VictorJuiz/thesis huggingface dataset:
Shaking the whole system of things : catastrophe and continuity in romantic narrative

This dissertation reconsiders the relationship between literature and conceptions of historical time in the Romantic period, arguing that many of British Romanticism's most significant literary innovations developed as responses to pervasive cultural anxieties about the relationship between past and present. As critics from Georg Lukàcs to James Chandler have argued, Europe in the early decades of the nineteenth century witnessed the emergence of the "historicist" worldview, according to which individual and collective subjects see themselves as existing both in and as history (rather than as embodiments of a timeless, universal human nature or nodes in a divinely-ordered system). If the seemingly never-ending cycles of revolution and war that engulfed Britain and Continental Europe after 1789 contributed to historicism's development and diffusion by making history a matter of concern for everyone, they also created a widespread and unsettling sense of rupture and disconnection—between thoughts and feelings, individuals and collectives, and, most importantly, past and present. Taking three major works of Romantic literature as case studies, I explore literary responses to this sense of rupture as they are articulated in relation to the two poles I call "catastrophe" (i.e. a radical break between one historical moment and the next) and continuity (i.e. a smooth flow or even identity between historical moments). Published within a few years of each other, Walter Scott's Waverley, or 'Tis Sixty Years Since (1814), Jane Austen's Persuasion (1817), and Lord Byron's Childe Harold's Pilgrimage (1812-18) represent some of Romanticism's most influential contributions to British literature, including the new genre of the historical novel, the Byronic hero and his quest, and the rapid advance of realism in fiction. The chronological proximity of these three works, I argue, reveals a cultural moment in which historicism had not yet congealed into a secure, dominant structure of thinking and feeling. All three depict the past/present relationship as either extreme (i.e. excessively catastrophic or excessively continuous) or paradoxical (i.e. catastrophically continuous); all three, likewise, remake established formal, generic, thematic, and stylistic models in order to capture and communicate these unfamiliar varieties of temporal experience. The very ambivalence of these texts provides them with a degree of reflective distance on the broader culture of Romantic historicism. As I demonstrate across my three chapters, Scott, Byron, and Austen offer, in their own unique ways, profound meditations not only on historicism's fundamental concepts and categories, but also on the very nature and significance of history itself, on the human experience and consciousness of time, and on the role of memory in individual and collective life.

Advisor: Bender John B. 
Woloch Alex
Duncan Ian
Shank and zinc mediate an AMPA receptor subunit switch in developing neurons

Autism Spectrum Disorders (ASDs) are a group of neurodevelopmental disorders characterized by social communication deficits and restricted or repetitive behaviors. Despite the growing number of diagnosed children worldwide (from 1 in 150 in 2000 to 1 in 59 in 2014), there are no effective pharmacotherapies, underscoring the need to study the underlying biological mechanisms. Twin and family studies have emphasized the high heritability of ASDs (~ 40 %). Further genetic analyses have revealed over 100 genes linked to ASDs, many of which encode for synaptic proteins and affect the function of excitatory synapses, including members of the Shank family of postsynaptic proteins. While the genetic heritability of autism is high, environmental factors (such as prenatal zinc deficiency) might promote the development of ASDs. Intriguingly, zinc has been shown to be an important regulator of synaptic function and to bind and activate two Shank family members (Shank2 and Shank3), suggesting that zinc deficit may impair synaptic function by compromising the activation of Shank proteins by inducing conformation changes or affecting the interaction between Shanks and other synaptic molecules. At present, the means through which zinc and Shank proteins modulate synaptic function is unclear. Studies outlined in this dissertation explore whether zinc and Shanks mechanistically regulate the activity of AMPA receptors (AMPAR), a major group of glutamate receptor mediating the majority of excitatory synaptic transmission in the nervous system. My results show that the zinc-sensitive Shank proteins (Shank2 and Shank3) exhibited increased synaptic localization during early development in a similar manner to that of GluA2, suggesting both molecules might play roles in synaptic AMPAR maturation. As an initial test of this hypothesis I examined whether neural activity regulates the levels of postsynaptic zinc at glutamatergic synapses, and whether this activity is associated with the localization of Shanks and AMPAR. Using live-cell imaging, I found that K+-induced neuronal depolarization elevated postsynaptic zinc transiently and reversibly. This elevated zinc was found to enhance synaptic efficacy by recruiting GluA2 to Shank-dependent synapses. Importantly, loss of either Shank2 or Shank3 function abolished the zinc-induced enhancement of AMPAR-mediated transmission, suggesting that Shanks are critical mediators of a zinc-AMPAR signaling. Together, these data provide a mechanistic link between genetic mutations in Shanks and prenatal zinc deficiency in the etiology of ASD.

