Life Sciences Commons^™

High-Content Screening In Zebrafish Embryos Identifies Abamectin As A Potent Neurotoxicant, Tara Diane Raftery

Theses and Dissertations

During development, the nervous system is a sensitive target for chemical exposure in both humans and animal models, and early life-stage exposures can lead to long-term effects on motor activity, sensory function, and cognition. Currently, there are minimal to no developmental neurotoxicity (DNT) data available for thousands of chemicals used in commerce, and it is impractical to screen these chemicals in rodent models using the existing DNT test guideline, as this test is costly, time- and animalintensive, and low-throughput. Therefore, there is a recognized need to use alternative non-mammalian models to support screening and prioritization of chemicals for DNT testing, …

Bacterial Communication And Its Role As A Target For Nanoparticle-Based Antimicrobial Therapy, Kristen Publicover Miller

Theses and Dissertations

The goal of this dissertation is to establish the environmental and public health importance of alternative forms of antimicrobial therapy, specifically those that utilize nanotechnology to combat quorum sensing-controlled bacterial infections. Quorum sensing (i.e. chemical communication) is an inherent characteristic that is essential to bacterial pathogenesis and biofilm formation (where most infections occur). A thorough review of the literature has been conducted to establish an understanding of the state of nanotechnology research as it relates to combatting bacterial infections. This synthesis, provided in Chapter 1, demonstrates how the chemical and structural designs of nanoparticles can be manipulated to specifically target …

Impact Of Gestational Exposure To 2,3,7,8-Tetrachlorodibenzo-P-Dioxin On T Lymphocyte Development, Lori S. Ahrenhoerster

Theses and Dissertations

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous environmental contaminant and the best characterized agonist of the arylhydrocarbon receptor (AHR), a transcription factor crucial to the detoxification of numerous xenobiotics. Studies in animals show that TCDD is immunosuppressive in adult exposures, and epidemiological studies have found an association between TCDD exposure and hematologic cancers. Additionally, developmental exposure to TCDD has been shown to increase the likelihood of autoimmunity and to impair immune response to later-life infections. The cells of the immune system are all descended from multipotent hematopoietic stem cells (HSCs) that originate in the fetus. This multipotency, defined as the ability to …

Carbon Nanomaterials In Freshwater Ecosystems: An Chronic, Multi-Generational, And Genomic Assessment Of Toxicity To Daphnia Magna, Devrah Anne Arndt

Theses and Dissertations

Carbon nanomaterials are synthesized with a variety of core structures and surface chemistries to make them more biocompatible for application in different industries, but variation in core structure and functionalization can change the toxicity of carbon nanomaterials to organisms. In addition, current literature is dominated by data from acute toxicity assays, but meta-data is necessary to improve our understanding of nanomaterial toxicity. This project identifies specific core structures and surface chemistries that make carbon nanomaterials more and less toxic using chronic toxicity assays and multi-generational assays to generate a dataset on the sub-lethal impacts of nanomaterials to Daphnia magna. In …

The Influence Of Maternal Contexts On Infant Outcomes, Secondary Analysis Of Wpcr Data 2000-2010, Mary Roseanne Butler

Theses and Dissertations

Congenital heart defects (CHD) are the most prevalent birth defect in the world and occur in approximately 6-8 of every 1,000 live births (Hoffman & Kaplan, 2002). CHD continues to be one of the leading causes of infant morbidity and mortality today. Five to ten percent of all cases of CHD can be attributed to a chromosomal abnormality, 3%-5% are linked to single gene defects, and approximately 2% are a result of known environmental factors (Clark, 2001). With only 10%-15% of the causes of CHD are understood, the remaining 85%-90% of all CHD cases, the etiologies remain unknown. The purpose …

Effects Of Traffic And Air Pollution On Risk Of Preterm Birth And Low Birth Weight Outcomes In Milwaukee County, 2005-2010, Deborah Lynn Pasha James

Theses and Dissertations

Between 2005 and 2010, infants born to non-Hispanic black mothers experienced a 3-fold elevated risk of infant mortality compared to those born to white and Hispanic mothers. Preterm birth (PTB) and low birth weight (LBW) are strong predictors of infant mortality. To our knowledge, this is the first study of Wisconsin births to evaluate the effect of social and environmental factors on risk of PTB and LBW. We hypothesize that the observed racial inequalities in PTB and LBW are related to traffic density and air pollution. The Milwaukee INFANTS Study used 2005-2010 electronic birth record data (N = 85,045) geocoded …

Estimation Of Aerosolized Antibiotic Resistant Bacteria Concentrations From Wastewater Treatment Facilities Using Spatially-Based Dispersion Modeling, Renee Nichole Dickman

Theses and Dissertations

Pathogenic bacteria can develop resistance to antibiotics to which they were previously sensitive, resulting in increased morbidity and mortality worldwide [1]. The increase in drug resistance in bacteria is an emerging public health concern. The activated sludge tanks of wastewater treatment plants are known sources of antibiotic resistant bacteria. These resistant bacteria can become aerosolized and disperse downwind. Using previously sampled aerosol concentrations and meteorological data, a Gaussian dispersion model was developed to estimate the concentration downwind from a selected wastewater treatment facility. The emission rate was calculated to be 7,941 CFU/m²/sec ± 2,149 CFU/m²/sec. This value was used in …

