VictorJuiz/thesis huggingface dataset:
Investigation of Synthetic Jet Flow Control Parameters for the Mitigation of Laminar Boundary Layer Separation

An experimental study was performed to elucidate the effects of forcing parameters on the mitigation of boundary layer separation on an airfoil at low Reynolds number. Post- stall flow at a Reynolds number of 100,000 and angle-of-attack 12 degrees on a NACA 0025 airfoil served as the baseline for control with a synthetic jet actuator. This baseline flow is characterized by two dominant instabilities: the large scale vortex shedding in the wake of the airfoil, and the roll-up of vortices in the separated shear layer. The forcing parameters that were investigated were the blowing ratio, excitation frequency, and the chordwise forcing location. The results concerning the effects on aerodynamic performance showed that for both drag reduction and lift increase, the benefits of control saturated with increasing blow- ing ratio. Initial improvements to lift and drag were due to the formation of a laminar separation bubble, followed by fully attached flow once a threshold blowing ratio was met. Positioning the slot at the most upstream location resulted in the lowest thresh- old blowing ratio and produced the largest lift-to-drag ratios. A monotonic increase in threshold blowing ratio and decrease in lift-to-drag was observed as the slot location moved downstream. It was also found that while forcing at a frequency corresponding to the wake instability led to maximum lift increase, forcing in the range of the separated shear layer instability led to maximum drag reduction. High-frequency forcing, where the time scales of control are much smaller than those of the flow, was found to be least effective for improving performance. The controlled flow dynamics revealed the presence of large vortices passing over the suction surface and highly unsteady flow when forcing at the wake instability frequency, whereas forcing in the range of the shear layer instability led to the production of a larger number of much smaller vortices. The latter case led to a thinner boundary layer in the time-averaged sense. Extraction of coherent and turbulent velocity fluctuations showed that the controlled flow was steady in time with high-frequency forcing.

Advisor: Lavoie, Philippe
Sullivan, Pierre E
Identification and Characterization of Novel Upstream Regulators of the Hippo Signalling Pathway

The evolutionarily conserved Hippo signalling pathway is a major determinant of growth control and organ size. The co-transcription factors YAP/TAZ are downstream effectors of the Hippo pathway that regulate vital processes like cell proliferation, cell migration, apoptosis, stem cell self-renewal and differentiation. YAP/TAZ are regulated by the core Ser/Thr kinases of the Hippo pathway MST1/2 and LATS1/2. Upon activation, MST1/2 in association with the adaptor protein SAV, phosphorylate and activate the downstream kinases LATS1/2. In turn, activated LATS1/2 in association with the adaptor protein MOB, phosphorylate YAP/TAZ leading to cytoplasmic accumulation, degradation and transcriptional inactivation of YAP/TAZ. The Hippo pathway can be regulated by various intrinsic and extrinsic stimuli such as mechanotransduction, actin cytoskeleton dynamics, cell-cell contact and cell polarity, G-protein coupled receptor signalling and metabolic pathways. However, the mechanistic details and molecular mediators that connect the upstream stimuli to the core of the pathway are not fully understood. With the aim of identifying novel upstream regulators of the Hippo pathway we undertook a high-throughput LUMIER-based protein interaction screen complemented with a TEAD-luciferase reporter screen that led to the identification of βPIX and MARKs as positive and negative regulators of the Hippo pathway, respectively. Mechanistically, βPIX mediates the interaction between YAP/TAZ and the Hippo core kinase LATS to promote YAP/TAZ phosphorylation and transcriptional inhibition. Conversely, MARK4 enhances YAP/TAZ transcriptional activity in a kinase-dependent manner by phosphorylating MST and SAV, and disrupting complex formation with the downstream LATS kinase. Furthermore, abrogation of MARK4 or βPIX overexpression in breast cancer cells attenuates tumorigenic features such as proliferation and migration by activating the Hippo kinase cascade. Finally, βPIX and MARK binding partners GIT1 and DLG5 are respectively characterized as positive and negative regulators of YAP/TAZ transcriptional activity.

