Causes of Parkinson's disease. Parkinson's disease is caused by a loss of nerve cells in part of the brain called the substantia nigra. This leads to a reduction in a chemical called dopamine in the brain. Dopamine plays a vital role in regulating the movement of the body.
Overnight indexed swap. An overnight indexed swap (OIS) is an interest rate swap where the periodic floating payment is generally based on a return calculated from a daily compound interest investment. The reference for a daily compounded rate is an overnight rate (or overnight index rate) and the exact averaging formula depends on the type of such rate.
Eris is a dwarf planet and a trans-Neptunian object (TNO). It is in the outer Solar System. It is the largest dwarf planet known, even bigger than Pluto, at 2400 km in diameter. Eris is a  scattered disc object  and it is in the Kuiper belt, farther out than Pluto.