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Evaluation of species selection and management decisions for fall seeded cover crops in Manitoba
No full textThere is limited local research available on cover crops in the eastern Canadian Prairies, including Manitoba. Cover crops are an agronomic practice in which plants are used to cover the soil for ecosystem benefits, rather than for market. Cover crops are often seeded and managed outside the conventional growing season, as to not displace cash crops. Ecosystem benefits (e.g. soil erosion control, N retention, weed suppression) can only be realized when there is sufficient cover crop establishment and growth. Cover crop performance depends on the overlapping influences of species selection and management decisions made in the context of a particular location. The limitations of GDD accumulation and precipitation amounts and timing in Manitoba present unique challenges when making cover crop decisions. The objective of this thesis was to compare cover crop decisions and to evaluate how these decisions affected the performance of different fall seeded cover crops in Manitoba. In addition, the impact of fall seeded cover crops on following cash crops was determined. This was achieved through three research studies. The first research study compared seven cover crop species, plus one mixture, seeded at three different dates in the fall. Two site-years were dry and two site-years were wet. Emergence, biomass production, C:N ratio, and ground cover were similar between winter killed cool season cover crop species when seeded around September 1. The second research study evaluated the effects of fall seeded cover crops on a spring wheat (Triticum aestivum L.) test crop. Three cool season annuals, one winter annual, and one cover crop mixture were seeded in the fall. Winter killed cover crops had no effect on the test crop. Fall rye (Secale cereale L.) and the mixture that contained fall rye had a negative effect on wheat density and wheat yield. The third research study compared fall rye cover crop termination timings prior to soybean (Glycine max (L.) Merr.) and edible bean (Phaseolus vulgaris L.). Managing the living cover crop in the spring with strip tillage removed the soybean yield penalty caused by late fall rye termination but only slightly improved edible bean yield. These results highlight the opportunity for using winter killed fall seeded cover crops in Manitoba with minimal risk to a following small grain crop. Fall rye used as a cover crop prior to spring wheat and edible bean requires termination prior to planting. Soybean can be planted green into fall rye with strip tillage. Results from this research show that there are opportunities for fall seeded cover crops in Manitoba cropping systems and will provide guidance for cover crop decision making. Future research under these environmental conditions should explore cover crop performance and thresholds for ecosystem benefits in Manitoba.February 202
Prevalence, causes and consequences of interspecific pollen transfer in the subalpine plant communities of Polemonium brandegeei
No full textMany pollinators visit multiple plant species, causing pollinators to carry and deposit diverse pollen loads. Although interspecific pollen transfer is ubiquitous, few studies have tested how pollen load composition and donor identity affect plant fitness. First, pollen from close relatives may decrease reproductive success due to their ability to germinate, clog pistils and usurp ovules, whereas pollen from distantly related donors may have negligible effects. Second, when pollen receipt is low, flowering neighbours may enhance pollinator visitation and cause a positive relationship between conspecific and heterospecific pollen deposition. I investigated the fitness consequences of pollen donor-recipient relatedness and pollinator sharing in two populations of a subalpine herb with diverse pollinators, Polemonium brandegeei, and its co-flowering communities.