Advisor: Huguenard John 
Ding Jun (Jun B.) 
Garner Craig 
Madison Daniel V.
Shape modeling and variability mapping in human brain structures

This thesis is about modeling and understanding the variability in shape of different brain structures and how these variabilities relate to function, health and disease. As the capabilities of imaging methods increase in resolution and accuracy, worldwide efforts are now focused on acquiring neuroimaging data of large human populations, both normal and abnormal, and making this data available to the scientific community. The data from these massive datasets is processed to extract three-dimensional representations of the different structures in the human brain in-vivo. At present, the neuroscientific community lacks the geometric language to analyze and model shape variations in these structures across populations. While statistical atlases of average brain shapes provide an understanding of what is accepted as 'normal' and 'abnormal', more precise modeling methods are needed for better quantification and understanding. The goal of this thesis is to equip the neuroanatomist with a precise language for assessing neuroanatomical geometric variations. To this end we describe the following contributions: (1) Framework for classification of different stages of Alzheimer's disease based solely on the geometry of an ensemble of brain structures. Our approach uses statistical learning, achieves high classification accuracy and is sensitive to identifying the onset of Alzheimer's disease; (2) Training a neural network to classify Alzheimer's disease based on structural (T1-MRI) and functional (PET) imaging data; (3) Two different geometric models to capture the shape of white matter fiber bundles. We show several applications of these models, including fiber bundle registration, shape atlas and shape differences measure and derive a normative model for white matter development in the pediatric brain.

Keywords: Electrical Engineering.
Advisor: Guibas Leonidas J. 
Horowitz Mark (Mark Alan) 
Wandell Brian A.
Sharpening the Tip of the Spear: Evaluating technology integration in Special Operations Forces

US Special Operations Forces (SOF) carry a renowned reputation for excellence as the most sophisticated warfighters on the planet. The common narrative surrounding SOF contends that SOF employ tactical flexibility, highly specialized training, and advanced technological systems to achieve remarkable battlefield successes; this wisdom is well-earned. But high operational tempo and extended deployments during the Global War on Terror (GWOT) may have unintended consequences for SOF technology acquisitions. In interviews with current and former SOF operators, many expressed frustrations with select technologies, which sharply contrasts SOF’s reputation for agile and effective acquisitions. The thesis draws on extensive interviews with operators, USSOCOM officials, and national security experts, as well as data on USSOCOM acquisitions and a case study examination of the RQ-20 Puma drone system. Taken together, the evidence suggests that SOF’s sustained high operational tempos has changed USSOCOM acquisition, slowly moving SOF acquisitions closer to the behaviors of the Services. This surfaces in three early warning indicators. First, USSOCOM Acquisition, Technology, and Logistics (AT&L) has grown, evidencing a greater jurisdiction of the Program of Record system. Second, SOF across USSOCOM have pursued alternative acquisition methods, betraying a growing disconnect between operator needs and AT&L acquisitions. Third, USSOCOM’s sustained acquisition of the RQ-20 indicates an inability to keep pace with commercial alternatives in select technological domains, to the detriment of operators. This thesis concludes with a discussion of considerations for the optimal composition of acquisitions teams, to mitigate the root causes driving SOF acquisitions behavior towards that of the Services.

