Reproduction pressures and rising fertility explain why women suffered a more rapid decline in dental health than did men as humans transitioned from hunter-and-gatherers to farmers and more sedentary pursuits, says a University of Oregon anthropologist.

More than 40 million years ago, primates preferred Texas to northern climates that were significantly cooling, according to new fossil evidence discovered by Chris Kirk, physical anthropologist at The University of Texas at Austin.

While paleontologists may scour remote, exotic places in search of prehistoric specimens, Tufts researchers have found what they believe to be the world's oldest whole-body fossil impression of a flying insect in a wooded field behind a strip mall in North Attleboro, Mass.

Brain imaging shows that the brains of teens that use marijuana are working harder than the brains of their peers who abstain from the drug. At the 2008 annual meeting of the American Academy of Pediatrics in Boston, Mass., Krista Lisdahl Medina, a University of Cincinnati assistant professor of psychology, presented collaborative research with Susan Tapert, associate professor of psychiatry at the University of California, San Diego.

The level of PD-1 expression has been proved by recent studies to be positively correlated with the extent of HBV-specific T cell impairments. However, the degree of T cell exhaustion which affects the disease statuses of hepatitis B patients has so far been only evaluated in restricted and small groups of patients between those with established chronicity and subjects with acute HBV infection. Besides, whether levels of PD-1 expression on T cells differ between acute exacerbation of hepatitis B and chronic HBV infected patients is still unknown.

When biologist Ken Catania heard about the peculiar practice of worm grunting practiced in the Apalachicola National Forest in the Florida Panhandle one of his first thoughts was an observation made by Charles Darwin.

Genetics researchers have identified two novel gene locations that raise the risk of type 1 diabetes. As they continue to reveal pieces of the complicated genetic puzzle for this disease, the researchers expect to improve predictive tests and devise preventive strategies.

The gecko's amazing ability to stick to surfaces and walk up walls has inspired many researchers to manufacture materials that mimic the special surface of a gecko's foot. The secret behind the gecko's ability to stick so well is a forest of pillars at the micro-/nano-scale on the underside of the gecko's foot. Because there are so many pillars so close together, they are held tightly to the surface the gecko is walking on by a molecular force called the Van der Waals force. This relatively weak force causes uncharged molecules to attract each other.

Recent research from the Swedish medical university Karolinska Institutet reveals completely new properties of the skin's stem cells – discoveries that contradict previous findings. The studies, which are published in Nature Genetics, show amongst other things, that hair follicle stem cells can divide actively and transport themselves through the skin tissue.