VictorJuiz/thesis huggingface dataset:
The Abiotic Internet: Internet Mediation Through Organizational Practice at Na-Me-Res
Keywords: abiotic resources
essential services
internet as resource
social technology needs
systems theory
technology practice

This thesis examines the role of the internet in sustaining the organizational practices of Toronto’s Native Men’s Residence (Na-Me-Res) by attempting to answer the question; how essential is the internet in sustaining the delivery of Na-Me-Res’s key programs and services? The theoretical framework employed in the course of this study synthesizes the concept of indirect interactions borrowed from Ecology Studies (Moon, Moon, Keagy, 2010; Wootton, 1994) with a Systems Theory (Capra Luisi, 2014; Luhmann, 1986) approach to explicating social patterns within complex organizations. Semi-structured interviews, visual aids, and non participatory observations were employed with a view to investigating the internet’s role in supporting Na-Me-Res’s operations from the background of daily practice. The results illuminate that the internet can be framed as an abiotic resource within the organization, one that is indirectly implicated in the lives of clients and residents as a socially mediated technology resource.
Maternal High Fat Diet Alters the Transcriptional Response to Glucocorticoid and Immune Challenge in the Amygdala and Hippocampus of Adult Rat Offspring
Keywords: DNA methylation
HPA-axis
Limbic system
Maternal high-fat diet
Neuroinflammation
Stress

Maternal overnutrition during pre- and post-(peri)natal periods of development has previously been suggested to increase offspring risk for developing psychiatric disorders. The mental impacts are often accompanied by altered expressions of glucocorticoid receptors (GR), which regulate the inflammatory response to stress. In this study, rats were acutely injected with corticosterone (CORT) and/or lipopolysaccharide (LPS) in adulthood after perinatal exposure to maternal high-fat diet (HFD) to examine its effects on responding to stress. Gene transcript analyses in the amygdala and hippocampus revealed higher immunosuppressive activity and altered abundance of genes associated with anxiety- and depressive-like behavior compared to rats perinatally exposed to standard diets. These effects were sex and brain region-specific, and appeared to coincide with levels of GR. Epigenetic analyses suggest impairments in the DNA methylation machinery to be related to these diet differences. Hence, perinatal HFD incurs differential immune responses to stress in the rodent brain.
"I Got Accepted": Perceptions of Saudi Graduate Students on Factors influencing their Application Experience
Keywords: active learning
ESL
Graduate
learning types
Saudi students
university admission

This qualitative study aims at examining a number of challenges faced by Saudi students in the process of learning English while studying in an anglophone country. Through the lens of gatekeeping scholarship, progressive educational theory and formal, non-formal and informal learning modalities, certain factors such as the students’ linguistic background and their current experience were explored in an effort to shed light on these challenges. This study sought to uncover lesser known factors which come into play when predicting the success of Saudi students who study overseas. I examined students’ perceptions about their English learning experience in Saudi Arabia and Canada and how prior learning facilitates acceptance into graduate programs. Discourse analysis was conducted on data collected mainly through semi-structured interviews and analysis of the students’ letters of intent and curriculum vitae. Barring special circumstances, the IELTS was found to be the defining factor in successful graduate applications.
Vascular Modulation of Resting-state fMRI Functional Connectivity
Keywords: Cerebrovascular reactivity
fMRI
Functional connectivity
Functional MRI
Magnetic resonance imaging
Resting-state

Widely used in resting-state fMRI functional connectivity measurement (fcMRI), the BOLD signal is an indirect measure of neuronal activity, inherently modulated by vascular physiology. Notably, cerebrovascular reactivity (CVR) varies across individuals irrespective of neuronal changes, with unknown implications, compromising fcMRI interpretation. This work quantifies the relationship between CVR and resting motor fcMRI in healthy young adults. We modulate CVR within each individual, altering vascular tension through end-tidal CO2 (PETCO2), and measure fcMRI during hypercapnic, hypocapnic and normocapnic states. PETCO2 significantly influenced CVR and fcMRI, but with different directionalities. Resting motor fcMRI was significantly positively associated with CVR across the group, however, the CVR-fcMRI relationship was highly subject dependent. Furthermore, the relationship was not mediated by BOLD signal fluctuation amplitude. This work demonstrates and quantifies a major vascular modulator of resting fcMRI among healthy individuals. We suggest that correcting for CVR in fcMRI is important in studying healthy and diseased brains.
A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial Evaluating the Effect of Intranasal Insulin on Cognition and Emotional Processing in Individuals with Treatment-Resistant Major Depressive Disorder
Keywords: Cognition
Emotion
Intranasal Insulin
Major Depressive Disorder
Treatment Resistance

