Showing papers by "University of Tokyo published in 1973"
TL;DR: In this paper, the relative and absolute abundances of chondrites were determined by mass-spectrometric stable isotope dilution techniques and a comparison was made with the results on the chondrite composites previously investigated.
761 citations
TL;DR: In this article, the evolution of the variable along the most probable path and fluctuation properties around the path are considered from a general point of view with an emphasis on the relation of nonlinearity of evolution and the associated fluctuation.
Abstract: Assuming that a macrovariable follows a Markovian process, the extensive property of its probability distribution is proved to propagate. This is a generalization of the Gaussian properties of the equilibrium distribution to nonequilibrium nonstationary processes. It is basically a WKB-like asymptotic evaluation in the inverse of the size of the macrosystem. Evolution of the variable along the most probable path and fluctuation properties around the path are considered from a general point of view with an emphasis on the relation of nonlinearity of evolution and the associated fluctuation. Anomalous behavior of the fluctuation is discussed in connection with unstable, critical, or marginal states. A general treatment is given for the asymptotic properties of relaxation eigenmodes.
621 citations
TL;DR: In this paper, a family of numerical quadrature formulas is introduced by application of the trapezoidal rule to infinite integrals which result from the given integrals f b \ f(x)dx by suitable variable transformations x =
Abstract: A family of numerical quadrature formulas is introduced by application of the trapezoidal rule to infinite integrals which result from the given integrals f b \ f(x)dx by suitable variable transformations x =
584 citations
TL;DR: In this article, the anomalous temperature dependence of the strength in Ni3Ga with Ll2 structure was investigated by deformation in compression at temperatures between 77 °K and 1000 °K.
542 citations
TL;DR: In this article, the authors examined the structure and composition of the passive film formed in sulphuric acid solution at definite potentials in the passive region, and the most important parameter controlling the corrosion resistance of the steel is concluded to be the amorphous nature of the film in which bound water is included.
381 citations
TL;DR: The results indicate the presence of two carrier-mediated uptake systems for choline, one of which requires Na+ for the uptake and the other does not.
380 citations
TL;DR: In this paper, the effect of spin fluctuations on itinerant electron ferromagnetism was extended to include the ferromagnetic phase and the correction to the Hartree-Fock free energy as a function of magnetization was expressed in terms of the transversal dynamical susceptibilities.
Abstract: The theory of the effect of spin fluctuations on itinerant electron ferromagnetism, which we have developed previously, is extended to include the ferromagnetic phase. The correction to the Hartree-Fock free energy as a function of magnetization is expressed in terms of the transversal dynamical susceptibilities and is actually calculated by using a modified random phase approximation for the dynamical susceptibilities; the random phase approximation is modified so as to give a consistent static limit throughout the whole temperature range covering both below and above the Curie point. As a result, the magnetization at low temperatures shows a T 3/2 dependence due to the spin wave excitations, the Curie temperature is generally lowered from the Stoner (Hartree-Fock) value and the magnetic susceptibility above the Curie temperature shows an approximate Curie-Weiss behavior.
307 citations
TL;DR: In this article, the lift and drag forces were measured on both a single circular cylinder and tandem circular cylinders in uniform flow at Reynolds numbers from 40 to 104, to investigate the stability of an oscillating cylinder.
Abstract: The lift and drag forces were measured on both a single circular cylinder and tandem circular cylinders in uniform flow at Reynolds numbers from 40 to 104, to investigate the stability of an oscillating cylinder A cylinder (the downstream one in the tandem case) was made to oscillate in either the transverse or longitudinal direction (perpendicular or parallel to the stream) In the case of a single cylinder, its oscillation causes the so-called synchronization in a frequency range around the Strouhal frequency (transverse mode) or double the Strouhal frequency (longitudinal mode) The aerodynamic damping for transverse oscillation becomes negative in the synchronization range In the case of tandem cylinders, at low Reynolds numbers in the pure Karman range synchronization was observed to occur only when the downstream cylinder oscillated inside the vortex-formation region of the upstream one, and at high (low subcritical) Reynolds numbers synchronization occurred irrespective of the cylinder spacing in either oscillating mode In the tandem case, too, the transverse oscillation of the downstream cylinder becomes unstable in the range of synchronization
282 citations
241 citations
TL;DR: In this article, a tensor operator method is employed in order to take account of the individual characters of the energy levels involved in the transition and the typical transition probability is also made on the lowest-order parity-allowed processes in nearest neighbour ions.
