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Grey wolves (Canis lupus) shift selection of anthropogenic landscape features following predator control in the Nearctic boreal forest
No full textConserving endangered species sometimes involves killing their predators. In the case of Nearctic wolves (Canis lupus), rarely are lethal control measures examined for ancillary effects on predator behaviour or community responses in a before-after design. We examined wolf relative abundance and spatial distribution in a northwestern boreal forest landscape for three years before and after the onset of wolf culling intended to conserve threatened woodland caribou (Rangifer tarandus caribou). We hypothesized that wolf occurrence would increase with density of anthropogenic features created by landscape development before the cull, but that wolves would avoid anthropogenic features after the cull due to associated mortality risk. We used generalized linear models in an information-theoretic framework to weigh evidence for our hypotheses. Post-control, independent wolf detections decreased to 24 % of pre-cull numbers, but wolves maintained 75 % of their distribution. Pre-control, wolves were positively associated with linear features, presumably for hunting efficiency, but post-cull wolves were negatively associated with these features. Thus, wolf control caused not only a numerical reduction of wolf numbers, but also a functional change in wolf behaviour that could further reduce predation pressure on caribou. However, post cull wolf occurrence was more strongly associated with anthropogenic block features which provide forage for alternate prey, potentially subsidizing their fast recovery. Conservation actions involving predator mortality alter landscape-scale distributions and behaviors of surviving predators, with potential indirect effects for the mammal community.This work was funded by Alberta Environment and Protected Areas, InnoTech Alberta, Alberta Innovates - Land and Biodiversity Program, Alberta Upstream Petroleum Research Fund, MEG Energy, Mitacs Canada (KBD), University of Victoria (KBD), and Oil Sands Monitoring Program (JTF).FacultyReviewe
Writing & power: Positions and policies for social change
No full textWriting & Power: Position and Policies for Social Change is funded by the Social Sciences and Humanities Research Council in partnership with Canadian Heritage. Rédaction et Pouvoir: Positions et Politiques pour le Changement Social est financé par le Conseil de recherches en sciences humaines en partenariat avec Patrimoine canadien.Facult
Changes in aerosols and clouds following a rapid reduction in emissions: case studies from the COVID-19 pandemic
No full textThis thesis explores the uncertainties in several key aerosol- and cloud-related fields. Although the three projects described here investigate different topics, they are united by a common theme: how well do we understand the impacts of potential changes in emissions?
The first two science chapters revolve around the COVID-19 pandemic and associated changes in anthropogenic activity. Each of these chapters asks two questions. First, did the emissions change in question lead to a statistically significant anomaly in satellite observations of relevant fields? And second, how well do current models reproduce the observed changes?
The first of the COVID-19 chapters explores the impact of reduced aviation on cirrus cloud. Aviation-induced cirrus is the largest source of uncertainty in, and by some estimates may be the largest component of, aviation's net radiative forcing. Despite a sustained global reduction in air traffic, with April 2020 flight numbers less than 40% of their 2019 levels (FlightRadar24, 2020c), aviation-weighted cirrus coverage was not significantly reduced in Spring 2020. A regression model based on the contrail cirrus simulations of Bock and Burkhardt (2016a) did not exhibit a statistically significant dependence of cirrus anomalies on aviation intensity, and suggested that current models may overestimate the impacts of aviation on cirrus. We apply these results to calculate the first observationally constrained estimate of the radiative forcing of aviation-induced cirrus: (-3, 22) mW/m2, much lower than but consistent with the current best estimate of 57 (17, 98) mW/m2 (Lee et al., 2021).
The second of the COVID-19 chapters explores the impact of reduced aerosol emissions on aerosol optical depth (AOD). Of the regions considered, only India experienced statistically significant reductions in total or dust-subtracted AOD. Earth system model simulations from the CovidMIP experiment over-predict the magnitude of the Spring 2020 total and dust-subtracted AOD anomalies, but this bias can be attributed in part to biases in the model inputs. Through a series of sensitivity tests we demonstrate that, given sufficiently accurate inputs, Earth system models can reproduce the observed total and dust-subtracted AOD anomalies to within observational uncertainty. These results provide confidence in the ability of Earth system models to predict the large-scale aerosol responses to other emission scenarios as well.
