30921 research outputs found
Sort by
Elaborative processing and recognition memory
No full textIn this dissertation, I present a comprehensive account of elaborative processing grounded in instance theory. My aim is to demonstrate that a variety of memory effects can be traced back to the same underlying mechanism: elaborative processing. The central focus of this research is the production effect, though the approach is also extended to two other well-established phenomena—the generation effect and the testing effect. In addition, I present a parallel investigation involving the production effect and directed forgetting. To achieve my aim, I conducted both experimental and computational analyses of these effects within the context of recognition. Building on the MINERVA 2 model, I introduced novel extensions to apply it to the production, generation, and testing effects. The overarching goal of this thesis is to demonstrate that these memory effects can be explained by two principles of memory, strength and distinctiveness, advancing our understanding of elaborative processing. This work will contribute to a deeper insight into the production effect and will enhance existing models of memory processing.February 202
Analysis and design of metasurfaces for beamforming, imaging, and novel applications
No full textAn electromagnetic metasurface is a thin, surface-like engineered structure that allows for the systematic scattering and transformation of incident electromagnetic waves. Through the careful design of its subwavelength scattering elements known as meta-atoms or unit cells, the metasurface can tailor, scatter, or generate electromagnetic waves as needed. Due to the ever-growing complexity of the metasurface and its applications, there is an equally growing need for novel ideas, theory, algorithms and other tools with the goal of facilitating the analysis and design of advanced metasurface structures. To address some of these needs, this thesis presents a collection of such tools with a focus on beamforming, imaging, and novel applications. A common theme of each application is a reliance on the field integral equations and the clever leveraging of their properties. This provides a significant degree of versatility and efficiency to the algorithms and tools developed for this thesis.
We begin by considering the fast and efficient analysis of metasurface problems, i.e., the fast and efficient computation or simulation of the scattered fields in metasurface problems. A novel metasurface forward solver known as the implicit IE-GSTC is developed that can simulate many different metasurface problems in an efficient manner that matches or exceeds other similar solvers. We next consider the development and improvement of metasurface design methods for beamforming. In one chapter, we examine and refine the application of regularization terms used to ensure physically consistent designs for an advanced algorithm known as inverse metasurface design. In a subsequent chapter, we develop two novel design algorithms that enable energy-efficient metasurface structures through the use of cascaded metasurface pairs or the excitation of surface waves. Finally, we also consider the incorporation of exotic degrees of freedom into the metasurface structure, which take the form of spatiotemporal modulation and non-locality. The spatiotemporal modulation is used to conceptualize metasurface enclosures that are useful for microwave imaging purposes. Conversely, we use non-locality to perform the conceptual design of metasurfaces that can perform analog computations on the fields. Lastly, we explore the synthesis of effective non-local metasurface structures through otherwise local structures.February 202
Shareholder proposal in Canada: questions, concerns and opportunities for improvement
No full textShareholder proposals are a consistent and prevailing issue that often pose questions and concerns, and room should be provided for improvement. This concept is pertinent as it has been a recurring problem that has inhibited the growth of good corporate governance practice in Canada. This thesis explores the landscape of shareholder proposals in Canada, highlighting key improvements. Shareholder proposals serve as a vital mechanism for investors to influence corporate governance and strategic direction. However, the current legal framework in Canada also presents challenges, including limited access for minority shareholders, inadequate disclosure practices, and the potential to dismiss proposals without sufficient consideration. This thesis aims to identify these issues while examining the regulatory environment and its implications for shareholder engagement. Furthermore, it will propose actionable recommendations to enhance the effectiveness and inclusivity of the proposal process, ultimately fostering a more transparent and accountable corporate governance system in Canada. By addressing these concerns, this thesis seeks to proffer ways to empower shareholders and improve the overall health of the Canadian capital market.David T. Sgayias Graduate FellowshipOctober 202
Preliminary validation of a novel genetic knowledge scale for familial hypercholesterolemia: evaluation of face validity and core concepts
No full textThe Multidimensional Model of Informed Choice (MMIC) was developed to evaluate informed decision making in the context of genetic testing. A need has been identified for validated MMIC measures specific to inherited cardiac conditions, including familial hypercholesterolemia (FH). FH is a common genetic condition that can cause premature atherosclerotic cardiovascular disease (ASCVD) if left untreated.
