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Mercury in gull (Larus argentatus) guano samples and changes over two summer seasons on Brier Island, Nova Scotia
No full textBiovectors are organisms that can transport contaminants and nutrients to remote locations through excretion, moulting and decomposition of carcasses. Herring gulls (Larus argentatus) are typically top predators of aquatic systems, which increases their exposure to methylmercury through biomagnification. Methylmercury is known for its neurotoxicity and estrogenic effects on organisms. Big Meadow Bog on Brier Island is the summer (May-August) nesting site for ~6000 herring gulls (Larus argentatus). In order to obtain unaffected guano samples, five plastic posts were deployed in the most populated areas of the bog for birds to perch and excrete on. Guano samples were collected every two weeks in summer; totalling 10 sampling trips over two years. A total of 43 guano samples were dried, homogenized and analyzed for total mercury, extractable phosphate and sulphate. This study demonstrated gulls were depositing THg and considerable PO43-throughout their nesting season. It also highlighted that there was a significant decreasing trend of THg
from May through September, which suggests that gulls were potentially switching to aquatic food sources when their young hatched . This would contribute to increased THg values in their guano at the start of their nesting period. I suggest that analysing MeHg, in tandem with THg, would provide more insights into the movement and metabolism of nutrients and contaminants within seabirds
Locating old growth forests in the Annapolis Valley, Nova Scotia with a review of forest management and legislation
No full textAn old growth forest is one of many stages of forest development and plays an important role in maintaining global biodiversity and the hydrologic and carbon cycles. Prior to European colonization, old growth likely covered up to 50% of forest land in Nova Scotia. However, today it is estimated less than 0.9 percent of forest land outside of ecological preserves is old growth, and likely even less is found in the Annapolis Valley region due to its long history of agriculture, fire and development. This research sought to locate any remaining old growth stands in the Annapolis Valley, Nova Scotia and to assess their ecological integrity using the NS Old Forest Policy Scoresheet. GIS querying and satellite imagery analyses found 16851 ha of the study area had a high potential to contain old growth. Of this area, 27% was found to be old growth forest. The following literature review examined the history of forestry practices in Nova Scotia and discusses the ways a forest can be valued either economically or ecologically. Values placed on forests can subsequently influence the preservation or destruction of old growth forest characteristics. Due to their important ecological roles, old growth forests are of high conservation value and the sites found in this research should guide future conservation efforts by providing high priority areas for protection
The relation between levels of construals and psychological well-being in long- and short-term situations
No full textThe present study examined the relationship between levels of construal and psychological well-being in short- and long-term situations. The purpose of this study was to investigate whether low-level construals were
associated with psychological wel-being in short-term situations, while high-level construals were associated with psychological well-being in the long term. Fifty-seven undergraduate students at Acadia University from the Introductory Psychology classes were recruited to participate in the study through an online experiment registration program (SONA). Participants were asked to fill out online survey questionnaires that took
approximately 35-45 minutes to complete. The online survey included a demographic questionnaire, the Situations and Construals Questionnaire (SCQ), which measured construal levels in situations, the Scales of
Psychological Well-Being (SPWB), the Adult Hope Scale (AHS), and the Life Orientation Test-Revised (LOT-R) for the participants to complete. Stepwise multiple regression analyses were conducted to test the hypotheses. Contrary to prediction, the results showed that high-level construals were the best predictors of overall psychological well-being in both types of situations. High-level construals in both long- and short-term situations were the best predictors of hope. Lastly, high-level construals in short-term situations were the best predictors for optimism. The results of the present study highlight the association of high-level
construals with psychological well-being
Adult attachment styles and caregiver attitudes when raising a virtual child: the roles of desire to have children and specific attachment
No full textAdult attachment style and caregiving attitudes were examined in two studies using a parenting simulation. In Study 1, 172 students completed measures of attachment and desire to become a parent before and after raising a virtual child. Measures of positive caregiver attitudes of serving as an attachment figure, perceived child security, and positive feelings were completed afterwards. Avoidance negatively predicted attachment figure and security measures, but not feelings. Desire to have children did not change due to the simulation, but was positively related to attitudes and negatively related to avoidance. Study 2 of 420 students showed that avoidance negatively predicted all three caregiver attitudes. Also, attachment was broken down into the four figures of mother, father, partner, and best friend. Anxiety towards mother and avoidance towards father negatively predicted security, and avoidance towards all but father negatively predicted attachment figure. These results showed the relation of avoidance to negative caregiver attitudes even in a parenting simulation when the child is not real
