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Beyond language: tracing social identity through pottery. Stylistic analysis of Early Iron Age communities in southeastern South Africa
No full textThis dissertation examines the relationship between pottery style and social identity among Early Iron Age communities in southern Africa, offering an alternative and novel framework for interpreting stylistic variation. While effective in mapping large-scale cultural patterns, traditional analytical methods are limited in their ability to capture smaller-scale social dynamics. This research combines design symmetry analysis with Bayesian modelling, introducing a temporal approach emphasizing continuity and gradual change over rigid, periodized phases.
Through this approach, the study demonstrates that pottery style is not simply a static marker of cultural identity but a dynamic expression of social relationships, environmental factors, and shifting design networks. By interpreting ceramic design within broader assemblages, this dissertation shows how pottery reflects the intricate processes of community interactions, learning networks, and identity formation across multiple scales. The findings suggest that “design networks,” rather than fixed cultural groups, shaped regional stylistic patterns and that pottery served as a medium for stability and transformation within these communities.
This new framework expands the potential for archaeological analysis to explore social identities beyond language groups, contributing to a deeper understanding of how early farming societies in southern Africa engaged with and adapted their material culture over time.University of Manitoba Graduate Fellowship, the University of Manitoba Institute for the Humanities Award, the JG Fletcher Award, the Dr. Bonnie C. Hallman Graduate Student Bursary, and the William E. Harrison BursaryMay 202
Low-overhead Kronecker-based intelligent reflective surfaces for next-generation wireless networks
Get PDFThis thesis investigates the optimization of Intelligent Reflective Surfaces (IRSs) in wireless communication networks, focusing on reducing control overhead and enhancing network performance. A key contribution of this work is the introduction of a Kronecker-based phase shift model, which significantly reduces the overhead required for controlling the phase shifts of the IRSs. By representing the phase shifts of each IRS with fewer control signals, this approach simplifies the wiring systems in IRSs and enables faster switching between configurations. The research initially focuses on a downlink transmission system, formulating an optimization problem based on the minimum mean square error (MMSE) criterion. This results in a multi-variable non-convex problem, which is then tackled using alternating optimization (AO). The Kronecker-based method is shown to outperform traditional phase shift control in terms of efficiency and scalability.
The thesis then extends this model to cell-free multiple-input multiple-output (MIMO) systems, incorporating multiple IRSs to enhance coverage, mitigate interference, and improve performance. Here, optimization frameworks for uplink and downlink communication are developed, focusing on joint optimization of IRS phase shifts and beamforming/receiver matrices at distributed base stations (BSs). The performance is evaluated using sum-rate and good-put metrics, with numerical simulations demonstrating that the proposed approach reduces control overhead while improving system performance in large-scale environments. The results highlight the potential of the Kronecker-based method for efficient IRS deployment in future wireless networks.May 202
Structural and biophysical characterization of Net-1-UNC5B interaction: from known receptor to a novel binding partner
No full textThe formation of the nervous system relies on a crucial process called axon pathfinding. This process involves the precise growth and connection of axons to their appropriate target site signaled by guidance cue ligands such as Netrin-1, Ephrin, Semaphorin and Slit. The growth cones, at the end of axons, sense guidance cues and mediate axonal growth and direction. Net-1 can attract or repel growth cones through binding to transmembrane receptors, Uncoordinated family member 5 (UNC5), Deleted in Colorectal Cancer (DCC) and Neogenin (NEO). Net-1-receptor complexes trigger intracellular signaling cascades that direct axon trajectories towards Net-1 through DCC or NEO, and away from it through UNC5 dependent/independent DCC. Beyond axon guidance, Net-1 receptors also function as dependence receptors. Overexpression of Net-1 acts as a survival factor and inhibiting UNC5 and DCC mediated apoptosis in various cancers. Inhibition of Net-1 interactions with its receptor has been shown to trigger tumor cell death, making it a potential therapeutic target.
