Impacts of edge proximity on bryophyte growth and soil quality in Nova Scotia farmlands

1 online resource (31 pages) : colour illustrations, maps, graphsIncludes abstract.Includes bibliographical references (pages 25-31).Agricultural practices reduce biodiversity and degrade soil quality on farms. Millions of dollars are spent yearly on the upkeep of the carbon content, bulk density and texture of agricultural soils. These qualities are all associated with the presence of biological soil crusts in natural dryland habitats. Biological soil crusts on Nova Scotia farmland are comprised mostly of bryophytes, which represent a unique and diverse set of species. Non-crop life in agricultural fields is often dependent on the field margin. Analysing the patterns of agricultural bryophytes can give us insight into their effects on soil health and biodiversity. Our aim was to examine the relationship between bryophyte abundance and distance from the field margin on Nova Scotia farmland, and to determine whether a pattern in abundance is the result of challenges to bryophyte propagule spread or because of environmental conditions preventing germination. We gathered bryophyte abundance data from eight Nova Scotia farm fields at increasing distances from the field edge. In each plot, we tested the soil quality and germinated propagules from the top 2 cm of soil in laboratory conditions to test for the presence of bryophyte propagules. Bryophyte abundance and the abundance of bryophyte propagules decreased with distance from the field edge, although the relationship was much stronger in the abundance of bryophytes compared to propagules. Bryophyte abundance was not related to any of the soil conditions examined. Therefore, we concluded that the decrease in bryophyte abundance from the field edge to the center was largely because of environmental conditions maintained by the field margin

2025-01-17 Senate Minutes and Agendas

Minutes and agenda for the January 17th, 2025 meeting of Saint Mary’s University Senate

Deep learning approaches for linear feature segmentation in remote sensing and astronomical imagery

1 online resource (101 pages) : illustrations (some colour), charts (some colour), graphs (some colour)Includes abstract.Includes bibliographical references (pages 76-101).Linear features, defined by their elongated geometry, are critical in domains such as transportation (roads, railways), environmental monitoring (rivers, pipelines), and astronomy (satellite streaks). Accurate segmentation of these features supports automated analysis and decision-making. This research focuses first on road infrastructure, introducing an innovative framework for health assessment using high-resolution satellite imagery, Gray Level Co-occurrence Matrix (GLCM) texture features, and a cyclic reinforcement learning agent. The model dynamically predicts Pavement Condition Index (PCI) and International Roughness Index (IRI), achieving low error and strong generalization on Alberta’s Open Road dataset, offering a cost effective alternative to manual or sensor based methods. Beyond transportation, we address segmentation of elongated satellite streaks in astronomy using an enhanced U-Net trained on the SatStreaks Dataset, achieving superior accuracy and precision compared to baseline models. Together, these contributions demonstrate the versatility of deep learning and reinforcement learning in detecting, segmenting, and assessing linear features across diverse imaging domains

Fungicide sensitivity of Fusarium spp. isolated from decaying potato seed tubers

1 online resource (iv, 34 pages) : illustrations (some colour), graphsIncludes abstract and appendix.Includes bibliographical references (pages 23-24).One of the most detrimental seed and storage diseases affecting potato agriculture is the fungal disease known as dry rot. This disease is caused by various species of Fusarium, which enter tubers through ruptures in the skin, that occur frequently during mechanized harvesting and handling, as well as during seed cutting prior to planting. Disease symptoms appear as sunken patches of darkened tissue which are often lined with mycelia and spores. Fusarium dry rot can cause losses in storage as well as reduced emergence when affected seed is planted. Post-harvest and seed treatment applications of chemical fungicides are the most common treatment methods, however, in the spring of 2024, Agriculture and Agri-Food Canada (AAFC) received seed tuber samples from growers in Prince Edward Island (PEI) that presented with dry rot despite having been treated with prothioconazole. Resistance to this chemical in Fusarium species has not yet been observed in PEI. As such, the resistance profile of the pathogen was determined by testing three isolates obtained from sample tissue (PEF 3355-2, 3355-3, and 3355-6) against eight concentrations (0, 0.01, 0.1, 1.0, 5.0, 10.0, 50.0, and 100.0 μg/ml) of fungicides commonly used for dry rot management, including difenoconazole, fludioxonil, prothioconazole, and thiabendazole. DNA sequencing was also conducted which identified the species of the pathogen as F. sambucinum. This strain showed resistance to thiabendazole for all isolates tested (EC50 of 17.82, 16.91, and 21.82 μg/ml for PEF 3355-2, 3355-3, and 3355-6, respectively), but had no high level resistance to difenoconazole or prothioconazole. Resistance to fludioxonil was originally absent, but the development of mutations in vitro resulted in fungal sectors with resistance to this chemical in some isolates

