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Unraveling the metabolic networks involved in the utilization of L-glutamine in Pseudomonas fluorescens exposed to nutritional stress
No full textSulfur plays an essential role in oxidative homeostasis due to its participation in sulfhydryl
groups (SH). A disruption of this vital nutrient is known to promote oxidative stress and activates
a plethora of anti-oxidative strategies. Phosphate, a micronutrient that is part of adenosine
triphosphate (ATP), the main molecule used as energy and other macromolecules in living cells.
The stress response to sulfur and phosphate deficiency in Pseudomonas fluorescens was
investigated with emphasis on ROS detoxification, and energy production. Metabolite profiling
was performed by High Performance Liquid Chromatography (HPLC), enzymatic analysis was
done using Blue Native Polyacrylamide Gel Electrophoresis (BN-PAGE) and gene expression
assessment of targeted genes was performed with SYBR-Green real-time PCR (qPCR). When
cultured in a sulfur-deficient medium with glutamine as the sole carbon and nitrogen source, the
microbe reconfigures its metabolism aimed at the enhanced synthesis of NADPH, an antioxidant
and the limited production of NADH, a pro-oxidant. The up-regulation of isocitrate
dehydrogenase (ICDH)-NADP+ dependent in the soluble fraction of the cells obtained from the
S-deficient media results in enhanced NADPH synthesis. This reaction is aided by the
concomitant increase in NAD kinase (NADK) activity. The latter converts NAD+
into NADP+
in
the presence of ATP. Additionally, the microbe reprograms its metabolic pathways to produce
KG and regenerate this keto-acid from succinate, a by-product of ROS detoxification. Succinate
semialdehyde dehydrogenase (SSADH) and KG decarboxylase (KDC) work in partnership to
synthesize KG. This process is further aided by the increased activity of the enzymes glutamate
decarboxylase (GDC) and γ-amino-butyrate transaminases (GABA-T). Taken together, the data
point to a metabolic network involving isocitrate, KG, and ICDH that converts NADH into
NADPH in P. fluorescens subjected to a S-deprived environment. Finally, when cultured in low
phosphate environments, the microbe can produce ATP via substrate level phosphorylation
(SLP), in a mechanism involving the reductive isocitrate dehydrogenase (ICDH-NADH),
isocitrate lyase (ICL), malate synthase (MS) as well as phosphoenol pyruvate carboxylase
(PEPC), phosphoenol pyruvate synthase (PEPS) and pyruvate phosphate dikinase (PPDK). This
metabolic reprogramming ensures the survival of the microbe and reveals the central role
metabolism plays in cellular adaptation to abiotic stress.Doctor of Philosophy (PhD) in Biomolecular Science
Architecture as actant for protest: solidarity with Amiskwaciwâskahikan’s (Edmonton) unhoused community
No full textConditioned by neoliberal imperatives and settler colonial impositions
of ‘property’, architecture is complicit in upholding spatial and social
inequities. The neologism ‘houselessness’ foregrounds housing as
a human right, which must be addressed through the provision of
accessible housing, yet this process is slow. Moreover, unhoused
individuals are disproportionately affected by pandemics. Their
aggravated health risks owe to crowded shelters, comorbidities, and
pandemic-related restrictions of supportive services. While COVID-19
has worsened the pre-existing houselessness crisis, some immediate
effects may be addressed locally through mutual aid: a form of rapid
response and community care that demonstrates both the need for
bottom-up solutions and interim approaches to houselessness. This
thesis explores how architecture might challenge existing frameworks
of power to act in solidarity with houseless neighbours. The series of
design interventions proposed for Edmonton, Alberta, focus on sociospatial relationships — related to water, sanitation, and hygiene — that
act in solidarity with houseless people.Master of Architecture (M.Arch
Holistic arts-based mindfulness program with older adults at a slow-paced rehabilitation hospital: deepening skills of working with older adults
No full textOlder adults have historically been excluded from research (Jacelon, 2007). This issue is
highly problematic as the current rate of growth for the older adult population is the highest in
recorded history (UN, 2022). Older adults have unique experiences with mental and physical
health, yet those who work with this population are repeatedly shown in the literature to have
inadequate professional training and knowledge of best practices (Buttigieg et al., 2018).
