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Yellow field pea and hemp protein hydrolysates as tools to enhance the health benefits and sensory quality of meat alternatives
No full textProtein hydrolysates are known to exert positive impact on human health and are useful in managing negative health conditions. This study produced enzymatic protein hydrolysates from hemp and pea, using papain and chymotrypsin, followed by incorporation into soybean-based meat analogues (MAs). The hydrolysates, hemp papain (HP), hemp chymotrypsin (HC), pea papain (PP) and pea chymotrypsin (PC) were used at the ratio of 8, 16 and 24% (w/w) of the soy protein concentrate (SPC) to develop MAs. The extruded MAs were tested for antioxidant, textural, bitterness intensity and in vitro bioactive properties. All the MAs had DPPH and metal chelating (MC) activities higher than their individual hydrolysates. The MC activities of the MAs were reduced with increasing hydrolysate content. SPC+8%HC and SPC+8%PP had the highest MC activity (42.99%) and were not significantly different from each other. However, all the hydrolysates had higher superoxide activities than their MAs, with the PP having the highest activity (35.43%) while SPC+16%HP had the highest hydroxyl radical scavenging activity (52.64 %). There were no significant differences in the α-amylase and α-glucosidase activities of the pea hydrolysates and their respective MAs, but the hemp hydrolysates had higher activities than their MAs. The hydrolysates had lower ACE inhibitory activities when compared to their MAs with SPC+8%HP having the highest inhibition (84.14%). The MAs had decreased hardness as the hydrolysates content increased while bitterness intensity was greater for the hydrolysates. The MAs that contained protein hydrolysates showed different variabilities in their cutting forces in both longitudinal and transverse directions, however, they all exhibited good cutting forces relative to the MA that contained only SPC. All the MAs had higher acetylcholinesterase (AChE) inhibitory activity than galantamine (AChE inhibitor drug), however, those made with pea protein hydrolysates showed better inhibition than the MAs that contained hemp hydrolysates. Results from this study indicate the potential use of plant-based protein hydrolysates to enhance the sensory and health-promoting properties of MAs.October 202
Regulation of oxidative stress and inflammation in gut health
Get PDFThe gastrointestinal tract plays an essential role in maintaining overall health. It is vulnerable to oxidative stress that disrupts intestinal integrity, promotes inflammation, and impairs nutrient absorption. Oxidative stress is an imbalance between reactive oxygen species production and antioxidant defense. Glutathione (GSH) is a potent endogenous antioxidant that plays a crucial role in maintaining redox homeostasis and protecting intestinal cells from oxidative damage. The mechanisms by which oxidative stress affects gut health remain poorly understood. This research aimed to examine the impact of oxidative stress on gut health and the underlying mechanisms; and to explore whether dietary fiber and probiotics could alleviate oxidative stress and improve gut health. Study Ⅰ evaluated the effects of high- and low-fiber diets on intestinal oxidative stress in growing-finishing pigs. Compared to the low-fiber diet, the high-fiber diet significantly reduced intestinal oxidative stress biomarkers and improved growth performance. Study Ⅱ examined the effect of E. coli infection on intestinal oxidative stress and the mechanisms involved in post-weaning piglets. E. coli infection is a major cause of post-weaning diarrhea in piglets. E. coli infection suppressed nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, reduced glutathione-synthesizing enzyme expression, and depleted serum and intestinal GSH level, decreased tight junction protein expression, increased intestinal permeability and elevated proinflammatory cytokines expression. Antibiotic treatment alleviated these effects. Supplementation with GSH restored Nrf2 expression, reduced proinflammatory cytokine expression, and mitigated epithelial oxidative damage. Study Ⅲ investigated the effects of probiotic Bacillus licheniformis HG76 on E. coli-induced oxidative stress in post-weaning piglets. The probiotic restored serum and intestinal GSH levels and nuclear Nrf2 expression, upregulated glutathione-synthesizing enzymes expression, and reduced lipid peroxidation. It also enhanced tight junction protein expression and lowered proinflammatory cytokine expression. In conclusion, these studies demonstrate that oxidative stress contributes to intestinal dysfunction by suppressing Nrf2 activation and GSH biosynthesis, leading to impaired gut health and growth performance. Dietary fiber and probiotics can enhance antioxidant capacity and maintain intestinal redox balance, thereby serving as effective strategies to mitigate oxidative damage and improve gut health in swine production.October 202
