title: Inherently Safer Design Protocol for Process Hazard Analysis

subject:
process hazard analysis
bow tie diagram
inherently safer design

abstract:
Inherently safer design (ISD) is a component of industrial safety that focusses on the elimination and reduction of hazards using four principles – minimization, substitution, moderation and simplification. Process hazard analysis (PHA) has been identified as an opportunity to explicitly consider ISD and enhance the implementation of ISD within process safety management (PSM) frameworks. The PHA technique of interest for this research was the bow tie methodology.

The objective of this research was to develop a protocol to identify ISD-based barriers in bow tie diagrams. Example-based guidance was used to identify potential ISD opportunities. The protocol was validated using case studies from the US Chemical Safety Board (CSB) and Contra Costa County Health Services. Protocol validation demonstrated the ability of the protocol to identify potential ISD barriers. Recommended future work is further protocol validation in a predictive manner within an industrial organization.


title: Exploring the Phylogenetic Diversity of Phagotrophic Euglenids

contributor:
Department of Biology
Doctor of Philosophy
Ramon Massana
Sophia Stone
Andrew Roger
Claudio Slamovits
Julie LaRoche
Alastair Simpson
Not Applicable
Yes
Not Applicable

subject:
protists
phylogenetics
euglenids
evolutionary microbiology
microscopy

abstract: Euglenids are a widespread, complex group of flagellated, single-celled eukaryotes. The majority of described species are phototrophic forms, yet a large portion of the phylogenetic diversity is composed of phagotrophs, from which phototrophs arose through secondary endosymbiosis. To understand euglenid evolution it is necessary to understand phylogenetic relationships among phagotrophic euglenids. Yet despite their diversity and evolutionary relevance, phagotrophs are underrepresented in molecular sequence data that is crucial in reconstructing evolutionary relationships. Unfortunately they are difficult to culture, which complicates molecular data collection for most species, as standard methods of nucleic acid extraction cannot be used. I used a culture-independent single-cell approach to increase sampling of the SSU-rDNA gene for phagotrophs almost five-fold (now 141 sequences). Phylogenetic trees show that ploeotids, an assemblage of rigid phagotrophs, make up much of the basal phylogenetic diversity. Several morphotypes that were previously lumped together into a single genus Ploeotia are not monophyletic and belong to multiple separate genera, including Olkasia nov. gen. Two species of ‘spirocute’ Anisonema proved to be ploeotids and were transferred to new genera Hemiolia and Liburna. More previously unsampled phagotrophs belong within Spirocuta (which includes phototrophs and osmostrophs), and phylogenetic analyses revealed several morphologically-defined genera are likely not monophyletic. To better resolve the tree of euglenids, I generated 24 single-cell transcriptomes to provide data for a 20-gene phylogenetic analysis. This divided Spirocuta into phototrophs, a robust ‘Anisonemids plus’, and a weakly supported ‘Peranemids’ clade. Ploeotids are paraphyletic, with Olkasia robustly inferred as sister to Spirocuta, whereas petalomonads are placed basal to all other euglenids with high support. The multigene analyses suggest that symbiontids are not euglenids, but may be more closely related to diplonemids and kinetoplastids. Hemimastigophora are a group of enigmatic multiflagellated cells that have long evaded molecular sequencing, and were inferred at one point to be related to euglenids based on electron-microscopy data. A single-cell approach generated transcriptomes of group members Spironema and Hemimastix, enabling them to be included in eukaryote-wide phylogenomic analyses. Remarkably, Hemimastigophora do not fall into any recognised supergroup of eukaryotes, but form their own independent group that branches outside both Diaphoretickes and Amorphea.


title: Aciniform Spider Silk Proteins: Investigating Solution-State Assembly and the Potential of Silk Nanoparticles as a Drug Delivery Vehicle

contributor: Department of Biochemistry & Molecular Biology with Neuroscience

subject:
biochemistry
proteins
silk
nanoparticles
biomaterials
drug delivery

abstract: Spider and silkworm silks form a wide variety of biomaterials with desirable mechanical properties and biocompatibility.  The process of fibrillogenesis from silk solution is not fully understood, but may be dependent on micellar assemblies formed in the gland.  In this study the micelle formation and surface adsorption of a recombinant aciniform repeat unit (W1) were investigated, as this may give clues to the fibrillogenic pathway.  It was found that micelle-like assemblies formed by W1 are very low in yield, however the protein self-assembles at the liquid-air interface.  Aciniform proteins with multiple repeats showed visco-elastic properties at the surface layer while W1 did not.  The alignment and conformational changes of aciniform proteins at the liquid-air interface may be relatable to those which occur during fibrillogenesis.  Disruption to helix 5 of the W1 protein may be involved in early conformational transitions during the process of fibrillogenesis.  The R36W residue of a W1 variant, which is on the protein surface beneath helix-5, was found to make the variant less stable than the wild-type.  This may be due to disruption to helix 5 caused by the substitution, which may expose a hydrophobic surface that encourages interprotein interactions.  Silkworm and dragline spider silk are well established as potential drug delivery vehicles, however aciniform silks have not yet been investigated for that purpose.  Nanoparticles of W1 were formed by a desolvation process and characterised in terms of size and conformation, yielding a novel biomaterial for aciniform silk.  Aciniform nanoparticles may have different drug-compatibilities and desirable uptake and release properties compared to other silk nanoparticles, though this remains to be investigated.


title: OPTICAL COHERENCE TOMOGRAPHY FOR CLINICAL OTOLOGY

contributor:
Department of Biomedical Engineering
Doctor of Philosophy
Dr. Brian Applegate
Dr. Jeremy Brown
Dr. Laurent Kreplak
Dr. Jeremy Brown
Dr. David Morris
Dr. Robert Adamson
Received
Yes
Yes

subject:
Optical Coherence Tomography
Otology
Vibrometry
Medical Imaging

abstract: The potential utility of OCT for diagnostics in otology has been acknowledged for nearly two decades, but studies have focused largely on application to understanding basic physiology where animals and cadavers can be used, or where only the tympanic membrane is of interest.  We performed benchtop experiments in human cadavers with a custom OCT system to understand the design challenges and practicalities of moving towards its application to live, awake subjects with real-world pathologies of the middle ear. We quantify the deleterious effects of imaging the middle ear volume through the intact tympanic membrane, and demonstrate new clinical applications of imaging erosions of the osscicles and post-operative ossicular prosthesis tracking. New swept-laser technology enabled fast and phase-stable OCT measurements that capture both structure and displacement simultaneously in a technique called OCT-DV, the functionality of which was integrated into a mounted microscope suitable for use in live humans. The system allowed viewing of the full lateral and axial extents of the tympanic membrane and middle ear cavity, and was used to perform the first in vivo OCT-DV measurements in live humans, notably at the incus through the intact tympanic membrane. Special effort was made to make the system provide immediate, real-time results to the operator for maximum usability, and relied on GPU acceleration of OCT-DV. The same system was applied to cohorts of individuals with normal hearing (N=42 ears), and of individuals clinically diagnosed with otosclerotic stapes fixation (N=13 ears). We show that the OCT-DV implementation in our instrument was able to discriminate between the two samples with particularly good sensitivity (1.00) and specificity (0.98) using absolute peak-to-peak displacement measured at the incus at a stimulus frequency of 500Hz, and that there exist some technical improvements that could better separate the two groups. Specifically, addressing the practical displacement sensitivity penalty incurred in imaging live, awake subjects. We also detail progress on continued development of the system, and present several unique case studies where OCT and OCT-DV can offer additional insight into the state of the middle ear.


title: THE PLASMINOGEN RECEPTOR S100A10:  STRUCTURE AND FUNCTION STUDIES

contributor:
Department of Pathology
Doctor of Philosophy
Dr Michael Boffa
Dr Wenda Greer
Dr Alexander Easton
Dr Brent Johnston
Dr Rob Liwski
Dr David Waisman
Received
Not Applicable
Yes

subject: Fibrinolysis

abstract:
The critical role of the fibrinolytic system is the maintenance of vascular patency. Dysregulation ultimately leads to death; an inappropriate activation that causes excessive bleeding, or an inability to clear blood clots, leading to thrombosis, ischemia and death. Plasminogen receptors (PgR) are found on the surface of many cells, notably endothelial cells and lymphocytes. PgR bind plasminogen to the cell surface, promote directed proteolytic plasmin activity and protect bound plasmin from inhibition. This process is important for vessel patency, wound healing and inflammation. In addition to homeo- and hemostatic roles, PgR can be hi-jacked by cancerous cells for more nefarious roles. Oncogenic cells utilize focussed proteolytic activity of cell-bound plasmin to escape from primary tumours. Understanding how the PgR, plasminogen and activators interact may lead to targeted therapies for clot dissolution or cancer, among other diseases. Plasminogen contains kringle domains that bind to C-terminal lysine residues of fibrin and PgR. Studies were undertaken to explore how alterations in the C-terminal region of S100A10, a PgR, impact its ability to accelerate plasmin generation. S100A10 has 4 lysine residues in its C-terminal region, two at the C-terminus. Deletion of both C-terminal lysine residues results in the loss of up to 90% of the rate of plasmin generation. Substitution of the C-terminal lysines with isoleucine resulted in minimal activity loss. This led to the possibility that another lysine residue is a secondary binding site for kringles. Mutating internal sequence lysine residues to arginine resulted in little change in plasmin generation ability, however, changing a lysine to arginine at position 56 in addition to the substitution of C-terminal lysines to isoleucine resulted in a significant loss of plasmin generating ability.
Additionally, a study was initiated to explore a potential role of S100A10 in the demyelination of multiple sclerosis and other diseases whose hallmark is myelin loss. S100A10-null mice, 7 days post-demyelination event (lysophosphatidylcholine injection), had significantly larger lesion volumes than wild type mice injected concurrently. S100A10-null lesions had lower concentrations of microglia/macrophages within the borders of the lesion, indicating that the larger lesion possibly stemmed from a reduced ability to phagocytose degraded myelin.


