For example, a certain maize variety grown in a cool climate will need less water per day than the same maize variety grown in a hotter climate. It is therefore useful to take a certain standard crop or reference crop and determine how much water this crop needs per day in the various climatic regions.
An implantable cardioverter defibrillator (ICD) looks very similar to a pacemaker, except that it is slightly larger. It has a generator, one or more leads, and an electrode for each lead. These components work very much like a pacemaker.
The wires attach the generator to the heart. There are two primary types of pacemakers, namely: Standard Pacemaker which sends an electrical impulse via special wires that are attached to the heart. Pacemaker Combination, or Implantable Cardioverter-Defibrillator, as earlier discussed above. This is commonly used in lethal types of heart rhythms.