Herbivory resistance and leaf nutritional quality of hybrid poplar (Populus deltoides × petrowskyana) × petrowskyana exposed to salinity and Orgyia leucostigma
Get PDFWhen plants encounter salinity and herbivory simultaneously, these stress factors may interact synergistically or antagonistically due, among other things, to crosstalk between signaling pathways involved in the response to each factor. Although the effects of salinity and herbivory have been widely examined independently, their interactive or sequential impacts remain poorly understood, particularly in woody species. This study investigated 1) how salinity affects nutritional quality of hybrid poplar (Populus ‘Okanese’) leaves and resistance to a generalist herbivore Orgyia leucostigma, and 2) how prior herbivory exposure modifies plant responses to subsequent salinity stress and insect feeding. Hybrid poplar cuttings were grown in soil under greenhouse conditions. In the first experiment, four-week-old cuttings were exposed to either 0 or 100 mM NaCl. After four weeks of salt treatment, total phenolic content was higher in salt-treated plants, yet it was not affected by herbivory. Salinity led to higher concentrations of Na and Cl in the leaves, while macronutrients such as K, P, and S showed lower levels, changing leaf nutritional quality. However, constitutive and induced resistance to O. leucostigma were both unaffected by salinity or its interaction with herbivory, and overall resistance remained consistently high across all treatments. After two additional weeks of salt treatments, leaf Na and Cl levels increased by seven- and two-fold respectively. In addition, induced resistance was greater in salt-grown plants. In the second experiment, plants were first subjected to herbivory and then to salinity for four weeks. Plants previously exposed to herbivory had lower level of leaf phenolics compared to non-herbivory controls and salinity did not alter this response. However, plants grown in salinity had lower total soluble protein concentrations. Neither macronutrient nor micronutrient concentrations were significantly affected by salinity, herbivory, or their interaction and induced resistance to O. leucostigma was not affected by previous herbivory or subsequent salinity. Overall, a longer exposure (six weeks) to salinity enhanced induced resistance to the herbivore, but previous herbivory did not improve the responses of hybrid poplar to salinity and no synergistic effects between the two stresses were observed.University of ManitobaFebruary 202
Development of high rut-resistant asphalt mixes for municipal pavements
Get PDFRutting is a major form of pavement distress, particularly at intersections and bus stops, where slow-moving and frequent stopping and accelerating vehicular loads accelerate surface deformation. In these locations, asphalt mixes often fail due to low stiffness. The contributing factors are rounded aggregates that weaken the aggregate skeleton, excessive fines, high binder content, and inadequate compaction. Since these high-stress areas experience traffic loads different from those in general roadway sections, standard pavement materials may not provide sufficient strength and durability. To address this challenge, the study focused on the development of high rut-resistant Hot Mix Asphalt (HMA) mixtures specifically designed for heavy-duty municipal pavements. The research emphasizes optimizing material selection, aggregate gradation, binder properties, and mix design parameters to enhance the structural integrity and durability of asphalt under high traffic loads.
As part of this study, aggregates from multiple sources were assessed based on angularity, abrasion resistance, and water absorption, with highly angular aggregates selected to enhance the internal structure of the mix. A 12.5 mm Nominal Maximum Aggregate Size (NMAS) laboratory mix was designed using the selected aggregates and a 64-34P asphalt binder, with the Bailey method applied to optimize aggregate packing and improve stability. In addition to the laboratory-designed mix, five plant-produced mixes were collected from three City of Winnipeg pilot projects: two 12.5 mm NMAS Superpave surface course (SP1) mixes and three 19 mm NMAS binder course (SP2) mixes. Together, these six mixes formed the test matrix for performance evaluation. Each mix was tested for rutting resistance using the Hamburg Wheel Tracking Test (HWTT), moisture sensitivity through the Tensile Strength Ratio (TSR), and stiffness performance using the Dynamic Modulus Test (DMT).
