VictorJuiz/thesis huggingface dataset:
Essays on the political economy of drug related violence in Mexico [electronic resource]
Keywords: Political Science.

My doctoral dissertation aims to explain patterns of drug-related violence within Mexican municipalities during president Calderón's administration (2006-2012). It consists of three essays, each of them uncovering a causal relationship in the complex interaction between law enforcement authorities, criminal groups, and civil society. In the first paper, I provide a characterization of drug-related violence and estimate the associated costs of this type of violence on the economic activity. In particular, I propose domestic electricity consumption and night lights luminosity as indicators of local economic activity, and use synthetic controls to evaluate the effect that inter-narco wars have had on local economies. I found that municipalities that observed dramatic spikes in violence between 2000 and 2012 significantly reduced their energy consumption and use of night lights in the years after the turf war started. The second paper estimates the causal effect on drug-related violence of the targeting for arrest of the core leadership of criminal networks. This paper is co-authored with Beatriz Magaloni, Alberto Diaz-Cayeros, and Gabriela Calderón. To estimate effects that are credibly causal, we use a difference-in-differences specification in combination with the synthetic control methodology. We find evidence that captures or killings of drug cartel leaders have exacerbating effects not only on DTO-related violence, but also on homicides that affect the general population. The third paper uncovers political factors affecting the success of government interventions in fighting organized crime at the subnational level. In particular, I assess whether the party affiliation of local authorities have a causal effect on the frequency and intensity of the confiscation of handguns and rifles. The empirical strategy in this paper uses a difference-in-differences specification and a Regression Discontinuity Design on a subsample of local governments elected in close elections. I find that the juxtaposition of a mayor and a governor from the same party as the president's party, Partido Acción Nacional (PAN), is related to an increase in both the number of guns seized in a municipality and the probability of a monthly seizure. Finally, the last section of my dissertation is a technical annex where I describe the construction of a measure of drug-trafficking "connectivity" that I use throughout the dissertation. In particular, I estimate optimal road routes from each municipality to the closest border crossing with the United States. Using optimal routes and drug seizures from previous administrations, I estimate the approximate volume of marijuana, cocaine, opium-heroin, and methamphetamines, that transits through each municipality. The second part of the annex shows that the measure of drug-trafficking "connectivity" is highly predictive of increases in drug-related violence observed during Calderón's administration.
Essays on the role of advertising in product markets [electronic resource]
Keywords: Business.

This thesis studies the role of advertising in product markets and the mechanisms by which advertising affects consumers' purchase decisions. The first chapter explores the effects of e-cigarette advertising on demand for traditional cigarettes and contributes to the current policy debate as to whether e-cigarette TV advertising should be banned, as is TV advertising for tobacco cigarettes. To analyze this question, I leverage access to county-level sales and advertising data on cigarettes and related tobacco products, along with detailed data on the consumption behavior of a panel of households. Using both descriptive and structural methods, I show evidence that e-cigarette advertising reduces demand for tobacco cigarettes. In a policy-relevant counterfactual analysis, I predict that an e-cigarette advertising ban would increase demand for cigarettes by 3%, suggesting that a ban on e-cigarette advertising may have unintended consequences. Chapter 2, which is a joint project with Harikesh Nair and Pedro Gardete, explores new opportunities for ad targeting based on the past consumption of both products and ads. The standard paradigm in the empirical literature is to treat consumers as passive recipients of advertising, but this paradigm ignores the fact that consumers may actively choose their consumption of advertising. Becker and Murphy (1993) recognized this aspect of demand for advertising and argued that advertising should be treated as a good in consumers' utility functions, thereby effectively creating a role for consumer choice over advertising consumption. They argued that in many cases demand for advertising and demand for products may be linked by complementarities in joint consumption. We analyze an unusually rich dataset that links the TV ad consumption behavior of a panel of consumers with their product choice behavior over a long time horizon. In a series of descriptive analyses, we show that the data suggests an active role for consumer choice over ads and for complementarities in joint demand. To interpret the patterns in the data, we fit a structural model for both products and advertising consumption that allows for such complementarities. Interpreting the data through the lens of the model enables us to precisely characterize the treatment effect of advertising under endogenous non-compliance and assess the returns to targeting advertising based on endogenous past consumption. To illustrate the value of the model, we compare advertising, prices and consumer welfare to a series of counterfactual scenarios motivated by the "addressable'' future of TV ad-markets in which targeting advertising and prices on the basis of ad-viewing and product purchase behavior is possible. We find that both profits and net consumer welfare may increase, suggesting that it may be possible that both firms and consumers become better off in the new addressable TV environments.
Evaluating Potential Tumor Stem Cell Populations in Diffuse Intrinsic Pontine Glioma (DIPG)
Keywords:  Department of Biology
Biology
DIPG
Thesis

