University of Saskatchewan Research Archive
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Effect of Feeding Ergot Alkaloids on Ruminal Metabolism, Growth Performance, Health and Welfare of Beef Cattle
Get PDFErgot contamination of cereal crops has been more prevalent within the last decade, increasing the occurrence in beef cattle diets. The overall objectives were to examine the effects of ergot alkaloids (EA) on ruminal metabolism, growth performance, health and welfare of beef cattle. The objective of the first study was to evaluate the effect of EA (20 mg/kg), a mycotoxin deactivating product (MDP; 1g/d) and their interaction (EA×MDP) on ruminal fermentation parameters using the rumen simulation technique (RUSITEC). This study was performed in a randomized complete block design, treatments were assigned (n = 4 vessels/treatment) within two RUSITEC apparatuses in a 2 × 2 factorial arrangement. Treatments included: 1) control (CON) diet; 2) CON diet + MDP; 3) CON diet + EA; and 4) CON diet + EA + MDP. Dry matter disappearance (P = 0.01; 87.9 vs. 87.2%), organic matter disappearance (P = 0.02; 88.8 vs. 88.4%), acetate proportion (P = 0.01), acetate:propionate (P = 0.03), microbial diversity (P = 0.05) decreased with EA. Inclusion of MDP increased OMD (P = 0.01; 88.3 vs. 88.9%) and NDFD (P 0.75 mg/kg EA caused reductions in performance and welfare concerns, although this breakpoint may be affected by environmental factors
Study of Radiation Tolerant Storage Cells for Digital Systems
Get PDFSingle event upsets (SEUs) are a significant reliability issue in semiconductor devices. Fully Depleted Silicon-on-Insulator (FDSOI) technologies have been shown to exhibit better SEU performance compared to bulk technologies. This is attributed to the thin Silicon (Si) layer on top of a Buried Oxide (BOX) layer, which allows each transistor to function as an insulated Si island, thus reducing the threat of charge-sharing. Moreover, the small volume of the Si in FDSOI devices results in a reduction of the amount of charge induced by an ion strike.
The effects of Total Ionizing Dose (TID) on integrated circuits (ICs) can lead to changes in gate propagation delays, leakage currents, and device functionality. When IC circuits are exposed to ionizing radiation, positive charges accumulate in the gate oxide and field oxide layers, which results in reduced gate control and increased leakage current. TID effects in bulk technologies are usually simpler due to the presence of only one gate oxide layer, but FDSOI technologies have a more complex response to TID effects because of the additional BOX layer.
In this research, we aim to address the challenges of developing cost-effective electronics for space applications by bridging the gap between expensive space-qualified components and high-performance commercial technologies. Key research questions involve exploring various radiation-hardening-by-design (RHBD) techniques and their trade-offs, as well as investigating the feasibility of radiation-hardened microcontrollers.
The effectiveness of RHBD techniques in mitigating soft errors is well-established. In our study, a test chip was designed using the 22-nm FDSOI process, incorporating multiple RHBD Flip-Flop (FF) chains alongside a conventional FF chain. Three distinct types of ring oscillators (ROs) and a 256 kbit SRAM was also fabricated in the test chip. To evaluate the SEU and TID performance of these designs, we conducted multiple irradiation experiments with alpha particles, heavy ions, and gamma-rays. Alpha particle irradiation tests were carried out at the University of Saskatchewan using an Americium-241 alpha source. Heavy ion experiments were performed at the Texas A&M University Cyclotron Institute, utilizing Ne, Ar, Cu, and Ag in a 15 MeV/amu cocktail. Lastly, TID experiments were conducted using a Gammacell 220 Co-60 chamber at the University of Saskatchewan. By evaluating the performance of these designs under various irradiation conditions, we strive to advance the development of cost-effective, high-performance electronics suitable for space applications, ultimately demonstrating the significance of this project.
