Digital Commons Network^™

Bayesian Estimation Of Reproduction Numbers From Distributions Of Outbreaks Sizes: Branching Process Approach, Alberta Araba Johnson

Theses and Dissertations

The Generalized Poisson distribution is useful in modeling epidemiological processes as a branching stochastic processes problem. Our goal is to construct accurate and reliable estimators for the reproduction number (R0) (i.e., the number of secondary infections), particularly in the context of disease outbreaks modeled by a Galton-Watson process. Towards this goal, we construct the classical Bayes estimator, the Maximum Likelihood estimator, and the Empirical Bayes (EB) estimator under the Square Error Loss function in Chapter II. We prove that the Empirical Bayes estimator is asymptotically optimal and estimate the rate of convergence. We then proceed to monotonize the Empirical Bayes …

Soil Carbon Sequestration Efforts In Arid And Semi-Arid Climates Under Conservation Agriculture And Reforestation, Samantha Lynn Colunga

Theses and Dissertations

Soil organic carbon (SOC) plays a vital role in the global carbon cycle and aids in climate change mitigation. However, deforestation and intensive agricultural practices threaten topsoil and carbon (C) pools through soil disturbances releasing vast amounts of carbon dioxide (CO2) by enhancing the decomposition of organic materials. Degraded soils typically lack stable aggregates, nutrient and water retention, and overall low fertility. In arid and semi-arid regions, soils are in an even more dire situation, as low precipitation and high temperatures slow down the accumulation of SOC. This thesis has two objectives: 1) to evaluate whether conservation tillage practices increase …

How Mathematics Instructors Foster The Development Of Black Students' Mathematics Identity In Undergraduate Active Learning Mathematics Courses, Ashly J. Olusanya

Theses and Dissertations

Black students must overcome unique challenges to succeed in mathematics. Educators are tasked with identifying equitable teaching practices to support these students. Active learning (AL) is a teaching pedagogy that engages students in rigorous mathematical activities and encourages student participation. This research study will explore the professors’ beliefs about how students learn mathematics and why they use active learning in their collegiate mathematics courses. The study explores the connections between these beliefs and their reported use of instructional practices. The study also identifies the instructors’ beliefs about developing students’ mathematics identities, particularly their Black …

Studies Of Novel And Well-Defined Dinickel Architectures Utilizing An N-Atom Bridge, David Anthony De Los Santos

Theses and Dissertations

There has been a growing interest in organometallic chemistry to utilize late Earth-abundant metals towards challenging molecular functionalization of abundant feedstocks to value-added products. There is precedent of utilizing cooperativity to try and address some of the shortcomings of traditional mononuclear complexes by integrating metal-metal and or metal-ligand cooperativity to facilitate multi-electron transformations. The utility of a redox-noninnocent scaffold allows for the metal centers to be stable over a range of oxidation states, using the ligand to store electrons. Despite recent progress, complexes harnessing cooperative states towards challenging transformations is still an emerging field. Our group has synthesized a multinucleating …

Synthesis Of Nano-Microstructured Barium Titanate (Batio3) Incorporated In Pvdf-Hfp/Peo For Sustainable And Green Energy Generation, Rigobert Ybarra Jr.

Theses and Dissertations

The global reliance on fossil fuels and natural gas, has largely dominated the energy production field, but due to finite resource depletion and escalating greenhouse gas emissions, the immediate exploration of sustainable energy alternatives to mitigate climate change and ensure resource security has been a major concern. There has been extensive research into other more renewable methods of energy production such as wind and hydropower. Of these current energy generation types there are many areas of untapped potential from the mechanical movements generated ambiently not only in the large scale of power generation but also on a smaller scale. The …

Optimizing Adult Learner Success: Applying Random Forest Classifier In Higher Education Predictive Analytics, Emily Barnes, James Hutson, Karriem Perry

Faculty Scholarship

This study examines the application of the Random Forest Classifier (RF) model in predicting academic success among adult learners in higher education. It focuses on evaluating the model's effectiveness using key statistical measures like accuracy, precision, recall, and F1 score across a comprehensive dataset from 2013–14 to 2021–22, which includes variables such as age, ethnicity, gender, Pell Grant eligibility, and academic performance metrics. The research highlights the RF model's capability to handle large datasets with varying data types and demonstrates its superiority over traditional regression models in predictive accuracy. Through an iterative process, the study refines the RF model to …

Leveraging Blockchain Technology To Revamp The Vehicle Electrification Journey: Perspectives Of Accountability And Economic Circularity, Eva Escobar Brown

