This downward spiral may have been exacerbated by Europe's efforts to cut the value of Greek sovereign debt without triggering a payout on credit-default-swap contracts.

Today, more than 500 000 are afflicted by yaws, which is caused by a spiral bacteria that penetrates through a cut in the skin resulting in bumps that burst, ulcerate and spread over the body.

Integral spiral heavy weight drill pipe is to extend the central upset of heavy weight drill pipe and to cut spiral groove on heavy weight drill pipe.