New charcoal and plant microfossil evidence from Mexico's Central Balsas valley links a pivotal cultural shift, crop domestication in the New World, to local and regional environmental history. Agriculture in the Balsas valley originated and diversified during the warm, wet, postglacial period following the much cooler and drier climate in the final phases of the last ice age. A significant dry period appears to have occurred at the same time as the major dry episode associated with the collapse of Mayan civilization, Smithsonian researchers and colleagues report in the Proceedings of the National Academy of Sciences online.
"Our climate and vegetation studies reveal the ecological settings in which people domesticated plants in southwestern Mexico. They also emphasize the long-term effects of agriculture on the environment," said Dolores Piperno, curator of archaeobotany and South American archaeology at the Smithsonian's National Museum of Natural History and the Smithsonian Tropical Research Institute in Panama.
Science & Technology
In a simple experiment on a mixture of water, surfactant (soap), and an organic salt, two researchers working in the Pritchard Fluid Mechanics Laboratory at Penn State have shown that a rigid object like a knife passes through the mixture at slow speeds as if it were a liquid, but rips it up as if it were a rubbery solid when the knife moves rapidly.
The mixture they study shares properties of many everyday materials -- like toothpaste, saliva, blood, and cell cytoplasm -- which do not fall into the standard textbook cases of solid, liquid, or gas. Instead, these "viscoelastic" materials can have the viscous behavior of a fluid or the elastic behavior of a solid, depending on the situation. The results of these experiments, which are published in the current issue of the journal Physical Review Letters and are featured on its cover, provide new insights into how such materials switch over from being solid-like to being liquid-like.
The mixture they study shares properties of many everyday materials -- like toothpaste, saliva, blood, and cell cytoplasm -- which do not fall into the standard textbook cases of solid, liquid, or gas. Instead, these "viscoelastic" materials can have the viscous behavior of a fluid or the elastic behavior of a solid, depending on the situation. The results of these experiments, which are published in the current issue of the journal Physical Review Letters and are featured on its cover, provide new insights into how such materials switch over from being solid-like to being liquid-like.
A man has made a potentially exciting archaeological discovery while diving with seals off the north Northumberland coast.
Dr Ben Burville, 38, has been diving for more than 22 years and for the last seven has specialised in swimming with seals and other marine mammals.
Dr Ben Burville, 38, has been diving for more than 22 years and for the last seven has specialised in swimming with seals and other marine mammals.
A Swiss computer services firm is offering to stock sensitive business data for companies in secure servers located in ex-army bunkers deep beneath the Alps.
The company, C-Channel, which specialises in banking software, claims that the data will be stocked "deep beneath the ground, protected from theft, fire, computer viruses and hackers."
"We have already set up several servers in two disused bunkers in the Alps," Rene Reinli, a company executive told AFP.
The company says the service amounts to a "Swiss Fort Knox," in deference to the fortress which houses the US gold reserves.
The company, C-Channel, which specialises in banking software, claims that the data will be stocked "deep beneath the ground, protected from theft, fire, computer viruses and hackers."
"We have already set up several servers in two disused bunkers in the Alps," Rene Reinli, a company executive told AFP.
The company says the service amounts to a "Swiss Fort Knox," in deference to the fortress which houses the US gold reserves.
Canadian physicists have cracked a decades-old mystery surrounding metals that carry electricity without resistance, opening the door for everyday trains that levitate on magnetic fields, ultrapowerful quantum computers and big savings for utilities.
ESMo Technologies has developed a magentic device which can maintain the freshness of food.
|
| ©Electric New Paper |
| Mr Sebestian Chua (left) and his brother, Dr. Richard Chua, hope the EsmoSphere will add another level of protection over food storage. |
The latest find from an international planet-hunting team of amateur and professional astronomers is one of the oddest extrasolar planets ever cataloged -- a mammoth orb more than 13 times the mass of Jupiter that orbits its star in less than four days.
Researchers from the U.S.-based XO Project unveiled the planet, XO-3b, at today's American Astronomical Society meeting in Honolulu. Christopher Johns-Krull, a Rice University astronomer and presenter of the team's results, said, "This planet is really quite bizarre. It is also particularly appropriate to be announcing this find here, since the core of the XO project is two small telescopes operating here in Hawaii."
Researchers from the U.S.-based XO Project unveiled the planet, XO-3b, at today's American Astronomical Society meeting in Honolulu. Christopher Johns-Krull, a Rice University astronomer and presenter of the team's results, said, "This planet is really quite bizarre. It is also particularly appropriate to be announcing this find here, since the core of the XO project is two small telescopes operating here in Hawaii."
Above ground, Mars is mostly a bone-chilling desert pocked with craters. Hundreds of miles below, however, a molten sea of iron, nickel and sulfur churns. And new research suggests the gooey core will eventually solidify-either from the outside-in, forming an iron-nickel core, or from the inside out, forming a core of a fool's-gold-like minerals.
