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Summary The effect of varied levels of nitrate on the absorption of atmospheric nitrogen dioxide (NO2) by sunflower (Helianthus annus L.) plants was investigated by using a 15N dilution method. Growth of the plants was greatest at 5 mM nitrate, with less growth at 15 mM nitrate and a considerable reduction at zero nitrate. The total amount of NO2-nitrogen absorbed by the plant depended on the plant size and total leaf area. Nitrate supply did not influence the rate of absorption of NO2 by the plants when exposed to 0.3 μl l−1 NO2. On the contrary, when the plants were exposed to 2.0 μl l−1 NO2, the absorption rate was significantly lower for the plants grown at zero nitrate compared with those grown at 5 or 15 mM nitrate. The lower rate of NO2 absorption in the nitrate-deficient plants was not due to the changes in stomatal resistance or stomatal density of the leaves, but could have been due to an increase in mesophyll resistance resulting from accumulation of high levels of nitrite in the leaf tissues. Nitrogen dioxide at 0.3 μl l−1 exerted a nutritional effect on the nitrate-deficient plants, while NO2 at 2.0 μl l−1 acted as a toxic air pollutant on the plants at all the levels of nitrate supplied.

Changes in muscular potentials at medial gastrocnemius (MG) muscles induced by prolonged stimulation at 5 Hz were compared in dystrophic mice and their normal littermates at various ages. A rapid and notable reduction in the amplitude of muscular potentials at MG muscles was observed in normal mice. This was in contrast with a slight decrease or even an increase in the amplitude in dystrophic mice. The magnitude of reduction in normal mice increased with age, but in dystrophic mice where the change (a decrease or even an increase) was slight, it was similar in extent regardless of age. The slight change in dystrophic mice under the present regimen would be called a fatigue, resistant-like property, and this was discussed in conjunction with analogous properties observed in electrophysiological, histological and biochemical fields.

A regeneration process of plant communities following disturbance of a pine forest in Tsukuba region in Japan has been studied. Bare ground was established by clear-cutting a red pine plantation and after that natural regeneration of plant communities starting from bare soil was observed by taking multi-spectral aerial photographs. Based on the photographic data, year-to-year changes in patterns of regenerating plant communities were described and the process was analyzed by a Markovian model. The model represents a point-to-point replacement process from one year to the next among different plant communities. We found that following clear-cutting of a red pine plantation, bare soil was rapidly revegetated by plant communities. We have also found that the point-to-point replacement process was a non-stationary Markovian process. This result suggests that patterns and processes of invasion of pioneer plants into the bare soil at the initial stage would primarily affect the following revegetation process.

Utilizing a new blood-analysis method which uses the interaction between an Ar + laser beam and a blood sample, it can be shown that there is a significant difference in the reflectance variation δ R between the malignant and benign blood, at 501.7 nm of the Ar + laser, under a dc magnetic field, for both human and mouse blood. For the malignant mouse-blood with leukaemia, δ R tends to be positive with the magnetic field, while for the benign blood it is negative. This is also true for the human blood. This fact is confirmed by the inverted variation of the higher order Fourier pattern obtained by the Fourier pattern analyser from the transmitted beam through the diluted sample, for the malignant and benign mouse-blood under the magnetic field.

Emphases in JT-60 experiments are placed on (1) lower-hybrid (LH) current drive characteristics with a multi-junction type launcher, and (2) the confinement study with combination of neutral beam injection LH current drive and pellet injection. The new multi-junction LH launcher provides a sharp N/sub /// spectrum with high directivity for N/sub ///=1-3.4. The current drive efficiency and the radial distribution of high energy electron production show clear correlation with injected N/sub ///: the current drive efficiency has the maximum at low N/sub ///( approximately 1.3) while flattening of plasma current is more effective in large N/sub ///. A broad radial distribution of high energy electron current and approximately 30% reduction in sawtooth inversion radius were obtained by high N/sub /// ( approximately 2.5) LH injection. To fully suppress the sawtooth activity, low N/sub /// ( approximately 1.3) injection was found to be more effective. Improved energy confinement has been obtained with hydrogen pellet injection. Energy confinement time was enhanced up to 40% relative to usual gas fuelled discharges. The discharge has a strongly peaked electron density profile with ne(0)/(ne) approximately 5 and ne(0) approximately 2.0*1020 m-3. The improved discharges are characterized by a strongly peaked pressure profile within the q=1 magnetic surface, and degrades when a large sawtooth recovers or the pressure gradient may reach a critical value. When large (3 mm, 4 mm) and fast (2.2 km/s) pellets were injected, 30% energy confinement improvement was obtained even during the NB heating of 14 MW. Further investigations of IDC characteristics have been made. The oxygen impurity lines from the main plasma and the main radiative loss drop first. Then the plasma stored energy starts to rise. The particle recycling is reduced around the main plasma, and is localized in the neighborhood of the X-point with a time lag of approximately 0.2 sec. Eventually the discharge shows a significant remote radiative cooling power at the divertor region.

