title: Characterization of Estrogen Receptors in the Liver Cytosol of the Rainbow Trout, Salmo Gairdneri

title: Estrogen Receptors of Rainbow Trout Liver

contributor:
Chen, T
Biology

subject:
estrogen
rainbow trout
liver

abstract: Two types of estrogen binding sites were found in the rainbow trout liver cytosol, using the equilibrium binding assay. The higher affinity, lower capacity type I site had a Kd range of 0.53-5.9 nM and a concentration range of 14-95 pmoles/g protein. The lower affinity, higher capacity type II sites had a Kd range of 65-265 nM and a concentration range of 20-180 pmoles/g protein. These estrogen binding sites are both bound by ^3H-moxestrol. The estrogen binding sites in the serum were also examined and two components were found with the higher affinity component having a Kd of 2.63 nM and a concentration of 25 pmoles/g protein while the lower affinity component had a Kd of 79 nM and a concentration of 200 pmoles/g protein. However, these estrogen binding components are unable to bind the synthetic estrogen, DES, and therefore cannot account for either of the binding components found in the liver cytosol which bind DES as readily as 17β-estradiol. The cytosol estrogen binding sites bind non-estrogens in addition to estrogens. Sucrose gradient centrifugation of the cytosol yielded two estrogen binding peaks, one at 4.4S, the other at 3.7S. The heavier peak contained binding sites able to bind progesterone as well. Gel filtration of the cytosol also resulted in two peaks, one at 43,000 daltons, the other at 33,000 daltons. Again the heavier peak could be partially competed out by progesterone. The half life of these binding components was 60 minutes at 37°C, while no decrease in binding was observed after 4 hours at either 0 or 12 0 c. After 17β-estradiol treatment in vivo type I sites (relative to type II sites) were 74% depleted after 8.5 hours and 40% depleted after 24 hours. Finally, o,p'-DDT and p,p'-DDT, components of technical grade preparations of the insecticide DDT were both able to compete for estrogen binding sites in the rainbow trout liver cytosol and therefore may be able to affect the expression of estrogen inducible genes.

abstract: Thesis

abstract: Master of Science (MSc)


title: The molecular evolution of sex and reproduction related genes, hybrid male sterility and spectiation in the drosophila melanogaster complex

contributor:
Singh, R.S
Biology

subject: heterogametic, chromosomes, sterility, phostzygotic isolation

abstract:
Haldane's rule, which states that the heterogametic sex is preferentially afflicted if
one of hybrid sexes is sterile or inviable, is a general pattern in all animals that possess
sex chromosomes. The hybrid sterility component of this rule is especially important
because hybrid sterility is involved in the onset of postzygotic isolation. Accumulating
evidence on the fast evolution of individual sex genes have stimulated us to hypothesize
that the fast evolution of sex genes may be the force underlying the excess of hybrid
heterogametic sterility. This study tests the evolutionary patterns of sex genes in
comparison to non-sex genes, as a general group. The divergences between a group of 19
sex genes and 20 non-sex genes from X chromosome were compared between D.
melanogaster, D. mauritiana, D. simulans, and D. sechellia using PCR-RFLP. Within
species polymorphism data were also obtained for D. simulans and D. mauritiana. The
results show a significantly higher divergence for sex genes than non-sex genes, while a
comparable level of intraspecific polymorphism was revealed in both groups. Among the
sex gene group, genes related to male reproduction appear to evolve faster than femalereproductive
genes. The evolution of both sex and non-sex genes conforms to the neutral
theory under Tajima's test and HKA test. The faster evolution of sex genes supports the
fast-sex theory as an explanation for the hybrid sterility component of Haldane's rule.
Localization of some examples of hybrid sterility genes is crucial to ultimately untangle the genetics of hybrid sterility. The car region of D. mauritiana, which has been shown to harbor genes that confer full effect of hybrid sterility in the D. simulans genetic background, was introgressed into the D. simulans genome by continuous backcrosses.
Recombination mapping analysis, taking advantage of molecular markers, revealed that
at least two regions are capable of causing hybrid sterility in this species group. The
phenotypes of hybrid testes were examined during the backcross process.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Midline Glial Cell Lineage in the Post Embryonic Fruit Fly Drosophila melanogaster

contributor:
Jacobs, J. Roger
Biology

subject: ultrastructure, glia, drosophila melanogaster

abstract:
This study investigated the position, ultrastructure and life
history of glia in the midline of the Drosophila melanogaster Central
Nervous System (CNS) by using enhancer traps (AA142, X81,
argoswll, pointed1277) and reporter constructs (EEl, slilacZ 1.0,
slilacZ 4.5) as glial-specific markers. Previous work has established
that glia are necessary for proper formation and morphogenesis of
longitudinal and commissural axon tracts, and axon ensheathment
(Jacobs, 1993; Klambt et al., 1991; Jacobs and Goodman, 1989). By
the end of embryogenesis there are three midline glial (MG) cells
remaining in each segment (Sonnenfeld and jacobs, in press) which
this study verifies. In the third instar larval MG cells proliferate to
24 cells per segment as followed with the E. coli lacZ expressing
pointed1277 strain. These E. coli lacZ expressing pointed1277 MG
cells begin dividing 57 hours after hatching as seen with 5
-bromodeoxyuridine and hydroxyurea treatment. Some MG genes
cease midline expression before MG proliferation (seen with EEl,
X81), others (seen with AA142) continue to be expressed until the
beginning of MG proliferation. Only the argoswll, slilacZ 1.0, slilacZ
4.5, and pointed1277 expression strains continue E. coli lacZ
expression to the end of the larval stages. In the first larval stage a
few perineuropilar glia begin to express the E. coli lacZ gene and
increase to 400 cells per CNS in the third ins tar as seen in the
pointed1277 marker strain. pointed1277 EM micrographs show
that E. coli lacZ labeled cells have a glial-like ultrastructure. There
-
was no co-localization of the E. coli lacZ expression in pointed12 77
and an anti-RK2 (repo) antibody in third instar larvae. In
pointed1277 pupae the MG cell E. coli lacZ expression stops after 48-
72 hours and the prerineuropilar signal stops after 24 hours. In
newly hatched pointed1277 adults perineuropilar E. coli lacZ
expression is present with a cluster of 12 cells in the center of the
neuropil. To summarize, after embryogenesis, in the pointed1277
marker strain, the MG cells begin dividing after 57 hours and the E.
coli lacZ gene expression ends after the second day of the pupal
stage. In the first instar, perineuropilar glia begin to label for the E.
coli lacZ product and this expression ends by one day into the pupal
stage, with re-appearance in the adult CNS.

abstract: Thesis

abstract: Master of Science (MSc)


title: NOVEL CARRIER PROTEIN AND ITS APPLICATION TO A RESPIRATORY SYNCYTIAL VIRUS ANTIVIRAL PEPTIDE

title: DEVELOPMENT OF AN ALBUMIN-BINDING DOMAIN CARRIER AND A NOVEL PEPTIDE MIMETIC ANTIVIRAL FOR RESPIRATORY SYNCYTIAL VIRUS

contributor: Medical Sciences (Molecular Virology and Immunology Program)

subject:
Respiratory Syncytial Virus
Peptide Mimetics
RNA-Dependent RNA-Polymerase
Human Carrier Molecules

abstract:
Background: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection and hospitalization in children worldwide. With no vaccine or antivirals available for the routine prevention or treatment of RSV, an effective RSV antiviral is required. Previous studies have shown that the RSV nucleocapsid complex (NC), phosphoprotein (P), and large polymerase (L) are essential for the replication and survival of RSV since they form the core of the RNA-dependent RNA polymerase (RdRp) complex. Thus, these proteins are viable targets for novel RSV antivirals.
Objective: The Mahony laboratory has previously shown that 20 µM of a peptide mimetic composed of the 21 terminal amino acids of the RSV phosphoprotein (RSVP220-241) fused to an HIV-1 Tat cell penetrating peptide (CPP), a hexa-histidine (His) tag, and the Escherichia coli (E. coli) maltose binding protein carrier (MBP) molecule was sufficient to attenuate RSV A and B replication in vitro by approximately 90 and 80%, respectively. We evaluated the fusion of this His-MBP-Tat-RSVP220-241 mimetic to a more suitable carrier molecule, an albumin-binding domain (ABD), for future use in vivo. In addition, we designed a novel antiviral mimetic composed of the 30 terminal amino acids of the RSV A P protein (RSVP212-241), which are involved in binding both L polymerase and NC complexes, fused to a CPP consisting of Tat or nine arginine residues (Arg9), a His-tag, and the MBP carrier. We evaluated the activity of His-MBP-Tat-RSVP212-241, Tat-His-MBP-Tat-RSVP212-241, and His-Arg9-MBP-RSVP212-241 mimetics in vitro and hypothesized that a mimetic designed to target both L and NC interactions would be a more effective RSV antiviral than the original His-MBP-Tat-RSVP220-241 mimetic.
Methods and Results: The Gateway® Cloning System was used to create expression vectors containing His-, GST-, or His-MBP-ABD-Tat-RSVP220-241 and His-MBP-Tat-RSVP212-241, whereas inverse PCR and both the In-Fusion® and Gateway® Cloning systems were used to generate expression vectors containing Tat-His-MBP-Tat-RSVP212-241 and His-Arg9-MBP-RSVP212-241. The fusion proteins were expressed, purified by affinity chromatography, and evaluated in vitro. No soluble protein was obtained for the ABD constructs. His-MBP-Tat-RSVP212-241 was toxic and not internalized by LLC-MK2 cells, whereas only 0.26 mg of Tat-His-MBP-Tat-RSVP212-241 was purified. We were able to show that His-Arg9-MBP-RSVP212-241 was non-toxic, internalized, and interacted with the RSV nucleoprotein (N) in a GST pull-down experiment. Furthermore, His-Arg9-MBP-RSVP212-241 attenuated RSV A replication and progeny production by 94.8 and 93.33% at 200 µM, respectively. We demonstrated 50.7 and 49% inhibition of RSV A replication and progeny production at 20 µM, respectively. We showed that inhibition of viral replication by 25 µM His-Arg9-MBP-RSVP212-241 was not significantly different from inhibition by 20 µM His-MBP-Tat-RSVP220-241. Thus, in this thesis we were unable to show that His-Arg9-MBP-RSVP212-241 was a more effective RSV antiviral.
Conclusion: The ABD was not a suitable carrier molecule for use with our fusion protein mimetics. However, RSV P protein mimetics that target interactions with the NC complexes and L polymerase are a novel and viable antiviral strategy. We showed that a His-Arg9-MBP-RSVP212-241 mimetic was non-toxic, internalized, and interacted with the RSV N protein in vitro. Furthermore, we showed that at 200 µM this novel mimetic could attenuate RSV A replication and progeny production in vitro by 94.8 and 93.3%, respectively. Further studies are required to characterize the construct, increase its bioactivity, and identify a suitable human carrier molecule for future evaluation in vivo.

