The object of fascination for most is the DNA molecule. But in solution, DNA, the genetic material that hold the detailed instructions for virtually all life, is a twisted knot, looking more like a battered ball of yarn than the famous double helix. To study it, scientists generally are forced to work with collections of molecules floating in solution, and there is no easy way to precisely single out individual molecules for study.

Researchers at Columbia University Medical Center have uncovered the complex structure of a protein that serves as a central energy gauge for cells, providing crucial details about the molecule necessary for developing useful new therapies for diabetes and possibly obesity. A paper published online today in the journal Science details this structure, helping to explain one of the cell's most basic and critical processes.

The new in-vitro technique pioneered by Dr Amanda Hayes and her UNSW colleagues, Shahnaz Bakand and Chris Winder, directly exposes human cells to airborne toxicants and measures cytotoxic effects. The cells are grown on a porous polyester membrane inside a small diffusion chamber and then exposed to selected toxic air pollutants. After as little as one hour's exposure, they can study cell growth and metabolism, and a range of routine toxicological endpoints.

Scientists at the Virginia Bioinformatics Institute (VBI) report in the Journal of Bacteriology that two alphaproteobacteria lack the universal extra guanylate nucleotide typically found in the transfer RNA molecule tRNAHis. tRNAs are the molecules responsible for decoding sequence information specified by messenger RNA molecules, information which is ultimately encoded by the DNA template.

Four million people die every year from respiratory diseases such as viral influenza. For elderly people in particular, an infection can be dangerous. What is more, the flu vaccine is not as effective with this risk group as it is with younger people. The reason for this is that with age the fire power of the immune system is reduced. Why this is the case is largely unknown. An international EU project led by the University of Bonn is now starting which aims at shedding light on this. Among other things, the researchers want to get a step closer to solving this riddle by examining tens of thousands of blood samples. The objective is also to develop new medicines which largely inactivate the viruses and enable the immune system to deal with the small amount of residual viruses.

Children who sleep more tend to weigh less than children who sleep less, and they are less likely than their counterparts to be overweight five years later. That’s one of the major findings of a new study published in the January/February 2007 issue of the journal Child Development.

Female Antarctic fur seals will travel across a colony to actively seek males which are genetically diverse and unrelated, rather than mate with local dominant males. These findings, published in this week's Nature, suggest that female choice may be more widespread in nature than previously believed and that such strategies enable species to maintain genetic diversity.

At last, neuroscience is having an impact on computer science and artificial intelligence (AI). For the first time, scientists in Tomaso Poggio's laboratory at the McGovern Institute for Brain Research at MIT applied a computational model of how the brain processes visual information to a complex, real world task: recognizing the objects in a busy street scene. The researchers were pleasantly surprised at the power of this new approach.