VictorJuiz/thesis huggingface dataset:
Revolution or Renaissance: The Effect of Chinese Leadership Transition on Foreign Policy

This thesis explores the impact of Chinese leadership transition on the contours of Chinese foreign policy. Much of the current literature on this topic has often dealt with Chinese leaders and their impact on foreign policy in silo, oftentimes forgetting that many of the foreign policy initiatives put forth by subsequent leaders have already been presented in the previous administration. This thesis explores the tenure of China’s three latest top leaders--Jiang Zemin, Hu Jintao and Xi Jinping--and compares the leadership of Xi against his two predecessors to assess how the process of leadership transition has had an impact on China’s foreign policy. By extension, this thesis also discusses and highlights the assumptions that we hold when discussing the Chinese political system and their implications for our understanding of the larger context of political leadership in China.

Keywords:  Stanford Global Studies
Stanford Global Studies
East Asian Studies
China
Leadership Transition
Foreign Outlook
Thesis
Advisor: Miller Alice L.
Ring-opening metathesis polymerization of substituted cyclopropenes

Life would not be possible without precise macromolecular sequence control. The ability of biological systems to encode information, transmit instructions, and catalyze chemical reactions relies on the proper ordering of monomeric units. While our synthetic capabilities may trail those nature has developed through billions of years of evolution, continued advances in polymer science have allowed ever greater control over polymer microstructures. Specifically, living polymerization techniques, such as ring-opening metathesis polymerization (ROMP), have given us the tools to synthesize polymers with defined molecular weights and narrow molecular weight distributions. While ROMP is typically driven by the release of ring strain, surprisingly little research has been performed on the polymerization of cyclopropenes (CPEs), the monocyclic olefin with the highest ring strain. We believed that the high strain energy of this class of monomers along with the ability to tune the steric environment through strategic substitutions would result in unique reactivity and potential to control monomer sequences. In building a library of CPEs capable of ROMP, we discovered a unique class of CPEs that only singly added to Grubbs third generation catalyst followed by no further homopolymerization. We have used this behavior to develop a system for perfectly alternating ROMP with CPEs and low-strain cyclic olefins. Further investigations have shown that this technique can be extended to incorporate other low-strain cycles, allowing for functionalities to be directly incorporated into the polymer backbone. Additionally, with these molecules in hand, we have been able to incorporate single functional units into a polymer backbone by addition of precisely one equivalent of monomer relative to catalyst. At first using this technique to synthesize telechelic polymers, we have successfully optimized this system to allow the incorporation of exactly one monomer into a ROMP polymer at any defined location along the backbone, giving unprecedented control over polymer sequence using via solution chemistry.

Keywords: Chemistry.
Advisor: Xia Yan
Burns Noah
Waymouth Robert M.
Risky hearts : Nigerian marketcraft in the global south

Since the 1990s, bustling markets across Asia and the Middle East have seen an uptick of thousands of African merchant travelers. This dissertation traces how these trans-continental manufacturing and commercial landscapes have been transformed by a key set of actors - a young mercantile generation from the massive petrostate of Nigeria. Drawn from 18 months of ethnographic fieldwork based primarily in the Nigerian megacity of Lagos, as well as eastern Nigeria and the contemporary African trade sites of Dubai (United Arab Emirates), Istanbul (Turkey), and Guangzhou (China), the dissertation analyzes how such south-south mobilities have transformed the politics of commercial space and nationalist imaginaries. First, the dissertation argues that such far-flung commercial mobilities are underpinned by highly decentralized and monopoly-resistant transnational market formations in Nigeria that are defensive against corporate and non-black foreign actors. I employ the concept of marketcraft to highlight the centrality of processes of security and protection in market formation, which are shaped by the affective orientations, ethics, and historical contingencies of the actors and politics that create them. Second, the dissertation examines how Nigerian merchants engage with ethno-regional politics and neo-secessionism upon return and how transnational south-south diasporic formations have transformed Nigerian social imaginaries and discourses of postcolonial political and economic sovereignty.

