Life Sciences Commons^™

Assessing Nordihydroguaiaretic Acid Properties And Its Potential Therapeutic Effect For Glioblastoma, Jose Arturo Guerrero

Open Access Theses & Dissertations

This study employs a combination of theoretical and experimental analysis to spectroscopically investigate the biomechanistic structure relationship and therapeutic effects of the Nordihydroguaiaretic Acid (NDGA) chemical derived from the Larrea Tridentata plant. These relationships are crucial for understanding NDGA's efficacy in disease prevention, treatment, and potential toxicological effects. While the medicinal and antiviral properties of the NDGA have been studied extensively, there remains a gap in optically identifying and reporting its structural changes. The current research successfully reveals evident trends in NDGA's vibrational signatures, particularly highlighting the absence of the Raman feature at 780 〖cm〗^(-1) as indicative of a fully …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

Evaluation Of Evapotranspiration Estimates Using An Existing Hybrid Machine Learning Model In A Natural And A Managed Dryland Site, Katya Esquivel Herrera

Open Access Theses & Dissertations

Evapotranspiration (ET) is a critical component of the hydrologic cycle, encompassing both evaporative water loss from surfaces and transpiration through plant stomata. The environmental factors influencing ET include water and energy availability, atmospheric capacity for water uptake, and various meteorological variables. ET serves as a unique climate variable linking water, energy, and carbon cycles. In agroecosystems, accurate ET quantification is vital for optimizing water use efficiency, irrigation management, and crop yield. Traditional methods for ET estimation involve direct measurements and indirect models, with both presenting limitations.

Recent years have witnessed the integration of remote sensing and machine learning (ML) algorithms …

Temporal Trends In Dryland Soil Carbon Fluxes In Response To Artificial And Natural Pulsed Moisture Events, Briana Alyce Salcido

Open Access Theses & Dissertations

Critical zone processes in drylands play a crucial role in the global carbon cycle, and one of the most important processes is soil CO2 efflux at the interface between soils and the atmosphere, which represents a main pathway for loss of carbon. Predicting the carbon dynamics at this interface is challenging due to the complexity of belowground processes, which include both biotic (soil respiration) and abiotic (calcite precipitation) production of CO2, as well as transport processes that include both diffusive and advective components. In this study, we aimed to investigate the contribution of soil air displacement to soil CO2 efflux …

Characterizing Spatial Variability In Soil Co2 Fluxes In The Chihuahuan Desert Using Geostatistical Techniques, Viridiana Orona

Open Access Theses & Dissertations

Spatial variability in soil CO2 efflux across landscapes is an important feature of the â??Critical Zoneâ?? within dryland ecosystems. In dryland critical zones, resources are often distributed in patches or resource islands. Although this is particularly true in natural settings, the significance of spatial variability in CO2 efflux and its patterns also extends to dryland agriculture. In both irrigated and unirrigated systems, human management practices can significantly impact both organic and inorganic carbon cycling processes, highlighting the importance of studying CO2 efflux in these systems. We examined the spatial patterns of soil CO2 efflux and quantified the magnitude and scale …

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …

Land Use/ Land Cover Change Patterns And Trends In Two Dryland Regions, Omar Sulaiman Belhaj

Open Access Theses & Dissertations

Development and climate change affect the environment in numerous ways and to varyingdegrees. This effect appears prominent and more influential in arid regions. Therefore, land use/ land cover in these regions experience profound changes such as plant cover decrease and extinction of some plant species. Also, land use/ land cover in these regions has critical impacts on the environment and its components, such as shrublands shrinking and losing the habitat of animal species. The degree of changes and effects reaches severe levels that become urgent to figure out the impacts and find solutions to stop or mitigate the negative consequences. …

Chihuahuan Desert Rock Pool Community Assemblages: Patterns Of Taxonomic Diversity, Joseph Lee Mcdaniel

Open Access Theses & Dissertations

As climate change continues to become more prevalent, increasing temperatures and altering precipitation patterns will disrupt the environmental balance of ecosystems and spark the imminent threat of a 6th mass extinction event. Many researchers believe this has already begun, as losses for numerous taxonomic clades have been well documented; however, the loss of invertebrates is still unknown and may be much more severe than those of other animal clades. A significant factor contributing to the shortfall of invertebrate biodiversity loss is rooted in the lack of understanding of the diversity and distribution of these animals. There is still much to …

