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Scientists to Unearth Ice Age Secrets from Preserved Tree Rings

Kauri Tree
© University of OxfordNew Zealand's Kauri trees can measure up to four metres wide and live for up to 2,000 years.
Oxford University is involved in a research project to unearth 30,000 year old climate records, before they are lost forever. The rings of preserved kauri trees, hidden in New Zealand's peat bogs, hold the secret to climate fluctuations spanning back to the end of the last Ice Age.

The team, led by Exeter University, has been awarded a grant from the Natural Environment Research Council to carry out carbon dating and other analyses of the kauri tree rings. The trees store an immense amount of information about rapid and extreme climate change in the past. For instance, wide ring widths are associated with cool dry summer conditions. The scientists believe their findings will help us understand what future climate change may bring.

Tree rings are now known to be an excellent resource for extracting very precise and detailed data on atmospheric carbon from a particular time period. Therefore this study could help plug a large gap in our knowledge of climate change by extending historical weather records that only date back to the mid-nineteenth century.

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Scientists look to nature's template for flying machines

Locust in Windtunnel
© Animal Flight GroupUp and away: Wind tunnels help show how locusts can fly very long distances.
Sydney - Australian scientists are a step closer to creating a radical micro-aircraft after decoding the aerodynamic secrets of locusts, some of nature's most adept flyers.

The goal is to build miniature robots the size of a coin that could search for earthquake victims trapped deep in rubble or help the military chart the movements of insurgents in hostile terrain.

Teams from the University of New South Wales and collaborators at Oxford University in Britain exposed the locusts to wind-tunnel experiments and used high-speed digital video cameras to record how the shape of a locust's fast-moving wings changes in flight and to unlock the keys to the insect's manoeuvrability.

Researchers have, for the first time, been able to solve some of the mysteries that make the desert locust such a streamlined flyer. They constructed a three-dimensional map that demonstrates a complex flapping movement that allows the locust to travel vast distances on limited reserves of energy.

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Scientists on tenterhooks as 2-million-year-old skeleton takes a bow

A missing link between humans and their apelike ancestors has been discovered near Johannesburg in an area known as the Cradle of Humanity.

The new species of hominid, the evolutionary branch of primates that includes humans, will be revealed when the 2-million-year-old skeleton of a child is unveiled this week.

Scientists believe the almost-complete fossilised skeleton belonged to a previously unknown type of early human ancestor that may have been an intermediate stage as ape-men evolved into the first species of advanced humans, Homo habilis.

Experts who have seen the skeleton say it shares characteristics with Homo habilis, whose emergence 2.5 million years ago is seen as a key stage in the evolution of our species. It is thought it will be identified as a species that fits somewhere between Australopithicus and Homo habilis.

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Picking our brains: Why are some people smarter?

At Einstein's autopsy in 1955, his brain was something of a disappointment: it turned out to be a tad smaller than the average Joe's. Indeed, later studies have suggested a minimal link between brain size and intelligence. It seems brain quality rather than quantity is key.

One important factor seems to be how well our neurons can talk to each other. Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Center in the Netherlands, found that smarter brains seem to have more efficient networks between neurons - in other words, it takes fewer steps to relay a message between different regions of the brain. That could explain about a third of the variation in a population's IQ, he says.

Another key factor is the insulating fatty sheath encasing neuron fibres, which affects the speed of electrical signals. Paul Thompson at the University of California, Los Angeles, has found a correlation between IQ and the quality of the sheaths (The Journal of Neuroscience, vol 29, p 2212).

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Synapse on a Chip

memristor
© pubs.acs.org
The memristor - the so-called "missing link of electronics" memory technology that can change its resistance in varying levels - has been around on paper for nearly 40 years. However it wasn't until 2010 that a group at the University of Michigan led by Dr. Wei Lu demonstrated that it can be used to build brain-like computers in a paper just published in Nano Letters. New Scientist reports that "memristors can behave uncannily like the junctions between neurons in the brain." Scientific American describes a US military-funded project that is trying to use the memristor "to make neural computing a reality." DARPA's Systems of Neuromorphic Adaptive Plastic Scalable Electronics Program (SyNAPSE) is funded to create "electronic neuromorphic machine technology that is scalable to biological levels."

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New Written Language of Ancient Scotland Discovered

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© Rob Knell and Rob LeeRiders and horn blowers appear next to hunting dogs on what is called the Hilton of Cadboll stone, pictured here.
Once thought to be rock art, carved depictions of soldiers, horses and other figures are in fact part of a written language dating back to the Iron Age.