A narrative analysis exploring the significance of social support networks for youth experiencing homelessness in rural Nova Scotia
No full textOften the number of youth experiencing homelessness is not as clear in small towns, where shelters and services might not be as available as urban areas. This thesis explores the topic of homelessness in the context of rural Nova Scotia, focusing specifically on how a rural setting influences the services available for youth facing homelessness. This research looks to explore youths' perspectives through a narrative case study, exploring how these youth access the services that are available to them, and examine the networks that facilitate collaboration between these supports. The method used in this research is semi-structured interviews with youth, to hear their stories and experiences navigating services and supports in the area to understand the role that these networks play in their transition from homelessness. The findings highlight the need for this collaborative system to connect youth to various resources and services in rural areas. The data also presents the limitations of such services in addressing all of the complex issues that these youth experience, and points to structural causes of youth homelessness and the governmental role in social reproduction. This thesis presents the outcome of gaps in the neoliberal approach to social welfare in Canada and argues that these social service provisions fill the role of social reproduction through helping to facilitate social capital through their outreach and connection, and that these systems of support play a key role in youth transitioning into adulthood
Design and application of optical spectroscopy and imaging systems for the study of materials
No full textTwo experimental setups were designed and used to study a wide variety of materials. The first setup consisted of an automated excitation spectrometer to record emission and excitation spectra. The second setup was an automated two-dimensional scanner that used a fiber-optic cable along with a spectrometer to record a spectrum at every pixel across the surface of a sample. For each experiment, a specific set of LabVIEW programs were designed to acquire, characterize and analyze the data. Applications of the two experimental setups and LabVIEW programs included the investigation of the changes in the absorption spectra obtained from rat brain slices due to living vs. dead cells in the tissue, changes in the open-circuit potential produced at various locations on a solar cell, the transmittance of paint at different wavelengths and the luminescence
of different coloured Crayons. The rat brain slices did not show any changes in the absorption spectra because of the life state of the cells, but only the magnitude of the average absorption changed when there were changes in the thickness of the rat brain slice. A two-dimensional map of solar cell open-circuit potential was measured, and it was observed to be less efficient at producing a potential at the grain boundaries where the magnitude of the potential dropped in agreement with values from simulations presented in the literature. The transmittance of paint increased as the wavelength increased at least up to 1700 nm for all eight colours of paint investigated, thereby allowing pencil lead beneath the paint to be observed. The scanning spectroscopy setup was able to successfully record the luminescence signal from Crayons, which was an achievement due to the weakness of the signal compared to reflection or transmission experiments. In addition, a function was added to the LabVIEW acquisition program so that a plot of theemission spectrum for any pixel in the two-dimensional image could be viewed by clicking on the pixel; a very useful utility when creating image subsets from specific ranges of wavelengths or ratios of ranges of wavelengths. In summary, the research conducted resulted in a set of great tools that will aid design and analysis of similar experiments in the future
Analyzing visual attention and facial affect in response to adult attachment stimuli
No full textThis study seeks to explore how activating the attachment system leads to changes in implicit behavioral response that can be detected using modern biometric measures. The present study examined eye-tracking and facial affect coding responses to attachment-related stimuli from the Adult Attachment Projective Test (AAP). Participants (N=54) also completed questionnaires to determine their unique level of attachment anxiety and avoidance as well as depressive symptoms. Biometrics collected were average fixation duration, fixation rate per minute, average pupil dilation, blink rate (EBR), average blink duration, average distance
from the screen, average time spent looking at faces, average revisits to faces, facial expression response (joy, disgust, sadness, anger, contempt, surprise, fear) and facial expression valence (positive, negative). Most of the biometric measures showed no association with scores of attachment measures and depression. However, there was a significant negative correlation between EBR and attachment avoidance: participants who scored higher on avoidance blinked less when looking at the attachment stimuli. Previous research suggests two possible interpretations: 1) that EBR can be a proxy for dopamine levels in the brain (Jongkees & Colzato, 2016) and so avoidant participants find the AAP pictures less rewarding, and 2) that EBR is reduced during high cognitive load, and the avoidant participants have a higher cognitive load because they are
engaged in repressing their emotional expression while also creating their narratives. These findings suggest that stand-off measures of implicit response can provide information about attachment style, and that
EBR is a biometric measure that warrants further study
Use of eyespots for species identification in two cryptic skate species, Leucoraja erinacea and Leucoraja ocellata.
