VictorJuiz/thesis huggingface dataset:
Prop 68 to decide funding for water, parks and climate change in California

Conservation projects across the state, as well as state and local parks, are in need of funding. In light of this need, Proposition 68 in Tuesday’s June primary elections in California is seeking to bolster projects that tackle water and natural resource conservation, improve park access and increase resilience to climate change. If passed, $4 billion in bonds will be allocated statewide for improvement of parks, projects on environmental protection and restoration, water infrastructure and flood protection. The discussion of whether to pass Prop 68 is however more of a question of whether to allocate the bonds now in anticipation of climate change or to use other sources of funding available now or in the future.

Keywords:  Department of Communication
Amy Cruz
Department of Communication and Journalism
MA Journalism Program
environment
climate change
water security
Proposition 68
June primary ballot
California
wetlands conservation
South Bay Salt Ponds
Thesis
Advisor: Zacharia Janine
Prosocial Decision-Making in Early Childhood

From a young age, children will spontaneously help others achieve goals. In many circumstances, however, it is unclear why exactly someone is failing to achieve a goal. In these situations, it is necessary to figure out the likely reason they are failing so that you can tailor your help accordingly. In the three experiments described in this thesis, 24- to 48-month-old children learned about three (Exp. 1) or two (Exp. 2 and 3) music toys. They then watched a confederate fail to activate a toy and request help. We varied the likely source of this confederate’s failure and, in all three experiments, children were able to use their prior knowledge about the toys to target the likely source of failure. When the likely source was the toy itself, children helped by changing the toy. When the likely source was the action taken on the toy, children helped by changing the action taken on the toy.

Keywords: Symbolic Systems
cognitive development
prosocial behavior
Thesis
Protective mechanisms of photosynthetic processes against oxidative damage in Chlamydomonas Reinhardt II

Sunlight is by far the most abundant source of energy that drives processes on the Earth. Oxygenic photosynthesis is a series of catalytic reactions that convert the solar energy into chemical bond energy. The process begins by harvesting light energy by pigment-protein complexes in photosynthetic membranes. The absorbed light energy drives a series of electron transfer reactions that generate reducing equivalents and high energy compounds. These chemicals are used to fuel the Calvin Benson Bassham (CBB) Cycle in which atmospheric carbon dioxide (CO2) is fixed in energy rich organic molecules. Molecular oxygen (O2) is another major product generated in photosynthesis. Although necessary for aerobic respiration, O¬2 can also form reactive oxygen species (ROS) that can cause severe cellular damage. Excess light energy absorbed by photosynthetic pigments may result in the transfer of electrons to O2 and the formation of ROS. Photosynthetic processes are particularly susceptible to oxidative damage since the photosynthetic complexes contain many O2 sensitive components. Furthermore, control of the photosynthetic activity and the production and quenching of ROS are critical since the rates of photosynthetic electron transport are constantly impacted by environmental conditions such as light intensity and the atmospheric gas compositions. This dissertation explores the regulatory functions of proteins associated with protection of the photosynthetic apparatus from oxidative damage that can impact both the assembly and activity of photosynthetic complexes. The green alga Chlamydomonas reinhardtii (Chlamydomonas throughout) was used for all experiments described in this study. The first chapter introduces the reader to photosynthesis. The second chapter focuses on the CGL71, a protein critical for protecting photosystem I (PSI) assembly from oxidative damage. In the third chapter, the first part explores a high-throughput mutant screen to get Chlamydomonas mutants in proteins associated with oxidative damage. The second part of the third chapter focuses on RMT2, which was selected from the screen. It is a methyltransferase, which allows us to investigate the biological roles of post-translational modification in regulation of photosynthesis. Overall, this work reveals novel components associated with mechanisms critical for protecting photosynthetic functions from oxidative damage.

Keywords: Biology.
Advisor: Grossman Arthur (Arthur R.) 
Mudgett Mary Beth
Long Sharon R. 
Moerner W. E. (William Esco)
Proximity effects between topological insulators and insulating ferromagnets

To investigate the effects due to proximity between a three-dimensional topological insulator (TI) and an insulating ferromagnet (IF), TI-IF thin film bilayers were fabricated with pulsed laser deposition. Either bismuth(III) selenide (Bi2Se3) or bismuth-antimony(III) telluride (BST) was used for the TI layer, whereas the IF layer was formed by the Heisenberg ferromagnet EuS. While a positive magnetoresistance was observed above the Curie temperature of EuS, as ubiquitously observed in high-quality TI thin films, an unusual negative magnetoresistance was observed below the Curie temperature in the variable-range hopping regime. The angular dependence of such negative magnetoresistance indicates an orbit origin. Specific to BST-EuS bilayers, when the bulk conduction is minimized, magnetic anomalies in AC susceptibility were observed concurrently with resistive anomalies at the same temperatures, suggesting an interface magnetic order. These phenomena together suggest two-stage proximity effects between the topological insulators and the insulating ferromagnet, and provide first steps to realize the half-integer quantum anomalous Hall effect.

