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Balance is key: Perceptual fluency as a link between trait incompleteness and symmetry preferences
While preferences for symmetry are seemingly universal, they can be seen at their most extreme among individuals high in trait incompleteness. As yet, it is unclear why incompleteness yields heightened symmetry preferences. Summerfeldt et al. (2015) speculated that individuals high in incompleteness may develop heightened preferences for symmetry due to its greater perceptual fluency. Accordingly, the aim of the present set of three experiments was to examine this relationship. Implicit preferences for symmetry were measured using a modified version of the Implicit Association Test (IAT) reported by Makin et al. (2012). Experiments 1 (N = 24) and 2 (N = 24) examined whether the general implicit preferences for symmetry and influence of perceptual fluency reported by Makin et al. (2012) extended to a within-subjects design. Experiment 3 (N = 86) examined whether trait incompleteness is related to greater implicit preferences for symmetric stimuli, and whether perceptual fluency affects this association. Results showed that incompleteness and implicit preferences were related, and that incompleteness-related differences in preferences were eliminated when the patterns were equally perceptually fluent, supporting the idea that incompleteness-related preferences for symmetry are linked to perceptual fluency. Implications of these findings are discussed.
Genomic architecture of artificially and sexually selected traits in white-tailed deer (Odocoileus virginianus)
Understanding the complex genomic architecture underlying quantitative traits can provide valuable insight for the conservation and management of wildlife. Despite improvements in sequencing technologies, few empirical studies have identified quantitative trait loci (QTL) via whole genome sequencing in free-ranging mammal populations outside a few well-studied systems. This thesis uses high-depth whole genome pooled re-sequencing to characterize the molecular basis of the natural variation observed in two sexually selected, heritable traits in white-tailed deer (Odocoileus virginianus, WTD). Specifically, sampled individuals representing the phenotypic extremes from an island population of WTD for antler and body size traits. Our results showed a largely homogenous genome between extreme phenotypes for each trait, with many highly differentiated regions throughout the genome, indicative of a quantitative model for polygenic traits. We identified and validated several potential QTL of putatively small-to-moderate effect for each trait, and discuss the potential for real-world application to conservation and management.
Author Keywords: evolution, extreme phenotypes, genetics, genomics, quantitative traits, sexual selection
Soil Geochemistry and Normative Mineralogy across Canada
Soils play a crucial role in ecosystem functioning, for example, soil minerals provide important provisioning and regulate ecosystem services. This study used major soil oxides from the North American Soil Geochemical Landscapes Project (n=560) to assess elemental associations and infer soil minerals through exploratory data analysis and to determined quantitative soil mineralogy using a normative method, Analysis to Mineralogy (n=1170). Results showed elemental variability of oxides across the provinces of Canada and strong correlations occurred between elements indicative of soil mineral composition (e.g., Silicon and Aluminium). Principal component analysis inferred soil minerals from soil oxides trends on biplots and classified minerals, generally, as carbonates, silicates, and weathered secondary oxides. Spatial variability in minerals (quartz, plagioclase, potassium feldspar, chlorite, and muscovite) was related to the underlying bedrock geology. The use of Analysis to Mineralogy led to a reliable method of quantifying soil minerals at a large scale.
