title: Effects of Site Directed Mutagenesis of the Second Exon of the Adenovirus 5 E1A Gene on Transcriptional Activation

title: Mutagenesis of the Second Exon of the AD5 E1A Gene

contributor:
Bayley, Stanley
Biology

subject:
mutagenesis
exon
AD5
adenovirus 5
transciption
activate
gene

abstract: The early region 1a oncogene of adenovirus 5 codes for proteins that can activate transcription of viral and cellular genes. This study describes the construction of three deletions and one point mutation that together span the entire coding region of the second exon of E1A. The exon-2 mutants were tested for their ability to activate transcription from the adenovirus early region 3 promoter (E3) in transient expression assays. Dl1116 (dl aa 205-221) did not affect transactivation of E3 in pKCAT-23. Sub1117 (dl exon-2 aa) and dl1115 (dl aa 188-204) were unable to activate transcription. Pm1131 (SER-219 to stop) had a reduced transactivating efficiency but was still able to stimulate transcription. These results define the 3' boundary of a transactivation domain on the E1A proteins as being between positions 188 and 204. Results obtained in our lab define the 5' boundary as being between 138-147 (Jelsma et al., 1988). The mutants that could not transactivate were tested for their ability to block wildtype E1A transactivation of the E3 promoter in assays similar to those described by Glenn and Ricciardi (1987). Dl1115 and sub1117 appeared to block transactivation by WT E1A. In transient expression assays, the fatty acid sodium butyrate was found to stimulate transcription of the CAT gene, when added to the medium of HeLa cells transfected with pKCAT-23. This suggests that sodium butyrate is transactivating the Ad 5 E3 promoter.

abstract: Thesis

abstract: Master of Science (MS)


title: Mineral Nutrition in White Spruce (Picea glauca) Seeds and Somatic Embryos

title: Mineral Nutrition in White Spruce Seeds and Somatic Embryos

contributor:
Lott, J. N. A.
Biology

subject: mineral spruce embryo seed

abstract: The mineral nutrient storage reserves in various parts of white spruce (Picea glauca) seeds and somatic embryos were investigated. Somatic embryos are produced in tissue culture from single cells or small groups of cells. These cells are induced to produce a callus, which is then stimulated to produce mature somatic embryos that are desiccated down to moisture content levels comparable to those of a mature dry seed. Morphological comparisons revealed that somatic and zygotic embryos are very similar. Somatic embryos of white spruce; however, were larger, had a flared arrangement of cotyledons, had more prominent suspensor regions, had intercellular spaces in the ground meristem tissue and had ground meristem cells that had divided in several planes of division. Using a wet ashing protocol, anion exchange resins and the molybdenum blue colourimetric reaction, the total levels of P and the amount of P bound to phytic acid were measured. Phytic acid (or phytate) is the major nutrient storage compound in seeds. Although differences were found on a dry weight basis, a single somatic and a single zygotic embryo had similar levels of P. Somatic embryos produced in different batches varied in their levels of phytic acid, but a somatic embryo could have similar levels of phytic acid as a zygotic embryo. The large female gametophyte contained 86% of the total P and 95% of the total phytic acid in a single seed. Electron microscopy and energy dispersive x-ray analysis found phytate-rich globoids in the procambium and ground meristem tissues of both types of embryos. Globoids contained high P, moderate K and Mg, and little if any Ca, Fe and Zn. Globoids were generally larger and more frequent in zygotic embryos. Globoids from the cotyledon procambium of zygotic embryos also contained moderate levels of Fe. Iron-rich particles (possible Fe-phytate deposits) were found in the protoderm, procambium and ground meristem of both types of embryos. These deposits contained high P and Fe, moderate K and Mg, and little if any Ca and Zn. Globoid and Fe-rich particle compositions were similar in both embryo types, but significantly higher Fe:P ratios were found in zygotic embryos. Atomic absorption spectroscopy was used to measure total K, Mg, Ca, Fe and Zn levels. Although differences were found on a dry weight basis, a single white spruce somatic or zygotic embryo contained similar levels of all these elements. The female gametophyte contained high levels of these elements and the seed coat contained considerable Ca. Potassium leakage during imbibition in germination medium revealed that a single somatic and zygotic embryo of white spruce leaked similar levels of K. Pretreatment of somatic embryos in a high relative humidity environment resulted in decreased potassium leakage by 80 and 120 min. of imbibition. The seed coat was found to reduce the amounts of K leaked. Surface cells in dry somatic and zygotic embryos were found to be wrinkled, but cells in zygotic embryos were more shrunken in appearance. During imbibition, cells became more turgid; but after 120 min. of imbibition, surface cells still showed signs of wrinkling. To date, this is the first major report of mineral nutrition in white spruce seeds and is the first comprehensive comparison of mineral nutrients in white spruce seeds and somatic embryos. These results may be useful in producing complete artificial white spruce seeds.

abstract: Thesis

abstract: Master of Science (MS)


title: Variation of Copper and Cadmium in Pelagic Plankton of Hamilton Harbour

title: Variation of Cu and Cd in Plankton of Hamilton Harbour

contributor:
Kolasa, Jurek
Biology

subject: plankton harbour copper cadmium

abstract: Temporal variation in the levels of Cu and Cd in zooplankton, phytoplankton and water taken from five pelagic stations in Hamilton Harbour during three separate sampling periods (June, August and October/November 1990) was examined. Significant seasonal variation occurred in the Cu and Cd levels measured in water and phytoplankton (Cu Water: df=2, F=32.28, P≤.0001, Cu Phytoplankton: df=2, F=48.94, P≤.0001 and Cd Water: df=2, F=18.98, P≤.0001, Cd Phytoplankton: df=2, F=58.81, P≤.0001). However, the Cu levels observed in zooplankton did not vary significantly with season (df=2, F=1.79, P≤.1919). The maximal levels of Cd in zooplankton in November may be due to increased ingestion of material that is resuspended during turnover. Similarly, the peak levels of Cu and Cd recorded in November in phytoplankton may be due to a combination of processes: a) change in the size structure of the phytoplankton community to smaller individuals with higher metal sorption capacities and/or b) contamination of phytoplanktonic tissue samples by resuspended material. Phytoplankton metal levels (Cu and Cd) are negatively correlated with chl a concentrations (n=45, r=.8171, ≤.0001 and n-41, r=-.5961, P≤. 0001, respectively). These relationships are likely the result of a dilution effect. Zooplankton Cd levels were positively correlated with water and phytoplankton Cd concentrations (n=41, r=.3211, P≤.0407 and r=.7667, P≤.0001) while Cu levels were not correlated with any of the variables tested. The difference between the correlatedness of Cd levels in zooplankton to water and phytoplankton Cd levels compared to the lack of this type of relationship with regard to Cu may be attributable to the biological function of each metal in zooplankton. Cu is required in small amounts for physiological processes and may be regulated whereas Cd has no known biological function.

abstract: Thesis

abstract: Master of Science (MS)


title: Silver Accumulation, Physiology and Toxicity in the Freshwater Rainbow Trout: Implications for the Silver Biotic Ligand Model

title: Silver Accumulation, Physiology and Toxicity in Trout

contributor:
Wood, C. M.
Biology

subject: trout physiology silver toxic

abstract: The underlying problems associated with the development of the biotic ligand model (BLM) for prediction of silver toxicity, and its associated physiological and toxicological endpoints, were investigated at a mechanistic, physiological level in juvenile rainbow trout. An equilibrium level of silver accumulation at the gills is achieved over time during flow-through exposures. The pattern of peak and decline in accumulation during static exposures is due to a decrease in the bioavailability of Ag⁺ because of complexation by organic carbon produced by the fish, a consequence of the use of a static exposure system. The decrease in bioavailability leads to a decline in apical silver uptake and together with constant basolateral silver export, a peak and decline in gill silver accumulation. Inhibition of carbonic anhydrase (CA) by silver is responsible for the early decline in active Na⁺ uptake at the gills during flow-through silver exposure, while Na⁺K⁺-ATPase inhibition is associated with the later decline in uptake. CA activity is inhibited early during silver exposure when Na⁺ and Cl⁻ uptake are decreasing but Na⁺ K⁺ ATPase activity is not inhibited until later. The implication of the data that the rate limiting step in the movement of Na⁺ and Cl⁻ across the gill epithelium is the movement across the apical membrane, as well as the identical time course and degree of Cl⁻ and Na⁺ uptake inhibition provide additional evidence for a role of CA inhibition in the early decline in Na⁺ uptake. A relationship exists between short-term gill silver accumulation and inhibition of Na⁺ uptake. There is also a relationship between silver accumulation on the gills after 3 h, as well as after 24 h, and 96 h mortality. Together, the results of this thesis indicate that short-term gill silver accumulation is an appropriate endpoint for the prediction of acute silver toxicity in freshwater fish, lending support to the current toxicological version of the silver BLM. These results also indicate that the predictive capabilities of the current physiological BLM may be improved by using Na⁺ uptake inhibition rather than Na⁺K⁺-ATPase inhibition as an endpoint to predict acute silver toxicity.

abstract: Thesis

abstract: Master of Science (MS)


title: X-Ray Crystallographic Studies of Glycerol-3-Phosphate Cytidylyltransferase from Staphylococcus Aureus

title: The Structure of Glycerol-3-Phosphate Cytidylyltransferase from Staphylococcus Aureus

contributor:
Berghuis, A. M.
Biochemistry

subject:
crystallograph
x-ray
Cytidylyltransferase
staphylococcus aureus
staphylococcus

abstract: Glycerol-3-phosphate cytidylyltransferase from 𝘚𝘵𝘢𝘱𝘩𝘺𝘭𝘰𝘤𝘰𝘤𝘤𝘶𝘴 𝘢𝘶𝘳𝘦𝘶𝘴 complexed with CTP (TarDₛₐ-CTP) was crystallized by the hanging drop-vapor diffusion method at 22°C. Determination of crystallization condition included examination of the amount of precipitant, investigation of the effects of small molecules, and alteration of the rate of diffusion. With these three optimization steps, crystals suitable for x-ray diffraction study were produced. During data processing, TarDₛₐ-CTP was determined to belong to the space group P3₁21, with unit-cell dimensions a=b=92.2 and c=156.1Å. The crystal structure of TarDₛₐ-CTP was solved to 3.0Å by molecular replacement, using TagD from 𝘉𝘢𝘤𝘪𝘭𝘭𝘶𝘴 𝘴𝘶𝘣𝘵𝘪𝘭𝘪𝘴 as a search model. Unlike the search model, TarDₛₐ appears as a tetramer in the asymmetric unit. This result also confirms the gel-filtration and ultracentrifugation studies that were done previously. Although TarDₛₐ crystals were grown in the presence of CTP, the crystal structure does not reveal convincing data for the location and position of this co-factor. However, the data suggests a possible location for CTP in one of the four subunits in an orientation that differs from that of TagD_Bₛ. Unfortunately, the resolution of this data set at 3.0Å is not high enough to corroborate this finding.

