VictorJuiz/thesis huggingface dataset:
Regge Calculus as a Numerical Approach to General Relativity

A (3+1)-evolutionary method in the framework of Regge Calculus, known as "Parallelisable Implicit Evolutionary Scheme", is analysed and revised so that it accounts for causality. Furthermore, the ambiguities associated with the notion of time in this evolutionary scheme are addressed and a solution to resolving such ambiguities is presented. The revised algorithm is then numerically tested and shown to produce the desirable results and indeed to resolve a problem previously faced upon implementing this scheme. An important issue that has been overlooked in "Parallelisable Implicit Evolutionary Scheme" was the restrictions on the choice of edge lengths used to build the space-time lattice as it evolves in time. It is essential to know what inequalities must hold between the edges of a 4-dimensional simplex, used to construct a space-time, so that the geometry inside the simplex is Minkowskian. The only known inequality on the Minkowski plane is the "Reverse Triangle Inequality" which holds between the edges of a triangle constructed only from space-like edges. However, a triangle, on the Minkowski plane, can be built from a combination of time-like, space-like or null edges. Part of this thesis is concerned with deriving a number of inequalities that must hold between the edges of mixed triangles. Finally, the Raychaudhuri equation is considered from the point of view of Regge Calculus. The Raychaudhuri equation plays an important role in many areas of relativistic Physics and Astrophysics, most importantly in the proof of singularity theorems. An analogue to the Raychaudhuri equation in the framework of Regge Calculus is derived. Both (2+1)-dimensional and (3+1)-dimensional cases are considered and analogues for average expansion and shear scalar are found.

Keywords: Numerical Relativity
Regge Calculus
Advisor: Dyer, Charles C.
"Tears of Compunction": French Gothic Ivories in Devotional Practice

This dissertation presents a new perspective on the function of objects in late-medieval devotional practice through a study of the so-called Soissons group of thirteenth-century French Gothic ivories. These ivory diptychs were sophisticated tools constructed to guide the user through various spiritual exercises that led to prayer. The hitherto unexplained increase in the availability of ivory in mid-thirteenth-century France is accounted for by an alteration in the trade routes that brought elephant tusks from the Swahili coast of Africa to northern Europe: a newly-opened passage through the Straits of Gibraltar allowed a small amount of luxury goods to be shipped together with bulk materials necessary to the northern textile industries. The increasing supply required a revision of the structure of the thirteenth-century craft of ivory. The Soissons group, the first ivory diptychs fashioned during this time of growth in ivory markets, is subdivided into two sections. An itinerant master who traveled throughout the Picard region between 1235 and 1270 crafted the first group. Concurrently, three separate Parisian artists produced the second group based on a Picard model. This dissertation redates all the ivories substantially earlier than previously thought, conclusions which were attained through stylistic analysis. The dense Passion iconography shaped the diptychs’ function in private devotion. The narrative encouraged the viewer to practice a number of spiritual exercises—reading, memorization and compunction—analogous to the three reasons for allowing images in the Christian Church, the triplex ratio. The Passion diptych format introduced with these objects was immensely popular throughout the thirteenth and fourteenth centuries and its conservation over time underscored its effectiveness. The small differences in iconography and composition among the seven Soissons diptychs, however, were subtle modifications to adjust to different audiences and to hone the objects’ efficacy as tools for prayer.

Keywords: Ivory
Medieval Art
Prayer
Trade Routes
Connoisseurship
Style
France
Thirteenth Century
Canons
Picardy
Paris
Spiritual Exercises
Private Devotion
Advisor: Cohen, Adam S.
Age-related Changes In Emotion Regulation Using A Startle Modulation Paradigm