title: Narratives of Nature and Culture: The Cultural Ecology of Elisabeth Mann Borgese

contributor:
Interdisciplinary PhD Programme
Doctor of Philosophy
Dr. Heather I. Sullivan
Dr. Lynne Robinson
Dr. Michael House
Dr. David Black
Dr. Aldo Chircop
Dr. Thomas Curran
Not Applicable
Not Applicable
Not Applicable

subject:
Borgese, Elisabeth Mann
Interdisciplinary Studies
Cultural Ecology
Narrativity
Anthropocene

abstract:
Elisabeth Mann Borgese, born in Munich in 1918, the youngest daughter of German novelist, Thomas Mann, and Katia Pringsheim, made it her moral duty to consider the future of humanity. For her, the ocean, with its densely interconnected structures, acts as a natural model for paradigmatic changes to cultural systems. Arguably, this was only the beginning of a wide-ranging utopian plan envisioning a dynamic, equitable, and ecological world order comprised of a world government and functional ‘world communities’ based on the common heritage of mankind concept.
The works and biography of Mann Borgese are viewed mostly through the lens of the international law of the sea and as another chapter of the Mann family history. As a result, the interconnections between her thematically diverse writings are often ignored. Using an interdisciplinary narrative approach, this thesis examines Mann Borgese’s nonfiction and fiction work as well as archival materials originating from the late 1950s to the early 2000s. More specifically, Mann Borgese’s work is situated here within the contexts of cultural ecology or Kulturökologie and is explained against the backdrop of politico-historical events. A broader understanding of narrative both as a concept and as a tool for interdisciplinary scholarship in the Anthropocene serves as methodological background.
A close reading of Mann Borgese’s works first analyzes Mann Borgese’s ‘philosophy of continuity’, highlighting the interconnectedness between the individual, society, and nature based on evolutionary and complexity theories. Secondly, it reveals that Mann Borgese’s philosophy of continuity constitutes the link between her work, both fiction and nonfiction, which is articulated through leitmotifs, metaphors as well as intertextual and thematic interrelations. Thirdly, it showcases that Mann Borgese’s emphasis on continuity and cooperation between agents of nature and culture constitutes the basis of her extended understanding of humanism and the common heritage of mankind concept. Lastly, it illustrates the ideological setting of her cultural ecology in which society and its cultural subsystems of law, economy, science and education are organized in such ways to be able to deal with complex global problems ecologically and for the benefit of all humanity.


title: The Autonomous Landing of Rotary-Wing UAVs on Underway Ships in a Sea State

contributor:
Department of Mechanical Engineering
Doctor of Philosophy
Siu O'Young
Dominic Groulx
Jason Gu
Dominic Groulx
Clifton Johnston
Mae Seto
Not Applicable
Not Applicable
Yes

abstract:
There is a desire among researchers, governments, corporations and the public to learn more about our environment. To learn how it is changing, how it can be more efficiently used, interacted with, protected and understood. Some of these environments are also some of the harshest, meaning any tool that can help mitigate risks, decrease costs and maximize opportunities should be considered, such as unmanned aerial vehicles (UAV). In order to fully unlock the potential of these tools some infrastructure is lacking, mainly their recovery at sea. Current technologies focus on vision-based systems and very few end-to-end autonomous ship based algorithms have been demonstrated. Most current technologies also require very calm sea states. Here, a novel autonomous landing technique is presented.

The algorithm uses acoustic positioning to allow for landings in a wider breadth of conditions and reduces the reliance on specially designed landing targets. It also features a potential fields path planner to adapt for ship motion and provide some obstacle avoidance and natural biasing away from the heaving deck. The autonomy uses a sea state predictor to compensate for harsher sea conditions and ship motion, allowing the UAV to look for appropriate landing windows in higher sea states.

Autonomous landings are demonstrated in simulation and in a lab setting for sea conditions up to, and including, sea state 5. The ship motions in these sea states are defined using real sea trials data from the decommissioned Annapolis-class destroyer HMCS Nipigon.


title: OPTIMIZATION OF ELECTRODE SYSTEM FOR ELECTROHYDRODYNAMIC (EHD) DRYER

contributor:
Faculty of Agriculture
Master of Science
Gordon Price
Tadeusz Kudra
Thijs Defraeye
Peter Havard
Alex Martynenko
Not Applicable
Not Applicable
Yes

subject:
Electrohydrodynamic
multiple needle discharge electrode
mesh collecting electrode
spacing
gap

abstract: Electrohydrodynamic (EHD) drying is a non-thermal dewatering technology, based on the phenomenon of high-voltage corona discharge in the gaseous medium. It is offering high product quality and less energy consumption compared to commonly used thermal drying. Since EHD drying was not commercialized yet, this research was focused on the optimization of discharge and collecting electrodes for industrial application of this drying technology. Three types of needles in discharge electrodes and mesh-type collecting electrodes with different open area, wire diameter, and grounded wires percentage have been studied. Discharge electrode fabricated with sharp pins or construction nails was found to be the most suitable to use in EHD dryers. Mesh collecting electrode significantly enhanced drying rate compared to a solid plate and it is recommended to use in the large scale EHD dryers. The results of this research are critical for further industrial upscaling of the EHD drying technology.


title: CONTRIBUTION OF THE VOLTAGE-GATED SODIUM CHANNEL NAV1.6 AND TOLL LIKE RECEPTOR 2 IN THE PATHOPHYSIOLOGY OF EAE

contributor:
Department of Biology
Doctor of Philosophy
Dr. Shalina Ousman
Dr. Sophia Stone
Dr. William Baldridge
Dr. Francois Tremblay
Dr. Patrice Côté
Dr. Jean Marshall
Received
Yes
No

subject:
Neurosciences.
Immunology
Multiple sclerosis
Encephalomyelitis

abstract: Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, and neurodegenerative disorder of the central nervous system (CNS) with the highest worldwide prevalence existing in Canada and affecting over 3000 Nova Scotians. MS is characterized by the autoimmune-mediated destruction of myelin and axons in the CNS and has been linked to inflammatory processes that activate the immune system. The most recent understanding of the mechanisms associated with the development of MS suggests that the inflammatory processes in the early stages of the disease trigger a cascade of events including microglial activation, the release of reactive mediators, and mitochondria damage, which subsequently leads to axonal damage. Axonal degeneration, one of the hallmarks of the disease and a non-reversible process, leads to several neurological disabilities including visual impairment and vision loss. However, the mechanisms underlying axonal degeneration remain unclear. This thesis sought to characterize the impact of two key regulatory molecules: the voltage-gated sodium channel Nav1.6 and the Toll-like receptor 2, a component of the innate immune system, in the pathogenesis of EAE. To this end, I used experimental autoimmune encephalomyelitis (EAE), a rodent model that recapitulates key aspects of the human disease. I investigated the role of voltage-gated sodium channels (especially Nav1.6), which have previously been linked to axonal degeneration and loss (Chapter 2) by gene targeting in the retina and optic nerve. We extended these studies to determine the impact of the reduction of Nav1.6 in mice heterozygous for a null-allele of Scn8a. (Chapter 3).  This in vivo study is the first to link a reduction of Nav1.6 in EAE to immune profile changes, such as a reduction of inflammation marked by decreased IL-6 in the plasma and myeloid cell infiltration in the optic nerve. Analysis of murine bone-marrow-derived mast cell (BMMCs) cultured in vitro, suggest a potential role of Nav1.6 in regulating the inflammatory process during EAE and LPS challenge. Additionally, I investigated the impact of TLR2 in brain inflammation and optic nerve axonal damage (Chapter 4).  I found that the absence of TLR2 was associated with reduced inflammation in the periphery and within the CNS, including in blood, spleen, and brain, which is marked by decreased myeloid cells, such as Gr-1+/CD11b+ cells, chemokines in the plasma, and pro-inflammatory cytokines in the brain. The present study provides novel information by highlighting the role of TLR2 and Nav1.6 in EAE. This knowledge expands our understanding and ultimately promotes further investigation to target these molecules and unmask the mystery of their roles in MS.


title: Author and Language Profiling of Short Texts

contributor:
Faculty of Computer Science
Doctor of Philosophy
Dr. Robert Mercer
Dr. Michael McAllister
Dr. Evangelos Milios
Dr. Stan Matwin
Dr. Vlado Keselj
Not Applicable
Not Applicable
Not Applicable

subject:
Language Identification (LID)
Social Media Bot Detection
Topic Modelling on Short Texts
Social Media Mining

abstract: Over the past couple of decades, the advancement and growth of digital information and communication technologies have resulted in information explosion and these technologies are profoundly changing all aspects of modern society. The popularization of the Internet and mobile technologies fueled the rise of social media, providing technological platforms for information spreading, content generation, and interactive communication, which has been contributing to the global data growth. Additionally, social media have become one of the main outlets for obtaining information about latest news, people, businesses, services, etc. The research on it has gained traction having in mind the growing interest in the applications and related technical and social science challenges and opportunities. One of the big challenges of the widespread online textual data is the structure and size. Structurally, it is not in proper grammatical form, has slang, emoticons, improper sentences, which is the standard way we communicate daily. Size-wise, the text is usually very short. However, this is not only the case with the online data; medical notes, open-ended survey questions, various old-school maintenance reports are just some of the examples. We particularly focus on the problem of author profiling on short texts in three different domains. Automatic author profiling is a set of methods to determine an author's (or group of authors') gender, age, native language, personality type and similar, which can be useful in different application contexts such as forensics, security, marketing, product personalisation, socio-demographic analyses and so on. In the first task, we explore fine-grained language dialect/variety identification and propose a new feature weighting scheme. In the second task, we work on bot detection on social media and propose a simple, but efficient method based on statistical diversity measures. In the third task, we present some interesting findings on topic modelling in relation to author on open-ended survey questions from the Canadian Longitudinal Study on Aging (CLSA).


title: Design of initial shotcrete lining for a mine shaft using two-dimensional finite and hybrid finite-discrete element methods

contributor:
Department of Civil Engineering
Master of Applied Science
Hany El Naggar
Hany El Naggar
Andrew Corkum
Navid Bahrani
Not Applicable
Not Applicable
Not Applicable

subject:
shotcrete
numerical modeling
mine shaft

abstract:
Shotcrete is widely used as a temporary support element in the construction of underground mines and tunnels. It is sprayed on the excavation walls close to the face to provide a safe working condition for mine personnel and equipment until the permanent support elements are installed. Therefore, the ability of the shotcrete lining to resists falls of ground is of paramount importance. The mechanical properties of shotcrete, including strength and stiffness, change with time as the excavation advances. Shotcrete may also be subject to plastic deformation, if it is loaded beyond its maximum capacity, especially in fast advancing excavations. Conventional methods for the design of shotcrete lining, based on analytical and empirical approaches, do not consider the influence of advance rate on the time-dependent properties and deformation behavior of shotcrete.