First, I collected open pollinated stigmas from all abundant co-flowering species in the communities. To test the prediction that pollinator sharing would be common in my study communities I used pollen transfer networks and floral visitor networks. Pollinator sharing was common between co-flowering species at CO-DM and WY-VD in 2022. All sampled species received or donated heterospecific pollen; most species, however, received little heterospecific pollen in each pollen load. Partial exclusion experiments revealed that both large pollinators (hummingbirds and hawkmoths) and small pollinators (bees and flies) contributed to outcrossed conspecific pollen and heterospecific pollen deposition. Second, I explored the fitness consequences of pollinator sharing and interspecific pollen transfer. Type II regressions between heterospecific pollen and conspecific pollen number and germination revealed that only neutral and facilitative relationships occurred between co-flowering species. To test the prediction that congeneric donors decrease P. brandegeei pollen germination and seed set, I conducted experimental hand pollinations including mixes of conspecific pollen and heterospecific pollen from a closely and distantly related species. General linear mixed models indicated that distantly related donors had no effect on P. brandegeei reproduction, although closely related donors decreased pollen germination and seed set. This study suggests that pollinator sharing between native co-flowering species can be common and beneficial in plant communities; competition, however, may occur if closely related species begin to co-flower due to range changes or phenological shifts.University of Manitoba Graduate Fellowship, Manitoba Association of Plant Biologists Fellowship, GETS (Graduate Enhancement of Tri-Council Stipends) and Anne Worley’s NSERC Discovery grantOctober 202
Estimating soil hydraulic parameters in fine-textured soils using HYDRUS-1D coupled with PEST
No full textFrequent flooding and drought events lead to moisture stress in crops, which leads to poor crop yield and quality. Thus, water management strategies are needed to create a conducive environment for plant growth and performance. An effective strategy requires a long-term understanding of soil moisture dynamics regulated by local soil hydraulic properties and hydrologic factors. This study focused on estimating these soil hydraulic parameters using HYDRUS-1D coupled with PEST (external calibration software) and exploring the non-unique nature of the solution for four growing seasons (2016 –2019). One hundred initial guesses of parameter sets were generated for each year for model calibration. The volumetric soil water contents determined at the site within the 0 - 10 cm, 10 - 30 cm, 30 - 70 cm, and 70 - 130 cm layers over the growing seasons were used to calibrate and validate the models. The statistical parameters used for the evaluation of models were NashSutcliff efficiency (NSE) (0 - 1), Percent bias (PBIAS) (±10%), Ratio of Root Mean Square Error to standard deviation (RSR) ( 0.5). The results showed that PEST was useful in establishing the non-linearity and non-unique nature of the solution, which established that different parameter sets could result in similar performance and, therefore, ascertained the use of a more rigorous approach (maximum likelihood) based on different parameter sets to improve the reliability of the results. The model performance was satisfactory for the simulation of soil water content in 2016, 2017, and 2019 using the calibrated parameter sets. Poor model performance was observed for the 2018 validation period, which showed how the physical manipulation of soil (tillage), physiological stage of the crop, and soil response to weather (shrink-swell) could alter the soil hydraulic properties to a great extent within a season. The results also demonstrated that the saturated hydraulic conductivity varied over the years to about ten times for the topsoil (plough horizon) but was almost constant for deeper soil layers.Got funding from SCAP and NSERCOctober 202
Doxorubicin-induced cardiomyopathy: role of endoplasmic reticulum stress
No full textCancer and cardiovascular disease are the two leading causes of mortality in Canada. Unfortunately, these two diseases are intricately linked, as the anti-cancer drug, doxorubicin (Dox) can cause detrimental effects on the heart. Amongst the various potential mechanisms of Dox-induced cardiomyopathy (DIC), little is known about the role of endoplasmic reticulum (ER) stress which may lead to cardiomyocyte apoptosis and heart failure. We used rat cardiomyocytes as well as an in vivo murine model to characterize Dox-induced ER stress and subsequent changes in cardiac structure and function. To date, there are no approved pharmacological therapies for the prevention and/or treatment of DIC. We investigated the therapeutic potential of two compounds: 1) An anti-inflammatory cytokine, Interleukin-10 (IL-10); and 2) an anti-diabetic medication, Empagliflozin (EMPA), in the setting of DIC.
In isolated cardiomyocyte studies, Dox (10 µM) induced ER stress and apoptosis. We identified cleaved activating transcription factor 6α (ATF6α) as the major ER transmembrane protein which is upregulated following Dox treatment. Dox-induced ER stress changes were mitigated by the pretreatment of both IL-10 (10 ng/ml) and EMPA (500 nM). IL-10 primarily worked through downregulating ATF6 cleavage and promoted cell survival by downregulating caspase-12 activation and phosphorylation of c-Jun N-terminal kinase. On the other hand, EMPA mitigated ER stress via activation of inositol-requiring kinase 1α (IRE1α) and downregulation cleavage of ATF6α. The effects of EMPA in decreasing oxidative stress, inflammation, and apoptosis were also noted.
