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Cavity optomechanical oscillation locking
No full textOptical microcavities have emerged as powerful tools for detecting single molecules and nanoparticles due to their exceptional sensitivity and label-free operation. However, the performance of ultra-high-Q microcavities is highly sensitive to factors such as ambient temperature fluctuations, mechanical vibrations, and laser frequency drifts, all of which destabilizing laser-cavity detuning and intracavity power. Optomechanical oscillation (OMO), a phenomenon driven by radiation pressure within the cavity, offers significant advantages for liquid-based sensing, but requires stringent conditions stable laser-cavity detuning for sustainable regenerative operation. In this thesis, we demonstrate stable, long-term OMO in an aqueous environment by implementing a Proportional-Integral (PI) lockingGraduate2025-12-1
In vitro and in vivo synergetic radiotherapy with gold nanoparticles and docetaxel for pancreatic cancer
Full text linkThis research underscores the potential of combining nanotechnology with conventional therapies in cancer treatment, particularly for challenging cases like pancreatic cancer. We aimed to enhance pancreatic cancer treatment by investigating the synergistic effects of gold nanoparticles (GNPs) and docetaxel (DTX) as potential radiosensitizers in radiotherapy (RT) both in vitro and in vivo, utilizing a MIA PaCa-2 monoculture spheroid model and NRG mice subcutaneously implanted with MIA PaCa-2 cells, respectively. Spheroids were treated with GNPs (7.5 μg/mL), DTX (100 nM), and 2 Gy of RT using a 6 MV linear accelerator. In parallel, mice received treatments of GNPs (2 mg/kg), DTX (6 mg/kg), and 5 Gy of RT (6 MV linear accelerator). In vitro results showed that though RT and DTX reduced spheroid size and increased DNA DSBs, the triple combination of DTX/RT/GNPs led to a significant 48% (p = 0.05) decrease in spheroid size and a 45% (p = 0.05) increase in DNA DSBs. In vivo results showed a 20% (p = 0.05) reduction in tumor growth 20 days post-treatment with (GNPs/RT/DTX) and an increase in mice median survival. The triple combination exhibited a synergistic effect, enhancing anticancer efficacy beyond individual treatments, and thus could be employed to improve radiotherapy and potentially reduce adverse effects.This work was supported by the Kuwait Foundation for the Advancement of Sciences (KFAS) under project code CB21-63SP-01; the NanoMedicines Innovation Network Strategic Initiative fund (NMIN-SI), a member of the Networks of Centers of Excellence Canada program; the John R. Evans Leaders Fund (JELF) from the Canada Foundation for Innovation (CFI); the British Columbia Knowledge Development Fund (BCKDF); the Discovery Grant from the Natural Sciences and Engineering Research Council of Canada (NSERC); the National Institutes of Health (NIH) of the United States of America under grants code R01CA257241, R01DE028105, R21CA252156, and R01CA274415; and a collaborative health grant from the University of Victoria.FacultyReviewe
Traditional ecological knowledge in Indigenous language revitalization
Full text linkTraditional Ecological Knowledge (TEK) is the knowledge and understanding of the complex systems of local ecology. Indigenous Language Revitalization (ILR) is a movement against the shifting use of a language within its particular community. Both languages and TEK are passed by intergenerational instruction and carried by each specific culture. This thesis explores how ILR and TEK are interconnected in many ways, including in language lessons (both method and content), in understanding worldviews which provide conceptual foundations in language, in language reclamation, and in understanding the land. This thesis follows an Indigenist paradigm and uses the structure of Parker (2012) to answer the following questions: how do communities include TEK in their language revitalization work? What are some of the effects of including TEK in Indigenous language revitalization work? What about TEK is important to language revitalization? To answer these questions, the thesis includes a review of the literature, interviews with Indigenous experts, a website survey and finally, a usable resource. The literature review contains analysis of extant literature. Interviews with experts who have been involved in the work of incorporating TEK in ILR in four Indigenous languages brings additional insight through their greater depth of knowledge, experience and perspective. The website survey contains an analysis of community ILR websites which correspond to the languages spoken by the interviewees. Finally, the creation of a resource ensures that this research is reciprocal. This study contributes to our knowledge of how TEK and ILR are intertwined, and underscores the importance of incorporating, respecting, and recognizing TEK in ILR.Graduat
