VictorJuiz/thesis huggingface dataset:
From Right to Left: Interhemispheric Interactions while Seeing Words and Hearing Sentences
Keywords: Aphasia
Hemispheric interactions
Language
Word recognition

The corpus callosum is the largest fiber bundle in the human brain and mediates communication between cerebral hemispheres through a combination of excitatory and inhibition interactions. The balance between excitation and inhibition has been clearly defined for certain perceptuomotor processes, but not with language. This dissertation outlined the interhemispheric interactions involved in sentence comprehension in aphasia patients (studies 1 and 2) and word recognition in healthy adults (studies 3 and 4). Aphasia is commonly associated with right hemisphere activation, which has been attributed to both inhibitory and excitatory mechanisms. Study 1 demonstrated a positive relationship between left hemisphere dysfunction and right hemisphere language activation, which could have resulted from either disinhibition or excess recruitment of the right hemisphere. Study 2 examined these two hypotheses using Dynamic Causal Modelling of fMRI. Healthy controls showed no evidence for interhemispheric homotopic inhibition, but instead demonstrated excitatory right-to-left connectivity between primary auditory cortices. Critically, auditory connectivity was associated with language recovery in patients; the worst performing patients lacked typical right-to-left excitation, and showed atypical left-to-right excitation. Studies 1 and 2 provide two very interesting results: 1) healthy language processing requires asymmetrical right-to-left perceptual transfer and 2) right hemisphere activation in aphasia results from atypical excitatory recruitment. Interhemispheric interactions between perceptual regions was further explored in study 3 using a lateralized lexical decision task with MEG. In line with results from study 2 and the broader word recognition literature, the results showed an asymmetrical transfer of visual information from right to left hemisphere. Importantly, the results add to the current literature by demonstrating transfer between primary visual cortices, at one of the earliest processing stages of word recognition. Finally, study 4 showed that simultaneous bilateral word recognition was facilitated when word pairs were semantically related. These findings again suggest that the interhemispheric interactions in word recognition are primarily excitatory. The four studies in this dissertation found consistent evidence for interhemispheric excitation in language processing. While there is clear evidence for inhibition in some language processes, the current studies suggest that both sentence comprehension and visual word recognition are primarily associated with excitatory interhemispheric interactions.
MICROSIMULATING WEEK-LONG OUT-OF-HOME TRAVEL/ACTIVITY PATTERNS
Keywords: Activity-based
Discrete choice modelling
Microsimulation
Random utility maximization
Travel demand modelling
Week-long

This thesis reports on significant progress in several aspects of activity-based travel demand modelling. The major contribution is extending the time-frame of the activity-based models by developing two week-long travel/activity patterns prediction models. The two models differ in the way they schedule work activities. In the first model, work, school and night sleep are considered as the skeleton schedule around which non-work/school activities are organized. Weekly work activities are scheduled in a separate framework applying the concept of a “project” which consists of work episodes which are planned prior to the week (preplanned) and episodes planned during the week (unplanned). These episodes are generated and scheduled in a two-level, weekly, dynamic framework. In the second model, night sleep is the only skeleton schedule and the rest of the activities including work and school are generated and scheduled simultaneously. The results indicate the significance of developing models with longer planning horizon than a typical weekday. The other main contribution of the thesis is investigating the influence of a fundamental assumption in activity-based modelling which is assigning a higher priority to scheduling work/school activities on the predicted travel/activity pattern of the non-work/school activities. The thesis also tests the forecasting ability of the developed models, something which is rarely done in the literature. The modelling structure applied in this thesis is estimated on two different datasets: a small-sample computerized activity survey with a fine level of disaggregation and high level of detail of the activity and socioeconomic attributes, and a large-sample trip-based dataset with a high level of aggregation and few number of socioeconomic attributes. Simulated schedules applying models developed on each dataset indicate that using the activity survey leads to a more accurate and behaviourally representative model. The study also demonstrates the importance of a higher level of disaggregation of activity types than occurs in common practice.
Cyber-Physical Modeling and Analysis for Smart Grids: Resiliency Cyber Security
Keywords: cybersecurity
distributed control/algorithm
energy storage
resilience
smart grid
stability

