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SCALABLE NUMERICAL SIMULATIONS OF NONLINEAR AND ATTENUATING ACOUSTIC WAVES
No full textThesis (Ph.D.)--Michigan State University. Computer Science - Doctor of Philosophy, 2025Medical ultrasound is routinely applied to a variety of diagnostic and therapeutic procedures. To assist in the development, design, and optimization of medical ultrasound transducers and systems, computer simulations province important guidance in an effort to uncover essential interactions between ultrasound and soft tissue that determine system performance. Most ultrasound simulations model linear wave propagation, but better models of shock waves and power law attenuation are still needed. Furthermore, existing numerical models of acoustic wave propagation either rely on simplifying assumptions of underlying physics and/or cannot be efficiently parallelized for distributed memory computer hardware.To address these deficiencies, two new numerical implementations are presented that broaden the possible phenomena that can be efficiently modeled with parallel architectures. First, a new method of injecting power-law attenuation into spatial impulse response calculations is introduced. This method is embarrassingly parallel and thus well suited for 3D simulations. Second, a scheme for utilizing the discontinuous Galerkin method for 3D modeling of nonlinear, attenuating wave propagation in both homogeneous and heterogeneous media is derived and implemented.In addition to full descriptions of these methods, simulation results obtained from the data collected with corresponding codes are presented. 3D simulations and comparisons to existing theory are shown for both schemes. The discontinuous Galerkin (DG) method requires frequent communication between processors but only between nearest-neighbors, which enables excellent parallel performance of DG simulations on large computer clusters. This is demonstrated on up to 1024 cores through scaling studies. For the lossy spatial impulse response, simulation studies enable the assessment of convergence as the attenuation parameter is varied. These computer simulations enable evaluations of fundamental properties that are either presently unavailable or difficult to describe with existing ultrasound software models.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Intersectional Approaches to Understanding Working-Class Candidates and Politicians
No full textThesis (Ph.D.)--Michigan State University. Political Science - Doctor of Philosophy, 2025Working-class people make up the majority of the U.S. labor force but remain starkly underrepresented in political office (Carnes, 2012, 2013). This underrepresentation also affects women of color and those in feminized care and service occupations, who often encounter compounded barriers to candidacy and political inclusion. While research on political elites increasingly accounts for race and gender, class remains undertheorized\u2014especially as it intersects with other marginalized identities. This dissertation argues for a more expansive, intersectional understanding of candidate emergence and representation, positioning occupational class as a central dimension of political identity and inequality. I ask: (1) How do occupational class backgrounds\u2014particularly Working-Class Plus\u2014and their intersections with race/ethnicity and gender shape electoral representation and success in state-level elections? (2) What barriers do Working-Class Plus candidates face\u2014and can labor-centered candidate training programs mitigate them (3) How do voters evaluate Working-Class Plus candidates, and what do their attitudes reveal about class-based political representation? To answer these questions, I use a mixed-methods design, including hand-coded candidate-level data from the 2020 and 2022 state legislative elections, semi-structured interviews with Working-Class Plus officeholders and candidates, and a nationally representative survey experiment. The findings show that Working-Class Plus candidates are severely underrepresented in the electoral pool and face consistent electoral disadvantages. Interviews reveal structural, financial, and identity-based challenges that Working-Class Plus candidates face while running and serving in office\u2014challenges that may be mitigated by labor-focused training programs. Survey data suggest that voters hold highly favorable attitudes toward Working-Class Plus candidates, despite doubts about their electability. This study contributes to research on candidate emergence and descriptive representation by theorizing working-class identity as intersectional and documenting the structural, institutional, and perceptual barriers that shape who runs\u2014and who wins\u2014political office in the United States.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Phenotypic assessment of turkey satellite cells and muscle tissue under thermal challenge using metabolomics
