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Showing papers by "Hokkaido University published in 1974"


Journal ArticleDOI
01 Apr 1974-Talanta
TL;DR: It was shown that fe(III) is effectively masked by fluoride, and the pH of the solution to be masked should be below 2.5 in order to prevent acceleration by the fluoride of aerial oxidation of Fe(II).

849 citations


Journal ArticleDOI
TL;DR: In this paper, the generation of strong acid sites was observed on the binary oxide, TiO2-SiO2, which was obtained by a coprecipitation method.

234 citations


Journal ArticleDOI
20 Sep 1974-Nature
TL;DR: This work describes the first success with artificial maturation of eels by hormonal treatment, using developing eggs collected by a trawl for young fish in suspected spawning grounds of eELs.
Abstract: THE life history of the eel is complex and despite many investigations little is known about its embryonic development. Some investigators such as Grassi and Calandriccio (1896: cited in ref. 1) and Fish1, described the supposed early development of eels, using developing eggs collected by a trawl for young fish in suspected spawning grounds of eels. The time of fertilisation of these eggs, however, was unknown, and the species involved was uncertain. Artificial maturation of eels by hormonal treatment is another approach which has been attempted by many workers2–6. They all, however, failed to obtain mature eggs and sperm and thus to clarify the embryonic development of eels. Here we describe the first success with this approach.

226 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the Virasoro-Shapiro model contains Einstein's theory of gravity as a zero-slope limit, and that the conventional dual model contains the scalar electrodynamics as a zeroslope limit.
Abstract: It is shown that the Virasoro-Shapiro model contains Einstein's theory of gravity as a zero-slope limit. It is also shown that the conventional dual model contains the scalar electrodynamics as a zero-slope limit. The connection between the generating functionals for the scattering matrices of these dual models and the corresponding field theories is demonstrated.

208 citations


Journal ArticleDOI
TL;DR: A major role had been played by centric fission as well as fusion, translocation, and pericentric inversion in birds to elucidate mechanisms involved in certain structural changes of macrochromosomes observed in birds.
Abstract: Karyotypes were compared in 48 species, including 6 subspecies, of birds from 12 orders: Casuariiformes, Rheiformes, Sphenisciformes, Pelecaniformes, Ciconiiformes, Anseriformes, Phoenicopteriformes, Gruiformes, Galliformes, Columbiformes, Falconiformes and Strigiformes. — With the exception of the family Accipitridae, all the species studied are characterized by typical bird karyotypes with several pairs of macrochromosomes and a number of microchromosomes, though the boundary between the two is not necessarily sharp. The comparative study of complements revealed that a karyotype with 3 morphologically distinct pairs of chromosomes is frequently encountered in all orders except the Strigiformes. Those 3 pairs, submetacentric nos. 1 and 2, and a subtelocentric or telocentric no. 3, are not only morphologically alike but also have conspicuous homology revealed by the G-banding patterns. Furthermore, G-banding analysis provided evidence for the derivation of the owl karyotype from a typical bird karyotype.—The above cytogenetic features led to the assumption that the 3 pairs of marker chromosomes had been incorporated into an ancestral bird karyotype. It seems probable that those chromosomes have been transmitted without much structural changes from a common ancestor of birds and turtles, since the presence of the same marker chromosomes in the fresh water turtle Geoclemys reevesii is ascertained by G-banding patterns. — A profile of a primitive bird karyotype emerged through the present findings. Hence, it has become possible to elucidate mechanisms involved in certain structural changes of macrochromosomes observed in birds. It was concluded that a major role had been played by centric fission as well as fusion, translocation, and pericentric inversion.

200 citations


Journal ArticleDOI
TL;DR: Lipoprotein I appears to be the major neutral lipid and sterol transport agent in the insects studied and, in addition, plays a regulatory role in the release of both diglycerides and sterols.

