Differential fractionation of stable isotopes of carbon during photosynthesis causes C 4 plants
and C 3 plants to have distinct carbon-isotope signatures. In addition, marine C 3 plants …

New treatments for HIV can improve immune functioning and decrease mortality. However,
lapses in adherence may render these complex regimens ineffective. Sixty-three men and 9 …

BACKGROUND AND PURPOSE. Peer norms influence the adoption of behavior changes to
reduce risk for HIV (human immunodeficiency virus) infection. By experimentally intervening …

Sensation seeking, the propensity to prefer exciting, optimal, and novel stimulation or arousal,
is a potential mediating factor in sexual risk for human immunodeficiency virus infection (…

OBJECTIVES. It is critical to extend community-level acquired immunodeficiency syndrome (AIDS)
prevention efforts beyond education alone and to develop models that better …

Basic questions about the life histories of migratory birds have confounded scientists for
generations, yet we are nearing an era of historic discovery as new tracking technologies make …

Background Community-level interventions may be helpful in population-focused HIV prevention.
If members of populations at risk of HIV infection who are popular with other members …

A randomly selected sample of physicians in three large cities was asked to read one of four
vignettes describing a patient. They then completed a set of objective attitude measures …

A series of community-level trials undertaken in the United States over the past 10 years
established the effectiveness of an HIV prevention intervention that systematically identifies, …

Behavior change can curtail the spread of acquired immune deficiency syndrome (AIDS). In
this study, 104 gay men with a history of frequent AIDS high-risk behavior completed self-…