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Understanding Privacy and Security Implications of Emerging ASR Devices
Get PDFThe number of devices that use voice assistants has increased dramatically worldwide, reaching 4.2 billion in 2022 and is predicted to reach 8.4 billion by 2024. Voice assistants can interact with users through voice, perform specific tasks, and gradually learn and adapt to the user's habits. However, as voice assistants have grown in popularity, user privacy and security issues have become increasingly prominent. Topics such as misrecognition, potential eavesdropping, and waking up with hidden commands have attracted public attention. In this thesis, we propose an innovative method, SpyLoc, to locate widely used spying Automatic Speech Recognition (ASR) devices (e.g., Amazon Alexa, Apple Siri, and Google Assistant) to mitigate the potential surveillance risk. SpyLoc uses Text-to-Speech (TTS) to generate wake words, and plays them at different positions with varying volumes to trigger the target hidden ASR. By analyzing the resultant wireless traffic generated by the ASR, we calculate the corresponding distances between the wake word player and the ASR. With spatial analysis, we can further pinpoint the location of the ASR. Our extensive real-world experiments using the developed application and three commercial off-the-shelf voice assistants show that SpyLoc can achieve low localization error with a short processing time (i.e., several minutes). This method presents an innovative approach to addressing the potential eavesdropping risks posed by ubiquitous voice assistants
Nanopore Direct RNA Sequencing and Proteomics Reveals Virus-induced Changes in Human Cells
Get PDFInfluenza virus remains a pervasive global health threat due to its rapid mutation and immune evasion capabilities, resulting in frequent epidemics and sporadic pandemics. This thesis investigates the influence of N6-methyladenosine (m6A) RNA modifications on host-pathogen interactions during influenza infection, emphasizing their role in regulating gene expression and host cellular processes. Leveraging nanopore direct RNA sequencing and proteomic analyses, this study offers a comprehensive view of the epitranscriptomic changes in influenza-infected human cells.The research explores the global distribution of m6A modifications across host and viral RNA, focusing on their effects on RNA stability, splicing, and translation. Through proteomics integration, we assess how these epitranscriptomic modifications influence protein expression and cellular function, elucidating the contribution of m6A modifications and m6A-binding proteins to immune response regulation and viral replication control. The study identifies a dynamic role for influenza-induced m6A modifications, which can both support antiviral signaling and, conversely, facilitate viral replication. This dual functionality reveals an intricate balancing act between viral manipulation of host pathways and host adaptive responses aimed at containment. Key findings underscore that influenza infection triggers specific m6A modifications, enhancing the stability and translation of immune-related transcripts, thereby bolstering antiviral defenses. Additionally, a conserved m6A consensus motif (GGACU) was observed, indicating a stable targeting mechanism for m6A methylation across host and viral RNA, a feature maintained even under infection-induced stress. This conservation suggests that while infection modulates m6A distribution and intensity, it does not disrupt its fundamental targeting, allowing m6A regulation of host defenses to persist. The research highlights the therapeutic potential of targeting m6A modifications, suggesting that precision interventions within this pathway could provide new strategies for antiviral therapies. By mapping the roles of m6A in virus-host interactions, this study contributes to the broader understanding of epitranscriptomic regulation in viral infections, with implications for developing antiviral therapies that harness RNA modification pathways
“I Phub You Because…”: Testing a Theory of Interpersonal Behavior for Understanding and Predicting Phubbing
Get PDFPhubbing (i.e., phone and snubbing) is toxic to most individuals. Unlike their perceptions that it is rude, they still phub others. With the prevalence of such behavior in the current age of high technology, it is necessary to understand what motivates people to phub others and examine whether people phub others consciously or unconsciously. The current study examined these questions based on Triandis’s theory of interpersonal behavior (TIB). First, this study developed and validated a self-report measure of phubbing and its predictors based on TIB. 102 items in total across the ten scales – phubbing, outcome beliefs, outcome evaluations, norms, social roles, self-concepts, affect, habits, facilitating conditions, and intentions – were initially developed in Study 1 (n = 349) through extensive literature reviews and screenings by four subject-matter experts. The results of exploratory factor analysis (EFA) reduced items to 72, showing low loadings and cross-loaded items. With newly collected data (n = 811), Study 2a evaluated and confirmed the retained items and dimensions from Study 1 through confirmatory factor analysis (CFA). The CFA results, which led to 55 items being retained, suggested that the developed scales were valid and reliable. Structural equation modeling (SEM) was conducted using those scales to test proposed hypotheses suggested by TIB in Study 2b. The results revealed that TIB was an effective framework for explaining why people phub others. Also, results indicated that attitudinal, social, and emotional factors were significantly associated with phubbing intentions. These phubbing intentions, habits, and facilitating conditions were significantly related to phubbing behavior. In all, the findings of this dissertation contribute to the understanding of phubbing behavior. This study also advances theoretical, methodological, and practical knowledge about phubbing
