contributor:
Richards, Carl D.
Medical Sciences

abstract: Title: The Role of the Oncostatin M-STAT6 Axis in Pulmonary Eosinophilia, Goblet Cell Hyperplasia, Airway Hyperresponsiveness and Pulmonary Fibrosis, Author: Dominik K. Fritz, Location: Mills

abstract:
Various mediators including cytokines control and modulate inflammatory
responses in tissues and organs that incorporate cell infiltration, accumulation and
extracellular matrix remodeling. Oncostatin M (OSM), a pleiotropic and
multifunctional cytokine of the gp130 cytokine family, has been shown to be
upregulated in allergic and fibrotic airway disease conditions associated with
tissue eosinophilic inflammation. In an in vivo model of airway disease, previous
work has shown that transient overexpression of OSM in mouse lungs elicits
marked pulmonary eosinophilic inflammation and interstitial pulmonary fibrosis
implicating OSM in pulmonary eosinophilic diseases. Among the gp130 cytokine
family members, OSM has been established to exhibit unique and/or potent
connective tissue responses in vitro and in vivo, which may be of important
consequence in pulmonary disease conditions. This thesis provides experimental
work that examines the mechanism of OSM induced fibroblast cell responses in
vitro, and further examines mechanisms of OSM function in an in vivo model of
airway disease. The research presented identifies OSM as a unique gp 130
cytokine family member in regulation of the STAT6 signaling/transcription
factor, which was originally characterized as a signaling pathway activated
downstream of the IL-4 receptor (IL-4R) by the TH2 cytokines IL-4 and IL-13.
This novel finding provided a foundation for subsequent studies, which examined
the role of STAT6 in the regulation of OSM-induced connective tissue responses in the context of pulmonary inflammation. Migration of eosinophils from circulation and into inflamed lungs is orchestrated by the upregulation of adhesion molecules (VCAM-1) and the establishment of an eosinophil-selective chemotactic gradient ( eotaxins ). It is demonstrated here that OSM potently induces VCAM-1 upregulation and enhances IL-4/IL-13-induced eotaxin-1
expression in lung fibroblasts in comparison to other gp130 cytokines. The
STAT6 signaling/transcription factor was found dispensable for VCAM-1
induction, but not for enhanced eotaxin-1 responses. Oncostatin M was also found
to be a unique and potent gp130 cytokine in stimulating IL-4R expression in lung
fibroblasts in a STAT6 independent fashion, which correlated with enhanced IL-
4/IL-13-induced eotaxin-1 production and STAT6 activation. These experimental
findings indicated that OSM can sensitize lung structural cells to IL-4/IL-13-
induced responses, which could mediate sustained pulmonary eosinophilic
inflammation in vivo. In examining mouse lungs in vivo, transient overexpression
of OSM induced a T H2-biased inflammatory profile characterized by T H2
cytokine (IL-4, IL-5, IL-13), IL-4R and chemokine (eotaxin-1/2, MCP-1, KC)
expression as well as sustained eosinophilic inflammation, mucous/goblet cell
hyperplasia, pronounced interstitial extracellular matrix (collagen, a SMA)
deposition and airway hyperresponsiveness (AHR). Induction of T H2 cytokines
(IL-4, IL-13) and chemokines (eotaxin-112, MCP-1), pulmonary eosinophilia,
mucous production and AHR were dependent on STAT6, however induction of
IL-4R and interstitial pulmonary extracellular matrix deposition was not. Therefore, this experimental work demonstrates that OSM regulates STAT6-dependent and -independent inflammatory mechanisms that may be important in the control of both allergic and interstitial fibrotic disease processes in the lung.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Knights, A. P.
Engineering Physics

abstract: Title: Characterization and Integration of Defect-Mediated Photodetectors for Silicon Photonic Circuits, Author: Jonathan Doylend, Location: Mills

abstract:
Silicon photonic interconnects represent a possible solution to the problems
associated with scaling electrical interconnects to higher data rates. Defectmediated
optical detectors fabricated via inert ion implantation incorporated with
optical waveguides in such a circuit allow control and monitoring of the optical
signal and can be fabricated entirely using standard Complementery Metal-Oxide
Semiconductor (CMOS) fabrication steps, thus simplifying the task of integrating
optical functionality alongside electronic circuits on a chip.

In the work described in this thesis, the defects involved in the detection process at wavelengths at and around 1550 nm have been investigated. For low-dose ion implantation, the defect which dominates optical absorption and detection is shown to be an acceptor with an energy of 0.41 ± 0.02 eV below the conduction band, properties consistent with the silicon divacancy. A novel technique for
optical characterization has been developed and used to determine the optical
cross-section of this defect to be 6 x 10-17 cm2 for a wavelength of 1550 nm.
Defect concentration versus thermal annealing temperature was evaluated, and
waveguide integrated detectors were fabricated and used to characterize optical
absorption and quantum efficiency as a function of the annealing conditions.

A monolithically integrated device comprising a defect-enhanced photodiode and
a variable optical attenuator was designed, modeled, fabricated, and demonstrated
with the photodiode used to monitor and control the optical output power. To
illustrate the potential of such a device, it was operated as a dynamic channel
leveller with external software used to mimic an electronic feedback loop between
the detector and attenuator. The channel leveller was able to maintain ± 1 dB
output power variation across a 7-1 0 dB input dynamic range for wavelengths
ranging from 1530 nm to 1570 nm.

Additionally, a tunable resonant defect-enhanced photodiode was designed, modeled, fabricated, and characterized. It is shown that resonant effects can be used to obtain similar responsivity from a small, lightly absorbent photodiode as would otherwise require a longer, highly absorbent photodiode, thus enabling
very low minimum detectable power. The device responsivity was measured to
be greater than 0.1 A/W for wavelengths ranging from 1510 nm to 1600 nm, with
individual wavelengths selectable by tuning the resonance peak. The device was
also demonstrated as a variable optical attenuator with 20 dB extinction, less than
44 m W switching power, and integrated monitoring.

The devices described in this thesis represent the first reported demonstrations of integrated optical power control, dynamic channel levelling, and tuneable resonant detection using defect mediation in a silicon photonic circuit.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Investigating the Dispensability of Wall Teichoic Acid in the Gram-Positive Bacteria Subtilis and Staphylococcus Aureus

contributor:
Brown, E. D.
Biochemistry and Biomedical Sciences

abstract: Title: Investigating the Dispensability of Wall Teichoic Acid in the Gram-Positive Bacteria Bacillus Subtilis and Staphylococcus Aureus, Author: Michael A. D'Elia, Location: Mills

abstract:
In recent decades, the emergence of multi-drug resistant pathogenic organisms
has proven to be a significant threat to human health. Today, resistant organisms have
been identified for every class of antibiotics introduced into clinical practice. Combining
this with the knowledge that the introduction of new antimicrobial classes has been
almost non-existent since the early 1960's, stresses the importance for new chemical
scaffolds and novel therapeutic targets to combat this growing crisis. This thesis focuses
on one potential target in Gram-positive bacteria, the biosynthesis of wall teichoic acid
polymers. In particular, this study centers on investigating the dispensability of these
polymers in both Bacillus subtilis and Staphylococcus aureus, highlighting the utility of
these biosynthetic enzymes as novel therapeutic targets.

Despite significant examination of teichoic acid gene dispensability in the model organism, B. subtilis, the complexity surrounding gene dispensability was not appreciated until this study. Studying both B. subtilis and S. aureus, a peculiar gene dispensability pattern was uncovered in which early acting enzymes; those responsible for disaccharide synthesis, were dispensable for cell viability, yet the remaining late-acting enzymes remained essential. This paradox was reconciled by demonstrating that the lethality associated with the deletion of late-acting genes could be suppressed by deletion of the early genes. Notwithstanding the ability to survive devoid of wall teichoic acid, these polymers remain an absolute requirement for pathogen virulence.

The discoveries presented here have provided remarkable insight into
understanding of wall teichoic acid gene dispensability and the complexity associated
with this pathway. Furthermore, the ability to generate bacterial strains devoid of wall
teichoic acid in both B. subtilis and S. aureus will provide tremendous utility for
uncovering a function for this important cell wall component.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Elbestawi, M. A.
Mechanical Engineering

abstract: Title: Modeling the Dynamics of Plunge Milling with Workpiece Vibrations Consideration, Author: Ahmed Damir, Location: Mills

abstract:
Chatter vibrations in machining processes remain one of the major challenges that face
the machining process planners to achieve high productivity and product quality. This is
mainly due to its undesirable effect that leads to poor surface finish, low part dimensional
accuracy, excessive tool wear and reduced productivity. Therefore, for high performance
machining, it is extremely important to predict and model the process stability in order to
be able to plan the process prior to machining. This will eliminate the need for trials and
errors to select the optimum cutting conditions for each operation.

Plunge milling process is becoming an important rough machining operation for die
cavities and aerospace parts. This is due to a higher removal rates when compared to
other milling processes. This is mainly attributed to the fact that most of the cutting is
performed in the axial direction, so that the process can benefit from the spindle rigidity
to achieve higher metal removal rates. However, limited published research has been
done to model the dynamics and stability of plunge milling and there is a need to study in
depth the stability of this process while considering the effect of some parameters not
studied in the literature on the process stability.

A time domain simulation model is developed in this research to study the dynamics of plunge milling process for systems with rigid and flexible workpiece. The model predicts the cutting forces, system vibration and process stability by considering the effect of workpiece and tool dynamics, tool setting errors and tool kinematics on chip area evaluation. The dynamic chip area is evaluated based on the interaction of the insert cutting edges (i.e. main and side edges) with the workpiece geometry determined by the pilot hole and surface left by the previous insert. A horizontal approach was used to model the insert geometry to be able to compute correctly the cutting area used in force prediction. This approach considers the contribution of both main and side edge in the
cutting zone and is capable of dealing with any geometric shape of the insert. Mechanistic
model is used to compute the cutting forces as a function of the dynamic chip area using
instantaneous cutting coefficients for each insert to take into account the uneven chip thickness removed by each insert as a result of system vibration and tool setting errors.
For the case of a flexible workpiece, the dynamics of the workpiece and milling cutter in
three directions, lateral and axial directions, as well as the tool torsional vibration, are
considered in the model for accurate prediction of forces and stability limits. The
variation of workpiece dynamics according to the hole location is considered in the
simulation to model the process stability based on the actual system dynamics as a
function of hole location. On the other hand, for a rigid workpiece, only the dynamics of
the cutter is considered in the simulation.

Experimental cutting tests with single and double were carried out to check the validity of the simulation model for both cases of plunge milling of rigid and flexible workpiece. Experimental validation for single insert showed the ability of the simulation model to simulate the dynamics of plunge milling with single insert as well as the correctness of the cutting force model.

