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Relationship Characteristics And Self-Care In Adults With Heart Failure
No full textHeart failure (HF) is a chronic and progressive syndrome of cardiac impairment, affecting nearly 6 million U.S. adults. Four out of every ten persons with HF will die within 5-years of the first acute hospitalization and prevalence is expected to increase substantially. Managing HF requires the routine practice of self-care and may be influenced by family and friend caregivers. Self-care is a process of maintaining health through health promoting practices and managing illness. Interpersonal factors that may influence HF self-care include caregiver autonomy support, relationship quality and dyad gender. Caregiver autonomy support is a dynamic behavioral process whose purpose is to empower the adult with chronic illness to make fully informed, self-determined choices. Relationship quality is characterized by satisfaction, gratification or meaning between the person with illness and their caregiver. Dyad gender represents a multidimensional relation between individual dyad members, social, and structural processes. Despite their significance to self-care, little is known about characteristics that may make caregivers more or less effective in their roles. This dissertation will examine the characteristics of autonomy support, relationship quality and dyad gender in the effective support of self-care. Article 1 systematically reviews and synthesizes results of caregiver autonomy support interventions for chronic illness. Articles 2 and 3 use data from an intervention that incorporates principles of autonomy support (motivational interviewing) for HF. Article 2 employs logistic regression on longitudinal data to determine characteristics impacting response to motivational interviewing. Article 3 examines dyad gender and relationship quality in HF self-care using linear regression on baseline data. Characteristics impacting response to autonomy support included non-ischemic HF etiology, living alone, fewer medications, and relatively higher baseline self-care. Dyad gender was associated with HF self-care for male-male and female-female dyads. Better caregiver relationship quality in these dyads contributed to an additional decrease in patient self-care. Results suggest a relationship between autonomy support and HF self-care. Self-care behaviors may be strengthened through skills-based interventions targeting caregiver autonomy support. Relationship quality and dyad gender may interact to affect self-care, particularly in similar-gender dyads. Results may lead to more effective clinical practice and new research opportunities
Secure Multi-Party Computation In Practice
Get PDFSecure multi-party computation (MPC) is a cryptographic primitive for computing on private data. MPC provides strong privacy guarantees, but practical adoption requires high-quality application design, software development, and resource management. This dissertation aims to identify and reduce barriers to practical deployment of MPC applications.
First, the dissertation evaluates the design, capabilities, and usability of eleven state-of-the-art MPC software frameworks. These frameworks are essential for prototyping MPC applications, but their qualities vary widely; the survey provides insight into their current abilities and limitations. A comprehensive online repository augments the survey, including complete build environments, sample programs, and additional documentation for each framework.
Second, the dissertation applies these lessons in two practical applications of MPC. The first addresses algorithms for assessing stability in financial networks, traditionally designed in a full-information model with a central regulator or data aggregator. This case study describes principles to transform two such algorithms into data-oblivious versions and benchmark their execution under MPC using three frameworks. The second aims to enable unlinkability of payments made with blockchain-based cryptocurrencies. This study uses MPC in conjunction with other privacy techniques to achieve unlinkability in payment channels. Together, these studies illuminate the limitations of existing software, develop guidelines for transforming non-private algorithms into versions suitable for execution under MPC, and illustrate the current practical feasibility of MPC as a solution to a wide variety of applications
Do Managers Learn From Institutional Investors Through Direct Interactions?
No full textPrior evidence suggests that managers learn indirectly from stock prices, which contain private information impounded by informed investors’ trades. However, stock price is an indirect aggregate signal, which is likely to be insufficient for managerial learning. I propose that managers seek out direct interactions with institutional investors as a further mechanism to learn relevant information about their firms. Using investor conferences and investor days as the medium for direct learning, I find that managers seek more direct interactions when they have a high demand for information concerning industry trends and supply chain dynamics, and when they expect their current base of institutional investors to be knowledgeable. I also predict that information learned through direct interactions will be reflected in the manager’s subsequent corporate and personal decisions. I find that the frequency and accuracy of management forecasts increase after direct learning. Comparing insider trades in the same firm-month, trades executed by participating insiders within seven days after a conference earn greater positive abnormal returns, consistent with managers’ information set expanding as a result of their direct learning
Essays On Networks In Macroeconomics And Finance
Get PDFThis thesis consists of three essays that examine theoretically and empirically the implications of networks in business cycles, economic recovery, systemic risk, corporate finance and governance, and asset pricing.