Results showed that the laboratory-produced SP1 and Project 3 mixes demonstrated high rutting resistance. They satisfied the minimum TSR requirement of 80%. At the same time, Project 1 mixes also showed superior rutting resistance and still met the minimum Indirect Tensile Strength (ITS) criterion, despite failing to comply with the minimum 80% TSR requirement. In contrast, Project 2 mixes exhibited poor rutting resistance, with Project 2 SP2 exceeding the 14 mm rut depth limit at 20,000 passes, a deficiency linked to lower Fine Aggregate Angularity (FAA) and inferior volumetric properties. Correlation analysis revealed that VMA and effective binder content strongly influenced rutting performance, while TSR values correlated positively with asphalt content and VMA, emphasizing the need for a balanced aggregate-binder structure. However, weak correlations between HWTT, TSR, and DMT highlight the limitations of relying solely on moisture sensitivity or stiffness tests for mix evaluation.
The findings suggest that rut-resistant mixes can be realistically achieved by optimizing volumetric properties, using angular aggregates with controlled gradation, and incorporating polymer-modified binders. Moreover, adopting the Bailey Method for gradation checks and incorporating performance-based specifications, similar to practices in municipalities such as Edmonton and Toronto, would significantly enhance Winnipeg’s mix design framework. Finally, integrating low-temperature cracking tests and long-term field evaluations is recommended to ensure durability under the city’s harsh freeze-thaw climate. Together, these insights provide a practical pathway toward designing more durable and rut-resistant municipal pavements.February 202
End-to-end design and experimental evaluation of a PIN diode-based reconfigurable reflective metasurface
Get PDFMetasurfaces are thin structures composed of arrays of subwavelength unit cells that can collectively manipulate an incoming electromagnetic wave into a desired outgoing wave. Their functionality becomes especially powerful when unit cells are reconfigurable through tunable electronic components, enabling a single metasurface to perform multiple programmable functions. For instance, employing 20 diodes within the metasurface (each either on or off) results in over one million possible wave transformation configurations. This MSc thesis contributes to (i) modeling, (ii) optimization, and (iii)~design and experimental evaluation of reconfigurable metasurfaces.
On the modeling side, unit cells were characterized by their surface properties, which served as inputs to a fast solver developed by our group to predict scattering responses of the reconfigurable metasurface. This solver employs the integral equation (IE) formulation with metasurface boundary conditions, known as the generalized sheet transition conditions (GSTCs). To the best of my knowledge, this was the first time that this particular solver, known as the implicit IE-GSTC method, was applied to reconfigurable metasurfaces. This method is significantly faster than full-wave commercial solvers, due to the clever approximations it employs, while retaining sufficient accuracy, which is advantageous given the large number of operating states.
On the optimization side, the challenge was to determine the biasing configurations that produce radiation patterns closest to a user-defined target. To address this, I incorporated a genetic algorithm to efficiently search the configuration space efficiently. Candidate solutions are evaluated using the implicit IE-GSTC method, assigned fitness scores, and evolved until converges.
On the hardware side, I optimized a binary reflective unit cell based on a previous design with near-optimal reflection magnitude and a phase difference close to 180 degrees between its two states. This reconfigurable metasurface was then fabricated by integrating copper patches, surface-mount components, and connectors for manual biasing control. Experimental validation was performed in the planar near-field antenna range. Early results confirm that the reflected fields are altered by the programmed biasing states, providing evidence that the framework successfully links simulation, optimization, and measurements.
In summary, this MSc thesis establishes an end-to-end design framework for reconfigurable reflective metasurfaces with binary unit cells and investigates the major stages of design flow along with their inter-dependencies.February 202
Belonging, community, and preparedness: teacher experiences of working and living in northern Manitoba
Get PDFRecruitment and retention of teachers have been continuing obstacles for school divisions in northern Manitoba. Teachers experience unique challenges when relocating and integrating into northern and remote communities. The aim of this qualitative study was to gain a deeper understanding of the experiences of teachers new to northern Manitoba, to help improve recruitment and retention strategies in this region of the province. Teacher preparedness for working in the North and a sense of belonging were also themes explored in this research. Understanding a teacher’s relationship to their school and their broader community was a focus to better understand the career decisions in this study (Janzen & Cranston, 2015).
