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Multichannel Wiener Filtering for Dual-Microphone Speech Processing in a Car Environment
No full textWith advancements in automotive electronics and sensors, the sound pick-up using multiple microphones has become feasible for hands-free telephony and voice command in-car applications. Adding a second microphone so that both driver and passenger can have dedicated microphones can help in better sound pickup. However, challenges remain in effectively processing multiple microphone signals due to bandwidth or processing limitations. If a single resulting microphone signal is to be transmitted or processed, adding (mixing) the microphone signals or switching between them can be efficient and cost effective solutions. However, switching between microphone signals can cause sudden changes in the acoustic path between loudspeakers and microphones, leading to performance decay in the acoustic echo canceling module. And mixing the two microphone signals can lead to echoes and notch filtering effects (spectral holes) in the resulting mixed signal. This work explores the use of the Multichannel Wiener Filter algorithm with a two-microphone in-car system to enhance speech quality for driver and passenger voice, i.e., more specifically to mitigate notch-filtering effects caused by echoes and improve background noise reduction. We evaluate its performance under various noise conditions using modern objective metrics such as the Deep Noise Suppression Mean Opinion Score. The effect of head movements of driver/passenger is also investigated. The proposed method is shown to provide significant improvements over a simple mixing of microphone signals
Lipid Modulation of Ligand-Gated Ion Channels
No full textLigand-gated ion channels (LGICs) are a diverse family of membrane proteins which play a key role in neuronal communication. The neuronal lipid membrane in which LGICs are embedded is a complex and dynamic environment which, over decades of LGIC research, has been shown to influence the function of these proteins. The specific lipid requirements and functional effects of membrane lipids differ by LGIC type. The presence of polyunsaturated fatty acids (PUFAs) modulates the pH response of acid-sensing ion channels (ASICs), and in the case of subtype ASIC3, can even activate the channels at physiological pH. Another type of LGIC, the nicotinic acetylcholine receptor (nAChR), requires the presence of anionic lipids and/or cholesterol for function. It has been proposed that lipids exert their function on LGICs through direct interactions at lipid binding sites. To date, however, these binding sites are poorly described, and their existence remains uncertain. High resolution cryo-EM structures of ASICs and nAChRs have been solved in recent years showing density attributed to bound lipids. Using multiscale molecular dynamics (MD simulations), I embed high-resolution structures of ASIC and the nAChR in membrane patches of interest to observe the dynamics of specific lipid interactions with these channels. My simulations suggest prolonged, direct interactions of functionally relevant lipids with the transmembrane domains (TMDs) of ASICs and nAChRs. Key arginine residues at the outer leaflet region of ASIC TMDs coordinate high-occupancy PUFA interactions which can be disrupted by in-silico mutagenesis. Similarly, the activity-promoting lipids phosphatidic acid (PA) and cholesterol bind to specific sites with longer duration than the lipid phosphatidylcholine (PC), which does not promote activity. The relative binding free energy of PA and PC was calculated using free energy perturbation at a conserved nAChR inner leaflet site, estimating a 1.5 kcal/mol difference between the two lipids, revealing slight preferential binding for PA. Together these findings suggest that activity-promoting lipids species bind to specific lipid binding sites which higher affinity than bulk membrane lipids, and these interactions could stabilize active or activatable states of LGICs
Leveraging Homologous Recombination to Generate Clone-less in vivo Assembly and Integration of DNA to Genetically Modify Saccharomyces cerevisiae Using CRISPR-Cas9
No full textSaccharomyces cerevisiae's well-characterized genome and efficient homologous recombination capabilities make it a powerful model organism for genetic engineering, enabling the development of precise genome modification techniques. However, simultaneous multi-locus gene integration (multiplexing) remains challenging, often requiring extensive and tedious in vitro cloning. This thesis hypothesizes that a novel yeast integrating plasmid, envisioned as an EasyClone Expansion Pack, can be designed to enable two-step multiplexing leveraging homologous recombination and bypassing in vitro cloning. To accomplish this, we developed a clone-less in vivo DNA assembly method, demonstrating a 20-fold increase in transformation efficiency with CRISPR-Cas9-mediated DNA breaks. A cost-effective multiplexing workflow was established using 200 bp chromosomal homology regions and 30 bp overhangs on transgenes. The foundational design of the expansion pack plasmid, including one-step linearizability and unique homology regions, was validated. This research offers a cost-effective and streamlined approach for strain engineering for use in diverse bioproduction and biomanufacturing applications
A multi-method evaluation of how equity deserving communities were engaged in research
