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11.
Yukiyoshi Teramoto Etsuro Shimokawa Tsugio Ezaki Kun-Woo Chun Suk-Woo Kim Youn-Tae Lee 《林业研究》2017,28(2):309-317
This study was conducted in order to examine the influence of long-term volcanic activity on vegetative succession and growth on the slope of Sakurajima in southern Kyushu, Japan. We investigated the vegetation,depth of the volcanic ash layer, and dry density and p H of the surface soil at six places on the north-northwestern slope, 2.3–3.4 km from the Minami-dake crater, where a layer of pumice stone was deposited by the Taisho eruption in 1914. The height and diameter at breast height(DBH) of the trees increased with increasing distance from the Minami-dake crater, as did the number of individuals and species, and basal area. The Shannon–Wiener diversity index(H') demonstrates that vegetative succession is significantly affected by distance from the Minami-dake crater, as areas farther from the crater exhibited later seral stages. Comparison of the diversity index and species number of the crater region with that of the climax forest in Kagoshima indicates that vegetative growth alone cannot advance succession in the study area, as the local vegetative community is heavily influenced by the harsh environmental conditions associated with continual exposure to long-term volcanic activity. Seral stage, ash layer depth,dry density, and p H of the soil surface layer are governed by distance from the Minami-dake crater. The results of this study indicate that conditions for vegetative growth and succession improve with increasing distance from the source of constant volcanic activity. Thus, soil development is promoted by the acidification of the soil, which decreases the dry density and p H of the soil surface layer.The introduction of plant species resistant to volcanic ash and gas is recommended to promote soil development and improve the infiltration capacity of the soil. 相似文献
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Frederick P. C. Blamey Naoko K. Nishizawa Etsuro Yoshimura 《Soil Science and Plant Nutrition》2005,51(5):705-708
Decreased root elongation and rupture of outer cells, major effects of soluble aluminum (Al), may be studied using digital microscopy with little interference by the experimental technique. Single roots of 3-d-old mungbean ( Vigna radiata L.) or soybean ( Glycine max (L.) Merr.) seedlings were marked with activated charcoal particles and grown for ca. 2 h in 500 mL 1 mM CaCl2 solution at pH 6, followed by the imposition of an Al treatment. A digital image at 25-time magnification was recorded every 5 min for up to 7 h. Examination of the digital images showed that Al exerted its rhizotoxic effects rapidly (ca. 20–50 min) by reducing cell expansion in the elongation zone. Rupture of epidermal and outer cortical cells occurred later (after≥4 h) and closer to the root tip. Digital microscopy has a number of inherent benefits and problems, but is overall a valuable technique that may find wide use in studies on root growth. 相似文献
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Kin-Ichi Tsunoda Tomonari Umemura Kazumasa Ohshima Sho-Ichi Aizawa Etsuro Yoshimura Ken-Ichi Satake 《Water, air, and soil pollution》2001,130(1-4):1589-1594
A cation-exchange high-performance liquid chromatography with high resolution inductively coupled plasma mass spectrometric detection (CE-HPLC/ICP-MS) was developed for the determination and the speciation of aluminum in environmental samples. Three types of aluminum species (AlLx <+2, AlLx 2+, Al3+) were separated from one another, and were determined with the present system. The comparison of the present system with an established CE-HPLC with fluorimetric detection using 5-sulfo-8-quinolinol (CE-HPLC/FL) was described. The present system showed better sensitivity for aluminum than CE-HPLC/FL. Moreover, the analytical results for soil extract and lake water samples obtained with both methods were in good agreement with each other. 相似文献
14.