Lifespan theories of emotion suggest that the ability to regulate emotion improves with age. The supporting evidence, however, is indirect: older adults pay less attention to negative events, remember less negative information, and report fewer experiences of negative emotion. Few studies directly measure emotion regulation by explicitly instructing older adults to modulate their feelings while exposed to emotion-evoking stimuli. The purpose of this thesis was to directly compare younger and older adults in their ability to modulate feelings to investigate whether aging results in decline, stability, or improvement in emotion regulation and also to examine potential mechanisms underlying regulation skills. The study employed a startle modulation paradigm to measure both emotional reactivity and regulation. Two experimental tasks (Stroop colour-word interference, reversal learning) were also administered to explore the relationship between emotion regulation and two theoretically-relevant processes: (a) cognitive control and (b) modification of learned emotional associations. There were three main findings: (1) emotional reactivity was preserved in older adults. Both age groups showed emotion-modulated startle (negative > neutral) during the pre-regulation viewing period; (2) age-related decline in emotion regulation was evident on an objective measure of emotion regulation (startle eyeblink reflex) but not on a subjective measure (self-ratings). Specifically, for older adults, startle eyeblink was not enhanced or attenuated following increase and decrease instructions, respectively. In contrast, both groups showed similar modulation of valence and arousal ratings by regulation instruction (increase > look > decrease); (3) for older adults, reversal learning performance correlated positively with the degree of reappraisal-related startle attenuation in the decrease condition, suggesting a possible mechanism for impaired down-regulation. These findings suggest that even when emotional reactivity is similar, older adults are less effective at modulating their physiological responses.

Keywords: emotion regulation
aging
startle modulation
Advisor: Stuss, Donald
The Operatic Imperative in Anglo-American Literary Modernism: Pound, Stein, and Woolf

It is generally agreed that modernism is a period and movement rich in interdisciplinary collaboration. What is often contentious in understandings of the modernist period is to whom modernist artists addressed their projects. On the one hand, traditional scholarship has tended to view modernism as an essentially elitist project practiced among a closed set orbiting around British and American expatriate coteries: Ezra Pound and his “Ezuversity,” Stein and her Paris Salon, Woolf and the Bloomsbury circle. On the other hand, recent scholarship in modernism has sought to expand the field to included modernisms practiced in different time periods, in different countries, and by a wider range of artists. While my project is firmly situated in the work of the so-called high modernists, my operatically focused approach, which sees Pound, Stein, and Woolf engaging directly with mass culture by way of opera (albeit in different ways and to different aims), suggests that we need to re-think the way in which we have mythologized the period, even where these “high” modernists are concerned. In chapter one, I read Pound’s operatic endeavors as alternative means of translation. Though these pedagogical projects valorize the art they “translate” for its unique difficulty, the use of opera and later, radio opera, as the means to translate this art demonstrates an interest in democratizing this difficulty. This is a remarkable inconsistency given Pound’s undisputedly fascist allegiances. Chapter two, which focuses on Stein’s Four Saints in Three Acts, shows how the prospect of writing an opera helped Stein to forge a new connection between playwright and audience in the theatre. What I am calling the “envoiced landscape” is an anti-patriarchal, enabling alternative to teleologically driven narrative that defeats authorial control by way of play. Chapters three and four turn to Woolf’s conspicuously hybrid novels, The Waves and Between the Acts. Both works question the nineteenth-century notion of music’s capacity to transcend language, embracing instead a distinctly operatic frame of reference, as Woolf celebrates the novel as an omnivorous but democratic, open-ended, contingent form, endlessly capable of incorporating and co-opting other genres. Whereas The Waves enacts a critique of the Gesamtkunstwerk played out on the Wagnerian stage, Between the Acts considers the social text played out among opera’s audiences, positing, then critiquing, a Brechtian reevaluation of Wagnerian aesthetics.

