The Ecology of Urbanization: A Study of Soil Microbial Community Rosponse

Urbanization is associated with global biodiversity loss of macrophauna and flora through direct and indirect mechanisms, but to date few studies have examined urban soil microbes. Although there are numerous studies on the influence of agricultural management on soil microbial community composition, there has been no global-scale study of human control over urban soil microbial communities. This thesis extends the literature of urban ecology to include soil microbial communities by analyzing soils that are part of the Global Urban Soil Ecology and Education Network (GLUSEEN). Chapter 1 sets the context for urban ecology; Chapters 2 addresses patterns of community assembly, biodiversity loss, and the phylogenetic relationships among community members; Chapter 3 addresses the metabolic pathways that characterize microbial communities existing under different land-uses across varying geographic scales; and Chapter 4 relates Chapter 2 and 3 to one another and to evolutionary theory, tackling assumptions that are particular to microbial ecology.

The effect of collagen organization on tensile strength loss in anterior cruciate ligament grafts post-reconstruction surgery

Gemstone Team LEGS

The Effect of Diet-Induced Obesity and Subsequent Weight Loss on Body Composition, Glucose Clearance, Metabolite Profile and Liver Amp-Activated Protein Kinase in Mice

Obesity, currently an epidemic, is a difficult disease to combat because it is marked by both a change in body weight and an underlying dysregulation in metabolism, making consistent weight loss challenging. We sought to elucidate this metabolic dysregulation resulting from diet-induced obesity (DIO) that persists through subsequent weight loss. We hypothesized that weight gain imparts a change in “metabolic set point” persisting through subsequent weight loss and that this modification may involve a persistent change in hepatic AMP-activated protein kinase (AMPK), a key energy-sensing enzyme in the body. To test these hypotheses, we tracked metabolic perturbations through this period, measuring changes in hepatic AMPK. To further understand the role of AMPK we used AICAR, an AMPK activator, following DIO. Our findings established a more dynamic metabolic model of DIO and subsequent weight loss. We observed hepatic AMPK elevation following weight loss, but AICAR administration without similar dieting was unsuccessful in improving metabolic dysregulation. Our findings provide an approach to modeling DIO and subsequent dieting that can be built upon in future studies and hopefully contribute to more effective long-term treatments of obesity.