For case of plunge milling with double inserts, good agreement was found between the measured and the predicted cutting forces and vibration signals and power spectra for case of rigid and flexible workpiece. This indicates the ability of the model to accurately predict cutting forces, system vibration and process stability which makes it very reliable and effective to be used for process planning prior to machining. Both experimental and simulation results showed dominance of workpiece dynamics in the axial direction due to its flexibility as compared to the tool axial rigidity for systems with flexible workpiece. On the other hand, chatter behavior was found to occur due to tool lateral modes for case of rigid workpiece.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Mineralogical and Fluid Inclusion Study of Massive Sulphide Samples from the Juan De Fuca Ridge, Northeast Pacific Ocean

contributor:
Crocket, J. H.
Geology

subject: mineralogical, fluid, inclusion, study, massive sulphide, samples, hydrothermal, salinities

abstract:
 In the past decade, sites of hydrothermal activity along the Juan de Fuca Ridge have gained a growing amount of attention. Increased sampling has provided the materials for more detailed studies, including those collected from Axial Seamount, a large shield volcano on the central portion of the ridge. Axial Seamount is host to at least three active vent sites, one of which, along the northwest caldera wall, consists of recently active eruptive-fissures and nearby chimney-like spires. A sampled spire from this location and samples from other vent areas are described using reflected and transmitted light techniques. They have been
found to consist of the sulphide phases sphalerite, wurtzite, pyrite, marcasite, chalcopyrite, isocubanite, and galena. Jordanite and tetrahedrite-tennanite are also known to
precipitate at these vent sites, but were not observed here. The most dominant non-sulphide minerals are amorphous silica and barite. Native sulfur, Fe and Mn oxides and a variety of
sulfosalts may also be present. The complex textures in these samples reflect precipitation and growth from higher temperature fluids that are mixing with local ambient seawater. Fluid inclusions in sphalerite have revealed salinities in the 5.6 to 7.0 weight % NaCl range, with
homogenization temperatures ranging from 214.8°C to 269.4°C. Temperatures of homogenization require pressure-corrections between approximately 9.0°C and 13.0°C, to set-up a range of trapping temperatures that lie between 211.8°C and 279.4°C. Fluid inclusions are also found in wurtzite, barite, and amorphous silica however, these would yield no data. Middle Valley is a sedimented rift valley that lies at the extreme north end of the Juan de Fuca Ridge. A number of hydrothermal sulphide mounds that lie atop the sediment pile have been sampled. The mineralogy is similar to that at Axial Seamount; however, the dominant sulphide phase at Middle Valley is pyrrhotite. Textural differences between the two
sites are significant, a result of the traversing of hydrothermal fluids through a thick package of hemepelagic sediment at Middle Valley. Samples from Middle Valley are found to contain no measurable fluid inclusions in the sections available for study. Mineralogical and fluid inclusion studies are important methods that can be used to help solve the complex growth history of sulfides that are and have been accumulating at mid-ocean ridge vent sites.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Aluminum Speciation Using Fluorescence Quenching

contributor:
Kramer, J. R.
Chemistry

subject: aluminum, speciation, fluorescence, quenching, organic ligands, Stern-Volmer

abstract:
 A noninvasive method using fluorescence quenching (FQ) to determine the conditional stability constants (logK') for aluminum with naturally occurring organic ligands has been developed. The method utilizes the Stern-Volmer equation to interpret data from ligand fluorescence suppression by aluminum. The total ligand concentration can also be determined using the measured stability constant and the Ryan-Weber equation. The method has been validated with the model ligand salicylic acid; logK' was found to be 3.5 ± 0.01 vs. 4.0 from the literature. The method was applied to the reference ligand Armadale fulvic acid and chemically realistic values were obtained. In addition, the expected trend of increasing stability constant with decreasing pH was observed. The method was further validated by determining the stability constant for Armadale fulvic acid using an independent technique, PCV colourimetry; the results agreed very well logK' = 4.7 vs. 4.65 for FQ analysis.
Application of the method to whole filtered beaver pond water showed an increasing
trend in the stability constant as the dissolved organic carbon (DOC) decreased. The
Log of the stability constants were 3.15 ± 0.03, 3.26 ± 0.03, and 3.63 ± 0.02 for DOC
concentrations 23, 14, and 10 ppm respectively. The method was also applied to size fractionated waters form lake Skjervatjern in Norway and the expected trend of increasing stability constant with increasing molecular weight was observed.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Up-rooted Lives, Deep-rooted Memories: Stress and Resilience among Jamaican Agricultural Workers in Southern Ontario

contributor:
Yong, Kee
Anthropology

subject:
farm workers
stress
resilience
labour migration

abstract: The Seasonal Agricultural Worker Program (SAWP) is a transnational labour agreement between Canada, Mexico, and various Caribbean countries that brings thousands of Jamaican migrant workers to Canada each year to work on farms. This thesis explores Jamaican SAWP workers’ experiences of stress in Ontario, and situates these experiences within a system of power and international inequality. When describing their experiences of stress and suffering in Ontario, many Jamaican workers drew analogies between historic and modern slavery under the SAWP. However, stress discourses also inspired workers to emphasise their resilience, and many workers gave equal attention to explaining their inherent strength as “Jamaicans”, which they associate with national independence and the history of slavery. In this way, I suggest stress discourses are sites of flexibility and resilience for Jamaican workers, and this thesis presents the foremost cultural, political, and historical factors that support Jamaican workers’ resilience in Ontario. Moreover, the predominant coping strategies workers employ in Ontario will be explored within the context of their restricted agency under the SAWP. This thesis concludes with a discussion of stress as an expression of subjectivity that is characterised by strength, faith, and the history of slavery.

abstract: Thesis

abstract: Master of Arts (MA)


contributor:
Walmsley, Peter
English

abstract: Title: A Physiology of the Imagination: Anatomical Faculties and Philosophical Designs, Author: Jody W. McNabb, Location: Mills

abstract:
This study charts the eighteenth-century phenomenon that is the faculty of imagination. I
follow its disciplinary conversion from neurology to philosophy, and, ultimately, to
literary criticism; the physiological and philosophical conjunctions that originate with an
internalist reconstruction of Thomas Willis' Anatomy of the Brain, carry over into the
imaginative principals of temporality in A Treatise of Human Nature, and provide
narrative unity and sensory parameters to an understudied literary criticism of attention.
This project identifies the key concepts within psychophysiology to be imagination,
original sensations, habitual ideas, cross-faculty interdependence, an involuntary system
of sensible impressions, and associative modes of attention that collectively form the
coherent elements of its tradition. The Anatomy provides the anatomical schematics for
the faculties and nervous physiology, and positions the imagination to be the preeminent
faculty that responds to sensation and links faculty processes. It also rejects the
seventeenth-century division between rational and sensitive souls; cerebral complexity
demonstrates cognitive capacity as either rational or sensitive. The corpuscular
generation of animal spirits contextualizes materialism before the 1700s. Willis suggests
the involuntary and voluntary systems, though united, have distinct functions, a discovery
that explains Willis' two localizations for memory as natural and rational. Applying
Willis ' physiology as a framework to navigate the Treatise's eighteenth-century
terminology, the Treatise achieves a textual synthesis between imagination and the
passions. This physiological reading of the Treatise's theory of association establishes the
sustainable limits in cognitive attentions. It finds the imagination to be an associative
compulsion and a comparative act that perpetually reconstructs ideas. Finally, Hume's
physiological method grounds the aesthetics of Alexander Gerard and Lord Karnes. The
latter take Hume's attention, association, and faculty interdependence, as a model for the
reader's ability to successfully sustain attention upon narrations. They show that narrative
conjunctions depend on the strength that sensations forge lasting associations. These
studies may have different applications in view, but their core ideas demonstrate a
coherent and pervasive methodology.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Baetz, Brian
Dickson, Sarah
Civil Engineering

abstract: Title: Improving Medium- and Long-Range Hydrological Forecasts with Ensemble Meteorological Forecasts and Climatic Information, Author: Getnet Y. Muluye, Location: Mills

abstract:
The ability to provide reliable and accurate medium- and long-range hydrological
forecasts is fundamental for the effective operation and management of water resources
systems. The principal objectives of this thesis are (i) to develop a framework for
advancing the long-range forecasting skills of hydrological models by coupling pertinent
and leading climate information with regional hydro-meteorological variables; and (ii) to
develop effective mechanisms for integrating meteorological ensemble systems in a
hydrologic prediction system, which would be useful for risk analysis by policy makers
for operating both large-scale as well as small-scale water resources systems. This
research constitutes three principal components: long-range forecasts, downscaling, and
medium-range forecasts.

For long-range hydrological forecasting, four data-driven models, including multilayer perceptron (MLP), time-lagged feedforward network (TLFN), Bayesian neural network (BNN) and recurrent multilayer perceptron (RMLP) were designed by
incorporating low-frequency climatic indices to forecast seasonal reservoir inflows. The
results indicated that the incorporation of modes of climatic indices in a hydrologic
forecasting model resulted in a considerable improvement in the seasonal forecast
accuracy. Furthermore, the extended Kalman filter approach was used to train the
recurrent multilayer perceptron for capturing the complexity associated with the long range
streamflow forecasting. Results showed that the proposed methodology was able to
provide a robust modeling framework capable of capturing the complex dynamics of the
hydrologic system.

Different statistical methods were developed and evaluated for downscaling local scale information of precipitation and temperature from the numerical weather prediction model output. Three different methods were considered: (i) hybrids; (ii) neural networks; and (iii) nearest neighbor-based approaches. The findings revealed that the skills in the downscaled temperature forecasts were superior to those in the downscaled precipitation forecasts. In particular, for downscaling daily precipitation, the artificial neural network-logistic regression (ANN-Logst), partial least squares (PLS) regression and recurrent
multilayer perceptron trained with the extended Kalman filter (EKF) models yielded
greater skill values, and the conditional resampling method (SDSM) and K-nearest
neighbor (KNN) based models showed potential for characterizing the variability in daily
precipitation.

For the case of medium-range hydrological forecasting, the downscaled and the raw numerical model outputs were forced into an HBV hydrologic model in order to
generate an ensemble of reservoir inflows. The simulation results indicated that the
downscaled-based flows had greater skill values, and yielded more accurate forecasts
than the raw-based flows. The potential economic values of flow forecasts were further
assessed based on a simple optimal decision-making, cost-loss analysis technique. The
principal outcomes emerging from the analyses included: (i) the economic benefits
associated with probabilistic flow forecasts were more useful than their deterministic
counterparts; and (ii) the downscaled-based flow forecasts offered greater benefits, which
are applicable to a much wider range of users, than the raw-based flow forecasts.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: An Assessment of Coral Reefs in Ambon, Indonesia

contributor:
Risk, Michael J.
Geology

subject: coral, reefs, Ambon, Indonesia, assessment, marine, resources, environmental changes, species, sedimentation, water

abstract:
 Increasing human activity and population pressure on coastal marine resources, especially coral reefs, in Ambon have caused significant stresses on coral communities requiring careful management. A suitable environmental management strategy for this complex ecosystem, however, must be based on an accurate assessment of the state of these resources, natural variability, and the impact of human activities. Consequently, baseline research is needed to describe reef areas and to provide data about environmental changes.

