VictorJuiz/thesis huggingface dataset:
Bayesian Computations via MCMC, with applications to Big Data and Spatial Data
Keywords: Bayesian Statistics
Geostatistics
Machine Learning
Markov Chain Monte Carlo (MCMC)

Markov Chain Monte Carlo (MCMC) methods are fundamental tools for sampling highly complex distributions. They are crucial to Bayesian inference as posterior distributions are generally analytically intractable. In this thesis, we tackle two Bayesian inference problems via MCMC methods, that will lie on both methodology and application aspects. The first part of this thesis tackles the computational challenges of Bayesian inference from big data. We develop a new communication-free parallel method, the "Likelihood Inflating Sampling Algorithm (LISA)", that significantly reduces computational costs by randomly splitting the dataset into smaller subsets and running MCMC methods independently in parallel on each subset using different processors. Each processor will be used to run an MCMC chain that samples sub-posterior distributions which are defined using an "inflated" likelihood function. We then discuss on the approaches to combine all sub-samples from all processors to build a highly accurate posterior distribution that is consistent with the full posterior distribution. More importantly, we learn a strategy in combining LISA's draws to study the full posterior of the more complex Bayesian Additive Regression Trees (BART) model, which is highly important in non-parametric regression. We also successfully examine the consistency in performance of LISA on BART with new efficient Metropolis-Hastings proposals introduced by Pratola (2016). The second part of this thesis is focused on the applied aspect of performing Bayesian inference with MCMC methods. We study a Bayesian Geostatistical model to analyze spatial data from the Timiskaming Abitibi River forests in Ontario Canada, provided by the First Resource Management Group Inc.. We implement an MCMC algorithm to perform Bayesian inference on predicting the proportion of hardwood trees from elevation and vegetation index. Spatial predictions are made for new sites in the forests and results are compared with a Logistic Regression model without a spatial effect. We study the trend of accuracy in predictions when fitting fewer data to the model, and present useful insights on the trade-off between performance and the costly need for collecting ground truth data. We further discuss a stratified sampling approach in choosing the subsets of data that allows for potential better predictions.
On mod p local-global compatibility for unramified GL_3
Keywords: Automorphic representations
Galois representations
Langlands program
Mod p Langlands program

Let F/F+ be a CM number field and w|p a place of F lying over a place of F+ that splits in F. If r¯:GF → GLn( F¯p) is a global Galois representation automorphic with respect to a definite unitary group over F + then there is a naturally associated GLn( Fw)-representation H0( r¯) over F¯p constructed using mod p automorphic forms, and it is hoped that H0(r¯) will correspond to r¯|GFw under a conjectural mod p local Langlands correspondence. The goal of the thesis is to study how to recover the data of r¯|GFw from H0(r¯) in certain cases. Assume that Fw is unramified and n=3. Under certain technical hypotheses on r¯, we give an explicit recipe to find all the data of r¯| GFw inside the GL3(Fw)-action on H0(r¯) when r¯|GFw is maximally nonsplit, Fontaine-Laffaille, generic, and has a unique Serre weight. This generalizes work of Herzig, Le and Morra who found analogous results when Fw= Qp as well as work of Breuil and Diamond in the case of unramified GL2.
The Production Of Presence: How Women Of Colour Transmute Online Activities Into Offline Change
Keywords: internet
planning
race
right to the city
social media
women

This dissertation project explores the intersections of and interactions between virtual and material spaces as studied through the online activities of women of colour social justice activists in Toronto. Internet technologies and services have reshaped everyday urban life, and the growing availability of devices and access to online spaces and networks are changing how we engage with the city. In this dissertation, I examine how the internet facilitates access to the right to the city for racialized and gendered individuals who may have been excluded from city-building processes. Using a mixed methods approach, I combine participant interviews with digital archival research; I also use mainstream media coverage as a secondary data source to provide verification and reinforce my findings. Through what I term “the production of presence,” I investigate the relationships between online user-generated content and its effects on offline lives, spaces, and processes. First, I describe the how women of colour social justice activists in Toronto use their online activities to access their right to the city, extending this to include the right to represent the city. I look at the characteristics of virtual spaces that uniquely enable and facilitate different ways of being in urban spaces. Second, I apply an object-oriented framework to user-generated content to examine the how this data has the agency to both produce presence that extends beyond the tokenism of visibility politics, and to organise readers into audience, publics, or communities. Examining user-generated content as object reveals the agency of data and raises questions about the ethics of accessing and using user-generated content in professional practice, which I explore in further depth in the third paper of this dissertation. In this final paper, I look at planning and journalism as two professions involved in shaping and representing the city, and I examine how the online personal archives of women of colour social justice activists can be accessed to inform reporting on and designing the city.
Investigation of the Thermodynamics of Halogen-Hydrogen Bonding Receptors and Organoboron–Diol Interactions by Experimental and Computational Methods
Keywords: Binding
Computation
Halogen Bonding
Hydrogen Bonding
Thermodynamics

