VictorJuiz/thesis huggingface dataset:
Understanding the Earliest Stages of High-mass Star Formation

High-mass star formation, contrary to its low-mass counterpart, remains poorly understood. This project aims to constrain the mechanisms driving the formation of OB stars and their precursors with the analysis of two main fields: Aquila, observed by the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST), and the W3 Giant Molecular Cloud (GMC), provided by the Herschel Space Observatory and for which Canada has lead responsibility within the Herschel programme. The Aquila analysis, combining BLAST and interferometry data, presents a full characterization of the main high-mass star forming clumps in this field and their Ultracompact HII regions. We have found highly clustered environments, a range of evolutionary stages, and signatures of triggering within the parsec-scale clumps hosting OB stars. Our study of the W3 GMC comprises an analysis of the young stellar objects (YSO), the regions currently hosting on-going high-mass star formation, the environment, history, and compact source population. Spitzer data were used to identify, classify, and investigate the clustering properties of the YSO population. These complemented the Herschel datasets, with which we have produced column density and temperature maps, a full analysis of the probability density functions and mass distributions, and a catalog of reliable sources at ~ 36'' resolution. The clump sample was characterized and classified according to their stellar content, spectral energy distributions, the NH2/T maps, the L/M diagram, and various schemes presented in previous studies. Based on our environmental analysis and the unique intrinsic and stellar properties of the clumps hosting the clusters of high-mass stars in W3, we have proposed a new high-mass/cluster formation scenario based on external feedback from high-mass stars. This ‘convergent constructive feedback’ mechanism could not only explain the formation of clusters with an observed decreasing age (and increasing system/source mass) toward the innermost regions, but could also ensure the availability of material during cluster formation, explain the formation of rare Trapezium-like systems, and address various outstanding issues in high-mass star formation theory. New simulations and additional observations are now required in order to constrain the details and implications of this model.

Keywords: astrophysics
star formation
high-mass stars
massive stars
herschel telescope
blast telescope
Advisor: Martin, Peter
Palpable Politics and Embodied Passions:Terracotta Tableau Sculpture in Italy, 1450-1530

Polychrome terracotta tableau sculpture is one of the most unique genres of 15th-century Italian Renaissance sculpture. In particular, Lamentation tableaux by Niccolò dell’Arca and Guido Mazzoni, with their intense sense of realism and expressive pathos, are among the most potent representatives of the Renaissance fascination with life-like imagery and its use as a powerful means of conveying psychologically and emotionally moving narratives. This dissertation examines the versatility of terracotta within the artistic economy of Italian Renaissance sculpture as well as its distinct mimetic qualities and expressive capacities. It casts new light on the historical conditions surrounding the development of the Lamentation tableau and repositions this particular genre of sculpture as a significant form of figurative sculpture, rather than simply an artifact of popular culture. In terms of historical context, this dissertation explores overlooked links between the theme of the Lamentation, the Holy Sepulcher in Jerusalem, codes of chivalric honor and piety, and resurgent crusade rhetoric spurred by the fall of Constantinople in 1453. Reconnected to its religious and political history rooted in medieval forms of Sepulchre devotion, the terracotta Lamentation tableau emerges as a key monument that both reflected and directed the cultural and political tensions surrounding East-West relations in later 15th-century Italy. For the confraternity of Santa Maria della Vita in Bologna, Niccolò dell’Arca’s Lamentation represented an opportunity to resurrect the crusade origins of the sodality and establish the group as a major social and political voice within the city. For Guido Mazzoni’s princely patrons, Lamentation groups spoke of a devotion to the cause of the Holy Sepulchre and were used to craft aspects of a ruler’s political image that were rooted in traditional chivalric ideals of honor and religious duty. Polychrome terracotta is also discussed as the ideal medium to embody and communicate the immediacy of the piety, the grief, and the political and religious anxieties provoked by events in the East and engage viewers with the call to action at the heart of the Lamentation theme. Lastly, this project considers the relationship between Lamentation tableaux and the sacri monti, with the Sepulchral theme as their conceptual linchpin.

