title: Late-Quaternary Vegetation History, Lena River, Siberia

contributor:
MacDonald, G. M.
Geography

subject:
late-quaternary vegetation
lower lena river region
siberia

abstract: This thesis is missing page 57, this page is not in any of the other copies. -Digitization Centre

abstract: Scientists believe that the global climate is undergoing significant changes due to anthropogenic increases of carbon dioxide (CO2) and other Greenhouse gases. The relationship between climate and vegetation is not fully understood. Knowledge of the response of vegetation to past climate change aids in the understanding of potential vegetation responses to climatic changes due to the Greenhouse effect. The objectives of this thesis were to determine if vegetation in the lower Lena River Region has changed in the past, what were the factors which caused the changes and over what time scales did the changes occur. To address the objectives, the pollen, stomate and sediment stratigraphy of a core from a medium size lake, located in north-central Siberia, were analysed. Radiocarbon dating indicates that the record spans the last 12310 yr BP, and possibly the last 15000 yr BP. The early part of the fossil record was characterised by short rapid changes in the vegetation. The initial shrub tundra was quickly replaced by herb tundra with sparse vegetation cover. This was followed by a reversion to shrub tundra conditions at ~12000 yr BP. A clear Younger Dryas signal is found in this record between 11000 and 10000 yr BP, characterised by a shift from shrub tundra to herb tundra dominated by taxa with arctic affinities. The warming at the close of the Younger Dryas signalled the first appreciable climatic amelioration at this site. Following 10000 yr BP, Alnus became abundant in the pollen record and likely on the landscape. The dominance of Alnus was short lived however. At ~8500 yr BP arboreal vegetation, dominated by Larix dahurica, became abundant in the pollen and stomate record. The expansion of forests was the result of changes in the orbital parameters of the earth as predicted by Milankovitch cycles. Arboreal vegetation persisted in this region until-3500 yr BP when the modem shrub tundra vegetation was established. The use of a new technique, stomate analysis, proved extremely useful. Stomates accurately recorded the expansion and retreat of treeline across this region. This study clearly indicates the usefulness of this technique, especially for investigating fluctuations of treeline.

abstract: Thesis

abstract: Master of Science (MS)


title: Postactivation Potentiation in Human Ankle Muscles: The Effect of Age and Contraction Type

contributor:
Hicks, Audrey
Kinesiology

subject:
postactivation potentiation
human ankle muscles
effect of age
contraction type

abstract: This thesis is missing page 33 and 98. Neither of which are in the other thesis copies. -Digitization Centre

abstract: Thesis

abstract: Master of Science (MS)


title: Digital Implementation of a Soliton System

contributor:
Wong, Kon
Hranilovic, Steve
Electrical and Computer Engineering

subject:
digitial
soliton system

abstract: This thesis is missing pages xiii, xiv and xv. None of which are in other copies of the thesis. -Digitization Centre

abstract:
Solitons and soliton systems have introduced many interests in the applications of signal processing and communication systems due to their special properties. To facilitate the various applications, a digital soliton system is designed to overcome the inherent drawbacks of traditional analog soliton systems in this thesis. Wave digital theory is employed to design a digital model of the nonlinear Toda lattice circuit. The designed model is implemented in Simulink, and numerical results of the simulation verifies the important properties of the digital model and show it to be a good digital soliton system simulator. Moreover, an example of a soliton communication system is provided to demonstrate the digital soliton system simulator can work as well in soliton communication systems, avoiding the inherent problems of analog implementations.
In addition, the digital Toda lattice circuit modelled in Simulink can be customized to run in DSP and FPGA. Such hardware co-processing will highly improve the speed of the simulation processes.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Power, Bandwidth and Complexity in Maximum Likelihood Sequence Estimation

contributor:
Anderson, J. B.
Electrical Engineering

subject:
power
bandwidth
sequence estimation

abstract: This thesis is missing page 155, the other copies of the thesis are also missing this page. -Digitization Centre

abstract:
This thesis develops a two dimensional Viterbi Algorithm for the maximum likelihood sequence estimation over band limited baseband channels with intersymbol interference. Degradation, decision depth, 99% energy bandwidth and the channel cost are used as the performance measures for the comparisons of different channels. The four measures are extensively evaluated for channels with length up to four signalling intervals. The results of each measure are presented in contour form. Error events analysis shows that the degradation contours are governed by elliptical equations. Maximum degradation results from state path merge at a depth equal to the channel length plus one. By analysing periodic state sequences, we found that catastrophic error propagation contours are mainly governed by linear equations. Generally, channels with longer length have narrower minimum bandwidth but higher degradation.
A channel cost similar to Shannon capacity equation is proposed to jointly minimize both degradation suffered and bandwidth required for signalling over a channel. According to the equation, the channel cost is influenced more by the bandwidth than by the degradation and thus the regions of low channel cost lie on the regions of narrow bandwidth. Also low channel cost regions are found to be on the regions of long decision depth and thus require higher complexity for maximum likelihood sequence estimation. In addition, it is found that minimum channel cost decreases with increasing channel length.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Metasomatism in the Kamiskotia Mafic Complex

subject:
metasomatism
kamiskotia mafic complex

abstract: This thesis is missing page 16, no other copies of this thesis have the page. -Digitization Centre

abstract:
Metasomatism was taken by Goldschmidt (1922) as being metamorphism involving introduction and removal of certain substances, with a corresponding change in the chemistry and
mineralogy of the rock concerned. Using this definition, there is strong evidence of metasomatism having played an important role in the transformation of part of the Kamiskotia mafic intrusion from a norite to a greenschist facies rock. The importance of metasomatism has generally proved difficult to evaluate because of disagreement on a quantitative approach to the problem. Two of the approaches suggested in the literature have been employed to characterize the chemical changes accompanying metamorphism of the Kamiskotia complex; one assuming constant volume, the other assuming constant alumina. The latter approach, supported by most recent work in this area (Carmichael, 1970; Korzhinsky, 1964) is favoured. It defines a mobility series that agrees quite well with Korzhinsky's for all elements except iron. It is concluded
that metamorphism, of the Kamiskotia norite has been accompanied by significant removal of potash, soda, iron and silica besides the addition of water and carbon dioxide. Reactions, constructed on the basis of mineral relationships observed in thin section combined with the calculated chemical changes are proposed. The source of the metasomatic fluids and the site of deposition of removed material is speculated upon.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Isotopic Studies of Plutonic and Metamorphic Rocks from the Frontenac Arch, Grenville Province of Ontario and from Islay, in the Southern Inner Hebrides of Scotland

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

subject:
isotopic study
plutonic rock
metamorphic rock
fronetnac arch
Canada
Scotland

abstract: This thesis is missing either page 57 or 58. The other copies of this thesis do not have this page either. -Digitization Centre

abstract: This study is an investigation of two regions which were once part of the same Proterozoic margin: the Frontenac Axis in the Southeastern Grenville Province of Ontario, and the island of Islay in Scotland. Shieh (1985) performed an oxygen isotopic study on the granitic plutons and surrounding metasediments in the Frontenac terrane. For the granites south of the Rideau Lake Fault, he observed extremely high 18O/16O ratios of +14.0%o (relative to SHOW), whereas north of the fault, the plutons gave ratios of around  10%o. Five of the plutons in Shieh's study have been dated using U-Pb zircon geochronology, with the following results: Battersea -1165 ± 3 Ma, Lyndhurst -1166 ± 3 Ma, Perth Road -1166 ± 3 Ma, Crow Lake -1176 ± 2 Ma, and Westport -1076 ± 2 Ma. The zircon ages are younger than the depleted mantle Nd model ages obtained (1211 to 1480 Ma) and signify that the plutons may be derived from a mantle source with contamination by the older surrounding metasediments which have an average Nd model age of 1790 Ma. Correlation between initial Nd (ENd(t) from +1 to +3) and initial Sr (Esr(t) from +9 to +21) also shows a mixed origin for the plutons. However, oxygen isotopes show that contamination by marble may also have occurred. Two features distinguish the Frontenac terrane southeast of the Rideau Lake Fault (RLF) from the Central Metasedimentary Belt (CMB) to the northwest: 1) the anorogenic (i.e. within plate) chemical signatures of the plutons, which are similar to the Hid-Proterozoic anorogenic granites that occur throughout North America (Anderson, 1983); and 2) the unique zircon ages for the plutons south of the RLF (1166 to 1176 Ha) that occur nowhere else in the CMB. This implies that the two areas define different crustal terranes. However, since Penokean (ca. 1800 Ha) crustal extraction ages are found in both terranes they may represent displaced segments of a single Penokean continental margin. In Scotland, a gneiss terrane on Islay was always inferred to be part of the Archean Lewisian complex. However, isotopic evidence shows that the Islay terrane is early Proterozoic in age (1782 Ha by U-Pb zircon geochronology) and that it is juvenile mantle-derived material, not a reworking of Archean crust during the Proterozoic. As a result, two major implications for the crustal evolution of Northern Britain are: 1) the Grampian terrane, an area directly adjacent to the newly defined Proterozoic Islay block, is probably underlain by Proterozoic basement; and 2) Northern Britain can be included in the Lower Proterozoic reconstruction of the Laurentian Shield. The similar crustal extraction ages observed in the Grenville of Ontario and on Islay give proof that these areas were part of a major 1.8 to 1.9 Ga crustal formation event, stretching from the southwestern U.S. to Finland.

