1722 research outputs found
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The Detection of Fusarium Head Blight in Multiple Species of Wheat Using a Multispectral UAV in Southern Manitoba
No full textFusarium Head Blight (FHB) is a fungal disease that affects cereals such as wheat, severely damaging the plant, reducing its yield and value, and potentially rendering it unsafe for human or animal consumption. Detection of FHB in wheat fields is essential due to the threat it presents to Canada’s agricultural production. UAV’s and remote sensing techniques have been adopted within precision agricultural approaches for canopy scale detection of the disease. These approaches have focused on the detection of the disease in a singular species of wheat in an experimental field. The goal set out by this thesis is the detection of FHB across a diversity of wheat species using a multispectral UAV in an experimental field, and the transfer of the detection model to a monoculture commercial wheat field. We collected multispectral UAV imagery, and ground-based measures of the state of FHB in randomly sampled plots in both the experimental and commercial fields. A selection of 15 Vegetation Indices (VIs) were then extracted from the multispectral imagery, chosen for their past FHB detection performance. Three supervised machine learning classification models were selected, support vector machines, random forest, and extreme gradient boosting based on their prior applications in disease detection in wheat. We determined a set of Key VIs sensitive to FHB across wheat species using Spearman’s Ranked correlation, feature importance in RF and XGB models, and replacement sampling. These key VIs along side the ground-based measures were used for the training and testing of the FHB detection models, and applied to the experimental and commercial field. In our results Green Leaf Index (GLI), Anthocyanin Reflectance Index (ARI), Plant Senescence Reflectance Index – red-edge (PSRI-RE), and Enhanced vegetation index (EVI) emerged as the Key VIs for their effectiveness across wheat species. Amongst the three models, XGB offered the greatest overall accuracy at 87% for disease detection, but all models were successful in distinguishing healthy and FHB diseased wheat in the experimental field. When applied to the commercial field, the models successfully distinguished healthy from non-healthy stressed wheat, but had difficulty with the interrow spacing from the experimental site. In this thesis we successfully detected FHB across a diverse collection of wheat species, and identify challenges when transferring from an experimental to commercial field.Master of Science in Environmental and Social Chang
The Effects of Short Chain Fatty Acids on Growth Factors and Pro-Inflammatory Cytokine Production in Enteric Glial Cells
No full textEnteric glial cells (EGCs), the major cell type in the enteric nervous system, are involved in maintaining intestinal homeostasis by secreting growth factors that attenuate intestinal inflammation, support enteric neuronal health, and enhance the intestinal epithelial barrier. However, when exposed to inflammatory stimuli, EGCs become reactive and secrete pro-inflammatory cytokines that may be detrimental to the intestinal barrier. Recently, butyrate, a short chain fatty acid (SCFA) characterized as a histone deacetylase (HDAC) inhibitor, has been shown to elevate expression of growth factors and reduce expression of cytokines in intestinal epithelial cells and glia of the central nervous system. However, it remains unknown if SCFAs affect EGCs in a similar manner. This study investigated the following: (1) if treating EGCs with SCFAs influences production of growth factors; (2) whether SCFAs alter pro-inflammatory cytokine production in EGCs. We hypothesized that SCFAs enhance levels of growth factors and inflammatory cytokine levels in EGCs. An established rat enteroglial cell line was treated with butyrate (0-10 mM), propionate (0-10 mM) or pharmacological HDAC inhibitors suberoylanilide hydroxamic acid (SAHA) or trichostatin A (TSA) (0.1 mM-10 mM) for 8h-72h with or without IFNg (10 mg/mL) to stimulate EGCs into their activated phenotype. Changes in growth factors (GDNF & TGF-b1) and pro-inflammatory cytokines (IL-6, IL-1b, and TNFa) in EGCs were assessed using qPCR and western blotting. Both butyrate and propionate elevated GDNF transcript abundance in EGCs, whereas SAHA and TSA reduced GDNF transcript abundance. At the protein level, butyrate and propionate did not alter