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Lake trout (Salvelinus namaycush) distribution and ancestry in the Canadian Maritimes, and a case study of critical habitat and origin in Sherbrooke Lake, Nova Scotia
No full textLake Trout (Salvelinus namaycush) in New Brunswick and Nova Scotia are an elusive and understudied species, and historical stocking makes it unclear if they are of post-glacial origin. A synthesis of historical naturalist writings and government fish stocking records suggest that Lake Trout are native to this region. Records of Lake Trout, in some lakes, precede the earliest stocking records that began in 1886. Historical documents indicate that Lake Trout were once more widely distributed than they are now, and many populations have likely been extirpated. Sherbrooke Lake in Lunenburg County, Nova Scotia, may contain a native population that was later stocked upon, and contains the only known breeding population of Lake Trout in Nova Scotia. To identify key habitat features of Lake Trout in the lake, acoustic telemetry was used to track the depth and temperature residency of 11 Lake Trout and bathymetric and water column measurements were taken. To determine if Lake Trout are a native species to Sherbrooke Lake, tissue samples of 25 individuals from the lake were used to compare genetic likeness to populations that had been stocked into the lake. During early spring and summer of 2022, Lake Trout in Sherbrooke Lake occupied a hypolimnetic residency. Suitable temperatures of 8.5 to 10 °C were only available in one of three deep basins of the lake. Thermal mixing of the epilimnion, because of Hurricane Fiona, caused the hypolimnion in the south basin to shrink, forcing adult Lake Trout to narrow their depth range for approximately one month. This reduced depth range comprises only ~0.5% of the total volume of Sherbrooke Lake. Genetic analysis concluded that these Lake Trout were the most genetically distinct population evaluated when compared to those from Ontario, Manitoba, New York, and Vermont. DNA results indicate that native, genetically distinct Lake Trout persist in Sherbrooke Lake.</p
The effect of proprioceptive neuromuscular facilitation on hip extension and running velocity in university athletes
No full textHip extension in running is a limiting factor in stride length, which can thereby influence force production and running velocity. There are many clinical techniques that work on the anterior soft tissues of the hip joint to increase range of motion (ROM) of hip extension. However, there has been little research investigating if this increase translates to an increase in hip extension and/or linear velocity during the running gait cycle. Through 3-dimensional motion capture technology, it is possible to perform detailed biomechanical analyses of the running gait cycle with both over-ground and treadmill running. This technology has allowed for investigation into the effect of different interventions on running mechanics and economy.The objectives of this study were to investigate the effects of Proprioceptive Neuromuscular Facilitation (PNF) stretching on passive and active hip extension as well as maximal running velocity. Data were collected using timing gates, a 3-dimensional marker-based motion capture system and an instrumented force measuring treadmill. Participants included 29 healthy male athletes between 18 and 25 years. Passive hip extension during the modified Thomas test, maximal hip extension and sagittal hip ROM while running at 50, 60, 70 and 80% of maximal sprint speed, and 50 m sprint time were compared before and after a three-week intervention program. The treatment intervention included PNF stretching of the rectus femoris, iliacus and psoas muscles three times a week while the control intervention consisted of a placebo treatment. Indoor 50 m sprint times, peak sagittal hip angles in the modified Thomas test position, peak sagittal hip angles during treadmill running, and sagittal hip ROM during treadmill running were analyzed for statistical differences due to treatment.There were no significant differences for the 50 m sprint trials or modified Thomas test trials. There were no significant differences for the peak hip extension angle at any running speed on either the dominant or non-dominant legs. There was a significant interaction effect found in the sagittal hip ROM trials on the non-dominant leg at 50% maximal sprint speed in the treatment group. At the remaining speeds, there were no interaction effects on either leg.There were no significant differences found in the sprint speed, modified Thomas test or peak hip extension trials. An interaction effect was found in the non-dominant leg at 50% sprint speed, but no other significant differences were found. Interestingly, the tendencies of the (nonsignificant) results for the sagittal hip ROM contradict the hypothesis by consistently decreasing over the treatment period. Previous literature would indicate that the intervention would be expected to increase the ROM. This opens the question of the impact of increasing passive extension on running kinematics and performance. Further research is warranted to determine how a long-term hip flexor stretching program can impact running gait kinematics and sprint speed.</p
Navigating the experiences of family caregivers of persons living with dementia in Nova Scotia: how technology can help
