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The potential uses of virus-infected symbionts to improve drought and heat stress in trees for improvement, climate change resilience, and restoration
Get PDFWith the rapid changes occurring to the climate of the boreal forest, many
populations of trees are facing increased stresses and seeing lower productivity and
survival. Conventional tree improvement programs take decades to come to fruition and
may not provide extensive enough benefits to tackle changing conditions. Curvularia
Thermal Tolerance Virus (CThTV) has the capacity to dramatically improve the heat
stress resilience of its host by activating the basic stress response genes of a mutual
endophytic fungus within the plant host. This novel system has the potential to be
introduced into economically important trees using endophytic fungi and/or mycorrhizal
species as vectors. If successful, this virus would confer significant relief from a large
variety of environmental stressors, and be persistent across generations of plants on-site,
without being a risk to the genetic diversity of the host population
Late Holocene paleovegetation and fire history of Northern Lake of the Woods and the Woodland Period
Get PDFThis thesis analyzes two Late Holocene lake sediment cores which were collected from
the vicinity of two archaeological sites in northeastern Lake of the Woods, Ontario: the
Bundoran Site (DjKn-5) and the Bud Site (DjKn-6). One of these cores was collected from a
small pond between these sites and the other core was collected from the middle of a large bay in
Lake of the Woods northwest of the sites. Both cores contain roughly 2000 years of
sedimentation and the charcoal and pollen content are used to reconstruct local- and regionalscale vegetation history, changes in fire history, and the possibility of human impacts on
vegetation during this period within the study area. The pollen sequences from both cores
revealed the presence of a persistent pine-dominated forest environment, however the Bundoran
Pond core showed greater levels of pollen loading from grasses, likely as a result of the
differences in basin size between the pond and the bay. The pollen and charcoal sequences in the
Route Bay core showed evidence of disturbance towards the top of the core that was not seen at
Bundoran Pond. This is interpreted as representing a period of vegetation disturbance in the
wider Lake of the Woods basin, but one of vegetation continuity surrounding the pond. The
Bundoran Pond core also consistently contained charcoal fragments larger than 100 µm2,
something which was not seen in the Route Bay core. This is interpreted as possibly representing
anthropogenic burning near the pond. The Route Bay core contained a maize (Zea mays) pollen
grain in its basal interval (70-72cm below surface), which had an associated radiocarbon date of
2120 ± 30 14C years BP (195 BCE to 105 BCE). This maize pollen grain provides the first
definitive evidence of precontact maize cultivation in the Lake of the Woods region
Evaluating the effects of clearcutting, wildfire, and bioenergy wood ash application on forest soils to improve emulation silviculture
Get PDFOntario’s forest management guides promote the use emulation silviculture to manage
the province’s forests on a landscape scale based on natural disturbance regimes. While clearcut
harvesting can have similar effects to wildfire such as the removal of vegetation, creation of edge
habitat, as well as increasing nitrogen cycling and decomposition rates, it lacks the chemical
impacts associated with fire and ash deposition. This thesis compared published studies from
North America, Europe, and Asia and found that there are similarities between harvesting and
wildfire on boreal forest floors and soil characteristics. Harvesting and wildfire can have a
similar effect on base cation pools such as calcium, as well as forest floor and soil pH, though
fire’s impacts are more substantial. Upon examination of European and Canadian bioenergy
wood-ash trials, the application of ash on post-harvest forest soils could benefit certain sites and
improve current emulation silviculture techniques
Programming pedagogy in the age of accessible artificial intelligence
Get PDFIn recent years, new teaching opportunities have emerged as artificial intelligence has gained
increasing attention in computational thinking education. However, to design effective pedagogy based on the present research landscape, the technology solution must be tailored
to a learning environment through a collaboration between human-computer interaction
and human-artificial intelligence interaction research. The thesis aims to enhance programming experiences and increase accessibility to programming resources for students in remote schools and post-secondary graduate settings using human-computer interaction and
human-artificial intelligence interaction techniques. It addresses the limited computational
thinking education resources and the potential of artificial intelligence-assisted coding in a
self-learning method suitable for remote Northwestern First Nation communities in Canada.
