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Fukuoka, Japan

Kyushu University , abbreviated to Kyudai , is a Japanese public university located in Fukuoka, Kyushu. It is one of Japan's National Seven Universities . The history of Kyushu University can be traced by medical schools of the feudal domains built in 1867, and is the largest public university in Kyushu.There are 1,292 foreign students enrolled in the University. It was chosen for the Global 30 university program, and has been selected to the top 13 global university project. Wikipedia.

Yamamoto T.,Kyushu University
Clinics in Orthopedic Surgery | Year: 2012

A subchondral insufficiency fracture (SIF) of the femoral head is a recently proposed concept, which needs to be differentiated from osteonecrosis. Clinically, SIF has generally been observed in the osteoporotic elderly women or renal transplant recipients. Radiographical changes are not obvious in its early phase, however, some cases undergo subchondral collapse (crescent sign). On the T1-weighted magnetic resonance images, a low intensity band is one of the characteristic imaging appearances, which corresponds histologically to the fracture line and associated fracture repair tissue. Therefore, the shape of the low intensity band generally tends to be irregular, disconnected, and convex to the articular surface. The prognosis of SIF is not clearly established. Some cases show resolution of the symptoms by the conservative treatments, while other cases show rapid progression of the collapse such as rapidly progressive arthrosis of the hip. © 2012 by The Korean Orthopaedic Association. Source

Mitsudomi T.,Kinki University | Suda K.,Kyushu University | Yatabe Y.,Aichi Cancer Center Hospital
Nature Reviews Clinical Oncology | Year: 2013

The discovery in 2004 of activating mutations in the EGFR gene opened the era of personalized medicine in thoracic oncology. Treatment with drugs that target EGFR typically results in dramatic tumour response compared with conventional chemotherapy in patients with non-small-cell lung cancer. Subsequently, newer driver oncogenes such as ALK, ROS1 and RET have been discovered. Nevertheless, surgery has become safer and less invasive in the past 10-15 years. In the era of personalized medicine, thoracic surgeons have to think about their evolving roles. In this article, we discuss four topics relevant to this issue. Firstly, the value of surgical specimens as opposed to biopsy specimens for further understanding tumour biology is discussed. Secondly, extended indication of surgery in the era of targeted therapy is considered. Thirdly, in clinical trials that examine neoadjuvant therapy in patients selected by appropriate biomarkers, the important role of surgeons is highlighted. Finally, the possibility of personalizing the surgical procedure itself according to lung cancer subtypes defined by biomarkers is reviewed. ©2013 Macmillan Publishers Limited. All rights reserved. Source

Shimojo M.,Kyushu University
Journal of the Faculty of Agriculture, Kyushu University | Year: 2015

Exponential function is used not only for the basic growth analysis of the individual plant or animal in animal agriculture but also for the space expansion analysis in cosmology. This study was designed to investigate the problems in the size expansion analysis of the toy space model based on the hypothetical relationships between scale factor, exponential function and Bondi K-factor. Problems (A) - (E) were shown. (A) The toy space model using Bondi K-factor was related to the Minkowski space (flat space-time), which was different from the standard model of cosmic expansion based on the FLRW metric. (B) The toy space model was related to the relativistic Doppler redshift, but not to the cosmological redshift that was used in the standard model. (C) Even if Bondi K-factor was hypothetically and forcedly related to the cosmic scale factor through exponential function, the relativistic Doppler redshift merely gave a very poor approximation to the cosmological redshift. (D) The rapid but decelerated expansion at the early stage of the toy space model was not consistent with the accelerated expansion of the inflationary theory. (E) The toy space model did not give the information on the energy distribution of the universe (baryonic matter, dark matter and dark energy), though this toy model gave a mathematical curve composed of early rapid expansion in decelerated expansion, inflection point and accelerated expansion. In conclusion, this study showed that the toy space model using Bondi K-factor had various problems when compared with the standard model of cosmic expansion. Source

Ishizuka T.,Shimizu Corporation | Fujiwara K.,Kyushu University
Journal of the Acoustical Society of America | Year: 2012

The performance of balconies with ceiling-mounted reflectors on a high-rise building façade is examined using numerical analyses and scale-model experiments. The reflectors are designed to reflect direct and diffracted waves incident on the ceiling outside the balcony. The sound pressure reduction, provided by the reflectors, on a window surface adjacent to the balcony is evaluated at intermediate floors levels. In terms of A-weighted sound pressure levels, a balcony equipped with reflectors reduces road traffic noise by 7-10 dB(A), compared to an ordinary balcony, at incident angles of noise close to the angle for which the reflectors are designed. The efficiency is roughly the same as, or greater than, that of a balcony with an absorbent ceiling. However, it is also shown that when the vertical incident angle of the noise is smaller than the design angle of the reflectors, or the horizontal incident angle is large, efficiency is reduced. © 2012 Acoustical Society of America. Source

Machida M.N.,Kyushu University | Inutsuka S.-I.,Kyoto University | Matsumoto T.,Hosei University
Monthly Notices of the Royal Astronomical Society | Year: 2014

The formation of a circumstellar disc in collapsing cloud cores is investigated with threedimensional magnetohydrodynamic simulations.We prepare four types of initial cloud having different density profiles and calculate their evolution with or without a sink. To investigate the effect of magnetic dissipation on disc formation, Ohmic dissipation is considered in some models. Calculations show that disc formation is very sensitive to both the initial cloud configuration and the sink treatment. The disc size considerably differs in clouds with different density profiles even when the initial clouds have almost the same mass-to-flux ratio. Only a very small disc (̃10 au in size) appears in clouds with a uniform density profile, whereas a large disc (̃100 au in size) forms in clouds with a Bonnor-Ebert density profile. In addition, a large sink accretion radius numerically impedes disc formation during the main accretion phase and tends to foster the misleading notion that disc formation is completely suppressed by magnetic braking. The protostellar outflow is also greatly affected by the sink properties. A sink accretion radius of ≤1 au and sink threshold density of ≥1013 cm-3 are necessary for investigating disc formation during the main accretion phase ©2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Van Der Ha J.C.,Kyushu University
Acta Astronautica | Year: 2011

We study the directional stability of rigid and deformable spinning satellites in terms of two attitude angles. The linearized attitude motion of a free system about an assumed uniform-spin reference solution leads to a generic MGK system when the satellite is rigid or deformable. In terms of Lyapunov's stability theory, we investigate the stability with respect to a subset of the variables. For a rigid body, the MGK system is 6-dimensional, i.e., 3 rotational and 3 translational variables. When flexible parts are present the system can have any arbitrary dimension. The 2×2 McIntyreMyiagi stability matrix gives sufficient conditions for the attitude stability. A further development of this method has led to the Equivalent Rigid Body method. We propose an alternative practical method to establish sufficiency conditions for directional stability by using the FrobeniusSchur reduction formula. As practical applications we discuss a spinning satellite augmented with a springmass system and a rigid body appended with two cables and tip masses. In practice, the attitude stability must also be investigated when the spinning satellite is subject to a constant axial thrust. The generic format becomes MGKN as the thrust is a follower force. For a perfectly aligned thrust along the spin axis, Lyapunov's indirect method remains valid also when deformable parts are present. We illustrate this case with an apogee motor burn in the presence of slag. When the thrust is not on the spin axis or not pointing parallel to the spin axis, the uniform-spin reference motion does not exist and none of the previous methods is applicable. In this case, the linearization may be performed about the initial state. Even when the linearized system has bounded solutions, the non-linear system can be unstable in general. We illustrate this situation by an instability that actually happened in-flight during a station-keeping maneuver of ESA's GEOS-I satellite in 1979. © 2010 Elsevier Ltd. Source

Sakaguchi H.,Kyushu University | Malomed B.A.,Tel Aviv University
Journal of the Optical Society of America B: Optical Physics | Year: 2012

We consider two-dimensional (2D) localized modes in the second-harmonic-generating (X(2)) system with the harmonic-oscillator (HO) trapping potential. In addition to its realization in optics, the system describes the mean-field dynamics of mixed atomic-molecular Bose-Einstein condensates (BECs). The existence and stability of various modes is determined by their total power, N, topological charge, m/2 [m is the intrinsic vorticity of the second-harmonic (SH) field], and X(2) mismatch, q. The analysis is carried out in a numerical form and, in parallel, by means of the variational approximation (VA), which produces results that agree well with numerical findings. Below a certain power threshold, N ≤ Nm (q), all trappedmodes are of the single-color type, represented by the SH component only, while the fundamental frequency (FF) one is absent. In contrast with the usual situation, where such modes are always unstable, we demonstrate that they are stable, for m = 0, 1, 2 (the mode with m = 1 may be formally considered as a semivortex with topological charge m/2 = 1 /2), at N ≤ Ncm(q), and unstable above this threshold. On the other hand, Ncm(q) = 0 at q = qmax (in our notation, qmax = 1); hence the single-color modes are unstable in the latter case. At N = Nc(m), the modes with m = 0 and m = 2 undergo a pitchfork bifurcation, which gives rise to two-color states, which remain completely stable for m = 0. The two-color vortices with m = 2 (topological charge 1) have an upper stability border, N = Nc2(q). Above the border, they exhibit periodic splittings and recombinations, while keeping their vorticity. The semivortex does not bifurcate; at N = Nc(m=1), it exhibits quasi-chaotic oscillations and a rotating "groove" resembling a screw-edge dislocation induced by the semi-integer vorticity. © 2012 Optical Society of America. Source

Sakaguchi H.,Kyushu University | Malomed B.A.,Tel Aviv University
Optics Letters | Year: 2012

We demonstrate that modulation of the local strength of the cubic self-focusing (SF) nonlinearity in the twodimensional geometry, in the form of a circle with contrast Δg of the SF coefficient relative to the ambient medium with a weaker nonlinearity, stabilizes a family of fundamental solitons against the critical collapse. The result is obtained in an analytical form, using the variational approximation and Vakhitov-Kolokolov stability criterion, and corroborated by numerical computations. For the small contrast, the stability interval of the soliton's norm scales as ΔN ∼ Δg (the replacement of the circle by an annulus leads to a reduction of the stability region by perturbations breaking the axial symmetry). To further illustrate this mechanism, we demonstrate, in an exact form, the stabilization of one-dimensional solitons against the critical collapse under the action of a locally enhanced quintic SF nonlinearity. © 2012 Optical Society of America. Source

Zang Z.-G.,Kyushu University | Zhang Y.-J.,Harbin University
Journal of Modern Optics | Year: 2012

We propose a new optical bistable device (OBD), which is constructed by connecting two symmetrical fiber Bragg gratings with a ytterbium-doped fiber to form a nonlinear Fabry-Perot cavity. The principle of this new OBD is described using the transfer-matrix method, and the two groups of transmitted and reflected optical bistability loops under different parameters are investigated symmetrically. Compared with single fiber Bragg grating switching, whose switching power is greater than 2 kW, this new device has evident merits in reducing the switching power to less than 45mW. © 2011 Copyright Taylor and Francis Group, LLC. Source

Tanimoto J.,Kyushu University
Physica A: Statistical Mechanics and its Applications | Year: 2010

A series of numerical experiments on 2×2 games using a co-evolutionary model, including both networks and strategies, was performed. A relationship between assortativity by degree of the evolved network and emerging cooperation was investigated. In the Prisoner's Dilemma (PD) game class, the evolutionary trajectory for a weak dilemma game favors a network with positive assortative coefficient and easily attains a cooperative situation. A game implemented with a stronger dilemma, however, makes the network very heterogeneous, with a negative assortative coefficient required to solve the dilemma situation. This implies that the dilemma strength in the PD significantly affects the direction adopted by the assortative coefficient during evolutionary processes in the co-evolutionary model. © 2010 Elsevier B.V. All rights reserved. Source

Ogata Y.,Kyushu University
Communications in Mathematical Physics | Year: 2010

We show the full large deviation principle for KMS-states and C*-finitely correlated states on a quantum spin chain. We cover general local observables. Our main tool is Ruelle's transfer operator method. © Springer-Verlag 2010. Source

Saito T.,Chiba Institute of Technology | Itakura M.,Kyushu University
Journal of Alloys and Compounds | Year: 2013

The microstructures of high-coercivity Co-Zr-B melt-spun ribbons were examined in order to determine the hard magnetic phase in the Co-Zr-B alloys. Throughout X-ray diffraction (XRD) and magnetic studies, as well as microstructural studies by scanning electron microscope (SEM), transmission electron microscope (TEM), and scanning transmission electron microscope (STEM), no Co5Zr phase was found in the Co-Zr-B melt-spun ribbons. Only the CoxZr (x ≈ 5) phase was detected, indicating that the hard magnetic phase in the Co-Zr-B alloys was the CoxZr phase. The TEM and STEM studies revealed that the Co-Zr-B alloys had very fine CoxZr grains of around 200 nm in diameter and that the hard magnetic CoxZr phase was surrounded by the soft magnetic Co grain boundary phase. © 2013 Elsevier B.V. All rights reserved. Source

Sindoro M.,University of Illinois at Urbana - Champaign | Yanai N.,Kyushu University | Granick S.,University of Illinois at Urbana - Champaign
Accounts of Chemical Research | Year: 2014

Colloidal metal-organic frameworks (CMOFs), nanoporous colloidal-sized crystals that are uniform in both size and polyhedral shape, are crystals composed of metal ions and organic bridging ligands, which can be used as building blocks for self-assembly in organic and aqueous liquids. They stand in contrast to conventional metal-organic frameworks (MOFs), which scientists normally study in the form of bulk crystalline powders. However, powder MOFs generally have random crystal size and shape and therefore do not possess either a definite mutual arrangement with adjacent particles or uniformity. CMOFs do have this quality, which can be important in vital uptake and release kinetics.In this Account, we present the diverse methods of synthesis, pore chemistry control, surface modification, and assembly techniques of CMOFs. In addition, we survey recent achievements and future applications in this emerging field. There is potential for a paradigm shift, away from using just bulk crystalline powders, towards using particles whose size and shape are regulated. The concept of colloidal MOFs takes into account that nanoporous MOFs, conventionally prepared in the form of bulk crystalline powders with random crystal size, shape, and orientation, may also form colloidal-sized objects with uniform size and morphology. Furthermore, the traditional MOF functions that depend on porosity present additional control over those MOF functions that depend on pore interactions. They also can enable controlled spatial arrangements between neighboring particles.To begin, we discuss progress regarding synthesis of MOF nano- and microcrystals whose crystal size and shape are well regulated. Next, we review the methods to modify the surfaces with dye molecules and polymers. Dyes are useful when seeking to observe nonluminescent CMOFs in situ by optical microscopy, while polymers are useful to tune their interparticle interactions. Third, we discuss criteria to assess the stability of CMOFs for various applications. In another section of this Account, we give examples of supracrystal assembly in liquid, on substrates, at interfaces, and under external electric fields. We end this Account with discussion of possible future developments, both conceptual and technological. © 2013 American Chemical Society. Source

Takeda T.,Kyushu University
Fukuoka igaku zasshi = Hukuoka acta medica | Year: 2013

Maternal exposure to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) causes a number of toxic effects on development such as growth retardation and sexual immaturity in the offspring. However, the toxic mechanism remains unknown. Our previous studies have revealed that single oral administration of TCDD (1 jg/kg) to pregnant rats at gestational day (GD) 15 attenuates the fetal expression of testicular steroidogenic proteins such as steroidogenic acute-regulatory protein (StAR) and cytochrome P450 (CYP) 17 by targeting the fetal production of pituitary gonadotropins. In addition, we provided evidence that TCDD-produced damage on the fetal pituitary-gonad axis leads to imprint defects in sexual behaviors at adulthood. In this study, we investigated whether TCDD also affects fetal steroidogenesis in the adrenal gland. When pregnant Wistar rats were orally treated with TCDD, the fetal expression of CYP21, CYP11B1 and CYP11B2 mRNAs was either induced or tended to be induced in the male adrenal gland during GD17 and GD19, while the expression of mRNAs coding for StAR, CYP11A1 and 313-hydroxysteroid dehydrogenase was insensitive to TCDD treatment. The above alterations did not seem to be caused through a change in the upstream regulator, because TCDD exhibited little ability to attenuate the expression of adrenocorticotropin, a pituitary hormone stimulating adrenal steroidogenesis, in the male and female fetuses. In contrast to the males, TCDD effect on the adrenal gland was not observed in the female fetuses. These results suggest that maternal exposure to TCDD disrupts fetal steroidogenesis in adrenal as well as gonadal glands in a male specific manner, and the mechanism underlying the effect on adrenal gland is independent of the alteration of pituitary regulator. Source

Sado T.,Kyushu University
Philosophical transactions of the Royal Society of London. Series B, Biological sciences | Year: 2013

In female mammals, one of the two X chromosomes becomes genetically silenced to compensate for dosage imbalance of X-linked genes between XX females and XY males. X chromosome inactivation (X-inactivation) is a classical model for epigenetic gene regulation in mammals and has been studied for half a century. In the last two decades, efforts have been focused on the X inactive-specific transcript (Xist) locus, discovered to be the master regulator of X-inactivation. The Xist gene produces a non-coding RNA that functions as the primary switch for X-inactivation, coating the X chromosome from which it is transcribed in cis. Significant progress has been made towards understanding how Xist is regulated at the onset of X-inactivation, but our understanding of the molecular basis of silencing mediated by Xist RNA has progressed more slowly. A picture has, however, begun to emerge, and new tools and resources hold out the promise of further advances to come. Here, we provide an overview of the current state of our knowledge, what is known about Xist RNA and how it may trigger chromosome silencing. Source

Yoo J.,Kyushu University
Nanoscale | Year: 2011

Recent developments of non-covalent functionalization of carbon nanotubes (CNTs) require a systematic understanding of the interaction between molecule and CNTs (CNT-molecular interaction); however, it has been difficult to evaluate the "net" interaction between the CNTs and molecules. We now use silica gel particles coated with the pristine single-walled carbon nanotubes (SWNTs) in a monolayer fashion as the stationary phase of a HPLC column. The newly developed column (SWNT-column) worked as a powerful tool for ranking the interactions between the SWNTs and molecules with a high precision. We describe the binding affinity analysis of polyaromatic hydrocarbons onto the surfaces of SWNTs. The obtained ranking is determined in the order of benzene < naphthalene < biphenyl < fluorene < phenanthrene < anthracene ∼ pyrene < triphenylene < p-terphenyl < tetraphene < tetracene. Source

Tanabe T.,Kyushu University
Physica Scripta | Year: 2014

Although extensive studies on hydrogen (H) retention in tungsten (W) loaded by ion implantation, plasma exposure and gas charging have been done, reported amounts of H retained in W, and their dependences on the incident flux, fluence and temperature are very inconsistent. The present work aims at the clarification of the H retention mechanisms with critical review of reported data and presentation of recent results. H diffusion coefficient for dissolved H in W is large enough to allow for a deep penetration of H into W bulk. Energetic H loading results in H saturation in the subsurface layers. The thickness of the saturated layers could grow under prolonged loading and the H in the layers remain long or hard to remove. Both the growth of the thickness of the saturated layers and the deep penetration of H into the bulk could result in significantly large H retention in W and dissipate the advantage of W as plasma facing wall. © 2014 The Royal Swedish Academy of Sciences. Source

Sudo N.,Kyushu University
Chemical Immunology and Allergy | Year: 2012

There has been an increasing and intense interest in the role that gut bacteria play in maintaining the health of the host. Gut microbiota have an estimated mass of 1-2 kg, number 100 trillion and together possess 100 times the number of genes in the human genome. In addition to their well-established role in the postnatal maturation of the mammalian immune system, they are also responsible for an enormous array of metabolic activities that include effects on the digestion of food and the production of a host of biologically active substances. Moreover, it is also rapidly becoming apparent that the gut microbiome plays a major role in the development and regulation of neuroendocrine systems such as the hypothalamic-pituitary-adrenal axis, a central integrative system crucial for the successful physiological adaptation of the organism to stress. In fact, our previous study on gnotobiotic mice demonstrated that exposure to gut microbes is a postnatal environmental determinant that regulates the development of the hypothalamic-pituitary-adrenal axis stress response and also the set point for this axis. Copyright © 2012 S. Karger AG, Basel. Source

One of the most basic techniques in biomedical research is cDNA cloning for expression studies in mammalian cells. Vaccinia topoisomerase I-mediated cloning (TOPO cloning by Invitrogen) allows fast and efficient recombination of PCR-amplified DNAs. Among TOPO vectors, a pcDNA3.1 directional cloning vector is particularly convenient, since it can be used for expression analysis immediately after cloning. However, I found that the cloning efficiency was reduced when RT-PCR products were used as inserts (about one-quarter). Since TOPO vectors accept any PCR products, contaminating fragments in the insert DNA create negative clones. Therefore, I designed a new mammalian expression vector enabling positive blue white selection in Vaccinia topoisomerase I-mediated cloning. The method utilized a short nontoxic LacZa peptide as a linker for GFP fusion. When cDNAs were properly inserted into the vector, minimal expression of the fusion proteins in E. coli (harboring lacZΔM15) resulted in formation of blue colonies on X-gal plates. This method improved both cloning efficiency (75%) and directional cloning (99%) by distinguishing some of the negative clones having non-cording sequences, since these inserts often disturbed translation of lacZa. Recombinant plasmids were directly applied to expression studies using GFP as a reporter. Utilization of the P2A peptide allowed for separate expression of GFP. In addition, the preparation of Vaccinia topoisomerase I-linked vectors was streamlined, which consisted of successive enzymatic reactions with a single precipitation step, completing in 3 hr. The arrangement of unique restriction sites enabled further modification of vector components for specific applications. This system provides an alternative method for cDNA cloning and expression in mammalian cells. © 2015 Hiroshi Udo. Source

Mougi A.,Kyushu University
PLoS ONE | Year: 2010

Background: Our understanding of coevolution in a predator-prey system is based mostly on pair-wise interactions. Methodology and Principal Findings: Here I analyze a one-predator-two-prey system in which the predator's attack ability and the defense abilities of the prey all evolve. The coevolutionary consequences can differ dramatically depending on the initial trait value and the timing of the alternative prey's invasion into the original system. If the invading prey species has relatively low defense ability when it invades, its defense is likely to evolve to a lower level, stabilizing the population dynamics. In contrast, if when it invades its defense ability is close to that of the resident prey, its defense can evolve to a higher level and that of the resident prey may suddenly cease to evolve, destabilizing the population dynamics. Destabilization due to invasion is likely when the invading prey is adaptively superior (evolution of its defense is less constrained and fast), and it can also occur in a broad condition even when the invading prey is adaptively inferior. In addition, invasion into a resident system far from equilibrium characterized by population oscillations is likely to cause further destabilization. Conclusions and Significance: An invading prey species is thus likely to destabilize a resident community. © 2010 Akihiko Mougi. Source

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin-producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to its histomorphological and immunohistochemical characteristics. Endoscopic retrograde cholangiopancreatography plays a crucial role in the evaluation of these features of IPMN. Endoscopic ultrasonography (EUS) has proven to be more sensitive than computed tomography or magnetic resonance imaging for early detection of malignancy. The present review addresses the current roles of endoscopy and related techniques in the management of IPMN. The particular focus is on diagnosing IPMN and malignancy within IPMN, detecting pancreatic cancer concomitant with IPMN, differentiating the epithelial subtypes of IPMN, determining the optimal strategy for the management of branch duct IPMN, and discussing innovative endoscopic technology related to IPMN. The disadvantages of endoscopic examinations of IPMN and different attitudes toward EUS-guided fine-needle aspiration for IPMN between Japan (negative) and other countries (active) are also discussed. © 2015 The Author. Digestive Endoscopy published by Wiley Publishing Asia Pty Ltd on behalf of Japan Gastroenterological Endoscopy Society. Source

Fujimura N.,Kyushu University
Proceedings ACM SIGUCCS User Services Conference | Year: 2013

At Kyushu University, we have been providing students with access to computers for education of information processing since 1979. The computers have varied from general purpose computer to personal computers (PCs). The number of PCs increased dramatically for about thirty years. The number of lectures with PCs has also been increasing rapidly for information literacy, CALL (Computer-Assisted Language Learning), and so on. We have been always trying to arrange the PC rooms as many as possible to provide the good and comfortable ICT (Information and Communication Technology) environment for students. However, we never have the budget to equip enough PC rooms. On the other hand, the price of PCs has been going down over time. As a result, our students of 95% in first grade have their own PCs around when they enter the university. In response to these changes, we have decided to abandon terminal rooms. We now expect all students to bring their own PCs and use them in their classes. After many meetings and committee discussions, we are going to start the new ICT environment for education in April 2013. It has taken almost two years to start up the Bring Your Own PCs (BYOPC) project. Following were the important steps to begin the BYOPC project in Kyushu University: -Gain agreement in the university-How to decide the PC model, Windows or Mac, in each department-Software (Windows, Office: EES contract with Microsoft) -Anti-Virus software (Symantec Endpoint Protection) -Wireless LAN (IEEE 802.11n, 80% covered of lecture rooms and so on) -Firewall (P2P file exchange software) -Seminar for all newcomers (Software installation, network configuration and so on) We will report the detail and the result in the above points. It was a difficult and hard work. For example, I visited sixteen faculties and/or departments to explain the new policy and how to proceed on the project in order to get the cooperation and help. Ultimately, we had a great success on our project. Copyright 2013 ACM. Source

Morohashi K.,Kyushu University
Sexual development : genetics, molecular biology, evolution, endocrinology, embryology, and pathology of sex determination and differentiation | Year: 2013

It has been more than 150 years since the physiological function of androgen was reported for the first time in fowl. This finding has served as a basis for many studies focusing on steroid hormones from various aspects. These studies have significantly enhanced our knowledge about the structures of steroid hormones, their synthetic pathways, enzymes involved in the synthetic pathways, steroid hormone-specific receptors, actions of steroid hormones through receptor binding, and the differentiation of steroidogenic cells. However, there are still many attractive and important issues in these areas, some of which are currently being addressed. In this review, we trace the history and findings of the previous studies on steroid hormones, summarize our present understanding in this area, and discuss issues that remain to be elucidated. Copyright © 2012 S. Karger AG, Basel. Source

Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) is expected to be less invasive than laparoscopic distal pancreatectomy with splenectomy. However, there are few reports regarding the details of the procedure for LSPDP, and its safety remains unclear. This study aimed to evaluate the feasibility and safety of LSPDP. Six patients underwent LSPDP from March 2009 to February 2013 in our center, and their clinical data and outcomes were reviewed retrospectively. A total of six laparoscopic distal pancreatic resections were attempted in four female and two male patients. All of the operations were successful, with an average operative time of 290.7 min (range: 211-377 min) and an average blood loss of 43.5 g (range: 0-142 g). The mean hospital stay was 11.8 days (range: 9-17days). No obvious pancreatic fistulas occurred, although pseudocysts at the stump of the pancreas were recognized in three patients on CT scans performed at 7 days postoperatively. Postoperative pathological examinations revealed two cases of serous cystadenoma in the body and tail of the pancreas, one case of serous oligocystic adenoma, one case of mucinous cystadenoma, one case of neuroendocrine tumor, and one case of solid-pseudopapillary neoplasm. LSPDP is minimally invasive, safe, and feasible for the management of benign pancreatic tail tumors, with the advantages of earlier recovery and less morbidity from complications. Source

Murawaki Y.,Kyushu University
PLoS ONE | Year: 2015

Phylogenetic models, originally developed to demonstrate evolutionary biology, have been applied to a wide range of cultural data including natural language lexicons, manuscripts, folktales, material cultures, and religions. A fundamental question regarding the application of phylogenetic inference is whether trees are an appropriate approximation of cultural evolutionary history. Their validity in cultural applications has been scrutinized, particularly with respect to the lexicons of dialects in contact. Phylogenetic models organize evolutionary data into a series of branching events through time. However, branching events are typically not included in dialectological studies to interpret the distributions of lexical terms. Instead, dialectologists have offered spatial interpretations to represent lexical data. For example, new lexical items that emerge in a politico-cultural center are likely to spread to peripheries, but not vice versa. To explore the question of the tree model's validity, we present a simple simulation model in which dialects form a spatial network and share lexical items through contact rather than through common ancestors.We input several network topologies to the model to generate synthetic data. We then analyze the synthesized data using conventional phylogenetic techniques. We found that a group of dialects can be considered tree-like even if it has not evolved in a temporally tree-like manner but has a temporally invariant, spatially tree-like structure. In addition, the simulation experiments appear to reproduce unnatural results observed in reconstructed trees for real data. These results motivate further investigation into the spatial structure of the evolutionary history of dialect lexicons as well as other cultural characteristics. © 2015 Yugo Murawaki. Source

Abe K.-I.,Kyushu University
Flow, Turbulence and Combustion | Year: 2014

An anisotropy-resolving subgrid-scale (SGS) model for large eddy simulation was investigated. Primary attention was given to the predictive performance of the SGS model in the case of complex turbulence with flow impingement and/or flow separation. The SGS model was constructed by combining an isotropic linear eddy-viscosity model with an extra anisotropic term. Since the extra anisotropic term was modeled to prevent undesirable energy transfer between the grid-scale and SGS parts, the model is expected not to seriously affect computational stability. To validate the model performance for complex turbulent flow fields, the SGS model was applied to numerical simulations of a plane impinging jet and 3-D diffuser flow as well as fundamental plane channel flows. The SGS model provided reasonable predictions for these test cases. Furthermore, the predicted SGS stress components were decomposed into linear and anisotropic parts and their roles were investigated in detail. The usefulness of the present anisotropy-resolving SGS model in practical engineering applications was thus described. © 2013 Springer Science+Business Media Dordrecht. Source

Kaneshima S.,Kyushu University
Physics of the Earth and Planetary Interiors | Year: 2016

Recent seismological studies have revealed that rocks with significantly different elastic properties are juxtaposed in the mid-lower mantle and often scatter seismic waves efficiently enough to be detected by seismic array analyses. Seismic networks all over the world with various aperture and geometry have been utilized for detecting scattered waves. A large number of objects that act as scatterers in the mid-lower mantle have been mapped out by analyzing several different types of scattered waves, mostly of short period: S-to-P scattering, P-to-P scattering prior to PP waves, P-to-P scattering prior to P′P′, P-to-P scattering in P coda waves, and P-to-P scattering prior to PKP. The scatterers have a lesser size that is smaller than the wavelengths (∼10 km), and probably extend several tens of kilometers at least. The mid-mantle scatterers are most likely to represent basaltic rocks that subducted into the lower mantle. Revealing the elastic properties relative to the surrounding rocks and the geometry of the individual scatterers, as well as the global distribution of the scatterers, should shed new light on the style of mantle convection. Relevant observations of mid-lower mantle scatterers are reviewed, and the directions of future progress are suggested. © 2016 Elsevier B.V. Source

Species-environment relationships are key information for the development of planning and management strategies for conservation or restoration of ecosystems. Artificial neural networks (ANNs) are one widely applied type of species distribution model (SDM). Fuzzy neural networks (FNNs), that is, fuzzified ANNs, have been introduced to take into account the uncertainties inherent in fish behaviour and errors in input data. Despite their high predictive ability in modelling complex systems, FNNs cannot describe habitat preference curves (HPCs), although these are the basis for habitat quality assessment. The present study therefore aimed to evaluate the applicability of FNNs for modelling habitat preference and spatial distributions of Japanese medaka (Oryzias latipes), one of the most common freshwater fish in Japan. Three independent data sets were collected during a series of field surveys and used for model development and evaluation of FNNs. A weight decay backpropagation algorithm was additionally introduced, and its effects on the FNNs were evaluated on the basis of model performance and habitat preference information retrieved from the field observation data. Modified sensitivity analysis was applied to derive HPCs of the target fish. Application of weight decay backpropagation markedly reduced the variability of the model structures, improved the generalization ability of the FNNs, and resulted in well-converged and consistent HPCs that were similar to those evaluated by fuzzy habitat preference models. These results support the applicability of FNNs to habitat preference modelling, which can provide useful information on the habitat use by the target fish. Further study should focus on the effects of sources of uncertainty, such as zero abundance, on the SDMs and the resulting habitat preference evaluation. © 2011 Elsevier B.V. Source