abstract: Thesis

abstract: Master of Science (MS)


title: The Function of DNA Binding in the Regulation of HSV-1 Gene Expression by ICP4

contributor:
Smiley, James
Biology

subject: DNA HSV-1 gene expression

abstract: Herpes simplex virus is an important model in the study of temporally regulated gene expression in eukaryotic cells. Three classes of genes - immediate early, early, and late - are sequentially expressed during the course of lytic infection. One immediate early gene product, ICP4, is required for transactivation of most early and late genes; it is also implicated in repression of immediate early gene expression. ICP4's mechanism(s) of action is/are not yet understood; although ICP4 binds to specific sequences of DNA, whether this is necessary for transregulation by ICP4 is not clear. To gain a better understanding of how the ability of ICP4 to bind DNA relates to its transregulatory activities, I introduced ICP4 binding sites into a simple model promoter within the viral genome. Two sets of construct were made in which an ICP4 binding site (or mutant site) was placed either downstream or upstream of a TATA box, reproducing the spacing found in (i) the native 𝘐𝘊𝘗4 promoter and (ii) the native 𝘐𝘊𝘗0 promoter (respectively). The promoter of HSV-1 𝘜𝘓24𝘣 (a nonessential gene in tissue culture) was replaced with these model promoters and levels of transcripts accumulating from these constructs during lytic infection assayed by primer extension. I found that an ICP4 site placed either upstream or downstream of a TATA box shifted kinetics of expression from E/leaky L to true L. Neither the strength of the TATA box nor the helical orientation of the ICP4 binding site with respect to the TATA box affected this result.

abstract: Thesis

abstract: Master of Science (MS)


title: The Role of DIXDC1 in Autism Spectrum Disorder

title: THE ROLE OF DIXDC1 IN AUTISM SPECTRUM DISORDER AND ESTABLISHING A HIGH-CONTENT PHENOTYPING PLATFORM FOR HUMAN ASD MODELS

contributor:
Singh, Karun K
Biochemistry and Biomedical Sciences

abstract:
Autism spectrum disorder (ASD) describes a heterogeneous group of disorders with a worldwide prevalence of 1%. The two core symptoms of ASD are: 1) deficits in social communication and interaction and 2) restrictive and repetitive behaviours. Although the etiology of ASD remains unknown, environmental and genetic factors are believed to contribute to the disorder. Emerging studies suggest that molecules in the Wnt signalling pathway are important for the development of neural connectivity and are associated with ASD. We studied a Wnt signalling molecule named DIX domain containing-1 (DIXDC1) that has previously been linked to psychiatric diseases. We found that DIXDC1 regulates dendrite growth and dendritic spine formation and may function through a novel actin-dependent mechanism to regulate actin dynamics and polymerization. Our collaboration with Dr. Stephen Scherer (Hospital for Sick Children, Toronto) identified rare inherited genetic variants in DIXDC1. These variants caused an impairment of dendritic development. Furthermore, RNA sequencing identified signalling networks that were disrupted in Dixdc1 KO mouse brains, such as synaptic signalling, wnt signalling, and cell adhesion. These signalling networks are previously been implicated in ASD and we also identified different expressed genes that are strong candidate ASD-susceptibility genes. RNA sequencing also identified a novel genetic disorder that may be associated with Dixdc1 dysregulation, Ehlers-Danlos syndrome.
Lastly, we developed a high-content imaging platform for automated imaging and analysis of human iPS-derived neurons modeling ASD models. We optimized culturing of human induced-neurons in a 96-well format, and immunostaining of synaptic markers to detect deficits in synapse function. Preliminary data shows that we are able to detect synaptic phenotypes in some ASD-associated iPS cell lines. Further development of the platform should be performed for the detection of a more robust synaptic phenotype and the potential discovery of drug treatments to rescue these phenotypes.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)

abstract: Autism spectrum disorder (ASD) describes a group of neurodevelopmental disorders that affects about 1 in 59 children. Children with ASD display deficits in social communication and interaction and repetitive behaviours. Although the cause of ASD remains unknown, ASD is thought to arise from abnormalities in neuronal connectivity (connections between brain cells). Through our collaboration with Dr. Stephen Scherer (Hospital for Sick Children, Toronto), we discovered ASD-associated genetic variants (changes in the genetic code) in a gene named DIX-domain containing 1 (DIXDC1). We discovered that variants in DIXDC1 were important for proper development of neuronal connectivity. Next, we were interested in discovering the signalling networks regulating Dixdc1 function in brain development. This data suggests that Dixdc1 is involved in many pathways associated with ASD, and may be implicated in Ehlers-Danlos syndrome (EDS). Finally, we developed a platform for high-content imaging of human-derived neurons to assess synaptic disruptions caused by ASD-associated genes.


title: Multi-Scale Classification of Ontario Highway Infrastructure: A Network Theoretic Approach to Guide Bridge Rehabilitation Strategy

contributor:
Mohamed, Moataz
El-Dakhakhni, Wael
Civil Engineering

subject:
Bridge Rehabilitation
Complex Network Theory
Network Topology
Robustness
Vulnerability Index

abstract: Highway bridges are among the most vulnerable and expensive components in transportation networks. In response, the Government of Ontario has allocated $26 billion in the next 10 years to address issues pertaining to aging bridge and deteriorating highway infrastructure in the province. Although several approaches have been developed to guide their rehabilitation, most bridge rehabilitation approaches are focused on the component level (individual bridge) in a relative isolation of other bridges in the network. The current study utilizes a complex network theoretic approach to quantify the topological characteristics of the Ontario Bridge Network (OBN) and subsequently evaluate the OBN robustness and vulnerability characteristics. These measures are then integrated in the development of a Multi Scale Bridge Classification (MSBC) approach—an innovative classification approach that links the OBN component level data (i.e., Bridge Condition Index and year of construction, etc.) to the corresponding dynamic network-level measures. The novel approach calls for a paradigm shift in the strategy governing classifying and prioritizing bridge rehabilitation projects based on bridge criticality within the entire network, rather than only the individual bridge’s structural conditions. The model was also used to identify the most critical bridges in the OBN under different disruptions to facilitate rapid implementation of the study results.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: A Mechanistic Model to Examine Mercury in Aquatic Systems

contributor:
Snodgrass, W. J.
Civil Engineering

subject: aquatic mercury mechanistic model

abstract:
Elevated mercury levels have been observed in a wide variety of aquatic systems. A mass balance non-steady state model was developed to examine mercury cycling in lakes and reservoirs. Hg(ll), methylmercury, Hg° , dimethylmercury and solid phase HgS cycles were interconnected. Compartments included air, water, sediment, suspended solids, plankton, benthos, and two generic fish categories based on diet. Bioenergetics equations for individual fish were extended to consider mercury dynamics for entire fish populations. Biota represented large methylmercury fluxes in the water column and were found to be important methylmercury repositories. In a simulation of a generic well-mixed shield lake in Ontario, the fish population contained about 4 times as much methylmercury as water. Uptake of methylmercury by individual walleye and yellow perch was predicted to be dominated by the food pathway (eg. 99% of total uptake).
Based on simulations for the generic shield lake, the watershed has the potential to be an important source of methylmercury in some shield lakes (exceeding in-situ methylation in the generic simulation). Methylation in the water column and sediments were both simulated to be significant. Simulated net production of methylmercury in the generic shield lake was on the order of 0.05 to 0.15 ug methylmercury m⁻² year⁻¹ in the water column, with similar rates in sediments. Simulated rates of net methylation in polluted sytems were higher. Fractions of total dissolved Hg(II) or methylmercury available for methylation and demethylation in aerobic waters were thermodynamically predicted to be small (e.g. <1%). Dissolved organic carbon and sulphides (if present) were thermodynamically predicted to dominate Hg(II) and methylmercury complexation in freshwaters. Hg(II) burial and outflows represented about 85-90% of total mercury losses for the generic shield lake (2 year hydraulic retention time). Volatilization of Hg° , produced by demethylation and Hg(II) reduction, represented the remaining 10-15% of losses. Considerable system to system variability is expected for sources and sinks of total mercury and methylmercury in shield lakes. In simulations of two mercury contaminated environments, Lake St. Clair and Clay Lake, Ontario, sediment return of Hg(II) caused the lakes to be net sources of mercury to downstream areas. Sediment return of mercury could partially explain observed two-phase recoveries of fish methylmercury levels in some polluted systems. The time required for Hg(II) and methylmercury concentrations in various compartments to respond to changes in loads was simulated. There was a tendency towards relatively rapid internal cycling of Hg(II) and methylmercury, but slower overall system response times (eg. years to decades to respond to recover from flooding or pollution episodes).

abstract: Thesis

abstract: Master of Engineering (ME)


title: Construction and Characterization of a Chimeric Transcription Factor: EWS-PEA3

title: Construction and Characterization of EWS-PEA3

contributor:
Hassell, J. A.
Biochemistry

subject: chimera construction characterization

abstract: The activity of PEA3, a member of the Ets proto-oncogene family of transcription factors, is associated with various normal and aberrant developmental processes. PEA3 is believed to function in vivo as a transcription factor which regulates the gene expression of its cellular targets. In particular, PEA3 motifs are found in the regulatory regions of several genes implicated in tumor progression and metastasis. Aberrant PEA3 activity has been linked to the development and progression of several types of cancer, particularly, breast cancer and Ewing's sarcoma. To assist in the understanding of the role that PEA3 plays in these processes, constitutively-activated alleles of PEA3 were created by fusing a segment of the EWS gene to murine PEA3; to essentially mimic the EWS-Ets fusion proteins isolated from the human cancer syndrome, Ewing's sarcoma. Five EWS-PEA3 chimeric genes were constructed and one (EWSΔN268PEA3), is an exact murine version of an EWS-human PEA3 fusion gene isolated from Ewing's sarcoma. Transcriptional analysis of the EWS-PEA3 chimeras revealed that with the exception of one mutant, all the chimeras possessed increased transcriptional activity in comparison to normal PEA3 . Furthermore, it was suggested that the transcriptional activity of the chimeras may be regulated by Ras, although this observation requires additional validation. The chimeras were not found to possess any transforming activity, however, this finding does not suggest that the chimeras are not oncogenic in nature. In conclusion, these findings suggest that the EWS-PEA3 chimeras may indeed function as activated versions of the PEA3 transcription factor.

