Sequences Characterization of Microsatellite DNA Sequences in Pacific Abalone (Haliotis discus hannat)     

LI Qi  Kijima Akihiro 《中国海洋大学学报(英文版)》2007,6(1)

The microsatellite-enriched library was constructed using magnetic bead hybridization selection method, and the microsatellite DNA sequences were analyzed in Pacific abalone Haliotis discus hannai. Three hundred and fifty white colonies were screened using PCR-based technique, and 84 clones were identified to potentially contain microsatellite repeat motif. The 84 clones were sequenced, and 42 microsatellites and 4 minisatellites with a minimum of five repeats were found (13.1% of white colonies screened). Besides the motif of CA contained in the oligoprobe, we also found other 16 types of microsatellite repeats including a dinucleotide repeat, two tetranucleotide repeats, twelve pentanucleotide repeats and a hexanucleotide repeat. According to Weber(1990), the microsatellite sequences obtained could be categorized structurally into perfect repeats (73.3%), imperfect repeats(13.3%), and compound repeats (13.4%). Among the microsatellite repeats, relatively short arrays (＜ 20 repeats) were most abundant,accounting for 75.0%. The largest length of microsatellites was 48 repeats, and the average number of repeats was 13.4. The data on the composition and length distribution of microsatellites obtained in the present study can be useful for choosing the repeat motifs for microsatetlite isolation in other abalone species.  相似文献   

Petrology and geochemistry of peridotites from IODP Site U1309 at Atlantis Massif, MAR 30°N: micro- and macro-scale melt penetrations into peridotites     

Akihiro Tamura  Shoji Arai  Satoko Ishimaru  Eric S. Andal 《Contributions to Mineralogy and Petrology》2008,155(4):491-509

Peridotite samples recovered from IODP Site U1309 at the Atlantis Massif in the Mid-Atlantic Ridge were examined to understand magmatic processes for the oceanic core complex formation. Original peridotite was fragmented, and the limited short peridotite intervals are now surrounded by a huge gabbro body probably formed by late-stage melt injections. Each peridotite interval has various petrographical and geochemical features. A spinel harzburgite in contact with gabbro shows evidence of limited melt penetrations causing gradual compositional change, in terms of trace-element compositions of pyroxenes, as well as modal change near the boundary. Geochemistry of clinopyroxenes with least melt effects indicates that the harzburgite is originally mantle residue formed by partial melting under polybaric conditions, and that such a depleted peridotite is one of the components of the oceanic core complex. Some of plagioclase-bearing peridotites, on the other hand, have more complicated origin. Although their original features were partly overprinted by the injected melt, the original peridotites, both residual and non-residual materials, were possibly derived from the upper mantle. This suggests that the melt injected around an upper mantle region or into mantle material fragments. The injected melt was possibly generated at the ridge-segment center and, then, moved and evolved toward the segment end beneath the oceanic core complex.  相似文献   

Pleistocene geochemical stratigraphy of the borehole 1317E (IODP Expedition 307) in Porcupine Seabight,SW of Ireland: applications to palaeoceanography and palaeoclimate of the coral mound development     

Xianghui Li  Chiduru Takashima  Akihiro Kano  Saburo Sakai  Yunhua Chen  Baoliang Xu  Iodp Expedition Scientists 《第四纪科学杂志》2011,26(2):178-189

Stable isotopes and element compositions of the fine‐grained matrix were measured for IODP Expedition 307 Hole U1317E drilled from the summit of Challenger Mound in Porcupine Seabight, northeast Atlantic, to explore the palaeoceanographic and palaeoclimatic background to development of the deep‐water coral mound. The 155 m long mound section was divided into two units by an unconformity at 23.6 mbsf: Unit M1 (2.6–1.7 Ma) and Unit M2 (1.0–0.5 Ma). Results from 519 specimens show a difference in δ¹³C value between Unit M1 (?0.6‰ to ?5.0‰) and Unit M2 (?1.0‰ to 1.0‰), but such a distinct difference was not seen in δ¹⁸O values (1.0‰–2.5‰), CaCO₃ content (40–60 wt%), Sr/Ca ratio (2.0–8.0 mmol mol^?1), and Mg/Ca ratio (10.0–20.0 mmol mol^?1) through the mound. Positive δ¹⁸O and negative δ¹³C shifts at the mound base are consistent with the oceanographic changes in the northeast Atlantic at the beginning of the Quaternary. The positive δ¹³C regression in Unit M2 suggests a linkage to the mid Pleistocene intensified glaciation in the Northern Hemisphere. Warm Mediterranean Upper Core Water of Mediterranean Outflow Water, Eastern North Atlantic Water and cold Labrador Sea Water of North Atlantic Deep Water are key oceanographic features that cause spikes and shifts in stable isotope and element composition. However, the stable isotope values of the sediment matrix could not primarily record the glacial–interglacial eustatic/temperature change, but indirectly indicate current regimes of the intermediate oceanic layer where the coral mound grew. Similarly, elemental ratios and CaCO₃ content may not represent the productivity and temperature of surface sea water, respectively, but superpose the fractions from both surface and bottom water. It is concluded that palaeoceanographic change coupled to the Pleistocene glacial/interglacial cycles is a key control on the geochemical stratigraphy of the matrix sediments of the carbonate mound developed in Porcupine Seabight. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Positive electrification on the floor of an underground mine gallery at the arrival of seismic waves and similar electrification on the surface of partially stressed rocks in laboratory     

