VictorJuiz/thesis huggingface dataset:
Netroots organizing, from viral marketing to Barack Obama [electronic resource] : how Berger and Luckmann's theory of institutionalization resolves the paradox of embedded agency

The present dissertation is a historical ethnographic case study of the emergence of the institution of netroots organizing in Democratic Party politics. It offers five contributions to the sociological study of institutions: First, the dissertation elucidates how Berger and Luckmann's (1967) theory of institutionalization and its constituent moments of internalization, externalization, and objectivation resolve the paradox of embedded agency that occurs when instititutional researchers focus on either the constraining or the empowering sides of institutions. Second, the dissertation shows how the theory explains institutional work—the reproduction, disruption, and change of existing institutions and the emergence of new ones—by means of problematization during the transition from internalization to externalization. Third, the dissertation illustrates that actions and meanings are involved in a continuous dialectical interplay such that researchers' understanding of institutional dynamics is incomplete without a prior understanding of habitual developments. Fourth, the dissertation reveals that institutional entrepreneurs are sometimes social constructions resulting from institutionalization, not the source of institutionalization. Rather, anarchic organizing—the application of existing habits and institutions to emerging probems—can serve as the impetus for novel institutionalization. Agents only construct interests once new habits and institutions prove valuable, and they then develop rationalized myths that ascribe the status of entrepreneurs to those perceived to have constructed these habits and institutions. Fifth, the dissertation demonstrates that Berger and Luckmann's (1967) theory shows the dynamics of delegitimation when the powerful and less powerful encounter each other and illustrates some of the options available to the less powerful when confronted with conflict.

Keywords: Management Science and Engineering.
Advisor: Barley Stephen R. primary advisor. Thesis advisor
Hinds Pamela primary advisor. Thesis advisor
Granovetter Mark S. advisor. Thesis advisor
March James G. advisor. Thesis advisor
McAdam Doug advisor. Thesis advisor
Neural machine translation [electronic resource]

Being able to communicate seamlessly across the entire repertoire of human languages is, to me, an ultimately rewarding goal for an intelligent system. Despite great progress in the field of Statistical Machine Translation (SMT) over the past two decades, the translation quality has not yet been satisfactory; at the same time, SMT systems become increasing complex with many different components built separately, rendering it extremely difficult to make further advancement. Recently, Neural Machine Translation (NMT) emerges as a promising solution to the problem of machine translation. At its core, NMT consists of a single deep neural network with millions of neurons that learn to directly map source sentences to target sentences. NMT is powerful because it is an end-to-end deep-learning framework that is significantly better than SMT in capturing long-range dependencies in sentences and generalizing well to unseen texts. This dissertation presents all of the essence of Neural Machine Translation (NMT), through which I discuss how I have pushed the limits of NMT, making it applicable to a wide variety of languages with state-of-the-art performance. My contributions include addressing the rare word problem with copy mechanisms, improving the attention mechanism to better select local contexts in the source sentence, and translating at the character level with a hybrid architecture. Towards the future of NMT, I discuss how to utilize data from a wide variety of tasks such as parsing, image caption generation, and unsupervised learning to improve translation; as well as how to compress NMT models for mobile devices. I conclude with how my work influences subsequent research as well as provide an in-depth coverage on the existing research landscape, highlight potential research directions, and speculate on future elements needed to further advance NMT.

Advisor: Manning Christopher D. primary advisor. Thesis advisor
Jurafsky Dan
Le Quoc V. advisor. Thesis advisor
Ng Andrew Y.
Neural mechanisms of learning and memory in the human medial temporal lobe [electronic resource]

The medial temporal lobe is critical for enabling memory for the events of one's personal past. However, whether medial temporal lobe subregions perform shared or qualitatively distinct computations to support these memories is a topic of debate. One prominent theoretical perspective proposes that complementary behavioral expressions of memory for past events are enabled via the creation of separated versus overlapping neural representations for events that share similar elements, and that these representations are formed by the hippocampus and medial temporal lobe cortex, respectively. A wealth of empirical data has examined this proposal by asking whether these complementary behavioral expressions of memory are differentially linked to integrity and / or functional activation of the hippocampus and medial temporal lobe cortex. Here, we examined complementary medial temporal lobe computations through a different lens, and asked whether the degree of neural overlap in the hippocampus and medial temporal lobe cortex elicited by stimuli during encoding is differentially linked to the ability to recognize those stimuli in the future. We addressed this question with two experiments using converging methodologies. In Experiment 1 we used high-resolution functional magnetic resonance imaging and pattern similarity analyses to quantify neural overlap across the spatial topography in medial temporal lobe subregions during encoding. We found that the relationship between pattern similarity during encoding and subsequent memory dissociated across the hippocampus and medial temporal lobe cortex: later memory was linked to greater across-item pattern distinctiveness in the hippocampus, but to greater across-item pattern similarity in medial temporal lobe cortex. Additionally, by comparing neural patterns elicited by individual stimuli regardless of later memory for these stimuli, we found that perirhinal cortex and parahippocampal cortex exhibited differential content sensitivity for multiple stimulus categories, whereas the hippocampus failed to demonstrate such content sensitivity. In Experiment 2 we used intracranial electroencephalography to quantify neural overlap across the temporal evolution of population-level neural activity in medial temporal lobe subregions during encoding. We found that later memory was linked to greater across-item pattern distinctiveness in the hippocampus but not in medial temporal lobe cortex, and that the strength of these relationships was modulated by the demands on behavioral expressions of memory during retrieval. These data provide novel evidence for complementary learning mechanisms across the hippocampus and medial temporal lobe cortex, and suggest that these mechanisms operate across both spatial and temporal dimensions of neural codes.

