Search

A new database system for the JT-60SA tokamak has been developed. This system meets the following requirements: to hold all the JT-60SA data and prevent loss of data, to allow researchers to use data without knowing internal database configuration and structure, to manage data revision so that stored data can be traced back to the older revision anytime. Depending on the timing of data transfer for storage or reference, the experiment data are categorized into three types: (i) discharge data, (ii) plant monitoring data, and (iii) unprocessed data. In the first step in constructing a new database system, we have designed the basic structure of the JT-60SA database system to manage all three data types. The dedicated tools for data transfer or retrieval prevent unregistered computers from accessing the experiment data. The RAID6 configuration of a hard disk drive (HDD) and the magnetic tapes improve data reliability. This paper reports details about the functions of the new JT-60SA database system. Furthermore, the elapsed time of data transfer and storage is measured to evaluate the performance of the JT-60SA database system. It takes 20 s to transfer and store 6 GB of data, which is enough to meet the required performance.

The ITER Remote Experimentation Centre (REC) project (one of the three sub-projects of the International Fusion Energy Research Centre (IFERC)) is progressing under the agreement between the Government of Japan and the European Atomic Energy Community for the joint implementation of the Broader Approach (BA) activities in the field of fusion energy research. The objectives of the REC activity are to identify the functions and solve the technical issues for the construction of the REC for ITER at Rokkasho, and to develop the remote experiment system and verify the functions required for remote experimentation by using the Satellite Tokamak (JT-60SA) facilities to facilitate the future exploitation of ITER and JT-60SA. The functions of REC will be tested, and the total system will be demonstrated using JT-60SA and existing facilities in the EU, such as JET and WEST. The hardware of the REC has been prepared in Rokkasho Japan, which has the remote experiment room with a large video wall to show the plasma and operation status, IT equipment and a storage system by the reuse of the Helios supercomputer tape library. A broadband network infrastructure of 10Gbps has been installed connected to SINET5. Using this network system, fast data transfer from ITER to REC was examined in 2016, and the transfer of the data volumes expected for the initial ITER experiments has been demonstrated. A secure remote experimentation system has been developed, using JT-60SA, that has functions for preparing and setting of shot parameters, viewing the status of control data, streaming of the plasma status, data-exchange function of shot events, and monitoring of the facility operation. Remote data analysis techniques, data visualisation software, a documentation management and experiment planning system and numerical simulation codes for the preparation and performance estimation of discharges have also been developed.

The JT-60 operations were stopped in 2008 in order to be upgraded to a superconducting tokamak device, JT-60 Super Advanced (JT-60SA). The design activity of JT-60SA is going on under the ITER-BA p...

In collaboration with the Naka Fusion Institute of Japan Atomic Energy Agency (NFI/JAEA) and the National Institute for Fusion Science of National Institute of Natural Science (NIFS/NINS), Center for Computational Science and E-systems of Japan Atomic Energy Agency (CCSE/JAEA) aims at establishing an integrated framework for experiments and analyses in nuclear fusion research based on the atomic energy grid infrastructure (AEGIS). AEGIS has been being developed by CCSE/JAEA aiming at providing the infrastructure that enables atomic energy researchers in remote locations to carry out R&D efficiently and collaboratively through the Internet. Toward establishing the integrated framework, we have been applying AEGIS to pre-existing three systems: experiment system, remote data acquisition system, and integrated analysis system. For the experiment system, the secure remote experiment system with JT-60 has been successfully accomplished. For the remote data acquisition system, it will be possible to equivalently operate experimental data obtained from LHD data acquisition and management system (LABCOM system) and JT-60 Data System. The integrated analysis system has been extended to the system executable in heterogeneous computers among institutes.

The design activity of JT-60SA (JT-60 Super Advanced) addresses the remodeling of JT-60 to a superconducting tokamak device under the JA-EU collaborative ITER–BA project. For the JT-60SA control system, the existing system should be reused as much as possible from the viewpoint of cost-effectiveness. Initial considerations of the configuration of the advanced supervisory control system (SVCS) including the following systems are: (1) an ultimate flexibility real-time control system, (2) a precision timing system able to diagnose a plasma event having a time range of ∼1 μs, and (3) a safety shutdown control system. In this report, we present the design study of the JT-60SA SVCS with the focus on the above systems.

