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Aubigny’s Métis and French-Canadian founding families based on its Catholic registries
Get PDFThis thesis is a microhistory focusing on the families found in the registries of the French-Canadian parish of Aubigny in Manitoba; where they came from and what could be understood of the kinship ties evident in the data. It distinguishes categories of settlers including Métis families and francophone families from the United States and Quebec and relies on family reconstitution methods to better make use of the primary source. The registries show how kinship is an aid to settlement and persistence, how marriages create new ties in the community, and how godparenting roles reveal both matrilineal kinship and the presence or absence of rapport between families in the established categories. In addition, use of various databases and newspaper archives trace an outline of families’ political involvement, previous employment, and immigration routes. This work renders a high-definition picture of a very small community, serving to complement or contrast the beginnings of other rural parishes.February 202
Characterization of V3 interneuron firing patterns during rhythmic locomotor-like ventral root activity
Get PDFV3 interneurons (INs) are a genetically defined population of glutamatergic spinal neurons implicated in regulating the robustness of locomotion. Previous studies using computational modeling have postulated that V3 INs play a critical role in maintaining robust, coordinated alternation during rhythmic motor output. However, to date, no studies have directly recorded from identified V3 INs during rhythmic locomotor-like activity in the mammalian spinal cord. Therefore, the purpose of this study is to characterize the intrinsic electrophysiological properties and activity patterns of V3 INs during rhythmic motor activity using whole-cell patch-clamp (WCPC) recordings in Sim1Cre/TdTomato P1–P5 mouse spinal cord preparations. Electrophysiological recordings were preformed prior to and during pharmacologically induced tonic and rhythmic locomotor like ventral root (VR) activity via perfusion of serotonin (5-HT) and N-methyl-D-aspartate (NMDA). Analysis to date indicate that most V3 INs are quiescent at baseline, although some demonstrate spontaneous activity. Variable responses were recorded from V3 INs during drug evoked tonic VR activity. Specifically, following 5-HT and NMDA application and the emergence of tonic VR activity, most V3 INs recorded to date displayed an increase in excitability. This was characterized by a depolarized resting membrane potential and an increased firing rate correlating with the onset of tonic activity in VR recordings. Conversely, some V3 INs demonstrated decreased activity during drug evoked tonic VR activity, suggesting functional diversity within the recorded V3 INs. Similarly, V3 INs recorded during rhythmic VR activity also appeared to be tonic. However, due to our limited sample size, future research should aim to examine a larger sample and record V3s in a wider range of spinal segments to determine whether the observed pattern of firing during drug evoked locomotor activity is a more widespread phenomena/characteristic. These findings will provide critical insights into the cellular mechanisms and contributions of V3 INs to the generation and modulation of spinal locomotor circuits.February 202
Designing cell and protein-based DON biosensors for use in investigating DON-biotransforming microbes
Get PDFFusarium head blight (FHB) poses a major threat to small-grain cereals, reducing yield, quality,
and contaminating grains with the mycotoxin deoxynivalenol (DON). Once contaminated, it is
difficult and costly to remove DON from grains. New rapid and low-cost assays for detecting the
presence of DON are needed in order to screen for novel DON biotransforming microbial strains.
This thesis develops and evaluates two novel biosensors for detecting DON: a cell-based
Escherichia coli biosensor with a GFP reporter and a protein-based sensor engineered from
Fusarium graminearum acetyltransferase TRI101.
The Horizon Discovery E. coli Promoter Collection was screened using fluorescence-activated
cell-sorting, followed by sequencing and fluorescence plate assays for DON-responsive strains.
Strain rmf (ribosome modulation factor) exhibited a reproducible increase in fluorescence (~1.3
1.4× increase) when incubated in the presence of DON. Re-engineering this strain with the
brighter GFP variant mClover3 improved peak ON/OFF fluorescence ratio to ~1.6-1.7. A
medium-throughput fluorescence assay was developed and tested on 142 cultured soil microbial
strains.
Molecular dynamics (MD) simulations were performed to analyze the behaviour of TRI101 in its
apo form as well as with a DON ligand. Computational analysis of TRI101 was used to
determine the best residue fluorophore conjugation sites to produce a modified TRI101 that
could report the presence of DON in a solution. Amino acid residues G421 and A218 were
identified as the best candidates and a TRI101-G421C was designed and expressed
recombinantly in E. coli. When conjugated to TRI101-G421C, 7-diethylamino-3-(4′
maleimidylphenyl)-4-methylcoumarin (CPM) produced a detectable response to DON in
fluorescence assay with a decrease of 8-9% in emission intensity at the emission maximum
wavelength (480 nm).