Ichihashi R.,Kyushu University | Tateno M.,University of Tokyo
Journal of Ecology | Year: 2011

1.Lianas face a dilemma: how can they achieve a balance between the benefits they gain from light capture in their host canopies and the risk of falls resulting from the deleterious effects they have on the growth and survival of their host trees? To address this issue, we investigated leaf distribution patterns, canopy dynamics and the impact of four liana species on the growth of their hosts. 2.In the forest canopy, the majority of the leaves of Actinidia arguta (Actinidiaceae) received >80% irradiance relative to the canopy top. The leaf mass and the length of the canopy framework of this species increased linearly with time after it had reached the forest canopy (estimated from the number of growth rings in the main liana stem at 8m height). In contrast, a much lower percentage irradiance was received by leaves of the three other species, Celastrus orbiculatus (40-80%, Celastraceae), Schisandra repanda (<40%, Schisandraceae) and Schizophragma hydrangeoides (<20%, Hydrangeaceae). In these species, canopy sizes did not change markedly with time. Species that intercepted more light acquired a larger number of host trees. 3.Growth-ring widths of the host trees of A. arguta and C. orbiculatus were smaller than those of liana-free trees; this difference was not significant in the two species that intercepted less light. The length of the basal stem between the rooting point and the point of attachment to the current host tree was greater in species that intercepted more light, suggesting the successful movement of these lianas to new hosts following the death of previous host trees. 4.Synthesis. Lianas have various ecological strategies for resolving their dilemma. They may be aggressive and rapidly spread in host canopies, intercepting much light, but reducing the risk of falls by acquiring many host trees to balance their top-heavy architecture. Alternatively, they may be commensal, whereby small liana canopies in lower positions in their host canopies acquire less light, but do not negatively affect the current hosts. Such variations reflect niche differentiation among species, and could be an important mechanism underlying the diversification and coexistence of liana species. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society. Source

Goto T.,Kyushu University
Clinical calcium | Year: 2014

The concept of osseointegration was developed and the term was coined Dr. Brånemark. Osseointegration is initially defined as the direct structural and functional connection between living bone and surface living bone and the surface of a loadbearing artificial implant, typically made of titanium. Osseointegration required new bone formation around fixture, the healing of implant system is similar to primary bone healing. Bone formation on the titanium surface needs the formation of oxide film, deposition of calcium phosphate, and deposition of the protein. However, osseointegration is not the direct bonding between bone and the titanium surface, there exists an amorphous layer including osteopontin or osteocalcin that osteoblasts use them as a scaffold. In clinical the ratio of bone and implant contacts is called as BIC, and BIC was from 40% to 60% if the osseointegration was obtained. Numerous studies were performed for the surface modification to increase the score of BIC. Recently, surface treatments such as glow discharge, acid-etch, or UV irradiation have been found to be effective for osseointegration. Further modification would be needed to maintain the osseointegration as well as to obtain the osseointegration. Source

Machida M.N.,Kyushu University
Astrophysical Journal Letters | Year: 2014

A protostellar jet and outflow are calculated for ∼270 yr following the protostar formation using a three-dimensional magnetohydrodynamics simulation, in which both the protostar and its parent cloud are spatially resolved. A high-velocity (∼100 km s-1) jet with good collimation is driven near the disk's inner edge, while a low-velocity (≲ 10 km s-1) outflow with a wide opening angle appears in the outer-disk region. The high-velocity jet propagates into the low-velocity outflow, forming a nested velocity structure in which a narrow high-velocity flow is enclosed by a wide low-velocity flow. The low-velocity outflow is in a nearly steady state, while the high-velocity jet appears intermittently. The time-variability of the jet is related to the episodic accretion from the disk onto the protostar, which is caused by gravitational instability and magnetic effects such as magnetic braking and magnetorotational instability. Although the high-velocity jet has a large kinetic energy, the mass and momentum of the jet are much smaller than those of the low-velocity outflow. A large fraction of the infalling gas is ejected by the low-velocity outflow. Thus, the low-velocity outflow actually has a more significant effect than the high-velocity jet in the very early phase of the star formation. © 2014. The American Astronomical Society. All rights reserved. Source

Suehiro J.,Kyushu University
Biomicrofluidics | Year: 2010

Dielectrophoresis (DEP) is an electrokinetic motion of dielectrically polarized materials in nonuniform electric fields. DEP has been successfully applied to manipulation of nanomaterials including carbon nanotubes (CNTs), metallic nanoparticles, and semiconducting nanowires. Under positive DEP force, which attracts nanomaterials toward the higher field region, nanomaterials are trapped in the electrode gap and automatically establish good electrical connections between them and the external measuring circuit. This feature allows us a fast, simple, and low-cost fabrication of nanomaterial-based sensors based on a bottom-up approach. This paper first presents a theoretical background of DEP phenomena and then reviews recent works of the present author, which were aimed to develop nanomaterial-based sensors, such as a CNT gas sensor and a ZnO nanowire photosensor, using DEP fabrication technique. It is also demonstrated that DEP technique enables self-formation of interfaces between various nanomaterials, which can be also applicable as novel sensing transducers. © 2010 American Institute of Physics. Source

Zang Z.-G.,Kyushu University | Yang W.-X.,Kobe University
Journal of Applied Physics | Year: 2011

A new all-optical switching device, which is constructed by connecting an erbium-doped fiber with two symmetrical long-period fiber gratings (EDF-LPFGs), is demonstrated. The performance of EDF-LPFGs switching has been investigated based on cross-phase modulation under different parameters. The theoretical analysis shows that the threshold switching power is inverse proportional to the nonlinear coefficient of the erbium-doped fiber, and is proportional to the effective area of the erbium-doped fiber and absorption coefficient. Moreover, the switching power as low as 36 mW and high extinction ratio of 18 dB are obtained in our experiment. Good agreement between the theoretical and experimental results indicate that EDF-LPFGs switching is a new design in support of switching power reduction. © 2011 American Institute of Physics. Source

Wakano J.Y.,Meiji University | Wakano J.Y.,Japan Science and Technology Agency | Iwasa Y.,Kyushu University
Genetics | Year: 2013

Adaptive dynamics formalism demonstrates that, in a constant environment, a continuous trait may first converge to a singular point followed by spontaneous transition from a unimodal trait distribution into a bimodal one, which is called "evolutionary branching." Most previous analyses of evolutionary branching have been conducted in an infinitely large population. Here, we study the effect of stochasticity caused by the finiteness of the population size on evolutionary branching. By analyzing the dynamics of trait variance, we obtain the condition for evolutionary branching as the one under which trait variance explodes. Genetic drift reduces the trait variance and causes stochastic fluctuation. In a very small population, evolutionary branching does not occur. In larger populations, evolutionary branching may occur, but it occurs in two different manners: in deterministic branching, branching occurs quickly when the population reaches the singular point, while in stochastic branching, the population stays at singularity for a period before branching out. The conditions for these cases and the mean branching-out times are calculated in terms of population size, mutational effects, and selection intensity and are confirmed by direct computer simulations of the individual-based model. © 2013 by the Genetics Society of America. Source

Nakabeppu Y.,Kyushu University
International Journal of Molecular Sciences | Year: 2014

8-Oxoguanine, a major oxidized base lesion formed by reactive oxygen species, causes G to T transversion mutations or leads to cell death in mammals if it accumulates in DNA. 8-Oxoguanine can originate as 8-oxo-dGTP, formed in the nucleotide pool, or by direct oxidation of the DNA guanine base. MTH1, also known as NUDT1, with 8-oxo-dGTP hydrolyzing activity, 8-oxoguanine DNA glycosylase (OGG1) an 8-oxoG DNA glycosylase, and MutY homolog (MUTYH) with adenine DNA glycosylase activity, minimize the accumulation of 8-oxoG in DNA; deficiencies in these enzymes increase spontaneous and induced tumorigenesis susceptibility. However, different tissue types have different tumorigenesis susceptibilities. These can be reversed by combined deficiencies in the defense systems, because cell death induced by accumulation of 8-oxoG in DNA is dependent on MUTYH, which can be suppressed by MTH1 and OGG1. In cancer cells encountering high oxidative stress levels, a high level of 8-oxo-dGTP accumulates in the nucleotide pool, and cells therefore express increased levels of MTH1 in order to eliminate 8-oxo-dGTP. Suppression of MTH1 may be an efficient strategy for killing cancer cells; however, because MTH1 and OGG1 protect normal tissues from oxidative-stress-induced cell death, it is important that MTH1 inhibition does not increase the risk of healthy tissue degeneration. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

Prosultiamine, a vitamin B1 derivative, has long been used for beriberi neuropathy and Wernicke's encephalopathy. Based on the finding that prosultiamine induces apoptosis in human T lymphotropic virus type I (HTLV-I)-infected T cells, Nakamura et al. conducted a clinical trial of prosultiamine in patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). In this open-label, single arm study enrolling 24 HAM/TSP patients recently published in BMC Medicine, oral prosultiamine (300 mg/day for 12 weeks) was found to be effective by neurological, urological and virological evaluations. Notably, it increased detrusor pressure, bladder capacity and maximum flow rate, and improved detrusor overactivity and detrusor-sphincter dyssynergia. A significant decrease in HTLV-I copy numbers in peripheral blood following the treatment provided a rationale for using the drug. The trial has some limitations, such as the small numbers of participants, the open-label design, the lack of a placebo arm, and the short trial period. Nevertheless, the observation that such a safe, cheap drug may have excellent therapeutic effects on HAM/TSP, a chronic devastating illness occurring mainly in developing countries, provides support for future large-scale randomized controlled trials. Please see related research: http://www.biomedcentral.com/1741-7015/11/182. © 2013 Kira; licensee BioMed Central Ltd. Source

Nagata N.,University of Minnesota | Nagata N.,University of Tokyo | Otono H.,Kyushu University | Shirai S.,German Electron Synchrotron
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

It has been widely known that bino-like dark matter in the supersymmetric (SUSY) theories in general suffers from over-production. The situation can be drastically improved if gluinos have a mass slightly heavier than the bino dark matter as they reduce the dark matter abundance through coannihilation. In this work, we consider such a bino-gluino coannihilation scenario in high-scale SUSY models, which can be actually realized when the squark-mass scale is less than 100-1000 TeV. We study the prospects for exploring this bino-gluino coannihilation scenario at the LHC. We show that the searches for long-lived colored particles with displaced vertices or large energy loss offer a strong tool to test this scenario in collider experiments. © 2015 The Authors. Source

Miura Y.,Kyushu University
Protein and Peptide Letters | Year: 2011

Temperature dependence of the α-helix conformation of bee venom melittin in methanol-water mixed solvents has been examined by NMR, in order to elucidate conformation stability and a phase diagram. At high methanol concentration of 100 - ca. 80 wt.%, melittin forms a full α-helix conformation in the temperature range from 25 °C to 60 °C. At intermediate methanol concentration of ca. 80 - ca. 25 wt.%, it undergoes a thermal transformation from a full α-helix to a partial α-helix. In solutions of low methanol concentrations of ca. 25 - 0 wt.%, partial α-helix monomers and their selfaggregated conformers coexist at low temperatures, and the relative number of the monomers increases with increase in temperature. The monomers turn to a random coil state at high temperatures only below ca. 10 wt. % methanol concentrations. The thermal transitions are discussed from the viewpoint of stability of intra-molecular hydrogen bonds and intermolecular hydrophobic interactions. © 2011 Bentham Science Publishers Ltd. Source

Van Nong N.,Technical University of Denmark | Pryds N.,Technical University of Denmark | Linderoth S.,Technical University of Denmark | Ohtaki M.,Kyushu University
Advanced Materials | Year: 2011

An effective way to improve the thermoelectric performance (ZT) of layered structured oxide materials by carefully choosing heavy ion doping and introducing metallic nanoinclusions is proposed. A p-type oxide material with remarkable highly improved ZT is successfully fabricated using this approach. Long-term durability at high temperature testing confirms this material is a very promising p-type material for high temperature power generation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

As a solution to high peak-to-average power ratio (PAPR) problems in vector coding (VC) systems, phase controlbased methods such as selected mapping (SLM) and partial transmit sequence have been investigated. As described in this study, a phase sequence blind estimation method is presented for PAPR reduction based on phase control in multi-input multi-output (MIMO) adaptive modulated VC systems, where turbo code is employed. On the receiver side, the phase sequence component is estimated using a maximum likelihood method that selects the most likely sequence among all candidate sequences by exploiting soft-output information of the decoder. Computer simulation results show that when the number of candidate sequences in SLM is M = 16, instantaneous power of the transmit signal at the complementary cumulative distribution function of 10-5 can be reduced by about 4.0 and 3.5 dB for single-input single-output and MIMO cases as compared with the case without PAPR reduction, although almost identical block error rate performance and the same throughput performance as in the case of perfect phase sequence estimation are achieved in an attenuated six-path Rayleigh fading condition. © The Institution of Engineering and Technology 2012. Source

Cao S.,University of Antwerp | Nishida M.,Kyushu University | Schryvers D.,University of Antwerp
Acta Materialia | Year: 2011

The three-dimensional size, morphology and distribution of Ni 4Ti3 precipitates in a Ni50.8Ti49.2 polycrystalline shape memory alloy with a heterogeneous microstructure have been investigated using a focused ion beam/scanning electron microscopy slice-and-view procedure. The mean volume, central plane diameter, thickness, aspect ratio and sphericity of the precipitates in the grain interior as well as near to the grain boundary were measured and/or calculated. The morphology of the precipitates was quantified by determining the equivalent ellipsoids with the same moments of inertia and classified according to the Zingg scheme. Also, the pair distribution functions describing the three-dimensional distributions were obtained from the coordinates of the precipitate mass centres. Based on this new data it is suggested that the existence of the heterogeneous microstructure could be due to a very small concentration gradient in the grains of the homogenized material and that the resulting multistage martensitic transformation originates in strain effects related to the size of the precipitates and scale differences of the available B2 matrix in between the precipitates. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Source

Fujita T.,Kyushu University
Environmental Economics and Policy Studies | Year: 2014

We present a simple game model of international environmental agreements and examine the effects of learning (resolution of uncertainty) on the stability of agreements. An agreement is said to be stable if no countries have an incentive to defect from it and free-ride. We have shown that whether negotiations are conducted before or after learning does not have a significant effect on the stability of an agreement, and that it is necessary to include “punishment” in the rules, which means that countries in a coalition should respond to countries defecting from the agreement by individually reducing the amount of their abatements to Nash equilibrium levels. Also shown is the fact that side payments are essential to realization of a stable imputation. It is important to include rules requiring technological and financial aid for abatement of anthropogenic pollutants. © 2004, Springer Japan. Source

Xu J.,Nanjing University of Aeronautics and Astronautics | Kawashima S.,Kyushu University
Archive for Rational Mechanics and Analysis | Year: 2015

We give a new decay framework for the general dissipative hyperbolic system and the hyperbolic–parabolic composite system, which allows us to pay less attention to the traditional spectral analysis in comparison with previous efforts. New ingredients lie in the high-frequency and low-frequency decomposition of a pseudo-differential operator and an interpolation inequality related to homogeneous Besov spaces of negative order. Furthermore, we develop the Littlewood–Paley pointwise energy estimates and new time-weighted energy functionals to establish optimal decay estimates on the framework of spatially critical Besov spaces for the degenerately dissipative hyperbolic system of balance laws. Based on the Lp(ℝn) embedding and the improved Gagliardo–Nirenberg inequality, the optimal Lp(ℝn)-L2(ℝn)(1 ≦ p < 2) decay rates and Lp(ℝn)-Lq(ℝn)(1 ≦ p < 2 ≦ q ≦ ∞) decay rates are further shown. Finally, as a direct application, the optimal decay rates for three dimensional damped compressible Euler equations are also obtained. © 2015, Springer-Verlag Berlin Heidelberg. Source

Ebihara Y.,Kyoto University | Tanaka T.,Kyushu University
Journal of Geophysical Research: Space Physics | Year: 2013

We studied fundamental properties of spatial-temporal evolution of energetic electrons trapped in the inner magnetosphere (L ≤ 7.4) during an isolated substorm by using a four-dimensional drift kinetic simulation under the time-dependent electric and magnetic fields provided by a global magnetohydrodynamics (MHD) simulation. When the interplanetary magnetic field turns southward, both the potential and induction electric fields start to increase in the inner magnetosphere, resulting in a gradual injection of low-energy electrons (≤51.9 keV) and deceleration of high-energy electrons (≥114 keV). The deceleration of high-energy electrons results in a decrease in the phase space density of the high-energy electrons during the growth phase. After a while, an abrupt transition of phase state (a substorm onset) occurs in the magnetosphere, which triggers abrupt changes in the magnetosphere and ionosphere. The AL index decreases rapidly, and magnetic field lines become dipole-like. The dipolarization does not proceed smoothly in the inner magnetosphere because of significant force imbalance between the J × B force and the grad P force. As a consequence, the electric field oscillates with a period of 2-3 min, resulting in multiple injections of the low-energy electrons. The low- and high-energy electrons are accelerated under the strong influence of the drift betatron and gyro betatron, so that the acceleration process is essentially nonlinear. Our simulation results suggest that the force-induced processes play an essential role in the substorm-associated redistribution of energetic particles in the inner magnetosphere. Key Points Two types of substorm-electric fields are identified in the inner magnetosphere.Electric field oscillation is generated by force imbalance near substorm onsetRedistribution of energetic electrons comes from force imbalance and ionosphere © 2013. American Geophysical Union. All Rights Reserved. Source

Sasaki Y.,Kyushu University
Geophysics | Year: 2011

The effect of seafloor topographic variations on controlled-source electromagnetic (CSEM) responses is investigated using a finite-difference modeling approach for both petroleum and gas-hydrate exploration scenarios. In a deepwater reservoir model, distortions in the inline electric field responses are mainly due to galvanic effects, particularly at long transmitter-receiver (Tx-Rx) offsets, and are characterized by persistent short-wavelength anomalies at all Tx-Rx offsets in the amplitude profiles. In a shallow-water reservoir model, the contribution of inductive effects to bathymetric distortions is large at short Tx-Rx offsets compared to the deepwater case, whereas at long offsets, the distortion pattern is mainly determined by the source-receiver geometry relative to the sea surface because of the airwave effect rather than by the resistivity variations associated with the seafloor topography. A simple correction technique, which is an extension of the topographic correction procedure for magnetotelluric data, is effective in removing the bathymetric distortions for the deep marine case, but cannot be used for the shallow-water case because of the airwave effect. For a gas-hydrate exploration model, it is shown that the bathymetric response can be large enough to mask the target response, because higher frequencies and shorter offsets need to be used to detect the shallow targets. However, the modeling study suggests that the shallow target response can be separated from the bathymetric distortions using the correction method. © 2011 Society of Exploration Geophysicists. Source

Hirose N.,Kyushu University
Journal of Oceanography | Year: 2011

Significant impacts of the subgridscale parameterizations have been emphasized in modeling the ocean circulations, but various different parameter values are applied to similar numerical studies often without any justification. This study objectively estimates a set of empirical parameters along with their uncertainty for circulation modeling of the East Asian Marginal Seas. The solutions for 14 major parameters are obtained by using model Green's functions with constraints of climatological temperature and salinity data. The largest cost function reduction occurs in the eastern Japan Sea associated with the sharp gradient of the Polar Front. The calibrated parameters are also validated with realistic transport and path of the Kuroshio in the final experiment. The inverse estimation shows that freshwater discharges from small rivers can be attributed to the coastal precipitation over a strip of land 74-81 km wide. The thickness diffusion coefficient may be similar to the isopycnal and horizontal diffusion coefficients in their magnitude. The accelerated initial condition also contributes to the cost function reduction resulting in weaker trends of deep temperature. Most importantly, estimated scaling factors suggest a significant reduction of the reanalyzed wind stress data for more realistic ocean circulations. Possible reasons for the momentum missing are also discussed. © 2011 The Oceanographic Society of Japan and Springer. Source

Tsukamoto Y.,University of Tokyo | Tsukamoto Y.,Japan National Astronomical Observatory | Machida M.N.,Kyushu University
Monthly Notices of the Royal Astronomical Society | Year: 2013

We investigate the formation and evolution of circumstellar discs in turbulent cloud cores until several 104 yr after protostar formation using smoothed particle hydrodynamics (SPH) calculations. The formation and evolution process of circumstellar disc in turbulent cloud cores differs substantially from that in rigidly rotating cloud cores. In turbulent cloud cores, a filamentary structure appears before the protostar formation and the protostar forms in the filament. If the turbulence is initially sufficiently strong, the remaining filament twists around the protostar and directly becomes a rotation-supported disc. Upon formation, the disc orientation is generally misaligned with the angular momentum of its host cloud core and it dynamically varies during the main accretion phase, even though the turbulence is weak. This is because the angular momentum of the entire cloud core is mainly determined by the largescale velocity field whose wavelength is comparable to the cloud scale, whereas the angular momentum of the disc is determined by the local velocity field where the protostar forms and these two velocity fields do not correlate with each other. In the case of disc evolution in a binary or multiple stars, the discs are misaligned with each other at least during the main accretion phase, because there is no correlation between the velocity fields around the position where each protostar forms. In addition, each disc is also misaligned with the binary orbital plane. Such misalignment can explain the recent observations of misaligned discs and misaligned protostellar outflows. © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Skarstad K.,University of Oslo | Katayama T.,Kyushu University
Cold Spring Harbor Perspectives in Biology | Year: 2013

The replication origin and the initiator protein DnaA are the main targets for regulation of chromosome replication in bacteria. The origin bears multiple DnaA binding sites, while DnaA contains ATP/ADP-binding and DNA-binding domains. When enough ATP-DnaA has accumulated in the cell, an active initiation complex can be formed at the origin resulting in strand opening and recruitment of the replicative helicase. In Escherichia coli, oriC activity is directly regulated by DNA methylation and specific oriC-binding proteins. DnaA activity is regulated by proteins that stimulate ATP-DnaA hydrolysis, yielding inactive ADP-DnaA in a replication-coupled negative-feedback manner, and by DnaA-binding DNA elements that control the subcellular localization of DnaA or stimulate the ADP-to-ATP exchange of the DnaA-bound nucleotide. Regulation of dnaA gene expression is also important for initiation. The principle of replication-coupled negative regulation of DnaA found in E. coli is conserved in eukaryotes as well as in bacteria. Regulations by oriC-binding proteins and dnaA gene expression are also conserved in bacteria. © 2013 Cold Spring Harbor Laboratory Press; all rights reserved. Source

Global distributions and associated climate effects of atmospheric aerosols were simulated using a global aerosol climate model, SPRINTARS, from 1850 to the present day and projected forward to 2100. Aerosol emission inventories used by the Coupled Model Intercomparison Project Phase 5 (CMIP5) were applied to this study. Scenarios based on the Representative Concentration Pathways (RCPs) were used for the future projection. Aerosol loading in the atmosphere has already peaked and is now reducing in Europe and North America. However, in Asia where rapid economic growth is ongoing, aerosol loading is estimated to reach a maximum in the first half of this century. Atmospheric aerosols originating from the burning of biomass have maintained high loadings throughout the 21st century in Africa, according to the RCPs. Evolution of the adjusted forcing by direct and indirect aerosol effects over time generally correspond to the aerosol loading. The probable future pathways of global mean forcing differ based on the aerosol direct effect for different RCPs. Because aerosol forcing will be close to the preindustrial level by the end of the 21st century for all RCPs despite the continuous increases in greenhouse gases, global warming will be accelerated with reduced aerosol negative forcing. © 2012 Author(s). CC Attribution 3.0 License. Source

Yoshikawa Y.,Kyushu University
Journal of Oceanography | Year: 2012

Numerical experiments were performed to investigate the effects of eddies generated in deep water formation processes on an abyssal circulation in a closed bowl-shaped basin. Two sets of experiments were performed. One set was eddy-restricted experiments in which only a volume-driven (upwelling-driven) circulation was simulated and the other set was eddy-permitted experiments in which both a volume-driven circulation and an eddy-driven circulation were simulated. In the two layer experiment where the lower layer water is formed, a mean along-slope current is formed in the lower layer for both the eddy-restricted and eddy-permitted experiments. The direction of the current was not unique in the eddy-restricted experiment, but it was cyclonic in the eddy-permitted experiment. In the three layer experiments where water of the intermediate layer is formed, the mean along-slope current in the lowest layer is negligibly small in the eddy-restricted experiment, while it is large and cyclonic in the eddy-permitted experiment. The driving forcings of the eddy-driven circulation are quantified in terms of eddy fluxes of relative vorticity (Reynolds stress) and layer thickness (bolus velocity). These terms increase as the volume of the newly formed water increases, but they do not change greatly with the slope height. The magnitude of these terms changes with the slope width, but the sum of these terms does not vary greatly. As a result, the intensity of the eddy-driven circulation depends primarily on the volume of newly formed water. These dependences of eddy fluxes were interpreted using downgradient diffusion of potential vorticity. © 2012 The Oceanographic Society of Japan and Springer Japan. Source

Kamei R.,University of Western Ontario | Pratt R.G.,University of Western Ontario | Tsuji T.,Kyushu University
Geophysical Journal International | Year: 2013

We successfully apply the acoustic Laplace-Fourierwaveformtomography method to delineate P-wave velocity structures of themega-splay fault system in the central part of the seismogenic Nankai subduction zone offshore Japan, using densely sampled wide-angle ocean bottom seismograph (OBS) data originally acquired in 2004. Our success is due to new and carefully designed data preconditioning and inversion strategies to mitigate (i) the well-known nonlinearity of waveform inversion, (ii) the challenges arising from crustal-scale survey designs (e.g. undersampling of the OBSs), and (iii) modelling errors due to the use of the acoustic assumption. We identify a sixfold set of key components that together lead to the success of the highresolution waveform tomography image: (i) Availability of low-frequency components (starting at 2.25 Hz) reducing the non-linearity, and access to large offset data (up to 55 km) increasing the depth of illumination and the recovery of low wavenumber components. (ii) A highly accurate traveltime tomography result (with an rms error of approximately 60ms) that further mitigates the non-linearity. (iii) A hierarchical inversion approach in which phase spectra are inverted first to reduce artefacts from the acoustic assumption, and amplitude information is only incorporated in the final stages. (iv) A Laplace-Fourier domain approach that facilitates a multiscale approach to mitigate non-linearity by restricting the inversion to the low frequency components and early arrivals first, and sequentially including higher frequencies and later arrivals. (v) A pre-conditioning strategy for eliminating undesirable high wavenumber components from the the gradient. (vi) A strategy for source estimation that reduce the influence of the instrumental design. In theOBS case study used for illustration purposes, Laplace-Fourierwaveformtomography retrieves velocity anomalies as small as 700m (horizontally) and 350m (vertically) above the top of the Philippine Sea Plate. The resulting velocity structures include low-velocity zones and thrust structures which have not been previously identified clearly. The velocity models are validated by scrutiny of synthetic and observed waveforms, by evaluating the coherency of source estimates, and by comparison with 3-D pre-stack migrated (PreSDM) images. Chequerboard tests and point-scatter tests demonstrate both the reliability and the limitations of the acoustic implementation. © The Authors 2013. Source

Ikehata K.,Kyushu University | Hirata T.,Kyoto University
Economic Geology | Year: 2012

The copper isotope ratios of primary and secondary native copper grains in well-characterized plagioclase lherzolites from the Horoman peridotite complex, Hokkaido, northern Japan, were measured by femtosecondpulsed laser ablation-multiple collector-inductively coupled plasma-mass spectrometry (fs-LA-MC-ICP-MS). The whole-rock copper isotope value of the fresh fertile plagioclase lherzolite was also determined. The primary native copper and whole-rock samples yield homogeneous d65Cu (where d65Cu = [{(65Cu/63Cu)sample/ (65Cu/63Cu) NIST-SRM976} - 1] × 1,000) values between -0.03 and 0.14‰, implying that there is no significant copper isotope fractionation during high-temperature magmatic processes. These and previously published results suggest that the copper isotope range of terrestrial igneous copper is from -0.27 to 0.27‰. In contrast, secondary native copper grains affected by serpentinization have obviously lower d65Cu values (-0.67 to -0.41‰) than primary native copper and whole-rock samples, though the compositional differences between primary native copper and secondary native copper are significantly small, suggesting that selective preferential oxidation or leaching of the heavier copper isotope occurs during low-temperature serpentinization processes. Because secondary low-temperature processes probably disturb the original copper isotope values of primary copper-rich minerals, in situ determination of copper isotope values for intact mineral grains by microanalytical techniques such as LA-MC-ICP-MS has become increasingly important to understand primary isotope signatures of rock and ore samples. © 2012 by Economic Geology, Inc. Source

Kuwahara Y.,Kyushu University
American Mineralogist | Year: 2012

This paper reports in situ observations of the dissolution behavior of the barite (001) surface in pure water at 30-55 °C using hot-stage atomic force microscopy (AFM). The dissolution at 30 and 40 °C occurred in three stages; however, at 55 °C, the dissolution behavior observed at the former temperatures started immediately after injecting water into the AFM fluid cell. The first stage of the dissolution was characterized by the retreat of the initial steps and continued for about 60 min at 30 °C and about 10 min at 40 °C. The second stage of the dissolution was characterized by the splitting of the initial one-layer step into two half-layer steps [fast ("f") and slow ("s") retreat steps] with different retreat rates and by the formation of etch pits. The large difference in the retreat rate of the "f" and "s" steps led to the formation of a new one-layer step, which showed slightly faster retreat rates than the "s" half-layer step at all temperatures. The splitting of the [010] one-layer step into two half-layer steps was observed only at 55 °C. During the third stage, the development of angular deep etch pits from an initial form with a curved outline differed at each temperature. The deep etch pits grew rapidly at higher temperature, but showed at least two different retreat rates for the (001) plane at each temperature, indicating the development of the pits along different dislocations (screw and edge dislocations). The activation energies (62-74 kJ/mol) for the step and face retreats in this study were significantly higher than those reported in earlier studies. Recalculations performed using only data obtained under similar conditions in previous studies led to activation energies of 66-79 kJ/mol. These results and the earlier report showing that the form of the deep etch pits changed from angular to bow-shaped at about 60 °C may indicate that the activation energy of barite dissolution in water is higher at lower temperatures as compared with higher temperatures, thus changing the rate-limiting step. Whether the vertical and lateral retreat rates of the barite (001) plane differ in dependence of temperature remains unclear; however, the activation energies of the retreat of the (001) face in deep etch pits tended to be slightly higher than that of the lateral retreat rates of steps or other faces in deep etch pits. Source

Machida M.N.,Kyushu University | Hosokawa T.,University of Tokyo | Hosokawa T.,Jet Propulsion Laboratory
Monthly Notices of the Royal Astronomical Society | Year: 2013

