title: Politicizing the White Coat: Physician Activism and Asylum Seeker Healthcare  in Canada, Germany and England

title: Politicizing the White Coat:

contributor:
Bird, Karen
Political Science

subject:
refugees
healthcare
immigration
social movements

abstract:
The Canadian identity narrative typically centres on two features: universal healthcare and a longstanding tradition of welcoming newcomers – in particular, refugees. In 2012, this mythology was troubled when, without warning, asylum seekers’ healthcare access was dramatically limited. In an equally dramatic fashion, physicians and the greater healthcare community took to the streets, occupied offices, and interrupted politicians in an effort to restore refugee claimants’ access to healthcare. While this physician-led response was unprecedented in Canada, physicians had previously rallied in a similar fashion in two other universal healthcare countries: England (2003) and Germany (1993). Across all three cases, formidable physician responses emerged following efforts to remove or restrict asylum seekers’ healthcare access.
   In Canada, asylum seeker health restrictions, and the successful social movement they spurred were unexpected entirely. In England, attempts to restrict access are expected, but the government’s failure to implement wide-scale reforms are not. Finally, in Germany, restrictions are potentially expected, but one also expects the decades-long advocacy movement to have created national-level change; instead, ripples of impact are seen unevenly across the country. This prompts two central questions: what conditions are necessary for a national government to successfully implement restrictions on asylum seeker healthcare? And, what conditions will support physician-led social movements’ efforts to reverse these legislative changes?
   This thesis examines these two questions in a three-case comparison of Canada, England and Germany. Drawing on over 60 qualitative interviews with physicians, policymakers, and politicians, this study takes an ecological approach to understanding what factors facilitate reform, and what factors shape advocacy movements. In particular, this study identifies factors at each of the macro, meso, and micro-levels of analysis to map advocacy movements against their institutional contexts and political climates. By examining social movements as creatures of their policy and ideational contexts, this thesis provides a holistic examination of the people, organizations, and institutions that shape asylum seeker healthcare. This study identifies features of movements and contexts that will impact advocacy efforts; these findings are of use to scholars of social movements but also everyday advocates and persons driving change in asylum seeker social policy.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Sikel Political Organization to the End of the Fifth Century

title: The Sikels to the End of the Fifth Century

contributor:
Pope, Spencer
Classics

subject:
Sicily
Classical Archaeology
Antiquity
the Ancient Mediterranean

abstract:
This thesis investigates the evidence for Sikel culture in central Sicily from the Bronze Age to the end of the fifth century. Previous scholarship on this period of Sicilian history has focused on the Greeks and their presence on the island; this thesis aims to bring to light the role that the Sikels played in the events of the early Classical period. The present work considers the interdisciplinary body of evidence for the Sikels before, during and after Ducetius’ συντέλεια in the mid-fifth century.
The first chapter examines the archaeological evidence for the Sikels before Ducetius’ rise to power in 466 BCE. Continuities in Sikel burial practice and communal dining can be traced from the Bronze Age into the fifth century, and are significant in identifying and understanding the nature of Sikel presence at specific sites in the Sicilian interior.
The next chapter focuses on Ducetius’ συντέλεια (466-440 BCE) and investigates the historical accounts of Sicily in the fifth century in conjunction with the archaeological evidence for the Sikels. Ducetius is considered in the context of the rise and fall of the Greek tyrants on the island in the first half of the fifth century. In addition, archaeological evidence at the site of Palikè, an important Sikel religious sanctuary, is examined, in order to highlight the continuity in Sikel religious practices during Ducetius’ remodeling of the sanctuary. This chapter then culminates with a discussion on the geographical extent of the Sikel territory to the death of Ducetius.
Finally, the last chapter examines the historical and epigraphic evidence for the Sikels from Ducetius’ death to the rise of Dionysius I in 405. The Sikels remained important actors in Sicilian history in this period, and were considered by the Greeks and Carthaginians to be critical allies, as different groups vied for control on the island.

abstract: Thesis

abstract: Master of Arts (MA)

abstract: This thesis considers the political organization and territory of the Sikel people of eastern Sicily from the Archaic period to the end of the fifth century BCE. In 466 BCE, a figure by the name of Ducetius arose and united the Sikels into a federation, or συντέλεια, against the Greek neighbours who inhabited the coasts to the east and south. Of particular consideration in this thesis is continuity and change in Sikel culture and political organization before, during and after Ducetius’ συντέλεια. The aim of this investigation is to demonstrate that the Sikel territory remained a discrete entity from the Greek city-states, and that the Sikels living within this territory both adopted aspects of Greek culture and maintained Sikel practices, into the reign of Dionysius I of Syracuse at the end of the fifth century.


title: The Feasibility of Whole-body In Vivo X-ray Fluorescence of Lead in Bone in Mice

contributor: Radiation Sciences (Medical Physics/Radiation Biology)

subject:
XRF
X-ray fluorescence
Lead
Lead in bone
Minimum detection limit
Mouse-mimicking phantoms
Mean bone Pb level

abstract: Previous studies have shown an association between Pb exposure and intelligence quotient (IQ). Up until now, there is a lack of technology and methodology to assess the effects of long-term Pb exposure (such as de-myelination) in brain in-vivo. So we are developing a mouse model that will allow us to assess in vivo Pb in bone and brain structure and myelination using magnetic resonance imaging (MRI). In this project, we will discuss the feasibility of an in vivo x-ray fluorescence (XRF) system for the Pb measurement in the skeleton of whole mice. A review of literature is conducted in chapter 1. Health impacts of lead, measurement of lead, pre-existing bone Pb phantoms and mouse model selection are explained thoroughly. In chapter 2, calibration and minimum detection limits (MDLs) for the XRF measurements are documented. Calibration was performed using Plaster of Paris phantoms mimicking human bone doped with Pb concentrations ranging from 0 to 100 ppm. Detection limits for the pre-existing bone Pb phantoms were found to be 1.52 μg Pb/g plaster for 1-hour measurement. For 2 strains of Pb free mice (CD-1 and C57BL/6J), which had skull and hind facing detectors respectively, MDLs of 5.66 – 7.78 μg Pb/g and 6.69 – 8.50 μg Pb/g were determined for 3-hour measurement. This detectability of MDLs by the XRF system encourages us to proceed to measure mouse-mimicking phantoms. In order to evaluate the feasibility of a 109Cd XRF system for the Pb measurement in the skeleton of whole mice, mouse-mimicking phantoms were made and measured. The effect of variations in Pb distribution across the mouse and the applicability of the normalization in mice are discussed in chapter 3. To sum up, our system can measure Pb in whole mice in vivo at the levels of Pb in bone that are anticipated in brain de-myelination studies. Our results indicate that if multiple orientations (rotated) are measured in mice, the mean bone Pb level in whole mice will be determined accurately.

abstract: Thesis

abstract: Master of Science (MSc)


title: Feeling the Road: Multisensory Processing in Simulated Driving

contributor:
Shedden, Judith M.
Psychology

subject:
Multisensory Processing
Driving Simulator
Visual-Vestibular Integration
Visual-Auditory Integration

abstract: Studies that explore integration of visual, auditory or vestibular cues, are derived from stimulus detection and discrimination tasks in which stimuli are selective and controlled. Multisensory processing is not as well understood in more dynamic and realistic tasks such as driving. As visual information is the dominant source of information when controlling a vehicle, we were interested in the contribution of auditory and physical motion (vestibular and proprioceptive) information to vehicle control. The simulated environment consisted of a straight, two-lane road and the task was to drive in the center of the right lane and maintain a constant speed, slowing down for occasional speed bumps. We examined differences in driving performance under four sets of sensory cues: visual only, visual and auditory, visual and physical motion, and visual, auditory and physical motion. The quality of visual information was manipulated across two experiments. In Experiment 1, participants drove in daylight in sunny weather, providing excellent visual information. In Experiment 2, visual information was compromised by providing dark and stormy weather conditions. In both experiments we observed an advantage of multisensory information, an effect that was enhanced when visual information was compromised. Auditory cues were especially effective in improving driver control.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Multisensory processing (combining information from different sensory systems) is not well understood in realistic tasks such as driving. A simulated environment consisted of a straight, two-lane road was used for this study. The task was to drive in the center of the right lane and maintain a constant speed, slowing down for occasional speed bumps. We examined differences in driving performance under four sets of sensory cues: visual only, visual and auditory, visual and physical motion, and visual, auditory and physical motion. The visual information was manipulated across two experiments: first, participants drove in daylight in sunny weather, providing excellent visual information. Next, visual information was compromised by providing dark and stormy weather conditions. In both experiments we observed an advantage of multisensory information, an effect that was enhanced when visual information was compromised. Auditory cues were especially effective in improving driver control.


title: Thermoelectric Performance of Spark Plasma Sintered Co4Ge6Te6 Ternary Skutterudite and Doped SnTe Compounds

contributor:
Mozharivskyj, Yurij
Chemistry and Chemical Biology

subject:
Thermoelectric
Inorganic Material
Semiconductor
Energy

abstract:
A large amount of thermal energy is being wasted every day from domestic and industrial usages such as home appliance and heating system, vehicle exhaust and many industrial processes including melting, refining, annealing, and forming. However, there were a significant impact on the environment and economy if one could recover this waste energy and convert it to useful energy for the industrial or domestic consumptions. Thermoelectric (TE) generators as a direct heat conversion technology are a promising approach to scavenge waste heat and to significantly improve the overall energy efficiency of energy-intensive industries. However, the energy conversion efficiency of current thermoelectric materials is insufficient to make the technology economically viable. In this study, we investigated two potential thermoelectric materials, Co4Ge6Te6 skutterudite and SnTe, in order to enhance their TE properties.
Among all the state-of-the-art thermoelectric materials, skutterudites have been found to be brilliant candidates for thermoelectric applications due to their remarkable electronic transport properties. Ternary skutterudites are isostructural to their binary analogues with the advantage of lower lattice thermal conductivity than the unfilled binary skutterudites due to the increased structural complexity. Here, in order to further understand this system and its thermoelectric properties, polycrystalline Co4Ge6Te6 (CGT) was investigated as a model ternary skutterudite material. Spark plasma sintering (SPS) was used to solidify the samples. The microstructure, phase stability, compositional homogeneity and thermoelectric behaviour of the sintered samples under SPS condition were investigated. We found that SPS can form different crystalline phases due to the migration of highly mobile species inside the sample due to the applied electrical current. There were significant inconsistencies in the physical properties of the samples. We also realized that Sb-doped CGT samples yielded to the highest power factor reported for the CGT derivatives so far.
Moreover, recent environmental regulations have restricted the use of lead in many real-life applications including thermoelectric power generators. SnTe as a lead-free chalcogenide-based material can be a promising TE candidate to attain high thermoelectric performance. However, the main issue with SnTe is high intrinsic Sn vacancies leading to low Seebeck coefficient and high electrical thermal conductivity. In this regard, we aimed to introduce different metallic species into the SnTe samples (Sn1-xAxTe, A= Co, Ni, Zn, Ge, and x = 0.01, 0.03, 0.05) to enhance their TE performance. Each metallic species presented different solubility and microstructural impact on the main SnTe phase and therefore caused variations in physical properties. Ge-doped samples had more uniform microstructures with a very few Ge-rich regions, which implies higher Ge solubility in SnTe matrix. The existence of impurity phases in the Co-, Ni-, Zn-doped samples yields lower lattice thermal conductivities without deterioration in charge transport properties, leading to higher ZT values relative to the pristine SnTe sample. Microhardness of the doped samples is also improved due to the crack growth suppression and crack branching.

