Physical Sciences and Mathematics Commons^™

Investigating Liquid-Liquid Phase Separation In Lipid Bilayers: A Multi-Modal Approach Utilizing Spectroscopy, Microscopy, And Cryo-Em, Karan D. Sharma

Doctoral Dissertations

This thesis explores the characterization of liquid-liquid phase separation in model lipid bilayers using fluorescence, optical microscopy, and cryo-electron microscopy (cryo-EM) integrated with machine learning (ML) analysis. The plasma membrane has a complex composition, lateral heterogeneity and dynamic structure which makes it challenging to study. Simplified model membranes containing three or four-component lipid mixtures, typically comprising low- and high-melting lipids along with cholesterol, form phase separated systems that mimic lateral heterogeneity/lipid rafts in biomembranes. In living cells, lipid rafts are thought to form nanoscopic domains smaller than 200 nm. These domains cannot be resolved by conventional optical microscopy. For a …

Exploring The Integration Of Blockchain In Iot Use Cases: Challenges And Opportunities, Ivannah George

Electronic Theses, Projects, and Dissertations

Blockchain and The Internet of Things (IoT) is a significant paradigm which has gained traction in today’s digital age as two complimentary technologies. The combination of IoT's connectivity with blockchain's security creates new opportunities and solves problems associated with centralized systems. This culminating project aims to delve deeper into the integration of blockchain technology in IoT applications based on select use cases to uncover potential benefits and significant challenges of blockchain integration across different sectors. The research objectives to be addressed are: (RO1) How emerging vulnerabilities manifest in the implementation of blockchain within current IoT ecosystems. (RO2) How current opportunities …

Rapid Parameter Estimation Of Gravitational Wave Sources & Homologous Expansion In Common Envelope Events, Vinaya Valsan

Theses and Dissertations

Binary star systems are crucial for advancing our understanding of the universe. My doctoral research focuses on two related topics within the domain of binary star dynamics: gravitational waves from compact binary stars, and the evolution of the common envelope in stellar mass binaries.

In the era of multi-messenger astrophysics, swift identification and characterization of gravitational wave events is important for subsequent electromagnetic observations. The development of low-latency parameter estimation techniques is essential for providing astronomers with crucial information regarding the potential electromagnetic counterparts to gravitational wave signals. RapidPE is a highly parallelized parameter estimation scheme that achieves low-latency parameter …

Robust-Efficient Fitting Of Loss Models Via Quantile Least Squares, Mohammed Adjei Adjieteh

Theses and Dissertations

Actuaries and statisticians use statistical models to predict future losses for pricing and other purposes. However, a key challenge in modeling is estimating the unknown parameters that index these distributions. Ensuring both efficiency and robustness of the chosen method is crucial, especially given the prevalence of outliers or extreme losses in insurance claims data. The primary objective of this dissertation is to introduce a robust, efficient, and computationally easy parameter estimation method that can be applied to various loss modeling scenarios. The proposed method exploits the joint asymptotic normality of sample quantiles (of i.i.d. random variables) to construct both ordinary …

Novel Physics In Unconventional Superconductors, Adil Amin

Theses and Dissertations

In this work, we consider the interplay of different magnetic orders and superconductivity.We consider both phenomenological and microscopic models to capture these interactions. The models are built using group theoretic arguments to ensure the constraints provided by the crystal symmetry are satisfied. We first consider a phenomenological theory for two transitions in superfluid 3He which involves coupling superfluidity and spin fluctuations through an approach called spin fluctuation feedback effect. We then apply this phenomenological approach to UPt3, PrOs4Sb12 and U1−xThxBe13 to obtain a common underlying mechanism for two superconducting transitions. We then consider odd-parity multipolar antiferromagnetic order i.e. Kramers’ degenerate …

Enhancing Interactions Among Dipole Excitations Using Surface Plasmon Polaritons: Quantum Entanglement And Classical Interactions, Jay Berres

Theses and Dissertations

The interaction of light with matter at the nano-scale continues to be an important research area for the application of nano-optical devices in wide ranging areas such as biosensing, light harnessing, and optical communications, to name a few. An important aspect of this is the interaction among dipole excitations (which includes classical dipole emitters, and dipole approximations of atoms, molecules, and other quantum objects), mediated by the device medium where they are located. Since the dimensions of these devices, by design, are at the nano-scale, the size of the dipole-dipole interaction space is much less than the wavelength of light …

