responders >> rɪˈspɒndə
Definition: [noun] a person who replies to something, especially one supplying information for a questionnaire or responding to an advertisement.
Example: the vast majority of responders indicated that the advertisement was believable
Definition: [noun] a person who reacts quickly or positively to a stimulus or treatment.
Example: the change had already occurred in placebo responders at week one
Definition: [noun] a person trained to respond to and deal with emergencies.
Example: these factors facilitated quick pathways for disaster responders