No full textThesis (Ph.D.)--Michigan State University. Food Science - Doctor of Philosophy, 2025Climate-induced thermal stress during early post-hatch development poses a significant threat to commercial turkey production, particularly in modern genetic lines selected for rapid growth and high breast muscle yield. The first week post-hatch is a critical window for muscle development, as satellite cells are highly active during this period and contribute to long-term muscle structure and performance. Satellite cells are responsible for postnatal muscle fiber growth and regeneration, and their function is highly sensitive to environmental conditions. Disruption during this phase may alter their proliferation and differentiation capacity, leading to compromised muscle development and reduced meat quality. This study employed an untargeted metabolomics approach to comprehensively characterize the effects of heat and cold stress on satellite cell metabolism during both proliferation and differentiation from two turkey lines, as well as in pectoralis major tissue of three-day-old poults.In proliferating satellite cells, heat stress induced an anabolic metabolic profile characterized by elevated amino acids, purine intermediates, and lipid signaling molecules. This reflected enhanced protein synthesis, nucleotide biosynthesis, and growth signaling, along with oxidative stress markers that indicated increased energy turnover and stress adaptation. In contrast, cold stress led to broad metabolic suppression in proliferating satellite cells, with notable decreases in nucleotides, membrane lipids, energy cofactors, and amino acids. This profile suggested a shift toward a quiescent or stress-conserved state with impaired biosynthesis and energy production, potentially limiting the expansion of the satellite cell pool during this critical period. Differentiating satellite cells exhibited a distinct metabolic phenotype in response to heat stress, marked by elevated mitochondrial activity, lipid remodeling, and redox regulation. Notably, there was significant upregulation of nucleotide biosynthesis and salvage pathways, calcium mobilizing metabolites, amino acids involved in protein synthesis and redox buffering, and fatty acid oxidation intermediates. These findings suggest that heat stress promotes terminal differentiation by supporting transcription, membrane expansion, and mitochondrial oxidative phosphorylation, albeit with the risk of increased oxidative stress. Cold stress, on the other hand, induced widespread metabolic downregulation in differentiating cells. Suppression of nucleotide metabolism, energy cofactors, calcium signaling molecules, and membrane lipids indicated a global reduction in transcriptional activity, mitochondrial function, and membrane remodeling. These alterations likely impair myotube formation and compromise the structural maturation of muscle fibers. In 3 d old turkey poults\u2019 pectoralis major tissue, heat and cold stress produced more selective shifts in metabolism. Heat stress elicited changes in lipid species associated with membrane remodeling and inflammation, as well as elevated amino acids indicative of a compensatory or adaptive growth response. Cold stress led to more subtle reductions in energy metabolites and biosynthetic intermediates, consistent with growth suppression during early life. Together, these findings demonstrate that heat and cold stress drive markedly different metabolic programs in satellite cells and muscle tissue depending on developmental stage and genetic background. Heat stress generally enhances metabolic activity, supporting growth and differentiation but with oxidative risks, while cold stress suppresses key biosynthetic and energetic pathways, potentially limiting muscle development. These insights provide a mechanistic understanding of how early thermal stress influence muscle growth and may inform strategies to mitigate factors that affects meat quality in commercial turkey production.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Immunocarginogenesis : Extracellular Vesicles from Macrophages Mediate Inflammation and Tumorigenesis in Colitis-Associated Cancer
Get PDFThesis (Ph.D.)--Michigan State University. Biomedical Engineering - Doctor of Philosophy, 2025Many conditions of chronic inflammation, such as ulcerative colitis, predispose an individual to developing cancer. The predisposition of chronically inflamed tissue to neoplasia and malignancy is referred to as immunocarcinogenesis. Colitis is characterized by relapsing episodes of inflammation and ulceration in the colonic mucosa. Macrophages play an important role in regulating the immune response in colitis, and secrete proinflammatory factors that may promote colitis-associated cancer. Extracellular vesicles (EVs) have been shown to mediate colitis and colon cancer progression, and there is accumulating evidence suggesting that the activation states of macrophages influence EV secretion and signaling effects in inflammation and cancer. Macrophages in the ulcerated colonic submucosa are exposed to increased levels of bacterial endotoxins, so we sought to model EVs from colitis in culture using EVs from lipopolysaccharide (LPS)-activated macrophages. To investigate the impact of EVs from macrophages on mediating colitis-associated cancer, we characterized EVs from LPS-activated macrophages, treated colon cells and tumors with isolated macrophage EVs, and analyzed the inflammatory and pro-tumorigenic effects in vitro and in vivo. Our results provide evidence that EVs released from LPS-activated macrophages increase inflammation in the colonic epithelium, can promote cell growth, lead to anchorage-independent growth, induce pro-tumorigenic protein expression in transformed cells, and significantly alter the local immune environment. These findings suggest that macrophage-derived EVs may serve as key mediators between colonic inflammation and cancer development, and identify specific EV proteins as potential therapeutic targets to interrupt the progression of colitis-associated malignancy.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
