Planets Forming In Pleiades Star Cluster, Astronomers Report

Color composite image of the Pleiades star cluster produced by Inseok Song of the Spitzer Science Center, using montage software developed by IPAC/California Institute of Technology. An artist's rendering of a collision in the Pleiades (inset), by Lynette R. Cook, for Gemini Observatory. (Credit: Image courtesy of University of California, Los Angeles)

ScienceDaily (Nov. 15, 2007) — Rocky terrestrial planets, perhaps like Earth, Mars or Venus, appear to be forming or to have recently formed around a star in the Pleiades ("seven sisters") star cluster, the result of "monster collisions" of planets or planetary embryos.

Astronomers using the Gemini Observatory in Hawaii and the Spitzer Space Telescope report their findings in an upcoming issue of the Astrophysical Journal, the premier journal in astronomy.

"This is the first clear evidence for planet formation in the Pleiades, and the results we are presenting may well be the first observational evidence that terrestrial planets like those in our solar system are quite common," said Joseph Rhee, a UCLA postdoctoral scholar in astronomy and lead author of the research.

The Pleiades star cluster, in the constellation Taurus, is well-known in many cultures. It is named for the seven daughters of Atlas and Pleione, who were placed by Zeus among the stars in Greek mythology and is cited in the Bible — "Can you bind the beautiful Pleiades? Can you loose the cords of Orion?" (Job 38:31). The automaker Subaru's name is the Japanese word for the Pleiades, Rhee said.

The Pleiades is probably the best known star cluster and the most striking to the naked eye. "You've seen it many times, and it's now easily visible in the evening sky," said research co-author Benjamin Zuckerman, UCLA professor of physics and astronomy.

Although referred to as the "seven sisters," "the cluster actually contains some 1,400 stars," said co-author Inseok Song, a staff scientist at NASA's Spitzer Science Center at the California Institute of Technology and a former astronomer with the Gemini Observatory.

Located about 400 light-years away, the Pleiades is one of the closest star clusters to Earth. One of the cluster's stars, known as HD 23514, which has a mass and luminosity a bit greater than those of the sun, is surrounded by an extraordinary number of hot dust particles — "hundreds of thousands of times as much dust as around our sun," Zuckerman said. "The dust must be the debris from a monster collision, a cosmic catastrophe."

The astronomers analyzed emissions from countless microscopic dust particles and concluded that the most likely explanation is that the particles are debris from the violent collision of planets or planetary embryos.

Song calls the dust particles the "building blocks of planets," which can accumulate into comets and small asteroid-size bodies and then clump together to form planetary embryos, eventually becoming full-fledged planets.

"In the process of creating rocky, terrestrial planets, some objects collide and grow into planets, while others shatter into dust," Song said. "We are seeing that dust."

HD 23514 is the second star around which Song and Zuckerman recently have found evidence of terrestrial planet formation. They and their colleagues reported in the journal Nature in July 2005 that a sun-like star known as BD +20 307, located 300 light-years from Earth in the constellation Aries, is surrounded by one million times more dust than is orbiting our sun.

In an effort to uncover comparably dusty stars after their 2005 research, Rhee, Song and Zuckerman began looking through thousands of publicly accessible, deep-infrared images obtained by the Spitzer Space Telescope and soon discovered HD 23514. The astronomers then used the Gemini North telescope, located on Hawaii's dormant volcano Mauna Kea, to measure the heat radiation coming from the dust; the heat emerges at infrared wavelengths, just as the heat from our bodies does, Song said.

"The Gemini and Spitzer data were crucial in identifying and establishing the amount and location of dust around the star," Song said.

While our sun is 4.5 billion years old, the Pleiades Aries stars are "adolescents," about 100 million and 400 million years old, respectively, Rhee said. Based on the age of the two stars and the dynamics of the orbiting dust particles, the astronomers deduce that most adolescent sun-like stars are likely to be building terrestrial-like planets through recurring violent collisions of massive objects. The cosmic debris from only a small percentage of such collisions can be seen at any one time — currently, only HD 23514 and BD +20 307 have visible debris.