 One control site (Tanjung Setan) and three affected sites (Hila, Wayame and Wailiha) on Ambon were observed to assess the condition of the reefs. Coral cover, coral growth rate, species richness and environmental parameters such as suspended particulate matter (SPM), resuspended sediment, salinity, temperature, dissolved nutrients (NO3 and PO4), δ15N, and water clarity were measured to assess reef condition and to determine the possible causes of reef degradation.

 Average coral cover in the control site (Tanjung Setan) is higher (64%) than that in affected sites: Hila (27%), Wayame (36%) and Wailiha (11%). Also, the greatest number of species was found in Tanjung Setan (101 spp.) followed by Hila (66 spp.), Wayame (62 spp.) and Wailiha (43 spp.).

 Coral growth rates show different trends from coral cover and number of species. Corals in Tanjung Setan have higher growth rate (1.61 cm/year) than those in Hila (1.45 cm/year) and Wayame (1.31 cm/year), but corals in Wailiha show almost the same growth rate (1.57 cm/year) with that in Tanjung Setan. The surprisingly rapid growth rates at Wailiha are probably caused by high nutrient availability and rapid growth of corals to keep pace with high sedimentation rates.

 The δ15N content of coral tissue was analyzed at each site to trace the sewage (nutrients) loading from the land. Relatively high ratio of δ15N found in Wailiha and Wayame indicated sewage (nutrients) inputs to the reefs in these areas. In addition, limited lignin testing on corals from Wailiha showed positive results, indicating that the plywood factory adjacent to the reef influences the corals there.

 High SPM and resuspended sediment values, high dissolved nutrients and δ15N content, and turbid water in Wayame and Wailiha indicated that these reefs are under siltation and sewage (eutrophication) stress. Hila mainly suffered from physical disturbance such as fish blasting and coral collecting, suggested by bomb craters and coral fragments. Conversely, no significant evidence of human impact was found in the control site (Tanjung Setan), where SPM, resuspended sediment, dissolved nutrients, and δ15N values are all low, and water clarity is very high.

abstract: Thesis

abstract: Master of Science (MSc)


contributor:
Schuller, Eileen
Religious Studies

abstract: Title: Patterns of Daily Prayer in Second Temple Period Judaism, Author: Jeremy Penner, Location: Mills

abstract:
This dissertation examines the origins and development of daily prayer, particularly the establishment offixed times for daily prayer that emerged in Second Temple period Judaism. In this historical period, fixed daily prayer was becoming popular, but since it lacked explicit biblical warrant, a number of strategies emerge at this time to legitimize and promote this custom as an important religious practice. This was accomplished through making times of prayer analogous to fixed patterns of time already entrenched within, and integral to, Jewish daily life.

Through a survey of the relevant Second Temple textual material, I found three different strategies for fixing patterns of daily prayer: 1) in some cases daily prayer was coordinated with, and made analogous to, daily cultic sacrifice. 2) In other cases, daily prayer was legitimized by identifying its origins in sacred scripture, either through the exegesis of a certain verse (Deut 6:7), or by finding a biblical exemplar (Moses) within a historical narrative. Lastly, 3) in some contexts daily prayer was coordinated with the daily cycles of the heavenly luminaries. A Weltbild in which the heavenly luminaries and divine beings coalesce provided the impetus for the third pattern.

These strategies were derived from how daily prayer was understood and experienced, and they give us some insight into the different social and geographical settings in which daily prayers were recited. In sources that utilize scripture to legitimate daily prayer, the household was an important place. While these sources imply that all Jews should pray daily, the custom espoused by this pattern does not require the participation of a congregation in a set location. Fixed daily prayer was recited in communal settings where we see a higher degree of ritual expression, such as in the Qumran community. In this context, prayer based on the cycles of the luminaries was the preferred pattern, not only because it is more apt for praying communally, but also because it was rich in cosmic symbolism that was easily utilized.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Leigh, William J.
Chemistry

abstract: Title: Mechanistic Studies of the Reactions of Transient Diarylgermylenes and Tetraarylgermylenes in Solution, Author: William J. Huck, Location: Mills

abstract:
The reactivity of diarylgermylenes (GeAr2, Ga-g) with tetrahydrofuran, diethylamine, acetic acid, carbon tetrachloride and isoprene has been studied in hexanes solution, while the reactivity of the germylene-Lewis bases complexes 37 and 44 with methanesulfonic acid and sodium hydroxide has been studied in methanol and THF solution. Dimerization of germylenes yields digermenes (Ar2Ge=GeAr2, DGa-g) and the reactivity of these species with diethylamine, acetic acid, and carbon tetrachloride has been examined. In addition to product studies, laser flash photolysis is used to generate and monitor these species over their lifetimes(< 20 μs) to determine absolute rate (k) and equilibrium (K) constants for the reactions. Aromatic substituent effects on k and K provide insight into the electronic demands of the transition state, while the effects of temperature on k and K leads to the activation and thermodynamic parameters, respectively.

Reaction of germylenes with acetic acid yields the corresponding 0-H insertion product ( 40); a two-step mechanism is proposed, Lewis acid-base complexation followed by proton transfer. Generation of germylenes in THF and MeOH leads to the immediate formation of the corresponding Lewis acid-base complex (37 and 44). In both solvents, the decay of the complex is accelerated by methanesulfonic acid but in neither case could evidence for a germyl cation be found. The decay of the germylene-MeOH complex (44) is accelerated by NaOMe; in one case a germyl anion (52) was detected. Reaction of germylenes with CC14 gives products consistent with halogen atom abstraction by the germylene. The data suggest a mechanism involving fast reversible germylene-CC14 complexation followed by a rate-determining dissociative inner-sphere electron transfer to yield the Ph2GeCl/CCh radical pair ( 60), whose primary fate is cage escape. Data on the reactions of 37 with CC14 in hexanes containing THF and neat THF are most consistent with a mechanism that yields an ion pair. Germylenes are scavenged by isoprene to form the vinylgermirane 24 as the kinetic product, while the germacyclopentenes 23 are the thermodynamic products. An-complex (77) prior to formation of 24 is proposed. It is believed that 23 forms from a (1 +4) cycloaddition reaction of the germylene with isoprene rather than a [1,3]-sigmatropic rearrangement of 24.

Digermenes react with acetic acid to yield products consistent with formal addition of acetic acid across the Ge=Ge bond; the kinetic data are consistent with nucleophilic attack by the carbonyl oxygen at germanium as the initial step in the reaction. Reaction of digermenes with CC14 gives the 1,2-dichlorodigermane. A double halogen atom abstraction mechanism, with the digermene behaving as an electron donor, is proposed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Determination of Triacylglycerols in Edible Oils by Infusion ESI/MS and ESI/MS/MS

contributor:
McCarry, B. E.
Chemistry and Chemical Biology

subject: triacylglycerols, edible, oils, ion, infusion, quadrupole, mass spectrometer, unsaturation, iodine

abstract:
 Edible oils consist primarily of triacylglycerols (or TAGs), which are triesters of glycerol and fatty acids. Determination of the TAG compositions of edible oils is becoming more important, given the economic value of these oil products and the increasing incidence of adulterating high quality oils with poorer quality oils. In this study we report the development of an analytical protocol using positive ion infusion electrospray mass spectrometry (ESI/MS) in conjunction with tandem mass spectrometry which affords both identification and quantification of TAGs in edible oils samples.

 This thesis reports a simple, comprehensive and quantitative method for the analysis of TAGs in edible oils in which the optimized method involves the infusion of an oil sample in chloroform:methanol (1:1) solution (~10-15 μg/mL of oil) in the presence of 0.5 mM LiCl. A sequence of corrections were applied to the raw peak area data of the TAG molecular ions, [M+Li]+, to account for: (1) normalization of peak area data using three internal standards, (2) peak area contributions of M+2 isotopic peaks of TAGs with one more degree of unsaturation and (3) peak area contributions of LiCl adduct ions, [M+Li+LiCl]+, when applicable. The major correction involved multiplication to a given TAG peak area by the appropriate electrospray relative response factor (RRF) for that TAG. The RRFs for all TAGs containing between 48 and 63 carbons in their fatty acyl chains and between 0 and 9 degrees of unsaturation were extrapolated from experimentally determined response factors of a series of standards. The RRFs were found to decrease by 6.7% for each additional acyl chain carbon but increased by 18.6% for each double bond. Comparison of these calculated RRFs to reported RRFs for a series of TAG standards showed an excellent correlation (1.06% ± 10.20% RSD).

 The use of Li+ in TAG analysis followed from the reports by Hsu and Turk [93] and Han and Gross [18] which showed that Li+ afforded more intense MS, and particularly MS/MS, spectra than either H+ or Na+. The enhanced intensities in MS/MS spectra (determined using a triple quadrupole mass spectrometer) were critical for the identification of TAGs, including the identity of the fatty acyl group located at the sn-2 position. However, this method cannot distinguish unambiguously between isobaric TAGs. This methodology was applied to the profiling of a number of edible oils including canola, olive, sesame, grape seed, walnut and hemp seed oils. The major TAGS in these samples contained 52, 54 and 56 carbons with between 0 and 11 degrees on unsaturation in a given TAG. There were minor amounts of TAGs containing 50, 55 and 57 carbons.

 The ability of this method to determine quantitatively the number of degrees of unsaturation in an oil sample was tested by examining a series of partially hydrogenated canola oil samples kindly provided by Bunge Canada. Five oil samples derived from a single feedstock with differing numbers of degrees of unsaturation, measured as iodine values, were subjected to our analytical method. The measured iodine values were compared to iodine values calculated from the number of degrees of unsaturation obtained by our MS-based method. The slope of this correlation was 1.10 with an R^2 = 0.995. Overall, this method is much simpler and more accurate than the protocol described by Han and Gross [18]. This methodology will be applied as routine method for the analysis of TAGs in biological samples such as blood samples.

abstract: Thesis

abstract: Master of Science (MSc)


contributor:
Janicki, Ryszard
Computing and Software

abstract: Title: Non-Numerical Ranking Based on Pairwise Comparisons, Author: Yun Zhai, Location: Mills

abstract:
The method of Pairwise Comparisons was first described by Marquis de Condorcet in 1785 [1]. At present, this method is identified with Saaty's Analytic Hierarchy Process (AHP, 1980) [25]. AHP is a formal method to derive ranking orders from pairwise comparisons. It is used around the world in a wide variety of decision making, in fields such as education, industry, and government.

