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Sunday, March 30, 2014

Scientists create ‘designer’ chromosome



PARIS : Scientists have created the first man-made chromosome for a complex-celled organism - a feat hailed Friday as a big step towards acquiring the controversial ability to redesign plants or animals.

A synthetic chromosome was inserted into a brewer’s yeast cell, which functioned as normal - the key test of success, the international team reported in the journal Science. “Our research moves the needle in synthetic biology from theory to reality,” said Jef Boeke, director of the New York University’s Institute for Systems Genetics, who was a member of the research team. Yeast is a closely-studied representative of the group of eukaryotes, organisms with complex cells that contain a nucleus and other structures enclosed within membranes. All plants and animals, including humans, have eukaryotic cells.

Chromosomes have previously been synthesised for bacteria, which are simpler, prokaryotic organisms. Yeast is used to make beer, biofuel and medicines, and researchers believe it can be made to work more efficiently with genetic modifications.

Boeke and his team unravelled the coding of one of yeast’s 16 chromosomes, then used software to make changes to it - removing repetitive and less-used regions.

They then built a synthetic version of this altered chromosome from scratch, stringing together individual nucleotides - the chemical building blocks of the genes that make up chromosomes, which in turn comprise the genome.

Sunday, March 23, 2014

Fierce 2012 magnetic storm barely missed Earth

Earth dodged a huge magnetic bullet from the sun on July 23, 2012. According to University of California, Berkeley, and Chinese researchers, a rapid succession of coronal mass ejections - the most intense eruptions on the sun - sent a pulse of magnetized plasma barreling into space and through Earth's orbit.

Had the eruption come nine days earlier, it would have hit Earth, potentially wreaking havoc with the electrical grid, disabling satellites and GPS, and disrupting our increasingly electronic lives.

The solar bursts would have enveloped Earth in magnetic fireworks matching the largest magnetic storm ever reported on Earth, the so-called Carrington event of 1859. The dominant mode of communication at that time, the telegraph system, was knocked out across the United States, literally shocking telegraph operators. Meanwhile, the Northern Lights lit up the night sky as far south as Hawaii.

In a paper appearing today (Tuesday, March 18) in the journal Nature Communications, former UC Berkeley postdoctoral fellow and research physicist Ying D. Liu, now a professor at China's State Key Laboratory of Space Weather, UC Berkeley research physicist Janet G. Luhmann and their colleagues report their analysis of the magnetic storm, which was detected by NASA's STEREO A spacecraft.

"Had it hit Earth, it probably would have been like the big one in 1859, but the effect today, with our modern technologies, would have been tremendous," said Luhmann, who is part of the STEREO (Solar Terrestrial Observatory) team and based at UC Berkeley's Space Sciences Laboratory.

A study last year estimated that the cost of a solar storm like the Carrington Event could reach $2.6 trillion worldwide. A considerably smaller event on March 13, 1989, led to the collapse of Canada's Hydro-Quebec power grid and a resulting loss of electricity to six million people for up to nine hours.

Wednesday, March 19, 2014

Superhero Vision Coming in Graphene Contact Lenses?

It sounds like something from a spy thriller movie: putting on contact lenses that give you infrared vision without the need for a bulky contraption that covers your face. But now, thanks to research at the University of Michigan, such a contact lens is a real possibility.

The Michigan researchers turned to the optical capabilities of graphene to create their infrared contact lens. IBM last year demonstrated some of the photoconductivity mechanisms of graphene that make it an attractive infrared detector.

Graphene is capable of detecting the entire infrared spectrum, with visible and ultraviolet light thrown in. But where graphene giveth, it also taketh away. Because graphene is only one atom thick, it can absorb only 2.3 percent of the light that hits it. This is not enough to generate an electrical signal and without a signal, it can’t operate as a infrared sensor.

"The challenge for the current generation of graphene-based detectors is that their sensitivity is typically very poor," said Zhaohui Zhong, assistant professor at the University of Michigan, in a press release. "It's a hundred to a thousand times lower than what a commercial device would require."

In research that was published in the journal Nature Nanotechnology ("url=http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2014.31.html] Graphene photodetectors with ultra-broadband and high responsivity at room temperature"), the Michigan researchers devised a new method for generating the electrical signal. Instead of trying to measure the electrons that are released when the light strikes the material, they amplified an electrical current that is near the electrical signals generated by the incoming light.

Saturday, March 8, 2014

Nasa Plots Daring Robotic Mission to Jupiter's Watery Moon

Nasa is plotting a daring robotic mission to Jupiter's watery moon Europa, a place where astronomers speculate there might be some form of life.

The space agency set aside $15 million in its 2015 budget proposal to start planning some kind of mission to Europa. No details have been decided yet, but Nasa chief financial officer Elizabeth Robinson said on Tuesday that it would be launched in the mid-2020s.

Robinson said the high radiation environment around Jupiter and distance from Earth would be a challenge. When Nasa sent Galileo to Jupiter in 1989, it took the spacecraft six years to get to the fifth planet from the sun.

Rensselaer Polytechnic Institute astronomer Laurie Leshin said it could be "a daring mission to an extremely compelling object in our solar system."

Past Nasa probes have flown by Europa, especially Galileo, but none have concentrated on the moon, one of dozens orbiting Jupiter. Astronomers have long lobbied for a mission to Europa, but proposals would have cost billions of dollars.