Science&Technology
4 wednesday, january 18, 2012
Robots borrow tail design from jumping lizards
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By HUDSON LOFCHIE Aggie Science Writer
We can build it. We have the technology. Research into unmanned robotics has received ample attention lately. This is mostly due to the military’s increased use of drones to fight remotely without endangering human life. However, unmanned robots are also receiving attention from engineers who wish to use them not for waging war but for performing rescues in the aftermath of disasters. When the terrain is treacherous, the air is toxic or when hazardous chemicals pervade the environment, robots need to be able to navigate and do their job in the most effective way possible. Researchers at the UC Berkeley Center for Interdisciplinary Bioinspiration in Education and Research (CiBER) lab are working on a robotic design that uses a tail derived from lizards and dinosaurs to provide unsurpassed stability even when the robots lose their balance. “Inspiration from lizards will likely lead to far more agile search-andrescue robots,” said Robert Full, team leader and a professor of integrative biology at UC Berkeley. The research team, consisting of graduate and undergraduate students in biology and engineering, has discovered that lizards use their tails as a counterbalance to prevent them from falling head over heels when they jump. The team added a tail to a robotic car called Tailbot and found that landing safely after losing balance is strongly dependant on the angle of the tail relative to the body. The team used high-speed cameras to film lizards as they jumped. “To see whether the lizards used their tails to stabilize themselves, we had them run down a track and jump up to a wall,” said Thomas Libby, an
Jumping lizard
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integrative biology graduate student and co-author of the study. “We used a slippery patch to make them slip during the jump and if they couldn’t stabilize themselves, they would crash headfirst into the wall.” The researchers found that the lizards swung their tails up or down to keep their body perfectly oriented for an accurate landing. The swinging motion of the tail transfers angular momentum away from their body, which reduces rotation during jumps and fast movement. “It’s analogous to how a human might swing their arms when they slip on ice, but lizards are much more effective at it because their tails are so large,” Libby said. As Libby pointed out, directly copying a lizard’s tail for a mechanical design is a bad idea. The live lizard uses its tail for many functions that include maintaining balance, storing fat, communication and defense. The mechanical version will not have to satisfy all of these requirements. Their research shows that the tail from a velociraptor would have much more effective stabilizing properties, but there just is not enough data available to know if velociraptors had the same
amount of tail articulation (range of motion) that the lizards do. “The biological form is not the target. If other technologies were better we would [use them], for example, a small flywheel,” said Evan ChangSiu, a mechanical engineering graduate student on the Berkeley team. “We analyzed the trade-offs and have come to the conclusion that tails are uniquely suited to this task.” To undertake a project of this complexity and magnitude requires a remarkable level of interdisciplinary cooperation. Biologists had to work with engineers, who had to work with programmers and all of these groups had to work cohesively to make a working final product. “The interdisciplinary team was the key to the whole project,” Libby said . “Not only did the lizards inspire the robot, but the robot was then used as a physical model to shape our hypothesis for the animals.” The robots are not yet ready for large-scale use, but as researchers refine the design, the robots come closer and closer to real-life use in the field. HUDSON LOFCHIE can be reached at science@theaggie. org.
Marco Fido?
