Aug 6, 2011

Designing Diamond Circuits for Extreme Environments

There is a new way to design computer chips and electronic circuitry for extreme environments: make them out of diamond.

A team of electrical engineers at Vanderbilt University has developed all the basic components needed to create microelectronic devices out of thin films of nanodiamond. They have created diamond versions of transistors and, most recently, logical gates, which are a key element in computers.

"Diamond-based devices have the potential to operate at higher speeds and require less power than silicon-based devices," Research Professor of Electrical Engineering Jimmy Davidson said. "Diamond is the most inert material known, so our devices are largely immune to radiation damage and can operate at much higher temperatures than those made from silicon."

Their design of a logical gate is described in the Aug. 4 issue of the journal Electronics Letters. Co-authors of the paper are graduate student Nikkon Ghosh, Professor of Electrical Engineering Weng Poo Kang.

Not an engagement ring

Davidson was quick to point out that even though their design uses diamond film, it is not exorbitantly expensive. The devices are so small that about one billion of them can be fabricated from one carat of diamond. The films are made from hydrogen and methane using a method called chemical vapor deposition that is widely used in the microelectronics industry for other purposes. This deposited form of diamond is less than one-thousandth the cost of "jewelry" diamond, which has made it inexpensive enough so that companies are putting diamond coatings on tools, cookware and other industrial products. As a result, the cost of producing nanodiamond devices should be competitive with silicon.

Potential applications include military electronics, circuitry that operates in space, ultra-high speed switches, ultra-low power applications and sensors that operate in high radiation environments, at extremely high temperatures up to 900 degrees Fahrenheit and extremely low temperatures down to minus 300 degrees Fahrenheit.

Hybrid of old and new

The nanodiamond circuits are a hybrid of old fashioned vacuum tubes and modern solid-state microelectronics and combine some of the best qualities of both technologies. Nanodiamond devices consist of a thin film of nanodiamond that is laid down on a layer of silicon dioxide. Much as they do in vacuum tubes, the electrons move through vacuum between the nanodiamond components, instead of flowing through solid material the way they do in normal microelectronic devices. As a result, they require vacuum packaging to operate.

"The reason your laptop gets hot is because the electrons pumping through its transistors bump into the atoms in the semiconductor and heat them up," Davidson said. "Because our devices use electron transport in vacuum they don't produce nearly as much heat."

Read more at Science Daily

Making Sperm from Stem Cells in a Dish

Researchers have found a way to turn mouse embryonic stem cells into sperm. This finding, reported in the journal Cell in a special online release on August 4th, opens up new avenues for infertility research and treatment. A Kyoto University team has coaxed mouse embryonic stem cells into sperm precursors, called primordial germ cells (PGCs), and shown that these cells can give rise to healthy sperm.

The researchers say that such in vitro reconstitution of germ cell development represents one of the most fundamental challenges in biology.

When transplanted into mice that were unable to produce sperm normally, the stem cell derived PGCs produced normal-looking sperm, which were then used to successfully fertilize eggs. These fertilized eggs, when transplanted into a recipient mother, produced healthy offspring that grew into fertile male and female adult mice. The same procedure could produce fertile offspring from induced pluripotent stem cells that are often derived from adult skin cells.

More at Science Daily

King Tut's Treasures Return Home

A trove of small figurines and jewelry that was illegally taken from King Tutankhamun's treasure- packed tomb has been returned to Egypt after more than 50 years, local authorities announced this week.

Consisting of 19 small-scale objects, the trove entered the Egyptian collection at The Metropolitan Museum of Art (Met) in New York from the 1920s to 1940s.

After an in-depth investigation into the history of the relics, the Met's experts concluded that "without doubt" the objects "originated in Tutankhamun's tomb."

"Fifteen of the 19 pieces have the status of bits or samples. The remaining four are of significant art-historical interest," Mohamed Abdel Maksoud, Secretary General of the Supreme Council of Antiquities (SCA), said in a statement.

They include a three-quarter-inch-high bronze dog, part of a handle, a broad collar accompanied by additional beads and a lapis-lazuli sphinx that might have adorned a bracelet worn by King Tut.

The repatriation is the result of an agreement made last November between the museum and the then-antiquities chief Zahi Hawass. The world famous archaeologist, who claimed to have secured the return of some 5,000 treasures during his tenure, was fired last month after accusations of close ties to ex-President Hosni Mubarak, who was ousted in uprisings last February.

"These objects were never meant to have left Egypt, and therefore should rightfully belong to the Government of Egypt," Thomas P. Campbell, director of the Met, said in a statement.

At the time of the agreement, Hawass said the objects would be reunited with the other treasures of the boy king, who reigned about 1336-1327 B.C., to be first shown at the Egyptian Museum in Cairo and then permanently at the Grand Egyptian Museum at Giza when it opens in 2012.

The attribution to King Tut's tomb appears to confirm speculations that several objects were stolen from the tomb, ending up in foreign collections.

The claim was first made in 1978 by the late Thomas Hoving, a former director of the Met, in his best-selling book, "Tutankhamun: The Untold Story."

Hoving argued that Howard Carter, who discovered King Tutankhamun's tomb in 1922 in the Valley of the Kings, stole objects from the site and had a secret arrangement to sell them to the Met.

In "one of the best kept secrets in the history of Egyptology," as Hoving wrote, the story goes that Carter and Carnavon secretly searched the tomb's inner chambers, pocketed several objects, then resealed the tomb's aperture and waited for the arrival of Egyptian authorities.