The primary aim of this study was to initiate the validation of an 8-item knowledge scale specific to FH. The secondary aim of this study was to explore the key factors that influenced how participants decisions about genetic testing for FH. Once validated, this knowledge scale can be used as part of an MMIC measure to evaluate patient informed choice in the context of genetic testing for this condition.
This study used semi-structured cognitive interviews (N = 10) paired with a traffic light coding system was used to assess the face validity of the items in the knowledge scale, along with the importance of their associated concepts. Conventional content analysis of the interviews was used to identify the key factors that influenced participants’ decision regarding genetic testing for FH.
The items in the knowledge scale were interpreted correctly by all participants. Minor revisions were made based on participant feedback to improve the clarity of six items. Most participants (n = 9) considered the concepts covered by the knowledge scale to be either helpful or necessary to decide about genetic testing for FH. Conventional content analysis revealed three common motivations to pursue genetic testing which include family, insight into medical management, and the opportunity for patient empowerment. Importantly, participant responses highlighted a lack of awareness of genetic services among this patient population, along with the positive impact genetic counselling can have for those who are offered genetic testing for FH.
The development and validation of a FH-specific MMIC measure aims to be used in research targeted at maximizing informed choice among this patient population. Additionally, we foresee that these findings will serve to highlight the importance of genetic testing among this patient population and inform appropriate pre-test counselling for this condition.October 202
Green equity: designing heat resilient urban spaces in Delhi
No full textDelhi, the capital of India, is becoming increasingly hot due to the rising urban temperatures. In recent years, summer temperatures have soared beyond 49°C, with the urban area’s average temperatures atleast 6°C higher than its rural surroundings. Rapid urbanization, deforestation, the loss of water bodies, and a rapid reduction in green spaces have all contributed to this unbearable heat. But this heat does not affect everyone equally. Low-income communities - often living in the densely packed, poorly ventilated neighborhoods with minimal tree cover—suffer disproportionately from these rising urban temperatures. Their limited access to natural cooling areas further compounds their vulnerability.
This practicum investigates how landscape architecture can serve as a critical tool in mitigating Delhi’s rising urban heat. Through spatial analysis, climate data, and design exploration, the practicum addresses the intermingled layers of climate change, social inequity, and environmental degradation.
By analyzing global precedents and conducting a GIS-based heat vulnerability mapping, the practicum identifies neighborhoods most at risk. From this foundation, the practicum develops a multi-scalar urban cooling strategy, deeply rooted in the principles of urban forestry. The design process further concludes in a detailed cooling framework for Bhajanpura, Shahadra, a site characterized by high population density and severe heat stress, where proposed landscape based interventions reintroduce shade, ecological cooling, and communal access these cooling public spaces.
Finally, this practicum offers a scalable framework for designing equitable and heat resilient public spaces, in the face of rising temperatures. It presents a multi-scale approach, incorporating a variety of strategies for urban cooling that can be adapted to different contexts and scales of intervention.October 202
Integrative exploration of taste genetics, oral microbiome, and socioeconomic factors in early childhood caries
No full textEarly childhood caries (ECC) refers to dental cavities or decay in children less than 72 months of age. Nearly half of the children are affected by ECC globally, which can reach up to 98% in some disadvantaged communities. ECC is multifactorial in nature, with various etiological factors, including the microbiome, socioeconomic factors (SEF), and host genetics. Among host genetic factors, taste receptors are crucial as they modulate host taste preference and may also play a role in interactions with microbial species through innate immune responses. To address whether host genetics can influence oral microbes, this study investigated the association of taste receptors with ECC and the dental plaque microbiome. Furthermore, we explored the role of various SEF in ECC and their impact on the oral microbiome. We also assessed interkingdom associations through species co-occurrence.
For this analysis, data were collected from children’s parents or caregivers for socioeconomic and behavioral information, along with dental plaque and buccal swab samples for microbiome and 55 taste-related gene sequencing, respectively. Sequencing was performed using next-generation sequencing, with data analyzed using QIIME2 for microbiome and GATK pipelines for variants in taste-related genes. Various analytical, statistical, and machine learning tools in R were employed for the analysis.
Our results indicate that SEF, specifically the Socioeconomic Factor Index (SEFI) and rural-urban status, are highly associated with ECC status. We found a strong correlation between the fungal species Candida dubliniensis and the bacteria Neisseria bacilliformis in ECC. Through integrative machine learning-based prediction of ECC, the bacterial species Streptococcus mutans and the fungi Candida dubliniensis, a bitter taste receptor variant TAS2R60-rs35195910, along with SEFI and rural-urban status, emerged as top markers. We also evaluated the generalizability of machine learning based ECC prediction using previously published ECC microbiome studies.
