VictorJuiz/thesis huggingface dataset:
Noncommutative Distributional Symmetries and Their Related de Finetti Type Theorems

The main theme of this thesis is to develop de Finetti type theorems in noncommutative probability. In noncommutative area, there are independence relations other than classi- cal independence, e.g. Voiculescu’s free independence, Boolean independence and Muraki’s monotone independence. Free analogues of de Finetti type theorems were discovered by Ko ̈stler and Speicher and were developed by Banica, Curran and Speicher. Here, we will define noncommutative distributional symmetries for Boolean and monotone independence and we will prove de Finetti type theorems for them. These distributional symmetries are defined via coactions of quantum structures including Woronowicz C∗-algebra and So ltan’s quantum families of maps. We show that the joint distribution of an infinite sequence of noncommutative random variables satisfies boolean exchangeability is equivalent to the fact that the sequence of the random variables is identically distributed and boolean independent with respect to the conditional expectation onto its tail algebra. Then, we define noncom- mutative versions of spreadability and show Ryll-Nardzewski type theorems for monotone independence and boolean independence. We will show that, roughly speaking, an infinite bilateral sequence of random variables is monotonically(boolean) spreadable if and only if the variables are identically distributed and monotone(boolean) with respect to the conditional expectation onto its tail algebra. In the end of this thesis, we will prove general de Finetti theorems for classical, free and boolean independence. Our general de Finetti theorems work for non-easy quantum groups, which generalizes a recent work of Banica, Curran and Spe- icher. For infinite sequences, we determine maximal distributional symmetries which means the corresponding de Finetti theorem fails if the sequence satisfies more symmetries other than the maximal one.

Advisor: Voiculescu, Dan Virgil
Molecular Insights into the Structure and Function of the Telomerase Holoenzyme in Tetrahymena thermophila

Telomeres are specialized, G-rich simple-sequence repeats that cap the ends of linear chromosomes to prevent genome instability. These tandem DNA repeats are bound by sequence-specific proteins to create a protective structure that marks the chromosome end thereby preventing aberrant chromosomal recombination, resection, degradation, and fusion. Due to inherent limitations of genome replication and chromosome end processing, telomeres shorten over time leading to potential loss of genetic information if not restored or maintained. The ribonucleoprotein (RNP) telomerase functions in this regard by using an integral RNA template (TER) to synthesize single stranded telomeric repeats at the chromosome end. In vitro minimal catalytic activity can be reconstituted from the telomerase protein component TERT and TER; however, in vivo biologically active holoenzyme requires further protein components for repeat addition synthesis, enzyme recruitment, and regulation in the cell. The ciliate Tetrahymena thermophila serves as an experimentally favorable model system for the study of telomerase due high levels of constitutively active enzyme and robust molecular and genetic techniques. Furthermore, our understanding of the holoenzyme is arguably best characterized from the Tetrahymena enzyme, which consists of nine protein components and the RNA (TERT, TER, p65, p50, Teb1, Teb2, Teb3, p75, p45, and p19). Despite knowledge of the overall architecture, relationships between multiple proteins within the holoenzyme and their specific physiological roles had remained unresolved./nUsing a variety of in vitro and in vivo biochemical techniques, I show that the holoenzyme component p50 functions as a central hub for enzyme assembly, connecting the RNP catalytic core to the RPA-like Teb1-Teb2-Teb3 (TEB) and p75-p45- p19 (CST) subcomplexes. To answer existing questions concerning telomerase recruitment, I employ endogenously tagged holoenzyme proteins to show that all telomerase holoenzyme subunits are subject to coordinate telomere recruitment and release dependent on the cell cycle. Using domain tagging and truncation strategies, I demonstrate that the high-affinity single-stranded telomeric DNA binding component Teb1 is necessary and sufficient for interaction between telomerase and the telomere. This work supports a model for Tetrahymena telomerase-telomere recruitment that breaks the precedent established by studies in yeast and vertebrate cells: Teb1- containing holoenzyme is recruited directly to the telomeric DNA rather than telomerase recruitment by interaction with a telomere-bound protein. Together, along with ongoing studies of the Tetrahymena TEB and CST subcomplexes, these results suggest commonalities of telomerase interaction, action, and regulation at telomeres across species.

Advisor: Collins, Kathleen
When do people rely on algorithms?

Algorithms, scripts for sequences of mathematical calculations or procedural steps, are powerful. Even though algorithms often outperform human judgment, people appear resistant to allowing a numerical formula to make decisions for them (Dawes, 1979). Nevertheless, people are increasingly dependent on algorithms to inform their decisions on a day-to-day basis. In eight experiments, I tested whether aversion to algorithms is as straightforward a story as past work suggests. The results shed light on the important questions of when people rely on algorithmic advice over advice from people and have implications for the use of algorithms within organizations.