Perceptions of older adults from the vantage point of both health care professionals and older
adults themselves are immensely impacted by the pervasiveness of ageism, resulting in
misinformation, stereotypes, and the implementation of inappropriate interventions. Impacts of
ageism can include low self-esteem, depression, and anxiety, resulting in lower quality of life.
The Holistic Arts-Based Mindfulness Program (HAP) was introduced to older adults at St.
Joseph’s Continuing Care Centre (slow-paced physical rehabilitation hospital) as an anti-ageist,
non-pharmacological intervention to positively affect mood and overall sense of wellbeing. HAP
proved to be more challenging to implement than anticipated due to scheduling, COVID-19
restrictions, and internalized ageism on the part of patients. The program was adapted to a 1:1
delivery method to address these challenges. The results of this 1:1 delivery had benefits for
patients, including the active resistance of the Foucauldian notion (Foucault, 1995) of docile
bodies in an institutional setting, thus leading to a more patient-centred approach. HAP allowed
space for patients to recognize their strengths and explore their feelings while rehabilitating.
Social workers should consider the use of 1:1 arts-based mindfulness interventions when
working with patients in a slow-paced physical rehabilitation hospital setting as an integral tool
in the healing process.Master of Social Work Progra
Impacts of a windfarm and wildfire on the spatial ecology and habitat selection of an endangered freshwater turtle
No full textWind is a source of renewable energy, and its use is projected to increase as governments look for
solutions to reduce carbon emissions. Although wind energy presents many advantages,
windfarms can pose risks to wildlife. I used a post-hoc design to investigate whether body
condition, spatial ecology, and multiscale habitat selection by spotted turtles (Clemmys guttata)
differed among three treatment sites in central Ontario: Control, windfarm (Wind), and combined
post-wildfire and windfarm (Windburn). I outfitted 9-10 turtles per treatment with VHF radio
transmitters and tracked them approximately twice per week throughout the active season. Body
condition, home range size and minimum daily distances moved by turtles did not differ among
treatments, but it is possible that I did not detect acute responses to the habitat modification
because turtles may have had sufficient time to adapt their behaviours as my study was conducted
2 years post-construction and 2.5 years post-wildfire. Turtles did not avoid habitats near turbines
or roads but also did not cross roads unless a semi-aquatic culvert was present, highlighting the
need to maintain habitat connectivity. In Windburn, turtles used wet depressions on rock barrens
while Control and Wind turtles did not, possibly because Windburn turtles were exploiting new
early successional macrohabitat resulting from the wildfire; however, pre-wildfire movement data
would be required to confirm cause. In all treatments, turtles selected microhabitat based on
temperature, water depth, available cover, and hummock presence, suggesting that turtles were
able to find suitable microsites in the modified landscapes of my study area. My study is one of
the first to assess the impacts of windfarms on semi-aquatic turtles, an at-risk and understudied
taxon on windfarms, but more research is required to understand the acute and long-term impacts
of windfarms and wildfires on turtles to inform data-driven mitigation strategies.Master of Science (MSc) in Biolog
Enhancing the immune responses using the synergistic effects of TLR4 and NOD2 agonists for multifaceted vaccine development
No full textEffective and defined adjuvanted vaccines can provide enhanced immunity to intra-cellular pathogens,
which disproportionately affect certain immunocompromised individuals. Also, the importance of T-cell
mediated immunity is vital in reducing the severity of intra-cellular infections. Strategies to increase
vaccine immunogenicity include the addition of innovative adjuvants, which can help to achieve robust
and persistent immune responses against infectious diseases. Despite the indispensable importance of
adjuvants, only an extremely limited number of adjuvants have been included in licensed vaccines. That
is why a search for more effective adjuvants has become one of the primary concerns in medical
research. Simultaneous stimulation of germ-line encoded pattern-recognition receptors of the innate immune
system, particularly Toll-like receptors (TLRs) and Nucleotide oligomerization domain (NOD)-like
receptors (NLRs) can augment the cellular immune response. With this in mind, I hypothesized that
adjuvants that activate TLR of NLRs would enhance vaccine response. To study this we developed a
bioassay model of cytokine secretion using murine immortalized and primary antigen presenting
cells(APCs), which were stimulated with diethanolamine-based lipid A (A1), a synthetic lipid A TLR4
agonist, and muramyl dipeptide (MDP),a NOD2 agonist in the presence or absence of the currently
available high-dose influenza vaccine, Fluzone®. We evaluated the immune response by measuring
cytokine secretion, protein cell signaling, and cell surface markers. We showed that A1 in combination
