VictorJuiz/thesis huggingface dataset:
The Politics of Immediacy: Citizenship, Infrastructure and Sustainable Mobility in Mexico City

The dissertation examines the development of sustainable transportation policy in Mexico City. It argues that while sustainable transportation interventions have been defined as examples of a commitment to democratic planning and redistribution of infrastructure investment, in practice these projects have been implemented in a top-down fashion, legitimized by a handful of experts and have targeted only a handful of central districts. The implementation of these reforms are enabling the re-valorization of central neighborhoods and generating new forms of privatization and spatial inequality. The inequality produced is not only spatial. Sustainable transportation initiatives also produce differentiated publics, reducing participation to a handful of non-state actors, namely, experts and international NGOs./nI develop these claims through the analysis of Metrobus, the city’s BRT system, the bikeshare system Ecobici, and a street parking management program called Ecoparq. I draw on ethnographic evidence collected in Mexico City over 16 months in 2012 and 2013 consisting of extensive in- depth interviews with over 60 city officials, transportation experts, NGO staff members, social movements activists and citizens. I use this data to analyze política de movilidad as a policy space in which multiple actors within and outside the state have come together to redefine the goals, mechanisms and technologies used to plan and implement transportation infrastructure./nI draw on the metaphor of immediacy to analyze the practices that make possible these sustainable transportation projects and bring attention to three important policymaking practices and their effects. First, I argue that the need for an immediate response to environmental crises is generative of new policies that must be implemented quickly by bypassing existing bureaucratic and political structures. Second, I show how first-hand, immediate, experience is as an important temporal- spatial dimension of policymaking. By building pilot projects that appear successful and can make sense to any resident, city officials minimize conflict and bring legitimacy to controversial interventions. And third, I propose that the metaphor of immediacy complicates understandings of the role that infrastructures play in shaping public debates around green futures. Movilidad projects postpone inclusive planning processes in which planners could mediate debates in which citizens, experts and officials co-decide how to make the city more sustainable and democratic.

Advisor: Caldeira, Teresa
Strength, Resilience, and Resistance Among LGBT Service Members and Veterans: A Clinically-Oriented Content Analysis of the Film The Camouflage Closet

Due to prohibitions against U.S. military service among lesbian, gay, bisexual, and transgender (LGBT) people (e.g., Don’t Ask, Don’t Tell and the ban on transgender military service), little is known about LGBT service members and veterans. A growing body of research has identified disproportionate medical and mental health problems among LGBT veterans, which are associated with LGBT military minority stressors. The existing literature’s problem focus and lack of intervention research, combined with a paucity of culturally competent clinical training, leave social workers ill equipped to provide strength-based care as mandated by the Council on Social Work Education and National Association of Social Workers. This qualitative study uses Grounded Theory to analyze the verbal and nonverbal communication of 9 LGBT veterans featured in The Camouflage Closet, a documentary film about trauma and recovery. Considered within the contexts of current political and social climate, and historical representations of veterans, LGBT people, and LGBT veterans in film and news media, this study’s findings identify several new insights into LGBT military minority stressors and strengths. Findings include LGBT military-specific moral injury, post-traumatic growth, love, and the unique ability to communicate experiences of PTSD and LGBT military minority stress and resilience through visual representation. This study concludes with suggestions for strength-based research and practice with LGBT veterans./nKey Words: LGBT Military Minority Stress, Resilience, Strength-based Practice, LGBT Veteran Care

Advisor: Organista, Kurt
Hijacking Reason: The Moral Ecology of Implicit Bias

Implicit biases operating under the radar of conscious awareness and outside the bounds of what most people would endorse seem to undermine our ordinary understanding of human agency. I argue for a particular take on why these biases’ influence is so sinister—they “hijack” control of not only our actions but our very processes of practical reasoning and deliberation away from our selves and what we care about and value. I also argue that some implicit attitudes themselves count as values and forms of caring, such that our selves are partly implicit, or unconscious. This take on implicit attitudes is informed by how they work within particular social and geographic environments—that is, by their “moral ecology.” For example, implicit attitudes are central components in the mechanisms that sustain cycles of endemic poverty in U.S. inner cities. Somewhat counterintuitively, I conclude that the best way to combat the hijacking of reason is often precisely more hijacking, guided by research on the nature of implicit bias and the moral ecology of the environments in which it operates.

