VictorJuiz/thesis huggingface dataset:
The role of long chain fatty acids in the Caenorhabditis elegans innate immune response [electronic resource]

Lipids have long been associated with beneficial and detrimental effects on health and disease. The influence of lipids on the immune system is both complex and diverse, but the mechanisms through which fats modulate innate immune function remain to be clarified. Using the Caenorhabditis elegans-Pseudomonas aeruginosa host-pathogen system, we have attempted to characterize the importance of lipid metabolism to infection responses mediated through the innate immune system. We present evidence for the specific manipulation of lipid metabolism in response to bacterial infection in C. elegans. Infection with Pseudomonas results in altered expression of genes involved in the synthesis of long-chain fatty acids (LCFAs) as well as the breakdown of fats through mitochondrial and peroxisomal beta-oxidation. We demonstrate that two 18-carbon LCFAs, gamma-linolenic acid (GLA) and stearidonic acid (SDA) are required for basal innate immunity in-vivo. Deficiencies in GLA and SDA result in increased susceptibility to bacterial infection, which is associated with reduced basal expression of a number of immune-specific genes. GLA and SDA are required to maintain basal activity of the p38 MAP kinase pathway, which plays important roles in protecting metazoan animals from infection and oxidative stress. Genetic analysis also allowed us to identify a monounsaturated fat, vaccenic acid (VA) that negatively influences C. elegans immune function through its effect on the DAF-2 insulin-like pathway. Decreases in VA levels result in increased resistance to pathogen infection and an associated increase in the expression of antimicrobial peptide and other immune-related genes. Decreased VA levels were also associated with increased nuclear localization of DAF-16, a FOXO transcriptional regulator of the insulin-like immune pathway in C. elegans. Interestingly, we found that the bacterial pathogen Pseudomonas aeruginosa takes advantage of the detrimental effects of VA to compromise the C. elegans host and make it more susceptible to infection. A Pseudomonas mutant defective in the production of VA is attenuated and is compromised in its ability to suppress host immune gene expression. Together we have demonstrated distinct roles for individual fatty acids in innate immune function and pathogen virulence. These results may provide novel avenues for the use of lipids as immune modulators and help identify new targets for potential antimicrobial treatments.

Advisor: Tan Man-Wah primary advisor. Thesis advisor
Chawla Ajay advisor. Thesis advisor
Jones Patricia P. advisor. Thesis advisor
Steinman Lawrence advisor. Thesis advisor
Runtime Automatic Speculative Parallelization of Sequential Programs [electronic resource]

This dissertation presents Runtime Automatic Speculative Parallelization (RASP), a technique for the dynamic extraction of speculative threads from a running application in a user-transparent fashion. By leveraging the idle cores in a CMP to analyze, optimize, and participate in the execution of a running sequential program, RASP enables a collection of simpler cores to achieve sequential performance on par with a significantly more complex core. In contrast to other systems for automatic speculative parallelization, RASP uses dynamic binary translation to optimize applications on-the-fly, without any need for recompilation or source code. RASP achieves these speedups without relying on special-purpose hardware support; RASP's dynamic profiling uses a clever variation on conventional performance-monitoring, while RASP's speculative execution relies on the same simple hardware support for speculation that has been proposed for simplifying parallel programming. On a simulated cluster of four in-order cores, RASP accelerates SPEC2006 integer benchmarks by an average of 49%, with promising results for scientific and multimedia workloads as well.

Keywords: Electrical Engineering
Advisor: Olukotun Oyekunle Ayinde primary advisor. Thesis advisor
Kozyrakis Christoforos
Rosenblum Mendel advisor. Thesis advisor
Security from location [electronic resource]

The emergence of the Internet and personal computers has led to an age of unprecedented information access. The proliferation of Internet connectivity, personal computers, and portable, high density data storage has put volumes of data at one's fingertips. While the spread of such technology has increased efficiency and knowledge, it has also made information theft easier and more damaging. One common expression of information theft is a data storage disk or equipment containing sensitive or valuable information. For example, the U.K. government lost computer disks that contain personal information on almost half of the country's population. The information includes names, addresses, insurance numbers, bank account details, etc. These emerging problems have made the field of information security grow significantly in recent years. This thesis develops a new means to provide more protection against information loss, named geo-security or location-based security. This new technology is well suited to help mitigate the above described data loss scenario. Precise location and time information can be used to restrict access of the system or equipment at certain locations and time frames. This study bridges the two fields of navigation and security, and provides experimental support for the concept using location information for security. This thesis designs a theoretical framework that provides a general analysis of geo-security, and quantifies the reliability and security of a geo-security system. The qualitative part of this analysis includes navigation signal definition, system design, performance standards, threat model and attack scenarios, and mitigation of the threats/attacks. The quantitative part of this analysis measures and quantifies location-dependent navigation parameters based on information theory, and evaluates the consistency, spatial decorrelation, and entropy of these parameters for a variety of relevant navigation systems. Next, this thesis demonstrates geo-security using Long Range Navigation (Loran) and Wi-Fi as case studies. Experiments were conducted to evaluate the performance based on the designed framework. They illustrate the trade space between permitting access to authorized users and denying access to attackers. Finally, error-tolerant algorithms, named fuzzy extractors, are developed to improve the availability and reliability of location-based security systems given the constraints of real-world navigation systems and signal propagation characteristics.