Sunflower Helianthus annuus L. and maize Zea mays L. plants in the vegetative phase were exposed to nitrogen dioxide (NO2) at 0·0 (control), 0·2, 0·5 and 1·0 ppm (μl litre−1) for 2 weeks. The growth responses of the plants to NO2 were examined by the techniques of growth analysis. The sunflower plant was more susceptible to NO2 than tha maize plant. Exposure to NO2 at 0·2 ppm slightly stimulated the growth of the sunflower plants. The net assimilation rate (NAR) was also significantly increased when the plants were exposed to 0·2 ppm NO2. Exposures to NO2 at 0·5 ppm or more significantly reduced the dry weight of the sunflower plant. Of the component parts, the roots and stems were severely affected, while the leaves were less affected. This resulted in an elevated shoot/root ratio. The net assimilation rate of both species was reduced by the exposures to NO2 at 0·5 ppm or more, while, in contrast, the leaf area ratio (LAR) was increased. The relative growth rate (RGR), the product of the NAR and the LAR, was therefore less affected by NO2. The increase in the LAR was overwhelmingly the result of an increase in the leaf weight ratio (LWR). These results imply that a reduction in photosynthetic efficiency induced by NO2 could be, in part, compensated for by an increase in assimilatory area, suggesting an adaptive growth response of the plants to air pollutant stresses.

Initial ohmic heating experiments in JT-60 were performed for a three month period of April-June 1985. A maximum plasma current of 1.6 MA was obtained for both divertor and limiter discharges. Low-q discharges of qeff=2.5 and high density discharges of 4.8*1019 m-3 in line-averaged density were obtained in the divertor configuration. In divertor discharges radiated loss from the main plasma can be kept at 20-30% of the ohmic input.

This paper describes the central control system of the JT-60 tokamak. This control system not only has to organize plasma operation, but also has to utilize devices under isolated operation. Therefore the control system has been designed in a special way.

Summary A quantitative tracer experiment was conducted to elucidate the effects of continuous exposure to ozone (O3) at 0.2 μl 1−1 on the translocation and the distribution of 13C-labelled photosynthetic assimilates from the individual source leaves in 14-d-old plants of Phasealus vulgaris. The amount of labelled assimilates exported from the primary leaf, which acted as a main source of photosynthates for growth of the roots, decreased remarkably in the presence of O3 as a result of both a considerable reduction of 13CO2 fixation (62%) and the inhibition of translocation. On the other hand, that from the first trifoliate leaf, which mainly nourished the immature growing leaves, was not decreased in the same way by O3 because a smaller reduction of 13CO2 fixation (24%) was almost compensated by an acceleration of translocation. The pattern of assimilate distribution was altered by O3, so that a greater proportion of assimilates was partitioned to the growing leaves at the expense of the root and the stem. Consequently, the amount of labelled assimilates translocated to the non-photosynthetic organs (stem and root) decreased by 53 %, while that to the photosynthetic organs (leaves) was reduced by only 28%. These results suggest that the plants might have adapted themselves to an environment containing O3 so that the reduction of growth efficiency caused by O3 could be minimized.

SUMMARY Absorption of nitrogen dioxide (NO2,) by eight herbaceous species was determined by the 15N dilution method. The plants were continuously exposed to NO2, at 0.5 μll−1 for 2 weeks. Susceptibility to NO2, was simultaneously examined in the tested species to see if this was correlated with the rate of absorption. The total amount of NO2-nitrogen absorbed by a plant during the 2-week exposure period primarily depended on the size of the plant. Among the tested species, sunflower showed the highest rate of NO2, absorption per unit leaf area, reaching as much as 0.55 mg N dm −2 d−1, which was about four times greater than that for sorghum which had the lowest rate. A highly significant correlation was observed between the rate of absorption and the stomatal conductance among the species. A proportion of the NO2-nitrogen accumulated in the plant might be absorbed via the air-soil-root route. Sunflower and radish which had higher rates of NO2 absorption than the other species were more susceptible to NO2. On the contrary, sorghum and maize which showed a lower rate of NO2, absorption were tolerant. Consequently, the higher susceptibility to NO2 of radish and sunflower is considered to be directly related to their superior ability to absorb NO2.