Author Keywords: Analysis to Mineralogy, Exploratory data analysis, Normative procedures, North American Soil Geochemical Landscapes Project, Soil geochemistry, Soil mineralogy
A Cluster Approach Applied to the One-Dimensional Anderson-Hubbard Model
S. Johri and R. Bhatt developed a real-space renormalization group approach aimed at extracting the localized single-particle eigenstates of the Anderson model from a large system by identifying clusters of resonant site potentials. E. Campbell generalized this real-space renormalization group approach using standard perturbation theory. Both approaches were intended to approximate the single-particle density of states of the Anderson model. In this thesis, we aimed to test the potential of applying a similar real-space renormalization group approach to calculate the density of states of the interacting Anderson-Hubbard model. Our interest in the density of states of this model is due to a V-shaped zero-bias anomaly in two-dimensional systems. A real-space renormalization group approach is best applied to a one-dimensional system. We found that the zero-bias anomaly is not V-shaped in one-dimension. To test the potential of a real-space renormalization group approach, we used the cluster approach which is the same as the non-interacting renormalization group approach but without the perturbation theory and found that for strong disorder this technique could accurately calculate the density of states over a wide range of energies but deviated from exact results at the band edge, at $\omega=\pm U$ and near $\omega=0$. The first two inaccuracies will be reduced with a proper real-space renormalization group approach. We suspect that the last inaccuracy is associated with long range physics and may be difficult to recover. We also developed a technique that adjusts the identification of clusters in the cluster approach to improve the computation time of the density of states with minimal loss of accuracy in a tunable range around the Fermi level. We found that this technique significantly reduced the computation time and was able to preserve the density of states near the Fermi level, except at the smallest energies near $\omega=0$.
Author Keywords: Anderson-Hubbard model, renormalization group, Strong electron correlations, Zero-bias anomaly
A Question of Space: Insights into the Function of Chultunes in the Maya Southern Lowlands
Chultuns are subterranean chambers that are found throughout the Maya area. The purpose of this thesis is to provide further insight into the function of chultuns, specifically within the area of the Southern Maya Lowlands. Within the Northern Lowlands, the Pre-Columbian Maya used chultuns for water storage, but this function does not appear to be as prevalent within the Southern Lowlands Through reviewing published literature and first-hand excavation, a total of 332 chultuns located with the specified area were catalogued into a database. Based on the information obtained from the research, this thesis has identified the most frequent final function of chultuns, if there is chronological change in final functions of chultuns, and if there is regional change in final functions of chultuns.
Author Keywords: burial, chultuns, Maya, ritual, Southern Lowlands, storage
Detectability and its role in understanding upland sandpiper (Bartramia longicauda) occurence in the fragmented landscape of southern Ontario
Upland Sandpipers (Bartramia longicauda), like many grassland birds, are undergoing population decline in parts of their range. Habitat fragmentation and change have been hypothesized as potential causes of decline. I used citizen-science occurrence data from Wildlife Preservation Canada's Adopt-A-Shrike Loggerhead Shrike (Lanius ludovicianus) program in conjunction with validation surveys, using similar point-count methods, to examine detectability and determine if landscape level habitat features could predict occupancy of Upland Sandpipers in Southern Ontario. In a single season detectability study, I used Wildlife Preservation Canada's survey protocol to determine detectability in sites that were known to be occupied. Detectability was low, with six surveys necessary to ensure detection using a duration of at least 18 minutes early in the breeding season. The proportion of open habitat did not affect detection on the landscape. Using a larger spatial and temporal scale, with five years of citizen-science data, I showed that Annual Crop Inventory data could not effectively predict Upland Sandpiper occupancy. Model uncertainty could be attributed to survey protocol and life history traits of the Upland Sandpiper, suggesting that appropriate survey methods be derived a priori for maximizing the potential of citizen-science data for robust analyses.
Author Keywords: Bartramia longicauda, citizen-science, detection, landscape, occupancy, Ontario
Modelling the Lanthanum Aluminate-Strontium Titanate Interface with a Modified Transverse Ising Model
In 2004 it was discovered that a two-dimensional electron gas (2DEG) forms at the interface between lanthanum aluminate (LAO) and strontium titanate (STO). This 2DEG exhibits a variety of electronic and magnetic phenomena, motivating intense research into its applicability to electronic devices. Over the years several models have been developed in theoretical exploration of this system. Here, the transverse Ising model is applied to the LAO/STO interface for the first time. It is shown that the model as it is traditionally formulated cannot accurately predict the structure of the electron density at the interface. I show that this can be fixed with a simple modification of the model, and discuss how this modification affects both the polarization distribution in ferroelectric thin films and the electron density at the LAO/STO interface. The importance of including the depolarizing field when modelling spatially inhomogeneous ferroelectric systems is also explored.
