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Release the Furies!: victim impact statements expose the social impacts of murder
Get PDFThis study explores the victim impact statements (VIS) by family members of murder victims, utilizing a multi-perspectival adaptation to hermeneutical phenomenology. Three distinct readings of 78 statements highlight the ways in which murder is experienced at the individual, familial, and societal level. The use of this novel tri-layered hermeneutical method draws out important nuance and differences when read in the context of an abstract individual versus that person as the mother, sister or son of a murder victim. Additional insight drawn into the hermeneutic circle from historical contextual factors, such as colonization or gang involvement further delineates the experiences within these narratives. The research was guided by questions of what is being said in VIS and what VIS authors might tell us about murder as a phenomenon. The narratives reveal critical insights into the way murder operates and discriminates in this Canadian prairie urban environment in which 18% of the population, yet fifty percent of homicide victims, are Indigenous. In the first study of this kind, that examines Indigenous and non-Indigenous VIS, existing perspectives about the impacts of murder are questioned. Replacing an individualistic trauma lens with a wider social lens highlights how the crime of murder, and the societal responses to it, are rooted in colonialist legal and social perspectives that result in revictimization of these families. The findings also identify the disproportionate burden of murder on women, exposing discriminatory policies within victim and family services with broader implications across Canada. Greater still, this research uncovers an interesting pattern in the way VIS are written that overcomes the instrumental/expressive debate with an agentic model of VIS, leading into theoretical territory beyond Canadian borders. The agency and ritual-like process undertaken by these VIS authors attests to the powerful role of emotion in justice and offers a new perspective that transforms the authors from bereaved victims into empowered citizens demanding acknowledgement as parties wronged by crime. Through this paradigm shift we might finally move away from the pathologized-victim lens to one that acknowledges the agency of victims’ kin in their role as primary stakeholders in this crime.October 202
The association between the Healthy Baby program and postpartum depression among birthing parents in Manitoba: a retrospective cohort study
Get PDFBackground: Postpartum depression (PPD) affects about 10-20% of birthing parents and low-income birthing parents are at high risk. It is important to address PPD due to the associated negative outcomes for both birthing parent and child. The Manitoba Healthy Baby (HB) program has two components: Prenatal Benefit (HBPB) and Community Support Programs (HBCSP) aiming to promote perinatal health. While there is evidence indicating that the HB program improves birth and perinatal outcomes, the impact on the birthing parents’ mental health is yet to be examined.
Objective: This study aimed to estimate the effect of participation in the two components of the HB program on the incidence of PPD among low-income birthing parents in Manitoba.
Methods: Using the de-identified, linkable routinely collected data in the Population Research Data Repository housed at the Manitoba Centre for Health Policy (MCHP), all low-income birthing parents who had singleton, vaginal, full-term, live birth of their first child in Manitoba between April 1, 2004, to March 31, 2019, were included (n = 3,561). Generalized Linear Models with Inverse Probability Treatment Weights were used to assess the relative difference in the associated risk of having a PPD diagnosis between exposure groups. Sensitivity to unmeasured confounding was estimated using E-value.
Discussion: Both receipt of the HBPB and prenatal attendance in the HBCSP alone were associated with an increased likelihood of PPD. However, the combination of the two components did not yield statistically significant results, and the association of HBCSP attendance with PPD was only found for rural areas. Although findings may be interpreted as the program causing harm, the more likely explanation is the higher risk profile of those participating in the program and/or the program’s effectiveness in connecting birthing parents to professional help. This study highlights the importance of connecting birthing parents with their primary care provider as it can determine receipt of PPD diagnosis and care. Efforts should be increased to improve the HB program’s reach toward birthing parents who may be at risk for depression to be able to address PPD among this population as well as its associated negative outcomes.University of Manitoba Tri-Agency Top-Up Award and Tri-Council Supplemental Master’s Award; Manitoba Training Program for Health Services Research Studentship; Graduate Enhancement of Tri-Council Stipends (GETS); Research Manitoba-Children’s Hospital Research Institute of Manitoba (CHRIM) Master’s Studentship Award; Manitoba Family Year 1994 Legacy Scholarship; Evelyn Shapiro Award for Health Services Research; and University of Manitoba Faculty of Graduate Studies Research Completion Scholarship.October 202