For safety and efficient operation of a fusion device, appropriate information should be provided to the personnel participating in the experiment. In a continuing effort to meet this requirement, we have recently developed highlight displays showing the plasma movie, the status of the discharge sequence, the discharge schedule, the status of present troubles, etc. These highlight displays are presented on the large (65 in.) TV monitor in front of the central consoles. These displays are automatically changed according to the timing signals of the JT-60 discharge sequence and/or at the JT-60 session leader's request. We call this system “the supervisory discharge operation monitoring system.” This report describes the technical details of both this system and the discharge information management system (DIMS).

Since remote participation in ITER experiments is planned, it is expected to demonstrate that the JT-60SA experiment is controlled from a Japanese remote experiment center located in Rokkasho-mura, Aomori-ken, Japan as a part of the ITER-BA project. Functions required for this experiment are monitoring of the discharge sequence status, handling of the discharge parameter, checking of experiment data, and monitoring of plant data, all of which are included in the existing JT-60 Man–Machine Interfacing System (MMIF). The MMIF is now only available to on-site users at the Naka site due to network safety. The motivation for remote MMIF is prompted by the issue of developing and achieving compatibility with network safety. The Java language has been chosen to implement this task. This paper deals with details of the JT-60 MMIF for the remote experiment that has evolved using the Java language.

In JT-60U, a mainframe computer called inter-shot processor (MSP-ISP) had been supervising the data acquisition of diagnostic subsystems, managing the storage of obtained data, and establishing communication with the JT-60U's discharge control system. But due to the increased demand for advanced diagnostics, such as improving spatial and temporal resolutions or extending the data acquisition period, the old ISP had been becoming insufficient in power and less cost effective. To resolve this problem, we have gradually migrated ISP to a new UNIX server (UNIX-ISP), and thereby carried out the decentralization of the old ISP's functionalities. Also we are developing a new mass data acquisition system (MDAS) that has simple architecture but has greater performance and flexibility. Simultaneously, to handle the increased volume of data, we are renewing the data storage system. The renewed data processing system (DPS) is now in operation. The performance of the new ISP and the newly developed MDAS is presented.

A new navigation method that decouples manufacturing processes of tailor-made products has been developed for shortening lead time. Axiomatic Design expresses manufacturing processes with two design equations; one with functional requirement (FR) of “defining process” and design parameter (DP) of “decisions in process,” and the other with FR of “predicting completion time of product” and DP of “priority of product.” Once formulated, decoupling the system with the rules of “No feedback” and “No moving up” effectively shortens lead time. Applying the navigation methodology to a real unmanned machine shop of molds, eventually shortened it from 44 to 7.7 days.

JT-60 data processing system (DPS) possesses three-level hierarchy. At the top level of hierarchy is JT-60 inter-shot processor (MSP-ISP), which is a mainframe computer, provides communication with the JT-60 supervisory control system and supervises the internal communication inside the DPS. The middle level of hierarchy has minicomputers and the bottom level of hierarchy has individual diagnostic subsystems, which consist of the CAMAC and VME modules. To meet the demand for advanced diagnostics, the DPS has been progressed in stages from a three-level hierarchy system, which was dependent on the processing power of the MSP-ISP, to a two-level hierarchy system, which is decentralized data processing system (New-DPS) by utilizing the UNIX-based workstations and network technology. At present, replacing the MSP-ISP with a UNIX-based workstation is under way as a final phase in building the New-DPS project. This replacement will be accomplished by October 2005. In addition, remote experiment in JT-60 is considered to be an important issue in extension of the collaborative research among the nuclear fusion community. Technical environments for this task have been developed. The participant from a remote site can set discharge parameters with assistance of the dedicated machine operating status-information tools.

The JT-60U control system, composed of a UNIX-based workstation and a VME-bus system, has been successfully performing advanced plasma control for the JT-60U plasma discharges. Various hardware modifications and advanced plasma control algorithms have been continuously integrated into the JT-60U control system since its upgrade in 1991. The ZENKEI, the supervisory control system, has been entirely converted from its original 16-bit minicomputers and CAMAC system to the combination of a workstation and VME-bus system linked through an Ethernet network. The plasma equilibrium control system utilizes a full VME-bus system composed of three DEC alpha CPU modules that are currently running at control cycle times of 250 μs. The parameters for plasma equilibrium control are calculated by a newly developed real-time plasma shape calculation and reconstruction system. These parameters are fed to the plasma equilibrium control system synchronized by 250-μs clock pulses. To progress toward the advanced plasma control concept, which includes adoption of a global plasma parameter control algorithm and suppression of MHD instabilities, improvements were extensively consolidated into the plasma control system (PCS). Currently, additional modifications of the JT-60U control system have extended the pulse duration of the discharge without a major change in JT-60 equipment.

