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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

An Adaptive Visual Learning Approach for Waterborne Disease Prevention in Rural West Africa

Oglesby, Jonathan Le Mar 01 April 2016 (has links)
Depleted water supplies, along with industrial and human waste, are driving a world water crisis that poses a growing risk to food markets, energy production, political stability, and human health (Global Water Security 2012). One obvious example of the this crisis is the more than 1 billion people who obtain their drinking water from contaminated sources (WHO/UNICEF 2006; Clasen et al. 2008). With a projected increase of 1.3 billion people between now and 2050, Africa will add more to the global population than any other world region (Haub and Kaneda 2013). For this research, visual learning design factors were incorporated into water literacy materials in order to study ways in which cultural and societal barriers can be overcome through culture- and gender-appropriate graphics designed to foster visual storytelling in the West African country of Niger. Women were targeted as the study population since they are the primary water fetchers and handlers in sub-Saharan Africa. Eye-tracking technology and GIS tools were used for quantification of the visual design characteristics. Research was conducted in 23 villages along the Niger River, and included 510 interviews, 693 focus group participants, 9 different cultural groups, over 30 hours of audio interviews, and 464 eye-tracking trials. Tobii X2-60 eye-tracking equipment was used in bush maternity wards, medicinal depositories, and mud-brick homes. Eye-tracking data were imported into an ArcGIS platform, where kernel density estimation (KDE) analyses were performed in an effort to compare and contrast the KDE of varying education levels, age groups, ethnic groups, and village types. Spatial autocorrelation analyses were used to evaluate whether the spatial pattern of attribute values (fixation time) was clustered, dispersed, or random. Results from this research suggest that visual communication can be used to overcome low education and cultural barriers for waterborne disease prevention. Using an adaptive visual-learning approach for the research method provided a creative alternative to conventional water-education materials, as most do not consider mother tongue and low literacy. Through visual communication, a novel way has been developed to understand how disadvantaged populations in sub-Saharan Africa visually process water literacy materials.
52

Mobility of <em>Escherichia coli</em> within Karst Terrains, Kentucky, USA

Bandy, Ashley M. 01 January 2016 (has links)
Bacterial contamination of karst aquifers is a concern as water quality across the globe deteriorates in the face of decreasing water security. This study examined the transport and attenuation of two non-virulent isolates of Escherichia coli in relation to traditional groundwater tracers such as rhodamine WT dye and latex microspheres in two karst regions in Kentucky. Differential movement between the four tracers was observed in both epikarst and karst aquifer traces, with differences in behavior dependent on flow conditions. Attenuation was greater for the bacterial isolate containing the iha gene, compared to the isolate containing the kps gene. Microspheres of comparable size (1 µm diameter) were more easily remobilized during increases in discharge during the observed periods for both study sites. Bacteria were remobilized during storm events over 1 month after injection. Recoveries of tracers that were < 100% combined with observed remobilization during storm events illustrate the storage capacity of epikarst and karst aquifers with regard to potential contaminants.
53

Speciation, Distribution, Prediction, and Mobility of Lead in Urban Soils: A Multiscale Study