This study presents a comprehensive biophysical and structural examination of the highly dynamic Net-1 in complex with UNC5B. The objective is to elucidate novel insights into this interaction and identify potential molecular binding partners. A combination of in solution biophysical techniques including size-exclusion chromatography (SEC), SEC coupled multi-angle light scattering (SEC-MALS), analytical ultracentrifugation (AUC), and small-angle X-ray scattering (SAXS) were used to characterize Net-1 alone and in complex. The biophysical and structural analyses of Net-1-UNC5B complex, and Net-1-anti-Net-1 antibody further elucidated the mechanism of Net-1-UNC5B interaction, and the mode of inhibition by the antibody as a therapeutic strategy for cancer.
Finally, we found a direct interaction between Net-1 and Robo2 that suggests a novel mechanism which connects Net-1 and Slit signaling pathways. Using biophysical and structural techniques, Net-1 was found to interact with Robo-2 in a similar manner as UNC5B. This finding can highlight the molecular mechanism of the DCC-Robo heterodimerization in commissural axon guidance where Net-1 and Slit signaling pathways are coordinated. Collectively, the biophysical and structural insights presented in this study regarding Net-1 interactions with its receptors can guide the design of specific inhibitors to disrupt Net-1-receptor complexes.February 202
Fine-tuning an Automatic Speech Recognition model for a Canadian Indigenous counselling program
No full textAutomatic Speech Recognition (ASR) systems have seen a marked improvement in performance after adopting the End-To-End (E2E) approach. However, the performance of ASR models is still largely dependent on the quantity and quality of data they are trained on. Popular ASR systems today are trained on thousands of hours of data but consistently fail to maintain their performance when exposed to outlier accents, vocal pitches, and demographic speech. While ASR systems have greatly improved in recent years, the biggest hurdle remains the lack of niche speech data. Most available speech data fall into a few voice types and are not representative of the average ASR system user. The majority of machine learning projects require large amounts of data.
However, the adaptability of E2E ASR models allows them to be fine-tuned to outlier speech using small amounts of representative data. The project presented in this thesis aimed to fine-tune an ASR model for use in an Indigenous Counselling Program. An open-source ASR system called Mozilla DeepSpeech was used to train the models used for the project. Representative speech data was gathered from audiobooks and organized into speech corpora to fine-tune DeepSpeech’s pre-trained models. DeepSpeech’s live transcription software was also implemented on the Unity Development Engine to ensure compatibility with the Indigenous Counselling Program. Three models were trained using the new speech data. Two models were trained using pitch frequency-specific data. One general model was trained using all the new speech data.
The results showed a minimum average relative WER or WER improvement of 8.90% for all the models, on the dataset they were trained on. Furthermore, the general model showed little to no improvement in performance over the pitch specific models when tested on their trained datasets. This demonstrated the importance of using representative speech data in ASR model training. Overall, the models showed a marked improvement in performance when trained on the intended user accent and voice type.February 202
Migration of polycyclic aromatic compounds from food storage containers to food
No full textMy thesis was geared towards understanding the migration of a suite of polycyclic aromatic compounds (PACs) from commercially available plastic containers. The literature is replete with examples of chemicals that can migrate of from plastics (e.g., bisphenol-A, flame retardants) but to my knowledge a comprehensive study on PAC migration from different plastic types has not been reported. This is surprising considering that most of the plastics in commerce are derived from crude-oil and PACs are known to be one of the main contaminants in crude-oil. Furthermore, many PACs are known to cause negative health outcomes in wildlife. To understand PAC migration from plastics, I took four plastic-types and incubated them separately at 40oC with dichloromethane and olive-oil. At prescribed time-points I sampled the incubation media and measured PACs using gas chromatography tandem mass spectrometry. I was able to detect several polycyclic aromatic hydrocarbons (PAHs) and their alkylated derivatives. I also was able to report the rate of migration of four PAHs from high-density polyethylene. My work is important because in addition to reporting the migration of many PACs from plastics for the first time, it also provides evidence for a poorly studied route of human exposure to these compounds and further impetus for investigation into biopolymers and other renewable plastic derivatives.February 202
Challenges faced by senior women
No full textThe World Health Organization’s Global Strategy and Action Plan sets out objectives related to aging that maximize functional ability, and hence, have effects on both intrinsic capacity as well as the external physical and social environments that older adults live in. Thus, there is a strong link with the study that the Status of Women Committee is undertaking. For example, affordable housing and transportation are both key social determinants of health, and are highly linked to quality of life
The impact of COVID-19 on the roles and responsibilities of respiratory therapists in primary care in Ontario, Canada
No full textBackground/Introduction: The COVID-19 pandemic impacted health care providers as their roles changed in providing care for patients with chronic respiratory disease. The impact of the pandemic was significant in Ontario, Canada, where the already strained health care system responded by reducing in-person primary care visits and replacing them with virtual visits. Some respiratory therapists working in primary care pivoted to the provision of virtual care, while others were redeployed to acute care to manage the patient surge. Few articles explore the roles and responsibilities of respiratory therapists working in primary care.
