700B, Molecular Devices). The signals were digitized with A/D converter (Digidata 1440A, Molecular Devices), and acquired with Clampex (Molecular Devices) at a sampling rate of 50 kHz, and low-pass filtered at 5 kHz. At the end of recording, Gd3+ (10 μM) was used to confirm that the whole-cell currents were mediated through NALCN39. Data were analysed using Clampfit (Molecular Devices). The equilibrium potentials were calculated from I–V curves. Mean membrane conductance was estimated from the regression lines fitted to I–V curves from individual cells. Current, membrane conductance and charge transfer were normalized to membrane capacitance. Patch pipettes and recording system were the same as those used in recordings from HEK293 cells. Acute brain slices containing the DpMe were prepared from post-natal day 12–23 Nalcn+/+ or NalcnDrl/+ mice. After the induction of deep anaesthesia with isoflurane, mice were decapitated and the brains were rapidly removed into an ice-cold cutting solution containing 2.5 mM KCl, 1.25 mM NaH PO , 26 mM NaHCO , 25 mM glucose, 185 mM sucrose, 0.5 mM CaCl and 10 mM MgCl (pH 7.4, when bubbled with 95% O and 5% CO ). The brains were cut coronally into 200–250 μm-thick slices with a vibratome (VT-1200S, Leica). The slices were incubated at 37 °C for 1 h in artificial cerebrospinal fluid (aCSF) containing 125 mM NaCl, 2.5 mM KCl, 1.25 mM NaH PO , 26 mM NaHCO , 10 mM glucose, 2 mM CaCl and 1 mM MgCl (pH 7.4, when bubbled with 95% O and 5% CO ) before recordings. Slices were transferred to a recording chamber perfused with aCSF under an upright microscope (Axio Examiner D1, Zeiss). Patch pipettes were filled with solution containing 125 mM K-gluconate, 10 mM KCl, 10 mM HEPES, 0.5 mM EGTA, 8 mM phosphocreatine-Na , 4 mM ATP-Mg and 0.3 mM GTP-Na (pH 7.3 adjusted with KOH; osmolality, 290 mOsm l−1). The DpMe was identified with axon bundles. Recordings were made from cells located in the medial part of the DpMe. Cells showing no action potentials following current injection (>1 nA, > 5 ms) were discarded from analysis. Membrane potentials were recorded for 1–10 min. Sik3 hypomorph and UAS-Sik3, UAS-Sik3(S563A) transgenic flies were gifts from M. Montminy and J. B. Thomas40. elav-GS (GeneSwitch) stocks were from the Bloomington stock centre. Flies were reared at 25 °C under 12-h light:12-h dark cycle in 50–60% relative humidity on a standard fly food consisting of corn meal, yeast, glucose, wheat germ and agar. Sleep analysis was performed as described previously41. In brief, male flies (2–5 days old) were individually housed in glass tubes (length, 65 mm; inside diameter, 3 mm) containing standard fly food at one end and a cotton plug on the other end. Sucrose-agar (1% agar supplemented with 5% sucrose) food was used for the GeneSwitch system assay, instead of standard food. The glass tubes were placed in the Drosophila activity monitor (DAM) (Trikinetics) and the locomotor activity of each fly was recorded as the number of infrared beam crossings in 1-min bin. Sleep was defined as periods of inactivity lasting 5 min or longer. Sleep assay were performed for 3 d under 12-h light:12-h dark cycle conditions and then constant darkness conditions. For 12-h light:12-h dark cyles, zeitgeber time (ZT) was used, and for constant darkness, circadian time (CT), with CT0 as 12 h after lights-off of the last 12-h light:12-h dark conditions, was used to indicate the daily time. For conditional expression analysis, we used the GeneSwitch system42 where expression is induced by a steroid hormone antagonist RU486. Flies are monitored for 3 days in tubes without drug in constant darkness and then transferred to new tubes either with vehicle (0.5% DMSO) alone or with 0.5 mM RU486 and then further monitored under constant darkness conditions. The expression of endogenous or transgenic Sik3 genes was confirmed by RT–PCR using RNA from fly heads. The wild-type strain N and the mutant strain PY1479 kin-29(oy38) X were obtained from the Caenorhabditis Genetics Center (CGC)43. All worms were maintained at 20 °C on nematode growth medium (NGM) agar plates seeded with E. coli HB101. For construction of P ::kin-29, kin-29 cDNA was amplified by RT–PCR and inserted into the plasmid pPD-DEST (a gift from Y. Iino) to generate pDEST-KIN-29. Next, we carried out the LR-recombinase reaction (Gateway System, Life Technologies) between pENTR-P (a gift from Y. Iino) and pDEST-KIN-29 to generate P ::kin-29. P ::kin-29 was injected at 30 ng μl−1 together with the injection marker P ::mcherry (10 ng μl−1) and the empty vector pPD49_26 (60 ng μl−1) into the kin-29(oy38) mutant worms. Quiescence during the L4 to adult lethargus was measured using the microfluidic-chamber based assay44. In brief, polydimethylsiloxane-made microfluidic chambers containing liquid NGM and the E. coli HB101 were loaded with early L4 larvae and sealed with a cover glass plus 2% agarose, and set under the microscope. Images were taken every 2 s for 12 to 20 h at 20 ± 0.5 °C using the microscope M205FA (Leica) equipped with the camera MC120HD (Leica) (pixel size: 1,024 μm × 768 μm) controlled by Leica Application Suite V4.3 or the microscope SZX16 (Olympus) equipped with the camera GR500BCM2 (Shodensha) (pixel size: 1,024 μm × 768 μm) controlled by μManager (UCSF). Subtraction between serial images was carried out using Image J, and worms were regarded as quiescent at a specific time point if the difference from the preceding time point was less than 1% of the total body size. The fraction of quiescence was defined as the number of quiescent time points divided by the total number of time points during a period of 10 min. The onset of lethargus quiescence was defined as the time point after which the fraction of quiescence was higher than 0.05 for at least 20 min, whereas the end point was defined as the time point after which the fraction of quiescence was lower than 0.05 for at least 20 min. Occasionally, brief episodes of quiescence were observed outside of lethargus both in wild-type and mutant worms; these episodes were excluded by setting a threshold of 60 min for the minimum duration of lethargus quiescence. Sample sizes were determined using R software based on averages and standard deviations that were obtained from small scale experiments. No method of randomization was used in any of the experiments. The experimenters were blinded to genotypes and treatment assignment. Statistical analysis was performed using SPSS Statistics 22 (IBM) and R software. All data were tested for Gaussian distribution and variance. Homogeneity of variances was tested with Levene’s test. We used Student’s t-test for pairwise comparisons, one-way ANOVA for multiple comparisons, one-way repeated measure ANOVA for multiple comparisons with multiple data points, and two-way ANOVA for multiple comparisons involving two independent variables. ANOVA analyses were subjected to Tukey’s post-hoc test. When deviation from normality and lack of homogeneity of variances occurred (P < 0.05), Mann–Whitney U test was used for group comparison. P < 0.05 was considered statistically significant. The datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request.


Cuneo B.F.,University of Colorado at Denver | Strasburger J.F.,Medical College of Wisconsin | Yu S.,University of Wisconsin - Madison | Horigome H.,University of Tsukuba | And 3 more authors.
Circulation | Year: 2013

BACKGROUND -: The electrophysiology of long QT syndrome (LQTS) in utero is virtually unstudied. Our goal here was to evaluate the efficacy of fetal magnetocardiography (fMCG) for diagnosis and prognosis of fetuses at risk of LQTS. METHODS AND RESULTS -: We reviewed the pre/postnatal medical records of 30 fetuses referred for fMCG because of a family history of LQTS (n=17); neonatal/childhood sudden cardiac death (n=3), or presentation of prenatal LQTS rhythms (n=12): 2 atrioventricular block, ventricular tachycardia, heart rate < 3 percentile. We evaluated heart rate and reactivity, cardiac time intervals, T-wave characteristics, and initiation/termination of Torsade de Pointes, and compared these with neonatal ECG findings. After birth, subjects were tested for LQTS mutations. Based on accepted clinical criteria, 21 subjects (70%; 9 KCNQ1, 5 KCNH2, 2 SCN5A, 2 other, 3 untested) had LQTS. Using a threshold of corrected QT= 490 ms, fMCG accurately identified LQTS fetuses with 89% (24/27) sensitivity and 89% (8/9) specificity in 36 sessions. Four fetuses (2 KCNH2 and 2 SCN5A), all with corrected QT ≥ 620 ms, had frequent episodes of Torsade de Pointes, which were present 22-79% of the time. Although some episodes initiated with a long-short sequence, most initiations showed QRS aberrancy and a notable lack of pause dependency. T-wave alternans was strongly associated with severe LQTS phenotype. CONCLUSIONS -: Corrected QT prolongation (≥490 ms) assessed by fMCG accurately identified LQTS in utero; extreme corrected QT prolongation (≥620 ms) predicted Torsade de Pointes. FMCG can play a critical role in the diagnosis and management of fetuses at risk of LQTS. © 2013 American Heart Association, Inc.


Castelletto S.,RMIT University | Johnson B.C.,University of Melbourne | Johnson B.C.,Japan Atomic Energy Agency | Ivady V.,Hungarian Academy of Sciences | And 6 more authors.
Nature Materials | Year: 2014

Over the past few years, single-photon generation has been realized in numerous systems: single molecules, quantum dots, diamond colour centres and others. The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics and measurement theory. An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite-vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×10 6 counts s -1) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices. © 2014 Macmillan Publishers Limited. All rights reserved.


Nakahara S.,Kanagawa University of Human Services | Tomio J.,University of Tokyo | Ichikawa M.,University of Tsukuba | Nakamura F.,University of Tokyo | And 4 more authors.
JAMA - Journal of the American Medical Association | Year: 2015

Importance Neurologically intact survival after out-of-hospital cardiac arrest (OHCA) has been increasing in Japan. However, associations between increased prehospital care, including bystander Interventions and increases in survival, have not been well estimated. Objective To estimate the associations between bystander Interventions and changes in neurologically intact survival among patients with OHCA in Japan. Design, Setting, and Participants Retrospective descriptive study using data from Japan's nationwide OHCA registry, which started in January 2005. The registry includes all patients with OHCA transported to the hospital by emergency medical services (EMS) and recorded patients' characteristics, prehospital Interventions, and Outcomes. Participants were 167 912 patients with bystander-witnessed OHCA of presumed cardiac origin in the registry between January 2005 and December 2012. EXPOSURES Prehospital Interventions by bystander, including defibrillation using public-access automated external defibrillators and chest compression. Main Outcomes and Measures Neurologically intact survivalwas defined as Glasgow-Pittsburgh cerebral performance category score 1 or 2 and overall performance category scores 1 or 2 at 1 month or at discharge. The association between the Interventions and neurologically intact survival was evaluated. RESULTS From 2005 to 2012, the number of bystander-witnessed OHCAs of presumed cardiac origin increased from 17 882 (14.0 per 100 000 persons [95%CI, 13.8-14.2]) to 23 797 (18.7 per 100 000 persons [95%CI, 18.4-18.9]), and neurologically intact survival increased from 587 cases (age-adjusted proportion, 3.3%[95%CI, 3.0%-3.5%]) to 1710 cases (8.2%[95%CI, 7.8%-8.6%]). The rates of bystander chest compression increased from 38.6%to 50.9%, bystander-only defibrillation increased from 0.1% to 2.3%, bystander defibrillation combined with EMS defibrillation increased from 0.1% to 1.4%, and EMS-only defibrillation decreased from 26.6%to 23.5%. Performance of bystander chest compression, compared with no bystander chest compression, was associated with increased neurologically intact survival (8.4%[6594 survivors/78 592 cases] vs 4.1% [3595 survivors/88 720 cases]; odds ratio [OR], 1.52 [95%CI, 1.45-1.60]). Compared with EMS-only defibrillation (15.0%[6445 survivors/42 916 cases]), bystander-only defibrillation (40.7% [931 survivors/2287 cases]) was associated with increased neurologically intact survival (OR, 2.24 [95%CI, 1.93-2.61]), as was combined bystander and EMS defibrillation (30.5%[444 survivors/1456 cases]; OR, 1.50 [95%CI, 1.31-1.71]), whereas no defibrillation (2.0% [2369 survivors/120 653 cases]) was associated with reduced survival (OR, 0.43 [95%CI, 0.39-0.48]). Conclusions and Relevance In Japan, between 2005 and 2012, the rates of bystander chest compression and bystander defibrillation increased and were associated with increased odds of neurologically intact survival. © 2015 American Medical Association. All rights reserved.


Inoue N.,University of Tsukuba | Takai E.,University of Tsukuba | Arakawa T.,Alliance Protein Laboratories | Shiraki K.,University of Tsukuba
Molecular Pharmaceutics | Year: 2014

Unacceptably high viscosity is observed in high protein concentration formulations due to extremely large therapeutic dose of antibodies and volume restriction of subcutaneous route of administration. Here, we show that a protein aggregation suppressor, arginine hydrochloride (ArgHCl), specifically decreases viscosity of antibody formulations. The viscosities of bovine gamma globulin (BGG) solution at 250 mg/mL and human gamma globulin (HGG) solution at 292 mg/mL at a physiological pH were too high for subcutaneous injections, but decreased to an acceptable level (below 50 cP) in the presence of 1,000 mM ArgHCl. ArgHCl also decreased the viscosity of BGG solution at acidic and alkaline pHs. Interestingly, ArgHCl decreased the viscosity of antibody solutions (BGG, HGG, and human immunoglobulin G) but not globular protein solutions (α-amylase and α-chymotrypsin). These results indicate not only high potency of ArgHCl as an excipient to decrease the solution viscosity of high concentration antibodies formulations but also specific interactions between ArgHCl and antibodies. © 2014 American Chemical Society.


Yoo C.Y.,Purdue University | Pence H.E.,Purdue University | Jin J.B.,CAS Institute of Botany | Miura K.,University of Tsukuba | And 3 more authors.
Plant Cell | Year: 2010

A goal of modern agriculture is to improve plant drought tolerance and production per amount of water used, referred to as water use efficiency (WUE). Although stomatal density has been linked to WUE, the causal molecular mechanisms have yet to be determined. Arabidopsis thaliana GT-2 LIKE 1 (GTL1) loss-of-function mutations result in increased water deficit tolerance and higher integrated WUE by reducing daytime transpiration without a demonstrable reduction in biomass accumulation. gtl1 plants had higher instantaneous WUE that was attributable to ~25% lower transpiration and stomatal conductance but equivalent CO2 assimilation. Lower transpiration was associated with higher STOMATAL DENSITY AND DISTRIBUTION1 (SDD1) expression and an ~25% reduction in abaxial stomatal density. GTL1 expression occurred in abaxial epidermal cells where the protein was localized to the nucleus, and its expression was downregulated by water stress. Chromatin immunoprecipitation analysis indicated that GTL1 interacts with a region of the SDD1 promoter that contains a GT3 box. An electrophoretic mobility shift assay was used to determine that the GT3 box is necessary for the interaction between GTL1 and the SDD1 promoter. These results establish that GTL1 negatively regulates WUE by modulating stomatal density via transrepression of SDD1. © 2010 American Society of Plant Biologists.


Takeshita N.,Karlsruhe Institute of Technology | Takeshita N.,University of Tsukuba | Manck R.,Karlsruhe Institute of Technology | Grun N.,Karlsruhe Institute of Technology | And 2 more authors.
Current Opinion in Microbiology | Year: 2014

Cell polarization is a theme in biology conserved from bacteria to man. One of the most extremely polarized cells in nature is the hyphae of filamentous fungi. A continuous flow of secretion vesicles from the hyphal cell body to the tip is essential for cell wall and membrane extension. Microtubules (MTs) and actin, along with their corresponding motor proteins, are involved in the secretion process. Therefore, the arrangement of the cytoskeleton is a crucial step to establish and maintain polarity. Here we review recent findings unraveling the mechanism of polarized growth with special emphasis on the role of the actin and MT cytoskeletons and cell end markers linking the two cytoskeletons. We will mainly focus on Neurospora crassa and Aspergillus nidulans as model organisms. © 2014 Elsevier Ltd.


Isozaki H.,University of Tsukuba | Korotyaev E.,Saint Petersburg State University
Annales Henri Poincare | Year: 2012

We study discrete Schrödinger operators with compactly supported potentials on Z d. Constructing spectral representations and representing S-matrices by the generalized eigenfunctions, we show that the potential is uniquely reconstructed from the S-matrix of all energies. We also study the spectral shift function ξ(λ) for the trace class potentials, and estimate the discrete spectrum in terms of the moments of ξ(λ) and the potential. © 2011 Springer Basel AG.


Lu X.,Huazhong University of Science and Technology | Lu X.,University of Tsukuba | Akasaka T.,Huazhong University of Science and Technology | Akasaka T.,University of Tsukuba | And 2 more authors.
Accounts of Chemical Research | Year: 2013

Endohedral metallofullerenes (EMFs) are hybrid molecules with different metallic species encapsulated inside the fullerene cages. In addition to conventional EMFs that contain only metal ions, researchers have constructed novel compounds that encapsulate metallic clusters of nitride, carbide, oxide, cyanide, and sulfide. Among these structures, carbide cluster metallofullerenes (CCMFs) are unique because their synthesis requires only graphite and the metal source. As a result the molecular structures of CCMFs are particularly difficult to characterize. Two carbon atoms are encapsulated inside the cage, but they do not participate in constructing the cage framework. Recent X-ray crystallographic studies of EMFs have allowed researchers to unambiguously identify CCMFs (MxC2@C2n). Previously most of these structures had been described as conventional EMFs Mx@C 2n+2. Most of these species are scandium-containing compounds such as Sc3C2@Ih(7)-C80 [not Sc 3@C3v(7)-C82], Sc2C 2@C2v(5)-C80 [not Sc2@C 82], Sc2C2@Cs(6)-C82 [not Sc2@Cs(10)-C84], Sc2C 2@C2v(9)-C82 [not Sc2@C 2v(17)-C84], Sc2C2@C 3v(8)-C82 [not Sc2@D2d(23)-C 84], and Sc2C2@D2d(23)-C 84 [not Sc2@C86]. Additional examples of CCMFs include Gd2C2@D3(85)-C92, Sc 2C2@C2v(6073)-C68, Ti 2C2@D3h(5)-C78, M2C 2@C3v(8)-C82, M2C2@C s(6)-C82 (M = Y, Er, etc.), Y2C 2@C84, Y2C2@D3(85)-C 92, Y2C2@D5(450)-C100, and Lu3C2@D2(35)-C88. The existence of so many CCMF species reminds us that the symbol '@' (which denotes the encapsulation status of EMFs) should be used with caution with species whose molecular structures have not been determined unambiguously.This Account presents a detailed summary of all aspects of CCMFs, including historically erroneous assignments and corrected structural characterizations, along with their intrinsic properties such as electrochemical and chemical properties. We emphasize structural issues, features that are fundamental for understanding their intrinsic properties. Finally, we discuss the formation mechanism and possible origin of cluster EMFs, not just CCMFs. © 2013 American Chemical Society.


Patent
University of Tsukuba and Daico Manufacturing Co. | Date: 2015-04-29

A fluoride sintered body suitable for a moderator which moderates high-energy neutrons so as to generate neutrons for medical care with which an affected part of the deep part of the body is irradiated to make a tumor extinct comprises MgF_(2) of a compact polycrystalline structure having a bulk density of 2.90g/cm^(3) or more and as regards mechanical strengths, a bending strength of 10MPa or more and a Vickers hardness of 71 or more.


Patent
University of Tsukuba, Techno Eye Corporation and Daico Manufacturing Co. | Date: 2016-03-30

A MgF_(2)-CaF_(2) binary system sintered body for a radiation moderator having a compact polycrystalline structure excellent in radiation moderation performance, especially neutron moderation performance, comprises MgF_(2) containing CaF_(2) from 0.2% by weight to 90% by weight inclusive, having a bulk density of 2.96g/cm^(3) or more, and a bending strength of 15MPa or more and a Vickers hardness of 90 or more as regards mechanical strengths.


Patent
University of Tsukuba, Techno Eye Corporation and DAICO Manufacturing CO. | Date: 2015-04-13

A MgF_(2)-CaF_(2 )binary system sintered body for a radiation moderator having a compact polycrystalline structure excellent in radiation moderation performance, especially neutron moderation performance, comprises MgF_(2 )containing CaF_(2 )from 0.2% by weight to 90% by weight inclusive, having a bulk density of 2.96 g/cm^(3 )or more, and a bending strength of 15 MPa or more and a Vickers hardness of 90 or more as regards mechanical strengths.


Patent
University of Tsukuba and DAICO Manufacturing CO. | Date: 2014-05-27

A fluoride sintered body suitable for a moderator which moderates high-energy neutrons so as to generate neutrons for medical care with which an affected part of the deep part of the body is irradiated to make a tumor extinct comprises MgF_(2 )of a compact polycrystalline structure having a bulk density of 2.90 g/cm^(3 )or more and as regards mechanical strengths, a bending strength of 10 MPa or more and a Vickers hardness of 71 or more.


Patent
University of Tsukuba, Techno Eye Corporation and Daico Manufacturing Co. | Date: 2016-08-24

A MgF_(2) system fluoride sintered body for a radiation moderator having a compact polycrystalline structure excellent in radiation moderation performance, especially neutron moderation performance, contains CaF_(2) of 90% by weight at the maximum and has a relative density of 95.2% or more.


Patent
University of Tsukuba, Techno Eye Corporation and DAICO Manufacturing CO. | Date: 2015-12-18

A MgF_(2 )system fluoride sintered body for a radiation moderator having a compact polycrystalline structure excellent in radiation moderation performance, especially neutron moderation performance, contains CaF_(2 )of 90% by weight at the maximum and has a relative density of 95.2% or more.


Cells are not uniform spheres; they generally come in a variety of disparate shapes. In the broadest sense, this variation in shapes is known as cell polarity, and it is an essential property for a variety of cell functions. Growth in accordance with their polarity allows cells to shape themselves in forms appropriate to their function. It has been found that the establishment and maintenance of polarity is governed by the interdependent relationship between the polarity marker protein on the plasma membrane (cell membrane), actin, the microtubule cytoskeleton, and membrane vesicle transport. The polarity marker determines the polarity site, and with membrane vesicle transport toward it, site-specific growth (polarity growth) is achieved. However, when the plasma membrane elongates due to fusion of membrane vesicles, there have been questions about how polarity markers are maintained without being scattered over the elongated plasma membrane. A research group lead by University of Tsukuba Faculty of Life and Environmental Sciences International Tenure Track Assistant Professor Norio Takeshita (who holds a concurrent post as Group Leader of the Karlsruhe Institute of Technology Department of Applied Microbiology) has succeeded in using a super-resolution microscope to visualize the mechanism by which cell polarity is maintained. Professor Takeshita's study used a super-resolution microscope to clarify the behavior of polarity markers that could not be visualized with conventional fluorescence microscopes. The study employed a fluorescence microscope with super-resolution capability to image a fungal model with a filamentous shape and visualize the behavior of polarity markers, clarifying their relationship to exocytosis (the fusion of a membrane vesicle to a plasma membrane) and microtubules. More information: Y. Ishitsuka et al. Superresolution microscopy reveals a dynamic picture of cell polarity maintenance during directional growth, Science Advances (2015). DOI: 10.1126/sciadv.1500947


Hoshino N.,University of Tsukuba | Iijima F.,University of Tsukuba | Newton G.N.,University of Tsukuba | Yoshida N.,University of Tsukuba | And 6 more authors.
Nature Chemistry | Year: 2012

Bistable compounds that exist in two interchangeable phases under identical conditions can act as switches under external stimuli. Among such switchable materials, coordination complexes have energy levels (or phases) that are determined by the electronic states of their constituent metal ions and ligands. They can exhibit multiple bistabilities and hold promise in the search for multifaceted materials that display different properties in different phases, accessible through the application of contrasting external stimuli. Molecular systems that exhibit both thermo- and photoinduced magnetic bistabilities are excellent candidates for such systems. Here we describe a cyanide-bridged [CoFe] one-dimensional chiral coordination polymer that displays both magnetic and electric bistabilities in the same temperature range. Both the electric and magnetic switching probably arise from the same electron-transfer coupled spin-transition phenomenon, which enables the reversible conversion between an insulating diamagnetic phase and either a semiconducting paramagnetic (thermoinduced) or a type of ferromagnetic single-chain magnet (photoinduced) state. © 2012 Macmillan Publishers Limited. All rights reserved.


Chen K.,Tohoku University | Mori K.,Tohoku University | Watanabe H.,University of Tsukuba | Nakagawa Y.,Tohoku University | Tomishige K.,Tohoku University
Journal of Catalysis | Year: 2012

Hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol and other related substrates such as 3-hydroxytetrahydrofuran and 1,2-cyclohexanediol proceeds over Ir-ReO x/SiO 2 catalyst. TOF values are higher than those of Rh-ReO x/SiO 2, which has been reported to be an effective catalyst. The selectivity to the product, where the C-O bond neighboring the C-OH group in the substrate is dissociated, is comparable to or higher than that of Rh-ReO x/SiO 2. Hydrogenolysis of most substrates except 1,2-cyclohexanediol proceeds via the direct mechanism where hydride species formed from hydrogen molecule attacks the anti-position of C-O bond. In the case of hydrogenolysis of 1,2-cyclohexanediol where attack of anti-position of C-O bond is unfavorable, indirect mechanism involving dehydrogenation to 2-hydroxycyclohexanone is responsible for the formation of cyclohexanol. © 2012 Elsevier Inc. All rights reserved.


Someya T.,University of Tsukuba | Baba S.,Japan Synchrotron Radiation Research Institute | Fujimoto M.,University of Tsukuba | Kawai G.,Chiba Institute of Technology | And 3 more authors.
Nucleic Acids Research | Year: 2012

Bacterial Hfq is a protein that plays an important role in the regulation of genes in cooperation with sRNAs. Escherichia coli Hfq (EcHfq) has two or more sites that bind RNA(s) including U-rich and/or the poly(A) tail of mRNA. However, functional and structural information about Bacillus subtilis Hfq (BsHfq) including the RNA sequences that specifically bind to it remain unknown. Here, we describe RNA aptamers including fragment (AG)3A that are recognized by BsHfq and crystal structures of the BsHfq-(AG) 3A complex at 2.2 Å resolution. Mutational and structural studies revealed that the RNA fragment binds to the distal site, one of the two binding sites on Hfq, and identified amino acid residues that are critical for sequence-specific interactions between BsHfq and (AG) 3A. In particular, R32 appears to interact with G bases in (AG)3A. Poly(A) also binds to the distal site of EcHfq, but the overall RNA structure and protein-RNA interaction patterns engaged in the R32 residues of BsHfq-(AG)3A differ from those of EcHfq-poly(A). These findings provide novel insight into how the Hfq homologue recognizes RNA. © 2012 The Author(s).


Matsuda T.,University of Tsukuba | Kim J.,Japan Synchrotron Radiation Research Institute | Moritomo Y.,University of Tsukuba
Journal of the American Chemical Society | Year: 2010

We observed a reversible symmetry switch of a cobalt ferrocyanide framework by the alkaline cation exchange and resultant control of the optical properties at room temperature. © 2010 American Chemical Society.


