Electronic Theses and Dissertations

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About: Electronic theses and dissertations (ETDs) are the graduate research outputs of Texas Tech University. They represent years of work from our Master's and Doctoral graduates. If you find the ThinkTech digital repository useful, please tell us! Share how open access to scholarship benefits you. Your story matters to us.

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Now showing 1 - 20 of 24278
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    3D Printed Microfluidics for Cancer Cell Isolation and Sepsis Detection
    (2023-05) Yang, Yijia
    Microfluidic cell separation techniques have gained significant attention in the field of clinical analysis due to their ability to perform high-throughput separations on small sample sizes. The use of microfluidic separation in clinical analysis offers several advantages, including the ability to perform high-throughput separations with small sample sizes, high sensitivity and specificity, and low cost. These benefits make microfluidic separation a promising tool for the advancement of clinical analysis and disease diagnosis. In this dissertation, Chapter I discusses the detailed fundamentals introduction of microfluidics. Chapter II and Chapter III present the studies of biomarkers used for cancer cells isolation and the application combined with affinity 3D printed microfluidic devices. Chapter IV discusses the study of biomarkers used in the early detection of sepsis and the application combined with 3D printed multi-zone microfluidic device in a clinical study. In Chapter V, the conclusion and prospects for the future are discussed. Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells. Cancer cells typically grow quickly, are immature, and are unable to carry out the duties of healthy cells. The mortality of cancer patients will decrease if the cancer prognosis can be identified early (before a disease starts to metastasis). The selection of a biomarker for early cancer detection is crucial. In Chapter II and Chapter III, CD71 and EpCAM are used as cancer biomarkers with our 3D printed microfluidic device to isolate cancer cells. Capture purity and enrichment factor are being studied, in Chapter II, clinical cancer cells were spiked into blood and isolated with breast cancer samples having a purity of 93 ± 6% to 94 ± 10% and an enrichment factor of 1860 ± 120 to 1890 ± 190 and acute lymphoblastic leukemia samples having a purity of 90 ± 10% to 96 ± 7% with an enrichment factor of 1793 ± 200 to 1920 ± 140. The severe and sometimes fatal condition known as sepsis is brought on by an unchecked immunological reaction to infection. Sepsis must be identified and treated as soon as possible to lower the risk of serious consequences and enhance patient outcomes. In Chapter IV, we present a 3D multi-zone microfluidic device provided high sepsis capture purity and high enrichment factor. Anti-CD25, anti-CD64, and anti-CD69 were used as affinity cell capture biomarkers. The performance of our 3D printed multi-zone microfluidic device was assessed in this study, which included 35 septic patients and 10 healthy volunteers. With an AUC of 0.992, we discovered that our combination of anti-CD25, anti-CD64, and anti-CD69 antibodies worked well together to detect sepsis. According to the clinical validation, our multi-parameter microchip provides a potent sepsis assay for clinical point-of-care (POC) applications.
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    Identity and Contemporary Media: Neomedieval and Neo-Renaissance Conceptions of Morality in Popular Culture
    (2023-05) Rogers, Jessie
    This dissertation argues that neomedieval and neo-Renaissance texts are capable of infusing adaptations with progressive and accepting views on inclusivity along the lines of race, gender, sexuality, and disability in ways that allow such adaptations to better reflect the moral complexity of contemporary audiences. I explore how such adaptations showcase and respond to a continued interest in the early British and early modern while also expanding the traditional intended audience of such texts to include those who have historically been and currently remain on the margins of society. In doing so, such texts reflect an increasingly diverse world in ways which include the excluded, encourage privileged readers to engage with other perspectives, and impact our ongoing definitions of good and evil and heroism and villainy. Explorations of complex morality and the liminal space between a strict binary of good and evil have grown as the popularity of antiheroes and anti-villains has increased. In response, this study considers the significance of that liminal space for those whose less-than-savory actions are a means of fighting oppression, and it asks what kind of impact characters from marginalized communities have on our moral binaries and their increasing fluidity. Thus, this argument is responding to several ongoing conversations regarding sociocultural identities and their representations in popular culture, morality in popular culture, heroism and villainy in medieval and Renaissance texts, and the impact of medieval and Renaissance texts and culture on modern media. Specifically, this dissertation works to combine those conversations, signifying for scholars, creators, and audiences where popular culture is heading by exploring the ways in which identity and representation are used to modernize older texts, characters, and tropes for an audience that is increasingly interested in the navigation of complex moral problems as opposed to simplistic victories of good versus evil; essentially, including diverse identities as the basis of these narratives asks us to question what good and evil even mean, who has conventionally been assigned those labels, and to what extent such rigid labels are still functional in today’s world. Using comparisons between medieval poetry, Renaissance poetry and drama, manuscript images and contemporary comics and film, this dissertation traces the changes modern media makes to older sources and what they choose to maintain, positing that maintenance connects us with past cultures while change better connects the diverse communities of our current and future cultures. Using race, gender, queer, and disability applications when adapting the medieval and the Renaissance acknowledges the harm that bigotry done to a number of communities while reshaping beloved genres and narratives to form new access points for audience members within those communities.
