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Effect of Localized Muscle Fatigue on Postural Control Stability and Muscle Activation Strategies
No full textOptimal postural control involves the integration of sensory inputs from the visual, vestibular, and proprioceptive systems. It requires both individual muscle activation and intermuscular interactions that adapt balance strategies to task demands, while being shaped by sensory feedback. Neuromuscular fatigue (NMF) is thought to destabilize postural control by degrading proprioceptive reliability and altering muscle activation strategies. Yet, whether fatigue effects generalize across postural contexts remains uncertain. This thesis aimed to examine how NMF influences postural control stability and muscle activation strategies during two tasks of varying stability demands: quiet standing and forward lean. Specifically, we sought to determine how fatigue influences: 1) lower-limb muscle activation, co-contraction patterns and intermuscular coherence, 2) center of pressure (COP) behavior across different time scales, and 3) the relationship between EMG coherence and open- and closed-loop postural control mechanisms inferred from COP Discrete Wavelet Transform analysis. Fourteen healthy adults performed quiet standing and forward-lean tasks with eyes open or closed, before and after a standardized isometric plantarflexion/dorsiflexion fatigue protocol. We quantified neuromuscular activity and coordination (EMG amplitude, co-contraction, intermuscular coherence) as well as postural sway (center-of-pressure (COP) metrics and timescale-specific control (wavelet-based energy). The effects of fatigue and postural task were evaluated using repeated-measures ANOVA models. Pearson's correlations were also used to assess the relationship between changes in EMG and COP variables. Results showed that muscle activation patterns were primarily driven by postural task demands rather than fatigue. Intermuscular coherence analysis revealed task- and frequency-dependent fatigue effects, with agonist-agonist coherence increasing significantly in mid- and high-frequency bands during the most challenging condition (forward lean, eyes-closed) after fatigue (p < 0.01). Traditional center of pressure measures showed limited fatigue effects, and discrete wavelet analysis revealed no significant fatigue-induced changes in frequency band energy distributions. These findings demonstrate that NMF produces subtle, task-dependent alterations in postural control that are most evident during challenging postural demands
A Discourse Analysis of Crisis Communication from the Canadian Federal Department: Environment and Climate Change Canada
No full textThis thesis examines how Environment and Climate Change Canada (ECCC) constructs risk, authority, and institutional identity in crisis communications from 2011 to 2021. Using James Paul Gee's (2011) discourse tools, I analyze federal messaging to understand how ECCC frames environmental risk, asserts credibility, and guides public response. These aspects are studied through qualitative analysis of a significant corpus. Findings show that ECCC's messaging evolves to become more urgent and crisis-focused, particularly in response to climate change. Shifts in identity highlight a strategic adaptation to societal and environmental contexts. This research contributes to knowledge by illustrating how federal institutions use language to mediate public understanding, build legitimacy, and respond to mounting pressures around environmental risks and crises
Comprehensive Condition Assessment of ASR Affected Pier Cap and Pier Shaft from Montreal's Champlain Bridge
No full textAlkali-Silica Reaction (ASR) is amongst the most harmful damage mechanisms affecting concrete infrastructure in Canada and worldwide. Among ASR affected structures in Canada the Champlain Bridge (CB), a six-lane highway bridge which crossed the St. Lawrence River and St. Lawrence Seaway in the province of Quebec, is a prime example with deterioration leading to closure of the bridge in 2019 after only 57 years in service. During decommissioning of the CB, a number of sections from its structural members (i.e., pier shaft – PS, pier cap – PC) were stored for further coring and analysis. This work presents a comprehensive investigation of an ASR affected PC and PS from the CB including a thorough external appraisal (i.e., comprehensive visual inspection and non-destructive testing) accompanied by laboratory investigation of extracted concrete cores using a multi-level assessment protocol (i.e., microscopic and mechanical test procedures). Microscopic investigations were conducted primarily using the damage rating index and supplemental image analysis while mechanical assessment was conducted through resonant frequency, the stiffness-damage test and compressive testing. This assessment identified ASR as the primary damage mechanism with cores exhibiting high to very high levels of deterioration in both members. Image analysis identified distinct crack orientations in extracted cores corresponding to expected expansion occurring preferentially to the least restrained directions of both the PC and PS members. Finally, a strong correlation between microscopic damage features and mechanical performance of the affected core specimens was observed; induced deterioration was found to be strongly associated to direction, depth and environment of the specimens
Applications of social marketing for implementation science: a scoping review
