English

Social discrimination by female polar bears (Ursus maritimus) when accompanied by dependent offspring during the ice-free season in southern and western Hudson Bay and James Bay

Type:
Names:
Creator (cre): Mondoux, Courtney C., Thesis advisor (ths): Wilson, Paul J, Thesis advisor (ths): Obbard, Martyn E, Degree committee member (dgc): Petersen, Stephen D, Degree granting institution (dgg): Trent University
Abstract:

Polar bears are generally described as solitary, but features of their life cycles and

habitats regularly necessitate interaction. Effective conspecific assessment, including accurate

recognition and discrimination, likely confers benefits, especially to females accompanied by

dependent young. Individuals in the Southern (SH) and Western (WH) Hudson Bay

subpopulations are ideal for studying polar bear social behaviours because of the prolonged

high densities of the ice-free season. First, I looked outside family groups to model their fine

scale sociospatial organization on land. Capture locations were more likely to correspond to

family groups when there were fewer neighbouring bears, when a greater proportion of

neighbours were female, and when the focal individual and neighbours were significantly

related. Second, I looked within the family group to assess offspring recognition. Of 288

offspring in 207 family groups captured in the SH subpopulation from 1999 through 2013, only

one case of adoption (of a singleton) was observed.

Author Keywords: Adoption, Kin Recognition, Logistic Regression, Maternity Analysis, Social Discrimination, Sociospatial

2017

Enhancing forensic entomology applications: identification and ecology

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Names:
Creator (cre): Langer, Sarah Victoria Louise, Thesis advisor (ths): Beresford, David V, Thesis advisor (ths): Kyle, Christopher J, Degree committee member (dgc): Freeland, Joanna R, Degree granting institution (dgg): Trent University
Abstract:

The purpose of this thesis is to enhance forensic entomology applications through identifications and ecological research with samples collected in collaboration with the OPP and RCMP across Canada. For this, we focus on blow flies (Diptera: Calliphoridae) and present data collected from 2011-2013 from different terrestrial habitats to analyze morphology and species composition. Specifically, these data were used to: 1) enhance and simplify morphological identifications of two commonly caught forensically relevant species; Phormia regina and Protophormia terraenovae, using their frons-width to head-width ratio as an additional identifying feature where we found distinct measurements between species, and 2) to assess habitat specificity for urban and rural landscapes, and the scale of influence on species composition when comparing urban and rural habitats across all locations surveyed where we found an effect of urban habitat on blow fly species composition. These data help refine current forensic entomology applications by adding to the growing knowledge of distinguishing morphological features, and our understanding of habitat use by Canada's blow fly species which may be used by other researchers or forensic practitioners.

Author Keywords: Calliphoridae, Ecology, Forensic Entomology, Forensic Science, Morphology, Urban

2017

Fate and Effects of Silver Nanoparticle Addition in a Lake Ecosystem

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Creator (cre): Rearick, Daniel C, Thesis advisor (ths): Xenopoulos, Marguerite A, Degree committee member (dgc): Hickie, Brendan E, Degree committee member (dgc): Hintelmann, Holger, Degree granting institution (dgg): Trent University
Abstract:

The potential release of nanoparticles into aquatic environments is raising global concerns. As antimicrobials, silver nanoparticles (AgNPs) are among the most prominent form in use. Despite this, their fate, long-term toxicity, and ecological relevance have yet to be investigated largely under natural settings with seasonality and environmental complexity. To better understand the environmental significance, we released AgNPs into Lake 222 at the Experimental Lakes Area over two years. AgNPs remained suspended in the water column and were detected throughout the lake and in the lower food web. Total Ag concentrations ranged from below 0.07 to 18.9 μg L-1 in lake water, and were highly dynamic seasonally both in the epilimnion and hypolimnion depending on the physical, chemical and biological conditions of the lake. Approximately 60% of the measured Ag mass in October was present in the sediment in 2014 and 50% in 2015 demonstrating relatively high sedimentation and removal from the water column. During winter months, Ag was largely absent in the water column under the ice. After ice melt and before summer stratification, Ag concentrations increased in the lake suggesting AgNPs may not be tightly bound to the sediment and are able re-enter the water column during spring mixing events. Despite temporal variation, total Ag was highly synchronous across spatial locations for both years, indicating rapid dispersal upon lake entry. When investigating AgNP sizes using spICPMS, size distributions were similar across spatial locations, with the 40-60 nm size class constituting approximately 60% of all particles identified. Large aggregates (>100 nm) and dissolved Ag were infrequently detected within the lake. Ag accumulated in the lower food web ranging from 0.27-16.82 μg Ag mg C-1 in the bacterioplankton and 0.17-6.45 μg Ag mg C-1 in algae (particulate fraction). Partial least squares models revealed the highest predictors of Ag accumulation were dissolved nutrients including DOC, TDN, TDP in bacterioplankton. Major predictors for particulate Ag included temperature, dissolved oxygen, and sampling date. The diversity of predictors among biological compartments emphasizes the importance of understanding the role of environmental complexity within the lower food web. Despite Ag accumulation we did not detect strong negative effects on the lake food web. An increase in particulate and bacterioplankton chlorophyll-a occurred after addition in contrast to reference lakes, which may indicate a hormetic response to low dose AgNP concentrations. Our findings provide the first whole-lake perspective regarding Ag fate and toxicity, suggesting small scale experiments may overestimate environmental