Andrew Stewart, a planetary geochemist at the Swiss Federal Institute of Technology, said Mars' cooling core might restore magnetism to the red planet. "If liquid metal moves around a solid core, it could create a natural dynamo like the one found in Earth's core," said Stewart, who co-authored the study detailed in today's online edition of the journal Science.
Liquids turn solid at different temperatures when pressure or purity are changed-dry ice, for example, is carbon dioxide gas squeezed under immense pressure. Add impurities to ice, and its freezing point is lowered (which is why roads are salted). Likewise, explained Stewart, sulfur mixes things up under Mars' crushing pressure of 5.8 million pounds per square inch.
Andrew Stewart, a planetary geochemist at the Swiss Federal Institute of Technology, said Mars' cooling core might restore magnetism to the red planet. "If liquid metal moves around a solid core, it could create a natural dynamo like the one found in Earth's core," said Stewart, who co-authored the study detailed in today's online edition of the journal Science.
Liquids turn solid at different temperatures when pressure or purity are changed-dry ice, for example, is carbon dioxide gas squeezed under immense pressure. Add impurities to ice, and its freezing point is lowered (which is why roads are salted). Likewise, explained Stewart, sulfur mixes things up under Mars' crushing pressure of 5.8 million pounds per square inch.
It's a toy that most kids have played with at one time or another, but the findings of Northeastern University Computer Science professor Gene Cooperman and graduate student Dan Kunkle are not child's play. The two have proven that 26 moves suffice to solve any configuration of a Rubik's cube - a new record. Historically the best that had been proved was 27 moves.
Why the fascination with the popular puzzle?
"The Rubik's cube is a testing ground for problems of search and enumeration," says Cooperman. "Search and enumeration is a large research area encompassing many researchers working in different disciplines - from artificial intelligence to operations. The Rubik's cube allows researchers from different disciplines to compare their methods on a single, well-known problem."
Cooperman and Kunkle were able to accomplish this new record through two primary techniques: They used 7 terabytes of distributed disk as an extension to RAM, in order to hold some large tables and developed a new, "faster faster" way of computing moves, and even whole groups of moves, by using mathematical group theory.
Why the fascination with the popular puzzle?
"The Rubik's cube is a testing ground for problems of search and enumeration," says Cooperman. "Search and enumeration is a large research area encompassing many researchers working in different disciplines - from artificial intelligence to operations. The Rubik's cube allows researchers from different disciplines to compare their methods on a single, well-known problem."
Cooperman and Kunkle were able to accomplish this new record through two primary techniques: They used 7 terabytes of distributed disk as an extension to RAM, in order to hold some large tables and developed a new, "faster faster" way of computing moves, and even whole groups of moves, by using mathematical group theory.
Animals differ strikingly in character and temperament. Yet only recently has it become evident that personalities are a widespread phenomenon in the animal kingdom. Animals as diverse as spiders, mice and squids appear to have personalities. Personality differences have been described in more than 60 species, including primates, rodents, birds, fish, insects and mollusks. New work by Max Wolf (University of Groningen; currently at the Santa Fe Institute), Santa Fe Institute Postdoctoral Fellow Sander van Doorn, Franz Weissing (University of Groningen), and Olof Leimar (Stockholm University) offers an explanation for the evolution of animal personalities. Their findings are detailed in "Life-history trade-offs favour the evolution of animal personalities" in the May 31 issue of Nature.
The evolutionary origins of "animal personality" - defined as consistent behavior over time and in different situations - is poorly understood. Why do different personality types exist within a single population given that, at first sight, one would expect one type to be more successful than another" Why are individuals not more flexible considering that personality rigidity sometimes leads to seemingly inefficient behavior" Why do we find the same types of traits correlated with each other in very different kinds of animals"
The authors argue that in many cases personalities are shaped by a simple underlying principle: the more an individual stands to lose (in terms of future reproduction) the more cautiously it is likely to behave, in all kinds of situations and consistently over time.
The evolutionary origins of "animal personality" - defined as consistent behavior over time and in different situations - is poorly understood. Why do different personality types exist within a single population given that, at first sight, one would expect one type to be more successful than another" Why are individuals not more flexible considering that personality rigidity sometimes leads to seemingly inefficient behavior" Why do we find the same types of traits correlated with each other in very different kinds of animals"
The authors argue that in many cases personalities are shaped by a simple underlying principle: the more an individual stands to lose (in terms of future reproduction) the more cautiously it is likely to behave, in all kinds of situations and consistently over time.
Comment: Esmo Technologies has also invented a handy, dandy magnet which 'ages wine' and 'softens hard liquor'. You can try it but you need to go to Singapore.