At that time,the Egyptian government generally allowed excavators to keep a substantial portion of the finds from digs undertaken and financed by them.

But in the case of Tutankamun's tomb, no such partition took place.

"Conjectures soon started, suggesting that certain objects of high quality, dating roughly to the time of Tutankhamun and residing in various collections outside Egypt, actually originated from the king's tomb," the SCA said.

Such conjectures intensified after the death of Howard Carter in 1939, when a number of artifacts were found to be part of his estate.

Indeed, the majority of the 19 objects repatriated by the Met were found among the contents of Carter's house at Luxor (all of the contents of that house were bequeathed by Carter to the Metropolitan Museum.)

"When the Metropolitan Museum acquired these objects, the whole group had been subjected to careful scrutiny by experts and representatives of the Egyptian government; and subsequent research has found no evidence of such a provenance in the overwhelming majority of cases," the SCA said.

For example, evidence indicates that objects that entered the Met from the private collection of Lord Carnarvon in 1926 do not belong to King Tut's tomb, the Egyptian authorities stated.

Read more at Discovery News

Aug 5, 2011

Light Shed On South Pole Dinosaurs

Dog-sized dinosaurs that lived near the South Pole, sometimes in the dark for months at a time, had bone tissue very similar to dinosaurs that lived everywhere on the planet, according to a doctoral candidate at Montana State University.

That surprising fact falsifies a 13-year-old study and may help explain why dinosaurs were able to dominate the planet for 160 million years, said Holly Woodward, MSU graduate student in the Department of Earth Sciences and co-author of a paper published Aug. 3 in the journal PLoS ONE.

"If we were trying to find evidence of dinosaurs doing something much different physiologically, we would expect it to be found in dinosaurs from an extreme environment such as the South Pole," Woodward said. "But based on bone tissues, dinosaurs living within the Antarctic Circle were physiologically similar to dinosaurs living everywhere else.

"This tells us something very interesting; that basically from the very start, early dinosaurs, or even the ancestors of dinosaurs, evolved a physiology that allowed an entire group of animals to successfully exploit a multitude of environmental conditions for millions of years," Woodward said.

Jack Horner, Woodward's adviser and Regents Professor of Paleontology/Curator of Paleontology at MSU's Museum of the Rockies, said Woodward's findings are consistent with other results from the museum's histology lab.

"I think the most important finding is that polar dinosaurs don't seem to be any different than any other dinosaurs in respect to how their bones grew," Horner said. "Dinosaurs have annual growth lines and those that don't have them are simply not yet a year old."

Woodward said she conducted her research after reading a 1998 study about polar dinosaurs. Intrigued by the study, she decided to review the findings and received a National Science Foundation grant that allowed her to travel to Australia last summer, set up a histology laboratory and analyze bones in a rare collection in Australia's Melbourne Museum.

Woodward analyzed the bone tissue of 17 dinosaurs that lived 112 to 100 million years ago during the latter part of the Early Cretaceous Period. All but one of the dinosaurs in her study were plant eaters. All lived in the Antarctic Circle in what is now known as the Australian state of Victoria.

Also participating in the study were the authors of the original study: Anusuya Chinsamy at the University of Cape Town in South Africa, Tom Rich at the Melbourne Museum and Patricia Vickers-Rich at Monash University in Australia.

The three scientists who conducted the original study welcomed her analysis and didn't mind that she falsified their hypothesis, Woodward said. She added that the new study looked at more dinosaur bones than the original study because more bones from the polar dinosaurs were available. Paleontologists have been adding to the collection over the past 25 to 30 years.

The original study looked at the bone microstructure of the polar dinosaurs and concluded that the differences they saw indicated that some dinosaurs survived harsh polar conditions by hibernating, while others evolved in a way that allowed them to be active year-round, Woodward said.

The new study showed that all but the youngest dinosaurs had "Lines of Arrested Growth" or LAGs, Woodward said. Since the hibernation hypothesis was based on the presence or absence of LAGs, the new study falsified the hypothesis.

LAGSs, in a bone cross section, look like tree rings, Woodward said. Like tree rings, they are formed when growth temporarily stops.

Read more at Science Daily

Human Cells a Chimera of Ancient Life

Despite eons of mingling inside our cells, gene networks we’ve inherited from primitive, singled-celled ancestors have stayed separate. Our cells remain chimeras, a hybrid fusion of unrelated creatures.

The genes date from an event 1.5 billion years ago, when two kinds of simple cells, neither having a nucleus or cellular membrane, shacked up and created an entirely new form of life: eukaryotes.

While the two distinct communities of genes work together to keep cell machinery ticking, they otherwise stay out of each other’s hair, report biologists from the National University of Ireland.

“We humans, as part of the eukaryotes, we’re still a community of two prokaryotes,” said James McInerney, co-author of a study published in Genome Biology and Evolution, July 27.

While some scientists think prokaryotes evolved directly into eukaryotes, others think it required a merger, with two cells — one archaebacteria and one eubacteria — joining at some prehistoric point to make a cell capable of complex internal structures.

The merger led to an explosion of innovation. Suddenly cells could divide labor into ministructures, known as organelles, letting them specialize and grow larger. The extra biochemical whiz-bangery in eukaryotic cells makes lifeforms like orchids and dolphins possible.

“This idea is a hundred years old,” said McInerney. “But we wanted to ask, ‘If you have two types of organisms coming together to form a new kind of cell, do their metabolisms become completely blended together? What happens when genomes fuse?’”

