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Carbon dioxide capture by amines: moving beyond sequestering
No full textIt is no secret that humans have contributed to an increased concentration of carbon dioxide in the atmosphere, intensifying the greenhouse effect and accelerating the pace of climate change. Reducing the amount of carbon dioxide released into the atmosphere is an important step in slowing down climate change and the environmental impacts people around the world are experiencing. Amines have shown high activity towards capturing carbon dioxide, however the carbon dioxide captured is often just released in a controlled manner or stored. This project investigates trapping carbon dioxide with amines followed by conversion into useful materials. The initial studies have focused on benzylamine, cyclohexylamine, tert-butylamine, diisopropylamine, and ethylenediamine. The resultant carbamates have shown varied degrees of thermal stability. The salts initially formed contain synthetically problematic ammonium cations for subsequent reactions and must be exchanged for inert cations by deprotonation reactions.</p
Toward an understanding of the loose bolt effect in 2-phenylphenol
No full textExcited state intramolecular proton transfer (ESIPT) reactions are photochemical reactions that occur in many phenols and are what allows many phenols to be used as sunscreens and photo stabilizers. 2-Phenylphenol and 2,6-dihydroxybiphenyl exhibit ESIPT to aromatic carbon with quantum yields of 0.08 and 0.22, respectively. Ortho alkylation of these molecules has a mixed effect on ESIPT quantum yield which is thought to be due to the alkyl group’s steric effect on the phenolic hydrogen as well as its accelerating effect on the rate of internal conversion from the singlet excited state. To better understand the effect of alkyl substitution on ESIPT quantum yields, derivatives substituted para to OH (Me, tBu) of 2-phenylphenol were synthesized by Suzuki coupling of suitable precursors. The photochemistry of the biaryl phenols was studied using product studies.2-Phenyl-4-methylphenol and 2-phenyl-4-tert-butylphenol were synthesised with yields after purification by column chromatography of 15% and 22% respectively. Products were characterised by 1H and 13C NMR spectroscopy. Optimal conditions for aqueous Suzuki coupling of bromophenols to phenyl boronic acid were found. Compounds were shown to undergo ESIPT but quantum yields were not measured due to poor quality MS data.</p
An investigation of chromium and strontium sources in MacAskill Brook Watershed and MacAskill Reservoir, Nova Scotia, Canada: implications for watershed and reservoir management
No full textThis thesis details an integrated paleolimnological—groundwater—soils study in northeastern Cape Breton focussed on identifying the sources of chromium (Cr) and strontium (Sr) within the watershed surrounding a reservoir. The sources of these metals and their pathway into the water in the reservoir is of interest because both metals present a management challenge. The sludge produced as a waste product of water treatment contains elevated Cr, which is an environmental concern and a significant treatment expense. The introduction of freshwater mussels is being considered as a treatment for elevated water colour and because shellfish are known to bioaccumulate Sr. An understanding of the source(s) of Sr is required to determine the environmental implications of this strategy.MacAskill Reservoir is a constructed 329 ha reservoir that drains a 3763 ha watershed and is a potable water source for about 24 000 people. The reservoir watershed is underlain by Carboniferous strata and has been the focus of extensive underground coal mining and surface processing; both coal and marine sediments are considered significant geogenic Sr and potential Cr sources. The overlying glacial till and related soils were generated in part from nearby marine-derived sedimentary strata (sources of Cr and Sr) and nearby ultramafic deposits (source of Cr). Anthropogenic activities in the region (junkyards, coal-powered generation stations, agricultural fields and fertilizers) must also be considered as possible sources of Cr and Sr. To provide as comprehensive an assessment as possible, surface water, groundwater, soils, and paleolimnological samples from a nearby lake and the reservoir were assessed.This study determined that Cr is most prevalent in watershed soils and that Sr appears in the highest concentrations in groundwater. Glacial till underlying the watershed appears to be the primary source of both metals, though local bedrock may also contribute to elevated Sr in water samples. Paleolimnological data indicates that Sr and Cr were probably not transported atmospherically to the site in detectable concentrations. Due to the acidic water and soil in the area, the Cr is reduced in the soil as the stable Cr(III) rather than mobilized in the water column as the more toxic Cr(VI). Cr in the soil is suspected to be elevated because of the glacial till transported from the Boisdale Hills, where mine tailings indicate concentrations greater than 440 mg/kg. Elevated Sr in groundwater is associated with chemical sedimentary rocks in the watershed, particularly the coal-bearing measures that have been mined extensively.The risk of Cr and Sr release into surface and groundwater systems and subsequently into the reservoir can be reduced by limiting landscape disturbances, particularly the wetlands located on the northwestern side of the watershed. Legacy coal workings also have significant potential to release Cr and Sr into water systems and require further assessment and monitoring to better understand the risk. As well, long-term monitoring of the watercourse and reservoir limnology may help determine how seasonality impacts Cr and Sr release into the reservoir.</p
Unveiling the world of dreams: differences between autistic and allistic individuals
