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Amber Hussain - Abstract 15 - Innovate Conference 2025
No full textThe Global Nursing Office (GNO) of the Faculty of Nursing (FoN) has shaped
global nursing education and practice. This historical study examines the development, contributions and challenges of GNO
Lori Suet Hang Lo - Abstract 66 - Innovate Conference 2025
No full textPeople receiving dialysis commonly experience anxiety symptoms, yet mental healthcare for them is scarce and the problem remains under-addressed. Given that both mental healthcare and kidney care are complex and characterized by contextual factors, what works in one situation might not work in another, leading to unpredictable outcomes. However, there is a lack of understanding of how and why mental healthcare works for people receiving dialysis and experiencing anxiety symptoms which makes the provision of effective care challenging
Evaluating Anaerobic Digestion of Source-Separated Organic Solid Wastes Using a Pilot Anaerobic Digester
No full textAnaerobic digestion (AD) is a promising technology for the sustainable management of organic wastes and methane production. This study evaluated the performance and microbial community dynamics of a pilot-scale anaerobic digester treating raw source-separated organic (SSO) solid wastes under mesophilic conditions. The digester operation was divided into phases to assess the effects of feedstock composition (yard waste versus food waste), organic loading rate (OLR), and pH adjustment on methane yield and digester stability.
The results demonstrated that switching from yard waste to food waste significantly enhanced methane production, with methane yield increasing from 0.20-0.27 m3 CH₄/kg VS during Phase I (yard waste digestion) to 0.46-0.56 m3 CH₄/kg VS during Phase II (food waste digestion). However, as OLR increased, acidification occurred during Phase III, resulting in a drastic reduction of methane yield. Notably, despite the acid stress, Methanosaeta remained the dominant methanogen during the acidification phase, indicating its ability to persist under high acetate concentrations, likely due to its dense aggregation and resistance to acidic environments.
Acid-tolerant fermentative bacteria, such as Lactobacillus, Bifidobacterium, and Caproiciproducens, proliferated during acidification, rapidly converting carbohydrates to acetic and lactic acids, further exacerbating the acid stress and inhibiting methane production. After pH adjustment using NaOH and NaHCO₃, partial recovery of methane production was observed, although the microbial community did not fully revert to its pre-acidification state. Following pH stabilization, Methanosarcina regained dominance, reflecting its superior resilience and rapid recolonization capacity once favorable conditions were restored.
This study highlights the critical need for maintaining stable OLR and pH conditions to support balanced carbon utilization and robust methane production. Future research should focus on optimizing loading rates and enhancing microbial resilience to environmental stress to improve anaerobic digestion performance and stability
Water Treatment Resistance, Antimicrobial Resistance, and Pathogenicity in Klebsiella pneumoniae Isolates from Alberta Sewage
No full textWater treatment represents a critical barrier to the transmission of infectious diseases.
There is evidence that some bacteria may be developing resistance to the disinfection processes
commonly applied in water treatment. Previous work revealed that certain strains of Escherichia
coli, including pathogenic strains (e.g., extraintestinal pathogenic E. coli [ExPEC]), appear
capable of resisting both wastewater treatment and antimicrobial drugs. This thesis investigated
whether a similar phenotype of water treatment resistance exists in the Klebsiella pneumoniae
species complex (KpSC), and whether it may also co-occur with antimicrobial resistance or
pathogenicity. The KpSC is a group of largely opportunistic pathogens known for their
environmental ubiquity and their tendency to exhibit high levels of antimicrobial resistance
(AMR).
Twenty-one KpSC isolates were obtained from sewage samples treated with a chlorine
dose sufficient to kill 99.99% of coliform bacteria. These chlorine-resistant KpSC isolates were
tested for heat resistance, a phenotype linked to chlorine and advanced oxidant resistance
through the transmissible locus of stress tolerance (tLST). Overall, 18 KpSC chlorine-resistant
isolates (86%) exhibited an elevated heat resistance phenotype relative to clinical control strains.
Whole genome sequencing revealed that that nine of the isolates harbored the transmissible locus
of stress tolerance (tLST). Other chlorine-resistance mechanisms were also examined, including
biofilm formation and hypermucoviscosity. Substantial biofilm formation was observed in only
two isolates, and most isolates produced biofilms at a level equal to, or less than, the biofilm
production seen in a positive control strain. However, five isolates were hypermucoviscous based
on the string test.