GDNF whereas both SAHA and TSA reduced GDNF protein levels. Differences could be explained by cytotoxic effects of prolonged exposure of cells to SAHA and TSA. In contrast butyrate, propionate, and SAHA reduced TGF-b1 transcript abundance and protein levels in EGCs whereas TSA had no effect. Furthermore, treatment with SCFAs significantly lowered TNFa transcript abundance in EGCs. However, at the protein level, only butyrate was effective at lowering TNFa. In contrast, SCFAs elevated IL-6 transcript abundance in EGCs but had no effect on IL-6 protein. Neither butyrate nor propionate altered IL-1b protein levels in EGCs. Collectively, these results suggest that the effects of SCFAs on functional aspects of EGCs varies depending on the type of growth factor and pro-inflammatory cytokine being assessed. Overall, the data presented in thesis provides a new understanding of how SCFAs modify EGCs function, which advances the understanding of EGCs in intestinal physiology and glial cell biology.Master of Science in Bioscience, Technology, and Public Polic
On Temporal Bipartite Graphs and Their Application in Disease Spread Prediction
Full text linkThe original temporal bipartite graph is flawed in the context of disease spreading models as it does not account for concepts such as virus incu-bation and recovery periods. In this thesis, a new graph structure, referred to as the improved temporal bipartite graph is introduced with these two concepts incorporated to enhance accuracy in predicting disease spreading. To facilitate arbitrary reachability queries, another concept, the transmission graph, is introduced. It is derived from a temporal bipartite graph based on a series of reachability query evaluation. We distinguish between two types: single-path transmission graph and multi-path trans-mission graph. Based on them, four algorithms are proposed for evaluating reachability queries on a temporal bipartite graph, with a label-based technique used to achieve high efficiency. Both single-path transmission graphs and multi-path transmission graphs are in fact a kind of extension of the reachability query evaluation. By establishing indexes over them, the reachability query evaluation for disease spreading prediction can be very efficiently conducted.Master of Science in Applied Computer Science and Societ
Examining the effects of elevated carbon dioxide on Japanese medaka (Oryzias latipes) behaviour and the use of alarm cue responses for ecologically relevant behavioural studies
Full text linkElevations in atmospheric carbon dioxide (CO2) have been measured by experts for decades. These atmospheric elevations cause changes in aquatic environments as increased CO2 reduces pH. Acidification has been shown to cause changes to the behaviour of many fish species including reducing homing behaviour, foraging behaviour, and predator avoidance. Many studies have analyzed the effects of CO2 on fish behaviour, however, wide variation in responses between species is known. Moreover, not many studies have analyzed potential acclimation to CO2. The aim of chapter 2 was to identify whether elevated levels of CO2 affect behaviours of Japanese medaka (Oryzias latipes) and whether they acclimate over time to these elevated levels. To test this, I exposed a total of 300 fish to varying levels of CO2 (2500 µatm, 5500 µatm, 8500 µatm) with different exposure times (0, 5, 10, 15, 20 d). After each exposure period, I performed two behavioural tests, the first, where I placed individual fish into circular arenas, measured cumulative distance moved, immobility duration, and percent of time spent in the outer zone. For the second test, I placed 6 fish at a time into a small tank where half of the tank was marked with a black line. I then measured the amount of time spent over the line and the number of crosses above the line for individual fish. I also performed another behavioural test only at the highest CO2 treatment where I placed 3 fish into one circular arena and measured the same parameters to identify whether solitude influenced behaviour. My results showed that CO2 at 8500 µatm affects behaviour of Japanese medaka only in a group setting. There was also evidence of acclimation around day 10 to 20; however, increased individual variation was seen. My study suggests that CO2 changes behaviours of Japanese medaka under certain conditions, and thus Japanese medaka may be affected by rising atmospheric CO2. Although it is important to analyze basic behaviours of fish to determine baselines, it is also important