This thesis focuses on the solution-phase measurement and computational modelling of noncovalent interactions; specifically, complexes formed of halogen-bond donor, hydrogen-bond donor and organoboron compounds with various substrates are investigated. Chapter 1 introduces halogen bonding and provides a review of the solution-phase literature, with a focus on the thermodynamics of the interaction and the use of halogen bonding in anion sensing and catalytic applications. Chapter 2 describes correlations between experimental, solution-phase thermodynamic data and calculated, gas-phase energies of interaction for halogen bonding complexes formed of a diverse set of organic and inorganic iodine donors with Lewis bases, with energies of interaction spanning 7 kcal/mol. Of 23 quantum mechanical modelling methods examined, the B97-1, B97-2 and B98 DFT functionals provide excellent correlations: a feat considering the varying nature of the complexes studied. These results are contrasted with those obtained for a set of hydrogen bonding data, for which different DFT methods (M06-2X, M05-2X) provided the best results. Chapter 3 describes the synthesis and binding traits of anion receptors containing halogen- and hydrogen-bond donor moieties. Neutral receptors composed of urea and iodoperfluoroarene groups bind halides selectively over oxo-anions when compared with receptors lacking halogen-bond donors. Charged halogen-bonding receptors loosely based on imidazolium structures and designed for two-point binding were examined. The receptors are very sensitive to basic conditions and their anion binding properties do not differ significantly from control receptors lacking halogen-bond donors. In general, the anion receptor design, particularly linear halogen bonding angles between substrate and receptor, was found to be important for efficient binding as rationalized through computational modelling of the complexes. Chapter 4 examines the binding affinities of diphenylborinic acid with various diol substrates as determined by indicator-displacement assays. The results are contrasted with measurements for a boronic acid with a similar pKa. The two compounds reveal significant differences in terms of the kinetics and thermodynamics of their interactions with diols: in particular, diphenylborinic acid displays an unusually high level of discrimination for catechol over carbohydrates. Attempts to rationalize the selectivity are made by way of computational modelling.
Maternal and Child Health and Nutrition in Afghanistan
Keywords: Afghanistan
Child
Conflict
Health
Maternal
Nutrition

Afghanistan is an impoverished conflict-prone nation with some of the worst documented maternal and child health and survival indicators worldwide. Entering a period of relative stability after the 2001 US-led upheaval of Taliban governance, Afghanistan had, for the first time in decades, an opportunity for redevelopment and growth. Government, along with development partners, funders, civil society, NGOs and the global community, came together to rapidly expand basic infrastructure, strengthen the health care system, and to scale-up health services throughout the overwhelmingly rural population. This dissertation’s aim was to systematically document progress and determinants of maternal and child health intervention utilization and nutrition during the 2001 to 2014 time period, and to identify remaining geographical and socioeconomic inequalities. First, I examine determinants of improvements in two critical markers of maternal and newborn health and survival (skilled birth attendance and institutional deliveries) from 2003 to 2011 using nationally-representative survey data. Next, a thorough assessment of the socioeconomic and regional inequalities in essential reproductive, maternal, newborn and child health (RMNCH) interventions in Afghanistan is presented. Finally, I conduct modeling exercises of the basic, underlying and immediate determinants of undernutrition among children (
Root Ecology for Sustainable Agroecosystems: Intraspecific Variation in a Pan-Tropical Tree Crop
Keywords: agroecology
agroforestry
functional traits
Ghana
soil
Theobroma cacao

Agroecosystems that rely on higher levels of biodiversity and fewer inputs to sustain both crop production and ecosystem function require a dramatic shift away from a one-size-fits-all approach to management. Notably, this means that phenotypic expression of plants on farms cannot be assumed constant, as biotic and abiotic conditions in low-input, biodiverse agroecosystems are complex. To accurately assess and predict plant and ecosystem function in these agroecosystems, we require a more robust understanding of the drivers and consequences of intraspecific variation in plants. This includes root systems, which are arguably understudied but have a critical role in resource acquisition and use. To this end, I carried out research on the root systems of an economically important and widely cultivated tree crop,
Development of Lightweight Organic Aerogels for Thermal Insulation Applications
Keywords: Aerogel
Foaming
Heat transfer
Nanomaterials
Nanotechnology
Polymer