Leveraging large-scale datasets and single cell omics data to develop a polygenic score for cisplatin-induced ototoxicity
Get PDFAbstract Background Cisplatin-induced ototoxicity (CIO), characterized by irreversible and progressive bilateral hearing loss, is a prevalent adverse effect of cisplatin chemotherapy. Alongside clinical risk factors, genetic variants contribute to CIO and genome-wide association studies (GWAS) have highlighted the polygenicity of this adverse drug reaction. Polygenic scores (PGS), which integrate information from multiple genetic variants across the genome, offer a promising tool for the identification of individuals who are at higher risk for CIO. Integrating large-scale hearing loss GWAS data with single cell omics data holds potential to overcome limitations related to small sample sizes associated with CIO studies, enabling the creation of PGSs to predict CIO risk. Results We utilized a large-scale hearing loss GWAS and murine inner ear single nuclei RNA-sequencing (snRNA-seq) data to develop two polygenic scores: a hearing loss PGS (PGSHL) and a biologically informed PGS for CIO (PGSCIO). The PGSCIO included only variants which mapped to genes that were differentially expressed within cochlear cells that showed differential abundance in the murine snRNA-seq data post-cisplatin treatment. Evaluation of the association of these PGSs with CIO in our target CIO cohort revealed that PGSCIO demonstrated superior performance (P = 5.54 × 10− 5) relative to PGSHL (P = 2.93 × 10− 3). PGSCIO was also associated with CIO in our test cohort (P = 0.04), while the PGSHL did not show a significant association with CIO (P = 0.52). Conclusion This study developed the first PGS for CIO using a large-scale hearing loss dataset and a biologically informed filter generated from cisplatin-treated murine inner ear snRNA-seq data. This innovative approach offers new avenues for developing PGSs for pharmacogenomic traits, which could contribute to the implementation of tailored therapeutic interventions. Further, our approach facilitated the identification of specific cochlear cells that may play critical roles in CIO. These novel insights will guide future research aimed at developing targeted therapeutic strategies to prevent CIO
Bayesian inference on baseball batting metrics using Nested Dirichlet Multinomial models
Get PDFBayesian methods and sports analytics have become popular areas of research, but their intersection remains under-considered in Statistics. While the Nested Dirichlet distribution has been proposed as a conjugate prior to Multinomial data commonly produced in sports settings, many properties of this distribution and its generalizability have not been explored. In this thesis, we propose a different parameterization for the Nested Dirichlet distribution and explain how it can be used to derive the posterior and posterior predictive distributions for the Nested Dirichlet Multinomial model. We also demonstrate the generalizability of our parameterization, an important improvement over the approaches that can be found in the literature. Finally, we present how we used this model to analyze 2023 MLB batting outcome data to produce model-based batting metrics with appropriate uncertainty quantification and compare the results to those produced by the traditional Dirichlet Multinomial model. We found that each model works well under different circumstances, leading us to suggest methods for their improvement in future research. For example, creating mixture models to best capture different player abilities and styles, amongst other suggestions.University of Manitoba (Department of Science), Supervisors (Dr. Alexandre Leblanc and Dr. Saman Muthukumarana)October 202
Investigating cascaded metasurface pairs with internal sources for beam shaping and matching
Get PDFElectromagnetic metasurfaces are electrically thin structures with small inclusions that allow for electromagnetic wave manipulation beyond the capabilities of conventional thin materials. Using the often desired passivity and losslessness attributes, single metasurfaces fail to provide certain electromagnetic wave transformations. To handle this, cascaded metasurface systems, consisting of two separated metasurfaces, are considered to overcome the power conservation limitations created by these attributes.
This thesis focuses on the design optimization and validation of electromagnetic cascaded metasurfaces with internal sources, with an exploration of many different use cases. It starts with an overview of the conceptual framework that guides the entire process with a methodology overview. It covers the topic of metasurfaces in general, starting from a qualitative introduction to metamaterials, their historical context, and evolution, before advancing to a quantitative examination that includes the mathematical formulations and theoretical underpinnings. This part of the thesis establishes a foundation for metasurfaces in general before transitioning into the core of the thesis.
The core of the thesis casts the design variables, originally formulated in an earlier work, in the forms of matrices and vectors, and then optimizes a design cost functional through the nonlinear conjugate gradient (CG) scheme. This CG scheme is also adapted to a more affordable system where one of the metasurfaces is replaced by a simple metallic sheet. The optimization scheme is considered in both complex and real domains to show the equivalency of optimization in both domains.