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    A Case Study Using Q Methodology to Explore the Attitudinal Orientation of High Plains Sorghum Producers Toward Sustainable Agricultural Practices
    (2023-05) Erramouspe, Haleigh
    In September 2022, National Sorghum Producers (NSP) was awarded a $65 million grant from the USDA Partnerships for Climate-Smart Commodities program to finance a pilot project focused on implementing climate-smart practices on sorghum acreage. NSP was then tasked with developing a strategic and comprehensive communications plan to disseminate information about this program and persuade producers to participate. The purpose of this study was to utilize Q Methodology and the Elaboration Likelihood Model to explore the attitudinal orientation of sorghum producers toward agricultural sustainability and evaluate best practices for message delivery. An online survey was distributed to sorghum producers in the High Plains through which information was gathered regarding agricultural sustainability perspectives, current levels of implementation of sustainable agricultural practices, and willingness to adopt new sustainable agricultural practices. Results showed that sorghum producers fell into one of three categories of attitudinal orientation: A) producers concerned about the profitability of implementing sustainable agricultural practices with low levels of current implementation and willingness to adopt new practices, B) producers invested in the long-term sustainability and productivity of their farmland with high levels of current implementation and willingness to adopt new practices, and C) producers despite holding strong beliefs that sustainability was necessary to maintain the productively of their property and having high levels of current implementation and willingness to adopt new practices, also expressed strong concerns about the financial viability of adopting sustainable agricultural practices. Implications from this study reveal a need for NSP to develop messaging about the connection between profitability and agricultural sustainability and financial risk mitigation into all communications regarding program participation.
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    The Economic Impacts of Geopolitical Risk
    (2023-05) Alsubaie, Mohammed S.
    The purpose of this dissertation is to investigate the impact of the geopolitical risk shocks on the economy. The first chapter of this dissertation investigates how the geopolitical risk could affect macroeconomic variables of the United States. The second chapter studies the impact of the geopolitical risk on the aggregate and sectoral US employment. The third chapter studies the impact of geopolitical risk with various uncertainty proxies on the US economy.
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    Rural Creative Placemaking: A Mixed-Methods Field Experiment on Community-Led Public Art Placemaking, Place Attachment, and Sense of Community
    (2023-05) de la Plaine, B. Tyler
    This study explored community-led public art placemaking as a potential rural revival strategy by approaching the problem of rural decline through a human ecological lens. As exploratory research, this study examined the ways in which an ephemeral process of resident-led, public art placemaking influences residents’ sense of community and place attachment dimensions. As an early winter storm swept through a rural Colorado mountain town, participants created artworks in the town’s pocket park. Objective: This research explored gaps in the literature on how a public art placemaking process (as an instance of creative placemaking) influences residents’ place attachment and sense of community. Additionally, the study provides empirical evidence and recommendations on how policy toward rural revival can be informed with place attachment and sense of community concepts as part of a rural revival top-down strategy. Furthermore, this study illuminates ways in which bottom-up community strategies formulated with community and place attachment values strengthens community and place bonds. Method: In this mixed-methods longitudinal field experiment, randomly selected resident participants took part in a public art-making experience. Sense of community index and a six-dimensional place attachment index were used to measure the multidimensional influence of the art-making process. Additionally, field notes, photography, video, post-intervention interviews, and textual surveys captured rich qualitative data. Concurrent triangulation was used in the analysis wherein quantitative data offered evidence of the strength of the relationships while the qualitative data added rich details regarding the relationships. Findings and Results: The art-making intervention participants experienced overwhelmingly positive place memories, place expectations, and community sentiments wherein participant reflections described the event as a catalyst and galvanizer toward place change. Moreover, compelling qualitative findings and statistically significant results of increased community influence, fulfillment, and overall sense of community were found. Theoretical implications of temporal construct processes and practical inferences are discussed, including a town’s potential as a culturally built environment, to foster positive human relationships and strengthen community bonds. Conclusions: Public art, as community-led placemaking, shows promise as a viable rural revival strategy and mechanism for increasing residents’ community bonds and optimism toward what is possible in shaping their towns into more attractive places to live.
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    Associations Between the Home Physical Environment Factors and Child Self- Regulation
    (2023-05) Bagais, Reem
    The environment is an important external source that affects a child’s cognitive, behavioral, mental, and social development. According to the Bronfenbrenner ecological system model, the interaction between a child and his/her environment can influence and shape the development of self-regulation. A child’s home is part of a complex microsystem referred to as the immediate environment, consisting of different factors such as family income and a chaotic home environment. There is very little research addressing physical environmental factors in low-income households and how these factors affect children’s self-regulation. Method: This research qualitatively explores the home physical environment in relation to child self-regulation. The current research builds a framework that ties together theories on environmental design and establishes a relationship between the physical environment and a child’s ability to self-regulate and manage stress. Data were collected through surveys, interviews, and on-site observation, and included participants from three different income levels (upper =2, middle =2, and lower =6) with diverse ethnicities. Findings: Thirty-nine environmental factors were derived from parents/caregivers' perspectives. The key findings of the study include: (1) the more the affordances aspects in the environment, the better for the child's self-regulation; (2) spatial factors of the environment influence the child's self-regulation negatively and positively; and (3) there are few variations between income levels in relation to home environmental factors that impact child self-regulation.
