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61.
Much of the literature on the consequences of natural disasters has focused on their physical and psychological ramifications. Few researchers have considered how the impacts of a natural disaster can influence academic achievement. This study analyses data collected from nearly 300 students at a mid‐sized, private university in the northeast United States to determine if the effects of Cyclone Sandy in 2012 are associated with measures of academic achievement. The findings reveal that experiencing headaches after the event resulted in a higher likelihood of students suffering a loss of academic motivation. In addition, experiencing headaches and a loss of academic motivation were correlated with a lower grade point average (GPA) during the semester in which Sandy made landfall. However, the more direct effects of the superstorm, including displacement and a loss of power, did not have a significant bearing on academic achievement. Lastly, the paper examines the implications for higher education policy and future research. 相似文献
62.
Daren Harmel Kevin Wagner Emily Martin Doug Smith Pauline Wanjugi Terry Gentry Lucas Gregory Tina Hendon 《Environmental monitoring and assessment》2016,188(3):170
Storm water runoff is increasingly assessed for fecal indicator organisms (e.g., Escherichia coli, E. coli) and its impact on contact recreation. Concurrently, use of autosamplers along with logistic, economic, technical, and personnel barriers is challenging conventional protocols for sample holding times and storage conditions in the field. A common holding time limit for E. coli is 8 h with a 10 °C storage temperature, but several research studies support longer hold time thresholds. The use of autosamplers to collect E. coli water samples has received little field research attention; thus, this study was implemented to compare refrigerated and unrefrigerated autosamplers and evaluate potential E. coli concentration differences due to field storage temperature (storms with holding times ≤24 h) and due to field storage time and temperature (storms >24 h). Data from 85 runoff events on four diverse watersheds showed that field storage times and temperatures had minor effects on mean and median E. coli concentrations. Graphs and error values did, however, indicate a weak tendency for higher concentrations in the refrigerated samplers, but it is unknown to what extent differing die-off and/or regrowth rates, heterogeneity in concentrations within samples, and laboratory analysis uncertainty contributed to the results. The minimal differences in measured E. coli concentrations cast doubt on the need for utilizing the rigid conventional protocols for field holding time and storage temperature. This is not to say that proper quality assurance and quality control is not important but to emphasize the need to consider the balance between data quality and practical constraints related to logistics, funding, travel time, and autosampler use in storm water studies. 相似文献
63.
Tarek Abichou Jeremy Clark Jeffery Chanton Gary Hater Roger Green Doug Goldsmith 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1403-1410
In the method termed “Other Test Method-10,” the U.S. Environmental Protection Agency has proposed a method to quantify emissions from nonpoint sources by the use of vertical radial plume mapping (VRPM) technique. The surface area of the emitting source and the degree to which the different zones of the emitting source are contributing to the VRPM computed emissions are often unknown. The objective of this study was to investigate and present an approach to quantify the unknown emitting surface area that is contributing to VRPM measured emissions. Currently a preexisting model known as the “multiple linear regression model,” which is described in Thoma et al. (2009), is used for quantifying the unknown surface area. The method investigated and presented in this paper utilized tracer tests to collect data and develop a model much like that described in Thoma et al. (2009). However, unlike the study used for development of the multiple linear regression model, this study is considered a very limited study due to the low number of pollutant releases performed (seven total releases). It was found through this limited study that the location of an emitting source impacts VRPM computed emissions exponentially, rather than linearly (i.e., the impact that an emitting source has on VRPM measurements decreases exponentially with increasing distances between the emitting source and the VRPM plane). The data from the field tracer tests were used to suggest a multiple exponential regression model. The findings of this study, however, are based on a very small number of tracer tests. More tracer tests performed during all types of climatic conditions, terrain conditions, and different emissions geometries are still needed to better understand the variation of capture efficiency with emitting source location. This study provides a step toward such an objective.
Implications The findings of this study will aid in the advancement of the VRPM technique. In particular, the contribution of this study is to propose a slight improvement in how the area contributing to flux is determined during VRPM campaigns. This will reduce some of the technique's inherent uncertainties when it is employed to estimate emissions from an area source under nonideal conditions. 相似文献
64.
