Graduate Theses and Dissertations

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https://hdl.handle.net/10388/381

This collections holds all University of Saskatchewan graduate level electronic theses and dissertations (ETDs) published since 2005. More than 700 print theses published before 2005 have been digitized and added to the collection as well.

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Social Media Influencers and Artificial Intelligence: Opportunities and Challenges
(2024-07-24) Do, Thi Hai Ha; Murphy, William H.; Zhang, David; Teucher, Ulrich
This study examines social media influencers’ (SMIs) perceptions of the role of artificial intelligence (AI) in advancing their relationships with followers, their views of the opportunities/dangers of AI in assuring their authenticity, and their perspectives towards virtual SMIs in terms of affecting the future of SMIs. Adopting a qualitative phenomenological approach, the study explores how SMIs’ (a) perceive AI as a tool to help SMI activities, (b) perceive AI as a positive/negative effect on relationships with followers, (c) perceive virtual SMIs (non-human) as having an effect on the future of SMIs. Data was collected through 17 semi-structured interviews with Canadian SMIs in various fields. This study shows that AI is perceived to offer significant opportunities for SMIs including improved data analytics, enhanced connectedness, and strengthening SMIs’ relationships with their followers. However, SMIs are concerned about dangers of AI, including loss of expressing ones’ true self and loss of honesty with their followers. Collectively, participants indicated concerns about their authenticity when AI is used. Furthermore, virtual SMIs are perceived as a threat to SMIs, making it difficult for SMIs to compete on brand deals but also to possibly replace SMIs in the future. Additionally, this study reveals practical implications for SMIs by providing insights into opportunities and challenges being faced in the context of AI.
A Comprehensive Study on Quality Aspects and Industry Perspective in Backporting
(2024-07-24) TASNIM, JARIN; Roy, Dr. Chanchal K.; Schneider, Dr. Kevin A.; Roy, Dr. Chanchal K.; Schneider, Dr. Kevin A.; Roy, Dr. Banani; Rochan, Dr. Mrigank
Code quality assurance has emerged as a well-established pillar to ensure effective software development and maintenance. Large and intricate software systems (e.g., Linux, Adobe Reader, Collabora, etc.) often require developers to version source code and manage multiple stable releases simultaneously. In general, prior stable releases are maintained by Backporting, which refers to applying changes taken from a newer release to an old release. In such cases, software quality assurance can be challenging for old stable releases for a variety of reasons. First, older releases often differ from newer (upstream) releases in terms of code dependency, infrastructure, architecture, and maintenance strategy. Second, backport maintenance is often not reviewed consistently to prioritize upstream development. Lastly, as software releases evolve with con- tinuous maintenance, developers often fail to maintain code in accordance with essential quality standards. As a result, poor-quality code and design choices can emerge in stable releases, affecting their reliability and stability. Although researchers have extensively scrutinized the quality assurance practice and paradigm in upstream versions, how code evolves and quality issues arise in the backporting procedure is yet to be ex- plored. Thus, to fill this gap in existing research work, we analyzed how software quality deviates in terms of size, complexity, and coupling throughout backporting. We found that as software releases evolve, backports are responsible for 11.5% and 12.3% of quality degradation and improvement, respectively. Furthermore, backporting can significantly affect the complexity and size of old releases. In our second study, we strive to observe when and why technical debt (fine-grained quality issues) arises as stable releases evolve through backporting. Our exploration reveals that the early-phase of Apache releases and the mid-phase of Eclipse and Python releases are more prone to technical debts in the release life cycle. Moreover, we found develop- ers’ high workload and low exposure can lead to new technical debts in stable releases. Lastly, in our third study, we explored expert opinions to get a non-biased, reliable view of developers’ needs and challenges to ensure code quality in the backporting process. We asked 38 experts and analyzed their challenges to ensure code quality for the backporting process. This study reveals the several subjective factors behind the failed quality assessment in backporting practice, including code comprehension, lack of efficient decision-making standards, lack of testing guidelines, scarcity of organization and tool support, etc.
