UT Electronic Theses and Dissertations (2024)

This dissertation argues that Brazilian hip-hop has worked—and continues to work—as a tool of salvation for most of the Afro-Brazilian youth within the hip-hop community, in São Paulo, Brazil. Therefore, Hip-hop salvação tells the history of the hip-hop generation in Brazil. Using as starting point the sentence hip-hop salvou minha vida, this research investigates the formation of a salvationist discourse in Brazilian hip-hop and informs the impacts of this discourse, for Black youths living in the periferias of São Paulo. I focus on “artivism” as an aspect that is essential to Brazilian hip-hop, where art and activism are fundamental, to promote messages of transformation, racial, political and social empowerment. Throughout this dissertation, I explore how the characteristics of a megalopolis like São Paulo, impacts the characteristics of hip-hop as a social and political movement. In addition, Hip-hop salvação questions the reproduction of sexist, “blaqueerphobic” and patriarchist content, in a movement that promotes itself as emancipatory. My research methods include lyrical analysis of rap music produced by Afro-Brazilian hip-hop artists; analysis of interviews, created during 12 months of collaborative ethnographic field work (between 2015 and 2016); and autoethnography, where I position myself and share my experiences, as a Black woman, whose life was impacted and transformed by hip-hop. This project aims to enhance developing literature on African Diaspora cultural productions, exploring the impacts of hip-hop in the formation of Black identities. In addition, it engages with definitions of salvation, and its impacts in the construction of a salvationist discourse in Brazilian hip-hop. Still, Hip-hop salvação utilizes Black feminisms as a way to create an analysis of the narratives presented throughout this research.

Elaborate animal displays serve crucial functions as animals attempt to deploy displays precisely to maximize reproductive rewards and minimize potential costs. These costs include both the potential wasted resources from a failed display and the possibility that a display might evoke attack from a rival or predator. To achieve this, individuals must integrate both internal and external information before deciding whether to signal and how much energy to invest into a given signal. Here we examine display effort in Alston’s singing mouse, Scotinomys teguina. using leptin, a hormone secreted by adipose tissue that regulates energy allocation. We manipulated individual perception of energy balance through intraperitoneal injection of exogenous leptin and social context through playback of conspecific song. Leptin-injected mice responded with song to playback more frequently and quickly than saline-injected controls. Although leptin promoted increased song effort, we found that leptin also reduced song duration. Playback of conspecific songs also increased song effort. We next focused on social context by recording focal males when alone, in the presence of a familiar female mouse, with an unfamiliar female mouse, and with an unfamiliar male mouse. Singing mice produce two distinctive types of songs: the long, well-studied advertisem*nt song and a short “strophe” song that is disproportionately produced in the presence of females. Advertisem*nt songs produced in the presence of females are quieter but longer than those produced in other treatments. These advertisem*nt songs also contain enough information to identify individuals. Upon further analysis of recordings, we find that singing mice also produce short vocalizations that are similar to the ultrasonic vocalizations common in rodents. These are almost never found when alone and are vastly more common in female-directed treatments than in other treatments. A cluster analysis shows that they fall into four distinct types: peeps, sweeps, and warbles, plus the short “strophe” songs discussed previously. All are more commonly produced to female audiences than to other males, and all contain identity information similarly to advertisem*nt songs.