On the one hand, AHP has many respected practical applications. On the other hand, however, it is still considered by many researchers as a flawed procedure that produces arbitrary rankings [6].

A non-numerical partial orders based method was proposed by Janicki and Koczkodaj [14] and developed by Janicki [9, 10, 11, 12, 13]. This model used the concepts of partial orders and rough sets, and emphasized the importance of indifference and weak ordering. However, the consistency rules of the model are incomplete. When the inconsistent pairs are found, the non-numerical ranking method manually changes the relationship among those pairs to satisfy the consistency rules.

We extend the consistency rules to make them complete and compact. A consistency-driven algorithm by automatically enforcing "consistency" is presented. Property-driven algorithms by classical partial order approximations and refined partial order approximations are discussed. We present an algorithm using refined partial order approximations. A method of automatically converting AHP data to nonnumerical pairwise comparison ranking system is discussed, which ensures that the generated non-numerical pairwise comparison ranking system is consistent.

We implement various ranking algorithms, including the AHP method, consistency-driven method, property-driven method and property/consistency-driven method. We test the experiments referenced in some non-numerical ranking papers, and give examples to compare how well the various non-numerical ranking methods solve the rank reversal problem.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Genesis of an Archaean Quartz-Feldspar Porphyry

contributor:
McNutt, R. H.
Geology

subject: genesis, archaean, quartz-feldspar, porphyry, fine-grained

abstract: Three conformable units of fine-grained quartz-feldspar porphyry were mapped in the Berry River Formation, Warclub Group, Northwestern Ontario. The largest unit (Unit 1) is compared geochemically and petrographically to quartz-feldspar porphyry intrusions and tuffs in the area with the aim of determining the method of emplacement of the porphyry unit (Unit 1), and consequently the other two units.

abstract: Thesis

abstract: Bachelor of Science (BSc)


contributor:
Cassidy, Daniel T.
Engineering Physics

abstract: Title: Study of Outputs Power of Broadly Tunable InGaAsp/InP AMQW Lasers, Author: Hesham Enshasy, Location: Mills

abstract:
Broadly tunable InGaAsP/InP asymmetric multiple quantum well (AMQW) ridge waveguide laser diodes suffer from low output power. The output power problem of the AMQW laser diodes limits the use of these lasers in certain applications. Both theoretical and experimental studies were carried out in this work to understand the reasons behind this output power problem and to put forth solutions to this problem. As a starting point a commercial beam propagation method (BPM) optical simulator was used to optimize the confinement factor of the laser diodes. The laser diode output power almost doubled as a result of optical confinement optimization, which opens the door for improvement from electrical and thermal optimization.

A commercially available partial differential equation solver, FlexPDE, was used to solve the main electronic and thermal equations and simulate a laser diode device. The FlexPDE simulations -which were validated with published data-showed poor current injection efficiency to the center of the device active region. The FlexPDE simulations showed that the main reason for this poor current injection efficiency is the ridge structure. Since the ridge structure is an essential part of this type of laser diode, effort was put forth to reduce the effect of the ridge structure on the current injection efficiency. Both simulation and experimental data showed that extending the doping profile closer to the active area would improve significantly the output power. On the other hand, a proposed forced electrical confinement method showed potential to improve the output power of the device theoretically and experimentally. The over all output power improvement went from a range of 2-5 m W to a range of 15-18 m W as a result of this study. A discussion of the two distinct output power profiles is included in the study, while detailed explanations of the dip in the power profile supported by experimental data are reported.

A new method of distance measurement using one of the first, optimized, broadly tunable InGaAsP/InP short-external-cavity diode lasers is reported. Non-linear, least squares fitting method was used to extract estimates of distance from the raw data. This fitting method together with the wide tuning range (100 nm) made it possible to achieve sub-micron resolution of distance even in the presence of noise.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Deltor, Brian
Business Administration

abstract: Title: Socio-Technical Determinants of Member Participation in Virtual Communities: An Exploratory Mixed Methods Investigation, Author: Umar Ruhi, Location: Mills

abstract:
The recent unprecedented growth of virtual communities on the Internet has provided an impetus for researchers and practitioners to investigate factors that facilitate or encumber member participation in these communities. As interactive online spaces, virtual communities have the potential to enable high levels of information sharing, communication and social interactions among their members. Despite the crucial realization that engaging and involving members constitutes a fundamental requirement for successful and thriving virtual communities, research done to date to study the factors affecting member participation behavior is still in its infancy. The goal of this study is to identify and ascertain the sociological and technological factors for enhancing and sustaining member participation in virtual communities. Toward this objective, the study utilizes an exploratory mixed methods research design to collect and analyze qualitative and quantitative data from members of various social, professional and commercial virtual communities.

Qualitative data for the empirical investigation was gathered through online focus groups and open-ended questionnaires. Using principles and procedures associated with grounded theory methodology, this study presents an emergent theory characterizing the member engagement process as an underlying phenomenon integrating various socio-technical factors that influence member participation behavior. The subsequent phase of quantitative investigation deliberates the testing of salient theoretical constructs and relational propositions from the emergent theory. Exploratory factor analysis and structural equation modeling techniques were used to estimate a structural model of relationships among socio-technical determinants of member participation in virtual communities. The quantitative results provide a strong substantiation of the qualitative findings through triangulation and elaboration of the constructs and their interrelationships in the emergent theory.

The key findings from this study emphasize the role of factors such as information quality, member responsiveness, member trustworthiness, and perceived enjoyment in determining continued and active participation in virtual communities. The findings also illustrate the salience of perceived satisfaction and sense of virtual community in predicting members' participation. Based on these findings, this study offers theoretical implications and suggestions for future research, as well as guiding principles and actionable recommendations for virtual community practitioners.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Nd Model Age Mapping of the Central Grenville Province in the Lac St. Jean Region, Quebec

contributor:
Dickin, A. P.
Geology

subject: model, age mapping, Central Grenville Province, neodymium, isotope, formation, rocks, continental, lithological, region

abstract:
 Detailed Neodymium ( Nd ) and Lead ( Pb ) isotopic mapping was performed on gray gneisses from the Lac St. Jean region of Quebec, in the Central Grenville Province. The Nd model ages determined were based upon the Depleted Mantle Model of DePaolo  ( 1981c ). The use of this model is justified by a Sm-Nd whole-rock isochron as well as common Pb-Pb whole-rock dating.

 The field area was divided up into three sections: Western, Central, and Eastern. The boundaries of these divisions corresponded to abrupt changes in Nd model ages. The Western section was located in the Parautochthonous Belt of Rivers et al.,     ( 1989 ) and almost exclusively consisted of tonalitic gray gneisses with Archean Nd model ages. Whole-rock Pb isotopic analyses produced a Transposed Palaeoisochron, implying that the rocks of the Western section were significantly affected by the Grenville event approximately 1.1 Ga ago. Major and trace element analyses indicate that the Western section represents an arc and may be the exhumed basement of the Abitibi Volcanic Belt to the north, consistent with previous work by Ciesielski ( 1992 ).

 In contrast to the Western section, the Central section which is separated from the Western section by the Allochthon Boundary Thrust of Rivers et al., ( 1989 ) has a very wide range of Nd model ages from 1.65 Ga to 2.35 Ga. The temporal and spatial range of Nd model ages, coupled with major and trace element analyses, indicates that the Central section represents an Andean style ensialic continental margin arc. The diapirs that reworked these rocks contain varying amounts of Archean material implied by the Early-Proterozoic Nd model ages of some samples, particularly in regions close to the Allochthon Boundary Thrust. Whole-rock Pb isotopic analyses produce a Transposed Palaeoisochron indicating significant U depletion caused by the Grenville orogeny.

 The Eastern section is composed almost exclusively of gneisses with Nd model ages of ca. 1.5 Ga. The boundary between the Central and Eastern sections is based solely on lithological differences and an isotopic age break form the variable Nd model ages of the Central section, to the consistent model ages of the Eastern section. A Sm-Nd isochron for all samples with ca. 1.5 Ga Nd model ages produces an age of 1.50 +/- 0.07 Ga, in close agreement with previous work ( Dickin and Higgins, 1992 ). The consistency of model ages ( > 100,000 Km^2 when combined with data from Dickin and Higgins, 1992 ) coupled with major and trace element analyses, indicates the presence of an island arc which formed at ca. 1.5 Ga and was sutured on to the Laurentian craton within 100 Ma of its formation.

 Whole-rock Pb isotope analyses indicate that the Eastern section was not affected by the Grenville event as much as the Central or Western sections were.

 Pb-Pb zircon dating for samples from the Central and Eastern sections failed to place a tight constraint between crystallization ages and Nd model ages because of excessive Pb loss.

abstract: Thesis

abstract: Master of Science (MSc)


title: A Kimberlite, Its Mineralogy, and Implications

subject: kimberlite, mineralogy, implications, diatremes, genetic, limestone

abstract: Kimberlite diatremes from a single genetic source were examined. Macrocryst and groundmass constituents were identified, as well as their alteration products. It was hypothesized that carbon dioxide and water vapour were present at the time of formation. Limestone inclusions and peridotite xenoliths were examined, as well as fabrics within the xenoliths. It was concluded that water is present in the upper mantle. Ilmenite nodules were determined to be phenocrysts, as opposed to xenocrysts. A paragenetic sequence for the kimberlite was resolved. Ilmenite was classified as the best indicator mineral for exploration purposes.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Triassic Braided Gravelly River Deposits at Pt. Lepreau, New Brunswick

contributor:
Middleton, G. V.
Geology

subject: triassic, braided, gravelly, river, deposits, formation, sandstones, mudstones, breccia

abstract:
 A detailed section of the Duck Cove Member (Nadon, 1981) of the Triassic Lepreau Formation of Southern New Brunswick is measured.

 The section consists of a complex sequence of conglomerates and sandstones with a minor occurrence of mudstones and breccia. A description of the facies is provided and an interpretation is based on observations of ancient and marine braided stream deposits of Miall (1978) and Allen (1983). The Markov chain analysis is used to describe the vertical succession of facies.

