Another problem with an expiratory valve

The avian lung: is there an aerodynamic expiratory valve?

The unidirectional gas-flow pattern through the avian lung is thought to result from 'aerodynamic valves'; support for this hypothesis lies mainly in the failure to find any evidence for anatomical valves. During expiration, air flows from the caudal air sacs through the major exchange area of the lung, the paleopulmonic parabronchi, instead of bypassing the lungs via the intrapulmonary bronchu...

Editorial Valve in Valve Another Milestone for Transcatheter Valve Therapy

The first mechanical heart valve prosthesis, designed by Dr Charles Hufnagel, was implanted to the descending aorta of a 30-year-old woman with severe aortic regurgitation in 1952.1 Eight years after the initial successful prosthetic valve implantation, Dr Harken sutured a prosthetic valve (Starr Edwards Valve) to the aortic annulus after removing the diseased native valve. During the ensuing y...

Valve in valve: another milestone for transcatheter valve therapy.

Differentiating inspiratory and expiratory valve malfunctions.

hyperemia directly after release of the blood pressure cuff. As stated in our article, we did not measure reactive hyperemia but performed our measurements in all groups after 20 min of reperfusion. It is, therefore, unlikely that reactive hyperemia caused the observed differences between groups. We agree that further studies are needed to clarify more the mechanisms of helium preconditioning i...

Another View of the Classical Problem of Comparing Two Probabilities

The usual calculation of the P-value for the classical problem of‎ ‎comparing probabilities is not always accurate‎. ‎This‎ ‎issue arose in the context of a legal dispute which depended on when‎ ‎some written material was written in a diary‎. ‎The problem raises‎ ‎some issues on the foundations of statistical inference.‎