Graduate Theses & Dissertations


effects of parasitism on consumer-driven nutrient recycling
Daphnia are keystone consumers in many pelagic ecosystems because of their central role in nutrient cycling. Daphnia are also frequently infected, and the parasites causing these infections may rival their hosts in their ability to regulate ecosystem processes. Therefore, parasitic exploitation of Daphnia may alter nutrient cycling in pelagic systems. This thesis integrates existing knowledge regarding the exploitation of Daphnia magna by 2 endoparasites to predict parasite-induced changes in the nutrient cycling of infected hosts and ecosystems. In chapter 1, I I contextualizing the integration of these themes by reviewing the development of the fields of elemental stoichiometry and parasitology. In chapter 2, we show how the bacterial parasite, Pasteuria ramosa, increased the nitrogen (N) and phosphorus (P) release rates of D. magna fed P-poor diets. We used a mass-balance nutrient release model to show that parasite-induced changes in host nutrient accumulation rates and diet-specific changes in host ingestion rates were responsible for the accelerated nutrient release rates that we observed. In chapter 3, we extended our examination of the nutrient mass balance of infected D. magna to include another parasite, the microsporidian H. tvaerminnensis. We found differences in the effects of these two parasites on host nutrient use as well as support for the hypothesis that parasite-induced changes in Daphnia N release are caused by the effects of infection on Daphnia fecundity. In chapter 4, we examined the relationship between P concentrations and the presence and prevalence of H. tvaerminnensis in rock pools along the Baltic Sea. We found that particulate P concentrations were negatively associated with the prevalence of this parasite, a result that is consistent with the increase in P sequestration of H. tvaerminnensis-infected Daphnia that we observed in chapter 3. I discuss the potential implications of the work presented in chapters 2-4 for other parasite-host systems and ecosystems in chapter 5. Overall, the research presented here suggests that parasite-induced changes in host nutrient use may affect the availability of nutrients in the surrounding environment, and the magnitude of this effect may be linked to parasite-induced reductions in fecundity for many invertebrate hosts. Author Keywords: consumer, ingestion rates, mass-balance, nutrient-recycling, parasitism, phosphorus
evolutionary ecology of Alaska's mountain goats with management implications
The integration of genetic and environmental information can help wildlife managers better understand the factors affecting a species’ population structure and their response to disturbance. This thesis uses genetic techniques to assess the broad and fine scale population structure of mountain goats in Alaska. The first chapter aims to determine the number of genetically distinct subpopulations and model the demographic history of mountain goats in Alaska. The second chapter investigates the population structure and demographic history of mountain goats in Glacier Bay National Park and examines the impact that climate change will have on these mountain goats. My results indicate that Alaska has eight subpopulations which diverged during the Wisconsin glaciation. In Glacier Bay, population structure is reflective of the landscape during colonization, and mountain goat population density and movement corridors are likely to decline due to future climate change. Author Keywords: Alaska, biogeography, gene flow, landscape genetics, mountain goat, population genetic structure
gi-mi-ni-go-wi-ni-nan o-gi-ma-wi-win zhigo o-gi-ma-win (The gifts of traditional leadership and governance)
ni' o-nah-ko-nah ah-di-so-kah-nahg zhigo di-bah-ji-mo-wi-nan g'dah mi-kwe-ni-mah-nahn obwandiacbun (nigig), tecumthabun (mizhibizhi), miinwaa shingwaukbun (ah-ji-jawk) (I ceremonially call upon the stories, the sacred and spiritual narratives and stories of personal experience... In the spirit of obwandiac, tecumtha and shingwauk) gi-mi-ni-go-wi-ni-nan o-gi-ma-wi-win zhigo o-gi-ma-win (The gifts of traditional leadership and traditional governance) explores anishinabe o-gi-ma-wi-win (traditional leadership and to be esteemed) from the point of view of obwandiac (nigig) in 1763, tecumtha (mizhibizhi) and shingwauk (ah-ji-hawk) in 1812 and 1850 respectively. It also examines the political and social significance of anishinabe o-gi-ma-win (traditional governance) and the n'swi-ish-ko-day-kawn anishinabeg o'dish-ko-day-kawn (Three Fires Confederacy) during the time of these esteemed leaders. The use of our ah-di-so-kah-nahg (sacred and spiritual stories), di-bah-ji-mo-wi-nan (stories of personal experience and reminiscences) and ah-way-chi-gay-wi-nan (moral stories) provides the opportunity to show how anishinabe people used different narratives to ah-way-chi-gay-win (teach by telling stories). In listening to these personal and intimate stories we have an opportunity to understand and explore these concepts of o-gi-ma-wi-win (traditional leadership and to be esteemed) and o-gi-ma-win (traditional governance). The