Experimental investigation of effect of cement content and sulphate concentration on loading rate-dependent fracture behaviour of CPB under Mode I, II, and III loading conditions

Cement paste backfill (CPB) technology is becoming the standard mine backfilling approach in the mining industry as an environmentally friendly and cost-effective way to manage tailings. Most importantly, CPB plays a critical role in ground support to the surrounding rock mass to ensure the safe and effective operation of the mine. After placement into the mined-out voids, the CPB structure is subjected to complex loading conditions. Due to the dependency of mechanical behaviour on the loading rate, CPB may demonstrate distinctive response and fracture failure characteristics under field loading conditions. However, previous research has primarily concentrated on traditional geomechanical behaviours, ignoring the impact of loading rate on the fracture behaviour of CPB, which significantly influences the assessment of mechanical behaviour and performance of in-stope CPB. Meanwhile, as a cementitious composite, the chemical factors, including cement content and sulphate concentration, dominate the evolution of the mechanical properties of CPB. Therefore, it is of theoretical and practical importance to investigate the effects of cement content and sulphate concentration on CPB's loading rate dependent fracture behaviour. The research aims to evaluate the loading rate dependent fracture behaviour and properties of CPB under different loading conditions. [...

The relationship between sex, gender, and workplace accommodations among workers with mental health disorders

In 2022, over 5 million Canadians (18%) reported having a mood, anxiety, or substance use disorder over the last 12 months (Stephenson, 2023). These disorders can be attributed to environmental, physiological, genetic, chemical, and social influences. Globally, mental health disorders have been projected to cost the economy $16.1 trillion USD in lost productivity between 2010 and 2030, while also being a main contributor to noncommunicable disabilityadjusted life years lost (Bloom et al., 2011). These economic costs underestimate the full extent of the human suffering experienced by individuals and their families due to mental illness. Workplace accommodations are essential to support individuals with mental health disorders. Almost 40% of employees aged 25-64 with mental health and/or physical disabilities require workplace accommodations. Of these, women have a higher unmet need for accommodations than men, in addition to requiring more accommodations than men (Morris, 2019). Accommodations for mental health disorders are critical in helping employees cope with transient or temporary mental health issues, resulting in longer job tenure, being able to work more hours, and remain employed (Chow, Cichocki, & Croft, 2014; McDowell & Fossey, 2015; Zafar, Rotenberg, & Rudnick, 2019). These accommodations often include flexible work arrangements, job duty modifications, job coaching, feedback from supervisors, and gradual return to work (Bastien & Corbière, 2019; Corbière, Villotti, Lecomte, Bond, & Goldner, 2014; McDowell & Fossey, 2015; Villotti et al., 2017; Zafar et al., 2019). [...

Supporting the executability of R markdown files

R Markdown files are examples of literate programming documents that combine R code with results and explanations. Such dynamic documents are designed to execute easily and reproduce study results. However, little is known about the executability of R Markdown files which can cause frustration among its users who intend to reuse the document. This thesis aims to understand the executability of R Markdown files and improve the current state of supporting the executability of those files. Towards this direction, a large-scale study has been conducted on the executability of R Markdown files collected from GitHub repositories. Results from the study show that a significant number of R Markdown files (64.95%) are not executable, even after our best efforts. To better understand the challenges, the exceptions encountered while executing the files are categorized into different categories and a classifier is developed to determine which Markdown files are likely to be executable. Such a classifier can be utilized by search engines in their ranking which helps developers to find literate programming documents as learning resources. To support the executability of R Markdown files a command-line tool is developed. Such a tool can find issues in R Markdown files that prevent the executability of those files. Using an R Markdown file as an input, the tool generates an intuitive list of outputs that assist developers in identifying areas that require attention to ensure the executability of the file. The tool not only utilizes static analysis of source code but also uses a carefully crafted knowledge base of package dependencies to generate version constraints of involved packages and a Satisfiability Modulo Theories (SMT) solver (i.e., Z3) to identify compatible versions of those packages. Findings from this research can help developers reuse R Markdown files easily, thus improving the productivity of developers. [...