abstract: Thesis

abstract: Master of Science (MS)


title: The Relative Sensitivity of Four Benthic Invertebrates to Selected Metals in Spiked Exposures and Application to Contaminated Field Sediment

title: The Relative Sensitivity of Benthic Invertebrates to Metals

contributor:
Reynoldson, T. B.
Kolasa, J.
Biology

subject: benthic invertebrates metals sediment contaminate

abstract: The relative sensitivities of four benthic invertebrates (𝘏𝘺𝘢𝘭𝘦𝘭𝘭𝘢 𝘢𝘻𝘵𝘦𝘤𝘢, 𝘊𝘩𝘪𝘳𝘰𝘯𝘰𝘮𝘶𝘴 𝘳𝘪𝘱𝘢𝘳𝘪𝘶𝘴, 𝘏𝘦𝘹𝘢𝘨𝘦𝘯𝘪𝘢 spp., and 𝘛𝘶𝘣𝘪𝘧𝘦𝘹 𝘵𝘶𝘣𝘪𝘧𝘦𝘹) were determined separately for cadmium, copper, and nickel in 96-hour water-only and in spiked sediment exposures. Survival (LC25's and LC5O's), growth and reproduction (IC25's) endpoints were compared amongst the four species. In the water-only tests, 𝘏. 𝘢𝘻𝘵𝘦𝘤𝘢 is the most sensitive species to cadmium and nickel, with mean LC5O's of 0.013 and 3.6 mg/L respectively, and 𝘊. 𝘳𝘪𝘱𝘢𝘳𝘪𝘶𝘴 is the most sensitive species to copper, with a mean LC5O of 0.043 mg/L. In the spiked sediment exposures, 𝘏𝘦𝘹𝘢𝘨𝘦𝘯𝘪𝘢 spp. is most sensitive species to copper with a mean LC5O in sediment of 93 μg/g and a mean IC25 of 38 μg/g, and 𝘏. 𝘢𝘻𝘵𝘦𝘤𝘢 is most sensitive species to cadmium and nickel, with mean LC5O's of 33 and 67 μg/g respectively and mean IC25's of 10 and 40 μg/g respectively. Overall, 𝘛. 𝘵𝘶𝘣𝘪𝘧𝘦𝘹 is the least sensitive species to all metals tested, and the number of young produced/adult is the most sensitive of the reproduction endpoints for 𝘛. 𝘵𝘶𝘣𝘪𝘧𝘦𝘹. The relative sensitivities reveal that two endpoints, 𝘊𝘩𝘪𝘳𝘰𝘯𝘰𝘮𝘶𝘴 and 𝘏𝘦𝘹𝘢𝘨𝘦𝘯𝘪𝘢 survival, can be used to possibly distinguish between cadmium, copper, and nickel metal toxicity. Species test responses in field-collected sediments from areas contaminated primarily by the above mentioned metals were compared to the determined sensitivities in order to establish the causative agent of toxicity. Sediment toxicity was categorized first by comparing species responses to those established for a reference database. Responses in the field sediment support suspected toxicant in some cases, but not others. Multivariate analyses were used to assess sediment toxicity in the field sites based on the species responses, and these analyses reveal that the test endpoints respond to different environmental variables in ordination space. A comparison of test responses in the field sites to those in reference sites in ordination space reveals 13 of the 15 field-collected sites to be toxic or severely toxic.

abstract: Thesis

abstract: Master of Science (MS)


title: The Human Lysosomal Sialidase Promoter: Characterization and Stimulation as a Potential Therapy for Tay-Sachs Disease

title: The Human Lysosomal Sialidase Promoter

contributor:
Igdoura, Suleiman
Biology

subject: human lysosome sialidase tay-sachs therapy

abstract: Tay-Sachs disease and its related disorders (GM2 gangliosidoses) are neurodegenerative diseases caused by the excessive accumulation of ganglioside GM2, an otherwise non-toxic plasma membrane component, in the lysosomes of cells of the central nervous system. The accumulation of ganglioside GM2 is the result of a defect in the gene encoding the α-subunit of β-hexosaminidase A (Hex A), an acid hydrolase responsible for the metabolism of gangloside GM2 in the lysosome. Though a debilitating disease in humans, Tay-Sachs model mice (𝘏𝘦𝘹𝘢-/-) escape symptoms by the action of lysosomal sialidase, which is expressed in mice at levels sufficient to metabolize ganglioside GM2 and effectively "bypass" Hex A deficiency. In an attempt to understand why a lysosomal sialidase-mediated bypass of Hex A deficiency is not observed in humans, we cloned ~ 2.9 kb of the human lysosomal sialdiase promoter and began characterization of the regulatory machinery that determines its activity. The transcription factor CDP (CCAAT -Displacement Protein) and truncations thereof were found to have a clear and consistent effect on promoter activity 𝘪𝘯 𝘷𝘪𝘵𝘳𝘰, with the truncation CDP⁸³¹⁻¹⁵⁰⁵ resulting in a near 50-fold increase in activity. Adenovirus-mediated gene transfer of CDP⁸³¹⁻¹⁵⁰⁵ into CRB/TSD cells, a human Tay-Sachs neuroglia cell line, resulted in elevated lysosomal sialidase activity and a decrease in ganglioside GM2 stores. These results suggest that the regulatory machinery responsible for lysosomal sialidase expression may be manipulated in such a way as to "activate" a sialidase-mediated bypass of Hex A deficiency in human Tay-Sachs cells. Thus, induction of lysosomal sialidase may have a potential therapeutic benefit in human Tay-Sachs disease and other Hex A-deficient GM2 gangliosidoses.

abstract: Thesis

abstract: Master of Science (MS)


title: Changes in the Element Composition of Globoids from Cucurbita Maxima and Cucurbita Andreana Cotyledons During Early Seedling Growth

title: Changes in Globoid Composition During Early Seedling Growth

contributor:
Lott, John
Biology

subject: globoids Cucrubita seed growth element

abstract: The cells of 𝘊𝘶𝘤𝘶𝘳𝘣𝘪𝘵𝘢 embryos contain may protein bodies surrounded by smaller lipid vesicles. Within the protein bodies are discrete spherical bodies called globoids. Globoids are made up of phytin, and are an important store of 𝘮𝘺𝘰-inositol, phosphorus, and cations including K, Mg, Ca, Mn, Fe and Zn. During early seedling growth, the protein bodies fuse together to form aqueous vacuoles, and the globoids are degraded, their mineral nutrient stores used by the growing seedling. The changes in the element composition of globoids during early seedling growth were examined in this study and the influence of light and mineral nutrient conditions on the changes were examined. Energy dispersive X-ray analysis was used to determine the element composition of globoids from the cotyledons of 𝘊. 𝘮𝘢𝘹𝘪𝘮𝘢 and 𝘊. 𝘢𝘯𝘥𝘳𝘦𝘢𝘯𝘢 seeds and seedlings at various stages of growth. The stages selected ranged from the mature, dry seed, to an established seedling with an elongated hypocotyl and expanded cotyledons. To investigate the influence of light and mineral nutrient conditions, seedlings were grown under four different sets of growth conditions: in the dark, with deionized water; in the dark, with Hoaglands solution; in the light, with deionized water; in the light, with Hoaglands solution. During early seedling growth, the element composition of globoids changed. In both species, regardless of growth conditions, the same general trend was observed for each element: P remained relatively constant, K decreased markedly and Mg, Ca, Mn, Fe, and Zn generally increased. As the protein bodies fused and became more aqueous, it appeared that K ions came off the phytate molecule and were replaced by di-and trivalent cations with a higher affinity for phytic acid. There were species-to-species differences in globoid composition changes which could be attributed, at least in part, to differences in the Ca content of the mature, dry embryos. In 𝘊. 𝘢𝘯𝘥𝘳𝘦𝘢𝘯𝘢, which had a higher initial Ca content, there was a large increase in the Ca content of the globoids during seedling growth and no significant increase in Mn. In 𝘊. 𝘮𝘢𝘹𝘪𝘮𝘢 globoids there was only a slight increase in Ca, but there was a much larger increase in Fe, Zn and Mn than occurred in 𝘊. 𝘢𝘯𝘥𝘳𝘦𝘢𝘯𝘢. Light and dark grown seedlings exhibited distinctly different morphological features, but light conditions alone did not have a significant influence on the changes in globoid composition. In combination with mineral nutrients in the later stages of growth, the presence of light resulted in a more rapid degradation of globoids. Mineral nutrient conditions had some effect on globoid composition, affecting mostly elements which were present in large amounts. The effect of mineral nutrient conditions, and its interactions with light conditions may have been mediated through changes in the mobilization of mineral nutrients out of the cotyledons during seedling growth. There were very large (5 -7μm in diameter) globoid-like particles present in some later stage cotyledon samples of both species. There was no apparent pattern to which samples they were found in. These particles had elemental compositions which were consistent with them being composed of phytin. Such large particles had not previously been found in cucurbit tissues.

abstract: Thesis

abstract: Master of Science (MS)


title: An Offline Dynamic Programming Technique for Autonomous Vehicles with Hybrid Electric Powertrain

contributor:
Emadi, Ali
Mechanical Engineering

subject:
autonomous vehicles
hybrid electric vehicles
energy management
dynamic programming

abstract:
There has been an increased necessity to search for alternative transportation methods,
mainly driven by limited fuel availability and the negative impacts of climate
change and exhaust emissions. These factors have lead to increased regulations and a
societal shift towards a cleaner and more e cient transportation system. Automotive
and technology companies need to be looking for ways to reshape mobility, enhance
safety, increase accessibility, and eliminate the ine ciencies of the current transportation
system in order to address such a shift. Hybrid vehicles are a popular solution
that address many of these goals. In order to fully realize the bene ts of hybrid vehicle
technology, the power distribution decision needs to be optimized. In the past,
global optimization techniques have been dismissed because they require knowledge
of the journey of the vehicle in advance, and are generally computationally extensive.
Recent advancements in technologies, like sensors, cameras, lidar, GPS, Internet of
Things, and computing processors, have changed the basic assumptions that were
made during the vehicle design process. In particular, it is becoming increasingly
possible to know future driving conditions. In addition to this, autonomous vehicle
technology is addressing many safety and e ciency concerns. This thesis considers and integrates recent technologies when de ning a new approach
to hybrid vehicle supervisory controller design and optimization. The dynamic
programming algorithm has been systematically applied to an autonomous
vehicle with a power-split hybrid electric powertrain. First, a more realistic driving
cycle, the Journey Mapping cycle, is introduced to test the performance of the
proposed control strategy under more appropriate conditions. Techniques such as
vectorization and partitioning are applied to improve the computational e ciency of
the dynamic programming algorithm, as it is applied to the hybrid vehicle energy
management problem. The dynamic programming control algorithm is benchmarked
against rule-based algorithms to substantively measure its bene ts. It is proven that
the DP solution improves vehicle performance by at least 9 to 17% when simulated
over standard drive cycles. In addition, the dynamic programming solution improves
vehicle performance by at least 32 to 39% when simulated over more realistic conditions.
The results emphasize the bene ts of optimal hybrid supervisory control and
the need to design and test vehicles over realistic driving conditions. Finally, the dynamic
programming solution is applied to the process of adaptive control calibration.
The particle swarm optimization algorithm is used to calibrate control variables to
match an existing controller's operation to the dynamic programming solution.