with MDP was able to induce enhanced early innate immune responses synergistically by increasing
ERK1/2 phosphorylation and increasing proinflammatory cytokine secretion. Next, we assessed the A1-
MDP adjuvanted-Fluzone vaccine formulation against drifted influenza virus A/H3N2 variants in an
antigen challenge protocol on human peripheral blood mononuclear cells (PBMCs). There were
significant enhanced releases of IFNγ, IL-6, and IL-1β with no significant changes in IL-10 secretion and increased expression of CD8+ T (cytolytic T cell) cell surface markers, which suggested a polarized
antigen-specific Th1 immune response. In summary, our combined adjuvant approach will ameliorate
current vaccines especially for intracellular infections.Master of Science (MSc) in Biolog
Gene regulation and global DNA methylation mechanisms involved in white spruce (Picea glauca) response to copper toxicity
No full textPlants require metals to survive, but an excess of metals can have phytotoxic effects. The
objectives of this study were to 1) analyze the transcription of genes associated with copper
resistance (RAN1, MT2b, and MRP4) and 2) assess the effects of copper and potassium on global
DNA methylation in white spruce (P. glauca). Seedlings were treated with three concentrations of
copper sulfate including 1,312 mg/kg, 656 mg/kg, and 130 mg/kg. Potassium sulfate and water
used as controls. DNA and RNA were extracted from roots and needles. The levels of gene
expression were measured using RT-qPCR and the global 5 methyl cytosine was assessed using
the Abcam ELISA kit procedure. Overall, the highest concentration of copper sulfate (1,312
mg/kg) induced the most severe damages to plants compared to the 656 mg/kg and 130 mg/kg
concentrations. Copper ions at the 1312 mg/kg concentration induced an upregulation of the MRP4
gene in roots and needles. The 656 mg/kg concentration of copper sulfate and potassium sulfate
induced an upregulation of MRP4 only in needles. The MT2b gene was upregulated in roots when
plants were exposed to 1,312 mg/kg of copper sulfate, but was downregulated in genotypes treated
with 656 mg/kg of copper sulfate in both tissues, compared to the water control. The RAN1 gene
was upregulated in roots treated with 1,312 mg/kg copper sulfate. Differential expression of
RAN1, MT2b, and MRP4 genes were observed in copper-resistant and susceptible genotypes. The
present study revealed that potassium ions induced a hypomethylation of DNA at the 1,312 mg/kg
concentration while copper did not induce changes in the level of global cytosine methylation.Master of Science (MSc) in Biolog
Forward modeling and 3D inversion of electromagnetic data collected over the McArthur River uranium deposit in the Athabasca Basin, Canada
No full textDetection and assessment of the deeply buried high-grade uranium deposits in the Athabasca Basin rely on geophysical methods to map conductive rocks. Variable Quaternary surface cover can mask the anomalous signals from depth and affect the interpretation of inverted conductivity models. We present the analysis of several electromagnetic (EM) modeling studies and two field data sets to demonstrate the effects of varying Quaternary cover resistivity and thickness, on the ability to resolve the parameters of underlying sandstone, alteration, and basement conductors. Synthetic data, assuming a typical shallow EM sounding system and realistic resistivities found in the Athabasca Basin, indicate that resistivity and thickness parameters of the Quaternary cover can be separately recovered in cases in which this cover is more
conductive than the underlying sandstone, but not when the cover is significantly more resistive. A 3D modeling study indicates that by using airborne EM data, it is possible to detect a basement conductor of 20 S at a depth of at least 600 m below the surface, even in the presence of Quaternary cover thickness variations of the up to 20% (40–60 m). Furthermore, although Quaternary cover variations and deeper sandstone alteration can
produce comparable anomalous signal amplitudes in a time-domain EM response, their effects are most visible in distinctly separate time windows. Ground-penetrating radar and other data to characterize the Quaternary cover in the McArthur River area indicate that this cover consists mostly of sandy tills ranging in thickness from 0 to 117 m. Constrained 3D inversion of an airborne EM data set from the same area indicates basement conductors consistent with the depth and location of a known fault. Elevated conductivity in the sandstone by up to a factor of two over the background values could indicate possible alteration
The role of the Non-neuronal Cholinergic System in immune regulation
Get PDFActivation of nicotinic acetylcholine receptors (nAChRs) by agonists like acetylcholine
(ACh) can have anti-inflammatory properties via the regulation of cytokines. A recent novel
class of nAChR specific molecules termed silent agonists are also thought to induce nAChRdependent metabotropic signaling cascades, while causing very little channel opening. These
molecules may therefore be potent immune regulators. This study assessed the expression of
cholinergic genes in human macrophages and gained insights on the anti-inflammatory
properties of nAChR agonists, silent agonists and cholinergic inhibitors in human macrophages.
