NASA's Spitzer Finds Distant Galaxies Grazed On Gas

This split view shows how a normal spiral galaxy around our local universe (left) might have looked back in the distant universe, when astronomers think galaxies would have been filled with larger populations of hot, bright stars (right). (Credit: NASA/JPL-Caltech/STScI)

Science Daily  — Galaxies once thought of as voracious tigers are more like grazing cows, according to a new study using NASA's Spitzer Space Telescope.

"Our study shows the merging of massive galaxies was not the dominant method of galaxy growth in the distant universe," said Ranga-Ram Chary of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena, Calif. "We're finding this type of galactic cannibalism was rare. Instead, we are seeing evidence for a mechanism of galaxy growth in which a typical galaxy fed itself through a steady stream of gas, making stars at a much faster rate than previously thought."Astronomers have discovered that galaxies in the distant, early universe continuously ingested their star-making fuel over long periods of time. This goes against previous theories that the galaxies devoured their fuel in quick bursts after run-ins with other galaxies.

Chary is the principal investigator of the research, appearing in the Aug. 1 issue of the Astrophysical Journal. According to his findings, these grazing galaxies fed steadily over periods of hundreds of millions of years and created an unusual amount of plump stars, up to 100 times the mass of our sun.

"This is the first time that we have identified galaxies that supersized themselves by grazing," said Hyunjin Shim, also of the Spitzer Science Center and lead author of the paper. "They have many more massive stars than our Milky Way galaxy."

Galaxies like our Milky Way are giant collections of stars, gas and dust. They grow in size by feeding off gas and converting it to new stars. A long-standing question in astronomy is: Where did distant galaxies that formed billions of years ago acquire this stellar fuel? The most favored theory was that galaxies grew by merging with other galaxies, feeding off gas stirred up in the collisions.

Chary and his team addressed this question by using Spitzer to survey more than 70 remote galaxies that existed 1 to 2 billion years after the Big Bang (our universe is approximately 13.7 billion years old). To their surprise, these galaxies were blazing with what is called H alpha, which is radiation from hydrogen gas that has been hit with ultraviolet light from stars. High levels of H alpha indicate stars are forming vigorously. Seventy percent of the surveyed galaxies show strong signs of H alpha. By contrast, only 0.1 percent of galaxies in our local universe possess this signature.

Previous studies using ultraviolet-light telescopes found about six times less star formation than Spitzer, which sees infrared light. Scientists think this may be due to large amounts of obscuring dust, through which infrared light can sneak. Spitzer opened a new window onto the galaxies by taking very long-exposure infrared images of a patch of sky called the GOODS fields, for Great Observatories Origins Deep Survey.

Further analyses showed that these galaxies furiously formed stars up to 100 times faster than the current star-formation rate of our Milky Way. What's more, the star formation took place over a long period of time, hundreds of millions of years. This tells astronomers that the galaxies did not grow due to mergers, or collisions, which happen on shorter timescales. While such smash-ups are common in the universe -- for example, our Milky Way will merge with the Andromeda galaxy in about 5 billion years -- the new study shows that large mergers were not the main cause of galaxy growth. Instead, the results show that distant, giant galaxies bulked up by feeding off a steady supply of gas that probably streamed in from filaments of dark matter.

Chary said, "If you could visit a planet in one of these galaxies, the sky would be a crazy place, with tons of bright stars, and fairly frequent supernova explosions."

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for the agency's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech. Caltech manages JPL for NASA.

For more information about Spitzer, visithttp://www.nasa.gov/spitzer and http://spitzer.caltech.edu/

Scientists Use 'Optogenetics' to Control Reward-Seeking Behavior

Nerve cells in the nucleus accumbens (red) receive input from amygdala fibers (green). Optogenetic stimulation of these nerve fibers produces a rewarding effect in mice. (Credit: Stuber lab/UNC-Chapel Hill)

Science Daily — Using a combination of genetic engineering and laser technology, researchers at the University of North Carolina at Chapel Hill have manipulated brain wiring responsible for reward-seeking behaviors, such as drug addiction. The work, conducted in rodent models, is the first to directly demonstrate the role of these specific connections in controlling behavior.

