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Expression and Localization of 5-HT Receptors in the Dorsal Horn of Rat and Human Spinal Cords
No full textSerotonin, or 5-HT, has gained attention in chronic pain research. While studies in rodents and serotonergic drugs link 5-HT to spinal pain processing, its mechanisms remain unclear. Human spinal cord studies on 5-HT receptor expression and potential sex differences are limited. This study maps 5-HT receptor distribution in rat and human spinal pain circuits using immunohistochemistry, qRT-PCR, and single-cell/nuclei RNA sequencing. We analyzed the spinal expression of all 5-HT receptor subtypes, focusing on 5-HT2C in dorsal horn circuits across spinal regions, sex, and species. Findings show dense expression of 5-HT2C and other subtypes in the dorsal horn's superficial laminae, crucial for nociception, in both rats and humans. This suggests spinal serotonin transmission plays a role in pain modulation
Development of a Displacement Device for Ion Extraction from Liquid Xenon
No full textNeutrinoless double beta decay () is a hypothetical process whose observation is the principal aim of many modern experimental efforts in the field of neutrino physics. This decay has garnered much interest since detecting this process would confirm the Majorana nature of neutrinos, and demonstrate a violation of lepton number conservation. Additionally, measuring the half-life of this decay would allow for the absolute mass scale of neutrinos to be determined. The of Xe is of particular interest as the Ba daughter can theoretically be tagged. This technique is called barium tagging, and requires the extraction of a single ion out of a large volume of liquid xenon. This work presents the complete development of a custom built and programmed displacement device with the capability of accurately positioning an ion extraction probe inside of a liquid xenon TPC for this purpose
Assessing water quality changes in eastern Ontario recreational lakes in relation to land-use and climate change impacts over the past ~150 years using paleolimnological techniques
No full textEastern Ontario is a lake-rich rural region, surrounded by deciduous and mixed-boreal forests, primarily lying over the Precambrian Shield. Lakes of this region are typically nutrient-poor (TP 20 µgL-1), such as Colonel By Lake and Dog Lake (part of the Rideau Canal) and others are moderately nutrient-rich (TP > 15 µgL-1), like Mississippi Lake. Despite their nutrient status, lakes of this region have experienced frequent nuisance and harmful algal blooms over the past two decades, affecting water quality and recreational use. Land-use and climate-mediated changes are known factors that can trigger algal blooms. However, the lack of long-term monitoring data makes it difficult to fully understand the underlying mechanisms. Therefore, in this study, a paleolimnological investigation is undertaken in the eastern Ontario region, examining 35 nutrient-limited lakes, nutrient-rich Colonel By Lake and Dog Lake, and mesotrophic Mississippi Lake. Diatoms (unicellular algae) are used here as a bioindicator, along with other proxies (e.g. cyanotoxin, chlorophyll-a), to reconstruct baseline conditions and track water quality trends over the last ~150 years. Study results revealed that both nutrient-poor and nutrient-rich lakes underwent minimal changes in their trophic state over the years. Analysis of spatial data and remote sensing images also revealed a positive correlation between the present-day land-use, particularly the percentage of croplands and wetlands in the lakes' nearshore zones and their nutrient state. Observed shifts in diatom species in nutrient-poor systems and presence of cyanotoxin in nutrient-rich lakes align with climate change indicators: increasing temperatures, longer ice-off periods, and reduced wind speeds, indicating the existence of coherent climate change signals across the region. This research demonstrates that both land use and climate change have had impacts on lake ecosystems in eastern Ontario over the ~150 years
Impacts of Connected, Automated Vehicle Behaviour on Transportation Greenhouse Gas Emissions
No full textThis study examines emissions from connected automated vehicles (CAVs) compared to driver-operated vehicles (DOVs) on four major Ottawa roads, indicating different road classifications. Its aim is to identify statistical models reflecting greenhouse gas (GHG) emission changes and to illustrate trends in traffic parameters and GHG emissions across different driving behaviours and traffic demands. Simulations cover three CAV driving behaviours and varied CAV penetrations from 0% to 100%, replicating projected 2031 morning peak traffic with ±20% volume fluctuations. Using a microsimulation traffic software, PTV VISSIM, and a motor vehicle emission simulator software, MOVES, emissions data is analyzed. Results show a correlation between CAV penetration and GHG emissions. Aggressive driving behaviour minimizes both traffic delays and emissions, followed by normal driving behaviour. These findings highlight the potential of CAVs in reducing emissions and traffic congestion. The developed models could aid policymakers and planners in mitigating emissions and congestion, promoting sustainable urban mobility
Vieni a Mangiare! A Cookbook Reflecting on Memory, Space and Community Building for Canada’s Italian Diaspora
No full textSince the early 20th century, Canada has been home to a large population of Italian immigrants; however, many cultural practices and traditions have begun to disappear as generations of Italian-Canadians emerge. When looking at diasporic communities, this thesis asks, how can the built environment offer the comforts of traditions while embracing positive assimilation? Through an examination of familial food practices revolving around food preparation, gathering, and eating, traces of the Italian diaspora in Canada are uncovered. Reflecting on themes revealed through the process of cooking and the creation of a cookbook, small scale interventions such as ceramic dinnerware sets and tablecloths inform the redesign of a home into a communal hub. By proposing communal ways of living, this thesis reflects on the notions of cultural preservation, memory, space, and community
Are roadkill hotspots the best places to mitigate for road mortality?
