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 in ancient Greek is often imagined as an automatic organ, but there is no source evidence for it. A hydraulis is an early type of pipe organ that operated by converting the dynamic energy of water () into air pressure to drive the pipes (). Hence its name hydraulis, literally "water (driven) pipe (instrument)." It is attributed to the Hellenistic scientist Ctesibius of Alexandria, an engineer of the 3rd century BC. The hydraulis was the world's first keyboard instrument and was the predecessor of the modern church organ. Unlike the instrument of the Renaissance period, which is the main subject