Good, Bad, or Indifferent: Effects of Brain Stimulation for Those Affected by Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurological disorder that affects the social and behavioral abilities of those who are impacted by it. Because the disorder is not specific in who it affects (due to genetic and environmental factors), it is not easy to pinpoint the cause to apply a solution across the board. Which symptoms are displayed, and the severity in which they are experienced is a roll of the dice. From the time the term autism was first documented to have been spoken, consistent change is all we have known. Today, individuals who are on the spectrum have access to a more inclusive and accommodating experience when compared to historical accounts of those with ASD-like impairments. Person-specific treatment plans and targeted therapies are available to increase quality of life while also managing the symptoms of ASD. While traditional methods such as treatment programs, medication, and the like have given this population relief, I think it is time for us to push the boundaries for our impaired brethren and sistren. Various forms of brain stimulation, as well as electroconvulsive therapy, currently provide alternative treatment measures that may be able to offer more than momentary relief for the individual as well as the caretaker. While the methodology was misused as a weapon in the past, I say we reclaim this restorative tool and look to give this population some life back to their years. By introducing case studies and other works, we will see how this tool can be utilized for the good of the ASD community.Extension Studie

A Quantum Memory Network Based on Diamond Nanophotonics

Quantum networks hold the potential to enable quantum-secured communication, distributed quantum computing, and non-local quantum sensing. To realize these applications, a versatile quantum network infrastructure must support entanglement between network nodes capable of storing, processing, and distributing quantum information, alongside high-fidelity photonic qubits that efficiently interface with these nodes. The silicon-vacancy (SiV) center in diamond, coupled to nanophotonic cavities, has recently emerged as a promising platform to meet these requirements. This system provides access to an electron spin as an optically active communication qubit and a 29Si nuclear spin as a memory qubit, capable of storing quantum information for extended periods. We first demonstrate that the SiV center's electron spin can efficiently generate single photons with complex spatiotemporal waveforms, facilitated by a novel asymmetric nanophotonic cavity design. We then establish a two-node quantum network between two SiV centers housed in separate laboratories and connected via optical fiber. To do so, we use photonic qubits to mediate entanglement between two spatially separated electron spins, as well as between two spatially separated nuclear spins. Finally, using bidirectional quantum frequency conversion, we convert the photonic qubits to telecommunication frequencies, enabling entanglement generation between the two nuclear spins via a 35 km fiber deployed in the Boston metropolitan area. These advancements mark progress toward large-scale, deployable quantum networks using SiV centers coupled to nanophotonic cavities.Physic

Job Loss and Work Among Older Workers

In recent decades the older worker population has grown significantly, and its sociodemographic composition has become more diverse. Yet it is not clear what the implications of these demographic changes are for work in older age. Prior research on aging and work has predominately studied more advantaged workers. This dissertation improves our understanding of the labor market experiences of marginalized workers in older age. In Chapter 2, I evaluate whether Black-White disparities in reemployment likelihood increase, decrease, or remain constant among older workers relative to younger workers and what factors explain these differences. I draw on scholarship on racial disparities in health and evaluate three hypotheses: cumulative dis/advantage (inequality increases over time), aging-as- leveler (inequality decreases over time), and persistent inequality (inequality does not change over time). I test these hypotheses using hazard models and data from the Survey of Income and Program Participation. I find that Black-White inequalities in reemployment narrow by about 70 percent in older age, supporting the aging-as-leveler perspective. Relative to their younger counterparts, White older workers experience a greater decline in reemployment likelihood than Black older workers. Though Black older workers face the lowest chance of reemployment. Prior experience, education, and skills do not explain Black-White differences in reemployment across age, suggesting that hiring discrimination and other post-job-loss factors likely underlie these differences. In Chapter 3, I generate more comprehensive estimates of Black-White differences in the costs of job loss across age and test which theories account for these differences. Scholarship on job loss typically examines changes in earnings only for workers who reemploy and likely underestimates the financial implications of late-career job loss, particularly for minority older workers. In my sample I include individuals who do not reemploy to account for Black and older workers’ lower likelihood of reemployment. Using fixed effects models and data from the Survey of Income and Program Participation, I find that workers experience a large decline in earnings following job loss, ranging from 65 to 81 percent 1-3 years after job loss. Older and Black workers experience greater declines in earnings than their White and younger counterparts, but I do not find evidence of Black-White disparities changing across age. I find that job tenure partially accounts for age differences, pointing to human capital, job matching, and deferred compensation theories. However, age and race differences in earnings losses remain either partially or totally unexplained, suggesting that differences stem from unobserved factors that likely emerge after job loss, such as job search characteristics and age and racial discrimination. In Chapter 4, I examine why less-educated men are more likely to exit the labor force than their more-educated counterparts prior to retirement age. In recent decades there has been an increase in early retirement (labor force exit by around age 60) among men, particularly among those without a college degree. This gap in labor force attachment by educational attainment (what I refer to as the education gap) is of concern because working into older age is critical for creating a sufficient nest egg for retirement. Is the education gap in labor force participation due to choice or constraint? I use the Health and Retirement Study to estimate how much of the education gap is a function of less-educated men disproportionately being unable to work (health status) and disproportionately lacking access to higher-quality jobs with employee retirement benefits that encourage working longer (pensions). I find that differences in health status and in pension coverage account for 67 percent and 22 percent of the gap, respectively. Together these findings suggest that less-educated men likely exit the labor force due to constraint, prior to saving enough for retirement. The education gap in labor force participation could therefore be a precursor to retirement security inequalities in older age.Social Polic

