According to NCES 2, only 53 percent of children ages three to five were read to daily by a family member (1999). Children in families with incomes below the poverty line are less likely to be read to aloud everyday than are children in families with incomes at or above poverty.
There is more than hope for people with post-traumatic stress. Recovery can and does occur. Please do not rely on medication alone as it has no power to change the brain permanently. Effective cognitive-behavioral approaches -- which with repetition change the brain -- work in the vast majority of cases.
Solution of the Diffusion Equation by Finite Differences. The basic idea of the finite differences method of solving PDEs is to replace spatial and time derivatives by suitable approximations, then to numerically solve the resulting difference equations. define the grid shown in Figure 1. Figure 1: Grid for our finite difference approximations.