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61.
The objectives of this research are to assess the greenhouse gas mitigation potential of carbon policies applied to the ruminant livestock sector [inclusive of the major ruminant species—cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), and goats (Capra hircus)]—with particular emphasis on understanding the adjustment challenges posed by such policies. We show that market-based mitigation policies can greatly amplify the mitigation potential identified in marginal abatement cost studies by harnessing powerful market forces such as product substitution and trade. We estimate that a carbon tax of US$20 per metric ton of carbon dioxide (CO2) equivalent emissions could mitigate 626 metric megatons of CO2 equivalent ruminant emissions per year (MtCO2-eq year?1). This policy would also incentivize a restructuring of cattle production, increasing the share of cattle meat coming from the multiproduct dairy sector compared to more emission intensive, single purpose beef sector. The mitigation potential from this simple policy represents an upper bound because it causes ruminant-based food production to fall and is therefore likely to be politically unpopular. In the spirit of the Paris Agreement (UNFCCC 2015), which expresses the ambition of reducing agricultural emissions while protecting food production, we assess a carbon policy that applies both a carbon tax and a subsidy to producers to manage the tradeoff between food production and mitigation. The policy maintains ruminant production and consumption levels in all regions, but for a much lower global emission reduction of 185 MtCO2-eq year?1. This research provides policymakers with a quantitative basis for designing policies that attempt to trade off mitigation effectiveness with producer and consumer welfare.  相似文献   
62.
The effects of pipeline construction and reclamation techniques on the restoration of rough fescue plant communities following pipeline construction in southwestern Alberta, Canada were evaluated after 7–40 years. The pipeline construction right-of-way (ROW) sites varied from no recovery of rough fescue grassland to moderate recovery. The ROW sites had a higher proportion of introduced grasses and forbs, less topsoil, and poorer rangeland health than the adjacent undisturbed grassland. Within the ROW sites, less topsoil was present on those with larger diameter pipe and which had topsoil fully stripped from the ROW during construction. Introduced grasses, Festuca ovina (sheep fescue) and Poa compressa (Canada bluegrass), succeeded in establishment following seeding and persisted for at least 40 years. Poa pratensis (Kentucky bluegrass) dominated many of the ROW sites. Contributing factors to moderate recovery of rough fescue grassland were related to post-growing season pipeline construction, ideally, between August and March, summer or fall seeding, and minimum disturbance trench-only stripping. Reclamation practices appeared more important than time since restoration in the restoration of rough fescue grassland.  相似文献   
63.
Coagulation followed by floc separation is a key process for the removal of algal organic matter(AOM) in water treatment. Besides optimizing coagulation parameters,knowledge of the properties of AOM-flocs is essential to maximizing AOM removal.However, the impact of AOM on the floc properties remains unclear. This study investigated how peptides/proteins derived from the cellular organic matter(COM) of the cyanobacterium Microcystis aeruginosa influenced the size, structure, and shape of flocs formed at different shear rates(G). Flocs formed by kaolinite, COM-peptides/proteins and a mixture of the same were studied, and the effect of intermolecular interactions between floc components on floc properties was assessed. The coagulation experiments were performed in a Taylor–Couette reactor, with aluminum(Al) or ferric sulphate(Fe) utilized as coagulants. Image analysis was performed to gauge floc size and obtain data on fractal dimension. It was found that floc properties were affected by the presence of the COM-peptides/proteins and the coagulant used. COM-peptides/proteins increased floc size and porosity and widened floc size distributions. The Fe coagulant produced larger and less compact flocs than Al coagulant. Moreover, the decrease in floc size that occurred in parallel with increase in shear rate was not smooth in progress. A rapid change for the kaolinite-coagulant suspension and two rapid changes for the suspensions containing COM were observed. These were attributed to various intermolecular interactions between floc components participating in coagulation at different G. Based on the results obtained, shear rates suitable for efficient separation of flocs containing COM were suggested.  相似文献   
64.
