VictorJuiz/thesis huggingface dataset:
Essays on the Economics of Crop and Livestock Insurance

This dissertation looks at the effect of participating in crop and livestock insurance on many aspects of farmers' business decision making. In Chapter 2, we investigate the effect of crop insurance enrollment on contract terms and farmers' participation in marketing contracts. Our model shows that improved terms of crop insurance (lower premium, higher subsidy) make contracts less appealing to farmers as mechanisms to mitigate risk. Therefore, intermediaries may revise their contract offers so that they are more attractive. However, improvements in contract terms are limited by their cost to the intermediaries, and will not lead to expanded participation in contracts. Thus, improved insurance terms may not crowd out participation in contracts, but will not expand participation either. In Chapter 3, we use various data sources and 2SLS to empirically test the predictions out of the model we developed in Chapter 2. Specifically, we look at how crop insurance enrollment affects farmers' share of value of production under marketing contracts. We construct a pseudo panel out of the repeated observations from the agricultural and resource management survey (ARMS) data. We use lagged county level subsidy and total precipitation as IVs for insurance enrollment. The second stage result indicates that, in peanut sector, farms with higher possibility of insurance enrollment will have more share of value of production under marketing contracts as well. In Chapter 4, we explore the relationship between farmers' use of livestock insurance and debt use. Risk balancing hypothesis (RBH) suggests that an exogenous reduction in farm's business risk would result in farmers taking more financial risk. We utilize a natural experiment from Jiyuan city in Henan province, China and regression discontinuity design approach to test the RBH. Our empirical results suggest that, farmers that are selected into the compulsory hog insurance program are 20 percent more likely to be willing to take debt than those who are not. Meanwhile, the difference of probability of taking debt between the two groups is insignificant. The combination of the two results indicates that farmers are willing to take more debt after insurance is available. However, the presence of credit constraint prevents them from taking more debt.

Advisor: Zilberman, David
Manipulation-resistant online learning

Learning algorithms are now routinely applied to data aggregated from millions of untrusted users, including reviews and feedback that are used to define learning systems’ objectives. If some of these users behave manipulatively, traditional learning algorithms offer almost no performance guarantee to the “honest” users of the system. This dissertation begins to fill in this gap./nOur starting point is the traditional online learning model. In this setting a learner makes a series of decisions, receives a loss after each decision, and aims to achieve a total loss which is nearly as low as if they had chosen the best fixed decision-making strategy in hindsight./nWe extend this model by introducing a set of users U. Each of the learner’s decisions is made on behalf of a particular user u ∈ U, and u reports the loss they incur from the decision. We assume that there is some (unknown ) set of “honest” users H ⊂ U, who report their losses honestly, while the other users may behave adversarially. Our goal is to ensure that the total loss incurred by users in H is nearly as small as if all users in H had used the single best fixed decision-making strategy in hindsight. We say that an algorithm is manipulation-resistant if it achieves a bound of this form./nThis dissertation proposes and analyzes manipulation-resistant algorithms for prediction with expert advice, contextual bandits, and collaborative filtering. These algorithms guarantee that the honest users perform nearly as well as if they had known each others’ identities in advance, pooled all of their data, and then used a traditional learning algorithm. This bounds the total amount of damage that can be done per manipulative user. More significantly, we give bounds that can be considerably smaller in the realistic setting where the users are vertices of a graph (such as a social graph) with disproportionately few edges between honest and manipulative users./nAs a key technical ingredient, we introduce the problem of online local learning, and propose a novel semidefinite programming algorithm for this problem. This algorithm allows us to effectively perform online learning over the exponentially large space of all possible sets H ⊂ U, and as a side-effect provides the first asymptotically optimal algorithm for online max cut.

Advisor: Vazirani, Umesh
Cotton Framed Revolutionaries: T-shirt Culture and the Black Protest Tradition

In the proceeding chapters, I examine protest t-shirts that incorporate graphic representations of movement photography, symbols, and slogans from 1965 to 2015. I argue that protest t-shirts are a form of discursive activism that function as mediums for contestation, exchange, and memory making. In the first two chapters of the dissertation I conduct a visual material history of t-shirts and iconic images from the Black Power Movement. In the final two chapters, I focus on the specific ways both men and women have been iconized as victims of state sanctioned violence in the current Black Lives Matter movement. To conclude the project, I discuss what protest t-shirt culture can tell us about diasporic communication regarding global struggles and the points of differentiation between varied Black experiences. By looking at protest t-shirt culture as a political practice, my project illustrates how black political participation has shifted from leader-centered to group-centered models of organizing. It also sheds light on historical gaps in the archive, especially in relation to representations of marginalized members of the black community./nMy research has involved analyzing how protest t-shirts circulate through private collections and grassroots organizations, online retailers of user-customized products, and public culture. It has also necessitated personal interviews with activists and family members, academics, research think tanks, and grassroots organizations. The majority of these interviews are dedicated to specific printing companies that work exclusively with grassroots organizations focusing on fair housing, immigration rights, and the criminalization of communities of color, to explore how the t-shirt trade can also serve as fundraising platforms that support activist campaigns. I also investigate African Americans’ move from being seen as mere consumers of social media to being recognized as social actors at the forefront of both movement organizing and entrepreneurial endeavors. The incorporation of social networking analysis further documents the history, popularity, and use of the black protest t-shirt genre during the civil rights and black power generation and for today’s hip hop and millennial generations.