Advisor: Wallace, R. Jay
Campbell, John
Molecular Gas and Star Formation in Nearby Galaxies

In the local Universe, stars form within molecular clouds. Therefore, the properties of molecular clouds may determine the star formation rate. Conversely, star formation also gives feedback to the clouds where the stars reside. In this dissertation, I present the interplay between the molecular gas and star formation, through three parts below./nFirst, I identify and characterize the properties of molecular clouds in NGC4526, resulting in the first catalog of molecular clouds in an early-type galaxy. As a population, the molecular clouds in NGC4526 are gravitationally bound and have a steeper mass distribution than that in the Milky Way. These molecular clouds are also more luminous, denser, and have a higher velocity dispersion than their counterparts in the Milky Way. These different properties may be due to a more intense interstellar radiation field than in the Galactic disk and a weaker external pressure than in the Galactic center./nSecond, I combine the mm-wave interferometric data from CARMA and the optical Integral Field Unit data from CALIFA to study the molecular depletion time on kilo-parsec scales of nearby galaxies. In particular, the molecular depletion time between the galactic centers and disks is compared. I find that some galactic centers have shorter depletion time than that in the disks, which means that those centers form stars more efficiently per unit molecular gas mass. This places the galactic centers as an intermediate regime between galactic disks and starburst galaxies. The central drop of depletion time is also correlated with a central increase in the stellar mass surface density, suggesting that a shorter depletion time is associated with the molecular gas compression by the stellar gravitational potential./nThird, the feedback from star formation to maintain turbulence in the interstellar matter of M33 is investigated. I show that supernovae have enough energy to maintain atomic gas turbulence inside 4 kpc radius and within molecular clouds, assuming a constant value of turbulent dissipation time of 9.8 Myrs. In the outer parts, the energy from the differential rotation of galaxy is large enough to maintain atomic gas turbulence through the magneto-rotational instability (MRI). I conclude that the sum of supernovae and MRI energy maintains turbulence at all radii where atomic hydrogen is detected in M33.

Advisor: Blitz, Leo
Ono Tupuna, the richness of the ancestors. Multiples Landscapes Relationalities in Contemporary Indigenous Rapa Nui

Contemporary Rapa Nui is formed by a multiple and complex set of interactions, encounters, and circumstances that comprise the core of their indigenous identity, like many other indigenous people's realities. In this dissertation, I argue that there is not a simple or straightforward way of thinking about indigenous identities without falling into the trap of essentialism and stereotyping. Indigenous people are not what remained of ancestral civilizations, nor are they either invented nor folklorized commodities produced by “neo-shamanism” discourses. Recent theoretical contributions to the understanding of the relationship of native peoples with their territories have been fundamental to rethinking the meanings of indigeneity, but I argue that they continue to essentialize indigenous people relations with their past and the ways in which they are understood in the present. That is why in this dissertation I propose thinking about indigeneity through a notion of "multiple relationalities" as crucial for constructions of indigenous identity./nIn this dissertation, based on an extended fieldwork in Rapa Nui (which was formerly known as Easter Island), I contribute to the ways of thinking about indigeneity and ancestrality, especially concerning the manner in which is the relation of the indigenous peoples with their territories is understood. Indigenous territory is framed in multiple ways, constituting notions of landscapes that overlap, creating the unique and unrepeatable space of indigenous people's lands. This dissertation focuses on understanding how these landscapes are configured in Rapa Nui, and how they relate to configurations of indigenous identities Rapa Nui. Consequently, I argue that looking closely at the diverse and complex maps that have been constructed of Rapa Nui landscapes will allow us to analyze the nature of the Rapanui territoriality. I refer to these landscapes as the landscape of the ancestors and the Rapanui nation (chapter 3), the landscape of Chile and the State (chapter 4), and the landscape of tourism and collapse (chapter 4). Understanding how these landscapes are created, overlapped and contradicted, allows us to bring closer Rapanui identities and realities, and at the same time, to complicate broader indigeneity discourses that circulate globally

Advisor: Briggs, Charles L
Scheper-Hughes, Nancy
Large-Scale Brain Network Mechanics

The brain of any species can be modeled as a network of regions and connections between those regions. Here, I analyze the brain’s large-scale network mechanics. I show that the brain can be divided into subnetworks, each with a discrete function. I provide evidence that the each subnetwork’s processing is mostly modular; however, certain regions exist that perform integrative functions. I characterize this integrative set of regions in depth and discover that this set of regions exists across various species’ brains and even in man-made networks. I also identify an optimal network structure for cognitive processing. Finally, I demonstrate one mechanism for why the brain’s network structure was selected by evolution.