abstract: Thesis

abstract: Master of Science (MSc)


title: DSAP: Data Sharing Agreement Privacy Ontology

title: Privacy Ontology for Health Data Sharing in Research

contributor:
Samavi, Reza
eHealth

subject:
Privacy
Health Research
Medical Research
Ontology
Data Sharing
Data Sharing Agreements
Linked Data
Privacy Audit Log
Health Information Sharing
Health Information

abstract: Medical researchers utilize data sharing agreements (DSA) to communicate privacy policies that govern the treatment of data in their collaboration. Expression of privacy policies in DSAs have been achieved through the use of natural and policy languages. However, ambiguity in natural language and rigidness in policy languages make them unsuitable for use in collaborative medical research. Our goal is to develop an unambiguous and flexible form of expression of privacy policies for collaborative medical research. In this thesis, we developed a DSA Privacy Ontology to express privacy policies in medical research. Our ontology was designed with hierarchy structure, lightweight in expressivity, closed world assumption in interpretation, and the reuse of other ontologies. The design allows our ontology to be flexible and extensible. Being flexible allows our ontology to express different types of privacy policies. Being extensible allows our ontology to be mapped to other linkable ontologies without the need to change our existing ontology. We demonstrate that our ontology is capable of supporting the DSA in a collaborative research data sharing scenario through providing the appropriate vocabulary and structure to log privacy events in a linked data based audit log. Furthermore, through querying the audit log, we can answer privacy competency questions relevant to medical researchers.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Cultural Life of Extinction in Post-Darwinian Print Culture

contributor:
Kehler, Grace
English and Cultural Studies

subject: Extinction, Evolution, Victorian Print Culture, Darwin, Animal Studies, Proto-ecological, Periodicals, Meat Trade, Scientific Romance, Wells, Shiel, Posthumanism

abstract: This thesis is an interdisciplinary study that traces colloquial engagements with extinction in Victorian print culture (1859-1901). Extinction’s broad cultural life demonstrates the extent that scientific and cultural topics intricately entangled within Victorian print networks. Non-specialist Britons absorbed and transmitted evolutionary (particularly, Darwinian) knowledges within public discursive spaces instead of exclusively institutional settings. Class stratification did not bar non-specialists from absorbing and perpetuating cultural conversations about collapses, conservationism, and overconsumption. My project thus seeks to amend the critical discourse that assumes that Victorians passively accepted impending catastrophes or paid scant attention to extinction pressures. I recover multiple subjects formerly hidden in the vast Victorian archives: obscure non-specialists of the working and middle classes, obscurer animals cohabiting the Victorian’s everyday spaces, and the popular (and in some cases, underappreciated) literary texts demonstrating how Victorians circulated extinction discourses. Chapters One and Two explore the non-literary side of print culture, recovering widely disseminated but now largely unknown periodical artifacts (the domain of Punch, The Times, or Funny Folks). Chapter One focuses on cultural reactions to collapses of England’s domestic birds. Chapter Two traces the economized conservationism of the Brooke Brothers, popular game and meat traders. In both chapters, I determine how experienced evolutionary knowledges revealed the human-caused tenuousness of a trans-species milieu. Chapters Three and Four concentrate on scientific romances originally serialized in periodicals, including my key literary case studies, H.G. Wells’s The Time Machine (1895) and M.P. Shiel’s The Purple Cloud (1901). Musing on extinction led to a mindset that acknowledged entanglement with nonhuman others as an ethical imperative. However, some case studies demonstrate a profound ambivalence toward the human’s self-extinction, resulting in a complicated engagement with future forms that often re-privileges the human from within a radical ontology.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This study examines how Victorians absorbed and communicated ideas about extinction, especially as informed by evolutionary theory. Throughout Victorian newspapers, journals, and literature, extinction was adopted for disparate uses. A culturally, economically, and philosophically muddied topic, extinction provoked reconsiderations of the natural world and humankind’s place within it. I begin by examining advertisements, articles, and illustrations from popular newsprint and periodical sources that communicated fears about the extinction of common animals and concerns about controlling or maintaining bird and game populations in everyday Victorian life. When I turn my attention to my literary case studies, H.G. Wells’s The Time Machine and M.P. Shiel’s The Purple Cloud, I analyze the period’s preoccupation with the human’s future forms, looking at both posthuman evolutionary outcomes and the experience of becoming-nonhuman itself. Significantly, this project recovers underappreciated Victorians and texts, filling important gaps in Victorian periodical studies and animal studies.


title: (HOW) SHOULD I BE DOING THIS? PARTNERING IN RESEARCH WITH A CONSUMER SURVIVOR INITIATIVE AS AN OUTSIDER MASTER'S STUDENT

contributor:
Fudge Schormans, Ann
Social Work

subject:
participatory action research
community based participatory research
master's student
outsider
thesis
social work
narrative inquiry
storytelling

abstract: Participatory action research (PAR) methodologies attract researchers both because they open up space to apply the values and principles associated with social justice and because they have the potential to deepen our understanding of an issue by giving us the opportunity to explore contexts and processes through people's experiences. This allows for new insights to emerge and relevant solutions to be discovered and implemented through emancipatory practices. However, choosing to do this type of research for a thesis as a master's of social work student without lived or research experience complicates an already complex endeavor and raises many dilemmas, questions and challenges. Reflecting on my experience of working with a peer-led community organization in Southern Ontario that provides services for people who have experienced mental health or substance use challenges and have interacted with the mental health system, this thesis will explore my journey of joining a research team that set out to use PAR to better understand peer support. Using a narrative inquiry approach, I will explore the tensions that occurred throughout the process of attempting PAR with a community agency within the university framework of completing a thesis. In the spirit of PAR and its intention to disrupt dominant approaches to research processes, I will use an alternative, storytelling format in order to best illustrate my circumstances, perspectives and the difficulties I faced as an outsider, student, university researcher trying to follow PAR principles. The lessons I learned will also be provided in an effort to make this type of undertaking easier for future students. Overall, I learned that we need to find ways to bridge and support the two cultures of graduate students and community groups in working together in PAR.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: A Machine-checked Categorial Formalisation of Term Graph Rewriting with Semantics Preservation

contributor:
Kahl, Wolfram
Computing and Software

abstract:
Term graph rewriting is important as "conceptual implementation" of the execution of functional programs, and of data-flow optimisations in compilers. Since term graphs were introduced into the literature, various flavours of term graph rewriting have been investigated mainly as implementation of term rewriting. One way to define term graph rewriting rule application is via the well-established and intuitively accessible double-pushout (DPO) approach. It uses the abstraction of category theory to define matching and replacement on a black-box level through basic categorial theoretic concepts like pushouts. However,
the semantics preservation of DPO term graph rewriting, to our knowledge, has never been formalised before. In this thesis, we show the gs-monoidal categories proposed by Andrea Corradini and Fabio Gadducci serves not only as a category-theoretic interface for programming "on top of" term graphs
with sequential and parallel composition, but also as the necessary link relating our formalisation of DPO term graph rewriting to the categorial description for program semantics.
One achievement of our work is the representation of term graphs employed by the dependently-typed programming language Agda on a suitable level of abstraction from the concrete choice of set representation for graph nodes and edges through the novel category-theoretic abstraction of dependent objects.
Another result is the formalisation of the functor from gs-monoidal category of term graphs to any gs-monoidal categories which enables us to obtain the semantics of term graphs.
Finally, we present a new result proving the semantics preservation for such DPO-based term graph rewriting.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: QUANTITATIVE ANALYSIS OF MICROSTRAIN PARTITIONING AND DAMAGE IN A COMMERCIAL QP980 AUTOMOTIVE STEEL

contributor:
Wilkinson, David S.
Materials Science and Engineering

subject:
Microstructural damage
Microstrain partitioning
QP980 steel

abstract:
Over the past decade, environmental concerns and safety regulation have led to increasing demand for vehicles with higher passenger safety and fuel economy. This has spurred intensive research on advanced high strength steels (AHSS). The quench and partitioning (Q&P) heat treatment is a novel approach that has led to development of one group of third generation AHSS alloys. In recent years most of the studies on the Q&P process were dedicated to the effect of the heat treatment parameters on microstructural evolution and mechanical properties. However, micromechanical deformation behavior of constituent phases and damage evolution in Q&P steels are not fully understood.  In this study, damage micromechanisms in a commercial QP980 were investigated with the aid of in-situ tensile tests under a scanning electron microscope (SEM) followed by local strain mapping using microscopic digital image correlation (µ-DIC) analysis so as to quantify the microstructural deformation of constituent phases. Nano-hardness measurements were conducted to correlate the amount of plastic deformation of each phases to its strength. Ex-situ tensile tests coupled with electron back scattered diffraction (EBSD) and X-ray diffraction (XRD) were conducted to study the influence of transformation induced plasticity (TRIP) of the retained austenite phase on microstructural damage and deformation.
It was found that average local true strain in ferrite was approximately two times and three times greater than that of martensite and blocky retained austenite respectively, which was with the good agreement with nano-hardness measurements showing that retained austenite blocks was three times and two times harder than martensite and ferrite respectively. Damage in both ferrite and martensite starts at the same total strain; however, damage growth is faster in martensite leading to the formation of large cavities. The average local true strain ratio of ferrite to martensite decreases after total true strains higher than 0.1 and the reduction is more pronounced in regions with higher martensite volume fraction. EBSD results showed that at total true strain of 0.07 some of the retained austenite blocks located at the ferrite and martensite interfaces were almost fully transformed to martensite. According to XRD results at the point of necking 57% of retained austenite transformed to martensite. There is evidence of brittle cracking of large blocky retained austenite in regions with strain localization starting at relatively low strains but appear to have little impact on the final failure process. The good deformation ability of QP980 is attributed primarily to co-deformation of ferrite and martensite and secondarily to the TRIP effect.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: LATE HOLOCENE PALEOCLIMATIC RECORDS FROM LAKE PAC CHEN AND CARWASH CENOTE, QUINTANA ROO, MEXICO

