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The pluripotential cell-specific gene Nanog encodes a homeodomain-bearing transcription factor required for maintaining the undifferentiated state of stem cells. However, the molecular mechanisms that regulate Nanog gene expression are largely unknown. To address this important issue, we used luciferase assays to monitor the relative activities of deletion fragments from the 5'-flanking region of the gene. An adjacent pair of highly conserved Octamer- and Sox-binding sites was found to be essential for activating pluripotential state-specific gene expression. Furthermore, the 5'-end fragment encompassing the Octamer/Sox element was sufficient for inducing the proper expression of a green fluorescent protein reporter gene even in human embryonic stem (ES) cells. The potential of OCT4 and SOX2 to bind to this element was verified by electrophoretic mobility shift assays with extracts from F9 embryonal carcinoma cells and embryonic germ cells derived from embryonic day 12.5 embryos. However, in ES cell extracts, a complex of OCT4 with an undefined factor preferentially bound to the Octamer/Sox element. Thus, Nanog transcription may be regulated through an interaction between Oct4 and Sox2 or a novel pluripotential cell-specific Sox element-binding factor which is prominent in ES cells.

Hyperaccumulators are essential for phytoremediation of heavy metals. In Europe and North America, many studies have been conducted to find more effective plants for phytoremediation of various pollutants. In Japan, this field of research has just recently come more into focus. A type of fern in Japan, Athyrium yokoscense, is well known as a hyperaccumulator of Cd and Zn. However, it is not suitable for phytoremediation because it is a summer green and grows slowly. Therefore, in order to find hyperaccumulators other than from A. yokoscense, we surveyed plants growing at polluted sites in Japan. We found that the Brassicae Arabis gemmifera is a hyperaccumulator of Cd and Zn, with phytoextraction capacities almost equal to Thlaspi caerulescens.

In order to enhance the adhesion strength of copper metal film to a polyimide (PI) film substrate, a method combining surface microroughness formation and imide ring cleavage was investigated. The results showed that imide rings were cleaved with a KOH treatment while carboxyl and amide groups were formed on the surface of the PI film. The surface micro-roughness did not change with the KOH treatment, and the adhesion strength of the copper metal film to the PI film was slightly improved to 30 g/mm, which could be attributed to the interaction of both carboxyl and amide groups with the copper atoms. When the PI films were successively treated with an alkaline permanganate and a KOH solution, many recesses were formed on the surface in an alkaline permanganate solution, and the size and depth of the recesses increased with alkaline permanganate treatment time. The results of the AFM measurements showed that the average roughness (R) increased from 3.54 to 10.23 nm after combined treatment with alkaline per...

SUMMARY Automatic steering control algorithm has been proposed, which uses the motion of objects in a visual image (Optical Flow) obtained from an ITV camera looking ahead in the situation without forward vehicles. This algorithm is improved to be applicable to the situation in which the forward tracking course is invisible owing to the interfarence of the forward vehicles. The adjustment of the control parameters against the change in vehicle speed is confirmed by the computer simulation experiments.

Band gap structure of C60 epitaxial film is reported by using AC- photoconductivity measurement. The measurement clarify gap states by analyzing spectra two components of photocurrent and phase shift. A bias operation through semi-transparent Au electrodes has verified existence of Schottky barrier of about 2V. The temperature dependence of the spectra indicate that tail states correspond to structure change of C60 at around 250K.

The effect of Bacillus licheniformis HA1 cell density on the acceleration of organic waste composting was tested in a bench-scale composting system utilizing a process limit temperature of 60°C. Variables measured during composting were CO2 evolution rate, conversion of substrate carbon and pH. When an initial cell density of 2.0×104 cfu/g-dry solid was used, the strain HA1 increased in number and prevented the decrease in pH during the early stage of composting. This resulted in enhanced populations of other thermophiles and increased the rate of organic matter decomposition. By contrast, no effect was observed at a lower cell density of HA1. It was found that the minimum cell density of HA1 to accelerate organic decomposition was around 104-105 cfu/g dry solid of raw material.

