MSpace

MSpace is the University of Manitoba’s Institutional Repository. The purpose of MSpace is to acquire, preserve and provide access to the scholarly works of University faculty and students within an open access environment.

 

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Open Access
Energy-aware and RIS-assisted communications in UAV-based wireless networks
(2024-09-26) Sekander, Silvia; McLeod, Robert D. (Electrical and Computer Engineering); Wang, Yang (Computer Science); Zhao, Lian (Toronto Metropolitan University); Hossain, Ekram
Unmanned aerial vehicles (UAVs) advance 5G and 6G networks with flexible deployment and enhanced coverage. However, their limited onboard energy poses challenges, requiring optimization through advanced energy harvesting, flight planning, and adaptive protocols. On the other hand, Reconfigurable Intelligent Surfaces (RISs) are emerging as a transformative technology for future wireless systems, particularly in the context of 6G for dynamically improving signal strength and coverage. Integrating RISs with UAVs addresses propagation issues, enhancing communication with RISs on buildings or UAVs. However, several critical research areas remain unexplored. These include understanding the complex radio wave propagation characteristics in aerial environments, optimizing the deployment of 3D RIS arrays to maximize their benefits in dynamic scenarios, and ensuring seamless integration of UAVs and RISs into existing and future wireless standards. Overcoming these challenges will be pivotal in harnessing the full potential of UAVs and RISs to meet the demanding requirements of 6G networks, thereby ushering in a new era of pervasive and high-performance wireless connectivity. This thesis addresses UAV-assisted communication challenges, focusing on energy harvesting and deployment optimization. It models solar, wind, and hybrid energy scenarios, deriving expressions for harvested power to evaluate outage probabilities using moment generating functions (MGF) and Gil-Pelaez inversion. It also explores distributed STAR-RIS networks versus multi-antenna UAV systems, optimizing multi-user scheduling, STAR-RIS shifts, and UAV beamforming using semi-definite programming, integer relaxation, and convex approximation, showing significant performance gains and enhancing UAV efficiency.
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Open Access
Quantization of random orthonormal matrices with application to adaptive transform coding
(2024-09-23) Boragolla, B. N. Weerasinghe Mudiyanselage Rashmi Amadini; Sherif, Sherif (Electrical and Computer Engineering); Ashraf, Ahmed (Electrical and Computer Engineering); Bajić, Ivan (Simon Fraser University); Yahampath, Pradeepa
This thesis explores the quantization of orthonormal random matrices, an important component in the adaptive transform coding of images and video. While vector quantization in Euclidean space has been extensively studied, applying these methods to orthonormal matrices is challenging due to the inherent orthogonality constraints. Directly solving the constrained optimization problem in Euclidean space is difficult. Therefore, this research investigates several novel constructive approaches to the quantization of orthonormal random matrices, specifically for application in video and image compression. These matrices serve as approximations to the Karhunen-Loève Transforms (KLTs) of pixel blocks in images. The main objective of this thesis is to design an optimal codebook of transform matrices that can be utilized in adaptive transform coding, thereby enhancing compression efficiency. This thesis first investigates solving the constrained optimization problem in Euclidean space as an unconstrained optimization problem on the orthonormal matrix manifold. The primary goal is to minimize the mean square error (MSE) of transform coding, and this thesis derives an objective function for minimization based on high-rate analysis. Since the minimization problem lacks a closed-form solution, this thesis proposes a coordinate descent algorithm, which is guaranteed to converge to a local minimum. The proposed algorithm can be used to design both separable and non-separable transforms from sample image data. Experimental results demonstrate that adaptive transform coding using codebooks designed by the proposed algorithm outperforms both non-adaptive coding based on the widely used two-dimensional discrete cosine transform (2D-DCT) and adaptive coding using transform codebooks designed by various recently reported methods. This thesis further investigates a model-based approach to transform matrix codebook learning by modeling natural image blocks as finite lattice non-causal homogeneous Gauss Markov random fields (GMRFs) with Neumann boundary conditions. The proposed method involves the estimation of GMRF parameters. While the standard approach for GMRF parameter estimation is maximum likelihood, this thesis introduces a novel method based on high-rate analysis of transform coding, which focuses on minimizing the MSE of transform coding. In the proposed codebook design approach, the quantization of an orthonormal matrix is carried out in the parameter space of GMRF, transforming the complex task of quantizing a large matrix with orthonormality constraints into a much simpler task of vector quantization in a reduced-dimensional space. A very important advantage of the proposed method is that it can be easily used to design transforms for variable block-size adaptive transform coding. Experimental results are presented for adaptive transform coding of still images which compares the proposed approach against various other alternatives recently reported in the literature. Finally, this thesis addresses the problem of predictive quantization of a random orthonormal matrix process. While predictive quantization is commonly used to quantize correlated processes in Euclidean space, these methods are not directly applicable to processes on a manifold. The approach proposed in this thesis views the prediction problem as one of tracking KLT matrices on the orthonormal matrix manifold. A definition for matrix prediction error on the manifold is proposed. Numerical results demonstrate the effectiveness of utilizing predictive quantization of transform matrices to improve transform coding gain.
