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.
As pre-eclampsia progresses, it may cause: 1  severe headaches. 2  vision problems, such as blurring or seeing flashing lights. 3  severe heartburn. 4  pain just below the ribs. 5  nausea or vomiting. 6  excessive weight gain caused by fluid retention. 7  feeling very unwell. 8  sudden increase in oedema â swelling of the feet, ankles, face and hands.