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This study explored two-dimensional (2D) numerical hydrodynamic model simulations of Lake Victoria. Several methods were developed in Matlab to build the lake topography. Old depth soundings taken in smaller parts of the lake were combined with more recent extensive data to produce a smooth topographical model. The lake free surface numerical model in the COMSOL Multiphysics (CM) software was implemented using bathymetry and vertically integrated 2D shallow water equations. Validated by measurements of mean lake water level, the model predicted very low mean flow speeds and was thus close to being linear and time invariant, allowing long-time simulations with low-pass filtered inflow data. An outflow boundary condition allowed an accurate simulation to achieve the lake’s steady state level. The numerical accuracy of the linear measurement of lake water level was excellent.

Background:Regional anesthesia has been the choice of preference for elective cesarean sections. This study was designed to determine whether preoperative administration of 6% hetastarch decreases the incidence of hypotension.Materials and Methods:This study was conducted on 50 nonlaboring American Society of Anesthesiologists class I and II women undergoing elective cesarean section. Patients were randomly divided into two groups and were preloaded either with 1000 ml Ringer's lactate (RL) or 500 ml of 6% hetastarch 30 min prior to the surgery. Spinal anesthesia was performed with patients in the left lateral position and 2 cc (10 mg) of 0.5% of bupivacaine injected into subarachnoid space. Hemodynamic variables (heart rate, noninvasive blood pressure, and SpO2) were recorded from prior to preloading until the recovery from the subarachnoid blockade.Results:Our study showed the incidence of hypotension to be 28% in the hetastarch group and 80% in the RL group. Rescue ephedrine requirements for the treatment of hypotension were significantly less in patients who were preloaded with 6% hetastarch prior to cesarean section. The neonatal outcome, as determined by Apgar scores was good and similar in both groups.Conclusion:Hence, we conclude that 6% hydroxyl ethyl starch is more effective than lactated Ringers solution and that its routine use for preloading prior to spinal anesthesia should be considered.