biophysics, applied mathematics. For the article “Utilizing the information content in two-state trajectories,” by Ophir Flomenbom and Robert J. Silbey, which appeared in issue 29, July 18, 2006, of Proc Natl Acad Sci USA (103:10907–10910; first published July 10, 2006; 10.1073/pnas.0604546103), on page 10908, in the last line of the first full paragraph, right column, “Otherwise, Rx,y < min(nx, Ny)” should read “Otherwise, Rx,y < min(Mx, Ny).” The conclusions of the article are based on the correct equation.