Keywords: Anthropology.
Advisor: Yanagisako Sylvia Junko
Ferguson James
Hansen Thomas Blom
RNA structural regulation of reverse transcription initiation in HIV [electronic resource]

The process of reverse transcription in HIV is a crucial early step in the viral replication cycle and must take place before infection is complete. During this process, the viral single-stranded RNA genome is reverse transcribed into double-stranded DNA for incorporation into the host cell genome. HIV drug treatments that inhibit reverse transcription have been highly successful in treating and preventing infection. Understanding how this process is regulated on a molecular level is crucial for understanding how reverse transcription defects prevent viral replication. This work presents a series of biochemical and biophysical studies on the macromolecular components involved in regulating reverse transcription initiation in HIV.

Keywords: Biophysics.
Advisor: Puglisi Joseph D. primary advisor. Thesis advisor
Bryant Zev David advisor. Thesis advisor
Kirkegaard Karla advisor. Thesis advisor
Puglisi Elisabetta advisor. Thesis advisor
Robotic mobility on small solar system bodies : design, control, and autonomy

In this thesis, we investigate the mobility challenges associated with robotic exploration of small solar system bodies, such as comets and asteroids. We open with a discussion on the surface environment of small bodies, and in particular, how their extremely weak gravity motivates hopping as a promising form of locomotion for long-distance traverses. We then propose an adaptable rover architecture called ``Hedgehog''---a minimalistic, internally-actuated, hopping rover designed for targeted mobility in such low-gravity environments. By applying internal torques to three mutually-orthogonal flywheels, the rover's chassis rotates, giving rise to ground reaction forces and various motion primitives, including long-range hopping, short precise tumbling, and small pose adjustments. We propose various models for analyzing the dynamics of these motion primitives and derive control laws for achieving desired motions. We then discuss various methods for conducting experiments in a reduced-gravity environment, including a custom six-degree-of-freedom laboratory test bed and parabolic flights. We validate our control laws in these test beds and demonstrate unprecedented motion accuracy for internally-actuated hoppers. Finally, we broaden our focus to general hopping platforms and consider various algorithmic tools for autonomous exploration. Specifically, we develop a suite of tools for motion planning, localization, and traversability analysis, with a careful attention on the various sources of model uncertainty and the complex dynamics of hopping trajectories. Despite the stochastic nature of bouncing dynamics, we demonstrate through high-fidelity simulations that a hopping rover can efficiently traverse highly irregular bodies that would otherwise be inaccessible to traditional rovers.

Keywords: Mechanical Engineering.
Advisor: Cutkosky Mark R. 
Pavone Marco
Kochenderfer Mykel J.
Robust learning : information theory and algorithms

We study the problem of robust learning in the presence of outliers when the dimensionality of the underlying space is large. We first develop a criterion, called resilience, under which robust learning is information-theoretically possible. We show that resilience gives tight bounds in many cases, and study its finite-sample behavior. Next, we turn our attention to efficient algorithms. We present two classes of algorithms---based on moment estimation and duality, respectively---that provide robust estimates as long as certain moments of the data are bounded. We apply these algorithms to mean estimation, stochastic optimization, and clustering.

Advisor: Liang Percy 
Duchi John 
Valiant Gregory
Role of CD47 in Clonal Expansion of Vascular Smooth Muscle Cells in Atherosclerosis

