VictorJuiz/thesis huggingface dataset:
Macrophage Surveillance and Immunity: Eating, Drinking, and Digesting
Keywords: Cresyl violet
Lysosome
Macrophage
Macropinocytosis
Phagocytosis
Podosome

Professional phagocytes actively patrol the tissues to remove debris, pathogens, and apoptotic bodies. This daunting task requires clearance of hundreds of billions of apoptotic cells produced each day and the never-ending assault by external pathogens. In the phagocyte toolbox are macropinocytosis to sample large volumes of extracellular fluid, and phagocytosis to internalize objects >0.5 μm in diameter. These processes form the core of phagocyte activity and require 1) efficient formation of the macropinosome/phagosome, 2) maturation of the resultant compartment, and finally 3) fusion with acidic lysosomes. In this dissertation, I explore each of these three topics presented as self-contained chapters. I characterize the organization of integrins and F-actin within the forming phagocytic cup to form podosome-like structures under the coordination of phosphoinositide signaling. The function of these structures is demonstrated to be the formation of a progressively expanding sealing zone with the phagocytic prey. I also explore the fate of luminal calcium in the maturing macropinosome and its transport into the phagocyte cytosol. In the final study I characterize a novel sensor for the labeling and study of acidic compartments, including phagolysosomes. Crucially, this probe, cresyl violet, is demonstrated to be both more stable and affordable than current alternatives.
An exploration of the Role of Mentorship in Advancing Women in Coaching
Keywords: Ecological model
Mentorship
Mixed-methods
Sponsorship
Women in coaching

Women coaches continue to be underrepresented in the coaching domain (LaVoi, McGarry, Fisher, 2019) despite the growth and advancement of women in non-sport fields (Statistics Canada, 2017). A notable strategy used to develop and advance women in non-sport sectors is mentorship and while mentorship initiatives currently exist for women in the coaching domain, we know little about women coaches’ experiences of mentorship, what they learn and how they develop through mentorship, and how they can be better supported through mentorship to facilitate career advancement. The purpose of this dissertation, therefore, is to explore the role of mentorship in the advancement of women in coaching. A mixed methods approach was used in this study, which led to the production of three manuscripts: 1) Towards a process for advancing women in coaching through mentorship; 2) Benefits of a Female Coach Mentorship Program on women coaches’ development: An ecological perspective; and 3) Key considerations for advancing women in coaching. The findings from these studies provide much needed empirical data on the role of mentorship in women coaches’ growth and advancement, and more specifically, on the importance of process-driven and group-based mentorship for women coaches, the need for greater organizational involvement and macro-level changes in mentoring women coaches, and the need to shift to sponsorship to help advance women in coaching.
Chercher La Vie: Births, Deaths, Labour and Militarized Border-crossing among Sex Workers in an Area of Armed Conflict in Eastern Democratic Republic of Congo
Keywords: Armed Conflict/War
Gender/Sexuality
Health
Maternal and Child Mortality
Political Economy
Sex Work

This dissertation is a study of sociality and power in armed conflict. It is based on ethnographic research with two groups of women who sell sex in eastern Democratic Republic of Congo, self-identified “bambaragas”. These women travel back and forth across militarized lines in areas of armed conflict to perform sex work and other complementary labour and to trade with a variety of different state and non-state armed groups. This study argues that any attempt to understand sociality and power in war must grapple centrally with non-violent death. The combined effects of armed conflict and privatization contributed to mass infant, child and maternal death. Bambaragas and their children bore a distinct and disproportionate death burden. Hospitals sat at the intersection of governance of health as a private commodity rather than a public entitlement, by both the state and non-state armed groups. This resulted in policies within hospitals of refusing emergency care, abusing and punishing women suspected of abortion, imposing debt and extracting payment, and forcibly detaining women who couldn’t pay for their or their children’s care. This study also contends that gender is central to the workings of power in armed conflict. Armed groups’ governance of bambaragas fluctuates around a central tension: while their labour was relied upon by armed groups, to the point of becoming at times a stake in the conflict, their gendered independence and border-crossing meant they were treated with suspicion and, at times, targeted and killed not as civilans nor as military actors but as what I call “sovereign women/gendered traitors”. Bambaragas’ mutual recognition and collective practices of assistance, secrecy, care and housing allowed women to navigate dangerous conflict environments and predatory privatized health governance and was, at times, what allowed women to keep their children alive and in their care.
Socio-cognitive Dynamics of Knowledge Building Communities: A High-school Physics Case Study
Keywords: building
knowledge
physics
presence
social

