Dissertations

Naphthalene diimide (NDI) is a powerful excited-stated photoxidant that has enabled light-triggered oxidative processes to be investigated. In this dissertation, the synthetic and spectroscopic tunability of NDI is leveraged to underpin several essential biological energy transduction mechanisms, including pure electron transfer (ET), concerted proton coupled electron transfer (PCET), sequential electron transfer followed by proton transfer (ET-PT), and ratcheted ET. The ultimate goal of this work is to build energy transduction function from scratch in bioinspired de novo proteins that orchestrate the movement of electrons (e-s), holes (h+s), and protons (H+s) to redox-active amino acids using bound cofactors. This work leverages both experiment and theory to achieve this goal. The molecular energy transduction work outlined in this dissertation is currently being used to design de novo proteins that independently control the light-triggered flow of e-s, h+s, and H+s to enable both concerted and sequential flow of these charges. The presented work underpins the energy-transduction function of natural proteins, such as Photosystem II, and establishes the groundwork to engineer soft materials that produce high potential photoproducts, possess novel electro-optic function, and transduce energy via designed ET and PT pathways.

An aspect of ovary structure and function that has been given little attention is the rete ovarii (RO). Although the RO appears in drawings of the ovary in early versions of Gray’s Anatomy, it has disappeared from recent textbooks, and often is dismissed as a ‘functionless vestige’ of the adult ovary. The role, function, and development of the RO have largely evaded understanding by scientists for the past 154 years since its first description. In the process of studying ovarian morphological development, we identified a marker, PAX8, that strongly labels the RO and reveals that it is an actively developing tripartite structure consisting of the intraovarian (IOR), connecting (CR), and extraovarian rete (EOR), all three of which persist in adult life. The early RO develops within the mesonephros, alongside the Wolffian and Müllerian duct. Although both the male (Wolffian) and female (Müllerian) ductal primordia are present at the outset of gonadogenesis, only one of the two ductal systems develops. Once the male pathway is initiated, testis cells produce Anti-Mullerian hormone (AMH), leading to Müllerian ductal degeneration, and testosterone, promoting the development of the Wolffian duct and mesonephric tubules into the Rete Testis (RT), the efferent ductules, and the epididymis. In contrast, during female development, AMH is absent, and the Müllerian duct differentiates into the oviduct and uterus. These findings led to the idea that the mesonephric ducts are exclusively “male” primordia, while the Müllerian ducts are exclusively “female” primordia. This interpretation was consistent with the old idea that the RO was a degenerating structure derived from remnants of the mesonephric tubules still detectable in females. Using confocal imaging we found that the RO derives from the mesonephric tubules, but also from the first segment of the main Wolffian duct thought to only persist in XY as the Wolffian duct. We found that the Wolffian duct is severed during establishment of the RO to create the blind ended EOR, indicating the persistence of the “male” ductal system in the female reproductive tract. We also found bridges of cells from the Mullerian rudiment toward the presumptive CR (XX) and efferent ductules (XY), suggesting the intermingling of Müllerian Duct and mesonephric tubule cells in both sexes. This alters the paradigm that the mesonephric duct is exclusively a male-specific structure, while the Müllerian duct is exclusively a female-specific structure.The function and role of the RO previously heavily relied on histology and serial sections – leading to a confusion on the description and function of the RO. Some early histology of the structure, and work presented here, suggest that cells of the EOR are secretory. Using microinjections into the EOR, we found that it is fluid-filled and that luminal contents flow towards the ovary. Using proteomics and transcriptomics we found that the EOR produces proteins that are essential for ovarian function and homeostasis. These proteins, among others, are hormonally regulated. Labelling for cellular component markers revealed that a subset of the epithelial cells of the EOR are ciliated and exhibit cellular trafficking capabilities. Labelling for innervation and vasculature revealed that the cells of the EOR are closely associated with neuronal projections and vasculature. The direct proximity of the RO to the ovary suggest that it is functionally linked to the ovary and may play an important role in ovary development and homeostasis. Based on the cell biology, transcriptome and proteome of the RO,I hypothesize that the RO acts as an antennae for the ovary and plays an important role in ovary homeostasis and fertility.

