Search Results

Development and Characterization of Compliant Bioelectronic Devices for Gastrointestinal Stimulation
In this research, we aimed to develop thin-film devices on a polymer substrate and an alternative 3D-printed device with macroelectrodes for treating gastrointestinal (GI) conditions. First, the fabrication of thin-film devices was demonstrated on a softening thiol-ene/acrylate polymer utilizing titanium nitride (TiN) as electrode material. This was achieved by utilizing cleanroom fabrication processes such as photolithography, wet and dry etching. The functionality of the device was shown by performing electrochemical characterization tests, mainly cyclic voltammetry, electrochemical impedance spectroscopy, and voltage transient. We synthesized a novel thiol-ene/acrylate polymer based on 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO), trimethylolpropanetris (3-mercaptopropionate) (TMTMP), and polyethylene glycol diacrylate (PEGDA). We show that this stretchable shape memory polymer substrate is well suited for cleanroom processes. Finally, for the high throughput of the wearable devices with electrodes size 10 mm in diameter, we implemented single electrode fabrication using printed circuit boards (PCBs) and depositing gold (Au) and TiN on the plated side of PCBs utilizing the sputtering tool. This step was followed by the assembly of those single electrodes on the flexible 3D printed device. We showed that the TiN electrode material performed better in terms of charge storage capacity and charge injection capacity than the widely used stainless steel electrode material for wearables.
Development and Preliminary Validation of the Comprehensive Trauma and Stressors Checklist
To assess a wide range of stressors and traumas, we developed a trauma and stressors exposure checklist for adults to capture a wide variety of potential trauma exposure. This study details the extensive development and validation process of the Comprehensive Trauma and Stressors Checklist (CTSC). Study 1 consisted of item pool generation, review of existing trauma measures, content analysis, and expert review and input. Study 2 analyzed reliability and validity of the updated checklist. Participants were recruited from college and community samples (N = 200) and completed the CTSC along with five additional measures. The CTSC demonstrated high internal consistency (α =.96). Good temporal stability was established with a subset of participants (n = 28) who completed the survey twice for test-retest reliability (r = 0.86, p < .001). Significant correlations between scores on the CTSC and the Stressful Life Events Screening Questionnaire, Life Events Checklist for the DSM-5, Intersectional Discrimination Index, and Spiritual Abuse Questionnaire are evidence of strong convergent validity. Finally, the lack of significant correlations between CTSC scores and theoretically unrelated constructs supported the discriminant validity of the CTSC. This study provides preliminary evidence that the CTSC is a reliable and valid measure of exposure to traumas and stressors. Future studies with the CTSC will examine measurement invariance, exploratory and confirmatory factor analysis, and reading level.
Directing Transition Metal Catalysis of Second and Third Row Metals through Ligand Design
Ligand design is important due to a ligand's ability to tune properties of the transition metals, such as catalytic activity and selectivity. Gold(I) catalysts can be directly impacted by ligands electronically as well as with steric bulk when undergoing enantioselective and regioselective reactions. In the dissertation, a series of gold(I) acyclic diaminocarbenes were synthesized and used to explore the 1,6 enyne cyclization/hydroarylation. The use of metal templated synthesis of the gold(I) acyclic diaminocarbenes allowed for the gradual increase in steric bulk of the catalysts. In the end, it was shown that electronics play the major role in the regioselectivity for the 1,6 enyne cyclization/hydroarylation but localized steric bulk can control the catalytic reaction if placed strategically. Cross-coupling reactions used to form carbon-carbon or carbon-heteroatom bonds are important in the production of pharmaceutical chemicals on a large scale. Iron, an extremely cheap and earth abundant first row transition metal, has had some success in cross-coupling reactions. Iron does not go through the same catalytic cycle for cross-coupling as most transition metals, the most common of which is palladium. In the dissertation, a ligand was developed to induce Iron to undergo the same cycle as palladium. In addition, the same ligand was placed on palladium(II) and reduced to try to form and isolate a catalytically active palladium(0) complex.
The Effect of Developmental Hypoxia on Cardiac Physiology in Three Species: Alligator mississippiensis, Chelydra serpentina, and Danio rerio
In this dissertation, I explored the effects of developmental hypoxia on heart contractility in three separate species of ectotherms: the common snapping turtle (Chelydra serpentina), the American alligator (Alligator mississippiensis), and the zebrafish (Danio rerio). I began with the common snapping turtle and tested whether the utilization of the sarcoplasmic reticulum was altered in response to developmental hypoxia. In the next two chapters, developmental hypoxia of the American alligator was explored studying how the cardiac tissue was affected, specifically in physiological stressors, sarcoplasmic reticulum utilization and sensitivity to pharmacological increases in contractility. The last chapter explored how zebrafish heart contractility was altered in response to chronic hypoxia from egg to adult. Findings from these chapters suggest that while developmental hypoxia did alter cardiac contractility, it did not alter the response of the heart to physiological stressors such as increased heart rate or under hypoxia. Overall, these findings contribute to increasing the current understanding of how developmental hypoxia alters the cardiovascular system but with an emphasis on the cardiac tissue level.
The Effect of Restructuring of Peer Firms on Investment
Firms' operational restructuring involves information relevant to strategic choices as well as future demand and cost conditions. This study examines the relationship between peer firms' restructuring and a company's responsiveness to its growth opportunities. Peer firm restructuring can increase uncertainty with respect to a company's payoffs regarding its investment projects, leading to decreased responsiveness to growth opportunities. Using a large sample of public companies during 2006–2020, I find that peer firms' restructuring is negatively associated with the responsiveness of capital expenditures (Capex) to growth opportunities. The results suggest that peer firms' restructuring activities provide information about a company's investment projects above and beyond industry shocks reflected in changes in industry sales. Furthermore, these associations are moderated by industry competition. The negative effects of peer firms' restructuring on Capex sensitivity are the strongest in high-competition industries.
Effects of Impaired Verbal Abilities on Miranda Comprehension and Reasoning: "Do You Understand Your Rights?"
In Miranda v. Arizona (1966), the Supreme Court of the United States required that custodial arrestees be informed of their constitutional and continuous rights to silence and to legal counsel. Moreover, the ruling mandated that waivers be considered valid only if they were made knowingly, intelligently, and voluntarily. However, in the decades that followed, evidence from both caselaw and empirical scholarship clarified that, for many vulnerable populations, these rights are in jeopardy. Among these vulnerable populations, those with limited cognitive capacities (LCCs) have been functionally excluded from research which primarily focused on persons with intellectual disabilities. This thesis offers a novel exploration of the role of specific cognitive impairments on Miranda comprehension and reasoning, with a focus on verbal intelligence (VIQ). Using a large archival sample of pretrial defendants (N = 820), current results suggest that defendants struggled with Miranda abilities regardless of other, individual characteristics. However, verbal intelligence emerged as a very strong predictor of Miranda comprehension such that those with lower VIQ were considerably more vulnerable to impaired comprehension. More so, data suggest that several compounded vulnerabilities (i.e., minoritized racial/ethnic identity status, limited academic achievement, illiteracy) are essential to understanding the extent of vulnerability in the criminal legal system in addition to the negative impacts of cognitive impairments. Several crucial implications for clinical practice and legal decision-making are explored. Finally, essential areas for future research are presented.
