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Enduring Impacts of Child Development Accounts: Increased Parental Expectations and College Preparation
No full textParental educational expectations exert a substantial influence on children’s educational achievement. Elevated parental expectations can move families to prepare for a child’s education beyond high school, both by intentional planning and financial steps to increase the likelihood of attending higher education. This Research Brief explores findings from a detailed study of long-term positive impacts of Child Development Accounts on parental educational expectations and college preparation. Drawing upon analyses of the pre-COVID data collected in 2020 as part of Wave 3 of the SEED for Oklahoma Kids experiment, the brief highlight effects sustained over 13 years.
A full reporting of the results may be found in Sun and colleagues (2025), “The Long-Term Impacts of Child Development Accounts on Parental Educational Expectations and College Preparation,” Social Service Review, 99(2), 326–363. https://doi.org/10.1086/735543
Depalmitoylation regulates metabolism and mitochondrial function
Get PDFTens of millions of Americans suffer from metabolic disorders, predisposing patients to cardiovascular disease, kidney disease, liver disease, infertility, and cancer. Unfortunately, the etiology of many of these diseases remains a mystery, limiting our ability to identify targets for pharmacologic therapies. Due to the relationship between altered lipid dynamics and metabolic dysfunction, we decided to study the effect of the posttranslational lipid modification, S-palmitoylation, on metabolism. S-palmitoylation is the only known reversible lipid modification for proteins, and this depalmitoylation process is catalyzed by acyl-protein thioesterases including APT1 and APT2. We hypothesized that APT deficiency in various tissues would predispose mammals to metabolic disease. We generated mice with APT deficiency in endothelial cells, pancreatic beta cells, or the liver. We found that endothelial APT1 deficiency impaired recovery of perfusion in a mouse model of peripheral artery disease. Next, we discovered that APT1-deficient beta cells hypersecrete insulin, which leads to early beta cell failure in genetic and dietary models of type 2 diabetes. We then determined that hepatic APT1 and APT2 regulate insulin sensitivity and glutamine-induced gluconeogenesis, as well as mitochondrial respiration. In each of these studies, we identified several novel APT substrates, as well as new pathways for upstream regulation of APT activity. These findings establish depalmitoylases as critical mediators of metabolic signaling and potential targets for novel therapies
Essays in Macroeconomics
Get PDFThis dissertation is organized into three chapters, each offering novel insights into macroeconomic theory and practice. While the chapters address distinct phenomena, a common thread runs throughout: each study examines a transmission mechanism---whether of monetary shocks, normative change, or academic strategies---and underscores the importance of heterogeneity and dynamic adjustment in macroeconomic outcomes. In Chapter 1, I explore one of the most direct channels of monetary policy transmission---the refinancing window in the housing market. By exploiting comprehensive mortgage data from the Home Mortgage Disclosure Act (HMDA) spanning several decades, the analysis identifies episodes of heightened refinancing activity as quasi-natural experiments. Regions characterized by higher initial house prices and incomes tend to experience larger refinancing booms, which in turn generate significant impacts on employment and consumption. This study illuminates the role of long--term debt contracts, particularly residential mortgages, in transmitting monetary policy into the real economy. Such technical financial decisions, when aggregated across regions, play a central role in shaping macroeconomic dynamics. Chapter 2, coauthored with Antonio Cabrales, David Ramos Mu\~noz, and \\u27{A}ngel S\\u27anchez, broadens the macroeconomic inquiry to issues of sustainability and long--term policy challenges. Despite over fifty years of scientific investigation, climate change has translated unevenly into political and institutional action. In this chapter we construct a Climate Change Index (CCI) by tracking the frequency of climate-related mentions in diverse sources---from mainstream media and European parliamentary questions to scientific journals and central bank speeches. Employing text analysis and vector autoregression (VAR) methods, our study traces how concern about climate change has gradually permeated public debate and policymaking. Notably, while natural science journals have long engaged with the issue, our findings reveal that institutional actors such as the European Parliament and central banks have only recently begun to respond to climate signals, often in tandem with media surges. This contribution advances our understanding of how long--run challenges are communicated and eventually institutionalized, highlighting the interplay between social norms, media narratives, and policy agendas. Chapter 3, coauthored with Harris Dellas, Carlos Garriga, and Christian Zimmermann, shifts the focus to the academic labor market---the arena where economic ideas are produced, debated, and disseminated. Within the ``publish or perish\u27\u27 paradigm, early-career scholars face a critical choice: whether to concentrate narrowly in a single field or to diversify their research output across multiple topics. Drawing on comprehensive data from the RePEc database and using classification measures derived from JEL and NEP codes, we introduce a Specialization--Diversification Index (SDI) to quantify the breadth of an economist’s research portfolio. Our analysis reveals that, contrary to conventional wisdom favoring specialization for short--term gains, a diversified research portfolio is associated with higher quality-adjusted output, broader citation impact, and even a lower risk of academic attrition. By examining both cross-sectional and dynamic patterns, and by addressing potential endogeneity through an instrumental variables approach based on coauthorship networks, this chapter provides novel insights into how research strategy shapes individual careers and the collective production of economic knowledge. Indeed, the academic labor market is itself a critical component of macroeconomic dynamics, for the ideas that inform policy and public debate originate from these very institutions
