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1.
Environmental Science and Pollution Research - This study aims to re-examine the impacts of monetary and fiscal policy on environmental quality in ASEAN countries from 1990 to 2019. We utilized the...  相似文献   
2.
Introduced and cryptogenic species in Port Phillip Bay, Victoria, Australia   总被引:4,自引:0,他引:4  
Port Phillip Bay (PPB) is a large (1,930 km2), temperate embayment in southern Victoria, Australia. Extensive bay-wide surveys of PPB have occurred since 1840. In 1995/1996 the Commonwealth Scientific and Industrial Research Organization (CSIRO) Centre for Research on Introduced Marine Pests (CRIMP) undertook an intensive evaluation of the region with the aims of developing a comprehensive species list of native and introduced biota and contrasting previous bay-wide assessments with a current field survey in order to detect new incursions and discern alterations to native communities. Two methods were used to meet these aims: a re-evaluation of regional museum collections and published research in PPB to identify and determine the timing of introductions; and field surveys for benthic (infauna, epifauna and encrusting) organisms between September 1995 to March 1996. One hundred and sixty introduced (99) and cryptogenic (61) species were identified representing over 13% of the recorded species of PPB. As expected, the majority of these are concentrated around the shipping ports of Geelong and Melbourne. Invasions within PPB appear to be increasing, possibly due to an increase in modern shipping traffic and an increase in aquaculture (historically associated with incidental introductions); however the records of extensive biological surveys suggest that this may, in part, be an artefact of sampling effort. In contrast to Northern Hemisphere studies, PPB (and Southern Hemisphere introductions in general) have significantly different suites of successfully invading taxa. PPB is presented as one of the most invaded marine ecosystems in the Southern Hemisphere.Communicated by M.S. Johnson, Crawley  相似文献   
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We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990–91 and 1991–92. Pooled liver samples were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), including non-ortho congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Most samples contained detectable concentrations of DDE, PCBs, although there was substantial variability in patterns and trends among neighboring samples. Concentrations of DDE were in some mink and several otter samples from the lower Columbia River elevated (to 4700 g/kg wet weight); excluding one mink sample from the Wenatchee area, mean DDE levels generally decreased between 1978–79 and 1990–92. PCBs were present in all samples. PCB concentrations in otter livers collected from the lower Columbia were ten-fold lower than measured a decade previously; nevertheless, a sample taken near Portland had a mean concentration of 1500 g/kg, within a range of concentrations associated with reproductive effects in captive mink. Concentrations of 2,3,7,8-TCDD and TCDF were generally below detection limits, except for one otter collected near a pulp mill at Castlegar, on the upper Columbia, with 11 ng TCDD/kg in liver. Elevated concentrations of higher chlorinated PCDD/Fs, probably resulting from use of chlorophenolic wood preservatives, were found in both species; one otter sample from the lower Columbia had 2200 ng OCDD/kg. International TCDD toxic equivalent levels in mink (31 ng/kg) and otter (93 ng/kg) from the lower Columbia River approached toxicity thresholds for effects on reproduction in ranch mink.  相似文献   
5.
By applying principles of adaptive management, and by using the valuable information that arthropods provide from assessment and monitoring programs, managers can identify and reduce possible impacts on biodiversity in development projects. In 1996, the Smithsonian Institution's Monitoring and Assessment of Biodiversity program worked together with Shell Prospecting and Development Peru to establish an adaptive management program to protect biodiversity in a natural gas exploration project in a Peruvian rainforest. In this paper, we outlined the conceptual steps involved in establishing an assessment and monitoring program for arthropods, including setting objectives, evaluating the results and making decisions. We also present the results of the assessment using some of groups of arthropods, and summarize the steps taken to identify appropriate groups for monitoring.  相似文献   
6.
Simple mathematical models are developed to account for the rather slow mass transport of nonaqueous phase liquid (NAPL) into aqueous solution in groundwater during flushing operations. The models are based on the assumption that this bottleneck in the process is associated with diffusion in the aqueous phase in the porous medium from the location of the NAPL drops/ganglia in a region of relatively low permeability out into a region of substantially higher permeability, somewhat analogous to diffusion from a block of porous rock into a nearby fracture, where the fracture system overwhelmingly dominates the overall permeability. The models include batch flushing, flushing in a laboratory column, and a one-dimensional model for flushing by means of a single recovery well.  相似文献   
7.
Molecular methods, including DNA probes, were used to identify and enumerate pathogenic Vibrio species in the Chesapeake Bay; our data indicated that Vibrio vulnificus exhibits seasonal fluctuations in number. Our work included a characterization of total microbial communities from the Bay; development of microarrays that identify and quantify the diversity of those communities; and observation of temporal changes in those communities. To identify members of the microbial community, we amplified the 16S rDNA gene from community DNA isolated from a biofilm sample collected from the Chesapeake Bay in February, 2000. The resultant 75 sequences were 95% or more similar to 7 species including two recently described Shewanella species, baltica and frigidimarina, that have not been previously isolated from the Chesapeake. When the genera of bacteria from biofilm after culturing are compared to those detected by subcloning amplified 16S fragments from community DNA, the cultured sample exhibited a strong bias. In oysters collected in February, the most common bacteria were previously unknown. Based on our 16S findings, we are developing microarrays to detect these and other microbial species in these estuarine communities. The microarrays will detect each species using four distinct loci, with the multiple loci serving as an internal control. The accuracy of the microarray will be measured using sentinel species such as Aeromonas species, Escherichia coli, and Vibrio vulnificus. Using microarrays, it should be possible to determine the annual fluctuations of bacterial species (culturable and non-culturable, pathogenic and non-pathogenic). The data may be applied to understanding patterns of environmental change; assessing the health of the Bay; and evaluating the risk of human illness associated with exposure to and ingestion of water and shellfish.  相似文献   
8.
The partial differential equations governing the migration of adsorbable pollutants undergoing 2-dimensional flow in saturated aquifers are presented. The analytical solution of these equations is rarely possible, and the use of mesh or grid techniques for numerical integration leads to so-called numerical dispersion, excessive dispersion which is an artifact associated with the numerical method. We discuss here the use of conformal mapping techniques to develop coordinate systems in which numerical dispersion transverse to the direction of flow is eliminated. Some simple illustrations are presented.  相似文献   
9.
Recent lichen surveys in the foreland of The Syterb?cken glacier reveal that the crustose lichens, principally species of Rhizocarpon section Rhizocarpon, exhibit marginal bleaching, readily distinguishable from normal pigmented forms. The largest elliptical thallus of Rhizocarpon measured 290 mm maximum diameter on a bedrock outcrop beyond the margin of Little Ice Age moraines in the upper Syterb?cken Valley. Many small and large thalli of Rhizocarpon suffered damage to the periphery of individual thalli. We examine here some of the possible hypotheses explaining these occurrences. Among others, these are bedrock lithology, ice crystal blasting, long-term snowbank cover, ultraviolet exposure and acid rain. While at this time none of the possibilities can be ruled out entirely, acid rain would appear to be at least one of the factors involved. Acid rain, which is known to produce a soil pH as low as 3.3 in the field area, appears to provide a high input of H(+) ions that the lichen algal component cannot withstand. However, the lack of similar effects on associated foliose or fruticose forms raises the possibility that perhaps two or more factors specific to the environment of Rhizocarpon are operating.  相似文献   
10.
A pleural effusion associated with congenital pulmonary lymphangiectasia was detected in a fetus in utero but was absent at the time of delivery. The pleural effusion was unilateral although the disease involved both lungs. In this case there was an association between polyhydramnios and congenital pulmonary lymphangiectasia.  相似文献   
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