English
Movement patterns, food availability, and fungal diets of sympatric flying squirrels in the Kawartha Highlands
Northern flying squirrels (NFS) are mycophagous specialists (fungi-dominated diet) thatmay be displaced with southern flying squirrel (SFS) range expansion, thereby limiting fungal dispersal in forest communities. To understand the implications of squirrel species turnover on mycophagy, we investigated the home ranges of both flying squirrel species who are living in stable sympatry. We found no significant difference in home range sizes and identified spatial overlap between the two species. Through habitat selection ratios we found SFS were strongly selecting for deciduous-dominated habitats more than NFS. Lastly, we conducted microscopy on flying squirrel scat and found NFS were eating more fungi than SFS. We conclude that the squirrels are sharing the same habitat landscape but are finding ways to partition the habitat accordingly to allow for sympatry. SFS may contribute to the spore-dispersal cycle similarly to their northern counterpart through moderate fungus consumption and large home range sizes.
Author Keywords: diet, flying squirrels, Glaucomys, home range, mycophagy, sympatry
Within-Generation and Transgenerational Thermal Plasticity in Cold-Adapted Salmonids of the Genus Salvelinus
Climate change is a major conservation concern, especially for many cold-adapted species. The rate of warming due to climate change will likely outpace adaptive responses, and many populations will likely need to rely on phenotypic plasticity to cope with environmental warming. It is currently unclear whether plasticity in physiological responses to warming will be sufficient to offset the negative consequences of chronic environmental warming in ectotherms. I studied within-generation and transgenerational plasticity in two cold-adapted species of fishes, lake trout (Salvelinus namaycush) and brook trout (S. fontinalis), following temperature acclimation. Adults of both species were acclimated to either cold or warm temperatures and offspring were generated using a fully factorial breeding design, whereby the family thermal histories included crosses made within each temperature treatment and bidirectional crosses between temperatures. Offspring families were subdivided into two groups and acclimated to either warm or cold temperatures, so that offspring thermal experience matched or mismatched that of one or both parents. Offspring metabolic rate and critical thermal maximum during an acute thermal challenge were measured for both species. Limited transgenerational plasticity was detected in both species, but had a lesser effect than within-generationacclimation. In brook trout, the paternal contribution was greater than the maternal contribution. In lake trout, a mismatch in thermal acclimation, where the offspring were cold-acclimated but the parents warm-acclimated, resulted in elevated offspring metabolic rate without a corresponding increase in growth, suggesting that a mismatch in temperatures across generations could be detrimental to offspring. Using RNA-sequencing, transgenerational plasticity was linked to differential gene expression in the liver of lake trout offspring, in that genes were differentially expressed depending on the parental acclimation temperatures. Within-generation warm acclimation had the greatest effect on gene expression profile of offspring, with more genes differentially expressed under conditions of within-generation warm acclimation compared with transgenerational warm acclimation. Although it has been suggested that transgenerational plasticity may help to buffer the impact of warming due to climate change, my work implies that transgenerational plasticity, like within-generation plasticity, will be insufficient for these two species of cold-adapted salmonids to cope with climate change.
Author Keywords: Brook trout, Climate change, Lake trout, Phenotypic plasticity, Thermal tolerance, Transgenerational plasticity
Development of the Attitudes Toward Pharmacological Cognitive Enhancement Scale
Pharmacological cognitive enhancement is the use of prescription drugs to improve cognitive functioning in healthy individuals. Multiple ethical concerns have been raised by such use. The purpose of this project was to develop a reliable and valid measure to assess public attitudes about this issue. Participants were university students in Studies 1 (N = 465), 2 (N = 580) and 3 (N = 156). In Study 1 principal components analysis reduced the 90-item Attitudes Toward Pharmacological Cognitive Enhancement Scale to 42 items that loaded onto four components: Cheating/Unfairness, Motivation, Expected Benefits and Safety. Subscale scores differentiated users and nonusers. In Study 2 confirmatory factor analyses supported the model and statistically significant associations were found with related constructs such as attitudes toward performance-enhancing drugs, and prescription drug expectancies. In Study 3 test-retest reliability over a 3-week interval was above .70 for 3 of 4 subscales. Implications and future directions are discussed.