This dissertation demonstrates that the development of monumental public architecture occurred contemporaneously in urban centers of both Latium and Etruria in the late 6th century BC and argues that its catalyst was a profound shift in socio-political organization that took place throughout Central Italy. It analyses these developments through a lens of spatial theory, especially that of environment behavior studies, to understand how they impacted urban societies of Central Italy. The link between the construction of novel public structures in the Roman Forum and the political upheaval of the late 6th century BC has been well established in previous scholarship. New architectural forms lent shape to the Forum, providing the built environment of Rome with an explicitly public space reflective of its new Republican organization. Yet it was not an isolated phenomenon. It can be detected in the urban form of several contemporaneous Latin and Etruscan cities. While the historical record of these cities is far less robust than that of Rome, their archaeological record supports the conclusion that a similar political shift transpired across the larger region of Central Italy during the late 6th and early 5th centuries. In addition to Rome, cities such as Satricum, Caere, and Vulci constructed monumental tripartite temples, public squares, and assembly halls for the first time. These structures appear as a linked assembly and are innovative in their architectural form, but more importantly in their conceptual configuration as explicitly public structures. They not only facilitated the habitual behaviors of the offices of state and citizen bodies that were gradually introduced during this period but also symbolically represented the authority of the state itself. Previously, the regiae and domestic courtyard complexes of local rulers had served as loci for both private and public activity in early archaic cities. The newfound spatial delineation between public and private is reflective of the elaboration of state level organization that saw individual identity and political authority formally separated through the institution of official offices.

Contests over Contraception in Late Twentieth-Century Mexico follows how the birth control pill became immoral and centers Mexican Catholics in this history. From the early 1960s to the early 1970s, Mexican Catholic bishops, priests, and married couples debated the morality of the pill. Because the pill was primarily a hormonal invention, as opposed to a barrier method, it inspired many questions and debates about the purpose of sex. In the 1960s, the Church was reevaluating its doctrine—including its approach to sex and marriage—amidst modernization, social change, and cultural upheaval. Instead of assuming a monolithic Mexican Church, Contests over Contraception centers on the diversity of Catholic actors and their ideas. I argue that at the heart of these pluralistic debates about the morality of the pill was the contested place of nonprocreative sex in marriage, otherwise known as conjugality, marital intimacy, and pleasure. My work places the question of marital intimacy at the center of these debates, unsettling many of the dominant narratives about the Church in Mexico and Latin America in this period: a critic of economic oppression or a defender of family values. Just as much as the very real economic circumstances led many Mexicans to be concerned with family size, this concern was not mutually exclusive with concerns over marital intimacy and pleasure, as often inadvertently assumed. The fear of couples resorting to abortion was powerful enough to reconcile many of these different concerns and push Mexican Catholics to consider approving the pill.This dissertation demonstrates that this history is much more than one of Catholic dissent or obedience in response to the Pope's prohibition of the pill in 1968. When we turn to Mexico, we see that these debates were about how couples, not individuals, made these decisions about their reproductive lives together. And so, marital intimacy—when and why couples should have sex and whether the pill could facilitate this process—was an important one. Concerns over economic circumstances only raised the stakes. This research suggests that the question of birth control is distinct from abortion, and invites a different set of questions, especially when studied in Mexico. Contemporary terminology used to discuss sexuality and reproduction (such as left/right or pro-life/pro-choice) did not apply to these complex debates in the 1960s. Centering on how Mexican Catholics conceived of conjugality, or pleasure between spouses, moves away from the equally important focus of individual rights and autonomy when discussing reproduction and sexuality. Historicizing how and when the pill became immoral in Mexico suggests reproductive matters were politicized at different rates across the world.