The final science chapter of this thesis assesses the sensitivity of black carbon's (BC's) simulated climate impacts to the choice of its refractive index, which determines the extent to which BC absorbs or scatters radiation. We compare ensembles simulated with three values of the refractive index that are commonly used in the climate modeling community. Increasing from low to high absorption can increase simulated global-mean absorbing aerosol optical depth (AAOD) by 42% and effective radiative forcing from BC-radiation interactions (BC ERFari) 47%. The AAOD increase is comparable to that from recent updates to aerosol emission inventories, and in BC source regions, a third as large as the difference in AAOD retrieved from different satellites. The BC ERFari increase is comparable to the scale of the uncertainty in recent literature assessments. Although model sensitivity to the choice of BC refractive index is modulated by other parameterization choices, our results highlight the importance of considering refractive index diversity in model intercomparison projects.Graduat
Social media perspectives on Chinese and Japanese housewives: Women at the intersection of patriarchy and feminism
No full textThis research project delves into the intersection of patriarchy and feminism in Chinese and Japanese societies by analyzing mainstream social media content. The study investigates societal attitudes toward housewives, focusing on how these perceptions are shaped and reflected on online platforms. By conducting a primary source survey, the research examines the portrayal of housewives in Chinese and Japanese social media, uncovering divergent perspectives and societal norms regarding this role. In China, housewives are often subject to pessimistic and unsupportive views, seen as perpetuating women's oppression within a patriarchal system. In contrast, Japanese attitudes towards housewives are more neutral and accepting, with criticism centered on personal values rather than societal condemnation. The research highlights the complexities of gender dynamics and feminist discourse in East Asian societies, shedding light on the varied experiences and perceptions of housewives in different cultural contexts. However, the study acknowledges the limitations of analyzing social media data, including potential biases and the influence of political and demographic factors on online discourse.Jamie Cassels Undergraduate Research Awards (JCURA)UndergraduateReviewe
Usability evaluation ecological validity: Is more always better?
Get PDFBackground: The ecological validity associated with usability testing of health information technologies (HITs) can affect test results and the predictability of real-world performance. It is, therefore, necessary to identify conditions with the greatest effect on validity. Method: We conducted a comparative analysis of two usability testing conditions. We tested a HIT designed for anesthesiologists to detect pain signals and compared two fidelity levels of ecological validity. We measured the difference in the number and type of use errors identified between high and low-fidelity experimental conditions. Results: We identified the same error types in both test conditions, although the number of errors varied as a function of the condition. The difference in total error counts was relatively modest and not consistent across levels of severity. Conclusions: Increasing ecological validity does not invariably increase the ability to detect use errors. Our findings suggest that low-fidelity tests are an efficient way to identify and mitigate usability issues affecting ease of use, effectiveness, and safety. We believe early low-fidelity testing is an efficient but underused way to maximize the value of usability testing.This research was funded by the French Agence Nationale de la Recherche (grant number: ANR-15-CE36–0007).FacultyReviewe
Spatial and Seasonal Variability in Eukaryotic Phytoplankton Composition in the Arctic Ocean Revealed with Metabarcoding Analysis
No full textRapid environmental shifts in the Arctic Ocean have brought increased attention to its biodiversity. Environmental changes in the Bering and Chukchi Seas are especially concerning, as these regions are among the most productive in the world’s ocean, and their fisheries contribute to both local and global food systems. Predicting the impacts of climate change requires understanding biodiversity at the base of the food web, including eukaryotic phytoplankton, and the environmental drivers affecting them. This study evaluated the variability in the structure of phytoplankton communities at spatial and inter-annual scales (2021 and 2022) in the Bering and Chukchi Seas in the Pacific Arctic Region, and at a seasonal scale (September 2019 to July 2020) in Cambridge Bay in the Canadian Arctic using metabarcoding of the V4 18S rRNA gene. The community structure of eukaryotic phytoplankton exhibited both strong spatial and temporal