Graduate Theses & Dissertations


Stoichiometric food quality affects responses of Daphnia to predator-derived chemical cues
While both resource quality and predator-derived chemical cues can each have profound effects on zooplankton populations and their function in ecosystems, the strength and nature of their interactive effects remain unclear. We conducted laboratory experiments to evaluate how stoichiometric food quality (i.e., algal carbon (C):phosphorus (P) ratios) affects responses of the water flea, Daphnia pulicaria, to predator-derived chemical cues. We compared growth rates, body elemental content, metabolic rates, life history shifts, and survival of differentially P-nourished Daphnia in the presence and absence of chemical cues derived from fish predators. We found effects of predator cues and/or stoichiometric food quality on all measured traits of Daphnia. Exposure to fish cues led to reduced growth and increased metabolic rates, but had little effect on the elemental content of Daphnia. Elevated algal C:P ratios reduced growth and body %P, increased respiration, and increased body %C. Most of the effects of predator cues and algal C:P ratios of Daphnia were non-interactive. In contrast, the declines in daphnid survival and related population growth rates that arose because of poor food quality were amplified in the presence of predator-derived cues. Our results demonstrate that stoichiometric food quality interacts with anti-predator responses of Daphnia, but these effects are trait-dependent and appear connected to animal life-history evolution. Author Keywords: Daphnia, ecological stoichiometry, indirect predator effects, life history, phosphorus, predator-prey relationships
Statistical Analysis of the Hidden Patterns Found in the Burial Customs of MM/MH III – LM/LH IIIA1 Mainland Greece and Knossos
This study explores different ways of interpreting mainland and Knossian burial customs and assessing the manner in which they were used to explore themes of political and social status. In order to complete this study, correspondence analysis was applied to 98 tombs from Bronze Age (1700-1360 BCE) Knossos, Pylos, and Mycenae. Through the use of CA 14 hidden clusters and two hypotheses were generated and then analyzed in order to answer the following three research questions: can traditional explanations for the changes seen in Final Palatial Knossian burial customs be challenged; does the nature of Final Palatial burial customs support the theory of a mainland invasion; and can these patterns inform us about Knossian, Pylian, and Mycenaean society and the manners in which burials were used for social and political display. By answering these questions it became possible to understand Knossian, Pylian, and Mycenaean societies and their diverse uses of burial customs to display social and political status. Author Keywords: Burial Customs, Correspondence Analysis, Final Palatial Period, Mortuary Studies, Mycenaean Crete
Stable Isotope Analysis of Archaeological Faunal Remains From the Middle Trent Valley, Ontario
A sample of faunal remains (n=129) from seven archaeological sites located on Pigeon and Rice Lakes, Ontario were sampled and analyzed for the stable carbon and nitrogen isotopic composition of bone collagen. These samples date from the Archaic to Late Woodland and include 35 different animal species. The goal of this research was to investigate the isotope ecology of the Middle Trent Valley and characterize the degree to which isotope ratios varied across space and time between different lakes, as wells as variation within and between species. There were no statistically significant differences in the Middle Trent Valley δ13C or δ15N according to space and time. As such, the isotope data for all archaeological sites were combined to construct an isotope food web for the Middle Trent Valley and compared to Katzenberg’s (1989) food web. These isotope data provide some insight into the dynamic interplay between local ecosystems, and anthropogenically modified landscapes in Ontario. Author Keywords: carbon, food web reconstruction, human-animal relations, Middle Trent Valley, nitrogen, Stable isotope ecology
Stability Properties of Disease Models under Economic Expectations