Mixdown Altitudes As A Method Of Forecasting Peak Wind Gusts Under High-Pressure Conditions, Danica Brezovar

Theses and Dissertations

Wind gusts are small-scale weather phenomena characterized by sudden, brief increases in wind speed (American Meteorological Society 2023), posing significant forecasting challenges due to their small spatial and temporal scales. These gusts are typically assumed to be caused by turbulent eddies circulating fast winds aloft down to the surface. Accurate forecasting of wind gusts is crucial across various sectors, including wind energy, structural engineering, and electric power distribution, where gusts can cause substantial economic impacts. Current forecasting methods either rely on the dynamical assumption that boundary layer turbulence mixes momentum down to the surface or predominantly statistical methods that typically …

High Temperature Alteration Conditions Within Lava Tubes: An Analogue For Venus Surface Geology, Dylan Alexander Childs

Theses and Dissertations

Scientific exploration of other planetary bodies comes with many limitations, and Venus is no exception. Average surface temperatures of ∼460°C and an atmospheric pressure of ∼96 bars has severely limited the longevity of any instruments sent to the surface of Venus. Furthermore, with an atmosphere composed of ∼96.5% CO2, there are only three wavelength windows in the near infrared region that can be used to measure the mineralogical composition of the surface. Due to these constraints, our understanding of Venus’ surface mineralogy is severely limited and to date direct measurements of its geologic composition are limited to a handful of …

Exponential Qubit Reduction In Optimization For Financial Transaction Settlement, Elias X. Huber, Benjamin Y. L. Tan, Paul Robert Griffin, Dimitris G. Angelakis

Research Collection School Of Computing and Information Systems

We extend the qubit-efficient encoding presented in (Tan et al. in Quantum 5:454, 2021) and apply it to instances of the financial transaction settlement problem constructed from data provided by a regulated financial exchange. Our methods are directly applicable to any QUBO problem with linear inequality constraints. Our extension of previously proposed methods consists of a simplification in varying the number of qubits used to encode correlations as well as a new class of variational circuits which incorporate symmetries thereby reducing sampling overhead, improving numerical stability and recovering the expression of the cost objective as a Hermitian observable. We also …

A Flood Of Consequences In Louisville, Kentucky: Using Hgis To Track Refugees Impacted By The 1937 Ohio River Flood, Trevor Harry

Masters Theses & Specialist Projects

The Ohio River flood of 1937 was the most devastating flood in the recorded history of the Ohio River Valley and is commonly referred to as the “Great Flood of 1937”. In January 1937, after nearly two months of continuous precipitation, over 60% of the city of Louisville, Kentucky, was flooded and at least 23,000 residents were displaced. The purpose of this research was to document, map, and compare the pre-flood residential locations, evacuation destinations, and post-flood residential locations of African American and White Louisville refugees from the 1937 Ohio River flood. Socioeconomic information from the manuscript versions of the …

The Role Of Efflux Pump Inhibitor In Enhancing Antimicrobial Efficiency Of Silver Nanoparticles And Methylene Blue As An Effective Photodynamic Therapy Agent, Yaran Allamyradov

Masters Theses & Specialist Projects

Efflux pumps are critical active transport systems utilized by cells to expel toxic substances, including antibiotics and photosensitizer complexes, thereby contributing to antimicrobial resistance. Efflux pump inhibitors (EPIs), which are compounds that obstruct the transport of molecules through these pumps, play a pivotal role in enhancing the effectiveness of antimicrobial therapies against pathogens. This study investigates the effects of the EPI reserpine on the photodeactivation rate of pathogens when used in conjunction with silver nanoparticles (Ag NPs) and methylene blue (MB), a common photosensitizer.

Our research reveals that the application of reserpine, in combination with Ag NPs and MB, leads …

Surface Patterning On Zirconia Dental Implants Via Laser-Induced Shockwave Imprinting, Inomjon Majidov

Masters Theses & Specialist Projects

Zirconia is rapidly becoming a preferred alternative to titanium in dental applications, primarily due to its aesthetic resemblance to natural teeth. This material’s tooth-like color avoids the aesthetic issues associated with the grey metal tint of titanium implants. Additionally, zirconia is hypoallergenic, making it an ideal choice for patients with metal sensitivities or allergies. Despite these advantages, zirconia generally exhibits lower biocompatibility and osseointegration compared to titanium implants. This study investigates laser-assisted, controlled imprinting technique on zirconia surfaces to enhance these properties. Our research used zirconia pellets, produced from powdered monoclinic zirconia pressed in a pellet press machine. Two methods …

