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Showing papers by "Kyoto University published in 1976"


Journal ArticleDOI
Susumu Shima1, M. Oyane1
TL;DR: In this paper, a plasticity theory for porous metals is proposed and the stress-strain curves for sintered copper with various apparent densities are calculated by utilizing the basic equations.

766 citations


Journal ArticleDOI
TL;DR: The gas drag effect in the primordial solar nebula on the motion of a solid body, ranging from a large planetesimal to a small dust grain, is investigated in this article.
Abstract: The gas drag effect in the primordial solar nebula on the motion of a solid body, ranging from a large planetesimal to a small dust grain, is investigated. For a planetesimal, expressions for the short-term variation of the semi-major axis, the eccentricity and inclination are obtained using a perturbation method and a realistic formula for the gas drag force. For a small body, an orbit spiralling towards the sun in the equatorial plane of the nebula is investigated and the decay time of the orbital radius is obtained. It is found that the decay time at 1 a.u. is as short as 10' or 10' years for a solid body with mass in the range between 10' g and 10' g.

709 citations


Journal ArticleDOI
TL;DR: In this article, the authors show the asymptotic properties of the solutions of the linear equation with /*=0] in 2. 1 and those of the nonlinear equation (2) in 2 and 2. 3.
Abstract: utt -Au + ut +/(«, ut, Vu) - 0 . We show the asymptotic properties of the solutions of the linear equation [(2) with /*=0] in 2. 1 and those of the nonlinear equation (2) in 2. 2 and 2. 3. Notation. We denote by U the space of measurable functions u on Rn whose ^>-th powers (l

350 citations


Journal ArticleDOI
TL;DR: In this article, a Backlund transformation in the bilinear form is presented for the Toda equation, which reduces, in the special cases, to the self-dual network equation, the equation describing a Volterra system and a discrete Korteweg·de Vries equation.
Abstract: A Backlund transformation in the bilinear form is presented for the Toda equation. The Backlund transformation generates an important class of nonlinear evolution equations that exhibits N-soliton solutions. The equation reduces, in the special cases, to the Toda equation itself, the nonlinear self-dual network equation, the equation describing a Volterra system and a discrete Korteweg·de Vries equation. Physical meanings and properties of solitons of these equations are examined in detail. Special solutions are also given to the generated equation. Moreover, a relation between the Backlund transformation and the inverse scattering method, and a nonlinear transformation relating the Toda equation and the generated equation are presented.

332 citations


Journal ArticleDOI
TL;DR: In this article, N -soliton solutions of two model equations for shallow water waves are obtained, one belongs to the class of equations solvable by the inverse scattering method and the other to the classes of equations solved by the dependent variable transformation method.
Abstract: N -soliton solutions of two model equations for shallow water waves are obtained. Both equations have the same linear dispersion relations and similar nonlinearities. One of them belongs to the class of equations solvable by the inverse scattering method and the other to the class of equations solvable by the dependent variable transformation method. The difference in forms between two solutions shows the difference in characteristics between two methods.

314 citations



Book ChapterDOI
01 Jan 1976
TL;DR: In clinical medicine, the shape and dimensions of the human left ventricle have proven to be the most important parameters for evaluating the cardiac functions, and if they are obtainable, it will be possible to diagnose several cardiac diseases accurately.
Abstract: In clinical medicine, the shape and dimensions, especially their dynamical changes, of the human left ventricle have proven to be the most important parameters for evaluating the cardiac functions, and, if they are obtainable, it will be possible to diagnose several cardiac diseases accurately Currently, heart images are obtained mainly by x-ray cine-angiocardiography or RI-angiocardiography, and techniques such as manual contour tracing and hand planimetry are used by cardiologists to measure the dimensions of the left ventricle However, because the effort involved in manual methods is fairly great, computerized measurement techniques are urgently desired

