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61.
The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) did not ignore the fifty individual states when establishing responsibility, authority, and liability for cleaning up hazardous waste sites. Although CERCLA gives EPA the ultimate authority to select a remedy for a contaminated site, the law was drafted not only to allow for state activity without EPA, but also for significant state input when EPA is involved. The relationship between a state (and its environmental laws) and EPA can help decide the remedial and financial interests of any potentially responsible party (PRP). This article discusses the relevant CERCLA provisions, recent court decisions, and resolved and unresolved issues in federal-state Superfund involvement, and recommends several common-sense strategies for PRPs when working with a state in a Superfund cleanup.  相似文献   
62.
The workplace has become the locus of many stress management and stress reduction interventions. However, little attention has focused on how worksite factors affect the implementation and impact of such interventions. In this paper, we investigate the effect of new versus traditional industrial relations practices on the impact of a worksite stress reduction program in a manufacturing setting. More specifically, a participatory action research (PAR) stress project is described and evaluated in two different labor–management relations contexts. One organization is characterized by the emerging ’new‘ industrial relations system where labor–management relations incorporate elements of joint problem-solving. The other organization has a more traditional approach where labor–management relations are formally adversarial. Results indicate that the labor–management relations context did influence the impact of the stress project. Involvement in the PAR stress project enhanced employee participation in decision-making in both contexts. However, involvement in the stress project enhanced employees' perceptions of the climate for participation only in the organization with more cooperative industrial relations. Increases in coworker support and decreases in depressive symptoms were associated with involvement in the PAR stress project in the organization with more adversarial industrial relations.  相似文献   
63.
Indian mustard [Brassica juncea (L.) Czern.] transgenics overexpressing ATP sulfurylase (APS plants) were shown previously to have higher levels of total thiols, S, and Se. The present study explores the effect of ATP sulfurylase overexpression on tolerance and accumulation of other metals, both oxyanions and cations, reasoning that some anions may react directly with ATP sulfurylase, while other ions may be bound by its thiol end products. The APS transgenics were compared with wild-type plants with respect to tolerance and accumulation of As, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, V, W, and Zn, supplied individually in agar medium (seedlings) or in hydroponics (mature plants). At the seedling stage, APS transgenics were more tolerant than wild type to As(III), As(V), Cd, Cu, Hg, and Zn, but less tolerant to Mo and V. The APS seedlings had up to 2.5-fold higher shoot concentrations of As(III), As(V), Hg, Mo, Pb, and V, and somewhat lower Cr levels. Mature APS plants contained up to 2.5-fold higher shoot concentrations of Cd, Cr, Cu, Mo, V, and W than wild type. They also contained 1.5- to 2-fold higher levels of the essential elements Fe, Mo, and S in most of the treatments. Mature APS plants showed no differences in metal tolerance compared with the wild type. Overexpression of ATP sulfurylase may be a promising approach to create plants with enhanced phytoextraction capacity for mixtures of metals.  相似文献   
64.
Using Science to Assess Environmental Vulnerabilities   总被引:5,自引:0,他引:5  
Beginning in 1995, the U.S. Environmental Protection Agency (U.S. EPA), Office of Research and Development has focused much of its ecological research in the Mid-Atlantic as part of the Mid-Atlantic Integrated Assessment (MAIA). The goal of MAIA is to improve the assessability of scientific information in environmental decision-making. Following the Environmental Monitoring and Assessment Program (EMAP) whose goal is to guide monitoring that effectively reflects current ecosystem condition and trends, MAIA's second, current, phase of research under the Regional Vulnerability Assessment (ReVA) program is designed to target risk management activities using available data and models. The papers presented here are from a conference held in May 2003 that presented results of research in this second phase of MAIA. The conference was organized into the following topics: 1. Assessing Current Impacts and Vulnerabilities 2. Forecasting Environmental Condition and Vulnerabilities 3. Developing Management Strategies to Optimize the Future, and 4. Assessing and Responding to Environmental Vulnerability.  相似文献   
65.
Because environmental conservation can remove scarce natural resources from competing uses, it is important to gain support for conservation programs by demonstrating that management actions have been effective in achieving their goals. One way to do this is to show that selected significant environmental variables (indicators) vary between managed and unmanaged areas or change over time following implementation of a management regime. However, identifying indicators that reflect environmental conditions relevant to management practices has proven difficult. This paper focuses on developing a framework for choosing indicators in a coral reef habitat. The framework consisted of three phases: (1) information gathering to identify candidate variables; (2) field-testing candidate variables at sites that differ in intensity of human activity, thus identifying potential indicators; and (3) evaluating potential indicators against a set of feasibility criteria to identify the most useful indicators. To identify indicators suitable to measure the success of a management strategy to reduce anchor damage to a coral reef, 24 candidate variables were identified and evaluated at sites with different intensities of anchoring. In this study, measures that reflected injuries to coral colonies were generally more efficient than traditional measures of coral cover in describing the effects of anchoring. The number of overturned colonies was identified as the single most useful indicator of coral reef condition associated with anchoring intensities. The indicator selection framework developed here has the advantages of being transparent, cost efficient, and readily transferable to other types of human activities and management strategies.  相似文献   
66.
