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Cultivating pedagogy: exploring the influence of intentional time spent outdoors on pre-service and novice educators’ teaching practice and philosophy development
Full text linkThe objective of this study was to examine how intentional time spent outdoors impacts pre-service and novice educators’ teaching practice and the development of their teaching philosophy. Current literature surrounding outdoor education is focused on the impact participation in outdoor education has on students and educators' thoughts on its implementation. Qualitative research methods were used for this study, including narrative research design, allowing participants’ voices to remain at the center of the data. Through the completion of a nature journal over the course of a four-week intervention period, four participants had the opportunity to engage with the natural world. Each participant was either a pre-service or novice teacher working in different school boards and positions. A semi-structured focus group interview was also conducted, which allowed participants to share their experience creating their nature journals. The resulting data of this study, including the results of open-ended pre- and post-surveys as well as a semi-structured focus group interview, were analyzed using narrative research methods that highlighted participants’ experiences, beliefs, and understandings. Through their participation in this study, the teachers identified the impact that spending time outdoors had on themselves and their teaching practice, including positive emotional associations, and they highlighted the issues currently surrounding outdoor education in elementary school systems such as a lack of knowledge, understanding, and external factors including weather and location. The study indicates a connection between spending time outdoors and shifts in teaching practice and personal teaching philosophy. The study further identifies areas of future research to explore this connection
Leveraging the use of Liquid Metal Channels to Reconfigure Antennas’ Impedance and Radiation Performance
Full text linkThe advent of liquid metals in the domain of RF system has opened new avenues for the researchers in smart antenna designs. Reconfigurability of antenna’s characteristics has been a keen topic of interest for the past several decades. Under this umbrella, various techniques have been employed by the designers to achieve the desired tunability. These include but are not limited to, use of varactor and p-i-n diodes, magnetic materials, ferroelectric materials, MEMS. Alongside these, embedding of metallic microfluidic channels within the antenna substrate has emerged as the most recent and novel technique. Metallic fluids, with their high conductivity and fluid nature, provide unique ideas to the designer. This thesis explores two different antenna designs that rely on EGaIn channels, a non-toxic metallic fluid, to achieve frequency switching and polarization reconfigurability. A circular patch antenna is designed at 2.5 GHz on a Rogers 5880 substrate with an integrated artificial magnetic conductor layer to boost its gain. Acrylic substrates have been used to realize EGaIn channels between the antenna and the ground plane. By optimizing the AMC for both the vacuum and metal-filled states, the design achieves efficient frequency switching from 2.5 GHz to 1.6 GHz with stable gain performance. This provides a proof-of-concept for how a switchable artificial magnetic conductor can be designed using such a technique. On the other hand, the second design validates polarization diversity with the application of EGaIn channels within the antenna substrate. A single patch antenna is shown to operate both with linear and circular polarizations using this concept at 2.5 GHz. Both the designs, i.e., polarization reconfigurable and frequency switchable, rely on microfluidic channels integrated into the acrylic substrates, allowing the antennas to switch between two or more operational states. The research thus highlights the potential of microfluidic channels to achieve reconfigurability in modern antenna systems
Variables related to cognitive functioning in MDD
Full text linkMajor Depressive Disorder (MDD) is associated with cognitive deficits, particularly in the domains of attention, memory, and executive functioning (EF). Previous research has demonstrated that residual cognitive deficits secondary to depressive disorders are associated with risk of relapse. Established treatments for depression, such as cognitive behavioural therapy (CBT) and psychotropic medications, have been shown to improve cognition in MDD. More recently, cognitive remediation therapy has been associated with improvement of cognitive deficits in depression. This project consisted of two studies which sought to investigate the relationship between several clinical variables and (a) cognitive functioning, and (b) changes in cognitive functioning following cognitive remediation training in the acute phase of major depressive disorder. Study 1 used a retrospective study method and made use of a secondary database from a tertiary-care outpatient clinic. The purpose was to investigate the relationship between two variables (number of past depressive episodes and past hospitalization due to depression) and attention, memory, and executive functioning scores on a cognitive screening
battery, in 125 individuals with acute depression, while controlling for psychiatric medication use. These two variables were unrelated to cognitive performance, after controlling for use of psychotropic medications. Study 2 was an exploratory pre-post community-based pilot study with 12 individuals with acute depression that examined the association of three clinical variables (number of comorbidities, severity of depression, and perceived cognitive deficit) with changes in memory, attention, and reasoning performance following an 8 weeks of CRT with six sessions per week. Participants completed 44.67 sessions (93.06%) with a range of 29 to 48 and showed improvement in memory scores. In univariate, but not multivariate models, comorbidity and depression severity were positively associated with reasoning and memory score increases. Findings are discussed within the context of the strengths and limitations of the studies.
