Zinc concentration effect at the organismal,cellular and subcellular levels in the eastern oyster

The purpose of this research was to demonstrate a concentration effect of zinc exposure at organismal, cellular and sub-cellular levels in the eastern oyster and to find associated protein expression signatures (PES) for each concentration of zinc. Oysters were exposed to six concentrations of zinc for 48 h in a controlled environment. At the organismal level, fecal material was observed as a measure of physiological health during metal exposures. At the cellular level, lysosomal destabilization was measured using hemolymph. This cellular response was significant only at the highest concentration, when the fecal index was lowest. Protein responses were monitored in the oyster following exposure to zinc. Gill tissue was excised and homogenized, and then analyzed using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and digital image analysis. Protein expression signatures were found to be specific to each concentration. The protein responses were linked to the other biological parameters measured, each of which followed a concentration gradient of zinc.     

Gill surface architecture of mullet, Mugil soiuy (Basilewsky): A scanning electron microscope study

Specimens of Mugil soiuy were collected from the coastal waters of Bohai Sea in Tianjin. The gillfilaments were cut with fine scissors and soaked for 24h in a fixative consisting of 2.5% glutaralde-hyde in 0.1 mol l~(-1) phosporic acid buffer. After three washes in a buffer solution the tissue was fixedin a mixture of 1% osmium tetraoxide at 4℃ for 1h. The tissue was dehydrated in graded ethandethanols and dried. The tissue was examined and photographed with an SEM at an accelerating voltage     

Contaminant concentrations and toxicity of sea-surface microlayer near Los Angeles, California

Sea-surface microlayer samples were collected from six nearshore areas receiving different amounts of anthropogenic inputs. The samples were analyzed for selected trace metals, chlorinated hydrocarbons, and polycyclic aromatic hydrocarbons. The relative toxicities of the samples were determined with fish embryo bioassays.Contaminant concentrations generally increased from offshore to the inshore stations. Contaminant concentrations were several orders of magnitude higher in microlayer samples from the highly industrialized Los Angeles and Long Beach harbors compared to samples from a site 15km offshore. Microlayer samples from the inshore stations were significantly more toxic, and induced significantly more developmental abnormalities and chromosome aberrations, than samples from the offshore stations.     

钝顶螺旋藻部分原生质体及单细胞的制备与培养

于1992年1月-1994年4月，进行超声波处理方法制备钝顶螺旋藻部分原生质体以作为基因工程受体，以及制备单细胞用于固体平板克隆化培养的研究。研究结果表明：超声波以20kHz频率、15W功率作用30s，可使藻丝体断裂成15．0±1．6个细胞长度；延长作用时间，至2－6个细胞长度时，细胞壁结构遭到破坏，形成部分原生质体；继续作用，可形成少量原生质体和大量单细胞。断裂藻丝体、部分原生质体、单细胞以及原生质体均可涂布于固体培养基上再生或生长。以一定密度涂布单细胞与原生质体，能够形成彼此分开的单个克隆，可用于筛选及遗传分析。本文提供了一种节省溶菌酶的制备螺旋藻透性体的方法，超声波作用利于外源基因的导入，而涂布培养利于进一步的筛选和形成克隆。     

口服免疫药物后中国对虾某些血淋巴因子的测定及方法研究

于１９９１年４－９月，以海捕中国对虾亲虾及养殖中国对虾为材料，运用单向免疫扩散（ＳＲＩＤ）方法测定对虾血淋巴免疫因子，并采用经改进后的Ｈｏｒｏｗｉｔｚ等人的方法测定对虾体内的酚氧化酶（ＰＯ）活性，目的在于运用该两种方法对口服不同免疫药物的养殖对虾的血淋巴免疫因子及ＰＯ活力进行测定。对亲虾和养殖对虾口服不同免疫药物前后的测定结果表明，几种情况下的对虾血淋巴中均存在类似ＩｇＭ的因子，血细胞中存在酚氧化     

自主式水下机械手系统研究

本文从水下机械手的总体设计，关节直流电机的驱动和调速，手臂上声纳的水下搜索与跟踪，机械手系统的智能控制和电源等几个方面，介绍了有关自主式水下机械手系统的研究，可为研制自主式水下作业系统提供参考     

A general method for calculating three-dimensional laminar and turbulent boundary layers on ship hulls

A general method for representing the flow properties in the three-dimensional boundary layers around ship hulls of arbitrary shape is described. It makes use of an efficient two-point finite-diffirence schem to solve the boundary-layer equations and includes an algebraic eddy-viscosity representaion of the Reynolds-stress ternsor. The numericzal method contains novel and desirable features and allows the calculation of flows in which the circumferential velocity component contains regions of flow reversal across the boundary layer. The inviscid pressure distribution is determined with the Douglas-Neumann method which, if necessary, can conveniently allow for the boundary-layer displacement surface. To allow its application to ships, and particularly to those with double-elliptic and flat-bottomed hulls, a non-orthogonal coordinate system has been developed and is shown to be economical, precise and comparatively easy to use. Present calculations relate to zero Froude number but they can be extended to include the effects of a water wave and local regions of flow separation which may stem from bulbous-bow geometries.     

High-resolution acoustic mapping of shallow gas in unconsolidated sediments beneath the strait of Georgia,British Columbia

Gassy sediments are detectable acoustically in subbottom profiles of Canada's Fraser Delta slope and prodelta areas. Interstitial gas is typically represented by zones of acoustic turbidity on high-resolution seismic profiles and by gas brightening on air-gun profiles. The top of the acoustically turbid zone is generally highest within the sediment column closest to the river mouths and lies within 10 ms (two-way travel time) of the sea floor in a nearly continuous area that covers over 530 km². Most of the gas is believed to be biogenic in origin, although thermogenic gas derived from underlying Tertiary sedimentary rocks may be present in places.     

Secondary flow caused by differential roughness,Langmuir circulations,and their effect on the development of sand ribbons

The process of Differential Roughness Secondary Flow (DRSF), hitherto little recognized, recently was demonstrated in a wind tunnel and in a flume. It is suggested here the DRSF may, in the natural environment, play an important part in the persistence and sharp definition of sand ribbons, previously initiated by other processes. In 1980 Karl described a series of sand ribbons, alternating with exposed substrate, which he attributed to the effect of Langmuir circulations. Although Langmuir Circulation Secondary Flow (LCSF) may indeed, in some cases, initiate sand ribbons, the sharply-defined edges typical of these features are explained better by DRSF.