abstract: Thesis

abstract: Master of Applied Science (MASc)


title: Heavy Metal Contents in Surficial Sediment of Banjir Kanal Barat and Babon Rivers, Semarang, Central Java, Indonesia

contributor:
Risk, Michael
Biology

subject:
metal
heavy metal
sediment
river

abstract:
Bottom sediment (0 -5 cm) along the Banjir Kanal Barat (Garang River) and Babon Rivers which are situated in Semarang, Central Java, Indonesia were analyzed for their trace/heavy metals content Eight elements namely Nickel (Ni), Copper (Cu), Lead (Pb ), Chromium (Cr), Cadmium (Cd), Zinc (Zn), Iron (Fe), and Manganese (Mn) were investigated. Their concentrations provide information related to the industrial and municipal discharge. There are serious concerns about the contamination in the study area, and previous studies found some elevated concentration of several metals (trace elements). Total metal analyses of the fine (< 63 μm) sediment fraction by Atomic Absorption Spectrophotometer using strong acid digestion indicated high (Ni, Cu, Zn, and Mn) metal contamination. Weak acid digestion of total sediments (whole fraction) showed relatively low Cd to moderately (Cu, Cr, and Pb) levels. High Iron concentration was detected using X-RF Fluorescence.
The result of trace/heavy metal and sediment characteristic analyses were statistically processed by Spearman's Rank Correlation analyses. In the Babon River, weak acid digestion results found a strong correlation between organic carbon and Chromium. Sediment characteristics, particularly in terms of organic carbon, appeared to be the primary factor controlling metal concentration. In Babon River, strong acid digestion showed that most metals were highly correlated with Mn (𝘱 < 0.05) , except Zn. In Banjir Kanal Barat River, weak acid digestion results show that Copper (Cu) was highly correlated with organic carbon. From strong acid digestion results significant relationship was found between Zn and Mn (𝘱 < 0.05) . Analyses of surficial sediment in Banjir Kanal Barat River demonstrate very little significant correlation between metals and sediment characteristics. This condition probably reflected the diverse nature of metal input into the system, either originated from point or non-point sources. However, statistical (t-test) analyses suggested that there were contamination of Ni, Cu, and Zn in both rivers. Most of these values exceeded the Canadian Standard/Guidelines for contaminated soils and sediments. In addition, t-test result also showed different levels of contamination between Banjir Kanal Barat and Babon Rivers. Mean values indicated higher contamination in Banjir Kanal Barat River compared to Babon river.

abstract: Thesis

abstract: Master of Science (MS)


title: Ancestry of the Indian Population Determined by Y Chromosome Markers

contributor:
Singh, Rama
Biology

subject: India ancestry chromosome marker population

abstract: Seven microsatellites, DYS 388, DYS 3891, DYS 389II, DYS 390, DYS 391, DYS 392 and DYS 393 and a biallelic locus DYS 271 were analyzed in the Indian population with the aim of understanding the relationships of the Indo-European and the Dravidian population of India with those of the European /Central Asian populations. The 116 Indian samples, used in the study, enjoy a wide geographical distribution and represents well the different religions and caste groups of India. Supporting previously published results, most variation is found between populations within continents than between continents. No significant differences were found between the different religious and caste groups of India with those of the World populations. All the alleles of the different markers are well represented in the different ethnic groups of India, and thus, does not support the popular belief that the highest diversity exists within the middle caste. Significant differences in the distribution of alleles are found in different regions of India especially between the North and the South. A phylogenetic relationship appears to exist between the Sindhis from South Pakistan with those of the South Indian population. This lends support to the belief that the present population from Sind might represent a remnant population of the original inhabitant of the region that was mainly pushed further to the Southern part of Subcontinent by later invasions. A phylogenetic relationship also exists between the Indian population and the Burushaski population from Northwest Pakistan and with the Kazakhs, Kirgiz and the Uighurs from Central Asia. This is in agreement with previously published results, and supports the occurrence of two main population movements from Central Asia into India at different time intervals that gave birth to the two main language families-the Dravidian and the Indo-European languages in India.

abstract: Thesis

abstract: Master of Science (MS)


title: A Comparitive Biochemical Study of the Enzymes of Choline Synthesis in Several Dicotyledon Families

title: Enzymes of Choline Synthesis in Dicot Families

contributor:
Weretilnyk, E. A.
Biology

subject: dictoyledon choline compare biochemistry enzyme

abstract: Choline is universal among plants as phosphatidylcholine and in many plants it serves as a precursor for the compatible osmolytes glycine betaine and choline-𝘖-sulphate. In spinach, choline is synthesized by the sequential 𝘕-methylation of phosphoethanolamine (PEA) → phosphomethylethanolamine (PMEA) → phosphodimethylethanolamine (PDEA) → phosphocholine (PCho) and PCho is hydrolyzed to choline. The objective of this biochemical survey was to determine whether the activities of enzyme(s) converting PEA to PCho could be found in leaves of diverse plants and, if so, if common regulatory properties could be identified. Leaf tissue was harvested from 14 diverse dicot plants. Enzyme activities for the three sequential 𝘕-methylations were quantified in vitro and for representative assays using PEA as substrate, reaction products were identified by thin layer chromatography. Extracts of all plants tested could metabolize PEA to PMEA, the rate of conversion varied from 0.04 to 25 nmol · min⁻¹ · g⁻¹ Fresh wt for soybean and cotton, respectively. In vitro PMEA → PDEA and PDEA → PCho rates varied between the plant species tested. Both steps were highest in sugar beet (22 and 24 nmol · min⁻¹ · g⁻¹ Fresh wt for · PMEA → PDEA and PDEA → PCho, respectively) to below detection limits for soybean (<0.03 nmol· min⁻¹ · g⁻¹ Fresh wt). Upon dark exposure, PEA → PMEA reaction rates were reduced from the light period levels but not in all cases was the activity reduced beyond the level that could be attributed to a general loss in plant vigour. The reduction in 𝘕-methylation capacity was most pronounced in plants with the highest levels of PEA → PMEA activity, with reduction greatest in sugar beet > amaranth > spinach. Thus PEA → PMEA is catalyzed by a light-regulated enzyme in many but apparently not all dicot plants. Datko and Mudd (1988a) have proposed that PEA → PMEA conversion is ubiquitous among plants and the enzyme responsible catalyzes a committing step for PCho synthesis. PEAMeT activity was found in leaf extracts of 10 additional dicot species. The level of in vitro activity and light regulation is not equivalent among all plants examined. If in vitro rates faithfully reflect the in vivo capacity to synthesize choline, why the variability among plants with respect to their capacity to synthesize a universal metabolite? Alternate routes of PCho/phosphatidyl choline synthesis may explain these differences (Datko and Mudd, 1988a,b; Hanson and Rhodes, 1983; Hitz 𝘦𝘵 𝘢𝘭., 1981; Weretilnyk and Summers, 1992). Interestingly, the plants with the highest rates of PEA → PMEA activity, (cotton, sugar beet, amaranth, sunflower, spinach and statice) are all documented glycine betaine accumulating species. These plants may have higher rates of PEA methylation in order to meet requirements for osmolyte synthesis. Thus, it would be interesting to see if PEA metabolism to PCho is up-regulated in response to osmotic stress.

abstract: Thesis

abstract: Master of Science (MS)


title: Sediment Production via Bioerosion by Cliona Viridis on Grand Cayman Island, B. W. I.

contributor:
Risk, M. J.
Geology

subject: sediment bioerosion cliona

abstract: The overgrowing, boring sponge Cliona viridis was studied on the Southwest coast of Grand Cayman Island, British West Indies. The surface area covered by the sponge was estimated using transect and quadrat surveys. Between 1 and 8 m depth, the average substrate coverage was 5%. Smaller sponge colonies were usually subcircular and larger colonies more dendritic. This change in shape may aid in exploiting new substrate. The sponge removes between 13.9% and 32.2% of the substrate as it expands laterally and produces an average erosional rate of 0.6 mm yr ⁻¹. Average sediment production rate is 1 kg m ⁻²  yr ⁻¹. The chips produced by the sponge comprised only 0.0122% to 1.250% of the bottom sediments. Presumably, the majority of the sponge-produced sediments were transported out by water currents.

abstract: Thesis

abstract: Bachelor of Science (BSc)


title: Evaluating Patient Satisfaction in the Neuroscience Patient Population

title: Evaluating Patient Satisfaction in the Neuroscience Poipulation

contributor:
Synge, Jane
Wells, John

subject: patient satisfaction neuroscience

abstract: Patient satisfaction regarding health care has been recognized as an important variable for promoting effective and efficient utilization of health care services, improving compliance with treatment regimes, improving health outcomes for the patient and eliciting patients for future care (Charles, Gauld. Chambers, O'Brien, Haynes & LaBelle, 1994,p.1814). Since the basic premise of health care is to improve the health of others, improving the level of satisfaction with care is essential. Also, with the cuts in financial support for Ontario health care, efficient utilization of health care resources and improved health outcomes are primary goals for hospital administrators, health professionals and politicians. The Neuroscience Program, at the Hamilton Health Science Corporation (HHSC), felt it necessary to evaluate the current level of patient satisfaction from the neurological patients and their family members, to identify opportunities for improvement in care, and to identify whether the neurological impaired patients and their families have unique care needs. A review of the research on patient satisfaction revealed that neurological patient's had not been specifically studied for their level of satisfaction with their health care. In other bodies of research, the neuroscience patient population had been identified as needing frequent, current information and communications in understandable terms. For the patients who sustain cognitive. behavioural, and speech impairments, and those with a decreased level of consciousness, these patients and family members identified information and support as their highest needs. The need for hope was also identified as a priority. In the general patient population, the need for sufficient personal care, emotional support, and increased family involvement in the patient's care were acknowledged as additional areas for improvement. Discharge planning was also recognized as being an area in need of significant improvements. In analyzing the information available to the Neuroscience Program regarding current level of patient satisfaction, there were only three main sources of information. These three sources were the letters from patients and families regarding care, the previous corporate discharge questionnaire, and a focus group study. In reviewing these data themes similar to those noted above were recognized. The need for timely, pertinent, understandable information and education was imperative. In addition, safety and personal care issues were identified, especially in the case of very ill or very confused patients. Finally, the greatest concern noted by the patients and families was the fear that their feedback might go back to the health care team, potentially jeopardizing their future care. These concerns were most pronounced in the case of patients with diagnostic conditions such as head injury, brain hemorrhage (vascular) and brain tumours (neoplasia), hydrocephalus and spinal cord injuries with impairment. These patients also tended to have the longest stays in hospital and the highest levels of disability. The stakeholders of the Neuroscience Program were interviewed to examine the most relevant areas for study. Communication, information and education were identified as pivotal to improvement in all other aspects of care. A qualitative method of examination was felt to be the most appropriate to collect extensive information. Also, quantitative data would be collected on a patient satisfaction survey that was being implemented by the HHSC. The critical incident technique, by Flanagan (1954), was chosen as the preferred method of data, as it allowed for a consistent focus to the interviews while still collecting in-depth information. In reviewing and utilizing all of the above information, the research project is outlined using Flanagan's framework and the cycle for improvement outlined by the Joint Commission on Accreditation of Healthcare Organizations. Each step of the process is outlined from the design phase, data collection, data analyses, interpretation and implementation of the improvements. The study, once implemented, should be viewed as a year-to-year process and as being an integral part of the overall quality plan for evaluating patient satisfaction. A database should be established bringing together both patient and family information in order to assess for changes over time.