responses.

Author Keywords: Ecotoxicity, Fate, Lower food web, Silver Nanoparticles, Whole-lake addition

2017

Jail Time: Effects of Attachment, Gender, and Contact on the Associations Between Parental Incarceration, Offspring Symptoms and Delinquency

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Names:
Creator (cre): Reid, Jessica Lynn, Thesis advisor (ths): Scharfe, Elaine, Degree committee member (dgc): Navara, Geoff, Degree granting institution (dgg): Trent University
Abstract:

Children of incarcerated parents are an understudied at-risk population. However, this thesis was designed to advance our understanding of the effects of parental incarceration and factors that may influence the impact. Using quantitative methods, possible moderating roles of gender, number of incarcerated parents, and contact frequency on the associations between attachment representations and problem behaviours were investigated in two samples. Results revealed that the number of incarcerated parents and contact frequency with incarcerated parents moderated the associations between attachment and externalizing behaviours. Furthermore, after controlling for several factors (e.g., gender, number of incarcerated parents, and contact) higher scores on secure parental attachment representations were consistently negatively associated with internalizing symptoms and externalizing behaviours. The discussion of findings highlight the utility of attachment theory in conceptualizing the impact of parental incarceration and the importance of fostering attachment security to promote positive mental health and behavioural outcomes for children of incarcerated parents.

Author Keywords: attachment, internalizing symptoms, parental incarceration, problem behaviours

2017

Linking Inuit and Scientific Knowledge and Observations to Better Understand Arctic Char (Salvelinus alpinus (L.)) Community Monitoring

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Creator (cre): Knopp, Jennie A., Thesis advisor (ths): Furgal, Chris M, Degree committee member (dgc): Whillans, Tom, Degree committee member (dgc): Reist, James D, Degree granting institution (dgg): Trent University
Abstract:

Arctic Char (Salvelinus alpinus (L.)) have been, and remain, an important

subsistence resource for the Inuvialuit, the Inuit of the western Canadian Arctic. The effects

of climate variability and change (CVC) in this region have been noticeably increasing over

the past three decades. There are concerns as to how CVC will affect Arctic Char and the

Inuvialuit who rely on this resource as they will have to adapt to changes in the fishery.

Community-based monitoring, is an important tool for managing Arctic Char. Therefore,

my dissertation focused on the central question of: Which community-based monitoring

factors and parameters would provide the information needed by local resources

users and decision-makers to make informed choices for managing Arctic Char

populations in light of CVC?

This question is investigated through an exploratory research approach and a mixed

method research design, using both scientific and social science methods, and quantitative

(scientific ecological knowledge and observation) and qualitative (Inuvialuit knowledge

and observation) information. It is formatted as three journal manuscripts, an introduction,

and an integrative discussion. The first manuscript examines potential habitat parameters

for monitoring landlocked Arctic Char condition in three lakes on Banks Island in the

Inuvialuit Settlement Region. The second manuscript examines potential local

environmental parameters for monitoring landlocked Arctic Char growth in the same three

lakes. The third manuscript investigates aspects of Arctic Char community-based

monitoring programs (CBMP) in the Canadian North that have led to the sustained

collection of useful data for management of the resource.

This dissertation makes contributions to the field of research by demonstrating the

utility of a mixed methods approach. The results demonstrate similarities and differences

in char growth and condition within and among Capron, Kuptan and Middle lakes on Banks

Island. This supports both lake-specific and regional climate-driven changes, meaning both

lake habitat and local environmental monitoring parameters should be used in char CBMP.