Keywords: Aeronautics and Astronautics
Advisor: Enge Per primary advisor. Thesis advisor
Lo Sherman Chih advisor. Thesis advisor
Powell J. David
Starting big [electronic resource] : the role of multi-word phrases in language learning and use

Why are children better language learners than adults despite being worse at other cognitive tasks? Previous accounts have focused on biological, cognitive or neural differences between children and adults. In this dissertation, I suggest the answer lies, at least in part, in the linguistic units that children and adults learn from and how those shape subsequent learning. I propose the Starting Big Hypothesis: children learn from units that are larger and less analyzed than the ones adults learn from. Children's early inventory includes multi-word fragments (e.g., give-it) and short multi-word utterances (e.g., I-don't-know, It's-my-turn). These multi-word units facilitate grammatical and lexical learning and are part of the native adult inventory as well. I argue that adults' prior knowledge and experience with language leads them to 'break language down' in a way that hinders the learning process. I explore three concrete predictions of this hypothesis 1) that children's morphological knowledge is facilitated in frequent sentence-frames 2) that multi-word phrases are part of the native adult lexicon, and 3) that L2 learning of grammatical gender will improve when learners are first exposed to larger chunks of language. I test these predictions using several experimental tasks: corpus studies of natural speech, elicited production with children, lexical decision, and artificial language learning in adults. The combined findings offer a novel perspective on the difficulty that adults experience in learning a second language. The findings enhance a usage-based view of first language learning that emphasizes the importance of multi-word phrases in the construction of grammar, and present evidence in support of an emergentist view of language where all linguistic experience (be it atomic or complex) is processed by the same cognitive mechanism.

Keywords: Linguistics
Advisor: Clark Eve V. primary advisor. Thesis advisor
Jurafsky Dan
Ramscar Michael advisor. Thesis advisor
Sumner Meghan advisor. Thesis advisor
Wasow Thomas advisor. Thesis advisor
State, market, and bureau-contracting in reform China [electronic resource]

Why and how has China succeeded as a developmental state despite a seemingly rents-ridden bureaucracy? Following conventional wisdom, "Weberian" bureaucracies are an institutional precondition for development, especially in interventionist states like China. However, my research finds that China's fast-growing economy has not been governed by a purely salaried civil service. Instead, Chinese bureaucracies still remain partially prebendal; at every level of government, each office systematically appropriates authority to generate income for itself. My study unravels the paradox of "developmentalism without Weberianness" by illuminating China's unique path of bureaucratic adaptation in the reform era -- labeled as bureau-contracting -- where contracting takes place within the state bureaucracy. In a bureau-contracting structure, the state at each level contracts the tasks of governance to its own bureaucracies, assigning them revenue-making privileges and property rights over income earned in exchange for services rendered. Contrasting previous emphases on the prevalence of illicit corruption in China, my study shows how and why bureaucracies in this context are actually authorized by the state to profit from public office. Specifically, I identify two factors that constrain arbitrary and excessively predatory behavior among Chinese bureaucracies: first, mechanisms of rents management, and second, the mediation of narrow departmental interests by local developmental incentives. In short, I argue that it is the combination of an incentive-compatible fiscal design and increasingly sophisticated instruments of oversight that have sustained an otherwise unorthodox structure of governance in China. In a phrase, bureau-contracting presents a high-powered but opportunistic alternative to the Weberian ideal-type. The Chinese experience suggests that "market-compatible" bureaucratic institutions need not necessarily conform to -- and may even diverge significantly -- from standard Western models, at least at early stages of development. My research draws on interviews with 165 cadres across different regions and governmental sectors, as well as statistical analysis of previously unavailable budget data.