Timing and nature of mafic magmatism and iron-alkali-calcic metasomatism at Clarke Head, Nova Scotia

1 online resource (90 pages) : illustrations (some colour), maps (some colour), charts (some colour), graphs (some colour)Includes abstract and appendices.Includes bibliographical references (pages 76-84).The objective of this project is to constrain the timing of mafic magmatism and metasomatism at Clarke Head, Nova Scotia, and to discern their relationships to metasomatic occurrences along the Cobequid-Chedabucto Fault Zone (CCFZ). Clarke Head is located within the CCFZ, a 300 km E-W striking, terrane-bounding fault system that hosts numerous metasomatic iron ± copper, gold, and cobalt deposits suggested to be part of a Metasomatic Iron Alkali Calcic system. The source of metasomatic fluids may be from the melting or dissolution of Viséan-aged Windsor Group carbonates and evaporites by mafic magmatism. Field evidence of mafic rocks north of and east along the CCFZ indicate syn- to post-Viséan magmatism occurred. Clarke Head exposes a megabreccia, bounded to the north by the Clarke Head fault, a NE-SW striking fault splay of the CCFZ, that incorporates igneous and sedimentary blocks of varying size, age, and deformation history. Metasomatism related to the undated igneous blocks at Clarke Head may be related to this hydrothermal event. Field work and petrography aided by scanning electron microscopy and micro-X-ray fluorescence spectroscopy show that primary minerals in monzodiorite and gabbro blocks, consisting of andesine-labradorite, are overprinted by metamorphism followed by metasomatism. The metamorphic assemblage consists of Cl-rich hornblende-pargasite-actinolite + Cl-F-rich apatite + LREE-rich epidote + magnetite + hematite + Co-rich pyrite ± Cl-rich biotite, consistent with greenschist/amphibolite facies metamorphism. Three hydrothermal alteration events are shown through assemblages consisting of: i) apatite + chlorite + scapolite ± oligoclase ± albite ± pumpellyite ± quartz ± K-feldspar, ii) analcime, and iii) calcite. In-situ U-Pb Laser Ablation Inductively Coupled Plasma Mass Spectrometry of hydrothermal and altered primary apatite yielded no successful ages due to low U contents (<0.1 ppm). Results show alteration may be related to alteration at the Bass River Fe-Co prospect and the West Moose River pluton

Nature-based coastal adaptation approaches : spatial modelling and community perception of barriers and opportunities in Ghana

1 online resource (vii, 134 pages) : colour illustrations, colous maps, charts (some colour), graphs (some colour)Includes abstract and appendices.Includes bibliographical references (pages 106-123).Ghana’s coastal areas face increasing risks from coastal hazards. While conventional engineering approaches (seawalls and groins) have been the primary mitigation strategies, they often prove unsustainable. Adaptation planning efforts have widely failed to account for local community knowledge. As a result, this study explored community perceptions of risk to coastal hazards, assessing opportunities for nature-based coastal adaptation (NbCA) approaches using GIS, participatory mapping, and household surveys across three communities in Accra. The study showed significant differences in perceived risk, with older age groups (60+) expressing higher vulnerability. Awareness of NbCA was uneven, with 72% of respondents in Bortianor reporting familiarity due to existing mangrove restoration, compared to Jamestown (37.5%) and Teshie (10%). Despite this, there was a high expression of support for NbCA. Furthermore, participatory mapping identified community-perceived high-risk areas, which showed spatial consistency with GIS risk models. The findings emphasize the importance of inclusive, context-sensitive, and evidence-based adaptation planning

An analysis of coastal lagoons and barriers along the Atlantic Coast of Nova Scotia, Canada

1 online resource (vii, 66 pages) : colour illustrations, colour maps, charts (some colour), graphs (some colour)Includes abstract and appendix.Includes bibliographical references (pages 61-63).The province of Nova Scotia, Canada, is abundant with coastal landscapes and diverse terrain; and is the chosen study area because of the coastal lagoons that exist on the Atlantic coast. Coastal lagoons, inland waterbodies separated from the ocean by only a barrier beach, are productive and valued wetland environments for their ecosystem services and protection against shoreline erosion. This study involved the creation of an ArcGIS inventory of 873 coastal lagoons along the Atlantic coast of Nova Scotia that have intact barrier beaches. Additionally, time change analyses and cross-sectional profiles were completed for a select number of sites within the study area, to demonstrate how coastal lagoons are affected by ocean water levels rising at Nova Scotia’s rate of approximately 32 cm per century, and coastal change over time. Results show that while many coastal lagoons exhibit sensitivity to environmental change, their rates of change vary, with some lagoons remaining relatively stable over several decades. Notably, lagoons with longer barrier beaches displayed more pronounced changes over time, particularly in response to storm surges. The study found no direct relationship between barrier beach structure (as measured by topographic profiles) and overwash frequency. However, climate-driven coastal stressors such as erosion and storm activity remain critical drivers of coastal change. This research highlights the importance of identifying and classifying coastal lagoons for land-use planning and hazard assessment. The use of historical imagery proved effective in visualizing coastal change, with room for more research as extended temporal analysis could reveal different trends. Overall, this study provides a spatial framework for understanding Nova Scotia’s coastal lagoons and why they matter in a changing climate

