in the x direction, the water wants to flow in that direction) For a given hydraulic. conductivity, the vertical flow rate depends on the sum of the gravitational potential energy. gradient per unit weight of water (dz/dz =1) and the vertical gradient in soil water pressure.
Origin and spread of the 1278insTATC mutation causing TayâSachs disease in Ashkenazi Jews: Genetic drift as a robust and parsimonious hypothesis. Human Genetics 114 (4): 366â376. pmid 14727180.
Tay-Sachs is a genetic disorder caused by the absence of a vital enzyme known as Hex-A. This missing enzyme causes cells to become damaged, resulting in progressive neurological disorders. The form or type is determined by the age of the individual when symptoms first appear. Only one form of Tay-Sachs occurs in a family. If a child has Infantile, older siblings are not at risk to develop Juvenile or Late Onset Tay-Sachs later in life. 1  Classic Infantile â symptoms appear around 6 months of age.