Author Keywords: attitudes, cognitive enhancement, nonmedical use of prescription drugs, scale development, smart drugs
Assessing Mercury and Methylmercury levels in the Wabigoon River with special attention on mercury methylation
The Wabigoon River is known for an historic mercury (Hg) pollution source, caused by a chlor-alkali facility operating in the 1960s. As legacy Hg contamination continues to cause serious adverse health effects to the local communities living in the Wabigoon River region, it is imperative to undertake additional research to understand the deposition and transport of historical mercury in this system and more importantly, its conversion into methylmercury (MMHg) which renders it bioavailable for ongoing bioaccumulation. The aim of this dissertation was to evaluate the transport and accumulation of Hg species by doing a spatial and temporal analysis of concentrations of mercury and methylmercury along the Wabigoon River, as well as assessing rates of methylation and demethylation, identifying areas of higher methylmercury production. Results show that locations downstream from the pollution source still show elevated mercury concentrations, with levels at least five times higher in water and up to 134 times higher in sediments compared to background levels. Among selected study sites, the Hydroelectric dam, the Wabigoon Rapids wetland and Clay Lake were identified to have high capacity for methylmercury production in the system, with notably Clay Lake presenting a higher potential for methylmercury accumulation due to the observed lower methylmercury demethylation rate. Furthermore, the impact of wetting and drying cycles on Hg methylation in riverbed and wetland locations within the Wabigoon River system was investigated through a laboratory simulation. Findings indicated increased susceptibility of riverbed locations to wetting and drying cycles.
Author Keywords: Demethylation, Mercury, Methylation, Methylmercury, Wabigoon River
The design of DNA-containing biomaterials for forensic science
Access to human blood for forensic research and training in bloodstain pattern analysis (BPA) can be difficult due to many ethical, safety and cost concerns. Mammalian blood alternatives can be sourced, especially from local and willing abattoirs, but some concerns remain, and the added difficulties of high variation and species-specific differences in cellular components pose other issues. Therefore, synthetic alternatives to human blood provide practical options for the BPA community. This thesis explores the use of alginate hydrogels as a base material for forensic blood substitute (FBS) development. Hydrogels are first explored as a suitable environment for DNA stability and functionality and compared to other polymer systems. The ability of DNA to remain intact while undergoing electrospray ionization (ESI) is also investigated. The FBS design focuses on mimicking the fluid properties and genetic capabilities of whole human blood – a material not developed in FBSs previously. ESI was used to develop microparticles (MPs) that serve as cellular components of human blood (the red blood cells – RBCs, and white blood cells – WBCs). The microparticles were ionically crosslinked using calcium to provide small MPs (RBCs) or covalently crosslinked with functional DNA to provide larger WBC-like functional particles. The integration of these novel MPs into alginate-based materials is optimized and their use in BPA scenarios is explored. The FBS is tested in BPA scenarios of dripping experiments, impact patterns, and the ability to extract and amplify the contained DNA. In addition, the stability (or shelf-life) of the FBS was also assessed. The FBS exhibited similar spreading ratios to blood and demonstrated feasibility in use for impact angle (a) determination and impact pattern creation. Importantly, the DNA contained within the FBS could be processed with analogous protocols used in DNA evidence processing, enhancing its applicability to BPA research and training.
Author Keywords: Alginate hydrogels, Bloodstain pattern analysis, Electrospray ionization, Forensic blood substitutes, Forensic materials, Synthetic DNA design
The effect of oncology camp on the psychosocial health of childhood cancer patients
Objectives/purpose: This study examined the psychosocial health (including resilience, hope, social functioning, mental wellbeing, and stress) of childhood cancer patients attending a recreational oncology camp (ROC).Methods: Childhood cancer patients enrolled for ROC participated in a survey on the first (T1) and last (T2) day of camp, and 3 months post-camp (T3). This survey included the: Child and Youth Resilience Measure (CYRM), Children's Hope Scale (CHS), Social Provisions Scale (SPS-5), and Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS). Afternoon saliva samples were collected at T1 and T2 to determine cortisol (ELISA). Results: CYRM, SPS-5, and SWEMWBS scores were high but did not differ between timepoints. CHS scores at T3 were lower compared to T1 and T2 (F=9.388, p=0.008). Salivary cortisol levels were within normal ranges. Conclusion/clinical implications: Childhood cancer patients have high levels of positive psychosocial variables and normal stress levels while attending ROC.
Author Keywords: cancer, children, hope, oncology camp, psychosocial health
Simulating Microwave Morphology Dependent Resonances in Aqueous Dimers and Trimers
Microwave resonances in isolated water-based spheres, dimers, and trimers are explored using simulations conducted with COMSOL Multiphysics. The study centers on morphology-dependent resonances (MDRs) and hotspot characteristics in cm-sized objects at microwave frequencies. Monomers subjected to microwave radiation exhibit four distinct resonant modes at specific sizes characterized by electric and magnetic field distributions which correspond to magnetic-dipolar, electric-dipolar, magnetic quadrupolar, and electric quadrupolar resonances, respectively. Dimer configurations reveal intriguing hotspot features, with axial hotspots emerging as a key resonant characteristic. The three fundamental dimer orientations dictate unique resonant behaviors, highlighting the sensitivity of hotspot intensity to orientation changes, but smooth and consistent trends during transitions between them. Investigations into trimer structures, as a more intricate geometry formed by interconnected dimers, reveal the subtle interactions of spheres in a trimer structure. Trimer hotspots largely reflect the sum of isolated dimer hotspot contributions, showcasing the energy conservation with no evidence of a newly formed hotpot. Our results, while arising as a consequence of the particularly high index of refraction of water at GHz frequencies, are generalizable to other length scales (such as nano-photonics), were materials with sufficiently high refractive index and transparency to be found.
