Environmental and Life Sciences

Research and development of synthetic materials for presumptive testing in bloodstain pattern analysis: a luminol-reactive forensic blood substitute

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Creator (cre): Polacco, Sumiko Chrysantha, Thesis advisor (ths): Wilson, Paul, Degree committee member (dgc): Stotesbury, Theresa, Degree committee member (dgc): Vreugdenhil, Andrew, Degree granting institution (dgg): Trent University
Abstract:

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. Understanding the whole blood dynamics related to reactivity with presumptive testing chemicals is important for developing accurate analogues. Provided in this thesis is a quantitative and qualitative characterization of photoemission from the reaction of a luminol solution to ovine blood. Luminol reactivity of a horseradish peroxidase encapsulated sol-gel polymer was validated against this ovine blood standard. This material, the luminol-reactive forensic blood substitute, is a key deliverable of this research. An optimized protocol for implementing this technology as a reagent control test, and as a secondary school chemistry experiment are presented. This thesis outlines the research and development of a forensic blood substitute as it relates to presumptive testing in bloodstain pattern analysis.

Author Keywords: bloodstain pattern analysis, forensic science, luminol, presumptive testing, secondary school education, sol-gel chemistry

2018

A wind tunnel based investigation of three-dimensional grain scale saltation and boundary-layer stress partitioning using Particle Tracking Velocimetry

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Creator (cre): O'Brien, Patrick, Thesis advisor (ths): McKenna Neuman, Cheryl, Degree committee member (dgc): McConnell, Sabine, Degree committee member (dgc): Lafleur, Peter, Degree granting institution (dgg): Trent University
Abstract:

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-dimensional dispersion of, nor the momentum carried by particles in flight have been properly measured. This has resulted in the inability to validate numerical particle dispersion models and the key boundary-layer momentum partitioning model that serves as the framework for understanding the air-sand feedback loop. The primary impediment to these measurements being made is a lack of tools suited for the task. To this end, this PhD aims to improve existing particle tracking technology, thus enabling the collection of particle measurements during wind tunnel experiments that would address the aforementioned knowledge gaps.

Through the design and implementation of the Expected Particle Area Searching method, a fully automated particle tracking velocimetry system was developed with the capability to measure within ½ grain diameter of the bed surface under steady state transport conditions. This tool was used to collect the first 3-D data set of particle trajectories, from which it was determined that a mere 1/8th of sand transport is stream aligned and 95% is contained within ± 45o of the mean wind direction. Particles travelling at increasing spanwise angles relative to the stream aligned flow were found to exhibit different impact and ejection velocities and angles. The decrease in the number of particles with increasing height in the saltation cloud, very close to the bed is observed to transition from a power to a linear relation, in contrast to previous literature that observed an exponential decay with coarser vertical resolution.

The first direct measurements of particle-borne stress were captured over a range of wind velocities and were compared with earlier fluid stress measurements taken using Laser Doppler Anemometry. In support of established saltation theory, impacting particle momentum is found to contribute strongly to particle entrainment under equilibrium conditions. In opposition to established theory, however, particle-borne stress was found to reach a maximum above the surface and does not match the change in air-borne stress with increasing distance from the surface. Near surface splashed particles, measured herein for the first time, appear to play a greater role in stress partitioning than previously thought. This study suggests that research is needed to investigate the role of bed load transport on stress partitioning, to differentiate between airborne trajectory types, and to develop particle tracking tools for field conditions.

Author Keywords: Aeolian Transport, Eolian Transport, Particle Tracking Velocimetry, Saltation, Stress Partitioning, Wind Tunnel Simulation

2018

Population Genetics and Scarification Requirements of Gymnocladus dioicus

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Creator (cre): Lumb, Scott, Thesis advisor (ths): Freeland, Joanna R, Degree committee member (dgc): Dorken, Marcel E, Degree committee member (dgc): Beresford, David, Degree granting institution (dgg): Trent University
Abstract:

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 differentiation (3) relative levels of sexual vs. clonal reproduction, and (4) potential for reduced genetic diversity at range edge for wild G. dioicus populations. An analysis of variation at nine microsatellite loci from populations in the core of the species distribution in the U.S.A. and 4 regions of Southwestern Ontario indicated that G. dioicus has remarkably high genetic similarity across its range (average pairwise FST= 0.05). Germination trials revealed that the seed coats require highly invasive treatments (e.g. 17.93 mol/L H2SO4) to facilitate imbibition, with negligible germination observed in treatments meant to emulate prevailing conditions in natural populations. Low levels of sexual reproduction, high genetic similarity, and habitat degradation are issues that exist across the entire native range of G. dioicus.