Purpose: The purpose of this qualitative case study is to describe the impact of the COVID-19 pandemic on the roles and responsibilities of respiratory therapists working in primary care in Ontario, Canada. The research objectives are to define the roles and responsibilities of respiratory therapists working in primary care, explore the extent of role ambiguity, and describe how COVID-19 has impacted their practice.
Methods: Using case study methodology, virtual semi-structured interviews were conducted with four respiratory therapists working in primary care in Ontario. Data was analyzed using Stake’s method of case study analysis.
Results: Respiratory therapists are a well-respected member of the interprofessional health care team, they appreciate the autonomy of their roles in primary care, and these roles were adapted during the pandemic to continue providing care to patients with chronic respiratory disease. The challenges posed by the pandemic resulted in some primary care clinics moving to virtual care, while other clinics suspended services at the peak of the pandemic. Public fear of contracting the COVID-19 virus prompted some patients to discontinue care with their primary care team, and respiratory therapists felt devalued and disconnected from their patients.
Discussion: The COVID-19 pandemic highlighted the strengths and vulnerabilities within the primary care setting and identified that there is a need for more respiratory therapists working in primary care to utilize their skill set in managing patients with chronic respiratory disease. Pivoting the role of the respiratory therapists to provide virtual care provides insight into how to prepare for future pandemics and minimize the disruption of care.
Conclusion: Future research into the roles and responsibilities of respiratory therapists working in primary care could demonstrate the need for these health care professionals in reducing the burden of chronic respiratory disease on the health care system and increase patient outcomes.February 202
Perspectives on the role of the nurse within the interprofessional team from senior practicum nursing students who received interprofessional education
Get PDFInterprofessional education (IPE) can be defined as a program that allows two or more professions to learn about, from, and with each other to enable effective collaboration and improve health outcomes (World Health Organization [WHO], 2010). As undergraduate nursing students transition into practice, they may reflect on their IPE experiences and utilize the competencies and skills taught through IPE. The purpose of this study was to explore how IPE influenced undergraduate nursing students’ perceptions on the role of a nurse within an interprofessional collaborative team, as they transitioned from a student to a registered nurse. Using a methodological approach of interpretive description, virtual interviews were conducted to examine the research question.
The research question was, “How do undergraduate students at the end of their nursing program perceive the influence of interprofessional education experiences on their understanding of the role of the nurse in the interprofessional team?” Fourteen participants took part in the virtual interviews. They were interviewed using a semi-structured interview guide. Using coding and thematic analysis, one overarching theme and three subthemes were found. The overarching theme was that perspective of the role of the nurse within the interprofessional team was evolving and developing throughout the program. Three subthemes were found to be a process of: knowledge of roles, confidence in practice, and finding one’s voice. This progression led participants to evolve from receiving interprofessional education (IPE) to actively participating in collaborative practice (IPC). Through these findings, the perspectives in which nursing students view the role of the nurse on the interprofessional team can be used to further future research on IPE and undergraduate nursing students.February 202
The role of the cAMP/PKA and cGMP/PKG pathways in the regulation of the transbranchial ammonia excretion in the green shore crab, Carcinus maenas