No full textAbstract Background Implementation science has a history of drawing from other fields to advance its science, yet understanding how approaches from marketing might enhance the field remains a largely untapped area of theoretical and methodological potential. Social marketing (i.e., applying commercial marketing to solve social or health problems) is a branch of marketing that shares many conceptual features with implementation science (e.g., behaviour change), but remains an unrealized opportunity for synergy. This review aimed to 1) describe studies that have tested social marketing interventions in controlled designs; 2) describe these interventions including their context, mechanism, and outcome; and 3) propose social marketing approaches that might be usefully applied to implementation science. Methods This scoping review, with a team consensus discussion, followed JBI (formerly the Joanna Briggs Institute) methodological guidance and included a team of researchers and practitioners in implementation, marketing, and social marketing. Twelve databases were searched. Studies were included that 1) utilized a randomized or non-randomized controlled intervention design; and 2) tested a social marketing intervention as defined by five essential social marketing criteria. Two reviewers independently completed all screening and extraction. Variables extracted included intervention details per social marketing criteria and the intervention’s context, mechanism, and outcome. Team consensus discussions of the scoping review results were used to determine approaches that might be usefully applied more broadly across implementation science. Results Screening of 4,867 citations yielded 28 included studies published from 1999–2023. All topics were from the health field and included nutrition (13, 46%), sexual health/family planning (6, 21%), physical activity (3, 11%), child safety (1, 4%), cancer screening (1, 4%), fall prevention (1, 4%), worksite safety (1, 4%), sanitation (1, 4%), and substance abuse (1, 4%). Novel theories identified included ‘Exchange Theory’ and ‘Consumer Information Processing Model’. Proposed approaches to consider for application included: leverage emotions; design for appeal; consider what your audience values; understand the price; understand the place; emphasize competitive advantage; and use branding. Conclusions This review examined the application of social marketing theories and approaches to implementation science. Applying social marketing approaches could invigorate novel and creative thinking in implementation science. Registration Open Science Framework Registration link: osf.io/6q834
Impact of Alginate on the Physicochemical Properties and Reactivity of Iron Oxides
No full textIron (Fe) minerals often associate with natural organic matter (OM), ranging from complex compounds like humic acids to simple ligands such as citrate and oxalate, in soils and aquatic systems. These Fe-OM interactions occur through microbial mediation, OM sorption to Fe minerals, or mineral formation in the presence of OM (coprecipitation). Such associations influence the sorption capacity of Fe minerals for foreign species (e.g., phosphate, arsenate, trace metals), their thermodynamic stability, and overall physicochemical and mineralogical characteristics. This study aimed to (1) examine how OM affects the properties and bioavailability of common Fe (oxyhydr)oxides-ferrihydrite (Fh), lepidocrocite (Lp), and goethite (Gt). These minerals were synthesized in the presence of Na-alginate (as a model OM) at C/Fe ratios of 0, 0.5, 1.0, and 1.5 mol:mol. OM notably altered mineral surface area, porosity, and crystallinity. Surprisingly, microbial Fe(III) reduction kinetics were comparable between coprecipitates and pure minerals. However, the extent of reduction varied by mineral: 2-line Fh coprecipitates showed ~15% lower reduction, whereas Lp and Gt coprecipitates exhibited only 5-7% higher reduction relative to pure minerals. These findings suggest that OM effects on Fe bioavailability are mineral-specific and more complex than previously thought, emphasizing the need to consider both mineral type and OM interactions in Fe cycling studies.
To further explore the impact of additional environmental variables, the study (2) investigated how phosphate (P) sorption mode, adsorption versus coprecipitation (P/Fe 0, 0.01, and 0.1 mol:mol), influences the properties and reactivity of alginate-Fh composites (C/Fe 0 and 1.0). P-OM-Fe coprecipitates showed the highest microbial and chemical reducibility. High P loading, irrespective of sorption mode, nearly completely stabilized Fh against transformation to more crystalline phases - more effectively than alginate alone. Notably, coprecipitated P and OM together conferred added resistance to mineral transformation following biotic reduction. These findings underscore the importance of considering both OM and P, and how P is incorporated, when evaluating the environmental stability and reactivity of Fe minerals, with implications for soil fertility, contaminant mobility, and nutrient cycling.
Finally, the study (3) evaluated the effect of γ-irradiation (25 kGy) as a sterilization method on OM-Fe coprecipitates. Post-irradiation, Fe(III) dissolution and reduction increased with OM content, and particle size varied based on the mineral coprecipitate type, while specific surface area and porosity were altered. Mössbauer spectroscopy revealed increased Fh crystallinity after irradiation, although bulk mineralogy remained unchanged. Interestingly, microbial reduction rates post-irradiation remained similar to untreated samples, yet the extent of Fe(III) reduction, particularly for Fh coprecipitates, increased by up to 28%. Slight increases in bioreduction were also seen for select Lp and Gt coprecipitates. These results highlight that γ-irradiation can modify key physical and chemical characteristics of Fe-OM composites, potentially skewing measurements of bioavailability and contaminant binding in sterilized samples.