Frame to Foreground: Translating Documentary Landscapes in Braddock, PA

The project posits that critical photography should be adopted as a design methodology – starting from the representation of a diagnostic relationship between a subject and their setting to grasp at the ineffable affect that artists capture beautifully, and often revealing social issues, left in tension within the frame through photographic techniques. This thesis project argues the translation of critical photography into spatial elements is crucial for our understanding of place. Furthermore, this new methodology reveals the concept of defining landscape as a set of relationships between living beings. The project is about preserving what every local in Braddock, Pennsylvania holds—a strong relationship to place. Using Frazier’s framing techniques, this thesis injects photography directly into the method of design. The project imagines a system of public landscapes that are centered in belonging, gathering, and reclaiming space. A riverfront park, a gathering pavilion, a public plaza, and a garden work as one to knit together a post-industrial steel mill town that has been disinvested for forty years. This thesis is advised by Sara Zewde.Department of Landscape Architectur

The Peso Perspective: Understanding Risk and Return in Global Currency Markets

The drivers of currency excess returns remain poorly understood despite the foreign exchange market’s size and liquidity. Using five measures of risk — novel text-based measures (from newspaper articles and firm earnings calls) alongside traditional risk indices that capture a country’s economic, financial, and political risk — I show that financial risk is the dominant predictor of volatility in emerging market currency returns, while geopolitical risk is positively associated with excess returns, supporting a risk premium explanation for the profitability of currency trades. Firm-level risk perceptions, especially from foreign firms, outperform political/economic risk in forecasting returns. However, country-specific risks explain only a fraction of exchange rate movements, revealing fundamental limits to forecasting exchange rate movements. The results highlight financial stability as a stronger determinant of risk premia than political uncertainty, with implications for currency speculators and policy-making in emerging economies.Applied Mathematic

Long-Term Single-Cell Imaging of Live Microbes by Correlative Fluorescence and Raman Microscopy & Time-Resolved Stark Effect Spectroscopy of Protein Crystals

Understanding the behavior of a microbe requires not only an understanding of molecular mechanisms, e.g. DNA replication, transcription, and translation, but also knowledge of the cell’s chemical composition over time. There are powerful tools for probing the mechanisms of core cell-biological processes. However, the existing tools to measure cell composition have significant limitations. Information-rich methods, such as mass spectrometry, are lethal, while fluorescence methods provide good time resolution and work on live cells, but are limited in what they can measure. Prior work has demonstrated that spontaneous Raman spectroscopy can be a powerful tool to measure cellular composition. However, low throughput has limited its potential for discovery. Here, I describe my contributions to correlated epifluorescence and laser scanning Raman microscopy to enable the collection of single-cell spectra from many single cells in long-term time-lapse experiments, with imaging every 15 minutes. I then establish that this single-cell Raman imaging (scRaman) system can be used without substantial phototoxic effects to image the yeast Saccharomyces cerevisiae. To benchmark the ability to track biologically important changes in cellular composition, I study S. cerevisiae under conditions of nitrogen starvation and repletion. I demonstrate the ability of this system to resolve the dynamics of compositional changes at a single-cell level, mapping the observed dynamics to known biological mechanisms. I describe the analysis pipeline required for this work and the advances in combined Raman and microscope control software to achieve these experiments. Finally, I describe a separate project in which I developed an analytical framework for interpreting time-resolved Stark effect spectroscopy data obtained from single protein crystals.Engineering and Applied Sciences - Applied Physic

