Researchers have discovered an unexpected reservoir of monocytes in the spleen and found that these cells are essential to recovery of cardiac tissue in an animal heart attack model.

A higher density of blood vessels and other unique physiological features in the flight muscles of bar-headed geese allow them to do what even the most elite of human athletes struggle to accomplish -- assert energy at high altitudes.

The mechanism used by "natural killer" immune cells in the human body to distinguish between diseased cells, which they are meant to destroy, and normal cells, which they are meant to leave alone, has been revealed in new detail.

What's so great about sex? From an evolutionary perspective, the answer is not as obvious as one might think. A new article suggests that sex may have evolved in part as a defense against parasites.

The effects of amphetamines on gene expression in zebrafish have been uncovered. A new study provides clues to the genetics that underlie susceptibility to addiction by describing the nad zebrafish mutant, which does not feel the rewarding effects of the drugs.

An odd songbird with a bald head living in a rugged region in Laos has been discovered. Dubbed the "Bare-faced Bulbul" because of the lack of feathers on its face and part of its head, it is the only example of a bald songbird in mainland Asia, according to scientists.

Comets have contained vast amounts of liquid water in their interiors during the first million years of their formation, a new study claims. The watery environment of early comets, together with the vast quantity of organics already discovered in comets, would have provided ideal conditions for primitive bacteria to grow and multiply, experts argue.

A study led by scientists in Austria suggests that kids as young as 9 years old can and should learn how to use CPR (cardiopulmonary resuscitation) and other life support skills and found that even when tested four months after training they retain a good level of knowledge and skill.

Pregnant women are among the groups that should receive H1N1 (swine) flu vaccinations this fall, according to the Advisory Committee on Immunization Practices panel whose recommendations are generally accepted by the Centers for Disease Control and Prevention.

Inter Press Service examines several civil society organizations' argument that legislative measures aimed at fighting HIV/AIDS, "hurt more" than they "help." There are 58 countries with laws in place to "prosecute HIV transmission" and 33 others where such legislation is being considered, according to the International Planned Parenthood Federation.