The far-reaching influence of Spanish and Portuguese colonisers appears not to have extended to South American agriculture, scientists studying a 1,400-year-old Andean mummy have found.

The University of Manchester researchers compared the DNA of ancient maize found in the funerary offerings of the mummy and at other sites in northwest Argentina with that grown in the same region today.

Surprisingly, they found both ancient and modern samples of the crop were genetically almost identical indicating that modern European influence has not been as great as previously thought.

Scientists using data from the HRSC experiment onboard ESA's Mars Express spacecraft have produced the first 'hiker's maps' of Mars. Giving detailed height contours and names of geological features in the Iani Chaos region, the maps could become a standard reference for future Martian research. The maps are known as topographic maps because they use contour lines to show the heights of the landscape.

In work that could dramatically boost the capabilities of "lab on a chip" devices, MIT researchers have created a way to use tiny bubbles to mimic the capabilities of a computer.

The team, based at MIT's Center for Bits and Atoms, reports that the bubbles in their microfluidic device can carry on-chip process control information, just like the electronic circuits of a traditional microprocessor, while also performing chemical reactions. The work will appear in the Feb. 9 issue of Science.

Although no two brains are alike, they can display a comparable pattern of neural activity when exposed to similar sensory input. Scientists at the Max Planck Institute for Dynamics and Self-Organization in Göttingen have now developed a mathematical method to design networks from neural cells which exhibit a predefined pattern dynamics. The researchers hope that their method will assist them in getting closer to understanding which of the possible network configurations was privileged by evolution -- and why (Physica D: Nonlinear Phenomena, December, 2006).

For cells that hold so much promise, stem cells' potential has so far gone largely untapped. But new research from Rockefeller University and Howard Hughes Medical Institute scientists now shows that adult stem cells taken from skin can be used to clone mice using a procedure called nuclear transfer. The findings are reported in the Feb. 12 online edition of the Proceedings of the National Academy of Sciences.

The Scripps Research team, led by neuroscientists Manuel Sanchez-Alavez and Tamas Bartfai, discovered that mice genetically altered to lack a molecule known as the EP3 receptor tend to be more active during their normal sleep cycle and to eat more. In the study, this led to weight increases of up to 30 percent relative to mice with the receptors.

The EP3 receptor is one of four types of receptors for prostaglandin E2 (PGE2), the most important inflammatory mediator that controls a variety of physiological functions including fever, fertility, and blood pressure.