VictorJuiz/thesis huggingface dataset:
Maternal and Perinatal Health of Refugees in Ontario: A Population-based Perspective

Refugee women and their newborns are suspected to experience greater risk of adverse maternal and perinatal health outcomes. However, little systematic refugee-specific research has been done. This dissertation poses the research question - "are refugee immigrant women and their newborns at higher risk of adverse maternal and perinatal outcomes compared to 1) non-refugee immigrant and 2) non-immigrant women?" Large population-based immigration (1985-2010) and hospitalizations databases (2002-2010) from Ontario, Canada were used (all women eligible for health insurance). The first manuscript examined severe maternal morbidity (SMM) and SMM subtypes among refugee immigrants compared to both non-refugee immigrants and non-immigrants. The rate of any SMM was elevated among refugees (n=30,420) compared to non-refugee immigrants (n=235,540) (adjusted rate ratios (ARR)=1.22, 95% confidence interval: 1.09-1.36) and non-immigrants (n=878,709) (ARR=1.34 (1.23-1.47)). HIV (SMM subtype) among refugees was 8 and 17 times that of non-refugee immigrants and non-immigrants, respectively. The SMM rate among refugees was no longer elevated when deliveries with HIV were excluded. The second manuscript examined the risk of severe neonatal morbidity (SNM) among neonates born to refugees compared to those of non-refugee immigrants and non-immigrants. SNM risk among non-sponsored refugees (i.e., asylum seekers) was also compared to that of sponsored refugees (i.e., government, privately sponsored). The risk of severe neonatal morbidity was significantly higher among newborns of refugee compared to non-refugee immigrants (ARR=1.10 (1.03-1.17)) but lower in comparison to non-immigrants (ARR=0.94 (0.89-0.99)). There was no difference by sponsorship status. The objective of the third manuscript was to determine if the relationship between refugee status and risk of preterm birth (PTB) was modified by secondary (migration to another country prior to Canada) or primary (direct to Canada) migration. A secondary objective was to examine whether this relationship varied by maternal region of birth. Secondary refugees and primary refugees experienced a significantly higher cumulative probability of PTB (22-31, 32-36, ≥37 weeks) compared to their secondary and primary non-refugee counterparts (adjusted cumulative odds ratio (ACOR) =1.59 (1.25-2.01) and ACOR=1.12 (1.02-1.23)), respectively. These associations were also significant for Asian immigrants. This dissertation makes a substantial contribution towards understanding the health and the determinants of health of refugee immigrant mothers and their infants in Canada.

Keywords: perintal epidemiology
refugee health
social disparities
Advisor: Urquia, Marcelo
Cole, Donald
The Effect of Hydrostatic Pressure on the Nematic Phases of Sr3Ru2O7

Electronic nematic phases have a special symmetry that lies between the Fermi liquid and the Wigner solid, with the symmetry controlled by electron-electron interactions. Hydrostatic pressure is a direct and effective parameter that can change the interactions between electrons and thus is a powerful tool to study nematic phases. There are two nematic phases (nematic phase 1 and 2) found in the bi-layer ruthenate Sr

Advisor: Julian, Stephen R.
Towards Solid-phase Nucleic Acid Hybridization Assays on a Paper-based Platform and Within Channel Microfluidics Using Quantum Dots as Donors in Fluorescence Resonance Energy Transfer

The work described herein has explored solid-phase transduction of nucleic acid hybridization on platforms composed of paper substrates, and also glass surfaces within glass/polydimethylsiloxane microfluidic channels. Single-stranded probe oligonucleotides were conjugated to quantum dots (QDs), and the QDs were immobilized to the solid substrates. The QDs served as donors in fluorescence resonance energy transfer (FRET). Hybridization of solution-phase targets with the probes brought acceptor dye in close proximity to the surface of immobilized QDs, triggering a FRET-sensitized emission from the acceptor dye for ratiometric transduction of nucleic acid hybridization. Chemical modifications of the paper and glass surfaces were developed to immobilize the QD-probe conjugates. Assays with both the paper and glass platforms exhibited fast hybridization kinetics with complete signal development within minutes. For the channel microfluidic experiments, the quantification of target was determined from the spatial length of the microfluidic channel that provided an optical emission indicative of the presence of hybrids. For the paper-based QD-FRET assays, quantification was based on the magnitude of donor and acceptor photoluminescence intensities. The intensity of emission from the paper-based assays was determined using an epifluorescence microscope, and also a consumer digital camera. A novel signal enhancement strategy for QD-FRET transduction was demonstrated on paper substrates. Drying compacted the paper and increased the optical cross-talk of QD-FRET probes to enhance emission intensity. Multiplexed detection of two oligonucleotide targets with excellent mismatch discrimination was demonstrated by implementation of two different QD-dye FRET pairs. Both assay platforms offered a detection limit in the femtomole range, and additional isothermal target amplification allowed target detection in the zeptomole range. The work in this thesis demonstrates that integration of the QD-FRET transduction method with microscale fluidic platforms provides for analytical figures of merit that are sufficient to warrant development of field portable and point-of-care nucleic acid diagnostic applications.