Advisor: D'Esposito, Mark
A Library of Fragments: Digital Quotations, New Literacies, and Attention on Social Media

From tweets to GIFs to memes, social media is awash in bite-sized texts that are perfect for quick, instantaneous consumption and viral sharing. Mixed up in the raucous frenzy of social media, however, are excerpts that originate from print media: quotations from novelists, poets, philosophers, and other authors. The book, far from extinct, has nevertheless become "fragmented," circulating in new ways on digital networks./nThis study examines the phenomenon of quotations—especially those from books—on the social network Tumblr. Its fundamental question is whether the fragmentation of the book represents a threat to traditional forms of attentive, immersive engagement with long-form texts./nThe study reports on three research phases, each with distinct methods and data. The first phase, relying on qualitative and quantitative discourse analysis, examined the role of books and traditionally print-based discourses within the context of Tumblr. The second employed ethnographic data techniques, questionnaires and interviews, to uncover Tumblr users' purposes for sharing quotes from books as well as the ways that quoting connects to these users' broader experiences of literacy. The third phase used computational linguistics to distinguish between different types of quotations and to illuminate the features that contribute to "quotability."/nThis study finds that quotation can be—though is not always—intertwined with traditional forms of reading and literate attention. Chapter 3 demonstrates that the quoting of books in particular is a fundamental part of the larger practice of quoting on Tumblr; it further illustrates some of the wide variety of quotations that circulate on this network, from misquotations attributed to famous authors to those quotes that are carefully annotated with bibliographic information, scholarly vocabulary, and other signs of deep familiarity with source texts. Chapter 4 reveals that, for those who quote from books on Tumblr, quoting is often not a form of distraction; rather it can deepen their experience of reading and lead them to discover new books. Yet quoting also serves more fundamental purposes of self-expression and self-care, functions that may be related to the fact that quoting is a starkly gendered (largely female) practice. Chapter 5 suggests that, while many quotations are indeed designed to be easily-decontextualized adages, others are specifically tailored to fulfill quoters' desires to express their intimate thoughts and feelings. Some quotes seem to be tailored to be appreciated by those with deep familiarity with the source text, though such quotations are less popular than easily-decontextualized ones./nThe fragmentation of the book does not fundamentally threaten traditional forms of reading, though the very purposes of reading are increasingly bound up with self-expression and self-care made possible through social media. The conclusion chapter considers the ramifications of these findings for media studies, the history of the book, and educational practice.

Advisor: Freedman, Sarah W
Digital Writing in the Academy:  Gains, Losses, and Rigorous Playfulness

The ethnographic study presented here documents emergent behaviors that arose when two multimodal composing and production tools - Collabosphere and Tumblr - were used in three different college courses (Introductory Psychology, Education 1B, and College Writing 101). The work addresses how conceptions of writing in the college classroom and across disciplines shift, converge, and vary across courses and between disciplines. I use Engeström’s (1999) model of activity theory to show how the introduction of new tools pushed both students and teachers to think more broadly and creatively about how they compose and comport themselves in academic settings. Specifically, this work reveals instances of expansive transformation as two activity systems – academic writing and digital writing – converged in these classrooms. By documenting new approaches that students and teachers developed when using new tools in an academic setting, I hope to visualize new opportunities for university writing to expand and include new literacy practices./nThis study documents how digital tools in the Academy were perceived, repurposed and used in a variety of different ways. I used a combination of interviews with faculty and students, observations, and analysis of semiotic materials to gain a holistic understanding of the dynamic activity systems at play in each setting, and across the university. Specifically, I endeavored to document the types of expectations placed on undergraduate students and faculty to use digital tools in innovative and compelling ways, and how those expectations informed how both approached composing in their courses. Here I strove to understand the new demands on college writers within different disciplinary departments, new kinds of audiences, and new kinds of texts as students collaboratively composed. This study also conceives to help educators and teaching faculty think about what kinds of methods, rubrics and assessment frameworks would help support students using new tools for writing in college classrooms./nOne of the central findings of this study is that in order to make room for expansive learning and new systems of writing to emerge, teachers must make explicit the course goals and assessment models for grading and evaluating digital and multimodal pieces. Without this framework, students often default to those writing models that were successful for them in the past, which were text-heavy and often discipline-specific. Further, teachers also need to help extend student’s notions of communication to include the visual and aural in a way that is both meaningful and critical. This study showed that it was not enough for students to simply present and prioritize multimodal composing, but that students needed a conceptual frame to understand how and why composing in different modes supported their analytic reasoning, and feel confident in their ability to synthesize them into their composing work.