Advisor: Catanese, Brandi W.
Photodissociation Studies of Combustion Relevant Radical Molecules

The photodissociation of several combustion relevant radical molecules has been carried out. These species behave significantly different from closed shell species and the experiments presented here provide fundamental new insights into the chemical dynamics of free radicals./nThe experiments were carried out on a molecular beam photofragment translational spectroscopy instrument. Radicals were generated by flash pyrolysis of a suitable precursor and entrained in a pulsed molecular beam. The radicals were then photodissociated and the products were detected with a rotatable mass spectrometer based on electron impact ionization./nThe benzyl radical photodissociation and the cyclopentadienyl radical photodissociation were investigated at 248 nm. Two dissociation channels were observed for each radical. The benzyl radical dissociates into H + C7H6 and CH3 + C6H4 and the cyclopentadienyl radical dissociates to H + C5H4 and C3H3 + C2H2, where the C5H4 fragment was identified as ethynylallene by its ionization energy./nThe translational energy distribution determined for each channel suggests that every dissociation mechanism occurs via internal conversion to the ground state followed by intramolecular vibrational redistribution and dissociation. The branching ratio between the two competing channels for each radical was measured experimentally and compared to RRKM (Rice-Ramspberger-Kassel-Marcus) calculations. For both radicals, the dominant experimental channel was corroborated by RRKM calculations.

Advisor: Neumark, Daniel M
New Techniques for Continuous Optimization and Fast Algorithms for Flow

Spielman and Teng's nearly linear time algorithm for solving Laplacian systems was a breakthrough in combining techniques from discrete and continuous optimization. In this dissertation we adapt their approach to solve more general flow problems, overcoming long-standing barriers in continuous optimization. As a result we solve longstanding open questions in optimization by presenting nearly-linear time approximation algorithms for the undirected versions of several network flow problems, including \emph{maximum flow}, \emph{optimal transportation}, \emph{maximum concurrent multi-commodity flow}, and \emph{sparsest cut} problems./nOur contributions include two general tools. The first is a scheme for boosting the performance of iterative solvers for continuous optimization problems. These boosters use recursive composition to achieve residual error that decreases exponentially in the number of iterations of the solver./nThe second is a technique for designing iterative solvers that bypasses the infamous $\ell_{\infty}$ barrier for strongly convex regularization. Instead we introduce the notion of an area convex regularizer, and show that such regularizers suffice in designing good iterative solvers. Moreover, we show how to design regularizers satisfying this weaker property for the problem of approximately solving $A X \leq B$ over right stochastic $X$, which in turn implies the algorithm for maximum concurrent multi-commodity flow.

Advisor: Vazirani, Umesh
Development and Application of Genome Editing Approaches to Investigate Endogenous Retroviruses

Endogenous retroviruses (ERVs) constitute a significant fraction of mammalian genomes, but their impact on host biology remains poorly understood. One group of ERVs, murine ERV with leucine tRNA primer (MERVL), is highly expressed during the 2-cell (2C) stage of mouse preimplantation development but is silenced thereafter. While active, MERVL-derived cis-regulatory elements drive expression of hundreds of host genes, including “chimeric” isoforms with exonized MERVL sequences. Remarkably, loss of a single miRNA miR-34a in pluripotent stem cells is sufficient to derepress MERVL and imbue expanded fate potential reminiscent of totipotent 2C blastomeres. Using bioinformatic prediction and reporter assays, I identified gata2 as the primary target of miR-34a that mediates MERVL derepression in pluripotent stem cells. While miR-34a is required for MERVL silencing in pluripotent stem cells, it is dispensable for repressing MERVL during preimplantation development. To evaluate the role of MERVL in vivo, I applied a candidate approach to assess the role of one MERVL-driven chimeric gene tead4:MT2B1. Loss of tead4:MT2B1 results in compensatory upregulation of canonical tead4 transcripts, suggesting that the chimeric isoform functions redundantly in development. In order to facilitate efficient in vivo screening of additional candidates, I developed a high-throughput electroporation-based genome editing technique called CRISPR RNP Electroporation of Zygotes (CRISR-EZ). Compared to previous methodologies, CRISPR-EZ offers significant advantages in throughput, cost, and simplicity. Altogether, I have elucidated a molecular axis involved in the regulation of MERVL and fate potency, setting the stage for further in vivo characterization using improved genome editing tools.

