Scientists from Harvard and MIT have discovered that human brains tend to perceive a face as either male or female depending on where it appears in our field of view, according to a recently published study.

On a computer, the team generated a number of faces ranging from extremely female, to androgynous, to extremely male. They then flashed these faces at various locations on a computer screen and recorded which gender the subjects observed.

The researchers discovered that more androgynous-looking faces, when shown in certain parts of the visual field, would sometimes look male and sometimes look female.

But the researchers also found that the regions that recognize a given face as male or female differ from person to person. That is, a face that looks male in a certain portion of the visual field might not appear male to another person when displayed in the same visual field.

"You expect the same face to look the same everywhere," said Arash Afraz, a post-doctoral fellow at MIT and the lead author of the study. "When you examine it carefully you notice a huge difference."

A long-lost treasure of Canadian history - a one-of-a-kind, 17th century map of the country, hand-drawn by the leading English cartographer of the era - has been discovered under a thick layer of dust in the utility room of an old house in rural Scotland.

The previously unknown depiction of New France and "Nova Britania" covers an area stretching from modern-day Manitoba on the western shore of Hudson Bay to "Labradore," "New Scotland" (Nova Scotia) and the island of "New Found Land" in the east.

The southern part of Baffin Island appears at the upper edge of the map, with the fledgling American colonies of New England shown to the south.

Described by the British auction house that found the map as "remarkably well preserved," the 311-year-old relic is made of vellum, a specially prepared sheet of animal skin - typically from sheep - that was used by European map-makers in the 1600s to produce durable illustrations of the new lands being discovered across the Atlantic Ocean.

Such originals were usually used to create the etchings for published maps or atlases, but the one found in Scotland appears to have been specially commissioned for a commercial client and never copied in print.

The map is dated 1699 and signed by John Thornton, a renowned figure in 17th century cartography known to have been hired to produced maps and marine charts for the Hudson's Bay Company and East India Company, the trading firms that served as the commercial spearhead of British imperialism during the golden age of European exploration.

A recent excavation programme at a standing stone known as Trefael, near Newport (south-west Wales) has revealed that what originally was a portal dolmen in later times was transformed in a standing stone, probably used as a ritual marker to guide communities through a sacred landscape.

This solitary stone has over 75 cupmarks gouged onto its upper surface. Following the complete exposure of the capstone through excavation, it is now considered by several astronomers that the distribution of the cupmarks may represent a section of the night sky that includes the star constellations of Cassiopeia, Orion, Sirius and of course the North Star.

Thanks to biotechnology and widespread genetic modification, the meal you'll enjoy tomorrow certainly isn't your grandma's feast.

Since they were introduced 15 years ago, genetically modified foods have taken astonishing hold in North America. This time of year, the result is a Thanksgiving menu that may, on the surface, look much the same as the one your grandma cooked 20 years ago. But at the genetic level, it is very different, and it's a far cry from the fabled feast shared by the pilgrims and American Indians in the 17th century. In celebration of Thanksgiving, the most food-focused day of the year, here's a look at how biotechnology is changing the way we eat.

Scientists claim to be a step closer to reversing the ageing process after rejuvenating worn out organs in elderly mice. The experimental treatment developed by researchers at Harvard Medical School turned weak and feeble old mice into healthy animals by regenerating their aged bodies.

The surprise recovery of the animals has raised hopes among scientists that it may be possible to achieve a similar feat in humans - or at least to slow down the ageing process.

An anti-ageing therapy could have a dramatic impact on public health by reducing the burden of age-related health problems, such as dementia, stroke and heart disease, and prolonging the quality of life for an increasingly aged population.

"What we saw in these animals was not a slowing down or stabilisation of the ageing process. We saw a dramatic reversal - and that was unexpected," said Ronald DePinho, who led the study, which was published in the journal Nature.

"This could lead to strategies that enhance the regenerative potential of organs as individuals age and so increase their quality of life. Whether it serves to increase longevity is a question we are not yet in a position to answer."

An oxygen atmosphere has been found on Saturn's second largest moon, Rhea, astronomers announced Thursday - but don't hold your breath for colonization opportunities.

For one thing, the 932-mile-wide (1,500-kilometer-wide), ice-covered moon is more than 932 million miles (1.5 billion kilometers) from Earth. For another, the average surface temperature is -292 degrees Fahrenheit (-180 degrees Celsius).