first layer to this distinct way of knowing embodies anishinabe nah-nah-gah-dah-wayn-ji-gay-win (how we come to think this way about our reality and epistemology) and is expressed to us within our gah-wi-zi-maw-ji-say-muh-guhk (creation and stories of origin) and miskew ah-zha-way-chi-win (blood memory and the act of flowing). It states explicitly that we have always known where we came from, who we are, and how we fit into this world. anishinabe i-nah-di-zi-win (our way of being and way of life and ontology) lends voice to the second layer of anishinabe kayn-daw-so-win (traditional knowledge), which defines the responsibilities and expectations of anishinabe society, leadership and governance. Our ni-zhwa-sho gi-ki-nah-mah-gay-wi-nan (seven teachings), ni-zhwa-sho o-na-sho-way-wi-nan (seven sacred laws) and the relationship of the do-daim-mahg (clan system) are described within anishinabemowin, the language of our ceremonies and of the jeeskahn (shake tent). Harry Bone (2011)1, an elder from Keeseekoowenin First Nation suggests that ah-zhi-kay-ni-mo-nahd-a-di-sid bay-mah-di-sid (how we use our way of doing, thinking, ceremony and spirituality to find answers and methodology) represents a third layer that provides us with the ways and means to help us understand the essence of anishinabe nah-nah-gah-dah-wayn-ji-gay-win (how we come to think this way about our reality and epistemology and i-nah-di-zi-win (our way of being and way of life and ontology). This represents the literal and metaphoric o-dah-bah-ji-gahn (sacred bundle) and traditional approach that provides this narrative with the means to explore the ideas of leadership and governance from within a traditional construct. He adds that our spirituality and manitou kay-wi-nan (ceremonies) will be clearly defined and shared within this o-dah-bah-ji-ji-gahn (sacred bundle). It helps establish the spiritual core for this narrative. These anishinabe approaches to methodology (intimate conversations, family history and ceremony) are used to tell a story that mirrors the academic construct of interviews and document analysis. Therefore, the o-dah-bah-ji-gahn (sacred bundle) provides the nay-nahn-do-jee-kayn-chi-gayd (to dig around and research) tools to have this discussion exploring the traditional construct of anishinabe o-gi-ma-wi-win (traditional leadership and to be esteemed) and o-gi-ma-win (traditional governance). Lastly, it is important to understand that this traditional approach shows how these narratives are in-and-of-themselves powerful strategies in understanding anishinabe ah-yah-win (way of being and existence) and gah-gi-bi-i-zhi-say-mah-guhk (history). mii i'i-way anishinabe i-zhi-chi-gay-win (This is the anishinabe way) zhigo mii'iw eta-go o-way neen-gi-kayn-dahn zhigo ni-gi-noon-dah-wah (This is as much as I know and have heard) 1 Bone, Harry (Personal Communication) 2011. Author Keywords:
impact of selection harvesting on soil properties and understory vegetation in canopy gaps and skid roads in central Ontario
Tree harvesting alters nutrient cycling and removes nutrients held in biomass, and as a result nutrient availability may be reduced, particularly in naturally oligotrophic ecosystems. Selection harvesting is a silvicultural technique limited to tolerant hardwood forests where individual or small groups of trees are removed creating a “gap” in the forest canopy. In order for harvesting machinery to gain access to these individual trees, trees are felled to create pathways, known as skid roads. The objective of this study was to characterize differences in soil chemical and physical properties in gaps, skid roads and uncut areas following selection harvesting in central Ontario as well as documenting differences in the understory vegetation community and sugar maple (Acer saccharum) seedlings chemical composition post harvest. First year seedlings were collected for elemental analysis from unharvested areas, canopy gaps, and skid roads in 2014, eight months after harvesting. In 2015, first and second year sugar maple seedlings were collected. Soil bulk density and water infiltration were measured in the three areas of the catchment as well as soil moisture, organic matter content, exchangeable base cations, and net nitrification. Seedlings in the disturbed sites had lower concentrations of Mg, K, P, and N compared with unharvested sites and soil nitrification was significantly lower in the skid roads. Water infiltration rates in the gap and skid roads were slower than the control and concentrations of metals (e.g. Fe, Al, Ca) and litter mass increased in litter bags deployed over 335 days, likely reflecting an increase in soil erosion in the skid roads. Understory vegetation was markedly different amongst sites, particularly the dominance of Carex spp. in the skid roads. The sustainability of industrial logging is dependent on successful tree regeneration, however, increased soil compaction, establishment and growth of grasses and shrubs, as well as low nutrient concentrations in seedlings may ultimately restrict forest succession. Author Keywords: Canadian Shield, nitrification, selection harvesting, soil compaction, sugar maple seedling, understory vegetation