Recently, nylon-11 and nylon-7 have been found to be ferroelectric and this ferroelectricity was related to hydrogen bonds between polymer chains. When the crystal structure of nylon-11 is complete and has little disordered structures, the ferroelectricity is difficult to be exhibited because of the fairly strong network of the hydrogen-bonding system. The ferroelectricity is obtained for nylon with the slightly disordered crystal structure. This was confirmed by measuring the vibrational frequency for the N-H bond stretching. For the nylon with the disordered crystal structure, the vibrational frequency was found to shift to the higher wavenumber, indicating the loosening of the hydrogen-bond in question. In the present paper, we calculate the vibrational frequency for the N-H bond stretching by using ab initio molecular orbital method in order to shed light on the relation between the degree of the disorder of the crystal and the magnitude of the shift of the vibrational frequency. In connectio...

Efficacy of various compost starter cultures was tested in a bench-scale composting system utilizing a ceiling process temperature of 60°C. Variables tested with time were CO2 and NH3 evolution, conversion of carbon and the succession of microorganisms in the compost. When an initial compost pH of 7.0 was used, a laboratory produced starter culture (Culture A) was much less effective than a commercial culture (Culture B). Low activity in the experiment with Culture A was due to a low pH(

Suppressive effect of ten kinds of composts on four phytopathogenic fungi was investigated in vitro. Four of them showed an inhibitory effect on fungal growth. Bacteria which were associated with the effect were isolated and identified as Bacillus subtilis. Suppressiveness of the culture broth of the bacteria was investigated using other phytopathogenic fungi in vivo and the broth showed a broad suppressive spectrum. When the bacteria were inoculated into a thermophilic composting reactor for sewage sludge, they survived and the suppressive property was maintained. When degree of suppressiveness of the compost samples collected at each stage of the composting operation from two composting plants was compared, only well-matured composts were found to suppress the phytopathogens.

Squeezed fluid of pig manure and bonito processing wastewater, and their effluents from methane fermentation were studied in pot experiments in a model case of land application of organic wastewaters with high strength and low C/N ratio. Kanagawa alluvial soil (upland soil) and Kagoshima volcanic ash soil (upland soil) were used. The stabilization period of these four wastewaters in Kanagawa soil determined by gel chromatography was 14 days for an effluent from methane fermentation of bonito processing wastewater (EMB), 21 days for an effluent from methane fermentation of squeezed fluid of pig manure (EMP) and bonito processing wastewater (BPW), and 28 days for squeezed fluid of pig manure (SPM). Stabilization of all wastewaters occurred 1 week later in the Kanagawa soil than in the Kagoshima soil. In spite of apparent stabiliza- tion, inhibition of the growth of a 72 h seedling of Komatsuna (Brassica campestris L. var. rapiferafroug) was observed in EMB due to the accumula- tion of N02-N especia...

This comment relates recent mine closures and layoffs to the fall in metal prices beginning in 1997. Both regional differences in mine closures, and the incidence of mine closures and layoffs by me...

Longitudinal liquid mixing in a concurrent multistage bubble column partitioned by perforated plates was observed by means of the thermal tracer technique. The mixing characteristic was expressed by combining the backflow through the plate and the dispersion in each stage. The backflow ratio of liquid through plate κ, which was defined by the ratio of backflow rate to the net flow rate of liquid, was independent of plate spacing and column diameter, and was affected by gas velocity uG, liquid velocity uL, free area of plate Ar, hole diameter of plate d0, plate thickness δ and liquid viscosity μ. The values of κ are empirically correlated with uG, UL, Ar, do, δ and μ. The dispersion coefficient in stage was smaller than that in the bubble column without partition plate.

In order to investigate the degradation or synthetic process of organic matter in soil, some instrumental analyses on the water extract from soil have been recently performed. SCHAUMBERG et al. (1) who observed the changes in the chemical nature of water-soluble components of sewage sludge-soil mixtures by using infrared spectroscopy, supplied valuable information on the fate of sludge organic components in soil. The authors reported (2, 3) that the stabilization process of sewage sludge in soil can be monitored by the conventional gel chromatography method with Sephadex G-15 in water extracts from sewage sludge-soil mixtures. The previous works (2, 3) showed that macromolecular compounds which cannot be separated by Sephadex G-15 gel were present in the water extracts from sewage sludge-soil mixtures. High performance size exclusion chromatography (HPSEC) offers the possibility to estimate the molecular size distribution of such macromolecules, because HPSEC allows rapid size separation and high resoluti...

