VictorJuiz/thesis huggingface dataset:
Investigating the switching mechanism of interfacial phase change memory
Keywords: Electrical Engineering.

Phase Change Memory (PCM) is a leading candidate for next generation data storage, but it typically suffers from high switching (RESET) current density (20--30 MA/cm2). Interfacial Phase Change Memory (IPCM) is a type of PCM using multilayers of Sb2Te3/GeTe, with up to 100× lower reported RESET current compared to the standard Ge2Sb2Te5-based PCM. Several hypotheses involving fundamentally new switching mechanisms have been proposed to explain the low switching current densities, but consensus is lacking. IPCM switching is investigated by analyzing its thermal, electrical, and fabrication dependencies. First, the effective thermal conductivity (∼0.4 Wm−1K−1) and thermal boundary resistance (∼3.4 m2KGW−1) of Sb2Te3/GeTe multilayers is measured. Simulations show that IPCM thermal properties account only for ∼13% reduction of current vs standard PCM and cannot explain previously reported results. Interestingly, electrical measurements reveal that IPCM RESET indeed occurs by a melt-quench process, similar to PCM. High deposition temperatures are shown to cause defects including surface roughness and voids within the multilayer films. Thus, the substantial RESET current reduction of IPCM appears to be caused by voids within the multilayers, which migrate to the bottom electrode interface by thermophoresis, reducing the effective contact area. These results shed light on the IPCM switching mechanism, suggesting that an improved control of layer deposition is necessary to obtain reliable switching. Finally, finite element simulations are performed to predict time and volumetric scaling trends of PCM switching. Usage of pulse widths beyond a few nanoseconds are shown to be essentially wasting energy due to the time scales of device heating and is experimentally verified. Finally, current densities are predicted to become worse at ultra-scaled dimensions (bottom electrode diameter < ~10 nm) due to thermal and current confinement problems.
Investigation of AZGP1 as a marker and driver of prostate epithelial differentiation
Keywords:  Department of Biology
biology
cancer
prostate cancer
cancer biology
AZGP1
differentiation
Thesis

Prostate cancers exhibit a range of clinical behaviors, from indolent to highly aggressive, reflecting differences in underlying biology. Tailored treatments are needed to match those differences. Our lab previously identified a subset of prostate cancers marked by expression of Alpha-2-Glycoprotein 1, Zinc-Binding, (AZGP1) that is associated with more favorable patient outcomes. AZGP1 is also expressed in mature prostatic secretory epithelium, and we have speculated that it marks a particular state of prostatic epithelial differentiation where the corresponding cancerous cells are clinically less aggressive. Here, we have investigated the connection between AZGP1and prostatic epithelial differentiation using a three dimensional (3D) cell culture model system. We show that prostatic epithelial cells grown in a basement membrane rich extract form spheroid cell aggregates that exhibit morphologic differentiation, and that AZGP1 expression is induced in a subset of cells coincident with morphologic differentiation. To investigate a functional link between AZGP1 and prostatic epithelial differentiation, we used CRISPR/Cas9 genome editing to knock out AZGP1 in prostatic epithelial cells. Notably, AZGP1 knockout disrupts normal morphologic differentiation, producing spheroids with increased pyknotic and fragmented nuclei. By transcriptome profiling, the AZGP1 knockout spheroids also exhibit lost induction of genes associated with epithelial differentiation, and lost repression of genes of the mitotic cell cycle. Finally, the genes regulated by AZGP1 in 3D culture show enrichment among the genes co-expressed with AZGP1 in normal prostate tissue, validating our 3D model system. Taken together, our findings reveal that AZGP1 not only marks prostatic epithelial differentiation, but likely functions as a master regulator of cell fate, inducing a molecular differentiation program while repressing cell division. Agents that induce or mimic AZGP1 activity may provide novel therapies for prostate cancer.
Investigation of therapeutic effects of a novel adrenergic ligand in mouse models of Alzheimer’s disease
Keywords:  Department of Biology
Alzheimer’s disease
noradrenaline
beta1-adrenergic receptor
biology
Thesis