"For most clinical disorders we knew that one region or another in the brain was important, however until now we didn't have the tools to directly study the connections between those regions," said senior study author Garret D. Stuber, PhD, assistant professor in the departments of cell and molecular physiology, psychiatry and the Neuroscience Center in UNC School of Medicine. "Our ability to perform this level of sophistication in neural circuit manipulation will likely to lead to the discovery of molecular players perturbed during neuropsychiatric illnesses."The UNC study, published online on June 29, 2011, by the journal Nature, uses a cutting-edge technique called "optogenetics" to tweak the microcircuitry of the brain and then assess how those changes impact behavior. The findings suggest that therapeutics targeting the path between two critical brain regions, namely the amygdala and the nucleus accumbens, represent potential treatments for addiction and other neuropsychiatric diseases.Because the brain is composed of diverse regions, cell types and connections in a compact space, pinpointing which entity is responsible for what function can be quite tricky. In the past, researchers have tried to get a glimpse into the inner workings of the brain using electrical stimulation or drugs, but those techniques couldn't quickly and specifically change only one type of cell or one type of connection. But optogenetics, a technique that emerged six years ago, can.In the technique, scientists transfer light-sensitive proteins called "opsins" -- derived from algae or bacteria that need light to grow -- into the mammalian brain cells they wish to study. Then they shine laser beams onto the genetically manipulated brain cells, either exciting or blocking their activity with millisecond precision.In Stuber's initial experiments, the target was the nerve cells connecting two separate brain regions associated with reward, the amygdala and the nucleus accumbens. The researchers used light to activate the connections between these regions, essentially "rewarding" the mice with laser stimulations for performing the mundane task of poking their nose into a hole in their cage. They found that the opsin treated mice quickly learned to "nosepoke" in order to receive stimulation of the neural pathway. In comparison, the genetically untouched control mice never caught onto the task.

Then Stuber and his colleagues wanted to see whether this brain wiring had a role in more natural behavioral processes. So they trained mice to associate a cue -- a light bulb in the cage turning on -- to a reward of sugar water. This time the opsin that the researchers transferred into the brains of their rodent subjects was one that would shut down the activity of neural connections in response to light. As they delivered the simple cue to the control mice, they also blocked the neuronal activity in the genetically altered mice. The control mice quickly began responding to the cue by licking the sugar-producing vessel in anticipation, whereas the treated mice did not give the same response.

The researchers are now exploring how changes to this segment of brain wiring can either make an animal sensitized to or oblivious to rewards. Stuber says their approach presents an incredibly useful tool for studying basic brain function, and could one day provide a powerful alternative to electrical stimulation or pharmacotherapy for neuropsychiatric illnesses like Parkinson's disease.

"For late-stage Parkinson's disease it has become more routine to use deep brain stimulation, where electrodes are chronically implanted into brain tissue, constantly stimulating the tissue to alleviate some of the disease symptoms," said Stuber. "From the technical perspective, implanting our optical fibers is not going to be more difficult than that. But there is quite a bit of work to be done before we get to that point."

The research was funded by NARSAD: The Brain & Behavior Research Fund; ABMRF/ The Foundation for Alcohol Research; The Foundation of Hope; and the National Institute on Drug Abuse, a component of NIH.

Study co-authors from Stuber's laboratory at UNC include Dennis R. Sparta, PhD, postdoctoral fellow, and Alice M. Stamatakis, graduate student.

Quantum 'Graininess' of Space at Smaller Scales? Gamma-Ray Observatory Challenges Physics Beyond Einstein

Gamma-ray burst captured by Integral's IBIS instrument. (Credit: ESA/SPI Team/ECF)

Science Daily  — The European Space Agency's Integral gamma-ray observatory has provided results that will dramatically affect the search for physics beyond Einstein. It has shown that any underlying quantum 'graininess' of space must be at much smaller scales than previously predicted.

One of the great concerns of modern physics is to marry these two concepts into a single theory of quantum gravity.Einstein's General Theory of Relativity describes the properties of gravity and assumes that space is a smooth, continuous fabric. Yet quantum theory suggests that space should be grainy at the smallest scales, like sand on a beach.Now, Integral has placed stringent new limits on the size of these quantum 'grains' in space, showing them to be much smaller than some quantum gravity ideas would suggest.According to calculations, the tiny grains would affect the way that gamma rays travel through space. The grains should 'twist' the light rays, changing the direction in which they oscillate, a property called polarisation.High-energy gamma rays should be twisted more than the lower energy ones, and the difference in the polarisation can be used to estimate the size of the grains.Philippe Laurent of CEA Saclay and his collaborators used data from Integral's IBIS instrument to search for the difference in polarisation between high- and low-energy gamma rays emitted during one of the most powerful gamma-ray bursts (GRBs) ever seen.GRBs come from some of the most energetic explosions known in the Universe. Most are thought to occur when very massive stars collapse into neutron stars or black holes during a supernova, leading to a huge pulse of gamma rays lasting just seconds or minutes, but briefly outshining entire galaxies.GRB 041219A took place on 19 December 2004 and was immediately recognised as being in the top 1% of GRBs for brightness. It was so bright that Integral was able to measure the polarisation of its gamma rays accurately.Dr Laurent and colleagues searched for differences in the polarisation at different energies, but found none to the accuracy limits of the data.Some theories suggest that the quantum nature of space should manifest itself at the 'Planck scale': the minuscule 10^-35of a metre, where a millimetre is 10^-3 m.

