Molecular identification of scallop planktonic larvae using species-specific microsatellites

The identification of scallop larvae is essential to understand the population structure and community dynamics and to assess the potential environmental impacts caused by scallop larvae released or escaped. However, the larvae identification by morphological characteristics is notoriously difficult, mainly due to the small size （usually being less than 150 μm） and vague morphological characteristics among different scallop species. A simple and accurate molecular method was developed to identify four economically farmed scallop species, the Zhikong scallop Chlamys farreri, the noble scallop C. nobilis, the bay scallop Argopecten irradians and the Yesso scallop Mizuhopecten yessoensis. The tests used the high degree of species-specific microsatellite markers, which was specified by transferability analyses, assessed by reference individuals and evaluated by BLAST searches. The sensitivity test indicated that the species-specific microsatellites were sensitive enough for the detection of 1% -2% larvae in mixed plankton samples. Larvae collected from scallop hatcheries and their effluents and from the artificially controlled crosses were well identified to the species/hybrid level. The results demonstrated that the one-step PCR-based assay was technically simple, inexpensive and robust in identification analyses, and also less sensitive to initial quality of template DNA extracted from the ethanol-preserved samples for several years.     

A study of SAR remote sensing of internal solitary waves in the north of the South China Sea:I.Simulation of internal tide transformation

For settlement of the well-known problem of contemporary radar imaging models,i.e.,the pmblem of a general underestimation of radar signatures of hydrodynamic features over oceanic internal waves and underwater bottom topography in tidal watels at at high radar frequency bands(X-band and C-band),the impact of the ocean surface mixed layer turbulence and the significance of strat-ified oceanic model on SAR remote sensing of internal solitary waves are proposed.In the north of the South China Sea by utilizing seme observed data of background field the nonlinearity coefficient,the dispersion coefficient,the horizontal variability coefficient and the phase speed in the generalized K-dV equation are determined approximately.Through simulations of internal tide transfor-mation the temporal evolution and spatial distribution of the vertical displacement and horizontal velocity of intereal wave field are obtained.The simulation results indicate that the maximum amplitudes of internal solitary waves occur at depth 35 m,but the maximum current speeds take place at depth 20 m in this area of the sea(about 20°30'N,114°E)in August.It was noticed that considering the effects of flood current and ebb current respectively is appropriate to investigate influence of the background shear flow on coefficients of the K-dV equation.The obtained results provide the possibility for the simulation of SAR signatures of inter-nal solitary waves under considering the impact of ocean surface mixed layer turbulence in the companion paper.     

<Superscript>234</Superscript>Th/<Superscript>238</Superscript>U disequilibrium and particulate organic carbon export in the northern South China Sea

We utilized ²³⁴Th, a naturally occurring radionuclide, to quantify the particulate organic carbon (POC) export rates in the northern South China Sea (SCS) based on data collected in July 2000 (summer), May 2001 (spring) and November 2002 (autumn). Th-234 deficit was enhanced with depth in the euphotic zone, reaching a subsurface maximum at the Chl-a maximum in most cases, as commonly observed in many oceanic regimes. Th-234 was in general in equilibrium with ²³⁸U at a depth of ∼100 m, the bottom of the euphotic zone. In this study the ²³⁴Th deficit appeared to be less significant in November than in July and May. A surface excess of ²³⁴Th relative to ²³⁸U was found in the summer over the shelf of the northern SCS, most likely due to the accumulation of suspended particles entrapped by a salinity front. Comparison of the ²³⁴Th fluxes from the upper 10 m water column between 2-D and traditional 1-D models revealed agreement within the errors of estimation, suggesting the applicability of the 1-D model to this particular shelf region. 1-D model-based ²³⁴Th fluxes were converted to POC export rates using the ratios of bottle POC to ²³⁴Th. The values ranged from 5.3 to 26.6 mmol C m⁻²d⁻¹ and were slightly higher than those in the southern SCS and other oligotrophic areas. POC export overall showed larger values in spring and summer than in autumn, the seasonality of which was, however, not significant. The highest POC export rate (26.6 mmol C m⁻²d⁻¹) appeared at the shelf break in spring (May), when Chl-a increased and the community structure changed from pico-phytoplankton (<2 μm) dominated to nano-phytoplankton (2–20 μm) and micro-phytoplankton (20–200 μm) dominated.     

