VictorJuiz/thesis huggingface dataset:
Geometric representations of W-algebras and applications to the quantum Langlands correspondence

Fix a reductive group G, and consider the affine W-algebra associated to a principal nilpotent element of the Lie algebra of G. We determine the block decomposition of its category of highest weight, i.e. positive energy, representations, and identify regular blocks with Whittaker sheaves on the affine flag variety of G. We also identify the latter category, under a mild hypothesis on the central charge, with Category O for the affinization of the Langlands dual Lie algebra at the dual central charge. The latter confirms a conjecture of Gaitsgory, and implies non-factorizably, a related conjecture of Gaitsgory and Lurie

Keywords: Mathematics.
Advisor: Bump Daniel
Yun Zhiwei
Vakil Ravi
Geophysical applications of sound : volcano infrasound and marine seismic sources

Acoustic waves are generated by a wide range of natural and artificial geophysical phenomena. By studying the acoustic signals, insight can be gained about the fundamental processes governing these phenomena. In this thesis I examine acoustic signals from two different sources; volcanic eruptions and pneumatic marine seismic sources. In Part I of this thesis I consider acoustic waves generated by volcanic activity. Volcanoes are prodigious sources of low frequency acoustic waves, which are termed infrasound as the signals are predominantly at frequencies below human hearing. Harmonic infrasound signals are observed at open-vent volcanoes and in Chapter 2 I develop a numerical model to demonstrate that these signals can be explained by acoustic resonance of the crater. In Chapter 3 I apply this model to the 2015 eruption of Villarrica (Chile) and show that the lava lake rose in the crater prior to the paroxysmal eruption. These two chapters illustrate the utility of monitoring infrasound resonant modes at open vent volcanoes and may aid in forecasting future eruptive activity. The majority of volcano infrasound studies assume linear wave propagation. However, volcanic eruptions are violent phenomena and there is increasing evidence of nonlinear wave phenomena, such as shock waves, during eruptive activity. In Chapter 4 I perform nonlinear computational aeroacoustic simulations of volcanic eruptions to explore the effect of nonlinear wave propagation and demonstrate that assuming linearity can result in overestimation of erupted fluxes for eruptions with high (supersonic) exit velocities. In Part II of this thesis I study pneumatic marine seismic sources, which are the predominant source used in marine seismic surveys. Pneumatic seismic sources are broadband sources that generate both geophysically useful low frequencies and high frequency noise that is harmful to marine life. In Chapter 5 I explore controls on the initial peak of a pneumatic seismic source signature. The initial peak is generated by the initial release of highly pressurized air into the water and is responsible for generating high frequency noise that can be environmentally damaging. In Chapter 6 I present numerical simulations of a novel pneumatic seismic source, called the Tuned Pulse Source, and demonstrate that this source will generate increased low frequency content. In Chapter 7 I digress slightly to compare marine seismic signals with the low frequency calls of fin whales and speculate on possible mechanisms of low frequency sound generation in whales

Keywords: Geophysics.
Advisor: Dunham Eric 
Segall Paul
Suckale Jenny
George Padmore's African Revolution: Reviving Marxism-Leninism in the 20th Century Pan-African Tradition

This thesis is an intellectual biography of the Trinidadian anti-colonialist George Padmore (1903-1959), focusing on his life between 1927 and 1945. Drawing upon archival research in London, Moscow, and New York, it traces how Padmore's early conversion to Marxism as a member of the Communist International influenced his thinking on how to achieve African independence. Throughout the 1930s and 40s, Padmore was a central figure of Pan-African organizing in the Anglophone world and worked alongside black revolutionaries such as C.L.R. James, Jomo Kenyatta, and Kwame Nkrumah.

Keywords:  Department of History
George Padmore
Pan-Africanism
Black Britain
International African Service Bureau
Pan-African Congress
Black Marxism
Black Radical Tradition
International Trade Union Committee of Negro Workers
Stanford University History Department
Thesis
Advisor: Campbell James T.
Satia Priya
Giant magnetoresistive nanosensor analysis of circulating tumor DNA for therapy response monitoring and early detection of cancer