In this research, two-dimensional finite and hybrid finite-discrete element methods are utilized to develop new methodologies for the design of initial shotcrete lining for a mine shaft by considering the excavation advance rate. These methods are also used to gain further insight into the damage evolution leading to the failure of shotcrete liner during the excavation advance. Through the analyses of the load and strain factors of safety calculated for the shotcrete liner based on the results of finite element models, the minimum shotcrete thickness is suggested for the mine shaft. From the results of the hybrid finite-discrete element model, it is concluded that the shotcrete liner cannot be used as a sole support element for the mine shaft as it fails during the excavation advance due to the shaft convergence. However, it can be used as a temporary support, although it may be damaged until the final, permanent concrete liner is installed.


title: CORPORATE SUSTAINABILITY IN MARITIME PORTS

contributor:
Interdisciplinary PhD Programme
Doctor of Philosophy
Professor Allan Tupper
Dr. Lynne Robinson
Dr. Tony Walker
Professor Gregory Magnan
Dr. Hamed Aghakhani
Dr. Michelle Adams
Received
Yes
Yes

subject:
corporate sustainability
maritime ports
corporate social responsibility
sustainable development
maritime industry

abstract:
The main objective of this doctoral dissertation is to provide a holistic and in-depth understanding of corporate sustainability in maritime ports. The study consists of two parts: the first part entails two original research articles focusing on the conceptual and theoretical foundations of corporate sustainability, and the second part entails three original research articles focusing on the application of corporate sustainability in maritime ports. The five research articles address a set of sub-objectives: 1) to develop a deep understanding of the notions of corporate sustainability and corporate social responsibility, as well as the distinctiveness, complementarities, and integration of the two fields (a critical review study); 2) to develop a deep understanding of the conceptual evolutionary path and theoretical underpinnings of corporate sustainability and corporate social responsibility (a narrative review study); 3) to develop a deep understanding of drivers influencing maritime ports’ sustainability activities, as well as actions taken by ports to attain sustainability objectives as a response to these drivers (a systematic review study); 4) to develop a deep understanding of the state of sustainability in maritime ports, focusing on the perception of port executives towards sustainability, ports’ sustainability strategies and practices, and main factors influencing future adoption and implementation of sustainability in ports (a survey-based empirical study); and 5) to develop a deep understanding of the role of multistakeholder cooperation to strengthen sustainability of maritime ports and maritime transport and logistics (a case study-based empirical study).
This dissertation contributes to the corporate sustainability literature in maritime transport and logistics, and maritime ports in particular, by providing insights about why and how corporate sustainability should be embedded in a corporate business model to help improving and sustaining the viability of corporations. It also provides suggestions for supporting and strengthening sustainability at the corporate level, as well as the industry level through multi-stakeholder cooperation.


title: Investigation of the Amyloid Properties of Winter Flounder Antifreeze Protein (AFP6) and the Application of Aqueous Curcumin in the Detection of this Protein

contributor: Department of Biochemistry & Molecular Biology

subject:
Winter Flounder
Amyloid
Curcumin
Antifreeze proteins
AFP
Pseudopleuronectes americanus
WflAFP-6
Curcumin stain

abstract: A Pseudopleuronectes americanus antifreeze protein, AFP6, has previously been shown to form amyloid upon specific interaction with an ice surface. In this work, an in situ real-time assay for amyloid formation by amyloid beta was implemented in order to evaluate potential cross-seeding of amyloid formation by synthetic AFP6. However, insufficient AFP6 amyloid was produced to continue with the assay. Through this work, AFP6 was found to be easily separated from other proteins due to its solubility in acetone. Furthermore, although AFP6 is undetectable using common positive protein stains, aqueous curcumin allowed fluorescence-based detection of AFP6. The absorbance and fluorescence spectra of curcumin are both altered in the presence of AFP6, with more marked changes following 70 °C incubation. However, the melting point and secondary structure of AFP6 determined by circular dichroism were unchanged by curcumin. Thus, single-reagent methods for purifying and detecting this unusual protein were found to be effective.


title: THE ROLE OF CORTICAL SPREADING DEPOLARIZATIONS IN TRAUMATIC BRAIN INJURY OUTCOME

contributor:
Department of Medical Neuroscience
Doctor of Philosophy
Dr. Jed A. Hartings
Dr. Ying Zhang
Dr. William Baldridge
Dr. Victor Rafuse
Dr. Alon Friedman
Received
Not Applicable
Not Applicable

subject:
Traumatic brain injury
Concussion
Spreading depolarization
Blood-brain barrier
Seizure
Neurovascular coupling

abstract:
Traumatic brain injury (TBI) is a blow to the head that disrupts normal brain function.
Concussion is a common clinical syndrome that can follow mild TBI. Concussion is associated with a variety of disabling neurological symptoms that may last for months and even years. Despite growing interest in understanding the pathophysiology of concussion, the electrophysiological events that occur during mild TBI and underlie concussion are unknown.

To investigate the electrophysiological changes underlying concussion, we recorded epidurally from rats immediately following mild TBI. We confirmed that spreading depolarizations (SDs), and not seizures, are a common event after a mild TBI, and mostly occur within the first two minutes after an impact in one or both brain hemispheres. Animals with SDs required a longer time to resume mobility. Furthermore, TBI-induced SDs have a larger amplitude compared to triggered SDs in anesthetized and unanesthetized animals.

Next, we used intravital microscopy to study the effect of triggered SDs on blood-brain barrier (BBB) integrity and neurovascular coupling. TBI-exposed animals (but not control) showed a significant increase in BBB permeability within two hours after stimulation. The cerebral blood flow response to SDs in TBI-exposed rats was similar to that recorded in controls except the late hyperemia phase, which was significantly shorter in TBI.

To study sudden death in this TBI model, we recorded the electrical activity from the cortical hemispheres and brain stem. Within two minutes of impact, we observed SDs and non-spreading depression of electrical activity in both brain hemispheres and the brain stem. Respiration gradually slowed and eventually ceased when a depression of electrical activity was longer than 2 minutes. Cardiac arrest followed respiratory arrest and occurred around 18 minutes after TBI.

In summary, depression of brain activity is a common immediate electrophysiological change following mild TBI and may underlie signs and symptoms of concussion and be associated with immediate catastrophic death. My study proposes SD as a potential diagnostic and therapeutic target in TBI.


title: EXPERIMENTAL STUDY AND DEVELOPMENT OF SUSTAINABLE SANDWICH PANELS

contributor:
Department of Civil Engineering
Master of Applied Science
Hany El Naggar
Tamunoiyala Koko
Kyle Tousignant
Pedram Sadeghian
Not Applicable
Not Applicable
Not Applicable

subject:
Plastic waste
Sustainability
Sandwich panels
Fibre reinforced polymer
Composites

abstract: The use of disposable plastic items has been increasing enormously throughout the past ten years. Despite comprising of recyclable polymers, thermoplastic waste has made international headlines as a major source of environmental pollution. For this thesis, multiple thermoplastic constituents were used to create different sets of sandwich panels that were tested and studied rigorously to determine whether a relevant structural application can arise from the current thermoplastic waste. Polyethylene Terephthalate (PET) was used in fibre form to create a new fiber reinforced polymer (FRP) composite used as the facing material for the sandwich panels. Polypropylene (PP) was used in the form of honeycomb as a core material to one set of sandwich panels. Another set of sandwich panels was made from recycled PET foam core, which was obtained from 100% post-consumer PET bottles. Mechanical properties of the sandwich structures and their different components were obtained experimentally and analytically.


title: DRYING KINETICS AND THE EFFECTS OF DRYING METHODS ON QUALITY (CBD, TERPENES AND COLOR) OF HEMP (Cannabis sativa L.) BUDS

contributor:
Faculty of Agriculture
Master of Science
Gordon Price
Nrusimha-Nath Misra
Rajasekaran Lada
Peter Havard
Alex Martynenko
Not Applicable
Not Applicable
Not Applicable

subject:
Hemp
Cannabis sativa
Drying kinetics and modelling
non-isothermal drying
Freeze drying
convective drying
desorption isotherm

abstract: The hemp industry currently relies on traditional drying methods to preserve and extract the cannabidiol (CBD), but they do not allow a high-quality product. Therefore, effects of two drying technologies, convective drying (isothermal and non-isothermal), and freeze drying on the drying time and product quality (CBD, terpenes, color) were evaluated. An increase of the drying temperatures significantly decreased the terpenes content (above 40 ºC) but, it did not effect the CBD content. The total CBD content was the highest (2.78%) under non-isothermal drying condition (40 °C changed to 70 ºC at 25% moisture content) and was the lowest (1.28%) under freeze-drying. The proposed drying regime reduced the time by 90% compared to control (32 °C) and the CBD increased compared to the fresh material. This is by far the first report to show the behavior of CBD and terpenes as influenced by various drying temperatures and technologies in hemp buds.


title: The Impact of an Outdoor Loose Parts Intervention on Nova Scotian Preschoolers’ Fundamental Movement Skills

contributor:
School of Health & Human Performance
Master of Science
Dr. Louise Humbert
Dr. Lynne Robinson
Dr. Jessie-Lee McIsaac
Dr. Lori Dithurbide
Dr. Michelle Stone
Received
No
No

subject:
Early childhood development
Loose parts
Fundamental Movement Skills
Childcare centre
Multi-methods

abstract: Introduction: Providing opportunities for children to develop fundamental movement skills (FMS) in early years settings is important for encouraging overall health and wellness. Integrating loose parts (e.g. wooden planks, buckets) into outdoor spaces could provide preschoolers with an opportunity to develop FMS as they provide greater affordances for outdoor play. Methods: The Physical Literacy in the Early Years (PLEY) project integrated loose parts into outdoor spaces at licensed childcare centres. Child demographic, anthropometric, and FMS data were measured pre- and post-intervention. Secondary data analyses were used to determine if children exposed to the loose parts intervention had improvements in FMS. Focus group discussions regarding educator’s perceptions were used to determine if educators perceived a change in the children’s FMS. Results: Although quantitative data revealed no change in FMS between groups, analysis of qualitative data revealed three themes of educators’ perceptions of the relationship between loose parts play and preschoolers’ FMS.


title: “Running a Race with Legs That Don’t Work”: Mental Illness and the Experience of Seeking Employment

contributor:
School of Health & Human Performance
Master of Arts
Dr. Jean Hughes
Dr. Lynne Robinson
Dr. Becky Spencer
Dr. Karen Gallant
Dr. Lynne Robinson
Received
No
No

subject:
Mental Illness
Employment
Health Promotion

abstract: Individuals with mental illness face higher than average rates of unemployment and unemployment is associated with adverse effects. Job seeking can be difficult for individuals with mental illness as they often face stigma and other barriers. The aim of this study was to understand the experience of job seeking for individuals with mental illness. This thesis used a phenomenological methodology to explore this experience. Eleven individuals with mental illness were recruited to participate in interviews about their experiences of seeking employment. Themes included barriers to seeking employment, negative experiences associated with job seeking, the issue of disclosure, the importance of work and supports. Many of the barriers identified in this study have been identified before which leads to the question of why they continue to persist. Despite facing many barriers, individuals with mental illness want to find work. Work may even hold special meaning for individuals with mental illness.


