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Investigating the reproductive ecology of two native New Brunswick plants (Halenia deflexa and Lysimachia terrestris)
Full text linkThe reproductive biology of native New Brunswick plants Halenia deflexa and Lysimachia terrestris are of interest as they are underrepresented in scientific literature and this research will inform our understanding of these angiosperms. While it is known that H. deflexa is self-compatible, it is unclear how its selfcompatibility effects its offspring. As well, the self-compatibility status of L. terrestris is currently unknown. This study aims to address these gaps in knowledge. To determine relative seed quality, 223 self- and outcross pollinated H. deflexa seeds were weighed. It was found that there was a borderline
insignificant difference in mean seed mass between the two pollination treatments and a trend towards lower mass seeds in self-pollinated seeds. This suggests that self-pollinated seeds may be of lower quality. To determine the self-compatibility status in L. terrestris, 31 plants at the Sackville Retention Pond were emasculated and hand-pollinated with self or outcross pollen. While the self- and outcross pollination fruit sets were not statistically different, the results suggest that L. terrestris is self-incompatible. Additionally, the self-compatibility study prompted an investigation into L. terrestris sexual and asexual reproductive traits which revealed that there is spatial structure in the Sackville Retention Pond population.
Overall, there are many aspects of H. deflexa and L. terrestris reproductive biology that we do not understand, but our research has shown that self-pollinated H. deflexa seeds may be of lower quality and that L. terrestris may be selfincompatible. Future studies should investigate the magnitude of inbreeding
depression in self- and outcross pollinated H. deflexa, as well as potential causes for the spatial structure seen in L. terrestris reproductive traits
Optimization of sperm cryopreservation protocols for blue tilapia (Oreochromis aureus)
Full text linkConservation efforts are implemented worldwide in an attempt to mitigate the decline in biodiversity experienced today. As of 2021, over 3000 species of fish worldwide have been classified as critically endangered, endangered, or vulnerable. Primary contributors include climate change, pollution, habitat loss, overfishing, and invasive species. These issues are not being combated fast enough to save species from extinction. Thus, it is vital to develop complementary approaches to conserve biodiversity. An area of research under development is cryopreservation of fish sperm. Sperm cryopreservation provides an excellent method for species conservation by allowing for long-term storage of genetic material without risk of deterioration; therefore, providing a safeguard against species collapse. Unfortunately, cryopreservation is difficult to standardize across fish species due to its physiological complexity as well as biological differences of spermatozoa across species that influence their tolerance to the freeze/thaw process. Thus, species-specific methods must be developed. Blue tilapia (Oreochromis aureus) are of particular interest due to their importance as a food source for humans, excellent adaptability to being in culture, they are easy to breed, reproduce quickly, and tolerate high stocking densities. However, there is limited research on the cryopreservation of blue tilapia sperm, as the focus often lies on Nile and Mozambique tilapia. Therefore, I investigated an optimized cryopreservation protocol for blue tilapia
sperm by testing combinations of three different cryoprotectants: dimethyl sulfoxide (DMSO), methanol (MeOH), and glycerol (Gly), with three different slow cooling rates: -1°C/min, -5°C/min, and -10°C/min. After thawing, viability of the protocols was assessed through spermatozoa motility and swimming kinematics as well as cell membrane damage using Trypan Blue membrane stain and a lactate dehydrogenase (LDH) enzyme assay on seminal plasma. Results indicate that DMSO at -5°C/min yielded consistently better outcomes than other treatments, however, due to limited overall success, further investigation is required to achieve the most effective protocol. Finally, percent motility analysis and Trypan Blue staining provided the most reliable results while LDH activity and swimming kinematics were less conclusive as viability measures
Visuo-haptic memory representation and the influence of verbal processing
Full text linkRecent research suggests that there is a verbal component to the shared visual-haptic memory representation. The current study examined the nature of visual-haptic memory representations among 45 undergraduate participants. Participants saw novel objects in one modality (visual or haptic) and then were presented with another object in a different modality and were asked to determine if the two objects were the same or not. Some participants completed the task with no distractor, while others completed a visual distractor task, and others did a verbal distractor task. The distractor tasks did not affect the performance of participants, and this finding did not support my hypothesis that there is a verbal code for the visual-haptic memory representation. I also observed that participants responded faster for incongruent trials and when haptic examination of the stimulus occurred first. Moreover, there was a significant difference in errors for congruence when visual examination occurred first. This pattern of findings suggests that there is a dominant visual process involved in visual-haptic memory representation