240 citations


Journal ArticleDOI
TL;DR: In this article, the exact N -soliton is obtained for the two-dimentional Korteweg-deVries equation, and the solution has the same functional from as one-dimensional case.
Abstract: The exact N -soliton is obtained for the two-dimentional Korteweg-deVries equation, \begin{aligned} \frac{\partial^{2}u}{\partial t\partial x}+12\frac{\partial}{\partial x}\left (u\frac{\partial u}{\partial x}\right)+\frac{\partial^{4}u}{\partial x^{4}}{\pm}12\frac{\partial^{2}u}{\partial y^{2}}{=}0, \end{aligned} through Hirota's method. The solution has the same functional from as one-dimensional case. The two-dimensional effects are also discussed.

235 citations


Journal ArticleDOI
TL;DR: In this article, the internal stress produced by the inhomogeneous distribution of plastic strain is taken into account, and the deformation is classified into three stages with two transition points; Y(i) and Y(ii), where the softer phase starts to deform plastically while the harder phase remains elastic.

230 citations


Journal ArticleDOI
TL;DR: In this paper, a non-variational equation called the density equation is proposed for the direct determination of the density matrix without using a wave function, which is connected with the Schr\"odinger equation by a necessary and sufficient theorem.
Abstract: A nonvariational equation, called the density equation, is proposed for the direct determination of the density matrix without using a wave function. It is connected with the Schr\"odinger equation by a necessary and sufficient theorem. The equation for the lowest order depends explicitly only on the fourth-order density matrix ${\ensuremath{\Gamma}}^{(4)}$ (or ${\ensuremath{\Gamma}}^{(3)}$ in a special case) and not on the higher-order density matrices. The equation always gives the density matrix and the associated energy which coincide with those obtained indirectly from the Schr\"odinger equation. This is true even if we solve the equation only with the known and tractable $N$-representability conditions, although in such a case some unphysical solution may also occur in the non-$N$-representable space. The equation is applicable to both fermion and boson systems, and to both ground and excited states. In contrast to the Schr\"odinger equation, the labor of solving the equation does not increase when the number of particles of the system is increased. When we have the Hartree-Fock solution, the equation is transformed such that the correlated density matrix and the correlation energy are the direct solution. The correlated density equation thus obtained is suitable for the study of electron correlations.

208 citations


Journal ArticleDOI
TL;DR: The concept of the adaptive system working on the principle of minimizing the output power under the constrained response to specified directions is introduced and the differential equation approach is shown to be useful to predict the behavior of the system.
Abstract: The concept of the adaptive system working on the principle of minimizing the output power under the constrained response to specified directions is introduced. Theoretical analysis and computer simulation experiments on this directional constraint system are also presented. By comparison with the computer experiment, the differential equation approach is shown to be useful to predict the behavior of the system. The effect of error in setting the constraint direction is investigated, and it is demonstrated that the system is not very sensitive to such error. This margin can be made even greater by adopting the double directional constraints system. This system is also analyzed theoretically and experimented by computer simulation. History of output power components during adaptation is shown, which enables the comprehension of the behavior of the system.

Journal ArticleDOI
01 Jul 1976-Nature
TL;DR: Treatment of mice with cyclophosphamide significantly affects delayed hypersensitivity reaction to methylated human serum albumin (MHSA) which induces little antibody production, and it is reported that the enhanced DH reaction is caused by damage to T rather than B cells.
Abstract: THE delayed hypersensitivity (DH) reaction seems to be enhanced by treatment with cyclophosphamide and this has been discussed in the context of depression of antibody production1–4. Askenase et al.5, however, reported that low doses of cyclophosphamide augmented the reaction to sheep erythrocytes without affecting antibody production. Polak and Turk6 suggested that cyclophosphamide could break down immunological tolerance to the dinitrophenyl group, as measured by a skin reaction in guinea pigs after treatment with the drug to inhibit suppressor cells. The nature of the suppressing cells was not clear at the time. We report here that treatment of mice with cyclophosphamide also significantly affects DH reaction to methylated human serum albumin (MHSA)7 which induces little antibody production, and that the enhanced DH reaction is caused by damage to T rather than B cells. Independent recovery, from the damage due to cyclophosphamide, by individual subpopulations of T cells accounts for the kinetics of this phenomenon.