influence of tree species litterfall on soil chemistry and implications for modelling soil recovery from acidification
Decades of acidic deposition have depleted base cation pools in soil over large parts of eastern north America, including the Muskoka-Haliburton region of central Ontario. This region has also experienced a shift in forest species composition over the past 200 years, favouring sugar maple (Acer saccharum Marsh.) at the expense of species such as white pine (Pinus strobus L.) and eastern hemlock (Tsuga canadensis (L.) Carr.). This shift in species composition may have changed soil chemistry over time due to differences in nutrient and metal inputs in litterfall. An analysis of litterfall and soil chemistry was conducted for five tree species commonly found across central Ontario. Stands were established in the Haliburton Forest & Wild Life Reserve and were dominated by one of balsam fir (Abies balsamea (L.) Mill.), eastern hemlock, white pine, sugar maple, or yellow birch (Betula alleghaniensis Britt.). Analysis of mineral soil oxides suggested that these stands were established on similar parent material. Deciduous dominated stands (maple and birch) had greater litterfall mass compared with conifer stands (fir, hemlock, and pine), generally leading to greater macronutrient inputs to the soil. Elemental cycling through the organic horizons was more rapid in deciduous stands, with base cations having the shortest residence times. This suggests that a change from greater conifer dominance to mixed hardwood forests may lead to more rapid elemental cycling and alter the distribution of elements in soil. Forests in the region are typically mixed and the resulting differences in soil chemistry may influence model predictions of soil recovery from acidification. Laboratory leaching tests indicated that both stand type and the acidity of simulated rainwater inputs influenced soil solution chemistry, with deciduous stands generally having a greater buffering capacity than sites dominated by coniferous species. Changes in soil chemistry were examined for each stand type using the Very Simple Dynamic (VSD) biogeochemical model. Simulations showed that soil base saturation began to increase following lows reached around the year 2000, and similar patterns were observed for all stands. When sulphur (S) and nitrogen (N) deposition were held constant at present rates, soil base saturation recovery (toward pre-1900 levels) was marginal by 2100. With additional deposition reductions, further increases in base saturation were minor at all sites. In conjunction with additional deposition reductions, the elimination of future forest harvesting allowed for the greatest potential for recovery in all stands. Overall, these results suggest that changes in forest cover may influence soil chemistry over time, most notably in the organic soil horizons. However, forecasted recovery from acidification is expected to follow similar patterns among stands, since differences in soil chemistry were less significant in the mineral soil horizons which compose a greater proportion of the soil profile. Author Keywords: base cation decline, forest harvesting, litterfall, mineral weathering, soil acidification, VSD model
knight and his horse
This thesis examines the social impact of horses on French elites between 1150 and 1300. Using courtly literature, a veterinary treatise, manuscript illuminations, archeological studies, material artefacts, and account books, it explores the place of horses in elite society—practical and symbolic—and assesses the social costs of elite use and ownership of horses. While horses served practical functions for elites, their use and investment in horses clearly went far beyond practicality, since elites used horses recreationally and sought prestigious horses and highly decorated equipment. Their owners used horses in displays of power, status, and wealth, as well as in displays of conspicuous consumption and the performance of gender roles. The social display associated with horses was integrally tied to the ideology and performance of chivalry. This study examines the broader use of horses by elites to understand their place in the elite culture of the High Middle Ages. Author Keywords: Horses, Knighthood, Medieval France, Military History, Nobility, Social History
maskihkîyâtayôhkêwina; mashkikiiwaadizookewin
maskihkîyâtayôhkêwina- mashkikiiwaadizookewin: Cree and Anishnaabe Narrative Medicine in the Renewal of Ancestral Literature Jud Sojourn This work represents an experiment in developing Cree and Anishnaabe nation-specific approaches to understanding Cree and Anishnaabe texts. The binding premise that guides this work has to do with narrative medicine, the concept that narrative arts, whether ancestral storytelling or current poetry have medicine, or the ability to heal and empower individuals and communities. As âtayôhkêwin in Cree and aadizookewin in Anishnaabemowin refer to ancestral traditional narratives, and while maskihkiy in Cree, and mashkiki in Anishnaabemowin refer to medicine, maskihkîyâtayôhkêwina and mashkikiiwaadizookewin mean simply `narrative medicine' in Cree and Anishnaabemowin