title: “Don’t Throw Glitter on our Carpet”: Cultivating Queer Safe Space(s) in Halifax

contributor: Department of Sociology & Social Anthropology

subject:
2SLGBTQ+
queer
safe space(s)
Halifax

abstract: This project examines 2SLGBTQ+ safe spaces in Halifax to understand the experiences people have in these spaces and the cultivation work involved in maintaining them. Informed by queer and intersectional theories, the project asks: How do queer safe spaces in Halifax operate? Why? What successes and challenges do they face in their day-to-day maintenance? I interviewed individuals who operate and use queer spaces in Halifax to focus on the relational work necessary for maintaining them and use literature to situate the analysis in the city’s particular social and political context. Participants’ narratives demonstrate that: queer safe spaces are cultivated (and re-cultivated) through an ongoing and relational process; intentionality is integral to achieving goals; active transgression of heteronormativity through continued acts of ‘queering’ space is vital; and cultivating safe space is a complex process and cannot be understood with a singular, static concept of ‘safety.’


title: The Role of PRP4K as a Tumor Suppressor in Lewis Lung Carcinoma Cells

contributor:
Department of Pathology
Master of Science
Dr. Leigha Rock
Dr. Paola Marcato
Dr. Jeanette Boudreau
Dr. Jim Fawcett
Dr. Karen Bedard
Dr. Graham Dellaire
Received
Not Applicable
Not Applicable

subject:
Lung Cancer
PRP4K
Retinoic Acid
Hyaluronic Acid
EMT

abstract: Although originally identified as a splicing kinase, recent data indicates that pre-mRNA processing factor kinase 4 (PRP4K) may promote metastasis by a partial epithelial-to mesenchymal transition (EMT) phenotype. Thus, the objective of this project was to determine the effects of PRP4K loss on lung cancer progression and metastasis in vivo. In this thesis, I showed that knockdown (KD) of PRP4K results in a stem-like phenotype in lung adenocarcinoma cells both in vitro and in vivo. I also found that PRP4K KD resulted in a partial EMT phenotype and resulted in decreased sensitivity to the cancer stem cell targeting compound retinoic acid. I further found that PRP4K KD may induce its phenotype by modulating hyaluronic acid synthesis in these cells. Taken together, these data support the hypothesis that PRP4K is acting a tumor suppressor in lung cancer cells both in vitro as well as in vivo.


title: IDENTIFYING SEASONAL ENVIRONMENTAL TRIGGER EVENTS AND THEIR INFLUENCE ON SOIL MICROBIAL RESPIRATION AND GREENHOUSE GAS EMISSIONS IN A NOVA SCOTIA AGRICULTURAL SOIL

contributor:
Faculty of Agriculture
Master of Science
Dr. Gordon Price
Dr. Peter Havard
Dr. Gordon Price
Dr. David Burton
Not Applicable
Not Applicable
Not Applicable

subject:
nitrous oxide
nitrification
denitrification
trigger event
site preference

abstract: N2O is released from agricultural soils as a result of nitrification and denitrification. These microbial processes are affected by environmental conditions. This study developed a method of predicting trigger environmental events that would induce a response in soil respiration and examined that response under natural field conditions, considering the influence of N-Viro® alkaline biosolid amendment. Additionally, the utility of 15N site preference and the Picarro® Cavity Ring-Down Spectrometer to distinguish the source of N2O (nitrification or denitrification) from surface flux samples obtained on 15N labelled-NH4NO3 sites was investigated. It was confirmed that trigger events influence the magnitude of soil respiration and N2O emissions from agricultural soils with rewetting events dominating the magnitude of N2O flux. Indicators of nitrification increased with increasing biosolid amendment rate and NO3 accumulation was greater at deeper soil depths. The CRDS provided evidence that nitrification was the dominant source of N2O, based on site preference.


title: Combustion behaviour of multicomponent pool fires

contributor: Department of Process Engineering and Applied Science

subject:
Pool fire
Multicomponent fuel
Fire dynamics
Fire modelling
Burning rate
Flame height
Flame temperature

abstract: This work examined combustion behaviour in multicomponent pool fires through experimentation and application of empirical, global energy balance, and computational fluid dynamics (CFD) modelling approaches. Transient pool fire experiments were conducted to measure the rate of distillation in ethanol-water mixtures. The pool composition over time was predicted adequately by a batch distillation model. Steady-state pool fire experiments were conducted to evaluate the effects of mixture ratios on maximum burning rate, flame height, and flame temperature in ethanol-water, ethanol-isopropanol, and ethanol-hexane mixtures. Combustion behaviour in these fires was strongly dependent on the vapour phase composition of the fuel. Standard correlations for estimating flame heights and temperatures showed good agreement with the experiments. The open-source CFD package Fire Dynamics Simulator (FDS) was modified to enable pyrolysis modelling for multicomponent fuels. With the new modifications, FDS was able to reproduce combustion behaviours observed in transient ethanol-heptane pool fire experiments conducted by other researchers.


title: Revitalizing an Urban Homeless Community in Hong Kong

contributor:
Faculty of Architecture
Master of Architecture
Cristina Verissimo
Steve Parcell
Eric Stotts
Brian Lilley
Not Applicable
Not Applicable
Not Applicable

subject:
Homeless
Social circular economy
Bamboo community

abstract: This thesis has investigated housing the homeless population in Hong Kong by using bamboo material. With the introduction of a bamboo forest as a material source, it in turn usefully provides accommodation and infrastructure for the existing under-bridge homeless community.

abstract:
In Hong Kong ‘Unemployed’ and ‘Homeless’ are terms that are often used to refer to people who are marginalized from society, either because of high property prices and expensive rent, or government policies that are ineffective. Most of the “marginal” group are living outside. People avoid them, and the government tries to isolate them, so that they do not have much chance to re-integrate with society.
My thesis is based on the social circular economic theory and explores creating housing and community for the homeless population by utilizing an abundant local material: bamboo. The introduction of a bamboo forest in turn provides an economic infrastructure for community; while assisted design and build activities provide this “marginal” group an opportunity to participate in building their society.


title: Mechanochemically alloyed Si-TM (TM=Fe, Cr) and Quantitative Composition Determination by Mössbauer Spectroscopy

contributor:
Department of Chemistry
Master of Science
Dr. Mark Stradiotto
Dr. Mita Dasog
Dr. Michael Freund
Dr. Mark Obrovac
Not Applicable
Not Applicable
Not Applicable

subject:
Lithium-ion Battery
Mechanochemistry
Si Alloy

abstract:
Si as a negative electrode material in Li-on batteries has garnered considerable research interest because of its volumetric capacity, thermal stability, and relative low cost. However, because Si does not store Li via an intercalation mechanism Li storage in Si results in a volume expansion of up to 280%. Such large volume expansions are detrimental to cell cycling, and therefore must be limited to some tolerable amount.
	One method of limiting volume expansion is by alloying Si with a transition metal (TM) forming an inert TM silicide, effectively reducing the amount of active Si; therefore, reducing the total volume expansion. Fe, because of its abundance in the earth’s crust and relative low cost, is an ideal candidate. Cr was additionally explored as the mechanical properties of Cr are different than those of Fe. SiTM alloys were generated by a commercially relevant mechanochemical synthesis and evaluated in Li metal half cells...


title: The Afterlife of Aid: An Ethnographic Study in KwaZulu-Natal, South Africa

subject:
medical anthropology
global health
South Africa
HIV/AIDS

abstract: Global health community-based interventions are habitually time-limited. Given their temporal nature, it is imperative to understand how these interventions impact, affect and shape people’s lives once these programs come to an end. Drawing on three months of ethnographic fieldwork in KwaZulu-Natal, South Africa after one global health intervention had ended, I argue that transient global health programs have lasting—often destabilizing—residual effects, especially impacting community social relations after they end. Specifically, by using anthropology’s field methods, I illuminate feelings of abandonment that resulted because of broad inclusion criteria of past programs and subsequently how the contraction of these programs has had fracturing effects on the status of community workers and on the patron-client bonds between community workers and their clients. Although global health organizations continue to advocate for community-based care, the nature of their short-lived interventions are weakening the social relations they rely on in the afterlife of aid.


title: FREESOUP.INFO

contributor:
School of Architecture
Master of Architecture
Diogo Burnay
Steve Parcell
Roger Mullin
James Forren
Not Applicable
No
No

subject:
thermodynamic chaos
free soup
non-isolated thermodynamic materialism

abstract: Humans have developed systems of extraction to harness power outside of the cycles occurring in our atmosphere. These systems use this imbalance of power to influence behaviour and reject our previous existence dominated by atmospheric flux. Additionally, they attempt to isolate pockets of inhabitation within this context, neglecting the laws of thermodynamics, which state that within our open system, nothing is isolatable; every boundary is that of thermodynamic dissipation. Despite this reality, architectural systems constantly attempt to define thresholds and enclosures, reinforcing false ideas of boundary within a universe where chaos is constantly increasing. FREESOUP.INFO introduces a deployable system to harness the abundant layer of dissipation latent in monopolizing systems in order to break down and make visible the oppressive hierarchies of power control. By occupying these false boundaries, the system feeds power back into the individual, providing a layer for free inhabitation, celebration and fun.


title: Design, fabrication, and performance of high-frequency phased-array ultrasonic endoscopes

contributor:
Department of Biomedical Engineering
Doctor of Philosophy
Dr. Christine Demore
Dr. Jeremy Brown
Dr. Jason Gu
Dr. Geoffrey Maksym
Dr. Kamal El-Sankary
Dr. Jeremy Brown
Not Applicable
Yes
Yes

subject:
Ultrasound
Minimally invasive surgical procedures
High-frequency
Piezoelectric
Diagnostic Imaging
Micro-fabrication

abstract:
With a rapidly aging population, there is an imminent need to reduce healthcare costs and improve patient outcomes. Minimally invasive surgical procedures have the potential to help facilitate this objective due to shorter recovery times and improved outcomes. However, challenges with the visualization of tissues limit the adoption of these procedures. This work aims to help advance clinical practice by developing new techniques to produce high-resolution ultrasonic endoscopes for minimally invasive surgical procedures.
Micro-fabrication techniques are incorporated into a novel endoscopic ultrasonic transducer design, allowing for a 64-element array with an element pitch of 38 μm and an encapsulated transducer size of 2.5 mm by 3.1 mm. Impulse response simulation scripts are developed and tested to aid in the design and construction of the transducers. Tests on wire-phantoms and cadaveric porcine tissue showed a dynamic range of up to 60 dB, an axial resolution of 40 μm, and a lateral resolution of 152 μm.
An experimental design using Vernier element spacings was developed, modeled, constructed, and tested to passively reduce the effects of grating lobe image artifacts at high steering angles. The design utilizes a 128-element transducer with every third element providing pulse transmission and every fourth element providing pulse reception. The Vernier array design reduced the intensity of grating lobe image artifacts by 15 dB relative to the previously constructed array. However, the transducer’s overall signal strength was attenuated by 18.2 dB, limiting the potential applications.
Kerfless array designs, without mechanical separation of the piezoelectric wafer be-tween elements, were investigated due to their improved manufacturability. Though existing literature and simulations predicted poor performance of the kerfless arrays, measurements of their acoustic radiation patterns showed higher signal levels at steer-ing angles beyond ± 20° than was expected. The simulation models were updated to include the effects of lateral acoustic emissions within the piezoelectric wafer. They provided a strong fit with experimental measurement, demonstrating the viability of kerfless array designs as a low-cost alternative to traditional arrays.


