Enhanced methods for surface current estimation from X-band radar data

Estimating ocean surface currents accurately is crucial for a wide range of applications, including marine navigation, environmental monitoring, and coastal management. Traditional methods for measuring surface currents face challenges such as limited spatial coverage and sensitivity to environmental noise, making the development of more accurate and robust techniques a pressing need in oceanography. This thesis focuses on improving the accuracy and robustness of ocean surface current estimation using X-band radar image sequences by introducing two novel algorithms. In the first part of this thesis, a Symmetry of Doppler Shifts (SDS) method is introduced for retrieving surface current information from radar images. The method focuses on extracting the wave angular frequencies and corresponding wavenumbers from the radar image sequences. Then, Doppler shifts are calculated based on wavevectors that exhibit symmetry with respect to the origin in the wavenumber plane. These Doppler shifts are used to estimate both the speed and direction of surface currents. Simulations with synthetic data show that the SDS method achieves a root mean square error (RMSE) of 0.13 m/s for current speed and 1.4° for direction. The results indicate that the method performs with accuracy comparable to existing techniques under simulated conditions. The second part of this research builds on the SDS method by integrating it with an enhanced Polar Current Shell (PCS) algorithm. The improvements include the application of Kernel Density Estimation (KDE) for noise filtering, interquartile range filtering to remove outliers, and symmetry-based noise reduction. The modified PCS method also employs a single curve-fitting process, analyzing all wavenumbers in the PCS domain collectively rather than individually. The improved algorithm was validated with both simulated data and real-world radar data from a Decca radar (2008) and a Koden radar (2017). Results show that the modified PCS method reduces the RMSE for speed by 0.06 m/s and direction by 3.8° for the Decca radar, and by 0.02 m/s for speed and 4.6° for direction for the Koden radar, compared to the original PCS method

Structural characterization and tectonic evolution of 1.3 Ga REE-bearing Fox Harbour Volcanic Belt, southeast Labrador - Canada

The Southeastern Labrador region, Canada, preserves a complex geological history shaped by multiple deformation and metamorphic events. This study investigates the structural evolution, metamorphism, and deformation of the 1.3 Ga Fox Harbour Volcanic Belt (FHVB), a bimodal volcano-sedimentary sequence of peralkaline rhyolites enriched in rare earth elements (REE), mafic rocks, and sedimentary rocks deposited on 1.7-1.5 Ga basement rocks in an extensional setting along the Laurentian margin. Hosted in a highly strained amphibolite-facies corridor within the Lake Melville terrane (LMT), the FHVB domain is bordered by the Long Harbour (LHsz) and Fox Harbour (FHsz) shear zones to the south and north, respectively. Field observations, structural and petrographic analyses, along with U-Pb petrochronology on zircon, monazite, and titanite, reveal a multi-stage tectonic evolution. Deformation that accompanied the main phase of Grenvillian metamorphism (D1; ~1.06–1.04 Ga) locally involved amphibolite-facies metamorphism and anatexis, tight buckle folding, and tectonic burial of the LMT during Grenvillian convergence. The Pinware and Mealy Mountains terranes remained structurally higher in the tectonic pile and were shielded from significant metamorphism. Continued deformation (D2; ~1.04–1.02 Ga) was characterized by cooling, folding, and localized strain during a period of orogenic collapse, characterized by extensional adjustments of the orogenic crust. Late-stage transpressive deformation (D3; ~1.0 Ga) involved greenschist-facies oblique-slip and strike-slip shearing, overprinting earlier amphibolite-facies fabrics and facilitating the FHVB exhumation. These findings refine the tectonometamorphic history of the FHVB, providing new insights into the kinematic evolution of the Southeastern Grenville Province

The gut-brain connection: probiotic supplementation to alleviate cognitive decline and inflammation in rodent models of pretangle tau and stress

The microbiota-gut-brain axis is a crucial link to peripheral and central nervous systems, with gut health implicated in health and disease, including Alzheimer’s disease (AD) and stress. The objective of this dissertation is to explore the role of strengthening the gut microbiota in brain health and early-AD pathologies. First, I will investigate the effects of probiotic supplementation on cognitive function, brain inflammation, and gut microbiota composition. We employed a locus coeruleus hyperphosphorylated pretangle tau rat model, which closely resembles preclinical AD. Rats with pseudophosphorylated human tau in the LC showed deficits in spatial and olfactory learning, increased microglia and astrocyte activity, blood-brain barrier (BBB) leakage, and elevated peripheral inflammation. Probiotic supplementation increased gut microbiome diversity, optimized bacterial composition, and ameliorated cognitive deficits. A reduction in inflammation and glycogen synthase kinase 3 beta (GSK-3β) activity in the hippocampus of female rats was observed, suggesting gut health modulation as a potential therapeutic strategy in preclinical AD, and providing a possible mechanism underlying AD sex differences. Second, I examined the effects of probiotics prior to chronic stress or enrichment on cognitive function and brain health. Probiotics prevented stress-induced spatial memory impairments and enhanced learning under enrichment conditions. We propose this is linked to increased gut microbiome diversity and eubiosis, which was observed in our animals. Probiotics prevented increased levels of the microglia marker ionized calcium-binding adaptor molecule 1 (Iba-1) found in stressed rats and showed differences in BBB integrity and tyrosine hydroxylase (TH) levels in the hippocampus between stress and enrichment groups, with beneficial effects observed in enriched animals. These findings highlight the potential of probiotics to enhance cognitive function and brain health through modulation of the gut microbiota, offering a non-invasive therapeutic approach for AD and stress-related cognitive decline

