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Demonstratives and the semantics–pragmatics interface
No full textOne of the most fundamental properties of language is its ability to refer to entities both in the world and those established in discourse. Across languages, speakers use a range of expressions to introduce, maintain, and distinguish referents. Among these, definite descriptions (for example, the book) and demonstrative descriptions (for example, that book) are two common ones that have been central to research on the semantics and pragmatics of nominal reference. Despite the considerable overlap in their distribution, demonstratives differ from definites in certain key aspects. This dissertation focuses on two cross-linguistically robust properties of demonstratives that distinguish them from definites: (i) their anti-uniqueness effect and (ii) their selective behavior in discourse anaphora. I examine these phenomena as a diagnostic window on the semantics–pragmatics interface, with the aim of clarifying the division of labor between grammatical meaning and discourse-level reasoning in the referential domain.
The first part of the dissertation examines anti-uniqueness, the constraint that makes the use of demonstratives infelicitous in inherently unique contexts (for example, #That sun is bright). Drawing on novel data from Bangla, I show that the anti-uniqueness effect extends beyond demonstratives to certain classes of definites. I argue in favor of the presuppositional approach to anti-uniqueness, illustrating that it is better suited than approaches based on pragmatic economy to account for typological variation in this domain. I then introduce a modalized implementation of the presupposition that offers broader empirical coverage.
The second part turns to discourse anaphora, introducing quantitative diagnostics for how definites and demonstratives are licensed across typologically diverse languages. Controlled experiments across English, Turkish, and Bangla reveal a consistent cross-linguistic asymmetry: demonstratives are uniquely sensitive to subtle information-structural contrasts, unlike definites. This empirical pattern isolates the pragmatic signature of demonstratives and provides a new experimental paradigm for testing competing theories of definite reference, particularly in languages whose definiteness systems are complex or remain under debate, as illustrated for Mandarin and German.
The final part extends this pragmatic paradigm to investigate whether discourse-level constraints on reference are computationally tractable in artificial language systems. Using nineteen large language models, I examine how model size and architecture affect their ability to encode these distinctions. I illustrate that larger models show remarkable sensitivity to the discourse-structural constraints of demonstratives and closely mirror human behavior, whereas smaller models do not. These results provide the first systematic assessment of discourse-pragmatic competence in large language models, showing that the fine-grained pragmatic distinctions underlying demonstrative use are not easily learnable from surface-level statistics alone and emerge only in more advanced models.
In sum, this dissertation integrates theoretical, experimental, and computational approaches to reveal how demonstratives illuminate the interaction between meaning and discourse across natural and artificial language systems. It (i) argues for a dissociation between the anti-uniqueness effects of referential expressions and their deictic component, and illustrates that the anti-uniqueness constraint is best analyzed as a semantically encoded feature, (ii) identifies the pragmatic constraints that govern demonstrative anaphora through cross-linguistic experimentation, establishing a robust empirical diagnostic, and (iii) evaluates how such discourse-level patterns emerge in large language models, providing a computational perspective on the semantics–pragmatics interface.Linguistic
Developing a chemogenetic oxidative damage model to phenocopy dry age-related macular degeneration
No full textThere is no cure for dry age-related macular degeneration (AMD), and research is challenging due to a lack of good animal models that accurately recapitulate the human disease. Because humans are the only species that develop the full form of AMD, studying its pathogenesis remains particularly challenging. To address this, we developed a chemogenetic oxidative stress model that mimics aspects of dry AMD using Cre-inducible D-amino acid oxidase (DAAO) transgenic mice. In this system, DAAO generates hydrogen peroxide upon exposure to its substrate, D-alanine, allowing spatial and temporal control of oxidative stress. By crossing DAAO mice with cell type specific Cre drivers, we induced oxidative damage selectively in the retinal pigment epithelium (RPE), rod photoreceptors, or vascular endothelial cells. We combined visual function tests (optomotor response and ERG), multimodal imaging (OCT, fundus, and fluorescein angiography), histology (flatmounts, H&E, and immunofluorescence), electron microscopy, and RNA-seq to characterize this model in RPE cells. Oxidative damage targeted to the RPE led to multiple AMD-like phenotypes, including vision loss, RPE and photoreceptor degeneration, hyperreflective foci, epithelial-mesenchymal transition, macrophage infiltration, mitochondrial damage, basal infolding loss, vacuolization, and complement activation. Additionally, we found that this phenotype could be prevented by Nrf2 overexpression by AAV-Best1-Nrf2 subretinal injections in neonates.