Journal ArticleDOI
TL;DR: In this article, a carbondeflagration supernova model was proposed by using a full hydrodynamic computation, where a deflagration wave propagates through the core due to convective heat transport, does not grow into detonation.
Abstract: As an alternative to the carbon detonation, we present a carbondeflagration supernova model by a full hydrodynamic computation. A deflagration wave, which propagates through the core due to convective heat transport, does not grow into detonation. Though it results in a complete disruption of the star, the difficulty of overproduction of iron peak elements can be avoided if the deflagration is relatively slow.

Journal ArticleDOI
Kichiro Endo1, H. Goto1
01 Jul 1976-Wear
TL;DR: In this article, the mechanism of fretting fatigue failure is discussed from the experimental results, and the condition of non-propagating cracks is also known, which coincides with the knee point in the propagation curve.

Journal ArticleDOI
TL;DR: Comparison of the responses in the cortex induced by stimulation of the cerebellar and thalamic nuclei indicated different relay portions in and around the VA-VL region of the thalamus for the superficial and the deep T-C responses respectively.
Abstract: 1. Responses evoked by stimulation of the cerebellar and thalamic nuclei were recorded by microelectrodes introduced at various depths in the cerebral cortex of monkeys (Macaca mulatta) under light Nembutal anaesthesia. 2. Stimulation of the medial (fastigial) cerebellar nucleus produced, at a latency of 4–5 msec, deep thalamo-cortical (T-C) responses (surface positivedeep negative potentials) mainly in the medial part of the precentral gyrus (area 4, “motor area for hindlimb”) and in the superior parietal gyrus (area 5) on both contralateral and ipsilateral sides to the nucleus stimulated. 3. Stimulation of the lateral (dentate) cerebellar nucleus elicited, at a latency of about 3 msec, superficial T-C responses (surface negative-deep positive potentials) predominantly in the lateral part of the precentral gyrus (area 4, “motor area for forelimb and face”) and in the rostromedial part of the gyrus (area 6, premotor area) on the contralateral side. 4. Stimulation of the interpositus cerebellar nucleus set up superficial T-C responses chiefly in the motor area between those influenced by the medial and the lateral cerebellar nucleus stimulation and also in the premotor area on the contralateral side. 5. The respective areas responsive to the medial, interpositus and lateral nucleus stimulation overlapped considerably each other in the motor cortex. 6. Comparison of the responses in the cortex induced by stimulation of the cerebellar and thalamic nuclei indicated different relay portions in and around the VA-VL region of the thalamus for the superficial and the deep T-C responses respectively. 7. Functional implications of the results were discussed in referring to the cerebellocerebral projections in cats.

Journal ArticleDOI
TL;DR: The present study suggests that the heterogeneity in the fluidity of intact erythrocyte membranes arises from interactions between lipids and proteins in the membrane and also from interaction between the membrane constituents and the inner proteins.

Journal ArticleDOI
TL;DR: In this article, the Schwinger-Dyson equation of the fermion propagator in the massless vector theory is discussed and it is found that the Baker-Johnson-Willey solution in lowest approximation is in fact a confining solution.

Journal ArticleDOI
01 Jul 1976-Nature
TL;DR: An elastic protein from myofibrils is isolated which is clearly distinguishable from elastin or collagen, and the chemical entity responsible for the intracellular elasticity of muscle has remained obscure.
Abstract: IT has long been assumed that an elastic component other than extracellular collagen fibres is present in muscle fibres to explain their elastic properties, especially during passive stretch1,2 The presence of such an elastic component has been demonstrated in skinned fibres of frog skeletal muscle3,4. Furthermore, it has been observed that myofibrils after the removal of myosin are reversibly extended, indicating their structural continuity5. The chemical entity responsible for the intracellular elasticity of muscle has, however, remained obscure. When rabbit myofibrils were thoroughly extracted with salt solutions such as 0.6 M KI, it was noticed that remaining Z lines still maintained their continuity, although nothing could be seen between the adjacent Z lines under a phase microscope (compare ref. 6). Starting from this observation, we have been able to isolate an elastic protein from myofibrils which is clearly distinguishable from elastin or collagen.