Polygenetic Cave Sedimentation And Speleogenesis In The Mccloud Limestone Of Northern California, Niles Lathrop

Masters Theses & Specialist Projects

Caves in the Permian-aged, McCloud Limestone of the Klamath Mountains of Northern California preserve a diverse range of clastic sediments that represent broad-scale variations in paleo-hydrologic conditions and transport mechanisms that hint at varied modes of speleogenesis through local landscape development. Caves in the McCloud Limestone exhibit a range of cave passage geometries and arrangements that suggests periods of both hypogene and epigene cave development through temporal and spatial scales. This study evaluates the variability in the distribution, mineralogy, and transport mechanisms of clastic-cave sediments in seven hydrologically-distinct caves in the McCloud Limestone to establish relationships between clastic-cave sedimentation and …

Contaminant Transport Mechanisms And Source Tracking In Karst Groundwater Systems Under Agricultural Land Use, Shreya Pandey

Masters Theses & Specialist Projects

Karst areas in general face severe groundwater contamination problems that can degrade their water quality. In comparison to other landscapes, groundwater within karst regions is more susceptible to contamination. The situation gets worse when agriculture is practiced in these karst regions, because the nutrients and bacteria like nitrates and E. coli (Escherichia coli) are released into the groundwater systems which contaminate the water quality of those karst groundwater systems. This research aims to study the impacts of these contaminants, specifically nitrates and E. coli., by identifying the contaminant transport mechanisms and source tracking of these contaminants in the groundwater under …

Comprehensive Climate Vulnerability Assessment Of A Regional Karst Landscape For Hazard Mitigation Planning, Kara Brunot

Masters Theses & Specialist Projects

Climate change is the global phenomena affecting all sectors of society by creating conditions more conducive for the occurrence of extreme weather events. It is projected that the intensity and frequency of events will increase. Flooding, in particular, is projected to increase in frequency due to more intense precipitation events. Karst landscapes are especially vulnerable to climate change impacts because of their unique hydrology and geology. Karst flooding is most likely to occur from prolonged or intense rain events, which climate change will likely make more feasible. Areas are disproportionately affected by climate change due to population demographics and environmental …

Landuse And Microplastic Transport In Karst Groundwater Of South-Central Kentucky, Katie Norman

Masters Theses & Specialist Projects

Groundwater in karst areas is susceptible to contamination from various sources of pollution. Microplastics are a prevalent source of pollution entering groundwater. This study examines karst groundwater in three areas of investigation. One point of interest is an area that is impacted by urban activities, the Lost River Groundwater Basin, which includes water drainage from the City of Bowling Green, Kentucky. Another study location is Great Onyx (GO) Spring, which is a part of the Great Onyx Groundwater Basin located in Mammoth Cave National Park, Kentucky, and that is relatively unimpacted by urban activities. The third point of interest is …

Perceptions And Visual Awareness Of Urban Karst Flooding To Inform Preparedness Planning And Management Actions, Grace Hermann

Masters Theses & Specialist Projects

Awareness and perception of flooding can heavily affect how an individual or community prepares for flooding. Flood awareness can be affected by factors like past flood experience and demographics. Flood experience and demographics can affect flood awareness differently based on factors including the types and cause of flooding. Flooding in karst landscapes can vary from other types of flooding and neither perception nor awareness of karst flooding has been directly studied before. This study explored both expert and non-expert flood awareness and perception and flood policies in a karst landscape through interviews with experts, surveys, and cognitive mapping activities. The …

Catalytic Hydrogenation Of Co2 In Water And Ionic Liquids Using Platinum On Carbon, Kristin Collins

Masters Theses & Specialist Projects

Platinum-on-carbon (Pt/C) is a commercially-available catalyst that has been used in the literature to benchmark the performance of catalysts produced using platinum/cobalt alloy nanoparticles. Initially, we intended to build upon this example by synthesizing shape-controlled platinum/cobalt alloy nanoparticles in ionic liquids and compare their ability to catalyze the hydrogenation of CO₂ to methanol against Pt/C as a benchmark, with the idea that ionic liquids may improve catalysis. However, we found that Pt/C was unable to catalyze the hydrogenation of CO₂ to methanol. In an attempt to track the source of this discrepancy, Pt/C was characterized using thermogravimetric analysis …