The JT-60U data processing system is a large computer complex gradually modernized by utilizing progressive computer and network technology. A main computer using state-of-the-art CMOS technology c...

The old discharge control system (DCS) with HIDIC-80E mini-computer has been replaced by a control system with a unix workstation and a VME-bus system. Functionally, the workstation performs message communication with VME controller on the network, data processing using plant data and data acquisition. The commands and receiving the status data in real time. The new DCS is flexible for system extension and able to quickly respond to various requirements of software modifications. The data acquisition speed has been improved by almost a factor of two over the old one. Troubles and countermeasures experienced in the replacement work are also presented.

Remodeling of the JT-60 discharge control system (DCS) is initiated to minimize the cost and time for hardware maintenance and software development. Three principles have been adopted for remodeling. (1) The functions of the DCS must remain intact. (2) The shutdown period must be minimized to maximize JT-60 experiment time. To realize the new DCS, (3) a combination of the host workstation (WS) and target Versa Module Europe (VME)-bus system with real time OS was chosen as the fundamental structure. The prototype DCS was designed and tested to evaluate the performance of the converted discharge sequential control software modules and the message communication program. The new configuration of the DCS and procedure of smooth remodeling without shutdown is described in detail.

The double layer capacitance at the interface between a cured epoxy resin and a metal was measured by cyclic voltammetry, and the a.c. technique was applied in order to access the impedance data as a measure of adhesion to the metal. Since epoxy resin is a highly insulating material, it was ionized by partially introducing a sulfonate group into the epoxy ring for electrochemical measurements. The other part of the epoxy ring was retained for making the network polymerization. The sulfonated epoxy resin cured on an interdigitated microelectrode or a parallel plate electrode pair showed reproducible voltammograms, in which current was proportional to sweep rate. Capacitance was obtained from the a.c. impedance analysis at various temperatures, and was found to be almost constant up to the glass transition temperature. In contrast, the epoxy resin mixed with Na2SO3 showed temperature dependence of the capacitance of Arrhenius type. When the surface was contaminated with alumina powder, its capacitance decreased drastically.

A study was carried out on the low-temperature photoluminescence (PL) and PL excitation measurements of hexagonal In x Ga 1-x N microcrystals. synthesized by the nitridation of the sulfide in the In concentration range, 2% < x < 6%. The broad PL bands decomposed into the single-peak bands with the commonly observed peaks and some additive peaks. The peak energies of the single-peak bands were compared with those of the bands for In x Ga 1 -x N epilayers in previous reported results and the transitions of the selected single-peak bands were assigned to the recombination of the exciton at localized levels due to alloy disorder. The large Stokes shifts and the absorption band within a gap confirmed the luminescence center states were localized. To explain the facts that the gap energy varied for the samples with the same In content and the emission peak energy did not relate to the band gap energies, we proposed that the localized states originate from the In clusters caused by the fluctuation of the In concentration. This type of localized center provides the microscopic structures of the localized states in In x Ga 1 -x N epilayers.

Fusion performance of reversed shear discharges with an {ital L}-mode edge has been significantly improved in a thermonuclear dominant regime with up to 2.8 MA of plasma current in the JT-60U tokamak. The core plasma energy is efficiently confined due to the existence of persistent internal transport barriers formed for both ions and electrons at a large minor radius of r/a{approximately}0.7 near the boundary of the reversed shear region. In an assumed deuterium-tritium fuel, the peak fusion amplification factor defined for transient conditions involving the dW/dt term would be in excess of unity. {copyright} {ital 1997} {ital The American Physical Society}

This paper describes a novel mutant mouse that has been spontaneously derived from the Snell's dwarf (DW/J) mouse. It was named the 'growth-retarded mouse' because of a characteristic growth pause followed by the delayed onset of pubertal growth. The onset of the increase in pituitary GH content that normally occurs concomitant with pubertal growth was also delayed in the growth-retarded mice. The serum concentration of thyroxine was very low in these mice from the neonatal period through adulthood, and a supplement of tri-iodothyronine was effective in shortening the growth pause and commencing the suppressed pubertal growth. Histological and immunohistochemical studies revealed that the anterior pituitary gland of the growth-retarded mouse contains clustered unusual chromophobic cells which are not reactive to various antisera against anterior pituitary hormones and the gland becomes enlarged with age. Breeding data indicated that these characteristics of the mice show an autosomal recessive inheritance and the gene responsible was designated as 'grm'. Partial linkage analysis utilizing microsatellite polymorphism demonstrated that the grm gene does not identify with the lit or hyt genes. Based on comparison of the hormonal status and growth pattern between growth-retarded, dwarf and normal mice, we have suggested the existence of a mutual interaction, possibly positive feedback regulation, between the pituitary and thyroid glands, that develops or matures the hormonal network which is responsible for rapid somatic growth and metabolic changes at puberty in mice. Journal of Endocrinology (1994) 142, 435–446