abstract: Thesis

abstract: Master of Science (MSc)

abstract: Worldwide, respiratory syncytial virus is a leading cause of lower respiratory infection and hospitalization in children. Nearly all children are infected with the virus by the young age of two. However, respiratory syncytial virus also causes a significant amount of illness and death in the elderly and in immunocompromised individuals. Furthermore, repeated infections by the virus are common throughout life in all populations. With the lack of a vaccine or treatment for this viral infection, an effective antiviral against RSV is required. In this thesis, we developed and evaluated a novel RSV antiviral therapeutic peptide that targets proteins of the viral replication machinery. Since the replication machinery is required for respiratory syncytial virus survival, we hypothesized that infection could be attenuated by preventing formation of the replication machinery. Furthermore, since small protein therapeutics are often cleared quickly from the human body, we investigated human carrier molecules that could be attached to the antiviral protein for stabilization within the body.


title: Automated Scanning Microelectrode Analysis of Epithelial K^+ Transport in Malpighian Tubules of Drosophilia melanogaster: Evidence for Spatial and Temporal Heterogeneity

title: Automated K^+ Scanning Microelectrode Analysis

contributor:
O'Donnell, M
Biology

subject:
Drosophilia melanogaster
epithelial K^+
spatial heterogeneity
temporal heterogeneity

abstract: Malpighian (renal) tubules of the fruit fly Drosophila melanogaster consist of three functional domains: a non-secretory distal segment, a secretory main segment and a reabsorptive lower segment. In this study a computer-controlled micropositioning system and a self-referencing K^+ microelectrode were used to measure K^+ concentration gradients of extracellular unstirred layers associated with specific epithelial domains. K^+ fluxes were calculated from the measured gradients. This is the first time: that an accurate assessment of the concentration gradients of the unstirred layer of Drosophila melanogaster could be assessed due to the enhanced sensitivity of this self-referencing technique over conventional ion-selective microelectrodes. The technique permits high resolution spatial and temporal mapping of the flux patterns in response to stimulation or inhibition of ion transport. Variations in K^+ transport over time and at different sites suggest that transport is non-uniform within any one functional domain.

abstract: Thesis

abstract: Master of Science (MSc)


title: Telemedicine Adoption in Ontario

contributor:
Norm, Archer
eHealth

subject: Telemedicine eHealth Adoption Utilization

abstract:
Abstract

Telemedicine (TM) is a term that describes the delivery of healthcare over distances.  TM has evolved along with communication technology, creating a model of TM healthcare delivery that is constantly changing.

The primary advantage of TM is that it gives physicians the ability to reach out to patients remotely, providing healthcare to remote or isolated locations, thus greatly reducing the need for patient travel.  The physician is the primary stakeholder of TM, but to date there is a paucity of research related to TM utilization by physicians.  Specifically, it is not known whether TM is an efficient healthcare tool that allows more patients to be seen by a physician than could normally be seen face to face (F2F), hence increasing the potential volume of patient care.

This study describes the adoption and utilization characteristics within a “real” medical environment (the Ontario Ministry of Long-term Health Care) by analyzing established medical practices.  Using OHIP data, this study shows TM utilization trends among physicians who were responsible for a large portion of TM patient activity within their respective specialties between 2011 and 2013.  By understanding TM usage by physicians, the ministry can provide programs and incentives that may increase TM adoption, thus providing more efficient healthcare to underserviced populations in Ontario.

The top three specialties from 2008-2013 using TM in Ontario were found to be General and Family (G&F) practice, Internal Medicine and Psychiatry, with G&F physicians using TM primarily to increase practice volumes for addiction medicine.  Within the Internal Medicine specialty, TM appears to be a tool for healthcare delivery that helps offset some F2F events.  Within the specialty of Psychiatry, many TM events seemed to have been performed by psychiatrists who have smaller volumes of F2F visits compared to their peers.

Trends in TM show that for some specialties and types of clinical events, TM can be used to see more patients than physicians could normally see when restricted to F2F visits only, thus reducing the number of F2F visits within some practices.

abstract: Thesis

abstract: Master of Health Sciences (MSc)


title: Noise Generation in the Gas Wiping Process

contributor:
Ziada, Samir
Mechanical Engineering

subject: noise generation, gas wiping process, galvanized sheet steel, jets, acoustic modes

abstract:
 This thesis investigates the characteristics of noise generation in the gas wiping process, including the effects of the various parameters manipulated in the process and countermeasures used to reduce noise levels. The process of gas wiping is used in many industrial applications such as drying of pulp and paper, photograph production and some high performance cooling applications. One of the most important industrial applications of gas wiping is the production of hot-dipped galvanized sheet steel. Gas wiping is a very efficient and reliable process to control coating thickness and uniformity of galvanized steel products, and can be used for very high line speeds and production rates. Changing the various process parameters such as the jet to strip distance (z), the jet slot width (h), plenum pressure (P) and jet inclination angle (α) allows manufacturers to control the coating thickness and quality of the finished product.

 The gas wiping process is also responsible for the generation of very high levels of noise, which can be a factor in limiting the overall production rates and indirectly increase production costs for manufacturers. To maintain a constant coating thickness as the line speed and production rate is increased, the plenum pressure supplied to the jets and thus the incident jet velocity must be increased, or the jet-to-strip distance must be decreased. Noise production in the gas wiping process is acknowledged to be proportional to the incident jet velocity and inversely proportional to the jet-to-strip distance. Thus, for a given coating thickness, as the production rates increase, the noise
generated by the process must also increase. Ergonomic restrictions in the workplace, which limit the exposure to high sound pressure levels and audible acoustic tones, may indirectly limit the maximum line speed for a steel sheet with a given coating thickness. This limitation is particularly relevant to the production of high quality automotive sheet steels, which often have very thin coating thicknesses and have higher than normal coating uniformity tolerances, which necessitate the use of high plenum pressures and small jet-to-strip distances.

 At present, the state of knowledge for noise generation in the gas wiping process
is very limited. Only two previous investigations have been devoted to this problem, and the experiments for these studies have only modeled specific individual cases, with no attempt at a comprehensive modeling of noise in this process. For the current study, measurements have been performed in both an actual manufacturing environment and on a scaled galvanizing simulator in a laboratory environment. A comprehensive set of experiments over a wide range of gas wiping parameters was performed in order to provide a broad overview of noise generation in the gas wiping process and allow for process optimization to reduce noise and allow higher production rates and efficiency. The creation of noise maps, modeling the overall sound pressure level and tone intensity for gas wiping as function of the various operating parameters of the process, as well as a set of equations and models to determine the frequency of discrete acoustic tones are presented. A full analysis of the frequency response, as well as the acoustic modes generated in various jet impingement regions has also been provided.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Characterization of Cytochrome P450 and a Putative Cytochrome P450 Gene in Drosophila melanogaster

title: Cytochrome P450 in Drosophila melanogaster

contributor:
Morton, R.
Biology

subject:
cytochrome P450
drosophila melanogaster

abstract: Cytochrome P450 was examined in both insecticide resistant and insecticide susceptible strains of Drosophila melanogaster. Much higher levels were observed in the resistant strain IIID when compared to the susceptible strain Canton S. This increase appeared to be the result of an overproduction of a few existing forms. Two heme-staining microsomal proteins found in strain IIID were identified as putative cytochrome P450 isozymes. Polyclonal antibodies produced against these two proteins were used in the immunoanalysis of microsomal proteins from both strains. A lambda gtll cDNA expression vector library was created by inserting cDNA fragments from a Drosophila lambda gt10 library into lambda gtll arms. The library was screened with the polyclonal antiserum. Three clones were isolated, of which one, gtll-Al, was most highly reactive with the antiserum. Analysis of the gtll-Al lysogen indicated a 130 kd fusion protein was produced of which 16 kd was coded for by the cDNA insert. A .5 kb cDNA insert was isolated from the clone as part of a 1.5 kb Kpnl/EcoRl fragment and was used in the analysis of Drosophila genomic DNA and total RNA. Southern analysis revealed an EcoRl polymorphism existed between strain IIID and Canton S. RNA analysis suggested strain IIID produced more coding message for the Al insert in the larval and adult stages than did Canton S.

abstract: Thesis

abstract: Master of Science (MSc)


title: Rotational Foam Molding of Metallocene Catalyzed Polyethylene

contributor:
Vlachopoulos, John
Chemical Engineering

subject: rotational foam molding, metallocene, catalyzed, polyethylene, chemical blowing agents, polymer

abstract:
 The foaming process has received increased attention by the rotational molding industry
in recent years. The use of metallocene catalyzed polyethylenes for producing a cellular structure is a new development in rotational molding. The objective of this work was to investigate the effects of different chemical blowing agents, resin properties and processing conditions on the structure of foamed metallocene polyethylene and obtain a fundamental understanding of the parameters governing the foam structure and part properties.

 An experimental study was conducted to produce metallocene polyethylene foams in dry-blending-based rotational foam molding. The physical and cell structure properties of the final foamed parts were examined. The critical processing parameters that optimize the foam structure have been identified through adjustments to the molding conditions.

 The foaming performance of exothermic and endothermic chemical blowing agents were examined and it was revealed that selecting an appropriate chemical blowing agent was crucial as the foam structure depends significantly on the properties of the blowing agent. Exothermic blowing agents resulted in greater foam density reduction compared to endothermic blowing agents.

 The effect of rheological properties on the foaming process and foam properties was also examined. Rotomolding experiments were performed in monolayer and skin-foam moldings. Observations indicated that the final foam properties were profoundly
influenced by the rheological properties of the polymer materials. There was a good correlation between the foam properties produced in both monolayer and two layer moldings. It was discovered that polymer materials with higher extensional viscosity could provide a promising foaming performance at different processing conditions.