Diffuse Intrinsic Pontine Glioma (DIPG) is a brain tumor that originates in the pons of the brainstem. This devastating cancer most prominently affects children between the ages of 5 and 7 years of age, and comprises approximately 10-15% of all pediatric brain tumors. Recent studies have identified genomic alterations thought to drive development of DIPG, but the molecular effectors of tumorigenesis remain unclear.
Single cell qPCR experiments performed in the Monje Lab at Stanford have identified distinct subpopulations of cells from DIPG xenografts that exhibit distinct transcriptional profiles in contrast to other regions of the tumor. We hypothesized that this transcriptionally defined subpopulation of cells may act as cancer stem cells in DIPG. To further clarify the role of these subpopulations in DIPG tumor development, this project evaluated their potential to act as tumor-initiating stem cell populations.
To investigate whether this subpopulation could be acting as a tumor stem cell driving the initiation of DIPG, this population was screened for its ability to form neurospheres in vitro. Stem cell frequency estimates were calculated, and it was determined that cells seeded from the subpopulation of interest exhibited statistically equivalent stem cell frequencies when compared to cells from other regions of the same tumor.
Further, to evaluate whether the subpopulation of interest could act as a stem cell population contributing to the initiation of tumors, I monitored the expression profile maintenance of this population in culture over time. This analysis revealed that, over the course of several passages, the expression profile of this subpopulation is only weakly maintained.
Finally, to further characterize the potential for this subpopulation to act as a tumor-initiating population, it was imperative to evaluate its proliferative capacity as compared to other regions of the same tumor. In the presence of growth factors, the subpopulation of interest proliferated at a higher rate than cells from other regions of the same tumor.
With the identification of a subpopulation that shows substantial growth capacity both in vitro and in vivo, I tested if this population is sensitive to pharmacological inhibition in hopes of identifying a viable therapeutic target for DIPG. Crenolanib, a PDGFR-specific RTK inhibitor, was screened for its ability to kill bulk DIPG cells. However, it appears that by itself, or in conjunction with another promising drug, Panobinostat, Crenolanib is ineffective at killing bulk DIPG cells.
Altogether, this data suggets that the subpopulation of interest is not representative of a tumor-initiating stem cell population. However, it might actually be acting as a more differentiated transient amplifying population that doesn’t initiate the tumor, but instead contributes to its rapid growth.
Evaluating School Counselors: Impact of Variation in Student-to-Counselor Ratio in Missouri Public High Schools
Keywords:  Department of Economics
Stanford Department of Economics
Guidance Counselor
School Counselor
Comprehensive Guidance and Counseling
Student-toCounselor Ratio
Missouri
High School
School Discipline
Academic Achievement
Thesis