Keywords: Physics.
Advisor: Kapitulnik Aharon 
Fisher Ian R. (Ian Randal) 
Qi Xiaoliang
Pushing Peace: The Relationship Between the Taliban’s Strength and Its Openness to Negotiations

Since 2009, the United States has worked to push the Taliban into negotiating a peaceful end to the conflict in Afghanistan. However, U.S. policymakers have consistently struggled to strike an appropriate balance between degrading the Taliban’s operational capabilities through the use of military force, and encouraging its diplomatic cooperation by exercising restraint. The question of whether an insurgent group is more open to negotiations when it is weak or when it is strong is central to literature on conflict resolution and counterinsurgency warfare. Similarly, U.S. strategy in Afghanistan begs the question—does the Taliban make a better partner for peace when it is weak or when it is strong? In order to answer this question, I chose to measure the Taliban’s strength over time, charting it against changes in its attitude toward negotiations. In order to do this, I analyzed three variables that are closely related to an insurgent group’s ability to operate effectively: extent of territorial control, continuity and cohesion of leadership, and access to public support. The results from my two case studies on the Taliban (Pre-2013 and Post-2013) suggest that the Taliban was more willing to negotiate when its territorial holds and perceived public support were weak, and when its central leadership was strong. These findings are significant, because they challenge the idea that weakening the Taliban on all fronts is most conducive to encouraging peace talks. Rather, they suggest that the United States will be most successful in bringing the Taliban to the negotiating table if it limits the Taliban’s territorial control and public support, while preserving the continuity and cohesion of its top leaders and diplomatic decision-makers.

Keywords: Center for International Security and Cooperation
Stanford University
Taliban
Afghanistan
negotiation
insurgency
counterinsurgency
territory
leadership
public support
Thesis
Advisor: Schultz Kenneth A.
Putting individuals in context : interdisciplinary and behavioral science approaches for understanding environmental and human health decisions

Attention for addressing human and environmental health issues is often directed towards scientific and technological solutions. However, ensuring the successful uptake and implementation of these solutions requires accounting for the critical interplay of context-specific and individual-level factors that influence human behavior and decision-making. This dissertation presents two cases that demonstrate the value of using interdisciplinary approaches to account for contextual and social factors in developing an understanding of individual-level attitudes and decisions. While these studies focus on different populations and contexts, both cases serve to illustrate how pro-social attitudes at the individual level are negotiated, internalized and acted upon in ways that reflect important contextual and social factors. Finally, these cases help illustrate the benefits of using mixed methods approaches to characterize differences in individual-level attitudes and behaviors that are population-specific and socially and contextually dependent, in order to better understand the diversity of human behavior.

Advisor: Ardoin Nicole M. (Nicole Michele) 
Miller Dale (Dale A.)
Armel Kathleen
Ortolano Leonard
Quality of what? Merit-based selection and the demands of justice

Many people believe that colleges should admit students on the basis of merit: highly-qualified students should get to go to resource-rich, selective schools. Yet enacting this "merit principle" is challenging because we live in a society marked by persistent group-based inequality along the lines of race, class, nationality, sexuality, ability status, and gender. As I demonstrate in chapters one through three of this dissertation, merit is a fraught foundation for distributing educational opportunity because merit itself is endogenous: it is often constructed and evaluated in ways that reflect the biases, beliefs, and backgrounds of this with preexisting power. Given this pattern, how should selective colleges structure their admissions procedures? In chapter four, I argue that universities should create independent Merit Committees, inclusive of representatives from previously-excluded groups, that work together to define merit and determine background-sensitive proxies for measuring merit in applicants from a broad range of backgrounds. I outline three further normative principles to address concerns about background inequality and merit endogeneity: the institution-dependent merit definition principle, the adequacy principle, and the teachability principle. Guided by these principles, the Merit Committee is tasked with establishing a university-specific adequacy threshold. In chapter five I argue that colleges should randomize admission amongst all applicants who cross this adequacy threshold.

