Development of biobased phenolic foams for floral, hydroponic and environmental remediation applications

Phenol formaldehyde (PF) foams have been widely utilized in various applications, including floral foam blocks, which have supported flower arrangements since the 1950s. However, the environmental impact of petroleum-based production, coupled with the depletion of non-renewable resources and fluctuating oil prices, has driven increasing interest in renewable alternatives for phenolic resin production. This study focuses on developing foamable biobased phenol formaldehyde (BPF) resins by substituting phenol with lignin derived from forestry residues at substitution levels of 30 wt% or higher. The resulting resins are used to produce hydrophilic phenolic foams with open-cell morphology, superior wetting properties, and acceptable mechanical characteristics, suitable for applications in floristry, hydroponics, and environmental remediation. Kraft lignin-substituted foams demonstrated remarkable hydrophilic properties, including near-complete open-cell porosity (~100%), a water absorption capacity of 2100%, and a water uptake rate of 0.9 cm³/s. These foams also exhibited biodegradability of approximately 68% within 15 days. Depolymerized Kraft lignin-substituted foams showed even greater water absorption capacities (up to 2557%), low densities (~62 kg/m³), near-complete open-cell content (~100%), and biodegradability of ~39% after 15 days when exposed to Bacillus sp.. Similarly, lignosulfonate-based foams achieved high water absorption capacities (2409%), rapid water uptake rates (1.53 cm³/s), near-complete open-cell content (~100%), and biodegradability of ~65% over 15 days under similar conditions. The synthesized foams were found to be comparable to commercially available petroleum-based floral and hydroponic foams in terms of hydrophilic properties and germination performance. Additionally, the research explores the application of these foams for environmental remediation, including adsorptive dye removal and phosphorus recovery, further enhancing their potential as sustainable, multifunctional materials

Process evaluation of the Hockey Fans in Training lifestyle intervention (for men with overweight or obesity).

BACKGROUND: Despite the proven relationship between lifestyle and morbidity and mortality, rates of chronic disease (e.g. obesity) continue to rise in paradox to the myriad of studies supporting lifestyle behaviour change. Men have been less likely to seek out preventative care or lifestyle programs, putting them at risk. In response, Hockey Fans In Training (Hockey FIT) was developed as a group-based, lifestyle intervention leveraging the draw of hockey fandom to engage middle-aged men with overweight or obesity in lifestyle change. Encouraging pilot study results informed the optimization and delivery of the intervention through a cluster randomized controlled trial in 42 sites in Canada and the USA. METHODS: A process evaluation was conducted to evaluate intervention acceptability and fidelity and adaptations. Community-based sites were randomly allocated to Hockey FIT intervention (immediate program start) or wait-list control (12-month delay). Qualitative process evaluation data were collected from intervention sites and included seven virtual participant focus groups and one interview (n = 35 participants), open-ended participant feedback questionnaires (n = 316), interviews with program coaches (n = 22), post-session coach reflections (n = 233), and interviews with implementation partners (n = 16). A process of content analysis by question was performed and data saturation was reached. RESULTS: Themes fell into the following categories: (i) motivations for joining Hockey FIT; (ii) effective program components; and (iii) adaptations and suggested improvements. CONCLUSIONS: The process evaluation detailed success engaging men in lifestyle change using sport fandom, and the importance of capitalizing further on competition within groups to drive behavioural change through user-friendly supports and greater engagement with hockey. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov. ID: NCT03636282

Investigating the Influence of Scale Cues and Pose Integration on AI-Based Monocular Depth Estimation for Resource-Constrained Mobile Robots

Depth estimation is crucial for robotic navigation, with monocular depth estimators providing cost-effective and accessible solutions. However, their accuracy can degrade in atypical camera poses. This thesis investigates a novel approach to addressing pose biases in AI-based monocular depth estimation by incorporating camera poses obtained using scale-aware feature extraction as an additional input parameter. The methodology encodes the front-facing camera pose of a rover as an additional input channel to a U-Net-based monocular depth estimator. The pose is extracted from images captured by a rear-facing camera, typically used for regolith tracking, using SIFT and RANSAC algorithms. Scaling is performed using known dimensions of objects in the rear view, followed by refinement with a particle filter. Different pose encoding techniques are analyzed, highlighting their potential to improve depth estimation accuracy while identifying key areas for further optimization

Can Fibrinogen Drive Microglia Dysfunction?

