Here's what I found a while back when seeking info about tumor necrosis. 1) Necrosis in the tumor means that the cancer cells in that area are dead. The pathologic finding of necrosis suggests a fast-growing cancer. This often happens because the tumor runs out of blood supply in the central portion. Without a blood supply, the tumor cells cannot live.
Football cleats also come in the removable and molded variety. Molded cleats tend to be less expensive and are often required for youth play for safety reasons. Detachable football cleats are made of rubber, hard plastic or metal and come in a variety of lengths for use on different playing surfaces.
Common modern formations. The following formations are used in modern football. The formations are flexible allowing tailoring to the needs of a team, as well as to the players available. Variations of any given formation include changes in positioning of players, as well as replacement of a traditional defender by a sweeper.