To find out, McInerney and his colleague David Alvarez-Ponce surveyed the human genome and separated the genes into three groups based on taxonomic molecular signatures. One set contained genes inherited from our eubacterial ancestor, one from the archaebacterial ancestor and one held genes unique to eukaryotes. (Fingernail protein, for example, has no ancient doppelganger.)

Molecular tests showed that proteins coded by ancient parent cells still interact mostly with each other.

“They’ve found an imprint of this original symbiosis remaining after 1.5 billion years,” said Bill Martin, an endosymbiosis researcher at Heinrich-Heine-Universität Düsseldorf, in Germany and editor of the journal publishing the study. “This is a brilliant discovery. You would have thought someone would have noticed this, but nobody ever did.”

Beyond that, McInerney and Alvarez-Ponce found gene communities hold different functions. Archaebacterial genes are usually responsible for information processing, and appear to be especially important. They’ve accumulated fewer DNA mutations than eubacterial genes, suggesting that changes are more likely to have major consequences.

Eubacterial genes tended to be involved in biochemical processes. They were also more likely to be implicated in heritable human disease risk.

That more-important archaebacterial genes are found less frequently in disease might seem counterintuitive, but McInerney thinks the imbalance might exist because archaebacterial gene mutations often prevent organisms from developing at all.

Read more at Wired Science

Trickle of Salt Water -- on Mars

Summertime on Mars is bringing water to the planet's surface, suggest NASA scientists who on Wednesday unveiled pictures of slender carvings in the sun-facing sides of crater walls on Mars that are believed to be etched by flowing briny water.

"Mars is salty so any water that flows in or on the surface would be salty as well," lead researcher Alfred McEwen, with the University of Arizona's Lunar and Planetary Laboratory, told Discovery News.

Salts also would suppress the water's freezing point, making it plausible that the dark, finger-like features were carved by liquid. The streaks range from 0.5 yards to 5 yards wide and stretch hundreds of feet, far smaller than previously detected gullies. They are concentrated on rocky, equator-facing slopes.

The streaks also are highly seasonal, some growing by more than 600 feet over two Earth months, said University of Arizona researcher Lujendra Ojha, who was an undergraduate at the time and who is credited with the find.

The features appear in the late spring to early fall, suggesting a material that disappears fairly quickly is involved.

There are other explanations for the channels, which were spotted by photographed by NASA's Mars Reconnaissance Orbiter, including releases of frozen carbon dioxide, tracks from dust devils or rock slides.

But those events are not necessarily seasonal, making them less likely than water to be the proverbial smoking gun.

Laboratory tests should help determine if salty water is indeed springing out at times on Mars.

"I think it's lab experiments that are going to give us the fundamental answers we need here," McEwen said.

"Whether this is related to Mars' habitability or not," he added, "I think you'd need a lander or something to go investigate in more detail. This (discovery) provides places where there is water accessible to the surface."

The lead scientist of a proposed new mission to drill into the subsurface Martian ice said the saltwater find is interesting, but probably not applicable for a search for life on Mars.

"Water salty enough to be liquid on Mars today is too salty for life," planetary scientist Christopher McKay, with NASA's Ames Research Center in California, wrote in an email to Discovery News.

Read more at Discovery News

Where Humans Learned to Walk

A verdant expanse of grass rippling in the wind, interspersed by a few trees casting umbrellas of shade with their branches is the likely landscape over which humans and their ancestors learned to walk.

Open woodlands and savanna dominated the East African homeland of the human species as we diverged from other primates, said researchers in a recent edition of the journal Nature.

"Wherever we find human ancestors, we find evidence for open habitats similar to savannas – much more open and savanna-like than forested," said Thure Cerling, a University of Utah professor of geology, geophysics and biology, and lead author of the study, in a press release.

The researchers found that large areas of grassland and open woodland were consistently present for the past 7.4 million years. Understanding ancient vegetation patterns could help scientists resolve some questions about what kind of environment humans evolved in and the pressures that influenced development of features like our upright stance and dexterous hands.

"Currently, many scientists think that before 2 million years ago, things were forested [in East Africa] and savanna conditions have been present only for the past 2 million years," Cerling said. "This study shows that during the development of bipedalism [about 4 million years ago] open conditions were present."

"We conclude there have been open savannas all the time for which we have hominin fossils in the environments where the fossils were found during the past 4.3 million years,” which is when the first accepted ancestors of humans branched off from other primates, said Cerling.

"In some periods, it was more bushy, and other times it was less bushy," Cerling said. "Hardly anything could have been called a dense forest, but we can show some periods where certain environments were consistently more wooded than others. We find hominins (early humans, pre-humans and chimp and gorilla relatives) in both places. How early hominins partitioned their time between 'more open' and 'more closed' habitats is still an open question."

The researchers used a recently developed technique for analyzing the isotopes locked in fossilized soil to determine what kind of plants had been taking root over the years. They found that the large parts of East Africa had less than 40 percent tree cover over the past 7.4 million years.

Isotopes such as carbon-12 and carbon-13 are variations of a chemical element, in this case carbon. Because tropical grasses and sedges tend to absorb the rare isotope carbon-13, while trees, bushes, and herbs, which dominate woodlands and forests, tend to stick with the standard carbon-12 the ecologists were able to map the past landscapes based on the isotopes in the fossilized soil and current botanical knowledge.

"This study is based on the geological axiom that the present is the key to the past," said Cerling. "We assume soils in the past had similar relationships to vegetation as what we observe today."