Understanding and Mitigating Timing Issues in Autonomous Systems
Get PDFAutonomous systems, such as self-driving cars and drones, have become a part of our daily lives. Since these systems operate in and interact with the physical world, their correctness depends on both functional and temporal aspects. However, the increasing complexity of modern computing hardware and software often leads to unpredictable timing behavior in these systems, making temporal properties particularly challenging to ensure. This dissertation proposes novel approaches to specify and enforce temporal properties based on a comprehensive empirical study of real-world issues. The first half of this dissertation presents an empirical study that dissects the timing issues. The dissection begins by re-visiting the fundamental sources of timing uncertainty – hardware performance interference. It systematically characterizes potential timing interference channels. Building on that, the study empirically examines how such timing uncertainty manifests at the software level and how developers address these issues. To this end, the study further collects and analyzes real-world bug case studies, summarizing the pitfalls and challenges developers face in achieving correct temporal properties. The second half of this dissertation brings solutions to the previously identified issues. A new concept, data-flow availability, is proposed for specifying timing constraints. Unlike traditional approaches that express timing constraints from a control-flow perspective (such as scheduling policy or locking protocols), DFA adopts a data-flow perspective, enabling more expressive and precise specification of timing requirements. To demonstrate the practicality of DFA, this dissertation also presents a proof-of-concept system named Kairos. In addition to supporting the core features of DFA, Kairos incorporates a scheduling mechanism that ensures consistency in scheduling decisions across system layers. Finally, the dissertation extends the assurance of temporal properties to adversarial scenarios by introducing a novel recovery scheme. This scheme enables systems to regain availability even when software components are compromised
Real-time System Availability for Cyber-physical Systems
Get PDFCyber-physical systems (CPSs), such as autonomous vehicles, are increasingly being deployed. The sensing, control, and actuation loop in CPSs must complete within strict timing constraints. Missing a real-time deadline can lead to catastrophic consequences, as CPSs continuously interact with the physical world. This highlights the importance of real-time system availability (i.e., timely execution) in CPS tasks, going beyond traditional security goals that primarily focus on confidentiality and integrity. From a security perspective, two factors affect real-time system availability. First, attackers with access to hardware resources in CPSs may disrupt the execution timing of real-time tasks. Second, the deployment of security mechanisms inevitably introduces runtime overhead, which can also impact task execution timing. This dissertation presents security mechanisms designed to ensure real-time availability from the following two perspectives. Defending Against Denial-of-Service (DoS) Attacks from the Privileged Software Stack: Privileged software, such as the operating system, manages hardware resources. When compromised, it may prevent security-sensitive tasks in CPSs, such as control tasks, from accessing the CPU or I/O devices in a timely manner. This dissertation first presents a real-time trusted execution environment (RT-TEE) to guarantee secure and timely access to the CPU and I/O devices for security-critical CPU tasks, even under a compromised operating system. With the increasing deployment of GPUs in CPSs to accelerate AI workloads, ensuring the timely execution of GPU tasks has also become essential. To address this, the dissertation then presents a real-time trusted execution environment for GPUs, called AvaGPU, which guarantees secure and timely access to GPU resources for security-critical GPU tasks under a compromised operating system. Real-time Performance Guaranteed Security Mechanisms: Deploying security mechanisms in real-time systems can lead to deadline misses, posing challenges to system reliability. To address this, this dissertation proposes efficient security mechanisms that are designed with real-time performance in mind. In particular, it introduces ARI, a policy-based mechanism for attesting the integrity of real-time mission execution. ARI enables a practical trade-off between security and real-time performance, overcoming the high runtime overhead associated with existing state-of-the-art solutions
Retirement Plan Access among Low-Wage Workers in 2024: Implications for SECURE 2.0
Get PDFHouseholds in the United States struggle to save for retirement, and the problem is acute for low- to moderate-income (LMI) households. In 2022, the federal SECURE 2.0 Act created an expansive suite of policy approaches to facilitate saving in LMI households. This brief discusses key provisions of the act and presents findings from the Workforce Economic Inclusion and Mobility (WEIM) survey of a nationally representative sample of vulnerable workers in the United States. The findings suggest opportunities to improve upon the SECURE 2.0 Act’s provisions
GS-1: A UHF Ground Station for LEO Satellite Communication
Get PDFThe WashU Satellite Ground Station-1 is the team’s second project and first infrastructure step toward reviving WashU’s presence in space. It provides support for our upcoming CubeSat project, SCALAR, and lays the groundwork for future missions. With this project, we are developing a robust, high-performance system that prioritizes student design opportunities and thoroughness of the final system over a reliance on COTS solutions or minimizing engineering time. The project also serves as our first experience with management of a complex technical project.