contributor:
Reinhardt, Eduard
Earth and Environmental Sciences

subject:
coastal karst aquifers
salinity
Holocene sea-level rise
Yucatan
paleohydrology
paleoclimatology

abstract:
The disintegration of the Classic Maya throughout the Terminal Classic (750-900 C.E.) is a complex loss of human population that has presented many questions about climate change and its impact on humanity.  With droughts proposed as a prominent cause, understanding the quality and availability of groundwater resources at the time is pivotal to further determining the spatial and temporal distributions of population deterioration. The Yucatan aquifer consists of karstic cave systems, with a small number of inland lakes, which have previously been termed closed to the aquifer. It is important to understand how both of these types of water bodies react to long- and short-term forcing mechanisms such drying climate, sea-level rise and precipitation events. Using a variety of spatial and temporal records to determine aquifer evolution, changes and connectivity throughout the Holocene it will further understanding of how the aquifer reacts to changes in climate and the implications this may have had on the Classic Maya.
Four sediment cores from Pac Chen Lake and two sediment cores from Carwash Cenote were collected to investigate Holocene paleoclimatic trends on the Yucatan Peninsula in Mexico. Records of past climate, groundwater conditions and flooding history at both sites were determined through microfossil and micro X-Ray fluorescence data. In Pac Chen Lake, elevation and timing of flooding of the lake coincided with sea-level rise. Using Ti, Fe and K records to determine wet vs dry conditions, dry periods through the terminal classic coincided with other paleoclimate records, but with no evidence of draw-down within the lake. Both of these observations imply connection of the lake to the aquifer. The Cl record from Carwash was used alongside a core from the Yax Chen cave system to observe spatial and temporal potability of the aquifer. An overall freshening trend in the coastal groundwater occurred throughout the Holocene. The largest amount of this freshening transpired through the Terminal Classic. At this time, populations inland were experiencing deterioration, while coastal populations along the coast continued to survive. Comparing Cl records at various depths and distances from the coast proved that Cl is impacted by proximity to the halocline.

abstract: Thesis

abstract: Master of Science (MSc)


title: Pore-water Feedbacks and Resilience to Decay in Peat-filled Bedrock Depressions of the Canadian Shield

contributor:
Waddington, James Michael
Geography and Earth Sciences

subject:
ecohydrology
isotope hydrology
feedbacks
peatlands

abstract: M.Sc Thesis

abstract: Northern peatlands are able to persist on the landscape and continue to accumulate carbon in the long-term thanks to a suite of ecohydrological feedbacks that confer resilience to disturbance such as the drier and warmer conditions associated with climate change. One feedback of particular interest operates between peat pore-water residence time and chemistry, whereby changes in hydraulic structure with depth restrict turnover in deeper layers, allowing decay end-products to accumulate and thermodynamically suppress decomposition. In this way, the burial of peat facilitates its continued recalcitrance. While this feedback has been observed in more extensive northern peatlands, at least on the side of carbon dynamics and geochemistry, there has been no observational study of profiles of pore-water residence time nor has it been assessed in smaller peat-forming systems. The peat-filled bedrock depressions of the Canadian Shield offered a unique opportunity to study this feedback in systems where primary peat formation occurs under geological constraints on growth in the form of the largely impermeable bedrock. These systems play important hydrological, biogeochemical and ecological roles on the landscape. Understanding their resilience on the landscape may reveal key insights into their evolution and their response to disturbance, which is increasing in the eastern Georgian Bay region. These systems have previously exhibited a hydrological feedback between water table depth and specific yield that varies with depression size. To assess the hydraulic structure that constrains pore-water transport to support continued recalcitrance, profiles of hydrophysical properties and pore-water residence time in four deep (>0.4 m mean depth) and five intermediate (<0.4 m) depressions. Hydraulic structure varied by depression size and depth in the profile, with very low hydraulic conductivities measured in the catotelms of deep sites. The two classes of depressions exhibited distinct hydrology, in the form of dampened water table fluctuations and hydraulic gradients in the deeper sites. Stable isotope analysis of δ2H and δ18O was used to estimate relative pore-water residence times using the simplified inverse transit time proxy (ITTP) for samples collected from May-August 2017. These estimates were observed to have similar controls to hydraulic structure and a close relationship with depth-averaged conductivity on a whole-site basis. While it was hypothesized that the catotelms of deeper depressions would have less pore-water turnover than that of shallower depressions, the ITTP was only able to differentiate between catotelm-acrotelm and deep-intermediate individually. The relative residence time of pore-water in deep catotelms based on δ2H was longer than in intermediate catotelms, but not significantly. These results broadly supported previous pore-water residence time work despite the likely ubiquitous promotion of turnover in the wetter-than-average study period. Carbon accumulation was quantified from extracted peat cores and pore-water chemistry was assessed as dissolved organic matter (DOM) quality using fluorescence spectrometry of monthly pore-water samples. Fluorescence and absorption indices varied by the same depression characteristics as hydraulic structure of site size and depth, but only the humification index exhibited significant temporal variation. Characterization of pore-water DOM was somewhat unclear across the seven indices calculated, although the DOM of intermediate sites appeared to be less humified, more recently produced and autochthonous in nature compared to deep sites Carbon accumulation was predominantly driven by the waterlogged, relatively stable carbon stored deep in the catotelm. Total carbon accumulated in the profile, and even more so the amount stored in the catotelm, were strongly related to depression depth. The thickness and carbon storage of the acrotelm was insensitive to depression morphology, with some intermediate sites being considered all acrotelm based on their water table behaviour. Overall, deeper peat-filled depressions showed stronger signs of the pore-water residence time-chemistry feedback, suggesting the carbon stored in their deep peat layers is more resilient to decay, by way of less conductive deep peat, longer relative pore-water residence times and more humified, less biologically active DOM. In order to comprehensively assess this feedback, longer stable isotope records are essential to ensure robust residence time estimates through differing moisture conditions, and a greater variety of depression sizes may allow for elucidation of threshold depression sizes where hydrological behaviours diverge. This study, at least on a categorical basis, can be used to inform conservation strategies of the relative vulnerability of these important reptile habitats and carbon stores, as well as guide restoration efforts to construct sufficiently deep, resilient systems.

abstract: Thesis

abstract: Master of Science (MSc)


title: Colonial continuities and nation-building within social work practice and a demand for critical whiteness studies

contributor:
Joseph, Ameil
Social Work

subject:
social work
reconciliation
nation-building
harm reduction
retreatism
settler subjectivity
gatekeeping
critical whiteness studies
Canada
colonial project
colonial continuities
white supremacy

abstract: Raven Sinclair (2004) locates the social worker at the heart of the colonial project, carrying out violent and assimilative government policy in Canada (p.50). Social work's connections to colonialism have been consciously and some would say “innocently” mutually dependent (Rossiter, 2001; Heron, 2007). Social work responses over time have been criticized for being non-performative (Ahmed, 2004), upholding institutional power (Bunjun, 2014) and ignoring ongoing colonialism (Lawrence & Dua, 2005). This study explores how self-identified white social work managers and directors reflect on and understand their roles in relation to reconciliation policy. It looks at the way discourse interrupts or maintains ruling relations including white supremacy and other colonial continuities (Heron, 2007). “In order to avoid further complicity, in assimilative and colonial practices, non-indigenous helpers must develop a clear understanding of their privilege and of their professions’ complicity in past and present colonial practices embedded in their practice”(Baskin, 2016). Through qualitative interviewing the study used critical whiteness studies and critical discourse analysis with the concept of relational validity in mind (Tuck & Yang, 2018). “What is valid in research is that which resonates with people’s lives and informs their power to make change” (Tuck & Yang, 2018, p.xiii). The findings suggest that participants orientation to reconciliation in the workplace, is controlled and continually reinforced through state discourses (neoliberal, neocolonial, reconciliation). Interestingly, the findings also suggest that participants may be de-contextualizing AOP discourses to neutralize and depoliticize their professional roles in the colonial project, as well as to rationalize their reluctance to take action. This suggests current approaches are not adequate to address colonial continuities in an era of reconciliation.

abstract: Thesis

abstract: Master of Social Work (MSW)


title: THE NIGHTMARE LIFE-IN-DEATH: ARTISTIC INTENTIONALISM IN MARY SHELLEY’S FRANKENSTEIN AND ANNE RICE’S INTERVIEW WITH THE VAMPIRE

contributor:
Grisé, Cathy
Humanities

abstract: This thesis examines the gendered language and reliance upon birth metaphors in anti-intentionalist rhetoric as explicated in Wimsatt and Beardsley’s "Intentional Fallacy" and Barthes' “Death of the Author.” Reading Anne Rice's Interview with the Vampire as a reworking of the themes of creative anxieties, power, and responsibilities presented in Mary Shelley's Frankenstein, it posits the novels' respective secondary narrators—Louis and Victor, both of whom are responsible for creating a supernatural life—as creators in conversation with their public. I argue that the differing levels of credibility and interpretive authority granted to Victor and Louis is a product of their levels of access to masculine interpretive authority. The project begins with an examination of the ways in which the anti-intentionalist's demand for authorial silence post-publication affects popular discourse surrounding the speech and images of celebrity authors, including Rice and Shelley, and asks questions about the implications of anti-intentionalist theories for readers’ creations of selves.

