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Recent Submissions

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Open Access
A Systematic Machine Learning-Based Investigation of Bloodstream Infection Biomarkers to Predict Clinical Outcome
(2024-04-16) Gilliland, Rory Lewis; MacDonald, M. Ethan; Lewis, Ian A.; Dingle, Tanis C.; Lee, Joon; Messier, Geoffrey
Bloodstream infections (BSI) represent a major burden on modern medicine, annually causing millions of cases worldwide with high mortality rates. Concerted efforts have been made in recent decades to improve BSI diagnostics to treat these dangerous infections more rapidly and precisely. However, these efforts have been hindered by an incomplete understanding of what factors make certain BSIs more severe than others. To address this shortcoming, this thesis applied statistical, machine learning, and epidemiological analyses to systematically investigate patient- and microbe-related traits as biomarkers of BSI clinical outcome. The analyses were facilitated by the Calgary BSI Cohort, a collection of over 35,000 BSI episodes detailing microbial genomic, proteomic, and metabolomic profiles linked to extensive patient medical records. Unsurprisingly, the results demonstrated that patient-related traits (e.g., age and comorbidity) are tightly linked to BSI clinical outcome. Patient mortality, hospital stay duration, and healthcare cost could all be predicted using patient features with areas under the receiver operating characteristic curve exceeding 0.80. Several microbe-related traits such as species classification and virulence factors were also found to be associated — albeit less strongly — with BSI patient mortality risk. Interestingly though, when patient- and microbe-related traits were combined, their predictive performance for BSI patient mortality did not surpass that of patient traits alone. Follow-up analyses revealed a compelling possible explanation: many “predictive” microbial traits may simply report the underlying characteristics of patients that tend to be infected by the pathogens carrying those traits. Taken together, the results suggest that patient-related traits are critically important as markers of BSI clinical outcome. Prompt development of formalized, patient-factor-based BSI risk stratification tools seems warranted to assist physicians in precisely identifying high-risk infections early in the clinical trajectory. In contrast, while microbial characteristics are invaluable for directing clinical therapy of BSIs, they provide little unique predictive information for BSI clinical outcome, making them unsuitable as biomarkers in the context of BSI risk stratification. Future research investigating the diagnostic relevance of the microbe should take great care to adequately correct for confounding patient dynamics.
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Open Access
Mapping the Unexplored Reactivity Landscape of Benzo[ghi]perylene
(2024-04-16) Hogan, David Thomas; Sutherland, Todd Christopher; Derksen, Darren; Heyne, Belinda; Thurbide, Kevin; Zhao, Yuming
This thesis describes the learning opportunities, failures, and successes surrounding a polycyclic aromatic hydrocarbon of interest, benzo[ghi]perylene. Neglected in the chemical synthesis literature but fundamentally interesting due to its composition and molecular symmetry, the work contained herein contributes a small work to a small field. The efforts are found in three chapters for three chronologically and ideologically related topics: the construction and optimization of a flow photoreactor to produce benzo[ghi]perylene; the exploration of structure and reactivity of benzo[ghi]perylene; the development of a strategy to improve the flow photochemical productivity of benzo[ghi]perylene.