CHARACTERIZATION OF TWO BACTERIAL ISOLATES, ACHROMOBACTER MUCICOLENS (A2) AND BACILLUS PARAMYCOIDES (A17), AND ANALYSIS OF PLASTIC BIODEGRADATION CAPABILITY
No full textIn this work, two isolates, Achromobacter mucicolens (A2) and Bacillus paramycoides (A17), isolated from naturally weathered plastic enrichment cultures, were studied genetically, morphologically, biochemically and for plastic biodegradation capability. Characterization studies revealed a Gram-variable, rod-shaped A2 strain, with growth ranges of pH 5-9, 30-37°C, salt tolerance of 1-8%, and produced circular, crateriform, smooth, mucoid, and transparent punctiform colonies with entire margins. Strain A2 showed the ability to utilize few carbon substrates, could grow in the presence of multiple antibiotics and chemical inhibitors, and showed evidence of swimming motility in 0.03% semisolid agar down to 4°C, as well as the ability to form biofilms on polystyrene. The Bacillus species was revealed to be Gram-positive and rod-shaped, with growth ranges of pH 4-9, 22.5-48°C, salt tolerance of 1-8%, and produced circular, crateriform, smooth, wrinkled, and pigmented milky colonies with entire margins. Strain A17 showed the ability to utilize many carbohydrate substrates and showed less resistance to chemical sensitivity assays than A2.
Genetic enzymatic potential for the ability to complete the plastic biodegradation pathways of polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) was assessed for both isolates. Both strains showed enzymatic potential to complete the degradation process for PE, PP and PVC from polymer to polyhydroxyalkanoate (PHA). A 45-day biodegradation experiment of PE, PP, and PVC with pure cultures and a co-culture treatment showed successful biodegradation of all three plastics, with the best degradation being of PE, followed by PP, and the least degradation of PVC. As the molecular structure of the polymers contain additional components (PE being the simplest with just a hydrocarbon backbone, then PP with an additional methyl group, and PVC having the most components with an additional chlorine group) all treatments showed a decrease in degradation efficiency. This data supported the hypothesis that with additional components to the polymer structure the biodegradation will be more difficult.
The plastic biodegradation study showed more plastic weight loss by strain A2 than strain A17, and the co-culture treatments consistently showed more weight loss than strain A17 as well as more weight loss of PE than both pure cultures. Additionally, A17 showed a decrease in weight loss that was significantly larger than the decrease of the A2 as the plastic polymers contained additional components. FTIR analysis showed significant differences in functional group changes of PP and PVC plastics, while PE had nearly identical FTIR peak patterns between the treatments and the control. This could be due to the strains surpassing the oxidation step, which is the most energetically taxing step of the biodegradation pathway, or due to functional group changes not being evident in every plastic particle. The GC chromatogram data provided insight to which strain was the largest contributor to the plastic biodegradation in the co-culture treatments. The co-culture PE GC chromatogram was the most similar to A17’s PE GC chromatogram, indicating A17 was most likely the larger contributor to the degradation in the co-culture. However, the co-culture GC chromatograms of PP and PVC were both more similar to strain A2’s GC chromatograms, indicating A2 was most likely the larger contributor to the degradation of PP and PVC in the co-culture treatments. This followed the trend of the weight loss, as A17 showed a large decrease in weight loss of PP and PVC.
Overall, A2 showed a better potential for plastic biodegradation application than A17, with the ability to form biofilms on a plastic surface, a limited ability for carbon substrate utilization, chemical resistance to many chemical stressors, and a higher rate of plastic biodegradation regardless of plastic polymer structures of PE, PP and PVC
State of Health Estimation in Lithium-ion Batteries Using Experimental and Model Driven Approaches
Get PDFMeeting the demand for clean, renewable energy in the future will require the use of batteries to meet power demand at times of low supply. Having batteries with a large enough capacity and power output to meet this requirement is imperative, prompting the need for research into estimating the state of health of batteries. This thesis takes two approaches to state of health monitoring: experimental and model driven.
