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Polar Bears at Risk!
Dino Ducks! Vampire Bats!
Neptune's Trojans! Erotic Images!
Brain-Computer Interface!
Polar Bears at Risk!
University of Chicago News Release

June 16, 2006 - A climate scientist at the University of Chicago and 30 of her colleagues from across North America and Europe are urging the U.S. Fish and Wildlife Service to list the polar bear as a threatened species because global warming is melting its sea-ice habitat.

"As scientists engaged in research on climate change, we are deeply concerned about the effect of Arctic warming on the polar bear habitat," said a letter submitted to the Fish and Wildlife Service on June 15. "Biologists have determined that sea-ice is critical in the life cycle of the polar bear and the survival of the polar bear as a species.

Under the Endangered Species Act, the Fish and Wildlife Service is required to list a species for protection if it is in danger of extinction or threatened by possible extinction in all or a significant portion of its range. The ongoing and projected increased loss of sea-ice in the warming Arctic poses a significant threat to the polar bear."

The letter was not a petition, said Pamela Martin, Assistant Professor in Geophysical Sciences at the University of Chicago, who organized the effort. "Rather, it was a letter summarizing some key aspects of the best available science on global warming and, in particular, Arctic warming.

"The polar bear listing petition is really illustrative of the challenge in addressing many environmental problems facing us as a global community. These problems don't fit squarely within a single scientific discipline--they not only require scientists to talk across disciplines, such as the geophysical and biological sciences as in the case of the polar bear, but also across the larger divide that separates scientists from policy makers."

The non-profit Center for Biological Diversity, based in Tucson, Ariz., filed a scientific petition with the Fish and Wildlife Service on Feb. 16, 2005, to list the polar bear as a threatened species under the Endangered Species Act. In February 2006, the Fish and Wildlife Service announced that it would initiate a status review of the polar bear to determine if the species should be proposed for listing. A 60-day public comment period, later extended, also began on Feb. 9.

Martin wrote and circulated the letter with the help of four colleagues in the University of Chicago Department of Geophysical Sciences: Gidon Eshel, Assistant Professor; David Archer, Professor; Douglas MacAyeal, Professor; and Ray Pierrehumbert, Louis Block Professor.

"Unlike many letters that circulate, this one did not circulate with the names of the signers," Martin said. "Thus, with the exception of the names of my colleagues from this institution, the scientists signed it blind with respect to other signators."

The letter states that "the best available observations demonstrate that Arctic warming is rapid, persistent, and widespread," and that only a reduction of technologically generated greenhouse gases can prevent further Arctic warming and sea-ice melting. The scientists summarized multiple lines of evidence that point to global warming trends, especially in the Arctic:

  • An increase in surface temperatures of nearly 1 degree Fahrenheit since the late 19th century
  • Warming of the world's oceans over the last 50 years
  • Thawing of the northern high latitude permafrost (ground that was formerly frozen year-round)
  • Increased evaporation over the tropics and subtropics
  • An increase in the rate of sea-level rise

"In the Arctic, evidence from satellite data, submarine data, and oceanographic field observations reveal the diminished areal extent, shorter seasonal duration, and extensive thinning of sea ice," the letter said. "Summer sea ice cover in the Arctic has already been reduced in areal extent by 10-20 percent over the last 30 years."

The Arctic region is especially sensitive to global warming because of the reflectivity of ice and cloud cover, the scientists said. Despite slight cooling in some pockets of the Artic, overall the region has experienced substantial warming. Records show that average annual temperatures are 3.5 to 5 degrees Fahrenheit warmer in Alaska and Siberia. Siberian winters and temperatures in the western Canadian Arctic, meanwhile, are 7 degrees warmer than before, the letter said.

The scientists also cited the 2001 Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Pierrehumbert served as lead author of this report, which involved the participation of more than 2,000 scientists from 100 countries. "The IPCC report concluded that the observed global climate changes cannot be accounted for by natural climate forcings alone;" said the scientists in their letter.

Additional research conducted since 2001 has strengthened the IPCC's findings, according to Martin and her colleagues. "In 2005, the Arctic Council, an intergovernmental forum with members from eight nations, including the United States, referenced the findings of the IPCC Third Assessment Report in their Arctic Climate Assessment and added that 'there is new and strong evidence that in the Arctic much of the observed warming over this period [the last 50 years] is also due to human activities."