However, Integral's observations are about 10 000 times more accurate than any previous and show that any quantum graininess must be at a level of 10^-48 m or smaller.

"This is a very important result in fundamental physics and will rule out some string theories and quantum loop gravity theories," says Dr Laurent.

Integral made a similar observation in 2006, when it detected polarised emission from the Crab Nebula, the remnant of a supernova explosion just 6500 light years from Earth in our own galaxy.

This new observation is much more stringent, however, because GRB 041219A was at a distance estimated to be at least 300 million light years.

In principle, the tiny twisting effect due to the quantum grains should have accumulated over the very large distance into a detectable signal. Because nothing was seen, the grains must be even smaller than previously suspected.

"Fundamental physics is a less obvious application for the gamma-ray observatory, Integral," notes Christoph Winkler, ESA's Integral Project Scientist. "Nevertheless, it has allowed us to take a big step forward in investigating the nature of space itself."

Now it's over to the theoreticians, who must re-examine their theories in the light of this new result.

Loudest Animal Is Recorded for the First Time

The water boatman (Micronecta scholtzi), shown at the top left, is only 2mm long but is the loudest animal ever to be recorded, relative to its body size, outperforming all marine and terrestrial species. (Credit: Images courtesy of Dr. Jérôme Sueur, Muséum national d'Histoire naturelle, Paris)

Science Daily — Scientists have shown for the first time that the loudest animal on earth, relative to its body size, is the tiny water boatman, Micronecta scholtzi. At 99.2 decibels, this represents the equivalent of listening to an orchestra play loudly while sitting in the front row.

The song, used by males to attract mates, is produced by rubbing two body parts together, in a process called stridulation. In water boatmen the area used for stridulation is only about 50 micrometres across, roughly the width of a human hair. "We really don't know how they make such a loud sound using such a small area," says Dr. Windmill.The frequency of the sound (around 10 kHz) is within human hearing range and Dr. James Windmill of the University of Strathclyde, explains one clue as to how loud the animals are: "Remarkably, even though 99% of sound is lost when transferring from water to air, the song is so loud that a person walking along the bank can actually hear these tiny creatures singing from the bottom of the river."

The researchers, who are presenting their work at the Society for Experimental Biology Annual Conference in Glasgow, are now keen to bring together aspects of biology and engineering to clarify how and why such a small animal makes such a loud noise, and to explore the practical applications. Dr. Windmill explains: "Biologically this work could be helpful in conservation as recordings of insect sounds could be used to monitor biodiversity. From the engineering side it could be used to inform our work in acoustics, such as in sonar systems."

Clocking Neptune's Spin by Tracking Atmospheric Features

Science Daily — A day on Neptune lasts precisely 15 hours, 57 minutes and 59 seconds, according to the first accurate measurement of its rotational period made by the University of Arizona planetary scientist Erich Karkoschka.

"The rotational period of a planet is one of its fundamental properties," said Karkoschka, a senior staff scientist at the UA's Lunar and Planetary Laboratory. "Neptune has two features observable with the Hubble Space Telescope that seem to track the interior rotation of the planet. Nothing similar has been seen before on the four giant planets."His result is one of the most enormous improvements in determining the rotational period of a gas planet in almost 350 years since Italian astronomer Giovanni Cassini made the first observations of Jupiter's Red Spot. The discovery is published in Icarus, the official scientific publication of the Division for Planetary Sciences of the American Astronomical Society. Unlike the rocky planets -- Mercury, Venus, Earth and Mars -- which behave like solid balls spinning in a rather straightforward manner, the giant gas planets -- Jupiter, Saturn, Uranus and Neptune -- rotate more like big blobs of liquid. Since they are believed to consist mainly of ice and gas around a relatively small solid core, their rotation involves a lot of sloshing, swirling and roiling, making it difficult for astronomers to get an accurate grip on exactly how fast they spin around.