After a relatively slow start, the field of RNA epigenetics has exploded in recent years. As with DNA, RNA modifications are controlled by proteins capable of post-transcriptionally writing, reading, or erasing position-specific modifications to affect downstream processes. In this dissertation, we focus on the molecular mechanisms surrounding RNA modification writers and how they contribute to human cancer. Our studies center upon BCDIN3D, a Bin3 domain-containing RNA methyltransferase. A 2012 study (Xhemalçe et al.) established BCDIN3D catalytic activity on the 5’ mono-phosphate of specific precursor miRNAs while intriguingly showing that downregulation of BCDIN3D in human triple negative breast cancer cell line MDA-MB-231 led to decreased transformation and invasion in vitro. In order to understand the mechanisms underlying these effects on human cancer cells, we performed in depth analyses of the RNA and protein interactome of BCDIN3D. Sequencing of BCDIN3D-associated RNAs through TGIRT-seq revealed a dominant tRNA [superscript His] interaction and a new role for BCDIN3D in regulation of miR-4454, which is possibly derived from noncanonical processing of the tRNA [superscript His] 3’ end. Proteomic analysis of BCDIN3D interactors unexpectedly revealed the presence of two 5-methylcytosine (m⁵C) RNA methyltransferases, NSUN2 and NSUN5. While the interaction with NSUN2 is likely related to tRNA [superscript His] m⁵C modification, characterization of NSUN5 unearthed a number of intriguing new putative targets and pathways influenced by m⁵C activity, as well as promise for future therapeutic development in human cancers.

The objective of this Phenomenological inquiry sensitized by a lens of Foucauldian Power and Resistance was to explore the experiences of heterosexual cisgender parents and guardians of lesbian, gay, bisexual, transgender and questioning/queer (LGBTQ+) youth as they access healthcare for or alongside their youth ages ten through twenty. The need for this investigation was based on a comprehensive review of LGBTQ+ health science literature. The scope of health issues encompassed adults and youth, the elderly and aging, racial and gender disparities, educational attainment and employment, homelessness, suicide, substance use, sex work and safety sex, sexual assault and domestic violence, STI/HIV/AIDS prevention and treatment, social stigma and violence, social isolation, hom*ophobia in healthcare, institutionalized heteronormativity in social policy as well as the impact of early negative disruptions and positive influences. This unique variant of healthcare research addressing upstream factors provides additional data for health providers and systems to decrease a multitude of disparities affecting LGBTQ+ youth. A Snowball sampling procedure in a large Southern United States metropolitan area allowed for a sample of eleven participants to be obtained and interviewed within approximately one month. Exclusion criteria was set to parent or guardian sexual orientation and youth age due to difficulties in reaching this population. Interviews were guided by a semi-structured interview schedule. Demographic information was used to describe the target population while 75-90 minutes of audio tapped interview data and field notes were transcribed, coded and analyzed using meaning unit aggregation, concept aggregation and thematic generation. Participants received $60.00 in appreciation of their time and sharing their stories. The findings of this study were organized in seven major thematic and contained 31 sub-themes. This study concludes that LGBTQ+ youth are at risk of discrimination from healthcare providers, however, specialized clinics that are gender affirming provide both parents and youth the opportunity to receive high quality care. This study also concludes that Phenomenology sensitized by Foucauldian Power and Resistance are synergistic in their ability to meaningfully explore the barriers parents experience and the ways in which they circumvent those barriers.

We compare two different design intervention strategies for building resilience to climate change in Austin, Texas. The impact on the total energy use and cooling load are analyzed, with both projected to increase from 2020 to 2100[1]. The comparison uses a building designed to 2015 IECC standards and is modeled in the eQuest 3.65 energy modeling tool. The design intervention strategies compared are floor-to-ceiling height and overhang depth to determine their impact on reducing the total energy use and cooling load of a mid-rise office building. The simulations in eQuest are modeled for three different decades; 2020, 2050, and 2100. These are compared through the use of projected weather files generated by the IPCC. Compared to a baseline building with nine foot ceiling levels and zero foot overhangs, two additional building models are simulated for each year using two design intervention strategies. 1: Adding a three foot overhang to the baseline building. 2: Reducing the baseline line ceiling height to eight feet with a zero foot overhang. The results of the simulation show that a) an overall energy use reduction of up to 5219 kWh (1.182%) by 2050 and 7058 kWh (1.517%) by 2100 occurs using design intervention 1:, b) an overall energy use reduction of up 5246 kWh (1.188%) by 2050 and 6937 kWh (1.276%) by 2100 occurs using design intervention 2:, and c) the cooling load distribution does not follow this same pattern with design intervention strategy 2: reducing the cooling capacity the most in both 2050 and 2100.