Many scientific and operational challenges exist in evaluating and modeling the coupling of a complex, heterogeneous surface with the overlying turbulent atmosphere. Traditional models for the interaction between the atmospheric boundary layer (ABL) and the underlying surface rely on widely applied assumptions of homogeneity and stationarity, despite the fact that these are regularly violated in natural systems. A number of important processes are modeled poorly in models due to the dismissal of the significant influence of surface and atmospheric heterogeneity. In this work, we look at how both atmospheric surface layer turbulence (ASL) and ABL turbulence can be better parameterized in earth system models (ESMs) and numerical weather prediction schemes (NWPs). In the ASL, where the dominant Monin-Obukhov Similarity Theory is applied, we examine MOST based models of potential temperature variance in the first chapter and show how heterogeneity correlates with poorer accuracy of MOST based models using the National Ecological Observation Network (NEON) of eddy-flux towers. The variances of other atmospheric variables, including the velocity components, moisture and carbon dioxide, are then examined. This analysis shows opportunities for model improvement using higher order turbulence statistics, specific the anisotropy of turbulence, to address the shortcomings of traditional MOST relations through a generalized form proposed by Stiperski and Calaf. In the ABL, I examine the issues of circulations driven by spatial gradients of surface fluxes. In large scale models these circulations, analogous to sea breezes, are sub-grid and therefore need to be parameterized, a task yet to be accomplished by the modeling community. In this chapter, I develop a two-column model for sub-grid thermally driven circulations and compare them to large-eddy simulations (LES) of heterogeneous and homogeneous surfaces. The work qualitatively reproduces the impacts observed in LES runs, and provides a route for implementation in multi-plume schemes in ESMs. Continental scale impacts of discarding surface heterogeneity are also explored. 3km WRF simulations of the Continental United States over three summers, one set of simulations where fluxes are averaged to some scale to mimic the averaging that occurs with tiling approaches in ESMs and another set with no flux averaging, show that reduced representation of surface heterogeneity can change long term precipitation statistics and patterns of mesoscale flow in models, with some regions experiencing a doubling of precipitation due to flux homogenization at a 60 kilometer scale. The sum of this work shows that accurate representation of the heterogeneous coupling between the land and atmosphere is necessary for development of realistic climate and weather simulations, and contributes to development of new model parameterizations.

The frontal eye field (FEF) is the primary cortical output for generating saccadic eye movements. FEF neurons that respond to visual stimulation display three fundamental types of movement sensitivity. First, they are often tuned to movement, as well, specifically for saccades toward their receptive field. Second, for many neurons, their receptive fields shift to their post-saccadic location around the time of a saccade. Finally, they can exhibit an enhanced response to visual stimuli which are the target of a saccade. Our objective was to determine how FEF visual responses and their associated movement-related sensitivities are shaped by learning. First, we present a model of oculomotor visuomotor responses that accounts, at the single neuron level, for all three motor-related phenomena through a single mechanism: learning to anticipate their input activity. Second, we tested the predictions of our model in vivo. FEF neural activity is typically examined after extensive training of the animal to establish stable, predictable behaviors. In natural behaviors, the appropriate motor responses depend on contextual characteristics such as reward, timing, and prior behaviors, all of which can change frequently and unexpectedly. We recorded from single neurons in the FEF of monkeys and investigated how FEF cognitive signals changed during a variety of behavioral contexts, and ultimately concluded that the signals are adjusted through a simple reinforcement learning rule. The results suggest that FEF and connected structures may integrate cortical inputs with motor commands and information about reward to compute a signal for the guidance of learning. Taken together, these studies lay the groundwork for future research to determine fully the learning rules implemented by FEF.