Susceptibility to 17 clinical antimicrobials was also evaluated using VITEK®2
ASTGN98 cards. All 21 isolates were phenotypically susceptible to most antimicrobials at
clinical/veterinary breakpoints, and although they carried a large complement of antimicrobial
resistance genes, they lacked key genes such as those associated with extended-spectrum beta-
lactamase and carbapenemase enzymes. Virulence gene screening revealed that several of the
isolates might potentially be associated with an opportunistic pathogen lifestyle, but virulence
genes associated with community-acquired hypervirulence were absent.
Comparative genomics was used to compare these Alberta sewage isolates to the publicly
available genomes of clinical, environmental, and wastewater isolates. The species and multi-
locus sequence type (MLST) of the sewage isolates were identified using their assembled
genomes. The goal of this analysis was to identify phylogenetic relationships to clinical strains
and antimicrobial resistance genes (ARGs), along with a comprehensive analysis of virulence
gene carriage in the chlorine-resistant sewage isolates. The sewage KpSC isolates in this study
included Klebsiella pneumoniae, Klebsiella quasipneumoniae, and Klebsiella variicola
belonging to 15 different sequence types. Of the 21 sewage isolates, eight resolved into a clade
with one or more exclusively clinical RefSeq genomes. Single-nucleotide polymorphism (SNP)
analysis showed that six sewage isolates differed from at least one of those clinical isolates by
<80 SNPs. The virulence gene profiles of the sewage and clinical isolates were also remarkably
similar. This suggests a close genomic and phylogenetic relationship between some of the
chlorine-resistant sewage isolates and clinically relevant pathogenic strains. However, key
differences were noted in the resistomes of the sewage isolates, as they lacked many clinically
relevant ARGs such as extended-spectrum beta-lactamase and carbapenemase enzymes, and
which were frequently detected in the closely related clinical KpSC genomes.
The findings of this thesis represented an initial exploration of water treatment resistance,
pathogenicity, and AMR in chlorine-resistant sewage isolates of the KpSC. The chlorine and
heat resistance found among these isolates may be explained by a combination of the tLST, the
hypermucoviscous phenotype, and other alternative mechanisms. Many of the characterized
isolates could potentially be pathogenic, although their susceptibility to antimicrobials and the
absence of key antimicrobial resistance genes (ARGs) from their genomes suggest that they are
unlikely to represent a substantial AMR threat. Future research should include more in-depth
bioinformatic analysis of the isolates studied in the present thesis, as well as continued
monitoring of sewage bacteria, including KpSC, to evaluate evolutionary trends over time
Conformal Metasurfaces as Waveguide Liners and Antenna Radomes: Analysis, Design and Implementation
No full textThis work presents the analysis and design of metasurfaces that are built to conform to a non-planar geometry. The proposed conformal metasurfaces are investigated with a particular focus on two overarching applications: as liners in circular waveguides and as a radome that implements beamshaping. In the circular waveguide liner role, the metasurface takes the form of a coaxial cylinder that is contained within a perfect electric conductor (PEC) running along its length. An analytical construction of the metasurface as a homogenized surface admittance facilitates the implementation of a theoretical formulation that allows for the prediction of the dispersion properties of a metasurface-lined waveguide. This theoretical formulation aids in the design of the metasurface liner, providing insight into what surface parameters are required to be implemented to target a given cutoff, as well as surface parameters that would implement interesting propagation properties such as chirality. Simulation results of practical metasurface geometries show that significantly reduced cutoff frequencies and chiral behavior can be achieved with single-layer metasurface structures. Experimental results further verified the reduced cutoff propagation properties and chirality that can be implemented in metasurface-lined circular waveguides. Initial investigations of these metasurface liners in global positioning system (GPS) antennas and magnetic resonance imaging (MRI) applications have been conducted, showing some promising results. However, further work must be done to make these metasurface structures practical for these applications. As for the role of metasurfaces as radomes, the proposed metasurface is inserted into an existing radome structure, following the interior wall of the radome to maximize the utilization of the space available to the metasurface for radiation pattern shaping. Once again, an analytical construction of the metasurface is used to represent the metasurface with equivalent surface impedance parameters, which facilitates the implementation of a theoretical formulation that allows for the prediction of the radiation pattern produced by an antenna array and the proposed metasurface. This analytical framework enables the rapid calculation of different metasurface configurations, which allows for the optimization of these metasurface parameters to determine an appropriate set of surface parameters along the metasurface to implement a desired radiation pattern. Two types of metasurfaces are investigated for radiation pattern control: a bianisotropic surface and a single metallic layer surface, which only implements an electric response. Through the course of research, it was found that the single metallic layer surface was more practical, both in analysis and implementation. Therefore, this surface was investigated further, leading to a complete design procedure that not only targets a set of desired radiation pattern criteria but also attempts to preserve matching between that antenna array and the input port. Analytical results for the single metallic layer metasurface showed that significant radiation pattern transformations can be implemented. Simulation and experiments of the metasurface structure verify the analytical results, showing reasonable agreement. The experiment demonstrates a practical method in which these metasurface structures can be inserted into an existing antenna radome through the use of 3D printed plastic support structures
Circulating Current Suppression in Parallel VSIs Using a Single-Carrier Based PWM Scheme
No full textParallel-connected power converters are gaining popularity in the industry due to their ability to handle high current ratings at low voltages. In three-phase grid-connected systems, two and three parallel-connected inverter legs per phase are utilized to enhance the system’s current capacity while improving harmonic rejection. In such systems, inductors are employed to limit circulating currents between the output
terminals of parallel inverter legs, and coupled inductors are often used to reduce the size of the magnetic components, optimizing the system’s overall performance.
