|Polar Bears at Risk! |
Dino Ducks! Vampire Bats!
Neptune's Trojans! Erotic Images!
|Polar Bears at Risk!|
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:
"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."
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."
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.
"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."
|Vampire Bats Hear You Breathing!|
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.
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 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.
|News You Already Knew Was True Department: |
Erotic Images Elicit Strong Response from Brain!
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.
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.
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.
Whether or not the human prefrontal cortex contains special neurons that are "tuned" for sex remains a subject for future studies.
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.
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.
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.
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.