The three chapters of this dissertation explore the effects of two of the largest policy levers in the United States, Medicare and Medicaid, on health and hospitals. My first chapter examines the effects of Medicare on short-run mortality. Despite being at the forefront of policy debates, credibly estimating whether health insurance reduces mortality remains empirically elusive. The key challenge is creating research designs that have the statistical power to reliably detect the effects of health insurance on mortality. This chapter presents new, population-level estimates of the impact of Medicare on short-run mortality. I use restricted-access Census data to link complete, administrative death records to individual survey responses for nearly 30% of the US population. To understand the effects of Medicare on mortality, I use a regression discontinuity design, comparing the mortality of individuals just above and below the age-65 eligibility threshold. I also consider whether the impact of Medicare on mortality differs by demographics, previous health insurance status, and income-level. I find no statistically significant effects of Medicare on mortality for the full population, previously uninsured, or low-income individuals. The second chapter of my dissertation looks at the effects of the Affordable Care Act Medicaid Expansion on mortality. Given that Medicaid and Medicare are two of the largest policy levers for improving health in the United States, it is important to compare the mortality effects of Medicare to those of Medicaid. This chapter examines whether Medicaid eligibility reduces mortality for near-elderly individuals. I begin by using CDC data and a differences-in-differences design to analyze whether the ACA Medicaid Expansion reduced the mortality rate for individuals aged 55-64. I note several potentially important limitations in using CDC data for studying the effects of Medicaid on mortality. I discuss the merits of circumventing these limitations by using the restricted Census infrastructure to link survey data to administrative death records. I conclude with a cross-study comparison of the effects of Medicare and Medicaid on mortality, and discuss the policy relevance of my findings. The third chapter of my dissertation studies how hospitals respond to the Affordable Care Act Medicaid Expansions. While the first two chapters of the dissertation focus on the benefits of public health insurance for insurance recipients, public health insurance can also significantly benefit health care providers. Hospitals frequently provide health care to uninsured patients without receiving compensation. ACA Medicaid expansions reduced hospitals’ uncompensated care burdens by providing the uninsured with a means of payment in the form of insurance. Anecdotal evidence from hospital administrators suggests hospitals in expansion states respond to their improved financial positions by increasing capacity, purchasing equipment, and hiring more workers. I investigate such claims using hospital financial report data from CMS. Using a differences-in-differences regression framework, I find no evidence that hospitals in expansion states increased bed capacity, capital expenditures, or FTEs relative to hospitals in non-expansion states.

In the booming era of Internet-of-Things (IoT), the trend of pushing inference from cloud to edge due to concerns of latency, bandwidth, and privacy has created a demand for energy-efficient edge computing devices. The edge computing devices have been the critical building blocks in modern electronic systems, supporting various applications such as neural network inference, mobile healthcare monitoring, and human-machine interface. To improve the energy efficiency of edge devices, the author worked in three directions: 1) developing a ternary neural network accelerator achieving higher energy-efficiency than state-of-the-art binary neural network; 2) developing a 4-bit neural network accelerator with one-shot ADC conversion for the entire MAC array; 3) a long-term, real-time muscle fatigue detection device with ultrathin, ultrasoft, and long-term stable dry epidermal electrodes. In the first part, we propose a mixed-signal ternary CNN-based processor featuring higher energy efficiency than BNN. It confers several key improvements: 1) the proposed ternary network provides 1.5-b resolution (0/+1/-1), leading to 3.9x OPs/inference reduction than BNN for the same MNIST accuracy; 2) a 1.5b multiply-and-accumulate (MAC) is implemented by VCM-based capacitor switching scheme, which inherently benefits from the reduced signal swing on the capacitive DAC (CDAC); 3) the VCM-based MAC introduces sparsity during training, resulting in lower switching rate. With a complete neural network on chip, the proposed design realizes 97.1% MNIST accuracy with only 0.18μJ per classification, presenting the highest power efficiency for comparable MNIST accuracy. The second part of this dissertation focuses on a 4-bit MAC macro. This work proposes a mixed-signal MAC macro that requires only 1 ADC operation for the entire 512 4b×4b MAC. This is achieved by mapping 9 partial products onto 5 wires based on their relative weights, dynamic buffering 5 wire voltages, and sampling them on properly sized SAR ADC capacitors. As a result, all MAC operations are finished in the charge domain by the end of the ADC sampling, allowing only 1 A/D conversion per multi-bit MAC. To further increase power efficiency, window-based comparison skipping and ReLU are embedded inside the SAR ADC, so that unnecessary comparison cycles are skipped for small or negative MAC outputs. Overall, despite using a 65nm process, the prototype chip achieves an energy efficiency of 164 TOPS/W for a 4-b MAC. Finally, this dissertation also presents a long-term, real-time muscle fatigue monitoring system consisting of 1) a hair-thin, skin-soft and mechanically robust e-tattoo electrode which is less susceptible to motion artifacts and capable of multi-day monitoring, 2) a battery-powered edge computing flexible printed circuit (FPC) which extracts instantaneous median frequency (IMDF) of surface electromyography (sEMG) bursts and wirelessly streams them to a mobile application. The system consumes an average of 33 mA current, supporting 25 hours of continuous operation, and could be extended into multiple days if only activated intermittently.