UAV data upscaling for soil erosion monitoring in high-latitude rangelands, northeastern Iceland
No full textSoil erosion, while a typical geomorphic process, can be amplified and accelerated by land use and climate change. In Iceland, changes in vegetation cover since settlement in the 9th century have led to increased soil erosion. Current field-based methods for erosion mapping and monitoring are difficult and costly to employ frequently over large regions. The systematic and synoptic nature of satellite remote sensing is well-suited for wide-scale environmental monitoring. However, fine-scaled erosion may be obscured in coarse and moderate-resolution data (30-10 m). Here the synergistic use of RGB uncrewed aerial vehicle (UAV) and multispectral Sentinel-2 data is examined to bridge the gap between ground-based and spaceborne monitoring in northeastern Iceland. High resolution ( 90%). These data are upscaled to build a RF regression model estimating bare soil cover, yielding good results (R2 = 0.814). Using governmental land monitoring data, erosion severity classes are defined and a map for a portion of northeastern Iceland is produced. This study highlights the potential of multiscale remote sensing for estimating sub-pixel landscape information relevant to environmental monitoring.Jamie Cassels Undergraduate Research Awards (JCURA)UndergraduateReviewe
A time-domain doppler estimation and waveform recovery approach with iterative and ensemble techniques for bi-phase code in radar systems
No full textThis paper presents a novel, cost-effective technique for estimating the Doppler effect in the time domain using a single pulse and subsequently leveraging the precise Doppler value to recover the radar waveform. The proposed system offers several key advantages over existing techniques, including the ability to calculate the target speed without any frequency ambiguity and the ability to detect a wide range of target speeds. These two features are not available in any existing techniques, including the conventional moving target detection (MTD) processor. To ensure improved accuracy and robust estimation, the system employs ensemble and iterative techniques by recursively and efficiently reducing the Doppler residues from the signal. Furthermore, the proposed system demonstrates effective signal recovery of a well-known bi-phase code shape at low signal-to-noise ratios in just a few iterations. The performance evaluation of the new algorithm demonstrates its practicability and its superiority over traditional radar systems. Implementation on software-defined radio (SDR) reveals that the proposed system excels in Doppler estimation and signal recovery at low SNRs, demonstrating promising results.FacultyReviewe
Next generation seismic source detection by computer vision: Untangling the complexity of the 2016 Kaikōura earthquake sequence
Full text linkSeismic source locations are fundamental to many fields of Earth and planetary sciences, such as seismology, volcanology and tectonics. However, seismic source detection and location are challenging when events cluster closely in space and time with signals tangling together at observing stations, such as they often do in major aftershock sequences. Though emerging algorithms and artificial intelligence (AI) models have made processing high volumes of seismic data easier, their performance is still limited, especially for complex aftershock sequences. In this study, we propose a novel approach that utilizes three-dimensional image segmentation—a computer vision technique—to detect and locate seismic sources, and develop this into a complete workflow, Source Untangler Guided by Artificial intelligence image Recognition (SUGAR). In our synthetic and real data tests, SUGAR can handle complex, energetic earthquake sequences in near real time better than skillful analysts and other AI and non-AI based algorithms. We apply SUGAR to the 2016 Kaikōura, New Zealand sequence and obtain five times more events than the analyst-based GeoNet catalog. The improved aftershock distribution illuminates a continuous fault system with extensive fracture zones beneath the segmented, discontinuous surface ruptures. Our method has broader applicability to non-earthquake sources and other time series image data sets.This research is funded by: University of Victoria Graduate Award (FT); Mitacs Research Training Award (FT); The Charles S. Humphrey Graduate Student Award (FT); Alexander and Helen Stafford MacCarthy Muir Graduate Scholarship (FT); Melva J. Hanson Graduate Scholarship (FT); M.A. and D.E. Breckenridge Graduate Awards (FT); David McGillivray Scholarship in Science (FT); Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant RGPIN-2019-04148 (HK); Natural Resources Canada (NRCan) Environmental Geoscience Program (HK); NRCan Public Safety Geoscience Program (HK); NSERC Discovery Grant RGPIN-2018-03788 (KMY); Canada Research Chair Program (EN); NSERC Discovery Grant RGPIN-2017-04029 (EN).FacultyReviewe
