Scientists set new temperature record

The hottest temperature ever in the lab has been created - four trillion degrees Celsius - hot enough to break matter down into the kind of soup that existed microseconds after the birth of the universe.

They used a giant atom smasher at the US Department of Energy's Brookhaven National Laboratory in New York to knock gold ions together to make the ultra-hot explosions - which lasted only for milliseconds.

But that is enough to give physicists fodder for years of study that they hope will help them understand why and how the universe formed.

Details of the findings will be published in the journal Physical Review Letters.

"That temperature is hot enough to 'melt' protons and neutrons," says Dr Steven Vigdor.

These particles make up atoms, but they are themselves made up of smaller components called quarks and gluons.

What the physicists are looking for are tiny irregularities that can explain why matter clumped out of the primeval hot soup.

They also hope to use their findings for more practical applications - such as in the field of 'spintronics' that aims to make smaller, faster and more powerful computing devices.

They used the Relativistic Heavy Ion Collider (RHIC), a particle accelerator and collider that is 3.8 kilometre around and buried 4 metres underground to collide gold ions billions of times.

"RHIC was designed to create matter at temperatures first encountered in the early universe," says Vigdor. They calculate the four trillion degree temperature gets pretty close.

"How hot is it?" he asks.

In comparison, "The predicted 'melting' temperature of protons and neutrons is 2 trillion degrees. The temperatures at the core of a typical type-2 supernova is 2 billion degrees," says Vigdor.

The centre of our Sun is 50 million degrees, iron melts at 1800 degrees and the average temperature of the universe is only 0.7 of a degree above absolute zero.

Stem cell capsules to target broken bones

A new way of delivering stem cells could one day lead to a single injection to mend broken or diseased bones and joints, French and Australian scientists say.

Dr Frank Caruso of the Centre for Nanoscience and Nanotechnology at the University of Melbourne and colleagues report their findings this week in the Proceedings of the National Academy of Sciences.

"It is growth factor and stem cells in an injectable format," says Caruso.

"This would be used wherever you would like to regenerate bone."

Bone and joint problems are particularly challenging for medical scientists because bone cells sometimes don't heal themselves very well.

For this reason researchers are exploring ways to effectively transplant stem cells that will regenerate bones and joints.

Caruso and colleagues have designed a capsule made of synthetic polymers, which they have impregnated with growth factors that stimulate the differentiation of stem cells into bone cells.

He says the capsules are very tiny - ranging from about 100 nanometres to tens of microns.

The researchers have then combined these capsules with embryonic stem cells in a matrix of alginate gel. They injected the mixture into lab animals and demonstrated they can stimulate bone regrowth.

If ongoing experiments prove positive, Caruso says the development may lead to treatments in 5 to 10 years.

Are non-smokers smarter than smokers?

Cigarette smokers have lower IQs than non-smokers, and the more a person smokes, the lower their IQ, according to a study of over 20,000 Israeli military recruits.

Dr Mark Weiser and colleagues, from Sheba Medical Center in Tel Hashomer, found that young men who smoked a pack of cigarettes a day or more had IQ scores 7.5 points lower than non-smokers.

"Adolescents with poorer IQ scores might be targeted for programs designed to prevent smoking," conclude Weiser and colleagues in the journal Addiction.

While there is evidence for a link between smoking and lower IQ, many studies have relied on intelligence tests given in childhood.

The studies have also included people with mental and behavioural problems, who are both more likely to smoke and more likely to have low IQs, Weiser and his team say.
Military recruits

To better understand the smoking-IQ relationship, the researchers looked at 20,211 18-year-old men recruited into the Israeli military.

The group did not include anyone with major mental health problems, because these individuals are disqualified from military service.

According to the researchers, 28% of the study participants smoked at least one cigarette a day, around 3% said they were ex-smokers, and 68% had never smoked.

The smokers had significantly lower intelligence test scores than non-smokers, and this remained true even after the researchers accounted for socioeconomic status measured by how many years of formal education a recruit's father had completed.

The average IQ for non-smokers was about 101, while it was 94 for men who had started smoking before entering the military.

IQ steadily dropped as the number of cigarettes smoked increased, from 98 for people who smoked one to five cigarettes daily to 90 for those who smoked more than a pack a day.

IQ scores from 84 to 116 are considered to indicate average intelligence.

Earliest animals flexed their muscles

A group of British and Canadian palaeontologists have found fossils that show the earliest evidence of animal locomotion.

The team from the University of Oxford and Memorial University of Newfoundland, found fossilised trails left by Ediacarans, an enigmatic assemblage of soft-bodied creatures that lived 30 million years before modern animals evolved.

The find, in 565 million-year-old rocks at Mistaken Point in Newfoundland, Canada, appears in the current issue of the journal Geology.

The discovery of 70 fossilised trails, each about 5 to 17 centimetres long, is comparable to the kinds of marks left in the sea floor by modern animals like sea anemones, the researchers say.

Although they can't pin the trails to a specific creature, the discovery shows at least some of the Ediacarans were mobile, and hence must have had muscles.

Similarities in the trails to the modern-day anemone Urticina suggest the organisms that left the fossil traces may have had a muscular 'foot', the researchers say.

"This is exciting because it is the first evidence that creatures from this early period of Earth's history had muscles to allow them to move around, enabling them to hunt for food or escape adverse local conditions and, importantly, indicating that they were probably animals," says University of Oxford PhD student Alex Liu.

The Ediacarans are the earliest complex organisms before the Cambrian 'explosion of life' which marked the development of modern complex life.

But debate continues over just exactly what the Ediacarans looked like, or even what they were.