Keywords:  Center for International Security and Cooperation
Center for International Security and Cooperation
special operations forces
SOF
USSOCOM
acquisitions
technology
Thesis
Advisor: Zegart Amy
Silicon based arrays : from millimeter wave communications to wireless power transfer

This thesis presents the application of millimeter wave silicon integrated circuits towards high data rate wireless communications and wireless power transfer (WPT). Power generation in the D-band is challenging due to device limitations, therefore we present a SiGe transmitter that is fully packaged with a dielectric rod antenna-in-package that provides EIRP greater than 15 dBm at 135 GHz and consumes 366 mW. Next, we propose WPT in the radiative near-field using electrically large phased arrays. The trade-offs of this approach are analyzed to optimize an antenna array over frequency. Finally, a 4-channel Ka-band transmitter beamformer was fabricated on TSMC's 65nm CMOS technology, and is meant for large scalable arrays. Since the cost of the array is partly driven by the electronics, the beamformer architecture aims to reduce the overall chip area using a traveling wave distribution network. The proposed RFIC consumes 1.65 mm2 of die area and 320 mW (84 mW/element).

Keywords: Electrical Engineering.
Advisor: Lee Thomas H.
Arbabian Amin 
Zambre Yadunath
Simulating suspended sediment dynamics in shallow-water wave- and current-driven environments

Sediment dynamics driven by waves and currents in shallow-water estuarine environments impacts many physical and biological processes and is important to the estuary-wide sediment budget. However, observational restrictions have limited our ability to understand the physics governing sediment entrainment and mixing in these environments. Nonlinear interactions between waves and currents, and sediment-induced stratification, result in complex near-bed physics that impacts the vertical transport of both mass and momentum throughout the water column. An Eulerian based sediment transport model is developed, along with a method for reducing the spin-up time for turbulent channel flow simulations. With proper initial conditions, the method leads to over a factor of six savings in the computational expensive associated with spin-up relative to traditional methods. Direct numerical simulation is then applied to study wave, current, and sediment interactions in combined wave- and current-driven flows with low Reynolds number (laminar) waves. Simulated conditions are relevant to wind-waves propagating into shallow-water, fine sediment environments. In contrast to the effects of high Reynolds number waves, low Reynolds number waves are found to accelerate currents by reducing vertical turbulent momentum transport. However, the wave velocity is unaffected by the currents, and resembles the Stokes theoretical wave solution for all conditions simulated. We also show that sediment entrainment and near-bed sediment dynamics are controlled by waves, although current-generated turbulence is required for vertical mixing. As is the case for steady currents, the downward settling flux is balanced by the upward turbulent flux throughout most of the water column. Near-bed sediment-induced stratification is also shown to suppress vertical transport of mass and momentum by stabilizing infrequent but intense mixing events. The stabilization reduces both the vertical Reynolds stress and vertical turbulent sediment flux, leading to accelerated currents and reduced suspended sediment concentrations. Near-bed reductions in vertical Reynolds stresses also reduce turbulence production but increase vertical shear. The increased shear acts as a feedback mechanism that eventually outweighs suppression of the Reynolds stress and increases turbulence production higher in the water column. Unlike mean shear, if the vertical turbulent sediment flux is restricted at any point in the water column, the magnitude of the mean suspended sediment concentration gradient decreases at all heights above the restriction. As a result, the effects of sediment-induced stratification on vertical turbulent sediment fluxes are more pronounced than on vertical turbulent momentum fluxes.

Advisor: Fringer Oliver B. (Oliver Bartlett) 
Koseff Jeffrey Russell 
Monismith Stephen Gene
Simulations of shock induced interfacial instabilities including materials with strength