respectively. After establishing a formative sense for what narrative medicine is, this work continues by looking at the bilingual Ojibwa Texts (1917, 1919) transcribed by William Jones in 1903-1905 on the north shore of Lake Superior and in northern Minnesota Anishnaabe communities, those spoken by Anishnaabe community members Gaagigebinesiikwe, Gaagigebinesii, Midaasookanzh, Maajiigaaboo, and Waasaagooneshkang. Then focus then turns to the bilingual Plains Cree Texts (1934) transcribed by Leonard Bloomfield at the Sweet Grass Reserve in Saskatchewan and spoken by Cree community members nâhnamiskwêkâpaw, sâkêwêw, cicikwayaw, kâ-kîsikaw pîhtokêw , nakwêsis, mimikwâs, and kâ-wîhkaskosahk. The themes that emerge from looking at these texts when combined with an appreciation for the poetics of the Cree and Anishnaabe languages provide the foundation for looking at newer poetry including the work of Cree poet Skydancer Louise Bernice Halfe, centering on the contemporary epic prayer-poem The Crooked Good (2007) and the works of Anishnaabe poet Marie Annharte Baker, focusing on Exercises in Lip Pointing (2003). Each poet emerged as having an understanding her own role in her respective nation as renewing the narrative practices of previous generations. Understandings of the shape or signature of each of the four works' unique kind of narrative medicine come from looking at themes that run throughout. In each of the four works the maskihkîyâtayôhkêwina - mashkikiiwaadizookewin, the narrative medicine they express occurs through or results in mamaandaawiziwin in Anishnaabemowin or mamâhtâwisiwin, in Cree - the embodied experience of expansive relationality. Keywords: Cree, Anishnaabe, nêhiyawêwin, Anishnaabemowin, narrative medicine, traditional stories, poetics, poetry, literary criticism, literary nationalism, Indigenous, indigenist. Author Keywords: Anishnaabe, Anishnaabemowin, Cree, Indigenous, nêhiyawêwin, Poetics
methodological framework for the assessment and monitoring of forest degradation under the REDD+ programme based on remote sensing techniques and field data
In this thesis, a methodological framework for the assessment and monitoring of forest degradation based on remote sensing techniques and field data, as part of the REDD+ programme, is presented. The framework intends to support the implementation of a national Monitoring, Verification and Report (MRV) system in developing countries. The framework proposed an operational definition of forest degradation and a set of indicators, namely Canopy Cover (CC), Aboveground Biomass (AGB) and Net Primary Productivity (NPP), derived from remote sensing data. The applicability of the framework is tested in a sub-deciduous tropical forest in the Southeast of Mexico. The results from the application of the methodological framework showed that the higher rates of forest degradation, 1596-2865 ha·year-1, occur in areas with high population density. Estimations of aboveground biomass in these degraded areas span from 1 to 24 Mg·ha-1, with a rate of carbon fixation ranging from 130 to 246 gC·m2·year. The results also showed that 43 % of the forests of the study area remain with no evident signs of degradation, as detected by the indicators selected, during the period evaluated. The integration of the different elements conforming the methodological framework for the assessment and monitoring of forest degradation enabled the identification of areas that maintain a stable condition and areas that change over the period evaluated. The methodology outlined in this thesis also allows for the identification of the temporal and spatial distributions of forest degradation based on the indicators selected, and it is expected to serve as the basis for operations of the REDD+ programme with the appropriate adaptations to the area in turn. Author Keywords: Forest degradation, Monitoring, REDD+, Remote Sensing, Tropical forest
relationship of policy aims and implementation
Background: Ontario’s Ministry of Health and Long Term Care (MOHLTC) claims people with mental illnesses/addictions need improved care/overuse emergency departments. MOHLTC expects Coordinated Care Planning (CCP, teams of mental/physical health professionals, social workers and informal caregivers) to improve care and lower emergency department returns/healthcare costs. CCPs are directed by policies, Smith’s “problematics,” or Deleuze’s “expressions,” supposedly reflecting “contents”/“everyday worlds.” Research Question: How do Ontario health/allied professionals come together with a person with mental illness/addictions and informal caregiver(s) to address health needs through a CCP? Method: 1) Analyzed CCP policies; generated questions about creation/implementation. 2) Interviewed eight professionals about interpreting/enacting policies. 3) Connected interview data to policies. Findings: Opportunities for fragmentation exist in gaining consent; determining eligibility; persons in care, informal caregivers and professionals’ participation; person-centeredness; “shame-free” environments; health literacy; records of medications. Conclusion: CCP participants need to minimize fragmentations which takes time, space, money; creates contradictions in lowering costs/improving care. Author Keywords: Addiction, Dual Diagnosis, Health Care Policy, Institutional Ethnography, Integrated Health Care, Mental Illness