The findings were presented to highlight the experiences and challenges participants faced in their first year of teaching in northern Manitoba. The results provided recommendations for school boards and school districts on how to revise their strategies for recruiting and retaining teachers. Additionally, suggestions were made for universities to better prepare teacher candidates for northern teaching roles.May 202
Design and experimental evaluation of a high-efficiency wireless EV charging system with aging- and tolerance-aware ZVS
Get PDFWireless Power Transfer (WPT) has gained significant attention as a promising technology for electric vehicle (EV) charging, offering convenience, safety, and the potential for
widespread adoption of electrified transportation. Achieving high efficiency and long-term reliability, however, remains a major challenge due to the strong dependence on coil design,
resonant compensation, and the robustness of soft-switching operation under component degradation. This thesis presents the design and experimental validation of a 2 kW series-compensated WPT system for EV charging applications. A systematic methodology was developed to optimize Archimedean spiral coil, focusing on maximizing power transfer efficiency while avoiding bifurcation. The proposed design approach is novel in that it simultaneously ensures high efficiency and bifurcation-free operation, enabling the selection of coil turn count and load resistance that achieve optimal performance under the provided design constraints. The 2 kW prototype was experimentally tested, demonstrating high efficiency and stable, bifurcation-free operation across the studied operating conditions. These results validate the effectiveness of the coil design methodology and highlight the advantages of the proposed approach compared with conventional design guidelines. The thesis specifically examines how capacitor aging and manufacturing tolerances affect
Zero-Voltage Switching (ZVS) and overall system efficiency. Experiments demonstrated that deviations in primary capacitance reduce the ZVS window and can lead to additional
switching losses if dead time is selected based only on nominal conditions. A dead-time selection strategy that accounts for these deviations—along with careful capacitor selection
to minimize tolerance and aging drift—was proposed and experimentally validated. This ensures that ZVS is preserved and high efficiency is maintained even as component values
shift over time. Overall, this work provides a practical framework for the design and experimental evaluation of efficient, bifurcation-free, and reliable WPT systems for electric vehicle charging, addressing both immediate performance optimization and long-term operational stability.February 202
Towards optimization of a chronic fecal-induced peritonitis murine model of sepsis to study long-term outcomes in preclinical research
Get PDFSepsis is defined as a “life-threatening organ dysfunction caused by a dysregulated host response to infection” with a high mortality rate, making it one of the leading causes of death worldwide. Advancements in treatments and interventions have significantly improved sepsis survival rates; however, discharge from the hospital marks the beginning of a longer road to full recovery. One such impairment is intensive care unit acquired weakness (ICU-AW), a condition characterized by muscle weakness in the limbs and respiratory muscles caused by the disease itself. This condition is becoming increasingly prevalent as sepsis survival rates improve. Although recovery from ICU-AW is possible, it remains unclear why some individuals continue to experience persistent symptoms despite rehabilitation efforts. We hypothesize that sustained microvascular dysfunction post-sepsis drives persistent weakness by limiting skeletal muscle function and recovery. To address this, we developed a 2-week fecal-induced peritonitis model of murine sepsis and characterized lasting affects of sepsis to address this association. Aspects such as disease severity, temperature, weight, bacterial cultures, blood gas analysis, and evaluation of inflammatory markers were assessed to evaluate the extent illness and systemic response to sepsis. Grip-strength testing was conducted to observe any changes in muscle strength, and immunohistochemistry analysis of muscle sections were performed to determine extent of atrophy and structural changes in capillary density. We found that there were elevated levels of endothelial cell (EC) adhesion markers still present in our 2-week septic mice despite having low levels of inflammatory cytokines and exhibiting no signs of illness in their blood plasma. Muscle atrophy was also evident as a decrease in muscle fiber cross-sectional area in the muscle of the septic mice in the 2-week model, however there was no change in the number of capillaries. Overall, our model effectively produced hallmarks of sepsis and some features of ICU-AW, revealing ongoing microvascular dysfunction and mild muscle weakness even after recovery. Further refinements to the model will enhance its translational relevance to identifying the mechanisms behind ICU-AW, guiding the development of more effective therapeutic strategies in the future.- Sepsis Canada Research Network