FUNCTION-VALUED TRAITS FOR CHARACTERIZING AND COMPARING THE SPATIAL CONFIGURATION OF PLANT ROOT SYSTEMS
(2024-07-24) Pei, Yujie; Schneider, David J; Schneider, David J; Ireson, Andrew; Hallin, Emil; Rayan, Steven
Plants are essential and powerful ecosystem engineers. Compared with the above-ground parts of plants, root systems have been studied less frequently as accessing them is arduous and time-consuming. Root traits act as drivers of plant and ecosystem functioning, and root phenotyping is a fundamental procedure in a plant breeding program that helps to identify crop varieties with better root traits. The improved crop plants are tolerant to abiotic stresses, e.g., heat, drought, and nutrient deficiency, playing a vital role in sustainably combating climate change and feeding a rapidly growing global population. The widely used numeric-valued trait (NVT) approach computes and collects numerical values, such as maximum depth, maximum width, and tip count, from 2D and 3D root system models from various types of images. However, capturing the full complexity of the spatial distribution of the plant’s entire root system by NVTs is always challenging. Additionally, root systems are highly variable in spatial configurations, even among replicates of the same genotype grown in controlled laboratory settings, causing difficulties in making statistical inferences among biological replicates by the NVT approach. This thesis describes an alternative based on function-valued traits (FVT) to address the abovementioned problems. In particular, the FVTs are related to probability distributions estimated from the image background (i.e., the area not occupied by roots) rather than the foreground (i.e., the pixels corresponding to the plant root tissue per se). Each of these three FVTs is associated with a marked point process and encodes information about the spatial configuration of roots at all length scales. In turn, these probability distributions can be analyzed and compared by using methods of functional data analysis (FDA) to assess systematic differences between plant root systems due to developmental, genetic, and environmental effects. The practical utility of the FVT approach is demonstrated using collections of images of phosphorus-efficient and phosphorus-inefficient genotypes of sorghum grown in pouches in the presence of sufficient and growth-limiting concentration of phosphorus at 7, 10 and 14 days after transplantation. This is a challenging dataset because the images from distinct sets of biological replicates are easily distinguished “by eye,” but these visually apparent are only poorly reflected in the conventional statistical tests using NVTs. In contrast, the FDA-based statistical tests show that the three FVTs described here can readily distinguish among replicates with visually distinct spatial configurations. FVT pipelines have promising applications in characterizing other 2D and 3D branching structures, including but not limited to leaf veins, above-ground portions of plants such as trees, river systems, and blood vessels.
Integrating Cognitive Rehabilitation and Technology for Individuals with Memory Concerns
(2024-07-24) Grewal, Karl Singh; O'Connell, Megan; Cammer, Allison; McWilliams, Lachlan; Spiteri, Raymond; Ruggiano, Nicole; Williamson, Linzi; Kosteniuk, Julie
This dissertation contributes to a growing body of research required to make cognitive rehabilitation for individuals with dementia more accessible to people living with dementia and their families. Our population is aging, and with age comes both normal and abnormal cognitive aging. As a result, increasing numbers of people will require support to manage age-related changes in areas such as cognition and functional ability. One avenue to accessibly increase support is through off-the-shelf technology. Through two studies, this dissertation developed a more detailed understanding of how technology could support individuals and families by surveying attitudes, beliefs, and existing technology use of care partners (Study 1); and by attempting to merge technology with cognitive rehabilitation through a series of case studies (Study 2). Study 1 reported that care partners were relatively comfortable with technology, using it for functional tasks and some caregiving. Experiences with technology ranged being positive, neutral, or negative. Barriers to technology use were identified, including cost, lack of knowledge, security/privacy concerns, and undesirable features. Facilitators included access to support, and presence of desirable features. Some care partners were merging technology with caregiving and seeing benefit. Others were concerned that technology would not be feasibly adopted for caregiving. COVID-19 also seemed to increased technology usage and may have changed perceived usefulness of technology. Study 2 suggested the integration of technology and cognitive rehabilitation was feasible and acceptable, with a variety of technologies and features being used successfully to accomplish a range of goals. A research journal provided insights into successful integration of technology with cognitive rehabilitation: the importance of a visual component, intervention flexibility, and a strong therapeutic alliance. The research journal also suggested that integrating cognitive rehabilitation and technology helped create environments that increased quality of life.
Thesis
(2024-07-24) Li, Lin; Lindenschmidt, Karl-Erich; Gutwin, Carl; Brinkmann, Markus; Jardine, Tim; Davison, Bruce
The abstract of this item is unavailable due to an embargo.
Diversity and structure of Late Cretaceous–Paleogene crocodyliform communities in southern Saskatchewan, Canada
(2024-07-24) Lindblad, Kaitlin; Mangano, Gabriela; Bamforth, Emily; Buatois, Luis; Eglington, Bruce; Hastings, Alex
Crocodyliform fossils of extinct relatives and members of modern families are common finds in southern Saskatchewan, Canada, spanning a largely continuous interval of the Upper Cretaceous and Paleogene. Although this location represents the northernmost known extent of many well-known taxa, only a few individuals are documented in the literature, demonstrating the importance of Saskatchewan to the study of early crown-group crocodylians from the area. This study approaches these fossil crocodyliforms from multiple angles; describing previously unpublished specimens, examining the stratigraphy and taphonomy of the most notable quarries, and identifying patterns of the microvertebrate sites of the latest Maastrichtian Frenchman Formation in a case study to learn about the composition, ecology, and taphonomic overprints of this crocodyliform community. Almost all crocodyliforms known from Alberta and the northern United States over the span of the Campanian to late Eocene are confirmed to be (or are likely) present in Saskatchewan, including multiple species of Borealosuchus, and various alligatoroid genera. Borealosuchus is the most common and longest-lived crocodyliform represented, persisting in Saskatchewan from about 66.3 to 59 million years ago. This genus is preserved in a variety of freshwater habitats over this time interval, demonstrating resilience and flexibility in the face of ecosystem changes that occurred across the Cretaceous–Paleogene (K–Pg) boundary and well into the Paleocene. Most Frenchman Formation microsites show an elevated number of osteoderms and teeth compared to fragments of skeletal material. This likely represents a preservation bias due to each individual animal having hundreds of osteoderms and teeth. Additionally, the smaller teeth are the most common, likely representing an abundance of small and/or young individuals shedding teeth at a greater rate. This resembles the population structure in other extinct and modern crocodyliform communities, suggesting similar life histories.
