Graduate Theses & Dissertations

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ASSESSING THE IMPACT OF ATMOSPHERIC DEPOSITION AND HARVEST INTENSITY ON SOIL ACIDITY AND NUTRIENT POOLS IN PLANTATION FORESTS
The objective of this thesis was to assess the influence of anthropogenic sulphur (S) and nitrogen (N) deposition, and harvesting on soil acidity and calcium (Ca2+), magnesium (Mg2+), potassium (K+) and N soil pools in plantation forest soils in Ireland. The response to reductions in anthropogenic S deposition was assessed using temporal trends in soil solution chemistry at two long-term monitoring plots--one on a blanket peat, the other on a peaty podzol. At the peat site, there was little evidence of a response to reductions in throughfall non marine sulphate (nmSO42-) and acidity; soil water acidity was determined by organic acids. In addition, temporal variation in soil water did not respond to that in throughfall. In the podzol, reductions in anthropogenic S and H+ deposition led to a significant improvement in soil water chemistry at 75 cm; pH increased and total aluminum (Altot) concentrations declined. The impact of harvest scenarios on exchangeable Ca2+, Mg2+ and K+ pools was assessed using input-output budgets at 40 sites (30 spruce, 10 pine). Harvest scenarios were stem-only harvest (SOH), stem plus branch harvest (SBH) and stem, branch and needle harvest (whole-tree harvesting; WTH). Average K+ and Mg2+ budgets were positive under these scenarios. However, exchangeable K+ pools were small and due to uncertainty in K+ budgets, could be depleted within one rotation. Average Ca2+ budgets for spruce were balanced under SOH, but negative under SBH and WTH. Nitrogen deposition was high, between 5 and 19 kg N ha-1 yr-1, but was balanced by N removal in SOH. However, N budgets were under SBH and WTH, indicating that these harvesting methods would lead to depletion of soil N over the long-term. Finally, monitoring of N cycling at a spruce plot indicated that N deposition was contributing to large NO3- leaching, and as such the site was N saturated. However, N cycling did not fit the criteria of the N saturation hypothesis; instead leaching was directly related to N deposition and supported the model of kinetic N saturation. Author Keywords: acidic deposition, base cations, input-output budgets, Ireland, nitrogen, whole-tree harvesting
Abject Utopianism and Psychic Space
This dissertation utilizes the psychoanalytic theories of French psychoanalyst Julia Kristeva as a lens through which to read the novels of American author Samuel R. Delany. I argue that concepts proper to Kristeva's work--namely abjection and/or the abject--can provide a way to think what it might mean to be utopian in the 21st century. Delany's novels are received historically, which is to say his work speaks from a certain historical and cultural viewpoint that is not that of today; however, I claim that his novels are exceptional for their attempts to portray other ways of being in the world. Delany's novels, though, contain bodies, psychologies, and sexualities that are considered abject with respect to contemporary morality. Nonetheless, this dissertation argues that such manifestations of abject lived experience provide the groundwork for the possibility of thinking utopianism differently today. Throughout, what I am working toward is a notion that I call Abject Utopianism: Rather than direct attention toward those sites that closely, yet imperfectly, approximate the ideal, one should commit one's attention to those sights that others avoid, abscond, or turn their nose up at in disgust, for those are the sites of hope for a better world today. Author Keywords: Abject, Delany, Kristeva, Literary Criticism, Psychoanalysis, Utopia
Advanced broadband CARS microscopy based on a supercontinuum-generating photonic crystal fiber
I have developed and improved a coherent anti-Stokes Raman scattering (CARS) microscope based on the spectral focusing (SF) technique. The CARS microscope uses an 800 nm oscillator and a photonic crystal fibre module to generate the supercontinuum Stokes. The photonic crystal fibre was originally designed to generate light beyond 945 nm which is useful for CARS microscopy in the CH/OH frequencies but essentially prevents access to the important fingerprint region at lower frequencies. With expert and nontraditional approaches to generating supercontinuum with sufficient power at wavelengths below 945 nm, I substantially extend the usefulness of the module for SF-CARS microscopy deep into the fingerprint region. Moreover, with the invention of a dynamic supercontinuum generation scheme we call "spectral surfing," I improve