Electronic Theses, Projects, and Dissertations

The automotive industry is undergoing a significant transition accelerated by global emission regulations for a phase out of internal combustion engines (ICEs) and a transition toward the adoption of electric vehicles (EVs). While regulatory measures and incentivized adoption for EVs presents opportunities for reducing emissions and promoting sustainability, it also poses complex challenges. The EV industry faces potential production challenges, particularly in the sourcing, manufacturing, and lifecycle management of critical minerals and raw materials for electric vehicle batteries (EVBs). With a heavy reliance on a steady and diversified supply of critical minerals such as lithium, cobalt and rare earth elements, …

Electrochemiluminescence Using Pencil Graphite Electrodes And Screen-Printed Carbon Electrodes Interfaced With A Simple Imaging System, Sandra Ehigiator

Electronic Theses and Dissertations

Electrochemiluminescence (ECL) is a phenomenon whereby electrochemical reactions generate a product that is capable of emitting light. ECL’s high sensitivity, selectivity, extremely low background, and relatively simple instrumentation make it particularly well-suited for chemical sensing and biosensing strategies. Here we report a simple ECL imaging system based on a camera interfaced with a zoom lens to compare pencil graphite electrode (PGE) and screen-printed carbon electrode (SPCE) arrays as ECL platforms. With this system, ECL signals generated from tris(2,2′- bipyridine)ruthenium(II) chloride hexahydrate ([Ru(bpy)3]2+) using co-reactant tri-n-propylamine (TPA) were linear with respect to [Ru(bpy)3]2+ concentrations from 9 to 450 μM. Detection limits …

Enabling Criticality-Aware Optimized Machine Perception At The Edge, Ila Nitin Gokarn

Dissertations and Theses Collection (Open Access)

Cyber-physical systems and applications have fundamentally changed people and processes in the way they interact with the physical world, ushering in the fourth industrial revolution. Supported by a variety of sensors, hardware platforms, artificial intelligence and machine learning models, and systems frameworks, CPS applications aim to automate and ease the burden of repetitive, laborious, or unsafe tasks borne by humans. Machine visual perception, encompassing tasks such as object detection, object tracking and activity analysis, is a key technical enabler of such CPS applications. Efficient execution of such machine vision perception tasks on resource-constrained edge devices, especially in terms of ensuring …

The Effects Of Amphibole- And Sulfide-Producing Melts On Crustal Strength In Gabbros Of Lower Oceanic Crust In Oceanic Core Complexes, Mid-Atlantic And Southwest Indian Ridges, Trevor Hoffmann

Master's Theses

This study investigates gabbro-cored oceanic core complexes in the slow-spreading Mid-Atlantic Ridge (MAR) and the ultraslow spreading Southwest Indian Ridge (SWIR). Dikelets are a texture found in thin section samples from these systems that form as a result of crystal-plastic deformation. Thin section samples from the Atlantis Massif, MARK Area, and 13˚-15˚ North of the MAR and the Atlantis Bank of the SWIR were observed with petrography to find these dikelets and identify what type of dikelet is present. SEM-EDS is used to identify the mineral assemblages present in the dikelets. LA-ICP-MS is used on amphibole to determine if its …

Sheep Grazing Influences The Abundance, Diversity, And Community Composition Of Wild Bees And Other Insects In Livestock Pastures, Roshani Sharma Acharya, Timothy B. Leslie, Joan Burke, Kusum Naithani, Emily Fitting, Kelly Loftin, Neelendra K. Joshi

Entomology and Plant Pathology Faculty Publications and Presentations

Pollinators contribute to the establishment of perennial native forages, but little is known about the effect of grazing practices on pollinator abundance and diversity in livestock pasture ecosystems. Grazing reduces floral resources available to bees and other insects, and as a result, may influence their communities. The main objective of this study was to examine the impact of sheep grazing on bees and other non-bee insects in livestock pasture established with seed mixes of native forb/legume/grass and warm season grasses. Each pasture was divided into two halves (in a split-plot design) using an electric fence in which one plot was …

3d Analysis Of Fe-Ti Oxides And How They Affect Crystal-Plastic Deformation In Atlantis Bank, Southwest Indian Ridge, Sarah Hill

Master's Theses

This project focuses on the importance of the relationship between Fe-Ti oxide abundance and interconnectivity, and crystal-plastic deformation in Atlantis Bank, Southwest Indian Ridge by utilizing Micro-CT scanning. This was done through comparing the Micro-CT scans of 15 samples from three different Ocean Drilling Program and International Ocean Discovery Program drill holes using the Nikon NIS Advanced Research 3-D visualization program and producing plots and statistics from MATLAB. Results indicate a wide range of textures across a range of crystal-plastic fabric intensity and Fe-Ti oxide abundance. Ultimately, there was a generally positive relationship between depth, CPF intensity, and Fe-Ti oxide …

