Oil and water do mix after all

19:00 19 February 03

Oil and water do not mix - the mantra is familiar to every schoolchild. You have to shake them to overcome the forces that hold the oil together.

Now teachers may want to rewrite their lessons. If you first remove any gas that is dissolved in the water, it will mix spontaneously and even stay that way indefinitely, according to chemist Ric Pashley of the Australian National University in Canberra.

"Many scientists are going to find this very hard to believe," says colloid scientist Len Fisher of the University of Bristol in England, "but Pashley has provided very strong proof that oil and water will mix." Pashley's observation is bound to cause controversy as the reason it happens is still unclear. Chemists are waiting to see whether the experiment can be repeated.

If confirmed, the finding could provide clues to one of chemistry's most puzzling phenomena. This is the so-called long-range hydrophobic force, which causes oil surfaces to attract one another over what to chemists are remarkably long distances.

Read more

Dolly the sheep dies young
17:56 14 February 03 NewScientist.com news service

Dolly the sheep, the first mammal to be cloned from an adult cell, was put down on Friday afternoon, after developing a progressive lung disease.

Dolly's birth six-and-a-half years' ago caused a sensation around the world. But as many sheep live to twice this age, her death will refuel the intense debate over the health and life expectancy of cloned animals.

The type of lung disease Dolly developed is most common in older sheep. And in January 2002, it was revealed that Dolly had developed arthritis prematurely. She was cloned using a cell taken from a healthy six-year-old sheep, and was born on 5 July 1996 at the Roslin Institute, Edinburgh, Scotland.

The Institute's Harry Griffin says: "Sheep can live to 11 or 12 years of age. A full post mortem is being conducted and we will report any significant findings". Following the post mortem, Dolly will be donated to the National Museum of Scotland in Edinburgh, where she will be stuffed and put on display.

Short telomeres

Some cloned mammals, including Dolly, have shorter telomeres than other animals of the same age. These are pieces of DNA that protect the ends of chromosomes and research has shown that they act as molecular clocks, governing the process of ageing in cells.

There have been contradictory studies on the lifespan of cloned animals. In November 2001, US cloning company Advanced Cell Technology (ACT) said a detailed investigation of 24 calf clones revealed that all were normal.

But a study of cloned mice conducted in February 2002 by researchers at the National Institute of Infectious Diseases in Tokyo, Japan, found that they had a shorter lifespan than normal mice.

On 2 February 2003, Australia's first cloned sheep died unexpectedly at the age of two years and 10 months. The cause of death is unknown and the carcass was quickly cremated, as it was decomposing.


Will Knight

Hot plasma may have invaded shuttle - investigators

By Deborah Zabarenko

WASHINGTON (Reuters) - The extreme heat observed on the shuttle Columbia's left side during its fatal re-entry could have been caused by hot plasma penetrating the craft's wheel well, independent investigators said on Thursday.

Plasma is the super-heated gas that surrounded the shuttle as it streaked toward a landing at Kennedy Space Center on Feb. 1. Plasma typically envelops a fast-descending space shuttle, but this time, preliminary analysis indicates it may have gotten inside the spacecraft's protective surface.

"Preliminary analysis by a NASA working group this week indicates that the temperature indications seen in Columbia's left wheel well during entry would require the presence of plasma," the Columbia Accident Investigation Board said in a statement forwarded by NASA.

Read More