The water cycle, also known as the hydrologic cycle or the H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go, in and out of the atmosphere.
OBJ: Olusegun Obasanjo (president of Nigeria) OBJ: Official Black Jester (website)
Ureteropelvic junction (UPJ) obstruction is a partial or intermittent total blockage of the flow of urine that occurs where the ureter enters the kidney. The etiology of UPJ obstruction includes both congenital and acquired conditions. UPJ obstruction is the most common pathologic cause of antenatally detected hydronephrosis.