VictorJuiz/thesis huggingface dataset:
Engineering solid-state platforms for quantum photonics
Keywords: Electrical Engineering.

Essential to the development of hardware for optical quantum information processing is the integration of solid-state quantum emitters into low-loss photonics. Quantum emitters provide discrete energy levels, which can be used as qubit states and driven with photons. This light-matter interaction enables the generation, manipulation, and transmission of information. Photonic devices allow us to confine light at the nanoscale to enhance the interaction between local (quantum emitter) and flying (photon) qubits. In recent years, extensive research has been conducted to find quantum emitters with narrow linewidths, high quantum efficiencies, and long coherence times. Some of the most promising quantum emitters have been incorporated into photonic devices and have facilitated fundamental studies of light-matter interactions, the development of optical control schemes, and the generation of non-classical light. These works have mostly been confined to single devices with single quantum emitters and current efforts are directed at scaling to photonic circuits connecting arrays of quantum emitters. This endeavor further increases the requirements on quantum emitters, as they have to be generated with nanoscale precision and near-identical properties across the entire chip. Clever engineering of photonics can facilitate meeting these requirements. However, the development of low-loss photonic circuits remains a challenge of its own, as the most promising quantum emitters are hosted in materials non-standard in the photonics industry. The realization of quantum photonic circuits therefore requires the simultaneous development of quantum emitters and their corresponding photonics. In my thesis, I summarize our contributions to the development of quantum photonics. I discuss how we use semiconductor quantum dots strongly coupled to photonic cavities to demonstrate the coherent generation of indistinguishable, on-demand single photons, as well as multiple photons at a time. Such systems could be used as non-classical light sources for quantum communication and measurement-based quantum computation. However, scaling from single devices to large quantum circuits is challenging, due to the prohibitively large inhomogeneous broadening and random positioning of quantum dots. In contrast, color centers are atomic-scale defects, which can be generated in site-specific locations and exhibit much smaller inhomogeneous broadening than quantum dots. We have thus worked to develop color centers in diamond and 4H-silicon carbide and their host materials into scalable quantum photonic platforms. The host materials diamond and 4H-silicon carbide are new in the field of photonics and as such required us to develop novel fabrication protocols. Leveraging these fabrication techniques and inverse-design algorithms that account for fabrication constraints, we developed photonic platforms in diamond and 4H-silicon carbide for classical, nonlinear, and quantum optics
Enhancing humoral immunity with injectable hydrogel platforms for sustained vaccine exposure
Keywords: Bioengineering.

Existing and emerging infectious diseases continue to threaten our population. While vaccine development has progressed over the last several decades, there is still a critical need for improving immunomodulatory technologies to guide the endogenous immune response. As our knowledge of the immune system deepens, it is becoming clear that vaccine components must be in the right place at the right time to orchestrate a potent and durable response. Yet, increasing the potency, quality, and durability of the vaccine response remains a challenge. Material platforms such as nanoparticles, hydrogels, and microneedles can be engineered to spatially and temporally control the interactions of vaccine components with immune cells. Given their emerging role as immunomodulatory tools, these materials have been shown to augment the vaccine immune response by improving innate immune cell activation, creating local inflammatory niches, targeting delivering to lymph nodes, and controlling the timeframe of vaccine delivery. This chapter highlights the critical biological mechanisms for developing a strong humoral immune response and explores how materials have been designed to manipulate them
Entering Public Markets: IPOs and New Alternatives
Keywords:  Public Policy Program
Stanford University
Humanities and Sciences
Public Policy Program
Direct Listing
IPO
Public Offering
Dutch Auction
Venture Capital
Finance
Thesis

The IPO, or initial public offering, has long remained the dominant vehicle with which to enter pubic markets. Despite the existence of other options, few companies have considered, let alone attempted, to use an alternative mechanism. More recently, access to information and the liquidity of private markets has driven fundamental changes to how private companies raise capital, fund growth, and perceive the public markets. How have these changes transformed the growth of today’s private companies, and, as a result, altered not only how executives approach the key considerations of ‘going public’, but also how regulators govern a company’s entrance into those markets? Using historical analysis and modern case studies, I dissect the mechanics of ‘going public’, highlight the critical considerations of stakeholders, introduce pending regulatory changes to current offering mechanics, and finally present a framework through which to evaluate the future entrance of companies into the public markets.
Environmental Surveillance of Typhoidal Salmonellas in the Kathmandu Valley, Nepal
Keywords: typhoid
environmental surveillance
enrichment PCR
Nepal
enteric fever
Thesis