"Our observations indicate that terrestrial planets similar to those in our solar system are probably quite common," Zuckerman said.

The astronomers calculate that terrestrial planets or planetary embryos in the Pleiades collided within the last few hundred thousand years — or perhaps much more recently — but they cannot rule out the possibility that multiple, somewhat smaller collisions occurred.

Many astronomers believe our moon was formed through the collision of two planetary embryos — the young Earth and a body about the size of Mars. That crash created tremendous debris, some of which condensed to form the moon and some of which went into orbit around the young sun, Zuckerman said.

By contrast, the collision of an asteroid with Earth 65 million years ago, the most favored explanation for the final demise of the dinosaurs, was a mere pipsqueak, he said.

"Collisions between comets or asteroids wouldn't produce anywhere near the amount of dust we are seeing," Song said.

HD 23514 and BD +20 307 are by far the dustiest not-so-young stars in the sky. "Nothing else is even close," Song said.

Very young stars — those 10 million years old or younger — may have a similar amount of dust around them as a result of the star-formation process. However, by the time a star is 100 million years old, this "primordial" dust has dissipated because the dust particles get blown away or dragged onto the star, or the particles clump together to form much larger objects.

"Unusually massive amounts of dust, as seen at the Pleiades and Aries stars, cannot be primordial but rather must be the second-generation debris generated by collisions of large objects," Song said.

The Pleiades have been considered important by many cultures throughout history.

"To the Vikings, the Pleiades was Freyja's hens," Rhee said. In Bronze Age Europe, the Celts and others associated the Pleiades with mourning and funerals because the cluster rose in the eastern night sky between the autumnal equinox and the winter solstice, which was a festival devoted to the remembrance of the dead. The ancient Aztecs of Mexico and Central America based their calendar on the Pleiades.

The astronomers' research results are based on mid- and far- infrared observations made with the Gemini 8-meter Frederick C. Gillett Telescope at Gemini North and the space-based infrared observatories Infrared Astronomical Satellite (IRAS), Infrared Space Observatory (ISO) and NASA's Spitzer Space Telescope.

Adapted from materials provided by University of California, Los Angeles.

How Violent Video Games Are Exemplary Aggression Teachers

Students who played multiple violent video games actually learned through those games to produce greater hostile actions and aggressive behaviors over a span of six months, researchers have found. (Credit: iStockphoto/Quavondo Nguyen)


ScienceDaily (Nov. 14, 2007) — Like other fathers and sons, Douglas Gentile and his father have spent many hours arguing about video games. What makes them different is that Douglas, an Iowa State University assistant professor of psychology, is one of the country's top researchers on the effects of media on children. His father, J. Ronald Gentile, is a leading researcher on effective teaching and a distinguished teaching professor emeritus of educational psychology at the University of Buffalo, State University of New York.

Through their discussions, they realized that video games use the same techniques that really great teachers use.

"That realization prompted us to ask the question, 'Should we therefore be surprised that violent video games could teach aggression to players?'" said Doug Gentile, who is also director of research for the National Institute on Media and the Family.

Violent video games teach aggression

The Gentiles decided to test that hypothesis. Through a study of nearly 2,500 youths, they found that video games are indeed effective teaching tools. Students who played multiple violent video games actually learned through those games to produce greater hostile actions and aggressive behaviors over a span of six months.

"We know a lot about how to be an effective teacher, and we know a lot about how to use technology to teach," said lead author Douglas Gentile. "Video games use many of these techniques and are highly effective teachers. So we shouldn't be surprised that violent video games can teach aggression."

The paper presents conceptual and empirical analyses of several of the "best practices" of learning and instruction, and demonstrates how violent video games use those practices effectively to teach aggression. It documents how violent video games motivate learners to persevere in learning and mastering skills to navigate through complex problems and changing environments -- just like good teachers do.

The study describes seven parallels between video games and effective teachers, including the ability to adapt to the level of each individual learner -- requiring practice distributed across time -- and teaching for transfer to real-world situations.