In the era of precision medicine, molecular subtyping of non--small cell lung cancer (NSCLC) has revolutionized therapeutics tailored to individual actionable mutations, particularly the use of tyro- sine kinase inhibitors (TKIs) for Epidermal Growth Factor Receptor (EGFR) mutations. However, efficient therapy selection remains challenging for some patients, and it is estimated that 20% of lung cancer patients begin therapy prior to EGFR testing. Common reasons for lack of molecular testing include insufficient tissue biopsy or inability to biopsy certain patients, and long turnaround times to results. Clearly, new technologies that are rapid, cost--effective, and highly sensitive are needed for effective companion diagnostics. This thesis outlines the development and clinical translation of a blood--based circulating tumor (ct) DNA EGFR genotyping assay using giant magnetoresistive (GMR) nanosensors as an alternative for therapy selection and response monitoring. This GMR as- say achieved analytical sensitivities of 0.01% mutant allelic fraction for 3 common "hot spot" EGFR mutations, equivalent to detecting 1 mutant allele in a background of 10,000 wild--type alleles. In a clinical study of therapy selection and response monitoring of metastatic NSCLC patients, the assay achieved high sensitivity and specificity (AUC > 0.95) and was able to accurately predict therapy response after just 2 weeks. This represents a vast improvement compared to the current clinical standard of radiographic (CT) assessment after 2--3 months, which can be a harmful delay for patients who do not respond to targeted therapy and need immediate changes in therapeutic regimen. GMR sensors were also utilized for the early detection of colorectal cancer (CRC). While CRC diagnosis in Stage I is associated with a 90% 5--year survival rate, common screening methods such as colonoscopy or fecal testing are underutilized, resulting in a majority of CRC patients diagnosed at later stages. A non--invasive blood--based ctDNA test with GMR sensors could aid in screening efforts, with methylation biomarkers indicated for improved early cancer detection compared to mu- tations. This thesis also details the technology development of integrating methylation--specific PCR with high resolution melt (HRM) analysis on GMR sensors for quantifying methylation density. The technology was first optimized in a melanoma cell line model, and then extended to a multiplexed panel of 4 putative biomarkers of early CRC. This assay achieved analytical sensitivities of 0.01% methylated allelic fraction for 3 of 4 markers, and was validated in 2 late stage CRC patient samples

Keywords: Chemistry.
Advisor: Wang Shan X. 
Bertozzi Carolyn R.
Karunadasa Hemamala
Glial Priming in Neocortical Circuit Maturation

The combinatorial effects of sequential neuroimmune insults have been implicated in the pathogenesis of many neurological disorders. To explore how prenatal and early postnatal innate immune activation impacts the developmental establishment of neural networks, we developed a neuron-astrocyte coculture model of virus-like neuroinflammatory challenges and used calcium imaging with the GCaMP reporter to document cell- and ensemble-level activity patterns over time. Neurons co-cultured on naïve astrocytes provided baseline measures of activity and synchrony within neuronal ensembles. Interferon gamma (IFNγ) exposure measurably accelerated the acquisition of synchrony within ensembles co-cultured with serum-preactivated, but not naïve, astrocytes. Machine learning analyses of neuronal synchrony data identified distinct, immune exposure-dependent patterns of maturation which are sufficient to predict the immune exposure history of cells based on their signaling properties with over 90% accuracy. Combined exposure to IFNγ and primed astrocytes was also correlated with increases in the ratio of protein expression levels of chloride symporters KCC2 and NKCC1, suggestive of accelerated neuronal maturation in dual hit-challenged cells. Collectively, these findings suggest that early-life inflammatory exposures can prime astrocytes to respond differently to later immune events than naïve astrocytes and identify one potential mechanism through which immune challenges can alter key neural network milestones in perinatal development.

Keywords:  Department of Biology
Biology
Neurobiology
Neuroscience
Astrocyte
Glia
Neural Circuit
Neurodevelopment
Neuroinflammation
Neuroimmunity
Thesis
Advisor: Palmer Theo D.
Heller H. Craig
Global changes in the structural dimensions of national education systems : high stakes exams, tracking, and national assessments, 1960-2010

My dissertation examines global changes in several fundamental structural dimensions of national education systems that shape social stratification and the quality of a country's education: national high stakes examinations, tracking, and assessment tests. To analyze these changes, I draw on a newly constructed global panel dataset of 140 countries from 1960 to 2010. Using panel data and event history models, I argue that worldwide shifts in conceptions of education after World War II, toward universal and egalitarian norms of educational access, led to a decline in the use of high stakes exams and tracking at lower levels of the educational process; they also contributed to the dramatic expansion of national assessment testing in countries around the world. These changes have been shaped by the globalization of democratic norms, the rise of global social movements like "Education for All, " and international non-governmental organizations that shape and disseminate world societal discourse on education. My findings have broader implications for understanding: (a) the role of macro-level cultural/institutional processes in shaping educational stratification, (b) how competing conceptions of education, as a mechanism for both spreading equality and allocating individuals to unequal roles, create tensions in the way that nation-states construct their education systems, and (c) theoretical tensions between cultural processes of rationalization and expanding notions of individual personhood

Keywords: Sociology.
Advisor: Meyer John W. 
Jackson Michelle Victoria
Ramirez Francisco O. 
Schofer Evan
Global health and the environment : studies on air pollution and reproductive health policies

