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“We are now getting a Canadian occupation”: Liberators and the Liberated in the Nijmegen Salient, 1944-45
Get PDFLiberation came at a high price to the already devastated city of Nijmegen during Operation Market Garden. It remained a frontline city for nearly seven months, during which time Nijmegen and the surrounding area came to be “occupied” by 1st Canadian Army. The presence of a friendly but foreign army was welcome but proved to be a mixed blessing as the local inhabitants sought to resume control of their lives in a time of shortages, suspension of normal morality and conflict between the Dutch themselves. The protracted stay of the Canadians after the war was frustrating for both the liberators and the liberated. The warm afterglow of Dutch gratitude to the Canadians rightly prevails today but should not lead us to see the liberation and its aftermath in solely heroic rather than in the very human terms reflected in diaries, newspapers and other sources from that unusual, chaotic time
Review of Deserters of the First World War: The Home Front by Andrea Hetherington
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Examining modulating factors of dynamic visual acuity in young adults and athletes with and without recent concussion history.
No full textVisual attention is challenged in everyday environments with exposure to busy urban scenes and access to advancing technology. In addition, high performance sport consists of unique neurocognitive and visual demands that may distinguish cognitive functioning of an experienced athlete from the general population (Faubert, 2013; Hüttermann & Memmert, 2014; van Paridon et al., 2022). In strategic team sports, such as rugby and ice hockey, athletes must quickly process constantly-evolving visual scenes and make accurate decisions to perform successful motor actions while under high levels of physical stress (Dubois et al., 2017; van Paridon et al., 2022). The ability to attend to and perceive complex visual information with additional balance and exertion demands may become compromised if an athlete sustains a sport-related concussion (SRC). A SRC is a traumatic brain injury that results in functional neurological impairments that may impact various aspects of sport performance, including cognition, vision, balance, and exercise tolerance (Broglio et al., 2009; Leddy et al., 2011; Master et al., 2016; Patricios et al., 2023; Powers et al., 2014). The following dissertation explored how previous experience (competitive sport participation and SRC) and task-related factors (balance and physical exertion) influence performance on a custom dynamic visual acuity (DVA) task in young adults.
In the first two studies, participants completed a dynamic visual acuity (DVA) task that compared, 1) varsity athletes and students from the general population and 2) varsity athletes with and without recent SRC, during different balance (standing and treadmill walking) and exertion conditions (low-intensity and moderate-intensity). The DVA task has two motion types (random walk (RW) and horizontal (H)) and is scored as the log of the minimum angle of resolution (logMAR), that is measured using an inverse scale based on the smallest target size recognized at a specified viewing distance. The effect of balance and exertion demands were analyzed by calculating a change in DVA score from seated position. The last two studies examined DVA and balance control while standing between athletes with and without recent SRC, during resting conditions, as well as before and after completing a vigorous-intensity treadmill running protocol. DVA performance was calculating using a difference from resting DVA score post-exercise and comparing RT across all time conditions. In Study 3 and Study 4, balance control was analyzed as the root mean square of centre of pressure displacement (dCOP) and variability of the high frequency COP (COPhigh) at a cut-off of 4Hz.
The results of Study 1 revealed that athletes are better at dividing attention between the DVA task during different balance and exertion conditions from seated compared to the general population during RW-motion. In Study 2, the DVA task was also sensitive to differences in DVA score from seated between athletes with and without recent history of SRC during standing and walking conditions based on spatial-temporal characteristics of DVA motion types. Overall, both athletes with SRC and students from the general population exhibited a speed-accuracy trade-off during RW-motion conditions, demonstrated by a worse relative change in DVA score from seated as responses became faster during more challenging conditions. Further, balance analysis in Study 3, revealed that athletes with recent SRC history prioritized maintaining balance with a worse change in DVA while standing. In Study 4, a vigorous treadmill running protocol seemed to facilitate DVA performance as both groups maintained performance with faster response times following exercise. However, changes in response time manifested differently following exercise between groups, such that athletes with SRC responded more slowly beyond 10-minutes of recovery.