The evolution of protostellar outflow is investigated with resistive magneto-hydrodynamic nested-grid simulations that cover a wide range of spatial scales (∼1 au-1 pc). We follow cloud evolution from the pre-stellar core stage until the infalling envelope dissipates long after the protostar formation. We also calculate protostellar evolution to derive protostellar luminosity with time-dependent mass accretion through a circumstellar disc. The protostellar outflow is driven by the first core prior to protostar formation and is directly driven by the circumstellar disc after protostar formation. The opening angle of the outflow is large in the Class 0 stage. A large fraction of the cloud mass is ejected in this stage, which reduces the star formation efficiency to ∼50 per cent. After the outflow breaks out from the natal cloud, the outflow collimation is gradually improved in the Class I stage. The head of the outflow travels more than ∼10. 5 au in ∼10. 5 yr. The outflow momentum, energy and mass derived in our calculations agree well with observations. In addition, our simulations show the same correlations among outflow momentum flux, protostellar luminosity and envelope mass as those in observations. These correlations differ between Class 0 and I stages, which are explained by different evolutionary stages of the outflow; in the Class 0 stage, the outflow is powered by the accreting mass and acquires its momentum from the infalling envelope; in the Class I stage, the outflow enters the momentum-driven snow-plough phase. Our results suggest that protostellar outflow should determine the final stellar mass and significantly affect the early evolution of low-mass protostars. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Machida M.N.,Kyushu University | Doi K.,Konan University
Monthly Notices of the Royal Astronomical Society | Year: 2013

The formation of Population III stars is investigated using resistive magnetohydrodynamic simulations. Starting from a magnetized primordial prestellar cloud, we calculate the cloud evolution several hundreds of years after first protostar formation, resolving the protostellar radius. When the natal minihalo field strength is weaker than B {less-than and not approximate } 10-13(n/1 cm-3)-2/3 G (n is the hydrogen number density), magnetic effects can be ignored. In this case, fragmentation occurs frequently and a stellar cluster forms, in which stellar mergers and mass exchange between protostars contribute to the mass growth of these protostars. During the early gas accretion phase, the most massive protostar remains near the cloud centre, whereas some of the less massive protostars are ejected. The magnetic field significantly affects Population III star formation when B {greater-than and not approximate } 10-12(n/1 cm-3)-2/3 G. In this case, because the angular momentum around the protostar is effectively transferred by both magnetic braking and protostellar jets, the gas falls directly on to the protostar without forming a disc, and only a single massive star forms. In addition, a massive binary stellar system appears when 10-13(n/1 cm-3)-2/3 {less-than and not approximate } B {less-than and not approximate } 10-12(n/1 cm-3)-2/3 G. Therefore, the magnetic field determines the end result of the formation process (cluster, binary or single star) for Population III stars. Moreover, no persistent circumstellar disc appears around the protostar regardless of the magnetic field strength, which may influence the further evolution of Population III stars. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

To elucidate the conduit processes controlling the amplitude of air pressure waves (Apw) from vulcanian eruptions at the Sakurajima volcano, Japan, we examine ash particles emitted by eruptions preceded by swarms of low-frequency B-type earthquakes (BL-swarms). We measure the water content of glassy ash, an indicator of shallow magma storage pressure, and vesicle textures, such as vesicle number density (VND). These data allow us to reconstruct the shallow conduit by comparing vesicularity with inferred pressure, and therefore depth, of magma storage. The results show that VND increases with depth, implying formation of a dense, outgassed magma cap underlain by more-vesicular, less-outgassed, magma. The VND and water content in the glassy ash positively correlate with the duration of BL-swarms, suggesting that such seismic signals reflect upward migration of deep gas- and vesicle-rich magma. Finally, it is determined that Apw positively correlates with VND, suggesting that the amplitude of the air pressure waves is controlled by the amount of accumulated gas- and bubble-rich magma below the dense magma cap. © 2013 Springer-Verlag Berlin Heidelberg. Source

Kaneshima S.,Kyushu University | Helffrich G.,University of Bristol
Geophysical Journal International | Year: 2013

The Earth'score is composed primarily of iron with several per cent by weight of lighter elements, which are thought to be progressively enriched in the outer liquid core as the core cools and the inner core crystallizes. Detailed profiles of P-wave speed (Vp) of the outermost core might be affected by this process. In this study, we constrain the radial Vp structure in the outermost 600 km of the core by analysing SmKS multiples with m up to 6, which are observed at large-scale broad-band seismometer arrays. Array processing of SmKS waves combined with investigation of their CMB piercing points clearly demonstrate that the array averaged SmKS differential traveltime anomalies primarily reflect the Vp structure in the outermost core. A p inversion is applied to the SmKS (m = 2, 3, 4 and 5) differential times measured by the array processing. The inversion reveals that the Vp is 0.45 per cent slower at the CMB than Preliminary Reference EarthModel (PREM) and the lower Vp anomaly gradually diminishes to zero at 300 km below the CMB. The deviation of the Vp gradient from PREM of the outermost 300 km of the core is nearly an order of magnitude larger than that of the deeper part of the core. The evaluation of Birch's parameter 1 - g-1dφ/dr (φ = V2 p ) for the obtained Vp profile as well as the change in the Vp gradient with depth show that adiabatic self-compression of a homogeneous material cannot explain the observations. Waveforms corresponding to the arrivals of S6KS waves are consistent with the Vp profile of the topmost 50 km of the outer core, and agree with the results from the p inversion. This excludes the presence of a high Vp-low density layer thicker than 10 km immediately beneath the CMB. © The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society. Source

Wada M.,Kyushu University
Plant Science | Year: 2013

Chloroplast movement is important for plant survival under high light and for efficient photosynthesis under low light. This review introduces recent knowledge on chloroplast movement and shows how to analyze the responses and the moving mechanisms, potentially inspiring research in this field. Avoidance from the strong light is mediated by blue light receptor phototropin 2 (phot2) plausibly localized on the chloroplast envelop and accumulation at the week light-irradiated area is mediated by phot1 and phot2 localized on the plasma membrane. Chloroplasts move by chloroplast actin (cp-actin) filaments that must be polymerized by Chloroplast Unusual Positioning1 (CHUP1) at the front side of moving chloroplast. To understand the signal transduction pathways and the mechanism of chloroplast movement, that is, from light capture to motive force-generating mechanism, various methods should be employed based on the various aspects. Observation of chloroplast distribution pattern under different light condition by fixed cell sectioning is somewhat an old-fashioned technique but the most basic and important way. However, most importantly, precise chloroplast behavior during and just after the induction of chloroplast movement by partial cell irradiation using an irradiator with either low light or strong light microbeam should be recorded by time lapse photographs under infrared light and analyzed. Recently various factors involved in chloroplast movement, such as cp-actin filaments and CHUP1, could be traced in Arabidopsis transgenic lines with fluorescent protein tags under a confocal laser scanning microscope (CLSM) and/or a total internal reflection fluorescence microscope (TIRFM). These methods are listed and their advantages and disadvantages are evaluated. © 2013 Elsevier Ireland Ltd. Source

Pyatenko A.,Japan National Institute of Advanced Industrial Science and Technology | Wang H.,Japan National Institute of Advanced Industrial Science and Technology | Koshizaki N.,Japan National Institute of Advanced Industrial Science and Technology | Tsuji T.,Kyushu University
Laser and Photonics Reviews | Year: 2013

The laser is a very powerful and very useful instrument in modern nanoscience and nanotechnology. The knowledge of the interaction mechanism of the laser beam with nanoparticles is needed to control the laser processing of different nano-objects. It was shown that the particle heating-melting-evaporation model can be successfully applied for many phenomena arising when colloidal nanoparticle interact with pulsed laser beams. The general approach of this model is discussed in detail. The two main components of the model, light absorption by particles, and the thermodynamics of phase transitions in particulate material are considered. Special attention is devoted to the correct estimation of the possible heat losses. The way in which the phase diagrams, where the different phase conditions of particle material are presented in laser fluence-particle diameter coordinates, were produced is demonstrated. It is shown how this model can be applied for understanding the mechanism of such complicated processes as particle-size reduction and submicrometer spherical particle growth, as well as other processes that occur when colloidal particles are irradiated by a pulsed laser. The laser is a very powerful and very useful instrument in modern nanoscience and nanotechnology. The knowledge of the interaction mechanism of the laser beam with nanoparticles is needed to control the laser processing of different nano-objects. It was shown that the particle heating-melting-evaporation model can be successfully applied for many phenomena arising when colloidal nanoparticle interact with pulsed laser beams. The general approach of this model is discussed in detail. The two main components of the model, light absorption by particles, and the thermodynamics of phase transitions in particulate material are considered. Special attention is devoted to the correct estimation of the possible heat losses. The way in which the phase diagrams, where the different phase conditions of particle material are presented in laser fluence-particle diameter coordinates, were produced is demonstrated. It is shown how this model can be applied for understanding the mechanism of such complicated processes as particle-size reduction and submicrometer spherical particle growth, as well as other processes that occur when colloidal particles are irradiated by a pulsed laser. © 2013 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yamada T.,Kyoto University | Otsubo K.,Kyoto University | Otsubo K.,Chiyoda Corporation | Makiura R.,Osaka Prefecture University | And 3 more authors.
Chemical Society Reviews | Year: 2013

Coordination polymers (CPs) have large degrees of freedom in framework compositions and in the structures and environment of the inner pores. This review focuses on the recent significant progress achieved by controlling these degrees of freedom. Two breakthroughs are reviewed for constructing sophisticated structures of CP frameworks, especially in dimensional crossover regions. The first is the synthesis of quasi one-dimensional halogen-bridged coordinative tubes by applying state-of-the-art techniques of coordination chemistry. The electronic state of the coordinative tube was studied by structural, spectroscopic and theoretical methods and found to be distinct from conventional one-dimensional systems. The second breakthrough is the achievement of a quasi-two-dimensional architecture by combining Langmuir-Blodgett and layer-by-layer methods. Two-dimensional LB CP films were prepared on liquid; the films were stacked layer by layer, and a crystalline quasi-two-dimensional structure was constructed. This review also covers the design of the environment of the inner pore, where hydrogen bond networks with various acidic sites were modified. By appropriate design of the hydrogen bond network, proton-conductive CPs are invented, which are summarized in this review. Types of proton donor sites are discussed and classified, and superprotonic conductive CPs were achieved in these investigations. These results will provide new strategies for constructing functional materials for smart devices. © 2013 The Royal Society of Chemistry. Source

Kaempferol glycosides can be hydrolyzed to their aglycone kaempferol during cooking under acidic conditions and in the oral cavity and the intestine by glycosidases. Kaempferol was oxidised by nitrite under acidic conditions (pH 2.0) to produce nitric oxide (NO), and the nitrite-induced oxidation of kaempferol was enhanced and inhibited by 10 and 100 mg of starch ml 1, respectively. The opposite effects of starch were discussed by considering the binding of kaempferol to starch and starch-dependent inhibition of the accessibility of nitrous acid to kaempferol. Kaempferol inhibited α-amylase-catalysed starch digestion by forming starch/kaempferol complexes, and the inhibitory effects increased in the order of amylopectin < soluble starch < amylose. The different effects of kaempferol were discussed to be due to the difference in binding sites of kaempferol between amylose and amylopectin. From the present study, dual-function of kaempferol became apparent in the digestive tract. © 2013 Elsevier Ltd. All rights reserved. Source

Sakaue T.,Kyushu University | Brochard-Wyart F.,University Pierre and Marie Curie
ACS Macro Letters | Year: 2014

We propose a novel characterization method of randomly branched polymers based on the geometrical property of such objects in confined spaces. The central idea is that randomly branched polymers exhibit a passing/clogging transition across the nanochannel as a function of the channel size. This critical channel size depends on the degree of the branching, whereby allowing the extraction of the branching information of the molecule. © 2014 American Chemical Society. Source

Takeda M.,Kinki University | Okamoto I.,Kinki University | Okamoto I.,Kyushu University | Nakagawa K.,Kinki University
Journal of Thoracic Oncology | Year: 2014

INTRODUCTION:: Somatic mutations in the epidermal growth factor receptor gene (EGFR) are associated with a marked therapeutic response to EGFR-tyrosine kinase inhibitors (TKIs) in patients with advanced non-small cell lung cancer (NSCLC). Clinical indicators of the likely survival benefit of EGFR-TKI treatment in NSCLC patients with EGFR mutations have not been identified, however. We therefore evaluated progression-free survival (PFS) and overall survival (OS) according to tumor response and tumor shrinkage pattern in such patients. METHODS:: Among 145 EGFR mutation-positive NSCLC patients treated with EGFR-TKIs, 68 individuals were selected for analysis. RESULTS:: Of the 68 selected patients, 6 achieved a complete response (CR), 42 a partial response (PR), and 14 stable disease (SD). Both PFS and OS were significantly longer in patients who achieved a CR or PR than in those who experienced SD. Multivariate analysis showed that a response (CR or PR) to EGFR-TKIs was significantly associated with both PFS and OS. Among the CR/PR group, the median maximal tumor shrinkage relative to baseline was 56%, and the median time to response (TTR) was 4.2 weeks. The subsets of these patients who experienced rapid tumor regression (TTR of ≤4.2 weeks) or a high degree of tumor shrinkage (≥56%) did not show a more favorable PFS or OS compared with those who experienced slow tumor regression or a low degree of tumor shrinkage. CONCLUSION:: Response (CR or PR) may represent the optimal surrogate for efficacy among EGFR mutation-positive NSCLC patients treated with EGFR-TKIs. Copyright © 2013 by the International Association for the Study of Lung. Source

Shen M.,University of Pittsburgh | Ishimatsu R.,University of Pittsburgh | Ishimatsu R.,Kyushu University | Kim J.,University of Pittsburgh | Amemiya S.,University of Pittsburgh
Journal of the American Chemical Society | Year: 2012

Here we report on the unprecedentedly high resolution imaging of ion transport through single nanopores by scanning electrochemical microscopy (SECM). The quantitative SECM image of single nanopores allows for the determination of their structural properties, including their density, shape, and size, which are essential for understanding the permeability of the entire nanoporous membrane. Nanoscale spatial resolution was achieved by scanning a 17 nm radius pipet tip at a distance as low as 1.3 nm from a highly porous nanocrystalline silicon membrane in order to obtain the peak current response controlled by the nanopore-mediated diffusional transport of tetrabutylammonium ions to the nanopipet-supported liquid-liquid interface. A 280 nm × 500 nm image resolved 13 nanopores, which corresponds to a high density of 93 nanopores/μm 2. A finite element simulation of the SECM image was performed to assess quantitatively the spatial resolution limited by the tip diameter in resolving two adjacent pores and to determine the actual size of a nanopore, which was approximated as an elliptical cylinder with a depth of 30 nm and major and minor axes of 53 and 41 nm, respectively. These structural parameters were consistent with those determined by transmission electron microscopy, thereby confirming the reliability of quantitative SECM imaging at the nanoscale level. © 2012 American Chemical Society. Source

Sonoda K.,Kyushu University
Histology and Histopathology | Year: 2011

The expression of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is associated with aggressive characteristics and poor overall survival for 15 different human malignancies. The correlation between RCAS1 expression and several clinicopathological variables, including tumor size, clinical stage, invasion depth and lymph node metastasis highlights this molecule's clinical significance. RCAS1 is a biomarker because: (1) its concentration in serum or pleural effusion is significantly higher in cancer patients; (2) its level is associated with treatment response; and (3) high RCAS1-valued serum from cancer patients inhibits growth of RCAS1 putative receptor-expressing K562 cells. RCAS1 is secreted by ectodomain shedding and induces apoptosis in peripheral lymphocytes and natural killer (NK) cells. Although its putative receptor and mechanism of apoptosis induction remain undefined, RCAS1 is believed to help tumor cells evade immune surveillance. RCAS1 expression is also related to changes in extracellular matrix characteristics, reduction of vimentin-positive stromal cells, and increased microvessel density (MVD), all suggesting that RCAS1 may induce connective tissue remodeling. Further exploration of RCAS1 biological function will facilitate development of novel therapeutic strategies that target RCAS1. Source

Using a 46-year-long dataset of the thermospheric density during 1967-2012, we examined the inter-annual variability in the thermosphere at 400 km and its potential connection to El-Nino Southern Oscillation (ENSO) and stratospheric Quasi-Biennial Oscillation (QBO). Wavelet analysis reveals two major modes of the thermosphere inter-annual oscillation, with the slower mode having an average period of ∼64 months and the faster mode of ∼28 months. The slower mode bears high coherence with the ENSO during 1982-2012, while the faster mode is found to vary coherently with the QBO around 1972, 1982 and 2002. Further examination reveals that the coherence between QBO and the faster mode is significantly influenced by their common coherent variation with the solar flux, while high coherence between the slower mode and ENSO is much less contaminated. Therefore, we conclude that the 28-month periodicity in thermospheric density may be caused by both QBO and solar radiation, whereas the 64-month periodicity possibly arises mainly from ENSO processes, with little/small contribution from solar radiation. © 2016 Liu. Source

Phuong N.L.,Ho Chi Minh City University of Natural Sciences | Ito K.,Kyushu University
Building and Environment | Year: 2015

Breathing is one of the most essential processes in the human body. The basic functions of breathing are to exchange gases (supplying oxygen from ambient air and removing carbon dioxide from the blood) and also to exchange heat and moisture through mucous surfaces of the airway. During an average lifetime, human beings experience significant exposure to indoor air and countless of contaminants/particles via inhalation. In this study, experimental and numerical results of flow fields in a realistic respiratory model were obtained. Flow patterns in a realistic replica model of the human respiratory tract were investigated with particle image velocimetry (PIV) under three constant breathing conditions; 7.5, 15 and 30 L/min. Computational fluid dynamics (CFD) analyses were conducted on turbulent models with boundary conditions corresponding to the experimental models. We used four RANS turbulence models to predict airflow in a realistic human airway model: two low Reynolds (Re) number-type k-ε turbulence models, RNG k-ε model, and the SST k-ω model. The CFD results were compared with PIV data and showed relatively good agreement in trachea region in all cases. © 2015. Source

Ebihara Y.,Kyoto University | Tanaka T.,Kyushu University
Journal of Geophysical Research A: Space Physics | Year: 2015

Initial brightening of the aurora is an optical manifestation of the beginning of a substorm expansion and is accompanied by large-amplitude upward field-aligned currents (FACs). Based on global magnetohydrodynamic simulation, we suggest the possible generation mechanism of the upward FAC that may manifest the initial brightening. (1) A formation of the near-Earth neutral line (NENL) releases the tension force that accelerates plasma earthward. (2) The earthward (perpendicular) flow is converted to a field-aligned flow when flow braking takes place. (3) A high-pressure region propagates earthward along a field line. (4) The off-equatorial high-pressure region pulls in and discharges ambient plasma, which generates a flow vorticity around it. (5) Region 1-sense FAC is generated in the upper part of the off-equatorial high-pressure region. (6) The upward FAC is connected with the ionosphere in the center of the Harang discontinuity, causing the initial brightening. Additional dynamo is generated in the near-Earth region, which transmits electromagnetic energy. Upward FAC that manifests the initial brightening seems to be necessarily originated in the near-Earth off-equatorial region where the magnitude of the perpendicular (diamagnetic) current is relatively small in comparison with that of the FAC. Near the equatorial plane, the perpendicular current is comparable to or larger than FAC so that a current line is diverted from a magnetic field line and that the FAC generated near the equatorial plane is not necessarily connected with the ionosphere. The proposed mechanism occurs regardless of the location of the NENL and may explain some of auroral forms. ©2015. The Authors. Source

Nong N.V.,National Changhua University of Education | Liu C.-J.,National Changhua University of Education | Ohtaki M.,Kyushu University
Journal of Alloys and Compounds | Year: 2011

Misfit-layered oxides Ca3-xLnxCo4O 9+δ with Ln = Dy, Er, Ho, and Lu were synthesized using solid state reactions. The resulting samples were hot-pressed (HP) at 1123 K in air for 2 h under a uniaxial pressure of 60 MPa. Thermoelectric properties of Ca3-xLnxCo4O9+δ were investigated up to 1200 K. Both the Seebeck coefficient and electrical resistivity increase upon Ln substitution for Ca. Among the Ln-doped samples, the magnitude of Seebeck coefficient tends to increase with decreasing ionic radius of Ln3+. The Ln-doped samples exhibit a lower thermal conductivity than the non-doped one due to a decrease of their lattice thermal conductivity. The dimensionless figure of merit, ZT, reaches 0.36 at 1073 K for the Ca2.8Lu0.2Co4O9+δ sample, which is about 1.6 times larger than that for the non-doped counterpart. © 2010 Elsevier B.V. All rights reserved. Source

Fujioka K.,Kyushu University
Theoretical Computer Science | Year: 2013

Among the variety of representation theorems for context-free languages, the Chomsky-Schützenberger theorem is unique in that it consists of Dyck languages, regular languages, and simple operations. In the present paper, we obtain some characterizations of and representation theorems for languages in the Chomsky hierarchy by using insertion systems, strictly locally testable languages, and morphisms in the framework of the Chomsky-Schützenberger theorem. For instance, each context-free language L can be represented in the form L=h(L(γ)∩R), where γ is an insertion system of weight (1,1), R is a strictly 2-testable language, and h is a morphism. In contrast, if R is instead a strictly 1-testable language, the class of languages generated is a proper subclass of context-free languages and incomparable with the class of regular languages. © 2012 Elsevier B.V. All rights reserved. Source

Yeoh W.,New Mexico State University | Yokoo M.,Kyushu University
AI Magazine | Year: 2012

Broadly, distributed problem solving is a subfield within multiagent systems, where the focus is to enable multiple agents to work together to solve a problem. These agents are often assumed to be cooperative, that is, they are part of a team or they are self-interested but incentives or disincentives have been applied such that the individual agent rewards are aligned with the team reward. We illustrate the motivations for distributed problem solving with an example. Imagine a decentralized channel-allocation problem in a wireless local area network (WLAN), where each access point (agent) in the WLAN needs to allocate itself a channel to broadcast such that no two access points with overlapping broadcast regions (neighboring agents) are allocated the same channel to avoid interference. Figure 1 shows example mobile WLAN access points, where each access point is a Create robot fitted with a wireless CenGen radio card. Figure 2a shows an illustration of such a problem with three access points in a WLAN, where each oval ring represents the broadcast region of an access point. Copyright © 2012, Association for the Advancement of Artificial Intelligence. All rights reserved. Source

Yumimoto K.,Japan Meteorological Agency | Takemura T.,Kyushu University
Geophysical Research Letters | Year: 2011

We developed a new ensemble-based data-assimilation system based on a global aerosol climate model and performed a 1-month assimilation experiment using satellite optical measurements from MODIS onboard TERRA and AQUA to estimate the direct radiative effect (DRE) of aerosols. Using the assimilated data field, monthly averaged optical thickness (AOT) was estimated to be 0.15 ± 0.030 (a 52.0% increase over a priori), and the root mean-square difference (RMSD) between modeled values and MODIS measurements was reduced by 28.4%. Independent validation using globally distributed AERONET measurements showed that the a posteriori data achieved better agreement with 82.5% of 80 AERONET sites. However, improvements in ngstrm exponents were limited (50.0% of sites). Using the assimilated aerosol field, we modeled the aerosol DRE. A posteriori whole-and clear-sky DREs at the top of the atmosphere were estimated to be-1.1 ± 0.35 and-2.5 ± 0.49 W/m2, respectively, in May 2007 and were close to previously reported measurement-based estimates. Copyright 2011 by the American Geophysical Union. Source

Masai H.,Tokyo Metropolitan Institute of Medical Science | Tanaka T.,Tokyo Metropolitan Institute of Medical Science | Kohda D.,Kyushu University
BioEssays | Year: 2010

In bacteria, PriA protein, a conserved DEXH-type DNA helicase, plays a central role in replication restart at stalled replication forks. Its unique DNA-binding property allows it to recognize and stabilize stalled forks and the structures derived from them. Cells must cope with fork stalls caused by various replication stresses to complete replication of the entire genome. Failure of the stalled fork stabilization process and eventual restart could lead to various forms of genomic instability. The low viability of priA null cells indicates a frequent occurrence of fork stall during normal growth that needs to be properly processed. PriA specifically recognizes the 30-terminus of the nascent leading strand or the invading strand in a displacement (D)-loop by the three-prime terminus binding pocket (TT-pocket) present in its unique DNA binding domain. Elucidation of the structural basis for recognition of arrested forks by PriA should provide useful insight into how stalled forks are recognized in eukaryotes. © 2010 Wiley Periodicals, Inc. Source

Takaoka Y.,Kyoto University | Ojida A.,Kyushu University | Hamachi I.,Kyoto University | Hamachi I.,Japan Science and Technology Agency
Angewandte Chemie - International Edition | Year: 2013

The modification of proteins with synthetic probes is a powerful means of elucidating and engineering the functions of proteins both invitro and in live cells or invivo. Herein we review recent progress in chemistry-based protein modification methods and their application in protein engineering, with particular emphasis on the following four strategies: 1)the bioconjugation reactions of amino acids on the surfaces of natural proteins, mainly applied in test-tube settings; 2)the bioorthogonal reactions of proteins with non-natural functional groups; 3)the coupling of recognition and reactive sites using an enzyme or short peptide tag-probe pair for labeling natural amino acids; and 4)ligand-directed labeling chemistries for the selective labeling of endogenous proteins in living systems. Overall, these techniques represent a useful set of tools for application in chemical biology, with the methods 2-4 in particular being applicable to crude (living) habitats. Although still in its infancy, the use of organic chemistry for the manipulation of endogenous proteins, with subsequent applications in living systems, represents a worthy challenge for many chemists. Labels of the reconstruction: Chemical modification of proteins with synthetic probes is a powerful means of elucidating protein functions in live cells and of influencing these functions. New reactions that can be successfully applied in living systems represent a worthy challenge to organic chemistry, especially as the labeling and manipulation of endogenous proteins in their natural habitats is currently at an early stage. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Takahashi-Yanaga F.,Kyushu University | Kahn M.,University of Southern California
Clinical Cancer Research | Year: 2010

The Wnt signaling pathways have been conserved throughout evolution and regulate cell proliferation, morphology, motility, and fate during embryonic development. These pathways also play important roles throughout adult life to maintain homeostasis of tissues including skin, blood, intestine, and brain by regulating somatic stem cells and their niches. Aberrant regulation of the Wnt pathway leads to neoplastic proliferation in these same tissues. It has been suggested that Wnt signaling is also involved in the regulation of cancer stem cells (CSC), because there are many similarities in the signaling pathways that regulate normal adult stem cells and CSC. In this Perspective, we have focused on the Wnt/β-catenin signaling pathway, which is the most intensively studied and best characterized Wnt signaling pathway. We provide an overview on the function of the Wnt/β-catenin signaling pathway in CSC, and the possibility of the development of novel therapeutics to target this pathway. ©2010 AACR. Source

Arakawa K.,Kyushu University
Tribology International | Year: 2016

This study investigated the dynamic sliding friction of polyurethane (PU) rubber samples on an inclined smooth transparent polymethylmethacrylate (PMMA) surface with a thin layer of silicone oil. The sliding velocity increased during the initial stages of sliding and approached a constant value toward the latter stages. To describe the changes in velocity observed, the present study developed an analytical model based on Couette flow with no pressure gradient and indicated that the model could predict important changes in velocity. These findings suggest that dynamic friction force is dependent on both the sliding velocity and the contact area, and that the behavior is similar to that given by Stokes' law, which describes the falling velocity of a particle in a viscous fluid. © 2015 Elsevier B.V. All rights reserved. Source

Yamashita M.,Kyushu University | Suzuki I.,University of Wisconsin - Milwaukee
Theoretical Computer Science | Year: 2010

In a system in which anonymous mobile robots repeatedly execute a "Look-Compute-Move" cycle, a robot is said to be oblivious if it has no memory to store its observations in the past, and hence its move depends only on the current observation. This paper considers the pattern formation problem in such a system, and shows that oblivious robots can form any pattern that non-oblivious robots can form, except that two oblivious robots cannot form a point while two non-oblivious robots can. Therefore, memory does not help in forming a pattern, except for the case in which two robots attempt to form a point. Related results on the pattern convergence problem are also presented. © 2010 Elsevier B.V. All rights reserved. Source

Influenza A virus is the etiological agent of a highly contagious acute respiratory disease that causes epidemics and considerable mortality annually. It has become increasingly evident that influenza viral infection is recognized by at least three classes of pattern-recognition receptors, including TLR-7, the retinoic acid inducible gene-I and nucleotide-binding domain and leucine-rich-repeat-containing protein 3, a member of the Nod-like receptor family. This article highlights the roles of different types of innate immune receptors in influenza virus immunity versus immunopathology. © 2010 Expert Reviews Ltd. Source

Ueda T.,Kyushu University
Biochimica et Biophysica Acta - Proteins and Proteomics | Year: 2014

Biotherapeutics have been clinically used since the 1990s. Recently, next-generation optimized biotherapeutics, which are expected to act on the same molecular target as their predecessors with further properties by antibody-drug conjugation, radiolabeling, PEGylation and glycoconjugation, are on the market. This article reviews recent next-generation optimized biotherapeutics. Moreover, since trials of protein engineering for biotherapeutics have been conducted, these preclinical approaches are also described. This article is part of a Special Issue entitled: Recent advances in molecular engineering of antibody. © 2014 Elsevier B.V. Source

Kuwahara Y.,Kyushu University
Geochimica et Cosmochimica Acta | Year: 2011

The dissolution behavior of the barite (001) surface in pure water at 30°C was investigated using in situ Atomic Force Microscopy (AFM), to better understand the dissolution mechanism and the microtopographical changes that occur during the dissolution, such as steps and etch pits. The dissolution of the barite (001) surface started with the slow retreat of steps, after which, about 60min later, the steps of one unit cell layer or multi-layers became two-step fronts (fast "f" and slow "s" steps) with a half-unit cell layer showing different retreat rates. The "f" step had a fast retreat rate (≈(14±1)×10-2nm/s) and tended to have a jagged step edge, whereas the "s" step (≈(1.8±0.1)×10-2nm/s) had a relatively straight front. The formation of the "f" steps led to the formation of a new one-layer step, where the front of the "s" step was overtaken by that of the immediate underlying "f" step. The "f" steps also led to the decrease of the steps and the increase in the percentage of stable steps parallel to the [010] direction during the dissolution. Etch pits, which could be observed after about 90min, were of three types: triangular etch pits with a depth of a half-unit cell, shallow etch pits, and deep etch pits. The triangular etch pits were bounded by the step edges parallel to [010], [120], and [12̄0] and had opposite orientations in the upper half and lower half layers. Shallow etch pits that had a depth of two or more half-unit cell layers had any two consecutive pits pointing in the opposite direction of each other. The triangular etch pit appeared to grow by simultaneously removal of a row of ions parallel to each direction from the three step edges. At first, deep etch pits were elongated in the [010] direction with a curved outline and then gradually developed to an angular form bounded by the {100}, {310}, and (001) faces. The retreat rate of the (001) face was much slower than those of the {100} and {310} and tended to separate into two rates ((0.13±0.01)×10-2nm/s for the deep etch pits derived from a screw dislocation and (0.07±0.01)×10-2nm/s for those from other line defects).The changes in the dissolution rate of a barite (0. 0. 1) surface during the dissolution were estimated using the retreat rates and densities of the various steps as well as the growth rates, density, and areas of the lateral faces of the deep etch pits that were obtained from this AFM analysis. Our results showed that the dissolution rate of the barite (0. 0. 1) surface gradually increased and approached the bulk dissolution rate because of the change in the main factor determining the dissolution rate from the density of the steps to the growth and the density of the deep etch pits on the surface. © 2010 Elsevier Ltd. Source

Sasaki Y.,Kyushu University
Geophysics | Year: 2013

The application of the marine controlled-source electromagnetic (CSEM) technique for shallow-water hydrocarbon exploration is challenged by the effect of an airwave that masks the response from the reservoir at depth. We applied Gauss-Newton-based 3D inversion method to synthetic CSEM and magnetotelluric (MT) data to demonstrate the capability of 3Dinversion to recover thin resistive targets in shallow-water environments. The experiment on the model with water depth of 300 m shows that the target signals at 0.25 Hz are significant enough to resolve the reservoir at a burial depth of 1 km for the given noise level (6% of the electric-field amplitude). For the 100-m water depth case, the high-resistivity zone recovered is located much deeper and thicker than the true reservoir, suggestingthat the airwave component obscures the target signal more seriously. However, inverting inline and broadside data together or adding inline data at a different frequency (0.1 Hz) is quite effective in improving the resolution to the thin resistive target and more sothan simultaneously inverting inline CSEM and MT data. © 2012 Society of Exploration Geophysicists. Source