The Richtmyer-Meshkov instability arising from the interaction of shock waves with material interfaces occurs in many natural and engineering contexts. It plays an important role in supersonic combustion, supernova explosions and presents a major roadblock in achieving sustained fusion in Inertial Confinement Fusion (ICF). The first part of the thesis focuses on high resolution simulations of the Richmyer-Meshkov instability that seek to deduce the effect of spatial inhomogeneity. Simulations performed with high order compact finite difference schemes are compared to experiments and show good qualitative and quantitative comparison. Analysis of the simulation results is focused on understanding the turbulence energy dynamics and mixing processes. A scale dependent coarse-graining approach is developed and used to decipher the energy dynamics in scale space. The coarse-graining analysis shows the effect of compressibility in inhomogeneous Richtmyer-Meshkov flows. A new mixing measure based on entropy generation by diffusive mass flux is introduced and evidence for a mixing cascade in scale space is presented. Results of energy and mixing scaling obtained from the simulations here are compared with experimental results of other inhomogeneous Richtmyer-Meshkov flows and similarities are drawn. In the second portion of the thesis, a new high order Eulerian method for simulating large deformation phenomena in solids as well as flow in liquids and gases in a unified manner is presented. The method uses an inverse deformation gradient tensor to track deformations and the hyperelastic formalism is used in order to maintain thermodynamic consistency. The accuracy and resolution properties of the method are demonstrated through one and two dimensional test problems. The method is extended to be able to simulate interactions between multiple materials using a diffuse interface approximation. The Richtmyer-Meshkov instability between copper and aluminum is simulated and a grid resolution study shows the superior resolution properties compared to previous methods. Finally, a new algorithm to treat sliding at material interfaces is presented in the context of a diffuse interface Eulerian method.

Keywords: Aeronautics and Astronautics.
Advisor: Lele Sanjiva K. (Sanjiva Keshava)
Alonso Juan José
Moin Parviz
Single Charge Sensitive High Voltage Phonon Detectors: Development and Applications to the Search for Dark Matter

Single charge resolution is demonstrated in a cryogenic silicon detector which measures the Neganov-Trofimov-Luke phonons created by drifting charges. This detector was created by instrumenting a 1 cm by 1 cm by 4 mm Si crystal with Quasiparticle-trap-assisted Electrothermal-feedback Transition-edge-sensor phonon sensors on one side and depositing an Al bias grid on the other. Using bias voltages of up to 160V, this detector ultimately achieved charge and phonon energy resolutions of down to approximately 0.07 fundamental charges and 10 eV, respectively. A discussion of the origins and reduction of spontaneous charge flow through the detector crystal ("leakage currents") is presented. Due to its low leakage rate and inherently fast response, this detector was able to probe new areas of electron-recoiling dark matter phase space in a 0.49 gd exposure. The uses of detectors of this type in the SuperCDMS SNOLAB experiment, and in general are also discussed.

Keywords:  Department of Physics
dark matter
silicon
detector
single charge
cryogenic
tes
transition edge sensor
luke
ntl
neganov
trofimov
phonon
cdms
supercdms
electron recoiling dark matter
dm
erdm
wimp
Stanford Nanofabrication Facility
SNF
Thesis
Advisor: Cabrera Blas
Manoharan Hari
Singularity and comparison theorems for metrics with positive scalar curvature

In this thesis, we discuss metric properties of positive scalar curvature. Metrics with positive scalar curvature naturally arise from various geometric and physical problems. However, some basic questions of positive scalar curvature were unknown. Specifically, can one conclude that the scalar curvature of a metric is positive, just based on measurement by the metric, without taking any derivative? Such questions are usually answered via geometric comparison theorems. They are also built upon a good understanding of the singular set, along which a sequence of metrics with uniformly bounded curvature degenerate. The primary contributions of this thesis are twofold: Firstly, we study the effect of uniform Euclidean singularities on the Yamabe type of a closed, boundaryless manifold. We show that, in all dimensions, edge singularities with cone angles ≤ 2π along codimension-2 submanifolds do not affect the Yamabe type. In three dimensions, we prove the same for more general singular sets, which are allowed to stratify along 1- skeletons, exhibiting edge singularities (angles ≤ 2π) and arbitrary L∞ isolated point singularities. Secondly, we establish a geometric comparison theorem for 3-manifolds with positive scalar curvature, answering affirmatively a dihedral rigidity conjecture by Gromov. For a large collections of polyhedra with interior non-negative scalar curvature and mean convex faces, we prove that the dihedral angles along its edges cannot be everywhere less or equal than those of the corresponding Euclidean model, unless it is isometric to a flat polyhedron. From the viewpoint of metric geometry, our results show that R ≥ 0 is faithfully captured by polyhedra. They suggest the study of "R ≥ 0" with weak regularity assumptions, and the limit space of manifolds with scalar curvature lower bounds.