190 citations


Journal ArticleDOI
TL;DR: The steady-state flow method has been widely used in the kinetic study of heterogeneous catalysis as mentioned in this paper, and it is a common practice for the investigator to postulate a number of suspected rate models and then to assess these models to verify a optimal one which best fits observed rate data.
Abstract: The steady-state flow method has been widely used in the kinetic study of heterogeneous catalysis. Under the conditions of steady state, all elementary steps in series are progressing at the same rate and hence the measured rates hardly tell the precise kinetic structure, or mechanism, of catalytic reactions which usually consist of several elementary steps including adsorption of reactants, surface reaction, and desorption of products. In the kinetic analyses of any given reactions, it is a common practice for the investigator to postulate a number of suspected rate models and then to assess these models to verify a optimal one which best fits observed rate data. Usually, however, there are quite a large number of plausible rate models even for a rather simple reaction, and it is not easy to determine the most adequate model among others even with the help of mathematical model indentification techniques with a electronic computer. This method is based on the assumption that there is a best mode...

176 citations


Journal ArticleDOI
TL;DR: In this article, an experimental investigation is made of the effect of surface roughness on the statistical distribution of image speckle intensity, which is formed by spatially coherent light at the image plane of an object having some roughness and its statistical properties are investigated.

133 citations


Journal ArticleDOI
01 Nov 1974-Nature
Abstract: A statistical geometrical argument is presented which could, as the basis of a more refined calculation, help to give a statistical geometrical answer to the question of what random packing is.

116 citations


Journal ArticleDOI
Nobuo Takagi1
TL;DR: The two X chromosomes of female mouse cells in early cleavage stages showed the same characteristic banding pattern as that observed in the X chromosome from adult male fibroblasts, and it was not until the 9th day of gestation that the late-labeling X predominated, as in adult cells.

114 citations


Journal ArticleDOI
TL;DR: It was possible to picture simple models showing structural relations between five oxidation-reduction states of peroxidase.

Journal ArticleDOI
TL;DR: An enzyme which hydrolyzes the acetamido groups of N-acetylglucosamine residues in chitin was partially purified from Mucor rouxii and accounts for the formation of chitosan in fungi.

Journal ArticleDOI
TL;DR: In this article, the effect of solution pH on the passive film on iron was investigated by ellipsometry and by cathodic reduction combined with chemical analysis, and the transition layer model of the film was proposed to explain the results.

Journal ArticleDOI
TL;DR: Amberlite XAD-2 was used to extract bile acids from urine or diluted serum of patients with hepatobiliary diseases and sulfated bile acid fraction obtained from urine revealed several spots with R(F) values different from those of the taurine or glycine conjugates.

Journal ArticleDOI
Norio Sato1, K. Kudo1
TL;DR: In this paper, the anodic passivation of nickel was compared with that of iron in terms of thickness of the surface film as a function of potential and the film thickness as estimated by ellipsometry increases linearly with rise of the potential.

Journal ArticleDOI
TL;DR: In this article, it has been shown that the active species of MgO and CaO for the ester formation are the metal benzylates whose formation is facilitated by both the basic sites (O2−) and acidic sites (Me2+) on the surface.

Journal ArticleDOI
TL;DR: The two specimens revealed a close similarity also in some other physicochemical, chemical and immunological properties.
Abstract: Alpha-fetoprotein of the rat was immunochemically purified and characterized. Mouse α-fetoprotein, which cross-reacts with antibodies to rat α-fetoprotein, was also purified. Rat α-fetoprotein was heterogeneous in disc electrophoresis and isoelectric focusing and had two different isoelectric points at pH 4.76 and 5.05. Mouse α-fetoprotein was homogeneous when analyzed similarly. The molecular weight of both rat and mouse α-fetoprotein was 70,000 as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. The two specimens revealed a close similarity also in some other physicochemical, chemical and immunological properties. Purification et Caracterisation Chimique de L'α-Fœtoproteine de Rat et de Souris L'α-fœtoproteine de rat a ete immunochimiquement purifiee et caracterisee. L'α-fœtoproteine de souris, qui a des rections croisees avec les anticorps contre l'α-fœtoproteine de rat, a egalement ete purifiee. L'α-fœtoproteine de rat est heterogene, comme l'indiquent l'electrophorese en gel d'acrylamide et le reperage du point isoelectrique, et elle a deux points isoelectriques differents a pH 4.76 et 5.05. Les měmes analyses ont montre que l'α-fœtoproteine de souris est homogene. Le poids moleculaire des α-fœtoproteines de rat et de souris est de 70 000, comme on l'a determine par electrophorese en gel en presence de dodecyle sulfate de sodium. On a egalement constate chez les deux specimens une etroite ressemblance du point de vue de quelques autres proprietes physicochimiques. chimiques et immunologiques.