Sakai S.,Kyushu University
Advances in Experimental Medicine and Biology | Year: 2010

Reduction in the diameter of cell-enclosing capsules has a practical application in cell therapy as it induces beneficial effects such as higher molecular exchangeability between the enclosed cells and the ambient environment, as well as higher mechanical stability and biocompatibility. Subsieve-size capsules are capsules of less than 100 μm in diameter, which are approximately one tenth the size of conventional cell-enclosing microcapsules. Such small capsules can be prepared using the emulsion system obtained via the jetting process in which a cell-suspending polymer solution is extruded into an ambient coflowing water-immiscible liquid from a needle several hundred micrometers in diameter. The capsule size can be controlled by changing the velocity of the polymer solution and the ambient water-immiscible liquid. The emulsification process does not significantly affect viability of mammalian cells enclosed in the resultant subsieve-size capsules. In this chapter we will review the technique of subsieve-size capsule production and the effects of diameter reduction on the enclosed cells and properties of the capsules. © 2010 Landes Bioscience and Springer Science+Business Media. Source

Spatial patterns and morphology of hydrothermal vents and the occurrence of vent-associated megafauna were investigated in the back-arc basin system of the Okinawa Trough, western Pacific. Amongst hydrothermal vent fields located on the rising slopes to the NE and S of the basin, the Iheya North area has been subjected to a series of intensive diving surveys. Hydrothermal vents demonstrated concentrated patterns of distribution on different spatial scales. In Iheya North, the majority of vents occurred in lines parallel to the NE to W/SW alignment of the spreading axis, within a radius of ca. 200 m around the most active sulphide structure with the highest recorded fluid temperature of over 300°C. The morphology of hydrothermal vents varied greatly from an incipient flat rock with crevices to a 20- to 30-m-tall, multi-flanged structure with concomitant variation in the distribution and abundance of vent-associated megafauna, particularly a galatheid Shinkaia crosnieri and Bathymodiolus mussels. Comparison of active and inactive vents revealed that the spatial extent of Shinkaia 'aggregation' (a group of individuals with short nearest-neighbour distances) effectively defined a habitat unit of this species, and active hydrothermal chimneys contained more of these units, leading to greater spatial occupancy by Shinkaia. Given the temporally unstable nature of vent structures as recognised by repeated surveys, vent assemblages are thought to be closely dictated by the spatio-temporal dynamics of vents in the Okinawa Trough back-arc system. © 2011 The Oceanographic Society of Japan and Springer. Source

Araki K.,Kyoto Sangyo University | Inaba K.,Kyushu University
Antioxidants and Redox Signaling | Year: 2012

Significance: Disulfide bond formation is an essential reaction involved in the folding and maturation of many secreted and membrane proteins. Both prokaryotic and eukaryotic cells utilize various disulfide oxidoreductases and redox-active cofactors to accelerate this oxidative reaction, and higher eukaryotes have diversified and refined these disulfide-introducing cascades over the course of evolution. Recent Advances: In the past decade, atomic resolution structures have been solved for an increasing number of disulfide oxidoreductases, thereby revealing the structural and mechanistic basis of cellular disulfide bond formation systems. Critical Issues: In this review, we focus on the evolution, structure, and regulatory mechanisms of endoplasmic reticulum oxidoreductin 1 (Ero1) family enzymes, the primary disulfide bond-generating catalysts in the endoplasmic reticulum (ER). Detailed comparison of Ero1 with other oxidoreductases, such as Prx4, QSOX, Erv1/2, and disulfide bond protein B (DsbB), provides important insight into how this ER-resident flavoenzyme acts in a regulated and specific manner to maintain redox and protein homeostasis in eukaryotic cells. Future Directions: Currently, it is presumed that multiple pathways in addition to that mediated by Ero1 cooperate to achieve oxidative folding of many secretory and membrane proteins in mammalian cells. The important open question is how each oxidative pathway works distinctly or redundantly in response to various cellular conditions. Antioxid. Redox Signal. 16, 790-799. © Copyright 2012, Mary Ann Liebert, Inc. 2012. Source

Background: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin-producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified as the main duct type (MD-IPMN) and the branch duct type (BD-IPMN) according to the location of involvement, and into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to the histomorphological and immunohistochemical characteristics. Mucin core protein expression correlates with the biological behavior and prognosis of the tumor. DNA analysis has shown that IPMN is associated with a number of gene mutations, but the roles of many of these mutations require further investigation. Most patients with MD-IPMN undergo tumor resection. Patients with BD-IPMN who do not undergo resection may develop malignant change, and concomitant separate pancreatic cancer occurs in 2-10% of patients with IPMN. Patients with a strong family history may develop multiple BD-IPMNs as well as concomitant pancreatic cancer. Malignant changes are relatively easy to detect, especially by endoscopic ultrasonography (EUS), but the optimal surveillance protocol is currently unclear. Key Messages: The 2012 guidelines for the management of IPMN recommend that patients with 'high-risk stigmata' (obstructive jaundice, enhanced solid component, and main pancreatic duct size ≥10 mm) should undergo resection. Patients with 'worrisome features' (cyst size ≥3 cm, thickened enhanced cyst walls, non-enhanced mural nodules, main pancreatic duct size 5-9 mm, abrupt change in main pancreatic duct caliber with distal pancreatic atrophy, lymphadenopathy, and clinical acute pancreatitis) should be evaluated by EUS. EUS is a more sensitive test than computed tomography or magnetic resonance imaging for the early detection of malignancy. Conclusions: Most patients with MD-IPMN should undergo tumor resection. Patients with BD-IPMN who do not undergo resection should undergo careful surveillance including EUS for the early detection of malignant change and separate pancreatic cancer. © 2015 S. Karger AG, Basel. Source

Nagafuchi S.,Kyushu University
Microbiology and Immunology | Year: 2010

Recently, accumulating evidence has suggested that B cell depletion therapy with rituximab is effective not only in autoantibody-associated, but also in T cell-mediated, autoimmune diseases. It is likely that B cells play an important role in regulating the extent of immune response in both physiological and pathological conditions. When a severe infection occurs, pathogens spread throughout the bloodstream. B cells in the blood capture the pathogens, via their specific antigen receptors (surface immunoglobulins), then present the specific antigen to T cells in the spleen, thus increasing the degree of T-cell immune responses to systemic infection. Similarly, in the exacerbation stage of autoimmunity, a large amount of autoantigens may be released into the blood and be captured by autoantigen specific B cells, and this may be followed by presentation of the antigen to CD4 positive autoreactive T cells resulting in extensive activation and proliferation of autoreactive T cells. Thus, it has been suggested that B-cell depletion therapy for autoimmune diseases is most useful for the "vicious cycle" phase of autoreactive immune response. The recognition ofthis paradigm for the role ofB cells in regulating the magnitude ofimmune response will help to facilitate both basic and clinical research on the regulation of immune responses. © 2010 The Societies and Blackwell Publishing Asia Pty Ltd. Source

Oshita Y.,Kyushu University
Energy Economics | Year: 2012

To address the problem of global warming, it is important to identify the supply chain paths that drive changes in life cycle CO 2 emissions and provide both policy makers and decision makers with the information on the critical paths in order to efficiently reduce the CO 2 emissions. In this article, I extract and analyze the factors and key supply chains involved in changes in CO 2 emissions associated with Japan's overall demand from 1990 to 2000 using the Structural Path Decomposition (SPD) method applied to the 1990-1995-2000 linked Japanese environmental input-output tables at the four-digit commodity classification level. The results reveal that the volume of CO 2 emissions increased as a result of changes in the input structure of the electricity of the services sector, such as "electricity → amusement and recreation facilities → household demand", "electricity → retail trade → household demand" and "electricity → public administration (local) → local government demand", indicating increasing dependence of services on energy input. I also find that the final demand shift changed CO 2 emissions, for example the rise in demand for integrated circuits in exports has contributed to increasing CO 2 emissions generated from electricity, the fall in demand for frozen fish and shellfish in household demand has contributed to decreasing CO 2 emissions from marine fisheries. © 2011 Elsevier B.V. Source

Sakamoto A.,Kyushu University
Indian Journal of Orthopaedics | Year: 2014

Dedifferentiated chondrosarcomas are cartilaginous tumors that consist of two distinguishable components, a lowgrade chondrosarcoma (chondrogenic) component and a highgrade dedifferentiated (anaplastic) component. The tumor cells in both components seem to originate from a single precursor, but there are a substantial number of genetic alterations in the anaplastic component. The underlying mechanism of dedifferentiation is unknown, but cell cycle regulators p16, p53 and retinoblastoma appear to have important roles in tumor development and dedifferentiation. In this article, molecular pathogenesis of dedifferentiated chondrosarcomas is reviewed. Source

Sakaue T.,Kyushu University | Sakaue T.,Japan Science and Technology Agency
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

Flexible polymers such as long DNA, RNA molecules, and proteins, can pass through a narrow pore whose size is comparable to their molecular thickness. We highlight the richness and complexity involved in the dynamics of this unique mode of molecular transport, called translocation, actively driven by external forces. In particular, the process takes place in the condition far from equilibrium accompanying of large conformational distortion in line with the propagation of the tensile force along the chain backbone. A general framework is proposed, which captures such essential features, whereby can account for reported various experimental data from a unified viewpoint. © 2010 The American Physical Society. Source

Hata J.,Kyushu University
Arteriosclerosis, Thrombosis, and Vascular Biology | Year: 2016

OBJECTIVE—: Angiopoietin-like protein 2 (ANGPTL2), a proinflammatory mediator, has been reported to accelerate the development of insulin resistance, endothelial dysfunction, and atherosclerosis in mice. However, no cohort studies have examined the relationship between serum ANGPTL2 levels and the development of cardiovascular disease (CVD) in a general population. APPROACH AND RESULTS—: A total of 3005 community-dwelling Japanese aged ≥40 years without a history of CVD were divided into 4 groups according to the quartiles of serum ANGPTL2 concentrations (Q1, lowest and Q4, highest) and followed up for 10 years. The hazards ratios and their 95% confidence intervals for the development of CVD (coronary heart disease or stroke) were estimated using a Cox proportional hazards model. During the follow-up, 219 first-ever CVD events were observed. The risk of CVD increased significantly with elevating ANGPTL2 levels after adjustment for age, sex, serum total cholesterol, use of lipid-lowering agents, ECG abnormalities, smoking habits, alcohol intake, and regular exercise (hazards ratios [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.27 [0.80–2.04]; Q3, 1.48 [0.95–2.32]; and Q4, 1.85 [1.20–2.85]; P=0.003 for trend). After additional adjustment for metabolic syndrome components and serum high-sensitivity C-reactive protein levels as an inflammatory marker, the association was attenuated but remained significant (hazards ratios [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.21 [0.76–1.94]; Q3, 1.38 [0.87–2.17]; and Q4, 1.66 [1.05–2.60]; P=0.02 for trend). CONCLUSIONS—: Our findings suggest that elevated serum ANGPTL2 levels are a novel risk factor for the development of CVD in the general population. This association is partially mediated by metabolic disorders and inflammation. © 2016 American Heart Association, Inc. Source

Chen D.,Massachusetts Institute of Technology | Bishop S.R.,Massachusetts Institute of Technology | Bishop S.R.,Kyushu University | Tuller H.L.,Massachusetts Institute of Technology
Advanced Functional Materials | Year: 2013

While the properties of functional oxide thin films often depend strongly on their oxygen stoichiometry, there have been few ways to extract this information reliably and in situ. In this work, the derivation of the oxygen non-stoichiometry of dense Pr0.1Ce0.9O2-δ thin films from an analysis of chemical capacitance obtained by impedance spectroscopy is described. Measurements are performed on electrochemical cells of the form Pr0.1Ce0.9O2-δ/Y 0.16Zr0.84O1.92/Pr0.1Ce 0.9O2-δ over the temperature range of 450 to 800 °C and oxygen partial pressure range of 10-5 to 1 atm O 2. With the aid of a defect equilibria model, approximations relate chemical capacitance directly to non-stoichiometry, without need for fitting parameters. The calculated non-stoichiometry allows extraction of the thermodynamic constants defining defect generation. General agreement of these constants with bulk values derived by thermogravimetric analysis is found, thereby confirming the suitability of this technique for measuring oxygen non-stoichiometry of thin oxide films. Potential sources of error observed in earlier chemical capacitance studies on perovskite structured oxide films are also discussed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Rhabdoid tumor is characterized by rhabdoid cells and shows complete loss of SMARCB1/INI1 protein expression. In existing classifications, the diagnostic synonyms vary depending on the anatomic site: rhabdoid tumors in the central nervous system or extra-central nervous system are, respectively, classified as atypical teratoid/rhabdoid tumor or malignant rhabdoid tumor. In this study, we analyzed the histological, immunohistochemical, microRNA, and clinicopathological statuses of tumors initially diagnosed as malignant rhabdoid tumor (n=33), atypical teratoid/rhabdoid tumor (n=11), and pediatric undifferentiated/unclassified sarcoma (n=8) with complete loss of SMARCB1/INI1 expression, and considered the possibility of their histological reclassification. Our analysis indicated that the tumors could be histologically reclassified into three groups: conventional-type tumors resembling malignant rhabdoid tumor, atypical teratoid/rhabdoid-type tumors resembling atypical teratoid/rhabdoid tumor, and small cell-type tumors resembling malignant lymphoma. The reclassified conventional type was composed of 27 malignant rhabdoid tumors and 9 atypical teratoid/rhabdoid tumors (36 cases). The atypical teratoid/rhabdoid type consisted of six malignant rhabdoid tumors, two atypical teratoid/rhabdoid tumors, and two undifferentiated/unclassified sarcomas (10 cases). The six cases of small cell type were made up of six undifferentiated/unclassified sarcomas. All of the available tumor specimens were positive for vimentin and epithelial marker (EMA, CAM5.2, or AE1/AE3). MicroRNA profiles were not significantly different between the conventional- and small cell-type tumors (Pearson's correlation coefficient: 0.888300 or 0.891388). There was no significant difference in overall survival between atypical teratoid/rhabdoid tumor and malignant rhabdoid tumor (P=0.16). In addition, there were no significant differences in survival between any of the reclassified combinations. In conclusion, we could classify eight tumors initially diagnosed as undifferentiated/unclassified sarcomas into two cases of atypical teratoid/rhabdoid type and six cases of small cell type. We suggest that reclassification of malignant rhabdoid tumors into three groups according to their histologic features rather than the traditional classification by sites of origin would be favorable for their histopathological diagnosis.Modern Pathology advance online publication, 24 June 2016; doi:10.1038/modpathol.2016.106. © 2016 United States & Canadian Academy of Pathology Source

Shi Y.G.,Harvard University | Tsukada Y.,Kyushu University
Cold Spring Harbor Perspectives in Biology | Year: 2013

Histone methylation is a key element of the eukaryotic epigenome. Since the discovery of the first histone demethylase (HDM) in 2004, more than 20 demethylases have been identified and characterized. They belong to either the LSD family or the JmjC family, demonstrating the reversibility of all methylation states at almost all major histone lysine methylation sites. These findings ended decades of debate about the reversibility of histone methylation, representing a major breakthrough that shifts our understanding of epigenetic inheritance and regulation of genome function. Here, we summarize the discovery of HDMs and more recent advances, challenges, and future prospects of HDM research. © 2013 Cold Spring Harbor Laboratory Press; all rights reserved. Source

Sasaki S.,Kyushu University
Journal of Physical Chemistry B | Year: 2016

The hydration of alkyl-amide molecules in water is very important for understanding their solubility in water, which related to the phase behavior of polyamides including protein molecules in water. The 1H NMR signals of N-isopropylacrylamide (NIPA) in water were investigated for the purpose to reveal the hydration properties of NIPA in the aqueous HCl solutions, which change the phase behavior of aqueous NIPA solutions with HCl concentration as reported previously (J. Phys. Chem. B 2011, 115, 12905-12910). The following observations were revealed by the present studies. (1) The spin-spin coupling of the amide proton with the methyne proton in the HCl solution was observed when a half width of amide peak (∼ΔΔν)was less than about 10 Hz, but it was not when Δ νwas greater than 10 Hz. (2) The Δ νvalue of amide proton increased with an increase in a mole ratio of H2O to NIPA (rH2O) or with enlargement of the protonated hydration shell, which reduced the energy gap of the cis- and trans-conformations. (3) The Δ νvalue of H2O and its rH2O dependence in the 3 M HCl solution changed drastically between rH2O = 4.0 and 4.7, in which the hydrophilic hydration shell neighboring the amide extended to form the hydrophobic hydration shell. (4) The Δ νof methyl proton decreased monotonously with rH2O. This indicates an increase of the rotational mobility of methyl groups in the hydration shell. These results indicate that the elongating lifetime of cis-conformation of amide coupled with the shortened lifetime of double bonding C-N in amide induces the amide-methyne spin-spin-coupling transition and that the cationic state of amide stabilizes the hydrophobic hydration to induce the rotational free motion of amide C-N and the methyl groups. © 2015 American Chemical Society. Source

We retrospectively observed the clinical efficacy and safety of tocilizumab (TCZ) in 74 patients with rheumatoid arthritis (RA) at 13 hospitals, without any restrictions on disease duration or stage, treatment history, and other influencing factors. TCZ was infused by the approved method, and disease activity was evaluated every 4 weeks until week 24 using a joint disease activity score (DAS28). Remission and treatment response were categorised using European League Against Rheumatism (EULAR) definitions. We also analysed the impact of previous treatment with other biologics and of concomitant methotrexate (MTX) therapy on the efficacy of TCZ. At week 24, the DAS28 had improved from 5.5 to 2.7 and the EULAR remission rate was 55.2%. Good and moderate responses according to the EULAR criteria were obtained in 61 and 36% of the patients, respectively. The biologic-naïve group had a significantly better DAS28 (2.1 vs. 2.8) and a significantly higher "good" response rate (86% vs. 54%) than the biologic-exposed group. Although the TCZ + MTX treatment group and the TCZ monotherapy group had a good response rate of 71 and 48%, respectively, the difference was not significant. Based on these results, we conclude that TCZ is able to significantly alleviate disease symptoms in a wide range of patients with RA in a normal clinical context. Source

Kiyohara C.,Kyushu University
Gender medicine | Year: 2010

Several epidemiologic and molecular epidemiologic studies have indicated that, for a given number of cigarettes smoked, women may be at higher risk of lung cancer compared with men. The objective of this article was to address sex differences in lung cancer susceptibility, with special emphasis on genetic, biological, and sex-related hormonal factors. Using the search terms gender or sex difference in combination with lung cancer, susceptibility, survival, polymorphism, biomarker, and smoking, we conducted a review of the available literature in the MEDLINE, Current Contents, and Web of Science biomedical databases. Relevant English-language publications (January 1966-December 2009) on sex differences in lung cancer were identified. Higher levels of polycyclic aromatic hydrocarbon DNA adducts were observed in female lung cancer patients compared with their male counterparts, even though the level of tobacco carcinogens was lower among women than among men. DNA repair capacity was found to be lower in female lung cancer patients than in their male counterparts. A higher frequency of G-to-T transversion mutations in the tumor suppressor protein p53 gene has been observed in women compared with men. Non-small cell lung tumors in women appeared to be more likely than those in men to harbor K-ras, c-erbB-2, or epidermal growth factor receptor mutations. Sex differences have been identified in the expression of the cytochrome P4501A1 gene and gastrin-releasing peptide receptor gene, with women exhibiting higher gene expression than men for both of these genes. Evidence supporting a possible association between estrogen and lung cancer risk based on epidemiologic studies has not been consistent, but sex hormones may influence susceptibility to lung carcinogenesis. Women may be more susceptible to tobacco smoke and potentially more vulnerable to lung cancer development. If additional studies yield supporting evidence, researchers, the public, and policy makers should focus on ways to reduce the risk of lung cancer for women. Copyright © 2010 Excerpta Medica Inc. All rights reserved. Source

Kano A.,Kyushu University
Scientific Reports | Year: 2015

Studies of tumor models using syngeneic transplantation have advanced our understanding of tumor immunity, including both immune surveillance and evasion. Murine mammary carcinoma 4T1 cells secrete immunosuppressive soluble factors as demonstrated in splenocyte culture. Cultured primary splenocytes secrete IFN-γ, which was strikingly elevated when the cells were isolated from 4T1 tumor-bearing mice. The secretion of IFN-γ peaked a week after 4T1 inoculation and then declined. This reduction may be due to the relatively decreased lymphocytes and increased granulocytes in a spleen accompanied by splenomegaly with time after the 4T1 inoculation. IFN-γ production was further suppressed with the addition of the conditioned media from 4T1 cells to the splenocyte culture. This suppressive effect was more evident in the splenocytes isolated from mice that had 4T1 tumors for a longer period of time and was not observed in the conditioned medium either from CT26 cells or with splenocytes isolated from CT26 tumor-bearing mice. These results suggest that the IFN-γ suppression is 4T1 tumor-specific. The soluble factor(s) in the 4T1-conditioned media was a protein between 10 to 100 kDa. The cytokine tip assay demonstrated several known cytokines that negatively regulate immune responses and may be candidates for this immunosuppression activity. © 2015, Nature Publishing Group. All rights reserved. Source

Alam K.C.A.,East West University of Bangladesh | Saha B.B.,Kyushu University | Akisawa A.,Tokyo University of Agriculture and Technology
Applied Thermal Engineering | Year: 2013

An analytical investigation has been performed to study the possibility of application of solar cooling for the climatic condition of Tokyo, Japan. Silica gel-water adsorption cooling system has been taken into consideration for the present study and lumped parameter model is used to investigate the performance of the system. Based on the solar radiation data it is found that at least 15 collector (each of 2.415 m2) is required to achieve the required heat source temperature (around 85 °C) to run the cooling unit. It is also observed that the solar powered adsorption cooling unit provides cooling capacity around 10 kW at noon with base run conditions, while the system provides solar COP around 0.3, however, the solar collector size can be reduced by optimizing the cycle time. © 2012 Published by Elsevier Ltd. Source

Cicatricial contraction of preretinal fibrous membrane is a cause of severe vision loss in proliferative vitreoretinal diseases such as proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). In this study, vitreous samples from PDR or PVR patients caused significantly stronger contraction of hyalocyte-containing collagen gels, an in vitro model of cicatricial contraction, compared with those from nonproliferative controls. We elucidated the critical role of transforming growth factor-beta (TGF-beta) in the contractile effect and its underlying mechanisms mediating cicatricial contraction in proliferative vitreoretinal diseases at least in part. Fasudil, a potent and selective Rho-kinase (ROCK) inhibitor, almost completely blocked collagen gel contraction induced by vitreous samples. In addition, fasudil significantly inhibited the progression of experimental PVR in rabbit eyes in vivo. Rho/ROCK pathway, considered to be a key downstream mediator of TGF-beta and other contractile-inducing factors, might become a unique therapeutic target for the treatment of proliferative vitreoretinal diseases. Source

Purpose: To explore the efficacy and safety of pegaptanib sodium as maintenance therapy in Japanese patients with neovascular, age-related macular degeneration (AMD) after induction therapy (LEVEL-J study). Methods: A multi-center, prospective study was conducted at 21 medical institutions between 2009 and 2011. Of Japanese neovascular AMD patients with choroidal neovascularization who showed improvement in visual acuity (VA) with induction therapy, those who were scheduled for intravitreal injections of pegaptanib as maintenance therapy were recruited. LogMAR VA was assessed. Booster treatment (unscheduled treatment with other agents) was allowed during the study period if symptoms were judged to have worsened. Safety was assessed by monitoring adverse events and intraocular pressure (IOP). Results: Of 75 patients included in the analysis, 80 % completed the 54-week study period. Their mean age was 74.7 ± 6.9 years, and 54 patients (72.0 %) were men. The mean number of pegaptanib injections was 5.7 ± 2.6. Booster treatment was not required in 40 eyes (53.3 %). Mean logMAR VA was 0.61 ± 0.31 before induction therapy, 0.26 ± 0.24 before maintenance therapy, and 0.29 ± 0.28 at 54 weeks. No notable change in VA was observed during maintenance therapy. Adverse events were reported in 4 patients (5.3 %), including increased intraocular pressure, cancer, gallstones and recurrence of breast cancer, but mean IOP remained stable during maintenance therapy. Conclusions: The results of this exploratory study suggest that maintenance therapy with pegaptanib is potentially an effective and well-tolerated option in Japanese patients with neovascular AMD in whom induction therapy has been successful. © 2013 Japanese Ophthalmological Society. Source

Mujahid A.,Kyushu University
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology | Year: 2010

Mechanisms of thermogenic responses that play a role to maintain homeothermy during an early stage of neonatal chicks on acute cold exposure are scarcely studied as hatchlings are believed to be poikilothermic. However, chicks can attain the homeothermy during their subsequent growth after hatching. To identify thermogenic responses during neonatal stages of chicks (Gallus gallus) on acute cold exposure (12 °C, 3 h), changes in plasma corticosterone levels, thermogenesis, gene transcripts (avUCP and avPGC1α) in skeletal muscles (pectoralis superficialis and gastrocnemius) and mitochondrial substrate oxidation enzyme activities in dissected tissues of 1- and 4-d-old chicks were studied. Results revealed that 1-day-old neonatal chicks were particularly vulnerable to cold exposure and were hypothermic. However, 4-d-old cold-exposed chicks maintained thermostability with significantly higher plasma corticosterone levels, oxygen consumption, heat production, and increased mitochondrial substrate oxidation enzyme activities (CS and 3HADH) in different dissected tissues. Analysis of gene transcripts for avian peroxisome-proliferator-activated receptor-γ co-activator-1α (avPGC1α) and avian uncoupling protein (avUCP) in skeletal muscles revealed no significant change between cold-sensitive (1-d-old) and cold-tolerant (4-d-old) neonatal chicks, and failed to explain the enhanced thermogenesis and tolerance to acute cold. Additionally, avPGC1α gene transcripts were not correlated with the increased enzyme activities of CS or 3HADH in skeletal muscle. In conclusion, these data suggest the possible role of HPA-axis in cold-tolerant neonatal chicks to modulate substrate mobilization and oxidation. The thermogenic mechanisms based in part upon the increased capacity for mitochondrial substrate oxidation in different tissues are associated with enhanced heat production to attain homeothermy and acquire tolerance to acute cold exposure during an early stage of neonatal chicks. © 2010 Elsevier Inc. All rights reserved. Source

Ogundari K.,Kyushu University | Abdulai A.,University of Kiel
Food Policy | Year: 2013

Several studies conducted over the past three decades on calorie-income relationship appear to give inconclusive results. This paper reviews these studies and employs meta-regression analysis to examine the potential publication bias in the calorie-income elasticity, as well as the impact of specific study attributes on the elasticities that have been reported in the empirical literature. A total of 40 empirical studies, which yielded 99 estimated elasticities were considered. The results indicate the presence of publication bias in the reported elasticities. Besides, the estimates revealed evidence of positive and significant empirical effect of income on calorie intake from all the studies that goes beyond publication bias. Study attributes such as ranking of the journal, panel data used in the analysis, whether expenditure was used as proxy for income, year of primary survey, sample size, and numbers of the years of primary data were found to have statistically significant impacts on the reported calorie-income elasticities in the literature. © 2013 Elsevier Ltd. Source

Kasama K.,Kyushu University | Whittle A.J.,Massachusetts Institute of Technology
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2011

This paper describes a probabilistic study of the two-dimensional bearing capacity of a vertically loaded strip footing on spatially random, cohesive soil using numerical limit analyses (NLA-CD). The analyses use a Cholesky decomposition (CD) technique with midpoint discretization to represent the spatial variation in undrained shear strength within finite-element meshes for both upper- and lower-bound analyses and assumes an isotropic correlation length. Monte Carlo simulations are then used to interpret the bearing capacity for selected ranges of the coefficient of variation in undrained shear strength and the ratio of correlation length to footing width. The results are compared directly with data from a very similar study in which bearing capacity realizations were computed using a method of local average subdivision (LAS) in a conventional displacement-based finite-element method (FEM-LAS). These comparisons show the same qualitative features but suggest that the published FEM calculations tend to overestimate the probability of failure at large correlation lengths. The NLA method offers a more convenient and computationally efficient approach for evaluating effects of variability in soil strength properties in geotechnical stability calculations. © 2011 American Society of Civil Engineers. Source

Aguilar-Arnal L.,University of California at Irvine | Katada S.,University of California at Irvine | Katada S.,Kyushu University | Orozco-Solis R.,University of California at Irvine | Sassone-Corsi P.,University of California at Irvine
Nature Structural and Molecular Biology | Year: 2015

The circadian clock controls the transcription of hundreds of genes through specific chromatin-remodeling events. The histone methyltransferase mixed-lineage leukemia 1 (MLL1) coordinates recruitment of CLOCK-BMAL1 activator complexes to chromatin, an event associated with cyclic trimethylation of histone H3 Lys4 (H3K4) at circadian promoters. Remarkably, in mouse liver circadian H3K4 trimethylation is modulated by SIRT1, an NAD+-dependent deacetylase involved in clock control. We show that mammalian MLL1 is acetylated at two conserved residues, K1130 and K1133. Notably, MLL1 acetylation is cyclic, controlled by the clock and by SIRT1, and it affects the methyltransferase activity of MLL1. Moreover, H3K4 methylation at clock-controlled-gene promoters is influenced by pharmacological or genetic inactivation of SIRT1. Finally, levels of MLL1 acetylation and H3K4 trimethylation at circadian gene promoters depend on NAD+ circadian levels. These findings reveal a previously unappreciated regulatory pathway between energy metabolism and histone methylation. © 2015 Nature America, Inc. All rights reserved. Source

Cholestatic hepatitis is a life-threatening recurrent pattern of hepatitis C virus (HCV) in immunosuppressed patients, for which curative treatment has not yet been established. We report the successful treatment of cholestatic hepatitis in a 59-year-old man who had undergone right lobe living donor liver transplantation (LDLT) for liver cirrhosis (LC) caused by HCV. Following uneventful surgery and an uncomplicated posttransplant clinical course, there was an abrupt increase in total bilirubin in comparison to aminotransferase on postoperative day (POD) 60 (total bilirubin 16.2 mg/dl, alanine aminotransferase 100 U/l, HCV-RNA 390 kIU/ml). The histological findings of the liver tissue showed lymphocyte infiltration in the periportal zone and severe cholestasis. Considering the clinical course, cholestatic hepatitis was strongly suspected and pegylated interferon and ribavirin therapy was started immediately, resulting in not only a viral response, but minimal progression of fibrosis. This case serves to demonstrate that early diagnosis and timely initiation of optimal antiviral therapy is essential for the resolution of cholestatic hepatitis C. Source

Takarabe M.,Kyoto University | Kotera M.,Kyoto University | Nishimura Y.,Kyoto University | Goto S.,Kyoto University | Yamanishi Y.,Kyushu University
Bioinformatics | Year: 2012

Motivation: Unexpected drug activities derived from off-targets are usually undesired and harmful; however, they can occasionally be beneficial for different therapeutic indications. There are many uncharacterized drugs whose target proteins (including the primary target and off-targets) remain unknown. The identification of all potential drug targets has become an important issue in drug repositioning to reuse known drugs for new therapeutic indications. Results: We defined pharmacological similarity for all possible drugs using the US Food and Drug Administration's (FDA's) adverse event reporting system (AERS) and developed a new method to predict unknown drug-target interactions on a large scale from the integration of pharmacological similarity of drugs and genomic sequence similarity of target proteins in the framework of a pharmacogenomic approach. The proposed method was applicable to a large number of drugs and it was useful especially for predicting unknown drug-target interactions that could not be expected from drug chemical structures. We made a comprehensive prediction for potential off-targets of 1874 drugs with known targets and potential target profiles of 2519 drugs without known targets, which suggests many potential drug-target interactions that were not predicted by previous chemogenomic or pharmacogenomic approaches. © The Author(s) 2012. Published by Oxford University Press. Source