In conclusion, we identified microbial markers that are highly associated with ECC and the potential interactions among them. Although taste genetic markers did not influence ECC-associated microbial species, they were associated with other species in the dental plaque microbiome. Lastly, due to the complex role of multiple factors, we recommend integrating multiomics data analysis in future ECC-related studies. These findings help us understand the etiological landscape of ECC and identify susceptible individuals, enabling personalized therapeutic approaches and preventative strategies.October 202
Evaluating the impact of the Skills for Living program on quality of life and emotional intelligence in adults with autism
No full textAutism Spectrum Disorder (ASD) poses challenges for social communication, interaction, and overall well-being. In Canada, many adults with ASD do not receive support services, leading to difficulties in their everyday lives, especially during the transition to adulthood. Emotional intelligence reflects emotional and social skills as well as the characteristics that allow us to navigate social-emotional situations. As a result, emotional intelligence it is vital for effective social interactions and well-being. Individuals with ASD often struggle with emotional intelligence, affecting their employment, mental health, and their overall quality of life. Emotional intelligence can be taught (Kotsou et al., 2018), but has rarely been directly investigated in ASD, despite its promise for directly addressing core difficulties of people with autism. This study evaluated the Skills for Living program's effectiveness in enhancing emotional intelligence and quality of life for adults with ASD who do not have an accompanying intellectual disability.
Participants were recruited from Asperger Manitoba Inc. and Level IT Up, and online advertisements. screened for suitability, and underwent pre-program assessments, including the Autism Quotient (AQ), Emotional Quotient Inventory 2.0 (EQ-i 2.0), and Quality of Life Inventory (QOLI). The program involves 10 group sessions. Participants completed an assessment of emotional intelligence and quality of life at three time points (pre, post, and maintenance). Change in scores was evaluated using within-group paired samples t-tests and effect size calculations.University of Manitoba (UMGF), Psychology Graduate Fellowship, Asperger Manitoba and Level IT Up in partnership with MITACS, James Gordon Fletcher Graduate Research Award in Arts.October 202
The effects of inclusive victimhood narratives on support for reconciliation in Canada
No full textGroups seeking justice are often more successful when they have support from other groups. In Canada, where only 5% of people are Indigenous, non-Indigenous support can help make progress toward reconciliation. In this thesis, I investigated whether an inclusive victimhood narrative increased solidarity with Indigenous peoples and support for reconciliation, and whether emotions explained these effects. In an online survey, I manipulated whether non-Indigenous students who were Canadian citizens or permanent residents (N = 481) viewed an inclusive victimhood narrative—a brief passage which asked participants to consider whether members of different harmed groups might have similar experiences of discrimination, prejudice, and stereotyping—and rated their perceptions of these similarities. Participants then read a passage describing how residential schools in Canada harmed Indigenous peoples and that many are calling for reconciliation to improve the relationship between Indigenous and non-Indigenous peoples. After, participants reported how they felt when thinking about reconciliation (i.e., love, empathy, anger, sadness, sorry, and hope) and completed measures of solidarity, behavioral intentions, behavioral intentions effort, and their attitude toward reconciliation. The inclusive victimhood narrative caused participants to agree more that reconciliation is needed but had no effect on any other variables; however, further structural equation modeling exploratory analyses within only the inclusive victimhood condition (n = 222) indicated that measured inclusive victimhood had an indirect effect on both behavioral intentions and attitudes, through both positive and negative emotions and then solidarity. Thus, inclusive victimhood narratives may be relevant in garnering support for social change.University of ManitobaOctober 202
Strength of early-age concrete masonry prism short-term exposed to freezing temperatures
No full textConcrete masonry is extensively utilized in Canada due to its superior compressive strength, aesthetic versatility, cost-effectiveness, ease of construction, and proven durability. However, akin to other construction materials, concrete masonry exhibits high sensitivity to temperature variations during construction, curing, and mature stages. The majority of extant research has concentrated on the influence of temperature on mature masonry structures (beyond 28-day curing), investigating the mechanical behavior of fully cured assemblies under freezing conditions. This focus has resulted in a notable knowledge gap concerning the effects of freezing temperatures on early-age masonry. Prevailing masonry construction guidelines advocate maintaining temperatures above 4.44°C to mitigate mortar freezing and grout expansion, often necessitating thermal insulation