The experimental approach consisted of taking displacement measurements of an LMN-8790140-1C pouch cell using 3D DIC technology. It was determined that there is a strong linear relationship between the displacement of a completely discharged battery and the battery’s state of health. It was also determined that there is a potential relationship between displacement, voltage, and state of health. More work needs to be done to verify this relationship. The points that best represented the average displacement were in the middle of the cell or closer to the long sides.
The model driven approach consisted of creating an equivalent hydraulic model to simulate a silicon-graphite composite anode battery. An LG-MJ1 18650 cell was cycled to collect current and voltage data at several different state of health stages. The particle swarm algorithm in MATLAB was used to identify key parameters of the model. Using identified parameters, the model could accurately simulate voltage given a simple current input. The model struggled with simulating a UDDS cycle, but that could be due to poor parameter identification. A relationship was identified between the diffusive time constant of silicon and state of health. More work needs to be done to determine if other state of health indicating parameters, like estimated resistance or the diffusive time constant of the cathode or graphite, can be used in composite anode batteries.
KEYWORDS: State of Health Estimation, GOM Aramis, DIC, Equivalent Hydraulic Model, Composite Anode Batterie
Synthetic chondroinductive biomaterial for hyaline cartilage regeneration
Get PDFAvascularity, low cell count, and low proliferative potential constitute the triad that defines the limited self-regenerative potential of articular cartilage. Consequently, the repair of articular cartilage defects presents a highly challenging task for researchers and orthopedic surgeons. Despite the progress in currently available treatments, including surgical and regenerative cell therapy techniques, the regeneration of a tissue that completely mimics the biochemical and mechanical properties of articular cartilage has not yet been successful.
Among a multitude of approaches being investigated to induce hyaline cartilage regeneration, the design of an acellular chondroinductive biomaterial would provide a safe, cost-effective, and translational approach toward successful true hyaline cartilage regeneration.
In this dissertation, the objective was to design a chondroinductive hydrogel to induce the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). The base of the biomaterial was a pentenoate-functionalized hyaluronic acid (PHA) hydrogel along with a conjugated chondroinductive factor.
The search for a chondroinductive factor started with the evaluation of two peptides and two small compounds from the literature with human and equine BMSCs; however, no evidence of chondroinduction was observed with any of the peptides or compounds. The search continued with the evaluation of the chondroinductive potential of 11 newly discovered peptides with no success. Hence, and as a contingency plan, I resorted to the use of a peptide (Peptide D), based on preliminary results (from others on our team) with hBMSC spheroid cultures, which suggested that Peptide D could enhance the chondrogenic differentiation of hBMSCs in the presence of transforming growth factor (TGF)-β3. Therefore, the final objective of this dissertation was to synthesize a PHA hydrogel with conjugated Peptide D and conjugated TGF-β3. Varying concentrations of Peptide D and TGF-β3 were evaluated, and I identified a combination that resulted in the upregulation in the gene expression of collagen II and SOX-9 compared to hydrogels with conjugated TGF-β. This outcome signifies the successful synthesis of a promising chondroinductive biomaterial.
The results obtained in this dissertation were the basis to select promising hydrogel groups to evaluate in a currently ongoing in vivo cartilage regeneration study in rabbits. Future work beyond this thesis will focus on advancing the hydrogel-peptide-TGF-β3 system based on the outcome of the current in vivo study, and to refine the sequence of Peptide D in efforts to enhance its chondroinductive potential
Zr-MOFs for Hydrolysis Reactions: Computational Evaluation of Interactions, Kinetics, and Molecular Accessibility
No full textMetal-organic frameworks (MOFs) are a class of porous crystalline solids that present as promising instruments for the removal of chemical warfare agents (CWAs). Owing to their remarkable porosities and large surface areas, MOFs possess superior adsorption, reactivity, and catalytic abilities, providing an ideal environment for target species capture and decomposition. The tunable networks of MOFs also allow for customization of their chemical functionalities, making them practicable in personal protective equipment and adjustable to dynamic environments.
