11.   All study participants receive periodic counseling sessions on safe sex to avoid infection.

12.   All study participants were within normal ranges for all four personality qualities, and none suffered from psychiatric problems, say the researchers.

13.   But over three menstrual cycles, the study participants reported no decrease in the severity of symptoms right before menstruation.

14.   Doctors are obligated to thoroughly educate study participants, but it is entirely up to individuals to determine their own actions, Heyward said.

15.   More than three-fourths of the study participants said their successful weight loss had been prompted by a particular event.

16.   Most study participants had been referred by social service agencies and deemed at risk for contracting the virus that causes AIDS.

17.   Not knowing they needed the vaccines was the most common reason that study participants gave for not getting the shots.

18.   One caveat in the study is that researchers relied on the accuracy of the memory of the study participants to report the frequency of sex and orgasm.

19.   One-third of African-American study participants in these cities were infected.

20.   Other study participants included the University of Colorado at Denver and Yale University in New Haven, Conn.