Neurobiologists have discovered a mechanism by which the constantly changing brain retains memories—from that dog bite to that first kiss. They have found that the brain co-opts the same machinery by which cells stably alter their genes to specialize during embryonic development.

Courtney Miller and David Sweatt reported their findings in the March 15, 2007 issue of the journal Neuron, published by Cell Press.

Their studies aimed at exploring whether a process called DNA methylation plays a role in forming memories. In this process, molecules called methyl groups are attached to genes, which switches them off.

Scientists have discovered that the clouded leopard found on the islands of Borneo and Sumatra is an entirely new species of cat. The secretive rainforest animal was originally thought to be the same species as the one found in mainland Southeast Asia.

Genetic analysis conducted at the U.S. National Cancer Institute shows that the difference between the two clouded leopard species is comparable to the differences between other large cat species like lions, tigers, and jaguars.

Video evidence that an extinct woodpecker is alive and well in Arkansas, USA may prove to be a case of mistaken identity. Research published today in the open access journal BMC Biology shows how fleeting images thought to be the Ivory-billed Woodpecker Campephilus principalis could be another native woodpecker species.

J. Martin Collinson compared David Luneau's Arkansas video footage from April 2004 of the supposed Ivory-billed Woodpecker with fresh footage of the Pileated Woodpecker Dryocopus pileatus, a superficially similar black and white species. The Pileated Woodpecker's wings were thought to beat more slowly that the 8.6 beats per second captured on Luneau's video, and its wings have black trailing edges.

The success of long term hip replacement surgery may lie in the genes, suggests research published ahead of print in the Annals of the Rheumatic Diseases.

The researchers analysed genetic variations in 312 people, just over half of whom (162) had problems after hip replacement in the 10 years following surgery.

Among those with symptoms, 91 had early signs of “aseptic loosening,” which describes a condition in which the artificial joint comes loose and the surrounding bone begins to dissolve.

Ultrasound-based tests allowing women undergoing in-vitro fertilization (IVF) to count their chickens before they've hatched may provide alternatives to the hormone-based tests used today. Less costly and invasive than the current ovarian reserve tests, clinicians may in future consider using ultrasound scans of a woman's ovaries to predict her ovaries' response to IVF.

Research published today in Reproductive Biology and Endocrinology details how Janet Kwee et. al. from Vrije Universiteit Medical Centre in Amsterdam, The Netherlands studied 110 women aged 18-39 who had difficulty conceiving. She counted the number of antral follicles, small egg-bearing ovarian follicles about 2-10 mm in diameter, with transvaginal sonography (ultrasound).

For the first time, scientists of the BaBar experiment at the Department of Energy's Stanford Linear Accelerator Center (SLAC) have observed the transition of one type of particle, the neutral D-meson, into its antimatter particle. This observation will now be used as a test of the Standard Model, the current theory that best describes all the universe's luminous matter and its associated forces.