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Study of entropy production in Yang-Mills theory with use of Husimi function [article]

Hidekazu Tsukiji, Hideaki Iida, Teiji Kunihiro, Akira Ohnishi, Toru T. Takahashi
2015 arXiv   pre-print
Understanding the thermalization process in a pure quantum system is a challenge in theoretical physics. In this work, we explore possible thermalization mechanism in Yang-Mills(YM) theory by using a positive semi-definite quantum distribution function called a Husimi function which is given by a coarse graining of the Wigner function within the minimum uncertainty. Then entropy is defined in terms of the Husimi function, which is called the Husimi-Wehrl(HW) entropy. We propose two numerical
more » ... hods to calculate the HW entropy. We find that it is feasible to apply the semi-classical approximation with the use of classical YM equation. It should be noted that the semi-classical approximation is valid in the systems of physical interest including the early stage of heavy-ion collisions. Using a product ansatz for the Husimi function, which is confirmed to reproduce the HW entropy within 20% error (overestimate) for a few-body quantum system, we succeed in a numerical evaluation of HW entropy of YM fields and show that it surely has a finite value and increases in time.
arXiv:1511.03804v1 fatcat:mznxcnr3f5aexboi2gdep3djli

Entropy production and isotropization in Yang-Mills theory with use of quantum distribution function [article]

Hidekazu Tsukiji, Teiji Kunihiro, Akira Ohnishi, Toru T. Takahashi
2017 arXiv   pre-print
We investigate thermalization process in relativistic heavy ion collisions in terms of the Husimi-Wehrl (HW) entropy defined with the Husimi function, a quantum distribution function in a phase space. We calculate the semiclassical time evolution of the HW entropy in Yang-Mills field theory with the phenomenological initial field configuration known as the McLerran-Venugopalan model in a non-expanding geometry, which has instabilty triggered by initial field fluctuations. HW-entropy production
more » ... mplies the thermalization of the system and it reflects the underlying dynamics such as chaoticity and instability. By comparing the production rate with the Kolmogorov-Sinaï rate, we find that the HW entropy production rate is significantly larger than that expected from chaoticity. We also show that the HW entropy is finally saturated when the system reaches a quasi-stationary state. The saturation time of the HW entropy is comparable with that of pressure isotropization, which is around 1 fm/c in the present calculation in the non-expanding geometry.
arXiv:1709.00979v1 fatcat:aqhkoi2rrvhozfoztq5lr4m7ai

Correction for partial-volume effects on brain perfusion SPECT in healthy men

Hiroshi Matsuda, Takashi Ohnishi, Takashi Asada, Zhi-jie Li, Hidekazu Kanetaka, Etsuko Imabayashi, Fumiko Tanaka, Seigo Nakano
2003 Journal of Nuclear Medicine  
The limited spatial resolution of SPECT scanners does not allow an exact measurement of the local radiotracer concentration in brain tissue because partial-volume effects (PVEs) underestimate concentration in small structures of the brain. The aim of this study was to determine which brain structures show greater influence of PVEs in SPECT studies on healthy volunteers and to investigate aging effects on SPECT after the PVE correction.
pmid:12902414 fatcat:in72otgtfzgqpg2ptpgaldn3ym