Keywords: depression, cognitive functioning, cognitive remediation trainin
Computational investigations of vortex dynamics and dynamic stall of pitching airfoils at high Reynolds number
Full text linkThis study employs high-fidelity Detached Eddy Simulations (DES) and modal decompositions to elucidate dynamic stall mechanisms on a pitching NACA 0018 airfoil at = 160000. Proper Orthogonal Decomposition (POD) isolates leading‐edge separation bubbles, shear‐layer instabilities, and wake vortices by energy content, while Dynamic Mode Decomposition (DMD) and multiresolution DMD (mrDMD) reveal mode‐specific growth/decay rates and frequencies across reduced frequencies ( = 0.1,0.2,0.3) and amplitudes (=15−30°). DMD captures key events—LSB bursting, LEV formation, and DSV convection—with global modes sufficient for most cases, whereas mrDMD improves reconstruction only under deep stall ( = 0.1,=30°) These findings provide a low-order framework for predicting unsteady loads and guiding stall mitigation strategies
Upward book embeddings of DAGs: constraint-based methods and embeddability analysis
Full text linkThe k-page upward book embedding (kUBE) problem is a fundamental challenge
in graph theory with applications in circuit layout, scheduling, and hierarchical visualization.
Despite its relevance, the problem—particularly for k ≥ 2—remains
underexplored. This thesis develops practical methods for solving kUBE and conducts
a detailed investigation of how graph structural properties influence upward
embeddability.
We first propose a Boolean satisfiability (SAT) encoding, SAT-1, that extends
existing k-page book embedding techniques to the general kUBE setting. For the
special case of k = 2 (2UBE), we introduce SAT-2, a more compact SAT encoding
exploiting the fixed number of pages, and a constraint programming (CP) model as
an alternative formulation. Empirical evaluation shows that SAT solvers consistently
outperform CP, with SAT-2 achieving up to 40% faster runtimes on large instances
and up to 30× speedups on hard instances from the North dataset compared to
SAT-1.
Beyond solving efficiency, we systematically analyze how upward book embeddability
depends on structural parameters such as the edge-to-vertex ratio (m/n).
Through exhaustive enumeration and sampling, we identify sharp phase transition
phenomena across different values of k (up to k = 6) and model the phase transition
threshold as a function of graph size and page count using a power-law relationship,
providing the first quantitative characterization of this phenomenon
Feature extraction enhances model performance
No full textDeep learning has emerged as a prominent approach in traditional machine learning paradigms due to its superior capability for deep-level feature extraction. This, in turn, demonstrates that the efficiency, depth, and richness of feature extraction have a profound impact on model performance. Features serve as key characteristics for distinguishing objects and represent dimensionality-reduced representations of data. This paper proposes two effective models applied to EEG emotion recognition and NL2SQL tasks, respectively,
which enhance model performance through optimized feature extraction.
In previous models for processing EEG signals, researchers have typically focused on only partial features of EEG while rarely integrating these features comprehensively. To address this limitation, we designed a multi-feature extraction method that improves performance by extracting and combining frequency, spatial, temporal, and global features from EEG signals. We conducted extensive experiments on the SEED and DEAP datasets, generating confusion matrices, t-SNE distributions, and brain region activation heatmaps
to demonstrate the effectiveness of our model. Additionally, our method incorporates an adaptive GCN that eliminates the requirement for pre-defined adjacency matrices.
For the NL2SQL task, unlike traditional models that train from scratch, we designed a framework based on fine-tuning pre-trained BERT and conducted experiments on theWikiSQL, Academic, and Spider datasets. The results demonstrate that our model achieves superior performance compared to traditional models in clause prediction and exhibits stronger generalization capabilities, indicating that the prior knowledge embedded in pretrained models also benefits the model’s feature extraction capacity
Development of Mid-IR Laser
Full text linkWe proposed and demonstrated a mid-IR fiber laser at 1925 nm using a thulium-doped fiber as the gain medium. The designed laser needs lower pump power compared to that previously reported. The developed laser is compact and cost-effective to manufacture. We have presented the potential application of the laser in sensing gases responsible for climate change. We have developed a high-power pulsed laser at 1570 nm, which was used as the pump source for the thulium-doped fiber laser. Further, we have developed a pulsed laser at 1533 nm, which will be used as a pump source for generating a molecular gas laser using acetylene as a gain medium.