Journal ArticleDOI
TL;DR: 2,3-Butanediol is the only compound, other than 1,2-diols, known at present to show a considerable substrate activity, and it is found to serve as substrate for the enzyme, whereas 1, 3-propanediol was not.

Journal ArticleDOI
TL;DR: In this article, the null-plane quantization is studied with the emphasis on the P+=O mode, by using Dirac's quantization for constrained systems, and the physical vacuum can be defined in a kinematical way.
Abstract: The null-plane quantization is studied with the emphasis on the P+=O mode, by using Dirac's quantization for constrained systems. This mode is eliminated from the Hilbert space and the physical vacuum can be defined in a kinematical way. It enables us to con­ struct the physical Fock space kinematically. Poincare invariance is also studied in detail.

Journal ArticleDOI
TL;DR: In this paper, the effect of the effective action on the Euler-Lagrange equation was studied in general gauge theories, and explicit expressions which manifest all the gauge dependences of the action and potential $V$ were obtained.
Abstract: The gauge dependence of the effective action $\ensuremath{\Gamma}$ and potential $V$ are studied in general gauge theories. Explicit expressions which manifest all the gauge dependences of $\ensuremath{\Gamma}$ and $V$ are obtained. From these equations, it is concluded that $\ensuremath{\Gamma}$ (or $V$) has gauge-invariant values for any solution of the Euler-Lagrange equation $\frac{\ensuremath{\delta}\ensuremath{\Gamma}}{\ensuremath{\delta}\ensuremath{\varphi}}=0$ (or $\frac{\ensuremath{\partial}V}{\ensuremath{\partial}\ensuremath{\varphi}}=0$) Introduction of a certain concept about the categories of gauge conditions resolves the appearance of a gauge-dependent unphysical "vacuum." Any gauge can be used to calculate $\ensuremath{\Gamma}$. A wide class of gauges are allowed for the effective potential $V$; for instance, in scalar QED the allowed gauges are $\ensuremath{-}(\frac{1}{2}\ensuremath{\alpha}){(\ensuremath{\partial}A)}^{2}$, $\ensuremath{-}(\frac{1}{2}\ensuremath{\alpha}){(\ensuremath{\partial}A\ensuremath{-}v{\ensuremath{\Phi}}_{2})}^{2}$ (where the direction of condensation is restricted to ${\ensuremath{\Phi}}_{1}$), the Coulomb gauge, and the axial gauge. In particular the ${R}_{\ensuremath{\xi}}$ gauge is also an allowed gauge.

Journal ArticleDOI
TL;DR: Alcohol oxidase (alcohol: oxygen oxidoreductase) of a thermophilic methanol-utilizing yeast, Hansenula polymorpha DL-1, was isolated in crystalline form and was more stable to heat than was the enzyme of Kloeckera sp.polymorpha, compatible with the difference in growth temperatures for both yeasts.
Abstract: 1. Alcohol oxidase (alcohol: oxygen oxidoreductase) of a thermophilic methanol-utilizing yeast, Hansenula polymorpha DL-1, was isolated in crystalline form. 2. This alcohol oxidase of H. polymorpha was more stable to heat than was the enzyme of Kloeckera sp. This difference in heat stability is compatible with the difference in growth temperatures for both yeasts. 3. The crystalline alcohol oxidases of both yeast oxidized the lower primary alcohols (C-2 to C-4) as well as methanol. The apparent Km values for the methanol of Kloeckera and H. polymorpha enzymes were 0.44 and 0.23 mM, respectively. The enzymes could also oxidize formaldehyde to formate, and were inactivated by relatively low concentrations of hydrogen peroxide. 4. The molecular weight for both enzymes was calculated to be about 670000. Each enzyme is composed of eight identical subunits (molecular weight 83000) and contains eight moles of FAD as the prosthetic group. The NH2-terminal and COOH-terminal amino acids of H. polymorpha enzyme were identified as alanine and phenylalanine, respectively. The octameric subunits model of each enzyme was confirmed by electron micrographs, which showed an octad aggregate, composed of two tetragons face to face.