1. Under urethane-anaesthesia, changes of spontaneous activities and evoked muscle potentials in rat medial gastrocnemius (MG) and soleus (SOL) muscles induced by the injection of neostigmine were investigated. 2. Before the administration of neostigmine, spontaneous activities were rarely observed and muscle potentials evoked by single shocks were simply biphasic in both MG and SOL muscles. When the anti-cholinesterase drug was applied, spontaneous discharges of motor units were often observed in bursts in the MG muscles, in contrast to single spikes in the SOL muscles. The biphasic wave of evoked potentials in the MG muscles was followed by one or more oscillations, which were scarcely observed in the SOL muscles. These burst discharges and oscillations in the MG muscles [corrected] also occurred even after transection of the sciatic nerve proximal to the stimulating site. 3. A late component with a small amplitude could be observed in the evoked potentials of MG and SOL muscles. It was potentiated in amplitude after the administration of the drug. 4. Prolonged action of acetylcholine (ACh) has been known to occur in the presence of anticholinesterase drugs, and this was taken into account for the mechanism of the phenomena proposed in the present study. Contrasting changes between MG and SOL muscles were observed, which may be explained by different modes of ACh release in the MG and SOL muscles.

Selenocysteine (Scy) was synthesized on natural opal suppressor tRNA(Ser) by conversion from seryl-tRNA. We studied the mechanisms of the synthesis of mammalian Scy-tRNA using hydro[75Se]selenide (H75Se-). We found Scy synthase activity in the 105,000 g supernatant of a murine liver extract. The supernatant was chromatographed on DEAE-cellulose, and the activity was eluted at 0.12 M-KCl. The reaction mixture for synthesis of Scy-tRNA contained suppressor tRNA, serine, ATP, seryl-tRNA synthetase (SerRS), HSe- and the enzyme to synthesize Scy-tRNA. These are all essential for the synthesis of Scy-tRNA. Scy in the tRNA product was confirmed by five t.l.c. systems. The conversion from seryl-tRNA to Scy-tRNA was also confirmed with the use of [14C]- and [3H]-serine. The apparent Km values for the substrates serine, tRNA, ATP and HSe- were 30 microM, 140 nM, 2 mM and 40 nM respectively. The active eluates from DEAE-cellulose contained no tRNA kinase. This result showed that Scy-tRNA was not synthesized through phosphoseryl-tRNA. ATP was necessary when Scy-tRNA was synthesized from seryl-tRNA and HSe-. Therefore ATP is used for not only the synthesis of seryl-tRNA but also for the synthesis of Scy-tRNA from seryl-tRNA. The active fraction from DEAE-cellulose was chromatographed on Sephacryl S-300, but the activity disappeared. However, the activity was recovered by mixing the eluates corresponding to proteins of 500 kDa and 20 kDa. In order to examine the binding of HSe- to proteins, a mixture of the active fraction, H75Se- and ATP was analysed by chromatography on Sephacryl S-300. The 75Se radioactivity was found at the position of a 20 kDa protein in the presence of ATP. Thus the 20 kDa protein plays a role in binding HSe- in the presence of ATP. The 500 kDa protein must have a role in the synthesis of Scy-tRNA. There are two natural suppressor serine tRNAs, tRNA(NCA) and tRNA(CmCA), in cell cytosol. The present paper shows that the suppressor tRNA fraction, eluted later on benzoylated DEAE-(BD-)cellulose, is a better substrate with which to synthesize Scy-tRNA. Thus we consider that murine Scy-tRNA is synthesized from a suppressor seryl-tRNA on the 500 kDa protein with the activated HSe-, which is synthesized with ATP on the 20 kDa protein. This mammalian mechanism used to synthesize Scy is similar to that seen in Escherichia coli.

