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Master of Science (M.Sc.)
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- Resource Type:
- Thesis
- Creator:
- Yaremchuk, Danya Daria
- Abstract:
- Lodgepole and jack pine form a mosaic hybrid zone in western Canada. Introgression occurs between lodgepole and jack pine through this hybrid zone by repeated backcrossing with advanced generation hybrid progeny. Using environmentally-associated SNPs identified by redundancy analyses, we examined patterns of introgression between the northern and southern extents of this hybrid zone to identify differential introgression. Through genomic cline analyses, we found extensive introgression of these SNPs through the hybrid zone. Twenty-eight SNPs had significantly different patterns of introgression between the northern and southern extents. Fine-scale patterns revealed several SNPs that were introgressing more frequently than expected, suggesting adaptive introgression. We found that adaptive introgression is occurring more frequently in the northern hybrid extent compared to the southern hybrid extent, suggesting different environmental pressures. Using gene annotations and major allele frequency maps, we identified evidence of differing environmental pressures resulting in putative local adaptation within this hybrid zone.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Biology
- Date Created:
- 2023
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- Resource Type:
- Thesis
- Creator:
- Heiratifar, Noora Donna
- Abstract:
- In the present thesis, we used a rodent analogous coronavirus, murine hepatitis virus (MHV), in culture to directly assess its impact on astrocytic and microglial cells. Given the increasing importance of the brain neurotrophic factor (BDNF)-TrkB signaling system in glial functioning, we also assessed whether the unique TrkB.T1 truncated isoform (the only BDNF receptor on astrocytes) would modulate glial reactivity to MHV viral infection. Our results largely support the notion that MHV readily infects astrocytes and caused a degree of toxicity of these cells. The addition of microglia to the astrocytic culture modulated the magnitude of this effect and greatly increased pro-inflammatory cytokine release. Furthermore, TrkB.T1 deficiency appeared to greatly reduce astrocyte viability and microglial morphology. These data may have useful implications for better understanding the nature of glial responses to coronaviral infection and the importance of TrkB in such responses.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Neuroscience
- Date Created:
- 2023
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- Resource Type:
- Thesis
- Creator:
- Bornheimer, Jacob
- Abstract:
- Autophagy is the intracellular process of isolating, enveloping, and recycling cell matter. Beclin-1 is a protein that acts as a lynchpin in the autophagic process. Animals lacking Beclin-1 are embryonically lethal, and knockout of Beclin-1 causes a reduction in adult hippocampal neurogenesis. The dentate gyrus (DG) is normally home to ongoing neurogenesis, which is thought to mediate pattern separation and memory encoding. First, I test a new protocol for the TUNL task. To assess whether a behavioural phenotype of Beclin-1 nKO is apparent, on the second experiment I compare TUNL performance between WT and KO mice. The new protocol for the TUNL task produces a reliable measure of pattern separation. Beclin-1 nKO reduced DG neurogenesis by 40% compared to WT. No difference between the WT and KO mice in TUNL task performance (pattern separation ability) was found but KO mice had lower activity in the CA1 during the task.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Neuroscience
- Date Created:
- 2023
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- Resource Type:
- Thesis
- Creator:
- Sheedy, Krysten Lynn
- Abstract:
- Glufosinate is the second most commonly used herbicide worldwide; it inhibits glutamine synthetase, which results in increased ammonia levels in plants and mammals. Due to their high polarity, low volatility, small size and lack of chromophores and fluorophores, glufosinate and its breakdown product 3-(methylphosphinico) propionic acid (3-MPPA) are difficult to detect at trace levels. Using the chemical derivatization strategy trimethylation enhancement using diazomethane (TrEnDi), glufosinate and 3-MPPA react with diazomethane and tetrafluoroboric acid to become permethylated, thus reducing their polarity and forming a fixed permanent positive charge on the amine group of glufosinate. When using reversed-phase high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), analyte retention and sensitivity are increased after derivatization, 6.7-fold for glufosinate and 6.3-fold for 3-MPPA. TrEnDi methodology was applied to canola samples from two separate fields sprayed with Liberty®. Prior to derivatization, the analysis showed no signal associated with unmodified glufosinate or 3- MPPA; however, TrEnDi modification resulted in quantifiable signals for both permethylated species.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Chemistry
- Date Created:
- 2023
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- Resource Type:
- Thesis
- Creator:
- Bernyk, Kimberly Ellen
- Abstract:
- Remotely piloted aircraft systems are a remote sensing platform for peatland researchers to monitor changes in vegetation height/composition/structure. In this work, an RPAS was flown to collect aerial images over Alfred Bog, a domed peatland complex located in Eastern Ontario. The images were processed with a photogrammetry technique called Structure-from-Motion, which can be used to create 3D point clouds of an x by y transect. The point cloud results were used to assess the utility of extracting ground terrain and vegetation height as compared to a transect field survey. This field survey was completed with a Trimble Catalyst RTK GNSS to record ground elevation and maximum vegetation height of the canopy top. The results from this research suggest that terrain information could not be extracted at all from the generated point clouds. Although, a digital surface model can be generated to model the canopy top and crown area.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Geography
- Date Created:
- 2023
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- Resource Type:
- Thesis
- Creator:
- Naranjo Vera, Mairelys
- Abstract:
- The wood frog, Rana sylvatica, is well known for its freeze tolerance ability. To endure winter, frozen frogs switch to a hypometabolic state via transcriptional regulation. Histone methylation is known to play a crucial role in regulating gene transcription. However, histone arginine methylation or demethylation has not previously been studied in the context of freeze tolerance. This thesis presents the first characterization of arginine methylation in a freeze tolerant vertebrate. Overall, levels of protein arginine methyltransferases (PRMTs) and methylated histone residues showed differential regulation over the freeze/thaw-cycle in wood frog liver. All PRMTs and downstream targets showed no changes during freezing, but protein levels of targets associated with transcription activation were elevated during thaw in skeletal muscle. Differential levels of histone demethylases were found in both tissues among the experimental conditions. These results indicate a role for histone methylation in supporting metabolic rate depression and tissue homeostasis during freezing.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Biology
- Date Created:
- 2022
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- Resource Type:
- Thesis
- Creator:
- Hapitas, Timothy Alexander
- Abstract:
- The gauged U(1)Lμ−Lτ extension of the Standard Model is a very simple framework that can alleviate the discrepancy in the anomalous magnetic dipole moment of the muon, reinforced by the recent Fermilab measurement. In this thesis, we introduce a dark matter (DM) candidate to the theory and proceed to study experimental probes of the model's parameter space with a general treatment of kinetic mixing between the Z′ gauge boson of the U(1)Lμ−Lτ symmetry and the Standard Model photon. The physical value of the total kinetic mixing depends on a free parameter of the model and the energy scale of a given process.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Physics
- Date Created:
- 2023
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- Resource Type:
- Thesis
- Creator:
- Chassin, Nicole Beatrice
- Abstract:
- In rings with a reasonable arrangement of left ideals, the finite-index left ideal structure can be partially captured by the Solomon zeta function. The integral quaternions are such a ring, and serve as a beneficial example. To find the zeta function of the integral quaternions, we first describe its local structure at each prime, and then the local structure of its finite-index left ideals. When doing this for odd primes, we make use of the p-adic integers.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Mathematics
- Date Created:
- 2023
-
- Resource Type:
- Thesis
- Creator:
- Zhou, Yuanxiang
- Abstract:
- Lie groups and Lie algebras are central objects in differential geometry and physics. Representing Lie groups and algebras as spaces of linear operators is one of the most powerful tools to understand their structures. In our thesis, we introduce the class of matrix Lie groups and algebras with focus on simply connected Lie groups and semisimple Lie algebras. To obtain the irreducible representation for semisimple Lie algebras, we construct the Verma module and obtain a finite-dimensional irreducible quotient space based on the Verma module. The Weyl's character formula, whose consequences include Weyl's dimension formula and Kostant's multiplicity formula, gives informative data to the irreducible representations. Lastly, nested special orthogonal algebras are investigated to obtain a generalization of Weyl's character formula together with a demonstrative application of Weyl's dimension formula and Kostant's multiplicity formula.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- FLAG
- Date Created:
- 2023
-
- Resource Type:
- Thesis
- Creator:
- Baril, Jimmy Milton
- Abstract:
- Hot electrons are generated from the decay of LSPR modes. Surface-enhanced Raman spectroscopy is used to monitor hot electron generation using a dehalogenation reaction. In this thesis, Ag, Au, and AuAg nanoparticle substrates were produced and coated with halogenated thiophenols. The dipole and coupled LSPR modes associated with the nanoparticle substrate both generate hot electrons under illumination. The hot electron yield was determined for each LSPR modes. It was found that the dipole LSPR mode produced a larger yield of hot electrons than the coupled LSPR mode. The enhanced hot electron yield for the dipole mode was reported for both Ag-slides and AuAg-slides; additionally, the same result was obtained for both halogenated thiophenols. This work shows that the dipole LSPR mode is more suitable for the generation of hot electron than the coupled mode. Additional work is required to make the coupled LSPR mode an efficient hot electron generator.
- Thesis Degree:
- Master of Science (M.Sc.)
- Thesis Degree Discipline:
- Chemistry
- Date Created:
- 2023