Reimus PW Callahan TJ Ware SD Haga MJ Counce DA 《Journal of contaminant hydrology》2007,93(1-4):85-95
Diffusion cell experiments were conducted to measure nonsorbing solute matrix diffusion coefficients in forty-seven different volcanic rock matrix samples from eight different locations (with multiple depth intervals represented at several locations) at the Nevada Test Site. The solutes used in the experiments included bromide, iodide, pentafluorobenzoate (PFBA), and tritiated water ((3)HHO). The porosity and saturated permeability of most of the diffusion cell samples were measured to evaluate the correlation of these two variables with tracer matrix diffusion coefficients divided by the free-water diffusion coefficient (D(m)/D*). To investigate the influence of fracture coating minerals on matrix diffusion, ten of the diffusion cells represented paired samples from the same depth interval in which one sample contained a fracture surface with mineral coatings and the other sample consisted of only pure matrix. The log of (D(m)/D*) was found to be positively correlated with both the matrix porosity and the log of matrix permeability. A multiple linear regression analysis indicated that both parameters contributed significantly to the regression at the 95% confidence level. However, the log of the matrix diffusion coefficient was more highly-correlated with the log of matrix permeability than with matrix porosity, which suggests that matrix diffusion coefficients, like matrix permeabilities, have a greater dependence on the interconnectedness of matrix porosity than on the matrix porosity itself. The regression equation for the volcanic rocks was found to provide satisfactory predictions of log(D(m)/D*) for other types of rocks with similar ranges of matrix porosity and permeability as the volcanic rocks, but it did a poorer job predicting log(D(m)/D*) for rocks with lower porosities and/or permeabilities. The presence of mineral coatings on fracture walls did not appear to have a significant effect on matrix diffusion in the ten paired diffusion cell experiments. 相似文献
65.
66.
Michael Mitchell Michael Lockwood Susan A. Moore Sarah Clement 《Journal of Environmental Planning and Management》2015,58(11):1903-1922
Addressing environmental problems requires sophisticated approaches to complexity and uncertainty. Conceptual models are increasingly used to improve understanding of complex system interactions. However, cursory treatment of governance limits their analytical potential. This study included governance considerations in a social-ecological system model of biodiversity conservation in the Tasmanian Midlands (Australia). Effectiveness of engagement processes and conservation programme longevity were identified as critical governance influences. The conceptual representation of this system enabled exploration of how governance influences interact with social drivers (e.g. landholder engagement in conservation practices) to modify the effect of biophysical drivers (e.g. land use) on biodiversity outcomes. Such a methodology provides essential information for identifying and guiding governance related points of intervention. 相似文献
67.
Reducing Nitrogen Export from the Corn Belt to the Gulf of Mexico: Agricultural Strategies for Remediating Hypoxia
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Eileen McLellan Dale Robertson Keith Schilling Mark Tomer Jill Kostel Doug Smith Kevin King 《Journal of the American Water Resources Association》2015,51(1):263-289
SPAtially Referenced Regression on Watershed models developed for the Upper Midwest were used to help evaluate the nitrogen‐load reductions likely to be achieved by a variety of agricultural conservation practices in the Upper Mississippi‐Ohio River Basin (UMORB) and to compare these reductions to the 45% nitrogen‐load reduction proposed to remediate hypoxia in the Gulf of Mexico (GoM). Our results indicate that nitrogen‐management practices (improved fertilizer management and cover crops) fall short of achieving this goal, even if adopted on all cropland in the region. The goal of a 45% decrease in loads to the GoM can only be achieved through the coupling of nitrogen‐management practices with innovative nitrogen‐removal practices such as tile‐drainage treatment wetlands, drainage–ditch enhancements, stream‐channel restoration, and floodplain reconnection. Combining nitrogen‐management practices with nitrogen‐removal practices can dramatically reduce nutrient export from agricultural landscapes while minimizing impacts to agricultural production. With this approach, it may be possible to meet the 45% nutrient reduction goal while converting less than 1% of cropland in the UMORB to nitrogen‐removal practices. Conservationists, policy makers, and agricultural producers seeking a workable strategy to reduce nitrogen export from the Corn Belt will need to consider a combination of nitrogen‐management practices at the field scale and diverse nitrogen‐removal practices at the landscape scale. 相似文献
68.