Understanding the influence of maternal exposures on gestational age and birth weight is essential given that pre-term and/or low birth weight infants are at risk for increased mortality and morbidity. We performed a retrospective analysis of a cohort exposed to polybrominated biphenyls (PBB) through accidental contamination of cattle feed and polychlorinated biphenyls (PCB) through residual contamination in the geographic region. Our study population consisted of 444 mothers and their 899 infants born between 1975 and 1997. Using restricted maximum likelihood estimation, no significant association was found between estimated maternal serum PBB at conception or enrollment PCB levels and gestational age or infant birth weight in unadjusted models or in models that adjusted for maternal age, smoking, parity, infant gender, and decade of birth. For enrollment maternal serum PBB, no association was observed for gestational age. However, a negative association with high levels of enrollment maternal serum PBB and birth weight was suggested. We also examined the birth weight and gestational age among offspring of women with the highest (10%) PBB or PCB exposure, and observed no significant association. Because brominated compounds are currently used in consumer products and therefore, are increasingly prevalent in the environment, additional research is needed to better understand the potential relationship between in utero exposure to brominated compounds and adverse health outcomes.  相似文献   
65.
Coral reefs provide shoreline protection, biological diversity, fishery harvests, and tourism, all values that stem from the physically-complex coral infrastructure. Stony corals (scleractinians) construct and maintain the reef through deposition of calcium carbonate. Therefore, assessment of coral reefs requires at least some measurement endpoints that reflect the biological and physical condition of stony corals. Most monitoring programs portray coral quantity as live coral cover, which is the two-dimensional proportion of coral surface to sea floor viewed from above (planar view). The absence of the third dimension, however, limits our ability to characterize coral reef value, physiology, health and sustainability. A three-dimensional (3D) approach more realistically characterizes coral structure available as community habitat and, when combined with estimates of live coral tissue, quantifies the amount of living coral available for photosynthesis, growth and reproduction. A rapid coral survey procedure that coupled 3D coral quantification with more traditional survey measurements was developed and tested in the field. The survey procedure relied on only three underwater observations – species identification, colony size, and proportion of live tissue – made on each colony in the transect. These observations generated a variety of metrics, including several based on 3D colony surface area, that are relevant to reef management.  相似文献   
66.
The purpose of this paper is to describe instrumentation to aerodynamically size suspended particulates found in ambient air and to summarize results of field testing utilizing the new technique.

A four-stage, multiorifice high-volume fractionating impactor with backup filter, which can be operated as a component of the standard high-volume sampler, collects particulate matter in five separate aerodynamic size ranges: 7 micrometer (μm) or larger, 3.3 to 7 μm, 2.0 to 3.3 μm, 1.1 to 2.0 μm, and 0.01 to 1.1 μm.

Comparative field tests utilizing duplicate sampling techniques were conducted to determine the feasibility of using the size fractionator on a routine basis in field operations. Verification of the actual particle size separation was not undertaken; however, earlier tests utilizing laboratory-generated aerosols have been performed with satisfactory results.

The results of field tests indicate that the fractionator can be used to determine the aerodynamic size distribution of particulate matter. A glass fiber surface with a pH of 11.0 was found to adsorb atmospheric acid gases during sampling and thus gave erroneous mass concentration results when compared to the standard high-volume sampler. Glass fiber filters with a pH of 6.5 eliminated the acid gas adsorption.  相似文献   
67.
