University of Saskatchewan Research Archive
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Affirming Self, Affirming Community: Outreach in the Spirit and Memory of Neil Richards
Get PDFPresented at the 2023 Association of Canadian Archivists Conference as a part of 11B. Outreach for Representation and Belonging in Charlottetown, PEI.The Neil Richards Collection of Sexual and Gender Diversity was established in 2010 and contains more than 8,000 unique items. Neil Richards spent his life and career at the University of Saskatchewan preserving LGBT history in Saskatchewan. Sadly, Neil Richards passed away in 2018, and without his enthusiastic and engaging personality, the collection became underutilized, and its growth slowed. This project involved the creation of marketing videos featuring real users and their experiences with the collection to increase the awareness and the use of the archive by the community. Inspired by Apple (2021), our goal was to give this collection back to the community by removing the high academia stigma and exclusivity associated with archives in hopes of inspiring partnerships and to create a more accurate and holistic reflection of LGBTQQIP2SAA history in Saskatchewan. Since the creation and release of the videos, interactions with the collection have markedly increased, including donations, integration into University of Saskatchewan courses, its use in events like Drag Story Time for Adults and partnerships with community organizations like OUTSaskatoon, the University of Saskatchewan Students’ Union Pride Centre, Saskatoon Pride, the Western Development Museum and JusticeTrans. This session covers our process for the creation and distribution of the videos, the initiatives that have formed from the renewed interest in the collection and where we hope to take the collection in the future
Residual Diagnostics and Statistical Inference for Shared Frailty Models
Get PDFFrailty models are commonly used for analyzing clustered survival data and accounting for unobserved heterogeneity. Shared frailty models are random-effect models in which the frailties are shared among individuals within groups. Several R packages, such as survival, frailtyEM, fraltypack, frailtysurv, and frailtyHL, are available for fitting shared frailty models. However, little research has been conducted to compare their performances, leaving users without clear guidance in selecting an appropriate tool for analyzing clustered survival data. The first study in this thesis aims to address this gap by providing an overview of current R packages for fitting shared frailty models and comparing their performances through simulation studies. After fitting a shared frailty model, model diagnostics are an essential part of the modelling process. The use of residuals in assessing model adequacy is a conventional tool for normal regression. In the second study of this thesis, we propose to use the Z-residual for detecting the non-linearity in the shared frailty model. Through a simulation study, we investigate the power of Z residuals in detecting non-linear effects in covariates and demonstrate their effectiveness in diagnosing models using real data on the survival of acute myeloid leukemia patients. Typically, all residuals in survival analysis are calculated using the full dataset, resulting in a bias problem due to double usage of the dataset. In the third study of this thesis, we propose applying cross-validation methods to compute residuals for diagnosing a semi-parametric shared frailty model and investigate the performance of cross-validatory Z-residual for diagnosing a shared frailty model with non-parametric baseline hazards. We compare Z-residuals calculated through three methods: without cross-validation (No-CV) method which is the basic algorithm, 10-fold cross-validation (10-fold) and leave-one-out cross-validation (LOOCV). Through simulation studies, we investigate their performances in the detection of nonlinear effects in covariates and identification of the outliers in the dataset through graphical visualization and overall GOF test. We also compared No-CV Z-residual and LOOCV Z-residual in a real data application for identifying outliers for a kidney infection dataset. Finally, in the fourth study of this thesis, we extended the Z residual to diagnose the proportional hazards assumption and compare it with existing residual methods
Coal-Based Activated Carbon via Microwave-Assisted ZnCl2 Activation for Methyl Violet 2B Dye Removal: Optimization, Desirability Function, and Adsorption Mechanism
Get PDF© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).The Researchers Supporting Project No. (RSP2023R1), King Saud University, Riyadh, Saudi ArabiaPeer ReviewedIn this work, activated carbon (referred to as MCAC) was produced by microwave radiation assisted ZnCl2 activation using Malaysian coal (MC) as a precursor. The Brunauer–Emmett–Teller findings indicate that the MCAC has a relatively large surface area (798.18 m2/g) and a mesoporous structure (average pore diameter of 3.67 nm). The removal of Methylene Violet (MV 2B) a cationic dye model, was employed to investigate the adsorption properties of MCAC. A numerical desirability function in the Box–Behnken design (BBD) was employed to optimize the independent crucial adsorption variables as follows: A: MCAC dose (0.02–0.1 g); B: pH (4–10); and C: time (5–25 min). The results of equilibrium and dynamic adsorption showed that the adsorption of MV 2B followed Freundlich and pseudo-second order models, respectively. The maximum amount of MV 2B dye that the MCAC could adsorb (qmax) was 134.1 mg/g. Electrostatic interactions, π-π stacking, H-bonding, and pore diffusion contribute to the adsorption of MV 2B dye onto the MCAC surface. This study demonstrates the potential to utilize MC as a low-cost precursor for the efficient synthesis of MAC and its utility for the removal of pollutants
Assessing the Neural Circuits and Behavioral Manifestations of Working Memory in Rats