Water Sourcing Strategies Of Desert Vegetation In Varying Soil Textures With Vegetation Competition: A Stable Isotope Analysis, Martha Elizabeth Gardea

Open Access Theses & Dissertations

Recent studies have suggested an ecohydrological separation of water exists in the northern Chihuahuan Desert, where vegetation types, rainfall regimes, and location in the terrain seem to determine the type of water (e.g. isotopically depleted or enriched in 18O and 2H) plants are able to source and use throughout their growing cycle. That work found evidence of creosote (Larrea tridentata) and mesquite (Prosopis glandulosa) using tightly bound soil water at both a site on an ephemeral channel and a site in higher elevated flat area because the isotopic signature of plant water at the beginning of the study did not …

Population Genetics Of Two Sympatric Species, The Round-Tailed Horned Lizard (Phrynosoma Modestum) And The Greater Earless Lizard (Cophosaurus Texanus), In The Indio Mountains Of West Texas, Logan Miles Horne

Open Access Theses & Dissertations

Population genetics of two sympatric species, the round-tailed horned lizard (phrynosoma modestum) and the greater earless lizard (cophosaurus texanus), in the Indio mountains of West Texas.

Nanotechnology-Based Approaches To Mitigate Environmental Pollutants -- Induced Neurological Disorders, Jyoti Ahlawat

Open Access Theses & Dissertations

Neurodegenerative diseases such as Parkinson's disease (PD), Alzheimerâ??s Disease (AD) and Huntingtonâ??s Disease (HD) have no cure despite intensive research efforts geared towards therapeutics development. In the USA, patients with PD and AD alone cost the nation ~ $200 billion annually in patient care and lost productivity. Therefore, there remains an urgent and unmet need to develop novel drugs and drug carriers with the potential to slow down, halt and ideally reverse the course of neurodegenerative disorders. The dissertation focuses on developing approaches towards targeting PD using multifactorial mechanisms including the targeting of protein aggregation and oxidative stress. This is …

Impact Of Xenobiotics On Neuronal Outcomes, Gabriela Henriquez

Open Access Theses & Dissertations

Neurodegenerative diseases are a common affliction of the Central Nervous System. They are caused by age, genetics, and environmental factors. Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic Lateral Sclerosis are well-known among the host of neurodegenerative disorders, with Alzheimer's disease and Parkinson's disease being the leading pathologies across this canvas. It is known that the pathogenesis of neurodegenerative diseases is multifactorial due to the involvement of genetic mutations, radical-induced protein damage, abnormal aggregation of misfolded proteins, and the formation of amyloid deposits. The amyloid proteins in neurodegenerative disease include Tau and Amyloid (Aβ) in Alzheimer's disease and α-Synuclein in …

Linking Plot And Landscape Level Phenology, Alejandra Flores

Open Access Theses & Dissertations

Plant phenology has become popularize since the 1990s to help understand the effects of climate change on vegetation, it is a way to study the patterns of leaf-out, flowering, and senescing of the life-cycle of the plant. The timing from start of season (SOS) to end-of-season (EOS) of plant leaf-out development has important implication on ecosystem productivity and carbon cycling across ecological scales from individual trees to whole regions. The need for plant phenology studies in dryland are highly anticipated, since they make up 40% of the terrestrial landscape and recently have shown the play an important role in the …

Articulating The Importance Of Broader Relevance In Cures: From Definition To Actualization, Nikki T. Donegan

Open Access Theses & Dissertations

Course-based undergraduate research experiences (CUREs) have emerged as a means to foster student' scientific reasoning, promote positive attitudes and motivations toward research, and increase persistence in the science, technology, engineering, and mathematics (STEM) fields. In contrast to prescriptive laboratories, students enrolled in CUREs employ techniques and skills to collaboratively and iteratively address novel questions of broad relevance to audiences beyond the scope of the course itself. While many of the core components of CUREs are perceived to be relatively straightforward, definitionally-speaking, this latter dimension of broader relevance has, in contrast, remained largely ill-defined. In the series of studies presented herein, …

