Regulation of Tilapia metallothionein gene expression by heavy metal ions   总被引：4，自引：0，他引：4  

Cheung AP  Lam TH  Chan KM 《Marine environmental research》2004,58(2-5):389-394

Tilapia is a common fish species inhabiting inland waters and estuarine regions in Hong Kong and Southeast Asia, and useful for bio-monitoring of metal pollution. Metallothionein (MT) gene expression in fish tissues has been useful to sub-lethal risk assessment as biomarker of exposure to metal ions in fishes inhabiting metal contaminated area. To investigate metal inductions of Tilapia MT gene expression in vivo, Tilapias were injected with different concentrations of heavy metals and tissues were then removed for quantitative PCR assay using mimic PCR methods. All of the metal ions tested (Cu(2+), Cd(2+), Hg(2+), Ni(2+), Pb(2+) and Zn(2+)) were able to induce hepatic MT mRNA levels. Renal MT mRNA levels of Cd(2+) and Zn(2+) treated fish was not induced with significant fold induction, however MT mRNA levels in gills were sensitive to the administrations of these metal ions. These data indicated that Tilapia MT mRNA levels in gills and liver are sensitive biomarker of exposure to various metal ions.  相似文献   

Comparison of polycyclic aromatic hydrocarbon distributions and sedimentary organic matter characteristics in contaminated, coastal sediments from Pensacola Bay, Florida     

Simpson MJ  Chefetz B  Deshmukh AP  Hatcher PG 《Marine environmental research》2005,59(2):139-163

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in a contaminated coastal area and the characteristics of the natural organic matter in tandem. We present a detailed study of PAH concentration, distribution, and organic matter characteristics of three core samples from Pensacola Bay, Florida. Solid-state 13C Nuclear Magnetic Resonance (NMR), pyrolysis gas chromatography coupled with mass spectrometry (GC-MS), and tetramethyl ammonium hydroxide (TMAH) thermochemolysis GC-MS were applied to obtain structural details about the sedimentary organic matter. Elemental compositions (carbon and nitrogen) and estimates of black carbon contents are also reported. These coastal sediments were found to contain more PAHs in the upper 15 cm layers than in the bottom 15-25 cm samples. The samples that contained the most PAHs also contained the least amount of aromatic carbon and contained a significant amount of paraffinic carbon. Lignin-derived pyrolysis and TMAH thermochemolysis products were abundant and generally higher in all of the samples in comparison to those reported for modern coastal sediments, indicating a large flux of terrestrial carbon. The black carbon contents were found to range from 4.3% to 6.8%, which are significantly lower than other reports of black carbon in sediments, which represent as much as 65% of the total organic carbon content. The low black carbon content suggests that this type of refractory carbon may not be as responsible for regulating PAH distribution as indicated by other researchers.  相似文献   

Inhibition of coral fertilisation and larval metamorphosis by tributyltin and copper     

Negri AP  Heyward AJ 《Marine environmental research》2001,51(1):17-27

Fertilisation and larval metamorphosis of reef-building corals are important life history events leading to recruitment of juvenile corals to reef populations. Little is known of the sensitivity of these early life phases to pollution, or their relative susceptibility to certain toxicants compared with established coral colonies. Inhibition of fertilisation and larval metamorphosis of the coral Acropora millepora (Ehrenberg, 1834) was assessed in response to solutions of the antifoulants tributyltin (TBT) and copper (Cu) using laboratory-based bioassays. Nominal concentrations that inhibited 50% fertilisation and metamorphosis (IC50) were calculated from 4 h fertilisation and 24 h metamorphosis assays and were based on introduced dose. Cu was most potent towards fertilisation with an IC50 of 17.4 micrograms/l. TBT however, proved more toxic to larval metamorphosis having an IC50 of 2.0 micrograms/l. Inert surfaces coated with either Cu- or TBT-based antifouling paint also inhibited fertilisation and metamorphosis. The degree of inhibition was correlated with surface area of the paint coating. These results indicate fertilisation and metamorphosis of coral can be sensitive to active components of antifouling paints.  相似文献   