Keywords: Political Science.
Advisor: Oi Jean C. (Jean Chun) primary advisor. Thesis advisor
Díaz Cayeros Alberto advisor. Thesis advisor
Laitin David D. advisor. Thesis advisor
Magaloni Beatriz advisor. Thesis advisor
Rodden Jonathan advisor. Thesis advisor
Studies of the cathode-electrolyte interface of solid oxide fuel cells [electronic resource]

Concerns about global climate change remain a significant driving force for research of energy conversion devices. Solid oxide fuel cells (SOFCs) are one such device. Several recent advances in SOFCs have focused on reducing the ohmic losses of the device, either through thinner electrolyte membranes, or higher ionic conductivity of the electrolyte. As these advances allow for the operation of SOFCs at lower temperatures, the major source of loss within these devices shifts to the interfaces. In particular, the activation losses at the cathode and cathode-electrolyte interface become the dominant bottleneck in the operation of SOFCs at lower temperatures. In this work, three studies on the cathode or cathode-electrolyte interface of SOFCs will be presented. Additionally, electrochemical impedance spectroscopy (EIS) is used as a tool for interpreting the types and amount of loss present in SOFCs under various fabrication and operational conditions. In the first study, thin films of LSCF, a mixed electronic-ionic conducting (MEIC) material, are deposited by pulsed laser deposition (PLD) and used as the cathode material for SOFCs. Research results indicate the presence of an optimal cathode thickness for maximum power performance, which is obtained by minimizing the sum of the electronic and ionic resistances of the cathode material. However, the results indicate the catalytic activity of this material severely limits SOFC performance at lower temperatures. In the second study, the effects of ion irradiation at the cathode-electrolyte interface of SOFCs are studied. In particular, the IV performance is observed as a function of irradiation energy for both xenon and sodium ions at a dose of 1E16 ions per square centimeter. Results indicate that xenon ion irradiation at low energy (70keV and below) produces an increase of more than 100% in the peak power density at 310°C, by reducing the activation losses of the SOFCs, while sodium irradiation produces little effect. Both xenon and sodium ion irradiation result in significantly worse performance at high irradiation energy (150 keV and above). Secondary ion mass spectrometry (SIMS) was used to verify the depth profile of the implanted ions, which compared favorably with simulations performed using a Kinetic Monte Carlo (KMC) model. Additionally, transmission electron microscopy (TEM) was used to visualize the damage created in the electrolyte substrates under various irradiation conditions. The final study looks at the role of electrolyte grain-boundaries at the cathode-electrolyte interface. Results from EIS measurements, quantum simulations, and SIMS analysis indicate that oxide ion incorporation from the cathode into the electrolyte is enhanced at grain boundaries of the electrolyte.

Keywords: Materials Science and Engineering
Advisor: Prinz F. B. primary advisor. Thesis advisor
Cui Yi
McIntyre Paul Cameron advisor. Thesis advisor
Taking Up, Getting Better and Crowding Out: Evaluating Local Effects of the California Healthy Kids Insurance Program

In this paper I use county level data from California to estimate the effects of the California Healthy Kids Insurance Program (CHKIP), an optional state county partnership that expands child eligibility for publicly provided health insurance. The paper is split into three sections: the first on the Political Economy of county selection into the program, the second on the program’s effect on child health outcomes, and the third on estimating the degree to which the program “crowds out” private insurance among children eligible for coverage. In the political economy section I find that the most important predictor of county selection into the program is the percentage of the population who are non-citizens. In the health outcomes section I find that CHKIP increases insurance coverage rates and decreases the likelihood that a child will delay medical care. In the crowd out section, I find no evidence for crowding out among children from families with incomes between %250 and %300 of the Federal Poverty Level, but do find evidence for small levels of crowding out among all children from families with incomes less than %300 of the Federal Poverty Level.

Keywords:  Department of Economics
Stanford Department of Economics
California Healthy Kids Insurance Program
public health insurance
children
health outcomes
private insurance
Federal Poverty Level
Thesis
Advisor: Bhattacharya Jayanta
Teacher Sorting and Own-Race Teacher Effects in Elementary School

I investigate “own-race teacher effects”—the extent that students benefit from having a teacher with the same racial background. Own-race teacher effects may justify recruitment of underrepresented groups in teaching and, in combination with peer effects, help to determine the optimal assignment of students to teachers. However, previous estimates of own-race teacher effects are confounded by the sorting of teachers across schools. Using administrative data from North Carolina public schools, I document that the quality of black teachers relative to white teachers increases with the school’s black enrollment share. To circumvent this endogenous sorting, I develop and estimate a novel teacher-level metric of own-race teacher effects based on teacher fixed effects. I find that own-race teacher effects are present for mathematics achievement, but significantly smaller than previous estimates.

