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51.
Scott M. Weir 《Environmental pollution (Barking, Essex : 1987)》2010,158(12):3596-3606
A large data gap for reptile ecotoxicology still persists; therefore, ecological risk assessments of reptiles usually incorporate the use of surrogate species. This necessitates that (1) the surrogate is at least as sensitive as the target taxon and/or (2) exposures to the surrogate are greater than that of the target taxon. We evaluated these assumptions for the use of birds as surrogates for reptiles. Based on a survey of the literature, birds were more sensitive than reptiles in less than 1/4 of the chemicals investigated. Dietary and dermal exposure modeling indicated that exposure to reptiles was relatively high, particularly when the dermal route was considered. We conclude that caution is warranted in the use of avian receptors as surrogates for reptiles in ecological risk assessment and emphasize the need to better understand the magnitude and mechanism of contaminant exposure in reptiles to improve exposure and risk estimation. 相似文献
52.
An assessment of the benthic macroinvertebrate community was conducted to characterize the ecological recovery of a channelized
main stem and two small tributaries at the Watershed Research and Education Center (WREC, Arkansas, USA). Three other headwater
streams in the same basin were also sampled as controls and for biological reference information. A principal components analysis
produced stream groupings along an overall gradient of physical habitat integrity, with degraded reaches showing lower RBP
habitat scores, reduced flow velocities, smaller substrate sizes, greater conductivity, and higher percentages of sand and
silt substrate. The benthic macroinvertebrate assemblage at WREC was dominated by fast-reproducing dipteran larvae (midge
and mosquito larvae) and physid snails, which comprised 71.3% of the total macroinvertebrate abundance over three sampling
periods. Several macroinvertebrate assemblage metrics should provide effective targets for monitoring overall improvements
in the invertebrate assemblage including recovery towards a more complex food web (e.g., total number of taxa, number of EPT
taxa, percent 2 dominant taxa). However, current habitat conditions and the extent of existing degradation, system isolation
and surrounding urban or agricultural land-uses might affect the level of positive change to the system. We therefore suggest
a preliminary restoration strategy involving the addition of pool habitats in the system. At one pool we collected a total
of 29 taxa (dominated by water beetle predators), which was 59% of total number of taxa collected at WREC. Maintaining water-retentive
pools to collect flows and maintain water permanence focuses on enhancing known biology and habitat, thus reducing the effects
of abiotic filters on macroinvertebrate assemblage recovery. Furthermore, biological assessment prior to restoration supports
a strategy primarily focused on improving the existing macroinvertebrate community in the current context of the system, thereby
reducing costs associated with active channel restoration. Monitoring future biological recovery and determining the contribution
of changing assemblages to specific ecological processes would provide a critical underpinning for adaptive management and
ecologically-effective restoration. 相似文献
53.
Research into national innovation systems (NISs) has received extensive academic and policy attention, and is especially relevant
with latecomer countries seeking to innovate in challenging industrial environments. In playing catch up with their early
industrializing counterparts, methods of learning take on increased importance in determining industrial success for latecomers.
The wind turbine technology innovation system is one that is highly dependent on both the extent of the national learning
processes and the strength of the national social-institutional setting. This research investigates the case of Taiwan, a
country which has embarked on a program to build its national innovative capacity in wind turbine technologies with specific
emphasis on Taiwan’s social sector. Within this system, the spotlight will be on four types of learning processes that interplay
during wind turbine development: learning by searching, learning by doing, learning by using, and learning by interacting. Through a case study of the emergence of Taiwan’s burgeoning large-scale wind power technology initiatives, the paper aims
to add to the understanding on how methods of learning impact upon the success of innovation systems. The findings show that
the industry’s future prospects are constrained because of the limited learning by interacting processes between turbine component producers, turbine owners, and researchers and because of weaknesses in the institutional
framework. This research also recognizes the importance that culture has on dominant forms of learning. 相似文献
54.
Crystal Gauvin Emi Uchida Scott Rozelle Jintao Xu Jinyan Zhan 《Environmental management》2010,45(3):488-501
The goal of this article is to understand strategies by which both the environmental and poverty alleviation objectives of
PES programs can be achieved cost effectively. To meet this goal, we first create a conceptual framework to understand the
implications of alternative targeting when policy makers have both environmental and poverty alleviation goals. We then use
the Grain for Green program in China, the largest PES program in the developing world, as a case study. We also use a data set from a survey
that we designed and implemented to evaluate the program. Using the data set we first evaluate what factors determined selection
of program areas for the Grain for Green program. We then demonstrate the heterogeneity of parcels and households and examine the correlations across households and
their parcels in terms of their potential environmental benefits, opportunity costs of participating, and the asset levels
of households as an indicator of poverty. Finally, we compare five alternative targeting criteria and simulate their performance
in terms of cost effectiveness in meeting both the environmental and poverty alleviation goals when given a fixed budget.
Based on our simulations, we find that there is a substantial gain in the cost effectiveness of the program by targeting parcels
based on the “gold standard,” i.e., targeting parcels with low opportunity cost and high environmental benefit managed by
poorer households. 相似文献
55.
Michael J. White Daniel E. Storm Philip Busteed Scott Stoodley Shannon J. Phillips 《Environmental management》2010,45(5):1164-1174
In the United States, many state and federally funded conservation programs are required to quantify the water quality benefits
resulting from their efforts. The objective of this research was to evaluate the impact of conservation practices subsidized
by the Oklahoma Conservation Commission on phosphorus and sediment loads to Lake Wister. Conservation practices designed to
increase vegetative cover in grazed pastures were evaluated using Landsat imagery and the Soil and Water Assessment Tool (SWAT).