Akihiro Takeuchi  Yukako Futada  Kan Okubo  Nobunao Takeuchi 《地学学报》2010,22(3):203-207

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Real-time geophysical measurements on the deep seafloor usingsubmarine cable in the southern Kurile subduction zone     

Hirata  K. Aoyagi  M. Mikada  H. Kawaguchi  K. Kaiho  Y. Iwase  R. Morita  S. Fujisawa  I. Sugioka  H. Mitsuzawa  K. Suyehiro  K. Kinoshita  H. Fujiwara  N. 《Oceanic Engineering, IEEE Journal of》2002,27(2):170-181

A permanent real-time geophysical observatory using a submarine cable was developed and deployed to monitor seismicity, tsunamis, and other geophysical phenomena in the southern Kurile subduction zone. The geophysical observatory comprises six bottom sensor units, two branching units, a main electro-optical cable with a length of 240 km and two land stations. The bottom sensor units are: 1) three ocean bottom broadband seismometers with hydrophone; 2) two pressure gauges (PGs); 3) a cable end station with environmental measurement sensors. Real-time data from all the undersea sensors are transmitted through the main electro-optical cable to the land station. The geophysical observatory was installed on the continental slope of the southern Kurile trench, southeast Hokkaido, Japan in July 1999. Examples of observed data are presented. Sensor noises and resolution are mentioned for the ocean bottom broadband seismometers and the PGs, respectively. An adaptable observation system including very broadband seismometers is scheduled to be connected to the branching unit in late 2001. The real-time geophysical observatory is expected to greatly advance the understanding of geophysical phenomena in the southern Kurile subduction zone  相似文献   

An interpretation of the Nusselt-Rayleigh number relationship for convection in a spherical shell     

Yasuyuki Iwase  Satoru Honda 《Geophysical Journal International》1997,130(3):801-804

Recent studies on the relationship between the Nusselt ( Nu ) and Rayleigh ( Ra ) numbers for base-heated convection in a spherical shell with a constant viscosity show that the power-law index is around 1/4, which is different from the value of 1/3 predicted by a simple boundary layer theory. We show that such a difference may be caused by the flow pattern due to the geometry. The flow pattern of the convection in a spherical shell at relatively low Ra , at least, less than 10⁶, is characterized by narrow upwelling and broad downwelling, which is similar to the opposite flow pattern of internally heated convection. Convection in the internally heated case predicts the power-law index of 1/4. We demonstrate this relationship based on the concept of 'local' Rayleigh ( Ra1 ) and Nusselt ( Nu1 ) numbers  相似文献   

Effects of the Anticyclonic Eddies on Water Masses, Chemical Parameters and Chlorophyll Distributions in the Oyashio Current Region     

Masashi Kusakabe  Andrey Andreev  Vyacheslav Lobanov  Igor Zhabin  Yuichiro Kumamoto  Akihiro Murata 《Journal of Oceanography》2002,58(5):691-701