Recent lower hybrid current drive (LHCD), and heating (LHH) experiments on JT-60 are reported. The current drive product of neRpIRF approximately 12.5*1019 m-2 MA was achieved at the LH power of approximately 4.5 MW, and the CD efficiency, the energy confinement, the global power balance and the heat load on divertor plates were investigated in high power LHCD plasmas. Nearly steady state H-mode discharges were found during LHCD with two different frequency injections. Sawtooth suppression in NB heated plasmas by LHCD have shown an improvement in confinement near the plasma center. Parametric instabilities in LH heating experiments were significantly reduced by increasing the plasma current, and the stored energy increased linearly with heating power of up to approximately 9 MW at ne approximately 7*1019 m-3 and Ip=2.75 MA. Parametric instabilities near the plasma edge in the ion heating regime were also reduced in peaked density plasmas produced by pellet injection and LH waves increased the central plasma pressure at ne(0) > 1.4*1020 m-3.

In this paper we introduce a recursive filtering method to recover the 3D articulated motion from image sequences. In recursive filtering frameworks, the quality of the results heavily depends on the choice of state variables and the determination of the process model; which models a real object whose motion is to be estimated. Our approach employs robotics dynamics into the recursive filtering framework. And the key strategy is to incorporate joint torques into the model state variables. In addition, we assumed the variations of the joint torques are Gaussian noises. We describe how to integrate dynamics equations into Kalman filters, and with the experimental results our method is shown to be effective.

The authors describe the design and initial operation of a new JT-60 (JAERI Tokamak-60) man-machine interface system built in workstations. Development of the system was stimulated by the requirements of making of JT-60 operator interface more friendly on the basis of the past five years of operational experience. Eleven Sun/3 workstations and their supervisory minicomputer HIDIC V90/45 are connected through the standard network, Ethernet. The network is also connected to the existing ZENKEI minicomputer system through the shared memory on the HIDIC V90/45 minicomputer. Improved software, such as automatic setting of the discharge conditions, consistency check among the related parameters, and easy operation for discharge result data display, provides the user-friendly environments. This man-machine interface system leads to the efficient JT-60 upgrade operation. >

This paper describes a new image compositing algorithm that can properly blend images whose features have a high aspect ratio. Although several techniques have been used in image compositing, none of them works well for images whose features have a high aspect ratio. This compositing algorithm is a simulation on 2D projected space, of the physical phenomena of underlying 3D models. Our algorithm consists of the three steps. First, the images are composited using a multiresolution technique. Second, the features of each image are extracted. Finally, the features are overwritten to the composited image. This method makes it possible to composite hair or fur naturally.

The original control system for the poloidal field coil power supply (PFPS) in the JT-60 tokamak was developed in 1984. It was composed of CAMAC-based 16-bit microcomputers and I/Os. Corresponding to the progress in physics experiments, it had been required to improve the control system as well as to modify the power supply. Then, the control system was rejuvenated where advanced technologies of VME, networks and UNIX-workstations were applied. In addition to the upgrade of the system performance, the renewal of the control system has remarkably improved its hardware maintainability and software development environment.

Key extraction is an inverse problem of finding the foreground, the background, and the alpha value from an image and some hints. Although the chromakey solves this for a limited case (single background color), this is often too restrictive in practical situations. When the extraction from an arbitrary background is necessary this is currently done by a time consuming manual task. To solve the problem, an algorithm must address the unique requirements of the key extraction: high resolution, analytically correct alpha values, and easy human interaction. We present an image differentiation method which, for the first time, fulfills these requirements.

3D articulated motion is recovered from image sequences by relying on a recursive smoothing framework. In conventional recursive filtering frameworks, the filter may misestimate the state due to degenerated observation. To cope with this problem, we take into account knowledge about the limitations of the state-space. Our novel estimation framework relies on the combination of a smoothing algorithm with a "constraint-conscious" enhanced Kalman filter. The technique is shown to be effective for the recovery of experimental 3D articulated motions, making it a good candidate for marker-less motion capture applications.

Released acetylcholine (ACh) is rapidly hydrolyzed, and choline is recaptured and re-used as available ACh for release. This elaborated recycling process of ACh was evaluated in terms of muscle potentials evoked by a set of 10 stimuli in the presence and the absence of neostigmine using Wistar rats anesthetized with urethane. All potentials evoked by a set of 10 stimuli before the injection of neostigmine were similar in amplitude. The first potential recorded 8 min after it was as large as that before it. The second potential was greatly depressed, and others were gradually recovered to the control level. The recovery was attained in the 5th-7th potential in some rats while a slight depression of the 10th potential was still seen in other animals. This time course was a general pattern in the change of muscle potentials evoked by a set of 10 stimuli in the presence of neostigmine. When 10 stimuli were given 9 min after it, all potentials showed rather comparable amplitudes to the control level. Thus, another pattern was found. The two patterns were repeatedly observed within individuals: A striking contrast in the changing pattern was noted between successive two sets of 10 stimuli with an interval of one minute. The former set exerted an influence upon those muscle potentials evoked by the latter one beyond one minute or so, but this effect disappeared during the elapse of two minutes or more. This plastic property and other findings were discussed in conjunction with those evidences recently accumulated on the recycling process of ACh. A conjecture was made on the recycling process of ACh: The process would be activated following impulse transmission, and this activation would be maintained for one minute or so. In that sense, this process would be controlled in a 'short-term memory' manner and endocytosis of synaptic vesicles coupled with their exocytosis should be emphasized. In addition, releasable ACh would be restored during repetitive stimulation even if it was once depleted notably.