The Effects of Implementing a Reward-Based Version of Ostrom's Eight Design Principles as an Intervention Package on Responses in a Common Pool Resource (CPR) Game
The aim of behavior analysis has always been to apply technologies rooted in basic behavioral principles to problems of societal importance (e.g., Skinner, 1948; 1953; 1987). One such problem is the Tragedy of the Commons - a phenomenon arising from systemic failures among a community, leading to the total collapse of a critical resource (Hardin, 1968). Elinor Ostrom's Eight Design Principles were developed to provide a framework for the self-management of common pool resources (CPRs; Ostrom, 1990/2015). When applied as an independently manipulated variable, Ostrom's design principles have shown strong effects in the management of CPRs within the context of a tabletop board game Catan® (Smith & Becker, 2023). This preparation included both rewards (i.e., positive reinforcement) and sanctions (i.e., positive punishment) as a feature of the independent variable. However, it has been well documented that punishing and coercive contingencies can lead to problematic outcomes for individuals and societies (e.g., Sidman, 2001; Skinner, 1976). This study evaluated the effects of utilizing only rewarding consequences in lieu of sanctions in an effort to produce the previously observed control over self-management of a CPR, utilizing the previously adapted rules of the Catan® board game.
The Effects of Specific and Disguised Mands on Staff's Reinforcer Delivery
Residential facilities for adults with developmental disabilities offer essential accommodations and support services, with fostering communication for residents as an important aspect of care. Despite the importance of communication, previous research has identified concerns about staff performance (SP) in facilitating positive social interactions, such as engaging in consequent-mediating behavior for residents' mands. Previous research has primarily focused on improving SP through skills-based training. Yet, Skinner's theory of verbal behavior emphasizes the social and reciprocal nature of mands. Skinner suggests that the listener's behavior, engaging in consequence-mediating behavior, must be conditioned by the verbal community. However, empirical investigations into the reinforcing practices of staff in residential facilities, such as the shaping and sustaining of different types of resident mands, is limited. The current investigation sought to address this gap in research by evaluating if distinct mand topographies, disguised or specific mands, influenced the likelihood of staff engaging in consequence-mediated behavior across three staff-resident dyads. Results suggest a low probability of staff responding to, or reinforcing, mands, thus limiting conclusions on the effects of mand topographies on staff performance. Future directions and considerations regarding resident-staff interactions are discussed.
The Emergence of Arab Nation-State Nationalism as an Alternative to the Supranational Concept of Ummah
In this dissertation, I examine the political shift or reorientation of Arabs and Muslims from the supranational Ummah to the Western form of nation-state by attending to modern Arabic novel in the period between World War I and World War II. I explore the emergence of secularism in Arab national formation. One of my central arguments is that Arab nationalism is indeed a misleading phrase as it gives the impression of unity and coherence to a complex phenomenon that materialize in a number of trends as a form of struggle. In the first chapter, I defined the scope of my argument and the underlying structure and function of nationalism as a form of representation masked by nationalist ideologies. To investigate the reorientation of Arabs and Muslims from Ummah to adopting nation-state, I utilize Spivak's criticism of the system of representation along with Foucault's theorization of discourse. I argued along Edward Said that although the Western national discourse might have influenced the Arab nationalists, I do not believe they prevented them from consciously appropriating nationalism in a free creative way. I also explained that the Arab adoption of a secularist separatist nationalism was more an outcome than an effect in the dissolution of the supranational Ummah, since according to Hourani that "explicit Arab nationalism" did not emerge until the end of the nineteenth century. I wrote this dissertation with the hope that I could, to use Masood Raja's literary concepts, inundate the modern Arabic novel with "silenced knowledge" to not only prevent the untrained Western readers from reducing these works to a set of assumptions, prejudices, or preferences but also to shift the texts from being a point of arrival to a being a point departure.
An Empirical Investigation of the Medical Supply Chain and Its Impact on Human Solid Organ Transplantation
The objective of this dissertation is to first identify if there are any academic research gaps in our understanding of the medical supply chain and secondly to understand the role and impact of logistics on the human organ transplant process. The first essay identifies the current status of medical supply chain literature and provides future direction for improving the medical supply chain. This was accomplished by preforming a systematic literature review and a bibliometric analysis from 2,160 publications was conducted. The second essay explores how logistical aspects impact transplant logistics performance and the quality of life for the transplant recipient. Survey data was collected from medical professionals and analyzed using structural equation modeling. The third essay identifies the factors are influencing the number of donor kidneys discarded each year. A retrospective analysis of all deceased donor kidneys procured in hospitals in UNOS region 4 (Texas and Oklahoma) from January 1, 2001, to June 28, 2021, was conducted. Data was analyzed using multinomial logit regression and panel data analysis. As a result, we identified several medical and logistics factors that have influenced the number of donor kidneys discarded in the United States.
Engaging with the IR Remotely
Book chapter exploring approaches and methods of engaging with an institutional repository (IR) remotely.
Environmental Control of Pacing in Cougars
Pacing, a common form of stereotypy in captive animals, poses challenges for animal welfare and conservation initiatives. The current study used a comprehensive measurement system to investigate the impact of introducing a food-related activity on the daily patterns of multiple behaviors, including stereotypic pacing, in two zoo-housed cougars. The results showed that, while the intervention did not mitigate pacing overall, it did cause a shift in the cougars' routines. This demonstrated the significant influence of keeper behavior on the animals. Furthermore, the differing effects on each cougar's behaviors underscored the necessity for individualized interventions tailored to the specific needs of animals.
An Evaluation of Cross-Function Stimuli in the Treatment of Automatically Maintained Problem Behavior
Noncontingent reinforcement (NCR) is a possible alternative to differential reinforcement of other behaviors (DRO) that may operate through a similar mechanism. In the research, the participant's problem behaviors were maintained by automatic reinforcement or even multiply maintained. NCR is the method to intervene with the participant who had no clinical effect on using sensory integration therapy (SIT) to reduce problem behaviors in the previous study. The results showed that NCR is an effective way to decrease the problem behaviors without extinction burst.
An Evaluation of the Utility of Fixed Ratio 1 Schedule Contingent Reinforcement on Variability to Increase the Diversity of Activity Selections and the Treatment of Problem Behavior Occasioned by Interruption Routines
Adults with autism spectrum disorder (ASD) and intellectual disability (ID) are the majority of population in residential settings. Many clients in residential settings engage in problem behavior that interferes with their daily routine and work requirements. Restricted and repetitive behavior are one of the features of ASD diagnosis, typically in the form of invariable responding and predictable responses. Differential reinforcement has been used to produce and maintain response variability. I evaluated the utility of a fixed ratio 1 (FR1) schedule on variability to increase the diversity of activity selections in the treatment of problem behavior occasioned by the interruption of routines. Chase engaged in problem behaviors in his bathroom routine, no matter by himself or with his housemate. Results demonstrated a reinforcement-based treatment increased both variable and novel selections while decreasing the rate of self injurious behavior.