Comprehending the dynamics of infectious diseases is very important in formulating public health policies to tackling their prevalence. Mathematical epidemiology (ME) has played a very vital role in achieving the above. Nevertheless, classical mathematical epidemiological models do not explicitly model the behavioural responses of individuals in the presence of prevalence of these diseases. Economic epidemiology (EE) as a field has stepped in to fill this gap by integrating economic and mathematical concepts within one framework. This thesis investigated two issues in this area. The methods employed are the standard linear analysis of stability of dynamical systems and numerical simulation. Below are the investigations and the findings of this thesis: Firstly, an investigation into the stability properties of the equilibria of EE models is carried out. We investigated the stability properties of modified EE systems studied by Aadland et al. [6] by introducing a parametric quadratic utility function into the model, thus making it possible to model the maximum number of contacts made by rational individuals to be determined by a parameter. This parameter in particular influences the level of utility of rational individuals. We have shown that if rational individuals have a range of possible contacts to choose from, with the maximum of the number of contacts allowable for these individuals being dependent on a parameter, the variation in this parameter tends to affect the stability properties of the system. We also showed that under the assumption of permanent recovery for disease coupled with individuals observing or not observing their immunity, death and birth rates can affect the stability of the system. These parameters also have effect on the dynamics of the EE SIS system. Secondly, an EE model of syphilis infectivity among &ldquo men who have sex with men &rdquo (MSM) in detention centres is developed in an attempt at looking at the effect of behavioural responses on the disease dynamics among MSM. This was done by explicitly incorporating the interplay of the biology of the disease and the behaviour of the inmates. We investigated the stability properties of the system under rational expectations where we showed that: (1) Behavioural responses to the prevalence of the disease affect the stability of the system. Therefore, public health policies have the tendency of putting the system on indeterminate paths if rational MSM have complete knowledge of the laws governing the motion of the disease states as well as a complete understanding on how others behave in the system when faced with risk-benefit trade-offs. (2) The prevalence of the disease in the long run is influenced by incentives that drive the utility of the MSM inmates. (3) The interplay between the dynamics of the biology of the disease and the behavioural responses of rational MSM tends to put the system at equilibrium quickly as compared to its counterpart (that is when the system is solely dependent on the biology of the disease) when subjected to small perturbation. Author Keywords: economic and mathematical epidemiology models, explosive path, indeterminate-path stability, numerical solution, health gap, saddle-path stability, syphilis,
Sponsoring Private Schools in an Informal Empire
This thesis analyzes the history of the Inter-American Schools Service (IASS), which ran under the auspices of the American Council on Education beginning in 1943. The program was defined as a private initiative aimed at spreading U.S. democratic values throughout the hemisphere for the mutual benefit of both the United States and Latin America. Yet the program was ultimately one facet of the United States' informal imperialism and a tool for the consolidation of U.S. hegemony, which came at the expense of Latin Americans' pursuit of the very values the IASS was said to facilitate. This theme is explored through a general discussion of cultural policy in the twentieth-century United States as well as the specific history of the IASS program and its relation to U.S. policies of intervention in Guatemala and Bolivia. Author Keywords: American Schools, Cultural Imperialism, Guatemala, Hegemony, Informal Imperialism, Inter-American Schools Service
Spirituality, Community and Compassion Matter! Exploring Motivators to Providing Holistic Social and Health Services in Peterborough, Ontario
My research explores potential motivators for social and health service providers to be more holistic and compassionate with those they serve. From previous research focused on spirituality, I identified seven additional concepts: faith, religion, community, culture, compassion, wellness, and wholeness. Using elements of Appreciative Inquiry, data was collected through a focus group and an in-depth, online survey. The participants work with Indigenous, religious, other spiritually motivated, or non-spiritual social or health service organizations in Peterborough, Ontario, Canada. Prototype concept analysis allowed participants to personally define each concept, and then indicate how much each motivated them. Results indicate, regardless of individual demographics, the definitions and motivations are very personal. The concepts with the most to least motivational impact were community, compassion, spirituality, wellness, wholeness, culture, faith and religion. Participants' voices speak directly through this research. I use their suggestions to make recommendations for improving the systems within which they provide service. Author Keywords: community, compassion, health services, indigenous knowledge, social services, spirituality