trends, and was influenced by temperature and nutrient concentrations, as well as by sea ice extent and thickness in the Pacific Arctic Region. The chain-forming diatoms Chaetoceros and Thalassiosira were responsible for the high phytoplankton biomass of this region and were associated with temperatures below 1 degree C, and high nitrate concentrations, aligning with previous observations. The community composition also varied from year to year, with the picoprasinophyte, Micromonas, and the prymnesiophyte, Phaeocystis, contributing to a larger proportion of the overall phytoplankton community, particularly in surface waters, in 2022 compared with 2021. In addition, several potentially toxigenic algae, including Alexandrium, Aureoccocus and Pseudo-nitzschia were present in the Pacific Arctic Region and were generally associated with warmer temperatures. In Cambridge Bay, there were distinct seasonal changes in phytoplankton community structure, including a polar winter community dominated by dinoflagellates, a spring under ice community dominated by Phaeocystis, and a late spring/summer community composed largely of Micromonas with an increase in Chaetoceros by July with the onset of sea ice melt. Ultimately, findings from this work add to the growing body of knowledge on phytoplankton community structure in dynamic Arctic icescapes. Findings from metabarcoding analysis in the Pacific Arctic Region corroborate previous observations that diatoms are driving the phytoplankton biomass in July and provide a higher resolution of their taxonomic placements. The year-long investigation in Cambridge Bay indicates that continuous sampling strategies capture finer scale variation in phytoplankton community structure that was lacking from our Pacific Arctic interannual dataset. These types of sampling strategies should be incorporated to monitor other productive and vulnerable Arctic Regions.Graduate2025-04-0
Spectrums of legal design: Navigating methods and ethics in practice
No full textThis is the first talk of the Legal Design SeriesIn this talk, we'll explore the diverse range of design methods available within the legal domain, focusing on how these approaches can address complex challenges. Drawing on examples from my work at Portable and other projects, we will discuss how legal design operates across different spectrums—from traditional to innovative methods—and how ethical considerations are woven into these practices. Through this exploration, we’ll examine the critical role that ethics plays in shaping effective, meaningful legal design solutions.UVic Graduate Student Law & Society Research GroupGraduateUnreviewe
The problem of low fertility in South Korea
No full textSince 2005, the South Korean government worked to address the declining total fertility rate by enacting pronatalist policies. Despite these efforts, the country continues to experience one of the lowest total fertility rates in the world. This study draws on data from Statistics Korea, the Organisation for Economic Co-operation and Development (OECD), and several articles on low fertility rates and childcare in South Korea to assess whether the pronatalist policy introduced in 2021 could yield the desired outcomes for the government. The findings indicate that the government overlooked the interplay between culture and economic decisions. With the cultural norms of placing children in private education and expectations of women to drop out of the labour market after childbirth, the policy from 2021 does not address the rising costs of private education and opportunity costs for women, contributing to lower fertility. The South Korean government understands the impact of a prolonged low total fertility rate due to problems in areas like the public pension system. While multiple factors exist that influence the total fertility rate in South Korea, the research highlights the importance of policymakers acknowledging the interplay between culture and economic decisions.Valerie Kuehne Undergraduate Research Awards (VKURA)UndergraduateReviewe
Generation of Novel Wavelet Transformations towards applications in Tensor Network Algorithms
Get PDFWavelets can be formulated in a pyramidal gate structure of unitary rotation matrices which satisfy a set of vanishing moment equations. The vanishing moment equations can be satisfied by passing them into a cost function and minimizing with the Nelder-Mead algorithm. Barren plateau-like features exist in the solution-space of the vanishing moment equations which make it difficult to solve for greater circuit depths. The basins of these barren plateaus can be widened by introducing a parameter, β, in the exponent of each vanishing moment equation for a given circuit.
Wavelets up to depth 3, β=1, are generated to high precision and shown to match the known Daubechies wavelets. Solutions to the altered vanishing moment equations are shown to exist on a continuum for a domain of β-values for the depth 2 circuit.