Aim: Available evidence indicates that individuals with major depressive disorder (MDD) differentially respond to emotionally valenced information alongside impairments in cognition; however, the exact underlying pathophysiological mechanisms subserving these deficits have yet to be elucidated. This thesis represents a proof-of-concept study informed by extant evidence implicating altered brain metabolism and function in individuals with MDD. Methods: Subjects (N=35) were randomized to receive 40 IU QID placebo (n=16) or insulin (n=19) in this double-blind, placebo-controlled, crossover study to examine the effects of intranasal insulin on measures evaluating mood, neurocognition, and quality of life. Results: No significant differences were observed on any primary measures of interest following analyses. However, methodological limitations (i.e., significant carryover/practice effects) should be taken into consideration for interpretation. Conclusion: Intranasal insulin did not demonstrate an effect on mood, neurocognitive/ neuropsychological, or quality of life metrics. Approaches for future trials with intranasal insulin in this clinical population are discussed.
Examining Agreement and Variability among National and International Guideline Treatment Recommendations for Asthma and Bronchiolitis
Keywords: asthma
bronchiolitis
child
clinical practice guideline
pediatric
recommendations

Background: There may be variability in guideline recommendations for a condition. Objective: To determine variability among asthma and bronchiolitis recommendations and related factors. Design/Methods: Kappa, guideline variability index (GVI), and univariable and multiple linear regression analyses were performed. Results: The overall kappa for asthma was 0.03 unweighted and weighted ((95% CI, -0.01, 0.07)(95% CI, -0.01, 0.10)) and bronchiolitis was unweighted 0.32 (95% CI, 0.16, 0.52) and weighted 0.15 (95% CI, -0.01, 0.5). The mean [SD] asthma GVI was 1.7 [0.48] and bronchiolitis was 1.17 [0.92]. Using a multivariable linear regression, mean level of evidence (0.54 (95% CI, 0.0, 1.09)) and mean strength of recommendation (−0.68 (95% CI, -1.30, -0.07)) were significantly associated with variability among asthma guidelines. Conclusions: There was variability among guideline treatment recommendations. Mean level of evidence and mean strength of recommendation significantly contributed to variation in guideline recommendations for asthma but not for bronchiolitis.
Simplified Model for Nonlinear Frequency-dependent Soil with Shallow Foundation
Keywords: Frequency dependent soil
Macroelement
Shallow foundation
Soil-Structure Interaction

This thesis introduces a new approach to seismic Soil-Structure Interaction (SSI) analysis method for shallow foundation using simplified models. The study is inspired by the increasing number of interest amongst engineers and researchers in the nonlinear behavior of shallow foundation as the behavior is unavoidable. The conventional methods of capturing this phenomenon includes a detailed Finite Element Method (FEM) model. However, due to large computational effort in modeling and analysis, it is not a feasible option in the current practice. In this thesis, a method is proposed where macro element for static inelastic behavior and a recursive parameter model for frequency-dependent dynamic characteristics of soil-foundation system are integrated. The proposed method is verified in the two dimensional parametric space of frequency and inelasticity. Then, a practical application example of the proposed modelling method is presented.
Functionalization of Cellulose Nanocrystals with PEG-metal-chelating Diblock Copolymers via Controlled Conjugation in Aqueous Medium
Keywords: Cell imaging
Cellulose nanocrystals
Drug delivery
Nanomedicine