Advisor: He, Lin
Data-efficient Analytics for Optimal Human-Cyber-Physical Systems

The goal of this research is to enable optimal human-cyber-physical systems (h-CPS) by data-efficient analytics. The capacities of societal-scale infrastructures such as smart buildings and power grids are rapidly increasing, becoming physical systems capable of cyber computation that can deliver human-centric services while enhancing efficiency and resilience. Because people are central to h-CPS, the first part of this thesis is dedicated to learning about the human factors, including both human behaviors and preferences. To address the central challenge of data scarcity, we propose physics-inspired sensing by proxy and a framework of "weak supervision" to leverage high-level heuristics from domain knowledge. To infer human preferences, our key insight is to learn a functional abstraction that can rationalize people's behaviors. Drawing on this insight, we develop an inverse game theory framework that determines people's utility functions by observing how they interact with one another in a social game to conserve energy. We further propose deep Bayesian inverse reinforcement learning, which simultaneously learns a motivator representation to expand the capacity of modeling complex rewards and rationalizes an agent's sequence of actions to infer its long-term goals./nEnabled by this contextual awareness of the human, cyber, and physical states, we introduce methods to analyze and enhance system-level efficiency and resilience. We propose an energy retail model that enables distributed energy resource utilization and that exploits demand-side flexibility. The synergy that naturally emerges from integrated optimization of thermal and electrical energy provision substantially improves efficiency and economy. While data empowers the aforementioned h-CPS learning and control, malicious attacks can pose major security threats. The cyber resilience of power system state estimation is analyzed. The envisioning process naturally leads to a power grid resilience metric to guide "grid hardening." While the methods introduced in the thesis can be applied to many h-CPS systems, this thesis focuses primarily on the implications for smart buildings and smart grid.

Advisor: Spanos, Costas
Polyketide Synthase Engineering via Catalytic Domain Exchanges

Polyketides comprise a structurally diverse class of natural products that includes many highly effective pharmaceuticals. As such, the development of techniques to produce polyketide analogs with potentially improved pharmacokinetic or toxicological properties is a research area of great interest. The modular nature of PKSs has also motivated researchers to explore methods of employing engineered PKSs for the biological synthesis of industrially relevant small molecules, in addition to natural product drugs./nWe utilize in vitro enzyme studies to elucidate the biosynthetic potential of polyketide synthases (PKSs), the large, multisubunit enzymes responsible for polyketide production, and further leverage the insights gained from benchtop experiments to inform alterations to culture conditions that enable the production of non-natural natural product analogs./nIn addition, we report progress developing methods to harness our understanding of the modular structure of PKSs to reliably exchange ketoreductase (KR) domains between PKS systems. The importance of stereochemistry in determining biological activity makes an ability to understand and engineer KR domains, which dictate the stereochemistry at many of the stereocenters in polyketide products, essential to the objective of effectively exploiting PKSs for combinatorial biosynthesis. Our work to identify heuristics that facilitate reliable KR domain exchanges furnished a novel library of PKS variants harboring different KR domains, further enabling studies that provide insight into how KR domains function in the context of a PKS module./nFinally, we build on the knowledge gleaned from KR domain exchange experiments to develop more general strategies for PKS engineering. A limited theoretical understanding of the determinants of PKS fold and function poses a substantial barrier to the design of active variants, and identifying strategies to reliably construct functional PKS chimeras remains an active area of research. We develop and formalize a paradigm for the design of PKS chimeras, and implement a computational platform to streamline and simplify the process of designing experiments to test strategies for PKS engineering. Finally, we discuss the implications of this system for enabling the effective use of PKSs in synthetic biology applications.

Advisor: Keasling, Jay D
Exegetical Theory and Textual Communities in Late Anglo-Saxon England