In the rat model of DIC (cumulative dose, 15 mg/kg), there was downregulation of ER chaperones followed by an increase in apoptosis. Prophylactic and concurrent treatment of EMPA (10 mg/kg body weight, daily) mitigated ER stress via upregulation of ER chaperones and downregulation of ER stress induced apoptosis. There were significant detrimental changes in the structure and function of the myocardium by the end of the experiment in the Dox group which were rescued by EMPA treatment.
These preclinical studies suggest that ER stress plays an intermediary role in worsening DIC which can be modulated by IL-10 and/or EMPA. The molecular details in this study provide a rationale for the prophylactic use of EMPA to reduce DIC.Heart and Stroke Foundation
CANUSA Grant
Molson Women’s Heart Health ProgramMay 202
Extrusion texturization of air-classified barley protein: a sustainable plant-based meat alternative
No full textIntroduction: Barley’s share as human food has remained limited to ~3% of its production, with most of it utilized for animal feed. High protein barley cultivars have potential to become an attractive novel plant-based food ingredient in growing protein ingredient space. Plant-based alternatives, aimed to substitute meat consumption emerge as relatively sustainable alternatives catering to the ever-increasing meat consumption pattern. The present study addresses the sustainability needs by partially replacing highly refined protein ingredients with relatively sustainable dry fractionated protein-rich fraction from barley.
Methods: Firstly, a pilot-scale air classification process was employed to fractionate barley flour from two varieties i.e., CDC Valdres and CDC Austenson. Significant protein enrichment, with 2.13-fold increase (27.1% db) for CDC Austenson and a 1.75-fold increase (26.3% db) for CDC Valdres compared to their original feed flour protein contents was obtained. Secondly, these protein enriched barley fractions were used for meat analogues development by blending them with pea protein isolate at 15% and 30% w/w barley inclusion. The blends were subjected to a high-moisture extrusion, at three different moisture contents (47.5%, 52.5% and 57.5% w/w). Next, the physical properties such as density, color, texture (cutting strength, hardness, chewiness, gumminess and springiness), and techno-functionality (water and oil holding capacity) of the meat analogues were analyzed.
Results: Protein-rich barley fraction inclusion up to 30% produced sufficiently texturized product for each variety, with barley containing meat analogues indicating better visual textural characteristics than those made from pea protein alone. Meat analogues produced at 30% protein-rich barley fraction substitution had significantly higher values for hardness, chewiness, and gumminess (p<0.05) compared to pea protein alone. However, increase in feed moisture content resulted in lower values for these textural attributes. Therefore, through variation in feed moisture content and formulations, meat analogues with a wide range of textures were obtained.
Conclusion: This study provided a basis for barley’s fractionation and inclusion of its protein enriched fractions into plant-based meat analogues. Future work can be focused on comprehensive sensory evaluations and assessment of consumer acceptability of barley-based meat alternatives.October 202
Isotopic and petrologic constraints on intracontinental deformation and metamorphism, Churchill Province, Nunavut
No full textThe Canadian Churchill Province was the locus of repeated, regional reworking in the Paleoproterozoic associated with five major orogenic events that ultimately resulted in the formation of Earth’s first supercontinent, Nuna. Tectonic models for the Archean and Paleoproterozoic evolution of the Churchill Province have been formulated at the broadest scale, and consequently, the timing, nature and regional extent of deformation and metamorphism associated with these collisional events are poorly constrained. In this thesis, the metamorphic and deformation histories of two relatively unexplored regions in Nunavut were characterized in order to contribute to the understanding of the processes that reworked the boundaries and interior of the Churchill Province during development of Nuna.