Together, these results show that an E. coli rmf promoter-based biosensor can inexpensively
detect DON in liquid samples with relatively high detection sensitivity. A TRI101-based
biosensor demonstrated functionality in detecting DON however assay signal contrast and
production of recombinant TRI101 remain as limiting factors. Improvements to TRI101 yield,
testing A218C and other TRI101 mutants for improved performance, as well as further
enhancing the sensitivity and assay signal contrast for both biosensor designs should be the focus
of future research.Engineering Research Council of Canada (NSERC) Discovery Grants programFebruary 202
Acrylamide formation in wholewheat bread: quantitation using LC-MS approaches and understanding the effect of mitigation strategies
No full textSince the detection of acrylamide in foods, there has been growing interest in developing reliable, validated methods to quantify its concentration in staples such as bread, particularly in Canada. Processing factors like high temperature, low moisture, and long cooking times favor acrylamide formation, yet its quantitation is challenging due to the molecule’s small size, high polarity, and matrix effects that can exaggerate or underestimate concentrations. Thus, the development of validated methods and mitigation strategies are needed to accurately assess acrylamide formation during processing. In the first study, 40 diverse Canadian Western Red Spring Wheat cultivars were used to prepare wholewheat breads for acrylamide quantitation and bread quality analysis. The highest level observed was in the crust of Lillian (2021; 145.74 ng g−1), while the lowest was found in the crumb of Napayo (2020; 20.07 ng g−1). The second study tested fermentation time, baking regimen, steam injection, and L-asparaginase treatments (250, 500, 750 µg kg−1). Crust and crumb were analyzed for acrylamide, and the bread quality was evaluated by Volscan profiler, colorimeter, and an AACC scoring method. Baking loaves at a lower temperature for a longer time was the most ideal baking regimen for minimizing acrylamide formation in the bread samples. Additionally, 500 µg kg−1 enzyme was most effective at reducing acrylamide concentrations in bread samples. Furthermore, a short fermentation time (1.5 hr) significantly reduced (p< 0.0001) the acrylamide concentrations formed during baking. Conversely, a longer fermentation time and a shorter baking time at high temperature increased acrylamide the most across all treatments. Subsequent studies should focus on scaling findings to an industrial level to explore the feasibility of scaling up the various mitigation techniques. Overall, this research provides insights into strategies to mitigate acrylamide in bread production.February 202
The effects of nitrogen availability on plant species in the boreal tundra ecotone
Get PDFIn high latitude biomes, increasing temperatures due to climate change are predicted to increase nutrient availability. Given the boreal region is dominated by plant and fungal species that are adapted to surviving in low nutrient soil, an increase in nutrients like nitrogen may cause a variety of responses in mycorrhizae fungi and their host plants. I found that several plant species responded to three years of 10 – 100 kg ha-1 nitrogen addition by changing their leaf N isotope ratios, morphology and physiology. However, these changes showed no obvious correspondence with mycorrhizal status. Although ectomycorrhizal fungi slow down the mineralization rates of nitrogen, and help to immobilize nitrogen, both ectomycorrhizal host plants, Picea glauca (Moench) Voss, and Dryas integrifolia Vahl, increased in total chlorophyll ∂15N while lowering the C:N ratio within their tissue due to fertilizer. The ericoid host plants (Ledum decumbens (Aiton) Lodd. ex. Steud, Vaccinium uliginosum L., and Empetrum nigrum L.) all responded differently from one another and did not respond to nitrogen unlike the ectomycorrhizal host plants. These results suggest that mycorrhizal types do not predict how boreal plant species will take up and utilize inorganic nitrogen. In some regions, climate change has resulted in boreal forests range expanding northwards, especially with a northward shift of coniferous trees. Northward range expansion for conifers on the tundra may involve the establishment and expansion of tree islands: clusters of conifers that create microhabitats on their leeward side. While we predicted these microhabitats would benefit conifer establishment and survival, we did not find this. After planting P. glauca and Pinus banksiana Lamb, seed around tree islands near Churchill, Manitoba, I found higher germination further away from the tree islands and on the windward side.February 202
Muscarinic receptor antagonism activates TRPM3 channels to augment mitochondrial function and provide neuroprotection
Get PDFPeripheral neuropathy, commonly associated with diabetes, chemotherapy, and HIV- induced nerve damage, leads to progressive sensory deficits and nerve dysfunction. While muscarinic acetylcholine type 1 receptor (M1R) antagonism promotes sensory axon repair, the mechanisms underlying its neuroprotective effects remained unclear. Transient receptor potential melastatin-3 (TRPM3), a heat-sensitive cation channel, plays a crucial role in calcium signaling, mitochondrial function and neuronal metabolism, positioning it as a potential mediator of M1R antagonist-driven neuroprotection. This thesis investigated the mechanistic link between M1R antagonism and TRPM3 activation and explored the therapeutic potential of TRPM3 modulation in sensory axon regeneration.
