Graduate Theses & Dissertations

Pages

Phosphorus forms and response to changes in pH in acid-sensitive soils on the Precambrian Shield
Catchment soil acidification has been suggested as a possible mechanism for reducing phosphorus (P) loading to surface waters in North America and northern Europe, but much of the research that has been conducted regarding P immobilization in pH manipulated soils has been performed at high P concentrations (> 130 μM). This study investigated how soil acidity was related to P fractionation and P sorption at environmentally relevant P concentrations to evaluate the potential influence of long term changes in soil pH on P release to surface waters. Total phosphorus (TP) concentrations declined between 1980 and 2000 in many lakes and streams in central Ontario; over the same time period forest soils in this region became more acidic. Soils were collected from 18 soil pits at three forested catchments with similar bedrock geology but varying TP export loads. The soil pH at the 18 study soil pits spanned the historic soil pH range, allowing for `space for time' comparison of soil P factions. Soils were analysed by horizon for P fractions via Hedley P fractionation. Batch P sorption experiments were performed on selected B-horizon soils at varied solution pH. Soil P fractions varied by horizon but were comparable among the three catchments, with only apatite (PHCl) differing significantly across catchments. Contrary to expectation, both soluble and labile P showed negative relationships with pH in some horizons. Mineral soils were able to sorb almost all (> 90 %) of the P in solution at environmentally relevant P concentrations (4.5 - 45.2 μM). Phosphorus sorption at environmentally relevant P concentrations was unrelated to solution pH but at high P concentration there was a positive relationship between P sorption and solution pH, suggesting a P concentration dependant P sorption mechanism. Phosphorus budgets indicate that P is accumulating within catchments, suggesting that P is being immobilized in the terrestrial environment. An alternative hypothesis, which attempts to explain both the decline in stream TP export and terrestrial P accumulation, is discussed. The results from this study suggest that acidification induced P sorption in upland soils are not a contributing factor to decreases in stream TP concentration in the study catchments. Author Keywords: central Ontario, Hedley fractionation, phosphorus, podzols, soil acidification, sorption
Talking it out
The literature to date that investigates the development of social perspective taking in children primarily focuses on preschool aged children. These studies provide evidence that implicates language as being crucial for social perspective taking in young children but less is known about the importance of language to social perspective taking during middle childhood and early adolescence. The current study uses Selman's theory of socio-cognitive development to investigate the maturation of social perspective taking and the importance of language to social problem solving in 8 year olds (n = 111) and 12 year olds (n = 112). Analysis of variance and scalogram analysis shows a developmental progression of social perspective taking across the social problem solving process. Children may be able to demonstrate reciprocal perspective taking when generating strategies before they are able to demonstrate reciprocal perspective taking for other steps of social problem solving. Flexibility in interpersonal orientation is shown to be a predictor of social problem solving ability. Correlations and multiple regression analysis demonstrate that language is important to overall social problem solving but that the role of semantic and syntactic language may differ at age 8 compared to age 12. Author Keywords: interpersonal orientation, language, Selman, social cognition, social perspective taking, social problem solving
Test for Pluralism
This study intervenes into the debate regarding the definition of pluralism in ecological economics and how that definition affects various characterizations of ecological economics. The methodological pluralist camp argue for the inclusion of neoclassical economics into the ecological economics fold, while the critical pluralist camp argue against the inclusion of neoclassical economics. This study provides a critical exposition of the preanalytical visions of neoclassical and ecological economics that includes their respective ontological and epistemological foundations. Those foundations are critically scrutinized for coherence, realism and relevance, and their respective ability to analyze complex systems. It is argued that combining neoclassical and ecological economics renders ecological economics incoherent, and that neoclassical economics fails the test of realism, and its conceptual apparatus is only capable of analyzing simple systems. It is also argued that ecological economics is coherent, passes the test of realism because it is ontologically, socio-historically, and descriptively realistic, and the conceptual apparatus of institutionalist ecological economics incorporates complex systems. It is concluded that practitioners of ecological economics ought to reject and jettison neoclassical economics from their fold and to develop closer connections to and alliances with practitioners of heterodox economics. Keywords: Ecological Economics, Ontology, Coherence, Realism, Systems Thinking. Author Keywords: Coherence, Ecological Economics, Ontology, Systems Thinking
First Time…A Second Time