Employing Digital Pcr For Enhanced Detection Of Perinatal Toxoplasma Gondii Infection: A Cross-Sectional Surveillance And Maternalinfant Outcomes Study In El Salvador, Mary K. Lynn, Marvin Stanley Rodriguez Aquino, Pamela Michelle Cornejo Rivas, Xiomara Miranda, David F. Torres-Romero, Hanson Cowan, Madeleine M. Meyer, Willber D. Castro-Godoy, Mufaro Kanyangarara Ph.D., Stella C.W. Self Ph.D., Ms, Berry A. Campbell, Melissa S. Nolan Ph.D., Mph

Faculty Publications

Toxoplasma gondii is a parasitic infection that can be transmitted in utero, resulting in fetal chorioretinitis and other long-term neurological outcomes. If diagnosed early, pregnancysafe chemotherapeutics can prevent vertical transmission. Unfortunately, diagnosis of acute, primary infection among pregnant women remains neglected, particularly in low-andmiddle-income countries. Clinically actionable diagnosis is complex due to the commonality of infection during childhood and early adulthood which spawn long-last antibody titers and historically unreliable direct molecular diagnostics. The current study employed a cross-sectional T. gondii perinatal surveillance study using digital PCR, a next generation molecular diagnostic platform, and a maternal-fetal outcomes survey to ascertain the …

Legislative Recommendations On Biometric Security And Privacy Jurisprudence, Joshua M. Morrow

All Student Scholarship

This project focuses on the prevalence of biometrics today, their various applications, and the biometric laws and legislations in place in the United States (U.S.) and Maine. Due to various threats and vulnerabilities imposing risk on collecting and using peoples’ biometric data, sufficient cyber protections related to citizens’ privacy rights, ethical control, and security of personally identifiable information (PII) must become necessary components of contemporary biometric laws and legislation. Without such explicit cyber protections, citizens participate in and comply with various technical domains and entities, such as private companies and governmental agencies, with minimal awareness or comprehension that their sensitive …

Vaid: Indexing View Designs In Visual Analytics System, Lu Ying, Aoyu Wu, Haotian Li, Zikun Deng, Ji Lan, Jiang Wu, Yong Wang, Huamin Qu, Dazhen Deng, Yingcai Wu

Research Collection School Of Computing and Information Systems

Visual analytics (VA) systems have been widely used in various application domains. However, VA systems are complex in design, which imposes a serious problem: although the academic community constantly designs and implements new designs, the designs are difficult to query, understand, and refer to by subsequent designers. To mark a major step forward in tackling this problem, we index VA designs in an expressive and accessible way, transforming the designs into a structured format. We first conducted a workshop study with VA designers to learn user requirements for understanding and retrieving professional designs in VA systems. Thereafter, we came up …

High-Dimensional Mediation Analysis Of Multi-Omics Data, Sunyi Chi

Dissertations and Theses (Open Access)

Environmental exposures such as cigarette smoking influence health outcomes through intermediate molecular phenotypes, such as the methylome, transcriptome, and metabolome. Mediation analysis is a useful tool for investigating the role of potentially high-dimensional intermediate phenotypes in the relationship between environmental exposures and health outcomes. Rapid development of high-throughput technologies have made mediation analysis of multi-omics data critical to gain groundbreaking insights into the biological mechanisms underlying the disease etiology. This dissertation aims to develop mediation analysis methods that utilize the enormous amount of multi-omics data in assessing mechanisms of disease etiology. It contains three projects where I propose advanced mediation …

Consequences Of The Megafauna Extinction: Changes In Food Web Networks On The Edwards Plateau Across The Pleistocene–Holocene Transition, Quentin A. Smith Jr.