Disruption of the blood-brain barrier (BBB) contributes to cerebral small vessel disease (cSVD) by facilitating plasma protein extravasation, including fibrinogen. Fibrinogen activates microglia into a pro-inflammatory state via CD11b/CD18 signaling. However, the effects of prolonged fibrinogen exposure on microglial function remain unclear. This study is the first to develop an in vitro model for cSVD by culturing BV-2 microglia for 7 days to investigate the impact of prolonged fibrinogen exposure, simulating conditions of chronic BBB disruption. The results demonstrated that repeated fibrinogen exposure induced sustained inflammation, oxidative stress, and a senescence-like phenotype in BV-2. Interestingly, prolonged in vitro culture alone resulted in dysfunction characterized by impaired mitochondrial function and senescence markers. This suggests that extended culture conditions can mimic aging-like effects on microglia. These findings highlight the dual impact of fibrinogen exposure and prolonged culture duration on microglial function, providing new insights for future studies on microglial dysfunction in cSVD

Development and Evaluation of ‘High Alert’, A Brief Smartphone Intervention to Reduce Cannabis-Impaired Driving Among Canadian Youth

Young drivers in Canada report the highest rates of cannabis use and impaired driving while expressing the least concern toward driving under the influence of cannabis (DUIC). Since cannabis increases crash risk, preventing youth from DUIC remains a top public health priority. This dissertation aimed to apply the six-step Intervention Mapping framework to develop, implement, and evaluate a brief smartphone intervention called High Alert, designed to reduce DUIC among high-risk youth in Ontario. In Study 1, the first four steps of Intervention Mapping were applied to systematically develop High Alert while integrating evidence, theory, and user feedback. This process involved conducting a needs assessment (Step 1), identifying intervention objectives (Step 2), selecting theory-based methods and practical strategies (Step 3), and creating intervention components and materials (Step 4). The program was pre-tested with five youth and five adult cannabis educators, and their feedback informed refinements before pilot testing. Study 2 applied Step 5 to pilot test High Alert’s implementation and preliminary efficacy through a three-arm pilot randomized controlled trial involving 102 Ontario youth with recent DUIC (≥3 instances in the past 3 months). Findings reveal that High Alert participants exhibited the greatest mean reductions in DUIC compared to both the active and passive control groups. These reductions were statistically significant when comparing all DUIC instances to the passive control, but not for the active control. No significant differences were observed in risky cannabis use. These findings suggest High Alert’s potential to reduce DUIC, warranting further investigation. Finally, Study 3 evaluated High Alert using Step 6, incorporating formative, process, outcome, and acceptability evaluations. While High Alert significantly increased DUIC knowledge and expectations of reducing DUIC compared to the active control, and received better engagement and acceptability scores, no significant differences emerged in other behavioral determinants. Process evaluations highlighted challenges in recruitment, retention, adherence, and measurement, offering insights to inform future trials. Overall, this dissertation highlights High Alert’s potential as a youth DUIC intervention and provides crucial guidance for advancing DUIC research to improve youth road safety

Characterization of Metal-organic Frameworks via Wideline and High-resolution Solid-state NMR Spectroscopy

Metal-organic frameworks (MOFs) are a class of porous materials composed of metal centers and organic linkers. MOFs have diverse applications, including gas storage/separation, catalysis and energy storage, due to their unique properties such as high specific surface area, tunable topologies and good stabilities. Understanding the relationship between MOF structure and properties is crucial for enhancing performance and developing new materials. In this thesis, solid-state NMR (SSNMR) spectroscopy combined with theoretical calculations have been utilized to characterize the local structure of MOFs and adsorbed guest molecules. In the first part of this thesis, the local structures of several representative MOFs were studied with wideline NMR. The local environments of Cu(I) ions in Cu-MOFs regarding the coordination numbers, phase changes, oxidation states, and anion exchanges, were characterized using 63/65Cu SSNMR. The Zr centers in Zr-MOFs were examined with 91Zr SSNMR at high magnetic field of 35.2 T and 19.6 T, providing insights into the local site symmetry and short-range ordering around Zr centers. 91Zr NMR is very sensitive to structural variations in MOFs caused by guest molecules, linker substitution, and post-synthetic treatments. The 209Bi and 127I SSNMR spectra of bismuth- and iodine-containing MOFs were acquired at magnetic fields up to 36 T, with breadths ranging from 8 to 50 MHz, pushing the boundaries of ultra-wideline NMR. Cl-containing MOFs with different metals and organic linkers were studied with 35Cl SSNMR. The correlation between 35Cl NMR parameters and both local bond lengths and bond angles were obtained. 35Cl SSNMR was also used to identify an unknown product from chemical reactions. MOFs can be tailored for applications such as Xe and Kr separation. The co-adsorption behavior of Xe and Kr in five MOFs including the adsorption locations, binding strength, guest-host interactions and exchange dynamics was investigated with 129Xe and 83Kr SSNMR aided by molecular simulations. The second part of this thesis features two examples of high resolution SSNMR applied to MOFs. (i) We demonstrate that combining new cryogenic MAS probe technology and performing NMR experiments at a high magnetic field leads to significant signal enhancement for 67Zn SSNMR. The multiple non-equivalent Zn sites with very similar local environments in two MOFs, ZIF-4 and α-Zn3(HCOO)6, were well-resolved by natural abundance 67Zn 3QMAS NMR technique. (ii) The structure of a defective MOF MIL-120(Al) was investigated by multinuclear (1H, 13C, and 27Al) SSNMR spectroscopy. The local structure around defective Al sites was directly probed by 27Al 1D and 3QMAS NMR

