VictorJuiz/thesis huggingface dataset:
On the cultural universality of getting “the chills”: Goosetingles and coldshivers as distinct responses to the awesome and the awful

“The chills” refers to a constellation of cold-defense sensations elicited by emotionally significant events. I examined the universality of chills sensations among 2,761 individuals across 26 countries distributed across 6 continents./nAcross these varying cultures, analyses revealed two types of chills with distinct subjective and social correlates: goosebumps and tingling (“goosetingles”) and coldness and shivers (“coldshivers”). Goosetingles accompanied positive emotions, most notably awe, were elicited by reward, and predicted social closeness. Coldshivers accompanied negative emotions, most notably fear and disgust, and was elicited by threat, and predicted social separation. Some elicitors (e.g., success, failure) had stronger effects in cultures where they are more novel. Others, particularly those critical to evolutionary fitness (sexual arousal, danger), had strong effects regardless of culture. Coldshivers predicted separation more strongly in colder climates. These findings document universal approach- and avoidance-specific bodily sensations that reveal the thermoregulatory roots of emotion and social bonds.

Advisor: Keltner, Dacher
Information in, on, and from the Spacetime

Information theory has become increasingly more prominent in physics research, and it is no different in gravity. In this thesis we look at several connections between information and the spacetime./nMotivated in part by the black-hole information paradox, we complete a proof of an asymptotic entropy bound and consider the equivalence principle, both in attempt to answer where information may hide IN asymptotically flat space-times. We consider information bounds IN Riemann flat empy regions and ON the null conformal boundary. Our results led us to investigate the physical principles that render potential information at infinity unobservable and consider a communication protocol illustrating a connection between information and energy. We were able to show that quantum effects can account for unobservability of asymptotic charges./nHolography is the idea that all the information about a spacetime is contained ON a lower dimensional surface (usually the boundary). Its most concrete realization, AdS/CFT, has already revolutionized physics. Still, that has not stopped physicists from seeking suitable generalizations, and it is in this context that holographic screens were introduced. The causal future of a spacetime region, is the subset of the spacetime where information from that region can reach. A certain characterization of the boundary of the future was needed for proving a new area theorem for holographic screens. We provide a proof of this characterization./nEntanglement entropy provides a way of quantifying how information is spread in a quantum system. However, entanglement entropy alone does not provide an exhaustive picture of the distribution of information in a quantum system, and so several other entanglement measures have been studied, including, for instance, entenglement of distillation, entanglement of formation, and entenglament of purification. In many cases, holography provides an efficient way of studying entanglement measures. This allows us to learn about information properties of quantum systems FROM the spacetime. We study potential holographic duals for entanglement of purification and its multipartite generalization, and prove several of their properties.

Advisor: Bousso, Raphael
The Palladion and National Identity

ABSTRACT/nThe Palladion and National Identity/nby/nMorgan Elizabeth Hunter/nDoctor of Philosophy in Classics/nUniversity of California, Berkeley/nProfessor Mark Griffith, Chair/nThis dissertation takes its start from the observation that people of Sixth and Fifth Century Athens, the Hellenistic Troad and Pergamon, and Republican Rome with its Latin Colonies all made use of stories and symbols taken from the Trojan War in the process of creating an acceptable national identity for their states. The Homeric Cycle of epics and their derived tragedies at Athens, the Iliad’s Mount Ida and Temple of Athena Ilias in Pergamon’s Ilion, the legends of Aeneas at Rome all became central to the way people in Athens, the Troad, and Roman Italy came to see their community. These elements of an imagined Trojan past became part of the complex of activities and formal behaviors that being a member of a socio-political community entails, and especially the symbolic associations of these activities to that community, what Abraham Lincoln called the “mystic chords of memory.”/nMy particular focus is on three very odd stories about women that I show lie at the beginning of this process in each case: the story that a tall woman, dressed like Athena and riding in a chariot with Peisistratos, tricked the Athenians into making him tyrant; the story that for a thousand years a small city in Greece annually sent two aristocratic maidens to Troy to be tortured and work as slaves for the rest of their lives; and the story that the Roman Senate ordered two sacred Vestal Virgins to be ritually executed after Hannibal won the battle of Cannae./nI identify a specific sacred component from the heroic past that lay at the heart of all three stories: the Palladion, the cult statue of Athena from ancient Troy itself. I demonstrate, by a close examination of all available evidence from literature, art, and archaeology, that this cult statue was a significant symbolic element in the identity of each community. It provided a tangible, visible link to the Homeric world, and thus was a central component in the creation of three separate national identities./nIn the course of the dissertation, I also compare these ancient processes of identity creation with more modern examples, taken from Elizabethan England, Imperial France, and Stuart Britain. In each case there are remarkable parallels with the ancient cases I have examined, showing that this process of national identity creation is deeply rooted in human social and political behaviors.