both the brightness of the CARS signal and extend the accessible CARS frequency range to frequencies as low as 350 cm$^{-1}$ and as high as 3500 cm$^{-1}$---all in a single scan-window. I demonstrate the capabilities of our broadband SF-CARS system through CARS and four-wave mixing hyperspectroscopy on samples such as astaxanthin, lily pollen and glass; liquid chemicals such as benzonitrile, nitrobenzene and dimethyl sulfoxide; and on pharmaceutical samples such as acetaminophen, ibuprofen, and cetirizine. Furthermore, In search of more useful Stokes supercontinuum sources, I compare the performance of two commercial photonic crystal fibre modules for use in SF-CARS applications, ultimately finding that one module provides better spectral characteristics for static supercontinuum use, while the other provides improved characteristics when spectral surfing is implemented. Author Keywords: coherent anti-Stokes Raman scattering, nonlinear microscopy, scanning microscopy, spectroscopy, supercontinuum generation, vibrational spectroscopy
Alien Imaginaries
This dissertation offers a cultural analysis of UFOs and extraterrestrials in the United States. In it I look at what I call real aliens — extraterrestrials believed to be real and interacting with humans on Earth. Beliefs in real aliens are often denigrated and dismissed in official discourse, yet they continue to not only persist, but thrive, in American society. Hence, this dissertation asks: Why do so many people believe that extraterrestrials are visiting our planet? Part One begins by tracing the invasion of real aliens in the United States using Orson Welles’s 1938 radio broadcast “The War of the Worlds” as a starting point. Here, I look at how and why the broadcast registered with listeners’ anxieties and created a fantastic and uncanny effect that made it possible for some to conceive of aliens invading the United States. In Part Two, I trace the rise of ufology, which involves the study of extraterrestrials currently interacting with humans on Earth, and I consider how the social and political climate of the Cold War, as well as the cultural environment of postmodernity, provided the necessary conditions for stories about aliens to be made believable. Part Three explores the case study of the Roswell Incident, a conspiracy theory about the origins of an alleged flying saucer crash and government cover-up. I look at the reasons for why many individuals have come to believe in this conspiracy theory and I reflect on the tensions between “official” and “unofficial” discourses surrounding this case. I also consider how and why Roswell has become such an important site for ufology, and I examine the performances given by ufologists at the annual Roswell International UFO Festival to appreciate how ufologists offers seductive explanations of why things are the way they are; for many, their stories offer a better version of events than the purely rational and positivist explanations offered by official sources, especially since they tap into the disillusionment and mistrust that many Americans feel about contemporary politics. Author Keywords: aliens/extraterrestrials, America, conspiracy, official and unofficial, storytelling, ufology
All Things Fusible
This dissertation presents the work of the American science fiction writer Neal Stephenson as a case study of mediations between literature and science by mobilizing its resonances with contemporary science studies and media theory. Tracing the historical and thematic trajectory of his consecutively published novels Snow Crash (1992), The Diamond Age; or, A Young Lady’s Illustrated Primer (1995), Cryptonomicon (1999), Quicksilver: The Baroque Cycle I (2003), The Confusion: The Baroque Cycle II (2004), and The System of the World: The Baroque Cycle III (2004), it approaches Stephenson’s fiction as an archaeology of the deep history of science that leads from late twentieth-century cyberculture, to world-war-two cryptography, and the seventeenth-century rise of the Royal Society. Refracted through a parallel reading of Stephenson’s novels and the theoretical work of Michel Serres, Bruno Latour, Friedrich A. Kittler, Isabelle Stengers, Donna Haraway, and others, this dissertation offers a literary discussion of the relations among cybernetics, complexity theory, information theory, systems theory, Leibnizian metaphysics, and Newtonian alchemy. Recognizing these hybrid fields as central to contemporary dialogues between the natural sciences and the humanities, Stephenson’s work is shown to exhibit a consistent engagement with the feedback loops among physical, artistic, narratological, and epistemological processes of innovation