M1R antagonists pirenzepine (PZ) and muscarinic toxin 7 (MT7) enhanced TRPM3-mediated Ca²⁺ influx in dorsal root ganglion (DRG) neurons, an effect that was abolished by TRPM3 inhibitors or extracellular Ca²⁺ removal. TRPM3 activation using CIM0216 and pregnenolone sulfate (PS) elevated intracellular Ca2+, promoted AMP-activated protein kinase (AMPK) phosphorylation via the Ca²⁺/calmodulin-dependent protein kinase kinase (CaMKKβ) pathway, leading to enhanced mitochondrial function, glycolysis, and tricarboxylic acid (TCA) cycle activity. Further analysis established that M1R antagonism stimulated TRPM3 by inhibiting phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, facilitating sustained calcium signaling and metabolic enhancement. TRPM3 knockdown via adeno-associated virus (AAV)-mediated shRNA suppressed the neurite-promoting effects of M1R antagonists, confirming its essential role in axonal plasticity.
To assess whether these findings translated to an in vivo setting, the streptozotocin (STZ)-induced diabetic neuropathy model was utilized, which recapitulated key sensory impairments such as mechanical allodynia, slowed motor nerve conduction velocity (MNCV), and thermal hypoalgesia. PZ treatment restored sensory function in diabetic mice, but co-administration of TRPM3 inhibitors (isosakuranetin and primidone) abolished these improvements, confirming that M1R-mediated neuroprotection was TRPM3-dependent. Despite the emergence of sensory impairments at 16 weeks post-STZ induction, corneal nerve loss was less pronounced than expected, suggesting a gradual progression of neuropathy, where functional impairments preceded structural degeneration. However, TRPM3 inhibition significantly reduced corneal nerve density, further highlighting its potential role in sensory fiber maintenance. This thesis established TRPM3 as a key modulator of sensory axon regeneration via Ca²⁺-dependent AMPK signaling, demonstrating its potential as a therapeutic target for peripheral neuropathy and neurodegenerative disorders.October 202
“Our needs, our priorities, listen to us!” recommendations for improving HIV prevention and the cascade of care from people living with HIV in Manitoba, Canada: a qualitative study
Get PDFAbstract Background The Canadian province of Manitoba has reported a 52% increase in HIV diagnoses during the past 5 years. Females are disproportionately affected by HIV and multiple intersecting health and social challenges, including houselessness, injection drug use, sexually transmitted and blood borne infections, and mental health conditions. Program and service development often ignore people’s complex lived experiences. Our aim was to describe recommendations made by people living with HIV (PLHIV) to inform a person-centred HIV cascade of care valuing the needs and ideas from PLHIV. Methods This qualitative study was conducted between October 2022 and May 2023. Thirty-two women, men, and gender-diverse participants completed a semi-structured interview. Interviews were recorded, transcribed, and analyzed using NVivo 12, deploying thematic analysis to understand major themes related to recommendations to care. This manuscript focuses on questions related to recommendations for the HIV cascade of care. Results Recommendations fell within two major themes: ‘Meeting people where they are at’ and an HIV educational strategy. The first theme included three main categories to make HIV services more accessible. (1) psychological (social programming, peer support during diagnosis, increased mental health services), (2) biomedical (HIV outreach, HIV services outside 9 –5 h, specialized care outside metropolitan areas, universal coverage for HIV medicines), and (3) social (transportation support, emergency housing, financial support) supports. The HIV educational strategy included five major categories: (1) physical posters and billboards in highly transited areas; (2) community meetings with peer-led education; (3) comprehensive sex education in schools; (4) training primary healthcare providers on stigma and discrimination; (5) and social media campaigns to reach younger audiences. We report on gender differences for recommendations where they arose. The themes described by PLHIV suggest a need to implement HIV care delivery models that will connect and maintain people in HIV care in Manitoba. Conclusions This study provides practical and person-centred strategies that could bridge the barriers PLHIV face when accessing and remaining in HIV care and expanding education and prevention about HIV in Manitoba
Evaluating factors that influence appetite and glycemic response to wild rice and wild rice blends in humans
Get PDFBackground: Wild rice (WR) has been reported to have better nutritional profile compared to white rice (WhR) and brown rice (BR). It has also shown numerous health benefits in animal models and in vitro studies. But no study has reported the effects of WR consumption on postprandial appetite and glycemic response (PPGR) in humans.
Objectives: To investigate the effects of cooked Canadian WR and wild rice blends consumption on palatability, postprandial appetite and PPGR in adults and evaluate the nutritional components that could be responsible for the study outcomes.