Additionally, by targeting the oxidative damage to various cell types, RPE, rod photoreceptors and vascular endothelial cells, we examined the autonomous and non-autonomous effects of oxidative stress in the eye. Inducing oxidative damage in the RPE caused degeneration of RPE cells and photoreceptors, and in severe cases, vascular leakage, indicating that oxidative stress in the RPE can elicit both intrinsic and extrinsic degenerative effects. In contrast, we found that targeting oxidative damage to the endothelial cells did not lead to vision loss, or degeneration of RPE or photoreceptors. However, when oxidative damage was directed to rod photoreceptors, low D-alanine concentrations led to RPE degeneration without rod loss, indicating non-autonomous oxidative damage in the eye. Taken together, these findings demonstrate that this chemogenetic model phenocopies dry AMD when targeted to the RPE and provides a powerful system to study cell-autonomous and non-autonomous oxidative damage in the eye.Biological and Biomedical Science
Anthropology in the Absence of the Human Soul: Abu’l-Ḥasan al-Ashʿarī’s Understanding of the Human Being in its Philosophical Context
No full textThis dissertation is an exploration of the philosophical anthropology of the eponymous founder of the Ashʿarī school of Islamic philosophy, Abu’l-Ḥasan al-Ashʿarī (d. 324/935-6). By “philosophical anthropology” I refer to the philosophical inquiry into the question of what human beings are, or what it means to be a human being – that is, the study of the ontology and metaphysics of the human being. A comprehensive understanding of al-Ashʿarī’s theory of the human being is not possible without knowledge of the more fundamental elements of his philosophy. For this reason, the first chapter of the dissertation is dedicated to al-Ashʿarī’s philosophy of language and the second to his ontology and general metaphysics. Once this groundwork is laid, the discussion moves on to the content of al-Ashʿarī’s anthropology: Chapter 3 presents the basic framework of his understanding of the human being. That understanding is contrasted with the many alternative anthropological models that were present in al-Ashʿarī’s time in order to show the kinds of views he was familiar with and declined to adopt. Chapter 4 introduces the idea that Al-Ashʿarī’s own model does not feature a concept of the human soul, where the human soul is understood to be a separable entity bearing the human being’s identity and performing other core functions related to human cognition, consciousness, and agency. Here, I argue that no possible conceptual candidates from the Islamic context, as al-Ashʿarī understands them, answer to the idea of a separable soul within his anthropology. Again, al-Ashʿarī’s understandings of these terms is compared with competing contemporary views thereon, revealing the philosophical alternatives that were available to him as he theorized about the various elements that make up the human being. The absence of a soul-concept in al-Ashʿarī’s anthropology raises the question of how he accounted for the human behaviors and characteristics that have been associated with such a concept throughout history. Chapter 5 addresses this issue, examining how al-Ashʿarī dealt with the phenomena often attributed to the soul. The chapter deals with questions of identity, persistence, eschatology, cognition, and agency. There, I cover al-Ashʿarī’s limited cardiocentrism, which assigns some of the functions one might associate with a human soul to the physical heart – not as a matter of metaphysical necessity, but rather as a function of how God chose to create human beings.