Taking into account increasing temperatures and atmospheric carbon dioxide, along with fundamental climate theory, the scientists observe that global surface temperature is currently unstable, or, in scientific terms, "not in a steady state," nor will it be for years to come. The planet is, as a result, committed to a continued trend in global warming for centuries to come, according to the scientists.

"Immediate reductions of greenhouse gas emissions well beyond those that may be considered by some measures 'sustainable' emissions rates are therefore imperative. We urge the Fish and Wildlife Service to acknowledge the threat of Arctic warming on the Polar Bear."

University of Chicago -

Dino Ducks!

Reconstruction of the Early Cretaceous (~110-115
million year old) amphibious bird Gansus
yumenensis. Despite its antiquity, Gansus is
remarkably closely related to modern birds -
the most advanced Early Cretaceous bird yet
discovered. (Mark A. Klingler/ CMNH)
University of Pennsylvania News Release

June 15, 2006 - Five fossil specimens of a near-modern bird found in the Gansu Province of northwestern China show that early birds likely evolved in an aquatic environment, according to a study reported today in the journal Science. Their findings suggest that these early modern birds were much like the ducks or loons found today. Gansus yumenesis, which lived some 105 to 115 million years ago during the Early Cretaceous period, took modern birds through a watery path out of the dinosaur lineage.

The report was co-authored by Peter Dodson of the University of Pennsylvania and his former students Hai-lu You of the Chinese Academy of Geological Sciences, Jerald Harris of Dixie State College of Utah and Matthew Lamanna of Carnegie Natural History Museum in Pittsburgh.

"Gansus is very close to a modern bird and helps fill in the big gap between clearly non-modern birds and the explosion of early birds that marked the Cretaceous period, the final era of the Dinosaur Age," said Peter Dodson, professor of anatomy at Penn's School of Veterinary Medicine and professor in Penn's Department of Earth and Environmental Sciences. "Gansus is the oldest example of the nearly modern birds that branched off of the trunk of the family tree that began with the famous proto-bird Archaeopteryx."

Gansus yumenensis takes its name from the Gansu region, where it was found, and the nearby city of Yumen. According to Dodson, Gansus is something of a lost species, originally described from a fossil leg found in 1983, but since largely ignored by science. The five specimens described by Dodson and his colleagues had many of the anatomical traits of modern birds, including feathers, bone structure and webbed feet, although every specimen lacked a skull.

"It appears that the early ancestors of modern birds lived lifestyles that today we would stereotype as being duck-like, heron-like, stork-like, loon-like, etc.," said Jerald Harris, director of paleontology at Dixie Sate College of Utah. "Gansus likely behaved much like its modern relatives, probably eating fish, insects and the occasional plan. We won't have a definitive dietary answer until we find a skull."

The skeletons, headless as they are, offer plenty of evidence for a life on the water. Its upper body structure offers evidence that Gansus could take flight from the water, like a modern duck, and the webbed feet and bony knees are clear signs that Gansus swam.

The famous proto-bird Archaeopteryx. (Image
copyright Joe Tucciarone and Jeff Poling)

"Webbed feet is an adaptation that has evolved repeatedly in widely separate groups of animals, such as sea turtles, whales and manatees, and would only hinder climbing or landing in trees," Harris said. "The big bony crest that sticks off the knee-end of their lower leg bones are similar to structures seen in loons and grebes. These crests anchor powerful muscles needed for diving under water and swimming."

According to Harris, these adaptations all demonstrate how the Gansus branch of the family tree, the structurally modern birds called ornithuromorphs, split from the enantiornitheans (or "opposite birds"). Enantiornitheans were among the feathered fossils found in northeastern China during the 1990s.

"The enantiornitheans had the best adaptations for perching, so they were able to dominate the ecological niche that we would associate with songbirds, cuckoos, woodpeckers or birds of prey," Harris said. "Gansus appears to have had adaptations for a lifestyle centered around water, based on things like the proportions of the leg and foot bones."

While the enantiornitheans are now long gone, their perching lifestyle has now been taken over by the descendents of birds like Gansus. What remains a mystery for now, according to the researchers, is how the amphibious lifestyle of birds like Gansus helped enable them to survive the cataclysmic end of the dinosaurs 65 million years ago.