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    Two Essays on Understanding Commercial Banks
    (2023-05) Tran, Anh
    Small community banks are different from large, national banks in both the way they operate and the values they provide to their communities. My first essay is about how small and large bank managers have different motives behind managing their loan loss allowances and loan loss provisions. Bank managers have the ability to exercise their discretion in determining loan loss allowances and loan loss provisions, which directly increase or decrease reported earnings. The existing literature suggests different managerial motives behind adjusting loan loss allowances (LLAs) and loan loss provisions (LLPs) upward during good financial and economic periods. Using a digital analysis method based on Benford’s law, I analyze rounding patterns in LLAs in good and bad times. I partition my bank samples based on net income, profitability, bank size, regulatory level, and whether the banks are private or public. My results are consistent with previous studies which argue that managers of small banks make discretionary adjustments to LLAs and LLPs for non-opportunistic motives including signaling, reducing pro-cyclicality, and improving efficiency. My second essay is about how banking relationship, a community bank feature, may help overcome lending outcome discrepancies between different demographic groups of borrowers. First-time minority borrowers tend to receive less desirable outcomes than first-time white borrowers. This is partly due to having less credit risk information for lenders to gather. By using soft information about new borrowers, relationship lenders can draw insights into the borrowers’ creditworthiness without the need of an existing bank-borrower relationship. Because of that, relationship lenders can benefit new minority borrowers by alleviating imperfect information and lending discrimination problems. In this study, I show that borrowing from a relationship lender reduces lending outcome discrepancies between new minority borrowers and new white borrowers. Besides loan acceptance rates, discrepancies in borrower’s perceptions, which include satisfaction level and the likelihoods of facing borrowing challenges, are also reduced. These results suggest that borrower’s soft information is an important part of relationship lenders’ decision making process.
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    The Emotional Generation of Whiteness and Order in the Spanish Texas Frontier
    This thesis examines a process of maintaining white hegemony in Eighteenth-century Spanish colonial Texas. The culmination of centuries of concerns over religious purity and ethnic hierarchies were met in Spanish Texas with a geo-political environment created by Indigenous power. As the Spanish invaded Texas, they brought these passions and ideologies with them, morphing them into a defense strategy for protecting an emotional territory—a protection of colonial order in the face of Indigenous domination. Generating a sense of governance based on sophistication came from a place of fear. Generations of Hispanic settlers understood Indigenous blood as a conduit for evil, and maintaining Texas as a province became a territorial struggle against enemy imperialists and Texas Indians, but also against threats to white supremacy and the spiritual well-being of the settler population. In light of this, ethnic differences were supported by disparate treatment under the law, as well as patterns of consumption. In this environment, proximity to Spanish ideals of civilization was signaled through settlers’ ability to abstain from Indigenous lifeways and foodways. Elite Spanish settlers in Texas used the degree of quality in chocolate as one of very few mechanisms for communicating their supposed superiority. Chocolate can be seen as a lens into the ways these processes unfolded in Spanish Texas frontier society. This frontier was governed in part by the relationship between white male entitlement and paranoia.
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    Snack product development for malnourished and low-income children and women in South Africa
    (2023-05) Ibiyemi, Temitope
    The high consumption of unhealthy snacks is linked to the prevalence of undernutrition, overnutrition, and several non-communicable diseases (NCDs) in South Africa. Notably, energy-dense, nutrient-poor snacks, which are often cheaper than healthy snacks, are frequently consumed by malnourished children and women in low-income communities. The frequent consumption of these nutrient-poor snacks can displace the consumption of healthy foods and drive the prevalence of under and overnutrition. Aim: The first aim of this study was to conduct a snack frequency consumption survey among children and women in South Africa. The second aim was to develop ten affordable and nutrient-dense snacks that are lower in saturated fats, sodium and added sugars than those available in the market. Our third aim was to determine consumer acceptability and evaluate the sensory attributes of the developed snacks among children and women in South Africa. Methods: A snack consumption survey was conducted among 90 children and 69 women in the Vaal region of the Gauteng province in South Africa. Children and women were recruited from schools and community centers in the Gauteng province. Snack consumption frequency was assessed using prevalidated questionnaires. The snacks were developed to ensure the nutritional profile of the snacks was consistent with recommendations from the Food-Based Dietary Guidelines for South Africa (FBDG-SA) and the South African Heart Association (SA Heart). Consumer sensory evaluation with the likelihood to prepare and purchase the snacks was conducted. Ninety-seven panelists (adults 18 years and older) completed the JAR evaluation at the University of the Free State (UFS) Sensory Lab, while 143 children and women completed the consumer sensory analysis. The Excel: XLSTAT Sensory software was used for the data analysis of the sensory evaluation results. Whereas descriptive and inferential statistics were performed using R version 4.1.2. for data analysis. Results: The snack consumption frequency showed that most children (68.2%) and about half of the women (48.3%) consumed snacks at least once a day. Children frequently consumed more potato chips (p= 0.015), corn chips (0.017), cheese curls (p<0.001), and muffins (p= 0.008) than women. In contrast, women consumed more savory biscuits (p= 0.027) and biltong (p= <0.001) than children, but there were no significant differences in the consumption of the other 15 identified snacks assessed. The developed snacks – soy carrot muffins, soy cookies, nut and seed brittles, soy popcorn brittles, protein bars, soy rusks, and four trail mixes - were primarily formulated from soy and soy ingredients. The nutritional profile of the snacks showed they contained at least 15g/100g of protein and ≥6g/100g of dietary fiber aside from soy rusk with a dietary fiber content of 4.19g/100g. Likewise, all the snacks had a sodium content of ≤120mg/100g and an added sugar content of ≤10g/100g, except for the two brittles, with a sugar content of 12.1 - 13g/100g. However, all the snacks were at least 25% higher in protein and dietary fiber content and at least 25% lower in sodium, added sugar, and saturated fat than the corresponding snacks in the South African market. Overall, the sensory evaluation results showed the snacks were liked with an average mean score of 4.0 out of a 5-point hedonic scale for overall acceptability, except trail mix 1 - neither liked nor disliked by children. Women significantly liked soy rusk (p= 0.03), nut and seed brittle (p = 0.03), and trail mix 1 (p = 0.001) more than the children. Furthermore, the women indicated a likelihood to prepare and purchase all the snacks (mean score of 4.0 out of 5-point Likert scale), aside from trail mix 3, which panelists were neither likely to prepare nor purchase. Conclusion: This experimental study developed high-protein, high-fiber snacks that were more nutritious than corresponding snacks in the market. The findings suggest the consumer acceptability of nine healthy soy-based snacks, while panelists were indifferent to a snack – the trail mixes with seeds. Future research should focus on utilizing these snacks as part of sustainable nutrition intervention strategies to address malnutrition. In addition, clinical trials should be conducted to investigate the effect of soy-based snack consumption in improving nutrition status.
