In stochastic processes, chaos theory and time series analysis, detrended fluctuation analysis (DFA) is a method for determining the statistical self-affinity of a signal.
Sore throats caused by tonsillitis or streptococcus may trigger a canker sore even after the initial throat condition has subsided. Also known as an aphthous ulcer, canker sores are painful and unsightly, but they are not contagious.
Canker sores (also called aphthous ulcers) are different than fever blisters. They are small, red or white, shallow ulcers occurring on the tongue, soft palate, or inside the lips and cheeks; they do not occur in the roof of the mouth or the gums. They are quite painful, and usually last five-ten days.