In order to reconstruct al-Ashʿarī’s anthropology, I rely primarily on Abū Bakr Muḥammad ibn Fūrak’s (d. 406/1015) Mujarrad maqālāt al-Shaykh Abi’l-Ḥasan al-Ashʿarī. In this text, Ibn Fūrak recounts the philosophical positions of al-Ashʿarī – the teacher of his teacher – in great detail. For knowledge of competing contemporary ideas al-Ashʿarī was familiar with, I rely on his doxography, Maqālāt al-Islāmiyyīn wa ikhtilāf al-muṣallīn. These texts are the ones that are best positioned to provide a strong representation of al-Ashʿarī’s positive philosophy and his knowledge of the philosophical positions of other parties. They are supplemented at times with supporting texts, including al-Ashʿarī’s al-Lumaʿ fi’l-radd ʿalā ahl al-zayghi wa’l-bidaʿ and the works of Abū al-Qāsim al-Anṣārī (d. 512/1118), a later Ashʿarī thinker who provides us with a perspective from the brink of the post-classical period. Other doxographical primary source texts as well as secondary sources are consulted to provide depth to al-Ashʿarī’s portrayals of other schools. However, these perspectives are usually presented in the footnotes, as the question of primary concern is not what those other parties actually believed but rather what al-Ashʿarī thought that they believed.
Efforts to understand and present al-Ashʿarī’s system of thought are valuable because his work in the 10th century helped shape the method, character, content, and boundaries of a massively influential school of thought that persists until our time. Al-Ashʿarī’s anthropology is both central to his thought and is also an excellent case study by which to examine the vast tapestry of his wider philosophy. It reveals the commonsense approach that would characterize the early period of Ashʿarī thought. The goal of this dissertation is to present that case study and, in doing so, to demonstrate the breadth and character of al-Ashʿarī’s personal philosophical system. Such a portrayal stands to enrich our understanding of his impact on the school that bears his name. Beyond this, it stands to lend some nuance to the study of the early period of Islamic philosophy and open up new avenues for discourse between kalām and modern philosophy.Near Eastern Languages and Civilization
Probing Quantum Geometric Phenomena in Antiferromagnetic Topological Insulators
No full textRecent advances in condensed matter physics have revealed that the geometry of
electronic wavefunctions—known as quantum geometry—plays a decisive role in shaping
diverse electronic, optical and transport phenomena. This dissertation explores how the
quantum geometric tensor, composed of its imaginary part (the Berry curvature) and
real part (the quantum metric), governs a new generation of Hall effects and nonlinear
responses in magnetic topological materials. Using the intrinsic antiferromagnetic
topological insulator MnBi2Te4 and its engineered van der Waals heterostructures, we
systematically investigate how symmetry, topology, and magnetism intertwine to produce
emergent Hall phenomena and functional nonlinear devices.
We begin by introducing the theoretical foundation of quantum geometry in
Bloch electron systems. The Berry curvature describes the rotational “twisting” of
electron wavefunctions in momentum space, underpinning classic phenomena such as the
anomalous and quantum Hall effects. In addition to this, the quantum metric describes
the local distance between nearby quantum states, reflecting the “shape” of the Hilbert
space. Whereas Berry curvature effects have long been associated with Hall responses,
the role of the quantum metric has remained largely elusive. In this paper, we explore the
effects of Berry curvature and quantum metric, presenting their manifestations including
the layer Hall effect, the nonlinear Hall effect, and the quantum anomalous Hall effect in
the MnBi2Te4 system.
Building on this theoretical framework, the dissertation reports the experimental
realization of the anomalous Hall signal in both even- and odd-layer MnBi2Te4
thin flakes. In even-layer samples, we demonstrate the layer Hall effect, where the
Berry curvature is locked to opposite layers of the antiferromagnet, allowing electrical
manipulation of the topological axion fields (E·B). This axion-controlled magnetoelectric
coupling permits switching between degenerate AFM states, representing a novel form
of electric control over topological magnetism. In odd-layer MnBi2Te4, we realize the
quantum anomalous Hall effect, characterized by a quantized Hall conductance
without external magnetic fields, thus completing the full topological phase diagram of
this material family. We further investigate its topology transition using an electric field
to break the layer degeneracy and detect a topology singularity.
We further extend these findings to a broader class of Hall phenomena in MnBi2Te4,
which is the experimental realization of the quantum metric dipole nonlinear Hall
effect in BP/MnBi2Te4 heterostructures. We successfully measure a second-harmonic
transverse voltage that depends on its antiferromagnetic states. By systematically
excluding alternative mechanisms—including Berry curvature dipole, skew scattering,
and Joule heating—we identify the observed effect as intrinsic to the quantum metric
dipole of the antiferromagnetic MnBi2Te4. The result represents the first clear electrical
detection of a quantum metric response, opening a new avenue for “quantum geometry
engineering” in van der Waals materials.