Development And Application Of The Sinkhole Hazard Risk Index To Inform Karst Policy And Mitigation Planning, Meghan Puente

Masters Theses & Specialist Projects

Sinkholes are geologic hazards that occur in karst landscapes and can be highly destructive and costly. Sinkhole mitigation plans and development policies are nonexistent at the federal level within the United States and vary significantly at the state level. The lack of a unified standard for sinkhole mitigation planning is partly due to a lack of available data and resources needed to assess sinkhole risk. While there are established sinkhole assessments within the literature, they focus more on the detection and prediction of sinkholes rather than a holistic approach to risk assessment. The goal of this study is to create …

Evaluating Stormwater Erosion Prevention And Sediment Control Best Management Practices Using High-Resolution Rainfall Monitoring And Field-Based Assessment Tools, Brittany Pekara

Masters Theses & Specialist Projects

Advancing stormwater management methods and technology is critical as runoff from impermeable surfaces increases with urbanization and development. Stormwater runoff is highly susceptible to contamination from non-point source pollution and causing flood impacts following rain events, which varies spatially and temporally in an urban landscape. To counteract the impacts of contamination and drainage issues, Best Management Practices (BMPs) are implemented to reduce the effects of stormwater runoff; however, the unpredictable nature of storm events can make methods for effectively monitoring impacts difficult in trying to capture first flush inputs, flood threats, and sedimentation sources. This research utilizes a highresolution rainfall …

How Can Event Attribution Science Underpin Financial Decisions On Loss And Damage?, Dim Coumou, Paola A. Arias, Ana Bastos, Charlotte Kendra Z. Gotangco Gonzales, Gabriele C. Hegerl, Pandora Hope, Christopher Jack, Friederike Otto, Fahad Saeed, Olivia Serdeczny, Theodore G. Shepherd, Robert Vautard

Environmental Science Faculty Publications

With climate extremes hitting nations across the globe, disproportionately burdening vulnerable developing countries, the prompt operation of the Loss and Damage fund is of paramount importance. As decisions on resource disbursement at the international level, and investment strategies at the national level, loom, the climate science community’s role in providing fair and effective evidence is crucial. Attribution science can provide useful information for decision makers, but both ethical implications and deep uncertainty cannot be ignored. Considering these aspects, we articulate a vision that integrates established attribution methods and multiple lines of evidence within a coherent logical framework.

Bridging The Gap: Ai And The Hidden Structure Of Consciousness, Emily Barnes, James Hutson

Faculty Scholarship

The quest to develop Artificial Intelligence (AI) systems that possess human-like consciousness necessitates a deep dive into both theoretical and practical aspects underpinning this ambitious goal. This article builds on initial philosophical explorations of AI consciousness by examining the intricate and often hidden structures that may facilitate conscious experiences in AI. Drawing from concepts in cognitive science and neuroscience, the article elucidates how AI systems can be designed to replicate the structural and functional aspects of human consciousness. The discussion includes the Hierarchy of Spatial Belongings proposed by Forti (2024), frameworks like the Integrated Information Theory (IIT), and models linking …

Iowa Waste Reduction Center Newsletter, August 2024, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

In this issue:

--- Join Our Team
--- Fraud Alert: New phishing scam targeting businesses
--- ICAW 2025 Poster Contest
--- STAR4D returns to the Iowa State Fair

Artificial Intelligence, Work, And The Future Of Education, Daniel Brown

Presentations

No abstract provided.

Nonfactoid Question Answering As Query-Focused Summarization With Graph-Enhanced Multihop Inference, Yang Deng, Wenxuan Zhang, Weiwen Xu, Ying Shen, Wai Lam

Research Collection School Of Computing and Information Systems

Nonfactoid question answering (QA) is one of the most extensive yet challenging applications and research areas in natural language processing (NLP). Existing methods fall short of handling the long-distance and complex semantic relations between the question and the document sentences. In this work, we propose a novel query-focused summarization method, namely a graph-enhanced multihop query-focused summarizer (GMQS), to tackle the nonfactoid QA problem. Specifically, we leverage graph-enhanced reasoning techniques to elaborate the multihop inference process in nonfactoid QA. Three types of graphs with different semantic relations, namely semantic relevance, topical coherence, and coreference linking, are constructed for explicitly capturing the …