and emergence. Through his portrayal of hackers, mathematicians, natural philosophers, alchemists, vagabonds, and couriers as permutations of trickster figures, this dissertation advances a generalized notion of boundary transgressions and media infrastructures to illustrate how newness emerges by way of the turbulent con-fusion of disciplines, genres, knowledge systems, historical linearities, and physical environments. Uninterested in rigid genre boundaries, Stephenson’s novels are explored through the links among artistic modes that range from cyberpunk, to hard science fiction, historiographic metafiction, the carnivalesque, and the baroque. In a metabolization of the work performed by science studies, Stephenson’s fiction foregrounds that scientific practice is always intimately entangled in narrative, politics, metaphor, myth, and the circulation of a multiplicity of human and nonhuman agents. As the first sustained analysis of this segment of Stephenson’s work, this dissertation offers a contribution to both science fiction studies and the wider field of literature and science. Author Keywords: Complexity Theory, Cyberpunk, Michel Serres, Neal Stephenson, Science Fiction, Science Studies
An Investigation of Rare Earth Element Patterns and an Application of Using Zn and Cd Isotope Ratios in Oysters to Identify Contamination Sources in an Estuary in Southern China
Environmental monitoring and investigation of metal biogeochemical cycling has been carried out in the Pearl River Estuary (PRE), an important and complex system in Southern China. In this study, rare earth element (REE) patterns as well as isotope ratios (i.e., Zn and Cd) were evaluated as tools to identify contamination sources in environmental compartments (i.e., water and suspended particles (SP)) as well as in oysters collected from estuarine sites. Results show elevated concentrations (also called anomalies) of Pr, Nd, Dy and Ho, relative to other REE elements, in water samples, potentially from REE recycling and other industrialized activities in this area. Unlike water samples, no REE anomalies were found in SP or oysters, suggesting that the dominate REE uptake pathway in oysters is from particles. Secondly, site to site variations in Zn isotope ratios were found in water and SP, showing the complexity of the source inputs in this area. Also, in estuarine locations, larger spatially differences in Zn isotope ratios were found in water collected in wet season than those in dry season, which may due to mixing of different source inputs under the water circulations in different seasons. A series of laboratory experiments were conducted during which changes in Zn isotope ratios were measured during uptake under varying salinity and Zn concentrations and during depuration. Neither in vivo Zn transportation among the various tissues within the oysters nor water exposure conditions (i.e., different salinities or Zn concentrations) caused Zn isotopic fractionation in the oysters. Cd and Zn isotope ratios were also determined in oysters obtained from the PRE. Large variations in Cd and Zn isotope ratios suggest that oysters were receiving contaminants from different input sources within the PRE. A consistent difference (approximately 0.67‰) was observed for Zn isotope ratios in oysters collected from the east side of the PRE compared to those from sampling locations on the western side of the PRE, suggesting different Zn sources in these two areas. Ultimately, by combining biogeochemistry with physiology, this study represents a first attempt to assess pollution status, monitor contaminants using oysters and model/identify contamination sources using both REEs and metal isotope ratios. Author Keywords:
Anarchist Periodical Press in the United States
This dissertation focuses on the English-language anarchist periodical press in the United States in the 1890s and early 1900s. Each of the three chapters of this dissertation examines one anarchist paper and its coverage of a specific issue. The first chapter focuses on Prison Blossoms, which was started by Alexander Berkman, Carl Nold, and Henry Bauer and written and circulated in the Western Penitentiary of Pennsylvania, and its engagement with Alexander Berkman's attempt to assassinate Henry Clay Frick. The second chapter examines Free Society, a weekly edited primarily by Abraham Isaak, and its contributors' writings on the assassination of President William McKinley by self-described anarchist Leon Czolgosz. Finally, the third chapter focuses on The Demonstrator, specifically its first volume which was edited by James F. Morton Jr. from the intentional community of Home, Washington, and the paper's work in