The recycling process of acetylcholine (ACh) was studied in reference to muscle potentials evoked by sciatic stimuli in the presence of neostigmine. Wistar rats around 20 days old were anesthetized with urethane. Muscle potentials were recorded with concentric electrodes from their exposed medial gastrocnemius muscles before and after the injection of neostigmine. Attention was paid to changes in muscle potentials evoked by a set of 3 stimuli, and comparison was made mainly between successive two sets. Three potentials before neostigmine treatment were similar in amplitude. When a set of 3 stimuli was delivered 8 min after it, the first potential was as large as that before it. The others were greatly depressed. The first potential evoked by a set of 3 stimuli 10 min after neostigmine treatment showed a similar amplitude to the control level. The other potentials were again reduced severely. However, none of them were depressed so much when 3 stimuli were delivered 11 min after the drug application. When two sets of 3 stimuli were given with an interval of one minute, it was repeatedly observed in all animals that muscle potentials evoked by the second set were influenced by the first set. The second potential evoked by the second set was not so much depressed as seen when the interval was two or more minutes. Thus, a striking contrast was observed between successive two sets of 3 stimuli with an interval of one minute. These results indicate that the recycling process of ACh was activated following impulse transmission in rat muscles, and suggest that there exists such a neural mechanism as can exert an influence on the process in a short-term memory manner.

Developing rats between 5 and 44 days of age as well as rats about 2 months old were anesthetized with urethane. Spontaneous activities and muscle potentials to sciatic stimuli were recorded from their exposed medial gastrocnemius muscles using concentric electrodes. Neostigmine of 0.12-0.40 mg/kg was injected into the contralateral muscles. Regardless of age, spontaneous activities were not observed and muscle potentials were evoked by single stimuli primarily in a biphasic wave (main component) before the drug treatment. Developmental differences were revealed in the presence of the drug. 1) Spontaneous activities were detected only in single spikes around postnatal 10 days. Single or double spikes were often found in rats of about two weeks. Burst discharges such as seen in adult rats were observed immediately before weaning. 2) In rats of 2 weeks or so, one or more components were observed obscurely following the main component of muscle potentials, which appeared definitely at the preweaning period. 3) When double shocks with the interval of 2 sec were delivered in the presence of the drug, the second potential was greatly depressed in rats older than two weeks as well as in adult rats. The potential was only slightly reduced in rats around 10 days. Thus, an adult pattern as to impulse transmission was observed immediately before weaning. These alterations would, at least in part, reflect the maturation of acetylcholine receptors at neuromuscular junctions.

1. The recycling process of acetylcholine (ACh) following impulse transmission was studied in terms of muscle potentials evoked by repetitive stimulation in the presence of neostigmine. 2. Wistar rats were anaesthetized with urethane and muscle potentials were recorded with concentric electrodes from their exposed medial gastrocnemius muscles before and after the injection of neostigmine. 3. All potentials before neostigmine treatment were similar in amplitude. A set of 10 stimuli was given at 0.5 Hz 6-8 min after drug administration. The first potential was as large as that before it. The second potential was greatly depressed. Thereafter, potentials gradually recovered. 4. Two sets of 10 stimuli were delivered at a 1 min interval (i.e. with a 40 s rest period between them). The second potential was not depressed so severely in the second set as in the first set. The same procedure was repeated in some rats and the aforementioned phenomenon was noted. When two sets of 10 stimuli were given at an interval of 2 min or more, the second potential was equally depressed in the both sets of stimuli. 5. The recycling of ACh following impulse transmission in the junctional region was revealed in terms of muscle potentials in the presence of neostigmine. This process was activated due to repetitive stimulation. Moreover, the activated state seemed to be maintained for a while after the cessation of stimuli. These results suggest the possible existence of a neural mechanism that can exert an influence on the recycling of ACh following impulse transmission beyond a short period of time.

