Molecular decay of enamel-specific gene in toothless mammals supports theory of evolution

Biologists at the University of California, Riverside have found molecular decay of enamel-specific gene in toothless mammals, which provides fresh support for Charles Darwin's theory of evolution. The researchers were able to correlate the progressive loss of enamel in the fossil record with a simultaneous molecular decay of a gene, called the enamelin gene, which is involved in enamel formation in mammals. Enamel is the hardest substance in the vertebrate body, and most mammals have teeth capped with it. Examples exist, however, of mammals without mineralized teeth (e.g., baleen whales, anteaters, pangolins) and of mammals with teeth that lack enamel (e.g., sloths, aardvarks, and pygmy sperm whales). Further, the fossil record documents when enamel was lost in these lineages. "The fossil record is almost entirely limited to hard tissues such as bones and teeth," said Mark Springer, a professor of biology, who led the study. "Given this limitation, there are very few opportunities to examine the co-evolution of genes in the genome of living organisms and morphological features preserved in the fossil record," he added. In 2007, Springer, along with Robert Meredith and John Gatesy in the Department of Biology at UC Riverside, initiated a study of enamelless mammals in which the researchers focused on the enamelin gene. They predicted that these species would have copies of the gene that codes for the tooth-specific enamelin protein, but this gene would show evidence of molecular decay in these species. "Mammals without enamel are descended from ancestral forms that had teeth with enamel," Springer said. "We predicted that enamel-specific genes such as enamelin would show evidence in living organisms of molecular decay because these genes are vestigial and no longer necessary for survival," he added. Now, his lab has found evidence of such molecular "cavities" in the genomes of living organisms. Using modern gene sequencing technology, Meredith discovered mutations in the enamelin gene that disrupt how the enamelin protein is coded, resulting in obliteration of the genetic blueprint for the enamelin protein. Darwin argued that all organisms are descended from one or a few organisms and that natural selection drives evolutionary change. The fossil record demonstrates that the first mammals had teeth with enamel. Mammals without enamel therefore must have descended from mammals with enamel-covered teeth. "We could therefore predict that nonfunctional vestiges of the genes that code for enamel should be found in mammals that lack enamel," Springer said.

Short- and long-term memories require same gene, but in different brain circuits

Conducting experiments on fruit flies, a group of scientists have found that long-term and short-term memories are stored very differently because they depend upon the activity of a gene in different circuits of the brain. Assistant Professor Josh Dubnau, of Cold Spring Harbor Laboratory (CSHL), has ofund that both short- and long-term memories require the same gene, known as rutabaga, of which humans also have a similar version. He and his colleagues say that a rapidly occurring, short-lived trace in a group of neurons that make up a structure called the "gamma" lobe produces a short-term memory, while a slower, long-lived trace in the "alpha-beta" lobe fixes a long-term memory. During the study, the researchers placed flies in a training tube attached to an electric grid, and administered shocks through the grid right after a certain odour was piped into the tube. They observed that the flies with normal rutabaga genes learnt to associate the odour with the shock, and, if given a choice, buzzed away from the grid. On the other hand, the flies that carried a mutated version of rutabaga in their brains lacked both short- and long-term memory, did not learn the association, and failed to avoid the shocks. However, the researchers also found that total memory deficit did not occur when flies carried the mutated version in either the gamma or in the alpha-beta lobes. They said that restoring the normal rutabaga function in the gamma lobe caused the flies to regain short-term memory, but not long-term memory. Similarly, added the researchers, restoring the gene's function in the alpha-beta lobe alone restored long-term memory, but not short-term memory. "This ability to independently restore either short- or long-term memory depending on where rutabaga is expressed supports the idea that there are different anatomical and circuit requirements for different stages of memory," Dubnau said. His team will next try to determine how much cross talk, if any, is required between the two lobes for long-term memory to get consolidated, hoping that it may add to the progress that scientists have already made in treating memory deficits in humans with drugs aimed at molecular members of the rutabaga-signalling pathway to enhance its downstream effects. A research article describing the study has been published in the journal Current Biology.

