Pyruvate kinase isozymes in various tissues of rat, and increase of spleen-type pyruvate kinase in liver by injecting chromatins from spleen and tumor

Pyruvate kinase [EC 2.7.1.40] in various tissues of rats was separable into seven kinds of pI-isozymes by isoelectric separation with Ampholine carrier ampholytes; pI 5.4-isozyme, pI 5.6-isozyme, pI 6.2-isozyme (2 kinds), pI 6.6-isozyme, pI 7.4-isozyme, and pI 7.8-isozyme. Some of these pI-isozymes contained bound fructose 1,6-diphosphate (FDP). The bound FDP was completely dissociated when the pI-isozymes were salted out with ammonium sulfate. In the FDP-free form, pyruvate kinase was classified into three types, liver-type (type L) of pI 6.2, muscle-type (type M) of pI 7.4, and spleen-type (type M2) of pI 7.8. The liver-type isoenzyme had two kinds of FDP-binding sites; the pI 5.6-isozyme and pI 5.4-isozyme were obtained when one and two kinds of sites were bound with FDP, respectively. The association and dissociation of FDP at both sites were reversible in the presence and absence of 0.15 M KC1 (high ionic strength). The muscle-type isoenzyme had no FDP-binding site. The spleen-type isoenzyme had two kinds of FDP-binding sites, like the liver-type isoenzyme. When the ionic strength of solutions containing the enzyme and FDP was sufficiently low, one and two kinds of the sites could bind with FDP, converting the enzyme into pI 6.6-isozyme and pI 6.2-isozyme, respectively. FDP bound with one kind of site (the 2nd site) was easily dissociable, but FDP bound with the other kind of site (the 1st site) was not. Provided that the 1st site carried bound FDP, the 2nd site was associable at high ionic strength. The liver-type isoenzyme free of FDP and the spleen-type isoenzyme bound with FDP at both sites had similar pI values of 6.2 and were not separable by isoelectric separation. Some properties of these pI-isozymes were compared. When Rhodamine sarcoma was transplanted in rats, the content of spleen-type isoenzyme in the livers increased. When rats were injected with chromatin prepared from either Rhodamine sarcoma or spleen, the content of spleen-type isoenzyme in the livers again increased. This was not observed on the injection of chromatin prepared from liver, indicating that the factor capable of controlling the gene expression was present in chromatins of sarcoma and spleen but barely or not at all in chromatin of liver.     

Influence of spatiotemporal coupling induced by an ultrashort laser pulse shaper on a focused beam profile

4f pulse shapers have been widely used to temporally manipulate femtosecond optical pulses by spectral filtering. When the temporal waveform is manipulated with a spatial light modulator consisting of segmented pixels, the spatial profile of the output beam also varies because of diffraction at the pixel array, which is known as a spatiotemporal coupling effect. This effect produces a complicated spatio-temporal profile near the focus of the ultrashort pulses, which may affect the interpretation of experimental results obtained with shaped ultrashort pulses. We investigate the spatial intensity distribution at the focus of temporally shaped pulses through ablation experiments. The three-dimensional space-time beam profile is also numerically calculated.     

AI: A strategic technology in Japan?

The industrial society in Japan is now entering into a new era of an advanced information society or a network society. AI as a knowledge information processing technology is becoming an integral part of the society. This emerging era is being supported by the information industry.The Fifth Generation Computer System (FGCS) Project of Japan (ICOT, 1987) was initiated in 1982 as a part of major programme supported by Japan's Ministry of International Trade and Industry (MITI). Its objective is to develop parallel computer systems for knowledge information processing. The system is based on AI and logic programming. The Human Frontier Science Programme (HFSP, 1987), proposed by former Prime Minister Nakasone at the economic Summit held in Venice in 1987, aims at promoting basic research on human perception, cognition, and learning.This paper deals with the background of FGCS and HFSP, and the impact of AI technology on FGCS and HFSP within Japan.     