No full textUnderstanding the brain requires us to answer both what the brain does, and how it does it (Niv, 2021). Working memory (WM) is an essential cognitive ability that maintains, and actively manipulates, a finite amount of information to support goal directed behavior. My thesis project consists of a series of experiments that aim to increase our understanding of what brain circuits underly WM, and how behavior can be measured to infer WM in rats. The Nucleus Accumbens (NAc) core is a striatal brain region that integrates cognitive and limbic information to direct attention and behavioral action sequences towards reward-predicting stimuli. Previous work from the Howland group describes both cortical and subcortical brain regions that underly performance on the Odor Span Task (OST), a measure of olfactory working memory capacity (WMC) in rodents; however, the role of the NAc core in mediating performance of the OST is currently unknown. To investigate this role, I assessed how chemical inactivation of the NAc core, and infusion of dopamine (DA) receptor-specific antagonists, impact odor span and foraging behavior. We found that chemical inactivation of the NAc core caused a profound reduction in odor span, indicating impaired WMC. We also observed a profound reduction in odor span when D2, but not D1, receptors were selectively antagonized. Chemical inactivation and DA receptor-specific antagonism had little effect on behavioural measures used to infer locomotion. Together, these results point to a substantial role of D2 receptors of the NAc core in mediating performance of the OST. Recent advances in automated behavioral analysis enable researchers to obtain a detailed and objective record of a diversity of behaviors across species. As automated analysis of a behaviorally complex task such as the OST poses significant technical challenges, I collaboratively worked to quantify behaviors used to infer WM within a spontaneous novelty recognition task. We found that supervised machine learning (SML)-generated behavioural predictions were accurate on much of our dataset, but required some human intervention to correct for sub-optimal predictions. SML-based analysis enabled quantification of rat-stimulus interaction duration, total distance travelled, interaction bout count, and novel stimulus approach latency. This analysis was used to assess the effects of Cannabis smoke exposure on novelty preference to infer WM, where we found that Cannabis smoke exposure impacts novelty preference in a load-dependent, and stimuli- specific manner. To our knowledge, this study is the first demonstration of SML-based behavioral analysis in the context of a spontaneous interaction-based test
Extension and refinement of a stochastic modelling approach to assess ice-jam flood hazard
No full textThis is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).Peer ReviewedIn the spring of 2020, the town of Fort McMurray, which lies on the banks of the Athabasca River, experienced an ice-jam flood event that was the most severe in approximately 60 years. In order to capture the severity of the event, a stochastic modelling approach, previously developed by the author for ice-jam flood forecasting, has been refined for ice-jam flood hazard and risk assessments and ice-jam mitigation feasibility studies, which is the subject of this paper. Scenarios of artificial breakage demonstrate the applicability of the revised modelling framework
Direct Numerical Simulation of Transition to Turbulence and Cerebral Blood Flow
No full textThe abstract of this item is unavailable due to an embargo
ADSORPTION OF PHARMACEUTICALS FROM CONTAMINATED WATER BY ADSORBENTS DEVELOPED FROM REED CANARY GRASS
No full textThe abstract of this item is unavailable due to an embargo
GUIDING ATTENTION IN A MULTI-DISPLAY ARTISTIC INSTALLATION
No full textA multi-channel video installation (MVI) enables designers and artists to display supplementary information in their work and create an engaging and immersive experience. However, viewers may lose track or not know where to start without proper attention guidance, leading to a disconnection between displays and a loss of deeper messages. To address this challenge, we used visual attention cues (icons) and audio attention cues (audio cues) to direct viewers’ attention to the second display when important events occurred. We found that icons were especially effective in guiding attention, but they did not enhance the experience much. Audio cues were less effective in guiding attention, but they significantly improved the experience. We explain these findings and offer insights for future development. We suggest using both icons and audio cues to provide strong attention guidance and a positive user experience. Based on the results from our study, we designed Inter-Play, an immersive and visually captivating MVI that invites participants to explore the intricate interplay between water, energy, and food (WEF) systems. Four individual scenes spanning three screens present two-player interactive games that bring virtual worlds to life. The games present unique challenges and opportunities for players and audience members to actively participate or simply be an observer. While players strive to achieve high scores and outwit their opponents, the audience becomes engrossed in the unfolding narrative witnessing the influence that human action and inaction have on the environment. Through interactive gameplay, carefully designed visuals, and a thought-provoking narrative, Inter-Play aims to inspire a collective commitment to environmental stewardship and foster a deeper understanding of the complex dynamics within WEF systems
Evaluation of Rhizobium spp. as effective biocontrol agents for Aphanomyces root rot in field pea (Pisum sativum L.)
Get PDFAphanomyces root rot (ARR), caused by the soil-dwelling oomycete Aphanomyces euteiches, poses a significant threat to global pulse crop production, causing severe root damage and yield reductions in field pea and other legume crops. Given the limited effectiveness of traditional disease management methods, this study explored the biocontrol potential of Rhizobium spp., dinitrogen (N2) fixing bacteria known for their symbiotic relationship with legume roots and use as N fertilizer replacements.