Keywords: Cancer Biology
Hippo Pathway
Signal Transduction
YAP/TAZ
Advisor: Attisano, Liliana
Administrative Justice: Guiding Caseworker Discretion

This thesis demonstrates how flexibility and constraint arise in the context of Ontario Works, a welfare program with a reputation as both rule-bound and discretion-rich. Based on a qualitative socio-legal study of front-line decision-making in five local offices across two southern Ontario municipalities, this dissertation explores how discretion functions at and behind the front-lines of the Ontario Works program. Drawing on legal and socio-legal literature, it demonstrates how in a formal sense discretion becomes explicitly and tacitly incorporated within discrete legislative provisions and, as these rules cross-reference one another, nested throughout an entire legal framework. Further, it shows how front-line workers animate these text-based grants as they perform operational discretion in their routine interactions with benefits recipients, such that it becomes virtually impossible to distinguish discretion from non-discretion at any specific decision-making moment. This thesis then shifts gears to argue that operational discretion is nonetheless guided by two factors: a shared methodology of normative balancing according to which workers reconcile competing legal and managerial norms; and a systematic diffusion of decision-making responsibilities among human and non-human actors such that decisions are produced and influenced by an aggregation of decision-makers. In doing so, it demonstrates how the effects of ideological divergence among caseworkers, on a spectrum ranging from pro-client social workers to black-and-white efficiency engineers, is minimized by the convergence prompted by normative balancing and aggregated decision-making. This thesis then reflects on how new regulatory technologies may subtly shift front-line workersâ perception of their roles as legal decision-makers, from caseworkers who perform discretion in relation to an audience of coworkers with whom they can reason to individuals who must covertly â manipulateâ the legal-technical system with which they are now governed.

Keywords: discretion
new public management
regulatory technology
street-level bureaucrats
welfare
Advisor: Reaume, Denise
Three Essays in Industrial Organization

This thesis contains three papers that empirically examine firm competition and market regulation in oligopoly settings. Chapter 1 looks at the effects of consumer search costs on entry, product design, and quality in online markets. Using data from the Google Play mobile app store, I take advantage of a natural experiment that reduced search costs for one product type (game apps) in early 2014. DiD estimates show that entry increased by 33$\%$ relative to the control group (non-games), primarily by ``niche" products. These estimates also show that the quality of new entrants fell. To separate out the different welfare effects of this change, I develop and estimate a structural model of demand and supply. I show that there are large welfare gains from reduced search costs, smaller gains from increased product variety, and very small losses from lower product quality. Chapter 2 (joint with Scott Orr and Jean-William P. Lalibert\'e) examines merger analysis in markets where products are demand complements. Standard discrete choice models assume that product varieties are substitutes. These models will overstate consumer harm in merger cases with complements. We use consumer level data to look at products with natural demand complementarity - chips and soda. We estimate a discrete choice model that allows for demand complementarity and simulate a merger between PepsiCo/Frito-Lay and Dr. Pepper. Our model predicts that pop prices either increase or fall in this merger. By contrast, the standard model predicts that pop prices would always increase. Chapter 3 (joint with Victor Aguirregabiria and Junichi Suzuki) studies the impact of competition in the Ontario wine retail market. The wine retail market of Ontario is characterized by the coexistence of the government-owned LCBO and two private companies. These private firms are restricted in their locations and their product variety. We estimate a spatial demand model using a unique dataset from the LCBO. We then simulate the effects of deregulation proposals (relative to a LCBO monopoly). We show that entry of additional competitors increases consumer welfare and consumption. Expanding the product range of existing competitors also increases consumer welfare, but keeps consumption stable.