 The effect of the surface tension of the polymer materials was investigated. It was found that type of reaction of the blowing agent (exothermic/endothermic) and composition of gas generated determine whether the surface tension of the resin contributes to the trend of changes in foam properties.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Modulators of Spitz Group/Der Signaling Differentially Affect Midline Glia Survival and Differentiation

contributor:
Jacobs, J.
Biology

subject:
spitz group
midline glia

abstract:
In Drosophila melanogaster, the genes of the spitz group and of the DER signaling pathway function together to communicate localized developmental signals to
the cells of many tissues. The embryonic midline glia (MG), a mesectodermal lineage
essential to proper morphogenesis of the axon tracts of the ventral nerve cord (VNC),
depend on spitz group signaling for survival and differentiation. Loss of function of any of the spitz group genes or of DER results in a decrease in the number of MG and
subsequent defects in the formation of the axon tracts. These defects include a medial
collapse of the longitudinal axons and fusion of the posterior and anterior commissures. Ectopic expression of Rhomboid, a putative seven pass transmembrane protein which is a member of the spitz group, generates supernumerary glia. Directed expression of DER^AB87T, an activated form of the Drosophila EGF receptor, sSpi, a diffusible ligand, or Ras^v12, a constitutively activated variant of a monomeric G-protein, have the same effect on MG number. It is proposed that the spitz group/DER signaling pathway act to promote survival of MG precursor cells. In addition, expression of Draf and pntP1 are found to increase the number of surviving supernumerary MG, however these signaling molecules are determined to be less
effective at promoting the survival of the MG, based on their decreased ability to generate supernumerary MG. Furthermore, a subset of the supernumerary MG created in embryos in which Draf has been misexpressed appear to be incompletely differentiated or insulated from normal programmed cell death (PCD) by expression of this transgene. The effect of multiple cytoplasmic signaling pathways, activated by spitz group/DER signaling, on MG survival and differentiation is examined and discussed. Ectopic expression of rhomboid generates supernumerary MG. This process is suppressed by mutation of genes of the spitz group or of DER. Evidence that Rho
functions upstream of Spi, Star and DER is presented. The implications of these data and their relevance to previously published models which propose the molecular actions of the spitz group/DER pathway genes are discussed. Finally, the role of spitz group/DER signaling in the activation of downstream target genes is explored. Overexpression of these genes results in increased expression of pointed, argos, and rhomboid. A model for spitz group function in signal amplification is proposed.

abstract: Thesis

abstract: Master of Science (MSc)


title: Selection of Organophsophate Resistant Drosophila Melanogaster over Twelve Generations

contributor:
Morton, R.A
Biology

subject: iso-chromosomal, Drosophila melanogaster, haplotypes, malaxon, insectiside

abstract:
Twenty-five different iso-chromosomal III lines of Drosophila melanogaster, with known
haplotypes, were mixed and selected on malaoxon over twelve generations in order to find the
importance of variants already present in the Drosophila genome relative to new mutations in
the evolution of insecticide resistance.
Measurements of mixed function oxidase and acetylcholinesterase activities, as well as
insecticide resistance, were made over the twelve generations of selection and on the the
iso-chromasomal III lines extracted after the selection was completed. These measurements were
compared to those made of the twenty-five lines before selection. This comparison indicated that
52A, one of the origional twenty-five lines, may have been selected during this experiment.
Comparisons of a possible cytochrome P-450 produced by a previously selected line of
Drosophila called D23, and the DNA which is probably responsible for the production of this
P-450, with the microsomal proteins and total genomic DNA of the selected lines were made
using the techniques of Western and Southern blotting. The results of these procedures
suggested that the mechanism of resistance used by the selected lines was not the same
mechanism of resistance used by the D23 line.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Cytostomal Apparatus of Tetramitus Rostratus

contributor:
Dingle, A.D
Biology

subject: microtubular, eukaryotic, tetramitus rostratus, cystomal apparatus

abstract:
Microtubular systems are an integral and essential
element of eukaryotic cells. Many of these systems display
linkages between the microtubules. The aim of this study was
to investigate one such system, the cytostomal apparatus of
Tetramitus rostratus. It was hoped that some insight could
be gained into the nature of inter-microtubule linkages as
well as investigating conditions for possible isolation via
differential solubilization.
The cytostomal apparatus consists of two sheaves of
microtubules that originate at the basal bodies and extend
through two-thirds of the length of the cell, apparently
supporting the gullet. These microtubules are extremely
stable: they are cold stable, calcium stable and
griseofulvin/colchicine stable. They are highly cross-linked
by fine filaments. These "linkers" have an average length of
107 nm. Linker width varies from the mid-portion (6 nm) to
the ends (12 nm). In this and other respects they are
similar to the highly contested microtrabecular lattice. The
linkers were observed in positively stained samples and in
thin-sections. Glutaraldehyde was found to have a very
destructive effect on the linkers. A combination of
paraformaldehyde and glutaraldehyde (2.25\/0.5\) was found
not to have this effect over times that are normally used for
primary fixation.
Another component of the cytostomal apparatus is the
system of longitudinal filaments that is especially wellrevealed
with high salt (0.25M NaCl or KCl) extraction.
Since this extraction solubilizes the microtubules, it may
allow the longitudinal filaments to be isolated. These
filaments may be related to the tektin filaments found in
flagellar microtubules. In addition, a novel set of crossfibres
is found to originate at the juncture of the two
sheaves of microtubules and fan out across two-thirds of the
width of the apparatus. These fibres were found to be
especially stable in urea which may, again, allow for their
isolation and characterization.
The linkers have been investigated for motility.
Linker length was measured after treatment with ATP (which
successfully reactivated the flagellar dynein) and after
treatment with ATP followed by treatment with calcium (which
efficiently halted all reactivated movement of the flagella).
The length of the ATP treated linkers was very close (5 nm)
to the control linkers and their morphology was
indistinguishable. The length of the calcium treated linkers
was considerable shorter (20 nm) but the morphology suggested
that this was artifactual rather than due to a physiological
cause.

abstract: Thesis

abstract: Master of Science (MSc)


title: Effect of Thermal Ageing on the Corrosion and Stress Corrosion Cracking of Type 310S Stainless Steel in Supercritical Water

contributor:
Kish, Joseph
Zheng, Wenyue
Materials Science and Engineering

abstract:
This thesis documents a multi-faceted investigation of the effects of thermal ageing-induced microstructure instability on the corrosion/oxidation and stress corrosion cracking (SCC) susceptibility of Type 310S stainless steel in supercritical water (SCW). The motivation for this study is the exiting knowledge gap associated with these two material performance aspects, which are considered essential to help guide the selection of a fuel cladding material for application in the Canadian Gen IV Supercritical Water-Cooled Reactor (SCWR) design concept. The focus was placed on the pressurized light water coolant outlet conditions (25 MPa SCW at 500-550 °C) considering that the likelihood for corrosion and SCC in combination with microstructure instability resulting from thermal ageing is presumed to be relatively high. The working hypotheses being that (i) Cr-rich intermetallic precipitate formation would serve to bind alloyed Cr, thus preventing the formation of protective Cr-rich oxide scales required for suitable corrosion/oxidation performance and (ii) Cr-rich grain boundary precipitate formation would serve to enhance SCC susceptibility by either sensitizing (chemical factor) or embrittling (mechanical factor) grain boundaries.
Two limiting thermal ageing treatments were evaluated. The ‘S’ treatment, designed to ‘sensitize’ the microstructure, induced significant Cr-rich M23C6 carbide precipitation on the grain boundaries concomitant with the development of adjacent Cr-depleted zones. This limiting case represented a short-term exposure condition for the fuel cladding. The ‘TT’ treatment, designed to ‘mechanically embrittle’ the microstructure, induced significant Cr-rich sigma (σ)-phase precipitate formation on the grain boundaries and within the grains. This limiting case represented a long-term exposure condition for the fuel cladding. The ‘SA’ treatment, designed to solution anneal the microstructure, served as the baseline microstructure exhibiting a low extent of microstructure instability.
Long term thermal ageing of Type 310S austenitic stainless steel at the maximum expected fuel cladding temperature operation temperature range of Canadian-SCWR concept to produce the TT material induced significant σ phase precipitate formation within the grains and on grain boundaries, all without the concomitant adjacent Cr-depleted zone formation. Such microstructure instability did not have a major effect on the general corrosion/oxidation susceptibility since the thermally-aged material exhibited a similar weight gain and oxide scale structure after exposure in 25 MPa SCW at 550 °C as the solution annealed material, albeit after relative short exposure time (500 h). The likely reason for this was the discontinuous nature of the σ phase precipitate formation.
The remaining research conducted was aimed towards investigating the effect of thermal ageing on the intergranular SCC susceptibility of Type 310S stainless steel in SCW. A ‘first approximation’ attempt to isolate and assess the potential contribution of the likely chemical factor (sensitization) and mechanical factor (embrittlement) to the overall cracking mechanism. The overall ranking in terms of an increasing degree of sensitization, as determined by Double Loop – Electrochemical Potentiokinetic Reactivation (DL-EPR) testing, of three heat-treated materials studied is:  SA ~ TT << S. The ranking reflects the controlling role played by Cr-depleted zones, which were only observed in the S material. The absence of a Cr-depleted zone accompanying the σ phase grain boundary precipitates in the TT material indicates that the treatment time of a 1000 h was sufficient to “self-heal” the Cr-depleted zone, which was expected to have formed during the early stages of the treatment at 800 °C.
Bulk uniaxial tensile measurements revealed both the S and TT material were embrittled relative to the SA material. The associated fractography revealed that the grain boundaries in the S material were sufficiently embrittled to cause intergranular fracture, whereas the grain boundaries in the TT material were not sufficiently embrittled to cause intergranular fracture. Classic micro-void formation involving a M23C6/matrix decohesion process occurs on the S material grain boundaries. Intergranular facture occurs as these micro-voids coalesce on the grain boundaries. In contrast, micro-void formation involving cracking of the large hard σ phase precipitates occurs on the TT material grain boundaries. Transgranular ductile fracture of the softer austenite matrix occurs as these micro-voids coalesce across the grains as the softer grains need to accommodate the stress after fracture of hard σ phase precipitates.
The effect of thermal ageing on the SCC susceptibility of Type 310S in SCW was evaluated using the Slow Strain Rate Test (SSRT) technique, straining samples to 10% in 25 MPa SCW at 500 °C. The results were interpreted in light of the likely contributions of the chemical (sensitization) and mechanical (embrittlement) factors as revealed by the above mentioned research. The sensitized material exhibited well-developed intergranular SCC after straining to 10% (about 7.5% plastic strain). The TT material exhibited neither intergranular nor transgranular SCC susceptibility under the same exposure conditions. The localized deformation model for SCC initiation was combined with a void-assisted film-cleavage model for SCC propagation to explain the SCC susceptibility of thermally-aged Type 310S stainless steel in SCW.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Robust Position Sensorless Model Predictive Control for Interior Permanent Magnet Synchronous Motor Drives

