To keep things simple, we only consider the area of each state, twice the area of each state, and the area of the entire USA as units. We only bother with twice statesâ area thing for big countries (larger than 2,500,000 sq km). For compactness, we do not provide the reverse mapping from countries to US states. R code available upon request. Here you are.
Gallstones form from bile, the yellowish fluid that is produced in the liver and stored in the gallbladder until it is released into the small intestine to help in digestion. Bile is a mix of cholesterol, water, pigments, lecithin, and salts (electrolytes), such as calcium, that are kept in equilibrium. Gallstones form when one of the constituents of bile precipitates out and forms a solid mass that may range from the size of a grain of sand to several centimeters large.
The formation of gallstones is a complex process that starts with bile, a fluid composed mostly of water, bile salts, lecithin (a fat known as a phospholipid), and cholesterol. Most gallstones are formed from cholesterol. 1  Bile is important for the digestion of fat.2  It is first produced by the liver and then secreted through tiny channels that eventually lead into a larger tube called the common bile duct, which leads to the small intestine.n such cases, symptoms can develop. 1  In most cases of obstruction, the stones block the cystic duct, which leads from the gallbladder to the common bile duct. 2  This can cause pain (biliary colic), infection and inflammation (acute cholecystitis), or both.