Data from the R/V Mirai cruise (May–June 2000) have been examined to discover how mesoscale processes associated with eddy dynamics direct affect the water masses, the distributions and the vertical fluxes of the dissolved oxygen, nutrients and dissolved inorganic carbon in the western subarctic Pacific. Using maps of the temperature, salinity, dissolved oxygen, nutrients, chlorophyll and sea-air pCO₂ difference we show that the boundaries of the anticyclone eddies in the study region were composed of high productivity coastal Oyashio water. The coastal waters were wrapped around the anticyclone eddies (thus creating a high productivity belt) and intruded inside of them. Using SeaWifs data we demonstrate that temporal variations in the position and the strength of anticyclone eddies advected the Kuril island coastal high productivity waters to the pelagic part, resulting in temporal variations of the chlorophyll in the Oyashio region. Computed vertical fluxes of the dissolved oxygen (DO), inorganic carbon (DIC) and silicate show that the anticylonic eddies in the Kuroshio-Oyashio Zone are characterized by enhanced vertical fluxes of the DO and DIC between the upper (σ_θ = 26.7–27.0) and lower (σ_θ = 27.1–27.5) intermediate layer, probably due to the intrusions of the Oyashio waters into the eddies. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Evaluation of Seasonal Sea Level Variation at Syowa Station, Antarctica, Using GPS Observations     

Shigeru Aoki  Kazuo Shibuya  Akihiro Masuyama  Taku Ozawa  Koichiro Doi 《Journal of Oceanography》2002,58(3):519-523

Global Positioning System (GPS) measurements of the vertical displacement of fast ice near Syowa Station, Antarctica, were conducted between April and December 1998 to evaluate measurements of sea level variation derived with a conventional bottom pressure gauge (BPG). The BPG-derived sea level revealed a seasonal variation of about 0.13 m, with a high in April–June and a low in November–December. The GPS-derived sea level, combined with observed sea ice thickness, supported the BPG result, with an RMS error of 0.007 m. Our result also demonstrates that GPS is a powerful technique for monitoring sea level variations. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Density variations of Cr-rich garnets in the upper mantle inferred from the elasticity of uvarovite garnet     

Steeve Gréaux  Akihiro Yamada 《Comptes Rendus Geoscience》2019,351(2-3):95-103

The thermoelastic parameters of Ca₃Cr₂Si₃O₁₂ uvarovite garnet were examined in situ at high pressure up to 13 GPa and high temperature up to 1100 K by synchrotron radiation energy-dispersive X-ray diffraction within a 6-6-type multi-anvil press apparatus. A least-square fitting of room T data to a third-order Birch–Murnaghan (BM3) EoS yielded K₀ = 164.2 ± 0.7 GPa, V₀ = 1735.9 ± 0.3 ų (K’₀ fixed to 4.0). P–V–T data were fitted simultaneously by a modified HT-BM3 EoS, which gave the isothermal bulk modulus K₀ = 163.6 ± 2.6 GPa, K’₀ = 4.1 ± 0.5, its temperature derivative (?K_0,T/?T)_P = –0.014 ± 0.002 GPa K^?1, and the thermal expansion coefficients a₀ = 2.32 ± 0.13 ×10^?5 K^?1 and b₀ = 2.13 ± 2.18 ×10^?9 K^?2 (K’₀ fixed to 4.0). Our results showed that the Cr³⁺ enrichment in natural systems likely increases the density of ugrandite garnets, resulting in a substantial increase of mantle garnet densities in regions where Cr-rich spinel releases chromium through a metasomatic reaction.  相似文献   

Generation of electromotive force in igneous rocks subjected to non-uniform loading          下载免费PDF全文

Akihiro Takeuchi  &#  mer Aydan  Keizo Sayanagi  Toshiyasu Nagao 《地震科学（英文版）》2011,24(6):593-600

When one end of an air-dry igneous rock block was uniaxially loaded in laboratory, there appeared an electromotive force that made electric currents flow from the stressed volume to the unstressed volume. Quartz-free rocks such as gabbro also generated this force, stronger than quartz-bearing rocks such as granite. This indicates that the piezoelectric effect of quartz and the electrokinetic effect of pore water do not make a large contribution toward generating the electromotive force. We focus on peroxy bond that is one of the abundant lattice defects in igneous rock-forming minerals. When mechanical loading deforms the lattice structure around this defect and breaks its bond, its energy levels change and act like an accepter. As an electron is trapped at this defect from a neighbor O^2- site, a positive hole is activated there. They attempt to diffuse toward the unstressed volume through the valence band and are simultaneously affected by the attractive electric force with the electrons trapped in peroxy bonds. This leads to a polarization in the stressed volume and the generation of electromotive force between the stressed and unstressed volumes. Similar electromotive force may be generated in the Earth's crust where inhomogeneous stress/strain is changing.  相似文献