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41.
David L. MacIntosh James H. Stewart Theodore A. Myatt Joseph E. Sabato George C. Flowers Kirk W. Brown Dennis J. Hlinka David A. Sullivan 《Atmospheric environment (Oxford, England : 1994)》2010,44(2):262-270
CALPUFF is an atmospheric source-receptor model recommended by the U.S. Environmental Protection Agency for use on a case-by-case basis in complex terrain and wind conditions. The ability of the model to provide useful information for exposure assessments in areas with those topographical and meteorological conditions has received little attention. This is an important knowledge gap for use of CALPUFF outside of regulatory applications, such as exposure analyses conducted in support of risk assessments and health studies. We compared deposition of cadmium (Cd), lead (Pb), and zinc (Zn) calculated with CALPUFF as a result of emissions from a zinc smelter with corresponding concentrations of the metals measured in attic dust and soil samples obtained from the surrounding area. On a point-by-point analysis, predictions from CALPUFF explained 11% (lead) to 53% (zinc) of the variability in concentrations measured in attic dust. Levels of heavy metals in soil interpolated to 100 residential addresses from the distribution of concentrations measured in soil samples also agreed well with deposition predicted with CALPUFF: R2 of 0.46, 0.76, and 079 for Pb, Cd, and Zn, respectively. Community-average concentrations of Cd, Pb, and Zn measured in soil were significantly (p < 0.0001) and strongly correlated (R2 ranged from 0.77 to 0.98) with predicted deposition rates. These findings demonstrate that CALPUFF can provide reasonably accurate predictions of the patterns of long-term air pollutant deposition in the near-field associated with emissions from a discrete source in complex terrain. Because deposition estimates are calculated as a linear function of air concentrations, CALPUFF is expected to be reliable model for prediction of long-term average, near-field ambient air concentrations in complex terrain as well. 相似文献
42.
For many citizens and policymakers, the empirical relationship between economic growth and biodiversity conservation has not been sufficiently established for purposes of identifying the types of economic policies amenable to biodiversity conservation. Some think economic growth conflicts with biodiversity conservation; others think economic growth conduces biodiversity conservation. With panel data from 1997‐2011, encompassing US continental states, we developed a series of statistical models to investigate the relationships among species endangerment, human population, and economic growth as indicated by GDP and per capita GDP. Species endangerment is highly correlated with population and GDP, and per capita GDP is a significant regressor of species endangerment. Across US continental states, competitive exclusion of non‐human species occurs via human economic growth and population growth. 相似文献
43.
Kapheim KM Bernal SP Smith AR Nonacs P Wcislo WT 《Behavioral ecology and sociobiology》2011,65(6):1179-1190
Developmental maternal effects are a potentially important source of phenotypic variation, but they can be difficult to distinguish
from other environmental factors. This is an important distinction within the context of social evolution, because if variation
in offspring helping behavior is due to maternal manipulation, social selection may act on maternal phenotypes, as well as
those of offspring. Factors correlated with social castes have been linked to variation in developmental nutrition, which
might provide opportunity for females to manipulate the social behavior of their offspring. Megalopta genalis is a mass-provisioning facultatively eusocial sweat bee for which production of males and females in social and solitary
nests is concurrent and asynchronous. Female offspring may become either gynes (reproductive dispersers) or workers (non-reproductive
helpers). We predicted that if maternal manipulation plays a role in M. genalis caste determination, investment in daughters should vary more than for sons. The mass and protein content of pollen stores
provided to female offspring varied significantly more than those of males, but volume and sugar content did not. Sugar content
varied more among female eggs in social nests than in solitary nests. Provisions were larger, with higher nutrient content,
for female eggs and in social nests. Adult females and males show different patterns of allometry, and their investment ratio
ranged from 1.23 to 1.69. Adult body weight varied more for females than males, possibly reflecting increased variation in
maternal investment in female offspring. These differences are consistent with a role for maternal manipulation in the social
plasticity observed in M. genalis. 相似文献
44.
The challenges currently facing resource managers are large-scale and complex, and demand new approaches to balance development and conservation goals. One approach that shows considerable promise for addressing these challenges is adaptive management, which by now is broadly seen as a natural, intuitive, and potentially effective way to address decision-making in the face of uncertainties. Yet the concept of adaptive management continues to evolve, and its record of success remains limited. In this article, we present an operational framework for adaptive decision-making, and describe the challenges and opportunities in applying it to real-world problems. We discuss the key elements required for adaptive decision-making, and their integration into an iterative process that highlights and distinguishes technical and social learning. We illustrate the elements and processes of the framework with some successful on-the-ground examples of natural resource management. Finally, we address some of the difficulties in applying learning-based management, and finish with a discussion of future directions and strategic challenges. 相似文献
45.
Hariz Islas-Flores Leobardo Manuel Gómez-Oliván Marcela Galar-Martínez Sandra García-Medina Nadia Neri-Cruz Octavio Dublán-García 《Environmental science and pollution research international》2014,21(7):5157-5166
Although trace concentrations of ibuprofen (IBP) have been detected in diverse water bodies, there is currently insufficient information on the potentially deleterious effects of this xenobiotic. The present study aimed to determine whether IBP induces oxidative stress in brain, liver, gill, and blood of the common carp Cyprinus carpio. To this end, the median lethal concentration at 96 h (96-h LC50) was determined and the lowest observed adverse effect level was established. Carp were exposed to the latter concentration (17.6 mg L?1) for 12, 24, 48, 72, and 96 h, and the following biomarkers were evaluated: lipid peroxidation (LPX) and activity of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase. Results indicated that LPX and antioxidant enzymes’ activity increased significantly (p?<?0.05) with respect to the control group in liver, gill, and blood, while no significant differences occurred in brain. In conclusion, IBP induced oxidative stress on C. carpio, the liver being the organ most affected by this damage. 相似文献
46.