Are the fish safe to eat? An examination of Lake Nipigon fish consumption guidelines through the perspective of Biinjitiwaabik Zaaging Anishinaabek

Mercury (Hg) is a contaminant of concern when consuming fish from freshwater lakes. It is known to persist in high concentrations in piscivorous fishes such as Walleye which are commonly consumed by people. The people from the community of Biinjitiwaabik Zaaging Anishinaabek (BZA) Rock Bay have harvested fish from the Lake Nipigon basin for millennia and have observed changes to the Lake, particularly those resulting from resource development and extraction. Large scale hydroelectric projects and mining have created concerns over the safety of eating Walleye in the Lake Nipigon basin from traditional fishing locations. While fish consumption guidelines are posted by the provincial government for certain areas, a lack of robust data, trust, transparency and communication about the risks of exposure to consumers has rendered these guidelines largely ineffective for community use. In this study, data collection was led by community fishermen to collect fish from traditional fishing locations to produce community driven fish consumption guidelines. In general, fish consumption guidelines produced from community sampling were less restrictive than those posted by the provincial government where comparable. However, community-based fish consumption guidelines were more restrictive in riverine environments than lake sampling locations. As a result of having engaged in data collection and monitoring for fish contaminants, BZA has developed greater trust and interest in fish consumption guidelines while greatly enhancing its lands and resources program to further study concerns on Lake Nipigon

The response of the occupational therapy profession to the Truth and Reconciliation Commission’s health calls to action

For over a century, the central goals of Canada’s Indigenous policies were to eliminate Indigenous governments, rights, and treaties, and through this process of assimilation cause the extinction of Indigenous Peoples (Truth and Reconciliation Commission [TRC], 2015). Residential schools were a central component of this assimilation process, which can best be described as “cultural genocide” (TRC, 2015). The Truth and Reconciliation Commission (TRC) describes cultural genocide as the “destruction of those structures and practices that allow [a] group to continue as a group” (TRC, 2015, p. 1). The Canadian government worked to remove Indigenous children from their homes, sending them to residential schools with the main purpose of breaking the connections to their culture and identity. For residential school students, neglect, lack of supervision, and physical and sexual abuse were common within the schools, along with discouragement and prohibition of engaging in traditional practices and speaking their own languages (TRC, 2015). Canada further pursued and supported the goal of cultural genocide in relation to Indigenous Peoples to remove itself from legal and financial obligations and to gain control over land and resources (TRC, 2015). Due to policies under the Royal Proclamation of 1763, Indigenous Peoples reserved all land not ceded by or purchased from Indigenous Nations. Between 1871 and 1921, Canada negotiated 11 treaties with Indigenous Peoples which provided the Crown with land for industrial and settler development in exchange for various promises including special rights to treaty land and distribution of resources. [...

Effect of boreal forest disturbance due to logging at different spatial scales on migratory songbirds

Boreal birds have experienced population declines that may be related to alteration of the forest at a range of scales. Understanding how resource extraction may affect the distribution and abundance of species is critical to address conservation policy in the boreal forest region. This study aims to understand how habitat alteration by logging influences the abundance and habitat choices of a migratory songbird, the Canada Warbler (CAWA; Cardellina canadensis) in its Canadian breeding range and more specifically within the northwestern region of Ontario, where there is little information about this species at risk. I assess whether there exists a different response in the abundance of upland migratory songbirds to logging disturbance at different scales. Also, I assessed the “habitat compensation hypothesis,” which states that some species can substitute their primary habitat for other alternative and less preferred habitats on the landscape. I conduct a meta-analysis of 21 studies to identify the effects of habitat alteration on a relative abundance index (RAI) of 21 upland songbird species, comparing logged to unlogged sites along the southern border of Canadian boreal forest. Using generalized linear mixed models (GLMM), I model the RAI incorporating two scales (local- and landscape-scale effects), time since logging, and forest type. Several species, including CAWA, are reported in decline in Canada. They occasionally have a higher mean RAI comparing logged areas at landscape scale than comparing at the finer local scale, suggesting that they occupy lower quality habitats in disturbed areas. The results are consistent with other findings: birds associated with old-growth forests are most sensitive to logging, as well as birds that nest on trees and those more associated with a coniferous forest. I then assess how time since logging affects CAWA occurrence and distribution in Northwestern Ontario. I use Maxent software to develop a predictive highresolution (30 m) field-validated species distribution model (SDM). [...