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    Association of Nutrition Knowledge, Attitudes, Beliefs and Practices with Cardiometabolic Diseases Risk Factors among Adults
    (2023-05) Najam, Wasiuddin
    Aim: Adults living in the Free State province of South Africa have a high prevalence of cardiometabolic diseases (CMD) risk factors. Therefore, to decrease the prevalence of CMD risk factors, it is important to improve adult’s nutrition knowledge, attitudes, beliefs, and practices (NKABP) towards healthy eating, which have to the potential to lead to a healthier eating patterns and reduced risk for CMD. Tailored nutrition education interventions are necessary to improve CMD risk factors. To develop effective nutrition education interventions to improve CMD risk factors understanding the association between NKABP and CMD risk factors among adults is important. Therefore, the aim of this study is to assess the association between NKABP and CMD risk factors among adults in the Free State province of South Africa. Method: This sub-study forms part of the Assuring Health for All in the Free-State, which is cross-sectional study conducted in both urban and rural areas of the Free State province of South Africa. A total of 586 adults aged 25 - 65 years old without CMD were included in this sub-study. To assess the association between NKABP and CMD risk factors Spearman’s correlation test was used. Fisher’s exact test was used to evaluate the differences in NKABP between adults with normocholesterolemia and hypercholesterolemia, normal serum glucose (GLU) and impaired/high serum GLU, normal and high blood pressure (BP) and among body mass index (BMI) categories. Results: In this study, 77.1% were women with the majority of adults belonging to the Black race (81.5%). Almost half of the participants had no or primary school education (54.4%) and 55.7% had income levels below < ZAR1000 (~ $130 US). Our findings demonstrated that nutrition knowledge (NK) was significantly and positively correlated with triglycerides (TG) and systolic and diastolic blood pressure (BP). However, only a higher proportion of adults with hypertension had good levels of NK. There was a significant positive correlation of nutrition attitudes (NA) with serum GLU, while only a higher proportion of adults with overweight/obesity had good levels of NA compared to those with normal weight. With regards to nutrition beliefs (NB), there was significant and positive correlations of NB with low-density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), TG, serum GLU, HBA1c, body mass index (BMI), and waist circumference (WC), however, only those with overweight/obesity had significantly higher proportion of adults with good levels of NB. Finally, there was a negative correlation between nutrition practices as measured by dietary diversity score (DDS) and HDL-C, while DDS was positively correlated to LDL-C, TG, GLU, HBA1c, BMI and WC. Only those adults with hypercholesterolemia had significantly higher proportion of adults with high DDS compared to those with normocholesterolemia. Conclusion and recommendations: The overall positive and negative correlations of NKABP with CMD risk factors in this study indicates that an increase in NKABP occurs with an increase in CMD risk factors among adults in the Free State province of South Africa. Therefore, it is important to implement preventative and tailored nutrition education interventions that focus on adults to improve their NKABP towards a healthy dietary pattern, which has the potential to prevent the development of CMD risk factors.
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    A Biographical Narrative Inquiry into the “Mundos” of Two Hispanic Families with an English-Speaking Child with Autism Spectrum Disorder
    (2023-05) Cirlos, Ubaldo Jr.
    This study aims to explore the lived experiences of Spanish speaking families with students who have Autism Spectrum Disorders (ASD) and only speak English because of subtractive bilingual programs or English-only instruction. The central question of this narrative inquiry was: What are the lived experience of families with an English only speaking children with Autism Spectrum Disorder whose home language is Spanish? The study used a hermeneutical phenomenological lens to explore the mundos [worlds] of two families with a child with ASD that is an English learner and understand their experiences. Their experiences were presented through a biographical narrative inquiry analyzed using Polkinghorne’s method of narrative configuration. The findings shed light on their beliefs and struggles due to the children’s native language being subtracted from their education. Additionally, an unexpected finding on how high school foreign language classes made a world of difference in their ability to communicate in their native language. Through the understanding of their mundos [worlds] of the participants. It is the researchers hope that the social validity of additive bilingual programs increases.