Keywords: Competition
Industrial Organization
Regulation
Advisor: Aguirregabiria, Victor
Copyright and Freedom of Expression: A Rawlsian Charter Analysis

This thesis considers the relationship between copyright and freedom of expression in the Canadian legal context. It is argued that the existing Copyright Act constitutes an unjustified limitation of the Charter right to freedom of expression. In addition to analyzing and applying the relevant case law, the thesis suggests an alternative conceptual framework for assessing Charter rights violations. The proposed framework is derived from John Rawls's political philosophy, and requires judges to reason as though behind a Rawlsian veil of ignorance. It is argued that the Copyright Act limits freedom of expression, since most copyright infringing acts are attempts to convey meaning. It is further argued that the limitation cannot be justified under section 1 of the Charter, as the Act would not be selected over the available alternatives while under the veil of ignorance.

Keywords: Canada
Charter
Copyright
Expression
Proportionality
Rawls
Advisor: Drassinower, Abraham
Filling in the gaps of the spectrum-wide characterization of hydrophobins: An interface-active protein family with industrial potential

Hydrophobins are secreted non-catalytic fungal proteins that act at interfaces whose functions range from self-assembling to form a fungal â raincoatâ on the fruiting body, to recruiting enzyme activities to surfaces. Traditionally subdivided into two classes (I and II) based on primary sequence and observed solution characteristics, the underlying thesis of this work is that classification of type I hydrophobins can be further refined. As such, the analysis of the predicted primary sequences of hydrophobins originating from the genomes of over 200 fungal species was conducted by sequence-alignment principal component analysis (SA-PCA) revealing a high-identity class I Basidiomycota subdivision. To experimentally validate this subdivision, the structure of one of its members, the predicted Schizophyllum commune hydrophobin SC16 (hyd1), was solved by solution-NMR. While sharing the core hydrophobin structure, structural elements believed to be necessary for class I behaviour were absent. However, the protein was an active class I hydrophobin as demonstrated by specific binding to the amyloid-detecting dye Thioflavin T and rodlet formation at the air-water interface visualized by atomic force microscopy (AFM). Together, these results reveal a structural basis for the class IB subdivision. Next, methods to further characterize the spectrum of hydrophobin sequences were explored. Pichia pastoris was found to be an effective host for the soluble recombinant expression of the three predicted hydrophobins of the Ascomycota entomopathogen Cordyceps militaris genome. Of these solubly expressed proteins, the preliminary visualization of class I type rodlets by AFM of one of the three (CMil3) is discussed. In the final chapter the matrix-free chromatographic technique of flow field-flow fractionation was harnessed to study the oligomeric solution-state of hydrophobins. This dissertation concludes with next steps in applying the framework used for the sequence analyses as a means of mapping and testing the bounds of the unique properties exhibited by this protein family.

Keywords: Amyloid
Hydrophobin
SC3
Self-assembling
Advisor: Master, Emma R
Early Mother-Child Relationships Influence Weight Regulation in Pre-School Children

While there has been significant historical interest in how the maternal- infant dyadic relationship shapes eating behaviour and obesity risk, only recently have systematic, longitudinal studies of this association been reported. The current thesis both replicates and extends this recent work using three studies based on the MAVAN developmental cohort: Study 1 examined the association between 6 month maternal sensitivity scores and BMI z-scores measured at 48 months of age. As hypothesized, low maternal sensitivity early in life was associated with higher BMI z-scores and an increased likelihood of being at risk for overweight, overweight or obese in girls but not boys. These findings replicate recent work by Anderson SE et al (2012); we provide the first evidence of a possible sex difference in this relationship, and extend prior findings to the pre-school years. Study 2 examined whether emotional overeating, food responsiveness, and/or enjoyment of food at 48 months as assessed using the Childrenâ s Eating Behaviour Questionnaire (CEBQ) mediated the relationship between 6 month maternal sensitivity scores and BMI z-scores at 48 months. Results indicated that only emotional overeating was a significant mediator of this association for girls but not for boys. Further analysis revealed that in girls only, low maternal sensitivity was associated with an increased likelihood of being at risk for overweight in connection with emotional overeating. Study 3 examined whether exclusive breastfeeding at 6 months moderates the relationship between 6 month maternal sensitivity scores and BMI z-scores measured at 48 months of age, and whether the sex of the child might further moderate this association. The results supported the general working hypothesis that exclusive breastfeeding at age 6 months moderates the association between maternal sensitivity at 6 months and child BMI z-scores at 48 months. Overall these results demonstrated another highly novel developmental trajectory relevant to early weight regulation, and offered new support for current WHO recommendations for exclusive breastfeeding through 6 months of age. Taken together, these three studies have demonstrated that early maternal sensitivity provides a significant influence on child weight regulation/ BMI in the pre-school years, moderated by sex and exclusive breastfeeding and mediated by emotional overeating.