When exposed to heavy ions, radiation-hardened FFs demonstrated varying levels of improvement in SEU performance, albeit with added power and timing penalties compared to conventional designs. Stacked-transistor DFF designs showed significant enhancement, while charge-cancelling and interleaving techniques further reduced upsets. Guard-gate (GG) based FF designs provided additional SEU protection, with the DFR-FF and GG-DICE FF designs showing zero upsets under all test conditions. Schmitt-trigger-based DFF designs exhibited improved SEU performance, making them attractive choices for hardening applications. The 22-nm FDSOI process proved more resilient to TID effects than the 28-nm process; however, TID effects remained prominent, with increased leakage current and SRAM block degradation at high doses. These findings offer valuable insights for designers aiming to meet performance and SER specifications for circuits in radiation environments, emphasizing the need for additional attention during the design phase for complex radiation-hardened circuits
Development of novel solid acid catalysts for biodiesel production from green seed canola oil through alcoholysis process
No full textThe abstract of this item is unavailable due to an embargo
No Words Necessary
Get PDFIn my Master of Fine Arts exhibition titled No Words Necessary, I explore ideas of self-reflection, and cultural connections through abstraction, portraiture, and augmented reality. My practice involves abstract paintings that depict spiritual beings as orbs similar to Woodland Style of Indigenous art where orbs are connected by energy and vibration. How might this look through a spiritual lens? Teachings and knowledge from my ancestral background as a Nehiyaw inform my current practice as an Indigenous artist. Art and cultural teachings create opportunities for healing and self-reflection. Looking back at archival photos of Indigenous people creates a sense of strength and resilience that is reflected in my exploration of portrait paintings and drawings. Augmented reality creates an environment about the spirit world that can be seen and unseen in relation to Indigenous culture
Manufacturing an Exact Solution for 2D Thermochemical Mantle Convection Models
No full text© 2023. The Authors. Geochemistry, Geophysics, Geosystems published by Wiley Periodicals LLC on behalf of American Geophysical Union.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Natural Sciences and Engineering Research Council of Canada. Grant Numbers: RGPN-2020-04467, RGPN-2020-06332Peer ReviewedIn this study, we manufacture an exact solution for a set of 2D thermochemical mantle convection problems. The derivation begins with the specification of a stream function corresponding to a non-stationary velocity field. The method of characteristics is then applied to determine an expression for composition consistent with the velocity field. The stream function formulation of the Stokes equation is then applied to solve for temperature. The derivation concludes with the application of the advection-diffusion equation for temperature to solve for the internal heating rate consistent with the velocity, composition, and temperature solutions. Due to the large number of terms, the internal heating rate is computed using Maple™, and code is also made available in Fortran and Python. Using the method of characteristics allows the compositional transport equation to be solved without the addition of diffusion or source terms. As a result, compositional interfaces remain sharp throughout time and space in the exact solution. The exact solution presented allows for precision testing of thermochemical convection codes for correctness and accuracy
Bone Microstructure and Bone Strength at the Distal Radius In Relation to the Pubertal Growth Spurt in Adolescence
Get PDFIncreased incidence of forearm fractures during the adolescent growth spurt is well documented but it is unclear if bone structure is weaker during this rapid period of growth. The objectives of this research are to 1) determine the precision errors (CV%RMS) for bone strength outcomes under specific loading conditions, and 2) compare bone strength and microstructural (microarchitectural, geometry, density) outcomes of the distal radius across the pubertal growth spurt.
We categorized 143 typically developing children into 3 groups, based on their estimated somatic maturity (years from the age at peak height velocity, APHV): Pre -0.5y prior to APHV; Peri +0.5y within APHV, and Post >0.5y post to APHV. We analyzed distal radius HR-pQCT images to obtain trabecular and cortical bone microstructure and finite element (FE) derived strength outcomes. Two types of models were created – a homogenous model which applies a single elastic modulus to the entire bone tissue, and a scaled (E-BMD) model which determines the elastic modulus based on the imaged bone mineral density. We compared the outcomes across the groups using multiple analysis of covariance (MANCOVA), with age, height, and body mass as covariates (Wilks’ Lambda, p<0.05), followed by pairwise comparisons.
Precision error of the bone strength outcomes were 3.2% - 8.3% for homogenous and 8.6% - 11.9% for scaled model. Peri group had 20% lower bone stiffness than Pre (p=0.01), and 39% higher factor-of-risk than Post (p=0.01) groups. Peri had 12-19% lower trabecular thickness, bone volume, trabecular bone density and total bone density than Pre group. Peri group also had 5-19% lower cortical thickness, cortical bone mineral density and tissue mineral density, cortical total and bone volume, and cortical area than Post group (p<0.05).
Our findings indicate that the FE models can precisely quantify the bone strength outcomes. Additionally, it indicates lower bone strength and maturity-specific deficits in trabecular and cortical bone micro-architecture and density at the distal radius around the age at peak height velocity. Prospective monitoring of bone strength development over the pubertal growth spurt is warranted. These findings support the hypothesis of transient weakness in bone development during the peak growth spurt in adolescence
DANCE FOR WELLNESS: INDIGENOUS ADOLESCENTS’ PERSPECTIVES ON MENTAL HEALTH, WELLNESS, AND DANCE.