No full textThe purpose of this study was to examine the differences in dream content and structure between autistic and allistic individuals. Participants (N = 158) completed an online questionnaire, which included demographic questions, the Autism Quotient-10 (AQ-10), the Mannheim Dream Questionnaire (MADRE), and the Dream Insight questionnaire (DRI). Participants were also asked to provide a report of their most recent dream. It was found that while there was a significant association between Diagnostic Category (i.e., autistic or allistic) and the number of Dream Characters (p = .01), however, this was the inverse of what was hypothesized as there were more Dream Characters present rather than fewer. While Diagnostic Criteria did not significantly predict the number of Social Interactions, one of the covariates, Sexuality was significantly associated with the number of Social Interactions (p = 0.002). This indicates that there may be some differences in the dream content and structure of those who are autistic when compared to allistic people.Keywords: dreaming, ASD; autism, dream structure, dream content</p
Preliminary exploration of symptoms of depression, anxiety, and fatigue in stroke patients with and without spatial neglect
No full textStrokes are neurological events resulting from a disruption of cerebral blood flow, which can lead to a wide range of impairments in survivors, including cognitive deficits, psychiatric symptoms, and chronic fatigue. Despite the significant impact of these conditions, the interaction between cognitive syndromes, such as spatial neglect, and post-stroke psychiatric symptoms or fatigue remains underexplored. This gap highlights the need for further research to understand these relationships and improve long-term rehabilitation strategies. The current pilot study explored symptoms of post-stroke anxiety (PSA), post-stroke depression (PSD), and post-stroke fatigue (PSF) in a small sample of right-hemisphere stroke patients, who were screened for participation in a spatial neglect therapy protocol. This study compared those with and without neglect, hypothesizing that neglect would be associated with higher levels of symptoms of PSA, PSD, and PSF, given its link to more more severe functional impairment and poorer rehabilitation outcomes, potentially exacerbating psychological distress. Fisher’s Exact Tests were used to compare symptoms and diagnoses of PSA, PSD, and PSF between groups. While no differences were statistically significant, likely due to small sample size and demographic variation, preliminary trends based on effect sizes suggested a positive association between neglect and depression, and an unexpected negative association between neglect and anxiety. A case illustration is presented, detailing the data over time from one participant who completed the therapy protocol. The ongoing study aims to collect additional data to more robustly examine these relationships, with the ultimate goal of informing integrated rehabilitation strategies and improving patient outcomes.Keywords: spatial neglect, post-stroke anxiety, post-stroke depression, post-stroke fatigue</p
Enhanced incubation: using day-time video to enhance incorporation of nighttime dream cues and lucid dreaming
No full textLucid dreaming and dream engineering are getting closer to becoming a reality because of technological developments that allows for real-time sleep staging, e.g., the advent of wearables. In the current pilot study, we used an iPhone application called DreamDirector, which is an iPhone app that connects to the Apple Watch and can detect Rapid Eye Movement (REM) sleep in real-time and provide different types of sound, vibration and light cues during REM sleep to influence dream content. We conducted the study on the sleep of 28 individuals for 25 nights divided into 4 different phases. The current study is Phase 3 of this study. Participants viewed an AI-generated video that resembled a dream vacation. The participants watched the video an increasing number of times (0, 1 time, 5 times, and 10 times) over 4 days during the day. Our aim was to test if external stimuli presented during the day can influence dream content and the incorporation of related cues played back during the night using the DreamDirector app for cue presentation. We found that enhanced incubation using daytime video paired with audio stimuli at night during REM sleep did not increase the likelihood that participants recalled dreams related to the incubated subject matter.Keywords: Lucid dreaming, Apple Watch, Enhanced Incubation, AI video</p
Investigating whether cross-caregiver reports of parenting improve predictions of children's mental health outcomes
No full textRecent data indicate ongoing increases in the number of youths reporting mental health difficulties. Early caregiving behaviours are known to predict early emerging internalizing (e.g., anxiety, depression) and externalizing (e.g., aggression, hyperactivity) symptoms, which can impact children’s social and behavioural functioning across the lifespan. While accurate assessments of parenting styles are essential for identifying youths’ risk for negative outcomes, commonly used caregiver self-report methods may reflect caregivers’ own biases about their caregiving behaviours. Cross-caregiver reports may provide additional context to caregiving behaviours and help to predict children’s symptoms more accurately, but research exploring their use is limited. My study examines whether incorporating cross-caregiver informant reports will improve models linking ineffective parenting styles to children’s mental health symptoms. I observed consistent associations between mothers’ reports of their own and their partners caregiving and child behaviour outcomes, and less consistent associations between fathers’ reports of caregiving behaviours and children’s outcomes, potentially reflecting differences in caregiving roles or involvement. My findings suggest that collecting self- and informant-reports of caregiving practices from a primary caregiver may help to develop more efficient procedures that are minimally burdensome to participating families.Keywords: parenting styles, cross-caregiver reports, children, mental health</p
Exploring how cannabis consumption influences episodic future thought and prosocial behaviour