abstract: Thesis

abstract: Master of Science (MS)


title: The Chemistry of the Dietl Complex, [Cl(MeC2Me)3PdCl]2

title: The Chemistry of the Dietl Complex

contributor:
Maitlis, P. M.
Chemistry

subject:
chemistry
dietl complex

abstract: This thesis is missing page 78, the other copies of this thesis do not have the page either. -Digitization Centre

abstract: In benzene solution at 10°, 2-butyne and bis(benzonitrile)palladium chloride reacted together to give the Dietl complex [(Me2c2)3PdC12]2. Reaction of this complex with Ph3E (E = P, As, Sb) gave hexamethyl-benzene, 1-vinyl-1,2,3,4,5-pentamethylcyclopentadiene, and 1-(1-chlorovinyl)-1,2,3,4,5-pentamethylcyclopentadiene. The complex was decomposed by hydrazine to the vinylpentamethylcyclopentadiene; with halogen hexamethylbenzene was formed; while lithium aluminum hydride gave largely 1-ethyl-1,2,3,4,5-pentamethylcyclopentadiene. In the presence of o-phenanthroline a new complex was formed, identified as 1-(chloro-(o-phenanthroline)palladium)-vinyl-1,2,3,4,5-pentamethylcyclopentadiene. Similar complexes were obtained with bipyridyl and pyridine. A structure for the Dietl complex is proposed and the mechanisms of some of its reactions are discussed.

abstract: Thesis

abstract: Master of Science (MS)


title: Intra-Arterial Pressure during Arm Exercise

subject:
intra-arterial pressure
arm exercise
exercise
pressure

abstract: This thesis is missing page 222, the other copies of this thesis are missing the page as well. -Digitization Centre

abstract: Thesis

abstract: Master of Science (MS)


title: Development of Computer Software Package for 3-D Plotting and Some Applications

contributor:
de Malherbe, M. C.
Design

subject:
computer software
3-D plotting
development
application

abstract: This thesis is missing pages 68, 118, 129 and 189 and these pages are not in any other copies of the thesis. -Digitization Centre

abstract: This thesis is a design of a three-dimensional plotting routine for the computer facilities at McMaster University with a subroutine to adopt the package for use on other computer systems and is divided into four sections. Section A is a review of the necessity of computerized plotting in science and engineering design with particular emphasis on software sophistication, which is the subject of this work. Section B describes the principles employed and the basic logic of the software package. The method by which a three-dimensional solid is mapped is also explained. Section C is a complete user's guide to the package. Section D deals with some applications for the package such as the solution of design optimization problems, visual analysis of data sets, an aid to teaching and combined interpolation and display of experimental results.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Design and Implementation of a Micro-Computer Controlled Cutting Table

title: Micro-Computer Controlled Cutting Table

contributor:
Campbell, C. K.
Engineering Physics

subject:
design
implementation
micro-computer
cutting table

abstract: This thesis is missing page vi, the page is not present in the other copies of this thesis. -Digitization Centre

abstract: This thesis deals with the design and implementation of a micro-computer controlled cutting table used to prepare large scale patterns for Surface Acoustic Wave (SAW) devices. This automated cutting table simplifies the creation of many SAW patterns and makes previously unattainable patterns possible. The design is extremely versatile and can cut as well as straight lines in any direction in two dimensions. A commercially available, 44 inch square, cutting table was automated by mounting stepping motors on each of the two axis. The motion of the motors is controlled by an SDK-85 micro-computer and several peripherals. A full description of the hardware, software and a successful experimental test is included.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Replication and Transcription Activation by Polyomavirus Enhancer Motifs PEA1, PEA2, and PEA3

contributor:
Hassell, John
Biology

subject: replication

subject: transcription activation

subject: polyomavirus

subject: polyomavirus enhancer motif

subject: PEA1

subject: PEA2

subject: PEA3

abstract: This thesis is missing page 157, the other copies of the thesis did not have the page either. -Digitization Centr

abstract: The polyomavirus enhancer is organized into three elements. One of these elements, Element 2, is particularly interesting because the activities of the factors which interact with it are highly regulated. There are at least three cellular proteins, PEA1, PEA2, and PEA3, which bind to adjacent sites in Element 2. These proteins are differentially active in mouse cells at different developmental stages and their activity is modulated by serum, tumor promoting agents and the products of several oncogenes. It is likely, therefore, that these cellular proteins play an important role in interpreting growth stimuli and other physiological cues in the mouse. A plasmid was contructed which can be used to test enhancer elements for their ability to activate both transcription and DNA replication. This plasmid includes the Py origin of replication and a minimal promoter, consisting of a TATA box only, controlling expression of a reporter gene. The activity of the PEA factors was studied by cloning the binding sites for these factors into this reporter plasmid as monomers, multiple tandem copies, and in paired combinations, and testing their ability to activate transcription and DNA replication in vivo. The results of these studies show that PEA1 and PEA3 can function independently and cooperatively to activate both replication and transcription. By contrast, PEA2 is unable to independently activate transcription and represses PEA1-activated transcription when the binding sites for these factors are located adjacent to one another. However, PEA2 functions cooperatively with PEA1 to activate DNA replication, and can weakly activate replication on its own.

abstract: Thesis

abstract: Master of Science (MS)


title: Changing Depositional Environments in the Marginal Zone of a High Latitude Ice Sheet

contributor:
McCann, S. B.
Geography

subject:
depositional enviornments
high latitude ice sheet
ice sheet

abstract: This thesis is missing page 28 from this and all other copies. -Digitization Centre

abstract:
Glacial and glacially-influenced deposits examined at two sites in west-central Ellesmere Island provide insights into the nature of glaciation during the late-Wisconsinan and Holocene advances, and the modes of deposition from arid, high latitude ice bodies. Glacial lithofacies identified indicate that englacial debris content varied spatially and it is inferred that basal thermal conditions also exhibited a complex pattern. Direct glacial deposits usually consist of unsorted diamicts with a complete size range of matrix components, indicating an absence of meltwater-sorting or winnowing during deposition. Glacially-influenced fluvial, lacustrine, and nearshore marine deposits show that most of the Quaternary sediments were deposited by low-frequency, high magnitude events during deglaciation. A tentative reconstruction of late-glacial history in the Strathcona Fiord area proposes that an ice tongue surged down Strathcona Fiord from a previous maximum position coincident with the present day head of the fiord. This surge destabilised the margin locally, causing rapid collapse in the valleys and melting into ice-cored basins on the higher plateau areas. Periodically these ice-cored basins would drain, providing large water and sediment discharges and reworking in some sites whilst leaving other deposits unaffected. Subsequent reworking has been minimal in the cold, arid environment where continued uplift favours fluvial incision rather than extensive sandur development.
Examination of the modern ice margin shows that the ice here is frozen to the substrate but basal debris bands indicate that at some localities basal temperatures must be above pressure melting point. Patterns of debris entrainment and deposition and debris lithologies suggest that much of the transported debris is incorporated where lobes of ice begin to flow out from the main ice cap.

abstract: Thesis

abstract: Master of Science (MS)


title: Three Essays on the Economics of Child Well-Being

contributor:
Veall, Michael
Economics

subject:
Child well-being
Health economics

abstract:
This thesis consists of three major essays that respectively investigate three factors that
might influence child well-being: family income, family structure, and time spent in child
care. Using the Canadian National Longitudinal Survey of Children and Youth (NLSCY),
the first essay finds that income-based gaps in child health are statistically significant,
quantitatively meaningful, and more pronounced as children age. Contrary to previous U.S.
evidence, the observed income gradient in child health cannot be attributed to the protective
effects of income on the incidence and severity of children’s health problems at birth and
chronic conditions. This contrast may reflect the effects of universal health insurance in
Canada. An instrumental variable estimator predicts a stronger causal effect of income on
child health than does OLS. Also using the NLSCY, the second essay indicates that children
persistently living in single-parent families have poorer health and educational outcomes
compared to children persistently living in intact families. In addition, children whose
parents separate during a given period exhibit worse health and educational outcomes
compared to children whose parents remain together. Using a sibling fixed-effect approach
substantially reduces the associations between children’s outcomes and parental separation
predicted by OLS, but several gaps, especially in mental health, remain statistically
significant and quantitatively meaningful. Using time-use data taken from the General
Social Survey (GSS), the third essay finds that parental time spent in child care
continuously and dramatically increased in Canada between 1986 and 2010. The increase
in average time spent in child care applied to all gender and education groups but was
associated with a growing dispersion in child care time. While more highly educated
parents are more likely to spend time in child care, the education-based gaps in child care
time are found to decline.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Intracellular pH Regulation, Acid-Base Balance , and Metabolism after Exhaustive Exercise in Rainbow Trout (Salmo gairdneri) and Starry Flounder (Platichthys stellatus)

contributor:
Wood, C. M.
Biology

subject:
intracellular pH regulation
acid-base balance
metabolism
exhaustive exercise
rainbow trout
starry flounder

abstract: This thesis is missing pages 87, 172 and 255. No other copies of the thesis have these pages. -Digitization Centre

abstract: This thesis examined the effects of exhaustive exercise on acid-base and metabolite status in the intracellular and extracellular compartments of two very different fish species: the active, pelagic rainbow trout, and the sluggish, benthic starry flounder. In both species, exhaustive exercise resulted in an acidosis in the extracellular compartment of mixed respiratory and metabolic origin. Despite the reduction in pHe, red blood cell pHi was well regulated, though more precisely in trout than in flounder. Catecholamines were mobilized into the blood after exercise in trout but not in flounder. Circulating catecholamines may play an important role in regulating red blood cell (RBC) pHi in trout after exercise. In trout, lactate appeared in the blood in excess of H+ ; the reverse pattern was observed in flounder. H+ appearance was similar in both species. Differential release of lactate from the muscle mass was apparently responsible for this discrepancy. After exhaustive exercise, both trout and flounder experienced a severe intracellular acidosis in the white muscle, as measured by 14c-DMO (5,5-dimethyl -2,4-oxazolidinenione) distribution. H+ and lactate were not produced in equimolar quantities, with H+ produced in excess of lactate. Muscle lactate and H+ production was about 3-fold lower in flounder than in trout. The muscle intracellular acid-base disturbance was corrected more rapidly in flounder (4-8h) than in trout (8-12h). In flounder, this occurred prior to , but in trout after , correction of the extracellular acidosis. In flounder, a more rapid correction of muscle metabolite status was associated with the more rapid correction of the intracellular acidosis. After exercise there was a reduction in the whole body extracellular fluid volume and expansion of the intracellular fluid volume, largely reflecting changes within the muscle. This fluid shift resulted in a general hemoconcentration. Exercise led to a transient increase in net H+ excretion in both trout and flounder. Negligible amounts of lactate were transferred to the water. In flounder, about 20% of the total H+ load produced passed through the extracellular space and was transiently stored in the water, which appeared to hasten correction of the intracellular acid-base disturbance. In contrast, in trout, a much smaller portion of the acid load (about 6%), though about the same absolute amount as in flounder, was transferred to the water. This appeared to expedite correction of the extracellular acidosis.The results of this thesis argue against a prominent role for the Cori cycle in the final disposition of the lactate burden produced during exercise. Instead, it is suggested that the bulk of the lactate was metabolized in situ, either by oxidation or glyconeogenesis. In flounder, this was almost the sole fate of lactate, as very little appeared in the blood space. In trout, a significant portion of the lactate was exported to the blood, which was taken up and metabolized by aerobic tissues.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: In Vitro and In Vivo Analysis of Protein-Protein Interactions Involved in the Formation of Epithelial Adherens Junctions