Membrane-based separations are promising candidates for achieving water security through treatment and reuse of nontraditional waters (e.g., industrial/municipal wastewater, produced water). However, nontraditional waters can be highly impaired and contain a plethora of contaminants, which poses challenges for conventional membrane processes to treat such waters. Two major challenges faced by conventional membranes that limit their expansion to new reuse opportunities are poor removal of small, neutral solutes and membrane fouling. This dissertation investigates the potential for conventional and novel membrane processes to remove boric acid – a small, neutral solute that prevents water reuse in agriculture since boron is toxic to some plants – and prevent membrane fouling during water treatment. Results of this dissertation show poor boron removal and membrane fouling by (in)organic constituents can be overcome via integration of conventional and novel membrane materials/processes in fit-for-purpose treatment trains. Potential solutions include electrodialysis pretreatment to remove ions that contribute to membrane fouling, thereby enabling pH adjustments to increase boron rejection, as well as ligand-functionalized membranes to remove boron through a capture-and-release mechanism. Incorporation of these and other novel technologies in fit-for-purpose treatment trains will expand reuse capabilities for highly contaminated waters. In addition to material/process advancements, this dissertation presents fundamental research on boron selectivity and membrane fouling that can be used to guide the design of future membrane processes. Boron transport in nonporous membranes is shown to depend on bulk properties of solutes (e.g., size, hydrophobicity) and membranes (e.g., cross-link density), as well specific solute-membrane interactions such as hydrogen bonding. Membrane fouling by organic foulants such as natural organic matter (NOM) occurs through calcium-induced aggregation of NOM in solution followed by aggregate deposition and formation of disordered membrane fouling layers. These results encourage the design of novel membranes to minimize foulant affinity without compromising small, neutral solute rejection; integration of such membranes in fit-for-purpose treatment trains (with proper pretreatment) will enable reuse of unexplored water sources to address water and energy challenges worldwide.

Here I show the work accomplished in my graduate career on metal oxide nanocrystals and their assembly into unique gels. Nanocrystals were synthesized using a well-established method that was adapted to improve subsequent functionalization. Collaborations between the Anslyn group led to ligands that were designed for tunable orthogonal covalent linkages between particles. Establishing a well solid foundation for controllable assembly through this collaboration was the goal, along with a better understanding of the system through collaboration with the Truskett lab and the work they do on simulations and theory. Applying what was learned and theorized into studying differences in similar systems for changes to the optical response also became a goal of the work presented. All put together an understanding of the building blocks of assembly, the assembly method, and finally the properties of the assembly are discussed within.