Several vegetative indices were derived from Landsat imagery captured before and after the implementation of conservation
practices. Collectively, these indicators provided an estimate of the change in vegetative soil cover attributable to conservation
practices in treated fields. Field characteristics, management, and changes in vegetative cover were used in the SWAT model
to simulate sediment and phosphorus losses before and after practice implementation. Overall, these conservation practices
yielded a 1.9% improvement in vegetative cover and a predicted sediment load reduction of 3.5%. Changes in phosphorus load
ranged from a 1.0% improvement to a 3.5% increase, depending upon initial vegetative conditions. The use of fertilizers containing
phosphorus as a conservation practice in low-productivity pastures was predicted by SWAT to increase net phosphorus losses
despite any improvement in vegetative cover. This combination of vegetative cover analysis and hydrologic simulation was a
useful tool for evaluating the effects of conservation practices at the basin scale and may provide guidance for the selection
of conservation measures subsidized in future conservation programs. 相似文献
56.
Scott M. Payne William W. Woessner 《Journal of the American Water Resources Association》2010,46(5):1003-1023
Payne, Scott M. and William W. Woessner, 2010. An Aquifer Classification System and Geographical Information System-Based Analysis Tool for Watershed Managers in the Western U.S. Journal of the American Water Resources Association (JAWRA) 46(5):1003-1023. DOI: 10.1111/j.1752-1688.2010.00472.x Abstract: Aquifers and groundwater systems can be classified using a variety of independent methods to characterize geologic and hydraulic properties, the degree of connection with surface water, and geochemical conditions. In light of a growing global demand for water, an approach for classifying groundwater systems at the watershed scale is needed. A comprehensive classification system is proposed that combines recognized methods and new approaches. The purpose of classification is to provide groundwater professionals, policy makers, and watershed managers with a widely applicable and repeatable system that reduces sometimes cumbersome complex databases and analyzes to straightforward terminology and graphical representations. The proposed classification system uses basin geology, aquifer productivity, water quality, and the degree of groundwater/surface water connection as classification criteria. The approach is based on literature values, reference databases, and fundamental hydrologic and hydrogeologic principles. The proposed classification system treats dataset completeness as a variable and includes a tiered assessment protocol that depends on the quality and quantity of data. In addition, it assembles and catalogs groundwater information using a consistent set of nomenclature. It is designed to analyze and display results using Geographical Information System mapping tools. 相似文献
57.
Scott Cloutier Lincoln Larson Jenna Jambeck 《Environment, Development and Sustainability》2014,16(3):633-647
In this paper, we assess the associations between self-reported happiness, measured using the Gallup Healthways Well-Being Index (2012), and four US city sustainability indices: the Green City Index (2011), Our Green Cities (2012), Popular Science US City Rankings (2008) and the SustainLane US Green City Rankings (2007). Based on the examination of nonparametric, rank-based correlations, we found positive associations between sustainable development and happiness on all scales and statistically significant correlations for two of the four SD indices. Results support previous research, emphasize the value of explicit consideration of happiness when measuring urban sustainability and highlight the need for future research that assesses the influence of specific subsystems of urban development on self-reported happiness. 相似文献
58.
59.
Karen R. Anderson Edward L. Avol Scott A. Edwards Deborah A. Shamoo Ru-Chuan Peng William S. Linn 《Journal of the Air & Waste Management Association (1995)》2013,63(6):770-776
Respirable carbon or fly ash particles are suspected to increase the respiratory toxicity of coexisting acidic air pollutants, by concentrating acid on their surfaces and so delivering it efficiently to the lower respiratory tract. To investigate this issue, we exposed 15 healthy and 15 asthmatic volunteers in a controlled- environment chamber (21°C, 50 percent relative humidity) to four test atmospheres: (i) clean air; (ii) 0.5-μm H2SO4 aerosol at =100 μg/m3, generated from water solution; (iii) 0,5-μm carbon aerosol at =250 μg/m3, generated from highly pure carbon black with specific surface area comparable to ambient pollution particles; and (iv) carbon as in (iii) plus =100 μg/m3 of ultrafine H2SO4 aerosol generated from fuming sulfuric acid. Electron microscopy showed that nearly all acid in (iv) became attached to carbon particle surfaces, and that most particles remained in the sub-μm size range. Exposures were performed double-blind, 1 week apart. They lasted 1 hr each, with alternate 10-min periods of heavy exercise (ventilation =50 L/min) and rest. Subjects gargled citrus juice before exposure to suppress airway ammonia. Lung function and symptoms were measured pre-exposure, after initial exercise, and at endexposure. Bronchial reactivity to methacholine was measured after exposure. Statistical analyses tested for effects of H2SO4 or carbon, separate or interactive, on health measures. Group data showed no more than small equivocal effects of any exposure on any health measure. One individual's responses were consistent with a clinically significant excess airway constriction from H2SO4 plus carbon, and 2-3 others showed slight excess responses to the combined pollutants, but all these observations might have reflected chance variations. We conclude that coexisting carbon aerosol did not increase respiratory irritancy of H2SO4, in most healthy and asthmatic subjects exposed for 1 hr under simulated "worst-case" ambient conditions. 相似文献
60.
Gregory M. Scott Roseanne D. Diab 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1831-1842
ABSTRACT This paper describes the development and application of an air pollution potential (APP) forecast model based on a synoptic climatological approach in a heavily industrialized area in Durban, South Africa. The aim of the forecasting procedure, based on a system of orange, red, and all-clear alerts, was to give industry advance warning of periods of poor atmospheric dispersion so that it could take action to reduce emissions. The key meteorological parameter in accurately identifying the commencement of an APP episode was found to be negative surface pressure tendency. Wind direction was the most useful parameter in estimating the end point of an APP episode. The model was very successful in identifying periods of elevated SO2, but there is a need for further refinement in forecasting the end point of an episode. 相似文献