The surface of cellulose nanocrystals (CNCs) was successfully functionalized with metal chelating diblock copolymers via HyNic-4FB conjugation. Two types of PEG-metal-chelating block polymers with hydrazinonicotinate acetone hydrazine (HyNic) end groups were synthesized: mPEG-PGlu(DTPA)18-HyNic and mPEG-PGlu(DTPA)25-HyNic. These two polymers both had a methoxy PEG (M ~ 2000 Da) block that differed in the mean degree of polymerization of the metal-chelating block. They were characterized by 1H NMR spectroscopy and gel-permeation chromatography (GPC). 4-Formylbenzamide (4FB) groups were introduced onto the surface of CNCs and quantified through their reaction with 2-hydrazinopyridine. The polymers were grafted onto the surface of CNCs via bis-aryl hydrazone bond formation, and the kinetics of this reaction was explored by UV/Vis spectroscopy. The CNCs were also labeled with rhodamine and Alexa Fluor® 488 dyes. Students in our collaborator's group in Pharmacy are examining applications of these materials as radiotherapeutic agents for cancer treatment.
Design and Characterization of the UTIAS Anechoic Wind Tunnel
Keywords: aeroacoustic
anechoic
wind tunnel

The anechoic open-jet wind tunnel facility at the University of Toronto Institute for Aerospace Studies was updated and characterized to meet the needs of current and future aeroacoustic experiments. The wind tunnel inlet was resurfaced and flow-conditioning screens were redesigned to improve the freestream turbulence intensity to below 0.4% in the test section. The circular nozzle was replaced with a square secondary contraction that increased the maximum test section velocity to 75 m/s and improved flow uniformity to over 99% across a usable cross-sectional area of 500 mm × 500 mm. Acoustic baffles were installed in front of the wind tunnel inlet and foam wedges were installed in the anechoic chamber. The overall background sound pressure levels in the chamber were improved by 8-18 db over the range of operational freestream velocities. The anechoic chamber cut-off frequency is 170 Hz and the reverberation time for a 60 dB sound power decay is 0.032 s.
Potassium Catalyst Mobility and its Effect on Co-gasification Kinetics
Keywords: catalysis
co-gasification

The mobility of potassium catalyst in various gasification environments was investigated. Tools and methods were developed for mobility studies: (1) intra-particle and inter-particle mobility of potassium was observed with imaging Time-of-Flight – Secondary Ion Mass Spectrometry, (2) a versatile, bench-scale, flow system was designed to study the effect of reaction conditions, feed injection, and pretreatment protocols on the gasification kinetics. Mixed feeds of non-catalyzed and catalyzed feedstocks showed a variety of behaviour attributed to inter-particle mobility. Synergistic behaviour, where total gasification profile improved over the combined separate reactivity, was observed. In other cases, a decrease in combined performance (antagonism) was attributed to catalyst contact with aluminosilicate poisons in certain feedstocks. Preheating of chars, allowing pre-dispersion of potassium, produced higher reactivity than sudden injection. The latter better simulates the reaction history of particles in fluidized-bed gasifiers and indicates that catalyst mobility kinetics will have an effect on gasifier performance.
Social Network Analysis of Asynchronous Discussion in Online Learning
Keywords: asynchronous discussion
constructivism
knowledge building
online learning
SNA
social network analysis

Online learning is often informed by constructivist principles aimed at encouraging collaborative knowledge building through asynchronous online discussion. Social network analysis is uniquely suited to studying these socio-cognitive processes because it emphasizes interactions rather than the attributes of individual participants. This paper uses social network analysis to explore the networks formed by different types of interaction in online discussion and to analyze the ways in which each type of interaction is related to the others. The resulting insights will help instructors design and monitor online courses to facilitate knowledge building as well as to assess both the quality and the quantity of student contributions.
The Effect of Mechanical Ventilation on Lung Epithelial Cell Fate
Keywords: apoptosis
autophagy
BPD
ceramide
lung
ventilation

