30921 research outputs found
Sort by
The effects of critical historical knowledge and dibaajimowinan (storytelling) on reactions to missing and murdered Indigenous women, girls, two-spirit peoples+
No full textIndigenous women, girls, and 2SLGBTQI+ people in Canada experience disproportionately high rates of violence. In response, Indigenous communities have called for increased education and awareness to address the systemic causes of this violence. Critical historical education is one effective intervention. A complement to such education may be storytelling. In my thesis, I examined the effects of critical historical education and storytelling on non-Indigenous peoples’ emotional, attitudinal, and behavioral responses to this issue. I conducted an online experimental survey with non-Indigenous undergraduate students (N = 499) to compare these two approaches using a 2 (Critical Historical Knowledge: none, critical historical passage) × 2 (Storytelling: none, personal story video) factorial design. Participants in the three intervention conditions either read a critical historical passage, watched a video in which a woman described her lived experience, or received both interventions. Participants in a fourth empty control condition only completed the dependent measures of empathy, political solidarity, behavioral intentions, and support for government action. First, I hypothesized that all interventions would outperform the control in eliciting empathy, political solidarity, behavioral intentions, and support for government action. Second, I expected that the effect of each manipulation would be stronger in the presence of the other in eliciting empathy, political solidarity, behavioral intentions, and support for government action. Third, I hypothesized that participants who received one intervention would report similar levels of empathy, political solidarity, behavioral intentions, and support for government action. Finally, I expected that empathy or political solidarity would mediate the effects of the interventions on behavioral intentions. To test these hypotheses, I conducted factorial ANOVAs, pairwise comparisons, and mediation analyses. Both the critical historical passage and the personal story video increased empathy and support for government action. The critical historical passage also increased political solidarity and behavioral intentions. The interaction of both interventions was not significant for any variable. The critical historical passage indirectly increased behavioral intentions through increases in both empathy and political solidarity. Overall, either intervention positively influenced emotional, attitudinal, and behavioral responses. While acknowledging limitations, I discuss the implications of these findings for historical knowledge and story interventions.University of Manitoba
Carolynne Boivin Scholarship for Research in Family or Gender-Based ViolenceOctober 202
Medicalization of the private sphere: home care services in Manitoba
No full textWhile aging in place is often idealized as a way to maintain comfort, autonomy, and emotional connection, for many informal caregivers, the home becomes a medicalized space shaped by public home care services. Drawing on 13 semi-structured interviews and 6 home tours with live-in family/friend caregivers in Manitoba, this research explores how the integration of home care services into private residences affects caregivers’ perception of home, autonomy, and social roles. Through a process known as medicalization, this research questions the extent to which home care delivery transforms private homes into institutional environments, and family/friend caregivers into medical providers. This research also investigates the extension of the medical gaze into the home, with caregivers increasingly participating in medical surveillance. Within this framework, it is evident that home care services not only impact the recipient of care, but also, through medicalization and medicalized technologies, transform family/friend caregivers and domestic spaces into objects and agents of the medical gaze. It reveals how home care embeds mechanisms of surveillance and discipline into everyday life, and ultimately reshapes notions of responsibility, care, and the home space.October 202
Assessing the acute differential toxicity of polystyrene microplastic particles and comparing the impacts of bead-shaped versus fragmented particles on Daphnia magna
No full textThis study investigates polystyrene (PS) microplastics impact on the freshwater crustacean Daphnia magna, a sentinel species for environmental monitoring. Rather than utilizing their commercial microplastic counterparts, realistic microplastic morphologies that mimic those found in natural aquatic ecosystems were used to assess the hazard PS particles pose to aquatic organisms. A comprehensive suite of biological endpoints, including immobilization rates, generation of reactive oxygen species (ROS), expression levels of ROS-related genes and wide-ranging transcriptomic profiling, was encompassed in our methodology. This study, through these multifaceted experimental approaches, aimed to elucidate the detrimental effects of PS exposure on the early life stages of D. magna, i.e., neonates, with an emphasis on oxidative stress. The