Abscissa and ordinate Abscissa and ordinate In mathematics, the abscissa (; plural "abscissae" or "abscissæ" or "abscissas") and the ordinate are respectively the first and second coordinate of a point in a coordinate system. The abscissa of a point is the signed measure of its projection on the primary axis, whose absolute value is the distance between the projection and the origin of the axis, and whose sign is given by the location on the projection relative to the origin (before: negative; after: positive). The ordinate of a point is the signed measure of its projection on the secondary axis, whose absolute value
Kidney Paired Donation Kidney Paired Donation Kidney Paired Donation (KPD) or Paired Exchange, is an approach to living donor kidney transplantation where patients with incompatible donors swap kidneys to receive a compatible kidney. KPD is used in situations where a potential donor is incompatible. Because better donor HLA and age matching are correlated with lower lifetime mortality and longer lasting kidney transplants, many compatible pairs are also participating in swaps to find better matched kidneys. In the United States, the National Kidney Registry organizes the majority of U.S. KPD transplants, including the largest swaps. The first large swap was a 60 participant chain