No full textEpisodic memory is the ability to recall details of past personal experiences, while episodic future thought is mentally constructing novel events using these memories. Notably, these mechanisms share similar neurocognitive pathways and are integral for executing behaviors in daily life. Individuals with established memory issues, such as amnesiac patients or older adults, display disruptions in future thought. Recent research has used a phenomenon known as the prosocial simulation effect to examine future thinking abilities in those with memory deficits. In this effect, imagining scenarios of helping a person in need increases the likelihood of helping others. To date, little research has examined whether the established issues found in those who use memory-altering substances (e.g., alcohol or cannabis) also translates to future thinking deficits. As such, the present study investigates whether cannabis use affects episodic future thought by examining the prosocial simulation effect in cannabis users and non-users. Participants read one-sentence stories about people in need and were assigned to either an imagine helping or control condition. Both cannabis users and non-users exhibited the prosocial simulation effect, with higher willingness to help ratings in the imagine helping condition. While non-users also showed an expected increase in scene vividness ratings after imagining future helping scenarios, cannabis users’ scene vividness ratings did not differ between conditions. These findings suggest that while cannabis use does not diminish the prosocial simulation effect, it may impair episodic construction of future scenes. These findings have implications for whether cannabis use may also impact other future thinking mechanisms.Keywords: cannabis, episodic future thought, memory, prosociality, prosocial simulation effect</p
Real-time REM sleep stage classification using deep convolutional neural networks
No full textWe provide a comparative study of convolutional, recurrent, and transformer neural networks for the classification of REM sleep stages in real-time using data from a commercially available smartwatch. We have developed software for the iPhone and Apple Watch that enables real-time sensor data collection. This information is used twofold: (1) it is stored for the development and evaluation of the neural network models, (2) it is used as input to an embedded model in an iPhone app which classifies the current sleep stage in real time. Heart rate and acceleration measures are collected and consolidated into 2-minute intervals, for input to the model. Ground truth data has been gathered through Apple’s HealthKit dataset. We statistically showed that Apple’s HealthKit data was sufficiently close to the industry standard Cerebra Sleep Study System and more affordable, so going forward with our experiment, we stuck with HealthKit data for ground truth. We collaborated with the psychology department of Acadia University to conduct a sleep study with three different participants to collect data for our research. Earlier research using data from several subjects determined that the variability between person’s sleep patterns requires every person to have a customized model. To improve model performance, we used a 5-fold cross-validation to evaluate neural network architectures tailored to individual users. By integrating advanced features and incorporating Multi-Task Learning (MTL) techniques, we achieved significant improvements in real-time REM sleep detection, exceeding the benchmarks set by prior study. Our results indicate that the single-layer convolution model with batch normalization and a kernel size of 3 (CNNKernel3), as well as the single-layer convolution model with max-pooling, and kernel size of 9, had superior performance. The MTL CNNKernel3 model, derived from a single subject, scored an AUC of 0.901, correlation of 0.697, REM accuracy of 0.853, F1 score of 0.708, and TPR of 0.788 with a TNR of 0.881 on test datasets.</p
The menace of political vigilantism and the security of Ghana
No full textPolitical vigilantism appears to be supported by Ghana's developing political culture, as evidenced by the cyclical nature of vigilante group operations. The purpose of this thesis is to understand the risk political vigilantism poses to Ghana's security and how Ghanian officials securitized vigilantism. This thesis uses discourse analysis as a research methodology to analyze the construction of political vigilantism as threat posed to the security of Ghana through the lens of securitization. The research reveals that vigilantes in Ghana have established themselves as semi-autonomous organizations that pose a threat to the legitimacy of the state given their history of physically assaulting and forcibly removing government officials from office. Political vigilantism in Ghana is primarily caused by youth unemployment. The youth are vulnerable to the manipulations of the political elites because of Ghana’s high youth unemployment rate. Low trust in government institutions and security services, including the Electoral Commission of Ghana and the Ghana Police Service pushes the youth to engage in vigilantism. Political vigilante groups expect to be compensated for their role in securing electoral victory for their patrons and if these expectations are not met, vigilantes may resort to violence, either to demand their share of political rewards or to pressure politicians into fulfilling promises. Vigilantes’ use of violence to sabotage election processes raises the possibility of undermining national sovereignty and the democratic process by creating a climate of insecurity. If political vigilante groups continue to operate without resolving the related issues, they may eventually turn into militant organizations, which might have serious repercussions for an unstable and violent state. These risks make it more difficult for the state to fulfill its primary duty of protecting citizens. Political vigilantism not only poses a challenge to Ghana's democratic credentials in Africa, but it also poses a risk to the safety and security of Ghanaians. Vigilantism erodes the public trust, credibility and effectiveness of state institutions and law enforcement agencies such as the police and Electoral Commission. Ghana's soft power in international affairs tends to be undermined by political vigilantism. Consequently, to address the issue head-on, the study also recommends both state and non-state actors to adopt a broad-based strategy including rebuilding public confidence in state institutions through public education and strengthening law enforcement agencies. The study also recommends the incorporation of the role of nonstate actors, media, and activists in the securitization process to enhance how collective mobilization contribute to security politics.Keywords: Vigilantism, Democracy, Violence, Governance, Politics, Elections, Clientelism, Authority, Elite</p