Keywords: Fluorescence resonance energy transfer
Microfluidics
Nucleic acid detection
Paper-based assays
Quantum dots
Advisor: Krull, Ulrich J.
The Colloidal Stabilization of Quantum Dots: Towards Manufacturable, Efficient Solution-Processed Solar Cells

Understanding colloidal stabilization can influence the design of optoelectronic devices and enable improvements to their performance and stability. For photovoltaics, important characteristics of the active layer material are high conductivity along with a minimum of recombination centers. In order to capitalize on the benefits of solution-processed materials, it is important to minimize the number of processing steps: ideally, to achieve a low-cost solution, materials would be deposited using a single process step compatible with roll-to-roll manufacturing. Prior to this work, the highest-performing colloidal quantum dots (CQD) solar cells have relied on several deposition steps that are repeated in a layer-by-layer (LBL) fashion. The purpose of these process steps has been to remove the long insulating ligands used in synthesis and replace them with short ligands that allow electrical conduction. The large number of steps combined, typically implemented via spin coating, leads to inefficient materials utilization and fails to show a path to a manufacturable solution. In this work, the first CQD solar cells were designed, built, and characterized combining state-of-art performance with scalable manufacture. Firstly, I report the first automated CQD synthesis to result in CQDs that form high-performance CQD solar cells. I analyze the CQD synthesis and by separating it into two phases - nucleation and growth phase - my insights are used to create higher-quality CQDs exhibiting enhanced monodispersity. I then proceed to develop a CQD ink: a CQD solution ready for direct deposition to form a semiconducting film exhibiting low trap state density. In early trials the CQD ink showed only limited power conversion efficiencies of 2%. I designed a new ink strategy, which I term cleavable hemiketal ligands. This novel two-component ligand strategy enables the combination of colloidal stabilization (via this longer two-component ligand) and cleavability (enabling excellent packing in film and, ultimately, excellent electronic properties). As capstone, I report CQD solar cells exhibiting 7.9% solar power conversion efficiencies. This is, by a wide margin, the most efficient class of CQD solar cells to be reported based on a manufacturable fabrication method. The advances in this work - from automated synthesis to synchrotron studies of CQD packing to novel cleavable ligands - pave the way for new sustainable energy harvesting strategies based on solution-processed nanomaterials.

Keywords: cleavable ligands
colloidal chemistry
hemiketal
ligand design
nanoparticles
solar cells
Advisor: Sargent, Edward H
A Mouse Model of Adynamic Bone Disease (ABD) and its Consequences on Bone Quality with Age

Adyanmic bone disease (ABD) is a bone condition that is characterized by absent or very low bone turnover, which can lead to bone fragility and increased risk for fracture. The focus of this dissertation was to develop a mouse model of ABD that directly targeted osteoblasts and osteoclasts to generate the cellular hallmark of this disease. This mouse model was then used to investigate the independent and interactive effects of age and ABD on bone quality, and possible mechanisms of age-related decline in bone formation. The Col2.3∆tk (DTK) transgenic mouse was used for all aims in this study. The DTK mouse expresses a truncated version of the HSV-tk gene (∆tk) driven under a 2.3kb fragment of the rat type I collagen α1 (Col1a1) promoter, in which concomitant treatment with ganciclovir (GCV) and pamidronate induces a loss of bone turnover. GCV depletes differentiated osteoblasts to prevent bone formation while pamidronate inhibits bone resorption by osteoclasts. This mouse model of ABD showed a profound suppression in bone formation and resorption, and it has the histological hallmarks of the human condition. Aged ABD mice revealed that bisphosphonate treatment had a protective effect on trabecular bone volume and microarchitecture. However, it did not protect against age-related deterioration of bone mechanical properties and this deterioration may be due to changes beyond the mineral phase. Lastly, GCV-induced osteoblast depletion caused bone marrow stress that aged the DTK mouse skeleton by decreasing the number and osteogenic potential of progenitor cells. Our findings suggest that bone mineral density testing and even trabecular structure may not be sufficient indices for bone health in ABD. Understanding how bone cells age and their involvement in bone homeostasis may provide novel targets and paradigms for the intervention of age-related bone loss.