The objectives of the study are to present a critical review of the 238U, 234U, 235U, 226Ra and 210Pb levels in water samples from the EPA studies (U.S. EPA in Abandoned uranium mines and the Navajo Nation: Red Valley chapter screening assessment report. Region 9 Superfund Program, San Francisco, 2004, Abandoned uranium mines and the Navajo Nation: Northern aum region screening assessment report. Region 9 Superfund Program, San Francisco, 2006, Health and environmental impacts of uranium contamination, 5-year plan. Region 9 Superfund Program, San Franciso, 2008) and the dose assessment for the population due to ingestion of water containing 238U and 234U. The water quality data were taken from Sect. “Data analysis” of the published report, titled Abandoned Uranium Mines Project Arizona, New Mexico, Utah–Navajo Lands 1994–2000, Project Atlas. Total uranium concentration was above the maximum concentration level for drinking water (7.410–1 Bq/L) in 19 % of the water samples, while 238U and 234U concentrations were above in 14 and 17 % of the water samples, respectively. 226Ra and 210Pb concentrations in water samples were in the range of 3.7 × 10?1 to 5.55 × 102 Bq/L and 1.11 to 4.33 × 102 Bq/L, respectively. For only two samples, the 226Ra concentrations exceeded the MCL for total Ra for drinking water (0.185 Bq/L). However, the 210Pb/226Ra ratios varied from 0.11 to 47.00, and ratios above 1.00 were observed in 71 % of the samples. Secular equilibrium of the natural uranium series was not observed in the data record for most of the water samples. Moreover, the 235U/totalU mass ratios ranged from 0.06 to 5.9 %, and the natural mass ratio of 235U to totalU (0.72 %) was observed in only 16 % of the water samples, ratios above or below the natural ratio could not be explained based on data reported by U.S. EPA. In addition, statistical evaluations showed no correlations among the distribution of the radionuclide concentrations in the majority of the water samples, indicating more than one source of contamination could contribute to the sampled sources. The effective doses due to ingestion of the minimum uranium concentrations in water samples exceed the average dose considering inhalation and ingestion of regular diet for other populations around the world (1 μSv/year). The maximum doses due to ingestion of 238U or 234U were above the international limit for effective dose for members of the public (1 mSv/year), except for inhabitants of two chapters. The highest effective dose was estimated for inhabitants of Cove, and it was almost 20 times the international limit for members of the public. These results indicate that ingestion of water from some of the sampled sources poses health risks.  相似文献   
68.
The exact contribution of corporate social responsibility (CSR) to a company as well as to its stakeholders should be measurable in order to be evaluated correctly. The difficult task of measuring the results of CSR has been a matter of significant research both by academics and by practitioners. Some of the literature on corporate social responsibility combines CSR with stakeholder theory introducing corporate social performance. The literature has attempted to describe emerging models of the issues that lead to a coherent model of what would represent corporate social performance. However, it is the case that social aspects are “soft” in nature, therefore being difficult to quantify. Innovated methods of performance measurement such as that of Balanced Scorecard has lately been introduced in some companies in their attempt to include non-financial indicators to give a more balanced and forecasting power to the traditional financial performance assessment system, but the view of corporate social responsibility is rarely taken into account. Furthermore, management frameworks that try to cover social and environmental aspects, such as Global Reporting Initiative, by providing a number of related performance measures, are not able to connect them with corporate strategy and are poor evaluators of cause–effect relationships. In the present paper, a CSR performance measurement framework based on the adoption of the Balanced Scorecard approach is presented. For the development of the proposed framework, the existing assessment of CSR and Corporate Sustainability actions of the Greek companies of different sectors was analysed in order to identify common practices in CSR performance evaluation as well as existing limitations. Taking into account the social indicators suggested by the traditional balanced scorecard views, an extension of its structure is proposed in order to better embody the environmental and social aspects of company performance.  相似文献   
69.
70.
On January 13, 1999 a consent decree was signed for the first community settlement ever successfully negotiated for a Superfund site. The 10-square mile groundwater study zone in Rockford, Illinois, is only 20 percent of the area of the city, but represents 60 percent of its industrial capacity. Local government and business leaders took the initiative to negotiate a community-based settlement with the United States Environmental Protection Agency (EPA) and the Illinois Environmental Protection Agency (IEPA) and find financing mechanisms that citizens could back. Rockford dodged the Superfund bullet that has ripped apart so many other communities as bank loans dry up, development ceases, local taxes plunge along with property values, the local economy stagnates, and neighbor is pitted against neighbor in a litigation war.  相似文献   
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