Physical Sciences and Mathematics Commons^™

Ultrafine Black Carbon: A Cumulative Assessment On The Physiology Of Lung - Derived Cells, M Esther Salinas

Open Access Theses & Dissertations

Combustion-derived nanomaterials are noxious ultrafine (<100 nm) aerosolized by-products generated by human activity. They pose threats to pulmonary health due to their small size, allowing them to penetrate deep into the alveolar regions causing detrimental responses downstream. Indeed, an examination between nanocarbon particle exposure and poor pulmonary health via cellular behavior was needed. I hypothesized that low-dose and long-term administrations of carbonaceous nanoparticles contribute to respiratory conditions by irritating lung-derived cells. Responses to ultrafine black carbon (UBC), a key component of airborne pollutants, by human lung A549 and murine lung LA4 epithelial cells, human peripheral-blood monocytes THP1, and murine macrophages RAW264.7 were investigated. These lines were chosen because epithelial cells and mononuclear cells (monocytes and macrophages) are the first to come in contact with inhaled particulate matter (PM) and contribute to stress and inflammation of pulmonary tissues. The cells were first plated on day zero and fed fresh UBC suspended in culture media on days one, four, and seven. The exposure regimen included three different low-level concentrations of UBC. On day ten, all cells were prepared for subsequent assays. Effects on cellular viability revealed that UBC was modestly cytotoxic while ATPase and esterase activity (termed enzyme vitality for the purpose of this study) were significantly diminished in a dose-dependent manner. Additionally, beta-galactosidase proportionally increased with UBC concentration compared to untreated cells, indicating that cellular senescence was promoted across all cell types. Multiple markers of oxidative stress were subsequently measured, showing non-uniform trends and displaying moderate accumulation of oxidative damage, contingent upon cell line and UBC treatment. However, a significant induction of inner mitochondrial membrane depolarization of human UBC-treated cells was observed; an aberrant cell-cycle progression was found across all cells. The implemented regimen of UBC exposure elicited an imbalance of free (reduced) glutathione, altered mitochondrial potential, and abnormal cell-cycle activity. This method demonstrated that modifications across both species induced changes to cellular fitness overall. The data supported that compounding nanosized black carbon exposure could negatively affect overall pulmonary cell health by distinctively modifying intracellular activity. Additionally, we further surmised that sustained exposure to nanocarbon could impair innate immunity. Therefore, reactive oxygen species (ROS), reactive nitrogen species (RNS), and cytokine levels upon continuous administrations to 3.0 μg/mL UBC after brief challenges to microbial proxies were assessed; on day 9, the cells were succumbed to three different microbial insults (LPS, Poly I:C, and Zymosan). On day 10, measurements demonstrated a moderate accumulation of oxidative stress, conditional to each cell type. Thus, UBC plus microbe approach triggered pro-oxidant levels and cytokine production across different cell types and diminished phagocytic response by murine macrophages. Based on the results, ultrafine-PM exposure may impair inflammatory function in response to pathogenic infections. In summation, our findings indicated that additive nanosized UBC in combination with microbe-like challenges may compromise cellular behavior, suggesting potential ways by which inhalation of ultrafine-PM may contribute to or exacerbate poor pulmonary health.

Manfreda Maculosa Leaf Extracts And Their Effects On Whole And Selected Myotoxic Components In Crotalid Venom, Charles Steven Gilbert

Open Access Theses & Dissertations

Manfreda spp have been used for the treatment of snakebite by several cultures in North and Central America (Austin & Honychurch, 2004, Johnson, 1999, Moerman, 2008, Verhoek, 1978a). There has been no systematic study of the genus Manfreda for its usefulness in the treatment of snakebite.