The results chapter presents an analysis of various setups and simulations for cascaded metasurfaces with an internal source for beam shaping and matching scenarios. This draws comparisons between the nonlinear CG method and previously implemented gradient descent approaches. It explores different user-defined specifications, showcasing the practicality and effectiveness of analytical techniques, antenna array approaches, and far-field masks. This is then followed by an investigation of the impact of other considerations such as reconfigurability, metallic traces and matching two different dielectric media. Finally, the thesis outlines potential future work, including the exploration of three-dimensional beam shaping and reconfigurability as the next steps in metasurface design.October 202
Topology and entanglement in non-Hermitian quantum systems
No full textIn this project, we explore non-Hermitian topological systems, focusing on the asymmetric Su-Schrieffer-Heeger (SSH) model, a one-dimensional non-Hermitian system with dimerization, asymmetric hopping, and imaginary staggered potentials. Depending on parameter choices, the model can exhibit Hermitian, non-Hermitian, sublattice symmetric, and PT-symmetric behavior, providing a thorough view of different symmetry types and topological models. We investigate exceptional points as a phenomenon unique to non-Hermitian systems, and topological phase transitions based on bandgap closure and symmetry-breaking points. We study topological invariants as essential features of topological quantum systems, introducing two winding numbers to distinguish between the Hermitian and non-Hermitian SSH models with or without symmetries. We also propose a method to compute entanglement in non-Hermitian systems and explore how bulk-boundary correspondence needs modification, as the standard version doesn’t apply for non-Hermitian systems. We demonstrate how topological winding numbers in periodic systems correspond to singular values in systems with open boundaries. In the PT-symmetric case, we present a detailed phase diagram that has not been addressed in prior studies. We provide analytical solutions, supported by numerical calculations, for the eigenspectrum with both open and closed boundary conditions, as well as for the singular-value spectrum.February 202
Magnetic properties of nanoparticle arrays
No full textThis thesis presents an investigation of the magnetic properties and dynamics of maghemite (γ-Fe2O3) nanoparticle assemblies using atomistic spin dynamics simulations. The study focuses on the collective magnetic behavior that arises from the complex interplay between short intra-particle and long inter-particle interactions.
The presence of vacancies in the maghemite structure introduces an inhomogeneous effective anisotropy unique to each nanoparticle. In triangular arrays, the interplay between surface effective anisotropy and dipolar interactions leads to the formation of magnetic domains, with domain size decreasing as surface anisotropy increases.
The study first examines the magnetic ordering in triangular arrays of point dipoles. The simulations reveal ferromagnetic in-plane ordering with a six-fold anisotropy arising from the order-from-disorder effect, consistent with previous theoretical studies. The dipole interactions in the triangular array are then compared with those in maghemite nanoparticle arrays. While nanoparticle arrays with zero surface anisotropy exhibit similar behavior to point dipole arrays, the presence of surface anisotropy leads to the formation of magnetic domains, with domain size decreasing as surface anisotropy increases.
The spin-wave spectra of point dipole arrays reveal weak longitudinal modes and more dominant transverse modes, with the dispersion relations agreeing well with theoretical calculations. Spin wave excitations in the nanoparticle arrays are explored using Fourier analysis. In addition to propagating spin waves, localized modes are observed, originating from the hopping of magnetization between energy minima at the individual nanoparticle level. Surface anisotropy introduces spectral gaps and increases spin wave frequencies of the transverse and longitudinal modes, with the frequency at zero wave-vector following a quadratic dependence on surface anisotropy strength for the transverse spin waves and a linear dependence on surface anisotropy for the longitudinal spin waves (for small values of surface anisotropy).