In this paper, I analyze how variation in the student-to-counselor ratio impacts student academic outcomes (such as graduation rates and test scores) and behavioral outcomes (such as disciplinary infractions and post-high school decisions). I use a fuzzy regression discontinuity approach to estimate the impact of variation in the student-to-counselor ratio in Missouri public high schools. I look at school-level data primarily from the Missouri Comprehensive Data System as well as the National Center for Education Statistics’ Schools and Staffing Survey (SASS) and Common Core of Data. I find that an additional high school counselor increases ACT scores in math and science by approximately 0.13 and 0.11 standard deviations respectively. An additional counselor has no statistically significant effect on overall graduation rates, but increases the graduation rate for Black and Native American students by approximately 8.5 and 7 percentage points respectively. An additional counselor has no statistically significant effect on college enrollment rates, but increases post-graduate employment rates by approximately 1.5 percentage points. Finally, an additional counselor predicts a 0.67 percentage point increase in overall disciplinary infractions.
Evaluation of anti-CD47 Antibody (Hu5F9-G4) as a Therapeutic in Human Pancreatic Tumor Mouse Model
Keywords:  Department of Biology
Biology
cancer
antibody therapy
Thesis

CD47 is a cell surface receptor over expressed on cancer cells that acts as a “don’t eat me” signal and inhibits the engulfment of cancer cells by phagocytes. This study explores the role of a novel monoclonal antibody, Hu5F9-G4, that blocks CD47’s interaction with its ligand SIRPα, in the phagocytosis of pancreatic cancer cells. Specifically, the study examined the therapeutic efficacy of the anti-CD47 (Hu5F9-G4) antibody alone and in combination with two EGFR targeting antibodies, cetuximab and panitumumab, in patient-derived pancreatic ductal adenocarcinoma (PDAC) xenografts. We found that the anti-CD47 antibody slowed tumor growth, but did not increase survival noticeably. When used in combination with Panitumumab and cetuximab, the anti-CD47 antibody lead to less tumor growth in vivo than treatment with panitumumab, cetuximab, or PBS alone did. While the combination treatment significantly reduced tumors, it only marginally increased survival over single agent anti-EGFR antibodies. We conducted protein expression profiling of EGFR and CD47 expression by FACS and in vitro phagocytosis assays, to determine the in vitro response of the cancerous cells to the anti-CD47 antibody Hu5F9G4, the anti-EGFR antibodies cetuximab and panitumumab, and the combination of these antibodies. The examination of the expression levels of CD47 and EGFR in the BxPC3 cell line showed the expression of both cell surface markers. The phagocytosis assay showed that blockade by Hu5F9-G4 alone and in combination with other antibodies in vitro enables phagocytosis of the cancer cells. The combination treatment did not yield greater phagocytosis than the individual anti-EGFR treatments. This study is important because it is the first to demonstrate in the solid tumor setting to demonstrate that an anti-CD47 antibody in combination with an anti-EGFR antibody is able to dramatically shrink tumors in animal models.
The evolutionary universe [electronic resource] : cosmology, society, and natural history in Britain, 1780-1860
Keywords: History.

This dissertation examines the development of evolution as a cosmic concept—that is, as a concept that people applied to both the physical transformations of the astronomical heavens and to everything else in the universe—across the eight decades preceding Charles Darwin's 'On the Origin of Species' (1859). The story I tell is centered in Britain, but with important roots in, and connections to, French and German natural philosophy. The language people used to refer to the concept of the transformation of organic and inorganic nature changed over the time period in question, of course, but it did so within a consistently universal paradigm that extended a single transformist law or principle to everything in the universe, from the transformation of nebular matter into solar systems, to the development of the earth, to the emergence and transformation of organic life on its surface, the progress of individuals and human societies, and even life in a spiritual world to come. This cosmic evolutionary paradigm was developed in the context of imaginative habits of thought associated with a historical movement known as Romanticism. The story of cosmic evolutionary thought is important for three reasons. First, it reveals the way in which evolution was a feature of nineteenth-century thought more generally, uncovering new avenues for historical research across domains of study. Second, it presents evolution not as the product of a few individual moments of genius, but as a rising tide of thought that saturated literary, religious, social, political, and natural philosophical life. Finally, our understanding of evolution in particular, and the scientific enterprise more generally, are transformed by a clearer recognition of the imaginative, Romantic roots of evolutionary ideas. The story of the cosmic evolutionists demonstrates the critical role of imagination in science, and particularly evolutionary, historical accounts of nature, while also examining the controversy that has accompanied it from the very beginning.
Examining the Effect of a Redox-Active Metallo-porphyrin on Staphylococcus Biofilms
Keywords:  Department of Biology
Biology
Biofilm
Infection
Antioxidant
Free Radical
Thesis