Advisor: Griffith, Mark
A Hierarchical Approach to the Design and Optimization of Photonics

Over the last two decades, silicon photonics has rapidly matured, leading to a growing interest in building large complex systems consisting of thousands of integrated optical components. A direct consequence of this push towards large scale integration is the need for high efficiency silicon photonic building blocks./nIn this work, we present a concrete path towards realizing these essential photonic building blocks. The foundation of our approach to designing photonic components is gradient-based shape optimization, which employs boundary smoothing based on high numerical precision polygons. In addition to helping us calculate accurate device sensitivities, this method affords us a great amount of flexibility when representing device geometries and enables us to incorporate design constraints directly into optimizations in a simple and intuitive way./nOur approach to gradient-based optimization shares an important similarity to other forms of shape and topology optimization employed in the nanophotonics community: on its own, it is not a complete solution to designing high performance and robust devices. Due to the inherently non-convex nature of electromagnetic optimization problems, we cannot expect convex optimization to universally yield good devices without outside input. In order to overcome this obstacle, we have systematized the process of providing "outside input" through our hierarchical approach to design and optimization. Using a strategic combination of simple physical analysis to find good starting geometries and optimization with both coarse and fine parameterizations, we show that efficient and robust devices can be designed with minimal guesswork./nUsing this hierarchical approach, we demonstrate how a variety of silicon photonic components can be designed with superior performance. In particular, we design three port splitters, broadband four port splitters, fabrication-insensitive waveguide crossings, and a variety of efficient grating couplers which set a new standard for device performance. These components form the foundation for an optimized silicon photonic component library which will be important for demanding applications of the future.

Advisor: Yablonovitch, Eli
Effects of Downscaling on the Low Swirl Burner

There has been a recent surge of interest in power generation for a variety of small-scale energy applications. However, as devices are scaled down, a variety of problems emerge from both a system and combustion perspective. Addressing the latter, as a machine gets smaller, the effects of heat losses and fluid interaction with walls can quench radical species, effecting the combustion reactions. Furthermore, boundary layer and friction effects which are normally predictable and small (compared to the system output) at high Reynolds numbers can play a large role in the flowfield development as the size of the combustor shrinks and moves from turbulent flow into the laminar and transitional regime./nSeeking to specifically address this gap in available small-scale combustion technology, a potential candidate exists, however, it has only been demonstrated in larger-scale (> 1.5”) applications. This combustion technology, named the low swirl burner (LSB), offers a variety of potential benefits such as ultra low NOx and CO emissions, low pressure drop, and high turndown ratios to suit these downscaled devices. This dissertation first seeks to understand whether the low swirl burner can be adapted to small scale (≈ 3 kW) combustors and, secondly, attempts to shed light on the flowfield evolution as the LSB is downscaled./nAddressing the first aspect, the LSB was successfully scaled down to a 14 mm diameter unit and tested both qualitatively and quantitatively. Results indicated that miniaturized LSBs exhibited all of the operational characteristics of their large-scale counterparts, indicating they are a perfect candidate for future small-scale energy systems./nSecondly, in order to gain an understanding of the flowfield evolution of the miniaturized LSBs, three different diameter LSBs (12, 14, and 25.4 mm) were probed using laser diagnostics over a wide range of bulk inlet velocities and equivalence ratios. Results indicate that while the effects of scaling are evident in certain parameters, the fundamental properties of the LSB are clearly observed. Additionally, the diagnostics employed proved to be ineffective at measuring a key parameter, the turbulent burning velocity indicating that further diagnostics and modeling efforts may be required.