contributor:
Emadi, Ali
Electrical and Computer Engineering

subject:
Electric motor drives
Position sensorless control
Interior permanent magnet machine
Parameter estimation
Observability
Model predictive control

abstract:
This thesis focuses on utilizing the persistent voltage vector injections by finite control
set model predictive control (FCSMPC) to enable simultaneous estimations of
both position and parameters in order to realize robust sensorless interior permanent
magnet synchronous machine (IPMSM) drives valid at the entire operating region
including no-load standstill without any additional signal injection and switchover.
The system (here, IPMSM) needs to meet certain observability conditions to
identify the parameters and position. Moreover, each combination of the parameters
and/or position involves different observability requirements which cannot be
accomplished at every operating point. In particular, meeting the observability for
parameters and position at no-load standstill is more challenging. This is overcome
by generating persistent excitation in the system with high-frequency signal injection.
The FCSMPC scheme inherently features the persistent excitation with voltage vector
injection and hence no additional signal injection is required. Moreover, the persistent
excitation always exists for FCSMPC except at the standstill where the control
applies the null vectors when the reference currents are zero. However, introducing
a small negative d axis current at the standstill would be sufficient to overcome this
situation.The parameter estimations are investigated at first in this thesis. The observability is analyzed for the combinations of two, three and four parameters and experimentally
validated by online identification based on recursive least square (RLS) based adaptive
observer. The worst case operating points concerning observability are identified and
experimentally proved that the online identification of all the parameter combinations
could be accomplished with persistent excitation by FCMPC. Moreover, the effect
of estimation error in one parameter on the other known as parameter coupling is
reduced with the proposed decoupling technique.
The persistent voltage vector injections by FCSMPC help to meet the observability
conditions for estimating the position, especially at low speeds. However, the
arbitrary nature of the switching ripples and absence of PWM modulator void the
possibility of applying the standard demodulation based techniques for FCSMPC.
Consequently, a nonlinear optimization based observer is proposed to estimate both
the position and speed, and experimentally validated from standstill to maximum
speed. Furthermore, a compensator is also proposed that prevents converging to
saddle and symmetrical (  ambiguity) solutions.
The robustness analysis of the proposed nonlinear optimization based observer
shows that estimating the position without co-estimating the speed is more robust
and the main influencing parameters on the accuracy of the position estimation are d
and q inductances. Subsequently, the proposed nonlinear optimization based observer
is extended to simultaneously estimate the position, d and q inductances. The experimental
results show the substantial improvements in response time, and reduction
in both steady and transient state position errors.
In summary, this thesis presents the significance of persistent voltage vector injections
in estimating both parameter and position, and also shows that nonlinear
optimization based technique is an ideal candidate for robust sensorless FCSMPC.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Limits to Sphagnum Growth in an Abandoned Mined Peatland

contributor:
Waddington, J. M.
Geography

subject: sphagnum growth, abandoned mined peatland, ecosystem, crank wires, litter bags, decomposition, photosynthesized

abstract:
 The net ecosystem CO2 exchange and Sphagnum net primary production of an abandoned block-cut bog were measured in the field and in the laboratory using gas exchange techniques. Environmental variables were measured concurrently. Seasonal Sphagnum growth and decomposition were determined using crank wires and litter bags.

 The bog was a net source of CO2 during the summer months. While, Sphagnum did grow over the study period, the Sphagnum net primary production was offset by peat respiration. Sphagnum net primary production and net ecosystem CO2 exchange at the abandoned block-cut bog are within the ranges found for natural peatlands.

 Sphagnum photosynthesis was greatest at wet sites and at the start and end of the study period when the water table was higher and the temperature was cooler. Ericaceous shrub cover strongly affected Sphagnum growth. Sites with vascular plant cover photosynthesized at approximately twice the rate of sites where cover was removed.

 Laboratory results indicate that drying and wetting cycles negatively affect Sphagnum net primary production and net ecosystem CO2 exchange. Sphagnum and peat respiration increased 4 to 14 fold upon rewetting whereas Sphagnum
photosynthesis did not recover until 20 days of saturation.

 The results emphasize the importance of stable moisture availability for the development of a new acrotelm. The peatland will likely remain a source of CO2 until the acrotelm is able to counterbalance the peat respiration.

abstract: Thesis

abstract: Master of Science (MSc)


title: Molecular Genetic Analysis of a Brown-Headed Cowbird (Molothrus Ater) Population

contributor:
Gibbs, H. Lisle
Biology

subject: molecular genetic, brown-headed, cowbird, population, molothrus ater, mtDNA

abstract:
 The mtDNA control region of the Brown-headed Cowbird (Molothrus ater) was sequenced and comparisons made at the inter- and intraspecific level. Comparison of the control region with that of another Passerine, Darwin's Finch (Geospiza scandens), revealed a high degree of both gross and fine scale structural similarity. At the nucleotide level, this comparison confirmed the presence of a hypervariable domain which evolves at rate approximately 5
times faster than coding mtDNA as well as a relatively conserved central domain which evolves at rate comparable to coding mtDNA. Both species displayed the typical avian mtDNA
gene organisation previously described by Desjardins and Morais (1990, 1991) and Quinn and Wilson (in press). However, the most notable structural feature in common was the apparent deletion of the entire left hypervariable domain (CR1). At a finer scale, Conserved Sequence Block (CSB1) was perfectly conserved between cowbird and finch and Conserved Sequence Block 2 (CSB2) was 78% similar. The hypervariable right domain showed the largest degree of
sequence divergence between species, 22.7%, while the central domain and phe-tRNA showed much less divergence, 6.47 and 4.41% respectively. At an intraspecific level, in 524 bases of sequence from 31 nestling cowbirds from a population at Delta, Manitoba, only 3 variable sites were detected which defined a total of 4 haplotypes. The average percent sequence divergence for this population was 0.27%. This level of variation within the cowbird population is low compared to other vertebrate populations. This relative lack of variation is largely attributable to the loss of the left hypervariable domain (CR1). The loss of CR1 will limit the control region's usefulness for high resolution population level studies but may make it a useful marker for phylogenetic studies within the class Aves.

abstract: Thesis

abstract: Master of Science (MSc)


title: Hemodynamic Responses of Pre/Early-Pubertal, Mid-Pubertal and Late-Pubertal Girls to Exercise in the Heat

contributor:
Bar-Or, Oded
Human Biodynamics

subject: hemodynamic responses, exercise, heat, females, physical development

abstract:
 During exercise in a hot climate, it has been reported that children respond with a greater shift in blood volume from the central to the peripheral circulation, compared with adults. This can lead to inadequate central circulation, and early cessation of activity in children. No studies have considered if a transition in this hemodynamic response occurs during puberty in females. This study measured hemodynamic responses in pre/early (PEP), mid- (MP), and late- (LP) pubertal girls. Twenty-seven 9- to 16- year-old healthy girls (n=9, each group) cycled in a climatic chamber set at 35 ± 1°C and 50 ± 5% relative humidity for two 20-min bouts (10-min rest in between and a 10-min rest at the end). Cardiac output was
measured upon chamber entry, in the middle and at the end of each exercise bout. Forearm blood flow (FBF) was measured upon chamber entry, 3 minutes after exercise bout 1 (E1) and bout 2 (E2) and at the end of rest 1 (R1) and rest 2 (R2). Overall, there was no significant group difference in the central hemodynamic (e.g. cardiac index, stroke volume index) responses to exercise in the heat. However, FBF among the three groups at R1 was almost significantly different (p=0.06), such that it was lower in LP than in PEP and MP. FBF in LP
also tended to decrease from E1 to R1 (7.91±1.06 to 6.1±0.83 ml•100ml-1•min-1) and from E2 to R2 (9.47±1.47 to 8.26±1.20 ml•100ml-1•min-1). In contrast, PEP and MP showed little change in FBF at all time points. These findings strengthen the notion that there is a maturity-related decrease in forearm blood flow from pre- to late-puberty. In conclusion, under the conditions of the present study, there were very few differences in the hemodynamic responses of pre-, mid- and late- pubertal girls. It is possible that the transition to an adult-like hemodynamic response does not occur until later in a girl's physical development.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Effect of Sex-Accessory Gland Removal on Strange-Male-Induced Pregnancy Disruptions in Mice

contributor:
deCatanzaro, D.
Psychology

subject: gland removal, sex-accessory, strange-male-induced, pregnancy disruptions, mice

abstract:
 Early pregnancy in mammals can be disrupted by numerous stimuli. In particular, exposure to males which did not sire the litter disrupts early pregnancy in previously inseminated female mice. This is known as the Bruce effect. Evidence suggests that this effect is mediated by chemical emissions (pheromones) from the males. Castration of the males eliminates the effect whereas testosterone replacement restores it. This has suggested that
androgen-dependent male accessory glands might be responsible. In particular, the preputial, vesicular and coagulating glands seem likely candidates for subserving the Bruce effect since they have been implicated in a variety of social behaviors.

 In these experiments, inseminated females were each housed below either 1) two males which had undergone preputial gland removal or, 2) two males which had undergone vesicular-coagulating gland removal or, 3) two males which had undergone preputial, vesicular and coagulating gland removal or 4) two males which had undergone sham surgery. In each case, males which had undergone gland removal disrupted pregnancy in inseminated females to the same extent as did intact males. Histology showed no regeneration of the glands. These results suggest that none of these major androgen-dependent male accessory glands is responsible for pheromonal emissions involved in the Bruce effect.

abstract: Thesis

abstract: Master of Science (MSc)


title: Conspecific Influences on Diet Choice in the Norway Rat (Rattus Norvegius): The Role of Early Social Isolation

contributor:
Galef Jr., B. G.
Psychology

subject: conspecific influences, diet choice, Norway, rats, early social isolation

abstract:
 There is a large literature discussing social influences on diet choices in rats. However, the ontogeny of social influences on diet choices is poorly understood. Early experiences have dramatic affects on the development and expression of future behaviors.

 The present research investigates whether early social experience altered the susceptibility to social influences on diet choices in juvenile Norway rats (R. norvegicus). Interactions with dam and siblings between parturition and weaning are prominent features of early rats development. It was hypothesized social behavior developed during this period and rearing pups in social isolation would disrupt the development of normal social behaviors.