abstract: Thesis

abstract: Master of Arts (MA)


title: DEVELOPMENT OF AN ADVANCED GENETIC TOOLBOX TO ENABLE GENOME SCALE ENGINEERING IN SINORHIZOBIUM MELILOTI

contributor:
Finan, Turlough
Biology

subject:
Synthetic biology
Genetic engineering
high G+C content
Sinorhizobium meliloti
multi-host shuttle vector
site-specific recombination
biotechnology
S. cerevisiae
P. tricornutum

abstract: Synthetic biology has ushered in a new age of molecular biology with the aim towards practical developments in disciplines ranging from medicine, agriculture, and industry. Presently, it remains difficult to manipulate the genomes of many organisms due to lack of genetic tools. These problems can be circumvented by cloning large fragments of DNA into strains where many genetic tools are in place, such as Saccharomyces cerevisiae. However, this organism is unable to directly transfer cloned DNA to other organisms and is unable to stably maintain DNA with a G+C content >40%. Many organisms relevant in biotechnology often have G+C content DNA >60%, and therefore are difficult to engineer. Here, the soil bacteria Sinorhizobium meliloti was chosen as a host strain to clone and manipulate large fragments of high G+C content DNA. S. meliloti is a Gram-negativeα-proteobacteria that forms symbiotic relationships with legumes to fix nitrogen. It has a multi-partite genome with a G+C content of 62.7% that includes a chromosome (3.65 Mb), the pSymA (1.35 Mb), and pSymB (1.68 Mb) replicons. A restriction endonuclease hsdR mutant strain lacking pSymA and pSymB was created and used in this study. Multi-host shuttle (MHS) vectors were constructed that allow for direct transfer and maintenance of DNA in E. coli, S. cerevisiae, and P. tricornutum. Characterization of strains was conducted to determine transduction, conjugation, and transformation frequencies, as well as stability of MHS plasmids. Furthermore, a proof-of-concept experiment was conducted to clone large plasmids (70-205 kb) with G+C content >58% via site-specific recombination at a landing pad in the MHS vector, which was then verified using colony PCR. This work demonstrates the usefulness of S. meliloti containing a MHS vector for cloning of large fragments with high G+C content DNA, a technology that may be used for several applications in both applied and basic research.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Synthetic biology is an emerging field that incorporates principles of molecular biology and engineering for the design and construction of biological systems for application in medicine, agriculture, and industry. Presently, it remains difficult to modify genomes of several organisms due to lack of available techniques. Yeast is currently used for the modification of large DNA pieces, however it is unable to transfer and maintain modified DNA with high G+C content. Here, the bacteria Sinorhizobium meliloti was used as a host organism to conduct genetic engineering due to its ability to maintain large DNA pieces with a high G+C content. Characterization experiments were conducted to assess the efficiency of this organism for this task. Using this strain, a proof-of-concept experiment to demonstrate the uptake and maintenance of large, high G+C DNA pieces was completed. This technology may be useful in biotechnology applications for engineering of large DNA pieces from industrially relevant organisms.


title: An Integrative Study of Reproduction, Feeding and Behavioural Activity in Giant Transgenic Growth Hormone Mice

title: Impact of 24H Light on Physiology of Transgenic GH Mice

contributor:
Rollo, C. D.
Biology

subject:
integrative study
reproduction
feed
behaviour
transgenic growth hormone
mice

abstract:
"Supermice" (TRrGH mice) contain multiple copies of rat growth hormone genes incorporated into a single chromosome. This results in double normal growth rates reaching adult body sizes twice that of normal mice. To determine how exposure to constant light (LL) affects various physiological processes, reproduction, feeding, and behaviour were examined in LL-reared TRrGH mice. Fertility, organ allometries, feeding rates, behavioural time budgets, and circadian feeding and sleep rhythms were compared for both LL and standard 12h dark: 12h light (LD).
Both TRrGH and normal females exhibited a significant decrease in fertility in LL. On a mass-specific basis, TRrGH females showed increased combined ovary mass and a reduction in thymus and heart size in LL. TRrGH males demonstrated increased testes mass in LL. When adrenal size was compared between males and females, both TRrGH and normal females exhibited larger adrenals than their male counterparts in both light treatments. The fertility decrease observed in LL may have been associated with reduced food intake. LL-reared TRrGH females ate less than those in LD, although significantly more than TRrGH males in both LL and LD. When compared to normal mice, both sexes of TRrGH mice ate less in both photoperiods. The feeding rates of transgenic GLUT -4 mice were also examined. GLUT -4 mice contain double the amount of insulin responsive GLUT -4 glucose transporters which results in an increased blood glucose clearance rate. These mice, like TRrGH mice, ate less than normals, although a different age-related feeding pattern was observed. TRrGH mice in LL are behaviourally more lethargic than those reared in LD, and spend less time feeding and drinking. Circadian feeding and sleep patterns were shifted in LL by approximately 12 hours, and exhibited reduced peak amplitudes. Ultradian patterns appeared to survive the breakdown of circadian organization. TRrGH mice demonstrate a hormonal imbalance due to the excess allocation of energy into growth. It appears that, in LL, hormonal systems are further altered resulting in an increase in reproductive impairment associated with reduced feeding. One of these altered hormones may be estrogen. Hormones involved in hypothalamic-pituitary-adrenal axis (stress axis) are also implicated. It is concluded that photoperiod is important in regulating physiological processes, and TRrGH mice are more susceptible to environmental alterations due to their altered endocrinological state.

abstract: Thesis

abstract: Master of Science (MS)


title: High-resolution facies analysis and regional correlation of the Upper Cretaceous Juana Lopez Member of the Mancos Shale, New Mexico

contributor:
Bhattacharya, Janok
Geography and Earth Sciences

subject:
Sedimentology
Stratigraphy
Mancos Shale
Heterolithic
Depositional Model
Facies Analysis

abstract: Fine-grained clastic sediments make up the gross lithology in interior basins of ancient epicontinental seas, such as the Cretaceous Western Interior Seaway. This study provides a high-resolution thin-bedded facies analysis and regional correlations to determine how the heterolithic units of the Juana Lopez Member of the Mancos Shale were transported and deposited in the San Juan Basin. Data for this study was obtained from outcrop observations in eleven measured sections, spanning a distance of 115 kilometers. Eleven facies are observed, four sequences and eleven parasequence sets are identified. A depositional model is determined through the high-resolution facies analysis, which suggests deposition on a proximal to distal mudbelt through multiple processes, including turbidity currents, hypopycnal plumes, wave enhanced sediment gravity flows (WESGFs), storm surges, tides and oceanic currents. Overall, the Juana Lopez is dominated by upward-shoaling parasequence sets, with an increasing number and thickness of sandstone dominated bedsets, suggesting regressive sedimentation with distal expressions of transgression found in two parasequence sets. The source of sediment is determined through 520 paleocurrent measurements and plaeogeographic data, and is determined to be transported by along-shelf currents, dominantly from proximal NE clastic wedges.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Coordination Chemistry of Xenon Trioxide with Oxygen Bases

contributor:
Schrobilgen, Gary
Chemistry

subject:
Noble-gas chemistry
Xenon trioxide
Lewis adducts
Bonding
High oxidation state
Single Crystal X-ray Diffraction

abstract:
This thesis extends our fundamental knowledge in the area of high oxidation state chemistry of xenon trioxide, XeO3. Oxygen coordination to the Xe(VI) atom of XeO3 was observed in its adducts with triphenylphosphine oxide, [(C6H5)3PO]2XeO3, dimethylsulfoxide, [(CH3)2SO]3(XeO3)2, pyridine-N-oxide, (C5H5NO)3(XeO3)2, and acetone, [(CH3)2CO]3XeO3. The crystalline adducts were characterized by low-temperature single-crystal X-ray diffraction and Raman spectroscopy. Unlike solid XeO3, which detonates when mechanically or thermally shocked, the solid [(C6H5)3PO]2XeO3, [(CH3)2SO]3(XeO3)2, and (C5H5NO)3(XeO3)2 adducts are insensitive to mechanical shock, but undergo deflagration when exposed to a flame. Both [(C6H5)3PO]2XeO3 and (C5H5NO)3(XeO3)2 are air-stable at room temperature. The xenon coordination sphere in [(C6H5)3PO]2XeO3 is a distorted square pyramid and provides the first example of a five-coordinate Xe center in a XeO3 adduct. The xenon coordination sphere of the remaining adducts are distorted octahedral comprised of three equivalent Xe---O secondary contacts that are approximately trans to the primary Xe–O bonds of XeO3. Hirshfeld surfaces of XeO3 and (C6H5)3PO in [(C6H5)3PO]2XeO3 show the adduct is well-isolated in its crystal structure and provide a visual representation of the secondary Xe---O bonding in this adduct.
Crown ethers have been known for over 50 years, but no example of a complex between a noble-gas compound and a crown ether or another polydentate ligand had been reported. Xenon trioxide is shown to react with 15-crown-5 to form the kinetically stable (CH2CH2O)5XeO3 adduct which, in marked contrast with solid XeO3, does not detonate when mechanically shocked. The crystal structure shows that the five oxygen atoms of the crown ether are coordinated to the xenon atom of XeO3. The gas-phase Wiberg bond valences and indices and empirical bond valences indicate the Xe---Ocrown bonds are predominantly electrostatic, σ-hole, bonds. Mappings of the electrostatic potential (EP) onto the Hirshfeld surfaces of XeO3 and 15-crown-5 in (CH2CH2O)5XeO3 and a detailed examination of the molecular electrostatic potential surface (MEPS) of XeO3 and (CH2CH2O)5 reveal regions of negative EP on the oxygen atoms of (CH2CH2O)5 and regions of high positive EP on the xenon atom that are also consistent with σ-hole bonding.
Reactions of crown ethers with HF acidified aqueous solutions of XeO3 at room-temperature yielded adducts of 12-crown-4, (CH2CH2O)4XeO3, and 18-crown-6, [(CH2CH2O)6XeO3∙2H2O]2∙HF, whereas slow cooling of a solution of XeO3 with 18-crown-6 in acetone yielded (CH2CH2O)6XeO3∙2H2O. The adducts (CH2CH2O)4XeO3 and (CH2CH2O)6XeO3∙2H2O are shock-insensitive whereas the former adduct is air-stable at room temperature. The low-temperature, single-crystal X-ray structures show the Xe atom of XeO3 coordinated to the oxygen atoms of the crown ether ring. Uncharacteristic xenon coordination numbers exceeding six (including the three primary bonds of XeO3) were observed for all crown ether adducts. Raman spectroscopy frequency shifts are consistent with complex formation and provided evidence for the 2,2,1-cryptand adduct of XeO3. Gas-phase Wiberg bond valences and indices and empirical solid-state bond valences confirmed the electrostatic nature of the Xe---O bonding interactions. Comparisons between the XeO3 and SbF3 18-crown-6, 15-crown-5, and 12-crown-4 complexes are made.
Incorporation of xenon trioxide, XeO3, into inorganic polyatomic salts under ambient conditions has been observed in several mixed xenate salts; K[XeO3XO3] (X = Cl, Br), K2[XeO3SeO4]∙HF, K[(XeO3)nZO3] (Z = I, N), and M2[(XeO3)nCO3]∙xH2O (M = Na, K, Rb, Ba). Raman spectroscopy was used to identify the aforementioned compounds and K[XeO3ClO3], K[XeO3BrO3], K2[XeO3SeO4]∙HF, and Rb2[(XeO3)2CO3]∙2H2O were also characterized by low-temperature, single-crystal X-ray diffraction. The xenon atom of XeO3 is seven coordinate in K[XeO3ClO3] and six coordinate in all other compounds with Xe---O distances that are significantly less than the sum of the Xe and O van der Waals radii. These salts provide examples of XeO3 coordinated to inorganic compounds and may provide insights into the inclusion of xenon oxides in minerals.

