The specific cause of Parkinsonâs is unknown; however, medical experts believe the symptoms are related to a chemical imbalance in the brain caused by brain-cell death. Parkinson's disease is chronic (persists over a long period of time), and progressive (symptoms grow worse over time).arkinson's disease (or, simply, Parkinson's or PD) is the most common form of parkinsonism, a group of motor system disorders.
Quick Answer. Non-mandatory ZIP codes were introduced to the United States in 1963. Robert Moon, a postal inspector with the United States Postal Service, proposed the ZIP code system as early as 1944. Continue Reading.
Full Answer. The United States Postal Service began using two-digit area codes in 1943 in order to define postal zones in larger cities. Beginning in 1967, the ZIP code became progressively mandatory. The word ZIP comes from the acronym for Zone Improvement Plan.. The original ZIP code was composed of 5 digits.