Termites and fungi already know how to digest cellulose, but the human process of producing ethanol from cellulose remains slow and expensive. The central bottleneck is the sluggish rate at which the cellulose enzyme complex breaks down tightly bound cellulose into sugars, which are then fermented into ethanol.

When a person's under stress or injured, the adrenal gland releases cortisol to help restore the body's functions to normal. But the hormone's effects are many and varied, lowering the activity of the immune system, helping create memories with short-term exposure, while impairing learning if there's too much for too long. Given the variety of its effects,understanding how cortisol is made is essential to producing medications that can alter its production.

Friedreich's ataxia is one of those diseases few have heard of unless you know someone with the condition. For that individual -- usually a child or teenager -- it is devastating. Symptoms are mild at first: muscle weakness in the arms and legs, vision impairment and slurred speech, but eventually the symptoms progress and most patients become wheelchair-bound and succumb to heart failure later in life. There is no cure at this time, but Mayo Clinic researchers have identified mutations in an enzyme that may contribute to the disease.

The U.S. Food and Drug Administration (FDA) has caused an unnecessary scare about some pain relievers by adding a warning to drugs that are safe, says Curt Furberg, M.D., Ph.D., from Wake Forest University School of Medicine. At the same time, he says the agency has failed to recognize the harm of a pain reliever that should be taken off the market.

A research team led by the University of Exeter has discovered that, after laying their eggs, sea turtles travel hundreds of miles to feed at exactly the same sites. The research, funded by the Natural Environment Research Council (NERC), shows for the first time that marine turtles appear to be as loyal to specific foraging sites and migratory routes as they are to nesting sites. Published today (25 April) in the journal Proceedings of the Royal Society B: Biological Sciences, the findings strengthen the argument for the protection of key foraging sites of these endangered species.

Identification, isolation and large scale culture of stem cells for potential medical applications is a major challenge in cell biology. In an upcoming PLoS ONE paper, researchers, including Andras Paldi, in Genethon (Evry, France) report, on the basis of experimental observations and computer simulations, that the stem cell identity in culture may strongly depend on the cellular microenvironment.

Each reservoir contains a different base or 'letter' in the DNA alphabet. When activated, an acoustic membrane located underneath the membrane aims a tiny droplet of the desired letter to a point above the center of the array, to the surface of a slide (not shown) successive activations build up a DNA sample on the slide. Credit: USC Ming Hsieh, department of electrical engineering A University of Southern California researcher who with his team won a prize last year for demonstrating a new way to create DNA microarrays has improved the technique to make it much more powerful.