Πέμπτη 21 Νοεμβρίου 2013

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Evidence of jet in Milky Way's black hole

Posted: 20 Nov 2013 04:24 PM PST

Astronomers have long sought strong evidence that Sagittarius A*, the supermassive black hole at the center of the Milky Way, is producing a jet of high-energy particles. Finally they have found it.

Impacts of plant invasions become less robust over time: Invasive plants are more likely to be replaced by other 'invasives'

Posted: 20 Nov 2013 11:37 AM PST

Among the most impressive ecological findings of the past 25 years is the ability of invasive plants to radically change ecosystem function. Yet few if any studies have examined whether ecosystem impacts of invasions persist over time, and what that means for plant communities and ecosystem restoration.

Skeletal remains of 24,000-year-old boy raise new questions about first Americans

Posted: 20 Nov 2013 11:36 AM PST

Results from a DNA study of a young boy's skeletal remains believed to be 24,000 years old could turn the archaeological world upside down – it's been proven that nearly 30 percent of modern Native American's ancestry came from this youngster's gene pool, suggesting First Americans came directly from Siberia.

U.S. national survey finds frog abnormalities are rare

Posted: 20 Nov 2013 10:40 AM PST

A 10-year study by the US Fish and Wildlife Service shows some good news for frogs and toads on national wildlife refuges. The rate of abnormalities such as shortened or missing legs was less than 2 percent overall -- indicating that the malformations first reported in the mid-1990s were rarer than feared. But much higher rates were found in local "hotspots," suggesting that where these problems occur they have local causes.

3-D printing hits fast lane: Engineers cut time to 3-D-print heterogeneous objects from hours to minutes

Posted: 20 Nov 2013 10:37 AM PST

Three-dimensional printing has long had the potential to revolutionize manufacturing, but so far its application in the marketplace has been held back by slow fabrication, especially for heterogeneous objects. Many objects comprise more than one material, which allows for certain parts to be rigid while other parts remain flexible (e.g. tweezers; prosthetics). Scientists have now developed a 3-D printing process that fabricates such objects very time- and cost-efficiently.

Scientists break a theoretical time barrier on bouncing droplets

Posted: 20 Nov 2013 10:37 AM PST

Those who study hydrophobic materials -- water-shedding surfaces such as those found in nature and created in the laboratory -- are familiar with a theoretical limit on the time it takes for a water droplet to bounce away from such a surface. But researchers have now found a way to burst through that perceived barrier, reducing the contact time by at least 40 percent.

Listen to this: New research upends understanding of how humans perceive sound

Posted: 20 Nov 2013 10:37 AM PST

A key piece of the scientific model used for the past 30 years to help explain how humans perceive sound is wrong, according to a new study.

Secrets of Mars' birth revealed from unique meteorite

Posted: 20 Nov 2013 10:35 AM PST

As NASA prepares to launch a new Martian probe, a Florida State University scientist has uncovered what may be the first recognized example of ancient Martian crust. Using a powerful microprobe scientists dated special crystals within the meteorite -- called zircons -- at an astounding 4.4 billion years old.

Solar-powered battery woven into fabric overcomes hurdle for 'wearable electronics'

Posted: 20 Nov 2013 08:20 AM PST

Though some people already seem inseparable from their smartphones, even more convenient, wearable, solar-powered electronics could be on the way soon, woven into clothing fibers or incorporated into watchbands. This novel battery development could usher in a new era of "wearable electronics."

Computer searches web 24/7 to analyze images and teach itself common sense

Posted: 20 Nov 2013 08:19 AM PST

A computer program called the Never Ending Image Learner (NEIL) is running 24 hours a day searching the Internet for images, doing its best to understand them on its own and, as it builds a growing visual database, gathering common sense on a massive scale.

Brain activity in severely brain injured patients who 'wake up' with sleeping pill: Other patients may also respond

Posted: 20 Nov 2013 07:06 AM PST

George Melendez has been called a medical miracle. After a near drowning deprived his brain of oxygen, Melendez remained in a fitful, minimally conscious state until his mother, in 2002, decided to give him the sleep aid drug Ambien to quiet his moaning and writhing. The next thing she knew, her son was quietly looking at her and trying to talk. He has been using the drug ever since to maintain awareness, but no one could understand why Ambien led to such an awakening.

CT and 3-D printers used to recreate dinosaur fossils

Posted: 20 Nov 2013 05:14 AM PST

Data from computed tomography scans can be used with three-dimensional printers to make accurate copies of fossilized bones, according to new research.

World's first known magnetic cellulose loudspeakers: Potential for magnetic cellulose comes in crisp and clear

Posted: 20 Nov 2013 05:13 AM PST

They're flat, ultra-thin and great-sounding. The world's first known magnetic cellulose loudspeakers have been demonstrated.

The Galaxy's ancient brown dwarf population revealed

Posted: 20 Nov 2013 05:11 AM PST

Astronomers have discovered two of the oldest brown dwarfs in the Galaxy. These ancient objects are moving at speeds of 100-200 kilometers per second, much faster than normal stars and other brown dwarfs and are thought to have formed when the Galaxy was very young, more than 10 billion years ago.

Unexpected properties of methane-producing microbe

Posted: 18 Nov 2013 01:29 PM PST

Methanosaeta species are so active in some wetlands, they are considered the most prodigious methane producers on Earth. This is a concern because atmospheric methane is 20 times more effective at retaining heat than CO2, and as tundra soils warm due to climate change, greater methane releases are expected. Also, methane produced in anaerobic biomass digesters is economically important as "one of the few proven, economical, large-scale bioenergy strategies" in use today, the authors say.

Δεν υπάρχουν σχόλια:

Δημοσίευση σχολίου