Few disputes in the annals of US environmentalism enjoy the pedigree of the conservation-preservation debate. Yet, although many scholars have written extensively on the meaning and history of conservation and preservation in American environmental thought and practice, the resonance of these concepts outside the academic literature has not been sufficiently examined. Given the significance of the ideals of conservation and preservation in the justification of environmental policy and management, however, we believe that a more detailed analysis of the real-world use and understanding of these ideas is needed. In this paper, we describe the results of a qualitative, semantic study of the concepts of conservation and preservation undertaken in the context of the Chattahoochee National Forest (CNF), located in northern Georgia (USA). Thirty in-depth interviews were conducted with scientists and north Georgia residents either interested or involved in the future management of the forest. Respondents were asked to define conservation and preservation in their own words and to indicate which approach they felt was more appropriate for the management of the CNF. Qualitative content analysis was used to elicit a set of recurring themes for each foundational concept. Taken together, these themes help to flesh out the meaning of conservation and preservation for citizens and scientists today, and illustrate the evolving nature of two of the more significant and venerable ideas animating US environmental policy and management.  相似文献   
67.
ABSTRACT: Interbasin water transfer is one of the most controversial water-resources-planning topics. Local communities, particularly those from which the water is to be taken (donor regions), generate enough opposition to doom many projects to failure. The opposition often arises because planners have traditionally considered excess water a free commodity rather than a marketable resource. To make transfer schemes mutually acceptable to donor and recipient regions, visible benefits must be offered. Agreement must be made on an acceptable purchase price and/or on other benefits such as a substantial amount of low flow augmentation or possibly some degree of flood control on the donor source stream. The hydrologic and economic feasibility of water transfer from the East Susquehanna River basin to the Delaware Reservoir System for supplemental supply to the New York City area was investigated. Nine alternative schemes for diversions up to 400 cfs and compensations in the form of low flow augmentation and/or flood control were considered resulting in unit costs to the recipient region between $90 and $380/mg. If only the minimum state-mandated flow is released to the Susquehanna River, the savings to the water recipients would be sufficient to pay a purchase price of about $21/mg, which would be equivalent to a total amount of $420,000/year for an average export of 100 cfs.  相似文献   
68.
This article assesses the possibilities of establishing more efficient patterns of energy use in Haiti, a country increasingly dependent on imported petroleum products to fuel its economy. The author examines the various consuming sectors of the economy and the options for the use of indigenous fuels in place of petroleum. She next describes the potential roles national energy planning and foreign assistance can play in solving the more pressing of Haiti's energy problems. Four functions are urgently needed: collection of basic energy data, co-ordination of alternative energy development, establishment of an energy office in the government and an effort to co-ordinate bilateral and multilateral assistance in the energy field. Cet article évalue les possibilités d'établir des modèles d'utilisation d'énergie plus efficaces en Haïti, pays de plus en plus dépendant des importations de produits pétroliers pour son économie. L'auteur examine les divers secteurs de consommation de l'économie et les choix qui existent en ce qui concerne l'utilisation des combustibles domestiques à la place du pétrole. L'auteur décrit ensuite les rôles potentiels que peuvent jouer la planification nationale de l'énergie et l'assistance extérieure dans la résolution des problèmes énergétiques les plus urgents du pays. Quatre lignes d'action sont requises d'urgence: le rassemblement des données énergétiques de base, la coordination du développement de sources d'énergie de remplacement, la création d'une direction de l'énergie à l'échelon gouvernemental et la mise en oeuvre d'une politique coordonnée d'assistance bilatérale et multilatérale dans le domaine de l'énergie. Este articulo evalúa las posibilidades de establecer estructuras de consumo de energía mas eficientes en Haiti, pais que tiene una dependencia creciente en el petróleo importado. El autor examina varios sectores consumidores de energia y las opciones existentes para sustituir el petróleo por fuentes energéticas nacionales. Luego examina el rol potencial de la planificación energética nacional y la asistencia extranjera en resolver los problemas energéticos más agudos en Haiti. Se establece la necesidad urgente de las siguientes funciones: colección de información básica sobre energía, coordinación del desarrollo energético, establecimiento de una institución que se ocupe de energía en el gobierno y coordinación de la asistencia bilateral y multilateral en el campo de la energía.  相似文献   
69.
ABSTRACT: Several methods for synthetic unit hydrographs are available in the literature. Most of these methods involve the hand fitting of a curve over a set of a few hydrograph points, which can sometimes be a subjective task. Besides, the user often finds it difficult or simply neglects to adjust the generated unit graph to a runoff volume of one unit (inch, cm, or mm). It is the purpose of this paper to present to the design hydrologist a simple method to fit a smooth gamma distribution over a single point specified by the unit hydrograph peak and the time to peak with a guaranteed unit depth of runoff.  相似文献   
70.

Objectives

To develop a flexible droplet digital PCR (ddPCR) workflow to perform non-invasive prenatal diagnosis via relative mutation dosage (RMD) for maternal pathogenic variants with a range of inheritance patterns, and to compare the accuracy of multiple analytical approaches.

Methods

Cell free DNA (cfDNA) was tested from 124 archived maternal plasma samples: 88 cases for sickle cell disease and 36 for rare Mendelian conditions. Three analytical methods were compared: sequential probability ratio testing (SPRT), Bayesian and z-score analyses.

Results

The SPRT, Bayesian and z-score analyses performed similarly well with correct prediction rates of 96%, 97% and 98%, respectively. However, there were high rates of inconclusive results for each cohort, particularly for z-score analysis which was 31% overall. Two samples were incorrectly classified by all three analytical methods; a false negative result predicted for a fetus affected with sickle cell disease and a false positive result predicting the presence of an X-linked IDS variant in an unaffected fetus.

Conclusions

ddPCR can be applied to RMD for diverse conditions and inheritance patterns, but all methods carry a small risk of erroneous results. Further evaluation is required both to reduce the rate of inconclusive results and explore discordant results in more detail.  相似文献   
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