UC Davis researchers show European breeds trace back through silk trade By BRIAN RILEY Aggie Science Writer
Ben Sacks, the director of the Canid Diversity and Conservation Group in the UC Davis School of Veterinary Medicine has a dream: to take on the huge task of compiling an “atlas” of all the world’s dogs — whether wild, domestic, stray, or something inbetween — that includes information on what they eat, how they relate to humans in different cultural contexts, what they look like and other physical data. Newly published results from one project that involved Sacks, along with UC Davis post-doc researcher Sarah Brown and UC Davis School of Veterinary Medicine professor Niels Pedersen, as well as other researchers from around the world, point toward surprising conclusions in the field. After careful genetic anal-
nant, the team gets to work collecting samples of pretty much everything a child is exposed to in its first few years: blood, urine, breast milk, stool, even things like Amy dust and cleaning products. Stewart “We do a walk through which details how many TVs are in the house, and we do a dust collection for the dust in the house,” said McKenzie Oliver, the project manager of MARBLES. f the myriad childhood illnesses and dis- “We have nutrition questionnaires, environmental orders that cause anxiety history questionnaires, exto pregnant women everyposure questionnaires, so where, few are as common we get actual samples to yet mysterious as autism. analyze any self-reported According to the Centers data.” for Disease Control and The work isn’t just on the Prevention (CDC), about researchers’ end, though. one in every 150 children are born with autism; how- The mother has to fill out ever, despite decades of re- a weekly symptom diary while she is pregnant, a search, scientists are left with scant clues on the pos- monthly diary for the first sible cause or causes of this year of the baby’s life and a quarterly diary for the two disorder. years after that. A UC Davis study called The work can be taxing. Markers of Autism Risk “We have some families in Babies: Learning Early that are reSigns ally excited (MARBLES) If the answer isn’t primarily in to be part is a unique attempt to the genes, the twin studies don’t of the research and find and have much more to say will do anytest many thing to possible help us and causes and don’t think of us as a burhow they may interact to den in their life,” Oliver cause autism. said. “With other [families], Despite its common, singular name, autism is more we struggle to get them to accurately described as be- complete the questionnaires and forms and coming part of a spectrum, plete a visit.” called Autism Spectrum When the families live Disorders (ASD) that vary far away, there are othin severity. The most seer challenges. Most of the vere is Autistic Disorder, study involves home viswhat most people think of its, but they do have to visas “classic” autism. People with Autistic Disorder have it a MIND Institute clinic, which can be problematic. problems communicating “Some families already in social situations, overhave two or three kids react to minor changes in that may be in school, and routine and may develop obsessive interests or other have to drive all the way to Sacramento,” Oliver said. unusual behaviors. “It can be their whole day The most common to drive from San Jose to way to study the possiSacramento, and going to ble causes of autism (and the MIND Institute and many other conditions) is having to go back. It’s a real through twin studies. The challenge that we’re facing idea here is that the twins now.” will have the same environment and same age; the Hertz-Picciotto, the principal investigator, thinks only thing that is different between identical and fra- looking at the big picture of environmental factors is ternal twins is that identithe way to find clues. cal twins share all of their DNA. If the identical twins “Environmental factors have to be taken broadare more likely to both ly, including nutrition, mahave autism than the fraternal twins, then it makes ternal medical and obstetric [women’s reproduction] it more likely the cause of conditions (which create autism is genetic. the environment for the fe However, twin studies tus) and some chemicals in have a major weakness. If the answer isn’t primarily in household products, particularly those that disthe genes, the twin studies rupt systems crucial for fedon’t have much more to tal development,” Hertzsay. Picciotto said. “Twin studies are con Funding for the projcerned with heritability, ect comes partialwhile MARBLES is looking ly from the UC Davis for the non-heritable facMedical Investigation tors, which is everything of Neurodevelopmental except DNA,” said Irva Disorders (MIND) Institute, Hertz-Picciotto, an epidebut they also received a miologist, environmental five-year, $10 million grant chemicals expert and the from the National Institutes MARBLES study principal of Environmental Health investigator. Sciences (NIEHS). The process of look “We’re at the first five ing for these non-heritayears of the grant, so things ble factors the MARBLES are just getting started,” way means first finding Oliver said. mothers of autistic children who plan to become AMY STEWART can be reached at science@ pregnant again. When the mother does become preg- theaggie.org.
Marbles
Tails used to stabilize and maintain balance during jumps
European dogs
ysis of 642 dogs, and also some wolves, in areas as varied as Canada, Israel, Iran, China, Australia and Bali, it appears that modern European dogs stem mostly from Southeast Asian dogs that were brought to Europe as a result of the Silk Trade. This is important because it was previously believed that European
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dogs descended mostly from Middle Eastern dogs, which in turn descended mostly from Southeast Asian dogs. Now there appears to be very little genealogical linkage between modern European dogs and modern Middle Eastern dogs. “This was kind of a surprise,” Sacks said. “It’s not what we did the study to
look for.” One of the main purposes of the study was to find out if modern Middle Eastern dogs and modern Southeast Asian dogs are indigenous, meaning they descend from long lineages of dogs in their respective areas. The study supports this conclusion. Another important ramification of the new study is that now, Europe is once again a candidate for the ultimate historical origins of the world’s domesticated dogs. According to Sacks and Pedersen, there could have been multiple domestication events in Eurasia. “Europe is back in the game,” Sacks said. Sacks and Brown are also working with UC Davis anthropology professor Christyann Darwent in a project involving the genetic study of Arctic dogs and their relationship
See DOGS, page 2
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