Azuma T.,Setsunan University |
Morita T.,University of Kentucky |
Takeuchi S.,Shanghai JiaoTong University
Physical Review Letters | Year: 2014
It is expected that the Gregory-Laflamme (GL) instability in the black string in gravity is related to the Rayleigh-Plateau instability in fluid mechanics. Especially, the orders of the phase transitions associated with these instabilities depend on the number of the transverse space dimensions, and they are of first and second order below and above the critical dimension. Through the gauge-gravity correspondence, the GL instability is conjectured to be thermodynamically related to the Hagedorn instability in large-N gauge theories, and it leads to a prediction that the order of the confinement-deconfinement transition associated with the Hagedorn instability may depend on the transverse dimension. We test this conjecture in the D-dimensional bosonic D0-brane model using numerical simulation and the 1/D expansion, and confirm the expected D dependence. © 2014 American Physical Society.
News Article | December 3, 2015
In a study published in Current Biology, Andrew Singson, a professor in the Department of Genetics in the School of Arts and Sciences, and colleagues from the National Institutes of Health and the College of William and Mary in Virginia, identified a protein, SPE-45, on the sperm of C. elegan worms that help bind sperm to eggs during fertilization. It is the same as the Izumo protein considered essential for humans and other mammals to reproduce that was discovered a decade ago by Japanese scientists who named it after a marriage shrine in Japan. "Humans and worms are connected by a common ancestor that lived more than 700 million years ago and this discovery will give us insight into their shared genetics and fertility pathways," said Singson, a principal investigator at the Waksman Institute of Microbiology. The research suggests that a common ancestor to both worms and humans had a SPE-45/Izumo-like gene that was required for sperm to function properly at fertilization, said Singson, who has been researching the biological process of fertility for the past two decades. "Twenty years ago when we started this research, we predicted that we would find the genes that are required for fertility from worms to humans," said Singson. "Now we know that this kind of molecule functions the same way beyond the mammalian branch of the tree of life." In the United States, one in eight couples has fertility problems. While about 70 percent of the cases can be attributed equally to the man or woman, 30 percent of the time no explanation can be found. In the new Rutgers study, scientists found that worms produced normal-looking sperm but could not create offspring because the sperm cell lacked the SPE-45 protein on its surface similar to sperm in humans and other mammals that lacked the Izumo protein. Blocking the protein prevents sperm from binding and fusing with the egg. "The protein works like molecular Velcro and helps the sperm and egg bind and fuse," said Singson. "This type of finding can play an indispensable role in understanding the biological process." The discovery was corroborated by a team of scientists working at Emory University in Georgia and Setsunan University in Japan. Taking a different approach and using computer analysis to look at DNA sequences, this international team came up with the same conclusion which was also published in Current Biology. Comparing the worm and mammalian DNA sequences they created a hybrid SPE-45/Izumo molecule that can cure infertility in worms. "This makes the results much more solid because two research groups have basically validated the results of the other," Signson said. Since studying human infertility directly is very challenging due to many ethical and experimental limitations, making a genetic connection between worms and humans will help in future treatments because scientists can do experiments in worms to learn more about the function of Izumo-like molecules that they cannot do in mammals, Singson said. "Finding new fertility genes in the worm can help us further understand the molecular basis of human fertility," he said. "The end result of this knowledge could be more informed and effective treatments for human infertility and reliable contraceptives for both sexes."