A well-established sign of early-stage Alzheimer’s disease (AD) is degeneration of the noradrenergic network, the circuit of neurons charged with producing and distributing the neurotransmitter noradrenaline (NA) throughout the brain. Thus, a substantial decrease in NA signaling is believed to underlie AD-related cognitive deficits and pathological changes within the brain. Studies have demonstrated that reduction or inhibition of NA signaling exacerbates cognitive symptoms of AD in mice and humans, and reduction of NA signaling has also been shown to increase AD-related neuropathological changes in animal models. Collectively, such findings suggest that activation of the adrenergic system could alleviate AD progression. Previous mouse studies on the therapeutic potential of beta-adrenergic system activation have utilized compounds that are largely ineffective at crossing the blood-brain barrier (BBB) to exert an effect within central nervous system (CNS). The current study investigates the capacity of a novel small molecule modulator, initially believed to be a selective beta1-adrenergic receptor (ADRB1) partial agonist with high BBB permeability, to alleviate neuropathological changes in Thy1-hAPPLond/Swe+ (APP) and 5XFAD mouse models of AD. Tissue from two chronic dosing studies performed in these transgenic lines with the compound SHSU01010 was processed for evidence of three key neuropathological AD hallmarks – amyloid beta plaque accumulation, neuroinflammation, and synaptic loss. Data from immunohistochemistry, quantitative RT-PCR, and ELISA show that chronic SHSU01010 administration was ineffective at alleviating the AD neuropathology for which a phenotype was observed in APP and 5XFAD mice. We believe the lack of therapeutic efficacy exhibited by SHSU01010 may be attributed to its existence as two stereoisomers, where one may agonize beta-adrenergic signaling while the other antagonizes the system. Additionally, further characterization of SHSU01010 has demonstrated that the compound shows in vivo instability due to degradation of the compound by liver enzymes, and that the compound may not be selective for ADRB1. While the findings from the current study are inconclusive, we believe ADRB1 agonism with CNS-permeable compounds still shows substantial promise for AD treatment.
Investing in socialist Poland : a transnational history of finance in the Cold War, 1944-1991
Keywords: History.

This dissertation explores socialist Poland's ties to international financial institutions during the Cold War era. Revealing the extent to which individuals and institutions cooperated across the Iron Curtain, it challenges the idea of a bipolar world order as an all-encompassing description of international relations in the second half of the twentieth century. Studying socialist Poland solely within the framework of Soviet politics and the bipolarity of the Cold War omits a crucial part of its international history; the country's development followed worldwide patterns of globalization, not just the rhythm of superpower politics. This dissertation argues that the end of communist rule in Eastern Europe cannot be understood without considering the region's integration into global financial markets.
Invisible cages : algorithmic evaluations in online labor markets
Keywords: Management Science and Engineering.

Artificial Intelligence systems, powered by algorithms, are seemingly everywhere: in corporations, hospitals, classrooms, cars, and even baby monitors. Despite the prevalence and breathless rhetoric, fewer studies have examined how these systems impact people in practice. This dissertation focuses on understanding the impact of algorithms on people using online labor markets to find work. Existing organizational and social science theory suggests that artificial intelligence and algorithmic systems are "tightening" the iron cage by providing a more sophisticated, rational method of controlling the way people work and interact. This dissertation, however, reveals how an online labor market's use of algorithms is creating modern day invisible cages, in which platforms deliberately hide the norms and expectations for how people should behave. To unpack and theorize this central finding, I draw upon field work collected from one of the world's largest online labor markets. Using participant observation, interviews, and extensive archival data, I first show how people using the online labor market unwittingly gave the platform full permission to implement algorithms that were completely opaque to them. I highlight how the way in which people agree to the terms of service in an online labor market context represents a significant shift compared to previous agreements people consented to in similar, offline labor market settings. I then show how the online labor market implemented an inscrutable algorithm dictating people's success on the platform. The implementation of this algorithm led to what I call "superstitious reactivity, " because people were never able to verify if and how their actions contributed to their success on the online labor market. Taken together, this dissertation has implications for our understanding and the literature on algorithms, evaluations, reactivity, reputation, labor market intermediaries, employment relationships, digital contracts, and agnotology.
Ion penetration in conjugated polymers : connecting structural effects and electronic transport
Keywords: Materials Science and Engineering.

Ionic liquids are increasingly employed as dielectrics to generate high charge densities and enable low-voltage operation with organic semiconductors. However, effects on structure and morphology of the active material are not fully known, particularly for permeable semiconductors such as conjugated polymers, in which ions from the ionic liquid can enter and electrochemically dope the semicrystalline film. To understand when ions enter, where they go, and how they affect the film, thin films of the archetypal semiconducting polymer, poly(3-hexylthiophene) (P3HT), are electrochemically doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]), the archetypal ionic liquid. High-resolution, ex situ x-ray diffraction measurements and complete pole figures reveal changes with applied voltage, cycling, and frequency in lattice spacing, crystallite orientation, and crystallinity in the bulk and at the buried interface. Dopant ions penetrate the film and enter the crystallites at sufficiently high voltages and low frequencies. Upon infiltrating crystallites, ions permanently expand lamellar stacking and contract pi-stacking. Cycling amplifies these effects, but higher frequencies mitigate the expansion of bulk crystallites as ions are hindered from entering crystallites. Important metrics for electronic transport such as mobility and drain current ON/OFF ratio are also affected following patterns analogous to those seen for lattice spacing and crystallinity under two operating regimes. This mechanistic understanding of the structural effects of ion penetration will help develop models of the frequency and voltage impedance response of electrochemically doped conjugated polymers and advanced electronic applications.
It Motivated Me More Than It Crushed Me: Children of Incarcerated Parents in a Highly Selective University
Keywords: parental incarceration
education
higher education
Stanford Graduate School of Education
Comparative Studies in Race and Ethnicty
Thesis