For both aims, two human monocytic cell lines (THP-1 and U937) were cultured and
differentiated into macrophages using phorbol 12-myristate 13-acetate (PMA) to obtain Mo
macrophages and in some cases, further polarized into M1 (INF-γ) or M2 (IL-13 and IL-4).
Expression of cholinergic genes were first determined via Western Blot and PCR. Secondly,
experiments assessing expression of cell markers, cytokine expression, and viability were carried
out following treatment with various conditions in the presence of LPS. It was hypothesized that
macrophages would express cholinergic proteins and that nAChR agonists/silent agonists would
result in anti-inflammatory responses whereas cholinergic inhibitors would result in proinflammatory responses. Overall, we found that differentiated macrophages expressed most
cholinergic proteins and that the inhibition of cholinergic proteins and nAChR agonism
modulated LPS-induced cytokine release. These experiments gave pertinent information
regarding the presence of cholinergic genes and the anti-inflammatory properties of
agonists/silent agonists in human macrophages.Master of Science (MSc) in Chemical Science
Low carbon living: an alternative (sub)urban housing framework for a rapidly growing city
No full textPost-war immigration, along with the Baby Boom
dramatically increased metropolitan populations generating
a demand for new housing where suburbanization was the
solution. It is in part responsible for the contemporary
cities that we live in today, and that are now at the root
of the climate crisis. Suburban developments imposed
challenges of disconnections between neighbourhoods,
services, and amenities within cities that were solved with
the implementation of vehicles. This thesis project explores
new housing strategies that emphasize how low carbon
architecture and lifestyles can be implemented into growing
cities to minimize the impacts on climate change and avoid
the rampant disconnections of the urban fabric. A sustainable
urban development framework has been developed to create
a denser and more liveable neighbourhood in the context
of Barrie, Ontario, a rapidly growing bedroom community
outside of Toronto.Master of Architecture (M.Arch
Investigating how individuals respond to efforts to contain the COVID-19 pandemic in Northern Ontario: associations with political ideology and perceived stress
No full textThe COVID-19 pandemic has required individuals to adopt new attitudes and behaviours
that promote public health, such as mask wearing, social distancing and vaccination. The current
research sought to understanding the factors that influence attitudes and behaviours related to
these responses by investigating the association of political ideology and perceived stress on
attitudes and behaviours towards COVID-19 in Northern Ontario. Overall, a right-leaning or
conservative/libertarian political ideology was associated with decreased support of government
measures towards COVID-19, lower levels of perceived concern over COVID-19, and less
favorable attitudes and reduced uptake of the COVID-19 vaccine. Additionally, while perceived
stress was not found to be related to political ideology, moderate stress was found to be
associated with lower levels of perceived severity and concern about COVID-19, and less
favorable attitudes towards the COVID-19 vaccine. Implications of the current study are useful
for understanding reactions to future pandemics and public health crises.Master of Arts (MA) in Psycholog