Examination of Potentially Morally Injurious Events and Moral Injury in Medical Professionals
The current study examined the nature and extent of endorsement of PMIEs, the nature and severity of MI symptoms related to endorsement of a PMIE, and the relations between extent of endorsement of PMIEs and MI symptoms. We hypothesized that (1) PMIEs perpetrated by others would be endorsed to a greater extent than PMIEs perpetrated by oneself; (2) medical professionals who endorsed a PMIE would report significantly greater severity on all MI symptoms compared to medical professionals who did not endorse a PMIE; (3) experiencing PMIEs (perpetrated by oneself and/or others) to a greater extent would predict higher levels of MI symptom severity, and MI symptom severity would specifically be most strongly predicted by PMIEs perpetrated by oneself. Hypotheses were examined using t-tests, Pearson's r correlations, and multiple multivariate regression analyses. First, the current study found that PMIEs perpetrated by others were endorsed to a greater extent than those perpetrated by themselves; second, greater exposure to PMIEs was associated with significantly greater severity of 10 of the 14 outcomes. Third, PMIEs perpetrated by oneself predicted more MI symptomatology than PMIEs perpetrated by others, indicating that while PMIEs perpetrated by others are more common, PMIEs perpetrated by oneself are more strongly associated with MI outcomes. This study highlights the widespread and harmful impact of PMIEs among medical professionals.
Examining the Educational Depth of Medical Case Reports and Radiology with Text Mining
The purpose of this dissertation was to use the technology of text mining and topic modeling to explore unobserved themes of medical case reports that involve medical imaging. Case reports have a valuable place in medical research because they provide educational benefits, offer evidence, and encourage discussions. Their form has evolved throughout the years, but they have remained a key staple in providing important information to the medical communities around the world with educational context and illuminating visuals. Examining medical case reports that have been published throughout the years on multiple medical subjects can be challenging, therefore text mining and topic modeling methods were used to analyze a large set of abstracts from medical case reports involving radiology. The total number of abstracts used for the data analysis was 68,845 that were published between the years 1975 to 2022. The findings indicate that text mining and topic modeling can offer a unique and reproducible approach to examine a large quantity of abstracts for theme analysis.
Experimental and Numerical Investigation of a Novel Cold-Formed Steel Long Span Truss
This thesis describes the experimental and numerical investigation of a novel cold-formed steel 48ft and 54ft long span truss. The truss we designed was to be used as the roofs of large buildings, such as warehouses, hangars, sports arenas. The investigation includes both experimental and numerical testing, the experimental testing of the truss under uniform loads (increasing loads) to determine its deflection and load carrying capacity. The numerical test included developing a finite element model of the truss in SolidWorks and using a finite element model of the truss in ABAQUS to simulate the experimental tests. The findings of this study can be used to improve the design of cold-formed steel long span trusses. The study also provides valuable information for future studies on the modeling of trusses with different cold-formed steel members and the behavior of trusses under load.
Exploring Psychological Intimate Partner Violence Using Brief Expressive Writing Essays
Non-physical intimate partner violence (NPIPV) is the most pervasive type of abuse, yet literature has predominantly focused on physical IPV victimization. This study employed a mixed-methods design utilizing archival expressive writing data previously collected to identify the presence of NPIPV victimization. Participants wrote about their experience after a relationship dissolution using the expressive writing paradigm. They were asked to share their deepest thoughts and feelings across two sessions. A constructivist grounded theory approach established the theoretical framework for coding the presence of NPIPV acts between romantic partners. Four themes of NPIPV were established (degradation, isolation, control, and jealousy). Disclosure of NPIPV and other themes were also evident in these data. Quantitative analyses assessed changes in participants' psychological distress after completing a brief writing intervention. The intervention increased the likelihood of NPIPV victimization being mentioned from Time 1 to Time 2 writing sessions. This study increases clinical awareness regarding NPIPV by providing insights into this longest-sustained IPV subtype. All participants reported a reduction in avoidance symptoms after completing the writing intervention. Finally, gender continues to complicate this field as researchers must acknowledge both the existence of men's victimization experiences and the greater severity of women's victimization. Clinical implications demonstrate a strength in narrative therapy when processing relationship dissolution particularly when NPIPV victimization is present.
Exploring the Association of Language Brokering and Parent-Child Relationship in Korean Immigrant Families
This study focuses on investigating the dynamics of language brokering as Korean immigrant families experience environmental challenges associated with immigration. This study was conducted with qualitative research design with purposive sampling of Korean immigrant families. Six parent-child dyads were recruited and participating children were between 12 to 16 years old. Semi-structured interviews were conducted separately with parents and children in either English or Korean. Thematic analysis was employed for analyzing the transcribed interviews. The Dedoose software program was applied to assist the coding process. 12 subthemes were revealed under four main themes, which were aligned to the study's research questions. The twelve subthemes included parents' dependence on children, vulnerability and resilience of Korean immigrant families, children's socioemotional development through language brokering, and the role of first-born daughter in the family. Parent and child responses indicated how language brokering affects can be a risk in relation to children's development (i.e., with responsibility of language brokering leading the child to experience stress or experience the responsibility of translation as a burden. Positively, respondents indicated that the parent and child experienced a greater sense of empathy for each other's roles. The results derived from this study were aligned with the results of previous research conducted in the field in that language brokering affects parent-child relationship and the socioemotional development of children. The study adds to the literature with the interviewing both parents and children, thereby hearing both perspectives and experiences of parents and children on language brokering and parent-child relationships could be obtained. This study targeted Korean immigrant families since there is a lack in literature that have studied this population in relation to language brokering.
Exploring the Relationship between Mental Health and Substance Use, Stable Housing, and Completion of the RISE Court Program
This thesis analyzes participants of the RISE Court program, a specialized court in Tarrant County, Texas, focusing on women involved in prostitution. The study investigates the intricate relationship between mental health, stable housing, substance abuse, and successful completion of the court program. Through a comprehensive analysis of participant data, the findings reveal insights into the intersection of mental health and the outcomes of participants in the RISE Court program. Contrary to the initial hypotheses, this study presents compelling evidence that mental health issues do not significantly hinder participants from completing the court program nor acquiring stable housing during their participation. However, the data strongly supports the hypothesis that participants with mental health problems are more likely to engage in substance use during the program. Notably, the study found that a substantial portion (71%) of the sample had documented mental health diagnoses, highlighting the pervasive nature of mental health challenges within this demographic. This research represents a considerable stride towards comprehending the complexities surrounding the criminal justice system's interventions for individuals engaged in prostitution, shedding light on the role of mental health in shaping their experiences within the RISE Court program. The findings have implications for the development of more effective, holistic strategies for rehabilitation and reintegration within specialized courts targeting this vulnerable population.
Exploring the ROI of 1:1 Computing Programs at the High School Level
This dissertation explored the cost and value of 1:1 computing programs in high schools in Texas. The study examines whether the total cost of ownership of these programs can be justified by the student testing gains and graduation rates. It investigates whether student learning outcomes show a definable correlation between positive gains and the implementation of 1:1 computing programs. The study also explores whether there is a measurable return on investment of 1:1 programs based on testing gains and graduation rates. The research used the State of Texas Assessment of Academic Readiness exam scores to validate assumptions and test the hypothesis. The study found no clear link between the addition of 1:1 computing programs and the realms of student success. While there is marginal improvement in student outcomes, there is only circumstantial evidence that laptops and devices are the catalysts for the change. The dissertation also found that the total cost of ownership (TCO) is a significant portion of the district's spending, costing millions of dollars, and that the financial disclosure and budget information data was either missing, incomplete, or over-generalized, causing an issue for assessing program effectiveness or ROI. Despite this lack of transparency, there is a slight positive ROI trend based on the data reviewed during the observation period.