Advisor: Hull, Glynda A.
Phonon Effects on Ultrafast Dynamics in Photosynthesis and Optoelectronic Materials: Forays with Two-Dimensional Electronic Spectroscopy

This dissertation describes the use of two-dimensional electronic spectroscopy to explore the impact of phonons and vibrations on the ultrafast electronic processes in photosynthetic light harvesting, hot carrier persistence in perovskite photovoltaics, and efficient photoluminescence in a 2D semiconductor. Each example represents a case where a unified picture of nuclear and electronic response is needed to understand the mechanism. In the introduction, we summarize the electron-phonon interactions that affect optoelectronic processes, and we introduce ultrafast two-dimensional spectroscopy (2D-ES) and the physical information accessed through this experiment. Coherences and wavepackets are introduced, and a time-dependent picture of quantum mechanics is emphasized throughout. The concept of an open system and the impact of environmental fluctuations on dynamics and measurements is equally important. In Chapter 2 these are explored using numerically exact open-system simulations to show the effect of vibrations in the chlorophyll molecule on coherent energy transfer in a photosynthetic complex and on our ability to measure it using two-dimensional spectroscopy. We show that even weak coupling to vibrations generates vibrational wavepacket signatures, and that resonances between vibrations and electronic energy gaps produce vibronic energy transfer effects that are sensitive to environmental fluctuations./nThe experimental portion follows with a discussion of strategies for applying two-dimensional spectroscopy techniques to samples with weak signals and/or strong scatter. These include signal processing methods and a new scheme we have devised for rapid scatter subtraction using a cheap, easily programmed microprocessor. We also discuss extensive modifications that allow fluorescence-detected 2D-ES. In Chapter 4, 2D-ES is used to study methylammonium lead iodide perovskite, a hybrid organic-inorganic photovoltaic. We find a vibrational wavepacket that is a good candidate mode for a phonon bottleneck effect thought to slow hot carrier cooling in this material. Chapter 5 presents preliminary results from a 2D-ES study of another semiconductor, single-layer MoS2. We identify from the temperature-dependent 2D lineshape an optical phonon mode principally responsible for early-time charge carrier scattering. We also observe a coupling between two opposite-spin excitons, in agreement with calculations that predict significant exchange interactions.

Advisor: Fleming, Graham R
System Design for Large Scale Machine Learning

The last decade has seen two main trends in the large scale computing: on the one hand we have seen the growth of cloud computing where a number of big data applications are deployed on shared cluster of machines. On the other hand there is a deluge of machine learning algorithms used for applications ranging from image classification, machine translation to graph processing, and scientific analysis on large datasets. In light of these trends, a number of challenges arise in terms of how we program, deploy and achieve high performance for large scale machine learning applications./nIn this dissertation we study the execution properties of machine learning applications and based on these properties we present the design and implementation of systems that can address the above challenges. We first identify how choosing the appropriate hardware can affect the performance of applications and describe Ernest, an efficient performance prediction scheme that uses experiment design to minimize the cost and time taken for building performance models. We then design scheduling mechanisms that can improve performance using two approaches: first by improving data access time by accounting for locality using data-aware scheduling and then by using scalable scheduling techniques that can reduce coordination overheads.

Advisor: Franklin, Michael J
Stoica, Ion
Large-Scale Analysis of Modern Code Review Practices and Software Security in Open Source Software

Modern code review is a lightweight and informal process for integrating changes into a software project, popularized by GitHub and pull requests. However, having a rich empirical understanding of modern code review and its effects on software quality and security can help development teams make intelligent, informed decisions, analyzing the costs and the benefits of implementing code review for their projects, and provide insight on how to support and improve its use./nThis dissertation presents the results of our analyses on the relationships between modern code review practice and software quality and security, across a large population of open source software projects. First, we describe our neural network-based quantification model which allows us to efficiently estimate the number of security bugs reported to a software project. Our model builds on prior quantification-optimized models with a novel regularization technique we call random proportion batching. We use our quantification model to perform association analysis of very large samples of code review data, confirming and generalizing prior work on the relationship between code review and software security and quality. We then leverage timeseries changepoint detection techniques to mine for repositories that have implemented code review in the middle of their development. We use this dataset to explore the causal treatment effect of implementing code review on software quality and security. We find that implementing code review may significantly reduce security issues for projects that are already prone to them, but may significantly increase overall issues filed against projects. Finally, we expand our changepoint detection to find and analyze the effect of using automated code review services, finding that their use may significantly decrease issues reported to a project. These findings give evidence for modern code review being an effective tool for improving software quality and security. They also suggest that the development of better tools supporting code review, particularly for software security, could magnify this benefit while decreasing the cost of integrating code review into a team's development process.

Advisor: Wagner, David