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.
Why was slavery introduced to the English colonies? Slavery was introduced to the English colonies because people were  in need of labor to develop the lands. There was a lot of work to  be done, and there was little money toâ¦ pay for labor. The human  trade was a solution to the issue. Although, this was not a humane  practice.