An efficient procedure for the cryopreservation of fish blastomeres followed by restoration through germ-line chimera formation was established. Blastomeres of the loach (Misgurnus anguillicaudatus) were cryopreserved in 250-μL straws in Eagle's minimum essential medium with various concentrations of dimethyl-sulfoxide (0, 5, 10, 15, and 20%), and the best concentration was combined with glycerol (1, 2, and 4%) and external cryoprotectants (1 or 2% sucrose; 2, 5, or 10% fetal bovine serum; 1 or 2% BSA). Postthaw viability of the blastomeres was used to optimize cryopreservation conditions. Donor blastomeres were injected with zebrafish green fluorescence protein-nos1 3' untranslated region mRNA and biotin dextran before cryopreservation in the optimal freeze medium. Host embryos were injected with zebrafish DsRed-nos1 3' untranslated region mRNA and reared to the blastula stage. Donor blastomeres were thawed at 25 °C for 10 s and transplanted to the host embryos either immediately or after incubation for 16 h at 20 °C. Donor and host primordial germ cell migration was visualized with fluorescent imaging during the early stages of embryogenesis, and also by histology in 4-d-old embryos. Transplantation of blastomeres immediately after thawing gave decreased hatching rates (approximately 3%) and generated a smaller percentage of germ-line chimeras (approximately 1.1%). In contrast, incubation of a cryopreserved sample for 16 h followed by transplantation of the green fluorescence protein-positive blastomeres improved the hatching rate to 90%, and successfully produced presumable germ-line chimeras at a rate of 16.5%. The improved survival rates and germ-line chimerism may be an effective method for gene banking and subsequent reconstitution of endangered fish genotypes. 相似文献
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Etsuro Yoshimura Seiji Nagasaka Yoshiyuki Sato Kenichi Satake Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(3):721-724
A strain of an acidophilic, thermophilic alga, Cyanidium caldarium, was cultured in a medium containing various metal ions (A1, Cd, Cr, Cu, Mn, Ni, Zn). Among these metals, the alga tolerates especially high levels of AI: it can grow in a medium containing 200 mM AI, although the growth rate was reduced to 58%. The cellular Al concentration was kept at a considerably lower level as compared to the medium Al concentration. This may account for the Al tolerance of the alga. Treatment of the algal cells with carbonylcyanide m-chlorophenylhydrazone in the presence of Al increased the cellular Al concentration. It was suggested that energy-coupled Al exclusion mechanisms can operate in the alga. 相似文献
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Polygraphus proximus Blandford (Coleoptera: Curculionidae: Scolytinae) has caused mass mortality of fir (Abies spp. (Pinaceae)) forests across large areas of Russia in the past decade. More recently, mass mortality of A. veitchii Lindl. due to P. proximus infestation has been reported in Japan. This bark beetle species traditionally has been considered to be polygynous because their galleries have multiple gallery arms, and because harem-polygyny is common in the tribe Polygraphini. Although the mating system(s) potentially could have a marked effect on their reproductive success and population dynamics, the reproductive behavior of the tree-killing bark beetle P. proximus has not been investigated in detail in a natural setting in Japan. We, therefore, investigated the number of males and females in a gallery and the number of gallery arms in Abies species in Japan. None of the galleries examined contained more than one male, and 57.2% of the galleries had multiple gallery arms, even though only 2.8% of the galleries contained two females. The findings showed that the typical mating system employed by P. proximus is monogyny and that this species constructs multiple gallery arms in each gallery. In addition, 70.4% of galleries in which the sex of adult beetles could be determined contained no males, and 26.6% contained no females, suggesting that P. proximus males and females re-emerge. 相似文献
19.
Hiroki Takakuwa Tetsu Yamashiro Mai Q. Le Lien S. Phuong Hiroichi Ozaki Ryota Tsunekuni Tatsufumi Usui Hiroshi Ito Tsuyoshi Yamaguchi Toshihiro Ito Toshiyuki Murase Etsuro Ono Koichi Otsuki 《Comparative immunology, microbiology and infectious diseases》2013
Due to concerns that wild birds could possibly spread H5N1 viruses, surveillance was conducted to monitor the types of avian influenza viruses circulating among the wild birds migrating to or inhabiting in northern Vietnam from 2006 to 2009. An H5N2 virus isolated from a Eurasian woodcock had a close phylogenetic relationship to H5 viruses recently isolated in South Korea and Japan, suggesting that H5N2 has been shared between Vietnam, South Korea, and Japan. An H9N2 virus isolated from a Chinese Hwamei was closely related to two H9N2 viruses that were isolated from humans in Hong Kong in 2009, suggesting that an H9N2 strain relevant to the human isolates had been transmitted to and maintained among the wild bird population in Vietnam and South China. The results support the idea that wild bird species play a significant role in the spread and maintenance of avian influenza and that this also occurs in Vietnam. 相似文献
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Abstract Properties and classification of four selected volcanic ash soils from Abashiri, Hokkaido were studied and the transition of Andisols to Mollisols was discussed. Two of the four pedons (Brown Andosol and Cumulic Andosol)1 showed morphological, clay mineralogical, physical, and chemical properties common to most Andisols in Japan. However, the properties of the other two pedons (Acid Brown Forest soil and Brown Forest soil)1 were considerably different from those of common Andisols in Japan. It was found that the changes in the andic soil properties or transition of Andisols to Mollisols was closely related to the progression of clay weathering, mainly the transformation of noncrystalline clay materials to halloysite. One of the four pedons (Brown Forest soil)1had the clay fraction dominated by halloysite from the uppermost horizon down to the bottom of the profile and satisfied both andic and mollic requirements. Thus we concluded that the pedon is a transitional soil between Andisols and Mollisols and that the transition is closely related to the duration of surface weathering under relatively weak leaching conditions. The four pedons were classified according to the Andisol Proposal (Leamy et al. 1988, New Zealand Soil Bureau) as follows: Pedon 1: Medial, amorphic (allophane/imogolite), frigid Typic Hapludand (Brown Andosol).1 Pedon 2: Medial, amorphic (allophane/imogolite), frigid Typic Melanudand (Cumulic Andosol).1 Pedon 3: Medial, amorphic (allophane/ imogolite), over kandic, frigid Typic Melanudand (Acid Brown Forest soil).1 Pedon 4: Medial, kandic, frigid Typic Hapludand (Brown Forest soil).1 相似文献