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The accelerated recovery of base-poor soils from the legacy effects of acidic deposition may be possible by applying industrial wood ash as a soil amendment. Wood ash may be an effective soil amendment due to its high alkalinity and concentrations of several essential nutrients, such as calcium, magnesium, potassium, and phosphorus, that are retained after the volatilization of the parent material. However, wood ash can also contain trace amounts of metals that could be released into the soil and soil solution. The short-term (<3 years) biogeochemical response of soils, microbial communities, and sugar maple (Acer saccharum Marsh.) trees were assessed following wood ash application at Porridge Lake, Ontario. The study design consisted of five blocks containing three treatment plots each (2.5, 5.0, 7.5 Mg ha-1) and a control. Soil solution pH, base cation, and trace metal concentrations were monitored for three years, using tension lysimeters at depths of 30 and 60 cm and zero-tension lysimeters for forest floor percolate within each plot. In the last year of the trial, soil, foliage, and fine root samples were collected and analyzed for trace elements. Also, soil samples were analyzed for the abundance of 16S and ITS DNA through metabarcoding to ascertain the microbial response to wood ash. Significant changes in soil solution pH were measured within the forest floor horizon in the first year of the trial. Significant increases in calcium (Ca), magnesium (Mg) and calcium/aluminum (Ca/Al) ratios were also observed in the second year of the trial, along with decreases in dissolved organic carbon (DOC), sulphate (SO4) and nitrate (NO3) in the LFH horizon. By the third year of the trial, significant increases in soil solution pH and potassium (K) concentrations and decreases in Al were observed to a depth of 30 cm. Changes in trace metal concentrations in soil water were notably variable, with concentrations of chromium, copper, lead, nickel, and selenium remaining unresponsive, whereas concentrations of cadmium, manganese and zinc decreased by the third year. The metalloid arsenic showed a significant increase in the third year of the trial but remained below regulatory guidelines, similar to all other trace metals. Soil measurements conducted in the third year of the trial showed positive pH responses in the FH horizon and increases in Ca and Mg in the Ah and Bm soil horizons, but foliar base cation and metal concentrations were unchanged. Diversity analysis on the soil prokaryotic and eukaryotic groups indicated increased bacterial alpha diversity in the FH horizon and bacterial dominance in the litter horizon. Analysis of relative abundance at the phylum level for prokaryotes and at the order for eukaryotes did not indicate any compositional shifts due to the wood ash treatments. Changes in the length and diameter of sugar maple and mycorrhizal fine root may point to pH shock being an issue at higher ash doses. The results from this study indicate that wood ash has a strong ameliorative effect on soil properties and does not pose a risk to soil communities. 

Author Keywords: DNA, mycorrhizae, soil acidication, soil amendments, soil solution, sugar maple

The COVID-19 pandemic resulted in drastic impacts for people with disabilities across Canada. The pandemic opened questions about what meaningful access practices are and how these can be utilized to better engage people with disabilities in the arts. 10 participants, comprised of people with disabilities, were recruited for semi-structured interviews to understand their experiences with the local arts over the past five years. Five themes arose within the data findings, including: Access as Community-Based Care, On the Fringe, Access Labour, Passive Consumption, and Neoliberal Compliance. A document analysis was conducted to compare the participants' views on effective access practices to the recommendations included in the Accessibility for Ontarians with Disabilities Act. Using a critical disability studies lens, the thesis concluded that meaningful access emerges through the grassroots work of communities, requiring ongoing communication with and between invested parties to prioritize the complex and unique needs of those with non-normative body-minds.