Aeromagnetic data and geological mapping on Boothia Peninsula, Nunavut, revealed the presence of a ~165 km long, 5-10 km wide high-strain zone, named the Sanagak Lake shear zone (SLsz), that marks the transition from dominantly N-trending Thelon-related structures in the north to SW-trending Trans-Hudson-related structures in the south. Field, microstructural, petrologic and isotopic data indicated that the SLsz is a south-dipping, strike-slip (sinistral) shear zone that formed in the mid-crust (~ 0.52 GPa) at 1804 ± 6 Ma. The timing, geometry and kinematics of high-strain deformation is consistent with north-directed compression associated with far-field stresses derived from the Trans-Hudson orogeny, and marks the northern limit of Trans-Hudson related deformation.
Geologic mapping, phase equilibria modelling, and multi-mineral geochronology coupled with previously collected petrological and isotopic data from the Baker Lake area outline four lithotectonic domains named the Woodburn Lake and Ketyet River groups, Quoich River domain, Kramanituar Complex and the Thirty Mile domain. Each of these domains experienced distinct pressure – temperature – time – deformation (P-T-t-d) histories and are separated by shear zones that facilitated differential burial-exhumation in the Paleoproterozoic. All domains were buried and reworked, to varying degrees, between ca. 1.93 and 1.90 Ga during the Snowbird Orogeny. The Kramanituar Complex was exhumed rapidly following ca. 1.9 Ga metamorphism, whereas the Quoich River and Thirty Mile domains exhumed between ca. 1.87 and 1.85 Ga during the accretionary phases of the Trans-Hudson Orogeny.Geological Survey of Canada's "Geo-Mapping for Energy and Minerals" programOctober 202
Hypertension and diabetes control: faith-based centres offer a promise for expanding screening services and linkage to care in Ghana
No full textAbstract Background Hypertension and type 2 diabetes mellitus (T2DM) are important contributors to noncommunicable disease related morbidity and mortality. Health systems could benefit from exploring the use of Faith-Based Centres (FBC) to screen and link suspected cases for further care in order to help achieve Sustainable Development Goal (SDG) 3. The study investigated the role of faith-based screening for T2DM and hypertension and the linkage of cases to the healthcare system and examined the care cascade in the Kassena Nankana Districts of Northern Ghana. Methods We screened individuals from 6 FBCs for elevated blood pressure and hyperglycaemia. Suspected hypertension and T2DM cases were referred to health facilities for confirmation and subsequently followed them up for 3 months. We assessed the prevalence of behavioural and metabolic risk factors, including hypertension and T2DM, and the retention of referred cases in the healthcare system over follow up period. We further assessed levels of awareness, treatment and adequate control of hypertension and T2DM. Results A total of 631 participants were screened, (mean age 49 ± 16years, 73% female) from 6 Faith based Centres. More males than females reported smoking tobacco (14.5% vs. 0.7%) and been physically active (64.5% vs. 52.7%) while more females were obese (29.6 kg/m2 vs. 14.5 kg/m2) and had a higher mean waist circumference (89.0 cm IQR 75-116 cm vs. 84.2 cm IQR 72–107 cm), hip circumference (101.5 ± 10.6 cm vs. 96.4 ± 8.6 cm) and waist-to-hip ratio (0.86 ± 0.1 cm vs. 0.87 ± 0.1 cm) than males. The prevalence of confirmed hypertension and T2DM was 27.9% and 3.5% respectively with no observed sex differences. We observed deficits in the hypertension and T2DM care cascade with reported low awareness, treatment and uncontrolled levels. A 3-month follow up showed a retention in care of 100% in month one and 94.9% in the third month. There was an increase in treatment (39.4% in month-1 and 82.8% in month-3) and control (26.3% in month-1 and 76.3% in month-3) of hypertension and T2DM combined. Conclusion Faith-based centres have the potential to enhance the screening, linkage to the healthcare system, and management of hypertension and T2DM. This improvement over the routine system could lead to earlier diagnoses, a reduction in complications, and decreased premature mortality from cardiovascular diseases. Consequently, these efforts would contribute significantly to achieving SDG 3
Medical Assistance in Dying (MAiD) while incarcerated vs Compassionate Release: a comprehensive analysis of “Dying with Dignity” within the Canadian correctional system
No full textThe principle of equivalence of care asserts that incarcerated individuals have access to the same level of healthcare as the general population. Carceral institutions have been notably criticized for having substantially fewer resources available and overall poor access to healthcare services. Medical Assistance in Dying (MAiD) is a medical process that assists eligible individuals who are seeking to end their lives. To be eligible, one must be eligible for health services funded by provincial, territorial, or federal healthcare services, be 18 years old and mentally competent for making health decisions for one’s self and have a grievous and irremediable medical condition such as a disease, illness and disability and be in an advance state of decline that cannot be reversed which has resulted in unbearable pain, and mental suffering.
