30921 research outputs found
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Dynamic data science applications in demand forecasting and finance
No full textThis thesis studies advanced statistical, machine learning, and deep learning methodologies for demand forecasting and financial risk management. In electricity demand forecasting, neural network autoregressive (NNAR) models are explored alongside a novel fuzzy two-step forecasting framework that integrates interval temperature forecasts to generate intelligent probabilistic electricity demand forecasts. In order to address nonlinear dynamics and long-term dependencies in demand data, deep learning architectures such as Long Short-Term Memory (LSTM) and Gated Recurrent Units (GRU) are implemented and evaluated.
In financial risk forecasting, neuro volatility models based on NNAR are used to forecast volatility directly. These models capture complex nonlinear structures, heavy tails, and volatility clustering, offering significant improvements over GARCH-type models. A key contribution is the introduction of data-driven kurtosis-dependent risk measures and data-driven exponentially weighted moving average (DDEWMA) covariance models, which enable robust portfolio optimization under heavy-tailed and high-dimensional settings. The thesis also proposes a direct efficient estimator of volatility based on estimating function theory. In empirical studies, neuro volatility models outperform existing models, particularly during market turbulence. Applications to cryptocurrency and stock portfolios reveal that the proposed approaches yield higher Sharpe ratios and reduced risk exposure. Collectively, these forecasting frameworks support more resilient decision-making in energy systems, financial risk management, and portfolio optimization.October 202
Back to humanity’s roots: taurodontism and root fusion in modern humans, Neanderthals, chimpanzees, and gorillas
No full textTooth roots remain understudied in palaeoanthropology relative to crowns, and yet molar roots exhibit a range of variability which may be taxonomically informative or may offer new insights into hominid evolution. This thesis explores variability in two root traits in modern humans, Neanderthals, chimpanzees, and gorillas: taurodontism, the relative expansion of the root body and/or pulp chamber and associated shortening of the root branches; and root fusion, the developmental contiguity of adjacent root branches which are typically separated. Three families of hypotheses are tested: differences in taurodontism between taxa; differences in root fusion between taxa; and associations between taurodontism and root fusion within taxa. Samples of computed tomography (CT) and micro-CT (µCT) scans of crania, mandibles, and individual teeth of modern humans, Neanderthals, chimpanzees, and gorillas were compiled from online repositories and by direct request to researchers. Taurodontism was recorded as the index of furcation depth to root length (furcation index); root fusion was scored according to a custom typology. Differences in furcation index were tested using PERMANOVA and Wilcoxon Signed-Rank tests; differences in root fusion were tested using Fisher’s Exact tests; associations between the two were tested using Mann-Whitney U-tests. Significant differences in furcation index were observed between taxa, and significant differences in root fusion frequency were observed between taxa at all positions except the lower first molar. Type of fusion differed significantly between taxa only in the upper first and second molars. No significant associations between furcation index and root fusion were observed within teeth or within molar rows. The results show that expression of furcation index and root fusion differ between hominid taxa, and therefore may prove useful for taxonomic assessment with continued research. Notable patterns of root fusion were observed, including the complete absence of mandibular molar root fusion in chimpanzees and gorillas, and the lack of diversity of fusion expression in gorillas, among whom maxillary root fusion is restricted primarily to one type. The conceptualization of taurodontism is discussed, and recommendations are provided for future research on the topic.October 202
Past & contemporary patterns of marine biodiversity: making inferences from anadromous sea lamprey population genomics & publicly archived genetic data
No full textMaintaining healthy oceans and the services they provide relies on safeguarding marine biodiversity. Genetic diversity is the foundation of biodiversity, underlying adaptive potential and population persistence, ecosystem resilience and stability. Planning for future genetic diversity conservation will be multifaceted. My thesis aims to uncover both patterns and drivers of global genetic diversity in marine fishes and the population genetics of a single species, taking a simultaneously global and single species approach to conservation genetics in the marine environment. I initially used a synthesis methodology, taking advantage of the large amount of publicly available genetic data. My aim was to determine global patterns of genetic diversity for marine fishes and