On a class of extended toroidal Lie algebras coming from untwisted affine Yangians
(2024-07-24) Ha, Dat Minh; Wendlandt, Curtis; Weekes, Alexander; Rayan, Steven; Szmigielski, Jacek
The purpose of this thesis is to construct so-called \say{$\gamma$-extended toroidal Lie algebras}. Originally, these $\gamma$-extended toroidal Lie algebras were created to aid with endowing \say{toroidal Lie algebras}, i.e. universal central extensions: $$\toroidal$$ of the Lie algebras of the form: $$\g[v^{\pm 1}, t^{\pm 1}] := \g \tensor_{\bbC} \bbC[v^{\pm 1}, t^{\pm 1}]$$ (so-called \say{double-loop algebras}), where $\g$ is a finite-dimensional simple Lie algebra over $\bbC$, with Lie bialgebra structures, and the point of doing this is so that toroidal Lie bialgebras can be recognised as classical limits of certain quantum groups known as affine Yangians. Per the general theory of quantisations, such a Lie bialgebra structure on $\toroidal$ can by constructed by means of Manin triples of the form: $$(\toroidal, \toroidal^{\positive}, \toroidal^{\negative})$$ In doing so, we must endow $\toroidal$ with an invariant bilinear form satisfying some conditions, but an issue that we will encounter in attempting this is that, any invariant bilinear form on a universal central extension is necessarily \textit{degenerate}. As such, we are motivated to enlarge toroidal Lie algebras into $\gamma$-extended Lie algebras: $$\extendedtoroidal$$ and this is done in such a way that the resulting larger Lie algebras can then be endowed with \textit{invariant} symmetric bilinear forms that are also \textit{non-degenerate}. Importantly, the construction of these bilinear forms depends entirely on a certain linear map: $$\gamma: \bbC[v^{\pm 1}, t^{\pm 1}] \to \bbC$$ (and hence the name of our Lie algebras). We shall see that the Lie algebras $\extendedtoroidal$ all arise as \say{twists} of the semi-direct product $\toroidal \rtimes \der_{\gamma}(\bbC[v^{\pm 1}, t^{\pm 1}])$ by Lie $2$-cocycles $\sigma \in Z^2_{\Lie}(\der_{\gamma}(\bbC[v^{\pm 1}, t^{\pm 1}]), \z(\toroidal))$, with $\der_{\gamma}(\bbC[v^{\pm 1}, t^{\pm 1}])$ being a certain ($\Z^2$-graded) Lie subalgebra of the Lie algebra $\der(\bbC[v^{\pm 1}, t^{\pm 1}])$ of all derivations on $\bbC[v^{\pm 1}, t^{\pm 1}]$. Moreover, we will see that there is a readily available example of such a $2$-cocycle giving rise to a $\gamma$-extended toroidal Lie algebra that is \textit{not} isomorphic to the aforementioned semi-direct product.
Bridging the Gap Between Lidar, Thermal, and Multispectral Remote Sensing for Irrigation Scheduling Applications
(2024-07-24) Cline, Emily G; Helgason, Warren D; Bueckert, Rosalind A; Noble, Scott D; Derdall, Evan; Smith, Laura
Irrigation reduces the soil moisture deficit in crop production; however, the Canadian Prairies is a semi-arid landscape with limited water resource availability, requiring careful application of water management practices. This thesis studies methods to reduce irrigation water consumption in agricultural fields with complex soil texture dynamics using the water deficit index (WDI) to indirectly detect crop water stress and measure root zone soil moisture. This index is an extension of the crop water stress index (CWSI) that uses remotely sensed surface temperature (Ts) in addition to the fraction of vegetation (fc) to estimate the crop evaporative fraction through manipulation of the available energy balance equation. Seasonal and spatial relationships between WDI and volumetric water content (VWC) over a wheat and pea crop were observed at a study site with heterogeneous soil textures over two growing seasons; wheat was planted in the first growing season, and pea was planted in the second. Ten ground-based stations were used to observe average daily fluctuations in WDI by measuring Ts and deriving fc using the normalized difference vegetation index (NDVI). Results indicated that deep layers of sandier soils are more likely to cause high variations of WDI during dry-down events. Remotely sensed WDI agrees with measured eddy covariant energy fluxes at the beginning to middle of the growing season; however, NDVI is impacted by leaf senescence after seed fill for both crops, reducing the accuracy of WDI later in the growing season because of errors in fc. Light detection and ranging (lidar) is introduced as a more sophisticated approach to obtain fc and is used as a method to validate WDI obtained using NDVI canopy fraction using unpiloted aerial vehicle (UAV) imagery during the pea growing season. Canopy fraction obtained using NDVI UAV imagery produced WDI values that agreed with canopy fraction derived using lidar demonstrating that NDVI provides accurate fc for the calculation of WDI. A technical analysis was performed to assess the accuracy of crop height models obtained using Structure from Motion (SfM) photogrammetry techniques compared to lidar. Photogrammetry crop height models were obtained using high-quality red-green-blue (RGB) imagery with accurate real-time kinematic (RTK) positioning, or RGB, multispectral and thermal imagery georeferenced using 3D ground control points (3D-GCPs); thermal and RGB SfM crop height models georeferenced using 3D-GCPs were inaccurate when compared to lidar crop heights. Further analysis was performed on identifying the empirical relationship that existed between lidar-derived fc and crop height for wheat and pea crops. The ability to track seasonal and spatial relationships between WDI and VWC, and the ability to obtain crop height models using multispectral imagery provides exciting progress at bridging the gap between thermal, multispectral and lidar remote sensing for irrigation scheduling applications.