Speciation of Aluminum and Zinc in Three Streams of a Forested Catchment of the Boreal Zone
This study presents a detailed assessment of the chemical speciation of aluminum and zinc in three streams of a small, acid-sensitive forested catchment on the southern edge of the Precambrian Shield. Speciation analysis was achieved using an in-situ analytical technique known as Diffusive Gradient in Thin film (DGT) which measures labile metals, and a predictive computer algorithm (WHAM VI) which calculates metal species concentrations. Three types of DGT with different metal scavenging capabilities were used and a total of 11 deployments performed across four seasons. WHAM VI predictions showed that the organic fraction of aluminum was the main contributor to the dissolved concentrations in the main inflow stream (PC1) (~ 80 %) and the lake's outflow (PCO) (~ 75%); in the upland stream (PC1-08) the inorganic fraction contributed ~ 75%. For zinc the free ion was the single most important contributor to the dissolved concentration (< 90%) in all three streams. A comparative study of the DGT and WHAM methods showed an agreement between their inorganic concentrations during the spring season. Both methods indicate the greatest environmental impact for Al takes place during snow melt period in PCO and PC1-08 and in the summer for PC1. The greatest environmental impact for Zn predicted with WHAM VI, occurs during the spring in all three streams. Author Keywords: Aluminum, DGT, Metal speciation, WHAM, Zinc
Speaking of Being
The central question of this research is “What is poetry?” The ambiguity and unintelligibility of the question itself forces the writing to take two different approaches to it. The first approach is to define poetry not by what it is but by how it is related to the human being and to the world. Seeing poetry as its relation to Being allows a definition of poetry based on its function. This approach draws on philosophical discussions how poetry is related to the human and how Being can be extended into poetic creation. Martin Heidegger’s move from seeing poetry as the possibility of worldmaking to seeing it as a place of dwelling, and, in his later works, as unconcealment and the extension of Being as the House of Being, marks the direction of philosophical discussions in this paper. In this sense, poetry is defined as a creative possibility, where the speaking being comes in close contact with the speaking things and speaks of being.The second approach is to define poetry not as a whole but as some of its essential parts, as “poetic imagination” for instance. This attempt to define the poetic imagination draws on long-running discussions of imagination, metaphor, metaphorical thinking, image and imaging. It also relies on Freud’s discussions of how dreams function as textual phenomena: the poetic imagination, this approach argues, is similar to dreaming. The poet’s conscious and unconscious engagements with language create an uncanny experience where the relation between object and its poetic image is simultaneously known and unknowable. The third part of this study focuses on Lacan’s move from the symbolic unconscious to the real unconscious, in order to shed light on how the real is related to its linguistic reality. This brings the discussion to a point where language is replaced by lalangue in order to knot the real directly to the symbolic. Author Keywords: poetic creation, poetic imagination, poetry
Spatial dynamics of pollination in dioecious Shepherdia canadensis in Yukon, Canada
Sexual reproduction in flowering plants depends on investment in reproduction, the mode of pollen transfer, the availabilities of nutrient resources and potential mates, and the spatial scales over which these processes take place. In this thesis, I studied the general reproductive biology of Shepherdia canadensis (L.) Nutt. (Elaeagnaceae) and the suite of pollinators that visit the plants in Ivvavik National Park, Yukon, Canada. Across ten sites, I found that S. canadensis females were larger than males, but males produced more flowers than females at most sites. Males typically occurred at higher frequencies than females with the average male to female sex ratio being 1.19 ± 0.08 (mean ± SE, n = 10 sites). Both shrub size and flower production were significantly influenced by interactions between soil nitrogen and sex. Insect visitors to S. canadensis flowers were primarily ants and flower flies (Syrphidae), but exclusion experiments indicated that visitation by flying insects yielded greater fruit production than visitation by crawling insects. I found that fruit set was limited by the density of males within populations, but only over small distances (4-6 m). This is the first study to demonstrate that female reproductive success of a generalist-pollinated dioecious plant is limited by the density of males over small spatial scales. Author Keywords: dioecy, pollinators, sex ratio, sexual dimorphism, Shepherdia canadensis