title: Protein-Protein Interactions in Forming Adherens Junctions

contributor:
Baron, Christian
Biology

subject:
epithelial adherens junctions
epithelial
protein-protein interactions
adherens junctions

abstract: Adherens junctions are a main cell-cell adhesion structure found in epithelial cells. The stability of adherens junctions is attributed to various protein-signaling cascades and importantly the interaction between the transmembrane protein E-cadherin and cytoplasmic p120 catenin. This interaction is critical for cell adhesion and prevention of uncontrolled growth in normal cells. The interaction interface between these two binding partners was previously determined to comprise p120's Armadillo repeat domain (p120Arm) and Ecadherin's cytoplasmic juxtamembrane domain (Ecadc). Based on this information, peptide aptamers were derived from p120Arm and their interaction with Ecadc was tested in vitro. We reasoned that those could be expressed in vivo to stabilize adherens junctions at the cell-cell junction. In this study, we established protein-protein interaction assays to demonstrate p120Arm's ability to bind Ecadc and then used these assays to determine if p120Arm-derived peptides may competitively bind Ecadc. We demonstrated the interaction between p120Arm and Ecadc using assays that were not previously used such as: co-precipitation, analytical gel filtration and the bacterial-2-hybrid assay. However, the p120Arm-derived peptides did not bind to Ecadc or compete its interaction with p120Arm. This may be due to the nature of the assays that may not reflect competitive binding or the aptamers may not adopt the native conformation preventing binding to Ecadc.

abstract: Thesis

abstract: Master of Science (MSc)


title: Analysis of Nickel Contaminants in Several Groups of Case-Control Sets Generated Within the Falconbridge Mining Cohort

contributor:
Shannon, Harry
Statistics

subject:
nickel
nickel contaminants
Falconbridge mining cohort
Falconbridge
Falconbridge mining

abstract:
The Falconbridge study was a historical prospective mortality study conducted at a nickel company in Sudbury Ontario. The study included all the men that worked there for at least 6 months between 1950 and 1976 with an update in 1984. Nearly 11500 subjects were included in the cohort. From here all the subjects identified with lung cancer were selected and matched with different number of healthy subjects (1:1, 1:2, 1:4, 1:6, 1:8, 1:10). Information was generated of the time-intensity of different contaminants normally found in the mining atmosphere and eight of such contaminants were evaluated for the different sets of case:control. Given the fact that some contaminants present a time delay effect, an assessment of this factor was also made using the subject initial and final time of exposure to each contaminant.
Finally a variable selection was performed for the three data sets generated in the project.
The results showed that some of the postulated contaminants did have an effect in the final outcome, however, because of the complex effect between the different chemical compounds a definite conclusion is not given.

abstract: Thesis

abstract: Master of Science (MSc)


title: Testing the Relationship Between Respiratory Diseases and Viral Infections in Various Age Groups

contributor:
Childs, Aaron
Statistics

subject:
respiratory diseases
viral infections
viral

abstract: The objective of this project was to investigate and determine the association between hospitalizations of respiratory diseases with one another and with isolations of viral infections in five age groups. Weekly data on all hospitalizations in Ontario, Canada, from week 14 of 2001 to week 13 of 2003 were obtained for 5 age groups (under 2 years, 2 to 4 years, 5 to 15 years, 16 to 49 years and over 50 years inclusive) for respiratory diseases including, asthma, respiratory tract infection (RTI) and chronic obstructive pulmonary disease (COPD)1. Furthermore, data for viral infections including influenza virus type A and type B (Flu AB) and respiratory syncytial virus (RSV) isolations were also obtained from Health Canada for the same weekly time periods. In order to test for independence and determine a relationship, if any, between hospitalizations of respiratory diseases with one another and with isolations of viral infections, structural time series models were developed for all age groups of the respiratory diseases and explanatory variables were modeled accordingly against the hospital admission counts for the respiratory diseases. These explanatory variables include, other respiratory diseases, viral infections, and lagged values of the dependent variable. Neither FLU AB nor RSV showed a significant relationship with asthma patients of all ages. Weekly RSV peaks coincided with RTI patients under 2 years and RTI peaks in patients 5 to 15 years preceded FLU AB peaks. A relationship between all three respiratory diseases, asthma RTI and COPD, was discovered for all age groups. Peaks of asthma coincided with various transformations of RTI peaks for the five age groups and peaks of COPD coincided with both the untransformed asthma and RTI peaks in patients over 50. For all other relationships, the null hypothesis of independence was accepted. These findings suggest that there is a strong association between respiratory diseases and that children and adults with respiratory diseases respond differently to viral infections. 1 Only data for patients over 50 years was obtained for COPD.

abstract: Thesis

abstract: Master of Science (MSc)


title: Bone Mineral Density Determination Using Digital Radiography

contributor:
Webber, Colin
Health and Radiation Physics

subject:
bone
bone mineral
bone mineral density
digital radiography
radiography

abstract:
There is a need for an improved bone mineral density measurement procedure for neonates. Currently, measurements are made using single photon absorptiometry (SPA). The poor reproducibility of this method means that it has little direct clinical diagnostic application and is therefore not suitable for diagnosing disease in individual patients.
A technique using digital radiography has been developed to measure bone mineral density. Digital images of phantoms and chicken bones were acquired at two kvp settings of a digital angiographic unit. Digital information from water, aluminum and lucite phantoms were used to calculate effective mass attenuation coefficients of the phantom materials. These values were subsequently used in bone mineral density calculations of sections of the chicken bones. The bone mineral densities of the chicken bones obtained from the digital radiography method were compared to SPA measurements. The digital radiography method gave consistently higher bone mineral densities for the bones than SPA. This could be due to the differences in measurement technique as SPA scans a single slice whereas digital radiography images a large area of the bone.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Development and Testing of an Isotropic Light Source or Detector and its Application to Photochemotherapy

contributor:
Wilson, B
Health and Radiation Physics

subject:
istropic light source
isotropic light detector
istropic
Photochemotherapy
isotropic source
isotropic detector

abstract: The production of an isotropic source or detector by fixing a small resin sphere onto one end of an optical fibre is discussed. The potential application of these fibres to Photochemotherapy is reviewed. Isotropic fibres are used as both sources and detectors in experiments designed to measure the amount of light loss in a 1% solution of Neutralipid (an intravenous nutrient supply). Determination of light loss in this solution is important in one application of Photochemotherapy where an estimate of the irradiation time is required.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Absorption and Electrolysis of Hydrogen Sulphide in a Recirculated Alkaline Liquor Containing the Vanadium (IV/V) Redox Couple

subject:
absorption
electrolysis
hydrogen sulphide
recirculated alkaline liquor
vanadium

abstract: This thesis is missing page 89, no other copy of the thesis has this page. -Digitization Centre

abstract: The vanadium mediated electrolysis of hydrogen sulphide has been demonstrated in a bench top pilot plant. The first step in the process is the absorption of hydrogen sulphide from a sour gas stream into an carbonate buffered liquor, pH 9. In the presence of citrate ion, the vanadium (V) in the liquor is reduced to vanadium (IV) by (hydro) sulphide ion, which is oxidized to yellow elemental sulphur. The vanadium (IV) rich solution is then pumped to an electrolysis cell where the vanadium (IV) is reoxidized to vanadium (V) and protons are reduced to elemental hydrogen. The reoxidized liquor is then returned to the absorber. The oxidation of vanadium (IV) to vanadium (V) in the liquor was found to be electrochemically irreversible. The current efficiency for vanadium (IV) oxidation exceeded 90 percent. The voltametric half-wave potential at platinum, was 0.34 v (vs Ag/AgCl, sat. KC1). With the slippage of sulphide or polysulphide ion into the electrolysis cells, the electrodes became passivated with electrodeposited sulphur. This resulted in an increased anode potential demand which may promote the electrosynthesis of oxygen and sulphate ion. The oxidation of vanadium (IV) at the anode releases 4 protons and acidifies the solution adjacent the electrode surface. This may induce carbon dioxide evolution and inhibit the discharge of vanadium (IV). The inhibition appears as a suppressed current and an anodic shift in the voltametric half-wave potential. This inhibition can be minimized at high pH levels in the liquor, buffer capacity., and citrate concentration. The irreversibility of the vanadium (IV/V) couple allows electrolysis cells to be constructed without a cell membrane. This is a significant advantage which will offset the cost of large electrolysis cells. Large cells will enable high energy efficiencies to hydrogen production to be realized. Energy efficiencies greater than 0.28 m3 /kwhr may be indicated. This study features a critical review of sulphide electro-oxidation, a factorial designed voltametric experiment, and a newly identified catalytic response in the polarographic analysis of sulphide ion.