"If you looked at Earth from space, you'd see mountains and other features on the ground rotating with great regularity, but if you looked at the clouds, they wouldn't because the winds change all the time," Karkoschka explained. "If you look at the giant planets, you don't see a surface, just a thick cloudy atmosphere."

"On Neptune, all you see is moving clouds and features in the planet's atmosphere. Some move faster, some move slower, some accelerate, but you really don't know what the rotational period is, if there is even some solid inner core rotating."

In the 1950s, when astronomers built the first radio telescopes, they discovered that Jupiter sends out pulsating radio beams like a lighthouse in space. Those signals originate from a magnetic field generated by the rotation of the planet's inner core.

However, No clues about the other gas giants' rotation were available because any radio signals they may emit are being swept out into space by the solar wind and never reach Earth.

"The only way to measure radio waves is to send spacecraft to those planets," Karkoschka said. "When Voyager 1 and 2 flew past Saturn, they found radio signals and clocked them at exactly 10.66 hours, and they found radio signals for Uranus and Neptune. So based on those radio signals, we thought we knew the rotation periods of those planets."

But when the Cassini probe arrived at Saturn 15 years later, its sensors detected its radio period had changed by about 1 per cent. Karkoschka explained that because of its large mass, Saturn couldn't incur that much change in its rotation over such a short time.

"Because the gas planets are so big, they have enough angular momentum to keep them spinning at pretty much the same rate for billions of years," he said. "So something strange was going on."

Cassini's later discovery was even more puzzling that Saturn's northern and southern hemispheres appear to rotate at different speeds.

"That's when we realized the magnetic field is not like clockwork but slipping," Karkoschka said. "The interior is rotating and drags the magnetic field along, but because of the solar wind or other, unknown influences, the magnetic field cannot keep up with respect to the planet's core and lags behind."

Instead of spacecraft powered by billions of dollars, Karkoschka took advantage of what one might call the scraps of space science: publicly available images of Neptune from the Hubble Space Telescope archive. With unwavering determination and unmatched patience, he then pored over hundreds of images, recording every detail and tracking distinctive features over long periods of time.

Other scientists before him had observed Neptune and analyzed images, but nobody had sleuthed through 500 of them.

"When I looked at the images, I found Neptune's rotation to be faster than what Voyager observed," Karkoschka said. "I think the accuracy of my data is about 1,000 times better than what we had based on the Voyager measurements -- a huge improvement in determining the exact rotational period of Neptune, which hasn't happened for any of the giant planets for the last three centuries."

Two features in Neptune's atmosphere, Karkoschka discovered, stand out in that they rotate about five times more steadily than even Saturn's hexagon, the most regularly rotating feature known on any of the gas giants.

Named the South Polar Feature and the South Polar Wave, the features are likely vortices swirling in the atmosphere, similar to Jupiter's famous Red Spot, which can last long due to negligible friction. Karkoschka was able to track them over more than 20 years.

An observer watching the massive planet turn from a fixed spot in space would see both features appear exactly every 15.9663 hours, with less than a few seconds of variation.

"The regularity suggests those features are connected to Neptune's interior in some way," Karkoschka said. "How they are connected is up to speculation."

One possible scenario involves convection driven by warmer and cooler areas within the planet's thick atmosphere, analogous to hot spots within the Earth's mantle, giant circular flows of molten material that stay in the same location over millions of years.

"I thought the extraordinary regularity of Neptune's rotation indicated by the two features was something really special," Karkoschka said.

"So I dug up the images of Neptune that Voyager took in 1989, which have better resolution than the Hubble images, to see whether I could find anything else near those two features. I discovered six more features that rotate with the same speed. Still, they were too faint to be visible with the Hubble Space Telescope and visible to Voyager only for a few months, so we wouldn't know if the rotational period was accurate to the six digits. But they were really connected. So now we have eight features locked together on one planet, which is really exciting."

In addition to getting a better grip on Neptune's rotational period, the study could lead to a better understanding of the giant gas planets in general.

"We know Neptune's total mass, but we don't know how it is distributed," Karkoschka explained. "If the planet rotates faster than we thought, the mass has to be closer to the centre than we thought. These results might change the models of the planet's interior and could have many other implications."