abstract: Thesis

abstract: Master of Science (Teaching)


title: Inter- and Intrapopulation Analysis of Bird Species: Results from VNTR and MHC Genetic Markers

title: Population Genetic Structure of Birds

contributor:
Gibbs, H.
Biology

subject: bird population analysis genetic markers

abstract:
Thesis
Master of Science (MS)


title: The Ionoregulatory Physiology of Freshwater-Adapted Mummichog (Fundulus Heteroclitus)

title: Ionoregulation of Freshwater-Adapted Fundulus Heteroclitus

contributor:
Wood, C. M.
Biology

subject: ionoregulation freshwater mummichog fundulus

abstract: This thesis examined the ionoregulatory physiology of freshwater-adapted mummichog (𝘍𝘶𝘯𝘥𝘶𝘭𝘶𝘴 𝘩𝘦𝘵𝘦𝘳𝘰𝘤𝘭𝘪𝘵𝘶𝘴) 𝘪𝘯 𝘷𝘪𝘷𝘰 and its interaction with acid-base regulation. Under control conditions (water [NaCl] ≈ 0.7-1 .0 mmol· L⁻¹, [Ca²⁺] ≈ 0.1 or 1.0 mmol· L⁻¹), Na⁺ turnover was vigorous with a positive Na⁺ balance maintained, whereas unidirectional Cl⁻ influx was virtually zero resulting in a slight negative Cl⁻ balance. Michaelis-Menten analysis revealed a low affinity, high capacity Na⁺ uptake mechanism that was independent of both Na⁺ efflux and ammonia excretion. Cl⁻ uptake started at higher water [NaCl] levels ( > 2 mmol • L⁻¹) but did not saturate within the freshwater [NaCl] range, indicating a completely different uptake mechanism, independent from Na⁺ influx. Using both internal and environmental manipulation, Na⁺ uptake was found not to be coupled to ammonia excretion. Instead, a link with acid excretion (Na⁺ /H⁺ exchange or Na⁺ channel/H⁺ -ATPase coupling) remains possible but could not be confirmed. There was no evidence for the presence of a Cl⁻/HC0₃⁻exchange mechanism in the gills. However, mummichog were capable of differentially manipulating Na⁺ and Cl⁻ efflux components as an additional response to an internal acid-base disturbance. This ability and the suggested Na⁺ uptake/acid excretion coupling indicate that mummichog resemble other freshwater fish in that an iono/acid-base relationship exists. In these studies, the use of the Strong lon Difference Theory as a means of assessing acid-base balance through the measurement of differential Na⁺ and Cl⁻ fluxes proved to be acceptable and practical alternative to the measurement of acid-base fluxes by traditional titration methodology. Finally, whole-body Ca²⁺ uptake was investigated using a recently developed technique for small fish. Ca²⁺ uptake by the mummichog involves a carrier-mediated step as revealed by saturation of uptake as external [Ca²⁺] increased. Inhibition of uptake by external La³⁺ but not Mg²⁺ suggested that apical Ca²⁺ channels are involved in the uptake process but are not voltage-gated. Chronic exposure to low Ca²⁺ water resulted in a stimulated Ca²⁺ uptake, most likely in response to depletion of internal Ca²⁺ levels whereas chronic exposure to high Ca²⁺ did not elicit any changes in uptake. This thesis revealed that the freshwater-adapted mummichog does share certain ionoregulatory qualities with other freshwater fish but at the same time possesses unique characteristics which may reflect its euryhaline nature

abstract: Thesis

abstract: Master of Science (MS)


title: A RANDOMIZED WAIT-LIST, PILOT DESIGN THESIS: Feasibility of the Web Accessible Population Pharmacokinetic Service-Hemophilia (WAPPS-Hemo) Tool in Severe Hemophilia Patients Undertaking Personalized Regimen Tailoring

contributor:
Iorio, Alfonso
Health Research Methodology

subject: hemophilia wapps-hemo prophylaxis

abstract: A design pilot study proposed as a Canadian, multicenter, open-label, randomized waitlist clinical trial over the duration of six months to determine the success of running a full-scale RCT with the newly designed WAPPS-Hemo calculator in the Canadian Hemophilia community. The WAPPS-Hemo calculator is widely viewed as a beneficial tool to clinicians and patients and has the potential to optimize and tailor the prophylaxis regimen for hemophilia patients.

abstract: Thesis

abstract: Master of Science (MSc)


title: Prime Maltsev Conditions and Congruence n-Permutability

contributor:
Valeriote, Matthew
Mathematics and Statistics

subject: Universal Algebra, Maltsev Condition, Prime, Congruence n-permutable varieties, idempotent, locally finite

abstract:
For $n\geq2$, a variety $\mathcal{V}$ is said to be congruence $n$-permutable if every algebra $\mathbf{A}\in\mathcal{V}$ satisfies $\alpha\circ^n\beta=\beta\circ^n\alpha$, for all $\alpha,\beta\in \Con(\mathbf{A})$. Furthermore, given any algebra $\mathbf{A}$ and $k\geq1$, a $k$-dimensional Hagemann relation on $\mathbf{A}$ is a reflexive compatible relation $R\subseteq A\times A$ such that $R^{-1}\not\subseteq R\circ^k R$. A famous result of J. Hagemann and A. Mitschke shows that a variety $\mathcal{V}$ is congruence $n$-permutable if and only if $\mathcal{V}$ has no member carrying an $(n-1)$-dimensional Hagemann relation: by using this criterion, we provide another Maltsev characterization of congruence $n$-permutability, equivalent to the well-known Schmidt's and Hagemann-Mitschke's (\cite{HagMit}) term-based descriptions.

We further establish that the omission by varieties of certain special configurations of Hagemann relations induces the satisfaction of suitable Maltsev conditions. These omission properties may be used to characterize congruence $n$-permutable idempotent varieties for some $n\geq2$, congruence 2-permutable idempotent varieties and congruence 3-permutable locally finite idempotent varieties, yielding that the following are prime Maltsev conditions:
\begin{enumerate}
\item congruence $n$-permutability for some $n\geq2$ with respect to idempotent varieties;
\item congruence 2-permutability with respect to idempotent varieties;
\item congruence 3-permutability with respect to locally finite idempotent varieties.
\end{enumerate}

Finally, we focus on the analysis of a family of strong Maltsev conditions, which we denote by $\{\mathcal{D}_n:2\leq n<\omega\}$, such that any variety $\mathcal{V}$ is congruence $n$-permutable whenever $\mathcal{D}_n$ is interpretable in $\mathcal{V}$. Among various other properties, we also show that the $\mathcal{D}_n$'s with odd $n\geq3$ generate decomposable strong Maltsev filters in the lattice of interpretability types.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Determination of the Sternocleidomastoid Muscle Function Using Head Lift

title: Sternocleidomastoid Function

contributor:
Pengelly, L.
Engineering Physics

subject: sternocleidomastoid muscle head

abstract: Forces associated with head lifting efforts as well as mouth pressure were measured on four supine normal men, at five different lung volumes from FRC to TLC, and with the head positioned at two different heights above the bed. Positioning the head at one of the two heights (3cm and 10cm) provided for a change in length of the sternocleidomastoid (SCM) muscle. Graded efforts of head lift, and graded inspiratory pressure manoeuvres were executed and corresponding electromyograms of the SCM were measured. The mass lifted during efforts of head lift under static conditions (HSL) was measured with a self-contained transducer system located under the head of the subject. The muscle pressures at different lung volumes were obtained from pressure transducer records by adding the pressure-volume relaxation curve to the inspiratory mouth pressure-volume curve. The electromyogram of the SCM was obtained from surface electrodes, amplified and processed with a smoothing integrator to obtain the mean rectified electromyogram (MRE). For every subject, the relationships between MRE and MASS LIFTED, and between MRE and MUSCLE PRESSURE were linear for every lung volume at every head height above the bed ( r² >0.95 ). Data from all subjects were put together to form a single linear relationship (MRE vs MASS LIFTED and MRE vs MUSCLE PRESSURE) for every head height above the bed. The variability was greater at 3cm than at 10cm of head height. For both the head lift manoeuvre and the respiratory manoeuvre, there was a greater variability due to lung volume, on the slope and intercept of the curves at 3cm, than at 10cm of head height. Furthermore, more EMG was generated at 10 cm than at 3cm for a constant mechanical output, i.e., head lift or muscle pressure. Statistical tests were performed on the curves. Slope and intercept of the curves at different lung volumes, for a specific manoeuvre and head height above the bed were not significantly different ( p<0.05 ). The curves at different lung volumes were then put together to form a single linear relationship for both manoeuvres at both heights. Slope and intercept of the "pooled" curves, at both 3cm and at 10cm, were tested for both head lift and respiratory manoeuvres. It was found that the slopes were significantly different ( p<0.05 ) while the intercepts were net. Using the input variable, MRE, as the common factor, a linear relationship between the two output variables, MASS LIFTED and MUSCLE PRESSURE, was determined at each head height. Interpretation of the resulting relationships shows that: (a) About 50% of the maximum inspiratory muscle pressure can be generated without using the SCM muscle. (b) For the head located at 3cm above the bed, the production of muscle pressure from 50% to 100% Pmusc(max) corresponds to lifting, with the head, a mass equivalent to 4.5 times the head mass, while at 10cm above the bed, the same respiratory manoeuvre corresponds to lifting a mass equal to 1.3 times the head mass. (c) Changes in lung volume do not bring about as great changes in length of the SCM muscle as do changes in head height.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Accounting for Uncertainty in Cost-Effectiveness Studies

contributor:
Willan, A. R.
Statistics

subject: uncertainty cost cost-effective

abstract: Due to an increasing demand from decision makers for proper economic evaluations of health care services, cost-effectiveness analyses are becoming increasingly frequent. The statistic of interest in cost-effectiveness analysis is the incremental cost effectiveness ratio (ICER). When patient-specific data on costs and effects of alternative interventions is available, it can be used to quantify the uncertainty in the estimate of the ICER. Expressing this uncertainty by using confidence intervals has been recommended. However, because the statistic of interest is a ratio of two correlated random variables, its variance cannot be estimated exactly. Furthermore, the distribution of the ratio is unknown. Recently, several approximate methods have been proposed for calculating confidence intervals for the incremental cost-effectiveness ratio. These include two parametric methods: one which relies on a Taylor's Series approximation of the variance, and one based on Fieller's theorem; as well as a number of methods which rely on bootstrapping methodology. In this manuscript, these methods were applied to data obtained from a randomized clinical trial in which both health resources consumed and health outcomes were observed. Furthermore, several variations of the bootstrapping methods were proposed and applied to the same data set. Probabilities of the true ICER being in given ranges were also estimated using a bootstrapping approach. Finally, issues of sample size and power were briefly considered. The relative advantages and disadvantages of the different approaches were discussed.