W.J.F. Standring J.E. Brown M. Dowdall E.M. Korobova V.G. Linnik A.G. Volosov 《Journal of environmental radioactivity》2009,100(12):1109
The Mining and Chemical Industrial Combine, Zheleznogorsk (MCIC, previously known as Krasnoyarsk-26) on the River Yenisey has contaminated the surrounding environment with anthropogenic radionuclides as a result of discharges of radioactive wastes. The purpose of this study was to investigate the vertical distribution of anthropogenic contamination (137Cs and plutonium) within floodplain areas at different distances from the discharge point. Sites were chosen that display different characteristics with respect to periodic inundation with river water. Cs-137 activity concentrations were in the range 23–3770 Bq/kg (dry weight, d.w.); Pu-239,240 activity concentrations were in the range <0.01–14.2 Bq/kg (d.w.). Numerous sample cores exhibited sub-surface maxima which may be related to the historical discharges from the MCIC. Possible evidence indicating the deposition of earlier discharges at MCIC in deeper core layers was observed in the 238Pu:239,240Pu activity ratio data: a Pu signal discernible from global fallout could be observed in numerous samples. Cs-137 and Pu-239,240 activity concentrations were correlated with the silt fraction (% by mass <63 μm) though no significant correlation was observed between (grain-size) normalised 137Cs activity concentrations and distance downstream from the MCIC. 相似文献
47.
48.
Association of plutonium with sediments from the Ob and Yenisey Rivers and Estuaries 总被引:1,自引:0,他引:1
Lindis Skipperud Justin Brown L. Keith Fifield Deborah H. Oughton Brit Salbu 《Journal of environmental radioactivity》2009
The present study applied sequential extraction techniques to investigate the binding and mobility of plutonium (Pu) in sediments from the rivers and estuaries of the Ob and Yenisey. As a study site, the Ob and Yenisey are particularly interesting as both rivers have weapons-grade Pu sources in their catchment areas, including the Russian Pu production and reprocessing plants at Mayak, Tomsk-7 and Krashnoyarsk, and the Semipalantinsk nuclear weapons testing site in Kazakhstan. Plutonium activity and 240Pu/239Pu ratios were determined using accelerator mass spectrometry (AMS). Sequential extractions showed that between 47 and 80% of the Pu in Yenisey River sediments and 35–53% of the Pu in soils around the Techa River are mobilized with weak oxidising agents, which can indicate that Pu is bound to organic material. In contrast, Pu in Ob and Yenisey Estuarine sediments was more strongly bound, with 60–100% being found in the HNO3-extractable fraction. This change in speciation could reflect either that Pu bound to organic material in the Techa and Yenisey River sediments becomes more fixed to the sediments with time, or that organic-bound Pu is mobilized and released to the water when the sediments encounter the more saline water of the Ob and Yenisey estuaries. In general, 240Pu/239Pu ratios were relatively consistent between different extraction fractions, although, in whole sediments, an increase in ratio was observed with distance from the source. This reflects the increased influence of weapon fallout from catchment runoff within the river systems, as compared to the weapons-grade sources close to the production and reprocessing plants. Knowledge of Pu speciation in the Ob and Yenisey Rivers, and the processes controlling its behaviour in estuarine systems, can improve predictions of its transfer and subsequent environmental impact to Arctic Seas. 相似文献
49.
Ian R. Waite Jonathan G. Kennen Jason T. May Larry R. Brown Thomas F. Cuffney Kimberly A. Jones James L. Orlando 《Journal of the American Water Resources Association》2012,48(3):570-583
Waite, Ian R., Jonathan G. Kennen, Jason T. May, Larry R. Brown, Thomas F. Cuffney, Kimberly A. Jones, and James L. Orlando, 2012. Comparison of Stream Invertebrate Response Models for Bioassessment Metrics. Journal of the American Water Resources Association (JAWRA) 48(3): 570-583. DOI: 10.1111/j.1752-1688.2011.00632.x Abstract: We aggregated invertebrate data from various sources to assemble data for modeling in two ecoregions in Oregon and one in California. Our goal was to compare the performance of models developed using multiple linear regression (MLR) techniques with models developed using three relatively new techniques: classification and regression trees (CART), random forest (RF), and boosted regression trees (BRT). We used tolerance of taxa based on richness (RICHTOL) and ratio of observed to expected taxa (O/E) as response variables and land use/land cover as explanatory variables. Responses were generally linear; therefore, there was little improvement to the MLR models when compared to models using CART and RF. In general, the four modeling techniques (MLR, CART, RF, and BRT) consistently selected the same primary explanatory variables for each region. However, results from the BRT models showed significant improvement over the MLR models for each region; increases in R2 from 0.09 to 0.20. The O/E metric that was derived from models specifically calibrated for Oregon consistently had lower R2 values than RICHTOL for the two regions tested. Modeled O/E R2 values were between 0.06 and 0.10 lower for each of the four modeling methods applied in the Willamette Valley and were between 0.19 and 0.36 points lower for the Blue Mountains. As a result, BRT models may indeed represent a good alternative to MLR for modeling species distribution relative to environmental variables. 相似文献
50.
Moe MK Huber S Svenson J Hagenaars A Pabon M Trümper M Berger U Knapen D Herzke D 《Chemosphere》2012,89(7):869-875
For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by 1H, 13C and 19F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility. 相似文献