SIRPα signaling regulates podocyte structure and function

Satoshi Takahashi, Mai Tomioka, Keiju Hiromura, Toru Sakairi, Hiroko Hamatani, Mitsuharu Watanabe, Hidekazu Ikeuchi, Yoriaki Kaneko, Akito Maeshima, Takeo Aoki, Hiroshi Ohnishi, Takashi Matozaki (+1 others)
2013 AJP - Renal Physiology  
Signal-regulatory protein-␣ (SIRP␣) is a transmembrane protein that contains tyrosine phosphorylation sites in its cytoplasmic region; two tyrosine phosphatases, SHP-1 and SHP-2, bind to these sites in a phosphorylationdependent manner and transduce multiple intracellular signals. Recently, SIRP␣ was identified as one of the major tyrosine-phosphorylated proteins in the glomeruli and found to be expressed in podocytes. In the present study, we examined the role of SIRP␣ expression in podocytes
more » ... sing knockin mice (C57BL/6 background) expressing mutant SIRP␣ that lacks a cytoplasmic region (SIRP␣mutant mice). Light microscopic examination revealed no apparent morphological abnormalities in the kidneys of the SIRP␣-mutant mice. On the other hand, electron microscopic examination revealed abnormal podocytes with irregular major processes and wider and flattened foot processes in the SIRP␣-mutant mice compared with their wild-type counterparts. Significantly impaired renal functions and slight albuminuria were demonstrated in the SIRP␣-mutant mice. In addition, adriamycin injection induced massive albuminuria together with focal glomerulosclerosis in the SIRP␣-mutant mice, while their wild-type counterparts were resistant to adriamycin-induced nephropathy. These data demonstrate that SIRP␣ is involved in the regulation of podocyte structure and function as a filtration barrier under both physiological and pathological conditions. * S. Takahashi and M. Tomioka contributed equally to this work.
doi:10.1152/ajprenal.00597.2012 pmid:23842779 fatcat:hn2r5kyi5ng2ndzruuztytu2qm

1H, 13C, and 15N resonance assignment of the TIR domain of human MyD88

Hidenori Ohnishi, Hidehito Tochio, Zenichiro Kato, Takeshi Kimura, Hidekazu Hiroaki, Naomi Kondo, Masahiro Shirakawa
2010 Biomolecular NMR Assignments  
The dimerization appears to be mediated via homomeric interactions within its death domain (Ohnishi et al., 2009) .  ...  These results exemplified the binding specificity among TIRs and its importance in forming correct signal initiation complexes (Ohnishi et al., 2009 ).  ... 
doi:10.1007/s12104-010-9222-0 pmid:20354830 fatcat:u4ik7mm2ujgnlgdnssiaclqzp4

Mechanism of mature neuron-specific toxicity induced by high-mass amyloid β-protein assembly with a unique toxic structure

Minako Hoshi, Takayuki Ohnishi, Masafumi Inoue, Hidekazu Hiroaki, Yo-ichi Nabeshima, Akiyoshi Kakita
2011 Alzheimer's & Dementia  
peroxide (H2O2) and intraceluular reactive oxygen species (ROS). Results: From the results of the MTT assay, the cell viability of cortical neurons treated with Aß was obviously increased by curcumin in a concentration-dependent manner. The data derived from the Hoechst 33342 and LDH assay support the results from MTT assay. The following evaluation of extracellular and intracellular oxidative stress indicated that curcumin depressed Aß-induced the elevation of extracellular H2O2 and
more » ... ar ROS. Conclusions: These findings suggest that curcumin protects primary cortical neurons form Aß-induced neurotoxicity in by the manner of depressing oxidative stress. It will be helpful to further develop the usage of curcumin in AD therapy.
doi:10.1016/j.jalz.2011.05.1168 fatcat:wwlu5xn42jfu7mcbb2vat5mhr4

Effect of microstructure on stress corrosion susceptibility of Al-Mg alloy

Tadakazu OHNISHI, Yoshizo NAKATANI, Hidekazu SAKAMOTO
1976 Keikinzoku/Journal of Japan Institute of Light Metals  
Effect of microstructure on stress corrosion susceptibility of Al-Mg alloy UDC 669.715'721: 620.194: 620.186
doi:10.2464/jilm.26.8 fatcat:cddrkx4xgzd4dllaxwvxr5pezq

Establishment of a Model of Spontaneously-Running-Tokushima-Shikoku Rats with Left Atrial Thrombosis

