32 research outputs found

    Breeding Biology of Oryzomys Palustris, the Marsh Rice Rat, in Eastern Virginia

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    The objectives of our study were to determine the age of maturity, litter size, and the timing of the breeding season of marsh rice rats (Oryzomys palustris) of coastal Virginia. From May 1995 to May 1996, monthly samples of rice rats were live-trapped in two coastal tidal marshes of eastern Virginia, and then necropsied. Sexual maturity was attained at 30-40 g for both sexes. Mean litter size of 4.63 (N= 16) did not differ among months or in mass or parity classes. Data from two other studies conducted in the same county, one of them contemporaneous, also were examined. Based on necropsy, rice rats bred from March to October; breeding did not occur in December-February. By contrast, rice rats observed during monthly trapping on nearby live-trap grids were judged, using external indicators, to be breeding year-round except January. Compared to internal examinations, external indicators of reproductive condition were not reliable for either sex in predicting breeding status in the marsh rice rat

    Standardized data quality acceptance criteria for a rapid Escherichia coli qPCR method (Draft Method C) for water quality monitoring at recreational beaches

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    There is growing interest in the application of rapid quantitative polymerase chain reaction (qPCR) and other PCR-based methods for recreational water quality monitoring and management programs. This interest has strengthened given the publication of U.S. Environmental Protection Agency (EPA)-validated qPCR methods for enterococci fecal indicator bacteria (FIB) and has extended to similar methods for Escherichia coli (E. coli) FIB. Implementation of qPCR-based methods in monitoring programs can be facilitated by confidence in the quality of the data produced by these methods. Data quality can be determined through the establishment of a series of specifications that should reflect good laboratory practice. Ideally, these specifications will also account for the typical variability of data coming from multiple users of the method. This study developed proposed standardized data quality acceptance criteria that were established for important calibration model parameters and/or controls from a new qPCR method for E. coli (EPA Draft Method C) based upon data that was generated by 21 laboratories. Each laboratory followed a standardized protocol utilizing the same prescribed reagents and reference and control materials. After removal of outliers, statistical modeling based on a hierarchical Bayesian method was used to establish metrics for assay standard curve slope, intercept and lower limit of quantification that included between-laboratory, replicate testing within laboratory, and random error variability. A nested analysis of variance (ANOVA) was used to establish metrics for calibrator/positive control, negative control, and replicate sample analysis data. These data acceptance criteria should help those who may evaluate the technical quality of future findings from the method, as well as those who might use the method in the future. Furthermore, these benchmarks and the approaches described for determining them may be helpful to method users seeking to establish comparable laboratory-specific criteria if changes in the reference and/or control materials must be made

    Evaluation of multiple laboratory performance and variability in analysis of recreational freshwaters by a rapid Escherichia coli qPCR method (Draft Method C)

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    There is interest in the application of rapid quantitative polymerase chain reaction (qPCR) methods for recreational freshwater quality monitoring of the fecal indicator bacteria Escherichia coli (E. coli). In this study we determined the performance of 21 laboratories in meeting proposed, standardized data quality acceptance (QA) criteria and the variability of target gene copy estimates from these laboratories in analyses of 18 shared surface water samples by a draft qPCR method developed by the U.S. Environmental Protection Agency (EPA) for E. coli. The participating laboratories ranged from academic and government laboratories with more extensive qPCR experience to “new” water quality and public health laboratories with relatively little previous experience in most cases. Failures to meet QA criteria for the method were observed in 24% of the total 376 test sample analyses. Of these failures, 39% came from two of the “new” laboratories. Likely factors contributing to QA failures included deviations in recommended procedures for the storage and preparation of reference and control materials. A master standard curve calibration model was also found to give lower overall variability in log10 target gene copy estimates than the delta-delta Ct (ΔΔCt) calibration model used in previous EPA qPCR methods. However, differences between the mean estimates from the two models were not significant and variability between laboratories was the greatest contributor to overall method variability in either case. Study findings demonstrate the technical feasibility of multiple laboratories implementing this or other qPCR water quality monitoring methods with similar data quality acceptance criteria but suggest that additional practice and/or assistance may be valuable, even for some more generally experienced qPCR laboratories. Special attention should be placed on providing and following explicit guidance on the preparation, storage and handling of reference and control materials

    Technological Review of Permeable Pavement Systems for Applications in Small Island Developing States

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    © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim This paper presents a technological review of permeable pavement systems (PPS) for applications in urban areas of small island developing states (SIDS). This review includes a literature survey of PPS, challenges and opportunities of climate change and urban development in SIDS, and key aspects worth considering for widespread acceptance and use of PPS in SIDS. SIDS is comprised of several nations located across the Atlantic, Pacific, and Indian Oceans, as well as the Caribbean, Mediterranean, and South China seas. They are particularly susceptible to the effects of climate change and increasing urbanization. Urban stormwater management and flooding are often serious challenges faced by authorities in most SIDS. PPS are resilient infrastructure which can assist in mitigating flooding by reducing runoff and peak flows and improving the landscape perviousness. PPS can further improve stormwater runoff quality to receiving natural waters by reducing pollutant loadings of suspended solids, heavy metals, and hydrocarbons. Unlike most territorial states, the geographical and geologically confined nature of most SIDS present unique parameters for consideration when designing permeable pavements for SIDS. This literature survey found that some of the most important parameters include traffic loads, cost, construction aggregate choice, and availability, permeability of existing soil at the intended location, depth of water table, potential for groundwater contamination, slope of the pavement, stormwater reuse option, clogging, maintenance, and support from policy makers. Continued practical research into the use of permeable pavements for urban runoff management in SIDS is on-going with the expectation of PPS being utilized in many SIDS