This paper describes the characteristics of the luminescence centers observed in the various photoluminescence (PL) and photoluminescence excitation (PLE) spectra of hexagonal InxGa1−xN microcrystals, synthesized by the nitridation of sulfide in the In concentration range of 2%xGa1−xN, we propose the isoelectronic atom cluster model comparable with Te clusters in ZnSeTe.

The way that video and audio material is edited in post production has changed, from the so-called "traditional" editing methods, to a range of nonlinear computer based workstations. These systems offer fast access to the original data, allowing multiple versions of the same basic material to be created, and the ability to make creative and technical changes at will. The FARAD (fast random access disk) system is discussed in particular.

The in vivo responsiveness of thyroid glands to TSH at various ages in novel 'growth-retarded' (grt/grt) mice derived from Snell's dwarf (DW/J) mice and in their normal counterparts were analysed by determining serum T4 concentrations before and after the administration of exogenous TSH. The serum T4 concentration in normal mice increased in response to TSH at 2, 4 and 12 weeks of age but not at 1 week of age. A transient augmentation of such thyroidal responsiveness to TSH was apparent in normal mice at 2 weeks of age, when the serum T4 level exhibits a peak and the pubertal growth of mice starts. In contrast to normal mice, at any age examined from 2 to 12 weeks after birth, exogenous TSH did not influence serum T4 concentrations in the grt/grt mice at all. On the other hand, serum TSH concentrations in young grt/grt mice were highly elevated compared with those in normal mice and they were normalized by a 2–3 week's treatment with T3. Morphological studies demonstrated degenerated thyroid glands in the grt/grt mice. These results suggest that the severe hypothyroidism and consequent growth retardation in growth-retarded mice are due to impairment of the thyroid glands of the mutant mice in producing and/or secreting thyroid hormones in response to TSH. Journal of Endocrinology (1995) 144, 209–214

We examined whether antirheumatic drugs alter cytokine- or lipopolysaccharide-induced expression of adhesion molecules on vascular endothelial cells. Human umbilical cord vein endothelial cells were co-cultured with various antirheumatic drugs in the presence of inflammatory cytokines, and adhesion molecule expression was measured by cell enzyme-linked immunosorbent assay and Northern blot analysis. Among these antirheumatic drugs, gold sodium thiomalate significantly inhibited intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression on vascular endothelial cells and suppressed cellular binding between human monocytic cell lines, including U937 and HL-60 cells, and interleukin-1 beta-stimulated vascular endothelial cells. It is speculated that down-regulation of adhesion molecules might be one of the novel mechanisms of action of gold sodium thiomalate.

The interaction between lymphoma cells and vascular endothelial cells (EC) is the first critical step in the invasion of lymphoma cells. We found that invasive human CCRF-CEM T lymphoma cells (CEM) released a factor that upregulates the expression of adhesion molecules on vascular EC. The supernatant of CEM (CEM-SUP) increased the expression of both ICAM-1 and ELAM-1 in time- and dose-dependent manners as shown by cell enzyme-linked immunoabsorbent assay (ELISA). In contrast, the induction of VCAM-1 on EC with CEM-SUP was relatively weak. No activity for interleukin-1 alpha (IL-1 alpha), IL-1 beta, interferon-gamma (IFN-gamma), or tumor necrosis factor-alpha (TNF-alpha), which are known to augment ICAM-1 expression, was detected in CEM-SUP by ELISA. In reverse transcriptase polymerase chain reaction (RT-PCR) assay, CEM expressed a minimum amount of TNF-alpha mRNA, but absolutely no IL-1 beta or IFN-gamma mRNA. In addition, antibodies for cytokines did not inhibit the upregulatory effect of CEM-SUP. Semipurified CEM-SUP further increased the cellular binding between CEM cells and EC in vitro. This factor was stable to heat (65 degrees C, 30 minutes) and labile to acid (pH 2.0). Gel filtration and chromatofocusing estimated its molecular weight at 50 kd, with an isoelectric point of pH 7.2. Production of this factor might contribute to the invasive character of CEM through upregulation of adhesion molecules on EC.