To disentangle overlapping transverse responses in complex materials, we develop a
unified experimental protocol to distinguish Hall and non-Hall transverse signals in
both linear and nonlinear regimes. By interchanging the current and voltage directions
and analyzing the symmetry or antisymmetry of the conductivity tensor (σyx and
σyxx), we can uniquely identify the geometric origin of the observed signals. Applying
this framework to MnBi2Te4, black phosphorus, and WTe2, we confirm that Hall-type
responses arise from Berry curvature or quantum metric dipoles, while non-Hall responses
emerge from anisotropic Drude mechanisms. This methodological advance provides a
general toolkit for probing quantum geometry in emergent quantum materials, especially
in the nonlinear regime.
In summary, this thesis bridges the conceptual gap between topology, symmetry,
and electronic geometry by revealing how quantum geometry manifests in both linear
and nonlinear transport. Through precision experiments, theoretical modeling, and
device engineering, it identifies MnBi2Te4 as a model system for exploring geometrydriven
electronic responses. The work establishes new directions for topological
antiferromagnetic spintronics, quantum geometry–based rectifiers, and future
quantum materials where electrical, magnetic, and geometrical degrees of freedom
are deeply intertwined. The discovery of the layer Hall effect, quantum metric
dipole nonlinear Hall effect and quantum anomalous Hall effect not only deepens
our understanding of quantum matter but also heralds a generation of self-powered,
geometry-controlled electronic devices.Physic
Structure and Function of Activated Transcription Elongation through Chromatin
No full textThe eukaryotic genome is organized into chromatin, whose basic unit consists of around 147
base pairs of DNA wrapped around a histone octamer core. This level of compaction becomes a barrier to
processes such as DNA replication or transcription. To overcome this barrier, transcription through
chromatin is regulated by several elongation factors, histone chaperones, and chromatin remodelers that
help RNA polymerase II (Pol II) progress through nucleosomes while maintaining chromatin structure.
This work investigates the role of the highly conserved IWS1 (interacts with SPT6 1), which is a histone
chaperone and core elongation factor, but its exact mechanism during transcription is unclear. Using cryo-
EM, we identify that a series of short linear motifs (SLiMs) within the disordered IWS1 C-terminus make
multiple contacts with the elongation complex. Biochemical assays reveal that the SLiMs are required for
transcription stimulation by IWS1 on linear and chromatinized DNA substrates. Further mutational studies
demonstrate that the extreme C-terminus of IWS1 is necessary for recruitment of IWS1 to the elongation
complex through its interaction with the RPB1 jaw. Due to the crucial role of the RPB1 jaw interaction in
IWS1 recruitment, we perform an AlphaFold-Multimer screen that reveals multiple other factors which also
bind to the RPB1 jaw. Then, we directly demonstrate that IWS1 protects the elongation complex from
transcriptional stalling induced by the helicase RECQL5 in a manner dependent on their RPB1 jaw
interactions. This work provides the structure of the most complete activated mammalian transcription
elongation complex, elucidates the function of the IWS1 C-terminus in chromatin transcription, and
presents a model for how Pol II is regulated through different transcription states.Biological and Biomedical Science
Policy Learning under Interference and Adaptively Collected Data
No full textArtificial intelligence has progressed significantly in the recent decades thanks to the wealth of available data and computational power. One area that has made great strides is policy learning, or the development of data-driven algorithms that learn optimal decision-making rules, for some objective of interest. These algorithms are applied across industry, driving the technology behind soccer-playing robots to large language models that give more realistic natural language responses. Despite its widespread use, there remain methodological gaps for effective use in public health. This dissertation addresses this gap proposing novel methods for policy learning under interference and adaptively collected data settings.