School of Biological Sciences: Dissertations, Theses, and Student Research

We are experiencing biodiversity loss due to climate change and human impacts, which is not only harmful to the environment but can also alter the composition of communities and interactions among species. The late Pleistocene experienced a loss of large-bodied mammals which resulted in significant changes in community structure due to changes in body size, diet, and species associations. The impact of these changes on species interactions and community structure across the Pleistocene-Holocene transition remains poorly understood. Using a robust data set of species composition, stable isotopes, body size, and climate variables, we constructed and compared ecological networks of mammal …

Exploring Graph Neural Networks In Reinforcement Learning: A Comparative Study On Architectures For Locomotion Tasks, Gaukhar Nurbek

Theses and Dissertations

Deep Reinforcement learning (DRL) has gained importance in optimizing control policies, while Graph Neural Networks (GNNs) offer a robust approach for modeling complex relationships within systems represented as graphs. This thesis investigates the integration of DRL and GNNs to optimize control policies for robotic tasks, with a focus on locomotion. It compares static and dynamic GNN architectures for control policy predictions, revealing their strengths and limitations in adapting to locomotion predictions. The study assesses the impact of model structure complexity on GNNs' predictive capabilities, showcasing how intricate model structure can maximize GNNs' potential in capturing spatial and relational dependencies when …

Exploring The Relationship Between Anxiety And Virtual Reality Sickness, David Wesley Woolverton

Graduate Theses and Dissertations (2019 - present)

As virtual reality (VR) becomes more commonly used in education, it is important to understand the technology’s weakness and mitigate any potential negative effects on student success. One adverse side-effect of VR use is simulation-induced motion sickness, known in the context of VR as VR sickness. Previous research by Howard and Van Zandt (2021) found that possessing a phobia had a significant positive correlation with VR sickness, but only if the phobia is triggered by the simulation, suggesting that symptoms are actually connected to the anxiety the phobia induces. This study explored the hypothesized correlation between anxiety and VR sickness, …

Utilizing Electrical Geophysical Methods To Map Mycorrhizal Mycelium Networks Non-Invasively, Donald Pesonen

Graduate Dissertations and Theses

Mycorrhizal mycelium networks are a key component to forest health. These networks act as a transportation system for nutrients, are major players in carbon and nitrogen cycling, and can provide some level of drought resistance to the surrounding flora. Due to the location and size of these network’s filaments, studying mycelium non-invasively has been difficult. The alternative method of laboratory grown samples, lacks the important environmental factors that play into the growth and development of mycelium. Mycelium’s inherent conductivity and moisture retention allows for these networks to be a viable target for electrical geophysical equipment. CMD-Tiny, a small shallow depth …

Modeling Sex-Specific Changes In Myocardial Fibrosis, Grace Martin

Chemical Engineering Undergraduate Honors Theses

Heart disease the leading cause of death for both men and women in the United States. Cardiac fibrosis, or accumulation of extracellular matrix proteins in the heart, can occur after a heart attack and increase the risk for further complications. Current treatments for heart disease do not include extracellular matrix regulators, partly due to the complicated signaling network responsible for the production of these proteins. By using a computational model of the signaling network in cardia fibroblasts, the relationship between particular molecules and downstream extracellular matrix production can be examined.

Biological sex is an important factor for cardiac health and …

Igwas: Image-Based Genome-Wide Association Of Self-Supervised Deep Phenotyping Of Retina Fundus Images, Ziqian Xie, Tao Zhang, Sangbae Kim, Jiaxiong Lu, Wanheng Zhang, Cheng-Hui Lin, Man-Ru Wu, Alexander Davis, Roomasa Channa, Luca Giancardo, Han Chen, Sui Wang, Rui Chen, Degui Zhi

Faculty, Staff and Student Publications

Existing imaging genetics studies have been mostly limited in scope by using imaging-derived phenotypes defined by human experts. Here, leveraging new breakthroughs in self-supervised deep representation learning, we propose a new approach, image-based genome-wide association study (iGWAS), for identifying genetic factors associated with phenotypes discovered from medical images using contrastive learning. Using retinal fundus photos, our model extracts a 128-dimensional vector representing features of the retina as phenotypes. After training the model on 40,000 images from the EyePACS dataset, we generated phenotypes from 130,329 images of 65,629 British White participants in the UK Biobank. We conducted GWAS on these phenotypes …

Using The History Of Statistics To Teach Introductory Statistics, Melissa Hansen

All Graduate Reports and Creative Projects, Fall 2023 to Present

While often taught in high school and required as part of a college degree, statistics classes are sometimes viewed by students as an obstacle rather than a support for their overall goals. One way to increase student engagement in a statistics course is to use the history of statistics. Within the literature review, the advantages to using the history of statistics are discussed as well as the more extensive research on using the history of mathematics in mathematics courses. Included are instructional strategies for using the context around the development of mathematical ideas in math classrooms which can be extended …

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 …

Earth Abundant Catalyst For Evironmental Sustainability Applications, Javier Hernandez

