Shoulder dystocia (SD) is a serious obstetric emergency that occurs when the fetal shoulders fail to deliver after the head has emerged during the second stage of labor. This condition can result in ...

Professor of Mechanics, Washington University, St. Louis, Mo. It's easy to construct finite-element models with errors. And it's just as easy to correct them, when you know how. The first step in a ...

You may have noticed that the rock formations are very different colors. The rock formations on the left are from Red Rock State Park in Texas, and on the right is El Capitan Mountain in Yosemite ...