UARK (University of Arkansas )
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Subsurface Characterization Using Electrical Resistivity Tomography (ERT) Integrated with MASW, P-Wave Refraction, and Boring Results
No full textElectrical resistivity tomography (ERT) has gained widespread application in geotechnical engineering as a non-invasive method for subsurface characterization. Despite its versatility, several challenges remain regarding its resolution capabilities, interpretive limitations, and integration with other investigative methods. This dissertation addresses three key applications of ERT, focusing on its effectiveness and limitations in resolving thin subsurface layers, detecting anomalies such as voids, and supporting environmental assessment in river restoration projects.
The first study investigates the ability of ERT to resolve thin, discontinuous clay layers beneath levees, using the Melvin Price Reach of the Wood River Levee on the Mississippi River as a case study. ERT surveys were conducted along both longitudinal and transverse profiles and were compared with multichannel analysis of surface waves (MASW) and historical boring logs. Results showed that while ERT successfully identified broader stratigraphic trends, its resolution was insufficient to reliably detect thin clay layers critical for evaluating seepage potential and internal erosion risk.
The second study evaluates the detectability of subsurface voids of varying sizes and depths in a karst terrain along Texas State Highway 29. A combination of ERT, seismic refraction tomography (SRT), and MASW were employed, along with ground-truthing through boreholes. ERT and SRT provided complementary information, with ERT responding to resistivity contrasts and SRT delineating structural anomalies. MASW, however, was found to be ineffective for this application. The results underscored the importance of a multi-method approach for anomaly detection in complex geological settings.
The third study explores the use of ERT for subsurface characterization following dam removal at Little Sugar Creek in Bella Vista, Arkansas. ERT survey lines were integrated with boreholes to assess sediment layering, bedrock depth, and bank stability. ERT proved effective in delineating erodible fine-grained sediments, coarse gravel deposits, and shale or limestone bedrock. These results provided valuable input for restoration design, erosion risk assessment, and geomorphic modeling.
Collectively, these studies highlight the potential and limitations of ERT in applied geotechnical and environmental settings. While ERT provides valuable spatial coverage and rapid data acquisition, it requires careful interpretation and is best used in conjunction with other geophysical and geotechnical tools. The findings contribute to improved practices for levee assessment, anomaly detection, and restoration planning, and offer practical recommendations for extending ERT to routine geotechnical investigations and infrastructure monitoring
Guns, Policing, and Crime: How the Internet and Social Media Shape Public Opinions
Get PDFI aimed to understand whether and how use of the internet and social media shapes attitudes on gun control, policing, and general crime. I use elements of cultivation theory to explain how exposure to media content insights moral panics and influences public beliefs on issues like guns and policing. Data were drawn from the 2023 Pew Research Center National Public Opinion Reference Survey (N=4,713), an annual survey of United States adults to produce benchmark estimates for various topics. I hypothesized that data from the survey will show frequent social media and internet usage influences attitudes towards crime, policing, and guns. I examined differences by political party affiliation. The findings of this study show that internet and social media use are not significant factors in influencing public opinion on gun ownership, law enforcement funding, and neighborhood crime while control variables of race, gender, education, and political party affiliation do have a significant effect on such issues
Latent Variable Dyadic Regression Models for Predicting Over/Under Bets in Sports Betting
Get PDFThis thesis explores the use of latent factor models to uncover hidden structures in pair wise outcomes derived from Over/Under betting markets in sports betting. Specifically, we implement and evaluate the Eigen model, a latent space model that represents dyadic data using node-specific vectors whose inner product govern edge probabilities. By modeling relationships between teams as adjacency matrices of binary outcomes, we investigate the extent to which the Eigen model captures both homophily, the tendency of similar teams to yield consistent betting results, and stochastic equivalence, where different teams exhibit indistinguishable patterns of Over/Under outcomes. A Bayesian formulation of the model allows for posterior inference on team-level latent traits and model parameters, while poste rior predictive checks are used to assess model fit. We further discuss the potential for such models to detect systematic biases in bookmaker lines, highlighting how latent structures in match-ups may inform profitable betting strategies under market inefficiencies. Simulated and real-world betting data are used to illustrate the model’s capabilities and limitations
Bacterial Chondronecrosis with Osteomyelitis in Broiler Chickens: Experimental Lameness and Additive Probiotic Treatments
Get PDFWith the global population already surpassing 8.2 billion and expected to reach 9.7 billion by 2050, the poultry industry has seen a surge in demand due to its unmatched efficiency and affordability for consumers across the globe. Selective breeding and quality nutrition developments since the industry\u27s commercialization have allowed producers to grow broilers up to 7 pounds by market age. While this extraordinarily efficient process has allowed quality poultry products to be available worldwide, the modern-day broiler has developed a multitude of musculoskeletal issues. Due to the lack of integral skeletal development to match the rapid production of muscle tissue, producers are experiencing an assortment of lameness issues. Bacterial chondronecrosis with osteomyelitis (BCO) is currently the most prevalent lameness disease in modern broilers. BCO accounts for the majority of mortality and culls related to lameness in the commercial broiler. This bacterial disease is associated with a combination of poor gut integrity (“leaky gut”), aerosolized bacteria, poor skeletal integrity, and mechanical stress on the long bones of the leg. Opportunistic bacteria such as Staphylococcus spp., Enterococcus spp., and Escherichia coli hematogenously spread from the small intestine to microfractures in the growth plates of weight-bearing bones. Bacterial colonization leads to infection, inflammation, necrosis of bone tissue, and eventual death. In addition to the economic loss associated with lameness, BCO is considered a significant animal welfare issue as birds experience extreme discomfort and are often unable to access food and water properly.