Air pollution and reproductive health access are two of the world's most pressing global health problems. My dissertation examines these issues through four chapters. Air pollution is currently the biggest environmental cause of disease and premature death globally and 92% of air pollution related deaths occur in low-income countries. Air pollution has been rising in many low-income countries as a result of rapid economic development and urbanization. The first two chapters examine the case of brick manufacturing in Bangladesh, one of the country's most polluting industries. First, I use a novel approach for identifying brick kilns in satellite imagery and empirically document the extent to which people are exposed to the industry and the state of regulatory compliance. In my second chapter, I demonstrate the consequences of regulatory failures in terms of air pollution and health impacts for people living in close proximity to brick manufacturing. Turning to the other part of my dissertation, abortion access is being addressed worldwide, with examples of both restrictions and expansions. While the policy debate is often dominated by moral and ethical arguments, much less attention is paid to the impacts on women's health and well-being. The second two chapters of my dissertation examine the implications of two different policies that affect reproductive health access. First, I study the effects of an Israeli policy that expanded access to a subsidy covering the full cost of an abortion. Using unique administrative data, I show the immediate impacts on fertility, but also examine the implications for human capital investment and labor market outcomes. In the final chapter of my dissertation, I extend an analysis of the U.S. Mexico City Policy, studying the impacts on abortion, contraceptive use, and pregnancies in a sample of 26 sub-Saharan African countries over 20 years and three transitions of the imposition of the policy. Across these four chapters, my dissertation demonstrates both regulatory failures and unintended policy consequences, but also highlights opportunities for evidence-based strategies to reduce kiln pollution and improve maternal health and socioeconomic outcomes

Advisor: Luby Stephen
Miller Grant
Bendavid Eran
Burke Marshall
Governance under Xi: Party Leadership and Centralized Decision-Making in the Xi Jinping Era

Under Xi Jinping, China saw the increased prominence of the role of the Party in governance as well as a trend towards greater centralization of power. How we interpret these two phenomenon has implications on our reading of China's trajectory going forward. This thesis seeks to explore these two themes from the lens of the CCP, providing an analysis on the larger drivers behind the changes.

Keywords:  Stanford Global Studies
East Asian Studies
Stanford Global Studies
Asia
Politics
Xi Jinping
Centralization
Party
Thesis
Advisor: Miller Alice Lyman
Grasping the Heavenly Vault and the Vessel in Raku Kichizaemon XV's Chawanya

Should I stage a coup d’etat, or be more je ne sais quoi? Am I just a pendulum swinging from frictionless pivots, and like earth to the firmament and the Chawanya, Raku Kichizaemon XV, to the flames, where do I fix my limits?

Keywords:  Stanford Global Studies
Raku
Raku ware
Raku-yaki
Raku Jikinyu XV
Raku Jikinyu
Raku Kichizaemon XV
Raku Museum
Sagawa Art Museum
Kuta
Tenmon
Tianwen
Chojiro
tea bowls
chawan
youth
coming of age
tea ceremony
chanoyu
chawanya
Stanford Global Studies
Center for East Asian Studies
Thesis
Advisor: Miller Alice Lyman
Ground-satellite optical two-way time and frequency transfer through atmospheric turbulence

Ground-satellite optical time and frequency transfer links will be an essential part of future global clock networks. New time transfer links are needed to support the comparison of state-of-the-art optical lattice clocks in space, and at intercontinental distances across the Earth. New satellite optical links, leveraging optical communications technology, can enable applications in global timekeeping, precision navigation, tests of General Relativity, mapping of terrestrial coordinate frames, and more. This dissertation applies the theory of optical propagation through atmospheric turbulence to the ground-satellite link geometry, for the purpose of analyzing the timing and frequency instability of two-way ground-satellite optical links

Keywords: Electrical Engineering.
Advisor: Hollberg Leo (Leo William)
Kahn Joseph M. (Joseph Mardell) 
Macintosh Bruce
Pauly John (John M.)
Guns, Germs, And Alleles: Analyzing Lone Insider Bioweapons Threats