Enteric Fever, the life-threatening illness resulting from infection with Salmonella Typhi and Paratyphi, is endemic throughout much of South Asia. This disease is transmitted through contaminated food and water and most prevalent in areas with poor sanitation systems. To better understand the transmission pathways of typhoid fever causing Salmonella species in the Kathmandu Valley, we have conducted environmental surveillance of both drinking water and surface water within and downstream of the Kathmandu Valley. While previous case control studies posited that household drinking water was the main exposure pathway of typhoidal bacteria in Nepal, we found less than 1% of drinking water samples were contaminated with Salmonella Typhi or Paratyphi A, while river water samples within and up to 10 kilometers downstream of Kathmandu consistently showed high levels of contamination with these disease-causing agents. These results suggest that exposure to Salmonella Typhi and Paratyphi in the Kathmandu Valley may not be caused by contaminated drinking water alone but instead could be due to direct human interaction with contaminated river water or the use of contaminated rivers to water agricultural products sold in Kathmandu markets.
Enzymatic and imaging based approaches to study the mammalian glycocalyx
Keywords: Chemistry.

Every cell in the human body is coated with a peripheral layer of glycosylation. These polysaccharides, glycoproteins, glycolipids, and proteoglycans organize into an extramembrane compartment termed the glycocalyx. The glycocalyx is the cell's first point of contact with the extracellular environment, and is a key regulator of cell-matrix and cell-cell interactions. Investigations into the architecture and dynamics of the glycocalyx stand to benefit from methods to (i) spatially classify glycans at relevant length scales, and (ii) selectively edit glycocalyx components. After an introductory Chapter 1, Chapter 2 describes a super-resolution microscopy based approach for quantification of glycocalyx parameters. Application of this method in the context of pancreatic cancer revealed that oncogenic KRAS changes the glycocalyx in part by promoting the biosynthesis of mucins. Mucins are a class of cell surface glycoprotein that are difficult to study and drug due to their dense glycosylation and resistance to proteases. Chapter 3 describes characterization of a mucin-selective protease derived from the human gut microbiome, which enables selective cleavage and release of mucins from live cells. This tool lowers barriers to the study of native mucin biology and represents a potential strategy for therapeutic intervention in mucin-expressing cancers. Chapter 4 describes unbiased screening in search of mammalian enzymes that proteolyze mucin domains, culminating in the observation that the human lysosomal protease cathepsin D exhibits such activity. The discovery that a human protease cleaves mucin domains without prior deglycosylation has implications for our basic understanding of human mucin catabolism and the consequences when it goes awry
Epidemiologic approaches to investigating the relationship between insulin resistance and major depressive disorder
Keywords: Epidemiology.

Major depressive disorder (MDD) is one of the most prevalent psychiatric disorders in the United States, with one in five adults experiencing the disorder in their lifetimes.1 Yet more than half of people with MDD do not achieve an adequate response to treatment with existing antidepressants, and a substantial subset of these individuals fails to respond to multiple courses of treatment. Considerable effort has been aimed at uncovering the causes of MDD and developing new strategies for treatment and prevention, but more than 90% of behavioral neuroscience results fail to translate to treatments or other effective clinical strategies to treat people with MDD. This dissertation explores whether epidemiology can facilitate this translational process by introducing strategies to evaluate the nature and plausibility of neurobiological findings before the implementation of randomized controlled trials or other expensive and time-consuming psychiatric research. We undertook this translational question by investigating the relationship between MDD and one modifiable risk factor: insulin resistance (IR). IR has been associated with several somatic disorders, including cardiovascular disease, chronic kidney disease, Alzheimer's disease, and MDD. Yet, little is understood about the nature of the relationship between IR and MDD beyond an association between the prevalence of the two conditions. Is possible that IR plays a role in the development, trajectory or treatment of MDD? Chapter 1 of this dissertation evaluated the biological plausibility of relationship between IR and MDD. Chapters 2 and 3 studied the relationship between IR and characteristics and occurrence of MDD in a Dutch cohort. Chapter 4 attempted to address a key question from Chapter 1: is it possible to intervene on the IR-MDD pathway in order to effect depression treatment response? We conducted two emulated target trials to evaluate the causal relationship between an insulin-sensitizer, pioglitazone, and the one-year risk for treatment-resistant depression. Taken together, these studies aimed to expand our understanding of the relationship between IR and MDD. At the same time, they represent an epidemiology-based strategy for gaining insight into whether promising neuroscientific findings will translate into effective clinical approaches for treating MDD
Essays in behavioral market design
Keywords: Business.

