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241.
A synthesis of research on the responses of terrestrial biota (1095 effect sizes) to industrial pollution (206 point emission sources) was conducted to reveal regional and global patterns from small-scale observational studies. A meta-analysis, in combination with other statistical methods, showed that the effects of pollution depend on characteristics of the specific polluter (type, amount of emission, duration of impact on biota), the affected organism (trophic group, life history), the level at which the response was measured (organism, population, community), and the environment (biome, climate). In spite of high heterogeneity in responses, we have detected several general patterns. We suggest that the development of evolutionary adaptations to pollution is a common phenomenon and that the harmful effects of pollution on terrestrial ecosystems are likely to increase as the climate warms. We argue that community- and ecosystem-level responses to pollution should be explored directly, rather than deduced from organism-level studies.  相似文献   
242.

Purpose

The aim of this study is to develop a normalization method for real-time PCR data by analyzing the most stably expressed control genes in mussel (Mytilus edulis) reproductive tissue.

Methods

To facilitate this, six candidate genes, including several commonly used in the literature, were investigated in mussels at different stages of gametogenesis and following experimental exposure to a model estrogen (17b-estradiol). GeNorm and NormFinder softwares were employed to assess the stability of the reference genes.

Results

Our results demonstrate that the most stable reference genes are not the same in mussels at different stages of gametogenesis and in experimentally E2-exposed mussels. Interestingly, HEL (helicase) and ACT (actin) mRNA expression levels were most affected by the stage of gametogenesis and yet, in molluscan studies, ACT is possibly the most frequently used reference gene.

Conclusions

We demonstrate that the experimental results are highly dependent on the reference gene chosen and that statistically significant contrasting differences between sample groups are present or absent depending on the reference gene employed.  相似文献   
243.
We present an investigation on how economic and environmental assessment results change when different process options or evaluation settings are considered. As the main case study the production technology of methyl methacrylate (MMA) is investigated. Six commercial processes using different reaction routes are modelled and evaluated with respect to their economic and environmental performance. On these six base case models different process options and evaluation settings are considered and the resulting impacts on the assessment results are quantified. Major findings of the study are that the more decision-variables become fixed, the smaller becomes the impact of the decisions still to be taken—but not only with respect to the economic performance but also with regard to the environmental assessment result. Along the process development steps the potential impacts on the economic and environmental performance decrease to the same degree. The results obtained for the evaluation settings do not show such a systematic pattern as those for the process options. This finding indicates that decision makers face many options in the economic and especially the environmental assessment of chemical processes which might lead to quite different magnitudes in variability due to either the choice of method or the choice of method parameters. This paper demonstrates that the resulting variability might be crucial with respect to the decision making outcome.  相似文献   
244.
Ozone and urban forests in Italy   总被引:2,自引:0,他引:2  
Ozone levels along urban-to-rural gradients in three Italian cities (Milan, Florence, Bari) showed that average AOT40 values at rural and suburban sites were 2.6 times higher than those determined at urban sites. However, O3 also exceeded the European criteria to protect forest health at urban sites, even when the standards for human health protection were met. For protecting street trees in Mediterranean cities, the objectives of measurement at urban sites should extend from the protection of human health to the protection of vegetation as well. A review of forest effects on O3 pollution and of O3 pollution on forest conditions in Italian cities showed that it was not possible to distinguish the effect of O3 in the complex mixture of urban pollutants and stressors. A preliminary list of tree species for urban planning in the Mediterranean area shows the average tree capacity of O3 removal and VOC emission.  相似文献   
245.

Purpose

This study presents a procedure to differentiate the local and remote sources of particulate-bound polycyclic aromatic hydrocarbons (PAHs).

Methods

Data were collected during an extended PM2.5 sampling campaign (2009?C2010) carried out for 1?year in Venice-Mestre, Italy, at three stations with different emissive scenarios: urban, industrial, and semirural background. Diagnostic ratios and factor analysis were initially applied to point out the most probable sources. In a second step, the areal distribution of the identified sources was studied by applying the discriminant analysis on factor scores. Third, samples collected in days with similar atmospheric circulation patterns were grouped using a cluster analysis on wind data. Local contributions to PM2.5 and PAHs were then assessed by interpreting cluster results with chemical data.

Results

Results evidenced that significantly lower levels of PM2.5 and PAHs were found when faster winds changed air masses, whereas in presence of scarce ventilation, locally emitted pollutants were trapped and concentrations increased. This way, an estimation of pollutant loads due to local sources can be derived from data collected in days with similar wind patterns. Long-range contributions were detected by a cluster analysis on the air mass back-trajectories. Results revealed that PM2.5 concentrations were relatively high when air masses had passed over the Po Valley. However, external sources do not significantly contribute to the PAHs load.