New Theory On Origin of Birds: Enlarged Skeletal Muscles

Ostriches in South Africa's Kruger National Park. A developmental biologist is proposing a new theory of the origin of birds, which traditionally has been thought to be driven by the evolution of flight. The new theory credits the emergence of enlarged skeletal muscles as the basis for their upright two-leggedness, which led to the opportunity for other adaptive changes like flying or swimming. (Credit: © David Garry / Fotolia)

Science Daily — A developmental biologist at New York Medical College is proposing a new theory of the origin of birds, which traditionally has been thought to be driven by the evolution of flight. Instead, Stuart A. Newman, Ph.D., credits the emergence of enlarged skeletal muscles as the basis for their upright two-leggedness, which led to the opportunity for other adaptive changes like flying or swimming. And it is all based on the loss of a gene that is critical to the ability of other warm-blooded animals to generate heat for survival.

Dr. Newman draws on earlier work from his laboratory that provided evidence for the loss, in the common dinosaur ancestors of birds and lizards, of the gene for uncoupling protein-1 (UCP1). The product of this gene is essential for the ability of "brown fat," tissue that protects newborns of mammals from hypothermia, to generate heat. In birds, heat generation is mainly a function of skeletal muscles.Dr. Newman, a professor of cell biology and anatomy, studies the diversity of life and how it got that way. His research has always centered on bird development, though this current study, "Thermogenesis, muscle hyperplasia, and the origin of birds," also draws from paleontology, genetics, and the physiology of fat."Unlike the scenario in which the evolution of flight is the driving force for the origin of birds, the muscle expansion theory does not require functionally operative intermediates in the transition to flight, swimming, or winglessness, nor does it require that all modern flightless birds, such as ostriches and penguins, had flying ancestors. It does suggest that the extinction of non-avian dinosaurs may have been related to a failure to evolve compensatory heat-generating mechanisms in face of the loss of UCP1," says the scientist

The Smell of Danger: Rats Instinctively Avoid Compound in Carnivore Urine

Researchers have discovered a single compound found in high concentrations in the urine of carnivores that triggers an instinctual avoidance response in mice and rats. (Credit: © Oleg Kozlov / Fotolia)

Science Daily  — The mechanics of instinctive behavior are mysterious. Even something as simple as the question of how a mouse can use its powerful sense of smell to detect and evade predators, including species it has never met before, has been almost totally unknown at the molecular level until now.

Their findings were published online in the Proceedings of the National Academy of Science on June 20, 2011.David Ferrero and Stephen Liberles, neuroscientists at Harvard Medical School, have discovered a single compound found in high concentrations in the urine of carnivores that triggers an instinctual avoidance response in mice and rats. This is the first time that scientists have identified a chemical tag that would let rodents sense carnivores in general from a safe distance. The authors write that understanding the molecular basis of predator odor recognition by rodents will provide crucial tools to study the neural circuitry associated with innate behavior.The search began in 2006, when Stephen Liberles, now Assistant Professor of Cell Biology at Harvard Medical School, was working as a post-doc in the lab of Linda Buck. Buck was part of the team that won the Nobel Prize for identifying the receptors that allow olfactory neurons to detect odors. While in her lab, Liberles identified a new type of olfactory receptor, the trace amine-associated receptors (TAARs).Mice have about 1200 kinds of odor receptors, and 14 kinds of TAARs. In comparison, humans -- who rely more on vision than smell -- have about 350 odor receptors and five TAARs.Liberles's initial findings indicated that several of the TAARs detect chemicals found in mouse urine, including a chemical with enriched production by males. He wondered, could TAARs (which appear to have originally evolved from neurotransmitter receptors that mediate behavior and emotion) play a role in the social behavior of rodents? What other kinds of naturally occurring odors might they be able to detect?In Liberles's lab at Harvard Medical School, graduate student David Ferrero began a search for other natural compounds that were detected by the TAARs. Working with commercially available predator and prey urine (used by gardeners to keep pests out of their crops and by hunters to mask their own scent or as lures for prey), Ferrero discovered that one of the 14 TAARs, TAAR4, detected the odor of several carnivores.

It seemed they had found a kairomone, a chemical that works like a pheromone, except that it communicates between members of different species instead of members of the same species. Prior to this discovery, the only known rodent-carnivore kairomones were a volatile compound produced by foxes, but not in that of other predators, and two non-volatile compounds produced by cats and rats (which prey on mice). Volatile compounds aerosolize and can be smelled at great distances; non-volatile compounds need to be sniffed more directly, something that would not be helpful in avoiding a predator directly but rather their terrain.

"One of the things that's really new here is that this is a generalized predator kairomone that's volatile," said Ferrero.

For rodents, it's the smell of danger.