abstract: Thesis

abstract: Master of Science (MSc)


title: Effects of Isometric Handgrip Training on Resting Blood Pressure, Heart Rate Variability and Blood Pressure Variability in Older Adults with Hypertension

contributor:
McCartney, Neil
Kinesiology

subject:
isometric handgrip training
resting blood pressure
heart rate variability
blood pressure
blood pressure variability
hypertension

abstract: This study examined the effects of isometric handgrip (IHG) training on resting blood pressure (RBP), heart rate variability (HRV) and blood pressure variability (BPV) in older adults with hypertension. Nine subjects performed four 2-minute IHG contractions at 30% maximal voluntary contraction (MVC) 3 days/week for 10 weeks and 8 subjects served as controls. Power spectral analysis (PSA) of HRV and BPV was used to assess changes in modulation of the autonomic nervous system. After training, there was a marked attenuation in arterial pressure and evidence for a shift in HR.V and BPV sympathovagal balance. There was a reduction in systolic blood pressure (156 ± 9.4 to 137 ± 7.8 mm Hg; p<0.05), diastolic blood pressure (82 ± 9.3 to 75 ± 10.9 mm Hg; N.S), mean arterial pressure (107 ± 8.53 to 96 ± 8.7 mm Hg; p<0.05) and resting heart rate (RHR) (70 ± 14.2 to 68 ± 12.1 beats/min). In addition, PSA of HRV showed a decrease in sympathetic modulation represented by low frequency (LF) area, an increase in parasympathetic modulation represented by high frequency (HF) area (p<0.05) and a decrease in LF:HF area ratio. After training, BPV PSA showed a decrease in systolic blood pressure LF area (p<0.05), an increase in HF area (p<0.05) and decrease in LF:HF area (p<0.05). Similar, but non-significant changes occurred in diastolic BPV. It is concluded that isometric training at a moderate intensity can elicit a hypotensive response and can potentially alter sympathovagal balance of HRV and BPV in older adults with hypertension.

abstract: Thesis

abstract: Master of Science (MS)


title: DETAILED THIN-BEDDED FACIES ANALYSIS OF THE UPPER MANCOS SHALE, NEW MEXICO

subject:
Sedimentology
Geology
Petroleum
Facies Analysis
Cretaceous
Sedimentary Rock Core
Well Log
Depositional Process

abstract: Our understanding of fine-grained sediment regarding the processes in which they are transported and deposited is rapidly evolving. However, developing a depositional model and characterizing the vertical variability within mud-dominated deposits has seldom been done. A 103m Upper Mancos Shale core retrieved from the San Juan Basin, New Mexico was analysed with detailed thin-bedded facies analysis to observe vertical variability in lithology, sedimentary structures, bioturbation intensity, and depositional processes. Lithological variation suggests there are 3 full sequences, 9 system tracts, and 92 parasequences. Facies observed revealed multiple facies successions indicating depositional processes including ignitive turbidite, storms (tempestite), wave enhanced sediment gravity flows (WESGFs), tidal, biogenic reworking, fluid mud, suspension settling, and general bedload transport. Relationships between lithology, bioturbation intensity, sedimentary structures and depositional processes were observed to be interrelated in that energetic processes (i.e., storms, ignitive turbidite) were associated with coarser deposits and low bioturbation intensity; whereas lower energy processes (i.e., biogenic reworking, suspension settling, WESGFs) were associated with finer deposits and relatively higher bioturbation intensities. Furthermore, lithological variability integrated with depositional models indicated temporal changes in environment of deposition across shelf.

abstract: Thesis

abstract: Master of Science (MSc)


title: Labouring Things: Work and the Material World in Mary Leapor's Poetry

contributor:
Zuroski, Eugenia
English and Cultural Studies

subject: eighteenth-century;labouring-class poetry; subjectivity; thing theory; cultural materialism; authorship and authority; taste; social class; espitemology; embodied ways of knowing

abstract: This dissertation explores the life and works of eighteenth-century labouring-class poet Mary Leapor. Leapor’s ability to use everyday objects to write poetry that speaks to important social and cultural transformations of the period is one of the most remarkable and interesting aspects of her poetry, and it sets her apart from other labouring-class writers. Therefore, while this dissertation situates Leapor as a female laborer who writes poetry about the labour she performs, it is more interested in how she uses her poetry about the labour she performs—and particularly how she offers her own version of “thing theory”—in order to speak to a number of problems of which labour is just one. By spotlighting the complex role of objects in Leapor’s poetry, this dissertation shows how she uses those objects to articulate new conceptions of the labouring body’s relationship to authorship and authority, claim authorship as a form of useful labour, and legitimize her own gendered and class-inflected authority as a subject in literary and intellectual discourse. While acknowledging the context of material history, I focus on the ways Leapor uses particular things to rethink the possibilities of labouring-class life, identity, literary expression, and what it might have meant for her to imagine a new kind of human subjectivity that is itself inseparable from the concept of labour. Moreover, Leapor’s work shows that she identifies labouring individuals as part of a community whose experience is heavily organized socially around labour but argues that their lived experience has provided them with a particular identity and perspective. Ultimately, this dissertation works to decenter our own moment in the history of ideas by showing how Leapor was theorizing about forms of situated knowledge over two hundred years before it entered academic discourse in the 20th century through feminist theories of embodied ways of knowing. Leapor’s poetry is not just an object that should be studied through a theoretical lens; it should be understood as a theory of situated knowledge transmitting ideas from its own materially embedded position. Leapor’s poetry lives on as a labouring thing—changing, growing, and theorizing as living humans do—inviting its readers to contemplate the complex components of being an embodied thinker.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: This dissertation focuses on the life and works of Mary Leapor (1722-1746) and builds upon recent interest in the cultural work of particular literary forms by examining the emergence of the labouring-class writer and the rise of a new poetic mode, the labour poem. Existing scholarship has begun to explore the many ways these texts represent class-based and gendered oppression, hardship, and work, and how these writers were able to combine several literary traditions to speak out against adverse conditions. By emphasising the material history of inanimate objects and nonhuman animals found within labouring-class writing, my project seeks to demonstrate how Leapor and other labouring-class writers used their poetry about the labours they performed in order to speak to something more than labour, such as what it means to be a subject in a world that is circumscribed by things like status, class and gender.


title: Intensification of a Lapita fishery at the Hopoate site on Tongatapu, Kingdom of Tonga

contributor:
Cannon, Aubrey
Anthropology

subject: Tonga Fishery Lapita Zooarchaeology

abstract: Zooarchaeological analysis of fish bones is a valuable approach to understand prehistoric diet and resource exploitation in island and coastal settings. This thesis explores fish use at the Hopoate site on Tongatapu by identifying the various taxa which comprised the ichthyoarchaeological assemblage. The analysis focused on recovered materials which date to the earliest period of occupation in Tonga (2850 cal BP). This is the first detailed fishery study from Tongatapu; few have been conducted elsewhere in Tonga. The inhabitants at Hopoate focused fishing on inshore reef fish which is typical of Lapita fisheries. The first inhabitants, the Lapita peoples, benefited from a mixed subsistence economy of plant and marine foods. However, the relative contribution of fish to the Lapita diet was variable across the Pacific Islands. Eighteen fish taxa were identified from a total NISP of 5091. The analysis of fish bones from Hopoate indicated an intensification of the fishery during the mid-Lapita period (2690-2390 cal BP). Past archaeological studies on Tongatapu have recorded a severe decrease in the availability of shellfish from the Fanga ‘Uta Lagoon, following the initial settlement of the island. The increased fishing efforts are possibly related to the decreasing availability of shellfish from the lagoon.

abstract: Thesis

abstract: Master of Arts (MA)

abstract:
This thesis explores fish use at the Hopoate site on Tongatapu, during the earliest periods of
occupation in Tonga. The first inhabitants, the Lapita peoples, benefited from a mixed diet
consisting of plant and marine foods. Archaeological evidence in Tonga and the Pacific Islands
show intensive pressure on numerous native land and sea resources following initial settlement periods. The analysis of fish bones from this study recorded a high abundance of inshore reef fish, typical of most Lapita sites. Following the initial settlement period of the island, fishing efforts increased and a greater amount of fish were harvested. The intensification of the fishery over time may be related to a decline in shellfish harvested from the local lagoon. Overall, the results of this study indicate that the earliest inhabitants were heavily reliant on the local marine resources.