In Chapter One, I reviewed the literature utilized in developing my understanding of BCO. The overview presented was established and improved through my experience in co-writing a review publication on the topic, as presented in Chapter 2. Chapter Two presents a complete literature review of current publications relating to BCO. In addition to the foundational knowledge built by Dr. Wideman and Dr. Alrubaye, findings since Dr. Wideman’s 2016 review have revealed more aspects related to BCO etiology, which are presented here.
In Chapter Three, we tested the efficacy of using a supplemental probiotic program alongside a multivalent electron beam (eBeam) vaccine in reducing the incidence of BCO in broiler chickens. At hatch, birds received an Enterococcus faecium spray (E. faecium 669, at 2 × 109CFU/bird), and, from day 1 to day 56, drinking water was treated with a triple-strain Bacillus-based product (B. subtilis 597, B. subtilis 600, and B. amyloliquefaciens 516 at 1 × 109 CFU/bird/day). Chicks were divided into five treatment groups under an aerosol transmission challenge model to simulate treatment effects in a commercial setting. The treatment groups included a positive control group on a wire-floor pen (T1), a negative control group (T2), a group receiving only the probiotic program (T3), a group receiving only the multivalent vaccine (T4), and a group receiving both programs (probiotic supplementation and multivalent vaccination). Broilers were assessed daily for clinical lameness from day 22 until trial completion at day 56. The data collected presented significantly reduced lameness in T3, T4, and T5 when compared to T1 and T2
A Tale of Two Law Schools
Get PDFOn the august occasion of the 100th anniversary of the University of Arkansas School of Law, this Essay celebrates one of its singular achievements: the decision of then-Dean Robert Leflar to admit Silas Herbert Hunt, the first African American allowed to enroll for graduate or professional studies at any all-white university in the former Confederacy since reconstruction. The bravery of both Leflar and Hunt has been correctly celebrated in the past, but this Essay seeks to highlight why it was actually braver than one might think (for both Hunt and Leflar) by comparing the actions of Arkansas Law with the shameful and illegal actions of the University of Tennessee College of Law (an institution that I love enough to hold responsible for its past). My colleague Briana Rosenbaum has aptly described the University of Tennessee’s approach to desegregation as “[d]eflect, [d]elay, [and] [d]eny.
Energy Harvesting Devices and Sensors, and Methods of Making and Use Thereof
Get PDFDisclosed herein are energy harvesting devices and sensors, and methods of making and use thereof. The energy harvesting devices can comprise a membrane disposed on a substrate, wherein the membrane comprises a two-dimensional (2D) material and one or more ripples; and a component electrically, magnetically, electromagnetically, electrostatic/capacitively, piezoelectrically, magnetostrictively and/or mechanically coupled to the membrane and/or the substrate, such that the component is configured to harvest energy from the membrane. The sensors can comprise a membrane disposed on a substrate, wherein the membrane comprises a two-dimensional material one or more ripples; and a component electrically, magnetically, electromagnetically, electrostatic/capacitively, piezoelectrically, magnetostrictively and/or mechanically coupled to the membrane and/or the substrate, such that the component is configured to detect a signal from the membrane
Identifying Novel Molecular Targets to Induce Ferroptosis in Drug-Tolerant Cancer Cells Through Computational Modeling
Get PDFFerroptosis is an iron-dependent, reactive oxygen species (ROS)-driven form of regulated cell death in which the cell membrane is degraded by lipid peroxidation. It is regulated by multiple enzymes, such as glutathione peroxidase 4 (GPX4), which prevents membrane degradation by reducing lipid peroxides and protecting cells from oxidative damage. When inhibitors like RSL3 target GPX4, lipid peroxides build up, and toxic ROS compromises membrane integrity. Traditional anticancer treatments, such as most chemotherapies, aim to eliminate tumor cells by damaging DNA and triggering apoptosis. However, resistance to apoptosis is a “hallmark of cancer,” often resulting in treatment failure. As a distinct form of programmed cell death, ferroptosis offers an alternative to traditional genotoxic treatment strategies. In this project, a mechanistic model of the ferroptosis pathway is developed to gain insights into molecular drivers and identify novel targets for enhancing ferroptosis activation. The model is constructed in PySB, a Python-based modeling and simulation platform for complex biological systems. Using PyDREAM, a Bayesian parameter estimation tool, the model is calibrated to experimental dose-response data from two cancer cell lines exposed to the ferroptosis inducer erastin. Parameter distributions generated by PyDREAM are compared against each other and reveal that differences associated with System Xc⁻, the cystine-glutamate antiporter, explain disparate drug responses between the two cell lines, i.e., System Xc⁻ is a potential target for modifying sensitivity to ferroptosis in these cells. Future research will focus on performing similar analyses for additional cell lines and utilizing time-course data with absolute (rather than relative) molecular concentrations. The model will also be expanded to include additional molecular components and models of related processes, like mitochondrial metabolism, enhancing its predictive power
