VictorJuiz/thesis huggingface dataset:
High-precision acoustic and inertial sensors in interferometric silicon micro-structures
Keywords: Electrical Engineering.

In recent years, fiber-based optical sensors utilizing a flexible diaphragm microstructure as a mechanical transducer have surpassed conventional electronic MEMS sensors as compact, high-resolution force sensors. They have been implemented as acoustic sensors and accelerometers capable of resolving µPa/√Hz and µg/√Hz over tens of kHz of bandwidth, enabling a wide range of high-performance applications such as long-range inertial navigation, underwater communications, and cellular studies. In particular, state-of-the-art optical MEMS acoustic and acceleration sensors, typically based on Fabry-Perot or phase-front modulation (PFM) interferometers, exhibit a particularly high sensitivity. However, these sensors are difficult to align during assembly, and they have a strong wavelength dependence, which makes it challenging to multiplex them into arrays. They also require active feedback of the wavelength of the laser used to probe them in order to maintain a stable, high sensitivity. This thesis presents the theoretical modeling and experimental characterization of two new generations of PFM sensors that address these issues by self-aligning a fiber with a diaphragm suspended on micrometric springs to form a stable two-wave interferometer. Fabricated on silicon-on-insulator wafers using standard clean-room tools, these sensors are compact and quick to assemble reproducibly, and they exhibit a weak wavelength dependence and no polarization dependence. The first generation of hydrophone has a flat sensitivity extending from 100 Hz to 2 kHz and an average minimum detectable pressure over this region of 74 µPa/√Hz. With a resolution comparable to the noise of quiet ocean environments, these sensors are good contenders for deep-ocean acoustics and seismic monitoring. The second generation of sensors implements a novel self-aligning scheme and demonstrates a reproducible sensitivity spectrum. They exhibit a record low resolution of 215 nPa/√Hz between 40 Hz and 3 kHz, which represents a 10-fold improvement over the previous record reported in the literature. With an equivalent force resolution of 1.5 pN/√Hz, these new sensors are well-positioned for micro-cellular studies. They are in fact sensitive enough to resolve the extremely weak phase noise imparted to the probe light by the thermal noise of the diaphragm structure. When used as accelerometers in a vacuum, their resolution is as low as 160 ng/√Hz over 3 kHz of bandwidth, which satisfies the most stringent requirements for inertial navigation of aircraft
High-speed D/A conversion in FinFET CMOS technology
Keywords: Electrical Engineering.

Digital-to-analog converters (DACs) are crucial building blocks in modern communication systems like wireline transceivers and digital mm-wave phased arrays. These applications drive steady increases in bandwidth, channel count, as well as integration density, which mandates data converters that are compatible with the latest CMOS technology. For analog-to-digital converters (ADCs), this has led to an architectural shift toward time-interleaved successive approximation, which exploits the strengths of modern CMOS while mitigating its weaknesses. On the other hand, DACs have not significantly changed since the 1970s and predominantly rely on the current steering (CS) topology. We discuss an alternative approach for high-speed (> 10 GS/s), moderate-resolution (6-8 bit) DACs, with the specific goals of reducing chip area and improving FinFET CMOS compatibility. Our DAC uses a switched capacitor (SC) architecture that separates the functions of level generation, timing/combining, and output power delivery, which are lumped into a single node in a conventional CS DAC. In the proposed DAC, levels are generated using time-interleaved SC DAC cores with sub-femtofarad unit capacitors, which offer sufficient linearity and noise performance at the 8-bit target resolution. The cores' outputs are combined and re-timed downstream and the final 50 Ohm load is driven by an inverter-based buffer. To validate this new approach, we implemented a series of 8-bit prototype DACs in 16 nm FinFET CMOS, operating at 14 GS/s, 28 GS/s (2x time-interleaved) and 56 GS/s (4x delta-interleaved), respectively. These designs show competitive performance while achieving up to 10x area advantage over the state of the art
The historical origins of Republican economic ideology : a computational text analysis approach
Keywords: Economics.

This dissertation seeks to understand the historical origins of modern Republican economic ideology. I contribute to this topic by using computational text analysis methods to quantitatively characterize ideological language from the past and track its persistence into modern political speech. The first chapter tracks the persistence of segregationist language from the mid-20th Century in economic speeches today. The second paper focuses on the persistence of conservative and liberal language from the New Deal era. Finally, the third paper focuses on the specific issue of immigration and compares attitudes of politicians in the past vs. the present. I contribute to the economic history literature by more comprehensively quantitatively linking language from the past and present using innovative natural language processing methods and interpreting these findings within the broader historical context
Holographic Quantum Error Correction from half-line-AdS/BCFT
Keywords:  Department of Physics
quantum error correction
AdS/CFT
Text
Thesis

The AdS/BCFT correspondence is a novel setting in which to study the holographic principle, which has not yet been studied as thoroughly as the regular AdS/CFT correspondence. In particular, it replaces the familiar CFT with one defined on a manifold with a boundary. In this report, we show analogous results on the boundary-bulk operator correspondence as in AdS/CFT, as well as present a tensor network model for the new formulation. In this process, we extend the HKLL construction to AdS/BCFT under particular constraints - namely, states obtained from $\Z_2$ symmetry. We also provide a simulation of the percentage of qubits necessary for recovery of information on the bulk. We then point to future studies implementing this model.
How Americans think about democracy
Keywords: Political Science.

