Article of interest to sequence folk

[Brendan McKay]

The current issue of "Science" magazine has the following
article.  Unfortunately you probably can't see it on the
web unless you have a subscription.  http://www.sciencemag.org

Brendan.

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Science, Vol 309, Issue 5736, 909-911 , 5 August 2005

Triangular and Fibonacci Number Patterns Driven by Stress on Core/Shell
Microstructures

Chaorong Li, Xiaona Zhang, Zexian Cao

Fibonacci number patterns and triangular patterns with intrinsic defects
occur frequently on nonplanar surfaces in nature, particularly in
plants. By controlling the geometry and the stress upon cooling, these
patterns can be reproduced on the surface of microstructures about 10
micrometers in diameter. Spherules of the Ag core/SiOx shell structure,
possessing markedly uniform size and shape, self-assembled into the
Fibonacci number patterns (5 by 8 and 13 by 21) or the triangular
pattern, depending on the geometry of the primary supporting surface.
Under proper geometrical constraints, the patterns developed through
self-assembly in order to minimize the total strain energy. This
demonstrates that highly ordered microstructures can be prepared
simultaneously across large areas by stress engineering.