No full textIn Nova Scotia, many older adults are affected by dementia, leading to a growing need for care and support. However, due to limited availability and long waiting lists for nursing homes, many persons living with dementia are primarily cared for by family caregivers, typically family members. These caregivers often willingly take on this role, but it can be physically and psychologically demanding. These challenges can take a toll on the family caregivers’ well-being. Recognizing the increasing prevalence of technology in society, this study explores the potential of technology to assist and support family caregivers in their caregiving responsibilities. The objectives are to understand the experiences of family caregivers, explore the role of technology in supporting dementia care, and identify the most promising areas for future research on technology use in enhancing dementia caregiving. A qualitative research methodology involving interviews with 11 family caregivers was employed. The findings highlight the complex caregiving dynamics, the importance of social support, and the potential of technology in enhancing caregiving experiences. Technology use was reflected in the caregivers’ daily tasks and many of them used technology as coping mechanisms. While technology offers various advantages such as communication facilitation, information access, entertainment and social connectivity, its adoption and usage are influenced by individual preferences, technological literacy, and access limitations. This study concludes that technology can play a significant role in supporting family caregivers but should be tailored to their specific needs and circumstances in Nova Scotia.</p
"Getting to a place of change": media discourse and the failures of Canadian universal healthcare for Indigenous peoples, 2008-2020
No full textThis thesis explores the ways in which dominant discourse within Canadian news media influences the public’s perception of Indigenous health experiences. Applying principles of critical discourse analysis to two media events concerning the deaths of two Indigenous patients in Canadian emergency departments, this thesis reveals the ways in which the conversation around Indigenous experiences of healthcare has evolved over time. Language that was once used to silence voices, establish power dichotomies, and conceal manifestations of inequality has shifted in ways that lift Indigenous voices and have the potential to empower Indigenous communities. Healthcare organizations can apply the knowledge put forth by this research to incorporate elements of cultural safety and Indigenous healthcare practices into mainstream healthcare to work toward a truly fair and equitable system of healthcare in Canada.</p
How do mothers balance? Looking at mothers' experiences with triple burden
No full textThis study examines mothers' ideas about good motherhood and how the expectations of homelife, work life, and community engagement impact mothers’ mental well-being and stress levels. This research uses a quasi-mixed methods approach. A survey, which included open-ended and close-ended questions, was created by using LimeSurvey. Participants in the survey were recruited by sharing a poster on different social media platforms, such as Facebook, Instagram, and Nextdoor. Twenty-five mothers participated in this study with 40% from Canada and 60% from the United States. The results from the study show that mothers define good motherhood as being emotionally and physically present when spending time with their children. When looking at other aspects of homelife, most mothers share responsibilities in their homelife with a partner or a family member. When looking at work life, mothers struggled to balance work life and homelife and often reported that their work life spilled over into their homelife. Although mothers participated in community engagement, this was not their priority and was often squeezed between their work life and homelife responsibilities. This research shows the complexity when trying to balance expectations and raises the question of support for mothers who are balancing these three roles and their expectations.</p
Identification of compounds produced by male hairpencil glands of Corn Earworm Helicoverpa zea, and their role in male autodetection and female mate acceptance
No full textHeliothine moths are some of the world's most important agricultural pest species. Helicoverpa zea (Corn Earworm), and Heliothis virescens (Tobacco Budworm) cause billions in damage and control costs worldwide each year. Given their economic importance, sex pheromones of many species have been studied for development of management techniques such as trapping for population monitoring. The majority of pheromones identified and studied to date have been female-produced sex pheromones. Less emphasis has been placed on male sex pheromones, associated with abdominal hairpencil structures which often function in courtship or to attract females. Studying of male produced sex pheromones is as much as important as female sex pheromone to develop novel integrated pest management techniques. My study examines the composition, detection and behavioral role of male H. zea hairpencil compounds in male autodetection and in courtship. Comparative examination of the hairpencil blend composition of H. zea and H. virescens revealed subtle differences in pheromone blend composition produced by males of these species. Electrophysiological testing demonstrated broad antennal neuron response in both males and females of H. zea to nine key stimuli, with sexual dimorphism present in each species. Behavioral assays suggested that odors released by male hairpencils are important in mate acceptance by female H. zea and may play a role in mate choice and species isolation. Wind tunnel observations indicated that key H. zea hairpencil odors (hexadecanyl acetate, octadecanyl acetate) also function in mate competition, antagonizing responses of downwind conspecific males following a female sex pheromone plume, meaning that males use such compounds to repel competing conspecific males. This finding provides an insight on conspecific males' olfactory processing of a male sex pheromone, as well as a potential new prospect for managing H. zea pest populations
Towards a fully realized smartphone VANET system
No full textVehicle Ad-hoc NETworking (VANET) is a highly active field of research with hundreds of publications yearly and interest from major industry and government organizations. VANET technology has the potential to stop roadway accidents and save lives. However, despite the interest and benefits of this technology it has yet to be deployed in the real world. This is largely due to the prohibitive cost of retrofitting millions of vehicles with VANET hardware. In order to solve this problem of adoption, lower cost alternatives to custom hardware must be found. The ubiquitous smartphone is a potential alternative. However, the smartphone is not as powerful as
dedicated VANET hardware, and thus simulation and research must be done to determine its feasibility.