Nakagawa Y.,University of Tsukuba | Shinmi Y.,University of Tsukuba | Koso S.,University of Tsukuba | Tomishige K.,University of Tsukuba | Tomishige K.,Tohoku University
Journal of Catalysis | Year: 2010

Rhenium-oxide-modified supported iridium nanoparticles on silica catalyzes direct hydrogenolysis of glycerol to 1,3-propanediol in an aqueous media. The selectivity to 1,3-propanediol at an initial stage reaches 67 ± 3%. The yield of 1,3-propanediol reaches 38% at 81% conversion of glycerol. The characterization of catalyst and the reactivity of alcohols suggest that 1,3-propanediol is produced by the attack of active hydrogen species on iridium metal to 1-glyceride species formed on the oxidized rhenium cluster. © 2010 Elsevier Inc.


Hatta Y.,University of Tsukuba | Nishiyama A.,Kyoto Sangyo University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

Motivated by the problem of thermalization in heavy ion collisions, we present numerical simulations of the nonequilibrium evolution of the O(N) model in 1+2 dimensions with longitudinal expansion and in the presence of a background field. We work in the next-to-leading-order approximation of the 1/N expansion and consider both the strong and weak coupling cases. Special emphasis is put on the difference between the two-particle irreducible formalism and the classical statistical approach. In the two-particle irreducible case at strong coupling, we find some evidence of the Bose-Einstein (exponential) distribution in the expanding system. © 2012 American Physical Society.


Kaneuchi T.,Tokyo Metroplitan University | Sartain C.V.,Cornell University | Takeo S.,University of Tsukuba | Horner V.L.,Cornell University | And 3 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

Egg activation is the process by which a mature oocyte becomes capable of supporting embryo development. In vertebrates and echinoderms, activation is induced by fertilization. Molecules introduced into the egg by the sperm trigger progressive release of intracellular calcium stores in the oocyte. Calcium wave(s) spread through the oocyte and induce completion of meiosis, new macromolecular synthesis, and modification of the vitelline envelope to prevent polyspermy. However, arthropod eggs activate without fertilization: in the insects examined, eggs activate as they move through the female's reproductive tract. Here, we show that a calcium wave is, nevertheless, characteristic of egg activation in Drosophila. This calcium rise requires influx of calcium from the external environment and is induced as the egg is ovulated. Pressure on the oocyte (or swelling by the oocyte) can induce a calcium rise through the action of mechanosensitive ion channels. Visualization of calcium fluxes in activating eggs in oviducts shows a wave of increased calcium initiating at one or both oocyte poles and spreading across the oocyte. In vitro, waves also spread inward from oocyte pole(s). Wave propagation requires the IP3 system. Thus, although a fertilizing sperm is not necessary for egg activation in Drosophila, the characteristic of increased cytosolic calcium levels spreading through the egg is conserved. Because many downstream signaling effectors are conserved in Drosophila, this system offers the unique perspective of egg activation events due solely to maternal components.


Kino M.,Japan National Astronomical Observatory | Kawakatu N.,University of Tsukuba | Takahara F.,Osaka University
Astrophysical Journal | Year: 2012

We examine plasma composition of jets in active galactic nuclei through the comparison of the total pressure (P) with partial pressures of electrons and protons in a cocoon. The total pressure is estimated from the analysis of expanding cocoon dynamics. We determine the average kinetic energy per particle for several representative cases of particle energy distribution such as one- and two-temperature thermal plasmas and non-thermal electrons by evaluating the dissipation of the total kinetic energy of the jet into the internal energy of cocoon plasma. The number density of the total electrons/positrons ( n) in the cocoon is constrained by using the particle supply from hot spots and the absence of thermal bremsstrahlung emission from radio lobes. By inserting P, n, and the particle energy of each population into the equation of state, the number density (np ) and pressure (Pp ) of protons in the cocoon can be constrained. Applying this method to Cygnus A, we find that (1) electron/positron (e ±) pairs always dominate in terms of number density, but that (2) either an "e ±- supported cocoon (i.e., P p > Pp )" or a "proton-supported one (i.e., P p < Pp )" is possible. © 2012. The American Astronomical Society. All rights reserved.


Barbana C.,University of Zaragoza | El-Omri A.,University of Tsukuba
Food and Bioprocess Technology | Year: 2012

The rheological properties of tomato concentrates produced by hot and cold break have been extensively studied by many authors. Only a few studies, however, focus specifically with the rheology of reconstituted concentrates from tomato powders. In this study, the rheological properties of reconstituted tomato concentrate from lyophilized freeze-dried tomato juice were evaluated using rotational viscometer at temperatures 20 °C, 30 °C, 40 °C, 50 °C, and 60 °C and at concentrations of 9. 7%, 12. 9%, 20. 5%, and 26. 8% total soluble solids. Using power law model, both flow behavior index (n) and consistency coefficient (k) were determined. The calculated values of flow behavior index (n) were less than unity (0. 03-0. 28) at all temperatures and concentrations indicating the shear-thinning characteristic of the concentrate. The effect of temperature and concentration on the consistency coefficient (k) was studied. Positive correlation between k in the range of 1. 57 and 38. 33 Pa s n and inverse absolute temperature (1/T) has been shown by Arrhenius model. Additionally, linear correlation between consistency coefficient (k) and concentration (C) was determined. The activation energies were found in the range of 3. 63 and 7. 36 kJ/mol K depending on concentration. The results of this study might be useful to improve the design of processing operations dealing with tomato powder reconstitution. © 2009 Springer Science + Business Media, LLC.


Koso S.,Tohoku University | Watanabe H.,University of Tsukuba | Okumura K.,Tottori University | Nakagawa Y.,Tohoku University | Tomishige K.,Tohoku University
Applied Catalysis B: Environmental | Year: 2012

Rh-MO x/SiO 2 (M=Mo or Re) catalysts shows the high activity of the hydrogenolysis of C-O bond in the substrates with CH 2OH group such as tetrahydrofurfuryl alcohol, various diols and their ethers. Characterization results suggest the catalyst structure were isolated MoO x species and small ReO x cluster with low valence attached on the surface of Rh metal particles. It is characteristic that the reactivity of the C-O bond in the -O-C-C-CH 2OH is higher than that in the -O-C-CH 2OH over Rh-MoO x/SiO 2, and Rh-ReO x/SiO 2 has the opposite tendency to Rh-MoO x/SiO 2. The difference in the regioselectivity of the hydrogenolysis over Rh-MoO x/SiO 2 and Rh-ReO x/SiO 2 can be related to the different structure of isolated MoO x species and small ReO x clusters. © 2011 Elsevier B.V.


Newton R.C.,University of California at Los Angeles | Tsunogae T.,University of Tsukuba | Tsunogae T.,University of Johannesburg
Precambrian Research | Year: 2014

Fifty years after the discovery of incipient charnockite (orthopyroxene-bearing granitic rocks) partially replacing amphibole-biotite gneiss in southern India, this phenomenon has been found in transitional amphibolite facies to granulite facies terrains on every continent, and may be a characteristic feature of progressive deep-crustal metamorphism. The alteration is essentially a metasomatic transformation. Mass balance calculations for localities in southern India and Sri Lanka for which analytic data are most comprehensive show that the main reaction producing orthopyroxene in orthogneiss is breakdown of hornblende by reaction with biotite, with loss of FeO, MgO, TiO2, and CaO, as well as H2O from the host rock. There is concomitant gain of SiO2. No significant change of alkalis can be demonstrated as essential to the transformation, though advanced charnockitic alteration at the type locality of Kabbal, Karnataka may also show large increase of K2O, with removal of mafic constituents.Very similar orthopyroxene-bearing veins in garnet-biotite gneiss at the Ponmudi type locality in Kerala show definite, but more subtle metasomatism, with loss of FeO and MgO and increase of SiO2 and alkalis. Both the Kabbal and Ponmudi alterations occurred at mid-crustal levels: 5-6kbar and 700-750°C.It is postulated that both types of charnockitic alteration may have been produced as open-system processes by much the same kind of metasomatizing fluids - nearly coeval CO2-rich and ultrasaline fluids, based on fluid inclusion evidence. The paragneiss alteration is mainly biotite breakdown with some involvement of garnet, and leads to a distinct metamorphic facies type. The presence of graphite in some of the garnet-biotite gneisses at Ponmudi would have resulted in lower oxygen fugacity and, probably, lower H2O activity than in the similar Kabbal-type metamorphism. The fluid/rock ratios for both types were small (about 10 mass percent of the rocks), and the fluids, whatever their origin, were largely rock-governed.The source of the metasomatizing fluids has not been definitely identified. Carbon isotopes of fluid inclusions seem to show an igneous or primitive mantle source at both type localities, but ultrasaline fluids may be more plausibly explained by metasedimentary sources, and calcareous metasediments have been identified as a source of CO2 in some occurrences. Much remains to be learned about incipient charnockite and its significance in processes of crustal evolution. © 2014 Elsevier B.V.


Zhang W.-X.,Tohoku University | Shiga T.,University of Tsukuba | Miyasaka H.,Kanazawa University | Yamashita M.,Tohoku University
Journal of the American Chemical Society | Year: 2012

Two one-dimensional (1D) manganese complexes, [Mn 2(naphtmen) 2(L)](ClO 4)·2Et 2O·2MeOH· H 2O (1) and [Mn 2(naphtmen) 2(HL)](ClO 4) 2·MeOH (2), were synthesized by using a bridging ligand with a nucleobase moiety, 6-amino-9-β-carboxyethylpurine, and a salen-type manganese(III) dinuclear complex, [Mn 2(naphtmen) 2(H 2O) 2](ClO 4) 2 (naphtmen 2- = N,N′-(1,1,2,2-tetramethylethylene) bis(naphthylideneiminato) dianion). In 1 and 2, the carboxylate-bridged Mn III dinuclear units are alternately linked by two kinds of weak Mn⋯O interactions into 1D chains. As a result, canted antiferromagnetic and ferromagnetic interactions are alternately present along the chains, leading to a 1D chain with non-cancellation of anisotropic spins. Since the chains connected via H-bonds between nucleobase moieties are magnetically isolated, both 1 and 2 act as single-chain magnets (SCMs). More importantly, this result shows the smaller canting angles hinder long-range ordering in favor of SCM dynamics. © 2012 American Chemical Society.


Hasegawa K.,University of Tsukuba | Hasegawa K.,Paris Observatory | Semelin B.,Paris Observatory | Semelin B.,University Pierre and Marie Curie
Monthly Notices of the Royal Astronomical Society | Year: 2013

We explore the impacts of ultraviolet (UV) radiation feedback on galaxies during the epoch of reionization by cosmological simulations in which hydrodynamics and the transfer of the H and He ionizing photons are consistently coupled. Moreover, we take into account H2 non-equilibrium chemistry, including photodissociation. The most striking feature of the simulations is a high spatial resolution for the radiative transfer (RT) calculation which enables us to start considering not only external UV feedback processes but also internal UV feedback processes in each galaxy. We find that the star formation is significantly suppressed due to the internal UV and supernova (SN) feedback. In low-mass galaxies withM <109M⊙, a large amount of gas is evacuated by photoevaporation as previous studies have shown, which results in the suppression of star formation. Surprisingly, star formation in massive haloes is also strongly suppressed despite the fact that these haloes hardly lose any gas by photoevaporation. The suppression of star formation in massive haloes is mainly caused by the following two factors: (i) small-scale clumpy structures in the galaxies are smoothened by the internal feedback; (ii) although the dense gas in the galaxies is mostly neutral, the H2 formation and cooling processes are disturbed by mild photoheating. Photodissociating radiations actually suppress star formation, but the magnitude of the effect is not so large in massive galaxies. Even though our simulation volume is too small to be a representative patch of the Universe during reionization, we find that our simulated star formation rate densities and HI fractions at z ~ 6-7 are consistent with those found in observations. © 2012 The Authors.


Anada T.,Tohoku University | Fukuda J.,University of Tsukuba | Sai Y.,Tohoku University | Suzuki O.,Tohoku University
Biomaterials | Year: 2012

Since oxygen is one of the critical limiting factors for maintaining cell viability and function, a great deal of effort is being focused on improving the oxygen supply to three-dimensional (3D) cellular constructs. Here, we report a technique to construct spheroids utilizing 3D culture chips with a rapid and simple method for the replication of the surface structures of a polydimethylsiloxane (PDMS) mold. The resultant spheroid culture chip made it possible to rapidly yield high numbers of the spheroids at a time as well as to obtain uniform spheroids with a narrow size distribution and to collect the spheroids easily and noninvasively. The most important feature of this spheroid culture chip is that it enables direct oxygen supply to the cells because the chip is made with only gas-permeable PDMS. When human hepatoma HepG2 cells were grown on the oxygen-permeable chips as a model for liver cells, the cellular growth was remarkably enhanced, and the anaerobic glycolysis was significantly reduced compared to the non-oxygen-permeable chips. Furthermore, the oxygen-permeable chip improved the albumin secretion rates compared to the conventional spheroid culture system after 10 days. Histochemical and immunohistochemical analyses demonstrated that the oxygen-permeable chip dramatically prevented hypoxia in the core of the spheroids and subsequent central necrosis. Surprisingly, the diameters of approximately 400 and 600 μm were estimated to be the threshold of the hypoxic and survival size, respectively, for the HepG2 spheroids in the oxygenated chip. These results indicate that this chip is useful for engineering 3D cellular constructs with high viability and functionality for tissue engineering. © 2012 Elsevier Ltd.


Michikoshi S.,University of Tsukuba | Kokubo E.,Japan National Astronomical Observatory
Astrophysical Journal Letters | Year: 2016

It has recently been proposed that porous icy dust aggregates are formed by the pairwise accretion of dust aggregates beyond the snowline. We calculate the equilibrium random velocity of porous dust aggregates, taking into account mutual gravitational scattering, collisions, gas drag, and turbulent stirring and scattering. We find that the disk of porous dust aggregates becomes gravitationally unstable as the aggregates evolve through gravitational compression in the minimum-mass solar nebula model for a reasonable range of turbulence strength, which leads to rapid formation of planetesimals. © 2016. The American Astronomical Society. All rights reserved.


Namiki S.,University of Tsukuba | Iwabuchi S.,University of Tsukuba | Pansopha Kono P.,Tokyo University of Information Sciences | Kanzaki R.,Tokyo University of Technology
Nature communications | Year: 2014

Moths use a sophisticated olfactory navigation strategy for resource localization. Here we investigate the neuronal circuits involved in sensory processing to generate locomotor commands for pheromone-source orientation in the moth. We identify a candidate pathway for pheromone processing in the protocerebrum using a mass-staining technique. Our intracellular recordings of pheromone responsiveness detect four major circuits, including a newly identified unstructured neuropil, the superior medial protocerebrum, which supplies output to the lateral accessory lobe (LAL), the premotor centre for walking commands. Interneurons innervating the lower division of the LAL elicited longer responses than those innervating the upper division. Descending interneurons innervating the lower division of the LAL showed a state-dependent flip-flop response. In contrast, input from other visual areas in the protocerebrum mostly converge onto the upper division of the LAL. These results reveal the basic organization of the LAL: the upper division is identified as a protocerebral hub that receives inputs from various areas, while the lower division generates long-lasting activity for locomotor command.


Honda T.,Osaka University | Kojima T.,University of Tsukuba | Kobayashi N.,Tohoku University | Fukuzumi S.,Osaka University | Fukuzumi S.,Ewha Womans University
Angewandte Chemie - International Edition | Year: 2011

Protonation made easy: The formation and crystal structure determination of phthalocyanine protonated at the meso- and isoindole nitrogen atoms (see picture) are achieved by using the free base and a zinc complex of saddle-distorted octaphenylphthalocyanine, respectively. The saddle deformation alters the electronic structure of the phthalocyanine ring and facilitates its protonation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Nakanishi W.,Tohoku University | Matsuno T.,Tohoku University | Ichikawa J.,University of Tsukuba | Isobe H.,Tohoku University
Angewandte Chemie - International Edition | Year: 2011

Ascending and Descending: A combination of two helical molecules and two twisting covalent axes in the form of a macrocycle conjures an illusory molecular object that has a seemingly impossible molecular structure, that is, an endlessly descending circle that consists of an sp2-carbon network, which can be regarded as the molecular expression of Penrose stairs (see picture). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Todoroki T.,University of Tsukuba | Todoroki T.,Accelerator Centre
Nuclear Physics A | Year: 2013

Measurements of two particle azimuthal correlations in relativistic heavy ion collisions provide information of the possible interplay between hard-scattered partons and the hot-dense medium. Toward an understanding of parton-medium coupling, it is indispensable to obtain correlations where contributions from higher harmonic flow(. vn) are rejected. It is also important to produce correlation measurements where the trigger particle is selected relative to second and third order event planes. This enables us to explore path-length dependence of parton energy loss and the influence of the medium on the jets. We present the latest PHENIX results of correlations in which contributions from higher harmonic flow have been subtracted, as well as second and third order event plane-dependent correlations in Au+Au collisions at sNN=200GeV. © 2013 Elsevier B.V.


Okuyama Y.,Tsukuba Botanical Garden | Tanabe A.S.,University of Tsukuba | Kato M.,Kyoto University
Molecular Biology and Evolution | Year: 2012

The reconstruction of an ancient polyploidization history is often challenging, although it is a crucial step in clarifying the mechanisms underlying the contemporary success and diversity of polyploids. Phylogenetic relationships of duplicated gene pairs of polyploids, with respect to their orthologs in related diploids, have been used to address this problem, but they often result in conflicting topologies among different genes. Asimitellaria is an East Asian endemic tetraploid lineage of perennials (genus Mitella; Saxifragaceae) that has diversified in riparian habitats. Phylogenetic analyses of four nuclearencoded, single-copy (per haploid) genes GBSSI-A, GBSSI-B, GS-II, and PepCK all supported a single allopolyploid origin of Asimitellaria, but they did not lead to a consensus about which diploid lineage gave rise to each of the Asimitellaria subgenomes. To address this issue, we used an integrated approach, whereby the four gene data sets and an additional nuclear ribosomal external transcribed spacer and internal transcribed spacer (including a 5.8S ribosomal DNA) data set were concatenated in all possible combinations, and the most probable data combination was determined together with the phylogenetic inference. This resulted in relatively robust support for the two closely related North American diploid species as the ancestral lineages of the Asimitellaria subgenomes, suggesting ancient intercontinental migration of the diploid or tetraploid lineages and subsequent tetraploid diversification in the Japanese Archipelago. The present approach enabled sorting out the duplicated genes into their original combinations in their preduplication ancestors under a maximum-likelihood framework, and its extension toward genome sequencing data may help in the reconstruction of ancestral, preduplicated, whole-genome structures. © The Author 2011.


Santosh M.,Kochi University | Santosh M.,National Geophysical Research Institute | Xiao W.J.,China University of Geosciences | Tsunogae T.,CAS Institute of Geology and Geophysics | And 2 more authors.
Precambrian Research | Year: 2012

The Palghat-Cauvery Suture Zone (PCSZ) in southern India defines the trace of the collisional suture developed during the assembly of the Gondwana supercontinent through the closure of the Mozambique Ocean in the Late Neoproterozoic-Cambrian. Here we report Secondary Ion Mass Spectrometry (SIMS) U-Pb ages from zircons in plagiogranites and gabbros from a suprasubduction zone ophiolitic complex at Manamedu, located along the southern periphery of the PCSZ. The morphology and internal structures, together with the high Th/U values of the zircons from the plagiogranite suggest a magmatic crystallization history. The dominant population of zircons in the two plagiogranite samples analyzed in this study yield 206Pb/ 238U ages of 737±23Ma and 782±24Ma corresponding to the timing of emplacement of these rocks. The plagiogranite from Manamedu also contains two other zircon populations: the first group shows a discordant population with 207Pb/ 206Pb ages between 2278 and 2527Ma with an upper intercept age of 2418±65Ma. Similar Neoarchean-early Paleoproterozoic ages have been widely reported from the surrounding rocks within the PCSZ and also from the Salem Block to the north. We interpret these older zircons as xenocrysts entrained in the plagiogranite during magma ascent and consolidation. The third group of zircons in the plagiogranite yield 206Pb/ 238U age of 513±4.6Ma, comparing well with the Cambrian ages reported in several recent studies from magmatic and metamorphic rocks in the PCSZ and the crustal blocks to the south, correlating with the tectono-thermal events associated with the collision and post-collisional extension associated with the assembly of the Gondwana supercontinent. Zircons in the two gabbro samples from the Manamedu complex analyzed in this study yield well-defined clusters on the concordia and show weighted mean 206Pb/ 238U ages of 744±11Ma and 786±7.1Ma. The internal structure of the zircons from these gabbro samples and their high Th/U values also suggest a magmatic crystallization history. The zircon ages that we obtained from the Manamedu forearc complex also compare with the recently reported zircon age of 825±17 from the gabbro-anorthosite complex and the 766±8Ma age from oscillatory-zoned euhedral crystals of magmatic zircons in felsic volcanic suite of the Kadavur Dome, to the south of Manamedu. The ages also compare with the 819±26Ma 206Pb/ 238U age reported from zircons in arc-related rapakivi granite from an adjacent locality within the PCSZ. All these data suggest a prominent mid Cryogenian subduction system along the southern periphery of the PCSZ prior to the destruction of the Mozambique Ocean lithosphere and the final amalgamation of the Gondwana supercontinent. © 2011 Elsevier B.V.


Hirasawa S.,Tohoku University | Watanabe H.,University of Tsukuba | Kizuka T.,University of Tsukuba | Nakagawa Y.,Tohoku University | Tomishige K.,Tohoku University
Journal of Catalysis | Year: 2013

The mechanism of the oxidation of glycerol to dihydroxyacetone over Pd-Ag catalysts was discussed. Characterization results suggest that the metal composition of the surface of the crystalline Pd-Ag alloy particles is almost the same as the bulk composition. The synergetic effects of Pd and Ag appear on the oxidation of the secondary OH group of vic-diols. The reaction order with respect to glycerol concentration over Pd-Ag/C was zero, suggesting the strong interaction between glycerol and the catalyst surface. The reaction order with respect to O2 pressure was 0.4, suggesting that the rate-determining step is the reaction involving oxygen species. These reaction trends and characterization results support the mechanism where the terminal OH group of glycerol is adsorbed on the Ag site and the neighboring secondary OH group (CH-OH) is attacked by the oxygen species dissociatively adsorbed on the Pd site.


Zhou H.,Tsinghua University | Fan P.,Tsinghua University | Li J.,University of Tsukuba
IEEE Transactions on Vehicular Technology | Year: 2011

Proportional fair scheduling has attracted much attention and has been well studied in the single-cell network scenario, where only one base station (BS) serves many users. However, for a network where one user may obtain services from multiple BSs geographically located apart, not much work has been done. In this paper, we investigate how to achieve proportional fair allocation of users' throughput in a wireless network with multiple BSs and multiple users. A low-complexity algorithm is presented. We prove that the developed algorithm is approximately optimal in the sense of maximizing a global proportional fairness utility. Furthermore, two different implementation strategies to achieve the global proportional fair scheduling are proposed: one for networks where inter-BS communications are allowed and the other for networks where only the transmissions between BSs and users are possible. The later implementation makes the algorithm operate in a totally distributed manner. Various simulations confirm that the new global fair scheduling scheme outperforms the single-cell proportional fair scheme in terms of the average user throughput, user throughput oscillation, and fairness. Low-complexity and distributed implementation achieves almost the same performance as the centralized counterpart. © 2011 IEEE.


Ishihara J.,Tohoku University | Ohno Y.,University of Tsukuba | Ohno H.,Tohoku University
Applied Physics Express | Year: 2014

Using time- and spatially-resolved Kerr microscopy, we directly measure the spatiotemporal evolution of photoexcited local spins of a twodimensional electron gas in a modulation-doped GaAs/AlGaAs quantum well with a top gate electrode. The spatial pattern of spins after diffusion is controlled by a gate voltage that changes the strength of the spin-orbit interaction (SOI) field. By measuring the time dependence of spin distribution with an external magnetic field, we successfully observe a persistent spin helix state by tuning the gate voltage, and we obtain both Rashba and Dresselhauss SOI parameters separately. © 2014 The Japan Society of Applied Physics.


Nakagawa Y.,Tohoku University | Nakazawa H.,Tohoku University | Watanabe H.,University of Tsukuba | Tomishige K.,Tohoku University
ChemCatChem | Year: 2012

Gas-phase hydrogenation of furfural to tetrahydrofurfuryl alcohol is catalyzed by Ni/SiO 2 with <4nm Ni particle size, which is prepared by the reduction of supported nickel nitrate. The maximum yield is 94%. The conversion of furfural to the furfuryl alcohol intermediate is less structure-sensitive. The subsequent step in which furfuryl alcohol is converted to tetrahydrofurfuryl alcohol is inhibited by the presence of furfural because furfural is more strongly adsorbed onto the catalyst surface than furfuryl alcohol. This step is strongly structure-sensitive and smaller turnover frequency (TOF) values are observed over Ni/SiO 2 catalysts with a larger particle size. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ishibashi N.,University of Tsukuba | Tada T.,Accelerator Centre
Journal of Physics A: Mathematical and Theoretical | Year: 2015

We argue that an infinite circumference limit can be obtained in two-dimensional conformal field theory by adopting as a Hamiltonian instead of L0. The theory obtained has a circumference of infinite length and hence exhibits a continuous and heavily degenerated spectrum as well as the continuous Virasoro algebra. The choice of this Hamiltonian was inspired partly by the so-called sine-square deformation, which is found in the study of a certain class of quantum statistical systems. The enigmatic behavior of sine-square deformed systems such as the sharing of their vacuum states with the closed boundary systems can be understood by the appearance of an infinite circumference. © 2015 IOP Publishing Ltd.


Tachiki M.,University of Tsukuba | Ivanovic K.,University of Tsukuba | Kadowaki K.,University of Tsukuba | Koyama T.,Tohoku University
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

The emission of terahertz electromagnetic waves from an intrinsic Josephson junction array (IJJA) embedded in an LCR resonant circuit is studied theoretically. A bias current is applied to the electrodes at the top and bottom of the array. In the voltage state, the ac Josephson current generates a displacement current in the IJJA, and both the currents induce an oscillating current in the electrodes. We describe the whole system, including the array and the environment around it, in terms of an LCR resonant circuit. When the Josephson frequency is in the resonance frequency region of the LCR circuit, the amplitudes of the displacement current in the Josephson junction array and the oscillating current in the electrodes both are strongly enhanced by a feedback process. We calculate the emission power and the current-voltage (I-V) characteristic curve for the system. Inside the frequency region of the LCR circuit resonance, stable and intense emission occurs in both the increasing and decreasing processes of the high-bias current. In the emission region the I-V characteristic curve has a dip structure. These results are consistent with those of the emission observed in a high-bias current region by using mesa-shaped samples of Bi2Sr2CaCu2O 8+δ. We also discuss the difference between the properties of the emission and the I-V characteristic curve for intrinsic Josephson junctions embedded in and shunted by the LCR resonant circuit. © 2011 American Physical Society.