Kindiziyin: Knowing our minds and our bodies – an Anishinaabe youth-led project on sexual wellness and healthy relationships
Full text linkIndigenous youth have demonstrated leadership in promoting sexual health in their communities and have asserted the right to sexual wellness, self-determination, and leadership. Yet, achieving this is limited by a lack of youth-focused sexual health programming and insufficient mentorship from their communities. This project engaged 16 Anishinaabe youth aged 15-25 years old, two Elders, and two community service providers in youth-led research in the context of sexual health within their home community of Wiikwemkoong Unceded Territory, an Anishinaabe community situated on Mnidoo Mnising (Manitoulin Island), Ontario. Using a Youth Participatory Action Research (YPAR) approach, participants attended two youth-led sharing circles and two participatory data analysis meetings and co-created a report to present back to community. The report will be shared with community stakeholders through youth-designed community sharing methods. This project identified needs for support in building healthy relationships for Anishinaabe youth and how it impacts their overall sexual wellness. Findings suggest that youth can be engaged as decision-makers in their own sexual wellness and their participation in research may lead to positive health outcomes. Findings will be used by the Wiikwemkoong youth and community to help create wholistic youth-led, strengths-based, and Indigenous-focused sexual health resources and/or programming.Graduat
Snow avalanches are a primary climate-linked driver of mountain ungulate populations
Full text linkSnow is a major, climate-sensitive feature of the Earth’s surface and catalyst of fundamentally important ecosystem processes. Understanding how snow influences sentinel species in rapidly changing mountain ecosystems is particularly critical. Whereas effects of snow on food availability, energy expenditure, and predation are well documented, we report how avalanches exert major impacts on an ecologically significant mountain ungulate - the coastal Alaskan mountain goat (Oreamnos americanus). Using long-term GPS data and field observations across four populations (421 individuals over 17 years), we show that avalanches caused 23−65% of all mortality, depending on area. Deaths varied seasonally and were directly linked to spatial movement patterns and avalanche terrain use. Population-level avalanche mortality, 61% of which comprised reproductively important prime-aged individuals, averaged 8% annually and exceeded 22% when avalanche conditions were severe. Our findings reveal a widespread but previously undescribed pathway by which snow can elicit major population-level impacts and shape demographic characteristics of slow-growing populations of mountain-adapted animals.Funding for this work was provided by the Alaska Climate Adaptation Science Center, Alaska Department of Fish and Game, Federal Aid in Wildlife Restoration Program grant AKW-10 Project 12.01, Alaska Department of Transportation and Public Facilities, Alaska Division of Geological and Geophysical Surveys, Bureau of Land Management, City of Sitka, Coeur Alaska, Federal Highway Administration, and Wild Sheep Foundation.FacultyReviewe
Entropy bounds for glass networks
Full text linkElectronic circuitry based on chaotic Glass networks, a type of piecewise smooth dynamical system, has recently been proposed as a potential design for true random number generators. Glass networks are good designs due to their potential for chaotic behaviour and because their analytic tractability allows us here to propose a method for approximating their entropy, a measure of irregularity in dynamical systems. We discuss some of the historical developments that led to the interest in the model that we consider within the context of random number generation. Additionally, we discuss a method for converting a Glass network’s governing piecewise-smooth differential equations into discrete-time dynamical systems, and then into symbolic dynamical systems. We also detail how the symbolic entropy of the given Glass network is bounded above by the entropy of the symbolic dynamical system formed from its transition graph, a type of directed