Ookouchi Y.,Kyushu University
Journal of High Energy Physics | Year: 2014

We investigate cosmological constraints on phenomenological models with discrete gauge symmetries by discussing the radiation of standard model particles from Aharonov-Bohm strings. Using intersecting D-brane models in Type IIA string theory, we demonstrate that Aharonov-Bohm radiation, when combined with cosmological observations, imposes constraints on the compactification scales. © 2014 SISSA. Source

Imaizumi K.,Kyushu University
Bioscience, Biotechnology and Biochemistry | Year: 2011

Atherosclerosis is a multifactorial, long-lasting process in humans. Accordingly, animal models in which more rapid changes occur can be useful for the study of this process. Among such models are apolipoprotein E-deficient (apoE-/-) mice, which give insight into the human process. ApoE-/- mice show impaired clearing of plasma lipoproteins and develop atherosclerosis in a short time, and hence they are an excellent model in which to assess the impact of dietary factors. This review considers lipid metabolism and inflammation as well as nutritional constituents affecting atherosclerosis, with reference to apoE-/- mice, and discusses the mechanisms through which they act. Source

Kobayashi M.,Japan Science and Technology Agency | Takahara A.,Japan Science and Technology Agency | Takahara A.,Kyushu University
Chemical Record | Year: 2010

This article demonstrates a water-lubrication system using high-density hydrophilic polymer brushes consisting of 2,3-dehydroxypropyl methacrylate (DHMA), vinyl alcohol, oligo(ethylene glycol)methyl ether methacrylate, 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTAC), 3-sulfopropyl methacrylate potassium salt (SPMK), and 2-methacryloyloxyethyl phosphorylcholine (MPC) prepared by surface-initiated controlled radical polymerization. Macroscopic frictional properties of brush surfaces were characterized by sliding a glass ball probe in water using a ball-on-plate type tribotester under the load of 0.1-0.49 N at the sliding velocity of 10-5-10-1 m s-1 at 298 K. A poly(DHMA) brush showed a relatively larger friction coefcient in water, whereas the polyelectrolyte brushes, such as poly(SPMK) and poly(MPC), revealed significantly low friction coefficients below 0.02 in water and in humid air conditions. A drastic reduction in the friction coefficient of polyelectrolyte brushes in aqueous solution was observed at around 10-3-10-2 m s-1 owing to the hydrodynamic lubrication effect, however, an increase in salt concentration in the aqueous solution led to the increase in the friction coefficients of poly(MTAC) and poly(SPMK) brushes. The poly(SPMK) brush showed a stable and low friction coefficient in water even after sliding over 450 friction cycles, indicating a good wear resistance of the brush film. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Source

Katsuki T.,Kyushu University
Journal of the American Chemical Society | Year: 2010

Ru(NO)-salen complexes were found to catalyze asymmetric aerobic oxygen atom transfer reactions such as sulfide oxidation and epoxidation in the presence of water under visible light irradiation at room temperature. Oxidation of sulfides including alkyl aryl sulfides and 2-substituted 1,3-dithianes using complex 2 as the catalyst proceeded with moderate to high enantioselectivity of up to 98% ee, and epoxidation of conjugated olefins using complex 3 as the catalyst proceeded with good to high enantioselectivity of 76-92% ee. Unlike biological oxygen atom transfer reactions that need a proton and electron transfer system, this aerobic oxygen atom transfer reaction requires neither such a system nor a sacrificial reductant. Although the mechanism of this oxidation has not been completely clarified, some experimental results support the notion that an aqua ligand coordinated with the ruthenium ion serves as a proton transfer agent for the oxygen activation process, and it is recycled and used as the proton transfer mediator during the process. Thus, we have achieved catalytic asymmetric oxygen atom transfer reaction using molecular oxygen that can be carried out under ambient conditions. © 2010 American Chemical Society. Source

Iramina K.,Kyushu University
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference | Year: 2011

We developed a simple, portable and easy system to the motion of pronation and supination of the forearm. This motion was measured by wireless acceleration and angular velocity sensor. The aim of this system is evaluation of minor nervous dysfunction. It is for the screening of the developmental disorder child. In this study, in order to confirm the effectiveness of this system, the reference curve of the neuromotor development was experimentally obtained. We studied 212 participants (108 males, 104 females) aged 7 to 12 years attending the kindergarten school. We could obtain the reference curve of the neuromotor development using this system. We also investigated the difference of neuromotor function between normally developed children and a ADHD child. There is a possibility that abnormality of the minor nervous dysfunction can be detected by using this system. Source

Fenwick M.,Kyushu University
Theoretical Criminology | Year: 2013

This article examines whether the concept of penal populism can be useful in understanding contemporary developments in Japanese criminal justice. In addressing this issue it is suggested that we need to draw a clear distinction between different conceptions of penal populism and, in particular, we should avoid equating penal populism with intensification of the severity of state punishment. A discussion of the Japanese experience highlights the importance of focusing on populism as a process by which new voices emerge and influence criminal justice policy as a result of an unmet demand for justice and security. This perception of a lack of security and justice is a global phenomenon that, nevertheless, expresses itself in distinctive, culturally specific ways. Although the extent of this shift should not be exaggerated, at least in a Japanese context, penal populism has contributed to an opening up of criminal justice and a disaggregation of state sovereignty. © The Author(s) 2013. Source

Doi T.,Kyushu University
Fukuoka igaku zasshi = Hukuoka acta medica | Year: 2011

Adolescent Idiopathic Scoliosis tends to be complicated with spine and ribcage deformities. In addition to the coronal curvature, among the features of right thoracic scoliosis, flat chest, ribcage rotation, cardiac compression and an aortic left shift are also observed. Aorta is known to shift in a leftward direction, especially at the mid-thoracic level. The cause of aortic left shift in scoliosis is not known. To clarify the features of a scoliosis deformity, especially the relationship of the aortic left shift and the flat chest in scoliosis, we investigated the CT scan images of scoliosis patients. For the measurement of scoliosis patients, the pre-operative CT scans of 22 patients with non-congenital right thoracic scoliosis were recruited. For controls, 25 age-matched non-scoliosis patients were recruited. The aortic location, the ribcage rotation angle and chest depth were measured by CT scan. The chest depth was defined as the smallest inner chest cavity depth between the anterior vertebral body and the anterior inner chest wall. Chest depth in scoliosis patients was found to be significantly narrower than the control group at every thoracic level, from T6 to T11. The aortic left shift was significantly larger in scoliosis patients at all measured levels. The chest depth correlated with an aortic leftward shift (r = 0.49). The aortic location was found to be correlated with the ribcage rotation angle (r = -0.52), and the ribcage rotation angle correlated with the thoracic side curvature (r = 0.61) In right thoracic scoliosis, an aortic left shift correlated with both flat chest and the ribcage rotation. Source

Takahashi T.,Kyushu University
Bulletin of the American Meteorological Society | Year: 2010

Tsutomu Takahashi focuses on the videosonde system and its use in the study of East Asian monsoon rain. An infrared light is mounted just above the camera lens. Interruption of this beam by any particle larger than 0.5 mm in diameter triggers a flash lamp mounted above the camera's lens. The image signals are transmitted to the ground on a 1680-MHz carrier wave frequency modulated between 10 Hz and 1 MHz. The images are projected on a television screen and recorded on video tape. A variety of rain systems were sampled that are considered representative of monsoon cloud systems for their sites. Typical rain systems were recognized at each site. Upper divergence over the plateau of inland China helped to develop large cumulonimbus clouds over the mountainous terrain, producing frequent lightning and heavy rain. The videosonde data showed that both graupel and ice crystals are highly charged and their space charge is comparable to values obtained in thunderstorms. Source

Tanaka M.,Kyushu University
Nature Reviews Gastroenterology and Hepatology | Year: 2011

Although considerable progress has been made in our understanding of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, some issues still remain to be resolved. Uncertainty exists regarding the classification of IPMNs. The necessity of the mixed-type category of IPMN and whether such lesions should be defined radiographically or histologically needs to be determined. The preoperative distinction of branch duct IPMNs from nonmucinous cysts should be further investigated so that potentially malignant lesions can be identified and management strategies guided effectively. The role and safety of cystic fluid analysis remains to be clarified in this context. With regard to the diagnosis of malignancy in branch duct IPMNs, criteria for identifying malignancy need to be re-evaluated. The presence of mural nodules is a very reliable predictor; however, controversy exists over the value of size as a reliable indicator. Criteria with increased specificity are needed, perhaps including histological subtype of lesion, to reduce the false-positive rate of the present criteria. Finally, the best modality and interval for surveillance of branch duct IPMNs requires determination because of its significance in terms of malignant transformation, development of distinct ductal adenocarcinoma and disease recurrence after resection. © 2011 Macmillan Publishers Limited. All rights reserved. Source

Background:Although testosterone suppression during androgen-deprivation therapy (ADT) and obesity have been reported to affect ADT efficacy, there are few comprehensive analyses on the impact on ADT outcome. Recently, we demonstrated that the SRD5A2 polymorphism was associated with metastatic prostate cancer prognosis. Therefore, in this study, we investigated the relationship between ADT serum testosterone levels or body mass index (BMI) and the prognosis among men treated with primary ADT for metastatic prostate cancer. In addition, we examined the association of serum testosterone levels during ADT with the SRD5A2 polymorphism.Methods:This study included 96 Japanese patients with metastatic prostate cancer. The relationship between clinicopathological parameters, including serum testosterone levels during ADT and BMI, and progression-free survival, overall survival and survival from progression following primary ADT treatment for metastatic prostate cancer was examined. Additionally, the association between the SRD5A2 gene polymorphism (rs523349) and serum testosterone levels during ADT was examined in 86 cases.Results:Among clinicopathological parameters, the lowest quartile of serum testosterone levels during ADT was a significant predictor of better overall survival as well as survival from castration resistance. However, BMI was not associated with prognosis. The CC allele in the SRD5A2 gene (rs523349), encoding the less active 5α-reductase, was associated with lower serum testosterone levels during ADT.Conclusions:Taken together, these findings revealed a dramatic suppression of serum testosterone by ADT was associated with better survival among men with metastatic prostate cancer that have undergone primary ADT, which may be affected by the SRD5A2 gene polymorphism.Prostate Cancer and Prostatic Diseases advance online publication, 9 February 2016; doi:10.1038/pcan.2016.2. © 2016 Macmillan Publishers Limited Source

Sagara K.,Kyushu University
Few-Body Systems | Year: 2010

Experiments on pd scattering, pd capture and pd breakup performed by our Kyushu University group since 1988 are reviewed. Various discrepancies between the experimental results and 3N Faddeev calculations have been found, and systematical measurements of the discrepancies have been made. From discrepancies in pd scattering cross section and in 3N binding energy, 2π-exchange 3N force was determined, and the discrepancies were satisfactorily diminished. There are, however, still many discrepancies awaiting theoretical investigation, as described in this report. © 2010 The Author(s). Source

Matsumoto T.,Hokkaido University | Kato K.,Hokkaido University | Yahiro M.,Kyushu University
Physical Review C - Nuclear Physics | Year: 2010

We present a novel method of smoothing discrete breakup cross sections calculated by the method of continuum-discretized coupled channels. The smoothing method based on the complex scaling method is tested with success for a Ni58(d,pn) reaction at 80 MeV as an example of three-body breakup reactions and applied to a 12C(6He,nn4He) reaction at 229.8 MeV as an example of four-body breakup reactions. Fast convergence of the breakup cross section with respect to extending the model space is confirmed. The method is also applied to 12C(6He,nn4He) and 208Pb(6He,nn4He) reactions at 240 MeV/A and compared with the experimental data. © 2010 The American Physical Society. Source

Chloroplasts in land plants have a small genome consisting of only 100 genes encoding partial sets of proteins for photosynthesis, transcription and translation. Although it has been thought that chloroplast transcription is mediated by a basically cyanobacterium-derived system, due to the endosymbiotic origin of plastids, recent studies suggest the existence of a hybrid transcription machinery containing non-bacterial proteins that have been newly acquired during plant evolution. Here, we highlight chloroplast-specific non-bacterial transcription mechanisms by which land plant chloroplasts have gained novel functions. Source

Nishida M.,Kyushu University
Journal of Pharmacological Sciences | Year: 2011

Heart failure is a major cause of death in developed countries, and the development of an epoch-making cure is desired from the viewpoint for improving the quality of life and reducing the medical cost of the patient. The importance of neurohumoral factors, such as angiotensin (Ang) II and catecholamine, for the progression of heart failure has been supported by a variety of evidence. These agonists stimulate seven transmembrane-spanning receptors that are coupled to heterotrimeric GTP-binding proteins (G proteins). Using specific pharmacological tools to assess the involvement of G protein signaling pathways, we have revealed that á subunit of G q (Gα q) activates Ca 2+-dependent hypertrophic signaling through diacylglycerol-activated transient receptor potential canonical (TRPC) channels (TRPC3 and TRPC6: TRPC3/6). In contrast, activation of Gα 12 family proteins in cardiomyocytes confers pressure overload-induced cardiac fibrosis via stimulation of purinergic P2Y 6 receptors induced by extracellular nucleotides released from cardiomyocytes. In fact, direct or indirect inhibition of TRPC3/6 or P2Y 6 receptors attenuates pressure overload-induced cardiac dysfunction. These findings will provide a new insight into the molecular mechanisms underlying pathogenesis of heart failure. © The Japanese Pharmacological Society. Source

Sakaguchi H.,Kyushu University
Journal of the Physical Society of Japan | Year: 2013

Shock waves propagate in falling coupled harmonic oscillators. The bottom end of coupled harmonic oscillators does not fall downwards until a shock wave reaches the bottom end. The exact solution can be expressed by the Fourier series expansion, and an approximate solution can be expressed by the integral of the Airy function. The width of the shock wave increases slowly in accordance with a power law. © 2013 The Physical Society of Japan. Source

Arakawa K.,Kyushu University
Wear | Year: 2015

The effects of the contact area and degree of wear on the sliding friction of polytetrafluoroethylene (PTFE) samples were investigated using an inclined glass plane. The sliding velocity and contact area of the samples were evaluated as functions of the sliding length and angle of inclination. The sliding velocity decreased exponentially as the contact area increased due to the wear of the samples, suggesting that wear is significant in non-lubricated sliding friction with PTFE on glass. The sliding velocity increased toward a maximum during the early stages of sliding, and then decreased in the later stages. The increase in the velocity during the early stages of the experiment can be explained by acceleration due to gravity, and the subsequent decrease is attributed to an increase in the contact area and to the build-up of debris particles due to wear caused by frictional heating of the contact area of the sample. © 2015 Elsevier B.V. Source

Goldstein S.,Rutgers University | Hara T.,Kyushu University | Tasaki H.,Gakushuin University
Physical Review Letters | Year: 2013

We prove two theorems concerning the time evolution in general isolated quantum systems. The theorems are relevant to the issue of the time scale in the approach to equilibrium. The first theorem shows that there can be pathological situations in which the relaxation takes an extraordinarily long time, while the second theorem shows that one can always choose an equilibrium subspace, the relaxation to which requires only a short time for any initial state. © 2013 American Physical Society. Source

Yoshimatsu K.,University of California at Irvine | Lesel B.K.,University of California at Irvine | Yonamine Y.,University of California at Irvine | Beierle J.M.,University of California at Irvine | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2012

Catch me if you can: Multifunctional, polymer-based nanoparticles that are capable of temperature-responsive "catch-and-release" of a target protein have been synthesized. The process is reversible and does not denature the proteins. An optimized combination of functional monomers imparts binding selectivity toward a target protein over other proteins. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Xu J.,Nanjing University of Aeronautics and Astronautics | Kawashima S.,Kyushu University
Archive for Rational Mechanics and Analysis | Year: 2014

The basic existence theory of Kato and Majda enables us to obtain local-in-time classical solutions to generally quasilinear hyperbolic systems in the framework of Sobolev spaces (in x) with higher regularity. However, it remains a challenging open problem whether classical solutions still preserve well-posedness in the case of critical regularity. This paper is concerned with partially dissipative hyperbolic system of balance laws. Under the entropy dissipative assumption, we establish the local well-posedness and blow-up criterion of classical solutions in the framework of Besov spaces with critical regularity with the aid of the standard iteration argument and Friedrichs' regularization method. Then we explore the theory of function spaces and develop an elementary fact that indicates the relation between homogeneous and inhomogeneous Chemin-Lerner spaces (mixed space-time Besov spaces). This fact allows us to capture the dissipation rates generated from the partial dissipative source term and further obtain the global well-posedness and stability by assuming at all times the Shizuta-Kawashima algebraic condition. As a direct application, the corresponding well-posedness and stability of classical solutions to the compressible Euler equations with damping are also obtained. © 2013 Springer-Verlag Berlin Heidelberg. Source

Arnqvist G.,Uppsala University | Tuda M.,Kyushu University
Proceedings of the Royal Society B: Biological Sciences | Year: 2010

Although males and females share much of the same genome, selection is often distinct in the two sexes. Sexually antagonistic loci will in theory cause a gender load in populations, because sex-specific selection on a given trait in one sex will compromise the adaptive evolution of the same trait in the other sex. However, it is currently not clear whether such intralocus sexual conflict (ISC) represents a transient evolutionary state, where conflict is rapidly resolved by the evolution of sexual dimorphism (SD), or whether it is a more chronic impediment to adaptation. All else being equal, ISC should manifest itself as correlated evolution between population fitness and SD in traits expressed in both sexes. However, comparative tests of this prediction are problematic and have been unfeasible. Here, we assess the effects of ISC by comparing fitness and SD across distinct laboratory populations of seed beetles that should be well adapted to a shared environment. We show that SD in juvenile development time, a key life-history trait with a history of sexually antagonistic selection in this model system, is positively related to fitness. This effect is due to a correlated evolution between population fitness and development time that is positive in females but negative in males. Loosening the genetic bind between the sexes has evidently allowed the sexes to approach their distinct adaptive peaks. © 2009 The Royal Society. Source

Takeda M.,Kinki University | Okamoto I.,Kyushu University | Nakagawa K.,Kinki University
Lung Cancer | Year: 2015

Three epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) - afatinib, erlotinib, and gefitinib - are available for the treatment of patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). Given the long-term exposure of such patients to EGFR-TKIs, the toxicological properties of these agents in these individuals may differ from those observed in unselected patients. We compared the frequencies of severe adverse events (AEs) among EGFR mutation-positive NSCLC patients treated with these three EGFR-TKIs. Materials and methods: We performed a pooled analysis of severe AEs according to the type of EGFR-TKI administered with the use of data extracted from prospective clinical trials that evaluated the clinical efficacy of gefitinib, erlotinib, or afatinib in NSCLC patients with EGFR mutations. Results: Twenty-one trials published between 2006 and 2014 and including 1468 patients were eligible for analysis. Patients in 13 trials (. n=. 457) received gefitinib, those in 5 trials (. n=. 513) received erlotinib, and those in 3 trials (. n=. 498) received afatinib. Rash and diarrhea of grade ≥3 were significantly more frequent with afatinib therapy than with erlotinib or gefitinib therapy. The frequency of interstitial lung disease (ILD) of grade ≥3 was low (0.6-2.2%) with all three EGFR-TKIs and did not differ significantly among them. Gefitinib was associated with a significantly higher frequency of hepatotoxicity of grade ≥3 compared with erlotinib or afatinib. The overall frequency of AEs leading to treatment withdrawal was 6.1% (83 of 1354 evaluable patients), with such AEs occurring significantly more often with afatinib or gefitinib than with erlotinib. The most common withdrawal AEs were skin toxicity, ILD, and hepatotoxicity. Conclusion: Such information on AEs should facilitate selection of the most appropriate EGFR-TKI for EGFR mutation-positive NSCLC patients with regard to mitigation of the risk for certain types of toxicity. © 2015 Elsevier Ireland Ltd. Source

Kira J.-I.,Kyushu University
Pathophysiology | Year: 2011

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) while neuromyelitis optica (NMO) is an inflammatory disease of the CNS that selectively affects the optic nerves and spinal cord. In Asians, MS is rare; however, when it appears, the selective and severe involvement of the optic nerves and spinal cord is characteristic. This form, termed opticospinal MS (OSMS), has similar features to the relapsing form of NMO in Western populations. Recently, a specific IgG against NMO, designated NMO-IgG, was discovered, and the relevant antigen was found to be aquaporin-4 (AQP4), one of the major water channel proteins in the CNS. Because NMO-IgG has been reported to be present in 30-60% of OSMS patients, OSMS in Asians has been suggested to be the same entity as NMO. The sensitivity of NMO-IgG/anti-AQP4 antibody for NMO varies from 30% to 80%, while the specificity is 90-100%. Pathological studies on NMO have revealed perivascular immune complex (IgM, IgG and C9neo) deposition and extensive loss of AQP4 in active lesions, where myelin basic protein (MBP) staining was relatively preserved. IgG from NMO-IgG-seropositive NMO patients induces astrocyte death in culture in the presence of complements, and reproduces astrocyte loss in vivo when MBP-specific T cells are co-transferred to cause experimental autoimmune encephalomyelitis. It is thus postulated that the complement-activating anti-AQP4 antibody plays a pivotal role in the development of NMO lesions through astrocyte necrosis, and that demyelination is a secondary event.However, in autopsied cases of NMO, we and others found that some demonstrated selective AQP4 loss while others showed preservation of AQP4, even in the acute lesions. We also found that, in some MS lesions, AQP4 was lost extensively far beyond the areas of myelin loss. In the CSF, proinflammatory cytokines such as IL-17, IL-8, IFNγ, and G-CSF are markedly elevated in OSMS patients, irrespective of the presence or absence of anti-AQP4 antibody. In OSMS and NMO patients, T cells reactive to myelin proteins show intra- and inter-molecular epitope spreading, suggesting that T cells are already stimulated with myelin antigens in vivo. These findings suggest that mechanism of NMO and OSMS in Asians is heterogeneous, anti-AQP4 antibody-related and -unrelated, and that not only anti-AQP4 antibody but also myelin-autoreactive Th17 or Th1 cells may also play a role in triggering CNS inflammation. Possible mechanisms for NMO and OSMS are discussed in this review. © 2010 Elsevier Ireland Ltd. Source

Matsushita T.,Kyushu University
The journal of obstetrics and gynaecology research | Year: 2011

A 39-year-old Japanese woman was referred to our hospital for severe abdominal pain at 22 weeks and 2 days of gestation. Abdominal computed tomography (CT) suggested perforation of the gastrointestinal tract and emergency surgery was conducted. There was a fibrous adhesion between an enlarged uterus and the sigmoid colon. There was a 5.0-cm perforation near the adhesion in the posterior wall of the sigmoid colon. We performed a partial resection of the sigmoid colon and Hartmann's procedure with copious intraperitoneal lavage. Five hours following the laparotomy, uterine contractions could not be controlled and the patient delivered vaginally. The neonate died almost immediately after delivery. We conclude that although stercoral bowel perforation is rare, poor prognosis after perforation emphasizes the need to carry out a CT scan for patients who present with undiagnosed severe abdominal pain and compatible medical history, even if the patient is pregnant. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology. Source

The genus Rhynchospora in the Cyperaceae includes both C3 and C4 species. The C4 species shows two distinct Kranz anatomies: the rhynchosporoid and the fimbristyloid-chlorocyperoid intermediate. This study reports the use of herbarium specimens to obtain the leaf ultrastructure in eight Rhynchospora C4 species in relation to their C4 biochemical subtypes, together with carbon isotope ratios. Despite the use of dried materials, electron microscopic observation revealed the structures of chloroplasts and cell walls. In C4 species with the fimbristyloid-chlorocyperoid intermediate anatomy, Kranz cell chloroplasts had reduced grana and convoluted thylakoids, and suberized lamellae occurred in the mestome sheath cell walls. In C4 species with the rhynchosporoid anatomy, the Kranz cell chloroplasts also had reduced grana and convoluted thylakoids but with less convolution; suberized lamellae occurred in the Kranz cell walls. These data show that the Rhynchospora C4 species have ultrastructural features present in the NADP-malic enzyme-type C4 sedges. The Kranz species had δ13C values typical of C4 plants, as expected, and the values did not differ significantly between the two Kranz anatomies. This study demonstrates that dried herbarium specimens can be used for ultrastructural observation of C4 leaves and provide valuable information for understanding of the photosynthetic diversity. © 2013 by The University of Chicago. All rights reserved. Source

Kiyohara C.,Kyushu University | Yoshimasu K.,Wakayama Medical University
Psychiatric Genetics | Year: 2010

Objectives A functional polymorphism in the promoter region of the 5-hydroxytryptamine (serotonin) transporter (5-HTT) gene, termed 5-HTTLPR, alters transcription of the 5-HTT gene. The short variation (S allele) produces less transcriptional efficiency of serotonin, which can partly account for psychiatric disorders. Despite strong biological plausibility, the relationship between 5-HTTLPR and the risk of major depressive disorder (MDD) is unclear. To elucidate the relationship, we applied meta-analysis techniques to molecular studies of 5-HTTLPR and MDD. Methods A total of 22 articles were identified from MEDLINE through March 2008, using the search keywords 'depression,' '5-HTTLPR', and 'polymorphism.' The authors assessed the evidence of genotypic association using STATA Version 8.2. Results Summary frequencies of the S allele of 5-HTTLPR among Caucasians and Asians based on the random effects model were 42.1% [95% confidence interval (CI) = 40.5-43.6] and 76.8% (95% CI= 73.9-79.7), respectively. The distribution of the S allele was significantly different between Asians and Caucasians (P < 0.001). The SS genotype was significantly associated with an increased risk of MDD among Caucasian populations (odds ratio = 1.41, 95% CI= 1.15-1.72), although there was no significant association among Asians. Conclusion Although the summary risk for developing MDD in individuals with the 'at-risk' SS genotype of 5-HTTLPR may be small, MDD is such a common disease that even a small increase in risk translates to a large number of excess MDD cases in the population. Thus, 5-HTT may be a candidate MDD susceptibility gene. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source

In this study, we investigated the effects of duration of stay in a temperate area on the thermoregulatory responses to passive heat exposure of residents from tropical areas, particularly to clarify whether they would lose their heat tolerance during passive heat exposure through residence in a temperate country, Japan. We enrolled 12 males (mean ± SE age 25.7 ± 1.3 years) from south-east Asian countries who had resided in Japan for a mean of 24.5 ± 5.04 months, and 12 Japanese males (age 24.1 ± 0.9 years). Passive heat exposure was induced through leg immersion in hot water (42°C) for 60 minutes under conditions of 28°C air temperature and 50% relative humidity. Compared with the Japanese group, the tropical group displayed a higher pre-exposure rectal temperature (P < 0.01) and a smaller increase in rectal temperature during 60 minutes of leg immersion (P = 0.03). Additionally, the tropical group showed a tendency towards a lower total sweat rate (P = 0.06) and lower local sweat rate on the forehead (P = 0.07). The tropical group also had a significantly longer sweating onset time on the upper back (P = 0.04) compared with the Japanese groups. The tropical group who stayed in Japan for > 23 months sweated earlier on the forehead and upper back than those who stayed in Japan < 11 months (P < 0.01 and P = 0.03 for the forehead and upper back, respectively). There was a positive correlation between duration of stay in Japan and total sweat rate (r = 0.58, P <0.05), and negative correlations between duration of stay and sweating onset time on the forehead (r = -0.73, P = 0.01) and on the upper back (r = -0.66, P = 0.02). Other physiological indices measured in this study did not show any difference between the subjects in the tropical group who had lived in Japan for a shorter time and those who had lived there for a longer time. We conclude that the nature of heat acclimatization of the sweating responses to passive heat exposure that are acquired from long-term heat acclimatization is decayed by a stay in a temperate area, as shown by the subjects in our tropical group. We did not find any evidence of a decay in the other physiological indices, indicating that heat tolerance acquired from long-term heat acclimatization is not completely diminished through residence in a temperate area for less than 4 years, although some aspects of this heat tolerance may be decayed. Source

Inaba K.,Kyushu University
Genes to Cells | Year: 2010

The formation of protein disulfide bonds is an oxidative reaction that is crucial for the folding and maturation of many secreted and membrane proteins. Both prokaryotic and eukaryotic cells possess various disulfide oxidoreductases and redox-active cofactors to accelerate this oxidative reaction in a correct manner. Crystal or solution structures have been solved for some of the oxidoreductases in the past 10 years, leading to remarkable progress in the field of thiol-based redox cell biology. Consequently, structural and mechanistic similarities in the disulfide bond formation pathways have been uncovered. This review highlights the molecular basis of the elaborate oxidative systems operating in the Escherichia coli periplasm, the endoplasmic reticulum lumen and the mitochondrial intermembrane space. The accumulated knowledge provides important insights into how protein and redox homeostasis are maintained in the cell. © 2010 The Author. Journal compilation © 2010 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd. Source

To evaluate the effects of the regional pollutant emission and long-range transport from East Asia of nitrogen and sulfur pollutants on air quality at an inland suburban-forested site in northern Kyushu, western Japan, nitrogen and sulfur pollutants were characterized from May 2006 to April 2007 using an annular denuder system. The annual mean concentration of HNO3 (2.16μgm-3) at the study site was comparable to concentrations reported in urban areas. The HNO3 concentration had a diurnal variation, being higher in daytime and lower at night. The diurnal variation of wind direction suggests air pollutants emitted from the regional urban area were transported to the study site during the daytime and caused a higher HNO3 concentration. The HNO3 concentration was significantly higher in summer and spring than in winter. The annual mean concentrations of SO2 and nss-SO4 2- (6.52 and 7.70μgm-3, respectively) were higher than concentrations determined in other urban areas and forested areas near urban areas in Japan and other countries. The SO2 concentration was significantly higher in winter and spring than in summer. Backward trajectory analysis indicates the long-range transport from East Asia partly contributed to the higher concentrations of SO2 in winter and spring. In contrast, there were no statistical differences in the nss-SO4 2- concentrations among seasons, which could be explained by increased oxidation of SO2 to SO4 2- in summer. The value of sulfur conversion ratio (Fs) being higher throughout the year at the study site (52.6%) than values determined in urban sites and there being no diurnal variation of Fs indicates the long-range transport of nss-SO4 2- not only from East Asia but also from other areas including Japan. The equivalent ratio of NH4 + and nss-SO4 2- at the study site (0.96±0.22) indicates that acidic sulfate is neutralized by NH3, existing mainly as (NH4)2SO4 in fine particles. On the other hand, NH4NO3 had scarcely formed at the study site, unlike the case for urban areas. Ca2+ and Na+ are suggested to be the counter ions of NO3 - in coarse particles, which is similar to the situation for the sites where the concentration of NH3 is insufficient for NH4NO3 to form. © 2010 Elsevier B.V. Source

Unlike other natural network systems, assortativity can be observed in most human social networks, although it has been reported that a social dilemma situation represented by the prisoner's dilemma favors dissortativity to enhance cooperation. We established a new coevolutionary model for both agents' strategy and network topology, where teaching and learning agents coexist. Remarkably, this model enables agents' enhancing cooperation more than a learners-only model on a time-frozen scale-free network and produces an underlying assortative network with a fair degree of power-law distribution. The model may imply how and why assortative networks are adaptive in human society. © 2013 Elsevier B.V. All rights reserved. Source

Yamaguchi R.,Kyushu University | Perkins G.,University of California at San Diego
Cancer Research | Year: 2012