Seed Germination to Improve Air Classification Efficiency and Diversify Functional and Nutritional Attributes of Protein and Starch Streams of Pulses
(2024-07-24) Abid, Areha; Ai, Yongfeng; Nickerson, Michael Todd; Acharya, Bishnu; Wang, Ning; Vargas, Ana
The abstract of this item is unavailable due to an embargo.
WINTER AND MOLECULAR ECOLOGY OF THE AMERICAN DOG TICK, Dermacentor variabilis, ON THE CANADIAN PRAIRIES
(2024-07-23) Yunik, Matthew E.M.; Chilton, Neil; Benson, James; Dergousoff, Shaun; Hill, Janet; Todd, Chris; Wilson, Ken; Trout Fryxell, Rebecca
The range of the American dog tick, Dermacentor variabilis, is expanding northwards into the Boreal transition ecoregion, where ticks experience colder winter temperatures. This thesis examined if adult ticks in a recently established population (Lizard Lake Community Pasture [LLCP]) near the edge of the species range survive over winter, have greater cold-hardiness than ticks in other populations, and if there are differences in the bacteria within in their microbiomes that may enhance overwinter survival. The results showed that the overwinter survivorship in outdoor enclosures was lower at LLCP than the established population at Sandy Hook. Also, significantly more females survived than males. Although the supercooling points (SCP = the temperature at which ticks freeze) of females did not differ from those of males, ticks from Sandy Hook had a colder SCP than ticks from LLCP, suggesting that adults at Sandy Hook are better adapted to deal with the environmental conditions they experience than those at LLCP. Also, the SCPs of lab-reared adults had a unimodal distribution, whereas those of questing adults in the field in early spring was bimodal, the later indicating the existence of two adult cohorts. By summer, there was a normal distribution of SCP values from questing ticks, suggesting a loss of some adults from the population. Therefore, environmental factors have an important impact on the SCP and off-host survival of ticks. Interestingly, bacteria present in the microbiomes of adults from LLCP during late summer were not different from adults that survived overwintering based on next-generation sequencing data. However, quantitative PCR analyses revealed that Francisella-like endosymbionts (FLEs), which are obligate tick mutualists, were more abundant in female ticks than males, especially for individuals that overwintered. Also, ticks infected with Rickettsia montanensis had a greater relative abundance of Rickettsia than FLEs, and a lower FLE abundance than ticks not infected R. montanensis, suggesting a negative interaction between these bacteria. The knowledge gained from this study has important implications for predicting range expansion by D. variabilis, and provides the foundation for future studies on the physiology and molecular ecology of the American dog tick.
Wildfire Severity, Recovery, and Grazing Management in the Dry-Mixed Grasslands of Southern Alberta and Saskatchewan
(2024-07-23) Grover, Sera Anne; Lamb, Eric; Lardner, Bart; Carlyle, Cam; Prager, Sean; Guo, Xulin
In the fall of 2017 two wildfires in southern Alberta and Saskatchewan burned approximately 28 000 hectares under extreme weather conditions. These fires completely burned over many ranches, and raise many questions, including how the fire severity and recovery are affected by topographic and soil gradients, and how biomass production and plant species diversity recover including the role of grazing management decisions in recovery. Fire severity in relation to slope, aspect, and available fuel was assessed utilizing the bare soil index (BSI) by calculating the difference between the amount of soil exposure from pre-fire to immediately after the fires. Recovery of biomass production in relation to fire severity, land capabilities, potential land productivity, and solar heat load was assessed utilizing the normalized difference vegetation index (NDVI) to compare post-fire vegetative greenness to that of baseline pre-fire peak biomass greenness. Recovery of live biomass and species metrics with and without fire and grazing were assessed using a factorial randomized complete block design. I found that fire severity increased with increased slope and decreased vegetative greenness. Fire severity was highest in areas with slopes steeper than 15 and aspects that were within the 45 flanks of the dominate wind direction. Recovery of biomass was best in areas of moderate fire severity and solar heat load. The complete recovery of live biomass was noted by year three of the study and the complete recovery of litter was not noted by year five. Grazing has no significant effect on recovery of either biomass or species metrics.