With over 2.7 million American children living with a parent absent to jail or prison, the rampancy of parental incarceration has become an insidious epidemic that disproportionately affects impoverished Black and Hispanic youth. While minimal research has examined these children at the elementary and secondary education levels, there has been no research to date about their experiences in institutions of higher education. In order to address this void and explore how educational systems can better adapt to the circumstances of parental incarceration to facilitate student achievement, this study employed a semi-structured, qualitative research design to examine the perceptions of twelve students with histories of parental incarceration at a highly selective university. Results suggest that the majority of the participants 1. perceived their parents’ incarceration as the impetus for their educational performance; 2. demonstrated an independence that has led to social isolation within educational environments; and 3. used their experiences with parental incarceration and its symptomatic adversities to inform their social impact career aspirations. This study suggests that these students’ narratives and their successes should not be used as models for other children of the incarcerated to strive for. Rather, the analysis reveals what exactly was burdened by these participants in order for them to attain academic excellence and how those burdens can be structurally displaced onto educational institutions. Finally, to begin to rectify the intergenerational effects of parental incarceration, this study suggests that there must be a commitment to addressing the historical sentiment, pervasive in the bedrock of American democracy, that deems poor families of color unworthy of remaining a family unit.
It Was Just Me and the Book: Understanding How Students Navigate the NYC School Choice Process
Keywords: Graduate School of Education
school choice
New York City education
educational inequality
low income school
student choice
eighth grade
high school
public school
guidance counselor
high school
specialized high school
Thesis

Although the New York City Public School system is a free choice system on paper, in reality access is limited by the complexity of the school choice process. The resulting inequality is disproportionately borne by low income students of color in New York City neighborhoods who face the sometimes tacit school choice procedures. This research aims to understand the range of experiences of low income Black and Latinx students in New York City in understanding and navigating the public school admissions system. In semi-structured interviews, I questioned seven students about their educational experience of selecting a high school in New York City and how those experiences were shaped by the levels of information or resources that were available to them. I focused on what kind of support the students received in their respective middle schools. Overall I found that students themselves develop a critique of systemic inequities and cultivate strategies for responding to these disparities. Additionally, the term “school choice” is deceptive since many students are unable to exercise choice. Thus, while schools are often popularly imagined as spaces of opportunity for upward socioeconomic mobility, they are in fact deeply reproductive contexts characterized by systematic disparity and exclusion.
Jessica Alva was a MMIW advocate. Now she’s their latest rallying cry
Keywords:  Department of Communication
Brenner, R.B.
Stanford Journalism
Missing and Murdered Indigenous Women
MMIW
Thesis

Jessica Alva, 35 and mother of six, died on April 6, 2019. Her death has been ruled as a suicide by the San Francisco Office of the Medical Examiner, but her family believes she was a victim of domestic violence resulting in death. Her death is being investigated by the Special Victims Unit of the San Francisco Police Department. Alva is an Indigenous descendent of the Blackfeet and Chickasaw Tribes of the United States, as well as the Aztec and Yaqui Tribes of Mexico. If her family's suspicions are true, her story would be one example of a myriad of cases affections Native American communities known as the Missing and Murdered Indigenous Women (MMIW) movement, where data shows that Native women are being murdered and going missing at disproportionate rates.
Justice and work-family conflict
Keywords: Philosophy.

In recent years, scholars and activists have sought to make workplaces friendlier for employees with family responsibilities. Are such workplace changes requirements of justice, and if so, why? I argue that we should make these changes because lifestyles that mix work and family are valuable, and such lifestyles are harder to come by than they would have been if not for our history of gender injustice. The latter point, I claim, licenses an exception to the general liberal ban on promoting particular lifestyles. This exception is needed to make good on the promise of equal citizenship for women. My argument contrasts with the more familiar one that justifies family-friendly workplace policies because they further the equal representation of women in employment. The familiar argument falls short in two ways. First, there evidence that family-friendly workplace policies sometimes exacerbate the gendered division of labor (because women use them more than men). Secondly, achieving gender proportionality across social roles does not require changing those roles. If there is, in fact, a justice-based rationale for improving the fit between work and family life, we need one that appeals directly to the value of a mixed life and does not piggyback on the also worthy goal of ending the gendered division of labor. That is what I provide in this dissertation.
Keen to Screen: The European Union Response to Growing Chinese Investment
Keywords: Center for International Security and Cooperation
European Union
China
FDI
investment screening
Chinese investment
Thesis