2018

Hydrochemistry and critical loads of acidity for lakes and ponds in the Canadian Arctic

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Creator (cre): Liang, Tanner, Thesis advisor (ths): Aherne, Julian, Degree committee member (dgc): Gueguen, Celine, Degree committee member (dgc): Lafleur, Peter, Degree granting institution (dgg): Trent University
Abstract:

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', as they integrate processes at a landscape scale. A total of 1300 aquatic sites were assessed for common chemical and physical characteristics. Geology type was found to be the greatest driver of water chemistry for Arctic lakes and ponds. Acid-sensitivity was assessed using the Steady State Water Chemistry model and a subset of 1138 sites from across the Canadian Arctic. A large portion of sites (40.0%, n = 455) were classified as highly sensitive to acidic deposition, which resulted in a median value of 35.8 meq·m―2·yr―1 for the Canadian Arctic. Under modelled sulphur deposition scenarios for the year 2010, exceedances associated with shipping is 12.5% (n = 142) and 12.0% (n = 136) for without shipping, suggesting that impacts of shipping are relatively small.

Author Keywords: Acidic deposition, Arctic lakes, Critical loads, Shipping emissions, Steady-State Water Chemistry Model, Water chemistry

2018

Complex niche determinants in terrestrial salamanders: Does hybridism or reproductive parasitism explain large-scale patterns of distribution?

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Creator (cre): Mills, Peter, Thesis advisor (ths): Murray, Dennis, Degree committee member (dgc): Davy, Christina, Degree committee member (dgc): Shafer, Aaron, Degree granting institution (dgg): Trent University
Abstract:

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 hosts should occupy habitats moderately suitable for hosts. Using niche models, I predicted realized niches for unisexual Ambystoma via a hybrid model (environmental predictors) and a parasite model (host suitability predictors). The hybrid model predicted that the unisexual niche would indeed be transitional between parental Ambystoma spp. The parasite model demonstrated unisexual salamanders occupied habitats moderately suitable for hosts, though model validation did not fully corroborate its predictive power. The hybrid model was more descriptive of unisexual occurrence than the parasite model. When species have competing ecological roles a primary biotic attribute may largely derive the realized niche.

Author Keywords: Ambystoma, hybrid, niche, parasite, range, unisexual

2018

The influence of landscape features on the harvest of caribou (Rangifer tarandus) on the island of Newfoundland

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Creator (cre): McNamara, Jordan, Thesis advisor (ths): Schaefer, James, Degree committee member (dgc): Pond, Bruce, Degree committee member (dgc): Patterson, Brent, Degree granting institution (dgg): Trent University
Abstract:

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 across the island of Newfoundland. Using a landcover map and spatial data for anthropogenic features, I modelled caribou harvest at the island scale for three phases of numerical change (growth in the 1980s, cessation of growth in the 1990s, decline in the 2000s) and harvest type (total harvest, resident harvest of males and females, resident harvest of males, resident harvest of females, and non-resident harvest of males) in relation to multiple putative predictor variables: proportion of lichen cover and distances to nearest forest cut, road, outfitter, transmission line, and town. I did the same analysis for seven individual Caribou Management Areas (CMAs).

At the island scale, the number of harvested caribou increased with proximity to the nearest forest cut and with greater proportions of lichen habitat. I attribute this to landscape features that provide forage for caribou, but also access and caribou visibility for hunters. Caribou harvest increased in proximity to transmission lines for the harvest of caribou by resident hunters in the 2000s, which could be a result of more risk-prone foraging Newfoundland caribou. Non-resident hunters harvested greater numbers of male caribou further from towns, likely a result of the placement of outfitter camps and activities. At the management area scale, in most instances, more caribou harvest occurred in close proximity to transmission lines. Proximity to forest cuts and high proportions of lichen were still important landscape features leading to a greater harvest. I conclude that the caribou harvest was largely governed by hunter access and visibility of their prey, augmented by open habitats preferred by caribou.

KEYWORDS

Caribou, Newfoundland, Rangifer tarandus, harvest, hunting, management area, landscape, human disturbances, game species vulnerability.

Author Keywords: caribou, game species vulnerability, harvest, hunting, newfoundland, rangifer tarandus

2018

Nitrogen Retention of Terricolous Lichens in a Jack Pine Forest in Northern Alberta

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Creator (cre): Bird, Adam, Thesis advisor (ths): Watmough, Shaun, Degree committee member (dgc): Sager, Eric, Degree granting institution (dgg): Trent University
Abstract:

The Athabasca Oil Sands in Alberta, Canada is one of the largest point sources emitters of NOx in Canada and there

are concerns that elevated nitrogen (N) deposition will lead to widespread eutrophication impacts, including altered

species composition, similar to what has occurred in several parts of Europe. Atmospheric deposition rates as high as

25 kg N ha-1 yr-1 have been measured close to the industrial center. The role of the forest floor in regulating these

potential eutrophication effects was investigated following a 5-year enrichment study in which N was applied as

