NSF Postdoctoral Fellowship in Biology FY 2015

Rosario Michael V, Durham NC

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2015, Broadening Participation. The fellowship supports a research and training plan in a host laboratory for the Fellow and a plan to broaden participation of groups underrepresented in science. The title of the research plan for this fellowship to Michael Rosario is "From slow stretches to impulsive impacts: does tendon function change with stretch speed?" The host institution for this fellowship is Brown University, and the sponsoring scientist is Dr. Thomas Roberts. The mechanics of how springs work are intuitive; the more you stretch a spring, the more energy you store. Although this explanation describes the general principles of energy storage, it ignores a fundamental fact: the majority of biological structures are sensitive to stretch speed. Furthermore, at slow stretch speeds, a structure that is sensitive to stretch speed dissipates more energy than a structure that isn't. The fellowship research specifically focuses on frog tendons and is determining whether stretch speed affects tendon mechanics enough to play a significant role in tendon function. First, it tests whether sensitivity to stretch speed of frog tendons differs between those used for jumping and those used for landing. Because energy dissipation is directly related to stretch speed sensitivity, lower sensitivity in the jumping tendons (to maximize energy available for movement) is expected than in the landing tendons (to maximize energy dissipated to the environment). The second test is whether a single tendon has the ability to modulate its function via rate of muscle contraction. If stretch speed sensitivity provides a mechanism for context-dependent function, the expected result is that tendon stiffness varies between fast and slow muscle contractions. The results test the prediction that while fast contractions stiffen the tendon, thereby facilitating quick transmission of muscle force, slow contractions reduce tendon stiffness and permit deformation as well as energy storage. An understanding of biomechanical mechanisms has numerous applications in biology and engineering. Training goals include acquiring expertise in both classical skills and modern developments in muscle-tendon physiology. Educational outreach is being provided to undergraduates, graduate students, postdoctoral researchers, and faculty members through computer programming tutorials conducted both at the host institution and online and by forming local and online working groups to discuss topics in scientific computing. The online programming tutorials allow researchers across the country to hone their own computational skills and seek to inspire other biologists to develop a computational mindset in their own research. Special efforts are being made to include undergraduate students from underrepresented groups in these activities.