2010-03-26

New, Ancient Way Of Making Oxygen Discovered

New, Ancient Way Of Making Oxygen DiscoveredDutch bacteria have a previously unknown method to produce oxygen. The process uses methane and nitric oxide, it might predate the development of photosynthesis by hundreds of millions of years, and it could allow life to survive on other planets.

Three natural methods of oxygen production were known before this study. The best known and most common is photosynthesis, in which plants, algae, and some bacteria convert carbon dioxide and water into sugars, which releases oxygen as a waste product. The other two methods are the creation of oxygen from chlorates in bacteria cells and the conversion of reactive oxygen materials using enzymes.

The newly discovered process is used by a microbe found in nearly oxygen-free canals and ditches in the Netherlands, although its particular strain was first discovered in caves in Australia. In the presence of methane gas and nitrites, the microbes broke down the nitrites into nitric oxide, which they then split into nitrogen and oxygen. The oxygen was then used to burn the methane for energy, and the nitrogen was released as a waste product.

The researchers at The Netherlands at the Radboud University in Nijmegen are confident this is what the microbes are doing, but they're less certain how the microbes are doing it. There is some thought an enzyme of some sort is involved, but there are hundred of proteins whose properties are still unknown that could be directing the expression of the enzyme. As such, the exact mechanics of this new oxygen-creating process remain poorly understood, although it's definitely unlike anything seen before.

The researchers are also excited about the potential wider implications of this discovery. Primordial bacteria might have used this method to create oxygen on the early pre-photosynthesis Earth, when the atmosphere was rich in methane and poor in oxygen. This process may also shed new light on the mechanics of methane cycles.

But perhaps most intriguingly, this new process provides a potential method for life to exist on oxygen-low, methane-heavy environments like those of the planets and moons of the outer solar system. In fact, this method would not require there to be any free oxygen in the atmosphere at all - as long as there was sufficient methane and nitrites, that would actually be more than enough for microbes using this process to survive, even thrive.

http://io9.com/5502298/new-ancient-way-of-making-oxygen-discovered



2010-03-03

Dark matter could meet its nemesis on Earth

A SPINNING disc may be all that is needed to overturn Newton's second law of motion - and potentially remove the need for dark matter.

The second law states that a force is proportional to an object's mass and its acceleration. But since the 1980s, some physicists have eyed the law with suspicion, arguing that subtle changes to it at extremely small accelerations could explain the observed motion of stars in galaxies.

The key is to cancel out the acceleration of Earth's rotation, its orbit round the sun, and the orbit of the sun round the galactic centre. The basic idea was first proposed in 2007, when Alex Ignatiev calculated that the accelerations all cancel out for a millisecond at two particular points on Earth's surface, twice a year. That makes the experiment possible in theory, but not feasible.

Now, De Lorenci's team has figured out that a spinning disc can reproduce the effect any time and anywhere on Earth. Their calculations show that if the disc is positioned accurately and its speed precisely controlled, the acceleration at specific points on the disc's rim would cancel out the accelerations produced by the motion of the Earth and the sun.

If the second law is correct at all accelerations, a measuring device mounted on the rim should register no anomalous force at these points. However, if MOND is correct, the device should feel an aberrant kick. "We are able to control the conditions to produce the MOND regime in any place at any time," says De Lorenci.

http://www.newscientist.com/article/mg20527493.900-dark-matter-could-meet-its-nemesis-on-earth.html?DCMP=OTC-rss&nsref=online-news



Transgenic mice could solve the obesity epidemic

By tweaking an enzyme in mice, researchers expected to get rodents with low cholesterol, but fatty livers. Instead they found a switch which might be a weight loss miracle.

The researchers from the University of Alberta bred a mouse lacking a single enzyme that's associated with fat metabolism — triacylglycerol hydrolase (TGH). TGH is partly responsible for releasing triglycerides from the liver where they go on to form very low-density lipoproteins (VLDLs), which are considered "bad" cholesterol. The scientists thought that breeding a mouse deficient in TGH would have fewer VLDLs, and instead found the mice that not only had lower cholesterol, but also system wide metabolic improvement — seemingly without downside.

The researchers hypothesized that removing the TGH would mean the more fat would build up in the liver, as the mechanism by which the fat was released was missing. Instead of getting tiny rodent foie gras, the triglycerides were burned almost immediately rather than being stored, and the liver compensated by synthesizing less fat. The rodents ate more, but also expended more energy, and showed no change in body weight compared to their normal cousins.

The interesting thing? Drugs already exist to block TGH in the human body. While more research needs to be done about the systemic effects of blocking TGH, how specific these drugs are, and if diet alters the way the liver functions in these mice, but it's an important step towards understanding how the body deals with fat and cholesterol. Who knows, we may even get a drug that helps you lose weight without utterly horrible side effects.

http://io9.com/5482969/transgenic-mice-could-solve-the-obesity-epidemic

Old star is 'missing link' in galactic evolution

A newly discovered star outside the Milky Way has yielded important clues about the evolution of our galaxy. Located in the dwarf galaxy Sculptor some 280,000 light-years away, the star has a chemical make-up similar to the Milky Way's oldest stars, supporting theories that our galaxy grew by absorbing dwarf galaxies and other galactic building blocks. Some recent studies had questioned the link between dwarf galaxies and the Milky Way, citing differences between the chemistry of their stars. But the differences may not be so big after all, according to new research published in Nature. "It was a question of finding the right kind of star, and doing that required some new techniques," says Josh Simon , an astronomer at the Observatories of the Carnegie Institution and a member of team that confirmed the star's telltale chemistry. Using earlier techniques, he says, "it was very difficult to recognize exactly which stars were the key ones to study."

"This star is likely almost as old as the universe itself," said astronomer Anna Frebel of the Harvard-Smithsonian Center for Astrophysics, lead author of the Nature paper reporting the finding.

In addition to the star's total metal abundance, researchers also compared the abundance of iron to that of elements such as magnesium, calcium, and titanium. The ratios resembled those of old Milky Way stars, lending more support to the idea that these stars originally formed in dwarf galaxies.

http://esciencenews.com/articles/2010/03/03/old.star.missing.link.galactic.evolution?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+eScienceNews%2Fpopular+%28e%21+Science+News+-+Popular%29&utm_content=Google+Reader