Factors Affecting MeHg Contamination of Spiders and Insect-Mediated MeHg Flux from Human-Made Ponds
The present study focused on methylmercury (MeHg) in emergent aquatic insects and spiders from human-made ponds. This dissertation addresses two main topics: (1) factors affecting variation in spider MeHg concentrations around human-made ponds and (2) the magnitude of MeHg transported out of human-made ponds by emergent aquatic insects (insect-mediated MeHg flux). Spiders were specifically targeted in this study because they have been proposed as sentinels of MeHg contamination (organism whose tissue concentrations reflect the level of MeHg in the environment). Spider MeHg concentrations were related to spider diet, size, and proximity to waterbody, but affected individual spider taxa differently. In a second study, I found that only "large" spiders within a taxa had tissue concentrations positively related to prey MeHg concentrations. These results indicate that the relationship between spider and prey MeHg could be size-dependent and that "large" spiders within a taxa may better reflect ambient MeHg contamination. Finally, I tested a conceptual model hypothesizing insect-mediated MeHg flux from human-made ponds is controlled by pond permanence and fish presence. In agreement with the conceptual model, insect-mediated MeHg flux from ponds was suppressed by the presence of fish, likely due to fish predation on emergent insect larvae. I found the mean aggregate MeHg flux was approximately 6 times higher from ponds without fish than from ponds with fish. The suppression of insect flux by fish was stronger for large insect taxa than small insect taxa. Results of this study indicate that community structure can influence the cross-system transport of contaminants, like MeHg, from ponds to terrestrial food webs.
Fatty Acid Amide Hydrolases in Upland Cotton (Gossypium hirsutum L.) and the Legume Model Medicago truncatula
Fatty acid amide hydrolase (FAAH) is a widely conserved amidase in eukaryotes, best known for inactivating the signal of N-acylethanolamine (NAE) lipid mediators. In the plant Arabidopsis thaliana, FAAH-mediated hydrolysis of NAEs has been associated with numerous biological processes. Recently, the phylogenetic distribution of FAAH into two major branches (group I and II FAAHs) across angiosperms outside of Arabidopsis (and in other Brassicaceae), suggests a previously unrecognized complexity of this enzyme. Although A. thaliana has long been used to assess biological questions for plants, in this case it will fall short in understanding the significance of multiple FAAHs in other plant systems. Thus, in this study, I examined the role (s) of six FAAH isoforms in upland cotton (Gossypium hirsutum L.) and two FAAHs in the legume Medicago truncatula.
FruitPAL: An IoT-Enabled Framework for Automatic Monitoring of Fruit Consumption in Smart Healthcare
This research proposes FruitPAL and FruitPAL 2.0. They are full automatic devices that can detect fruit consumption to reduce the risk of disease. Allergies to fruits can seriously impair the immune system. A novel device (FruitPAL) detecting fruit that can cause allergies is proposed in this thesis. The device can detect fifteen types of fruit and alert the caregiver when an allergic reaction may have happened. The YOLOv8 model is employed to enhance accuracy and response time in detecting dangers. The notification will be transmitted to the mobile device through the cloud, as it is a commonly utilized medium. The proposed device can detect the fruit with an overall precision of 86%. FruitPAL 2.0 is envisioned as a device that encourages people to consume fruit. Fruits contain a variety of essential nutrients that contribute to the general health of the human body. FruitPAL 2.0 is capable of analyzing the consumed fruit and then determining its nutritional value. FruitPAL 2.0 has been trained on YOLOv5 V6.0. FruitPAL 2.0 has an overall precision of 90% in detecting the fruit. The purpose of this study is to encourage fruit consumption unless it causes illness. Even though fruit plays an important role in people's health, it might cause dangers. The proposed work can not only alert people to fruit that can cause allergies, but also it encourages people to consume fruit that is beneficial for their health.
Glucose-Induced Developmental Delay is Modulated by Insulin Signaling and Exacerbated in Subsequent Glucose-Fed Generations in Caenorhabditis elegans
In this study, we have used genetic, cell biological and transcriptomic methods in the nematode C. elegans as a model to examine the impact of glucose supplementation during development. We show that a glucose-supplemented diet slows the rate of developmental progression (termed "glucose-induced developmental delay" or GIDD) and induces the mitochondrial unfolded protein response (UPRmt) in wild-type animals. Mutation in the insulin receptor daf-2 confers resistance to GIDD and UPRmt in a daf-16-dependent manner. We hypothesized that daf-2(e1370) animals alter their metabolism to manage excess glucose. To test this, we used RNA-sequencing which revealed that the transcriptomic profiles of glucose-supplemented wildtype and daf-2(e1370) animals are distinct. From this, we identified a set of 27 genes which are both exclusively upregulated in daf-2(e1370) animals fed a glucose-supplemented diet and regulated by daf-16, including a fatty acid desaturase (fat-5), and two insulin-like peptides (ins-16 and ins-35). Mutation of any of these genes suppresses the resistance of daf-2(e1370) to GIDD. Additionally, double mutation of ins-16 and ins-35 in a daf-2(e1370) background results in an increase in constitutive dauer formation which is suppressed by glucose supplementation. Further investigation of the insulin-like peptides revealed that ins-16 mutation in a wild-type background results in upregulation of ins-35 and DAF-16 nuclear translocation regardless of diet; however, unlike daf-2(e1370), this translocation is not associated with resistance to GIDD. Taken together, these data suggest that glucose-supplemented daf-2(e1370) animals maintain developmental trajectory in part through upregulation of specific insulin-like peptide genes and fatty acid desaturation and contribute to a deeper understanding of the mechanisms underlying the resistance of daf-2(e1370) animals to GIDD. We also showed another fascinating aspect of GIDD: it becomes more pronounced in subsequent generations exposed to a glucose-supplemented diet, suggesting that the parental glucose diet has an impact on the developmental progression of their offspring.
"Google is my friend": An Exploration of Older Adult Media Literacy
The advancement and incorporation of media in daily life continue to grow exponentially as the median age of humanity continues to rise. While there are media literacy education programs targeted toward children and adolescents, older adults are often left out of these initiatives. Based on ethnographic research conducted at two senior centers in Denton, TX, this thesis explores the way older adults analyze and interact with media. Data collection methods include participant observation and semi-structured interviews with senior center members over the age of 65. The research findings highlight how older adults navigate an expanding information society and how they lean on their community for support. These findings laid the foundation for the creation of a media literacy educational seminar given at both senior centers.
"The Gordita's Guide to Body Positivity"
"The Gordita's Guide to Body Positivity" is an autobiographical documentary reflecting on society's expectations of the female body image and how it affects Latinx women. Through personal recollections, media content, and archival material, the film explores beauty expectations, body discrimination, and body positivity. The document analyzes the documentary styles such as autoethnography and narration incorporated into the film and provides historical and theoretical context to body image in the Latinx culture and how the media has affected body image, beauty ideals, and eating disorders. In addition, the pre-production, production, and post-production process is detailed.
