VictorJuiz/thesis huggingface dataset:
Navigating climate change : he role of politics in youth discourse and scientific reasoning
Keywords: Education.

Human-driven climate change remains divisive in the US, where skepticism of the scientific consensus is associated with political conservativeness. However, how politics affect youth perceptions of climate change has been studied only minimally. This dissertation deepens our understanding of the ways in which political views influence US youths' scientific reasoning about climate change. Study #1 used mixed methods to analyze the results of an individually randomized trial involving 357 participants in grades 9-11. Findings demonstrated the value of teaching mechanistic understandings of climate change, yet also showed the influence of worldview on receptivity to climate change for adolescents, as well as complex interactions between quantitative reasoning and worldview. Study #2 examined the intersection of science, emotion, and politics in youth writing about climate change, with an analysis of letters written by 350 teenagers across the United States during the lead up to the 2016 Presidential election. Using a mixed-methods approach to analysis, this study identified in these letters three distinct discourses, or ways of discussing climate change: a solution-oriented discourse, a climate politics discourse, and a discourse of doom. This analysis also demonstrates the politicization of climate change for some youth in the US. Study #3 asked about science learning that occurred in a 9th grade classroom in moments when political aspects of climate change emerged through discourse. With sociocultural theory as a conceptual lens, this study used discourse analysis to show evidence for productive disciplinary engagement (PDE) around knowledge of the political dimensions of climate change. It also described moments in which students drew on their own personal political frameworks to navigate issues of science
Nehruvian Socialism, a Fine Balance: Reconciling Economic Planning and Democracy in Modern India (1947-64)
Keywords: Vibhav Mariwala
Department of History
Stanford University
Jawaharlal Nehru
Democracy
Socialism
Planning
Keynes
Soviet
Five-Year Plan
The Bombay Plan
Modernity
Constitution
Political Economy
Thesis

This work examines the origins of post-colonial India's political economy, and how centralised state planning was reconciled with India's democratic constitution. By analysing the work of Jawaharlal Nehru, India's first Prime Minister, this thesis shows that national unity and poverty were two overarching aims that guided India's political economy in the initial years after independence. After examining the intellectual history of state intervention and economic planning from the 1920s-1940s in the USA, USSR and Europe, the thesis explores how planning was conceived of in India. It also analyses the perspectives of Indian businesses and finally sees how planning was implemented during Nehru's rule from 1947-64 in the form of Five-Year Plans.
Neither blank slate nor set in stone : cultural behaviors of organizational newcomers
Keywords: Business.

This thesis probes the causes and consequences of cultural behavior of new organizational members - newcomers. Chapter 1 models and simulates the effect of inter-organizational mobility on cultural diversity in organizational populations, demonstrating how culture within organizations may be shaped by the behavior of other organizations via culture carriers. Chapter 2 leverages modern tools from computational linguistics to analyze when individuals switch cultural codes following an organizational merger, highlighting the interacting effects of social status and adaptability. Chapter 3 builds on the data and methods developed in Chapter 2 to examine the network conditions that shape emergent cultural change, finding that individuals in brokerage positions are more likely to become sources, or vanguards, of future culture. Collectively, these chapters draw attention to organizational structures and boundaries as key sources of cultural variation and change
Nemt altiu maer für niuwe : Wolfram von Eschenbach and the Arabic subtext of Latin Europe from the twelfth century
Keywords: German Studies.

In my dissertation I analyze Wolframs von Eschenbach's Willehalm and Parzival with regards to the tangible appropriation of elements of Saracen culture. I explore the phenomenon in order to derive through literary analysis a model which which to describe the complex engagement with Arabic Culture in Latin during the twelfth and thirteenth centuries
Neural circuitry of self-self and self-non-self interaction
Keywords: Bioengineering.

Humans typically experience life as a single self that is tightly associated with a body, conscious awareness, sense of agency, and presence in reality. Indeed, self is an ubiquitous form of human mental experience, and the recognition of a single self within each person influences the way we interact with each other, participate in political, legal, medical, cultural systems, raise children, and relate to death. In this dissertation, I describe how early insights during my first rotation project in the peripheral nervous system inspired experiments of a complex condition called dissociation in which the self is perceived to be disconnected from one's self. Appreciating that humans and social animals brains not only generate self and self-self interaction, but also model or and attend to non-self selfs, I present studies of innate visual animacy attention in rodents. Together, these three efforts investigate neural circuitry of self-self and self-non-self interaction
Neural population dynamics underlying motor learning
Keywords: Bioengineering.