An improved algorithm for solving for wavelet circuits of greater depths is proposed. These wavelets will be used in the multi-scale entanglement renormalization ansatz (MERA) tensor network algorithm to solve for the ground state energy of gapless systems.Jamie Cassels Undergraduate Research Awards (JCURA)UndergraduateReviewe
Mitigating variability of energy demand and supply in highly decarbonized energy systems
Get PDFTransitioning towards sustainable energy systems requires elimination of greenhouse gas emissions associated with end-use energy demands and electricity generation. Electrification of end-use demands that traditionally use fossil fuels and expanding variable renewable energy generation are considered key strategies in achieving emission reduction targets. This dissertation investigates end-use electrification and renewable supply impacts on future electricity system infrastructure. Three studies analyze demand- and supply-side transition options for the province of British Columbia, Canada.
The first study investigates building heat electrification impacts on capacity and flexibility requirements of the electricity grid in British Columbia. Energy demands are projected for 2050 considering variations in building stock evolution, building code implementation strategies, and building envelope efficiency improvements. Varying shares of heat pump penetration rates can be applied using hourly temperature-dependent COP profiles. This study examines the shape and magnitude of peak electricity demands and ramping requirements for electrified heating by computing regional end-use energy demand profiles for space and water heat in British Columbia’s residential and commercial building sectors. Results show that with an emphasis on building stock improvements, 90% heat pump penetration leads to an increase in electrical energy of 6% despite an annual population growth rate of 1.1%. The impact of high heat pump penetration rates on capacity requirements is significantly larger, with an increase of 37% in peak electricity demand for a 90% heat pump penetration rate. However, results of this study show that building energy codes and retrofit rates contribute relatively little to achieving net-zero emissions in the building sector.
The second study provides a more comprehensive analysis of end-use electrification by combining the electrification of building heat with electrification of space cooling and road transportation to examine changes in capacity and flexibility requirements for British Columbia’s electricity grid. Two high-resolution demand simulation models are introduced that project electricity load curves for electrified end-uses in the building and road transportation sectors. Electric vehicle charging and space heating control are introduced as demand-side management strategies to examine the effect of load reduction and load shifting on capacity and flexibility requirements. In this work, building demands are modelled in hourly resolution and transportation demands are modelled in 15-minute time-steps. The shape and magnitude of peak electricity demands, range of electric loads, and ramping requirements are examined for a simultaneous electrification of 10 end-uses in varying temporal resolution. Results show that capacity and flexibility requirements increase by up to 93% and 320%, respectively, where future ramping requirements are largely driven by electrification of road transportation. Utilizing electric vehicle charging and space heating control reduces the increase in capacity and flexibility requirements by 19% and 238%, respectively, while shifting the timing of the peak event to early morning hours. Temporal resolution of demand models is an important determinant of flexibility requirements, leading to an increase of 520% when changing from an hourly to a 15-minute resolution.
The third study assesses the duration and magnitude of periods with excess energy generation and energy deficiency in British Columbia’s energy system by 2050 where building heating, cooling, and road transportation is electrified using a portfolio of renewable energy sources. Future net load which is defined as the difference between electricity demand and variable renewable energy generation is determined to investigate dispatchable capacity requirements. The study examines net load for installed wind and solar capacities up to 50 GW for three wind penetrations. Three water supply scenarios are tested to identify changes in net load due to drought conditions and increased precipitation impacting hydroelectric power generation, an important consideration in hydro-dominant electricity systems. A one-year production cost model is used to quantify surplus energy and energy deficiency for a range of variable renewable supply scenarios. Results show that peak net load in 2050 will exceed present-day peak electricity demand in British Columbia, when building and road transportation end-uses are electrified, thereby necessitating built-out of variable renewable energy generation capacity. Individual hours of energy deficiency can be avoided with demand-side management or import of electricity from neighbouring systems. For an installed capacity of 30 GW, energy storage with a duration of 5 hours would enable system operators to manage most deficiency periods for all supply scenarios. A combination of large-scale built-out of variable renewable energy generation and short-duration energy storage can increase operational flexibility to meet growing electricity demand in 2050 after end-use electrification of building heating, cooling, and road transportation.Graduate2025-02-2