ERA

Theses and Dissertations

This collection contains theses and dissertations of graduate students of the University of Alberta submitted prior to Spring 2009. Past graduates who wish to have their thesis or dissertation added to this collection can contact the ERA Mediated HelpDesk at erahelp@ualberta.ca. Please note: current students needing to deposit their thesis or dissertation for review as required for convocation must follow the steps outlined here.
Items in this Collection
  1. A solution to the Crow-Omaha problem and its implications for future research into social organization

    Title: A solution to the Crow-Omaha problem and its implications for future research into social organization
    Creator: Lathrop, Gregory Mark
    Description: This thesis presents a solution to the Crow-Omaha problem as originally defined by Levi-Strauss (1966, 1969). By beginning with a fixed set of demographic conditions and a given form of Crow-Omaha marriage rules, and viewing the clan structure as being in a non-equilibrium state, it is possible to overcome the demographic problems which hampered Levi-Strauss' analysis of the Crow-Omaha systems. In particular, it is shown that in a finite and endogamous population demographic variation under Crow-Omaha exchange causes an imbalance in the size of clans and an actual reduction in clan numbers culminating in the convergence of the exchange system to a minimal structure with mechanical properties determined solely by the marriage rules. This result is independent of the initial pattern of exchange assumed in the analysis, or the particular demographic history of the population, the problems which originally impeded Levi-Strauss. The properties of the minimal structure can be used to explain several other features of Crow-Omaha societies, most importantly patterns of migration and clan fissioning. The results obtained here bear on the general theoretical question of the relationship between demographic and social variables, and suggest a direction for future research into problems of social organization. The analysis presented in this thesis is framed within the context of Navajo ethnography. Navajo social organization is not usually classified as Crow-Omaha because the kinship system is Iroquoian and clans are not corporate units. From the viewpoint of exchange, however, the Navajo system may actually be thought of as an ideal Crow-Omaha type, since the clans function almost exclusively in the regulation of marriage. By using the Navajo example in an initial analysis, any possible deviations from Levi-Strauss' model caused by clan hierarchization can be avoided. The effects of the convergence of the exchange structure within Navajo communities is examined by a comparison between ethnographic data and the results of computer simulations. A statistical tendency for marriage into one of the grandfathers' clans and the pattern of migration into Navajo communities are explained on the basis of the properties of the minimal exchange structure.
    Subjects: Crow Indians--Kinship, Omaha Indians--Kinship, Navajo Indians--Kinship, Crow Indians--Social networks, Omaha Indians--Social networks, Navajo Indians--Social networks
  2. Patterns in the Scattering of Remains due to Scavenger Activity

    Title: Patterns in the Scattering of Remains due to Scavenger Activity
    Creator: Kjorlien, Yvonne
    Description: In archaeological and forensic contexts, human remains are frequently found scattered. The recovery of these remains is often variable and inconsistent. There has been little research specifically to improve the methods applied to these contexts. This study attempted to discover patterns in the scattering of remains due to scavenger activity. Twelve human analogues (pigs) were deposited in wooded and open grassland environments; half of these were dressed in human clothing. For 103 days, each pig was monitored regularly. Data on the time and direction of movement of the carcass or any part thereof were collected and analysed for potential patterns. The results provide evidence for patterns in where, when and what is scattered due to scavenging activity. Near daily observations may be the key for discovering these patterns. Determining what influences this pattern development and exploring methods that specifically illustrate these patterns should be primary goals in future research.
    Subjects: scattered remains, taphonomy, physical anthropology
  3. A Framework for Improving the Productivity of Operational Preventive Maintenance Activities for Wastewater Collection System