From batteries to bones, rocks to concrete, porous materials are ubiquitous in the natural and engineered environment, yet remain elusive in their characterization. One of the fundamental challenges of studying porous materials comes down to a fundamental question of linking the microscale to the mesoscale. This work addresses two primary linkages for analysis--the chemical response and the mechanical response of the material. Minkowski functionals served as the primary vessel for understanding how material microstructural geometry ties to macroscale energetics. In the case of chemical systems, Minkowski functionals proved to be powerful predictive tools in both reaction steady states and reaction dynamics. These exponential linkage to morphometers serves as a basis for understanding how the interfacial geometry of system affects the non-mixed chemical behavior of said system over time.As a study on novel simulation frameworks for modeling discrete chemical behavior at the microstructural scale, this work also introduces a unique means for modeling interface chemistry--surface CRNs. Surface CRNs are asynchronous cellular automata models similar to Markov chain models. This class of simulator efficiently translates complex chemical behavior into relatively easy-to-follow reaction rules. This class of simulator has proven to be surprisingly accurate despite its simplicity, creating a strong basis for understanding chemical behavior at a discrete level. While one half of this work focused on the ability of Minkowski functionals to predict chemical behavior, the other half of this work focuses on their ability to link to the mechanics of a microstructure. To address the mechanics problem, Minkowski functionals were extracted from 3D x-ray tomographic scans and assessed mechanically via 3D printed and digitally modeled strength assessments. Ultimately, a deep learning model was trained that could accurately predict and recreate the mechanical response profile of a digitally simulated porous microstructure from just four Minkowski functionals. This extended further to 3D printed samples, allowing for the mechanical behavior of physical samples to be predicted just from its geometric descriptors.

The term “unknown” no longer merely refers to a subjective judgment indicating a stable and conceivable fact or object “in the world.” Nor does it only describe a mathematical or scientific variable that can be calculated and predicted in relation to the consistent properties or timeless truths about reality. This dissertation investigates the multiple and contested meanings of the term in ecology, security, and computational design which taken together, are suggestive of an ontological and epistemological transformation in conceiving of the relation between the environment and technology already initiated with mid-20th century cybernetic and information theories. At the heart of this reconfiguration: “life itself” is mobilized as a post-human form of computational knowledge that can be stretched to embrace indeterminacy and the unknown, fueled by a planetary nomos. As with 21st century media like accelerated computing and artificial intelligence, the environment is no longer merely modified with technologies, but is increasingly constituted by future-oriented forms of algorithmic mediation that are explored here in the larger scope of the material and environmental impacts of technology.

Instead of following the work of a specific thinker, the project undertakes an interdisciplinary reevaluation of Cold War cybernetic ontologies in the literary post-humanities, new media art and design, affect theory, and media ecology, tracing how the passage of cybernetic metaphors into the global cultural imaginary is symptomatic of an ecological reconfiguration in the way technology is accumulated as power, knowledge, and capital. Specifically, it describes how the becoming environmental of computation also entails the remediation of a history of colonial extraction and subjugation in more reticular and algorithmic forms like neural networks and intelligent design, proffering mutations as technics that redeploy the Enlightenment political and metaphysical project of the Anthropos as relational ontologies and vitalist ecological politics. The project reevaluates the rejection of the anthropos in totalizing theoretical ecologism, given the resonances of the discourse with both neoliberal political ecology and the American and European far Right where the production of life is used legitimate techno-cybernetic extraction and violence.

Against the dominant themes of new materialist media theory and affect theory, the project develops a critique of media ecology. It draws on feminist materialist and postcolonial understandings of subjectivity and sovereignty to argue that the “unknown” is no longer a technological problem to be overcome, but rather, is primarily an aesthetic phenomenon that operates at the level of material affect and environmental sense-making. Using both theoretical inquiry and case studies drawn from new media art practices and digital culture, I draw two implications of this shift for political thought: first, it is necessary to address how changes in sociality and politics in the era of accelerated and planetary computing technologies relate to transformations to the subjective characteristics of race, gender, sexuality, and ethnicity beyond the individual body, population, or nation-state; second, such reconsiderations of subjectivity may help to politicize the role of contingency and unknowability in digital environments and in the speculation of technological futures.