title: Natural [Re]connection: Facilitating the Development of Preschool Children Through Nature Rich Environments

contributor:
School of Architecture
Master of Architecture
Steven Mannell
Steve Parcell
Sarah Bonnemaison
Cristina Verissimo
Received

subject:
Early Childhood Development
Biophilia
Nature
Kindergarten
Halifax (N.S.)
Architecture

abstract:
Humans have an instinctive attraction to the living world and growing research suggests that interactions with nature makes us healthier and happier. Early childhood development theories demonstrates that it is essential that children are in contact with nature and this, as much as possible.

This thesis addresses early childhood group age and how to appropriately implement nature rich environments into an urban kindergarten in Halifax, Nova Scotia. The thesis also advocates for a more natural way of teaching where creativity, child led play and tactile learning are at core while demonstrating the importance of nature for children and lists multiple studies researching the consequences of restrain exposure to the natural world. Through biophilic design and the natural environment studies, this thesis aims to provide a framework that can be adapted to any urban setting educational facility.


title: FRICTION STIR PROCESSING OF 2xxx SERIES ALUMINIUM PM ALLOYS

contributor:
Department of Mechanical Engineering
Master of Applied Science
Uday Venkatadri
Dominic Groulx
Ian Donaldson
Paul Bishop
Not Applicable
Not Applicable
Not Applicable

subject:
Aluminium
Powder Metallurgy
Friction Stir Processing
Mechanical Properties

abstract: Friction stir welding (FSW) is a novel solid-state process known to facilitate the joining of materials that exhibit a poor response to conventional fusion welding technologies. Certain aluminium alloys in the 2xxx series are prime examples as their use in welded structures is desirable, but typically avoided in light of their acute sensitivity to solidification cracking. The desire to use these high strength alloys has historically resulted in less ideal joining methods such as brazing or riveting being implemented. To date, the majority of FSW research on these alloys has involved wrought products, leaving a clear void in the understanding of how those produced through aluminum powder metallurgy (APM) alloys respond. To address this shortfall, the response of two commercially relevant APM alloys denoted as PM2618 (Al-2.3Cu-1.6Mg-1Fe-1Ni-0.5Sn) and TC2000 (Al-1Mg-1.5Sn) to FSW was investigated in this study. The rotation speed and traverse rate of the tool were the principal process variables considered. In the PM2618 a variety of processing parameter combinations were found to produce defect-free welds when inspected through X-ray techniques coupled with metallographic inspection of polished cross sections. The stirred material was found to have a highly refined microstructure, showing an increase in hardness but without any apparent change to the nominal phase composition. Bend testing revealed significant improvements as a result of FSW. These included a near doubling of ductility, an average increase in yield strength in bending of 33%, and a 35% improvement in UBS. Bending fatigue behaviour was also investigated, with averaged gains of 27% measured relative to the as-sintered base material. Conversely, it was found that the TC2000 responded negatively to all processing parameter combinations used. While the stirred material in the microstructure exhibited a similar degree of refinement as seen in the PM2618, through X-ray examination it was found that specimen also contained tunnel defects and voids to varying extents.


title: SEA: A Framework to ensure Security, Efficiency, Availability of Dynamic Wireless Sensor Network

contributor:
Faculty of Computer Science
Master of Computer Science
Dr. Michael McAllister
Dr. Qiang Ye
Dr. Musfiq Rahman
Dr. Srinivas Sampalli
Dr. Saurabh Dey
Not Applicable
Not Applicable
Not Applicable

subject:
Wireless sensor networks
Distributed ledger technology
Blockchain
Radix DLT
Memory management
SEA
Cryptography
Logical clocks

abstract:
Growing demand for the wireless sensor network has made it a hot research area and a new technology trend. Since sensor network technology can adapt to its environment, draw conclusions and learn from it, it makes more strategic use of the application environment in an efficient manner. It has now become widely available to deliver various advantages, from convenience, security, efficiency to time and money savings. Studies show that in the near future, wireless sensor networks will become more of an essential part of our lives than our actual personal computer. It is changing the face of the world altogether.

The wireless sensor network base station, which acts as a processing unit and gateway for all sensor data, is believed to be free from security threats. Unattended wireless sensor networks, however, should treat security as a primary concern, because it collects and processes sensitive data within networks. When the base station is compromised, the sensors connected to it are at risk and communications in the network are adversely affected. Significant security concerns surrounding these specifications include threats such as eavesdropping, data falsification, denial of service and disruption of physical nodes.

The proposed SEA (Security, Efficiency and Availability) framework is motivated from highly secure and scalable distributed ledger technology called Radix. The framework is designed to meet wireless sensor network security requirements using minimum replication and various key techniques. It promotes the use of public key cryptography among base stations to securely distribute keys, data, commitments and clocks. The proposed replication allows the network to continue functioning without data loss and ensures the availability of the network. In addition, it can withstand vulnerabilities, such as man-in-the-middle and replay attacks. The proposed memory management scheme is validated in terms of memory storage and secure communication configuration. The security of message exchange in this framework is evaluated using Scyther protocol analyzer. The research findings exhibit that the solution proposed ensures security, efficiency, and availability of dynamic wireless sensor networks.


title: MAST CELLS AND INTERFERONS AS A NOVEL APPROACH TO IMMUNOTHERAPY USING A MURINE BREAST CANCER MODEL

contributor:
Department of Microbiology & Immunology
Master of Science
Dr. Paola Marcato
Dr. Brent Johnston
Dr. Brent Johnston
Dr. Chris Richardson
Dr. Jean Marshall
Received
Not Applicable
Not Applicable

subject:
mast cells
cancer immunotherapy

abstract: Breast cancer has the second highest mortality in women diagnosed with cancer-related disease. Immunotherapy, a strategy targeting regulation of the immune system to combat tumour growth has demonstrated therapeutic potential. Mast cells are sentinel cells of the innate immune system, known to secrete mediators with anti-tumour properties, such as interferons (IFNs) that can enhance anti-tumour immunity or directly kill tumour cells. The feasibility of mast cell-mediated IFN delivery was examined. Mast cells were genetically modified to express a target IFN following induction. This technology was tested using mast cell-deficient mice. Local mast cell reconstitution, with control mast cells, resulted in significant breast tumour growth reduction, in wild type and mast cell-deficient animals. Mast cells modified to deliver local IFN-1 on induction yielded no further reduction. Our findings implicate local mast cells as a potentially important therapeutic target in breast cancer while treatments using IFN delivery require further optimization.


title: Mundane Intimacies and Everyday Violence in Contemporary Canada Comics

contributor:
Department of English
Doctor of Philosophy
Dr Candida Rifkind
Dr Kathy Cawsey
Dr Anthony Enns
Dr Michele Byers
Dr Erin Wunker
Not Applicable
Not Applicable
Not Applicable

subject:
Comic books, strips, etc.
Canadian literature
Graphic novels

abstract: This dissertation argues that contemporary Canadian comics construct a sustained and critical gaze of the mundane and the everyday. Canadian artists are using the form of comics to reveal the structures of oppression and violence that are so familiar as to become mundane. My introduction lays out the theoretical framework of the everyday and argues that it is well-suited to the study of Canadian comics. The first chapter examines Kate Beaton’s webcomics, which reveal the environmental, cultural, and economic damage of Canada’s petroculture. I use Rob Nixon’s concept of slow violence to argue that Beaton’s mundane gaze brings nuance to her personal experiences with Canada’s Tar Sands. In my second chapter, I read Emily Carroll’s horror comics, Jillian Tamaki and Mariko Tamaki’s graphic novel Skim, and the graphic novel Will I See? as examples of a new gothic girlhood graphic. Read together, these texts reveal that there is nothing mundane about girlhood. Everyday, girls are vulnerable to the intersecting violences of racism, colonialism, heteronormativity, and patriarchy. My third chapter takes up comics’ potential as a spatial form through two comics about access to space, Ting Chak’s graphic essay Undocumented: The Architecture of Migrant Detention and Eric Kostiuk Williams’s graphic novel Condo Heartbreak Disco. Both comics use the spatial dynamics of comics to trace oppression and resistance across what David Harvey conceptualizes as broad spatiotemporal scales. My fourth chapter argues that artist-activist Gord Hill produces comics that are pedagogical in content and form. I build on Dale Jacobson’s concept of multimodal literacy to argue for Hill’s attention to the imagery, rhetoric, and style of fascism and colonialism. Hill’s comics argue that one must be able to read these oppressive movements if one is to undo them. I conclude by recognizing that the everyday is far from boring, and that mundanity can serve as a cover for persistent violence and abuse of power. Comics serve as a powerful form, as they work to reveal these structures of oppression, invite solidarity, and imagine paths of resistance.


title: An Automated and High-Throughput (HTP) Method for Adenosine Triphosphate (ATP) Quantification

contributor:
Department of Civil Engineering
Master of Applied Science
Dr. Hany El. Naggar
Dr. Rob Jamieson
Dr. Vincent Sieben
Dr. Graham Gagnon
Dr. Amina Stoddart
Not Applicable
Not Applicable
Not Applicable

subject:
Adenosine triphosphate
ATP
High-throughput Method
HTP
HTS
Method Development
Microbial water quality monitoring

abstract: Exposure to microbial contamination through drinking water is a major global health concern, therefore, it requires rapid detection equipment to maintain microbial stability at the tap. Currently, microbial quality is monitored through time-consuming laboratory methods which causes delayed response. This study demonstrates the development of an automated and high-throughput (HTP) method for the measurement of microbiological activity in water, through the quantification of cellular adenosine triphosphate (ATP). The developed method was able to efficiently and accurately quantify cATP in raw water samples from treatment plants simultaneously. In addition, it proved to be 5x faster and as accurate (p= 0.911) as the Standard Test Method for Adenosine Triphosphate (ATP) Content of Microorganisms in Water (ASTM D4012). This developed method has potential to represent a significant advancement for microbial monitoring and could benefit utilities interested in monitoring the biological activity of water, the health of biofilters, and the effectiveness of disinfection strategies.


