Other Pharmacology, Toxicology and Environmental Health Commons^™

Herbicide Toxicity To Non-Target Aquatic Organisms Does Not Increase In Mixtures With Surfactants, Courtney L. Telfort

Honors College Theses

Agricultural herbicides enter aquatic environments after rain events where they affect microscopic aquatic plants (phytoplankton) and animals (zooplankton) that form the base of aquatic food webs. Atrazine, an herbicide with low solubility in water, is often mixed with surfactants such as alkyl polyglucoside (APG) to improve effectiveness. Although APG has low-toxicity, a potential drawback to increased atrazine solubility is greater adverse effects on aquatic organisms. I hypothesized that atrazine and APG decrease phytoplankton abundance more than atrazine alone. Specifically, I predicted phytoplankton abundance should 1) decrease with increasing concentrations of the mixture compared to the same atrazine concentrations individually, and …

Residues Of Thiamethoxam And Mefenoxam In Vegetative And Floral Tissue Of Soybean At The Early Reproductive Stage Resulting From Seed Treatments, Carolina Camargo, Daniel D. Snow, Sathaporn Onanong, Thomas Hunt, Blair Siegfried

Department of Entomology: Faculty Publications

Thiamethoxam with mefenoxam is the most widely used neonicotinoid insecticide/fungicide mixture applied to soybean (Glycine max [L]) as seed treatments. Based on the systemic nature of thiamethoxam and mefenoxam, residues of this insecticide/fungicide mixture may be present in soybean vegetative and floral tissue and negatively impact beneficial insects. Although neonicotinoids are often applied in combination with systemic fungicides, the research on ecological risks of neonicotinoids has been focused on the analysis of these compounds without considering their interaction with other agrochemicals. The objective of this study was to identify the concentration of thiamethoxam and mefenoxam in soybean flowers and …

The Measles Vaccine, Ben Albrecht

A with Honors Projects

This honors project reviews the development of the measles vaccine, and the controversial and debunked research that led to a decrease in vaccinations and an increase in the illness.

Herbal Supplements: Perceptions, Risks And Need For Improved Regulation, Julia Nikati Wright

Senior Projects Fall 2019

Herbal supplements have become widely used in the United States to treat a variety of ailments. Though the market for these supplements have grown since the passage of the 1994 Dietary Supplements Health and Education Act, the FDA has failed to expand its regulation over these products. Herbal supplements in the United States have been found to be contaminated, misbranded, and sold at unsafe doses. These issues can seriously affect the health and safety of consumers. The issue with the quality of these products is coupled with the lack of knowledge about herbal supplements. Scientific research is severely lacking when …

Applying The Concept Of Thresholds In Ecotoxicology With Focus On The Joint Effects Of Habitat Fragmentation And Contamination, Marcos Krull

Dissertations, Theses, and Masters Projects

A threshold can be defined as the point where small changes in an environmental driver produce an abrupt change within a biological system. These changes can occur at different levels of organization, from organisms to ecosystems. Although thresholds seem to be receiving more attention by ecotoxicologist, not much is known about how contaminants cause or affect thresholds at the landscape level, such as habitat fragmentation thresholds. Habitat fragmentation thresholds can occur due to rapid changes in the landscape structure after a certain amount of habitat is lost, which can cause abrupt effects on the movement of organisms, population abundance and …

The Effects Of Bisphenol F On Embryonic Cardiac Output In Zebrafish, Kyle Monnot

Williams Honors College, Honors Research Projects

Bisphenol F (BPF) is an analog compound of the xenoestrogen bisphenol A (BPA). BPA utilization has decreased dramatically due to its detrimental effects as an endocrine disrupter. In place of BPA, BPF is growing to be a ubiquitous chemical in epoxy resin manufacturing. Recent research has begun to investigate the possible endocrinal effects of BPF as an analog of BPA. This study was performed to examine the potential effects of BPF exposure on cardiac parameters of zebrafish (Danio rerio) embryos. Embryos were exposed to 50 µg/L BPF for 48 hours, and cardiac parameters (stroke volume, heart rate, and …

The Opposing Roles Of Glun2c And Glun2d Nmda Receptor Subunits In Modulating Neuronal Oscillations, Zhihao Mao

Theses & Dissertations

N-methyl-D-aspartate receptors (NMDARs) are ligand-gated ion channels consisting of two GluN1 subunits and two other subunits from among GluN2A-2D and GluN3A-3B subunits. NMDARs play critical roles in synaptic plasticity, learning and memory, and higher brain function such as cognition and perception. Dysfunction of NMDARs (hyper-function and hypo-function of NMDARs) are related to various diseases, including stroke, schizophrenia, Alzheimer’s disease, and others. However, to date, NMDARs antagonists have mostly failed in clinical trials due to adverse effects.

