Human remains at Iron Age broch

14 July 2011 Last updated at 14:12 GMT Archaeologists and volunteers have been digging at the ruins of an ancient roundhouse Human remains including parts of a skull and leg bones have been found during an archaeological dig at an Iron Age site in Caithness.

The police and procurator fiscal service have been notified of the finds at Thrumster, near Wick, as normal procedure by archaeologists.

The remains have still to be radiocarbon dated to determine how old they are.

Ancient human remains have previously been uncovered in Caithness.

AOC Archaeology and Yarrows Heritage Trust have been leading teams of 12 to 15 volunteers on the dig.

Dr Andy Heald, of AOC Archaeology, said they had established the site held the ruins of a broch, a massive stone wall Iron Age roundhouse.

He said the bones found could be those of a man.

'Even puppies'

Dr Heald said: "At the moment we have no idea on a date. They could be 50 years old, or 3,000 years old."

If analysis finds that the remains were ancient then they could have been placed as part of a ritual honouring the dead.

Dr Heald said: "When skulls were found in the 19th Century people thought it had to do with cannibalism, or were war trophies.

"Cannibalism is just nonsense."

He added: "At another Caithness site at Whitegate human remains, horses and even puppies were placed at a broch 300 years after it was abandoned.

"It was done in some sort of memory ritual, or for it to be a monument on the landscape."

Caithness has more brochs per square mile than any other part of Scotland, according to Highland Council.

Examples of the ancient buildings are also found on Orkney.

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Human eye 'may act as a compass'

21 June 2011 Last updated at 15:35 GMT By Jason Palmer Science and technology reporter, BBC News The cryptochrome protein comes in more than one type - and the human one can perform as the fly's A light-sensitive protein in the human eye has been shown to act as a "compass" in a magnetic field, when it is present in flies' eyes.

The study in Nature Communications showed that without their natural "magnetoreception" protein, the flies did not respond to a magnetic field - but replacing the protein with the human version restored the ability.

Despite much controversy, no conclusive evidence exists that humans can sense the Earth's magnetic field, and the find may revive interest in the idea.

Although humans, like migratory birds, are known to have cryptochrome in their eyes, the idea of human magnetoreception has remained largely unexplored since pioneering experiments by Robin Baker of the University of Manchester in the 1980s.

Dr Baker used a long series of experiments on thousands of volunteers that suggested humans could indirectly sense magnetic fields, though he never definitively identified the mechanism. In subsequent years, several groups attempted to repeat those experiments, claiming opposing results.

Time, flies

At the heart of the current study is a molecule called cryptochrome - an ancient protein present, in one of its two major forms, in every animal on Earth.

The protein is implicated in the regulation of circadian rhythms - the "body clocks" of humans and other animals - and in the navigational skills of several species including migratory birds, monarch butterflies, and the fruit fly Drosophila melanogaster.

The exact mechanism behind animals' navigational abilities remains a mystery, however, and an active area of research.

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I would be very surprised if we don't have this sense... the issue is to figure out how we use it”

End Quote Steven Reppert University of Massachusetts Medical School Steven Reppert of the University of Massachusetts Medical School and his colleagues have been following the roles that cryptochrome plays in some of these species for a number of years.

D. melanogaster flies can be genetically engineered to produce cryptochrome-2, the version of the protein present in monarch butterflies and in vertebrate animals including humans.

Last year, Dr Reppert's team showed in a Nature paper that flies without either cryptochrome were unable to align themselves with magnetic fields, but that the magnetoreception ability was recovered when the flies produced the non-native cryptochrome-2.

"We developed a system to study the real mechanism of magnetosensing in fruit flies... we can put these proteins from other animals into the fly and ask, 'do these proteins in their different forms actually function as magnetoreceptors?'," Dr Reppert told BBC News.

"Of all the vertebrates, the one that seemed to make the most sense was trying to put in the cryptochrome from humans."

The results mirrored the experiments with monarch butterflies. D. melanogaster flies with no cryptochrome showed no evidence of magnetoreception, but when genetically engineered to produce the human version, they recovered their abilities.

Dr Reppert said that the difficulty in unpicking the nature of human magnetosensing - if it exists - was that, like the circadian rhythms that cryptochromes are also implicated in, we react to it without knowing that we are.

"I would be very surprised if we don't have this sense; it's used in a variety of other animals. I think that the issue is to figure out how we use it."

Dr Baker, who maintains his results proving human magnetoreception were "overwhelming", hopes that the find re-invigorates the pursuit of a final word on the matter.

"I think one of the things that put people off accepting the reality of human magnetoreception 20 years ago was the lack of an obvious receptor," he told BBC News.

"So these new results might actually be enough to tip the balance of credibility. I shall be fascinated to see."

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Human brain's 'bat sight' found

26 May 2011 Last updated at 08:09 GMT Bats use sound to hunt The part of the brain used by people who can "see like a bat" has been identified by researchers in Canada.

Some blind people have learned to echolocate by making clicking noises and listening to the returning echoes.

A study of two such people, published in PLoS ONE, showed a part of the brain usually associated with sight was activated when listening to echoes.

Action for Blind People said further research could improve the way the technique is taught.

Bats and dolphins bounce sound waves off their surroundings and by listening to the echoes can "see" the world around them.

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[They] use echolocation in a way that seems uncannily similar to vision”

End Quote Dr Lore Thaler University of Western Ontario Some blind humans have also trained themselves to do this, allowing them to explore cities, cycle and play sports.

Brain scan

Researchers looked at two patients who use echolocation every day. EB, aged 43, was blinded at age 13 months. LB, 27, had been blind since age 14.

They were recorded echolocating, while microphones were attached to their ears.

The recordings were then played while their brain activity was being recorded in an fMRI machine.

Increased activity in the calcarine cortex was discovered.

Dr Lore Thaler, from University of Western Ontario, said: "This suggests that visual brain areas play an important role for echolocation in blind people."

The study looked at only two people so cannot say for certain what happens in the brains of all people who learn the technique, but the study concludes: "EB and LB use echolocation in a way that seems uncannily similar to vision."

Susie Roberts, rehabilitation officer at Action for Blind People, said: "This research into brain activity and echolocation is very interesting and improves our understanding of how some visually impaired people may be processing information to help them navigate safely.

"Further investigation may help to improve the way the technique is taught to people in the future, potentially improving their mobility and independence."

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