Advisor: Moore, Don A
Mobilization and Its Discontents: Identity Politics in the Age of Identity Critique

How can subordinated identity groups organize for political change while avoiding self-descriptions that exclude or marginalize some of their members? How can "queers,” or “women," or "African Americans" mobilize politically without stipulating an idealized vision of their members that excludes or stigmatizes the practices or self-understandings of some who might travel under those very names? This dissertation examines, at a theoretical level, how identity-based groups can make justice claims without specifying what constitutes the identity or submitting to identity’s normative force./nWhereas critics of identity politics, such as Judith Butler, Patricia Hill Collins, and José Esteban Muñoz, examine how identity controls and constrains individual subjects, this project examines identity’s regulatory effects on collective subjects mobilized for political action. The engagement with poststructuralist theory and the focus on mobilization, not just social collectivities, differentiates this dissertation’s concerns from thinkers such as Anthony Appiah, Nancy Fraser, and Iris Marion Young. And while many feminist, queer, and critical race theorists focus exclusively on specific identities, this dissertation analyzes how our understanding of identity itself shapes political membership and mobilization across a wide range of identities and projects./nThis dissertation revisits the extensively explored terrain of normalization and control through identity categories, but focuses specifically on identity constituted in collective political action. It begins by using the movement for marriage equality to illustrate how otherwise emancipatory and egalitarian identity-based political projects can subordinate and stigmatize some of their members in the quest for freedom and equality through idealized visions of membership. Then it explores alternative political formulations of identity that might avoid such injuries. Using feminist and queer theory to extend and transform work by Jürgen Habermas and the later Ludwig Wittgenstein, it refigures an identity-based political group as itself a coalition rather than a homogenous entity. Revisiting the decision in Obergefell v. Hodges, the 2015 Supreme Court decision validating same-sex marriage, it shows how treating identity as a coalition could relieve the social pity, indeed pathologization, of homosexuals living outside of marriage featured in the Majority decision.

Advisor: Brown, Wendy L
Decoupled Vector-Fetch Architecture with a Scalarizing Compiler

As we approach the end of conventional technology scaling, computer architects are forced to incorporate specialized and heterogeneous accelerators into general-purpose processors for greater energy efficiency. Among the prominent accelerators that have recently become more popular are data-parallel processing units, such as classic vector units, SIMD units, and graphics processing units (GPUs). Surveying a wide range of data-parallel architectures and their parallel programming models and compilers reveals an opportunity to construct a new data-parallel machine that is highly performant and efficient, yet a favorable compiler target that maintains the same level of programmability as the others./nIn this thesis, I present the Hwacha decoupled vector-fetch architecture as the basis of a new data-parallel machine. I reason through the design decisions while describing its programming model, microarchitecture, and LLVM-based scalarizing compiler that efficiently maps OpenCL kernels to the architecture. The Hwacha vector unit is implemented in Chisel as an accelerator attached to a RISC-V Rocket control processor within the open-source Rocket Chip SoC generator. Using complete VLSI implementations of Hwacha, including a cache-coherent memory hierarchy in a commercial 28 nm process and simulated LPDDR3 DRAM modules, I quantify the area, performance, and energy consumption of the Hwacha accelerator. These numbers are then validated against an ARM Mali-T628 MP6 GPU, also built in a 28 nm process, using a set of OpenCL microbenchmarks compiled from the same source code with our custom compiler and ARM's stock OpenCL compiler.

Advisor: Asanovic, Krste
Development and Applications of N-terminal Protein Bioconjugation Reactions

With highly evolved structures and function, proteins have an extraordinarily diverse range of capabilities. In order to take advantage of their unparalleled specificity in the field of chemical biology, bioconjugation methods can be used to produce synthetically modified proteins. As applications for protein-based materials are becoming ever-increasingly complex, there is a constant need for methodologies that can covalently modify protein substrates. More specifically, there is a requirement for reliable and chemoselective reactions that result in well-defined bioconjugates that are modified in a single location. We have developed a protein transamination strategy that uses N-methylpyridinium-4-carboxaldehyde benzenesulfonate salt (Rapoport's salt) to oxidize the N-terminal amine to a ketone or aldehyde functionality. We have identified high-yielding conditions for this reaction, such as N-terminal sequence and pH, and shown its applicability in the modification of several protein systems. In addition, we have used N-terminal protein modification methodologies in the synthesis of protein-DNA conjugates, towards the goal of developing a generalizable DNA-directed protein immobilization platform. Overall, the work presented herein expands the toolkit of methodologies available for building protein-based materials.