title: A NEAR OPTIMAL SOLUTION FOR MAXIMUM RELEVANCE MINIMUM REDUNDANCY FEATURE SELECTION

contributor:
Faculty of Computer Science
Master of Computer Science
Dr. Michael McAllister
Dr. Evangelos Milios
Dr. Vlado Keselj
Dr. Nur Zincir-Heywood
Received
No
No

subject:
Feature selection
Submodular
Classification

abstract: In many real-world applications, a high number of features could result in noisy and redundant information, which could degrade the general performance of classification tasks. Feature selection techniques with the purpose of eliminating such features have been actively studied. In several information-theoretic approaches, such features are conventionally obtained by maximizing relevance to the class while the redundancy among the features used is minimized. This is an NP-hard problem and still remains to be a challenge. This research proposes an alternative feature selection strategy on binary text representation data based on the properties of submodular functions, with the purpose of providing a theoretical lower bound for finding a near optimal solution based on the Maximum Relevance-Minimum Redundancy criterion. In doing so, the proposed method can achieve a 2-approximation by a naive greedy search. Empirical experiments validated and benchmarked against different baseline methods show that the proposed technique is a promising approach on binary data in general.


title: Investigating the role of the anaerobic protist Blastocystis in the gut microbiome by metagenomic analysis

contributor: Department of Biochemistry & Molecular Biology

subject:
Blastocystis
gut microbiome
metagenome

abstract: Blastocystis are amongst the most prevalent microbial eukaryotes inhabiting the gastrointestinal tracts of mammals. A bioinformatic workflow was developed to detect Blastocystis in gut metagenomic data and applied to 996 publicly available metagenomic sequencing datasets from fecal samples of humans and animals. Blastocystis incidence was determined to be 52.7% in human and 62.6% in animal samples. A Blastocystis subtype-specific distribution was observed both in human and animal carriers and associations between microbial community composition and subtypes was confirmed for humans. Specifically, the Methanobrevibacter genus, Prevotella copri, and species from the Firmicutes phylum were positively associated with the presence of Blastocystis. A tool, Eukfinder, was designed to recover protistan genome sequences from metagenomic data and successfully retrieved five near-complete nuclear genomes and mitochondrial genomes of Blastocystis. Overall, these bioinformatic workflows for analysis of metagenomic data performed well to detect difficult-to-cultivate protists, investigate their genomic diversity and their impact on prokaryotic microbiota.


title: Support Systems for Inclusive Post-Secondary Education: A Case Study on The University of Winnipeg’s ACCESS Education Programs.

abstract: Key Words: equity, access to education, community, supports, belonging, inclusive learning

abstract: The goal of this study is to understand the importance of inclusive learning practices in post-secondary education to alleviate social barriers for underrepresented students. There is a disconnect between access to university and ongoing support systems within and outside the classroom. This problem can attributed to a long history of exclusive, euro-centric post-secondary structure that is often unwelcoming to underrepresented students. This thesis will discuss the social barriers to underrepresented students and the practices being implemented by intuitions to provide equitable, inclusive access to higher education. Then, it will use the ACCESS Education Programs at The University of Winnipeg as a case study to evaluate the support systems offered to students in 3 programs: Winnipeg Education Centre, Community-Aboriginal Teacher Education Program, and Immigrant Teacher Education Program. Through qualitative, open-ended interviews and a focus groups, this study explores what support systems are working at ACCESS Education to create a welcoming learning environments for their students.


title: Exploring the Relationship Between Culture and Health on Nigerian Food Blogs

subject:
Nigerian Health
culture
health
Food--Blogs--Nigeria
Nigerian culture
Nigerian health
food and culture
Content analysis (Communication)
Principal components analysis

abstract:
This study explores the relationship between culture and health on Nigerian food blogs through content and componential analysis. I sought to understand what elements constitute certain dishes, such as the staple of “soup” through sampling common Nigerian recipes discussed across selected blogs.
Out of over 54 soups with over 220 variations, it was discovered that only seven of these soups had consistent patterning across the blogs sampled. An additional finding was a strong relationship between food and health emphasized on the blogs.


title: Accessibility’s Impact on the Information Literacy of the Deaf Community

contributor: Master of Library and Information Studies

subject:
Deaf Community
Deaf Culture
Deaf Epistemology
Information Literacy
Information Literacy Instruction
Deaf Information Literacy Skill
Knowledge Management
Community of Practice
Deaf Education

abstract: This Master’s thesis explores access and accessibility and how they impact information literacy in the (d)eaf community. Information literacy is the ability to locate, evaluate, and effectively use the information the individual needs. Using Narrative Inquiry, participants from the Nova Scotia (d)eaf Community were interviewed about access, accessibility, and information literacy. Participants were asked to reflect on how they typically look for, use, and understand information throughout their daily, professional, and educational lives —as well as what role technology plays in those processes. Contrasts in the epistemological understanding of access and accessibility between the (d)eaf Community and the hearing world are highlighted. The results of this study give us a clearer picture of the current information literacy skills of the Nova Scotia (d)eaf Community, along with presenting overarching themes of mental health, accessibility, education, privacy, and the role of the (d)eaf community in information literacy development and practice.


title: Development and implementation of Water Safety Plans in Canadian water systems

contributor:
Department of Civil Engineering
Doctor of Philosophy
Edward McBean
Hany El-Naggar
Rob Jamieson
Gordon Fenton
Graham Gagnon
Not Applicable
Yes
Yes

subject:
drinking water
water quality
risk assessment
water safety planning

abstract:
Current, persistent water quality and quantity concerns in small, rural, Northern and Indigenous water systems in Canada necessitate a change in water management strategies.  Analysis of drinking water advisories across water systems reveals the predominance of operational concerns in water systems that are not addressed by the current regulatory structure mandating water quality sampling.  Regionalized water governance and fragmented policy making do not account for all stakeholders in a water system and do not contribute to consumer confidence in the provision of safe water in Canadian water systems.  This situation is exacerbated in small and geographically remote communities with limited access to the resources or the capacity to adequately address operational and water quality concerns.  Focus needs to be placed on improving management of water systems to improve not only capacity to meet water quality guidelines, but to solve operational concerns through a more proactive strategy.
This dissertation examines the applicability of the water safety planning approach, a proactive risk management strategy, to water systems in Canada.  Implementation and adoption of water safety plans relies heavily on water system environment: the attitudes and preconceived ideas about water safety through which stakeholders evaluate new management tools.  This research focuses on understanding factors that form barriers to water safety planning implementation in both municipal and First Nation water systems.  This research begins with a review of water safety planning literature and the drinking water advisory as the current water safety tool in Canada.  Based on the benefits and challenges identified in this method, a water safety plan tool was developed specifically for this thesis and tested by consulting water system stakeholders.  This tool was reviewed by both municipal and First Nation water systems.  Additionally, focus was placed on determining strategies for presenting the information generated through the water safety planning process and examining strategies for adding water quality data to the water safety plan.  The water safety plan tool shows promise as a management method for water systems, but successful and sustainable implementation will require a shift in water system culture from reactive water quality monitoring to proactive operational practices.


title: Tradition and Authoritarianism as a Solution to Social Decay- An Analysis of Canadian Right- Wing Extremism Online

contributor: Department of Sociology & Social Anthropology

subject:
whiteness
social media
content analysis
Canada
right-wing extremism

abstract: Recently, Canadian researchers have turned their attention to online right-wing extremism. For this research I conducted a content analysis of 300 Facebook and Twitter posts from the accounts of three Canadian right-wing extremist groups: Yellow Vests Canada, ID Canada and the Soldiers of Odin BC. My research examines the key claims right-wing extremist groups make about Canadian identity, belonging and politics and how they justify these claims. I found that they make four key claims on social media: that Canadian identity is white, that Canadian values are traditional values, that society is decaying, and that authoritarian governments should be elected. However, these claims are not overt, rather right-wing extremist groups discuss apolitical topics such as rising crime and misplaced white guilt. These topics together convey a particular message that is in keeping with what literature suggests are extremist groups ideological beliefs such as racial nationalism, strong states, and online mobilization.


title: NCK1 FUNCTIONS IN THE BRAIN TO REGULATE DENDRITIC SPINE FORMATION, COGNITION, AND BEHAVIOUR

contributor:
Department of Pharmacology
Doctor of Philosophy
Dr. Timothy E Kennedy
Dr. Morgan Langille
Dr. George Robertson
Dr. Jason McDougall
Dr. James P Fawcett
Received
Not Applicable
Not Applicable

subject:
NCK
LEARNING
MEMORY
ANXIETY
DENDRITIC SPINES
AMYGDALA
HIPPOCAMPUS
ACTIN DYNAMICS

abstract:
NCK1, encodes for the non-catalytic region of tyrosine kinase adaptor
protein (NCK1). NCK1 has previously been shown to modulate cellular actin,
although its role in CNS development and function remain unknown. Here, I
examined neurodevelopmental and behavioural defects using a murine model in
which NCK1 was inactivated. I show that NCK1 is ubiquitously expressed in
neurons throughout the brain but does not grossly affect neuronal development.
However, loss of NCK1 leads to defects in memory, learning, and in anxiety-like
behaviours. Examination of the hippocampal region revealed that NCK1 is
necessary for normal synaptic density, and morphology of the postsynaptic
density. Mechanistically, NCK1 affects synaptic structures by regulating the rate
of actin turnover and polymerization, suggesting that NCK1 functions intrinsically
in neurons to stabilize actin dynamics and promote synaptic integrity. In addition
to memory defects, mice lacking NCK1 show context dependent defects in
anxiety-like and stress hormone responses. These defects are ameliorated with
treatment with Diazepam. The anxiety-like defects is linked with a loss of
synaptic density in the basal lateral amygdala (BLA) and decreased neuronal
activation in the prefrontal cortex and in inhibitory interneurons of the BLA,
implicating NCK1 in inhibitory control of circuits important for regulating anxietylike behaviours. Combined, my work suggests that NCK1 functions in the CNS to
stabilize synaptic actin dynamics necessary for the development of neuronal
circuits important for learning, memory and anxiety-like behaviours.