 Paleoflow indicators suggest a flow towards the south or southeast. However this conclusion is based on limited availability of data.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: The Origin and Tectonic Setting of Tow Hill, Queen Charlotte Islands

contributor:
Clifford, P. M.
Geology

subject: tectonic, Tow Hill, Islands, Queen Charlotte, tholeiitic basalt, transtension

abstract: Tow Hill is a 109m butte located on the north shore of Graham Island, Queen Charlotte Islands. It is composed of a massive, 105m thick layer of olivine tholeiite, underlain by thin sills of tholeiitic basalt and interbedded sediments of the Skonun Formation. The age of this basalt body has been estimated to be less than 5Ma. Three hypotheses have been proposed as to the origin of Tow Hill: 1. a sill intrusion; 2. hydroclastic material; and 3. a lava flow or flows. Macroscopic features observed on Tow Hill do not indicate an origin and each of the three hypotheses can adequately explain the features. Petrographical studies indicate that the basalt is not fragmental and thus, the second hypothesis can be rejected. Neither of the two remaining hypotheses can be strictly accepted or rejected with petrographical examination. Chemical analyses indicate that Tow Hill is made up of "within plate" basalts which are probably related to activity associated with rifting and/or transtension in a continental environment. This constrains the late Tertiary tectonic history of the Queen Charlotte Islands in that any model of the tectonics of this area must involve rifting and/or transtension.

abstract: Thesis

abstract: Bachelor of Science (BSc)


contributor:
Eilers, C.
Classics

abstract: Title: The Greek Freedom and Roman Hegemony: The Transaction of Roman rule in the Greek East (201 BCE - 14CE), Author: Michael Snowdon, Location: Mills

abstract:
This study investigates the nature, operation and development of Roman rule in the Greek East during the second and first centuries BCE through the communications between
states preserved in the epigraphic record. Using Roman senate decrees, letters of
magistrates and laws, and Greek civic decrees, it addresses the questions of how the
Romans and their Greek subjects mutually understood Roman rule and why the Greeks,
whose political traditions valued autonomy, came to accept subordination into the
Romans' imperial state. An investigation into the provincial system of the Roman empire
- the institutional and administrative apparatus of the imperial state - reveals its limited
arrangement and reliance to a great degree on local civic autonomy. In fact, the
documents of state demonstrate the broader significance of freedom in Greco-Roman
relations: more than simply propaganda or political sloganeering, it was a central political
discourse whose normative values and rules circumscribed relations between Rome and
the pole is of the East, complementing the limited structural arrangement of the empire
itself, while also directing and constraining the actions of ruler and ruled. These actions
are preserved in the state documents - actual artifacts of the transaction of empire - and
reveal a dynamic, interactive empire. With reciprocity as the mode of interaction, this
interactive empire operated through interstate benefactions, and social relationships like
friendship and patronage that allowed Greek cities to negotiate their positions with Rome
and de-problematize Roman authority as consistent with the traditional autonomy of the
polis. Through these communications, the Romans and Greeks reached a consensus
about the nature and operation of their relationship such that a Greek city-state in the first
century could rationally declare war on behalf of both Roman hegemony and Greek
freedom.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


contributor:
Reed, Annette Y.
Religious Studies

abstract: Title: Assessing the Virgin: Gender and Purity in the Protevangelium of James, Author: Lily Vuong, Location: Mills

abstract:
My dissertation brings literary approaches to the study of purity in one of the most
influential "apocryphal" texts about Mary the mother of Jesus. Specifically, I explore the
place and function of ritual, menstrual, and sexual purity in the portrayal and
characterization of Mary in the Protevangelium of James. In the narrative, Mary's
exceptional ritual and sexual purity serves to set her apart as a woman unique and holy,
but I argue that her ability to menstruate allows for reconnection with, and accessibility
to, other women. Indeed, literary exploration into Mary's menstrual purity reveals the
author's view that motherhood is to be praised alongside ascetic virginity. In addition, I
also re-examine questions about the date and provenance of the text through its focus on
purity, proposing that its narrative and ritual concerns are most fitting with a late second
to early third century date and a West Syrian cultural context. By tracing the various ways
purity is described and presented in the text, this study sheds light on early Jewish and
Christian ideas about purity, representations of women in the ancient world, the early
history of Mariology, and the place of non-canonical writings in the history of biblical
interpretation.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Composition and Origin of Jurassic Ammonite Concretions at Gerzen, Germany

contributor:
Westermann, G. E. G.
Geology

subject: composition, origin, Jurassic, Ammonite, concretions, Gerzen, Germany, fossils, sediments

abstract:
 Study of the ecology of concretion and host sediment fossils from a shell bed in middle Bajocian clays of northwestern Germany indicates a predominantly epifaunal suspension-feeding community living on a firm mud bottom. The shell bed, firm bottom and low turbidity required by suspension feeders suggests a hiatus or reduced sedimentation at the time. Depth estimates of 50 to 150 m are indicated by ammonite and belemnite siphuncle and septal strength indices.

 Preservation of calcitic fossils is excellent in both concretions and host sediments. Aragonitic fossils show good preservation in the concretions. Aragonite has been replaced by at least two generations of calcite. Preservation in the host sediments is poor. Pyrite is common in void spaces of concretion fossils but less so in those from the host
sediments.

 Eight concretions were studied, containing numerous Stephanoceras mutabile (macroconch) and Stephanoceras quenstedti (microconch). These are of opposite sexes but are not a dimorphic pair.

 Distribution of shell debris and other fossils within the concretions suggests that the ammonites were swept by currents into shallow depressions in the sea floor lined with shell debris. Such depressions have been observed in modern sediments as the result of the feeding activity of rays. The presence of currents is indicated by the southwest orientation of belemnite rostra in the host sediments. Carbonate content of concretion matrix is high indicating concretion growth in very fluid muds. This contrast with the firm bottom indicated by fossil ecology suggests rapid burial of the benthic community by either a mudflow or a sudden, large increase in sedimentation. Concretion growth was initiated by decomposition of organic matter within the mud.

abstract: Thesis

abstract: Master of Science (MSc)


contributor:
Schrobilgen, Gary J.
Chemistry

abstract: Title: Nobel Gas Chemistry Derived from N≡SF3 and Related Sulfur-Nritrogen-Flourine Chemistry, Author: Gregory L. Smith, Location: Mills

abstract:
The chemistry of xenon(II) has been significantly extended by the syntheses and
characterizations of new examples of xenon bound to nitrogen having formal sp, sp2, and sp3 hybridization, namely the F3S≡NXeF+, F4S=NXe+, and F5SN(H)Xe+ cations. The
F4S=NXe---N≡SF3+ adduct-cation is the first example of an N-Xe-N linkage to be
structurally characterized by X-ray crystallography. Until recently, all of the known
compounds containing xenon bound to formally sp-hybridized nitrogen have been
prepared using organic nitrogen bases. The inorganic nitrogen Lewis base thiazyl
trifluoride, N≡SF3, was reacted with the AsF6- salt of the Lewis-acidic XeF+ cation at
-20 °C to synthesize the donor-acceptor adduct [F3S≡NXeF][AsF6]. Displacement of
XeF2 from [FXeOXeFXeF][AsF6] by N≡SF3 at -60 °C led to the formation of the
FXeOXe---N≡SF 3 + adduct-cation, providing a rare example of a xenon(II) oxide fluoride,
which was characterized by Raman spectroscopy of natural abundance and 180-enriched
salts. The solid-state rearrangement of [F3S≡NXeF][AsF6] at 22 °C yielded
[F4S=NXe][AsF6], which was characterized by Raman spectroscopy. This is the first
example of xenon bonded to an imido-nitrogen and the first example ofthe F4S=N- group
bonded to a noble gas. The HF solvolysis of [F3S≡NXeF][AsF6] at -20 °C in aHF or BrF5
solvents generated [F5SN(H)Xe][AsF6], which, in addition to F5TeN(H)Xe+, provides the
only other example of xenon bonded to an sp3 -hybridized nitrogen centre.

Through further study of the HF solvolysis of [F3S≡NXeF][AsF6] in aHF or BrF5
solutions, it was shown that the F 4S=NXe+ cation was also formed, and may be understood in terms of an HF -catalyzed mechanism. The F 4S=NXe + cation subsequently
underwent HF solvolysis, forming F4S=NH2+, XeF2, and F5SN(H)Xe+. Both cations
underwent further HF solvolyses to form the F5SNH3+ cation. The F4S=NXe+ and
F4S=NH2+ cations were characterized by NMR spectroscopy and single-crystal X-ray
diffraction, and exhibit high barriers to rotation about their S=N double bonds. They are
the first cations known to contain the F4S=N- group, significantly extending the
chemistry of this ligand. The rearrangement of [F3S≡NXeF][AsF6] in N≡SF3 solution at 0
°C yielded [F4S=NXe---N≡SF3][AsF6], which was characterized by Raman spectroscopy
and X-ray crystallography.

Solvolysis of N≡SF3 m aHF is known to give the primary amme, F5SNH2, whereas solvolysis in the superacid medium AsF5/aHF results in amine protonation to give [F5SNH3][AsF6]. Until recently, definitive structural characterizations were not known for either of these fundamental species. Isolation of F5SNH2·nHF from the
reaction of N≡SF3 with HF has provided a structural characterization of F5SNH2 by
Raman spectroscopy. Crystal growth by sublimation of F5SNH2·nHF at -30 to -40 °C
provided single crystals of F5SNH2·2[F5SNH3][HF2]·4HF, and recrystallization of
[F5SNH3][AsF6] from N≡SF3 solution at -70 °C afforded crystalline
[F5SNH3][AsF6]-2N≡SF3 and resulted in the structural characterization of these salts by
X-ray crystallography. The redox decomposition of [F4S=NXe---N≡SF3][AsF6] in N≡SF3
at 0 °C generated Xe, cis-N2F2, and [F3S(N≡SF3)2][AsF6] which was characterized by
Raman spectroscopy and single-crystal X-ray diffraction. These X-ray crystal structure
determinations, in themselves, represent a significant extension of sulfur-nitrogen-fluorine chemistry, providing the first definitive characterizations of F5SNH2 and
FsSNH3+, only the second known example of unadducted N≡SF3, and rare examples of
main-group coordination compounds of N≡SF3.

The F5SNH3+ cation protonated CH3CN to CH3CNH+ which is proposed to initiate the cyclotrimerization of CH3CN, generating F5SNH2 and [s-C3(CH3)3N3H][AsF6], as characterized by NMR spectroscopy at -10 °C in CH3CN solvent. Crystal growth from CH3CN at -10 to -35 °C enabled the determination of the X-ray crystal structure of [s-C3(CH3)3N3H---NCCH3][AsF6]-CH3CN. This represents the first known crystal structure of a sym-2,4,6-trialkyl-1 ,3,5-triazinium cation.

