ScienceDaily (Mar. 9, 2012) — Despite a century of research, memory encoding in the brain has remained mysterious. Neuronal synaptic connection strengths are involved, but synaptic components are short-lived while memories last lifetimes. This suggests synaptic information is encoded and hard-wired at a deeper, finer-grained molecular scale.
In an article in the March 8 issue of the journal PLoS Computational Biology, physicists Travis Craddock and Jack Tuszynski of the University of Alberta, and anesthesiologist Stuart Hameroff of the University of Arizona demonstrate a plausible mechanism for encoding synaptic memory in microtubules, major components of the structural cytoskeleton within neurons.
Microtubules are cylindrical hexagonal lattice polymers of the protein tubulin, comprising 15 percent of total brain protein. Microtubules define neuronal architecture, regulate synapses, and are suggested to process information via interactive bit-like states of tubulin. But any semblance of a common code connecting microtubules to synaptic activity has been missing. Until now.
Original paper here.
I found this scale of the universe on one of my favorite websites the other day and thought both the science and math departments would enjoy it. The link is to an interactive program that lets you zoom in and out in powers of ten and see the scale of the universe from the large (the visible universe) to the small (quantum foam). The program is a lot of fun and very interactive.
Our new articles editor Jeff Turrentine longs for the days of Reagan, when serious Republicans took science seriously.
Changing the texture of plastics on demand
Imagine a pair of rubber gloves whose surface texture could be altered on demand to provide more grip for climbing. Or maybe gloves with “fingerprints” that can be changed in the blink of an eye. They are just a couple of the many potential applications envisioned by researchers at Duke University for a process they have developed that allows the texture of plastics to be changed at will.
The new process follows on from the earlier work of Xuanhe Zhao, assistant professor of mechanical engineering and materials science at Duke’s Pratt School of Engineering, in which he was able to capture on video (see above) how polymers react to increasing voltages by first creasing and then developing large craters. Now, by applying specific voltages, Zhao and his team have been able to achieve the controlled alteration of the texture of plastics over large and curved surface areas.
“This new approach can dynamically switch polymer surfaces among various patterns ranging from dots, segments, lines to circles,” said Qiming Wang, a student in Zhao’s laboratory and the first author of a paper detailing the team’s findings. “The switching is also very fast, within milliseconds, and the pattern sizes can be tuned from millimeter to sub-micrometer.”
“The changeable patterns we have created in the laboratory include circles and straight and curved lines, which are basic elements of fingerprints,” Zhao said. “These elements can be dynamically patterned and changed on a glove surface that covers fingertips.”
For the more law abiding, Zhao adds, “however, the same technology can produce gloves with on-demand textures and smoothness tuned for various applications, such as climbing and gripping. Furthermore, surfaces capable of dynamically changing patterns are also useful for many technologies, such as microfluidics and camouflage.”
The globular cluster Messier 9 shines in this new photo from the Hubble Space Telescope. Credit: NASA & ESA
Hundreds of thousands of glittering stars shine in a cluster at the center of our galaxy in a new photograph from the Hubble Space Telescope.
The cluster is called Messier 9, and contains hordes of stars swarming in a spherical cloud about 25,000 light-years from Earth. The object is too faint to be seen with the naked eye, and when it was discovered by French astronomer Charles Messier in 1764, the scientist could only resolve it as a faint smudge that he classified as a nebula (“cloud” in Latin).
Now, though, the Hubble Space Telescope is powerful enough to make out more than 250,000 individual stars in Messier 9, in a new picture released today (March 16). The bluer points indicate hotter stars, while the redder stars are cooler.
Messier 9 is what’s known as a globular cluster, containing some of the oldest stars in the galaxy in a clump that is thought to have formed together when the universe was much younger. These stars, which are about twice as old as the sun, are made of different materials than our star. They tend to lack the sun’s heavier elements, such as oxygen, carbon and iron, which were only present in larger quantities when the universe was older.
Witness the Moon’s breathtaking 4.5-billion-year evolution in less than three minutes
When we gaze up at the Moon, we expect a certain degree of consistency. Sure, it moves through its phases, shifting in and out of darkness over the course of the month, but generally speaking, the Moon’s surface looks the same to us — night after night, year after year. But the Moon has not always looked the way it does now.
In the last 4.5 billion years, the Moon has transformed from a roiling mass of ejected terrestrial matter, to an unblemished orb, to the heavily cratered, volcanic-crust laden entity we know and love today. We know these things occurred because the Moon’s surface features tell a story, and for close to three years now, NASA’s Lunar Reconnaissance Orbiter has been getting an up close look at what those features have to say.
Now, the folks at NASA’s Goddard Multimedia team have used the latest data on the Moon’s history, acquired by LRO, to packr 4.5 billion years of lunar evolution into the stunning video you see up top.
A mesmerizing pattern of clouds surrounding southern Greenland was spotted by a NASA satellite in orbit around Earth.