Northern Tornadoes Project. Annual Report 2024

The Northern Tornadoes Project (NTP) 2024 Annual Report provides a comprehensive overview of the project\u27s operations, research, and findings over the past year. In 2024, NTP continued its mission to improve tornado detection, documentation, and public awareness across Canada. A significant milestone was the establishment of the Canadian Severe Storms Laboratory (CSSL) at Western University, supported by a $20 million contribution from ImpactWX. The CSSL serves as a hub for severe storm research and data collection, integrating multiple projects, including NTP, the Northern Hail Project, and the newly launched Northern Mesonet Project. Key advancements in 2024 included the release of a new tornado dataset (1980–2023) and an Advanced Dashboard for detailed event analysis. NTP recorded 129 tornadoes and 86 downbursts, utilizing ground surveys, high-resolution drone and satellite imaging, and crowdsourced data. Notably, four billion-dollar storms struck Canada, including a record-breaking GTA flash flood and a potential fire tornado in Jasper, AB. Additionally, the Michael Newark Digitized Tornado Archive was launched, preserving historical tornado records. With increased media engagement and scientific publications, NTP remains a leader in severe storm research. Moving forward, the project aims to refine detection methodologies and enhance public safety efforts through data-driven insights

“My child is completely underestimated”: Canadian parents’ perspectives on implementing an accessible language comprehension assessment for non-speaking children with cerebral palsy

Purpose: Reliable assessment of language comprehension is difficult for children with significant speech and motor limitations. The Computer-Based instrument for Low motor Language Testing (C-BiLLT) was designed for children with cerebral palsy (CP) and speech and motor limitations. A Canadian English version (C-BiLLT-CAN) has been validated. However, early investigation identified feasibility challenges necessitating further exploration. This study aimed to understand parents’ perceived barriers and facilitators to implementing the C-BiLLT-CAN in the Canadian clinical context. Materials and methods: Seven focus groups were conducted synchronously online with 16 parents from five Canadian provinces/territories. Transcripts were analyzed using semi-deductive thematic analysis, framing results within the Consolidated Framework for Implementation Research (CFIR). Results: Parents unanimously expressed interest in making the C-BiLLT-CAN clinically available. Facilitators and barriers were discussed under five themes. Key facilitators included the unique design, standardized nature, and potential flexibility of the C-BiLLT-CAN. Barriers involved the inability to accommodate all children, potential for unintended assessment impacts, and clinics’ readiness and willingness to prioritize implementation. Conclusions: This study contributes new knowledge surrounding the assessment needs of parents of children with CP and speech and motor limitations. Alongside findings from a parallel clinician study, results will inform adaptations to the C-BiLLT-CAN to facilitate implementation

Prothrombotic Mechanisms of Lp(a)-Mediated Pathophysiology: Implications for Platelet Function, Fibrin Clot Architectures, and Atherothrombosis