An interleaved PWM technique with multiple phase-shifted carriers can be employed to control a three-paralleled inverter leg VSI system, generating a high-quality multi-level output voltage and reducing the need for output filtering. However, a notable drawback of this approach is that interleaving can introduce DC offsets in the circulating currents between the parallel converters. These DC offsets can accumulate over time and cause inductor core saturation, potentially damage semiconductor devices, distort current and voltage waveforms, and reduce system’s reliability. As a result, effective suppression of these circulating current offsets is essential using appropriate PWM schemes.
A novel PWM scheme, termed ‘Rotational Enhanced PS-PWM,’ is introduced in this thesis to effectively control circulating currents and flux in Coupled Inductors of three inverter legs in one phase simultaneously during carrier phase transitions. To minimize implementation complexity, the scheme is implemented using a single carrier, manipulating reference signals to phase-shift the PWM switching patterns and thereby configuring the phase-shifted carriers. The switching patterns are adjusted to control the phase of the circulating currents, suppressing the offsets within half a carrier cycle while ensuring high-quality line voltage output and glitch-free current waveforms.
The feasibility of the proposed scheme is demonstrated through simulations under different operating conditions. Further validation is conducted through experiments on a 5 kW hardware setup of a three-phase, three-paralleled inverter leg VSI with 3-limb cross-coupled inductors connected to a resistive load via a filter inductor. An FPGA-based laboratory scale experimental prototype platform is designed and implemented for PWM control of the inverter. Carrier and adapter boards are developed as interface boards between the controller and the inverter. The platform’s ability to handle custom PWM schemes and synchronize real-time data exchange confirms its potential for future experimental validation in power converters. Experimental results under varying conditions validate the proposed scheme’s capacity to handle rapid transient step changes, making it suitable for applications requiring high fundamental frequencies. Results are provided for both open-loop and closed-loop control, confirming its applicability and robustness in real-world scenarios
Insight into government, November 7, 2025
No full textAlberta's independent newsletter on government & politics
Thrombin generation in ischemic stroke
No full textStroke is a leading cause of adult disability and mortality worldwide. Thrombosis is
central to cerebral vascular occlusion that causes stroke therefore targeting coagulation remains
at the centre of stroke treatment and prevention. Thrombin is a central protease in the coagulation
cascade, therefore understanding the mechanisms that contribute to its generation is essential to
development of novel biomarkers and anticoagulant therapeutics. This thesis examines several
aspects of the immune system including peripheral blood cell gene expression, monocytes, and
platelets to better understand thrombin generation in ischemic stroke.
In the first part of this work, the relationship of blood cell gene expression to thrombin
generation capacity in patients with ischemic stroke is examined. Proinflammatory and
prothrombotic genes associated with thrombin generation capacity were identified such as genes
involved in nuclear factor κB (NF-κB), interleukin (IL)-6, and thrombin signaling, as well as
coagulation factor activation and inhibition. A linear discriminant analysis prediction model was
developed to distinguish patients with low and high thrombin generation capacity in a validation
cohort of 112 patients. This study demonstrates a proinflammatory shift in gene expression
associated with thrombin generation capacity in patients with ischemic stroke.