Background
Cardiovascular disease claims more lives each year than all forms of cancer combined, and atherosclerosis, a form of cardiovascular disease, is the process of fatty deposit build-up in arterial cells to form atherosclerotic lesions. Recent studies show that vascular smooth muscle cells (SMCs) act as a cardiovascular risk factor independent of cholesterol levels, yet not much is known because SMCs tend to lose their lineage-specific markers during plaque progression, which results in the underestimation of SMC contribution to plaque expansion using traditional histology methods. For the same reason, little is known about SMC biology in atherosclerosis and in developing therapeutics to treat diseased SMCs in the plaques.
Methods and Results
To overcome this problem, a unique SMC lineage-tracing murine model carrying a "Rainbow" reporter was developed. When exposed to tamoxifen, this mouse underwent gene recombination and randomly expressed one of three colors - yellow, blue or red - exclusively in SMCs such that each cell and its descendants expressed the same color. Mice containing the "Rainbow" reporter were crossed with Apolipoprotein E knockout (ApoE-/-) mice, a murine model of atherosclerosis, to generate "Rainbow mice" for studying SMCs during atherosclerosis. Use of this model showed that SMCs underwent clonal expansion in the plaque. Flow cytometry analysis subsequently showed that diseased SMCs in the plaque from Rainbow mice expressed higher levels of the "don't eat me" molecule CD47 compared to that of healthy SMCs. SMCs from the plaque were also sorted to feed the phagocytes, and CD47high SMCs were found to be more resistant to efferocytosis. Then, Rainbow mice were fed with 18 weeks of high fat diet to induce atherosclerosis and were treated with control IgG or anti-CD47 antibody. The anti-CD47 antibody treated mice showed significantly reduced plaque size and SMC clonal expansion.
Conclusion
CD47 overexpression facilitated SMCs clonal expansion by allowing them to escape from efferocytosis. Ultimately, the use of an anti-CD47 strategy was potentially beneficial to help remove diseased SMCs from the plaque to decrease the size of the established plaque and lower the risk of heart attack and stroke.

Keywords:  Department of Biology
Department of Biology
Stanford University
cardiovascular medicine
molecular biology
atherosclerosis
plaque
smooth muscle cells
clonal expansion
Thesis
Advisor: Leeper Nicholas
Jones Patricia
Mudgett Mary Beth
The role of contacts and interfaces on the performance of perovskite solar cells

With business as usual, our planet is expected to warm by over 4°C in the next 80 years. Those four degrees mean more chaotic weather, increased food scarcity, unprecedented flooding, and the many other impacts of global warming. To curtail these impacts requires a rapid expansion of carbon-free and renewable energy, and one promising source of that energy is perovskite solar cells -- a novel photovoltaic technology that despite its nascence has already surpassed power-conversion efficiencies of 22%. The halide perovskites of focus for solar applications are unique in their tolerance of many ionic defects. This property results in mixed electronic-ionic conduction, that requires new design rules and new models of understanding for perovskites used in solar cells. This work presents advances in understanding interfaces and optimizing contacts with the aim of closing the gap between the thin film properties of perovskites and their solar cell device efficiencies. First, I demonstrate how the presence of mobile ionic defects in perovskite solar cells changes the nature of perovskite-electrode interfaces, and therefore the impact of carrier-selective contacts on device performance. Translating this understanding of the impact of contact materials into contact design, I next present my results combining thermally evaporated organic molecules and atomic layer deposited vanadium oxide, to develop a contact with increased optical transparency and thermal stability for perovskite-silicon tandem solar cells. Finally, expanding on the impacts of ionic defects, I present a new understanding of photo-induced trap formation -- an energy loss-pathway that currently limits the power-conversion efficiency of many perovskite solar cells -- highlighting interfacial treatments as a pathway towards trap passivation and improved efficiency. Together, this work highlights the dynamic and impactful nature of perovskite interfaces, and how, by optimizing them, we can continue to advance the already remarkable efficiency of perovskite solar cells.

Keywords: Materials Science and Engineering.
Advisor: McGehee Michael
Lindenberg Aaron Michael 
Salleo Alberto
Role of Frizzled Conformational Changes and Membrane Composition in the Frizzled-Dishevelled Interaction