EC10 (effective concentration for 10% of the population) of ground PS (G-PS, fragments) was lower than that of purchased PS (C-PS, beads) in the immobilization test, resulting in the complete daphnid mortality. To advance the mechanistic understanding of microplastic-induced stress responses, a key goal was to integrate transcriptomic data with gene expression patterns. Daphnids exposed to PS fragments increased their oxidative stress response genes. However, in those exposed to PS beads, oxidative stress-related genes were not found in the top-10 expression of cellular components from the transcriptome. By illuminating the molecular responses induced by different shapes of microplastics in D. magna, the results of this research significantly expand the knowledge of microplastic impacts on aquatic ecosystem. We aim to provide insights into the ecological risks associated with microplastic pollution by understanding how varying shapes of microplastics affect this keystone species
Privacy-aware distributed machine learning
No full textSplit Learning (SL) is a promising framework for distributed machine learning in resource-constrained and privacy-sensitive settings. However, vanilla SL deployments have limitations in communication overhead, privacy leakage from intermediate activations, accommodating heterogeneous client capabilities, and integrating with federated strategies. This thesis addresses these challenges through four primary contributions. First, we address communication efficiency by proposing a Vector Quantized Variational Autoencoder (VQ-VAE) framework using Lookup-Free Quantization (LFQ) for compressing intermediate features. This eliminates the need for codebook transmission, with favorable rate-distortion trade-offs. Second, we introduce PRISM (Privacy Router with Integrated Spatio-Channel Masking), an information router and optimization strategy for enhancing privacy in SL. PRISM adopts a U-shaped network, fine-grained masking, a local bypass stream, and disentangled optimization to reduce information leakage to the server while preserving task utility. Third, we propose Split Learning with Frozen Clients (SL-FC), a strategy designed for heterogeneous environments. SL-FC studies how ultra-resource-constrained ``frozen" clients, capable only of forward propagation, can contribute their data to server-side training, demonstrably improving overall model performance. Finally, we evaluate the Muon optimizer for use as an outer-loop, or federated optimizer. Muon orthogonalizes momentum updates, aiming to improve convergence speed and stability compared to standard federated optimizers like FedAvgM and FedAdam. This thesis provides theoretical analyses, rate-distortion bounds, convergence guarantees, and empirical evaluations to demonstrate the effectiveness of the proposed methods. Tasks involve image classification, segmentation and model training under non-IID constraints. Collectively, these contributions improve the practicality, and privacy over existing split and federated learning systems.October 202
Manitoba connected: using MSNA-ID data to review social connections of people living with an intellectual disability
No full textLoneliness is prevalent amongst people living with an intellectual disability (ID) and can lead to quality-of-life and health concerns. The goal of this study was to explore the structural and functional characteristics of social networks of people living with an ID in Manitoba, Canada. Data collected using the Maastricht Social Network Analysis for People with Intellectual Disability (MSNA-ID) were examined from 159 participants supported by St.Amant between 2020-2022. Participants averaged 11 relationships (M = 11, SD = 7.58, range 1 - 49), with anchor relationships generally rated highest across functional characteristics of affection (M = 4.41 out of 5), connection (M = 3.23), preference (M = 4.42), and resources (M = 3.63). Despite 57.6% reporting general satisfaction with their network, 30.2% of “step-up” wishes for network improvement mentioned opportunities to increase social connections. Exploring and understanding the social connections that people living with an ID currently have, as well as their satisfaction within those relationships, may help us to promote meaningful connections for this population.October 202
Critical literacies and diverse epistemologies in librarian teaching
No full textWithin a theoretical framework of critical literacy, critical pedagogy, and diverse epistemologies, oriented by decolonizing approaches to the same, the research described in this dissertation explored how critical literacies and diverse epistemologies are enacted and incorporated into librarian teaching at the University of Manitoba. Questions framing this research centered on how librarians talk about their teaching, what those conversations illustrate about how librarian teaching is conceptualized, and how these conversations can propel librarians, librarianship, and our educational systems into more equitable and inclusive futures for post-secondary educators and learners. In semi-structured interviews, ten University of Manitoba librarians, for whom teaching was part of their professional practice, discussed nuanced ideas and conceptualizations which were analyzed through three levels of