Viva Origino
Online ISSN : 1346-6933
Print ISSN : 0910-4003
36 巻, 3 号
選択された号の論文の6件中1~6を表示しています
  • Tsutomu Nishimura, Kaneo Mohri, Masanori Fukushima
    2008 年 36 巻 3 号 p. 44-50
    発行日: 2008年
    公開日: 2022/01/18
    ジャーナル フリー

      A number of ecological and evolutionary patterns or ‘rules’ dealing with body size have been proposed over the years, the most prominent being Bergmann’s rule, Cope’s rule, and Rensch’s rule. The mechanisms underlying these patterns remain enigmatic. We focused on the relationship between magnetic field (MF) exposure and animal body size because Bergmann’s rule holds that organisms tend to be larger at higher latitudes, where the geomagnetic field is more than twofold stronger than at lower latitudes. We researched the relationship between electromagnetic field (EMF) exposure and change in animal body weight using data in the literature. We conducted a meta-regression analysis to examine the impact of EMF exposure on animal weight as compared with the weight of unexposed controls. Meta-regression showed that EMF exposure had a statistically significant positive association with relative weight in males but not in females. The increase in body weight would explain Rensch’s rule. The increase in the relative weights of males would explain Bergmann’s and Cope’s rules. Over successive generations, animals would gradually gain a considerable amount of body size if environmental MF and/or EMF become stronger over the course of time, which explains Cope’s rule.

  • Masatoshi OHISHI
    2008 年 36 巻 3 号 p. 51-54
    発行日: 2008年
    公開日: 2022/01/18
    ジャーナル フリー

      It is known that more than 140 interstellar and circumstellar molecules have so far been detected, mainly by means of the radio astronomy observations. Many organic molecules are also detected, including alcohols, ketons, ethers, aldehydes, and others, that are distributed from dark clouds and hot cores in the giant molecular clouds. It is believed that most of the organic molecules in space are synthesized through the grain surface reactions, and are evaporated from the grain surface when they are heated up by the UV radiation from nearby stars. On the other hand the recent claim on the detection of glycine have raised an important issue how difficult it is to confirm secure detection of weak spectra from less abundant organic molecules in the interstellar molecular cloud.

      Recent topics regarding observations of organic molecules in the interstellar molecular clouds, including independent observations of glycine by the 45m radio telescope and a detection of amino acetonitrile (NH2CH2CN) that is a precursor to glycine.

  • Eiichi Tajika
    2008 年 36 巻 3 号 p. 55-60
    発行日: 2008年
    公開日: 2022/01/18
    ジャーナル フリー

      The only geological evidence for the early Earth is zircon which suggests existence of continental crust and oceans at 4.404 billion years ago. Based on the record of the lunar impact craters, it has been considered that heavy bombardment of small solar system bodies to the Earth-Moon system occurred during the first several hundred million years. There is however another possibility that an intense, but short-term impact event (called the cataclysm) might have occurred at around 3.9 billion years ago, which could have been caused by rapid migration of the giant planets. The atmospheric composition during the early Earth was reducing, irrespective of source of volatiles. This may have been favorable for the prebiotic synthesis of organic materials and so the origin of life. The early Earth might have been globally glaciated because the heavy bombardment produced a large amount of impact ejecta which consumed the atmospheric CO2 effectively through chemical weathering followed by carbonate precipitation. However, the effects of mantle overturn and large-scale resurfacing on the early Earth’s environment remains unknown.

  • 泉 雄大
    2008 年 36 巻 3 号 p. 61-65
    発行日: 2008年
    公開日: 2022/01/18
    ジャーナル フリー

    Amino acids have been detected from some meteorites. This fact suggests that these amino acids (or its precursors) are produced in space and the possible energy sources should be vacuum ultraviolet (VUV) light, X-ray, high energy particles and so on. To understand the interactions between biomolecules and those energy sources quantitatively, absorption cross section is important information. However, the absorption cross section of biomolecules within the range from VUV to soft X-ray region was hardly reported. Recently our group succeeded to determine the absorption cross section of some amino acids (glycine, alanine, phenylalanine and methionine) in ultraviolet to soft X-ray region (5 nm ≤ wavelength ≤ 350 nm; 3.5 eV ≤ photon energy ≤ 250 eV). Herein, I am going to briefly review the experimental and analytical techniques for the measurements of the absorption cross section, which were recently established in our group.

  • 國田 美穂子
    2008 年 36 巻 3 号 p. 66-68
    発行日: 2008年
    公開日: 2022/01/18
    ジャーナル フリー

      Thermal heterocomplex molecules formed by heating a mixture of amino acids could have been one of the reaction fields for different chemical reactions on the primitive earth. The thermal heterocomplex molecules have a characteristic of thermal hysteresis. Microspherical particles formed from the thermal heterocomplex molecules can be transformed into microcapsules in aqueous solutions with increasing pH. In addition, nucleoside and phosphoric acid can be adsorbed on the surface of the microspherical particles. According to these facts, it is plausible that thermal heterocomplex molecules and their microspherical particles could have important roles for the organization or functionalization of prebiotic molecules.

  • 北台 紀夫
    2008 年 36 巻 3 号 p. 69-71
    発行日: 2008年
    公開日: 2022/01/18
    ジャーナル フリー

      Mineral surfaces have been suggested to play an essential role in prebiotic peptide bond formation. However, mechanisms of amino acids polymerization on mineral surfaces are still poorly understood.

      In the present paper, I review the several factors which may promote the amino acids reactivity on mineral surfaces. This review also addresses the fundamentals of attenuated total reflectance infrared (ATR-IR) spectroscopy; one of the effective techniques to investigate the amino acids adsorption behavior on mineral surfaces.

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