Prior to the 21st century, biological weapons were considered largely the purview of state bioweapons programs. As the life sciences quickly advanced into the 2000s, including an exponential drop in the cost of DNA sequencing and synthesis, there was increasing concern that weaponizing pathogens may become within reach for non-state actors. The ability to synthesize whole viruses, first demonstrated in 2002, stoked concern that scientists could synthesize agents with pandemic potential that could be used in a mass-casualty attack. Lone insiders in biological laboratories, who have technical training and access to laboratory equipment, were considered a particular threat. Despite these concerns, why have no mass-casualty attacks using pathogens been perpetrated by lone insiders? This thesis considers two factors: the historical capabilities of lone insiders to acquire pandemic potential viruses, and their motivations to perpetrate mass-casualty attacks. First, I show that the malicious acts historically perpetrated by lone insiders are bio-crimes rather than bioterrorist acts, and therefore largely not intent on inflicting mass casualties. Conversely, transnational groups that may have this intent have not sought to recruit insiders in biological laboratories. However, professional and financial gain can be powerful motivators for lone insiders and may still lead to event that can incur large-scale harm. Second, drawing on bibliometric data from synthetic virology papers, I argue that the historical threshold for capability required to synthesize viruses has been prohibitory to those who were not early adopters or innovators in the field synthetic virology, and so there is a small pool of concerning actors that make such attacks less likely, although this is changing as capabilities rapidly diffuse. By more fully understanding the threat of mass-casualty attacks posed by lone insiders and developing better indicators of rapidly changing capabilities, policy makers and research institutions can work to assess this threat and position themselves to prevent and prepare for biological threats.

Keywords:  Center for International Security and Cooperation
Center for International Security and Cooperation
bioterrorism
lone insider threats
Thesis
Advisor: Stearns Tim
Palmer Megan J.
Habitat Assessment Using A Coupled Surface Water-Groundwater Flow and Heat Exchange Model for the Braided Ngaruroro River in Hawke's Bay, New Zealand

Braided rivers are highly biodiverse environments owing to the wide variety of hydraulic habitats that they possess. However, the natural division of flow during braiding leads to low discharge and overheating in braids when subjected to reduced summertime flows and high temperatures. In the absence of anthropogenic disturbances, these rivers mitigate extreme temperatures through an intimate subsurface network of groundwater flow, particularly in high conductivity beds and aquifers like that of the Lower Ngaruroro River in Hawke’s Bay, New Zealand. Through a feedback cycle of infiltration and groundwater spring discharge, the river is able to maintain ecologically favorable river temperatures, even in easily heated, low-flow braids. In this study, groundwater abstraction was shown to diminish the river’s self-cooling capabilities. Not all groundwater-fed braids were found to be equally vulnerable to such decreases – in fact, some zones of thermal refugia were resilient against even extreme levels of groundwater abstraction (causing up to 75% losses in river discharge). In contrast, surface water abstraction was found to promote cooler temperatures in localized, spring-fed thermal refugia, albeit at the expense of reach-wide hydraulic habitat suitability. To gauge the impacts of abstraction on the ecological community, the habitat preferences of two sensitive but valuable species native to the Ngaruroro River - the mayfly (sp. Deleatidium) and torrentfish (sp. Cheimarrichthys fosteri) - were used in the formulation of composite habitat suitability indices. While the temperature-sensitive mayfly experienced a reduction in habitat quality during groundwater abstraction due to increased water temperatures, the more selective hydraulic preferences of the torrentfish resulted in a steeper decline in its high quality habitats during both surface water and groundwater abstraction. Under current climate conditions, optimizing for species hydraulic preferences alone appeared to provide the best outcome for the Lower Ngaruroro River’s ecological community.

Keywords:  Earth System Science
School of Earth Energy &amp; Environmental Sciences
braided river
groundwater
habitat
Thesis
Advisor: Gorelick Steven M.
Freyberg David L.
Hardware acceleration for fluid flow simulation

Over the past 35 years, the speed of fluid flow simulations reflected the increase in transistor densities as predicted by Moore's law. Recent improvements in compute capability, however, highlight a slowing trend: difficulties in extracting fine-grain parallelism, the divergence between flops and memory bandwidth, and the additional burden on solver developers who are now expected to manage complex memory hierarchies explicitly are all contributing factors. Yet the speed demands on fluid simulations for applications that require multiple evaluations including design exploration and optimization, uncertainty quantification, AI/ML, reduced-order modeling, digital twins, etc., are continuing to increase. In this dissertation we focus on the study of a possible alternative to bridge the gap between the predicted shortcomings in Moore's law and the requirements of many of these applications. We discuss the possibility of developing application-specific integrated circuits (ASIC) to solve the equations of fluid flow using a Lattice-Boltzmann Method (LBM) approach. We begin with a brief discussion of the LBM approach, focused on computation and communication requirements, and compare the relative performance and merits of implementations on GPUs, FPGAs, and ASIC. Preliminary conclusions indicate that performance improvements of 74x, relative to a state-of-the-art GPU, may be possible using and ASIC with feature sizes of 7 nm or smaller

Keywords: Electrical Engineering.
Advisor: Alonso Juan José
Horowitz Mark (Mark Alan)
Murmann Boris