This first chapter emphasizes the role of networks in driving economic recovery from recessions and its role in asset pricing. It is based on a joint work with Yucheng Yang. The speed at which the US economy has recovered from recessions ranges from months to years. We propose a model incorporating the innovation network, the production network, and cross-sectional shocks and show that their interactions jointly explain large variations in the recovery speed across recessions in the US. We show that when the innovation network has low-rank, there exists one key direction: the impact of a shock becomes persistent only if the shock is parallel to this key direction; in contrast, the impact diminishes quickly if the shock parallels to other directions. Empirically, we estimate the model in a state-space form and document a set of new stylized facts of the US economy. First, the innovation network among sectors has low-rank. Second, the innovation network has non-negligible overlap with the production network. Third, recessions with slow recovery are those witnessing sizable negative shock to sectors central to the innovation network. Such network structures and the time-varying sectoral distribution of the shocks can well explain the large variation in the recovery speed across recessions in the US. Finally, we show that the force driving a slow-recovery yields a small but persistent process in consumption growth, and we use this process to explain several puzzles in asset pricing.
The second chapter is based on the joint work with Yiqing Xing and Rakesh Vohra where we explore the agency conflicts in amplifying and propagating a shock in equity cross-holding networks. Unlike the first chapter, here, we emphasize the role of financial network and agency conflicts within the firm. We argue that firm-level agency conflicts and not just the network of interdependencies between firms, play a crucial role in amplifying or muting the propagation of exogenous shocks. Suppose firms can make investment decisions in response to an exogenous shock. If they are subject to default costs or limited liability, their investment decisions mitigate the spread of an initial shock. In the face of interest conflicts or moral hazard, firm-level investment choices amplify an initial shock. Agency conflicts counter the role of network structure in the propagation of shocks. For example, prior work argues that more integrated networks facilitate the propagation of shocks. In the presence of interest conflicts, this effect can be reversed. Under some condition, in a fully diversified network, the aggregate effect of an idiosyncratic shock via propagation does not diminish. This suggests a potentially important role that corporate governance plays in macro fluctuations.
The third chapter is based on the joint work with Yu Shi and Robert Townsend where we show the business groups can significantly change the effect of credit supply shock through the equity-holding networks. Using business registry data from China, we show that internal capital markets in business groups can play the role of a financial intermediary and propagate corporate shareholders’ credit supply shocks to their subsidiaries. An average of 10% local bank credit growth where corporate shareholders are located would increase subsidiaries\u27 investment by 0.6% of their tangible fixed asset value, which accounts for 42.5% (4.3%) of the median (average) investment rateamong these firms. We argue that equity exchanges is one channel through which corporate shareholders transmit bank credit supply shocks to the subsidiaries and provide evidence to support the channel
Mri Assessment Of Maternal Uteroplacental Circulation In Pregnancy
Get PDFHypertensive pregnancy disorders (HPD) such as preeclampsia are highly associated with maternal vascular malperfusion of the placenta, an organ that exchanges nutrients and oxygen between the maternal circulation and the growing fetus. Adverse pregnancy outcomes are difficult to predict because there is insufficient understanding of how poor maternal arterial remodeling leads to disease. There is also a lack of reliable tools to evaluate these changes in early gestation.
The hypothesis of this dissertation was that magnetic resonance imaging (MRI) could noninvasively evaluate uteroplacental function in vivo through a combination of arterial spin labeling (ASL), 4D flow, and time-of-flight (TOF) techniques which were already effective in the evalution of other cardiovascular diseases. These flow and perfusion imaging studies were conducted on human pregnant volunteers in their second and third trimesters at 1.5T. Many of them were also examined by conventional Doppler ultrasound (US) and followed through delivery.