abstract: Thesis

abstract: Master of Science (MS)


title: An Examination of Cytosine Deaminase plus 5-Fluorocytosine Suicide Gene Therapy In Combination With Cisplatin Chemotherapy For the Treatment Of Cancer

title: Suicide Gene Therapy of Cancer

contributor:
Rainbow, A
Gauldie, J
Biology

subject: cytosine deaminase

subject: 5-fluorocytosine

subject: suicide gene therapy

subject: cisplatin chemotherapy

subject: cisplatin

subject: cancer

subject: cancer treatment

subject: treatment of cancer

subject: CDA

subject: 5FC

subject: chemotherapy

subject: cytosine deaminase plus 5-fluorocytosine suicide gene therapy

abstract:
Cancer is a disease characterized by complexity and unpredictability. Consequently, its treatment is difficult and all too often unsuccessful. Almost all cancers are treated with some combination of the traditional anti-cancer armamentarium: surgery, chemotherapy, and radiotherapy. Recently, however, gene therapy has emerged as a promising addition to this existing repertoire. Its application as a single agent, or in combination with other anti-cancer treatments is proving successful in both pre-clinical and clinical settings. In this work I have investigated the combination of a conventional chemotherapy drug, cisplatin, with a type of cancer gene therapy known as cytosine deaminase + 5-fluorocytosine suicide gene therapy. Suicide gene therapy is the intracellular conversion of non-toxic prodrug to its active form by a metabolic enzyme of non-mammalian origin. There are many established enzyme/prodrug combinations, but here the bacterial enzyme cytosine dearninase (CDA) was used to convert inert 5-fluorocytosine (5FC) to highly toxic 5-fluorouracil (5FU). Of the various vector systems for therapeutic gene delivery, adenoviral (Ad) vectors have proven particularly suitable for application to cancer. This work used a first generation adenovirus type 5 vector expressing the enzyme cytosine deaminase (AdCDA) cloned from E. coli. The combination of AdCDA/5FC with cisplatin was chosen because the combination of 5FU and cisplatin, both of which are used extensively in cancer treatment, has proven effective clinically and demonstrates synergy in vitro. This combination was evaluated in murine mammary carcinoma MTIA2 cells, human colorectal carcinoma HT29 cells, HT29pl4 cells, the photofrin resistant sub-line of HT29 cells, and murine melanoma Bl6/FIO cells. The classical clonogenic assay was used to evaluate this combination treatment since it provides an accurate indication of the effectiveness a cancer treatment will have in vivo. AdCDA infected MTIA2, HT29, and HT29pl4 cell lines exhibited a dose response to increasing concentrations of SFC that was significantly different from control vector infected cells. Similarly, uninfected cells demonstrated a dose response to increasing concentrations of cisplatin. The effect of the combination on clonogenic survival, administered in the sequence of a 48 h exposure to SFC followed by 1 h exposure to cisplatin, was greater than additive compared to the effect of the two treatments alone.
F10 cells exhibited a dose response to increasing concentrations of cisplatin. However, it could not be shown reproducibly that AdCDA infected FlO cells exhibited a dose response to SFC that differed significantly from control vector infected cells. Work with the FlO cells was inconclusive regarding the combination treatment, but it rendered information regarding the sensitivity of these cells to what is hypothesized to be an unidentified component present in some preparations of 5FC.
Evaluation of this treatment in vivo, using both murine and human tumor cell lines, will further define the potential of AdCDA/5FC + cisplatin as a clinically relevant cancer treatment.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Effect of Cycloheximide, Cycloheximide Analogues and Azaserine on Asparagine Synthesis in Corn Root-Tips

title: Asparagine Synthesis in Zea mays

contributor:
Oaks, Ann
Biology

subject:
cycloheximide
cycloheximide analogues
azaserine
asparagine synthesis
corn

abstract: This thesis is missing page 57, no other copy of the thesis contains this page. -Digitization Centre

abstract: The experiments in this thesis were undertaken to: 1) compare the effects of cycloheximide and azaserine on asparagine synthesis in root-tip sections of corn; 2) study the effect of protein synthesis on asparagine synthesis in root-tip sections by the use of analogues of cycloheximide; and 3) study the properties of asparagine synthetase extracted from corn roots.When [2-1 4c]-acetate is fed to excised root-tip sections of corn pre-incubated in the presence of cycloheximide, protein synthesis is inhibited. The effect is almost immediate. Within the amide fraction, the levels of glutamine formed in these sections rises over the 3 hour pre-incubation period. Asparagine synthesis gradually declines over the same period. In similar experiments performed with azaserine in the pre-incubation media, protein synthesis was not markedly inhibited. Glutamine levels were immediately increased over the 3 hour period. The effect on asparagine synthesis was also rapid. In contrast to the situation with cycloheximide, the effect of azaserine on amide synthesis is constant over a 3 hour period. Two analogues of cycloheximide - cycloheximide acetate and streptovitacin A - were found to produce effects similar to that of cycloheximide. These analogues were found to inhibit both protein synthesis and asparagine synthesis after a 3 hour exposure period. Six other analogues did not show marked inhibitory effects on either protein synthesis or asparagine synthesis. Asparaqine synthetase activity was found in extracts from corn seedling tissues.. However, assays for asparagine synthetase revealed that the activity was low and 'that other aspartate utilizing enzymes were probably active in the extracts. From the results of this investigation and those of earlier published results a model has been proposed in order to explain the regulation of asparagine synthesis in corn roots.

abstract: Thesis

abstract: Master of Science (MS)


title: A New Computer Programming Language for the Parallel Processing Environments

title: A New Computer Programming Language

subject:
computer programming language
computer program
parallel processing

abstract: This thesis is missing page 95, copies of this thesis do not have the page. -Digitization Centre

abstract: A new high-level, high-order computer programming language designed to complement multi-processor, parallel computing systems is presented, These systems permit a high-order of operation by performing many instructions simultaneously, thus producing significant increases in computing The proposed language is so constructed as to give the user a free and natural format, to express problems which exhibit natural or inherent parallelism® In order to demonstrate some of the main features, a small subset of the language has been written, and implemented as a sequential simulation. In order to relate the language to hardware schemes, a parallel processing array computer is briefly examined. A core language to communicate with parallel computing systems may be constructed from the concepts developed.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Biomechanics of Tibia Tray Augmentation in Total Knee Arthroplasty

contributor:
Ziada, Samir
Hashemi, Ata
Mechanical Engineering

subject:
biomechanics
tibia tray
total knee arthroplasty

abstract: This thesis is missing pages 98-107, all of which are not in the other copies of the thesis. -Digitization Centre

abstract: In total knee arthroplasty with bone defect of the tibia, it was believed that with older designs of tibial tray, both block and stem augments must be used with the tibial tray to improve the knee stability. Obviously, the extended stem causes more difficulties to the surgery as well as more suffering to the patients. Getting rid of the extended stem and still maintaining enough stability is therefore very desirable. The newest tray design, Deltafit Keel tray, which provides much more contact with the human bone structure, may provide enough stability without the extra long stem. The objective in this project is to answer the questions - Is the stem augmentation definitely required alongside the block implant for the cases of bone defect in TKA (Total Knee Arthroplasty) when using the Deltafit Keel tibial tray design? In other words, does the configuration of Deltafit Keel tray with a block provide enough stability in the cases of bone defect? In order to give a reliable answer, three configurations have been studied by conducting both experiments and FEA simulation. The three cases are Deltafit Keel tibial tray only (case 1-no bone defect defect), tray with block augment (case 2-with bone defect assumed) and tray with block and extended stem (case 3-with bone defect assumed). In this study, three commercially available composite bones with isotropic material properties are utilized. For each configuration, the bones are clamped in a testing apparatus and 3000 N static compressive load is imposed on the top surface of the tibia tray at central, medial and lateral locations. In experiment, the strains and displacements at strategically selected locations were measured by strain rosettes (strain gages) and DVRT (Differential Variable Reluctance Transducer) displacement transducers, respectively. In order to simulate the three cases, FE model is established by employing several advanced software including CATIA, True Grid Mesh generator and Abaqus. In order to compare with the experimental results, nine cases (three implant configurations with three different loading positions for each) have been simulated using Abaqus/Standard 6.4. In addition to the nine-case studies, the influence of load offsetting is also investigated by shifting the nodal load along medial-lateral and anterior-posterior directions. It is found that load shifting one node in either direction does not cause significant change in either strain or displacement. Furthermore, FE results of adjacent elements are checked as well and no sudden changes are observed. Since the discrepancy of the output from adjacent elements is negligible, an average value of the elements can be used to represent the output in a small region to compare the experimental strain measured by strain rosettes. Both the experimental data and FEA simulation results lead to the conclusion that comparable stability can be achieved with the configuration of Deltafit Keel tibial tray and a block as compared to the case of Deltafit Keel tray only without bone defect. Moderate improvement of stability, but with significant stress shielding, is found when the extended stem is implanted. For the amount of bone defect and the bone material properties used in this study, the Deltafit Keel tray with a block is the best choice because it is able to provide adequate stability and avoid excessive stress shielding. The loss of a substantial amount of bone to implant an extended stem to trade for the excessive stability may not be worthwhile. Besides, stress shielding is a potential problem which may exist if the extended stem is used.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Identification of RpoS Regulated Genes and their Functions in Escherichia Coli

contributor:
Schellhorn, H. E.
Biology

subject:
RpoS genes
escherichia coli
e coli

abstract: This thesis is missing page 129. Other copies of this thesis do not have the page either. -Digitization Centre

abstract: E. coli expresses an alternative sigma factor, RpoS, in response to starvation and environmental stresses. RpoS is a global regulator and it controls numerous genes, which aids in counteracting these stresses. The RpoS regulon is large but is not completely characterized. We have previously identified over one hundred RpoS-dependent fusions in a genetic screen based on the differential expression of an operon-lacZ fusion bank in rpoS mutant and wild type backgrounds. Forty-eight independent gene fusions were identified including several in well-characterized RpoS-regulated genes such as osmY, katE and otsA. Many of the fusions mapped to genes of unknown function or to genes that were not previously known to be under RpoS control. Based on the homology to other known bacterial genes, some of the RpoS regulated genes with unknown functions may be important for nutrient scavenging. To gain a better insight into the functions of these poorly characterized genes, we tested the ability of the fusion mutants to utilize various carbon sources and to utilize individual amino acids as carbon and nitrogen sources. The results indicate that most of the strains in rpos-backgrounds exhibited better growth in succinate and fumarate and in several amino acids than did the corresponding strains in wild-type backgrounds.

