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Re-Os chronology of critical minerals: applications to hydrothermal graphite and nickeline in 5-element ore veins
No full textCritical metals like graphite and nickel are becoming increasingly important in the context of the global transition to green energy, yet the geological processes responsible for their formation remain poorly constrained in many deposit types. This thesis applies rhenium-osmium (Re-Os) geochronology to two critical mineral systems—hydrothermal graphite and nickeline (NiAs) in 5-element veins—to evaluate their suitability as geochronometers and to improve genetic models of ore formation. The first case study targets the high-grade Amitsoq graphite deposit in South Greenland, which is hosted within the Paleoproterozoic Ketilidian Mobile Belt. Re-Os dating of two graphite samples yields an isochron age of ca. 1645-1677 Ma with initial 187Os/188Os ratios between 1.309-1.348, suggesting late- to post-tectonic mineralization associated with retrograde fault reactivation. These results support a growing body of evidence indicating a unique period of global-scale graphite formation during late-stage orogenic events associated with the assembly of the supercontinent Nuna in the Paleoproterozoic.
The second case study explores the viability of nickeline as a Re-Os chronometer through analysis of samples from 5-element veins in the Northwest Territories, Canada. Despite its abundance in 5-element vein systems, nickeline Re concentrations are generally low (0.11-3.07 ppb) and yield model ages with high scatter, suggesting a high susceptibility to whole or partial Re-Os disturbances. Further, nickeline exhibits a tendency to contain micro-inclusions of phases with a high affinity for Re that dominate Re-Os systematics. These results overwhelmingly demonstrate that nickeline is not a reliable host for Re-Os dating. However, associated minerals such as gersdorffite yielded more geologically plausible model ages, dating 5-element vein mineralization at Eldorado mine, N.W.T., Canada to ca. 1712 and 1523 Ma, following two major intrusion episodes with spatial association to the 5-element mineralization. The older age of ca. 1712 Ma constrains uraninite mineralization to have occurred within 30 Ma of the later arsenide mineralization, suggesting a much closer link between the two distinct styles of mineralization than previously thought
Alexandra Albers - Abstract 41 - Innovate Conference 2025
No full textMental health concerns, including symptoms of anxiety and depression, are prevalent for
people receiving dialysis. Nine Community Advisors, people with lived experience of kidney failure in
Alberta, identified the need for a patient-facing version of a mental health pathway for Albertans receiving
dialysis
Assessing the RETREAT Score for Hepatocellular Carcinoma Patients in a Liver Transplant Program Guided by Total Tumour Volume Criteria
No full textPurpose:
Liver transplantation (LT) is a curative option for hepatocellular carcinoma (HCC), but optimal
candidate selection remains a challenge. The Total Tumour Volume (TTV) criteria allow for
broader eligibility compared to the more commonly applied Milan criteria. The Risk Estimation
of Tumour Recurrence After Transplant (RETREAT) score was developed within Milan-based
programs to estimate post-LT recurrence risk; however, its performance in TTV-based LT
settings is not well established. This study aimed to assess the predictive value of the RETREAT
score in a TTV-based LT program.
Methods:
A retrospective cohort analysis was performed on 302 patients who underwent LT for HCC at
the University of Alberta. Data collected included patient demographics, tumour characteristics,
alpha-fetoprotein (AFP) levels, microvascular invasion status, and recurrence outcomes.
RETREAT scores were calculated based on tumour size, number of tumours at explant, AFP
levels, and presence of microvascular invasion. Statistical analyses comprised Kaplan–Meier
survival estimates and discrimination testing using the C-statistic.
Results:
Among the 302 patients included, the median follow-up was 6.3 years, during which 37 patients
(12.2%) experienced HCC recurrence. Recurrence rates at 1, 2, 3, and 5 years were 1.6%, 6%,
8%, and 13%, respectively. Recurrence rates by RETREAT score were as follows: 1% (score 0),
4% (score 1), 19% (score 2), 12% (score 3), 28% (score 4), 67% (score 5), 28% (score 6), and\n100% (score 7). The C-statistic for recurrence prediction was 0.786 for RETREAT, compared
with 0.660 for Milan criteria and 0.719 for TTV.