Pacific Black Duck Ecology And Habitat Assessment In Aunu'u, American Samoa, And Their Relationship To Other Mallard-Like Ducks Of Oceania, Greater Indonesia, And The Philippines, Marissa Kaminski

Open Access Theses & Dissertations

Determining a species’ ecological needs, assessing the quality of their habitat, and determining genetic differentiation and connectivity among populations is essential to their conservation. My dissertation focuses on obtaining such a holistic view for a population of Pacific Black Ducks recently established on the Island of Aunu’u, American Samoa. Specifically, I present the first evaluation of the ecology and habitat of a recently established population of Pacific Black Ducks on the Island of Aunu’u, American Samoa, in Chapter 1, while I assess the genetic connectivity and relationship of this population to other Mallard-like ducks found in Greater Indonesia, Oceania, and …

Antioxidant Intervention In Radical-Induced Protein Damage, Emmanuel Zubia

Open Access Theses & Dissertations

Many environmental toxicants are known to increase free-radical production, which can create cellular havoc and lead to a myriad of ailments. Antioxidants can be used to ameliorate the prevalence of free radicals, potentially serving as prophylactics against radical-induced disorders. Many exogenous antioxidants are phytochemicals in origin, such as ascorbic acid, gallic acid, and ellagic acid. Some of these antioxidants can be found in traditional medicine, like tanshinone and brazilin, which have been studied and are known to have low cytotoxicity. Here we test the radical rescue capacity of a selected group of phytochemical antioxidants on protein rescue models. Specifically, our …

Partitioning Variation In Vegetation And Landscape Functionality In Arid Land Piosphere, Eahsan Shahriary

Open Access Theses & Dissertations

A piosphere is an interaction between vegetation community, watering point, and grazing livestock/wildlife. In this Dissertation, I begin by reviewing the concept of the piosphere, and the progress, knowledge gaps and common statistical approaches and errors in piosphere research. Landscape functionality, plant community distribution and their influencing factors on a piosphere in Iran are then investigated.

A total 862 piosphere publications of multiple types from 68 countries and 10 different languages during the period of 1915 â?? 2018 were reviewed. Australia was the most productive country followed by South Africa, the USA, Botswana and Argentina. Ivan Thrash is the most …

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 …

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 …

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 …

Insights Into The Interaction Of Copper Oxide Nanopar-Ticles With Sweetpotato (Ipomoea Batatas (L.) Lam.): The Role Of Lignin On Copper Uptake And Translocation, Nestor Javier Bonilla Bird

Open Access Theses & Dissertations

Sweetpotato [Ipomoea batatas (L.) Lam.] is widely cultivated in many countries worldwide. The world production of sweetpotato is around 127 billion tons and it is ranked seventh in the world as a staple food. After harvesting, sweetpotato storage roots are treated with fungicides to prolong shelf life. Lignin plays an important role in the conservation of the storage roots. One of the practices to activate the lignification pathway is called “curing process.” The roots are placed under 80% relative humidity at a temperature of 29 ºC for a period of 7 to 15 days, followed by a cooling period at …

A Combined Field, Experimental And Modeling Approach To Understand The Impacts Of Flood Irrigation On Pedogenic Caco3 And Co2 Dynamics In Drylands, Anna Cristina Ortiz

Open Access Theses & Dissertations

Soil salinization is a global problem affecting 10% of agricultural soils, particularly in irrigated arid-lands. This study investigated salt loading through flood-irrigation, particularly of calcite (CaCO3) salt in the southwest of the United States. To evaluate the impact that flood-irrigation has on CaCO3 buildup and its effect on C-cycling, a natural soil and two agricultural soils were sampled: a pecan orchard and an alfalfa field in the El Paso, TX region. Agricultural soils in this study are flood irrigated by the Rio Grande river and by ground waters in its absence, both of which are oversaturated with calcite.