    Title: A Framework for Improving the Productivity of Operational Preventive Maintenance Activities for Wastewater Collection System
    Creator: Zaman, Hamid U
    Description: Operational maintenance of the wastewater collection system is an important part of urban infrastructure management. It involves various activities, such as visual inspection, low-pressure flushing (LPF), high-pressure flushing (HPF), catch basin cleaning, and hydro-mechanized cleaning. Large cities require significant budget and resources to perform the necessary cleaning activities at various locations around the city at regular intervals. For instance, the collection system in Edmonton, Canada, comprises over 5,500 km of sewer pipes, and as of 2014 there are over 1,400 prescheduled HPF locations. However, planning and scheduling these activities can be challenging because of the wide variation of actual on-site flushing duration, which depends on a number of factors such as length and diameter of the pipes, frequency of flushing, structural condition, age, and season. Moreover, travelling between these locations results in a large amount of unproductive time. Reviews of the literature and of current industry practice reveal that the existing models and algorithms do not specifically address these issues. This research, therefore, develops a framework for improving the productivity of these activities by optimizing operational maintenance schedule. The research consists of two primary modules: (i) developing a forecasting model to estimate the on-site duration of activities, and (ii) developing an optimization algorithm to maximize productivity. The models are developed and tested using historical data of HPF activity from the Drainage Operations group at the City of Edmonton. The forecasting model captures the majority of the variations in on-site flushing duration and provides useful insight into the factors affecting on-site productivity. For optimization, this research formulates the drainage operations scheduling problem (DOSP) as a special class of the stochastic and capacitated vehicle routing problem (VRP), where the objective is to maximize value-added on-site flushing time while minimizing travel. Alongside existing algorithms (such as integer programming, genetic algorithm), a heuristic algorithm is developed to meet the specific needs of this complex combinatorial problem. The proposed optimization algorithm is tested and compared with other algorithms by simulating a monthly HPF schedule. The results show that accurate estimation of on-site duration, coupled with schedule optimization can improve daily productivity by a considerable margin. The outcome of this research makes significant academic, economic, and environmental contributions by proposing a systematic approach to planning and scheduling operational maintenance for wastewater collection systems.
    Subjects: Wastewater Collection System, Schedule Optimization, Optimization Algorithms, Productivity Improvement, Drainage Operations
  4. Addressing Pre- and Post-Deployment Support of Wireless Sensor Networks

    Title: Addressing Pre- and Post-Deployment Support of Wireless Sensor Networks
    Creator: Ganev, Veselin S
    Description: In this work we address the challenges arising when developing, testing and deploying software for Wireless Sensor Networks. We investigate both pre-deployment software design, as well as efficient post-deployment updates. We present a combined pre-deployment framework that simulates the network as it would be deployed to help in the testing, evaluation and fine-tuning of the system. Additionally, we address the need for post-deployment remote updates of the running code in an efficient and reliable manner. We also describe a real-world application that has motivated our work: the Smart Condo™ project, a system for monitoring patient activities in assisted living environments.
    Subjects: Embedded software, Simulation, MQTT, Smart Condo, Energy efficiency, Code updates, Wireless Sensor Networks, Assisted living technology
  5. Inactivation of Saccharomyces cerevisiae and Candida humilis in Potassium Phosphate Buffer by Pulsed Electric Fields

    Title: Inactivation of Saccharomyces cerevisiae and Candida humilis in Potassium Phosphate Buffer by Pulsed Electric Fields
    Creator: Ou, Qixing
    Description: Pulsed electric field (PEF) is a promising athermal food preservation technology, having the potential to provide a better balance between food safety and food quality. But the high cost of PEF treatment has limited the commercial application of this technology. The aim of this MSc thesis research was to determine the effect of different parameters on the efficacy of PEF. A custom-built PEF system with a gap distance of approximately 14 µm between two parallel plate electrodes was used to provide a homogeneous electric field and temperature distribution. Saccharomyces cerevisiae and Candida humilis were used as model microorganisms, and potassium phosphate buffer was used as a model fluid. Viable cell enumeration after PEF treatments in the presence or absence of 100 µM of propidium iodide was used to distinguish reversible and irreversible electroporation. The electrical parameters governing the efficacy of PEF include pulse shape, pulse width, pulse frequency, electric field strength, and specific energy input. Experiments were designed in a systematic way with the variation of field strength from 18 to 71 kV/cm, specific energy input from 8 to 46 kJ/kg, pulse width from 86 ns to 4 µs, pulse frequency of 5 and 10 kHz, and pulse wave shapes of unipolar square pulse and bipolar exponential pulse. Results demonstrated that the specific energy input had the highest correlation (r2=0.84) with the lethal effect of PEF, followed by field strength (r2=0.10) and pulse width (r2=0.003). In order to avoid electrolysis during PEF treatments, alumina (Al2O3) covered gold electrodes were employed. Results indicate that conduction current was not necessary for electroporating and inactivating cells by PEF, but electrolysis had a strong synergy with PEF. The composition of fluid has the ability to greatly influence the efficacy of PEF.
    Subjects: PEF, Saccharomyces cerevisiae, Yeast, Propidium iodide, Electrolysis, Conduction Current, Energy Input, Efficacy
  6. On The General Theory of Optional Stochastic Processes and Financial Markets Modeling