Conclusion:
The RETREAT score demonstrates strong predictive accuracy for recurrence in a TTV-based
LT program, supporting its value in identifying patients at higher risk of post-LT recurrence
A Hybrid Approach to Pavement Performance Prediction in Cold Regions: Machine Learning and Falling Weight Deflectometer Analysis
No full textCold region pavements are subjected to extreme environmental conditions, including prolonged
periods of low temperatures and repeated freeze-thaw cycles. These harsh conditions accelerate
pavement deterioration, leading to an increase in maintenance requirements and significantly
higher rehabilitation costs. To address these issues and explore the potential application of
sustainable waste materials in pavement design, the Integrated Road Research Facility (IRRF) test
section was constructed in Edmonton, Alberta, in 2012. This test section was specifically designed
to incorporate sustainable materials, such as bottom ash, polystyrene, and tire-derived aggregates,
to reduce environmental impact and enhance pavement durability. Environmental sensors were
embedded into the pavement to monitor its performance. However, due to sensor malfunctions
over time, the need for enhanced monitoring led to the construction of a new test section in 2022,
featuring upgraded instrumentation to ensure improved data accuracy and reliability.
This study focuses on temperature data collected from the new test section between June 2023 and
December 2024, specifically examining the effects of temperature fluctuations on pavement
performance. Using novel machine learning models, this research aims to predict key parameters
such as frost depth penetration, as well as the duration and timelines of freeze and thaw cycles, A
multi-depth prediction approach was employed to compare both holistic and multi-depth
temperature variations from June 2023 to December 2024, ensuring highly accurate insights into
the environmental impacts on pavement structures. By incorporating data for the full unbound
pavement layers, this approach enhances the predictive capability of the model, providing more
detailed insights into temperature variations at multiple depths within the pavement.
To assess the long-term performance of the entire test section, including both the insulation layer
and tire embankment sections, Falling Weight Deflectometer (FWD) testing was performed in
2015 and 2024. The decade-long comparison of changes in pavement dynamic modulus shows
long-term durability and structural behaviour of the pavement.
The findings of this study confirm the effectiveness of machine learning models in accurately
predicting temperature variations within pavements, a key factor in optimizing pavement design
and maintenance strategies. Additionally, the integration of sustainable materials into the test section demonstrates their potential to significantly improve pavement resilience in response to
climate change. The results highlight the importance of utilizing innovative materials and
advanced modeling techniques in developing adaptive and sustainable pavement management
practices. These findings will contribute to more efficient, durable, and environmentally-friendly
pavement infrastructure, paving the way for the future of cold-region construction
The (Dis)empowerment of Disabled People through Paralympic Hosting: Postcolonial Lessons from South Korea
No full textSSHRC IDG awarded 2025: This project develops a postcolonial disability justice analysis of the 1988 Seoul Paralympic Games, challenging dominant claims that the Paralympics automatically empower disabled people in non-Western host countries. Focusing on South Korea as an intrinsic case study, the research aims to: (1) compare Western and South Korean narratives about the Games’ legacy; (2) provide a more historically grounded account of why South Korea hosted the Paralympics; and (3) center the often-overlooked perspectives of South Korean Paralympians and disability activists. The 1988 Games are widely described as a turning point, but in different ways. The International Paralympic Committee (IPC) celebrates them as the first “modern” Paralympics, marked by greater Olympic alignment and a shift toward sport and international disability empowerment. The South Korean government portrays the Games as a milestone in national disability welfare. In contrast, disability activists argue that the Games did not significantly improve rights, inclusion, or opportunities for disabled people, despite increased public visibility and activism. Using three datasets—(1) official legacy claims from organizers and the IPC, (2) scholarly and archival historical records, and (3) interviews with 15–20 disabled South Koreans (half 1988 Paralympians and half activists)—the study employs constructivist thematic analysis and cross-dataset comparison to produce a nuanced account of disability legacies. Building on strengths in Paralympic studies, critical disability studies, and postcolonial sport studies, the project makes a novel interdisciplinary contribution. Beyond academia, it seeks to amplify marginalized Korean disability voices, disseminate findings in accessible Korean-language formats, and inform more equitable, participatory, and culturally specific approaches to future global parasport events
Project 38: Spatial Updating in Mixed Reality: from Environment-Stabilized to Body-Stabilized Process
No full textEmotions in assessment network analysis
No full textThis the third of a series of Research Briefs created from the Intrinsically Motivating Assessment Practices (iMAP) project. It is from data collected in Fall 2024
Insight into government, June 6, 2025
No full textAlberta's independent newsletter on government & politics