The movement of solid particles through the partition plate was investigated in a multistage bubble column with continuous flow of liquid containing suspended solid particles. A mathematical model for use in predicting the solid concentration difference through the partition plate was derived on the basis of theoretical consideration of factors controlling the flow of liquid with suspended solid particles through the plate. Using experimentally observed data of solid concentration distribution in gas and slurry cocurrent upflow multistage bubble columns of 10 and 20cm in diameter, model parameters governing the solid concentration difference through the partition plate were correlated with the operating conditions. The transition of solid concentration profile within the column from a stepwise distribution at zero and/or low liquid flow rate, to a sawtoothed one at high liquid flow rate was interpreted by applying the model. From observed values of the gas holdup, the slip velocity of gas against liquid in the multistage bubble column was also correlated with the operating conditions.

The effects of gas velocity and geometrical dimensions of apparatus on the flow rate QL of circulating liquid, gas holdups and pressure drops in bubble columns with draught tube were examined. It was found that QL increases with increasing gas velocity, column diameter, draught tube length, and height of the lower end of draught tube, and decreases with increasing liquid viscosity. It was also found that the maximum value of QL is observed for constant values of gas velocity and column diameter, when the diameter ratio of draught tube and column is about 0.6. Empirical equations for gas holdups in draught tube and annulus and the pressure drops due to flow reversals, necessary for estimating QL, are proposed.

The deep shaft has been recently developed as an aeration device to meet high oxygen demand in liquid. The authors reported previously on the result of analyzing operational characteristics of the air-lift type deep shaft aerator. A similar analysis was carried out for the liquid-pump type shaft, in which liquid circulation between the downcomer and the riser parts in the shaft is maintained by a liquid pump. As results of the mathematical model simulation, the operating condition which gives a stable liquid circulation, and the optimal power economy condition, which yields the maximum capability of oxygen transfer to liquid per unit power consumption, are made clear. Though the power economy is a little lower than that in the air-lift type shaft, more flexible and stable operations can be expected with the liquid-pump type shaft under varying conditions of oxygen demand in liquid.

Effects of the sludge loading rate, soil properties, dewatering agent in sludge, and incubation temperature on the stabiIization period of dewatered sewage sludge in soil were investigated with reference to the gel chromatographic patterns of the water extracts from the soil-sludge mixtures. The stabiIization period was defined as the period until which a specific pattern of the gel chromatogram appears, indicating both the presence of small amounts of free ammonia and the accumulation of nitrate nitrogen in soil. A high sludge loading rate above 5% resulted in a longer stabilization period, especially in the Fujimi loamy coarse sand soil. The stabiIization period was shorter in the Hiratsuka coarse sandy loam soil than in the other two kinds of soils (Fujimi loamy coarse sand soil and Sekiya fine sandy loam soil). Lime, used as a dewatering agent, shortened the stabiIization period at low sludge loading rates, but prolonged it at high sludge loading rates, compared with a polymeric organic coagulant. Tem...

The flow scheme and oxygen transfer were quantitatively investigated for the gas-liquid downflow system. Experiments were carried out on a pilot-scale column, 45 cm in inner diameter and 6 m high. The slip velocity of gas bubble swarm against liquid phase was correlated with gas holdup and bubble diameter, and thus conditions giving stable downward flow of completely segregated gas bubbles were specified. The fraction of oxygen absorbed into liquid phase was observed under stable bubble flow conditions. Much higher volumetric oxygen transfer coefficients in the present system than those in the conventional upflow system were obtained. This was attributed to the high values of gas holdup, even up to 20%, in the present system. It is suggested that the present system could be applied as a promising aeration device utilizing enriched oxygen gas.