The results of this research provide an account of advances in foundational knowledge of black-hole physics through analysis of idea improvement and social presence in Grade 12 Knowledge Building classes. The purpose of this study is to collect and analyze student discourse and interactions to uncover socio-cognitive dynamics in an online environment—Knowledge Forum®—designed to support Knowledge Building. Questions students raised were assessed along a continuum from simple clarification and fact-seeking to explanation seeking; explanations were analyzed along a continuum from unelaborated facts to elaborated explanations. Conversation thread length was analyzed, in addition to quality of foundational knowledge of physics represented in student notes, as judged by experts in modern physics. As a separate check on adequacy of foundational knowledge, one Grade 12 group was administered a test designed for first-year university students taking a course in cosmology. The Grade 12 students did as well as the university students. Social interactions were quantified within discussion threads using social presence to identify affective, cohesive and interactive markers of engagement. According to both expert judgment and co-occurrence of the broad array of measures of idea improvement and social presence, students demonstrated impressive levels of understanding black-hole physics. Additionally, all markers pointed to one group displaying especially high-levels of collective responsibility for community knowledge. Those results are consistent with the teacher's impression that a Knowledge Building esprit de corp characterized the most successful student group. Accordingly, exploratory work to develop an analytic tool was conducted — a tool to combine measures and indicators to allow teachers and students to monitor socio-cognitive markers of collective responsibility for community knowledge as work proceeded.
Magnetar X-ray Spectra: An Utramagnetic QED Approach
Keywords: magnetic fields
plasmas
radiation mechanisms: general
relativistic processes
scattering
stars: magnetars

This thesis considers the generation of the bright, broadband and non-thermal X-ray spectra of magnetars. These spectra are very sensitive to the distribution of electrons and positrons in the current-carrying magnetic field tubes; previous approaches considered generating the non-thermal components by modifying a seed thermal spectrum with resonant cyclotron upscattering on ultrarelativistic outflows, as well as through bremsstrahlung and synchrotron emission. The present approach constructs a Monte Carlo model of this persistent emission, where both ``AXP-like'' and ``SGR-like'' spectra are generated self-consistently as a result of the interaction of a warm magnetospheric plasma layer and a cold, dense neutron star atmospheric surface layer. This approach is motivated in part by evidence that the magnetospheric currents are strongly localized. In order to construct this model, a range of QED rates and cross sections are reviewed and calculated in the ultramagnetic background, many for the first time. In particular, the high electron-positron scattering and bremsstrahlung rates as well as the highly kinematically modified rates of two-photon pair creation and annihilation lead to a physical situation that differs qualitatively from previous models, including unique potential observational signatures.
Analysis of Visual Scanning Behaviour in Patients with Psychiatric Disorders
Keywords: Deep learning
Eye tracking
Neural networks
Psychiatric disorders
Psychology
Visual attention

The diagnosis of psychiatric disorders often relies on clinician’s interviews and self-reported questionnaires. These techniques suffer from inter-observer variability and are often affected by communication difficulties between clinicians and patients. Analysis of visual scanning behaviour (VSB) is a method that can help to objectively characterise patients with psychiatric disorders. The main goals of this thesis are to a) develop novel techniques to analyse VSB and b) to develop novel experimental paradigms that are based on the analysis of VSB to assess cognitive processes. Data driven methodologies based on recurrent neural networks (RNN) were developed to learn visual scanning sequences of patients with mood disorders and patients with Alzheimer’s disease (AD). The method that was developed for patients with mood disorders is based on the analysis of VSB on human faces and can differentiate between patients with bipolar or unipolar depression with an area under the curve (AUC) of 0.879 (a gain of 0.276 relative to expert systems). The method that was developed to detect emotional blunting in AD patients could learn the individual’s “style of scanning” and can differentiate between apathetic and non-apathetic patients with AUC of 0.814 (0.646 for an expert system). Novel experimental paradigms were developed to assess the potential for conversion to AD in mild cognitive impairment (MCI) patients and a surrogate marker for the detection of structural damage to white matter tracts in patients with post-concussion syndrome (PCS). The paradigm for the assessment of MCI patients is based on measurements of novelty preference (NP) where repeated images appear after short delays (≤12.5 seconds). For short delays, NP is dependent on intact familiarity-based recognition memory. The marker for structural damage to white matter tracts in PCS patients is based on a novel visual scanning version of the matching familiar figures test (MFFT). VSB measures during the MFFT test were correlated to the microstructural integrity of the corpus callosum (r=-0.281, p=0.0141). In summary, the work in this thesis shows that by using novel paradigms and novel analysis techniques, VSB can provide valuable insights that can support the diagnosis and treatment of patients with psychiatric disorders.
Examination of Black Entrepreneurs in Toronto, Canada: Critical Analysis of the Role of Financial Literacy
Keywords: antiblack racism
Black Studies
education
entreprenurship
financial literacy

