The various preparations of insulin available for prescription vary in onset, intensity, and duration of action. Animal source insulins, pork and beef, have been discontinued in the U.S. market. Human insulin is derived by recombinant DNA technology and is termed quick acting, intermediate acting, or long acting.
The pole lathe was invented sometime before the 13th century AD. Although it represented a great advance the pole lathe was not that much more complicated than its predecessors. The differences consisted of a framework to raise the bed of the lathe clear of the ground, the addition of a pole and a treadle.
[ The history of hair straightener](http://www.ehow.com/about_5449802_history-hair-straighteners.html)Isaac K. Shero invented a hair straightener that comprises two flat irons that are heated and pressed together. He patented it in 1909. History of the flat iron. history of the flat iron It wasnât until later on in 1912 that the model of flat iron came out that most closely represents the flat irons that you see being sold on the internet and in stores today.