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The Term Structure of Stock-Bond Covariances
Get PDFI study the term structure of stock-bond covariances after the Global Financial Crisis. The term structure of covariances refers to the covariance between the aggregate market and government bonds of different maturities. I establish five new facts about the term structure of covariances: (1) The average term structure of covariances is downward sloping: long-maturity covariances are more negative than their short-maturity counterparts, whereas the term structure is flat across maturities before the crisis. (2) After the crisis, short-maturity covariances are acyclical. Short-maturity covariances are of the same magnitude in good and bad times, and so are acyclical. In contrast, long-maturity covariances are more negative in bad times, and so are countercyclical. Taken together, the first two facts imply that short-maturity bonds have weaker hedging properties relative to long-maturity bonds. (3) To generalize the intuition from the first two facts, I run regressions of long-maturity covariances on short-maturity covariances in changes. Before 2007, the sensitivity of long to short, the regression slope, is about one and stable. After 2010, the sensitivity roughly doubles. (4) The sensitivity of long to short is related to unconventional monetary policy. First, in the United States, the sensitivity rises only after the announcement of large-scale asset purchases and varies with Post-GFC programs implemented by the Federal Reserve. Second, around the world, the rise in the sensitivity is larger in countries with larger quantitative easing programs. (5) The break in the term structure has implications for bond risk premia. I construct a stock-bond factor, analogous to the Cochrane-Piazzesi factor, from the term structure of covariances. After the crisis but not before, the stock-bond factor predicts bond excess returns, even after controlling for typical predictors of bond returns. These five facts provide new directions for the literature on stock-bond comovement
Breaking Anterior–Posterior Symmetry in the Moth Fly Clogmia albipunctata
Get PDFForming the anterior-posterior (AP) body axis is a fundamental process during embryogenesis. In flies (Diptera), symmetry breaking along the AP axis requires anterior determinants (ADs) that differ between species. In Drosophila melanogaster, localized mRNA of bicoid serves as the AD. Once translated, the Bicoid protein competes with nucleosomes and initiates symmetry-breaking along the AP axis by promoting chromatin accessibility at the lociof segmentation genes that are required to pattern the anterior embryo. The ADs of other dipteran insects are encoded by transcription factor (TF) genes that are unrelated to Bicoid, and little is known about they function and if they act through a shared mechanism. This study uses a de novo assembly and annotation of the genome of the moth fly Clogmia albipunctata to investigate whether the AD of this species initiates symmetry breaking along the AP axis during zygotic genome activation at the level of chromatin accessibility. In Clogmia, a maternally expressed transcript isoform of the pair-rule segmentation gene odd-paired is localized in the anterior egg and has been co-opted as the AD. I first describe the dynamics of chromatin accessibility during the last nuclear cycles before gastrulation. I find that in Clogmia, similar to Drosophila, the chromatin landscape progressively opens throughout development encompassing widespread zygotic transcription. However, following their initial opening, many regions close at earlier nuclear cycles in Clogmia than when such widespread changes occur in Drosophila. I investigate how knockdown of the pioneer factor gene zelda affects the chromatin landscape in Clogmia and find that Clogmia’s zelda homolog is important for both opening and closing chromatin. I then show that maternal odd-paired activity promotes chromatin accessibility and anterior gene expression during the early phase of zygotic genome activation at Clogmia’s homeobrain and sloppy-paired loci. These loci differ from the key targets of Bicoid but given that homologs homeobrain and sloppy-paired have early anterior expression domains and function in head development in Drosophila and other insects, these genes may serve a more widely conserved role in the initiation of anterior pattern formation. I conclude that unrelated dipteran ADs initiate anterior-posterior axis-specification at the level of enhancer accessibility through distinct sets of target genes. My study motivates further investigation into how the network downstream of the primary AD targets converges in different dipteran species to yield the conserved segmented body plan
Independent Roles of Hypusinated and Unhypusinated eIF5A in Pancreas Growth and Development
Get PDFThe growth of the pancreas, including that of insulin-producing β cells, is dependent on the regulation of protein translation. The eukaryotic translation elongation factor eIF5A, when hypusinated by dexoyhypusine synthase (DHPS), is important for normal protein translation. Inhibition of DHPS impairs translation, growth, and proliferation of pancreatic cells; however, it is unknown if these consequences are due to loss of hypusinated eIF5A (eIF5AHyp) or to the accumulation of unhypusinated eIF5A (eIF5ALys). This dissertation interrogates this question through two main aims. First, DHPS or eIF5A expression is impaired in zebrafish embryos and in the β cells of HFD-fed mice. By comparing the phenotypes of these animals, it is possible to discern whether eIF5ALys has an active role in the inhibited pancreas tissue growth caused by DHPS loss. Second, pathways of eIF5ALys action are investigated by RNA-sequencing, and cell culture is used to detect interactions between eIF5ALys and proteins highlighted by RNA-sequencing. Overall, the data presented support the conclusion that eIF5ALys actively impairs pancreas cell growth by suppressing translation initiation through the integrated stress response kinase GCN2. This is a completely novel finding, as no independent function of eIF5ALys has been documented to dat