Several organisms often demonstrate the ability to produce highly adaptable and increasingly sophisticated movements. The computations required to produce even simple arm movements, e.g., reaching for a coffee cup, involve generating complex time varying patterns of neural activity. Learning poses an even greater challenge: the brain must somehow select a set of neural commands, from billions of possible activity patterns, that best help the organism achieve its movement objectives. Consider a common scenario where a subject learns a motor task in one context, and now wishes to perform the same task in a very different context. Certainly, in some cases this is possible. What are those cases? What is the neural mechanism that facilitates this transfer of learning? We developed a ``covert learning" paradigm whereby Rhesus monkeys can perform the same visuomotor learning task either overtly using arm movements, or covertly using a brain-machine interface. In the covert context, no overt movements can be made, and thus monkeys learn to generate patterns of neural activity that drive the brain-machine interface to perform the task. Using this paradigm, we demonstrated that learning can indeed transfer across contexts in order to improve overt behavior. We studied the neural activity in premotor and primary motor cortex during transfer learning at a population level. Intriguingly, we discovered that a key ingredient driving transfer is a shared neural substrate consisting of neural activity during motor preparation (this is known as preparatory activity or the preparatory state). Even on the single-trial level, behavioral improvements due to visuomotor learning are accompanied with systematic changes to the motor cortical preparatory state. Standard theories of visuomotor learning suggest that a trial-by-trial learning process performs computations based on an efference copy of the outgoing motor command, and sensory feedback during motor execution. These computations result in an update, which improves the behavior on subsequent trials. Our results suggest that this update occurs (at minimum) during motor preparation. Finally, through microstimulation experiments, we established the first causal link between motor preparation and visuomotor learning. Concretely, we found that neural activity during motor preparation causally interacts with the update computations of a trial-by-trial learning process. Disrupting preparatory activity does not affect the current trial, but instead influences the update computation in a fashion that manifests as disruption to learning on subsequent trials. More generally, these experiments reveal that the learning process (a) has access to the preparatory state, (b) the ability to assess how good the current preparatory state is, and (c) the ability to influence the preparatory state on both current and future trials. Taken together, this thesis reveals that neural activity before the onset of movement, or even in the absence of movement altogether, could play a fundamental role in the algorithm underlying the neural control of movement
A new genetic model organism for primate-specific cardiac function and disease
Keywords: Biochemistry.

Due to differences in cardiac structure and function, it has become increasingly clear that many aspects of cardiovascular anatomy, physiology, biochemistry, and disease are not well modeled in mice. This has spurred a search for new model organisms with the practical advantages of mice but that more closely mimic human biology and disease. This study examines mouse lemur (Microcebus species) -- the world's smallest, most prolific, and among the most abundant non-human primates -- and the cheapest and easiest to maintain, as such a model. Little is known of lemur cardiovascular physiology, cell types, or pathology. This thesis describes the characterization of normal cardiac anatomy and histology, and baseline values for heart rate, cholesterol/lipids, and cardiac waveform by electrocardiography (ECG). It also describes the development of a single cell RNA-sequencing and analysis pipeline for Microcebus murinus that provided genome-wide expression profiles of thousands of cardiac cells. Computational clustering of these transcriptomic profiles, and analysis of cluster-specific expression patterns of mouse lemur orthologues of canonical markers of human and mouse cardiac cell types, identified all major and many minor cardiac cell types in mouse lemur, including several exceedingly rare cell types. To begin to identify cardiac diseases in mouse lemur, a portable 3-lead ECG monitoring device was used to screen ~300 laboratory Microcebus murinus mouse lemurs and ~100 wild Microcebus rufus and a new species of mouse lemurs in Ranomafana National Park in Madagascar. This identified 20 naturally-occurring ECG variants in 170 affected lab and wild animals, with all identified variants resembling known human ECG variants including 8 major cardiac arrhythmias and pathologies plus 7 additional potentially pathological variants. The screen uncovered the first cases of heart disease in lemurs. One is atrial fibrillation, the most common arrhythmia in humans. Another is mouse lemur sick sinus syndrome (SSS), with episodic bradycardia resembling human SSS, whose familial forms arise from mutations in cardiac ion channel genes HCN4 or SCN5A. Both of these mouse lemur pathologic arrythmias show familial clustering, consistent with a genetic origin. The family pedigrees can now be used to determine the inheritance pattern of these diseases, map the underlying disease genes, and sequence the disease loci to identify the causative mutation. The results establish the mouse lemur as the first systematic, high-throughput primate genetic model for cardiovascular physiology and disease, and reveal human-like cardiac cell types and diseases. The approach uncovered naturally-occurring cardiac diseases that have not been found in mice. Furthermore, the strategy outlined here serves as a paradigm for identifying and studying physiological and behavioral traits and diseases beyond the cardiovascular system in this new primate genetic model organism
New mechanisms of ionizing radiation detection for time-of-flight positron emission tomography (ToF-PET) : modulation of optical properties and Cherenkov luminescence
Keywords: Electrical Engineering.