Investigation of a potential interaction between PKD3 and MP-GAP utilizing fluorescent microscopy and FRET

Failures in cytokinesis, the final stage of mitosis, can lead to binucleation, which may act as an initiation point for cancer development. Protein kinase D3 (PKD3) is an enzyme that belongs to a family of protein kinases that have key roles in promoting many cellular processes, including proliferation, survival, and adhesion. It has been demonstrated that PKD3 depletion can cause a significant increase in binucleation in mouse embryonic fibroblasts (MEFs). In addition, the M�Phase GTPase-Activating Protein (MP-GAP) is shown to play an important role during the abscission of two daughter cells by inactivating the Ras homolog gene family member A (RhoA). The Leitges group previously showed that MP-GAP is translocated to the cleavage furrow at the late cytokinesis, where it colocalizes with RhoA and PKD3. Considering the effect of PKD3 deficiency on cells and the role of MP-GAP in cytokinesis, we aimed to verify the hypothesis that these two proteins might interact to regulate the final abscission. In this regard, this project was based on fluorescent microscopy imaging to track the dynamics of fluorescent protein-fused PKD3 and MP-GAP to characterize a potential interaction. In conclusion, while some data were collected on the endogenous PKD localization in cells, more experiments are required to establish a definitive strategy to identify a potential interaction

Effect of crude oil on defence-relevant biomarker gene expression in early-life stage lumpfish

This thesis investigated the response of early-life stage lumpfish (i.e., larval and juvenile) to crude oil at the mRNA level. A pilot study was conducted on juvenile lumpfish, which were exposed to five chemically-enhanced water-accommodated fraction (CEWAF) treatments for 24 h in a static system. Through multiple sequence alignment (MSA), phylogenetic and synteny analyses, five lumpfish aryl hydrocarbon receptor genes were studied and named following those in Japanese pufferfish (Takifugu rubripes). The results of real-time quantitative polymerase chain reaction (qPCR) showed significant induction for ahr1a, ahr2a and cyp1a1 in the liver of oil-exposed juvenile lumpfish. Based on these results, another exposure experiment was done on 50 days post-hatch lumpfish larvae in a similar exposure set-up, with two additional CEWAF treatments. The qPCR results indicated that the 24-h CEWAF exposure might modulate immune and redox function in larval lumpfish. Moreover, a Spearman correlation analysis and principal component analysis suggested that Ahr may affect the expression of genes involved in cardiovascular development and immune response. Collectively, these results provide new insight into the influence of acute crude oil exposure on the transcript levels of targeted genes in larval and juvenile lumpfish

Approaches to establishing meaningful partnerships with Indigenous groups: an examination of protocol from eight museums

Museums are often regarded as respected places of learning; however, they have played a significant role creating and disseminating stereotypes about Indigenous People by misrepresenting them and their cultures. This, coupled with the often violent way that material culture has been collected, has left museums with legacies that can be harmful and unwelcoming to Indigenous Peoples. Indigenous activism both within and outside heritage spheres has led to documents such as UNDRIP, which affirm Indigenous sovereignties and rights to their culture and heritage, and have set a new precedent for how museums should operate and represent Indigenous cultures. This thesis examines eight museums from across Canada, the USA, and Germany to understand how they are engaging with the Indigenous Nations they represent, and further, how they are counteracting their legacies. This is coupled with the observation of the first stage of Creating Context, a community-project that brought Nunatsiavummiut to Germany to reconnect with material culture in two museum’s care. It was found that the establishment of meaningful relationships is based in trust, and brought to action with three guiding principles (1) ontological empathy; (2) power-shifting and (3) culturally specific care protocol. These themes are foundational in guiding museums toward a better museum practice

An investigation of instructional rounds and novice teacher self-efficacy: an evaluative case study

The purpose of this qualitative study, situated at an independent Vancouver school, was to investigate the use of instructional rounds as a collaborative professional learning tool in promoting novice teacher self-efficacy. The study utilized an evaluative case study approach to explore the experiences of four novice teachers as they engaged in several rounds of classroom observation, group debrief, and self-reflection. Data were collected using semi-structured interviews, document reviews, and research field notes. Findings from the research suggest that instructional rounds provide an effective vehicle for professional learning and for building educators’ self-efficacy beliefs. Participants attributed heightened impressions of self-efficacy to several elements of the instructional rounds process, including (1) creating a shared vision and goals, (2) engaging in non-evaluative classroom observations, (3) collaborating in a safe and supportive learning environment, and (4) critically reflecting on their own teaching practices. The study provides useful insight for administrators and policy makers as they plan high-quality professional learning aimed toward continuous school improvement. It also underscores the complexity of implementing robust professional learning initiatives that are designed to foster greater teacher professionalism. Suggestions are made to help schools renew their focus on professionalism and teacher self-efficacy, which may help retain a growing number of early career teachers who choose to leave the profession. Recommendations are also made for further research