We have also introduced and demonstrated for the first time the use of an aqueous solution of gold nanorods and polyvinyl alcohol as a saturable absorber to produce pulsed and tunable pulsed lasers in the mid-IR region of the electromagnetic spectrum. We accomplished several important milestones, shaping future research endeavours in developing mid-IR lasers. Chapter 8 summarizes our research accomplishments
Industrial residuals in land reclamation: enhancing soil recovery and ecological function in disturbed glacial soils
Full text linkThis dissertation investigates the reclamation potential of industrial residuals in remediating disturbed glacial soils in Northeastern Ontario. Focusing on two distinct yet similarly degraded landscapes — abandoned aggregate borrow pits and acid- and metal-affected mixed-wood forest soils in the Sudbury region — the research explores the application of industrial by-products to enhance soil fertility, facilitate revegetation, and support ecological restoration. The study is structured around three research objectives: first, assessing passive recolonization processes and dominant functional traits in abandoned borrow pits; second, evaluating the efficacy of industrial residues, including pulp and paper mill sludge, biomass boiler fly ash, and municipal biosolids, in improving borrow pit soil fertility and facilitating vegetation establishment; and third, testing the potential of these residues to ameliorate acidic and metal-laden soils for reforestation efforts in post-mining landscapes.
The research incorporates a thorough analysis of soil and vegetation dynamics, functional trait diversity, and soil-organism interactions across experimental and natural sites. By determining community-weighted mean (CWM) and Rao’s Quadratic Entropy Index analyses, the study quantifies the functional role of plant traits in supporting ecosystem resilience and stability of abandoned borrow pits. Results demonstrate the significant but variable effects of land applying industrial solids on soil quality, with implications for both nutrient dynamics and biological activity. Notably, the application of these residues to acidic soils supports positive vegetation outcomes, particularly for pioneer and stress-tolerant species adapted to low-nutrient environments. Additionally, findings highlight the challenges associated with northern soil reclamation, including frost heave and the limited microbial and nutrient availability in exposed, compacted substrates.
The research contributes to the understanding of reclamation strategies in regenerating forest ecosystems, emphasizing the importance of tailored, site-specific amendments to improve soil health and promote sustainable land recovery. The outcomes of this thesis have broad implications for land management policies in resource-extractive landscapes, underscoring the need for long-term monitoring, adaptive management, and integrated use of local industrial by-products to restore ecosystem functionality in severely degraded soils
A spirit-led journey to relational accountability - a visiting approach to understanding interconnections between substance use, healing pathways, and mino-bimaadiziwin: conversations with Anishinabek
Full text linkThis knowledge sharing process is a complexity of interconnection. To summarize these
relational findings into an abstract is virtually impossible. However, I will summarize that
findings of this relational-based research allowed for me to continue walking a good path. We
as Indigenous researchers and knowledge gatherers must ensure that Indigenous stories stay
whole. We are knowledge gathers and should acknowledge that stories are vessels for teachings
to be passed down. These stories ought to remain together to share the words and
understandings most appropriately.
For me, it was a process consisting of more than just holding onto people’s stories, but I
also held onto their traumas and pain that they shared with me. This was an unintended
outcome for myself that I had to cope with throughout this process. When storytellers would
share these heavy burdens onto my shoulders, I would sit with these stories for weeks and
months at a time, reflecting on their journey through life. These stories often connected to me
on a personal level through familiar connections, community connections, or stories that my
late brother, Ryan, could have shared himself. There was a lot of emotional work done on my
end, as I needed to ensure I honoured these stories and people, but also protected myself and
grounded myself throughout this process. I let the heaviness ground my feet, and those feet
turned into roots that supported me throughout the remainder of this process, and arguably, for
the rest of my life.
There is a common catalyst, which speaks to shared experiences around familial
patterns of trauma(s), substance-based coping mechanisms and a cultural disconnect from
community, culture, and sense of belonging. Trauma is multifaceted and multi-layered, and in
no way does this analysis or discussion compound it into a singular understanding; I propose
here that colonial interference on families created conditions of similarity, and thus, outcomes
resulting in shared stories follow a similar pattern or series of events. The importance here lies
in understanding how trauma is a catalyst for destruction. If trauma is not faced and addressed
in a way that speaks to the depths and shadows that it lurks within, it will continue to reinforce
high-risk coping behaviours as attempts to numb and mask pain through, often, polysubstance
use.