The final objective of this research was to extend the chemistry of krypton-nitrogen bonded species. The nitrile cations RC≡NKrF+ (R = H, CF3, C2F5, n-C3F7) are
currently the only known examples containing Kr-N bonds. The syntheses of the
F3S≡NKrF+ and F5SN(H)Kr+ cations as their AsF6- salts were attempted by the reaction
ofKrF2 with F3S≡NAsF5 and [F5SNH3][AsF6], respectively, for characterization by NMR
spectroscopy in BrF5 solvent at -70 to -60 °C. No conclusive evidence for Kr-N bond
formation was found, however, in each case, the fluorination and oxidation products SF6,
NF3, NF4+ and AsF6- were observed instead.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


abstract: Title:Flouride Ion Donor-Acceptr Properties of cis-OsO2F4 and Lewis Acid Properties of OsO3F2 and XeOF4, Author: Michael J. Hughes, Location: Mills

abstract:
Reaction of cis-OsO2F4 with the strong Lewis acid, SbF5, yields
[cis-OsO2F3][Sb2F11] which has been characterized by single crystal X-ray
crystallography and low-temperature Raman spectroscopy. The structure of the salt
consists of a closely associated ion-pair in which a fluorine atom from the anion
coordinates to the cation rendering the osmium atom pseudo-octahedral. Reaction of
cis-OsO2F4 with the fluoride ion sources [M][F] (M = Cs+ and N(CH3)4+) yielded the
corresponding salts of the OsO2F5- anion. The structure of this anion was studied by
Raman spectroscopy and 19F NMR spectroscopy which revealed that the geometry of the
anion is a cis-dioxo monocapped trigonal prism. The anion represents a rare example of a
d0 seven-coordinate species. Attempts to obtain the crystal structure of this anion,
however, proved unsuccessful. Dissolution of [M][OsO2F5] in CH3CN and subsequent
crystal growth yielded crystals of cis-OsO2F4 · [M][ CH2CN]. The structure represents the
first examples of an isolated CH2CN- anion, formed by a fluoride ion from cis-OsO2F5-
abstracting a proton from the CH3CN solvent to give cis-OsO2F4, CH2CN- and HF. In a
separate crystal growth, crystals of cis-Os02F4 were grown by sublimation from an XeF6
melt. Together with the structures of cis-OsO2F4·[M][CH2CN], the cis-OsO2F4 structure
represent the first examples of non-disordered crystal structures of cis-OsO2F4·

Dissolution of the fluorine bridged polymer jac-(Os03F2)co in XeOF4 at room
temperature resulted in a new phase of OsO3F2, namely the fluorine bridged dimer
(OsO3F2)2. The crystal structure of the dimer grown from XeOF4 solvent contains two
adducted XeOF4 molecules which coordinate to the terminal fluorines of the dimer (one per osmium atom) to give a structural unit formulated as (OsO3F2)2·2XeOF4. Both
osmium atoms are six-coordinate with a fac-trioxo arrangement. Further removal of
XeOF4 under dynamic vacuum yields only the dimer which was characterized by Raman
spectroscopy and rearranges to the open chain polymeric structure of fac-OsO3F2 when
warmed to room temperature. When CH3CN is used as a solvent, the nitrogen atom
adducts to (OsO3F2)∞ to form OsO3F2(NCCH3). In SO2ClF solution both the fac- and
mer-isomers are observed by 19F, 15N, and 1H NMR spectroscopy, while only the
fac-isomer is present in the solid state.

Stoichiometric amounts of XeF6 and (OsO3F2)∞ react to form the [XeF5][μ-F(OsO3F2)2], [XeF5][OsO3F3], and [Xe2F11][OsO3F3] salts. The series provides the first examples of noble-gas cations that are stabilized by metal oxide fluoride anions, and the first example of a μ-F(OsO3F2)2- salt. The osmium atoms in all three salts are six-coordinate with fac-trioxo arrangements. The anions and cations of each ion pair are highly associated through fluorine bridges from the anion to the cation rendering the
coordination spheres of the xenon atoms in the [XeF5][μ-F(OsO3F2)2] and
[Xe2F11][OsO3F3] salts 9-coordinate, while for the [XeF5][OsO3F3] salt it is 8-coordinate.
The [XeF5][μ-F(OsO3F2)2] salt is unique in that it provides the first example of a
9-coordinate Xe atom where all contacts originate within a single ion-pair.

The molecular addition compounds, XeOF4·NgF2 (Ng = Kr or Xe), have been
synthesized by dissolution of NgF2 in XeOF4 solution. The crystal structures of these
addition compounds are similar, with the NgF2 molecules coordinating to the open face of
the square pyramidal XeOF4 molecule. The coordination spheres of the xenon atoms of the XeOF4 molecule in both structures are 9-coordinate. For XeOF4·XeF2 all of the
contacts are to four symmetrically equivalent XeF2 molecules, whereas for XeOF4·KrF2
contacts are to two symmetrically equivalent KrF2 molecules, one crystallographically
independent KrF2 molecule, and one to an adjacent Xe0F4 molecule. The XeOF4·KrF2
adduct provides the first example of a mixed noble gas adduct.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: ROLE OF IL-1α IN IgG1 MEDIATED ANAPHYLAXIS

contributor: Medical Sciences (Molecular Virology and Immunology Program)

abstract:
BACKGROUND: There is growing evidence indicating that skin can be an initiating site for allergic sensitization to peanut. Additionally, anaphylaxis can also be mediated by IgG1 and macrophages, known as the alternative pathway. In this setting, the allergen binds to serum IgG1 forming immune complexes which can bind to macrophages, basophils and neutrophils and cause the release of anaphylactic mediators.
METHODS: The model of epicutaneous sensitization used in this study relied on tape stripping the skin followed by direct application of peanut. Knockout mice and/or antibody neutralization studies were used to characterize anaphylaxis in this model. For the in vitro experiments, we used either peritoneal or bone marrow derived macrophages. We also collected samples from mice undergoing anaphylaxis at different time points to measure mediators involved.
RESULTS: We found that anaphylaxis in this model of epicutaneous sensitization was dependent on IgG1, macrophages and PAF but not IgE, mast cells, basophils, neutrophils, monocytes and histamine. Additionally, IL-1α was critically required for anaphylaxis. Interestingly, this role was intracellular as both anti-IL-1α treatment and a deficiency in IL-1R failed to prevent anaphylaxis. Using macrophage cultures, we found that the activity of cPLA2, the enzyme responsible for PAF production, was intact in the absence of IL-1α. Likewise, the activity of PAF-AH, the enzyme that degrades PAF, was also unaffected in IL-1α-/- mice. We also showed that PAF signalling was intact in IL-1α-/- mice. Lastly, we showed that MDR1, the transporter for PAF was not critical for anaphylaxis in this model.
CONCLUSION: We developed a model of skin sensitization in which anaphylaxis was driven by IgG1, macrophages and PAF. We identified intracellular IL-1α as a critical component of the alternative pathway of anaphylaxis. We also showed that this effect is not related to defects in PAF metabolism or signalling. This allows us to direct the focus on other pathways affected by IL-1α in our future studies.

abstract: Thesis

abstract: Master of Science (MSc)


title: Bioerosion and Micritization in the Deep Sea: A Look at the Coral Desmophyllum cristagalli

contributor:
Risk, M. J.
Geology

subject: bioerosion, micritization, deep sea, coral, desmophyllum cristagalli, skeletons, substrate, carbonate, dissolution

abstract:
 An assemblage of coral skeletons of the species Desmophyllum cristagalli were obtained from the top of Orphan Knoll, 550 km northeast of Newfoundland, from depths of approximately 1600 and 1800 m. The corals were observed for their macro- and micro-boring assemblages, and the boring morphologies documented, using binocular and scanning electron microscopy. Samples of coral were embedded with resin and etched for examination of the micro-boring assemblages.

 The largest volumetric amount of skeletal material removed was by sponges forming Entobia. This further corroborates the assumption that various species of boring sponges are distributed ubiquitously throughout a wide bathymetric range.

 Four distinct fungal forms were found, two tubular forms interpreted to be hyphal filaments and two bulbous forms interpreted to be sporangia. These forms were described on the basis of their shape, size, mode of branching, association with other structures and texture. They were then compared to other micro-boring assemblages found in previous studies from various bathymetric ranges. Some forms described in this study were found to be similar to forms described in other studies. Other forms in this study were not found to be documented. It is suggested, therefore, that certain forms, as well as low ichnodiversity, may indicate deeper water environments.

 Destructive micritization structures were also found in resin casts as well as in thin section. The extent of micritization may indicate the intensity of the parameters at the substrate that affect carbonate dissolution, such as CaCO3 and CO2 concentrations, pH, temperature, and salinity. It would therefore indicate the ambient water conditions at the substrate. If a sufficiently large database could be obtained, as well as distinct separation of the parameters responsible for carbonate dissolution, micritization may be used in a mapping of the carbonate compensation depth through time and depth ranges.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Synthesis and Characterization of Superparamagnetic Iron Oxide-Alginate Hydrogels and Fluid

contributor:
Winnik, F. M.
Chemistry

subject: synthesis, characterization, superparamagnetic, iron, oxide-alginate, hydrogels, fluid, polymer, particles, degradation

abstract:
 Aqueous ferrofluid has been prepared via precipitation of iron oxide into a polysaccharide gel matrix followed by degradation of the polymer to form a stable magnetic colloid. Nanocrystalline particles of iron oxide were formed in an alginate network by the alkaline hydrolysis and oxidation of the crosslinking agent, Fe2+, used to bind the linear polysaccharide chains. Methanol was used to inhibit the degradation of alginate by Fe2+ and oxygen during the precipitation and growth of iron oxide particles. In addition, the structural integrity of the gel was maintained in part by interaction between the iron oxide particulate and the alginate matrix. Controlled chemical degradation of the matrix resulted in a aqueous suspension of alginate-stabilized magnetic iron oxide particles. The resulting fluid is orange-brown in color, optically transparent, superparamagnetic and stable between 2.8<pH<10

 The magnetic gels were isolated as 2mm beads containing ~2-20 mmole Fe. X-ray
and electron diffraction patterns of the composite correspond to maghemite (γ-Fe2O3)
and/or magnetite (Fe3O4). At room temperature, the composite material is superparamagnetic with saturation magnetizations in excess of 20 emu g^-1 at 30kOe. TEM photomicrographs of sectioned beads and of the magnetic fluid revealed the presence of spherical nanocrystalline oxide particles with diameters ranging from 3 nm to 6 nm. The iron oxide-alginate colloid has a diameter of 54nm with an average zeta potential of -51.6 mV.

abstract: Thesis

abstract: Master of Science (MSc)


title: PDMS/PNIPAAM Interpenetrating Polymer Networks as Ophthalmic Biomaterials

contributor:
Sheardown, H.
Chemical Engineering

subject: interpenetrating, polymer, networks, ophthalmic, biomaterials, oxygen, temperature, glucose, permeability

abstract:
 Poly (dimethyl siloxane) (PDMS) has been widely used as a biomaterial in ophthalmic and other applications due to its good compatibility, high mechanical strength and excellent oxygen permeability and transparency. For use as an artificial cornea, contact lens and in other applications, modifications are necessary to improve glucose permeability and wettability for cell and tear protein and mucin interactions through modification with hydrophilic functional groups or polymers. Poly (N-isopropyl acrylamide) (PNIPAAM) is a biocompatible and hydrophilic polymer that has been extensively studied in controlled drug release applications due to its lower critical solution temperature (LCST) phenomenon. In this study, a composite interpenetrating polymer network (IPN) of PDMS and PNIPAAM was formed to generate material with reasonable oxygen and glucose permeability as well as improved wettability and mechanical properties compared to the PDMS and PNIPAAM homopolymers.