abstract: Thesis

abstract: Master of Science (MS)


title: THE TIMING AND TYPE OF ALLIANCE PARTNERSHIPS IN THE NEW PRODUCT DEVELOPMENT PROCESS

contributor:
Pujari, Ashish
Wu, Ruhai
Business

subject:
Innovation
New Product Development
New product alliances
Partnership type
Partnership timing
Biopharmaceutical

abstract:
Recent years have witnessed a growing concern for the ability of firms to effectively manage their new product innovation in the face of disruptive technological changes, increased global competition, and rising costs of research and development. These concerns notwithstanding, firms are additionally required to launch radical new products to the market, as incremental new products provide their developers with only short-term sales and profitability. In response to these challenges, firms have entered into collaborative alliances to share the risks and costs involved in the new product development (NPD) process and to enhance their product innovation performance.
Turning research discoveries into marketable radical new products through collaborative alliances is even more important for relatively small firms operating in technologically intensive industries. Such firms are often underfunded and unable to undertake a full NPD cycle internally due to an inability of assembling the right mix of internal capabilities. The inevitable need to access capabilities from alliance partners may lead some small firms to form collaborative alliances under unfavourable situations, which make alliances prone to failure (70% by some estimates) to reach new product innovation goals. The substantial rate of alliance failure is embedded in a clash between the logic of radical new product innovation management (the need for flexibility between alliance partners), and recommendations for alliance management (the need to determine the responsibilities of each partner from the onset of the alliance). Despite the benefits of alliances in providing required resources, alliances can impose substantial transaction costs to focal small firms. Thus, it is crucial to investigate how firms, particularly small firms, can make a balance between the benefits and costs involved in alliances, to mitigate alliance risks and increase the probability of new product radicalness.
In this thesis, I introduce a new typology and demonstrate its application to product performance. The typology categorizes alliance partnerships along two dimensions of partnership timing (the stage of the NPD process during which alliance is formed) and partnership type (the role of alliance partner during the NPD process). I use this this typology to determine the interaction effects of partnership timing and type on the probability of product innovativeness (radicalness). To this end, I rely on insights from Transaction Cost Economics (TCE) and Resource Based View of the firm (RBV) theories as well as the absorptive capacity concept to develop testable hypotheses. I use a sample of 230 drugs developed by 85 biotechnology firms in collaborative alliances with 384 alliances in 1982-2016 with universities and research institutes, other biotechnology firms, and pharmaceutical firms formed during discovery, development, and prelaunch stages of the new drug development process.
I find that the probability of drug radicalness increases when alliances with universities and research institutes, as well as other biotech firms, are formed during the discovery or development stages of the new drug development. However, results indicate that partnership with pharma firms during the discovery or development stages reduces the likelihood of drug radicalness. During the prelaunch stage, except for negative relation between alliances with other biotech and drug radicalness, results failed to find a significant relationship between university as well as pharmaceutical partnership and drug radicalness.
By disintegrating alliances along two dimensions of partnership type and timing, this thesis substantially increases the understanding of the benefits and costs of each partnership type and during each stage of the NPD process. This helps relatively small firms to better understand when and with whom during the process of NPD they need to initiate alliances to increase their likelihood of product radicalness. This thesis also contributes to the current theoretical insights of TCE and RBV theories by considering costs and benefits of each partnership type variant along different stages of the NPD process. Methodologically, instead of focusing on analysis using firm level outcome variables (count number of new products), this thesis turns the unit of analysis to product level (innovativeness of the product) and links each product to its designated alliance attributes (timing and type) to provide more subtle and fine-grained implications.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Studies of Segmented Polyurethanes for Blood Contacting Applications

contributor:
Brash, J. L.
Chemical Engineering

subject: polyurethane blood segment

abstract: A series of segmented polyurethanes (SPU's) potentially suitable for blood contacting applications were synthesized. Various soft segment monomers (polypropylene glycol, PPG, MW 1000; PPG 2000; polyethylene glycol, PEG, MW 1500) and chain extenders (ethylene diamine; 1,3 diamino hydroxy propane; and 4,5 dihydroxy-m-benzene disulphonic acid disodium salt, Tiron®) were used to prepare polymers with a range of chemical and physical characteristics. Several of these polymers were novel with respect to the presence of functional groups in the hard segment. The principal objective was to assess the effect of these groups on the physical properties, and to some extent on the blood compatibility of SPU's. Initially the SPU's were characterized to determine the course of the novel polymerizations. Nuclear magnetic resonance (NMR) was used to determine if the hydroxyl group of the chain extender 1,3 diamino hydroxy propane remained unreacted. Although the lack of model compound studies made the results inconclusive, it was estimated, using ¹H NMR, that about 87% of the hydroxyl groups remained unreacted. Sulphur analysis of sulphonate-containing SPU's, formed using Tiron®, showed very low sulphur contents compared to the expected values, suggesting that the repeat units of the SPU's were different from those based on simple stoichiometry. Low angle laser light scattering (LALLS) was used to determine M̅w but did not always produce interpretable results. Electron spectroscopy for chemical analysis (ESCA) was performed on cast films of the polymers to determine chemical composition at the surface. The ESCA data obtained at varying take-off angles showed that the soft segment domains were enriched at the surface. The nitrogen content expected of several of the SPU's was twice that found by ESCA. Again this suggests that the repeat unit of these SPU's is different from the ideal repeat unit based on the stoichiometry used. Mechanically the polymers behaved as expected in terms of stress-strain data. PPG 2000-based SPU's had greater extensibility but lower tensile strength compared to the corresponding PPG 1000-based SPU's. PEG-based polymers had very low mechanical strength and this was attributed to the absorption of water from the environment by these hydrophilic materials. PPG 1000-based polymers showed the best overall mechanical performance from a biomaterial perspective. As a means of assessing the response of blood to these materials, the adsorption of fibrinogen on film coated tubes was studied, both from single protein solutions and from plasma. Fibrinogen "capacity" of the polymer surfaces obtained from the single protein data was strongly dependent on soft segment type and was in the order PPG 1000>PPG 2000> PEG 1500. As with most other materials previously studied, adsorption of fibrinogen from plasma was transient (Vroman effect). This effect was evident as peaks in curves of adsorption versus plasma concentration. The peak heights were found also to be in the order PPG 1000>PPG 2000> PEG 1500. These peak heights are in general also lower than for other, more thrombogenic materials, and may indicate the affinity of the surface for fibrinogen relative to other proteins in plasma. From these observations it is tempting to associate thromboresistance with minimal fibrinogen adsorption.

abstract: Thesis

abstract: Master of Science (MS)


title: Determining the Factors that Affect the General Health of the Respondents of Ontario

contributor:
Shannon, Harry
Childs, Aaron
Statistics

subject:
health
factor
ontario
respondent
CCHS
sampling weight
logit model
canada

abstract: In September 2002, the Canadian Institute of Health Information, Health Canada and the National Task Force on Health Information created the Canadian Community Health Survey (CCHS) whose objective was to determine the status of the Canadian health care system and the health status of Canadians themselves. The CCHS was divided into two cycles (Cycle 1.1 and Cycle 1.2) of which CCHS Cycle 1.1 was general population health survey designed to provide information for 136 health regions covering all provinces and territories. For this particular report, data from Cycle 1.1 was analyzed in order to determine if Work stress, Type of Smoker, Body Mass Index (BMI) and Household Income were significant factors contributing to the general health of the population of Ontario. Each of the above mentioned variables was considered individually for a given age, gender and marital status of the respondents. Logistic Stepwise Regression was used to determine if these variables were significant predictors of general health and all the possible two way interactions were explored at the five percent level. Furthermore, a diagnostic check of the fitted models was conducted and the validity of the models was assessed once again after removing the influential points. In addition, the linearity of all the continuous variables was tested in the logit models followed by a comparison of the fitted models using weights. Overall, it was found that all of the potential predictor variables of concern were significant predictors of general health. The majority of two way interaction terms were included in the fitted models, however, the overall fit of some models was found to be poor. In some cases, upon removing the influential points, the overall fit improved significantly, while for others, the fit did not improve by much. Also, it was found that Household Income and Work stress were not linear in the logit model while Age was found to be linear. Upon comparing models with and without sampling weights, it was found that the model that included sampling weights consisted of the same main effects as the model without sampling weights, along with additional interaction terms which were not present earlier. KEY WORDS: CCHS, Sampling Weights, Logit Models, Fitted Models, Interactions, Stepwise Regression

abstract: Thesis

abstract: Master of Science (MS)


title: Cost-Effectiveness Analysis When the Willingness to Accept is Greater Than the Willingness to Pay

subject: cost cost-effective analysis pay accept

abstract: There are three approaches to health economic evaluation for comparing two therapies: cost minimization, incremental cost-effectiveness ratios (ICER), and incremental net benefit (INB). Of the three, the ICER method has long been the standard in the assessment of the cost-effectiveness analysis of a new treatment. However, due to concerns with interpretability and statistical inference inherent to the ICER statistic and its confidence intervals, authors have suggested the use of incremental net benefit (INB) approach as an alternative. The INB can be expressed either in units of effectiveness or costs. When analyzing data from a clinical trial, expressing incremental net benefit in units of cost allows the investigator to examine all three approaches in a single graph, complete with the corresponding statistical inferences. Furthermore, if costs and effectiveness are not censored, this can be achieved using common statistical procedures. The standard INB analysis assumes that the willingness-to-accept (WTA) compensation for the loss of a unit of health benefit (at some cost saving) is the same as the willingness-to-pay (WTP) for it. Theoretical and empirical evidence suggest, however, that in health care the WTA is about twice the WTP. In this thesis we show that the method of INB analysis can be adapted to capture the WTA vs WTP disparity. Using the Bayesian theory, statistical procedures are provided for the cost-effectiveness analysis in the comparison of two arms of a randomized clinical trial that allows WTA and WTP to have different values. An example that adjusts the disparity between WT A and WTP is provided.