小波变换阈值去噪法在GPS数据处理中的应用     

侯林锋  肖本林  胡友健  孙贤斌  刘正才 《全球定位系统》2008,33(6):58-63

在介绍小波变换阈值去噪法的特性及其有点的基础上,结合武汉某大学教学楼GPS变形监测数据,首先使用不同的小波函数及阈值策略分别对GPS观测数据的非差、单差相位观测值和伪距观测值进行阈值去噪处理,然后分别使用Bernese高精度数据处理和Trimble TG0软件对消噪前后的单差相位观测值、非差相位观测值和伪距观测值进行基线解算。最后,比较消噪前后基线解算结果,分析不同小波函数和阂值策略对基线解算精度的影响,探讨小波变换阅值去噪的合理方法。  相似文献   

大洋中锰的地球化学     

Lisi.  AP 杨子元 《冶金地质动态》1990,(5):29-33

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St. Vincent and the Grenadines     

Mills AP 《Marine pollution bulletin》2001,42(12):1208-1220

Saint Vincent and the Grenadines conjures up images of a yachting haven and a quiet tourists' paradise. The conflicting demands of a growing population, a middle-income economy dominated by fishing, plantation agriculture and tourism, and environmental and social concerns, all contribute to marine stress on the limited, precious, but internationally important resources. While the vision exists to manage effectively coastal and offshore resources, the institutional, financial and social capital to achieve that vision is limited. Development of the fledgling partnerships between local communities, national governmental structures and the international research, government and donor organisations seems the best hope to conserve the environment and coastal livelihoods of the islands.  相似文献   

Contamination by organochlorine compounds in walleye pollock (Theragra chalcogramma) from the Bering Sea, Gulf of Alaska and the Japan Sea     

de Brito AP  Ueno D  Takahashi S  Tanabe S 《Marine pollution bulletin》2002,44(2):172-177

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The Mars oxidant experiment (MOx) for Mars '96     

McKay CP  Grunthaner FJ  Lane AL  Herring M  Bartman RK  Ksendzov A  Manning CM  Lamb JL  Williams RM  Ricco AJ  Butler MA  Murray BC  Quinn RC  Zent AP  Klein HP  Levin GV 《Planetary and Space Science》1998,46(6-7):769-777

The MOx instrument was developed to characterize the reactive nature of the martian soil. The objectives of MOx were: (1) to measure the rate of degradation of organics in the martian environment; (2) to determine if the reactions seen by the Viking biology experiments were caused by a soil oxidant and measure the reactivity of the soil and atmosphere: (3) to monitor the degradation, when exposed to the martian environment, of materials of potential use in future missions; and, finally, (4) to develop technologies and approaches that can be part of future soil analysis instrumentation. The basic approach taken in the MOx instrument was to place a variety of materials composed as thin films in contact with the soil and monitor the physical and chemical changes that result. The optical reflectance of the thin films was the primary sensing-mode. Thin films of organic materials, metals, and semiconductors were prepared. Laboratory simulations demonstrated the response of thin films to active oxidants.  相似文献   

部分变量误差模型的极大似然估计     

于子龙  胡友健  汪奇生  肖本林 《测绘工程》2021,30(4):26-34

针对变量误差模型系数矩阵含有常数项的情况,部分变量误差模型在平差时只提取系数矩阵中的随机元素进行处理,较大程度的减少了参数估计的个数.为了进一步提高部分变量误差模型的参数估计效率,文中根据极大似然估计原理提出了一种部分变量误差模型的极大似然估计算法,并分析和比较了该算法与文献中几种算法的关系,证明算法之间的等价性.最后采用两个算例进行验证,结果表明文中算法能取得与已有算法一致的结果,而且具有迭代格式简单,计算效率高的优点.  相似文献   

Use of fluorescein as a ground water tracer in brackish water aquifers     

Chua LH  Robertson AP  Yee WK  Shuy EB  Lo EY  Lim TT  Tan SK 《Ground water》2007,45(1):85-88

A drift and pumpback experiment was conducted in a brackish water sandfill. The sandfill was reclaimed from the sea in the eastern part of Singapore and contains sands with low organic and clay/silt contents. The high salinity in the ground water precludes the use of chloride and bromide as tracers in such an environment, and a field experiment was conducted to assess the viability of using fluorescein as a tracer in brackish water aquifers. Nitrate was used as a second tracer to serve as a check. Initial laboratory studies showed that fluorescence was unaffected over the range of electrical conductivity and pH of the ground water. Results from the field experiment show that fluorescein appears to behave conservatively.  相似文献