Green Manufacturing of Lignocellulosic Fiber through Bacterial Degradation Process
Lignocellulose is the most abundant biopolymer on earth and offers excellent potential for sustainable manufacturing. Because lignocellulose is structurally complex and resistant to decomposition, innovative degradation strategies are necessary to unlock its value. In this dissertation, a green manufacturing process through enzyme-triggered self-cultured bacteria retting for lignocellulosic fiber was developed and investigated. The mechanism of the lignocellulosic fiber retting at a controlled degradation strategy was studied. This enzymatic degradation strategy utilizes a small amount of enzyme to trigger a large aggregation of specific bacteria to obtain clean fibers. Industrial hemp (Cannabis sativa L.) fiber was successfully retted with this strategy. The degradation of pectin was proved through an environmental scanning electron microscope and reducing sugar analysis. The bacterial successions were identified by 16S rRNA gene metagenomic sequencing. The results showed that Bacillaceae dominated the hemp retting conditions containing 1% pectinase, suggesting that pectinase can manipulate bacterial community succession by changing the nutrients available to bacteria through the degradation of pectin. This degradation strategy has 20-25% less environmental impact than the thermochemical degradation strategy, resulting in better fiber consistency and much shorter processing time (3-5 days) than the traditional water degradation strategy. The study on the degradation of lignin-rich lignocellulose also contributes to the understanding of the natural formaldehyde release mechanisms from wood.
Harmonic Function in Rock: A Melodic Approach
This dissertation explores the influence of melody on harmonic function in pop and rock songs from around 1950 to the present. While authors define the term "function" in several ways, none consider melody in their explanations, and I contend that any discussion of harmonic function in rock must include melody. I offer a novel perspective on function by defining it through what I call tension-as-anticipation, and I define a "melodic function" that accounts for the sense of tension and relaxation a melody creates within a particular moment in a track. My dissertation defines two types of melodic function—dominant and tonic—based on the melody's goal-directed scale-degree content, position within a phrase, and relation with the harmony. Dominant-melodic function results in two musical phenomena that I call the "imposed dominant" and the "dominant remainder." An imposed dominant occurs when a dominant-melodic function is initially dissonant with the harmony and resolves over a tonic. A dominant remainder occurs when a dominant-melodic function occurs over a harmonic resolution to the tonic, creating a slower dissipation of tension. Tonic-melodic function produces a phenomenon I call the "tonic anticipation," where a melody outlines a tonic mode over a pretonic harmony, creating a maximum sense of tension-as-anticipation. By including melody in considering harmonic function, we can more adequately describe the cycles of tension and resolution found in pop styles.
"Have You Ever Had a Broken Heart?"
Have You Ever Had Broken Heart? is a collection of essays that interrogate memory, loss, and grief through the intersection of personal narrative, films, the actress Frances Farmer, and woman saints and mystics from the twelfth through seventeenth centuries who were punished for daring to speak to G-d. The essays engage with autotheory and include a myriad of forms, such as segmented, one sentence, and hybrid works. The films discussed range from the philosophical, such as Ingmar Bergman's Winter Light (1963), to Graeme Clifford's biopic, Frances (1982), to catechize the grief of the persona losing her mother and sister to a hit and run car wreck in June 2022. The persona traverses the realm of the mystics and saints, including Marguerite Porete, Sor Juana Inez De La Cruz, and Joan of Arc, examining their respective quests to experience the unseen and often silent divine, while questioning her longing for G-d, and simultaneously believing G-d cannot exist. Yet, within this confusion, she finds herself immersed in memories which carry the presence of her mother's love.
Homoleptic and Heteroleptic Platinum(II) Complexes for Organic Light Emitting Diodes and Humidity Sensors: Synthesis, Characterization, and Applications
This dissertation focuses on the design, synthesis, characterization of platinum (II) pyridylazolate complexes and develop high performance organic light emitting diodes (OLEDs) and design and execute high-sensitivity humidity sensors based on the luminescent metal-organic complexes of platinum. A majority of existing platinum compounds do not dissolve in organic solvents, making it difficult to analyze the photophysical characteristics of complexes in solution, a key part of understanding chemical photophysical properties. Furthermore, due to the poor quantum yield, it is inefficient for use in devices such as OLEDs. Chapter 2 reports the synthesis and characterization of a novel heteroleptic platinum(II) pyridylazolate complex with high solubility and quantum yield. The photochemistry of the complex is studied, including efficiency, emission profiles, and lifetimes at different temperatures. Chapter 3 reports the power efficiency (lm/W), current efficiency (cd/A), external quantum efficiency (EQE), luminance and operating voltage (V) of OLED devices made with the heteroleptic platinum(II) pyridylazolate complex. The relation between thickness of hole transport layer and electron transport layer on performance of devices has been studied through building a variety of devices. Chapter 4 includes application of a homoleptic platinum(II) pyridylazolate complex in humidity sensor. In many environments, the relationship between moisture content and emissive wavelength has been investigated. This research reveals that regardless of the humidity level, there is a link between increasing the temperature and decreasing the moisture absorption capacity of the complex.
Horses Against Tanks: Historical Memory and the German Invasion of Poland
The entrance of the German Invasion of Poland and depiction thereof into modern historiographical conversations offers historians superior articulation of the creation of historical memory, mythos, and identity ‒ especially in wider terms of European Imperialism. By utilizing the current trends in gendering of empire, the use of auto-biography and life writing to understand felt realities and obfuscated truths, and the attempts by empire to queer and utilize labeled deviations to control and gain power over their colonized subjects, one is presented a better understanding of how the German Invasion of Poland fits into the story of empire and indigeneity. That story continues past the Third Reich however, as German propaganda in its various forms was accepted as truth after the Second World War, providing justification for and rationalizing post war political power structures of Western nations. As the threat of a cold war with the USSR loomed, many in the American military felt it necessary to accept and support German myths about their military prowess (and non-culpability for the Holocaust) and the inferiority of Slavic military forces. By analyzing not the myths themselves, but how they were created and propagated, historians can add to this historical conversation a case study of just how two seemingly opposed power structures can mobilize similar myths as justification for their own desires and decisions, and in doing so, mythologize the identity and memory of the earnest beginning of the Holocaust.
The Idiomatic Techniques and Procedures of Composer Kevin Walczyk (b. 1964) that Define a Unique Musical Language
Award winning composer Kevin Walczyk's describes himself as a "musical storyteller," using all musical elements of structure, melody, harmony, and counterpoint to convey programmatic content. A variety of subjects are conveyed that include historical events, people, physical objects or locations, and literary texts. Deeper matters, such as spiritual themes, are also often incorporated in his music that enhance the musical program. The technical procedures employed—pertaining particularly to the expression of programmatic content—has produced a unique musical language that stands out in the modern compositional landscape. What are these inherent idiomatic features, and how are they exhibited? The purpose of this dissertation is to provide a detailed examination of Walczyk's distinct musical language. A critical analysis of the technical procedures used to convey his programmatic content, as well as insights into his influences and writing process, illuminate the attributes of this a posteriori musical language. The two works selected for this study to demonstrate this are Symphony No. 2: Epitaphs Unwritten and Talking Winds, both written for wind band.