Keywords: terracotta sculpture
Italian Renaissance
Advisor: Sohm, Philip
Mechanisms of Smaug-mediated Post-transcriptional Regulation in the Early Drosophila Embryo

Post-transcriptional regulation of gene expression can be mediated by cis acting elements within mRNAs that are recognized by RNA binding proteins that control mRNA expression. Smaug is a highly conserved sequence specific RNA-binding protein that is essential for early Drosophila development. Smaug binds to well defined cis elements in target mRNAs and uses protein-protein interactions to recruit additional factors that regulate the bound mRNA. In this thesis I will describe my efforts to identify novel Smaug binding proteins to better understand the mechanisms of Smaug-mediated control. My efforts identified several Smaug binding partners including RNA helicases CG7878 and CG10077; Not1, a component of the CCR4/NOT deadenylase; and the miRISC component Argonaute 1. My work and the work of others suggests that CG7878 along with other RNA helicases could function with Smaug to regulate target transcripts. My identification of the Smaug/Not1 interaction was the basis for the discovery that Smaug induces transcript decay through recruitment of the CCR4/Not deadenylase complex. Finally, I employed both in vitro and in vivo experiments to show that Smaug can directly recruit Argonaute 1 to a target mRNA to repress its translation and that this recruitment does not require a miRNA. Argonaute 1’s interaction with the target mRNA requires the Dop kinase suggesting that phosphorylation by Dop of one or more proteins is required for Smaug-mediated recruitment of Argonaute 1.

Keywords: Smaug
Post-transcriptional regulation
Drosophila
Argonaute
nanos
Advisor: Smibert, Craig
Canada's Contribution to Neglected Tropical Disease Research: A Co-authorship Network Analysis

Objective: NTDs are a group of thirteen communicable diseases that thrive in impoverished settings and are a prime example of a global health issue in need of collaborative research solutions. The aim of this study was to design and apply an accessible yet systematic approach for analyzing the publication trends and collaboration structure of Canada’s neglected tropical disease (NTD) research network. Co-authorship network analysis is an emerging technique for understanding the complex dimensions and results of collaborative research. Methods: Multiple methods and measures were used to support this study including: an academic and grey literature review; a systematic bibliometric procedure (publication activity, quality, specializations and collaboration rates) and a co-authorship network analysis (network size, components, density, cliques, clustering, centralization and core-periphery) of countries and institutions contributing to Canada’s NTD research. Results: Over the past sixty years (1950-2010) there has been a notable increase in Canada’s NTD publication activity. Canada’s NTD researchers specialize in Leishmania and African sleeping sickness research and are mainly affiliated with academic institutions within Canada (McGill University, Laval University and University of British Columbia). International co-authorship activity is largely with OECD countries (United States, United Kingdom and France) and some non-OECD countries (Brazil, Iran, and Peru). The core of Canada’s NTD research network includes a tightly connected group of OECD countries and two African countries (Uganda and Kenya). The countries on the periphery of the network are predominantly non-OECD countries which fall within the networks lowest GDP percentile. Canada’s Leishmania research network is regionally clustered with central ‘bridging’ and ‘bonding’ institutions. This contrasts to the more permeable structure of Canada’s African sleeping sickness institution network. Conclusion: The methods and findings from this study implicate Canada’s global health research and institutional policies. The findings suggest that if North-South research collaborations are a strategic global health funding priority, then methods and mechanisms to map existing networks and leverage the work of leading and emerging researchers and institutions are needed. Support to reform Canadian institutional policies related to inventions, patenting and technology transfer is required to transform existing insular practices and incentivize global health innovation and research partnerships.

Keywords: Health care management
Information Science
Advisor: Kohler, Jillian
On the Margins of Gentrification: The Production and Governance of Suburban 'Decline' in Toronto's Inner Suburbs

In many North American cities, the last two decades have witnessed not only the large-scale return of investment priorities to central cities, but also a rise in the suburbanization of poverty. This dissertation examines the problem of ‘suburban decline’ by investigating how it is produced, its effects on sub/urban populations, and the responses that it generates. I interrogate the processes through which relations of political-economic and cultural dominance are obscured, enacted, and reproduced through the production of sub/urban investment and decline. In doing so, I identify the ongoing colonial practices, classism, and systemic racism that are embedded into the neoliberal state and through it, the production and management of marginalized spaces and populations. I trace the mechanisms and techniques through which this power is mobilized to control populations and contain dissent. Finally, I demonstrate, through moments of social struggle, that growing unrest and changing demographics related to ‘suburban decline’ represent crises to the dominant structures of power. In this three-paper dissertation I document processes of political-economic and racialized marginalization in Scarborough, an inner suburb of Toronto. My analysis centres around three key moments of major contestation that are also central to social and political change in this area of the city: a failed mobilization to save community space that had taken root in a local retail mall; the implementation of a motel shelter system; the roll-out of the priority neighbourhood strategy for social investment and community governance. Highlighting struggles over suburban space and belonging, I trace the growth and decline of Toronto’s postwar suburbs, through the lens of Southeast Scarborough. I probe the tensions arising from suburban decline by excavating responses from the state at multiple levels, popular media, social agencies, faith groups, and residents. More broadly these struggles inform key dynamics that are central to contemporary transformations in sub/urban socio-spatial relationships: the production of racialized space; the targeting of poor communities; and devolution of governance responsibilities through third-sector organizations.