The Price of Profit: A Literature Review on Private Equity\u27s Impact on Patient Care and Healthcare Costs
Get PDFIn healthcare, private equity (PE) firms have rapidly expanded their presence across sectors, acquiring and consolidating providers. They typically operate on short investment cycles and employ strategies like heavy debt financing, roll-ups of fragmented practices, and aggressive cost-cutting to maximize returns. This expansion has sparked debate: supporters argue PE provides needed capital and efficiency to struggling providers, while critics contend that profit-driven ownership risks compromising care quality and access. This literature review synthesizes current evidence on how PE’s profit-driven approach affects patient care and healthcare costs. Overall, the findings suggest that PE ownership often raises costs—through higher prices and increased utilization—and can negatively impact care quality and patient outcomes. Case studies from nursing homes to hospitals reveal trade-offs such as reduced staffing, service cuts, and even increased mortality in some PE-owned facilities. At the same time, a few examples show that private capital can support expansion or innovation without harming care, indicating outcomes vary with management. The review highlights key policy implications, including the need for stronger regulatory oversight and transparency in ownership to mitigate negative effects. It also outlines areas for future research, such as understanding what practices can align PE investments with high-quality care. In sum, the thesis concludes that while PE brings new resources into healthcare, its pursuit of profit can come at a significant cost, warranting careful oversight and further study
Looking Back while Moving Forward: Four Musical Works that Signify Complex Emotions regarding the Passage of Time through Ambiguous Endings
Get PDFDefying expectations is a useful and overlooked tool in music composition. Despite all their differences, the final movement of Tchaikovsky’s 6th Symphony, Joe Hisaishi’s score to the 2001 film Spirited Away, Joni Mitchell’s popular song “Both Sides Now,” and electronic artist The Caretaker’s album set Everywhere at the End of Time all share similar programmatic content. Each presents a protagonist who is coming to terms with the passage of time and is conflicted about how they should cope with change. Upon examination of these four works, they all use unexpected and ambiguous endings to signify complex ideas about time through music. Using such techniques allows listeners to grasp each work’s message on a deeper level
Developing 3D-Printed Packaging to Protect Biodegradable Sensors used for Large-scale, Efficient Water Quality Monitoring
Get PDFFreshwater degradation due to human activities costs the United States over $2.2 billion annually, highlighting the urgent need for improved water quality monitoring methods. Traditional water sampling techniques are labor-intensive, time-consuming, and reliant on single-use plastics that contribute to environmental pollution. This research aims to address these issues by developing 3D-printed biodegradable sensor packaging for unmanned aerial vehicle (UAV)-assisted water sampling. By utilizing biodegradable materials, the research seeks to create an eco-friendly solution that ensures sensor durability while reducing negative environmental impact. The study will involve adjusting the packaging design to withstand UAV deployment by testing and improving the resistance of sensor packaging to water and other environmental factors and ensuring quick and safe degradation after use. 3D modeling using Shapr3D, 3D modeling software and the Prusa Slicer 2.9.0 app will guide the iterative design process. Rapid prototyping with Polyethylene Terephthalate Glycol (PETG) filament and will allow for iterative testing and refinement. The packaging prototypes will undergo rigorous testing, including drop tests and stability evaluations under various water conditions, to ensure their functionality and reliability. The final packaging design, fabricated with Butenediol Vinyl Alcohol Co-polymer (BVOH), is further evaluated for material solubility and environmental compatibility. This project aims to provide a cost-effective, sustainable approach to water quality monitoring by beginning the development of biodegradable sensor packaging to advance environmental protection efforts