Flow-sensitive Alternating Inversion Recovery (FAIR) ASL MRI with background suppression was found to be feasible in detecting placental perfusion signal despite the presence of motion artifacts. An important consideration when studying placental ASL was the slow movement of maternal arterial blood in a large cavity called the intervillous space. This was a unique feature of placental anatomy which distinguished it from other organs containing capillaries. It became apparent that traditional models to estimate perfusion from MRI were no longer applicable. In this work, a statistical approach was first developed to filter out motion artifacts, followed by a coordinate transformation to better represent the lobular distribution of blood flow in the intervillous space of the placenta. The uterine arteries (UtAs) are the main maternal blood supply of the placenta and have also long been suspected to be involved in HPD, though US-based measurements have not yet been found to be highly predictive for widespread clinical use. In this work, 4D flow MRI enabled visualization of the tortuous UtAs while measuring volumetric flow rate. Its performance in predicting incidence of preeclampsia and small-for-gestational age births was comparable to Doppler US. When considering the innovative potential of 4D flow MRI to capture complex flow dynamics, this validation demonstrated the value of continuing technical development for improving HPD risk assessment. Furthermore, centerline extraction of the maternal pelvic arteries in TOF MRI, from the descending aorta to the UtAs and external iliac arteries, provided quantitative metrics to characterize the geometry including path length and curvature. Pulse wave velocity (PWV) was estimated using path length by TOF MRI and velocimetry by 2D phase contrast and 4D flow MRI with results showing sensitivity to differences between UtAs and external iliac arteries. These approaches provided physiological metrics to explore and characterize the remodeling process of the uteroplacental arteries. This dissertation demonstrates the feasibility of measuring structure and hemodynamics of the maternal vascular blood supply using non-contrast MRI that can lead to the more reliable biomarkers of adverse pregnancy outcomes needed to diagnose and treat HPD
Global Gatekeepers: How Institutions Regulate And Constrain Migration Flows
No full textSkilled migrants are moving through global circuits in strategic sites of the global economy, bringing with them advanced expertise and knowledge. These migrants are engaging in complex and non-linear migration patterns across the life-course, yet these patterns are difficult to study empirically with existing data due to the increasing scale and dynamism of global skilled migration. This dissertation develops novel data sources that allow for new approaches to the study of skilled migration in institutional, transnational and longitudinal perspective across the life-course. These new tools are better able to capture dynamic migration flows as migrants move between countries in the transnational labor market in complex ways that standard survey data are not able to examine due to temporal and spatial issues the methodological design of many cross-sectional and national-level datasets. Drawing on quantitative analysis of employment histories of 7,177 migrants and qualitative analysis of 105 in-depth interviews, I show that overlapping institutional arrangements influence the development, flow and settlement of skilled migration. The empirical analysis centers on a comparison of Indian skilled migrants with degrees from American and Indian universities, focusing on place of education as a key driver of variation in migrant pathways and settlement behavior. Each of the three empirical chapters explore the close relationship between education, work and migration. First, I find that migration policies are simultaneously leading to convergence and differentiation between educational attainment in U.S. and Indian university systems. Further, country of education influences migrants’ occupational attainment in the country of first job and current job. Finally, employer-sponsored visas constrain the development of foreign skill and can contribute to return migration. These findings have methodological implications for studying skilled migration in transnational and longitudinal perspective. They also illuminate new concepts in migration studies, underscoring the overlapping institutional arrangements between state and non-state actors in regulating the flow and incorporation of skilled migrants
Topics In Mirror Symmetry For Fano Varieties And Meromorphic Ddp Correspondence