Blood cancers are among the most common types of malignancies. Over 175,000 new cases of blood cancers representing over one hundred distinct malignancies were diagnosed in the United States in 2023. Understanding the molecular determinants underlying the origin of these malignancies and their response to treatment is essential to improving diagnostic accuracy and identifying the most promising therapeutic options for patients. This dissertation aims to determine molecular profiles associated with treatment response and normal cell of origin using data drawn from the landscape of genetic alterations in blood cancers.

Diffuse large B cell lymphoma (DLBCL) is the most common form of blood cancer with over 18,000 new cases diagnosed every year in the United States. The treatment for DLBCL has remained unchanged for over two decades, and a large subset of patients are refractory to treatment or relapse after initial response. Patients with relapsed/refractory disease (rrDLBCL) have a dismal prognosis. The approval of chimeric antigen receptor T-cell (CAR-T) therapy has greatly improved the odds of survival for these patients. However, not all patients treated with CAR-T therapy experience prolonged remission. In Chapter 2, I describe my work towards understanding the genetic determinants of response in a real-world dataset of patients treated with CAR-T therapy, identifying clinical factors and gene expression signatures relevant to prognosis after treatment.

Genomic profiling efforts for blood cancers have thus far been limited to the most common entities, and the heterogeneity in processing and methods between these studies hinders comparison between different malignancies. In Chapter 3, I describe my work on the Atlas of Blood Cancer Genomes (ABCG) project, a comprehensive profiling study of all blood cancers described in the World Health Organization classification. In the first half of this chapter, I describe the design and development of tools and methods to explore the genomic landscape of blood cancers. In the second half of this chapter, I highlight the application of these methods to three distinct blood cancers – primary mediastinal B cell lymphoma, extranodal marginal zone lymphoma, and blastic plasmacytoid dendritic cell neoplasm – with very different molecular and clinical features that highlight the diversity of blood cancers.

A tumor cell often closely resembles the normal cell it originates from in terms of its gene expression profiles, surface marker expression and cellular behavior. As a result, surface markers from normal cells are commonly used to diagnose cancers using flow cytometry. However, the normal cell of origin for some blood cancers such as marginal zone lymphoma (MZL) has not been comprehensively characterized. In Chapter 4, I discuss the work I performed to determine the cell of origin of MZL, highlighting two potential subsets of MZL and their putative cells of origin.

Overall, this dissertation explores how an understanding of the genetics of blood cancers can address fundamental questions related to their origin, characterization, and response to treatment.

Staphylococcus aureus forms biofilms in a variety of human infections. These infections span a wide range of environments in the body. The environment of the infection determines the physiological state of the bacteria. There exists a gap between studying biofilms in a laboratory setting and the physiology of cells in a clinical biofilm. To bridge this gap, we designed a high-throughput biofilm assay to mimic the environment of a clinical infection. Using this assay, we measured the formation of two different classes of biofilms in five clinical isolates. These two classes of biofilms differed in their location: the ring class formed at the air-water interface on the sides of the wells and the bottom class formed at the bottom of the wells. Each class exhibited different phenotypes in response to environmental demands. Biofilms were grown aerobically and anaerobically on plasma-coated surfaces to evaluate the role of environmental oxygen. Protein A (SpA) and polysaccharide amounts were analyzed to elucidate the relationship between proteins, polysaccharides, and biomass accumulation in these two classes of biofilms. The bottom biofilms were disrupted by degradation of polysaccharides, enhanced under hypoxic environments, and their SpA content increased inversely with biomass. In contrast, the ring biofilms were not disrupted by polysaccharide degradation, were enhanced under aerobic environments and their SpA content increased proportionally with biomass. Furthermore, SpA promotion of biofilm formation in ring biofilms was found to be limited to biofilms grown aerobically. Additionally, some results depended on whether the strains were nasal or pathogenic isolates. The results of this study suggest that the influence of environmental and genetic factors on biofilms changes with the physiological state of the biofilm. Because the location of biofilms in S. aureus diseases in patients vary in their environment, our ability to observe these two different classes provides useful insight. This study also evaluated the mechanism by which SpA promotes aerobic ring biofilms. We measured SpA binding to several biofilm matrix components. Isothermal titration calorimetry (ITC) analysis revealed that SpA binds preferentially to β-linked polysaccharides, in particular the major biofilm exopolysaccharide poly-β-1,6-N-acetylglucosamine (PNAG). Biolayer interferometry (BLI) revealed that the multivalency of SpA increases the apparent affinity for β-linked glucans. BLI results also indicated preferential binding of SpA to β-1,6 linked glucans, as shown by ITC, but suggests that SpA can facilitate weaker interactions with the other β-linked glucans. Therefore, we propose that SpA-PNAG binding facilitates cellular aggregation and promotes biofilm formation. Additionally, we proposed that SpA binds other β-linked glucans secreted by other organisms facilitating cellular adhesion in multispecies biofilm infections. Understanding the role of SpA in both single- and multispecies biofilms is important to targeting and combating these types of infections.