The overall findings from this dissertation revealed that the individual experience and task-related factors do have different modulating effects on DVA for young adults. By increasing task demands (balance and physical exertion), the DVA task may further distinguish young adult athletes from the general student population. Further, recent history of SRC negatively impacted DVA performance and balance control similarly to the general population. The results suggest that the expectations for athletes with SRC should not be the same as the general population on the DVA task, such that persisting impairments may remain undetected. For rehabilitation purposes, exercise may independently help facilitate visual processing and cognitive functions for athletes with recent SRC, rather than concurrently while performing the DVA task. Overall, a DVA assessment in dual-task conditions that quantifies multiple clinical domains may be more sensitive to persisting impairments and help mitigate subsequent musculoskeletal injury risk for athletes following SRC
Experiences of Peer Interaction Amongst Autistic LGBTQ+ Youth in Secondary Institutions
Get PDFThis study uncovered the experiences of LGBTQ+ youth on the autism spectrum in Ontario secondary institutions and examined how their interactions with peers shape identity, mental health, well-being, and social belonging. This qualitative research involved interviewing six autistic LGBTQ+ youth across Ontario over Zoom. The study was guided by constructivism, critical theory, neurodiversity, and intersectionality. Results suggest that participants faced discrimination through microaggressions, peer victimization, and stereotyping, which led to feeling less safe in their school environments. Participants also had positive, affirming experiences relating to other peers standing up for them and recognizing their identities, as well as through supporting other peers that experienced similar challenges. This research has broad implications for social work practice, as it can allow social workers and youth to have a better understanding of and advocate for LGBTQ+ youth on the autism spectrum in secondary schools
Little Ship, Big Screen: Animating the Battle of the Atlantic at the Canadian War Museum
Get PDFThe Canadian War Museum developed a large-screen immersive computer-animated video experience for visitors to the Second World War gallery. It is a dramatisation of a Canadian corvette’s nighttime encounter with a German U-boat in the North Atlantic, told from the perspective of the corvette’s crew while escorting a convoy. This article examines and discusses the process of developing the upgrade, including decisions about subject matter and approach, and design and accessibility. The role of archival and historical research in defining these objectives is detailed, together with a behind-the-scenes look at the development and installation of the final product.
Le Musée canadien de la guerre a conçu une expérience vidéo immersive animée par ordinateur et présentée sur un grand écran pour les personnes qui visitent la galerie de la Seconde Guerre mondiale. Il s’agit d’une dramatisation d’une rencontre nocturne entre une corvette canadienne et un sous-marin allemand dans l’Atlantique Nord, racontée du point de vue de l’équipage de la corvette, qui escorte un convoi. Le présent article examine le processus de réalisation de la mise à jour de la galerie, y compris les décisions relatives au sujet et à l’approche, à la conception et à l’accessibilité. Le rôle de la recherche archivistique et historique dans la définition de ces objectifs est décrit en détail. L’article nous plonge également dans les coulisses de la réalisation et de l’installation du produit final
Geochemistry of Rare Earth Elements in Simulated Natural Waters: Experiments and modelling of precipitation, complexation, and bioavailability.