Journal ArticleDOI
TL;DR: In this paper, the effect of spatial coherence of the illuminating light on the contrast variations of the image speckle intensity distribution is theoretically evaluated under various statistical conditions of the diffusing object.

Journal ArticleDOI
TL;DR: Suspension-cultured cells of sycamore which were immersed in liquid nitrogen after prefreezing to the temperatures from -30 to -50 C in the presence of dimethylsulfoxide and glucose as cryoprotective additive could proliferate vigorously when rewarmed rapidly in water at 40 C.
Abstract: Suspension-cultured cells of sycamore (Acer pseudoplatanus L.) which were immersed in liquid nitrogen after prefreezing to the temperatures from -30 to -50 C in the presence of dimethylsulfoxide and glucose as cryoprotective additive could proliferate vigorously when rewarmed rapidly in water at 40 C. For maintaining high viability of the cells after immersion in liquid nitrogen, it seems to be essential to use the cells at the later lag phase or the early cell division phase. This study provides a possibility for long term preservation in liquid nitrogen of plant-cultured lines.


Journal ArticleDOI
TL;DR: In tomato plants the source exceeds the sink and the young developing vegetative organs, such as the apex of the stem or the lateral buds, do not consume a large amount of photosynthates because these are capable of photosynthesizing from early stages of development.
Abstract: In tomato plants the source exceeds the sink. This conclusion is arrived at from the following facts: (a) The net assimilation rate Increases by a partial removal of leaves and decreases by a partial or complete removal of fruits, and (b) the young developing vegetative organs, such as the apex of the stem or the lateral buds, do not consume a large amount of photosynthates because these are capable of photosynthesizing from early stages of development. Except for several leaves at the base of the stem which send their photosynthates to the roots, a tomato plant is composed of several units, each of which is composed of three leaves, a truss and a bud, This unit is the source-sink unit and the photosynthates of the leaves of a unit go preferentially to the sinks within the unit. However, this source-sink unit is not an absolute one. There is an inter-units translocation of photosynthates and the extent of it depends on the condition of the plant.

Journal ArticleDOI
TL;DR: The degradation of phosphatidylcholine during freezing appears to be intimately associated with freezing injury, particularly in the cortical tissues of less hardy poplar.
Abstract: A striking degradation of phosphatidylcholine into phosphatidic acid was observed in the cortical tissues of less hardy poplar (Poplus euramericani cv. gelrica), when the tissues were frozen below a lethal temperature. No change in phospholipids was detected during freezing or even after thawing in the cortical tissues of hardy poplar which survived slow freezing to −30 C or even immersion in liquid N2 after prefreezing to −50 C. The degradation of phosphatidylcholine during freezing appears to be intimately associated with freezing injury.

Journal ArticleDOI
TL;DR: The results indicate that toad eggs acquire the full ability, without any influences from the oviduct, both to react to a penetrating sperm and to prevent polyspermy.
Abstract: The jelly-less coelomic eggs of the toad, Bufo bufo , even if chromosomally mature and reactive to parthenogenetic stimuli, are not fertilized or fertilized in a low frequency under the conditions which assure the sperm entry into dejellied uterine eggs. A high frequency of fertilization was obtained, however, when coelomic eggs from which the vitelline membrane had been digested away by pronase or hatching enzyme were inseminated in the presence of polyvinylpyrrolidone (PVP) or the diffusible egg-jelly component. Experimental evidence is presented to show that the conditions important for inducing this success in fertilization are the complete removal of the vitelline membrane and insemination in the presence of one of the following sperm ‘capacitating’ substances: the diffusible jelly component, the non-dialysable jelly component, PVP, dextran, or Ficoll. Fertilization obtained by this method was monospermic, as defined both by cytological examination and by the mode of early cleavage. However, the eggs invariably ceased development at the gastrula stage, because of the lack of the mechanical support normally provided by the egg envelopes. These results indicate that toad eggs acquire the full ability, without any influences from the oviduct, both to react to a penetrating sperm and to prevent polyspermy. When eggs undergoing maturation (premature eggs) were demembranated and inseminated in the presence of PVP, they did not show a genuine cleavage. Cytological examination proved the occurrence of highly polyspermic fertilization in these premature eggs, together with a tendency for the rate of pronucleus formation by the incorporated sperm to increase as the eggs were closer to the stage of full nuclear maturity. On the basis of these results, a possible role of the oviduct in affecting the vitelline membrane-egg surface interrelationship is discussed, as well as the changing reactivity of maturing oocytes to spermatozoa, and vice versa.

