Craniopagus twins Craniopagus twins Craniopagus twins are conjoined twins that are fused at the cranium. This condition occurs in about 10–20 babies in every million births in the United States. Among this small group, cephalic conjoining, or craniopagus twinning, represents the rarest of congenital abnormalities, accounting for 2–6% of all conjoined twins. Additionally, conjoined twins are genetically identical and always share the same sex. The union in craniopagus twins may occur on any portion of the cranium, but does not include either the face or the foramen magnum. The thorax and abdomen are separate and each twin has its own umbilicus and
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