The COVID-19 pandemic has presented a need for collective action to fight an ecological threat. The perceived and actual threat of the virus were both largely dependent upon one’s geographical location, socioeconomic status, preexisting health conditions, and available information. People more frequently act according to their own beliefs or intuitions than factual knowledge of an objective threat, however. Variation in perceived threat levels is also known to influence expectations around normativity and compliance. This can be measured by the Cultural Tightness Looseness (CTL) scale. Therefore, I examined people’s perceived threat of getting infected with COVID-19, their CTL scores, and their compliance with COVID-19-related health norms. According to previous work, when perceived threat levels increase, cultures start to “tighten,” and social norms are more pronounced and strictly enforced. Therefore, I conducted a cross-sectional survey in 11 culturally and geographically diverse countries with different COVID-19 infection and vaccination rates to explore the association between individuals’ risk perception of COVID-19 and their CTL scores. To do this, I collected self-report data on different levels of threat perception (four levels: threat to self/ family/ community/ country) and CTL scores. Next, I used threat perception and CTL scores to predict self-reported norm compliance (vaccination status, vaccine willingness, and frequency of mask-wearing). I examined these associations in a mixed-effects multilevel model. I found that more distant levels of threat perception (especially to one’s community and country) were statistically significant predictors of compliance. However, when I examined the effects of threat and CTL in a mediation analysis, I found that CTL had no mediating role in the relationship between threat perception and compliance, suggesting that individuals’ threat perception and CTL scores independently influenced compliance during the COVID-19 pandemic.

The present study examines a) the relationships of specific types of personal experience with COVID-19 and risk perception and b) the role of political orientation and age in mediating COVID-19 experiences and risk perception across ages in 11 countries in July 2021 (Brazil, China, Germany, India, Israel, Japan, Mexico, Russia, South Africa, the United Kingdom, and the United States). These countries were chosen for their geographic and cultural diversity and were representative of different stages of the COVID-19 pandemic and vaccine accessibility. Across all countries, knowing a family member was the most common type of experience, followed by knowing a family member with severe effects from COVID-19, knowing someone who died from COVID-19, and testing positive for COVID-19, respectively. The strongest predictors of risk perception included knowing a family member with COVID-19 or a family member with severe effects from COVID-19. My data also show patterns of the misalignment between scientific risk and perceived risk between older and younger age groups, where participants 18-29 reported low levels of perceived risk for susceptibility and severity of COVID-19, while individuals 65 or older reported low levels of susceptibility and high levels of perceived severity. I found that political orientation mediated the relationship between personal experiences and perceived risk after controlling for age and gender. In each country, liberal participants reported higher risk perceptions than conservative participants. Understanding these age and political orientation differences can improve the effectiveness of apolitical public health initiatives and shed light on the need to reevaluate risk perception assessments.