Machine Learning-based Stochastic Reduced Modeling of GLE and State-dependent-GLE
Get PDFThesis (Ph.D.)--Michigan State University. Computational Mathematics, Science and Engineering - Doctor of Philosophy, 2025Predictive modeling of high-dimensional dynamical systems remains a central challenge in numerous scientific fields, including biology, materials science, and fluid mechanics. When clear scale separation is lacking, a reduced model must accurately capture the pronounced memory effects arising from unresolved variables, making non-Markovian modeling essential. In this thesis, we develop and analyze data-driven methods for constructing generalized Langevin equations (GLEs) and extended stochastic differential equations that faithfully encode non-Markovian behaviors.Building on the Mori\u2013Zwanzig formalism, we first propose an approach to learn a set of non-Markovian features\u2014auxiliary variables that incorporate the history of the resolved coordinates\u2014so that the effective dynamics inherits long-time correlations. By matching evolution of correlation functions in the extended variable space, our method systematically approximates the multi-dimensional GLE without requiring direct estimates of complicated memory kernels. We show that this approach yields stable, high-fidelity reduced models for molecular systems, enabling significantly lower-dimensional simulations that nonetheless reproduce key statistical and dynamical properties of the original system.We then extend this framework to incorporate state-dependent memory kernels, facilitating enhanced sampling across diverse regions of phase space. We demonstrate that constructing heterogeneous memory kernels\u2014reflecting the local variations in unresolved degrees of freedom\u2014improves the model\u2019s accuracy and robustness, especially in systems exhibiting multiple metastable states. Through both numerical experiments and theoretical analysis, we highlight how these data-driven non-Markovian models outperform traditional Markovian or fixed-memory approaches.To address complex, multi-modal distributions in high-dimensional data, we then modify the latent variable of a KRNet normalizing-flow architecture from a single Gaussian to a mixture-of-Gaussians (MoG). This richer latent representation not only improves the model\u2019s expressiveness and training stability but also facilitates discovering collective variables (CVs), as the multi-modal latent space reveals distinct modes corresponding to relevant metastable states or slow degrees of freedom. Through both numerical experiments and theoretical analysis, we show that integrating a MoG prior into KRNet yields superior density estimation, enhanced sampling of metastable basins, and a more interpretable set of learned CVs.Altogether, this thesis provides a comprehensive methodology for deriving scalable, memory-embedded reduced dynamics augmented by advanced latent representations. Such models open new possibilities for multi-scale simulations by merging fine-grained molecular fidelity with tractable coarse-grained representations, all while systematically leveraging the benefits of multi-modal latent spaces to identify key low-dimensional features. Our results underscore the practical advantages of incorporating non-Markovian features and a mixture-based flow model in capturing the full complexity of real-world molecular and dynamical systems.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
AFROFUTURIST HORROR : AN EXPLORATION OF LIBERATION THROUGH BLACK HORROR
Get PDFThesis (Ph.D.)--Michigan State University. English - Doctor of Philosophy, 2025This dissertation is concerned with the growing project of Afrofuturism and its emphasis on visualizing a liberated Black future. Although Afrofuturism is continuing to grow as an aesthetic and critical thinking practice, in literature Afrofuturism tends to ground itself in science fiction and fantasy narratives. Thus, this dissertation fills the need for an Afrofuturist grounding in horror narratives with an emphasis on Black Horror as defined by Robin Means Coleman. Given this gap, as well as our current sociopolitical climate\u2019s myth of decolonization being obtained through non-violent means and a shaming of marginalized groups fighting for liberation, this project argues the importance of horror works in complexly imagining a liberated Black future. Using feminist, gender, and sexuality theories, definitions of the horror genre, and Afrofuturism this dissertation coalesces a theory tracing a Black Queer Horror Aesthetic called Afrofuturist Horror. I argue for and create a theory of reading Black Horror works grounded in Afrofuturism to create more nuanced and complex conversations about obtaining liberation that often uses violence and the grotesque. Specifically, this project uses Afrofuturist theories and definitions of horror to read Black Horror works ranging from vampire to slasher, and conjure narratives.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
