Polycystic Ovarian Disease: This disease, also commonly known as PCOS, refers to cysts that form from a buildup of follicles. They cause the ovaries to enlarge and create a thick outer covering, which may prevent ovulation from occurring. They are often the cause of fertility problems.
dune. n. A hill or ridge of wind-blown sand. [French, from Old French, from Middle Dutch. ; see dheuÉ- in Indo-European roots .].
Sand dunes form some of the most spectacular and dynamic landforms on the planet. Individual sand granules (grains of sand) accumulate through both water and wind (eolian) transportation, a process known as saltation.ypes of Sand Dunes. Crescent sand dunes, also called barchan or transverse, are the most common sand dune shapes in the world. They form along the same direction as the predominant winds and have a single slipface.