著者

Lee J. D. Gomi H. Hase Muneaki

出版者

American Institute of Physics

雑誌

Journal of applied physics (ISSN:00218979)

巻号頁・発行日

vol.106, no.8, pp.083501, 2009-10-16

被引用文献数

1 3

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Using the nonperturbative many-body time-dependent approach, we investigate the nonequilibrium dynamics of the coherent longitudinal optical phonon-plasmon coupled (LOPC) modes in a polar semiconductor and explore their coherent optical control and eventually the carrier mobility of the semiconductor. The basic idea for a control of the carrier mobility is to manipulate the ultrafast dephasing of the coherent carrier-relevant LOPC mode. We theoretically propose two possible options to realize the idea and reach the final goal. One is to optimize a semiconductor by finely balancing two kinds of carrier densities by chemical doping and optical doping (or photodoping), where the relaxation of the coherent carrier-relevant LOPC mode would respond in a (weak) singular way. It is found that, in this way, the carrier mobility could be enhanced by a few tens of percent. The other is to optimize the optical pumping laser. In this option, the pulse train creating pure virtual carriers through the below-band-gap excitation would be incorporated for an optical pumping, which can make possible the dephasing-free dynamics of the coherent carrier-relevant LOPC mode. The carrier mobility can then be efficiently controlled and dramatically enhanced by synchronizing the pulse train with its coherent oscillation. This might imply one of ultimate ways to control the carrier mobility of the semiconductor

著者

Ide T Isozaki H Nakata S Siltanen S

出版者

Institute of Physics

雑誌

Inverse problems (ISSN:02665611)

巻号頁・発行日

vol.26, no.3, pp.035001, 2010-03

被引用文献数

12 12

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Assume one is given a three-dimensional bounded domain with an unknown conductivity distribution inside. Further, suppose that the conductivity consists of a known background and unknown anomalous regions (inclusions) where conductivity values are unknown and different from the background. A method is introduced in Ide et al (2007 Commun. Pure Appl. Math. 60 1415–42) for locating inclusions approximately from noisy localized voltage-to-current measurements performed at the boundary of the body. The method is based on the use of complex geometrical optics solutions and hyperbolic geometry; numerical testing is presented in the aforementioned paper for the two-dimensional case. This work reports the results of computational implementation of the method in dimension three, where both the simulation of data and the computerized inversion algorithm are more complicated than in dimension two. Three new regularizing steps are added to the algorithm, resulting in significantly better robustness against noise. Numerical experiments are reported, suggesting that the approximate location of the inclusions can be reliably recovered from the data with a realistic level of measurement noise. Potential applications of the results include early diagnosis of breast cancer, underground contaminant detection and nondestructive testing.

著者

Kinoshita Setsuko Wagatsuma Yukiko Okada Masafumi

出版者

BioMed Central

雑誌

International journal of health geographics

巻号頁・発行日

vol.6, pp.34, 2007-07

被引用文献数

28 30

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BackgroundMalignant neoplasm of the pancreas has become one of the leading causes of death from malignant neoplasm in Japan (the 5th in 2003). Although smoking is believed to be a risk factor, other risk factors remain unclear. Mortality from malignant neoplasm of the pancreas tends to be higher in northern Japan and in northern European countries. A recent study reported that standardized mortality ratios (SMRs) for malignant neoplasm of the pancreas were negatively correlated to global solar radiation level. People residing in regions with lower solar radiation and lower temperatures may be at higher risk of development of malignant neoplasm of the pancreas. Therefore, this study aimed to examine the relationship between SMRs for malignant neoplasm of the pancreas and climatic factors, such as the amount of global solar radiation and the daily maximum temperature in Japan.ResultsThe study used multiple linear regression models. Number of deaths and demographic data from 1998 to 2002 were used for the calculation of SMR. We employed mesh climatic data for Japan published in 2006 by the Japan Meteorological Agency. Regression coefficients for the amount of global solar radiation and the daily maximum temperature in males were -4.35 (p = 0.00034) and -2.81 (p < 0.0001) respectively, and those in females were -5.02 (p < 0.0001) and -1.87 (p < 0.0001) respectively. Increased amount of global solar radiation or daily maximum temperature was significantly related to the decreased SMRs for malignant neoplasm of the pancreas in both males and females.ConclusionThis study suggested that low solar radiation and low temperature might relate to the increasing risk of malignant neoplasm of the pancreas. Use of group data has a limitation in the case of evaluating environmental factors affecting health, since the impact of climatic factors on the human body varies according to individual lifestyles and occupations. Use of geographical mesh climatic data, however, proved useful as an index of risk or beneficial factors in a small study area. Further research using individual data is necessary to elucidate the relationship between climatic factors and the development of malignant neoplasm of the pancreas.