their drivers. I found that global patterns of genetic diversity seemingly follow a west to east direction along global coastlines. I also uncovered human-caused declines in genetic diversity but not population differentiation. I detected variation in genetic diversity and gene flow levels connected to oceanographic parameters. I also found that species richness is correlated with higher genetic diversity, more genetically similar populations and lower effective population size. I then focused on a single species, anadromous sea lamprey Petromyzon marinus. The aim of my study was to apply a conservation genetics approach to this widely distributed species. As part of my study, I uncovered sea lamprey population genetic structure, status, demographic and evolutionary history, and likelihood of future maladaptation. I identified distinct sea lamprey management units across the species’ native range. I identified locations at which sea lamprey are vulnerable, both currently and under future climate change scenarios. I reconstructed deep demographic history and timed the split between sea lamprey populations on the two Atlantic coasts. I also uncovered that in recent evolutionary time, sea lamprey have faced population declines connected to human activity. My research has extended understanding of genetic diversity across global marine fish species, sea lamprey genetic structure, evolutionary trajectory and vulnerability across their native range. I interpret my results from a conservation genetics point of view, aiming to inform efforts for biodiversity conservation and show the importance in accounting for both the detail and the greater picture.University of Manitoba Faculty of Science Research Chair award to M.F.D., Faculty of Science Enhancement of Grant Stipends award to E.K.October 202
Accelerated multi-objective design optimization of MEMS using surrogate models
No full textThis study presents a comprehensive multi-objective optimization framework
specifically designed for micro-electromechanical systems (MEMS). The framework
integrates both traditional and adaptive optimization techniques, named
Surrogate-Assisted Multi-Objective Optimization (SAMOO) and Adaptive-SAMOO
(A-SAMOO), respectively. These optimization schemes were tested on multiple
MEMS devices with varying physics and complexities, demonstrating their
robustness and versatility, particularly in handling cases with discrete design
variables and strict objective constraints.
Additionally, the study addresses several shortcomings of traditional approaches
such as considering objective constraints and providing multiple design options for
users, which enhances the flexibility and practical application of the results. The
importance of preprocessing objectives is also emphasized. Results show that
adaptive optimization outperforms traditional offline methods, delivering a greater
number and higher quality of optimal solutions. This performance boost highlights
the advantages of online learning in enhancing the accuracy, speed, and diversity of
solutions in MEMS optimization. This detailed, step-by-step framework serves as a
valuable guide for researchers and practitioners looking to optimize MEMS designs
from scratch, offering a more reliable and effective approach to multi-objective
optimization in MEMS applications.February 202
Bridging the gap: measuring the impact of cancer patient navigation on time to CancerCare referral and first treatment for lung cancer
No full textBackground: Lung cancer is the leading cause of cancer deaths worldwide, due to advanced stages of disease at presentation. Healthcare systems are increasingly siloed, resulting in a myriad of care transitions that increase the complexity of care, often resulting in poor patient outcomes. Cancer patient navigation (CPN) emerged in Manitoba, as part of the province’s IN SIXTY initiative, with the general aim of guiding patients through the complexities of the healthcare system to reduce barriers to care, streamline services, and promote efficiencies. Since its inception over a decade ago, there has been no formalized evaluation of IN SIXTY and CPN in Manitoba.
Purpose: The aim of this thesis was to measure the impact of CPN in Manitoba on supporting patients with primary lung cancer in achieving timely referral to CancerCare Manitoba (CCMB) and first treatment.
Methods: A retrospective, cohort study of Manitoba Cancer Registry and Aria data was completed to compare patients who received care from a nurse navigator as part of CPN to patients who received standard care, on the number of days from lung cancer diagnosis to CCMB referral, and date of first treatment, using multilinear Cox proportional hazards regression analysis.
Findings: Patients who received CPN, actualized by nurse navigators, had a statistically significant reduced number of days from lung cancer diagnosis to referral receipt at CCMB, and to the date of first treatment. The timing of CPN, which was found to occur at different points along the cancer continuum, was also found to affect the degree to which CPN impacted timely lung cancer care. CPN implemented prior to lung cancer diagnosis was found to be the most effective model of care.