Keywords: adynamic bone disease
ageing
biomechanics
bone quality
mouse model
osteogenic progenitors
Advisor: Grynpas, Marc D
Synthetic and Computational Studies of Metal-ligand Cooperation with Iron Group Complexes for Water Splitting and Ketone Hydrogenation

The paradigm of metal-ligand cooperation pervades the fields of organometallic chemistry and catalysis. In its simplest form, metal-ligand cooperation can be viewed as a strategic partnership between the metal and its surrounding ligand system to achieve new modes of chemical reactivity. Classic cases of metal-ligand cooperation involve elaborate chiral catalysts containing noble metals for enantioselective hydrogenation reactions, which are able to generate chiral compounds of great value to the pharmaceutical, agrochemical, and flavour industries. In recent years, creative design innovations have allowed chemists to create new molecules that use inexpensive iron-based catalysts for the same enantioselective transformations. Furthermore, metal-ligand cooperation has been recently employed in catalyst design pertaining to renewable/green energy applications. In particular, the activation of benign small molecules such as water, carbon dioxide, and methanol can be performed with well-defined molecular catalysts exhibiting metal-ligand cooperativity. This thesis encompasses two areas in which metal-ligand cooperation plays a vital role in the overall reactivity. First, new ruthenium complexes containing bidentate, tridentate, and tetradentate ligand systems are synthesized and investigated for applications in water splitting (2 H2O --> 2 H2 + O2). Second, computational investigations are performed to elucidate the mechanism of ketone hydrogenation using three generations of iron hydrogenation catalysts containing tetradentate PNNP ligand frameworks.

Keywords: catalysis
density functional theory
hydrogenation
synthesis
water splitting
Advisor: Morris, Robert H
The Development and Pilot Test of a Shortened Systematic Review Format For Use By Physicians

There have been great advances in refining the methods of conducting and reporting systematic reviews, however they are used infrequently by practitioners in making clinical decisions. Contextualization, format, and presentation of systematic reviews have been given little attention in the literature thus leaving a gap in what is known about these attributes. Graham's Knowledge to Action process for knowledge translation was used as a theoretical framework in the development of two shortened formats for the presentation of research evidence from systematic reviews for use in decision making by clinicians. Within the Knowledge to Action process, the tailoring of knowledge is represented as a Knowledge Funnel which includes Knowledge Synthesis and the creation of Knowledge Products and Tools. This PhD project was composed of three phases. In Phase One, a systematic review was conducted to examine the evidence on the impact of interventions for seeking, appraising, and applying evidence from systematic reviews in decision-making by clinicians. There was insufficient evidence identified from this systematic review to identify key aspects of strategies that encouraged clinicians to use systematic reviews in decision making. Similarly, no alternate formats for systematic reviews that had been rigorously developed and evaluated were identified in this systematic review. Phase Two involved a multi-component process that began with creating a prototype that employed user-centered design principles, which focus on making tools that are usable, useful, and accessible. This component was followed by a mapping exercise to identify obstacles described by clinicians in using clinical evidence in decision-making, a heuristic evaluation by an expert in human factors engineering (a usability inspection method), and a review of the clinical content in the prototypes. Iterative focus groups were then conducted with physicians who provided input on the refinement of the two prototypes. Their feedback guided changes to the format, presentation, and layout of the prototypes in order to increase uptake for end-users. Phase Three was composed of usability testing of the two prototypes by clinicians and a pilot randomized trial. Iterative usability testing offered essential insight into aspects that required modifications, and alterations were made in order to create finalized versions of the two shortened systematic review formats. A pilot randomized trial was then conducted to test methods and procedures in order to refine the processes for a larger scale randomized controlled trial, which will determine the impact of the two distinct shortened systematic review formats compared with a traditional full-length systematic review on generalist physicians' understanding of evidence and ability to apply it to a patient in a clinical scenario.

Keywords: Decision Making
Evidence Based Medicine
Primary Care Physicians
Primary Health Care
Systematic Reviews as Topic
Advisor: Straus, Sharon E.
Language Teaching as Foreign Policy: Japanese Language Teachers in Japan's International Cooperation Volunteer Program

This thesis is an ethnographic exploration of the role of Japanese as heritage language (JHL) education in the overseas communities of Japanese descent (Nikkei communities) in the contemporary diaspora strategy of the Japanese government. Through the case of a state-sponsored international volunteer program designed to serve Nikkei communities in South America (Nikkei volunteer program), this thesis illustrates how individual subjectivity formed part of a state strategy, mediated through discourses on language. This thesis discusses these processes in which the volunteers became state-sponsored JHL teachers from the perspective of governmentality with a focus on the state. The first section of the thesis illustrates historical shifts in Japan's diaspora strategies. Historically, the Nikkei population has been understood primarily as a population with Japanese ancestry, and thus Japan's support for their linguistic and cultural heritage was emphasized for the sake of community maintenance. Since the 1990s, Japan began to reframe them also as "diplomatic assets" who could "bridge" Japan and their countries of residence. South American Nikkei population's hybrid cultural identity and bilingual language skills in Portuguese or Spanish and Japanese are valued especially in Japan's development cooperation projects in countries in and outside of South America which share those languages. Situated in this context, the official promotion of JHL to the Nikkei population is seen as an effective means of maintaining a "bonding tie" between Japan and the Nikkei "assets" in South America. The second section provides a close examination of one of the key components of the above mentioned process: the training of Japanese language teaching volunteers in the Nikkei volunteer program. Using data collected from in-depth life history interviews and fieldwork, this section illustrates the volunteers' subjectivity shifts in relation to multiple discourses on language, such as English, nihongo-Japanese as a foreign language (JFL), and JHL. The discourses of English and then JFL had an impact on the volunteers' trajectories before they applied for the Nikkei volunteer program. Further transformation occurred in the volunteer training sessions, when they encountered the institutional discourse of JHL and gradually conceptualized their roles and responsibilities as teachers of Japanese as Nikkei's heritage language.