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Open Access
Environmental assessment and impact of air, water and noise levels near a cement factory in Ewekoro, Ogun State, Nigeria
(2024-09-15) Awos, Alaba; Zvomuya, Francis (Soil Science); Zhang, Qiang (Biosystems Engineering); Oludare, Adedeji (Federal University of Agriculture, Abeokuta Nigeria); Thompson, Shirley
The air, water and noise were assessed for respirable particulate matter (PM2.5 and PM10) and heavy metals (lead, chromium, nickel, cadmium, zinc and copper) and noise levels around a cement factory in Ewekoro. Air was sampled using a cassette sampler and was taken at Ewekoro and neighbouring communities (Papalantoro, Lapeleko and Itori) in Nigeria’s Ogun State. An atomic absorption spectrometer (AAS) measured heavy metals in the water, and a sound level meter was used to monitor the noise levels. Comparing levels with the World Health Organization (WHO), National Environmental Standard and Regulation Enforcement Agency guideline (NESREA, Nigeria) and Canadian Ambient Air Quality Standards (CAAQS) show some standards were exceeded. The mean concentrations of Cadmium (Cd), Chromium (Cr) and Nickel (Ni) in the air of the cement factory area and the impacted neighbourhoods were higher than the WHO/EU permissible limits. Chromium's hazard quotient (HQ) was above the WHO/EU safe level in adults and children through ingestion, inhalation and dermal contact in all areas monitored. Also, the HQ for Ni and Cd were higher than the safe levels in the cement factory area and Papalantoro but not in other areas, while Zinc (Zn) was determined to be at safe levels. All heavy metals monitored in the river water, except Zn, exceeded the WHO permissible limit. The heavy metal sources cannot be pinpointed to the cement factor as other points and non-point contamination sources exist. The hazard index (HI) was greater than one in all the rivers monitored in children and adults, signifying an unacceptable health risk for non-carcinogenic effects. The HI for children in all the rivers sampled was higher than that for adults, indicating that children will experience more non-carcinogenic health risks than adults. The sum of Incremental lifetime cancer risk (∑ILCR) of both adults and children was higher than the acceptable level. The highest daily noise level result at the cement factory was below the NESREA regulatory standard, while the result at the residential area was slightly higher than the standard.
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Open Access
A systematic review protocol: health economic evaluations of immunotherapy and biologics for food allergy management
(2024-09-19) Fong, Andrew T.; Jacob, Joshua; Protudjer, Jennifer L. P.; Lloyd, Melanie; Thyer, Liz; Hsu, Peter S.; Si, Lei
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Open Access
Incidence of serious infection among etanercept and infliximab initiators: safety comparison between biosimilars and bio-originators with Canadian population-based data
(2024-09-27) Birck, Marina G.; Lukusa, Luck; Choquette, Denis; Boire, Gilles; Maksymowych, Walter P.; Singh, Harminder; Afif, Waqqas; Bernatsky, Sasha
Abstract Background Safety remains a significant concern for biologic drugs, and studies are needed to ensure a comparable safety profile for biosimilars and their legacy treatments. Using Canadian administrative health data from 2015–2019, we compared the incidence of serious infection between biosimilars and bio-originators initiators for etanercept and infliximab, two of the most commonly used biologics during this time. Methods We performed a retrospective cohort study using pan-Canadian data (except Quebec) from the National Prescription Drug Utilization Information System linked to hospitalization data. We studied new users of infliximab or etanercept (January/2015-December/2019) and compared incidence rates of serious infection, defined as those which required hospitalization, by using Cox regression models adjusted by biological sex, age at treatment initiation, prior corticosteroid or biologic, province, and calendar year. Results We studied 6,583 etanercept users (mean age 62) and 7,202 infliximab users (mean age 45). Hospitalization with infections occurred in 7% of infliximab and 2% of etanercept users. Comparing the risk of infection between biosimilar to bio-originator, the adjusted hazard ratio (95% confidence interval) was 1.33 (0.77, 2.30) for etanercept and 0.93 (0.72, 1.18) for infliximab. Conclusions Our study found no clear difference between etanercept and infliximab biosimilars and their bio-originators for infection incidence, suggesting a similar safety profile.