Traditional resiliency studies of infrastructure system such as the power grid focused on a context defined by extreme events and natural disasters. However, the increased dependability on cyber tools and networks combined with the rise of serious cyber-based threats thrust resilience to be a strategic approach for planning, design and operation. This dissertation invests on a cyber-physical model of the smart grid and is motivated by the benefits of understanding the interactions between the cyber and physical domains and coordinating adaptive capacity resources for an enhanced resilient operation. We first consider how to improve the resilient operation of existing power systems. We adopt an energy storage (ESS)-based feedback linearization control to address transient stability. The control is studied in centralized, distributed and decentralized architectures, then the different architectures are recognized as modes of operation of an adaptive controller that responds to cyber and physical disturbances. Observed performance limitations of the proposed control are investigated in our study of cyber-physical interactions. A cyber-physical hybrid graph is constructed based on an equivalent impedance interpretation of a communication link performance in relation to physical power systems’ dynamics. The proposed hybrid graph constitutes a representation of the system in the cyber-physical domain. The impact of the ESS-based control in enhancing transient stability is then studied from a resiliency perspective. The combined impact of the ESS, sensory and associated control is analytically studied using a proposed effective virtual inertia measure. The proposed measure reflects the adaptive capacity introduced into the power system by the ESS-based control. We next consider evolving distribution systems and how coordinated operation of these systems can adopt a resilient-by-design approach. Microgrid networks present a system-of-systems architecture comprised of autonomous entities and distributed built-in adaptive capacity that can be coordinated to achieve further benefits and enhanced resilience. A coalition constrained cooperative game-theoretic distributed algorithm is developed to coordinate resources between microgrids. Finally, we develop a new class of switching attacks that exploits existing system vulnerabilities using an adversary threat model with limited resources. The study emphasizes the importance of addressing existing vulnerabilities in the power system for an improved resilience.
MRI Characterization of Peripheral Arterial Disease for Planning Percutaneous Vascular Interventions
Keywords: chronic total occlusions
critical limb ischemia
endovascular
MRI
peripheral arterial disease
vascular imaging

Peripheral arterial disease (PAD) is a common, chronic problem with significant morbidity and mortality. When PAD is severe, it is called “critical limb ischemia” and in this subset of patients up to 40% require a major amputation within just one year of diagnosis. Current treatment options involve revascularizing the leg through either bypass surgery or percutaneous vascular intervention (PVI). PVI offers a less invasive approach with improved morbidity and shorter length of hospital stay compared to surgery. However, PVI has high immediate technical failure rates (20%) and high re-intervention rates (~30%). The most common mode of immediate technical failure is the inability to enter or cross the target lesion due to the mechanical properties of the lesion. With current imaging, it is impossible to predict which lesions will be soft enough to cross with a wire to make PVI possible. This thesis addresses gaps in knowledge about how to appropriately select patients for PVI using novel imaging techniques. We have developed an MRI method using ultrashort echo time and steady state free precession flow-independent imaging that characterizes hard versus soft peripheral arterial lesion components and related those characteristics to ease of crossing during PVI. We performed ex-vivo studies using high-resolution MRI to define the signal behavior of individual lesion components and demonstrated high diagnostic accuracy by comparing images with microCT and histology. Further, we demonstrated that MRI signal behaviour could differentiate lesions that required high guidewire puncture forces from lesions that are easy to puncture. We translated this technique to a clinical protocol and validated images of amputated limbs with ex-vivo high-resolution MRI, microCT and histology. Finally, we imaged patients with the clinical protocol prior to their PVI, and demonstrated that MRI could identify lesions that took significantly longer to cross with a guidewire and required stenting more often. This thesis presents an original contribution to knowledge with the development and validation of a new MRI diagnostic test that can determine which peripheral arterial lesions are more difficult to cross with a guidewire. Future work will determine if MRI lesion characterization can predict long-term endovascular outcomes to aid procedure planning.
Voices of Urban Aboriginal Peoples with Diabetes
Keywords: Indigenous Health
Indigenous Studies
Multi-Media Communications
Nutrition

This art based research study is situated within an Indigenous research methodology. The goal of the research was to first, document the voices of Urban Aboriginal people with Type 2 diabetes and secondly, to bring together these voices into an updated oral format using the medium of radio. Four principles that grounded this research were Indigenous research paradigm, drawing from Indigenous scholars, critiquing the Euro-Western biomedical worldview of health, and reciprocity. Using an Indigenous research paradigm meant situating who I am as a Nahayowak (Cree) woman who used prayer, medicines and talking with Elders to carry out the research. Second, I ensured the bulk of the reference sources were Indigenous writers. Third, the research was undertaken knowing that health is situated in a colonial Euro-Western biomedical worldview and if the health of Indigenous people is to improve I must assert Indigenous ways of doing research; and finally, any work I do must have a component of reciprocity where knowledge and pragmatic tools, podcast of radio documentary, must be given back to not only the academy but to students and Indigenous community members. Reciprocity must be seen as the ‘gold standard’ in any work that Indigenous scholars do when working to change the situation of Indigenous peoples. The theoretical underpinnings of this research are four aspects of self, visually represented in the Nahayowak Medicine Model by Ghostkeeper as the mind, body, emotions and spirit. I was motivated to do this research when I found out 50% of my relatives had diabetes and when the Canadian Diabetes Association in 2002, and again in 2015, stated there is still a stigma associated with diabetes that prevents Aboriginal people from disclosing their diabetes. For this study there were seven Indigenous people who agreed to participate because they also wanted to create a space for other Aboriginal people to be able to talk about diabetes without shame or guilt. They hope their story will allow others to share their diabetes story. The interviews became a radio documentary that ensured views were broadcasted about Indigenous people living with diabetes from an Indigenous perspective that was directed toward other Indigenous people.
Performance Approach in the Recorded History of Alban Berg's Piano Sonata, Op. 1
Keywords: Alban Berg
Glenn Gould
Performance Studies
Performance Theory
Recordings
Second Viennese School