Logistics in the Line of Fire: A Stochastic Programming Model for Contested Environments

As military doctrine evolves to address the challenges of large-scale combat operations (LSCO), logistics planning must adapt to ensure the continuous sustainment of dispersed and contested forces. This thesis presents a two-stage stochastic mixed-integer programming (MIP) model designed to optimize military resupply under uncertainty. The formulation incorporates key doctrinal priorities, such as predictive logistics, prepositioned supply, and distribution network resilience, by explicitly modeling disruptions to supply routes and storage nodes. Using scenario data created from the Russo-Ukrainian War, the model evaluates the impact of adversarial attacks, storage costs, and vehicle availability on overall logistical performance. The results provide quantitative insight into the tradeoffs between transportation and storage-based supply strategies, revealing nonlinear thresholds that influence the model's behavior. The proposed framework offers a rigorous, extensible tool for analyzing logistics strategies in adversarial environments and contributes to the broader effort to formalize military logistics planning using mathematical modeling and data-driven decision making.Applied Mathematic

Evaluating Migration of Human Monocytes in an Inflammatory Environment Mimicking Burn-Induced Inflammation in Blood Donor Samples

In the U.S., more than half a million people are hospitalized for burn wounds every year. These wounds can progress into serious and even fatal injuries due to the immune system’s defense against harmful pathogens with access to bodily tissues through the burn injury. This invasion into bodily tissue can lead to systemic inflammation. One of the by-products of this inflammation is the activation and migration of white blood cells, specifically monocytes, to the site of injury and/or infection to eliminate the microbes and protect the surrounding tissues. While relatively small, inactive monocytes can drastically increase their size in the case of activation via pathogenic infection. Although the general mechanisms are understood, there are significant components of monocyte activity that have not been clearly elucidated. However, it has been shown that these monocytes boast significant prognostic capabilities. The severity and potential outcome of patient injuries can be predicted with considerable accuracy using Monocyte Distribution Width (MDW), or monocyte anisocytosis, which is the difference in monocyte sizes within an individual. In this research, we investigate the activity and size distribution of monocytes under various conditions. It was found that, as expected, the trigger protein (SDF-1α) induced monocyte migration dependent on the concentration used. However, the inhibitor (AMD-3100) markedly reduced migration when used in conjunction with SDF-1α. Also, the activators lipopolysaccharide (LPS) and Pam3CysSerLys4 (PAM) were shown to increase MDW.Extension Studie

Zealots of Justice: Coercive Officials in Late Medieval Italy

This dissertation considers how, between about 1200 and 1350, cities in the upper half of the Italian peninsula experimented with a new kind of official whose primary task was coercion. There is a rich scholarship on institutions of public justice in the self-governing “communes” of thirteenth- and fourteenth-century Italy, but little of it has engaged with the coercive apparatus that served the courts and their users. It was easily the most sophisticated in Europe since the fall of the western Roman Empire. Italy’s coercive officials originated as messengers—comparable to process servers in the modern American legal system—in the years around 1200. But as communal courts sponsored new procedures that enabled creditors to swiftly recover debts, court messengers were tasked with coercive services for which creditors could pay—namely, the seizure of debtors’ property or, if necessary, the arrest and incarceration of debtors themselves. The earliest coercive officials, although known by different terms from city to city, closely resembled one another by the end of the thirteenth century. I call this prototypical coercive official a “sergeant.” Sergeants had their analogues elsewhere in the medieval Mediterranean, even in northern Europe, but the surpassingly rich archives of a few Italian cities make it possible to study sergeants at a near-ethnographic level of detail. I use one such city in western Tuscany, Lucca, as my central case study. Drawing upon the tools of institutional history, prosopography, anthropology, and social network analysis, I seek to explain why coercive officialdom took an especially brutal turn in Lucca, and possibly other cities like it, in the decades after 1300. Chapter 1 examines the legislative compendia, or “statutes,” that defined coercive officialdom in sixty-five Italian cities between about 1175 and 1360. These reveal how the office became increasingly brutal as it responded to the demands of creditors and communal administrations. Chapter 2 turns to the case of Lucca, concentrating on the 1330s and early 1340s. Here, we can see how the dictates of the office could be tempered by the social environment in which sergeants—called “heralds” (nuntii) in Lucca, as in other Tuscan cities—were embedded. However, the Lucchese evidence also reveals how the technology of coercive officialdom could directly serve the state. In Lucca, the exaction of taxes, fines, and other debts owed to the commune itself was not left to sergeants, but to officials called “retainers” (familiares). I use digital techniques to study the social networks that formed among sergeants, retainers, and the sureties they presented for office, showing that these two communities of coercive officialdom experienced the city around them in fundamentally divergent ways. Retainers, unlike sergeants, were largely excluded from Lucchese society and free to be shaped into “zealots of justice,” to use the memorable expression that one retainer applied to himself and his colleagues. In practice, “zeal” often meant brutality. Chapter 3 delves into the world of retainers and their culture of brutality, which I argue was fostered by the institutions they served. Indeed, even as the Lucchese commune made a show of condemning the worst of this brutality, a regime of impunity prevailed. Chapter 4 shifts perspective and considers the resistance that brutality engendered, especially in Lucca’s countryside. Examining a decade of resistance, from 1334 to 1344, I show that the Lucchese commune authorized techniques of coercion that evoked the predatory tactics of marauding armies. Brutality of this kind often met with collective, organized resistance. While this dissertation charts the intensification of state-sponsored violence in the cities of late medieval Italy, it also shows that the trend toward brutality was far from inevitable or sustainable.Histor

