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Getting Back to Normal After Extreme Weather: Houston-Area Residents’ Recovery Following Hurricane Beryl and Other Major Storms of 2024
No full textThis study examines the recovery of Houston-area residents following Hurricane Beryl as well as additional aspects of recovery, such as financial stressors, they experienced as a result of severe weather events in 2024 collectively. Recovery—defined as a resident’s self-reported return to normal daily life—is examined in the short term (i.e., about 2-4 weeks after Hurricane Beryl) and longer term (i.e., about 4-6 months after the hurricane). The study examines how individual and household characteristics affect a person’s ability to recover, while accounting for the impacts of the storm. Additional stressors related to recovery are also described, such as concerns with being able to pay for the costs of recovery and those associated with preparing for the next natural disaster
Catalytic Hydrogen Atom Transfer Enabled by Earth-Abundant Metals and Thiols
No full textHydrogen atom transfer (HAT) as a reaction class has been instrumental in enabling organic radical intermediates within synthetic method design, due to the high chemoselectivity and radical mechanism. Many such radical transformations utilize earth abundant catalysts, improving upon classic methods often catalyzed by unsustainable and expensive precious metals. By better understanding the mechanisms of HAT reactions, useful synthetic transformations can be improved and rationally designed through control of the catalytic cycles and intermediates.
Chapter 1 describes the mechanistic exploration of our previously published cooperative hydrogen atom transfer (cHAT), a chemoselective hydrogenation of unactivated olefins dually catalyzed by iron and thiol. Through kinetic studies, spectroscopic work, and computations, we propose an updated mechanism including iron(II)/thiol binding and PCET delivery of the second hydrogen atom. We suggest formation of the iron-hydride as the turnover limiting step and observed an iron/thiol catalyst deactivation pathway. Such mechanistic studies advance our understanding of iron-catalyzed metal HAT (mHAT) reactions and provide a strong foundation for additional reaction development.
Chapter 2 utilizes the mechanistic insights of Chapter 1 to develop an enantioselective cHAT reaction via the incorporation of a chiral thiol catalyst, the first observation of appreciable enantioinduction by iron catalyzed mHAT. We observe up to 80:20 enantiomeric ratio (er) in a substrate scope of thiazolidines and cyclic ureas and suggest the degree of enantioinduction to be substrate-dependent and sterically driven. The observed compatibility of chiral thiols with iron catalysts is an exciting opportunity for novel asymmetric iron-catalyzed mHAT reactions.
Chapter 3 details the beginnings of future work to improve the enantioselective cHAT reaction through further focus on chiral thiols. Additional chiral thiol scaffolds are screened, and allyl alcohol substrates as iron directing groups are considered to utilize the proposed iron/thiol binding for enhanced selectivity. Finally, electron-deficient olefins are proposed as substrates to make use of hydrogen bonding interactions with chiral peptidyl thiols.
Chapter 4 explores method development for a tunable oxetane ring opening via photocatalysis, enabled by visible light and sustainable cobalt catalyst Vitamin B12. Through mechanistic control and careful choice of additives, we are able to select for either the hydrogenative ring opened alcohols, or reductively isomerized allylic alcohols. Mechanistic studies support the alternate radical and polar steps, and substrate scope exploration demonstrates good functional group tolerance with steric sensitivity.
Overall, this thesis explores reaction development and mechanistic studies for earth-abundant (photo)catalysis by metals and thiols. Better understanding of radical HAT steps enables rational reaction design and control, laying the groundwork for future sustainable catalysis driven by the next generation of chemists
5.1 Biotechnology for a Sustainable & Equitable Global Bioeconomy
No full textThis entreaty was created as part of The Spirit of Asilomar and the Future of Biotechnology summit (February 23-26, 2025) in Pacific Grove, CA.Biotechnology is key to a sustainable, equitable global future. This entreaty calls for international cooperation, inclusive capacity-building, responsible governance, and resilient financing to unlock its full potential. By valuing biodiversity, aligning global standards, and promoting ethical innovation, biotechnology can foster shared prosperity, environmental stewardship, and long-term economic resilience across all regions
Essays on Household Energy Transition, Policy, and Welfare
No full textThis dissertation explores household energy choices and the economic and policy determinants shaping them across different contexts. The first chapter examines the effects of natural gas restrictions on heat pump adoption in California, constructing a structural model to evaluate consumer energy use, welfare impacts, and policy interventions aimed at mitigating financial burdens. The findings highlight the trade-offs between efficiency gains and electricity price-driven welfare losses. The second chapter investigates income disparities in heat pump adoption across the U.S., analyzing the distributional effects of financial incentives and how energy costs, household demographics, and policy design influence electrification. The results reveal that financial constraints remain a key barrier, limiting equitable adoption among low-income households. The third chapter shifts focus to China, studying the impact of urbanization and infrastructure expansion on the transition to cleaner cooking fuels. Using a structural model, the study quantifies how migration, natural gas pricing policies, and energy infrastructure development affect fuel choices and household welfare. Together, these essays contribute to the broader understanding of household energy transitions, providing insights into the effectiveness of policy interventions in advancing decarbonization and energy equity