Because each cancer is a heterogeneous mix of cancer cells at different stages of development, we are faced with trying to treat many different diseased cells all at once. An authentic approach is to build a genomic and proteomic profile of a patient, identify the target oncogenes, and prescribe the combination of targeted drugs tailored for that patient. However, there are many practical problems with this personalized medicine approach: (i) cancers often generate treatment-resistant phenotypes, (ii) the treatment could be enormously expensive, and (iii) most of the targeted drugs have not been developed yet. We propose a different approach: therapies that combine 2-deoxyglucose (2DG) with Bcl-2 antagonist such as ABT-263/737 (ABT). Proapoptotic protein Bak is normally sequestered by Mcl-1 and Bcl-xL. Only when Bak is released from both Mcl-1 and Bcl-xL can it induce apoptosis. 2DG can prime highly glycolytic cells by dissociating Bak-Mcl-1 complex. Some brain cells and most cancer cells are primed by 2DG. ABT can bind to Bcl-xL, dissociating Bak-Bcl-xL complex, freeing Bak and inducing apoptosis. Because ABT cannot cross blood-brain barrier, the only cells exposed to both agents are highly glycolytic cancer cells located outside the brain. Because ABT directly triggers apoptosis at the step very near the terminal point of apoptosis, 2DG-ABT combination therapies are applicable to many types of cancer at all stages of development, with little side effect. ©2011 AACR. Source

Ishino Y.,Kyushu University | Narumi I.,Toyo University
Current Opinion in Microbiology | Year: 2015

The genome of a living cell is continuously under attack by exogenous and endogenous genotoxins. Especially, life at high temperature inflicts additional stress on genomic DNA, and very high rates of potentially mutagenic DNA lesions, including deamination, depurination, and oxidation, are expected. However, the spontaneous mutation rates in hyperthermophiles are similar to that in Escherichia coli, and it is interesting to determine how the hyperthermophiles preserve their genomes under such grueling environmental conditions. In addition, organisms with extremely radioresistant phenotypes are targets for investigating special DNA repair mechanisms in extreme environments. Multiple DNA repair mechanisms have evolved in all organisms to ensure genomic stability, by preventing impediments that result in genome destabilizing lesions. © 2015 Elsevier Ltd. Source

Kira J.-I.,Kyushu University
Multiple Sclerosis Journal | Year: 2011

Baló's disease is characterized by alternating rings of demyelination and preserved myelin. As additional multiple sclerosis (MS)-like lesions often coexist in Baló's cases, Baló's disease is regarded as a variant of MS. In demyelinated areas, many hypertrophic astrocytes are present in close contact with oligodendrocytes, which often show apoptotic features. In the outermost layer of preserved myelin, stress proteins involved in tissue preconditioning are abundant in oligodendrocytes. The peri-plaque perimeter is thus assumed resistant to subsequent attack, thereby leaving a layer of preserved myelin. In some cases, Baló's concentric rings develop step by step in a centrifugal direction, whereas many other cases show simultaneous enhancement of multiple rings. Therefore tissue preconditioning and successive ring formation does not fully describe the mechanism of the disease. We recently reported that in four Filipino Baló's patients, aquaporin-4 (AQP4) was extensively lost in glial fibrillary acidic protein-positive hypertrophic astrocytes, both in demyelinated and myelinated layers of all actively demyelinating lesions. None of six further patients with MRI-confirmed Baló's disease were seropositive for anti-AQP4 antibody. I propose that AQP4 astrocytopathy, in the absence of anti-AQP4 antibody, is characteristic of Baló's disease. This hypothesis should be tested in future experimental studies. © The Author(s) 2011. Source

Tanabe T.,Kyushu University
Fusion Engineering and Design | Year: 2012

In order to establish a D-T fusion reactor as an energy source, economical conversion of fusion energy to electricity and/or heat, attaining enough margins in tritium breeding, and insuring tritium safety must be simultaneously achieved. Scientists and researchers working on Tritium in Japan are now tackling with T related problems. Their research subjects can be categorized into two, i.e. researches on "Science and technology" to establish safe and economic Tritium fuel cycle for fusion reactors and "Tritium safety". Many researchers from various universities, and institutes such as NIFS, JAEA and IEA (Inst. Environmental Science) in Japan are involved in various research programs. In this report, after brief introduction on Tritium related researches in Japan, important T issues to be solved for establishment of a fusion reactor will be summarized considering the handling of large amount of tritium, i.e. fuelling, D-T burning, T inventory, exhausting, refinement, confinement, permeation, leakage, contamination, regulation and tritium accountancy. © 2012 Elsevier B.V. All rights reserved. Source

Hironaka K.-I.,RIKEN | Hironaka K.-I.,Kyushu University | Morishita Y.,RIKEN
Current Opinion in Genetics and Development | Year: 2012

Patterning during organogenesis is fundamentally realized through the interpretation of morphogen gradients by particular types of gene regulatory networks (GRNs). However, as quantitative studies have reported, spatial profiles of morphogen gradients include intra-embryo and inter-embryo variability, which could lead to errors in spatial recognition by cells and variations in patterning. By mathematically modeling the processes of generation and readout of spatial information - information encoding and decoding, by an analogy to computer communication - and maximizing the reproducibility of patterning against noise, the general designs of gradient profiles and their interpretation have been clarified. Furthermore, over the past few years, basic studies on patterning in more dynamic situations, that is, patterning in growing tissues with time-variant gradients, have been initiated. Here we provide an overview of patterning studies, pattern generating GRNs, concepts of information coding design for robust patterning, and patterning in growing tissues. © 2012 Elsevier Ltd. Source

Ohdo S.,Kyushu University
Advanced Drug Delivery Reviews | Year: 2010

Mammalians circadian pacemaker resides in the paired suprachiasmatic nuclei (SCN) and influences a multitude of biological processes, including the sleep-wake rhythm. Clock genes are the genes that control the circadian rhythms in physiology and behavior. 24. h rhythm is demonstrated for the function of physiology and the pathophysiology of diseases. The effectiveness and toxicity of many drugs vary depending on dosing time. Such chronopharmacological phenomena are influenced by not only the pharmacodynamics but also pharmacokinetics of medications. The underlying mechanisms are associated with 24. h rhythms of biochemical, physiological and behavioral processes under the control of circadian clock. Thus, the knowledge of 24. h rhythm in the risk of disease plus evidence of 24. h rhythm dependencies of drug pharmacokinetics, effects, and safety constitutes the rationale for pharmacotherapy. Chronotherapy is especially relevant, when the risk and/or intensity of the symptoms of disease vary predictably over time as exemplified by allergic rhinitis, arthritis, asthma, myocardial infarction, congestive heart failure, stroke, and peptic ulcer disease. Morning once-daily administration of corticosteroid tablet medications results in little adrenocortical suppression, while the same daily dose split into four equal administrations to coincide with daily meals and bedtime results in significant hypothalamus-pituitary-adrenal (HPA) axis suppression. However, the drugs for several diseases are still given without regard to the time of day. Identification of a rhythmic marker for selecting dosing time will lead to improved progress and diffusion of chronopharmacotherapy. To monitor the rhythmic marker such as clock genes it may be useful to choose the most appropriate time of day for administration of drugs that may increase their therapeutic effects and/or reduce their side effects. Furthermore, to produce new rhythmicity by manipulating the conditions of living organs by using rhythmic administration of altered feeding schedules or several drugs appears to lead to the new concept of chronopharmacotherapy. Several drugs cause alterations in the 24. h rhythms of biochemical, physiological and behavioral processes. The alteration of rhythmicity is sometimes associated with therapeutic effects, or may lead to illness and altered homeostatic regulation. Attention should be paid to the alteration of biological clock and consider it an adverse effect, when it leads to altered regulation of the circadian system which is a serious problem affecting basic functioning of living organisms. One approach to increasing the efficiency of pharmacotherapy is administering drugs at times during which they are best tolerated. From viewpoints of pharmaceutics, the application of biological rhythm to pharmacotherapy may be accomplished by the appropriate timing of conventionally formulated tablets and capsules, and the special drug delivery system to synchronize drug concentrations to rhythms in disease activity. New technology for delivering medications precisely in a time-modulated fashion by bedside or ambulatory pumps is developing to manage human diseases. Therefore, we introduce an overview of the dosing time-dependent alterations in therapeutic outcome and safety of drug. The underlying mechanisms and usefulness are introduced from viewpoint of chronopharmacology and chronotherapy. © 2010. Source

Nishikawa M.,Kyushu University
Fusion Science and Technology | Year: 2010

The tritium balance in a D-T fusion reactor is discussed in this paper comparing the amount of tritium consumed in the fueling cycle including the plasma vessel with the amount of tritium generated in the blanket system, using information reported so far. This comparison shows that the overall burning efficiency of tritium in the plasma vessel, the tritium loss ratio represented by tritium trapping in the redeposition layer of the plasmafacing material, and the recovery efficiency in the tritium breeding system play important roles in the tritium balance and that it may not be easy to maintain good tritium economy of a D-T fusion reactor if the proper combination of burning efficiency, tritium loss ratio, and tritium recovery efficiency is not obtained. The allowable limits for the overall tritium burning efficiency, for the tritium loss ratio in the fueling cycle, and for the recovery efficiency to secure the self-sustainable tritium system are also discussed in this paper. Source

Suzuki A.,Kyushu University | Suzuki A.,Japan Science and Technology Agency
Current Opinion in Gastroenterology | Year: 2015

Purpose of review Recently, it has been suggested that hepatocytes can potentially convert their fate into that of cholangiocytes when the liver receives an injury. This review concisely summarizes these new findings, especially those obtained in studies using cell-lineage tracing methods. Recent findings Recent advances in technologies using mutant mice with a tamoxifen-inducible Cre/loxP system have allowed heritable labeling of a particular type of cell and enabled us to follow the fate of their progeny. This is generally known as 'genetic lineage-tracing', and has been applied in various studies that require tracking of the fate of cells in living mice. Previous studies using these methods have revealed that hepatocytes themselves can give rise to cholangiocytes through Notch-mediated cell-fate conversion from hepatocytes to cholangiocytes in injured liver tissue and at the onset of liver cancer. Summary Intensive studies using in-vivo genetic lineage-tracing approaches have provided new insights into the nature of cellular identity and plasticity in the liver, which will contribute to the development of new therapeutic strategies for liver diseases. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source

Inbreeding depression of an aspect of fitness is observed in many insects, but the traits that are of importance for inbreeding depression of fitness remain poorly understood. Here the magnitude of inbreeding depression of fitness-related traits in the development and adult stages was measured in a captive population of the adzuki bean beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). Beetles produced by full-sib matings had 8% lower survival in the development stage than did beetles produced by unrelated matings. Although inbred and outbred offspring did not differ in body size after emergence, inbred offspring took 2-3% longer to develop to emergence. This indicates inbreeding depression of growth rate. At the adult stage, inbreeding had no significant effect on longevity, however lifetime offspring production was reduced by 11%. Thus, the magnitude of inbreeding depression was relatively large for offspring production. This suggests inbreeding depression of fitness manifests, to a particularly significant extent, in reduced productivity. This study shows the C. chinensis population, which has been in captivity for more than 100 generations, harbors genetic loads. © 2010 The Ecological Society of Japan. Source

Fujisawa A.,Kyushu University
Plasma Physics and Controlled Fusion | Year: 2011

The modern view of plasma turbulence has been established due to the discovery of zonal flows and other structures which drift-waves generate, and contributes to exploring new manners of understanding turbulence-driven transport and structural formation in magnetized plasmas and astronomic objects. This paper presents the recent development of laboratory experiments, in particular, for drift-wave turbulence which have advanced understanding and have made the paradigm shift. The topics include the discovery of mesoscale structures, such as zonal flows and streamers, the recent development of analyzing techniques to quantify the couplings between different scale structures and methods to elucidate energy transfer direction, and turbulence transport and barrier formation. Finally, future experiments are suggested for establishing the first-principle laws of turbulence transport and structural formation. © 2011 IOP Publishing Ltd. Source

This paper empirically examines the dynamic causal relationships between carbon dioxide emissions, energy consumption, economic growth, trade openness and urbanization for the panel of newly industrialized countries (NIC) using the time series data for the period 1971-2007. Using four different panel unit root tests it is found that all panel variables are integrated of order 1. From the Johansen Fisher panel cointegration test it is found that there is a cointegration vector among the variables. The Granger causality test results support that there is no evidence of long-run causal relationship, but there is unidirectional short-run causal relationship from economic growth and trade openness to carbon dioxide emissions, from economic growth to energy consumption, from trade openness to economic growth, from urbanization to economic growth and from trade openness to urbanization. It is found that the long-run elasticity of carbon dioxide emissions with respect to energy consumption (1.2189) is higher than short run elasticity of 0.5984. This indicates that over time higher energy consumption in the newly industrialized countries gives rise to more carbon dioxide emissions as a result our environment will be polluted more. But in respect of economic growth, trade openness and urbanization the environmental quality is found to be normal good in the long-run. © 2011 Elsevier Ltd. Source

Quorum sensing is a cell-density dependent regulatory system, which orchestrates that quorum-sensing (QS) systems use extracellular signals to modulate the expression of a particular gene(s) in a bacterial cell, which results in virulence gene expression or biofilm formation and occasionally causes deadly plant and animal diseases. The frequent use of antibiotics to treat deadly diseases has led to the development of multiple drug-resistant bacterial strains. The increasing presence of pathogenic bacteria has thus forced us to develop alternative methods for controlling pathogen virulence. One such possible method, quorum quenching (QQ), has emerged as an interesting approach. A variety of bioactive molecules or drugs from prokaryotic or eukaryotic sources have been identified as QQ molecules, some of which are chemically synthesized, and the agonist or antagonist of their cognate receptor or metabolic intermediate was determined. Current strategies to attenuate the virulence of gene expression can be grouped into the following categories: (a) blockage of AHL-Lux-R-type binding sites, (b) inhibition of AHL-Lux-R- and Lux-I-type interactions, (c) inhibition of transporters, (d) degradation of existing AHLs by QQ enzymes and (e) inhibition of enzymes involved in the metabolic synthesis of QS molecules. This review summarises several potential QQ molecules that have been reported to attenuate QS-based virulence gene expression in serious Gram-negative pathogenic bacteria. These QQ molecules suggest possible ways of controlling the virulence effects of pathogenic bacteria in the post-antibiotic era. This journal is © The Royal Society of Chemistry 2015. Source

Sakaguchi H.,Kyushu University | Malomed B.A.,Tel Aviv University
Optics Express | Year: 2013

We introduce a three-dimensional (3D) model of optical media with the quadratic (X(2)) nonlinearity and an effective 2D isotropic harmonic-oscillator (HO) potential. While it is well known that 3D X(2) solitons with embedded vorticity (vortical light bullets) are unstable in the free space, we demonstrate that they have a broad stability region in the present model, being supported by the HO potential against the splitting instability. The shape of the vortical solitons may be accurately predicted by the variational approximation (VA). They exist above a threshold value of the total energy (norm) and below another critical value, which determines a stability boundary. The existence threshold vanishes is a part of the parameter space, depending on the mismatch parameter, which is explained by means of the comparison with the 2D counterpart of the system. Above the stability boundary, the vortex features shape oscillations, periodically breaking its axisymmetric form and restoring it. Collisions between vortices moving in the longitudinal direction are studied too. The collision is strongly inelastic at relatively small values of the velocities, breaking the two colliding vortices into three, with the same vorticity. The results suggest a possibility of the creation of stable 3D optical solitons with the intrinsic vorticity. © 2013 Optical Society of America. Source

Morohashi K.-I.,Kyushu University | Zubair M.,University of Michigan
Molecular and Cellular Endocrinology | Year: 2011

The orphan nuclear receptor AD4BP/SF-1 (adrenal-4-binding protein/steroidogenic factor-1 (NR5A1)) is essential for the proper development and function of reproductive and steroidogenic tissues. Although the expression of Ad4BP/Sf-1 is specific for those tissues, the mechanisms underlying this tissue-specific expression remain unknown. Our transgenic studies have identified the tissue-specific enhancers for the fetal adrenal cortex, ventromedial hypothalamus, and pituitary in Ad4BP/Sf-1 gene. The adrenal cortex forms morphologically distinct compartments, the inner (fetal) and outer (definitive or adult) zones. Despite considerable effort, the mechanisms that mediate the differential development of the fetal and adult adrenal cortex remain incompletely understood. It remained controversial whether a true fetal type adrenal cortex is present in mice, and this argument was complicated by the postnatal development of the so-called X-zone. Using transgenic mice with lacZ driven by the fetal adrenal enhancer (FAdE), we clearly identified a fetal adrenal cortex in mice, and the X-zone is the fetal adrenal cells accumulated at the juxtamedullary region after birth. We combined the FAdE with the Cre/loxP system to trace cell lineages in which the FAdE was active at some stage in development. These lineage tracing studies establish definitively that the adult cortex derives from precursor cells in the fetal cortex in which the FAdE was activated before the organization into two distinct zones. The potential of these fetal adrenocortical cells to enter the pathway that eventuate in cells of the adult cortex disappeared by E14.5. Thus, these studies demonstrate a direct link between the fetal and adult cortex involving a transition that must occur before a specific stage of development. © 2010 Elsevier Ireland Ltd. Source

Goto A.,Kyushu University
Virchows Archiv : an international journal of pathology | Year: 2011

Although Helicobacter pylori is a risk factor for gastric cancer (GC), its detailed carcinogenesis remains unclear. Recently, aberrant expression of activation-induced cytidine deaminase (AID) was demonstrated in gastric epithelium with H. pylori infection and seems to cause the accumulation of mutation. This investigation aims to elucidate whether or not AID expression plays an important role in the carcinogenesis of early GC. We examined the correlation between immunohistochemical AID expression and histological characteristics, including pre-existing chronic gastritis and cellular mucin phenotype in 138 cases of intramucosal GC. Furthermore, we investigated the relationship between AID, p53 protein, and β-catenin. The low degree of polymorphonuclear neutrophil activity, and the high degree of glandular atrophy and intestinal metaplasia were significantly correlated with the high levels of AID expression in non-neoplastic mucosa (P=0.007, P≤0.001, and P=0.003). With regard to mucin phenotype of carcinoma, the intestinal phenotype tended to have the higher AID expression levels (P=0.052). AID showed close correlations with Cdx2 and nuclear staining of β-catenin (P=0.003, P=0.034). As for p53 protein, no correlation was found with AID expression. Our findings suggest that aberrant AID expression is correlated with persistent inflammatory condition induced by H. pylori infection and may contribute to the development of GC through an inflammatory condition and intestinalization. Source

Kanki T.,Kyushu University | Klionsky D.J.,University of Michigan | Okamoto K.,Osaka University
Antioxidants and Redox Signaling | Year: 2011

The mitochondrion is an organelle that carries out a number of important metabolic processes such as fatty acid oxidation, the citric acid cycle, and oxidative phosphorylation. However, this multitasking organelle also generates reactive oxygen species (ROS), which can cause oxidative stress resulting in self-damage. This type of mitochondrial damage can lead to the further production of ROS and a resulting downward spiral with regard to mitochondrial capability. This is extremely problematic because the accumulation of dysfunctional mitochondria is related to aging, cancer, and neurodegenerative diseases. Accordingly, appropriate quality control of this organelle is important to maintain proper cellular homeostasis. It has been thought that selective mitochondria autophagy (mitophagy) contributes to the maintenance of mitochondrial quality by eliminating damaged or excess mitochondria, although little is known about the mechanism. Recent studies in yeast identified several mitophagy-related proteins, which have been characterized with regard to their function and regulation. In this article, we review recent advances in the physiology and molecular mechanism of mitophagy and discuss the similarities and differences of this degradation process between yeast and mammalian cells. © 2011 Mary Ann Liebert, Inc. Source

Tochihara H.,Kyushu University | Shirasawa T.,University of Tokyo
Progress in Surface Science | Year: 2011

Silicon carbide (SiC) has the potential to serve as an extremely important semiconductor material in next-generation electronics. However, a major stumbling block for its practical application has been the preparation of high-quality interfaces with insulating materials. We have discovered a way to prepare a 0.6-nm thick silicon oxynitride (SiON) layer having an epitaxial interface with the SiC(0 0 0 1) surface. This review article focuses on the atomic and electronic structures of the SiON layer. Based on various experimental techniques and theoretical studies, we understand the SiON layer to be a complex but unique hetero-double-layered structure: a topmost Si 2O5 monolayer is connected to an interfacial Si 2N3 monolayer via Si-O-Si linear bridge bonds. The most striking feature of the SiON structure is that there is no dangling bond in the unit cell, rendering it remarkably robust to air exposure. Stability and processes for the formation of the SiON on SiC(0 0 0 1) are discussed on the basis of the structural features obtained. Scanning tunneling spectroscopy measurements of the SiON exhibit a bulk SiO2-like band gap of ∼9 eV as well as first-principles calculations. The remarkable band-gap opening of such a thin insulator film is investigated by the combination of element-specific soft x-ray absorption/emission spectroscopies and by first-principles calculations, revealing the Si2N3 and Si2O5 monolayers to have band gaps of corresponding bulk-like values. Promising applications of the SiON to electronic devices are discussed. © 2011 Elsevier Ltd. All rights reserved. Source

Urano A.,Hokkaido University | Ando H.,Kyushu University
General and Comparative Endocrinology | Year: 2011

The hypothalamic neurosecretory cells (NSCs) which produce and release neurohypophysial hormones are involved in controls of diverse physiological phenomena including homeostatic controls of unconscious functions and reproduction. The far and wide distribution of neurosecretory processes in the discrete brain loci and the neurohypophysis is appropriate for coordination of neural and endocrine events that are required for the functions of NSCs. The presence of dye couplings and intimate contacts among NSCs supports harmonious production and release of hormone to maintain the plasma level within a certain range which is adequate for a particular physiological condition. Neurosecretory cells integrate diverse input signals from internal and external sources that define this particular physiological condition, although reactions of NSCs vary among different species, and among different cell types. An input signal to NSC is received by specific receptors and transduced as unique intracellular signals, important for the various functions of neurohypophysial hormones. Orchestration of multiple intracellular signaling systems, activities of which are individually modulated by input signals, determines the rates of synthesis and release of hormone through regulation of gene expression. The first step of gene expression, i.e., transcription, is amenable for diverse reaction of NSCs, because the 5′ upstream regions of genes encoding neurohypophysial hormones are highly variable. © 2010 Elsevier Inc. Source

Furue M.,Kyushu University
Annals of Dermatology | Year: 2011

Uncontrolled proliferation is a defining feature of the malignant phenotype. Nevertheless, the supportive network provided by the stroma is indispensable for further invasion, progression and metastasis of cancer cells. In addition, the role of inflammation in tumorigenesis is now generally accepted, and it has become evident that an inflammatory microenvironment is an essential component of tumor progression. Since skin tumors are common and easily assessable lesions with features at various stages of tumorigenesis, they provide a wide scope for research in this field to further our understanding of fundamental and clinical carcinogenesis. Some of the basic aspects of epithelial tumorigenesis, invasion and stromal reaction are reviewed in this paper. Source

Matsukiyo S.,Kyushu University
Physics of Plasmas | Year: 2010

The efficiency of electron heating through microinstabilities generated in the transition region of a quasiperpendicular shock for a wide range of Mach numbers is investigated by utilizing particle-in-cell (PIC) simulation and model analyses. In the model analyses saturation levels of effective electron temperature as a result of microinstabilities are estimated from an extended quasilinear (trapping) analysis for relatively low (high) Mach number shocks. Here, modified two-stream instability (MTSI) is assumed to become dominant in low Mach number regime, while Buneman instability (BI) is assumed to become dominant in high Mach number regime. It is revealed that Mach number dependence of the effective electron temperature in the MTSI dominant case is essentially different from that in the BI dominant case. The effective electron temperature through the MTSI does not depend much on the Mach number, although that through the BI increases with the Mach number as in the past studies. The results are confirmed to be consistent with the PIC simulations both in qualitative and quantitative levels. The model analyses predict that a critical Mach number, above which a steep rise in electron heating rate occurs, may arise at the Mach number of a few tens. © 2010 American Institute of Physics. Source

Watanabe A.,Kyushu University | Yoshioka K.,Kyoto University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

The seesaw-induced neutrino mass is discussed in a generic class of curved spacetime, including the flat and warped extra dimensions. For Majorana masses in the bulk and on the boundary, the exact forms of seesaw-induced masses are derived by using the Kaluza-Klein mode expansion and the lepton number violating correlator for bulk fermion. It is found that the neutrino mass is determined without the knowledge of wave functions and whole background geometry when the metric factor is fixed on the boundary, e.g. by solving the hierarchy problem. © 2009 Elsevier B.V. All rights reserved. Source

Ohtaki M.,Kyushu University
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2011

Rapid progress in thermoelectric performance of oxide materials has been conducted virtually exclusively in Japan, resulting in more than 10 times increase in the ZT values of oxides within the last two decades. This has caused a revolutionary change in the guiding principles of thermoelectric materials research, in which oxide materials had been disregarded as a potential candidate until early 1990s. Promising oxide thermoelectric materials having been discovered include CaMnO3-based perovskites, Al-doped ZnO, layered cobalt oxides represented by NaCo2O4 and Ca 3Co4O9, and SrTiO3-related phases. This paper reviews the current aspects of oxide thermoelectric materials, and some strategies of nanostructure control for selective reduction of the lattice thermal conductivity (selective phonon scattering) in bulk oxide ceramics will also be discussed. © 2011 The Ceramic Society of Japan. Source

Takeda T.,Kyushu University
Fukuoka igaku zasshi = Hukuoka acta medica | Year: 2011

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposed to pregnant or lactational mother impairs the reproduction and development of the pups. The defect is a serious problem, because it is caused by TCDD at much lower doses than that needed for acute toxicity in the mother. However, the toxic mechanism underlying the defect remains to be obscure. We have previously revealed that maternal exposure to TCDD (1 microg/kg) causes a reduction in luteinizing hormone in the fetal pituitary, leading to the reduced expression of testicular steroidogenic proteins such as steroidogenic acute-regulatory protein (StAR) and cytochrome P450 (CYP) 17. In addition, we have provided evidence that such a reduction imprints defects in sexual behaviors at adulthood. In this study, we investigated TCDD effect on fetal steroidogenesis in the extra-gonadal tissues. Even when pregnant Wistar rats at gestational day (GD) 15 were orally treated with TCDD (0.25, 1 or 3 microg/kg), neither expression of StAR nor CYP17 mRNA was affected in the adrenal gland, placenta and hypothalamus of male fetuses (GD20). However, TCDD induced placental StAR (3 microg/kg) and adrenal CYP17 mRNAs (0.25 microg/kg) in female fetuses. Therefore, our study suggests that while TCDD gives damage to male fetal steroidogenesis in a testis-specific manner, the dioxin enhances the steroidogenesis of the fetal adrenal gland and placenta in females. Thus, the mechanism whereby TCDD exerts its endocrine-disrupting properties is considered to differ, at least partially, between male and female fetuses. Source

Activation of the sympathetic nervous system has an important role in the pathogenesis of hypertension. However, the precise mechanisms involved are not fully understood. Oxidative stress may be important in hypertension as well as in other cardiovascular disorders. We investigated the role of oxidative stress, particularly in the rostral ventrolateral medulla (RVLM), which is known as the cardiovascular center in the brainstem, in the activation of the sympathetic nervous system in hypertension. We observed that the reactive oxygen species (ROS) production increases in the RVLM in hypertensive rats, thereby enhancing the central sympathetic outflow, which leads to hypertension. Furthermore, the environmental factors of high salt intake and a high-calorie diet may also increase the ROS production in the RVLM, thereby activating the central sympathetic outflow and increasing the risk of hypertension. The activation of the nicotinamide adenine dinucleotide phosphate oxidase via the angiotensin type 1 (AT1) receptors is suggested to be the major source of ROS production, and an altered downstream signaling pathway is involved in the activation of the RVLM neurons, leading to enhanced central sympathetic outflow and hypertension. Thus, the brain AT1 receptors may be novel therapeutic targets, and, in fact, oral treatment with angiotensin receptor blockers has been found to inhibit the central AT1 receptors, despite the blood-brain barrier. © 2011 The Japanese Society of Hypertension All rights reserved. Source

Itaba S.,Kyushu University
Digestive endoscopy : official journal of the Japan Gastroenterological Endoscopy Society | Year: 2011

Mainstream therapy for early gastric cancer in Japan has now shifted from endoscopic mucosal resection (EMR) to endoscopic submucosal dissection (ESD). Although bacteremia is reported as being infrequent and transient in gastric EMR, there are no reports of it being investigated in gastric ESD. This study aimed to determine the frequency of bacteremia in gastric ESD. A prospective study, in 46 consecutive patients who underwent gastric ESD, investigated the frequency of bacteremia before and after the procedure. Results: The median time for the total ESD procedure was 105min (range 30-400). The median volume of the submucosal injection was 80ml (range 20-260). The mean size of the resected specimen was 40±9.7mm. Blood cultures obtained before ESD were positive in 4.4% (2/45) of cases. Bacillus subtilis and Bacillus spp. were the isolated microorganisms. Blood cultures obtained 10min after ESD were positive in 4.3% (2/46) of cases; with the same microorganisms being isolated. Blood cultures obtained 3h after ESD were all negative. No signs of sepsis were seen in the two patients with a positive blood culture 10min after ESD. The frequency of bacteremia after gastric ESD was low and transient. ESD for gastric lesions is thought to have a low risk of infectious complications; therefore, prophylactic administration of antibiotics may not be warranted. © 2010 The Authors. Digestive Endoscopy © 2010 Japan Gastroenterological Endoscopy Society. Source

The discovery of a specific biomarker for neuromyelitis optica (NMO), NMO-immunoglobulin G (IgG)/anti-aquaporin-4 (AQP4) antibody, requires us to take it into account when interpreting epidemiological findings on multiple sclerosis (MS). Recent genetic studies showed that HLA-DRB1*0405 is the most common susceptibility allele for non-NMO MS in Japanese, and that DRB1*0405 carriers comprise >40% of all Japanese MS patients. Thus, idiopathic central nervous system demyelinating disease in Japanese can be subclassified into DRB1*0405-positive and -negative MS, and anti-AQP4 antibody-positive and -negative NMO. HLA-DRB1*0405-positive MS patients show younger age at onset, fewer brain lesions and a slower progression. The recent increase in the numbers of MS patients in this subgroup could explain the decrease in age at onset, as shown by the fourth nationwide survey in Japanese MS patients. Among HLA-DRB1*0405-negative MS patients, DRB1*1501 is a risk factor for MS, and DRB1*1501 carriers have high frequencies of brain lesions fulfilling the Barkhof criteria and cerebrospinal fluid IgG abnormalities. HLA-DRB1*0405-negative MS patients have higher frequencies of Epstein-Barr virus infection, but a lower frequency of Helicobacter pylori infection, which reflects improved sanitation in childhood. Anti-AQP4 antibody-positive NMO is associated with H. pylori and Chlamydia pneumoniae infections. The effects of improved sanitation on this subgroup might explain the decrease in incidence of opticospinal MS with longitudinally extensive spinal cord lesions, regarded as the same disease as NMO, as suggested by the fourth nationwide survey. Therefore, changes in environmental factors could have differentially influenced susceptibility to each disease subtype in Japanese. © 2013 Japanese Society for Neuroimmunology. Source

Yonamine Y.,University of California at Irvine | Hoshino Y.,Kyushu University | Shea K.J.,University of California at Irvine
Biomacromolecules | Year: 2012

