Base excess in the other. A secondary (compensatory) process can be readily identified because it "opposes" the observed deviation in blood pH. For example, inadequate ventilation, a respiratory problem, causes a buildup of CO, hence respiratory acidosis; the kidneys then attempt to compensate for the low pH by raising blood bicarbonate. The kidneys only partially compensate, so the patient may still have a low blood pH, i.e. acidosis. In summary, the kidneys partially compensate for respiratory acidosis by raising blood bicarbonate. A high base excess, thus metabolic alkalosis, usually involves an excess of bicarbonate. It can be caused by A base deficit
Water organ Alexandria (c. 62 AD). Like the water clocks (clepsydra) of Plato's time, they were not regarded as playthings but might have had a particular significance in Greek philosophy, which made use of models and simulacra of this type. Hydraulically blown organ pipes were used to imitate birdsong, and musicologists Susi Jeans and Arthur W.J.G. Ord-Hume have suggested that it was used to create the sounds of the Vocal Memnon. For the latter, solar heat was used to syphon water from one closed tank into another, thereby producing compressed air for sounding the pipes. Characteristics of the hydraulis have been inferred