Court vision: An attentional advantage of competitive athletes
Full text linkUniversity athletes spend a considerable amount of time immersed in their sport environment which offers an attentional advantage over non-athletes in a sports environment. To test this, university basketball and soccer players, and non-athletes were shown photographs of basketball, soccer, and non-sports contexts using a change detection paradigm. Across repeated presentations of a photograph, participants were tasked with detecting which object was changing. It was hypothesized that athletes would be more efficient at detecting changes to sports contexts than non-athletes. Further, it was predicted that basketball players would produce the most efficient performance for basketball images and soccer players would produce the most efficient performance for soccer images (i.e., a sport-specific attentional advantage). In a second part of the experiment, the same images were presented inverted. It was predicted that inverting the images would disrupt any expertise related attentional advantage. Contrary to the predictions, basketball players were slowest to detect changes to basketball images but made the fewest errors for these images. The speed difference was eliminated when the images were inverted, but the basketball players continued to show an accuracy advantage across image type
A critical policy analysis of Raise the Bar as the most recent neoliberal education return rollout in Nova Scotia
No full textThis thesis is a critical policy analysis examining a public education administrative review in Nova Scotia, Canada by Dr. Avis Glaze. Twenty-two recommendations for improving student performance and educational outcomes were outlined in the official document, Raise the Bar. Dr. Glaze’s recommendations were rooted in efficiency, austerity, and improving accountability. Soon after, Nova Scotia passed the Education Reform Act, officially adopting almost all of the recommendations Dr. Glaze provided. Many sweeping changes to education and administration have resulted, such as the removal of school boards. During the implementation of Dr. Glaze’s recommendations, the impacts on equitable education outcomes have been felt across many stakeholders including teachers and students. This analysis considers the conditions that led to Dr. Glaze’s review to assess if equitable education outcomes are achievable now, four years after Raise the Bar. Examining who benefits from education reform rollouts (and why), this thesis argues that changes to education are necessary for equitable educational outcomes but cannot be
meaningfully implemented as a neoliberal project
The effect of nitric oxide on endocannibinoid signalling at glutamate synapses in the rat dorsomedial hypothalamus
Full text linkEndocannabinoids (eCBs) and nitric oxide (NO) are both retrograde neurotransmitters that are made in the postsynaptic cell in response to increases in intracellular calcium. eCBs target type I cannabinoid receptors (CB1Rs), located on the presynaptic membrane, while NO binds soluble guanylate cyclase (sGC) inside the presynaptic cell. Both neurotransmitters can act presynaptically to regulate GABA and glutamate transmission. Previous studies have shown an interaction between NO and eCB signaling. NO prevented eCB-mediated decrease in glutamate transmission in the dorsomedial nucleus of the hypothalamus (DMH). Furthermore, another study within the DMH found that NO was required for eCB-mediated decrease in GABA transmission. There is little research, however, on the mechanism behind the interactions between eCBs and NO. The DMH has been a major focus for research due to its importance in appetite regulation. We aimed to determine how NO affects eCB signaling at glutamatergic synapses in the rat DMH. We hypothesized that NO affects eCB-mediated decrease in glutamate transmission through an NMDA, and cGMP, -dependent pathway. To test our hypothesis, male Sprague Dawley rats were used as subjects, and whole-cell electrophysiological recordings were taken at glutamate synapses in live DMH neurons. Our results show that NO disrupts eCB-mediated depression through an NMDA receptor-dependent pathway. Additionally, we further targeted the NO pathway and concluded that NO is likely affecting eCB signaling from the postsynaptic cell. We also performed an experiment targeting CB1R activation by an agonist. Previous data showed that activation of CB1Rs by an agonist significantly decreased glutamate release. We repeated this experiment in the presence of L-arginine, a NO precursor, and observed that the agonist was still able to decrease glutamate signaling. Finally, we wanted to determine if NO is affecting short-term eCB signaling. Previous research has suggested that NO does not affect short-term synaptic plasticity at glutamate synapses in the hippocampus. Our data was consistent with this as we did not see a change in short-term glutamate transmission. Overall, figuring out how these two retrograde neurotransmitters interact to affect synaptic transmission can extend well beyond appetite regulation as these neurotransmitters are ubiquitously produced at synapses in various parts of the brain
Bridging traditional ecological knowledge and Western scientific knowledge in co-management initiatives in Canada
Full text linkClimate change is an imminent and increasing threat to humanity. As a response to