Author Keywords: COMSOL simulations, Electromagnetic physics, Microwave frequencies, Morphology-dependent resonance, water-based objects
The ecological, evolutionary, and behavioural context of ultrasonic vocalizations in flying squirrels
Acoustic communication is vital for mediating interactions between individuals and their environment. From echolocating bats to isolated rodent pups, ultrasonic vocalizations are a useful mechanism for producing localized and cryptic acoustic signals. Flying squirrels have been demonstrated to produce almost exclusively ultrasonic calls which is rare in both squirrels and mammals, though the significance of this acoustic range is unknown. To investigate the context of ultrasonic calls in these gliding mammals, I created phylogenetic comparative analyses to compare ecological and morphological traits against call frequencies. I found that nocturnality, a trait entangled with gliding in squirrels, was related to higher-frequency calls. Furthermore, by comparing all gliding mammals and their non-gliding counterparts, I found that gliding mammals produce significantly higher frequencies than these relatives. This form of cryptic communication is likely used to avoid predation, which was further supported by behavioural experiments wherein flying squirrels used significantly higher frequencies when predation risk increased. While high frequency communication was used by most gliders, I found that ultraviolet-induced photoluminescence, another potential form of crypsis, was strongly associated with nocturnality, with half of the tested gliding mammals showing evidence of this unique colouration. While ultrasonic vocalizations are widespread in echolocating bats and echonavigating mammals, I did not find evidence to support echonavigation in flying squirrels. Instead, I found that ultrasonic vocalizations are used in a variety of social contexts and during solitary foraging and exploration. These combined results demonstrate the unique ecological and evolutionary pressures acting on small-bodied, nocturnal gliding taxa and the resulting cryptic behaviours and communication.
Author Keywords: communication, flying squirrels, gliding mammals, Sciuridae, ultrasound, ultraviolet-induced photoluminescence
"Bow Down, Bitches" How Beyoncé's Art Reflects and Contributes to the Notions of Sisterhood, Female Empowerment, and Intersectionality within the Framework of Black Feminist Thought
This thesis examines Beyoncé's art within the context of Black feminist thought, specifically focusing on how her work reflects and contributes to the themes of sisterhood, female empowerment, and intersectionality. A comprehensive analysis of her songs and performances will demonstrate how Beyoncé's art advocates for unity, female empowerment, particularly for Black women, and encourages sisterhood and support. The results reveal that Beyoncé's art serves as a powerful tool to challenge societal norms, address racial and gender inequalities, and advocate for justice, especially in the lives of Black women. Through her music and performances, Beyoncé has become a powerful example of using popular music as a medium for social change and cultural empowerment. This research highlights the significance of her contributions to the ongoing conversations surrounding race, gender, and socioeconomic factors, underlining the powerful influence of her art in encouraging a more inclusive society.
Author Keywords: Beyoncé, Black Feminist Thought, Female Empowerment, Gender inequalities, Intersectionality, Sisterhood
Et'sehch'i; The Traditional Dene Burial Practices
My research into Et'sehch'i, the Traditional Dene Burial Practices, is a comprehensive study into how smaller groups, clans, of our northern Dene understood and handled matters of funerals. The research focuses on the Dene community of Radelie Koe, Fort Good Hope in the Northwest Territories of Canada, my home community. In these Pre-Contact times, there weren't any of the modern tools we are now familiar with. The dead were interred on outdoor stages, raised platforms.
The most important part of Et'sehch'i involved the matriarch or another Elder of the clan hand-picking individual youths to help keep the Community together. They kept together as a group, going around together, cutting wood for people, hauling water or ice and generally reinstalling joy into the People's lives. Another form of these coming-of-age ceremonials involved young girls becoming women. The research involves the ways in which the Dene handled anything to do with major changes throughout our history. It was mandated by the Elders Council and Band Council of Fort Good Hope and followed a community protocol of respect for culturally sensitive material. These traditions, following ethical standards, account in good part for our survival from a time we call "When the World was New", from dinosaurs to today's computers.
Keywords: Dene Community, Burial Practice, Et'sehch'i, Ceremony, Funeral, Youth, Painting, Ceremonial Practice, Ways of Being
Author Keywords: Burial Practice, Ceremony, Dene Community, Et'sehch'i, Funeral, Painting