Positron emission tomography (PET) is a non-invasive imaging technology used every day throughout the world that enables visualization and quantification of the molecular signatures of disease in living subjects in the clinic as well as in biological research. Photon time-of-flight (ToF) capability is a critical and highly desirable feature for PET since it enables substantial signal amplification that enhances signal-to-noise ratio (SNR) in reconstructed images, which can be exploited for better lesion visualization and quantification, or to reduce patient injected dose and/or shorten PET scan duration. This ToF enhancement is determined by the PET system's coincidence time resolution (CTR). With a goal to drastically improve CTR over the conventional scintillation-based detection approach used in all existing PET systems, I have explored a new mechanism of ionizing radiation detection using ionization-induced optical property modulations. I have also studied the Cherenkov luminescence emission in novel materials. I have performed theoretical simulations showing that pulse-counting annihilation photon detection as required in PET is feasible by detecting ionization-induced optical property modulations. The lower limit on the achievable CTR for this technique is estimated to be a few picoseconds. I have developed the first proof-of-concept experimental arrangement that shows that the mechanism of optical property modulation (e.g., small changes in refractive index) can be used to detect the effects of ionizing photons. With efforts to amplify the ionization-induced optical property modulation signal and improve the detection sensitivity of experimental setups, I have shown that individual ionizing particle detection can be achieved. I have also performed time correlation experiments and described a promising spectral encoding readout method, which is not limited by electronic readout jitter, and demonstrates the potential for optical readout of ionizing photon interactions to achieve even femtosecond scale timing resolution. In addition, I have studied the timing capability of detecting Cherenkov luminescence in new perovskite bulk crystals as potential ionizing radiation detectors for PET. With outstanding energy resolution, relatively low cost, and an easy crystal growth process in addition to excellent CTR, these perovskite crystals are promising candidates for PET detectors
New methods for variable importance testing with applications to genetic studies
Keywords: Statistics.

The objective of this thesis is to develop new practical and principled statistical methodology for the analysis of genome-wide association data, in order to identify, as precisely as possible, the genetic variants that affect complex phenotypes. This problem can be stated as one of testing multiple hypotheses of conditional independence between many possible explanatory variables and a response of interest, within a high-dimensional non-parametric regression setting. This dissertation builds upon previous work on knockoffs, which provides a general framework for addressing such variable importance testing problems. In particular, we study how to generate valid knockoffs for genetic variants, while taking into account the particular structure of these data and the hidden Markov models developed by geneticists to describe their distribution. As a result, we can obtain an effective and statistically rigorous tool for genetic mapping that controls the false discovery rate under minimal assumptions, while overcoming many of the limitations of the existing state-of-the-art methods. Extensive numerical experiments with genetic data confirm the empirical validity and effectiveness of our method, while applications to the analysis of large data sets lead to many new discoveries
New problems and perspectives on learning with limited memory
Keywords: Electrical Engineering.

This thesis explores various new questions around the role of memory in learning. These questions are motivated by the scale of modern machine learning models and datasets which have made memory a bottleneck in many practical settings, but at their core they are fundamental questions about the interaction of data, computation and learning. Following are some of the questions we consider: 1) What role does memory play in learning and optimization? Are there inherent trade-offs between the amount of memory required for learning or optimization, and the amount of data or computation required? 2) How do we learn concepts and make accurate predictions with small memory? When can we solve learning problems on high-dimensional data with memory much less than the dimensionality of the data? 3) How do we consolidate and reference memories to make predictions about future observations? When is it necessary to leverage long-term memory of observations from the distant past to make accurate predictions? In this thesis, we distill down these questions and formalize them to enable a systematic study. We undertake both a theoretical and an experimental study---showing new inherent limitations on learning with limited memory, and also developing new algorithms which can solve many problems of interest with a small memory footprint in practice. These results illuminate new perspectives on the role of memory in learning, and also suggest several directions of future research
News in the Age of New Media: The Changing Meaning of News as told by the Story of CNN
Keywords:  Fisher Family Honors Program in Democracy
Stanford University
media
disinformation
cnn
history
Thesis