Advisor: Chen, Jyh-Yuan
Mapping the phase diagram of alkyl ligands on nanoparticle surfaces with molecular simulations and field theoretic models

Some of the most important and interesting phenomena in physical chemistry, such as heterogeneous catalysis, semi-conduction, and self-assembly depend crucially upon the surface properties of the material under consideration. This is particularly relevant for nanoscopic objects, whose surface-to-volume ratio is much higher than macroscopic materials. Thus, it is often necessary to carefully engineer nanoparticle surfaces so as to prevent them rom coalescing or reacting with their environment. This is achieved by using passivating ligands that stabilize nanoparticle surfaces and consequently, modify the chemical, optical, and electrical properties of nanocrystals and modulate inter-nanoparticle interactions. As a result, gaining an understanding of ligand behavior is essential to synthesizing new nanomaterials with useful technological applications; particularly because probing ligand structure is experimentally difficult./nWe approach this problem by performing atomistic computer simulations of alkyl ligands on a semiconducting nanocrystal facet to elucidate their phase behavior at different temperatures and solvent conditions. These simulations provide a detailed description of the structure of the ligand molecules, specifically providing insight into the order-disorder transition they undergo as the temperature is varied. This phase transition changes the arrangement of the surface ligands, affecting how a nanoparticle interacts with solvent and other nanoscale objects in its environment. We proceed to map the observed statistics of ligand orientation onto a coarse-grained field theoretic model of the ordering transition, which is parametrized by physical properties obtained from simulation data. By extracting the underlying physics of the transition and removing irrelevant atomistic details, this coarse-grained model considerably reduces computational costs, while still describing the collective behavior of ligand molecules on a nanoparticle surface. This new understanding can be leveraged to describe ligand ordering when multiple nanoparticle surfaces are close to each other and its effect on the phase behavior of ligand passivated nanocrystals.

Advisor: Geissler, Phillip L
Spatiotemporal signaling dynamics evoked by single binding interactions between a peptide-bound MHC molecule and a T cell receptor

T cells (TCs) have the crucial immunological task of discriminating foreign peptide fragments from endogenous (self) peptide fragments. This recognition is carried out by the T Cell Receptor (TCR) on the TC surface, which binds to an antigen-derived peptide fragment presented by major histocompatibility complex (pMHC) on the surface of an Antigen Presenting Cells (APC). Despite the centrality of this TCR:pMHC interaction and the myriad techniques used analyze it, few studies exist in which the signaling consequences of individual TCR:pMHC binding events have been determined. Direct examination of the outcomes from single TCR:pMHC encounters provides insight into how the stochastic signaling network of the T cell performs crucial tasks such as signal integration and ligand discrimination. In Chapter 1, individual TCR:pMHC binding interactions (dwell times) are mapped to two proximal events in T cell activation: the assembly of Linker for Activation of T cells (LAT) molecules; and, translocation of Nuclear Factor of Activated T cells (NFAT). After TCR engagement with agonist pMHC, the LAT scaffold protein forms a hub of signaling from which a number of subsequent signaling steps are initiated; hence, LAT assembly is a gatekeeper of downstream signaling. I observe that the probability of LAT assembly formation, localized to ligated TCR, is an increasing function of the dwell time of the TCR:pMHC interaction, suggesting that the formation of LAT assembly from ligated TCR represents a form of kinetic proofreading; however, the size and lifetime of a LAT assembly is independent of the TCR:pMHC dwell time interaction that produced it. This discreteness of LAT clustering from TCR:pMHC dwell time has consequences for signal integration from multiple binding events. In Chapter 2, I explore what distinguishes a productive TCR:pMHC binding event from one that fails to trigger LAT assembly, as an approach to delineate the “kinetic bottlenecks” in antigen discrimination and T cell activation. I found that activation of zeta-chain- associated protein kinase of 70 kDa (ZAP-70), which phosphorylates LAT at multiple sites, is necessary, but insufficient. Aside from ZAP-70 activity, diffusive phospho-LAT requires an additional event to trigger aggregation. Importantly, I found that, at low pMHC densities, PLC-γ1 controls the timing for the initiation of LAT clustering, a dependency not previously identified. One feature I readily observed in my experiments is that LAT assemblies can form without any apparent originating pMHC. The composition and function of these apparent orphan LAT assemblies are investigated preliminarily in Chapter 3. In summary, by measuring the correlation between single receptor (TCR)-ligand (pMHC) binding events and subsequent steps in T cell activation, one obtains unprecedented quantitative insight into the stochastic nature of signal transduction in T cells.

