Ventana software support forum

I tried for several years to obtain neuroscience grant funding which
included a promising and innovative (I thought) use of SD to interpret drug
diffusion throughout the brain after microinjections in mice. As expected,
the reviewers were not familiar with SD, there is little biomedical track
record (largely because they wont fund the research . . . ), and it was
not funded.

But I kept at it. In the final attempt, after re-reading JWFs description
of model validity (described above), I paraphrased and quoted liberally to
indicate as clearly as possible the strengths and weaknesses of the
modeling approach. This grant was funded! Although I had made iterative
improvements with each submission and probably wore them down, I believe
this conceptual information played a key role in convincing the reviewers
that modeling and simulation, carefully done, can contribute significantly
to our growing understanding of such processes.

Furthermore, JWF wrote a description of systems analysis which compared new
engineering design (e.g. new airplane; modeling; testing; refining design
to meet specs, etc.) with socio-economic modeling which uses feedback
concepts to help solve difficult societal problems. (I dont have the D-##
at my fingertips). Socio-economic problems cannot be experimented on very
reliably; next year we may have a different president, interest rates,
balance of trade, public opinion, etc. etc.

>From my perspective JWF omitted another important viewpoint (but of course
this viewpoint is much more relevant to me as a biomedical researcher).
That is, I can model an existing, but poorly understood system, reliably
and repeatedly in the laboratory. Therefore I can develop a growing
understanding about the structure and function of the system, confirmed
with reliable data.

I can build a model of a homeostatic system (e.g. thermoregulation), and
then compare its performance with a genetically constant lab mouse.
Furthermore, I can control environmental conditions very closely. Will the
model act just like the mouse? Very doubtful, because our mental models of
biological processes remain fuzzy.

BUT: I can revise the model (based on rational SD concepts and rigorous
attention to experimental details) and repeat the experiment -almost
exactly- in another mouse next month, or next year, or in another
laboratory. -This cannot be accomplished with socio-economic models!-

Therefore, the application of SD to biomedical systems offers a tremendous
opportunity for new knowledge. In contrast to modeling physical systems
which we already understand (i.e. for teaching purposes; pendulums, cooling
cup of coffee), we are modeling a reasonably stable, repeatable system
about which we have a lot to learn. I suggest that this approach will
indeed lead to predictions about mouse thermoregulation which would
otherwise have been difficult or impossible.

We have recently been informed in these discussions (again) about several
biological models developed by SD students (diabetes, menstrual cycle), and
I applaud this work. But I am really waiting (and pushing) for the time
when these models are developed by the biomedical researchers themselves,
within their own laboratories. These models, and the modeling process,
should be an integral part of the weekly lab meeting, experimental design,
interpretation, and teaching. It should become difficult to obtain a
research grant that does -not- utilize modeling, rather than the other way
around.

Ed Gallaher, Ph.D.
From: Ed Gallaher <gallaher@teleport.com>
Assoc. Prof. Behavioral Neuroscience and Physiology-Pharmacology
Oregon Health Sciences University
Portland, OR