Organic aerogels provide the solutions for many sectors, due to their extremely unique feature and their unique structure that are spread-out at different length scale. Organic aerogels are considered the next generation materials due to their high tunability and adaptability by the tailoring of their final properties. Tailoring of organic aerogels properties is the theme of many nanocellular and low-density materials research, however, such process experiences many challenges. The main two challenges of tailoring such materials are: (I) the synthesis of monolithic aerogels with strong mechanical properties while preserving their unique features, and (II) the deep understanding of the origin of such features and correlating each feature to a structural parameter. This work addressed both these challenges to have a deep understanding of organic aerogels and to integrate them into many sectors. The synthesis process focused mostly on pure organic aerogels without any composites, at first, to correlate the processing conditions to the micromorphological parameters. The micromorphological parameters were further studied to quantify each parameter that controlled the assembly of the aerogel three-dimensional network. Then, each parameter was correlated to the structural final property to better understand the uniqueness of the organic aerogels features. With the correlation build-up between the processing-structure-properties of organic aerogels, a heat transfer model was conducted on the structure. In such model, each heat transfer mode was identified and linked to a structural parameter which controlled it. The organic aerogels were further modified to enhance their mechanical properties by the addition of nanofibers and nanosheets into the structure. The composites assembled homogeneously into the organic aerogel structure to create a uniform network of the aerogels particles along with the composites. With a such network, the mechanical properties of the aerogels increased dramatically while preserving their unique features. Finally, the operational limitations that are inherent to the organic aerogel were surmounted thru the modification of the aerogels chemical composition. The new aerogels could operate at high temperature and have a high fire retardancy ability. Furthermore, such aerogels could resist moisture, which makes these materials ideal to be used in high temperature and humid environments.
GENETIC VARIATION IN THE timeless GENE MEDIATES METABOLIC STATES OF Drosophila melanogaster IN RESPONSE TO PHOTOPERIOD
Keywords: circadian clock
genetic variation
metabolism
Photoperiod
timeless gene

Genetic variations in the circadian clock may regulate photoperiod-induced anticipatory metabolic adjustments that allow organisms to meet the changes in energetic demands associated with different seasons. Both mammalian and Drosophila studies have shown that perturbed circadian feeding rhythm and aberrant light cycles result in disruptions in fat and glucose metabolism. In this thesis, Drosophila melanogaster was used to investigate the effect of genetic variation in the circadian system on the regulation of feeding and metabolic responses to photoperiod. Here, we analyzed the metabolic responses of two naturally occurring variants of the Drosophila timeless (tim) gene to changes in photoperiod. We found that ls-tim variants, which are known to have attenuated light-sensitivity and are more responsive to diapause, display metabolic traits that are associated with enhanced energy stores and reduced energy expenditure in response to a short-day. Analysis of tim RNA levels in the fat body revealed that it is elevated in ls-tim in response to a short-day suggesting that altered regulation of the clock in the fat body of ls-tim may mediate these enhanced metabolic adjustments to short-day. To examine the role of the foraging gene as a mediator of metabolic outputs regulated by the clock, we analyzed the circadian feeding pattern of foraging variants. Genetic variation in the foraging gene, which encodes cGMP dependent protein kinase (PKG), is known to regulate feeding behavior and energy homeostasis in Drosophila. Our results suggest that foraging regulates the frequency and daily distribution of meals. These findings demonstrate that genetic variations in the circadian system are important in mediating photoperiodic responses to feeding and metabolic state. Characterization of a role of genetic variations in clock genes on the regulation of feeding and metabolism by aberrant light cycles is important in identifying candidate pathways involved in metabolic perturbations associated with shift-work and Seasonal Affective Disorder.
The Parent-Child Relationship as a Paradigm for Teaching and Learning in Rosenzweig and Levinas
Keywords: Child
Education
Judaism
Levinas
Parent
Rosenzweig

This impetus for this work is to gain philosophical and theological insights that could inform theories and practices of Jewish education. Analysis focuses primarily on the work Franz Rosenzweig and Emmanuel Levinas, two modern Jewish thinkers whose works suggest an awareness of the intimate relationship between Jewish Thought and the pragmatics of teaching and learning. The primary methodology of this work is an inter-textual and hermeneutical reading of key philosophical, theological, and pedagogical works of Rosenzweig and Levinas. The method reveals correlations between their broader philosophical concepts and their views concerning Jewish education, and leverages each as an hermeneutical interlocutor of the other to clarify and generate concepts concerning Jewish teaching and learning. The hermeneutical analysis undertaken in this work reveals a persistent presence in Rosenzweig's and Levinas's works of dimensions of the parent-child relationship as philosophical constructs underpinning Jewish notions of metaphysics and epistemology. These dimensions include: an ontology rooted in birth; an epistemology grounded in relations of responsibility; an ethics founded on the reproduction of love in the other. This work explores how these, and other dimensions of the parent-child relationship expressed by Rosenzweig and Levinas, correlate with their notions of teaching and learning and how these correlations can inform theories and practices of teaching and learning for Jewish education, and teaching and learning in general. Reading the works of Rosenzweig and Levinas through the lens of the parent-child relationship and teaching and learning also provides new insights into their over-all theological and philosophical projects.
Plurilingual or Monolingual? A Mixed Methods Study Investigating Plurilingual Instruction in an EAP Program at a Canadian University
Keywords: Canadian university
EAP
ELT
mixed methods
plurilingual instruction
plurilingualism