Kawakatu N.,University of Tsukuba | Ohsuga K.,Japan National Astronomical Observatory
Monthly Notices of the Royal Astronomical Society | Year: 2011

We propose a new method to explore the candidate super-Eddington active galactic nuclei (AGNs). We examine the properties of infrared (IR) emission from the inner edge of the dusty torus in AGNs, which are powered by super- or sub-Eddington accretion flows around black holes, by considering the dependence of the polar angle on the radiation flux of accretion flows. We find that for super-Eddington AGNs, of which the mass accretion rate is more than 10 2 times larger than the Eddington rate, the ratio of the AGN IR luminosity and the disc bolometric luminosity is less than 10 -2, unless the half opening angle of the torus (θ torus) is small (θ torus<65°). This is due to the self-occultation effect, whereby the self-absorption at the outer region of the super-Eddington flow dilutes the illumination of the torus. Such a small luminosity ratio is not observed in sub-Eddington AGNs, whose mass accretion rate is comparable to or no more than 10 times larger than the Eddington mass accretion rate, except for extremely thin tori (θ torus > 85°). We also consider the properties of the near-IR (NIR) emission radiated from hot dust >1000K. We find that super-Eddington AGNs have a ratio of the NIR luminosity to the bolometric luminosity, L NIR, AGN/L bol, disc, at least one order of magnitude smaller than for sub-Eddington AGNs for a wide range of half opening angle (θ torus> 65°), for various types of dusty torus model. Thus, a relatively low L NIR, AGN/L bol, disc is a property that allows identification of candidate super-Eddington AGNs. Lastly, we discuss the possibility that NIR-faint quasars at redshift z~ 6 discovered by a recent deep Sloan Digital Sky Survey may be young quasars whose black holes grow via super-Eddington accretion. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.


Kriz W.,University of Heidelberg | Shirato I.,Juntendo University | Nagata M.,University of Tsukuba | LeHir M.,University of Zürich | Lemley K.V.,Childrens Hospital Los Angeles
American Journal of Physiology - Renal Physiology | Year: 2013

Progressive loss of podocytes is the most frequent cause accounting for end-stage renal failure. Podocytes are complex, terminally differentiated cells incapable of replicating. Thus lost podocytes cannot be replaced by proliferation of neighboring undamaged cells. Moreover, podocytes occupy a unique position as epithelial cells, adhering to the glomerular basement membrane (GBM) only by their processes, whereas their cell bodies float within the filtrate in Bowman's space. This exposes podocytes to the danger of being lost by detachment as viable cells from the GBM. Indeed, podocytes are continually excreted as viable cells in the urine, and the rate of excretion dramatically increases in glomerular diseases. Given this situation, it is likely that evolution has developed particular mechanisms whereby podocytes resist cell detachment. Podocytes respond to stress and injury by undergoing tremendous changes in shape. Foot process effacement is the most prominent and, yet in some ways, the most enigmatic of those changes. This review summarizes the various structural responses of podocytes to injury, focusing on foot process effacement and detachment. We raise the hypothesis that foot process effacement represents a protective response of podocytes to escape detachment from the GBM. © 2013 the American Physiological Society.


Dietl T.,Polish Academy of Sciences | Dietl T.,University of Warsaw | Dietl T.,Tohoku University | Sato K.,Osaka University | And 8 more authors.
Reviews of Modern Physics | Year: 2015

This review presents the recent progress in computational materials design, experimental realization, and control methods of spinodal nanodecomposition under three- and two-dimensional crystal-growth conditions in spintronic materials, such as magnetically doped semiconductors. The computational description of nanodecomposition, performed by combining first-principles calculations with kinetic Monte Carlo simulations, is discussed together with extensive electron microscopy, synchrotron radiation, scanning probe, and ion beam methods that have been employed to visualize binodal and spinodal nanodecomposition (chemical phase separation) as well as nanoprecipitation (crystallographic phase separation) in a range of semiconductor compounds with a concentration of transition metal (TM) impurities beyond the solubility limit. The role of growth conditions, codoping by shallow impurities, kinetic barriers, and surface reactions in controlling the aggregation of magnetic cations is highlighted. According to theoretical simulations and experimental results the TM-rich regions appear in the form of either nanodots (the dairiseki phase) or nanocolumns (the konbu phase) buried in the host semiconductor. Particular attention is paid to Mn-doped group III arsenides and antimonides, TM-doped group III nitrides, Mn- and Fe-doped Ge, and Cr-doped group II chalcogenides, in which ferromagnetic features persisting up to above room temperature correlate with the presence of nanodecomposition and account for the application-relevant magneto-optical and magnetotransport properties of these compounds. Finally, it is pointed out that spinodal nanodecomposition can be viewed as a new class of bottom-up approach to nanofabrication. © 2015 American Physical Society.


Patent
University of Tsukuba and Nihon Kohden | Date: 2016-07-08

An electrocardiogram analyzer includes a first acquiring section that acquires a body surface electrocardiogram of a subject, a second acquiring section that acquires an intracardiac electrocardiogram of a ventricle of a heart of the subject, and an analyzing section that performs a frequency analysis on the intracardiac electrocardiogram and includes a range setting section that sets an analysis time range of the frequency analysis in the intracardiac electrocardiogram based on a unit waveform of the body surface electrocardiogram, and a calculating section that, in the analysis time range, performs the frequency analysis on the intracardiac electrocardiogram, and that calculates an index value indicating a ratio of local abnormal ventricular activities in the intracardiac electrocardiogram.


Patent
Tohoku University and University of Tsukuba | Date: 2010-05-11

A semiconductor device includes: a silicon layer (12); an intermediate silicide layer (28) that is provided on the silicon layer (12), has openings, and includes barium silicide; and an upper silicide layer (14) that covers the intermediate silicide layer (28), is positioned to be in contact with the silicon layer (12) through the openings, has a higher dopant concentration than the dopant concentration of the intermediate silicide layer (28), and includes barium silicide.


News Article | September 29, 2016
Site: www.rdmag.com

Astronomers have discovered a 'hot molecular core', a cocoon of molecules surrounding a newborn massive star, for the first time outside our Galaxy. The discovery, which marks the first important step for observational studies of extragalactic hot molecular cores and challenges the hidden chemical diversity of our universe, appears in a paper in the Astrophysical Journal Volume 827. The scientists from Tohoku University, the University of Tokyo, the National Astronomical Observatory of Japan, and the University of Tsukuba, used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe a newborn star located in the Large Magellanic Cloud, one of the closest neighbors of our Galaxy. As a result, a number of radio emission lines from various molecular gas are detected, which indicates the presence of a hot molecular core associated with the observed newborn star (Fig. 1 and 2). The observations have revealed that the hot molecular core in the Large Magellanic Cloud shows significantly different chemical compositions as compared to similar objects in our Galaxy. In particular, the results suggest that simple organic molecules such as methanol are deficient in this galaxy, suggesting a potential difficulty in producing large organic species indispensable for the birth of life. The research team suggests that the unique galactic environment of the Large Magellanic Cloud affects the formation processes of molecules around a newborn star, and this results in the observed unique chemical compositions. "This is the first detection of an extragalactic hot molecular core, and it demonstrates the great capability of new generation telescopes to study astrochemical phenomena beyond our Galaxy," said Dr. Takashi Shimonishi, an astronomer at Tohoku University, Japan, and the paper's lead author. "The observations have suggested that the chemical compositions of materials that form stars and planets are much more diverse than we expected. " It is known that various complex organic molecules, which have a connection to prebiotic molecules formed in space, are detected from hot molecular cores in our Galaxy. It is, however, not yet clear if such large and complex molecules exist in hot molecular cores in other galaxies. The newly discovered hot molecular core is an excellent target for such a study, and further observations of extragalactic hot molecular cores will shed light on the chemical complexities of our universe.


News Article | February 21, 2017
Site: phys.org

In an advance that could help modify training practices in the swimming world, a research team centered at the University of Tsukuba (Japan) has developed a new method and apparatus to measure drag in a water flume. The method overcomes the disadvantages of earlier approaches, such as their not being applicable to different swimming strokes or only being functional at full speed, and showed good reliability in applied tests. The new approach involves connecting a swimmer in a water flume to load cells at the front and back of the flume. This allows the force in each direction to be calculated relative to maintaining a fixed position by swimming at the same speed as the flow in the flume, thereby allowing the residual thrust to be determined. This can then be compared to a passive state when being towed motionless through the water. "We set six swimmers up in the apparatus and applied different water flow rates to them, while using an underwater metronome to ensure they maintained the required stroke rate," study corresponding author Hideki Takagi says. "We were also able to compare the active drag they were subjected to with passive drag when they were pulled through the water while adopting streamlined positions." The results for active drag showed low variability, suggesting the approach's reliability. The finding that active drag exceeded passive drag also suggests the study's validity, despite this finding not being made in some previous work, because the area of the front of the body when moving through the water is larger when a swimming stroke is being performed. "We expect this methodology to be greatly beneficial in reducing drag and improving swimming times among elite swimmers," lead author Kenzo Narita says. "The effects of minor adjustments in swimming posture can now be precisely determined." The team hopes to build on this study by clarifying the factors that influence active drag and by applying this methodology alongside measurements of swimming efficiency, such as by measuring oxygen intake. Explore further: Role of thrust and drag clarified for swimming microorganisms More information: Kenzo Narita et al, Developing a methodology for estimating the drag in front-crawl swimming at various velocities, Journal of Biomechanics (2017). DOI: 10.1016/j.jbiomech.2017.01.037


Yoshitomi T.,University of Tsukuba | Hirayama A.,Tsukuba University of Technology | Nagasaki Y.,University of Tsukuba | Nagasaki Y.,Japan International Center for Materials Nanoarchitectonics
Biomaterials | Year: 2011

The ultimate objective of nanoparticle-based therapy is to functionalize nanomedicines in a micro-disease environment without any side effects. Here, we reveal that our pH-responsive nitroxide radical-containing nanoparticles (RNP pH) disintegrate within the renal acidic lesion and act as scavengers of reactive oxygen species (ROS), leading to a relief of acute kidney injury (AKI). RNP pH was prepared using amphiphilic block copolymers possessing 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) moieties via amine linkage as a side chain of the hydrophobic segment. The self-assembled RNP pH disintegrated at pH below 7.0 because of a protonation of the amino groups in the hydrophobic core of the nanoparticles, thereby resulting in an improvement in ROS scavenging activity. Using a renal ischemia-reperfusion AKI model in mice, the therapeutic effect of RNP pH on ROS damage was evaluated. Unlike the RNP without pH-triggered disintegration (RNP Non-pH), the RNP pH showed extremely high ROS scavenging activity and renal protective effects. It is interesting to note that the side effect of nitroxide radicals was markedly suppressed due to the compartmentalization of nitroxide radicals in the core of RNP pH in untargeted area. The morphology changes in RNP pH were confirmed by analyzing electron spin resonance spectra, and these findings provide the evidence of the real therapeutic effect of the environment-sensitive specific disintegration of nanoparticles in vivo. © 2011 Elsevier Ltd.


Zhao N.,University of Stuttgart | Honert J.,University of Stuttgart | Schmid B.,University of Stuttgart | Klas M.,University of Stuttgart | And 7 more authors.
Nature Nanotechnology | Year: 2012

The detection of single nuclear spins would be useful for fields ranging from basic science to quantum information technology. However, although sensing based on diamond defects and other methods have shown high sensitivity, they have not been capable of detecting single nuclear spins, and defect-based techniques further require strong defecta-spin coupling. Here, we present the detection and identification of single and remote 13 C nuclear spins embedded in nuclear spin baths surrounding a single electron spin of a nitrogen-vacancy centre in diamond. We are able to amplify and detect the weak magnetic field noise (∼10Â nT) from a single nuclear spin located ∼3Â nm from the centre using dynamical decoupling control, and achieve a detectable hyperfine coupling strength as weak as ∼300Â Hz. We also confirm the quantum nature of the coupling, and measure the spin-defect distance and the vector components of the nuclear field. The technique marks a step towards imaging, detecting and controlling nuclear spins in single molecules.


Li P.,Mississippi State University | Fang Y.,University of Florida | Li J.,University of Tsukuba | Huang X.,CAS Shenzhen Institutes of Advanced Technology
IEEE Transactions on Mobile Computing | Year: 2012

Throughput capacity in mobile ad hoc networks has been studied extensively under many different mobility models. However, most previous research assumes global mobility, and the results show that a constant per-node throughput can be achieved at the cost of very high delay. Thus, we are having a very big gap here, i.e., either low throughput and low delay in static networks or high throughput and high delay in mobile networks. In this paper, employing a practical restricted random mobility model, we try to fill this gap. Specifically, we assume that a network of unit area with n nodes is evenly divided into cells with an area of n -2α, each of which is further evenly divided into squares with an area of n -2β (0 ≤ α ≤ β ≤ {1\2). All nodes can only move inside the cell which they are initially distributed in, and at the beginning of each time slot, every node moves from its current square to a uniformly chosen point in a uniformly chosen adjacent square. By proposing a new multihop relay scheme, we present smooth trade-offs between throughput and delay by controlling nodes' mobility. We also consider a network of area n γ (0≤ γ ≤ 1) and find that network size does not affect the results obtained before. © 2006 IEEE.


Wu L.-H.,Japan International Center for Materials Nanoarchitectonics | Wu L.-H.,University of Tsukuba | Hu X.,Japan International Center for Materials Nanoarchitectonics | Hu X.,University of Tsukuba
Physical Review Letters | Year: 2015

We derive in the present work topological photonic states purely based on conventional dielectric material by deforming a honeycomb lattice of cylinders into a triangular lattice of cylinder hexagons. The photonic topology is associated with a pseudo-time-reversal (TR) symmetry constituted by the TR symmetry supported in general by Maxwell equations and the C6 crystal symmetry upon design, which renders the Kramers doubling in the present photonic system. It is shown explicitly for the transverse magnetic mode that the role of pseudospin is played by the angular momentum of the wave function of the out-of-plane electric field. We solve Maxwell equations and demonstrate the new photonic topology by revealing pseudospin-resolved Berry curvatures of photonic bands and helical edge states characterized by Poynting vectors. © 2015 American Physical Society.


Pereira R.A.O.,University of Tsukuba | Derudder B.,Ghent University
Urban Studies | Year: 2010

This article presents an analysis of the determinants of connectivity change in the world city network (WCN). Drawing on the theoretical research of Saskia Sassen and the subsequent empirical research of the Globalization and World Cities (GaWC) group, connectivity in the WCN is measured through the networked location strategies of globalised service firms. Based on a calculation of the total connectivity of 220 cities across the world for 2000 and 2004, a measurement of connectivity change is produced for this time-period. This measure of connectivity change is then used as the dependent variable in a linear regression model through which are tested a number of hypotheses concerning the determinants of connectivity change. The study analyses WCN change both in general and in sectoral terms, and also examines how the prior presence of service firms impacts connectivity change. © 2010 Urban Studies Journal Limited.


Santosh M.,China University of Geosciences | Yang Q.-Y.,China University of Geosciences | Shaji E.,Kerala University | Tsunogae T.,University of Tsukuba | And 2 more authors.
Gondwana Research | Year: 2015

Sandwiched between the Dharwar Craton in the north and the Neoarchean-Proterozoic crustal blocks to the south, the Coorg Block in southern India is composed dominantly of a suite of arc magmatic rocks including charnockites, TTG (tonalite-trondhjemite-granodiorite)-related granitoid suite and felsic volcanic tuffs together with minor accreted oceanic remnants along the periphery of the block. Coeval mafic and felsic magmatism with magma mixing and mingling in an arc setting is well represented in the block. Here we present the petrology, geochemistry, zircon U-Pb geochronology and Lu-Hf isotopes of all the major lithologies from this block. Computation of metamorphic P-T conditions from mineral chemical data shows consistent granulite-facies P-T conditions of 820-870°C and up to 6kbar. Our geochemical data from major, trace and REE on representative samples of the dominant rock types from the Coorg Block corroborate an arc-related signature, with magma generation in a convergent margin setting. The zircon data yield weighted mean 207Pb/206Pb ages of 3153.4±9 to 3184.0±5.5Ma for syenogranites, 3170.3±6.8Ma for biotite granite, 3275±5.1Ma for trondhjemite, 3133±12 to 3163.8 ±6.9Ma for charnockites, 3156±10 to 3158.3±8.2 for mafic enclaves, 3161±16Ma for diorite and 3173±16Ma for felsic volcanic tuff. An upper intercept age of 3363±59Ma and a lower intercept age of 2896±130Ma on zircons from a charnockite, as well as an evaluation of the Th/U values of the zircon domains against respective 207Pb/206Pb ages suggest that the Mesoarchean magma emplacement which probably ranged from >3.3 to 3.1Ga was immediately followed by metamorphism at ca. 3.0 to 2.9Ga. The ages of magmatic zircons from the charnockites and their mafic granulite enclaves, as well as those from the volcanic tuff and biotite granite, are all remarkably consistent and concordant marking ca. 3.1Ga as the peak of subduction-related crust building in this block, within the tectonic milieu of an active convergent margin. The majority of zircons from the Coorg rocks show Hf isotope features typical of crystallization from magmas derived from juvenile sources. Their Hf crustal model ages suggest that the crust building might have also involved partial recycling of basement rocks as old as ca. 3.8Ga. The crustal blocks in the Southern Granulite Terrane in India preserve strong imprints of major tectonothermal events at 2.5Ga, 2.0Ga, 0.8Ga and 0.55Ga associated with various subduction-accretion-collision or rifting events. However, the Coorg Block is exceptional with our data suggesting that none of the above events affected this block. Importantly, there is also no record in the Coorg Block for the 2.5Ga pervasive regional metamorphism that affected all the other blocks in this region. The geochronological data raise the intriguing possibility that this block is an exotic entity within the dominantly Neoarchean collage in the northern domain of the Southern Granulite Terrane of India. The Mesoarchean arc-related rocks in the Coorg Block suggest that the magma factories and their tectonic architecture in the Early Earth were not markedly different from those associated with the modern-style plate tectonics. © 2013 International Association for Gondwana Research.


Ikeda Y.,University of Tsukuba | Nagasaki Y.,University of Tsukuba | Nagasaki Y.,Japan International Center for Materials Nanoarchitectonics
Journal of Applied Polymer Science | Year: 2014

Poly(ethylene glycol) (PEG) is the most widely used polymer and also the gold standard in the field of drug delivery. Therapeutic oligonucleotides, for example, are modified with PEG at the terminus to increases nuclease resistance and the circulating half-lives. The surface of nanoparticle such as micelle and liposome has been also modified with PEG. At present, one PEGylated therapeutic oligonucleotide has been approved for the market and several more PEGylated products including oligonucleotide and liposome are being tested in clinical settings. This review summarizes the methods and effects of PEGylation on gene delivery. © 2013 Wiley Periodicals, Inc.


Ichinose M.,Meiji University | Nishiyasu T.,University of Tsukuba
Frontiers in Physiology | Year: 2012

The mechanisms by which blood pressure is maintained against the orthostatic stress caused by gravity's effect on the fluid distribution within the body are important issues in physiology, especially in humans who usually adopt an upright posture. Peripheral vasoconstriction and increased heart rate (HR) are major cardiovascular adjustments to orthostatic stress and comprise part of the reflex response elicited via the carotid sinus and aortic baroreceptors (arterial baroreflex: ABR) and cardiopulmonary stretch receptors (cardiopulmonary baroreflex). In a series of studies, we have been characterizing the ABR-mediated regulation of cardiovascular hemodynamics and muscle sympathetic nerve activity (MSNA) while applying orthostatic stress in humans. We have found that under orthostatic stress, dynamic carotid baroreflex responses are modulated as exemplified by the increases in the MSNA, blood pressure, and HR responses elicited by carotid baroreflex unloading and the shorter period of MSNA suppression, comparable reduction and faster recovery of mean arterial blood pressure (MAP) and greater HR response to carotid baroreflex stimulation. Our results also show that ABR-mediated beat-to-beat control over burst incidence, burst strength and total MSNA is progressively modulated as orthostatic stress is increased until induction of syncope, and that the sensitivity of ABR control over the aforementioned MSNA variables is substantially reduced during the development of syncope. We suggest that in humans, the modulation of ABR function under orthostatic stress may be one of the mechanisms by which blood pressure is maintained and orthostatic hypotension limited, and impairment of ABR control over sympathetic vasomotor activity leads to the severe hypotension associated with orthostatic syncope. © 2012 Ichinose and Nishiyasu.


Fukui T.,Ibaraki University | Imura K.-I.,Hiroshima University | Hatsugai Y.,University of Tsukuba
Journal of the Physical Society of Japan | Year: 2013

We explore novel topological phases realized in a superlattice system based on the Wilson-Dirac model. Our main focus is on a two-dimensional analogue of weak topological insulator phases. We find such phases as those characterized by gapless edge states that are protected by symmetry but sensitive to the orientation of the edge relative to the superlattice structure. We show that manifest and hidden reflection symmetries protect such weak topological phases, and propose bulk Z2 indices responsible for the topological protection of the edge states. © 2013 The Physical Society of Japan.


Wipfler B.,Friedrich - Schiller University of Jena | Machida R.,University of Tsukuba | Muller B.,Fachgruppe VIII.3 Radiologische Verfahren | Beutel R.G.,Friedrich - Schiller University of Jena
Systematic Entomology | Year: 2011

External and internal head structures of adults of Galloisiana yuasai (Grylloblattodea) are described. The results are compared with conditions found in representatives of other lower neopteran lineages, notably in Austrophasma and Karoophasma (both Mantophasmatodea). Sutures and ridges of the head capsule are discussed. A new nomenclature for head muscles is presented for the entire Dicondylia (= Zygentoma + Pterygota). Galloisiana (like its sister taxon Grylloblatta) is mostly characterized by plesiomorphic features, such as the largely unspecialized orthopteroid mouthparts, the multisegmented filiform antennae, the presence of trabeculae tentorii, the absence of muscles associated with the antennal ampullae, the presence of musculus stipitalis transversalis (0mx11) and the presence of musculus tentoriofrontalis anterior (0te2). Autapomorphies of Grylloblattodea are: (i) compound eyes composed of only 60 ommatidia or less; (ii) a lacinia with a proximal tooth; (iii) a rounded submentum; (iv) loss of musculus craniohypopharyngealis (0hy3); and (v) loss of musculus labroepipharyngealis (0lb5). The phylogenetic evaluation of 104 characters of the head yields a branching pattern with Grylloblattodea as a sister group of Mantophasmatodea in clade Xenonomia. Putative synapomorphies of both taxa are: (i) a distinct angle (more than 60°) between the submentum and the mentum; (ii) posteriorly oriented labial palpi; (iii) a flat and lobe-like hypopharynx with a suspensorium far ventrad of the anatomical mouth opening; (iv) loss of musculus tentorioparaglossalis (0la6); and (v) a connection between the antennal ampulla and the supraoesophageal ganglion containing nuclei. Xenonomia is placed in a clade with the two dictyopteran terminals. Another monophyletic group is Embioptera + Phasmatodea. Most branches of the single tree obtained in our analysis are weakly supported. The results clearly show that more data and a much broader taxon sampling are required to clarify the phylogenetic interrelationships of the lower neopteran orders. However, our results narrow down the spectrum of possible solutions, and represent a starting point for future phylogenetic analyses, with an extensive concatenated dataset. © 2011 The Authors. Systematic Entomology © 2011 The Royal Entomological Society.


Okumura Y.M.,U.S. National Center for Atmospheric Research | Ohba M.,Japan Central Research Institute of Electric Power Industry | Deser C.,U.S. National Center for Atmospheric Research | Ueda H.,University of Tsukuba
Journal of Climate | Year: 2011

El Niño and La Niñ a exhibit significant asymmetry not only in their spatial structure but also in their duration. Most El Niñ os terminate rapidly after maturing near the end of the calendar year, whereas many La Niñas persist into the following year and often reintensify in boreal winter. Through atmospheric general circulation model experiments, it is shown that the nonlinear response of atmospheric deep convection to the polarity of equatorial Pacific sea surface temperature anomalies causes an asymmetric evolution of surface wind anomalies over the far western Pacific around the mature phase of El Niño and La Niña. Because of the eastward displacement of precipitation anomalies in the equatorial Pacific during El Niño compared to La Niña, surface winds in the western Pacific are more affected by SST forcing outside the equatorial Pacific, which acts to terminate the Pacific event. © 2011 American Meteorological Society.


Pan C.,Japan National Institute of Materials Science | Pan C.,University of Tsukuba | Sugiyasu K.,Japan National Institute of Materials Science | Wakayama Y.,Japan International Center for Materials Nanoarchitectonics | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2013

Molecular wires: Fluorescent conjugated polymers that are sheathed within their own cyclic side chains have been synthesized (see picture). Owing to the unique three-dimensional architecture, the polymers are light-emissive, even in the film state, miscible, allowing the combination of various fluorescence colors, and thermoformable, like conventional plastics. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


De Padova P.,National Research Council Italy | Kubo O.,Japan International Center for Materials Nanoarchitectonics | Olivieri B.,National Research Council Italy | Quaresima C.,National Research Council Italy | And 4 more authors.
Nano Letters | Year: 2012

The synthesis of silicene, graphene-like silicon, has generated very strong interest. Here, we reveal the growth of high aspect ratio, perfectly straight, and aligned silicon nanoribbons, exhibiting pyramidal cross section. They are multistacks of silicene and show in angle-resolved photoemission cone-like dispersion of their φ and φ* bands, at the X̄ point of their one-dimensional Brillouin zone, with Fermi velocity of ∼1.3 × 10 6 m sec-1, which is very promising for potential applications. © 2012 American Chemical Society.


Ikeda Y.,University of Tsukuba | Nagasaki Y.,University of Tsukuba | Nagasaki Y.,Japan International Center for Materials Nanoarchitectonics
Advances in Polymer Science | Year: 2012

PEGylation refers to the covalent attachment of polyethylene glycol to proteins to reduce immunogenicity and extend their time in blood circulation. PEGylation is recognized as a promising method for increasing the therapeutic efficacy of medicines in clinical settings. The main advantages of PEGylation are (1) an increase in the size of drug molecule, resulting in reduced filtration by kidneys, (2) an increase in solubility, and (3) protection from enzymatic digestion and recognition by antibodies. A variety of molecules, such as small molecules, peptides, proteins, enzymes, antibodies and their fragments, and nanoparticles have been modified with PEG. Several PEGylated drugs have been approved by the US Food and Drug Administration (FDA) and several more are being tested in clinical settings. This review summarizes the methodologies and effects of PEGylation on drug delivery and highlights recent developments in PEGylated drugs. © 2011 Springer-Verlag Berlin Heidelberg.


Santosh M.,China University of Geosciences | Shaji E.,Kerala University | Tsunogae T.,University of Tsukuba | Ram Mohan M.,CSIR - Central Electrochemical Research Institute | And 2 more authors.
Precambrian Research | Year: 2013

The southern margin of the Dharwar Craton in Peninsular India preserves the records of an active convergent margin during the Neoarchean. Here we report the discovery of a relatively well-preserved suprasubduction zone ophiolite suite from the Agali hill in Attappadi, along the western extension of the Bhavani Shear Zone. In the Agali hill, from base to top, the rock sequence includes altered ultramafics with vestiges of dunite, thin layer of cumulate pyroxenite, a thick unit of metagabbro with the upper part grading into anorthositic gabbro and carrying thin layers of hornblendite, capped by metavolcanics (amphibolites) carrying veins and pools of trondhjemite. Fragments of metabasite (dolerite) dykes occur within the gabbroic horizon. Elongate bands of metamorphosed banded iron formation in association with amphibolite occur proximally. The lithological distribution in the area represents a typical 'Ocean Plate Stratigraphy' sequence with arc and exhumed sub-arc mantle material toward the north-west, followed by accreted remnants of suprasubduction zone ophiolites, large tracts of TTG gneisses, and amphibolites in association with BIF bands. The central domain is occupied by a granite batholith. Toward the south-east, the dominant lithology grades to a continental shelf sequence represented by metamorphosed psammitic and pelitic rocks (trench) and metacarbonates. The common occurrence of magnesite in association with ultramafic units in the area suggests CO2-induced metasomatism of peridotites in the mantle wedge through fluids released within the subduction zone. We present major, trace and REE data on the Agali Ophiolite Complex which clearly suggest magma derivation in a suprasubduction setting in the absence of any significant crustal contamination. The internal structure as imaged from CL images of zircons separated from metagabbro, trondhjemite and metagranite show features typical of magmatic crystallization, with the grains mantled by bright structureless thin rims developed during a dominantly dry metamorphic event. The U-Pb concordia ages of 2547 ± 17. Ma (MSWD 0.84) and 2547 ± 7.4. Ma (MSWD 2.4) obtained from zircons in the metagabbro and trondhjemite are indistinguishable; the zircons in the metagranite also show comparable magmatic age of 2532 ± 8.6. Ma (MSWD 2.5) with metamorphic overgrowth at ca. 2470. Ma. These ages correlate well with similar age data reported recently from suprasubduction zone and arc-related rocks elsewhere along the southern margin of the Dharwar Craton. We propose a tectonic model that envisages accretion of oceanic arcs and micro-continents onto the margin of the Dharwar Craton during Neoarchean, marking an important event of continental growth, and broadly coinciding with the global crustal growth event at this time. © 2013 Elsevier B.V.