Blind people may soon be using their tongues to 'see'

In a groundbreaking innovation, scientists have created an electronic device that may allow blind people to "see" using their tongues. The extraordinary technology works by taking pictures filmed by a tiny camera, and turns the information into electrical pulses, which can be felt on the tongue. Tests have shown that the nerves send messages to the brain, which turn these tingles back into pictures. The tool, called the BrainPort vision device, resembles a pair of sunglasses attached by cable to a plastic lollipop. Its users have revealed that they can make out shapes, and even read signs with fewer than 20 hours training only. The scientists behind this innovation say that learning to picture images felt on the tongue is similar to learning to ride a bike. The device, which collects visual data through a small digital video camera about 2.5cm in diameter, which sits in the middle of a pair of sunglasses worn by the user, could be available for sale later this year. The information is then transmitted to a hand-held control unit, which is about the size of a mobile phone. The unit converts the digital signal into electrical pulses and sends this to the tongue via the lollipop that sits on the tongue. The lollipop contains a grid of 600 electrodes, which pulsate according to how much light is in that area of the picture. The control unit allows users to zoom in and out and control light settings and electric shock intensity. "At first, I was amazed at what the device could do. One guy started to cry when he saw his first letter," News.com.au quoted William Seiple, research director at Lighthouse International, which has been testing it, as saying. Robert Beckman, president of US-based Wicab which is developing the BrainPort, said: "It enables blind people to gain perception of their surroundings, displayed on their tongue. They cannot necessarily read a book but they can read a sign." Beckman is hoping that the device would be used to improve people's mobility and safety.

'Telepathic' microchip can help paraplegics operate PCs, TV by thought

A British scientist has developed a "telepathic" microchip that can enable paraplegics to operate PCs and television by thought alone. Jon Spratley, 28, who works for Cornwall-based specialist engineering company 42 Technology, developed this chip while studying for a PhD at Birmingham University. He says that the chip takes advantage of the fact that even though paraplegics are unable to move their limbs, their brains still produce an electronic signal when they try. He adds that once implanted onto the surface of the brain, the chip captures this electronic "thought" and transmits it wirelessly to control a range of simple devices. He hopes that this chip may prove very help paraplegics, amputees, and those with motor neurone disease to operate light switches, PCs and even cars by the power of thought alone.pratley, from Stevenage, Hertfordshire, revealed that the main aim of his research was to "help patients communicate". "We are just trying to help people with severe communication problems or motor neurone disease - like Dr Stephen Hawking or Christopher Reeve," the Telegraph quoted him as saying. "What we have designed would allow them to control a computer with their thoughts - if they imagine their muscles moving that could flick a light switch for example," he added. Spratley, honoured with the MediMaton prize by the Institution of Mechanical Engineers, claims that implanting the chips will require minimal invasive surgery. Tests conducted in the laboratory have shown the technology to work, but human trials have not been conducted as yet.

The curious case of the 2,500-yr-old bizarre Nok people of Nigeria

A team of German archaeologists is looking for clues to explain the mysterious culture of the 2,500 years old Nok people in Nigeria. The Nok people left behind bizarre terracotta statues, broken pots, storage vessels, a clay lizard and fragments of clay faces with immense nostrils. The chipped head of a statue depicts an African man with a moustache, a fixed glare and hair piled high up on his head. He looks gloomy, almost sinister. Peter Breunig from the University of Frankfurt am Main runs an excavation near the Nigerian highlands of Jos, where the mysterious Nok culture once blossomed. Spanning more than 80,000 square kilometers (31,000 square miles), the tropical region they lived in was larger than Ireland. Its inhabitants lived in wooden huts and ate porridge made from pearl millet. Some women subjected themselves to bloody "scar ornaments" scratched into their breasts with knives. As archaeologists imagine it, smoke hung in the air as people fired masterly terracotta creations in kilns heated to 700 degrees Celsius (1,300 degrees Fahrenheit). The most astonishing fact about what Breunig calls "a society without writing" is its age. It dates from around 2,500 years ago, a time when a wave of change in belief systems washed over other continents. Nok sculptors were contemporaries of Solon, Buddha and the early Mayans. For years, people have believed that Africa was left behind at that time - but Breunig knows better. "Around 500 B.C., the population exploded," he said. People that had been living a Stone Age-like nomadic existence suddenly settled. Breunig speaks of a "cultural Big Bang." In their excavations, the team discovers shards of clay statues everywhere - on rock slopes, in ancient refuse pits and in open spaces. The largest of these impressive figures can stand up to one meter (3.3 feet) tall and resemble what might be kings or members of a social elite. Others wear horned helmets or carved-out gourds on their heads. A third of these figures are women. The clay figures are strangely uniform, almost as if they had been mass produced. The eyes are always triangular, the pupils are pierced, and the eyebrows are high and arched. They look sedate and immersed in their thoughts. Lightning-shaped tattoos adorn their cheeks.cientists are puzzled about who could have created this collection of curiosities. The German researchers have now used state-of-the-art analytical devices to examine this area. The project could finally shed some light on a phenomenon that is one of the biggest mysteries of early history.

