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State of Salmonid Streams Around the World: A Multi-Scale Investigation of Habitat Quality, Restoration, and Abundance
Get PDFMany salmonid species are listed as threatened or endangered, despite over a hundred years of conservation efforts. Additionally, little is known about the spatial extent and abundance of salmonid populations around the world. This research combines ecological and hydrogeomorphological approaches to investigate salmonid abundance in streams. It uses a meta-analysis, field observations and a systematic review to assess restoration options for salmonid populations, determine if a morphological index is aligned with physical habitat and fish-based indices, and explore the range of salmonid abundance in streams around the world. Data from 100 stream restoration projects show that in-stream structures, a common restoration technique for salmonids, increase salmonid abundance. However, most projects are implemented at small spatial scales of a few hundred metres, and monitored for less than 5 years, which may be insufficient time for population changes to be apparent. Hence, it is unclear whether these projects provide a long-term solution. The Morphological Quality Index (MQI) considers fluvial processes at larger scales as well as channel forms, human impacts, and historical changes, but few studies have assessed its relevance for ecosystem health. A significant correlation was found between the MQI and habitat quality (using the Qualitative Habitat Evaluation Index, QHEI), in 26 salmonid streams, but establishing a strong correlation with fish metrics remains challenging. To describe the metrics of salmonid abundance at a broader spatial scale, a database was created using published material of over 1000 rivers with estimated salmonid biomass, covering 27 countries. This allowed detailed analyses of differences in biomass by species, region, period, and sampling techniques. Mean global biomass is 5.2 g/m2, and while most streams are under 10 g/m2, there is a large range (0-70.3 g/m2). Salmonid production recorded for 194 rivers averaged 6.3 g/m2/yr, and biomass and production were highly correlated (R = 0.82) with a mean production to biomass (P/B) ratio of 1.08. Expanding the list of variables in the database can help develop models to predict salmonid biomass, and determine conditions in high biomass streams. This knowledge will be useful for conservation and management authorities to design successful conservation programmes at a watershed scale
Exploring TikTok’s Potential as a Platform for Valuable Journalism
Get PDFNews organizations have begun incorporating the social media app TikTok as one of the many platforms they post their content to. In Canada, since the passing of the Online News Act (Bill C-18) in summer 2023, Meta, the company that owns Facebook and Instagram, has blocked Canadian news outlets from posting content on their platforms, leading many to turn to TikTok to reach audiences on social media. The app's popularity and lack of transparency raise questions about whether valuable journalism could be possible on the app. This research-creation thesis uses Irene Costera Meijer's (2022) "valuable journalism" concept, which describes three experiences that may lead individuals to feel a sense of value towards a news story: (1) getting recognition, (2) increasing mutual understanding, and (3) learning something new. Guided by these concepts, this research analyzes three Canadian commercial mainstream news outlets’ TikTok accounts—namely CTV News, Global News, and CityNews Toronto—to explore whether their content exhibits elements of these "valuable journalism" experience. The total number of TikTok videos analyzed in this research is 542 across all three news outlets' TikTok accounts between August 11 and November 11, 2023. The results show a progressive use of TikTok and overall evidence of valuable experiences according to Costera Meijer's concepts, but also suggests more can be done to creatively produce news on the app using its tailored tools, and to reach audiences in valuable ways. These findings helped inform the creation of three original TikTok videos that each seek to demonstrate the elements of Costera Meijer's three valuable news experiences, to bridge these theoretical aspects to practical elements of journalism production for social media
Consequence-based Algebraic Reasoning for SHOQ
Get PDFQualified Cardinality Restrictions (QCRs) and nominals are the two constructors in OWL 2 DL to apply numerical restrictions on domain concepts and relations. Utilizing these constructors in designing real-world ontologies is unavoidable in many domains, particularly in modelling structures with complex objects. Most existing DL reasoners employ arithmetically uninformed processes to reason about these numeric restrictions by exploring all possible cases.
Meanwhile, Consequence-Based (CB) reasoning algorithms have proven to have a phenomenal performance in practice. However, they have yet to be extended for the expressive DL SHOQ - a DL that supports named individuals and cardinality restrictions. This research presents a novel consequence-based algorithm to classify SHOQ while handling the arithmetic interaction between QCRs and Nominals using atomic decomposition and integer linear programming. The proposed calculus can classify the whole ontology in one round. We have implemented our calculus in a prototype reasoner called CARON.
Empirical evaluation of our implementation demonstrates that CARON outperforms existing reasoners in handling numerical restrictions. At the same time, it offers a competitive performance compared to other state-of-the-art systems. Our results also show that CARON nicely complements existing reasoners for handling numerical restrictions since it provides an arithmetically informed process for handling these constructors. Accordingly, the calculus and implementation presented in this thesis are critical to improving practical reasoning with expressive DLs, including numerical restrictions
A Comprehensive Look at Intergroup Relations and Contact Between International Students and the Host Community
Get PDFPrevious research has demonstrated that intergroup relations and contact between international students and host communities may be challenging. While international students sometimes experience discrimination on- or off-campus, international students themselves may also form negative attitudes toward host community members based on imagined or real experiences with them. Therefore, to address this issue, this dissertation set out to investigate variables that may lead to potentially prejudicial attitudes between international students and host community members and to examine the link between such attitudes and the quantity and quality of intergroup contact.