This dissertation examines how Americans think about democracy, and how presidents can shift what they deem allowable in a democracy. The first paper explores how people talk about democracy and finds that respondents mention rights and freedoms the most in their open-ended responses. Additionally, there are divisions in how people think about democracy along a variety of demographic lines, most notably by partyID: Democrats mention voting and equality more, and Republicans mention the Constitution and what should be fixed in the country. The second paper examines heterogeneity in beliefs around democracy by asking respondents about six precise democratic principles. Respondents support the democratic idea on four of the six statements similarly. However, many respondents in both parties support media censorship and allowing politicians to call their opponents disloyal. The third paper leverages two survey experiments to show that voters allow presidents of their own party to push democratic norms more than a president of the opposing party. Combined, both of these experiments show that voters are 'following the (party) leader' and underscore that many voters place partisanship above democratic health
How does better access to public firm disclosures affect IPO firm financing?
Keywords: Business.

I study how improved access to public firm disclosures affects private firm financing through IPOs. Theory indicates that although improved access to public firm disclosures can reduce IPO investors' valuation uncertainty, it can also lead to increased adverse selection. This tension leaves the net effect of public disclosure improvements on IPO pricing uncertain. I exploit the introduction of EDGAR to examine this question empirically. The results show IPO firm underpricing decreases systematically as more public peer firms adopt EDGAR. This finding is stronger when IPO investors face more valuation uncertainty, when peer firms' information quality is high, when alternative information sources are scarce, and when peer disclosures contain more industry-wide information. Increased equity research coverage of public peers also contributes to this finding. Together, the results suggest better dissemination of public firm disclosures can reduce frictions for private firms seeking to procure equity capital
How Eurosceptic Party Rhetoric is Changing in the Post-Brexit Era
Keywords: Euroscepticism
European Politics
Brexit
Manifestos
Text
Thesis

Euroscepticism has been on the rise in Europe for the past two decades and saw its first major political win in the United Kingdom’s decision to leave the European Union in 2016. Scholars feared this “Brexit” referendum would spark a wave of Euroscepticism to wash over the continent and prompt more “leave” referendums, but the drawn out negotiations over a withdrawal deal have dampened much of the European public’s Eurosceptic fervor. How have Eurosceptic parties reacted in the post-Brexit era? In this thesis, I use a combination of Eurosceptic party manifesto data, Eurobarometer survey data, and case studies of specific Eurosceptic parties to assess to what extent the rhetoric of Eurosceptic parties changed in reaction to Brexit, and explore the factors driving these changes. My analysis suggests that hard Eurosceptic rhetoric, which is rhetoric advocating for a member state to leave the EU, dropped slightly in the aftermath of Brexit. This thesis contributes to the literature on Eurosceptic thought, European Union cohesion and empirical studies that use rhetoric as a measure to gauge political party intentions.
Human natural killer cell development in the age of single cell technologies
Keywords: Microbiology and Immunology.

The study of hematopoiesis has been an ongoing effort to understand how the immune system develops. Throughout the course of history, the use of flow cytometry has enabled us to understand the development of multiple immune cell lineages. However, human Natural Killer (NK) cell development remains an elusive developmental population requiring further study to identify. NK cells have been characterized as cytotoxic innate lymphocytes that produce cytokines and clear viral infected and cancerous cells. Unlike other immune cell lineages, a comprehensive developmental pathway has yet to be identified. While developmental populations have been identified in human bone marrow (BM), these cells are rare and a larger pool of progenitors must exist due to their short lived nature. The use of single cell technologies presents an innovative approach to dissect the BM compartment and find novel precursors that will elucidate the development of NK cells. Utilizing these technologies allowed for the identification of a group of cells identified using transcriptional regulators key to NK cell development, ETS1 and ID2. Ultimately, our study expands our knowledge of new stages of NK lineage commitment for use in cancer immunotherapies
Human Trafficking as a Crime Against Humanity: Puerto Rico’s Innovative Approach to Human Rights Legislation
Keywords: Puerto Rico
Crimes against humanity
Transitional justice
Text
Article
Thesis