 Conspecifics influence the diet preferences of others by socially interacting. The first experiment investigated whether demonstrators could influence diet choices of rats with no social experience. In terms of diet preferences, demonstrators influenced both normally reared rats and rats reared in social isolation.

 Interactions with conspecifics and exposure to diet odors without social contexts influenced the diet choices of 21 day old pups. Only interactions with conspecifics influenced diet choices of 28 day old rats. Rearing rats in social isolation may delay the onset of social specificity and the results of experiment 1 may have been the product of two different mechanisms. The second experiment investigated whether rats reared in social isolation attended to socially specific cues or to general olfactory
cues. Exposure to flavored diets in a non-social context did not influence diet choices of rats reared in social isolation or normally-reared rats. Thus early social interactions do not appear to be necessary for demonstrator rats to influence the diet choices of other rats.

abstract: Thesis

abstract: Master of Science (MSc)


title: In Vitro Studies of freshwater Teleost Ionoregulation in the Common Killifish (Fundulus heteroclitus), Nile Tilapia (Oreochromis niloticus) and Rainbow Trout (Onocorhynchus mykiss)

title: In Vitro Studies of Teleost Ionoregulation in Freshwater Killifish, Tilapia and Trout

contributor:
Wood, C.
Biology

subject:
in vitro
killifish
tilapia
rainbow trout
teleost ionoregulation

abstract: Largely through the use ofin vitro preparations there is now a generally accepted theory for ion transport for the seawater (SW) gill. However, to date there is no generally accepted freshwater (FW) model for the mechanisms of NaCl transport in the teleost gill. By using an Ussing chamber approach with the opercular epithelia of Fundulus heteroclitus and Oreochromis niloticus, and the urinary bladder of Oncorhynchus mykiss, all acclimated to FW, we hoped to establish one as a possible model for the study of FW ion regulation. FW Fundulus opercular epithelia displayed a serosal negative transepithelial potential (Vₜ) of-43.9 mV, transepithelial conductance (Gₜ) of 1.94 mS·cm⁻², and active transport of Cl⁻ from the mucosal FW against a strong electrochemical gradient. Na⁺ movement was dominated by passive diffusion. The opercular epithelia of Fundulus adapted to 10% SW exhibited properties similar to SW Fundulus by actively extruding Cl⁻ while Na⁺ moved passively into the mucosal 10% SW. With FW bathing the mucosal surface, FW Oreochromis opercular epithelia displayed a serosal positive Vₜ of +8.0 mV, Gₜ of 1.78 mS·cm⁻², and active reabsorption of Na⁺, Cl⁻ and Ca²⁺ against large electrical and/or chemical gradients. The FW Oreochromis opercular epithelia is the only FW in vitro preparation to date that exhibits active absorption (albeit at small absolute rates) of both Na⁺ and Cl⁻. FW 0. mykiss urinary bladders mounted in vitro under symmetrical saline conditions exhibited a transepithelial conductance (Gₜ) of-9.15 mS·cm⁻² and electroneutral active absorption of Na⁺ and Cl⁻ from the mucosal urine side. The transport of Na⁺ and Cl⁻ was a partially coupled process whereby removal of Na⁺ from the mucosal saline decreased Cl⁻ absorption by a 56% and removal of Cl⁻ inhibited Na⁺ absorption by 69%. However, active net absorption of both ions persisted when the counter-ion was replaced with a non-permeant ion. Under more realistic conditions with artificial urine bathing the mucosal surface, Vₜ increased to a serosal positive ~+7.6 mV and Gₜ decreased to ~1.47 mS·cm⁻² Unidirectional influx rates of both Na⁺ and Cl⁻ were much lower, but active absorption of both ions still occurred. Replacement of Na⁺ in the mucosal artificial urine caused no change in unidirectional influx of Cl⁻ and vice versa. The mucosal addition of DIDS, amiloride or bumetanide (10⁻⁴M) all had no affect on absorption rates of Na⁺ and/or Cl⁻, under either artificial urine or symmetrical saline conditions. When the mucosal surface was bathed in artificial urine, removal of mucosal Cl⁻· significantly reduced the maximum transport rate (Jₘₐₓ of Na⁺ (6.1 ~2.1 μmol·cm⁻²·h⁻¹) but had no effect on affinity for Na⁺ (Kₘ~27 mM). Similarly, removal of mucosal Na⁺ significantly reduced the Jₘₐₓ for Cl⁻ uptake (11.4 ~2.4 μmol·cm⁻²·h⁻¹) but had no effect on Cl⁻ Kₘ(~37 mM). The anterior portion of the urinary bladder transported Na⁺ and Cl⁻ at a faster rate than the posterior portion under symmetrical saline conditions, but there was no difference in measured Na⁺/K⁺ -ATPase activities between the two portions. In conclusion, opercular epithelia of Fundulus and Oreochromis demonstrated transport properties believed to be typical of FW teleosts; either preparation may eventually prove to be a good working model for studying FW transport mechanisms. The urinary bladder of Oncorhynchus mounted in vitro did not behave characteristically as the teleost gill is thought to function, but this model may be useful in characterizing various other mechanisms of ionic transport.

abstract: Thesis

abstract: Master of Science (MSc)


title: Associative Tolerance to Repeated Heat Stress

contributor:
Siegel, Shepard
Psychology

subject: associative tolerance, repeat heat stress, temperature, thermoregulation

abstract: Learning processes have been demonstrated to play an integral role in drug tolerance. More recently, researchers have found that associative mechanisms also play an important role in the adaptation to cold exposure (Riccio, MacArdy & Kissinger, 1991). The present study investigated the effect of contextual stimuli on temperature response to repeated heat stress. Rats receiving repeated heat exposures (56°C, 10 min, 6 trials) demonstrated adaptation to the heat as measured by a decrease in hyperthermia. The tolerance to the heat stress was not disrupted by changing the contextual cues associated with the heat. These findings demonstrate tolerance to repeated heat stress but do not provide evidence of associative learning in this adaptation. Future experiments should assess the question of thermoregulation and associative processes using highly discriminant conditioning environments.

abstract: Thesis

abstract: Master of Science (MSc)


title: The Fate of Midline Lineages in the Embryos Deficient for Apoptosis in Drosophila melanogaster

title: Midline Lineages in Embryos Deficient for Apoptosis in Drosophila

subject:
apoptosis
drosophila melanogaster

abstract:
One function of programmed cell death in the developing CNS is the removal of excess cells that provide transient function. Previous studies in Drosophila observed an overpopulation of midline glia cells in embryos deficient for apoptosis. Where do these extra glia cells come from? Using different enhancer traps and antibodies as cell identity markers, the cell number of different CNS midline lineages was assessed in both wild type and Df(3L)H99 embryos which are deficient for apoptosis. The results show that at stage 16 there are approximately 3 cells labeled by midline glia specific markers (AA142 enhancer trap & P[slit1.0/lacZ] reporter construct) in wild type while there are up to 12 cells in embryos deficient for apoptosis. Comparing the number of midline neurons of mutants with that of wild type embryos, there are no detectable changes labeled by the enhancer trap P223, antibody 22C10, or an antibody to Engrailed. Exceptionally, there is one more neuron labeled by enhancer trap XS 5 in Df(3L)H99 embryos. Therefore, apoptosis is restricted to the midline glia lineage. Using P[slit1.0/lacZ] as MG marker, I observed that the extra midline glia in Df(3L)H99 initially appear at late stage 12 or early stage 13. The expression of reaper mRNA precedes programmed cell death. In wild type embryos, the initial expression of reaper mRNA of midline cells is at late stage 11 as revealed by in situ hybridization. These indicate that the first programmed cell death in the midline occurs approximately at stage 12. The supernumerary cells labeled by midline glia specific markers in Df(3L)H99 embryos share featur,es ofthe midline glia. These extra midline glia may be divided into two groups according to their differentiation. The cells of the first group strongly express the AA142 enhancer trap and ensheath the commissures. These cells are functional midline glia corresponding to the surviving midline glia in wild type embryos. The cells of the second group weakly express the AA142 and associate with but do not ensheath the commissures. These are likely the cells which normally undergo apoptosis in wild type. The results of this study indicate that the supernumerary midline glia come from neither midline glia proliferation nor other lineages. They may come from a midline glia progenitor pool in which midline glia marker expression begins at different stages. In wild type embryos, these potential midline glia die by apoptosis before activating midline glia specific genes. In Df(3L)H99 embryos, these midline glia survive and express midline glia markers.
All the midline glia die in embryos mutant for spitz group genes. In embryos double mutant for spitz group genes and Df(3L)H99, supernumerary midline glia cells survive. These cells cannot totally rescue the axon tract phenotype of spitz group gene mutants indicating that spitz group genes are necessary for producing 'mature' midline glia. In Df(3L)H99 embryos, approximately 12 midline cells labeled with the midline glia specific marker P[slit1.0/lacZ]. However, there is not a significant increase in the number of midline glia expressingpnt or argos compared with wild type. Therefore, the survival of supernumerary midline glia in embryos deficient for apoptosis does not require DER signaling. However, the DER pathway seems to specify which and how many midline glia progenitors avoid apoptosis.

abstract: Thesis

abstract: Master of Science (MSc)


title: Identification and Molecular Characterization of dveli, the drosophila ortholog of C. Elegans lin-7

contributor:
Jacobs, J. Roger
Biology

subject: Receptors, signal transduction, plasma membrane, c. elegans,

abstract:
Receptors and signal transduction complexes are assembled in a precise manner at
specific subdomains of the plasma membrane. Recent research has implicated scaffolding
proteins in organizing these receptor and signaling complexes. One well characterized
example is the C. elegans LIN-2/LIN-7 /LIN-1 0 complex. This complex is essential in the
proper localization of LET -23, the EGFR ortholog, to the basolateral membrane surface of
vulval epithelial cells.
The mammalian orthologs of the LIN-2/LIN-7 /LIN-10 complex have been
identified. CASKIVELI!Mintl/Xllalpha function as a tripartite complex in neurons,
presynaptically and postsynaptically. Presynaptically, the multi protein complex aids in
linking cell adhesion to ion influx, synaptic vesicle fusion with the presynaptic membrane.
and subsequent neurotransmitter release. At the post-synaptic membrane, the
CASKIVELI!Mintl/Xllalpha complex is hypothesized to function in the sorting and
proper localization of the NMDA type glutamate receptor, reflecting the function of the C.
elegans orthologs in receptor localization.
We have identified the Drosophila orthologs ofLIN-2/CASK, LIN-7NELI, and
LIN-10/Mintl/Xllalpha, termed CMG, dVELI and dMINT. respectively. These proteins
were found to be highly conserved among species. The Drosophila YELl protein was
initially identified by the McGlade laboratory, University of Toronto, where it was found to
bind phosphorylated Drosophila EGFR (DER). We have mapped the chromosomal
location of dveli, determined RNA transcript distribution and protein localization, and
initiated a P-element mutagenesis screen to generate a dveli mutant. Furthermore, candidate
genes for other proteins known to associate with LIN-7 (PALS) have been identified by
sequence analysis.
dVELI expression begins early in the larval stage. It is concentrated mostly in neuropil areas, sites of synaptic connections. This expression pattern continues into adult
development. Within the larval CNS, dVELI protein is localized to the neuropil areas of the
ventral nerve cord and brain. NMJ staining further localizes dVELI almost exclusively to
the post-synaptic density. This post-synaptic localization resembles that of mammalian
YELls, wherein the complex is thought to aid in glutamate receptor sorting and localization.
The similarity in structure and expression patterns of dVELI to that of its mammalian
orthologs suggests a model in which the Drosophila complex aids in the localization of
receptors to post -synaptic specializations in neurons.