Taken together, these findings deepen our understanding of how OM, phosphate, and experimental treatments affect the environmental reactivity and transformation of Fe (oxyhydr)oxides. This knowledge is essential for improving models of carbon cycling under reducing conditions, and for developing strategies to manage nutrient and metal mobility in soils and sediments
Ethnonationalisme et violence: des insurrections Banyamulenge aux revendications Kongo. Dilemme de sécurité intersociétal en République démocratique du Congo
No full textLa présente thèse a pour objectif de comprendre la propension des groupes ethniques à adopter des attitudes ethnonationalistes lorsqu'ils se trouvent en situation d'insécurité. Elle propose une analyse axée sur les sources du conflit et suggère de considérer les doléances des organisations concernées comme un point de départ essentiel pour un examen approfondi des conflits à caractère ethnique. Une étude comparative asymétrique des cas des Banyamulenge et des Bakongo en République démocratique du Congo fournit des éléments pertinents pour appréhender la manifestation de ce phénomène.
Pour éclairer les questions fréquentes concernant la tendance des groupes tels que Banyamulenge à s’engager dans la guerre et la violence, nous avons élaboré un cadre théorique centré sur le dilemme de sécurité intersociétal. Ce contexte d’incertitude et de méfiance se manifeste lorsque le pouvoir public, affaibli, fragilisé et dépourvu de ressources, devient incapable d’assurer la sécurité de tous. Un tel environnement incite inévitablement les groupes ethniques, préoccupés par leur survie, à se replier sur leur identité et à prendre des mesures pour se protéger. Dans cette thèse, nous proposons que le cycle d’insurrections des Banyamulenge dans l’est de la RDC peut être compris comme le produit de ce dilemme, bien que la recherche de gains économiques demeure la motivation centrale de certains membres de l’élite banyamulenge. Nous nous concentrons particulièrement sur la milice d’autodéfense Twirwaneho dans les hauts plateaux du Sud-Kivu, dont la composition homogène et le récit génocidaire illustrent bien cette volonté de mobilisation pour une auto-assistance.
La situation des Banyamulenge est ensuite comparée à celle des Bakongo dans l’ouest du pays, dont les aspirations nationales sont plus marquées, notamment à travers le mouvement ethnoculturel Bundu Dia Kongo. Cependant, chez les Banyamulenge, il existe une influence accrue d'une ethnie tutsie parente située à l'étranger, dans la lutte pour l'autodéfense, voire l'autodétermination. Cela n’empêche pas Bundu Dia Kongo d'utiliser sa propre « coethnicité » étrangère, disséminée à travers l'ancien territoire du Royaume Kongo, comme argument pour raviver la nation kongo et envisager un avenir où les Bakongo y vivraient. Dans les deux cas, la violence est présente, bien qu'à des niveaux d'intensité différents, qu’elle émane des communautés ethniques rivales ou de l'État congolais lui-même.
Cette thèse vise à apporter une contribution significative à l’étude des phénomènes ethnonationaux, en mettant en lumière l’expérience locale des communautés observées. Ce choix justifie l’adoption d’une approche phénoménologique, pertinente pour saisir les perceptions des groupes. La combinaison de cette approche avec une méthode déductive structurée autour de la théorie du dilemme de sécurité intersociétal offre une opportunité substantielle pour suivre le parcours des groupes ethniques en conflit, depuis l’expression des doléances jusqu’à l’affirmation ethno nationale ou à des attitudes considérées comme telles
Prediction of the Swelling Properties of Expansive Soils Using Machine Learning Methods
No full textExpansive soils swell significantly when they absorb water and exhibit high swelling pressures if their volume changes are restrained. This characteristic behavior of all expansive soils is mainly attributed to the presence of hydrophilic clay minerals such as montmorillonite and illite. Geotechnical engineers worldwide face considerable challenges in providing reliable approaches for construction and design of geo-infrastructures constructed with or within expansive soils. Common engineering problems caused by these soils include cracked and uneven pavements, uplifted and tilted foundations, slope failures, and the sliding of retaining walls. Over the past several decades, annual global economic losses associated with the damage and repair costs of geotechnical infrastructures built within or with expansive soils have been estimated at several billion US dollars.