Degeneration of flat metrics from k–differentials
No full textThis thesis explores the space of flat metrics sitting in the space of geodesic cur- rents. The space of geodesic currents, considered as the completion of weighted closed curves, was first introduced by Bonahon to study hyperbolic 3–manifolds, and then used by him to provide an alternative description of Thurston’s compactifica- tion of Teichmu ̈ller space. This space has since played a key role in the study of geometric structures on surfaces and their degenerations. We focus on the space of flat metrics from k–differentials on finite–type surfaces and its embedding into the space of geodesic currents. With this embedding, we describe a compactification of the space of flat metrics coming from k–differentials, for all k, where the boundary points are the mixed structures—currents that are a flat metric on a subsurface and a measured lamination on the complement. This generalizes the results of Duchin– Leininger–Rafi for the case when k = 2 and Ouyang–Tamburelli for the case when k = 3, 4
Girls’ and Boys’ Health Lifestyles from Childhood to Adolescence
No full textHealth behaviors are critical contributors to disease and death in individuals and shape health disparities in populations. According to a health lifestyle perspective, health behaviors are organized in meaningful patterns reflecting wider social structures. Previous work has shown that health lifestyles are important for both social identity and health among adolescents and adults. Yet, children's health lifestyles are conceptually distinct from adult health lifestyles, and less is known about how health lifestyles develop earlier in life. To address this gap, I utilize data from The Future of Families and Child Wellbeing Study (FFCWS), to identify empirical patterns of health behaviors that reflect health lifestyles, and how these health lifestyles change across childhood to adolescence. Results indicate that health lifestyle development is partially path dependent. Sometimes this reflects social status, as family socioeconomic background shapes early health lifestyles which influence later lifestyles, while gender only emerges as a salient factor in adolescence. I also investigate the implications of health lifestyles on emerging risky health behaviors and health. While there is some evidence that childhood health lifestyles are associated with emerging adolescent risky behaviors, the relationship varies by the behavior and gender. Overall, children with a mostly unfavorable, but more outdoor play health lifestyle have higher odds of using marijuana in adolescence than other lifestyles. The mostly unfavorable childhood health lifestyle also shows higher probability of ever cigarette smoking, drinking alcohol, and having sexual intercourse– but only for girls. While childhood lifestyles with greater outdoor play do not translate into higher ratings of adolescent self-rated health (SRH), adolescent lifestyles differentiated by levels of physical activity do display significant differences in SRH. The relationship between adolescent health lifestyles and SRH is also inconsistent across gender. For instance, teenage boys engaging in a lifestyle comprised of mostly unhealthy behaviors still rate their health higher than girls engaging in a lifestyle comprised of the healthiest behaviors. Yet, health lifestyles do not fully explain the female excess in poorer self-rated health. Overall, these findings support a weaking in socioeconomic disparities and strengthening of gender disparities in health lifestyles and their implications from childhood to adolescence
The Cost of Caring: Living Bereavement, Socioeconomic Status and Inflammation amongst Dementia Spousal Caregivers
No full textDementia caregiving is one of the daunting experiences mostly associated with anticipatory grief and sometimes dire health outcomes. The present study investigated relationships between anticipatory grief, socioeconomic status (SES), and inflammation among spousal caregivers of individuals with dementia. The study hypothesized that higher levels of anticipatory grief would be associated with increased inflammation and that lower SES would correlate with both higher anticipatory grief and inflammation levels.
The sample for the present study was drawn from a larger longitudinal study examining risk and resilience mechanisms underlying differences in physical health risks among dementia spousal caregivers. A total of one hundred sixty-one dementia spousal caregivers completed blood draws and self-report questionnaires for this study. To be eligible, participants had to (1) self-identify as the main person taking care of their spouse with dementia, (2) provide care for their spouse a minimum of four hours a day for at least the last three months, and (3) the dementia spousal caregiver and the patient must have been married (or self-defined as long-term committed partners) for at least three years prior to participation. Those who participated in the main study were predominately female (76%), over 65, and highly educated. Correlation and regression analyses were conducted to examine the relationships between variables.
According to the results of the study, there was a positive correlation between anticipatory grief and inflammation (r = 0.137, p = 0.081), albeit insignificant. Several SES indicators, including subjective SES (r = -0.234, p < 0.01) and family income (r = -0.178, p < 0.01), were significantly negatively correlated with anticipatory grief. Family income was the only SES indicator significantly correlated with inflammation (r = -0.161, p < 0.05). According to the regression result, anticipatory grief, education, and family income are significant predictors of inflammation levels, accounting for 5.7% of the variance.