No full textBackground: The effects of colonization, the Indian Residential School System, and intergenerational trauma damages Indigenous ways of living and profoundly impacts the mental health and wellness of Indigenous adolescents. This impact was felt by the adolescents in a northern Saskatchewan Indigenous community; therefore, the community initiated a wellness-based dance program.
Purpose and Research Questions: The purpose of this qualitative case study was to generate insight into the understanding and experiences of mental health and wellness in Indigenous adolescents aged 10 to 19 and identify if and how a 4-week dance program affects their sense of mental health and wellness. The research was guided by the following questions: 1) What are Indigenous adolescent’s understandings and experiences of mental health and overall sense of wellness; 2) what are the positive and negative influences on the adolescent’s sense of mental health and wellness; and 3) what are Indigenous adolescents’ understandings and experiences of mental health and wellness after participating in a four-week dance-based program?
Methods: Eight participants completed semi-structured interviews and symbol-based data collection methods were selected to honour Indigenous ways of knowledge transfer. Thematic and symbol-based methods were used for data analysis.
Findings: The findings demonstrate that dance improved the Indigenous adolescents’ mental health and wellness. Dance also helped the participants to temporarily escape from their life challenges and negative experiences, and had a positive effect on the participants’ moods before, during, and after class. In addition, dance provided the unique ability to allow the participants to feel comfortable in expressing themselves and their emotions through movement. Three unique themes and multiple subthemes emerged including: It Helped My Mental Health and Everything (Dance Helps Me Escape, Dance Makes Me Feel Good, and Dance Is Just Really Fun); A Little Bubble Around Me When I Dance (I Can Be More Confident and I Can Be Myself); and We Won’t Judge You Here (Creation of Friendship, He Said I Was Really Good, and Improved School Attendance).
Implications: There are a number of implications for future dance programming, nursing practice, research, and education, such as for school administrators to understand what attracts Indigenous adolescents to attending school, for Registered Nurses (RN) to create dance-based programs for improving mental health and wellness, and the incorporation of trauma-informed research in core undergraduate and graduate courses.
Conclusions: Additional research is needed to advance our knowledge on the effects of dance among Indigenous adolescent mental health and wellness. Overall, this study provides insight into the perspectives of Indigenous adolescents’ living in remote northern Saskatchewan on mental health and wellness and their experience with participating in a four-week dance program
Study of Hybrid Cellulose Nanocrystals in Polymeric Nanocomposites
Get PDFModern society's demand for biobased and sustainable materials is increasing annually. Environmental pollution related to petroleum-based plastics has motivated research into developing alternative bioplastics. These alternatives include carbohydrates such as starch, cellulose, pullulan, kefiran, and proteins. However, films from these biobased resources are brittle, moisture sensitive, and difficult to process for bioplastic applications. To address these challenges, various modification methods have been studied, including chemical modification and reinforcement by nanoparticles. Regarding nanoparticles, the exponential increase in metallic nanoparticle usage for various applications has raised concerns about their harmful effects on the environment. Thus, cellulose nanocrystals (CNCs) are being investigated as an alternative natural filler material. Cellulose is the most abundant biopolymer on Earth extracted from a wide range of resources, including wood, bacteria, and tunicate which is a marine animal.
In the past decades, academic and industrial communities have considered CNCs to develop biodegradable materials for a wide range of applications. The alignment and interaction between CNCs with different aspect ratios in a polymeric nanocomposite are less clear when used as a filler. In this thesis, the effects of magnetic field and shear force on the alignment of CNCs have been investigated. Two approaches to film development have been studied including multilayer and crosslinking to produce CNC-based films with functional properties. In these studies, the effect of hybrid i.e., a mixture of high aspect ratio CNCs (tunicate-based CNCs) with low aspect ratio CNCs (wood-based CNCs) on the improvement in the mechanical and physicochemical properties of CNC-based nanocomposites has been established. This overcomes the limitation of wood-based CNC for developing films with tunable properties. A deeper insight has been developed into the interaction between CNCs of different aspect ratios by understanding the change in morphology, surface properties, mechanical properties, and thermal properties. These works enhance the understanding of CNC and its application in developing functional materials.