An aeration system employing a long vertical shaft of 100 m or more depth has recently been developed by ICI. The interior of the shaft is divided into two parts. Air bubbles sparged in one side of the interior flow down to the bottom and then flow up through the other side of the shaft to the surface, as liquid circulates through both sides. This liquid circulation is maintained by the gas lift action of the sparged air. In this aeration system, the flow path of the air bubbles introduced is long enough to yield high oxygen utilization. In the present paper, the authors discuss operating problems of ICI''s deep shaft aerator. The airlift type deep shaft was simulated by a mathematical model. The momentum balance equation for the fluid flow, the theoretical and empirical relations between gas velocity, liquid velocity, gas slip velocity and gas holdup, and the mass balance equation for oxygen transferred through the gasliquid interface, were all simultaneously solved to obtain the distributions of gas holdup and oxygen utilization along the shaft length. The calculated results give valuable information, such as the relations between the gas velocity, liquid circulation velocity, depth of air introduced and oxygen utilization. The power economy of the deep shaft is discussed in connection with its design and operating problems.

The purpose of this paper is lo investigate a transformation of systems in a category theoretic way and to reveal its structural property by showing that the famous Nerode realization and a well known stationarization operation are concrete realizations of the transformation. There is a well-known stationarization operation which transforms a lime variant tlynamicul model given by z =ƒ(t,z,.x) and y = g(t,z,) into a time invariant dynamical model ([udot],z)= (l.ƒ(u,z,x)) and y=g(u,z) where x, y and z are, respectively, an input, an output and a state variable. The paper integrates the Nerode realization and the above stationarization operation by one transformation and shows that they yield minimal causal stationary models using the category-theoretic treatment of the transformation. The paper demonstrates that the category theoretic consideration is powerful in integrating diversified systems concepts and in disclosing their underlying structures. In particular, a certain structural property of a station...

For monitoring the decomposition process of various organic wastes with different C/N ratios in soil, the applicability of gel chromatography of the water extract was investigated. The organic wastes were classified into two groups A and B, according to the characteristic gel chromatogram patterns of water extracts from fresh organic wastes. It was confirmed that these two groups exhibited different patterns of nitrogen transformation when they were incorporated into soil. When organic wastes in Group A with relatively low C/N ratios were incorporated into soil, the chromatograms recorded at UV 280 nm wavelength changed from pattern I to II and then to pattern III, and indicated a stabilized state of organic matter in soil due to the nitrification of ammonium. When organic wastes in Group B with relatively high C/N ratios were incorporated into soil, nitrogen immobilization occurred in the early stage of incorporation and pattern II persisted for a long period. The nitrogen transformation was more accurat...

This paper treats causal ordering in the framework of mathematical general systems theory. Due to its importance causal ordering has been much discussed, however, it has not hitherto been formulated as a system theoretic property. This paper formulates causal ordering as one of the proper system theoretic properties that should be characterized only by the behaviour of a system. In particular, for a general system S given by a binary relation over system objects X ajnd Y. we say there exists a causal ordering from X to Y if X is non-trivially related to Y and if it is possible to decompose S into a class of functional subsystems where each functional subsystem expresses a determinism from events of X to events of Y such that an event of Y occurs after an event of X. Based on this formulation, Simon's, symmetry problem of causal ordering, that is the mterehangeability problem of a cause and an effect, is considered. Characterizations of symmetry and asymmetry of causal. ordering are given for basi...

Growth of komatsuna (Brassica Rapa var. pervidis) was studied on Fujimi sandy soil treated with garbage composts of different maturity using Neubauer's pot under artificial light and controlled temperature. Inhibitory effect on komatsuna growth was evaluated by comparing the growth in the compost treatments with that in inorganic nutrient treatments with the same amount of inorganic nitrogen as in the composts. Under a loading of 10 g dry weight per pot, which is equivalent to 10 dry ton of compost per 1 ha in land application, the treatment with immature composts resulted in considerably lower yields compared with the controls. Inhibitory effect was observed especially in the early stages of growth. The well-mature composts gave higher or equal yields compared with the controls. On the other hand, with a loading of 20 g per pot, all the compost treatments resulted in lower yields than those of the controls regardless of compost maturity. The inhibitory effect was mainly observed in the later stages of gr...