University of Pennsylvania -

Vampire Bats Hear You Breathing!
BioMed Central News Release

June 16, 2006 - Vampire bats, the only mammals to feed exclusively on blood, including human blood, recognize their prey by the sound of its breathing.

In a study published today in the open access journal BMC Biology, vampire bats of the species Desmodus rotondus could recognise recorded human breathing sounds much better than human participants could.

Vampire bats feed on the same prey over several nights and the authors of the study propose that the bats use breathing sounds to identify their prey in the same way as humans use voice to recognise each other.

In a study conducted by Udo Groeger and Lutz Wiegrebe from the Ludwig-Maximilians-Universitaet in Munich, Germany, two vampire bats were taught to associate recordings of different humans breathing with different cattle blood dispensers, providing food rewards. They were then played short clips of people breathing and had to associate them with the correct individual by going to the correct dispenser.

Four human participants were asked to associate the same short clips with the correct individual.

The vampire bats were able to spontaneously associate the clips with the particular individuals, regardless of whether the individual was recorded breathing at rest or breathing while under physical strain. The human participants were also able to recognise some clips, but they were unable to recognise the clips of breathing recorded under physical strain.

BioMed Central -

Neptune's Trojans!

The planet Neptune (NASA)
Carnegie Institution News Release

June 15, 2006 Washington DC – Three new objects locked into roughly the same orbit as Neptune--called "Trojan" asteroids--have been found by researchers from the Carnegie Institution's Department of Terrestrial Magnetism (DTM) and the Gemini Observatory in Hilo, Hawaii.

The discovery offers evidence that Neptune, much like its big cousin Jupiter, hosts thick clouds of Trojans in its orbit, and that these asteroids probably share a common source. It also brings the total of known Neptune Trojans to four.

"It is exciting to have quadrupled the known population of Neptune Trojans," said Carnegie Hubble Fellow Scott Sheppard, lead author of the study, which appears in the June 15 online issue of Science Express. "In the process, we have learned a lot both about how these asteroids become locked into their stable orbits, as well as what they might be made of, which makes the discovery especially rewarding."

The recently discovered Neptune Trojans are only the fourth stable group of asteroids observed around the Sun. The others are the Kuiper Belt just beyond Neptune, the Jupiter Trojans, and the main asteroid belt between Mars and Jupiter.

Evidence suggests that the Neptune Trojans are more numerous than either the main asteroid belt or the Jupiter Trojans, but they are hard to observe because they are so far away from the Sun. Astronomers therefore require the largest telescopes in the world equipped with sensitive digital cameras to detect them.

Trojan asteroids cluster around one of two points that lead or trail the planet by about 60 degrees in its orbit, known as Lagrangian points. In these areas, the gravitational pull of the planet and the Sun combine to lock the asteroids into stable orbits synchronized with the planet.

German Astronomer Max Wolf identified the first Jupiter Trojan in 1906, and since then, more than 1800 such asteroids have been identified marching along that planet's orbit. Because Trojan asteroids share a planet's orbit, they can help astronomers understand how planets form, and how the solar system evolved.

Researchers theorized that Trojans might also flank other planets, but evidence for this has surfaced only recently. In 2001, the first Neptune Trojan was spotted in the planet's leading Lagrangian point.

In this schematic of the outer solar system, "Trojan" asteroids
can be seen sharing the orbits of Jupiter and Neptune. At either
of two points 60 degrees away from each planet, the
gravitational forces of the planet and the Sun combine to lock
the asteroids into a stable, synchronized orbit. Three new Trojans
have been found in the region ahead of Neptune, bringing the
total to four; the discovery suggests that Neptune hosts clouds of
Trojans that are more dense and populous than those in Jupiter's
orbit. (Image: Scott Sheppard)

In 2004, Sheppard and Chadwick Trujillo of the Gemini Observatory, who is also an author on the current study, found the second Neptune Trojan using Carnegie's Magellan-Baade 6.5 meter telescope in Las Campanas, Chile. They found two more in 2005, bringing the total to four, and observed them again using the 8.2 meter Gemini Telescope in Hawaii in order to accurately determine their orbits. All four of the known Neptune Trojans reside in the planet's leading Lagrangian point.