Ferrero identified the compound that activates TAAR4 as 2-phenylethylamine, a product of protein metabolism. He then obtained specimens from 38 species of mammals and found elevated levels of 2-phenylethylamineby 18 of 19 species of carnivores, but not by non-carnivores (including rabbits, deer, primates, and a giraffe).

"It's been known so long that predator odors are great rodent deterrents, but we've discovered one molecule that's a key part of this ecological relationship," Ferrero said.

In a series of behavior tests, rats and mice showed a clear, innate avoidance to the smell of 2-phenylethylamine. The behavioral studies were repeated using a carnivore samples that had been depleted of 2-phenylethylamine. Rats failed to show full avoidance of the depleted carnivore urine, indicating that 2-phenylethylamine is a key trigger for predator avoidance.

Lacking the gene for TAAR4, humans can't experience anything like what rodents do when they smell 2-phenylethylamine. To us, it has a mildly inoffensive odor. But trimethylamine, a related organic compound that activates TAAR5, a receptor found in humans, is deeply repugnant to people.

What happens between the receptors and the parts of the brain that trigger that avoidance behavior remains a mystery, one with direct medical relevance.

According to Liberles, "In humans, the parts of the brain that deal with likes and dislikes go awry in many diseases, like drug addiction, and predator odor responses have been used to model stress and anxiety disorders. Going from chemicals to receptors to neural circuits to behaviors is a Holy Grail of neuroscience."

"The neural circuits are like a black box, but here we have identified a chemical stimulant and a candidate receptor that trigger one behavior," Ferrero said. "We feel this is an important first step to understanding the neural circuitry of innate behavior."

This research was funded by the National Institute On Deafness And Other Communication Disorders.

DNA barcodes save rainforests

THE UNIVERSITY OF ADELAIDE

'DNA barcoding' allows for identification and tracking of individual logs or wood products. Image: szefei/iStockphoto Advances in DNA 'fingerprinting' and other genetic techniques led by Adelaide researchers are making it harder for illegal loggers to get away with destroying protected rainforests. DNA fingerprinting for timber products has grown in international recognition due to research led by the University of Adelaide that traces individual logs or wood products back to the forests where they came from. Professor Andrew Lowe, Director of the University's Australian Centre for Evolutionary Biology and Biodiversity, and Dr Hugh Cross, Molecular Biologist at the State Herbarium of South Australia, have been working with Singapore company Double Helix Tracking Technologies (DoubleHelix), a leader in applied genetics for forest trade and conservation. In a new paper published in the journal of the International Association of Wood Anatomists, Professor Lowe and Dr Cross say DNA science has made a number of key advances in the fight against illegal loggers. "Molecular marker methods have been applied to freshly cut wood for a number of years, and it's now also possible to extract and use genetic material from wood products and old samples of wood," Professor Lowe says. "We can use 'DNA barcoding' to identify species, 'DNA fingerprinting' to identify and track individual logs or wood products, and we can also verify the region the wood was sourced from. "The advancement of genetics technologies means that large-scale screening of wood DNA can be done cheaply, routinely, quickly and with a statistical certainty that can be used in a court of law. Importantly, these methods can be applied at a customs entry point to the country - certification documents can be falsified, but DNA cannot." An estimated 10 per cent of wood imported into Australia consists of illegally traded timber, which has been cut down outside designated logging areas or outside agreed environmental controls. Australian companies have been the first in the world to purchase timber products that use DNA fingerprinting, as part of proof of legal origin starting back in 2007 - European and American importers are now following suit. Jonathan Geach, a Director of DoubleHelix, says: "As the technology is now proven scientifically and commercially, we're looking at a large-scale application in the Congo Basin, as well as working with governments in Europe and America to tighten the grip on illegal timber trade. "Having Professor Lowe as a leading researcher from the University of Adelaide and as an active member of our team has been tremendously important in driving the role of DNA tracing in timber internationally." Professor Lowe says a number of improvements in genetic marker methods still need to be made, such as for old or degraded wood samples. "Nevertheless, the advances in the use of DNA to identify wood are exciting," he says. This research is closely aligned with another major project, to develop a 'DNA barcode' for every tree and grass species on earth. "The Barcode of Life projects will take five years to complete, but the information will lead to a step change in the way we can manage our species and ecosystems right across the globe," Professor Lowe says.