American entrepreneur Jim Rohn stated that “Formal education will make you a living; self-education will make you a fortune” . This research on lived experiences of Black businesses in Toronto has relied on self-education. Bogan and Darity (2008) argue that policymakers and scholars alike consider self-employment as an alternative to unemployment and a route out of poverty. This dissertation examines the historical and contemporary experiences faced by Black businesses in Canada, and in particular the Greater Toronto Area. In addition, this research examines the role of financial literacy education amongst the Black community. This dissertation argues that to understand the challenges within the Black business community, consideration of the complexities of Black identity, in antiquity and modernity, have shaped and influenced the Black narrative in not only stories of heroics and affirmation but betrayal, pain, and contestation, which has had a severe impact on economic prosperity within the Black community as a collective. Using theoretical frameworks that employ an analysis of anti-Black racism, anti-colonialism, and Indigenous knowledges as analytic tools, combined with literary exploration, this dissertation examines the impact of historic and systemic trauma on Black business owners with profound economic implications to their communities that continue to reproduce coloniality, discrimination, and racism. The findings of this research will add to the discourse on systemic, historical, and contemporary barriers that have hindered the growth of Black businesses in Canada. Unearthing the historical and contemporary barriers that have hindered the growth of more Black businesses in Toronto is needed to create an economic blueprint for future Black entrepreneurs to overcome economic, social, political, and psychological adversity. The findings enable scholars, policy-makers, and practitioners to better appreciate the possibilities and difficulties which characterize and frame attempts by Black entrepreneurs in Toronto that advance and/or hinder the sociopolitical and economic environment of Black bodies in Canadian communities.
Standard Language Ideology and World Englishes: A Multiple Narrative Case Study of Immigrant Educators’ Experiences in Canada
Keywords: educators
intersectionality theory
standard language ideology
world Englishes

The spread of English and its users across the world has made imperative, an exploration of the language education histories and experiences of immigrant educators who use Outer Circle English varieties in Inner Circle countries. Using an interpretivist approach, this multiple narrative case study explores tensions between standard language ideology and Outer Circle varieties of English as well as their effects on the experiences of educators in Canada who use Outer Circle English. In Inner Circle countries, power imbalances embedded in ideologies about standard English and varieties of English from Outer and Expanding Circle countries can influence the trajectories of immigrant educators. World Englishes scholars have focused on history, definitions, teaching models, native versus non-native speaker dichotomies, language testing and discrimination, while narratives from Outer Circle English users, educated in both Inner and Outer Circle countries are noticeably lacking. Kachru’s concentric circles English model, organized along geopolitical and ideological lines, underpins this discussion about the status and spread of world Englishes. Intersectionality Theory is deployed as the main heuristic in order to explore the experiences and identities of educators who use Outer Circle English varieties. Further, Bourdieu’s notions of linguistic capital - wherein language is understood as capital mediated by social and power relations - facilitate this inquiry into language as a site-of-struggle, its effects, as well as resilience and agency. This study culls from data collected from ten educators in Canada who come from one former American colony and six former British colonies. Data include questionnaires, semi-structured interviews and language autobiographies. Participants’ language education histories and how their language-related experiences have shaped various facets of their lives inform the results of this study. Findings include narratives about heritage, education, teaching practices and research activities that showcase participants’ linguistic, personal, cultural and professional identities. Narrative inquiry fosters a deeper understanding of how participating educators’ experiences influence their multiple and fluid identities, teaching philosophies and pedagogical practices. Narrative provides opportunities for showing connections between participants’ histories, professional trajectories and belongingness. Implications for further research into linguistic variation, social selection and opportunities for educators who use Outer Circle English are discussed.
Resilience Factors and Mental Health among LGBTQ Adults in Canada and the United States
Keywords: Attachment Dimensions
LGBTQ
Mental Health
Optimism
Resilience