One of the new Trojans has an orbit that is more steeply tilted to the plane of the solar system than the other three. Although only this one has such a steep orbit, the methods used to observe the asteroids are not sensitive to objects so far out of tilt with the rest of the solar system.

The very existence of this Trojan suggests that there are many more like it, and that Neptune's Trojans as a whole occupy thick clouds with complex, interlaced orbits.

"We were really surprised to find a Neptune Trojan with such a large orbital inclination," Trujillo said. "The discovery of the one tilted Neptune Trojan implies that there may be many more far from the solar system plane than near the plane, and that the Trojans are really a "cloud" or "swarm" of objects co-orbiting with Neptune."

A large population of high-inclination Neptune Trojans would rule out the possibility that they are left over from early in the solar system's history, since unaltered primordial asteroid groups should be closely aligned with the plane of the solar system.

These clouds probably formed much like Jupiter's Trojan clouds did: once the giant planets settled into their paths around the Sun, any asteroid that happened to be in the Trojan region "froze" into its orbit.

Sheppard and Trujillo also compared, for the first time, the colors of all four known Neptune Trojans. They are all about the same shade of pale red, suggesting that they share a similar origin and history. Though it is hard to tell for sure with only four on the books, the researchers believe that the Neptune Trojans might share a common origin with the Jupiter Trojans and outer irregular satellites of the giant planets.

These objects might be the last remnants of the countless small bodies that formed in the giant planet region, most of which eventually became part of the planets or were tossed out of the solar system.

Carnegie Institution -

News You Already Knew Was True Department:
Erotic Images Elicit Strong Response from Brain!

A brain map illustrates different
levels of activity as brain circuits
process erotic and neutral visual
materials 185 milliseconds after
a picture is viewed. Red zones
represent the highest activity
levels in the brain regions
processing erotic pictures. (WUSTL)
Washington University School of Medicine News Release
By Jim Dryden

June 8, 2006 - A new study suggests the brain is quickly turned on and "tuned in" when a person views erotic images.

Researchers at Washington University School of Medicine in St. Louis measured brainwave activity of 264 women as they viewed a series of 55 color slides that contained various scenes from water skiers to snarling dogs to partially-clad couples in sensual poses.

What they found may seem like a "no brainer." When study volunteers viewed erotic pictures, their brains produced electrical responses that were stronger than those elicited by other material that was viewed, no matter how pleasant or disturbing the other material may have been. This difference in brainwave response emerged very quickly, suggesting that different neural circuits may be involved in the processing of erotic images.

"That surprised us," says first author Andrey P. Anokhin, Ph.D., research assistant professor of psychiatry. "We believed both pleasant and disturbing images would evoke a rapid response, but erotic scenes always elicited the strongest response."

As subjects looked at the slides, electrodes on their scalps measured changes in the brain's electrical activity called event-related potentials (ERPs). The researchers learned that regardless of a picture's content, the brain acts very quickly to classify the visual image.

The ERPs begin firing in the brain's cortex long before a person is conscious of whether they are seeing a picture that is pleasant, unpleasant or neutral.

Erotic is in the eye of the beholder:
does this turn you on?

But when the picture is erotic, ERPs begin firing within 160 milliseconds, about 20 percent faster than occurred with any of the other pictures. Soon after, the ERPs begin to diverge, with processing taking place in different brain structures for erotic pictures than those that process the other images.

"When we present a stimulus to a subject — for example, when a picture appears on a screen — it changes ongoing brain activity in certain ways, and we can detect those changes," Anokhin says.

Pictures appeared on a screen at 12 to 18 second intervals, and each picture remained on the screen for about 6 seconds. The subjects were instructed to do nothing other than look at the pictures.

How about this?

A great deal of past research has suggested that men are more visual creatures than women and get more aroused by erotic images than women. Anokhin says the fact that the women's brains in this study exhibited such a quick response to erotic pictures suggests that, perhaps for evolutionary reasons, our brains are programmed to preferentially respond to erotic material.

"Usually men subjectively rate erotic material much higher than women," he says. "So based on those data we would expect lower responses in women, but that was not the case. Women have responses as strong as those seen in men."

Because the electroencephalogram (EEG) technology cannot pinpoint specific brain structures involved in this visual processing, Anokhin says it's not clear exactly which circuits are reacting to these visual scenes. Recent studies in primates recorded the electrical activity of single neural cells within the brain and have shown that the frontal cortex contains neurons that can discriminate between different categories of visual objects such as dogs versus cats.