The emulsion copolymerization of acrylonitrile and styrene was carried out. The rate of reaction, the number of polymer particles and the compositions of copolymer were determined experimentally under various initial monomer concentrations, volume fractions of monomers and emulsifier concentrations. A mathematical model of this copolymerization system, in which one monomer is hydrophilic and the other is hydrophobic, has been derived based on the assumptions that the reaction takes place inside polymer particles and that there exists a partition equilibrium of acrylonitrile between the aqueous and the oil phases. The Lewis-Mayo equation was modified by the introduction of the parameter B, the ratio of concentrations of two monomers in polymer particles. It was shown that B is a function of a, the partition coefficient of acrylonitrile, and the monomerwater phase ratio. The Lewis-Mayo equation was solved numerically, and the calculated results coincided well with the observed ones.

The effects of the water extracts of rapeseed cakes undergoing decomposition under different conditions on plant growth were evaluated using Lemna paucicostata 6746 for the bioassays. Half-strength Hutner’s medium was used as the basal medium, to which aliquots of concentrated water extracts were added in the ratio of 1/1,000, and the number of reproduced fronds were counted after 7 days as an index of the growth. Aerobic decomposition of rapeseed cake (1:1 ratio of rapeseed cake to water, w/w) showed a strong inhibitory effect on the growth of L. paucicostata 1 to 4 weeks after the start of the decomposition. In the submerged decomposition (1 : 10 ratio of rapeseed cake to water, w/w), no inhibition was detected in the first weeks, but a strong inhibition appeared after 8 weeks and increased thereafter. The water extracts of the rapeseed cake undergoing decomposition under the submerged condition contained large amounts of fatty acids (acetic, propionic, and butyric acid), which were considered to be the...

On montre que lorsque l'ecoulement turbulent de recirculation du liquide predomine dans la colonne, la vitesse de glissement apparente differe de la vitesse moyenne relative entre le gaz et le liquide. Correlation exprimant la vitesse de glissement apparente en fonction de la retenue de gaz

The stabilization processes of sewage sludge composts with different degrees of maturity, which were incorporated into a coarse sandy loam soil under a rather intensified loading rate of 5% in dry weight, were investigated during their incubation at 25°C. In the immature compost-soil mixtures, ammonification, decrease of nitrate concentration, and/or accumulation of nitrite were observed in the early stages of incubation and followed by nitrification. In the mature compost-soil mixtures, only nitrification was observed during the incubation. These nitrogen transformations were wen correlated with the transitions of characteristic patterns; I, II, and III of gel chromatograms of the water extracts. The redox potential decreased appreciably in the immature compost-soil mixtures in the early stages of incubation and increased in the later stages, when pattern III of the chromatogram was observed. When sludge composts became stable in soil, as shown by the chromatographic pattern III, the values of pH and NH4...

Experimental studies of the continuous emulsion polymerization of stylene were made for the purpose of examining the consistency of the authors'' theory proposed previously1). Two kinds of seeders, a plug flow type and a backmixed type, were employed prior to the main reactor to analyze the formation of polymer particles, separately from their growth. Although the number of polymer particles obtained experimentally was less than that of the theoretical value due to the presence of a small amount of impurities introduced continuously in the system, the experimental results agreed well qualitatively with those predicted from the theory.

The average diameter, d, of bubbles generated from a porous plate in pure liquid and in aqueous solutions of inorganic electrolyte were measured at various gas flow rates by taking photographs of bubbles the size of which was controlled by bubble coalescence on and above the plate. For the extreme case when coalescence occurred at the maximum rate such as in water and in pure organic liquid, the empirical equations for d based on previous data and those from this experiment are proposed. The addition of inorganic electrolyte to water reduced the coalescence and thus simultaneously reduced d. The average bubble diameter in the aqueous solutions is well correlated to the experimental conditions with an empirical equation including the non-dimensional group proposed by Marrucci and also corresponding to the controlling factor of the bubble coalescence.

The rate of emulsion polymerization of styrene over the entire range of monomer conversion in isothermal batch operations was measured, with changing monomer to water phase ratio, types of emulsifiers and their concentrations and initiator concentration. The rate of reaction was separately analyzed in three reaction region, such as the induction, the zero-order and the first order reaction region. The rate expressions for each reaction region and for acceleration effect on the rate were obtained. Predicted values by these expressions agreed well with the experimental data. The theory proposed by Smith and Ewart on the mechanism of the formation of polymer particles was also ascertained.

