Biophysical Society Newsletter - August 2016

18

BIOPHYSICAL SOCIETY NEWSLETTER

2016

AUGUST

Obituary

Bill’s research focused on several areas of central importance to biophysics, where it was clear that the principles of mechanics played a critical part in the underlying biological phenomena. Inspired by his thesis work, Bill established many excit- ing collaborations with experimental groups that examined the mechanical response of viral capsids to mechanical stimuli, such as those imposed us- ing the atomic force microscope (AFM). In these experiments, an AFM tip is used to push on the virus, and Bill and his many collaborators used a combination of analytical thinking and finite- element models to study the mechanical response of the capsids, making detailed comparisons with the results of experimental studies. More recently, Bill pioneered new numerical methods for the application of non-linear elasticity theory to study problems such as the maturation of viral capsids. This led to a better understanding of viral capsids as macromolecular machines that cleverly manage built-in elastic stress. The mechanics of lipid bilayer membranes was another area that enticed Bill. Here too—whether in the context of optical tweezer experiments on membrane tethers or the study of the ordered arrays formed by membrane proteins—he showed how the finite element method could be used as a powerful window onto membrane mechanics. He was also intrigued by networks of cytoskeletal fila- ments and made important contributions to our understanding of the mechanics of networks of stiff protein filaments, with implications for how cells generate and respond to force. One of Bill’s recent growing enthusiasms was the modeling of the human heart. What captured Bill’s imagina- tion in this problem was the interaction between the complex geometry of the heart, its mechanical response, and how these different aspects of the heart dictate cardiac electrophysiology. As all of these examples show, Bill’s mind traveled adventurously across biological phenomena and the length scales at which they occur. Further, his talent and knowledge in attacking hard problems with elegant and transparent numerical methods coupled with his enthusiastic

Bill Klug Quiet Adventurer, Transcendent Human (1976–2016) It is with heavy hearts that we report the terribly premature and tragic death of Bill Klug , a noted practitioner of computational mechanics whose interests centered on biophysical phenomena in contexts ranging from viruses to the human heart. It has been said that “life well lived is long,” but Bill Klug’s incredibly well-lived 39 years were far too short by any measure, regardless of how extraordinarily well lived they were. Bill was a California boy; it was his home from his childhood years through college, graduate school, and where he was now raising his own beautiful young family. As an undergraduate at Westmont College in Santa Barbara, and as a master’s stu- dent at UCLA, Bill had already established two of the great loves of his life, his wife Mary Elise and the use of mathematics as a way to understand and engineer the world around him. As a graduate student at the California Institute of Technology, where he studied with Michael Ortiz , Bill began his first forays into the power of computational mechanics as a way of studying the living world. Bill’s thesis work was inspired by stunningly beau- tiful single-molecule experiments that measured how force builds up inside of viruses as a result of their packaged genomes. Bill took a clever con- tinuum mechanics approach for representing the structure of the packaged DNA permitting him to compute its stored energy. One of Bill’s most impressive attributes — and the basis of how he lived his life in general — is that he was a quiet adventurer. Upon landing a job at UCLA as an assistant professor in mechani- cal engineering, nothing would have been easier than to settle into a productive and even exciting career studying traditional mechanics problems. Instead, both in his teaching and research, he set out to redefine what it means to be a computa- tional mechanician, setting his sights on a quan- titative understanding of the mechanics of living systems, from sub-cellular scales to the scale of human organs such as the heart.

Bill Klug