Journal ArticleDOI
Yoji Nakamura1
TL;DR: In this paper, the fundamental physical nature of the Invar problem is discussed and the physical background of the Elinvar alloys is also presented, and the basic ideas of the various interpretations of the invar effects, as well as the microscopic properties of Invar alloy are summarized.
Abstract: The purpose is to make clear the fundamental physical nature of the Invar problem, disregarding its details. After a brief discussion of the practical applications of the Invar alloys, the large magnetovolume effects and the anomalous magnetic properties are reviewed. The basic ideas of the various interpretations of the Invar effects, as well as the microscopic properties of the Invar alloys, are summarized. The physical background of the Elinvar alloys is also presented. Recent observations of Invar-type effects in new materials suggest that the Invar effect is rather common in itinerant ferro- and antiferromagnets.

Journal ArticleDOI
TL;DR: In an attempt to elucidate the mechanicms underlying the production of transepidcrmal migration of leukocytes toward the stratum corneum in psoriatic lesions, the chcmotactic properties of soluble substances in psoriasis scales were examined by a modified Boydm's chamber.
Abstract: In an attempt to elucidate the mechanisms underlying the production of transepidermal migration of leukocytes toward the stratum corneum in psoriatic lesions, the chemotactic properties of soluble substances in psoriasis scales were examined by a modified Boyden's chamber. All crude extracts of horny tissues studied, i.e. callus, scales of exfoliative dermatitis and of psoriasis vulgaris, showed chemotactic activity for human peripheral blood leukocytes. But only the chemotactic activity of the psoriasis scale extract was highly potent. This was greatly reduced after dialysis. Fresh serum was not required to manifest the chemotactic activity. By Sephadex G-200 chromatography, the scale extracts from psoriasis vulgaris and pustular psoriasis had potent activity eluted near the cytochrome C marker. The same fractions of other horny tissue extracts, bacterial filtrate prepared from cultured psoriasis scale fragments, and serum did not show such potent activity. On the basis of analysis by gel filtration and recent findings of immunopathological studies, a postulate was made that a complement derived chemotactic factor, possibly a C5 cleavage product, developed as a result of antigen-antibody reaction in the stratum corneum of psoriatic lesions.

Journal ArticleDOI
Osamu Hayaishi1
TL;DR: This novel enzyme produced a new class of biogenic amines, which may be referred to, generically, as "anthraniloylamines," which may have hitherto unknown biological or pharmacological activities and are currently under investigation in the laboratory.
Abstract: Available evidence indicates that indoleamine 2,3-dioxygenase, which is particularly abundant in the lung, colon, and intestine, catalyzes the oxidative ring cleavage of the pyrrole moiety of not only tryptophan and 5-hydroxytryptophan but also serotonin, melatonin, and other indoleamine derivatives. Our recent experiments with slices of intestine, together with those with organ culture of pineal glands, perfusion of heart and lung preparations and intact animals, which I did not have time to mention today, indicate that the oxygenative ring cleavages of various indoleamines do occur in vivo to a significant extent. Secondly, this enzyme appears to utilize superoxide anion rather than molecular oxygen. If superoxide anion is demonstrated, unequivocally, to be the true substrate of this enzyme, not only in vitro but also in vivo, then indoleamine 2,3-dioxygenase may be the first example of a new class of enzymes which utilize superoxide anion as an oxidizing agent just as peroxidases utilize hydrogen peroxide. Lastly, this novel enzyme produced a new class of biogenic amines, which may be referred to, generically, as "anthraniloylamines." Although their natural occurrence has not yet been established, they may have hitherto unknown biological or pharmacological activities and are currently under investigation in our laboratory.