This thesis examines the meaning of “news” in the age of new media. Contemporary scholarship across communication studies, political science and computer science draws attention to numerous problems impacting the state of media today: disinformation, political polarization, and declining public trust describe just a few of these conversations. At the foundation of all of these conversations lies a deceptively simple question: what does “media” mean today in the first place? To answer this question, my thesis traces the changing meaning of news in the age of new media through the story of the Cable News Network (CNN). As the first international 24-hour cable news network, CNN embodies many elements of new media. In my thesis, CNN provides a window into 1) the rapid technological, cultural and institutional developments that were foundational to emergence of new media and 2) the changing meaning of journalism in the era of new media. To contextualize the emergence of new media, I examine the technological innovation of satellite technology; the cultural shift that increased public desire for news; and the institutional changes in the news industry marked by the Federal Communications Commission’s (FCC) deregulations. I then identify the changing meaning of news in the age of new media. I find that news in the new media era is best described as a paradox that allows for far more and yet remarkably less: innovations in new media opens new frontiers for journalism, but the incredibly fast pace of change amplifies existing problems in media. News was able to develop more types of stories, but less stories focused on news. News expanded audiences internationally, but the nonstop newscycle disrupted viewer trust in media. News diversified content options, while saturated competition siloed viewers. My story of CNN from 1980 to the late 20th Century presents a narrative that contextualizes the changing meaning of news in the age of new media. Clarity on what “media” means will provide a foundation for contemporary scholarship that focuses on the causes and solutions to the problems in the state of media today.
NGOs, the state, and legitimacy in contemporary China
Keywords: Political Science.

What explains the explosive growth of the NGO sector in China in recent decades? The extant literature on civil society and the state focuses on the organizations themselves, which falls short in explaining the phenomenon. By parting away from the agency and focusing on the state incentives, this dissertation explores why the state has facilitated the growth of the sector in recent decades. An important assumption that is clarified in this dissertation is that the NGO sector in China not only comprises civilian-established civil society organizations but also government-established groups and former public agencies that have been transitioned to NGOs. When examining state incentives, two incentives emerge - one is economic, which relates to the idea of using the legal term of "NGOs" to downsize parts of the bureaucracy, and second is political, which centers on using NGOs to outsource services with the ultimate goal of appeasing the masses. The former strategy emerged as early as the early 90s and was implemented in several provinces in the early 2000s as a response to fiscal shocks stemming from the tax-for-fee reforms. The comparison of China's case with NGO policy development in other authoritarian states -- Kazakhstan, Russia, and Belarus suggests that China is unique in that its incentive for NGO sector expansion was not only economic but political. The empirical evidence is drawn from county-level statistics, rural governance data (CHIP), fieldwork, web-scraped data on NGOs, a unique survey conducted in the field, and case studies
Nonadiabatic dynamics of gas phase molecules in collaboration with experiment
Keywords: Chemistry.

Photochemistry is the chemical response of molecules to light and drives many natural processes such as photosynthesis, vision, and bioluminescence. Nonradiative decay via intersystem crossing or internal conversion are mechanisms of particular interest due to the direct conversion of energy from light into mechanical motion. This presents unique difficulties to experiment due to the rapid time-scale on which these dynamics often occur. The involvement of multiple electronic states is a commensurate challenge to theoretical methods. Nonetheless, theoretical quantum chemistry approaches have had much success towards this objective and have been used in conjunction with experiment to produce powerful results. In particular, advancements such as GPU acceleration of electronic structure energy and gradient calculations have enabled on-the-fly simulation techniques such as ab initio multiple spawning (AIMS) to simulate these processes. In this dissertation, we use AIMS to produce one-to-one comparisons with experiment through direct modelling of experimental observables. We specifically highlight dynamics involved in photoisomerization of cis-stilbene and photodissociation of ortho-nitrophenol in comparison to time-resolved photoelectron spectra and ultrafast electron diffraction respectively. Additionally, we discuss enhancements of AIMS algorithms to address existing challenges in simulating excitations to higher lying electronic states