Effect of thrombin and PDGF on endothelin production in cultured mesangial cells derived from spontaneously hypertensive rats

1. Basal endothelin-1 (ET-1) production in mesangial cells of spontaneously hypertensive rats (SHR) was not different from that of Wistar-Kyoto (WKY) rats, although a trend toward increased ET-1 production was observed in these cells of SHR. 2. Thrombin and platelet-derived growth factor (PDGF) stimulated ET-1 production in a concentration-dependent manner in these cells of both rat strains, but thrombin- and PDGF-induced stimulation of ET-1 production were clearly greater in cells of SHR than WKY rats. 3. The protein kinase C (PKC)-activating phorbol ester, phorbol myristate acetate, stimulated ET-1 production in cells of both rat strains, but this stimulation was significantly greater in cells of SHR than in cells of WKY rats. 4. An inactive enantiomer of phorbol ester, 4alpha-PDD, had no effect on the ET-1 production in these cells of both rat strains. 5. Neither thrombin nor PDGF stimulated ET-1 production in PKC-depleted cells of both rat strains.     

Performance of a photomultiplier tube with transmissive dynodes in a high magnetic field

The performance of a photomultiplier tube with transmissive dynodes was examined. We found that the amplification gain was higher than 10⁴ even in a magnetic field of 7.8 kG. The energy resolution for 662 keV gamma rays from ¹³⁷Cs was 12% fwhm measured using a NaI crystal at 7.8 kG. The time resolution was as good as about 200 ps at 7.8 kG for the light generated by 2 GeV pions when they passed through a 1 cm thick scintillator mounted on the tube.     

Switched-capacitor lossless discrete differentiator with modified sample-and-hold sequence

For a design of a stray-insensitive switched-capacitor lossless discrete differentiator, a fundamental differentiator circuit and a special sample-and-hold sequence are proposed.     

Experimental study on the effect of fission product gas release into blockage wake region using a simulated LMFBR fuel subassembly

The objective of this study is to evaluate temperature rise due to gas release in the wake region of LMFBR fuel subassemblies. The experiments were conducted in two sets of grid-spacer-type 37-pin bundles simulating LMFBR fuel subassemblies. In Test section 37GC, the central 24 subchannels were blocked by a stainless steel plate and in Test section 37GE one-half edge part (39 subchannels) of the total flow area was blocked by the same material. The experimental results were compared with data obtained in similar tests using a spacer wire-type pin bundle, designated 37WC. The temperature rises in 37GE and 37WC were nearly identical in value and effect of gas release rate. The marked agreement seems to imply that there is a limit in the content of released gas in the wake region. On the other hand, the temperature rise behind the central blockage in the grid-type bundle, where gas might easily flow out to the core flow region, was far less than in the other geometries.     

Using variance analysis of multitemporal MODIS images for rice field mapping in Bali Province,Indonesia

Existing methods for rice field classification have some limitations due to the large variety of land covers attributed to rice fields. This study used temporal variance analysis of daily Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images to discriminate rice fields from other land uses. The classification result was then compared with the reference data. Regression analysis showed that regency and district comparisons produced coefficients of determination (R ²) of 0.97490 and 0.92298, whereas the root mean square errors (RMSEs) were 1570.70 and 551.36 ha, respectively. The overall accuracy of the method in this study was 87.91%, with commission and omission errors of 35.45% and 17.68%, respectively. Kappa analysis showed strong agreement between the results of the analysis of the MODIS data using the method developed in this study and the reference data, with a kappa coefficient value of 0.8371. The results of this study indicated that the algorithm for variance analysis of multitemporal MODIS images could potentially be applied for rice field mapping.     

Generating 1-DOF limit cycle walking at target walking speed by feed-forward and feedback limit cycle control

We propose the feed-forward and feedback (FaF) control systems for generating the limit cycle walking at a target walking speed by the combined rimless wheel (CRW) model. The proposed FaF control systems can calculate a control input constantly based on the mathematical analysis of the current and target walking states. As a result, first, the limit cycle walking at the target walking speed is generated by numerical simulations when the walker is driven by the constant FaF control system. Second, for controlling the convergence speed, we extend the FaF control to the two-period stepwise control systems. The limit cycle walking at the target walking speed is still generated, and the convergence speed is controlled by the settling time parameter. Finally, the real-time walking state updating is considered in the FaF control systems to handle the disturbances. In this case, we find that for generating a target walking speed, a precise mathematical model is not necessary for generating the target state, but can make the control input stable and efficient.