This thesis presents and develops the idea of the smartphone VANET in full as a solution to the hardware adoption problem in VANETs. It considers the advantages and drawbacks of a fully smartphone based VANET system over a traditional VANET. The SVANET idea is thought through and tested from all angles in order to assess the practicality and feasibility of the idea, with special concern to the technological weaknesses of the smartphone as a platform.
Having explored the concept of the SVANET fully, a suite of applications is developed specifically for the SVANET. The proposed system is implemented in a simulation setting and tested. Using specially designed simulations to provide for maximum realism, we conclusively show the feasibility of the system and its ability to improve road safety across multiple situations. Finally, we offer a conclusion and explore future research directions for this topic. By presenting a conclusive study of the SVANET concept, this thesis aims to fully understand if the SVANET can be a suitable replacement for the traditional VANET
Imaginaries of entanglement: moving climate refugees beyond the human
No full textClimate change policy works within a clear binary between that of the human and the nonhuman, where the human is placed at the center of climate change policy, at the expense of the nonhuman. By having an idealized version of the human, climate refugees can only be looked as human. This thesis explores the ways that nonhuman's are creative, and imaginative, with the purpose of illustrating how certain nonhumans should be looked at as climate refugees. The question that this thesis seeks to answer is, how can a flat ontology create new imaginaries with climate change policy, climate change itself, and in turn the climate refugee? I argue that with a flat ontology different forms of entanglements between the human and nonhumans can be imagined. Object Oriented Ontology, Actor Network Theory, and New Materialism all reimagine the nonhuman, and help to rethink the climate refugee by recognizing the agency of the nonhuman. This thesis demonstrates the importance of language to the project of the more-than-human climate refugee, as language is not solely a human experience. There are many stories and imaginaries that are told through the nonhuman, and each should be listened to. The idea of kinship is important to this thesis, along with the apocalypse. They each illustrate, different imaginaries that exist through the entanglement of the human and nonhuman. The world is never just one world it is not just a human story. This thesis explores the many stories that could and do exist, starting with the more-than-human climate refugee
American lobster Homarus americanus demographics related to depth and temperature in lobster fishing areas 33 and 34 off Nova Scotia
No full textThe lobster fishery is the most valuable fishery in Canada, representing over 40% of total seafood landings, with most landings in lobster fishing areas (LFAs) 33 and 34 off Nova Scotia. Canadian lobster landings have been steadily increasing since the 1980s and are projected to continue to increase due to fewer predators and expanding suitable habitat. Within LFAs, lobster are caught up to 90 km from shore. Differences in morphological characteristics between inshore and offshore contingents (if they exist) remain poorly identified and characterized. This study characterized lobster morphometrics, population structure, and other metrics of population status in relation to habitat characteristics of depth and temperature in LFAs 33 and 34 to determine if lobster contingents exist and if so, their relationships to local habitats. Overall, relationships were apparent between lobster morphometrics and environmental factors including depth, bottom temperature, surface temperature, month, soak time, latitude, longitude, and between the lobster morphometrics and lobster condition, sex, carapace hardness, and carapace length. Most environmental variables were collinear, obscuring any significant relationships in all models. Furthermore, deviance explained was low for all GAMs and misclassification rates were high for nearly all multinomial logistic regressions, demonstrating that the models were able to account for little variability in the data. Our results were generally comparable to other studies with a few discrepancies. In conclusion, eliminating the collinearity between variables and recording video footage of lobster at depth would allow us to strengthen our analyses and consider potential differences in lobster behaviour. We did not determine if local contingents exist in the inshore and offshore regions of LFAs 33 and 34 because generalizing habitats to inshore and offshore regions fails to capture habitat characteristics at finer scales of resolution that may affect lobster distributions.</p