abstract: Thesis

abstract: Master of Science (MS)


title: The Inception of Canadian Health Insurance and its Effects on the Mortality Rate

title: Canadian Health Insurance

contributor:
Veall, M. R.
Statistics

subject:
inception
canadian health insurance
mortality rate
health insurance

abstract: This thesis is missing page 168. The other copies do not have this page. -Digitization Centre

abstract: The Canadian Health Insurance program has been in place for quite some time now and it has always been said that Canadians have some of the best healthcare in the world. Canadian healthcare is very well known throughout the world because every Canadian citizen has the right to healthcare without having to pay for it. The benefits of this program are quite well known but some benefits one might think would result, just might not be there. This paper looks at whether the inception of Canadian Health Insurance has had an effect on the mortality rates of Canadians. Through a statistical analysis, this paper shows that there is no evidence that the Canadian Health Insurance program has had an effect on Canadian aggregate mortality rates. This paper shows that Canadian mortality rates follow a trend to that of the United States. To say Canadians have a similar trend in mortality rate to the United States is perhaps surprising since Canadians are supposed to have a far superior healthcare system.

abstract: Thesis

abstract: Master of Science (MS)


title: A Qualitative Description of Stakeholder Perceptions of Factors Influencing Implementation of School-Based Vision Screening in Ontario

contributor:
Valaitis, Ruta
Nursing

subject:
vision
screening
school
implementation
public health
nurse

abstract: In Canada, nearly 25% of school-aged children have vision problems. Common childhood vision disorders include amblyopia, refractive errors, and strabismus.  Early identification and treatment of these disorders can prevent long-term vision loss and improve academic achievement.  In 2018, the Ontario Ministry of Health and Long-Term Care legislated universal childhood vision screening of all senior kindergarten students.  Although studies have explored the effectiveness of these interventions, few have explored the barriers and facilitators to program implementation.  This study used a qualitative descriptive approach to examine the perceptions of key informants regarding the factors influencing the implementation of school-based vision screening in Ontario, and the role of nurses in supporting implementation.  Semi-structured interviews were conducted with parents (n = 3), optometrists (n = 3), clinical research personnel (n = 2), public health staff (n = 5), school staff (n =2), and community vision program personnel (n = 2) from across Ontario.  The Consolidated Framework for Implementation Research (CFIR) was used to frame the analysis.  The following factors were found to influence vision screening implementation: (1) student and parent needs; (2) presence of external partnerships; (3) dedication of tangible resources; (4) presence of internal networks and communications; and (5) the cost, complexity, and perceived quality of the vision screening program.  Participants reported that public health nurses’ knowledge and skills, and their position within schools, communities, and the health system, facilitated vision screening implementation.  This study suggests that a comprehensive and coordinated approach is necessary when implementing school-based vision screening programs.  Future research examining vision screening implementation should consider the use of the CFIR to guide all phases of the implementation process, and explore the experience and perspectives of vision screening implementation of students, non-English speaking families, and those who had experienced failed vision screening.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: In Canada, nearly 25% of school-aged children have vision problems.  In 2018, the Ontario Ministry of Health and Long-Term Care passed a law requiring that all senior kindergarten students have their vision screened.  This study used a qualitative descriptive approach to explore the perceptions of key informants regarding factors influencing implementation of school-based vision screening in Ontario, and the role of nurses in supporting implementation of this practice.  The Consolidated Framework for Implementation Research was used to frame the analysis.  The results of this study suggest that a comprehensive and coordinated approach is necessary when implementing school-based vision screening programs.  Furthermore, participants reported that public health nurses’ knowledge and skills, and their position within schools, communities, and the health system, facilitated vision screening implementation. Therefore, public health units are encouraged to strategically utilize public health nurses when implementing vision screening.  Practice, policy, education, and future research implications are discussed.


title: Adaptation to Alkylation Mutagenesis in Escherichia coli

contributor:
Golding, G. Brian
Biology

subject:
alkylation mutagenesis
escherechia coli
e coli

abstract: This thesis is missing a page between pages 60 and 70, and three pages between pages 70 and 81. Since the pages are not all numbered, the specific page numbers cannot be determined. Theses missing pages are not in the other copies of the thesis. -Digitization Centre

abstract: Replicate isogenic populations of E. coli were propagated and maintained for over 4000 generations in order to investigate the adaptation of E. coli to increased levels of the mutagen methanesulfonic acid ethyl ester (EMS). Control "C" cell lines were propagated through daily serial culture in the absense of any mutagenic treatment. EMS adapted cell lines "E" / "e" were propagated through daily serial culturing and treated daily with 25Jul of EMS following serial dilution. Mutation frequency and survival assays conducted in this investigation strongly suggest that prior long-term low dose exposure to EMS results in significantly higher levels of resistance to the lethal and mutagenic effects of larger challenge doses of EMS relative to long-term evolved control cell lines "C". In addition, both survival and inhibition disk assays suggest a cross adaptive response between EMS and MNNG, showing enhanced survival and reduced growth inhibition zones in cells adapted to EMS and challenged with MNNG. Preliminary competition experiments suggest relative fitness for the EMS adapted cell lines ( "E" / "e") compared to the "C" control cell lines in both the presence of EMS. Unexpectedly the fitness estimates also suggest a higher relative fitness for the "E" / "e" EMS adapted cell lines in the absence of EMS treatment, suggesting that the EMS specific adaptation may also result in improved fitness in novel environments. Despite the adaptive advantage for the "E" / "e" cell lines suggested by the fitness estimates, the results from the competition experiments are insignificant due to the high degree of variability among replicate fitness estimates. Attempts to induce the adaptive response repair pathway were not successful in either the control "C" or the EMS adapted "E" / "e" cell lines suggesting that enhanced resistance seen in the adapted "E" / "e" cell lines could likely be a result of enhanced activity of the constitutive transferase Ogt and the constitutive glycosylase Tag. The ada and the ogt genes encode the induced and the constitutively-active DNA methyl transeferases in E. coli. As such they appeared to be the most likely candidates for genetic changes responsible for the enhanced resistance to the lethal and mutagenic effects of large doses of alkylating agents in the long-term EMS adapted "E" / "e" cell line. However, the DNA sequences analyzed for the ogt and the ada genes for both the long-term evolved control E. coli cell line "C" and the long-term-evolved EMS adapted "E" / "e" cell line indicate no sequences differences between these two cell lines. Previous studies have primarily observed E. coli's ability to phenotypically acclimate over very short time intervals to EMS. This analysis has shown that long-term genetic adaptation to low doses of EMS results in enhanced resistance to both the lethal and mutagenic effects of larger challenge doses of EMS.

abstract: Thesis

abstract: Master of Science (MS)


title: Effect of Age on Autonomic Neurocardiac Function in Healthy Males and Females

contributor:
McCartney, Neil
Kinesiology

subject:
autonomic
neurocardiac
neurocardiac function
autonomic neurocardiac function

abstract: Background & Rationale: Heart rate variability analysis has provided scholars and clinicians with a powerful non-invasive tool for the assessment of cardiac autonomic function in health and disease. However, the interpretation of the information provided by this technique would be greatly facilitated by a more precise definition of 'normality'. The purpose of this investigation was to examine the alterations in cardiac autonomic function across a broad spectrum of ages in healthy males and females. Methods: Heart rate variability data during 20 min supine rest and orthostatic stress (10 min free standing) as well as 24-hour ambulatory Holter ECG recordings were obtained on 123 healthy volunteers (72 female/51 male). Subjects were arbitrarily classified into five categories: pediatric (PED; 5-12 yrs, n=22, 12 female:10 male), adolescent (ADO; 13-17 yrs, n=21, 13 female:8 male), adult (ADU; 18-30 yrs, n=26, 13 female:13 male), middle aged (MDA; 31-60 yrs, n=24, 15 female:9 male) and elderly (ELD; 61+ yrs, n=30, 19 female:11 male) age groups. Power spectral analysis (autoregressive) was determined from supine and standing acute data sets as well as six evenly spaced one hour periods during the Holter recording. Time domain variables (pNN50, R-MSSD, SDNN, SDANN & SDNN index) were derived from the 24-hour data sets. Results: Heart rate in the supine position declined progressively from age 5 years to 30 years but showed no further changes thereafter. In contrast, power spectral measures remained relatively stable in the younger age groups but subsequently exhibited a significant shift toward a higher LF:HF area signifying sympathetic dominance (or vagal withdrawal) in the MDA and ELD subjects. The heart rate and spectral response to orthostasis was most dramatic in the ADO subjects and exhibited a progressive decline in the three older age groups. With respect to the time domain variables, those parameters characterizing short term variability (pNN5O & R-MSSD) were stable in the PED, ADO and ADU subjects but significantly diminished in the two older age groups. In contrast, time domain variables encompassing long term (SDNN & SDANN) and intermediate (SDNN index) oscillations exhibited age-related increases reaching peak values in the ADU subjects and declining progressively thereafter. Power spectral analysis of the six evenly spaced one hour periods of the 24-hour holter recording revealed a diminished circadian rhythm for the majority of the frequency domain indices in the two oldest age groups. Conclusions: The present investigation revealed substantial evidence supporting the existence of an age dependent change in cardiac autonomic function. However, this process appeared to act homogeneously across gender. The similarity of these age dependent changes to those previously observed in pathological conditions commonly associated with autonomic neuropathy serves to emphasize the importance of HRV research aimed at the establishment of reference standards in healthy populations and a more precise definition of 'normal' autonomic neurocardiac function.

