Learn the early signs of labor, find out how you'll know labor has started, and know when to call the hospital. Abdominal pain during pregnancy. Find out how to tell when abdominal pain during pregnancy is a sign of a serious problem and how to ease cramps when they're or... Preterm labor and birth.
United States presidential line of succession. From Wikipedia, the free encyclopedia. The presidential line of succession defines who may become or act as President of the United States upon the incapacity, death, resignation, or removal from office (by impeachment and subsequent conviction) of a sitting President or a President-elect.
Ecological succession is the observed process of change in the species structure of an ecological community over time. The time scale can be decades (for example, after a wildfire), or even millions of years after a mass extinction. The community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community. The ÊºengineÊº of succession, the cause of ecosystem change, is the impact of established species upon their own environments.