Design: The acute trial followed a randomized crossover controlled design. Participants (n=19, 10 males and 9 females) consumed 140 g of treatment; stovetop cooked WR, BR, WhR (control), a wild rice blend of 15% wild rice and 85% brown rice (WRB), and microwaved WRB with 250 mL water. Their blood glucose concentration and appetite were measured at intervals from 0 to 120 min. Palatability of the treatments was measured following consumption. To explore the potential impact of parboiling on blood glucose results, WR was parboiled and nutritional composition of the treatments used in the study and the parboiled WR were analyzed and compared.
Results: From the trial, it was observed that the stovetop cooked WR had about 32.7% increase in the PPGR when compared to parboiled WhR (p ≤ 0.05). No differences were observed for appetite among the treatments. Parboiled WhR (70.7%) and BR (72.4%) were more palatable than WR (61.3%) and WRB (57.1% for microwave and 64.0% for stovetop). Based on these results we explored the impact of parboiling on WR. We found that parboiling improved the protein, dietary fibre, amylose, total phenolic content, fat, and reduced the rapidly and slowly digestible starch, starch damage, total flavonoid content, and carbohydrates in WR. Also, the cooked parboiled WR showed intermediate estimated glycemic index (eGI) of 64 in in vitro digestion calculation compared to cooked non-parboiled WR with eGI of 77.
Conclusion: Short-term consumption of 140 g of cooked non- parboiled WR led to higher PPGR compared to parboiled BR and WhR in adults, despite WR having better nutritional profile than WhR and BR. Parboiling WR could be an excellent method to reduce blood glucose response to WR consumption, without meaningfully decreasing its positive nutritional properties. Further studies are needed to investigate insulin response following WR consumption and the effects of cooked parboiled WR on postprandial appetite and PPGR in humans.May 202
The Ideal and the Real: Epistemic and practice tensions in renovating long-term residential care settings for persons with advanced dementia
Get PDFAlthough existing research suggests the importance of physical environments on persons living with dementia in residential settings, less is known about whether and how this evidence, among other factors, shapes design processes in long-term residential care. Using process evaluation methods to explore the redesign of one residential dementia care setting in mid-Western Canada pre-pandemic, we identified and explored how the renovation of a residential dementia care setting reveals deeper epistemic and practice tensions. Qualitative data included five years of textual project documentation, and stakeholder interviews. Inductive thematic analysis was used to identify and explore three key tensions. First, complex, shifting and sometimes contradictory design goals reflected broader tensions between major goals of care. Second, multiple meanings of ‘best practice evidence’ and ‘innovation’ reflected tensions between scientific and practice knowledge, which were compounded by organizational communications strategies. Third, differing perceptions of the capabilities of persons living with advanced dementia reflected tensions between types of knowledge that may be particularly pronounced in the context of heavy workloads in these settings. We discuss the need for designers and facilities to more fully engage with evidence reviews and formative process evaluations, and to promote transparency among stakeholders about practical limitations and types of evidence.Mitac
Horizontal grain aeration testing and measurement system
Get PDFFarmers around Canada, specifically in Manitoba, predominantly utilize vertical grain aeration in their post-harvest grain storage systems to extend the storage life of the grain. Using horizontal aeration presents a more energy-efficient alternative to vertical aeration. However, manufacturers lack the information and theoretical calculations necessary to optimize the design of horizontal aeration systems. This means that despite its advantages, manufacturers remain hesitant to adopt horizontal systems due to insufficient data to inform their design.
This project aimed to address this issue on behalf of Dr. Fuji Jian and the grain storage research group at the University of Manitoba. The project focused on creating a bench-scale device for testing and measuring air resistance in horizontal grain aeration systems. The device measures the performance of horizontal airflow through an aeration system that results from different types of grain and system configurations. Project deliverables included the constructed and verified device, and preliminary testing and data collection for future Ph.D. research and eventual industry application.
The project's technical specifications were verified to ensure that the final prototype would meet the client's demands for a grain bin that could hold a load of grain and measure the performance of horizontal grain aeration. A structural design was carried out to ensure that the grain bin could hold a whole load of grain during operation. Other verifications included testing the radial airflow uniformity, whether vertical airflow is negligible, and adapting the grain bin to be used with various system configurations. The grain bin was found to satisfy all the criteria required by the client. The overall project successfully provided a method to measure horizontal grain aeration performance from the data collected.
There are several recommendations for how to improve this project further. The main recommendation is to minimize instrumentation in the grain bin. A combination of pitot tubes and mass flow sensors were used to measure airflow. This combination provides highly detailed measurements, but the consequence is several disruptions to the airflow. Replacing or reducing the instrumentation disruption to the airflow would be reduced, producing higher quality results. Additionally, some operation procedure improvements are recommended to help future researchers transition to working with pilot-scale prototypes