Ohba M.,Japan Central Research Institute of Electric Power Industry | Ueda H.,University of Tsukuba
Journal of the Meteorological Society of Japan | Year: 2010

Simulations of the Early Cretaceous (120,000,000 years before the present day: 120 Ma) and the Last Cretaceous (65 Ma) have been performed using an atmospheric general circulation model (AGCM) coupled with a 1.5-layer reduced-gravity ocean model. After the initial spin-up period, both the runs are integrated for approximately 70 years. The simulation results confirm the occurrence of first-order changes in tropical atmospheric circulation in response to changes in the land/sea distribution. The simulation results show that the continental drift during the Cretaceous strongly affects the Walker and Hadley circulations. The birth of the Atlantic resulting from the breakup of the Gondwana continent causes splitting of a Walker circulation cell into two, and this in turn reduces the zonal gradient of the equatorial SST over the Pacific. The resultant SST warming in the equatorial Pacific enhances the Hadley circulation. The northward drift of the Indian continent causes significant SST warming in the Indian Ocean and intensifies the monsoon precipitation over Asia. It is also shown that the seasonal variations in the Asian monsoon are much stronger in the 65-Ma run than in the 120-Ma run. Interestingly, continental breakups cause the mega-monsoon system to split into distinct monsoon systems such as the Indian, South American, and African monsoon systems. © 2010, Meteorological Society of Japan.


Ohba M.,Japan Central Research Institute of Electric Power Industry | Nohara D.,Japan Central Research Institute of Electric Power Industry | Ueda H.,University of Tsukuba
Journal of Climate | Year: 2010

Based on the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset, the relationships between the climatological states and transition processes of simulated ENSO are investigated. The air-sea coupled system of the observed ENSO can remain in the weak cold event for up to 2 yr, whereas those of the warm events tend to turn rapidly into a cold phase. Therefore, the authors separately investigate the simulated transition process of a warm-phase and a cold-phase ENSO in the CMIP3 models. Some of the models reproduce the features of the observed transition process of El Niño/La Niña, whereas most models fail to concurrently reproduce the process during both phases. In the CMIP3 models, four climate models simulate well the rapid transition from El Niño to La Niña. The intensity of a rapid transition of El Niño is mainly related to the intensity of the simulated climatological precipitation over the western-central Pacific (WCP). The models that have strong WCP precipitation can simulate the rapid termination of the equatorial zonal wind in the WCP, which tends to result in the termination of El Niño phase. This relationship is not applicable for the La Niña transition phase. The simulation of La Niña persistency is related to the reflection of off-equatorial Rossby waves at the western boundary of the Pacific and the seasonal evolution of the climatological precipitation in the WCP. Differences in the transition processes between El Niño and La Niña events are fundamentally due to the nonlinear atmospheric (convective) response to SST, which originates from the distribution of climatological SST and its seasonal changes. The results of the present study indicate that a realistic simulation of the climatological state and its seasonality in the WCP are important to be able to simulate the observed transition process of the ENSO. © 2010 American Meteorological Society.


Kim Y.-J.,University of Tsukuba | Kim Y.-J.,Japan International Center for Materials Nanoarchitectonics | Ebara M.,Japan International Center for Materials Nanoarchitectonics | Aoyagi T.,University of Tsukuba | Aoyagi T.,Japan International Center for Materials Nanoarchitectonics
Advanced Functional Materials | Year: 2013

A smart hyperthermia nanofiber is described with simultaneous heat generation and drug release in response to 'on-off' switching of alternating magnetic field (AMF) for induction of skin cancer apoptosis. The nanofiber is composed of a chemically-crosslinkable temperature-responsive polymer with an anticancer drug (doxorubicin; DOX) and magnetic nanoparticles (MNPs), which serve as a trigger of drug release and a source of heat, respectively. By chemical crosslinking, the nanofiber mesh shows switchable changes in the swelling ratio in response to alternating 'on-off' switches of AMF because the self-generated heat from the incorporated MNPs induces the deswelling of polymer networks in the nanofiber. Correspondingly, the 'on-off' release of DOX from the nanofibers is observed in response to AMF. The 70% of human melanoma cells died in only 5 min application of AMF in the presence of the MNPs and DOX incorporated nanofibers by double effects of heat and drug. Taken together these advantages on both the nano- and macroscopic scale of nanofibers demonstrate that the dynamically and reversibly tunable structures have the potential to be utilized as a manipulative hyperthermia material as well as a switchable drug release platform by simple switching an AMF 'on' and 'off'. A smart hyperthermia nanofiber with dynamically and reversibly tunable properties demonstrates the ability to generate heat and release an anticancer drug in response to simple 'on' and 'off' switching of the alternating magnetic field. This smart nanofiber effectively induces the apoptosis of cancer cells by a synergistic effect of the anticancer drug and hyperthermia. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Siburian R.,University of Tsukuba | Siburian R.,Nusa Cendana University | Kondo T.,University of Tsukuba | Nakamura J.,University of Tsukuba
Journal of Physical Chemistry C | Year: 2013

Size controlled Pt catalysts supported by graphene nanosheets (GNS) are successfully prepared by changing the loading of Pt at 10-70 wt % using an impregnation method. It is found that Pt sub-nanoclusters (0.8 nm) with an extremely large surface area (170 m2 g-1) are formed on the GNS support in a 10 wt % Pt/GNS catalyst. An increase in loading of Pt leads to an increase in the particle sizes of Pt, which results in lower activities for electro-oxidation of adsorbed CO. A core level shift of Pt 4f in XPS indicates that Pt is chemically interacted with graphene. The modification of catalytic properties and the electronic structure is ascribed to the interface interaction between Pt and graphene via π-d hybridization. © 2013 American Chemical Society.


Li H.,Japan National Institute of Advanced Industrial Science and Technology | Li H.,Japan International Center for Materials Nanoarchitectonics | Liu X.,Japan National Institute of Advanced Industrial Science and Technology | Liu X.,University of Tsukuba | And 4 more authors.
Advanced Energy Materials | Year: 2013

Li3VO4 was prepared by a solid-state method. Appropriate ratios of dried V 2 O 5 and Li 2 CO 3 powders (Li:V = 3:1 in mol/mol) were mixed thoroughly using an agate mortar, then the mixture were annealed at 600 °C for 5 h followed by 900 °C for 3 h in air in an temperature-controlled furnaces. The obtained powder was grounded for use as an active electrode material for battery tests. Powder X-ray diffraction (XRD) patterns were collected with a Bruker D8 Advanced Diffractometer using Cu K a radiation. The morphologies of the samples were examined by fi eld-emission scanning electron microscopy (FE-SEM, Hitachi S-4800) and high-resolution transmission electron microscopy (HRTEM, JEOL JEM-3000F). For Ex-situ XRD measurements, the electrode was picked from a freshly charge/ discharged coin-type cell and sealed with Mylar fi lm in an argon-fi lled glove box, and then immediately performed the XRD measurement. The electrochemical performances were measured with coin-type cells which coupled a Li3VO4 composite electrode and a Li metal electrode. The Li3VO4 composite electrode was made by 75% of Li3VO4 , 20% of conducting agent and 5% of binder in weight. Cu grid was used as the current collector and 1 M LiPF 6 in EC/DEC (EC:DEC = 1:1 in v/v) was used as the electrolyte. The specifi c capacity was based on the weight of Li 3VO4 in the composite electrode. © 2013 WILEY-VCH Verlag GmbH and Co.


Weng Q.,Japan International Center for Materials Nanoarchitectonics | Weng Q.,University of Tsukuba | Wang X.,Japan International Center for Materials Nanoarchitectonics | Zhi C.,City University of Hong Kong | And 3 more authors.
ACS Nano | Year: 2013

Layered boron nitrides (BNs) are usually viewed as excellent protective coatings and reinforcing materials due to their chemical inertness and high mechanical strength. However, the attention paid to their potential applications in gas sorption, especially in case of hydrogen, has obviously been insufficient. Herein, a novel BN material (i.e., porous microbelts), with the highest specific surface area ever reported for any BN system, up to 1488 m 2 g-1, is obtained through one-step template-free reaction of a boron acid-melamine precursor with ammonia. Comprehensive high-resolution transmission electron microscopy, X-ray diffraction, and Raman characterizations all confirm that the obtained BN phase is partially disordered, shows an enlarged average spacing between adjacent (0002) layers (d0002 = 0.38 nm, compared to normal 0.33 nm for a bulk layered BN), and belongs to an intermediate state between hexagonal (h-BN) and amorphous (a-BN) phases. By changing the synthesis temperatures, the textures of obtained porous microbelts are adjustable. H2 sorption evaluations demonstrate that the materials exhibit high and reversible H2 uptake from 1.6 to 2.3 wt % at 77 K and at a relatively low pressure of 1 MPa. © 2013 American Chemical Society.


Mao H.,Japan International Center for Materials Nanoarchitectonics | Mao H.,University of Tsukuba | Kawazoe N.,Japan International Center for Materials Nanoarchitectonics | Chen G.,Japan International Center for Materials Nanoarchitectonics | Chen G.,University of Tsukuba
Biomaterials | Year: 2013

Carbon nanotubes (CNTs) have shown great potential for biological and medical applications because of their intrinsic unique properties. However, applications of CNTs have been severely restricted by their super-hydrophobicity and easy aggregation in aqueous medium, which are related to cytotoxicity and other negative cellular effects. In this study, single-walled carbon nanotubes (SWCNTs) were functionalized with collagen (collagen-SWCNTs). The collagen-SWCNTs retained the inherent properties of SWCNTs and the suspension solution was stable for months. The cellular effects, uptake and intracellular distribution of the collagen-SWCNTs were investigated by using them for culture of bovine articular chondrocytes (BACs). The collagen-SWCNTs showed no obvious negative cellular effects and high amount of SWCNTs were internalized by cells. The internalized collagen-SWCNTs were distributed in the perinuclear region and retained in the cells for more than one week. Adsorption of SWCNTs by extracellular matrix (ECM) was shown to be an important step for cellular uptake of SWCNTs. The high stability, easy cellular uptake and long retention in cells of the collagen-SWCNTs will facilitate the biomedical and biotechnological applications of SWCNTs. © 2013 Elsevier Ltd.


Ishikawa K.-I.,Hiroshima University | Iwasaki Y.,University of Tsukuba | Nakayama Yu.,Kavli Institute for the Physics and Mathematics of the Universe | Yoshie T.,University of Tsukuba
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We investigate SU(3) gauge theories in four dimensions with Nf fundamental fermions on a lattice using the Wilson fermion. Clarifying the vacuum structure in terms of Polyakov loops in spatial directions and properties of temporal propagators using a new method that we call "local analysis," we conjecture that the "conformal region" exists together with the confining region and the deconfining region in the phase structure parametrized by β and K, both in the cases of the large Nf QCD within the conformal window (referred as conformal QCD) with an IR cutoff and small Nf QCD at T/Tc>1 with Tc being the chiral transition temperature (referred to as high-temperature QCD). Our numerical simulation on a lattice of the size 163×64 shows the following evidence of the conjecture. In the conformal region, we find that the vacuum is the nontrivial Z(3) twisted vacuum modified by nonperturbative effects and that temporal propagators of mesons behave at large t as a power-law-corrected Yukawa-type decaying form. The transition from the conformal region to the deconfining region or the confining region is a sharp transition between different vacua, and therefore, it suggests a first-order transition both in conformal QCD and high-temperature QCD. To confirm the conjecture and distinguish it from the possibility of crossover phenomena, we need to take the continuum/thermodynamic limit, which we do not attempt in this work. Within our fixed-lattice simulation, we find that there is a precise correspondence between conformal QCD and high-temperature QCD in the temporal propagators under the change of the parameters Nf and T/Tc, respectively: one boundary is close to meson states, and the other is close to free quark states. In particular, conformal QCD with Nf=7 corresponds to high-temperature QCD with Nf=2 at T∼2Tc, both of which are in close relation to a meson unparticle model. From this, we estimate the anomalous mass dimension γ*=1.2(1) for Nf=7. We also show that the asymptotic state in the limit T/Tc→is a free quark state in the Z(3) twisted vacuum. The approach to a free quark state is very slow; even at T/Tc∼105, the state is affected by nonperturbative effects. This is possibly connected with the slow approach of the free energy to the Stefan-Boltzmann ideal gas limit. © 2014 American Physical Society.


Ge J.,University of the Humanities | Lei Y.,University of the Humanities | Tokunaga S.,University of Tsukuba
Energy | Year: 2014

Concerning food security, China has launched non-grain fuel ethanol projects with potential land. However, there are concerns and facts, such as feedstock price rise, regarding its implications on quantity of food supply and food price. The study aims to better understand the impacts of expanding non-grain fuel ethanol on food price, supply and consumption using a CGE (computable general equilibrium) model. The investigation is divided into two scenarios, no supply of potential land and supply of potential land. The results show that: an increase in the fuel ethanol production raises food prices under both scenarios; and food supply and consumption can be ensured when there is a supply of potential land. Also, the simulated results predict adequate and quality potential land supply is one of the most important aspects to ensure food security in China. In addition, financial and trade policy implications are proposed. © 2013 Elsevier Ltd.


Pakdel A.,University of Tsukuba | Pakdel A.,Japan International Center for Materials Nanoarchitectonics | Zhi C.,Japan International Center for Materials Nanoarchitectonics | Bando Y.,Japan International Center for Materials Nanoarchitectonics | And 4 more authors.
ACS Nano | Year: 2011

The growth, structure, and properties of two-dimensional boron nitride (BN) nanostructures synthesized by a thermal chemical vapor deposition method have been systematically investigated. Most of the BN nanosheets (BNNSs) were less than 5 nm in thickness, and their purity was confirmed by X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, electron energy loss spectroscopy, and Raman spectroscopy. The effects of the process variables on the morphology and roughness of the coatings were studied using atomic force microscopy and scanning electron microscopy. A smooth BN coating was obtained at 900 °C, while compact BNNS coatings composed of partially vertically aligned nanosheets could be achieved at 1000 °C and higher temperatures. These nanosheets were mostly separated and exhibited high surface area especially at higher synthesis temperatures. The nonwetting properties of the BNNS coatings were independent of the water pH and were examined by contact angle goniometry. The present results enable a convenient growth of pure BNNS coatings with controllable levels of water repellency, ranging from partial hydrophilicity to superhydrophobicity with contact angles exceeding 150°. © 2011 American Chemical Society.


Jung T.,Alfred Wegener Institute for Polar and Marine Research | Matsueda M.,University of Tsukuba | Matsueda M.,University of Oxford
Quarterly Journal of the Royal Meteorological Society | Year: 2016

High-latitude climate change is expected to increase the demand for reliable weather and environmental forecasts in polar regions. In this study, a quantitative assessment of the skill of state-of-the-art global weather prediction systems in polar regions is given using data from the THORPEX Interactive Grand Global Ensemble (TIGGE) for the period 2006/2007-2012/2013. Forecast skill in the Arctic is comparable to that found in the Northern Hemisphere midlatitudes. However, relative differences in the quality between different forecasting systems appear to be amplified in the Arctic. Furthermore, analysis uncertainty in the Arctic is more of an issue than it is in the midlatitudes, especially when it comes to near-surface parameters over snow- and ice-covered surfaces. Using NOAA's reforecast dataset, it is shown that the changes in forecast skill during the 7-year period considered here can largely be explained by flow-dependent error growth, especially for the more skilful forecasting systems. Finally, a direct comparison between the Arctic and Antarctic suggests that predictions of mid-topospheric flow in the former region are more skilful. © 2016 Royal Meteorological Society.


Ishikawa K.-I.,Hiroshima University | Iwasaki Y.,University of Tsukuba | Nakayama Y.,California Institute of Technology | Yoshie T.,University of Tsukuba
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We propose a novel RG method to specify the location of the IR fixed point in lattice gauge theories and apply it to the SU(3) gauge theories with Nf fundamental fermions. It is based on the scaling behavior of the propagator through the RG analysis with a finite IR cutoff, which we cannot remove in the conformal field theories in sharp contrast to the confining theories. The method also enables us to estimate the anomalous mass dimension in the continuum limit at the IR fixed point. We perform the program for Nf = 16, 12, 8 and Nf = 7 and indeed identify the location of the IR fixed points in all cases. © 2015 Published by Elsevier B.V..


News Article | November 11, 2015
Site: www.scientificcomputing.com

Running is one of the most popular sports. However, not many runners have received formal training on running. Associate Professor Shinichi Yamagiwa of the University of Tsukuba and his colleagues have developed a system for improving running skills based on big data analysis. Dr. Yamagiwa, Associate Professor Yoshinobu Kawahara of Osaka University and Mizuno have jointly developed a technology that instructs the ideal running motions based on “big data of motions” collected by monitoring motions during running via sensors and videos. The research team analyzed the running motion data of about 2,000 runners by using an artificial intelligence technique and expressed the results in numerical skill values. They discovered that the movements of the elbows, knees and ankles differed between high-rank marathon runners and beginners. Based on the findings, a technology called “skill grouping” was developed to assisting runners in improving their skills by displaying the effects of the movements in easy-to-understand scores. Skill grouping can also be used for time-sequential healthcare and motor capacity control, such as during conditioning and rehabilitation. As it converts movements into objective values, it will enable information devices that have been difficult to generalize to be developed and is, thus, expected to lead to development of healthcare tools in the era of the Internet of Things, such as mobile-phone applications. Another possible application of skill grouping is to assist transmission of traditional performance arts and design skills. Skill grouping is expected to realize a new system of artificial intelligence supporting “transmission of traditional skills” for globally urgent issues. Citation: Shinichi Yamagiwa, Yoshinobu Kawahara, Noriyuki Tabuchi, Yoshinobu Watanabe, Takeshi Naruo, Skill Grouping Method: Mining and Clustering Skill Differences from Body Movement BigData, Proceeding of International conference on BigData 2015, IEEE (October 29-November 1, 2015 •Santa Clara, CA, USA)


News Article | November 9, 2015
Site: phys.org

Running is one of the most popular sports. However, not many runners have received formal training on running. Associate Professor Shinichi YAMAGIWA of the University of Tsukuba and his colleagues have developed a system for improving running skills based on big data analysis. Dr. YAMAGIWA, Associate Professor Yoshinobu KAWAHARA of Osaka University and Mizuno Corporation have jointly developed a technology that instructs the ideal running motions based on "big data of motions" collected by monitoring motions during running via sensors and videos. The research team analyzed the running motion data of about 2,000 runners possessed by Mizuno by using the artificial intelligence technique and expressed them in numerical skill values. They discovered that the movements of the elbows, knees and ankles differed between high-rank marathon runners and beginners. Based on the findings, a technology called "skill grouping" was developed for assisting runners improve their skills by displaying the effects of the movements in easy-to-understand scores. Skill grouping can also be used for time-sequential health care and motor capacity control such as during conditioning and rehabilitation. As it converts movements into objective values, it will enable information devices that have been difficult to generalize to be developed and is thus expected to lead to development of health care tools in the era of the Internet of Things such as mobile-phone application. Another possible application of skill grouping is to assist transmission of traditional performance arts and design skills. Skill grouping is expected to realize a new system of artificial intelligence supporting "transmission of traditional skills", which is one of globally urgent issues. Explore further: Researchers develop a device for running shoes that prevents injuries More information: Shinichi Yamagiwa, Yoshinobu Kawahara, Noriyuki Tabuchi, Yoshinobu Watanabe, Takeshi Naruo, Skill Grouping Method: Mining and Clustering Skill Differences from Body Movement BigData, Proceeding of International conference on BigData 2015, IEEE (October 29-November 1, 2015 •Santa Clara, CA, USA)


Suzuki D.G.,University of Tsukuba | Murakami Y.,Ehime University | Escriva H.,University Pierre and Marie Curie | Wada H.,University of Tsukuba
Journal of Comparative Neurology | Year: 2015

Vertebrates are equipped with so-called camera eyes, which provide them with image-forming vision. Vertebrate image-forming vision evolved independently from that of other animals and is regarded as a key innovation for enhancing predatory ability and ecological success. Evolutionary changes in the neural circuits, particularly the visual center, were central for the acquisition of image-forming vision. However, the evolutionary steps, from protochordates to jaw-less primitive vertebrates and then to jawed vertebrates, remain largely unknown. To bridge this gap, we present the detailed development of retinofugal projections in the lamprey, the neuroarchitecture in amphioxus, and the brain patterning in both animals. Both the lateral eye in larval lamprey and the frontal eye in amphioxus project to a light-detecting visual center in the caudal prosencephalic region marked by Pax6, which possibly represents the ancestral state of the chordate visual system. Our results indicate that the visual system of the larval lamprey represents an evolutionarily primitive state, forming a link from protochordates to vertebrates and providing a new perspective of brain evolution based on developmental mechanisms and neural functions. © 2014 Wiley Periodicals, Inc.


Fukuzumi S.,Osaka University | Fukuzumi S.,Japan Science and Technology Agency | Fukuzumi S.,Ewha Womans University | Honda T.,Osaka University | And 2 more authors.
Coordination Chemistry Reviews | Year: 2012

Porphyrins and phthalocyanines are planar two-dimensional π-compounds, which are normally difficult to protonate because of the low basicity. When many bulky substituents are introduced to porphyrins and phthalocyanines, however, the macrocyclic π-plane is distorted due to the steric repulsion of the bulky substituents. The π-plane distortion facilitates protonation to afford stable protonated porphyrins and phthalocyanines. Crystal structures of protonated porphyrins and phthalocyanines were determined to clarify the role of hydrogen bonding in the supramolecular assemblies. Protonated porphyrinoids can act as an electron acceptor rather than an electron donor in photoinduced electron-transfer reactions. The rate constants of photoinduced electron-transfer reactions of diprotonated porphyrin with different degrees of distortion were determined and they are evaluated in light of the Marcus theory of electron transfer to determine the reorganization energies of electron transfer, which are affected by the distortion of the π-plane. A distortion of the macrocyclic ligands also affords higher Lewis acidity at a metal center to allow facile axial coordination of ligands, due to poor overlap of the lone pair orbitals with d x2-y2 or p x and p y orbitals of the metal center. Thus, the distortion of the macrocyclic ligands enables one to construct various molecular and supramolecular complexes composed of porphyrins and phthalocyanines. The photodynamics of photoinduced electron-transfer reactions of various supramolecular complexes of distorted porphyrin and phthalocyanines are discussed in relation to structure and photofunction. © 2012 Elsevier B.V.


Tormann T.,ETH Zurich | Enescu B.,University of Tsukuba | Woessner J.,Risk Management Solutions Inc. | Wiemer S.,ETH Zurich
Nature Geoscience | Year: 2015

Constraints on the recurrence times of subduction zone earthquakes are important for seismic hazard assessment and mitigation. Models of such megathrust earthquakes often assume that subduction zones are segmented and earthquakes occur quasi-periodically owing to constant tectonic loading. Here we analyse the occurrence of small earthquakes compared to larger ones - the b-values - on a 1,000-km-long section of the subducting Pacific Plate beneath central and northern Japan since 1998. We find that the b-values vary spatially and mirror the tectonic regime. For example, high b-values, indicative of low stress, occur in locations characterized by deep magma chambers and low b-values, or high stress, occur where the subducting and overriding plates are strongly coupled. There is no significant variation in the low b-values to suggest the plate interface is segmented in a way that might limit potential ruptures. Parts of the plate interface that ruptured during the 2011 Tohoku-oki earthquake were highly stressed in the years leading up to the earthquake. Although the stress was largely released during the 2011 rupture, we find that the stress levels quickly recovered to pre-quake levels within just a few years. We conclude that large earthquakes may not have a characteristic location, size or recurrence interval, and might therefore occur more randomly distributed in time. © 2015 Macmillan Publishers Limited. All rights reserved


Obulesu M.,University of Tsukuba | Lakshmi M.J.,Indian Central Food Technological Research Institute
Neurochemical Research | Year: 2014

Alzheimer’s disease (AD) is a devastative neurodegenerative disorder with complex etiology. Apoptosis, a biological process that plays an essential role in normal physiology to oust a few cells and contribute to the normal growth, when impaired or influenced by various factors such as Bcl2, Bax, caspases, amyloid beta, tumor necrosis factor-α, amyloid precursor protein intracellular C-terminal domain, reactive oxygen species, perturbation of enzymes leads to deleterious neurodegenerative disorders like AD. There are diverse pathways that provoke manifold events in mitochondria and endoplasmic reticulum (ER) to execute the process of cell death. This review summarizes the crucial apoptotic mechanisms occurring in both mitochondria and ER. It gives substantial summary of the diverse mechanisms studied in vivo and in vitro. A brief account on neuroprotection of several bioactive components, flavonoids and antioxidants of plants against apoptotic events of both mitochondria and ER in both in vitro and in vivo has been discussed. In light of this, the burgeoning need to develop animal models to study the efficacy of various therapeutic effects has been accentuated. © 2014, Springer Science+Business Media New York.


Honda T.,Osaka University | Kojima T.,University of Tsukuba | Fukuzumi S.,Osaka University | Fukuzumi S.,Ewha Womans University
Journal of the American Chemical Society | Year: 2012

Proton-coupled electron-transfer reduction of dioxygen (O 2) to afford hydrogen peroxide (H 2O 2) was investigated by using ferrocene derivatives as reductants and saddle-distorted (α- octaphenylphthalocyaninato)cobalt(II) (Co II(Ph 8Pc)) as a catalyst under acidic conditions. The selective two-electron reduction of O 2 by dimethylferrocene (Me 2Fc) and decamethylferrocene (Me 10Fc) occurs to yield H 2O 2 and the corresponding ferrocenium ions (Me 2Fc + and Me 10Fc +, respectively). Mechanisms of the catalytic reduction of O 2 are discussed on the basis of detailed kinetics studies on the overall catalytic reactions as well as on each redox reaction in the catalytic cycle. The active species to react with O 2 in the catalytic reaction is switched from Co II(Ph 8Pc) to protonated Co I(Ph 8PcH), depending on the reducing ability of ferrocene derivatives employed. The protonation of Co II(Ph 8Pc) inhibits the direct reduction of O 2; however, the proton-coupled electron transfer from Me 10Fc to Co II(Ph 8Pc) and the protonated [Co II(Ph 8PcH)] + occurs to produce Co I(Ph 8PcH) and [Co I(Ph 8PcH 2)] +, respectively, which react immediately with O 2. The rate-determining step is a proton-coupled electron-transfer reduction of O 2 by Co II(Ph 8Pc) in the Co II(Ph 8Pc)-catalyzed cycle with Me 2Fc, whereas it is changed to the electron-transfer reduction of [Co II(Ph 8PcH)] + by Me 10Fc in the Co I(Ph 8PcH)- catalyzed cycle with Me 10Fc. A single crystal of monoprotonated [Co III(Ph 8Pc)] +, [Co IIICl 2(Ph 8PcH)], produced by the proton-coupled electron-transfer reduction of O 2 by Co II(Ph 8Pc) with HCl, was obtained, and the crystal structure was determined in comparison with that of Co II(Ph 8Pc). © 2012 American Chemical Society.