Takamasa Ohnishi, Fumiko Hisaoka, Masaki Morishima, Akira Takahashi, Nagakatsu Harada, Kazuaki Mawatari, Hidekazu Arai, Emiko Yoshioka, Satomi Toda, Keisuke Izumi, Yutaka Nakaya
2014 Journal of Toxicologic Pathology  
Studies that investigate the underlying mechanisms of disease and treatment options typically require the use of a suitable animal model. Few suitable animal models exist for left atrial thrombosis. Here, we demonstrated that the Spontaneously-Running-Tokushima-Shikoku (SPORTS) rat -a Wistar strain known for its running ability-is predisposed to the development of thrombi in the left atrium. We investigated the incidence of left atrial thrombosis in male (n = 16) and female (n = 17) SPORTS rats
more » ... and observed organized atrial thrombosis in 57% and 38% of males and female rats, respectively. In the male rats, systolic blood pressures and heart rates were significantly higher in SPORTS rats than in control Wistar rats. We could not find any evidence of arrhythmias, such as atrial fibrillation, during electrocardiographic examination of SPORTS rats. We believe that the SPORTS rat could serve as a new research model for left atrial thrombosis; further, it may be suitable for research investigating the development of new antithrombotic approaches for the control of atrial thrombosis or familial thrombophilia in humans. (
doi:10.1293/tox.2012-0032 pmid:24791067 pmcid:PMC4000073 fatcat:zqx6ghpev5e2roh726d5okxlti

Entropy production from chaoticity in Yang-Mills field theory with use of the Husimi function

Hidekazu Tsukiji, Hideaki Iida, Teiji Kunihiro, Akira Ohnishi, Toru T. Takahashi
2016 Physical Review D  
We investigate possible entropy production in Yang-Mills (YM) field theory by using a quantum distribution function called Husimi function f_ H(A, E, t) for YM field, which is given by a coarse graining of Wigner function and non-negative. We calculate the Husimi-Wehrl (HW) entropy S_ HW(t)=- Trf_H f_H defined as an integral over the phase-space, for which two adaptations of the test-particle method are used combined with Monte-Carlo method. We utilize the semiclassical approximation to obtain
more » ... he time evolution of the distribution functions of the YM field, which is known to show a chaotic behavior in the classical limit. We also make a simplification of the multi-dimensional phase-space integrals by making a product ansatz for the Husimi function, which is found to give a 10-20 per cent over estimate of the HW entropy for a quantum system with a few degrees of freedom. We show that the quantum YM theory does exhibit the entropy production, and that the entropy production rate agrees with the sum of positive Lyapunov exponents or the Kolmogorov-Sinai entropy, suggesting that the chaoticity of the classical YM field causes the entropy production in the quantum YM theory.
doi:10.1103/physrevd.94.091502 fatcat:efrt4ktlabdtfgfsde355f42g4

Spin-orbit coupling suppression and singlet-state blocking of spin-triplet Cooper pairs

Sachio Komori, James M. Devine-Stoneman, Kohei Ohnishi, Guang Yang, Zhanna Devizorova, Sergey Mironov, Xavier Montiel, Linde A. B. Olde Olthof, Lesley F. Cohen, Hidekazu Kurebayashi, Mark G. Blamire, Alexandre I. Buzdin (+1 others)
2021 Science Advances  
An inhomogeneous magnetic exchange field at a superconductor/ferromagnet interface converts spin-singlet Cooper pairs to a spin-polarized triplet state. Although the decay envelope of triplet pairs within ferromagnetic materials is well studied, little is known about their decay in nonmagnetic metals and superconductors and, in particular, in the presence of spin-orbit coupling (SOC). Here, we investigate devices in which singlet and triplet supercurrents propagate into the s-wave
more » ... Nb. In the normal state of Nb, triplet supercurrents decay over a distance of 5 nm, which is an order of magnitude smaller than the decay of spin-singlet pairs due to the SOC. In the superconducting state of Nb, triplet supercurrents are not able to couple with the singlet wave function and are thus blocked by the absence of available equilibrium states in the singlet gap. The results offer insight into the dynamics between s-wave singlet and s-wave triplet states.
doi:10.1126/sciadv.abe0128 pmid:33523885 fatcat:wlzrrb4icrebblae73ovpak2k4

Entropy production in quantum Yang–Mills mechanics in the semiclassical approximation