title: Analysis and modifications of two in vivo methods for determining fluorine content in bone

contributor: Radiation Sciences (Medical Physics/Radiation Biology)

subject:
Fluorine
Bone
Neutron Activation Analysis
Nuclear Magnetic Resonance

abstract:
Non-invasive techniques to measure bone fluorine levels in vivo are few and
not well studied. These techniques would prove useful for longitudinal
studies of fluorine accumulation and treatment optimization for patients with
poor bone health. Two measurement techniques were analyzed and
improvements to each technique attempted with bone samples and
bone-mimicking phantoms. The first method analyzed was neutron
activation analysis (NAA), a technique previously studied in our laboratory.
A previous detector setup consisting of nine sodium iodide detectors was
re-tested and a new detector setup consisting of two high-purity germanium
detectors was also tested. The detection limit of the sodium iodide setup was
found to be higher than previously reported by a factor of 4, and the new
high-purity germanium detector setup was found to result in a higher
detection limit by a factor of 5 compared to the sodium iodide setup. The
second method analyzed was nuclear magnetic resonance (NMR). Magic
angle spinning was performed on a human bone sample, and a novel probe
was constructed for future in vivo measurements. MAS NMR measurement
of the human bone sample showed it to have an appropriate chemical shift
and shape consistent with previous research on substances similar to bone.
The constructed probe successfully resonated at the appropriate frequency,
however there were potential contamination problems which prevented a
measurable fluorine signal from being obtained. Both the NAA and NMR
techniques may be optimized further, though with the results obtained, NAA
remains the more sensitive technique for measuring bone fluorine in vivo.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Fluorine is an element which accumulates in bones and teeth. High levels of fluorine have been shown to be unhealthy, causing both dental and skeletal fluorosis. Low levels of fluorine have been shown to reduce dental cavities, however, their effect on bone health is not well understood. Currently, fluorine can be measured in bone samples from either biopsies or cadavers. Having a non-invasive way to measure fluorine concentrations in living humans without the need for surgery would be invaluable. These measurements could be used to optimize treatment for osteoporosis patients or to determine if emergency measures are necessary in cases of high accidental doses to members of the public. Additionally, long-term studies examining fluorine metabolism and bone health could be performed on population groups of interest. For these reasons, two different non-invasive methods for determining fluorine content in bone were analyzed and enhancements to each measurement technique attempted.


title: Modeling of Mechanical Behavior of Structural Masonry

contributor:
Pietruszczak, Stanislaw
Civil Engineering

subject: Numerical Modeling; Structural Masonry;Constitutive Model;Mechanical Behavior; Anisotropy Material;

abstract: Masonry is an orthotropic material that exhibits distinct directional properties due to the existence of mortar joints acting as planes of weakness. Therefore, a constitutive model employed in the numerical analysis should be capable of describing the anisotropic behavior. The main objective of this research is to implement a macroscopic failure criterion which describes the failure conditions in structural masonry. For this purpose, a comprehensive framework is outlined for modelling of the mechanical behaviour of structural masonry. In this framework, the anisotropic material properties are described using the microstructure tensor approach (Pietruszczak and Mroz, 2001). Then, a mathematical formulation defining the conditions at failure is discussed. The formulation contains several material parameters as well as material functions that describe the anisotropic behaviour. The identification procedure for these functions is outlined and is verified using the experimental tests conducted by Page (1983).  Later, an extensive numerical study, including a set of numerical simulations of biaxial compression-tension and biaxial compression tests for different bedding plane orientations, is conducted to evaluate the performance of the proposed macroscopic failure criterion. In the last part of the thesis, some 3D finite element simulations of a shaking table test are performed involving a reduced scale model of four storey masonry building subjected to seismic excitation. A linear dynamic analysis, in which the proposed macroscopic failure criterion is incorporated through the UMAT subroutine, is carried out to assess the plastic admissibility of the stress field. The results including the distribution of the value of the failure function are then compared with the crack pattern in the experimental test.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Assessing the potential for implementation of the Carer-Inclusive and Accommodating Organizations Standard

contributor:
Williams, Allison
Geography and Earth Sciences

subject:
health geography
worker carers
caregiver employees
labour geography
feminist geography
gender and health

abstract:
Roughly 35% of employed Canadians are currently informal caregivers — defined as “an individual who provides care and/or support to a family member, friend or neighbour who has a physical or mental disability, is chronically ill or is frail” (Williams, Eby, Crooks, Stajduhar, Giesbrecht, Vuksan, Cohen, Brazil, & Allan, 2011, p. 3). These worker-carers are mostly women and often experience negative impacts on their physical, mental, emotional, social, and economic well-being. The impact on employers is also staggering (Fast, Lero, DeMarco, Ferreira, & Eales, 2014). With the number of seniors requiring such care expected to double by 2031, this is a growing issue for Canadians (Williams, et al, 2011). With the assistance of a Technical Committee of experts, chaired by Dr. Williams from McMaster University, the Canadian Standards Association and McMaster University have developed a Standard for Caregiver Inclusive and Accommodating Workplaces. This has been realized through funding provided by the CIHR/SSHRC Partnership Development Grant addressing Healthy, Productive Workplaces. This research seeks to conduct an Enhanced Public Review of the Caregiver Inclusive and Accommodating Standard through the completion of interviews (n=17) with key stakeholders across Canada.
	Semi-structured interviews were conducted from May to July 2017. After reading a draft of the Standard, interviewees were asked about: the viability of implementation of the Standard; what they liked about it, and what they would change, as well as; how it met with the mandate of their own organization. Interviewees represented the senior leadership of a wide variety of organizations including: human resources; caregiver support; unions; white-collar industry; healthcare, and; municipal governments. Following transcription and coding of the interviews using thematic analysis, five major themes emerged.
	First, the Standard is a necessary tool in today’s world. Second, though it is an important tool, it is more likely to be used as an educational tool than to be actually implemented by most organizations. Third, organizations are not likely to implement the Standard for a variety of reasons. For example, small to medium sized organizations do not have the resources or capacity to implement and, given that large organizations already have policies in place, they will view the voluntary Standard as superfluous. Fourth, there is a significant divide in perceptions of sex and gender as relevant to the issue of caregiving and the necessity of supports such as the Standard.  Finally, organizations may be motivated to implement the Standard and/or use it as an educational tool in exchange for tax breaks or insurance incentives, awards and recognition, or for grants to assist in developing and implementing policies related to the Standard.
	We conclude that although there are many barriers to implementation of the Standard, it is a useful and timely tool for organizations to use in order to better support their employees who are engaged in carer roles. Incentivizing implementation may encourage more participation in this program and thus greater support for worker-carers. This is especially important as more than half of carers are women, and women in caregiving roles are more likely to spend much more of their time in that role, meaning that this will keep more women engaged in the labour force, prevent burnout, and support better health outcomes (Sinha, 2012).

abstract: Thesis

abstract: Master of Arts (MA)

abstract: People who are caring for an elderly or sick relative or friend (worker-carers) make up a significant portion of the Canadian workforce. The Canadian Standards Association has developed a voluntary standard for employers to provide accommodations that make working more accessible to employees who are balancing their job with their caring responsibilities. This research assesses the necessity of this Standard and the likelihood that it will be implemented by employer across the country.


title: Characterizing the expression and regulation of FABP4 in response to growth arrest and hypoxia in Chicken Embryo Fibroblasts

contributor:
Bedard, Andre
Biology

subject:
FABP4
hypoxia
growth arrest
contact inhibition

abstract: The process of reversible growth arrest, otherwise known as cellular quiescence or the G₀ phase denoted by withdrawal from the cell cycle, is a poorly characterized state. Subsets of growth arrest-specific (GAS) genes are upregulated during quiescence, however, these subsets are specific to/dependent on the limiting factor or circumstance inducing growth arrest. Here I characterize the expression and regulation of the lipid trafficking GAS gene Fatty Acid-Binding Protein 4 in the quiescence-inducing conditions of contact inhibition and oxygen limitation (hypoxia). Chicken Embryo Fibroblasts (CEF) were cultured to high density or subjected to hypoxia, in which oxygen is the limiting factor inducing growth arrest, or serum starvation, in which nutrients is the limiting factor inducing growth arrest. Contact inhibition and hypoxia induced FABP4 expression, whereas cycling control CEF and serum depleted CEF did not. At higher, though still hypoxic, oxygen levels that did not robustly induce FABP4, proliferation assays showed a slight reduction in CEF proliferation. The GAS gene p20k lipocalin has been shown to exhibit similar expression patterns to FABP4, with its regulation determined by the presence of the transcription factor C/EBP-β. CEF overexpressing C/EBP-β also showed strong FABP4 induction. Furthermore, chromatin immunoprecipitation (ChIP) assays revealed that C/EBP-β bound directly to the FABP4 promoter in both normoxic and hypoxic cells, although only the latter condition induced FABP4 protein expression. In summary, these results suggest that FABP4 is induced during growth arrest specifically when oxygen is the limiting factor, as induction was not seen during growth arrest mediated by starvation-induced endoplasmic reticulum (ER) stress, where nutrients was the limiting factor. The induction of these hypoxia-responsive genes suggests that oxygen availability regulates the expression of a sub-class of growth arrest specific genes. Additionally, FABP4 was shown to be associated with growth arrest and the promotion of cell survival and proliferation, as depicted by proliferation assays. Lastly, C/EBP-β not only strongly induced FABP4 expression, but directly bound to the FABP4 promoter. This suggests that C/EBP-β is a regulator of FABP4, although there may be other interacting factors acting as activators or repressors as this FABP4-C/EBP-β interaction was observed in conditions permissive and non-permissive to FABP4 expression.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: The process of reversible growth arrest is a poorly characterized state. Subsets of growth arrest-specific (GAS) genes are upregulated during quiescence, however, these subsets are specific to the limiting factor or circumstance inducing growth arrest. Here we characterize the expression and regulation of the lipid trafficking GAS gene Fatty Acid-Binding Protein 4 in the quiescence-inducing conditions of contact inhibition (CI) and hypoxia. Chicken Embryo Fibroblasts (CEF) were cultured to high density or subjected to hypoxia, in which oxygen is the limiting factor inducing growth arrest, or serum starvation, in which nutrients availability is the limiting factor. CI and hypoxia induced FABP4 expression, whereas control and serum depleted CEF did not. At higher, though still hypoxic, oxygen levels that did not robustly induce FABP4, proliferation assays showed a slight reduction in CEF proliferation. When overexpressing C/EBP-β, CEF showed strong FABP4 induction. Additionally, a direct interaction with the FABP4 promoter was observed in both normoxic and hypoxic cells, although only the latter condition induced expression. In summary, the induction of this hypoxia-responsive gene suggests that oxygen availability regulates the expression of a sub-class of growth arrest specific genes and that this induction may be regulated by C/EBP-β.