 Semi-IPNs, with low water uptake and mechanical strength, were found not to be
suitable as biomaterials. Vinyl terminated PDMS/PNIPAAM IPNs had reasonable water
uptake and excellent tensile stress and strain, but low glucose permeability (< 10^-10
cm^2/s). Hydroxyl terminated PDMS/PNIPAAM IPNs (PDMS-OH IPN) were successfully synthesized with reasonable mechanical properties and significantly higher glucose permeability (~10^-7 cm^2/s). Curing the PDMS-OH film with solvent was found to improve glucose transport.

 The presence of PNIPAAM in the composite networks was confirmed by FT-IR and Differential Scanning Calorimetry (DSC). Transmission Electron Microscopy (TEM) images verified the structure of interpenetrating networks. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and X-ray Photoelectron
Spectroscopy (XPS) suggested that PNIPAAM was also present on the surface and this
translated to increased roughness compared with the PDMS control as determined by
AFM. The LCST phenomena still remained in the IPN, although the change was not as
abrupt as with pure PNIPAAM. These results suggest that the copolymer may be useful
as an ophthalmic biomaterial and for controlled drug release applications.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Growth Cycles and Paleoecology of Devonian Rugosa

subject: growth, cycles, paleoecology, Devonian Rugosa, monthly, corallite, water, population, skeletal debris

abstract:
 Solitary rugose corals of the Middle Devonian Hungry Hollow Formation exhibit annual, synodic month and periodicities of their epithecal growth lines. Annual cyclicity is poorly developed due to the slight seasonal variation of the 33°S paleolatitude. Thirteen monthly bands each with a mean of 30.38 diurnal lines comprise a Middle Devonian year of approximately 395 days. Corallite measurements yielded a monthly vertical growth rate of .377 cm. A major correlative reduction in monthly growth is apparent at approximately seven monthly bands from the apex. Environmental deterioration probably accounts for this reduction and the randomly occurring disturbance lines visible on the epithecae. Random periods of rejuvenescence in which the corallite diameter is reduced may be linked to abnormal environmental conditions. Bryozoan larvae actively settled on corallite areas which provided shelter from abrasion, water currents and light. The growth of the corallites is anisometric and exhibits no apparent relationship between monthly growth rate and diameter increase.

 The frequent occurrences of geniculate corallites in the sample are indicative of occasionally turbulent water conditions that toppled the immature corallites. Storms probably created turbulence that toppled much of the coral population with heights of 2.0-4.0 cm and resulted in subsequent geniculation. An exceptionally violent storm probably destroyed the shallow epicontinental sea habitat of the rugosa by intense wave action. The skeletal debris was transported inland and deposited unconformably on the lime mud of the carbonate platform. When conditions normalized, lime mud was deposited onto the fossiliferous shale unit.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Geophysical Response of Sulfide-Poor PGM-Bearing Mafic-Ultramafic Rocks: Example of the Boston Creek Flow, Abitibi Greenstone Belt, Ontario

contributor:
Morris, W. A.
Crocket, J. H.
Geology

subject: geophysical, sulfide-poor, mafic-ultramafic, rocks, Greenstone, belt, mineralization, platinum-group, magnetite-rich

abstract:
 Sulfide-poor platinum-group element (PGE) mineralization occurs within the Archean
Boston Creek Flow ferropicrite, Abitibi greenstone belt, Canada. The PGE mineralization
(∑PGE+Au = up to 1000 ppb) is manifest as metre-scale platinum-group mineral-bearing
pods of disseminated chalcopyrite and pyrite (< 1 modal%) within titaniferous magnetite-rich
gabbroic rock at the base of its central gabbroic layer. This mineralization is distinct in
character from well known PGE mineralization associated with massive Fe-Ni-Cu sulfides at
the base of komatiite flows at Kambalda, Western Australia and elsewhere. Exploration
strategies presently used to search for PGE in mafic and ultramafic volcanic rock terrains are
based on the geological and geophysical characteristics of sulfide-rich PGE mineralization.
Consequently, refinements in exploration strategies are required if economic concentrations
of sulfide-poor PGE mineralization are to be discovered in volcanic terrains.

 To begin development of such exploration criteria, ground-based magnetic and VLF surveys were conducted over the PGE mineralization along a single cross-section through the BCF. Drill core samples were collected along this transect to characterize the volume magnetic susceptibility and natural remanent magnetization (NRM) of the mineralization. Magnetic highs ranging in intensity from 64000 to 65000 nT were recorded for the base of the gabbroic layer, including mineralized outcrops. Susceptibilities of up to 9700 cgs and high remanence values with variable directions were determined. VLF, as expected, was not useful in identifying the mineralized horizons. The peridotite at the base of the flow appears to be the only conductive rock in the BCF.

 The magnetic highs associated with the base of the gabbroic layer define a positive anomaly that appears to be podiform in outline and up to ten metres in maximum dimension. This result suggests that the titaniferous magnetite-rich rock is itself podiform, like the enclosed PGE mineralization. This magnetic anomaly is not extensive enough to be evident on a regional scale aeromagnetic map as a separate anomaly within the BCF, and is not evident through VLF techniques. The rocks hosting the PGE mineralization is defined by the paleomagnetic results but this is not a practical field method.

 The geophysical characterization of the PGE mineralization host rocks, and of the BCF in general, demonstrates the potential of detailed magnetic and susceptibility mapping, together with petrographic and petrologic studies, in the search for economic PGE concentrations of sulfide-poor PGE mineralization in other volcanic and possibly plutonic rocks as well. Specifically, the results suggest that podiform magnetic anomalies within titaniferous magnetite-rich pyroxenites and gabbroic rocks may have potential use in the exploration for economic sulfide-poor PGE mineralization. Although the paleomagnetic methods used in this study are probably not of direct use in exploration, they were able to distinguish the different lithologies in the BCF. This substantiates the results of the susceptibility measurements in characterizing PGE mineralized, titaniferous magnetite-bearing rocks. The results of the paleomagnetic study also show that the NRM of the Ghost Range intrusive complex is not primary and therefore the Archean apparent polar wander path as it is currently defined is incorrect.

abstract: Thesis

abstract: Bachelor of Science (BSc)


contributor:
Dickin, A. P.
McNutt, R. H.
Geology

abstract: Title: Pb-Pb Zircon Dating by Direct Evaporation: Method Development and Selected Geological Applications, Author: Edna L. Mueller, Location: Thode

abstract:
The zircon evaporation method requires no chemical
treatment of the zircon grain in the form of acid dissolution
or isotopic spiking. In a test of this method, the derived
Pb-Pb age is consistent with conventional U-Pb age of zircons
from the Battersea Pluton.

Zircons from the Britt Domain reveal a variety of ages
from a complete isotopic resetting to the time of the
Grenville orogeny (approx. 1100 Ma) to ages of plutons at
approx. 1330 Ma and 1450 Ma. An orthoquartzite, CBQ,
contained zircons from a Penokean aged terrain and an Archean
aged terrain. This may be evidence for a collision of a
Penokean aged island arc onto the Superior Province. The age
of the Pine Cove Pluton constrains minimum age of the Penokean
suture. Its minimum age of approx. 1330 Ma constrains the
time of last movement of the French River suture line.

Zircons from the Cedar Lake and Lac Seul gneiss from the
Winnipeg River Belt of the Superior Province show evidence of
the last major metamorphic event, the Kenoran orogeny at 2700
Ma, and its age of crystallization at 3170 Ma. One zircon
from the Cedar Lake tonalite results an age of 3391±2 Ma.
This may be a xenocryst from older crust mixed into the
tonalite.
The zircon evaporation technique is ideal for
reconnaissance work due to the ease of sample preparation and
the large number of zircons that can be tested quickly.

abstract: Thesis

abstract: Master of Science (MS)


title: A Study of Stylolite Development

abstract: Title: A Study of Stylolite Development, Author: Craig M. Rice, Location: Thode

abstract:
A petrographic study of samples from the Lockport
Formation, all having undergone stylolitization has shown
two stages of stylolite development.

Stage One - The development of microstylolites and microstylolite swarms leads to the formation of a
stylolite. Through the process of amalgamation,
microstylolites in a swarm merge together to form
an "adolescent" stylolite. Geometric changes of
the solution seams are analagous to the principle
of superposition of waves.

Stage Two- An "adolescent" stylolite grows into
a "mature" stylolite as the result of discrete
solution of the surface. The geometry of the
stylolite becomes more sutured and interpenetrating
as a result of pressure-solution.

The formation of a stylolite suggests an even greater volume loss than would be anticipated by the amplitude of the
solution surface. Stylolite development is an active
evolutionary process.

abstract: Thesis

abstract: Bachelor of Science (BSc)


contributor:
Hale, C. J.
Geology

abstract: Title: A Paleomagnetic Analysis of the Deformation and Hydrothermal Alteration in the Killarney Igneous Complex, Ontario, Author: Andrew Wiacek, Location: Thode

abstract:
The Killarney Igneous Complex lies along the Grenville
Front, forming a wedge between the Grenville and Southern
Provinces of the Canadian Shield. The complex consists of a
granitic pluton and associated felsic volcanic rocks that
have been subjected to both mid-Proterozoic and Grenvillian
tectonism. This study sought paleomagnetic confirmation of
pre-Grenville deformation by carrying out AF and thermal
demagnetization experiments on 226 samples representing both
the massive and foliated parts of the complex. This was
accompanied by an analysis of polished thin-sections to
attempt to determine a paragenesis for the remanence
carrying minerals.