Septic arthritis in western Canadian feedlot cattle: a comparison of antimicrobial treatment options and a description of the bacterial communities present in infected joints
(2024-07-23) Warr, Brian Nelson; Jelinski, Murray; Ruzzini, Tony; Schwartzkopf-Genswein, Karen; McAllister, Tim; Harding, John; Erickson, Nathan
Septic arthritis (SA) presents health, welfare, and production concerns in western Canadian feedlots. Septic arthritis has the highest case fatality rate of lameness causes and little information exists on treatment options. Mycoplasmopsis bovis is often the primary etiological agent of SA in feedlot cattle and H. somni has also been implicated. Furthermore, animals with SA often have concurrent chronic pneumonia. As a result, SA treatment protocols commonly recommend parenteral administration of antibiotics that have label claims for bovine respiratory disease (BRD) but with little efficacy information available for treatment of SA. The objectives of this two-year investigation were to 1) compare the health outcomes of three commonly administered antibiotics for the treatment of SA and 2) determine the microbiota of synovial fluid collected from SA joints. The treatment study consisted of trained pen riders identifying SA cases from the fall-placed calf population over a two-year period at four commercial feedlots. Cases were randomly allocated to three antibiotic treatments: florfenicol (FFN), oxytetracycline (OXY), and tulathromycin (TUL). The health outcomes monitored to 90 d post allocation included SA relapse treatments (first and second), BRD treatment, infectious mortality (BRD, H. somni, SA), and SA only mortality. Additional outcomes were early shipment for salvage slaughter (railer) and the sum of infectious mortality events and railer events (total fall out). In order to describe the microbiota of synovial fluid from SA cases, synovial fluid samples (n = 137) were collected over the same two-year period in the fall placed calf population at 11 commercial feedlots. The samples were collected via arthrocentesis from joints with and without SA and from antemortem and postmortem specimens. After collection, the samples were frozen at -20°C and then -80°C until DNA extraction process was completed. Samples underwent 16S rRNA gene sequencing using an Illumina platform and analysed using DADA2, QIIME2R, and the R-package. Amplicon sequence variants (ASVs) were based on 99% similarity and taxonomy was assigned using the SILVA reference database. Samples with less than 20,000 reads were omitted from the final analysis. In total, 251 eligible cases were allocated to the treatment comparison and no differences (P > 0.05) were noted for the morbidity outcomes of first and second SA relapse and BRD. Likewise, no differences (P > 0.05) were noted in the mortality outcomes, railer events, or total fallout. Time to event analysis was conducted with no differences (P > 0.05) noted for any of the health outcomes. From the original 137 synovial fluid samples, 66 met technical criteria to be included in the final analysis. Mycoplasmatota accounted for 96.6% of the phyla abundance and Mycoplasmopsis accounted for 94.8% of the abundance at the genus level. Samples from SA cases were noted to have a higher abundance of Mycoplasmopsis (P=0.033) and a lower Shannon diversity index compared to controls (P=0.018). Postmortem samples had a higher abundance of Mycoplasmopsis (P = 0.015) and a lower Shannon diversity index than antemortem samples (P = 0.001). Only 8.5% of the ASVs assigned to Mycoplasmopsis were assigned to the species level with M. alkalescens and M. wenyonii present in 10 and 2 samples, respectively. Histophilus did not rank in the top 15 genera found and the Pasteurellaceae family (of which Histophilus belongs) only accounted for 1% of ASV assignments. The lack of differences in health outcomes by treatment indicate that there is no economic advantage to using a particular treatment; the most cost effective product would be the least expensive to purchase. A study limitation was the lack of production performance data, which may have revealed differences by treatment. The lack of difference observed in the three antimicrobial products also introduces a question of antimicrobial efficacy for SA, it is possible that the products were equally ineffective. Conclusions from the microbiota study of joints with SA in the western Canadian feedlots are that Mycoplasmopsis is the predominant genera. Also of interest was that Histophilus was not found in the top 15 genera from the samples in this study. The lack of Histophilus is surprising because it has been considered an etiological agent for feedlot SA cases. The presence of M. alkalescens and M. wenyonii in SA joints suggest further research is needed to understand the impact of Mycoplasmopsis species other than M. bovis in the role of SA.
Assessment of Precision Irrigation on Potatoes in Southern Alberta
(2024-07-23) Harding, Adele; Schoenau, Jeff; Helgason, Warren; Si, Bing; Appels, Willemijn
The abstract of this item is unavailable due to an embargo.