- Department of Internal Medicine at the University of Manitoba
- Research Manitoba New Investigator Operating Grant (grant ID #6408)February 202
Comparison of Intra-articular Injection of PRGF and Corticosteroid When Used as an Adjunct to Temporomandibular Joint Arthrocentesis: A Blinded Randomized Control Trial
Get PDFBackground: Intraarticular pain in dysfunction (IPD) is a notably prevalent condition affecting the temporomandibular joint. Both marcotrauma and microtrauma, from bruxism and parafunctional habits, can lead to internal derangement of the temporomandibular joint disc causing chronic inflammation and pain. Arthrocentesis is a surgical procedure used to reduce this inflammation and return the patient to painless function. Several drugs have been used as an adjunct to arthrocentesis. Research has suggested platelet concentrates may serve as a superior alternative supplement when used in combination with arthrocentesis from the treatment of IPD.
Objectives: To compare the clinical outcomes of platelet-rich in growth factor (PRGF) versus corticosteroid (CS) injections as adjuncts to temporomandibular joint (TMJ) arthrocentesis in patients with predominantly Wilkes stage II–III internal derangement.
Materials and Methods: This single-blinded randomized controlled trial included sixteen participants who underwent standardized unilateral TMJ arthrocentesis. Subjects were randomized to receive either intra-articular triamcinolone (40 mg) or PRGF (2 mL). Clinical outcomes—including maximum interincisal opening (MIO), average daily pain, maximum pain intensity, joint sounds, and muscle tenderness—were recorded preoperatively and at 7, 30, 90, and 180 days postoperatively.
Results: At 6 months, the CS group demonstrated a greater mean improvement in MIO (+7.0 mm) compared with PRGF (–8.6 mm). PRGF resulted in a significant reduction in average daily pain in the early follow-up period, however steroid provided similar early pain reduction, and improved long term pain reduction. Joint sounds and muscle tenderness declined slightly in both groups, with no significant differences between treatments.
Conclusion: Given the small sample size, higher attrition in the PRGF group, and lack of quality-of-life measures, findings should be interpreted with caution. Within these limitations, PRGF did not demonstrate superiority over corticosteroids as an adjunct to TMJ arthrocentesis.Foundation for Continuing Education and Research (CAOMS) Research Gran
Using computed tomography imaging to detect early implant migration in total knee replacement
Get PDFTotal knee replacement (TKR) surgery is a common procedure with increasing incidence. TKR implants can migrate due to postoperative loosening, which is associated with negative patient outcomes. Small implant movements can be measured postoperatively using image analysis, and have historically been measured via radiostereometric analysis (RSA) using planar X-ray. Computed tomography (CT)-based RSA (CT-RSA) is the latest technological development for tracking implant migration. CT-RSA is expected to replace traditional RSA methods as it does not require intra-operative marker beads or a specialized imaging setup, and has the potential to expand access to migration analysis. However, CT has a higher radiation dose compared to planar X-ray. Volumetric Matching Micromotion Analysis (V3MA) is a CT-RSA software recently developed in the Netherlands. V3MA relies on image registration to calculate implant migration, and is in the early stages of validation. The aim of this thesis was to validate V3MA for migration analysis of TKR implants in Canada. Specific objectives were to determine a reliable registration method for knee CT images, to determine the in vitro accuracy and precision of CT-RSA using V3MA, to determine the in vivo precision of CT-RSA using V3MA, and to assess sources of error in CT-RSA.Funding was received from the Concordia Hospital Foundation and the University of Manitoba.February 202