graph that represents the possible transitions in phase space between regions not containing discontinuities. We then extend previous results by detailing our new method of refining the transition graph to be a more accurate depiction of the true system’s dynamics, making use of more specific information about trapping regions in phase space. Refinements come in the form of splitting nodes and duplicating/partitioning edges on the transition graph and removing those that are never realized by the continuous dynamics. We show that refinements can be done to arbitrary levels and in the limit as the level of refinement goes to infinity, the entropy of the refined transition graphs converges to the true entropy of the system. Along with this, since it is not possible to calculate the limiting value, approximation is necessary. Doing this by hand is tedious and difficult, so as a result, we also detail here an algorithm we devised that automates the refinement process, allowing for approximation (from above) of symbolic entropy. Various examples are considered throughout and we also discuss how numerical simulation can be used to non-rigorously estimate symbolic entropy, as an independent (approximate) verification of our results. Finally, we detail some unfinished and future work which could extend our results further, along with alternative methods to achieve similar and potentially even stronger results. With our results and algorithm, using upper bounds on a Glass network’s symbolic representation’s entropy is now a viable method for assessing the irregularity of its dynamics.Graduat
Exploring text-based support for designing weave drafts
No full textWe present the design and evaluation of Textere — a tool that helps weavers use text inputs to design weave drafts for weaving. Our research lies at the intersection of two areas of research: (i) text-based design tools, and (ii) design tools in weaving.
Text-based design tools have been explored by researchers in various domains like garment design, 3D modeling, and data visualization, showing benefits for expanding creative possibilities, enabling rapid prototyping, and making design processes more accessible for a broader range of users. Motivated by such benefits, in our research we explore how text-based tools can help with designing weave drafts. Weaving is a design and production activity, wherein weavers map ideas, inspiration, or client requirements to visual elements like pattern, color, and weave structures to design a weave draft. The drafts are then physically produced using a loom. Weave drafts are designed before production, to convey what the appearance of the final product will look like. Design tools in weaving use different modalities, like audio and tactile, to make the design process more accessible, creative, and efficient— benefits that design tools in other domains have achieved using text support. Several text-based scenarios in weaving, require interpretation of words from text inputs. Yet, current text-based techniques and design tools in weaving are limited to mapping individual alphabets to specific weaving elements, or incorporating text as is in the weave draft. We extend this research space by exploring how weave drafts can be designed using meaning or interpretations of words.
We developed Textere, a text-based tool for designing weave drafts using the open source AdaCAD weaving platform. Using Textere, weavers can map text inputs to visual elements such as color, weave structure, and patterns based on meanings and interpretations. We curated the text-to-visual mappings used in our system from existing user studies in research, that describe how people associate words to visual elements. To evaluate Textere, we first used the evaluation-by-demonstration method, to produce four physical woven samples designed using our tool. Further, we conducted a qualitative study with 12 weavers to evaluate opportunities and limitations of using Textere, by comparing workflows to the tool we extended, AdaCAD, with no explicit text-to-visual support.
From our study we learned about the strengths and limitations of Textere. Informed by our results, we further discuss how text-based design tools like Textere can enable reflective decision making, generation and broadening of ideas, gaining different perspectives on what visual elements represent, and contribute to an ecosystem of tools for designing weave drafts. This thesis makes three contributions: i) a novel tool for designing weave drafts using text inputs, ii) empirical findings on the benefits and limitations of text-based interactions for designing weave drafts, and iii) a set of design implications for future text-based design technologies.Graduat