Abstract: Calculations made of the rates for several processes involving interactions between rare earth ions in crystals, such as resonance energy transfer, cooperative excitation transfer and cooperative optical transitions These processes are assumed to originate from the electric multipole interactions between the ions concerned A tensor operator method is employed in order to take account of the individual characters of the energy levels involved in the transition Evaluation of the typical transition probability is also made on the lowest-order parity-allowed processes in nearest neighbour ions The rates for the resonance transfer and cooperative transfer processes thus estimated are much smaller than those obtained by Miyakawa and Dexter
238 citations
TL;DR: The mechanism of gamete release and oocyte maturation in starfishes, based on the action of gonad-stimulating substance (GSS) and maturation-inducing substance (MIS), I-methyladenine, is summarized in the chapter.
Abstract: Publisher Summary This chapter discusses the maturation-inducing substance in starfishes. It reviews the mechanism of reproductive phenomena in starfishes based on the physiological activities of two substances, a gonad-stimulating hormonal peptide of neural origin and a maturation-inducing substance produced in the gonad under the influence of the former. The mechanism of gamete release and oocyte maturation in starfishes, based on the action of gonad-stimulating substance (GSS) and maturation-inducing substance (MIS), I-methyladenine, is summarized in the chapter. These reproductive phenomena are effected under hormonal influence in starfishes. Once GSS is liberated from the nerves, it reaches the celomic cavity and enters the ovary, and the cells of the follicles around the oocytes respond to GSS by producing I-methyladenine. The starfish gonad contains a substance that suppresses cell division of Chaetopterus and Arbacia eggs and seems to block oocyte meiosis in starfishes. Starfish oocytes remain in the germinal vesicle stage until just before spawning occurs, whereas spermatogenesis proceeds all the way to the formation of spermatozoa long before the release of sperm. However, the localization in the ovary, chemical nature, and mechanism of action under physiological conditions of such a substance are still obscure.
TL;DR: One of the microbial products produced from dibenzothiophene by Pseudomonas abikonensis or P. jianii was identified as a new substance, trans-4[2-(3-hydroxy)-thianaphthenyl]-2-oxo-3-butenoic acid, and the other as its hemiacetal form as mentioned in this paper.
Abstract: One of the microbial products produced from dibenzothiophene by Pseudomonas abikonensis or P. jianii was identified as a new substance, trans-4[2-(3-hydroxy)-thianaphthenyl]-2-oxo-3-butenoic acid, and the other as its hemiacetal form. From the structures of the products, an oxidation pathway of dibenzothiophene was suggested. Moreover, the culture broth and the isolated products were examined for plant growth activities on rice plants.
TL;DR: This chapter discusses that incorporation of radioactivity of (adenine- 14 C) ATP into the acid insoluble material in a nuclear preparation from hen liver is enhanced at least 1000-fold by the presence of NMN.
Abstract: Publisher Summary This chapter discusses that incorporation of radioactivity of (adenine- 14 C) ATP into the acid insoluble material in a nuclear preparation from hen liver is enhanced at least 1000-fold by the presence of NMN. It is confirmed that this stimulation: using a nuclear preparation from rat liver. On founding that the acid-insoluble reaction product was not converted to an acid soluble form by treatment in 0.5N NaOH at 37° for 18 hours, we concluded that it was not poly (A). The reaction product was hydrolyzed by snake venom phosphodiesterase, and an unknown, radioactive substance was isolated from the hydrolyzate, which accounted for most of the initial reaction product and differed from 5'-AMP. The nuclear preparations contain NAD pyrophosphorylase, which produces (adenine- 14 C) NAD from (adenine- 14 C) ATP and NMN. These preparations also catalyze the polymerization of the ADP-Rib moiety of NAD. Thus, the reaction product found was (adenine- l4 C) poly (ADP-Rib).
TL;DR: It is proposed that afferent volleys from the neck joint ascend ipsilaterally in the spinal cord, cross to the contralateral side in the brain stem, and eventually project to the vestibular nuclei, thus interacting with the Vestibulo-ocular reflex activity.
