What was my biggest obstacle?
My greatest obstacle was the first semester of medical school. Memorization !! There is little memorization in mathematics or physics, and I had minimal biological preparation for medical school. I really struggled through the first semester. Then it all began to make sense. I then had a basic framework of biological knowledge to build upon; new facts were no longer isolated. (I have shared this with mathematicians entering our biomathematics doctoral program, of whom substantial graduate-level training in a biomedical specialty was required. They had similar experiences. One can have both a "mathematical mind" and a "biological mind.")
How do I make a difference?
Along with excellent collaborators, I have especially enjoyed innovating some interactive graphics software for biomedical applications and developing a doctoral program whose students achieve substantial graduate-level expertise in both mathematics and a biomedical specialty. I also hope that, during the Cold War, along with other scientists, I was able to make a modest contribution to nurturing East-West relationships, in Yugoslavia and via the International Institute for Applied Systems Analysis.
Who was my mentor?
I have had several mentors. In physics at Stanford University, I was privileged to work with Professor Paul Kirkpatrick for my M.S. degree, and Professor W. K. H. Panofsky, for my Ph.D. At the University of Chicago, I had many wonderful mentors during my medical training, and Professor Robert Hasterlik was supportive to my professional development then and thereafter.
How has my career evolved over time?
University of Chicago radiotherapists had just acquired a smaller medical version of the linear electron accelerator I worked on at Stanford for the first production of pi mesons by electrons. Treatment-planning calculations for electron therapy were very time-consuming. In 1958, I heard about a Univac I computer on campus and wrote a machine-language program for electron treatment planning. I explored other computer applications on it then and during the internship.
After the internship, I undertook my internal medicine residency at the University of Chicago on a part-time basis, while accepting a job as Co-Investigator for the new National Institutes of Health-supported Biological Sciences Computation Center. Soon it was clear that I couldn't do both, so I deferred the residency, joined the faculty, and pursued both research and the development of interests in and infrastructure for bringing mathematics and computation into biology and medicine. Among research pursued were model-based studies of stem-cell theory and erythropoiesis, optimal placement of detectors for determining the whole-body content of a labeled substance, and a study on calcium metabolism that employed the latter.
While at Chicago, I was appointed to NIH's Computer Research Study Section, which brought me in contact with pioneers on a variety of frontiers where mathematics, statistics, informatics, and computing were advancing research and design in biology and medicine. I now could see and feel that this indeed was my calling. And so it has remained.
I joined the University of California at Los Angeles's Department of Biomathematics in 1967 and was assistant director, under Wilfred Dixon, of its NIH-supported Health Sciences Computing Facility (HSCF). At HSCF, an innovative operating system developed by Dr. Patricia Britt, the Terminal-Oriented Real-Time Operating System (TORTOS), opened the door to IBM mainframe-empowered interactive graphics applications. My software development and research using the latter addressed such things as cellular modeling related to cancer and hematopoiesis, interactive graphics software and new methods of representation for exploration of complex data sets, interactive parallax (varying the projection of a three-dimensional structure on the screen in correlation with changes in the viewer's head position), and radiation treatment planning (implant, external beam). My radiotherapy collaborator, Dr. Richard Nelson, moved to the East Coast shortly after software was developed here for an intelligent graphics terminal, the IMLAC, to expedite interactions over slow, dial-up telephone lines. I adapted my programs to take advantage of that, and our work together continued.
Around 1973, our faculty undertook the ambitious goal of developing a doctoral program whose graduates would have doctoral-level expertise in a biological specialty, or M.D. training. To aid pursuit of the realistically complex biological modeling that such knowledge enables, substantial graduate mathematics training was required and computing skills, developed. To share in this effort and see the contributions of our graduates has brought great joy.
After the Health Sciences Computing Facility closed, I continued my research in biomedical computing on IBM mainframes and personal computers, including treatment optimization, a graphics system to navigate a richly branched pedigree tree to display both categorical and scalar data for each person, and easy-to-use software for setting up and exploring differential equation models. Only in recent years have interactive graphics software supports attained the sophistication of what was available at HSCF. I now will carry forward some of that work.
Among activities away from the campus, I would select participation on various National Institutes of Health committees and involvement in collaborative programs during the cold war that brought scientists together from both East and West to have been most fulfilling.