Sex differences in blood cell gene expression associated with thrombin generation
capacity were also evaluated. While females and males had overall similar capacity to generate
thrombin, differences in gene expression exist. In females, high thrombin generation capacity
was associated with increased expression of genes that promote thrombosis as well as genes
associated with platelet activation, while in males, high thrombin generation capacity was
associated with a decrease in genes involved in endogenous anticoagulation. These findings\nreflect regulatory differences in thrombosis between females and males and offer value in
guiding future studies aiming to develop sex-specific treatments
In the second part of this work, contributions of monocytes and platelets to thrombin
generation and clot properties is examined. Monocyte tissue factor (TF) expression and activity
was characterized using flow cytometry and thrombin generation assay (TGA), respectively. A
clot formation and lysis assay was also used to assess final clot properties and lysis. Treatment
of monocytes with LPS was associated with an increase in TF expression. This was also
accompanied by an increase in TF activity represented by an increase in peak thrombin, and
endogenous thrombin potential (ETP) and a reduction of lag time and time to peak thrombin.
Monocyte TF was associated with formation of a denser clot that has significantly prolonged
lysis time compared to untreated monocytes. Monocytes also can also bind platelets, forming
monocyte-platelet aggregates (MPAs). These MPAs have been implicated in cardiovascular
disease and risk. Here, isolated activated human platelets and monocytes were used to assess
MPAs by flow cytometry and TGA. MPAs were associated with an increase in P-selectin, but not
TF expression. The observed MPAs also had higher capacity to generate thrombin represented by
increased peak thrombin. Both MPA levels and MPA thrombin generation capacity were
significantly reduced with anti-CD62P treatment but remained unimpacted by aspirin. Lastly,
increased levels of soluble P-selectin in patients with ischemic stroke compared to control
participants, as well as in patients with stroke that had worse 90-day outcome were identified.
In the final part of this thesis, the relationship of thrombin generation capacity to 90-day
outcome in patients with ischemic stroke treated with recombinant tissue plasminogen activator
(r-tPA) was evaluated. Thrombin generation capacity determined by TGA was significantly
increased in patients with worse 90-day outcome compared to patients with good 90-day\noutcome and this association persisted after adjusting for covariates. Increasing concentration of
thrombin were associated with formation of a denser clot and prolongation of clot lysis time by
tPA. Plasma proteins measured with a multiplex fluorescent bead assay in these patients were
also assessed and proteins associated with thrombin generation capacity include interleukin (IL)-
6, IL-8, and fibrinogen, and ⍺-2 Macroglobulin (⍺2M).
Taken together this thesis builds our understanding of thrombin generation in ischemic
stroke, demonstrating its variability in patients, as well as its association with blood cell gene
expression, and stroke outcome. Influences on thrombin generation from monocytes and platelets
are also examined and altogether these findings may represent future avenues for stroke
biomarkers and therapeutics
Contributions of the Type Six Secretion System to Vibrio cholerae's pathogenesis and disease severity
No full textVibrio cholerae is the causative agent of cholera, a diarrheal disease that affects around 4 million people and kills 100,000 annually. V. cholerae possesses a Type Six Secretion System (T6SS) that delivers detrimental effector proteins to neighbouring cells, aiding with the elimination of intestinal commensal bacteria. T6SS-dependent killing of microbial competitors facilitates V. cholerae host colonization, contributing to V. cholerae virulence. However, the full extent of the contributions of V. cholerae’s T6SS to pathogenesis and disease severity remains unclear.
To determine how the T6SS contributes to multiple aspects of V. cholerae pathogenesis and disease severity, I used a zebrafish model and established a time course of an acute V. cholerae infection followed by a recovery period, simulating how natural V. cholerae infections occur. The T6SS provides a competitive advantage in host colonization and allows V. cholerae to persist within the adult zebrafish intestine. Upon V. cholerae infection, the T6SS promotes intestinal epithelial damage and shifts the intestinal bacterial composition. Also, transplantation of this shifted bacteria population into axenic zebrafish larvae resulted in no protection from colonization after a subsequent V. cholerae infection. Notably, transcriptomics illustrated how a V. cholerae infection results in downregulation of immune related genes that may indicate a decreased response from the host. Lastly, V. cholerae re-infection demonstrated how prior exposure to the T6SS allowed V. cholerae to persist within the adult zebrafish intestine. Interestingly, transcriptomic analysis revealed an upregulation of immune related genes in secondary V. cholerae infections. The inverse relationship in the expression of immune related genes may indicate bacterial recognition from the host and the ability to mount a better response