Premature infants who are subjected to mechanical ventilation (MV) are prone to lung injury that may result in bronchopulmonary dysplasia (BPD), a chronic lung disease characterized by simplification of normal lung complexity. MV induces pulmonary apoptosis and halts alveolar development. However, it is unknown whether ventilation-induced apoptosis is associated with autophagy. I propose that lung epithelial cells subjected to injurious mechanical stretch exhibit cell death by a complex interplay between autophagy and apoptosis. The aims of this thesis are first, to determine the role of autophagy in mechanical stretch-induced lung epithelial cell death, and secondly, to determine the significance of upstream ceramide signaling. I demonstrate that MV of day 7 newborn rat lung as well as mechanical cyclic stretch of fetal rat lung epithelial (FRLE) cells rapidly induces autophagy as shown by increased ATG5-12, ATG7 and LC3B-II production, and autophagosomal formation. Prolonged MV and stretch also induces apoptosis that was attenuated by class III PI3K inhibition as well as by Atg7 siRNA knockdown. By contrast, inhibition of autophagic flux by Bafilomycin A1 enhanced FRLE apoptosis in response to mechanical stretch. Sphingolipid analysis revealed that ceramide levels, in particular of C16 ceramide, were rapidly elevated in response to MV and stretch. C16 ceramide treatment triggered similar temporal activation patterns of autophagy and apoptosis in FRLE cells as seen with mechanical stretch, and activation of both pathways by C16 ceramide was abrogated by Atg7 siRNA knockdown. Sphingomyelin phosphodiesterase 1 (SMPD1) was activated by ventilation and stretch, and its inhibition prevented FRLE cell death by autophagy and apoptosis. These results demonstrate that MV (stretch)-induced SMPD1 activity leads to ceramide accumulation, resulting in lung epithelial apoptosis via autophagy, and identifies SMPD1 as a potential therapeutic target for limiting ventilation-induced BPD.
Cadmium-induced Autophagy and Autophagic Contribution to Cell Death in Cadmium-treated Mesangial Cells
Keywords: Apoptosis
Autophagy
Cadmium
Cell Death
Cell Survival
Mesangial Cells

Cadmium (Cd) is a nephrotoxic metal that has a number of consequences for renal function. Cells exposed to Cd may have methods to counteract toxic effects with processes like autophagy. Autophagy is an intracellular degradation system that delivers cytoplasmic constituents to the lysosome. This study investigated the mechanism of Cd-induced autophagy, and the relationship between autophagy and cell survival. At 10 µM exposure for 24 hours, Cd-induced autophagy was found to be reactive oxygen species-independent, and suppressed with thapsigargin treatment, suggesting the necessity of intracellular Ca2+. Inhibition of the Jun-N-Terminal Kinase resulted in the greatest suppression of Cd-induced autophagy. Autophagy was found to be protective against cell death elicited by the toxic metal, and the absence of autophagy resulted in increased apoptosis in mouse embryonic fibroblast cells. This study adds insight to the mechanism and protective effects of Cd-induced autophagy, and provides the groundwork for future experiments.
Towards a Chromatic Pupillometry Protocol for Assessing Melanopsin-driven Post-illumination Pupil Response in Basic Science and Clinical Investigations
Keywords: chromatic pupillometry
melanopsin
post-illumination pupil response
pupil light reflex

The pupillary light reflex (PLR) is mediated by intrinsically photosensitive retinal ganglions cells (ipRGCs), a sub-group of retinal ganglion cells that contain photopigment melanopsin. Melanopsin activation drives a sustained pupil constriction after the offset of light stimulus, this so-called post-illumination pupil response (PIPR) is an in vivo index of melanopsin-driven ipRGC photoactivity. PIPR can be assessed by chromatic pupillometry, but consensus on a standardized PIPR testing protocol has not been reached yet. The purpose of this thesis is to develop an optimized PIPR testing methodology, and to use it to investigate clinical and basic science questions related to melanopsin and ipRGCs. Based on previous pilot work on full-field chromatic pupillometry, a new and repeatable method was developed to measure PIPR induced by hemifield, central-field and full-field light stimulation. This chromatic pupillometry system was then used to investigate a series of basic science and clinical questions related to melanopsin and ipRGCs.
Application of Nanofiltration for the Recovery of Phenolic Compounds from the By-product of Yellow Mustard Protein Isolation
Keywords: Mustard
Nanofiltration
Phenolic compounds

Nanofiltration (MWCO 150-300 Da) was evaluated for the recovery of phenolic compounds from the wastewater of the production of yellow mustard protein isolates. High rejections were observed; however, under alkaline pH lower average rejections were shown (0.70) than acidic conditions (0.87). Fluxes of 51.3 L/hm2 and 28.8 L/hm2 were registered under alkaline and acidic conditions, respectively. At low pH, 77% of the phenolic compounds fed to the process were recovered in the retentate. Diafiltration was beneficial only when processing at low pH. The permeate from the nanofiltration process presented a total phenolic content of less than 100 ppm, which suggests the possibility of recycling these effluents to the production of yellow mustard protein isolates. p-Hydroxybenzoic acid was the major phenolic compound found in the waste effluent, and in the products of nanofiltration processing. Sinapic acid constituted a secondary fraction, and derivatives of quercetin and kaempferol were detected.
X-ray and Electrochemical Impedance Spectroscopy Diagnostic Investigations of Liquid Water in Polymer Electrolyte Membrane Fuel Cell Gas Diffusion Layers
Keywords: electrochemical impedance spectroscopy
liquid water visualization
mass transport resistance
microporous layer
Polymer electrolyte membrane fuel cell
synchrotron radiography

