长牡蛎(Crassostrea gigas)微卫星克隆快速分离及特性分析

采用磁珠杂交选择和PCR筛选法，从长牡蛎DNA选择片段文库中，快速分离含有微卫星序列的阳性克隆。结果表明，在筛选的200个白色菌落中，56个克隆含有重复次数5以上的微卫星序列，其中41个(20．5％)有随机侧翼区，可以进行引物设计，12个缺乏足够的侧翼序列，3个为中断的微卫星序列。此外，还获得两个小卫星克隆。在获得的微卫星序列中，完全的占54．7％，不完全的占20．8％，复合的占24．5％。除探针中使用的CA重复单元外，还观察到CT、ACT、CGCA、CACT、GACT、GCAC、CCTTA和CCTCA的重复序列。微卫星重复次数主要集中在5-30次之间，占71．7％，最高为60次。本研究中构建的长牡蛎(CA)n富集微卫星文库将为以后开发未知微卫星标记提供帮助。     

Primary productivity in a cold water mass and the neighborhood area occurring off Enshu-nada in the late summer of 1989

Primary productivity off Enshu-nada was measured by the¹³C method in September 1989. Primary productivity was estimated in a cold water mass developed off Enshu-nada for the first time. The obtained value was 469 mgC·m^–2·d^–1 and higher than those in the pelagic area of Kuroshio, but equivalent to those in the neritic and the Oyashio areas. It was indicated that cold water mass is the place where organic matter is produced actively. Extremely high chlorophylla of more than 5g·l^–1 were found in the cold water mass. The high productivity was due to high standing crop of phyoplankton. Furthermore, calculated light efficiency and quantum yield showed consistent increase with depth and showed a maximum at 10% light level. Both were larger on the coastal side than those on the oceanic side of the Kuroshio current.     

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

1 Introduction Microsatellites or simple sequence repeats (SSRs) are tandemly repeated motifs of one to six bases found in all prokaryotic and eukaryotic genomes analysed to date (Zane et al., 2002). Due to their hyper-variable and co-dominant nature, relatively high abundance and random distribution in the genome, microsatellites are among the most efficient class of molecular markers. Such repeats display high polymorphism because of variation in repeat length and can be rapidly analysed t…     

Isotopic composition of dissolved inorganic carbon in subsurface sediments of gas hydrate-bearing mud volcanoes, Lake Baikal: implications for methane and carbonate origin

We report on the isotopic composition of dissolved inorganic carbon (DIC) in pore-water samples recovered by gravity coring from near-bottom sediments at gas hydrate-bearing mud volcanoes/gas flares (Malenky, Peschanka, Peschanka 2, Goloustnoe, and Irkutsk) in the Southern Basin of Lake Baikal. The δ¹³C values of DIC become heavier with increasing subbottom depth, and vary between ?9.5 and +21.4‰ PDB. Enrichment of DIC in ¹³C indicates active methane generation in anaerobic environments near the lake bottom. These data confirm our previous assumption that crystallization of carbonates (siderites) in subsurface sediments is a result of methane generation. Types of methanogenesis (microbial methyl-type fermentation versus CO₂-reduction) were revealed by determining the offset of δ¹³C between dissolved CH₄ and CO₂, and also by using δ¹³C and δD values of dissolved methane present in the pore waters. Results show that both mechanisms are most likely responsible for methane generation at the investigated locations.     

大气气溶胶的垂直非均一对向上亮度和卫星遥感地表反射率的效应

均一模式和两层模式是两个忽略气溶胶垂直非均一、并广泛用于卫星遥感的辐射模式。通过两个模式的数值模拟，分析了气溶胶的垂直非均一对向上天空亮度和卫星遥感地面反射率的效应。数值模拟选用了２４个有代表性的气溶胶模式。对于具有强分子散射的卫星短波通道，由于分子和气溶胶散射性的明显不同，应用均一和两层模式计算的向上亮度往往存在较大误差。对长波通道，如果气溶胶的光学特性随高度变化不大，该亮度误差较小，但如果存在不同散射相函数和一次散射反照率的气溶胶层，该误差仍可能较大。对于干净的大气，由均一和两层模式计算的亮度误差可分别高达３１．４％和３１．５％，而对于混浊的大气，该误差可分别高达６７．８％和５９．２％。该亮度误差可以引起地表反射率解存在大的不确定性，特别是对于短波通道和强吸收的气溶胶。对于包含强吸收气溶胶的混浊大气，均一和两层模式不适合于大气订正应用。     

