Oxygen on Earth : A long history

Oxygen, key to life on Earth today, began to appear on the planet millions of years earlier than scientists had thought, new research indicates.

An analysis of a deep rock core from Australia indicates the presence of at least some oxygen 50 million to 100 million years before the great change when the life-giving element began rising to today's levels, according to two papers appearing in today's edition of the journal Science.

Previously, the earliest indications of oxygen had been from between 2.3 billion and 2.4 billion years ago when the "Great Oxidation Event" occurred.

The cause of the event is still not known, but before that the atmosphere was dominated by methane and ammonia. Today oxygen makes up about 21 percent of the atmosphere.

The discovery of traces of early oxygen was made in a study of a 3,000-foot-long rock core extracted in western Australia.

"We seem to have captured a piece of time before the Great Oxidation Event during which the amount of oxygen was actually changing -- caught in the act, as it were," Ariel Anbar, an associate professor in Arizona State University's school of earth and space exploration, said in a statement.

The two research teams were led by Alan Jay Kaufman, associate professor of geochemistry at the University of Maryland and Anbar.

Carl Pilcher of the NASA Astrobiology Institute said: "Studying the dynamics that gave rise to the presence of oxygen in Earth's atmosphere deepens our appreciation of the complex interaction between biology and geochemistry. Their results support the idea that our planet and the life on it evolved together."

Source : Daily Herald

Bad sleeping raises risk of heart diseases and sudden attacks.

Researchers say both too much and too little sleep is linked to a doubled risk of fatal cardiovascular disease. Teams from the University of Warwick and University College London examined sleep patterns and death rates among 10,308 civil servants.

They found a doubled risk among those who cut their sleeping from seven to five hours a night compared to those who stuck to seven hours a night.

But the risk was similar for those who increased to at least eight hours.

The research, to be presented to the British Sleep Society, was based on data taken in 1985-88 and on follow up information collected in 1992-93.

The researchers took into account other possible factors such age, sex, marital status, employment grade, smoking status and physical activity.

Once they had adjusted for those factors they were able to isolate the effect that changes in sleep patterns over five years had on mortality rates 11-17 years later.

Those who cut their sleeping from seven to five hours a night had twice the risk of a fatal cardiovascular problem of those who stuck to the recommended seven hours a night - and a 1.7 increased risk of death from all causes.

--Disturbed sleep common

Researcher Professor Francesco Cappuccio said: ""Fewer hours sleep and greater levels of sleep disturbance have become widespread in industrialized societies.

""This change, largely the result of sleep curtailment to create more time for leisure and shift-work, has meant that reports of fatigue, tiredness and excessive daytime sleepiness are more common than a few decades ago.

""Sleep represents the daily process of physiological restitution and recovery, and lack of sleep has far-reaching effects.""

Curiously, the researchers also found that those individuals who increased their sleep to eight hours or more a night were more than twice as likely to die as those who had not changed their habit.

Professor Cappuccio said lack of sleep had been linked to an increased risk of weight gain, high blood pressure and type 2 diabetes.

However, he said the link between too much sleep and poor health was less clear, although he suggested that staying in bed for prolonged periods could be a sign of depression, or, in some cases, cancer-related fatigue.

""Our findings indicate that consistently sleeping around seven hours per night is optimal for health and a sustained reduction may predispose to ill-health.""

--Individual need

Dr. Neil Stanley, a sleep expert from Norwich and Norfolk University Hospital, said while public health messages focused on diet and exercise, people were given very little information about the need to get proper amounts of sleep.

""This study is yet more evidence of the importance of getting sleep, and the right amount of sleep for you,"" he said.

""Sleep need is like height or shoe size: we all have an individual one, and we sleep less or more then there are consequences to pay.""

(Source: BBC)

Scientists to barcode world's species

A group of Canadian scientists is working on an ambitious project to create a global database of up to half a million of the world's species using DNA barcoding technology.

The scientists are hoping to raise $150 million to fund an initial five-year stage of what they describe as the biodiversity equivalent of launching a rocket to the moon.

DNA barcoding, a technique for characterising a species using only a short DNA sequence, has wide-ranging implications for health and environment.

It could help remove illegal fish and timber supplies from global markets, get rid of pests such as mosquitoes and even reduce the numbers of collisions between birds and planes.

Paul Hebert, head of the Canadian Centre for DNA Barcoding, is spearheading the plan. “We're now trying to launch in Canada the International Barcode of Life Project, which has a five-year life span,” Hebert said at a three-day seminar on DNA in Taipei.

“We hope to put $150 million into this through a 25 Nation Alliance.”

“The idea is collectively we would gather five million specimens and 5,00,000 species within that five-year period,” Hebert added, saying the entire project could take 15 years.

The seminar in Taipei has brought together 350 scientists from 45 countries to debate the “barcoding of life” concept.