Hidekazu Tsukiji, Hideaki Iida, Teiji Kunihiro, Akira Ohnishi, Toru T. Takahashi
2015 Progress of Theoretical and Experimental Physics  
We discuss thermalization of isolated quantum systems by using the Husimi-Wehrl entropy evaluated in the semiclassical treatment. The Husimi-Wehrl entropy is the Wehrl entropy obtained by using the Husimi function for the phase space distribution. The time evolution of the Husimi function is given by smearing the Wigner function, whose time evolution is obtained in the semiclassical approximation. We show the efficiency and usefullness of this semiclassical treatment in describing entropy
more » ... tion of a couple of quantum mechanical systems, whose classical counter systems are known to be chaotic. We propose two methods to evaluate the time evolution of the Husimi-Wehrl entropy, the test-particle method and the two-step Monte-Carlo method. We demonstrate the characteristics of the two methods by numerical calculations, and show that the simultaneous application of the two methods ensures the reliability of the results of the Husimi-Wehrl entropy at a given time.
doi:10.1093/ptep/ptv107 fatcat:4l22kmdh7vh27inm7lx7yfwqwa

Revascularization Using a Superficial Temporal Artery Graft to Replaced a Failed Encephalo-myo-synangiosis in a Moyamoya Disease Patient

Hajime Touho, Hidekazu Takahashi, Jun Krasawa, Hideyuki Ohnishi, Hiroyuki Nakase, Norihiiko Furuoka, Takeki Komatsu
1994 Japanese Journal of Neurosurgery  
The authors report the case of an 11 − year − c〕 ld girl who was admitted to hospita 玉on November 4 , 1992 because of persistent quadriparesis, motor aphasia , and mental retardation . On January l,1984, she had had a cerebral infarction and was diagnosed as having moyamoya disease , She thus was surgicall } ・ treated and underwent a bilateral encephalo − myo − synangiosis ( EMS ) , Postoperatively , however , the patient did not show any improvement, On Novelnber 4, 1992 , because of failure
more » ... the left EMS , she again underwent surgery for a vascular reconstruction . Since the previous horse sh 〔 〕 e incision on the left side had the left parietal branch of the superficial temporal artery ( STA ) and the posterior auricular artery ( PAA ) with too small a diameter ( 0. 3 mm ) and too short alength , 3cm of the STA was interposed between the PAA and a branch of the left middle cerebral artery . After this surgery , a slight improvement was noted in the motor weal {ness of the right upper extremity and the motor aphasia . In this report , the authors a ! so introduce vascular reconstruction techniques for a failed EMS . (
doi:10.7887/jcns.3.150 fatcat:jjadm5jc2bhvdf2teh5dfuia7y

Importance of methodology in the evaluation of renal mononuclear phagocytes and analysis of a model of experimental nephritis with Shp1 conditional knockout mice

Mitsuharu Watanabe, Yoriaki Kaneko, Yuko Ohishi, Masato Kinoshita, Toru Sakairi, Hidekazu Ikeuchi, Akito Maeshima, Yasuyuki Saito, Hiroshi Ohnishi, Yoshihisa Nojima, Takashi Matozaki, Keiju Hiromura
2020 Biochemistry and Biophysics Reports  
Hidekazu Ikeuchi: Validation. Akito Maeshima: Validation. Yasuyuki Saito: Validation. Hiroshi Ohnishi: Validation, Writing -original draft. Yoshihisa Nojima: Validation.  ... 
doi:10.1016/j.bbrep.2020.100741 pmid:32154390 pmcid:PMC7057148 fatcat:kfav3oqy4zfvxfgfb3qeou5spy

The Effect of an Amino Acid Administration on the General Metabolism of Patients with an Acute-stage, Ruptured, Intracranial Aneurysm

Hajime Touho, Jun Krasawa, Hideyuki Ohnishi, Hiroyuki Nakase, Keisuke Yamada, Norihiko Furuoka, Makoto Takaoka, Makoto Seno, Hidekazu Takahashi, Takeki Komatsu, Gao Bao Shan
1994 Japanese Journal of Neurosurgery  
Key words : subarachlloid hemor1 ' hage , general metabolism , amh /o acid , nitrogen balance、 protein ・ sparing effect Jpn J Neurosurg
doi:10.7887/jcns.3.4 fatcat:fgvnqrf3gbcvjauvz5ft7z5enq
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