to study ecologically relevant behaviours to understand what is going on in the environment. Alarm cue behaviours act as a good way to analyze predator avoidance behaviours of prey fish. Although a lot of work has been done in this area, not a lot of studies have analyzed these behaviours in Japanese medaka and new methods for using synthetic cues are still being studied. The aim of chapter 3 was to investigate whether Japanese medaka respond behaviourally and neurophysiologically to both synthetic alarm cues and skin extracts. To quantify behavioural responses, I exposed lab-reared Japanese medaka to three different concentrations of both a synthetic cue (hypoxanthine-3-N oxide) and a prepared natural skin extract and then monitored fish for cumulative distance moved, immobility duration, and the percent of time spent in the outer zone of the arena. To quantify neurophysiological responses, I exposed Japanese medaka to three concentrations of the synthetic cue or natural skin extracts for 5 d and then removed the brains and measured acetylcholinesterase (AChE) activity. There were no changes in behaviour or AChE activity for fish exposed to either cue, which suggest two things: one, Japanese medaka lack the ability to sense the cues; or two, the cues were not appropriate for Japanese medaka. Identifying differences in the structure and function of olfactory systems of Japanese medaka and their putative alarm cue chemical structure may help to explain my results.Master of Science in Bioscience, Technology, and Public Polic
Opportunities for Meaningful Engagement: A Canadian Perspective on Regulatory Tribunals
No full text"Funding was provided by the Office of Consumer Affairs to the Consumers’ Association of Canada – Manitoba."https://www.taylorfrancis.com/chapters/oa-edit/10.4324/9781003388227-12/opportunities-meaningful-engagement-patricia-fitzpatrick-heather-fas
UWinnipeg Feedback for Tri-Agency Open Access Policy Review
No full textSubmission for the 2024 Tri-Agency Open Access Policy on Publications Review. https://science.gc.ca/site/science/en/interagency-research-funding/policies-and-guidelines/open-access/presidents-canadas-federal-research-granting-agencies-announce-review-tri-agency-open-access-polic
Missing Patients Research Guide and Video Modules
Full text linkThis Missing Patients Research Guide contains directions for finding out more about Indigenous patients who entered tuberculosis (TB) sanatoriums and hospitals in Manitoba and never returned home. Part One of the guide presents helpful start-up information. First it explains how to gather useful details including names, dates, and locations that will help in the search as well as how to move forward with your research. Then it outlines three useful “Research Tips”: all of the various names of TB treatment hospitals in Manitoba commonly attended by Indigenous patients; instructions for undertaking database searches using keywords; and techniques for linking information between Indian Residential Schools and hospitals. Last, a “Research Case Study” demonstrates some of the techniques and challenges you may encounter when researching Vital Statistics and Indian Residential School records by looking at the lives of three TB patients, Elie Caribou, Joseph Michel, and Albert Linklater. Part Two of the guide explains how to research the location of patient burials associated with nine hospitals where Indigenous patients were treated in Manitoba, including treatment for TB: Dynevor Indian Hospital, Clearwater Lake Indian Hospital, Brandon Indian Sanatorium, Ninette Sanatorium, St. Boniface / St. Vital Sanatorium, Fort Churchill Military Hospital, Norway House Indian Hospital, Fisher River Indian
Hospital and Pine Falls Indian Hospital at Fort Alexander. Some of the general research information found in Part One is repeated under the individual hospitals and sanatoriums along with the specific information that may assist in searching for missing patients at each location. At the end of the guide, in Appendix A, you will find a checklist to help you in your research. Appendix B provides contact information for the organizations mentioned in this guide so that you can reach out by phone, email, or mail. Appendix C discusses accessing the records held by The National Centre for Truth and Reconciliation."This guide draws on research supported by the Social Sciences and Humanities Research Council, the Canadian Institutes of Health Research, the Province of Manitoba, the Manitoba Lung Association, and the University of Winnipeg.
