Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 80, Issue 4
Displaying 1-5 of 5 articles from this issue
  • Yoshihide KOZAI
    2004 Volume 80 Issue 4 Pages 157-165
    Published: 2004
    Released on J-STAGE: August 25, 2004
    In this paper the theory of secular perturbations of asteroids with high inclinations and eccentricities (1962) is reviewed and extended analytically for orbits of Kuiper-belt objects and the problem of stellar three bodies consisting of a binary and a distant third body. The theory thus extended seems to be consistent with numerical results published in various papers on subjects like periodic comets, planets of extra-solar systems, star clusters and binaries of black-holes.

    (Contributed by Yoshihide KOZAI, M. J. A.)
    Download PDF (660K)
    2004 Volume 80 Issue 4 Pages 166-178
    Published: 2004
    Released on J-STAGE: August 25, 2004
    The term alkaliphile is used for microorganisms that grow optimally or very well at pH values above 9, but cannot grow or grow only slowly at the near neutral pH value of 6.5. Alkaliphiles include prokaryotes, eukaryotes, and archaea. Alkaliphiles can be isolated from normal environments such as garden soil, although viable counts of alkaliphiles are higher in samples from alkaline environments. The cell surface plays a key role in keeping the intracellular pH value in the range between 7 and 8.5, allowing alkaliphiles to thrive in alkaline environments. Alkaliphiles have made a great impact in industrial applications. Biological detergents contain alkaline enzymes, such as alkaline cellulases and/or alkaline proteases that have been produced from alkaliphiles. Another important application is the industrial production of cyclodextrin with alkaline cyclomaltodextrin glucanotransferase. This enzyme reduced the production cost and paved the way for cyclodextrin use in large quantities in foodstuffs, chemicals and pharmaceuticals. It has also been reported that alkali-treated wood pulp could be biologically bleached by xylanases produced by alkaliphiles.

    (Communicated by Masanao MATSUI, M.J.A.)
    Download PDF (781K)
Original Papers
  • Kanetada NAGAMINE
    2004 Volume 80 Issue 4 Pages 179-182
    Published: 2004
    Released on J-STAGE: August 25, 2004
    By using a well-defined mono-energetic, pencil-like, high-energy and intense muon beam, one can realize, via simultaneous measurements of energy-loss and multiple-scattering, a quick and element-selective radiography to detect e.g. a few kg of U which is shielded in a thick Fe container or hidden within 2-3 m of low-Z material. A source of such an ideal beam of muons can be realized in transportable form via truck trailers, by combining a compact 400 MeV electron accelerator for photo π/μ production, a superconducting solenoid for full-solid-angle π/μ capture and transport, a stopping in hot tungsten metal for cooling of energetic μ+ to sub-eV μ+, and finally a compact linear accelerator for rapid acceleration to 600 MeV. Principle and some details are described.

    (Communicated by Kazuhiko NISHIJIMA, M.J.A.)
    Download PDF (810K)
  • 5. Fourier filtration of images
    Sanae A. ISHIJIMA, Lester CLOWNEY, Masashi SUZUKI
    2004 Volume 80 Issue 4 Pages 183-188
    Published: 2004
    Released on J-STAGE: August 25, 2004
    Microcrystals of the feast/famine regulatory protein (FFRP) pot0434017 (FL11) were prepared by sonicating larger crystals. Using the microcrystals a cryo-electron micrograph was obtained, which showed a hexagonal packing of cylinder-like assemblies of FL11. This micrograph was processed by selecting, in the Fourier space, spots reflecting the crystal lattice, thereby removing the noise. The microcrystal was not totally free from distortion, and cylinders in local clusters adopted slightly different orientations. Thus, 25 hexagonal units closest to the ideal, each containing a cylinder at the center surrounded by six others, were manually selected. The averaged image was further processed to yield a perfect six-fold symmetry. These processed images, and some of the original images too, show bridges connecting cylinders, each corresponding to two pairs of N-domains, protruding from the two cylinders and contacting between them in the X-ray structure.

    (Communicated by Masanori OTSUKA, M.J.A.)
    Download PDF (1103K)
  • Hikoya HAYATSU, Kazuo NEGISHI, Masahiko SHIRAISHI
    2004 Volume 80 Issue 4 Pages 189-194
    Published: 2004
    Released on J-STAGE: August 25, 2004
    Understanding the biological consequences of DNA methylation is a current focus of intensive studies. A standard method for analyzing the methylation at position 5 of cytosines in genomic DNA involves chemical modification of the DNA with bisulfite, followed by PCR amplification and sequencing. Bisulfite deaminates cytosine, but it deaminates 5-methylcytosine only very slowly, thereby allowing determination of the methylated sites. The deamination is usually performed using sodium bisulfite solutions of 3-5 M concentration with an incubation period of 12-16 hr at 50 °C. We demonstrate here that this deamination can be speeded up significantly. We prepared a solution of 10 M bisulfite concentration of pH 5.4 and used it to treat DNA at temperatures up to 90 °C. In an experiment, in which denatured DNA was treated with 9 M bisulfite for 10 min at 90 °C, deamination of cytosines occurred to an extent of 99.6%, while 5-methylcytosine residues in the DNA were deaminated at less than 10%. Using a plasmid DNA fragment, we observed that the DNA can serve as a template for PCR amplification after the bisulfite treatment. This new procedure is expected to offer a significantly improved genomic sequencing method, leading to the promotion of research on understanding the biological and medical significance of DNA methylation.

    (Communicated by Takashi SUGIMURA, M.J.A.)
    Download PDF (501K)