Decision-Support Tool For Residential Pesticides In The South Carolina Coastal Zone, Lisa Claire Wickliffe

Theses and Dissertations

The Environmental Protection Agency (EPA) is charged with ensuring pesticides do not pose unreasonable adverse risks to the public and to the environment. This is a daunting task with over one billion pounds of pesticides used across the nation each year. The U.S. EPA estimates approximately 75% of all pesticide usage in the U.S. are agricultural while 25% is for home, garden, industrial, commercial, and government applications. One area of application of concern to public health and the environment regarding misuse of pesticides is in residential settings. In these instances, individuals may not have any knowledge of identifying whether they …

Gene Expression Response In Early Developmental Stages Of Rainbow Trout Exposed To Ecologically Relevant Concentrations Of Malathion, Susan Miller

Theses and Dissertations

Understanding the early life stage toxic effects of environmental organophosphate exposure on organism health is crucial to identifying biomarkers that can be used for preventative care. Malathion, a potent organophosphate, is one of the most widely used organophosphates in agriculture and pest eradication. Due to its widespread use, pesticide runoff into area bodies of water poses a great threat to aquatic life and human inhabitants. Acute exposure to high concentrations of malathion causes neurological abnormalities and can result in respiratory failure, muscle spasms, and mental confusion in humans.

In the present study, the effects of malathion are observed following acute, …

Chromate Dissociation From Primer Paint In Simulated Lung Fluid, Tiffany J. R. Morgan

Theses and Dissertations

OSHA has proposed a new strontium chromate exposure standard that would potentially cause Air Force paint facilities to be in violation of the proposed standard if adopted. This proposed reduction make the continued use of chromate containing primer paints very difficult. There is currently no acceptable replacements for chromate containing primer paints on AF aircraft. This study suggests that paint particles with chromate bound in primer paint may be unavailable for bodily absorption if inhaled and a reduced standard for painting applications may be unnecessary. Primer paint overspray was collected into simulated lung fluid (SLF) and allowed 6 hr, 24 …

Heavy Metal Toxicity In Bioremediation: Microbial Cultures And Microscopy, Jason B. Goodbody

Theses and Dissertations

This research employed a variety of microscopy and spread plating techniques to observe the effects of heavy metal treatments on a toluene-selected bacterial population. Microbial colonies were cultured on spread plates and the resulting numbers were compared to respiration data. The mechanisms of reproduction were demonstrated to be more sensitive to metal treatments than were the mechanisms of respiration. Phase contrast, Gram stain, fluorescent microscopy, were used to compare and document a wide variety of bacteria resulting from different metal treatments as well as from environmental changes within the source bioreactor. The removal of sensitive bacteria and the selection of …

Modified Model For Transient Response Of Mrna Synthesis To Magnetic Field Exposure, Timothy W. Crosnoe

Theses and Dissertations

It is a well-known fact that high frequency, or radio frequency, radiation can be directly harmful to biological tissue. The radiation frequencies to which humans are most exposed, however, are the extremely low frequencies, or ELFs. To date there has been no definitive measure for predicting the ability of low frequency electromagnetic radiation to cause adverse biological effects. Two specific measures, average magnetic field and kinetic index, have been used in studies to determine if they are useful predictors of adverse effects, specifically leukemia. Unfortunately, both have shown only marginal results. This thesis analyzed and improved the kinetic index measure …

An Analysis Of 1994 Air Force Toxic Release Inventory Reporting, Brian A. Pollock

Theses and Dissertations

The purpose of this research is to analyze the Air Force's 1994 Toxic Release Inventory data. Statistical tests were used to meet the following research objectives: (1) review the CY 94 data to determine which chemicals were most often reported and which bases and major commands had the most releases in terms of the number of chemicals reported and the amount of chemicals reported and (2) investigate factors which could influence the reporting status of a facility. An analysis of the TRI data showed that dichloromethane was the chemical released in the largest amount while methyl ethyl ketone was the …

Development Of A Comprehensive Base-Level Environmental Training Program For Total Environmental Compliance, William M. Barrett Jr

Theses and Dissertations

The leadership of the Air Force has established a goal of total environmental compliance because it is the right and necessary thing to do. Commitment to this goal can be accomplished through strong leadership, however, achieving this goal can only be accomplished through effective training. The lack of consistent guidance for developing and executing comprehensive base- level environmental training programs has forced bases to develop these training programs by whatever means available to them. This has resulted in a broad variation in the thoroughness of base-level training programs throughout the Air Force. This research effort investigates the relationship between the …

Development Of Field Guidance For Assessing Feasibility Of Intrinsic Bioremediation To Restore Petroleum-Contaminated Soils, John T. Enyeart

Theses and Dissertations

This research evaluated the process of intrinsic bioremediation, also called natural attenuation, and the parameters that affected it. The goal of this study was to use these intrinsic bioremediation parameters to develop a valid prediction of the cleanup duration using this restoration technology. This analysis was limited to a JP-4 release and focused on the remediation of the BTEX constituents to a cleanup level of 10 ppm total BTEX. The review of intrinsic bioremediation found that the BTEX hydrocarbons can aerobically and anaerobically biodegrade. Of the many factors that affect intrinsic bioremediation, those that most influenced its occurrence were the …