Taniguchi T.,University of Tokyo | Miyauchi K.,University of Tokyo | Nakane D.,Osaka City University | Miyata M.,Osaka City University | And 3 more authors.
Nucleic Acids Research | Year: 2013

Deciphering the genetic code is a fundamental process in all living organisms. In many bacteria, AUA codons are deciphered by tRNAIle2 bearing lysidine (L) at the wobble position. L is a modified cytidine introduced post-transcriptionally by tRNAIle-lysidine synthetase (TilS). Some bacteria, including Mycoplasma mobile, do not carry the tilS gene, indicating that they have established a different system to decode AUA codons. In this study, tRNAIle2 has been isolated from M. mobile and was found to contain a UAU anticodon without any modification. Mycoplasma mobile isoleucyl-tRNA synthetase (IleRS) recognized the UAU anticodon, whereas Escherichia coli IleRS did not efficiently aminoacylate tRNAIle2 UAU. In M. mobile IleRS, a single Arg residue at position 865 was critical for specificity for the UAU anticodon and, when the corresponding site (W905) in E. coli IleRS was substituted with Arg, the W905R mutant efficiently aminoacylated tRNA with UAU anticodon. Mycoplasma mobile tRNAIle2 cannot distinguish between AUA and AUG codon on E. coli ribosome. However, on M. mobile ribosome, M. mobile tRNA Ile2 UAU specifically recognized AUA codon, and not AUG codon, suggesting M. mobile ribosome has a property that prevents misreading of AUG codon. These findings provide an insight into the evolutionary reorganization of the AUA decoding system. © 2012. Published by Oxford University Press.


Hasegawa K.,French National Center for Scientific Research | Hasegawa K.,University of Tsukuba | Umemura M.,University of Tsukuba
Monthly Notices of the Royal Astronomical Society | Year: 2010

We present a novel radiation hydrodynamics code, START, which is a smoothed particle hydrodynamics (SPH) scheme coupled with accelerated radiative transfer. The basic idea for the acceleration of radiative transfer is parallel to the tree algorithm that is hitherto used to speed up the gravitational force calculation in an N-body system. It is demonstrated that the radiative transfer calculations can be dramatically accelerated, where the computational time is scaled as Np logNs for Np SPH particles and Ns radiation sources. Such acceleration allows us to readily include not only numerous sources but also scattering photons, even if the total number of radiation sources is comparable to that of SPH particles. Here, a test simulation is presented for a multiple source problem, where the results with START are compared to those with a radiation SPH code without tree-based acceleration. We find that the results agree well with each other if we set the tolerance parameter as Θcrit ≤ 1.0, and then it demonstrates that START can solve radiative transfer faster without reducing the accuracy. One of the important applications with START is to solve the transfer of diffuse ionizing photons, where each SPH particle is regarded as an emitter. To illustrate the competence of START, we simulate the shadowing effect by dense clumps around an ionizing source. As a result, it is found that the erosion of shadows by diffuse recombination photons can be solved. Such an effect is of great significance to reveal the cosmic reionization process. © 2010 The Authors. Journal compilation. © 2010 RAS.


News Article | December 9, 2016
Site: www.eurekalert.org

University of Tsukuba-led researchers show that moderate exercise may improve hippocampal memory dysfunction caused by type 2 diabetes and that enhanced transport of lactate to neurons may be the underlying mechanism Tsukuba, Japan - Type 2 diabetes is characterized by impaired glucose metabolism and can cause central nervous system-related complications, such as memory dysfunction. The hippocampus is an essential brain component for normal memory formation. However, the effect of impaired glycometabolism on hippocampal-mediated memory in type 2 diabetes patients is not known. In a new study, researchers centered at the University of Tsukuba investigated whether hippocampal glucose metabolism and memory function is altered in a rat model of type 2 diabetes. Based on the idea that exercise normalizes glycometabolism and improves memory function, the research team also investigated the effects of exercise on hippocampal glycometabolism and memory formation. Hippocampal function was evaluated by placing the rat in a circular pool and testing its ability to remember the location of a platform that would allow it to escape from the water. "This is a well-established method for measuring spatial learning and memory," study first author Takeru Shima says. Type 2 diabetic rats needed more time to escape the water and find the platform. However, after 4 weeks of moderate exercise, they were able to find the platform much faster. "This indicated that exercise significantly improved spatial memory impairments in type 2 diabetic rats," Shima explains. Glycogen levels are altered in tissues of diabetes patients, leading to a variety of complications. However, glycogen levels have not yet been investigated in the hippocampus. "We showed for the first time that glycogen levels are significantly higher in the hippocampus of diabetic rats," corresponding author Hideaki Soya says. Interestingly, single bout of exercise reduced hippocampal glycogen levels and this correlated with an increase in lactate levels. Lactate is an energy substrate and neuromodulator in the hippocampus, and is known to enhance memory formation. Lactate is transferred to neurons through monocarboxylate transporters (MCTs). "MCT2 expression was significantly lower in the hippocampus of type 2 diabetic rats," Soya says, "dysregulated MCT2-mediated neuronal uptake of lactate is a possible aetiology of memory dysfunction in type 2 diabetes, and that elevated hippocampal glycogen may be an adaptive change to compensate for the decreased lactate utilization". 4 weeks of moderate exercise further enhanced glycogen levels and normalized MCT2 expression in the hippocampus of type 2 diabetic rats." These findings suggest that disrupted MCT2-mediated uptake of lactate by neurons contributes to memory dysfunction in type 2 diabetic rats. The findings indicate that moderate exercise could be used to treat memory impairment in patients with type 2 diabetes by promoting the transfer of glycogen-derived lactate to hippocampal neurons. The article "Moderate exercise ameliorates dysregulated hippocampal glycometabolism and memory function in a rat model of type 2 diabetes" was published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]) at DOI: 10.1007/s00125-016-4164-4


News Article | December 21, 2016
Site: www.eurekalert.org

Researchers reveal functionally important gene in a marine invertebrate actually derives from bacteria, and explain how its new function in forming a protective coating around these invertebrates was established Tsukuba, Japan - The transfer of genes from one organism to another is potentially a rapid way for evolution to occur and for complicated novel functions to emerge. However, even when the two organisms in question are in close proximity to each other, such as in a symbiotic or parasitic relationship, the transfer of genetic material and its introduction into a new genome only marks the initial step for successful horizontal gene transfer. It is also necessary for the gene to be expressed in a way that benefits the new host and ensures that it is passed down through the generations. In a new discovery that increases our understanding of gene transfer, a research team centered at University of Tsukuba has studied a gene in marine invertebrates called ascidians originally came from a common bacterium. The team has revealed the likely mechanism by which this gene ended up being expressed in a functionally important and tissue-specific way. The team focused on marine filter feeders called ascidians and their cellulose synthase gene. This gene encodes a protein that helps form an external protective coating, the loss of which leads to a lack of cellulose production and has adverse effects on these organisms. This gene is specifically expressed in the protective outer layer of cells called the epidermis, which was suggested to be key to its coating-related function. "We showed that a region adjacent to the cellulose synthase gene is responsible for its specific epidermal expression," study coauthor Yosuke Ogura says. "Sequence analysis revealed that this region contains a binding site of a transcription factor called AP-2 and, when we induced mutations in this binding site, the expression of cellulose synthase in the ascidian epidermis disappeared." Although all DNA sequences consists of the four letters or bases of A, C, G, and T, their proportions differ depending on the organism. For example, in actinobacteria , over 70% of the DNA consists of Gs and Cs, while the genome of ascidians has an abundance of As and Ts. The AP-2 binding site in ascidians is actually GC-rich, suggesting it originated from another species. It turns out that this GC bias may have been key to its functional integration. "AP-2 inherently binds to GC-rich regions, so it was already primed to start interacting with the bacterial GC-rich DNA once it had integrated into the ascidian genome," first author Yasunori Sasakura says. "The GC-specificity and epidermal expression of AP-2 meant that the introduced cellulose synthase gene could immediately be expressed in its new surroundings in a beneficial way." These findings provide interesting insight into one way in which the conditions in the new host can facilitate expression of a newly transferred gene and its integration into the host's functions, reducing the improbability that a randomly inserted foreign gene could actually be beneficial. The article "Transcriptional regulation of a horizontally transferred gene from bacterium to chordate" was published in Proceedings of the Royal Society of London B at http://dx.


The transfer of genes from one organism to another is potentially a rapid way for evolution to occur and for complicated novel functions to emerge. However, even when the two organisms in question are in close proximity to each other, such as in a symbiotic or parasitic relationship, the transfer of genetic material and its introduction into a new genome only marks the initial step for successful horizontal gene transfer. It is also necessary for the gene to be expressed in a way that benefits the new host and ensures that it is passed down through the generations. In a new discovery that increases our understanding of gene transfer, a research team centered at University of Tsukuba has studied a gene in marine invertebrates called ascidians originally came from a common bacterium. The team has revealed the likely mechanism by which this gene ended up being expressed in a functionally important and tissue-specific way. The team focused on marine filter feeders called ascidians and their cellulose synthase gene. This gene encodes a protein that helps form an external protective coating, the loss of which leads to a lack of cellulose production and has adverse effects on these organisms. This gene is specifically expressed in the protective outer layer of cells called the epidermis, which was suggested to be key to its coating-related function. "We showed that a region adjacent to the cellulose synthase gene is responsible for its specific epidermal expression," study coauthor Yosuke Ogura says. "Sequence analysis revealed that this region contains a binding site of a transcription factor called AP-2 and, when we induced mutations in this binding site, the expression of cellulose synthase in the ascidian epidermis disappeared." Although all DNA sequences consists of the four letters or bases of A, C, G, and T, their proportions differ depending on the organism. For example, in actinobacteria , over 70% of the DNA consists of Gs and Cs, while the genome of ascidians has an abundance of As and Ts. The AP-2 binding site in ascidians is actually GC-rich, suggesting it originated from another species. It turns out that this GC bias may have been key to its functional integration. "AP-2 inherently binds to GC-rich regions, so it was already primed to start interacting with the bacterial GC-rich DNA once it had integrated into the ascidian genome," first author Yasunori Sasakura says. "The GC-specificity and epidermal expression of AP-2 meant that the introduced cellulose synthase gene could immediately be expressed in its new surroundings in a beneficial way." These findings provide interesting insight into one way in which the conditions in the new host can facilitate expression of a newly transferred gene and its integration into the host's functions, reducing the improbability that a randomly inserted foreign gene could actually be beneficial. Explore further: Genetic studies toward plants that resist parasitic weeds More information: Transcriptional regulation of a horizontally transferred gene from bacterium to chordate, Proceedings of the Royal Society B, rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2016.1712


Hiraoka T.,University of Tsukuba | Kakita T.,Kakita Eye Clinic | Okamoto F.,University of Tsukuba | Oshika T.,University of Tsukuba
Ophthalmology | Year: 2015

Purpose: To determine ocular optical parameters that affect axial length elongation in myopic children undergoing overnight orthokeratology. Design: Prospective, noncomparative study. Participants: Fifty-nine subjects who met the inclusion criteria were enrolled in this study. Methods: Axial length and ocular wavefront aberration were assessed before and 1 year after the start of orthokeratology. Corneal topography was performed, and then corneal multifocality was calculated for a 4-mm pupil. After evaluating simple correlations between axial elongation and optical parameters, multiple linear regression analysis was performed to identify explanatory variables with a statistically significant contribution to axial elongation. Main Outcome Measures: Axial length and ocular wavefront aberration before and 1 year after the start of orthokeratology. Results: Fifty-five subjects completed the 1-year follow-up examinations. At baseline, their age ranged from 7.2 to 12.0 years. The manifest spherical equivalent refractive error ranged from -3.50 to -0.75 diopters. The mean axial length significantly increased from 24.20 mm at baseline to 24.43 mm 1 year after treatment. The axial elongation showed significant simple correlations with the change in C2 0, change in second-order aberration, change in coma-like aberration, change in spherical-like aberration, change in total higher-order aberrations, change in corneal multifocality, baseline age, and baseline spherical equivalent refractive error, but not C4 0. Multiple linear regression analysis showed that the change in coma-like aberration was the most relevant variable. Conclusions: Asymmetric corneal shapes, rather than concentric and radially symmetric shapes, have a considerable effect on retardation of axial elongation, suggesting that the inhibitory effect of orthokeratology on myopia progression is caused by mechanisms other than the reduction in peripheral hyperopic defocus. © 2015 by the American Academy of Ophthalmology.


Ariizumi T.,Washington State University | Ariizumi T.,University of Tsukuba | Lawrence P.K.,Washington State University | Steber C.M.,Quality Physiology and Disease Research Unit | Steber C.M.,Washington State University
Plant Physiology | Year: 2011

The SLEEPY1 (SLY1) F-box gene is a positive regulator of gibberellin (GA) signaling in Arabidopsis (Arabidopsis thaliana). Loss of SLY1 results in GA-insensitive phenotypes including dwarfism, reduced fertility, delayed flowering, and increased seed dormancy. These sly1 phenotypes are partially rescued by overexpression of the SLY1 homolog SNEEZY (SNE)/SLY2, suggesting that SNE can functionally replace SLY1. GA responses are repressed by DELLA family proteins. GA relieves DELLA repression when the SCFSLY1 (for Skp1, Cullin, F-box) E3 ubiquitin ligase ubiquitinates DELLA protein, thereby targeting it for proteolysis. Coimmunoprecipitation experiments using constitutively expressed 35S:hemagglutinin (HA)-SLY1 and 35S:HA-SNE translational fusions in the sly1-10 background suggest that SNE can function similarly to SLY1 in GA signaling. Like HA-SLY1, HA-SNE interacted with the CULLIN1 subunit of the SCF complex, and this interaction required the F-box domain. Like HA-SLY1, HA-SNE coimmunoprecipitated with the DELLA REPRESSOR OF GA1-3 (RGA), and this interaction required the SLY1 or SNE carboxyl-terminal domain. Whereas HA-SLY1 overexpression resulted in a decrease in both DELLA RGA and RGA-LIKE2 (RGL2) protein levels, HA-SNE caused a decrease in DELLA RGA but not in RGL2 levels. This suggests that one reason HA-SLY1 is able to effect a stronger rescue of sly1-10 phenotypes than HA-SNE is because SLY1 regulates a broader spectrum of DELLA proteins. The FLAG-SLY1 fusion protein was found to coimmunoprecipitate with the GA receptor HA-GA-INSENSITIVE DWARF1b (GID1b), supporting the model that SLY1 regulates DELLA through interaction with the DELLA-GA-GID1 complex. © 2010 American Society of Plant Biologists.


Miyabe S.,University of Tsukuba | Ono N.,National Institute of Informatics | Makino S.,University of Tsukuba
ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings | Year: 2013

This paper proposes a novel blind compensation of sampling frequency mismatch for asynchronous microphone array. Digital signals simultaneously observed by different recording devices have drift of the time differences between the observation channels because of the sampling frequency mismatch among the devices. Based on the model that such the time difference is constant within each time frame, but varies proportional to the time frame index, the effect of the sampling frequency mismatch can be compensated in the short-time Fourier transform domain by the linear phase shift. By assuming the sources are motionless and stationary, a likelihood of the sampling frequency mismatch is formulated. The maximum likelihood estimation is obtained effectively by a golden section search. © 2013 IEEE.


Wachter G.,Vienna University of Technology | Lemell C.,Vienna University of Technology | Burgdorfer J.,Vienna University of Technology | Sato S.A.,University of Tsukuba | And 2 more authors.
Physical Review Letters | Year: 2014

We theoretically investigate the generation of ultrafast currents in insulators induced by strong few-cycle laser pulses. Ab initio simulations based on time-dependent density functional theory give insight into the atomic-scale properties of the induced current signifying a femtosecond-scale insulator-metal transition. We observe the transition from nonlinear polarization currents during the laser pulse at low intensities to tunnelinglike excitation into the conduction band at higher laser intensities. At high intensities, the current persists after the conclusion of the laser pulse considered to be the precursor of the dielectric breakdown on the femtosecond scale. We show that the transferred charge sensitively depends on the orientation of the polarization axis relative to the crystal axis, suggesting that the induced charge separation reflects the anisotropic electronic structure. We find good agreement with very recent experimental data on the intensity and carrier-envelope phase dependence [A. Schiffrin et al., Nature (London) 493, 70 (2013)]. © 2014 American Physical Society.


Irie T.,Hitachi General Hospital | Kuramochi M.,Hitachi General Hospital | Takahashi N.,University of Tsukuba
CardioVascular and Interventional Radiology | Year: 2013

Purpose: To reveal the mechanism of dense accumulation of lipiodol emulsion (LE) in hepatocellular carcinoma (HCC) during selective balloon-occluded transarterial chemoembolization (B-TACE). Methods: Balloon-occluded arterial stump pressure (BOASP) at the embolization portion was measured during selective B-TACE for 43 nodules in 42 patients. Fluoroscopy and digital subtraction angiography were prospectively observed during selective B-TACE to note whether dense LE accumulation in HCC occurred. The LE concentration ratio of HCC to embolized liver parenchyma (LECHL ratio) was also calculated for each treatment on the basis of the computed tomographic scan obtained immediately after selective B-TACE. The relationships between degree of LE accumulation and the BOASP, as well as the LECHL ratio, were analyzed. Results: Arterial flow beyond the catheter tip was maintained even after balloon inflation. In 39 of 43 treatments, LE inflow into the nontumorous liver parenchyma ceased immediately after LE droplets were filled in arteries of the nontumorous liver parenchyma while LE inflow into the HCC nodule continued (group 1). More dense LE accumulation in HCC nodule was obtained in these 39 treatments. In four treatments, LE inflow both into the nontumorous liver parenchyma and into the HCC nodule continued, and no dense LE accumulation in HCC nodule was observed (group 2). In these four treatments, thick anastomotic vessels with collateral artery were noted. The BOASP in group 1 was (mean ± SD) 33.8 ± 12.8 mmHg (range 13-64 mmHg) and that in group 2 was 92.3 ± 7.4 mmHg (range 83-100 mmHg). There was a statistically significant difference in BOASP between groups (p = 0.00004, Welch's t test). The LECHL ratio in group 1 was 18.3 ± 13.9 (range 2.9-54.2) and that in group 2 was 2.6 ± 1.1 (range 1.7-4.2). There was a statistically significant difference in the LECHL ratio between the groups (p = 0.000034, Welch's t test). Conclusion: Selective B-TACE induced dense LE accumulation in HCC nodules in 39 (91 %) of 43 treatments in which BOASP was 64 mmHg or less. © 2012 Springer Science+Business Media, LLC and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).


Kakita T.,Kakita Eye Clinic | Hiraoka T.,University of Tsukuba | Oshika T.,Kakita Eye Clinic
Investigative Ophthalmology and Visual Science | Year: 2011

PURPOSE. This prospective study was conducted to assess the influence of overnight orthokeratology (OK) on axial elongation in children, with those wearing spectacles as controls. METHODS. One hundred five subjects (210 eyes) were enrolled in the study. The OK group comprised 45 patients (90 eyes, age 12.1 ± 2.5 years, mean ± SD; OK group) who matched the inclusion criteria for OK. The control group comprised 60 patients (120 eyes, 11.9 ± 2.0 years) who also matched the inclusion criteria for OK but preferred spectacles for myopia correction. Axial length was measured at baseline and after 2 years using ocular biometry, and the changes were evaluated and compared between the groups. RESULTS. Ninety-two subjects (42 and 50 in the OK and control groups, respectively) completed the 2-year follow-up examinations. At baseline, the spherical equivalent refractive error was -2.55 ± 1.82 and -2.59 ± 1.66 D, and the axial length was 24.66 ± 1.11 and 24.79 ± 0.80 mm in the OK and control groups, respectively, with no significant differences between the groups. The increase in axial length during the 2-year study period was 0.39 ± 0.27 and 0.61 ± 0.24 mm, respectively, and the difference was significant (P < 0.0001, unpaired t-test). CONCLUSIONS. OK suppressed axial elongation in myopic children, suggesting that this treatment can slow the progression of myopia to a certain extent. © 2011 The Association for Research in Vision and Ophthalmology, Inc.


Kawabata Y.,University of Minnesota | Crick N.R.,University of Minnesota | Hamaguchi Y.,University of Tsukuba
Journal of Abnormal Child Psychology | Year: 2010

The purpose of these studies was to examine the frequency and stability of relational and physical aggression and their associations with social-psychological adjustment or peer victimization, and how friendships are involved in the relations between forms of aggression and peer victimization in Japanese children. The sample consisted of 452 (Study 1) and 138 (Study 2) children who were in the fourth and fifth grades. Results of Study 1 demonstrated that relational aggression was uniquely and more strongly associated with internalizing adjustment problems than physical aggression. Moreover, Study 2 revealed that relational aggression and physical aggression were stable over a 6-month period and the stability of relational aggression was reinforced by negative friendships (i.e., high levels of exclusivity and friend victimization). Further, the association between relational aggression and relative increases in relational victimization was attenuated by positive friendships (i.e., high levels of intimacy, companionship, and friendship satisfaction). Interestingly, friendships were unrelated to physical aggression and its relation to physical victimization. The age and gender of the children in the two studies were also examined. Cultural and developmental processes involving forms of aggression, friendships, social-psychological adjustment, and peer victimization were discussed. © Springer Science+Business Media, LLC 2010.


Hiraoka T.,University of Tsukuba | Kakita T.,Kakita Eye Clinic | Okamoto F.,University of Tsukuba | Takahashi H.,University of Tsukuba | Oshika T.,University of Tsukuba
Investigative Ophthalmology and Visual Science | Year: 2012

PURPOSE. Our prospective study was conducted to compare axial length elongation in myopic children receiving long-term overnight orthokeratology (OK) treatment to those wearing spectacles as controls. METHODS. There were 59 subjects enrolled in this study. The OK group comprised 29 subjects who matched the inclusion criteria for OK. The control group comprised 30 subjects who also matched the inclusion criteria for OK, but preferred spectacles for myopia correction. Axial length was measured periodically for 5 years using an IOLMaster device, and the time course of changes was evaluated and compared between the groups. RESULTS. A total of 43 subjects (22 and 21 in the OK and control groups, respectively) completed the 5-year follow-up examinations. At baseline, the mean age ± SD was 10.04 ± 1.43 and 9.95 ± 1.59 years, the spherical equivalent refractive error was -1.89 ± 0.82 and -1.83 ± 1.06 diopters (D), and the axial length was 24.09 ± 0.77 and 24.22 ± 0.71 mm in the OK and control groups, respectively, with no significant differences between the groups. The increase in axial length during the 5- year study period was 0.99 ± 0.47 and 1.41 ± 0.68 mm for the OK and control groups, respectively, and the difference was statistically significant (P1/40.0236, unpaired t-test). The annual increases in axial length were significantly different between the groups for the first (P 1/4 0.0002), second (P 1/4 0.0476), and third years (P1/40.0385), but not for the fourth (P1/40.0938) and fifth (P 1/4 0.8633) years. There were no severe complications throughout the study period. CONCLUSIONS. The current 5-year follow-up study indicated that OK can suppress axial length elongation in childhood myopia. © 2012 The Association for Research in Vision and Ophthalmology, Inc.


Matsushima T.,University of Tsukuba | Chang C.S.,University of Massachusetts Amherst
Granular Matter | Year: 2011

Assemblies of irregularly shaped particles exhibit higher shear strengths than assemblies of circular particles. We performed a series of 2D discrete element simulations to demonstrate that this particle shape effect is related to the induced moment and the additional dilation at the contacts between particles. We proposed a mechanically based particle shape index that is closely related to such contact behavior. A simple structural model is also investigated to clarify the micromechanical role of the particle shape. © 2011 Springer-Verlag.


Patent
Shirogane Co. and University of Tsukuba | Date: 2015-04-21

A copper alloy having an electrical resistivity lower than those of current copper alloys and a tensile strength higher than those of current copper alloys and a method of manufacturing such a copper alloy are provided. The copper alloy is produced by adding a predetermined amount of carbon to a molten copper in a high-temperature environment of a temperature in the range of 1200 C. to 1250 C. such that the copper alloy has a carbon content in the range of 0.01% to 0.6% by weight.


Patent
University of Tsukuba and Shirogane Co. | Date: 2010-09-03

A copper alloy having an electrical resistivity lower than those of current copper alloys and a tensile strength higher than those of current copper alloys and a method of manufacturing such a copper alloy are provided. The copper alloy is produced by adding a predetermined amount of carbon to a molten copper in a high-temperature environment of a temperature in the range of 1200 C. to 1250 C. such that the copper alloy has a carbon content in the range of 0.01% to 0.6% by weight.


Patent
Shirogane Co. and University of Tsukuba | Date: 2012-07-18

A copper alloy having an electrical resistivity lower than those of current copper alloys and a tensile strength higher than those of current copper alloys and a method of manufacturing such a copper alloy are provided. The copper alloy is produced by adding a predetermined amount of carbon to a molten copper in a high-temperature environment of a temperature in the range of 1200C to 1250C such that the copper alloy has a carbon content in the range of 0.01% to 0.6% by weight.


Okabe T.,Hitachi Ltd. | Terashima H.,University of Tsukuba | Sakamoto A.,Nippon Medical School
British journal of anaesthesia | Year: 2015

BACKGROUND: Although current preoperative fasting guidelines apply restrictions to drinks containing milk because of delayed gastric emptying, the safe volume of milk that can be consumed up to 2 h before surgery on a theoretical basis has not yet been defined. We aimed to determine whether delayed gastric emptying depended mainly on the total amount of calories irrespective of compositional differences between milk and clear fluids.METHODS: We prepared five beverages with a uniform volume (500 ml) and step-wise increments in calories (0, 220, and 330 kcal), comprised mainly of non-human milk, pulpless orange juice, water, and gum syrup. The gastric emptying rate of each beverage was determined by ultrasound measurements of the gastric antral cross-sectional area after their ingestion by eight healthy fasting volunteers.RESULTS: The emptying rates of 500 ml of orange juice and 330 ml of non-human milk with 170 ml of water (both were 220 kcal) from the stomach were similar. Furthermore, 450 ml of orange juice with 50 ml of gum syrup and 500 ml of non-human milk (both were 330 kcal) left the stomach at similar rates. The 220 kcal beverages emptied faster than the 330 kcal beverages.CONCLUSIONS: There were no significant differences in liquid gastric emptying after drinking equal volumes of either orange juice or milk as long as both had the same amount of calories. Liquid gastric emptying depends chiefly on the total caloric content.CLINICAL TRIAL REGISTRATION: UMIN000012537. © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.