Unveiling the hidden pandemic: service provider perspectives on the rise in intimate partner violence (IPV) in Northwestern Ontario midst the COVID-19 pandemic

Intimate partner violence (IPV) is a public health concern that can affect individuals regardless of gender, socioeconomic status, sexual orientation, ethnicity, and geographic location (Moreira & Pinto da Costa, 2020). However, women are disproportionately represented in victimization rates worldwide with the World Health Organization reporting that on average 35% of women - more than one in three women - have experienced at least one form of physical, psychological and/or sexual violence perpetrated by an intimate partner throughout their lifetime (Moreira & Pinto da Costa, 2020; UN Women, 2020). Rural, remote and northern (RRN) regions in Canada present the highest rates of IPV and femicide compared to urban centres, while having limited availability of IPV services (Moffitt et al., 2022). In times of crisis, IPV cases increase drastically; this is documented, for example, during Hurricane Katrina and the Ebola crisis (Meinhart et al., 2021; Schumacher et al., 2010). The COVID-19 pandemic has followed this trend as the amalgamation of risk factors including heightened stress, increased rates of substance abuse, economic uncertainty due to loss of employment, and stay-at-home orders contributed to unfavourable violence-prone domestic environments across the globe (Kaukinen, 2020; Kofman et al., 2020). The primary objective of this research is to understand the challenges faced by IPV service providers and survivors during the COVID-19 pandemic in the context of Northwestern Ontario (NWO), from service providers’ perspectives. Service providers were asked to share their perspectives on the following three guiding questions: (1) What are the unique challenges that service providers and IPV survivors, as understood by service providers, in NWO have faced due to the implementation of emergency protocols during the COVID-19 pandemic? (2) How might public policy support IPV related organizations and the individuals that access their services in times of crisis such as pandemics? (3) What is needed in the development of inclusive, gendered, and equitable health policy and emergency protocols in times of crises? Semi-structured, in-depth interviews were conducted with five IPV service providers located in different communities across NWO. [...

A comparison and analysis of explainable clinical decision making using white box and black box models

Explainability is a crucial element of machine learning-based making in high stake scenarios such as risk assessment in criminal justice [80], climate modeling [79], disaster response [82], education [81] and critical care. There currently exists a performance tradeoff between low-complexity machine learning models capable of making predictions that are inherently interpretable (white box) to a human, and cutting-edge high complexity (black box) models are not readily interpretable. In this thesis we first aim to assess the reliability of the predictions made by black box models. We train a series of machine learning models on an ICU (Intensive Care Unit) outcome prediction task on the MIMIC III dataset. We perform a comparison of the predictions made by white box models and their black box counterparts by contrasting explainable model feature coefficients/importances to feature importance values generated by a post-hoc SHAP (SHapley Additive exPlanation) values. We then validate our results with a panel of clinical experts. The first study shows that both black box and white box models prioritize clinically relevant variables when making outcome predictions. Higher performing models showed prioritizations to more clinically relevant variables than lower performing models. The black box models show better overall performance than the white box models. [...

Fundamental studies of microalgal biofilm formation and microalgalbacterial membrane photobioreactors

Microalgae is one of the photoautotrophic microorganisms that has attracted significant attention in wastewater treatment and biofuel production. Although researchers claimed that microalgae cultivation in wastewater treatment has a very high potential for nutrient removal and economic benefit from downstream production, microalgae brought drawbacks such as extra cost and energy consumption due to diluted concentration, lower effluent quality because of suspended biomass, and risk of contamination by bacteria. Biofilm cultivation is considered an alternative to overcome the prementioned disadvantages. Furthermore, involving membrane technology in biofilm cultivation could further promote biomass harvesting efficiency and effluent quality. Thus, the new biofilm membrane bioreactors such as membrane carbonated microalgal biofilm reactor (MCMBR), and extractive membrane microalgal biofilm reactor (EMMBR) should have great prospects in sewage treatment. [...

Social-ecological resurgence through farmers’ traditional knowledge and agroecology in Pakistan

There is an urgent need to transform global food systems. Basic food supply chains have been disrupted due to the structural vulnerabilities within the dominant food system. Scholars, ecologists, smallholder farmers, economists and activists are increasingly advocating for agroecology as part of a path forward, emphasizing the importance of drawing on the latest agricultural research while harnessing farmers’ traditional knowledge to drive social-ecological resurgence. Farmers’ traditional knowledge is essential to agroecology and social-ecological systems. The basic understanding that humans are an integral part of the natural world, interwoven with the environment, rather than separate from it, is necessary for comprehending the complex relationships that rule our existence. This study focuses on Pakistan, an agricultural country, constantly influenced and pushed towards industrial agriculture. Industrial agriculture relies on high yielding variety seeds, synthetic fertilizers, and pesticides to boost food production. However, this approach has damaged the ability of farmers to depend on their local ecosystems for food. The research explores how traditional agroecological knowledge has been embraced as a form of social-ecological resurgence in Badin, Sindh, Pakistan. [...