Study 1 explored potential factors that inform francophone residents’ attitudes toward international students in English-medium universities in Montréal and examined the link between their quality and quantity of contact and their attitudes and perceived threat. First, between-group comparisons revealed similarly positive attitudes toward and relatively low levels of perceived threat from international students, except for linguistic threat, which was significantly higher for non-student francophones. Non-student francophones also reported considerably less frequent and lower quality of contact with international students. Second, while symbolic threat was the common predictor of attitudes for both student and non-student francophones, intergroup anxiety also emerged as a significant predictor of student francophones’ attitudes toward international students. Third, contact quality yielded significant associations with both attitudes (positive) and all types of perceived threat (negative except for stereotypes), whereas contact quantity was linked with intergroup anxiety only for student francophones.
Study 2 essentially replicated Study 1 to provide the international student perspective regarding intergroup attitudes and contact. International students reported similarly low perceived threat from (except for linguistic threat) as well as comparably high quality of contact with student and non-student francophones. However, they indicated significantly more favourable attitudes and more frequent contact with non-student francophones. While intergroup anxiety was the predictor of attitudes toward student francophones, stereotypes predicted their attitudes toward non-student francophones. Contact quality yielded positive links with attitudes and negative associations with all perceived threats, except for stereotypes. Contact quantity, on the other hand, was associated with intergroup anxiety, linguistic threat, and stereotypes only for non-student francophones
Assessing the Impact of Autonomous Vehicles on Supply Chain Performance – A Case Study of Agri-Food Supply Chain
No full textIn an era marked by rapid technological advancements, the integration of Autonomous Vehicles (AVs) into supply chain networks represents a transformative shift, promising to redefine the paradigms of logistics and transportation. This thesis delves into a comprehensive assessment of the impact of AVs on supply chain performance, with a particular focus on network design, operational efficiency, and environmental sustainability. Employing the advanced simulation capabilities of anyLogistix (ALX), the study constructs a digital twin of a conventional supply chain network, encompassing suppliers, production facilities, distribution centers, and customer endpoints. The research methodically integrates AVs into this intricate network, aiming to unravel the multifaceted effects on transportation logistics including transit times, cost-efficiency, and sustainability.
Through simulations and scenarios analysis, the study scrutinizes the operational resilience and adaptability of supply chains in the face of dynamic market conditions and disruptive technologies like AVs. Furthermore, the thesis undertakes carbon footprint analysis, quantifying the environmental benefits and challenges associated with the adoption of AVs in supply chain operations. The insights from this research are anticipated to offer a strategic framework for industry stakeholders, guiding the adoption of AVs to foster a more efficient, responsive, and sustainable supply chain ecosystem. The findings aim to serve as a cornerstone for future research and practical implementations in the realm of intelligent transportation and supply chain management
Relationship Between Paraspinal Muscle Morphology, Function, and Physical Status in Common Spinal Disorders
Get PDFThe deep paraspinal muscles are essential for providing physical support and stability to the spinal column. They play a vital role in maintaining fine postural control of the spine and are responsible for controlling all movements of the vertebral column. These muscles work in coordination to ensure proper alignment and movement of the spine, thereby contributing to overall spinal health and function. Dysfunction or weakness in paraspinal muscles can lead to instability, poor posture, and increased risk of spinal pain disorders. Therefore, understanding the role of deep paraspinal muscles is crucial in maintaining spinal health and preventing musculoskeletal disorders. This summary highlights the significance of assessing both morphology and function of paraspinal muscles in common spinal disorders including chronic low back pain (LBP) and degenerative cervical myelopathy (DCM). While previous studies have focused on either morphology or functional deficits separately, this dissertation aims to comprehensively investigate the structure-function relationship using advanced imaging techniques like magnetic resonance imaging (MRI) and ultrasound. Specifically, chapter three focuses on understanding the relationship between lumbar multifidus muscle (MF) muscle morphology and function in chronic LBP patients, utilizing measures such as fatty infiltration, contraction, stiffness, and elasticity. Similarly, chapter four and five aim to assess cervical muscle morphology as predictors of prognosis and functional recovery in patients with DCM, both pre- and post-operatively. Such comprehensive evaluations are crucial for improving diagnosis, intervention, and therapeutic strategies in spinal disorders, ultimately enhancing patients’ clinical outcomes and quality of life. Finally, chapter six discusses the findings from chapters three, four and five and offers a general conclusion and recommendations for future research
Synthesis of Tb-UiO-66 and Eu-UiO-66 Analogues with Enhanced Photoluminescence
No full textOver the past few decades, metal–organic frameworks (MOFs) have gathered considerable attention due to their potential for high surface area, crystallinity, and tunable chemical composition. These porous materials are made of metal nodes bridged by organic linkers. Due to the versatility of MOFs, they can be used for different applications ranging from wastewater remediation to biomedical imaging, amongst others.