review of the first- and second-year experience of a group of Trent University students admitted below admission requirements
This study used qualitative research methods to explore the first- and second-year experiences of Trent University students who were admitted below admission requirements in September 2015. Through review of an on-line questionnaire completed by 13 students and two-rounds of semi-structured interviews completed by 5 students, information was gathered on the students’ experiences, specifically regarding self-efficacy for academic achievement, self-efficacy for self-regulated learning, locus of control, student engagement, and sense of belonging. The major findings of this case study were grouped into four driving themes: self-awareness as a learner, goal-setting and motivation, the Trent community, and course experience. Participants of the study felt that the inclusive social and learning environments at Trent University enhanced their sense of belonging within the university community. These findings are not meant to be generalized, as they arose from this specific group of students at Trent University. Author Keywords: first-year experience, locus of control, post-secondary, self-efficacy, sense of belonging, student engagement
role of Cln5 in autophagy, using a Dictyostelium discoideum model of Batten disease
This thesis investigated the role of the neuronal ceroid lipofuscinosis protein, Cln5, during autophagy. This was accomplished by performing well-established assays in a Dictyostelium cln5 knockout model (cln5-). In this study, cln5- cells displayed a reduced maximum cell density during growth and impaired cell proliferation in autophagy-stimulating media. cln5- cells had an increased number of autophagic puncta (autophagosomes and lysosomes), suggesting that autophagy is induced when cln5 is absent. cln5- cells displayed increased amounts of ubiquitin-positive proteins but had no change in proteasome protein abundance. During the development of cln5- cells, fruiting bodies developed precociously and cln5- slug size was reduced. Lastly, when cln5- cells were developed on water agar containing ammonium chloride (NH4Cl), a lysosomotropic agent, the formation of multicellular structures was impaired, and the small slug phenotype was exaggerated. In summary, these results indicate that Cln5 plays a role in autophagy in Dictyostelium. The cellular processes that regulate autophagy in Dictyostelium are similar to those that regulate the process in mammalian cells. Thus, this research provides insight into the undefined pathological mechanism of CLN5 disease and could identify cellular pathways for targeted therapeutics. Author Keywords: Autophagy, Batten disease, Cln5, Dictyostelium discoideum, NCL
role of corticosterone in breeding effort and reproductive success in tree swallows
Glucocorticoids (e.g., corticosterone (CORT)) are hypothesized to mediate decisions regarding reproductive investment during breeding, but the directionality of the relationship is not clear. The CORT-fitness hypothesis posits that high levels of CORT arise from challenging environmental conditions in which an individual will conserve resources for future reproduction or self-maintenance, and thus result in lower reproductive success (a negative relationship). In contrast, the CORT-adaptation hypothesis suggests that, during energetically demanding periods, CORT will mediate physiological or behavioural changes that result in increased reproductive investment and success (a positive relationship). Inconsistencies arise due to the various species and life-history stages studied, and the complex interactions between fitness and glucocorticoids. Using an experimental approach, I investigated the relationship between CORT and reproductive success by manipulating baseline CORT levels in female tree swallows Tachycineta bicolor prior to laying using silastic implants. Implants failed to raise CORT levels of females during either incubation or the nestling stage, and maternal treatment had no effect on indices of fitness at either stage. Using a correlative approach, partial support for the CORT-adaptation hypothesis was found: There was a positive relationship between CORT and hatching success. This only occurred when CORT was measured during incubation, when baseline CORT levels may stimulate increased reproductive effort and success. In contrast, during the nestling stage baseline CORT levels were not related to reproductive investment or success. Maternal CORT levels during incubation also did not influence nestling phenotype, although nestling stress CORT levels were higher in individuals that survived to fledging. In conclusion, CORT mediates reproductive effort and success during some breeding stages, but it is still unclear why this is the case and whether this same pattern will prevail in other contexts. Author Keywords: corticosterone, HPA axis, maternal effects, reproductive success, tree swallow


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