Project Summary – Comparative Organismal Energetics Core The Comparative Organismal Energetics Core (Organismal Core) provides specialized expertise in the development and utilization of methodologies, state-of-the-art instrumentation and the selection of animal models to facilitate understanding the contribution of energetics to biological aging, including nutritional, genetic, and biochemical interventions that impact aging research. The Organismal Core is a unique resource for investigators, with services and resources not available elsewhere on campus and available to the broader (non-UAB) research community. The Organismal Core is ideally suited to measure energy acquisition, storage, and utilization in a variety of animal models including C. elegans, Daphnia, Drosophila, zebrafish, and rodents, thereby complementing the overall mission and theme of the UAB Nathan Shock Center (NSC). The Specific Aims of the Core are as follows: 1. To provide expertise in the area of energetics and body composition in comparative animal models of aging; 2. To provide state-of-the-art instrumentation and methodology for the determination of body composition across the lifespan (dual energy X-ray absorptiometry, quantitative magnetic resonance, and micro- computed tomography); 3. To provide state-of-the-art instrumentation and methodology for the determination of energy balance across the lifespan (food intake, energy expenditure, energy balance, and activity); 4. To provide state-of-the-art instrumentation and methodology for evaluating healthspan-associated behaviors across lifespan and species; 5. To develop new methodologies for assessing energetics/body composition where needed in current and novel organisms for aging research; 6. To provide education and training on procedures and pitfalls in comparative organismal energetics (both internal and external to UAB).