Stories shared highlighted this concept of being born into pre-established patterns of
addiction. These realities were considered ‘normal’ everyday situations, which perpetuated
notions around not addressing traumas, but rather masking it through substance use protective
strategies. The main takeaway here is that the cyclical nature of intergenerational trauma is
limited in its understanding of how and why substances are used through the lens of masking
and numbing pain through a multi-layered familial perspective.
These specific environments produce situations of normalization, which ultimately
favour patterns of cyclical re-traumatization. The common theme spoke to the idea that coping
mechanisms such as silence was used as a way to actively avoid responsibility, accountability
or acknowledgement of child-related harms or the harms inflicted on themselves, as the parents,
in their younger years. Silence throughout the stories reinforced emotional dysregulation and
disengagement, which ultimately reinforced a positive association with coping through
substance use.
However, despite the darkness and silence of trauma and collective pain, there is a
brighter element of healing that consumed me throughout the process. Living in a good way
benefits community and collective growth. When we are living a good life, Anishinaabek
believes that our way forward is to live humbly, to lead with love and compassion, even in the
face of racism and hatred, as Anishinabek can see good in all things when we come from a
place of healing and understanding. However, it is important to note that living according to
Anishinaabek customs and protocols truly means living according to these ways of life.
Mino-Bimaadiziwin is a substantial and complex way of life. It is an understanding that is
unique to the person who is explaining it, and everyone can explain it differently. However, it is
founded on living and walking a good life. Relational-based knowledge gathering is exactly
what is described above. It is complex and sensitive, but relational knowledge gathering is
fundamentally a process of healing, collectively and individually.
Healing is a connection. Mino-Bimaadiziwin is a subjective understanding of what is
important to an individual and how they walk the path to healing, meaningfully feeding the
spirit within. Healing is the Circle, and being actively involved in deciding what is important to
you on your journey to (re)connecting. Relational understanding around healing is creating
space and a place that welcomes many truths which originate from collective Indigenous
experiences
Predator-prey interactions under thermal pressure
Full text linkEctotherms' ecological performance is directly linked to their thermal environment, many
of which are warming due to climate change. If predator and prey thermal niches differ,
warming may impact the intensity of predator-prey interactions, with subsequent effects
on their populations. To determine how warming may impact predator-prey interactions, I
fit and compared maximum swim speed thermal performance curves (TPCs) of
Dytiscidae predaceous diving beetles (Tribe Agabini) and their prey, Wood Frog
(Lithobates sylvaticus) and Eastern Gray Treefrog (Dryophytes versicolor) tadpoles. I
then used climate change projections and measures of pond water temperature to
determine how relative swim speeds of predators and prey may change in the future. Due
to a lack of predicted future water temperature data, I established an air-water
temperature relationship by fitting a generalized linear model (GLM) to 2024 air and
water temperatures from 5 sites north of Thunder Bay, Ontario. I then used predicted air
temperature data for 2025-2100 and my GLMs to get predicted water temperatures for
the next 75 years. TPC comparisons between Agabini predators and tadpole prey revealed
that predators have a performance advantage over D. versicolor tadpoles at warmer
temperatures, but not L. sylvaticus tadpoles. Agabini beetle thermal optimum (Topt) (28.6
± 1.6 ºC) was also significantly greater than D. versicolor (24.2 ± 0.9 ºC, p = 0.025), but
not significantly different from L. sylvaticus (25.7 ± 3.2 ºC, p = 0.163). Agabini beetle
80% thermal tolerance breadth (Tbr(80%)) (13.5 ± 0.9) was significantly narrower than D.
versicolor (18.1 ± 0.9, p = 0.040) but not significantly different from L. sylvaticus (19.1 ±
2.7, p = 0.162). Predictions showed that pond temperatures will increase through time,
giving Agabini beetle predators an increasing performance advantage over D. versicolor over the next 75 years. However, due to similar performance measures between L.
sylvaticus and the predators, their interaction will not be impacted by temperature
changes over the next 75 years. These results show variability between predator-prey
pairs in the same environment. When the predator's performance advantage over their
prey increases, it may result in increased predation pressure and reduced prey
populations, while other predator-prey interactions will be unaffected. Thus, as climate
change alters thermal regimes, predator-prey interactions will be altered, but not between
all predator-prey pairs