Author Keywords: accessibility, arts, covid-19, critical disability studies, disability, neoliberalism

This intercultural rediscovery of Indigenous cacao culture draws upon Environmental Studies, Intercultural Studies, Indigenous Studies, Anthropology and Agroecology. The methodological antecedent for this kind of symbolic food study of cacao is the work done by Gustavo Esteva and others on the civilizational importance of maize. Similarly, the rediscovery of the Indigenous Knowledge of cacao explores the profound meaningfulness of cacao to ancient Mesoamerican civilization, and how that ecological, agricultural, and health wisdom can regenerate modern agricultural paradigms, and ecogastronomy. Chapter 1 explores, meditates, and reflects upon 20 Indigenous Knowledge teachings of cacao guided and supported by a unique interpretation of the Popol Vuh, the Mayan oral epic and creation story, as well as 20 years of collaboration and field work experience in Mexico. The methodology in chapter 1 is rooted in a phenomenological approach to dwelling with and relating to IK in an unmediated and embodied manner. Experience, story, dream and an awareness of the challenges of looking at Oral culture teachings are combined with an intercultural analysis of the Popol Vuh and other supporting texts. The spiritual ecology of the cacao forest garden of Chapter 2, seeks to make the connection between the maize milpa and the cacao forest garden milpa and posits a unique transition theory. The transition theory seeks to operationalize these Indigenous Knowledge agricultural and crop traditions into a regenerative agricultural model. Based upon Indigenous Knowledge, this view of the cacao forest garden functionally regenerates soils, regenerates forests, and supports food sovereignty in a way that is rooted in community scale Indigenous cultural practices, techniques, and food traditions. The methodology for chapter 2 and chapter 3 of this thesis moves to an intercultural comparison and analysis of agro-ecological and spiritual ecological understandings of cacao, chocolate, and the forest garden. Chapter 3 seeks to move from the explicating and analyzing of the 'transition theory' and proposes four main practical initiatives that further strengthen and explore the regenerative spiritual ecology of cacao forest gardens. The Indigenous forest garden commons of the Americas can be a powerful, unique, and fecund contribution to the intercultural dialogue around cultural regeneration in the 21st century. The Indigenous forest garden makes contributions around intercultural dialogue and reconciliation as well as current understandings around regenerative agricultural models. The cacao forest garden moves beyond an either/or narrative that separates environmental regeneration from cultural regeneration, and instead contributes to an intercultural both/and more holistic approach to regeneration that is rooted in culture and supported by agriculture.

Author Keywords: cacao, chocolate, forest garden, indigenous kmowledge, maize, transition theory

This study reports on as series of laboratory wind tunnel experiments aimed at furtheringour understanding of aggregate breakdown and dust release during aeolian transport, and thereby, has implications for air quality and the management of dust emission through water application. Particles aggregates 500 um in diameter were formed and isolated by the wetting, drying, and screening of playa sediments collected from Owens Lake. They were then released into a boundary-layer flow within the Trent Environmental Wind Tunnel (TEWT), whereupon they either slid, rolled and/or saltated downwind. The concentration of PM10 and the particle size of the aggregates were monitored throughout each test along the central axis of the tunnel. The results confirm that aggregate breakdown did occur, resulting in the production and emission of dust. The relative efficiency of aggregate abrasion in the production of silt sized particles during aeolian transport was calculated using normalized indices, providing a starting point for the modelling of similar systems in a natural setting. The results indicate that for every metre of transport, the abrasion of a 500 um aggregate formed from playa sediment may release a volume of dust roughly equivalent to that of a single silt particle that is 60 um diameter. Conversely, aggregate formation is found to produce 1-4% of dust as compared to an equivalent volume of disaggregated silt when exposed to a given airflow above the threshold for saltation.