Development, Analysis and Evaluation of the LIFE Prototype Instrument
(2024-07-23) Runge, Ethan; Bourassa, Adam; Degenstein, Doug; Toohey, Matthew; Steele, Tom; Milne, Doug; Smolyakov, Andrei; Bradley, Michael; Sica, Robert
There exists in the upper troposphere/lower stratosphere (UTLS) region of the atmosphere an identified observational gap in measurements, leading to large uncertainties in climate models. This region is crucial to understanding the climate of our planet due to the strong effect of dynamic, chemical and radiative processes within. In recent decades, infrared Fourier Transform Spectrometry has been identified as, and demonstrated to be, a prime candidate for remote sensing techniques with the necessary spectral, spatial and temporal resolution to combat the present scarcity of these critical observations through instruments such as MIPAS and GLORIA. The Limb Imaging Fourier Transform Spectrometer Experiment (LIFE) aims to build upon the legacy of these instruments with a design comprised of commercially available components and with greatly reduced complexity and cooling requirements, with minimal impact to measurement quality. This prototype instrument primarily targets the important greenhouse gases H$_2$O, O$_3$, CH$_4$ and N$_2$O and seeks to obtain vertical trace gas profiles for each by taking infrared measurements in the 700 to 1400 cm$^{-1}$ wavenumber range from a balloon-based platform. The design, characterization and calibration of the original instrument is the subject of a publication included in this work that details the instrument concept and operation, design principles and initial results from a 2019 demonstration flight from Timmins, Ontario. Additional aspects of the instrument design such as practical considerations, optical alignment challenges, and supporting technologies and hardware are discussed as well. Analysis of the measurements taken during the demonstration flight indicate a completion of primary scientific goals through the determination of vertical trace gas profiles for each of the target species and HNO$_3$ additionally, which was the subject of a second publication. Though comparison of the LIFE vertical trace gas profiles with credible trace gas profiles from the ACE and MLS instruments confirmed the results, a number of weaknesses and areas of improvement for successor instruments are detailed, which will allow further closing of the observational gap and ultimately contribute to a better understanding of the UTLS and the climate of the Earth.
Detoxification of DON Contaminated Wheat by Fractional Pneumatic Separation, Near-Infrared Transmittance (BoMill), and Gaseous Ozone, and the Effects of Treated Grain on Broiler Chickens.
(2024-07-23) Taylor, Meghan Elizabeth Josie; Newkirk, Rex; Adewole, Deborah; Beaulieu, Denise; Brook, Ryan; Acharya, Bishnu
The mycotoxin deoxynivalenol (DON) caused by Fusarium spp. in cereal grains is a concern to the livestock industry, Current practices involve blending with clean grain to reduce overall DON content, but issues arise when clean grain has limited availability. These experiments were designed to determine: (1) if low DON wheat could be recovered from high DON wheat using specialized instruments; (2) the improvement of low DON grain recovery using two instruments in sequence and performance effects of sorted grain fed to broiler chickens; (3) the efficacy of gaseous ozone to reduce DON content in contaminated grains. The BoMill IQ (BoMill; BoMill AB, Sweden), a near infrared transmittance spectroscopy (NIT) single kernel sorter, was used with the Fusarium calibration to sort DON contaminated grain, as well as a GCS-200 grain cleaner (Grain Cleaning, LLC, MN, USA). In the first study, the BoMill was used to sort DON contaminated wheat and determine optimal calibration (Protein or Fusarium) and settings (HVK; hard vitreous kernel) to sort into eight fractions total, six sortable fractions with two unsortable fractions, and determine grain recovery under 5mg/kg DON of different wheats with different initial DON concentration. Experimental design was a CRD with four replications, data analyzed using least squares regression. The Fusarium calibration HHVK setting had 50.3% (P = 0.015), 29.0% (P = 0.001), and 1.8mg/kg (P = 0.068) recovered low DON wheat, rejection rate, and DON content respectively, which were intermediate to other settings and optimal compared to Protein calibration HVK setting 46.2% (P = 0.005) recovery, 35.6% (P = 0.001) rejection rate, and 1.6mg/kg (P = 0.001) DON content. Grain recovery (P<0.001) and rejection rate (P = 0.001) are dependent on initial DON concentration when sorting different sources of DON contaminated wheat. Using the BoMill technology could be an effective solution for regions with high DON incidence. In the second study a GCS-200 grain cleaner was used to sort and clean DON contaminated wheat by grain density, the intermediate DON content fraction was then sorted using the BoMill with optimal settings from the first study. Sorted and unsorted grain was used to formulate diets with graded amounts of DON for broiler birds to evaluate performance and intestinal morphology. Experimental design for grain sorting was a CRD with four replications. Experimental design for the broiler study was an RCBD with a 2 x 4 +1 factorial with ten replications. Fractional pneumatic separation grain recovery was 52.8, 42.7, and 58.8% with an average DON of 1.7, 1.5, and 1.0 mg/kg for three different initial DON wheats. Sequential sorting increased grain recovery between 10.5 to 19%. Dietary DON did not exceed 3.05 mg/kg. Bird performance and intestinal morphology were not different overall between treatments. In the third study, DON contaminated wheat was treated with gaseous ozone at different moisture contents and temperatures. Grain moisture was adjusted to 10.8, 15 or 20% moisture and grain treated with gaseous ozone for 24 hours at room temperature, then 20% moisture content wheat was temperature adjusted to 2°C or 29°C and treated with gaseous ozone for 24 hours. Statistical analysis was performed with one-way ANOVA using JMP. Increasing grain moisture content improved ozone degradation of DON by 6.7, 20.2, and 38.2% (P = 0.011) for 10.8, 15, and 20% moisture grain respectively. Temperature did not affect DON degradation when grain moisture was 20% (P > 0.10). Ozone can reduce DON content of wheat by 20 to 38% of wheat when grain moisture is above 15%. The key findings of the experiments were that the BoMill NIT Fusarium calibration can effectively sort and remove Fusarium damaged grain creating a fraction with reduced DON content. Sorting DON contaminated grain sequentially using a GCS-200 then BoMill improves grain recovery of low DON wheat. Sorted wheat can be used in broiler feed. Treating wheat with ozone can reduce the DON concentration at higher moisture levels.