Role of precursory less-viscous mixed magma in the eruption of phenocryst-rich magma: evidence from the Hokkaido-Komagatake 1929 eruption

During the 1929 activity of Hokkaido-Komagatake volcano, the Plinian eruption of a phenocryst-rich andesite was preceded by a small eruption of more mafic magma formed by magma mixing. A similar eruption sequence has been reported for some other eruptions (Pallister et al. 1996; Venezky and Rutherford 1997), suggesting that eruption of a mixed magma is a precursor of phenocryst-rich magmas. For the purpose of understanding the tapping processes of the phenocryst-rich magma chamber, we investigated the temporal variation in the erupted magma and estimated the viscosity and density of the end-member and mixed magmas with constraints drawn from petrography. For the precursory mixed magma we estimate 33dž vol.% phenocrysts, andesitic-dacitic melt composition, 3 wt.% H₂O content, and temperature of 1040°C. In comparison, for the climactic, silicic end-member magma we estimate 48Dž vol.% phenocryst, high-silica rhyolitic melt, 3 wt.% H₂O, and temperature of 950°C, respectively. The mafic end-member magma, which was not erupted, is thought to be an almost aphyric basaltic-andesitic magma, based on mass balance calculation of the phenocryst content. The proportion of the mafic end-member magma component in the mixed magma was calculated to be 20-40 wt.%. On the basis of these data, we estimate magma viscosities of 10^3.9, 10^6.9, and 10^2.0 Pa s for the mixed, silicic end-member, and mafic end-member magmas, respectively. The calculated density differences among these magmas are inconsequential when possible errors are considered. We calculate the minimum excess pressure required for dike propagation to be 31 MPa for the silicic end-member magma and 8 MPa for the mixed magma, using the estimated viscosity and dike propagation model of Rubin (1995). If we assume that excess pressure is limited by the wall rock strength of the magma chamber, excess pressure retainable in the magma chamber is less than ca. 20 MPa. This suggests that the mixed magma was able to ascend to the surface without freezing, whereas the viscous silicic end-member magma could not. The formation and precursory eruption of the mixed magma are, therefore, effective and necessary initiation processes for the phenocryst-rich, viscous magma eruption.     

Radiometrically determined skin temperature and scalar roughness to estimate surface heat flux. Part I: Parameterization of radiometric scalar roughness

A series of experiments carried out in a pasture field during a growing season, allowed a radiometric determination of the scalar roughness for sensible heatz _oh,r . The values ofz _oh,r are shown to vary over the range of 10^–1–10^–7m both diurnally and seasonally, and an existing theoretical model for the estimation of scalar roughness for sensible heat is found to be inappropriate for the precise estimation ofz _oh,r . To parameterizez _oh,r better, a multiple regression analysis was performed, with predictor candidates such as solar elevation, solar radiationR _s , leaf area index LAI, canopy height, the ratio of the solar radiation and the extraterrestrial radiationR _s /R _e , the ratio of the direct and the total solar radiationR _d /R _s , and the roughness Reynolds number among others. The best regression equation which usesR _s , LAI,R _s /R _e , andR _d /R _s is derived withr=0.75; with smaller numbers of predictors, values ofr tend to deteriorate gradually down tor=0.52 when only one predictor, LAI, was incorporated into the equation.     

Fatty acids and hydrocarbons in surficial sediments of Lake Huron

Fatty acid and hydrocarbon distributions in surficial sediments from ten locations in southern Lake Huron indicate both aquatic and terrigenous recent biological sources of these geolipid materials. Normal alkanoic acids appear to be derived primarily from aquatic sources whereas normal alkanes are from multiple origins. Geolipid distributions are determined by the nature of the biogenic source and are modified during transport and deposition. Sediments receiving urban runoff in Saginaw Bay contain large amounts of non-biogenic hydrocarbons of a petroleum or industrial nature.     

