Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 83, Issue 7
Displaying 1-4 of 4 articles from this issue
  • Toshisuke MARUYAMA
    2007 Volume 83 Issue 7 Pages 181-191
    Published: July 30, 2007
    Released on J-STAGE: November 02, 2007
    To estimate the amount of evapotranspiration in a river basin, the “short period water balance method” was formulated. Then, by introducing the “complementary relationship method,” the amount of evapotranspiration was estimated seasonally, and with reasonable accuracy, for both small and large areas. Moreover, to accurately estimate river discharge in the low water season, the “weighted statistical unit hydrograph method” was proposed and a procedure for the calculation of the unit hydrograph was developed. Also, a new model, based on the “equivalent roughness method,” was successfully developed for the estimation of flood runoff from newly reclaimed farmlands. Based on the results of this research, a “composite reservoir model” was formulated to analyze the repeated use of irrigation water in large spatial areas. The application of this model to a number of watershed areas provided useful information with regard to the realities of water demand-supply systems in watersheds predominately dedicated to paddy fields, in Japan.

    (Communicated by Toshio SAWADA, M.J.A.)
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Original Papers
  • —Electrostatic attraction between similarly charged species—
    Norio ISE
    2007 Volume 83 Issue 7 Pages 192-198
    Published: July 30, 2007
    Released on J-STAGE: November 02, 2007
    In the Derjaguin-Landau-Verwey-Overbeek (DLVO) framework of the past 60 years, colloidal interaction between similarly charged particles has been claimed to be simply repulsive, and an attraction such as the van der Waals interaction is attached to the Coulombic repulsion. Statistical-thermodynamic considerations show that the electrostatic Helmholtz free energy ΔFel is generally not equal to the electrostatic Gibbs free energy ΔGel for simple ionic solutions, and the difference ΔGel–ΔFel (corresponding to the electrostatic osmotic pressure pel) becomes larger with increasing charge number. Thus, it is expected that ΔGel–ΔFel be large for highly charged macroions. In the DLVO framework, however, ΔGelFel was postulated. Sogami showed that a mean field approach reproduced repulsion at the level of ΔFel but resulted in (repulsion and) attraction at the level of ΔGel. Overbeek’s critique of Sogami theory is shown to be in error. If this criticism were correct, then not only the Sogami theory but also the Debye-Hückel theory would be wrong. The attraction is thus confirmed to exist not only for multi-valent but also mono-valent counterions.

    (Communicated by Hiroo INOKUCHI, M.J.A.)
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  • Toshitaka GAMO, Kei OKAMURA, Kyohiko MITSUZAWA, Kenichi ASAKAWA
    2007 Volume 83 Issue 7 Pages 199-204
    Published: July 30, 2007
    Released on J-STAGE: November 02, 2007
    We successfully deployed an in situ automatic chemical analyzer sensitive to manganese (Mn) in seawater for a period of 81 days for the first time on the deep seafloor of Sagami Bay along a convergent plate boundary south of Japan. The in situ Mn analyzer (GAMOS-IV) was connected to a submarine cable as a means to supply power and to relay real time data. During the observation period from April 5 till June 25, 2006, the amount of measured Mn was seen to increase abruptly up to 10 times that of the background level only on April 21, probably triggered by a M5.8 earthquake which occurred ∼7 km south-southwest of the observation site. This study demonstrates the suitability of submarine cables for the long-term geochemical monitoring of deep sea environments.

    (Communicated by Taroh MATSUNO, M.J.A.)
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  • Yutaka AOKI, Atsuhiko TOYAMA, Takashi SHIMADA, Tetsuyoshi SUGITA, Chik ...
    2007 Volume 83 Issue 7 Pages 205-214
    Published: July 30, 2007
    Released on J-STAGE: November 02, 2007
    Significant advances have been made in the past decade in the field of mass spectrometry imaging (MS imaging). It is a relatively unestablished technique aimed at direct, high-sensitive and spatially exclusive detection of biological molecules from the surface of tissue sections, so that semi-quantitative distribution map of the analyte can be reconstituted from the mass spectra obtained. There is tremendous potential in its application especially in clinical field, such as biomarker discovery or pharmacokinetic study. However, vast majority of the work has been performed on frozen tissue sections, while it remains generally unpractical to produce frozen sections with clinically resected tumor samples. Here we report our novel sample preparation technique that enabled MS imaging from formalin-fixed paraffin embedded (FFPE) tissue section, including retrospective archive as old as 11 years. FFPE sections were first dewaxed with pre-warmed xylene, and exposed tissue surface was enzymatically digested in nanoliter scale droplets to retain analyte localization. As a result, we succeeded in obtaining MS images of peptide peaks derived from several proteins, identified by MS/MS analysis, using ovarian cancer FFPE sections. The qualities of mass spectra obtained by this method were not significantly different from those obtained from frozen sections. By this, we opened the door to retrospective study of past clinical cases in aim to discover molecular biomarker.

    (Communicated by Koichi TANAKA, M.J.A.)
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