Biomedical Engineering Reference
In-Depth Information
chapter 4.3, by Perelson, Bragg, and Wiegel) to the conceptual (such as formu-
lating quantitative physical theories that capture the properties of intracellular
network structures, illuminate the function of sleep, and are complementary to
the algorithmic principles of the genetic code).
The success of the theory of biological scaling should be viewed as a mere
beginning. By its very nature, the model should be thought of as a zeroth-order
description of "average idealized organisms" that embody the essential features
of biological systems. In the future, more detailed analyses should be performed
that use the theory of biological scaling as a point of departure. Indeed, a major
conceptual challenge presented by our research is, "Why does it work so well?"
Is there some fixed point, or deep basin of attraction that operates within the
general dynamical structure and ensures that, in spite of enormous complexity,
the general features of biological systems are robust against significant perturba-
tions (88)?
In conclusion, our theory offers a comprehensive, quantitative, integrated
explanation for the scaling of many biological rates and times with body size
and temperature. It explains why body size and temperature have such a power-
ful influence on biological structure and function at all levels of organization. As
discussed in ยง3, the theory of biological scaling is already being applied in excit-
ing ways to several biomedical systems, and we are hopeful that it will lead to
important contributions to the biomedical field.
Methods
:
Data for sleep cycle times are from (89), and methods are detailed therein.
Data for body mass are not given in (89), so most values for body mass come
from (90), which is an earlier compilation that (89) draws from heavily. When
masses given in (90) did not correspond to sleep measurements listed in (89), the
values given in (91) were taken, and when the mass could not be found there, we
used the average of the range of values given in (92). Some of the original
sources given in (89) were consulted to determine which species were used. In a
few cases, the logarithmic averages of body masses were calculated for groups
of species (e.g., four species of
Microtus
and five species of
Peromyscus
). This
was done in order to be consistent with the original sleep data in (89).
5.
ACKNOWLEDGMENTS
It is important to recognize that we carried out this work in a close, intense
collaboration between biologists, biochemists, and physicists, and that the re-
search represents an excellent example of successful interdisciplinary science.
We would especially like to thank our collaborators listed on the title page of