Summary The 15N dilution method was used for the quantitative estimation of nitrogen dioxide (NO2) absorbed by Helianthus annuus and Zea mays during a relatively long period. The relationships between the amount of NO2 absorbed and the concentration of NO2 and length of exposure were investigated, in order to ascertain the reliability of this method. The total amount of NO2-nitrogen absorbed by the plants over two weeks (from two to four weeks after the sowing) increased with increasing concentrations of NO2. The rate of absorption of NO2 per unit leaf area also increased linearly with increasing concentrations of NO2 from 0 to 1 μl l−1. This means that the diffusive resistances of stomata or mesophyll tissues were not changed by the continuous exposure to NO2 at 1 μl l−1for two weeks. The absorption rate per unit leaf area in H. annuus was about three times greater than that in Z. mays. The total amount of NO2-nitrogen absorbed by the plants which were continuously exposed to 0.5 μl l −1NO2 rose not linearly but exponentially as the exposure time increased from zero to three weeks. This might in part have reflected the growth characteristics of the plants, since dry weight and leaf area increased exponentially during the period of exposure to the pollutant. The absorption rate per unit leaf area remained constant during the first two weeks, but thereafter increased significantly, probably due to the uptake of NO2-nitrogen through the air-soil-root pathway. These results demonstrated that the values estimated by the15N dilution method were reliable, and this method can be recommended for the quantitative determination of NO2 absorbed by plants during a long period.

Time courses of changes in muscular potentials to repetitive stimulation at 5 Hz for 10 min were compared between rat medial gastrocnemius (MG) and soleus (SOL) muscles. Stimuli were applied to a sciatic nerve near the entrance of the MG and lateral gastrocnemius (LG) muscles and its exit segment from the LG to the SOL muscles. Muscular potentials were generally evoked in the form of a biphasic wave at the MG muscle and were always of a simple biphasic pattern at the SOL muscle. It was found that, due to prolonged stimulation, muscular potentials were rapidly and notably reduced in the MG muscle, whereas they were gradually facilitated in the SOL muscle. This contrast was similar to differences in the time course of changes in muscular potentials under these conditions in the MG muscle of dystrophic and littermate normal mice.

Essential divertor functions — density and energy control — have been investigated in the JT-60 divertor with metal walls. Neutral pressure in the divertor chamber increases in proportion to n2e and high recycling state for particle exhaust is realized. At ne ≤ 6 × 1019m−3, wall pumping by the divertor plates is dominant in particle exhaust. However, at ne ≥ 6 × 1019m−3, particle exhaust by active divertor pumping systems becomes essential. Because of the effectiveness of the divertor, radiation loss in the main plasma is reduced to 5–10% of the absorbed power and impurity concentrations are significantly suppressed at very low level (Zeff = 1.5-2.0). In the experiments with graphite walls, short periods of H-mode phases were found in the outside X-point divertor discharges although improvement in energy confinement is limited to within 10%. In limiter discharges, combination of high vessel temperature (210–300 °C) and low current limiter discharges (1.5 MA) without gas puffing is effective as a wall conditioning in obtaining reproducible high density discharges. The maximum parameters, Ip = 3.2 MA, ne = 1.2 × 1020m−3, qeff = 2.2 at Bt = 4.8T, a Murakami parameter of 7.5, and a stored energy of 3.1 MJ have been attained. The maximum density is limited by the occurence of the MARFE. During high power neutral beam heating, enhanced carbon influx was observed possibly due to chemical sputtering. The wall pumping by the inner wall is still effective in decreasing the electron density from the high density region of ne ~ 1 × 1020m−3. An empirical energy confinement scaling of JT-60 has been drawn in terms of an offset linear function as τE = 0.19 I1.9PPabs + 0.062 a1.8p

From June to October 1987, JT-60 achieved fusion product (ne(0). tau E*.Ti(0)) of 6*1019 m-3.keV.s with hydrogen plasma at plasma current of 2.8 to 3.1 MA with neutral beam power of approximately 20 MW. The central electron density of 1.3*1020 m-3 was obtained at plasma current of 3 MA with 13 approximately 20 MW neutral beam power and the confinement time reached 0.14-0.18 s. An offset linear scaling law like the Shimomura-Odajima scaling on confinement time will be able to reproduce experimental data better than that of the Goldston type scaling. With low beam energy injection approximately 40 keV, confinement degradation was found. Many short periods (0.05 approximately 0.1 s) of H-mode phase were found in outside X-point divertor discharges with NB or NB+RF(LH or IC) heating power above 16 MW. However, improvement in energy confinement time was limited to 10 %. The ballooning/interchange stability analyses were also made for the outside X-point divertor equilibrium in connection with H0-phase capability. Heating powers of 9.5 MW and 1.9 MW were obtained by LHRF, ICRF injection, respectively. In combined LHRF and NB heating, the incremental energy confinement time of 0.064 s was obtained, which is the same level of that of NB heating only. In combined NB and on-axis ICRF heating of low ne discharge, an incremental energy confinement time of 0.21 s was obtained, which is three times as long as those of NB or ICRF heating only. High energy beam ions were accelerated by ICRF in the central region of the plasma.