Keywords: BMI
Breastfeeding
Emotional eating
Maternal Sensitivity
Sex differences
Advisor: Levitan, Robert D
Preparation, Surface Modification and Application of Lanthanide Nanoparticles as Elemental Tags in Mass Cytometric Bioassays

This thesis describes the preparation, surface modification and application of lanthanide nanoparticles (Ln NPs) as elemental tags in bioassays by mass cytometry. The most common elemental tags in mass cytometry are lanthanide metals. Previous studies established polymer-based lanthanide tags for mass cytometric bioassays. My studies focused on developing a new generation of elemental tags based on Ln NPs for bioassays by mass cytometry. The first part of my thesis describes a ligand exchange strategy for making Ln NPs that are colloidally stable in aqueous buffer media. This strategy yielded NaLnF4 NPs capped with PEG-PAMAM surface ligands. These PEG-PAMAM-capped NPs were colloidally stable in water but lacked long-term colloidal stability in PBS. This made the PEG-PAMAM-capped NPs incompatible with cell assays by mass cytometry. The second part describes the preparation of small LnF3 NPs as internal labels for Ln-containing polymer microspheres. This work was done by collaboration with Dr. Jianbo Tan. He prepared PMMA microspheres labeled with those small LnF3 NPs. We then developed a streptavidin-biotin binding assay using those LnF3-labeled microspheres as a proof-of-concept bead-based assay by mass cytometry. The third part describes a sandwich-type bead-based immunoassay by mass cytometry. I prepared NaYF4@SiO2 NPs as reporter tags for this bead-based immunoassay. By using the LnF3-labeled PMMA microspheres as bead supports, I established a bead-based immunoassay that specifically targets human IgG and tested the specificity of this assay by TEM. The fourth part discusses making a NP-based elemental tag that can specifically target cell surface markers with minimal non-specific cell binding. I synthesized PEGylated NaHoF4@SiO2 NPs and attached antibodies onto the PEG corona of the NPs. These NP-antibody conjugates showed excellent targeting ability for CD20 antigens on Ramos cells along with a low background level of non-specific binding. Future experiments are needed to demonstrate their usage in detecting low-abundance cellular biomarkers by mass cytometry.

Keywords: cell assay
lanthanide
mass cytometry
nanoparticles
Advisor: Winnik, Mitchell A
Nitz, Mark
The Effects of Fuel Chemistry and Particle Maturity on Soot Formation