Keywords: suburb
gentrification
racialization
poverty
governance
action research
Advisor: Cowen, Deborah
Walks, Alan
Anansesem (Storytellling Nights): African Maternal Pedagogies

Resistance. Survival. Possibility. This is an arts-informed research text that reconciles the stories of African-Canadian mothers with my own story about how we un/intentionally and un/consciously serve as critical pedagogues for African-Canadian children. The narratives illuminate how we mother in the midst of marginalization and impart pedagogies that effectuate cultural, social and identity consciousness within children who will also experience social, economic and political barriers as they navigate the Canadian landscape. Through the Afro-indigenous tradition of storytelling and telling stories, I underscore the centrality of the African-Canadian mother in emboldening African children to become change agents equipped to resist the marginalizing tendencies of dominant society. Thus, the African-Canadian mother through her embodied knowledges and experiences becomes a site from which the African child reads to discover meaning. In effect then I show how the African mother’s body, to borrow from Michalko, “harbours a particular and valuable pedagogy” (2001, p. 351). In entering these stories, you the reader access our joys, sadness, strengths and weaknesses as we journey through motherhood. Our stories are the research text “complete (but open)…largely free of academic jargon and abstracted theory”. In this regard, this arts-informed dissertation “privilege[s] stories over analysis, allowing and encouraging alternative readings and multiple interpretations” (Bochner & Ellis, 2000 p. 745). In this spirit I share with you stories of lives told, and my life as I remember. Welcome.

Keywords: Maternal Theory
Indigenous Knowledges
African Centred Feminism(s)
Arts-Informed Methodology
Afrocentricity
Critical Feminist Pedagogies
Advisor: Knowles, J. Gary
Unnerving Images: Cinematic Representations of Animal Slaughter and the Ethics of Shock

This dissertation forges critical connections between the industrial logic of cutting up animals to make meat and cinematic techniques of cutting up indexical images of animals to create spectacle. I begin by identifying the cinematic attraction of violent animal death. In Chapter One, I argue that social and material conditions prevent cinema from representing real (i.e., unsimulated) human death, and the medium in turn relies on animal bodies to register visible evidence of death. I contend that this displacement does not yield the definitive knowledge of death that it promises; reviewing scenes of animal death, we acquire no real knowledge of the “fact” of death, but rather approach an understanding that we share death—finitude, vulnerability, suffering—with animals. Cinema’s ethical potential rests on its singular capacity to lay bare this shared susceptibility, and I thus shift my attention to evaluating how seminal scenes of animal slaughter and fundamental techniques of film form fulfill or fail this ethical potential. I begin my wide-ranging analysis by identifying and critiquing, in Chapter Two, the methods of exposure that currently dominate cinematic representations of slaughter. Through readings of an animal-advocacy video made by PETA, an industrial film made by the Hormel Co., a documentary about a labour dispute at a slaughter plant, and two popular animated representations of the meat industry, I demonstrate that these methods aim to maximize the visibility of slaughter, yet in doing so they mobilise conventions that disconnect slaughter from daily life and disassociate the spectator from the slaughtered animal body. I then look to representational strategies that destabilize the notion of slaughter as something apart. In Chapter Three, I question the enduring trope, inaugurated by Sergei Eisenstein’s Strike, of aligning indexical images of animal death with dramatic performances of human trauma and death; the production of this sort of dialectical conflict, I argue, elides the singularity and significance of animal life. In Chapter Four, I demonstrate, through close readings of Dziga Vertov’s Kino-Eye and Charles Burnett’s Killer of Sheep, the ethical value of non-dialectical formal strategies (namely, defamiliarization and juxtaposition) that develop connections between slaughter and daily life.

