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.
Answer: A canker sore is a mouth ulcer that can be painful. They are not related to herpes-triggered cold sores and are not contagious. Canker sores show up in the mucous membranes lining the gums, cheeks and tongue and are typically caused by stress, food allergies, poor nutrition or hormonal shifts.