impact for practitioners across post-secondary education: the individual, the professional, and the institutional. The data generated from this study recounts that librarians think deeply and intentionally about their teaching on personal levels, in relation to their professional inheritance, and educational systems broadly, with an eye to how their pedagogical approaches can create change in historically exclusionary systems of education. Although the data showed there are several systemically derived barriers which can hinder critical literacies, critical pedagogy, and diverse epistemologies in librarian teaching, there is also evidence librarians are willing and eager to evolve their teaching practices, spur change within the profession, and contribute to institutional efforts to foster more diverse, inclusive, and equitable post-secondary education.University of Manitoba Faculty of Education Graduate Student Research Award
University of Manitoba Librarians, Archivists, and Librarian Interns Travel/Education FundOctober 202
Unsupervised clustering for sepsis identification in large-scale patient data: a model development and validation study
Get PDFAbstract Background Sepsis is a major global health problem. However, it lacks a true reference standard for case identification, complicating epidemiologic surveillance. Consensus definitions have changed multiple times, clinicians struggle to identify sepsis at the bedside, and differing identification algorithms generate wide variation in incidence rates. The two current identification approaches use codes from administrative data, or electronic health record (EHR)-based algorithms such as the Center for Disease Control Adult Sepsis Event (ASE); both have limitations. Here our primary purpose is to report initial steps in developing a novel approach to identifying sepsis using unsupervised clustering methods. Secondarily, we report preliminary analysis of resulting clusters, using identification by ASE criteria as a familiar comparator. Methods This retrospective cohort study used hospital administrative and EHR data on adults admitted to intensive care units (ICUs) at five Canadian medical centres (2015–2017), with split development and validation cohorts. After preprocessing 592 variables (demographics, encounter characteristics, diagnoses, medications, laboratory tests, and clinical management) and applying data reduction, we presented 55 principal components to eight different clustering algorithms. An automated elbow method determined the optimal number of clusters, and the optimal algorithm was selected based on clustering metrics for consistency, separation, distribution and stability. Cluster membership in the validation cohort was assigned using an XGBoost model trained to predict cluster membership in the development cohort. For cluster analysis, we prospectively subdivided clusters by their fractions meeting ASE criteria (≥ 50% ASE-majority clusters vs. ASE-minority clusters), and compared their characteristics. Results There were 3660 patients in the development cohort and 3012 in the validation cohort, of which 21.5% (development) and 19.1% (validation) were ASE (+). The Robust and Sparse K-means Clustering (RSKC) method performed best. In the development cohort, it identified 48 clusters of hospitalizations; 11 ASE-majority clusters contained 22.4% of all patients but 77.8% of all ASE (+) patients. 34.9% of the 209 ASE (−) patients in the ASE-majority clusters met more liberal ASE criteria for sepsis. Findings were consistent in the validation cohort. Conclusions Unsupervised clustering applied to diverse, large-scale medical data offers a promising approach to the identification of sepsis phenotypes for epidemiological surveillance
Elucidating novel function(s) of prolactin inducible protein in regulating natural killer (NK) cell biology
Get PDFProlactin-inducible protein (PIP) is found in various bodily fluids, including tears, saliva, sweat, amniotic fluid, and seminal plasma. This protein is frequently associated with breast cancers (BCs) and serves as a biomarker for identifying the origin of BC. Its presence has been linked to favorable prognostic outcomes in human BC. In a 4T1 breast cancer mouse model, ectopic expression of PIP led to an increased frequency of natural killer (NK) cells and dendritic cells within the tumor microenvironment, resulting in delayed tumor onset and reduced growth. While previous research has associated PIP with immune response regulation, the specific mechanisms by which PIP modulates NK cell biology remain unclear.
I hypothesized that PIP acts as a novel host factor influencing NK cell functionality. To investigate this, I examined its role in regulating NK cell migration, cytotoxicity, and cytokine production.
To assess PIP’s impact on NK cell migration, a transwell migration assay was conducted. NK cells showed significantly enhanced migration toward conditioned media from PIP-expressing 4T1 cells compared to empty vector (EV) controls. Additionally, recombinant mouse PIP (mPIP) at a concentration of 1µg/600ul significantly induced NK cell migration compared to BSA. Treatment of NK cells with PIP also resulted in significant phosphorylation of p38 MAPK and IκBα, suggesting a potential mechanism for PIP’s regulation of NK cell migration.