The right to choose how and when to end one's life falls under the purview of the right to private life. Article 3 of the Universal Declaration of Human Rights (UDHR) states that everyone has the right to life, liberty, and security of a person. Article 12(1) of the International Covenant of Economic, Social and Cultural Rights (ICESCR) states that the state parties to the Covenant recognize everyone's right to enjoy the highest attainable standard of physical and mental health. Article 12(2), which ensures that state parties enable citizens to exercise this right while holding each binding state accountable to have the adequate means to exercise this right to its fullest potential, and specifically Article 12(2)(d), which recognizes the need for states to create conditions for sustaining medical services and medical attention in the event of sickness for all individuals, regardless of status in society.
MAiD within Canadian carceral settings, however, presents difficulties because an inmate, by definition, is an individual who is denied their fundamental human rights. Using the foundation of these fundamental human rights, this report will argue for the use of Compassionate Release for terminally/dying inmates to allow these individuals to exercise their right to die with dignity and obtain the highest standard of healthcare during their last days.May 202
Impact of fava bean flour particle size on the quality of blended flour and bread made from it
No full textFava beans are recognized for their nutritional richness and sustainability, presenting a promising ingredient for various food products. This study explores the potential of fava bean flour in bread production, focusing on how particle size and substitution levels influence product characteristics.
Fava beans were milled into three particle sizes (0.14 mm, 0.50 mm, and 1.0 mm) using a single-stage Ferkar multipurpose knife mill. Physicochemical analyses revealed significant differences (p ˂ 0.05) among flour samples, with the 0.14 mm size exhibiting higher starch damage, protein, and fat contents. Functionality assessments showed varied properties across particle sizes, indicating diverse applications in food formulations. Moreover, in vitro digestibility assays showed improved starch digestion (p ˂ 0.05) with increasing flour particle size, emphasizing the importance of particle size in tailoring fava bean flour for specific culinary and nutritional needs.
Further study examined the rheological properties, baking characteristics, and microstructure of bread produced using X-ray µ-CT with different levels of fava bean flour substitution (10%, 20%, and 30%) and the three particle sizes in wheat flour blends. Evaluation of baking characteristics revealed that fava bean flour substitution levels had a more pronounced impact on bread quality characteristics than particle size variation. For the three particle sizes, the bread produced with a 10% substitution level exhibited baking characteristics closest to those made with wheat flour alone. Additionally, hyperspectral imaging (HSI) demonstrated high classification accuracy (> 99%) in classifying fava bean-fortified bread into high and low-protein samples and based on colour characteristics, suggesting its reliability for quality monitoring in commercial bakeries.
In conclusion, the study provides insights into optimizing fava bean-fortified bread formulations, guiding decisions on particle size, substitution levels, and final product quality. With the growing demand for alternative protein sources, integrating fava beans into wheat flour offers opportunities for innovation and sustainability in the food industry.October 202
Prevalence of mental health disorders among pregnant women living in public housing in Manitoba.
