Sam Walcott

Postdoctoral Fellow
Mechanical Engineering
Johns Hopkins University

223 Latrobe Hall
3400 N. Charles St.
Baltimore, MD 21218

Email:
scw11 _at_ cornell _dot_ edu

 

 

“Inasmuch ... as biological phenomena are very closely related to physical phenomena, we shall ... whenever possible, look for physical interpretations, in line with the desire to unify all natural sciences.”
              -- Nicolas Rashevsky, 1938.

 

 

 

 

 

 

 

 

 

 

 

(Photo taken by Mac Brown, see more of his work)

 

Research

  

Mathematical and physical biology. Most of my research is focused on providing a quantitatively and physically based understanding of biological systems.  So, for example, how do a molecule’s mechanical properties influence its chemical behavior in a cell?  Can we use the growing number of single molecule measurements to build theoretical models that make physiologically relevant predictions?

Muscle mechanics.  Muscle is a very complex biological system that we happen to know a lot about.  Having done single molecule experiments, I am interested in understanding how these molecular measurements translate to whole muscle contraction.  Therefore, part of my research focuses on creating simple physical and mathematical models of muscle proteins at the molecular level, and then using these molecular-level models to generate cellular-level (and hopefully larger-scale) models.

Biomechanics.  Why do people choose to move the way we do?  Why, for example, do we wind up when we throw?  I build very simple models of these systems to predict coordination through optimization of some cost function (e.g. metabolic cost).  Sometimes, even these simple models can provide counterintuitive results that can help us understand human movement.

Friction mechanics. Micro-mechanics of friction.

Multi-body dynamics. Mechanics miscellany.


Look here for a summary of a talk I gave on throwing mechanics that appeared in Science.

Selected Publications      

To read my most recent postdoctoral journal entry in Nature, please click here.
For a complete list of publications and pre-prints, please look here.

The load dependence of rate constants.
Sam Walcott. Journal of Chemical Physics.
Volume 128, pages 215101, 2008.  PDF.

Enzyme kinetics of muscle glycogen phosphorylase b.
Sam Walcott & Steve Lehman. Biochemistry. Volume 46, pages 11957-68, 2007.  PDF.

Modeling residual force enhancement with generic cross-bridge models.

Sam Walcott & Walter Herzog. Mathematical Biosciences
. Volume 216, pages 172-86, 2008.  PDF.   

Ph.D. Thesis  Understanding movement: a molecular approach.
Sam Walcott, Cornell University, 2006. (Available upon request).

Education and Employment      

For a full CV, please look here.

B.A. Cornell University (General Biology), 2001.

Ph.D. Cornell University (Theoretical and Applied Mechanics, Andy Ruina advisor), 2006.

Post Doc. University of Vermont (Molecular Physiology and Biophysics, Dave Warshaw supervisor), 2006 – 2008.

Post Doc. Johns Hopkins University (Mechanical Engineering, Sean Sun supervisor), 2008 – present.

Past and Current Collaborators (Besides Employers Listed Above)      

Steve Lehman (Integrative Biology, UC Berkeley)

Walter Herzog (Kinesiology, U. Calgary)

Manoj Srinivasan (Mechanical Engineering, Princeton)

Neil Kad (Biology, Essex)

Ned Debold (Kinesiology, UMass Amherst)

Madhusudhan Venkadesan (Applied Math, Harvard)