Author Keywords: Aeolian abrasion, Aggregate breakdown, Owens Lake, PM10, Saltation, Wind Tunnel

Heated leaf extracts of Euphorbia neriifolia (sweet aloes) are used traditionally in Guyana for asthma therapy, but the phytoconstituents have not been studied and phytohormones are generally unexplored in Euphorbia species. Phytoconstituents in asthma-effective traditional heated extracts were analyzed and compared with unheated leaves and latex extracts as screens to identify candidate compounds for asthma treatment. Analysis employed untargeted and targeted mass spectrometry-based metabolomics. The untargeted approach revealed thousands of features in samples with higher abundance in heated extracts and confirmation of 33 metabolite identities (confidence levels 2 and 3) which are known to have antioxidant and anti-inflammatory properties. Highly accumulated and unique features were detected in latex, and those characteristic compounds may reflect the expanded therapeutic uses of E. neriifolia globally. A targeted metabolomic analysis identified and quantified several cytokinins, including aromatic kinetin, and acidic phytohormones. Traditional heating improved the content of several cytokinins with known therapeutic potential, indicating they may be candidates for asthma management.

Author Keywords: asthma, cytokinins, Euphorbia neriifolia, metabolomics, sweet aloes, traditional remedies

Arturo Cruz Jr., born in 1953, was a highly influential and respected figure in Nicaraguan Politics. He was involved in the Contras. Cruz played a crucial role in supporting the Contras, helping to secure U.S. funding for the group which was a rebel group formed by the US against the Sandinista dictatorship in the 1980s. Later, he also served as the Nicaraguan ambassador to the US between 2007 and 2009. His involvement in the Contras was a controversial part of his career, but it did not define his contribution to Nicaraguan Politics. In this role, he worked tirelessly to influence American foreign policy towards his home country, which included advocating for democracy, human rights, and press freedom. Cruz's efforts to promote these values were a testament to his dedication to improving the lives of Nicaraguans. Cruz was deeply involved in various peace agreements in Central and Latin America, working towards resolving conflicts and promoting stability in the region. His contribution to the region went beyond Nicaragua, and he was well-respected for his efforts towards promoting peace and stability. Throughout his career, Cruz was a strong advocate for democracy and human rights. He believed that these values were essential for a country to prosper and develop. Cruz was a vocal advocate for press freedom and recognized the critical role of the media in promoting democracy and holding government officials accountable. This biographical study aims to explore the life and contributions of Arturo Cruz Jr. towards Nicaraguan Politics and the wider Latin American region. Through a detailed analysis of his life, this study seeks to shed light on an important

Migratory fish can influence the rivers where they spawn by depositing nutrients and organic matter which increase primary and secondary production. Past research in the Laurentian Great Lakes has focused on individual tributaries, accordingly, the spatial extent of subsidies and how environmental factors influence subsidies are not clear. To determine which tributaries received subsidies, I compared stable carbon isotope values (δ13C) of resident stream fishes above and below 54 barriers in 37 tributaries. Subsidies were found in found across 43 of the barriers. The subsidy magnitude varied among the lakes, with Lake Superior having significantly larger subsidies. Correspondence analysis of environmental factors showed that large differences in δ13C were associated with steeper river channels on the Canadian Shield with little agricultural land-use. Migratory fish supply resource subsidies to rivers across the Great Lakes basin, though their magnitude is contextually dependent.

Author Keywords: barriers, Great Lakes, migratory fish, resident stream fish, resource subsidies, stable isotopes

Mineral feedstocks, including alkaline mine wastes, can sequester CO2 as a dissolved phase (e.g., HCO3-) or a solid carbonate via enhanced rock weathering (ERW). For this thesis, the release of easily accessible Ca and Mg from non-carbonate sources was determined for kimberlite residues from several diamond mines and commonly proposed ERW rock types, including wollastonite and olivine. Batch leaches determined the CO2 sequestration potentials of kimberlites to be in the range of 3–12 kg CO2/t, which was exceeded by most ERW feedstocks. Leaches also assessed the release of Ni and Cr, elements of concern in ERW settings, and P and K, which benefit agricultural soils. Year-long leaching columns were deployed using kimberlite from the Gahcho Kué and Venetia diamond mines, wollastonite skarn, and olivine sand from the initial assessment. The kimberlite residues sequestered 0.03 kg CO2/t as dissolved inorganic carbon and 0.6 kg CO2/t as solid total inorganic carbon. Weathering of wollastonite skarn resulted in CO2 removal rates via mineral trapping of CO2 of 6.31 kg CO2/t, while the olivine sand yielded rates of 0.5 kg CO2/t via solubility trapping. Both methodologies used in this study demonstrated value in the prediction and monitoring of drainage chemistry as it relates to ERW and CO2 mineralization. Implementation of these strategies can progress ERW efforts by providing confidence in feedstock selection and the verification of carbon offsets.