    Title: On The General Theory of Optional Stochastic Processes and Financial Markets Modeling
    Creator: Abdelghani, Mohamed Nabeel
    Description: Optional processes including optional semimartingales are not necessarily right or left continuous. However, optional semimartingales have right and left limits. Moreover, optional processes may exist on ”un-usual” stochastic basis where the increasing information-filtrations are not complete or right continuous. Elements of the stochastic calculus of optional processes is reviewed. The linear stochastic differential equations with respect to optional semimartingales is solved. A solution of the nonhomogeneous linear stochastic differential equation and a proof of Gronwall inequality are given in this framework. Existence and uniqueness of solutions of stochastic equations of optional semimartingales under monotonicity condition is derived. Comparison theorem of solutions of stochastic equations of optional semimartingale under Yamada conditions is presented with a useful application to mathematical finance. Furthermore, a financial market model based on optional semimartingales is proposed and a method for finding local martingale deflators is given. Several examples of financial applications are given: a laglad jump diffusion model, Optimal debit repayment and a defaultable bond with a stock portfolio. Also, a pricing and hedging theory of a contingent claims for these markets is treated with optional semimartingale calculus. Finally, a new theory of defaultable markets on ”un-usual” probability spaces is presented. In this theory, default times are treated as stopping times in the broad sense where no enlargement of filtration and invariance principles are required. However, default process, in this context, become optional processes of finite variation and defaultable cash-flows become optional positive semimartingales.
    Subjects: Monotonicity, Martingale Deflators, Stochastic Basis, Optional Martingales, Stochastic Equations, Optional Processes, Comparison Theorem, Default Time, Gronwall Lemma, Optional Semimartingales
  7. A re-assessment of the genus Mosasaurus (Squamata: Mosasauridae)

    Title: A re-assessment of the genus Mosasaurus (Squamata: Mosasauridae)
    Creator: Street, Hallie P.
    Description: Mosasauridae is a lineage of extinct marine squamates that inhabited the world’s oceans during the Late Cretaceous (100-66 Ma). The name Mosasaurus was given to the first described specimen, which was a fossil discovered in Maastricht, the Netherlands, during the 1770s. Naturalists of the time did not provide a precise diagnosis when describing or naming the specimen, and so the concept of the taxon remained poorly delineated. As has been the case for many of the early generic names erected for fossil reptiles (e.g. Iguanodon, Ichthyosaurus, Plesiosaurus), this lack of a precise diagnosis allowed Mosasaurus to become a wastebasket taxon, with dozens of species assigned to it over the past two centuries. Some paleontologists made efforts to more precisely diagnose Mosasaurus over the past fifty years, but the specimens these diagnoses were based on further confused what was being defined. The first goal of this study is to emend the diagnoses of Mosasaurus and its type species M. hoffmannii Mantell 1829 in order to develop a clear-cut characterization of these taxa. Provided with a precise diagnosis of the genus, the skeletal morphology of 12 potentially valid species is compared to that of M. hoffmannii in order to determine their agreement with the generic paradigm. The findings of these comparisons informed the choice of taxa included in the phylogenetic analyses. To date, no phylogenetic analysis of Mosasauridae has included more than three or four species of Mosasaurus, and this study rectifies that. The phylogenetic analysis, which was based on a taxon list including only those taxa determined to be both valid and distinct by the morphological comparison, found Mosasaurus to be composed of only four species and part of a discrete clade of closely related genera that differ from the rest of the Mosasaurinae. The morphological comparisons and hypothesis of relationships produced by the phylogenetic analyses are combined to develop the ultimate goal of this study, which is a complete systematic revision of Mosasaurus. The species that disagree with the generic paradigm are reassigned to other genera or serve as the basis for new genera within the clade Mosasaurini. After nearly two centuries, M. hoffmannii is diagnosed based on the morphology exhibited by the holotype specimen, and the diversity of taxa related to Mosasaurus is more clearly understood.
    Subjects: Mosasaurinae, description, taxonomy, Mosasaurus, systematics
  8. Impacts of a six year old pipeline right of way on Halimolobos virgata (Nutt.) O.E. Schulz (slender mouse ear cress), native dry mixedgrass prairie uplands, and wetlands