Shimizu I.,University of Tokyo | Shimizu I.,Osaka Sangyo University | Yoshida N.,University of Tokyo | Okamoto T.,University of Tsukuba
Monthly Notices of the Royal Astronomical Society | Year: 2012

We use large cosmological smoothed particle hydrodynamics simulations to study the formation and evolution of submillimetre galaxies (SMGs). In our previous work, we studied the statistical properties of ultraviolet-selected star-forming galaxies at high redshifts. We populate the same cosmological simulations with SMGs by calculating the reprocessing of stellar light by dust grains into far-infrared to millimetre wavebands in a self-consistent manner. We generate light-cone outputs to compare directly the statistical properties of the simulated SMGs with available observations. Our model reproduces the submillimetre source number counts and the clustering amplitude. We show that bright SMGs with flux S > 1 mJy reside in haloes with masses of ~1013odot and have stellar masses greater than 1011odot. The angular cross-correlation between the SMGs and Lyman a emitters is significantly weaker than that between the SMGs and Lyman-break galaxies. The cross-correlation is also weaker than the autocorrelation of the SMGs. The redshift distribution of the SMGs shows a broad peak at z ~ 2, where bright SMGs contribute significantly to the global cosmic star formation rate density. Our model predicts that there are hundreds of SMGs with S > 0.1 mJy at z > 5 per 1 deg2 field. Such SMGs can be detected by ALMA. © 2012 The Authors.


Furukawa A.,Japan National Institute of Infectious Diseases | Furukawa A.,Gunma University | Nakada-Tsukui K.,Japan National Institute of Infectious Diseases | Nozaki T.,Japan National Institute of Infectious Diseases | Nozaki T.,University of Tsukuba
PLoS Pathogens | Year: 2012

Lysozymes and hexosaminidases are ubiquitous hydrolases in bacteria and eukaryotes. In phagocytic lower eukaryotes and professional phagocytes from higher eukaryotes, they are involved in the degradation of ingested bacteria in phagosomes. In Entamoeba histolytica, which is the intestinal protozoan parasite that causes amoebiasis, phagocytosis plays a pivotal role in the nutrient acquisition and the evasion from the host defense systems. While the content of phagosomes and biochemical and physiological roles of the major phagosomal proteins have been established in E. histolytica, the mechanisms of trafficking of these phagosomal proteins, in general, remain largely unknown. In this study, we identified and characterized for the first time the putative receptor/carrier involved in the transport of the above-mentioned hydrolases to phagosomes. We have shown that the receptor, designated as cysteine protease binding protein family 8 (CPBF8), is localized in lysosomes and mediates transport of lysozymes and β-hexosaminidase α-subunit to phagosomes when the amoeba ingests mammalian cells or Gram-positive bacillus Clostridium perfringens. We have also shown that the binding of CPBF8 to the cargos is mediated by the serine-rich domain, more specifically three serine residues of the domain, which likely contains trifluoroacetic acid-sensitive O-phosphodiester-linked glycan modifications, of CPBF8. We further showed that the repression of CPBF8 by gene silencing reduced the lysozyme and β-hexosaminidase activity in phagosomes and delayed the degradation of C. perfringens. Repression of CPBF8 also resulted in decrease in the cytopathy against the mammalian cells, suggesting that CPBF8 may also be involved in, besides the degradation of ingested bacteria, the pathogenesis against the mammalian hosts. This work represents the first case of the identification of a transport receptor of hydrolytic enzymes responsible for the degradation of microorganisms in phagosomes. © 2012 Furukawa et al.


Schoville S.D.,University of Tsukuba | Uchifune T.,Yokosuka City Museum | Machida R.,University of Tsukuba
Molecular Phylogenetics and Evolution | Year: 2013

Fragment islands, viewed from the paradigm of island biogeographic theory, depend on continual immigration from continental sources to maintain levels of species diversity, or otherwise undergo a period of relaxation where species diversity declines to a lower equilibrium. Japan is a recently derived fragment island with a rich endemic flora and fauna. These endemic species have been described as paleoendemics, and conversely as recently derived Pleistocene colonists. Geological events in the Miocene period, notably the fragmentation and collision of islands, and the subsequent uplift of mountains in central Japan, provided opportunities for genetic isolation. More recently, cyclical climatic change during the Pliocene and Pleistocene periods led to intermittent land bridge connections to continental Asia. Here we investigate the pattern and timing of diversification in a diverse endemic lineage in order to test whether ongoing migration has sustained species diversity, whether there is evidence of relaxation, and how geological and climatic events are associated with lineage diversification. Using multi-locus genetic data, we test these hypotheses in a poorly dispersing, cold-adapted terrestrial insect lineage (Grylloblattodea: Grylloblattidae) sampled from Japan, Korea, and Russia. In phylogenetic analyses of concatenated data and a species tree approach, we find evidence of three deeply divergent lineages of rock-crawlers in Japan consistent with the pattern of island fragmentation from continental Asia. Tests of lineage diversification rates suggest that relaxation has not occurred and instead endemism has increased in the Japanese Grylloblattidae following mountain-building events in the Miocene. Although the importance of climate change in generating species diversity is a commonly held paradigm in Japanese biogeography, our analyses, including analyses of demographic change and phylogeographic range shifts in putative species, suggests that Pleistocene climatic change has had a limited effect on the diversification of rock-crawlers. © 2012 Elsevier Inc.


Nishimura W.,National Health Research Institute | Nishimura W.,Jichi Medical University | Takahashi S.,University of Tsukuba | Yasuda K.,National Health Research Institute
Diabetologia | Year: 2014

Aims/hypothesis: The plasticity of adult somatic cells allows for their dedifferentiation or conversion to different cell types, although the relevance of this to disease remains elusive. Perturbation of beta cell identity leading to dedifferentiation may be implicated in the compromised functions of beta cells in diabetes, which is a current topic of islet research. This study aims to investigate whether or not v-Maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MafA), a mature beta cell marker, is involved in maintaining mature beta cell phenotypes.Methods: The fate and gene expression of beta cells were analysed in Mafa knockout (KO) mice and mouse models of diabetes in which the expression of MafA was reduced in the majority of beta cells.Results: Loss of MafA reduced the beta to alpha cell ratio in pancreatic islets without elevating blood glucose to diabetic levels. Lineage tracing analyses showed reduced/lost expression of insulin in most beta cells, with a minority of the former beta cells converted to glucagon-expressing cells in Mafa KO mice. The upregulation of genes that are normally repressed in mature beta cells or transcription factors that are transiently expressed in endocrine progenitors was identified in Mafa KO islets as a hallmark of dedifferentiation. The compromised beta cells in db/db and multiple low-dose streptozotocin mice underwent similar dedifferentiation with expression of Mafb, which is expressed in immature beta cells.Conclusions/interpretation: The maturation factor MafA is critical for the homeostasis of mature beta cells and regulates cell plasticity. The loss of MafA in beta cells leads to a deeper loss of cell identity, which is implicated in diabetes pathology. © 2014, Springer-Verlag Berlin Heidelberg.


Membrane vesicles are tiny spheres that develop from bacterial membranes and contain a mixture of proteins, DNA, and RNA. They are important for the virulence of the bacterium—its ability to cause disease—as they play vital roles in invasion, secretion, and signaling. They also contribute to the formation of biofilms, the slimy three-dimensional structures that form when bacteria adhere to moist surfaces such as teeth or wounds. Extracellular (e)DNA is a key structural organization of biofilms, yet it was not known how certain structural proteins or eDNA are released. To answer this, the researchers used live cell microscopy of the pathogenic bacterium Pseudomonas aeruginosa to reveal that cells quickly changed from rod- to round-shaped, and explode. "Cells lose their structural integrity in 5-10 seconds," corresponding author Cynthia Whitchurch of the University of Technology Sydney explains, "and the explosion releases cellular content including eDNA, proteins, and membrane fragments into the surrounding environment." Using super-resolution microscopy to follow the explosions, they found a surprising observation described by first author Lynne Turnbull: "We observed that membrane fragments produced by exploding bacteria curled up to form membrane vesicles that captured eDNA and other cellular components released by the explosion." Co-corresponding and co-first author Masanori Toyofuku of the University of Tsukuba and University of Zurich explains that, "this was completely unexpected as until now bacterial membrane vesicles were thought to form from membranous protrusions at the cell surface." The team found that the explosions are caused by an enzyme (Lys) used by bacteria-infecting viruses (phages) and phage-like elements to disrupt the cell wall of their hosts. Using a mutant bacterial strain incapable of producing Lys, they discovered that the enzyme was needed to produce eDNA and membrane vesicles. Through a range of experiments, the team also demonstrated that exposure of cells to different forms of stress, such as antibiotics or DNA damaging agents, stimulated expression of the gene encoding Lys and induced explosive cell lysis. "This shows that the bacterial 'SOS' response triggers explosive cell lysis in response to unfavorable environmental conditions," co-corresponding author Leo Eberl of the University of Zurich says. This mechanism may enable bacteria to release important cellular factors for use by bacterial communities as public goods, and knowledge of its control could be used to interfere with biofilm formation of pathogenic bacteria. Explore further: Cells help viruses during cell entry


News Article | January 20, 2016
Site: phys.org

The g-tubulin-specific inhibitor gatastatin (right) developed by the research group from Glaziovianin A (AG1, left) Microtubules, one component of a cell's skeleton, are hollow tubes formed from the polymerization of α- and β-tubulin, which are themselves important structural proteins of the mitotic spindle that equally separates chromosomes during cell division. As such, several α/β-tubulin inhibitory agents are used as therapeutic drugs against cancer cells, which are undergoing vigorous cell division. However, microtubules perform important work even outside of cell division, and normal cells not undergoing division can be harmed as well, so the side effects of such treatments have become problematic. A wide variety of research has shown that γ-tubulin activates during cell division and that it is overexpressed in a portion of cancer cells, so it holds potential as a target protein for new anticancer agents with few side effects. Despite this research, no specific inhibitors have thus far been discovered. University of Tsukuba Faculty of Life and Environmental Sciences Associate Professor Takeo Usui and Researcher Takumi Chinen, and University of Tsukuba Faculty of Pure and Applied Sciences Professor Hideo Kigoshi, in joint research with Heidelberg University, Okayama University, Tokyo University of Pharmacy and Life Sciences, and RIKEN have synthesized and developed the α/β-tubulin inhibitors glaziovianin A and plinabulin, advancing the development of compounds that exhibit γ-tubulin inhibitory activity, and have succeeded in developing the γ-tubulin specific inhibitor gatastatin. Furthermore, using gatastatin their research has shed light on the fact that γ-tubulin function is important in microtubule function in the late stages of cell division. The results of these studies provide knowledge linking to analyses of intracellular γ-tubulin function as well as the development of new anticancer agents. More information: Takumi Chinen et al. The γ-tubulin-specific inhibitor gatastatin reveals temporal requirements of microtubule nucleation during the cell cycle, Nature Communications (2015). DOI: 10.1038/ncomms9722


Yabana K.,University of Tsukuba | Sugiyama T.,University of Tsukuba | Shinohara Y.,University of Tsukuba | Otobe T.,Japan Atomic Energy Agency | Bertsch G.F.,University of Washington
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We apply the coupled dynamics of time-dependent density functional theory and Maxwell equations to the interaction of intense laser pulses with crystalline silicon. As a function of electromagnetic field intensity, we see several regions in the response. At the lowest intensities, the pulse is reflected and transmitted in accord with the dielectric response, and the characteristics of the energy deposition are consistent with two-photon absorption. The absorption process begins to deviate from that at laser intensities of ∼1013 W/cm2, where the energy deposited is of the order of 1 eV per atom. Changes in the reflectivity are seen as a function of intensity. When it passes a threshold of about 3×1012 W/cm2, there is a small decrease. At higher intensities, above 2×1013 W/cm2, the reflectivity increases strongly. This behavior can be understood qualitatively in a model treating the excited electron-hole pairs as a plasma. © 2012 American Physical Society.


Klemm R.A.,University of Central Florida | Kadowaki K.,University of Tsukuba
Journal of Superconductivity and Novel Magnetism | Year: 2010

We calculate the angular dependence of the power of stimulated terahertz amplified radiation (STAR) emitted from a dc voltage applied across a stack of intrinsic Josephson junctions. During coherent emission, we assume that a spatially uniform ac Josephson current density in the stack acts as a surface electric current density antenna source, and the cavity features of the stack are contained in a magnetic surface current density source. A superconducting substrate acts as a perfect magnetic conductor with H ||,ac = 0 on its surface. The combined results agree very well with recent experimental observations. Existing Bi 2Sr 2CaCu 2O 8+δ crystals atop perfect electric conductors could have Josephson STAR-emitter power in excess of 5 mW, acceptable for many device applications. © Springer Science+Business Media, LLC 2010.


Klemm R.A.,University of Central Florida | Kadowaki K.,University of Tsukuba
Journal of Physics Condensed Matter | Year: 2010

The angular dependence of the radiation-zone output power and electric polarization of stimulated terahertz amplified radiation (STAR) emitted from a dc voltage applied across cylindrical and rectangular stacks of intrinsic Josephson junctions is calculated. The boundary conditions are obtained from Love's equivalence principles. During coherent emission, a spatially uniform ac Josephson current density in the stack acts as a surface electric current density antenna source, leading to a harmonic radiation frequency spectrum, as in experiment, but absent in all cavity models of cylindrical mesas. Spatial fluctuations of the ac Josephson current allow its fundamental mode to lock onto the lowest finite energy cylindrical cavity mode, causing it to resonate, leading to a non-uniform magnetic surface current density radiation source, and a non-trivial combined fundamental frequency output power with linear polarization for general radiation directions, which may be fully or partially coherent. The higher ac Josephson harmonics do not excite other cylindrical cavity modes. For rectangular mesas, the lowest energy modes are empirically not excited, but the non-uniform ac Josephson current can excite the harmonic sequence of modes with spatial variation across the rectangular widths, leading to combined radiation outputs both for the fundamental and the higher harmonics, which combinations also may be either fully or partially coherent. The superconducting substrate is modeled as a perfect magnetic conductor, greatly reducing the STAR emitter power and modifying its angular dependence, especially parallel to the substrate. Based upon this substrate model, existing Bi 2Sr2CaCu2O8+ξ crystals atop perfect electric conductors could have STAR emitter power in excess of 5 mW, acceptable for many device applications. © 2010 IOP Publishing Ltd.


Makiuchi T.,Tokai University | Makiuchi T.,Japan National Institute of Infectious Diseases | Nozaki T.,Japan National Institute of Infectious Diseases | Nozaki T.,University of Tsukuba
Biochimie | Year: 2014

The mitochondria have arisen as a consequence of endosymbiosis of an ancestral α-proteobacterium with a methane-producing archae. The main function of the canonical aerobic mitochondria include ATP generation via oxidative phosphorylation, heme and phospholipid synthesis, calcium homeostasis, programmed cell death, and the formation of iron-sulfur clusters. Under oxygen-restricted conditions, the mitochondrion has often undergone remarkable reductive alterations of its content and function, leading to the generation of mitochondrion-related organelles (MROs), such as mitosomes, hydrogenosomes, and mithochondrion-like organelles, which are found in a wide range of anaerobic/microaerophilic eukaryotes that include several medically important parasitic protists such as Entamoeba histolytica, Giardia intestinalis, Trichomonas vaginalis, Cryptosporidium parvum, Blastocystis hominis, and Encephalitozoon cuniculi, as well as free-living protists such as Sawyeria marylandensis, Neocallimastix patriciarum, and Mastigamoeba balamuthi. The transformation from canonical aerobic mitochondria to MROs apparently have occurred in independent lineages, and resulted in the diversity of their components and functions. Due to medical and veterinary importance of the MRO-possessing human- and animal-pathogenic protozoa, their genomic, transcriptomic, proteomic, and biochemical evidence has been accumulated. Detailed analyses of the constituents and functions of the MROs in such anaerobic pathogenic protozoa, which reside oxygen-deprived or oxygen-poor environments such as the mammalian intestine and the genital organs, should illuminate the current evolutionary status of the MROs in these organisms, and give insight to environmental constraints that drive the evolution of eukaryotes and their organelles. In this review, we summarize and discuss the diverse metabolic functions and protein transport systems of the MROs from anaerobic parasitic protozoa. © 2013 The Authors. Published by Elsevier Masson SAS. All rights reserved.


Inagaki T.,University of Tsukuba | Sheridan T.B.,Massachusetts Institute of Technology
Cognition, Technology and Work | Year: 2012

Human-centered automation is an approach to realize a work environment in which humans and machines cooperate. It is usually claimed in the framework that "the human must have final authority over the automation." However, correctness of the statement is context dependent: we note that humans have limited capabilities and authority is interconnected with responsibility. This paper illustrates the need for a machine-initiated trading of authority from humans to automation in the vehicle driving context and clarifies issues to be solved for implementing useful automation invocation based on the machine's interpretation of the situation and the human's behavior. © 2011 Springer-Verlag London Limited.


Jeelani G.,Japan National Institute of Infectious Diseases | Nozaki T.,Japan National Institute of Infectious Diseases | Nozaki T.,University of Tsukuba
Current Opinion in Microbiology | Year: 2014

Entamoeba histolytica is an enteric protozoan parasite that causes hemorrhagic dysentery and extraintestinal abscesses in millions of inhabitants of endemic areas. The genome of E. histolytica has already been sequenced and used to predict the metabolic potential of the organism. Since nearly 56% of the E. histolytica genes remain unannotated, correlative 'omics' analyses of genomics, transcriptomics, proteomics, and biochemical metabolic profiling are essential in uncovering new, or poorly understood metabolic pathways. Metabolomics aims at understanding biology by comprehensive metabolite profiling. In this review, we discuss recent metabolomics approaches to elucidate unidentified metabolic systems of this pathogen and also discuss future applications of metabolomics to understand the biology and pathogenesis of E. histolytica. © 2014 The Authors.


Amoroso D.L.,Kennesaw State University | Magnier-Watanabe R.,University of Tsukuba
Journal of Theoretical and Applied Electronic Commerce Research | Year: 2012

The growth of mobile commerce, or the purchase of services or goods using mobile technology, heavily depends on the availability, reliability, and acceptance of mobile wallet systems. Although several researchers have attempted to create models on the acceptance of such mobile payment systems, no single comprehensive framework has yet emerged. Based upon a broad literature review of mobile technology adoption, a comprehensive model integrating eleven key consumer-related variables affecting the adoption of mobile payment systems is proposed. This model, based on established theoretical underpinnings originally established in the technology acceptance literature, extends existing frameworks by including attractiveness of alternatives and by proposing relationships between the key constructs. Japan is at the forefront of such technology and a number of domestic companies have been effectively developing and marketing mobile wallets for some time. Using this proposed framework, we present the case of the successful adoption of Mobile Suica in Japan, which can serve as a model for the rapid diffusion of such payment systems for other countries where adoption has been unexpectedly slow. © 2012 Universidad de Talca - Chile.


Lu X.,University of Tsukuba | Lu X.,Huazhong University of Science and Technology | Akasaka T.,University of Tsukuba | Nagase S.,Japan Institute for Molecular Science
Angewandte Chemie - International Edition | Year: 2012

Tubular! The detection of a series of very large, soluble endofullerenes extending from La 2C 90 to La 2C 138 proves that endohedral metal doping is an effective strategy for stabilizing these giant molecules. The X-ray structure of the most abundant isomer, La 2@D 5(450)-C 100 (see image), shows a tubular structure featuring a long La-La distance and maximal separation of pentagons within the cage framework. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Maekawa T.,RIKEN | Jin W.,RIKEN | Jin W.,Harvard University | Ishii S.,RIKEN | Ishii S.,University of Tsukuba
Molecular and Cellular Biology | Year: 2010

ATF-2 is a member of the ATF/CREB family of transcription factors and is activated by stress-activated protein kinases, such as p38. To analyze the physiological role of ATF-2 family transcription factors, we have generated mice with mutations in Atf-2 and Cre-bpa, an Atf-2-related gene. The trans-heterozygotes of both mutants were lean and had reduced white adipose tissue (WAT). ATF-2 and CRE-BPa were required for bone morphogenetic protein 2 (BMP-2)-and p38-dependent induction of peroxisome proliferator-activated receptor γ2 (PPARγ2), a key transcription factor mediating adipocyte differentiation. Since stored fat supplies have been recognized as a possible target for antiobesity treatments, we tested whether inhibition of the p38-ATF-2 pathway suppresses adipocyte differentiation and leads to reduced WAT by treating mice with a p38 inhibitor for long periods of time. High-fat diet (HFD)-induced obesity was significantly reduced in mice fed the p38 inhibitor. Furthermore, the p38 inhibitor alleviated HFD-induced insulin resistance. In p38 inhibitor-treated mice, macrophage infiltration into WAT was reduced and the tumor necrosis factor alpha (TNF-α) levels were lower than control mice. Thus, p38 inhibitors may provide a novel antiobesity treatment. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Lu X.,University of Tsukuba | Akasaka T.,University of Tsukuba | Nagase S.,Japan Institute for Molecular Science
Chemical Communications | Year: 2011

Recent breakthroughs achieved in the chemical functionalization of endohedral metallofullerenes (EMFs), especially single crystallographic X-ray characterizations of their derivatives, have presented fundamentally new insights into the structures and properties of these metal-carbon hybrid molecules, and have also brought immense potential applications. In particular, the interplay between the encapsulated metallic species and the fullerene cage has been well investigated. On one hand, the position and motion of the encapsulated metals can be effectively controlled by exohedral modification. On the other hand, the cage structures, the chemical behaviours of cage carbons and thus the chemical reactivity of the whole molecule are also apparently influenced by the electronic configuration and geometrical conformation of the internal metals via strong metal-cage interactions. In this article, we contribute a systematic review of the important chemical transformations of EMFs reported to date, including disilylation, 1,3-dipolar cycloaddition with ylides, cyclopropanation with carbenes and carbanions, cycloaddition with dienes and benzyne, radical reactions, and other miscellaneous reactions, in addition to noncovalent interactions such as supramolecular complexation. The roles that internal metals play in controlling the reactivity of cage carbons are particularly emphasized. Finally, some applicable materials based on EMFs and their derivatives are summarized and practical perspectives are proposed. © 2011 The Royal Society of Chemistry.


Tanikawa A.,RIKEN | Tanikawa A.,University of Aizu | Tanikawa A.,University of Tsukuba
Monthly Notices of the Royal Astronomical Society | Year: 2013

We have performed N-body simulations of globular clusters (GCs) in order to estimate a detection rate of mergers of binary stellar mass black holes (BBHs) by means of gravitational wave (GW) observatories. For our estimate, we have only considered mergers of BBHs which escape from GCs (BBH escapers). BBH escapers merge more quickly than BBHs inside GCs because of their small semimajor axes. N-body simulation cannot deal with a GC with the number of stars N ~ 106 due to its high calculation cost. We have simulated dynamical evolution of small N clusters (104 {similar or less-than} N {similar or less-than} 105), and have extrapolated our simulation results to large N clusters. From our simulation results, we have found the following dependence of BBH properties on N. BBHs escape from a cluster at each two-body relaxation time at a rate proportional to N. Semimajor axes of BBH escapers are inversely proportional to N, if initial mass densities of clusters are fixed. Eccentricities, primary masses and mass ratios of BBH escapers are independent of N. Using this dependence of BBH properties, we have artificially generated a population of BBH escapers from a GC with N ~ 106, and have estimated a detection rate of mergers of BBH escapers by next-generation GW observatories. We have assumed that all the GCs are formed 10 or 12 Gyr ago with their initial numbers of stars Ni = 5 × 105-2 × 106 and their initial stellar mass densities inside their half-mass radii ρh,i = 6 × 103-106M⊙ pc-3. Then, the detection rate of BBH escapers is 0.5-20 yr-1 for a BH retention fraction RBH = 0.5. A few BBH escapers are components of hierarchical triple systems, although we do not consider secular perturbation on such BBH escapers for our estimate. Our simulations have shown that BHs are still inside some of GCs at the present day. These BHs may marginally contribute to BBH detection. © 2013 The Author. Published by Oxford University Press on behalf of the Royal Astronomical Society.


Lu X.,University of Tsukuba | Slanina Z.,University of Tsukuba | Akasaka T.,University of Tsukuba | Tsuchiya T.,University of Tsukuba | And 2 more authors.
Journal of the American Chemical Society | Year: 2010

A series of13C-enriched monoytterbium endohedral metallofullerenes (EMFs)-Yb@C2n (n = 40, 41, 42)-was synthesized and isolated. Their cage structures were systematically determined for the first time using computational and experimental 13C NMR studies. The results revealed that all isomers adopt cage structures conforming to the isolated pentagon rule. In detail, Yb@C80 possesses the C 2v(3) cage; Yb@C82(I, II, III) bear Cs(6), C2(5), and C2v(9) cages, respectively; and Yb@C 84(II, III, IV) have C2(13), C1(12), and C 2(11) cage structures, respectively. This is the first report describing C2(13)-C84 and C1(12)-C84 cage structures. It is noteworthy that the cage structures found for mono-EMFs generally differ from either the corresponding empty fullerenes or the related EMFs encapsulating more than one metal atom, indicating that the metal atom inside the fullerene cage plays an important role in determining the EMF structure. On the basis of the fact that the structure of Yb@C 2(13)-C84 resembles that of Yb@C2(5)-C 82, a metal-templated growth process was proposed as a kinetic factor controlling EMF formation. Furthermore, previous electrochemical studies of divalent EMFs have failed to observe their oxidation potentials, which have raised the assumption that such species are large-bandgap molecules. This study revealed that all isomers of Yb@C2n (n = 40, 41, 42) display one or two reversible oxidation steps together with four reversible reduction processes in 1,2-dichlorobenzene, even at a low scan rate (20 mV/s), which enables estimation of their electrochemical bandgaps (ΔE = oxE 1 - redE1). The results show a ΔE value of 0.88-1.41 V for Yb@C2n (2n = 40, 41, 42), which is much larger than the values of trivalent mono-EMFs (ΔE < 0.5 V), but generally smaller than those of metal nitride cluster EMFs (1.4 V < ΔE < 2.1 V). Results further demonstrated that the ΔE values correlate reasonably with their relative abundances. © 2010 American Chemical Society.


Aoki S.,University of Tsukuba | Hashimoto K.,RIKEN | Iizuka N.,CERN
Reports on Progress in Physics | Year: 2013

We provide, for non-experts, a brief overview of holographic QCD (quantum chromodynamics) and a review of the recent proposal (Hashimoto et al 2010 (arXiv:1003.4988[hep-th])) of a matrix-like description of multi-baryon systems in holographic QCD. Based on the matrix model, we derive the baryon interaction at short distances in multi-flavor holographic QCD. We show that there is a very universal repulsive core of inter-baryon forces for a generic number of flavors. This is consistent with a recent lattice QCD analysis for Nf = 2, 3 where the repulsive core looks universal. We also provide a comparison of our results with the lattice QCD and the operator product expansion analysis. © 2013 IOP Publishing Ltd.


