Electronic Thesis or Dissertation

Detectability and its role in understanding upland sandpiper (Bartramia longicauda) occurence in the fragmented landscape of southern Ontario

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Creator (cre): Chronowic, Daniel Adam, Thesis advisor (ths): Nol, Erica, Degree committee member (dgc): Bowman, Jeff, Degree committee member (dgc): Nocera, Joe, Degree granting institution (dgg): Trent University
Abstract:

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

2019

Modelling the Lanthanum Aluminate-Strontium Titanate Interface with a Modified Transverse Ising Model

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Creator (cre): Chapman, Kelsey Sarah, Thesis advisor (ths): Atkinson, William A, Degree committee member (dgc): Wortis, Rachel, Degree committee member (dgc): de Haan, Hendrick, Degree granting institution (dgg): Trent University
Abstract:

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

2019

Exploring Kiki-Inoomgugaewin: Anishnaabeg Youth Multilingualism & Technology~ A Participatory Narrative Inquiry

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Creator (cre): Cunningham, Samantha Holly, Thesis advisor (ths): Sherman, Paula, Degree committee member (dgc): Newhouse, David, Degree granting institution (dgg): Trent University
Abstract:

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

2019

The Effect of Nitrosative Stress on Heme Protein Expression and Localization in Giardia Intestinalis

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Creator (cre): Sajer, Bayan, Thesis advisor (ths): Yee, Janet, Degree committee member (dgc): Rafferty, Steven, Degree committee member (dgc): Bates, Holly, Degree committee member (dgc): Brunetti, Craig, Degree granting institution (dgg): Trent University
Abstract:

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.

2019

Transform Techniques in Electrochemistry

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Creator (cre): Hempstead, Michael Roy, Degree granting institution (dgg): Trent University
Abstract:
1983

Support Vector Machines for Automated Galaxy Classification

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Creator (cre): Chambers, Cameron Darrin, Thesis advisor (ths): McConnell, Sabine, Thesis advisor (ths): Hurley, Richard, Degree granting institution (dgg): Trent University
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Support Vector Machines (SVMs) are a deterministic, supervised machine learning algorithm that have been successfully applied to many areas of research. They are heavily grounded in mathematical theory and are effective at processing high-dimensional data. This thesis models a variety of galaxy classification tasks using SVMs and data from the Galaxy Zoo 2 project. SVM parameters were tuned in parallel using resources from Compute Canada, and a total of four experiments were completed to determine if invariance training and ensembles can be utilized to improve classification performance. It was found that SVMs performed well at many of the galaxy classification tasks examined, and the additional techniques explored did not provide a considerable improvement.

Author Keywords: Compute Canada, Kernel, SDSS, SHARCNET, Support Vector Machine, SVM

2019

Making eDNA count: Using environmental DNA (eDNA) to quantify relative larval amphibian abundance

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Creator (cre): Breton, Brie-Anne, Thesis advisor (ths): Murray, Dennis, Degree committee member (dgc): Wilson, Chris, Degree committee member (dgc): Lesbarrères, David, Degree granting institution (dgg): Trent University
Abstract:

Environmental DNA (eDNA) is rapidly becoming an established method for the detection of species in aquatic systems and has been suggested as a promising tool to estimate species abundance. However, the strength of the relationship between eDNA concentrations and taxon abundance (density/biomass) can vary widely between species. I investigated the relationship between eDNA concentration and species abundance using two common and closely-related amphibians in eastern North America, the wood frog (Rana sylvatica) and northern leopard frog (Rana pipiens). I manipulated tadpole density in 80 L mesocosms and documented the relationship between tadpole density, biomass, and eDNA concentration. Species were comparable in biomass but differed in the amount of detectible genetic material produced; density and biomass were the superior abundance metric correlated with eDNA concentration for wood frogs and leopard frogs, respectively. However, increases in eDNA concentration reflected increasing tadpole biomass, therefore biomass is likely a better metric of abundance than density. Overall my findings support that eDNA concentration can be used as an index of species abundance, but that species-specific calibration may be needed before eDNA concentration can be effectively translated to an abundance metric. Future research should refine our understanding of how biotic and abiotic factors influence eDNA production, degradation, and recovery across species, before the method can receive widespread use as a monitoring tool in natural settings.