This dissertation, a study in political hermeneutics, claims the practice of biblical interpretation as one of the primary shaping forces of Anglo-Saxon literature and society. From the educational reforms of King Alfred (r. 871-99) through the end of the Anglo-Saxon kingdom (c. 1066), anyone who received an education in England began by memorizing the Psalms and progressed to the study of biblical exegesis, a method of reading that moves from the historical analysis of scripture to the figurative description of moral action in the present and eternal punishment or reward in the future. Exegetical theory inscribes human action in the morally charged temporalities of Christian salvation history, encompassing all historical time from Creation to Judgment Day. It provides a foundational method by which Anglo-Saxons read texts, but it also becomes a powerful structuring principle of sacred and secular society as a whole. The practice of scriptural interpretation interpellates individual subjects as historical actors, and it frames social institutions, from monasteries to the kingdom itself, as agents in the unfolding progress of world history. The chapters that follow study its role in the Alfredian translations, Ælfrician liturgy, hermeneutic Latin diplomas, and classical verse of the Anglo-Saxon Chronicle. Although land conveyances and the heroic Battle of Brunanburh might be the last places we would expect to find the effect of exegetical reading, I show that it is precisely such texts where exegetical theory makes its influence known most effectively. These texts frame real politics and warfare as moments in the progress of salvation history, and they place contemporary individuals at the center of the action. In late Anglo-Saxon England, salvation history provides the absolute and universal horizon of present action, subsuming the lives of individuals and the developing history of the kingdom. At the same time, individual writers saw this horizon approaching at different rates, and no two writers perceived the shape of its curve in quite the same way. My dissertation reveals how the exegetical interpretation of texts and events produces the Anglo-Saxon political subject as an actor in salvation history, one who is shaped by it at the same time that he or she works to further its progress.

Advisor: O'Brien O'Keeffe, Katherine
Mapping Input-Response Function of Early T Activation

Cells integrate signals from environmental inputs to regulate cellular programming, such as protein production, differentiation, and proliferation. This cellular decision making process occurs across multiple time and length scales, during which a cascade of biochemical reactions transduces signal from inputs to a functional outcome. T cells are a prototypical example of cells that make activation decisions based on discriminating a low level of agonist ligands, which is a peptide fragment presented on Major Histocompatibility Complex (pMHC). In recent years it has become evident that only a handful of ligands are sufficient to activate T cells to secrete cytokines or cytotoxic granules. In this low density pMHC regime, the sequence of T cell receptor (TCR) binding events that a T cell collects is highly stochastic, and the physical mechanism of input integration that overcomes the noise and accurately translates the signal remains unknown./nThis work investigates the molecular processes underlying how T cell input integration results in a cellular activation outcome. First, an imaging assay based on a live cell-supported membrane platform is introduced to directly observe the sequence of single molecule pMHC:TCR bindings (inputs) and the presence of ligand:receptor:kinase complexes. Titrations of pMHC densities are performed to study the effect of initial binding events on subsequent binding events. Similar measurements were extended to auto-reactive human T cells to compare their binding affinities to normal human T cells. We further map the sequence of pMHC:TCR binding events to early T cell activation, as read out by the translocation of the transcription factor NFAT. Results from the input-outcome assay indicates that T cells may coordinate input accumulation. We then investigate protein assemblies as a potential mechanism of coordinated input accumulation. This work highlights the common feature of spatiotemporally coordinated input accumulation as a general design principle in cellular decision making.

Advisor: Groves, Jay
Greek Afterlives in Early Modern England: Fiction, Scholarship, and Postclassical Hellenism

This dissertation offers a new account of sixteenth- and early seventeenth-century fiction-making through a reevaluation of early modern Hellenism. I demonstrate that the reconstruction of ancient Greek culture functioned as an origin point for the emergence of both modern scholarship and modern fiction, merging scholarly speculation with imaginative world-creation. Through the processes of speculative and imaginative reconstruction, early modern authors and scholars found in the self-conscious belatedness of Greek postclassicism (Hellenistic and Second Sophistic Greek literature produced after the “golden age” of classical Athens) a provocative reflection of their own attempts to revive a distant classical past. Postclassical Greek authors thus acted as mediators of early Greek antiquity, modeling through their own hybridized fictions literary strategies for “coming after.” By proposing a historically palimpsestic model for reception, my dissertation reorients our understanding of early modern cultural recovery away from a discourse of melancholic loss towards one of empowered belatedness./nIn uncovering the neglected influence of this postclassical Greek corpus, my dissertation offers an interdisciplinary archaeology of fiction that connects manifestly innovative works of early modern literature that have often defied attempts at classification – Thomas More’s Utopia, François Rabelais’ Gargantua, Christopher Marlowe’s Hero and Leander, and William Shakespeare’s Troilus and Cressida – to early modern discourses of pedagogy, philosophy, politics, and geography. The works of imaginative literature I examine negotiate “Greekness” as a transnational and transtemporal cultural palimpsest, one informed by the mobile and decentered Hellenism that characterized the expansive imperial reach of the postclassical and Byzantine Greek worlds. I show how the contemporary geo-cultural boundaries of the Byzantine and Ottoman empires inflected early modern perceptions of Greek identity. By situating early modern Hellenism within networks of print culture and by attending to the transmission of material texts, my project places English early modernity within a larger transnational intellectual community.

Advisor: Kahn, Victoria
Picciotto, Joanna