Get PDFBackground: Women are more likely to experience a higher burden of mental health disorders than men. Pregnancy is one of the most sensitive and complex periods in a woman’s life; the physical and psychological changes that take place during pregnancy can impact pregnant women’s mental health. In Canada, approximately one in four women experience a mental health disorder during pregnancy or the postpartum period. Maternal mental health disorders include a range of disorders and symptoms, including but not limited to depression, anxiety, and psychosis. Housing is considered one of the most critical social determinants of physical and mental health, particularly among pregnant women. Public housing (PH) is a government-funded housing program that provides affordable housing to individuals or families with limited or fixed incomes. Finlayson et al., (2013), found a higher proportion of women in PH than men. Women with mental health disorders during pregnancy and living in poor quality housing conditions are less likely to receive adequate prenatal care. They are also more likely to engage in unhealthy behaviours such as smoking and use of alcohol and other substances which are known to cause devastating consequences for mothers, babies, and society. While there is evidence to suggest that people living in PH have a higher burden of mental health disorders, little is known about these disorders among pregnant women living in PH. This is despite the unique physiological and social changes that they experience as they transition to parenthood.
Objectives: The study examined the prevalence and incidence of mental health disorders (mood and anxiety, substance use, psychotic and personality disorders and any mental health disorders) among pregnant women who had a live singleton birth while living in PH and compared with pregnant women who did not live in PH during the study period.
Methods: A population-based retrospective cohort study was conducted among 2,226 pregnant women who lived in PH and 57,132 pregnant women who did not live in PH, aged 18 to 45 years who experienced at least one pregnancy that resulted in a singleton, live birth between April 1, 2009–March 31, 2018 in Manitoba. Descriptive statistics were used to describe maternal demographic characteristics (age, income quintiles, receipt of income assistance, high school completion, parity, Charlson Commodity Index, region of residence). Univariate and multiple logistic regressions were used to calculate the diagnostic prevalence of mental health disorders before conception among pregnant women in both groups. Negative binomial regression was used to compare the incidence rates of these disorders among the same two groups of women during pregnancy and postpartum period.
Results: When compared with the women who did not live in PH, women who lived in PH had significantly higher odds of being diagnosed with all mental health disorders five years before conception: (a) mood and anxiety disorder (OR, 2.08; 95% CI, 1.91, 2.26), (b) substance use disorder (OR, 3.03; 95% CI, 2.65-3.47), (c) personality disorder (OR, 2.85; 95% CI, 2.17-3.73), (d) psychotic disorder (OR 3.26; 95% CI, 2.25-4.72), and (e) any mental health disorders (OR 2.21; 95% CI, 2.03-2.41). However, I found no significant differences in the odds for mood & anxiety disorders, substance use disorders, and any mental health disorders when comparing women who lived in PH with their comparison after adjusting for the covariates. Personality and psychotic disorders could not be compared between the two groups in the multivariable analysis due to the small number of events.
Furthermore, the unadjusted incident rates of mental health disorders diagnosed during pregnancy and after birth were significantly higher among women who lived in PH compared with their comparison for mood and anxiety disorders (RR, 1.23; 95% CI, 1.06-1.42), substance use disorders (RR, 1.54; 95% CI, 1.16-2.03), personality disorders (RR 2.71; 95% CI, 1.56-4.72), and any mental health disorders (RR 1.12; 95% CI, 0.99-1.27). There was no statistically significant difference for psychotic disorders (RR 1.30; 95% CI, 0.48-3.61). After adjusting for the covariates, the incident rate of substance use disorders was significantly lower among the women who lived in PH compared with women who did not live in PH. There were no significant differences in the incident rates for mood & anxiety disorders and any mental health disorders between the two groups.
Conclusion: Unadjusted models showed that women living in PH had higher diagnostic prevalence and incidence of mental health disorders when compared with those who did not live in PH. However, in the fully adjusted models, receipt of income assistance (IA) accounted for much of the observed differences in mental health disorders between those who lived and those who did not live in PH. This study highlights the critical importance of addressing income inequities among residents of public housing with limited financial resources to improve their overall health and social outcomes.Faculty of Graduate Studies Research Completion Scholarship (Award Number: 47255)
Women’s Health Research Foundation of Canada (Award Number: 45556)
The Manitoba Family 1994 Legacy Scholarship (Award Number: 44056)
Evelyn Shapiro Award for Health Services Research (Award Number: 45144)February 202