<p>Investigation of the N=8 Shell Closure Through the One-Neutron Transfer ²⁰Mg(<em>d</em>, <em>p</em>) ²¹Mg Reaction</p> <p>&nbsp;</p>

1 online resource (ix, 43 pages) : colour illustrations, charts (some colour), graphs (some colour)Includes abstract.Includes bibliographical references (pages 42-43).Exotic nuclei, those characterized with a large asymmetry in their number of protons and neutrons as well as exceptionally short half-lives, are transforming our understanding of the nuclear force. The nuclear shell model predicts that isotopes with certain numbers of protons and neutrons, those corresponding to complete shells, should be more bound than other neighbouring isotopes. However, these known shell closures are showing signs of vanishing in some exotic nuclei. In this study we investigate the N = 8 shell closure at the proton drip line in the exotic Borromean nucleus 20Mg through the one neutron transfer 20Mg(d, p)21Mg reaction. This experiment was performed at the IRIS facility at TRIUMF. It was determined that the reaction populated the ground state of 21Mg, which has J&pi; = 5/2+ as well as the four lowest energy excited states with excitation energy 0.206, 1.08, 1.65, and 1.99 MeV and J&pi; = 1/2+, 1/2&minus;, 3/2+, and 3/2&minus; respectively. The fact that the J&pi; = 1/2&minus; and 3/2&minus;excited states were populated point toward a breakdown of the N = 8 shell closure in 20Mg.</p

Electrochemical surface-enhanced raman spectroscopy as a tool for the characterization of products of azo dye degradation

1 online resource (xv, 86 pages) : illustrations (some colour), charts (some colour), graphs (some colour)Includes abstract and appendix.Includes bibliographical references (pages 68-78).Azo dyes are colourants that continue to be used in various industrial applications such as in foodstuff, textiles, inks, and more due to their vivid colours, easy accessibility, low cost and lightfastness. Despite their various benefits, azo dyes pose a risk to human health due to their adverse effects, which in some cases has been linked to the degradation products of the dyes that can naturally form upon metabolism in the human body. Most prior methods of analysis and characterization of azo dyes and their degradation products involve complex instrumentation requiring highly trained personnel, costly repairs and time-consuming sample preparation. Given this, there is a need to develop other more accessible, portable and cost-effective methods for the analysis of azo dyes and their degradation products. This thesis research demonstrates the first use of electrochemical surface-enhanced Raman spectroscopy (EC-SERS) as a possible characterization tool for the analysis of the azo dyes Acid Orange 7, Metanil Yellow, and Methyl Orange to address this gap in the literature. EC-SERS was also assessed as a potential tool for the spectroelectrochemical monitoring for a plasmon-mediated or electrochemical degradation of the above-mentioned target dyes, although this endeavor remained unsuccessful and is subject to future work. Various characterization methods including cyclic voltammetry, UV-visible spectroscopy, and computational studies were used to support the findings in this thesis research

Talking for change : examining helpline conversations from a child sexual abuse perpetration prevention program

1 online resource (vi, 98 pages) : chartsIncludes abstract.Includes bibliographical references (pages 83-98).This study examines the child sexual abuse perpetration prevention program Talking for Change, which offers an anonymous digital helpline for users to connect with clinicians and receive support. Chats (n = 189) between clinicians and those concerned about their sexual interest in children or risk of offending were coded using content analysis to explore how users engage with the digital helpline and what resources clinicians provide. Users were concerned about their thoughts, feelings, or arousal in most chats (67.7%), followed by concern about child sexual exploitation material (CSEM) use (39.2%), and risk of contact offending (15.9%). Users contacted the helpline for support, resources, and information about their interests. Mental health concerns and negative emotional states (e.g., shame) were present. Help-seekers were dedicated to living an offence-free lifestyle, although CSEM use was a concern. Clinicians provided resources, managed high-risk situations, and explained ethical and legal obligations. Overall, users expressed satisfaction with the helpline