Background: Staphylococcus aureus is a leading pathogen and cause of orthopedic implant infections. S. aureus infections are often resistant to numerous antibiotic treatments and frequently grow in biofilm structures. Biofilms occur when microorganisms adhere to surfaces and grow in networks that are phenotypically different from planktonic counterparts. These differences make biofilms resistant to traditional antibiotic treatment. Biofilms actively modulate their redox environments suggesting the utility of a potent small molecule redox-active compound in treating biofilm infections.
Methods: S. aureus (ATCC 29213) biofilms were established and were then treated with either a potent redox-active metalloporphyrin MnTE-2-PyP (chemical name: manganese (II) meso-tetrakis-(N-methylpyridinium-2-yl) porphyrin) or phosphate-buffered saline (PBS). The matrix was quantified with crystal violet and confocal microscopy. An animal model was conducted using an S. aureus infected intramedually fixed femur fracture. This murine model ran over a two week time course and mice were treated with either no treatment, MnTE-2-PyP, antibiotic, or a combined therapy of antibiotic and MnTE-2- PyP. Femurs were collected at the experimental endpoint and were analyzed for CFUs.
Results: MnTE-2-PyP was found to significantly reduce the extracellular matrix in the in vitro studies. In the murine fracture model, combined MnTE-2-PyP -antibiotic treatment resulted in lower CFU/g bacteria counts in harvested femurs as compared with the other treatment groups.
Conclusions: Changes in redox environment seem to have significant effects on biofilm structure and robustness. Utilization of a redox-active metalloporphyrin in conjunction with antibiotics may be an effective therapeutic possibility in treating biofilm infections.
Examining the Implementation of Culturally Responsive Schooling in Karuk Ancestral Territory
Keywords: Karuk Tribe
Culturally responsive schooling
Native American
Karuk Tribe
teacher
Thesis

Exploring teacher approaches to culturally responsive schooling (CRS) among schools serving Indigenous youth is critical, given low achievement rates and the sociohistorical context of Indian education in the United States. The purpose of the study was to explore this aspect of curricular implementation in the context of the Karuk Tribe’s pilot program of curriculum, Nanu’ávaha. Interviews examined teachers' perceptions of the ways in which they feel that the different elements of Nanu'ávaha and their associated training have prepared them to implement culturally responsive curriculum and schooling methods. Data and thematic analysis supported the use of formal training methods to prepare teachers for curricular programs and the sociopolitical context of Native communities and classrooms. Results also supported a need for increased support from tribal programs to increase CRS implementation. Conclusions include an affirmation of the need for CRS in classrooms serving Native youth and a responsibility on part of educators to display commitment in that process. Limitations, directions for future research, and implications for future Karuk tribal education programs are discussed.
Exclusion in the era of multicultural recognition [electronic resource] : cultural heritage, Afro-descendants, and the politics of diversity in Colombia and Brazil
Keywords: Anthropology.