Journal ArticleDOI
TL;DR: The third Kurayosi explosion was fired by the Research Group for Explosion Seismology on November 21, 1970 in order to detect the seismic waves reflected from deep crustal boundaries as discussed by the authors.
Abstract: The third Kurayosi explosion was fired by the Research Group for Explosion Seismology on November 21, 1970 in order to detect the seismic waves reflected from deep crustal boundaries. Very clear reflected waves from the Conrad discontinuity were recorded by the instrument for seismic prospecting (E.T.L. recorder). There was also weak indication of the reflection from the Mohorovicic discontinuity in the records obtained at closely spaced temporary observation points equipped with FM data recorders at the shot distance of about 100km. On the basis of these results, a revision was made for the previous model. The crustal thickness obtained is about 35km and the Pn velocity, about 7.8km/sec.

Journal ArticleDOI
TL;DR: The surplus of photosynthates of young, upper leaves is considered to depress the photosynthetic activity of old, lower leaves, and this is a conceivable reason for the rapid decline of photosynthesis activity of a leaf with age.
Abstract: The apparent photosynthetic rate at 70 klux of a leaf attains a peak (33-46 mg CO2-dm-3.hr-1) at a very early stage of its development, decreases rapidly, and then maintains a low constant value (5mg CO2.dm-3.hr-1). The photosynthetic rate is positively correlated with the content of nitrogen, phosphorus, chlorophyll and starch, and is negatively correlated with the content of calcium, manganese, silicon, and moisture. However, the physiological significance of these correlations is doubtful. The photosynthetic potential exceeds the requirement of the sink as a whole plant. The surplus of photosynthates of young, upper leaves is considered to depress the photosynthetic activity of old, lower leaves. This is a conceivable reason for the rapid decline of photosynthetic activity of a leaf with age. A low but constant photosynthetic rate (5mg CO2.dm-3.hr-1) of old leaves at later stages is due, most probably, to a gradual increase in the weight of these leaves. The leaves lower than L6 are considered...

Journal ArticleDOI
TL;DR: The He 1 photoelectron spectrum of hydrogen peroxide is reported in this paper, showing a splitting of 1.0 eV between the first two bands due to the oxygen nonbonding orbitals.

Journal ArticleDOI
S. Matsui1
TL;DR: Findings strongly suggest the existence of ribosomal gene-specific non-histone proteins which probably represent the structural chromatin element rather than the primary gene product in mammalian and marsupial chromosomes.

Journal ArticleDOI
TL;DR: In the tomato plant nutrient absorption is continuous and the net assimilation rate is kept almost constant at 6–7 g.m-2.day-1 throughout growth, so the biological and economic yields are equivalent to those of cereal crops.
Abstract: In the tomato plant nutrient absorption is continuous and the net assimilation rate is kept almost constant at 6–7 g.m-2.day-1 throughout growth. The biological and economic yields are equivalent to those of cereal crops. Except for a few leaves at the base, a tomato plant is composed of several units which consist of the stem and three leaves (the vegetative organs), and a truss (the reproductive organ). Vegetative and reproductive growth occur simultaneously. The reproductive growth does not compete with the vegetative growth for nutrient elements or photosynthates because the growth of fruits is achieved by using currently absorbed or produced substances. The photosynthetic potential of the leaves seems to exceed the requirement of growing organs, and the leaves generally continue to grow even when the fruits are developing rapidly.