Stars in 'globular clusters' are born in several bursts, rather than all at once. (Google Photo)

In a complex Universe, astronomers thought they had at least one simple system to tell them how stars are born. Turns out they were wrong, Nature.com reported.
Results from Hubble confirm what some had feared for years: stars in ’globular clusters’ are born in several bursts, rather than all at once. This means that globular clusters--small, dense groups of stars found orbiting galaxies--aren’t as simple as astronomers used to think.
“It’s changing our ideas completely,“ says Giampaolo Piotto of the University of Padua in Italy. “We have to change our textbooks.“
The nature of these stellar nurseries means that previous models of these apparently simple systems are now wrong. And that means trouble for modeling more complex creatures, such as galaxies. “If you have problems reproducing star formation in globular clusters, you will have problems with a galaxy,“ says Piotto.

Color Conundrum
Astronomers had long assumed that globular clusters were the simplest stellar systems in existence. They thought that the hundreds of thousands of stars in each cluster were born in one go, condensing from a dust cloud early in the Universe’s history, billions of years in the past. These dense balls of stars are now found in orbit around galaxies such as the Milky Way.
Astronomers noticed as much as 30 years ago that helium-burning stars within a globular cluster come in a range of colors. Color is usually linked to a property such as age or the chemical make-up of a star. But astronomers still thought that globular clusters ought to be uniform in age and composition, so they assumed something else--some unknown parameter--had to be responsible.
This became known as the ’second parameter problem’, but it proved impossible to resolve.
Then, in 2004, researchers reported that hydrogen-burning stars in a globular cluster known as Omega Centauri (NGC 5139) seemed to fall into two distinct classes1. One set of stars was somewhat bluer than the other.
This was stronger evidence that something funny was going on. But it wasn’t entirely convincing, because Omega Centauri is odd in other ways, too.
Alison Sills of McMaster University in Hamilton, Canada, says her reaction was to “file it under ’Omega Cen equals weird’ and be done“.

Normal Surprise
“Now we can’t do that,“ she says. On 23 August, in Prague, Piotto presented data to the General Assembly of the International Astronomical Union, showing that a normal globular cluster also has two sets of stars.
An analysis of Hubble Space Telescope images taken on 9 August of object NGC 2808, a globular cluster considered utterly normal, shows that its hydrogen-burning stars fall into two groups. “You see two sequences, there’s no doubt about that,“ says Piotto.
“It is a beautiful achievement,“ says Francesca D’Antona of the Astronomical Observatory of Rome in Monteporzio, Italy.

The figure shows the atomic configuration of titanium-decorated cis-polyacetylene with five hydrogen molecules attached to each titanium atom. (Physicweb Photo)

A series of computer simulations has identified a polymer material with a very large capacity for storing hydrogen that could be exploited in fuel cells. Jisoon Ihm and colleagues at Seoul National University in South Korea have discovered that polyacetylene with titanium atoms attached to the polymer chain can hold 63 kilograms of hydrogen per cubic meter--more than any other similar material in their survey, Physicweb wrote.
A low-cost, high-capacity hydrogen-storage medium is essential for the commercialization of hydrogen fuel-cell technologies. Researchers had previously looked at carbon nanotubes, hydrogen-clathrate-hydrates and other nanostructured materials as ways of storing hydrogen, but they only work in fuel cells at low temperatures or high pressures. Now, Ihm and co-workers have shown that polymers covered with metal atoms can store a significant amount of hydrogen under more practical working conditions.
The large storage capacity is predicted because numerous hydrogen molecules are attracted to the metal atoms that lie along the polymer chain. Using a series of first-principles electronic-structure calculations, the physicists worked out how much energy the hydrogen molecules need to bind to the metal atoms. They looked at a wide combination of metal atoms (including titanium, scandium and vanadium), polymers (including polyacetylene, polypyrrole and polyaniline) and bonding sites for the hydrogen on the metal atoms.
The researchers found that a form of polyacetylene “decorated“ with titanium atoms was the best. This molecule consists of a series of carbon atoms linked together in a chain by alternating single and double bonds. Each carbon atom has one hydrogen atom that can be replaced by a particular atom like titanium.
They found that up to five hydrogen molecules can be attached to each titanium atom in this particular form of polyacetylene, allowing the material to reversibly store 7.6 wt% of hydrogen, or 63 kilograms per cubic meter under practical working conditions. This value is higher than a target of 45 kilograms per cubic meter that the US Department of Energy said should be reached by 2010.
“Our results will have considerable importance for experimentalists and engineers to synthesize metal-decorated polymers for hydrogen storage,“ Ihm told PhysicsWeb. “Indeed, we have already begun to make some titanium-decorated polymers in collaboration with other researchers and are measuring their hydrogen-storage capacity now“.