    Title: Impacts of a six year old pipeline right of way on Halimolobos virgata (Nutt.) O.E. Schulz (slender mouse ear cress), native dry mixedgrass prairie uplands, and wetlands
    Creator: Low, Caitlin H.
    Description: Reclamation of native prairie ecosystems is of growing importance as they continue to be impacted by anthropogenic disturbances. Since European settlement, Alberta grasslands have declined by 61 %. Grasslands are agriculturally important, act as a carbon sink, and many species depend upon them. In Alberta, 77 % of flora and fauna species at risk depend upon or are endemic to native grasslands. Environment Canada recommends a 300 m set back between at risk species, their critical habitat, and pipeline disturbances. Pipeline disturbances can fragment habitat, introduce non native species, impact the soil through admixing and compaction, and alter hydrologic regimes. The impact of pipeline disturbance on at risk plant species and critical habitat is not widely documented or understood. The objective of this research was to assess the impact of a six year old pipeline right of way on the rare species Halimolobos virgata and native dry mixedgrass prairie upland and wetland ecosystems. Halimolobos virgata surveys were conducted at two native prairie sites with historic populations. Upland vegetation assessments were conducted at ten locations relative to the pipeline right of way at six native prairie sites. Wetland vegetation assessments were conducted at eight sites on and nine sites off the right of way in native prairie. The research was conducted in southern Alberta, 150 km north of Medicine Hat, over two field seasons in 2014 and 2015. Halimolobos virgata increased in population size over two field seasons. It appeared to select microhabitat sites with limited competition from other species and a high amount of litter cover. Halimolobos virgata was found on the pipeline trench in the last year of the study. Impacts to the plant community were greatest over highest disturbance zones of the right of way, the trench and work areas. Species richness and diversity were significantly lower in these areas relative to other right of way zones and undisturbed prairie. The trench had greatest bare ground and least live species cover. Little variability was found in wetlands on and off the right of way. Community composition, species richness, diversity, similarity, and ground cover were consistent across all sites. After seven growing seasons, the impacts of disturbances caused by pipeline right of ways have begun to lessen on the plant communities of uplands and wetlands. Native species were dominant, and non native species did not appear to be dominating any areas of the right of way. Halimolobos virgata does not appear to be negatively impacted by the right of way, thus the 300 m set back is not required, provided similar construction methods are used. The set back of 30 m between Halimolobos virgata and pipeline construction that was used by TransCanada is sufficient to protect existing populations and associated habitat.
    Subjects: dry mixedgrass prairie, pipelines, disturbance, reclamation, Halimolobos virgata, rare species, wetlands
  9. Purinergic and Glial Signalling in the Hypoxic Ventilatory Response