Bower, Jennifer 01 January 2017 (has links)
Lead (Pb), a trace metal notorious for its impacts on human health, has achieved worldwide environmental dispersal resulting from centuries of use by human society. The toxicity of Pb is governed largely by its mineral form, which is in turn controlled by pH, localized reactivity and soil processes that differ according to soil type, location and Pb source. Given the context of these localized dependencies, or site specificity, efforts to predict Pb toxicity and refine sustainable remediation techniques are most useful when Pb behavior is constrained and predicted within environments with homogeneous conditions, such as a single soil. I evaluated and predicted the behavior of Pb, a typical anthropogenic contaminant, within a single soil using bioaccessibility testing and predictive geospatial modeling to assess potential impacts and refine sustainable remediation methods. To test the hypothesis that Pb speciation is influenced by competitive sorption processes in soils, I investigated changes in mobility and speciation of Pb upon addition of amendments at multiple scales using flow-through column experiments, soil characterization and synchrotron-based x-ray techniques. Kriging and cokriging maps provided a successful estimation of background and total Pb, the latter incorporating housing age as a secondary variable to increase model accuracy, though efforts to automate detection of background Pb were complicated by approximation of building extents, and overall heterogeneity of soil Pb concentration gives high error. Acute Pb heterogeneity is observed at the scale of a single site among near-structure samples. At the city-scale, determination of bioaccessibility revealed that bioaccessible and total Pb are well-correlated, to the extent that bioaccessibility may be predicted for the soil underlying Burlington, VT; this information, combined with predictive blood lead level modeling and the CDC's recent establishment of 5 μg kg-1 as a threshold for blood lead toxicity, enabled the establishment of a site-specific revised soil Pb limit of 360 mg kg-1, lower than the EPA's general soil Pb threshold of 400 mg kg-1. Characterization of leached and unleached soil using scanning electron microscope energy dispersive spectroscopy (SEM-EDS) and microfocused x-ray techniques provided a first look at Pb paint species using synchrotron technologies. Pb was present within paint chips as hydrocerussite, but appeared to weather to anglesite over time. Pb also seemed to act as cation bridge, attracting clay minerals electrostatically and becoming incorporated into heterogeneous soil aggregates. Accessory paint elements are identified in soil and within paint chips and may further complicate these systems. Column experiments, at acidic pH, yielded little evidence of Pb mobility change in response to modification of competitive sorbents. Kinetics of Pb release were driven by pH, with Pb solubilizing at pH of ˜4.9 as column soil acidifies. This work provides evidence for changes in Pb speciation over time in urban soils impacted by Pb paint, and presents a framework for predictive risk analysis at a local site using experimental and modeling tools. Multiscale observations and analytical results can be used in future efforts to model and refine sustainable remediation solutions within a site-specific context.
54

Promoting Time in Nature for Children: Investigating the Role of Provider Nature Relatedness

Gauderer, Lindsey 01 January 2015 (has links)
Research has shown that time spent in and exposure to natural environments has numerous benefits for children, both physical and mental. At the same time, children face many barriers to obtaining time in the outdoors and today's youth spend less time outside than previous generations. Initiatives such as health care provider prescriptions for outdoor activity aim to encourage exposure to nature as a health intervention for children. In order to enhance the potential for success of programs such as these, factors influencing their implementation need to be assessed. This study aims to explore the impact that provider connectedness to nature, as measured by a validated connectedness to nature scale, has on the likelihood of utilizing a nature prescription program. This study is of descriptive correlational design utilizing a convenience sample of providers who participated in a park prescription program in the state of Vermont. Participants completed a survey that included a Nature Relatedness (NR) scale. These scores and responses were then analyzed in relationship to the number of nature prescriptions written during the program. Data analysis includes descriptive statistics, Pearson's r and Spearman's r and Multivariate MANOVA. Results from this study do not indicate a relationship between provider NR and utilization of a nature prescription program. Data from this study indicates that programs utilized by providers to promote time in nature, such as the park prescription program, may enhance provider awareness of the issue and likelihood to address the issue with their patients. This is an important finding for further initiatives aimed at increasing children's time in nature through their primary care providers.
55

Statistical partition problem for exponential populations and statistical surveillance of cancers in Louisiana

Gu, Jin 18 December 2014 (has links)
In this dissertation, we consider the problem of partitioning a set of k population with respect to a control population. For this problem some multistage methodologies are proposed and their properties are derived. Using the Monte Carlo simulation techniques, the small and moderate sample size performance of the proposed procedure are studied. We have also considered at statistical surveillance of various cancers in Louisiana.
56

Odor Monitoring at the New Orleans East Bank Wastewater Treatment Plant

Figinsky, Felicia R 13 May 2016 (has links)
Hydrogen Sulfide is a corrosive, odorous, and hazardous gas that can cause issues for wastewater collection systems and treatment plants. When evaluating hydrogen sulfide concentrations it is important to consider the source, odor causing mechanism, and its level of toxicity. In this study, continuous hydrogen sulfide monitoring was performed for 8 locations within the New Orleans East Bank Wastewater Treatment Plant for a span of 5 months. Hot spots within the plant are located and data analysis is performed based on daily and hourly averages of hydrogen sulfide concentrations. The data was configured to show peak hydrogen sulfide concentrations at specific time intervals throughout the day.
57

The Effects of Contaminated Sediment on the Epidermal Goblet Cells of the Mummichog, Fundulus heteroclitus