Colombian and Brazilian bureaucrats readily agree that recognizing their nation's cultural heritage and ethno-racial diversity is inherently good. My dissertation questions this premise and examines the unexpected and often-harmful consequences that, in practice, heritage declarations have on minorities. Based on multi-sited ethnographic research in Colombia, Brazil, and UNESCO headquarters in France, this dissertation examines how polices that recognize Afro-descendant groups can also increase their economic and political marginalization. This dissertation focuses on two formerly enslaved Afro-descendant communities, San Basilio de Palenque in Colombia, inscribed on UNESCO's "Representative List of the Intangible Cultural Heritage of Humanity, " and Quilombo dos Palmares in Brazil, declared as a National Heritage Site. Using ethnographic methods including participant observation, semi-structured interviews, and archival analysis, my research traces a series of unintended outcomes wrought by cultural heritage policies on the ground and critically considers the structural limitations that characterize these kinds of initiatives. Regardless of their positive aims, I argue that the very policies intended to proffer empowerment to some, actually exacerbate inequality for others. The ethnographic evidence I collected between 2009 and 2013 shows that while heritage recognition brings visibility to the cultural practices of Afro-descendants, it also masks the deep-seated struggles of minorities and cements categorical boundaries between different ethnic groups. This dissertation highlights the paradox of heritage recognition policies, which tend to be understood as part of a broader agenda to promote ethno-racial diversity. Though these policies strive to expand Afro-descendants' social, political, and symbolic membership as citizens of multicultural nations, they end up also entrenching exclusion, buttressing elitism, and reinforcing inequality within and between communities of African descent. My ethnographically based insights are helpful for examining the real-time effects of multicultural policies on the ground, as well as informing a largely theoretical debate on how to value cultural difference. Ultimately, my dissertation contributes to develop new theory and methods for evaluating the impacts of heritage declarations on ethno-racial minorities. By elucidating the limits of cultural heritage recognition to provide reparation for Afro-descendants, my research is of crucial importance for wider debates regarding politics of diversity in the Global South.
Exemplary teachers of culturally and linguistically diverse students [electronic resource] : what are the knowledge and skills that undergird their classroom practices?
Keywords: Education.

This study identifies and characterizes the knowledge and skills exhibited by three exemplary teachers of culturally and linguistically diverse students in bilingual elementary classrooms. Numerous studies have demonstrated low levels of educational achievement for culturally and linguistically diverse student such as Latino English Learners yet research has also shown that teachers can be a powerful factor in students' learning and achievement. Teachers often cite lack of skills and preparation needed to effectively teach this population of students effectively. This study identifies and describes the classroom practices of three first grade teachers that promoted academic achievement and acquisition of English. This study also explores how it is that these teachers believe they learned to be successful teachers as well as details their efforts to advocate for Latino ELs.
Experimental and numerical tools to investigate ringing in IC engines [electronic resource]
Keywords: Mechanical Engineering.

According to the International Energy Agency, mitigating greenhouse gas emissions to limit global temperature increase to 2 degrees Celsius will require efficient, combustion-based systems for light-duty transportation to take the place of conventional spark-ignited gasoline engines in the next 25 years. One of the barriers to high-efficiency combustion strategies such as homogeneous charge compression ignition (HCCI) is a phenomenon known as ringing, the formation of damaging pressure waves in the engine during the combustion process. Previous experimental results indicate that disruption of ringing is possible, to achieve high efficiency and high power density. Two tools to obtain spatially-resolved information during the ringing combustion process are the primary contributions described in this dissertation. A quasi-1D reacting compressible flow model captures the essential physics of the ringing phenomenon, to target experimental investigation and to interpret experimental results. To obtain spatially-resolved experimental data, an optically accessible engine capable of 250 bar peak pressure and Schlieren imaging was designed, manufactured, and demonstrated.
Exploring Dark Matter Bound During the Formation of the Solar System
Keywords: Wiser, Timothy
Wagoner, Robert
Dark Matter
Axion
Solar System
Thesis

We estimate the expected population density of Dark Matter bound to the solar system in a number of different limits in order to better inform direct detection searches. At Earth, we expect the population captured during the formation of the sun to be reduced by a factor of more than $10^{-4}$ from the initial background population, making it negligibly small. However, in the adiabatic limit we expect an enhancement of $10^{11}$ on the population of Dark Matter initially bound to the gas cloud which will collapse to form the sun, which could be a relevant population. The result is reproduced by treating the Dark Matter as a classical field. We expect distortions in this population during the lifetime of the Solar System due to Jupiter to be insignificant.