ENGINEERING OF AN IMMUNOMODULATIVE NANODRUG FOR THERANOSTICS AND BIOMEDICAL APPLICATIONS
Get PDFThesis (Ph.D.)--Michigan State University. Biomedical Engineering - Doctor of Philosophy, 2025The immune system plays a critical role in many disease processes, and when it is functioning properly, it provides robust protection from both internal and external threats. However, when the immune system behaves inappropriately, chronic and potentially deadly diseases can occur. The treatment of these diseases, which range from rheumatoid arthritis to solid tumor cancers, is complicated by the fact that though the immune system is implicated, the mechanism of action is different between conditions. Specifically, some diseases are characterized by inflammation while others are characterized by immune suppression. Current treatments for inflammatory and anti-inflammatory conditions are insufficient to overcome the burden of these diseases since many patients either do not respond to treatment or suffer from severe side effects. However, nanomedicine, which remains underutilized, shows remarkable promise as an option for treating these diseases. Nanoceria, with its unique enzymatic properties, small size, and highly tunable synthesis, makes a promising candidate for the treatment of conditions in which macrophages play a major role. The focus of this project was the development of a nanoceria-based immunomodulative drug capable of driving the polarization of macrophages toward either a pro or anti-inflammatory state. Use of albumin and single-walled carbon nanotube substrates and variations in synthetic conditions allowed for the development of multiple formulations of the nanodrug with different properties including enzymatic activity, STAT3 inhibition, and targeting. Further modification of these particles can allow for the inclusion of fluorescence and photoacoustic contrast. Thus, by characterizing these nano-formulations and testing their effects in vitro and in vivo, we can develop highly effective immunomodulatory theranostics. We explore the potential of nanoceria as a diagnostic and treatment for endometriosis, a chronic inflammatory condition. Additionally, since nanoparticles offer high diagnostic specificity, it is possible to create novel imaging agents based on fluorescent silica nanoparticles, for diseases such as colorectal cancer which require enhanced imaging options. Ultimately, by utilizing the tunable properties of nanomaterials, we can create new diagnostics and therapeutics capable of improving the health of patients and enhancing their quality of life.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
ENHANCING READING COMPREHENSION IN SOCIAL STUDIES FOR STUDENTS WITH LEARNING DISABILITIES
No full textThesis (Ph.D.)--Michigan State University. Educational Psychology and Educational Technology - Doctor of Philosophy, 2025This dissertation includes a systematic review, an empirical study, and a practitioner article, all focused on improving reading comprehension and instruction for secondary students with learning disabilities (LD) in social studies. The evidence-based systematic review synthesized reading comprehension interventions for students with LD in secondary social studies classrooms published between 2011 and 2024. Only one intervention\u2014Collaborative Strategic Reading (CSR)\u2014was identified as an evidence-based practice (EBP). Findings also revealed limited content diversity in social studies and a need for replication studies to establish additional EBPs. The empirical study used an explanatory sequential mixed methods design to examine the perspectives of pre-service special education teachers seeking LD endorsements through a survey and focus groups. Participants (n = 51 survey; n = 10 focus group) generally valued social studies and reported comfort in teaching the subject, favoring discussion-based, collaborative approaches. However, it is possible that participants may have relied on general education instructional approaches, a focus of their teacher preparation program, to determine their comfortability. Despite feeling confident in teaching social studies, most participants lacked exposure to social studies-specific pedagogies and field experiences. The final practitioner article translates the findings of the EBP systematic review into practical guidance for implementing CSR in inclusive classrooms. CSR's four components\u2014Preview, Click and Clunk, Get the Gist, and Wrap-Up\u2014incorporate explicit instruction, peer collaboration, and scaffolding to support students\u2019 comprehension of primary sources. Together, the three studies underscore the promise of multicomponent reading interventions like CSR and highlight the need for enhanced disciplinary literacy training for pre-service special education teachers to support students with LD in accessing complex social studies content.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
In-person vs. virtual environments : Examining responses to workplace microaggressions
