System Identification and Seismic Performance Evaluation of Earth Dams

A system identification technique is developed to provide dynamic properties of earth dams from their seismic records. The technique is utilized to assess the capabilities and limitation of analytical models in terms of dynamic nonlinear constitutive relationships as well as damping. The technique is based on the least square method using Gaussian hypothesis. Earth dams are modeled as a three-dimensional nonhomogeneous visco-elasto-plastic soil structure. The forward problem is solved using a Galerkin-Ritz formulation in which the solution is expanded using basis function, which is selected to be the eigenmodes. The spatial variation of the excitation is considered by using global shape functions defined on the boundary domain to interpolate the input motion on the dam boundaries using recorded motion at discrete locations. The constitutive model is used to accommodate the nonlinear path dependent behavior of the dam material as well as coupling between different constituent of the soil mixture. The model is implemented using Druker-Prager multi-yield surface model and linear Kelvin-Voigt model. Application to instrumented dams, in recent earthquake, showed significant match between the recorded response and the optimal estimated response

Placental pouch closure: a novel, safe and effective surgical procedure for conservative management of placenta accreta

Background: Placenta accreta spectrum (PAS) has become a global problem secondary to the high rate of cesarean delivery (CD). The current study presents an effective surgical procedure (placental pouch closure) for uterine preservation in patients with PAS. Methods: We applied this procedure in sixty cases at a tertiary university hospital between September 2017 and January 2019. We included women who were diagnosed as PAS based on preoperative ultrasound and Doppler evaluation, and who had the desire for uterine preservation. Results: The procedure was successful in almost all cases; the uterus was conserved 98.33 % of participants, with no associated severe maternal morbidities or mortality. In all cases, no additional surgical procedures were needed. The mean blood loss was 1263 ml, and the mean number of units of blood required for transfusion was 2.31 units. Conclusion: Identifying and meticulously closing the placental pouch is a novel surgical procedure for conservative management of PAS. In well-selected cases with the availability of facilities and expertise, the technique could have a place as a safe and effective surgical technique in women presenting with placenta accreta who desire uterine preservation. Trial registration number: NCT03241849. Registered on August 8, 201

Light and electron microscopic studies of Myxobolus stomum n. sp. (Myxosporea: Myxobolidae) infecting the blackspotted grunt Plectorhynicus gaterinus (Forsskal, 1775) in the Red Sea, Egypt

A new myxosporean parasite, Myxobolus stomum n. sp., is described from the oral cavity and lips of the blackspotted grunt Plectorhynicus gaterinus (Forsskal, 1775) in the Red Sea, Egypt. The parasite was observed as tiny aggregates of whitish cysts hardly noticed within the muscles of the oral cavity, especially within the lips. The spores were subspherical and measured 8.5x6.5 μm. Polar capsules were equal, pear-shaped, occupied about half of the spore length and measured 4.4x2.4 μm. Histological evaluation of the infection revealed no significant impact on the host. The ultrastructure of the plasmodial wall and sporogenesis of the present species followed the usual pattern valid for most studied myxosporean species

Myxobolus lubati n. sp. (Myxosporea: Myxobolidae), a new parasite of haffara seabream Rhabdosargus haffara (Forsskal, 1775), Red Sea, Egypt: A light and transmission electron microscopy

A new myxosporean parasite, Myxobolus lubati n. sp., was described from the wall of the intestine of haffara seabream Rhabdosargus haffara (Forsskal 1775), Red Sea, Egypt. Macroscopic plasmodia of about 300 μm diameter were located in the circular muscle layer of the intestine. The spores were ovoid and sometimes ellipsoid and measured 9.8 × 7.2 μm. The shell wall of the spore was thickened at the posterior end and marked with 5-7 sutural markings. Polar capsules were equal and pyriform with three polar filament turns situated in the posterior half of the polar capsule. Polar capsules measured 4.2 × 1.6 μm. Histological evaluation of the infection revealed a slight distention of the intestinal layer of muscularis. Ultrastructure of the plasmodial wall and sporogenesis of the present species followed the usual pattern valid for most studied myxosporean species. © 2006 Springer-Verlag