>>35
A bone composing a wing of a bird has sufficient strength and lightness to fly.
The torus ( cavity ) structure of a bone of a wing of a bird is very similar to torus structures of wings and bridges of a plain.
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>>48
If bones and muscles successively work on something, organizations composing those organs adaptively vary depending on applied external forces.
And, they have an inclination to be tougher according to such variations.
Such variations can be regarded as functional adaptations by organizations themselves on self-organizations ( without instructions from the brain ).
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>>49
( • ) One of the functional adaptations simulated with cell-automaton
〈 Rules 〉
A weight is applied to a matter of square cells.
And, a stress generated at each cell is transformed into a numerical value,
if a higher stress is generated at the cell, the strength (＝ Young's modulus) of the cell rises.
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>>50
This model is different from usual models of cellular automaton, the temporal state of each cell is determined by one's own stress namely the whole state of cells rather than cells on both sides.
→ interactions between each part and the whole ( local scale and non-local scale )
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>>51
In an actual living body, if the stress on a part increases due to an applied weight to the part, a substance to strengthen osseous tissues around the part is released.
It's supposed that aging is one of the main factors to lower such a feed-back function, so that an osteoporosis is caused.
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>>52
A bone has a typical porous structure, it contains many cross-links and its density also is high at young generation.
But, because of aging, cross-links are reduced, its density decreases and the strength declines.
As re-modeling contributes to tissue ( organization ) - regeneration, we should pay attention to re-modeling.
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>>53
Here, we should notice that a bone of a wing of a bird has cavity structure, but unexpectedly it has high strength too.
Namely, we must take not only structural viewpoints but also material viewpoints into consideration.
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