Keywords: Film
Animals
Animal Studies
Cinema
Ethics
Shock
Slaughter
Film Spectatorship
Meat
Advisor: Jagoe, Eva-Lynn
Quantifying and Enhancing the Statistical Convergence of Equilibrium and Non-equilibrium Properties in Molecular Simulations of Proteins, Peptides, and Amino Acid Side Chain Analogs Embedded in Lipid Bilayers

Atomistic molecular simulations provide high-resolution structural and dynamic characterizations of small molecules, peptides, and proteins interacting with biological membranes. Here I use new methods and massively repeated computer simulations to critically examine the statistical convergence of equilibrium and non-equilibrium properties in molecular simulations of three types of solute in hydrated phospholipid bilayers: amino acid side-chain analogs, the intrinsically disordered antimicrobial peptide indolicidin, and the bacterial magnesium channel CorA. This thesis is as much a journey to discover what one can learn from simulations by quantifying their sampling errors as it is a quest for convergence using massive computational resources and enhanced sampling techniques. I first evaluate the convergence of the standard binding free energy for the reversible bilayer insertion of amino acid side-chain analogs and indolicidin. I identify rare and abrupt transitions in bilayer structure resulting from slow reorganization of intermolecular ionic interactions, which constitute hidden sampling barriers that limit the rate of convergence of equilibrium properties and result in systematic sampling errors. Next, I introduce three new generalized ensemble sampling algorithms and show that they dramatically enhance the efficiency of quantifying free energy profiles for solute insertion across a lipid bilayer. I employ one of these methods with a novel analysis tool to accurately predict the amount of additional simulation time required to attain converged estimates of equilibrium properties – something that has never before been accomplished. Finally, I examine the functional hydration of a hydrophobic gate by comparing hundreds of simulations in which the regulatory sites of the CorA magnesium channel are either fully occupied or empty. In the absence of regulatory ions, water penetrates more readily into a 1.5-nm-long channel constriction that is dehydrated in all available crystal structures. These wetting transitions involve more water, and the resulting hydration is more stable, when regulatory ions are absent. Furthermore, this hydration reduces the free energy barrier to the conduction of magnesium. While many of the ensemble-averaged values presented in this thesis have converged, intra-ensemble comparisons indicate incomplete convergence of the constituent simulations. Because my microsecond-scale constituent simulations are long by contemporary standards, I conclude that the difficulty of attaining convergence for bilayer-embedded solutes is drastically underestimated in the literature.

Keywords: computer simulation
molecular dynamics
protein
membrane
lipid bilayer
enhanced sampling
Advisor: Pomès, Régis
Prospects of Statecraft: Diplomacy, Territoriality, and the Vision of French Nationhood in Rome, 1660-1700

In this dissertation I examine spaces of French national interest in Rome, proposing that France made a unique claim to the city with a distinct urban impact. Beginning with the onset of Louis XIV’s personal rule in 1661 and his death in 1715, I explore the ways in which France shaped the urban, social, and political fabric of Rome through a variety of media including architectural projects, urban claims, ceremonial displays, and city views. These expressions were not simply representations, but were visible and material manifestations of France’s extraterritorial presence in the city. This history contributes a new and necessary dimension to the predominantly juridical history of early modern diplomacy and reevaluates a historiographical truism that the popes “authored” Rome. This project centers on two key claims in Rome: the urban precinct surrounding the Palazzo Farnese (residence of the French ambassador) and the Pincian Hill, located below the French controlled church and monastery of SS. Trinità dei Monti, the proposed site of what came to be called the Spanish Steps. The legacy of France has been well documented in the scholarship on these sites but their histories have often been considered separately. I argue that the development of the diplomatic precinct and the struggle for control over the Pincio stemmed from a shared objective: the exercise of French authority as an extraterritorial enterprise; a process that “revisioned” Rome itself as an extension of French territory. Chapters 1 and 2 focus on an urban discourse associated with embassy in diplomatic theory and practice. Chapters 3 and 4 explore manifestations of French territoriality on the Pincio, including urban strategies employed by the Minims to claim control over the hillside, and a monumental print by royal engraver Israël Silvestre depicting Rome through French eyes. I conclude by discussing the refectory program at Trinità dei Monti, a work that I argue encapsulates the territorializing efforts of the French in Rome. By addressing the common threads between these distinct historiographies and integrating new findings based on my archival research, this dissertation contributes to the understanding of French strategies of nation-building in early modern Rome.

Keywords: Baroque
Rome
Louis XIV
France
Architecture and Urban History
Diplomacy
Print Culture
Andrea Pozzo
Israel Silvestre
Early Modern
Nationhood
Extraterritoriality
Embassy
Trinita dei Monti
Minims
Ambassador
Advisor: Levy, Evonne