A criterion to define soot maturity, a theoretical modeling approach to simulate it, and its effects on the surface reactivity of soot primary particles in laminar premixed and diffusion flames are presented in the first two chapters. It is shown that the core-shell internal nanostructure of soot primary particles is a function of the overall soot Hydrogen to Carbon (H/C) ratio and can be used to distinguish nascent from mature soot primary particles. The importance of considering dehydrogenation to predict the H/C ratio and maturity of soot is illustrated. It is shown that the decay of soot surface reactivity with maturity, i.e. soot aging, is a strong function of the internal nanostructure of soot primary particles. The necessity of simulating soot maturity for comparison with experimental measurements is discussed. Structural effects of biodiesel in terms of unsaturation, i.e. C-C double bond, its position, and the presence of the ester moiety on soot formation are investigated in chapters four and five. It is shown that unsaturation increases soot formation by higher production of soot chemical growth species while more centrally located double bond increases soot formation by producing more soot nucleating species. However, the ester moiety decreases soot formation by reducing the concentration of soot chemical growth species such as acetylene. Several experimental techniques for measuring flame temperature, soot volume fraction, primary particle diameter, and aggregate structure are compared to each other in the last chapter. It is shown that Time Resolved Laser Induced Incandescence is the most reliable method to measure the volume fraction and the primary particle diameter of mature soot particles. The sensitivity of thermocouple measurements to radiation correction is analyzed and it is shown that for accurate temperature measurement with a thermocouple, it is essential to use a locally measured variable emissivity to estimate radiation cooling effects.

Keywords: Biodiesel
Chemical Mechanism
Combustion
Core Shell nanostructure
Laser Diagnostics
Soot
Advisor: Thomson, Murray J
Effective Models for Optical Properties: A Study on 1D, 2D, and 3D Materials

In this thesis I employ effective Hamiltonian models to study the electronic structure of materials. With these models I study charge- and spin-injection induced by optical absorption processes, and current-injection induced by quantum interference processes between different orders of absorption. I study the optical response of narrow stripes (''nanoribbons'') of monolayer graphene, monolayers of tin atoms (''stanene''), and alloys of AlGaAs. First I focus on graphene nanoribbons with zigzag shapes along their lengths, along which strongly localized (''edge'') states exist at the Fermi level of undoped samples. I present results for different chemical potentials, showing that edge states are responsible for the main contribution to the optical response at low photon energies (

Keywords: 2D Materials
Alloys
Current Injection
Effective Models
Optical Coherent Control
Spin Injection
Advisor: Sipe, John E
Shallow Water Carbonate Sediments of the Galápagos Archipelago: Ecologically Sensitive Biofacies in a Transitional Oceanographic Environment

Shallow water carbonate producing organisms are directly controlled by their local oceanography. As a result, long-term environmental signals—stemming from the breakdown of calcareous organisms—can be read from time-averaged carbonate sediments. To better understand these complex biophysical interactions, it is important to study carbonate development within oceanographic transition zones and environments affected by disturbances, such as the El Niño—Southern Oscillation (ENSO). This dissertation represents the first investigation into modern shallow water, soft sediment, carbonate environments of the Galápagos Archipelago, eastern tropical Pacific (ETP). This region is notable for straddling an oceanographic transition zone from tropical oligotrophic to temperate eutrophic—caused by high nutrient and low pH upwelling—and for being directly impacted by ENSO. A top-down approach is followed, which analyzes the biogenic structure of Galápagos sediments and their connection to local and regional oceanography and climate, and then explores how these findings relate to benthic foraminifera—sensitive environmental indicators contained within the sediments. Sediment point counting and statistical models revealed that while these carbonate environments span a biogenic and oceanographic transition comparable to similar settings in the ETP, the proximity of the Galápagos to the ENSO region directly influences its sedimentary structure and distribution. Point counting also revealed a near-absence of benthic foraminifera, which is unusual for ETP, and tropical shallow water carbonates in general. Statistically comparing foraminiferal species composition and diversity to dominant oceanographic parameters revealed the low abundances and distribution of these testate (shelled) single-celled protists to be negatively influenced by the combination of repeated Holocene ENSO events, and the effects of protracted exposure to high nutrient and low pH waters of the southern archipelago. Ultimately, the results of this study may serve as a template for investigating the interaction of carbonates and oceanography within similar atypical tropical assemblages in the fossil record.

Keywords: Benthic Foraminifera
Carbonates
El Niño Southern Oscillation
Galápagos
Ocean Acidification
Sediments
Advisor: Halfar, Jochen