The investigation of char CBMP across northern Canada demonstrates that an adaptive

monitoring approach is important for subsistence fisheries, as changing lifestyles and

environmental changes impacting a fishery can have direct effects on the successful

operation of char CBMP.

Author Keywords: Arctic Char, community-based monitoring, environment, Inuit Knowledge, mixed methods, Traditional Knowledge

2017

Thinking Ahead: Stakeholder Perspectives on Transitioning Media Change for Communication between Health Care Providers and Employers During Return to Work

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Names:
Creator (cre): Savinder Singh, Ripdaman Singh, Thesis advisor (ths): O'Hagan, Fergal, Degree committee member (dgc): Kennett, Deborah, Degree granting institution (dgg): Trent University
Abstract:

The present thesis entails a qualitative investigation of the unique notion to transition media change from the current paper-based system to the potential use of information technology innovation for communication between health care providers and employers during return to work. Stakeholder perspectives on relevant communication phenomena were gathered from workers, employers, and health care providers with experience in return to work. Methods for analysis involved critical realist grounded theory, as well as the use of a prototype innovation, named the Return to Work Expert App, as a platform for participant evaluation and discourse. The study's findings provided comprehensive and in-depth understanding of return to work communication, beyond its empirical regularities. The generative mechanisms of common communication problems that were discovered included situated reasoning, media as information ("the medium is the message"), epistemological disjuncture, egoism-altruism-collectivism quandary, and perspective taking. A novel theoretical framework based on ecological psychology was also advanced to offer a coherent and systematic understanding of the situated nature of health care providers' reasoning and information development. Media change via the Return to Work Expert App was argued to be limited in handling and resolving many of the communication problems that can occur. However, the app had perceptible value and benefits to prospective users that suggested a distinct advantage over current paper-based practices. Opportunities for further development and research exist to address relevant challenges, most notable of all being the need to address the app's burden of proof. For the interested reader, this thesis advances research and knowledge of provider-employer communication to a state that is truly fitting of the importance acknowledged of it in the field of return to work.

Author Keywords: critical realism, ecological psychology, media change, return to work, stakeholder communication, technological acceptance

2017

An Ethical Analysis of Bell's Targeted Ad Prorgram

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Names:
Creator (cre): Rowe, Brendan, Thesis advisor (ths): Hickson, Michael, Thesis advisor (ths): Hurley, Richard, Degree granting institution (dgg): Trent University
Abstract:

Online behavioural advertising (OBA) is an advertising technique which relies on collected customer information and online activity to serve people with more relevant ads. On November 16th, 2013, Bell Canada launched their first OBA program via Bell Mobility: the Bell Targeted Ads Program, or BTAP. My thesis provides an ethical analysis of BTAP and shows that Bell undermined and violated customer privacy, stifled customer autonomy, and harmed customer identity. Relevant moral problems include typification, a disrespecting of customer autonomy, and identity commodification.

I show that BTAP was unethical by grounding my arguments within the moral framework of Information Ethics (IE). IE is an ethical system which focuses on the role of information in the ethical dilemmas. IE also justifies the self-constitutive theory of privacy (SCP) which argues that our information and privacy are entangled with our identities. This gives us strong reason to defend our privacy/identity within BTAP.

After making several arguments which demonstrate that BTAP was unethical, I will then turn my attention to showing how it is possible to rectify and mitigate many of BTAP's ethical problems by installing a two-stage opt-in (TSOI) which provides customers with a greater deal of autonomy, and the ability to remove themselves from BTAP.

Author Keywords: Bell Canada, Ethics, Identity, Online Behavioural Advertising, Privacy, Targeted Advertising

2017

Assessing the Clinical Usefulness of Three Tablet-Based Visuomotor Tasks to Evaluate Closed Head Injury

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Names:
Creator (cre): Livermore, Jasmine, Thesis advisor (ths): Brown, Liana E, Thesis advisor (ths): Lehmann, Hugo, Degree granting institution (dgg): Trent University
Abstract:

Evidence suggests that visuomotor system behaviour may be more sensitive to the prolonged effects of mild brain injuries than neuropsychological tests. We evaluated whether participants with a mild closed head injury (CHI) would show lingering visuomotor deficits, but not cognitive deficits, up to three years post-injury compared to participants with an orthopaedic injury and healthy controls. All three groups completed a tablet-based visuomotor assessment tool and a brief neuropsychological test battery. The CHI participants scored comparable to the control groups on the neuropsychological tests, but when assessed for visuomotor function requiring adjustment to a changing stimulus, CHI participants showed poorer performance than the control groups. Combined, these findings add to the evidence that CHI can lead to persistent visuomotor deficits that extend beyond those of neuropsychological tests. Therefore, visuomotor assessment should be included in brain injury and recovery evaluation, and this can be accomplished easily using tablet-based tasks.