Julian Bava focused his human rights capstone on analyzing the history and text of Puerto Rico’s Crimes Against Humanity (CAH) legislation in order to determine its potential effectiveness as an accountability tool. Utilizing Article 300 of Title V (“Crimes Against Humanity”) of the Penal Code of Puerto Rico (the “Penal Code”), Julian notes how Puerto Rico is unique in offering a state level framework for prosecuting atrocity crimes and reveals the critical role subnational jurisdictions may play in shaping international law and its application within the United States. With this analysis, Julian shows how Puerto Rico’s atrocity crimes legislation provides a promising landscape that not only pushes international law in a novel direction, but also provides tangible opportunities for victims to seek redress.
Student project deposited by department for archival purposes. Original work unavailable for public download due to permission restriction preferences of the author.
Hurdles to targeting the CD47-SIRP-alpha interaction for immunotherapy
Keywords: Immunology.

The CD47-SIRPα signaling pathway has emerged as an important innate immune checkpoint axis, with CD47 acting as a marker of self and health. Numerous cancers have been shown to upregulate CD47 expression, including hematologic cancers such as acute myeloid leukemia (AML) and non-Hodgkin's lymphoma (NHL), and myeloma, and solid tumors such as ovarian cancer, breast cancer, head and neck cancers, colon cancer, pancreatic neuroendocrine tumors, small lung cell cancer, and glioblastoma. The number of pharmaceutical companies and startups developing therapies which target this immune axis has grown exponentially in the past decade. At the forefront are antibodies which bind CD47 and interrupts its binding to SIRPα. The biggest challenges to targeting CD47 are the on-target effects on red blood cells and platelets, both of which depend on cell surface CD47 to avoid phagocytosis. Patients receiving treatments suffer from anemia and thrombocytopenia. Additionally, it remains unclear if other types of healthy cells rely solely on CD47 as a "don't eat me" signal and are subject to depletion like RBCs and platelets. Another hurdle is one that plagues all therapies -- heterogeneity in response within the human population. Further understanding of the CD47-SIRPα pathway is necessary to identify the patients that can benefit the most from treatment. The goal of this thesis is to explore some of these hurdles to inform future decisions that can impact patient health. This thesis will show that marginal zone B cells is another population of cells of the hematopoietic lineage that are depleted during CD47 blockade. It further shows that polymorphisms in SIRPΑ might partially explain some of the heterogeneity seen in response to CD47 immunotherapy and might also regulate platelet numbers and size, with implications for thrombocytopenia, stroke and coronary disease. These findings should initiate new avenues of research which will ultimately give a better understanding of the impact of on-target treatment-related adverse events and genetic variations on therapies targeting the CD47-SIRPα axis
"I Didn't Want to Trigger Them": Latinx Student Perceptions of Teacher Political Ideology in the Trump Era
Keywords: Education
Learning
Latin Americans
Students
Teachers
High schools
Politics and government
Text
Thesis

The “Trump Era” has impacted nearly every aspect of American society, including education. With many ethnically and racially minoritized populations, including Latinos, being the targets of harmful and discriminatory rhetoric that has become associated with the Republican Party, this paper examines how the perceptions that students have of their teacher’s political ideology affects their educational experiences. I interviewed seven Latinx-identifying high school students from three different states, two of which are considered “blue states” and the other a “red state” to answer the following question: in what ways does Latinx student awareness of teacher political ideology affect their educational experiences? I asked students multiple questions about how they were able to form an idea of what party their teachers identified with politically, how that made them feel, how it impacted their interactions with the teacher, and how they felt about political disclosure in the classroom. There were three main findings as a result of this study. The first is that political disclosure on behalf of teachers is not the only way in which students develop an understanding of what their teacher’s political ideology is; students use their own lived experiences and outside knowledge to draw conclusions about their teacher’s political leanings, therefore both students and teachers bring politics into the classroom. The second finding is that Latinx student experiences are greatly impacted by their perception of their teacher’s political ideology, but especially so for students who perceive their teachers as conservative. The third finding is that while student experiences are impacted, they are able to rationalize their experiences and acknowledge that their teachers are entitled to their own opinions. This study has implications for the future of teaching, including the call for incorporating culturally responsive training and teaching.
Identification of a Myogenic and Highly Transplantable Tert Expressing Non-Satellite Stem Cell Population
Keywords:  Department of Biology
Biology
Skeletal Muscle
Stem Cells
Telomerase
Regenerative Medicine
Text
Thesis