In the last year, ohmic heating experiments were performed in JT-60 for about three months; May–June 1985 and March 1986. The major experimental effort has been concentrated on the divertor configuration in anticipation of H-mode operation of JT-60 in high power supplementary heating experiments starting in August 1986. Stable discharges with a divertor have been obtained at Ip = 1.85 MA and ne = 5.7 × 1019m−3. Radiated power from the main plasma in divertor discharges is reduced to one third of that in material limiter discharges. The electron density has a broad radial profile and the effective safety reaches qeff = 2.5. The neutral gas pressure in the divertor chamber becomes significantly high and the control of particle recycling has been attempted.

Muscular potentials were evoked by electrical stimulation of sciatic nerves and recorded from gastrocnemius muscles in dystrophic and normal mice. When frequency of stimulation was accelerated from 0.5 to 5 per sec and continued, the potentials were depressed to a notable extent in normal mice, whereas only a slight decrease or even an increase in them was observed in dystrophic mice. Thus, a simple method has been developed to differentiate pre- and/or postjunctional properties for impulse transmission in dystrophic mice from those in normal mice.

Time courses of changes in medial gastrocnemius (MG) and soleus (SOL) muscle potentials induced by repetitive stimulation at 5 Hz were studied using Wistar strain rats. Particular interest was focussed on the changing pattern of SOL potentials in old rats as compared with that in young ones. Contrary changing patterns of SOL potentials were found in young and old rats. SOL potentials were rapidly reduced to respective plateau levels in old rats while they were gradually potentiated in young ones when 5 Hz stimulation was given for 10 min. Moreover, the pattern obtained from middle aged rats fell between those of the two age-groups.

Glycosaminoglycans were isolated from the skeletal muscle of either normal or dystrophic mice aged from 3 to 18 weeks. The glycosaminoglycan content of the normal muscle, based on the tissue weight, decreased slightly during the period from 3 to 10 weeks, and remained almost unchanged after 10 weeks. The major glycosaminoglycan in normal muscle was hyaluronate, the relative amount of which increased slightly (from 70% to 80%) with age. Both dermatan sulfate and heparan sulfate were also obtained. The relative amounts of these sulfated glycosaminoglycans tended to decrease with age. On the other hand, the glycosaminoglycan content of the dystrophic muscle was higher than that of normal muscle even at 3 weeks. The proportion of hyaluronate was almost constant (about 65%) throughout the age range examined. The relative amount of dermatan sulfate increased from 20% to 30% with a compensatory decrease in the amount of heparan sulfate. Further, the incorporation of [35S]sulfate into glycosaminoglycans by the dystrophic muscle was reduced to about 60% of the normal. These differences in glycosaminoglycan composition and [35S]sulfate incorporation between the normal and the dystrophic muscles may be related to the progressive muscular dysfunction seen in this disease.

1-alpha-(3,4-Dimethoxyphenethylaminomethyl)-2-hydroxybenzylalcohol 1/2 fumarate (TA-078) is a new hypoglycemic agent structurally different from any existing hypoglycemic drug. It depresses the rise of blood glucose when it is orally administered to glucose-loaded mice, rats and beagle dogs at minimal doses of 1, 10 and 2.5 mg/kg, respectively. In contrast with tolbutamide, TA-078 hardly affected fasting blood glucose levels in rats and dogs and only weakly reduced fasting blood glucose levels in mice. Oral administration of TA-078 to KK mice also improved glucose tolerance, while no improvement was observed in streptozotocin-diabetic rats. TA-078 elevated plasma immunoreactive insulin (IRI) levels in mice and rats soon after its oral administration. In fasted rats, TA-078 caused only a transient increase in plasma IRI but did not affect plasma immunoreactive glucagon (IRG) levels in the early phase after its administration. On the other hand, tolbutamide induced a sustained increase in plasma IRI and a transient but marked decrease in plasma IRG. In perfused rat pancreas, TA-078 stimulated insulin secretion. The stimulation by 10 micrograms/ml TA-078 in the perfusion liquid required the presence of a normal concn (5.6 mM) of glucose, whereas the same concn of tolbutamide stimulated insulin release even at a low glucose concn (2.8 mM).