abstract: Thesis

abstract: Master of Science (MSc)


title: An Analysis of Seasonal Sestonic-Mercury and the Effect of Biomanipulation on the Phytoplankton of Two Precambrian Shield Lakes

contributor:
Chow-Fraser, Patricia
Biology

subject:
biomanipulation
phytoplankton
seasonal sestonic-mercury
precambrian shield lakes

abstract: As part of the collaborative Dorset Research Project investigating mercury and energy fluxes in fresh-water lakes, I measured mercury in the seston (Chapter 1) and studied the biomanipulation impacts on the phytoplankton (Chapter 2) of two Precambrian Shield lakes. Sestonic-mercury (HgT) was measured in the metalimnion and hypolimnion of each lake throughout the summer of 1995 to determine seasonal fluctuations and the relationship with algal productivity. In each lake, sestonic-HgT (pg Hg/L) did not significantly change in the metalimnion but significantly increased in the hypolimnion by season's end. Combined influences of external HgT inputs, seston sedimentation and increased methylmercury production in the hypolimnia over the season may have contributed to these trends. In comparison to other variables measured, algal productivity was highly correlated with sestonic mercury concentrations in both lakes at each limnetic depth. Although there were no significant differences between lakes with respect to average weight-specific HgT (pg HgT/mg D.W.), chlorophyll a exhibited the best correlations with HgT in MouseL. whereas algal biomass was more highly correlated with HgT in Ranger L. This disparity between lakes may be the result of apparent inter-lake differences in light availability and algal community structure. It was also apparent that changes in the proportions of large and small cells over the season affected the magnitude of sestonic mercury measured. With respect to the potential for trophic transfer of mercury, I suggest that small edible algal cells may bioconcentrate more mercury per unit weight than larger, inedible ones. The data also indicate that seston samples should be collected throughout the season at discrete depths if sestonic-mercury measurements are to be used in trophic transfer models. I also examined the effects of fish biomanipulation on the phytoplankton community of these study lakes. Prior to the biomanipulation, Ranger L. had a top-piscivore community whereas Mouse L. had a top-planktivore community. The biomanipulation involved the removal of top-piscivores from Ranger L. and adding top-piscivores to Mouse L. Trophic Cascade theory predicts that algal biomass in these lakes, with their similar morphometries and resource characteristics, should be ultimately controlled by top-consumer abundance. In addition, model predictions expect "edible" algal size-classes and groups in the community to experience the greatest changes in abundance. Therefore in Ranger L., it was expected that the removal of piscivores would result in higher algal biomass (particularly edible algae), whereas the addition of piscivores in Mouse L. would result in lower algal biomass (particularly edible algae). However, for those years following the biomanipulation, algal biomass significant increased in both lakes compared to pre-manipulation years. This suggests that variables other than direct trophic forces were controlling algal biomass from year to year, regardless of changes in the fish communities. When algal size-classes were tested, only edible cells varying from 10-30 μm increased in Mouse L., contrary to what was predicted. In Ranger L., large cells and colonies > 30 μm unexpectedly increased when all other size-classes did not significantly change. With respect to algal group composition, both Greens and Cryptomonads significantly increased in Mouse L. whereas only Greens significantly increased in Ranger L.. Both of these groups were considered to be edible and thus these results were not consistent with the model predictions. As such, I suggested that "bottom-up" influences were important in controlling both size-class and taxonomic abundances. However, when individual size-classes of representative algal genera were compared between pre-and post-manipulation years, there were some effects which may be attributed to the biomanipulation. In particular, large Green colonies became prevalent in Mouse L. during post-manipulation years as a probable response to increased grazing pressure. Conversely, "edible" Greens became prevalent in Ranger L. after the biomanipulation, supporting the prediction of reduced zooplankton grazing pressure. These results have revealed the necessity to test specific algal genera of varying size-classes in order to detect the effects of biomanipulation. They also showed that the majority of algal genera, regardless of size, were not affected by the biomanipulation. Limitations to my interpretation of the data are discussed and vary from time-scale issues to consumer and resource availability unknowns. Along with recommendations for further studies in this area, I hypothesized that the trophic transfer of sestonic-mercury to zooplankton could be intensified if small, edible algal genera (shown to be impacted by Top-Down forces), have relatively higher weight-specific mercury concentrations. However, considering that the phytoplankton community as a whole has shown resilience to herbivory, I also suggest that the majority of mercury measured in the seston is not available for trophic transfer to zooplankton consumers.

abstract: Thesis

abstract: Master of Science (MSc)


title: Inhibition of Gastric Emptying is Neither Necessary nor Sufficient for Peptide-Induced Satiety in the Rat

title: Relationship Between Gastric Emptying and CCK-8 Induced Satiety

contributor:
Weingarten, H.
Psychology

subject:
gastric emptying
rat
peptide-induced satiety
cck--8

abstract: This research examines the hypothesis that the satiety effect of cholecystokinin octapeptide (CCK-8) is mediated by changes in gastric emptying. A method for collection of gastric emptying data, the double sampling procedure, is developed and validated for use in the rat. The double sampling technique permits repeated measurements of liquid gastric volume and thus describes the time course of emptying within a single experimental session. Further, the method allows determination of the amount of gastric secretion, volume emptied into the intestines, and amount of gastric load remaining in the stomach. Experiments are presented which: i) demonstrate the utility of the technique; ii) validate its accuracy in determining gastric volume; iii) indicate the stability of measurements obtained with this procedure; and iv) provide a procedure for quantitative evaluation of data obtained with this technique. Using the double sampling procedure, the ability of CCK-8 to delay gastric emptying and to influence feeding are then compared under similar experimental conditions. The effect of CCK-8 on gastric emptying is assessed in 6 hr deprived rats receiving 10 ml intragastric test loads of either .15M saline or 15% sucrose. Intraperitoneal (ip) injections of CCK-8 in doses of 1.4-22.4 ug/kg produce a dose-dependent retardation of gastric emptying of both saline and nutrient. Lower doses of CCK-8, 0.01 and 0.1 ug/kg, have no effect on gastric emptying. The effect of CCK-8 on feeding is assessed in rats tested under the same experimental conditions used in the gastric emptying studies. Doses of CCK-8 capable of retarding gastric emptying also suppress eating in a dose-dependent manner. These findings provide necessary correlational support for the hypothesis that satiety produced by CCK-8 is mediated by inhibition of gastric emptying. However, a further quantitative analysis of the correspondence of the gastric emptying and feeding effects of CCK-8 suggest that retardation of emptying may not account for the entire satiety effect of the peptide. The next set of studies provide direct tests of whether changes in gastric emptying mediate CCK-induced satiety. If gastric emptying plays a significant role in the satiety produced by CCK-8 then: i) the effects of CCK-8 on emptying and feeding should share similar kinetics, and ii) peptides that inhibit emptying should also inhibit feeding. I show that CCK-8 (5.6 ug/kg) injected coincident with introduction of an intragastric load or presentation of a test meal produces a rapid inhibition of both emptying and feeding. In contrast, the identical dose of CCK-8 administered 15 min before testing causes no inhibition of emptying, even though the peptide retains its ability to produce satiety. I also test the abilities of the peptides pentagastrin (100 ug/kg), bombesin (8 & 16 ug/kg) and secretin (2.86, 14.3 & 28.6 ug/kg) to reduce food intake and inhibit gastric emptying. Pentagastrin does not affect food intake or gastric emptying. Bombesin causes a small transient delay in emptying but a large and sustained suppression of eating. High dose secretin (14.3 ug/kg) causes no significant reduction of food intake, even though this dose of secretin inhibits emptying to the same degree as 1.4 ug/kg CCK-8, which does reduce intake. Thus, although CCK-8 does influence the rate of gastric emptying, the present results indicate that the inhibition of emptying by CCK is neither necessary nor sufficient to explain its satiety effect.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Population Genetic Structure and Phylogeography of Yellow Warblers (Dendroica petechia) Inferred from Mitochondrial DNA Sequence Data

title: Yellow Warbler Population Genetics

contributor:
Gibbs, H.
Biology

subject:
yellow warblers
mitochondrial DNA
population genes

abstract: The Yellow Warbler (Dendroica petechia) is a highly polytypic bird species with a vast breeding range in the Americas. To assess the level of population structuring within the northern part of its range, I surveyed the nucleotide variation present in a 344bp segment of the mitochondrial DNA (mtDNA) control region I (CR-I) from 155 breeding individuals. These birds were caught at seven locations in Canada and Alaska. Fifty-nine haplotypes were observed in this sample, with pairwise distances between haplotypes ranging from 0.29 to 4.35%. The number of nucleotide sites with multiple hits indicates a high rate of evolution in this region. A homologue to the CR-I was also identified and likely originated from a paralogous duplication event, as suggested by the comparison of sequences from the two regions. Significant population structuring in Yellow Warblers across North America was revealed by analyses of nucleotide diversity and molecular variance, which demonstrated the existence of a major subdivision between eastern (Manitoba to Newfoundland) and western (Alaska and British Columbia) warbler populations. This finding provides evidence for very low levels of gene flow between these two groups. Fifteen out of 21 pairs of populations differ significantly in their genetic composition, indicating further structuring at a smaller geographic scale. Within the eastern group of populations, both the high mutation rate of the CR-1 and an isolation-by-distance process seem to be responsible for differences between locations. Phylogenetic analyses indicate that western birds form a monophyletic group whereas eastern birds are paraphyletic with respect to the western ones. However this conclusion remains hypothetical because of a lack of statistical support for the monophyly of western haplotypes. Nevertheless, this situation is consistent with a historical splitting of warbler populations by a vicariant event, possibly of Pleistocene origin, and provides intraspecific support for vicariance as a mechanism leading to isolation and speciation of western warbler taxa, as hypothesized by Mengel (1964). However, other scenarios, such as a founder event in the west from an eastern stock, cannot be excluded, although they are less likely based on mtDNA data. The absence of phylogeographic structure in the East suggests a recent expansion of Yellow Warbler populations from a restricted geographic range. These findings demonstrate that populations of continentally distributed North American passerine species can show high level of population structuring when assayed with an hypervariable molecular marker such as the mtDNA control region I.

