A High-Methionine Diet for One-Week Induces a High Accumulation of Methionine in the Cerebrospinal Fluid and Confers Bipolar Disorder-like Behavior in Mice

Methionine (Met) is considered the most toxic amino acid in mammals. Here, we investigated biochemical and behavioral impacts of ad libitum one-week feeding of high-Met diets on mice. Adult male mice were fed the standard rodent diet that contained 0.44% Met (1×) or a diet containing 16 graded Met doses (1.2×–13×). High-Met diets for one-week induced a dose-dependent decrease in body weight and an increase in serum Met levels with a 2.55 mM peak (versus basal 53 µM) on the 12×Met diet. Total homocysteine (Hcy) levels were also upregulated while concentrations of other amino acids were almost maintained in serum. Similarly, levels of Met and Hcy (but not the other amino acids) were highly elevated in the cerebrospinal fluids of mice on the 10×Met diet; the Met levels were much higher than Hcy and the others. In a series of behavioral tests, mice on the 10×Met diet displayed increased anxiety and decreased traveled distances in an open-field test, increased activity to escape from water soaking and tail hanging, and normal learning/memory activity in a Y-maze test, which were reflections of negative/positive symptoms and normal cognitive function, respectively. These results indicate that high-Met ad libitum feeding even for a week can induce bipolar disorder-like disease models in mice.     

Ultrasonic attenuation monitoring of fatigue damage in low carbon steels with electromagnetic acoustic resonance (EMAR)

We studied microstructure evolution during tension-compression fatigue in low carbon steels, containing C: 0.15 mass%. In situ monitoring of axial-shear-wave attenuation and velocity was achieved with electromagnetic acoustic resonance (EMAR), which is a combination of the resonant spectroscopy technique and a noncontacting electromagnetic acoustic transducer (EMAT). Transduction occurs with the magnetostriction effect and is the key to establish a continuous monitoring of microstructural changes in the surface region of the metals with high sensitivity. We found for the first time that the attenuation is highly sensitive to the accumulated fatigue damage, showing a minimum around 20% of the whole life. This phenomenon is interpreted in terms of drastic change of dislocation mobility and rearrangement, which is supported by TEM observation for dislocation structure. This technique has the potential to assess the damage advance and to predict the fatigue life of metals.     

Development of voltage sag compensator and UPS using a flywheel induction motor and an engine generator

Flywheel energy storage systems are attracting attention as uninterruptible power supplies (UPS) from the viewpoint of environmental friendliness and high durability performance. Using a low‐speed, heavy flywheel and a low‐cost squirrel‐cage induction motor/generator, two applications are proposed: (1) an 11‐kW voltage sag compensator using a capacitor self‐excited induction generator without semiconductor converters and (2) a UPS composed of the flywheel system and an engine generator. Based on experimental results, an ideal voltage sag compensator and UPS are realized by the low‐technology flywheel system. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 74– 81, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20784     

The High-Resolution X-Ray Microcalorimeter Spectrometer, SXS, on Astro-H

The science and an overview of the Soft X-ray Spectrometer onboard the STRO-H mission are presented. The SXS consists of X-ray focusing mirrors and a microcalorimeter array and is developed by international collaboration lead by JAXA and NASA with European participation. The detector is a 6×6 format microcalorimeter array operated at a cryogenic temperature of 50 mK and covers a 3′×3′ field of view of the X-ray telescope of 5.6 m focal length. We expect an energy resolution better than 7 eV (FWHM, requirement) with a goal of 4 eV. The effective area of the instrument will be 225 cm² at 7 keV; by a factor of about two larger than that of the X-ray microcalorimeter on board Suzaku. One of the main scientific objectives of the SXS is to investigate turbulent and/or macroscopic motions of hot gas in clusters of galaxies.     