Get PDFThis thesis consists of two parts, each of which can be read independently. The first part is about mirror symmetry of Fano varieties and related topics. We introduce the notion of a hybrid Landau-Ginzburg (LG) model, which is a mirror partner of a Fano variety with a chosen anti-canonical divisor. We formulate Kontsevich\u27s homological mirror symmetry conjecture of such mirror pairs and show that it implies the mirror P=W conjecture, a refined Hodge number relation between associated mirror log Calabi-Yau varieties. Next, we discuss the deformation theory of hybrid LG models and related Hodge numbers. The second part is based on a joint work with Jia-choon Lee. We study the relation between Hitchin system and Calabi-Yau integrable system in the meromorphic setting of type A, motivated by the work of Diaconescu-Donagi-Pantev. We consider a symplectization of the meromorphic Hitchin integrable system, which is a semi-polarized integrable system in the sense of Kontsevich and Soibelman. On the Hitchin side, we show that the moduli space of unordered diagonally framed Higgs bundles forms an integrable system in this sense and recovers the meromorphic Hitchin system as the fiberwise compact quotient. Then we construct a new family of quasi-projective Calabi-Yau threefolds and show that its relative intermediate Jacobian fibration, as a semi-polarized integrable system, is isomorphic to the moduli space of unordered diagonally framed Higgs bundles
Entanglement Structure And The Emergence Of Spacetime
Get PDFWe explore connections between macroscopic wormholes, quantum entanglement, quantum circuit complexity, and quantum chaos in the context of the anti-de Sitter / conformal field theory (AdS/CFT) correspondence. We first describe the construction of a single-boundary wormhole geometry in type IIB supergravity, which has a dual interpretation in terms of entanglement between sectors of a Higgsed Super Yang-Mills theory. The construction involves a CPT twist in the gluing of the wormhole to the exterior throats that gives a global monodromy to some coordinates while preserving orientability. We argue that the solution can be made long-lived by appropriate choice of parameters, and comment on mechanisms for generating traversability. We also describe a construction of a double wormhole between two universes. Motivated by the study of entanglement structures that support wormhole topologies, we study how the quantum circuit complexity in field theory quantifies the difficulty of distributing entanglement among multiple parties. We develop an Euler-Arnold formalism for computing complexity based on Nielsen\u27s geometrization of gate counting. Applying this formalism to Gaussian states of the harmonic oscillator that possess a multiparty entanglement structure analogous to multiboundary wormhole configurations, we find a scaling with entropy that resembles a result for the interior volume of holographic multiboundary wormholes. We also study the complexity of time evolution, which was recently conjectured to be related to properties of wormhole interiors. This complexity grows linearly at early times until the minimal geodesic on the unitary manifold encounters an obstruction in the form of a conjugate point or geodesic loop. By explicitly locating these obstructions through analytical and numerical techniques, we demonstrate a complexity hierarchy: the complexity of time evolution is upper bounded by in free theories, in interacting integrable theories, and in chaotic theories. We discuss the interpretation of these results in AdS/CFT, where wormhole solutions demonstrate quantum chaotic behavior
Agreement in K’iche’ (Mayan): Reflections on Microvariation and Acquisi- tion
Get PDFWe explore plausible acquisition trajectories that give rise to microvariation in 3PL agreement realization in K’iche’ (Mayan). We report elicitation data with two speakers of the language. For one speaker, all inanimate 3PL arguments control agreement optionally. For another speaker, inanimate 3PL arguments base-generated in a specifier position control agreement obligatorily, while those base-generated in complement position control agreement optionally. Taking England (2011)’s corpus study of the language as a starting point, we show how the interplay of universal and non-universal factors during acquisition might give rise to these different grammars
Learnability of a Phonetically Null Segment
Get PDFThis paper investigates why two classes of French words, both of which contain words that in isolation are phonetically realized as vowel-initial, vary with respect to elision when pronounced right-adjacent to a definite article: one class does not trigger the deletion of the expendable vowel, while the other class does. It is argued that these two classes differ in that one contains underlyingly vowel-initial words, while the other class consists of words whose underlying representations contain an underspecified consonant segment (termed a ghost consonant; Kiparsky, 2003). The paper also addresses how a learner could posit a ghost consonant in the underlying representation of this second class of words given that the ghost consonant is phonetically null. Through Inconsistency Detection (Tesar, 2004) and Presence Feature setting (Nyman & Tesar, 2019) the learner is able to posit a phonetically null segment, resulting in the resolution of a ranking paradox that would otherwise obtain