Scientists estimate that while nearly 1.8 million species have already been identified, there may be another 10 million that are not known.

But DNA barcoding technology has progressed so rapidly that scientists predict science fiction-style powers to recognise previously unfamiliar creatures could become reality in a decade.

“Like in the film of Star Trek, anything scanned by such devices could display its image, name and function,” said Allen Chen from Taiwan's Academia Sinica.

“This could be done 10 years from now after a global barcoding data bank is set up,” said Chen, an expert in corals.

Scientists are already working on hand-held barcoders that would enable users to access a barcode data bank using a global positioning system, said Taiwan's Shao Kwang tsao, one of the conference chairs.

Hebert said the alliance would invest heavily in the development of such technology.

This week's conference is being held by the Washington based Consortium for the Barcode of Life, which was set up in 2003 in response to Hebert's initiative and now includes some 160 organisations.

Among them is Taiwan's top academic body, Academia Sinica, one of three chief organisers of the conference.

At its first conference in London in 2005, the consortium's data banks collected some 33,000 DNA references belonging to some 12,700 species.

Today it counts more than 2,90,000 DNA samples from some 31,000 species, including about 20 per cent of the world's estimated 10,000 bird species and 10 per cent of the 35,000 estimated marine and freshwater fish species.

The “barcoding of life” projects have drawn increasing attention, particularly from the US, Canada and Europe, as scientists explore the technique's applications, which range from food safety and consumer protection to the identification of herbal plants.

One British scientist is working on a project to barcode 2,800 species of mosquito or 80 per cent of those known to the world, within two years.

The project is aimed at reducing the scourge of malaria, which infects some 500 million people a year and is spread by some mosquitoes.

Best Hubble Space Telescope Images

NASA : Apply Online to be an Astronaut

NASA is now taking applications from people who want to be astronauts.

The space agency says those with a B.A. in engineering, science or math and three years of relevant professional experience are required.

The application period is open through July 1, 2008.

The interview process is expected to last for six months before NASA announces its 2009 Astronaut Candidate Class.

Click here to apply online.

Additional information about the Astronaut Candidate Program is available by calling the Astronaut Selection Office at 281-483-5907.

Bizarre Object Found Circling Neutron Star

An object recently detected orbiting a neutron star is among the strangest planet-mass bodies ever found, astronomers say.

Instead of circling around a normal star, the low-mass object—likely the "skeleton" of a smaller star—orbits a rapidly spinning pulsar, or neutron star.

The neutron star spins hundreds of times a second—faster than a kitchen blender.

The odd mass, which was spotted on June 7 by NASA's Swift and Rossi X-ray Timing Explorer (RXTE) satellites, orbits the bigger star in a little under once an hour.

The body is located about 230,000 miles (370,149 kilometers) away from the star—slightly less than the distance from Earth to the moon.

Neutron stars usually slow with age, but the gas spiraling from the bizarre object has likely maintained, or even increased, the star's speed.

The star siphons off gas from the orbiting body, as seen in the above artist's illustration. The gas flow occasionally becomes unstable and causes the bright outbursts that can be seen from Earth.

Astronomers suspect the system was once two stars, which formed billions of years ago. Eventually the larger star went supernova, leaving behind the neutron star, while the smaller star expanded into a red giant.

It's unknown whether the smaller star will survive much longer, however.

"It's been taking a beating," Hans Krimm of NASA's Goddard Space Flight Center said in a statement. The neutron star, after all, has been siphoning away its mass for billions of years.

Source : National Geographic

Indian University Course in Rocket Science

India's secretive defence research agency has helped launch a university course in missile sciences and opened its labs to students, hoping to infuse young talent into a stagnating technology program.

India's missile program has built short and long-range missiles, including one that can hit targets deep inside China.

But its projects have been hit by time and cost overruns and the program has also struggled to attract young engineers and scientists in the face of stiff competition from the more lucrative IT sector, experts say.

A first-of-its-kind masters course in applied physics and ballistics, launched this month at Fakir Mohan University in the eastern state of Orissa, hoped to change that, officials said.

"Students have high levels of creativity and we hope their association will help our research activities," said W Selvamurthy, a top Defence Research and Development Organisation (DRDO) official.

"We expect the students from this course to join DRDO after completion of their studies," Selvamurthy, who is DRDO's chief controller of research and development, said by telephone from New Delhi.

Eighteen students selected after a tough screening program for the two-year course would not only study missile engineering and new technologies, but also get to use DRDO labs in the area where the agency has missile testing facilities, officials said.

"We are trying to open our labs to more and more universities," Selvamurthy said.

Formed in 1958 with a network of 10 laboratories, DRDO has 51 labs where 5,000 scientists and 25,000 other employees work, according to the agency's website.

In April, DRDO successfully tested its most ambitious and longest-range ballistic missile, the Agni III, which is capable of carrying a nuclear warhead more than 3,000 km.

Source : Sydney Morning Herald