While the annual incidence of snakebite in the United States is relatively low (approximately 8,000 - 10,000), with a low mortality rate of 5 - 6 cases per year, there is still significant morbidity associated with snakebite (CDC - NIOSH, 2018, Springhouse Corp (eds), 2005). Worldwide numbers of the cases of snakebite can only …

Combination Of Resampling Based Lasso Feature Selection And Ensembles Of Regularized Regression Models, Abhijeet R. Patil

Open Access Theses & Dissertations

In high-dimensional data, the performance of various classiers is largely dependent on the selection of important features. Most of the individual classiers using existing feature selection (FS) methods do not perform well for highly correlated data. Obtaining important

features using the FS method and selecting the best performing classier is a challenging task in high throughput data. In this research, we propose a combination of resampling based least absolute shrinkage and selection operator (LASSO) feature selection (RLFS)

and ensembles of regularized regression models (ERRM) capable of handling data with the high correlation structures. The ERRM boosts the prediction accuracy with …

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …

Potential Of Nanoscale Elements To Control Fusarium Wilt Disease In Tomato (Solanum Lycopersicum), Enhance Macronutrient Use Efficiency, And Increase Its Yield, Ishaq Olarewaju Adisa

Open Access Theses & Dissertations

Nanotechnology has a great potential in ensuring food production, security and safety globally. Over the past decade, research on the use of nanomaterials to supply nutrient elements and protect plants from pest and diseases has significantly increased. Tomato (Solanum lycopersicum) is one of the most consumed vegetables in the world and United State is one of its largest producers globally generating billions of dollars annually in revenue.. Tomato plants are affected worldwide by Fusarium wilt caused by Fusarium oxysporum f. sp. Lycopersici. There is growing concern about excessive use of conventional pesticides in controlling Fusarium and other diseases in tomato …

Non Linear Optics For Materials Fabrication And Medical Instrumentation, Aurelio Paez

Open Access Theses & Dissertations

Two-photon absorption is a nonlinear optical process where two photons are absorbed by a molecule simultaneously. The probability of this quantum phenomenon is proportional to the quadratic excitation of light intensity. It has many applications in biomedical and materials research, such as two-photon fluorescence microcopy. The first project is to apply two-photon absorption induced bond cleavage in photoreactive materials for engineering 3D tissue scaffolds. The major challenge for growing thick 3D tissues is the lack of vasculature, where nutrients and oxygen can be delivered to the growing cells. Our collaborators have synthesized a novel polypeptide that is composed of 34-mer …

Fishers' Ecological Knowledge And Stable Isotope Analysis: A Social-Ecological Systems Approach To Endangered Species Conservation, Kathryn Rose Wedemeyer-Strombel

Open Access Theses & Dissertations

Identifying developmental habitat is essential for understanding population structure and species resiliency, especially for critically endangered species. In long-lived, oceanic, migratory animals such as sea turtles, elucidating developmental grounds is particularly difficult. When data are deficient or challenging to acquire, scientists often lean towards traditional quantitative methods when a social-ecological systems approach could better provide crucial baseline data and guiding information. Fishers’ ecological knowledge (FEK), the combination of experiential and culturally transmitted knowledge, is expert knowledge and should be treated as such. In 2008, FEK led to the “rediscovery” of the critically endangered eastern Pacific (EP) population of hawksbill sea …

Deciduous Shrub Encroachment Effects On Tundra Soil Properties, Daniela Aguirre

Open Access Theses & Dissertations

Deciduous shrub abundance is increasing in tundra ecosystems as an effect of rising temperatures which may change tundra physical properties and, in turn, microbial communities and biogeochemical processes. Two mechanisms through which shrub presence may affect tundra ecosystems were examined in this study; the physical presence of the shrubs and effects of increasing shrub litter inputs. In a sub-arctic alpine tundra ecosystem, dominated by the deciduous shrub Betula glandulosa, both shrub presence (shrub present and removed) and litter quantity (no litter/litter removed, ambient litter, and twice ambient litter) were manipulated; multiple ecosystem properties where measured within the treatment plots over …