This technique of estimating the types of plants growing in the ancient past based on the ratios of the isotopes in the soil provides “a new way to quantify the openness of tropical landscapes," Cerling added. "This is the first method to actually quantify the amount of canopy cover, which is the basis for deciding if something is savanna."

To understand what kind of landscape correlated to what carbon isotope ratio, the scientists looked at the carbon isotope ratios in 3,000 modern soil samples. The study looked at 75 tropical sites, half of which were in Africa. Satellite photos then helped the researchers determine how to classify the areas by their amount of tree cover.

The researchers defined grasslands as having less than 40 percent tree cover; woodlands as having between 40 and 80 percent; and anything with more than that as forests.

Read more at Discovery News

Aug 4, 2011

Vampire Bats Locate Blood By Finding the Heat

Vampire bats locate their blood meals with the help of three heat-sensing organs in their faces, so-called "leaf pits" surrounding their noses.

Now, new research shows the bats evolved these heat detectors by co-opting the same sensors all mammals use when something is too hot -- like a fire or boiling water -- and re-tuning them to detect body heat.

Only three other vertebrates, all snakes, are able to detect infrared radiation to seek their prey. David Julius of the University of California, San Francisco and colleagues uncovered how the snake systems work in a paper published last year.

"We wanted to ask how this same process might occur in a warm-blooded mammal," Julius told Discovery News. "There's only one that's known to do this, and that's vampire bats."

With the new study, published today in Nature,the team now knows that both the snakes (pit vipers, boas and pythons) and vampire bats have achieved this feat by modifying ion channels that open and send a nerve signal when triggered by a particular environmental stimulus.

In the case of vampire bats, they modified ion channels that typically respond to painful heat -- and which also respond to molecules in hot chili peppers and menthol in mint leaves--so that their leaf pits can detect lower temperatures, closer to body temperature, rather than the higher temperatures that cause pain.

"If you take an ion channel that's involved in sensing, say, (painful) heat and you use it to sense infrared radiation, you probably have to change the threshold quite a bit--in other words somehow change the structure of the channel so that it can sense lower temperatures and have the sensitivity to detect body heat," Julius said. "So, how does the mammal do that and maintain its ability to detect painful heat at the same time?"

The answer, it turns out, hinges on the fact that vertebrates have one set of sensory neurons for the neck and up, and another for the neck down. Vampire bats configure the neck-up receptors in the leaf pits to have a lower heat-sensing threshold, while the neck-down receptors continue business as usual, protecting the bats from dangerously hot temperatures.

The snakes' systems work similarly, Julius said, but the pit vipers (like rattlesnakes), boas and pythons derived their systems from a receptor that responds not to chili peppers and heat, but rather from a receptor that in humans responds to wasabi, which researchers believe is primarily a receptor to chemical irritants.

Read more at Discovery News

Far side of the Moon shaped by collision in space

Experts believe that the Earth originally had two moons in orbit around it, but that one was absorbed into the other when they smashed together in space as many as 4.4 billion years ago.

The theory would explain why the far side of the Moon has a thick, mountainous crust while the near side is flat – a question physicists have never been able to agree on.

It could also solve the riddle of why the side of the Moon facing Earth is rich in minerals like potassium and phosphorus, and the other side is not, researchers said.

Dr Martin Jutzi from the University of Bern in Switzerland, who led the research, said it is likely that both moons were created at the same time, when an object the size of Mars crashed into Earth and broke up.

A computer model suggests that after about 50 million years the smaller moon would have hit our Moon, which was about three times larger.

Because of the slow speed at which the collision happened, the smaller moon would have broken up and "splatted" itself against our Moon's crust in mountainous piles rather than leaving a crater.

The clouds of rock would have settled onto the far hemisphere regardless of where the impact happened because the moon is not perfectly round, according to the study published in the Nature journal.

This process, known as accretion, would have pushed the Moon's sea of magma across to the side facing Earth, helping to explain why it is richer in minerals.

Prof Erik Asphaug, of the University of California, Santa Cruz (UCSC), who co-authored the study, said: "Impact modellers try to explain everything with collisions. In this case, it requires an odd collision: being slow, it does not form a crater, but splats material onto one side."

Dr Jutzi added: "The little moon falls down on the big Moon but the speed is low because the gravity of the Moon is not too strong. Most of the small moon gets accreted, and a very small part gets re-ejected and is probably still in orbit around the moon."

Last year Prof Francis Nimmo, also of UCSC, suggested an alternate theory that tidal forces were responsible for the formation of highlands on the Moon's far hemisphere.

Read more at The Telegraph

20-million-year-old Ape Skull Unearthed in Uganda

A team of Ugandan and French paleontologists announced Tuesday they had found a 20-million-year-old ape skull in northeastern Uganda, saying it could shed light on the region's evolutionary history.

"This is the first time that the complete skull of an ape of this age has been found... it is a highly important fossil and it will certainly put Uganda on the map in terms of the scientific world," Martin Pickford, a paleontologist from the College de France in Paris, told journalists in Kampala.

The fossilised skull belonged to a male Ugandapithecus Major, a remote cousin of today's great apes which roamed the region around 20 million years ago.

The team discovered the remains on July 18 while looking for fossils in the remnants of an extinct volcano in Uganda's remote northeastern Karamoja region.

Preliminary studies of the fossil showed that the tree-climbing herbivore, roughly 10 years old when it died, had a head the size of a chimpanzee's but a brain the size of a baboon's, Pickford said.

Brigitte Senut, a professor at the Musee National d'Histoire Naturelle, said that the remains would be taken to Paris to be x-rayed and documented before being returned to Uganda.

"It will be cleaned in France, it will be prepared in France... and then in about one year's time it will be returned to the country," Senut said.

More at Discovery News

Aug 3, 2011

Scientist Converts Human Skin Cells Into Functional Brain Cells

A scientist at the Gladstone Institutes has discovered a novel way to convert human skin cells into brain cells, advancing medicine and human health by offering new hope for regenerative medicine and personalized drug discovery and development.

In a paper being published online July 28 in the scientific journal Cell Stem Cell, Sheng Ding, PhD, reveals efficient and robust methods for transforming adult skin cells into neurons that are capable of transmitting brain signals, marking one of the first documented experiments for transforming an adult human's skin cells into functioning brain cells.

"This work could have important ramifications for patients and families who suffer at the hands of neurodegenerative diseases such Alzheimer's, Parkinson's and Huntington's disease," said Lennart Mucke, MD, who directs neurological research at Gladstone. "Dr. Ding's latest research offers new hope for the process of developing medications for these diseases, as well as for the possibility of cell-replacement therapy to reduce the trauma of millions of people affected by these devastating and irreversible conditions."

The work was done in collaboration with Stuart Lipton, M.D., Ph.D., who directs the Del E. Webb Neuroscience, Aging and Stem Cell Research Center at Sanford-Burnham Medical Research Institute. Dr. Ding, one of the world's leading chemical biologists in stem-cell science, earlier this year joined Gladstone and the faculty at the University of California San Francisco (UCSF), as a professor of pharmaceutical chemistry. Gladstone, which is affiliated with UCSF, is a leading and independent biomedical-research organization that is using stem-cell research to advance its work in its three major areas of focus: cardiovascular disease, neurodegenerative disease and viral infections.

Dr. Ding's work builds on the cell-reprogramming work of another Gladstone scientist, Senior Investigator Shinya Yamanaka, MD, PhD. Dr. Yamanaka's 2006 discovery of a way to turn adult skin cells into cells that act like embryonic stem cells has radically advanced the fields of cell biology and stem-cell research.

Embryonic stem cells -- "pluripotent" cells that can develop into any type of cell in the human body -- hold tremendous promise for regenerative medicine, in which damaged organs and tissues can be replaced or repaired. Many in the science community consider the use of stem cells to be key to the future treatment and eradication of a number of diseases, including heart disease and diabetes. But the use of embryonic stem cells is controversial -- which is one reason why Dr. Yamanaka's discovery of an alternate way to obtain human stem cells, without the use of embryos, is so important.

Dr. Ding's work extends Dr. Yamanaka's by offering still another method for avoiding the use of embryonic stem cells and creating an entirely new platform for fundamental studies of human disease. Rather than using models made in yeast, flies or mice for disease research, all cell-reprogramming technology allows human brain, heart and other cells to be created from the skin cells of patients with a specific disease. The new cells created from the skin cells contain a complete set of the genes that resulted in that disease -- representing the potential of a far-superior human model for studying illnesses, drugs and other treatments. In the future, such reprogrammed skin cells could be used to test both drug safety and efficacy for an individual patient with, for example, Alzheimer's disease.

"This technology should allow us to very rapidly model neurodegenerative diseases in a dish by making nerve cells from individual patients in just a matter of days -- rather than the months required previously," said Dr. Lipton.

In the experiments being reported July 28, Dr. Ding used two genes and a microRNA to convert a skin sample from a 55-year-old woman directly into brain cells. (MicroRNAs are tiny strands of genetic material that regulate almost every process in every cell of the body.) The cells created by Dr. Ding's experiments exchanged the electrical impulses necessary for brain cells to communicate things such as thoughts and emotions. Using microRNA to reprogram cells is a safer and more efficient way than using the more common gene-modification approach. In ensuing experiments, Dr. Ding hopes to rely only on microRNAs and pharmaceutical compounds to convert skin cells to brain cells, which should lead to more efficient generation of cells for testing and regenerative purposes.

Read more at Science Daily

Colon cleansing health benefits debunked

Colon cleansing can supposedly help you lose weight, eliminate toxins and enhance well-being. But a review of scientific research shows that claims of health benefits from such procedures may be a steaming pile of nonsense.

Ranit Mishori at Georgetown University in Washington DC and colleagues reviewed 20 studies on colon cleansing published in medical literature over the past decade. The reports showed little evidence of benefit but plenty of negative side effects, including vomiting, electrolyte imbalance and kidney failure.

Mishori, a family medicine physician, has seen people who were jaundiced or dehydrated as a result of colon cleansing. As more and more of her patients inquired about the procedures for their health, she decided to look to the literature to see whether her anecdotal evidence was symptomatic of wider problems.

Sometimes called colonic irrigation or colonic hydrotherapy, colon cleansing often involves flushing the colon with a mixture of herbs and water through a tube inserted in the rectum. Over-the-counter, self-administered alternatives come in the form of laxatives, teas and capsules that can be taken by mouth or inserted in the rectum.

"The premise that you need to do something external to detoxify is wrong," Mishori says. "The body has its own mechanism to detoxify.

Shove it

David Greenwald, a gastroenterologist at Albert Einstein College of Medicine in New York City, agrees with the findings. Although colonic cleansing may sound appealing, "there is no scientific evidence that really validates that", he says.

Proponents of colon cleansing, however, believe that toxins in your gastrointestinal tract can cause a variety of health problems, such as arthritis, allergies and asthma. They say colon cleansing can help restore balance in the body.

Colon cleansing has been around since ancient times, when the procedure was thought to help the body dispose of waste and toxins. Auto-intoxication, as it was formerly called, was popular until the early 20th century, when it was discredited by professional societies, including the American Medical Association.

Read more at New Scientist

Scientists always anger those who prefer the Earth to be flat

In 1870 a biologist set out to test a popular myth. A sceptic had bet £500 that nobody could prove the Earth was anything but flat and Alfred Russel Wallace, short of cash, took him up. The experiment involved a long canal with three bridges, a marker lowered to the same height above the water from each one; and a sighting along the line which showed that the central marker appeared to be above those at each end. The Earth was curved.

Wallace gained nothing but the hatred of true believers. A hint of their response comes from a letter to his wife: "Madam – If your infernal thief of a husband is brought home some day on a hurdle, with every bone in his head smashed to pulp, you will know the reason."

Flat Earthism goes back a long way and is alive today, for one English primary-school child in five believes in it. Although all science is conditional, the evidence, most experts agree, is against it (although as recently as the 1970s enthusiasts agreed that pictures of the Earth from space proved it to be a flat disc). A subtle proof of our planet's real shape came from Isaac Newton. He was told by a sailor that his ship's pendulum clock, accurate in London, lost two minutes a day at the equator. Newton realised that – given that the rate at which it ticks turns on its distance from the Earth's centre of gravity – it swung more slowly because the globe bulged at the Equator and must hence be flattened at the poles. Time, he realised, could be transformed into space.

It still is. The Global Positioning System measures the shape of the Earth with astonishing accuracy. A receiver on the ground picks up signals from its many satellites and, by measuring the delay in receiving the signal from each one – and several can be seen at once – works out precisely where it stands. The speed of light is such that, if just a single satellite was used, an error of one millionth of a second in the receiver's clock would lead to an inaccuracy of 300 metres. However, cunning software allows the satellite clocks to check each other so that with the right instruments and with enough heavenly milestones, the position of the surface can be measured within millimetres.

The system shows how uneasy is the ground beneath our feet. The Earth's shape changes as its continental plates move, and the growing bulge as they strain against each other may soon mean that, for the first time, an earthquake can be predicted (but not, alas, a tsunami, for the GPS beam cannot penetrate water). Alarmingly, the patterns of movement suggest that an unexpectedly large seismic shock may soon be due on the eastern side of the Andes, not too far from where Wallace himself made his early collections. The system does the same for volcanic eruptions, for it reveals that volcanoes heave and sag over many centimetres as the molten rock deep below swells and shrinks. Parts of Etna, for example, are slumping at around 20cm a year, which means that it will probably not erupt any time soon. GPS shows also that volcanic islands such as Tahiti are sinking into the Earth's crust, but at no more than 5cm a century.

The technique has also been used to measure the thinning of the ice caps and the rising of the seas as the world warms. In coastal Greenland the land has risen fast over the past decade as its burden of ice has been shed. In Antarctica, too, the same is true, with a loss of ten billion tons of ice in 15 years and a rebound of the rock to match. The newly released water has contributed to the overall rise in sea level of 1.5mm a year in the five years from 2005.

Read more at The Telegraph

Aug 2, 2011

South Korean Scientists Create Glowing Dog – pics

On Wednesday, Scientists from Seoul National University in South Korea announced that they have created a glowing dog while utilising a cloning technique designed to find cures for diseases such as Alzheimer’s and Parkinson’s. Pictured is the team’s genetically modified female beagle, Tegon, which was born in 2009 and was found to glow in a fluorescent green colour while under ultraviolet light.After two years of testing, the research team has found that the glowing ability is triggered by a doxycycline antibiotic and can be turned on or off by adding or removing certain drugs to the dog’s food.

“The creation of Tegon opens new horizons since the gene injected to make the dog glow can be substituted with genes that trigger fatal human diseases,” explained lead researcher Lee Byeong-chun. He went on to state that humans and dogs have 268 common diseases, and that creating dogs with artificial symptoms could help in the treatment of these deadly diseases that affect humans.

Full story and pics at Toms Guide

Child Born with 34 Fingers and Toes Now a World Record Holder

Ten fingers. Ten toes. And another 14 tossed in for good measure. A one-year old boy in India is now a record holder as Guinness has recognized his 34 fingers and toes as the most belonging to anyone in the world.
This young man born with 34 fingers and toes set a Guinness World Record for most digits.

Akshat Saxena had seven fingers on each hand and 10 toes on each foot when he was born in India in 2010., a Guinness spokeswoman told The Huffington Post.

“I was so happy to see my baby as it was our first child,” his mother Amrita Saxena told NDTV. “But later, when I saw his fingers, I was shocked and surprised,” Doctors recently amputated the excess appendages in a series of surgeries and now Saxena has the typical five digits per limb, the Guinness spokeswoman said.

This prodigious polydactyl wasn’t born with thumbs, but doctors planned to create them with pieces of the extra fingers.

Via Hindustan Times

Aug 1, 2011

New Discoveries On Gene Regulation in the Evolution of the Vertebrate Brain

Alternative splicing of RNA transcripts is a process leading to differential gene expression and the production of different proteins, which is the key to cell differentiation and a foundation of many diseases. A group directed by Jordi García-Fernàndez and Gemma Marfany, from the Department of Genetics and the Institute of Biomedicine of the University of Barcelona (IBUB), has described the generation of a gene network regulated by the splicing factor NOVA1 during the development of the central nervous system in vertebrates.

The study, published in the journal Proceedings of the National Academy of Sciences (PNAS), is signed by the first author Manuel Irimia, and was contributed to by Amanda Denuc, Demian Burguera, Ildiko Somorjai, Jose. M. Martín-Duran and Senda Jiménez-Delgado, from the Department of Genetics of the University of Barcelona, and by other experts from the University of Vienna (Austria) and Stanford University (United States).

Over 90% of human genes, formed by introns and exons, generate multiple transcripts by a process known as alternative splicing, which facilitates the removal of introns (unexpressed fragments) and the combination of exons (expressed fragments) to form different proteins. Many hereditary genetic diseases are related to errors in the alternative splicing mechanism.

The article in PNAS focuses on the NOVA1 (neuro-oncological ventral antigen 1) protein, a splicing factor involved in the differential splicing of RNA. NOVA1 is present in all animal groups, in particular vertebrates, and regulates the production of messenger RNA with specific tissue-related functions. In the case of the central nervous system, messenger RNA encode basic proteins related to ion channels, neurotransmitter receptors, molecules involved in synapse formation, etc.

Previous studies had already confirmed the importance of NOVA1 in the architecture of the central nervous system. According to professor Jordi García-Fernàndez, "the study published in PNAS focuses principally on the generation of the NOVA1-regulated gene network and its development to full complexity in vertebrates, where NOVA1 specifically regulates tens or perhaps hundreds of genes in the central nervous system."

The study describes the stepwise assembly of the NOVA1-regulated splicing network during the evolution of metazoans. In the first step of this process, the NOVA1 protein acquired the ability to perform vertebrate-like splicing modulation, at the time of the emergence of chordates. In the second step, expression of NOVA1 became restricted to the central nervous system, just before the emergence of vertebrates. The third step saw NOVA1 acquire new exons and targets during vertebrate evolution.

The study highlights that, despite containing a large number of similar genes, the human proteome is much larger and more complex than those of invertebrates. According to the conclusions presented, regulation of splicing factors and the creation of new exons are also key processes in the assembly of specific gene networks in complex systems -- such as the human nervous system -- via differential splicing.

Determining the alternative splicing mechanism of a specific gene in a tissue-specific manner is one of the most challenging areas in current research and crucial to understanding biological complexity. Despite the importance of alternative splicing, until now no study had been made of how these tissue-specific networks emerged and evolved to reach their current level of complexity in humans. According to Gemma Marfany, "rather than a new code, we are looking at a new form of increasing gene expression complexity: each gene, in addition to carrying a "code" in its regulatory region that controls when, where and how it is expressed, also has another level -- alternative splicing -- that identifies which proteins encoded by the gene are expressed in a particular tissue or at a given moment."

More at Science Daily

Spectacular images from 'Big Bang' recreation

Bursts of heat hundreds of thousands of times more intense than the sun are generated as lead ions collide in conditions colder than outer space, releasing exotic new particles.

The reaction creates a kaleidoscope of colours as the energy of each particle is detected by recording equipment at the Large Hadron Collider (LHC) at CERN.

The base near Geneva, Switzerland, is where scientists are searching for the Higgs boson particle, an as-yet undetected form of matter which scientists hope will reveal how atoms are made up.

Another image released by CERN predicts how the Higgs boson, known as the “God” particle, might look to scientists as it decays a fraction of a second after it is created in the LHC, a 16 mile-long ring through which atoms are fired at one another.

A third picture shows trails of bubbles left behind when particles smaller than atoms travel through liquid hydrogen, taking a variety of curved paths due to the strong magnetic field around them.

Particle physicist and CERN spokesperson Christine Sutton said: "When two lead ions collide basic particles like pions – one of the basic particles that make up atoms – are expelled.

"Sub-atomic particles such as these include the basic building blocks of atoms and are common in the universe.

"So by studying these we can learn more about what the universe is made from and perhaps one day how it all began.”

Last week LHC physicists announced that they should be able to determine within 18 months whether or not the Higgs boson exists.

Although the particle itself still eludes them, experts continue to narrow down the areas in which it might be found, meaning a result may not be far off.

Researchers added that results from two of the collider’s detectors, called Atlas and CMS, might have indicated the first glimpse of the Higgs but it is too early to be sure.

More at The Telegraph

Man with roughly 50-75% of his brain missing works as civil servant, lives normal life

A man with an unusually tiny brain manages to live an entirely normal life despite his condition, which was caused by a fluid build-up in his skull.

Scans of the 44-year-old man’s brain showed that a huge fluid-filled chamber called a ventricle took up most of the room in his skull, leaving little more than a thin sheet of actual brain tissue (see image, right).

“It is hard for me [to say] exactly the percentage of reduction of the brain, since we did not use software to measure its volume. But visually, it is more than a 50% to 75% reduction,” says Lionel Feuillet, a neurologist at the Mediterranean University in Marseille, France.
Feuillet and his colleagues describe the case of this patient in The Lancet. He is a married father of two children, and works as a civil servant.

The man went to a hospital after he had mild weakness in his left leg. When Feuillet’s staff took his medical history, they learned that, as an infant, he had had a shunt inserted into his head to drain away hydrocephalus – water on the brain.

The shunt was removed when he was 14. But the researchers decided to check the condition of his brain using computed tomography (CT) scanning technology and another type of scan called magnetic resonance imaging (MRI). They were astonished to see “massive enlargement” of the lateral ventricles – usually tiny chambers that hold the cerebrospinal fluid that cushions the brain.

Intelligence tests showed the man had an IQ of 75, below the average score of 100 but not considered mentally retarded or disabled.

“The whole brain was reduced – frontal, parietal, temporal and occipital lobes – on both left and right sides. These regions control motion, sensibility, language, vision, audition, and emotional and cognitive functions,” Feuillet told New Scientist.

Full Article

Bill Gates’ advanced power reactor gets closer to reality.

Terrapower, a startup funded in part by Nathan Myhrvold and Bill Gates, is moving closer to building a new type of nuclear reactor called a traveling wave reactor that runs on an abundant form of uranium. The company sees it as a possible alternative to fusion reactors, which are also valued for their potential to produce power from a nearly inexhaustible source of fuel.

Work on Terrapower’s reactor design began in 2006. Since then, the company has changed its original design to make the reactor look more like a conventional one. The changes would make the reactor easier to engineer and build. The company has also calculated precise dimensions and performance parameters for the reactor. Terrapower expects to begin construction of a 500-megawatt demonstration plant in 2016 and start it up in 2020. It’s working with a consortium of national labs, universities, and corporations to overcome the primary technical challenge of the new reactor: developing new materials that can withstand use in the reactor core for decades at a time. It has yet to secure a site for an experimental plant and surprisingly, the funding to build it.

Full Story at Technology News

Jul 31, 2011

Great white shark leaps on board research boat

According to the Cape Times, six researchers from South Africa are reflecting on what they describe as the fright of their lives after their own close encounter with a great white shark.

The research team from Oceans Research was working off Seal Island, near Mossel Bay, on South Africa’s Cape coast, when the nearly 10-foot-long creature reportedly made its move.

Team leader Dorien Schroder told the newspaper that following more than an hour of shark activity around their boat, the Cheetah, the waters at the stern fell quiet.

“Next thing, I hear a splash and see a great white breach out of the water from one side of the boat hovering, literally, over a crew member chumming on the port side,” she reportedly said.

According to Schroder, the shark landed with half its body in the boat, but in a panic, thrashed its way further onto the vessel, cutting fuel lines and damaging equipment.

As the team scampered toward a safer portion of the boat, the shark reportedly became stuck.

Full Story at MSNBC

The mystery of the monumental post-apocolypse stones

The strangest monument in America looms over a barren knoll in northeastern Georgia. Five massive slabs of polished granite rise out of the earth in a star pattern. The rocks are each 16 feet tall, with four of them weighing more than 20 tons apiece. Together they support a 25,000-pound capstone.

Nobody knows exactly who commissioned it or why. The only clues to its origin are on a nearby plaque on the ground—which gives the dimensions and explains a series of intricate notches and holes that correspond to the movements of the sun and stars—and the “guides”, written in many different languages on each side, instruct a future society on how to conduct itself.

The story of the stones is just as strange as the monument itself. It’s since been covered in mystery and controversy. Books have been written, TV and press have swarmed to it and conspiracy theorists have pulled a mass of ideas for it’s use, from UFO landing sites to satanic cults ready to take over the world.

Wired magazine’s fascinating article writes:

The astrological specifications for the Guidestones were so complex that Fendley had to retain the services of an astronomer from the University of Georgia to help implement the design. The four outer stones were to be oriented based on the limits of the sun’s yearly migration. The center column needed two precisely calibrated features: a hole through which the North Star would be visible at all times, and a slot that was to align with the position of the rising sun during the solstices and equinoxes. The principal component of the capstone was a 7\8-inch aperture through which a beam of sunlight would pass at noon each day, shining on the center stone to indicate the day of the year.

The main feature of the monument, though, would be the 10 dictates carved into both faces of the outer stones, in eight languages: English, Spanish, Russian, Chinese, Arabic, Hebrew, Hindi, and Swahili. A mission statement of sorts (LET THESE BE GUIDESTONES TO AN AGE OF REASON) was also to be engraved on the sides of the capstone in Egyptian hieroglyphics, classical Greek, Sanskrit, and Babylonian cuneiform. The United Nations provided some of the translations (including those for the dead languages), which were stenciled onto the stones and etched with a sandblaster.

Read the full article at Weird Wired

Egyptian tomb mystery may be world's first protractor

The bizarre object to the right was found in the tomb of an ancient Egyptian architect. For over 100 years, it has languished while archaeologists debated its function.

Now, a physicist has thrown her hat into the ring, arguing that it is the world's first known protractor. The intriguing suggestion – which has drawn scepticism from archaeologists – is based on the numbers encoded within the carvings on its surface.

The architect Kha helped to build pharaohs' tombs during the 18th dynasty, around 1400 BC. His own tomb was discovered intact in 1906 by archaeologist Ernesto Schiaparelli in Deir-al-Medina, near the Valley of the Kings. Among Kha's belongings were measuring instruments including cubit rods, a levelling device that resembles a modern set square, and what appeared to be an oddly shaped empty wooden case with a hinged lid.

Schiaparelli thought this last object had held another levelling instrument. The museum in Turin, Italy, where the items are now exhibited identifies it as the case of a balancing scale.

But Amelia Sparavigna, a physicist at Turin Polytechnic, suggests that it was a different architectural tool – a protractor. The key, she says, lies in the numbers encoded in the object's ornate decoration, which resembles a compass rose with 16 evenly spaced petals surrounded by a circular zigzag with 36 corners.

Sparavigna says that if the straight bar part of the object were laid on a slope, a plumb line would revealed its inclination on the circular dial (as illustrated in this graphic).

Read more at New Scientist