title: Univariate and Bivariate ACD Models for High-Frequency Data Based on Birnbaum-Saunders and Related Distributions

contributor:
Balakrishnan, Narayanaswamy
Mathematics and Statistics

subject: High-frequency financial data

subject: Autoregressive conditional duration model

subject: Conditional quantile duration

subject: Bivariate Birnbaum-Saunders distribution

subject: Bivariate Student-t Birnbaum-Saunders distribution

subject: Maximum likelihood estimation

subject: Nelder-Mead algorithm

subject: BFGS method

subject: Monte Carlo simulation

subject: Density forecast

subject: Goodness-of-fit

subject: Model discrimination

subject: Information-based criterion

abstract: This thesis proposes a new class of bivariate autoregressive conditional median duration models for matched high-frequency data and develops some inferential methods for an existing univariate model as well as the bivariate models introduced here to facilitate model fitting and forecasting. During the last two decades, the autoregressive conditional mean duration (ACD) model has been playing a dominant role in analyzing irregularly spaced high-frequency financial data. Univariate ACD models have been extensively discussed in the literature. However, some major challenges remain. The existing ACD models do not provide a good distributional fit to financial durations, which are right-skewed and often exhibit unimodal hazard rates. Birnbaum-Saunders (BS) distribution is capable of modeling a wide variety of positively skewed data. Median is not only a robust measure of central tendency, but also a natural scale parameter of the BS distribution. A class of conditional median duration models, the BS-ACD and the scale-mixture BS ACD models based on the BS, BS power-exponential and Student-t BS (BSt) distributions, have been suggested in the literature to improve the quality of the model fit. The BSt-ACD model is more flexible than the BS-ACD model in terms of kurtosis and skewness. In Chapter 2, we develop the maximum likelihood estimation method for the BSt-ACD model. The estimation is performed by utilizing a hybrid of optimization algorithms. The performance of the estimates is then examined through an extensive Monte Carlo simulation study. We also carry out model discrimination using both likelihood-based method and information-based criterion. Applications to real trade durations and comparison with existing alternatives are then made. The bivariate version of the ACD model has not received attention due to non-synchronicity. Although some bivariate generalizations of the ACD model have been introduced, they do not possess enough flexibility in modeling durations since they are conditional mean-based and do not account for non-monotonic hazard rates. Recently, the bivariate BS (BVBS) distribution has been developed with many desirable properties and characteristics. It allows for unimodal shapes of marginal hazard functions. In Chapter 3, upon using this bivariate BS distribution, we propose the BVBS-ACD model as a natural bivariate extension of the BS-ACD model. It enables us to jointly analyze matched duration series, and also capture the dependence between the two series. The maximum likelihood estimation of the model parameters and associated inferential methods have been developed. A Monte Carlo simulation study is then carried out to examine the performance of the proposed inferential methods. The goodness-of-fit and predictive performance of the model are also discussed. A real bivariate duration data analysis is provided to illustrate the developed methodology. The bivariate Student-t BS (BVBSt) distribution has been introduced in the literature as a robust extension of the BVBS distribution. It provides greater flexibility in terms of the kurtosis and skewness through the inclusion of an additional shape parameter. In Chapter 4, we propose the BVBSt-ACD model as a natural extension of the BSt-ACD model to the bivariate case. We then discuss the maximum likelihood estimation of the model parameters. A simulation study is carried out to investigate the performance of these estimators. Model discrimination is then done by using information-based criterion. Methods for evaluating the goodness-of-fit and predictive ability of the model are also discussed. A simulated data example is used to illustrate the proposed model as compared to the BVBS-ACD model. Finally, in Chapter 5, some concluding comments are made and also some problems for future research are mentioned.

abstract: Thesis

abstract: Master of Science (MSc)


title: Detecting epidemic coupling among geographically separated populations

contributor:
Earn, David J. D.
Mathematics and Statistics

subject:
epidemiology
spatial coupling
mathematical modeling
dynamical systems
Great Plague
analytical approximation
time to invasion
time faded out

abstract:
The spread of infectious agents has been observed as long as their hosts have existed.  The spread of infectious diseases in human populations, however, is more than an academic concern, causing millions of deaths every year, and prompting collective surveillance and intervention efforts worldwide.  These surveillance data, used in conjunction with statistical methods and mathematical models, present both challenges and opportunities for advancements in scientific understanding and public health.

Early mathematical modeling of infectious diseases in humans began by assuming homogeneous contact among individuals, but has since been extended to account for many sources of non-homogeneity in human contact.  Detecting the degree of epidemic mixing between geographically separated populations, in particular, remains a difficult problem.  The difficulty occurs because although disease case reports have been collected by many governments for decades, case reporting is imperfect, and transmission events themselves are nearly impossible to observe.

The degree to which epidemic coupling can be detected from case reports is the central theme of this thesis.  We present a careful, biologically motivated and consistent derivation of the transmission coupling (fully derived in Chapter 4).  In Chapter 2 we consider the simple scenario of an epidemic spreading from one population to another, and present both numerical and analytic methodology for estimating epidemic coupling.  Chapter 3 considers the problem of estimating epidemic coupling among populations undergoing recurrent epidemics, such as those of childhood diseases which have been widely observed.  In Chapter 4 we present a method for estimating coupling among an arbitrary number of populations undergoing an epidemic, and apply it to estimate coupling among the parishes of London, England, during the Great Plague of 1665.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Smart Home Platform and Hybrid Indoor Positioning Systems for Enabling Aging in Place

title: SMART HOME AND INDOOR POSITIONING SYSTEMS FOR AGING IN PLACE

contributor:
Fang, Qiyin
Biomedical Engineering

subject:
Smart Home
IoT
Health Monitoring
Indoor Positioning
IPS
Aging in place

abstract:
Activities of daily living (ADLs) are everyday routine tasks which provide insight into the physical and cognitive wellbeing of older adults. ADLs are commonly self-reported to clinicians, which can lead to overestimation and underestimation of a patients’ functional abilities. Remote health monitoring is an emerging field aimed at utilizing technology for monitoring ADLs remotely, improving clinical accuracy and enabling older adults to age safely within their homes.
In this dissertation, we report a Smart Home platform and two indoor positioning systems (IPSs) – (i) a hybrid Bluetooth Low Energy (BLE) and radar motion sensor system and (ii) a hybrid radio-frequency identification (RFID) and infrared (IR) range-finding system for tracking occupant mobility, the primary predictor of falls among older adults.
For the Smart Home platform, the design methodology and technological features were explained. As for the IPSs’, position accuracy of multiple occupants within multiple rooms of a residential apartment was evaluated. The systems were also evaluated for cost, implementation ease, and scalability, which, upon reviewing literature, were identified as key metrics for developing an IPS for enabling aging in place. Both IPSs enforced a decentralized localization architecture and performed well, achieving high localization accuracy for multiple occupants.

abstract: Thesis

abstract: Master of Applied Science (MASc)

abstract:
By 2031, the number of people aged 65 and over is expected to nearly double. This population shift is concerning for healthcare providers as limited resources become increasingly constrained. Resultantly, older adults, the largest consumers of healthcare, face longer wait times and reduced quality of care.
Remote health monitoring is an emerging field aimed at utilizing technology for monitoring older adults within their homes. In this thesis, we report a Smart Home platform and two indoor positioning systems (IPSs) for tracking resident mobility, the primary predictor of falls among older adults.
For the Smart Home platform, the design methodology and technological features were explained. As for the IPSs’, position accuracy of multiple occupants within multiple rooms of a residential apartment was evaluated. Upon reviewing literature system cost, implementation ease, and scalability, were identified as key metrics for developing an IPS for enabling aging in place. Both IPSs performed well, achieving high localization accuracy for multiple occupants.


title: Exploring Targets of Allogeneic T cell Activation in Mouse Models of GvHD

contributor:
Larché, Mark
Health Sciences

subject:
GvHD
T-cell
Mouse Models
Bone Marrow Transplant
Peptide Therapy
Complement
Hematopoietic stem cell
HLA
MHC
Allogeneic

abstract:
Allogeneic Hematopoietic stem cell transplants (HSCT) are used for the treatment of bone marrow aplasias. Allogeneic HSCT is performed by treating the patient with chemotherapy drugs and irradiation and then transplanting hematopoietic stem cells from a healthy donor to restore the immune system and hematopoietic cells. Allogeneic HSCTs has the added benefit of the graft vs leukemia effect (GvL), whereby donor allogeneic T cells are able to mount immune responses against any residual cancer cells. However, alloreactivity towards the mismatched minor and major histocompatibility antigens the patient's healthy tissues leads to graft vs host disease (GvHD). This process is also mediated by Macrophages, Dendritic cells, B cells. Furthermore, a decrease in the number of NK, B, and T regulatory cells exacerbates GvHD. This leads to a state of systemic inflammation, tissue damage and multiorgan fibrosis. Current therapies designed to suppress the immune system have been shown to be efficacious in preventing GvHD but patients become susceptible to infection or experience cancer relapse through the elimination of the GvL response as well.
In this thesis, we explore two strategies for targeting T cell activation in two mouse models of GvHD. In the first model, we examined the contribution of donor-derived complement C5 on the induction GvHD. We observed that recipient mice were only protected from GvHD when donor cells were deficient for complement protein C5.
Our second strategy involves selective targeting of alloreactive T cells using peptide immunotherapy. For this approach, we first developed a humanized mouse model of GvHD whereby cells from donor mice expressing human class II HLA were reconstituted into recipient mice expressing human class I HLA. We then tested peptide immunotherapy using peptides derived from the human class I HLA. Our initial results were inconclusive and require further optimization.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Graft vs Host Disease is an unwanted side effect of mismatched bone marrow transplant. Donor T cells recognize and attack mismatched tissues of the recipient and this leads to systemic inflammation and tissue scarring. Current treatments primarily target T-cell activation by suppressing the immune system, however, this leaves the patients susceptible to recurrent infections. In this thesis we describe the creation of two mouse models of Graft vs Host Disease and then examine two ways of specifically targeting donor T cell activation that is designed not to affect normal immune responses.