No full textAbstract Background We aimed to understand and evaluate the types, experiences and levels of engagement of all groups engaged in the OPTimise research study. The OPTimise study used virtual community engagement to engage equity-deserving populations across three sites to help public health units tailor strategies to improve vaccine uptake during COVID-19. Our evaluation was uniquely conducted at arm's length from the OPTimise researchers who facilitated the virtual engagement with these groups. Method The community members involved in research (community leaders and citizen partners) were invited to complete the 22-item Patient Engagement in Research Scale (PEIRS-22) survey to understand the nature of engagement. Twenty-three participants were invited to complete the survey and 19 (83%) completed the survey. We conducted individual and focus group interviews with members of all four groups (community leaders, citizen partners, public health unit knowledge user and connectors, and methods researchers) to learn about their engagement experiences with the OPTimise study and research team. Thirty-five participants were invited to join an interview or focus group interview with 22 (63%) completing an interview. Results OPTimise study members reported “extremely meaningful” engagement which is the highest level on the PEIRS-22 scale. The interviews demonstrated that the OPTimise study was designed appropriately across the three sites. Interviews were analyzed based on four topics: relationship management, supporting processes, power sharing, and satisfaction with operations. Qualitative and quantitative data are compared to the Levels of Patient and Researcher Engagement in Health Research framework. Citizen partners and methods researchers reported being engaged at the level of “lead” on the framework. Community leaders reported their level of engagement as at the level of “involve” throughout the study while connectors and public health knowledge users reported their level of engagement was at the level of “involve episodically” throughout the study. Conclusions This evaluation found that building authentic relationships between the OPTimise research team and participants was key in the early phases of the OPTimise study. Researchers on future projects could benefit from developing working relationships with organizations who can connect with the target audience to facilitate trust building between researchers and engagement participants, especially in virtual environments
FSL Teacher Education - Navigating the rising tide together
No full textAcross the educational landscape, we are experiencing a rising tide—a growing shortage of qualified French as a Second Language (FSL) teachers. Like waves gathering force on the horizon, the issue has been building for years, eroding the foundations of strong French language instruction in schools. Faculties of Education and school boards are being called to come together, respond to the surge, and build strong foundations to weather the storm. Our collective response began with two events, where stakeholders were brought together to explore how we might navigate this challenge. Our guiding question: How can we strengthen FSL teacher learning and retention? As we wade deeper into the conversation, two powerful anchors have emerged from the current: mentorship and relationships. These themes provide steady ground beneath shifting waters, supporting both the learning and long-term success of FSL teachers. But not all aspects of our FSL Teacher Education program were met with equal clarity. Among the waves of ideas, three areas surfaced as points meriting ongoing dialogue: CEFR/DELF Correcteur Training, French language course requirements, French proficiency testing. Rather than smoothing our differing perspectives, our goal is to ride the waves together, using our shared commitment to mentorship and relationships as a compass that can guide us through choppy waters. By exploring how we understand these areas differently— and where we align—we can begin to co-create a shared direction. So, where do we go from here? The tide is shifting, and with it, an opportunity to shape the shoreline of FSL teacher preparation. Our next steps are not about controlling the waves, but about learning to navigate them together by building a shared vision of mentorship, leveraging shared values as our anchor and creating a culture of ongoing dialogue.FSL Challenge (Ontario Ministry of Colleges and Universities
Understanding patients’ perceptions of uncomplicated low back pain: a theory-informed qualitative study using the Common-Sense Self-Regulation Model
No full textAbstract Background Uncomplicated low-back pain (LBP), referring to LBP without symptoms that suggest an underlying medical or surgical cause, is a common and challenging problem for patients and primary healthcare providers. Multiple guidelines discourage the use of diagnostic imaging for uncomplicated LBP due to cost and lack of benefit; despite this, diagnostic imaging remains overused in this condition. Study of primary healthcare providers suggests that patient expectations contribute to imaging for uncomplicated LBP. Dedicated study of patient understanding and experiences of uncomplicated LBP is necessary to design interventions to reduce unnecessary diagnostic imaging. Methods In this theory-guided qualitative study, people with uncomplicated LBP were recruited for a semi-structured interview. The Common Sense – Self-Regulation Model (CS-SRM), a framework that explores the relationship between a patient’s perceptions, beliefs, and behaviors around their illness and the outcome of their illness, was selected to direct development of the interview guide and analysis. Higher-level themes were created to list patient-related drivers of unnecessary diagnostic imaging for uncomplicated LBP. Results Thirteen participants (7 female) had experienced uncomplicated LBP for a median of 5 years (IQR 2–20 years; range 1 to 