Myringotomy and tympanostomy, in parallel with the general distinction between an -otomy (cutting) and an -ostomy (creating a stoma with some degree of permanence or semipermanence). In this distinction, only a tympanostomy involves tympanostomy tubes and creates a semipermanent stoma. This distinction in usage is not always made. The word "tympanocentesis" specifies that centesis (aspiration for sampling) is being done. Etymologically, "myringotomy" ("myringo-", from Latin "myringa" "eardrum", + "-tomy") and "tympanotomy" ("tympano-" + "-tomy") both mean "eardrum cutting", and "tympanostomy" ("tympano-" + "-stomy" means "making an eardrum stoma". In 1649, Jean Riolan the Younger accidentally pierced a patient's ear drum while
River incision (Jansen 2006), removing this armoring layer of gravel, boulders, etc. exposes the channel bed to the erosive force of the water. “On the Russian River near Healdsburg, California, instream pit mining in the 1950s and 1960s caused channel incision in excess of 3-6 m over an 11-km length of river” (Kondolf et. al. 2002). Tectonics play an important role in shaping landscapes and rivers, and tectonic uplift and river incision go hand in hand. Over geologic time, as mountains rise higher, water erodes deep gorges and channels, dissecting the landscape. In some instances, such as the Sierra Nevada mountains of