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Open Access
“We are an active family”: a randomized trial protocol to evaluate a family-system social identity intervention to promote child physical activity
(2024-09-27) Streight, Evangeline; Beauchamp, Mark R.; Smith, Kurt J.; Blanchard, Chris M.; Carson, Valerie; Strachan, Shaelyn M.; Vanderloo, Leigh M.; Courtnall, Sandy; Rhodes, Ryan E.
Abstract Background Regular engagement in moderate-to-vigorous physical activity (MVPA) during childhood yields a myriad of health benefits, and contributes to sustained MVPA behaviors into adulthood. Given the influence of parents on shaping their child’s MVPA behaviour, the family system represents a viable target for intervention. The purpose of this study is to compare the effects of two intervention conditions designed to increase child MVPA: (1) A standard education + planning intervention providing information about benefits, action planning, and coping planning; and (2) An augmented physical activity education + planning intervention that includes the components of the standard intervention, as well as a focus on family identity promotion and developing as an active member of the family. Methods A two-arm parallel single-blinded randomized trial will compare the two conditions over 6 months. Eligible families have at least one child aged 6–12 years who is not meeting the physical activity recommendations within the Canadian 24-Hour Movement Guidelines (i.e.,<60 min/day of MVPA). Intervention materials targeting family identity promotion will be delivered online via zoom following baseline assessment, with booster sessions at 6-weeks and 3-months. Child MVPA will be measured by wGT3X-BT Actigraph accelerometry at baseline, 6-weeks, 3-months, and 6-months as the primary outcome. At these same time points, parent cognition (e.g., attitudes, perceived control, behavioral regulation, habit, identity) and support behaviours, and parent-child co-activity will be assessed via questionnaire as secondary outcomes. Child-health fitness measures will be also administered through fitness testing at baseline and 6-months as secondary outcomes. Finally, upon completion of the trial’s 6-month measures, a follow-up end-of-trial interview will be conducted with parents to examine parents’ experiences with the intervention. Results So far, 30 families have been enrolled from the Southern Vancouver Island and Vancouver Lower Mainland area. Recruitment will be continuing through 2026 with a target of 148 families. Discussion This study will contribute to the understanding of effective strategies to increase child physical activity by comparing two intervention approaches. Both provide parents with education on physical activity benefits, action planning, and coping planning supports. However, one intervention also incorporates components focused on promoting an active family identity and involving all family members in physical activity together. The findings from this study have the potential to inform the design and implementation of public health initiatives aimed at improving physical activity participation in children and guide the development of more effective interventions that leverage the crucial role of parents and the family system in shaping children’s physical activity behaviors. Trial Registration The clinical trial registration ID is NCT05794789. This trial was registered with clinicaltrials.gov on March 2nd, 2023, with the last updated release on September 28th, 2023.
