Molecular ecological study of <Emphasis Type="Italic">Siganus spinus</Emphasis> and <Emphasis Type="Italic">S. guttatus</Emphasis> from Okinawan waters based on mitochondrial DNA control region sequences     

Kensuke Iwamoto  Akihiro Takemura  Tetsuo Yoshino  Hideyuki Imai 《Journal of Oceanography》2009,65(1):103-112

The mitochondrial DNA (mtDNA) control region was sequenced to examine the genetic variability and gene flow of juvenile Siganus spinus and S. guttatus. In total, 461 nucleotide sequences were obtained from 69 specimens of juvenile S. spinus from Okinawa Island and Ishigaki Island, in which 17 variable sites and 22 haplotypes were identified. Haplotype diversity (h) was high (0.9244 in Okinawa and 0.8984 in Ishigaki), whereas nucleotide diversity (π) was low (0.0063 in Okinawa and 0.0059 in Ishigaki). The two populations were not genetically distinct. Siganus guttatus, which do not form large schools at recruitment, in contrast S. spinus, were also analyzed by studying 152 individuals collected off Okinawa Island, Miyako Island, and Ishigaki Island. Of 476 nucleotide sequences, 50 were variable, and 42 haplotypes were identified. Genetic variability values were high (h = 0.8766 and π = 0.0151 in Okinawa; h = 0.9640 and π = 0.0192 in Miyako; h = 0.9161 and π = 0.0199 in Ishigaki). The Okinawa population was genetically isolated from the Miyako and Ishigaki populations. As a result, genetic diversity was high for each of these siganid populations despite their being target species for fisheries; however, the degree of inter-population gene flow was higher for S. spinus than S. guttatus, suggesting that these species exhibit different dispersal strategies.  相似文献   

Editorial board member retires: Professor Dr. Akira Watanabe     

Masatoshi M. Yoshino 《Geoforum》1973,4(1):4

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Book reviews     

Wolf Tietze  Gerhard Kortum  W. R. Mead  T. K. Poiker  C. Paddick  George Kish  A. Njøs  H. Mensching  V. Haarmann  Uzo M. Igbozurike  M. M. Yoshino  Mushtaqur Rahman  Lage Wahlström  J. Connell  Kazimierz Dziewonski  Wayland R. Swain  J. Humlum  G. W. Lüttig  Haruko Kishimoto  Mai Britt E. Mørk 《GeoJournal》1982,6(3):270-280

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Growth of ringwoodite reaction rims from MgSiO3 perovskite and periclase at 22.5 GPa and 1,800 °C     

Akira Shimojuku  Asmaa Boujibar  Daisuke Yamazaki  Takashi Yoshino  Naotaka Tomioka  Junshan Xu 《Physics and Chemistry of Minerals》2014,41(7):555-567

The growth rate of ringwoodite reaction rims between MgSiO₃ perovskite and periclase was investigated at 22.5 GPa and 1,800 °C for 1–24 h using the Kawai-type high-pressure apparatus. The reaction was likely to proceed by a diffusion-controlled mechanism in which the dominant diffusion mechanism was grain-boundary diffusion. The reaction constant (the width of the ringwoodite reaction rim squared divided by time) determined from these experiments was between 1.3 × 10^?15 and 5.6 × 10^?15 m²/s. A Pt inert marker experiment indicated that the MgO component migrated faster than the SiO₂ component in ringwoodite. Thus, either Mg or O having the slower diffusion rate controlled the reaction. Because previous diffusion studies have shown that diffusion rates of O are slower than those of Mg, O would be a rate-controlling element for ringwoodite formation from MgSiO₃ perovskite and periclase. The growth rate appeared to be too fast to explain the observed topographic rise (~10 km) inside mantle plumes at the 660-km discontinuity.  相似文献   

Book reviews     

Richard M. Hammer  Masatoshi M. Yoshino  K. Cehak 《GeoJournal》1979,3(2):222-224

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IGU working group on tropical climatology and human settlements     

Yoshino  M. M. 《GeoJournal》1983,7(1):70-71

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The International Geographical Union reports     

Professeur Pierre Pagney  Professeur Simon Nieuwolt  Professor M. M. Yoshino 《GeoJournal》1983,7(6):568-569

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IGU Working Group on “tropical climatology and human settlements”     

Masatoshi M. Yoshino 《GeoJournal》1981,5(2):179-181

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Concentrations of metallic elements in long-range-transported aerosols measured simultaneously at three coastal sites in China and Japan     

Kojiro?ShimadaEmail author  Xiaoyang?Yang  Yushi?Araki  Ayako?Yoshino  Akinori?Takami  Xuan?Chen  Fan?Meng  Shiro?Hatakeyama 《Journal of Atmospheric Chemistry》2018,75(2):123-139

To determine the effects of long-range transport of aerosols from an upwind area in East Asia to a downwind area in Japan, we chemically analyzed aerosols collected simultaneously on Tuoji Island (Shandong Province, China), Fukue Island (Nagasaki Prefecture, Japan), and Cape Hedo (Okinawa Prefecture, Japan). We focused on changes in the metallic composition of PM_2.5 aerosols during long-range transport. The average mass concentrations of PM_2.5 at the three sites decreased in the order Tuoji Island > Fukue Island ≈ Cape Hedo (48.3 ± 4.5, 13.9 ± 1.5, and 13.2 ± 0.9 μg/m³, respectively). The fraction of coarse particles in total suspended particles estimated by (1–PM_2.5/TSP) was highest on Cape Hedo, indicating that the contribution of sea salts was increased by long-range transport of the aerosols over the ocean. Enrichment factor analysis revealed that at all three sites, Al, K, Ca, Mn, Fe, Co, Sr, and Ba originated from soil; whereas Cr, Ni, Cu, Zn, As, Mo, Ag, Cd, Sn, Sb, Tl, and P appeared to be of anthropogenic origin. Na was the most abundant element on Cape Hedo, indicating the addition of sea salts during aerosol transport. The V concentration was highest at Fukue Island, which was ascribed to V emission from ships. Sixty-one percent of the V on Fukue Island and 62% of the V on Cape Hedo were determined to have originated from ships, implicating of data obtained on dates during which backward trajectory analysis indicated that the same air mass passed over Tuoji Island, Fukue Island, and Cape Hedo in that order.  相似文献   

1600 K和20 GP温压条件下的顽火辉石电导率   总被引：2，自引：1，他引：1       下载免费PDF全文

张宝华  吴小平  许俊闪  Tomoo Katsura  Takashi Yoshino 《地球物理学报》2010,53(3):760-764

在温度750～1600 K和压力10～20 GPa条件下,借助于Kawai-5000多面顶砧高温高压设备,就位测量了(Mg_0.9Fe_0.1) SiO₃ 顽火辉石的电导率.实验结果显示,顽火辉石的电导率在高温区以小极化子机制为主,在低温区以质子导电为主,因为实验后的样品中有一定的水含量.另外,X射线衍射实验表明压力（20 GPa）诱发了顽火辉石向林伍德石的相变,这是我们首次在顽火辉石的电导率实验中观测到林伍德石含水相变,而且含水林伍德石的电导率与已有的实验结果相当一致.  相似文献