In this dissertation, I study how centralized systems and platforms can improve their operational efficiency by taking into account the behavior of their users. To accomplish this, I combine two key elements: (1) understand users' behavior, and (2) identify sources of inefficiency and design solutions to address them. To better understand what drives user behavior, I combine techniques from behavioral operations and economics to derive models and hypotheses of how users make decisions. Then, I use tools from the econometrics literature to test these hypotheses and validate the proposed models. Finally, I combine this knowledge with tools from market design and operations to design and implement solutions that alleviate the inefficiencies identified in these markets. In the first chapter, I analyze the effect of increasing transparency in procurement platforms. The second chapter studies how the assortment composition and the history of past usage affect users' behavior in a two-sided market, and how we can take this into account to increase the number of matches generated. Finally, in the third chapter, I study the application behavior of students in the Chilean college admissions problem and propose an estimation procedure to account for their strategic behavior
Essays in empirical corporate finance
Keywords: Business.

In this thesis, I study two independent but closely related topics: the impact of liquid assets on corporate investments and bank deposit funding. In the first chapter, I examine the effect of a firm's liquidity holdings on its real investments and its impact on broader outcomes. I exploit a regulation-driven supply expansion of wealth management products (WMPs) that leads to an exogenous liquidity return increase accessible to Chinese firms. WMPs are deposit alternatives issued by commercial banks outside of the regulatory purview and are the dominant form of liquidity holdings by Chinese firms. I find that in response to the regulation, firms increase their liquidity holdings and sharply reduce capital and R & D expenditures. Using exogenous variation in banks' WMP supply induced by regulation, I argue that the effect of corporate liquidity holdings on real investments is causal and not driven by changes in firms' real investment opportunities. The reduction in real investments further leads to a decrease in firm-level TFP, patent application, primary business revenue, and employment. Exploiting regional economic growth in a difference-in-difference setting that uses the same regulatory shock suggests that the growth of corporate liquidity holdings has a negative impact on local economic outcomes. Cities more exposed to the WMP supply expansion exhibit slower capital and consumption growth. My findings suggest that a firm's liquidity holding decisions have a direct impact on its real investments and broader economic activities. In the second chapter, we demonstrate the passthrough of Treasury supply to deposit funding through bank market power. We show that an increase in Treasury supply leads to a net deposit outflow. At the same time, reliance on wholesale funding decreases. The effect is heterogeneous in nature - banks in more competitive markets experience larger outflows. The explanatory power of Treasury supply is not driven by monetary policy and bank-specific investment opportunities. Our empirical findings are rationalized with a model of imperfect deposit competition. Consistent with "The Deposits Channel of Monetary Policy", the model and empirics predict the opposite effect for Fed Fund rate hikes: there is a larger response in less competitive markets. Our results also shed light on the effect of the Reverse Repurchase (RRP) Facility on monetary policy passthrough
Essays in empirical financial accounting
Keywords: Business.

This thesis studies several topical areas in empirical financial accounting. In the first chapter, I investigate whether investors are willing to trade off wealth for societal benefits. This chapter is co-authored with my co-advisor David F. Larcker and is forthcoming in the Journal of Accounting and Economics. In the second chapter, I examine how an increase in tick size affects algorithmic trading, fundamental information acquisition, and the price discovery process around earnings announcements. This chapter is co-authored with my co-advisor Charles M.C. Lee and is forthcoming in The Accounting Review. In the third chapter, I explore the growing market for startup employee equity using proprietary data from one of the largest of these marketplaces. This chapter is under revision for submission to a top accounting or finance journal
Essays in financial economics
Keywords: Business.

This thesis consists of three essays. The first essay, which is joint work with Steve Grenadier, develops a theoretical model of a firm's optimal capital structure decision in a framework in which it may later choose to enter either Chapter 11 reorganization or Chapter 7 liquidation. In the second essay, which is joint work with Darrell Duffie, we show in the context of a theoretical model that the now-common practice of size discovery detracts from overall financial market efficiency. In the third essay, I show that creditors lose billions of dollars every year because firms that should emerge from Chapter 11 bankruptcy are frequently liquidated instead
Essays in housing and experimentation
Keywords: Economics.