While progress has been made in the tailoring of MOF-based materials for toxic chemical degradation applications, issues of small pore apertures and poor water stability have hindered their practicality. Recent breakthroughs have shown that zirconium-based MOFs have the highest potential among different MOFs for hydrolytic and oxidative degradation of CWAs; however, it remains unclear what combination of features enables efficient breakdown in the solid phase and under realistic environmental conditions of humidity. Furthermore, many puzzles still exist regarding how those features may change with respect to the specific toxic chemical and the mechanism of detoxification. Characterizing structure-property relationships of different Zr-MOFs with various CWAs in the presence of atmospheric moisture is essential to establishing design rules that will lead to effective degradation under relevant field conditions.
This dissertation focuses on the use of computational modeling to gain insight into the role of structure and topology in the molecular accessibility, mass transport, kinetics, and adsorption of water, nerve agents, and their simulants in Zr-based MOFs. With combined molecular dynamics (MD) and density functional theory (DFT) approaches, the effects of pore size, connectivity, and hydrophobicity/hydrophilicity on adsorbed species distribution, binding, residence time, and diffusion in Zr-MOFs are explored. In the first section, we provide a comprehensive overview of intrinsic catalytic reaction mechanisms in MOFs, the design of efficient degradation strategies in the aqueous and solid phases, and the tuning and functionalization of MOFs to enhance CWA removal under realistic battlefield conditions. In the second section, we utilize a combination of equilibrium and non-equilibrium MD simulations to investigate the transport diffusion properties of water in two main classes of Zr-MOFs. In the third section, we propose a combination of MOF design rules that lead to promising performance characteristics for hydrolysis operations in conditions of varying humidity, supported by MD simulations. We also we develop a code for calculating the radial distribution function of adsorbed molecules in nonuniform systems. In the fourth section, we use MD and DFT approaches to evaluate whether those design rules remain relevant for degradation of different types of nerve agents, both by themselves and in the presence of water. We also investigate whether reaction sites and mechanisms are likely to remain the same for all nerve agents in all Zr-MOFs. The results of this dissertation contribute to the advancement of MOF-based strategies for the destruction of CWAs and highlight the potential of these materials to address the challenges associated with chemical warfare
To Be a Better Teacher: A Critical Self-Reflection
Get PDFIn this paper, I aimed to answer the following questions in order to find potential avenues of improving my present conditions as a teacher: What does it mean to be a teacher? What will it take to be a better teacher? I utilized critical reflections of my teaching experience thus far to analyze and interpret the sense of dread that I have come to associate with being a teacher. First, I aimed to uncover the source of this dread and investigate how it is perpetuated. Then, I juxtaposed my K-12 education experience with my college experience to identify the lack of community in K-12 schools as a reason as to why the dehumanization of students and teachers has become normalized in our society. I make the case for democratic education as a potential response to the dehumanizing education currently found in schools. Finally, I use theories from John Dewey and Paulo Freire to look into my future in the profession as a more democratic educator
Navigating the Arts
No full textNavigating the Arts delves into the visual elements and principles of design throughout art history and is tailored for classroom use. It aims to deepen students’ understanding of these concepts and their application across different artistic forms, fostering critical thinking and visual literacy. The accessible language, logical structure, clear objectives, and wealth of examples and images make this journal an ideal tool for everyone interested in developing class discussions on how to understand and interpret images. The work is licensed under a Creative Commons Attribution-NonCommercial-4.0 International License.Navigating the Arts was made possible through the generous support of an Alternative Textbook Grant provided by the
University of Oklahoma Libraries
The decision to trust: an application of structural equation modeling to the actor evaluation and trust framework
Get PDFThe growing number of crises, from public health crises like COVID-19 to natural disasters like wildfires and hurricanes, has exposed the need for a comprehensive framework to understand how an individual decides who to trust and whether to cooperate with public policy to mitigate risk. Previous research has relied on contemporary social trust and confidence conceptualizations to develop complex models and frameworks with limited generalizability and applications. Further, many contemporary trust and policy cooperation frameworks lack robust empirical tests and evidence to support their claims and assumptions. This study introduces the Actor Evaluation and Trust Framework (AETF) and tests it using nationally representative survey data from the COVID-19 pandemic. Results from three structural equation models provide significant support for the AETF. The AETF offers a novel approach to understanding trust and policy cooperation, building on interdisciplinary research and insights from contemporary models