Science & TechnologyS


Fish

Barnacles' sticky secret revealed

Jody Bourton
BBC News
Mon, 19 Oct 2009 00:26 UTC
cross section of a barnacle
© Richard K. EverettInside out, a cross section of a barnacle
Barnacles are able to attach themselves to almost anything.

They are found clinging to the hulls of ships, the sides of rock pools and even to the skin of whales.

Just how they stick so steadfastly whilst underwater has remained a biochemical puzzle for scientists for many years.

Now researchers have solved this mystery, showing that barnacle glue binds together exactly the same way as human blood does when it clots.

Barnacles are crustaceans that live in shallow ocean environments.

As larvae they affix to hard substrates, then remain stationary for the rest of their lives.
To attach themselves to a surface, the barnacles secrete an adhesive substance.

Scientist knew the chemical properties of this glue, but not how these chemicals interact to create a sticky effect.
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Telescope

Lunar Impact Plume?


Space Weather
Sat, 17 Oct 2009 14:44 UTC
Image
© NASA
There was a plume after all. Observers on Earth had their doubts after LCROSS and its Centaur booster rocket hit the Moon on Friday, Oct. 9th. The twin lunar impacts failed to produce visible plumes of debris, prompting speculation that something had gone wrong. On the contrary, members of the LCROSS science team are now calling the experiment "a smashing success."

Fifteen seconds after the Centaur hit the shadowy floor of crater Cabeus, the LCROSS spacecraft flying 600 km overhead took the following picture of a plume measuring 6 to 8 km wide.

"There is a clear indication of a plume of vapor and fine debris," says LCROSS principal investigator Tony Colaprete of NASA/Ames. "The ejecta brightness appears to be at the low end of our predictions and this may be a clue to the properties of the material the Centaur hit."

Nine cameras and spectrometers on LCROSS captured every phase of the Centaur's impact: the intial flash, the debris plume, and the creation of the Centaur's crater. "We are blown away by the data returned," says Colaprete. "The team is working hard on the analysis and the data appear to be of very high quality."
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HAL9000

First Black Hole for Light Created on Earth

Anil Ananthaswamy
New Scientist
Wed, 14 Oct 2009 18:38 UTC
Light
© Qiang Cheng and Tie Jun CuiThe full-wave simulation result when light is incident to the black hole.
An electromagnetic "black hole" that sucks in surrounding light has been built for the first time.

The device, which works at microwave frequencies, may soon be extended to trap visible light, leading to an entirely new way of harvesting solar energy to generate electricity.

A theoretical design for a table-top black hole to trap light was proposed in a paper published earlier this year by Evgenii Narimanov and Alexander Kildishev of Purdue University in West Lafayette, Indiana. Their idea was to mimic the properties of a cosmological black hole, whose intense gravity bends the surrounding space-time, causing any nearby matter or radiation to follow the warped space-time and spiral inwards.
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Magnify

Scientists Scan the Brains of Mice Playing "Quake"

Brandon Keim
Wired
Wed, 14 Oct 2009 14:03 UTC
Image
© David Tank
By putting sensors in the brains of mice as they ran through a Quake-derived virtual reality, scientists have found a way to study neurological activity in moving animals.

The setup allows for real-time, almost-real-motion tracking of single neurons. That feat has eluded researchers who have a fuzzy, general understanding of brain systems, but little knowledge of how individual cells actually work. They hope that cell-level details will make sense of motion, cognition and other complex mental functions.

"One of the major research areas of neuroscience is the development of techniques to study the brain at cellular resolution," said Princeton University neuroscientist David Tank, co-author of the study published Wednesday in Nature. "The information of the nervous system is contained in the activity of individual neurons."

Tank's team studied hippocampal place neurons, which are activated when an animal is in a particular location in its environment. Ever since hippocampal place neurons were identified 40 years go, scientists have wondered exactly what mechanisms make them fire.
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Magnify

Study Finds Unique Wasp Brain Abilities


United Press International
Thu, 15 Oct 2009 16:55 UTC
U.S. scientists studying the tiny brain of tropical paper wasps have found how the brain architecture changes as the wasps engage in specialized tasks.

Researchers at the Universities of Washington and Texas say previous studies had determined parts of the brains of the wasp species (Polybia aequatorialis) enlarged as the animal engaged in more complex tasks.

The new research describes how that occurs as dendrites, or extensions from individual neurons, reach out to receive information from other brain cells and form a dense network of connections. The networks help the wasps integrate information from visual, olfactory and touch sensory systems, the scientists said.

"I was astounded when we found that some of the individual neurons had dendrites that were seven to eight millimeters long in a brain that is roughly the size of two grains of sand," said study co-author Sean O'Donnell, a University of Washington associate professor of psychology.
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Magnify

From Thought to Speech in a Fraction of a Second

Karen Kaplan
Los Angeles Times
Fri, 16 Oct 2009 06:00 UTC
X-ray
© Ned T. SahinThis X-ray shows the electrodes used to identify the part of the brain that's responsible for seizures in patients with epilepsy. Scientists used the setup to study how the brain forms words. See more images
The human brain has to do quite a lot just to utter a single word. In the case of verbs, it must select the word that best expresses the idea it wants to convey (for instance, "to walk"); decide on the proper tense ("walks," "walked," "walking," etc.); figure out whether adding an "-ed" also adds another syllable; determine whether the word should end with a "d" or a "t" sound; and devise a plan for maneuvering the mouth muscles to make the appropriate sounds.