Telomerase Reverse Transcriptase (Tert), a component of the telomerase holoenzyme complex, has been previously identified as a marker of stem cell populations across tissues. However, its role in skeletal muscle is poorly understood. In skeletal muscle, volumetric muscle loss injuries pose a unique challenge for cellular-based therapies, which so far have been relatively unsuccessful in preclinical models. Using a Tert-lineage tracing genetic mouse model, we identified a set of rare Tert expressing cells distributed throughout muscle. These Tert-lineage cells expand upon injury and contribute to myofiber regeneration in a delayed fashion. In addition, muscular regeneration upon repeated injuries is impaired by the loss of Tert in Tert expressing cells and their progeny. While a very small population of satellite cells express Tert, we also identified a population of Tert Expressing Multipotent Myogenic Progenitors (TEMMPros). These TEMMPros are multipotent and myogenic in vitro and via transplantation in a Tert-dependent manner. Furthermore, transplantation of these TEMMPros resulted in improved regeneration compared to satellite cells in a mouse model of volumetric muscle loss. Single-cell sequencing reveals that TEMMPros are transcriptionally distinct from other known skeletal muscle cell populations including satellite cells. These observations identify a novel subset of myogenic, non-satellite Tert expressing cells in mice that possess remarkable capacity for regeneration and may serve as a cell-based therapeutic for skeletal muscle damage.
Identifying the mechanism of aged oligodendrocyte progenitor cell rejuvenation by young cerebrospinal fluid
Keywords:  Department of Biology
Biology
Aging
Myelin
Actin
Activity-Dependent
SRF
CSF
Text
Thesis

As humans age and develop aging-related diseases, many learning and memory functions can be compromised as the myelin sheath surrounding axons is lost. Previous work has demonstrated that these cognitive functions, which are mainly coordinated in the hippocampus, require the activity-dependent myelination of axons by oligodendrocytes. Given the literature demonstrating myelin degeneration with aging and neurodegenerative disease, we hypothesized that loss of white matter could drive aging-related cognitive decline and that protecting myelin could prevent this decline. This project aims to characterize the effects of exposing aged mice to young mouse cerebrospinal fluid (CSF) and identify the mechanism of oligodendrocyte rejuvenation. The paradigm for this project involved extracting CSF from young mice and transfusing it to aged mice through carefully regulated mini-osmotic pumps. These mice were then used for behavioral studies, immunohistochemistry staining, and sequencing experiments. The results showed increased proliferation and differentiation of aged oligodendrocyte progenitor cells (OPCs) when exposed to young CSF. Further characterization of transcriptomic changes revealed the upregulation of a few transcriptional factors including serum response factor (SRF) which is known to play an important regulatory role in the contraction of muscle cells. Increased expression of these transcription factors and their downstream targets suggest an actin-mediating mechanism for the rejuvenating effects of young CSF. These findings suggest therapeutics targeting SRF and actin pathways in OPCs could rescue myelination and improve cognitive function in aged mice. Developing therapeutics with these abilities could allow for clinical improvements in learning and memory for the growing elderly population, especially those suffering from aging-related memory disorders.
Identifying the sources and drivers of variable nitrous oxide concentrations across the Eastern Tropical North Pacific
Keywords: Nitrogen cycle
Greenhouse gases
Anoxic environments
Stable isotopes
Climate and interannual variability
Chemical oceanography
Oceanography > Research
Biogeochemistry
Text
Thesis

Nitrous oxide (N2O) is a powerful greenhouse gas, and oceanic sources account for up to one third of total flux to the atmosphere. In oxygen-deficient zones (ODZs) like the Eastern Tropical North Pacific (ETNP), N2O can be produced and consumed by several biological processes. In this study, the concentration and isotopocule ratios of N2O from a 2016 cruise to the ETNP were analyzed to examine the sources of and controls on N2O cycling across the region. Along the ~1000 km north-south transect, three distinct biogeochemical regimes were identified: background, core-ODZ, and high-N2O stations. Background stations were characterized by smaller variations in N2O concentration and isotopic profiles relative to the other regimes. Core-ODZ stations were characterized by co-occurring N2O production and consumption at anoxic depths, indicated by high δ18O-N2O (> 90‰) and low δ15N2Oβ (< -10‰) values, and confirmed by a time-dependent model, which indicated that N2O production via denitrification was significant and may occur with a non-zero site preference. High-N2O stations, located at the periphery of a mesoscale eddy, were defined by [N2O] reaching 126.07±12.6 nM and low oxygen concentrations expanding into near-surface isopycnals. At these stations, model results indicated significant N2O production from ammonia-oxidizing archaea and denitrification from nitrate at the N2O maximum within the oxycline, while bacterial nitrification and denitrification from nitrite were insignificant. This study also represents the first in the ETNP to link the magnitudes of N2O production mechanisms to a mesoscale eddy through isotopocule measurements, suggesting the importance of eddies to the spatiotemporal variability in N2O cycling and emissions from this region.