Dicephalic parapagus twins complete hearts are present as well, which improves their chances of survival. The total number of arms may be two, three or four. Their prospects are best if no attempt is made to separate them, except in cases where one twin is clearly dying. Dicephalus means two-headed. Parapagus means joined side by side. Dicephalic twins are called: Conjoined twins appear in one in 50,000 to one in 100,000 births. Dicephalic twins represent about 11 percent of all conjoined twins. As late as the 1960s, some medical publications argued that newborn dicephalic twins should not be actively treated or resuscitated. An
TWINS TWINS Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) are a pair of NASA instruments aboard two United States National Reconnaissance Office satellites in Molniya orbits. TWINS was designed to provide stereo images of the Earth's ring current. The first instrument, TWINS-1, was launched aboard USA-184 on 28 June 2006. TWINS-2 followed aboard USA-200 on March 13, 2008. Each instrument consists of an energetic neutral atom imager and a Lyman alpha detector. The ENA imager provides indirect remote sensing of the ring current ions, and the Lyman alpha detector gives a measure of the neutral hydrogen cloud about the Earth, known as