The significance of dilution in evaluating possible impacts of wastewater discharges from large cruise ships

In response to public concerns about discharges from large cruise ships, Alaska's Department of Environmental Conservation (ADEC) sampled numerous effluents in the summer of 2000. The data showed that basic marine sanitation device (MSD) technology for black water (sewage) was not performing as expected. Untreated gray water had high levels of conventional pollutants and surprisingly high levels of bacteria. Both black water and gray water discharges sometimes exceeded state water quality standards for toxicants. The state convened a Science Advisory Panel (the Panel) to evaluate impacts associated with cruise ship wastewater discharges. The effluent data received wide media coverage and increased public concerns. Consequently, legislative decisions were made at the State and Federal level, and regulations were imposed before the Panel completed its evaluation. The Panel demonstrated that following the rapid dilution from moving cruise ships, the effluent data from the Summer of 2000 would not have exceeded water quality standards, and environmental effects were not expected.     

雅鲁藏布江缝合带内韧性剪切带的地质特征及其意义

阐述了雅鲁藏布江缝合带内发现的巨型韧性剪切带的规模、构造分带性及其地质特征,指出了膝折构造带与低温高压变质带以及韧性剪切带的成因关系,阐明了缝合带内韧性剪切带在板块俯冲时的空间位置及其构造地质意义。     

底水油层水平井产液剖面均衡性评价

胜利油田开采底水特征高含水油层的水平井数量多,其中油层向水平井非均衡供液现象普遍。为评价此类水平井产液剖面均衡性,量化其生产动态改善潜力,定义了产液剖面基尼系数GN,并结合现场案例介绍其计算方法,随后统计胜利油田60口样本井,分析GN对见水时间t_RL和底水突破前累积产油量Q_RL的影响,最后据此对GN分级。计算和分析结果表明:GN可以整体表征实际非均衡产液剖面偏离理想均衡产液剖面的程度,通常取值0~1之间,数值越大,均衡性越差;划分GN>0.1为产液剖面不均衡,其样本井数54口,占比90%,以理想均衡产液状态为基准,t_RL和Q_RL分别至少有100%和69.5%的提升潜力。      

南越大陆架基岩中油,气藏的热液成因

在南越大陆架结晶基底的断层附近发现了油饱和花岗岩、这些花岗岩具有特征的热液交代作用和淋滤晕矿物共生组合。自然银、重晶石、含锌、铜和铁的氯化物的存在表明，矿化流体为深部成因。这些热蚀变花岗岩是一种可能的新型油，气储集层，这将会大为拓宽油，气勘探的领域。     

Use of slow-release fertilizer and biopolymers for stimulating hydrocarbon biodegradation in oil-contaminated beach sediments

Nutrient concentration and hydrocarbon bioavailability are key factors affecting biodegradation rates of oil in contaminated beach sediments. The effect of a slow-release fertilizer, Osmocote, as well as two biopolymers, chitin and chitosan, on the bioremediation of oil-spiked beach sediments was investigated using an open irrigation system over a 56-day period under laboratory conditions. Osmocote was effective in sustaining a high level of nutrients in leached sediments, as well as elevated levels of microbial activity and rates of hydrocarbon biodegradation. Chitin was more biodegradable than chitosan and gradually released nitrogen into the sediment. The addition of chitin or chitosan to the Osmocote amended sediments enhanced biodegradation rates of the alkanes relative to the presence of Osmocote alone, where chitosan was more effective than chitin due to its greater oil sorption capacity. Furthermore, chitosan significantly enhanced the biodegradation rates of all target polycyclic aromatic hydrocarbons.     