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    Clothing Fit and Self: An Empirical Examination of Fit Factors and Self Evaluation Related to the Confident Clothing Decision and Psychological Well-Being
    (2023-05) Hossain, Md. Jakir
    Consumers’ body image and perception of comfort are closely related to garment fitting, a primary factor in evaluating clothing performance and body comfort. This study uses self-discrepancy theory to examine how fit characteristics (fit preference and performance) affect consumers’ self-evaluations (self-schema, body satisfaction, and self-esteem) and psychological responses (confident clothing decisions and psychological well-being). Non-probability quota sampling was used for the quantitative research approach. A total of 502 data was collected, and SPSS and partial least squares structural equation modeling (PLS-SEM) was used to analyze the data. The results of this study demonstrate that self-discrepancy mediates the relationships among self-schema, self-esteem, and body satisfaction, during consumers’ self-evaluation process and links up the influence of fit factors on their psychological responses. Additionally, Pearson χ2 tests and post hoc analysis confirmed a significant relationship between body characteristics (body size, shape, BMI) and fit preferences. Finally, the theoretical and practical implication of this study was presented.
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    Developing Machine Learning Tools for Quantitative Analyses of Biomedical Images
    (2023-05) Yosofvand, Mohammad
    Biomedical and pathology images have a significant role in medical and research applications in both diagnosis and disease treatment. With the evolution of digital scanning tools, increasing computing power, and deep learning tools, it is necessary to provide researchers with accurate, fast, and user-friendly tools that can be used in clinical and research applications. In this dissertation, we applied these tools to two biomedical areas and diseases: the first is obesity by studying adipose tissue histology images; the second is breast cancer by studying tumor histology slides. First adipose tissue images were analyzed using the AdipoGauge software that we developed. This software can detect adipose cells, count them, and calculate the area of all cells very accurately. It also can find areas of interest in adipose tissue and calculate the required data for research purposes such as cell size and cell number in different biomedical slides. AdipoGauge contains different analysis tools such as object removal, bordering cell detection, and cell size categorization which makes the analysis process more accurate. We demonstrated that the results from the AdipoGauge software were more accurate than similar software such as ImageJ. Next, the framework of the AdipoGauge was used to develop a new tool for quantitative analyses of breast tumor histology images. Detection of the Tumor Infiltrating Lymphocytes (TILs) in cancer images has gained significant importance as it can be used as a biomarker to guide cancer detection and treatment. Based on the guidelines from the International Immuno-Oncology Biomarker Working Group (IIOBWG) on Breast Cancer, we labeled 63 large pathology imaging slides and annotated the TILs in the stroma area to create the dataset required for model development. A U-Net deep learning model was employed and trained for different parameters to achieve the highest accuracy possible which is 98% accuracy in the stroma detection task. The segmented stroma images then were used to implement the Mask R-CNN model for the TILs detection task. The R-CNN model detected the TIL cells in different images and was used as the backbone analysis network for the GUI development of the TILs detection tool. In conclusion, we developed sophisticated machine learning tools and software that will assist researchers and clinicians in rapid and accurate analysis of histology and pathology slides, which will help future research and/or treatment strategies.
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    Legal Practices and their Implication for Women and Children in Eighteenth-Century Ottoman Tripoli: A Social and Economic Perspective
    (2023-05) Rafei, Reda Z.
    The field of Ottoman history witnessed an increased scholarly interest and a burst of peer-reviewed publications in the past two decades. This change in the course of the field resulted from the emergence of an incredible wealth of primary sources in the modern states that were part of the Ottoman Empire. It also resulted from new trends in historical research, bringing to the forefront the writing of economic and social history ‘from below’, and focusing on social groups, like women, children, and non-Muslims, who were neglected in the literature for a long time. This dissertation studies gender dynamics within the Middle Eastern family and society in eighteenth century Ottoman Tripoli (in modern day Lebanon). Notwithstanding the fact that they lived in a male dominated society, I show that women enjoyed the support of their natal families and strategized to maneuver through marital bonds and dissolutions. Drawing on an array of sources, ranging from court registers to estates inventories and fatwa (religious opinion) collections, I argue that, long before the age of modernization that accompanied the western infiltration in the nineteenth century, women had a noticeable presence in the public domain and an evident contribution to the, largely, agrarian economy. I demonstrate that women had legal rights to their dowries and inheritance which formed the cornerstone of the resources they had at their disposal. This agency in financial matters sometimes translated into more flexibility and freedom in personal and matrimonial affairs. I also take a closer look at the act of establishing waqfs (religious endowments). I argue that female Tripolitans used this charitable mechanism to maximize their profits, protect their financial interests during their duniya (lifetime), and fulfill their dīn (religious) duties to be rewarded in the hereafter. One objective of this study is to debunk the assumptions that continue to dominate the minds, and scholarship, of western, and some Middle Eastern, researchers about the subjugation of women, which is often blamed on Islam and its institutions. Using the court records to document the presence of Muslim and non-Muslim women in the public sphere, I demonstrate that they were by no means marginalized members of their society. Moreover, the evidence shows that women relied heavily on the Islamic legal system of the Ottoman government. When they had a lawful claim, the law supported their rights as property owners and their prerogative to decide on matrimonial union and issues related to divorce settlements and rights to custody of children. The evidence also shows that the legal system demonstrated flexibility to circumvent scriptural rigidity and allowed women more ‘social maneuverability’.