In Chapter 1, we propose an approach for optimal policy learning algorithm under bipartite network interference (BNI). BNI differs from classical causal inference settings in two ways: (i) the unit treated differs from the unit on which outcomes are observed, and (ii) the treatment exposure may spillover across multiple outcome units. We propose the first policy learning methods under BNI, providing statistical inference procedures and optimality guarantees. We then employ this methodology to study the optimal cost-constrained environmental policy for flue-gas desulfurization units, or scrubbers, onto coal fired power plants.
In Chapter 2, we build on the results from Chapter 1 to consider a different lens of policymaking under BNI. Numerous studies have shown that marginalized subgroups, such as low income or older communities, may experience disproportionate health burden from environmental exposures. We propose a novel fair policy learning methodology under BNI that minimizes welfare disparity between subgroups under the constraint of Pareto optimality. By framing fairness objectives under Pareto optimality, we ensure that subgroups cannot gain without inducing harm upon another group, staying in line with the principle of `first do no harm'. We employ this method to study fair, cost-effective scrubber allocations in the U.S. that balances mortality risk among high and low poverty subgroups, analyzing the tradeoffs needed to achieve fairness in environmental policymaking.
In Chapter 3, we shift gears to consider adaptively collected data settings. Despite its extensive use across mobile health and online advertising, many statistical questions on nonparametric estimation and inference remain. To that end, we study the problem of nonparametric regression under adaptively collected data settings, characterizing minimax optimal and rates. We then propose estimators which achieve minimax optimality, while permitting asymptotic normality and uniform inference under `high exploitation', regret minimizing settings. As an application, we extend the pseudo-outcome framework to permit conditional average treatment effect estimation and inference.Biostatistic
Learning, Optimization, and Control for Real-World Physical Systems
No full textRecent breakthroughs in machine learning and artificial intelligence have led to key advancements in many areas such as natural language understanding, game playing, and simulated locomotion. Two important algorithmic frameworks underpinning this success are reinforcement learning (RL) and data-driven, gradient-based optimization. Leveraging these RL and optimization frameworks for real-world physical systems, however, remains challenging: real systems yield limited data, rarely offer accurate analytical models, suffer from sim-to-real discrepancies, and often operate as large, interconnected networks. In this thesis, I seek to remedy these challenges in the following ways. First, I present a theoretically principled representation-based RL framework for stochastic nonlinear control which utilizes dynamics knowledge and structure to improve sample efficiency in RL. I will then discuss how this approach can be extended to the important challenge of scalable control in networked dynamical systems. Next, I will introduce efficient Bayesian and zeroth-order toolkits designed for sample-constrained black-box optimization, a pervasive challenge in many real-world engineering systems. Together, these contributions chart a path toward reliable, data-efficient learning-based optimization and control of complex real-world physical systems.Engineering and Applied Sciences - Applied Mat
A Metanational Modernism: Yannis Ritsos, Tradition, and the Poetics of Return
No full textMy dissertation explores the uses of Greek indigenous culture in the poetry of one of Greece’s most prolific modernists Yannis Ritsos (1909–90). My focus on his rehandling of the return theme offers a much-needed systematic reappraisal of the still widely held view that Greek modernism constituted a Hellenocentric movement distinct from an assumed cosmopolitan modernist standard in the West. Challenging this outdated and problematic distinction, I show that while Ritsos drew on substantially local and living traditions, his modulation of global meaning undermines claims for his “Generation’s” Hellenocentrism. Defining Ritsos’s approach to Greek culture in terms of a metanational modernism, I argue that his reinvention of the return theme not only contributed to a synchronic and synthesizing conceptualization of twentieth century Hellenicity but concurrently reinscribed the formal, ritual, and symbolic structures of his indigenous sources into viable modes for negotiating a dialogic interaction between Greekness and the larger discursive paradigms of literary modernism regarding history, modernity, and the poet’s universal significance within these socio-cultural matrices.
This study’s diachronic as well as synchronic discussion of Ritsos’s poetics of return represents one of the relatively few book-length explorations of his poetry, as well as the only one of its kind in the English language to undertake a close examination of his poetic engagement with tradition. Such a study is especially warranted in the wake of more recent shifts in the scholarly dialogue in which modernism is being explored as a transnational phenomenon with greater attention being devoted to the negotiation of cultural indigeneity and globality in American, European and many other underrepresented modernisms beyond this orbit. Ritsos’s metanational poetics of return is not only important for how it extends to a more wholistic assessment of Greek modernism but also for how such an approach to the Greek case may contribute to this ongoing reassessment of global modernism.
