Science news digest – 7th January 2013
In the science news this week, the UK’s first hand transplant takes place, a new system that could rival GPS, ‘Black Beauty’ rock is a new type of Martian meteorite, and finally… Roald Dahl didn’t get his maths right.
UK’s first hand transplant
A former pub landlord, Mark Cahill, has become the first person in the UK to have a hand transplant. The eight hour operation took place at Leeds General Infirmary on December 27, 2012 when a donor hand became available.
Cahill lost the use of his right hand after it became affected by gout, a type of inflammatory arthritis, about five years ago.
Following the transplant, Cahill has already gained some movement in his fingers, but it is still very early days to determine how successful the operation will have been in the long term.
At the moment, he still has no sense of touch, but he told the BBC that: "When I look at it and move it, it just feels like my hand.
"Right now it feels really good, it's not a lot of pain, it looks good, it looks a great match and I'm looking forward to getting it working now."
As well as being the first hand transplant in the UK, it was also the first time a recipient has had their hand amputated during an operation in order to attach a donor hand.
The hand was attached just above the wrist. The two bones of the forearm were connected to the donor’s with metal plates, and the surgeons also connected the nerves, blood vessels and tendons with great precision.
The transplant has been in the planning stages for the past two years, whilst the surgical team looked for an appropriate candidate.
The potential patients had to be assessed both physically and psychologically to determine whether they would be suitable for the operation. The first recipient, Clint Hallam from New Zealand, had his new hand removed after complaining that it was like a dead man’s hand with no feeling in it.
He felt mentally detached from the transplant, which was wider and longer than his own arm, and the skin was a different colour.
Surgeons do try to find a close physical match for the patients, but the transplant will always be visible. The mental challenge for the patient is considered just as important as the surgical element.
Professor Norman Williams, the president of the Royal College of Surgeons, said: "This is yet another example of life-changing surgical advancements that are now possible."
"As with all procedures that improve the quality of life rather than save it, there is an ethical balance to be struck - especially as the lifelong anti-rejection medication that the patient would need to take carries its own risks.
"Care always needs to be taken in choosing suitable patients who understand the risks and benefits."
Ground-based positioning technology could rival GPS
A new positioning system, called Locata, which uses ground-based equipment instead of satellites, could compete with GPS, reported New Scientist.
By projecting radio waves over a localised area, the technology produces a signal that is a million times stronger on arrival than GPS. The system also works indoors, and the firm claim that the receivers will fit inside a regular smartphone.
Even the US military, which invented GPS technology in the first place, have signed a contract to allow for a large scale test of Locata at a missile range in New Mexico.
"This is one of the most important technology developments for the future of the positioning industry," says Nunzio Gambale, CEO and co-founder of the firm Locata, based in Griffith, Australia.
Indoor positioning is the holy grail of location-tracking technology, and current systems from companies such as Google and Nokia, have a limited range and tend to have an accuracy in the order of a few metres.
Locata, on the other hand, was shown to be accurate to within 18 centimetres along any axis, at a test by the US Air Force, although admittedly the tests were performed in an open desert, where GPS also works incredibly well.
The problem with GPS signals are that they are weak and can easily be blocked by solid objects.
Although, Locata’s signals are much stronger than those from GPS, this is no guarantee that the system will perform better in an urban environment. Often the issue for location-tracking software is due to the number of blockages and reflections, which can confuse receivers, rather than down to strength.
Martian meteorite is first of its kind
Scientists have claimed that a meteorite found in the Moroccan desert in 2011 is in fact a new type of Martian meteorite, which has not been studied before.
The dark rock weighs 320g and has been given the nickname “Black Beauty” because of its appearance, reported the BBC.
Its texture and chemistry make it stand out from other objects that have arrived here from Mars, and at just over two billion years old, it is also much older than other Martian meteorites.
“It has some resemblance to the other Martian meteorites but it's also distinctly different in other respects," said Carl Agee from the University of New Mexico and who led the study. "Both in the way it just looks in hand sample, but also in its elemental composition."
There are just over 100 Martian meteorites currently in collections worldwide, all of which have been blasted off the surface of Mars by some asteroid or cometary impact. The rocks then spent millions of years travelling through space before eventually hitting the surface of the Earth.
Virtually all the Martian meteorites can be put into three distinct classifications known as Shergotty, Nakhla, and Chassigny after key specimens. These are often referred to as the SNC meteorites.
Prof Agee and his colleagues, argue that the “Black Beauty” meteorite should be put in its own class separate from the SNC meteorites.
Geochemically, the meteorite is made up of a lot of alkali elements, such as potassium and sodium, a trait not seen in the SNC meteorites, but is precisely what the robot rovers have found on the surface of Mars.
There is also much more water in the rock – about 6,000 parts per million –which is about ten times more water than that is found in the most water-rich SNC rocks.
"This rock is from two billion years ago and a lot of the SNCs are from only about 200-400 million years ago," explained Prof Agee.
"And of course those most recent times on Mars have witnessed a cold, dry planet with a thin atmosphere. A lot of people believe that early Mars, on the other hand, was a lot warmer and a lot wetter, and maybe even a harbour for life.
"So, what happened in between? When did this transformation to drier conditions occur? Well, NWA 7034, because of its greater age, may be able to address those questions."
Roald Dahl got his maths all wrong
A group of physics students from Leicester University have made the startling discovery that Roald Dahl made a mistake in his calculation of how many seagulls it would take to lift the giant peach from his famous novel, James and the Giant Peach.
Instead of the 501 seagulls the author claimed would be needed, the students argue that given the size and density of the peach, and the weight that each seagull could manage to lift, in fact 2,425,907 seagulls would be needed to manage such a feat.
"Through examining the buoyancy and modelling the seagulls as aerofoils it has been found that although the initial part of the journey is possible, given a sufficiently hollow peach James would have to tether approximately 2.5m common gulls, rather than the 501 as described in the book," they write in their paper.