Shimada Y.,Setsunan University |
Matsuoka Y.,Kyoto University
Science of the Total Environment | Year: 2011
Most household fuels used in Asian countries are solid fuels such as coal and biomass (firewood, crop residue and animal dung). The particulate matter (PM), CO, NOx and SOx produced through the combustion of these fuels inside the residence for cooking and heating has an adverse impact on people's health. PM 2.5 in particular, consisting of particles with an aerodynamic diameter of 2.5μm or less, penetrates deep into the lungs and causes respiratory system and circulatory system diseases and so on. As a result, the World Health Organization (WHO) established guideline values for this type of particulate matter in 2005. In this study, the authors focused on PM 2.5 and estimated indoor exposure concentrations for PM 2.5 in 15 Asian countries. For each environment used for cooking, eating, heating and illumination in which people are present temporarily (microenvironment), exposure concentrations were estimated for individual cohorts categorized according to sex, age and occupation status. To establish the residence time in each microenvironment for each of the cohorts, data from time use surveys conducted in individual countries were used. China had the highest estimate for average exposure concentration in microenvironment used for cooking at 427.5μg/m 3, followed by Nepal, Laos and India at 285.2μg/m 3, 266.3μg/m 3 and 205.7μg/m 3, respectively. The study found that, in each country, the PM2.5 exposure concentration was highest for children and unemployed women between the ages of 35 and 64. The study also found that the exposure concentration for individual cohorts in each country was greatly affected by people's use of time indoors. Because differences in individual daily life activities were reflected in the use of time and linked to an assessment of exposure to indoor air-polluting substances, the study enabled detailed assessment of the impact of exposure. © 2011 Elsevier B.V.
Hashimoto T.,Osaka University |
Amemiya T.,Setsunan University
IEEE Transactions on Automatic Control | Year: 2011
In this paper, the controllability and observability of linear time-invariant uncertain systems are investigated. The systems under consideration contain time-invariant uncertain parameters that may take arbitrarily large values. In such a situation, the locations of uncertain parameters in system matrices play an important role. We examine the permissible locations of uncertain parameters in system matrices for a linear uncertain system to be controllable and observable independently of the bounds of the uncertain parameters. The objective of this paper is to show that a linear uncertain system is controllable and observable, irrespective of the bounds of uncertain parameters, if and only if the system has a particular configuration called a complete generalized antisymmetric stepwise configuration (CGASC). Furthermore, the dual configuration of a CGASC is introduced and studied here. © 2010 IEEE.
Takebayashi H.,Kobe University |
Moriyama M.,Setsunan University
Solar Energy | Year: 2012
The relationships between the properties of urban canopy components and the radiant environment in an urban street canyon are examined considering the introduction of appropriate urban heat island mitigation technologies. Radiant heat transfers between walls and roads are calculated according to Gebhart's radiant absorption coefficients and using the Monte Carlo method. Roads are classified as either north-south or east-west; intersections are also considered. The key property of an urban street canyon is expressed by its aspect ratio W/. H. A simple street canyon model and two actual urban street canyon areas are used as the objects of examination. Distributions of surface temperatures and solar radiation gains on street canyon roofs, roads, and walls are analyzed. The top priority for the implementation of urban heat island mitigation measures concerns the buildings with large roof areas. The other high-priority areas for implementing mitigation measures focus on smaller roofs and roads for which the street canyon aspect ratio W/. H is greater than 1.5; the lowest-priority area is the walls. © 2012 Elsevier Ltd.
Moriwaki T.,Setsunan University
Key Engineering Materials | Year: 2010
A new ultrasonic vibration cutting device for ultraprecision elliptical vibration cutting has been developed. The elliptical vibration cutting device developed utilizes combination of bending and longitudinal modes of vibration of the stepped vibrator to generate circular or elliptical vibration locus at the cutting tool edge. The design principle as well as the structure and the performance of the elliptical vibration cutting device is introduced here. The experimental results of diamond cutting of Co-Cr-Mo Alloy proved that good surface quality with roughness of 20 nmPV can be obtained stably with the elliptical vibration cutting device developed. © (2010) Trans Tech Publications.