Magma mixing model for the genesis of middle crust in the Izu–Bonin–Mariana arc: evidence from plutonic rocks in the Mineoka-Setogawa ophiolitic mélange,central Japan

ABSTRACT

A Paleogene accretionary complex, the Mineoka–Setogawa belt is distributed adjacent to the northern portion of the collision zone between Honshu and Izu–Bonin–Mariana (IBM) arcs in central Japan, comprising a mélange of ophiolitic fragments of various sizes. The Eocene-Oligocene plutonic rocks in this belt (gabbro, diorite, and tonalite) have been interpreted as fragments brought from the deep crust beneath the IBM arc through tectonic collisions. The geochemical characteristics of the gabbro and associated basaltic dike are similar to those of the Eocene IBM tholeiitic basalt; thus, the gabbro was likely formed via the crystallization of the Eocene tholeiitic basaltic magmas, which was produced by the partial meltings of a depleted mantle wedge. A comparison with experimental results and geochemical modeling indicates that the tonalite was generated by 10–30% dehydration melting of the gabbro. Actually, Eocene–Oligocene felsic veins, which are coeval with the plutonic rocks, occur in the Mineoka–Setogawa gabbro. Plagioclase crystals in the diorite comprise Ca-rich and -poor parts in a single crystal. Their compositional characteristics are consistent with those of plagioclase in the gabbro and tonalite, respectively. The textures and chemical composition of plagioclase indicate that the diorite was formed by the mixing between mafic and silicic magmas. The whole-rock composition of the diorite also indicates the evidence for the mixing between basaltic magmas which were fractionated to variable degrees and homogeneous silicic magma. The mixing model proposed from the first direct observations of the IBM middle crust exposed on the Mineoka–Setogawa belt is applied to the genesis of the Eocene to present intermediate rocks in the IBM arc. If the continental crust were created at intra-oceanic arc settings such as the IBM arc, the magma mixing model would be one of the most likely mechanisms for the genesis of the continental crust.     

Study of the effect of water-soluble fractions of heavy-oil on coastal marine organisms using enclosed ecosystems,mesocosms

Mesocosm facilities composed of 4 experimental and 2 reservoir tanks (1.5 m in diameter, 3.0 m in depth and 5 tons in capacity) made of FRP plastics, were constructed in the concrete fish rearing pond in the Fisheries Laboratory, The University of Tokyo. The water-soluble fraction of Rank A heavy residual oil was formed by mixing 500 g of the oil with 10 l of seawater, which was introduced to the 5000 l-capacity tanks. Experimental Run 4 was conducted from May 31 to June 7, 2000. Oil concentrations in the tanks were 4.5 microg/l called LOW, and 13.5 microg/l, called HIGH tank. Bacterial growth rates very quickly accelerated in the HIGH tank just after the loading of oil which corresponded with a high increase of bacterial cells in the same tank after 2 days. Later, bacterial numbers in HIGH tank rapidly decreased, corresponding with the rapid increase of heterotrophic nano-flagellates and virus numbers on the same day. Sediment traps were deployed at the bottom of the experimental tanks, and were periodically retrieved. These samples were observed both under light microscope and epi-fluorescent microscope with UV-excitation. It was observed that the main components of the vertical flux were amorphous suspended matter, mostly originating from dead phytoplankton and living diatoms. It was further observed from the pictures that vertical transport of oil emulsions were probably conducted after adsorption to amorphous suspended matter and living diatoms, and were settling in the sediment traps at the bottom of the tanks. This means that the main force which drives the soluble fraction of oil into bottom sediment would be vertical flux of such amorphous suspended particles and phytoplankton. Further incubation of the samples revealed that the oil emulsions were degraded by the activity of autochtonous bacteria in the sediment in aerobic condition.