This thesis proposes methods to cater to students’ learning styles in two different learning
environments using human-computer interaction for kindergarten to grade 12 students and
human-artificial intelligence interaction for university students. Incorporating these research
principles can help novice programmers overcome cognitive overload and poor user experience
and achieve an optimal user experience. The thesis begins with bibliometric analysis and
provides a holistic perspective of computational thinking and artificial intelligence trending
strategies. It then presents an empirical study on human-computer interaction, investigating
computational thinking in remote kindergarten to grade 12 schools with blended learning
environments. It also presents another empirical study on human-artificial intelligence interaction to experiment with a self-learning style for artificial intelligence coding assistants for
university students using massive open online courses. [...
Stigma resistance versus self-stigma in university students with mental health problems
Get PDFSelf-stigma is the process by which an individual is aware of, agrees with, and internalizes
demeaning societal stereotypes and prejudices. Stigma resistance is when an individual may be
aware of societal stigma, yet they ignore or challenge the stereotypes and resist internalizing
stigma. This current research examined self-stigma and stigma resistance in the realm of mental
health help-seeking and mental illness (i.e., depression and anxiety). I aimed to investigate how
intrapersonal factors and life experiences contributed to mental health stigma resistance. Study 1
employed online mixed method research with 366 participants to explore how self-compassion,
self-coldness, and mental health self-efficacy may impact stigma resistance and potentially
moderate the relationship between perceived and self-stigmas of help-seeking and of depression
and anxiety. Study 2 utilized an Interpretive Phenomenological Analysis (IPA) approach with
five participants with depression or anxiety to explore their lived experiences of resisting mental
health stigma. Study 1 revealed that self-compassion had an approaching significant moderating
effect on self-stigma of help-seeking, and self-efficacy had a significant moderating effect on
self-stigma of depression and anxiety, yet self-compassion and self-efficacy, but not self-coldness, had main effects on mental health stigma resistance. Study 2 constructed six
superordinate themes of stigma resistance: accepting one’s mental health experiences,
transparency about mental health experiences, blocking public stigma, taking actions to better
oneself, receiving social support, and extending stigma resistance to others. Rather than focusing
on reducing negative psychosocial factors, these findings point toward empowering traits and
experiences that can be targeted to increase stigma resistance
The face of Homo floresiensis: an investigation of scale
Get PDFThe face of Homo floresiensis has been described as small in absolute and relative size,
comparable to the condition observed in modern humans (Homo sapiens). It has even been
claimed that LB1’s relative facial dimensions are broadly similar to other fossil hominin crania
that have extremely small faces in relation to their cranial vaults, such as Asian Homo erectus
and the Dali cranium. The idea that LB1 shares a proportionately small face with some but not
all species in the genus Homo is a key component of the hypothesis that Homo floresiensis is an
island-dwarfed descendant of Asian Homo erectus. Here I test two specific questions in terms of
the relative external size/shape of LB 1’s facial skeleton. First, can LB 1’s relative facial size and
shape be accommodated within the ranges of variation for a worldwide sample of normal,
nonpathological, modern humans? [...
Reduction of switching losses and passive components rating in series-connected current source inverters
Get PDFThe current source inverter (CSI) is widely used in medium voltage drives due to its simple
configuration, reliable short-circuit protection, and low dv/dt issue. Conventional series-connected current
source inverters (SC-CSI) are constituted of several current source inverters (CSIs) connected in series
through multi-winding transformers to enhance the power capacity. It is very promising in high-voltage
applications. Switching losses of the semiconductor switches significantly impact the power efficiency of
SC-CSIs. Therefore, inverter design must consider these losses, which depend on factors, such as switching
frequency, modulation schemes and semiconductor parameters.