Nabe T.,Setsunan University
Journal of Pharmacological Sciences | Year: 2014
Interleukin (IL)-33, a member of the IL-1 family of cytokines, is produced when epithelial and endothelial cells are exposed to stimuli. Hematopoietic cells such as macrophages also produce IL-33. IL-33 is considered to function as an 'alarmin', activating various immune cells through its receptor ST2, which leads to the production of various molecules. The IL-33-induced production of pro-inflammatory cytokines is a critical event that aggravates atopic diseases such as asthma, atopic dermatitis, and pollenosis and suggests that IL-33-blocking agents could represent new therapeutic drugs. The anti-IL-33 antibody was effective in allergic models, whereas the anti-ST2 antibody has yielded controversial results because soluble ST2 functions as a decoy receptor for IL-33. IL-33-mediated pulmonary inflammation may be glucocorticoidresistant especially when other cytokines act synergistically. Anti-tumor necrosis factor (TNF)-α therapy may also be effective against IL-33-mediated diseases. ERK1/2 inhibitors have also been shown to suppress the production of IL-33. On the other hand, activation of β2-receptors enhanced the expression of IL-33 mRNA in dendritic cells by activating protein kinase A (PKA), suggesting that PKA inhibitors may be candidates for IL-33-blocking agents. The effects of IL-33-blocking agents on atopic diseases need to be pharmacologically assessed in experimental and clinical studies. © The Japanese Pharmacological Society.
Aizawa H.,Setsunan University
Journal of Applied Crystallography | Year: 2010
The structures of micelles of the surfactant polysorbate 80 (Tween 80) in 0-50% aqueous dimethyl sulfoxide (DMSO) solutions (pH 7.2, ionic strength 2.44 mM) were investigated by means of small-angle X-ray scattering. At DMSO concentrations of 0-20%, core-shell cylinder micelles formed, and at 30-50% DMSO, core-shell discus micelles formed, that is, changing the hydrophobicity of the DMSO solvent mixture changed the micelles from core-shell cylinder micelles to core-shell discus micelles. © 2010 International Union of Crystallography Printed in Singapore - all rights reserved.
Miyao T.,Setsunan University
Reviews in Mathematical Physics | Year: 2011
The self-dual cone - the central object of this review - is introduced. Several operator inequalities associated with the self-dual cone are defined and mathematical properties of those are investigated. In general there are infinitely many choices of self-dual cones in a Hilbert space. Each of these lead to a distinct family of operator inequalities in the Hilbert space which enables us to analyze quantum physical models with respect to several aspects. We refer to these applications as self-dual cone analysis. The focus of this review lies on the self-dual cone analysis of models in condensed matter physics. In particular, by taking a physically proper self-dual cone, the interaction term of the Hamiltonian of the system becomes attractive from a viewpoint of our new operator inequalities. This attractive term enables us to analyze the system and various aspects of physical interest in detail. For instance, if the attractive term is ergodic, it is shown that the ground state is unique. By the uniqueness and the conservation laws, the physically symmetric state is realized as the ground state. This could be regarded as a physical order. As applications, the BCS model and the one-dimensional Fröhlich model are studied. We explain, from a viewpoint of the self-dual cone analysis, the appearance of macroscopic phase angles in the superconductors, Josephson effect and the Peierls instability. © 2011 World Scientific Publishing Company.
Kimura T.,Setsunan University
Journal of Health Science | Year: 2010
The expression of metallothionein (MT), a heavy-metal-binding protein, is induced by heavy metals such as zinc, copper, cadmium, and mercury. This induction of MT maintains zinc homeostasis and defends against toxic heavy metals by sequestering these metals and lowering their concentrations at critical intracellular sites. However, MT cannot bind chromium(VI), a heavy metal that has been known for over 100 years to be a human carcinogen. Chromium(VI) enters cells via the sulfate anion transporter system and is reduced to intermediate oxidation states, such as chromium(V) and chromium(IV), in the process of forming stable chromium(III) forms. Chromium(VI) is known to inhibit MT gene transcription, and recently my colleagues and I reported that chromium(VI) inhibits zinc-induced MT gene transcription by modifying the transactivation potential of metal response element-binding transcription factor-1 (MTF-1), a zinc-finger transcription factor. Inhibition of MT gene transcription may therefore be involved in the carcinogenicity of chromium(VI). In this review, I briefly summarize the molecular mechanisms of heavy metal-induced MT gene transcription and discuss the current status of research on chromium(VI) toxicity and chromium(VI)-mediated inhibition of MT gene transcription. © 2010 The Pharmaceutical Society of Japan.