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131.
Concentrations of total suspended particulate matter, particulate matter with aerodynamic diameter <2.5 μm (PM2.5), particulate matter <10 μm (PM10), and fallout dust were measured at the Iranian Gol-E-Gohar Mining and Industrial Facility. Samples were characterized in terms of mineralogy, morphology, and oxidative potential. Results show that indoor samples exceeded the 24-h PM2.5 and PM10 mass concentration limits (35 and 150 µg m?3, respectively) set by the US National Ambient Air Quality Standards. Calcite, magnetite, tremolite, pyrite, talc, and clay minerals such as kaolinite, vermiculite, and illite are the major phases of the iron ore PM. Accessory minerals are quartz, dolomite, hematite, actinolite, biotite, albite, nimite, laumontite, diopside, and muscovite. The scanning electron microscope structure of fibrous-elongated minerals revealed individual fibers in the range of 1.5 nm to 71.65 µm in length and 0.2 nm to 3.7 µm in diameter. The presence of minerals related to respiratory diseases, such as talc, crystalline silica, and needle-shaped minerals like amphibole asbestos (tremolite and actinolite), strongly suggests the need for detailed health-based studies in the region. The particulate samples show low to medium oxidative potential per unit of mass, in relation to an urban road side control, being more reactive with ascorbate than with glutathione or urate. However, the PM oxidative potential per volume of air is exceptionally high, confirming that the workers are exposed to a considerable oxidative environment. PM released by iron ore mining and processing activities should be considered a potential health risk to the mine workers and nearby employees, and strategies to combat the issue are suggested.  相似文献   
132.
Benthic habitats are known to influence the abundance and richness of demersal fish assemblages; however, little is known about how habitat structure and composition influences these distributions at very fine scales. We examined how the benthic environment structures marine fish assemblages using high-resolution bathymetry and accurate predicted benthic habitat maps. Areas characterised by a mosaic of habitat patches supported the highest richness of demersal fishes. A total of 37.4% of the variation in the distribution of the fish assemblage was attributed to 6 significant variables. Depth explained 23.0% of the variation, with the boulders explaining 12.6% and relief 1.4%. The remaining measures (seawhips, light/exposure and solid reef) provided a small (<1.0%) but significant contribution. Identifying components of the benthic environment important in structuring fish assemblages and understanding how they influence the spatial distribution of marine fishes is imperative for better management of demersal fish populations.  相似文献   
133.
Ocean acidification is one of the key threats facing coral reef ecosystems, but there are few estimates of spatial and temporal variability in pH among reef habitats. The present study documents levels of spatial variability in pH among coral reef habitats (9 to 10), among locations separated by 100’s km of latitude and between east (Great Barrier Reef, GBR) and west (Ningaloo Reef) coasts of Australia. Differences were found in pH between inshore and offshore waters along Ningaloo Reef (means 8.45, 8.53, respectively). Replicate assessments here ranged from 8.22 to 8.64. On the GBR, the range of values over all habitats and replicates was 0.39 pH units (7.98 to 8.37). There were minor but significant differences of 0.05 pH units between 5 consecutive days for habitats on average. Highest pH was recorded in filamentous algal beds maintained by the damselfish Dischistodus perspicillatus. Lowest pH was found in water extracted from sand-dwelling goby holes. While there were marked changes in pH over a 48-h sampling period among 4 habitats at Lizard Island (GBR), there was little evidence of a diel trend. Understanding how pH varies at scales that are relevant to organisms that live on shallow coral reefs is crucial for the design and interpretation of experiments that test the effects on organisms of the changes in water chemistry predicted to affect oceans in the future.  相似文献   
134.
Moore BD  Lawler IR  Wallis IR  Beale CM  Foley WJ 《Ecology》2010,91(11):3165-3176
Ecologists trying to understand the value of habitat to animals must first describe the value of resources contained in the habitat to animals and, second, they must describe spatial variation in resource quality at a resolution relevant to individual animal foraging. We addressed these issues in a study of koalas (Phascolarctos cinereus) in a Eucalyptus woodland. We measured beneficial and deterrent chemical characteristics as well as the palatability of trees using a near-infrared spectroscopic model based on direct feeding experiments. Tree use by koalas was influenced by tree size and foliar quality but was also context-dependent: trees were more likely to be visited if they were surrounded by small, unpalatable trees or by large, palatable trees. Spatial autocorrelation analysis and several mapping approaches demonstrated that foliar quality is spatially structured in the woodland at a scale relevant to foraging decisions by koalas and that the spatial structure is an important component of habitat quality.  相似文献   
135.
