Skin discoloration can be due to changes in melanin. Melanin is a skin pigment that gives color to the skin. Changes in melanin can also cause skin to be patchy. Treatment for skin discoloration includes using topical treatments.
Winglets increase an aircraft's operating efficiency by reducing what is called induced drag at the tips of the wings. An aircraft's wing is shaped to generate negative pressure on the upper surface and positive pressure on the lower surface as the aircraft moves forward.
wing. n. 1. a. One of a pair of movable appendages used for flying, as the feather-covered modified forelimb of a bird or the skin-covered modified forelimb of a bat or pterosaur.. either of the lateral petals of a sweetpea or related flower. b. any of various outgrowths of a plant part, esp the process on a wind-dispersed fruit or seed. 8. a means or cause of flight or rapid motion; flight: fear gave wings to his feet. 9. (Zoology) the act or manner of flying: a bird of strong wing.