Author Keywords: abundance estimates, environmental DNA, mesocosm, Rana pipiens, Rana sylvatica

2019

Observation-based assessment of atmospheric sulphur surrounding a major aluminum smelter in British Columbia, Canada

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Creator (cre): Blanchard, Dane Alexander, Thesis advisor (ths): Aherne, Julian, Degree committee member (dgc): Watmough, Shaun, Degree committee member (dgc): Sager, Eric P.S., Degree committee member (dgc): McKenna Neuman, Cheryl L, Degree granting institution (dgg): Trent University
Abstract:

Recent developments at an aluminum (Al) smelter in Kitimat, BC resulted in a permitted increase of 27 to 42 tonnes of sulphur dioxide (SO2) emissions per day. Gaseous SO2 is a pollutant known to contribute to acidic deposition through processes of wet and dry deposition and can additionally react in-atmosphere to form particulate sulphate (pSO42-). Between June 2017 to October 2018, an extensive network consisting of ion exchange resin (IER) column, passive-diffusive, and active filter-pack samplers was established to provide an estimate of total annual S deposition and pSO42- variation throughout the Kitimat Valley. Filter-pack sampling determined the relative concentration of pSO42- increased downwind of the smelter. Comparison of observation-based and modelled total annual deposition suggested CALPUFF was accurate in representing the spatial viability of S deposition (R2 = > 0.85). However, the model appeared to overpredict near-field deposition suggesting the potential of underestimation further downwind of the smelter.

Author Keywords: aluminum smelter, atmospheric deposition, filter-pack sampler, ion-exchange column sampler, pSO42-, SO2

2019

Do birds of a feather flock together: An investigation of sandhill crane (Antigone canadensis) populations using non-invasive feathers as a source of DNA

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Creator (cre): Kelly, Crystal, Thesis advisor (ths): Murray, Dennis L, Degree committee member (dgc): Kyle, Chris J, Degree committee member (dgc): Beresford, David V, Degree granting institution (dgg): Trent University
Abstract:

Populations have long been delineated by physical barriers that appear to limit reproduction, yet increasingly genetic analysis reveal these delineations to be inaccurate. The eastern and mid-continent populations of sandhill cranes are expanding ranges which is leading to convergence and warrants investigation of the genetic structure between the two populations. Obtaining blood or tissue samples for population genetics analysis can be costly, logistically challenging, and may require permits as well as potential risk to the study species. Non-invasively collected genetic samples overcome these challenges, but present challenges in terms of obtaining high quality DNA for analysis. Therefore, methods that optimize the quality of non-invasive samples are necessary. In the following thesis, I examined factors affecting DNA quality and quantity obtained from shed feathers and examined population differentiation between eastern and mid-continent sandhill cranes. I found shed feathers are robust to environmental factors, but feather size should be prioritized to increase DNA quantity and quality. Further, I found little differentiation between eastern and mid-continent populations with evidence of high migration and isolation-by-distance. Thus, the two populations are not genetically discrete. I recommend future population models incorporate migration between populations to enhance our ability to successfully manage and reach conservation objectives.

Author Keywords: feathers, genetic differentiation, non-invasive DNA, population genetics, population management, sandhill crane (Antigone canadensis)

2019

Characterization of Synthetic and Natural Se8 and Related SenSm Compounds by Gas Chromatography-Mass Spectrometry

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Creator (cre): Farell, Jana, Thesis advisor (ths): Wallschläger, Dirk, Degree committee member (dgc): Hintelmann, Holger, Degree committee member (dgc): Metcalfe, Chris, Degree granting institution (dgg): Trent University
Abstract:

Elemental selenium has been extensively quantitatively measured in sediments; however, its physical composition is largely unknown, despite it being the dominant selenium species in some reducing environments. Here, for the first time, it is shown that small, cyclic selenium compounds can account for a quantitatively-relevant fraction of the total elemental selenium present.

A new method was developed to analyze for cyclooctaselenium (Se8) in both synthetic samples and selenium-impacted sediments. Despite some analytical limitations, this gas chromatography-mass spectrometry (GC-MS) method is the first GC-MS method developed to identify and quantify Se8 in sediments. Once this method was established, it was then applied to more complex systems: first, the identification of compounds in mixed selenium-sulfur melt solutions, and then the determination of SenSm in selenium-impacted sediments. Despite complications arising from pronounced fragmentation in the ion source, assignment of definitive molecular formulae to chromatographically-resolved peaks was possible for five compounds.

Developing a fully quantitative method to obtain elemental ratio information can aid in the assignment of molecular formulae to chromatographically-resolved SeS-containing chromatographic peaks. Coupling the existing gas chromatography method to an inductively coupled plasma-mass spectrometer (ICP-MS) system should accomplish this. However, due to a number of complications, this was not completed successfully during the duration of this thesis project. High detection limits for sulfur, retention time discrepancies, and inconsistent injection results between the GC-MS and GC-ICP-MS system led to difficulties in comparing results between both analytical methods. Despite these limitations, GC-ICP-MS remains the most promising method for the identification and quantification of SenSm compounds in synthetic melt mixtures and selenium impacted sediments.

Author Keywords: gas chromatography-mass spectrometry, sediments, selenium

2019