identifier: Walter, E.M. (2020). Process tracing the Trans-Pacific Partnership (TPP) in Canada and New Zealand: Understanding the inclusion of Indigenous peoples in trade negotiations. College of Sustainability Honours Theses.

title: Process Tracing the Trans-Pacific Partnership (TPP) in Canada and New Zealand: Understanding the Inclusion of Indigenous Peoples in Trade Negotiations

abstract: Key Words: Trans-Pacific Partnership (TPP), Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), Free Trade Agreements (FTAs), international negotiations, Indigenous peoples, Māori, public consultation, legal obligations, two-level games, and inclusive treaty-making.

abstract: In attempts to achieve ‘reconciliation’ in a globalized world, several governments are seeking to advance the goal of ‘progressive trade’ (NZMFAT, 2020c; Government of Canada, 2018a). Yet it is uncertain whether current free trade agreements (FTAs) uphold the principles of reconciliation, and whether they are inclusive of Indigenous interests (UN General Assembly, 2015; Waitangi Tribunal, 2016). There is little knowledge regarding how Indigenous peoples participate in global trade negotiations, which creates a research gap (Kawharu, 2016; Schwartz, 2017; Dalhousie Law Professor, personal communication, March 3, 2020). To address this gap, this thesis uses process tracing through a document analysis to understand how Indigenous peoples in Canada and Māori in New Zealand participated in negotiations for the Trans-Pacific Partnership (TPP) free trade agreement. An analysis of the legal obligations these countries have to domestic stakeholders in international treaty-making provides insight to the often exclusive decision-making process at the international level. Weak and minimal legal obligations for countries such as Canada and New Zealand to include stakeholders, and especially Indigenous peoples in international treaty-making leads them to achieve the ‘bare minimum’ of domestic inclusion in order to ease the complexity of two-level games (Putnam, 1988; Kindred et al., 2014; Waitangi Tribunal, 2016; Sanderson & Willms, 2019). While Indigenous peoples are often not specifically targeted in these exclusive processes, the most marginalized groups in society are often heard the least (“Native Affairs”, 2015; Palmater, 2016; Amnesty International, 2020). There are opportunities for more inclusive decision-making to occur, especially in Canada, where governments could look to New Zealand as a first step towards more meaningful engagement with Indigenous peoples (Cywink, 2017). For Canada and New Zealand to work towards rebuilding relations with Indigenous peoples, more inclusive treaty-making processes at both the domestic and international levels are needed.


identifier: Boardman, S. (2020). Exploring the Governance Outcomes of Social Learning through the Indigenous Circle of Experts (ICE) work with Indigenous Protected and Conserved Areas (IPCAs). Thesis.

abstract: As Canada strives towards meeting Target 1 of conserving at least 17 percent of terrestrial areas and inland water, and 10 percent of coastal and marine areas by 2020, Indigenous protected and conserved areas (IPCAs) are viable options to completing Target 1. One important group doing work with IPCAs was the Indigenous Circle of Experts (ICE). ICE formed in 2017 to examine how Canada’s Target 1 would be met equitably and influence the development of IPCAs. They released their report in 2018 providing recommendations for governments and Indigenous Nations across Canada in implementing IPCAs. This paper examines the social learning and collaboration throughout their work and the media surrounding IPCAs currently using social learning and governance theory. This research found collective learning and a true collaborative process enabled ICE to be effective. In media a paradigm shift around Indigenous people’s importance in conservation occurred in the mainstream with more support for Indigenous led conservation and IPCAs. ICE’s collaborative learning will pave the way forward in reconciliation, equitable IPCAs and truly Indigenous-led governance.


title: VALORIZING INDUSTRIAL BYPRODUCTS - PAPER MILL PULP SLUDGE AND DRYWALL THROUGH THE DEVELOPMENT OF HIGH-QUALITY GROWTH MEDIUM

contributor: School for Resource & Environmental Studies

subject: pulp drywall mill greenhouse tomato sludge industrial paper gypsum substrate peat

abstract: Master of Environmental Studies - Thesis.

abstract: The human population continues to rise and projections suggest there will be nine billion people on earth by 2050. Food consumption patterns continue to indicate there will be a need to significantly increase agricultural production, to meet the rising demand for food. This brings into focus the need to develop novel ways as part of planning for future demands while using the same amount of land and minimizing environmental impacts. With a lens on increasing regional food production; combinations of waste cellulose fiber sludge from Port Hawkesbury paper mill and gypsum from Cabot Gypsum, Nova Scotia, were used to cultivate Little Bing tomato (LBT) (Solanum lycopersicum), comparing growth rates and quality against commercially available peat moss. Results demonstrated it is possible to produce LBT in pulp-gypsum blends. This could lead to the diversion of several thousand tons of waste pulp sludge and drywall from landfills each year.


title: DEGRADATION OF ELECTRIC VEHICLE LITHIUM-ION BATTERIES IN ELECTRICITY GRID SERVICES

contributor:
Department of Mechanical Engineering
Master of Applied Science
Tim Little
Farid Taheri
Dominic Groulx
Lukas Swan
Not Applicable
Not Applicable
Not Applicable

subject:
electric vehicle
Li-ion battery
Electricity Grid
NMC
LFP
LMO

abstract: It has been proposed to repurpose retired electric vehicle (EV) lithium ion batteries (LIB) into stationary electricity grid services. This thesis investigates the performance characteristics of two popular leading commercial EV LIBs, with NMC+LMO and LFP positive electrodes. The energy electricity service of energy arbitrage (EA) and power electricity service of frequency regulation (FR) are compared. LIB performance was compared on the basis of energy capacity degradation throughout cycle life, round trip energy efficiency, and thermal response. Additional diagnostics methods including SEM, EDS, half-cell testing, impedance growth and differential voltage analysis were used to determine why each LIB degraded. The results give useful insight into which EV LIB chemistries are most appropriate for which electricity grid application. It was found that EA degrades LIBs twice as fast as FR. NMC+LMO degrades twice as fast as LFP but is more energy efficient.


title: The “Mouseland” Metaphor: How Rhetoric and Affect can Mobilize Political Change

abstract: Audiences use their own methods of verbal and emotional persuasion, which has created a gap of understanding between them and diminishes the ability for a consensus and removes opportunities for widespread political mobilization to occur. This paper analyzes Tommy Douglas’s 1944 performance of “Mouseland”, a metaphorical speech representing the Canadian Parliamentary system that has succeeded in removing the communication gap between members of different domains, or audiences. The speech’s impact continues today, with references to Douglas’s performance recurring in a variety of contexts. “Mouseland” is written as an affective metaphor whose purpose is to persuade an audience through affect. Douglas, the speaker, uses a comical metaphor to accomplish this affective response in his audience, which provides an example for how a speech can act beyond the confines of language into the emotional realm for the purposes of persuasion and mobilization. Persuasion and mobilization are two key aspects of political decision-making, and are crucial in creating structural political change.


title: SPACE TO ROOST: WORKING WITH RECREATIONAL BEACH USERS TO SET ASIDE HIGH-TIDE ROOSTING SPACE FOR MIGRATORY SHOREBIRDS IN THE MINAS BASIN OF THE BAY OF FUNDY, NOVA SCOTIA, CANADA

subject:
Shorebirds
Collaborative conservation
Human dimensions of wildlife management
Social normative theory
Conservation
Bay of Fundy
Minas Basin
The Guzzle
Birds Canada
High tide roosting

abstract: Migratory shorebird numbers are dropping, making shorebird conservation a necessity. Although conservation must incorporate human values, it is uncommon to develop strategies in collaboration with those seen as causing challenges. Through site audits, we identified anglers, photographers and others as causing shorebird disturbance at a roosting site in Nova Scotia. Through in-person surveys, an online survey, education, and outreach, we worked with recreational users to set aside a ‘Shorebird Resting Beach’ (SRB). Employing signage, handouts, and researcher presence, we asked users to avoid this beach from two hours before and after high tide in August. Baseline surveys of users and disturbance in 2016 were repeated in 2017 and 2018 when the SRB was launched. On the SRB, we found an overall decrease of 82% in the hourly rate of human-caused disturbance in 2017 from 2016, a 73% decrease from 2018 to 2016, and a 48% increase from 2017 to 2018. The number of users that went down to the SRB from the dyke dropped from just over half in 2016, to less than 10% in 2017 and 2% in 2018. The SRB had nearly half the hourly rate of disturbance of Middle Beach in 2016 and 2017, and a third in 2018. The SRB had less than a third of the rates of disturbance of East Beach in 2017 and 9.5 times less in 2018. Future work should include shorebird-human avoidance as a disturbance category and account for the proportion of birds disturbed of total shorebirds present. The implementation of SRBs shows promise as an effective tool when managers are confronted with conflicts between shorebirds and beach users.


title: TOXICITY OF A BRINE EFFLUENT ON EARLY LIFE-STAGE AND JUVENILE STRIPED BASS (MORONE SAXATILIS)

contributor:
Faculty of Agriculture
Master of Science
Dr. Gordon Price
Dr. Janinie Gray
Dr. Stefanie Colombo
Dr. James Duston
Received
Yes
Yes

subject:
Striped bass
Shubenacadie River
Alton Gas
Brine
Toxicology
Salinity Tolerance

abstract: The striped bass of the Shubenacadie River, in Nova Scotia, Canada are an important part of the Bay of Fundy population which is considered endangered by COSEWIC.  The estuary is key striped bass nursery habitat and the site of the planned controlled release of a brine effluent created via formation of natural gas storage caverns. Therefore, the toxicity of the brine was quantified on the sensitive early life stages including eggs, larvae, and juveniles.  The median lethal concentration of brine on striped bass ranged between 30.9-65.7 ppt, which is above a regulatory mandated 28 ppt maximum threshold for the release of brine.  Threshold-observable-effect concentrations were also more than this threshold value 30.8-59.7 ppt excluding 2 conditions. Changes in salinity tolerance were related to ontogenetic development, relating to behaviour and physiology. These data suggest the current plan to release brine poses little risk to the bass.


title: Quantum State Preparation Using Chirped Laser Pulses in Semiconductor Quantum Dots

contributor: Department of Physics & Atmospheric Science

subject:
quantum control
quantum dots
adiabatic rapid passage
LA phonon eid

abstract:
A quantum emitter (QE) is a physical system that can be used to encode a quantum state via some internal degree of freedom (e.g. exciton, electron spin, valley) and is coupled to light via a dipolar transition that enables the conversion of that quantum state into the state of a photon and vice versa.  Such QEs can be applied to sources of single and entangled photons for applications in quantum cryptography or quantum imaging and a collection of coupled QEs can be used to realize a small quantum simulator or quantum memory node in a distributed quantum network. Among solid state QE systems, semiconductor quantum dots (QD) are particularly attractive due to their high radiative quantum efficiencies, their strong optical coupling, enabling fast  and arbitrary  qubit rotations, and their tunable emission in the range of standard telecommunication wavelengths. Adiabatic rapid passage (ARP) is a state preparation scheme that enables the excitation and de-excitation of a QE with a high fidelity even in the presence of fluctuations in experimental parameters such as intensity and frequency of the control laser pulse. This excitation scheme may be used for quantum state initialization in quantum information platforms and for triggering quantum light sources.