Causvsr: Causality Inspired Visual Sentiment Recognition, Xinyue Zhang, Zhaoxia Wang, Hailing Wang, Jing Xiang, Chunwei Wu, Guitao Cao

Research Collection School Of Computing and Information Systems

Visual Sentiment Recognition (VSR) is an evolving field that aims to detect emotional tendencieswithin visual content. Despite its growing significance, detecting emotions depicted in visual content,such as images, faces challenges, notably the emergence of misleading or spurious correlationsof the contextual information. In response to these challenges, we propose a causality inspired VSRapproach, called CausVSR. CausVSR is rooted in the fundamental principles of Emotional Causalitytheory, mimicking the human process from receiving emotional stimuli to deriving emotional states.CausVSR takes a deliberate stride toward conquering the VSR challenges. It harnesses the power of astructural causal model, intricately designed to encapsulate the dynamic causal …

Clamber: A Benchmark Of Identifying And Clarifying Ambiguous Information Needs In Large Language Models, Tong Zhang, Peixin Qin, Yang Deng, Chen Huang, Wenqiang Lei, Junhong Liu, Dingnan Jin, Hongru Liang, Tat-Seng Chua

Research Collection School Of Computing and Information Systems

Large language models (LLMs) are increasingly used to meet user information needs, but their effectiveness in dealing with user queries that contain various types of ambiguity remains unknown, ultimately risking user trust and satisfaction. To this end, we introduce CLAMBER, a benchmark for evaluating LLMs using a well-organized taxonomy. Building upon the taxonomy, we construct 12K high-quality data to assess the strengths, weaknesses, and potential risks of various off-the-shelf LLMs.Our findings indicate the limited practical utility of current LLMs in identifying and clarifying ambiguous user queries, even enhanced by chain-of-thought (CoT) and few-shot prompting. These techniques may result in overconfidence …

Neural Network Semantic Backdoor Detection And Mitigation: A Causality-Based Approach, Bing Sun, Jun Sun, Wayne Koh, Jie Shi

Research Collection School Of Computing and Information Systems

Different from ordinary backdoors in neural networks which are introduced with artificial triggers (e.g., certain specific patch) and/or by tampering the samples, semantic backdoors are introduced by simply manipulating the semantic, e.g., by labeling green cars as frogs in the training set. By focusing on samples with rare semantic features (such as green cars), the accuracy of the model is often minimally affected. Since the attacker is not required to modify the input sample during training nor inference time, semantic backdoors are challenging to detect and remove. Existing backdoor detection and mitigation techniques are shown to be ineffective with respect …

Beyond Automation: Ai As A Catalyst For New Job Creation In Software Development, Jill Willard, James Hutson

Faculty Scholarship

As artificial intelligence (AI) continues to evolve, its impact on software development and programming is profound, drawing parallels to the shift from assembler to object-oriented programming. This article explores how AI is reshaping the landscape of software jobs, creating new opportunities rather than diminishing them. By simplifying complex tasks and lowering barriers to coding, AI is expanding the technology "pie," introducing new use cases, and enhancing efficiency. The transition from monolithic services to microservices has reduced risks and accelerated deployment processes, and AI is poised to further this evolution by managing the complexities of service interactions through advanced orchestration layers. …

Palynostratigraphy And Bayesian Age Stratigraphic Model Of New Ca-Id-Tims Zircon Ages From The Walloon Coal Measures, Surat Basin, Australia, K. Sobczak, J. Cooling, T. Crossingham, H. G. Holl, M. Reilly, J. Esterle, J. L. Crowley, C. Hannaford, M. T. Mohr, Z. Hamerli, S. Hurter

Geosciences Faculty Publications and Presentations

The Surat Basin hosts significant coal and coal seam gas resources. New high-precision CA-TIMS U/Pb zircon ages from tuffs and Bayesian age stratigraphic models are combined with palynology from fine-grained sedimentary rocks and zircon trace elements to provide further chronostratigraphic and biostratigraphic constrains on the Walloon Coal Measures in the eastern margin of the Surat Basin and infer the palaeoenvironment and tectonic setting. The tuff ages range from 165.88 ± 0.11 Ma to 158.84 ± 0.05 Ma, with those from the stratigraphically lower Taroom Coal Measures ranging from 165.88 ± 0.11 to 163.05 ± 0.08 Ma and Juandah Coal Measures …