Keywords:  Department of Economics
Stanford Department of Economics
race
teacher quality
teacher sorting
achievement gap
Thesis
Advisor: Hoxby Caroline
The Determinants of Child Labor and Schooling in the Philippines

The previous literature suggests that the determinants of child labor are largely country specific, indicating that any policies aimed at reducing child labor must look carefully at the causes of child labor in context. My thesis adds to the empirical work on child labor by investigating what household and community characteristics are most common among working children in the Philippines, using data collected by the International Labour Organization. I use a multinomial logit model with child activity as the dependent variable, where the three possible outcomes are work only, work and study, and study only. I find that poverty has a strong negative impact on the probability a child works full time or part time (relative to study only), especially in rural areas, as do the years of the household head’s education and having electricity and access to drinking water. Having a close biological relation to the head has a significantly positive effect on the probability of studying only for all groups of children, and especially for urban girls. The results also indicate that government programs like welfare and community organizations do little to reduce child labor, probably due to the lack of awareness among the majority of the populace.

Keywords:  Department of Economics
Stanford Department of Economics
multinomial logit
Filipino
poverty
income
household head
education
biological relation
household composition
community infrastructure
female headship
welfare
Thesis
Advisor: Jayachandran Seema
The Financial Aid Tax and Student Work Incentives

This paper investigates whether students account for the financial aid tax when making their decisions to work, and how much four-year university students know about how their financial aid is determined. This paper is divided into two parts. In the first part, I use the NPSAS:2000 data to determine if students respond to the financial aid tax structure by bunching below the point where the tax comes into effect. I find that they do not. In the second part, I survey Stanford undergraduate students on how the financial aid tax has influenced their decisions to work and save. Difference in differences analysis suggests that removing the tax would increase the probability that a student would earn in the tax paying range by 22 percent with a standard error of 12.6 percent. Finally, I suggest reforms that universities could make to improve the financial aid system. These reforms include educating students on how their financial aid is determined, replacing the single 50 percent marginal tax rate on student earnings with a progressive structure similar to that on parent earnings, and allowing low-income students a larger tax exemption.

Keywords:  Department of Economics
Stanford Department of Economics
Financial Aid
Higher Education
Tax Salience
Thesis
Advisor: Shoven John B.
The Impact of Mobile Phones on the Status of Women in India

Mobile phones have grown at an extraordinary rate throughout the developing world in recent years. They are potentially an invaluable economic asset to the poor and an important tool for strengthening social ties. Mobile phones may also help women overcome physical boundaries, especially in places where they are separated from their support networks and bound within their husband’s social sphere. This paper examines the impact of mobile phones on the status of women in India. Using nation-wide cross-sectional data at the individual level, I build on Jensen and Oster’s model for measuring women’s status. I use domestic violence, decision-making autonomy, child preferences and economic independence as proxies for bargaining power and status of women in their household and society. I find that mobile phones significantly decrease both men and women’s tolerance for domestic violence, increase women’s autonomy in mobility and economic independence, but do not find significant effects on child preferences and other measures of autonomy. Where the effects are significant, they are also large and in some cases equivalent to more than five extra years of education. These results suggest that the Government of India and those of other countries should consider mobile phones as a policy instrument for empowering women.

Keywords:  Department of Economics
Stanford Department of Economics
mobile phones
gender inequality
domestic violence
autonomy
linear probability
probit
ordered probit
Thesis
Advisor: Jayachandran Seema
The Publication of Interest Rate Projections by the Central Banks of Norway and Sweden

The publication of interest rate projections by central banks, a central bank’s own quantitative estimate of future interest rate decisions, is the newest and most controversial method of increasing transparency. Economists and central bankers disagree over whether or not publishing projections help the central bank manage private sector expectations. This paper examines if publishing interest rate projections by the central banks of Norway and Sweden improves the private sector’s ability to predict future interest rates. I investigate the effect of publishing projections on the root mean square error of money market forward rates and on changes in rates in response to interest rate decisions by the central bank. Using a New Keynesian macroeconomic model, I show that publishing projections should improve predictability if publishing provides the market with a clearer signal of future actions by the central bank. However, the empirical evidence suggests the effect of publishing projections may be negligible because interest rates were already relatively predictable and projections from both central banks have performed poorly during the financial crisis.

Keywords:  Department of Economics
Stanford Department of Economics
Central bank communication
interest rate projections
Norges Bank
Riksbank
Thesis
Advisor: Taylor John B.