The Impact of Kindergarten Classroom Assignment on Classroom Teachers and Student Achievement
To determine the impact of an administrator's decision on student placement in kindergarten classrooms, teachers were asked to share their perceptions on how that decision impacted their ability to deliver instruction and follow the district scope and sequence, as well as how that decision impacts student academic achievement and social and emotional development. This qualitative study was designed to gather data from kindergarten teachers using focus group interviews and individual interviews of campus principals from two campuses within the same district. The following two ways in which kindergarten classrooms were created were explored: (a) by random assignment or (b) knowledge of students' academic and behavioral performance based on information relevant to their Pre-K experience. Campus principal participants reported that they each chose their method to provide equity in the classrooms and fairness amongst their teachers. Teacher participants reported that overall, they preferred to have as much information about incoming students as possible and to be a part of the process of placing students into classrooms for the following year. By examining these teachers' perspectives, the findings from this study may positively influence policy and practice for campus administrators as they decide how they will place students in kindergarten classrooms. Continued qualitative examination of student achievement could help determine if one method of placement positively impacts student achievement. Data collected from a larger sample within the district or expanded to compare between districts could help campus administrators make positive classroom placements for kindergarten students. Also, a quantitative study using a survey might provide a more expansive view of the impact of administrators' process of assigning kindergarten students to classrooms.
The Impact of Leadership on School Culture and Teacher Retention
To determine the impact that school leaders have on school culture and teacher retention, a sequential explanatory mixed methods approach was used to study schools in a district feeder pattern in in a large, suburban district in Texas with a student population of approximately 25,000. In Phase 1, teachers at one elementary, one middle, and one high school were asked to complete a 26-question Likert scale survey about school culture. The last statement in the survey asked participants if they were willing to participate in a focus group about school culture and teacher retention. In Phase 2, focus group interviews were conducted with volunteer participants who took the survey and stated they would be interested in participating in a focus group. Three focus groups were held to divide the participants by grade level grouping taught: elementary, middle, and high school. Focus group participants stated that they believe school leaders play a vital role in creating the culture of the school and in teachers' desire to remain not only teaching at their school, but also remaining in the field of education. The survey data supported these findings. By examining teachers' perspectives, the findings of the study may positively inform and influence district hiring practices, develop leadership profiles and behaviors, and provide school leaders with ways to recruit and retain teachers. Further research could include a case study at one specific school or expanding the sample size and including more schools or studying a variety of districts to find additional ways to build school culture and retain teachers.
The Impact of Socioeconomic Status on Attachment Security and Psychological Well-Being
Socioeconomic status (SES) has been shown to reliably predict parenting practices, family well-being, and psychological outcomes throughout the lifespan. The current study employed a cross-sectional, quantitative design in which adult participants (N = 336) completed an online survey measuring demographic variables, financial stress, attachment security, and psychological well-being. The study results suggest that (a) both current and family history of financial stress negatively predicted attachment security, (b) SES positively predicted general psychological well-being, although individual SES factors (e.g., income, subjective SES, financial stress) demonstrated nuanced relationships with well-being, life satisfaction, and resilience, (c) family history of financial stress and attachment security mediated the relationship between calculated social status and psychological well-being, and (d) the mediated relationship between calculated social status and psychological well-being via the pathway of attachment security was significant for racial/ethnic minorities, but not for White participants. The present findings contribute to the current literature by (1) including multidimensional measurements of SES, (2) addressing nuances in the relationship between SES and attachment, (3) emphasizing the role of financial stress on attachment security, and (4) providing initial cross-cultural considerations in the relationships among SES, attachment, and psychological well-being. Future researchers are encouraged to conduct longitudinal analyses, amplify sample recruitment efforts, and expand SES, attachment, and racial/ethnic identity measurement. Lastly, the current study has significant clinical implications regarding multiculturalism and social justice, relational schemas developed in context of financial stress, and cognitive appraisal regarding subjective SES.
The Impact of Team Size on Principal Self-Efficacy in Their Role as Instructional Leaders
The ever-changing role of public-school principals is complex and overwhelming. Because instructional leadership impacts teaching practices and student achievement, this important principal role should be cultivated with principals having sufficient time to engage as instructional leaders. A generic qualitative inquiry methodology was used to explore how the size of an administrative team impacts principals' instructional leadership self-efficacy. Exploration was achieved through 10 one-on-one, semi-structured interviews and one focus group interview. The data suggest that team size does impact an administrator's ability to serve as an instructional leader. Participants reported that larger teams provided more time for working with individual teachers and collaborative teams. Although interviewed administrators did not always abandon instructional leadership when there was insufficient time, they did often sacrifice personal time to fit it in. Administrators did not believe that they had enough time to be instructional leaders, regardless of the team size, but they shared that there was more time to develop their instructional leadership principal self-efficacy when working on larger teams. Larger teams also provided administrators with greater diversity of perspectives and experiences, which they said cultivated their self-efficacy. Consequently, an opportunity exists for district administrators to consider the specific needs of each campus, the exhaustive list of duties given to campus administrators, and the importance of instructional leadership when making staffing decisions about the number of administrators allotted to each campus.
Increasing Caregiver Reliability on Anecdotal Assessments
Functional analyses are the gold standard of confirming maintaining variables of problem behavior. Despite widespread support, many clinical settings instead use anecdotal assessments. These have been shown to have poor reliability when used by non-experts but can be useful for confirming maintaining variables of problem behavior when agreement has reached a certain level. We used behavior skills training to teach new staff member pairs behavior function to increase their reliability on these assessments. We found that although agreement increased slightly, this was not clinically significant. Out of the two pairs of participants one pair of participants was able to identify their client's maintaining variable of problem behavior. Future research should investigate the type of training used for non-experts for example training non-experts to state problem behavior in objective operational terms.
Instructors and Underrepresented Students in Microbiology: Educational Digital Tool Use, Trends, Perceptions, and Success
The purpose of this three-article dissertation was to expand knowledge and theory regarding digital tool use in biology laboratory courses, such as microbiology, which requires specific laboratory skill development through the perception of instructors and students. Article 1 establishes the broad digital literacy and fluency problem in education by providing definitions and the context behind digital literacy fluency and its impact on acquisition of knowledge in digital learning environments. The study provided a picture of the lack of knowledge about the use of digital tools in education and practical problems around appropriate implementation, infrastructure, and preparedness. Article 2 presents results of a literature research study about the foundational, pandemic-induced, and current digital tool use in biology and microbiology lab courses. Recommendations for improvement in digital tool implementation, pedagogical approach, and appropriate selection to meet learning outcomes were provided. Article 3 describes a 3-layered study to build a new instrument to understand minority-student perceptions of identity and digital literacy and technology barriers on student success in STEM courses. The study identified challenges and benefits of digital tool use in virtual microbiology lab courses, unique challenges of underrepresented populations, and the need to develop an instrument to capture the context of this unique population.
