A new modeling approach using sea ice motion data to follow parcels of ice backward in time at monthly intervals for up to 3 years while accumulating a history of the solar radiation and air temperature to which the ice was exposed offers new hope for increased accuracy in climate change models, say scientists with the U.S. Geological Survey and the Russian Academy of Sciences, Moscow. This is the only model based entirely on historical observations.
Using this new technique, the thickness of Arctic sea ice was estimated from 1982 to 2003. Results showed that average ice thickness and total ice volume fluctuated together during the early study period, peaking in the late 1980s and then declining until the mid-1990s. Thereafter, ice thickness slightly increased but the total volume of sea ice did not increase.
A 10-cent pill doesn't kill pain as well as a $2.50 pill, even when they are identical placebos, according to a provocative study by Dan Ariely, a behavioral economist at Duke University.
"Physicians want to think it's the medicine and not their enthusiasm about a particular drug that makes a drug more therapeutically effective, but now we really have to worry about the nuances of interaction between patients and physicians," said Ariely, whose findings appear as a letter in the Journal of the American Medical Association.
A national database containing images of ballistic markings from all new and imported guns sold in the U.S. should not be created at this time, says a new report from the National Research Council. Such a database has been proposed to help investigators link ballistics evidence -- cartridge cases or bullets found at crime scenes -- to a firearm and the location where it was originally sold.
But given the practical limitations of current technology for generating and comparing images of ballistic markings, searches of such an extensive database would likely produce too many candidate "matches" to be helpful, the report says.
Hardware piracy - making knock-off microchips based on stolen blueprints - has long been a chronic problem in the electronics industry. Computer engineers at the University of Michigan and Rice University have devised a comprehensive way to head off this costly infringement: Each chip would have its own unique lock and key. The patent holder would hold the keys. The chip would securely communicate with the patent-holder to unlock itself, and it could operate only after being unlocked.
The technique is called EPIC, short for Ending Piracy of Integrated Circuits. It relies on established cryptography methods and introduces subtle changes into the chip design process. But it does not affect the chips' performance or power consumption.
According to quantum mechanics, small magnetic objects called nanomagnets can exist in two distinct states (i.e. north pole up and north pole down). They can switch their state through a phenomenon called quantum tunneling.
When the nanomagnet switches its poles, the abrupt change in its magnetization can be observed with low-temperature magnetometry techniques used in del Barco’s lab. The switch is called quantum tunneling because it looks like a funnel cloud tunneling from one pole to another.
A new paper in Nature shows that two almost independent halves of a new magnetic molecule can tunnel, or switch poles, at once under certain conditions. In the process, they appear to cancel out quantum tunneling.
Research from ancient sediment cores indicates that a warming climate could make the world’s arctic tundra far more susceptible to fires than previously thought. The findings are important given the potential for tundra fires to release organic carbon – which could add significantly to the amount of greenhouse gases already blamed for global warming.
Montana State University post-doctoral researcher Philip Higuera is the lead author on the paper, which summarizes a portion of a four-year study funded by the National Science Foundation.