To better understand and address these challenges, researchers have developed various experimental methods over the past five decades to determine key swelling properties of expansive soils that include: swelling and compression indices, swelling pressure, and swelling potential. These laboratory methods, particularly oedometer tests, are reliable and reproducible. However, they require extensive equipment and trained personnel, and the testing process often takes several weeks to complete, making them both time-consuming and expensive. As a result, they are not always practical for use in routine geotechnical investigations. Although several empirical and semi-empirical equations have been proposed to predict the swelling behavior of expansive soils, their applications are often limited due to regional differences in expansive soil characteristics and a lack of general applicability. Therefore, there is a need for more simple, economical, reproducible and reliable prediction methods that can be used universally for different types of expansive soils based on basic soil properties that can be obtained from conventional laboratory tests.
In this study, to achieve this key objective, simple models / equations are developed for key geotechnical properties related to the swelling and compressibility behavior of expansive soils with the aid of advanced Machine Learning (ML) techniques. Comprehensive databases were compiled from published literature, covering a wide range of soil types and geological conditions around the world. Three comprehensive ML algorithms—Multilayer Perceptron (MLP), Support Vector Machine (SVM), and Extreme Learning Machine (ELM)—were applied, along with regression analysis, to predict the swelling index and swelling pressure based on fundamental soil properties; namely, liquid limit, plasticity index, dry density, and initial suction. The proposed models demonstrated reliable predictive capabilities across diverse datasets.
Additionally, Multivariate Adaptive Regression Splines (MARS) and MLP algorithms were employed to develop prediction models for estimating the swelling potential of expansive soils. An extensive dataset was used to support model training and validation. Sensitivity analysis was applied to refine the input variables, ensuring an efficient and accurate model structure. Simplified equations were derived from the optimized models to facilitate their application in practice. The validation of these models was conducted through comprehensive comparative analyses, including evaluations between different ML models and against traditional empirical equations. The results demonstrated significant improvements in prediction accuracy and generalization, offering a practical approach for assessing swelling potential.
Furthermore, in this study ML-based models are presented for predicting the compression index of expansive soils, a critical parameter for evaluating compressibility and settlement behavior in foundation design. A database of 238 expansive soil samples gathered from different countries of the world was established, representing diverse geotechnical conditions. Sensitivity and correlation analyses identified liquid limit, plasticity index, initial void ratio, and dry density as the most influential input factors. Two primary ML algorithms, Newton-Raphson-Based Optimizer Enhanced Extreme Gradient Boosting (NRBO-XGBoost) and MLP, were used to develop reliable prediction models. While the NRBO-XGBoost model exhibited superior performance in terms of accuracy and generalization, the MLP model was further simplified into an empirical equation, making it more convenient for preliminary design applications.
To further evaluate the accuracy and reliability of the proposed models and equations, extensive validation studies were carried out. Published case studies results from the literature were used to assess the prediction accuracy of the models for four key expansive soil parameters: swelling index, swelling pressure, swelling potential, and compression index. The results of these analyses showed strong agreement between the predicted and measured values across different soil types and geographical regions. These case studies confirmed the applicability of the models for capturing the behavior of expansive soils under varying conditions.
In addition, this study integrates the proposed models to jointly simulate the volume change behavior of expansive soils under constant-volume and consolidation-swell conditions. By applying the swelling index, swelling pressure, swelling potential, and compression index models together, the overall volume change behavior was predicted and validated using laboratory data from multiple expansive soils. The results demonstrate the consistency and compatibility of the models when applied in combination, reinforcing their practical value in engineering practice applications.