abstract: Thesis

abstract: Master of Science (MSc)


title: Chemical Modeling of Zinc Enzymes

contributor:
Lock, C. J. L.
Chemistry

subject:
chemical modeling
zinc
zinc enzymes
enzyme

abstract: This thesis is missing pages 9, 39, 108-110. The pages are not in the other copies of the thesis. -Digitization Centre

abstract:
This work describes efforts towards creating chemical models for a variety of zinc
based metalloenzymes. A background on the current progress of modeling zinc enzymes
is presented, as is a brief review of zinc biochemistry. The structure of triaquo(tris-2-pyridylphosphine)nickel(ll) dinitrate is presented and compared with its zinc analogue. Both structures have octahedral geometry with no unusual bond lengths. The synthesis and characterization of bis(2,4,5-tribromoimidazole)(diaquo)zinc(II). (II) is also presented in this work. A similar compound, Zn(Im)2 (III) was also prepared in this work. Both compounds were characterized by X-ray crystallography, IR spectroscopy, and elemental analysis. Neutron crystallography was used to characterize (II) as a peraquo species. Both (II) and (III) possess tetrahedral geometry about the zinc atom. (III) is multiply catenated and cannot be considered as a discrete molecular species. The pKa2 of 2,4,5-tribromoimidazole, the organic ligand in (II), was measured and found to be 10.7(2).
Bond valence theory was used to analyze (II). Extended Huckel molecular orbital
calculations were carried out on (II). (II) was compared with a variety of other zincimidazole compounds. It was discovered that (II) has unusually small carbon-nitrogen-carbon angles within its tribromoimidazole rings. It is uncertain whether this feature is because of the coordination of the tribromoimidazole rings to the zinc atom, or
whether it is an inherent feature of the tribromoimidazole rings. A copper analogue of (II) has also been synthesized and has been tentatively assigned the formula Cu(lmBr3)2(OH2)2 . X-ray characterization of this compound has not yet been accomplished.

abstract: Thesis

abstract: Master of Science (MS)


title: Sexual Dimorphism in a Joint-Nesting Plural Breeder, the Smooth-Billed Ani (Crotophaga ani)

title: Sexual Dimorphism in Smooth-Billed Anis

title: Sexual Selection in a Joint-Nesting Plural Breeder, the Smooth-Billed Ani (Crotophaga ani)

contributor:
Quinn, James
Biology

subject:
sexual selection
sexual dimorphism
joint-nesting
plural breeder
joint-nesting plural breeder
smooth-billed ani
Crotophaga ani

abstract: Sexual selection has been investigated in many different systems but information is lacking in joint-nesting species. Both sexual dimorphism and possible signals of quality were explored in this study for a joint-nesting plural breeder, the smooth-billed ani (Crotophaga ani). Sexual dimorphism can be examined for a species in an attempt to reveal particular traits that might be under sexual selection and the strength of sexual selection on them. In mate choice decisions, sexually selected traits may be used by the choosy individual to assess the quality of potential mates. These honest traits need to reveal the condition and genetic quality of the individual accurately. For example, it has been proposed that plumage colour reveals condition, and more specifically parasite resistance in birds. This study explores sexual size dimorphism and dichromatism in smooth-billed anis, as well as the ability of their feather colour to reveal body condition (measured as residuals from a regression of mass versus body size), body size, and parasite numbers. Additionally, because anis are group living birds, this study investigated whether group size had an effect on parasite numbers. Anis from a population in southwestern Puerto Rico were measured for size, their feathers were collected and analyzed using a spectrometer, and ectoparasites were collected by dustruffling. For all size traits measured, males were significantly larger than females. Males also had more exaggerated bill depths (relative to body size) than females. There were no differences between the sexes for all colour morphometries, except tail saturation; females had more saturated tails than males. While no decisive conclusions can be drawn as to why the dimorphic traits are different between males and females, sexual selection may have played a role. The relationship between log10 average lice numbers per group and group size was positive, but not significant. In male smooth-billed anis, plumage colour was not related to lice or mite numbers, or body size and body condition. Plumage colour was also not related to body condition and size in females. Additionally, ectoparasites did not have an effect on male body condition. Plumage may not only be an inaccurate signal of parasite resistance or body size and body condition in the smooth-billed ani, but ectoparasites may not even have a negative effect on their host. The inability to find significant results may have been affected by other factors, such as feather wear and the age of individuals. These results warrant a more detailed look into the social behaviour of the group-living smooth-billed ani.

abstract: Thesis

abstract: Master of Science (MSc)


title: Niagara Township: A Study in Land Utilization

subject:
niagara township
land utilization

abstract:
Thesis
Bachelor of Science (BSc)


title: A Radio Frequency Mass Spectrometer

contributor:
Duckworth, H
Physics

subject:
radio
frequency
radio frequency
spectrometer
mass spectrometer
radio frequency mass spectrometer

abstract: This thesis describes a non-magnetic mass spectrometer incorporating the following components: a heated filament source, an electrostatic energy analyser, and a time-of-flight velocity analyser. The last component measures the time required for an ion to go between two small condensers by means of a radio frequency voltage applied to the condensers. If an ion passes successively through both condensers when the field in them is zero, it is collected and detected. It is then possible to relate the e/m to the frequency of the applied voltage when the energy of the ion and the distance between the centres of the condensers is known. Theory is presented which permits the calculation of resolution and current intensities. The values so obtained are realized experimentally.

abstract: Thesis

abstract: Master of Science (MSc)


title: An Algebraic Foundation of the Calculus of Alternating Differential Forms

title: The Calculus of Alternating Differential Forms

contributor:
Banaschewski, B
Mathematics

subject: algebra

subject: algebraic foundation

subject: calculus

subject: alternating differential forms

subject: differential forms

abstract: This thesis is concerned with the calculus of alternating differential forms on a manifold. It establishes that this calculus is of a purely algebraic nature by developing its precise analogue for an arbitrary commutative algebra with unit over a field.

abstract: Thesis

abstract: Master of Science (MSc)


title: Spatial and Temporal Interactions between Shape Representations in Human Vision

contributor:
Sekuler, Allison B.
Bennett, Patrick J.
Psychology

subject:
Shape perception
Psychophysics
Radial frequency contours
Human vision
Lateral masking

abstract:
The human visual system has the remarkable capacity to transform spatio-temporal patterns of light into structured units of perception. Much research has focused on how the visual system integrates information around the perimeter of closed contours to form the perception of shape. This dissertation extends previous work by investigating how the perception of curvature along closed-contour shapes is affected by the presence of additional shapes that appear close to the target shape in space and/or time.

Chapter 2 examined the ability of shape mechanisms at representing low frequency curvature in the presence of a higher frequency component along contours in multi-shape displays. We found that additions of high amplitude, high frequency curvature along a contour path can modulate the strength of interaction observed between shapes, and thus attenuates the contribution of low frequency components in interactions between neighbouring contours. Chapter 3 examined what curvature features are of importance in modulating phase dependent interactions between shapes. Results revealed that phase-dependent masking does not depend on curvature frequency, but is related to sensitivity for phase shifts in isolated contours, and is affected by both positive and negative curvature extrema.  Computational simulations aimed at modelling the population responses evoked in intermediate shape processing areas (i.e., V4) suggest sensitivity to shifts in phase of shapes is not well captured by such a population code, and therefore alternative explanations are required. Chapter 4 examined how sensitivity to curvature deformations along the contour of a closed shape changes as a function of polar angle, angular frequency, and spatial uncertainty.  Results show that human observers are, at first approximation, uniformly sensitivity to curvature deformations across all polar angles tested, and this result holds despite changes in angular frequency and spatial uncertainty. Chapter 5 examined whether the strength of spatial masking between shapes is affected by the presentation of a temporal mask. Our results demonstrate that a temporal mask affected spatial masking only when it preceded the target-mask stimulus by 130-180ms. Furthermore, the effects of a temporal mask on spatial masking are approximately additive, suggesting that separate components contribute to spatial and temporal interactions between shapes.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: An Exploration of Patient Perspectives on Factors Affecting Participation in Stroke Rehabilitation

contributor:
Harris, Jocelyn
Rehabilitation Science

subject:
stroke rehabilitation
participation
facilitator
barrier
qualitative
interpretive description

abstract: Though patient participation is recognized as an important element of rehabilitation, few studies have used a qualitative lens to specifically examine factors influencing patient-participation in stroke rehabilitation. Thus, the purpose of this work was to explore factors perceived by service users to influence their participation in hospital-based stroke rehabilitation activities and to use this information to generate knowledge relevant for the clinical context of stroke rehabilitation. The following research gaps provided rationale for this work: 1) no published studies from the patients’ perspective on influencers of participating in hospital-based stroke rehabilitation programs, and 2) limited studies about influences on participation in hospital-based stroke rehabilitation. The first manuscript (chapter two) was designed to specifically address these gaps while the second manuscript (chapter three) was developed to highlight important findings surrounding rehabilitation intensity from chapter two. This thesis has discussed a number of patient-perceived barriers and facilitators to participating in stroke rehabilitation, which the final chapter conceptualizes into a framework of personalized rehabilitation representing a patient-centred approach to providing rehabilitation that encourages patient participation. Together, this thesis contributes knowledge about: 1) patient perspectives on factors affecting participation in stroke rehabilitation, 2) promoting patient participation, 3) shortcomings in closing the evidence-to-practice gap with respect to therapy intensity during inpatient stroke rehabilitation, and 4) insights into an exploratory framework of personalized rehabilitation developed from service users’ perspectives of stroke rehabilitation. In addition, this work emphasizes a call to action for the delivery of user-centered stroke care, specifically in regard to rehabilitation intensity during inpatient stroke rehabilitation. The implications of this work are directed at stroke rehabilitation providers as well as policy makers and stroke health system planners in order to develop appropriate and effective services and strategies for optimal recovery and successful implementation of best practice recommendations.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Rehabilitation is a crucial part of recovery after stroke and patient participation is recognized as an important element of rehabilitation. A less explored perspective is patients’ experiences participating in stroke rehabilitation and barriers/facilitators to participation. This study interviewed individuals who participated in stroke rehabilitation to ask about factors influencing their participation. Eleven individuals were interviewed, and four key themes were identified as barriers and/or facilitators to patient-participation in stroke rehabilitation: 1) environmental factors, 2) components of therapy, 3) physical and emotional well-being, and 4) personal motivators. A sub-theme, amount of therapy, was explored further and this work draws attention to the rehabilitation intensity evidence-to-practice gap apparent as a prevalent issue in Canada and elsewhere. This exploration of patients’ experiences and factors perceived as influencing participation can help to shape the development of strategies to facilitate participation in rehabilitation and improve implementation of existing recommendations to maximize recovery after stroke.