supporting John Turner, the first anarchist targeted for deportation under the Immigration Act of 1903. Drawing upon critical discourse analysis, this dissertation incorporates examination of the context in which these papers were written (particularly the immediate concerns to which the papers' authors responded), the form and generic conventions of the anarchist press, including the approaches of the papers' respective editors, and the arguments advanced by their authors. It pays particular attention to the intertextuality of the anarchist press -- the ways in which those writing in anarchist papers addressed one another both within and across periodicals, generating anarchist thought through conversation and debate and enacting their anarchist ideals in the practice of publishing. This dissertation demonstrates that the anarchist periodical press, an element of anarchist history that has received little attention, offers important insights: it details how anarchists immediately responded to important issues of their time, and reveals the ways in which the emergence of anarchism was itself a collective effort, emerging from conversation, debate, and disagreement about how best to create radical change and what that change should look like. Author Keywords: anarchism, anarchist periodicals, critical discourse analysis, Free Society, Prison Blossoms, The Demonstrator
Anishinaabe Motherhood
The purpose of this qualitative study is to investigate Anishinaabe women’s Traditional Teachings and pedagogies in a contemporary context. Through this exploration, I have uncovered the tensions, challenges, and strengths that Anishinaabe gaashiyag (mothers) face when engaging with these Traditional Teachings and pedagogies. The research methodology I have used is a branch of grounded theory called the Anishinaabe Research Methodology, and it is integral to the Anishinaabe principles of living called the Seven Grandparent Teachings: Wisdom, Love, Respect, Bravery, Honesty, Humility, and Truth. I used a research method called the Nbwaachiwi (the art of visiting) method. I used the ‘Aunties kitchen table’ style of knowledge collection, where it is open-ended and one-on-one - like you would be at your auntie's kitchen table, sharing stories and having tea. By utilizing these principles, I conducted my research through the Anishinaabe-aadiziwin (culture and language – way of life) paradigm. I addressed multilayered Anishinaabe teachings and many connections to the land and spirituality. I have found that Anishinaabe gaashiyag feel pressure to adopt Western modes of raising their children. However, some young women are returning to the traditional Anishinaabe teachings by using traditional birthing techniques, tiknigaans (traditional baby carriers), and evolving our cultural practices to fit modern ways of living. The knowledge I present within this paper can inform mothers who want to learn Traditional Teachings and pedagogies, and thereby resist ongoing intergeneration trauma and colonization. New generations are identifying what the negative effects on raising Anishinaabe children and taking a stand to break ongoing trauma and abuse so that their children do not have to be subjected to it. These mothers are informed about cultural and Traditional Teachings with the hope that they can use this knowledge to assist them on their path to, and during, motherhood. Given the determination of these young mothers to raise their babies using Anishinaabe traditional methods, the future identities and lives of their children may be significantly better in a cultural sense than their predecessors. They will be the products of their mothers’ commitment to the resurgence of Anishinaabe maternal teachings and pedagogies. Author Keywords: Anishinaabe, Indigenous Motherhood, Motherhood, Parenting, Pedagogies, Teachings
Archaeology of Vagabondage
My research examines the figure of the 'vagabond' as a case study to illustrate how 'modern' perception of the 'vagabond' has depleted the diversities in its 'pre-modern' counterparts. It argues that the paranoia towards the 'vagabond' was inherited from the west out of the colonial contact leading to the birth of the nation-state and its liaison with 'instrumental rationality' during the high noon of advanced industrial capitalism, while (quasi-religious) itinerancy, on the contrary, had always been tolerated in 'pre-modern' India. The problems I am addressing are: What is the line of thread that separates the 'traveler' from the 'vagabond', the 'explorer' from the 'wanderer'? How do we then politically account for the historic 'ruptures' in the vagabond having been tolerated in the ancient 'Indic' thought [cf. Manusmriti, Arthshastra], encouraged in early Buddhist discourse [cf. Samannaphala Sutta], revered as the 'holy Other' in the Middle Ages [cf. Bhakti-Sufi literature], and eventually marginalized in the 'modern'? While considering issues of cultural differences, my thesis points to how the epistemic shifts from the classical to the medieval, from the medieval to the modern radically alter the value system immanent in the figure of the 'vagabond'. The research argues that the cultural baggage that the expression 'vagabond' is generally associated with, is a product of a specific western/utilitarian value system, which is a distinct 'cultural' category of the 'modern' west that had no resonance in 'pre- modern' India, and hence cannot be necessarily universalizable. The project works in a number of registers: historical, archival, cultural, philosophical and representational, involves analysis of literary, filmic texts, also legislative documents, and is genuinely interdisciplinary in nature. As of discourse analysis, the project studies the politics of cultural representations both of and by 'vagabonds'. Author Keywords: 1943 Bengal Famine, Homelessness, India, Vagabond, Vagrancy, Vagrancy Act
Assessing Measured and Perceived Risks to Drinking Water Sources
Microcontaminants originating from wastewater effluent and run-off from agricultural lands may be present in the sources of drinking water for rural and Indigenous communities in mixed-use watersheds. In this study, a convergent parallel mixed-methods design was applied to assess measured and perceived risks of contamination in the sources of drinking water for two communities; the Six Nations of the Grand River community in Ontario and the community of Soufriere in St. Lucia, West Indies. The overall goal of the project was to assess how measured and perceived risks of exposure to chemical and biological contaminants in drinking water sources could inform water management strategies for the communities. Quantitative data obtained from the analysis of water samples collected indicated that the highest levels and occurrence of fecal bacteria were found in the Soufriere watershed while the highest concentrations and occurrence of pesticides were found in the Grand River watershed. In the Grand River watershed, conventional treatment of water followed by activated carbon filtration and UV disinfection removed fecal bacteria and also removed many chemical microcontaminants with efficiencies as high as 98%. Data from both watersheds indicated that there was a strong positive correlation between the levels of caffeine and sucralose (i.e. indicators of wastewater contamination) in water samples and the levels of either Total Coliforms or fecal bacteria of human origin. Human health risk assessments of individual pesticides and pesticide mixtures performed by applying a hazard quotient (HQ) and hazard index (HI) model, respectively indicated that there were no apparent risks to human health from those microcontaminants. Qualitative data obtained from face-to-face interviews with water managers and health professionals working in the two communities, which were collected and analysed concurrently but independently, illustrated that there were cross-cultural similarities and differences in factors influencing the perceptions of risks associated with the sources of drinking water. These perceptions of risks were mainly influenced by factors such as heuristics or informal and informal reasoning, cognitive-affective factors, social-political institutions and cultural factors. These factors may have also influenced water managers and health professionals, as they often recommended more “soft” strategies for managing water resources in the communities. Key words: pesticides, fecal bacteria, microcontaminants, POCIS, measured risks, perceived risks, water management, First Nations, Grand River, Soufriere, St. Lucia Author Keywords: fecal bacteria, measured risks, microcontaminants, perceived risks, POCIS, water management
Assessing effects and fate of environmental contaminants in invasive, native, and endangered macrophytes
