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 a rare disorder passed from parents to child. In the most common form, a baby about 6 months old will begin to show symptoms. Tay-Sachs disease results when an enzyme that helps break down fatty substances is absent. These fatty substances build up to toxic levels in the child's brain and affect the nerve cells. As the disease progresses, the child's body loses function, leading to blindness, deafness, paralysis and death. There is no cure for Tay-Sachs disease. Gene therapy or enzyme replacement therapy research may eventually lead to a cure or treatment to slow the progression of Tay-Sachs disease.