Spatial and Temporal Variation in Peatland Geochemistry in Sudbury, Ontario, Canada
The damage to Sudbury's landscape from over a century of smelter and logging activity has been severe and impacts well documented. However, despite their abundance in the region, wetlands have received little attention. Recent studies have identified that nutrient limitation is as much a problem as metal toxicity and highlighted not only the importance of wetlands but also the need for more detailed studies examining the role of wetlands in the recovery of lakes. The objective of this work is to characterize the spatial and temporal variability in the geochemistry of 18 wetlands (poor fens) surrounding Sudbury, Ontario. Peat and water chemistry in the wetlands exhibited large spatial and temporal variability. Copper and Ni concentrations in surface peat decreased with distance from the largest smelter in the area, but water chemistry was also strongly influenced by natural factors such as climate, groundwater and peat carbon content. Redox processes contribute greatly to temporal variation in pore-water chemistry: the August and October campaigns were characterized by higher SO4, lower pH and higher concentrations of metals such as Ni, Cu and Mn compared with the May campaign. Other factors contributing to the temporal variability in pore water chemistry include DOC production, senescence and water source. Despite the large variability, soil-solution partitioning can be explained by pH alone for some metals. Modeling is significantly improved with the addition of other variables representing dissolved organic matter quality and quantity, sulphate concentration and hydrology. Author Keywords: metal contamination, metal mobility, organic matter quality, peatland geochemistry
Spatial Dynamics of Wind Pollination in Broadleaf Cattail (Typha latifolia)
Natural populations of flowering plants rarely have perfectly uniform distributions, so trends in pollen dispersal should affect the size of the pollination neighbourhood and influence mating opportunities. Here I used spatial analysis to determine the size of the pollination neighbourhood in a stand of the herbaceous, wind-pollinated plant (Typha latifolia; broad-leaved cattail) by evaluating patterns of pollen production and seed set by individual cattail shoots. I found a positive correlation between pollen production and seed set among near-neighbour shoots (i.e., within 4 m2 patches of the stand; Pearson's r = 0.235, p < 0.05, df = 77) that was not driven by a correlation between these variables within inflorescences (Pearson's r = 0.052, p > 0.45, df = 203). I also detected significant spatial autocorrelations in seed set over short distances (up to ~ 5 m) and a significant cross-correlation between pollen production and seed set over distances of < 1 m indicating that the majority of pollination events involve short distances. Patterns of pollen availability were simulated to explore the shape of the pollen dispersal curve. Simulated pollen availability fit actual patterns of seed set only under assumptions of highly restricted pollen dispersal. Together, these findings indicate that even though Typha latifolia produces copious amounts of pollen, the vast majority of pollen dispersal was highly localized to distances of ~ 1 m. Moreover, although Typha latifolia is self-compatible and has been described as largely selfing, my results are more consistent with the importance of pollen transfer between nearby inflorescences. Therefore, realized selfing rates of Typha latifolia should largely depend on the clonal structure of populations. Author Keywords: clonal structure, correlogram, dispersal curves, pollination, spatial analysis, Typha latifolia
Spatial Bestiary
In my Master’s thesis, I consider how the space of the animal laboratory shapes human-animal relationships, and how, in turn, these relations impact the laboratory, and more specifically, the spatially-bound practices that unfold in this space. I use the frameworks of biopolitics and animal geography, both of which help in illuminating the space of the lab as a site of power, within which human-animal agency becomes exercised. Alongside these analytics, I conducted participant interviews with individuals who work with animals in laboratories or settings similar to laboratories, which animate several themes that I locate at the intersection of biopolitics and animal geography. These themes include a discussion of human-animal relations of power, scientific biopower and scientific market economies, the animal-industrial complex, and the relationship between human binaries and their effects on spatiality. This project is as much about animal lives as it is about human lives. Author Keywords: agency, animal geography, biopower, human-animal relationships, spatiality, the animal laboratory


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Format: 2023/09/28