Get PDFRare earth elements (REEs) are an important part of modern technology and used for many applications. Mining, agriculture, improper recycling and medical applications can increase the concentration of these elements in surface waters. Metals in the environment including REEs can be found naturally but understanding the implications increase concentrations from anthropogenic inputs is important. REE mobility, persistence and toxicity is imperative to risk assessment as Canada begins to mine REE. Ultimately, as with other metals, the impacts of REEs in the environment should be dependent on the specific physical and chemical forms of the elements. Fractionation provides a practical method to understand speciation of metals. In this research, it was possible using syringe filtration and ultrafiltration to measure various fractions of europium, dysprosium and praseodymium for defined water chemistries. Fractionation results indicate that various factors, such as precipitation, organic complexation, and inorganic complexation play a role in which size fraction the REEs exist in and make interpretation complicated. The presence of DOM did increase the concentration of REE in the dissolved phase by chelating the metal and preventing precipitation, even at elevated pH. Total REE concentration influenced the fractionation trends, where increased concentrations would increase the differences between fractions (i.e. greater difference between precipitated and dissolved with increasing total REE concentration. Similar to the chemical equilibrium explored through size fractionation, bioaccumulation can also provide information about the equilibrium between chemical reactions and reactions at the biotic ligand. Including bioaccumulation experiments with Daphnia magna in the context of size fractionation can help elucidate the fractions of total metal that are available for uptake. Overall conclusions include the following; (i) the presence of DOM decreases the uptake of REE, (ii) precipitation, traditionally avoided in tests of this kind, is hard to quantify and various hypotheses are explored. Bioaccumulation experiments when compared to fractionation results do not provide clear relationships and I provide some rationalizations. Both bioaccumulation and fractionation experiments can be compared to geochemical models, in programs such as Chemical Equilibria in Aquatic Systems (CHEAQS). Finally, geochemical modelling provides another avenue to exploring the legitimacy of all of these methods aimed at assessing appropriate and accurate water quality guidelines
Authors’ Response to Review of Untold: Northeastern Ontario’s Military Past. Volume One and Two
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Authors’ Response to Review of Untold: Northeastern Ontario’s Military Past. Volume One, 1662 - World War I and Volume Two, World War II - Peacekeeping
Three Essays on Risks in the Option and CDS Markets
Get PDFThis dissertation comprises three essays investigating topics in insurance on debt and equity. The first essay utilizes patent groups as an indicator of technological proximity and demonstrates that climate risk associated with technology-related firms can predict the next quarter’s Credit Default Swap (CDS) for the focal firm. The findings indicate that a 24 basis point (bps) change in the next quarter’s CDS can be attributed to the spillover effect from technology-related companies. Sentiment analysis reveals that this outcome is primarily driven by concerns related to regulatory factors. Importantly, these results remain robust even after accounting for firm-specific characteristics and industry-fixed effects. Additionally, the observed effect is more pronounced among smaller firms with lower levels of Research and Development (R&D).The second essay investigates the COVID-19 crisis that prompted unprecedented government interventions to stabilize global financial markets. Focusing on the Federal Reserve’s intervention in the corporate bond market in 2020, we explore the implications that this credit support event had on equity and corporate bond insurance costs. Our findings reveal a significant reduction in insurance pricing for program-participating companies, indicating the far-reaching influence of the Federal Reserve’s announcements on market dynamics. This impact spans various maturities, underscoring a fundamental factor driving risk across different time frames. We employ a difference-in-difference methodology and structural credit risk modeling to quantitatively assess the credit support impact on corporate securities insurance costs. The intervention effectively mitigates credit risk, stabilizingmarket prices and altering credit perceptions among participants.The third essay sheds new light on how changes in corporate governance may impact firm value through the lens of option markets, focusing on shareholder activism via voting. Using an extensive sample of 61,150 annual shareholder meetings during the period 2003 to 2019 and associated firm- level daily option market price data, our difference-in-differences tests reveal that shareholder votingis associated with significantly greater risk reduction in option prices for contentious (treated) versus non-contentious (control) meetings. The risk reduction in long-dated option contracts, maturing post shareholder-meeting dates, arises mainly from two sources: (a) significant decreases in both implied volatility and tail risk measures, as well as (b) significant decreases in option risk from both contentious shareholder and director proposals. Our cross-sectional tests reveal that impliedvolatility and tail risk reduction are predominantly found among firms with higher information asymmetry, i.e., less competitive firms, smaller firms, and high-growth firms. Our study contributes to the literature by unpacking the effects of corporate governance changes in the context of option markets
Investigating the mobility of arsenic in subarctic mining pollution-affected peatlands near Yellowknife, Northwest Territories
Get PDFArsenic (As) is a pollutant of global concern that is detrimental to human and environmental health. Between 1948 and 2004, mining operations near Yellowknife, NT released over 20,000 tonnes of As trioxide (As2O3) that continues to persist in the surrounding landscape. Although much effort has been put into studying the chemical forms, spatial distribution, ecological impacts, and environmental cycling of As in the area, more work is needed to determine the controls of As mobility between the terrestrial and aquatic components of the landscape. Soils are known reservoirs of legacy As that can release it downslope to lakes. With climate change rapidly warming and changing the precipitation patterns of the area to include more rain in late summer and fall, soils may be more susceptible to As release than they were when most runoff occurred over frozen soils in the spring. Peat soils are of particular interest as peatlands tend to exist on the boundary between terrestrial and aquatic systems, act as hot spots of biogeochemical activity, and provide a major source of dissolved organic carbon (DOC), allowing them to act as moderators of solute movement into adjacent waters. In this study, I investigated the mobility of As in peatlands through field observations and diffusive flux modelling of four subarctic peatlands, performed a sequential extraction protocol to determine forms of As present in surficial peat, and conducted a wetting/drying experiment to simulate the effects of prolonged saturation or drought.
