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Thawing permafrost due to increasingly warm temperatures in northern subarctic regions is releasing mercury. The consequent formation of thaw ponds in the peatland palsa valley of the Sasapimakwananisikw (SAS) river in Whapmagoostui-Kuujjuarapik, Québec may provide a pool for MMHg formation and a potential risk to aquatic and human life, if these ponds facilitate MMHg export through hydrological connections to nearby waterways. Hg methylation and MMHg demethylation activities were examined in thaw pond sediments using a Hg tracer isotope incubation experiment. Analysis by coupling gas chromatography cold-vapor atomic fluorescence spectrophotometry (GC-CVAFS) with inductively coupled mass spectrometry (ICP-MS) techniques showed that MMHg was produced at a higher rate and within the first 2 h of incubation for both summer and winter seasons. For thaw ponds SAS1A, SAS1B and SAS2A, MMHg was formed at 0.0048 % h-1, 0.0012 % h-1, and 0.0008 % h-1, respectively during winter and at 0.0001 % h-1, 0.0016 % h-1, and 0.0010 % h-1, respectively during summer. Detection of MMHg losses were not as expected likely due to limitations of the combined tracer spike and overestimation of the in situ ambient mercury levels. Physical and chemical properties vary within ponds, among ponds and between winter and summer. SAS1B's location nearby an organic carbon rich palsa may be ideal to study DOC – Hg interactions. Variability in pond characteristics including depth, surface area, age, pH, temperature, colour, oxygen concentration, total dissolved and suspended solids, conductivity, carbon, mercury, ammonium, calcium, magnesium, sulfate, total phosphorous, potassium, and sodium between seasons indicate the challenge of predicting future environmental impacts of climate change related thaw pond creation in the north.

Author Keywords: demethylation, mercury, methylation, methylmercury, SAS, thaw ponds

The purpose of this research is to apply four methods on two data sets, a Synthetic

dataset and a Real-World dataset, and compare the results to each other with the

intention of arriving at methods to prevent fraud. Methods used include Logistic Regression,

Isolation Forest, Ensemble Method and Generative Adversarial Networks.

Results show that all four models achieve accuracies between 91% and 99% except

Isolation Forest gave 69% accuracy for the Synthetic dataset.

The four models detect fraud well when built on a training set and tested with

a test set. Logistic Regression achieves good results with less computational eorts.

Isolation Forest achieve lower results accuracies when the data is sparse and not preprocessed

correctly. Ensemble Models achieve the highest accuracy for both datasets.

GAN achieves good results but overts if a big number of epochs was used. Future

work could incorporate other classiers.

Author Keywords: Ensemble Method, GAN, Isolation forest, Logistic Regression, Outliers

This thesis investigated the role of the neuronal ceroid lipofuscinosis protein, Cln5, during autophagy. This was accomplished by performing well-established assays in a Dictyostelium cln5 knockout model (cln5-). In this study, cln5- cells displayed a reduced maximum cell density during growth and impaired cell proliferation in autophagy-stimulating media. cln5- cells had an increased number of autophagic puncta (autophagosomes and lysosomes), suggesting that autophagy is induced when cln5 is absent. cln5- cells displayed increased amounts of ubiquitin-positive proteins but had no change in proteasome protein abundance. During the development of cln5- cells, fruiting bodies developed precociously and cln5- slug size was reduced. Lastly, when cln5- cells were developed on water agar containing ammonium chloride (NH4Cl), a lysosomotropic agent, the formation of multicellular structures was impaired, and the small slug phenotype was exaggerated. In summary, these results indicate that Cln5 plays a role in autophagy in Dictyostelium. The cellular processes that regulate autophagy in Dictyostelium are similar to those that regulate the process in mammalian cells. Thus, this research provides insight into the undefined pathological mechanism of CLN5 disease and could identify cellular pathways for targeted therapeutics.