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Open Access
An open-label, parallel-group, randomized clinical trial of different silver diamine fluoride application intervals to arrest dental caries
(2024-09-04) Schroth, Robert J.; Bajwa, Sukeerat; Lee, Victor H. K.; Mittermuller, Betty-Anne; Singh, Sarbjeet; Cruz de Jesus, Vivianne; Bertone, Mary; Chelikani, Prashen
Abstract Background Silver diamine fluoride (SDF) is an antimicrobial agent and alternative treatment option that can be used to arrest dental decay. While there is optimism with SDF with regard to caries management, there is no true consensus on the number and frequency of applications for children. The purpose of this study was to examine the effectiveness of 38% SDF to arrest early childhood caries (ECC) at three different application regimen intervals. Methods Children with teeth that met International Caries Detection and Assessment System codes 5 or 6 criteria were recruited from community dental clinics into an open-label, parallel-group, randomized clinical trial from October 2019 to June 2021. Participants were randomized to one of three groups using sealed envelopes that were prepared with one of three regimens inside: visits one month, four months, or six months apart. Participants received applications of 38% SDF, along with 5% sodium fluoride varnish (NaFV), at the first two visits to treat cavitated carious lesions. Lesions were followed and arrest rates were calculated. Lesions were considered arrested if they were hard on probing and black in colour. Statistics included descriptive and bivariate analyses (Kruskal one-way analysis of variance and Pearson’s Chi-squared test). A p-value of ≤ 0.05 was considered significant. Results Eighty-four children participated in the study (49 males and 35 females, mean age: 44.4 ± 14.2 months). Treatment groups were well matched with 28 participants per group. A total of 374 teeth and 505 lesions were followed. Posterior lesions represented only 40.6% of affected surfaces. Almost all SDF treated lesions were arrested for the one-month (192/196, 98%) and four-month (159/166, 95.8%) interval groups at the final visit. The six-month group experienced the lowest arrest rates; only 72% (103/143) of lesions were arrested (p < 0.001). The duration of application intervals was inversely associated with improvements in arrest rates for all lesions. Conclusions Two applications of 38% SDF and 5% NaFV in one-month and four-month intervals were comparable and very effective in arresting ECC. Applications six months apart were less effective and could be considered inferior treatment. Trial registration ClinicalTrials.gov NCT04054635 (first registered 13/08/2019).
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Open Access
A randomized pragmatic feasibility trial to promote student perspective-taking on client physical activity level: a collaborative project
(2024-09-28) Hoplock, Lisa B.; Lobchuk, Michelle M.; Strachan, Shaelyn M.; Halas, Gayle; Olfert, Cheryl; Webber, Sandra; Parsons, Joanne L.
Abstract Background Health-care practitioners have opportunities to talk with clients about unhealthy behaviors. How practitioners approach these conversations involves skill to be effective. Thus, teaching health-care students to communicate empathetically with clients should promote effective client-practitioner conversations about health behavior change. The primary objective of this pilot trial was to assess the feasibility, acceptability, and appropriateness of a theoretically informed intervention designed to improve perspective-taking. Methods For inclusion in this randomized mixed-methods parallel two-arm trial, participants needed to be a student at the investigators’ Canadian university and have completed course content on behavior change communication. Using a 1:1 allocation ratio, participants in Respiratory, Physical, and Occupational Therapy; Nurse Practitioner; and Kinesiology programs were randomly assigned to full or partial intervention conditions. Full intervention participants completed a perspective-taking workshop and practiced perspective-taking prior to an in-lab dialogue with a client-actor (masked to condition) about physical activity. Partial intervention participants received the workshop after the dialogue. We assessed feasibility and appropriateness by comparing recruitment rates, protocol, and psychometric outcomes to criteria. We assessed acceptability (secondary outcome) by analyzing exit interviews. Results We screened and randomized 163 participants (82 = full intervention; 81 = partial intervention). We fell slightly short of our recruitment success criteria (10–15 participants per program) when 2/50 Occupational Therapy students participated. We met some but not all of our protocol criteria: Some full intervention participants did not practice perspective-taking before the dialogue, because they did not see anyone during the practice period or did not have a practice opportunity. Psychometric outcomes met the criteria, except for one measure that demonstrated ceiling effects and low reliability (Cronbach’s alpha < .70). There were no adverse events related to participation. Conclusions The intervention should be largely feasible, appropriate, and acceptable to deliver. We suggest changes that are large enough to warrant conducting another pilot study. We outline recommended improvements that are applicable to researchers and educators interested in recruitment, adherence to home practice, and online uptake of the intervention. Trial registration This trial was registered retrospectively on November 8, 2023, at https://clinicaltrials.gov/study/NCT06123507 .