Macrophytes play an important role in aquatic ecosystems, and thus are integral to ecological risk assessments of environmental contaminants. In this dissertation, I address gaps in the assessments of contaminant fate and effects in macrophytes, with focus on glyphosate herbicide use for invasive plant control. First, I evaluated the suitability of Typha as future standard test species to represent emergent macrophytes in risk assessments. I concluded that Typha is ecologically relevant, straight-forward to grow, and its sensitivity can be assessed with various morphological and physiological endpoints. Second, I assessed effects from glyphosate (Roundup WeatherMAX® formulation) spray drift exposure on emergent non-target macrophytes. I performed toxicity tests with five taxa, Phragmites australis, Typha × glauca, Typha latifolia, Ammannia robusta, and Sida hermaphrodita, which in Canada collectively represent invasive, native, and endangered species. I found significant differences in glyphosate sensitivity among genera, and all species’ growth was adversely affected at concentrations as low as 0.1% (0.54 g/L), much below the currently used rate (5%, 27 g/L). Third, I assessed the potential for glyphosate accumulation in and release from treated plant tissues. I found that P. australis and T. × glauca accumulate glyphosate following spray treatment, and that accumulated glyphosate can leach out of treated plant tissues upon their submergence in water. Finally, I assessed effects of released glyphosate on non-target macrophytes. I found that P. australis and T. × glauca leachate containing glyphosate residues can stimulate the germination and seedling growth of T. latifolia, but can exert an inhibiting effect on A. robusta, although leachate without glyphosate caused similar responses in both plants. Additionally, I found no negative effects in A. robusta when exposed to glyphosate residues in surface water, or when grown with rhizosphere contact to an invasive plant that was wicked (touched) with glyphosate. My results show that non-target macrophytes can be at risk from glyphosate spray for invasive plant control, but risks can be mitigated through informed ecosystem management activities, such as targeted wick-applications or removing plant litter. Integrating contaminant fate and effect assessments with emergent macrophytes into ecological risk assessments can support the protection of diverse macrophyte communities. Author Keywords: Ecosystem management, Ecotoxicology, Glyphosate, Herbicide, Invasive plant, Species at risk
Assessing the Potential for Contamination of Lakes from Upwelling of Arsenic-Laden Groundwater Through Sediments
A bedrock fracture hosting arsenic (As) contaminated groundwater was suspected to be transported to Ramsey Lake, a drinking water resource for more than 50,000 residents of Sudbury, Ontario. A high resolution, spatial, water quality mapping technique using an underwater towed vehicle (UTV) was used to identify sources of upwelling groundwater into lake water and localize the upwelling As contaminated groundwater vent site. The top 7 cm of lake sediments (in-situ) at this vent site were observed to adsorb 93 % of the dissolved As, thus inhibiting lake water quality degradation from this contaminant source. Sediment samples from this location were used in laboratory experiments to assess the potential for this system to become a source of As contamination to Ramsey Lake water quality and elucidate As(III) fractionation, transformation and redistribution rates and processes during aging. Arsenic speciation is important because As(III) has been shown to be more toxic than As(V). To accomplish this a sequential extraction procedure (SEP) that maintains As(III) and As(V) speciation in (sub)oxic sediments and soils was validated for the operationally defined fractions: easily exchangeable, strongly sorbed, amorphous Fe oxide bound, crystalline Fe oxide bound, and the residual fraction for total As because the characteristics of the reagents required to extract the final fraction do not maintain As species. Batch reaction experiments using sediment spiked with As(III) or As(V) and aged for up to 32 d were sequentially extracted and analysed for As(III) and As(V). Consecutive reaction models illustrate As(III) is first adsorbed to the sediment then oxidized to As(V). Fractionation analyses show As(III) most rapidly adsorbs to the easily exchangeable fraction where it is oxidized and redistributes to the strongly sorbed and amorphous Fe oxide bound fractions. Oxidation of As(III) adsorbed to the amorphous and crystalline Fe oxide bound fractions is less efficient and possibly inhibited. Select samples amended with goethite provide evidence supporting Mn(II) oxidation is catalyzed by the goethite surface, thus increasing As(III) oxidation by Mn(III/IV) complexed with the strongly sorbed fraction. Although As immobilization through groundwater sediment interactions may be inhibited by increased ion activity, particularly phosphate or lake eutrophication, this threat in Ramsey Lake is likely low. Author Keywords: arsenic, fractionation, modelling, redistribution, speciation, water quality mapping

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Format: 2024/03/18