Synthetic polymer nanoparticles (NPs) that display high affinity to protein targets have significant potential for medical and biotechnological applications as protein capture agents or functional replacements of antibodies ("plastic antibodies"). In this study, we modified an immunological assay (enzyme-linked immunosorbent assay: ELISA) into a high-throughput screening method to select nanoparticles with high affinity to target proteins. Histone and fibrinogen were chosen as target proteins to demonstrate this concept. The selection process utilized a biotinylated NP library constructed with combinations of functional monomers. The screen identified NPs with distinctive functional group compositions that exhibited high affinity to either histone or fibrinogen. The variation of protein affinity with changes in the nature and amount of functional groups in the NP provided chemical insight into the principle determinants of protein-NP binding. The NP affinity was semiquantified using the ELISA-mimic assay by varying the NP concentrations. The screening results were found to correlate with solution-based assay results. This screening system utilizing a biotinylated NP is a general approach to optimize functional monomer compositions and can be used to rapidly search for synthetic polymers with high (or low) affinity for target biological macromolecules. © 2012 American Chemical Society. Source

Kirillov O.N.,Helmholtz Center Dresden | Stefani F.,Helmholtz Center Dresden | Fukumoto Y.,Kyushu University
Astrophysical Journal | Year: 2012

The magnetorotational instability (MRI) plays a key role for cosmic structure formation by triggering turbulence in the rotating flows of accretion disks that would be otherwise hydrodynamically stable. In the limit of smallmagnetic Prandtl number, the helical and the azimuthal versions of MRI are known to be governed by a quite different scaling behavior than the standard MRI with a vertical applied magnetic field. Using the short-wavelength approximation for an incompressible, resistive, and viscous rotating fluid, we present a unified description of helical and azimuthal MRI, and we identify the universal character of the Liu limit 2(1-√2) ≈-0.8284 for the critical Rossby number. From this universal behavior we are also led to the prediction that the instability will be governed by a mode with an azimuthal wavenumber that is proportional to the ratio of axial to azimuthal applied magnetic field, when this ratio becomes large and the Rossby number is close to the Liu limit. © 2012. The American Astronomical Society. All rights reserved. Source

Nagano T.,Kawasaki University of Medical Welfare | Tokita M.,Kyushu University
Food Hydrocolloids | Year: 2011

Heat-induced gels of 11S globulin (11S) or soybean protein isolate (SPI) were prepared using magnesium chloride (MgCl2) as a coagulant. Viscoelastic properties and microstructures of 11S and SPI gels were quantified using dynamic viscoelastic measurement (DVM) and confocal laser scanning microscopy (CLSM). The addition of sodium chloride was necessary for 11S and SPI to form MgCl2-induced gels. DVM indicated that 11S formed stiffer and more solid gels than SPI under all experimental conditions. CLSM showed that the microstructures of 11S gels were coarser and more heterogeneous than SPI gels in comparable conditions. The microstructures of 11S gels were highly affected by MgCl2 concentration whereas those of SPI gels were relatively insensitive to MgCl2 concentration. The microstructures of 11S and SPI gels were analyzed by two parameters: the fractal dimension and the average density of gel networks. Compared to SPI, 11S forms MgCl2-induced gels with a lower fractal dimension and a higher density of network structures. © 2011 Elsevier Ltd. Source

Nakada M.,Kyushu University | Karato S.-I.,Yale University
Physics of the Earth and Planetary Interiors | Year: 2012

Viscosity of the D' layer of the Earth's mantle, the lowermost layer in the Earth's mantle, controls a number of geodynamic processes, but a robust estimate of its viscosity has been hampered by the lack of relevant observations. A commonly used analysis of geophysical signals in terms of heterogeneity in seismic wave velocities suffers from major uncertainties in the velocity-to-density conversion factor, and the glacial rebound observations have little sensitivity to the D' layer viscosity. We show that the decay of Chandler wobble and semi-diurnal to 18.6years tidal deformation combined with the constraints from the postglacial isostatic adjustment observations suggest that the effective viscosity in the bottom ∼300km layer is 10 19-10 20Pas, and also the effective viscosity of the bottom part of the D' layer (∼100km thickness) is less than 10 18Pas. Such a viscosity structure of the D' layer would be a natural consequence of a steep temperature gradient in the D' layer, and will facilitate small scale convection and melt segregation in the D' layer. © 2011 Elsevier B.V. Source

Machida M.N.,Kyushu University | Matsumoto T.,Hosei University
Monthly Notices of the Royal Astronomical Society | Year: 2012

The effects of a protostellar outflow on the star formation in a single cloud core are investigated by three-dimensional resistive magnetohydrodynamic (MHD) simulations. Starting from the pre-stellar cloud core, the star formation process is calculated until the end of the main accretion phase. In the calculations, the mass of the pre-stellar cloud is parametrized. During the star formation, the protostellar outflow is driven by the circumstellar disc. The outflow extends also in the transverse direction until its width becomes comparable to the initial cloud scale, and thus the outflow has a wide opening angle of ≳40°. As a result, the protostellar outflow sweeps up a large fraction of the infalling material and ejects it into the interstellar space. The outflow can eject at most over half of the host cloud mass, significantly decreasing the star formation efficiency. The outflow power is stronger in clouds with a greater initial mass. Thus, the protostellar outflow effectively suppresses the star formation efficiency in a massive cloud. The outflow weakens significantly and disappears in several free-fall time-scales of the initial cloud after the cloud begins to collapse. The natal pre-stellar core influences the lifetime and size of the outflow. At the end of the main accretion phase, a massive circumstellar disc comparable in mass to the protostar remains. Calculations show that ~26-54 per cent of the initial cloud mass is converted into the protostar and ~8-40 per cent remains in the circumstellar disc, while ~8-49 per cent can be ejected into the interstellar space by the protostellar outflow. Therefore, the protostellar outflow can decrease the star formation efficiency to ~50 per cent at the maximum. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS. Source

Kurishita Y.,Kyoto University | Kohira T.,Kyoto University | Ojida A.,Kyushu University | Hamachi I.,Kyoto University | Hamachi I.,Japan Science and Technology Agency
Journal of the American Chemical Society | Year: 2012

ATP and its derivatives (nucleoside polyphosphates (NPPs)) are implicated in many biological events, so their rapid and convenient detection is important. In particular, live cell detection of NPPs at specific local regions of cells could greatly contribute understanding of the complicated roles of NPPs. We report herein the design of two new fluorescent chemosensors that detect the dynamics of NPPs in specific regions of living cells. To achieve imaging of NPPs on plasma membrane surfaces (2-2Zn(II)), a lipid anchor was introduced into xanthene-based Zn(II) complex 1-2Zn(II), which was previously developed as a turn-on type fluorescent chemosensor for NPPs. Meanwhile, for subcellular imaging of ATP in mitochondria, we designed rhodamine-type Zn(II) complex 3-2Zn(II), which possesses a cationic pyronin ring instead of xanthene. Detailed spectroscopic studies revealed that 2-2Zn(II) and 3-2Zn(II) can sense NPPs with a several-fold increase of their fluorescence intensities through a sensing mechanism similar to 1-2Zn(II), involving binding-induced recovery of the conjugated form of the xanthene or pyronin ring. In live cell imaging, 2-2Zn(II) containing a lipid anchor selectively localized on the plasma membrane surface and detected the extracellular release of NPPs during cell necrosis induced by streptolysin O. On the other hand, rhodamine-type complex 3-2Zn(II) spontaneously localized at mitochondria inside cells, and sensed the local increase of ATP concentration during apoptosis. Multicolor images were obtained through simultaneous use of 2-2Zn(II) and 3-2Zn(II), allowing detection of the dynamics of ATP in different cellular compartments at the same time. © 2012 American Chemical Society. Source

Toyokuni G.,Japan National Institute of Polar Research | Takenaka H.,Kyushu University
Physics of the Earth and Planetary Interiors | Year: 2012

We propose a method for modeling global seismic wave propagation through an attenuative Earth model including the center. This method enables accurate and efficient computations since it is based on the 2.5-D approach, which solves wave equations only on a 2-D cross section of the whole Earth and can correctly model 3-D geometrical spreading. We extend a numerical scheme for the elastic waves in spherical coordinates using the finite-difference method (FDM), to solve the viscoelastodynamic equation. For computation of realistic seismic wave propagation, incorporation of anelastic attenuation is crucial. Since the nature of Earth material is both elastic solid and viscous fluid, we should solve stress-strain relations of viscoelastic material, including attenuative structures. These relations represent the stress as a convolution integral in time, which has had difficulty treating viscoelasticity in time-domain computation such as the FDM. However, we now have a method using so-called memory variables, invented in the 1980s, followed by improvements in Cartesian coordinates. Arbitrary values of the quality factor (Q) can be incorporated into the wave equation via an array of Zener bodies. We also introduce the multi-domain, an FD grid of several layers with different grid spacings, into our FDM scheme. This allows wider lateral grid spacings with depth, so as not to perturb the FD stability criterion around the Earth center. In addition, we propose a technique to avoid the singularity problem of the wave equation in spherical coordinates at the Earth center. We develop a scheme to calculate wavefield variables on this point, based on linear interpolation for the velocity-stress, staggered-grid FDM. This scheme is validated through a comparison of synthetic seismograms with those obtained by the Direct Solution Method for a spherically symmetric Earth model, showing excellent accuracy for our FDM scheme. As a numerical example, we apply the method to simulate seismic waves affected by hemispherical variations of P-wavespeed and attenuation in the top 300. km of the inner core. © 2012 Elsevier B.V.. Source

Iwasa Y.,Kyushu University | Michor F.,Dana-Farber Cancer Institute
PLoS ONE | Year: 2011

Intraneoplastic diversity in human tumors is a widespread phenomenon of critical importance for tumor progression and the response to therapeutic intervention. Insights into the evolutionary events that control tumor heterogeneity would be a major breakthrough in our comprehension of cancer development and could lead to more effective prevention methods and therapies. In this paper, we design an evolutionary mathematical framework to study the dynamics of heterogeneity over time. We consider specific situations arising during tumorigenesis, such as the emergence of positively selected mutations ("drivers") and the accumulation of neutral variation ("passengers"). We perform exact computer simulations of the emergence of diverse tumor cell clones over time, and derive analytical estimates for the extent of heterogeneity within a population of cancer cells. Our methods contribute to a quantitative understanding of tumor heterogeneity and the impact of heritable alterations on this tumor trait. © 2011 Iwasa, Michor. Source

Kubota K.,Kyushu University
The Journal of bone and joint surgery. American volume | Year: 2013

The pathomechanism underlying idiopathic scoliosis remains unclear, and, to our knowledge, a consistent and relevant animal model has not been established previously. The goal of this study was to examine whether a disturbance of rib cage development is a causative factor for scoliosis and to establish a nonsurgical mouse model of progressive scoliosis. To examine the relationship between rib cage development and the pathogenesis of progressive scoliosis, a plastic restraint limiting anteroposterior rib cage development was placed on the chest of four-week-old mice. All mice were evaluated with whole-spine radiographs, and the severity of scoliosis was consecutively measured. The rib cage rotation angle and the anteroposterior chest dimension were measured with use of micro-computed tomography scanning. To examine whether the imbalanced load transmission through the ribs to the vertebral body was involved in our model, we performed a rib-neck osteotomy in a subgroup of the mice. The thoracic restraint did not provoke spinal curvature immediately after it was applied, but nine of ten mice that wore the restraint but did not have rib osteotomy gradually developed progressive scoliosis. Radiographs and computed tomography images showed a right thoracic curvature, vertebral rotation, and narrow chest in the mice that had worn the restraint for eleven weeks but did not have rib osteotomy even after the restraint was removed. The anteroposterior chest dimension was significantly correlated with both the curve magnitude and the rib cage rotation angle. The progression of spinal deformity was observed only during the adolescent growth spurt, and it plateaued thereafter. The left-side rib osteotomy led to the development of progressive left-thoracic curvature, whereas the bilateral rib osteotomy did not cause scoliosis, even with restraint wear. We established a nonsurgical experimental model of progressive scoliosis and also demonstrated that a rib cage deformity with an imbalanced load to the vertebral body resulted in progressive structural scoliosis. Source

Phongsisay V.,Kyushu University
Molecular Immunology | Year: 2015

jejuni interacts directly with C-type lectin and immunoglobulin-like receptors. jejuni interacts preferentially with LMIR5 among various receptors examined. jejuni activates transcriptional factor NFAT through DAP12-coupled LMIR5. Campylobacter jejuni causes gastroenteritis and Guillain-Barré syndrome. Host immunity plays an important role in the disease pathogenesis; however, little is known about the immune receptors for C. jejuni. We report here that C. jejuni targets C-type lectin (SIGNR1, SIGNR3) and immunoglobulin-like receptors (TREM2, TREM3, LMIR5, LMIR8). Among these, C. jejuni interacted preferentially with LMIR5, which was selected for further verification using reporter cells. LMIR5 ligation by C. jejuni activated transcriptional factor NFAT through adaptor protein DAP12. Furthermore, LMIR5 activators were identified as protein components, RNA-associated proteins, and 150-kDa high-molecular-weight glycoconjugates. This finding discloses potential receptors that might link C. jejuni to immunopathology. © 2014 Elsevier Ltd. Source

Natural orifice translumenal endoscopic surgery (NOTES) is a sophisticated form of endoscopic surgery whose use has recently spread rapidly around the world. Although hundreds of reports of animal studies and clinical cases about NOTES have been published since 2004, NOTES is still in the experimental phase. The formation of an iatrogenic incision in the lumenal wall of intraperitoneal organs is a major disadvantage of NOTES. No reliable technique for complete closure has yet been established, and this problem must be resolved before NOTES can be adopted as a routine clinical practice. Several devices for the closure of lumenal incisions in the stomach or colorectum have been developed, and their safety and usefulness have been examined in animal studies and clinical cases. Kyushu University has been involved in furthering the adoption of NOTES as a routine clinical practice, and the Kyushu University Training Center for Minimally Invasive Surgery holds training sessions on endoscopic surgical techniques for surgeons from all over Japan. Studies to develop a navigation system and robotic technology for use with NOTES are also in progress at Kyushu University. The further development of endoscopy-related technologies and equipment, such as robotic technology, is therefore essential to allow the safe, widespread adoption of pure NOTES. Source

Kai T.,Kyushu University
Acta Astronautica | Year: 2012

In this paper, we develop a new control strategy on limit cycles for planar space robot models with initial angular momenta. First, we state our problem formulation, and give some concepts and assumptions. Next, we derive a controller that generates a desired stable limit-cycle-like behavior for general two-dimensional nonlinear control systems, which is called limit-cycle-like control. We then give two kinds of specific forms of the controller and investigate some characteristics of them. After that, we apply the limit-cycle-like control methods to a control problem of a planar space robot model with an initial angular momentum, and some simulations are carried out in order to demonstrate the effectiveness of our new methods. © 2012 Elsevier Ltd. All rights reserved. Source

Bergstrom L.M.,Institute of Chemical Technology | Aratono M.,Kyushu University
Soft Matter | Year: 2011

Expressions for the critical micelle concentration (cmc) and activity coefficients as functions of surfactant composition in mixtures of two identically charged monovalent ionic surfactants are derived from the nonlinear Poisson-Boltzmann (PB) theory. For the special case of no added salt, the simple expression cmc α = xcmcα1 + (1 - x)cmcα2 is deduced, where the exponential parameter α > 1 depends on the number of ionic species in a surfactant molecule as well as the curvature of the self-assembled interface. Theoretical predictions are compared with cmc values obtained with some different experimental techniques for mixtures of the two cationic surfactants didodecyldimethylammonium bromide (DDAB) and dodecyltrimethylammonium bromide (DTAB) in water and in the absence of added salt. It is demonstrated that the PB theory generates significantly better agreement with experimental data than predicted by ideal behaviour or the regular mixture theory. We find that maximum synergistic effects occur at a DDAB mole fraction in solution y = 0.005. According to the PB theory, this very low value of y corresponds to a mole fraction of DDAB in the self-assembled interfacial aggregates equal to x = 0.995. Moreover, our calculations of the surfactant composition in the self-assembled interfacial aggregates above cmc demonstrate that the transition from small micelles to large bilayer aggregates is found to consistently occur at a mole fraction of DDAB equal to about x = 0.41-0.42, irrespective of the surfactant molar ratio in solution. Experimental observations strongly support the fact that concentrations of free surfactant, as well as the surfactant composition in the self-assembled interfacial aggregates, may be accurately calculated from the non-linear Poison-Boltzmann theory. On the other hand, a micelle-to-bilayer transition induced by changes in surfactant mole fraction in the self-assembled interfacial aggregates is consistent with neither ideal surfactant behaviour nor synergistic behaviour according to the regular mixture theory. © 2011 The Royal Society of Chemistry. Source

Kikuuwe R.,Kyushu University
IEEE/ASME Transactions on Mechatronics | Year: 2014

This paper proposes a new position controller that is suitable for the use as the internal position servo of an admittance controller with bounded actuator forces. The new position controller approximately behaves as a proportional-integral-derivative (PID) controller with an acceleration feedforward in normal situations and as a sliding mode controller when the actuator force is saturated. The admittance controller employing the new position controller realizes smooth transitions between saturated periods and unsaturated periods. Moreover, it quickly responds to changes in the applied force even when the actuator force is saturated, leading to better stability and smoothness. The controller was validated through experiments using a robotic manipulator. © 1996-2012 IEEE. Source

Mejia-Alvarez R.,University of Illinois at Urbana - Champaign | Mejia-Alvarez R.,Los Alamos National Laboratory | Christensen K.T.,Kyushu University
Physics of Fluids | Year: 2013

Stereo particle-image velocimetry measurements were conducted in a streamwise-spanwise (x - z) plane deep within the roughness sublayer (y = 0.047δ; δ is the boundary-layer thickness) of a zero-pressure-gradient turbulent boundary layer overlying highly irregular surface roughness replicated from a turbine blade damaged by foreign-material deposition. The ensemble-averaged streamwise velocity defect revealed the tendency of the roughness to promote channeling of the flow in the form of low-momentum pathways (LMPs) and high-momentum pathways. Enhanced turbulent and vortical activity was observed both between and along the spanwise boundaries of these streamwise-elongated pathways. In particular, streamwise pathways of wall-normal vortex cores of opposing rotational sense were observed along the spanwise boundaries of the identified LMP in the rough-wall flow. Conditional averaging revealed that these counter-rotating vortical motions are associated with streamwise flow against the mean-flow direction and could perhaps be the origination mechanism of the LMPs. Two-point correlation coefficients of velocity and swirling strength reflected large-scale streamwise coherence of these quantities along and outboard of the identified LMP in the rough-wall flow, supporting the notion that the motions responsible for the LMP have large-scale, streamwise coherence. Finally, the influence of different topographical scales of the roughness on the flow in the roughness sublayer was explored using low-order models of the original, full surface as originally proposed by R. Mejia-Alvarez and K. T. Christensen [Phys. Fluids22(1), 015106 (2010)]. While a model containing only the largest topographical scales qualitatively reproduced the features of the full-surface flow, additional intermediate topographical scales were required to quantitatively reproduce the statistical and structural nature of the full-surface flow in the roughness sublayer. © 2013 AIP Publishing LLC. Source

The prognosis of gallbladder cancer (GBC) remains poor despite recent advances in diagnostics and therapeutic strategies. Although the role of microRNAs (miRs) in GBC have not been well documented, miR-155 is known to be associated with inflammation-associated carcinogenesis in various types of cancers. The aim of this study was to investigate the clinical significance of miR-155 expression and the biological functions of miR-155 in GBC. The expression levels of miR-155 in surgically resected GBCs and gallbladders with pancreaticobiliary maljunction (PBM) were assessed by quantitative reverse transcription-polymerase chain reaction. The relationship between the expression levels of miR-155 and clinicopathological features of GBCs was analyzed. Human GBC cell lines were transfected with miR-155 inhibitors or mimics, and the effects on proliferation and invasion were assessed. miR-155 was significantly overexpressed in GBCs when compared with that in gallbladders with PBM (p=0.007) and normal gallbladders (p=0.04). The high expression level of miR-155 in GBCs was significantly associated with the presence of lymph node metastasis (p=0.01) and a poor prognosis (p=0.02). In vitro assays showed that aberrant expression of miR-155 significantly enhanced GBC cell proliferation and invasion. In conclusion, high miR-155 expression correlates with the aggressive behavior of GBCs, and miR-155 may become a prognostic marker and therapeutic target for GBC. Source

On the basis of its CO 2 compensation concentration, Brassica gravinae Ten. has been reported to be a C 3-C 4 intermediate. This study investigated the structural and biochemical features of photosynthetic metabolism in B. gravinae. The cellular distribution of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) was also examined in B. gravinae, B. napus L. (C 3), Raphanus sativus L. (C 3), and Diplotaxis tenuifolia (L.) DC. (C 3-C 4) by immunogold electron microscopy to elucidate Rubisco expression during the evolution from C 3 to C 3-C 4 intermediate plants. The bundle sheath (BS) cells of B. gravinae contained centrifugally located chloroplasts as well as centripetally located chloroplasts and mitochondria. Glycine decarboxylase P-protein was localized in the BS mitochondria. Brassica gravinae had low C 4 enzyme activities and high activities of Rubisco and photorespiratory enzymes, suggesting that it reduces photorespiratory CO 2 loss by the glycine shuttle. In B. gravinae, the labelling density of Rubisco was higher in the mesophyll chloroplasts than in the BS chloroplasts. A similar cellular pattern was found in other Brassicaceae species. These data demonstrate that, during the evolution from C 3 to C 3-C 4 intermediate plants, the intercellular pattern of Rubisco expression did not change greatly, although the amount of chloroplasts in the BS cells increased. It also appears that intracellular variation in Rubisco distribution may occur within the BS cells of B. gravinae. © 2011 The Author. Source

Yamawaki Y.,Kyushu University
Journal of Insect Physiology | Year: 2011

Defence responses to approaching objects were observed in the mantis Tenodera aridifolia. The mantis showed three kinds of behaviour, fixation, evasion and cryptic reaction. The cryptic reaction consisted of rapid retraction of the forelegs under the prothorax or rapid extending of the forelegs in the forward direction. Obstructing the mantis' sight decreased its response rates, suggesting that the visual stimuli generated by an approaching object elicited the cryptic reaction. The response rate of the cryptic reactions was highest for objects that approached on a direct collision course. Deviation in a horizontal direction from the direct collision course resulted in a reduced response. The response rate of the cryptic reaction increased as the approaching velocity of the object increased, and the rate decreased as the object ceased its approach at a greater distance from the mantis. These results suggest that the function of the observed cryptic reactions is defence against impending collisions. The possible role of the looming-sensitive neuron in the cryptic reaction is also discussed. © 2011 Elsevier Ltd. Source

Fujioka K.,Kyushu University
Information and Computation | Year: 2011

This paper concerns new characterizations of regular, context-free, and recursively enumerable languages, using insertion systems with lower complexity. This is achieved by using both strictly locally testable languages and morphisms. The representation is in a similar way to the Chomsky- Schützenberger representation of context-free languages. Specifically, each recursively enumerable language L can be represented in the form L=h(L(γ)∩R), where γ is an insertion system of weight (3,3), R is a strictly 2-testable language, and h is a projection. A similar representation can be obtained for context-free languages, using insertion systems of weight (2,0) and strictly 2-testable languages, as well as for regular languages, using insertion systems of weight (1,0) and strictly 2-testable languages. © 2010 Elsevier Inc. All rights reserved. Source

In 2 × 2 prisoner's dilemma games, network reciprocity is one mechanism for adding social viscosity, which leads to cooperative equilibrium. Here we show that combining the process for selecting a gaming partner with the process for selecting an adaptation partner significantly enhances cooperation, even though such selection processes require additional costs to collect further information concerning which neighbor should be chosen. Based on elaborate investigations of the dynamics generated by our model, we find that high levels of cooperation result from two kinds of behavior: cooperators tend to interact with cooperators to prevent being exploited by defectors and defectors tend to choose cooperators to exploit despite the possibility that some defectors convert to cooperators. © 2014 IOP Publishing Ltd and SISSA Medialab srl. Source

Kiyohara C.,Kyushu University
Fukuoka igaku zasshi = Hukuoka acta medica | Year: 2011

Many but not all studies have indicated that smoking is inversely associated with Parkinson's disease (PD). Meta-analysis of epidemiological studies on smoking and PD was performed to summarize data from published studies. Fifty-four epidemiological studies (48 case-control and 6 cohort studies, 53 publications) were identified for potential inclusion in meta-analysis. The summary risk estimates for current smokers, former smokers, and ever (current and former) smokers were 0.31 (95% confidence interval (CI) = 0.25-0.38), 0.72 (95% CI = 0.63-0.83) and 0.55 (95% CI = 0.51-0.59), respectively. In stratified analysis by study design, smoking had a somewhat greater impact on PD risk in cohort studies than in case-control studies. However, meta-regression indicated that the study design did not significantly contribute to heterogeneity. Additional analyses were restricted to case-control studies because of the sufficient number of studies. Stratified analysis by ethnicity indicated that the summary OR for ever-smokers was nonsignificantly smaller in Asian populations than in Caucasian populations. In stratified analysis by source of controls, former smoking was significantly associated with a decreased risk of PD in hospital-based case-control studies but was marginally associated with a decreased risk in population-based case-control studies. The source of controls did not contribute significantly to heterogeneity. PD risk associated with ever-smoking was significantly lower for a hospital-based approach than a population-based approach. Among current smokers, the association held true to the same extent for both approaches. This meta-analysis indicated that smokers have a lower risk of PD. As PD is a multifactorial disease, further investigation of the smoking-gene interaction on PD risk may lead to a better understanding of the pathogenesis of PD. Source

Kimura H.,Kyushu University
RINA, Royal Institution of Naval Architects - International Conference on Computer Applications in Shipbuilding 2011, Papers | Year: 2011

Automatic design of piping layout is challenging since it is composed of several numerical and/or combinational optimization problems, e.g., routing problems of pipes including branches, and arrangement problems of equipments. This paper presents a new approach that the branches of pipes are considered to be a variety of equipment. Accordingly, the pipe routing problems are fairly simplified by removing the branches, and it derives a lot of efficient algorithms to solve the pipe arrangement problems. One is a multi-objective genetic algorithm (MOGA) in which the gene represents both the locations of the equipments and the arrangement of the pipes. And a new crossover operation which merges two different piping layouts is proposed. To provide a fairly good initial population for the MOGA, a new heuristics making use of self-organization techniques to arrange equipments is proposed. The efficiency of the approach is demonstrated through two experiments, one is a designing problem including five valves, one pump, and five branches, and the other includes seven valves, one pump, and six branches. ©2011: The Royal Institution of Naval Architects. Source

Abe K.-I.,Kyushu University
International Journal of Heat and Fluid Flow | Year: 2013

An improved subgrid-scale (SGS) model was proposed by combining an isotropic linear eddy-viscosity term with an extra anisotropic term. In the present study, primary attention was given to maintaining the computational stability while improving the predictive performance particularly for coarse grid resolution in the near-wall region. For the extra anisotropic term used for this purpose, the present study introduced a residual term after subtracting an eddy-viscosity form from the Bardina SGS-Reynolds-stress model [Bardina, J., Ferziger, J.H., Reynolds, W.C., 1980. Improved subgrid scale models for large eddy simulation. AIAA Paper 80-1357]. The resultant extra term yields no undesirable extra energy transfer between the grid-scale and SGS components that could cause numerical instability under coarse grid conditions. Therefore, this extra term is not expected to have any serious negative effects on the computational stability. In order to assess the performance, the proposed model was applied to the numerical simulation of fully-developed plane channel flows with various grid resolutions and at various Reynolds numbers. The computational results were considerably improved by the present SGS model and detailed investigations of the obtained results indicated the usefulness of the present model for engineering applications. © 2012 Elsevier Inc. Source

Matsumoto Y.,Kyushu University
Nihon Hoshasen Gijutsu Gakkai zasshi | Year: 2014

In postoperative radiotherapy for seminoma, control of the testicular absorbed dose is important, since exposure of the testis can lead to temporary or permanent infertility. In this case, instead of using a dog-leg-shaped field, treatment using a field focused near the aorta was provided in several disease stages of seminoma. However, the precise need for testicular shielding during treatment and dose of testis exposure was not clear. We examined these questions by measuring the testicular absorbed dose with and without a testicular shield using two clinical treatment plans and a phantom. The distance from the testis phantom and the lower end of the irradiation field was varied. Where the total dose for the tumor was 20 Gy, the testicular absorbed dose was below 0.1 Gy, the threshold dose for temporary infertility. At this dosage, the distance between the testis phantom and the edge of the irradiation field was 14.6 cm without the shield and 9.99 cm with the shield. Using a testes shield, it was thus possible to reduce the dose by 58.5%. Source

Bishop S.R.,Kyushu University
Acta Mechanica Sinica/Lixue Xuebao | Year: 2013

The importance of oxygen non-stoichiometry induced expansion, known as chemical expansion, for the mechanical properties of solid oxide fuel cells (SOFCs) is discussed. The methods used to measure chemical expansion and the defects responsible for its existence are introduced. Recent work demonstrating the origin of chemical expansion in fluorite structured oxides for SOFCs is presented. Models used to predict stress induced by chemical expansion in SOFCs, highlighting the necessity of considering electrochemo-mechanical coupling relationships, are discussed. © The Chinese Society of Theoretical and Applied Mechanics and Springer-Verlag Berlin Heidelberg 2013. Source

Zendo T.,Kyushu University
Bioscience, Biotechnology and Biochemistry | Year: 2013

Bacteriocins produced by lactic acid bacteria (LAB) are expected to be safe antimicrobial agents. While the best studied LAB bacteriocin, nisin A, is widely utilized as a food preservative, various novel ones are required to control undesirable bacteria more effectively. To discover novel bacteriocins at the early step of the screening process, we developed a rapid screening system that evaluates bacteriocins produced by newly isolated LAB based on their antibacterial spectra and molecular masses. By means of this system, various novel bacteriocins were identified, including a nisin variant, nisin Q, a two-peptide bacteriocin, lactococcin Q, a leaderless bacteriocin, lacticin Q, and a circular bacteriocin, lactocyclicin Q. Moreover, some LAB isolates were found to produce multiple bacteriocins. They were characterized as to their structures, mechanisms of action, and biosynthetic mechanisms. Novel LAB bacteriocins and their biosynthetic mechanisms are expected for applications such as food preservation and peptide engineering. Source

Koyanagi A.,Hatsuishi Hospital | Zhang J.,Shanghai Key Laboratory of Childrens Environmental Health | Dagvadorj A.,University of Tokyo | Hirayama F.,Kyushu University | And 3 more authors.
The Lancet | Year: 2013

Background: Macrosomia is a risk factor for adverse delivery outcomes. We investigated the prevalence, risk factors, and delivery outcomes of babies with macrosomia in 23 developing countries in Africa, Asia, and Latin America. Methods: We analysed data from WHO's Global Survey on Maternal and Perinatal Health, which was a facility-based cross-sectional study that obtained data for women giving birth in 373 health facilities in 24 countries in Africa and Latin America in 2004-05, and in Asia in 2007-08. Facilities were selected by stratified multistage cluster sampling and women were recruited at admission for delivery. We extracted data from the medical records with a standardised questionnaire. We used logistic regression with random effects to assess the risk factors for macrosomia and the risks for caesarean section and adverse maternal and perinatal outcomes (assessed by a composite score) in babies with the disorder. Findings: Of 290 610 deliveries, we analysed data for 276 436 singleton livebirths or fresh stillbirths. Higher maternal age (20-34 years), height, parity, body-mass index, and presence of diabetes, post-term pregnancy, and male fetal sex were associated with a significantly increased risk of macrosomia. Macrosomia was associated with an increased risk of caesarean section because of obstructed labour and post-term pregnancy in all regions. Additionally, macrosomia was associated with an increased risk of adverse maternal birth outcomes in all regions, and of adverse perinatal outcomes only in Africa. Interpretation: Increasing prevalence of diabetes and obesity in women of reproductive age in developing countries could be associated with a parallel increase in macrosomic births. The effect and feasibility of control of diabetes and preconception weight on macrosomia should be investigated in these settings. Furthermore, increased institutional delivery in countries where rates are low could be crucial to reduce macrosomia-associated morbidity and mortality. Funding: None. © 2013 Elsevier Ltd. Source