Get PDFThesis (M.A.)--Michigan State University. Psychology - Master of Arts, 2025As remote work remains a lasting feature of the modern workplace, it is critical to understand how this context influences employee responses to racial microaggressions. This study investigates whether the work environment (in-person versus virtual) shapes individuals\u2019 likelihood of confronting microaggressions, perceived responsibility to act, and expressions of allyship. A total of 295 employed adults were randomly assigned to view video-based workplace scenarios depicting subtle racial microaggressions in either an in-person or virtual setting. Participants were assessed on their intentions to engage in various allyship behaviors and rated their sense of personal responsibility to confront. Results provided partial support for the hypotheses. Participants in in-person contexts reported significantly higher overall allyship intentions and greater personal responsibility to confront compared to those in virtual settings, but this effect was observed only in one of two scenarios. Contrary to predictions, participants did not significantly prefer private over public support, and context did not moderate this preference. Exploratory analyses revealed Black participants and women reported higher levels of perceived responsibility to confront. Mediation analyses indicated that perceived similarity to the target explained racial differences in perceived responsibility, which in turn predicted stronger allyship intentions. The findings extend the Confronting Prejudiced Responses (CPR) model by showing how virtual contexts may disrupt key steps in the decision to confront, including harm recognition and urgency. They also highlight identity-based disparities in who feels obligated to act. Implications for diversity, equity, and inclusion (DEI) efforts are discussed.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
An Involution Satisfying Particle-In-Cell Method
Get PDFThesis (Ph.D.)--Michigan State University. Computational Mathematics, Science and Engineering - Doctor of Philosophy, 2025This thesis presents a new Particle-in-Cell method for numerically simulating plasmas under the Vlasov-Maxwell system. Maxwell's equations and the Newton-Lorentz force are both recast in terms of vector and scalar potentials under the Lorenz gauge. This results in a set of decoupled wave equations governing the potentials and a Hamiltonian system with a generalized momentum formulation governing the particles. The Particle-in-Cell framework for solving a plasma system requires two main components, a method for updating the fields and a method for updating the particles of the system.The first part of this thesis introduces the Method of Lines Transpose, or MOLT, as a way of solving partial differential equations in general and the wave equation in particular. Additionally it introduces a new particle pusher, the Improved Asymmetrical Euler Method, that is a modification of a previously existing method. We deploy these two techniques in the Particle-in-Cell framework. In this section in particular MOLT employs a dimensional splitting algorithm, solving a set of one dimensional boundary value problems using a Green's function. This will all be done using one particular temporal discretization scheme, the first order Backward Difference Formula. Numerical results are shown to give evidence for the quality of these techniques, though it is noteworthy that the combination of this wave solver and particle pusher does not satisfy the Lorenz gauge condition, nor does it satisfy the involutions of Maxwell's equations, otherwise known as Gauss's laws.The second part of this thesis fills this lacuna, suggesting two ways for doing so. First it will consider theory to connect satisfaction of the continuity equation with satisfaction of the Lorenz gauge. It will consider in particular a way of satisfying this theory with multi-dimensional Green's functions, eschewing the dimension splitting of the first part. It will additionally consider the solution of the boundary value problems via other numerical techniques such as the Fast Fourier Transform or Finite Difference approach, ultimately choosing these for simplicity. The second approach will consider a gauge correction technique. It will be shown that both of these preserve the gauge, but the first method will additionally satisfy the involutions of Maxwell's equations. In a similar manner to the first part, it will do so using the first order Backward Difference Formula as the temporal discretization scheme. Numerical evidence will be given to support the theory developed.The third part of this thesis will generalize the theory connecting the satisfaction of the continuity equation with satisfaction of the Lorenz gauge and, in most cases, with Gauss's Laws. It will extend this theory to not only all orders of the Backward Difference Formulation, but to a family of second order time centered methods, arbitrary stage diagonally implicit Runge-Kutta methods, and all orders of Adams-Bashforth methods. In all but the diagonally implicit Runge-Kutta methods, Gauss's laws will be shown to be satisfied if the Lorenz gauge is. Once again numerical evidence will be given to support this.Finally some future projects will be suggested to capitalize on this work.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references