Mézin, Laurent C. 01 January 1994 (has links)
Secretion of mucus by epidermal goblet cells is an important first line of defense for teleosts. It protects them against many of the biological, physical and chemical insults they encounter in their environment. This project monitored changes in hemoglobin concentration in epidermal mucus and in the density, diameter and mucus quality of epidermal goblet cells in the mummichog, Fundulus heteroclitus, following exposure to creosote-contaminated sediment. Male fish (200) were exposed for 13 days in flowthough aquaria to either an uncontaminated reference sediment or contaminated sediment containing 30% Elizabeth River sediment. Fish were sampled on Days 0, 3, 7 and 13. The hemoglobin content of their mucus was assessed using a commercial hemoglobin test strip. Their condition index was determined and a portion of their ventral skin was mounted after sequential staining by alcian blue and periodic acid Schiff s reagent. The proportion of the mucin types present in the goblet cells, differentiated by the stains, was determined using light microscopy (600x). The aromatic compound concentrations in test aquaria effluents decreased significantly during the experiment, probably as a result of a reduction in resuspension of the sediment by the fish. The condition index was lower and the mortality rate and occurrence of epidermal lesions were higher in the treated fish than in the control fish. The hemoglobin content in the epidermal mucus of treated fish was significantly higher than in control fish. Significant reductions in both size and density of goblet cells observed in treated fish suggested a mucus secretion rate exceeding its production rate. Significant variations in mucin types occurred in both treatments, most likely as a result of the transfer of the fish from the holding tank to the experimental aquaria. Significant changes in mucin types between treatments did not occur until Day 13 and are not believed to be directly related to the creosote present in the treatment sediment.
58

Hazardous Materials Transportation Flow Survey: An Evaluation of Hazardous Materials Transported in Washington County.

O'Brien, Daniel John 01 December 2001 (has links)
This study examines the transportation of hazardous materials through Washington County, Tennessee. This study incorporates federal, state, and local data in assessing current transportation trends. Data gathering activities included local chemical inventories, hazardous materials transportation flow surveys, hazardous materials rail transportation trends, and hazardous materials incident data. All data were compiled and then analyzed to identify hazardous materials transportation trends in Washington County, Tennessee. This information is pertinent to emergency planners for the preparation of hazardous materials transportation incidents. The data gathered further revealed the need for this type of study to identify changing trends in the transportation of hazardous materials through Washington County, Tennessee. This type of study is essential in identifying risks posed from the transportation of hazardous materials through rural communities.
59

Improving Public Health through Reducing Fine Particulate Matter Pollution

Li, Ying 01 March 2015 (has links)
No description available.
60

Evaluating and Improving the Effectiveness of Vehicle Inspection and Maintenance Programs: A Cost-Benefit Analysis Framework

Li, Ying 13 November 2017 (has links)
Motor vehicle inspection and maintenance (I/M) programs are designed to identify high-emitting vehicles and mitigate their impacts on air quality and climate. I/M programs have been traditionally ranked superior among various vehicle emission control measures by the results of cost-benefit analysis, based on the assumption that these programs will achieve the targeted emission reduction outcomes. However, the actual effects of I/M programs may be greatly uncertain and when this uncertainty is taken into account, these programs may become suboptimal. This study develops a new a cost-benefit analysis framework that links various program design consideration, such as program participation rate, identification rate and effective repair rate, to the public health benefits as well as costs of the programs. This framework helps decision makers to investigate minimum implementation requirements that at least ensure the benefits are greater than the costs of implementing the programs in order to improve the overall effectiveness of the I/M programs. To illustrate the applications of the framework, it was applied to a particulate matter oriented I/M program targeting all diesel-fueled vehicles in the city of Bangkok, Thailand, a large metropolitan area that has been suffering from severe ambient PM pollution mainly attributable to its wide use of diesel-fueled vehicles and motorcycles. It was found that the health benefits achieved from the program are sensitive to several key program design elements, including participation rate and problem vehicle identification rate, fraction of effective repairs and illegal operation rate. Other variables, such as the testing cut-points and vehicle population growth rate, only have modest effects on the overall emission reduction and consequent health benefits. Overall, the performance of multiple variables associated with I/M program design needs to be improved simultaneous in order to achieve the targeted benefits of the program.

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