Abstract: The effect of neck afferents on abducens motoneurons and their interaction with the vestibulo-abducens reflex were examined in chloraloseanesthetized or unanesthetized, decerebrate cats. The test reflex elicited in the abducens nerve by stimulation of the contralateral vestibular nerve was inhibited by contralateral and facilitated by ipsilateral cervical dorsal root or neck joint stimulation. These reciprocal effects were obtained by stimulation at the level of C2 and C3, but not from C5 or lower. Contralateral and ipsilateral cervical stimulation induced IPSPs and EPSPs, respectively, in abducens motoneurons. The latencies were 2.8–6.0 msec for the IPSP and 2.8–5.3 msec for the EPSP after stimulation of the dorsal root. The labyrinthine-induced disynaptic IPSP or EPSP was facilitated by conditioning stimulation of the contralateral and ipsilateral cervical dorsal root, respectively. It is thus postulated that the cervico-abducens and vestibuloabducens reflex pathways converge upon common inhibitory or excitatory interneurons in the vestibular nuclie. Labyrinthine- and cervical-induced responses of the presumed interneurons in the vestibular nuclei or those of their axons recorded in the abducens nuclie were consistent with the above view. Lesion experiments in the brain stem indicated that afferent volleys from the neck joint ascend ipsilaterally in the spinal cord, cross to the contralateral side in the brain stem, and eventually project to the vestibular nuclei, thus interacting with the vestibulo-ocular reflex activity. A possible functional role of the cervical effects on the ocular motoneuron was briefly discussed.
TL;DR: In this paper, the results of two independent electron-diffraction investigations of cyclohexane are compared, and the following parameters and error limits are obtained: r g (CC) = 1.536±0.002 A, r g(CH) =1.121± 0.004 A, and ∠CCC = 111.4±1.2°.
TL;DR: In this paper, it has been found that shear moduli for small shear strain level are well correlated with N-values of the standard penetration test, and that their interrelation may be expressed by a simple, approximate Eq. G = 1200N 0.8 (tons/sq meter) regardless of soil types and depths from the ground surface.
TL;DR: In this paper, the relation between tsunamis and sea bottom deformations associated with the Kurile Islands earthquake of 1969 and the Tokachi-Oki earthquake of 1968 is studied on the basis of a fairly complete set of seismological and tsunami data.
TL;DR: In this paper, the propagation characteristics of MHD fast-mode disturbances, which can emanate from flare regions, are computed for realistic conditions of the solar corona at the times of particular flares.
Abstract: The propagation characteristics of MHD fast-mode disturbances, which can emanate from flare regions, are computed for realistic conditions of the solar corona at the times of particular flares. The path of a fast-mode disturbance is determined by the large-scale (global) coronal distributions of magnetic field and density, and can be computed by a general raytracing procedure (eikonal equation) adapted to MHD. We use the coronal (electron) density distribution calculated from daily K-coronameter data, and the coronal magnetic field calculated under the current-free approximation from magnetograph measurements of the photospheric magnetic field. We compare the path and time-development of an MHD fast-mode wavefront emitted from the flare region (as calculated from a realistic model corona for the day of the observed Moreton wave event) with actual observations of the Moreton wave event, and find that the Moreton wave can be identified with the rapidly moving intersection of the coronal fast-mode wavefront and the chromosphere (as hypothesized in our previous paper); the directivity (anisotropic propagation), as well as other characteristics of the propagation of the Moreton wave can be successfully explained.
TL;DR: In this paper, a geometrical classification of all fibres in pencils of curves of genus two is given, which is essentially different from the numerical one given by Ogg ([11]) and Iitaka ([7]).
Abstract: This article contains geometrical classification of all fibres in pencils of curves of genus two, which is essentially different from the numerical one given by Ogg ([11]) and Iitaka ([7]). Given a family π:X→D of curves of genus two which is smooth overD′=D−{0}, we define a multivalued holomorphic mapT
π fromD′ into the Siegel upper half plane of degree two, and three invariants called “monodromy”, “modulus point” and “degree”. We assert that the family π is completely determined byT
π, and its singular fibre by these three invariants. Hence all types of fibres are classified by these invariants and we list them up in a table, which is the main part of this article.
TL;DR: A statistical analysis was made of the structures of 95 proteins of known sequence belonging to 13 families of erystallographically known conformations, with the object of predicting helices, loops and β-structures, showing that the contribution of residue pairs separated by one residue is the most important.
TL;DR: Electric stimulation of the flocculus produced a prominant depression in the inhibitory vestibulo-ocular reflex pathway to the VIth nucleus, while the excitatory pathway was free of any similarflocculus inhibition.