Peat porewater chemistry remained relatively consistent throughout the summer at each of the four study sites despite hydrologic evidence that advective fluxes should export As from three of them into adjacent lakes. As may have been retained at the peat-lake interface due to interactions between complexes of As-Fe-DOC, pH, and redox conditions. As and DOC from the surrounding catchment did accumulate in porewater at the base of an upslope ravine before being flushed by a sizeable mid-August rain event, indicating that depressions in upslope bedrock could act as collectors and sources of As. Further, diffusive fluxes modelled to provide a low-end estimate of As export into adjacent lakes were an order of magnitude larger than the expected fluxes from lake sediments, providing evidence that As fluxes from peatlands may be more important than currently known.
The majority (50-70%) of As stored within surficial peat was found to be in residual non-extractable forms that would be expected to be immobile. Much of this As is likely in the form of As2O3, as it was originally deposited decades ago, which underscores the remarkable stability of As in legacy mining emissions in the area. The remaining 30-50% of As was in extractable forms with 10-25% in forms that would be considered more readily mobile. Peat that was subjected to prolonged experimental saturation released more As and DOC than peat that remained dry. The wet treatment released As quantities that would exhaust the pool of readily mobilized As after only a few periods of saturation. This suggests that prolonged saturation, and resulting decomposition and reducing conditions facilitates the release of As held in other fractions including As bound to organic matter or Fe/Mn oxyhydroxides, or As within As2O3. The effect of the wet treatment was particularly pronounced in peat from an upland ravine site that contained more easily biodegradable vascular plants and feather mosses (Order Hypnales) than more resistant Sphagnum mosses that tend to dominate the three other sites. Therefore, upland sites could be more prone to decomposition and resulting As release due to prolonged saturation.
These results suggest that peatlands may be larger sources of As to lakes than they are currently known to be and could become even greater sources as climate change makes late summer rainfall more common. Upslope depressions can accumulate As throughout the summer before being flushed downstream with rain, while the saturation of peat from these rains may promote further release of As through changing redox conditions and enhanced decomposition of the peat
Understanding the Significance of Object Recognition in Cowbirds: Exploring the Interplay of Cognition, Social Behaviour and Reproductive Success
Get PDFEvery day, animals use cognitive processes to make decisions in their environment such as those regarding food sources, threats and mates. One such important process provides the ability to recognize objects and individuals in order to guide future actions. Since object recognition and individual recognition are related processes, they may be linked to social cognition and to fitness; links not commonly explored in the literature. In this thesis I seek to examine (1) how brown-headed cowbirds (Molothrus ater) attend to and react to novel objects in their environment and (2) how this ability to recognize objects is related to social cognition and fitness. To test object recognition, I adapted object recognition tasks commonly used in other species into a test battery suitable for a wild bird. Together these experiments evaluated object recognition, memory of an object’s location, memory of an object’s context, and finally episodic-like memory. The results indicated that cowbirds demonstrated spontaneous object recognition as well as memory for objects within a context, but did not demonstrate a distinction in changes in object location or in the episodic-like memory task. When these results were compared with the bird’s social interactions, individuals who were most reactive to novel objects and objects in an unexpected context also preferred to interact more with familiar individuals as opposed to novel individuals. This indicates that object recognition capabilities may extend to individual recognition. I also found that individuals who were most reactive to objects in a surprising context were those who were best at selecting high quality social information to imitate foraging choices. Furthermore, when comparing the results of the 4 experiments with the reproductive success of these birds, I found that individuals who performed the best on the object recognition tasks also produced fewer eggs indicating that there may be a cost associated with using cognitive mechanisms for object recognition and memory. Overall, cowbirds have the ability to identify novel objects in different contexts, and this ability relates to social behaviour and reproductive success