Author Keywords: Autophagy, Batten disease, Cln5, Dictyostelium discoideum, NCL

Understanding breeding and migration habits of Whimbrel (Numenius phaeopus) in the Hudson Bay Lowlands is important for the conservation of this population. I monitored Whimbrel at two breeding sites: the Churchill region of Manitoba and Burntpoint, Ontario. Annual average nest initiation timing was highly variable and successful nests were initiated significantly earlier than those that failed. Although nests were initiated significantly earlier at Burntpoint than Churchill, annual nest success quantified in program R MARK was similar across sites. Observed nest success rates were lower than historical records and most failure was due to predation. Annual nest survival varied widely and I used a generalized linear model to relate annual nest survival to annual average weather conditions. I observed weak relationships between annual nest survival and weather conditions in the northbound staging grounds. I tracked post-breeding migratory movements using the MOTUS radio telemetry system and observed consistent use of the mid-Atlantic coast of the United States during migration, especially among birds emerging from Churchill. In Burntpoint, I observed more variability in post-breeding migratory trajectories and significantly earlier post-breeding departure as compared to Churchill. The results of my study suggest differences in breeding and migration habits exist across nearby breeding populations, indicating that there is a need for population-specific conservation approaches for this declining species.

Author Keywords: Migration, Movement Ecology, Nesting Ecology, Nest Success, Shorebird conservation, Whimbrel

Many shorebirds rely on small numbers of staging sites during long annual migrations. Numerous species are declining and understanding the importance of staging sites is critical to successful conservation. We surveyed endangered rufa Red Knots staging in James Bay, Ontario during southbound migration from 2009 to 2018. We used an integrated population model to estimate passage population size in 2017 and 2018 and found that up to 27% of the total rufa population staged in James Bay. We also extended the model to incorporate age composition of the passage population. In future applications, this method could improve our understanding of the role of breeding success in population declines. We then estimated annual apparent survival from 2009 to 2018. Survival remained near constant, though lower than estimated elsewhere in the Red Knot range, which may reflect higher permanent emigration rates rather than truly lower survival. This work demonstrates that this northern region is a key staging site for endangered Red Knots and should be included in conservation planning.

Author Keywords: integrated population model, mark-recapture, migratory stopover, shorebirds, species at risk, survival

Little thought is given to how equitable mathematics would better the lives of those marginalized, or how the increased inclusion of marginalized voices improves the practice of mathematics. The purpose of this narrative research is to explore students' voices and analyze aspects of math identity: the reported beliefs and practices of a group of elementary urban students who identify as Black/Brown.

Understanding voice through counter-narrative is a methodology for the equitable practice of teaching/learning mathematics. CRRP describes participants engaged in the metacognitive task of writing untold stories as it relates to their beliefs, practices, and experiences in mathematics learning. The findings offer meaningful and appropriate insights to math educators about student competency, belongingness, and agency.

Keywords: Black and Brown, marginalized students, student engagement, math identity, mathematical competence, sense of belonging to mathematics, mathematical agency, gateway, gatekeeper, fixed mindset, growth mindset, STEM pipeline, counter narrative.

Author Keywords: Black and Brown, marginalized students, mathematical competence, math identity, sense of belonging to mathematics, student engagement

Energy storage efficiency and sustainability require advanced technologies and novel materials. Recently, bio-based phase change materials (PCMs) have received significant attention for thermal energy storage (TES) uses. Vegetable oils are versatile renewable feedstocks that are well suited for the development of sustainable, functional PCMs. PCMs derived from vegetable oil, which compares favorably with paraffin waxes, the industry standard, are currently available. However, their melting points are typically below 80 °C preventing their wider integration in TES applications, particularly those requiring higher temperatures. The present work manipulated the structural building blocks of fatty acids to advantageously affect the intermolecular forces and increase the properties relevant to TES. The polar amide functional group was incorporated into fatty moieties to take advantage of the strong hydrogen bonds that it forms to increase intermolecular attractions and hence increase the phase change temperature and enthalpy as well as to improve thermal stability and thermal conductivity. A series of carefully designed lipid-derived monoamides and four series of lipid-derived diamides were synthesized via benign and simple amidation reactions. The purity of the amides and the intermolecular hydrogen bond strength were assessed using 1H NMR and FTIR. The properties relevant to TES such as thermal transition, crystal structure and polymorphism, thermal stability and thermal conductivity were measured using DSC, XRD, TGA and a thermal conductivity analyzer, respectively. The complex roles of the PCM's constituting molecular building blocks in the phase behavior were elucidated and correlations between structure, processing conditions and macroscopic physicochemical properties, never before elucidated, were assembled in predictive relationships, drawing a unified picture of the rules that generally govern the phase behavior of lipid-derived PCMs. Practically, the prepared amides demonstrated desirable TES properties with substantial performance improvement over current bio-based PCMs. They presented increased phase change temperatures (79 - 159 °C), enthalpies of fusion (155 - 220 J/g) and thermal stability (234 - 353 °C). More importantly, the predictive structure-function relationships established in this work will allow the straightforward engineering of lipid-derived amide PCM architectures with judicious selection of molecular building blocks to extend the range of organic PCMs and deliver thermal properties desirable for TES applications.