Effect of yeast-fermentation of canola meal on nutrient digestibility, growth performance and health of Nile tilapia (Oreochromis niloticus) and rainbow trout (Onchorynchus mykiss)
(2024-07-22) Zhang, Chuyuan; Weber, Lynn; Drew, Murray; Brook, Ryan; Øverland, Margareth; Schwean-Lardner, Karen; Niyogi, Som; Adewole, Deborah; Kumar, Manoj
The rapid expansion of global aquaculture has intensified the needs for sustainable feed alternatives that can replace traditional marine-derived resources like fishmeal (FM) and fish oil. Currently, the use of fermented plant ingredients (FPIs), especially those through solid-state fermentation, in aquaculture production has been gaining significant interest. FPIs have shown potential to enhance nutrient profiles, reduce anti-nutritional factors (ANFs) and improve digestibility and growth in fish, thereby offering a sustainable solution to the challenges posed by conventional feeds. In the present thesis, a comprehensive meta-analysis was conducted to assess the impact of FPIs on the specific growth rate (SGR) across carnivorous, omnivorous and herbivorous fish species. The results revealed significant disparities in SGR when replacing fishmeal (FM) with FPIs in carnivorous fish (P < 0.05). In contrast, herbivorous, and omnivorous fish demonstrated promising adaptability to FPIs when replacing FM (P > 0.05). Additionally, FPIs resulted in better SGR in all fish species when comparing to their corresponding unfermented raw ingredients (P < 0.05). The nutritional effects of feeding unprocessed canola meal (RCM) and candida utilis-fermented canola meal (CFCM) were explored in two eight weeks trial with Nile tilapia and rainbow trout. After fermentation, the canola meal (CM) showed enhanced amino acid content with reduced anti-nutritional factors (ANFs). The crude protein (CP) digestibility of CFCM was significantly higher in rainbow trout (P < 0.05), while no significant difference was observed in nutrient digestibility Nile tilapia (P > 0.05). Results indicated that, while unprocessed canola meal (RCM) negatively influenced Nile tilapia growth, CFCM could be integrated up to 600 g/kg without any detrimental effects on growth performance. Additionally, rainbow trout displayed improved growth performance when fed CFCM over RCM (P < 0.05). The gene expression of specific cytokines in the distal gut of both fish species fed increasing dietary levels of RCM and FCM, were also examined. Results indicated that CFCM has potential as an alternative protein source when included up to 600 g/kg in diets for tilapia, while rainbow trout exhibited less adverse effects when fed FCM compared to RCM. In conclusion, FPIs, especially CFCM, hold significant promise in aquaculture. This suggests potential sustainable alternatives to FM without compromising fish growth and health.
The effects of periodic environmental enrichment at different life stages on the welfare and production of growing pigs
(2024-07-22) Tillotson, Abigail Irene; Brown, Jennifer; Schwean-Lardner, Karen; Seddon, Yolande; Beaulieu, Denise; Brook, Ryan; Johnson, Anna
It is known that the welfare of intensively raised pigs is improved when housed in enriched versus barren conditions, however, the interaction between enrichment and different life stages is largely understudied. The current study evaluated the influence of periodic enrichment during different life stages on welfare and production in growing pigs. A total of 240 pigs were housed in either Control (C) or Enriched (E) environments during Early life (0-9 weeks of age). The enrichment used in the current study was loosely crumpled newsprint with an added functional neurosensory liquid solution (Phytozen®). Upon moving to grow-finish (GF) for the remainder of the trial (Late life: 10-21 weeks of age), half of the pigs changed environments while half remained in the original environment resulting in four treatments for this stage: CC, CE, EC and EE. Growth was measured throughout life. Post-mixing aggression was evaluated after weaning and when moving to GF. Tail bites and body lesions were assessed throughout GF. A subsample of pigs was transported to the abattoir and carcass characteristics were analyzed. Statistical analysis of Early and Late life data was done using mixed linear models. Growth was increased with enrichment between 18-21 weeks of age (P=0.011). Post-mixing lesions were reduced in E pigs compared to C at weaning (P<0.001 for front and hind regions). The number and severity of tail bites were reduced with the provision of enrichment throughout life (P=0.077 and 0.032, respectively). Lesions during GF were reduced with the provision of enrichment during Late life (CE and EE < EC and CC; P<0.001 for all body regions). Enrichment provided during Early life resulted in greater carcass weights and lean depth (P=0.040 and P=0.031, respectively). The current study provides evidence that periodic enrichment is an effective way of reducing damaging behaviours throughout life. It was shown that pigs with access to enrichment throughout life had improved welfare and behaviour compared to pigs in all other treatments.
Disaster Risk Reduction in the Caribbean: Designing Optimal Policy Mixes
(2024-05-02) Dureau Sargsyan, Glenna M; Rayner, Jeremy; Coates, Kenneth; Hurlbert, Margot; Noble , Bram; Prytula, Michelle; Mamuji , Aaida
The abstract of this item is unavailable due to an embargo.