著者

Otani Minoru Takagi Yoshiteru Koshino Mikito Okada Susumu

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.96, no.24, pp.242504, 2010-06

被引用文献数

25

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Based on first-principle total-energy calculations, we have found that by applying an external electric field it is possible to control the magnetic state of graphite thin film with the rhombohedral stacking arrangement. When exposed to a moderate electric field normal to the film, the surface of a thin film of rhombohedral graphite undergoes a magnetic phase transition from the antiferromagnetic state to the ferromagnetic state. The polarized electron spin is primarily distributed in the bottommost layer of the film, which forms the interface with the negative electrode. The amount of polarized electron spin is calculated to be 0.067 μB/nm2. The ferromagnetic ordering with the characteristic distribution of the polarized electron spin opens the possibility of using graphite thin films in electronic devices with spin degree of freedom.

著者

Iwanami Keiichi Matsumoto Isao Tanaka Yoko Inoue Asuka Goto Daisuke Ito Satoshi Tsutsumi Akito Sumida Takayuki

出版者

BioMed Central

雑誌

Arthritis research & therapy (ISSN:14786354)

巻号頁・発行日

vol.10, no.6, pp.R130, 2008-11

被引用文献数

31 21

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IntroductionArthritis induced by immunisation with glucose-6-phosphate isomerase (GPI) in DBA/1 mice was proven to be T helper (Th) 17 dependent. We undertook this study to identify GPI-specific T cell epitopes in DBA/1 mice (H-2q) and investigate the mechanisms of arthritis generation.MethodsFor epitope mapping, the binding motif of the major histocompatibility complex (MHC) class II (I-Aq) from DBA/1 mice was identified from the amino acid sequence of T cell epitopes and candidate peptides of T cell epitopes in GPI-induced arthritis were synthesised. Human GPI-primed CD4+ T cells and antigen-presenting cells (APCs) were co-cultured with each synthetic peptide and the cytokine production was measured by ELISA to identify the major epitopes. Synthetic peptides were immunised in DBA/1 mice to investigate whether arthritis could be induced by peptides. After immunisation with the major epitope, anti-interleukin (IL) 17 monoclonal antibody (mAb) was injected to monitor arthritis score. To investigate the mechanisms of arthritis induced by a major epitope, cross-reactivity to mouse GPI peptide was analysed by flow cytometry and anti-GPI antibodies were measured by ELISA. Deposition of anti-GPI antibodies on the cartilage surface was detected by immunohistology.ResultsWe selected 32 types of peptides as core sequences from the human GPI 558 amino acid sequence, which binds the binding motif, and synthesised 25 kinds of 20-mer peptides for screening, each containing the core sequence at its centre. By epitope mapping, human GPI325–339 was found to induce interferon (IFN) γ and IL-17 production most prominently. Immunisation with human GPI325–339 could induce polyarthritis similar to arthritis induced by human GPI protein, and administration of anti-IL-17 mAb significantly ameliorated arthritis (p < 0.01). Th17 cells primed with human GPI325–339 cross-reacted with mouse GPI325–339, and led B cells to produce anti-mouse GPI antibodies, which were deposited on cartilage surface.ConclusionsHuman GPI325–339 was identified as a major epitope in GPI-induced arthritis, and proved to have the potential to induce polyarthritis. Understanding the pathological mechanism of arthritis induced by an immune reaction to a single short peptide could help elucidate the pathogenic mechanisms of autoimmune arthritis.