Growing discomfort with musicology’s ease in viewing the score as synonymous with act has propelled recent work in performance studies. Preoccupation with urtexts has encouraged the singularity of composer’s intent while discouraging inquiry into the mosaic of interpretative approach where performance practice and musicality can be essayed. Research into recordings that reveals performers’ agencies allows problematic assignment of composer’s intent to be eroded, demystifies artists’ aesthetics, underscores the plurality of musical approach, and details the systems used to bring the score into sound. My thesis considers the recording history of Alban Berg’s Piano Sonata, Op. 1. Chapter 1 examines fifteen performers’ approach to the first twelve measures, enabling their categorization according to temporal shape, structural articulation, and score fidelity. Descriptive analysis was joined with empirical data on rubato, facilitated by the application Sonic Visualiser. The resulting classifications reveal performance practice, tradition, and aesthetic. Chapter 2 investigates Glenn Gould’s longtime relationship with the work. Timing, manual asynchrony, and temporal shape are discussed in his eight performances encapsulated on various media; and Gould’s changing aesthetic through three separate decades is analyzed. Chapter 3 explores the intersection of music theory and performance. Music theorists’ motivic, harmonic, and formal analyses are reviewed and juxtaposed against performers’ articulation of motivic and formal structure. The results demonstrate that performers’ and theorists’ segmentation of themes and form often align, with divergences encouraging further points of discussion. My thesis reveals that performing is itself a practice, in constant flux and governed by interpretative methodologies resulting in deviation from the literal execution of the score. If practice evolves, so too must the pieces these systems realize. That works are not fixed entities emphasizes the social construction of musical taste. Ultimately, it is hoped that this research will undermine problematic assignment of composer’s intent and assist in the ontology of practice and musicality.
Stress Systems and Brain Maturation During Adolescence
Keywords: brain maturation
development
gene expression
hormones
puberty
stress

Adolescence is a transitional period that involves a number of biological (including sexual maturation) and social changes (e.g., conflicts with peers and adults) that may contribute to brain maturation. Studying the factors that influence changes in the adolescent brain can help us understand brain-behaviour relationships. In this thesis, I focused on how the hypothalamic pituitary adrenal (HPA) axis (i.e., the “stress system”) influences brain maturation (namely, pituitary volume and cortical thickness) during adolescence. I used novel techniques to examine the relationship between HPA axis regulation and activity on brain development during adolescence, as well as how the hypothalamic pituitary gonadal (HPG) axis interacts with the HPA axis in the context of brain development during adolescence. I examined these relationships in a community sample of adolescents (n = 1019, ages 12-18) from the Saguenay Youth Study. In Chapter 2, I validated a segmentation algorithm that estimates the volume of the pituitary gland. Using this segmentation algorithm, I found that age, puberty status, testosterone, and estradiol were positively associated with pituitary volumes in adolescents. In Chapter 3, I calculated a polygenic score based on a panel of genetic variants that were related to the activation of the glucocorticoid receptor (GR) for each participant. With the GR-related polygenic scores, I found that it was positively associated with cortisol levels and pituitary volumes in adolescents. In Chapter 4, I used the expression profiles of genes from the Human Brain Atlas to examine its relationship with age-related cortical thinning across the brain in adolescents. I found a positive relationship between inter-regional variations of NR3C1 and AR mRNA expression and age-related cortical thinning across the brain. In this thesis, I combined the field of genetics, endocrinology, and developmental neuroscience to understand the stress-system and brain maturation during adolescence.
"Thank goodness you are a man!": Troubling Gender and Principal Leadership in Elementary Schools
Keywords: Education
Elementary Principal
Gender
Leadership