This thesis work concerns an exploration of the efficacy of ARP for the quantum control of excitons in semiconductor QDs. The experiments carried out in this work show that the impact of phonons may be suppressed for ARP, pointing to the possibility of high-fidelity inversion at elevated temperatures. We also investigate the dependence of the threshold for decoherence suppression on the size and shape of the QD. The experiments performed in this thesis work also quantify the detuning tolerance of ARP. ARP was also used to demonstrate parallel quantum state initialization in two different QDs with different transition energies and dipole moments.


title: Applying Geographic Information Systems to the Study of Honey Bee Diseases and Pests

contributor:
School of Information Management
Master of Information
James Boxall
Janet Music
Dr. Bertrum MacDonald
Dr. Chris Greene
Jennifer Grek Martin
Not Applicable
Not Applicable
Not Applicable

subject:
GIS
Geographic Information Systems
Honey Bee
Honeybee
Honey bee Disease
Honeybee disease
Nova Scotia
Agriculture
Honeybee pest
Honey bee pest
Chalkbrood
American Foulbrood

abstract: The western honey bee (Apis mellifera) is one of the most valuable pollinators in the global agriculture industry. However, recent years have seen a decrease in the worldwide honey bee population through colony collapse, disease, pests, urban growth, climate change, and the increased use of pesticides. This thesis explores the quality of open data available to researchers interested in understanding the geographic distribution of honey bee diseases and pests in Nova Scotia, Canada, and identifies locations within the province that may be vulnerable for honey bees. Results of a Land Suitability Analysis using geographic information systems (GIS) software show that GIS can be used to identify regions that meet certain conditions related to disease and pest development. However, this research concludes that more credible, relevant, and legitimate information needs to be accessible through data portals and requests for information for GIS to be more useful in this capacity.


title: MUSCLE SPINDLE FEEDBACK AND LIMB COORDINATION DURING LOCOMOTION

contributor:
Department of Medical Neuroscience
Doctor of Philosophy
Dr. Ansgar Büschges
Dr. Kazue Semba
Dr. Victor Rafuse
Dr. Ying Zhang
Dr. Turgay Akay
Received
Yes
Yes

subject:
Sensory feedback
Proprioceptors
Sensorymotor control
Locomotor activity
Movement disorders

abstract: Understanding how the nervous system controls locomotion is of great importance to improve treatments of mobility disorders. The numerous muscles and joints in a limb participating in a given movement, have to feed sensory information back to the central nervous system, so that, individuals have the capacity to perform functional movements and cope with diverse environmental variables. The integration of proprioceptive feedback derived from muscle spindles and Golgi tendon organs into the central nervous system is still a fascinating topic requiring a deeper understanding. We have analyzed locomotor patterns in different behavioral conditions in mice, in which proprioceptive feedback was genetically removed or attenuated by adeno-associated virus technology. Our results showed that proprioceptive feedback from muscle spindles and Golgi tendon organs are essential for the coordination of flexor and extensor muscles necessary for functional terrestrial locomotion or swimming. Wide-spectrum muscle spindle feedback deficiency changed muscular activation patterns, generated incapability to precisely target the limbs after a stumble event during walking, and harmed the regulation of muscle activity-strength or speed-dependent EMG amplitude. Our results show that the ablation of proprioceptive feedback from an individual group of muscles, neither diminished functional locomotion nor altered muscle activation pattern. Nonetheless, the feedback from muscle spindles of the ankle extensor muscles, the triceps surae, is the main source of speed-dependent modulation of activity-strength, in contrast to the muscle spindle feedback from the knee joint which has no influence on speed-dependent amplitude modulation. We conclude that proprioceptive feedback is essential for controlling variable aspects of locomotion. The group Ia/II and Ib afferents carry the information used by the spinal cord to control muscle activity strength and regulate the onset and offset-timing of muscle activity patterns during locomotion.


title: ENHANCING NATURAL ORGANIC MATTER REMOVAL IN AN ULTRAFILTRATION MEMBRANE PLANT THROUGH COAGULATION

contributor:
Department of Civil Engineering
Master of Applied Science
Dr. Hany El Naggar
Dr. Margaret Walsh
Dr. Azadeh Kermanshahi pour
Dr. Graham Gagnon
Not Applicable
Not Applicable
Not Applicable

subject:
Water quality
Natural organic matter
Coagulation

abstract:
Four polyaluminum chlorides were tested in bench-scale coagulation experiments to determine an optimal pH and dose for each, while also establishing an ideal treatment option for a small water treatment plant in Nova Scotia for removal of natural organic matter. PAC-A, PAC-B, PAC-C, and PAC-D were coagulated using raw water from Pottle Lake Water Treatment Plant at pH 5.5 and 6.5, and it was determined that the optimal pH for all coagulants was pH 6.5.
 There was no statistically significant difference in overall reduction of natural organic matter between any of the polyaluminum chlorides tested, indicating that each coagulant effectively removed natural organic matter equally. All four coagulants showed promising results in removing precursors of disinfection by-products for Pottle Lake Water Treatment Plant, but the optimal PACl coagulant was determined to be PAC-A-1.8 at pH 6.5 due to its reduction of UV254, turbidity, and specific UV absorbance (SUVA).


title: Investigation into mechanisms of treatment resistance and heterogeneity in breast cancer and acute promyelocytic leukemia

contributor:
Department of Pathology
Doctor of Philosophy
Dr. Sherri Christian
Dr. Paola Marcato
Dr. Graham Dellaire
Dr. Carman Giacomantonio
Dr. Morgan Langille
Dr. Paola Marcato
Received
Yes
Yes

subject:
BCL6
Breast cancer
APL
CSCs
Immune interaction

abstract:
Treatment failure remains a leading contributor to cancer related death despite considerable advances in detection and treatment approaches. Several factors contribute to treatment failure including the high degree of tumor heterogeneity across patient populations and within individual patient tumors. While this heterogeneity can present an obstacle to successful treatment, it can provide new possibilities for personalized approaches to target resistant cancers and achieve better outcomes. This can be achieved through predicting patient response to different drugs to determine which treatment would be most effective as well as determining resistance mechanisms so that treatment strategies can be tailored to avoid these mechanisms.
In this body of work, we utilized breast cancer and acute promyelocytic leukemia (APL) models to investigate resistance mechanisms associated with different therapies and the potential effect of using combination therapy to reduce resistance and enhance treatment outcome.  Cancer stem cells (CSCs) are a source of tumor heterogeneity and facilitate tumor initiation and progression. To determine the role of different breast CSCs in the interplay with the immune system, we analyzed the differential expression of immune genes in the Aldefluor+ and CD44+CD24- breast CSCs and demonstrated that Aldefluor+ cells silence a key antigen presentation gene leading to their enhanced survival under immune pressure. Next, I applied a genome-wide shRNA screen to identify potential mediators of paclitaxel resistance in breast cancer, which is a common problem in the treatment of the cancer. This led to the identification of B cell lymphoma 6 (BCL6) as a contributor to paclitaxel resistance. I demonstrated enhanced tumor growth suppression in breast tumors treated with a BCL6 inhibitor and paclitaxel, suggesting a potential combination therapy that could be used overcome treatment resistance in breast cancer patients. Finally, I investigated the lasting benefits of combination treatment all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) treatment in APL cells. Only combination therapy was able to induce sustained demethylation and expression of target genes and in turn lasting changes in differentiation. Together, these studies highlight the importance of the studying heterogenous populations of tumors and mechanisms of resistance to inform strategies for combination treatments and improve patient outcomes.


title: OPTIMIZATION OF THE NAVAL SURFACE SHIP RESOURCE-CONSTRAINED PROJECT SCHEDULING PROBLEM

contributor:
Department of Industrial Engineering
Master of Applied Science
Dr. Majid Taghavi
Dr. Ahmed Saif
Dr. Uday Venkatadri
Dr. Claver Diallo
Dr. Alireze Ghasemi
Not Applicable
Not Applicable
Not Applicable

subject: RCPSP Ship Naval Scheduling Buffer Overtime Priority Maritime MILP

abstract: The research presented in this thesis focuses on proposing effective methodologies, formulations, and heuristics for scheduling and rescheduling resource-constrained project scheduling problems that are specific to naval surface ship work periods or similar maintenance projects. The network topology for these work period projects is divided into precedence-independent work orders that have precedence-dependent operations within themselves. Mixed-integer linear programming (MILP) models are developed for the initial scheduling and for the rescheduling problem. In initial scheduling, the objective is to front-load work based on priority and duration, to account for the high degree of uncertainty and scope growth that is common in these work periods. In rescheduling, the goal shifts to minimizing schedule deviation-days while incorporating urgent scope growth. Experimentation results, discussions, and insights are provided for initial and rescheduling MILP models, and for combining appropriate heuristic methods to quickly produce good feasible solutions when optimal solution times are not acceptable.


title: Matheuristic Optimization Approaches for Large Scale Resource Constrained Scheduling Problems in Refit Operations

contributor:
Department of Industrial Engineering
Master of Applied Science
Dr. M. Ali Ulku
Dr. Ahmed Saif
Dr. Pemberton Cyrus
Dr. Claver Diallo
Dr. Alireza Ghasemi
Not Applicable
Not Applicable
Not Applicable

subject: Matheuristics RCPSP SSGS

abstract: This thesis will discuss the development of matheuristic methods for scheduling the refit activities in the naval surface ship work period problem (NSWPP). The NSWPP is a variant of the classical resource-constrained project scheduling problem (RCPSP) with specific network structure and constraints. The NSWPP is a non-deterministic polynomial-time hard problem whose solution becomes computationally demanding as the problem size increases. Therefore, a matheuristic method called multi-step optimization (MSO) is developed in this paper, which combines heuristics and mixed-integer linear programming (MILP) to schedule the NSWPP activities efficiently. MSO uses heuristic priority rules to decompose the activities from the main project into subgroups. The subgroups are then iteratively optimized using a time-indexed discrete-time MILP formulation. The results from the comparative tests conducted show that MSO is computationally efficient and produces near-optimal solutions. Also, a comparative study of the solutions generated by MSO proves that the proposed method outperforms state-of-the-art heuristics.