They used the ABCD criterion for what an atypical mole is," Stefanovska said. "That's Asymmetry; uneven Border; several different Colors; and a Diameter larger than six millimeters and evolving."
Margherita Pesce, a biologist in the Pisa University group, shone red laser light on the chosen moles for about 30 minutes, focusing the light on capillaries beneath the moles. Ordinarily, the flow of red blood cells fluctuates in a way that is regulated by details in the properties of the blood vessels. In melanoma, Stefanovska explained, this regulation appears to be absent; that leads to a considerably less variable blood flow signal that the laser Doppler process detected.
Gemma Lancaster, a member of Stefanovska's team, analyzed the signals, adapting an analytical technique originally used to study earthquakes. "We found that we could generate biomarkers for melanoma," Stefanovska said.
Rossi's team, meanwhile, biopsied the moles, and examined them for evidence of melanoma.
Comparison of the results revealed that the laser Doppler method identified all ten cases of melanoma revealed by biopsy and 40 of the 44 benign moles.
Stefanovska emphasized that several steps remain before the technique can be considered for routine dermatological practice.
"We will need a large clinical study if we want to make it a proper clinical tool," she said. That's because regulatory authorities require proof that new medial procedures work for large numbers of patients before approving them. "We will start applying for bigger grants" to support the research, she added. The grants will support a larger clinical study, and will enable improvements in the laser Doppler technology,
Those improvements include reducing the time of exposure to the laser. "We will be able to do it in ten minutes and still have all the reliable biomarkers," Stefanovska forecasted. Like sailors putting a finger to the wind, migrating moths check the atmospheric conditions around them and adjust their headings accordingly, a new study finds. They do it by sensing turbulence, which helps them determine whether the wind is blowing them off course.
Scientists already know moths, birds, bats and other airborne nocturnal animals navigate using landmarks and their own internal compasses. They also must account for wind and atmospheric conditions, which can buffet them around. But researchers haven't determined how animals do this — do they look at the ground to double-check their routes, or somehow check the wind itself? A quirk of atmospheric physics pointed to the answer.
"Imagine you're in a hot air balloon, drifting with the wind at night, and you closed your eyes. And someone said to you, 'Which way is the wind blowing?' You would have no idea," said Jason Chapman, a biologist who studies animal movement at Rothamsted Research in England and who co-authored the new study. "You're moving in the fluid, the air, and you're in a sensory vacuum."
But the rules of fluid dynamics can provide a clue. The ride gets smoother, or less turbulent, when you head downwind. That means you could use any change in turbulence to determine which way the wind is blowing — and which way it's carrying you, Chapman said. Then you could make course corrections using a compass or another navigation system.
Using radar, Chapman and his colleagues determined a common European moth called silver Y moths (Autographa gamma) do this. Their paper, appearing in this week's issue of Current Biology, is the first to demonstrate this navigation ability in any migrating animal.
Chapman and colleagues from Lund University in Sweden combed through radar data on thousands of individual insects and birds moving throughout northern Europe from 1999 through the present day. They checked the animals' migration paths, more than 10,000 examples in all. The team suspected a phenomenon called the Ekman spiral would provide their smoking gun.
The Ekman spiral is a consequence of the Coriolis Effect, which results from the Earth spinning on its axis. In the Northern Hemisphere, atmospheric currents shift clockwise with increasing altitudes, resulting in variable wind directions. This makes it difficult for migrating animals to tell which way the prevailing wind is blowing. Turbulence cues can therefore mislead them, causing them to over-correct. In the Northern Hemisphere, an animal trying to stay on course will tend to misalign itself slightly to the right of the downwind direction. In the Southern Hemisphere, they would err on the left.
Radar imaging showed the European moths did over-correct to the right, suggesting they're testing the winds rather than checking the ground below. A balloon rider wouldn't be able to detect the subtle directional changes at work in this study, which occur at fractions of meters per second. But for silver Y moths, it's a strong signal, Chapman said.
Songbirds weren't fooled, however, said Cecilia Nilsson, a coauthor at Lund University who studies bird migration. They showed no difference in response to turbulence, suggesting they instead use visual cues from the ground.
The moths are small and much more susceptible to buffeting by the wind; they also rely on it more heavily to move around, said Massimo Vergassola, a physicist at the University of California, San Diego who was not involved in the work. They would be under more evolutionary pressure than birds to attune themselves to the winds, he noted.
Vergassola studies how moths detect pheromones, enabling them to find mates.
"The problem is these chemicals are transported by the wind, and the winds are turbulent, exactly like in this case," he said. "The fact that they can sense turbulence and adjust is interesting for the kinds of studies we are doing. It's something that we had postulated, but we never had any evidence." Once upon a time, there lived a people we call the Natufians. They were among the first to quit their nomadic ways and settle on land where they grew crops, lived in complex settlements, put up stone buildings, domesticated dogs, and might have invented cemeteries before their society disappeared into the mists of history.
Israeli researchers now think they also may have developed a unique telegraph system to let everyone know when a catered funeral was underway and were among the first people to put up grave markers.
Natufian archaeological sites are common in Israel, Jordan, the Palestinian territories and Syria, said Dani Nadel, a professor at the Zinman Institute of Archaeology at the University of Haifa. There are some 400 Natufian skeletons in Israel and cave sites all over the region.
The Natufians lived from around 15,000-11,500 B.C., sometime after the retreat of the glaciers from the Ice Age. It likely was a time of great bounty, with wild versions of legumes and grains such as wheat and barley. Forests had grown back thick and lush; game was abundant.
They apparently also may have been the co-inventors of bread. Researchers at Bar Ilan University in Ramat Gan, Israel and Harvard University in Cambridge, Massachusetts, believe conical shaped structures the Natufians carved into rocks about 12,500 years ago could have been used to grind wild barley into food producing a "proto-pita." The making of bread is considered by archaeologists to be one of the keystones of civilization. The Natufians apparently did it more than 1,000 years before humans domesticated the grains.
That bounty of the land may account for the decision made by the Natufians to stop wandering and settle in communities, believed to be among the world's oldest villages. They created small settlements and were the first to build houses with stone foundations and plant crops, meaning they saved seeds, and replanted them.
Some of the ruins cover 13,000 square feet and include a thick layer of deposits, which indicates that people had lived there for longer than just a few months. Some of the round foundations are still standing 15,000 years later.
"It's amazing in my eyes," Nadel said.