The Wnt signaling pathway plays an essential role in embryonic development and the regulation of many physiological processes. Defects in Wnt signaling can contribute to a variety of diseases including cancer, diabetes, and familial exudative vitreoretinopathy, among others. In β-catenin-dependent “canonical” Wnt signaling, Wnt binds to a complex of the transmembrane receptors Frizzled (Fzd) and LRP5/6, which induces recruitment of the cytoplasmic scaffold protein Dishevelled (Dvl). Very little is known about the mechanism and function of Dvl recruitment to Fzd. It is unclear whether the PDZ or DEP domains of Dvl bind Fzd, and how local membrane environment may affect Fzd-Dvl binding. A major limitation of the previous work on Fzd-Dvl interaction is the use of Fzd peptides instead of purified protein. Here, we use purified Dvl2 and Fzd4 protein to better understand how the Fzd-Dvl interaction drives Wnt signaling. We show that both purified Dvl2 DEP and PDZ bind to purified Fzd4 in fluorescence polarization studies. To our knowledge, this is the first demonstration of Fzd-Dvl binding using purified full-length Fzd protein. We also aim to determine the effects of Fzd conformational changes on Dvl recruitment. We design Fzd mutants using known familial exudative vitreoretinopathy (FEVR) mutants and a homology model of Fzd4 based on the crystal structure of full-length Smoothened. Using a cell-based signaling assay, we provide evidence that Fzd undergoes a conformational shift during Wnt activation and that this activating conformation is necessary for β-catenin signaling. The abrogation of Wnt signaling seen in Fzd with cytoplasm-facing mutations provides additional support for the existence of a cytoplasmic docking site on Frizzled. Lastly, we investigate the effect of the local lipid environment on Fzd-Dvl binding. We show that purified Dvl2 PDZ does not interact with lipid nanodiscs, and that purified Dvl2 DEP and PDZ do not interact with liposomes. Our work is an important first step in elucidating the mechanism of Fzd-Dvl recruitment and activation of downstream signaling effectors.

Keywords:  Department of Biology
Wnt signaling
Frizzled
Dishevelled
Structural Biology
Biochemistry
Thesis
Advisor: Weis William
Stearns Tim
The role of pleiotrophin in glioma invasion of the subventricular zone [electronic resource]

The lateral ventricle subventricular zone (SVZ) is a frequent site of high-grade glioma (HGG) spread, and tumor invasion of the SVZ is a predictor of a worse clinical prognosis. A range of HGG types invade the SVZ stem cell niche, including both adult glioblastoma and pediatric high-grade gliomas such as diffuse intrinsic pontine glioma (DIPG). The cellular and molecular mechanisms mediating this frequent invasion of the SVZ are poorly understood. Here, we demonstrate that neural precursor cell (NPC):glioma cell communication underpins the propensity of glioma to colonize the SVZ. SVZ NPCs secrete chemoattractant signals toward which glioma cells home. Biochemical and proteomic analyses of factors secreted by SVZ NPCs revealed a discrete list of candidate proteins. Necessity and sufficiency testing implicated the neurite outgrowth-promoting factor pleiotrophin, along with three required binding partners (secreted protein acidic and rich in cysteine (SPARC), SPARC-like protein 1, and heat shock protein 90B), as key mediators of this chemoattractant effect. Pleiotrophin protein expression is strongly enriched in the SVZ, and knockdown of pleiotrophin expression starkly reduced glioma invasion of the SVZ in the adult murine brain. Pleiotrophin, in complex with the three binding partners, activated the Rho/Rho kinase pathway in DIPG cells, and inhibition of Rho kinase resulted in decreased DIPG invasion toward SVZ neural precursor cell-secreted factors. These findings demonstrate a pathogenic role for neural precursor cell:glioma interactions and potential therapeutic targets to limit glioma invasion.

Advisor: Monje-Deisseroth Michelle
Buckwalter Marion
Palmer Theo advisor. Thesis advisor
Sage Julien advisor. Thesis advisor
Role of the Beta-2 Adrenergic Receptor in Controlling Inflammatory Dynamics After Ischemic Stroke