Soft pressure sensors are critical components of e-skins, which are playing an increasingly significant role in two burgeoning fields: soft robotics and bio-electronics. Capacitive pressure sensors are popular given their mechanical flexibility, high sensitivity, and signal stability. After two decades of rapid development, e-skins based on soft capacitive pressure sensors are able to achieve human-skin-like softness and sensitivity. However, there remain two major roadblocks in the way of the practical application of soft capacitive pressure sensors: 1) the decay of sensitivity with increased pressure and 2) the coupled response between in-plane stretch and out-of-plane pressure. This dissertation aims to tackle the two critical challenges. To increase the sensitivity of a capacitive pressure sensor, past research has mostly focused on developing dielectric layers with surface/porous structures or higher dielectric constants. However, such strategies have only been effective in improving sensitivities at low pressure ranges (e.g. up to 3 kPa). To overcome this well-known obstacle, I devised a flexible hybrid response pressure sensor (HRPS) composed of an electrically conductive porous nanocomposite (PNC) laminated with an ultrathin dielectric layer. Using a nickel foam template, the PNC was fabricated with carbon nanotubes (CNT) doped Ecoflex to be 86% porous and electrically conductive. The PNC exhibits hybrid piezoresistive and piezocapacitive responses, resulting in significantly enhanced sensitivities (i.e., more than 400%) over wide pressure ranges, from 3.13 kPa⁻¹ within 0-1 kPa to 0.43 kPa⁻¹ within 30-50 kPa. The effect of the hybrid responses was differentiated from the effect of porosity or high dielectric constants by comparing the HRPS with its purely piezocapacitive counterparts. Fundamental understanding of the HRPS and the prediction of optimal CNT doping were achieved through simplified analytical models. Second, coupled pressure and stretching responses disable capacitive sensors to differentiate out-of-plane and in-plane inputs. Due to this critical limitation, intrinsically stretchable and accurate capacitive pressure sensors have not been successfully demonstrated, while other types of soft sensors have already achieved stretchability beyond flexibility. To discriminate the compression and stretching responses, I proposed a stretchable hybrid response pressure sensor (SHRPS). SHRPS is a stretchable version of HRPS, whose sensitive pressure response trivializes the stretching response and enables the SHRPS to accurately read applied pressure even under stretching. Analytical models for conventional capacitive pressure sensors, HRPS and SHRPS have been developed and provide fundamental electromechanical understanding for the difference among the three. As a demonstration, a 3 x 3 SHPRS array has been glued to an inflatable manipulator which is capable of diverse tasks such as pulse palpation and object grabbing given the tunable inflation. A perspective for the future directions of HRPS is provided at the end of the dissertation.

The glycocalyx, an interior lining of blood vessels, forms a barrier against atherosclerotic risk factors. It is degraded during plaque development, allowing cholesterol deposition and inflammation in the intima. Rhamnan sulfate (RS), a polysaccharide from green seaweed, resembles heparan sulfate, a component of the glycocalyx which can replace and rejuvenate the glycocalyx to enhance barrier function and prevent plaque formation. In vitro, we tested the interaction of RS with vascular cells and its effects on their proliferation, migration and inhibition of the NF-κb pathway. We also tested the effects of RS on glycocalyx stiffness and thickness post-inflammation. In vivo, we conducted a study in female and male ApoE [superscript -/-] mice on a high fat diet where RS treatment was provided orally. We found that RS decreased growth factor induced proliferation and migration of endothelial and vascular smooth muscle cells. It also decreased the activation of NF-κb in response to TNF-α treatment while binding to NF-κb subunits. Mechanical properties of the glycocalyx could be restored with RS under certain inflammatory conditions. ApoE [superscript -/-] mice, oral consumption of RS decreased cholesterol levels in the plasma in female mice and plaque area in both female and male mice. In livers of these mice, RS treatment showed significant differences in genes related to metabolism, circadian rhythm and lipid regulation between high fat diet and RS groups and male and female mice.

Transition metal dichalcogenides (TMDs) are layered semiconductor materials that can be exfoliated into atomically thin monolayers and deliberately stacked into vertical heterostructures to engineer artificial 2D materials with unique optical and electronic properties. When two such monolayers are stacked together with a small twist angle, the resulting heterostructure contains a moiré potential that can localize or impede the transport of optically generated excitons. In a similar way, thin layers of hexagonal boron nitride (hBN) can be exfoliated, twisted, stacked, and employed as a substrate to provide an externally sourced moiré potential to a TMD monolayer and thereby modify its exciton diffusion. In this dissertation, I present novel experimental results to demonstrate the above phenomena and explore the spatiotemporal dynamics of both excitons and electron-hole plasma that can form through optical excitation in TMD semiconductor structures with a moiré potential. Specifically, we stacked two TMD monolayers, MoSe₂ and WSe₂, into a vertical heterostructure with a small relative twist angle (near 60° or H-stacking) and hBN encapsulation. By performing spatiotemporally resolved pump probe measurements with different pump powers and repetition rates, we probed diffusion in this heterostructure across three orders of magnitude of excitation densities. While the moiré potential impedes the diffusion of interlayer excitons at low excitation densities, high excitation densities above the Mott density allow for the formation of an electron-hole plasma that undergoes a sub-picosecond rapid expansion driven primarily by coulomb repulsion and Fermi pressure. In a separate sample, we explore a WSe₂ monolayer that is placed on top of an hBN substrate with two distinct regions. One region of this substrate contains only a single thin layer of hBN, while the other substrate region has an additional thin hBN layer that is stacked above the first layer with a small relative twist angle. The WSe₂ monolayer that resides above the hBN layers only feels a moiré potential on top of the twisted substrate. Spatiotemporally resolved pump probe measurements show that the WSe₂ monolayer has reduced exciton diffusion on top of the twisted hBN substrate.