Chemical communication is crucial for the organization of social insect colonies. However, with the heavy use of one communication modality, problems may arise such as the interference of different types of information. This study investigated how information about fertility and colony membership is integrated in the ant Camponotus floridanus. We introduced into mature, queenright colonies (a) the nestmate queen, (b) a nestmate worker, (c) a foreign, high-fertility queen, (d) a foreign, low-fertility queen, and (e) a foreign worker. As expected, workers did not attack their nestmate queen or a nestmate worker but responded aggressively to foreign workers and foreign, low-fertility queens. Surprisingly, workers did not attack foreign, high-fertility queens. Chemical analysis demonstrated that the cuticular hydrocarbon profile of C. floridanus encodes information about fertility status in queens and workers and colony membership in workers. We suggest that ants respond to this information in the cuticular hydrocarbon profile: individuals with strong fertility signals are accepted regardless of their colony membership, but individuals without strong fertility signals are tolerated only if their cuticular hydrocarbon profile matches that of colony members. Learning how social insects respond to multiple types of information presented together is critical to our understanding of the recognition systems that permit the complex organization of social insect colonies.  相似文献   
136.
Experts can provide valuable information to fill knowledge gaps in published research on management effectiveness, particularly for threatened ecosystems, for which there is often limited evidence and the need for prompt intervention to ensure their persistence. One such ecosystem, alpine peatland, is threatened by climate change and other pressures, provides vital ecosystem services, and supports unique biodiversity. In a workshop, we gathered and synthesized into an accessible format information from experts on interventions used, threat context, and intervention effectiveness for Australian alpine peatland and used this knowledge to evaluate local relevance of the global literature for this threatened ecosystem. Experts identified 15 interventions used to conserve Australian peatlands, most of which enhanced or restored peatland condition and effectively addressed diverse threats. Experts’ perspectives and global studies were strongly aligned, suggesting that research on peatland management may be broadly relevant across contexts, despite the distinct characteristics of Australian systems. Our workshop-based expert elicitation approach provided insights into current management practices unavailable in the literature.  相似文献   
137.
In 1986, the Federal Technology Transfer Act (FTTA) was established to promote a closer, collaborative relationship between federal government agencies and the private sector. With the increasing need for new cost-effective technologies to prevent and control pollution, both the U.S. Environmental Protection Agency and private industry are encouraged to facilitate the transfer of knowledge and technology under this Act. The FTTA removed several of the legal and institutional barriers to cooperative research that existed before the Act's passage. Through the FTTA, the government strives to promote the movement of its products, processes, skills and knowledge into the private sector for further development and commercialization by encouraging the exchange of technical personnel and the sharing of facilities and other resources. Collaborative efforts among industry, federal agencies and academia are made possible through cooperative research and development agreements (CRDAs). Thirty-three CRDAs and four licensing agreements have been initiated with EPA under the program. This paper provides an overview of this new and innovative program.  相似文献   
138.
139.
Point velocity measurements conducted by traversing a Pitot tube across the cross section of a flow conduit continue to be the standard practice for evaluating the accuracy of continuous flow-monitoring devices. Such velocity traverses were conducted in the exhaust duct of a reduced-scale analog of a stationary source, and mean flow velocity was computed using several common integration techniques. Sources of random and systematic measurement uncertainty were identified and applied in the uncertainty analysis. When applicable, the minimum requirements of the standard test methods were used to estimate measurement uncertainty due to random sources. Estimates of the systematic measurement uncertainty due to discretized measurements of the asymmetric flow field were determined by simulating point velocity traverse measurements in a flow distribution generated using computational fluid dynamics. For the evaluated flow system, estimates of relative expanded uncertainty for the mean flow velocity ranged from ±1.4% to ±9.3% and depended on the number of measurement locations and the method of integration.
Implications:Accurate flow measurements in smokestacks are critical for quantifying the levels of greenhouse gas emissions from fossil-fuel-burning power plants, the largest emitters of carbon dioxide. A systematic uncertainty analysis is necessary to evaluate the accuracy of these measurements. This study demonstrates such an analysis and its application to identify specific measurement components and procedures needing focused attention to improve the accuracy of mean flow velocity measurements in smokestacks.  相似文献   
140.
Organic sewage pollution is the major stressor that affects benthic communities in the coastal waters. In the present study involving a once-off sampling (July–August 2003) of a sewage treatment plant (STP) outfall and areas 6 km farther into the sea, we tried to estimate the severity of organic pollution on marine macrobenthos over a pollution gradient in the inshore waters (station depths, 5–30 m) off a heavily urbanized tropical city, on the east coast of India. Multivariate ordination analyses revealed two different groups of faunal assemblages. Group I is associated with sites impacted by the sewage outfall and group II with the locations 3–6 km away in the open sea. Polychaetes and amphipods were the predominant fauna with significant taxonomic differences between the assemblages. Despite the homogeneity in sediment texture, the two-fold increase in sediment organic matter near the sewage outfall area supported r-strategists, while group II locations favoured K-strategists. Approximation through benthic opportunistic polychaetes amphipods (BOPA) index and information on the key taxa responsible for the observed assemblage patterns corroborated these findings. Thus, the present findings revealed how organic sewage pollution influences benthic diversity in coastal waters by supporting communities of opportunistic characteristics. We advocate inclusion of community traits and compatible analytical tools (statistical approaches) in studies of similar nature so that the observations could be compared and broad remedial measures could be evolved.  相似文献   
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