This study identifies and critically examines gendered discourses of leadership amongst elementary school principals. Interviews with 15 female and male elementary school principals in the Greater Toronto Area were carried out as a means of discovering and revealing these gendered discourses. A discourse analysis of their responses is conducted. A feminist post- structuralist approach to analysis gives rise to a series of gendered discourses of principal leadership, revealing the manner in which these discourses act upon elementary principals. These discourses are divided into three areas: discourses of female principal leadership, discourses of male principal leadership and finally, discourses of reluctance and denial. The work of Michel Foucault is used to understand how dominant discourses work upon the subject through disciplinary power and governmentality. The revelation of these discourses provides opportunities to challenge them. This study illustrates the way these discourses work to both limit and, in some cases, legitimize the elementary principal depending on each principal’s gender. A process by which principals deny the influence of gender on their leadership, then accept and recognize its influence, is analyzed. Pierre Bourdieu’s notion of symbolic violence is used to explore the workings of masculine domination upon both men and women, revealing the suffering experienced by principals as a result of this domination. The wider implications of these gendered discourses on the role of elementary principal are discussed. Moments of resistance to the dominant discourses and agency are also discussed when they are revealed through dialogue with the principals. The work of Judith Butler is used to explore the presence of agency amongst these principals and the implications it has for principals as they navigate these gendered discourses. This study positions principalship as a place where resistance and agency can be explored and realized. Implications for theory and further research are considered.
The Molecular Evolution of Cetacean Dim-Light Vision: In Vitro Studies of Rhodopsin Over a Macroevolutionary Transition
Keywords: adaptive evolution
codon models
protein evolution
site-directed mutagenesis
visual ecology
visual pigments

Cetaceans (whales and dolphins) are fully aquatic mammals that have captured the imagination of biologists due to their iconic evolutionary transformation from terrestrial ancestors. Nevertheless, much about how this extreme macroevolutionary transition occurred at the molecular level remains unknown. The vertebrate visual system is ideal for studying molecular adaptation due to the reliance organisms place on it for fitness-related behaviours, and because key molecular components of the visual transduction cascade in photoreceptors are relatively well understood. Light activation of the dim-light pigment, rhodopsin, is the first step of the visual transduction cascade, and is thought to have been the target of selection across a wide variety of vertebrate lineages. Cetaceans, due to their rich evolutionary history, are model organisms for understanding how changing environments put selective pressure on sensory processes. In this dissertation, I investigate the molecular basis for adaptive evolution in cetacean rhodopsin using a combination of in vitro expression experiments and computational analyses. First, I evaluate evidence for adaptation in cetacean rhodopsin through characterization of its spectral properties in the killer whale (Orcinus orca), and a statistical assessment of selection patterns in a representative dataset of cetacean rhodopsin genes. Next, I focus on the evolutionary significance of key amino acid substitutions in killer whale rhodopsin that confer both spectral and non-spectral (kinetic) functional shifts, specifically through comparison with rhodopsin pigments from two outgroup species (bovine and hippopotamus). Finally, I use an ancestral sequence reconstruction and protein resurrection approach to establish functional and corresponding molecular shifts across the terrestrial-aquatic transition at the root of Cetacea. Together, these projects provide a more complete investigation of cetacean rhodopsin, not only addressing questions regarding dim-light (aquatic) adaptation in cetaceans, but also generating new hypotheses about how the ecology of living and ancient cetaceans has shaped the visual system.
Cellulose Biosynthesis has Extensive Impacts on Overall Plant Metabolism Potentially Mediated, in part, by Peptide Signals
Keywords: Arabidopsis thaliana
cellulose
cell wall
CMP-NMR
glycine-rich peptides
glycine-rich proteins

As sessile organisms, plants must continually adapt to their environment. In order to allocate resources appropriately, plants have elaborate pathways in place for detecting and responding to changes in their environment and the integrity of their cells, particularly the cell wall. Cellulose is the major component of plant cell walls and a major sink for carbon in the plant body. Cellulose is central to plant structure and function, imparting sufficient strength and resilience to withstand turgor pressure, negative pressure, and gravity. It was therefore hypothesized that plants have broad, far-reaching metabolic responses to cellulose disruption. To uncover the response to cellulose perturbation at the metabolic level, Comprehensive Multiphase-Nuclear Magnetic Resonance (CMP-NMR) was used in combination with a mutant analysis and pharmacological experimentation. This approach revealed several metabolic impacts of cellulose perturbation that were previously unknown, including decreased metabolism of seed lipid stores during germination, increased production of methanol and ethanol in seedlings, and the presence of pentaglycine in seedlings. Another line of investigation revealed that a compound or compounds present in the cellulose synthase mutant eli1 was able to increase lignin content of wild-type seedlings. Pentaglycine had a similar effect on WT seedlings. Taken together with the increased abundance of pentaglycine in eli1 seedlings, the results suggest that pentaglycine is in part responsible for the increased lignin content that characterizes cellulose synthase mutants. A model is presented that integrates these components into a signaling pathway to monitor and respond to perturbation in the cellulosic component of cell wall integrity.