Interfacial and Nanoconfined Metal Architectures for Aqueous Electrochemical Energy Storage and Carbon Dioxide Reduction
No full textAddressing global energy and environmental challenges requires integrated solutions that enable both sustainable energy storage and carbon dioxide utilization. This dissertation investigates interfacial and nanoconfined metal architectures for two key aqueous electrochemical systems: Sn metal-based batteries and electrochemical CO2 reduction toward high multi-carbon products. These two systems are unified by a common strategy, molecular-level control of interfacial chemistry and microenvironment to overcome efficiency, selectivity, and stability limitations. In aqueous Sn metal batteries, challenges such as poor reversibility caused by dead Sn formation and hydrogen evolution are mitigated through interfacial engineering (Chapter 2) and co-cation regulation (Chapter 3). The inertness of Sn toward hydrogen evolution and its isotropic growth behavior makes it particularly well-suited for aqueous environments, especially under acidic conditions where traditional Zn-based batteries struggle. Through surface modification and electrolyte optimization, these works achieve high Coulombic efficiency, extended cycling life, and competitive energy densities, establishing Sn as a viable alternative anode for aqueous battery technologies. In parallel, this dissertation explores the role of nanoconfinement and microenvironment modulation in steering eCO2RR selectivity. Cu single atom-based catalysts supported on microporous carbon frameworks are developed to enhance *CO intermediate stabilization and promote C–C and C2–C1 coupling (Chapter 4). These catalysts exhibit high Faradaic efficiency toward C2+ alcohol products, including glycerol and ethanol. Structure–function relationships reveal that micropore size and adsorption enthalpy play key roles in controlling reaction pathways, intermediate coverage, and product branching. Together, these studies establish a coherent design framework in which interfacial chemistry, ion transport, and nanoconfinement are leveraged to enhance the performance of aqueous electrochemical systems. By connecting insights from energy storage and CO2 conversion, these works contribute fundamental understanding and practical strategies toward multifunctional electrochemical platforms that support carbon neutrality and sustainable energy integration.</p
Carbon Stars as Standard Candles: An Empirical Test for the Reddening, Metallicity, and Age Sensitivity of the J-region Asymptotic Giant Branch (JAGB) Method
Get PDFThe J-region Asymptotic Giant Branch (JAGB) method is a standard candle based on the intrinsic luminosities of carbon stars in the near infrared. We directly constrain the impact of metallicity, age, and reddening on the JAGB method. We assess how the mode, skew, and spread of the JAGB star luminosity function change throughout diverse stellar environments in M31's NE disk from 13<d<18 kpc using data from the Panchromatic Hubble Andromeda Treasury (PHAT). As expected, the mode is found to be fainter in higher-reddening regions. To cross-check this result, we also measure a fiducial J-band ground-based JAGB distance using data from the UKIRT/WFCam in M31's outermost disk (18<d<40 kpc) where internal reddening is minimal. We find that this J-band distance modulus agrees well with the F110W distance moduli measured in the lowest reddening regions of the PHAT data, demonstrating the JAGB method is most accurate if measured in the low-reddening outer disks of galaxies. On the other hand, the mode of the JAGB star luminosity function appears empirically to show no dependence on age or metallicity within the range -0.18<[M/H]<-0.26 dex. In conclusion, the JAGB method proves to be a robust standard candle capable of calibrating the luminosities of type Ia supernovae and therefore providing a high-accuracy, high-precision measurement of the Hubble constant
Short two-qubit pulse sequences for exchange-only spin qubits in two-dimensional layouts
Get PDFExchange-only (EO) spin qubits in quantum dots offer an expansive design landscape for engineering scalable device layouts. The study of two-EO-qubit operations, which involve six electrons in six quantum dots, has so far been limited to a small number of possible configurations, and previous works lack analyses of design considerations and implications for quantum error correction. Using a simple and fast optimization method, we generate complete pulse sequences for cx, cz, swap, leakage-controlled cx, and leakage-controlled cz two-qubit gates on 450 unique planar six-dot topologies and analyze differences in sequence length (up to 43% reduction) across topology classes. In addition, we show that relaxing constraints on postoperation spin locations can yield further reductions in sequence length; conversely, constraining these locations in a particular way generates a cxswap operation with minimal additional cost over a standard cx. We integrate this pulse library into the Intel quantum stack and experimentally verify pulse sequences on a Tunnel Falls chip for different operations in a linear-connectivity device to confirm that they work as expected. Finally, we explore architectural implications of these results for quantum error correction. Our work guides hardware and software design choices for future implementations of scalable quantum-dot architectures
Transforming Violence Recovery Through Crime Victim Compensation