In summary, this study presents a valuable framework that integrates conventional soil mechanics principles with advanced ML algorithms to improve the prediction of key volumetric parameters of expansive soils. The proposed models and simplified equations enable reliable estimation of swelling and compressibility characteristics based on basic soil properties. Their consistency and compatibility, demonstrated through extensive validations on extensive laboratory test results and case studies, highlight their practical value in conventional design and geotechnical engineering applications across various regions around the world affected by expansive soils
Principles of Management in Nutrition
No full textDrawing from foundational open educational resources in foodservice and business management, this resource was developed to meet the specific learning needs of dietetic and foodscience students. The book covers key principles of management, leadership, human resources, marketing, and strategic planning—framed within the context of dietetic and foodservice practice. Designed to support active learning, it includes review questions, practical exercises, and Canadian examples to help students link theory to real-world practice. The resource empowers students to think critically about their roles as future foodservice managers, small business owners, and leaders in food and nutrition.University of Ottawa Library OER Gran
2025 position statement on active outdoor play: process and methodology
No full textAbstract Background The 2015 Position Statement on Active Outdoor Play highlighted the benefits of active outdoor play for child health and development and had significant impact on public policy, law, philanthropy, and research in Canada and internationally. To celebrate its 10th anniversary, we led an update to the Position Statement that is global in scope and inclusive of all human age groups. The goal of this manuscript is to outline the process and methodology involved in developing the 2025 Position Statement on Active Outdoor Play. Methods The process involved several key steps: (1) establishing an international leadership group; (2) forming an international steering committee; (3) conducting an environmental scan of historical key events in active outdoor play; (4) using text-mining and linked network analyses to identify core research themes and map relationships among outdoor play organizations; (5) developing a conceptual framework through a consensus-building process; and, (6) using this conceptual framework to guide the completion of a series of reviews used to inform the 2025 Position Statement. Results The environmental scan identified 136 key events that provided historical context for the evolution of active outdoor play. Text-mining and linked network analyses revealed 10 core research themes and mapped relationships among key organizations and individuals in the field. Informed by these themes and concepts, a draft conceptual framework was developed and circulated to the > 130-person steering committee for review and consensus. The final version of the conceptual framework encompassed 9 key themes, which guided the focus of 18 reviews used to inform the scope and content of the 2025 Position Statement on Active Outdoor Play. Conclusions A three-year-long process involving an international leadership group and >130 person steering committee led to the development of an environmental scan, text-mining and linked network analysis, and a conceptual framework including 9 key themes with bidirectional relationships with active outdoor play that guided the development of 18 reviews. Collectively, this work served to inform the updated Position Statement on Active Outdoor Play, which aims to encourage humans of all ages to play, learn, teach, grow, and thrive outdoors and serve as caring stewards of the land, water, air, plants, animals, and each other
High Standards, Higher Doubts: The Hidden Cost of Perfectionism on Impostor Feelings in Graduate Students
No full textOver 40 years ago, Clance and Imes (1978) introduced the concept of the impostor phenomenon to describe high-achieving individuals who, despite evident success, experience persistent self-doubt and fear of being exposed as intellectual frauds. This doctoral thesis expanded on that foundational work by examining how perfectionism and its signature cognitive and socio-behavioural expressions shape the experience of impostor feelings among graduate students. Across four studies organized into two distinct research axes, this doctoral research program used meta-analytic, cross-sectional, and short-longitudinal designs to clarify the dispositional and contextual mechanisms contributing to the experience of impostor feelings in academic settings.
Study 1 (k=20) provided a meta-analytic synthesis of the associations between perfectionism and impostor feelings. The findings confirmed that perfectionistic concerns are strongly associated with impostor feelings, while perfectionistic standards showed weaker and more inconsistent associations. This distinction aligns with the Model of Excellencism and Perfectionism (MEP), reinforcing the notion that it is not solely the pursuit of high personal standards that is problematic, but how these standards are experienced and expressed. The results from Study 1 helped identify conceptual gaps in the literature and provided the empirical foundation for the subsequent studies.
Study 2 (N=372) and Study 3 (N=388) used independent samples of graduate students to examine whether the distinction between perfectionistic standards and excellencism is differentially associated with the experience of impostor feelings. These studies also explored the moderating role of perceived scientific productivity and exposure to feedback in the context of the peer-reviewed process. The findings revealed that perfectionistic standards, and not excellencism, positively predicted the experience of impostor feelings, particularly at lower levels of productivity or when exposed to negative feedback. These findings provided empirical validation for the first research axis by demonstrating the importance of distinguishing between high personal standards and perfectionistic standards and their interactions with academic context.
Study 4 (N=388) used a short-longitudinal design with two time points to examine how perfectionistic standards are indirectly associated with the experience of impostor feelings through their associations with perfectionistic concerns and self-presentation. The findings supported the theorized indirect relationship between perfectionistic standards and impostor feelings and revealed a mutually reinforcing cycle, in which the experience of impostor feelings led to an increase in perfectionistic concerns and self-presentation, which in turn predicted further impostor feelings. This provides strong support for the second research axis by clarifying the underlying mechanism through which perfectionistic standards are enacted and sustained.
Overall, this thesis provided a theoretical advancement on the role of perfectionism in shaping the psychological experience of graduate students, with a particular focus on the enactment and maintenance of impostor feelings. This thesis laid the groundwork for future research aimed at examining the interplay between dispositional traits and situational pressures in graduate education. Collectively, offering theoretical, methodological, and empirical contributions to the fields of perfectionism, impostor phenomenon, and psychological adjustment in higher education