Advisor: Francis, Matthew B
Time-resolved optical spectroscopy of organic electronics as a function of local environment

Organic semiconductors have the potential to form the basis of the next-generation of electronic devices. Device layers formed from these molecular based materials can be solution processed at room temperature using techniques such as roll-to-roll printing, making them cheaper and more sustainable than inorganic alternatives such as silicon. Furthermore, their properties also enable the development of low-weight and flexible devices to access novel applications. Yet, solution processing also leads to the formation of complex microstructure via self-assembly that strongly impacts the function of such devices. A full understanding of the dependence of device functionality on device structure is needed to direct design of organic semiconductor based devices to drive widespread commercial adoption. The work of this thesis is focused on using time-resolved spectroscopy techniques to study the structure-function relationships of various organic semiconductors as a function of their local environment./nChapters 2-4 focus on using transient absorption microscopy to study structure-function relationships in 6,13-Bis(triisopropylsilylethynyl)pentacene, a model organic semiconductor with applications in organic field-effect transistors and organic solar cells, as a function of the local film microstructure. Chapters 5-6 then turn to a time-resolved fluorescence study of next-generation thermally-activated delayed fluorescence organic light-emitting diodes as a function of the host matrix polarity./nOrganic electronics are a fascinating field of study due to the intertwined relationship between the chaotic self-assembly of the active layers of these devices and their resulting functionality. Molecular design of the building blocks of these films affects the ensemble electronic properties of the entire film not only through the molecular excited states but also by how those molecular electronic states couple together. Efforts to correlate the impact of the local physical structure of samples on the resulting local electronic structure will inform future design decisions in the organic electronics community.

Advisor: Ginsberg, Naomi S
Neutrino Masses in the Landscape and Global-Local Dualities in Eternal Inflation

In this dissertation we study two topics in Theoretical Cosmology: one more formal, the other more phenomenological. We work in the context of eternally inflating cosmologies. These arise in any fundamental theory that contains at least one stable or metastable de Sitter vacuum. Each topic is presented in a different chapter:/nChapter 1 deals with the measure problem in eternal inflation. Global-local duality is the equivalence of seemingly different regulators in eternal inflation. For example, the light- cone time cutoff (a global measure, which regulates time) makes the same predictions as the causal patch (a local measure that cuts off space). We show that global-local duality is far more general. It rests on a redundancy inherent in any global cutoff: at late times, an attractor regime is reached, characterized by the unlimited exponential self-reproduction of a certain fundamental region of spacetime. An equivalent local cutoff can be obtained by restricting to this fundamental region. We derive local duals to several global cutoffs of interest. The New Scale Factor Cutoff is dual to the Short Fat Geodesic, a geodesic of fixed infinitesimal proper width. Vilenkin’s CAH Cutoff is equivalent to the Hubbletube, whose width is proportional to the local Hubble volume. The famous youngness problem of the Proper Time Cutoff can be readily understood by considering its local dual, the Incredible Shrinking Geodesic. The chapter closely follows our paper [1]./nChapter 2 deals with the question of whether neutrino masses could be anthropically explained. The sum of active neutrino masses is well constrained, 58 meV ≤ mν 0.23 eV, but the origin of this scale is not well understood. Here we investigate the possibility that it arises by environmental selection in a large landscape of vacua. Earlier work had noted the detrimental effects of neutrinos on large scale structure. However, using Boltzmann codes to compute the smoothed density contrast on Mpc scales, we find that dark matter halos form abundantly for mν 10eV. This finding rules out an anthropic origin of mν, unless a different catastrophic boundary can be identified. Here we argue that galaxy formation becomes inefficient for mν 10 eV. We show that in this regime, structure forms late and is dominated by cluster scales, as in a top-down scenario. This is catastrophic: baryonic gas will cool too slowly to form stars in an abundance comparable to our universe. With this novel cooling boundary, we find that the anthropic prediction for mν agrees at better than 2σ with current observational bounds. A degenerate hierarchy is mildly preferred. The chapter closely follows our paper [2] .