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    A life cycle of volcanic ash from the example of micro- and macro-scale investigation of Miocene tuff layers from the Dinarides
    (2023-05) Badurina, Luka
    Tuffaceous layers are regularly preserved in Miocene carbonate and siliciclastic sediments of the broader Alpine region of southeastern and central Europe. Detailed mineralogical and geochemical analyses of 13 tuffs of known ages acquired from sedimentary successions of intramontane Dinarides basins and the southwestern Pannonian Basin were carried out to infer on plausible source areas, relative strengths of volcanism, and ash distribution patterns. Studied tuffs were altered to various degrees with illite-smectite and smectite as dominant phases while volcanic glass, carbonates and other silicates are minor constituents. Tuffs’ geochemistry ranges from andesitic through trachyandesitic to rhyolitic and trachytic. Trace-element based correlation with regional data reveal that Lower Miocene (LM) and Lower Middle Miocene (LMM) tuffs (17.0–14.0 Ma) likely originated in the Western Carpathians (the Bükkalja volcanic field) while the source areas of Upper Middle Miocene (UMM) tuffs (13.8–12.5 Ma) were in the Apuseni Mountains and/or Eastern Carpathians. The spatial relation of LM/LMM and UMM tuffs with respect to their source areas (the Bükkalja volcanic field and Apuseni Mountains, respectively) is most consistent with tropospheric easterly trade winds that carried ash hundreds of kilometers to the SW toward an azimuth of c. 200–250°. Many tuffs from the Dinarides Lake System (DLS) are affected by various extents of volcanic glass shard alteration. A selected ~14.68 Ma felsic tuff from DLS Livno-Tomislavgrad Basin that was found to exhibit volcanic glass degradation and co-genetic Mn-Fe precipitation was studied. Microbial activity took part in both reactions thus adding the interest of revealing effects of biotic and abiotic processes occurring during tuff eogenesis. X-ray diffraction and electron microbeam analysis with energy-dispersive X-ray spectroscopy revealed the pitting or granular structures developed at glass rims along with smectite flakes protruding from a degrading glass. Mn-Fe mineralization emerges in the form of Mn-Fe coatings, an initial step to micronodule formation, where traces of biogenetic influence included a high content of phases rich in structural Mn(IV) (i.e., ranciéite and jacobsite) and presence of microbial microfossils. Co-genetic ties between glass degradation and Mn-Fe precipitation were established through the report of dioctahedral smectite formed at the expense of altered glass which then served as nuclei of the ongoing biotic and abiotic Mn-Fe mineralization. These processes manifest on a continuous involvement of microbial life in the course of eogenesis of pyroclastic material in lacustrine environment. The final contribution of this doctoral dissertation reports a novel approach in the study of trace-element mobility during argillitization of volcanic glass that is based on in situ laser ablation inductively coupled plasma mass spectrometry glass analyses and that of spatially related illite-smectite collected in the form of fraction separates. The material studied originates from lacustrine sediments of the DLS that bear evidence of intensive weathering of distal tephra during the Miocene climatic optimum. Yttrium and HREE were probably mobilized from decomposing glass in the form of carbonate complexes and were consequently depleted significantly in studied clays. On the other hand, the Mg-rich illite-smectite demonstrates an elevated adsorption potential of solvated LREE complexes. This may be explained through the clay surface geochemistry controlled largely by Mg for Al octahedral substitution. This contribution highlights the role of eogenetic 2:1 clay aluminosilicates that, under favorable geological conditions, may be conducive to secondary REE enrichment and the formation of potential ion adsorption-type deposits. Finally, preliminary analysis of correlating specific surface area measurements of separated clay fractions with their corresponding REE mobility patterns is considered as a potential avenue for future work on this topic.
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    Chinese, British, and American Interactions in the Canton Trade, 1784-1860: Changing Imperial and National Relations in the “Contact Zone” of Canton
    (2023-05) Beard, Joseph
    After the American Revolutionary War and independence from Britain, merchants from the new United States of America (US) were quick to begin trading with China. As Americans sailed into uncharted waters (for them), they sought to make money and prove their nation in competition with European empires, particularly Britain. The China trade they entered was solidly controlled and strictly regulated by the Qing Dynasty which had limited all foreign oceanic trade to the city of Canton (Guangzhou) and with a select group of Chinese “hong” merchants. My argument is that during the period of 1784 to 1860, attempts by the still robust Qing Dynasty, increasingly powerful British Empire, and new nation of the US to gain more control of the China trade through imperial and national systems was often met with unexpected consequences due to human elements in the accommodation and collaboration between Chinese and foreigners in the “contact zone” of the Canton Trade. By looking at a series of events in the China trade—from the Lady Hughes Incident in 1784 through the Second Opium War ending in 1860—and the shifting relations between Chinese, British, and Americans involved in the trade (including internal disagreements), the impact on commercial trade and diplomatic relations can be seen, as well as the effect of growing European imperialism. By the 1830s, deteriorating relations in the Canton Trade led to war as Western imperialism grew in Asia. As the rigid, impersonal, and strategy-driven imperial and national systems of China, Britain, and the US became more centralized, the ability of businessmen and merchants on the ground in Canton to flaunt the rules to ensure continuous trade was stymied as official diplomatic relations and the trading protocols dictated by them were forced upon China by an increasingly imperialistic West.