Investigating Novel Streptomyces Bacteriophage Endolysins as Potential Antimicrobial Agents
As antibiotic resistance has become a major global threat, the World Health Organization has urgently called scientists for alternative strategies for control of bacterial infections. Endolysin, a protein encoded by a phage gene, can degrade bacterial peptidoglycan (PG). Currently, there are three endolysin products in the clinical phase. We, thus, are interested in exploring novel endolysins from Streptomyces phages as only a few of them have been experimentally characterized. Using bioinformatics tools, we identified nine functional domain groups from 250 Streptomyces phages putative endolysins. NootNoot gp34 (transglycosylase; Nt34lys), Nabi gp26 (amidase; Nb26lys), Tribute gp42 (PGRP; Tb42lys), and LazerLemon gp35 (CHAP; LL35lys) were selected for experimental studies. We hypothesized that (1) the proteins of interest will have the ability to degrade PG, and (2) the proteins will be potential antimicrobial agents against ESKAPE safe relatives. The results showed that LL35lys, Nb26lys and Tb42lys exhibit PG-degrading activity on zymography and hydrolysis assay. The enzymes (400 µg/mL) can reduce PG turbidity to 32-40%. The killing assay suggested that Tb42lys possess a boarder range (Escherichia coli, Pseudomonas putida, Acinetobacter baylyi and Klebsiella aerogenes). While Nb26lys can attack Gram-negative bacteria, LL35lys can only reduce the growth of the Gram-positive strains with an MIC90 of 2 µg/mL. A higher concentration (≥300 µg/mL) of Nb26lys is needed to treat P. putida and K. aerogenes. Therefore, endolysins from Streptomyces phage have potential as possible antimicrobial agents against ESKAPE bacteria.
Investigating the Molecular Framesworks of Phloem-Cap Fiber Development in Cotton (Gossypium hirsutum)
The current study focuses on the vascular cambium and the reiterative formation of phloem fiber bundles in cotton stems. The role of the TDIF-PXY-WOX pathway was examined in regulating cambial activity and the differentiation of phloem fibers. A study was conducted to identify and characterize the cotton WOX family genes, focusing on WOX4 and WOX14, aiming to identify and analyze their phylogenetic relationships, tissue-specific expression profiles, functional roles, and metabolic consequences. Through a sequence analysis of the Gossypium hirsutum genome, 42 cotton loci were identified as WOX family members. GhWOX4 exhibited a close homology to 7 loci, while GhWOX14 displayed homology with 8 loci. Tissue-specific expression analysis revealed prominent expression patterns of GhWOX4 and GhWOX14 in cotton internodes and roots, suggesting their involvement in vascular tissue development. Functional studies utilizing VIGS (virus-induced gene silencing) demonstrated that the knockdown of GhWOX4 and GhWOX14 resulted in a significant reduction in stem diameter and bast fiber production. This result suggests that secondary phloem fiber development is regulated by GhWOX4 and GhWOX14 genes in cotton. Additionally, the metabolic profiling of VIGS plants revealed significant alterations in amino acids, organic acids, and sugars, with implications for primary metabolic pathways. These findings suggest that GhWOX4 and GhWOX14 play pivotal roles in cotton plant development, including vascular tissue growth and phloem fiber production, and metabolic regulation.
"The Just For Fun Talent Show"
Three individuals prepare themselves to perform unique talents on a live stage, proving to themselves and others that they are far more capable than they imagined.
Kinetics and Atmospheric Chemistry Studies of Halogenated Species
Quantitative information about halogenated hydrocarbons is important for understanding their impact on atmospheric ozone chemistry and climate change, their regulation, and the devising of improved substitutes. The Montreal Protocol aimed to regulate the utilization and manufacturing of hydrochlorofluorocarbon compounds (HCFCs), contributing to ozone layer depletion. The 2016 Kigali Amendment to the Montreal Protocol agreement, Annex C listed 274 HCFCs. Only 16 of them have been measured experimentally. The rest were set to zero by default. These reported global warming potentials (GWPs) play a crucial role in formulating policies for gradually reducing the usage and production of HCFCs to prevent atmospheric impact. Here we are studying 1-chloro-1-fluoro-ethane (CH3CHFCl) as a test of past theory. There are no prior experimental measurements of the reactivity of CH3CHFCl with hydroxyl (OH) radicals, which primarily determines its atmospheric lifetime, nor of its infrared (IR) spectrum. Saturated hydrofluorocarbons (HFCs) are non-ozone depleting substitutes for chlorofluorocarbons deprecated under the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, but they exhibit high global warming potentials (GWPs) and the Kigali Amendment adopted in 2016 outlines their phase down. Unsaturated HFCs offer more reactive alternatives, whose likely short atmospheric lifetimes would imply small GWPs. Because their GWPs are smaller than those for saturated HFCs by several orders of magnitude, and especially for fully fluorinated examples, several halogenated olefins are under consideration for practical application. We studied HCF2CF2CF=CF2, cis-HCF=HCF, trans HCF=HCF, CF2=CH2 unsaturated HFCs.
Kinetics and Thermochemistry of Halogen and Nitrogen Compounds
Halogen and nitrogen containing compounds play a key role in the atmospheric chemistry of the Earth. Through a mixed computational and experimental approach, the kinetics of these compounds with radicals common to the atmosphere have been explored. Using fundamental measurements such as the IR absorption cross-section, the rate constants of atmospheric reactions and the properties of product molecules have been derived. These results have been further extended to environmental applications such as the Global Warming Potential for a species. The present results can be used as a calibration for further experiments and as checks on computational predictions of environmental properties. Such modeling can aid in the development of future industrial reagents that are less hazardous to the atmosphere.
Leadership Practices and Processes that Close Opportunity Gaps for Socioeconomically Disadvantaged and Minoritized Students: A Case Study of a High-Needs Title 1 Elementary School
The purpose of this qualitative, single case study was to identify leadership practices and processes that contributed to the success of a single High Needs, Title 1 elementary school that has experienced acknowledged superior academic success, particularly for its minoritized and low socioeconomically disadvantaged students, as indicated by the school's success on the State of Texas Assessment of Academic Readiness (STAAR) tests. The study sought to explore the principal's and teachers' conception of leadership for success and to examine what effective practices and processes were employed at a high-needs, high-performing campus that accounted for its success. The study applied the culturally responsive school leadership (CRSL) framework to analyze the practices employed at the school. Results of the study, from interviews with the principal and a focus group of three teachers, indicated that not only did they apply the principles of the CRSL framework, which employed the critical self awareness, culturally responsive curricula and teacher preparation in a culturally responsive and inclusive school environment which engaged parents and students in community contexts, but they also enhanced their effectiveness through the provision of additional resources for teachers and students, with a heavy reliance on data to guide academic decisions.