Advisor: Bousso, Raphael
Essays on Financial Distress

Financial statement analysis has been used to assess a company’s likelihood of financial distress - the probability that it will not be able to repay its debts. In the dissertation at hand, I provide two essays that add to the literature on the application of financial analysis to distressed firms./nThe first chapter is titled “Predicting Extreme Negative Stock Returns: The Trouble Score”. This chapter examines the ability of accounting information to predict large negative stock returns. The Trouble Score addresses an important gap in the literature. Existing distress risk measures focus on predicting the most extreme negative events such as bankruptcy. However, such events are extremely rare and capture only the most financially distressed firms. There are many firms that experience financial distress but do not declare bankruptcy. By analyzing firms that experience a stock price decline of 50 percent or more, the T-Score enables researchers to capture extreme negative outcomes for corporate shareholders beyond commonly used financial distress measures such as bankruptcies and technical defaults./nThe second chapter is titled “Relative Informativeness of Top Executives’ Trades in Financially Distressed Firms Compared to Financially Healthy Firms”. This chapter examines the informativeness of trades by top executives in firms experiencing varying levels of financial distress. Open-market transactions become differentially costly for the top executives of firms in financial distress. If insiders in a financially distressed firm buy the firm’s stock, they expose their financial capital and their human capital to the risks associated with the firm, thus making their trade differentially costly. It is conjectured that if the managers sell, they are subject to higher litigation risk. These differential costs increase the credibility and therefore the informativeness of the signal extracted from top executives’ trades in financially distressed firms. Consistent with this, I find that there is a positive association between top executives’ trades and future fundamental firm performance only in the presence of financial distress. In addition, these trades provide incremental information about the likelihood of survival over the existing distress risk measures. I find that the investors’ reaction to the disclosure of top executives’ purchases increases with the level of financial distress. The reaction is most negative following top executives’ sales in the most financially distressed firms. Finally, I show that there is a delay in the price reaction following top executives’ trades. A trading strategy that takes a long position in financially distressed firms in which insiders are net purchasers, earns future monthly abnormal profits of between 1.43 and 2.08 percent. This finding suggests that top executives’ trades reveal information that can be used to distinguish financially distressed firms that have good future prospects.

Advisor: Zhang, Xiao-Jun
Dechow, Patricia
Professional Midwifery: Learning from the Past and Present to Inform the Future of Maternal Health Services in Guatemala

Guatemala has an unacceptably high maternal mortality ratio (MMR) of 140, and/nimprovements in this area have been slow. Furthermore, gross inequalities in health/noutcomes exist within its population, with over 70% of maternal deaths in Guatemala/noccurring among indigenous Mayan women. Mayan communities have been historically/nmarginalized, and most Mayan women prefer the services of traditional birth attendants/n(TBA). As such, a disconnect exists between the formal and traditional health sectors in/nGuatemala, contributing to poor maternal health outcomes. It is widely agreed that/nprofessional midwifery is an important component of safe motherhood strategies that can/nreduce maternal morbidity and mortality. Today the Guatemalan Ministry of Health is/nreintroducing midwifery for the first time since 1960. Given the potential professional/nmidwifery has to address the obstetric care needs of Mayan women and bridge the gap/nbetween the health sectors in Guatemala, formative research is needed at the outset to/ninform the design and implementation of this program./nThis dissertation aims to inform future directions for professional midwifery in Guatemala/nby assessing and analyzing historical policies and current perspectives and presenting/ncontext-specific recommendations for the future. The first paper looks to the past to/nconsider how international and society-centered forces influenced the creation of policies in/nGuatemala regarding birth attendance since the signing of the Peace Accords in 1996 up to/nthe reintroduction of midwifery. Next, the second paper elucidates the misperceptions,/nattitudes and expectations about the addition of midwifery to the healthcare system by/nGuatemalan physicians, nurses, midwives and TBAs today, identifying potential threats and/nfacilitators to this strategy’s success in Guatemala. Finally, the third paper proposes/nrecommendations for the future, considering identified impediments to midwifery’s capacity/nfor sustainability. This dissertation provides findings that can improve the design,/nimplementation, monitoring and evaluation of the professional midwifery strategy in/nGuatemala, and can inform program and policy decisions to implement this strategy in/nGuatemala, Latin America and beyond.

Advisor: Guendelman, Sylvia
Temperature Coefficient of Secondary Electron Emission: A Novel Thermal Metrology

Mapping temperature with nanoscale spatial resolution is important for thermal transport studies and for device applications. Current state of the art techniques include scanning thermal microscopy, which requires physical contact, and optical thermoreflectance, which has diffraction limited spatial resolution. Scanning electron microscopy (SEM) is routinely used for topographic imaging due to the high spatial resolution and simple sample preparation, but the secondary electron signal has not been used as a temperature sensor./nIn this work, the temperature dependence of SEM signals from a sample’s surface is investigated. The charge flowing through the SEM sample and the emitted secondary electron currents are measured at different temperatures to quantify the temperature dependence of secondary electron emission. I have measured several group III-V and IV semiconductors and have found 100s of ppm/K of thermal response coefficients. I have attempted to utilize the temperature coefficient to map temperature gradients in an SEM image by creating temperature profiles using a microfabricated structure and by implementing a double heater scheme. Technical challenges and practical limitations will require further future work on the effort of mapping temperature and demonstrating higher spatial resolution. This work generalizes the temperature response coefficient of secondary electron emission across various materials and investigates the challenges involved in mapping temperature. SEM thermometry is a novel means of measuring temperature and has the potential for high resolution temperature mapping which can open new research directions such as phonon mean free path spectroscopy.

Advisor: Dames, Chris