A team of scientists from Texas A&M University and The University of Glasgow Veterinary School in Scotland has discovered that naturally occurring endogenous retroviruses are required for pregnancy in sheep.

A study of 14 Swedish amateur boxers suggests that they have higher levels of certain chemicals in their cerebrospinal fluid in the days following a bout, indicating injuries to neurons and other cells important to brain function, according to a report in the September issue of Archives of Neurology, one of the JAMA/Archives journals.

Giant tortoises at the Darwin Station on Isla Santa Cruz in the Galápagos Islands. The notion of islands as natural test beds of evolution is nearly as old as the theory itself. The restricted scale, isolation, and sharp boundaries of islands create unique selective pressures, often to dramatic effect. Following what's known as the "island rule," small animals evolve into outsize versions of their continental counterparts while large animals shrink.

The much-publicized "ABC" approach to HIV prevention continues to be mired in controversy, partly because of its focus on abstinence-only sex education programs over condom promotion, a focus that pits political and religious conservatives against their liberal counterparts. Nevertheless, the ABC approach is sometimes credited as being responsible for Uganda's dramatic decline in HIV rates. A provocative debate in PLoS Medicine considers the two sides to the question of whether the ABCs are helpful or harmful in the battle to control the HIV pandemic.

Eliminating the need for costly insulin injections for diabetics, regenerating heart muscle after it fails, and improving resistance to disease by engineering immune cells top a list of 10 potential breakthroughs for health in developing countries seen emerging from the new world of regenerative medicine, according to a study published today in the prestigious journal Public Library of Science (PLoS) Medicine.

The SARS virus set alarm bells ringing across the world when it first appeared in 2002, but now a review of the effectiveness of the treatments used against it has found no evidence that any of them worked. The review was commissioned by the World Health Organization and has been published in PLoS Medicine.

The onset of the flu season in the USA has been shown to be influenced by air travel. After flights were restricted following the 9/11 terrorist attacks in 2001, the flu season started about two weeks later than usual.