Keywords: modernism
opera
Advisor: Hutcheon, Linda
The Influence of Sulfide Stress Conditions on the 34S-isotope Enrichment in Sulfate During Dissimilatory Sulfate Reduction

The purpose of this thesis was to experimentally investigate the influence of increasing sulfide concentrations on the 34S isotope enrichment in sulfate during dissimilatory sulfate reduction (DSR). Two independent batch culture experiments with different maximum sulfide concentrations of up to 20 mM in the first and up to 40 mM in the second experiment were conducted using the marine sulfate reducer Desulfobacter latus. A comparison of the results from both experiments revealed a distinct offset towards more positive δ34S(SO42-) values in the 'high-sulfide' experiment, compared to the 'low-sulfide' experiment. While a Rayleigh type fractionation model was able to match the slopes - i.e., enrichment factors - of both experiments, it failed to reproduce the proper y-axis intercept in the 'high-sulfide' experiment. I therefore propose a new fractionation model that allows for a backward flow of ambient H2S into the bacterial cell and a subsequent enzymatically mediated oxidation of H2S to sulfate. The new backward flow increases with elevated H2S concentrations and is described as a first order rate constant. Unlike a Rayleigh type fractionation model, my model explains the slope and y-intercept of both experiments with a single parameter set. The new model with H2S-reflux further suggests that it can be used to determine growth kinetic parameters like the half-saturation constant through δ34S measurements. These findings support the hypothesis of microbially mediated, bi-directional S-fluxes between oxidized and reduced sulfur species. Because the S-transport during DSR appears to be bi-directional, great care must be taken when evaluating culture experiments with a Rayleigh type fractionation model, owing to the fact that an evident S-backward flow violates the prerequisites for applying the Rayleigh model. A variable S-backward flow results in variable enrichment factors which increased from -11 (no H2S) to ≈-17 ‰ (40 mM of H2S) in my experiments. I show for the first time the significance of a bi-directional H2S transport across the cell membrane during DSR and its consequences for the 34S-isotope fractionation in sulfate.

Keywords: Stable Isotope
sulfur isotope
sulfate reduction
isotope fractionation
fractionation
non-Rayleigh
sulfate reduction and fractionation model
Desulfobacter latus
S-isotope
sulfate
Advisor: Wortmann, Ulrich
The Role of BERP in Mammalian Systems

p53 functions as an important tumour suppressor through its ability to regulate a number of important cellular processes such as cell cycle arrest, apoptosis, DNA repair, senescence, and angiogenesis. An in vivo genetic modifier screen performed using Drosophila melanogaster resulted in the identification of D. melanogaster brain tumour (brat) as a putative modifier of of the p53 small eye phenotype. Mammalian homologs of brat are members of the tripartite motif family that contain a c-terminal NHL domain. We focus on elucidating the in vivo role of one such homolog, BERP, through the generation and characterization of a classical gene-deletion mouse mutant. We report that BERP-deficient mice exhibit enhanced learning/memory, increased fear, impaired motor coordination, and increased resistance to PTZ -induced seizures. Electrophysiological and biochemical studies show a decrease in mIPSC amplitude along with a decrease in cell surface expression of gamma2 subunit-containing GABA A receptors in the brains of BERP-deficient mice. In addition, no effect of genotype is apparent when examining BERP mRNA levels in the brain. This suggests that the decreased cell surface expression of gamma2 subunit-containing GABA A receptors is likely a posttranscriptional phenomenon and supports the possibility that BERP may be involved in the intracellular trafficking of GABA A receptors. In investigating the possible relationship between BERP and p53, we identify the presence of a transcriptionally competent p53 response element within the first intron of the human BERP genomic locus and demonstrate that the BERP expression is up regulated in a p53-dependent manner both in vitro and in vivo. These results support the interpretation that BERP is a novel p53-regulated gene and suggest a new role for p53 in the regulation of GABA A receptor trafficking and epileptogenesis.

Keywords: genetics
mouse model
gene regulation
Advisor: Mak, Tak Wah
Quand l'Autre prend la parole. La représentation de trois formes d'altérité dans le roman contemporain.