title: New Determinations of the Atomic Masses of Zn66, Zn67, Zn68 and Ni58

subject: Zn66

subject: Zn67

subject: Zn68

subject: Ni58

subject: zinc-66

subject: zinc-67

subject: zinc-68

subject: nickel-58

subject: atomic mass

subject: atomic masses

abstract: Masses have been determined by means of new mass spectrographic comparisons for the nuclides Zn66, Zn67, Zn68 and Ni58. The values obtained are compared with earlier ones from another laboratory. Mass differences have been obtained, which, together with those from nuclear reaction experiments, provide a basis for the adjustment of former mass values. These adjustments have lead to better agreement between mass determinations and nuclear disintegration data.

abstract: Thesis

abstract: Master of Science (MSc)


title: Diffraction, Total Reflection, and Refraction of 3.2 cm. Electromagnetic Waves by a Dielectric Prism and a Dielectric and Metal Semicylinder

title: Total Reflection of Microwaves by a Prism and Semicylinder

contributor:
McLay, A
Physics

subject:
total reflection
reflection
microwaves
prism
semicylinder
dielectric prism
dielectric semicylinder
metal semicylinder
dielectric and metal semicylinder
diffraction
refraction
electromagnetic waves
3.2 cm electromagnetic waves
3.2 cm. electromagnetic waves
dielectric

abstract: A description of several experiments carried out to study the existence of evanescent waves behind totally reflecting dielectric surfaces is given in this thesis. Chapter I describes the experimental apparatus used to generate and measure the electromagnetic radiation. A detailed description of the construction of the radiating horns used and the casting of a plastic prism is also given. Chapters II and III give the results of two experiments in the region behind a totally reflecting face of the plastic prism and similar effects noted behind a lucite semicylinder with its plane face towards the source of radiation. Near field diffraction patterns of this cylinder with its plane face towards the source, away from the source, and parallel to the axis of radiation are also given. The above three cases are compared with results obtained by coating the semicylinder with aluminum foil.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Geography of Albion Township

subject:
albion township
geography

abstract:
Thesis
Bachelor of Arts (BA)


title: Petrology and Geochemistry of Some Igneous Intrusives in the Back River Volcanic Complex, District of MacKenzie, Northwest Territories

contributor:
Clifford, P. M.
Geology

subject:
petrology
geochemistry
igneous
back river volcanic
northwest territories

abstract:
Granitic intrusives and a zoned gabbroic dyke situated within the Back River Volcanic Complex were mapped and studied. Petrography and geochemical analyses were performed on selected specimens. Chemican variation diagrams suggest that the granites may have been derived
from the fractional crystallization of a single parent magma. In order of decreasing age, these granitic units are defined as follows: 1. Hornblende Quartz Syenite 2. Granite 3. Quartz Monzodiorite A zoned gabbro/quartz gabbro dyke cuts the granites. Pyroxene and plagioclase are the dominant minerals of this dyke, and are found to vary antipathetically throughout the central portions of the dyke. Chemical studies of this system suggest that the zoning may be the result of a series of multiple injections from different source magmas.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Green Cosmic Dreams: Utopia and Ecological Exile in Women's Exoplanetary Science Fiction

contributor:
Grise, Catherine
English and Cultural Studies

subject: speculative fiction; science fiction; ecocriticism; feminism; ecology; climate change; anthropocene; indigenous literature

abstract:
Exile is not only an appropriate lens through which to view the ecological, social, and psychological destabilizations of the Anthropocene, but also as a state which can inspire the flexibility and creativity necessary to survive difficult times through ecologically-connected states of being. Examinations of literary alienation and responses to this condition in this project are confined to women’s exoplanetary science fiction which anticipates the experience of physical and emotional separation from planet Earth. In contextualizing experiences of exile from our planet of origin and the expressions of such in women’s science fiction literature, this project interrogates selected cultural movements in human relationships to the environment, separation from the environment, and resistances to that estrangement through the concept of exile.
Chapter One considers the Western myth of the lost paradise and the ways in which the Garden of Eden has contributed to Western conceptions of environmental and human perfection and belonging and the persistent idea of working one’s way back to Eden. In contrast to this idea, I present analyses of James Tiptree Jr.’s A Momentary Taste of Being and Molly Gloss’s The Dazzle of Day, both of which illustrate that working toward perfection is an ultimately stagnating and often violent move.
Chapter Two, mounting further challenges to the Western paradise and its reverberations through environmental discourse, frames science fiction’s initial acquiescence to narratives of colonization and later feminist rejection of these narratives. Analyzing the connections between colonial structures, the environment, and beings considered nonhuman or less-than-human in Ursula K. Le Guin’s The Word for World is Forest and Joan Slonczewski’s A Door Into Ocean, this chapter describes the psychological and emotional estrangements necessary to survive and resist colonization and its ecological destruction and contextualizes experiences of exile. Chapter Two argues that though exile is often a destructive process, it can form a basis with which to resist entrenched social structures.
Finally, Chapter Three examines the ways in which Indigenous science fiction, working in a different historical and cultural context than that of the Western feminist texts discussed in the previous two chapters, emphasizes an experience of and approach to exilic destabilizations which centres on what Gerald Vizenor calls “survivance”—the survival of colonial genocide and resistance to further colonial impositions. While Lee Maracle’s “The Void” and Mari Kurisato’s “Imposter Syndrome” utilize exoplanetary distance from Earth’s ecosystems to illustrate modes of survivance, they also demonstrate the ways in which relations to the land are maintained through interrelational rather than hierarchical subjectivities, and demonstrate the resilience intrinsic to interconnected ecological systems.
In sum, the estranged position of women’s exoplanetary science fiction emerges as critical of the hierarchical structures which have resulted in widespread ecological collapse, and imparts the perspective necessary not only to challenge those structures but also to survive their destabilizations.

abstract: Dissertation

abstract: Doctor of Philosophy (PhD)


title: Evaluation of Machine Learning-based Methods for Continuous Water Quality Data Analysis

contributor:
Sekerinski, Emil
Copp, John
Computer Science

abstract: Wastewater treatment facilities are increasingly installing sensors to monitor water quality. As these datasets have increased in size and complexity, it has become difficult to identify abnormal readings in a timely manner either manually or using simple rules that might have been sufficient previously. Two ammonia sensors were installed at the Dundas Wastewater Treatment Plant in November 2017. The collected ammonia concentration data shows a daily pattern. A learning-based method is implemented in this thesis to identify any readings which violate this daily pattern. The data points which were predicted to be anomalous were qualitatively ranked based on the severity and the likelihood of being faulty. The result of the learning-based method was evaluated and compared to other traditional detection methods.

abstract: Thesis

abstract: Master of Science (MSc)


title: Exploring the implementation and delivery of primary care services for transgender individuals: An Ontario case study

subject:
transgender
primary care
nursing

abstract:
Transgender individuals represent one of the most marginalized and underserved populations in healthcare. Issues such as discrimination, lack of practitioner experience and knowledge, and a deficiency of services have contributed to the healthcare barriers experienced by transgender individuals. There is a lack of literature demonstrating how primary care services are delivered to transgender individuals and a need for research that helps advance our knowledge about the delivery and implementation of primary care services for this population. This thesis explores how primary care services are delivered and implemented from a perspective that acknowledges the complexities of the healthcare needs of the transgender population.
A multiple-case study design was used to explore the implementation and delivery of primary care for transgender individuals in Ontario within different delivery models of primary care and through diverse roles of primary care team members. Normalization Process Theory, an implementation theory and conceptual framework, was used in this study to understand and explain the dynamic processes that occur during implementation of interventions in healthcare, and guide data collection and analysis. Three cases representing different models of primary care delivery in Ontario were identified, all of which provide primary care services to transgender individuals. These models included a solo physician Fee-For-Service practice, a Family Health Team and a Community Health Centre. The multiple sources of data collection strategies used were interviews, a survey, documental evidence, and field notes. Participants included multiple members of the primary healthcare team, such as practitioners, clinical support staff and executive directors. This study helps to advance our knowledge of the delivery and implementation of primary care services for transgender individuals. Implications for nursing practice, including highlighting the need for curricula changes and understanding the nursing role, are discussed.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Primary care, such as a family doctor, is where people get day-to-day healthcare. Worldwide, transgender individuals encounter barriers to appropriate healthcare, in particular access to practitioners who understand their health needs. This thesis aims to explore how primary care services are delivered to transgender individuals in Ontario, through a study that examined different ways services are provided, from a family doctor working alone in a clinic to a clinic with a team of practitioners (e.g., family doctors, nurse practitioners, nurses, counsellors). Interviews with practitioners, a survey, and clinic documents showed that primary care for transgender individuals is part of regular primary care services; whether delivered via a rapid access specialty clinic or embedded into regular primary care services, study participants were easily able to integrate primary care for transgender individuals into their routine work. However, evidence also highlighted the need for practitioners to obtain specialized knowledge of transgender needs.