Author Keywords: ferroelectric thin film, lanthanum aluminate, strontium titanate, transverse Ising model, two-dimensional electron gas
Exploring Kiki-Inoomgugaewin: Anishnaabeg Youth Multilingualism & Technology~ A Participatory Narrative Inquiry
This case study contributes to scholarship surrounding the national conversation on Indigenous language sustainability in North America. Much of this scholarship provides insight on structuring language programs and policies for youth, leaving a tremendous research gap regarding sociolinguistic and cultural research with youth. Youth appear disinterested or otherwise set apart in current research from the development of policies and curriculum concerned with heritage languages. Upon closer inspection; however, youth are engaged and using innovative and different tools than previous generations. This exploration is a foundational case study which builds upon research highlighting the nature of Indigenous language loss in the south as a time sensitive phenomenon as the application of cognitive imperialism and colonial tactics within mainstream schools continue to conceal a large scale cultural and linguistic genocide in Canada.
Although Indigenous language loss may seem of concern to only small groups of linguists and dialectic communities, it should in fact concern anyone who cares about reconciliation or closing the tremendous gap in accessing equitable education. The preservation of Indigenous languages and knowledge systems should also be of interest to those parties who seek to comprehensively understand the Natural World and whom have a vested interest in the survival of the planet and protection of the enviroment. Because of these realities, the viewpoints and experiences of all concerned parties are essential. It follows then, that the youth perspective is significant.
To address this gap, participatory narrative inquiry was used as a theoretical framework to conduct a foundational case study in which detailed consideration was given to exploring the lived narratives of three Anishnaabeg participants to establish the value of Indigenous youth voice in alternative forms of sociolinguistic and culturally sustainable language learning in the 21st century, and, to strengthen the argument that more research is needed in the field of first-person youth studies.
The results of this case study will be useful, specifically, to localized communities of Anishnaabe youth with and for whom much of the research was conducted, and, more generally to youth resistance work focused on media and technology in globalized and contemporary language and cultural ecologies. Research outcomes indicated potential directions for future research in different contexts and localities by presenting commonalities within the fields of social and political engagement and their connection to language and new media in youth populations. It is hoped that this initial material pinpointing a research gap in Indigenous youth language studies will be used to investigate future research in this field.
Author Keywords: Anishnaabe, Decolonization, Language, Sociolinguistics, Technology, Youth Studies
The Effect of Nitrosative Stress on Heme Protein Expression and Localization in Giardia Intestinalis
The parasitic protist Giardia intestinalis has five heme proteins: a flavohemoglobin and several isotypes of cytochrome b5. While the flavohemoglobin has a role in counteracting nitric oxide, the functions of the cytochromes (gCYTb5s) are unknown. In this study, the protein level and cellular localization of three gCYTB5 isotypes (gCYTb5-I, II and III) and flavohemoglobin were examined in Giardia trophozoites exposed to three nitrosative stressors at two different concentrations: nitrite (20 mM, 0.5 mM); GSNO (2 mM, 0.25 mM) and DETA-NONOate (2 mM, 0.05 mM). An increase in protein levels was observed for gCYTb5-II with all stressors at both concentrations. However, the effects of these nitrosative stressors on gCYTb5-I and III were inconclusive due to the variation among the replicates and the poor detection of gCYTb5- III on western blots. The protein level of the flavohemoglobin also increased in response to the three stressors at the low concentrations of stressors that were tested. Only the cellular localization of gCYTb5-I changed in response to nitrosative stress, where it moved from the nucleolus to the nucleus and cytoplasm. This response was extremely sensitive and occurred at the lower doses of the three stressors, suggesting that gCYTb5-I may be involved in a nucleolar- based stress response.