著者

TAKATSUKA Tatsuyuki TAMAGAKI Ryozo

出版者

一般社団法人日本物理学会

雑誌

Progress of theoretical physics. Supplement (ISSN:03759687)

巻号頁・発行日

no.112, pp.27-65, 1993-06-20

被引用文献数

110

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Nucleon superfluids which are realized in neutron star interior and symmetric nuclear matter are studied with use of realistic nuclear forces, in the density domain from the subnuclear region to about 3ρ_0(ρ_0 being the nuclear density). It is shown that characteristic aspects of nuclear forces manifest themselves in the appearance of several kinds of nucleon superfluids, which strongly depends on the density ρ. In this chapter emphasis is put on the pairing correlations where strong noncentral (tensor and spin-orbit) forces play important roles. A theoretical framework applicable to the nonzero angular-momentum pairing including the coupling due to tensor force is given by extending the usual BCS-Bogoliubov theory for the ^<1>S_0 pairing (the zero angular-momentum one). This formulation has been applied to the ^<3>P_2+^<3>F_2 pairing in neutron matter (the dominant component of neutron stars) and the ^<3>S_1+^<3>D_1 pairing in symmetric nuclear matter. In the former case, although spin-orbit force mainly contributes to the ^<3>P_2 attraction, the tensor coupling with the ^<3>F_2 component assists to realize the ^<3>P_2 superfluid. In the latter case, the tensor coupling to the ^<3>D_1 component plays a vital role to realize the ^<3>S_1 superfluid with a large energy gap. Results of the energy gaps calculated for such nonzero angular-momentum pairings, as well as those for the ^<1>S_0 pairing, are shown. We have found the realization of the following nucleon superfluids; the neutron ^<3>P_2 superfluid and the proton ^<1>S_0 one in the fluid core of neutron stars at ρsime(0.7~3)ρ_0, the neutron ^<1>S_0 superfluid in the inner crust of neutron stars at ρsime(10^<-3>~0.5)ρ_0, and the ^<3>S_1 superfluid in symmetric nuclear matter at a wide range of ρ incliding ρ_0, contrary to the ^<1>S_0 one realized at ρIsim ρ_0/2. The properties of these superfluids and their implications are also discussed.

著者

Sakai Tomoko Matsui Mie Mikami Akichika Malkova Ludise Hamada Yuzuru Tomonaga Masaki Suzuki Juri Tanaka Masayuki Miyabe-Nishiwaki Takako Makishima Haruyuki Nakatsukasa Masato Matsuzawa Tetsuro

出版者

Royal Society Publishing

雑誌

Proceedings of the Royal Society B: Biological Sciences (ISSN:09628452)

巻号頁・発行日

vol.280, no.1753, 2013-02-22

被引用文献数

40

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世界で初めてチンパンジーの大脳の成長様式の解明に成功 : チンパンジーの脳成長からヒト知性の誕生の秘密に迫る. 京都大学プレスリリース. 2012-12-21.

著者

Yamamoto Shinya Humle Tatyana Tanaka Masayuki

出版者

National Academy of Sciences

雑誌

Proceedings of the National Academy of Sciences of the United States of America (ISSN:10916490)

巻号頁・発行日

2012-02-06

被引用文献数

150

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相手の状況に合わせたチンパンジーの手助け行動. 京都大学プレスリリース. 2012-02-07.

著者

Otani Sugako Kondo Hiroyuki Nonomura Itaru Hanawa Toshihiro Miura Shin'ichi Boku Taisuke

出版者

IEEE Computer Society

雑誌

IEEE micro (ISSN:02721732)

巻号頁・発行日

vol.31, no.6, pp.39-50, 2011-11

被引用文献数

6

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The PCI Express Adaptive Communication Hub (Peach) is an eight-core communication system on chip with four PCI Express Revision 2.0 ports, each with four lanes. Peach realizes a high-performance, power-aware, highly dependable network that uses PCI Express not only for connecting peripheral devices but also as a communication link between computing nodes. This approach opens up new possibilities for a range of communications.

著者

Iwamoto Hajime Hori Kenji Fukazawa Yoshimasa

出版者

Elsevier

雑誌

Tetrahedron (ISSN:00404020)

巻号頁・発行日

vol.62, no.12, pp.2789-2798, 2006-03-20

被引用文献数

12

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A new simple model of porphyrin ring current effect was proposed based on a line current approximation. It can reproduce the porphyrin-induced shifts for several Sn(IV)(tpp) and Sn(IV)(oep) dicarboxylate complexes quite satisfactorily. Perpendicular arrangement of the aromatic rings in the diaromatic-carboxylate complexes of Sn(IV)(tpp) and Sn(IV)(oep) was clarified with this porphyrin ring current effect model. There are two structures, exo and endo, in solution in dinaphthalene-1- and 2- carboxylate complexes of Sn(IV)(tpp) and Sn(IV)(oep). The exo conformer is in dynamic equilibrium with the endo form in solution. Thermodynamic data of these conformational equilibria are given.