NMDARs antagonists replicate the core symptoms of schizophrenia which may underlie its ability to alter neuronal oscillations in the neural circuitry of different brain …

Pyronaridine Exerts Potent Cytotoxicity On Human Breast And Hematological Cancer Cells Through Induction Of Apoptosis, Paulina J. Villanueva, Alberto Martinez, Sarah T. Baca, Rebecca E. Dejesus, Manuel Larragoity, Lisett Contreras, Denisse A. Gutierrez, Armando Varela-Ramirez, Renato J. Aguilera

Publications and Research

The potent antimalarial drug pyronaridine (PND) was tested for its potential as an anticancer drug. After exposing cancerous (17) and non-cancerous (2) cells to PND for 72 hr, PND was found to exhibit consistent and potent cytotoxic activity at low micromolar (μM) concentrations that ranged from 1.6 μM to 9.4 μM. Moreover, PND exerted a significant selective cytotoxicity index (SCI) on five out of seven breast cancer cell lines tested, with favorable values of 2.5 to 4.4, as compared with the non-cancerous breast MCF-10A cell line. By using the same comparison, PND exhibited a significant SCI on three out of …

La Asociación Entre La Contaminación Del Agua Y La Salud En Los Niños Menores De Cinco Años En Villa Garrote, Partido De Tigre / The Association Between Water Pollution And Health In Children Under Five In Villa Garrote, Tigre Party, Morgan Whyte

Independent Study Project (ISP) Collection

La intersección entre el medio ambiente y la salud es un tema central en el estudio de la salud pública porque el acceso a un medio ambiente seguro es esencial para los resultados positivos en la salud. Este tema es particularmente relevante al considerar a Villa Garrote, una pequeña villa situada en el río Reconquista en el municipio de Tigre. Para abordar este tema dentro de esta villa, esta investigación pretende explorar la asociación entre la contaminación del agua y la salud de los niños. Además, los objetivos específicos de este estudio incluyen: investigar los principales elementos que contaminan el …

Macro Implications Of Microplastics: A Comparative Study Of Microplastic Distribution In Bahía Almirante, Bocas Del Toro, Panama, Bonnie Feldberg

Independent Study Project (ISP) Collection

Plastic is one of the most demanded materials in the modern world as it is durable and long lasting. However, that which makes it so commercially appealing also makes it environmentally degrading. Anthropogenic waste and specifically microplastics have been identified in natural habitats globally, with particular interest placed on marine ecosystems. This research aims to add to this pool by comparing microplastic concentrations in beach, mangrove, and shallow ocean sediment in Bahía Almirante, Bocas del Toro, Panama. Sediment samples were collected from each habitat type, processed, and then analyzed to obtain the number of microplastic particles per gram of dry …

Abundance, Density, And Influencing Indicators Of Solid Waste Accumulation And Mitigation Solutions Along Coastlines On Isla Colón In Bocas Del Toro Province, Panamá, Andy Rhodes

Independent Study Project (ISP) Collection

Solid waste accumulation is a significant issue in Latin America where poor infrastructure and management systems are present and with the exponential tourism growth in this region, the abundance of solid waste is also growing. This increase affects environmental, economic, and social factors such as pollution, a decline in tourism, and an increase in negative health effects. This study on Isla Colón, in the Province of Bocas del Toro, in western Panamá sought results on the abundance of solid waste along roadsides and beaches in the most populous and touristic locations. Approximately 2,160 meters squared were studied in Playa Bluff, …

Macrophytes And Atrazine In Ponds Of Southwest Missouri, Christine Michelle Cornish

MSU Graduate Theses

Wetlands are often the ultimate destination of agrochemicals. The increased use of these pollutants has resulted in their increased transport, via runoff and spray drift, into wetlands. Atrazine, a commonly used herbicide, has been detected in surface water, groundwater, soil, and sediment, and has shown to have adverse impacts on aquatic biota, such as fish and amphibians. Few studies have reported on the relationships between atrazine and macrophytes. I measured atrazine concentrations in surface sediments in agricultural, conservation, and golf course ponds of southwest Missouri, and investigated how those concentrations might be related to macrophyte communities, and pond environmental characteristics. …

