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101.
Site characterization is an essential initial step in determining the feasibility of remedial alternatives at hazardous waste sites. Physicochemical and mineralogical characterization of U-contaminated soils in deeply weathered saprolite at Area 2 of the DOE Field Research Center (FRC) site, Oak Ridge, TN, was accomplished to examine the feasibility of bioremediation. Concentrations of U in soil-saprolite (up to 291 mg kg(-1) in oxalate-extractable U(o)) were closely related to low pH (ca. 4-5), high effective cation exchange capacity without Ca (64.7-83.2 cmol(c) kg(-1)), amorphous Mn content (up to 9910 mg kg(-1)), and the decreased presence of relative clay mineral contents in the bulk samples (i.e., illite 2.5-12 wt. %, average 32 wt. %). The pH of the fill material ranged from 7.0 to 10.5, whereas the pH of the saprolite ranged from 4.5 to 8. Uranium concentration was highest (about 300 mg kg(-1)) at around 6 m below land surface near the saprolite-fill interface. The pH of ground water at Area 2 tended to be between 6 and 7 with U concentrations of about 0.9 to 1.7 mg L(-1). These site specific characteristics of Area 2, which has lower U and nitrate contamination levels and more neutral ground water pH compared with FRC Areas 1 and 3 (ca. 5.5 and <4, respectively), indicate that with appropriate addition of electron donors and nutrients bioremediation of U by metal reducing microorganisms may be possible.  相似文献   
102.
The ecosystem services concept is used to make explicit the diverse benefits ecosystems provide to people, with the goal of improving assessment and, ultimately, decision-making. Alongside material benefits such as natural resources (e.g., clean water, timber), this concept includes—through the ‘cultural’ category of ecosystem services—diverse non-material benefits that people obtain through interactions with ecosystems (e.g., spiritual inspiration, cultural identity, recreation). Despite the longstanding focus of ecosystem services research on measurement, most cultural ecosystem services have defined measurement and inclusion alongside other more ‘material’ services. This gap in measurement of cultural ecosystem services is a product of several perceived problems, some of which are not real problems and some of which can be mitigated or even solved without undue difficulty. Because of the fractured nature of the literature, these problems continue to plague the discussion of cultural services. In this paper we discuss several such problems, which although they have been addressed singly, have not been brought together in a single discussion. There is a need for a single, accessible treatment of the importance and feasibility of integrating cultural ecosystem services alongside others.  相似文献   
103.
Methodology for the accounting, generation, and composition of building-related construction and demolition (C&D) at a regional level was explored. Six specific categories of debris were examined: residential construction, nonresidential construction, residential demolition, nonresidential demolition, residential renovation, and nonresidential renovation. Debris produced from each activity was calculated as the product of the total area of activity and waste generated per unit area of activity. Similarly, composition was estimated as the product of the total area of activity and the amount of each waste component generated per unit area. The area of activity was calculated using statistical data, and individual site studies were used to assess the average amount of waste generated per unit area. The application of the methodology was illustrated using Florida, US approximately 3,750,000 metric tons of building-related C&D debris were estimated as generated in Florida in 2000. Of that amount, concrete represented 56%, wood 13%, drywall 11%, miscellaneous debris 8%, asphalt roofing materials 7%, metal 3%, cardboard 1%, and plastic 1%. This model differs from others because it accommodates regional construction styles and available data. The resulting generation amount per capita is less than the US estimate - attributable to the high construction, low demolition activity seen in Florida.  相似文献   
104.
Regional Environmental Change - Small Island Developing States (SIDS) are widely recognised as being very vulnerable to the impacts of climate change. In some manner, climate change will impact on...  相似文献   
105.
Congenital nephrosis of the Finnish type (CNF) is rare outside Finland, where the incidence may be as high as 1 in 2000 live births. Neonates with the disorder develop renal failure within the first months of life and without renal transplantation, the prognosis is extremely poor. This case report describes a woman's three pregnancies, two of which were affected with CNF.  相似文献   
106.
The surf clam, Spisula solidissima (Dillwyn), population in the estuarine waters of Long Island Sound, New York, USA, was characterized in 1984 and again in 1988 by an age structure restricted to just two age-classes, and an apparent lifespan of only about 10 yr. In the inshore coastal waters off Fire Island, New York, a wide age range from 2 to 22 yr old was present. The age structure at Long Beach, New York, a third geographic region which is coastal but influenced by the Hudson River estuary, was similar to Long Island Sound. Juvenile surf clams grew at similar rates in all three geographic regions. However, adults from the Long Island Sound population grew significantly slower and reached an asymptotic maximum size which was 37% smaller than Fire Island adults. Long Beach adults had intermediate growth rates and maximum sizes. The shells of Long Island Sound clams were also 25% thinner than those from the other two regions. Density dependent effects on growth, evaluated over abundances ranging from 0.5 to 294 ind. m–2, were present but were too small to account for observed regional differences. Results suggest that adult surf clams may be physiologically stressed by the reduced salinity and more extreme temperatures found in estuarine waters.  相似文献   
107.