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Open Access
Views and perspectives toward implementing the Global Spine Care Initiative (GSCI) model of care, and related spine care program by the people in Cross Lake, Northern Manitoba, Canada: a qualitative study using the Theoretical Domain Framework (TDF)
(2024-09-17) Robak, Nicole; Broeckelmann, Elena; Mior, Silvano; Atkinson-Graham, Melissa; Ward, Jennifer; Scott, Muriel; Passmore, Steven; Kopansky-Giles, Deborah; Tavares, Patricia; Moss, Jean; Ladwig, Jacqueline; Glazebrook, Cheryl; Monias, David; Hamilton, Helga; McKay, Donnie; Smolinski, Randall; Haldeman, Scott; Bussières, André
Abstract Background Back pain is very common and a leading cause of disability worldwide. Due to health care system inequalities, Indigenous communities have a disproportionately higher prevalence of injury and acute and chronic diseases compared to the general Canadian population. Indigenous communities, particularly in northern Canada, have limited access to evidence-based spine care. Strategies established in collaboration with Indigenous peoples are needed to address unmet healthcare needs, including spine care (chiropractic and movement program) services. This study aimed to understand the views and perspectives of Cross Lake community leaders and clinicians working at Cross Lake Nursing Station (CLNS) in northern Manitoba regarding the implementation of the Global Spine Care Initiative (GSCI) model of spine care (MoC) and related implementation strategies. Method A qualitative exploratory design using an interpretivist paradigm was used. Twenty community partners were invited to participate in semi-structured interviews underpinned by the Theoretical Domains Framework (TDF) adapted to capture pertinent information. Data were analyzed deductively and inductively, and the interpretation of findings were explored in consultation with community members and partners. Results Community leaders (n = 9) and physicians, nurses, and allied health workers (n = 11) emphasized: 1) the importance of contextualizing the MoC (triaging and care pathway) and proposed new services through in-person community engagement; 2) the need and desire for local non-pharmacological spine care approaches; and 3) streamlining patient triage and CLNS workflow. Recommendations for the streamlining included reducing managerial/administrative duties, educating new incoming clinicians, incorporating follow-up appointments for spine pain patients, and establishing an electronic medical record system along with a patient portal. Suggestions regarding how to sustain the new spine care services included providing transportation, protecting allocated clinic space, resolving insurance coverage discrepancies, addressing misconceptions about chiropractic care, instilling the value of physical activity for self-care and pain relief, and a short-term (30-day) incentivised movement program which considers a variety of movement options and offers a social component after each session. Conclusion Community partners were favorable to the inclusion of a refined GSCI MoC. Adapting the TDF to unique Indigenous needs may help understand how best to implement the MoC in communities with similar needs.
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Open Access
Updates on CAR T cell therapy in multiple myeloma
(2024-09-12) Nasiri, Fatemeh; Asaadi, Yasaman; Mirzadeh, Farzaneh; Abdolahi, Shahrokh; Molaei, Sedigheh; Gavgani, Somayeh P.; Rahbarizadeh, Fatemeh
Abstract Multiple myeloma (MM) is a hematological cancer characterized by the abnormal proliferation of plasma cells. Initial treatments often include immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and monoclonal antibodies (mAbs). Despite salient progress in diagnosis and treatment, most MM patients typically have a median life expectancy of only four to five years after starting treatment. In recent developments, the success of chimeric antigen receptor (CAR) T-cells in treating B-cell malignancies exemplifies a new paradigm shift in advanced immunotherapy techniques with promising therapeutic outcomes. Ide-cel and cilta-cel stand as the only two FDA-approved BCMA-targeted CAR T-cells for MM patients, a recognition achieved despite extensive preclinical and clinical research efforts in this domain. Challenges remain regarding certain aspects of CAR T-cell manufacturing and administration processes, including the lack of accessibility and durability due to T-cell characteristics, along with expensive and time-consuming processes limiting health plan coverage. Moreover, MM features, such as tumor antigen heterogeneity, antigen presentation alterations, complex tumor microenvironments, and challenges in CAR-T trafficking, contribute to CAR T-cell exhaustion and subsequent therapy relapse or refractory status. Additionally, the occurrence of adverse events such as cytokine release syndrome, neurotoxicity, and on-target, off-tumor toxicities present obstacles to CAR T-cell therapies. Consequently, ongoing CAR T-cell trials are diligently addressing these challenges and barriers. In this review, we provide an overview of the effectiveness of currently available CAR T-cell treatments for MM, explore the primary resistance mechanisms to these treatments, suggest strategies for improving long-lasting remissions, and investigate the potential for combination therapies involving CAR T-cells.