University of Lethbridge Theses
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- ItemOvule defects in Arabidopsis thaliana PIN localization pathway mutants lead to reduced seed set(Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, 2025) Reiter, Jaxon W.; University of Lethbridge. Faculty of Arts and Science; Schultz, ElizabethChapter 1: Auxin is a plant hormone that is essential for a wide range of growth and developmental processes in plants. The coordinated, polar transport of auxin through plant tissues is crucial for proper development and function. The asymmetric localization of PIN-FORMED (PIN) proteins determines the directionality of auxin transport between cells and across a tissue, creating an auxin gradient that can influence gene expression and development. It is well known that auxin gradient establishment is vital for vegetative development, including leaf and root formation, but the involvement of auxin in reproductive development is less-well studied. The plasma-membrane localization of PIN proteins to direct auxin transport between cells is a critical process that involves a complex vesicle transport pathway and is regulated by a diverse set of genes. This review provides an overview of the current state of knowledge regarding the roles of PIN proteins during the development of the reproductive structures of a flower, the gynoecium and androecium, and describes some of the genes that have been proposed to function in this PIN localization pathway. Mainly, the importance of PIN1 localization and PIN1-mediated auxin transport for the development of the gynoecium, including the carpel tissue, ovary, ovules, and female gametophyte, is described in detail, emphasizing the importance of these processes during reproductive development in plants. Chapter 2: The formation of the gynoecium, including the stigma, style, transmitting tract, ovary, ovules, and female gametophytes requires the correct establishment of auxin gradients across a tissue directed by polar transport. PIN-FORMED (PIN) proteins are crucial for establishing local cellular auxin gradients that establish spatially organized auxin maxima and minima. PIN1 vesicle transport is tightly regulated by various genes that play a role in vesicle formation, transport, uncoating, and membrane localization. SCARFACE/VASCULAR NETWORK DEFECTIVE 3 (SFC/VAN3), FORKED1 (FKD1) & FORKED-LIKE (FL) Group 1 genes, COTYLEDON VASCULAR PATTERN 2 (CVP2) and CVP2-LIKE 1 (CVL1), PINOID (PID), and ROTUNDA3 (RON3) have all been proposed to be key players in the regulation of PIN1 vesicle trafficking. Mutations to these genes have been shown to disrupt PIN1 localization and lead to developmental defects such as impaired root development and vein formation. However, the role of these genes has not been previously characterized in gynoecium development, despite mutants showing severe reductions to seed set. This study examines the underlying causes of the seed set reductions present in fkd1/fl1-2/fl2/fl3, sfc-40, and cvp2/cvl1 mutants by analyzing reproductive development. Through manual pollination experiments, observation of pollen tube growth, and the analysis of ovule defects and pPIN1:PIN1-GFP expression during ovule development, I identified that reduced seed set in these mutants results from a gynoecium defect. Specifically, a reduced seed set involves altered ovule development, and I suggest that the observed morphological defects are consistent with alterations to PIN1 localization during early ovule development stages (2 ii-iii) in these mutants. This study suggests, for the first time, that SFC, FKD1, FL1, FL2, FL3, CVP2, and CVL1 play an important role in reproduction during ovule development.
- ItemExplicit zero density for the Riemann zeta function(Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2024) Farzanfard, Golnoush; University of Lethbridge. Faculty of Arts and Science; Fiori, Andrew[See thesis for abstract]
- ItemAn assessment of provincial policy and youth vaping rates in Alberta(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Hepp, Amanda; University of Lethbridge. Facutly of Health Sciences; Hallström, LarsTo date, no research has examined the impact of the new youth vaping policy in Alberta which was implemented July 2021. The purpose of this study was to examine changes in youth vaping and purchasing patterns in Alberta following the new legislation. Cross-sectional data collected before and after the policy's implementation were compared. Additionally, differences between sex, gender, and grade level were evaluated. Cross-sectional data were obtained through two cycles of the Canadian Student Tobacco Alcohol and Drugs Survey from students in grades 7 through 12 in 2018/19 and 2021/22 (pooled n = 15,578). The samples were weighted to represent youth in Alberta in each period. Changes in vaping prevalence and underage purchases between survey waves were analyzed using proportions and logistic regression models adjusted for confounders. In Alberta, there was a 5.1% reduction in the prevalence of youth vaping following 2021 legislation to restrict this activity. The weighed proportion of students who vaped decreased from 19.9% in 2018/19 to 14.8% in 2021/22. After adjustment for confounders, there was a statistically significant reduction on past 30-day vape use between survey waves (OR: 0.65, 99% CI: 0.56–0.76). This decrease was more pronounced in males and students in grades 10–12. In 2018/19, 12.6% of youth purchased vape products underage and this slightly increased to 13.3% in 2021/22, however, these changes, including stratification by sex/gender, were not statistically significant. There was a statistically significant decline in youth vaping between survey waves, particularly among older youth and males, during the introduction of a new prevention policy. However, unmeasured factors such as societal trends and cultural norms may have also played a role.
- ItemMuslim immigrant women's experiences of mental health challenges in Southern Alberta, Canada(Lethbridge, Alta. : University of Lethbridge, Faculty of Health Sciences, 2025) Hosseinpour, Zohreh; Faculty of Health Sciences; Kellett, PeterThe purpose of this study was to explore the experiences of mental health challenges in Muslim immigrant women in Southern Alberta. Exploratory descriptive qualitative research design and semi-structured interviews with ten Muslim women were employed. Thematic analysis of these collected data showed that Muslim immigrant women participants experienced some mental health challenges due the intersection of pre-migration and post-migration factors. To cope with mental health challenges, Muslim women utilized a series of coping mechanisms including seeking professional help. However, some elements such as cultural and religious factors impacted their decisions. The study recommended that stakeholders, policy makers, and mental health professionals provide Muslim immigrant women with culturally safe services to promote their mental well-being.
- ItemExamining permafrost detection and validation techniques in thermally complex mountainous terrain: a case study in the Ogilvie Mountains, Yukon, Canada(Lethbridge, Alta. : University of Lethbridge, Dept. of Geography and Environment, 2025) Nicholson, Ria E.; University of Lethbridge. Faculty of Arts and Science; Bonnaventure, PhilipClimatic warming necessitates a more comprehensive understanding of permafrost distribution. However, permafrost cannot be directly observed due to its subsurface nature, leading to a reliance on predictive models. Models commonly lack comprehensive validation through independent field observation and are thus prone to uncertainty. The goal of this research is to explore the limitations of permafrost model validation in a heterogeneous periglacial environment. Permafrost evaluation through two independent models in the Ogilvie Mountains were sampled using 74 cryotic assessment sites. The sampling goal was to identify permafrost in-situ, examining the concept of "testability". Sampling was performed using the ground thermal profiling method. Interference from impenetrable substrates caused 51.4 % of tests to fail. This data informed a probability of testability model. Overall, the landscape exhibited polarized testability, with elevation as a predictor. This highlights a critical knowledge gap in permafrost research today regarding uncertainty and validation.