Keywords: Bilingualism
Foreign policy
Globalization
Japan
Language teaching
Neoliberalism
Advisor: Heller, Monica
Activating Aldehyde C-H Bonds: Applications to Hydroacylation and Transfer Hydroformylation

Cross-couplings that proceed via C-H bond activation streamline the synthesis of complex molecules. Rhodium complexes are promising catalysts for these reactions and they readily activate aldehyde C-H bonds to generate acyl-rhodiumIII-hydrides. Developing strategies to control the reactivity of these oxidative addition products enables developments in hydroacylation and hydroformylation. Chapter 1 describes a cooperative catalysis strategy for branched-selective hydroacylation of alkenyl alcohols with salicylaldehydes. A phosphinite ligand reversibly binds the alkenyl alcohol to promote an intermolecular coupling and override the inherent linear selectivity of hydroacylation. Chapter 2 expands branched-selective hydroacylation to non-chelating aldehydes through the advent of an electron rich rhodium catalyst with a small-bite angle diphosphine. This enabled an intermolecular olefin hydroacylation with the most broad substrate scope with respect to the aldehyde component reported to date. Mechanistic studies shed light on the rate limiting step of the reaction and the unique properties of the substrates and catalyst. Chapter 3 describes the use of bifunctional ruthenium catalysts for intramolecular ketone hydroacylation. This strategy circumvents aldehyde C-H bond activation and avoids issues of competitive aldehyde decarbonylation. γ-Butyrolactones and δ-valerolactones were generated with high enantiomeric excess by using Noyori's asymmetric transfer hydrogenation catalyst. This overall-oxidative reaction is inhibited by oxidant (acetone) and autocatalytic in a reductant (iso-propanol). Chapter 4 describes the development of a transfer hydroformylation protocol. Reactivity at room temperature was obtained with catalyst loadings as low as 0.15% by taking advantage of the unique ability of rhodium to activate typically inert C-H bonds. This method was applied to complex bioactive molecules, including macrolide antibiotics, indole alkaloids, steroids, and terpenes. Mechanistic studies revealed that a benzoate counterion acts a proton shuttle to enable transfer hydroformylation.

Advisor: Dong, Vy M
Understanding and Improving Online Social Interactions and Processes: Methods, Algorithms Applications

Over the last years, the web witnesses a prolific growth largely due to the changing trends in the use of web technology that aims to enhance interconnectivity, self-expression and information sharing. These trends have led to the development and evolution of online social systems, but also to the creation of voluminous user-generated data. Even as these new online social media change the way we communicate, the social processes occurring remain governed by long-standing principles of human behavior and social interaction. In this thesis, we focus on the algorithmic and computational issues involved in the study of online social interactions and processes, such as, behavior, influence and diffusion. We first present an analysis of user-generated content published online by non-technical users. Our analysis reveals cascading patterns of online communication and establishes evidence of a cascading effect occurring in online communities. Then, we design an analytical method for detecting social influence, the cause of cascading effects, in social systems. Our method suggests a strategy for studying the causality between changes of individual behavior and the social influence that individuals exert in their network. The ability of a network to carry on social processes is a characteristic that depends, to a great extent, on its topology. Therefore, slight modifications in the network topology, might have a dramatic effect on how efficiently social processes evolve. We approach network modification as a graph augmentation problem and come up with methods that can optimize connectivity properties of the network that can boost social processes. Finally, we present efficient methods that utilize information available in a user's social network in order to improve the quality of results they get back when they search the web. The main goal and premise is to re-order the list of retrieved results in a way that favors items that are more relevant to a user's interest towards a more personalized search experience. Overall, formal understanding of principles and models of social interaction and processes that are persistent in online social media provides an opportunity to design and develop methods, algorithms and applications that can positively impact the way we interact with, search and access information online.

Keywords: algorithms
data mining
graph mining
information network mining
knowledge discovery
online social media
Advisor: Koudas, Nick