Electric load forecasting using deep neural networks

Short-Term Load Forecasting (STLF) is a critical and complex task that plays a vital role in the efficient management of electricity generation, transmission, and distribution. Recent research has made strides in this field through the application of advanced deep learning techniques to enhance the accuracy and reliability of load predictions. The first study introduces a novel deep neural network tailored for STLF at Memorial University of Newfoundland (MUN). This model integrates electric load data with meteorological information and features a 1D Convolutional Neural Network followed by an Encoder-Decoder Network with an attention mechanism, showing superior performance compared to traditional Gated Recurrent Unit (GRU) and Long Short Term Memory (LSTM) models. The study also focuses on optimizing the input horizon using the algorithm. The second study focuses on Multi-Energy Systems (MES) and presents a Multi-Task Learning-based approach for load forecasting. It features a cutting-edge deep learning architecture designed to forecast multiple loads simultaneously. Applied to the University of Austin Tempe Campus, this approach employs a Deep Temporal Convolutional Neural Network (D-TCNet) to effectively capture spatial and temporal correlations in the data, resulting in improved forecasting accuracy across different energy types and seasons. The third study compares various Recurrent Neural Network (RNN)-based time-series forecasting algorithms, including LSTM, GRU, Bi-directional GRU, and Bi-directional LSTM, on electric load data from MUN. The Bi-directional GRU model emerged as the top performer, achieving the highest R2 score and the lowest Mean Squared Error (MSE) and Mean Absolute Error (MAE) for day-ahead predictions. Collectively, these studies demonstrate the power of deep learning in enhancing the precision and effectiveness of short-term load forecasting, offering promising avenues for optimizing energy system operations

On the rocks: recruitment and distribution patterns on deep-sea hard substrata in the Labrador Sea and Baffin Bay (Canada)

The study of larval recruitment and colonization patterns in hard-bottom benthic communities is crucial to the understanding of species distributions, community assembly, and the potential effects of anthropogenic activity and climate change on the maintenance of biodiversity. Expanding our knowledge of early and established communities is an important first step. To explore this need, I first examined recruitment patterns on four substratum types (mesh, plastic, stone, wood) deployed for ~1 y at four sites in bathyal Labrador Sea (Canada). I determined that colonial hydrozoan recruits dominated all substratum types and sites; arthropods, octocorals, and other anthozoans were sparser. The features of each substratum type facilitated differential recruitment patterns: the complex, three-dimensional structure of mesh had higher morphospecies richness and diversity, while the sheltered, larger surface area of plastic had higher abundance and density by recruits. Wood, as a single elongated panel, had the most surface and canopy coverage. Secondly, I examined regional diversity and zonation patterns of morphospecies colonizing terrigenous ice-rafted dropstones at bathyal depths in the Labrador Sea (LAB) and Baffin Bay (BAF). Based on in-situ images, dropstones exhibited more epibenthic megafaunal richness than surrounding finer-grained substrata and, following analysis of collected dropstones, a total of 101 taxa spanning 10 phyla were recorded with bryozoans dominating numerically at all depths. The richness of dropstone communities was higher in LAB than BAF overall, though 19 morphospecies spanned both locations. Zonation patterns were consistent, with a majority of morphospecies positioned above the stone-sediment boundary or at the boundary, and one morphospecies of polychaete below. Ecological interactions appeared to influence both positioning and regional distributions. By combining early and established community studies, my thesis provides data on how deep-sea hard-bottom epibenthic assemblages form and develop

Technology use in counselling education: Canadian counselling and psychology educators' perceptions

The study explored counsellor and psychologist educators’ perceptions of the use of technology for graduate-level counsellor education. Understanding how COVID-19 shifted participants’ approaches to teaching was part of the rationale for studying online education in this context. The study further explored educators’ perceptions of different delivery formats for counsellor and psychologist education. The aim was achieved by using a survey-based design focused on Canadian counsellor and psychologist educators who have taught both pre-pandemic and during the pandemic and who have taught at least one online and at least one face-to-face course in counselling, school psychology, or clinical psychology over the past five years. The data were collected using an online survey administered through Qualtrics. The results of the study showed that (a) educators were challenged in supporting quality practicum and internship experiences in online modality and identified it as not suitable for online delivery, (b) educators found it difficult to establish connections with their students and ensure students’ competence while teaching online (c) educators structured their courses using synchronous video (d) benefits of online counsellor education were associated with flexibility, travel time and cost savings, equity, and convenience (e) concerns with online teaching were difficulty with building strong foundational competencies for students, engagement in professional discussion, distractions, lack of connection with students and less interactivity. Important findings are discussed in relation to other scholarly research. In addition, implications for training and future research are discussed