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.
Blood pressure that is 140/90 millimeters of mercury (mm Hg) or greater â documented on two occasions, at least four hours apart â is abnormal. Other signs and symptoms of preeclampsia may include: 1  Excess protein in your urine (proteinuria) or additional signs of kidney problems. 2  Severe headaches. 3  Changes in vision, including temporary loss of vision, blurred vision or light sensitivity. 4  Upper abdominal pain, usually under your ribs on the right side.