New toy helps kids with autism

VICTORIA UNIVERSITY OF WELLINGTON

"[Autistic children] often don't understand how they should control their voice and body." Image:Tramper2/iStockphoto A responsive, mechanised toy designed especially for autistic children six months and up has been created to teach positive play behaviours. 'Auti' develops speaking, touching, and collaborating skills. It shuts down in response to any negative behaviour such as hitting or screaming, but quickly responds to the slightest positive interaction such as speaking gently or stroking. Each sensor can be adjusted to respond appropriately to a child's individual characteristics.   "Autistic children find it difficult to play," says designer Helen Andreae, who developed Auti through an industrial design paper at Victoria University in the final year of her Honours degree last year under the supervision of lecturers Tim Miller and Edgar Rodríguez Ramírez.    "They have great difficulty using their imagination to develop even the simplest fictional scenarios and have even further difficulties playing with other children because they often don't understand how they should control their voice and body. This can scare other children away when they are trying to make friends.   "I have had an awareness of autism for a long time, through family discussions and through observing the autistic child of a friend. In developing my design challenge, I thought a toy which could help families dealing with autism would be a positive area to focus my energies on."   The toy was designed in consultation with a child psychologist who works with autistic children and a professor whose research specialty is teaching autistic children. Dr Peter Andreae from Victoria's School of Engineering and Computer Science did the computer programming.   Ms Andreae says the toy is currently a prototype, so she has only allowed children of friends and family to play with it to avoid damage.   "The response to it has been positive—children love the fluffiness of Auti which is made of possum fur," she says.   "If one day Auti was commercialised it would need further fine tuning and I'd look at broadening its functions for a range of teaching applications."

Ancient animals had powerful eyes

UNIVERSITY OF SOUTH AUSTRLIA

The compound eyes of a living insect - a predatory robber fly - showing the individual lenses. Image: University of Adelaide South Australian and international scientists have discovered that some ancient, primitive animals had excellent vision. The discovery has been revealed today in the prestigious journal Nature.   UniSA palaeontologist Dr Jim Jago, who was part of the research team, says evidence comes from Kangaroo Island fossils. He says the fossils, which are over 500 million years old, look like squashed eyes from a recently swatted fly.   “Our Nature paper reports extremely well preserved fossil eyes from Early Cambrian (approximately 515 million years old) rocks from Emu Bay on Kangaroo Island,” Dr Jago says.   “These are by far the most complicated eyes known from this period of earth’s history. Each eye is seven to nine millimetres across and comprises over 3000 tiny lenses.   “As yet, the animal to which these eyes belonged is unknown, but they may have belonged to a large shrimp like animal. However, the rock layers in which the eyes are preserved include a dazzling array of fossil marine animals, many being new to science. They include primitive trilobite-like creatures, bizarre armoured worms and large swimming predators.”   The Nature paper is titled: ‘Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia’. Authors are Dr Michael Lee from the SA Museum and University of Adelaide, Dr Jago, Dr Jim Gehling from SA Museum, Dr John Paterson from the University of New England, Dr Diego Garcia-Bellido from Madrid and Dr Greg Edgecome from the Natural History Museum in London. Dr Jago says modern insects and crustaceans have ‘compound eyes’ comprising hundreds or even thousands of individual lenses.   “They see their world as pixels, with more lenses meaning sharper vision,” he says.   “The fossil compound eyes have over 3000 lenses, giving them much sharper vision than anything previously found from rocks this old. The eyes are much more complex than anything found previously in rocks of similar age. The newly discovered eyes are as advanced as the eyes in many living insects such as robberflies. The arrangement and size of the lenses indicates that these eyes belonged to an active predator that was capable of seeing in low light.”   The Nature paper reports these eyes provide evidence that the rapid development of advanced vision helped drive the Cambrian explosion of life that began around 540 million years ago, the time when most modern animal groups first appeared and proliferated in the oceans of the Earth. Given the tremendous adaptive advantage conferred by powerful eyes for avoiding predators and locating food and shelter, there must have been tremendous evolutionary pressure to elaborate and refine vision, the scientists report.

Babies are specially attuned to our voices and emotions

 Neuroscience 

Young babies' brains are already specially attuned to the sounds of human voices and emotions, according to a report published online on June 30 in Current Biology.

Three- to seven-month-old infants showed more activation in a part of the brain when they heard emotionally neutral human sounds, such as coughing, sneezing, or yawning, than when they heard the familiar sounds of toys or water. That activity appeared in an area of the temporal lobe known in adults for its role in processing human vocalizations. The babies also showed greater response to sad sounds versus neutral ones in another part of the brain involved in emotion processing in adults.