Wound healing is a vastly complicated process. While this can be said about many biological functions in the body, wounds present a particularly difficult problem due to their inherent irregularity or uniqueness. Because different wounds behave and heal differently, or not at all, different therapies must be developed to treat them effectively. The research presented here details several approaches to progress not only the entire field of wound healing research, but also focuses on hydrogel technology improvements. Using titanium 3D printing, cap-able splints were constructed to not only ease the surgical process but also enable efficient daily wound access for treatment administration or wound tracking over time without the need to completely undress and redress the wound. The titanium splints did prove effective for daily monitoring but did still require some surgical prowess. To remove the need for surgical skills, an adhesive wound splint was developed by incorporating ethoxylated polyethyleneimine (EO-PEI) into the traditional polydimethylsiloxane (PDMS) polymer recipe resulting in adhesive PDMS (aPDMS). The aPDMS splints drastically reduced surgery time per animal without compromising wound splinting performance. Traditional bulk hydrogels have been used in wound healing research but have yet to be clinically implemented in a widespread manner due in part to their resistance to cellular infiltration or integration with the host. Using hyaluronidase (HAase) on a hyaluronic acid (HA) based hydrogels to partially degrade the surface of bulk gels yielded a looser nano-scale mesh size that enhanced cellular infiltration into the gel and granted better access to nanoparticle therapy loaded within. Finally, a biologically active viscous salve loaded with heavy chains (HC) of the serum protein Inter-α Inhibitor (IαI) was designed to leverage HC’s ability to mitigate the inflammatory response such that normal wound healing regeneration could ensue.

Traditionally, statistical data has been in the form of elements of Euclidean space. However, as data complexity increases, it is assumed to lie on lower dimensional non-linear space such as smooth manifolds, in what is known as the manifold hypothesis. Nonetheless, real-world data is not always in the form of smooth manifolds but, in general, can lie on stratified spaces. In this thesis, we explore the geometry of stratified spaces with the overall objective of enabling statistics on these spaces. More specifically, we provide answers to the following two problems.

A fundamental task in object recognition is to identify when two shapes are similar. One approach to rendering this as a precise mathematical problem is to look at the space of all shapes and define a metric on it. This approach has been taken by renowned statisticians and mathematicians like Kendall, Grenander, Mumford, Michor, and others. In this thesis, we provide an algebraic construction of the moduli space of shapes and define metrics on it with the objective of developing a statistical theory on shapes. The construction is far more general than existing constructions, as it doesn't restrict `shapes' to smooth manifolds and includes a broad category of spaces, including many stratified spaces. The foundation of this construction relies on the topological analogue of the Radon transform, building on the work of Schapira who showed that such transforms are injective.