The differences in preferences among traditional vs. non-traditional lentil consumers in Canada
(2024-07-22) Faghihi, Negin; Hobbs, Jill; Slade, Peter; Lubieniechi , Simona; Hesseln , Hayley; Yang, Yang
Canada is a major producer and exporter of lentils, playing a significant role in the global pulse market. Understanding current and future trends in consumer preferences for lentils is crucial not only for the Canadian pulse sector, but also for lentil breeders and producers around the world. Canada is a highly diverse, multicultural country, making it an ideal setting to investigate lentil consumption patterns. This study uses survey data related to Canadian consumers with an ethnic tradition of lentil consumption as a proxy for understanding consumer behavior in other countries. By comparing the preferences for lentils among consumers who are culturally associated with lentil-consuming countries (traditional lentils consumers) and those who are not (non-traditional lentils consumers), the research aims to shed a light on the factors shaping the Canadian lentil market. An online survey of 1236 Canadian consumers was conducted to assess the differences in preferences among traditional versus non-traditional lentil consumers in Canada. Data are analyzed using Probit model. The results show that traditional lentil consumers, consumers for whom physical attributes of lentils are important, people who respect environmental issues, people who care about health, people who believe that lentils are easy to cook, and people who believe plant-based proteins like lentils are more affordable compared with meat, are more likely to consume lentils frequently. Also based on this research, consumers for whom animal rights are important, are less likely to consume lentils frequently. Consumers between 25-54 years old are more likely to be frequent lentil consumers relative to people 65 and above. Also, consumers with a postgraduate education level, are more likely to consume lentils frequently, relative to people with a bachelors’ degree. Also, avoiding consuming GMO-products and animal rights are more important for traditional consumers while physical attributes of lentils, convenience and affordability are more important for non-traditional lentils consumers.
Does pasture rejuvenation by sod-seeding with non-bloat legumes affect greenhouse gas emissions?
(2024-07-22) Liu, Can; Farrell, Richard; Peak, Derek; Baulch, Helen; Knight, Diane; Lemke, Reynald; Bourgault, Maryse; Wallace, Brian
Pasture rejuvenation through sod-seeding (i.e., the use a zero-till drill to place the seed directly into the soil) with non-bloat legumes, such as cicer milkvetch (Astragalus Cicer L.) or sainfoin (Onobrychis vicifolia Scop.), has emerged as a favored strategy for ranchers in the western Canadian prairies due to it being both time- and cost-effective. Meanwhile, this management also makes alterations to soil carbon and nitrogen cycling as well as to the diet of cattle grazing the pastures. Yet, our understanding on how these changes influence the greenhouse gas (GHG) budgets of the pastures remains limited. The goal of this research was to assess the impact of rejuvenating pastures by sod-seeding cicer milkvetch or sainfoin into a depleted meadow bromegrass-alfalfa mixed pasture on GHG emissions and their contribution to the total GHG footprint of the pasture system. To achieve this goal, field studies were conducted in east-central Saskatchewan, Canada to: (1) evaluate and compare GHG emissions between the rejuvenated pastures and the depleted pasture, and (2) quantify GHG emissions from dung and urine patches deposited by cattle grazing these pastures. Finally, the legume option resulting in the lowest GHG footprint was identified by integrating the GHG data with enteric methane (CH4) production by the cattle. The results indicate pasture rejuvenation through sod-seeding had only a minimal impact on soil-derived GHG emissions relative to the control (depleted) pasture, likely due to the limited soil disturbance associated with this method. At the paddock-scale, annual GHG emissions averaged 10.11 Mg CO2-C ha-1, 2.54 kg CH4-C ha-1 (uptake), and 0.18 kg N2O-N ha-1, with no significant differences among pasture types. However, changes in grazing diet resulting from the pasture rejuvenation were found to affect urine patch N2O emissions, with the highest cumulative N2O emissions associated with beef cattle grazing on the depleted pastures sod-seeded with cicer milkvetch. Surprisingly, this did not reflect differences in the available N content of the urines, suggesting a potential link to the presence of secondary metabolites such as hippuric acid. Notably, the dung and urine patches yielded distinctly different N2O emission factors, averaging 0.03% and 0.26%, respectively. Within the pastures, landscape position emerged as a dominant regulatory factor for CO2 and CH4 emissions—with the lower slope positions exhibiting the highest CO2 emissions and the lowest CH4 uptake, likely due to denser vegetative cover in these areas due to an accumulation of soil moisture. Such landscape-scale patterns remained unaffected by dung/urine deposition. Partial C footprints for the pastures (based on non-CO2 emissions from the soil, cattle excreta, and enteric CH4) were developed and it was determined that there were no significant differences between the rejuvenated and depleted pastures. Averaged across pastures, the C footprint was 970 kg CO2eq ha-1 yr-1, with enteric CH4 being the largest contributor to the footprint. Insights gained from this study will be valuable for ranchers and policymakers in developing sustainable pasture management strategies.

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