abstract: Thesis

abstract: Master of Science (MSc)


title: LYNDON FACTORS AND PERIODICITIES IN STRINGS

contributor:
Franek, Frantisek
Computing and Software

subject: Lyndon

abstract:
Strings are very simple yet very applicable data structures. Their applicability ranges from modelling DNA, to modelling protein sequences, to information retrieval, to web page searches, and many more. Due to their simplicity, there are few structural properties that could be exploited for analysis of string algorithms and their auxiliary data structures. Thus, from the beginning, researchers paid utmost attention to periodic properties of strings, such as runs which are maximal fractional periodicities.Though first conjectured in 1999 by Kolpakov and Kucherov, the runs conjecture that there are fewer runs than the length of the string was only settled in 2015 by Bannai et al. via specific Lyndon roots referred to as L-roots. This method allows mapping of runs to the starting points of its L-roots that form mutually disjoint subsets of the indices of the string. This relationship between runs and maximal Lyndon factors (substrings) of a string is not coincidental, as Bannai et al. used the
knowledge of all maximal Lyndon  factors with respect to an order and its inverse to compute all runs in linear time.  Thus, computing the  all maximal Lyndon factors efficiently becomes of importance.

In this thesis, we review the fundamental properties of Lyndon strings,including the famous Lyndon factorization and its linear solution due to Duval. In addition to that we explore a new and conceptually simple data structure called Lyndon array and its relationship to the suffix array.
Finally, we discuss 2015 Baier's algorithm for sorting suffixes that identifies and sorts in phase 2 the maximal Lyndon factors in O(log ∑)steps for a string of length n over an alphabet ∑. We examine the fact that Baier's algorithm sorts the suffixes by sorting the maximal Lyndon factors, and present a different, potentially faster algorithm for phase 2. Our goal was to gather all the relevant well known and some unpublished facts about Lyndon strings and
their relationship to runs. In addition we present a novel  O(n log(n)) recursive algorithm for computing Lyndon arrays that may be competitive with Baier's for strings with large alphabets.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: THE FEASIBILITY OF MECHANISTIC STUDIES ON THE ROLE OF IMMUNITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS

contributor:
Samaan, Constantine
Medical Sciences

abstract:
Background: The most prominent form of spinal curvature in youth (scoliosis) is Adolescent
Idiopathic Scoliosis (AIS). While AIS aetiology is unclear, the role of paraspinal muscle in its
genesis has been debated, as These muscles provide spinal stability and motion. It is known that
paraspinal muscle (PM) exhibits differential fibrosis on both sides of the spine. As fibrosis is the
result of immune system activation, we sought to elucidate the upstream mechanisms of
immune-muscle interactions in AIS.
Objectives: The primary objective of this thesis was to determine the feasibility of a
translational research study (Immunometabolic CONnections to Scoliosis (ICONS) study)
procedures. Secondary objectives include the performance of exploratory analyses of
macrophages in PM of AIS patients on both sides of the spine. As adiposity is associated with
muscle inflammation in the general population, the association of whole-body adiposity with PM
macrophage content and/or phenotype was investigated.
Hypothesis: We tested the hypothesis that ICONS study protocols are feasible and that PM
macrophage populations are different on both sides of the spine. Furthermore, we hypothesized
that increasing adiposity positively correlates with PM macrophage infiltration.
Results: We observed that all pre-set feasibility criteria were achieved or surpassed, except that
of recruitment rate. PM total macrophage content was not different on either side of the scoliotic
curve; however, a trend of predominance of anti-inflammatory macrophages on the convex side
of the scoliotic curve was noted. PM macrophage content correlated positively with adiposity.
Conclusions: Adopting the ICONS study procedures for the full study is feasible. Continued
investigations of immune system role in PM of AIS patients may identify therapeutic targets to
aid AIS treatment and prevention.

abstract: Thesis

abstract: Master of Science (MSc)


title: An Investigation of Menstrual Cycle Effects on the perception of facial attractiveness

contributor:
deCatanzaro, Denys
Psychology

subject: evolutionary psychology, hormonal fluctuations,

abstract:
The present study, performed within the framework of evolutionary
psychology, is an examination of the influence of hormonal fluctuations,
associated with the phases of the menstrual cycle, on judgements of male and
female facial attractiveness. It was hypothesized that women in the periovulatory
phase would be more discriminating in rating male facial
attractiveness than women in the early follicular phase, due to an increased
likelihood of conceiving. Alternatively, if peri-ovulatory women are too
selective, they may not fmd a mate; therefore, women in the peri-ovulatory
phase could be more discriminating than women in the early-follicular phase.
Judgements of female facial attractiveness were also examined as it may be
associated with same sex competition. Lastly, salivary testosterone was
analyzed in order to investigate the relationship between attractiveness ratings
and testosterone levels, as testosterone is linked to women's libido and
sexuality. To test these hypotheses, 129 undergraduate females who had
regular and normally cycling menstrual cycles rated male and female facial
attractiveness twice, once during the peri-ovulatory phase and again during
the early-follicular phase. Menstrual phase had no significant influence on
judgements of facial attractiveness of male and female faces. Female faces were rated as more attractive than male faces independent of phase, and the
ratings were more variable for the female faces than the male faces. There
was no difference in levels of salivary testosterone during the peri-ovulatory
and the early follicular phase, and no significant correlations were obtained to
support the hypothesis of a relationship between judgements of attractiveness
and testosterone.

abstract: Thesis

abstract: Master of Science (MSc)


title: Echo Planar Magnetic Resonance Imaging of Skeletal Muscle Following Exercise

contributor:
Noseworthy, Michael
Medical Physics

subject:
skeletal muscle
magnetic resonance imaging
MRI
echo planar imaging
BOLD
exercise
motion correction
distortion correction
independent component analysis
image processing

abstract:
In recent years, researchers have increasingly used magnetic resonance imaging (MRI) to study temporal skeletal muscle changes using gradient echo (GRE) echo planar imaging (EPI). These studies, typically involving exercise or ischemic challenges, have differentiated healthy subjects from athletic or unhealthy populations, such as those with peripheral vascular disease. However, the analysis methodologies have been lacking.

In this thesis, two sessions of post-exercise GRE EPI data were collected from six subjects' lower legs using a 3 Tesla MRI scanner and a custom built ergometer. Past studies used common medical imaging software for motion correction. This work shows that such tools degrade leg image data by introducing motion, increasing root mean squared error in rest data by 22%. A new approach decreased it by 12%. EPI distortion correction in muscle images was also achieved, with the correlation ratio of functional and structural images increasing by up to 8%.

In addition, a brief but intense artifact in GRE EPI muscle images results from muscle tissue moving in and out of the imaged volume. This through-plane artifact was successfully modelled as a mono-exponential decay for regression analysis, increasing the utility of the residual signal. The regression parameters were also leveraged to produce muscle displacement maps, identifying 44% of voxels as displaced. The maps were validated in a motion phantom and in-vivo using ultrasound.

Finally, independent component analysis (ICA) was applied to post-exercise GRE EPI images to detect features in a data-driven, multivariate way and improve on conventional ROI selection methods. ICA produced parametric maps that were spatially correlated to working muscles from every trial (most with |R| > 0.4). The components were also separated from the susceptibility, motion, and blood vessel signals, and temporally reliable within individuals.

These methodological advances represent increased rigour in the analysis of muscle GRE EPI images.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract:
Adequate blood circulation to muscles is important for good health. Researchers have used magnetic resonance imaging (MRI) techniques to assess blood and oxygen supply to muscles. The work in this thesis improves upon the analysis methods in prior work, especially in the areas of motion correction of the images and selection of individual muscle regions for analysis.

Previous techniques could sometimes make motion in muscle images worse. This work provides valuable motion and distortion correction for muscle imaging, ensuring that measurements truly reflect muscle physiology. It also describes a method to remove an unwanted signal from post-exercise muscle data, and create a map of the internal muscle motion that occurred.

Finally, an advanced mathematical technique was used to extract signals of interest and important spatial features from muscle image data automatically. The technique produced reliable results within and among subjects.


title: Molecular Genetic Analysis of the Mating system and host choice of an obligate brood parasitic bird, the brown-headed cowbird (molothrus ater)

