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.
The cause of most canker sores is not well understood, and multiple factors may cause sores to appear. Some possible causes of canker sores include the following: Injury to the mouth may cause simple canker sores. Injury could be from vigorous tooth brushing, dental work, braces or dentures, or a sports accident.