著者

Hoshino Tetsuya Yatagai Toyohiko Itoh Masahide

出版者

Optical Society of America

雑誌

Optics Express (ISSN:10944087)

巻号頁・発行日

vol.20, no.4, pp.3954-3966, 2012-02

被引用文献数

8

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We found that the distances between isolated scatterers with similar columnar shapes could be measured by taking a single Fourier transform of their diffraction intensity. If the scatterers have different shapes, the distances between similar shapes can be selected from the distances between all the shapes. The distance from a specific scatterer can be measured with a resolution of 0.8 wavelengths and a precision of 0.01 wavelengths. This technique has the potential to be used in a novel optical memory that has a memory density as high as that of holographic memory, while can be fabricated by simple transfer molding. We used rigorous coupled-wave analysis to calculate the diffraction intensity. Some of the results were verified by nonstandard finite-difference time-domain simulations and experiments.

著者

Sakata-Yanagimoto Mamiko Nakagami-Yamaguchi Etsuko Saito Toshiki Kumano Keiki Yasutomo Koji Ogawa Seishi Kurokawa Mineo Chiba Shigeru

出版者

The National Academy of Sciences of the USA

雑誌

Proceedings of the National Academy of Sciences of the United States of America (ISSN:00278424)

巻号頁・発行日

vol.105, no.22, pp.7839-7844, 2008-06

被引用文献数

50 33

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Mast cells are thought to participate in a wide variety of pathophysiological conditions. Mechanisms of regulation, however, of mast cell production and maturation are still to be elucidated. Mast cell developmental process is likely to be profoundly affected by cell-autonomous transcriptional regulators such as the GATA family and CCAAT/enhancer binding protein (C/EBP) family members. Extracellular regulators such as stem cell factor and IL-3 have essential roles in basal and inducible mast cell generation, respectively. The relationship, however, between the extracellular signaling and cellular transcriptional control is unclear, and the trigger of the mast cell development remains elusive. Notch signaling plays a fundamental role in the lymphopoietic compartment, but its role in myeloid differentiation is less clear. Here, we demonstrate that Notch signaling connects environmental cues and transcriptional control for mast cell fate decision. Delta1, an established Notch ligand, instructs bone marrow common myeloid progenitors and granulocyte-macrophage progenitors toward mast cell lineage at the expense of other granulocyte-macrophage lineages, depending on the function of the Notch2 gene. Notch2 signaling results in the up-regulation of Hes-1 and GATA3, whereas simultaneous overexpression of these transcription factors remarkably biases the progenitor fate toward the mast cell-containing colony-forming cells. C/EBPα mRNA was down-regulated in myeloid progenitors as a consequence of Hes-1 overexpression, in agreement with the recent proposal that the down-regulation of C/EBPα is necessary for mast cell fate determination. Taken together, signaling through Notch2 determines the fate of myeloid progenitors toward mast cell-producing progenitors, via coordinately up-regulating Hes-1 and GATA3.

著者

Yang Fan Matsushita Bunkei Fukushima Takehiko Yang Wei

出版者

Elsevier B.V.

雑誌

ISPRS journal of photogrammetry and remote sensing (ISSN:09242716)

巻号頁・発行日

vol.72, pp.90-98, 2012-08

被引用文献数

52 7

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As a proxy measure of the human ecological footprint, impervious surface area (ISA) has recently become a key concept in the field of urban remote sensing, with a focus on estimation of the ISA at a city-scale by using Landsat-style satellite images. However, ISA estimation is also in demand in disciplines such as the environmental assessment and policy making at a national scale. This paper proposes a new method for estimating the ISA fraction in Japan based on a temporal mixture analysis (TMA) technique. The required inputs for the proposed method are rearranged MODIS NDVI time-series datasets at the temporal stable zone (i.e., the first to the sixth largest NDVI values in a year). Three ISA distribution maps obtained from Landsat-5 TM data were used as reference maps to evaluate the performance of the proposed method. The results showed that the proposed TMA-based method achieved a large reduction in the effects of endmember variability compared with the previous methods (e.g., SMA and NSMA), and thus the new method has promising accuracy for estimating ISA in Japan. The overall root mean square error (RMSE) of the proposed method was 8.7%, with a coefficient of determination of 0.86, and there was no obvious underestimation or overestimation for the whole ISA range.

