Digital Commons Network^™

Tracing Nutrient Sources To Lipid Production In Birds And Insects Using Stable Isotope (Δ13c, Δ2h) Tracers: Implications For Nutritional Physiology Of Migratory Species, Libesha Anparasan

Electronic Thesis and Dissertation Repository

Using stable isotope measurements of inert tissues to determine origins and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, the primary fuel of migration, has not been attempted. I explored isotopic links between diet and stored lipids in captive White-throated Sparrows (Zonotrichia albicollis) and true armyworm moths (Mythimna unipuncta) using δ¹³C and δ²H measurements. Isotopic discrimination between body lipids and diet was established as linear calibration functions. Isotopic uptake following a diet switch in moths was used to trace lipid accumulation over time. Isotopic correlations between breath metabolic …

Exploring The Estimability Of Mark-Recapture Models With Individual, Time-Varying Covariates Using The Scaled Logit Link Function, Jiaqi Mu

Electronic Thesis and Dissertation Repository

Mark-recapture studies are often used to estimate the survival of individuals in a population and identify factors that affect survival in order to understand how the population might be affected by changing conditions. Factors that vary between individuals and over time, like body mass, present a challenge because they can only be observed when an individual is captured. Several models have been proposed to deal with the missing-covariate problem and commonly impose a logit link function which implies that the survival probability varies between 0 and 1. In this thesis I explore the estimability of four possible models when survival …

A Comparative Analysis Of The Restaurant Consumer Food Environment In Rochester (Ny, Usa) And London (On, Canada): Assessing Children’S Menus By Neighbourhood Socio-Economic Characteristics, Catherine Dubreck, Richard C. Sadler, Godwin Arku, Jamie A. Seabrook, Jason A. Gilliland

Human Environments Analysis Lab (HEAL)

Objective:To assess restaurant children’s menus for content and nutritional quality; and to investigate the relationship between the restaurant consumer food environment for children and neighbourhood-level socio-economic characteristics within and between one Canadian city and one US city. Design: Cross-sectional observational study. Setting: London, ON, Canada and Rochester, NY, USA. Participants: Restaurant children’s menus were assessed, scored and compared using the Children’s Menu Assessment tool. We quantified neighbourhood accessibility to restaurants by calculating 800 m road-network buffers around the centroid of each city census block and created a new Neighbourhood Restaurant Quality Index for Children (NRQI-C) comprising the sum of …

Involuntary Hospitalization Among Young People With Early Psychosis: A Population-Based Study Using Health Administrative Data., Rebecca Rodrigues, Arlene G Macdougall, Guangyong Zou, Michael Lebenbaum, Paul Kurdyak, Lihua Li, Salimah Z Shariff, Kelly K Anderson

Epidemiology and Biostatistics Publications

OBJECTIVE: Early psychosis is an important window for establishing long-term trajectories. Involuntary hospitalization during this period may impact subsequent service engagement in people with newly diagnosed psychotic disorder. However, population-based studies of involuntary hospitalization in early psychosis are lacking. We sought to estimate the proportion of people aged 16 to 35 years with early psychosis in Ontario who are hospitalized involuntarily at first admission, and to identify the associated risk factors and outcomes.

METHODS: Using linked population-based health administrative data, we identified incident cases of non-affective psychosis over a five-year period (2009-2013) and followed cases for two years to ascertain …

The Impact Of The Diabetes Management Incentive On Diabetes-Related Services, Hospitalizations, And Mortality Risk In Ontario, Thaksha Thavam

Electronic Thesis and Dissertation Repository

Effective diabetes management provided in primary care has the potential to reduce hospitalizations and mortality. To improve diabetes management, a Diabetes Management Incentive (DMI) was introduced by the Ontario government for family physicians practicing in patient enrolment models. This thesis has three main objectives: 1) review the literature on the association between financial incentives for diabetes care and diabetes-related hospitalizations and mortality; 2) and 3) examine the impact of DMI on: diabetes-related services, diabetes-related hospitalizations, diabetes-related hospitalization costs, and mortality risk in Ontario. A review of the literature on the incentives revealed inconsistent findings. The impact of DMI was assessed …

Incorporating Temperature And Precipitation Extremes Into Process-Based Models Of African Lepidoptera Changes The Predicted Distribution Under Climate Change, Madeleine G. Barton, John S. Terblanche, Brent J. Sinclair

Biology Publications

Terrestrial insects are responding to ongoing climate change. While these responses have been primarily linked to rising temperatures, insects are sensitive to desiccation, and the impacts of altered precipitation regimes remain relatively unexplored. Here, we develop a mechanistic model of survival and performance responses to both temperature and desiccation stress, focussing on Lepidoptera in Africa, where a general understanding of such responses to climate change is urgently required. We run the model with climate data from general circulation models at daily time intervals under current (2011–2015) and projected future (2046–2050) climate scenarios. We first simulate four hypothetical, but typical, Lepidoptera …

Stable Isotopic Characterization Of A Coastal Floodplain Forest Community: A Case Study For Isotopic Reconstruction Of Mesozoic Vertebrate Assemblages, Thomas M. Cullen, Fred Longstaffe, Ulrich G. Wortmann, Mark B. Goodwin, Li Huang, David C. Evans

Earth Sciences Publications

Stable isotopes are powerful tools for elucidating ecological trends in extant vertebrate communities, though their application to Mesozoic ecosystems is complicated by a lack of extant isotope data from comparable environments/ecosystems (e.g. coastal floodplain forest environments, lacking significant C₄ plant components). We sampled 20 taxa across a broad phylogenetic, body size, and physiological scope from the Atchafalaya River Basin of Louisiana as an environmental analogue to the Late Cretaceous coastal floodplains of North America. Samples were analysed for stable carbon, oxygen and nitrogen isotope compositions from bioapatite and keratin tissues to test the degree of ecological resolution that can …