    The sources, impact and management of car park runoff pollution: a review

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    Traffic emissions contribute significantly to the build-up of diffuse pollution loads on urban surfaces with their subsequent mobilisation and direct discharge posing problems for receiving water quality. This review focuses on the impact and mitigation of solids, metals, nutrients and organic pollutants in the runoff deriving from car parks. Variabilities in the discharged pollutant levels and in the potentials for pollutant mitigation complicate an impact assessment of car park runoff. The different available stormwater best management practices and proprietary devices are reported to be capable of reductions of between 20% and almost 100% for both suspended solids and a range of metals. This review contributes to prioritising the treatment options which can achieve the appropriate pollutant reductions whilst conforming to the site requirements of a typical car park. By applying different treatment scenarios to the runoff from a hypothetical car park, it is shown that optimal performance, in terms of ecological benefits for the receiving water, can be achieved using a treatment train incorporating permeable paving and bioretention systems. The review identifies existing research gaps and emphasises the pertinent management practices as well as design issues which are relevant to the mitigation of car park pollution

    Public participation in the development and implementation of the Etowah Habitat Conservation Plan

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    Proceedings of the 2003 Georgia Water Resources Conference, held April 23-24, 2003, at the University of Georgia.The Etowah River is one of the most diverse river systems in the United States with 91 native fish species and numerous species of mussels known from the system. The Etowah River lies in the northern edge of the Atlanta metropolitan area, and therefore is in an area of intense development. Currently there are 15 species listed as federally or state threatened, endangered, or likely candidates (9 fishes, 5 mussels, and one aquatic insect). An interdisciplinary team of scientists, lawyers, educators and policy analysts has begun the process of developing a Habitat Conservation Plan (HCP) for the Etowah watershed, by involving both local government representatives and public stakeholders. Research on many HCPs around the United States has shown that public participation in the development of a Habitat Conservation Plan is one of the most important aspects in the outcome of the plan. The role of the Etowah River as a resource to those who live in the watershed makes public input particularly significant in the development of an HCP. The goals of those initiating the public participation component of the Etowah HCP are twofold: 1) In the short-term we wish to educate stakeholders and interested parties on background information in order to solicit involvement in the process and to effectively and appropriately incorporate the input into the Etowah HCP; 2) In the long term we wish to increase awareness and stewardship across the Etowah watershed

    Cryptosporidium and Giardia in Surface Water: A Case Study from Michigan, USA to Inform Management of Rural Water Systems

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    Cryptosporidium and Giardia pose a threat to human health in rural environments where water supplies are commonly untreated and susceptible to contamination from agricultural animal waste/manure, animal wastewater, septic tank effluents and septage. Our goals for this paper are to: (1) explore the prevalence of these protozoan parasites, where they are found, in what quantities, and which genotypes are present; (2) examine relationships between disease and land use comparing human health risks between rural and urban environments; and (3) synthesize available information to gain a better understanding of risk and risk management for rural water supplies. Our results indicate that Cryptosporidium and Giardia were more prevalent in rural versus urban environments based on the number of positive samples. Genotyping showed that both the human and animal types of the parasites are found in rural and urban environments. Rural areas had a higher incidence of disease compared to urban areas based on the total number of disease cases. Cryptosporidiosis and giardiasis were both positively correlated (p < 0.001) with urban area, population size, and population density. Finally, a comprehensive strategy that creates knowledge pathways for data sharing among multiple levels of management may improve decision-making for protecting rural water supplies

    Grand challenges for research in the Laurentian Great Lakes

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    The Laurentian Great Lakes (LGL) constitute one of the largest freshwater systems in the world while providing social and economic value to two powerful nations. The spatial scale of these inland seas falls between two endpoints: small lakes and oceans. Lacustrine in many characteristics, the LGL often require a scientific approach with attributes similar to those of oceanography. There is a strong sense that within the LGL support for scientific research has not kept pace with the need for process-oriented research and that we lack basic information needed to forecast change, mitigate impacts and restore and preserve the LGL. Consequently, 58 researchers met in September 2014 and identified five “Grand Challenges for Research in the LGL”: (1) How has this vast inland freshwater system responded to shifting climate in the past, and how will it respond in the future? (2) What is the current status of the most important ecosystem processes, including their variability in space and time? (3) What processes are characteristic only of large lakes, and how do the distinct habitats integrate into a whole? (4) What are the ecosystem responses to major anthropogenic forces such as nutrients and invasive species, and are these reversible? and (5) What are the small to large-scale linkages and feedbacks among societal decisions, biological systems, and physicochemical dynamics? An urgent need exists for a unified scientific voice that articulates the Grand Challenges for research in the LGL and the need for associated funding. This treatise describing the Grand Challenges develops that voice
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