According to the result of the present study, caregivers with dementia may experience a complicated interaction between anticipatory grieving, socioeconomic status, and inflammation. The relevance of examining socioeconomic determinants in caregiver health is shown by the substantial correlations between SES markers, notably family income and education, as well as both inflammation and sadness, even though the link between the two was not as strong as expected. To further understand this population's inflammation and develop focused treatments and support systems for dementia caregivers, future studies should investigate other potential variables
Essays on Industrial Organization and Quantitative Marketing
Get PDFIn Chapter 1, I develop a structural model where strategic buyers choose purchase timings under price dynamics and stockout risk, whereas sellers optimize initial inventory size. To estimate the model parameters, I use granular data on a wholesale flower market. In a counterfactual analysis, I simulate market outcomes under uniform pricing and perform a welfare analysis. The counterfactual results indicate that sellers would raise the initial inventory size and set lower prices under uniform pricing. In terms of welfare, uniform pricing would benefit sellers relative to uniform pricing, especially when they can optimally choose initial inventory size. In contrast, uniform pricing would hurt buyers relative to dynamic pricing.
In Chapter 2 (with Yunmi Kong), we document the impact of a simple but universally applicable auction innovation: moving online. We leverage bid-level data from an offline to online transition of state mineral lease auctions, the features of which facilitate a detailed study. Controlling for auction heterogeneity, we find a large revenue difference in favor of online auctions, explained by a large increase in the number of bidders. Bidders' identities reveal an inflow of new participants who had not participated before the transition. We do not detect different post-auction outcomes between new and existing participants. Where not yet adopted, online auctions are well worth trying.
In Chapter 3 (with Suguru Otani), we investigate products sold before consumption and examine how the duration of the consumption periods and the choice of selling mechanism influence sellers' revenue. Using empirical data from timber auctions, we identify buyers' tendency to delay consumption to resolve payoff uncertainty and reveal heterogeneous motivations among buyers. Through structural estimation, we uncover key parameters for each buyer type, including sensitivity to realized payoffs and consumption-related costs. Leveraging these estimates, we perform counterfactual analyses to propose revenue-enhancing consumption periods and selling mechanisms. Our findings suggest that extending the consumption periods is likely to increase revenue, with the magnitude depending on the selling mechanism, the composition of buyer types, and the number of interested buyers
Ground-State Squeezing and Chiral Photonic Crystal Cavities in Ultrastrong Light-Matter Coupling
No full textThis thesis investigates quantum light–matter interactions in photonic-crystal cavities, focusing on two complementary projects. The first project develops a theoretical framework for Landau polaritons in terahertz cavities by computing ground-state current-current correlations in a two-dimensional electron gas under ultrastrong coupling (USC). We show that these correlations reveal an intrinsically squeezed ground state—an effect absent in conventional linear spectroscopy. The second project designs, fabricates, and characterizes a one-dimensional chiral photonic-crystal cavity that breaks time-reversal symmetry. The cavity consists of a silicon layer sandwiched between lightly doped indium antimonide (InSb) wafers, exploiting InSb’s low carrier mass and magnetoplasma nonreciprocity to support a single circularly polarized mode at 0.67 THz under a 0.3 T magnetic field, achieving a quality factor above 200. Systematic experiments—varying temperature, magnetic field, and polarization—together with simulations, confirm the cavity’s nonreciprocal behavior and robust mode confinement. Altogether, these studies deepen our understanding of USC-induced quantum effects in photonic cavities and introduce a versatile platform that enables precise manipulation of material properties by breaking key symmetries
Emergence of Ramping Activity in Random Spiking Networks: A Biologically Plausible Model for Learning Timing
No full textThe ability to perceive and learn timing is crucial for animals to interact with the world. Experiments have shown that during motor planning, certain neurons in multiple brain regions exhibit slow ramping activity that gradually increases until an action begins. This ramping activity is believed to be the neural basis of timing. However, the mechanisms by which these ramping activities emerge from network dynamics and how they are learned through reinforcement learning remain poorly understood. We propose a spiking neural network model and a biologically realistic learning rule to learn this ramping behavior that can last on the order of seconds. Our model consists of a randomly connected recurrent neural network (RNN) that integrates input from a decision-making network. Synaptic connections are trained using an eligibility trace-based learning rule. Using mean-field theory, we analyze the RNN to determine the conditions necessary for it to function effectively as an integrator. This model qualitatively reproduces the ramping patterns observed in mouse brains during decision-making tasks at the single-neuron and population levels. Furthermore, an extended version of our model accounts for additional experimental findings in mouse decision-making tasks