Hall D.,University of Tsukuba | Edskes H.,U.S. National Institute of Diabetes and Digestive and Kidney Diseases
Biophysical Reviews | Year: 2012

Amyloid is the name given to a special type of linear protein aggregate that exhibits a common set of structural features and dye binding capabilities. The formation of amyloid is associated with over 27 distinct human diseases which are collectively referred to as the amyloidoses. Although there is great diversity amongst the amyloidoses with regard to the polypeptide monomeric precursor, targeted tissues, and the nature and time course of disease development, the common underlying link of a structurally similar amyloid aggregate has prompted the search for a unified theory of disease progression in which amyloid production is the central element. Computational modeling has allowed the formulation and testing of scientific hypotheses for exploring this relationship. However, the majority of computational studies on amyloid aggregation are pitched at the atomistic level of description, in simple ideal solution environments, with simulation time scales of the order of microseconds and system sizes limited to 100 monomers (or fewer). The experimental reality is that disease-related amyloid aggregation processes occur in extremely complex reaction environments (i. e. the human body), over time scales of months to years with monitoring of the reaction achieved using extremely coarse or indirect experimental markers that yield little or no atomistic insight. Clearly, a substantial gap exists between computational and experimental communities with a deficit of 'useful' computational methodology that can be directly related to available markers of disease progression. This review will place its focus on the development of these latter types of computational models and discuss them in relation to disease onset and progression. © 2012 Springer-Verlag (outside the USA).


Rutkowski T.M.,University of Tsukuba | Rutkowski T.M.,RIKEN
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

The paper discusses novel and interesting, from users' point of view, design of auditory brain-computer/machine interfaces (BCI/ BMI) utilizing human auditory responses. Two concepts of auditory stimuli BCI/BMI are presented. The first paradigm is based on steady-state tonal or musical stimuli yielding satisfactory EEG response classification for several seconds long stimuli. The second discussed paradigm is based on spatial sound localization and the brain evoked responses estimation, requiring shorter than a second stimuli presentation. In conclusion the preliminary results are discussed and suggestions for further applications are drawn. © 2011 Springer-Verlag.


Shimizu Y.,RIKEN | Kuramashi Y.,RIKEN | Kuramashi Y.,University of Tsukuba
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

The lattice regularized Schwinger model with a so-called θ term is studied by using the Grassmann tensor renormalization group. We perform the Lee-Yang and Fisher zero analyses in order to investigate the phase structure at θ=π. We find a first-order phase transition at larger fermion mass. Both the Lee-Yang zero and Fisher zero analyses indicate that the critical endpoint at which the first-order phase transition terminates belongs to the Ising universality class. © 2014 American Physical Society.


Ozawa T.,University of Tsukuba | Ozawa T.,RIKEN | Yamada K.,University of Tsukuba | Ichitani Y.,University of Tsukuba
Behavioural Brain Research | Year: 2014

In order to investigate the role of brain-derived neurotrophic factor (BDNF) in the consolidation of spatial memory, we examined the relationship between the increase of hippocampal BDNF and the establishment of long-term spatial memory in spontaneous place recognition test in rats. The test consisted of a sample phase, delay interval, and a test phase, and preferred exploration of the object in a novel place compared with that in a familiar place was assessed in the test phase. In experiment 1, dorsal hippocampal administration of anisomycin, a protein synthesis inhibitor, before the sample phase (20. min) abolished the preference for the novel place object in the test phase conducted 24. h later. This impairment was reversed by the dorsal hippocampal BDNF treatment immediately after the sample phase, although the BDNF treatment alone did not improve performance. In experiment 2, we used a shorter sample phase condition (5. min) in which control rats did not show any preference for the novel place object in the test phase after 24. h delay, and found that BDNF treatment immediately after the sample phase caused rats' significant preference for it. Results suggest an important role of hippocampal BDNF as a product of protein synthesis that is required for the consolidation of spatial memory. © 2014 Elsevier B.V.


Yamada M.,University of Tsukuba | Yamada M.,Japan Institute for Molecular Science | Akasaka T.,University of Tsukuba | Akasaka T.,Japan Institute for Molecular Science | And 2 more authors.
Accounts of Chemical Research | Year: 2010

(Figure Presented) Fullerene, an allotropie form of carbon made up of spherical molecules formed from pentagonal and hexagonal rings, was first discovered in 1985. Because fullerenes have spacious inner cavities, atoms and clusters can be encapsulated inside the fullerene cages to form endohedral fullerenes. In particular, the unique structural and electronic properties of endohedral metallofullerenes (EMFs), where metal atoms are encapsulated within the fullerene, have attracted wide interest from physicists and chemists as well as materials scientists and biologists. The remarkable characteristics of these molecules originate in the electron transfer from the encapsulated metal atoms to the carbon cage. The positions and movements of the encapsulated metal atoms are important determinants of the chemical and physical properties of EMFs. In this Account, we specifically describe the positions and dynamic behavior of the metal atoms encapsulated in pristine and functionalized fullerene cages. First, we examined whether the metal atoms are attached rigidly to cage carbons or move around. Our systematic investigations of EMFs, including M@c 2v,-C82, M2@D2(10611)-C 72, M2(5)D3h(S)-C78, M 2@lh-C80, and M2@D 5h-C80, revealed that the metal positions and movements vary widely with different cage structures and numbers of metal atoms. Second, we wanted to understand whether we could control the positions and movements of the untouchable metal atoms in EMFs. One possible way to modulate this behavior was through attachment of a molecule to the outer surface of the cage. We developed synthetic methods to modify EMFs and have examined the metal positions and movements in the functionalized carbon cages. Remarkably, we could alter the dynamic behavior of the encaged metal atoms in M2@l h-C80 drastically through chemical modification of the outer cage. We anticipate that the control of metal atom structures and dynamics within a cage could be valuable for designing functional molecular devices with new electronic or magnetic properties. © 2010 American Chemical Society.


Inakura T.,RIKEN | Nakatsukasa T.,RIKEN | Nakatsukasa T.,University of Tsukuba | Yabana K.,RIKEN | Yabana K.,University of Tsukuba
Physical Review C - Nuclear Physics | Year: 2011

The pygmy dipole resonances (PDR) for even-even nuclei in 8≤Z≤40 are studied performing a systematic calculation of the random-phase approximation with the Skyrme functional of SkM*. The calculation is fully self-consistent and does not assume any symmetry in the nuclear shape of the ground state. In every isotopic chain, the PDR emerges by showing a peak of the E1 strength at energies less than 10 MeV. The E1 strength of the PDR strongly depends on the position of the Fermi level and shows a clear correlation with the occupation of the orbits with the orbital angular momenta less than 3 (≤2). We also found a strong correlation between the isotopic dependence of the neutron skin thickness and the pygmy dipole strength. The fraction of the energy-weighted strength exhausted by the PDR and the neutron skin thickness show a linear correlation with the universal rate of about 0.2 fm-1. © 2011 American Physical Society.


Avogadro P.,Texas A&M University-Commerce | Avogadro P.,RIKEN | Nakatsukasa T.,RIKEN | Nakatsukasa T.,University of Tsukuba
Physical Review C - Nuclear Physics | Year: 2013

We present an efficient numerical technique to evaluate the matrix of the (quasiparticle-) random-phase approximation, using the finite-amplitude method (FAM). The method is tested in calculation of monopole excitations in 120Sn, compared with result obtained with the former iterative FAM. The neutron-pair-transfer modes are calculated with the present method and their character change in neutron-rich Pb isotopes is discussed. Computational aspects of different FAM approaches are also discussed for future applications to a large-scale computation. © 2013 American Physical Society.


Ishizuka T.,Tokyo University of Science | Ishizuka T.,RIKEN | Xu Y.,University of Miyazaki | Komiyama M.,Tokyo University of Science | Komiyama M.,University of Tsukuba
Journal of the American Chemical Society | Year: 2013

The understanding of telomeres is expected to provide major insights into genome stability, cancer, and telomere-related diseases. In recent years, there have been considerable improvements in the technologies available to determine the length of telomeres of human chromosomes; however, the present methods for measuring telomere length are fraught with shortcomings that have limited their use. Here we describe a method for detection of individual telomere lengths (DITL) that uses a chemistry-based approach that accurately measures the telomere lengths from individual chromosomes. The method was successfully used to determine telomere DNA by breaking in the target sequence and producing a "real telomere fragment." The DITL approach involves cleavage of the sequence adjacent to the telomere followed by resolution of the telomere length at the nucleotide level of a single chromosome. Comparison of the DITL method and the traditional terminal restriction fragment (TRF) analysis indicates that the DITL approach appears to be promising for the quantification of telomere repeats in each chromosome and the detection of accurate telomere lengths that can be missed using TRF analysis. © 2012 American Chemical Society.


Shimizu Y.,RIKEN | Kuramashi Y.,RIKEN | Kuramashi Y.,University of Tsukuba
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We apply the Grassmann tensor renormalization group to the lattice regularized Schwinger model with one-flavor of the Wilson fermion. We study the phase diagram in the (β,κ) plane performing a detailed analysis of the scaling behavior of the Lee-Yang zeros and the peak height of the chiral susceptibility. Our results strongly indicate that the whole range of the phase transition line starting from (β,κ)=(0.0,0.380665(59)) and ending at (0.25) belongs to the two-dimensional Ising universality class similar to the free fermion case. © 2014 American Physical Society.


Patent
University of Tsukuba and Riken | Date: 2016-10-19

Provided is a plant such as tomato, in which plant vigor has been increased and heat resistance has further been imparted. A plant such as tomato can be obtained, which has increased the stem diameter as well as the plant height and has become heat resistant by having a mutant Della protein, in which a leucine corresponding to the leucine at position 567 in SEQ ID NO: 2 in the amino acid sequence of the Della protein has been replaced by another amino acid, preferably phenylalanine.


Hayashi Y.,University of Tsukuba | Hayashi Y.,Japan Science and Technology Agency | Kashiwagi M.,University of Tsukuba | Yasuda K.,RIKEN | And 4 more authors.
Science | Year: 2015

Mammalian sleep comprises rapid eye movement (REM) sleep and non-REM (NREM) sleep.To functionally isolate from the complex mixture of neurons populating the brainstem pons those involved in switching between REM and NREM sleep, we chemogenetically manipulated neurons of a specific embryonic cell lineage in mice.We identified excitatory glutamatergic neurons that inhibit REM sleep and promote NREM sleep. These neurons shared a common developmental origin with neurons promoting wakefulness; both derived from a pool of proneural hindbrain cells expressing Atoh1 at embryonic day 10.5.We also identified inhibitory γ-aminobutyric acid-releasing neurons that act downstream to inhibit REM sleep. Artificial reduction or prolongation of REM sleep in turn affected slow-wave activity during subsequent NREM sleep, implicating REM sleep in the regulation of NREM sleep.


Ogura Y.,University of Tsukuba | Ogura Y.,RIKEN | Sasakura Y.,University of Tsukuba
Developmental Cell | Year: 2016

During neurulation of chordate ascidians, the 11th mitotic division within the epidermal layer shows a posterior-to-anterior wave that is precisely coordinated with the unidirectional progression of the morphogenetic movement. Here we show that the first sign of this patterned mitosis is an asynchronous anterior-to-posterior S-phase length and that mitotic synchrony is reestablished by a compensatory asynchronous G2-phase length. Live imaging combined with genetic experiments demonstrated that compensatory G2-phase regulation requires transcriptional activation of the G2/M regulator cdc25 by the patterning genes GATA and AP-2. The downregulation of GATA and AP-2 at the onset of neurulation leads to loss of compensatory G2-phase regulation and promotes the transition to patterned mitosis. We propose that such developmentally regulated cell-cycle compensation provides an abrupt switch to spatially patterned mitosis in order to achieve the coordination between mitotic timing and morphogenesis. © 2016 Elsevier Inc.


Mizuno S.,University of Tsukuba | Mizuno S.,RIKEN
Nuclear Physics A | Year: 2014

Direct photons coming from heavy-ion collisions are of particular interest since once produced, they are unmodified, thus carrying information about the space-time evolution and properties of the hot and dense medium produced in such collisions. We present new results on the centrality dependence of soft single photon production in √sNN=200GeV Au+Au collisions. Photons are measured down to pT=400GeV/c via conversion of real photons into e+e- pairs in the detector material. Our measurement of the photon pT spectra indicates that the spectral shape does not depend on centrality. In addition, the azimuthal emission patterns of photons carry additional information on their production mechanisms. Previously published PHENIX results [2] indicate that the 2nd order Fourier coefficient (v2) is positive for pT<4GeV/c, which is qualitatively explained by hydrodynamical model calculations, but not quantitatively. The 3rd order Fourier coefficient (v3) of photons has been proposed as a critical additional handle to understand the photon emission. We found that the v3 of photons is positive for pT<4GeV/c, and both the strength and shape of v3 are comparable to those of hadrons, similarly to the case of v2. We report the latest results on the centrality dependence of the soft photon production and the v3 coefficients in Au+Au collisions at √sNN=200GeV. These measurements provide stringent tests of the hydrodynamic space-time evolution as a function of the collision geometry. © 2014 Elsevier B.V.


Patent
Yokohama City University and University of Tsukuba | Date: 2011-09-21

The present invention aims to express influenza virus RNA polymerase on a large scale, to crystallize the influenza virus RNA polymerase, and to provide a method for screening a substance capable of serving as an active ingredient in anti-influenza drugs. The present invention provides a complex comprising a polypeptide consisting of an amino acid sequence at positions 678-757 of the RNA polymerase PB1 subunit in influenza A/Puerto Rico/8/34 H1N1 and a polypeptide consisting of an amino acid sequence at positions 1-37 of RNA polymerase PB2 subunit in influenza A/Puerto Rico/8/34 H1N1. This complex can be crystallized in the presence of a precipitant such as potassium phosphate and PEG4000. Moreover, with the use of information on the crystal structure of this complex, it is possible to provide a method for screening a substance capable of serving as an active ingredient in anti-influenza drugs.


The present invention aims to express influenza virus RNA polymerase on a large scale, to crystallize the influenza virus RNA polymerase, and to provide a method for screening a substance capable of serving as an active ingredient in anti-influenza drugs which target a protein highly conserved among influenza virus species. The present invention provides a complex comprising a polypeptide consisting of an amino acid sequence at positions 239-716 of the RNA polymerase PA subunit in influenza A/Puerto Rico/8/1934 H1N1 and a polypeptide consisting of an amino acid sequence at positions 1-81 of the RNA polymerase PB1 subunit in influenza A/Puerto Rico/8/1934 H1N1, as well as a method for screening a substance capable of serving as an active ingredient in anti-influenza drugs, which comprises the step of selecting a substance which inhibits the interaction between -subunit and -subunit 1, each constituting influenza virus RNA polymerase, in the presence of a candidate substance.


Provided is a strain belonging to the genus Aurantiochytrium, the strain being characterized by there being at least 10 mass% of squalene in all the lipids produced by the strain, and by forming colonies exhibiting an orange-to-red color.


Patent
Hokkaido University, Japan Bcg Laboratory, University of Tsukuba and University of Tokyo | Date: 2013-08-27

[Problem] To provide: a lipid membrane structure which has such a particle diameter that the lipid membrane structure can be sterilized by filtration, contains a lipid that is bound to a peptide composed of multiple arginine residues as a constituent lipid, and includes a bacterial cell component having dispersibility in a non-polar solvent; and a method for producing a lipid membrane structure which has such a particle diameter that the lipid membrane structure can be sterilized by filtration and includes a substance of interest having dispersibility in a non-polar solvent. [Solution] A lipid membrane structure which has such a particle diameter that the lipid membrane structure can be sterilized by filtration, contains a lipid that is bound to a peptide composed of multiple arginine residues as a constituent lipid, and includes a bacterial cell component having dispersibility in a non-polar solvent.


Patent
University of Tsukuba, Kochi University of Technology and Tokai University | Date: 2014-06-04

The present invention is provided with: a data-driven processor (21) comprising at least a firing control (32) which determines whether or not firing conditions have been met by determining whether or not all packets necessary for instruction execution have been received when a packet that convey a part of partitioned data to be processed has been input, and a data processing unit (37) for performing processing corresponding to the packets transmitted from the firing control (32) if the firing conditions have been met; a power supply circuit (57) for supplying power to the data-driven processor (21); and overload avoidance means (23) for refusing input of the packets to the data-driven processor (21), if a determination has been made that a data processing load in the data-driven processor (21) may reach an overloaded state in which the data processing may stall, on the basis of current consumption (Iss) in the data-driven processor (21). Accordingly, power consumption in a networking system (S) is reduced.


Patent
Hokkaido University, University of Tokyo, University of Tsukuba and Japan Bcg Laboratory | Date: 2015-07-08

[Problem] To provide: a lipid membrane structure which has such a particle diameter that the lipid membrane structure can be sterilized by filtration, contains a lipid that is bound to a peptide composed of multiple arginine residues as a constituent lipid, and includes a bacterial cell component having dispersibility in a non-polar solvent; and a method for producing a lipid membrane structure which has such a particle diameter that the lipid membrane structure can be sterilized by filtration and includes a substance of interest having dispersibility in a non-polar solvent. [Solution] A lipid membrane structure which has such a particle diameter that the lipid membrane structure can be sterilized by filtration, contains a lipid that is bound to a peptide composed of multiple arginine residues as a constituent lipid, and includes a bacterial cell component having dispersibility in a non-polar solvent.


Patent
University of Tsukuba and Riken | Date: 2014-11-07

Provided is a plant such as tomato, in which plant vigor has been increased and heat resistance has further been imparted. A plant such as tomato can be obtained, which has increased the stem diameter as well as the plant height and has become heat resistant by having a mutant Della protein, in which a leucine corresponding to the leucine at position 567 in SEQ ID NO: 2 in the amino acid sequence of the Della protein has been replaced by another amino acid, preferably phenylalanine.


News Article | February 21, 2017
Site: www.eurekalert.org

Tsukuba, Japan - A key factor to improve swimming performance is reducing resistance that water exerts on the moving body. This resistance, known as drag, is influenced by factors including the stroke rate, swimmer's size, and swimming speed. The range of factors, along with the motion of the swimmer, have made it difficult to measure drag accurately. In an advance that could help modify training practices in the swimming world, a research team centered at the University of Tsukuba (Japan) has developed a new method and apparatus to measure drag in a water flume. The method overcomes the disadvantages of earlier approaches, such as their not being applicable to different swimming strokes or only being functional at full speed, and showed good reliability in applied tests. The new approach involves connecting a swimmer in a water flume to load cells at the front and back of the flume. This allows the force in each direction to be calculated relative to maintaining a fixed position by swimming at the same speed as the flow in the flume, thereby allowing the residual thrust to be determined. This can then be compared to a passive state when being towed motionless through the water. "We set six swimmers up in the apparatus and applied different water flow rates to them, while using an underwater metronome to ensure they maintained the required stroke rate," study corresponding author Hideki Takagi says. "We were also able to compare the active drag they were subjected to with passive drag when they were pulled through the water while adopting streamlined positions." The results for active drag showed low variability, suggesting the approach's reliability. The finding that active drag exceeded passive drag also suggests the study's validity, despite this finding not being made in some previous work, because the area of the front of the body when moving through the water is larger when a swimming stroke is being performed. "We expect this methodology to be greatly beneficial in reducing drag and improving swimming times among elite swimmers," lead author Kenzo Narita says. "The effects of minor adjustments in swimming posture can now be precisely determined." The team hopes to build on this study by clarifying the factors that influence active drag and by applying this methodology alongside measurements of swimming efficiency, such as by measuring oxygen intake. The article "Developing a methodology for estimating the drag in front-crawl swimming at various velocities" was published in Journal of Biomechanics at DOI: 10.1016/j.jbiomech.2017.01.037


News Article | February 6, 2016
Site: www.nanotech-now.com

Home > Press > Discovery of the specific properties of graphite-based carbon materials Abstract: University of Tsukuba Faculty of Pure and Applied Sciences Associate Professor Takahiro Kondo and Professor Junji Nakamura, in cooperation with Researcher Donghui Guo and Professor Susumu Okada of the same faculty, have shown from detailed measurements that in atomically flat areas of a nitrogen-doped graphite surface in the absence of external magnetic fields, Landau levels manifest corresponding to super strong magnetic fields of approximately 100 tesla across bilayer graphene. There has been some debate thus far that the source of Landau levels generated under non-magnetic fields has been pseudo-magnetic fields induced by asymmetries, but in this study the researchers observed Landau levels on atomically flat surfaces without asymmetries, showing for the first time the existence of Landau levels generated by sources other than asymmetries. These results further endorse the "domain model" (the mechanism for Landau level generation under a non-magnetic field) that this same research team has advocated for in the past, and newly reveals the unique properties of graphite-based carbon materials such as graphene, which could be used as new materials in electronic devices or for catalysis. Graphite-based carbon materials such as graphene exhibit powerful electrical conductivity and excellent strength in small quantities, so there is hope that they may contribute to next-generation materials in a variety of fields. The discovery of new physical properties of carbon materials in this study could lead to new applications in environmental materials like electronic materials that make use of electronic state controls such as band gap controls, catalysts, or batteries. If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


Sivasubramanian V.,Indira Gandhi Center for Atomic Research | Kojima S.,University of Tsukuba
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

Brillouin spectra measurements have been carried out from 800 to 100 K for Pb(Sc 1/2Ta 1/2)O 3 in back-scattering geometry. The frequency of the longitudinal acoustic (LA) phonon begins to show marked softening followed by an increase in its width below the intermediate temperature T * = 450 K. The gradual increase in the width of the LA phonon below T * is attributed to the electrostrictive coupling between the local polarization and strain. The frequency of the LA phonon mode exhibits anomalous behavior around 295 K, the phase transition temperature. The width of the LA phonon exhibits a sharp Landau-Khalatnikov-like maximum at 295 K. A central peak begins to appear around T * and exhibits critical slowing down upon further cooling. The relaxation times calculated for the LA phonon and central peak indicate the order-disorder nature of the phase transition. © 2012 American Physical Society.


Maruyama H.,University of Tsukuba | Nakano H.,Toyota Central R&D Labs. | Nakamoto M.,University of Tsukuba | Sekiguchi A.,University of Tsukuba
Angewandte Chemie - International Edition | Year: 2014

The development of electrical energy storage devices that can operate at high charge and discharge rates is fundamentally important, however although electrochemical capacitors (ECs) can charge and discharge at high rates, their electrochemical storage capacity remains an order of magnitude lower than that of conventional lithium-ion batteries. Novel pseudocapasitors are developed, based on the stable persilyl-susbtituted free radicals of the heavy group 14 elements, (tBu2MeSi)3EC [E=Si (1), Ge (2), and Sn (3)], as anode materials for energy storage system. Such systems showed a remarkable cycle stability without significant loss of power density, in comparison with similar characteristics of the known organic radical batteries, the dual carbon cell, and the electrochemical capacitor. Particularly important is that these novel electrochemical energy storage systems employing stable heavy group 14 element radicals are lithium-free. The electrochemical properties and structures of the reduced and oxidized species were studied by the cyclic voltammetry (CV), electron paramagnetic resonance (EPR) spectroscopy, and X-ray diffraction (XRD). © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Lei Z.,Fudan University | Chen J.,Fudan University | Zhang Z.,University of Tsukuba | Sugiura N.,University of Tsukuba
Bioresource Technology | Year: 2010

Rice straw particles were directly used as substrate for anaerobic digestion with acclimated sludge under room temperature and different levels of phosphate. Two obvious biogas production peaks were observed for all reactors, with biogas or methane yields of (0.33-0.35) m3/kg-VS loaded or (0.27-0.29) m3 CH4/kg-VS loaded and average methane contents of 75.9-78.2%. A separated two-stage first-order kinetic model was developed in this study and showed a good fit to the experimental data when this complicated process was divided into two stages. The average biogas and methane production rate constants were (0.027-0.031) d-1 and (0.028-0.033) d-1, respectively, increased by 2-3 times in the second stages than those in the first. The results indicated that an adequate level of phosphate addition (465 mg-P/L) could accelerate the biogasification process: 7-13 days earlier appearance of the two peaks and shorter time needed for complete biogasification of rice straw. © 2010 Elsevier Ltd. All rights reserved.


Professor Hideki Takagi, at the Faculty of Health and Sport Sciences at the University of Tsukuba and his colleagues, through joint research with Descente Ltd., have succeeded in developing a new high-performance swimsuit with a "kick assist system" that improves the power of the dolphin kick. High-speed swimsuits, which made their appearance at the 2008 Olympics in Beijing, were the driving force behind a barrage of new world records. However, the International Swimming Federation changed the rules significantly in 2010 due to a concern that swimming races were not being won by superior swimming techniques but by superior swimsuits, and the ruling body imposed strict regulations. These restrictions greatly narrowed the scope of swimsuit development and all but eliminated hope for improving swimsuit performance. To make a breakthrough under these conditions, the research group went back to the drawing board and put their heads together to figure out what exactly about a swimsuit allows a swimmer to go faster. They came up with these questions: "What are the characteristics of the swimming motions of the most elite competitive swimmers?" and "What kind of performance does a swimsuit need to have for it to facilitate non-elite swimmers in trying to achieve that motion?" Based on these two perspectives, the lab then began developing new high-performance swimsuits. To elucidate the motions used in fast swimming, a state-of-the-art underwater motion analysis system and underwater myoelectric analysis system at the University of Tsukuba were put to use. It was decided to narrow the focus of the swimming motion to the dolphin kick used by nearly all swimmers at the start of a race and after turns. Once they had analyzed the characteristics of the dolphin kick of the most elite competitive swimmers, they began looking into material development, shapes, and designs, etc., to give swimsuits the performance needed to assist that motion. The new swimsuit produced from this research is due to be released as Aquaforce Lightning, under the Arena brand. Explore further: ISU professor helps design new Speedo swimsuit that's breaking world records


The research group of Professor Hiroaki Misawa of Research Institute for Electronic Science, Hokkaido University and Assistant Professor Atsushi Kubo of the Faculty of Pure and Applied Sciences, University of Tsukuba, have successfully observed the dephasing time of the two different types of collective motions of electrons generated on the surface of a gold nanoparticle for the first time in the world, by combining a laser that emits ultrashort light pulses with a photoemission electron microscope.


Matsuura T.,Japan Forestry and Forest Products Research Institute | Aniya M.,University of Tsukuba
Geomorphology | Year: 2012

We developed a three-step algorithm to automate the recognition and segmentation of hillslopes across ridges and valleys using a gridded digital elevation model (DEM). The first step involves the delineation of a side-slope profile by locating the lower and upper boundaries. In the second step, the cross-profile pattern of a ridge or a valley floor, which is defined and bounded by a pair of side slopes, is examined in order to distinguish upland flats from ridges and lowlands from valley floors. The width and gradient of these landform units are also measured. In the third step, a side-slope profile is segmented into lower, mid-, and upper slopes, with a line-simplification algorithm to identify changes and breaks in the slope. In this step, the footslope and crestslope can also be distinguished within the lower and upper slopes, respectively. Using a 15-m DEM, this method was applied to five sites in low- to high-relief fluvial landscapes in Japan. The results showed good agreement (86.9. ±. 2.7%) with manual slope segmentation, indicating the effectiveness of our algorithm. © 2012 Elsevier B.V.


Yu H.,Japan National Institute of Advanced Industrial Science and Technology | Guo S.,Japan National Institute of Advanced Industrial Science and Technology | Guo S.,University of Tsukuba | Zhu Y.,Japan National Institute of Advanced Industrial Science and Technology | And 3 more authors.
Chemical Communications | Year: 2014

O3-type NaTi0.5Ni0.5O2 is explored as a titanium-based cathode material for sodium ion batteries. It delivers a reversible capacity of 121 mA h g-1 at 0.2 C with smooth charge-discharge curves, and exhibits excellent cycling stability and good rate capability, indicating its superiority as a promising candidate electrode material for sodium ion batteries. © 2014 The Royal Society of Chemistry.