Abstract: Intra- and extra-cellular responses were recorded with glass microelectrodes from motoneurons in the VIth cranial nuclei of anesthesized rabbits. VIth nucleus motoneurons were identified by their antidromic activation from the VIth nerve. In these motoneurons stimulation of the ipsilateral VIIIth nerve produced IPSPs with disynaptic latencies (mean and S.D., 1.08 ± 0.1 msec) while stimulation of the contralateral VIIIth nerve produced EPSPs with disynaptic latencies (mean and S.D., 1.20 ± 0.18 msec). Correspondingly, direct stimulation of the ipsilateral medial vestibular nucleus (MV), produced IPSPs with monosynaptic latencies (mean and S.D., 0.61±0.15 msec) while direct stimulation of the contralateral MV produced EPSPs with monosynaptic latencies (mean and S.D., 0.61±0.09 msec). Further, with the recording electrode placed within the VIth nucleus to observe the extracellular potentials corresponding to the intracellularly recorded IPSPs and EPSPs, the medulla was systematically tracked with a monopolar stimulating electrode. It was demonstrated that the inhibitory relay cells could be effectively stimulated in the rostral half of the ipsilateral MV and the excitatory relay cells in the rostral half of the contralateral MV.
TL;DR: Ant-gathering was seen during the time when chimpanzees usually take a rest between the two intensive feeding periods of a day, implying that ant-g gathering by use of tools is a kind of luxury.
TL;DR: The procedure for biological and chemical detection of trichothecene-type mycotoxins and its application to the screening of Fusarium for toxic strains were described.
Abstract: The procedure for biological and chemical detection of trichothecene-type mycotoxins and its application to the screening of Fusarium for toxic strains were described
TL;DR: In this article, the authors developed formulas for calculating spectroscopic amplitudes for emission or transfer of α-particles in the framework of the harmonic-oscillator shell model with SU(3) classification.
TL;DR: In this article, anisotropy of the effective hole masses makes the molecular binding energies much larger than evaluated by using the geometrical means of the hole masses, and the line shape is analyzed by taking account of the broadening due to elastic collision.
TL;DR: How depolarisation of the T system causes the release of calcium from the sarcoplasmic reticulum (SR) is the least understood process in excitation-contraction coupling in skeletal muscle.
Abstract: How depolarisation of the T system causes the release of calcium from the sarcoplasmic reticulum (SR) is the least understood process in excitation-contraction coupling in skeletal muscle. One of the possibilities suggested1 is that depolarisation of the T system may somehow cause a potential change across the SR membrane which, in turn, induces the release of calcium. If this is actually the case, it should be possible to release calcium by directly akering the membrane potential of the SR itself in the appropriate direction.
TL;DR: SHR is characterized by an elevated sympathetic tone after severance of the right or bilateral splanchnic nerves, and the difference in arterial pressure between SHR and NCR was no longer significant.
Abstract: In spontaneously hypertensive rats (SHR) and normotensive control rats (NCR) anesthetized with pentobarbital sodium, first the right and then the left splanchnic nerves were cut. After arterial pressure had stabilized at a new lower level following each cut, the peripheral cut end of the nerve was stimulated electrically with a train of square pulses of 10V-5 msec, to determine the frequency needed to restore the level of arterial pressure before the severance (equivalent stimulation frequency, ESF). ESF is assumed to represent the average discharge rate of sympathetic vasoconstrictor fibers in the splanchnic nerve. ESF's were significantly higher in SHR than in NCR, being 3.4±2.5/sec vs. 0.67±1.63 for the right splanchnic nerve and 3.7±1.1/sec vs. 0.86±0.52 for the left splanchnic nerve (each mean with SD, n=9). Thus SHR is characterized by an elevated sympathetic tone. After severance of the right or bilateral splanchnic nerves the difference in arterial pressure between SHR and NCR was no longer significant.
TL;DR: No α1-antitrypsin could be detected in the serum of a 24-year-old man with advanced pulmonary emphysema by agarose electrophoresis, immnuno-electrophoreis, double diffusion in agaroses gel, or α1 -antitypsin genetic typing by a combination of starch-gel electrophorsis and crossed antigen-antibody electrophysis.
Abstract: No alpha(1)-antitrypsin could be detected in the serum of a 24-year-old man with advanced pulmonary emphysema by agarose electrophoresis, immnuno-electrophoresis, double diffusion in agarose gel, or alpha(1)-antitrypsin genetic typing by a combination of starch-gel electrophoresis and crossed antigen-antibody electrophoresis. A circulating alpha(1)-antitrypsin inactivator could not be demonstrated. Evidence was obtained in family members of genetic transmission of this new alpha(1)-antitrypsin variant.