Grounded in the methodological frameworks of ritual poetics and mythogenesis, I approach Ritsos’s rehandling of the return theme primarily by his manipulation of the cultural and ritual deep structures of his indigenous sources, while also devoting comparative attention to a number of his modernist peers in Greece and abroad. I focus my discussion on three main categories that arguably represent Ritsos’s most recurrent frameworks of a poetics of return, and which represent major areas of interest to numerous other contemporaries: Christian journeys, the mourning process, and the dramatic and ritual underpinnings of Ritsos’s approach to classical mythology.Classic
Nature and Nation: Sociobiology and the Emergence of Feminist Science Critique in the Postwar United States
No full textThis dissertation expands and explores the archive of the 1970s-1980s “sociobiology debate” to redefine its political stakes, that far exceed academic impropriety and the emotions of two tenured Harvard professors, namely Edward O. Wilson and Richard C. Lewontin. It is a mistake to assume, this dissertation contends, that the sociobiology debate was merely an egomaniacal contest between two Ivy League personalities when in fact Wilson’s theories of human nature, that attracted opposition among political activists in the U.S. and abroad, were of consequence to the marginalization of women in the American workforce, the backlash against civil rights in the U.S. North, and the cultural power of the Left in Western higher education. An expanded archive reveals that this infamous scientific controversy was not only a significant iteration of the nature-nurture debate after the Second World War but also a conflict between Wilson and the radical science movement in the U.S. and elsewhere, whose Cold War valence cannot be ignored. We should, this dissertation suggests, understand the sociobiology debate as the story of the anticommunist repression – and subsequent deradicalization – of the radical science movement, that aimed to redirect science in the service of social benefit, during the Cold War. My study focuses on the American radical science movement in particular, and among sociobiology’s broad coalition of critics, I examine Science for the People (SftP), science feminists, and the International Committee Against Racism (InCAR). My work intervenes not only in the history of biology but also in the history of radical science. This dissertation makes the case that the archive of U.S. biology should include its suppression of science critique, and that the archive of radical science should, similarly, include its history of anticommunist repression. Ultimately, I pose the provocation that the real casualty of the sociobiology debate was not E.O. Wilson’s scientific reputation but the second wave of the radical science movement in the United States. Reckoning with this recent history, I conclude, is imperative to today’s efforts to correct the past wrongs of science, and reorient its course towards democracy and justice.History of Scienc
Programmable protein expression with RNA sensors
No full textRNA sequencing continues to reveal new cell type markers and gene expression profiles1. Biological tools that directly couple gene expression information to transgene expression are desirable for cell-type and state specific transgene expression. We developed Reprogrammable ADAR Sensors (RADARS), a technology that uses base-pairing and RNA editing by adenosine deaminases acting on RNA (ADAR) to translate a transgene cargo only in cells with target RNA expression. RADARS is reprogrammable based on RNA target sequence, which positions RADARS to deliver therapeutic cargoes to diseased cell-types or tissues that exhibit unique RNA expression, such as cancer. Many cancer types have unique fusion RNAs as consequence of gene fusions, which arise through somatic structural variation and often drive cancer progression. Given their cancer-specificity, targeting fusions has precedent in oncology–yet many cancers driven by fusions do not have targeted therapies. We hypothesize that RADARS can leverage cancer specific RNA fusions as therapeutic vulnerabilities. We tested the selective activation of cell killing payloads using RADARS against three clinically relevant fusion RNA classes: (1) a driver fusion in fibrolamellar hepatocellular carcinoma; (2) gene fusions found in therapy-resistant metastatic breast cancer; (3) endogenous fusion RNAs in breast cancer lines. Preliminary data suggest that fusion RNAs may serve as conditional biomolecules for delivering cancer-killing protein payloads.Biology, Molecular and Cellula