Journal ArticleDOI
TL;DR: Dielectric measurements were made on suspensions of intact yeast cells over a frequency range of 10 kHz to 100 MHz and the relatively low dielectric constant of about 50 obtained for the cell interior, in comparison with values of aqueous solutions, may be attributed also to the presence of intracellular organelles and proteins.
Abstract: Dielectric measurements were made on suspensions of intact yeast cells over a frequency range of 10 kHz to 100 MHz. The suspensions showed typical dielectric dispersions, which are considered to be caused by the presence of cytoplasmic membranes with sufficiently low conductivity. Since the conductivity of the cell wall was found to be of nearly the same value as that of the suspending medium, composed of KCl solutions in a range from 10 to 80mm, the cell wall may be ignored in establishing an electrical model of the cells suspended in such media. An analysis of the dielectric data was carried out by use of Pauly and Schwan's theory. The membrane capacitance was estimated to be 1.1±0.1 μF/cm2, which is compared with values reported so far for most biological membranes. The conductivity of the cell interior was almost unchanged with varying KCl concentrations and showed low values owing to the presence of less conducting particles, presumably intracellular organelles. The relatively low dielectric constant of about 50 obtained for the cell interior, in comparison with values of aqueous solutions, may be attributed also to the presence of intracellular organelles and proteins.

Journal ArticleDOI
TL;DR: In this paper, a multisoliton solution of the Korteweg-de Vries equation with loss and non-uniformity terms was obtained, and the solutions express multisolidons damping in time without radiation and mutually colliding in nonuniform media with a relaxation effect.
Abstract: N -soliton solution of the Korteweg-de Vries equation with loss and nonuniformity terms \begin{aligned} u_{t}+2{\alpha}u+(C_{0}+{\alpha}x)u_{x}+6uu_{x}+u_{xxx}=0, \end{aligned} are obtained. The solutions express multisolitons damping in time without radiation and mutually colliding in nonuniform media with a relaxation effect.

Journal ArticleDOI
TL;DR: Evidence is presented for Substance P as a putative excitatory transmitter onto reticular and nigral neurones possibly released from primary sensory afferents and in some cases this excitation was rapid.
Abstract: Extracellular recordings were made from neurones in the mesencephalic reticular formation and substantia nigra of the rat which was anaesthetized with urethane 1.5–2 g/kg i.p. Out of 44 cells tested 42 were excited by Substance P applied iontophoretically and in some cases this excitation was rapid. Evidence is presented for Substance P as a putative excitatory transmitter onto reticular and nigral neurones possibly released from primary sensory afferents.

Journal ArticleDOI
TL;DR: The transverse distribution across the cerebellar folium of the basket-stellate cell inhibitory action on Purkinje cells was found to be narrow up to 60 days after birth, and some implications of the dates of commencement of excitatory and inhibitory synaptic actions in the Cerebellar cortex were discussed.

Journal ArticleDOI
TL;DR: In this article, the authors considered the flow streaming into a porous and permeable medium with arbitrary but smooth wall surface and considered the Euler equation (in the pure fluid region) and generalized Darcy's law in which the convective acceleration is taken into account.
Abstract: The flow streaming into a porous and permeable medium with arbitrary but smooth wall surface is considered on the basis of the Euler equation (in the pure fluid region) and a generalized Darcy's law in which the convective acceleration is taken into account. The asymptotic behavior of the flow for small permeability of the medium is investigated. It is shown that the flow in the porous medium is irrotational except in the boundary layer next to the surface. The velocity distribution in the boundary layer is given in a universal form. Proper boundary conditions connecting the potential flow in the pure fluid region and the potential flow in the porous medium are obtained when the boundary layer is neglected.