How does this happen? Neuroscientists, linguists and others have been debating whether the brain gets all this done by splitting up the jobs and completing them simultaneously or by finishing this litany of tasks one at a time.

Now, a trio of epilepsy patients has provided the answer. A small section of the cortex called Broca's area completes all these tasks sequentially, and all within about half a second, according to a study published Friday in the journal Science.

Scientists can study all kinds of diseases in animals, but when it comes to investigating language, only human brains will do. So researchers at UC San Diego and Harvard piggybacked on a rare procedure called intracranial electrophysiology, in which epilepsy patients allow doctors to implant dozens of electrodes directly into their brains. While they are awake, the patients answer questions so that doctors can determine which parts of the brain are necessary to maintain language and which parts can be safely removed to treat epileptic seizures.
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Telescope

Galactic Magnetic Fields May Control Boundaries of Our Solar System


ScienceDaily
Sat, 17 Oct 2009 04:00 UTC
The first all-sky maps developed by NASA's Interstellar Boundary Explorer (IBEX) spacecraft, the initial mission to examine the global interactions occurring at the edge of the solar system, suggest that the galactic magnetic fields had a far greater impact on Earth's history than previously conceived, and the future of our planet and others may depend, in part, on how the galactic magnetic fields change with time.

"The IBEX results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region," says Dr. David J. McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute. "We expected to see small, gradual spatial variations at the interstellar boundary, some 10 billion miles away. However, IBEX is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky."

A "solar wind" of charged particles continuously travels at supersonic speeds away from the Sun in all directions. This solar wind inflates a giant bubble in interstellar space called the heliosphere - the region of space dominated by the Sun's influence in which the Earth and other planets reside. As the solar wind travels outward, it sweeps up newly formed "pickup ions," which arise from the ionization of neutral particles drifting in from interstellar space. IBEX measures energetic neutral atoms (ENAs) traveling at speeds of roughly half a million to two and a half million miles per hour. These ENAs are produced from the solar wind and pick-up ions in the boundary region between the heliosphere and the local interstellar medium.
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Telescope

Morning Planets In Motion


Space Weather
Sat, 17 Oct 2009 14:49 UTC
Image
© Laurent Laveder
Yesterday in Bretagne, France, photographer Laurent Laveder woke before dawn to watch Venus, Saturn and the Moon rise together over a local marina. "I made a 50-minute, 22-megabyte movie of the event," he says.

"The show was cut short by the arrival of the clouds, but it was great anyway!" he says. Challenge: Watch the movie again and find the blue heron. It's asleep on one of the boats.

More images: from Miguel Claro of Cacilhas, Almada, Portugal; from Azhy Chato Hasan of Erbil city, Kurdistan Region, Iraq; from Marco Meniero of Roma, Italy; from Mohammad Mehdi Asgari of Arak, Iran; from Mark Staples of Little Lake Santa Fe, Waldo, FL; from James W. Young near San Bernardino, CA; from Mohammad Javad Fahimi at the Jabaliyeh Dome in Kerman, Iran; from Todd Carlson of Burk's Falls, Ontario, Canada; from Antonio Finazzi of Chiuduno, Bergamo - Italy; from Jens Hackmann of Weikersheim, southern Germany
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Powertool

Shale and our water: New York Times editorial


nytimes.com
Fri, 16 Oct 2009 07:53 UTC
New York State's environmental regulators have proposed rules to govern drilling in the Marcellus Shale - a subterranean layer of rock curving northward from West Virginia through Ohio and Pennsylvania to New York's southern tier. The shale contains enormous deposits of natural gas that could add to the region's energy supplies and lift New York's upstate economy. If done carefully - and in carefully selected places - drilling should cause minimal environmental harm.

But regulators must amend the rules to bar drilling in the New York City watershed: a million acres of forests and farmlands whose streams supply the reservoirs that send drinking water to eight million people. Accidental leaks could threaten public health and require a filtration system the city can ill afford.
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Sherlock

Sunken Settlement in Greece - Atlantis?

Helena Smith
Guardian
Sat, 17 Oct 2009 07:47 UTC
Image
© HandoutA diver explores the sunken settlement beneath the waters off southern Greece.
The secrets of a lost city that may have inspired one of the world's most enduring myths - the fable of Atlantis - have been brought to light from beneath the waters off southern Greece.

Explored by an Anglo-Greek team of archaeologists and marine geologists and known as Pavlopetri, the sunken settlement dates back some 5,000 years to the time of Homer's heroes and in terms of size and wealth of detail is unprecedented, experts say.

"There is now no doubt that this is the oldest submerged town in the world," said Dr Jon Henderson, associate professor of underwater archaeology at the University of Nottingham. "It has remains dating from 2800 to 1200 BC, long before the glory days of classical Greece. There are older sunken sites in the world but none can be considered to be planned towns such as this, which is why it is unique."
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