or protective measures during low-temperature construction. Nonetheless, these guidelines overlook two pivotal uncontrollable factors during the construction phase: unpredictable weather exposure and potential failures in structural protection against freezing temperatures. The mechanical performance of early-age masonry subjected to unintentional or accidental short-term exposure to freezing temperatures remains inadequately explored, leaving uncertainty regarding its impact on structural capacity. To address these deficiencies, 324 specimens were tested under diverse temperature regimes and exposure durations to assess their compressive and tensile strengths. The experimental outcomes delineate a multifaceted pattern: freezing temperatures can augment strength development in ungrouted and grouted compression specimens, as well as grouted tension specimens. Specifically, ungrouted compression specimens exposed to -6°C surpassed the CSA compressive strength design requirement by an average of 46.98\% and exceeded the control group strength by 28.66\%. Grouted compression specimens at -6°C exhibited 9.88\% higher strength than the CSA standard and 12.64\% higher than the control group. Ungrouted compression specimens at -12°C exceeded the CSA standard by 39.38\% and were 23.49\% stronger than the control group, while grouted counterparts were 1.94\% above the standard and 4.19\% above the control. At -24°C, ungrouted compression specimens were 17.99\% higher than the CSA requirement and 3.32\% higher than the control, whereas grouted specimens at this temperature demonstrated adverse effects, yielding compressive strengths 4.91\% and 3.16\% lower than the CSA standard and control group, respectively. Furthermore, freezing temperatures exerted pronounced detrimental effects on ungrouted tension specimens across all temperature levels, resulting in an average tensile strength reduction of 86\% relative to the CSA design requirement. In comparison to the control group, however, -6°C ungrouted tension specimens exhibited 1.82\% higher tensile strength, -12°C specimens were 5.32\% higher, and -24°C specimens were 5.67\% higher. For grouted tension specimens, those at -6°C were 41.03\% above the CSA tensile strength requirement but 25.59\% below the control group. The -12°C grouted tension group demonstrated 95.95\% higher strength than the CSA standard yet remained 7.18\% below the control. Notably, -24°C grouted tension specimens performed optimally, achieving 141.48\% higher tensile strength than the CSA requirement and 19.42\% higher than the control. These findings quantitatively elucidate the ramifications of freezing temperatures on nascent masonry assemblies, offering valuable insights for enhancing quality control in masonry construction under adverse conditions. Moreover, solely mitigating cold temperatures should not constitute the exclusive strategy, as the beneficial effects of freezing have been substantiated in this and prior investigations. Instead, greater integration of cold-weather considerations during design and construction processes should be pursued to optimize masonry quality and reliability.Canadian Concrete Masonry Producers AssociationOctober 202
Keepers of the land, in whose hands? Community responses to hydroelectrical dams in Northern Manitoba
No full textThis research project was an opportunity to give context to hydroelectric development impacts in the light of sovereign community responses. The communities of focus were Tataskweyak Cree Nation (TCN) and O-Pipon-Na-Piwin Cree Nation (OPCN). The impacts of hydro-development have been vast to both the environment and the people, particularly impacting cultural land practices and hence the identity of a people. Members of both communities have shared historical, community, and personal accounts of these impacts, in a bid to have a complete narrative of the impacts of hydroelectric development on a way of life. Various case studies of community responses to these impacts have been featured to showcase the resilience of a people. Particularly to show the ways in which actions of sovereignty are actions to reinstate identity in the face of these impacts.
This thesis was a collaborative research effort with members of Tataskweyak Cree Nation and O-Pipon-Na-Piwin Cree Nation directing the weight and application of themes within this research. The research aimed to highlight the long-standing social impacts of hydro as well as the various aspects of sovereignty used in responding to these impacts. This research used qualitative research methods, specifically narrative analysis, storytelling, thematic analysis, and discourse analysis, to achieve the research goals. Along with interviews from Knowledge Keepers, Land Users, and Elders, this research also carried out an analysis of archival records from the Clean Environment Commission and other sources.
According to OPCN and TCN members, hydroelectric development impacts have often focused on the impacts to the land and water, leaving out the impacts on culture and ways of being. These environmental impacts have often overshadowed the social impacts that are key to the well-being of the featured Cree communities and their cultures. It is hoped that this thesis will broaden the understanding of the socioeconomic impacts of hydro development within the context of culture, practice, and identity, while highlighting sovereign community responses.October 202