Due to improved therapeutic regimens for cancer, disease grade, stage, and subtype, have become pertinent stratifications for prescribing an optimized treatment plan for every patient. Histopathologists are now being asked to perform increasingly complex disease distinctions from small biopsy samples that may or may not provide the necessary information to make such distinctions. Since inception, mass spectrometry (MS) have been proven to be a powerful analytical tool for disease diagnosis and several MS techniques have been successfully integrated into routine clinical workflows. Over the past two decades, ambient ionization MS, particularly desorption electrospray ionization mass spectrometry imaging (DESI-MSI), has been studied for disease differentiation in a similar manner. Intrinsic advantages of DESI-MSI, such as minimal sample preparation, nondestructive solvent system, and spatial separation of relevant tissue, supports the successful integration of this technology into a pathological workflow. Despite these advantages, research is ongoing to determine the efficacy of DESI-MSI as a tool for intricate disease stratification and biopsy analysis.This dissertation presents the applications of DESI-MSI towards staging advanced disease, classifying preneoplastic lesions, and subtyping cancerous tissue from tissue sections and minimally invasive biopsy material. Chapter 2 discusses the application of DESI-MSI and statistical analyses to understand metabolic dysregulation in primary and metastatic melanoma as well as discusses the performance of statistical classifiers on metastatic melanoma in lymph node tissue. Chapter 3 presents the application of DESI-MSI and statistical classifiers towards differentiation of low grade and high grade preneoplastic pancreatic cysts. Finally, Chapter 4 describes the application of this technique towards the stratification of lung cancer subtypes from tissue sections and biopsy material. In entirety, this work aims to demonstrate the capabilities of the DESI-MSI workflow towards increasingly complex biospecimens and diagnostic challenges commonly confronted in routine clinical environments.

“Extended Play/Extended Performance” examines Black women’s cultural production in a specific socio-cultural moment where Black women continue to create in spite of and in response to, a time of societal upheaval and turmoil for Black Women across the diaspora. At this time of increased visibility for Black aesthetics, my project investigates Black women’s cultural production in the space of music. While the contributions and work of Black Women in music have been discussed by scholars like Joan Morgan and Daphne Brooks, and a slew of work has been written on Black women in music like Beyoncé and Janelle Monaé, “Extended Play/Extended Performance” pushes the conversation forward, both by analyzing artists in the Hip Hop space that embody their own unique versions of crude and explicit performance, but also by exploring Black women in the DJ and music producing space, two areas that are still heavily under-researched within music, Black feminism, and pop culture scholarship. Utilizing Black feminist thought, textual analysis, and auto-ethnography, to analyze and uplift Hip Hop artists Meg Thee Stallion and Rico Nasty, and DJ/ Music Producers Honey Dijon, and BAMBII, “Extended Play/Extended Performance” makes clear the value and liberatory possibilities that lie in the work of Black women in the Hip Hop, DJ, and music producing spaces. Crude work, crude cultural production by Black women in musical performance offers Black women a space for different modes of being and the ability to engage with various aspects of their own identities. This is done in a myriad of ways, such as crude cultural production’s ability to create physical and sonic spaces for Black women through the artists' music. Crude cultural production is necessary for Black women because of its inherent ability to push up against restrictive notions of respectability often used to other and harm Black women. Moreover, crude cultural production by Black women bears access to a holistic liberation for Black women, even as they contend with the realities of the ways their work and various forms of labor operate in a capitalist space.