Get PDFCrime victim compensation (CVC) is intended to reimburse victims of violent crime for expenses such as medical bills and lost wages incurred from their victimization. Today, all 50 states operate CVC programs, overseeing the allocation of state and federal funds. CVC has the potential to significantly support violent crime victims during their recovery, but research has shown that few people successfully access CVC. Hospitals are often the first and only access portal violent crime victims have within the healthcare system. Hospital-based violence intervention programs (HVIPs) are uniquely positioned to support patients’ comprehensive injury recovery and assist them access social benefits, like CVC. Conducting a mixed-methods study, I quantitatively described the extent of CVC underutilization in Illinois, comparing number of CVC claims to total reported incidents of violent crime, showing low application rates and high denial rates particularly for victims of assault, sexual assault and domestic violence. Circulating a survey to HVIPs nationwide and conducting qualitative interviews with HVIP workers, it became clear that they are often the most likely members of the trauma care team to assist patients with the CVC application process. Complicated application requirements, and stringent eligibility criteria were identified by HVIP workers as significant barriers for their patients trying to access CVC. While impactful when efficiently awarded, HVIP workers often describe how CVC is currently inadequate at substantively addressing their patient’s recovery needs. Informed by HVIP workers’ insights, this study offers several policy recommendations to transform CVC into a reparative policy tool to aid violence recovery
Punishing Poverty: A Lockean Immanent Critique of American Incarceration and the Criminalization of Survival
Get PDFAs a joint thesis in public policy and philosophy, this project interrogates the American criminal justice system’s violation of foundational social contract principles through its criminalization of poverty. Grounded in John Locke’s Second Treatise of Government and the Capabilities Approach, I develop the concept of “poverty-induced crime” to argue that survival-based criminal offenses, committed in pursuit of basic needs, are morally defensible yet rendered invisible by prevailing formal legal frameworks. This theoretical intervention responds to the legal system’s failure to adequately account for motivational context in formal criminal adjudication. The thesis presents a comparative analysis of Locke’s political theory and the structural realities of poverty-induced crime. Moreover, the latter portion of this thesis uses real-word case studies to uncover the deep contradictions within American society that risk precipitating a regression toward the very state of nature the social contract seeks to overcome
A Blueprint for Equity: The Impact of the Affordable Requirements Ordinance on Segregation in Chicago
Get PDFKnown as one of the most segregated cities in the United States, Chicago, Illinois has instated a variety of policies in an attempt to address residential segregation. One of their most celebrated policies, the Affordable Requirements Ordinance (ARO), is an inclusionary zoning policy that intentionally tries to create more integrated communities. Though inclusionary zoning policies across the country have successfully increased the amount of affordable housing units, little is known about whether the policy is actually forwarding racial and socioeconomic integration. Using a mixed methods approach, I assess the implementation of the ARO and find that the policy is providing equity for Black Chicagoans, but that it is only effective at a small scale. Specifically, quantitative data reveals that a majority of the affordable units are going to Black individuals; however, qualitative data reveals many aspects of the policy that are quite contentious. The findings presented here fill gaps in the literature about inclusionary zoning’s ability to break up residential segregation, and can help inform further improvements to the ARO and other similar inclusionary zoning policies
<i>intimacies, interruptions</i> for Orchestra
Get PDFintimacies, interruptions is a work for full orchestra that is inspired by the furtive moments that exist only within the cracks and fissures of today's hyper-fast and fragmented life-world. The piece opens with a sweeping, post-romantic, but also fragmented motivic idea reminiscent of Wagner or Mahler. This material is quickly consumed by the hyper-organism of the orchestra, which digests it along with a more contemporary syntax. This process yields various forms of sentimental expressivity, including from the post-romantic material itself. In the age of oversaturation and instant gratification, sitting down and sharing a traditional concert hall ritual can open the door to a surprisingly radical kind of intimacy. Threads of lyricism are strewn throughout this work, but they are often presented alongside a shifting cornucopia of orchestral color. A rich diversity of musical material and techniques of ensemble coordination create the tensions and contradictions that shape one level of this work. As these contrasting musical materials collide with and interrupt each other, the resonances they leave behind trace subtle, ephemeral connections. Like the realism of Caravaggio, which invited audiences to question the line between what was real and what was painting, I invite the audience to use this work as a tool for reflection on the contemporary problem of intimacy. In the concert hall we can experience intimacy, paradoxically, in a room of hundreds of people. Today, at all times, or at no time, can we truly know each other intimately? intimacies, interruptions was premiered by the Louisville Orchestra, conducted by Teddy Abrams, at Whitney Hall, Louisville, Kentucky, in November 2024. The piece has been performed twice in its complete form. The work was also read and recorded in a partial draft form at the Aspen Music Festival by the Aspen Conducting Academy Orchestra, conducted by Filip Huget in July and August 2023. The full draft was also read and recorded by the Louisville Orchestra in September 2024