Studying nearly 2,500 youths

To test their hypothesis, the Gentiles studied three groups of youths -- 430 third through fifth-graders; 607 eighth and ninth graders; and 1,441 older adolescents with an average age of 19. Elementary and middle school children were recruited from nine Minnesota schools, and older adolescents from Iowa State University.

In the longitudinal elementary school sample, students, their peers, and their teachers completed surveys at two points during the school year. The surveys assessed the subject's aggressive thoughts and self-reported fights, and their media habits -- including violent video game exposure. Teachers and peers were also asked to rate the participants' aggressive behavior.

Controlling for age, race, sex, total amount of time spent playing all video games, and prior aggressive behaviors, the research found that the amount of rated violence in the games played predicted increased aggression. Among elementary students, playing multiple violent video games increased their risk of being highly aggressive -- as rated by peers and teachers -- by 73 percent, when compared to those who played a mix of violent and non-violent games, and by 263 percent compared to those who played only non-violent games.

"Because we had longitudinal data, we were able to show that students who play multiple violent games actually changed to have a greater hostile attribution bias, which also increased their aggressive behaviors over prior levels," the researchers wrote.

And because learning occurs from video games, regardless of whether the effects are intentional or unintentional, the Gentiles added that this "should make us more thoughtful about designing games and choosing games for children and adolescents to play."

But this study is not all bad news for video game technology. Because video games were found to be such effective teaching tools, the Gentiles propose greater educational use of today's smarter technology found in those games -- technology that "thinks" along with students, adapting instruction to each student's current skills, strategies or mistakes.

While some schools are already incorporating this type of educational programming, the researchers report that it's not widely used. The authors urge educators not to wait for more advancement before using such technology with students in the classroom.

They co-authored a paper on their research titled "Violent Video Games as Exemplary Teachers: A Conceptual Analysis," which will be published in an upcoming issue of the Journal of Youth and Adolescence. It is already available online to the journal's subscribers.

Adapted from materials provided by Iowa State University.

What Determines Sky's Colors At Sunrise And Sunset?

Molecules and small particles in the atmosphere change the direction of light rays, causing them to scatter and resulting in colorful sunsets. (Credit: iStockphoto/Michael Valdez)









ScienceDaily (Nov. 15, 2007) — The colors of the sunset result from a phenomenon called scattering, says Steven Ackerman, professor of meteorology at UW-Madison. Molecules and small particles in the atmosphere change the direction of light rays, causing them to scatter.

Scattering affects the color of light coming from the sky, but the details are determined by the wavelength of the light and the size of the particle. The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum. This is why blue and violet light reaches our eyes from all directions on a clear day. But because we can't see violet very well, the sky appears blue.

Scattering also explains the colors of the sunrise and sunset, Ackerman says.

“Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes. If the path is long enough, all of the blue and violet light scatters out of your line of sight. The other colors continue on their way to your eyes. This is why sunsets are often yellow, orange, and red.”

And because red has the longest wavelength of any visible light, the sun is red when it’s on the horizon, where its extremely long path through the atmosphere blocks all other colors.

Adapted from materials provided by University of Wisconsin - Madison.

Curry-derived Molecules Might Be Too Spicy For Colorectal Cancers

Fresh turmeric roots. Curcumin, the yellowish component of turmeric that gives curry its flavor, has long been noted for its potential anti-cancer properties. (Credit: iStockphoto/Kelly Cline)


ScienceDaily (Nov. 6, 2007) — Curcumin, the yellowish component of turmeric that gives curry its flavor, has long been noted for its potential anti-cancer properties. Researchers from Tohoku University in Sendai, Japan, report on an apparent improvement upon nature: two molecular analogues of curcumin that demonstrate even greater tumor suppressive properties. The team presented their findings from the first test of these molecules in a mouse model of colorectal cancer November 5 at the American Association for Cancer Research Centennial Conference on Translational Cancer Medicine.

According to Tohoku University researcher Hiroyuki Shibata, M.D., curcumin is one of the most widely studied plant-based chemicals with anti-cancer properties. Research has associated curcumin with several distinct actions, including the suppression of genes that promote cell growth (for example, the destruction of the pro-cancerous protein alpha-catenin), and induction of programmed cell death (apoptosis) in colorectal cancer.

Unfortunately, natural curcumin has what researchers term "low bioavailability" -- the molecule quickly loses its anti-cancer attributes when ingested, Shibata says. With the aim of improving the therapeutic potential of curcumin, Shibata and his colleagues synthesized and tested 90 variations of the molecule's structure. Two, GO-Y030 and GO-Y031, proved to be more potent and bioavailable, than natural curcumin.

"Our new analogues have enhanced growth suppressive abilities against colorectal cancer cell lines, up to 30 times greater than natural curcumin," said Shibata, associate professor in the Department of Clinical Oncology at the Institute of Development, Aging and Cancer at Tohoku University. "In a mouse model for colorectal cancer, mice fed with five milligrams of GO-Y030 or GO-Y031 fared 42 and 51 percent better, respectively, than did mice in the control group."

In 2006, the researchers published basic safety and structural data for GO-Y030 and GO-Y031 in Molecular Cancer Therapeutics, a publication of the American Association for Cancer Research, and they continue to study the mechanisms behind the molecules' apparent potencies. In its natural form, the curcumin molecule is composed of two ring structures linked by a chain of seven carbon atoms. The active ring structures of GO-Y030 and GO-Y031, however, are linked by a shorter, five-carbon chain, which Shibata says might -- for reasons still under investigation --account for their enhanced potency.

Like curcumin, the researchers believe the new analogues have clinical potential that extends beyond colorectal cancer. "In addition to colorectal cancer, the â catenin-degrading abilities of these molecules could apply to other forms of cancer, such as gastric cancer," said Shibata. "Like curcumin, these analogues also down-regulate a number of gene products, such as NF-kappa B, ErbB2, K-ras, that are also implicated in breast, pancreas and lung cancers among other diseases."

"In addition to their chemopreventative abilities, these molecules might also form the basis of a potent chemotherapy, either alone or in combination with other modes of therapy," said Shibata.

According to Shibata, the next step for the researchers is to further examine the drug delivery mechanisms, toxicology and pharmacokinetics of these analogues, before extending the research to clinical trials. Their studies were funded by the Japanese Society for the Promotion of Science and the Miyagi Health Service Association.

Adapted from materials provided by American Association for Cancer Research.

Climate Change Threatens Drinking Water, As Rising Sea Penetrates Coastal Aquifers

ScienceDaily (Nov. 7, 2007) — As sea levels rise, coastal communities could lose up to 50 percent more of their fresh water supplies than previously thought, according to a new study from Ohio State University.

Galveston Beach, Texas, Gulf of Mexico. In the United States, lands along the East Coast and the Gulf of Mexico -- especially Florida and Louisiana -- are most likely to be flooded as sea levels rise. (Credit: iStockphoto/Sergey Kubyshin)

Hydrologists here have simulated how saltwater will intrude into fresh water aquifers, given the sea level rise predicted by the Intergovernmental Panel on Climate Change (IPCC). The IPCC has concluded that within the next 100 years, sea level could rise as much as 23 inches, flooding coasts worldwide.

Scientists previously assumed that, as saltwater moved inland, it would penetrate underground only as far as it did above ground.

But this new research shows that when saltwater and fresh water meet, they mix in complex ways, depending on the texture of the sand along the coastline. In some cases, a zone of mixed, or brackish, water can extend 50 percent further inland underground than it does above ground.

Like saltwater, brackish water is not safe to drink because it causes dehydration. Water that contains less than 250 milligrams of salt per liter is considered fresh water and safe to drink.

Motomu Ibaraki, associate professor of earth sciences at Ohio State, led the study. Graduate student Jun Mizuno presented the results October 30, 2007, at the Geological Society of America meeting in Denver.

“Almost 40 percent of the world population lives in coastal areas, less than 60 kilometers from the shoreline,” Mizuno said. “These regions may face loss of freshwater resources more than we originally thought.”

“Most people are probably aware of the damage that rising sea levels can do above ground, but not underground, which is where the fresh water is,” Ibaraki said. “Climate change is already diminishing fresh water resources, with changes in precipitation patterns and the melting of glaciers. With this work, we are pointing out another way that climate change can potentially reduce available drinking water. The coastlines that are vulnerable include some of the most densely populated regions of the world.”

In the United States, lands along the East Coast and the Gulf of Mexico -- especially Florida and Louisiana -- are most likely to be flooded as sea levels rise. Vulnerable areas worldwide include Southeast Asia, the Middle East, and northern Europe.

“Almost 40 percent of the world population lives in coastal areas, less than 60 kilometers from the shoreline,” Mizuno said. “These regions may face loss of freshwater resources more than we originally thought.”

Scientists have used the IPCC reports to draw maps of how the world's coastlines will change as waters rise, and they have produced some of the most striking images of the potential consequences of climate change.

Ibaraki said that he would like to create similar maps that show how the water supply could be affected.

That's not an easy task, since scientists don't know exactly where all of the world's fresh water is located, or how much is there. Nor do they know the details of the subterranean structure in many places.

One finding of this study is that saltwater will penetrate further into areas that have a complex underground structure.

Typically, coastlines are made of different sandy layers that have built up over time, Ibaraki explained. Some layers may contain coarse sand and others fine sand. Fine sand tends to block more water, while coarse sand lets more flow through.

The researchers simulated coastlines made entirely of coarse or fine sand, and different textures in between. They also simulated more realistic, layered underground structures.

The simulation showed that, the more layers a coastline has, the more the saltwater and fresh water mix. The mixing causes convection -- similar to the currents that stir water in the open sea. Between the incoming saltwater and the inland fresh water, a pool of brackish water forms.

Further sea level rise increases the mixing even more.

Depending on how these two factors interact, underground brackish water can extend 10 to 50 percent further inland than the saltwater on the surface.

According to the United States Geological Survey, about half the country gets its drinking water from groundwater. Fresh water is also used nationwide for irrigating crops.

“In order to obtain cheap water for everybody, we need to use groundwater, river water, or lake water,” Ibaraki said. “But all those waters are disappearing due to several factors --including an increase in demand and climate change.”

One way to create more fresh water is to desalinate saltwater, but that's expensive to do, he said.

“To desalinate, we need energy, so our water problem would become an energy problem in the future.”

Adapted from materials provided by Ohio State University.

Cirrus Disappearance: Warming Might Thin Heat-trapping Clouds

Cirrus clouds. (Credit: NOAA Central Library, Photo by Albert E. Theberge Junior)

ScienceDaily (Nov. 5, 2007) — The widely accepted (albeit unproven) theory that manmade global warming will accelerate itself by creating more heat-trapping clouds is challenged this month in new research from The University of Alabama in Huntsville.

Instead of creating more clouds, individual tropical warming cycles that served as proxies for global warming saw a decrease in the coverage of heat-trapping cirrus clouds, says Dr. Roy Spencer, a principal research scientist in UAHuntsville's Earth System Science Center.

That was not what he expected to find.

"All leading climate models forecast that as the atmosphere warms there should be an increase in high altitude cirrus clouds, which would amplify any warming caused by manmade greenhouse gases," he said. "That amplification is a positive feedback. What we found in month-to-month fluctuations of the tropical climate system was a strongly negative feedback. As the tropical atmosphere warms, cirrus clouds decrease. That allows more infrared heat to escape from the atmosphere to outer space."

"While low clouds have a predominantly cooling effect due to their shading of sunlight, most cirrus clouds have a net warming effect on the Earth," Spencer said. With high altitude ice clouds their infrared heat trapping exceeds their solar shading effect.

In the tropics most cirrus-type clouds flow out of the upper reaches of thunderstorm clouds. As the Earth's surface warms - due to either manmade greenhouse gases or natural fluctuations in the climate system - more water evaporates from the surface. Since more evaporation leads to more precipitation, most climate researchers expected increased cirrus cloudiness to follow warming.

"To give an idea of how strong this enhanced cooling mechanism is, if it was operating on global warming, it would reduce estimates of future warming by over 75 percent," Spencer said. "The big question that no one can answer right now is whether this enhanced cooling mechanism applies to global warming."

The only way to see how these new findings impact global warming forecasts is to include them in computerized climate models.

"The role of clouds in global warming is widely agreed to be pretty uncertain," Spencer said. "Right now, all climate models predict that clouds will amplify warming. I'm betting that if the climate models' 'clouds' were made to behave the way we see these clouds behave in nature, it would substantially reduce the amount of climate change the models predict for the coming decades."

The UAHuntsville research team used 30- to 60-day tropical temperature fluctuations - known as "intraseasonal oscillations" - as proxies for global warming.

"Fifteen years ago, when we first started monitoring global temperatures with satellites, we noticed these big temperature fluctuations in the tropics," Spencer said. "What amounts to a decade of global warming routinely occurs in just a few weeks in the tropical atmosphere. Then, as if by flipping a switch, the rapid warming is replaced by strong cooling. It now looks like the change in cirrus cloud coverage is the major reason for this switch from warming to cooling."

The team analyzed six years of data from four instruments aboard three NASA and NOAA satellites. The researchers tracked precipitation amounts, air and sea surface temperatures, high and low altitude cloud cover, reflected sunlight, and infrared energy escaping out to space.

When they tracked the daily evolution of a composite of fifteen of the strongest intraseasonal oscillations they found that although rainfall and air temperatures would be rising, the amount of infrared energy being trapped by the cloudy areas would start to decrease rapidly as the air warmed. This unexpected behavior was traced to the decrease in cirrus cloud cover.

The new results raise questions about some current theories regarding precipitation, clouds and the efficiency with which weather systems convert water vapor into rainfall. These are significant issues in the global warming debate.

"Global warming theory says warming will generally be accompanied by more rainfall," Spencer said. "Everyone just assumed that more rainfall means more high altitude clouds. That would be your first guess and, since we didn't have any data to suggest otherwise ..."

There are significant gaps in the scientific understanding of precipitation systems and their interactions with the climate, he said. "At least 80 percent of the Earth's natural greenhouse effect is due to water vapor and clouds, and those are largely under the control of precipitation systems.

"Until we understand how precipitation systems change with warming, I don't believe we can know how much of our current warming is manmade. Without that knowledge, we can't predict future climate change with any degree of certainty."

Spencer and his colleagues expect these new findings to be controversial.

"I know some climate modelers will say that these results are interesting but that they probably don't apply to long-term global warming," he said. "But this represents a fundamental natural cooling process in the atmosphere. Let's see if climate models can get this part right before we rely on their long term projections."

The results of this research were published recently in the American Geophysical Union's "Geophysical Research Letters" on-line edition. The paper was co-authored by UAHuntsville's Dr. John R. Christy and Dr. W. Danny Braswell, and Dr. Justin Hnilo of Lawrence Livermore National Laboratory, Livermore, CA.

Adapted from materials provided by University Of Alabama In Huntsville.

Tutankhamen's 'beautiful' face revealed

The true face of ancient Egypt's boy king Tutankhamen was revealed to the public for the first time on Sunday since he died in mysterious circumstances more than 3000 years ago.

The mummy was moved from its ornate sarcophagus in the tomb where its 1922 discovery caused an international sensation to a nearby climate-controlled case where experts say it will be better preserved.

Tutankhamen's body is entirely wrapped in strips of white linen, except for his face which, until now, had been seen by only a handful of experts.

Made pharaoh at the age of nine, Tutankhamen became famous with the discovery of his tomb and the treasures within by Briton Howard Carter.

His iconic solid gold burial mask weighs 11 kilograms, encrusted with lapis lazuli and other semi-precious stones.

The mummy had to be reconstructed after Carter cut it into 18 pieces to gain access to amulets and other jewellery, Mustafa Wazery, director of the Valley of the Kings, said.

"What you will see is a beautiful face," Wazery told journalists ahead of the mummy's displacement. "He's a good-looking boy, with a nice smile and buck teeth."

Every day hundreds of visitors file through his tomb in the Valley of the Kings on the west bank of the Nile in the southern Egyptian city of Luxor, bringing with them into the royal tomb bacteria, humidity and other pollutants.

"The mummy risked being reduced to dust because of the rising levels of humidity due to the visitors," Egypt's antiquities chief Zahi Hawass said.

"The mummy was already damaged by Howard Carter, who used sharp tools to remove the golden mask," Culture Minister Faruq Hosni said.

He said Carter damaged the mummy by "exposing it to burning sunshine for many hours" in the desert landscape.

A silicone representation of the face of the pharaoh, who died about 3300 years ago at the age of just 19, was reconstructed in 2005 using images collected through CAT scans of his mummy.

Egyptian, Swiss and Italian experts have deduced Tutankhamen died after an injury to his left leg led to rapid gangrene, rejecting a previously popular theory that the king had been killed by a blow to the neck.

When the tomb was discovered, the pharaoh's embalmed body was encased in three sarcophagi, one of which was made from solid gold.

Tutankhamen, the 12th pharaoh of the 18th dynasty, reigned for 10 years. Theories that he was assassinated stemmed from the fact that he was the last ruler of his dynasty.

The pharaoh Akhenaton the Heretic was thought to have fathered Tutankhamen, but the identity of his mother is not known.

The high priest Ay succeeded Tutankhamen for four years - also marrying his widow Ankhesenpamon - and he was followed by the military leader Horemheb, who ruled for 26 years until he ceded power to Ramses, founder of the 19th dynasty.

Courtesy: smh.com.au

Radio Waves Fire Up Nanotubes Embedded In Tumors, Destroying Liver Cancer

ScienceDaily (Nov. 3, 2007) — Cancer cells treated with carbon nanotubes can be destroyed by non-invasive radio waves that heat up the nanotubes while sparing untreated tissue, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center and Rice University has shown in preclinical experiments.
Researchers show that the technique completely destroyed liver cancer tumors in rabbits. There were no side effects noted. However, some healthy liver tissue within 2-5 millimeters of the tumors sustained heat damage due to nanotube leakage from the tumor.

"These are promising, even exciting, preclinical results in this liver cancer model," says senior author Steven Curley, M.D., professor in M. D. Anderson's Department of Surgical Oncology. "Our next step is to look at ways to more precisely target the nanotubes so they attach to, and are taken up by, cancer cells while avoiding normal tissue."

Targeting the nanotubes solely to cancer cells is the major challenge in advancing the therapy, Curley says. Research is under way to bind the nanotubes to antibodies, peptides or other agents that in turn target molecules expressed on cancer cells. To complicate matters, most such molecules also are expressed in normal tissue.

Curley estimates that a clinical trial is at least three to four years away.

Curley conducted the research at M. D. Anderson in collaboration with nanotechnology experts at Rice University and with Erie, Pennsylvania, entrepreneur John Kanzius of ThermMed LLC, who invented the experimental radiofrequency generator used in the experiments. Kanzius is a cancer survivor and former radio station owner whose insights into the potential of targeted radio waves inspired this line of research.

At Rice, the work was begun by Nobel laureate Richard Smalley, several months before his untimely death from cancer in October 2005. Smalley was the founder of Rice's Carbon Nanotechnology Laboratory and one of the world's foremost experts on carbon nanotubes. He shared the Nobel Prize for the 1985 discovery of fullerenes, the family of carbon molecules that includes nanotubes. His research in 2005 was concentrated largely on the radiofrequency cancer research project.

Rice materials scientist professor Boris Yakobson, Ph.D., a co-author on the paper, recalled meeting with Smalley in his hospital room at M. D. Anderson five days before his death.

"He looked very ill, breathing heavily through the oxygen mask, but all he wanted to do was talk about the physics of this very phenomenon," Yakobson said. "Oblivious of his ebbing health, Rick was focused in the future. He had told Congress in 1999 that nanotechnology would help revolutionize cancer treatment, and he was a scientist wanting to know whether this technology might be one of the things that would make that possible."

In the liver cancer experiment, a solution of single-walled carbon nanotubes was injected directly into the tumors. Four treated rabbits were then exposed to two minutes of radiofrequency treatment, resulting in thermal destruction of their tumors.

Carbon nanotubes are hollow cylinders of pure carbon that measure about a billionth of a meter, or one nanometer, across.

Control group tumors that were treated only by radiofrequency exposure or only by nanotubes were undamaged.

In lab experiments, two lines of liver cancer cells and one pancreatic cancer cell line were destroyed after being incubated with nanotubes and exposed to the radiofrequency field.

"I'm humbled by the results of this research," says Kanzius. "I realize it's early in the race, but Dr. Curley and his team have moved on this carefully with utmost speed. I look forward to continuing to work with them and hopefully to watching the first person be treated with this procedure. The race isn't over but it needs to be taken to the finish line."

Radiofrequency energy fields penetrate deeply into tissue, so it would be possible to deliver heat anywhere in the body if targeted nanotubes or other nanoparticles can be delivered to cancerous cells, Curley says. Without such a target, radio waves will pass harmlessly through the body.

An invasive technique known as radio frequency ablation is used to treat some malignant tumors, the authors note. It requires insertion of needle electrodes directly into the tumors. ncomplete tumor destruction occurs in 5 to 40 percent of cases, normal tissue is damaged and complications arise in 10 percent of patients who suffer such damage. Radiofrequency ablation is limited to liver, kidney, breast, lung and bone cancers.

This research appeared online ahead of December publication in the journal Cancer.

The research was supported by an American Association of Cancer Research Littlefield Grant, NASA and the Houston-based Alliance for NanoHealth, the National Science Foundation, the Center for Biological and Environmental Nanotechnology and the Fulbright Foundation.

Co-authors with Curley, Smalley, Kanzius and Yakobson are first authors Christopher J. Gannon, M.D., also of M. D. Anderson's Department of Surgical Oncology, and Paul Cherukuri, Ph.D. of Rice's Carbon Nanotechnology Laboratory and Department of Chemistry; Carter Kittrell, Ph.D., R. Bruce Weisman, Ph.D., Matteo Pasquali, Ph.D., and Howard K. Schmidt, Ph.D., all of Rice; and Laurent Cognet, Ph.D., of Rice and the Centre de Physique Moléculaire Optique et Hertzienne, Université Bordeaux, France.


Adapted from materials provided by University of Texas M. D. Anderson Cancer Center.

Rumsfeld 'kept up fear of terror attacks'

By Alex Spillius in Washington

Donald Rumsfeld, the former United States defence secretary, tried to maintain an atmosphere of fear in America as part of the Iraq war propaganda campaign, a series of leaked memos has shown.

One memo, written in April 2006, contained a list of instructions to Pentagon staff including "Keep elevating the threat" and "Talk about Somalia, the Philippines etc. Make the American people realise they are surrounded in the world by violent extremists".

Another said "link Iraq to Iran. Iran is the concern of the American people, and if we fail in Iraq, it will advantage Iran". He also urged staff to produce "bumper sticker statements" to rally the public around the war.

The memos, written between 2002 until shortly after his resignation in 2006, were leaked by undisclosed sources to the Washington Post. Rumsfeld was unpopular with many for his tough management style.

The newspaper reported that his emails were so numerous they were called "snowflakes". He would send between 20 and 60 a day, often instructing his team to refute negative news stories in the media.

One note will please Vladimir Putin, the Russian president. It said: "We are getting run out of Central Asia by the Russians. They are doing a considerably better job at bullying those countries than the US is doing to counter their bullying."

Rumsfeld also managed belatedly to embarrass Bush administration's attempts to win hearts and minds in the Arab world. In one memo he said: “Too often Muslims are against physical labour” because oil wealth had detached them from “the reality of work”.

A White House spokesman yesterday repudiated the comment. “It's not in line with the president's views,” said spokesman Dana Perino.

Keith Urbahn, an aide to Mr Rumsfeld, told the Washington Post that the published memos were "selective" and "gross mischaracterisations" carefully picked from some 20,000 while he was defence secretary. There was no comment from Mr Rumsfeld.