30 years). Framework analysis based on the CS-SRM suggested that most participants understood their uncomplicated LBP as a permanent part of their lives, though some felt that the pain could be controlled or prevented. Participants shared a range of coping mechanisms, including social support, medication, and exercises. For most participants, uncomplicated LBP negatively affected their lives emotional wellbeing characterized by a sense of loss from missing life events due to pain. Nearly all participants had visited their primary care physician (n = 11) and most underwent diagnostic imaging (n = 8); however, participants generally reported that they had not requested diagnostic imaging (n = 8). Several participants reported that they wanted validation and symptom-management advice from their physician rather than diagnostic tests. Conclusions In contrast to other studies, we report that most patients with uncomplicated LBP in our setting did not request diagnostic imaging. Patient-facing interventions to address unnecessary diagnostic imaging for uncomplicated LBP may be more effective if they address illness conceptions identified in this study; for example, interventions should convey empathy by acknowledging patient worries, validating suffering, describing potential causes or triggers, addressing self-management strategies, and describing the natural history of uncomplicated LBP
In Search of Home: Housing Crisis in Ottawa and its Effects on Government-Assisted Refugees
No full textIn this thesis, I examine how Government-Assisted Refugees (GARs) from different countries, who arrived in Canada under the Resettlement Assistance Program (RAP), have resettled in Ottawa amidst an unprecedented housing crisis. Drawing on two bodies of scholarship, political anthropology and Critical Refugee Studies (CRS), and anthropological fieldwork conducted between July 2023 and January 2025, I trace the effects of this crisis on GARs' experience of resettlement.
Drawing upon my participant observation at the Catholic Center for Immigrants (CCI), interviews with GARs, CCI and RAP employees, and community volunteers, I argue that Canada's resettlement process generates new forms of displacement and food precarity by enforcing an unrealistic one-year timeline for independence. The thesis develops this argument across three chapters: the first chapter traces housing and resettlement policies from the perspective of CCI and RAP employees. I examine GARs' experiences from their initial arrival to their move to more permanent housing. By focusing on GARs' agency, I demonstrate how they engage with regulations to find their desired homes. Finally, the last chapter delineates the hidden effects of the housing crisis, including food insecurity.
By following GARs' resettlement process, from their first step at CCI to their permanent housing, I examine policies, welfare programs, benefits, the housing market, and state-led institutions as assemblages. Through this exploration, I document how some GARs manage to find their desired home in Canada, while others experience ongoing displacement and precarity. Additionally, I attempt to shed light on CCI and RAP employees' experiences of working in the midst of a housing crisis and policy ruptures to facilitate GARs' resettlement. Their recommendations and insights are intertwined with GARs' narratives in this thesis's chapters. Finally, I focus on GARs' agency and homemaking strategies among the obstacles that they face from their first day of arrival in Ottawa
A systematic review of the effectiveness and utility of Lyme disease prevention measures in Canada, the United States, and Europe
No full textAbstract Background This systematic review aimed to assess the effectiveness of interventions which reduce human-tick encounters, prevent tick bites, and reduce the risk of Borrelia burgdorferi transmission, and to evaluate knowledge on the cost, environmental impact, social impact and acceptability, and public health impact of these interventions. Methods The search was conducted in Medline, Embase, Global Health, CAB Abstracts, Cochrane CENTRAL, Scopus, and Econlit for relevant literature in March 2022 and was updated in November 2024 and followed PRISMA guidelines for systematic reviews. Inclusion was applied at citation and full text, after which articles were assessed for risk of bias and data was extracted by two independent reviewers. Studies were summarized by intervention type (landscape management, host animal parasitism and movement, chemical/natural/botanical applications, personal protection) and a multi-study synthesis of tick suppression effects was conducted for interventions that reported the density of infected nymphs as the primary outcome. Results One hundred and twenty-seven studies published between 1977 and 2024 were included in this systematic review. Most studies (n = 62) were classified as host-targeted interventions. Twenty-five studies were included in the multi-study synthesis of tick suppression effects, which suggested that chemical tick control methods are the most effective and consistent intervention type with 93.8% mean suppression of questing nymphs. Conclusion While some strategies such as chemical acaricides were shown to have greater effectiveness, factors such as social acceptability and resistance, environmental impact, cost, and feasibility should be considered when selecting the most appropriate intervention to maximize the utility of the intervention
Decision Support for Adults Considering COVID-19 Booster Vaccinations
No full textPurpose
To develop and conduct preliminary testing of a decision support intervention to address the decisional needs of older adults considering COVID-19 booster vaccinations.
