Oceanic lithosphere is continuously formed at a constant rate at the mid-ocean ridges 1 0 = 0. Thus at x = 0 the temperature is the Heaviside step function. Finally, we assume the system is at a quasi-steady state, so that the temperature distribution is constant in time, i.e. T=T(x,z).
Because preeclampsia can prevent proper blood flow to the placenta, babies may be born prematurely and can suffer from later conditions such as learning disabilities, epilepsy and hearing and vision problems.
Several preexisting maternal characteristics increase the risk of preeclampsia, including hypertension, reduced renal function, obesity, insulin resistance, diabetes, and a history of preeclampsia in a previous pregnancy, particularly if it occurred preterm (prior to 34 weeks gestation).