And at less than 62 miles (100 kilometers) thick, the newfound oxygen layer is so thin that, at Earthlike temperatures and pressure, Rhea's entire atmosphere would fit in a single midsize building.

During the Vietnam War, the U.S. Air Force laced the skies over North Vietnam and parts of Laos with small quantitites of aerosols designed to amplify the intensity of rainfall patterns by enhancing the density of clouds. The operation, known as "Operation Popeye," involved flying more than 2,602 U.S. cloud-seeding missions from Udorn Royal Thai Air Force Base over the course of several years. The effort apparently succeeded in flooding major Viet Cong supply routes and denying the use of trails and roads by extending the monsoon season over North Vietnam.

When reports of Operation Popeye surfaced in the media, Congress held hearings, the United Nations created a convention banning future military use of weather modification technologies and the nascent field of weather modification appeared to go the way of the passenger train - until recently.

The explorer, Christopher Columbus, was the son of a Polish king living in exile in Madeira and hid his royal roots to protect his father, a new book claims.

A Portuguese historian believes he has solved the 500 year-old mystery of the adventurer's true identity after a thorough investigation of medieval documents and chronicles.

The origins of the man who discovered the Americas has long been a subject of speculation.

Contemporary accounts named his birth place as the Italian port of Genoa to a family of wool weavers but over the centuries it has been claimed that he was a native of Greece, Spain, France, Portugal and even Scotland.

Others claimed his origins were hidden because he was Jewish or secretly working as a double agent for the Portuguese royal family.

But the latest theory suggests that the great navigator, who died in 1506 after four voyages to the New World, was in fact of royal blood: the son of King Vladislav III who was supposedly slain in the Battle of Varna in 1444.

They are at the very edge of current U.S. technological capabilities; one is a supposedly mothballed technology test-bed, the other a super-secret space plane that is currently on orbit - but set to land soon. They are the X-planes, experimental spacecraft that are proving out concepts and capabilities whose beginnings can be traced to the dawn of the space age.

It would appear from amateur observers on the ground that the secretive U.S. Air Force X-37B space plane - will be landing soon. This prediction is based off the fact that the craft is dropping in altitude and the more basic fact that it is nearing the limit of its orbital capabilities and has to return to terra firma. According to the U.S. Air Force, the X-37B can remain on orbit for around nine months or 270 days at maximum, this means that the craft should be landing sometime in the middle of January.

The X-37B or Orbital Test Vehicle (OTV) lifted off from Cape Canaveral Air Force Station in Florida on Apr. 22, atop an Atlas V rocket. Not much is known after launch due to a media blackout imposed by the U.S. Air Force.

Pity poor Leif Ericsson. The Viking explorer may well have been the first European to reach the Americas, but it is a certain Genoan sailor who gets all the glory. Thanks to evidence that has until now consisted only of bare archeological remains and a bunch of Icelandic legends, Ericsson has long been treated as a footnote in American history: no holiday, no state capitals named after him, no little ditty to remind you of the date of his voyage. But a group of Icelandic and Spanish scientists studying one mysterious genetic sequence - and one woman who's been dead 1,000 years - may soon change that.

Ten years ago, Agnar Helgason, a scientist at Iceland's deCODE Genetics, began investigating the origin of the Icelandic population. Most of the people he tested carried genetic links to either Scandinavians or people from the British Isles. But a small group of Icelanders - roughly 350 in total - carried a lineage known as C1, usually seen only in Asians and Native Americans. "We figured it was a recent arrival from Asia," says Helgason. "But we discovered a much deeper story than we expected."

Helgason's graduate student, Sigridur Sunna Ebenesersdottir, found that she could trace the matrilineal sequence to a date far earlier than when the first Asians began arriving in Iceland. In fact, she found that all the people who carry the C1 lineage are descendants of one of four women alive around the year 1700. In all likelihood, those four descended from a single woman. And because archeological remains in what is Canada today suggest that the Vikings were in the Americas around the year 1000 before retreating into a period of global isolation, the best explanation for that errant lineage lies with an American Indian woman: one who was taken back to Iceland some 500 years before Columbus set sail for the New World in 1492.