GS-1 features a 3.5m, 16-17 dBiC gain, Yagi antenna connected to a HackRF software defined radio (SDR) with custom-designed RF front end electronics. The antenna is mounted with a custom AZ/EL rotating arm, mast, and frame capable of withstanding high winds and St. Louis winters. A CCDS-compatible packet structure was created, along with web-accessible software to support command/control, status visualization, and data transfers
Panel to Paragraph: How Comics Made Me a Writer
Get PDFGraduate winner: 1st place, 2025, 38th Annual Carl Neureuther Student Book Collection Competitio
Advances in Simulating Global Fine-Scale Ambient Air Pollutants and Source Contributions
No full textFine-resolution chemical transport models are essential to resolve fine-scale air pollution patterns due to localized emissions, nonlinear chemical feedbacks, and complex meteorology. However, fine-resolution global simulations of air quality remain rare, especially of the Global South. Recent developments to GEOS-Chem model in its high performance configuration (GCHP) enable routinely conducting global air quality simulations at spatial resolution ~60 times finer than the coarse global models traditionally available to the research community (~25 × 25 km2 vs. ~200 × 200 km2). This dissertation is centered on utilizing and improving fine-resolution simulations to produce more accurate spatial estimates of air pollutants combined with satellite-based observations and ground-based measurements. The first section advances fine-scale estimates of population exposure and sectoral contributions from a global fine-resolution simulation with a focus on the Global South. We analyze the discrepancies of population exposure to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) globally and in populous cities between fine and coarse GCHP simulations. We also examine the resolution dependence of sectoral contributions from the differences of fractional contributions of emission sectors across model resolutions with sector sensitivity tests using GCHP. The second section is aimed at investigating the model resolution effects on geophysical satellite-derived PM2.5, inferred from satellite retrieved aerosol optical depth (AOD) and simulated surface PM2.5 to AOD relationship. We compare satellite-derived PM2.5 concentrations across model spatial resolutions using GCHP and examine the overall resolution sensitivities contributed by different PM2.5 components. We further investigate the resolution effects on the simulated aerosol vertical profile, which shows vertical contrast of near-surface emissions and pollutants transported aloft, especially over isolated sources. Mineral dust exerts strong impacts on air quality as the most abundant aerosol by mass, on ecosystem health through nutrient transport and deposition, and on climate change by affecting the radiative budget globally. The third section is targeted at improving fine mineral dust representation in GEOS-Chem from the surface to the column against satellite-based and ground-based observations, leveraging recent mechanistic understanding of dust source and removal. Specifically, we implement a new dust emission scheme, revisit the size distribution of emitted dust, explicitly track dust with diameter less than 2 μm, and update the parametrization for below-cloud scavenging. In summary, these investigations highlight the capability of a global fine-resolution simulation by the GEOS-Chem model in better resolving the spatial heterogeneity of air pollution due to distinct sources, chemical nonlinearities, and complex meteorology, with implications for location-specific emission mitigation strategies. Model developments to fine mineral dust indicate the importance of consistent representation of size in models versus measurements, the spatial distribution of dust emissions, the size distribution of emitted dust, and the explicit tracking of fine bins for more accurate simulation of fine dust abundance from the surface to the column
Savings Incentives and the SECURE 2.0 Act: New Evidence on Employer-Sponsored Emergency Savings Accounts and the Saver’s Match
Get PDFcredit. Analyses drawn upon data from the Workforce Economic Inclusion and Mobility Survey, a survey experiment testing the appeal of employer-sponsored emergency savings accounts. The findings indicate that interest in employer-sponsored emergency savings programs is generally high and that, for low-wage workers, offers of matching contributions are more salient than automatic contributions.
IMPLICATIONS for SECURE 2.0 This is the first research brief in a series examining the implications of the SECURE 2.0 Act for the retirement security of low-wage workers in the United States. All briefs in the Implications for SECURE 2.0 series can be found at https://csd.wustl.edu/tag/secure-2.0