Conclusions

The proposed procedure can be applied to other environments with minor modifications, and the obtained information can be useful to design local and national air pollution control strategies.  相似文献   
246.
Volunteered geographic information and social networking in a WebGIS has the potential to increase public participation in soil and water conservation, promote environmental awareness and change, and provide timely data that may be otherwise unavailable to policymakers in soil and water conservation management. The objectives of this study were: (1) to develop a framework for combining current technologies, computing advances, data sources, and social media; and (2) develop and test an online web mapping interface. The mapping interface integrates Microsoft Silverlight, Bing Maps, ArcGIS Server, Google Picasa Web Albums Data API, RSS, Google Analytics, and Facebook to create a rich user experience. The website allows the public to upload photos and attributes of their own subdivisions or sites they have identified and explore other submissions. The website was made available to the public in early February 2011 at and evaluated for its potential long-term success in a pilot study.  相似文献   
247.
The aims of this study were (a) to evaluate the degradation of acetamiprid with the use of Fenton reaction, (b) to investigate the effect of different concentrations of H2O2 and Fe2+, initial pH and various iron salts, on the degradation of acetamiprid and (c) to apply response surface methodology for the evaluation of degradation kinetics.  相似文献   
248.
ABSTRACT

Land use data are among the inputs used to determine dry deposition velocities for photochemical grid models such as the Comprehensive Air Quality Model with extensions (CAMx) that is currently used for attainment demonstrations and air quality planning by the state of Texas. The sensitivity of dry deposition and O3 mixing ratios to land use classification was investigated by comparing predictions based on default U.S. Geological Survey (USGS) land use data to predictions based on recently compiled land use data that were collected to improve biogenic emissions estimates. Dry deposition of O3 decreased throughout much of eastern Texas, especially in urban areas, with the new land use data. Predicted 1-hr averaged O3 mixing ratios with the new land use data were as much as 11 ppbv greater and 6 ppbv less than predictions based on USGS land use data during the late afternoon. In addition, the area with peak O3 mixing ratios in excess of 100 ppbv increased significantly in urban areas when deposition velocities were calculated based on the new land use data. Finally, more detailed data on land use within urban areas resulted in peak changes in O3 mixing ratios of ~2 ppbv. These results indicate the importance of establishing accurate, internally consistent land use data for photochemical modeling in urban areas in Texas. They also indicate the need for field validation of deposition rates in areas experiencing changing land use patterns, such as during urban reforestation programs or residential and commercial development.  相似文献   
249.
Abstract

Different autonomous communities located in northern Spain have large populations of dairy cattle. In the case of Asturias, the greatest concentration of dairy farms is found in the areas near the coast, where the elimination of cattle manure by means of its use as a fertilizer may lead to environmental problems. The aim of the present research work was to study the anaerobic treatment of the liquid fraction of cattle manure at mesophilic temperature using an upflow anaerobic sludge blanket (UASB) reactor combined with a settler after a pasteurization process at 70 °C for 2 hr. The manure used in this study came from two different farms, with 40 and 200 cows, respectively. The manure from the smaller farm was pretreated in the laboratory by filtration through a 1-mm mesh, and the manure from the other farm was pretreated on the farm by filtration through a separator screw press (0.5-mm mesh). The pasteurization process removed the pathogenic microorganisms lacking spores, such as Enterococcus, Yersinia, Pseudomonas, and coliforms, but bacterial spores are only reduced by this treatment, not removed. The combination of a UASB reactor and a settler proved to be effective for the treatment of cattle manure. In spite of the variation in the organic loading rate and total solids in the influent during the experiment, the chemical oxygen demand (COD) of the effluent from the settler remained relatively constant, obtaining reductions in the COD of ~85%.  相似文献   
250.
The levels of selected polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in human milk samples from the areas of Venice and Rome, primarily in order to characterize the current levels of infant exposure to PCBs and PBDEs due to breast feeding in Italy. Sixteen non-dioxin-like PCBs, including the traditional indicator congeners, and 11 PBDEs, comprising the relevant PBDE-47, PBDE-99, and PBDE-153, were determined. Congeners were selected for analysis according to their relative abundance in human tissues, toxicological relevance, and diffusion in the environment. Dietary habits of the milk donors were recorded by questionnaires; mothers of the Venice area were classified into three groups according to their consumption of local fish, molluscs, and other fishery products. Sigma(16)(PCBs) and Sigma(11)(PBDEs) (ng g(-1) fat) for the areas of Venice and Rome were respectively, 250-390 and 240, and 1.6-2.8 and 4.1. An increase of fish and fishery product consumption could not be associated with an increase of PCB and PBDE levels in milk.  相似文献   
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