Tanoi T.,Japan National Institute of Environmental Studies | Kawachi M.,Japan National Institute of Environmental Studies | Watanabe M.M.,University of Tsukuba
Journal of Applied Phycology | Year: 2011

The green colonial alga Botryococcus braunii is characterized by the ability to produce and accumulate large amounts of hydrocarbons. We isolated and established an axenic clonal strain of B. braunii B70 and investigated the effects of organic carbon sources, including glucose, mannose, fructose, galactose, or acetate, on growth under light and dark conditions. This algal strain had the capacity to grow photo-, mixo-, or heterotrophically. Growth was promoted substantially following exposure of the algae to glucose or mannose under light exposure. Cells could grow under continuous darkness with glucose or mannose. In the presence of glucose under light or dark conditions, cell and colony size, and the intracellular granules containing oil, were markedly larger than those cultured without glucose. © 2010 Springer Science+Business Media B.V.


Yamaguchi T.,University of Tsukuba | Sekiguchi A.,University of Tsukuba | Driess M.,TU Berlin
Journal of the American Chemical Society | Year: 2010

The reaction of disilyne 1 with 1,3,4,5-tetramethylimidazol-2-ylidene (an N-heterocyclic carbene, NHC) produced the disilyne-NHC complex 2, RLSi SiR: (R = SiiPr[CH(SiMe3)2]2, L = NHC), with a trans geometry of the Si Si moiety and lone-pair electrons residing on one of the double-bonded Si atoms. Upon complexation of 2 with ZnCl2, the disilyne-NHC-ZnCl2 complex 3 was produced, in which the Si Si bond adopted the cis geometry. © 2010 American Chemical Society.


Lu X.,Huazhong University of Science and Technology | Lu X.,University of Tsukuba | Feng L.,University of Tsukuba | Feng L.,Soochow University of China | And 2 more authors.
Chemical Society Reviews | Year: 2012

Endohedral metallofullerenes (EMFs), a new class of hybrid molecules formed by encapsulation of metallic species inside fullerene cages, exhibit unique properties that differ distinctly from those of empty fullerenes because of the presence of metals and their hybridization effects via electron transfer. This critical review provides a balanced but not an exhaustive summary regarding almost all aspects of EMFs, including the history, the classification, current progress in the synthesis, extraction, isolation, and characterization of EMFs, as well as their physiochemical properties and applications in fields such as electronics, photovoltaics, biomedicine, and materials science. Emphasis is assigned to experimentally obtained results, especially the X-ray crystallographic characterizations of EMFs and their derivatives, rather than theoretical calculations, although the latter has indeed enhanced our knowledge of metal-cage interactions. Finally, perspectives related to future developments and challenges in the research of EMFs are proposed. (381 references) This journal is © The Royal Society of Chemistry 2012.


Kondo S.-I.,Yamagata University | Bie Y.,Yamagata University | Yamamura M.,University of Tsukuba
Organic Letters | Year: 2013

Two silanediol derivatives bearing 9-anthryl (2) and 1-pyrenyl (3) groups have been developed for fluorescence detection of anions. Receptor 3 showed favorable ratiometric response by fluorescence spectroscopy upon the addition of biologically relevant anions, such as acetate and dihydrogen phosphate in acetonitrile. © 2013 American Chemical Society.


Arai T.,University of Tsukuba | Arai T.,Tokyo Metropolitan Institute of Medical Science
Neuropathology | Year: 2014

Based on the cerebral tans-activation response DNA protein 43 (TDP-43) immunohistochemistry, frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP) is classified into four subtypes: type A has numerous neuronal cytoplasmic inclusions (NCIs) and dystrophic neurites (DNs); type B has numerous NCIs with few DNs; type C is characterized by DNs which are often longer and thicker than DNs in type A, with few NCIs; and type D has numerous neuronal intranuclear inclusions and DNs with few NCIs. The relevance of this classification system is supported by clinical, biochemical and genetic correlations, although there is still significant heterogeneity, especially in cases with type A pathology. The subtypes of TDP-43 pathology should be determined in cases with other neurodegenerative disorders, including Alzheimer's disease and dementia with Lewy bodies, to evaluate the pathological significance of TDP-43 abnormality in them. The results of the biochemical analyses of the diseased brains and the cellular models suggest that different strains of TDP-43 with different conformations may determine the clinicopathological phenotypes of TDP-43 proteinopathy, like prion disease. Clarifying the mechanism of the conformational changes of TDP-43 leading to the formation of multiple abnormal strains may be important for differential diagnosis and developing disease-modifying therapy for TDP-43 proteinopathy. © 2014 Japanese Society of Neuropathology.


Watanabe K.,Kyoto University | Osaka I.,University of Tsukuba | Yorozuya S.,University of Tsukuba | Akagi K.,Kyoto University
Chemistry of Materials | Year: 2012

Novel derivatives of polythiophenes and their phenylene copolymers were synthesized by introducing chiral alkoxy carbonyl substituents into their side chains. Most of these polymers showed enantiotropic main-chain liquid crystallinity at high temperatures and across a wide range of elevated temperatures. They exhibited fluorescence that ranged in color from blue to orange in chloroform solutions and from blue to red in films. The bisignate Cotton effect was observed in the π-π* transition region of the circular dichroism (CD) spectra of the polymers consisting of three aromatic rings in the repeating unit, which was attributed to the formation of a polymer assembly with an interchain helically π-stacked structure. The dependence of UV-vis absorption and CD spectra on the concentration and temperature of the solution indicated that the polymer assembly exists, even in dilute concentration at room temperature, but it dissociated into single polymers at high temperatures. Additionally, the polymer films exhibited an enhanced Cotton effect caused by the strengthening of the helical π-stacking in the polymer assembly. Both the polymer solutions and films generated circularly polarized fluorescence with values for g em, the dissymmetry factor, on the order of 10 -3 and 10 -2, respectively. Values for g em as high as 10 -1 were obtained by annealing the polymer films at temperatures corresponding to the liquid crystalline region and were due to the self-ordering of their chiral nematic phases. Furthermore, a mixture of red, green, and blue fluorescent polymers generated a unique, circularly polarized white luminescence not only in solution but also in the cast film prepared by dispersing the mixture in an excess of polystyrene. © 2012 American Chemical Society.


Kijima M.,University of Tsukuba | Hirukawa T.,University of Tsukuba | Hanawa F.,University of Tsukuba | Hata T.,Kyoto University
Bioresource Technology | Year: 2011

Alkaline lignin was thermally converted to microporous carbon in ca. 50% yield by heating up from room temperature to 900°C without activation process under flowing of an argon gas. The carbonized material prepared by heating up conditions of 1°Cmin-1 showed 530m2/g of the Brunauer-Emmett-Teller (BET) specific surface area, which increased to 740m2/g after washing with water. Furthermore, alkaline lignin derivatives were structured as micron scale particles by micelle formation and polymer gelation techniques. Carbonization of the structured lignins could afford high porous materials having BET surface areas above 1000m2/g without surface activation processes. © 2011 Elsevier Ltd.


Han B.,University of Tsukuba | Li J.,University of Tsukuba | Su J.,National University of Defense Technology | Cao J.,Hong Kong Polytechnic University
IEEE Journal on Selected Areas in Communications | Year: 2012

One of the challenging issues for supporting emergency services in wireless networks is coordinating the network under emergent situations. Cooperative communication (CC) is a promising approach which can offer significant enhancements in multi-hop wireless networks. This paper investigates the potential issues in using this communication paradigm to support emergency services. We focus on promoting energy-efficient and congestion-aware cooperative networking for emergency services based on the idea of Do-It-Yourself. We propose a novel cross-layer design which jointly considers the problems of route selection in network layer, congestion and non-cooperation avoidance among multiple links in MAC layer under cooperative multi-hop wireless environments. We formulate the multi-hop cooperative flow routing and relay node selection process as an optimization problem. Based on the formulations and models, we propose a self-supported networking scheme including three novel components that make the solution procedure highly efficient. Analysis and simulation results show that our approaches significantly achieve better network performance and typically satisfy the requirements for emergency services in multi-hop wireless networks. © 2006 IEEE.


Ishiki G.,University of Tsukuba | Ishiki G.,Kyoto University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We propose a novel method of finding the classical limit of the matrix geometry. We define coherent states for a general matrix geometry described by a large-N sequence of D Hermitian matrices Xμ(μ=1,2,...,D) and construct a corresponding classical space as a set of all coherent states. When the classical space forms a smooth manifold, we also express various geometric objects on the classical space such as the metric, Levi-Civita connection, curvature and Poisson tensor, in terms of the matrix elements. This method provides a new class of observables in matrix models, which characterize geometric properties of matrix configurations. © 2015 American Physical Society.


Hayasaka H.,Kyoto University | Miyashita T.,Kyoto University | Tamura K.,University of Tsukuba | Akagi K.,Kyoto University
Advanced Functional Materials | Year: 2010

Novel multifunctional conjugated polymers, (poly(p-phenylene)s and poly(bithienylene-phenylene)s with (R)· and (S)-configurations], which have fluorescence, chirality, and photoresponsive properties, have been designed and synthesized. The polymers are composed of π-conjugated main chains, where poly(p-phenylene) and poly(bithienylene-phenylene) are fluorescence moieties, and the side chains of the photochrome dithienylethene moiety are linked with chiral alkyl groups. The polymer films exhibit right- or left-handed circularly polarized fluorescence (CPF) and also show reversible quenching and emitting behaviors as a result of photochemical isomerization of the dithienylethene moiety upon irradiation with ultraviolet and visible light. This is the first report realizing the reversible switching of CPF using chirality and photoresponsive properties. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.


Onda T.,National Cancer Center Hospital | Yoshikawa H.,University of Tsukuba
Expert Review of Anticancer Therapy | Year: 2011

Neoadjuvant chemotherapy for advanced ovarian cancer was initially administered as an alternative treatment for patients not suitable for primary debulking surgery (PDS) because of unresectable tumor or poor performance status. Accumulation of favorable outcomes of this treatment compared with standard treatment starting with PDS made this strategy a candidate for prospective, randomized Phase III studies without limiting the subjects to patients who were unsuitable for PDS. Among the four Phase III studies to date, the earliest study from the European Organization for Research and Treatment of Cancer (EORTC) has revealed noninferior survival with less-serious morbidity in the neoadjuvant chemotherapy arm. These data suggest that neoadjuvant chemotherapy followed by surgical cytoreduction is an acceptable management strategy for patients with advanced ovarian cancer. In this article, we review the treatment outcomes and discuss some unanswered questions, as well as possible future research in this area. © 2011 Expert Reviews Ltd.


Rajendran A.,Kyoto University | Rajendran A.,University of Tsukuba | Endo M.,Kyoto University | Endo M.,Japan Science and Technology Agency | And 2 more authors.
Chemical Reviews | Year: 2014

Various investigations of the structural and functional changes in several proteins in physiological solutions carried out using state-of-the-art HS-AFM (high speed atomic force microscopy). Chemical reactions of several proteins with their target DNA sequences were described either on a bare mica surface or incorporated within a DNA origami substrate. These studies provided simultaneously detailed structural dynamics of proteins and DNA sequences. The sliding movement of histone core particles along DNA in nucleosome is described briefly. In addition to DNA-protein interactions, a brief outline of protein-protein interactions was also given. Conformational changes in proteins caused by external stimuli, such as light and nucleotides, were demonstrated. Imaging of magnetosomes and the location of magnetosome-associated proteins were depicted. Regarding the range of operation of AFM, it is suitable for analysis of various biomolecules, ranging from a single protein and/or DNA nanostructure to a whole cell and from the spatial resolution of a few nanometers to several micrometers.


Yokokawa M.,Kyoto University | Yokokawa M.,University of Tsukuba | Takeyasu K.,Kyoto University
FEBS Journal | Year: 2011

Studies of ion pumps, such as ATP synthetase and Ca 2+-ATPase, have a long history. The crystal structures of several kinds of ion pump have been resolved, and provide static pictures of mechanisms of ion transport. In this study, using fast-scanning atomic force microscopy, we have visualized conformational changes in the sarcoplasmic reticulum Ca 2+-ATPase (SERCA) in real time at the single-molecule level. The analyses of individual SERCA molecules in the presence of both ATP and free Ca 2+ revealed up-down structural changes corresponding to the Albers-Post scheme. This fluctuation was strongly affected by the ATP and Ca 2+ concentrations, and was prevented by an inhibitor, thapsigargin. Interestingly, at a physiological ATP concentrations, the up-down motion disappeared completely. These results indicate that SERCA does not transit through the shortest structure, and has a catalytic pathway different from the ordinary Albers-Post scheme under physiological conditions. © 2011 The Authors Journal compilation.


Markland T.E.,Columbia University | Morrone J.A.,Columbia University | Berne B.J.,Columbia University | Miyazaki K.,University of Tsukuba | And 2 more authors.
Nature Physics | Year: 2011

Glasses are dynamically arrested states of matter that do not exhibit the long-range periodic structure of crystals1-4. Here we develop new insights from theory and simulation into the impact of quantum fluctuations on glass formation. As intuition may suggest, we observe that large quantum fluctuations serve to inhibit glass formation as tunnelling and zero-point energy allow particles to traverse barriers facilitating movement. However, as the classical limit is approached a regime is observed in which quantum effects slow down relaxation making the quantum system more glassy than the classical system. This dynamical reentrance occurs in the absence of obvious structural changes and has no counterpart in the phenomenology of classical glass-forming systems. © 2011 Macmillan Publishers Limited. All rights reserved.


Yatagai A.,University of Tsukuba | Yatagai A.,Kyoto University | Kamiguchi K.,Japan Meteorological Agency | Arakawa O.,Japan Meteorological Agency | And 3 more authors.
Bulletin of the American Meteorological Society | Year: 2012

The activities of the APHRODITE project, including outreach programs, have had many important benefits. Investigations of future changes in monsoon and/or extreme events and assessments of historical/future changes in hydrological flow rely on accurate long-term daily gridded observation data of precipitation. The APHRODITE project has made such data available and has substantially improved precipitation estimates throughout Asia. © 2012 American Meteorological Society.


Watanabe K.,Kyoto University | Iida H.,University of Tsukuba | Akagi K.,Kyoto University
Advanced Materials | Year: 2012

Cationic π-conjugated polymers form an interchain helically π-stacked assembly with anionic chiral compounds that is stabilized by both electrostatic and π-π interactions to hierarchically self-organize into a spherulite with a circularly polarized blue luminescence. To the best of our knowledge, this is the first example of a chiroptical spherulite that is hierarchically constructed from π-conjugated polymers. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Taguchi T.,Japan National Institute of Materials Science | Taguchi T.,University of Tsukuba | Isozaki K.,Japan National Institute of Materials Science | Isozaki K.,Kyoto University | And 2 more authors.
Advanced Materials | Year: 2012

An unprecedented substrate-selective catalytic enhancement effect of an alkanethiol-self-assembled monolayer (SAM) on Au nanoparticles (AuNPs) is reported. In the supported 2D-array of AuNPs, the alkanethiol-SAM acts as a protein-like soft reaction space in which the substrate molecules are encapsulated through non-covalent intermolecular hydrophobic interactions, and thus catalytic reactions are accelerated at AuNP surfaces. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Hayasaka H.,Kyoto University | Miyashita T.,Kyoto University | Nakayama M.,University of Tsukuba | Kuwada K.,Kyoto University | Akagi K.,Kyoto University
Journal of the American Chemical Society | Year: 2012

Chirality switching is intriguing for the dynamic control of the electronic and optical properties in nanoscale materials. The ability to photochemically switch the chirality in liquid crystals (LCs) is especially attractive given their potential applications in electro-optic displays, optical data storage, and the asymmetric synthesis of organic molecules and polymers. Here, we present a dynamic photoswitching of the helical inversion in chiral nematic LCs (N*-LCs) that contain photoresponsive axially chiral dopants. Novel photoresponsive chiral dithienylethene derivatives bearing two axially chiral binaphthyl moieties are synthesized. The dihedral angle of the binaphthyl rings changes via the photoisomerization between the open and closed forms of the dithienylethene moiety. The N*-LCs induced by the dithienylethene derivatives that are used as chiral dopants exhibit reversible photoswitching behaviors, including a helical inversion in the N*-LC and a phase transition between the N*-LC and the nematic LC. The present compounds are the first chiral dopants that induce a helical inversion in N*-LC via the photoisomerization between open and closed forms of the dithienylethene moiety. © 2012 American Chemical Society.


Yagi Y.,University of Tsukuba | Fukahata Y.,Kyoto University
Geophysical Journal International | Year: 2011

In principle, we can never know the true Green's function, which is a major error source in seismic waveform inversion. So far, many studies have devoted their efforts to obtain a Green's function as precise as possible. In this study, we propose a new strategy to cope with this problem. That is to say, we introduce uncertainty of Green's function into waveform inversion analyses. Due to the propagation law of errors, the uncertainty of Green's function results in a data covariance matrix with significant off-diagonal components, which naturally reduce the weight of observed data in later phases. Because the data covariance matrix depends on the model parameters that express slip distribution, the inverse problem to be solved becomes non-linear. Applying the developed inverse method to the teleseismic P-wave data of the 2006 Java, Indonesia, tsunami earthquake, we obtained a reasonable slip-rate distribution and moment-rate function without the non-negative slip constraint. The solution was independent of the initial values of the model parameters. If we neglect the modelling errors due to Green's function as in the conventional formulation, the total slip distribution is much rougher with significant opposite slip components, whereas the moment-rate function is much smoother. If we use a stronger smoothing constraint, more plausible slip distribution can be obtained, but then the moment-rate function becomes even smoother. By comparing the observed waveforms with the synthetic waveforms, we found that high-frequency components were well reproduced only by the new formulation. The modelling errors are essentially important in waveform inversion analyses, although they have been commonly neglected. © 2011 The Authors Geophysical Journal International © 2011 RAS.


Yagi Y.,University of Tsukuba | Fukahata Y.,Kyoto University
Geophysical Research Letters | Year: 2011

On 11 March 2011, the Tohoku-oki earthquake in eastern Japan and the devastating tsunami that followed it caused severe damage and numerous deaths. To clarify the rupture process of the earthquake, we inverted teleseismic P-wave data applying a novel formulation that takes into account the uncertainty of Green's function, which has been a major error source in waveform inversion. The estimated seismic moment is 5.7 × 1022 Nm (Mw = 9.1), associated with a fault rupture 440 km long and 180 km wide along the plate interface. The source process is characterized by asymmetric bilateral rupture propagation, but we also found continuous slips up-dip from the hypocenter, which led to a large maximum slip (50 m), long slip duration (90 s), and a large stress drop (20 MPa). The long slip duration, large stress drop, extensional (normal faulting) aftershocks in a previously compressional stress regime, and low-angle normal slips at approximately the depth of the plate interface suggest that the earthquake released roughly all of the accumulated elastic strain on the plate interface owing to exceptional weakening of the fault. The stress accumulated on the plate interface was about 20 MPa near the trench and 0-10 MPa in the down-dip source region. Copyright 2011 by the American Geophysical Union.


Hall D.,University of Tsukuba | Hoshino M.,Kyoto University
Biophysical Reviews | Year: 2010

Compared to biochemical reactions taking place in relatively well-defined aqueous solutions in vitro, the corresponding reactions happening in vivo occur in extremely complex environments containing only 60-70% water by volume, with the remainder consisting of an undefined array of bio-molecules. In a biological setting, such extremely complex and volume-occupied solution environments are termed 'crowded'. Through a range of intermolecular forces and pseudo-forces, this complex background environment may cause biochemical reactions to behave differently to their in vitro counterparts. In this review, we seek to highlight how the complex background environment of the cell can affect the diffusion of substances within it. Engaging the subject from the perspective of a single particle's motion, we place the focus of our review on two areas: (1) experimental procedures for conducting single particle tracking experiments within cells along with methods for extracting information from these experiments; (2) theoretical factors affecting the translational diffusion of single molecules within crowded two-dimensional membrane and three-dimensional solution environments. We conclude by discussing a number of recent publications relating to intracellular diffusion in light of the reviewed material. © 2010 International Union for Pure and Applied Biophysics (IUPAB) and Springer.


Nagatomo S.,University of Tsukuba | Nagai M.,Hosei University | Kitagawa T.,University of Hyogo
Journal of the American Chemical Society | Year: 2011

The single residue vibrational spectra of tryptophan (Trp) and tyrosine (Tyr) residues in human adult hemoglobin (HbA), which play important roles in cooperative oxygen binding, were determined for the deoxy and CO-bound forms by applying UV resonance Raman spectroscopy to various variant Hbs. It was found that Trpβ37, Tyrα42, Tyrα140, and Tyrβ145 at the α 1 - β 2 subunit interface underwent transitions between two contact states (named as T and R) upon ligand binding, while Trpα14, Trpβ15, and Tyrβ35 displayed little changes. The corresponding spectral changes were identified only for the α 2β 2 tetramer, but not the isolated α and β chains in the oligomeric forms, and therefore were exclusively attributed to a quaternary structure change. Ligand binding as well as allosteric effectors and pH altered only the number of the T-contacted Tyr and Trp residues without varying the two contact states themselves. A new method to semiquantitatively evaluate the amount of T-contacted Tyr and Trp residues in a given liganded form is here proposed, and with it a quaternary structure was determined for various symmetrically half-liganded forms obtained with ligand - hybrid, metal - hybrid, and valency - hybrid Hbs. It was found that ligand binding to the α or β subunits yielded different subunit contacts and that the contact changes of the Trp and Tyr residues were not always concerted. The contact changes at the α 1 - β 2 (α 2 - β 1) interface are correlated with the proximal strain exerted on the Fe - His(F8) bond, which is noted to be much larger in the α than β subunits in the α 2β 2 tetramer. © 2011 American Chemical Society.


Fujii N.,Kyoto University | Kaji Y.,University of Tsukuba
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2011

Homochirality is essential for life. l-Amino acids are exclusively used as substrates for the polymerization and formation of peptides and proteins in living systems. However, d-amino acids, which are enantiomers of l-amino acids, were recently detected in various living organisms in the form of free d-amino acids and d-amino acid residues in peptides and proteins. In particular, d-aspartyl (Asp) residues have been detected in various proteins from diverse tissues of elderly individuals. Here, we describe three important aspects of our research: (i) a method for detecting d-β-Asp at specific sites in particular proteins, (ii) a likely spontaneous mechanism by which Asp residues in proteins invert and isomerize to the d-β-form with age under physiological conditions, (iii) a discussion of factors that favor such a reaction. © 2011 Elsevier B.V.


Miura S.,Kobe Steel | Fujisawa A.,Kobe Steel | Ishida M.,University of Tsukuba
International Journal of Hydrogen Energy | Year: 2012

This work is to develop a new hydrogen purification and storage system for daily start and stop (DSS) operations. The new system enables us to minimize emissions of carbon dioxide by using compact and highly efficient fuel cells. The new system first removes carbon monoxide, which is poisonous to metal hydride, from reformed gas by using a special carbon monoxide adsorbent. After removing carbon monoxide, the reformed gas is introduced to a metal hydride bed to purify and store hydrogen. Some 100 NL/h Laboratory scale apparatus was operated in daily start and stop operations for 100 cycles for a total of 150 h with quite good efficiency. The new process has achieved an 83% hydrogen recovery ratio in one-month DSS operations. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Ujiie K.,University of Tsukuba | Tsutsumi A.,Kyoto University
Geophysical Research Letters | Year: 2010

We conducted high-velocity friction experiments on clay-rich fault gouge taken from the megasplay fault zone in the Nankai subduction zone under dry and wet conditions. In the dry tests, dehydration of clay minerals occurred by frictional heating, and slip weakening is related to thermal pressurization associated with water vaporization, resulting in a random distribution of clay-clast aggregates in the gouge matrix. In the wet tests, slip weakening is caused by pore-fluid pressurization via shear-enhanced compaction and frictional heating, and there is a very weak dependence of the steady-state shear stress on the normal stress. The resulting microstructure reflects the grain size segregation in a granular-fluid shear flow at high shear rates. These results suggest that earthquake rupture propagates easily through clay-rich fault gouge by high-velocity weakening, potentially leaving the microstructures resulting from the frictional heating or the flow sorting at high slip rates. Copyright 2010 by the American Geophysical Union.


Yabuno H.,University of Tsukuba | Seo Y.,Keio University | Kuroda M.,University of Hyogo
Applied Physics Letters | Year: 2013

The eigenstate shift in two nearly identical and weakly coupled cantilevers provides a means to realize much higher-sensitivity mass detection compared with the eigenfrequency shift approach. We propose using self-excited oscillations for eigenstate detection without using frequency response or resonance curve normally used in conventional methods. Mass sensing thus becomes possible even in high-viscosity environments, where the peak of the frequency response curve is ambiguous or does not exist. The feedback control method is theoretically clarified to produce self-excited oscillation and the validity of the proposed method is investigated experimentally using macroscale coupled cantilevers. © 2013 AIP Publishing LLC.


Pincella F.,Japan National Institute of Materials Science | Pincella F.,University of Tsukuba | Isozaki K.,Japan National Institute of Materials Science | Isozaki K.,Kyoto University | And 2 more authors.
Light: Science and Applications | Year: 2014

We demonstrate a bottom-up approach to fabricating a visible light-driven titania photocatalyst device bearing an embedded two-dimensional (2D) array of gold nanoparticles (AuNPs) as a near-field light-generating layer. The device is a layered structure prepared by depositing a 2D array of AuNPs on a transparent conductive substrate (10 nm indium tin oxide (ITO) layer on quartz), coating the 2D array of AuNPs with a monolayer of trimethoxyoctylsilane (TMOS), and depositing titania nanocrystals on the anchoring molecule (TMOS) layer. The visible light activity of the device was tested using photocatalytic degradation of methylene blue (MB) by illuminating the device with visible light (700 nm light) and ultraviolet (UV) light (250-380 nm). The localized surface plasmon resonance peak of the 36 nm AuNP 2D array is around 700 nm with a full-width at half-maximum of 350 nm. In comparison with other control samples, the device showed the highest photocatalytic activity with visible irradiation, which was 1.7 times higher than that of titania with UV irradiation. The origin of the visible light activity was confirmed by both quadratic incident light power dependency and action spectrum to be plasmon-induced (near-field enhancement by AuNPs) two-photon absorption. © 2014 CIOMP. All rights reserved.


Suzuki K.G.N.,Kyoto University | Suzuki K.G.N.,Japan Science and Technology Agency | Kasai R.S.,Kyoto University | Hirosawa K.M.,Kyoto University | And 5 more authors.
Nature Chemical Biology | Year: 2012

Advanced single-molecule fluorescent imaging was applied to study the dynamic organization of raft-associated glycosylphosphatidylinositol-anchored proteins (GPI-APs) in the plasma membrane and their stimulation-induced changes. In resting cells, virtually all of the GPI-APs are mobile and continually form transient (∼200 ms) homodimers (termed homodimer rafts) through ectodomain protein interactions, stabilized by the presence of the GPI-anchoring chain and cholesterol. Heterodimers do not form, suggesting a fundamental role for the specific ectodomain protein interaction. Under higher physiological expression conditions, homodimers coalesce to form hetero- and homo-GPI-AP oligomer rafts through raft-based lipid interactions. When CD59 was ligated, it formed stable oligomer rafts containing up to four CD59 molecules, which triggered intracellular Ca 2+ responses that were dependent on GPI anchorage and cholesterol, suggesting a key part played by transient homodimer rafts. Transient homodimer rafts are most likely one of the basic units for the organization and function of raft domains containing GPI-APs. © 2012 Nature America, Inc. All rights reserved.

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