    Title: Purinergic and Glial Signalling in the Hypoxic Ventilatory Response
    Creator: Rajani, Vishaal
    Description: The hypoxic ventilatory response comprises of an initial increase in ventilation, followed by a secondary depression that can be life threatening in premature infants. During hypoxia, ATP is released in the ventrolateral medulla, where it is suggested to attenuate the secondary hypoxic respiratory depression. The objective of my thesis is to explore the contribution of ATP to the hypoxic ventilatory response, specifically exploring the (i) cell-types, (ii) site, (iii) receptor subtype and (iv) signalling pathways that underlie the actions of ATP. I first tested the contribution of glia. I disrupted vesicular release proteins that are necessary for gliotransmission via bilateral injection of an adenovirus controlling glial-specific expression of tetanus light chain protein (TeLC) into the ventral respiratory column (VRC). TeLC caused a decrease in ventilation during the initial phase I component of hypoxic ventilatory response when ventilation increases quickly, and also during the phase II component after ventilation has plateaued after the secondary depression. I next tested which receptor subtype is responsible for attenuating the hypoxic ventilatory depression and where in the VRC this effect was mediated. In adult rats, in vivo unilateral injection of P2Y1 receptor agonist into the preBötzinger Complex (preBötC, central site of inspiratory rhythm generation) caused an increase in respiratory frequency, while in vivo injection of P2Y1 receptor antagonist into the same site increased in the secondary hypoxic respiratory depression. In vivo injection of adenosine, the end product of ATP breakdown, into the preBötC had no effect on ventilation. To explore signaling cascades underlying the excitatory effects of P2Y1 receptor activation in the preBötC, I tested the effect of selective pharmacological blockers on the P2Y1 receptor mediated frequency increase in the neonatal rhythmic slice preparation. Experiments revealed that the P2Y1 receptor mediated excitation is sensitive to calcium chelation, sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibition, antagonism of IP3 receptors, and protein kinase C (PKC) inhibition. Similar to the P2Y1 network response, I show that the ATP activation of cultured preBötC glia via intracellular Ca2+ increases are also sensitive to SERCA inhibition. These findings suggest that ATP, through a process that involves gliotransmission, acts via P2Y1 receptors in the preBötC to attenuate the secondary hypoxic respiratory depression in vivo, via signaling cascade that involves release of calcium from intracellular stores and PKC activation. This work provides in vivo verification of multiple hypotheses previously developed from in vitro preparations, and lays a foundation for future research in understanding the underlying mechanism of purinergic signalling and the contribution of glia to respiratory network modulation.
    Subjects: Astrocytes, preBötzinger Complex, Hypoxia, Hypoxic Ventilatory Response, ATP, P2Y1, Glia, Purinergic receptor
  10. Involvement of Gibberellin in growth and carbohydrate partitioning in developing pea (Pisum sativum L.) seeds

    Title: Involvement of Gibberellin in growth and carbohydrate partitioning in developing pea (Pisum sativum L.) seeds
    Creator: Waduthanthri, Kosala D
    Description: Gibberellins (GAs) are an important class of diterpenoid plant hormones that control various aspects of plant development including seed growth and development. The involvement of GAs during pea (Pisum sativum) seed development was studied by comparing GA deficient mutants; lh-2, lh-1, le-3, ls-1 and a transgenic GA-overexpressor line (TG1) with their respective isogenic or transgenic controls. lh-2 was the most severe GA biosynthesis mutant studied, with marked reduction in seed bioactive GA levels, reduced seed growth, and high seed abortion (Swain et al., 1993, Planta 191:482). Seed coats of lh-2 exhibited delayed hypodermal and reduced epidermal and ground parenchyma cell expansion compared to LH seed coats. lh-2 cotyledonary storage parenchyma cell expansion was also reduced compared to the LH line. With respect to photoassimilate partitioning, starch accumulation (8 to 12 days after anthesis; DAA) in the seed coat and mobilization of seed coat starch to the embryo (14 to 20 DAA), as well as starch accumulation in the cotyledons, were dramatically reduced in the lh-2 mutant compared to LH. The lh-2 mutation delayed the transition of the liquid endosperm from a high to low glucose to sucrose state, and prolonged the complete absorption of the endosperm by the developing embryo by four days compared to that of LH. The other three GA biosynthesis mutants (lh-1, le-3, and ls-1) showed less severe effects on seed growth and development, and seed coat cell expansion. However, starch accumulation in the seed coat was markedly lower in lh-1, le-3, and ls-1 than in their isogenic wild-type (from 8 to 12 DAA), and accumulation of starch in the embryo was delayed (14 to 20 DAA). The GA-overexpressor line TG1 constitutively expresses PsGA3ox1 (LE; a fully functional wild-type GA 3β-hydroxylase gene that encodes 3β-hydroxylase that converts GA20 to GA1) in a semi-dwarf lele pea line (‘Carneval’; le-1; single base-pair mutation in PsGA3ox1) (Reinecke et al., 2013, Plant Physiol 163:929). In the GA-overexpressor line TG1, enhanced hypodermal, epidermal, ground parenchyma and branched parenchyma cell expansion was observed in the seed coat compared to the transgenic control C1. Starch accumulation in the seed coat cells was greater at 10 DAA and mobilization of seed coat starch to the embryo was enhanced from 16 to 20 DAA in TG1 compared to the transgenic control line. The accelerated assimilate partitioning into the seed in TG1 was correlated with larger seed size at maturity. These data support that GAs regulate specific aspects of seed coat and embryo development, and as a result, can modify photoassimilate partitioning into the developing seed.
    Subjects: pea (Pisum sativum L.) seed growth, carbohydrate partitioning, cell expansion, Gibberellin