The Gist:
  • A new written language, belonging to the early Pict society of Scotland, has just been identified.
  • Stylized rock engravings have been found on hundreds of Pictish Stones.
  • If the writing can be deciphered, it would provide a unique insight into early Scottish history.
The ancestors of modern Scottish people left behind mysterious, carved stones that new research has just determined contain the written language of the Picts, an Iron Age society that existed in Scotland from 300 to 843.

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Andean mummies afflicted with arsenic

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© Elsevier / JASChinchorro mummy showing artificial mummification and long wig from 2000 B.C.
Andean mummies reveal arsenic poisoning afflicted people in northern Chile for thousands of years, a hair analysis shows.

In the current Journal of Archaeological Science, a team led by Bernardo Arriaza of Chile's Universidad de Tarapaca analyzed hair from 45 Andean mummies taken from ten sites some 7,000 to 600 years old. The mummies dried in Chile's Atacama desert region, one of the most parched regions on Earth. They were deliberately mummified with sticks, reeds and clay, given wigs and distinctive caps.

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Stone Age Scandinavians unable to digest milk

The hunter-gatherers who inhabited the southern coast of Scandinavia 4,000 years ago were lactose intolerant. This has been shown by a new study carried out by researchers at Uppsala University and Stockholm University. The study, which has been published in the journal BMC Evolutionary Biology, supports the researchers' earlier conclusion that today's Scandinavians are not descended from the Stone Age people in question but from a group that arrived later.

"This group of hunter-gatherers differed significantly from modern Swedes in terms of the DNA sequence that we generally associate with a capacity to digest lactose into adulthood," says Anna Linderholm, formerly of the Archaeological Research Laboratory, Stockholm University, presently at University College Cork, Ireland.

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Why Earth Wasn't One Big Ball of Ice 4 Billion Years Ago When Sun's Radiation Was Weaker

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© iStockphotoScientists have solved one of the great mysteries of our geological past: Why the Earth's surface was not one big lump of ice four billion years ago when sun radiation was much weaker than today.
Scientists have solved one of the great mysteries of our geological past: Why Earth's surface was not one big lump of ice four billion years ago when Sun radiation was much weaker than today. Scientists have presumed that Earth's atmosphere back then consisted of 30 percent CO2 trapping heat like a greenhouse. However, new research shows that the reason for Earth not going into a deep freeze at the time was quite different.

In 1972, the late, world famous astronomer Carl Sagan and his colleague George Mullen formulated "The faint early Sun paradox. " The paradox consisted in that Earth's climate has been fairly constant during almost four of the four and a half billion years that the planet has been in existence, and this despite the fact that radiation from the Sun has increased by 25-30 percent.

The paradoxical question that arose for scientists in this connection was why Earth's surface at its fragile beginning was not covered by ice, seeing that the Sun's rays were much fainter than they are today. Science found one probable answer in 1993, which was proffered by the American atmospheric scientist, Jim Kasting. He performed theoretical calculations that showed that 30% of Earth's atmosphere four billion years ago consisted of CO2. This in turn entailed that the large amount of greenhouse gases layered themselves as a protective greenhouse around the planet, thereby preventing the oceans from freezing over.

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Was a Giant Comet Responsible for a North American Catastrophe in 11,000 BC?

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© NASA05 Hubble Space Telescope image of the breakup of a comet (73/P Schwassmann-Wachmann 3).
Some 13,000 years ago the Earth was struck by thousands of Tunguska-sized cometary fragments over the course of an hour, leading to a dramatic cooling of the planet, according to astronomer Professor Bill Napier of the Cardiff University Astrobiology Centre.

He presents his new model in the journal Monthly Notices of the Royal Astronomical Society.

The cooling, by as much as 8°C, interrupted the warming which was occurring at the end of the last ice age and caused glaciers to re-advance. Evidence has been found that this catastrophic change was associated with some extraordinary extraterrestrial event. The boundary is marked by the occurrence of a "black mat" layer a few centimetres thick found at many sites throughout the United States containing high levels of soot indicative of continental-scale wildfires, as well as microscopic hexagonal diamonds (nanodiamonds) which are produced by shocks and are only found in meteorites or impact craters. These findings led to the suggestion that the catastrophic changes of that time were caused by the impact of an asteroid or comet 4 km across on the Laurentide ice sheet, which at that time covered what would become Canada and the northern part of the United States.