Kishi T.,Kyushu University
Journal of Cardiology | Year: 2012

In heart failure, it has been recognized that the sympathetic nervous system (SNS) is activated and the imbalance of the activity of the SNS and vagal activity interaction occurs. The abnormal activation of the SNS leads to further worsening of heart failure. Many previous clinical and basic studies have demonstrated that the abnormal activation of the SNS is caused by the enhancement of excitatory inputs including changes in: (1) peripheral baroreceptor and chemoreceptor reflexes; (2) chemical mediators that control sympathetic outflow; and (3) central sites that integrate sympathetic outflow. In particular, the abnormalities in central SNS regulation due to the renin angiotensin system-oxidative stress axis have recently been in focus. In the treatment of heart failure, the inhibition of the activated SNS, such as with beta-blockers and/or exercise training, is important. Furthermore, many experimental studies have demonstrated that vagal stimulation has beneficial effects on heart failure, and recently several clinical studies have also demonstrated that vagal stimulation is a possible novel therapy for heart failure. In conclusion, we must recognize that heart failure is a complex syndrome with an autonomic nervous system dysfunction, and that the autonomic imbalance with the activation of the SNS and the reduction of vagal activity should be treated. © 2012 Japanese College of Cardiology. Source

Omura T.,Kyushu University
Biotechnology and Applied Biochemistry | Year: 2013

Emergence of eukaryotic cells in the ancient world of prokaryotic life was dependent on P450 as the synthesis of sterols, an essential constituent of the plasma membrane, required a P450-catalyzed reaction. As the ancestral monocellular eukaryotic organisms evolved into multicellular eukaryotes, and then diversified to plants, fungi, and animals with different body organizations and metabolic activities, many novel compounds were created in order to meet the requirements for increasing complex metabolic activities of a wide variety of eukaryotic organisms. Many new P450s, created by gene duplication and mutation, contributed to the synthesis of those novel compounds in animals, plants, and fungi, and supported the diversification of the eukaryotes. Many secondary metabolites of plants, which protect the plants from the predation by herbivorous animals, were also synthesized by P450-catalyzed reactions. The herbivorous animals detoxified the noxious foreign compounds in the plants by P450. This "chemical warfare" between animals and plants is particularly evident in plants-insects interaction, and contributed to the coevolution and diversification of both plants and insects. The interaction between flowering plants and insect pollinators, which contributed to their coevolution, also depends on various plant compounds synthesized by P450-catalyzed reactions. P450 has made highly important contributions to the evolution and diversification of eukaryotic organisms. © 2013 International Union of Biochemistry and Molecular Biology, Inc. Source

Ichinose H.,Kyushu University
Biotechnology and Applied Biochemistry | Year: 2013

Wood-rotting basidiomycetes possess superior metabolic functions to degrade woody biomass, and these activities are indispensable for the carbon cycle of the biosphere. As well as basic studies of the biochemistry of basidiomycetes, many researchers have been focusing on utilizing basidiomycetes and/or their enzymes in the biotechnology sector; therefore, the unique activities of their extracellular and intracellular enzymes have been widely demonstrated. A rich history of applied study has established that basidiomycetes are capable of metabolizing a series of endogeneous and exogeneous compounds using cytochrome P450s (P450s). Recently, whole genome sequence analyses have revealed large-scale divergences in basidiomycetous P450s. The tremendous variation in P450s implies that basidiomycetes have vigorously diversified monooxygenase functions to acquire metabolic adaptations such as lignin degradation, secondary metabolite production, and xenobiotics detoxification. However, fungal P450s discovered from genome projects are often categorized into novel families and subfamilies, making it difficult to predict catalytic functions by sequence comparison. Experimental screening therefore remains essential to elucidate the catalytic potential of individual P450s, even in this postgenomic era. This paper archives the known metabolic capabilities of basidiomycetes, focusing on their P450s, outlines the molecular diversity of basidiomycetous P450s, and introduces new functions revealed by functionomic studies using a recently developed, rapid, functional screening system. © 2013 International Union of Biochemistry and Molecular Biology, Inc. Source

Eocorythoderus incredibilis, a new genus and new species, of Corythoderini is described. This new species was found in fungus gardens of Macrotermes gilvus (Hagen, 1858) in Angkor Wat, Cambodia. The new taxon is a flightless, microphthalmic species and the first corythoderine associated with Macrotermes Holmgren, 1910. The beetles were observed being carried by worker termites. Eocorythoderus is probably closely related to the genera Corythoderus Klug, 1845 and Paracorythoderus Wasmann, 1918 (also Corythoderini). Some character states shared with the distantly-related termitophilous scarab genus Termitotrox Reichensperger, 1915 (Termitotrogini) are noted, and proposed as convergent. Copyright © 2012 · Magnolia Press. Source

A number of insect species infest human households and stored foods and products, leading to their designation as pests. Until recently, little was known about the factors driving the evolution of pests that feed on stored dry foods. Here, I review the effects of changes in climate and species interactions on the evolution and ecology of beetles that feed on dried seeds/grains. My review focuses on evidence that the host utilization by part of the species in the subfamily Bruchinae (Chrysomelidae) is a preadaptation for utilizing stored dry seeds and grains, thus leading to their status as a pest. These and other stored product pest beetles retain a higher percentage of water in their body, relative to the water content of their diet, than beetles that feed on fresh crops. I review the studies that have documented adaptation, acclimation and polyphenetic response to high temperatures and desiccation and/or made direct comparisons between these traits between developmental stages, populations and among higher taxonomic groups. Finally, I review evidence for the effects of environmental change on insect host-parasitoid and competitor assemblages. © 2010 Cambridge University Press. Source

Takaki S.,Kyushu University
Materials Science Forum | Year: 2010

Yielding of polycrystalline low carbon steel is characterized by a clear yield point followed by unstable Lüders deformation and such a yielding behavior is taken over to fine grained steel with the grain size of 1μm or less. Yield strength of ferritic steel is increased with grain refinement standing on the Hall-Petch relation. The following equation is realized up to 0.2μm grain size in the relation between yield strength σy and grain size d: σy [MPa]= 100+600×d[μm] -1/2. In low carbon steel, it might be concluded that the Hall-Petch coefficient (ky) is around 600MPa·μm1/2. However, the ky value of interstitial free steels is substantially small as 130-180MPa·μm1/2 and it can be greatly increased by a small amount of solute carbon less than 20ppm. It was also cleared that the disappearance of yield point by purifying is due to the decrease in the k y value. On the other hand, the ky value is changeable depending on heat treatment conditions such as cooling condition from an elevated temperature and aging treatment at 90°C. These results suggest the contribution of carbon segregation at grain boundary in terms of the change in the ky value. On the contrary, substitutional elements such as Cr and Si do not give large influence to the ky value in comparison with the effect by carbon. © (2010) Trans Tech Publications. Source

In undamaged postnatal muscle fibers with normal contraction and relaxation activities, quiescent satellite cells of resident myogenic stem cells are interposed between the overlying external lamina and the sarcolemma of a subjacent mature muscle fiber. When muscle is injured, exercised, overused or mechanically stretched, these cells are activated to enter the cell proliferation cycle, divide, differentiate, and fuse with the adjacent muscle fiber, and are responsible for regeneration and work-induced hypertrophy of muscle fibers. Therefore, a mechanism must exist to translate mechanical changes in muscle tissue into chemical signals that can activate satellite cells. Recent studies of satellite cells or single muscle fibers in culture and in vivo demonstrated the essential role of hepatocyte growth factor (HGF) and nitric oxide (NO) radical in the activation pathway. These experiments have also reported that mechanically stretching satellite cells or living skeletal muscles triggers the activation by rapid release of HGF from its extracellular tethering and the subsequent presentation to the receptor c-met. HGF release has been shown to rely on calcium-calmodulin formation and NO radical production in satellite cells and/or muscle fibers in response to the mechanical perturbation, and depend on the subsequent up-regulation of matrix metalloproteinase (MMP) activity. These results indicate that the activation mechanism is a cascade of events including calcium ion influx, calcium-calmodulin formation, NO synthase activation, NO radical production, MMP activation, HGF release and binding to c-met. Better understanding of 'mechano-biology' on the satellite cell activation is essential for designing procedures that could enhance muscle growth and repair activities in meat-animal agriculture and also in neuromuscular disease and aging in humans. © 2009 The Author. Journal compilation © 2009 Japanese Society of Animal Science. Source

Van Muiswinkel W.B.,Wageningen University | Nakao M.,Kyushu University
Developmental and Comparative Immunology | Year: 2014

This review describes the history of research on immunity to infectious diseases of fish in the period between 1965 and today. Special attention is paid to those studies, which are dealing with the interaction between immune system and invading pathogens in bony fish. Moreover, additional biographic information will be provided of people involved. In the 1960s and 1970s the focus of most studies was on humoral (Ig, B-cell) responses. Thorough studies on specific cellular (T-cell) responses and innate immunity (lectins, lysozyme, interferon, phagocytic cells) became available later. In the period between 1980 and today an overwhelming amount of data on regulation (e.g. cell cooperation, cytokines) and cell surface receptors (e.g. T-cell receptor; MHC) was published. It became also clear, that innate responses were often interacting with the acquired immune responses. Fish turned out to be vertebrates like all others with a sophisticated immune system showing specificity and memory. These basic data on the immune system could be applied in vaccination or in selection of disease resistant fish. Successful vaccines against bacterial diseases became available in the 1970s and 1980s. Effective anti-viral vaccines appeared from the 1980s onwards. There is no doubt, that Fish Immunology has become a flourishing science by the end of the 20th century and has contributed to our understanding of fish diseases as well as the success of aquaculture. © 2013 Elsevier Ltd. Source

Somamoto T.,Kyushu University | Koppang E.O.,Institute of Basic science and Aquatic Medicine | Fischer U.,Friedrich Loeffler Institute
Developmental and Comparative Immunology | Year: 2014

Cytotoxic T-cells (CTLs) play a pivotal role in eliminating viruses in mammalian adaptive immune system. Many recent studies on T-cell immunity of fish have suggested that teleost CTLs are also important for antiviral immunity. Cellular functional studies using clonal ginbuan crucian carp and rainbow trout have provided in vivo and in vitro evidence that in many respects, virus-specific CTLs of fish have functions similar to those of mammalian CTLs. In addition, mRNA expression profiles of CTL-related molecules, such as CD8, TCR and MHC class I, have shown that in a wide range of fish species, CTLs are involved in antiviral adaptive immunity. These findings are a basis to formulate possible vaccination strategies to trigger effective antiviral CTL responses in teleost fish. This review describes recent advances in our understanding of antiviral CTL functions in teleost fish and discusses vaccination strategies for efficiently inducing CTL activities. © 2013 Elsevier Ltd. Source

Kikkawa Y.,Kyushu University
Acta Neurochirurgica, Supplementum | Year: 2014

In recent years, the shift of research interest in the pathological condition after subarachnoid hemorrhage (SAH) from delayed cerebral vasospasm to early brain injury and the development of molecular genetic approaches in animal experiments has resulted in a diversification of animal SAH models. The properties of each animal SAH model thus need to be validated and the purpose of using each animal model should be clarified. This study presents the settings and technical procedures for a rabbit cisterna magna double-injection SAH model and discusses the advantages and limitations of using this model. © Springer International Publishing Switzerland 2015. Source

Shimojo M.,Kyushu University
Journal of the Faculty of Agriculture, Kyushu University | Year: 2011

This study was designed to investigate the symmetry in motion in Euler's formula and its breakdown in hyperbolic function and growth function. The results obtained were as follows. (1) The symmetry in motion between θ and exp(iθ) was shown when θ was kept in motion. The symmetry breakdown in motion between θ and cosh(θ), between θ and sinh(θ), and between θ and exp(θ) was shown when θ was kept in motion. (2) There were some properties that were common to these three functions. (3) If hyperbolic function related exponential function with Lorentz transformation, then the Bondi-k factor was an exponential function. (4) Mathematical relationships between the Bondi-k factor and the imaginary unit were suggested. (5) Mathematical relationships between Euler's formula and growth function were discussed by relating qualitative differences in complex numbers with quantitative differences in real numbers. It was suggested that the breakdown of symmetry in motion in Euler's formula gave hyperbolic function and growth function, where some properties common to these three functions were also observed. Source

Sugikawa K.,Hokkaido University | Sugikawa K.,Kyushu University | Furukawa Y.,Hokkaido University | Sada K.,Hokkaido University
Chemistry of Materials | Year: 2011

The functional metala organic frameworks (MOFs) showing surface-enhanced Raman scattering (SERS) activity were fabricated by embedding 11-mercaptoundecanoic acid-capped AuNRs gold nanorods (AuNRs) into [Zn 4O(bpdc) 3]; bpdc = 4,4-biphenyl dicarboxylate. The resulting purple cubic MOF crystals enabled us to investigate the existence and exchange of guest molecules in the nanopore of the MOF crystals by SERS spectra. © 2011 American Chemical Society. Source

Horisawa K.,Kyushu University
Frontiers in Physiology | Year: 2014

Specific and highly efficient fluorescent labeling techniques for biomolecules, especially for proteins, are required for the quantitative analyses of bio-phenomena and for subsequent systems biology. Although expression of exogenous proteins fused with fluorescent tags, such as green fluorescent protein, is the most widely used method for quantitative bio-analysis, the following problems need to be considered carefully: (1) precise stoichiometric control in living cells is difficult, and (2) the bulkiness of the fluorescent tags restricts analysis of the inherent physical and biological properties of the proteins. Therefore, novel techniques to specifically and stoichiometrically label intrinsic proteins or other biomolecules in living cells should be developed. Click chemistry reactions (e.g., Huisgen cycloaddition and Staudinger ligation) are the most promising approaches for this purpose, because these chemical reactions have following advantages: (1) bioorthogonal reactions; (2) mild reaction conditions suitable for fragile biomolecules, cells, and tissues; (3) extremely high reaction ratio; (4) small size of the functional groups for the cross-coupling reactions; (5) stable covalent bonding; and (6) simple metabolic labeling procedures in living cells, using various biomolecular analogs. Diverse quantitative biological studies have been carried out using this technology (e.g., quantification of novel synthesized proteins and observation of post-translational modifications). In this review, I explain the basics of chemical probing with click chemistry, and discuss its recent applications in the field of quantitative biology. Furthermore, I discuss the capability, significance, and future of the chemical probing of proteins, with an emphasis on the use of click chemistry in the field of the quantitative biology. © 2014 Horisawa. Source

A circular object placed in the centre of a radial pattern consisting of thin sectors was found to cause a robust motion illusion. During eye-movement pursuit of a moving target, the presently described stimulus produced illusory background-object motion in the same direction as that of the eye movement. In addition, the display induced illusory stationary perception of a moving object against the whole display motion. In seven experiments, the characteristics of the illusion were examined in terms of luminance relationships and figural characteristics of the radial pattern. Some potential explanations for these findings are discussed. © 2012 H Ito. Source

Fujishima S.-H.,Kyoto University | Yasui R.,Kyoto University | Miki T.,Kyoto University | Ojida A.,Kyushu University | Hamachi I.,Kyoto University
Journal of the American Chemical Society | Year: 2012

Chemistry-based protein labeling in living cells is undoubtedly useful for understanding natural protein functions and for biological/pharmaceutical applications. Here, we report a novel approach for endogenous membrane-bound protein labeling for both in vitro and live cell conditions. A moderately reactive alkyloxyacyl imidazole (AI) assisted by ligand-binding affinity (ligand-directed AI (LDAI)) chemistry allowed us to selectively modify natural proteins, such as dihydrofolate reductase (DHFR) and folate receptor (FR), neither of which could be efficiently labeled using the recently developed ligand-directed tosylate approach. It was clear that LDAI selectively labeled a single Lys(K32) in DHFR, proximal to the ligand-binding pocket. We also demonstrate that the fluorescein-labeled (endogenous, by LDAI) FR works as a fluorescent biosensor on the live KB cell surface, which allowed us to carry out unprecedented in situ kinetic analysis of ligand binding to FR. © 2012 American Chemical Society. Source

Okamura M.,Kyushu University
Journal of Fluid Mechanics | Year: 2010

We investigate the properties of almost limiting short-crested gravity waves with harmonic resonance for various incident angles. When the incident angle is less than 47.5°, the enclosed crest angle in non-resonant limiting waves is 90°, which corresponds to that in standing waves. In contrast, when the incident angle exceeds 47.5°, the enclosed crest angle in non-resonant limiting waves is 120°, which corresponds to that in two-dimensional progressive waves. The enclosed crest angle is 90° in resonant limiting waves for all incident angles. The crest becomes flatter than the trough in resonant limiting waves if the fundamental mode has a different sign from its harmonic resonant mode. Bifurcation of short-crested waves is also investigated. Copyright © Cambridge University Press 2010. Source

Nagata T.,Kyushu University
Prehospital and disaster medicine | Year: 2013

Following the Great East Japan Earthquake on March 11, 2011, the Japan Medical Association deployed medical disaster teams to Shinchi-town (population: approximately 8,000), which is located 50 km north of the Fukushima Daiichi nuclear power plant. The mission of the medical disaster teams sent from Fukuoka, 1,400 km south of Fukushima, was to provide medical services and staff a temporary clinic for six weeks. Fear of radiation exposure restricted the use of large medical teams and local infrastructure. Therefore, small volunteer groups and a cloud-hosted, web-based electronic health record were implemented. The mission was successfully completed by the end of May 2011. Cloud-based electronic health records deployed using a "software as a service" model worked well during the response to the large-scale disaster. Source

Kitahara M.T.,Kyushu University
Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B | Year: 2010

Polymer electrolyte fuel cells (PEFCs) generally have external humidifiers to supply humidified hydrogen and oxidant gases. If a PEFC could be operated under no-humidification, humidifiers may be removed, resulting in a simplified PEFC system with increased total efficiency and reduced cost. The present study was carried out to clarify the influence of gas diffusion layers (GDLs) on PEFC performance under no-humidification using anode gas recirculation. For the anode GDL, it is important to increase water transport between the anode gas and the membrane electrode assembly (MEA). The anode GDL without a microporous layer (MPL) is effective for enhancing PEFC performance. For the cathode GDL, it is important to maintain humidity and prevent drying-up of the MEA. A double hydrophobic MPL coated on both sides of the GDL is effective for reducing gas permeability, thereby preventing removing the water in the MEA through the GDL via dry air at the cathode. The hydrophilic layer coated on the double MPL enhances the ability of the GDL to prevent drying-up. Appropriate hydrophilic layer thickness of 40 μm is effective for enhancing PEFC performance. Reducing the pore diameter of the hydrophobic intermediate layer between the hydrophilic layer and the substrate is also effective for enhancing PEFC performance. Source

Shimojo M.,Kyushu University
Journal of the Faculty of Agriculture, Kyushu University | Year: 2011

The growth of a plant or an animal is analyzed using the exponential function. This study was designed to investigate mathematical properties of the exponential function using relationships between the exponential function, the Bondi K-factor and the imaginary unit. The results obtained were as follows. The exponential function was equal to the Bondi K-factor. When the Bondi K-factor took the value greater than 1, there occurred an exponential increase. This implied an association with the phenomenon that ingesting energy and substances from the environment caused the increase in size and weight of a plant or an animal. The mathematical operation of v →∞ caused the collapse of the Bondi K-factor into the imaginary unit. This collapse left a gap between the imaginary unit and the exponential function. There was also a discussion on the relationship between the object with the Bondi K-factor and the wave function described using complex numbers. It was suggested that mathematical properties of the exponential function were related to those of the Bondi K-factor. Source

Nishimura T.,Kyushu University
Journal of physiological anthropology | Year: 2012

The purpose of this study was to elucidate the interaction between mtDNA haplogroup and seasonal variation that contributes to cold adaptation. There were 15 subjects (seven haplotype D subjects and eight haplotype non-D subjects). In summer and winter, the subjects were placed in an environment where the ambient temperature dropped from 27 °C to 10 °C in 30 minutes. After that, they were exposed to cold for 60 minutes. In summer, the decrease in rectal temperature and increase in oxygen consumption was smaller and cold tolerance was higher in the haplotype non-D group than in the haplotype D group. In winter, no significant differences were seen in rectal temperature or oxygen consumption, but the respiratory exchange ratio decreased in the haplotype D group. The results of the present study suggest that haplogroup D subjects are a group that changes energy metabolism more, and there appears to be a relationship between differences in cold adaptability and mtDNA polymorphism within the population. Moreover, group differences in cold adaptability seen in summer may decrease in winter due to supplementation by seasonal cold acclimatization. Source

Lesur M.,Kyushu University
Physics of Plasmas | Year: 2013

In the presence of an energetic particle population in a dissipative plasma, self-trapped structures in phase-space (holes and clumps) emerge from nonlinear wave-particle interactions. Their dynamics can lead to a nonlinear continuous shifting of the wave frequency (chirping). The effects of collisions on chirping characteristics are investigated, with a one-dimensional kinetic model. Existing analytic theory is extended to account for Krook-like collisions, which quantitatively explains a significant departure from widely accepted square-root time dependency. Relaxation oscillations, associated with chirping bursts, are investigated in the presence of dynamical friction and velocity-diffusion. The period increases with decreasing drag and weakly increases with decreasing diffusion. The mechanism is clarified with a simple semi-analytic model of hole/clump pair, which satisfies a Fokker-Planck equation. The model shows that the linear growth rate cannot be obtained simply by fitting an exponential to the amplitude time-series. © 2013 AIP Publishing LLC. Source

This review addresses the design and synthesis of synthetic glycopolymers. Glycopolymers with pendant saccharides exhibit high affinities for proteins owing to their multivalency. Glycopolymers have molecular recognition abilities and amphiphilicity and can be applied as biomaterials and in bioassays. Most synthetic glycopolymers are prepared from polymerizable saccharide derivatives, and the rest are prepared by saccharide addition to a polymer backbone. Because sugar-recognizing proteins have precise structures, the living polymerization of glycopolymers is important in the fabrication of well-defined multiple ligands of saccharides. Glycopolymers with narrow polydispersity are useful for determining the interactions between saccharides and proteins. The living polymerization of glycopolymers provides hybrid materials by the terminal modification of the polymers. The glycopolymers of block polymers, star polymers and polymer brushes have been investigated for use in novel biomaterials. © 2012 The Society of Polymer Science, Japan (SPSJ). Source

Ash P.A.,Durham University | Bain C.D.,Durham University | Matsubara H.,Kyushu University
Current Opinion in Colloid and Interface Science | Year: 2012

The behaviour of oils at aqueous interfaces is ubiquitous to many industrially and biologically relevant processes. In this review we consider modifications to the wetting properties of oils at the air/water, oil/water and solid/liquid interfaces in the presence of surfactants. First-order wetting transitions can be induced in a wide range of oils by varying the aqueous surfactant concentration, leading to the formation of mixed monolayers at the interface. In certain cases, these mixed monolayers display novel surface freezing behaviour, including the formation of unusual bilayer structures, which further modifies the properties of the interface. The effects of surfactant on line tension at the three-phase contact line and differences between the air/liquid and liquid/liquid interfaces are discussed. © 2012 Elsevier Ltd. Source

Fungal contaminations in indoor environment are recognized as one of the serious problem in terms of health and aesthetic impact. Large numbers of studies have shown an association between the health risk of fungal contamination. Residence in houses and fungal growth is well known to be strongly related to various indoor environmental parameters and hence the development of a comprehensive prediction method for fungal contamination is needed for healthy indoor environmental design. This research focused on the fungal growth problems in residential bathroom where the temperature and humidity can become relatively high. This paper reports the procedure and results of numerical simulations of fungal contamination. The simulation was incorporated with flow field, temperature/humidity distribution, which was used to predict fungal spore dispersion/deposition in bathroom space and subsequent non-uniform distribution of fungal growth on wall surfaces. Fungal spores transportation was analyzed by Lagrangean approach. For fungal growth phenomenon, the reaction-diffusion model that reproduces morphological colony formation of fungi was adopted. By continuously executing these numerical analyses, fungal spore deposition and subsequent fungal growth on wall surfaces was demonstrated for two targeted representative ventilation rate in normal bathroom condition. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. Source

Jandieri V.,Kyungpook National University | Yasumoto K.,Kyushu University
IEEE Transactions on Antennas and Propagation | Year: 2011

A semi-analytical approach for analyzing two-dimensional electromagnetic scattering by layered cylindrical arrays of circular rods periodically distributed along concentrically layered circular rings is presented. The method uses the T-matrix of a circular rod in isolation, the reflection and transmission matrices of a cylindrical array expressed in terms of the cylindrical harmonic waves as the basis and the generalized reflection and transmission matrices for a layered cylindrical structure. Using the method, the scattering of plane waves impinging on the cylindrical arrays from the exterior region and the radiation from a line source located inside the cylindrical arrays are numerically investigated. Numerical examples demonstrate that the layered cylindrical arrays are effective for forming a directed beam in the scattered and radiated fields. © 2006 IEEE. Source

Kuwano R.,Kyushu University
Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry | Year: 2011

This account describes our recent work on catalytic cross-coupling reactions using carboxylate and carbonate leaving groups in the electrophilic substrate. Some bisphosphine-chelated palladium(O) complexes are effective for the cleavage of benzylic C-O bonds in benzyl carbonates and acetates. This C-O bond cleavage was utilized in catalytic reactions of these benzylic esters; the nucleophilic benzylic substitutions and the crosscoupling reactions with organometallic compounds. Furthermore, vinyl acetate was proved to work as the coupling partner of arylboronates in the presence of [RhCl(cod)] 2-DPPB. Interestingly, the organoborons react selectively at the position β to the leaving group in the alkenyl ester when the rhodium-catalyzed reaction is conducted in the absence of the bisphosphine. Source

Sasada I.,Kyushu University
Journal of Applied Physics | Year: 2012

This study analyzes the steady state behavior of wireless power transfer through the magnetic coupling between two LC-resonators that consist of a loop coil (diameter 0.2 m) and a terminating capacitor based on an equivalent circuit model. Parameters considered include the quality factor Q of resonators and the distances between coils, which govern the strength of the magnetic coupling and the frequency of the sinusoidal power source (24 ∼ 28 kHz range). The efficiency and amount of power transferred are calculated under the optimum load for the distance of transfer. The analysis proves that with a moderately high Q of 227, the efficiency can reach above 85 at the distance equal to the radius of the resonant coil, when the load is optimized. An important finding from the analysis is that there is a value for the frequency where the optimum load is almost unchanged, even when the distance between two resonators changes. © 2012 American Institute of Physics. Source

We demonstrate a new optical bistability devise by using two Fiber Bragg Gratings (FBG), in which an erbium-doped fiber (EDF) is inserted to form a nonlinear Fabry-Perot cavity (EDF FBG/F-P). The operation principle of this device is described by the resonant nonlinearity theory combining with the transfer matrix method. The optical bistability behaviors under different parameters are investigated. It shows that EDF FBG/F-P device has an evident merit in reducing the threshold switching power to 7 mW, resulting in a reduction about 6 orders, compared with that of single FBG device. Moreover, the ultra-fast response time about 35 ps is also confirmed. © 2011 Elsevier B.V. All rights reserved. Source

The salt effect on complex formation of poly(acrylamide)-block-poly(acrylic acid) (PAM-b-PAA) and dodecyltrimethylammonium bromide (DTAB) at different NaBr concentrations, C NaBr, was investigated by laser light scattering (LLS) and small angle neutron scattering (SANS). LLS and SANS clearly indicates that the aqueous solution of PAM-b-PAA and DTAB associate into colloidal complexes. For low surfactant-to-polymer charge ratio Z lower than the critical value Z C, the colloidal complexes are single DTAB micelles dressed by a few PAM-b-PAA. Above Z C, the colloidal complexes form a core-shell microstructure. The complex formation in the PAM-b-PAA/DTAB is enhanced by addition of salt: Z C decreases with increasing C NaBr. This is considered to similar to the cmc behavior for the pure surfactant system. The core of the complex consists of densely packed surfactant micelles (DTA +), and PAA block chains bind to these micelles, displace their counteranions (Br-) and bridge them. The corona of the complex is constituted from the PAM. Since the interaction between polyelectrolyte and oppositely charged surfactant is primarily electrostatic in nature, the core radius and the intermicellar distance of the DTA + micelles inside the core depend on C NaBr. The addition of salt screens the electrostatic attraction between oppositely charged PAA block and DTAB, which weakens the interaction. With increasing C NaBr, therefore, the core of the colloidal complex is considered to swell, which leads to the increases in the core radius R C and the intermicellar distance of the DTA + micelles inside the core. The aggregation number expressed in terms of DTA + micelles per complex is also evaluated using the analogy with the homopolyelectrolyte/surfactant system. © 2011 Elsevier B.V. Source

We propose a novel population-based optimization algorithm, Chaotic Evolution (CE), which uses ergodic property of chaos to implement exploration and exploitation functions of an evolutionary algorithm. CE introduces a mathematical mechanism into an iterative process of evolution and simulates ergodic motion in a search space with a simple principle. A control parameter, direction factor rate, is proposed to guide search direction in CE. It is easy to extend its search capability by using different chaotic system in CE algorithm framework. The scalability of CE is higher than that of some other evolutionary computation algorithms. A series of comparative evaluations and investigations is conducted to analyse characteristics of the proposal. Our proposal can obtain better optimization performance by comparing with differential evolution and some of its variants. We point out that the chaos theory is used not only to describe and explain a non-linear system, but also to implement a variety of optimization algorithms based on its ergodic property. © 2014 Springer Science+Business Media Dordrecht. Source

Melittin, a peptide of 26 amino acid residues, has been used as a model peptide for protein folding and unfolding, and extensive research has been done into its structure and conformational stability. Circular dichroism (CD) studies have demonstrated that melittin in an aqueous solution undergoes a transition froma helical tetramer to a randomcoil monomer not only by heating but also by cooling from room temperature (i.e., heat- and cold-denaturation, respectively). The heat-denaturation has been also examined by nuclear magnetic resonance (NMR) experiments, however, no NMR data have been presented on the cold-denaturation. In this paper, using proton ( 1H) NMR spectroscopy, we show that melittin undergoes conformational transitions from the monomer to the tetramer to the monomer by elevating temperature from 2 to 70 °C. Only melittin including a trans proline peptide bond participates in the transitions, whereas melittin including a cis proline one does not. The tetramer has maximum conformation stability at around 20 °C, and cooperativity of the heat-denaturation is extremely low. © European Biophysical Societies' Association 2012. Source

In mammalian genomic DNA, cytosine methylation predominantly occurs at CpG dinucleotides and provides epigenetic information. In some cells, 5-methyl-cytosine (5-mC) can be further converted to 5-hydroxymethyl-cytosine (5-hmC) by the ten-eleven translocation family of proteins. MspI restriction endonuclease has been used to analyze these modifed cytosines. However, the kinetic analysis in this study revealed that MspI activity is dramatically decreased by symmetrical hydroxymethylation of its recognition sequence and partly inhibited by hemi-hydroxymethylation, whereas TaqI and HaeIII are relatively resistant to hydroxymethylation. Therefore, DNA modification studies that use MspI, for example, reduced representation bisulfite shotgun sequencing, quantitative analysis of 5-hmC and cleavage-sensitivity analysis, should be carefully interpreted. © 2012 Landes Bioscience. Source

Kira J.-I.,Kyushu University
Multiple Sclerosis and Related Disorders | Year: 2012

There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as opticospinal (OSMS) and conventional (CMS) forms. In Japan, the results of four nationwide surveys of MS conducted between 1972 and 2004 have revealed a four-fold increase in the estimated number of clinically definite MS patients in 2003 compared with 197