abstract: Thesis

abstract: Master of Science (MS)


title: Carbohydrate Distribution Pattern in Drosophila Melanogaster Embryos as Surveyed with a Battery of Lectins

title: Lectin Binding Pattern in D. Melanogaster Embryos

contributor:
Jacobs, J. R.
Biology

subject:
lectin
drosophila melanogaster
drosophila
melanogaster
carbohydrate
embryo

abstract:
Thesis
Master of Science (MS)


title: FCL: A FORMAL LANGUAGE FOR WRITING CONTRACTS

contributor:
Farmer, William
Computing and Software

subject:
contracts
formal languages
simple type theory
observables
deontic logic
conditional agreements
temporally based conditions

abstract:
Contracts are legally enforceable agreements between two or more parties. The agreements can contain temporally based conditions, such as actions taken by the contract parties or events that happen, that trigger changes to the state of the contract when the conditions become true. Since the structure of these conditions can be very complex, it can be difficult to write contracts in a natural language in a clear and unambiguous way. A better approach is to have a formal language with a precise semantics to represent contracts. Contracts expressed in such a language have a mathematically precise meaning and can be written, analyzed, and manipulated by software.
This thesis presents FCL, a formal language with a precise semantics for writing general contracts that may depend on temporally based conditions. Motivated by carefully selected examples of contracts, we derive a set of desirable requirements that a formal language of contracts should support. Based on the requirements, we clearly de ne the notion of contract and address what it means to fulfill or breach a contract. We present the formal syntax and semantics of FCL. We also successfully formalize different kinds of contracts in FCL and develop a reasoning system for FCL.

abstract: Thesis

abstract: Doctor of Philosophy (PhD)


title: Long and Short Term Regulation of Food Intake in the American Cockroach, Periplaneta americana (L.) (Orthoptera: Blattidae)

contributor:
Rollo, C. D.
Biology

subject: cockroach food consume intake

abstract: Cockroaches apparently select balanced diets using simple. but robust rules (Geissler & Rollo 1987). These rules are general enough to deal with a complex habitat yet sufficiently specific to contribute a balanced diet, thus leading to the successful maintenance of fitness. Both internal and external stimuli are integrated to elicit the appropriate responses. Feedback information concerning nutritional status may be short-term (e.g. immediate physiological state or sensory input) or long-term (e.g. storage reserves. hormones or learning) so that both coarse and fine-tuning mechanisms are involved in the choice of nutritious and non-toxic foods. The insects' ability to evaluate palatability (scent and taste cues) and nutritional value are essential aspects of the decision-making process. This study investigated the general mechanisms governing changes in preferences with respect to tradeoffs between short and long-term stimuli. On a short-term scale, animals should prefer foods that present immediate positive stimuli according to their innate disposition. However, if a food does not meet long-term physiological needs. the animal should develop an aversion and learning may override a decision based upon a short-term stimulus, or alter innate preferences entirely. The experimental protocol involved measuring amounts and time spent eating. Where appropriate, these values were related to female reproductive productivity to show the link between nutrition and reproductive capacity (fitness). Investigations demonstrated the ability of cockroaches to use coarse controls to compensate for long term general starvation as well as specifically depleted nutrients such as carbohydrates and protein. Cockroaches also showed discrimination between the quality of carbohydrate diets. The ranking of palatability among foods was not a fixed attribute but varied relative to the items available. With large nutritional imbalances that required time to correct, dietary management was less discriminatory with respect to food quality and was largely concerned with increased quantity. Relatively well nourished animals showed much greater selectivity with regard to quality. Thus, the coarse and fine-tuned control systems stressed different strategic tactics. Reproductive success was linked to responses to malnourishment. Reproductive output was increased even over control levels when animals compensated for energy depletion by switching to alternate resources. This contradicted the prediction of maximization of reproductive output (fitness) by maximization of energy intake from optimality theory. The results were interpreted with respect to optimal foraging theory, the currently accepted paradigm for ecological feeding relations. The results not only conflicted with the predictions of optimal foraging theory in most respects, they suggest a completely different paradigm that is incompatible with a hypothesis of maximization of net energy gain. Instead. cockroaches appear to regulate feeding with respect to evolutionarily determined set points related to innate growth and production rates. Moreover, the criteria for decisions are a multiplicity of nutritional requirements, not simply energy, as proposed by optimal foraging theory. Some of the decisions made with respect to nutritional balancing result from direct response to external or internal stimuli, and others are a learned association between long-term benefits and correlated sensory cues.

abstract: Thesis

abstract: Master of Science (MS)


title: Transient Receptor Potential Protein (Trp) mRNA Expression in Rat Substantia Nigra

contributor:
Grover, Ashok
Biology

subject: receptor protein mRNA rat

abstract: Substantia nigra neurons produce dopamine in response to cholinergic stimuli that may involve receptor operated Ca²⁺ -entry that has been associated with the transient receptor potential (Trp) proteins. There were 6 Trp isoforms reported when I started this work. I set out to determine which isoforms of Trp mRNA were expressed in the substantia nigra using the whole brain for comparison. I initially used RT-PCR to determine the Trp mRNA expression. Subsequently, I used competitive RT-PCR for quantifying the major isoforms. Finally, I confirmed my results by Co-RT-PCR of the major isoforms. Trp3 and Trp6 were found to be the predominant forms expressed in the substantia nigra and whole brain, while the levels of Trps 1, 2, 4 and 5 were very low in both. Estimation of mRNA levels using competitive RT-PCR showed that the Trp6 mRNA levels in substantia nigra and the whole brain were similar while those for Trp3 were significantly lower in the substantia nigra than in the while brain. Thus substantia nigra differs from the whole brain in its Trp expression. Properties of Trps 3 and 6 are not fully known. Trp3 is regulated by IP₃-receptor activation but both Trp 3 and 6 can be activated by diacylglycerol. How this relates to the signal transduction events in substantia nigra remains to be determined.

abstract: Thesis

abstract: Master of Science (MS)


title: WHOse Health?: A Critical Analysis of the World Health Organization Definition of Health

title: Whose Health?: A Critique of WHO's Definition of Health

contributor:
Boetzkes, Elisabeth
Philosophy

subject: health definition WHO world analysis

abstract: This thesis offers a critical analysis of the World Health Organization (WHO) definition of health. Feminist epistemology is used to reveal how health and disease are dualistically constructed. Beyond serving as designations for different physiological statuses, these terms are of metaphorical significance, such that individuals affiliated with 'health' are socio-economically, politically and effectively morally preferred over those associated with 'disease'. Popular and immunological conceptions of 'disease' provide justifications for maintaining the oppression of the latter identity. Given WHO's history of prioritizing disease control over primary health care and the consequent implementation of both objectives within a disease-oriented framework, WHO's definition of health is in danger of supporting the health/disease dualism, which in turn jeopardizes the organization's mandate to treat its members formally and substantively equally, and to provide 'health for all'.

abstract: Thesis

abstract: Master of Arts (MA)


title: Light Microscopy, Electron Microscopy and Elemental Analyses of Cucurbita Maxima and Cucurbita Andreana Pollen

title: Structural Studies and Elemental Analyses of Cucurbita Pollen

contributor:
Lott, J. N. A.
Biology

subject: cucurbita electron microscopy light element analysis

abstract: Cucurbita maxima and Cucurbita andreana are closely related species; however, the calcium phytate levels of the Cucurbita seeds differ significantly. Hybridization of the two Cucurbita species is difficult to achieve. The aim of my research was to extensively study the structure of C. maxima and C. andreana pollen and determine whether the pollen of the species differed in their elemental content. This thesis entails the most comprehensive study of the structure, chemical composition and elemental content of the pollen from a dicot plant. This study of Cucurbita pollen required the use of various light microscopy, electron microscopy and elemental analyses techniques. Histochemical stains revealed information about the chemical structure of pollen and pollen storage reserves. The primary storage reserve of Cucurbita pollen consisted of starch. Additional storage reserves consisted of protein, small amounts of lipids and mineral reserves. Additional studies of the external and internal structures of the Cucurbita pollen were carried out with transmission electron microscopy and scanning electron microscopy respectively. Preparation of sections of pollen for electron microscopy was difficult. Sectioning problems arose due to the thick pollen wall, the density of pollen cytoplasm, and inadequate infiltration of epoxy resin into pollen during processing. C. maxima and C. andreana pollen grains were fixed anhydrously because water-soluble phytates such as potassium phytate are extracted by aqueous fixatives . The cytoplasm of both species contained many small electron-dense globoid particles. Globoid particles were observed in sections of pollen and in samples of ground pollen. Elemental analysis of globoid particles from Cucurbita pollen was carried out, for the first time, with energy dispersive X-ray (EDX) analysis. EDX analysis spectra of globoid particles from C. maxima and C. andreana pollen were compared. Spectra of Cucurbita pollen globoid particles were similar to spectra from phytate deposits in seeds. EDX analysis of globoid particles of pollen revealed that the globoid particles contained mainly Mg, P and K. EDX analysis spectra of globoid particles of sections of Cucurbita pollen revealed that water soluble materials, likely K phytate, were extracted from sections cut onto water-filled microtome boats. Pollen sections cut onto absolute ethanol-filled microtome boats experienced less extraction of water soluble materials from the sections. Neutron activation analysis of whole pollen grains revealed that the individual concentrations of Mg, K, Ca and P were not significantly different from species to species. The elemental analyses results strongly suggest that phytate is stored in globoid particles of Cucurbita pollen.

abstract: Thesis

abstract: Master of Science (MS)


title: Drought Stress Responses in a Populus Hybrid Complex in Southern Alberta

contributor:
Coxson, D. S.
Lott, J. N. A.
Biology

subject: drought stress response Alberta hybrid populus

abstract: Stomatal response of narrow leaf poplar (P. angustifolia; (PA)), balsam poplar (P. balsamifera; (PB)), cottonwood (P. deltoides; (PD)), and a P. angustifolia X P. balsamifera hybrid (PX) was studied in the field and in controlled environments. Mild water stress was occurring in both field studies, as evidenced by pre-dawn Ψ values of no less than -0.3 MPa; controlled experiments were more severe, with values dropping below -1.0 MPa. Stomatal conductance patterns differed for each species, and suggest that in terms of tolerating drought stress, PX > PA > PB > PD. These patterns were significantly influenced by microclimate conditions; severe conditions caused partial or complete stomatal closure, even in the presence of low water stress. Preconditioning plants through brief, repeated exposure to water stress resulted in stomatal closure at approximately -1.0 MPa, a higher level Ψ than is otherwise indicated for members of the genus Populus. It may thus be a valuable component of drought resistance for these species. Dieback studies indicated dissimilar patterns of dieback between PA and PB; PA experienced dieback on a large number of small branches while that of PB occurred on a small number of main branches. These results suggests that the drought stress response may differ between the two species, and may further indicate that the pattern of dieback is reflective of the physiological response to drought stress.