Traditionally, English Language Teaching (ELT) has relied on the use of English only, with little attention to students’ knowledge of other languages and cultures as resources for language learning (Cook, 1999; Cummins, 2007; 2017). Recently, however, calls have been made for a multilingual/plurilingual shift in Applied Linguistics with literature pointing to issues that need further exploration, such as the disconnect between the theory of plurilingualism and its practice, the prevalence of monolingual practices in ELT, and teachers’ lack of preparation in plurilingual pedagogy. This mixed methods study addresses these challenges by investigating how plurilingual instruction differs from monolingual instruction in an English for Academic Purposes (EAP) program in a university in Canada. It also aims to investigate affordances and challenges of plurilingual instruction from both students’ and instructors’ viewpoints as well as the effects of plurilingual instruction on EAP students’ perceived plurilingual and pluricultural competence (PPC). Data were collected from adult students (N = 129) in treatment (plurilingual instruction) and comparison (monolingual instruction) groups, and their instructors (N = 7). Demographic questionnaires, the plurilingual and pluricultural competence (PPC) scale, student diaries, classroom observations, and focus groups were used to gather data from students, and semi-structured interviews gathered instructors’ perceptions of both instructional approaches. Following a concurrent embedded mixed methods design (Creswell Plano Clark, 2011), results show several affordances of plurilingual instruction such as enhanced plurilingual and pluricultural awareness, cognitive development, empathy, and relatability, among other factors. Furthermore, results indicate that PPC levels from students in the treatment group increased significantly over time (M = .19, SD = .27) relative to students in the comparison group (M = .07, SD = .26), t(127) = 2.44, p = .016. While none of the instructors had received previous training in plurilingual pedagogy, they unanimously reported preference for plurilingual instruction. This study is significant as it provides evidence from multiple data sources that plurilingual instruction is more effective than monolingual instruction. It also bridges the gap between the theory and practice of plurilingualism, contributing with practical pedagogical directions in ELT.
Quantum Dots in Perovskites: Liquid Heteroepitaxy for Optoelectronics
Keywords: Optoelectronics
Perovskites
Quantum dots

Solution-processed semiconductors have played a key role in advancing next-generation optoelectronics. Among such materials, colloidal quantum dots are particles with nanometer dimensions that have shown excellent properties in light-emitting devices and photodetectors. Metal halide perovskites represent a complementary, recently-advanced, materials set that showcases carrier transport properties that approach those of single-crystal materials. Each branch has limitations: perovskites to date have not offered short-wavelength infrared absorption and emission; and quantum dots suffer limited transport, something that decreases the efficiency of devices. Here – by constructing using liquid processing a heteroepitaxial junction – we unite the benefits of quantum dots and perovskites in a new material. First we develop the materials chemistry to produce quantum dots in perovskites (DiP). We investigate the properties of DiP, finding that an epitaxial-quality heterointerface enables efficient transport to, and injection across, the type-I heterojunction between the perovskite matrix and the quantum dots embedded therein. We then explore three classes of devices that leverage DiP. In the first, we make the most efficient solution-processed infrared light-emitting diode, a device that has both an average external quantum efficiency of 5.2% and a record peak power conversion efficiency of 4.4%. This record PCE represents a fully 2-fold improvement relative to the best prior reports. We then develop a new class of solution-processed photodetectors--field-emission devices that leverage voltage-driven emission of photoelectrons into the high-mobility perovskite transport phase. The devices exhibit specific detectivities that exceed 1012 Jones. Finally, we show how DiP can enable advances in the mechanistic understanding of new optoelectronic materials. We report the application of DiP to characterize the diffusion length of minority carriers in single-crystal perovskites – a metric that has, until this work, been the subject of orders-of-magnitude controversies in prior works. These new insights into diffusive transport enable me to provide quantitative bounds on the ultimate potential of perovskite solar cells. Overall, this work showcases the promise of dot-in-perovskite materials that unite solution processing, infrared emission, and excellent carrier transport. It concludes with a discussion of paths forward toward further application of these exciting materials in next-generation optoelectronics.