Keywords: Psychology.
Advisor: Wagner Anthony David primary advisor. Thesis advisor
Grill-Spector Kalanit advisor. Thesis advisor
McClelland James L. advisor. Thesis advisor
Neuronal Activity-Mediated OPC Proliferation Following White Matter Injury

Multiple Sclerosis is a neurological disorder characterized by demyelinated lesions in the central nervous system (CNS), inflammation mediated largely by autoimmune T cells, and eventual motor and sensory loss. Remyelination in the disease is often slow or incomplete, and mechanisms of remyelination are still largely undescribed. Normal myelination occurs through the differentiation of oligodendrocyte precursor cells (OPCs) into functionally mature oligodendrocytes capable of wrapping myelin onto axons. Electrical activation in a premotor neural circuit via optogenetic stimulation induces proliferation of OPCs, oligodendrogenesis, and increased myelination of that circuit. This mechanism could potentially be used as a tool to enhance remyelination after injury. In this work, we determine whether optogenetic stimulation can enhance remyelination in the motor cortex. We show that optogenetic stimulation increases proliferation of OPCs in the corpus callosum following lysolecithin-induced demyelination of that region. Since OPCs are the precursors to mature oligodendrocyts and myelin formation, optogenetic stimulation may provide the first trigger to remyelination.

Keywords:  Department of Biology
Biology
Neurobiology
Remyelination
Optogenetics
Lysolecithin
Multiple Sclerosis
Thesis
Advisor: Monje-Diesseroth Michelle
McConnel Susan
New Affordable Housing and School Quality Measures in Florida

This paper examines the impact of introducing new affordable housing on the school quality, as defined by standardized test scores, of nearby schools. The results serve to allay the concerns of opponents of affordable housing who may fear the quality of their schools would deteriorate, as well as inform policy makers considering where to place new affordable housing. I utilize data on affordable housing and schools from the state of Florida. I use an event-study model to compare the standardized test scores of schools before and after the introduction of affordable housing nearby. Nearby “untreated” neighbors who do not receive new affordable housing serve as the matched control. I find no statistically significant general impact from the introduction of affordable housing, with a slightly negative general impact on test scores as the size of the new affordable housing increases. However, I find that the effect is dependent on socioeconomic status as measured by Free and Reduced Lunch Program eligibility. I show that standardized test scores increase in middle schools with low rates of Free and Reduced Price Lunch eligibility after the introduction of new affordable housing. While further study is needed, policymakers should take note that introducing new affordable housing near schools of a higher socioeconomic status causes the average achievement of the entire school to increase.

Keywords:  Department of Economics
Stanford Department of Economics
affordable housing
school quality
Florida
event-study model
standardized test scores
Free and Reduced Lunch Program
Thesis
Advisor: Hanushek Eric
New constructions and computations in rigid and flexible symplectic geometry and applications to several complex variables [electronic resource]

This thesis is divided into three parts. In the first part, we give a complete characterization of those disk bundles over surfaces which embed as rationally convex strictly pseudoconvex domains in $\C^2$. We recall some classical obstructions and prove some deeper ones related to symplectic and contact topology. We explain the close connection to Lagrangian surfaces with isolated singularities and develop techniques for constructing such surfaces. Our proof also gives a complete characterization of Lagrangian surfaces with open Whitney umbrellas, answering a question first posed by Givental in 1986. In the second part, we introduce a class of Weinstein manifolds which are sublevel sets of flexible Weinstein manifolds but are not themselves flexible. These manifolds, called subflexible, exhibit rather subtle behavior with respect to both pseudoholomorphic curve invariants and symplectic flexibility. We construct a large class of examples and prove that every flexible Weinstein manifold can be Weinstein homotoped to have a nonflexible sublevel set. This resolves some recent open questions in symplectic flexibility. In the third part, we establish an infinitesimal version of fragility for squared Dehn twists around even dimensional Lagrangian spheres. The precise formulation involves twisting the Fukaya category by a closed two-form or bulk deforming it by a half-dimensional cycle. As our main application, we compute the twisted and bulk deformed symplectic cohomology of the subflexible Weinstein manifolds constructed in the second part.

