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 disease is an autosomal recessive genetic disorder, meaning that when both parents are carriers, there is a 25% risk of giving birth to an affected child. As with all genetic disease, Tay-Sachs disease may arise in any generation from a novel mutation, although such mutations are rare.ay-Sachs disease is a rare, inherited disorder. It causes too much of a fatty substance to build up in tissues and nerve cells of the brain. This buildup destroys the nerve cells, causing mental and physical problems.