Obtained in this study from the nodules of Pisum sativum L. trap plants, a total of 70 bacterial isolates were screened for antagonistic activity towards A. euteiches in dual plate bioassays. An additional 24 isolates from existing culture collections and field collected legume nodules were also subjected to these assays. Most isolates, which were identified as rhizobia, were non-antagonistic. In comparison, three non-rhizobial nodule endophytes (NREs) isolated from the nodules of P. sativum trap plants— Burkholderia strain SU2B2, Kosakonia cowanii LL3B1, and Pseudomonas chlororaphis subsp. aurantiaca LL3B2 — exhibited antagonistic activity towards A. euteiches in vitro. Notably, K. cowanii LL3B1 was capable of completely halting A. euteiches colony growth for over 30 days.
In three sets of completely randomized sterile growth pouch assays, NREs K. cowanii LL3B1 and P. chlororaphis subsp. aurantiaca LL3B2, when applied as liquid seed inoculants, demonstrated the potential to enhance P. sativum nodulation by Rhizobium strains and reduce disease severity without affecting initial leaf development. Additionally, they increased N2-fixation in P. sativum compared with uninoculated controls.
This study also revealed the diversity of Rhizobium associated with P. sativum nodules, by isolating and identifying seven distinct species within the Rhizobiaceae family from P. sativum nodules. While none showed independent antagonism towards A. euteiches, the presence of certain Rhizobiaceae species alongside K. cowanii LL3B1 and P. chlororaphis subsp. aurantiaca LL3B2 showed potential to synergistically enhance antagonistic activity towards A. euteiches in vitro when evaluated in dual plate bioassays. Additional research is recommended to assess their impact on plant health and potential synergistic effects when applied as seed inoculants along with rhizobia.
These findings indicate that NREs, particularly K. cowanii and P. chlororaphis subsp. aurantiaca, hold potential as biocontrol agents against ARR. Consequently, further investigation of the biocontrol capabilities of bacteria associated with legume nodules may improve the efficacy of current disease mitigation strategies
Applications of and Barriers to Prescribed Fire for Grassland Management in Saskatchewan
Get PDFFire can be a powerful tool for the management and conservation of remaining grasslands in the northern Great Plains. Extensive modification of northern prairies driven by persistent management ideologies have significantly altered the historic pattern of disturbances. Elevated risks associated with wildfire, further declines in grassland biodiversity, and growing threats to ecosystem goods and services are prevalent. The intersection of climate change mitigation, biodiversity conservation, and adaptive governance requires a multifaceted, socioecological approach to confront current and impending challenges in the region. The intentional use of fire, as an Indigenous cultural practice and natural ecosystem process, has been shown to be an effective land management tool to meet numerous objectives but continues to be underutilized in southern Saskatchewan and elsewhere. The purpose of this research was to explore the risk management and ecological applications of prescribed fire with a focus on barriers to the effective use of fire. Specifically, I 1) use remote sensing of grassland vegetation at different scales to preemptively identify hazards associated with prairie fire and describe how prescribed burning could mitigate those hazards, 2) examine ungulate grazing selectively in response to prescribed burning and impacts to heterogeneity of prairie habitat for grassland management and conservation; and 3) conduct a comparative analysis of strategies for reintroducing prescribed fire in Saskatchewan’s prairie ecozone, and to identify barriers to interagency collaboration and expansion of the practice as a culturally significant endeavour and important economic, ecological, and community-building process.
Imagery from satellites and unmanned aerial vehicles (UAVs), combined within a simple, integrated model identified fire hazard metrics suitable for operational use in topographically variable, northern mixed prairie. Grazing intensity altered vegetation distribution and fuelbed heterogeneity. Normalized difference vegetation index (NDVI) and slope were predictors of burn patterns, offering those tasked with fire mitigation and suppression useful information for safe and effective planning, implementation, and analysis. Reintroduction of fire into a semi-arid, grazed grassland had heterogeneous effects on vegetation and temporarily altered spatiotemporal patterns of herbivory by bison and cattle. Multiscale observations from remote sensing platforms evaluated changes pre- and post-burning and demonstrated bison and cattle selectivity at a very fine spatial scale. Limited impacts to plant community composition, with year-to-year variation a dominant factor, suggested prudently managed northern mixed prairie was resilient to the fire-grazing interaction. Finally, comparative analysis of agency strategies for restoring fire in southern Saskatchewan acknowledged the importance of developing a community of practice within a multiscalar, collaborative effort. Current programs were limited by a range of social, informational, practical, and regulatory constraints. Established programs with significant investment in trained personnel and equipment accomplished the largest and most complex areas burned. Those with limited funding using a collaborative approach in a centralized location burned most frequently. A newly formed, coordinating agency provided structure and additional funding to support various organizations, beginning to close a gap between research and implementation to advance the practice in Canadian prairies. Greater integration with federal and provincial fire management organizations is required to emulate similar U.S. models. Increased understanding, coordination, and implementation of prescribed fire will build adaptive capacity and community resilience to confront rising threats locally and globally