Upregulation of glial cell line-derived neurotrophic factor (GDNF) in the rat cochlea following noise. Pharmacologic manipulation of the labyrinth with novel and traditional agents delivered to the inner ear.
Slavery in the United States was the legal institution of human chattel slavery that existed in the United States of America in the 18th and 19th centuries after it gained independence and before the end of the American Civil War.he United States was polarized over the issue of slavery, represented by the slave and free states divided by the MasonâDixon line, which separated free Pennsylvania from slave Maryland and Delaware.
Slavery was introduced to the British colonies in the early 17th century, and enslaved people largely replaced indentured servants as an economic labor force during the 17th century. In the United States, these people would remain in bondage for the entire 18th century and much of the 19th century.