Petrographic and petrophysical data from 57 sandstone samples collected from the available parts of a 2500 ft section of core (-5094 ft to -7474 ft) recovered from the Seaboard Oil Kolodziejcyk #1 well in southeastern Karnes County were used to determine the diagenetic changes within the rocks and their effect on porosity and, indirectly, permeability. The core penetrated deposits of shoreface (with probable tidal channel and/or small (tidal?) delta), tidal flat and bay-lagoon environments. Framework grain mineralogy is similar for samples regardless of environment of deposition. The sandstones are chiefly fine to very fine and well sorted with an average composition of Q₅₉ F₁₆ R₂₅; matrix values range from 0 to 46 percent and cement values range from 8 to 34 percent. Permeability values range from nil to over 650 millidarcies. Porosity values, also determined by gas injection, range from 6 to 36 percent and thin section determined porosity values range from 0 to 20 percent. Petrophysically-determined porosity has a positive correlation with both "petrophysical" and "petrographic" porosity. Initial porosity of sand was reduced by the following sequence of partly overlapping events: bioturbation penecontemporaneous with deposition; compactional rotation of framework grains; compactional deformation of ductile grains; and precipitation of authigenic quartz, kaolinite, calcite, ferroan calcite and dolomite cement. A few samples lost most porosity due to bioturbation penecontemporaneous with deposition but the majority lost about 12 percent due to compactional effects followed by up to 30 percent loss by cementation. Up to 21 percent porosity resulted from the dissolution of calcite from sandstone by natural acid formation water at about the maximum depth of burial. This secondary porosity formed by the dissolution of both calcite cement and calcite-replaced framework grains (chiefly plagioclase) and is most pronounced in shoreface and tidal channel sandstones. Secondary porosity is identified by patchy distribution of calcite cement, locally oversized pores (where framework grains were replaced and the replacement calcite and adjacent calcite cement were removed), ragged edges on some quartz overgrowths in samples without calcite that are the result of corrosion of quartz grain margins by calcite, and skeletonized plagioclase grains in samples without calcite cement. Because essentially all effective porosity in these Wilcox sandstones at present is secondary porosity, porosity is not a function of depth in the well studied. If secondary porosity like that in Wilcox sandstones forms elsewhere in the Gulf Coast and other basins, good reservoir sandstones will exist at depths greater than expected under normal conditions in the subsurface

This document presents an approach to modelling the sintering of nanoparticles for applications in solid-state diffusion micro–Additive Manufacturing processes like the novel Microscale Selective Laser Sintering process. The simulations presented here use the Discrete Element Method and Phase Field Modelling approach to model the sintering of nanoparticles. There are currently no simulations of solid-state sintering for nanoparticles in a powder bed. These simulations are important to understand the kinetics on the particle scale, the phenomenon driving sintering and how the nanoparticles fuse together with input energy. Understanding this allows for a better control of the actual fabrication process. In this dissertation, the steps taken to build this simulation package are detailed. Additional simulation tools are created for analysis of the resulting sintered simulation beds. Scripts for visualizing the particles are used to depict the sintering process and are qualitatively compared to Scanning Electron Microscopy images of actual nanoparticles after solid-state sintering. These qualitative results show good agreement between the simulation results and the experimental results. To provide quantitative metrics to test the simulation, packages are developed to measure the amount of densification in the sintered powder beds as well as the electrical resistance as the densification of the bed increases. These metrics are used for calibration as well as validation of the sintering simulation. Several experiments are performed for the purposes of calibrating the simulations to physical parameters, as well as validating the simulation results. The details of these experiments are also presented in this document as well as the resulting findings. Prior to this, there is yet to be any publicly available data from experiments of this kind, measuring the densification of copper nanoparticles as functions of temperature and time, as well as the electrical resistivity as a function of densification. The simulation results are compared to experimental results and show that the simulations can be accurately used to make predictions for the electrical resistance properties expected during solid-state sintering of the copper nanoparticles used in this study.