Contribution to Six Seasons Newsletter December 2024
No full textBrief contribution on material culture research for community magazine of the Six Seasons of the Asiniskaw Ithiniwak Project, edited by Melanie Braith, forthcoming, non-refereed.The Six Seasons Project of Asiniskaw Īthiniwak project is supported in part by funding from the Social Sciences and
Humanities Research Council
An All-In-One, Low-Cost Photogrammetry Rig for 3D Plant Modelling and Phenotyping
No full textPhotogrammetry, the science of generating 3D models of objects from photographs, offers a comprehensive method for acquiring, studying, and analyzing detailed information about the structure of objects. Utilizing the cost-effective Structure from Motion (SfM) technique, it is possible to generate 3D models from numerous 2D images taken from various angles. Point clouds represent a standard format for 3D data generated by depth sensors such as LIDARs and RGB-D cameras. Despite their utility, high-quality 3D scanners, costing upwards of 2,600, to support agronomists, plant scientists, and breeders. This work outlines the development of our device, which integrates a multi-camera system featuring the Arducam 64MP Autofocus Quad-Camera Kit, a rotary table from Ortery, and a Raspberry Pi for comprehensive control and processing. Our scanner efficiently captures detailed plant 3D data, offering a valuable tool for non-destructive, automatic, and robust 3D phenotyping. It is possible to use our device across various applications, including growth monitoring and the extraction of plant traits. Specifically, we have leveraged the device to measure the canopy volume of different wheat genotypes by computing the convex hull from the 3D data. Furthermore, through our photogrammetry rig, we have developed a high-throughput, quantitative trait index for wheat to identify distinct planophile and erectophile canopy architectures.MitacsMaster of Science in Applied Computer Scienc
Determination of the Effect of Minor Chemical Modification of β-Galactosidase on Electrophoretic Mobility and Development of a Stereospecific Method for the Analysis of Tartaric and Malic Acids
Full text linkStudies in single molecules are a relatively new field of research in biochemistry. Research in this area looks at how enzyme activity can vary compared to a typical ensemble environment. This field of study covers a wide variety of environments where single molecules can be located, such as in a gaseous mixture in spectroscopy experiments or inside the body. Single molecule enzymology has grown greatly because there has been an interest in technology to measure the activity of single molecules. Ensemble methods of analysis only provide information about the average state of a large number of molecules, whereas in methods such as capillary electrophoresis, the researcher can see the active state of each individual protein molecule. However, dynamic conformation changes in ensembles can mask individual changes in structure or any small changes that do not conform to the average. Suppose one is only looking at the state of a single enzyme. In that case, there is a lot of information that can be gained from that single enzyme such as conformation and activity; as well as intermediates can easily be detected. An important aspect of these studies to note is that in large scale enzyme studies, there are also interactions between the molecule of interest and the solvent. The other molecules in solution are not typically of interest but they can easily influence the characteristics of the molecule of interest due to chemical bonding. This bonding is important for catalysis studies but is not vital to any studies of single enzyme molecules, as the substrate bonding data is not being collected. Related to this, during the reaction in a large-scale enzyme setting, there are instances where multiple turnovers may occur, and also, not all the enzyme molecules will be in the same active state during these reactions. This is not a concern in single molecule reactions as the reaction sequence of each enzyme molecule can easily be observed. This is particularly important in reactions that involve protein folding and DNA synthesis. Studies have utilized the enzymes β-galactosidase and alkaline phosphatase, and have shown that many different types of information can be gathered from the study of an individual molecule. For example, a study has looked at how temperature affects the active conformations of these enzymes. This study showed that an enzyme has many different active conformations that can be observed, and that heating the enzyme can induce a conformational change. However, as is already known, an enzyme can only be heated to a certain point, as there is a process of denaturation.NSERC; University of WinnipegMaster of Science in Bioscience, Technology, and Public Polic