The Local Organization of Refugee Service Provision: A Qualitative Comparison of Two Resettlement Cities in Texas
This comparative case study examines the organizational variations in refugee services in Dallas and Amarillo, Texas. Engaging sociological theories of organizations, migration, and the state, this study conceptualizes immigrant-serving organizations as brokers that operate within fields of similar entities that channel resources and services to refugees. Drawing on 60 in-depth interviews and over two hundred hours of participant observation, this study finds two distinct models of resource brokerage. In Dallas, immigrant-serving organizations operated as networked resource brokers, characterized by high levels of collaboration, robust local political support, and community engagement through consistent volunteer labor. These characteristics facilitated the sharing of resources and knowledge, resulting in the establishment of more professionalized services for immigrants and refugees. In contrast, immigrant-serving organizations in Amarillo operated as atomized resource brokers, characterized by fragmented collaborations, inter-organizational competition, limited volunteer labor, and varying levels of political support from local representatives. This atomized brokerage model hindered the efficient allocation of resources and support, leading to fragmented and less comprehensive services for refugees. In conclusion, this study provides valuable insights into the variations within the organizational fields of ISOs in Texas. The comparative analysis of Dallas and Amarillo offers a nuanced understanding of the impact of local context on the provision of refugee services. The research contributes to academic knowledge in the fields of migration, organizations, and the state, and has practical implications for policymakers, ISO workers, advocates, and scholars in Texas and beyond.
Magnetoresponsive Layer-by-Layer (LBL) Polyelectrolyte Microcapsules Exposed to Low Frequency Alternating Magnetic Field for Drug Delivery to Breast Cancer Cells
Layer-by-layer (LBL) polyelectrolyte capsules can be modified to incorporate stimuli such as superparamagnetic nanoparticles which respond to a magnetic field only when it is turned on. Thus, they can act as a switch to load or unload their drug cargo on demand. Specifically, magnetite is incorporated into bilayer capsules made of alternating poly(allylamine hydrochloride) (PAH) and poly(sodium-p-styrenesulfonate) (PSS) which surrounds calcium carbonate core. The core is then dissolved using ethylenediaminetetraacetic acid (EDTA). These capsules are loaded with at FITC-BSA conjugate and examined with fluorescence to show the unloading of the FITC-BSA from capsules as it brightens the entire field of view of the microscope. The results suggest that we can next load and unload an anticancer drug such as doxorubicin using the combination of microcapsule and alternating magnetic field (AMF) to treat the cancer cells. Preliminary data interprets that the low frequency AMF we use has little to no adverse effect cells viability. This coincides with the general thought that low frequency AMF signals are not harmful to humans. Therefore, as an alternative to hyperthermia methods which use heat, it may be possible to deliver the anticancer drugs specifically to the cells when and where it is needed.
Memories of Troy in Middle English Verse: A Study of "Sir Gawain and the Green Knight," "Troilus and Criseyde," and the "Troy Book"
This thesis explores the influence of the legend of Troy on Sir Gawain and the Green Knight, Chaucer's Troilus and Criseyde, and Lydgate's Troy Book. This study seeks to understand why medieval English Christians held the pagan myth of Troy in such high regard beyond the common postcolonial critique of Trojan ancestry as a justification for political power. I begin by demonstrating how Vergil's Aeneid presents a new heroic ideal much closer to Christian virtue than Homeric values, Aeneas submitting his will to fate and earning his piety through suffering. I then turn to Sir Gawain and the Green Knight, assessing how Gawain is not only descended from Aeneas but how the major events of his quest echo Aeneas' journey, especially in both heroes' submission of their wills to fate. Next, I reveal how Chaucer's Troilus enacts a platonic ascent from a state of ignorance to a state of truth, but as Troilus' name is also linked to the city of Troy itself, the fate of Troilus becomes the fate of Troy. In this way, Chaucer dramatizes the spiritual ascent of his Trojan ancestors in that they move from sin to salvation as a culture. Finally, I investigate how Lydgate refashions Troy into an earthly manifestation of Augustine's City of God. In doing so, Lydgate not only remembers his people's past but prophesies the fate of Trojan descendants. Such an analysis helps late antique and medieval scholars understand not only why such classical myths were popular in a predominantly Christian era, but also how the legends of Troy gave medieval English society a myth-history through which to dramatize their spiritual lives.
Mesenchymal Stem Cells Encapsulated and Aligned in Self-Assembling Peptide Hydrogels
This study presents a viable strategy using fmoc-protected peptides hydrogels, to encapsulate and stretch mesenchymal stem cells (MSC). To explore the peptide hydrogel potential, a custom mechanical stretching device with polydimethylsiloxane (PDMS) chambers were used to stretch MSCs encapsulated in Fmoc hydrogels. We investigated the impact of fmoc- FF prepared in dimethyl sulfoxide (DMSO), 1,1,1,3,3,3-hexafluoro-2-propanol (HFP) and deionizied water in the self-assembly, and mechanical properties of the gels. The peptide hydrogel is formed through molecular self-assembly of peptide sequence into β-sheets that are connected with the π-π aromatic stacking of F-F groups. The hydrogels provided a stiff, hydrated gel with round nanofiber morphology representing an elastic modulus of 174-266 KPa. MSCs cultured on peptide hydrogels undergo viability, morphology, and alignment evaluations using MTT, live/dead, and phalloidin (F-actin) staining. The F-actins of 3D- cultured MSCs in Fmoc-FF/HFP, and Fmoc-FF/DMSO followed by mechanical stretching showed elongated morphology with defined microfilament fibers compared to the round and spherical F-actin shape of the control cells. Peptide gels with 5mM concentration preserved 100% viability of MSC. Results reveals the feasibility and conditions for successful cell encapsulation and alignment within peptide hydrogels. Encapsulation of MSC in peptide nanofiber followed by a stretching process present a promising tissue engineering platform. By enhancing our understanding of MSC-peptide hydrogel interactions, this research con- tributes to the development of biomaterials tailored for regenerative medicine.
Metal Nitride Complexes as Potential Catalysts for C-H and N-H Bonds Activation
Recognizing the dual ability of the nitride ligand to react as a nucleophile or an electrophile – depending on the metal and other supporting ligands – is a key to their broad-range reactivity; thus, three DFT studies were initiated to investigate these two factors effects (the metal and supporting ligands) for tuning nitride ligand reactivity for C-H and N-H bond activation/functionalization. We focused on studying these factors effects from both a kinetic and thermodynamic perspective in order to delineate new principles that explain the outcomes of TMN reactions. Chapter 2 reports a kinetic study of C–H amination of toluene to produce a new Csp3–N (benzylamine) or Csp2–N (para-toluidine) bond activated by diruthenium nitride intermediate. Studying three different mechanisms highlighted the excellent ability of diruthenium nitride to transform a C-H bond to a new C-N bond. These results also revealed that nitride basicity played an important role in determining C–H bond activating ability. Chapter 3 thus reports a thermodynamic study to map basicity trends of more than a one hundred TMN complexes of the 3d and 4d metals. TMN pKb(N) values were calculated in acetonitrile. Basicity trends decreased from left to right across the 3d and 4d rows and increases from 3d metals to their 4d congeners. Metal and supporting ligands effects were evaluated to determine their impacts on TMNs basicity. In Chapter 4 we sought correlations among basicity, nucleophilicity and enhanced reactivity for N–H bond activation. Three different mechanisms for ammonia decomposition reaction (ADR) were tested: 1,2-addition, nitridyl insertion and hydrogen atom transfer (HAT). Evaluating nitride reactivity for the aforementioned mechanisms revealed factors related to the metal and its attached ligands on TMNs for tuning nitride basicity and ammonia N–H activation barriers.
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