Rare-earth (RE) elements have unique luminescent properties, including narrow emission peaks, large Stokes’ shifts, and long luminescent lifetimes. RE-MOFs have similar properties as MOFs made from the d-block metals such as high surface areas and the capability of forming tunable pores in addition to having metal-based photoluminescence.
This work explores a new series of Tb-based and Eu-based MOFs that were synthesised to study the effect of linker-to-metal energy transfer on the quantum yield of Tb(III) and Eu(III) emission from the MOFs. The MOFs presented in this work are analogues of Tb-UiO-66 and Eu-UiO-66 (UiO: University of Oslo). The synthesis, characterization, and photoluminescent properties of Tb-UiO-66 and Eu-UiO-66 analogues are presented in Chapter 2 and 3, respectively. The structure and properties of the materials presented are studied using powder X-ray diffraction, nitrogen adsorption-desorption isotherms, thermogravimetric analysis, inductively coupled plasma mass spectrometry, scanning electron microscopy, proton nuclear magnetic resonance spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, diffuse reflectance UV-Vis spectroscopy and photoluminescence spectroscopy including quantum yield
Free-Energy Based Modeling of Planar Dielectric Elastomer Actuators
Get PDFDielectric elastomer actuators (DEAs) have gained increasing attention over the last decades and have been widely developed for applications fields such as robots, aerospace, biomedicine due to the fast response, high energy density, light weight, and low cost. However, the task of modeling of DEAs is typically challenged in the presence of the nonlinear features, time-independent viscoelastic behaviors, complex electromechanical coupling, etc.
To address such a challenge, a free-energy based model for DEAs moving in vertical direction is proposed, in an effort to investigate the physical properties of DEAs in this research. The developed model is based on the principle of nonequilibrium thermodynamics, where the Gent model and generalized Maxwell model are applied to describe the free energy and viscoelastic behavior of DEA, respectively. Unlike the existing modeling methods, this research narrows the focus on the inertial force and viscoelasticity which leads to DEA’s instability.
After that, the free-energy based model is simulated in MATLAB and the several sets of experiments are implemented by setting various driving voltage amplitudes and frequencies. According to the experimental data, the undetermined parameters of the model are identified by using differential evolutionary algorithm. The comparison of the model simulation and experimental results supports the validation of the proposed free-energy based model
Exact and Factor Two Algorithms for Broadcast Time
Get PDFBroadcasting is a fundamental information dissemination primitive in interconnection networks, where a message is passed from one node to all other nodes in the network. Following the increasing interest in interconnection networks, extensive research was dedicated to broadcasting. Two main research goals of this area are finding inexpensive network structures that maintain efficient broadcasting and finding the broadcast time of a given network topology. In the scope of this study, we will mainly focus on determining the broadcast time of a given network. The broadcast time problem on an arbitrary network is known to be NP-hard. We consider this problem on different network topologies and settings.
We begin by studying the broadcast time problem on split graphs. First, we introduce a tight polynomial-time constant approximation algorithm for broadcasting on split graphs. Then, we study some important characteristics of an optimal broadcast scheme on split graphs and design a strategy for generating optimal broadcast schemes. We apply our findings to devise an efficient broadcasting heuristic on split graphs and on natural generalization of split graphs, called (k,l)-graphs.
Next, we study broadcasting on graphs that comprise some recursive structures. We introduce an exact polynomial-time algorithm on closed chains of rings. A closed chain of rings is a sequence of cycles, where every two consecutive cycles, and the first and the last cycles, share a common vertex. Additionally, we initiate a novel direction to designing broadcasting algorithms on recursively defined graphs. We provide a theoretical foundation for future broadcasting research, as well as discuss several practical applications of the approach we introduce.
Last, we study the problem on k-path graphs, one of the simpler graph families with intersecting cycles. To better understand the challenges of broadcasting on arbitrary graphs, families with intersecting cycles are crucial to study. We improve the current best approximation ratio for broadcasting on k-path graphs by a multiplicative factor of two. Further, we propose a new optimization problem called 3-List-Sub, helping us to design an optimal broadcasting algorithm on restricted k-path graphs which was unsolved to date
Integrating Electrochemical Sensing with Droplet Microfluidics for Metabolic Engineering
No full textMeasuring metabolites produced by large libraries of metabolically engineered yeast requires high throughput screening technology. Current screening methods use mass spectrometry to measure metabolites. Higher throughput detection methods are available, however they rely on fluorescent detection. Measuring non-fluorescent metabolites requires an alternative detection method integrated in the screening system. Herein, we introduce an electrochemical sensor, that can be integrated with droplet microfluidics to detect a key branch point molecule in opiate biosynthesis: (S)-reticuline, which is produced by metabolically engineered yeast. This platform technology could be used to screen a heterogenous library consisting of engineered yeast that secrete (S)-reticuline. Demonstrating that yeast cells in a population, which produce high titers of (S)-reticuline can be detected using this screening system will open the door to screening libraries of micro-organisms that produce other electroactive, non-fluorescent secreted metabolites