Keywords: Mathematics.
Advisor: Eliashberg Y.
Ionel Eleny advisor. Thesis advisor
Pardon John advisor. Thesis advisor
New experimental tests for gravity and dark matter [electronic resource]

The behavior of gravity is well understood and highly constrained on length scales from millimeters to the size of the Solar System. New physics, such as extra dimensions or new forces, may modify the behavior of gravity below a millimeter. On the other end of the spectrum, observations of galaxies, galaxy clusters, supernovae, and the Cosmic Microwave Background all point to the gravitational dominance of dark matter and dark energy over the ordinary matter content of the Universe. It is therefore worth investigating, with high precision, the behavior of gravity at the longest distance scales as well. In this dissertation, I describe a recent proposal for a space-based experiment, optimized to test the inverse square law with great accuracy at scales of up to 100 AU. This is the largest length scale that can be reached with a direct probe using current technology. I also describe a new experimental strategy for testing putative signals of dark matter decay or annihilation. Merging galaxy clusters such as the Bullet Cluster provide a powerful testing ground for indirect detection of dark matter. The spatial distribution of the dark matter is both directly measurable through gravitational lensing and substantially different from the distribution of potential astrophysical backgrounds. I propose to use this spatial information to identify the origin of indirect detection signals, and show that even statistical excesses of a few sigma can be robustly tested for consistency--or inconsistency--with a dark matter source.

Keywords: Physics.
Advisor: Graham Peter (Peter Wickelgren) primary advisor. Thesis advisor
Dimopoulos Savas
Gratta Giorgio advisor. Thesis advisor
New insights into galaxy cluster astrophysics using the Suzaku X-ray satellite [electronic resource]

Galaxy clusters enable a broad range of astrophysical studies, from the microphysics of hot tenuous plasmas, to the physics of galaxy evolution, to constraining cosmological models. In particular, much can, and has, been learned from detailed studies of the nearest brightest systems, in which the relevant astrophysics can be viewed "in closeup". The focus of this thesis is the analysis of , and extraction of novel results from, observations of nearby galaxy clusters made with the Suzaku X-ray satellite. In particular, the first part of the thesis is focused on the analysis of data from Suzaku Key Project observations of the Perseus Cluster, the X-ray brightest cluster in the sky, which offered the most complete view to date of any galaxy cluster from its core to the outer edge. The results are presented across several chapters. In Chapter 2, we examine the behaviour of various physical properties of the intracluster medium (ICM), some of which, most prominently including the entropy, indicate a presence of density inhomogeneities at large radii (r> r500). In Chapter 3, we report evidence for large megaparsec-scale sloshing motions of the ICM in Perseus, a phenomenon which had not been observed before at these scales. In Chapter 4, we present the first spatially resolved study of the chemical composition of the ICM throughout the full volume of a cluster. Notably, we find a homogeneous distribution of heavy elements at large radii which indicates that these elements, produced by supernovae, were likely injected into and mixed with the intergalactic gas before galaxy clusters formed. In the second part of this thesis, I present a detailed spectral examination of Suzaku observations of the four X-ray brightest clusters, in order to search for the presence of a ~3.5 keV X-ray emission line. The presence of such a line has been claimed in some previous X-ray studies of the Perseus Cluster, and some other galaxies and clusters. It has been proposed that such a feature could be a decay signature from sterile neutrino dark matter. My results present a severe challenge to this interpretation. Alternative scenarios for the origin of the ~3.5 keV feature are discussed.

Keywords: Physics.
Advisor: Allen Steven
Madejski Grzegorz
Wechsler Risa H. (Risa Heyrman) advisor. Thesis advisor
The new institutionalism of occupations [electronic resource]

During the past few decades, licensure, a state-enforced mechanism for regulating occupational entry, quickly became the most prevalent form of occupational closure. Broad consensus among researchers is that licensure creates wage premiums by establishing economic monopolies. However, licensing has a much broader impact on occupational structure. Using a new occupational dataset, covering thirty years, I argue that, by redrawing boundary lines, licensing recreates occupational institutions and can have an effect on the wages, composition, and culture of an occupation. The first paper reveals that licensing, instead of increasing wages, creates a set of institutional mechanisms that enhance entry into the occupation, particularly for historically-disadvantaged groups, while simultaneously stagnating quality. The second paper shows that licensing eases access into occupations for immigrants, a majority of whom are in the high-skilled primary labor market, while leaving behind the most vulnerable immigrant labor groups. Finally, the third paper demonstrates that, though women enter licensed occupations at a higher rate than unlicensed occupations, they are also disproportionately clustered at the bottom of the wage distribution, resulting in increased within-gender inequality. At its core, closure is the erection of boundaries between groups that struggle for the exclusion of others, in order to monopolize resources. In focusing on the second part of this equation, resource monopolization, past theorists neglected to look closely at the boundaries, even though these boundaries can restructure a group in socially meaningful ways. Taking these effects together, my simple conclusion is that closure is much more than a monopoly mechanism -- it is reformative.