Comparative structural biology of the genome: nano-scale imaging of single nucleus from different kingdoms reveals the common physicochemical property of chromatin with a 40 nm structural unit

Genome function is closely linked to the higher-order chromatin structures. To reveal a structural basis for the interphase chromatin organization, the 'on-substrate' lysis procedure was applied to nuclei isolated from human HeLa cells, chicken erythrocyte cells and yeast Schizosaccharomyces pombe, which possessed different intrinsic properties of the genomes such as histone composition and inter-nucleosomal distance. The isolated nuclei on a coverslip were successively treated with a detergent and a high-salt solution to extract the nuclear membrane and the nucleoplasm, and therefore, atomic force microscopy (AFM) visualized the structural changes in response to the lysis procedure. After the nucleoplasm was extracted, AFM clarified that chromatin fibers, approximately 40 nm in width, were partially released out of the nuclei and that the other chromatin still remaining in the nuclei was composed of granular structures with diameter of 80-100 nm. Thus, these results suggest that the approximately 40 nm fiber would be a stable structural unit and fold the 80-100 nm granules into a one-step higher unit. A common mechanism could be implied regardless of the intrinsic properties of the eukaryotic genomes.     

Sway measurement of overhead power lines by ITV‐based camera

We have developed a new method that can measure movement of overhead power lines in the wind. This method uses images from an ITV camera system. The sway of the power line is videotaped and analyzed. Its measured frequency response to wind is compared to a theoretical model. It is found that the new method yields results that are in good agreement with those obtained from the theoretical model for frequency response less than 0.5 Hz. With the result of frequency response, we can calculate the sway mode of the power line in the wind. Our method also offers displacement of the sway of the cable. We compared our method to the laser measurement, and found a difference of about 10 cm at 255 m from the camera. © 2001 Scripta Technica, Electr Eng Jpn, 137(4): 18–24, 2001     

Bacterial phosphate metabolism and its application to phosphorus recovery and industrial bioprocesses

Enhanced biological phosphorus removal (EBPR) has become a well-established process and is currently applied in many full-scale wastewater treatment processes. Phosphorus recovered from EBPR waste sludge can be used as a raw material for the fertilizer industry, if a sound recycling strategy is developed and applied. In this review, we summarize our current knowledge on phosphate metabolism in bacteria, focusing on molecular mechanisms of bacterial polyphosphate (polyP) accumulation. A simple method for releasing polyP from EBPR waste sludge and recovering phosphorus in a reusable form for the fertilizer industry is presented. We also describe a recent development of bioprocesses for the expanded use of polyP in the production of value-added chemicals.     

Analog integrated circuits for the Lotka-Volterra competitiveneural networks

A subthreshold MOS integrated circuit (IC) is designed and fabricated for implementing a competitive neural network of the Lotka-Volterra (LV) type which is derived from conventional membrane dynamics of neurons and is used for the selection of external inputs. The steady-state solutions to the LV equation can be classified into three types, each of which represents qualitatively different selection behavior. Among the solutions, the winners-share-all (WSA) solution in which a certain number of neurons remain activated in steady states is particularly useful owing to robustness in the selection of inputs from a noisy environment. The measured results of the fabricated LV ICs agree well with the theoretical prediction as long as the influence of device mismatches is small. Furthermore, results of extensive circuit simulations prove that the large-scale LV circuit producing the WSA solution does exhibit a reliable selection compared with winner-take-all circuits, in the possible presence of device mismatches.     

Time-resolved measurements of photovoltage generation by bacteriorhodopsin and halorhodopsin adsorbed on a thin polymer film

We constructed a time-resolved photovoltage measurement system and examined the photovoltage kinetics of wild-type bacteriorhodopsin, its D96N mutant, and halorhodopsins from Halobacterium salinarum and Natronobacterium pharaonis. Upon illumination with a laser flash, wild-type bacteriorhodopsin showed photovoltage generation with fast (10-100 micros range) and slow (ms range) components while D96N lacked the latter, as reported previously [Holz, M., Drachev, L.A., Mogi, T., Otto, H., Kaulen, A.D., Heyn, M.P., Skulachev, V.P., and Khorana, H.G. (1989) Proc. Natl. Acad. Sci. USA 86, 2167-2171]. In contrast, photovoltage generation in halorhodopsins from H. salinarum and N. pharaonis was significant only in the ms time range. On the basis of the photovoltage kinetics and photocycle, we conclude that major charge (chloride) movements within halorhodopsin occur during the formation and decay of the N intermediate in the ms range. These observations are discussed in terms of the "Energization-Relaxation Channel Model" [Muneyuki, E., Ikematsu, M., and Yoshida, M. (1996) J. Phys. Chem. 100, 19687-19691].