Rheumatoid arthritis (RA) causes premature mortality, disability and compromised quality of life in the industrialized and developing world (1). Rheumatoid arthritis is a systemic inflammatory disease which manifests itself in multiple joints of the body.
A baritone is the most common type of male voice whose range lies midway between the high tenor voice and the low bass voice. In comedic operas, he is often the leader of the funny business, but he can also be the hero, who sacrifices himself for the tenor or soprano, or the villain.
The medium female singing voice in opera and non-classical music (although in the choir, the mezzo-soprano and the contralto are lumped together as altos). The mezzo-soprano has a range of two octaves from A3 (below middle C) to A5 (just two notes short of high C). This is the most common female voice.