A provocative new model proposed by molecular biologist John Tower of the University of Southern California may help answer an enduring scientific question: Why do women tend to live longer than men?

That tendency holds true in humans and many other mammals as well as in the much-studied fruit fly Drosophila melanogaster.

In genetic studies of Drosophila, Tower and his team have shown that genes known to increase longevity always affect male and female flies differently.

"For a long time, we only did experiments in one sex or the other, depending on what was convenient," said Tower, an associate professor of biological sciences in the USC College of Letters, Arts & Sciences who has studied the genetics of aging in Drosophila for the last two decades.

How can defense or intelligence agencies safeguard the security of top-secret data protected by a computation device the size of a single molecule?

With cryptography approaching that sobering new era, scientists in Israel are reporting development of what they term the first molecular system capable of processing password entries. Abraham Shanzer and colleagues describe their "molecular keypad lock" in the Jan. 17 issue of the weekly Journal of the American Chemical Society.

Electronic keypad locks long have been fixtures on home security systems and other devices that require a password.

Population science is more art than science so you can count on me to be a little skeptical. However, there are times when the numbers are just too alarming and we have to mobilize for action.

What is this looming population catastrophe? It's Elvis impersonators. Even the Center for Disease Control has sounded the alarm about this issue.  If the CDC is worried about an issue, so am I.

The longest-running search for radio signals from alien civilizations is getting a burst of new data from an upgraded Arecibo telescope, which means the SETI@home project needs more desktop computers to help crunch the data.

Since SETI@home launched eight years ago, the project based at the University of California, Berkeley's Space Sciences Laboratory has signed up more than 5 million interested volunteers and boasts the largest community of dedicated users of any Internet computing project: 170,000 devotees on 320,000 computers.

Yet, new and more sensitive receivers on the world's largest radio telescope in Arecibo, Puerto Rico, and better frequency coverage are generating 500 times more data for the project than before.

A breakthrough in understanding the way atoms move across cell membranes in the human body could pave the way for the development of new treatments for inflammatory diseases such as rheumatoid arthritis.

Scientists at the University of Leeds have identified a previously unknown natural mechanism that opens ion channels – proteins at the cell surface that act as doorways into and out of cells – through the naturally occurring protein thioredoxin.

Ion channels allow movement of ions - electrically charged atoms - across the cell membrane to carry out various functions such as pain transmission, timing of the heart beat, and regulation of blood glucose.

The human brain underwent explosive growth after we split from our chimp cousins, but the pace of evolutionary change among the thousands of genes expressed in brain tissue has since slowed, says a new study in PLOS Biology.

By absorbing half of the carbon dioxide emitted into the atmosphere, the oceans have a profound influence on climate. However, their ability to take up this carbon dioxide might be impaired as a result of climate change. To determine their response to global warming, ESA has backed two projects that provide systematic data on key oceanic variables – colour and temperature.

Plankton bloom off the coast of Norway, acquired on 10 June 2006 by Envisat's MERIS - an instrument optimised to detect ocean colour. (Image courtesy of European Space Agency)

The brain mechanism underlying the mind-bending effects of hallucinogens such as LSD, mescaline, and psilocybin has been discovered by neuroscientists.