Get PDFAs a toxic nitrogenous waste, ammonia causes ionoregulatory and neuronal dysfunction in aquatic animals. Without mechanisms to convert ammonia into less toxic molecules such as urea and uric acid, ammonotelic animals excrete ammonia directly into the surrounding environment. In order to deal with conditions causing possible elevated hemolymph ammonia levels, such as feeding, an efficient ammonia excretion process must be in place to keep the hemolymph ammonia levels within a tolerable range. While the excretory mechanisms of ammonia have been investigated in detail in fish and crustaceans, the intracellular regulation of these processes is basically unknown. To investigate the involvement of two key pathways, the cAMP/PKA and cGMP/PKG pathway, in the ammonia excretion process, gills from osmoregulating green shore crabs, Carcinus maenas, were isolated and perfused with hemolymph-like solutions containing either 200 µmol L-1 or 500 µmol L-1 NH4Cl, mimicking the hemolymph ammonia levels in the resting state and after feeding, respectively. Basolateral application of the adenylyl cyclase activator or membrane-permeable 8-Bromo-cAMP, caused a significant decrease in the ammonia excretion rate. In addition, after PKA activation by 8-Bromo-cAMP, metabolically generated ammonia increased and the majority was now transported towards the hemolymph and not, as seen under control conditions, into the environment. Together, this suggests that the cAMP/PKA pathway promotes an ammonia retention mechanism. In contrast, activating the cGMP/PKG pathway by the application of membrane-permeable 8-Bromo-cGMP, resulted in an increase of the transbranchial ammonia excretion rate, which could be blocked by the PKG inhibitor KT5823. In addition, participation of nitric oxide synthase (NOS) in the cGMP synthesis via the soluble guanylyl cyclase is suggested due to the observed inhibitory effect on the branchial ammonia excretion after basolateral application of the NOS inhibitor L-NAME.
In conclusion, cGMP/PKG pathway, not the cAMP/PKA pathway promotes transbranchial ammonia excretion across the gill epithelium in C. maenas. The cAMP/PKA pathway is involved in a so far undescribed ammonia retention mechanism. The provided data will offer a basis for new venues investigating epithelial ammonia transport processes in general.May 202
HIV vaulnerability among people who inject drugs (PWID): findings from the Bangladesh integrated biological and behavioural surveillance (IBBS) study 2020
Get PDFIntroduction: People who inject drugs (PWID) contribute significantly to the global HIV burden. Various individual and contextual factors exacerbate the risk of HIV among PWID, this problem is particularly acute in low- and middle-income countries, where resource constraints impede effective prevention and treatment efforts. Although Bangladesh is classified as a low HIV prevalence country, and despite national efforts, including surveillance through the Integrated Biobehavioural Survey (IBBS), gaps in evidence and actionable insights persist. This study aims to analyse the latest IBBS 2020 data to identify risk factors associated with HIV vulnerability among PWID in Bangladesh, informing culturally relevant and targeted harm reduction strategies to mitigate these risks.
Method: This study analysed data from IBBS, which used a two-stage cluster sampling and Time Location Sampling methods to recruit participants. Data were collected across four domains: (1) Sociodemographic characteristics, (2) Drug and Injection-Related Behaviours, (3) Sexual Behaviours, and (4) Co-infections, with blood samples collected for HIV, hepatitis-C, and syphilis serological testing. Sample weights were applied to adjust for the complex survey design. Descriptive statistics summarized participant characteristics and risk behaviours. Two binary logistic regression models were used to identify HIV risk factors: The Fully Adjusted Model, which included all plausible confounders and used the Wald backward elimination method to determine significant predictors, and the Partially Adjusted Model, which controlled for age, gender, and education to explore intermediate factors through adjusting confounding or mediation.
Result: Overall, the prevalence of HIV among PWID was 4.1%. Social exclusion (AOR: 1.71, 95% CI 1.1, 2.7). Hepatitis C infection (AOR: 2.57, 95% CI 1.6, 4.0), drug use of more than 10 years (AOR: 3.74, 95% CI 1.3, 10.8), injecting once or more daily (AOR: 5.23, 95% CI 2.6, 10.7), having multiple injecting partners (AOR: 3.11, 95% CI 1.8, 5.3) sharing injecting accessories (AOR: 2.55, 95% CI 1.5, 4.4) and engaging with a commercial sex partner (AOR: 1.80, 95% CI 1.1, 2.9) emerged as significant predictors of HIV risk among PWID patients.
Conclusion: This study reveals the heightened HIV risk among PWID in Bangladesh, driven by intertwined social, behavioural, biological, and structural factors. It underscores the urgent need for tailored, holistic interventions combining harm reduction, structural reforms, and biomedical strategies to address vulnerabilities, reduce high-risk behaviours, and improve healthcare access for this marginalized group