There is compelling evidence suggesting that LGBTQ individuals face markedly higher rates of mood and anxiety disorder, as well as lifetime suicidality compared to heterosexual individuals. While most of the research on the psychological health of LGBTQ individuals has taken a deficit-based approach, more recent research has begun to explore the importance of resiliency in this population. Drawing on resilience theories, this study examined individual and community resources and stressors that contribute to the resiliency of LGBTQ individuals living in Canada and the United States and the degree to which these factors played a role in mitigating the adverse effects of mental health problems in LGBTQ individuals. Using multiple regression and mediation analysis, this study determined the predictability and mediation of model variables: internalized homophobia, coping skills (emotion-focused, problem-focused, and avoidant-focused), levels of optimism, attachment dimensions (anxious and avoidance), level of perceived social support, level of LGBTQ community connectedness, homonegative microaggressions, family acceptance, and overall psychological distress (depression, anxiety, and stress) on resilience. A total of 322 self-identified LGBTQ individuals were recruited through a variety of online venues. Results found optimism to be positive predictor of resilience and anxiety, depression, as well as anxious attachment dimension to be negative predictors of resilience. Further, higher levels of optimism, and lower levels of anxious and avoidance attachment related dimensions were all found to be significant partial mediators of the relationship between psychological distress and resilience. The results shed lights on ways mental health care professionals can promote resilience and mitigate the adverse effects of mental health in LGBTQ individuals.
Physiological Consequences of Sleep Loss in the Rat
Keywords: chronic sleep restriction
dark neuron
metabolism
sleep deprivation
sleep homeostasis
traumatic brain injury

In this thesis, I examined the homeostatic and physiological consequences of acute total sleep deprivation (TSD) and chronic sleep restriction (CSR) in the rat. I first developed a rat model of CSR using a walking wheel to confine sleep opportunities to designated times. I used this model to investigate the response of the sleep homeostat to a sleep deficit accumulated at different rates. I then compared the effects of CSR to the well-established acute ‘sleep deprivation syndrome’. Further, I considered a role for TSD in the production of reversible neuron damage. Finally, I investigated the impact of TSD and CSR on the integrity of neurons using an adapted model of mild traumatic brain injury (TBI). My research program led to the following conclusions: 1. CSR results in selective attenuation of the non-rapid eye movement (NREM) sleep homeostat, while leaving the rapid eye movement (REM) sleep homeostat intact. 2. CSR induces weight loss, body temperature and metabolic alterations that are qualitatively similar but quantitatively diminished compared to those of TSD. 3. TSD does not result in neuron damage in the rat sensorimotor cortex as measured by classical dark neurons (DNs). 4. Developing a sleep deficit from TSD or CSR prior to mild TBI does not cause exacerbation of neuron damage as measured by classical DN production. 5. There may be two under-represented demonstrations of neuron damage in the rat cortex: non-compacted DNs and light compacted neurons. When these neuron types are accounted for, a sleep deficit developed from TSD reduces the significant neuron damage produced by mild TBI. A sleep deficit developed by CSR does not afford the same neuroprotection as TSD.
Advanced application of BOLD fMRI to study cerebrovascular and neurovascular physiology in people with Cerebral Small Vessel Disease
Keywords: Blood oxygenation level dependent
Cerebral Pulsatility
Cerebral small vessel disease
Cerebrovascular reactivity
Functional magnetic resonance imaging
White matter hyperintensities

Cerebral Small Vessel Disease (CSVD) is one of the most common neurological disorders among older adults. Advances in neuroimaging have helped to identify the many structural changes seen in CSVD, of which lesions in the white matter, white matter hyperintensities (WMH), have been studied extensively. The CSVD literature scarcely addresses the relationship between structural changes and functional neurovascular and vascular outcomes. This thesis investigates blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) applications to better understand CSVD effects on cerebrovascular reactivity, functional activation, and brain tissue pulsatility. The first study of this thesis explores vasoactive capacity of people with a range of CSVD. I use a vascular transfer function to describe the extent to which and time taken for blood vessels to vasodilate in response to an external stimulus (i.e. CO2). The results demonstrated lower cerebrovascular reactivity in normal appearing white matter in those with more severe amounts of WMH, and further declined after one year in the CSVD population. The second study uses advanced BOLD fMRI image acquisition to observe neurovascular response through an attention-network probing task in CSVD. Widespread network activation in healthy older adults was altered in CSVD and healthy younger adults, and yet CSVD participants performed the poorest on the attention task. The third study investigates tissue-level cardiac-related pulsatility in the brain through repurposing of BOLD fMRI. These data revealed an association between insular pulsatility and middle cerebral artery pulsatility, the latter of which is an index of peripheral arterial stiffness and informs on possible mechanisms of CSVD cerebrovascular dysfunction. This thesis develops robust neuroimaging to show 1) functional deficits of CSVD, and 2) potential contributing factors to disease development. Establishment of functional outcomes is essential to understanding CSVD pathophysiology, the mechanisms behind its contribution to other neurodegenerative disorders, and the development of potential therapeutic targets.