various environmental issues, there has been a surge in co-management initiatives that bridge
Traditional Ecological Knowledge and Western scientific knowledge. It is known that Western
science alone cannot solve various issues stemming from climate change, but when it is
equitably bridged with Traditional Ecological Knowledge there is the possibility to address these
challenges. This paper aims to determine whether co-management is effective for solving
complex environmental issues. Specifically, it assesses whether it is possible to equitably bridge
Traditional Ecological Knowledge and Western scientific knowledge in co-management
arrangements. To assess the successes and challenges of bridging knowledge systems in comanagement
initiatives, this paper consists of a literature review of co-management in Canada
along with three case studies with interviews from academics who have been involved in the
respective case studies. The case studies exemplify many challenges associated with equitably
bridging Traditional Ecological Knowledge and Western scientific knowledge in co-management
initiatives, notably how there is a hierarchy of knowledge where Western science is favoured,
issues of mistrust, and ultimately, an undervaluing of the importance of Traditional Ecological
Knowledge. The case studies demonstrate the successes of these co-management initiatives,
although there is arguably more work that needs to be done to equitably bridge these knowledge
systems, such as through a Two-Eyed Seeing approach. Overall, co-management and equitable
knowledge bridging has the potential to tackle complex environmental issues while also bringing
Indigenous voices and knowledges to the environmental discourse, which have been historically
ignored and devalued through colonial systems and policies
The A2 active target time projection chamber
Full text linkThe A2 Collaboration uses the Mainz Microtron to conduct measurements probing hadron structure. An upcoming experiment will study Compton scattering off 3He to obtain the polarizabilties of the neutron. To identify this reaction, the detection of the low-energetic recoil particles is necessary. This is not possible with the current equipment, and so an active target is required. A compact Time Projection Chamber (TPC) is being constructed for this purpose, to be used in combination with the existing photon calorimeters.
The main goal of this work was to create a Geant4 simulation of the active target TPC. A signi cant limitation to the Geant4 software was discovered, but was overcome by the creation of a custom electron drift model. With the Geant4 simulation, it was possible to create an event reconstruction framework, and then study the functionality of the active target. The active target TPC is a new technological approach for A2, and so it is not without its challenges. This work revealed kinematic limitations to the proposed experiment. Various solutions are explored, providing essential input for the design of the active target TPC electronics and the Compton scattering on 3He experiment
Exploring the unique contributions of self-compassion and growth mindsets in academic success
Full text linkSelf-compassion is associated with positive mental health and emotional wellbeing, whereas growth mindsets contribute to behaviours that promote self-improvement. Given the limited research on these constructs within the academic context, the purpose of this study was to examine the relative contributions of self-compassion and growth mindsets towards outcomes of academic success. A sample of 175 undergraduates completed an online survey measuring self-compassion, growth mindsets, self-esteem,
and academic outcomes including satisfaction, commitment, confidence, and effort. Correlations and results from multiple regression analyses provided mixed support for the hypotheses. First, self-compassion predicted emotional academic outcomes but failed to do so when controlling for self-esteem. Contrary to expectations, growth mindsets did not contribute to the prediction of behavioural academic outcomes. Finally, exploratory analyses suggest a benefit to matching predictors and outcomes in terms of specificity. These findings suggest that self-esteem may matter more in this context because of the evaluative nature of the academic setting. Given the limitations associated with the present study, future research should continue to examine the potential benefits of self-compassion and growth mindsets for undergraduates
Multi-strain analysis reveals distinct light and temperature growth optima for morphology similar cyanobacteria
No full textPicocyanobacteria are small cyanoprokaryotes (0.2-3 μm) that play a large role in global primary production. Given the effects of climate change, picocyanobacterial distribution and localized growth rates may produce overgrowth that can cause negative effects on global biogeochemical cycles and food webs. In this study, we developed a matrix of three light conditions and four ecologically relevant temperature conditions to test the growth rates of six diverse strains of picocyanobacteria in order to predict how picocyanobacteria will grow as global water temperatures increase. Using modified Gompertz models and generalized additive modelling approaches, I uncovered a diverse range of growth optima for both cell count growth rates and chlorophyll growth rates that reveal a general preference for warmer temperatures. Given localized climate trends, we can predict that picocyanobacterial growth rates will increase as much as 40% within the coming century