Keywords: Sociology.
Advisor: Grusky David B. primary advisor. Thesis advisor
Snipp C. Matthew advisor. Thesis advisor
Sorensen Jesper
New materials for biomedical imaging in the second near-infrared window [electronic resource]

Traditional medical fluorescence imaging uses wavelengths spanning the visible (400-700 nm) and infrared (700-900 nm) regions of the electromagnetic spectrum. These wavelengths display poor optical penetration depths as well as high levels of photon scattering and background autofluorescence. As a result, traditional medical fluorescence imaging cannot effectively resolve features below the surface of the skin (~0.4 mm penetration depths). We have demonstrated that fluorescence imaging past 1000 nm in an optical window termed the second near-infrared window (NIR-II; 1000-1700 nm) reduces the adverse interactions between light and tissue described above, leading to 5-fold higher tumor-to-background ratios with 10-fold deeper tissue penetration depths. Fluorescence imaging in the second near-infrared widow (NIR-II; 1000-1700 nm) is a powerful technique that gives doctors and researchers a view into the human body or turbid biological tissues. However, the development of this imaging modality relies on new materials with advanced optical properties. This work aims to develop highly purified single-walled carbon nanotubes (SWCNTs) of a single diameter with unique optical signatures that lower requisite doses for NIR-II tumor detection and treatment. Although SWCNTs provide a promising approach for future clinical applications, the development of organic NIR-II dyes similar in structure and pharmacokinetics to FDA-approved medical fluorophores is a faster route to the clinic. This work additionally presents the first NIR-II organic dyes with high levels of excretion as well as a high quantum yield.

Keywords: Materials Science and Engineering.
Advisor: Dai Hongjie
Heilshorn Sarah primary advisor. Thesis advisor
Cheng Zhen
Nitrogenous disinfection byproducts [electronic resource] : identifying formation pathways and developing engineering controls in impaired and recycled water

Disinfection of potable water is one of the great public health victories of the twentieth century, responsible for the avoidance of millions of deaths due to waterborne illness. However, application of disinfectants, typically chemical oxidants, leads to formation of hundreds of trace contaminants, often carcinogens, and consumption of chlorinated water has been epidemiologically linked to bladder cancer and certain birth defects. Eleven of these compounds are federally regulated in drinking water, but certain non-regulated disinfection byproducts (DBPs) are orders of magnitude more toxic than currently regulated compounds. Two specific DBPs, chloropicrin and N-nitrosodimethylamine (NDMA), are especially genotoxic, and are associated with nitrogen input into drinking water supplies. Wastewater-impacted drinking water and recycled wastewater are enriched in the precursors of these compounds, and their formation during potable water treatment is likely to grow, as wastewater increasingly contributes to the water supply. This thesis focuses on applying the tools of environmental organic chemistry to identify the chemical precursors and formation mechanisms of these compounds, leading to strategies for their control during water treatment. In particular, ozonation of primary and secondary amine compounds, leading to formation of nitro compound intermediates, was found be responsible for chloropicrin formation during water treatment. Secondary N-methylamines and primary amines geminal to facile leaving groups were particularly potent precursors, forming chloropicrin at up to 50% yield when exposed to ozone followed by chlorine. Based on this predominant formation pathway, chloropicrin precursors may be oxidized upstream of ozone addition to prevent chloropicrin formation. Strategies for controlling NDMA formation, a major concern during wastewater recycling, were developed based on an understanding of the chemical composition of NDMA precursors, and chloramines, the primary disinfectant applied during wastewater reuse. Minor modifications to wastewater recycling operations, in particular switching from low-pressure to medium-pressure mercury lamps for ultraviolet light treatment, and minor adjustments in the application of chloramines, were shown to dramatically reduce NDMA concentrations in final effluent. Finally, the effluent from a new, all-anaerobic wastewater treatment system was demonstrated to more efficiently remove trace contaminants and DBP precursors than conventional aerobic treatment, suggesting that this energy-saving technology may also be more suitable for water reuse than conventional treatment. These findings facilitate reducing the chronic health risk associated with consumption of (intentionally or unintentionally) recycled wastewater.

Keywords: Civil and Environmental Engineering.
Advisor: Mitch William A. primary advisor. Thesis advisor
Luthy Richard G. advisor. Thesis advisor
McCarty Perry L. advisor. Thesis advisor