This thesis also provides a starting point for developing a theory of diffusion processes on general stratified spaces. On Euclidean spaces, Brownian motion is constructed by taking scaled limits of random walks. This approach is challenging because stratified spaces are not only non-linear and lack addition but also the tangent spaces of stratified spaces are non-linear, unlike smooth manifolds. So, instead, we define Brownian motion on stratified spaces by taking appropriate limits of Dirichlet forms. Sturm took this approach for general metric measure spaces, where he came up with a measure-theoretic condition required for these Dirichlet forms to converge properly. We prove this is the case for certain compact subanalytic spaces.

Parts of the thesis are based on joint work with Justin Curry and Sayan Mukherjee.

In recent years, especially in the wake of the COVID-19 pandemic and the challenges posed by climate change, political theorists and organizers have directed their attention towards the “crisis of care.” The crisis of care refers to a generalized yet unevenly distributed breakdown in the ability to maintain social, ecological, and political systems. The consequences of this crises are multifarious, harming underrepresented minorities and workers, health and education services, the natural environment, and the institutions of liberal democracy. Feminist care theorists have analyzed these interlocking crises of care from a variety of perspectives, criticizing the way care is distributed in a capitalist society, and even postulating the need to care for human and non-human entities that are interconnected through relations of interdependence. Nevertheless, the question of how to enact a politics of care remains open from theoretical and practical perspectives. “The Politics of Care: Feminist Infrastructures of Love and Labor” addresses this question by examining how a politics of care is produced as an effect of the interdependence between Global South and Global North, nature and culture, human and non-human. To do so, this dissertation critically reexamines the archives of two prominent strands of feminist thought: posthumanism (including decolonial critiques from Central and South America) and Marxist feminism (including critical race theories). It uses the methods of feminist political theory, film, and literary studies in Italian, Spanish and English. The results of the research are threefold. First, I argue for the inseparability of the strategies of love and labor, of regenerative politics and conflictual politics in organizing struggles over care. Second, I track the feminist function (how visions of gender and race emerge) within those struggles and theoretical archives. Third, I argue for the need for feminist infrastructures, and for a transnational understanding of care that is open to influences and practices from the Global North and Global South. Working across the divide between regions of the world, human and non-human, natural and technical, love and labor, “The Politics of Care” offers a complex view of interdependence conceived as infrastructure as a tool for organizing the politics of care.

This dissertation studies macroeconomics and information theory. Each essay investigates the effects of imperfect information processing on macroeconomics, international finance, and social welfare, even when the information is transmitted accurately but not processed perfectly by the recipients.

In Chapter 2, I explore the underlying reasons for the rapid spread of financial contagion across markets with weak correlations using a dynamic model of rational inattention. In my model, agents invest in two assets, whose returns are uncorrelated. Monitoring the returns on these assets entails costly information acquisition. Unlike in past work, I allow for the total amount of information that the investor acquires to endogenously respond to the change in volatility of assets' returns. By emphasizing the decomposition of attention rather than the relative signal weights of the two assets in the optimal signal, I find that increased volatility of one asset's returns heightens not only investor attention to that asset (as past research has found), but also to attention to other assets as well (counter to the conclusions of existing research), as a result of the increased subjective correlation. I validate these predictions using the text from the Financial Times during the 1997 Asian Financial Crisis. Furthermore, the theoretical results provide general mechanisms of volatility spillover in the canonical rational inattention model and the pivotal role of information structure choice in these processes.

In Chapter 3, I examine the relationship between news media credibility, information friction, and strategic complementarity, especially during uncertain times like the COVID-19 pandemic. It introduces a news media verification mechanism to the Beauty Contest model and discusses the effects of an endogenous information cost model on the reliability perception of public information and social welfare. The study highlights how increased information costs and high strategic complementarity might reduce efforts to verify public information, potentially leading to undervalued news media credibility and increased belief polarization. It suggests that, contradicting the insights of Morris and Shin (2002), improving news media trustworthiness or accuracy of public information could almost always enhance social welfare, urging the need for empirical research to further understand the news media's impact on economic outcomes and policy-making.