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Open Access
Transitional Care for Type 1 Diabetes: The Certified Diabetes Educator Perspective
(2024-04-15) Rossiter, Brittany; dela Cruz, Aniela; Butalia, Sonia; Raffin Bouchal, Donna Shelley
Adolescence is a time when significant growth and development occur. Undergoing typical developmental transitions may include experiences such as academic pursuits, applying to post-secondary education, and striving for increased independence. Adolescents living with type 1 diabetes (T1D) will experience typical developmental tasks and manage an invisible life-threatening chronic disease that requires constant input and thoughtful choices in food, insulin dosing, and more. The transition of care from pediatric to adult diabetes clinics occurs during this fragile period in an adolescent’s life (Allen & Gregory, 2009; de Beaufort et al., 2010). Much research has involved adolescents undergoing transition, their families, and some healthcare provider (HCP) input. However, there is a notable lack of insight from registered nurses (RNs) working as certified diabetes educators (CDEs). RN CDEs are often highly trusted members of the diabetes team and have direct and extensive contact with patients, their families, and other HCPs. Using classic grounded theory methodology, a qualitative study was undertaken to understand the perspective of registered nurses working as certified diabetes educators on the transition of adolescents from pediatric to adult diabetes care programs. Seven CDE nurses from Calgary, Alberta were interviewed. Data analysis was completed using the constant comparative process, coding, and memo-writing. The core category and theory of Adaptation, with supporting categories of Loss, Embrace the New, and Red Tape emerged through analysis. Additionally, nurse participants discussed practical options for improving transitional care for adolescents, their families and healthcare providers in Calgary, Alberta.
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Open Access
Mobilizing Female Entrepreneurship Research to Inform Policy
(2024-04-15) Carlson, Jessica Lynn; Keyhani, Mohammad; Kano, Elena (Liena); Osiyevskyy, Oleksiy; Saunders, Chad; Huq, Jo-Louise; Musabende, Jacqueline
Gender and entrepreneurship scholars are increasingly called upon to consider policy implications in both identifying research questions and analyzing research results. Similarly, policy professionals are looking to inform policy with best available evidence. Yet, gaps between policy and gender and entrepreneurship scholars remain in both the availability of policy relevant academic research and the applied use of such research within policy domains. This dissertation represents an attempt to fill at least part of this gap by three diverse methods as represented in chapters two through four. Chapter two leverages qualitative methodology to a real-time policy problem and explores how women entrepreneurs experienced the impact of the COVID-19 pandemic to inform the development of specific policy supports. Chapter three leverages an application of the public organization management science approach to identify policy relevant research questions for gender and entrepreneurship scholars, alongside of a review of current literature. Chapter four advances a particular policy relevant research question of special relevance within the current Canadian context, the impact of institutional support, subnational variation and providing unpaid care on the choice to become an entrepreneur. Collectively, these papers aim to advance theory, policy, and practice in helping to close the gap between the academy and policy professionals. The main limitation of this thesis is scope, as the setting both academically and for policy is limited to Alberta. Despite this, the findings of from this thesis can be broadly applied to both theory and practice. Contributions include an increased recognition of who policymakers are and what they are looking for alongside of an extension to the institutional theory of gender inequality of entrepreneurial entry. Future research can further explore policy-relevant research questions such as implications of subnational variations in institutional context on entrepreneurship.
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Open Access
Incorporating the Concept of Distance into PageRank's Notion of Teleportation
(2024-04-15) Bowater, David William; Stefanakis, Emmanuel; Wang, Xin; Liang, Hung-Ling (Steve); Samavati, Faramarz Famil; Jabari, Shabnam
Centrality measures are a valuable tool for analysing complex networks because they help us to identify the most important or central nodes in a network. One of the most popular measures of centrality is PageRank which, despite being originally introduced for ranking web pages, has found widespread use in applications far beyond the web due to its simplicity and generality. However, in many real-world networks, the notion of teleportation is counterintuitive because it implies that whatever is moving around the network will jump or 'teleport' directly from one node to any other, without considering how far apart the nodes are. Therefore, the focus of this thesis is to incorporate the concept of distance into the notion of teleportation, which is accomplished by drawing upon recent advances in non-local random walks. First, an existing PageRank-based centrality measure is extended to improve its suitability for urban street networks. Then, a general measure of PageRank centrality is proposed which can be tailored for various real-world networks and applications. To evaluate the proposed measures, experiments on a variety of real-world spatial and social networks are performed. Finally, to improve our understanding of distance-based teleportation in real-world networks, an analysis of the effect of the damping factor on the rating and ranking of nodes is provided.