In this thesis, electrochemical impedance spectroscopy (EIS) and synchrotron x-ray radiography were utilized to characterize the impact of liquid water distributions in polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layers (GDLs) on fuel cell performance. These diagnostic techniques were used to quantify the effects of liquid water visualized on equivalent resistances measured through EIS. The effects of varying the thickness of the microporous layer (MPL) of GDLs were studied using these diagnostic techniques. In a first study on the feasibility of this methodology, two fuel cell cases with a 100 µm-thick and a 150 µm-thick MPL were compared under constant current density operation. In a second study with 10, 30, 50, and 100 µm-thick MPLs, the liquid water in the cathode substrate was demonstrated to affect mass transport resistance, while the liquid water content in the anode (from back diffusion) affected membrane hydration, evidenced through ohmic resistance measurements.
A Phenomenological Study of Loving Kindness Practice in Education Settings
Keywords: Eros
Imagery
Loving Kindness
Meditation
Phenomenology
Teacher Emotional Life

This study uses Phenomenological research methods to explore the ways in which four teachers recited Loving Kindness Meditation for a three week period, particularly focusing on their students during the course of practice. Through personal reflection, journaling and interviews, the teachers describe how Loving Kindness Meditation affected their emotional life as teachers, their experiences of students and classroom dynamics, and the challenges experienced when reciting Loving Kindness Meditation to students. The study reveals a tendency for teachers to adopt a more yielding, less controlling orientation toward student encounters as their practice of Loving Kindness Meditation progressed. The study also hints at problematic limits to over-reliance on meditative imagery, redefining Eros in teacher-student dynamics as a surrender of idealistic expectations of student reciprocation. Future research could more deeply unpack the psychodynamic impacts of Loving Kindness on caregiver identities.
Community composition and Biogeography of northern Canadian Ephemeroptera, Plecoptera and Trichoptera
Keywords: Aquatic insects
Arctic
Barcode COI
Biogeography
Community composition

Climate change has a disproportionately effect on northern ecosystems. To measure this impact we need to understand the structure of northern communities and the influence of current and historical climate events. Insect of the orders Ephemeroptera, Plecoptera and Trichoptera (EPTs) are excellent subjects for study because they are widespread and good bioindicators. The objectives of this study are: (1) Determine patterns of distribution and community composition of northern EPTs. (2) Understand the role of historical events (i.e., Pleistocene glaciations). We found that northern EPT communities are influenced by temperature and precipitation. Also, community composition and population structure of EPT exhibit a similar geographical pattern, with differences on either side of Hudson Bay, suggesting the influence of glaciations in shaping communities of EPTs in northern Canada. The COI barcode approach provided a reliable means for identifying specimens to produce the first wide-scale study of community structure and biogeography of northern EPTs.
Characterization of Hot Surface Ignition in a Direct Injected Natural Gas Combustion Apparatus
Keywords: Diesel
Direct Injected
Engine
Glow Plug
Hot Surface Ignition
Natural Gas

The process of hot surface ignition of direct injected natural gas using a shielded glow plug was studied in an optically accessible combustion apparatus by varying combustion chamber design and operational parameters. Parameters studied were glow plug temperature, relative angle of the fuel injector and the glow plug shield, and the fuel injector nozzle orifice size, shape, and angular spacing. Results were analyzed using ignition delay time, fuel utilization, rate of heat release, and acquired high speed combustion images. Glow plug temperature had a dominant effect on ignition delay in comparison to all other parameters. Fuel injector nozzle design, along with the geometric interaction between the fuel injector and the glow plug shield, had a strong effect on the air fuel mixture available for ignition in the vicinity of the glow plug. Results will be used to inform the design and operation of a hot surface assisted natural gas engine.