In summary, the magnetic field alignment and shear force alignment of the CNCs improved the physicochemical and mechanical properties of the samples, with hybrid CNC shear force aligned films showing elastic moduli up to 2 GPa in the parallel force direction. The 2D-XRD results on the CNCs films showed, at lower low concentrations (≈1%), the calculated Hermans order parameters for TCNC with high ARs (≈63) were much higher than for WCNC with low ARs (≈12). In comparison with TCNC's Hermans order parameter, hybrid CNC films (HCNC) (1:1 ratio of
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WCNC:TCNC) displayed approximately similar order parameters. The chiral nematic CNC films successfully interlocked in a multilayer system while maintaining their structure with different visible color reflections. Through self-assembly, WCNC films displayed a chiral nematic structure. In order to develop biodegradable and functional materials, different reflection colors (red, green, and blue) were achieved and fabricated. When TCNC was added to WCNC (hybrid 1:1 ratio), the colors faded. This implies that the change in the average aspect ratio can interfere with the formation of the chiral nematic structure. CNCs in a hybrid configuration have been crosslinked with PVA polymer. The results showed a decrease in hydrophilicity and an increase in mechanical performance up to 1.76 GPa for the elastic modulus. The elongation at break also decreased by almost 70% with CNC reinforcement. XPS results confirmed the formation of covalent bonds for all nanocomposites except those reinforced with WCNC, which exhibited lower levels of crosslinker (MBA) and C–C formation. The percolation network in the hybrid configuration showed that the thermal properties and the chiral nematic structure of the CNC films can be altered with the aspect ratio of the CNCs. Films containing the higher aspect ratio CNCs showed a surface area as high as 91.9 m2/g which was significantly high. Cross-sectional SEM images demonstrated that WCNC films exhibit chiral nematic phases, which are also confirmed by their iridescent appearance. TCNC films exhibited almost twice the elongation at break when compared with WCNC films.
In this research, a comprehensive understanding of the intermolecular interaction between hybrid CNCs and their effects on the mechanical, thermal, moisture barrier, gas barrier, physicochemical, and optical properties was investigated. Overall, the study will support the development of innovative biobased materials
Understanding the Relationship between People with Physical Disabilities and Their Companion animals
Get PDFDisability among humans is an important concern in both developed and developing countries. Although efforts have been made to protect the rights of people with disabilities, and public attitudes towards people with disabilities (PWDs) have become increasingly supportive over the past decade, people with disabilities still experience a wide range of social exclusion. Social exclusion not only limits the social participation of people with disabilities but also impacts their well-being. Improving the inclusion and well-being of people with disabilities requires multiple strategies. At the social level, it calls for legislation and policies based on the social model of disability. At the individual level, social support helps people cope with pressures and challenges leading to enhanced well-being. The human-animal bond is understood as a mutually beneficial relationship, with companion animals providing emotional and social support in unique ways.
This research adopts human needs theory, social exclusion theory, social support theory, and attachment theory to explore the lived experiences of people with physical disabilities and their experiences of living with a companion animal in China. The research questions of this study are four-fold: (1) What are the experiences of being disabled in urban China?; (2) What are the experiences of participants living with companion animals with whom they have a bond?; (3) What are the perceived benefits and drawbacks of living with companion animals?; and (4) What is the relationship between participants with physical disabilities and their companion animals?
Drawing on a phenomenological approach, in-depth interviews with six participants with physical disabilities showed that participants experienced multiple forms of social exclusion, including limited opportunities for education and employment, inadequately accessible facilities, and negative public attitudes toward people with disabilities, which led to smaller social networks and a strong sense of loneliness. The unfulfilled social needs influence participants’ well-being negatively. Social support from others helped participants cope with disability-related stressors. In addition to such human support, the support offered by companion animals was significant, providing physical, emotional, and social benefits that positively influenced the lives of people with physical disabilities. Although participants identified challenges caused by the financial, practical, and emotional burdens and by the loss of a pet, the benefits of living with a companion animal outweighed the drawbacks. Participants viewed companion animals as a family member and developed a deep bond with their companion animals, which was understood as love, care, support, and trust.
This dissertation is explanatory in nature and contributes to the sociological study of the human-animal bond. As the first study investigating experiences of PWDs living with companion animals in China, this dissertation contributes to a better understanding of the nature of the human-animal relationship. Expanding upon previous research findings, I argue that companion animals play a supportive role in the lives of PWDs and compensate for a lack of human support. Therefore, living with companion animals may be a meaningful way to improve the lives of people with smaller social networks or limited human support. Valorizing the important role of companion animals also helps promote animal welfare and recognize animals as valuable social members
Elucidating the mechanisms of extracellular glycogen utilization in Gardnerella spp.