NH4NO3 above the canopy of a jack pine (Pinus banksiana Lamb) stand in northern Alberta close to Fort McMurray

at dosages ranging from 5 – 25 kg N ha-1 yr-1 in addition to background deposition of 2 kg N ha-1 yr-1. Chemical

analysis of lichen mats revealed that apical (upper) lichen tissue N concentration increased with treatment, as did the

necrotic tissue. When expressed as a pool, the fibric-humic (FH) material held the largest quantity of N across all

treatments due to its relatively large mass. Soil net N mineralization and net nitrification rates did not differ among N

inputs after five years of application. A 15N tracer applied to the forest floor showed that N is initially absorbed by the

apical lichen, FH material, and the foliage of the vascular plant Vaccinium myrtilloides in particular. After 2 years,

the FH 15N pool size was elevated and all other measured pools were depleted, indicating a slow transfer of N to the

FH material. Applied 15N was not detectable in mineral soil. The microbial functional gene ammonia monooxygenase

(amoA) was undetectable using PCR screening of mineral soil microbial communities in all treatments, and broad

fungal/bacterial qPCR assays revealed a weak treatment effect on fungal/bacterial ratios in mineral soil. This work

suggests that terricolous lichen mats, which form the majority of ground cover in upland jack pine systems, have a

large capacity to effectively retain elevated N deposition via the formation of stable humus.

Author Keywords: Biogeochemistry, Boreal Ecology, Lichen, Nitrogen Enrichment, Oil Sands

2018

Enhancing post-mortem interval estimates: refinements of technical, morphometrical, and species considerations within forensic entomology

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Creator (cre): Bourne, Donald Richard, Thesis advisor (ths): Beresford, David V, Thesis advisor (ths): Kyle, Christopher J, Degree committee member (dgc): LeBlanc, Helene N, Degree granting institution (dgg): Trent University
Abstract:

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 preserved specimens of the same development stages to assess the effects of killing-preservation techniques on morphology, and I introduce a new method that uses digital photography to examine maggot mouthparts for stage grading of Phormia regina. Digital photographic methods enable live insects to be quantified and improve approximations of physiological age. I then use these digital methods to produce a growth-rate model for a beetle commonly found on human remains, Necrodes surinamensis, providing data for PMI estimates that was previously unavailable.

Author Keywords: Forensic Entomology, Insect development, Morphometrics, Necrodes surinamensis, Phormia regina, Postmortem interval

2018

Frog Virus 3: Tracking Viral Spread using Molecular Tools

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Creator (cre): Grant, Samantha Adrianna, Thesis advisor (ths): Kyle, Christopher J, Thesis advisor (ths): Brunetti, Craig R, Degree committee member (dgc): Wilson, Chris C, Degree granting institution (dgg): Trent University
Abstract:

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, across Canadian waterbodies. I explored the temporal patterns and spatial distribution of ranavirus presence across multiple months and seasons using environmental DNA techniques. Results indicate that ranavirus was present in approximately 72.5% of waterbodies sampled on a fine geographical scale (<10km between sites, 7,150 km2), with higher detection rates in later summer months than earlier. I then explored the sequence variability at the major capsid protein gene (MCP) and putative virulence gene (vIF-2α) of FV3 samples from Ontario, Alberta, and the Northwest Territories, with the premise of understanding pathogen movement across the landscape. However, a lack of genetic diversity was found across regions, likely due to a lack of informative variation at the chosen genetic markers or lack of mutation. Instead, I found a novel FV3-like ranavirus and evidence for a recombinant between FV3 and a ranavirus of another lineage. This thesis provides a deeper understanding into the spatio-temporal distribution of FV3, with an idea of how widespread and threatening ranaviruses are to amphibian diversity.

Keywords: ranavirus, frog virus 3, amphibians, environmental DNA, phylogenetics, wildlife disease, disease surveillance, major capsid protein, vIF-2α

Author Keywords: amphibians, environmental DNA, frog virus 3, phylogenetics, ranavirus, wildlife disease

2018

Moss Biomonitoring of Trace Element Deposition in Northwestern British Columbia, Canada

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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:

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 of this study was a spatial assessment of trace element deposition across a region with a known large-point source of emissions using the moss biomonitoring method. Moss tissues presented strong correlations with modelled deposition in the region, suggesting mosses are a valuable biomonitoring tool of trace element deposition, especially in regions dominated by large-point emission sources. Additionally, a moss species endemic to Canada was compared to commonly used moss species with results indicating this species (Isothecium stoloniferum) can be used reliably as a biomonitor. Moss biomonitoring is recommended as a compliment to fill in spatial gaps in current monitoring networks across the country.

Author Keywords: biomonitoring, bryophytes, Hylocomium splendens, moss, Pleurozium schreberi, trace elements

2018