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.
Causes of Canker Sores. 1  Canker sores have many causes. 2  Minor injuries to the mouth can trigger a canker sore. Examples are from a rough food or a hard toothbrush. 3  Food allergies or irritants may also be a trigger. 4  Vitamin deficiencies can also be a cause. A vitamin deficiency can occur if your child is a picky eater.