Why is the sun hotter outside than inside?

The mystery of why temperatures in the sun's outer atmosphere soar to several million degrees, far hotter than temperatures near the sun's surface, has been solved. New observations made with instruments aboard Japan's Hinode satellite reveal the hotter outer atmosphere is due to nanoflares. Nanoflares are small, sudden bursts of heat and energy. 'They occur within tiny strands that are bundled together to form a magnetic tube called a coronal loop,' said James Klimchuk, an astrophysicist at the Goddard Space Flight Centre's Solar Physics Lab in Maryland. Coronal loops are the fundamental building blocks of the thin, translucent gas known as the sun's corona. Scientists previously thought steady heating explained the corona's million degree temperatures. Observations from the NASA-funded X-Ray Telescope (XRT) and Extreme-ultraviolet Imaging Spectrometer (EIS) instruments aboard Hinode reveal that ultra-hot plasma is widespread in solar active regions. The XRT measured plasma at 10 million degrees Kelvin, and the EIS measured plasma at five million degrees Kelvin; 273 degrees Kelvin equal zero degree Celsius. 'These temperatures can only be produced by impulsive energy bursts,' said Klimchuk, who presented the findings at the International Astronomical Union General Assembly meeting in Rio de Janeiro, Brazil.

The Cool Hand Of Technology

A young engineer slips a glove on his right hand and wiggles it around at the wrist, then curls in his fingers. A shiny, black robotic hand mounted upright on his desk whirs and clicks as it mirrors his "real" hand with rapid movements. Very cool. But ask any of the other engineers what they think this hand could be used for and they have one, enthusiastic response: "Everything." That's a problem for Shadow Robot, the tiny London company (2008 sales: 350,000 pounds or $577,000) that has been developing this robotic hand, considered one of the most dexterous in the world, for more than decade. It proudly counts NASA and the British defense department as clients, along with several universities. But the device has yet to be put to practical use or find itself a market, much less make a profit. Rich Walker, the company's 38-year-old managing director, wants to change that.

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Shadow Robot's hand is unique in its lifelike size and complexity. Its joints comprise 24 different degrees of freedom (or angles of independent movement) and are powered by "air muscles," which consist of tiny rubber tubes covered in a plastic mesh. When the tubes inflate, the mesh contracts, moving a tendon in a certain way. The technology is also easily compatible with other systems. Most other robotic hands, as developed by competitors like Barrett Technologies and Germany's Schunk Group, are simpler or larger. Barrett's hand has three fingers and is mainly used for manufacturing, while it also sells a robotic arm used for performing surgery. There are around 11 or 12 multinational companies in the world today selling 99% of the world's robotic arms, says Bill Townsend, the founder and CEO of Barrett. About 70% of them are used for making cars, and 30% are for other industrial manufacturing. But Shadow Robot's hand is so dexterous, Townsend notes, it is better suited to "emerging applications" that are more human friendly than his machines. "Emerging" describes it well. Over the course of a decade, Shadow Robot has sold about a dozen hands retailing at approximately 100,000 pounds ($165,830) each, but most of its clients have been so intrigued by its human-like qualities that they buy just to research it. NASA has been cagey about what it's doing with the hand, Walker says, but he knows the agency took it apart immediately after purchase. Britain's Ministry of Defense isn't doing such reverse surgery. It paid Shadow Robot 200,000 pounds ($331,660) to build and develop a robotic hand that could be integrated onto another robot used to defuse bombs, though it won't give the company much more information than that. This seems to be along the lines of where Walker, a Cambridge math graduate with dreadlocks down to his waist, wants to take the company: robots that can do things any human hand could, but shouldn't because it's too dangerous, including working with hazardous materials. He also imagines specialists using the hand to fix things from great distances--even many miles--with the help of a video camera. This is still years in the future, though. After a decade of struggling along with 250,000 pounds ($414,560) investment capital from founder Richard Greenhill and another director, Shadow Robot is currently at that difficult stage met by many high-tech companies, where the people behind it start to realize they cannot continue to just make cool-looking technology anymore--they have to make money too. Shadow Robot has never made a profit. Most years it has either booked a loss or broken even; it only started being funded by its own sales last year. Recently its accounts have started to show some promise. Shadow brought in revenues of 100,000 pounds ($164,880) in 2007, then 350,000 pounds ($577,089) in 2008 and is projecting sales of 700,000 pounds ($1.2 million) this year. A big chunk of that, or 200,000 pounds ($331,660), will come from the sale of a hand to Britain's Ministry of Defense, and another 150,000 pounds ($248,750) is the first installment of a four-year research contract with the European Union, via a lengthy grant application through Pierre et Marie Curie university in Paris. Shadow Robot is 50% owned by 66-year-old Greenhill, who was able to fund it until 2008 with money from a stock photography firm he started with his wife. The rest of the company is owned by its eight, full-time employees. Greenhill is the ultimate geek. He would happily continue tinkering with his robots for the remainder of his life and finds the notion of making money from them jarring and a "commercial pipe dream," according to Walker. One reason for his view may be the difficulty he had making money from robots in the past: he set up an educational robotics company in the early 1980s, which quickly folded. For many years Greenhill's anti-commercial stance bothered Walker and the company's main board member, Nick Singer, a banjo-playing design engineer who took care of about a third of Shadow's funding in the 1990s. After a number of heated discussions--"We provided hours of entertainment," Walker says of himself and Greenhill--he and Singer finally confronted the founder last year. "Greenhill didn't want to run a business. Singer and I felt that a commercial approach would enable us to get the company off the rocks financially, and Greenhill agreed to step back." The company's advisors recommended that Walker take over. It was a stark change in roles. Walker had first met Greenhill when he was just 15 and attending a summer camp devoted to computers. He became something of a protégé for the older inventor, and went on to spend his summers working with Greenhill and his small team of robot enthusiasts out of the attic of the founder's home in Islington, North London. (The company transferred to a store front just 400 yards away in 1993 after Greenhill bought the building. It remains there to this day.) While Walker has pulled away from robotics designing and started managing the office and accounts, Greenhill also pulled away geographically - he spends much of his time in the English mountains of Cumbria, hiking in remote areas with no mobile phone access. Occasionally he lends his advice to the company on research. This may be a good thing if Shadow is to succeed. "Richard is a visionary," says Walker. "And his long-term goal is building humanoid robots that will do everything." But while the protégé likes that long-term goal too, he wants to add "shorter goals and road maps and plans." With Greenhill having come up with the new ideas to prove people wrong, Walker wants to avoid reinventing the wheel. Whereas the founder avoided books, his energetic successor walks out of the library with 12 of them, all about business and marketing. "A few years ago we were focused inwards and assuming that people would find out about us. We thought that if you built a better mousetrap the world would beat a path to your door." Now Walker, a lover of metaphors, is the one knocking on doors and picking up the phone to companies or people he reads about in trade magazines. He tried hiring sales people, but found that research departments were put off by their pitches, so he stopped. Now Walker takes care of much of the selling himself, as well as of the grant applications; for three months out of the year he spends 75% of his time applying for grants. He's learned to spend as much of the rest of his time attending trade fairs, meeting potential customers, or reminding an engineer to drop a line to someone who could find their robotic hand useful. It's how they got that Ministry of Defense contract. "You sow bread on the water and eventually something bites." With the company now refocused, Walker is trying to find other markets to tap besides defense. The Defense gig has the potential to become much bigger, but until that is confirmed he's sniffing around in biomedicine, nuclear energy and hazardous waste. Gaining traction in those markets has been difficult, but Walker at least knows that Shadow Hand is a product that could one day minimize risk to humans, in war zones or with hazardous materials. More importantly, he's caught on to the basic principle behind running a business: "If you don't have somebody that's interested in what you're doing, there's not a lot of point doing it."