Get PDFGardnerella spp. are associated with bacterial vaginosis, in which normally dominant lactobacilli are replaced with facultative and anaerobic bacteria including phenotypically diverse Gardnerella spp. that likely differ in their role in pathogenesis. Co-occurrence of multiple Gardnerella species in the vaginal environment is common, and different species are dominant in different women. Given the potentially different roles of Gardnerella species in the vaginal microbiome, understanding the factors contributing to their population structure is important. Competition for nutrients could play an important role in determining the microbial community structure.
Glycogen is one major nutrient available in the vagina. It is accumulated inside vaginal epithelial cells and is released into the lumen when epithelial cells are lysed. Glycogen digestion is accomplished by the coordinated action of enzymes collectively described as amylases that belong to family 13 within the glycosyl hydrolase class (GH13) of carbohydrate active enzymes. In the vagina, host secretions contain amylase enzymes; however, the contributions of Gardnerella spp. to this process and interactions of different Gardnerella spp. with glycogen are not well understood.
The first objective of this thesis was to annotate GH13 enzymes in Gardnerella spp. and to characterize the activity of an a-glucosidase enzyme conserved among Gardnerella spp. This conserved putative amylase was annotated as an a-amylase (EC 3.2.1.1), suggesting that it was an endo-acting enzyme that releases malto-oligosaccharides from glycogen, but comparison to other functionally annotated enzymes suggested that the conserved amylase sequence was an a-glucosidase (EC 3.2.1.20). Biochemical characterization of the conserved enzyme from G. leopoldii NR017 demonstrated that it had a-glucosidase activity. This intracellular enzyme was predicted to be involved in digestion of imported malto-oligosaccharides.
The second objective of this thesis was to assess the extracellular glycogen digestion ability of different Gardnerella spp., identify the extracellular glycogen hydrolyzing enzymes and characterize their activities. Culture supernatants of a total of 15 representative isolates from different Gardnerella species showed amylase activity suggesting that glycogen digestion is a conserved property in the genus Gardnerella. Glucose, maltose, maltotriose and maltotetraose were identified as glycogen breakdown products and no species-specific fingerprints of glycogen breakdown products were observed. Analysis of the predicted proteomes of the study isolates led to the identification of two predicted extracellular glycosyl hydrolases (a-amylase and a-amylase-pullulanase) (belonging to family 13 (GH13)) in all but one isolate. The amylase domains of the a-amylase-pullulanase and a-amylase enzymes released maltose, maltotriose and maltotetraose from glycogen while the pullulanase domain released maltotriose from pullulan. These results showed that a-amylase and a-amylase-pullulanase enzymes can hydrolyze glycosidic bonds in glycogen and contribute to the nutrient pool available to the vaginal microbiota.
Once glucose, maltose, maltotriose and maltotetraose are produced from glycogen digestion, how are these products transported inside the bacteria? Do all Gardnerella species utilize these substrates for growth? The third objective of this thesis was to identify the transporters associated with uptake of glycogen breakdown products and to determine if all Gardnerella spp. can utilize those sugars for growth. Five different maltose, malto-oligosaccharide and maltodextrin specific ABC transporters were identified bioinformatically in Gardnerella spp. Although some transporters are conserved across all Gardnerella species, species-specific transporters are present in G. vaginalis and G. leopoldii suggesting that these species may have access to a greater diversity of sugars or a competitive advantage in uptake. All Gardnerella isolates grew in the presence of glucose, maltose, maltotriose and maltotetraose, demonstrating their ability to utilize glycogen breakdown products. In addition, most isolates showed more growth on maltotriose and maltotetraose compared to glucose and maltose suggesting their preference for the longer chain malto-oligosaccharides.
The overall findings of the research work described in this thesis contribute to our understanding of how different Gardnerella species interact with glycogen. Understanding factors contributing to the population dynamics of more or less pathogenic Gardnerella spp. within the vaginal microbiome and identifying phenotypic characteristics that distinguish different species is important for improving diagnostics for women’s health and identifying high risk microbiomes. This in turn will help to prevent ineffective and unnecessary treatments, which can lead to increased antibiotic resistance, treatment failure, and recurrent infection