Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Levasseur, Patrick, Thesis advisor (ths): Watmough, Shaun, Degree committee member (dgc): Aherne, Julian, Degree committee member (dgc): Eimers, Catherine, Degree committee member (dgc): Whitfield, Colin, Degree granting institution (dgg): Trent University Abstract: <p>In 2012, the Rio Tinto aluminum smelter in Kitimat, British Columbia increased sulphur dioxide (SO2) emissions from 27 to 42 tonnes/day. An initial study was conducted to investigate the effect of the increased sulphur (S) deposition on forest soils. A key uncertainty of the initial study was mineral surface area estimations that were applied to critical load calculations. The current… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Microalgae are a promising source of valuable compounds relevant to biofuels, biomaterials, nutraceuticals as well as animal and human nutriment. Unfortunately, low cell density and slow growth result in reduced economic feasibility. Heterotrophic cell culturing using an organic carbon source in lieu of light has proven to be an effective alternative to photobioreactors; however, further… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Introgressive hybridization between northern (Glaucomys sabrinus) and southern flying squirrels (G. volans) has been observed in some areas of Canada and the USA. However, existing molecular markers lack the resolution to discriminate late-generation introgressants and describe the extent to which hybridization influences the Glaucomys gene pool. I report the first North American flying… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Cowden, Phaedra, Thesis advisor (ths): Aherne, Julian, Degree committee member (dgc): Watmough, Shaun, Degree committee member (dgc): Sager, Eric, Degree committee member (dgc): Canners, Richard, Degree granting institution (dgg): Trent University Abstract: <p>Atmospheric pollutant deposition poses a risk to ecosystem health; therefore, monitoring the spatial and temporal trends of deposition is integral to environmental sustainability. Although moss biomonitoring is a common method to monitor various pollutants in Europe, offering a cost-effective approach compared to traditional methods of monitoring, it is rarely used in Canada. The focus… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Understanding the maintenance and spread of invasive diseases is critical in evaluating threats to biodiversity and how to best minimize their impact, which can by done by monitoring disease occurrences across time and space. I sought to apply existing and upcoming molecular tools to assess fluctuations in both presence and strain variation of frog virus 3 (FV3), a species of Ranavirus,… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The growth of immature insects that develop on human remains can be used to estimate a post-mortem interval (PMI). PMI estimate confidence is negatively affected by: larval killing and preservation methods altering their size, limited morphological parameters to assess larval growth and therefore age, and few available alternate species development data. I compared live specimens to… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The Athabasca Oil Sands in Alberta, Canada is one of the largest point sources emitters of NOx in Canada and there</p><p>are concerns that elevated nitrogen (N) deposition will lead to widespread eutrophication impacts, including altered</p><p>species composition, similar to what has occurred in several parts of Europe. Atmospheric deposition rates as high as</… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Hunting represents the principal tool for managing populations of migratory caribou (Rangifer tarandus), but harvest may be affected by landscape features that govern animal distribution and hunter access. Such effects are unclear. I capitalized on an existing dataset of 21 355 caribou harvest records, 1980 – 2009, to determine the influence of landscape features on caribou harvest… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>I assessed how organisms having multiple biotic attributes may have conflicting niche determinants, and whether the realized niche reflects single or multiple attributes. All-female salamanders engage in two biotic states: hybridism and reproductive parasitism. Hybrids should occupy areas transitional to those used by parental species, whereas parasites that engage in competition with… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Threats such as climate change and increased anthropogenic activity such as shipping, are expected to negatively affect the Arctic. Lack of data on Arctic systems restricts our current understanding of these sensitive systems and limits our ability to predict future impacts. Lakes and ponds are a major feature of the Arctic landscape and are recognized as 'sentinels of change… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The Kentucky coffee tree (Gymnocladus dioicus) is an endangered tree species native to the American Midwest and Southwestern Ontario. Significant habitat loss and fragmentation due to agricultural, industrial and urban development has caused gradual decline across its native range. The aims of this study were to investigate: (1) patterns of genetic diversity and, (2) genetic… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Aeolian transport of sand particles is an important geomorphic process that occurs over a significant portion of the earth's land surface. Wind tunnel simulations have been used for more than 75 years to advance the understanding of this process; however, there are still several principles that lack validation from direct sampling of the sand particles in flight. Neither the three-… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Chemical presumptive tests are used as the primary detection method for latent bloodstain evidence. This work focuses on developing a forensic blood substitute which mimics whole blood reactivity to a luminol solution commonly used in presumptive testing. Designing safe and accessible materials that mimic relevant properties of blood is a recognized research need in forensic science.… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Numerous prey taxa employ defensive postures for protection against attack by predators. Defensive postures mitigate predation risk at various stages of the predator-prey sequence, including through crypsis, mimicry, thanatosis, aposematism, and deflection. In terrestrial salamanders, defensive postures may be aposematic, or deflect attacks away from vital body parts and towards the tail… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Salamanders are capable of tissue regeneration throughout all life-stages, which requires the dedifferentiation of mature cells to regrow lost tissues. Dedifferentiation is promoted by degradation of the extracellular matrix by matrix metalloproteases, as well as lysosomal degradation of intracellular and cell-surface proteins that mark cells as part of a mature lineage. Salamanders are… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Neuroblastoma (NB) has one of the highest mortality rates in pediatric oncology due to relapsed and refractory disease. Current aggressive multi-modal treatments are inhibited by dose-limiting toxicities and are associated with late-effects and secondary malignancies, emphasizing the necessity for novel therapeutics. Uniquely, most NB cells highly express disialoganglioside (GD2) a cell… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Samkari, Bshayer A, Thesis advisor (ths): Beresford, David, Degree committee member (dgc): Hutchinson, Tom, Degree committee member (dgc): Sager, Eric, Degree committee member (dgc): Davy, Christina, Degree granting institution (dgg): Trent University Abstract: <p>This thesis looks at the genus Pollenia: historically where they were first introduced into Canada and spatially, where they are found now. This project involved me identifying 2211 files, sorted from the 3 years of field specimens obtained in 2011, 2012, 2013. P. pediculata was the most abundant and widespread, yielding 1272 specimens out of 2211, and it was found in all provinces… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Soluble uranium (U) has been observed continuously in the porewaters of Bentley Lake,</p><p>a lake with semi-permanent anoxic sediments, despite the fact that reduced U(IV) is known to be</p><p>insoluble. To be able to predict the fate and mobility of U that has been deposited in lake</p><p>sediments, it is very important to understand the factors that… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Environmental DNA (eDNA) metabarcoding targets sequences with interspecific</p><p>variation that can be amplified using universal primers allowing simultaneous detection</p><p>of multiple species from environmental samples. I developed novel primers for three</p><p>barcodes commonly used to identify plant species, and compared amplification success… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The potential impacts of domestic wastewater (DWW) on the source of drinking water for the M'Chigeeng First Nation were monitored as part of the development of a Source Water Protection plan. During a period of continuous overflow of the Gaaming Wastewater Lagoon serving the community, the chemical tracers, caffeine and sucralose were tracked in West Bay with Passive Organic… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Chimney swifts are listed as Threatened nationally and in many provinces within Canada due to rapid population declines. I examined large-scale spatial variation in the maximum size of chimney swift roosts at the northern edge of their range to identify where larger roosts occur. I used multi-sourced data collected across Ontario and Quebec between 1998 and 2013. I found that larger… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Ustilago maydis is a biotrophic fungal plant pathogen that causes 'common smut of corn' disease. During infection, U. maydis develops a metabolic dependency on its host, relying on uptake of the carbon molecules provided within Zea mays tissues. The research presented indicated a requirement for metabolism of the pentose sugar D-xylose through functional investigation of a U.… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): McClenaghan, Beverly, Thesis advisor (ths): Nol, Erica, Degree committee member (dgc): Nocera, Joseph J, Degree committee member (dgc): Beresford, David V, Degree committee member (dgc): Kerr, K, Degree granting institution (dgg): Trent University Abstract: <p>Barn Swallow (Hirundo rustica) populations have declined in North America over the past 40 years and they are listed as Threatened in Ontario, Canada. Changes in the food supply have been hypothesized as a potential cause of this population decline. I used DNA barcoding to investigate the diet and food supply of Barn Swallows and to determine if the food supply affects their reproductive… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Pastures and hayfields provide surrogate habitat for many declining grassland birds. Understanding agricultural land use dynamics and habitat quality can impact conservation of grassland species. I investigated 1) patterns of land use change in protected and unprotected sites in relationship to Bobolink occurrence in Carden, Ontario, Canada and 2) whether continuous grazing at low… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Drivers of North American Barn Swallow population declines are not well understood, but foraging habitat loss is thought to be a contributing factor. Determining patterns of habitat use is challenging for swallows because they move rapidly but are too small to carry GPS tags. We showed that automated radio-telemetry could be used to track the movements of swallows with enough accuracy (… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Resources and risk are in constant flux and an organism's ability to manage change may improve their likelihood of persistence. I examined intra-seasonal variation in nest-site selection and survival of a declining wetland bird, the Black Tern (Chlidonias niger surinamensis). I modelled nest site occupancy and survival of early and late-nesting birds as a function of static and… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>North