著者

Avsar E Hatta Y Flensburg C Ollitrault J-Y Ueda T

出版者

IOP

雑誌

Journal of physics. G, Nuclear and particle physics (ISSN:09543899)

巻号頁・発行日

vol.38, no.12, pp.124053, 2011-11

被引用文献数

9 16

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High-multiplicity proton–proton collisions at the LHC may exhibit collective phenomena such as elliptic flow. We study this issue using DIPSY, a brand-new Monte Carlo event generator which features almost-NLO BFKL dynamics and describes the transverse shape of the proton including all fluctuations. We predict the eccentricity of the collision as a function of the multiplicity and estimate the magnitude of elliptic flow. We suggest that flow can be signaled by a sign change in the four-particle azimuthal correlation.

著者

Tomioka Satoshi Nishiyama Shusuke

出版者

Optical Society of America

雑誌

Applied Optics (ISSN:1559128X)

巻号頁・発行日

vol.51, no.21, pp.4984-4994, 2012-07-20

被引用文献数

23

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Phase unwrapping for a noisy image suffers from many singular points. Singularity-spreading methods are useful for the noisy image to regularize the singularity. However, the methods have a drawback of distorting phase distribution in a regular area that contains no singular points. When the singular points are confined in some local areas, the regular region is not distorted. This paper proposes a new phase unwrapping algorithm that uses a localized compensator obtained by clustering and by solving Poisson's equation for the localized areas. The numerical results demonstrate that the proposed method can improve the accuracy compared with other singularity-spreading methods.

著者

Jacek Becla Kian-Tat Lim Daniel Liwei Wang

出版者

CODATA

雑誌

Data Science Journal (ISSN:16831470)

巻号頁・発行日

vol.8, pp.MR1-MR16, 2010-02-24 (Released:2010-02-24)

被引用文献数

3

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Academic and industrial users are increasingly facing the challenge of petabytes of data, but managing and analyzing such large data sets still remains a daunting task. Both the database and the map/reduce communities worldwide are working on addressing these issues. The 3rd Extremely Large Databases workshop was organized to examine the needs of scientific communities beginning to face these issues, to reach out to European communities working on extremely large scale data challenges, and to brainstorm possible solutions. The science benchmark that emerged from the 2nd workshop in this series was also debated. This paper is the final report of the discussions and activities at this workshop.

著者

平形 道人

出版者

日本臨床免疫学会

雑誌

日本臨床免疫学会会誌 (ISSN:09114300)

巻号頁・発行日

vol.30, no.6, pp.444-454, 2007 (Released:2007-12-31)

参考文献数

65

被引用文献数

11 12

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多発性筋炎/皮膚筋炎(polymyositis/dermatomyositis : PM/DM)は,筋力低下を主徴とする慢性炎症性疾患で,その臨床像は多彩である.本疾患においても他の膠原病と同様,種々の細胞成分に対する自己抗体が高率に検出される.特に,PM/DMに特異的に見出される自己抗体(myositis-specific autoantibodies ; MSAs)は,診断,病型の分類,予後の推定,治療法の決定など臨床的に有用である.さらに,かかる自己抗体が標的とする自己抗原が細胞内の重要な生物学的機能を持つ酵素や調節因子であることが同定され,自己抗体産生機序を考える上で重要な情報をもたらしている.とくに,PMに特異的な抗アミノアシルtRNA合成酵素抗体や抗SRP抗体などが蛋白合成・翻訳と関連する細胞質蛋白を標的するのに対し,DMに特異的な抗Mi-2抗体や抗体p155抗体などが核内転写調節因子を標的とすることは,自己抗体と病態形成との関連を考える上で注目される.さらに,従来,自己抗体が稀とされてきた,amyopathic DMの抗CADM-140抗体や悪性腫瘍関連筋炎の抗p155抗体は早期診断・治療など臨床的に有用なばかりでなく,これらの疾患の病因追究に大きな手掛かりを与えるものと期待される.本稿ではPM/DMにおける自己抗体とその対応抗原や臨床的意義について,最近の知見を含め概説する.