The multiscale hierarchical model developed in this work captures the intricate interplay between intra-particle and inter-particle interactions. The atomistic simulations provide insights into the role of surface effects and defects in determining the magnetic properties of nanoparticle assemblies, highlighting the necessity of considering atomic-scale structure in the design and optimization of magnetic nanomaterials.October 202
Affective and aggressive behavioral reactions to ostracism: the roles of socioeconomic status and perceived primary and secondary control
No full textCanadians are increasingly reporting feeling lonely, socially isolated, or ostracized. Yet, instances of ostracism and its deleterious effects may not be equally distributed across the population. Many segments of society, including those with low socioeconomic status (SES), may be both more likely to experience ostracism and more reactive to it. Thus, they may be especially susceptible to experiencing its detrimental psychological and physical effects. According to theory on the relationship between SES and perceived control this heightened reactivity may result because individuals with low SES (LSES) may possess a limited reserve of perceived primary control that is directly targeted ostracism. Alternative perspectives, such as the shift-and-persist model, suggest that LSES may actually be less negatively affected by ostracism as a result of relying on perceived secondary control. These competing predictions were tested in a series of six online studies (N = 4420). While direct evidence of divergent affective reactions did not emerge, ostracism indirectly predicted increases in negative affect and hurt feelings among LSES. Evidence of aggressive behavioral reactions was also minimal. However, tentative findings suggested that LSES may react aggressively if certain factors exacerbate the threat posed by ostracism. Contrary to hypotheses, this enhanced reactivity appeared to be driven by reductions in perceptions of secondary control. Notably, behavioral responses characterized by escape and perhaps centred on restoring secondary control through sense making are suggestive of adaptive coping that may ultimately fuel resilience. This complex pattern of findings underscores the importance of directly addressing factors that contribute to the exclusion and devaluation of LSES and suggests that social policy efforts aimed at combating increasing feelings of loneliness, isolation, and ostracism and maintaining the well-being of Canadians need to be attentive to the socioeconomic position of their targets and their unique motivations.Canadian Psychological Association Student Research and Knowledge Mobilization Grant
University of Manitoba Tri-Council Top-Up Award
University of Manitoba Dr. Richard Douglas Oatway Memorial Fellowship
University of Manitoba Faculty of Arts J. G. Fletcher Graduate Research Award
University of Manitoba Faculty of Graduate Studies Research Completion ScholarshipOctober 202
De'VIA Art Centre: a hub for Deaf self-expression and cultural empowerment
No full textThe interior design profession must become sensitive to the indoor space requirements of the Deaf and hard-of-hearing users due to the increase in hearing issues worldwide. Just as interiors designed for the hearing consider their needs and culture, so must interiors for the Deaf people. This practicum provides a deaf-friendly art centre for the Deaf and hard-of-hearing people of Winnipeg, Manitoba. It strives to empower and foster personal growth in the Deaf community by providing interior environments designed according to their needs. The main principles informing the design framework for this project are related to design theories for the Deaf. The theories are drawn from Deaf space design (Bauman 2010), Sense of Place (Cresswell, 2004; Hummon, 1992; Steele, 1981; Colomina, 1996) and Collaborative Environment (Bruffee, 1999; , Lawson, 2001; Miller, 1989; , Durr, 2006), that provides a deeper understanding of the significance of Deaf art and inform the design of this practicum’s project, the De’VIA Art Centre, at the Wallace Building on the campus of the University of Manitoba in Winnipeg, Canada. Through interior design, the De’VIA Art Centre illustrates that being deaf is not a disability but a way of seeing the world differently. This project is set apart by its inclusivity, which allows hearing individuals to engage and interact with Deaf artists while prioritizing the empowerment of Deaf culture, safety and well-being of Deaf and hard-of-hearing individuals.October 202
Effect of serotonin on ventral V3 populations
Get PDFSpinal central pattern generators (CPGs) are responsible for the generation of locomotion characterized by alternation of flexor and extensor muscles and left and right limbs. However, to ensure stable movement, descending input from the brainstem provides on-going excitation to spinal CPGs. For instance, serotonergic descending inputs modulate spinal interneuron excitability. Within the spinal cord, interneurons (INs) can be characterized based on their genetic origins and molecular profiles. One such are V3 INs, having a vital role in regulating balanced motor output. Despite the importance of V3 INs in locomotion, and the importance of descending neuromodulation to initiate and maintain locomotion, it remains unknown how V3 INs respond to descending neuromodulation. We hypothesized that serotonin increases the excitability of ventral V3 INs. Using in-vitro whole cell patch clamp electrophysiology, basic intrinsic and firing properties of V3 INs from thoracolumbar spinal cord slices of Sim1Cre; TdTomato mice were recorded from 3 different age groups (p1-p3, p4-p8 and p9+). Comparisons of intrinsic (rheobase, input resistance, threshold potential and afterhyperpolarization) and firing properties of V3 INs were made between pre-bath and bath application of serotonin. V3 INs demonstrated age-dependent trends where 1/3 of INs had an increase in excitability, another 1/3 had a decrease in their excitability and an additional 1/3 of INs displayed no change in their excitability in response to serotonin(p>0.05). In the future, these findings will lead to better understanding of the differential role of serotonin and its neuromodulatory effects on spinal INs.May 202