The constructive use of coal-fired power station waste products for building artificial reefs is being explored for the first time in the U.K. at present, the practice of sea dumping of raw pulverised fuel ash (PFA) from coal combustion is under review and the use of consolidated PFA blocks offers a possible alternative. the planned fitting of flue gas desulphurisation (FGD) plant in the U.K. will additionally produce large quantities of gypsum. to test the environmental compatability of such materials in marine structures, an experimental reef has been constructed off the central south coast of the U.K. Fifty tonnes of blocks made from different combinations of PFA, gypsum, FGD waste water sludge, cement and gravel using standard concrete as the control material, were deployed. the site selected is remote from prominent sea bed features in an area of flat sand with limited species variety.The preliminary studies leading to the licensing of this project included bioassay experiments with diatom cultures, field trials with test tiles and trace metal bioaccumulation studies the stages of consultation and licensing of the project are outlined. Colonisation of the reef has been rapid, initially by shoaling fish, particularly by bib (Trisopterus luscus) then, within the first month, by representatives of the commercial crab and lobster species typical of the local natural rocky coast. After three months the epifauna and flora were well established. at this stage some 80 species of flora and fauna have been identified in association with the reef with no differentiation in colonisation apparent between the PFA/gypsum mixtures and the concrete control. the number of species far exceeds that of PFA powder dumping grounds. Analyses for heavy metal ions in the reef blocks after 2 months immersion have not shown any significant difference from the original composition. 相似文献
69.
Michael P. Harris Doug Beare Reidar Toresen Leif Nøttestad Matthias Kloppmann Hendrik Dörner Kevin Peach Derek R. A. Rushton Judy Foster-Smith Sarah Wanless 《Marine Biology》2007,151(3):973-983
Since the early 2000s routine fish surveys have recorded increasing numbers of snake pipefish, Entelurus aequoreus, in the northeast Atlantic. Fishermen and divers have also commented on this increase and pipefish have started to appear
in the diet of seabirds and other marine predators. This paper collates information from these diverse sources and assesses
the current status of snake pipefish. We found compelling evidence of a dramatic increase in the abundance of snake pipefish
starting around 2003 and continuing up to the present (2006) and a range expansion northwards to Spitzbergen and the Barents
Sea. Since 2004 snake pipefish have been increasingly recorded in the diet of many species of seabird breeding in colonies
around the coast of the UK, and in Norway, Iceland and the Faeroe Islands. Information on the nutrient value of snake pipefish
is currently lacking but their rigid, bony structure makes them difficult for young seabirds to swallow and there are numerous
records of chicks choking to death. Thus, in the case of avian predators during the breeding season, it appears unlikely that
increased abundance of snake pipefish will provide a useful alternative prey. The reason for the rapid and dramatic increase
in numbers of snake pipefish is currently unclear but such events are characteristic of marine ecosystems and will almost
certainly have an effect on food web dynamics. 相似文献
70.
Doug Beare Franz Hölker Georg H. Engelhard Eddie McKenzie David G. Reid 《Die Naturwissenschaften》2010,97(9):797-808
Marine protected areas (MPAs) are attaining increasing importance in the management of marine ecosystems. They are effective
for conservation in tropical and subtropical areas (mainly coral and rocky reefs), but it is debated whether they are useful
in the management of migratory fish stocks in open temperate regions. World War II created a large marine area within which
commercial fishing was prevented for 6 years. Here we analyse scientific trawl data for three important North Sea gadoids,
collected between 1928 and 1958. Using statistical models to summarise the data, we demonstrate the potential of MPAs for
expediting the recovery of over-exploited fisheries in open temperate regions. Our age-structured data and population models
suggest that wild fish stocks will respond rapidly and positively to reductions in harvesting rates and that the numbers of
older fish in a population will react before, and in much greater proportion, than their younger counterparts in a kind of
Mexican wave. Our analyses demonstrate both the overall increase in survival due to the lack of harvesting in the War and
the form of the age-dependent wave in numbers. We conclude that large closed areas can be very useful in the conservation
of migratory species from temperate areas and that older fish benefit fastest and in greater proportion. Importantly, any
rise in spawning stock biomass may also not immediately result in better recruitment, which can respond more slowly and hence
take longer to contribute to higher future harvestable biomass levels. 相似文献