Betty Page, maybe?

Whether or not the human prefrontal cortex contains special neurons that are "tuned" for sex remains a subject for future studies.

"The newer and more advanced technologies such as MRI and PET provide much better spatial resolution," he says. "Those methods can better localize areas of brain activity, but ERPs have a much better temporal resolution. The EEG can record neuronal activity in real time. When measuring activity in milliseconds, any delay is undesirable."

Most of Anokhin's research is centered on the genetic and neurobiological bases of behavioral traits that might be associated with increased vulnerability to alcoholism and addictive disorders. He believes this study could contribute to that work by detecting differences between responses to images with different emotional significance.

Because many psychiatric disorders also are associated with poor processing of signals associated with reward and pleasure, as well as sexual disturbances, he believes the way the brain processes emotional pictures, including erotic materials, might help scientists better understand some forms of mental illness.

Washington University School of Medicine -

Brain-Computer Interface!
Elhuyar Fundazioa News Release

June 14, 2006 - Controlling a computer just by thought is the aim of cerebral interfaces. The engineer from Pamplona, Carmen Vidaurre Arbizu, has designed a totally adaptive interface that improves the performance of currently existing devices in, reducing the time needed to become skilled in their operation and enhance the control that users have over the interface.

Moreover, according to Ms Vidaurre, the majority of the population is capable of using it. The results appear in the PhD thesis, Online Adaptive Classification for Brain-Computer Interfaces, defended recently at the Public University of Navarre.

Cerebral interface

A cerebral interface or brain-computer interface (BCI) allows people with communication problems to relate to their surroundings using a computer and the electrophysiological signals from the brain.

The actual interface with which Carmen Vidaurre has worked with is based on electroencephalograms (EEG) of the individual, although there are others that use signals recorded from electrodes fitted directly into the brain.

The user and the interface are highly interdependent “systems” that, up to recently, adapted to each other independently. In the past, when a non-experienced individual started to use a BCI, the systems were unable to supply feedback, i.e. the individual was unable to see the results of their brain patterns on the screen.

The majority of the population are capable
of learning to control an adaptive BCI

With those outdated systems and, after a number of prior, data-collecting sessions, feedback was included and, in this way, the subjects started to adapt themselves to the computer, using the interface response to the patterns extracted from the signals. However, few users could use these interfaces because the patterns generated during the trial sessions had to be greatly similar to those sessions with feedback.

One of the biggest problems found by other users and researchers into these “static” systems was that the patterns extracted from the signals recorded in the trial sessions were quite different from those signals recorded in the presence of feedback. For example, the visual input was different between both types of sessions and this difference significantly changes brain activity in specific areas thereof.

For inexpert users it is very difficult to adapt to the traditional interface because they are unable to generate stationary patterns in time, probably due to their inexperience. They find it very complicated to reproduce mental states sufficiently similar to be correctly classified.

Pioneering research

This is why, this PhD has designed, in a pioneering way, two in-line adaptive classifications, within a completely adaptive interface and capable of supplying feedback to inexpert individuals in the first stages of its use. With this system, the interface and the individual adjust to each other, one learning from the other in a reciprocal manner. In this way it has been possible to eliminate the initial trial sessions without feedback, thus diminishing the total skills acquisition time and the individuals are able to find an operating strategy directly with feedback.

Moreover, the experiments carried out with individuals without prior experience, have demonstrated that the majority of the population are capable of learning to control an adaptive BCI. Specifically, in the trials undertaken with 30 persons in Austria and Pamplona, it was found that 20 had been able to control the interface “very well” within 4 hours.

No mouse - but probably a silly hat

Four modules

The interface is basically made up of four modules that take charge of, respectively, the acquisition and pre-processing of the signal; the extraction of its characteristics; the classification of the signal in the various patterns the interface possesses and, finally, the feedback, the stage in which it is tested whether the action has been the expected one or not.

This research has mainly focused on the classification module, dealing with identifying the type of signal that the subject is sending. In an interface that has, for example, two patterns (imagination of the movement of the left hand and of the movement of the right hand), the classification module tries to decide to which pattern the current signal belongs.

Universidad Pública de Navarra -

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