Commodities are raw materials intended for use or consumption. There are three main commodity classifications: Agriculture commodities (often referred to as soft commodities), energy commodities, and metal commodities (referred to as hard commodities). The most commonly traded commodities are crude oil, gold, silver, and copper. Commodity markets can include physical delivery, referred to as a spot contract. Most trades, however, are carried out through derivative trading using futures, forwards, CFD's, and options.
Donna Perrin, RGN, is practice development sister, A&E, Frimley Park Hospital, Surrey. Fluid resuscitation is one of the most important aspects of the acute medical management of critically ill patients.
Water reabsorption is a passive process: water is reabsorbed by osmosis. In most of the nephron, water reabsorption is unregulated and coupled to solute reabsorption.The ability to excrete urine that is more concentrated than the extracellular fluid (ECF) depends on the creation of a hyperosmotic environment in the medulla.As the collecting duct descends through the medulla, the increasing osmolarity in the interstitial fluid drives water reabsorption.he ability to excrete urine that is more concentrated than the extracellular fluid (ECF) depends on the creation of a hyperosmotic environment in the medulla. As the collecting duct descends through the medulla, the increasing osmolarity in the interstitial fluid drives water reabsorption.