Researchers studying avian influenza say they have agreed to share data that were previously being kept behind closed doors--a move they hope will speed insights into the virus that threatens to spark a human pandemic, NaturalScience said.
Some countries and organizations have come under fire for hoarding genetic information about the virus. The data have been kept under wraps partly because of concerns that other groups might use them and publish scientific findings without giving due credit to researchers involved.
Now many leading avian influenza scientists have tentatively agreed to share data as part of an effort called the Global Initiative on Sharing Avian Influenza Data (GISAID).
The precise details of the agreement are still being thrashed out. But, in essence, the participants have agreed to place genetic sequences into secure sections (which have not yet been set up) of existing online databases, as soon as possible after producing and analyzing them. The group proposes using the International Nucleotide Sequence Database Collaboration, a network of three major public databases, for the collection.
The data will, at first, only be accessible to scientists who have signed up to the agreement, but will become open to the public after 6 months at the most.
Scientists who sign up make a promise to share their sequences. They must also agree to collaborate with, and appropriately credit, all other researchers in publications and intellectual-property agreements.
By storing all the sequences in a designated place and allowing more open access, the hope is that researchers will be able to carry out comparisons quickly of one new strain against many others from both animals and humans. This type of analysis can reveal whether a virus is acquiring mutations as it spreads between bird flocks, or--should the virus start spreading between people--whether it is becoming resistant to drugs.
Until now, research organizations have tended to keep their own repositories of avian influenza sequences. Access to many sequences was restricted to a global network of 15 flu laboratories associated with the World Health Organisation (WHO).
Veterinary virologist Ilaria Capua at the Vialle dell’Universita in Padova, Italy, started something of a backlash against this system in March this year. Instead of placing her flu sequence data in the WHO-linked, password-protected database, she chose to enter it into the publicly available GenBank, and called on colleagues to do the same. “When you’re facing a pandemic, you have to get your priorities straight,“ she says.

High-tech laboratory tools, like computers, are often updated publicly as their analytical capabilities expand. NIH grantees report they have developed a second generation “lab on a silicon chip“ called the MitoChip v2.0 that for the first time rapidly and reliably sequences all mitochondrial DNA. Mitochondria, the energy-producing organelles that power our cells, are unique because they are equipped with their own genetic instructions distinct from the DNA stored in the cell nucleus.
NewKerala quoted the authors as saying that their full-sequence chip will be a key tool in accelerating research on mitochondrial DNA, a growing area of scientific interest. This interest stems from data that suggests natural sequence variations and/or mutations in each person’s mitochondrial DNA could be biologically informative in fields as diverse as cancer diagnostics, gerontology, and criminal forensics.
According to Dr. Joseph Califano, a scientist at Johns Hopkins University School of Medicine in Baltimore and senior author on the paper, the MitoChip v2.0 showed in his group’s hands better sensitivity that its predecessor to sequence variations in head and neck cancer samples. The v2.0 also detected nearly three dozen variations in the non-coding D-loop, long considered to be a sequencing no-man’s land and which the original MitoChip did not include.
“At this point, we don’t foresee a MitoChip v3.0,“ said Califano, whose research was supported by the NIH’s National Institute of Dental and Craniofacial Research. “The v2.0 is a very good tool in that we’ve also arrayed 500 of the most common haplotypes--or grouped patterns of known DNA variations--banked in the mitochondrial public database.“
Mitochondria are oblong, thread-like structures dispersed throughout the cell’s cytoplasm. Hundreds to thousands of mitochondria exist in each human cell, occupying up to a quarter of their cytoplasm. Sometimes informally described as “cellular power plants,“ mitochondria convert organic materials into ATP, the cell’s energy currency and without which life would cease.
As early as the 1920s, scientists uncovered clues that mitochondria might play a role in causing cancer. But like the other DNA in the cell nucleus, scientists lacked the needed research tools throughout most of the 20th century to systematically study the chemical composition of the mitochondrial genome, or complete set of genes, and its association to human disease.
In the early 1980s, scientists in England performed the then-Herculean feat of sequencing the complete human mitochondrial genome. The genome consisted of 16,568 base pair, or units, of DNA and encoded 37 contiguous genes. But because of the balky sequencing tools of the day and their high cost, much of the subsequent research progressed slowly or stalled.
By 1996, new technology brought new opportunity. Scientists with the company Affymetrix in Santa Clara, Calif. developed the first mitochondrial sequencing microarray. Roughly the size of a quarter, the silicon chip had lithographically annealed to it up to 135,000 short, arrayed bits of DNA sequence that, collectively, spanned most of a single strand of mitochondrial DNA.

Your intentions may be good, but exercising outdoors in a city may be riskier than you think, one expert says.
Outdoor activity can cause serious damage to a person’s health because of elevated air pollution levels. Those especially at risk are those who exercise by running, bicycling or skating, HealthDay reported.
According to Dr. Joseph T. Cooke, associate professor of clinical medicine and patient safety officer at New York-Presbyterian Hospital/Weill Cornell Medical Center, the danger lies in the components of air pollution. The three main culprits are fine particulate matter, (the mixture of solid particles and liquid droplets in the air), ozone (a gas composed of three oxygen atoms) and carbon monoxide.
These components of air pollution irritate the lungs, making it harder to breathe and worsening problems initially caused by asthma, bronchitis, cardiopulmonary maladies, and emphysema.
“The pollutants affect the lungs by causing inflammation or irritation of the airway lining,“ Cooke explained in a prepared statement. “More mucus and phlegm is produced, and small muscles surrounding the airway respond by squeezing down. The work of breathing increases, and it becomes more difficult to get oxygen into the body,“ he said.
The three pollutants are located in cities around the world. Fine particulates are emitted from the diesel engines of buses and trucks. Carbon monoxide arises from cigarette smoke and automobile exhaust, and it has the ability to force oxygen out of a person’s circulatory system.
For those exercising, overexposure to carbon monoxide can lead to dizziness, confusion, headaches and dangerously high body temperatures. Ozone, which is the largest component of smog in cities, adversely affects breathing patterns and decreases the size of airways, making the lungs more resistant to oxygen.