title: Oneida Township

subject: geography Oneida township

abstract:
Thesis
Bachelor of Arts (BA)


title: Aerial Interpretation of Muskeg: A Critical Analysis of Form Features in the Canadian Muskeg Complex

title: Aerial Interpretation of Muskeg

contributor:
Radforth, N. W.
Biology

subject:
muskeg
canadian muskeg complex
aerial interpretation
form feature

abstract: This thesis is missing page 355 which is not in any other copy of the thesis. -Digitization Centre

abstract: The ontogeny of a specific high altitude (30,000') airform pattern was investigated. The possibilities of using this pattern, and certain related phenomena which appear with it,for sub-surface ice prediction was demonstrated. For the purpose of laying out the general background of the controls of paludification, as they affect indirectly the pattern development, a rather detailed account of the geomorphology, geology and climate of the study areas was given. The summaries of these accounts demonstrate their effect on pattern evolution. These background data as a foundation for a more specific account of the developmental processes of the airform pattern were given as based on abiotic and biotic interplay in the development. Finally in order to demonstrate universal application of aerial interpretation of muskeg a brief comparison of the analogous conditions of paludification and pattern in Finnish and Canadian muskeg was given.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Molecular Signalling Responses to High-Intensity Interval Exercise: Effects of Carbohydrate Availability

contributor:
Gibala, Martin
Kinesiology

subject:
molecular signalling
high intensity interval exercise
high intensity interval training
hiit
carbohydrate availability

abstract: This thesis is missing page 63 from all copies. -Digitization Centre

abstract: Manipulating carbohydrate (CHO) availability has been shown to alter acute exercise-induced changes in metabolic gene transcription and training-induced changes in oxidative capacity. The present study examined the effect of CHO availability on signalling pathways linked to mitochondrial biogenesis in response to high-intensity interval exercise (HIE). We hypothesized that reduced CHO availability would augment phosphorylation of AMP-activated protein kinase (AMPK), calcium/calmodulin-dependent kinase II (CaMKII), and p38 mitogen-activated protein kinase (p38) in response to HIE. Ten active men performed two experimental trials in random order, separated by 2:1 wk. During each trial, subjects performed two HIE sessions separated by 3 h (AM and PM sessions). Exercise sessions consisted of 5 x 4 min cycling bouts at a workload that elicited approximately 90% V02peak, with 2 min rest periods. Between sessions, subjects ingested -1.2 g CHO/kg b.w./h (HI-HI) or a taste-matched, non-energetic placebo (HI-LO). Muscle biopsies and blood samples were obtained before (Pre) and after (Post) the AM and PM HIE sessions. AMPK, CaMKII, and p38 MAPK phosphorylation increased from AM Pre to AM Post (p<0.01). During the PM exercise session, p38 phosphorylation increased in the HI-LO condition (-4.5-fold, p<0.001), whereas the HI-HI condition remained unchanged. PM HIE significantly increased CaMKII phosphorylation independent of condition, while no exercise or condition-mediated AMPK effects were observed. In summary, restricting CHO availability following an acute session of HIE augmented the exercise-induced increase in p38 phosphorylation during a subsequent HIE session. It remains to be determined whether chronic changes in p38 MAPK signalling are mechanistically linked to altered skeletal muscle remodelling observed after CHO-restricted exercise training.

abstract: Thesis

abstract: Master of Science (MS)


title: Coastal Geomorphology Playa Guinoes, Guanacaste Province Costa Rica

subject:
coastal geomorphology
playa guiones
guanacaste province
costa rica

abstract: This thesis is missing page 123, no other copy of the thesis has this page. -Digitization Centre

abstract:
This research provides the first detailed study of the coastal geomorphology of Playa Guiones, Guanacaste Province Costa Rica. Playa Guiones is located within a tropical wet/dry climate necessitating that field work is completed in both seasons to ensure a broad understanding of the coastal characteristics. The research commenced February 2005 with site selection and preliminary field work. During June 2005 a detailed real-time
kinematic GPS survey and beach inventory (sediment, rock and vegetation) was conducted. During a third field session a comparison was made between the current observed coastal characteristics and those observed during the two other field seasons. Playa Guiones is composed of primarily fine grained sand and carbonate shell material. Rock samples collected adjacent to the southern headland on the rocky shore platform consisted of limestone and finely grained, interbedded sandstone and siltstone. Adjacent to the northern headland on the rocky shore platform the rock consisted of sandstone. Playa Guiones displays some temporal variability which may be linked to the wet and dry seasons. On initial inspection Playa Guiones appears to have the characteristics of an embayed beach but more detailed inspection illustrates that Playa Guiones has many characteristics that are contradictory to a typical embayed beach. Although Playa Guiones lies on a convergent margin it has many characteristics of a divergent margin coast. This study is significant because it provides important baseline information for future work. Playa Guiones is located on the Nicoya Peninsula where a large seismic gap,
which last fully ruptured in 1950, is known to exist. The baseline data will be very useful subsequent to any future earthquake event for measuring change that occurs along this rapidly developing coastline. The methodologies employed in this study provide much more detail information than is typically collected in gee-indicator studies which often only measure several profiles along a beach to create a digital elevation model rather than the 3 m gridding distance used in this study.

abstract: Thesis

abstract: Master of Science (MS)


title: Digital Signal Processing and Display of Lung Sounds

contributor:
Pengelly, L. David
Electrical Engineering

subject:
digital signal processing
display of lung sounds
lungs
lung sounds
signal processing

abstract: Presented here is an examination of the issues surrounding the analysis of lung sounds and their display. The project is aimed at providing a visual representation of the information that a physician gleans from auscultation of the lungs. Such a tool would be of benefit to those who are hearing impaired and also in teaching auscultation. A second goal is to provide a tool that will allow the examination and quantification of lung sounds thus permitting linkage between the acoustic events and their physical causes. The project is divided into two tasks. The first is the isolation of the wheezes and crackles; the second is their display. The isolation problem is difficult due to the variance in the frequency characteristics of the sounds; wheezes may appear anywhere in a two thousand hertz band and crackles also display a varying spectrum. The difficulty in separation is further compounded by the spectral overlap of the two. These problems preclude any 'simple' filter solution. In order to separate the sounds, filtering methods based on exploiting the statistical differences namely the stationarity of the wheeze and non-stationarity of the crackle are utilized. Of the several methods attempted, the most promising was the Adaptive Line Enhancement process when driven by the Least Mean Squares adaptive algorithm. An important criteria for being able to display the sounds was to access their temporal information. Accomplishing this with the standard short time Fourier transform precludes adequate resolution to identify the frequency characteristics of crackles. Display of the crackle information was facilitated by the use of high resolution time-frequency methods based on Cohen's Class of time-frequency representations. These methods are able to simultaneously provide high time and frequency resolution. A method for automatic adjustment of the parameters involved in the process was developed in order to yield the best display possible.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Role of RpoS in Global gene Regulation and Virulence in Escherichia Coli

title: Role of RpoS in Escherichia coli

contributor:
Schellhorn, Herb
Biology

subject:
RpoS
gene regulation
virulence
Escherichia coli

abstract: This thesis is missing page 53, no other copies have this page. -Digitization Centre

abstract:
Bacterial adaptation to changing conditions and to the host environment requires coordinated changes in gene expression that permit more efficient utilization of metabolites and increased survival. An important form of gene control is through the use of alternative sigma factors that direct RNA polymerase to recognize a distinct group of genes. One such sigma factor is RpoS, which is widely present in Proteobacteria including many serious human pathogens. As a key stress response regulator, RpoS plays an important role in adaptation, but its effect on virulence varies in different species. RpoS contributes to virulence through either enhancing survival against host defense systems or directly regulating expression of virulence factors in some pathogens, while RpoS is dispensable, or even inhibitory, to virulence in others. The primary objective of this study is to understand the mechanism of RpoS control in gene expression and pathogenesis of Escherichia coli. This thesis first describes the characterization of RpoS regulon in laboratory and pathogenic E. coli strains by transcriptome profiling analysis.  Comparison of RpoS regulons identifies a core set of RpoS-controlled genes as well as strain-specific groups of genes, including many implicated in virulence. The contribution of RpoS to enteropathogenesis in vivo was tested using a Citrobacter rodentium (CR)mouse infection model that is commonly used to simulate E. coli infection in human intestine. Mutations in rpoS result in reduced colonization and delay in mortality, indicating RpoS is important for full virulence. Clinical and natural E. coli isolates exhibit variable abilities in stress resistance and virulence, which is partly attributable to attenuating polymorphisms of rpoS commonly found in E. coli populations. A possible mechanism responsible for the occurrence of rpoS polymorphisms in pathogenic E. coli is addressed. Using a group of representative enterohemorrhagic E. coli strains, we report that growth-enhanced mutants can be selected during growth on succinate and other poor carbon sources under both aerobic and anaerobic conditions. The majority of these mutants carry nonsense or missense mutations in rpoS. Phenotypic microarray analysis reveals that rpoS mutations result in increased utilization of 92 nitrogen and 8 carbon sources. Therefore, the occurrence of rpoS polymorphisms may increase the fitness of the population as a whole for better nutrient scavenging. In conclusion, RpoS may be viewed as a transient regulator that orchestrates the temporal expression of a large regulon for better adaptation under specific conditions including natural and host environments. Under conditions not requiring RpoS, its functions can be turned off through decreasing expression, rapid proteolysis, inhibition of RpoS activity, or selection of attenuating mutations. The final part of this thesis reviews the distinct and niche-dependent involvement of RpoS in virulence of many rpoS-bearing pathogens.
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abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: A Geographical Study of Hullett Township

subject:
geographical study
Hullett township

abstract: This thesis is missing pages 34 and 57, no other copies of this thesis have these pages. -Digitization Centre

abstract: Thesis

abstract: Bachelor of Arts (BA)