However, the expression of PIP did not affect NK cell-mediated killing or interferon-gamma (IFN-γ) production in response to parental, breast-derived, and lung-metastatic 4T1 cells in vitro.
In summary, these findings demonstrate that PIP promotes NK cell migration but does not directly influence NK cell-mediated cytotoxicity or cytokine production in vitro. This study provides novel insights into PIP’s role in enhancing NK cell migration, contributing to a better understanding of its involvement in immune regulation.RFHS Graduate StudentshipMay 202
Biomimetic vibroprobes for lunar and terrestrial subsurface exploration
Get PDFSpace exploration presents challenges, particularly in adapting soil drilling tools for efficient subsurface investigation of the Moon and other extraterrestrial bodies. Traditional tools used on Earth are impractical due to payload restrictions in space missions. To address this issue, the development of light and compact probes is essential for overcoming payload barriers. This research focuses on the development of two concepts for subsurface investigation tools: 1) the utilization of subsonic projectile probes, which can be launched from a lunar orbiter or lander to the surface of the Moon, and 2) bio-inspired vibroprobes, which can be mounted on a lunar rover. As such, in the first part of this thesis, an analytical
model is developed to predict the deceleration rate and final penetration depth of a rigid projectile probe under perpendicular subsonic impact. The analytical model, developed based on the spherical cavity expansion theory, considers plastic and elastic stress fields by incorporating the Mohr–Coulomb failure criterion. The proposed solutions in the subsonic range have been validated using field ground-based experimental data found in the literature. This validation confirms the model’s reliability in estimating the dynamic motion of the penetrator and highlights its potential as a benchmark for more complex, sophisticated numerical calculations.
The second part of this thesis involves the development of a biomimetic vibro-based probe, which deploys energy-efficient high-power vibrations to enhance penetration into granular materials. This is carried out by drawing inspiration from observed bending vibrations in biological mechanisms such as snakes, horned lizards, and sandfish. First, the influence of vibration frequency, amplitude, and probe head on penetration resistance is assessed computationally using the discrete element method. The simulation outcomes suggest that high-frequency lateral vibrations hold promise in decreasing the required overhead load for the penetration of probes into granular media. Then, the impact of lateral vibration is physically investigated by developing proof-of-concept bio-inspired vibroprobes in the laboratory. The probes are equipped with thin piezo patches to induce lateral vibration, manifesting as bending vibrations in the structure of the probes. Through experimental testing, the capability of the vibroprobes to reduce penetration force and enhance the penetration process into granular materials is assessed. The experimental results demonstrated a significant reduction in penetration force, reaching up to 42%, when employing bi-directional bending vibrations in the circular cross-section probe. This highlights the effectiveness of bending vibration in developing compact subsurface drilling tools.
These two concepts provide a promising strategy for overcoming soil drilling challenges in remote subsurface investigations.May 202
Maternal resveratrol supplementation and its effects on cardiac hypertrophy, mitochondrial metabolism, and calcium flux in isolated fetal cardiomyocytes
Get PDFGestational diabetes mellitus (GDM) is a condition that manifests in pregnancy that is characterized by insulin resistance, glucose intolerance, and hyperglycemia. Medications have shown effectiveness but have associated risk of adverse pregnancy outcomes. Our previous studies in rats found cardiomyocytes of GDM-offspring exhibit hypertrophy, mitochondrial dysfunction, and impaired calcium flux. We hypothesize that administration of resveratrol (RESV) to maternal GDM diet will mitigate mitochondrial dysfunction, cardiac hypertrophy and improve calcium flux in GDM-offspring. A diet-induced model was implemented on female Sprague-Dawley rats six weeks before mating to induce GDM. A subgroup of GDM dams were switched to a diet containing RESV. Fetal echocardiography was performed to assess cardiac structure. Measurements of mitochondrial respiration and calcium flux were performed using the Agilent-Seahorse XF 24 and Cytation 5. Maternal RESV supplementation improved mitochondrial respiration and improved calcium flux upon angiotensin II stimulation. Importantly, maternal RESV supplementation attenuated GDM-induced cardiac hypertrophy in GDM-offspring.May 202