Methods
Multi-methods, guided by the Ottawa Decision Support Framework, were used. Study 1 identified decisional needs of Canadian adults who reported difficulty making COVID-19 vaccination decisions using data from two population-based cross-sectional surveys; Study 2 identified decisional needs of older adults considering COVID-19 booster vaccinations using a systematic review; Study 3 co-developed and iteratively tested a PtDA for older adults considering COVID-19 booster vaccinations.
Findings
In study 1, 490/1454 (33.7%) participants in Year 1 of the COVID-19 pandemic and 475/1718 (27.6%) in Year 2 identified COVID-19 vaccinations as the most difficult decision. Respectively, 22.7% and 26.3% participants had a clinically significant decisional conflict. Factors making vaccination decisions difficult were worry about choosing the ‘wrong’ option (45.5%, 32.0%), difficulty separating misinformation from scientific evidence (39.4%, 30.9%), and worry about getting COVID-19 (30.4%, 30.9%). For participants who made the vaccination decision, significant decision regret increased from 23.9% in Year 1 to 38.4% in Year 2.
In study 2, ten studies of older adults considering booster vaccination identified decisional needs including uncertainty about the decision (e.g., 32.3% vaccine hesitancy), inadequate knowledge about effectiveness, safety, and eligibility for booster vaccinations, and lack of resources to support decision-making.
In study 3, findings above were combined with evidence from clinical practice guidelines to co-develop a PtDA with researchers, a patient and a family caregiver. Three iterative rounds of testing were conducted with 14 older Canadians and 5 healthcare professionals. Participants reported the PtDA was acceptable and would help older Canadians prepare for making decisions about booster vaccinations.
Conclusion
During the COVID-19 pandemic, adults in Canada reported unmet decisional needs, including decisional conflict and decision regret about COVID-19 vaccination decisions. Unmet decisional needs were also identified from international literature. The PtDA was reported as useful for assisting older adults in Canada in making booster vaccination decisions. Further research could more rigorously evaluate the PtDA and determine ways to disseminate and implement it with people feeling hesitant about COVID-19 vaccinations
Therapist Self-Disclosure and Cultural Empathy from the Perspective of Racial-Ethnic Minority Clients
No full textThe purpose of this study was to explore the experience of racial/ethnic minority (REM) clients during therapy when their therapist self-disclosed something personal to them. The literature suggests that therapist self-disclosure (TSD) with REM clients may play a role in cultural empathy, that is when a therapist responds to differences and similarities between them and the client in a way that can contribute beneficially to the quality of and dynamics within the therapeutic relationship. As little is known about the relationship between therapist disclosure and cultural empathy, the research question for this qualitative study was: “What are REM clients’ experiences of cultural empathy during cross-cultural counselling when their therapist self-discloses to them?”. To this end, I conducted a narrative inquiry to obtain rich stories of cultural empathy from REM clients who have experienced TSD during cross-cultural counselling. I audio-recorded interviews with four participants who were cis-gender women ranging from their early 20s to mid-to-late-30s. I analyzed the transcribed interviews using Braun and Clark’s (2006) Thematic Analysis. I generated several themes that followed a narrative structure, including client cultural context, expectations about therapy, therapy process, experiences of TSD, definitions of cultural empathy, and reflections about therapy. I used the themes to organize and develop participant narratives as the output of the results. I offered my interpretations of participants’ experiences using tenets of relational-cultural theory. The narratives garnered from this study contributed to the currently limited understanding of REM client perspectives, their experience of TSD in a cross-cultural context, and the potential role of TSD in therapists conveying cultural empathy. It is my hope that these narratives will deepen the understanding of culturally responsive therapy and improve the quality of care that racial/ethnic minority clients receive