subject: avian mating systems, parasitic birds

abstract:
Parasitism can be defined as a biological interaction in which one party benefits at
the expense of another (Keeton and Gould 1986). However unlike predation, the parasite
does not kill its host. In the case of avian brood parasitism, one bird lays its eggs in the
nest of a member of its own or another species and then abandons its offspring to the care
of its new foster parents. These foster parents or 'hosts' then raise the parasitic young at
the expense of their own brood. Brood parasitic birds have reproductive advantages over
those which provide parental care for their young because: 1) parental care provided by
several fosterers allows a female to produce more successful offspring than she is capable
of rearing herself in one season, and 2) parasite offspring are usually distributed among
many host nests thereby increasing the probability that at least some offspring will escape
predation (Payne 1977).
Obligate interspecific brood parasitism, where females only parasitize the nests of
other species, is a reproductive strategy adopted by approximately 1% of all bird species
and is practiced by members of five families (Anatidae, Cuculidae, Indicatoridae, Icteridae,
and Ploceidae). The degree to which interspecific brood parasites reduce host nesting
success varies with the reproductive tactics of the parasite. For example, Common
Cuckoo chicks (Cuculus canorus) eject eggs and young nest mates from the host nest with
the help of an instinctive urge to push out of the nest anything that touches the sensitive shallow depression in the parasitic nestling's back (Lack 1968). Young African Greater
Honey-guides (Indicator indicator) stab host nestlings to death with special mandibular
hooks that drop off after two weeks of age (Friedmann 1955). In contrast, black-headed
duck hatchlings seek only protection and warmth for 1-2 days post hatching and then
leave the nest with no further cost to their host (Weller 1968). Finally, Brown-headed
Cowbird nestlings intermediately affect host reproductive success by diverting parental
resources such as food away from the host's young (Payne 1977). This loss of host fitness
results in selective pressure for host defenses against parasitism such as egg ejection
(Neudorf and Sealy 1992), clutch abandonment (Burgham and Picman 1989), or increased
nest defense early in the nesting cycle (Burgham and Picman 1989, Briskie and Sealy
1989, Neudorfand Sealy 1992). To circumvent these host responses, adaptation in brood
parasites has resulted in selective pressure for egg mimicry (Rothstein 1990), egg removal,
or shorter incubation periods (Briskie and Sealy 1990, Payne 1977).
The Brown-headed Cowbird is the most abundant and widely distributed obligate
interspecific brood parasite in North America. Although the breeding behaviour of this
bird has been widely studied, most findings are contradictory. The mating system of the
Brown-headed cowbird has been described as ranging from monogamous (Laskey 1950,
Dufty 1982a, 1982b, Yokel 1986), to promiscuous (Elliot 1980). Most studies also
suggest that cowbirds parasitize multiple host species (Friedmann 1929, p 177-188, Jones
1941, McGeen & McGeen 1968, Elliot 1977, Fleischer 1985). However, a few suggest
that some individuals may be host specialists (Walkinshaw 1949, McGeen & McGeen 1968). Few of these studies have used genetic techniques to determine the actual mating
patterns and to investigate the breeding biology of males and females in a single marked
population. The main objective of this study was to use molecular genetic DNA markers
as well as behavioural observation to study the mating system and host specificity of a
Brown-headed Cowbird population at Delta Marsh, Manitoba. More specifically, my
objectives were to: 1) determine whether DNA microsatellite markers are useful for
determining parentage in Brown-headed Cowbird populations 2) document the genetic
mating system and the patterns of host use by individual females in a population of
resident cowbirds.
My findings provide the first evidence that microsatellites are useful for high
resolution parentage analyses in brood parasitic bird species where there is no A priori
information available on male or female parentage. In addition, they are the first to
directly quantity the mating system of a Brown-headed Cowbird population and to
suggest that individual females are best described as host generalists but may be showing
some preference for host nests in one habitat over another.

abstract: Thesis

abstract: Master of Science (MSc)


title: L’OBJET DU DÉSIR ET LE DEVENIR ÉCRIVAIN DANS «À LA RECHERCHE DU TEMPS PERDU» de Marcel Proust

contributor:
Moyal, Gabriel
French

subject: Desirs, art, androgynie, objets

abstract:
The thesis explores Marcel Proust’s À la Recherche du Temps Perdu and examines the narrator’s artistic and androgynous processes of becoming a writer and analyses how the combination of these two processes of “becoming” (artistic and androgynous) transforms the narrator into a writer.  To examine these topics phenomenology was used as a meth-odological approach.  Phenomenology is a method of inquiry that attempts to describe experiences as they are perceived and interpreted by human consciousness, as opposed to scientific description.  The review of the critical literature provides a summary of various critics whose works have contributed to this thesis; it focuses on both Maurice Merleau-Ponty's and Sara Ahmed’s writings on the phenomenological perspectives, that serve to set up the predominant theoretical framework.

	The first chapter presents both the critical and theoretical concepts pertinent to this thesis.  The second chapter describes the theoretical framework concentrating on phenomenology, and grants more attention to both Merleau-Ponty’s and Sara Ahmed’s theories.  The third chapter analyses the narrator’s artistic evolution and his process of “becoming” a writer; his descriptions of experiences and associated sensations towards people and objects.  Artistic works are preponderant in la Recherche where the three es-sential media: vision, sound, and prose are represented by: Elstir’s picture, Vinteuil’s Sep-tuor, and Bergotte and the narrator respectively.  The fourth chapter examines the an-drogynous aspects of la Recherche in addition to the evolution of the narrator’s sexual identity; it evidences how his artistic evolution and his androgynous consciousness com-
vii
bined concurrently to transform the narrator in to "becoming" a writer.  The fifth chapter analyzes Proust’s aesthetic conception and his eclecticism.  Analogies to Nietzsche, Wag-ner, and Leibnitz are discussed.  The thesis concludes with Proust’s precept that art, through intellect and sensations, provides a path towards spiritual life.  The thesis aims to making Proust’s work more accessible, and enabling readers to thereby become more aware of their surroundings, and providing them with new perspectives on life.

The thesis explores Marcel Proust’s À la Recherche du Temps Perdu and examines the narrator’s artistic and androgynous processes of becoming a writer and analyses how the combination of these two processes of “becoming” (artistic and androgynous) transforms the narrator into a writer.  To examine these topics phenomenology was used as a meth-odological approach.  Phenomenology is a method of inquiry that attempts to describe experiences as they are perceived and interpreted by human consciousness, as opposed to scientific description.  The review of the critical literature provides a summary of various critics whose works have contributed to this thesis; it focuses on both Maurice Merleau-Ponty's and Sara Ahmed’s writings on the phenomenological perspectives, that serve to set up the predominant theoretical framework.

	The first chapter presents both the critical and theoretical concepts pertinent to this thesis.  The second chapter describes the theoretical framework concentrating on phenomenology, and grants more attention to both Merleau-Ponty’s and Sara Ahmed’s theories.  The third chapter analyses the narrator’s artistic evolution and his process of “becoming” a writer; his descriptions of experiences and associated sensations towards people and objects.  Artistic works are preponderant in la Recherche where the three es-sential media: vision, sound, and prose are represented by: Elstir’s picture, Vinteuil’s Sep-tuor, and Bergotte and the narrator respectively.  The fourth chapter examines the an-drogynous aspects of la Recherche in addition to the evolution of the narrator’s sexual identity; it evidences how his artistic evolution and his androgynous consciousness com-
vii
bined concurrently to transform the narrator in to "becoming" a writer.  The fifth chapter analyzes Proust’s aesthetic conception and his eclecticism.  Analogies to Nietzsche, Wag-ner, and Leibnitz are discussed.  The thesis concludes with Proust’s precept that art, through intellect and sensations, provides a path towards spiritual life.  The thesis aims to making Proust’s work more accessible, and enabling readers to thereby become more aware of their surroundings, and providing them with new perspectives on life.

The thesis explores Marcel Proust’s À la Recherche du Temps Perdu and examines the narrator’s artistic and androgynous processes of becoming a writer and analyses how the combination of these two processes of “becoming” (artistic and androgynous) transforms the narrator into a writer.  To examine these topics phenomenology was used as a meth-odological approach.  Phenomenology is a method of inquiry that attempts to describe experiences as they are perceived and interpreted by human consciousness, as opposed to scientific description.  The review of the critical literature provides a summary of various critics whose works have contributed to this thesis; it focuses on both Maurice Merleau-Ponty's and Sara Ahmed’s writings on the phenomenological perspectives, that serve to set up the predominant theoretical framework.

	The first chapter presents both the critical and theoretical concepts pertinent to this thesis.  The second chapter describes the theoretical framework concentrating on phenomenology, and grants more attention to both Merleau-Ponty’s and Sara Ahmed’s theories.  The third chapter analyses the narrator’s artistic evolution and his process of “becoming” a writer; his descriptions of experiences and associated sensations towards people and objects.  Artistic works are preponderant in la Recherche where the three es-sential media: vision, sound, and prose are represented by: Elstir’s picture, Vinteuil’s Sep-tuor, and Bergotte and the narrator respectively.  The fourth chapter examines the an-drogynous aspects of la Recherche in addition to the evolution of the narrator’s sexual identity; it evidences how his artistic evolution and his androgynous consciousness com-
vii
bined concurrently to transform the narrator in to "becoming" a writer.  The fifth chapter analyzes Proust’s aesthetic conception and his eclecticism.  Analogies to Nietzsche, Wag-ner, and Leibnitz are discussed.  The thesis concludes with Proust’s precept that art, through intellect and sensations, provides a path towards spiritual life.  The thesis aims to making Proust’s work more accessible, and enabling readers to thereby become more aware of their surroundings, and providing them with new perspectives on life.

The thesis explores Marcel Proust’s À la Recherche du Temps Perdu and examines the narrator’s artistic and androgynous processes of becoming a writer and analyses how the combination of these two processes of “becoming” (artistic and androgynous) transforms the narrator into a writer.  To examine these topics phenomenology was used as a meth-odological approach.  Phenomenology is a method of inquiry that attempts to describe experiences as they are perceived and interpreted by human consciousness, as opposed to scientific description.  The review of the critical literature provides a summary of various critics whose works have contributed to this thesis; it focuses on both Maurice Merleau-Ponty's and Sara Ahmed’s writings on the phenomenological perspectives, that serve to set up the predominant theoretical framework. The first chapter presents both the critical and theoretical concepts pertinent to this thesis.  The second chapter describes the theoretical framework concentrating on phenomenology, and grants more attention to both Merleau-Ponty’s and Sara Ahmed’s theories.  The third chapter analyses the narrator’s artistic evolution and his process of “becoming” a writer; his descriptions of experiences and associated sensations towards people and objects.  Artistic works are preponderant in la Recherche where the three essential media: vision, sound, and prose are represented by: Elstir’s picture, Vinteuil’s Septuor, and Bergotte and the narrator respectively.  The fourth chapter examines the androgynous aspects of la Recherche in addition to the evolution of the narrator’s sexual identity; it evidences how his artistic evolution and his androgynous consciousness combined concurrently to transform the narrator in to "becoming" a writer.  The fifth chapter analyzes Proust’s aesthetic conception and his eclecticism.  Analogies to Nietzsche, Wagner, and Leibniz are discussed.  The thesis concludes with Proust’s precept that art, through intellect and sensations, provides a path towards spiritual life.  The thesis aims to making Proust’s work more accessible, and enabling readers to thereby become more aware of their surroundings, and providing them with new perspectives on life.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: The thesis explores Marcel Proust’s À la Recherche du Temps perdu and examines the narrator’s artistic evolution of becoming a writer through his descriptions of his experiences and associated sensations.  The thesis is divided into three sections: the first focuses on the narrator’s artistic life, the second is dedicated to his sexual identity, and evidence how they concurrently transform the narrator into becoming a writer.  The third section explores Proust’s aesthetics and his conception that art provides a path towards a spiritual life.  The thesis aims to render Proust’s work more accessible, thereby enabling others to be more sensitive to their surroundings, and provide new perspectives on life.  Research was conducted through McMaster University Library and the internet.