Identification and characterization of unique enzymatic transformations by gut microbes

The human gut microbiome is a diverse community of microorganisms that catalyze millions of unique biotransformations of both endogenous and exogenous compounds. The production and modification of these microbial products can influence both other gut microbes and the human host, having impacts on health and disease. Characterizing these biotransformations is an important part of understanding the functions of the gut microbiome and a key step in the development of microbiome-directed therapies. In this thesis, I describe my work identifying and characterizing several unique microbial enzymes and the conditions necessary for their activity. In chapter 2, I describe our identification of a steroid 21-dehydroxylase present in gut microbial species Eggerthella and Gordonibacter that transforms glucocorticoid steroids into progestins. My work in this chapter focuses on understanding the role of hydrogen production by E. coli and other bacteria in facilitating this reduction, characterizing the genetic and metabolic regulation of the steroid 21-dehydroxylase, and developing protein purification parameters both to confirm our identified enzyme and to provide a framework for subsequent mechanistic studies. In chapter 3, we introduce a new biochemical transformation for microbiome— sulfonation. Sulfonation is an important biochemical transformation that has long been attributed solely to host metabolism. We showed that the gut commensal Bacteroides thetaiotaomicron encodes for a sulfotransferase (SULT) enzyme capable of catalyzing the sulfonation of cholesterol and structurally related steroidal molecules (BT0416 or BtSULT). Our discovery and characterization of this enzyme revealed that it is structurally selective for substrates with a “planar” 5α-trans or 5-ene A/B ring structure within the steroidal core. Additionally, accompanying in vivo studies in monocolonized germ free (GF) mice showed that the presence of this bacterial gene increased cholesterol sulfate (ChS) levels and reduced T cell migration to the mesenteric lymph nodes, showing the potential for sulfated products of the gut microbiome to influence host biology. In chapter 4, we follow up on our discovery of BtSULT, seeking to identify and study new sulfotransferases across the microbiome. Sulfated metabolites have important roles in regulation of metabolism, immune cell function and migration, and disease phenotypes; therefore, understanding the role of the microbiome in producing sulfated metabolites is an important area of study. To identify and study SULTs across the microbiome, we leveraged PAPS biosynthesis to integrate a stable isotope labeled sulfate moiety into sulfated metabolites both in bacterial monoculture and in vivo mouse samples. Using a combination of comparative methods and high-resolution mass spectrometry, we identified hundreds of sulfated features in mouse tissues and several new chemical classes from bacterial cultures. We identified sulfated hydroxy fatty acids as a new type of microbiome-derived sulfated metabolite and identified a candidate sulfotransferase enzyme encoded in the genome of Eubacterium ramulus ATCC 29099. The data from these exploratory studies will inform future investigations of other classes of sulfated metabolites and provide a framework for studying their SULTs. In all, these studies contribute to our understanding of gut bacterial enzymes, their metabolic and genetic regulation, and the biological activities of their products. The tools used in these studies will facilitate future studies of gut bacterial enzymes and the small molecule metabolites that they produce.Chemical Biolog