Coexisting species within a guild have the potential for resource overlap and consequently for interspecific competition (e.g., interspecific territoriality). When the adults are of different sizes, which frequently is the case in terrestrial salamander communities in eastern North America, competition may occur between juveniles of the larger species and adults of the smaller species. Adults of the relatively small redbacked salamander (Plethodon einereus: up to 13 cm total length) defend intra- and intersexual territories on the forest floor, and they are broadly sympatric with the larger P. glutinosus (up to 21 cm total length). Although individuals of the two species share the same forest floor habitat, we found significantly fewer juveniles of P. glutinosus sharing territories with 336 same-size adults of P. cinereus than would be expected by random chance alone. In laboratory experiments, residential adults of P. cinereus were as aggressive toward juvenile intruders of P. glutinosus as they were toward adult conspecific intruders. Therefore, adults of P. cinereus appear to defend territories against juveniles of P. glutinosus, illustrating how interference competition may depend on the symmetry of sizes between the species.  相似文献   
108.
We report a case of maternal uniparental disomy of chromosome 10 discovered after chorionic villus sampling (CVS). Direct preparations revealed mosaic trisomy 10, while cultured CVS cells, as well as amniotic fluid cells, showed only a normal 46,XY complement. DNA analysis using microsatellite markers showed both chromosomes 10 to have been inherited from the mother. The pregnancy was complicated by polyhydramnios. A phenotypically normal male infant of appropriate size was delivered by Caesarean section at 41 weeks' gestation. Since only the direct preparations showed trisomy 10, this case illustrates the importance of CVS direct preparations in the detection of pregnancies at risk of uniparental disomy (UPD). Although the increased frequency of confined placental mosaicism (CPM) diagnosed when direct preparations are performed has been viewed negatively, identification of both CPM and UPD may have biological and clinical significance for a pregnancy. Even though only a single case of maternal disomy 10 is reported here, the apparently normal phenotype provides evidence that there are no major imprinted loci on chromosome 10 that affect in utero growth and development. However, other potential effects such as mental retardation will require long-term follow-up of this as well as additional cases.  相似文献   
109.
The presence of infectious protozoan pathogens in reclaimed water may present an unacceptable health risk. This study was designed similar to a study reported by Garcia et al. (2002), which detected no infectious Giardia cysts in the final effluent of a tertiary treatment facility as determined by animal infectivity (dose 1000 cysts/gerbil). This study also included evaluation of Cryptosporidium oocyst infectivity. Infectious Giardia cysts were detected in the final effluent with 1 gerbil out of 3 inoculated with 250 cysts from reclaimed water showing signs of infection 15 days postinoculation. None of the Cryptosporidium oocysts concentrated from the reclaimed water samples appeared to be infectious.  相似文献   
110.
The 2017 revisions to the Regional Haze Rule clarify that visibility progress at Class I national parks and wilderness areas should be tracked on days with the highest anthropogenic contributions to haze (impairment). We compare the natural and anthropogenic contributions to haze in the western United States in 2011 estimated using the Environmental Protection Agency (EPA) recommended method and using model projections from the Comprehensive Air Quality Model with Extensions (CAMx) and the Particulate Source Apportionment Tool (PSAT). We do so because these two methods will be used by states to demonstrate visibility progress by 2028. If the two methods assume different natural and anthropogenic contributions, the projected benefits of reducing U.S. anthropogenic emissions will differ. The EPA method assumes that episodic elevated carbonaceous aerosols greater than an annual 95th percentile threshold are natural events. For western U.S. IMPROVE monitoring sites reviewed in this paper, CAMx-PSAT confirms these episodes are impacted by carbon from wildfire or prescribed fire events. The EPA method assumes that most of the ammonium sulfate is anthropogenic in origin. At most western sites CAMx-PSAT apportions more of the ammonium sulfate on the most impaired days to global boundary conditions and anthropogenic Canadian, Mexican, and offshore shipping emissions than to U.S. anthropogenic sources. For ammonium nitrate and coarse mass, CAMx-PSAT apportions greater contributions to U.S. anthropogenic sources than the EPA method assigns to total anthropogenic contributions. We conclude that for western IMPROVE sites, the EPA method is effective in selecting days that are likely to be impacted by anthropogenic emissions and that CAMx-PSAT is an effective approach to estimate U.S. source contributions. Improved inventories, particularly international and natural emissions, and further evaluation of global and regional model performance and PSAT attribution methods are recommended to increase confidence in modeled source characterization.

Implications: The western states intend to use the CAMx model to project visibility progress by 2028. Modeled visibility response to changes in U.S. anthropogenic emissions may be less than estimated using the EPA assumptions based on total U.S. and international anthropogenic contributions to visibility impairment. Additional model improvements are needed to better account for contributions to haze from natural and international emissions in current and future modeling years. These improvements will allow more direct comparison of model and EPA estimates of natural and anthropogenic contributions to haze and future visibility progress.  相似文献   

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