Defining The Radioresponse Of Mossy Cells, Devon Ivy

Electronic Theses, Projects, and Dissertations

Clinical radiotherapy is used to treat a variety of brain tumors within the central nervous system. While effective, it can result in progressive and debilitating cognitive impairment that can diminish quality of life. These impairments have been linked to hippocampal dysfunction and corresponding deficits in spatial learning and memory. Mossy cells are a major population of excitatory neurons located within the dentate hilus and highly involved in hippocampal circuitry. They play critical roles in spatial navigation, neurogenesis, memory, and are particularly vulnerable to a variety of neurotoxic insults. However, their sensitivity to ionizing radiation has yet to be investigated in …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

The Combined Effects Of Atrazine And Tetracycline On Primary Producers And Zooplankton In Freshwater Microcosms, Madison R. Kelly

Honors College Theses

Widespread use of agrochemicals such as herbicides and antibiotics increases their likelihood of entering aquatic systems in mixture. Despite different modes of action, atrazine (herbicide) and tetracycline (antibiotic) adversely affect non-target photosynthetic organisms, such algae and macrophytes, with the potential to reduce food availability to higher trophic levels. However, the effects of simultaneous exposure to both contaminants have yet to be determined. I hypothesized that a mixture of atrazine and tetracycline affects freshwater communities differently than each compound alone. A microcosm experiment was conducted to test effects of environmentally relevant concentrations of atrazine (1 μg L^-1) and tetracycline …

Consequences Of Environmental Mercury Exposure For Migratory Fitness And Survival Of Passerine Birds, Yanju Ma

Electronic Thesis and Dissertation Repository

Mercury (Hg) is a global contaminant that persists in the environment. The organic form, methylmercury (MeHg) has been shown to adversely affect bird immune function, foraging behavior, navigation, and flight ability. Many songbirds migrate seasonally, a process that consists of multiple endurance flights and refueling at stopovers. Current knowledge of the effects of MeHg on songbird migration and survival is mostly speculative. In this thesis, I present three studies of MeHg in migratory songbirds. In Chapter 2, I assessed the breeding ground MeHg exposure (inferred from feather Hg) of 15 songbird species captured during fall migration at bird banding stations …

Water Capacity Of Paramo Soils, Rafael Robert

Independent Study Project (ISP) Collection

The pȧramo ecosystems in the high Ecuadorian Andes are grasslands characterized by challenging abiotic factors such as low temperatures and high solar radiation. Another key feature of pȧramos is the humidity and water availability in the ecosystem. Pȧramos are very important to the hydrology of the inter-Andean valley because they are water reserves that distribute fresh water to lower elevations. These hydrologic properties are made possible by the porous volcanic ash soils formed by the volcanic arc along the mountain range. This study is focused in the region of Chimborazo approximately 20 km from Riobamba the capitol city of the …

Regulation Of Radioactive Fracking Waste, Elizabeth Ann Glass Geltman, Nichole Leclair

Publications and Research

Natural gas extracted form shale reached record production totals in 2015 in the United States and the US Energy Information Administration (EIA) forecasts natural gas production will continue to increase. Wastes from shale gas extraction can contain the radioactive isotopes radium-226 (Ra-226) and radium-228 (Ra-228), which decay further into radon (Rn). Exposure to radon, a form of naturally occurring radioactive materials (NORM), is the leading cause of lung cancer in the United States, after smoking. This article explores how states handle the disposal of technologically enhanced naturally occurring radioactive materials (TENORM) and/or NORM waste from oil and gas operations to …

Exploring Science Identity: The Lived Experiences Of Underserved Students In A University Supplemental Science Program, Lynette D. Perrault

University of New Orleans Theses and Dissertations

Underserved students attending under-resourced schools experience limited opportunities to engage in advanced science. An exploration into the influence a supplemental science program has on underserved students’ acquisition of science knowledge and skills to increase their pursuit of science was conducted to help explain science identity formation in students. The proliferation of supplemental science programs have emerged as a result of limited exposure and resources in science for underserved students, thus prompting further investigation into the influence supplemental science programs have on underserved students interest and motivation in science, attainment of science knowledge and skills, and confidence in science to promote …

Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali

Theses & Dissertations

Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …