Scientists play down 'superweed'

Cultivated oilseed rape has a number of wild relatives

Scientists have urged caution over a study which may have found a so-called "superweed" growing at a site where GM crops had been trialled.

The charlock, a relative of oilseed rape, failed to shrivel up when daubed with the herbicide used to manage a biotech crop grown in the same field.

The creation of wild plants that pick up the traits of engineered crops has long been feared by anti-GM groups.

But researchers said their work showed the chances of such transfer were slim.

What is more, they argued, the study reinforced the view that the environmental impact was negligible.

"Herbicide-tolerant weeds tend to under-perform compared with wild type, so unless all its competitors have been sprayed out with the same herbicide, it won't thrive," commented Dr Les Firbank, who led the consortium of scientists on the recent UK Farm-Scale Evaluations (FSEs) of genetically modified plants.

"There's lots of evidence for that," he told the BBC News website.

Seed collection

The study was conducted by Centre for Ecology and Hydrology (CEH) researchers.

It looked for any evidence that a genetic trait in an oilseed rape, engineered to be resistant to a particular herbicide called Liberty, would pass to near-relatives growing wild in the field or at the margin.

The degree to which such transfer is possible informs the debate about superweeds, which some have claimed could upset ecological relationships in the countryside and so harm biodiversity.

We're seeing the real possibility of GM superweeds being created, with serious consequences for farmers and the environment Emily Diamand, FoE

The CEH team collected more than 95,000 seeds of wild relatives in and around the FSE trial sites and grew them up in greenhouses. These plants were then sprayed with Liberty (a glufosinate ammonium) to see if they had acquired herbicide tolerance - through their parents being pollinated by the GM rape.

The scientists found just two plants, of Brassica rapa or turnip rape, that showed resistance to the treatment; a rate of 0.000021.

But Brassica rapa is a very close relative of farmed oilseed rape and the discovery of some gene flow is not a huge surprise, say the scientists.

The CEH team also toured fields, daubing Liberty on the tissues of weeds and looking for the expected signs of die-back.

We do... need to improve our understanding of all aspects of gene transfer and this means we must take this into account with individual GM applications Elliot Morley, environment minister

The researchers found just one weed - what they believe was a charlock (Sinapis Arvensis) - which showed no reaction to the application.

DNA analysis on a leaf sample confirmed the gene trait from the engineered oilseed rape was present, but when the researchers returned the following year to the same field they could find no herbicide tolerance in seedlings of the charlocks growing there.

'Serious consequences'

Nonetheless, anti-GM group Friends of the Earth believes the existence of just one tolerant charlock should merit major concern.

It said that if GM oilseed rape were grown commercially, herbicide-resistant weeds could become widespread.

FoE argued that farmers would then have to use more - and more damaging - weedkillers to get rid of them, with knock-on impacts on the environment.

The FSEs were the largest study of their kind ever undertaken

"The government's trials have already shown that growing GM crops can harm wildlife. Now we're seeing the real possibility of GM superweeds being created, with serious consequences for farmers and the environment," commented FoE's GM campaigner Emily Diamand.

Environment Minister Elliot Morley said: "Even if a hybrid did once exist, it has disappeared. We do however need to improve our understanding of all aspects of gene transfer and this means we must take this into account with individual GM applications.

"Our top priority is to safeguard human health and the environment. There are no trials of GM oilseed rape in the UK at the moment. No consents for commercial cultivation in the EU have been issued and there are none in the pipeline."

The £6m FSEs were described as the biggest ecological experiment in the world and a model for measuring the impact of new farming techniques on the environment.

The results for four types of engineered crops - a spring-sown oilseed rape, a winter-sown oilseed rape, a sugar beet and a maize - were tested over a period of three years.

All were engineered to be resistant to a particular herbicide, which meant they would continue to prosper when the weedkiller was applied to the "pest" plants in the field.

Only the maize came through the trials with approval because the field management used to cultivate the bitotech crop appeared to be kinder on wildlife than the regime employed on the conventional maize grown as a controlled comparison.

Flickr tops TIME's list of Best 50 Websites of 2009

The hottest thing on the Internet is not social networking websites like Facebook and Twitter, but Flickr-the popular photo-sharing portal - and the proof is: it has topped TIME's list of the best 50 websites this year.

One of the noticeable trends in this year's list, which was released this week, was on-demand video services, like YouTube, Vimeo and US services Hulu and Netflix.

However, the top two in the list were related to photographs, with California Coastline following Flickr at the second spot.

Third in the list was bookmark website Delicious, while community weblog Metafilter stood at the fourth place.

Popurls, the mashup of the web's most visited social news sites and portals, grabbed the fifth spot in the list.

Twitter ranked sixth and Facebook came 31st in the list, while YouTube and Hulu came at 12th and 14th place in the list.

TIME's list of 50 Best Websites of 2009 is:. Flickr

2. California Coastline

3. Delicious

4. Metafilter

5. popurls

6. Twitter

7. Skype

8. Boing Boing

9. Academic Earth

10. OpenTable

11. Google

12. YouTube

13. Wolfram|Alpha

14. Hulu

15. Vimeo

16. Fora TV

17. Craiglook

18. Shop Goodwill

19. Amazon

20. Kayak

21. Netflix

22. Etsy

23. PropertyShark.com

24. Redfin

25. Wikipedia

26. Internet Archive

27. Kiva

28. ConsumerSearch

29. Metacritic

30. Pollster

31. Facebook

32. Pandora and Last.fm

33. Musicovery

34. Spotify

35. Supercook

36. Yelp

37. Visuwords

38. CouchSurfing

39. BabyNameWizard.com's NameVoyager

40. Mint

41. TripIt

42. Aardvark

43. drop.io

44. Issuu

45. Photosynth

46. OMGPOP

47. WorldWideTelescope

48. Fonolo

49. Get High Now

50. Know Your Meme (ANI)

A safer stem cell: on guard against cancer

Before stem cell therapies become mainstream, several hurdles must be overcome. One challenge is developing air-tight approaches to assure that stem cell transplantation does not give rise to tumors. Another is finding safe ways to induce pluripotency in adult stem cells, which can then be used for transplantation. In Bedside to Bench, Evan Snyder and Rahul Jandial discuss the risks of tumorigenesis in stem cell therapies, and, in Bench to Bedside, Laura Clarke and Derek van der Kooy examine new ways to induce pluripotency.

One month after the US Food and Drug Administration (FDA) approved the first clinical trial of human embryonic stem cells (hESCs) (for spinal cord injury), a study appeared¹ reporting tumors in the brain and spinal cord of a child who had received intracranial and intrathecal injections of what were purported to be neural stem cells (NSCs). The child had traveled to Moscow to receive an 'experimental therapy' for ataxia telangiectasia, a rare, incurable neurodegenerative condition.

REFERENCE: http://www.nature.com/nm/journal/v15/n9/full/nm0909-999.html

"Mummy's Curse" Legend Won't Die

Movie mummies are known for two things: fabulous riches and a nasty curse that brings treasure hunters to a bad end. But Hollywood didn't invent the curse concept.

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Mummy of King Tutankhamun

Photograph by Kenneth Garrett

The "mummy's curse" first enjoyed a worldwide vogue after the 1922 discovery of King Tutankhamun's tomb in the Valley of the Kings near Luxor, Egypt.

When Howard Carter opened a small hole to peer inside the tomb at treasures hidden for 3,000 years, he also unleashed a global passion for ancient Egypt.

Tut's glittering treasures made great headlines—and so did sensationalistic accounts of the subsequent death of expedition sponsor Lord Carnarvon.

In reality, Carnarvon died of blood poisoning and only six of the 26 people present when the tomb was opened died within a decade. Carter, surely any curse's prime target, lived until 1939.

But while the pharaoh's curse may lack bite, it hasn't lost the ability to fascinate audiences—which may be how it originated in the first place.

Birth of the Curse

The late Egyptologist Dominic Montserrat conducted a comprehensive search and concluded that the concept began with a strange "striptease" in 19th-century London.

"My work shows quite clearly that the mummy's curse concept predates Carnarvon's Tutankhamen discovery and his death by a hundred years," Montserrat told theIndependent (U.K.) in an interview some years before his own death.

Montserrat believed that a lively stage show in which real Egyptian mummies were unwrapped inspired first one writer, and subsequently several others, to pen tales of mummy revenge.

The thread was even picked up by Little Women author Louisa May Alcott in her nearly unknown volume Lost in a Pyramid; or, The Mummy's Curse.

"My research has not only confirmed that there is, of course, no ancient Egyptian origin of the mummy's curse concept, but, more importantly, it also reveals that it didn't originate in the 1923 press publicity about the discovery of Tutankhamen's tomb either," Montserrat stressed to the Independent.

But Salima Ikram, an Egyptologist at the American University in Cairo and a National Geographic Society grantee, believes the curse concept did exist in ancient Egypt as part of a primitive security system.

She notes that some mastaba (early non-pyramid tomb) walls in Giza and Saqqara were actually inscribed with "curses" meant to terrify those who would desecrate or rob the royal resting place.

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King Tutankhamun's coffin

Photograph by Kenneth Garrett

"They tend to threaten desecrators with divine retribution by the council of the gods," Ikram said. "Or a death by crocodiles, or lions, or scorpions, or snakes."

Tomb Toxin Threat?

In recent years some have suggested that the pharaoh's curse was biological in nature.

Could sealed tombs house pathogens that can be dangerous or even deadly to those who open them after thousands of years—especially people like Lord Carnarvon with weakened immune systems?

The mausoleums house not only the dead bodies of humans and animals but foods to provision them for the afterlife.

Lab studies have shown some ancient mummies carried mold, including Aspergillus niger and Aspergillus flavus, which can cause congestion or bleeding in the lungs. Lung-assaulting bacteria such as Pseudomonas and Staphylococcus may also grow on tomb walls.

These substances may make tombs sound dangerous, but scientists seem to agree that they are not.

F. DeWolfe Miller, professor of epidemiology at the University of Hawaii at Manoa, concurs with Howard Carter's original opinion: Given the local conditions, Lord Carnarvon was probably safer inside Tut's tomb than outside.

"Upper Egypt in the 1920s was hardly what you'd call sanitary," Miller said. "The idea that an underground tomb, after 3,000 years, would have some kind of bizarre microorganism in it that's going to kill somebody six weeks later and make it look exactly like [blood poisoning] is very hard to believe."

In fact, Miller said, he knows of no archaeologist—or a single tourist, for that matter—who has experienced any afflictions caused by tomb toxins.

But like the movie mummies who invoke the malediction, the legend of the mummy's curse seems destined never to die.

REFERENCE: http://www.nationalgeographic.com/history/ancient/mummy-curse.html

Scientists Try to Crack Stonehenge's Prehistoric Puzzles

Stonehenge in southern England ranks among the world's most iconic archaeological sites and one of its greatest enigmas. The megalithic circle on Salisbury Plain inspires awe and fascination—but also intense debate some 4,600 years after it was built by ancient Britons who left no written record.

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The ruins of Stonehenge in Wiltshire, England

Photograph by Jodi Cobb

The monument's mysterious past has spawned countless tales and theories. According to folklore, Stonehenge was created by Merlin, the wizard of Arthurian legend, who magically transported the massive stones from Ireland, where giants had assembled them. Another legend says invading Danes put the stones up, and another theory says they were the ruins of a Roman temple. Modern-day interpretations are no less colorful: some argue that Stonehenge is a spacecraft landing area for aliens, and even more say it's a giant fertility symbol in the shape of female genitalia.

Archaeological investigation of the site dates back to the 1660s, when it was first surveyed by antiquarian John Aubrey. Aubrey wrongly credited Stonehenge to the much later Celts, believing it to be a religious center presided over by Druid priests.

Centuries of fieldwork since show the monument was more than a millennium in the making, having started out 5,000 years ago as a circular earthen bank and ditch. A complicated pattern of wooden posts was replaced in about 2600 B.C. by 80 dolerite bluestones from Wales that were rearranged at least three times once the larger sarsen stones were added several hundred years later. These huge sandstone blocks, each weighing around 25 tons, were transported some 19 miles (30 kilometers) to create a continuous outer circle with five trilithons (pairs of uprights with a lintel on top) forming a horseshoe within. It's been estimated that it took well over 20 million hours to construct Stonehenge.

Holy Site or Scientific Observatory?

Modern debate over the monument's meaning has two main camps: those who see it as a holy site, and others who believe it represents a scientific observatory. Both camps base their theories on the site's celestial influence, with alignments to the sun and moon taken as evidence of rituals linked to the changing seasons and the summer and winter solstices. Alternatively, alignments identified particularly with stars point to a megalithic calendar used for working out dates or to reflect or predict astronomical events such as solar eclipses.

Recently a radical new theory has emerged—that Stonehenge served as a "prehistoric Lourdes" where people came to be healed. This idea revolves around the smaller bluestones, which, researchers argue, must have been credited with magical powers for them to have been floated, dragged, and hauled 145 miles (233 kilometers) from west Wales. A team lead by Tim Darvill of Bournemouth University, U.K., announced in 2005 that it had located the quarry the bluestones came from, only for another study to suggest the stones had made the journey earlier, powered naturally by ice age glaciers. Excavations at Stonehenge co-directed by Darvill in April 2008 may yet bolster a hypothesis also based on a number of Bronze Age skeletons unearthed in the area that show signs of bone deformities.

Competing to solve the enduring prehistoric puzzle is Sheffield University's Mike Parker Pearson, co-leader of the Stonehenge Riverside Project, which is partly funded by the National Geographic Society. Latest discoveries by the project team appear to support Parker Pearson's claim that Stonehenge was a center for ancestor worship that was linked by the River Avon and two ceremonial avenues to a matching wooden circle at nearby Durrington Walls. The two circles with their temporary and permanent structures represented, respectively, the domains of the living and the dead, according to Parker Pearson.

"Stonehenge isn't a monument in isolation," he says. "It is actually one of a pair—one in stone, one in timber. The theory is that Stonehenge is a kind of spirit home to the ancestors."

Stonehenge Was Cemetery First and Foremost, Study Says.

REFERENCE: http://www.nationalgeographic.com/history/ancient/stonehenge.html

Holy Grail Legend Endures for Centuries

In the Bible, the cup used by Jesus Christ at the Last Supper is little more than a prop, given no particular prominence. But over the centuries, the fate of this now legendary vessel, the so-called Holy Grail, has come to haunt stories ranging from Arthurian legend to Indiana Jones and the Last Crusade.

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Painting of Sir Galahad discovering the Holy Grail

Photograph by Burstein Collection/CORBIS

Because Jesus used the cup during the Last Supper in what became the basis for the Christian Eucharist, the Grail has for many taken on the aura of an extremely holy relic.

The Grail takes on even greater significance from tales that Joseph of Arimathea, in whose tomb Jesus was placed prior to his resurrection, used the cup to collect Jesus' blood while he was being crucified.

Theories abound as to where the cup eventually went. One says the Knights Templar, a medieval military order that persisted for more than 200 years, took it from Jerusalem during the Crusades.

There's also a story in which Joseph carries the Grail to Glastonbury, England, a Roman outpost at the time of Christ's crucifixion. In 1906, in fact, a blue bowl claimed by some to be the Grail was found there, and since then at least four other cups have been proclaimed to be the Grail, two from England and Wales and two from the Middle East.

But the reality, says historian Richard Barber, author of The Holy Grail: Imagination and Belief, is that the Grail stories are just that—stories.

'Poet With a Remarkable Imagination'

"The whole thing is basically the imagination of a 12th-century poet," he says.

The poet, Chrétien de Troyes, created the initial, "fairly unspecific" story, Barber says, as a way of examining the theology of the Roman Catholic Mass.

"That may sound terribly obscure," he says, "but in the 12th century, the nearest you got to drama, theater, and spectacle, if you were an ordinary person, was the celebration of Mass."

In working through his story, Barber says, Chrétien worked backward from his own time to the time of Christ. "So you've got a poet with a remarkable imagination who invents the idea of the Grail."

In fact, Barber says, the most remarkable thing about the legend is simply the fact that the story appears to have originated with a single writer. "There are so many people out there looking for the thing," he says. "Actually it's more exciting that someone can imagine something in the 12th century ... that is still a hot concept 800 years later."

Not that this means there wasn't a cup. But even if it still exists, Barber asks, how would you know if you found it? "You are not going to come up with a cup with a neat label tied around it saying 'This is the cup of the Last Supper, guaranteed authentic.'"

Archaeologist Fred Hiebert, a National Geographic Society fellow, agrees. "I'm always interested in finding remains of ancient people, especially pottery or metal vessels," he says. But when it comes to linking any such object to a specific legend or biblical story? "We can't do it."

REFERENCE: http://www.nationalgeographic.com/history/ancient/holy-grail.html

Puzzling Mosquito May Complicate Malaria Control

A newly discovered species of mosquito may complicate malaria-control efforts in parts of Africa. Researchers have identified an insect that looks nearly identical to a species that carries the disease, yet that may or may not transmit malaria. If ongoing studies find that the mosquito does not carry the malaria parasite, vector-control teams could waste valuable resources, including insecticides and bed nets, fighting a harmless insect.

Africa is home to at least 140 species of Anopheles mosquitoes. But only seven species are known to transmit the malaria parasite to humans, including members of the An. funestus and An. gambiae groups.

"Confusers." These mosquito larvae from Malawi belong to a new Anopheles species

A South African field team found the new mosquito species inside reed huts in rural villages in the malaria-prone nation of Malawi. Although it looked just like the vector An. funestus, genetic testing revealed that it did not match any of the known Anopheles species. So far, no specimens of the new species have been found with the malaria parasite. "If this mosquito is not a malaria vector, it is certainly a 'confuser'--looking exactly like one of the major vectors," says medical entomologist Richard Hunt, a member of the team that reports its finding this month in theAmerican Journal of Tropical Medicine and Hygiene.

And that could exacerbate vector-control efforts in Malawi, says study co-author Maureen Coetzee, who directs the medical entomology research unit at the University of the Witwatersrand in Johannesburg, South Africa. "Malaria-control resources are limited, and it would be a waste of money to kill off a mosquito species that may look exactly like a malaria vector but is not," she says. "Malawi may have to invest in a basic molecular laboratory to tell the difference."

The finding "explains a number of the rather strange results we were getting" in trying to identify mosquito species in Malawi using routine polymerase chain reaction assays, says insect molecular biologist Janet Hemingway, director of the Liverpool School of Tropical Medicine in the U.K., who was not involved in the study.

"It's more than a little depressing that after a century of work, we still seem not to know how many species there are in the funestus group, let alone how good each is at transmitting malaria," adds evolutionary biologist Andrew Read of Pennsylvania State University, University Park, who studies the evolutionary genetics of malaria and its vectors.

Indeed, Coetzee says there are likely many more Anopheles species in relatively unexamined regions of Africa such as the Democratic Republic of the Congo: "There is still an awful lot we don't know."

REFERENCE: http://sciencenow.sciencemag.org/cgi/content/full/2009/902/3?etoc

Divided Brains Are Smarter

The two sides of the brain are responsible for different tasks in many animals. In people, for example, the left side is usually the language center, whereas the right side handles more visual and spatial chores. Now, research on parrots shows that this separation increases brainpower.

For many years, researchers thought that the division of labor in the brain, known as cerebral lateralization, was unique to humans. But recent research has shown that such lateralization is actually pervasive in vertebrates. A leading theory suggests that the attribute leads to faster, more accurate problem-solving. The theory holds true for minnows--the ones whose brains are lateralized are better at catching shrimp while simultaneously keeping an eye out for predators--but many other species haven't been tested.

Among birds, parrots and crows are renowned for their cleverness. So behavioral ecologist Culum Brown and biologist Maria Magat of Macquarie University in Sydney, Australia, tested 40 parrots from eight different Australian species. Just as right-handedness indicates left-brain dominance in most humans, brain laterality was determined in birds by observing which eye each bird used to fixate on a piece of food and which foot grabbed it. Each bird received a laterality score ranging from 0 (no preference) to 5 (strongly lateralized).

Bird brain. Most cockatoos have strong left-foot preference.

REFERENCE: http://sciencenow.sciencemag.org/cgi/content/full/2009/902/4?etoc

The parrots were then given two tests. One involved picking out seeds from a background of similar-looking pebbles; their performance was evaluated by dividing the number of seeds consumed by the number of pecks. The more challenging task required birds to obtain food hanging below their perch on a 50-centimeter-long string. Hauling up the prize is a problem requiring a lot of beak, foot, and eye coordination.

Today in the Proceedings of the Royal Society B, the researchers report that birds with stronger brain asymmetries tended to be more successful. Cockatoos tended to be the brightest and budgerigars the dimmest, but within species there was variability according to the degree of laterality. In the string test, for example, five strongly lateralized birds (one right-footed and the rest left-footed) from four species succeeded on the first try. Birds with no lateralization performed the worst--in the pebble test they scored 55% compared to 95% in the strongly lateralized individuals. "These individuals have problems with coordination," says Brown. "They try a mixture of approaches, and sometimes they manage to muddle through it."

The authors say the experiments show that cerebral lateralization promotes fast and accurate thinking and coordinated movements--and hence would increase the birds' fitness, or ability to survive and reproduce.

Cognitive neuroscientist Giorgio Vallortigara of the University of Trento in Italy, who has studied performance of chicks on the seed-pecking test, says, "The idea of a link between lateralization strength and cognitive abilities has been around ... for many years, but little comparative and experimental work has been done with animals." This study, he says, provides "fascinating confirmation of the link between higher cognition and brain asymmetry."

Experimental Drug Shows Promise for Several Cancers

In the first clinical proof of its kind, a drug has dramatically shrunk cancerous tumors by disrupting a key genetic pathway. But a study targeting one deadly brain cancer, medulloblastoma, ended in disappointment as the patient's once-tamed tumor quickly developed resistance to the drug and killed him.

The drug, GDC-0449, was developed at Genentech in South San Francisco, California. It locks onto and deactivates a protein, Smoothened, that activates the Hedgehog signaling pathway, which orchestrates how embryonic stem cells develop. In adults, the Hedgehog pathway is dormant, but it awakens in many cancers.

In a paper published online today in The New England Journal of Medicine (NEJM), scientists treated 33 people with one such cancer, basal cell carcinoma, a common skin cancer. The carcinoma had advanced so far that conventional treatments were useless. Nevertheless, after a median treatment of 10 months, 18 patients improved substantially on the drug, and it arrested the spread of cancer in 11 others. Scientists have long suspected that disrupting the Smoothened-Hedgehog link would shrink tumors without messy radiation or chemotherapy. Now they have proof.

Still more dramatic was the response of a 26-year-old man with medulloblastoma, reported in a second paper inNEJM. Hedgehog signals have been implicated in one-third of human medulloblastoma cases. It's an aggressive cancer, and tumors had colonized the man's entire body. "He came in very sick, thinned, in a lot of pain, not very active, needing frequent blood transfusions," says Charles Rudin, associate director of clinical research at Johns Hopkins University in Baltimore, Maryland, who treated the patient. "His prognosis was terrible."

Other treatment options, including radiation, had failed, so in late April 2008, Rudin began giving the man 540 mg of GDC-0449 daily. By 23 June, he had gained 7 kilograms and reported that he was in far less pain than before. He even began exercising again. The numerous blotches on his positron emission tomography (PET) scans had been reduced to a few isolated islands of cancer (see picture). But on 23 July, a PET scan revealed that the cancer had returned in a resistant form and was almost as widespread as before. "It was a big disappointment," says Rudin. The young man died 23 September.

GDC-0449 seems promising for skin cancer, say several experts, and Genentech has already moved into phase II clinical trials. It remains unclear how well the drug will work for medulloblastoma, however. This brain cancer usually targets children (the median age of victims is 5), and because the Hedgehog pathway controls aspects of skeletal development, shutting it off might not be safe. The class of compounds that includes GDC-0449 could also help contain other cancers, such as ovarian and colorectal cancers, that are not triggered in the same way as medulloblastoma or basal cell carcinoma but that are still partly driven by aberrant Hedgehog signaling. Genentech is already testing drugs along these lines.

Meanwhile, in a separate study published online today in Science, an overlapping team at Genentech led by biologist Frederic de Sauvage describes the mechanism by which the man's brain tumor developed resistance. The team found that a point mutation in Smoothened, a G-to-C substitution at position 1697 along the protein's length, prevented GDC-0449 from binding but did not alter the ability of Smoothened to switch on the Hedgehog pathway.

Further research showed that a similar resistance had developed in mice with mutated medulloblastoma. The point substitution was different but occurred in the exact same spot and interfered with the drug in the same way. That correspondence between humans and mice hints that preventing drugs like GDC-0449 from locking onto Smoothened could be a common way to develop resistance. However, scientists can now study the resistance, and they hope to devise ways around it.

Tom Curran of Children's Hospital of Philadelphia in Pennsylvania praises the papers for providing a firm basis for understanding Smoothened-related cancers. "It's a landmark study and will raise a lot of questions about how to proceed with personalized medicine in the future," he says.

Dramatic but transient. Within 2 months, a novel drug candidate shriveled a man's metastasized cancer (center). One month later, the cancer, now resistant, resurged.

REFERENCE:http://sciencenow.sciencemag.org/cgi/content/full/2009/902/1?etoc

Genes That Make Us Human

Finding genes that have evolved in humans among our genome's 3 billion bases is no easy feat. But now, a team has pinpointed three genes that arose from noncoding DNA and may help make our species unique.

Most genes have deep histories, with ancestors that reach down into the tree of life, sometimes all the way back to bacteria. The gradual increase from the few thousand genes in a bacterium to the tens of thousands of genes in a person came primarily through genome- and gene-duplication events, which created extra sets of genes free to evolve new sequences and new functions. Much of this duplication happened long before humans evolved, though some duplications occurred in the human lineage to create exclusively human twins of existing genes.

But in 2006, geneticists showed for the first time that they could identify truly novel genes. In fruit flies, they came across five young genes that were derived from "noncoding" DNA between existing genes and not from preexisting genes. As a result, other researchers started looking for novel genes in other species.

Meanwhile, while looking for gene duplications in humans, geneticists Aoife McLysaght and David Knowles of Trinity College Dublin kept coming across genes that seemed to have no counterparts in other primates, suggesting that new genes arose in us as well. To determine which of these genes with no counterparts were de novo genes, McLysaght and Knowles first used a computer to compare the human, chimp, and other genomes. They eliminated all but three of the 644 candidates because their sequence in the database was not complete--or they had equivalents in other species.

Next, they searched the chimp genome for signs of each gene's birth. "We strove hard to identify the noncoding DNA that gave rise to the gene," McLysaght says. Only by finding that DNA could they be sure that the gene wasn't already present in the chimp genome but was somehow unrecognizable to gene-finding programs. At three locations where the chimp and human genomes were almost identical, telltale mutations indicated that it was impossible to get a viable protein from the chimp DNA sequence. In contrast, the human version of each sequence had mutations that made it a working gene, the researchers report online tomorrow in Genome Research.

The researchers were able to verify that the genes worked by checking messenger RNA databases and protein surveys done by other scientists. They are now using antibodies to find out where in the cells these proteins are active and are trying to disable the genes in cells to tease out their functions.

The researchers analyzed only a subset of the human genome. Extrapolating to the full genome, they think humans have evolved at least 18 new genes. That's a small number compared to our total of 24,000 but nonetheless an important one. "The distinction between humans and other apes must lie somewhere in the small genetic differences between the species," says McLysaght.

Unlike duplicated genes, these are genes that "they really knew are human-specific," says Laurent Duret, a molecular evolutionary biologist at the University of Lyon in France. When he first heard about this project, he was skeptical, but not anymore. "It's the first convincing evidence of a real innovation in humans."

These three young genes join several hundred other uniquely human genomic features, including gene duplications, that provide tantalizing hints of what makes us human. But, says evolutionary biologist Gregory Wray of Duke University in Durham, North Carolina, researchers still have no clue what most of these genes do.

Nitrous oxide is top destroyer of ozone layer: study

Nitrous oxide emissions caused by human activity have become the largest contributor to ozone depletion and are likely to remain so for the rest of the 21st century, a US study has concluded.

The study by the National Oceanographic and Atmospheric Agency said efforts to reduce chlorofluorocarbons (CFCs) in the atmosphere over the past two decades were "an environmental success story.

"But manmade nitrous oxide is now the elephant in the room among ozone-depleting substances," said A. R. Ravishankara, lead author of the study, which was published Friday in the journal Science.

While nitrous oxide's role in depleting the ozone layer has been known for decades, the study marks the first time that its impact has been measured using the same methods as CFCs and other ozone depleting substances.

Emissions and production of those substances are regulated under the 1987 Montreal Protocol.

But the treaty excludes nitrous oxides, which are emitted by agricultural fertilizers,livestock

manure, sewage treatment, combustion and certain other industrial processes.

Since nitrous oxide is also a greenhouse gas, the scientists said reducing emissions from manmade sources would be good for the ozone layer and help temper climate change.

Watermelons: A renewable energy source?

U.S. scientists say they've discovered watermelon juice can be a valuable source of biofuel

, with the juice from rejected watermelons fermented into ethanol.

U.S. Department of Agriculture research chemist Wayne Fish and a team of scientists at the USDA's South Central Agricultural Research Laboratory in Lane, Okla., evaluated the biofuel potential of juice from 'cull' watermelons -- those not sold due to cosmetic imperfections. Such melons are currently plowed back into the field.

"About 20 percent of each annual watermelon crop is left in the field because of surface blemishes or because they are misshapen," said Fish. "We've shown that the juice of these melons is a source of readily fermentable sugars, representing a heretofore untapped feedstock for ethanol biofuel production".

The study is reported in the journal Biotechnology for Biofuels.

Honey, I Blew Up The Tokamak

Magnetic reconnection could be the Universe's favorite way to make things explode. It operates anywhere magnetic fields pervade space--which is to say almost everywhere. On the sun magnetic reconnection causes solar flares as powerful as a billion atomic bombs.

In Earth's atmosphere, it fuels magnetic storms and auroras. In laboratories, it can cause big problems in fusion reactors. It's ubiquitous.

The problem is, researchers can't explain it.

The basics are clear enough. Magnetic lines of force cross, cancel, reconnect and-Bang! Magnetic energy is unleashed in the form of heat and charged-particle kinetic energy.

But how? How does the simple act of crisscrossing magnetic field lines trigger such a ferocious explosion?

"Something very interesting and fundamental is going on that we don't really understand - not from laboratory experiments or from simulations," says Melvyn Goldstein, chief of the Geospace Physics Laboratory at NASA's Goddard Space Flight Center.

NASA is going to launch a mission to get to the bottom of the mystery. It's called MMS, short for Magnetospheric Multiscale Mission, and it consists of fourspacecraft which will fly through Earth's magnetosphere to study reconnection in action. The mission passed its preliminary design review in May 2009 and was approved for implementation in June 2009. Engineers can now start building the spacecraft.

"Earth's magnetosphere is a wonderful natural laboratory for studying reconnection," says mission scientist Jim Burch of the Southwest Research Institute. "It is big, roomy, and reconnection is taking place there almost non-stop."

In the outer layers of the magnetosphere, where Earth's magnetic field meets thesolar wind, reconnection events create temporary magnetic "portals" connecting Earth to the sun. Inside the magnetosphere, in a long drawn-out structure called "the magnetotail," reconnection propels high-energy plasma clouds toward Earth, triggering Northern Lights when they hit. There are many other examples, and MMS will explore them all.

The four spacecraft will be built at the Goddard Space Flight Center. "Each observatory is shaped like a giant hockey puck, about 12 feet in diameter and 4 feet in height," says Karen Halterman, MMS Project Manager at Goddard.

The mission's sensors for monitoring electromagnetic fields and charged particles are being built at a number of universities and laboratories around the country, led by the Southwest Research Institute. When the instruments are done, they will be integrated into the spacecraft frames at Goddard. Launch is scheduled for 2014 onboard an Atlas V rocket.

Any new physics MMS learns could ultimately help alleviate the energy crisis on Earth.

"For many years, researchers have looked to fusion as a clean and abundant source of energy for our planet," says Burch.

"One approach, magnetic confinement fusion, has yielded very promising results with devices such as tokamaks. But there have been problems keeping the plasma (hot ionized gas) contained in the chamber."

"One of the main problems is magnetic reconnection," he continues. "A spectacular and even dangerous result of reconnection is known as the sawtooth crash. As the heat in the tokamak builds up, the electron temperature reaches a peak and then 'crashes' to a lower value, and some of the hot plasma escapes. This is caused by reconnection of the containment field."

In light of this, you might suppose that tokamaks would be a good place to study reconnection. But no, says Burch.

Reconnection in a tokamak happens in such a tiny volume, only a few millimeters wide, that it is very difficult to study. It is practically impossible to build sensors small enough to probe the reconnection zone.

Earth's magnetosphere is much better. In the expansive magnetic bubble that surrounds our planet, the process plays out over volumes as large as tens of kilometers across. "We can fly spacecraft in and around it and get a good look at what's going on," he says.

That is what MMS will do: fly directly into the reconnection zone. The spacecraft are sturdy enough to withstand the energetics of reconnection events known to occur in Earth's magnetosphere, so there is nothing standing in the way of a full two year mission of discovery.

Inside a tokamak. Image credit: Lawrence Berkeley Labs