abstract: Thesis

abstract: Master of Science (MS)


title: The In Vitro Degradation of [^14 C]-Malathion and [^14 C]-Malaoxon in Resistant and Susceptible Strains of Drosophila Melanogaster

title: Malathion Resistance in Drosophila Melanogaster

contributor:
Morton, R. A.
Biology

subject:
drosophila melanogaster
drosophila
in vitro
malathion
malaoxon

abstract:
Malathion-resistance in Drosophila Melanogster was studied in susceptible laboratory strains (CS and OR), a heterogeneous intermediate-resistant strain (C1-39), and a more resistant, artificially selected (with malathion). strain (MH19) by comparing the in vitro metabolism of [¹⁴c]-malathion and [¹⁴c]-malaoxon in crude enzyme preparations made from adult flies.
Extracts from all strains were found to contain two enzymatic activities that metabolized malathion and/or malaoxon. One activity degraded malathion to its α- and β-monocarboxylic acids and was designated as malathion-carboxylesterase activity (ME-activity). ME-activity was progressively lost in CS-extracts during reaction with [¹⁴c]-malathion due to inhibition of the enzyme(s) by a tightly bound [¹⁴c]-labeled molecule (not identified) that could not be removed by chromatography on Sephadex G-25. ME-activity, based on initial (0-1 min) rates with or without metyrapone present was similar in all strains and furthermore, the carboxylesterase inhibitors TPP and DEF did not synergize malathion toxicity in either resistant or susceptible strains. It was concluded that carboxylesterase-mediated degradation of malathion was not a factor in the resistance of the C1-39 and MH19 strains. A second enzyme system, microsomal mixed-function oxidases (MFO), converted malathion to malaoxon (activation) and degraded malaoxon to at least two products that were tentatively identified (malaoxon α-and β-monoacids and demethyl-malaoxon). The rate of conversion of malathion to malaoxon was highest in crude extracts of the most resistant MH19 flies, intermediate in C1-39 and could not be detected in the susceptible CS flies while the rate of malaoxon degradation was similar between MH19 and C1-39, but higher than that in the susceptible OR flies. Furthermore, malaoxon (but not malathion) toxicity was most strongly synergized by the MFO-inhibitor MTP in the more resistant strains (MH19 and C1-39) . These results were used along with a previous result that MH19 strain possesses a less sensitive form of the target enzyme, acetylcholinesterase (R.A. Morton, personal communication), to propose a biochemical mechanism that accounts for the increased malathion-resistance of the C1-39 and MH19 strains.

abstract: Thesis

abstract: Master of Science (MS)


title: Phenotypic Plasticity of Carbon Acquisition and Allocation in Rapid Cycling Brassica rapa L. and the Androdioecious Species Mercurialis annua L. s. l. in Response to Light Quality

title: Phenotype Plasticity of Carbon Acquisition and Allocation

contributor:
Dudley, S. A.
Biology

subject: phenotype plasticity carbon Brassica Mercurialis light

abstract:
Thesis
Master of Science (MS)


title: Digital Image Analysis of Vertebral Bodies from Computed Radiography Images

contributor:
Luo, Zhi-quan
Nahmias, Claude
Electrical and Computer Engineering

subject: digital verebral radiography computed

abstract: Vertebral body deformities resulting from osteoporosis are commonly observed in lateral spine radiographs. Clinically, these deformities are judged rather subjectively, both in their classification and in the assessment of the extent of deformity. In order to objectify clinical observation, morphometric measurements are a means for classifying and quantifying the presence and extent of vertebral body deformities. Drawing on the morphometric systems of Minne et al. (1988) and Smith-Bindman et al. (1991), we propose a total vertebral deformity index (TVDI) which provides a single, clinically meaningful number indicative of the extent of deformity in a vertebral column. Each of the three deformity types (wedge, biconcave, and compression) is classified and measured independently, using ratios relating measurements of anterior, mid, and posterior heights, and inferior width. Expected measurements are determined for each vertebral level, and the sum of the deviations from the measured to the expected values generates a vertebral deformity index. This proposed index addresses issues in vertebral body morphometry, including vertebral level specificity, body size differences, multiple compression effects, and multiple deformity types. Inherent in the practical use of morphometric quantification are issues of accuracy and reproducibility of the measurements, .and of the time involved in making these measurements. Digital image processing algorithms are developed to attempt automated detection and measurement of the vertebral body boundary, using Computed Radiography images of the lateral spine. Three different methods yield varying results. In addition to the characteristics of lateral spine images (such as high intensity vertebral ridges) which are used to advantage by the algorithms, all three methods must deal with problematic anatomical characteristics such as the presence of the high intensity ribs and ilium. The first method is a series of image enhancement and thresholding steps applied to each vertebra, in order to delineate its vertebral boundary in a hi-level image. This method is fairly effective, but suffers from its dependence on thresholding. The second method uses the cross-correlation measure to detect the vertebrae, given a starting vertebra, and then uses edge-gradient tracking to trace the vertebral boundary. Results of this method are promising. There remains a weakness in the cross-correlation detector, which fails to accurately locate vertebrae that are further away from the starting vertebra. The third method is an active contouring technique called Snakes, in which the vertebral boundary is represented by a deformable spline which seeks to minimize an energy functional consisting of curvature, continuity, and image energy terms. Present results display minimal convergence onto the vertebral boundaries. Future work should refine the customization of the energy functional to produce better results. At present, all three methods require some kind of user interaction. Further development may prove fruitful in reducing user interaction to achieve a truly automated system.

abstract: Thesis

abstract: Master of Engineering (ME)


title: Na^+ and Cl^- Reabsorption Studies in the Rainbow Trout (Oncorhynchus mykiss) Urinary Bladder Sac

title: Na^+ and Cl^- Reabsorption Studies in the Rainbow Trout Urinary Bladder Sac

contributor:
Wood, C. M.
Biology

subject:
reabsorb
rainbow trout
bladder
sodium

abstract:
Thesis
Master of Science (MS)


title: Changes in the Element Composition of Globoids in Wheat Grains (Triticum aestivum L. cv. A. C. Reed and Celtic) During Seed Set and Early Seedling Growth

title: Globoid Composition During Seed Set and Seedling Growth

contributor:
Lott, John
Biology

subject: globoid wheat grain element composition

abstract: In wheat grains, mineral nutrients are stored in spherical particles called globoids. Globoids are located within the protein bodies of cells from the aleurone layer, scutellum and embryonic axis of the wheat grain. Composed of phytate, globoids contain an essential source of myo-inositol, P, K, Mg, Ca, Mn, Fe and Zn which are used by the growing seedling during early seedling growth. Changes to the element composition within the globoids from the aleurone, scutellum and embryo axis, during seed set and early seedling growth were examined in two cultivars of wheat through the use of energy dispersive X-ray analysis. During seed set and early seedling growth the composition of the globoids within all tissues changed. In each of the tissues in both cultivars the P levels decreased during seed set and remained relatively constant during early seedling growth. K levels increased during seed set and decreased during early seedling growth. Mg and Ca levels generally decreased during seed set and increased during early seedling growth. Mn and Zn were detected only within globoids within the embryonic axis and no changes were noted for these two elements. Energy dispersive X-ray analysis showed that A.C. Reed and Celtic grains both followed the same general trends during seed set and seedling growth indicating that the differing protein content of the two cultivars had little effect on the timing of mineral nutrient accumulation and utilization within the globoids. Atomic absorption analysis of whole grain tissue for P, K, Mg and Ca revealed that Celtic grains had higher concentrations of P and K while being grown in identical conditions to that of A.C. Reed grains. These results indicate that mineral nutrient levels within the grain seem to be influenced by the cultivar, and possibly the protein content of the particular cultivar.

abstract: Thesis

abstract: Master of Science (MS)


title: Cellular Mechanisms of KCl Reabsorption in the Lower Malpighian Tubule of Rhodnius Prolixus

contributor:
O'Donnell, M. J.
Biology

subject: rhodnius KCl malphigian

abstract:
Thesis
Master of Science (MS)


title: Light, Electron Microscopic and Element Analysis Studies of Capsicum Annuum Seeds

title: Structure and Composition of Capsicum Annuum Seeds

subject:
light
electron
electron microscopy
capiscum
capiscum annuum
element

abstract:
Thesis
Master of Science (MS)


title: Mixed Function Oxidase Activity and Malathion Resistance in a Selected Strain of Drosophila Melanogaster

subject:
drosophila
drosophila melanogaster
oxidase
malathion

abstract: The genetic factors controlling Mixed Function Oxidase (MFO) Activity and malathion resistance was studied in the larva and the adult of a malathion resistant strain of Drosophila melanogaster. In addition, the developmental expression and tissue localization of high MFO activity was characterized in the larva and the adult. Microsomal extracts from a strain with a resistant second chromosome were found to have increased amounts of protein with a relative molecular mass of 52 kD, while a strain with a resistant third chromosome was found to have increased amounts of proteins with relative molecular masses of 51 and 55 kD in the microsomal extract. MFO activity associated with a strain with a resistant second chromosome was found to be most concentrated in the intestine and abdominal wall of the imago, while found primarily in the malpigian tubules and the fat body of the larva. The mapping of genes on the second chromosome associated with larval resistance to malathion suggested two loci, a major resistance gene at 2-64 cM and a second minor resistance gene. The mapping of genes on the second chromosome associated with adult resistance again suggested two loci, one at 2-64 cM and a second just to the left of the marker black (48.5 cM). The mapping of genes on the second chromosome associated with high PNA demethylase activity (an MFO activity) in the adult suggested a locus at 2-64 cM and a second between 54.5 and 60.0 cM. The locus at 2-64 cM and a third locus between 48.5 and 51 cM was found to be associated with high 7-EC hydroxylase activity ( a second MFO activity) in the adult.

abstract: Thesis

abstract: Master of Science (MS)


title: Cytological Characterization of Hybrid Male Sterility Among Sibling Species of the Drosophila Melanogaster Complex

title: Characterization of Hybrid Male Sterility in Drosophila

contributor:
Singh, R. S.
Biology

subject:
hubrid
sterility
sibling
species
drosophila
drosophila melanogaster

abstract:
Thesis
Master of Science (MS)