La notion d’altérité circule avec insistance dans la conscience collective contemporaine, mais, à ma connaissance, il n’y a pas d’ouvrage critique qui aborde simultanément la spécificité de différentes sortes d’altérité dans la fiction pour en saisir les formes, la signification et les enjeux, surtout à partir de la perspective de l’Autre. Ce travail organise l’étude de la représentation de trois formes d’altérité dans six romans contemporains français, québécois et francophones dans lesquels l’Autre est le sujet du discours : 1. L’étranger : La dot de Sara (Agnant, 1995) et Un aller simple (van Cauwelaert, 1994) ; 2. La folie : Moha le fou Moha le sage (Ben Jelloun, 1978) et La chaise au fond de l’œil (Aude, [1979] 1997) ; 3. La pauvreté : L’exil aux portes du paradis (Dahan, 1993) et Conte d’asphalte (Calife, 2007). Mon objectif principal est de cerner la représentation textuelle de ces formes d’altérité ainsi que leur rôle et leur signification quand la diégèse adopte la perspective d’un personnage qui exprime lui-même sa dissemblance et son aliénation potentielle. Quand l’Autre prend la parole, son statut est entièrement bouleversé, car il ne s’agit plus d’une représentation « traduite » de son expérience ou d’une appréhension de ce personnage par un tiers. Mon travail révèle selon la perspective du marginalisé soit une transformation dans la signification de l’altérité soit un brouillage des frontières entre la marge et le centre qui remet en question, dans certains cas, l’existence même de l’altérité. Cette étude dégage également les caractéristiques discursives communes et distinctives des formes de l’altérité. En outre, elle met en lumière l’instabilité du statut Autre dans le texte romanesque : ce statut peut évoluer, se transformer et parfois même disparaître alors que, dans d’autres circonstances, il peut être un facteur identitaire incontournable et immuable. La multiplicité de ces variations illustre la complexité de chaque manifestation d’altérité et la flexibilité de la notion que le roman d’expression française utilise de façon centrale et critique. Cette thèse contribue ainsi à l’enrichissement de notre compréhension de l’exploitation littéraire des formes de l’altérité, phénomène qui marque de manière importante la littérature contemporaine.

Keywords: alterity
foreigner
insanity
poverty
first-person narratives
Francophone literature
French literature
Québec literature
otherness
Advisor: Paterson, Janet
Donne and the Sidereus Nuncius: Astronomy, Method and Metaphor in 1611

John Donne’s poetry has long been famous for its metaphysical conceits, which powerfully register the impact of the “New Philosophy,” yet the question of how his work is implicated in the new forms of knowledge-making that exploded in the early seventeenth century has remained unanswered. “Donne and the Sidereus nuncius” examines the relation between method and metaphor on the cusp of the Scientific Revolution by reading the poetry and prose of Donne in the context of developments in early modern astronomy, anatomy and natural philosophy. I focus primarily on two texts, Ignatius, his Conclave (1610) and the Anniversaries (1611-2), which are linked not only by chronology, but also by their mutual concern with the effects of distorted perception on the process of understanding the universe. Written directly after the publication of Galileo’s Sidereus nuncius (1610), these works offer a historicized perspective on Donne’s changing use of scientific metaphor in relation to the transformative crux of the discovery of the telescope, which provided a startling new optical metaphor for the process of knowing. In this context, “Donne and the Sidereus nuncius” considers the conceptual work performed by scientific metaphor as part of an ongoing transformation from emblematic to analogic figuration. Donne’s search for material that is, in his phrase, “appliable” to other subjects, depends on an analogic conception of metaphor, a comparison that enables new thinking by identifying underlying commonalities between disparate objects. Building on this understanding of metaphor as comparative, I examine Donne’s self-conscious use of metaphors of methodical knowledge making—invention, innovation, anatomy and progress—in the context of instrumental metaphors, such as the telescope, spectacles, perspective, and travel narratives. In doing so, I suggest that Donne’s metaphorical conceits explore the conflict between scientific attempts to discern order in nature and the distorting effects of methodological frameworks imposed on the object of analysis.

