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Re: Unidirectional [...] Science
2010/1/15 don ohmes <email@example.com>:
>> Water pressure more a couple of meters would have prevented
>> regardless of respiratory design.
> Yet another unconsidered factor -- sauropods may have been able to create
> pressure oscillations in the airsacs simply by walking, as can penguins.
> J Exp Biol. 2001 Oct;204(Pt 20):3581-6.
> The influence of locomotion on air-sac pressures in little penguins.
> Boggs DF, Baudinette RV, Frappell PB, Butler PJ.
> "... There was no abdominal muscle activity associated with swimming or
> exhalation, but the abdominal muscles were active with the step cycle in
> walking penguins, and oscillations in posterior air-sac pressure
> (0.08+/-0.038 kPa) occurred with steps."
This is an interesting finding. But given that one atmosphere is 101
KPa, the penguins' pressure fluctuations amount to less than one
thousandth of an atmosphere -- which is not going to put a big dent in
the problems of breathing two meters under water.