Author Keywords: CO2 mineralization, Drainage chemistry, Enhanced weathering, Mine wastes, Mineral trapping, Solubility trapping

To examine comorbid pain sensitivity, temporal lobe epilepsy was modeled with a 42-stimulation amygdala kindling paradigm using rats. Sham and kindled rats' mechanical allodynia was not different before the formalin conditioned place aversion (FCPA) test. FCPA behaviour was not different, but twenty-four hours later kindled rats showed mechanical allodynia. Thermal sensitivity 48 hours after FCPA was not different. A second experiment revealed no difference in pre- and interictal mechanical and thermal sensitivity. Kindled rats did display a higher frequency of pain behaviours in the formalin nociceptive test, and greater early growth response 1 expression in the anterior cingulate cortex (ACC). The final experiment examined FCPA behaviour of sham and kindled rats given an ACC infusion of control (EGFP), or inhibitory designer receptor exclusively activated by designer drug (hM4Di). Kindled-EGFP rats did not spend a different amount of time in either compartment but Kindled-hM4Di rats spent more time in the formalin-paired compartment.

Author Keywords: Affective Pain, Amygdala Kindling, Emotion, Epilepsy, Pain

Mining and smelting degraded landscapes are characterised by heavily eroded soils that are acidic, contaminated with toxic metals, and depleted of essential nutrients. Regreening degraded landscapes has been proposed to support global carbon (C) mitigation measures and protect biodiversity. One of the world's largest regreening programs in the City of Greater Sudbury, Canada has been ongoing since 1978 and involves liming and fertilizing selected areas followed by planting primarily jack pine (Pinus banksiana Lamb.) and red pine (Pinus resinosa Ait.) trees. The main objective of this thesis was to improve our understanding of biogeochemistry in the City of Greater Sudbury regreened forests, and to determine how nutrient pools and cycling change as stands age. I established a chronosequence of forested sites between 15–40 years-old and to account for the effects of erosion, each site was categorized as "stable" (<10% bedrock cover) or "eroded" (>30% bedrock cover). Individual tree growth and nutrient accumulation in aboveground biomass (AGB) did not differ between stable and eroded sites and were comparable to rates reported from pine plantations in similar ecozones. Aboveground nitrogen (N) pools were six times larger than N applied in fertilizer, suggesting N limitation is most likely not a concern. Rates of C cycling were generally similar to those measured at unimpacted jack and red pine plantations. The exception being a decrease in mineral soil and aggregate C concentrations. However, at the ecosystem-scale the loss of soil C is trivial in comparison to increases in AGB C pools, leading to an overall increase in total ecosystem C following regreening (550,547 Mg in aboveground C across the 19,649 ha regreening landscape). Litter decomposition rates were higher at the regreening sites using a site-specific litter compared to a general common litter, indicating a home-field advantage for local decomposers. Soil temperature varied at the regreening sites and higher soil temperatures were related to higher rates of soil respiration. The regreening sites are rich in calcium (Ca) and magnesium (Mg); and while soils were generally poor in phosphorous (P) and potassium (K), foliar concentrations of P and K were comparable to those of "healthy" red pines. Overall, the regreening program appears to have increased tree growth and produced jack and red pine plantations that are biogeochemically similar to conifer plantations unimpacted by over a century of mining and smelting impacts.

Author Keywords: biogeochemistry, degraded landscape, forests, nutrient cycling, regreening, soil carbon