Open Access Theses & Dissertations

The development of experimental methodologies for synthesizing a diverse range of metallic and metal oxide nanoparticles tailored for sustainable water treatment applications was investigated. These nanoparticles are prepared using environmentally friendly and scalable synthesis methods, underscoring their potential for large-scale production. Synthesized nanoparticles are harnessed for various processes, including catalysis and electrocatalysis, with a primary objective of degrading and removing organic pollutants from water. Key to this research is the encapsulation of nanoparticles within solid supports. Multiple methodologies are explored to engineer supports that ensure nanoparticle stabilization, monodispersion, and prevent unintended release into the environment. Two alternative approaches were evaluated …

Combining Green Analytical Methods And Machine Learning To Develop Urinary Fatty Acid Models For Cancer Detection, Elizabeth Noriega Landa

Open Access Theses & Dissertations

This study aimed to explore fatty acids (FAs) as non-invasive biomarkers for prostate cancer (PCa) detection and prognosis, and their potential applications in other cancers. The objectives of this study were: 1) Develop a non-invasive urinary FAs-based model for diagnosing PCa; 2) Develop a FAs-based liquid biopsy model for non-invasive monitoring of PCa progression; 3) Investigate FAs composition in periprostatic adipose tissue (PPAT) collected from PCa positive patients; 4) Investigate the potential of urinary FAs biomarkers for diagnosing clear cell renal cell carcinoma (ccRCC) and ovarian cancer (OC).For the PCa diagnostic model, urine samples from 334 biopsy-confirmed PCa-positive and 232 …

Selective Transfection Of A Transferrin Receptor-Expressing Cell Line With Dna-Lipid Nanoparticles And Synthesis Of Parasite-Derived Glycans As Biomarkers For Leishmaniasis, Irodiel Vinales Lozano

Open Access Theses & Dissertations

Despite notable progress in lipid nanoparticle (LNP)-mediated gene delivery, achieving selective transfection of specific cell types, such as cancer cells, remains a significant hurdle, hindering the advancement of innovative gene therapies. In this study, we engineered an LNP formulation encapsulating plasmid DNA (pDNA) encoding the monomeric Green Lantern (mGL) fluorescent reporter protein. The DT7 peptide ligand targeting human transferrin receptor 1 (hTfR1) was also conjugated to the LNP surface for targeted delivery to hTfR1-expressing cells. Optimization of LNP composition yielded favorable particle diameter, ζ-potential, yield, and pDNA encapsulation efficiency. Evaluation of transfection selectivity using a panel of two engineered cell …

Promoting Social Sustainability: Implementing A Dynamic Stem Driven Framework To Empower Underrepresented Communities In West Texas Schools, Raquel Haggerty

Open Access Theses & Dissertations

This dissertation explores how environmental engineering can utilize STEM education as a strategic tool, enhancing social sustainability and thereby empowering underserved Hispanic communities in West Texas. Responding to significant educational and resource disparities, this research introduces an innovative interdisciplinary framework that combines instruction-initiated resource activation (I2RA), culturally attuned parent engagement (CAPE), and community- centered STEM education (CCSE). This approach uniquely addresses the challenges faced by these communities, integrating environmental solutions with educational advancements to forge a path toward equitable STEM access and achievement.

Additionally, the "Elevate and Empower" case study exemplifies the practical application of this comprehensive framework, demonstrating its …

Synthesis Of Neoglycoproteins As Potential Biomarkers For Chagas Disease And Cutaneous Leishmaniasis Caused By Leishmania (Viannia) Braziliensis, Eileni Rodriguez Gil

Open Access Theses & Dissertations

Protozoan parasites are responsible for causing numerous diseases in humans and mammals worldwide. Among them are Chagas disease (CD), caused by the parasite Trypanosoma cruzi (T. cruzi), and tegumentary leishmaniasis (TL), caused by the parasite Leishmania (Viannia). Both diseases coexist in many regions of Latin America, and current hurdles to differentially diagnose them and determine chemotherapy success need to be overcome. CD can be diagnosed by traditional serological tests and polymerase chain reaction (PCR), but disadvantages of these methods are that they may produce false negatives because the antigens used in commercial CD kits are not conserved across all T.cruzi …

Produced Water: Characterization And Treatment, Ramon Antonio Sanchez Rosario

Open Access Theses & Dissertations

In recent years, environmental concerns have urged companies in the energy sector to modify their industrial activities to facilitate greater environmental stewardship. For example, the practice of unconventional oil and gas extraction has drawn the ire of regulators and various environmental groups due to its reliance on millions of barrels of fresh water for hydraulic fracturing well stimulation, which is generally withdrawn from natural sources and public water supplies. Additionally, this process generates two substantial waste streams, which are collectively characterized as flowback and produced water. Whereas flowback water is comprised of various chemical additives that are used during hydraulic …