Array technology as a tool to monitor exposure of fish to xenoestrogens

A variety of anthropogenic chemicals are capable of binding to the estrogen receptor of vertebrate species. Binding of these compounds can interfere with homeostasis by disrupting normal gene expression patterns. The purpose of this study was to investigate the feasibility of applying array technology as a monitoring tool for detecting the presence and distribution of estrogenic compounds in coastal habitats using sheepshead minnows as our model. cDNA clones that were isolated from differential display, including vitellogenin alpha and beta, vitelline envelope protein (ZP2), and transferrin, among others, were spotted on the macroarray. The results of these experiments demonstrate a characteristic expression pattern of estrogen responsive genes in sheepshead minnows exposed to 17 beta-estradiol (E2).     

Hepatic metallothionein as a biomaker for metal contamination: age effects and seasonal variation in European flounders (Pleuronectes flesus) from the Severn Estuary and Bristol Channel

Hepatic concentrations of metallothionein [MT] and three metals (Cu, Zn, Cd) were determined in 242 European flounders (Pleuronectes flesus) collected from power stations at Oldbury-upon-Severn and Hinkley Point, located in Severn Estuary and Bristol Channel, UK, respectively, between March 1996 and February 1998. A model involving three-factor analysis of variance (ANOVA) was used to examine variation in MT and metal concentrations with respect to season, year and site; with age-class included as a covariate in the analysis. Hepatic concentrations of MT and Cd (and to some degree, Cu, but not Zn) increased significantly with age. The model explained 38, 25, 17 and 26% of the variation in MT, Cu, Zn and Cd, respectively, with significant effects due to season, and to a lesser extent, to year. Site was only a significant factor for Cd which was higher in fish from Hinkley. Correlation between the individual concentration of MT and each metal alone, or in combination, was poor, and explained only an additional 3.0% of the residual variation in MT, most of which was attributable to Cu (2.7%). Compared to other industrialised estuaries, Cd concentrations were high (>20 micro g-1 in some individuals). The study emphasises the importance of seasonal variation and other factors in biomonitoring programmes and highlights the limitations of using [MT] as a biomarker for metal contamination in flounders from the Severn Estuary.     

Possible role of oceanic heat transport in early Eocene climate

Increased oceanic heat transport has often been cited as a means of maintaining warm high-latitude surface temperatures in many intervals of the geologic past, including the early Eocene. Although the excess amount of oceanic heat transport required by warm high latitude sea surface temperatures can be calculated empirically, determining how additional oceanic heat transport would take place has yet to be accomplished. That the mechanisms of enhanced poleward oceanic heat transport remain undefined in paleoclimate reconstructions is an important point that is often overlooked. Using early Eocene climate as an example, we consider various ways to produce enhanced poleward heat transport and latitudinal energy redistribution of the sign and magnitude required by interpreted early Eocene conditions. Our interpolation of early Eocene paleotemperature data indicate that an approximately 30% increase in poleward heat transport would be required to maintain Eocene high-latitude temperatures. This increased heat transport appears difficult to accomplish by any means of ocean circulation if we use present ocean circulation characteristics to evaluate early Eocene rates. Either oceanic processes were very different from those of the present to produce the early Eocene climate conditions or oceanic heat transport was not the primary cause of that climate. We believe that atmospheric processes, with contributions from other factors, such as clouds, were the most likely primary cause of early Eocene climate.     

Evidence for a Black Hole and Accretion Disk in the LINER NGC 4203

We examine the supernova remnant SNR 0540-697 in the Large Magellanic Cloud (LMC) using data from the Chandra Advanced CCD Imaging Spectrometer. The X-ray emission from this supernova remnant (SNR) had previously been hidden in the bright emission of the nearby X-ray binary LMC X-1; however, new observations with Chandra can finally reveal the SNR's structure and spectrum. We find the SNR to be a thick-shelled structure about 19 pc in diameter, with a brightened northeast region. Spectral results suggest a temperature of 0.31 keV and an X-ray luminosity (0.3-3.0 keV) of 8.4x1033 ergs s(-1). We estimate an age of 12,000-20,000 yr for this SNR, but note that this estimate does not take into account the possibility of cavity expansion or other environmental effects.