To trace …

Environmental And Genetic Factors Affecting Antibiotic Resistance Of Extended Spectrum Î?-Lactamase Bacteria From The Rio Grande River In El Paso, Tx And Cd. Juarez, Mexico, Maria D. Fuentes

Open Access Theses & Dissertations

Background: The Rio Grande River provides a major source of potable and agricultural water for the population of the Texas/Mexico border region. Cattle farming and ranching are the most prevalent activities, which may contribute to the microbial burden of pharmaceuticals into our state's water resources. Antibiotics, presumably released into the environment by discharges originating from waste-water treatment plants, septic disposal systems, animal feeding operations and urban runoff have a definite impact on the ecosystem and may contribute to an increase in antibiotic resistance. We hypothesized that waters of the Rio Grande River contained Multi Drug Resistant Organisms (MDRO) and mobile …

Massively Parallel Computational Studies Of Material Response At High Strain Rate Deformation, Jayalath Abeywardhana Mudiyanselage Madawa Abeywardhana

Open Access Theses & Dissertations

Large scale molecular dynamics (MD) simulations are now commonly utilized to study materials at extreme conditions: high pressure and/or temperatures and ultra-high strain rates of deformation. A variety of emerging architectures such as general purpose graphics processing units (GP-GPU) and many-integrated core (MIC) architecture as well as new execution models have changed the traditional approach of high-performance computing. ExMatEx, the DoE initiative for enabling exa-scale (10^18 flops) performance in scientific applications, has developed several proxy applications to facilitate co-design of novel algorithms and hardware by software developers and microchip vendors.

We have used CoMD, a proxy application for classical MD, …

Modulation Of The Physiological And Biochemical Effects Of Copper Nanoparticles In Kidney Beans (Phaseouls Vulgaris) Treated By Kinetin, Suzanne Annette Apodaca

Open Access Theses & Dissertations

It is imperative to not only understand the impact of engineered nanomaterials (ENMs) in edible plants, but also the interactions they have with various additives used in agriculture. In this study, kidney bean plants were grown in potting soil treated with nano copper (nCu), bulk copper (bCu), and copper chloride (CuCl2) at concentrations of 0, 50, and 100 mg/kg for 55 and 90 days. At 15 days of growth, 0, 10, and 100 μm of kinetin (KN) were applied to plants. Plant tissue samples were harvested at 55 days and seeds were reaped at 90 days. Physiological and biochemical parameters …

Spatiotemporal Variability Of Plant Phenology In Drylands: A Case Study From The Northern Chihuahuan Desert, Naomi Robin Luna

Open Access Theses & Dissertations

With global change, which includes climate change, there is a sense of urgency to understand how shifts in climate will affect ecosystems. Although several studies have improved understanding of how and why some ecosystems respond, most studies have not explored simultaneous responses of different land cover types throughout a given region. Dryland ecosystems, such as the Chihuahuan Desert, appear to respond to climate variability and currently make up about 40% of global land surface area. It is expected that drylands will expand to cover 60% of land surface area on earth by mid-century making this ecosystem more critical to global …

Evaluating The Effects Of The Phytohormone Indole-3-Acetic Acid In The Response Of Green Pea (Pisum Sativum L.) To Nanoscale Cuo Exposure In Soil, Loren Ochoa

Open Access Theses & Dissertations

The response of plants to copper oxide nanoparticles (nCuO) in presence of the phytohormones such as IAA, is unknown. In this study, green pea (Pisum sativum) plants were cultivated to full maturity in soil amended with nCuO, CuO bulk (bCuO), and CuCl2 at 50 and 100 mg/kg and indole-3-acetic acid (IAA) at 10 and 100 µM. Several analytical techniques were used to evaluate the effects of treatments in the agronomical, physiological, and biochemical effects of treatments. Results showed that only CuCl2 reduced root length and number of leaves. Root copper (Cu) increased in plants exposed to nCuO without IAA; however, …

Exploratory Study Of Seasonal Indoor Bioaerosols And The Associated Health Outcomes In Low-Income Communities In El Paso, Texas, 2014, Eric Martinez

Open Access Theses & Dissertations

Introduction: Structural degradation, moisture levels, and building failures can influence poor indoor air quality and create a good environment for bioaerosols. People spend much of their time indoors and can potentially be exposed to these bioaerosols. Several studies have correlated exposures to high concentrations of bioaerosols to various health problems, severe allergies, asthma, or other respiratory illness. Objectives: The objectives of this study are to describe bioaerosol concentrations, meteorological factors, and health outcomes during the summer and fall seasons; characterize bioaerosols (bacteria and fungi) collected in low-income communities; compare bioaerosol concentrations by season; compare meteorological factors to bioaerosol concentrations by …