No full textTwo species of skates residing in the Minas Basin and Bay of Fundy, Little Skate, Leucoraja erinacea, and Winter Skate,
Leucoraja ocellata, share many morphological similarities, making them difficult to distinguish. This crypticism can cause fisheries bycatch records to be unreliable. As a result, the relative populations could be affected differentially if the species are managed or conserved as a complex. Many identification guides state Winter Skate grow larger and have eyespots whereas Little Skate are smaller and without eyespots. The study objective was to investigate differences between species
commonly used to distinguish them, but which past research has suggested is not reliable. Over 11,000 skates were caught in Avon Estuary, Scots Bay, or Bay of Fundy/Scotian Shelf, Nova Scotia, and 1349 were identified to species using genetics. A subset was measured for total length, weighed, and eyespots identified (presence/absence) and/or counted. The relationship of body size, eyespots, and capture location was modeled. We found the presence of eyespots in both species to be variable and no significant relationship existed between skate size and presence of eyespots. However, regional differences were shown, but only when pooling species (thus increasing sample size), suggesting eyespots may be environmentally driven. There was potential unintentional bias in skates selected for species identification which may preclude regional results
The Safe Third Country Agreement: a tool for securitization at Canada's southern border
No full textThe creation and implementation of the Safe Third Country Agreement (STCA) between Canada and the United States came as a response to the September 11 attacks that resulted in calls for increased border security. This thesis addresses one of the ways in which the increased level of security affects the safety of migration. I argue that the STCA securitizes Canada's southern border, further narrowing legal channels for asylum seekers to enter Canada. Through a discourse analysis, government documents and policy as well as news coverage are examined in order to understand the consequences of the STCA. By examining this through a securitization lens, I find that the Safe Third Country Agreement narrows the category of eligibility for asylum seekers and acts as a blanket ban on asylum claims from people who first land in the U.S. with a very small group of exceptions. This overarching agreement instead pushes people to enter Canada irregularly in order to access the Canadian asylum system. While the agreement focuses on each country effectively meeting its obligations to refugees according to international agreements, its implementation undermines these commitments. The emphasis on security of Canadian citizens puts the needs of asylum seekers themselves at the bottom of the list of government priorities and makes the refusal to address the inadequacies of the STCA a source of risk. Instead of focusing on new agreements addressing irregular migration, the Canadian government needs to address the inadequacies of the STCA. Without any solutions, the STCA will continue to perpetuate irregular migration and make migration from the U.S. to Canada between ports of entry dangerous to those who see it as their only option
An investigation of the excited-state dynamics of thiolate-protected gold nanoclusters and a method for evaluating the monodispersity of metal nanocluster solutions
No full textGold nanoclusters are an emerging class of materials that show great promise in a wide variety of analytical, catalytic, and biomedical applications due to their unique optical properties. They exhibit single-photon and multi-photon absorptions, fluorescence, as well as excellent catalytic reactivity. To achieve their full potential, specifically in catalysis, it is important to understand how size, geometry, and ligand choice influence their electrodynamics.
A series of gold nanoclusters of various sizes (Au18–Au144) were prepared with thiolate protecting ligands. Raman spectroscopy was attempted on the most stable species of the clusters, Au25 (SC2H4Ph) 18. However, no peaks attributable to the nanocluster were observed. Femptosecond transient absorption spectroscopy was performed on each of the synthesized clusters and the kinetics of the excited-state relaxation were investigated. The majority of phenylethanethiolate-protected clusters exhibited a two-step relaxation decay, while the glutathionate-protected clusters exhibited a three-step decay, demonstrating the ligand effects on the excited-state dynamics of gold nanoclusters.
Finally, parallel factor analysis was applied to excitation-emission matrices of binomial solutions of gold nanoclusters to develop a rapid technique to evaluate the monodispersity of nanocluster solutions. A qualitative, pass-fail, method of monodispersity evaluation was achieved, which could reduce the need for mass-spectrometry during cluster synthesis. The method also shows promise as a stand-alone evaluation of cluster solution monodispersity. However, more research is needed