Advisor: Groves, Jay T
Geometry, Dynamics, and Emergence: Cowrie Form, Image Geometry, and Coupled Subcritical Oscillations

Living Systems are dynamically controlled by processes that they themselves create: here we study the emergence of the sophisticated control regimes in models of biological systems. A major route to understanding in Biology today is discovering which genes lead to what, almost always neglecting a story for how the genes achieve their ends. From an understanding perspective this is disappointing, and we strive to make more holistic models which try to get at the underlying nature of biological logic. Towards this end, we notice geometric regimes in cowrie growth and work towards a falsifiable and explanatory mechanistic model, aiming to make the case for the importance of mechanics and dynamics in development. We also present the first systematic study of globally-coupled subcritical limit cycle oscillators, exploring a rarely remarked upon dynamical regime. This regime is biologically interesting as it has bistability between oscillations and quiescence and is a simple excitable media which could be used as a reduced neural model. I am interested in clustering in the system as an example of symmetry breaking in identical systems; small differences in initial conditions lead to differentiation of the oscillators into particular varieties, analogous to cell fate decisions. Progress on these problems works towards illuminating the biological approach to self-assembly.

Advisor: DeWeese, Michael R
Approximation and Control of Skill Based Parallel Service Systems with Homogeneous Service

A skill base parallel service system is comprised of a set of customers of different classes that arrive randomly for service, a set of servers that serve those customers and a set of qualifications that defines which customer classes can be served by which server. Systems of this kind appear in a wide range of applications from the assignment of jobs to employees with different skills to network traffic routing. Literature regarding these systems has almost exclusively been focused on the asymptotic heavy traffic regime. The reason being that such an asymptotic regime is convenient to analyze and allows the derivation of exact results. However, although many applications can be well approximated by an asymptotic regime, many others can not. In this work we are especially concerned with large scale sparse systems where, despite the system being large of scale, each customer class can only be served by a small subset of the servers. After laying foundations for the model in Chapter 1 and exploring structural properties in Chapter 2 we go on to present the two main contributions of this work. In Chapter 3 we develop a set of approximations that compile to a , first of its kind, approximation scheme of matching rates of skill based parallel service system operating under the \textit{first-come-first-serve} or \textit{longest-queue-first} policies. The accuracy of the approximation is verified with extensive simulation experiments where it is shown to provide matching rate estimates with an absolute error of $3\%-5\%$ for a wide range of traffic intensities. Later, in Chapter 4 we use insights provided by the new approximation to derive weighted versions of the \textit{first-come-first-serve} or \textit{longest-queue-first} and show, through comprehensive simulation testing, that these weighted polices dramatically reduce the waiting time of customers in congested system compared to the original unweighted versions. Finally, we extend the use of the weighted policies to systems with matching rewards and show that, by appropriate choice of weights, these policies can be used by a controller to efficiently trade-off between the rate of reward accumulation and waiting time experienced by the customers

Advisor: Leachman, Robert S
Micro- and Nanofabrication of Polymeric Devices and Films for Oral Drug Delivery Applications

Oral drug delivery is the preferred route of administration due to its convenience to patients, low cost, and high patient compliance. However, the oral delivery of small molecules and protein therapeutics face physiological challenges that result in low drug solubility, poor absorption, and metabolic breakdown. This dissertation work describes the development of micro- and nanofabrication techniques to create drug delivery platforms that are designed to overcome these barriers. Micron-scale devices with planar, asymmetric geometries were fabricated using biocompatible materials with photolithography and inkjet printer techniques. These properties enhance device adhesion in the small intestine and are designed for unidirectional drug release toward epithelial tissue to release drug at high concentration and prolong drug exposure. Drug cargo comprising of either small molecules or peptides were efficiently loaded into microdevices with little waste using the inkjet printing approach and were capped with enteric or mucoadhesive polymers to control the rate of drug release in simulated intestinal environments. Finally, nanostructured surfaces were investigated as a means to enhance drug permeation across the intestinal epithelial barrier. Together, these results demonstrate how micro- and nanofabrication approaches can be used to overcome oral drug delivery challenges.

Advisor: Desai, Tejal A