American freshwater fishes are declining rapidly due to habitat fragmentation, degradation, and loss. In some cases, translocations can be used to reverse local extirpations by releasing species in suitable habitats that are no longer naturally accessible. Lake sturgeon (Acipenser fulvescens) experienced historical overharvest across their distribution, leading to endangered… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The network composition hypothesis (NCH) suggests that i) large confluence symmetry ratios (drainage area of the tributary relative to the mainstem) and ii) landscape differences (differences in landscape characteristics between the mainstem and tributary drainages) lead to greater ecological changes below confluences. As a test of the NCH, 34 confluences were sampled in southern Ontario… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Preston, Colette Alexia, Thesis advisor (ths): McKenna Neuman, Cheryl, Degree committee member (dgc): Boulton, Wayne, Degree committee member (dgc): Buttle, James, Degree committee member (dgc): Eimers, Catherine, Degree granting institution (dgg): Trent University Abstract: <p>A series of experiments was designed to assess the relative efficacy of various dust suppressants to suppress PM10 emissions from nepheline syenite tailings. The experiments were conducted in the Trent University Environmental Wind Tunnel, Peterborough, Ontario, and on the tailings ponds at the Unimin Ltd Nephton mine near Havelock, Ontario. Treated surfaces were subjected to particle-… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>To better understand species' resilience to climate change and implement solutions, we must conserve environments that maintain standing adaptive genetic variation and the potential generation of new beneficial alleles. Coding trinucleotide repeats (cTNRs) providing high-pace adaptive capabilities via high rates of mutation are ideal targets for mitigating the decline of species at… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>This study seeks to clarify the way in which the differing canopy characteristics among tree species influence the partitioning of precipitation, and therefore the source of water available for plant water uptake, in the Plastic Lake catchment near Dorset, ON. Three dominant tree species were compared: red oak (Quercus rubra), eastern white pine (Pinus strobus), and eastern hemlock (… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>According to the Invasional Meltdown Hypothesis (IMH), invasive species may interact in their introduced range and facilitate future invasions. This study investigated the possibility that Alliaria petiolata, an invasive allelopathic herbaceous plant in Ontario, is facilitating invasions by additional alien species. Two allelopathic focal species were chosen for this study: the native… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Wehtje, Morgan, Thesis advisor (ths): Bowman, Jeff, Thesis advisor (ths): Murray, Dennis, Degree committee member (dgc): Fortin, Marie Josee, Degree committee member (dgc): Wilson, Paul, Degree granting institution (dgg): Trent University Abstract: <p>Range contractions and expansions are important ecological concepts for species management decisions. These decisions relate not only to rare and endangered species but to common and invasive species as well. The development of the broad spatiotemporal extent models that are helpful in examining range fluctuations can be challenging given the lack of data expansive enough to cover the… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Increases in flooding due to anthropogenic influences such as climate change and reservoir creation will undoubtedly impact aquatic ecosystems, affecting physical, chemical, and biological processes. We used two approaches to study these impacts: a whole-ecosystem reservoir flooding experiment and a systematic literature review. In the whole-ecosystem experiment, we analyzed the impact… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Leaf litter decomposition represents a major pathway for nutrient cycling and carbon flow in aquatic ecosystems, and macroinvertebrates play an important role in the processing of this material. To assess the causes of variable leaf breakdown and nutrient fluxes, I measured decomposition rates and the nutrient release ratios of decomposing leaf material across a broad latitudinal… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Cytokinins (CKs) are hormones that promote cell division. During the formation of tumors in the Ustilago maydis-Zea mays pathosystem, the levels of CKs are elevated. Although CK levels are increased, the origins of these CKs have not been determined and it is unclear as to whether they promote the formation of tumors. To determine this, we measured the CK levels, identified CK… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Effective population size (Ne) is a foundational concept in conservation biology, in part due to its relationship to the adaptive potential of populations. Although Ne is often estimated for wild populations, it is rarely calibrated against actual population estimates (Nc) other than to produce Ne/Nc ratios. This project used demographic and genetic data for from two intensively-studied… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>While both resource quality and predator-derived chemical cues can each have profound effects on zooplankton populations and their function in ecosystems, the strength and nature of their interactive effects remain unclear. We conducted laboratory experiments to evaluate how stoichiometric food quality (i.e., algal carbon (C):phosphorus (P) ratios) affects responses of the water flea,… more
Year: 2018, 2018
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Stream solutes are strongly linked to hydrology, and as such, we sought to better understand how hydrology, particularly flooding, influences nitrogen (N) and phosphorus (P) levels. We used a long-term dataset of monthly water quality samples for many Ontario, Canada, catchments to assess the effects of landscape variables, such as land use and physiography, on the export of nutrients… more