Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Weakly connected core of the QuitNet network plotted with a spring-embedded algorithm: March 1, 2007–April 30, 2007.
Note. Red dots indicate individuals presumed to be smoking and blue dots indicate abstinent members; the size of the dot is proportional to the time since joining the network. Blue lines connect buddies and yellow lines represent communications in Qmail, the Web site's internal, private messaging system.