Keywords: White, Brian, 1957- degree supervisor.
Mathematics.
Advisor: Schoen Richard (Richard M.) 
Luk Jonathan (Professor)
Sizing methodologies for aircraft with multiple energy systems

Electric aircraft have been a topic of significant interest, especially in recent years. A wide variety of different aircraft configurations that utilize electric propulsion at short ranges have been proposed and are currently under development. However, physical limits in battery technology have significantly hampered their entry-into-service. A proposed solution has been to use hybrid-electric or hybrid battery approaches that allow the user to leverage multiple energy systems with contrasting specific energy and specific power properties to allow for lighter, more feasible aircraft along with the opening of new regions in the design space. Many of the designs, particularly those that use distributed electric propulsion possess a complex trade-space that needs global optimization methods to properly evaluate. This dissertation develops a methodology for basic sizing of aircraft that enables the designer to employ global optimization methods at the earliest stages of the design process with substantial improvements in code speed, and, depending on the method used, robustness. Furthermore, it reveals an inherent weakness in developing and sizing electric and hybrid-electric aircraft that only use a single value for specific energy and specific power; the results here show representative cases where modeling off-design performance rather than simply taking a nominal value can reduce aircraft weight by as much as factor of two. This also illustrates that for electric aircraft, making intelligent design decisions in the earliest stages of the design process is much more crucial than in traditional designs where specific energy is not nearly as limiting. Additionally, it explores and diagnoses several unusual issues that may arise in the context of solving aircraft design problems that possess multiple energy systems, while offering algorithmic solutions that improve both code speed and robustness. More specifically, these designs show an unsettling characteristics in that, at the basic level, solutions to the aircraft sizing problem may be nonunique. Now, it should be noted that different methods are more susceptible to finding extraneous solutions which will be discussed in greater detail. Finally, it develops frameworks utilizing machine learning regression techniques that learn the trade space of sizing solutions, meaning that what may be computationally expensive calculations can be initiated from a nearly converged starting point.

Keywords: Aeronautics and Astronautics.
Advisor: Alonso Juan José
Cantwell Brian 
Kroo Ilan 
Saunders Michael A.
Skeletal muscle stem cell activation : aging and rejuvenation

Aging stymies wound healing. This is pronounced in skeletal muscle, a tissue repaired by muscle stem cells (MuSCs). In adults, MuSCs are normally quiescent but respond to muscle damage by activating and regenerating muscle fibers. In old organisms, MuSC activation is far less efficient, yet much is still unknown about mechanisms and potential mitigating strategies. In this thesis, we dissect the cellular events of activation in young and old MuSCs, uncovering an early delay, before S-phase, in old MuSC activation. We perform unbiased metabolomic and transcriptional profiling, discovering oxidative stress as a reversible cause of the slower activation of old MuSCs. Next, we test the hypothesis that voluntary exercise is a practicable intervention that can benefit old MuSCs and muscle repair. We demonstrate that exercise rejuvenates old MuSC activation and muscle regeneration ability in a cell-intrinsic manner. Molecular profiling followed by genetic manipulation of MuSCs in the contexts of aging and exercise reveals Cyclin D1 as a protein vital for MuSC activation that is decreased during aging and restored by exercise. In quiescent MuSCs, loss of Cyclin D1 liberates the pro-aging pathways TGFβ-Smad3 and NF-κB, whose pharmacologic inhibition ameliorates the activation deficits of old and genetically Cyclin D1-deficient MuSCs. In summary, this work combines molecular profiling and in vivo rejuvenation to discover new mechanisms of MuSC aging and strategies to improve old MuSC activation.

Advisor: Rando Thomas A.
Beachy Philip Arden 
Palmer Theo 
Sage Julien