Ischemic stroke is one of the leading causes of death and disability around the world. Stroke triggers inflammation in the brain, which plays a critical role in the eventual outcome of the infarct. This neuroinflammation is a dynamic process, involving microglia (the brain resident macrophages) in addition to several peripheral immune cells subsets that enter the brain from the bloodstream after stroke. Microglia and the monocyte-lineage cells that localize to the brain post- stroke highly express the beta-2 adrenergic receptor (β2-AR). Although studies have demonstrated that β2-AR signaling alters the activity of immune cells after stroke, the specifics of this modulation remain unclear. Using a mouse model of stroke, we examined the effects of stimulating or blocking this receptor with β2- AR affecting drugs on brain inflammation and infarct outcome. In addition, in order to better characterize the role of the β2-AR specifically for the microglia and invading immune cells, we created mice that had the receptor knocked out selectively in Cx3Cr1 expressing cells. Our experiments demonstrated that the stimulation of β2-AR on microglia and other invading immune cells decreased neuroinflammation by decreasing immune cell morphologic activation, rate of proliferation, and expression of pro-inflammatory cytokines. This limited inflammation resulted in an increased stroke size. In contrast, β2-AR blockade increased the expression of pro-inflammatory cytokines and increased the overall reactivity of immune cells in the stroke region. Interestingly, however, we also demonstrated that a certain degree of β2-AR activity helps spur cell proliferation. These findings elucidate some of the specific effects of β2-AR activity after stroke, allowing us to better understand the neuroinflammatory process of stroke and to identify new potential therapeutic techniques.

Keywords:  Department of Bioengineering
bioengineering
neuroscience
neuroinflammation
stroke
post-stroke
adrenergic signaling
beta-2 adrenergic receptor
Thesis
Advisor: Buckwalter Marion
Covert Markus
Roles of AtACINUS and AtPNN in alternative splicing and developmental transitions in Arabidopsis

Seed germination and flowering are two major developmental transitions in the life cycle of plants; their precise control is crucial for species survival in nature and involves complex regulatory mechanisms. Here, we report that the Arabidopsis AtACINUS and AtPNN proteins redundantly play key roles in regulating seed germination and flowering through alternative splicing (AS) and transcriptional regulation of target genes, respectively. The acinus pnn double mutant lacking both AtACINUS and AtPNN, which share sequence similarity only within a protein-protein interaction domain, showed severe growth defects including dwarfism, delayed seed germination and late flowering, while neither acinus nor pnn single mutant showed obvious morphological defect. Transcriptomic analysis of acinus pnn showed high levels of the flowering repressor FLC and RNAs responsive to abscisic acid (ABA), the hormone required for seed dormancy. The acinus pnn mutant also showed intron retention in many transcripts, including those encoding two negative regulators of ABA signaling: ABA-HYPERSENSITIVE 1 (ABH1) and HYPERSENSITIVE TO ABA 1 (HAB1). Consistent with these alterations of ABA-related transcripts, the acinus pnn mutant was hypersensitive to ABA treatment. Proteomic analyses indicate that AtACINUS is associated with the spliceosome and a large number of RNA-binding/processing proteins. AtACINUS associates with the RNAs of ABH1 and HAB1 and the promoter DNA of FLC in vivo, supporting its direct involvement in regulating AS and transcription. Our study uncovers important roles of AtACINUS/AtPNN in controlling key developmental transitions through dual functions in transcription and AS of target genes in Arabidopsis.

Keywords: Biology.
Advisor: Bergmann Dominique 
Wang Zhi-Yong
Gozani Or Pinchas 
Mudgett Mary Beth
Rural Bank Expansion, Human Capital Development, and Intra-household Bias in India

In the 1970s and 1980s, the Indian Central Bank implemented an ambitious rural branch expansion program to bring bank access to unbanked areas of the nation. Previous research has found that this bank expansion program was effective in alleviating poverty in terms of state-level headcount ratios and in increasing rural usage of formal financial services, though no studies have examined human capital outcomes and the differential effects of this program on children of different gender or birth order. In this paper, I use an instrumental variables strategy to attempt an evaluation of the bank expansion program's effects on health and education outcomes. I find that the program had significant effects in reducing infant and child mortality rates at the state level, particularly for firstborns and male children. I find evidence that the program also had significant effects on state-level enrollment rates, without evidence of differential effects by student gender.

Keywords:  Department of Economics
Department of Economics
economic development
Regional Rural Banks
infant mortality
child mortality
gender bias
birth-order bias
education
Thesis
Advisor: Dupas Pascaline