Author Keywords: LATENT HEAT THERMAL ENERGY STORAGE, LIPID-DERIVED AMIDES, PHASE CHANGE MATERIALS, RENEWABLE, SOLID LIQUID AMIDE PCMS, THERMAL PROPERTIES

Ill-structured problems have changing components that solvers need to adapt their solutions to. Well-structured problems have strict, well-defined procedures, and solvers must know which procedures to apply and when. Research has suggested that these two types of problems utilize different problem-solving skills. The current study focused on the relation between ill-structured interpersonal problem solving, novel well-structured problem-solving, and cognitive flexibility in young adults and older adolescents. It was predicted that because of the changing components of ill-structured problems, cognitive flexibility would more strongly predict these compared to well-structured problems. The current study sample consisted of 73 undergraduates with an average age of 20.43 years. The results showed that cognitive flexibility is equally associated with ill-structured problem-solving and well-structured problem-solving. This suggests that cognitive flexibility may support the perspective coordination involved in solving ill-structured problems and that cognitive flexibility may support switching between search strategies when solving a novel well-structured problem.

Author Keywords: adolescent, adult, cognitive flexibility, ill-structured problem-solving, novel problems, well-structured problem-solving

In the Wabigoon/English River system, mercury concentrations downstream from Dryden, ON, where there was a former chlor-alkali plant, remain elevated in sediments and biota. Understanding the current extent and severity of mercury contamination downstream from the former chlor-alkali plant is of great interest in furthering the clean-up of mercury within the traditional territory of Asubpeeschoseewagong Netum (Grassy Narrows) First Nation. The objective of this study was to evaluate the current level and extent of mercury contamination within sediments, crayfish, Hexagenia mayflies, yellow perch, spottail shiner and walleye in the Wabigoon/English River system. An additional objective was to use mercury stable isotope analysis to distinguish between legacy mercury from the former chlor-alkali plant and mercury from geogenic sources. Mercury contamination within surface sediments and biota at locations as far as 178 kms downstream of the historical source of mercury contamination are elevated relative to the reference lake, Wabigoon Lake. Isotope ratios in young of the year fish and sediments collected from within the system were distinct from fish from the reference lake, Wabigoon Lake, indicating that anthropogenic mercury contamination is distinguishable from geogenic mercury.

My analysis of twentieth century Mars science and fiction outlines how the ongoing dialogic between Mars science and fiction publics influences the American frontier dialectic and how Mars serves as the arena where this debate comes to life. It examines connections between myth, science, and fiction by tracing the evolution of historical and literary representations of the American frontier and understandings of Mars spanning the twentieth century. To illustrate these findings, I investigate the fictional visions of the planet in the works of Edgar Rice Burroughs, Ray Bradbury, and Kim Stanley Robinson. Ultimately, Mars is revealed as a fictional frontier where a better way of living may be achievable by transforming the planet and ourselves. Finally, the planet's physical site holds a haunting potential value that inspires further research and new narratives, which informs the future use of Mars in American culture.

Author Keywords: Bradbury, Burroughs, Frontier, Mars, Myth, Robinson