This dissertation comprises of two chapters related to the effects of displacement due to foreclosure and firm entry and one chapter related to cluster-randomized experiments. In the first chapter, I show that the non-pecuniary costs of foreclosures are mainly borne by owners, while landlords suffer only financial costs and renters do not suffer much at all. In the second chapter, I test whether large firm entries can induce gentrification and find that on average, low-skilled incumbent renters have slightly negative to neutral outcomes while low-skilled owners have neutral to positive outcomes. In the third chapter, I examine issues that must be considered when running large scale parallel experiments at the individual and cluster levels of randomization
Essays in labor economics
Keywords: Economics.

This dissertation focuses on topics in labor economics. The first chapter analyzes whether female executives reduce gender gaps in establishments. Using matched employer-employee data from Germany, I compare establishments with male to female executive changes to those with male to male changes. I estimate that female executives increase female employment shares by 14 percent (3.4ppt) and female earnings ratios by 5 percent (4ppt). Using survey data administered by the German Federal Employment Agency, I find no evidence of female executives changing operational working hours, providing greater childcare assistance or implementing policies to promote gender equality. Overall, I conclude female executives do reduce gender gaps within establishments. The second chapter analyzes the labor market consequences of co-location problems dual career couples face. Using the Current Population Survey, I document that married individuals are less likely to move, both within and across states. In the second part of the paper, I analyze responses to exogenous shocks that prompt migration. In particular I analyze the out-migration responses to unemployment shocks to individuals using the Panel Study of Income Dynamics. I find that single individuals are significantly more likely to move out of their states following a negative employment shock, in comparison to individuals with partners. The third and final chapter analyzes how access to roads and highways have improved agricultural household's abilities to cope with local productivity shocks. In joint work with Yiming He, we build a theoretical model with precise empirical predictions; household's equilibrium employment in agricultural and non-agriculture should respond more to shocks when located closer to roads. The changes in wages on the other hand will be smaller. These empirical predictions are tested with a difference-in-difference model
Essays in macro-finance
Keywords: economics) degree supervisor.
Economics.

This dissertation analyzes various aspects of financial markets and fiscal policy. The first chapter, Public Employee Pensions and Municipal Insolvency, studies how municipal governments jointly manage spending, credit market borrowing, and a public employee pension system. I model governments as levered investors who must meet non-defaultable pension obligations and may value government spending more than citizens. I quantify the model using data on California cities, including a new record of fiscal emergencies, tax increases required to maintain essential city services. After the financial crisis depleted pension funds, cities engaged in excessive risk-taking: the fiscal emergency option encouraged gambling for resurrection that kept cities vulnerable to shocks well into the recovery. To correct this problem, a spending cap works better than a restriction on risk-taking. The second chapter, Subjective Cash Flow and Discount Rate Expectations, is co-authored with Stanford PhD student Ricardo De la O. This chapter focuses on a central question in finance: why do stock prices vary? Using survey forecasts, we find that cash flow growth expectations explain most movements in the S& P 500 price-dividend and price-earnings ratios, accounting for at least 93% and 63% of their variation. These expectations comove strongly with price ratios, even when price ratios do not predict future cash flow growth. In comparison, return expectations have low volatility and small comovement with price ratios. Short-term, rather than long-term, expectations account for most price ratio variation. We propose an asset pricing model with beliefs about earnings growth reversal that accurately replicates these cash flow growth expectations and dynamics. The third chapter, Sovereign Debt, Government Spending Cycles, and Back-loaded Pension Reforms, studies the effect of public pension obligations on a sovereign government's commitment to repaying debt. In the model, the government can renege on its pension promises but suffers a cost from losing the trust of households about future pensions. Large pension promises act as a commitment device for debt because they require the government to have regular access to credit markets. The government's decision to default is driven by its total obligations, not just its debt. Thus, there is a range of pension obligations large enough to act as a commitment device without raising total obligations to the point of default. This otherwise deterministic economy has an endogenous cycle in which periods of high spending and increasing debt are followed by periods of pension reform and debt reduction. The model successfully produces high debt in excess of 100% GDP without default and back-loaded pension cuts that match salient features of recent reforms in six EU nations