Elevated levels of lipoprotein(a) (Lp(a)) are an independent and causal risk factor for the development of atherothrombotic diseases. However, it is unknown if Lp(a) directly promotes thrombus formation, inhibits thrombus clearance, or merely accelerates the underlying atherosclerotic processes that culminate in plaque rupture. Similarities between the apolipoprotein(a) (apo(a)) component of Lp(a) with the fibrinolytic proenzyme plasminogen are strongly suggestive of antifibrinolytic activity. While numerous studies indicate that apo(a) can inhibit plasminogen activation and fibrinolysis, existing evidence suggests that these effects may not be retained in Lp(a). An alternative mechanism through which Lp(a) may promote atherothrombotic events is by impacting platelet function. Corroborating this notion, recent observational clinical studies demonstrated that individuals with high Lp(a) levels derive increased benefit from dual anti-platelet therapy. However, the effects of Lp(a) on platelet function and thrombosis have never been directly assessed in blood clots formed from flowing whole blood. In our first set of experiments, we used ex vivo plasma clot lysis assays to elucidate the previously reported disparities between the antifibrinolytic effects of Lp(a) and apo(a). In these studies, we showed that the residue in apo(a) responsible for mediating its antifibrinolytic effects appears to become functionally blocked during covalent Lp(a) assembly. Next, we evaluated the prothrombotic potential of Lp(a) in human blood clots formed under arterial flow conditions using a Chandler loop apparatus. In these studies, we showed that the presence of Lp(a) during thrombogenesis promoted platelet accumulation and facilitated the development of fibrin networks that displayed features of fibrinolysis resistance. Finally, we examined the prothrombotic potential of Lp(a) in vivo using established murine models of thrombosis and hemostasis. In the absence of underlying cardiovascular disease, we showed that mice expressing human apo(a) had increased thrombus volumes, and accelerated rates of vessel occlusion and hemostasis. Importantly, we also demonstrated that the observed prothrombotic effects of Lp(a) could be mitigated by low-dose aspirin therapy. Collectively, this body of work offers novel insights into the pathophysiological mechanisms of Lp(a), and suggests that, rather than inhibiting plasminogen activation, Lp(a) contributes to atherothrombotic diseases by exerting direct prothrombotic effects on platelet function and developing fibrin networks

Continuum Robotics, Haptics, and Teleoperation for Medical Applications

Recent advancements in robotics have opened new opportunities for medical applications, particularly in minimally invasive surgery (MIS) and therapeutic rehabilitation. Many studies have confirmed the benefits of robotics in surgery, leading to increased adoption of robotic solutions for medical applications and the corresponding industrial sectors. Medical robotics enhances the surgeon\u27s dexterity, offers superior precision, improves the surgical team\u27s ergonomics, and enables innovative procedures that are not feasible with traditional techniques. Robotic technologies have demonstrated significant potential to improve healthcare outcomes, contributing to higher patient survival rates and an enhanced quality of life. This study encompasses a broad range of technologies and applications, including the design and development of continuum robots for MIS and haptics-enabled bilateral teleoperation systems to enhance teleoperated medical procedures. While the literature discusses various applications of tendon-driven continuum robots (TDCRs) and concentric tube robots (CTRs), several challenges remain unresolved. These include (a) the absence of control-oriented models for TDCR dynamics; (b) the lack of feasible solutions for controlling the dynamics of TDCR; (c) the fact that many CTR and TDCR designs are still at the research stage, rendering them unsuitable for clinical applications; and (d) the limited exploration of procedure-specific autonomous deployment and navigation for CTRs. Furthermore, there are several unresolved issues in the haptics domain that have not been thoroughly addressed. For instance, (a) while solutions exist to ensure the stability of delayed bilateral teleoperation, the impact of delay on transparency is often overlooked; (b) electroadhesive semi-passive actuators have been introduced for safe human-robot interactions; however, various challenges related to their development, including performance degradation, adjustability, modeling, and control, have yet to be investigated. These challenges have motivated the research presented in this study, which aims to address the gaps through novel designs, modeling techniques, and control strategies. A part of this work presents the design of a robotic-actuated, steerable cardiac catheter, along with a novel control-oriented approach based on the deep Koopman approach to model the dynamics of the catheter, which is classified as a TDCR. The proposed method offers a globally linear model, facilitating the implementation of a task-space linear position control of the distal end of a catheter. Additionally, we explore a method for minimally invasive kidney stone removal through percutaneous nephrolithotomy (PCNL). A compact, hand-held CTR specifically engineered for PCNL has been designed and developed. We have implemented a closed-loop task-space position control of the distal end of the CTR. The effectiveness of the proposed robot has been experimentally validated using a soft abdominal phantom. Following a skin puncture, the robot autonomously navigates within the internal collecting system of the kidney to target the virtual stone based on planning using operative imaging. The next phase of this study focuses on advancing haptics-enabled teleoperation, with the goal of enhancing transparency in bilateral teleoperation systems. A delay compensator is introduced, which decomposes the force feedback signal on the follower side using a Fourier linear combiner. The resulting decomposed weights are then used on the leader side to reconstruct the undelayed signal. Closed-loop stability of the system is ensured through the well-established passivity assumption. The proposed platform is subjected to experimental evaluation in a bilateral teleoperation setup using a rehabilitation robot and a haptics robot. Additionally, we designed and developed a rotary electroadhesive clutch for human-safe, haptics-enabled systems. The electric field is modulated using both electrical and mechanical strategies to address the issue of electroadhesion degradation. The effectiveness of the clutch is validated through haptics-based experiments that involve creating appropriate virtual environments. The research outcomes featured various robotic technologies to enhance surgical precision, autonomy, and teleoperation clarity, setting the stage for future innovations in the field