Dicephalic parapagus twins the Hensels, it was found that each twin controlled one leg. Because of the size of their upper body, the Turkish twins needed a special program of exercises before they could learn to walk. After that, they learned to run and climb stairs without further specialist help, and at age 11 they were going to school with other children. Dicephalic parapagus twins Dicephalic parapagus \ dī-ˈsef-ə-lək \ is a rare form of partial twinning where there are two heads side by side on one torso. Infants conjoined this way are sometimes called "two-headed babies" in popular media. The condition is
There are known knowns management and strategic planning circles. Known unknowns refers to "risks you are aware of, such as cancelled flights..." Unknown unknowns are risks that come from situations that are so unexpected that they would not be considered. "For example, prior to the invention of the personal computer, manufacturers of typewriters probably didn't foresee the risks to their business". Contemporary usage is largely consistent with the earliest known usages. For example, the term was used in evidence given to the British Columbia Royal Commission of Inquiry into Uranium Mining in 1979: The term also appeared in a 1982 "New Yorker" article on