This thesis aims to reduce the switching losses of conventional SC-CSIs by decreasing the
switching frequency from 540 Hz to 360 Hz and eventually to 60 Hz. In Chapter 2, the switching frequency
is reduced to 360 Hz for the switching loss reduction. The active damping control is implemented to mitigate
the increase in filter capacitance caused by the lower switching frequency. Chapter 3 is to further reduce
the switching losses by reducing the switching frequency to 60 Hz. However, this strategy results in a
significant increase in the passive components. To address this issue, the multi-winding transformer is
replaced with a phase-shifting transformer, as the active damping method applied in Chapter 2 is no longer
effective at this reduced frequency. The switching losses and the passive components of SC-CSIs are
investigated with switching frequencies of 540Hz, 360Hz and 60 Hz. Simulations are conducted using
MATLAB/SIMULINK to verify the investigation
The office for standards in education and the pupil premium grant: primary educators’ understanding and experiences of inspection criteria
Get PDFThis thesis explores the Office for Standards in Education (Ofsted) Education Inspection
Framework and its link to the Pupil Premium Grant (PPG) within England’s primary education
system. The Ofsted framework enables inspectors to rate schools with one of the following
designations: outstanding, good, requires improvement, or inadequate. By interviewing three
primary educators at various stages of their careers, this thesis primarily endeavours to
understand the role of Ofsted in relation to the PPG. A secondary goal is to identify the ways
those educators respond to factors that cause pupil deprivation while also working towards
closing the attainment gap between disadvantaged pupils and their peers. The psychological
approach to narrative inquiry, as described by Merriam and Tisdell, is employed so that focus
can be placed on the personal thoughts and motivations of the participants (2015, p. 35). To
achieve an outstanding designation, schools must show that they have closed the attainment gap
between pupils who receive the PPG and those who do not. The literature review shows that
deprivations faced by some pupils are outside the control of schools and therefore the provision
of additional funding to schools does little to impact the root cause of such deprivations. This
thesis concludes with a discussion of how primary educators use their scope of influence to
reduce the attainment gap. Research has found no link between school inspections and
improvement or that the PPG funding has closed the attainment gap calling into question their
efficacy in improving the social mobility of disadvantaged pupils. Finally, this thesis positions
this study in a post-pandemic climate alongside a recruitment and retention crisis that has led to
teaching unions initiating strike action
Crosslinked lignin-starch polymers with alternative applications
Get PDFLignin is a complex biopolymer obtained as a by-product from the delignification of wood and grasses. Starch is also a natural polymer of amylose and amylopectin found in many plants, featuring a relatively simple structure and limited solubility in water. Lignin and starch are abundant and inexpensive biopolymers that are often considered sustainable alternatives to oil-based and synthetic polymers. Despite their abundance, and owing to their physicochemical properties, starch and lignin have limited usages as their pristine forms in industrial, high-performance, and food applications. In the last ten years, studies regarding the combination of starch and lignin for producing reinforced materials such as films, coatings, and adhesives have increased significantly. The incorporation of lignin into starch matrices produced materials that were more resistant to water, UV radiation, mechanical stress, and thermal changes. This thesis explores the state of the art for the production of starch-lignin materials, focusing on the physicochemical properties of the starch-lignin materials and the outcomes, challenges, and opportunities for this field. [...
Federated learning framework and energy disaggregation techniques for residential energy management
Get PDFResidential energy use is a significant part of total power usage in developed countries. To reduce overall
energy use and save funds, these countries need solutions that help them keep track of how different
appliances are used at residences. Non-Intrusive Load Monitoring (NILM) or energy disaggregation
is a method for calculating individual appliance power consumption from a single meter tracking the
aggregated power of several appliances. To implement any NILM approach in the real world, it is
necessary to collect massive amounts of data from individual residences and transfer them to centralized
servers, where they will undergo extensive analysis. The centralized fashion of this procedure makes it
time-consuming and costly since transferring the data from thousands of residences to the central server
takes a lot of time and storage. This thesis proposes utilizing Federated Learning (FL) framework for
NILM in order to make the entire system cost-effective and efficient. Rather than collecting data from
all clients (residences) and sending it back to the central server, local models are generated on each
client’s end and trained on local data in FL. This allows FL to respond more quickly to changes in the
environment and handle data locally in a single household, increasing the system’s speed. On top of
that, without any data transfer, FL prevents data leakage and preserves the clients’ privacy, leading
to a safe and trustworthy system. For the first time, in this work, the performance of deploying FL
in NILM was investigated with two different energy disaggregation models: Short Sequence-to-Point
(Seq2Point) and Variational Auto-Encoder (VAE). Short Seq2Point with fewer samples as input window
for each appliance, tries to simulate the real-time energy disaggregation for the different appliances.
Despite having a light-weighted model, Short Seq2Point lacks generalizability and might confront some
challenges while disaggregating multi-state appliances