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    The Role of Photograph Aesthetics in Wine Tourists’ Decision Making
    (2023-05) Alimohammadirokni, Mohammad
    This study aims to investigate the impacts of amateur and professional photograph aesthetics found in Google reviews on wine tourists' attitudes, perceptions of the source's credibility, and visit intentions throughout the information search phase using a Stimulus- Organism- Response framework. A secondary goal is to investigate the impact of individual characteristics (i.e., risk-taking propensity and involvement) and contextual cues (i.e., reliance on reviews) as moderators on the relationships mentioned above. An online survey questionnaire was utilized to collect data from 703 participants residing in the U.S. SPSS and PLS-SEM were used to analyze the data. The findings showed that photograph aesthetics had a significant and positive relationship with perceived credibility, visitors' attitudes toward wineries, and visit intentions. The perceived credibility of the source played a key role in the decision-making process, influencing a person's attitudes toward a winery and their intentions to visit. Attitude toward a winery also positively impacted visit intention. The role of reliance on reviews, risk-taking propensity, and involvement was not confirmed as moderators. The multi-group analysis technique showed significant variations between the professional and amateur aesthetics with respect to the effect of aesthetics on credibility, aesthetics on attitude, attitude on visit intention, and the moderating effect of risk-taking propensity on the relationship between perceived credibility and visit intention. The effect was stronger in the professional aesthetics group in all these relationships. The current study contributes to the literature on electronic word-of-mouth communication (reviews), online marketing, photo aesthetics, and behavioral models of wine tourism. It also adds to the knowledge on the impact of message type in an online setting in the tourism industry. The present study's findings have significant practical implications for wineries that utilize websites and social media to interact with customers, advertise their wines and services, and promote their brands. The current study's findings will also provide important implications for winery managers regarding which photos they should focus more on online platforms to attract more visitors, increase sales, and remain competitive. The study results will also provide insights for marketers and managers in the wine industry to develop better marketing strategies. Finally, this study's findings can be applied to other settings such as restaurants, hotels, and tourism destinations.
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    The influence of particle size on the fluid dynamics of a laser induced plasma
    (2023-05) Miller, Clayton
    The work reported herein was published in Physics of Fluids 34, 053312. The interaction of a laser-induced shock wave with nanoparticles and microparticles of aluminum oxide is investigated through experiments and modeling. The chemistry and physics of the interaction between the particles and plasma generated from laser ablation shows similarities and discrete differences for the two particle sizes. For both particle sizes, early stage (< 10 µs) ionization was dominant and evidenced by higher concentrations of Al II. While both sizes exhibit ionization over the same duration, the intensity of emission was greater for nanoparticles indicating greater concentrations of ionized species. Moreover, the dispersion of species was notably more elongated for microparticles while radial dispersion was more pronounced for nanoparticles with elevated drag forces. At later stages (i.e., > 10 µs), oxidation reactions were dominant for both particle sizes, but the same distinctions in flow field were observed and attributed to particle drag. In all stages of interaction, microparticles expand axially with less drag that suppresses their radial expansion. As a result, the dispersion of reactive species was mapped over an up to 80% larger area for nanoparticles relative to microparticles. Results shown here can be applied toward advancing experimental diagnostics and particle shock wave modeling and simulation efforts for energetic materials.
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    Mechanisms describing multi-phase diffusion reactions in energetic mixtures focused on interface sciences
    (2023-05) Vaz, Neil G.
    Solid energetic materials are composed of a solid fuel and solid oxidizer. Solid fuels include metals such as aluminum (Al) which possess a high energy density (31 kJ/g, 84 kg/cm3). Al is used in combination with solid oxidizers such as copper oxide (CuO), molybdenum trioxide (MoO3), ammonium perchlorate (AP), and ferric oxide (Fe2O3). Diffusion forms an important step in determining reaction kinetics during fuel-oxidizer reactions. Diffusion occurs at key locations such as the Al2O3 passivating surface covering the Al particle and at the surface of AP during its decomposition. In this dissertation, methods of enhancing/controlling diffusion-based processes and subsequent energetic heat release are described. Diffusion at the Al2O3 passivation shell was enhanced using an alloy of Al with silicon (Si) i.e., Al-Si. Al-Si particles had a ~0.1 ms earlier achievement of steady flame speed in fast-heating rate flame speed experiments when mixed with MoO3 oxidizer (Al-Si+MoO3) and 5.8% greater early temperature rise in closed Parr bomb experiments on Al/Al-Si. Early heat release for Al-Si is attributed to larger early exotherms seen in Al-Si+MoO3 in thermal equilibrium Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) experiments. Diffusion at the AP surface was enhanced by the development of a new energetic additive with catalytic properties- an amorphous form of a Metal Inorganic Framework (amorphous MIF or a-MIF). This new a-MIF – called amorphous Aluminum Iodate Hexahydrate (a-AIH) is a modified form of a recently developed MIF energetic additive aluminum iodate hexahydrate iodic acid (AIH). a-AIH consists of a rough, porous surface containing Al+ ions acting as catalytic sites, combined with iodine and oxygen that can off-gas to interact energetically with the products of AP decomposition. Open crucible DSC/TGA experiments show that addition of a-AIH to AP in a mixture of 70:30 AP:a-AIH ratio by mass (AP+a-AIH) resulted in an increase in average net heat released during mixture