Conclusion: CPN is an effective, nurse-led, model of care, that shortens the time to CCMB referral and first treatment for lung cancer. Further research is needed regarding its impact in other disease sites, and during the suspicion-interval of newly suspected cancer.February 202
Soil productivity and soil health status following reclamation of pipeline corridors on agricultural land
No full textUnderground pipeline construction on cropland can reduce crop productivity on the pipeline rights-of-way (ROWs). There is a dearth of information on the recovery of soil productivity with increasing time since reclamation (TSR) of ROWs on cropland. Therefore, the objective of this study was to determine the effect of TSR on the recovery of soil properties and crop yield on underground natural gas pipeline ROWs. We used field and laboratory studies to examine changes in soil properties and soil productivity with increasing TSR. A growth room bioassay using soils collected from ROWs with TSRs of 4 and 10 yr examined the response of ROW soils to fertilizer application in the absence of an operating underground pipeline. Results showed detrimental impacts of the pipelines on soil health and soil productivity, with grain yields 42% lower on the ROWs than on the off-ROWs, even 12 yr after ROW reclamation. Permanganate-oxidizable carbon and autoclaved-citrate extractable protein levels on ROWs approached those on the off-ROW by year 12 following ROW reclamation, while soil respiration (24-h CO2 burst) recovered within 6 yr of reclamation. Soil penetration resistance in the 20- to 40-cm depth interval was 58-64% greater on the 4.5-yr ROW than on the off-ROW. Saturated hydraulic conductivity was three to four times lower on the 4.5- and 6.5-yr ROWs than on the off-ROW. Effective water conductive macroporosity was 73% lower on the 4.5-yr ROW than on the off-ROW. Six years post-reclamation, the diversity of bacterial and fungal communities on two of the three sites was still lower than on the off-ROW. Nonetheless, all soil and crop attributes showed a steady but slow improvement with increasing TSR. Contrary to the limited crop response to incremental fertilizer rates in the field study, the growth room bioassay showed a significant biomass yield response to increasing fertilizer rates. These results suggest that persisting crop yield losses observed in the field could be due to the presence of active pipelines. Findings from this research will assist in the formulation of guidelines for pipeline ROW reclamation and the development of land management strategies for the successful restoration of ROW soil productivity.February 202
Investigating the soundscape ecology of Tremblay Sound, Nunavut
No full textThe soundscape is a critical part of marine mammals’ habitat and provides insights into the health of the ecosystem. Arctic soundscapes are experiencing large changes due to reducing sea ice extent, shifting marine mammal distributions, and increased anthropogenic activity, including shipping traffic. As marine mammals rely on sound for communication, navigation, foraging, and detecting predators and prey, understanding how soundscapes are shifting is crucial to conserving arctic marine ecosystems. Soundscape ecology provides a non-invasive and cost-effective way to understand current arctic marine environments and how they are shifting over time. This study investigates the soundscape ecology of Tremblay Sound, Nunavut, an important summer habitat for narwhal located within the Tallurutiup Imanga National Marine Conservation Area. This study examined the seasonal patterns of the soundscape using passive acoustic recordings from July 2017 to July 2019. Sound pressure levels were highly tied to sea ice conditions with the quietest periods observed just after sea ice formation in Ukiaq (Fall) and just before sea ice breakup in Upirngaaq (Spring). In Ukiaq (Fall), Ukiuq (Winter), and Upirngassaaq (Early Spring) the soundscape is driven by tidal collisions of the land fast sea ice. Sound pressure levels were greatest during Aujaq (Summer). The Aujaq (Summer) season was investigated further using four hydrophone sites during the 2017 and 2018 summers. The Aujaq (Summer) soundscape is driven by geophony (e.g., wind speed, sea ice) and biophony from narwhal vocalizations. However, biophony contributions were lower in 2018 due to a dramatic decline in narwhal vocalizations, with vocalizations reaching 14,120 detections a day in 2017, compared to just 1,135 a day in 2018. In 2018, reduced narwhal sightings were reported by community members in Mittimatalik, suggesting potential shifts in narwhal habitat use. These findings provide essential benchmarks for future acoustic monitoring and highlight the need for further studies to understand how changing soundscapes may impact marine mammal behavior and habitat use amidst ongoing environmental shifts in the Arctic.ArcticNet.
EarthRangers
University of ManitobaFebruary 202
Comparative study on nutritional characteristics and physicochemical properties of ancient wheat species
No full textBackground & objective: Ancient wheat species, such as einkorn, emmer, and spelt, are gaining increased attention due to their environmentally friendly nature, which aligns with sustainable agriculture practices, and the rising consumer demand for nutrient-dense food options. Despite their growing recognition, the full potential of these ancient wheat remains largely unexplored, hindering their future food applications. Therefore, this study aimed to address this gap by comprehensively evaluating the nutritional profiles and physicochemical properties of einkorn, emmer, and spelt in comparison to common hexaploid Canada Western Red Spring (CWRS) wheat.