Keywords: Poetics
Astronomy
Early Modern
Metaphor
Advisor: Harvey, Elizabeth D.
An FPGA-based Real-time Simulator for the Analysis of Electromagnetic Transients in Electrical Power Systems

A physical control/protection platform needs to be tested and its functionality verified prior to installation and commissioning. Closed-loop testing of a physical control/protection platform, in a real-time simulator environment is practically the only option to safely and thoroughly verify the design integrity and evaluate its functionality and performance. Moreover, a real-time simulator is also required to conduct statistical switching studies, as it substantially reduces the total run time of the study. This thesis proposes and develops a generalized methodology for implementation of the power system equations in the FPGA environment. The developed methodology enables real-time operation, for closed-loop testing of physical control/protection platforms in hardware-in-the-loop (HIL) configuration, and even faster-than-real-time operation, for statistical switching studies. Based on the developed methodology, an FPGA-based simulator is developed and tested. The salient features of the proposed implementation are: ² It enables the use of a nanosecond range simulation time-step to simulate large systems in real-time, in contrast to the us range time-steps used in the existing simulators. Thus it is also able to provide a wide frequency bandwidth for the simulation results. ² It retains the calculation time, within each simulation time-step, nearly fixed irrespective of the size of the system. ² It eliminates the need for the corrective measures, adopted in the existing real-time simulators, to reduce error due to the lack of synchronization between the simulation time-grid and the output signals of the control/protection platform under test. As an integral part of this work, this thesis proposes and develops the modified two-layer network equivalent (M-TLNE). The salient feature of the M-TLNE is its computational efficiency, as compared to the existing network equivalents, which makes it a prime choice for statistical switching studies and real-time simulation of electromagnetic transients. This thesis also proposes a generalized methodology, applicable to both single and multi-port network equivalents for both single- and multi-phase systems, for developing the proposed M-TLNE. The developed methodology ensures the stability and passivity of the M-TLNE.

Keywords: Real-time Simulation
Power systems
FPGA
Advisor: Iravani, Mohammad Reza
The Effect of Lifelong Musicianship on Age-related Changes in Auditory Processing

Age-related declines in hearing abilities are common and can be attributed to changes in the peripheral and central levels of the auditory system. Although central auditory processing is enhanced in younger musicians, the influence of lifelong musicianship on age-related decline in central auditory processing has not yet been investigated. Therefore, the purpose of this dissertation was to investigate whether lifelong musicianship can mitigate age-related decline in central auditory processing. In the first experiment, age-related declines on four hearing assessments were compared between musicians and non-musicians. Speech-in-noise and gap-detection thresholds were found to decline at a slower rate in musicians, providing an increasing advantage with age. Furthermore, musicians had a lifelong advantage in detecting a mistuned harmonic, although the rate of age-related decline was similar for both musicians and non-musicians. Importantly, there was no significant effect of musicianship on pure-tone thresholds, suggesting that lifelong musicianship can mitigate age-related decline in central but not peripheral auditory processing. To test this hypothesis, a second experiment compared auditory evoked responses (AERs) between groups of older and younger musicians and non-musicians. Results indicated that exogenous neural activity was enhanced in musicians, but that age-related changes were similar between musicians and nonmusicians. Furthermore, endogenous, attention-dependent neural activity was enhanced in older adults, suggesting a compensatory cognitive strategy. Importantly, endogenous activity was preferentially enhanced in older musicians, suggesting that lifelong musicianship enhanced cognitive processes related to auditory perception. In the final experiment, the ability to segregate simultaneous sounds was tested in older and younger musicians and non-musicians by using a mistuned harmonic paradigm, where AERs to harmonic complexes were compared to AERs when one of the harmonics was mistuned. Results indicated that musical training in older adults has little effect on early automatic registration of the mistuned harmonic. In contrast, late attention-dependent activity, associated with the perception of the mistuned harmonic as a separate sound, was influenced by musical training in older adults, suggesting that lifelong musicianship preserves or enhances cognitive components of concurrent sound segregation. In summary, musical training was found to reduce age-related decline in hearing abilities due to enhanced central processing of auditory information.

Keywords: aging
auditory processing
music
hearing
EEG
age-related hearing loss
Advisor: Alain, Claude