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SCIENCE UPDATE
Genetic material may help make nano-devices
The genetic building blocks that form the basis for life may also be used to build the tiny machines of nanotechnology, US researchers have said. A team at Purdue University said they had used ribonucleic acid, or RNA, to build microscopic structures such as spirals, triangles, rods and hairpins, that could serve as components of nanotechnology devices.
Nanotechnology is the science of making devices on the scale of nanometers — billionths of a meter. Such “nanoscale” devices might be used in medicine, or as computers woven into everyday materials such as clothing.
“Biology builds beautiful nanoscale structures, and we’d like to borrow some of them for nanotechnology,” Peixuan Guo, a professor of molecular virology at Purdue, said in a statement.
The work of Guo and colleagues at Purdue’s School of Veterinary Medicine was reported in the August issue of the journal Nano Letters.
In their experiment, Guo and his colleagues tried to exploit RNA’s ability to assemble itself into shapes. So far researchers have faced problems trying to manipulate the miniature components needed for nanotechnology, Guo said. “We are short of tiny steam shovels to push them (the components) around. So we need to design and construct materials that can assemble themselves.”
Dieter Moll, a researcher in Guo’s lab, said the components made with RNA could be useful to industrial and medical specialists, who would appreciate “their ease of engineering and handling.”
Cassini finds new Saturn moons
The Cassini-Huygens mission in orbit around Saturn has discovered two new moons around the ringed planet. The new discoveries take Saturn’s total tally of natural satellites to 33.
The moons are about 3km and 4km across and located 194,000km and 211,000km from Saturn’s centre. They are provisionally named S/2004 S1 and S/2004 S2 though one of the new moons may have been spotted before in a single image from the Voyager probe. Officials said they may be the smallest bodies yet seen orbiting the gas giant.
The new satellites are between the orbits of two other Saturnian moons, Mimas and Enceladus.
S/2004 S1 and S/2004 S2 were first seen by Dr Sebastien Charnoz, a colleague of Cassini imaging team member Andre Brahic at the University of Paris, France.
“Discovering these faint satellites was an exciting experience, especially the feeling of being the first person to see a new body of our Solar System,” said Dr Charnoz.
Scientists expected moons as small as S/2004 S1 and S/2004 S2 might be found within gaps in Saturn’s rings and perhaps near the F ring. But they were surprised these small bodies are between two major moons.
The smallest previously known moons around Saturn are about 20km across.
Small comets speeding around the outer Solar System would be expected to collide with small moons and pulverise them. The fact that these moons exist where they do might place limits on the number of small comets in the outer Solar System. This is vital for understanding the zone beyond Neptune known as the Kuiper Belt, which is filled with small, icy bodies and is thought to be a source for comets.
It also sheds light on the cratering histories of the moons around giant planets such as Saturn. Cratering is used by some scientists as an indicator of the age of planetary surfaces.
S/2004 S1 could be an object spotted in a single image taken by Nasa’s Voyager spacecraft 23 years ago, which was at the time given the name S/1981 S14.
Nasa identifies foam flaw
The foam that struck the space shuttle Columbia after liftoff and led to the deaths of all seven astronauts on board was defective, Nasa revealed.
An official investigation into the accident, conducted by the Columbia Accident Investigation Board, had left the matter open, since none of the foam or the fuel tank could be recovered for study.
But the space agency said that testing had since confirmed the defect and found the foam broke off the shuttle’s external fuel tank because Nasa did not know its procedures for applying foam insulation were flawed.
A suitcase-sized chunk of foam from an area of the tank known as the left bipod, one of three areas where struts secure the orbiter to the fuel tank during liftoff, broke off 61 seconds into the flight on Jan. 16 of last year. It gouged a large hole in Columbia’s left wing.
The damage went undetected during the shuttle’s 16-day mission, but caused the nation’s oldest spacecraft to break apart under the stress of re-entering the Earth’s atmosphere on Feb. 1, killing the astronauts.
Cloning go-ahead for scientists
British scientists have been given permission to perform therapeutic cloning using human embryos for the first time. The Human Fertilisation and Embryology Authority granted the licence to experts at the University of Newcastle.
They are investigating new treatments for conditions including diabetes, Parkinson’s and Alzheimer’s disease.
The controversial decision could open a new era of research by scientists looking for remedies for diseases.
The research will take place at the International Centre for Life in Newcastle, involving experts from the Institute of Human Genetics at Newcastle University, and the Newcastle Fertility Centre. — Sci-tech World Report
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