In concurrent bubble columns the longitudinal mass and thermal dispersion coefficients were determined. The both coefficients agreed well with each other. This shows that the mechanism of the thermal dispersion in the bubble column is also governed by liquid mixing. The dispersion coefficient El, is correlated with experimental conditions in three regions, which are classified by the value of slip velocity of gas bubbles, us. At us>25cm/sec, El obtained in columns of the same diameter is related apparently only on the superficial gas velocity in the column, but it is independent on the liquid property and the size of gas bubbles. El is also proportional to one and a half powers of the column diameter. At us us > 25cm/sec, no correlation for El was obtained.

The behavior of suspended solid particles in the bubble column was experimentally studied. The critical gas velocity for complete suspension of solid particles is affected by liquid flow near the gas distributor. The liquid flow is governed by the shape of the bottom of the column and the position of the gas distributor. On the other hand, gas bubbles rising through the column develop easily to large bubbles by the existence of a small amount of suspended solid particles, and therefore the gas holdup and the concentration distribution of the particles do not depend on the gas distributor and the shape of the bottom of the column. The dispersion coefficient of solid particles has the same value with that of liquid within the column without solid particles. The settling velocity of solid particles in the bubble column was correlated with the terminal velocity of those particles in stagnant liquid.

The rate of emulsion polymerization of acrylonitrile has been investigated under widely variable experimental conditions such as initiator concentration, emulsifier concentration and monomer-water ratio. The results obtained were interpreted reasonably well by kinetic equations, which were proposed by assuming that the reaction in polymer particles proceeds under the slow termination regime and that the surface of polymer particles alone plays a role in propagation.

The change in number of polymer particles formed in the continuous emulsion polymerization of styrene under operational conditions is theoretically analyzed on the basis of the authors'' kinetic data, previously obtained in a batch reactor. The phenomenon of the limit cycle observed in this continuous system is explained. It is noted that the application of "the seeder" to formation of polymer particles will be recommended in practical operations.

The effect of agitation on the reaction rate of emulsion polymerization of styrene was experimentally studied. The agitation intensity in preparing the emulsion affects the polymerization rate. This is because the amount of soap molecules adsorbed on monomer droplets decrease the number of soap micells which produce polymer particles in the induction reaction region. Once the emulsion is prepared in a specified condition, the agitation intensity during reaction does not affect the polymerization rate. The amount of soap adsorbed on monomer droplets was estimated from the reaction rate in the zeroorder region by assuming Smith and Ewart''s theory, and was correlated empirically with the surface area of monomer droplets at the moment of emulsion preparation.

In a fixed bed it was ascertained that the rate of catalytic hydrogenation of ethylene on Nicatalyst was approximately expressed by either the first or the second-order equation, respectively, for two different feed compositions of the reactants. The same reaction was carried out in a packed-fluidized bed in which glass spheres or cylindrical wire nets were used as packing materials. The results showed that the conversion of ethylene was correlated solely with Lmf/uf and was independent of the fluidizing condition. The concept of contact efficiency will be used to express the performance of the reaction in a packed fluidized bed.

Emulsion polymerization of styrene with soap concentration chosen in the vicinity of critical micelle concentration (CMC) has been investigated. The rate of polymerization and the number of polymer particles correlated with initial monomer, soap and initiator concentrations, are explained qualitatively. An analysis of the gel effect observed at later stage of the reaction has been also carried out. The accumulation of polymeric radicals in polymer particles is considered to be due to the decrease in the termination rate constant kt as monomer conversion increases. An empirical equation for kt as a. function of viscosity in polymer particles is derived.

On the basis of a one-dimensional dispersion model, which was applied by Imafuku et al. to interpret the behavior of suspended solid particles in a bubble column, a procedure for obtaining the age distribution and the spatial age distribution of the particles in a continuously operating bubble column was developed.

It is illustratively shown that the approximate method of estimating the catalyst effectiveness factor, previously presented by the authors, is widely applicable in general cases and also that the nonisothermal effect within the catalyst on the effectiveness factor is minor.