Human nerve stem cells transplanted into rats' damaged spinal cords have survived, grown and in some cases connected with the rats' own spinal cord cells in a Johns Hopkins laboratory, overturning the long-held notion that spinal cords won't allow nerve repair.

A report on the experiments will be published online this week at PLoS Medicine and "establishes a new doctrine for regenerative neuroscience," says Vassilis Koliatsos, M.D., associate professor of neuropathology at Johns Hopkins.

Just as homes have smoke detectors, cells have an enzyme that responds to a buildup of fatty acids by triggering the production of a key molecule in the biochemical pathway that breaks down these fatty acids, according to investigators at St. Jude Children's Research Hospital. This breakdown of fatty acids, in turn, provides the cell energy while reducing the chance that excess fatty acids will accumulate.

The St. Jude discovery explains how the fatty acid-sensing enzyme PanK2 tailors production of this key molecule, coenzyme A (CoA), to the cell's energy demands. Understanding PanK2 function is also important because mutations in this enzyme cause an inherited neurodegenerative disease.

How do you get information from a preparation that is transparent? How can you still see a three-dimensional image through a microscope? Dutch researcher Rajesh S. Pillai investigated a new way of illuminating preparations under the microscope. For example, he could investigate the microstructure of food, which is important for the taste and shelf-life. Furthermore, this technique is highly promising for research into how fat is stored in the human body.

A blow with the hammer

Images can only be made under the microscope if the preparation is illuminated. Sometimes using a single lamp is not enough, for example when a three-dimensional image of a transparent sample is needed. In this project Pillai used a laser that emitted extremely short pulses of infrared light.

The rise of multicellular animals about 540 million years ago was a turning point in the history of life. A group of Finnish scientists suggests a new climate-biosphere interaction mechanism for the underlying processes in a new study, which will be published on February 14, 2007 in PLoS ONE, the international, peer-reviewed, open-access, online publication from the Public Library of Science (PLoS).

The theory invokes cold, ice-containing climates as a key precursor for multicellular life. If the model turns out to be correct, one can assume that complex life might exist also around stars which are more massive and short-lived than the Sun.

New research findings now appearing online in the Journal of Experimental Social Psychology began with a professor's desire to understand why her husband often seemed to ignore her requests for help around the house.

"My husband, while very charming in many ways, has an annoying tendency of doing exactly the opposite of what I would like him to do in many situations," said Tanya L. Chartrand, an associate professor of marketing and psychology at Duke University's Fuqua School of Business.

When Chartrand envisioned a formal academic study of people's resistance to the wishes of their partners, parents or bosses, her husband, Gavan Fitzsimons, became not only her inspiration, but also her collaborator.

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.