title: Effects of Vasoflux on DNA-Histone Complexes in Vitro and on Organ Function and Survival Outcome in a Murine Model of Sepsis

contributor:
Liaw, Patricia
Medical Sciences

subject:
Sepsis
Neutrophil Extracellular Traps (NETs)
Cell-free DNA (cfDNA)
Cecal Ligation and Puncture (CLP)
Murine model
Unfractionated heparin (UFH)
Vasoflux
Histones

abstract: Sepsis is life-threatening organ dysfunction produced by a dysregulated host response to infection in which neutrophils release neutrophil extracellular traps (NETs). NETs consist of DNA, histones, and antimicrobial peptides which kill pathogens. However, DNA and histones also exert damage by activating the intrinsic pathway of coagulation and inducing endothelial cell death, respectively. AADH, a 15kDa non-anticoagulant unfractionated heparin (UFH), prevents histone-mediated cytotoxicity in vitro and improves survival in septic mice. We explored the effectiveness of Vasoflux, a 5.5kDa low-molecular-weight-heparin as an anti-sepsis treatment as compared to enoxaparin and UFH. Vasoflux has reduced anticoagulant functions and hence reduces the risk of bleeding as compared to enoxaparin or UFH. We showed that UFH, enoxaparin, or Vasoflux at concentrations of up to 13.3uM, 40uM, or 40uM, neutralize histone-mediated cytotoxicity. These results suggest that these glycosaminoglycans (GAGs) are able to neutralize histone-mediated cytotoxicity independent of the AT-binding pentasaccharide. To quantitate the binding affinity between GAGs and histones, surface plasmon resonance was conducted. UFH is a more potent inhibitor of histone-mediated cytotoxicity compared to Vasoflux as UFH has a 10-fold greater binding affinity to histones compared to Vasoflux. To translate our in vitro findings to in vivo, Vasoflux, enoxaparin, and UFH were administered in a murine model of sepsis. Vasoflux at 8mg/kg - 50mg/kg reduced survival and exhibited damage in the lung, liver, and kidney in septic mice compared to 10 mg/kg of UFH or 8mg/kg of enoxaparin. This may be due to Vasoflux and UFH disrupting the DNA-histone complex, thereby releasing free procoagulant DNA. This is evident by our gel electrophoresis experiments, where addition of 1uM Vasoflux or 3.3uM UFH to DNA-histone complexes lead to histone dissociation from DNA. UFH bound to histones may be able to inhibit DNA-mediated thrombin generation, as it retains its anticoagulant properties, demonstrated by UFH-histone complexes attenuating DNA and TF-mediated thrombin generation. In contrast, Vasoflux may not neutralize the procoagulant DNA leading to a hypercoagulable state in the mice. Our study may have important clinical implications as there is an ongoing trial, HALO, which will administer intravenous UFH to patients suspected to have septic shock to reduce mortality. Based on our results, future clinical trials should consider the antithrombin-dependent anticoagulant activity of UFH being used as a sepsis treatment.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Sepsis is a life threatening condition caused by the body’s extreme response to microbial infection of the blood, whereby neutrophils release traps composed of cell-free DNA (cfDNA), histones, and antimicrobial proteins. In addition to fighting off infections, these traps also exert harmful effects like triggering clotting and killing host cells. Currently, no specific anti-septic drugs exist. Studies have shown that DNase1 (a recombinant protein that digests double stranded cfDNA) or a modified form of heparin (neutralizes histones) improves survival in septic mice. Our goal was to explore the protective effects of Vasoflux, (a non-anticoagulant heparin) and DNase1 in a mouse model of sepsis. We hypothesize that the combined therapy of DNase1 and Vasoflux will improve survival. We found that Vasoflux has minimal blood thinning activity and can prevent histones from killing cells. However, Vasoflux administered into septic mice worsened organ damage and decreased survival. We hypothesize that this damage may be due to Vasoflux’s ability to displace histones from histone-DNA complexes, thereby releasing free DNA, which promotes excessive blood clotting in sepsis.


title: New Roles for PagP in the Bacterial Outer Membrane Stress Response

title: The Multifunctional Enzymology of PagP

contributor:
Bishop, Russell
Biochemistry and Biomedical Sciences

subject: PagP Lipids Membranes Bacteria

abstract:
The ability of Gram-negative bacteria to modulate outer membrane (OM)
composition in response to stressful environments is essential for their survival
and replication within host tissues. The OM enzyme PagP catalyzes the transfer of
palmitate from a glycerophospholipid to lipid A. Lipid A is the endotoxic portion
of LPS responsible for transmembrane signalling to initiate the immune response.
Palmitoylation of lipid A can either attenuate or stimulate the immune response
depending on where the palmitate chain is attached to a specific lipid A molecule.
Here we report that the Escherichia coli PagP homolog is a multifunctional
enzyme, which displays two distinct active sites exposed on either side of the
bacterial OM. E. coli PagP converts phosphatidylglycerol (PG) to palmitoyl-PG
(PPG) using the same cell surface active site involved in the palmitoylation of
lipid A. PPG is then serially degraded to bis(monoacylglycero)phosphate (BMP)
and either lyso-PG or lyso-BMP by a novel lipase active site located in PagP on
the periplasmic side of the OM. The periplasmic lipase active site can be
inactivated with the Y87F amino acid substitution. BMP is a novel
glycerophosphoglycerol (GPG) that has not previously been reported in bacterial
lipid metabolism. Not all PagP homologs have this ability to remodel GPGs. We
have identified a divergent lipid A palmitoyltransferase in Pseudomonas
aeruginosa that does not palmitoylate PG. The P. aeruginosa homolog also has
different lipid A regiospecificity, adding palmitate on the opposite glucosamine at the 3’-position compared to the 2-position of the proximal sugar observed for the
E. coli homolog. We have determined that P. aeruginosa PagP is representative of
a distinct clade of PagP evolved to fulfill different functions. Although this minor
clade is inclusive of homologs that lack obvious sequence similarity with the
major clade enterobacterial PagP, we have identified conserved catalytic and
structural elements within the minor clade that contribute to our growing
understanding of homologous PagP structure/function relationships. A
comparative analysis of all available sequences of minor clade PagP homologs has
revealed invariant His, Ser, and Tyr residues that are necessary for catalysis.
Additionally, a 4-amino acid conserved signature indel or CSI is unique to
bacteria clustered phylogenetically within the γ-subclass of Proteobacteria.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Enhanced Fields of View in Epoxide Waveguide Arrays doped with Au Nanoparticles

contributor:
Saravanamuttu, Kalaichelvi
Fradin, Cecile
Chemistry and Chemical Biology

subject:
Waveguide
Fields of View
Gold Nanoparticles
Polymer
Self-trapping

abstract: Polymer matrices doped with a dispersion of noble metal nanoparticles combine the strong plasmon resonance-based optical signatures of the latter with the flexibility and processability of the former. We have developed a nonlinear lithographic technique to generate large populations of epoxide waveguides containing a uniform dispersion of Au nanoparticles. The method is based on the self-trapping of multiple beams of white light propagating through a catonic polymerizable matrix doped with a gold salt, initiating the polymerization of epoxide moieties and simultaneously the in situ synthesis of elemental Au nanoparticles. Each white light filament inscribes a cylindrical waveguide, leading to an array of metallodielectric waveguides. Field of view (FOV) measurements indicate that the metallodielectric waveguide array has a nearly 59 % increase in FOV relative to its all-dielectric counterparts and can be tuned through the concentration of Au nanoparticles and the optical intensities employed to generate waveguides.

abstract: Thesis

abstract: Master of Science (MSc)


title: Sorption Study of Se(-II) onto Illite, Bentonite, and Shale Under High Ionic Strength Conditions

contributor:
Nagasaki, Shinya
Engineering Physics

subject:
selenium
reducing condition
sorption
distribution coefficient
anion
surface complex

abstract: Due to the very long half-life of Se-79 and its presence in used nuclear fuel, Se is an element of interest in the safety assessment for a deep geological repository (DGR) for used nuclear fuel. Sorption of radionuclides onto the surrounding host rocks and engineered barrier materials is a potential retardation mechanism for radionuclide transport. This thesis investigates the sorption of Se(-II) onto illite, bentonite (engineered barrier material), and shale under high ionic strength conditions relevant to a Canadian DGR. The ionic strength and pH dependence of Se(-II) sorption onto illite, bentonite, and shale were studied. A non-electrostatic surface complexation model was also developed for Se(-II) sorption onto illite and montmorillonite to investigate the sorption mechanisms by which Se(-II) sorbs onto these solids.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Effects of white-tailed deer and invasive garlic mustard on native tree seedlings in an urban forest

contributor:
Dudley, Susan
Biology

subject:
forest
ecology
deer
garlic mustard

abstract: An ongoing goal in forest ecology is to understand how animal populations and invasive plants affect forest communities. Reduced numbers of native tree saplings in urban forests have driven concerns that overabundant white-tailed deer (Odocoileus virginianus) populations and invasive plants are both suppressing the size and survival of native tree seedlings. Previous work has focused on the individual effects of either deer or invasive plants, but few studies have examined the combined effects of these two stressors. In this study, I examined the effects of white-tailed deer and garlic mustard (Alliaria petiolata) on transplanted seedlings of three native tree species: northern red oak (Quercus rubra), black cherry (Prunus serotina), and eastern hemlock (Tsuga canadensis). To test for their individual and combined effects on seedlings, I designed a factorial experiment where I manipulated the level of deer presence with exclosures and the level of garlic mustard presence by weeding. To measure the impacts on seedlings, I scored browse damage, tracked survival, and measured multiple size traits for each study species. I found that deer presence reduced seedling size but did not affect mortality within the short duration of the study. In addition, seedlings were not affected by garlic mustard removal, nor did the effects of deer depend on garlic mustard presence. While all species were impacted by deer, seedling browsing patterns varied among tree species. Moreover, I found that browsing by deer is changing the species composition within McMaster Forest to favour browse tolerant tree species. These results have implications for management strategies in forests with high deer densities which should prioritize controlling the deer population in addition to invasive plants and should be tailored to conserve the most sensitive species.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Reduced numbers of native tree saplings in urban forests have driven concerns that overabundant white-tailed deer populations and invasive plants are both suppressing the size and survival of native tree seedlings. In this study, I examined the effects of white-tailed deer and garlic mustard on transplanted seedlings of three native tree species: northern red oak, black cherry, and eastern hemlock. I found that deer browsing reduced seedling size but did not reduce survival. I found that browsing by deer is changing the species composition within McMaster Forest to favour browse tolerant tree species. Seedlings were not affected by garlic mustard removal, nor did the effects of deer depend on garlic mustard presence. These results have implications for management strategies in forests with high deer densities which should prioritize controlling the deer population in addition to invasive plants and should be tailored to conserve the most sensitive species.