The purpose of the current study was to explore virginity loss experiences in lesbian, gay, and bisexual individuals (LGB), specifically those who have had both a sexual experience with a member of a different sex and a member of the same sex. This phenomenon is what the current study is defining as second virginity loss. Participants consisted of 645 LGB self-identified individuals, the sample was approximately half women (53%) and ages ranged from 18-65. Further, six semi-structured interviews were conducted to gain a clearer understanding of LGB individuals virginity loss experiences. Of the sample, approximately 60% of each sexual orientation reported having two sexual experiences they equated with virginity loss, one with a member of a different sex, and one with a member of the same sex. Analyses of both the qualitative and quantitative data were conducted in an attempt to gain an understanding in three main areas: (1) definitions of virginity loss, (2) virginity beliefs, and (3) motivations. It was found that LGB individuals continue to hold heteronormative definitions of virginity loss, i.e. penile-vaginal intercourse, though these definitions were found to be transitional in nature. LGB individuals also seem to hold more gift related beliefs toward their same-sex experience and more stigma related beliefs toward their different sex experience, however, as shown by previous research (Carpenter, 2001, 2002), most LGB individuals highly endorsed process beliefs. Finally, motivations for virginity loss were found to be consistent with two main themes: validation and drive. Overall, this research suggests that the LGB community has a fairly complicated relationship with virginity but certainly do not feel exempt from the concept or the pressures attached. The current study is the first to explore the phenomenon of second virginity loss in LGB individuals and should be used as a foundation for future research in both first sexual experience and LGB fields to build upon. Author Keywords: first sexual experience, LGB, mixed-methods, second virginity loss, virginity
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,
origin and ecological function of an ion inducing anti-predator behaviour in Lithobates tadpoles
Chemical cues are used commonly by prey to identify predation risk in aquatic environments. Previous work has indicated that negatively-charged ions of m/z 501 are possibly a kairomone that induces anti-predator responses in tadpoles. This thesis found that this ion species: (i) is produced by injured tadpoles; (ii) exhibits increased spectral intensity with higher tadpole biomass; and (iii) is not produced by starved predators. These results refute the hypothesis that the ion is a kairomone, and rather support its role as an alarm cue released from tadpoles. High resolution mass spectrometry (HR-MS) revealed a unique elemental composition for [M-H]-, m/z 501.2886, of C26H45O7S-. Collision induced dissociation (CID) of ion m/z 501 formed product ions of m/z 97 and m/z 80, HSO4- and SO3-, respectively, indicating the presence of sulfate. Green frog (Lithobates clamitans) tadpoles exposed to m/z 501, and an industrial analogue, sodium dodecyl sulphate (NaC12H25O4S), exhibited similar anti-predator responses, thereby suggesting the potential role of organic sulfate as a tadpole behavioural alterant. Author Keywords: Alarm cue, Amphibian, Chemical Ecology, Mass spectrometry, Predator-prey interactions
Behavioural ecology and population dynamics of freshwater turtles in a semi-urban landscape at their northern range limit
Species are faced with a variety of challenges in the environment, including natural challenges, such as variability in ambient temperature, and anthropogenic threats, such as habitat transformation associated with urbanisation. Understanding how animals respond to these kinds of challenges can advance the field of behavioural ecology and guide management decisions for wild species. Yet, we still have limited understanding of the extent of natural and human-caused impacts on animal behaviour and population dynamics, and lack robust assessment of behaviour in free-ranging animals. Using novel miniaturised biologging technologies, I characterised and validated behaviour in two freshwater turtle species: Blanding’s turtles (Emydoidea blandingii) and Painted turtles (Chrysemys picta). Further, I investigated how these two ectothermic species navigate a thermally heterogeneous landscape near their northern range limit, by comparing selected and available ambient temperatures. I showed that turtles preferred locations that were, on average, warmer and less variable in temperature than the available environment, and that this thermal sensitivity was greatest early in the year, and at fine spatial scales that likely matched the species' perception of the environment. Lastly, I assessed whether urban development was compatible with long-term viability of a Blanding’s turtle population, by monitoring habitat change and turtle survival over one decade of ongoing residential and road development. I found that Blanding’s turtle habitat quantity and connectivity declined in the area, which coincided with high road mortality and severe declines in turtle survival and population size, especially in adult females. I concluded that urban development and current road mortality rates are incompatible with the long-term viability of this at-risk turtle population. Overall, my findings demonstrate the importance of variation in the thermal environment and anthropogenic impacts on habitat in shaping the behaviour and population dynamics of this species-at-risk. Author Keywords: animal behaviour, biologging, ectotherms, habitat selection, temperature, urbanisation
Hearing the Invisible Empire
This study investigates the origins of the music produced by the 1920s Ku Klux Klan in Indiana as well as trying to understand how it facilitated recruitment into the Klan and how it was used as a tool for wider social and political change. The Indiana Klan’s newspaper The Fiery Cross is awash in reports of parades and other public performances of music, yet this phenomenon has remained unstudied. Klan musical performances were modelled after the practises of the evangelical revival, which allowed Klansmen to present themselves as an alternative religious community. In so doing the Klan came to dominate the public life of many towns and cities across Indiana. In areas that experienced Klan music, Klansmen, and other protestants, mobilized on issues relating to immigration, education, and elections. This is the first study of its kind and the results in Indiana encourage further study in other states. Author Keywords: Billy Sunday, Conservative Social Movement, Evangelical Revival, Far-Right, Hate Group, Ku Klux Klan
Prepared for the Next War? U.S. Attachés Reports, Military Innovation and the Spanish Civil War