Methodology: Nutritional characteristics were assessed through analyses of proximate composition, amino acid profile, phenolic acid content, and in vitro starch and protein digestibility (IVPD). Physicochemical properties were evaluated with a particular focus on the starch and protein profiles of these species.
Findings: Einkorn demonstrated higher protein content (21.27%) and phenolic acid content (both free and conjugated), along with lower starch levels compared to other wheat species. Spelt had the highest bound phenolic acid content. In terms of starch digestibility, einkorn was characterized by lower glucose release and reduced rapidly digestible starch (RDS) levels, while refined common wheat (CWRS RF) exhibited the highest RDS and glucose release. Among the ancient wheat species, emmer had the highest glucose release and RDS content. IVPD was highest in CWRS RF (86.05%), with einkorn following closely at 84.29%, while spelt and emmer exhibited lower IVPD values. Lysine was the limiting amino acid in all wheat species. Thermal behavior revealed that spelt had the highest thermal stability with high transition temperatures, while emmer required less energy for gelatinization. Amylose% and amylopectin% showed no significant differences among wheat species. Protein composition analysis indicated significant variations in ancient wheat species, specifically, SDS unextractable glutenin levels were significantly lower in the ancient wheat species compared to common wheat suggesting potential challenges for breadmaking.
Conclusion: This study highlights the nutritional significance of ancient wheat species, particularly einkorn, showcasing its potential with higher levels of protein, phenolic acids, and a low-glycemic food profile, along with substantial IVPD. The unique physicochemical characteristics, suggest that processing modifications may be required to optimize the use of ancient wheat in bakery applications.May 202
Transnational circuits of precarity: a qualitative examination of temporary worker wellbeing in Manitoba
No full textABSTRACT
Background
In western Canada, Manitoba is a critical hub for a large population of migrant workers. Usually with limited English or French language ability and possessing limited rights and protections under the current TFWP, Temporary foreign workers (TFWs) are often tied to a single employer, leaving them vulnerable to employer abuse and the under-reporting of workplace injuries and illnesses due to the threat of deportation. Within the context of the COVID-19 pandemic, when my dissertation research began, the many cases seen among TFWs in Manitoba raises additional important public health questions on the health and wellbeing of migrant workers in Manitoba that I discuss in this dissertation.
Methodology
In close collaboration with Migrante Manitoba (MB), I conducted a qualitative study to explore the precarious lives of migrant workers during the COVID-19 pandemic. I virtually interviewed 20 migrant workers who entered Canada through the TFWP, employed either as seasonal agricultural workers (n=7) or TFWs (n=13). Thirteen TFWs came from Philippines and seven farmworkers from Mexico (n=6) and Jamaica (n=1).
Theoretical contribution
I developed the notion of transnational circuits of precarity to understand the multiple temporal-spatial layers of precarity that migrant workers encounter along their journeys to Manitoba. This multivalent concept is comprised of the following interconnected pieces: 1) a broader political economic “force-field” that compels the movement of human labour resources from the global South to the global North; 2) the rigid and regulated pathway put in place to ensure workers arrival at their work destinations; 3) the process of making “model minorities” through training programs that ensure the “smooth” transition of workers in their host country; and 4) the affective economy that is fueled by workers’ hopes, dreams, and desires. All together, these seemingly disparate processes articulate to produce complex temporal and spatial realities that shape the precarious trajectories of migrant workers. Such a paradigm shift away from the narrow temporal and spatial limits of a focus on “occupational health hazards” will be critical if workers are to realize any meaningful and substantive changes to their overall physical and mental well-being.May 202
Ageism in Manitoba workshop summary
Get PDFAs part of the Centre on Aging’s outreach to bring awareness of issues faced by older people in the Province, the Centre hosted a half day workshop on January 23, 2019 that focused on ageism in Manitoba.
Over 70 participants took part in this event where ageist stereotypes in society were examined, and participants were asked to reflect on their own internal ageist ideas. A short presentation given by Centre Director Dr. Michelle Porter, outlined the existing definitions in the academic literature and from international organizations (e.g., World Health Organization) on ageism, discussed the effects, and looked at ways to reduce ageism in society.
Several group and individual activities required participants to think of and identify examples of ageism; what actions can be taken; and discuss what specific types of strategies or activities/programs could be studied in Manitoba.
This document provides a brief synopsis of the individual and group activity reporting