著者

Takayuki Ishida Chihiro Tsukano Yoshiji Takemoto

出版者

(社)日本化学会

雑誌

Chemistry Letters (ISSN:03667022)

巻号頁・発行日

vol.41, no.1, pp.44-46, 2012-01-05 (Released:2011-12-24)

参考文献数

43

被引用文献数

16

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A method of synthesizing 2-iminoindolines using samarium diiodide (SmI2) is reported. In the presence of tert-butyl alcohol, treatment of carbodiimides bearing α,β-unsaturated carbonyl moieties with a stoichiometric amount of SmI2 afforded 2-iminoindolines in moderate to high yields. The products were isolated after Boc protection of the amidine moieties. This reaction proved to be applicable to lactams and acyclic/cyclic esters as substrates.

著者

Yamada H. Nakagaki T. Baker R.E. Maini P.K.

出版者

Springer Berlin / Heidelberg

雑誌

Journal of Mathematical Biology (ISSN:03036812)

巻号頁・発行日

vol.54, no.6, pp.745-760, 2007-06

被引用文献数

24

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In the large amoeboid organism Physarum, biochemical oscillators are spatially distributed throughout the organism and their collective motion exhibits phase waves, which carry physiological signals. The basic nature of this wave behaviour is not well-understood because, to date, an important effect has been neglected, namely, the shuttle streaming of protoplasm which accompanies the biochemical rhythms. Here we study the effects of self-consistent flow on the wave behaviour of oscillatory reaction-diffusion models proposed for the Physarum plasmodium, by means of numerical simulation for the dispersion relation and weakly nonlinear analysis for derivation of the phase equation. We conclude that the flow term is able to increase the speed of phase waves (similar to elongation of wave length). We compare the theoretical consequences with real waves observed in the organism and also point out the physiological roles of these effects on control mechanisms of intracellular communication.

著者

Natori Kenji

出版者

American Institute of Physics

雑誌

Journal of applied physics (ISSN:00218979)

巻号頁・発行日

vol.76, no.8, pp.4879-4890, 1994-10

被引用文献数

28 516

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Experiments on ultra-small metal-oxide-semiconductor field effect transistors (MOSFETs) less than 100 nm have been widely reported recently. The frequency of carrier scattering events in these ultra-small devices is diminished, so that further suppression of carrier scattering may bring these devices close to the regime of ballistic transport. Carrier scattering is suppressed by constructing their channel regions with intrinsic Si and also by low temperature operation. This article proposes the ballistic transport of carriers in MOSFETs, and presents the current-voltage characteristics of the ballistic n-channel MOSFET. The current is expressed with the elementary parameters without depending on the carrier mobility. It is independent of the channel length and is proportional to the channel width. The current value saturates as the drain voltage is increased and the triode and the pentode operation are specified as in the conventional MOSFET. Similar current-voltage characteristics in the ballistic transport regime are also investigated for the p-channel MOSFET, the dual gate ultra-thin silicon on insulator MOSFET, and the high electron mobility transistor device. The obtained current gives the maximum current limitation of each field effect transistor geometry. The current control mechanism of ballistic MOSFETs is discussed. The current value is governed by the product of the carrier density near the source edge in the channel, and the velocity with which carriers are injected from the source into the channel.Influence of optical phonon emission to the transport is discussed. It is suggested that if the device is operated with relatively low carrier density at low temperatures, and if the scattering processes other than the optical phonon emission are suppressed so as to attain the ballistic transport, the optical phonon emission is also suppressed and ballistic transport is sustained. A convenient figure of merit to show the ballisticity of carrier transport in an experimental MOSFET is proposed. Its value is estimated for some examples of the recent ultra-small MOSFET experiment. The proposed current voltage characteristics are evaluated for a dual gate silicon on insulator MOSFET geometry. The result is compared with the recently reported elaborate Monte Carlo simulation with satisfactory agreement.