Keywords: Political Science.
Advisor: Reich Rob 
Satz Debra 
McQueen Alison (Alison E. J.)
Quantifying ascaris : changing the game in the fight against parasitic worms

The intestinal worm Ascaris infects approximately 15% of the global population, impairing cognitive development and stunting growth in children and preventing beneficial use of biosolids as a soil amendment. Current assays have high variance and are time-consuming. More rapid, accurate methods will improve clinical diagnostics and ensure the effectiveness of technologies that inactivate Ascaris eggs in biosolids prior to their use in agriculture. A systematic literature review of quantification methods revealed significant heterogeneity between studies, all of which involve the following steps: (1) separation of eggs from a sample matrix (soil, feces, biosolids, water), (2) sedimentation or flotation to concentrate eggs, and (3) counting of eggs by microscopy, including egg viability assessments for inactivation studies. A meta-regression found that assay variables with greatest positive impact on recovery rates achieved in steps (1) and (2) are use of higher density flotation solutions and 7X surfactant. For Step (3), observer-based microscopy poses an obstacle to quantification in a timely and accurate manner. Assessment of inactivation is the most time-consuming step, typically requiring egg incubation for 15-35 days. The review also addresses the widespread adoption of a "Gold Standard" based upon a consensus of methods that vary from study-to-study. This lack of standardization leads to under-reporting of prevalence and difficulties in comparing methods. An improved gold standard is recommended that incorporates standardized use of the method of known addition (i.e., split/spike) to account for differences in egg recovery efficiencies from different environmental matrices. To overcome limitations of current methods, we investigated properties of Ascaris eggs that could lead to faster and more reliable egg concentration, we developed an algorithm for automated counting of Ascaris eggs in wide field microscopy (Chapter 2), and we developed an assay for determining viable eggs based on amplification of mRNA within eggs (Chapter 3).

Advisor: Criddle Craig 
Luby Stephen
Spormann Alfred M. 
Tang Sindy (Sindy K.Y.)
Quantitative analysis of Listeria monocytogenes invasion and spread in epithelial cells

Together, epithelial cells create the intestinal epithelium, a selectively permeable barrier that is the home and target of many microbes. One such microbe is the ubiquitous foodborne pathogen Listeria monocytogenes, which breaches the intestinal epithelium during an oral infection. L. monocytogenes first invades the cytoplasm of a host epithelial cell, which allows the bacterium to polymerize actin and create comet tails to drive its own motility and spread to neighboring epithelial cells. In this work, we focus on two steps of the L. monocytogenes intracellular life cycle: invasion and cell-to-cell spread. First, we demonstrate that the canonical receptor E-cadherin, which creates a physical link between the bacterium and filamentous actin, serves primarily as an adhesive to mediate invasion. Indeed, the minimum requirement for bacterial invasion is the presence of the extracellular domain of E-cadherin. Next, we show by simulation and live microscopy that L. monocytogenes cell-to-cell spread is heterogeneous as it proceeds by way of two populations: local spreaders and pioneers. Our data support the model that pioneers spread directly to non-neighboring cells via long bacterial-mediated host cell protrusions tens of microns long. We also use simulations to show that the combination of local spreaders and pioneers allows L. monocytogenes to more successfully create a persistent infection in the intestinal epithelium. Finally, we explore the use of human intestinal enteroids as a new model system to study L. monocytogenes pathogenesis in intestinal epithelial cells. Specifically, we show that L. monocytogenes can invade human enteroids via a mechanism independent of E-cadherin/internalin A, which differs from findings made in transformed epithelial cell lines.

Keywords: Biochemistry.
Advisor: Theriot Julie 
Amieva Manuel 
Rohatgi Rajat
Yeh Ellen
Quantum error correction and spacetime

Quantum error correction (QEC) is a branch of quantum information theory, originally invented to protect hypothetical quantum computers against realistic sources of noise. QEC has enjoyed significant success within the paradigm of computation, but the ideas and techniques of quantum error correction have also been effective in tools many fields of physics. In this thesis, we will shed light on the way in which QEC manifests outside of the usual computational paradigm and informs other areas of physics. We'll focus on the role of QEC in quantum gravity, spacetime, and high energy theoretical physics. We start with the general problem of quantum information replication in spacetime, and we show that information replication is possible if and only if transmission of the quantum information does not result in cloning of quantum information or faster-than-light communication. We then study the role of quantum error correction in quantum gravity, specifically within a gauge-gravity duality known as AdS/CFT. We establish a new formula for mapping observables on either side of the duality, showing that the so-called bulk-to-boundary map defines an approximate quantum error correcting code. Motivated by the study of entangled states dual to multi-boundary wormholes in AdS/CFT, we then turn our attention to characterizing the states that can arise from the euclidean path integral in three-dimensional Chern-Simons theories. We study U(1) level k and SO(3) level k Chern-Simons theories on euclidean 3-manifolds with torus boundaries. For the abelian U(1) theory, we find that the set of states that can be prepared exactly coincides with the set of stabilizer states, which are characterized by quantum error correcting codes. For the non-abelian SO(3) theory, we find that any state can be prepared to arbitrary precision, giving rise to a notion of state universality. We conclude with some final observations to support the idea that entanglement gives rise to the connectedness of spacetime. We study the partial transpose of the thermofield double (TFD) state geometrically, and we demonstrate that local time reversal (which is unitarily equivalent to partial transpose) leads to inconsistencies in the connected spacetime dual to the TFD state.