In March 2019, the European Union adopted a framework for screening foreign direct investments entering the EU. However, the framework fails to grant the European Commission the power to block investments that threaten security or public order, rendering the legislation essentially toothless. Why did the EU decide to pass a toothless regulation on investment screening? This thesis seeks to understand the EU’s motivations for adopting an impotent screening regulation. Using evidence from periodicals, public statements, and interviews with European bureaucrats, this thesis argues that the unparalleled risks associated with Chinese FDI compelled some Member States to push for screening at a European level. With an increasing amount of Chinese investment, particularly in strategic sectors like critical technology and infrastructure, countries like Germany began to comprehend the economic and security threats posed by Chinese FDI. Meanwhile, other states that benefitted from Chinese investment sought to keep Chinese capital flowing and therefore opposed investment screening. Some states also disapproved of screening because they thought this measure was protectionist and antithetical to the EU principle of open markets. To balance these differing stances on Chinese investment, the EU created an empty legislation that would meet the least amount of resistance in a vote. Furthermore, as a volatile turn in transatlantic relations took hold, the EU sought to assert its autonomy from both the rising power of China and its traditional ally the United States. The passage of the screening framework, despite its weaknesses, served as a signal of independence to the international community.
Knowledge inequality
Keywords: Sociology.

Never before has such a wealth of information been so immediately accessible to so many and yet the filtering demands so high. Information truly is power; who possesses it and wields it most effectively has profound consequences for inequality and human welfare. Are some groups systematically advantaged across all areas of factual knowledge? Or is there a knowledge division of labor, in which some groups specialize in certain areas? Rather surprisingly, we have no systematic accounting of who knows what. My dissertation provides a comprehensive description of knowledge in the United States. To accomplish this, I compiled data on 513 factual knowledge questions from 48 nationally representative surveys fielded between the years 2005 and 2015. The first paper, presented in Chapter 2, explores overall trends in the general knowledge of United States adults in 16 different domains. People know the most about current events and the least about economics. Chapter 3 explores demographic patterns in differential knowledge attainment, providing concrete evidence on the size of knowledge disparities by gender. Social expectations and socialization shape the knowledge acquired by men and women, with dramatic consequences for inequality. Finally, my third paper presents my method BINCONT (the Binned INcome CONtinuous Treatment), which allows researchers to impute estimates of missing binned income data that approximate a continuous distribution. My dissertation analyzes the social ecosystem of knowledge. I investigate many domains of factual knowledge from religion to language to science to war. I evaluate men's and women's command over factual knowledge in a wide variety of domains. I describe the present state of factual knowledge, and I present gendered patterns of inequalities. Overall, the project contributes to the field of knowledge inequality.
The Koroghlu epic in trans-imperial perspective : the story of the Ottoman and Safavid expansion and crises
Keywords: History.

This dissertation examines the epic of Koroghlu ("the blind man's son"), an oral tradition that spread through Eurasian lands during the early modern period. The epic contains a strong critique of imperial power and reflects the rapid imperial expansion of the previous century and the partitioning of Anatolia and Iran between the Ottomans and Safavids. The story also reflects the political, military, and social crises which followed this expansion, and which followed broader global patterns of empires during this era. By first describing the oral and performative manner in which the Koroghlu tradition circulated, along with other epics, and then analyzing the story according to the themes of space, time, and power, this dissertation shows how entangled the lands of Anatolia and Iran were during the early modern period. It also discusses the historical relevance of several important narrative themes in the epic in the 17th century context, including banditry, tribal politics, Turkoman identity, perceptions of Ottoman power, and the geographic notion of Anatolia (or "Rum") and Iran.
Label-free optical detection of bioelectric potentials using electrochromic thin films
Keywords: Chemistry.

Recording electrical signals from cells with electrode arrays is limited by the number of addressable cells, fixed recording sites, and incompatibility with optical tools. Herein, we overcome these limitations by recording field potentials using electrochromism to translate electrical signals into changes in optical absorbance. We use a prism-coupled attenuated total internal reflection laser setup to interrogate the small changes in color by examining the light intensity of a laser beam reflected by the film. We apply this label-free technique to genetically modified cells, human iPSC-derived cardiomyocytes, primary mouse hippocampal neurons, dorsal root ganglion neurons and organotypic hippocampal brain slices. This platform is a powerful method to study electrically active cells which are difficult to transfect since the field of vision can be redirected by stirring the laser onto to the desired region of interest.