Fungal endophytes from apple (Malus domestica) roots as biological control agents of apple replant disease
No full textWhen new young apple trees (Malus domestica) are planted in an orchard soil that was previously used to grow apples or related plant species, young trees can experience Apple Replant Disease (ARD). ARD results in root necrosis, reduction in plant growth and vigour, as well as reduced fruit yield and delayed fruit bearing, all of which harm growers’ return. Conventionally, chemical fumigants have been used to disinfect soil between plantings as a treatment for ARD, but the deregistration of harmful, chemical fumigants due to environmental and public health concerns has created a demand for eco-friendly alternative treatments. I explored fungal endophytes from healthy, mature apple roots as potential biocontrol agents to treat ARD and reduce the need for chemical fumigants.48 fungal endophytes were isolated from apple root and tested in dual culture competition assays for antagonistic activity against Pythium ultimum and Rhizoctonia solani; two pathogens associated with ARD. In dual culture competition assays, all endophytes were able to inhibit pathogens to some extent and different types of endophyte-pathogen interactions were observed. From the results of these assays, five biocontrol candidates were selected for further investigation, including two Trichoderma species, a Talaromyces sp., a Mortierella sp. and a Gongronella sp. The cell-free culture filtrates and extracts of these five biocontrol candidates were tested for antagonistic activity against ARD pathogens and for broad-spectrum antimicrobial activity. These five biocontrol candidates were also tested for phosphate solubilization ability, optimal growth temperature, fungicide tolerance, and initial growth promotion and anti-ARD trials were performed with apple rootstocks in the greenhouse.The cell-free culture filtrate from liquid cultures of five selected biocontrol endophytes demonstrated a range of inhibition potential against four ARD pathogens, with an endophyte identified as Mortierella NS-01 inhibiting all four pathogens to the greatest extent. We can infer that the antagonistic activity demonstrated in the dual culture assays of the isolates with antimicrobial culture filtrates was likely due to secreted non-volatile compounds and could occur independently of direct contact. Further studies could seek to identify specific antimicrobial molecules and test them in a similar assay. Conversely, ethyl acetate extracts did not generally support the results of the culture filtrate assays, perhaps due to antimicrobial molecules that were not extractable by ethyl acetate. Endophyte culture filtrates also demonstrated a range of inhibition against bacteria, yeast and fungi in liquid culture. Trichoderma isolates were tolerant to tested fungicides, whereas Talaromyces NS-01 showed sensitivity. Generally, the fungal endophytes grew optimally between 20-30℃. In vivo, inoculation of Talaromyces NS-01 and Mortierella NS-01 in combination resulted in a greater apple rootstock height in comparison to controls, indicating potential growth promoting effects. In ARD soil, there was generally not a statistically significant difference in size of inoculated apple plants compared to uninoculated after 8 weeks. Even so, in G202 rootstock, there tended to be an increase in size in inoculated plants in ARD soil, although the reverse was observed in M26 rootstock, and neither of these effects was statistically significant. Some of these inconsistencies could be addressed by developing a protocol that optimizes colonization of the apple roots.In conclusion, five biocontrol candidates were selected and particularly, Trichoderma NS-01, Trichoderma NS-02, Talaromyces NS-01 and Mortierella NS-01 inhibited ARD pathogens through secreted molecules. No clear conclusions were made on the potential for endophyte inoculations to work against ARD in vivo, although Talaromyces NS-01 and Mortierella NS-01 in combination have demonstrated growth promotion in non-ARD conditions.</p