Keywords: Physics.
Advisor: Hayden Patrick (Patrick M.)
Hartnoll Sean
Shenker Stephen Hart
Racial disparities in school funding, academic achievement, and teacher perceptions of student behavior

In this dissertation, I examine the role of segregation and racial congruence between teachers and students on three different educational outcomes. The first paper examines teacher perceptions of student behavior as a function of racial similarity between teachers and students. The second paper estimates partial associations of between-district segregation and racial disparities in school district revenue. The third paper studies the effect of within-district segregation on racial disparities in academic achievement. Together, these papers deepen our understanding on the causes and correlates of racial disparities in education.

Keywords: Education.
Advisor: Reardon Sean F. 
Dee Thomas S. (Thomas Sean) 
Loeb Susanna
Radiation absorption by inertial particles in a turbulent square duct flow [electronic resource]

Particle-based solar receivers pose an interesting engineering challenge because of the coupled interactions between particle motion in a turbulent flow, radiation transmission and absorption through a random media, and convective heat transfer between the gas and solid phases. In a particle solar receiver, the absorbing wall of a conventional receiver is replaced with a transparent window and small particles dispersed within the working fluid absorb the radiation. This can increase the surface area available for heat transfer to the fluid, reduce radiation losses, and improve system efficiency. However, nearly all studies on particle solar receivers ignore the effect of particle clustering on radiation absorption and the gas temperature rise. In this work, the radiation absorption by preferentially concentrated particles in a turbulent square duct flow was studied experimentally. The turbulent flow of air was laden with small Nickel particles and exposed to monochromatic, infrared radiation over a streamwise length of several duct widths. Measurements were made of the particle phase statistics, mean and fluctuating radiation transmission, and mean and fluctuating gas temperature rise. Simplified heat transfer and radiation transmission models were also developed to understand the basic physical principles and to provide comparisons to the experimental results.

Keywords: Mechanical Engineering.
Advisor: Eaton John K. primary advisor. Thesis advisor
Elkins Christopher A.
Iaccarino Gianluca advisor. Thesis advisor
Rain, Want, and War: Exploring the Conditions Under Which Desertification and Drought-Induced Scarcity Lead to Violent Conflict in the Sahel

Scholars have postulated that in sub-Saharan Africa, rapid population growth and increasingly frequent drought events induced by climate change may conspire in driving scarcity-based conflicts. Whether or not this actually occurs, and how, are particularly salient questions to answer in order to better predict and prevent such wars, as deleterious shifts in the global climate threaten to complicate and create a variety of social, political, and economic problems. This paper employs the comparative case study method in examining three Sahelian states that have suffered similar levels of drought over the past 60 years, yet varying degrees of conflict, in order to better understand under what conditions scarcity results in violence in the region. The cases, selected for their similarity in a variety of macro-level factors, are analyzed individually using elements of process tracing, and the findings are synthesized in the concluding chapter. Ultimately, this study finds that scarcity can be a strong factor contributing to the outbreak and perpetuation of conflict in these states, but has never led to organized and widespread fighting where few elements of conflict had previously existed. It is particularly when the political consequences of drought compound preexisting grievances in an environment of strong ethnic affiliation, with few religious and geographic cross-cutting cleavages, that there is the potential for drought-induced scarcity to drive war. The paper concludes by calling for a departure away from studying the climate-conflict nexus through the lens of large-n statistical studies seeking generalizable theories, which disregard local nuances that are critical to understanding a country’s individual circumstances and trajectory.

Keywords: Center for International Security and Cooperation
Thesis
Advisor: Blacker Coit D.
Rational and combinatorial approaches to engineering a multi-epitopic antagonist of the urokinase receptor

The urokinase receptor (uPAR) has been established as a key driver of cancer metastasis, and an attractive target for therapeutic intervention of disease progression. Various uPAR antagonists have been developed and tested in pre-clinical models of cancer. However, they demonstrated limited efficacy due to their relatively low binding affinity and partial inhibition of uPAR function. To address these limitations, we applied rational and combinatorial engineering methods to generate a high-affinity antagonist capable of simultaneously inhibiting multiple cancer-promoting functions of uPAR. The resulting protein demonstrates potent inhibition of uPA-uPAR binding, as well as enhanced tumor targeting in vivo as proof of concept for further therapeutic development and testing.

Keywords: Bioengineering.
Advisor: Cochran Jennifer R. 
Giaccia Amato J.
Heilshorn Sarah