decomposition from +240 J/g net endothermic for pure AP to -1040 J/g net exothermic in AP+a-AIH. Additionally, the mass loss rate during decomposition increases with the addition of a-AIH - i.e., 36°C decrease in peak mass loss rate from 17%/min at 401°C to 18%/min at 365°C. Microscopy and spectroscopy of mixtures and their components were analyzed to identify mechanisms of AP+a-AIH interaction. Enhanced exothermic decomposition in AP+a-AIH was found to be driven by the Al+ ion-rich surface of a-AIH. Al in combination with solid oxidizers in thermite mixtures react to form gaseous aluminum suboxides. In nano-sized Al, gaseous sub oxide Al2O is formed at the surface of the Al particle. This formation of Al2O allows an energetic pathway for oxidation of Al to Al2O to Al2O3 that allows Al to escape the passivation shell otherwise limited by diffusion of condensed Al fuel outwards through the passivating Al2O3 shell. A theoretical analysis of the thermal equilibrium compositions of Al thermite mixtures – Al+CuO, Al+MoO3 and Al+Fe2O3 was conducted using NASA CEA thermal equilibrium analysis software to examine the formation of Al2O. Al2O formation was found to be proportional to the difference in electronegativity between Al and the reduced metal from the metal oxide since it is easier for Al to reduce oxides of more electronegative oxides to form Al2O. Electronegativity of copper (Cu) > molybdenum (Mo) > iron (Fe) > Al corresponding with a peak mass ratio of Al2O to initial Al of 0.76, 0.7 and 0.49 for Al+CuO, Al+MoO3 and Al+Fe2O3 respectively. Al2O energetic pathway was also found suitable to provide heat for other energetic transport processes like reduced oxide (Cu,Fe) metal vapor generation. Addition of alkali metal additives (K, Cs, Na), less electronegative than Al, were found to also increase Al2O formation since such metals create a more reducing environment for Al2O formation. The results of this dissertation, summarized above, provide theoretical and experimental reasoning and proof for the enhancement/control of diffusion-based reactions in energetic mixtures. Such energetic enhancement was achieved using alloyed fuel particles, catalytic/energetic additives for AP and the identification of conditions for gaseous Al suboxide formation to accelerate the diffusion-limited interaction of Al with oxidizer regulated by the passivating Al2O3 shell. Results have application in energetic systems that require enhancement and/or control of energetic heat release such as primers and propellants.
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    Interplay Between Proteins, Lipids, and Membrane Architecture in Dynamic Structure and Allosteric Regulation of Membrane Proteins
    (2023-05) van Aalst, Evan J.
    The plasma membrane of living cells forms the ultimate barrier sequestering cellular function from the surroundings. The membrane itself contains both integral and peripheral membrane proteins and is segregated into ordered and disordered microdomains. In this regime, lipids regulate the function of membrane proteins. Likewise, the presence of membrane proteins incurs an effect on the properties of the bilayer. Thus, there is a critical physiological role for the functional interplay between the membrane and its protein species in homeostatic modulation of lipid bilayer functionality. In this dissertation, I use combined functional assays, molecular dynamics (MD) simulations, and solid-state nuclear magnetic resonance (SSNMR) to unravel the functional interplay between lipid regulation of membrane proteins and formation of membrane architecture. To achieve this goal, I first implemented a version of codon harmonization dubbed Dna codon Usage for Measured Base (DUMB) optimization which was applied to a chimeric G protein-gated Inward Rectifying K+ (GIRK) channel as a proof of concept. Codon harmonization aims to reintroduced more deoptimized codons into the heterologous sequence to match the native codon usage pattern under the hypothesis that more native-like site specific translational rates aid in proper cotranslational folding and therefore higher quality and quantity of protein yield. It was found that DUMB optimization increased yield from ~ 8 to ~14 mg/L. This technique was then applied to the C-C motif Chemokine Receptor 3 (CCR3). CCR3 is a class A G protein-coupled receptor (GPCR) expressed by immune cells. Interaction with peptide agonist chemokines triggers a CCR3-mediated signaling cascade culminating in chemotaxis of the expressing cell along the chemokine gradient. Structurally, little was known of the details of CCR3 function. Using DUMB optimization, yields of up to 4 mg CCR3 per L are observed. Building upon this, a novel fluorescence polarization assay was developed and used to show that cholesterol increases CCR3 affinity for the endogenous ligand C-C motif chemokine 11 (CCL11). Using a GTP hydrolysis assay, it was shown that this directly translated to increased G protein coupling and activation of the Gα inhibitory subunit 3 (Gαi3). Using coarse grain MD (CGMD) and PyLipID analysis, we then predicted cholesterol binding sites in CCR3. SSNMR was then used to investigate bilayer ordering and microdomain formation in membrane extracts of Burkholderia thailandensis. With NMR-level yields, uniformly 15N-13C-labeled CCR3 samples in the presence and absence of cholesterol were generated. It was observed in 2-dimensional Dipolar Assisted Rotational Resonance (2D-DARR) NMR experiments that CCR3 dynamic timescales were slowed when cholesterol was introduced to the membrane environment. Using Comparative, Objective Measurement of Protein Architectures by Scoring Shifts (COMPASS), atomistic MD simulations model structures were graded compared to experimental, unassigned chemical shifts derived from these 2D-DARR experiments. It was found that cholesterol biased regions of the receptor to specific, conserved conformations, including remodeling of the orthosteric pocket and activation pathway contacts. A suite of dynamics experiments were performed on CCR3 to identify the most efficient temperatures at which spectra can be acquired for resonance assignment purposes. Based on results, a set temperature of -40 was identified, which was related to the phase change temperature imparted by the cholesterol-containing bilayer. The findings in this dissertation provide evidence for functional interplay between lipid regulation of membrane proteins and formation of membrane architecture in the context of multiple, highly complex prokaryotic and eukaryotic systems.