Author Keywords: closed head injury, neuropsychological assessment, recovery, tablet, traumatic brain injury, visuomotor

2019

Phosphoric Acid Chemically Activated Waste Wood: Production, Modification and Selenium Adsorption

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Creator (cre): Strong, Oliver Luke, Thesis advisor (ths): Vreugdenhil, Andrew, Degree committee member (dgc): Easton, Brad, Degree committee member (dgc): Slepkov, Aaron, Degree granting institution (dgg): Trent University
Abstract:

Activated Carbon (AC) is commonly produced by gasification, but there has been increasing interest in chemical activation due to its lower activation temperatures and higher yields. Phosphoric acid, in particular, succeeds in both these areas. Phosphoric acid activated carbon (PAC) can be environmentally sustainable, and economically favourable, when the phosphoric acid used in the activation is recycled. This thesis describes the digestion and activation of waste wood using phosphoric acid, as well as methods used to recover phosphoric acid, functionalize the produced activated carbon with iron salts and then test their efficacy on the adsorption of target analytes, selenite and selenate. In order to achieve an efficient phosphoric acid based chemical activation, further understanding of the activation process is needed. A two-step phosphoric acid activation process with waste wood feed stock was examined. The filtrate washes of the crude product and the surface composition of the produced PAC were characterized using X-ray Photoelectron Spectroscopy (XPS), Fourier Transform-Infrared spectroscopy (FT-IR), Ion Chromatography (IC), and 31P Nuclear Magnetic Resonance (NMR). XPS of the unwashed PAC contained 13.3 atomic percent phosphorous, as phosphoric acid, while the washed sample contained 1.4 atomic percent phosphorous as PO43-, and P2O74-. Using 31P NMR, phosphoric acid was identified as the primary phosphorous species in the acidic 0.1 M HCl washings, with pyrophosphates also appearing in the second 0.1 M NaOH neutralizing wash, and finally a weak signal from phosphates with an alkyl component also appearing in the DI wash. IC showed high concentrations of phosphoric acid in the 0.1 M HCl wash with progressively lower concentrations in both the NaOH and DI washes. Total phosphoric acid recovery was 96.7 % for waste wood activated with 25 % phosphoric acid, which is higher than previous literature findings for phosphoric acid activation. The surface areas of the PAC were in the 1500-1900 m2g-1 range. Both pre and post activation impregnation of iron salts resulted in iron uptake. Pre-activation resulted in only iron(III) speciation while post-activation impregnation of iron(II)chloride did result in iron(II) forming on the PAC surface. The pre-activated impregnated PAC showed little to no adsorption of selenite and selenate. The post-activation impregnated iron(II)chloride removed up to 12.45 ± 0.025 mg selenium per g Iron-PAC. Competitive ions such as sulfate and nitrate had little effect on selenium adsorption. Phosphate concentration did affect the uptake. At 250 ppm approximately 75 % of adsorption capacity of both the selenate and the selenite solutions was lost, although selenium was still preferentially adsorbed. Peak adsorption occurred between a pH of 4 and 11, with a complete loss of adsorption at a pH of 13.

Author Keywords: Activated Carbon, doping, Iron, phosphoric acid, selenium

2019

Population-Level Ambient Pollution Exposure Proxies

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Names:
Creator (cre): Scott, Carlone Livingston, Thesis advisor (ths): Burr, Wesley S, Degree granting institution (dgg): Trent University
Abstract:

The Air Health Trend Indicator (AHTI) is a joint Health Canada / Environment and Climate Change Canada initiative that seeks to model the Canadian national population health risk due to acute exposure to ambient air pollution. The common model in the field uses averages of local ambient air pollution monitors to produce a population-level exposure proxy variable. This method is applied to ozone, nitrogen dioxide, particulate matter, and other similar air pollutants.

We examine the representative nature of these proxy averages on a large-scale Canadian data set, representing hundreds of monitors and dozens of city-level populations. The careful determination of temporal and spatial correlations between the disparate monitors allows for more precise estimation of population-level exposure, taking inspiration from the land-use regression models commonly used in geography. We conclude this work with an examination of the risk estimation differences between the original, simplistic population exposure metric and our new, revised metric.

Author Keywords: Air Pollution, Population Health Risk, Spatial Process, Spatio-Temporal, Temporal Process, Time Series

2019