应用能量色散X荧光衍射仪分析海绵元素组成

通过能量色散X荧光衍射仪（EDXRF）对3种南海潮间带海绵：细薄星芒海绵Stelletta tenui（Lindgren）、澳大利亚厚皮海绵Craniella australiensis （Carter）和多皱软海绵Halichondria hugosa （Ridley＆Dendy）的元素组成和含量进行了研究,并与两种黄海潮间带海绵进行了比较。结果表明,海绵体内的元素组成受种属差异的影响较大,溴元素的含量可能同一定的活性物质产生相关。另外,不同海绵具有骨针形态的多样性,为深入研究内部合成机制提供了材料。     

地下卤水中镭的富集与测定方法研究

以自配人工卤水,采用硫酸钡（镭）共沉淀法富集其中的镭,同时用γ谱仪同步测量^226Ra和^228Ra的含量。不同pH和共沉淀剂作用下的化学及放化回收率计算表明,该方法操作简单,回收率高,适用于地下卤水及其它水体较高含量^226Ra、^228Ra的同步测定。用该方法测定的莱州湾地下卤水^226Ra和^228Ra含量分别为0．341Bq／L和1．615Bq／L,远高于海水中镭的含量。     

牙鲆孵化酶的分离纯化及其部分生物化学性质研究

利用凝胶过滤柱层析和阴离子交换柱层析技术,从牙鲆（Paralichthys olivaceus）胚胎孵化液中分离纯化出了大小约为34．8ku的牙鲆孵化酶。该酶卵膜裂解的最适反应温度为35℃,最适pH为7．0;对底物酪蛋白的米氏常数Km值为1．53mmol／L。该酶对丝氨酸蛋白酶和胰蛋白酶的特异性抑制剂非常敏感,而对其他蛋白酶抑制剂不敏感,表明该酶极可能是一种丝氨酸蛋白酶类型的胰蛋白酶。此外,该酶可浓度依赖性地被EDTA所抑制,被Cu^2＋所强烈抑制,被Ca^2＋和Mg^2＋所激活,对Zn^2＋则不敏感,表明该酶很可能是一种金属蛋白酶。     

苏北潮滩的近期变化分析

利用1999～2000年条子泥岸滩剖面实测数据和1982～1983年东沙沙滩剖面资料,分析了条子泥岸滩和东沙沙滩剖面的冲淤变化。结果表明,条子泥陆侧岸滩剖面的季节性变化特点是夏季侵蚀,冬季淤积;东沙沙脊年际变化特点为两侧边缘以侵蚀为主,而沙脊中央则以淤积为主。造成条子泥岸滩剖面季节性差异的主要原因是其周围海域中高浓度悬沙的秋、冬季落淤大于夏季所致。东沙沙脊东西两侧强烈的潮流和波浪作用使沙脊的两侧遭受较为明显的侵蚀。     

文蛤抗癌多肽对N-乙酰-β-D氨基葡萄糖苷酶活力的影响

从文蛤体中分离纯化得到了抗癌多肽,研究该多肽对N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)活力的影响,结果显示文蛤抗癌多肽对该酶有明显的抑制作用.在本文中,我们将深入地研究其抑制作用机理和抑制效应类型,结果表明:随着文蛤多肽加入量的增大,该酶活力呈指数下降,测得导致酶活力下降50%的抑制剂浓度(IC50)为112.9 μg/cm3,该多肽对酶的抑制作用是一种可逆过程,抑制机理表现为混合型抑制类型,对游离酶(E)的抑制常数(KI)和酶-底物络合物的抑制常数(KIS)分别为77.03和697.44μg/cm3,说明文蛤抗癌多肽与游离酶的结合导致酶活力的丧失,明显的强于对酶-底物络合物的抑制效应,底物的存在对该酶被文蛤抗癌多肽抑制作用起了保护作用.     

黄东海表观光学量与固有光学量经验模式研究

表观光学特性和固有光学特性是海洋光学研究领域的两大主要研究内容。文中通过2003年黄东海试验和2007年908专项海洋光学调查所获取的表观光学参数中的遥感反射率Rrs(λ)、水下遥感反射率rrs(λ)、海水透明度Zs、下行辐照度漫衰减系数Kd(490)、固有光学参数中的后向散射系数bb(λ)和水体吸收系数a(λ),建立了区域性、季节性的表观光学量和固有光学量之间的经验模式,并对模式进行了误差分析和改进。