Sixty-four specimens of foliated and veined, hematiteenriched
porphyry carry a stable southwesterly magnetization
(Declination= 242.4°, Inclination= -26.4°, K = 17.5, A95 =
11.2°) or its antipole. The paleomagnetic pole implied by
this magnetization (Longitude= 19.3°E, Latitude= 29.1°, dp
= 9.6°, dm = 10.9°) is consistent with an age of somewhat
less than 1100 Ma. This magnetization is a CRM that was
acquired during the hydrothermal alteration of the porphyry.
As a consistent magnetization is carried by highly sheared
rocks as well as the hematite-enriched porphyry, it is concluded that the shearing must have occurred prior to the
hydrothermal event. Thus, the onset of Grenville tectonism
in the Killarney region began before 1100 Ma. Sufficient
paleomagnetic evidence was not obtained to determine the
timing of pre-Grenville tectonism.

abstract: Thesis

abstract: Master of Science (MS)


title: Syntheses of Novel Polymer Micro-Spheres with Surface and Interior Grafts

contributor:
Stöver, H. D. H.
Chemistry

subject: syntheses, novel, polymer, micro-spheres, surface, interior, grafts, electron, microscopy

abstract:
 Polymers and block copolymers have been grafted from hard and soft polymer micro-spheres by atom transfer radical polymerization (ATRP) and ring opening polymerization (ROP). The hard and soft micro-spheres were prepared by precipitation polymerization of divinylbenzene-80 (DVB80), and of DVB80/hydroxyethylmethacrylate (HEMA), respectively, in neat acetonitrile.

 Residual vinyl groups in the hard, poly(DVB80) micro-spheres were hydrochlorinated to form benzyl chloride groups that subsequently served as ATRP
initiators for poly(styrene) and poly(styrene-block-4-methylstyrene) grafts. Hydrophilic
poly(HEMA) and poly(2-( dimethylamino)ethyl methacrylate) poly(DMAEMA) were also grafted from hard micro-spheres containing bromopropionates, using ATRP in the presence of CuBr/Me4Cyclam.

 Hydroxy groups in soft, poly(DVB80-co-HEMA) micro-spheres were used directly as initiators for ring opening polymerization of ε-caprolactone catalyzed by
aluminum compounds. In the addition, they were reacted with α-bromopropionyl bromide to form ATRP initiators.

 Several combinations of ATRP-ATRP and ROP-ATRP with different monomers were carried out using these initiator micro-spheres. In particular, the soft micro-spheres grafted with poly(methacrylic acid), poly(methylmethacrylate), poly(methylmethacrylate-block-dimethylaminoethylmethacrylate), poly(methylmethacrylate-block-trimethylammoniumethylmethacrylate), poly(methylmethacrylate-block-HEMA),
poly(methylmethacrylate-block-glycidylmethacrylate), poly(ε-caprolactone-block-
methylmethacrylate), poly(ε-caprolactone-block-dimethylaminoethylmethacrylate).

 The internal morphology of these homo and block copolymer grafted microspheres was studied using electron microscopy and x-ray microspectroscopy.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Electronic Spectra of S2O

contributor:
King, G. W.
Physics

subject: electronic, spectra, absorption, vibrational, bands

abstract: Three electronic absorption systems of the S2O molecule, each having discrete vibrational structure, were observed in the spectral region 2000 - 7400 Ȧ. Long pressure path lengths were used to observe very weak absorption bands. Two of these spectral systems have not been observed previously. Vibrational analyses of the spectral systems were made. The quasilinear character of the ground electronic state of S2O has been established.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: The Development and Evaluation of Multi-Modal Microbubbles and New Strategies for Targeted Ultrasound, Nuclear and Optical Imaging

contributor:
Valliant, John
Chemical Biology

subject:
Multimodal imaging
Molecular ultrasound imaging of cancer
Microbubbles
bioorthogonal chemistry

abstract:
Gas filled microbubbles (MBs) stabilized by a shell (e.g. lipids) are commonly used as ultrasound (US) contrast agents. Attaching biomolecules to the surface of MBs allows for molecular US imaging of various diseases. With the increased interest in targeted US imaging, new platforms to prepare disease-targeted MBs are necessary. Furthermore, attaching signaling agents to MBs creates multi-modal imaging opportunities, enhancing visualization and quantification of disease biomarkers.
	In this thesis, MBs labeled with 99mTc and/or rhodamine dye by taking advantage of the strong interaction between biotin and streptavidin are reported. Radiolabeling of MBs was achieved in good radiochemical yield (~ 30%). 99mTc-labeled MBs were targeted to vascular endothelial growth factor receptor 2 (VEGFR2) using an anti-VEGFR2 antibody and to prostate specific membrane antigen (PSMA) using small-molecule based PSMA inhibitors. In vitro evaluations showed successful binding of MBs to the target while in vivo targeting assessments were unsuccessful.
	New strategies to target MBs to the site of interest were then developed through the use of the bioorthogonal reaction between tetrazine (Tz) and trans-cyclooctene (TCO). A biotinylated derivative of Tz was loaded on streptavidin coated MBs to create a Tz-derivatized MB (MBTz). Targeting MBTz to extracellular markers of cancer such as VEGFR2, PSMA and urokinase plasminogen activator receptor (uPAR) in vitro was achieved using TCO-conjugated antibodies. In vivo targeting was successful for VEGFR2 and PSMA, but not uPAR.
	Translating the new strategy to other US contrast agents was then investigated. Gas vesicles (GVs) produced in halobacteria were conjugated with TCO using amide-coupling chemistry. A 99mTc-labeled derivative of Tz was loaded on TCO-GVs (RCY= 59%) and their distribution assessed by SPECT/CT imaging and ex vivo tissue counting. Having established a convenient platform to conjugate molecules to GVs and MBs, future work focuses on developing a new generation of human compatible molecular US imaging probes.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: OPTIPAC: A User-Oriented Computer System for Optimization in Engineering Design

contributor:
Siddall, J. N.
Mechanical Design

subject: OPTIPAC, user-oriented, computer, system, optimization, design, nonlinear, documentation

abstract:
 A description is given of the multi-technique nonlinear optimization system called OPTIPAC.

 The overall organization of the program is outlined and the significant features of each of the method subroutines are discussed. Considerable emphasis has been placed on the documentation for the system, and the two manuals which have been written are described briefly. The results of three test problems are included to demonstrate the value of having a variety of techniques in the package.

 A preliminary evaluation of OPTIPAC's performance is given, with relevant suggestions for further development.

abstract: Thesis

abstract: Master of Engineering (MEngr)


title: Investigating Substructure Flexibility in Column-Top Isolation Systems with Elastomeric Bearings

contributor:
Becker, Tracy
Civil Engineering

subject: isolation, retrofit, rotation, substructure, flexibility, elastomeric

abstract:
Seismic isolation is a method of earthquake resistant design which has been proven to effectively reduce the damaging effects of earthquakes on buildings as well as the contents within them. However, traditional implementation of an isolation system tends to be expensive. For new construction, rigid diaphragms above and below the isolation layer and construction of a seismic gap contribute to expenses, while retrofit applications also require excavation beneath the building and may need extensive foundation work. To mitigate these major costs bearings may be placed on the tops of columns, forgoing the construction of a seismic gap, additional rigid diaphragm, and foundation work. However, columns under the isolation layer may be flexible, changing the bearing end conditions traditionally assumed.

To investigate the effects of flexible end conditions on elastomeric bearings, an analytical model that accounts for translation and rotation of both endplates was developed based on Haringx's theory. The derivation accounts for compressibility of the rubber and results in a simple stiffness matrix. To evaluate the model, an experimental program testing column-bearing subassemblies under quasi-static cyclic conditions was conducted. Experimental findings show that flexible end conditions can significantly reduce the lateral stiffness of elastomeric bearings. Simulations with the theoretical model compare well under small deformations, but elastic softening of the moment-rotation relationship causes theoretical results to diverge from experimental with larger endplate rotations.

The effectiveness of column-top isolation as a retrofit strategy was investigated through nonlinear time history analyses of a moment resisting frame designed to the 1965 National Building Code of Canada and retrofitted with column-top isolation. The frame was simulated under ground motions representative of current hazards and showed that the retrofit resulted in significant reductions in interstory drifts and floor accelerations. Yielding was observed throughout the original frame under maximum considered earthquakes, while the retrofit frame remained elastic.

abstract: Thesis

abstract: Master of Applied Science (MASc)


contributor:
Hitchcock, Adam P.
Chemistry

abstract: Title: The Inner Shell Electron Energy Loss Spectra of Some Cyclic Organic Molecules, Author: David C. Newbury, Location: Thode

abstract:
Inner shell electron energy loss spectroscopy has been used
to obtain the core excitation spectra of some cyclic molecules.
Recorded under the conditions of small momentum transfer (typically
2.5 keV impact energy and small angle scattering, <5°), the spectra
are equivalent to those produced by soft x-ray photoabsorption. The
molecules investigated are aromatic (benzene, pyridine, furan and
pyrrole), unsaturated (cyclopentene, cyclohexene and
cyclo-octatetraene) and saturated (cyclopentane, cyclohexane,
tetrahydrofuran, pyrrolfdine and piperdine) species. The
heterocyclic species contain a single heteroatom which is either
nitrogen (pyridine, pyrrole, pyrrolidine and piperdine) or oxygen
(furan and tetrahydrofuran). In all cases the spectra are dominated
by shape resonance features. The carbon K-shell and heteroatom
K-shell spectra are quite similar indicating the transitions are to a
similar set of unoccupied orbitals.

In certain cases, condensed phase x-ray 'photoabsorption'
spectra (recorded by partial electron yield) were available for the
purposes of comparision. Such comparisions are very useful in
unambiguously identifing Rydberg, π* and δ* states. As a result the carbon K-shell excitation spectrum of benzene has been reassigned. A
previously unidentified class of (1s -> π*(CH2)) transitions has been
identified and characterized in the spectra of the saturated
molecules.

All of the spectra studied show continuum resonances which
could be assigned to δ*shape resonances. The saturated cyclic
systems show a second continuum resonance which is attributed to the
overlap of in-ring atomic orbitals. This feature is strongest in the
five membered ring systems with a heteroatom. The relationship
between the shape resonance position and bond length is extended to
these molecules. In the cases where there is extensive
delocalization the simple relationship begins to breakdown.

abstract: Thesis

abstract: Master of Science (MS)


title: A Study of Lithium Flouride Etch Morphologies using Silica Gel

contributor:
Ives, M. B.
Chemistry

abstract: Title: A Study of Lithium Flouride Etch Morphologies Using Silica Gel, Author: R. O. McElroy, Location: Mills

abstract:
Cleavage surfaces of lithium fluoride are
etched on a silica hydrogel containing ferric
ions as inhibitor. The gel eliminates
turbulence in the system and retards the
diffusion of ferric ions towards the dissolving
interface. The dissolution etch pits and
features are examined by interference and
electron microscopy. The ledge structure of
pits thus formed is very regular. An
explanation for the observed rounding of pits
at high inhibitor concentration is proposed.

abstract: Thesis

abstract: Master of Science (MS)