The Spanish Civil War was a theatre of political tension where democracy, communism, and fascism clashed during the interwar period, starting in July 1936 and ending in April 1939. The war defied the traditional concept of a civil war as Germany, Italy, and the Soviet Union became involved. All three saw Spain as a testing ground for new military technologies. Meanwhile the United States government stayed steadfast in its isolationist approach to foreign conflict and sent no aid to either side. American military attachés, who are military observers to foreign nations, in Spain witnessed the ongoing conflict, creating detailed reports of their observations before, during, and after the war. This thesis argues that the reports, which contained valuable information regarding military technology and doctrine, had little impact on American military innovation during the interwar period. This was due to both politically dictated neglect and doctrine prejudice regarding European conflicts. Based on the attaché reports, this thesis will explain what Germany, Italy, and the Soviet Union learned about aviation, tanks, and artillery from their participation in Spain. This will be contrasted with the state of the United States’ military at the same time to demonstrate not only the little impact the attaché reports had on the trajectory of the American military, but how the military lagged behind those in Spain upon the beginning of the Second World War. Author Keywords: American military attachés, Germany, Italy, Military Intelligence Division, Soviet Union, Spanish Civil War
Development of a Digital Comparative Collection of Chert Types in Ontario and the Evaluation of Change in Accuracy and Confidence of Chert Type Identifications
The objective of this thesis is to create a foundation for a digital comparative collection of chert types found on archaeological sites in Ontario, both local and non-local varieties, and to evaluate the impact of a digital reference collection on the confidence and accuracy of the user in comparison to hard copy guides or hand samples that are more often traditionally used. Spatial and temporal variation in the use of different lithic raw materials has shown to provide insight into cultural interaction, resource exchange and control across multiple periods in the study of Indigenous archaeology; however comparative collections needed to conduct analyses remain accessible only in a physical form. This study will build a foundation, develop a prototype using a represented sample of hand specimens from the William Fox Northeastern North American Lithic Reference Collection (referred to hereafter as The Fox Collection) at Trent University, and create a prototype digital system to assist the user in identifying the chert type through the use of a simple expert system using a decision tree. The digital identification system was tested by a group of volunteers with to compare accuracy and confidence in analysis against traditional methods of hand samples and hard copy guides. When supplied with the digital reference collection, a statistically significant improvement in the accuracy and confidence of chert identification was identified. Author Keywords: database design, digital comparative collection, digital identification system, expert system, Ontario archaeology, raw material analysis
Bringing Knowledges Together
The natural world and environmental issues present critical points of convergence between Indigenous and non-Indigenous people and their knowledge systems. This qualitative study engaged with 18 Indigenous and non-Indigenous environmental practitioners in interview conversations to explore their experiences in cross-cultural environmental collaborations. The research undertakes a complexity theory approach to answer the following research questions: 1.a) What skills, values, knowledges and approaches do environmental practitioners need to enable Western and Indigenous knowledge systems to come together in addressing environmental challenges? 1. b) What does effectiveness and/or success look like in cross-cultural environmental collaboration? 2. How can post-secondary and professional development educational programs impart the skills, values, knowledges and approaches that their students need to effectively engage in work that brings together Indigenous and non-Indigenous people and their knowledge systems in addressing environmental challenges? This study applied multiple lenses to analyze and interpret the data. The author’s own reflections as both a practitioner and researcher working and teaching in crosscultural environmental contexts were a central component of the study. Through this analysis a set of skills, values, knowledges, approaches, attributes, and roles emerged. The findings reaffirm the importance of respect, relationship, responsibility, and reciprocity as central values in Indigenous praxis and identify additional values. The application of a critical theory lens illuminated that subtle racism and microaggressions influence environmental collaboration between Indigenous and non-Indigenous people. The study proposes a curriculum and program design for post-secondary and professional development contexts, that draws upon multiple pedagogies to prepare learners to work cross-culturally in respectful ways. These findings are relevant to environmental practitioners currently working in the field and contribute to a further articulation of an emerging Indigenous Environmental Studies and Sciences (IESS) pedagogy. Author Keywords: Cross-cultural collaboration, Curriculum Development, Environmental Education, Indigenous Studies, Professional Development
Lives of Young Delinquents
The Royal Philanthropic Society (RPS) was the first institution in England to care for young offenders. While historians have demonstrated the legal importance of this institution, none have examined the experience of the youths it attempted to reform. The admission registers of the RPS reveal the importance of adults and peers in the experiences of the inmates of the institution, as both could be sources of conflict and support. Youths could express power over their own lives by resisting the authority of adults, but also by conforming to the rules of the RPS. Inmates could restrict the choices of their peers by working with the RPS, but also through peer pressure or violence. Networks of collaboration and youth culture could also exert a positive impact on peers. Because this thesis represents male youths as actors, it makes a significant addition to recent histories emphasizing the impact of the subaltern groups on eighteenth-century reform movements. Author Keywords: Conformity, Juvenile Delinquency, Penal Reform, Power Relationships, Royal Philanthropic Society, Youth Culutre

Pages

Search Our Digital Collections

Query

Enabled Filters

  • (-) ≠ Southeast Asian studies

Filter Results

Date

1974 - 2024
(decades)
Specify date range: Show
Format: 2024/02/24