The researchers say the discoveries fundamentally advance our understanding of infant development.

"Our results suggest that the infant temporal cortex is more mature than previously reported," said Evelyne Mercure of University College London. "It is a rare demonstration that specialized areas exist in the brain very early in development."

"It is probably because the human voice is such an important social cue that the brain shows an early specialization for its processing," added Anna Blasi of King's College London. "This may represent the very first step in social interactions and language learning."

The findings are consistent with earlier evidence that infants can extract subtle information from human speech. Newborns prefer to listen to their mother's voice and their mother tongue. Young infants also differentiate between the voices of men and women, children and adults.

In the new study, the researchers used functional magnetic resonance imaging (fMRI) to record brain responses in sleeping babies while they were presented with emotionally neutral, positive, or negative human vocalizations or nonvocal environmental sounds.

"We were very surprised to find that the area of the temporal cortex that responded to the human voice more than to environmental sounds was so similar in its location to the adult area showing the same specialization," Mercure said. "Infant fMRI is not an exact science, and finding results that were so similar to the adult literature was reassuring and surprising at the same time."

The findings in normally developing babies call into question what happens to this voice-specialized brain region in babies that go on to develop behavioral or neuropsychological disorders, such as autism or schizophrenia, in which social communication is affected.

"We are now carrying out more research in this area to help us understand how differences in brain development arise, if we can use these to accurately identify babies who will go on to suffer from disorders such as autism, and if they can be used to help measure the effectiveness of interventions," added study author Declan Murphy, also of King's College London.

Provided by Cell Press

"Babies are specially attuned to our voices and emotions." June 30th, 2011. http://medicalxpress.com/news/2011-06-babies-specially-attuned-voices-emotions.html

Posted by
Robert Karl Stonjek

Drink-fueled memory blackouts among students predict future injury risk

The higher the number of drink fuelled memory blackouts a student experiences, the greater is his/her risk of sustaining a future injury while under the influence, reveals research published online in Injury Prevention.

Memory blackouts refer to the inability to recall events; they do not refer to loss of consciousness as a result of drinking too much. Research indicates that alcohol alters nerve cell communication in the hippocampal region of the brain, which affects memory formation.

Hazardous drinking - and its consequences - "are pervasive on college campuses," say the authors, who report that around one in three students say they have experienced a memory blackout in the past year, and around one in 20 say they have had a period of drink fuelled amnesia within the past seven days. Women are just as likely to have blackouts as men, even though they drink less.

In 2001, around 600,000 college students were injured as a result of excess drinking in the USA, and in 2005 almost 2,000 died as a result of booze fuelled unintentional injuries.

The authors therefore wanted to find out if the number of times a student had a memory blackout as a result of drinking too much could usefully predict who might sustain a potentially serious injury while under the influence in the future.

They analysed data from almost 800 undergraduates and more than 150 postgraduate students at five universities in North America between 2004 and 2009, who were monitored for two years.

The students were taking part in the College Health Intervention Project Study (CHIPS), which compared the value of screening and brief doctor-led interventions versus nothing for problem drinking, assessed according to quantity and frequency.

During the previous 28 days, male problem drinkers had put away an average of just under 82 drinks (as opposed to units); their female peers had downed just under 59.

Men had more heavy drinking days, defined as five plus drinks, than women.

More than half of all the students had had one or more memory blackouts in the 12 months leading up to the start of the study; 7% reported six or more during this time.

Those aged between 18 and 20, "sensation seekers," and those clocking up the most heavy drinking days reported the highest number of blackouts.

The subsequent analysis showed that the overall prevalence of injury associated with alcohol was just over 25%, with women just as likely as men to be injured.

And the more blackouts they had, the greater was their risk of unintentional injury.

One to two memory blackouts increased the odds by 57%. With six or more memory blackouts, a student was almost three times as likely to sustain an injury.

"Our results suggest that memory blackout screening at student health services could be a useful tool in college alcohol related injury prevention," conclude the authors.

This would be more specific than simply asking a student how much s/he drinks, and would help pick up those whose drinking is disrupting their cognitive abilities, they add.

"It may be easier for a student to dismiss general health warnings on excessive alcohol drinking harms than to refute that his extreme alcohol drinking is causing impairment in brain function," they say.

Provided by British Medical Journal

"Drink-fueled memory blackouts among students predict future injury risk." June 30th, 2011. http://medicalxpress.com/news/2011-06-drink-fueled-memory-blackouts-students-future.html

Posted by
Robert Karl Stonjek