A monoclonal antibody (McAb) specific for actin depolymerizing factor (ADF) was prepared. With this and previously prepared anti-cofilin McAb (MAB-22) and other antibodies, the expression of cofilin and ADF in the muscles of dystrophic (NH-413) chicken and dystrophic (C57BL/6J dy/dy) mice was compared with that in normal control animals by immunoblotting and immunocytochemical methods. Since cofilin expression is down-regulated during normal postnatal development of skeletal muscles [Abe et al. (1989) J. Biochem. 106, 696-702], cofilin was detected in the breast (pectoralis) muscle of normal adult chicken and the leg (femoris and tibialis anterior) muscles of normal mice only at a low level. ADF was not detectable in adult skeletal muscles. However, a significant increase of cofilin amount, but not of ADF amount, was observed in these muscles of the dystrophic animals, when the symptom of muscular dystrophy became evident. In order to localize cofilin in individual muscle fibers, serial cryosections of the dystrophic chicken muscle were examined with anti-cofilin antibody (MAB-22). The antibody stained cells of different size in the dystrophic muscle, indicating that cofilin expression was induced in the regenerating muscle cells as well as in the pre-existing myofibers. We suggest that cofilin is involved in disassembly or reorganization of actin in the dystrophic muscle.

In order to understand the pathogenesis of mouse muscular dystrophy, we investigated the levels of the thiobarbituric acid-reactive substances (TBARS), H2O2 and NADPH oxidase activity, which were relative to the acceleration of oxidative conditions, in tongue and hindleg skeletal muscles from C57BL/6J-dy mice. The TBARS content (702 nmol/g protein) in skeletal muscles from 2-months-old dystrophic mice was increased significantly over that (384 nmol/g protein) in muscles from age-matched normal mice. The H2O2 concentration in dystrophic skeletal muscles was 30% higher than that in normal ones. Microsomal NADPH oxidase activity which was related to the production of superoxide anions, was similar between dystrophic muscles (4.66 nmol/10 min/mg protein) and normal muscles (4.11 nmol/10 min/mg protein). These results indicate that oxidation is accelerated in the dystrophic muscles. However, the TBARS content in the tongues of dystrophic mice was identical to that of normal mice. This finding supports our bone-muscle growth imbalance hypothesis for the pathogenesis of mouse muscular dystrophy.

Using concentric electrodes, spontaneous activities and evoked muscle potentials were recorded from medial gastrocnemius (MG) and soleus (SOL) muscles of Wistar rats about 60 days old. When neostigmine methylsulfate was injected, spontaneous activity such as motor unit discharges occurred in a burst in the MG muscles, in contrast to few activity before the injection of this drug. In the SOL muscles, only single spikes were sometimes observed after it. In coincidence with burst discharges, some oscillations were definitely observed following the main component of MG potentials evoked by single stimuli to a sciatic nerve, whereas only slight deflections could be detected in SOL potentials. Thus, different modification of spontaneous activities and evoked muscle potentials were induced in MG and SOL muscles by the injection of neostigmine methylsulfate.

In order to gain an insight into the pathogenesis of mouse muscular dystrophy, we investigated the natural suppressor serine tRNA. The natural suppressor seryl-tRNA was distinguished from the other seryl-tRNAs on the basis of its specific property of being converted into phosphoseryl-tRNA by a tRNA kinase. On a wet-weight basis, the content of total tRNA in dystrophic muscles was 47% of that in normal muscles. Although the serine-accepting activities of tRNA were similar in muscles of 3-month-old dystrophic and normal mice, the ratio of [32P]phosphoseryl-tRNA (suppressor tRNA) to the total serine tRNA was significantly enhanced in dystrophic muscles compared with that in normal muscles. This high content of suppressor tRNA in dystrophic muscles was further confirmed by dot-blot hybridization experiments with the DNA probes CGTAGTCGGCAGGAT and CGCCCGAAAGGTGGAA for major tRNA(IGASer) and suppressor tRNA respectively. At the early postnatal age of 3 weeks, when only a week had elapsed since the first manifestation of the dystrophic symptom (hindleg dragging), the ratio of suppressor tRNA to major tRNAs in dystrophic hindleg muscles was abnormally increased. Thereafter it decreased with age in normal mice but remained almost unchanged in dystrophic mice. Consequently, at 3 months old, it was 1.7 times higher in dystrophic than in normal mice. The suppressor tRNA is now accepted to play a role in the synthesis of glutathione peroxidase. The present study showed that the content of this enzyme was abnormally elevated in dystrophic mice. Previously we had demonstrated that the docosahexaenoic (C22:6) acid content in phospholipids was decreased, possibly resulting from the enhanced oxidative milieu caused by the dystrophic condition. Thus far, the findings suggest that an increase in the contents of suppressor tRNA and glutathione peroxidase in dystrophic muscle may have been secondarily induced by such a highly oxidative state in the dystrophic condition. However, it is difficult to exclude the possibility that the natural suppressor tRNA plays a primary role in the pathogenesis of muscular dystrophies.