No full textThe common approach for mitigating the effects of road mortality is to install fencing at roadkill hotspots, where the most animals are being hit by vehicles. However, this approach could be missing populations that were previously depleted by heavy roadkill. Instead, mitigation could be targeted to “habitat-traffic hotspots,” where high-quality habitat is intersected by a high-traffic road and where per capita road mortality is highest. We compared mitigation sites for amphibians, mammals, and reptiles using roadkill hotspots and habitat-traffic hotspots along 77.6-km of roads near Ottawa, Canada. We found that roadkill hotspots and habitat-traffic hotspots did not generally coincide, especially for reptiles and mammals. This means that roadkill hotspots may not be the best method for identifying mitigation sites if the objective is to install fencing where they can most effectively mitigate the population-level effects of roadkill
Exploring the gene expression patterns of plant ACYL LIPID THIOESTERASEs (ALTs) through various analyses
No full textACYL-LIPID THIOESTERASE enzymes are found across all plant taxa and produce medium-chain fatty acids, methylketone precursors, and 3-hydroxy fatty acids. The aim of this thesis was to infer the biological roles of some ALT genes through tissue-specific expression patterns or responsiveness to environmental cues. Histochemical beta-glucaronidase (GUS) reporter gene staining of transgenic Arabidopsis thaliana lines demonstrated that ALT3 is widely expressed in aerial and root tissues. Additionally, internal cis-regulatory elements were important for AtALT3 gene expression. Using qRT-PCR analysis to examine AtALT3 transcript abundance from wounding or methyl jasmonate, I provide insight for future ALT analysis. Publicly available transcriptomic data sets were anlayzed to reveal ALT gene expression in various plant species can be upregulated during germination, and from submergence and biotic stressors - this suggests ALTs have diverse roles. The findings presented will direct future research to determine the potentially diverse functions of ALT enzymes
Oxidative stress responses in biofilms
Get PDFOxidizing agents are low-molecular-weight molecules that oxidize other substances by accepting electrons from them. They include reactive oxygen species (ROS), such as superoxide anions (O2 − ), hydrogen peroxide (H2O2), and hydroxyl radicals (HO− ), and reactive chlorine species (RCS) including sodium hypochlorite (NaOCl) and its active ingredient hypochlorous acid (HOCl), and chloramines. Bacteria encounter oxidizing agents in many different environments and from diverse sources. Among them, they can be produced endogenously by aerobic respiration or exogenously by the use of disinfectants and cleaning agents, as well as by the mammalian immune system. Furthermore, human activities like industrial effluent pollution, agricultural runoff, and environmental activities like volcanic eruptions and photosynthesis are also sources of oxidants. Despite their antimicrobial effects, bacteria have developed many mechanisms to resist the damage caused by these toxic molecules. Pre vious research has demonstrated that growing as a biofilm particularly enhances bacterial survival against oxidizing agents. This review aims to summarize the current knowledge on the resistance mechanisms employed by bacterial biofilms against ROS and RCS, focussing on the most important mechanisms, including the formation of biofilms in response to oxidative stressors, the biofilm matrix as a protective barrier, the importance of detoxifying enzymes, and increased protection within multi-species biofilm communities. Understanding the complexity of bacterial responses against oxidative stress will provide valuable insights for potential therapeutic interventions and biofilm control strategies in diverse bacterial species
Assessing the Environmental Impact: Office Building Reuse as a Sustainable Alternative to Demolition
No full textBuilding reuse is key to sustainability, given its potential to conserve resources, reduce waste, and foster sustainable development. However, determining the precise environmental impact of existing buildings through the quantification of embodied carbon in structures remains a challenge. To further our understanding of this impact's magnitude, this research quantifies the embodied carbon in an existing office building by examining three scenarios: "doing nothing," "building reuse," and "new construction." Through a combination of manual and tool-based calculations, the study compares the limitations of methods and the reliability and accuracy of results. Despite the variability of results, the findings still reveal that choosing the path of building reuse over demolition and reconstruction can mitigate the release of significant quantities of carbon into the atmosphere. These findings highlight the environmental implications of building reuse while advocating for standardized methodology, policies, and incentives
Pseudo-Homogeneous Sinusoidal Infill Using Non-Planar FFF Techniques for Use in RPAS Structures
No full textThis thesis investigates the development and testing of pseudo-homogeneous sinusoidal infill (PHSI) using non-planar fused filament fabrication (FFF) techniques for application in aerospace components, focusing on remotely piloted aircraft systems (RPAS). The objective is to enhance the mechanical properties of FFF-produced components through non-planar techniques while quantifying strength and modulus as bulk properties. A systematic methodology was employed, referencing industry standards. Statistical analysis confirmed the reliability and consistency of the mechanical performance improvement of PHSI parts, highlighting their potential for use in RPAS structural applications. This research builds upon previous studies at Carleton University, advancing the understanding of non-planar 3D printing methods and their impact on mechanical properties. The findings contribute to the ongoing discussion on certification standards for 3D printed RPAS components. The insights gained from this study are applicable to a wide range of components, encouraging further exploration of non-planar designs in aerospace applications