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CU research propels “Blade Runner” to Olympics
Jul 11th
University of Colorado Boulder researchers will be watching closely when South African bilateral leg amputee and sprinter Oscar Pistorius, dubbed “The Blade Runner,” makes his way to the starting block for the 400-meter sprint in the 2012 London Olympics.
Professors Rodger Kram and Alena Grabowski of the integrative physiology department have been involved in several studies analyzing the performance of amputee athletes, including Pistorius, who use blade-like, carbon fiber leg prostheses in track events. In 2007, Pistorius was barred from international competition by officials from the International Association of Athletics Federations, or IAAF, who ruled his Cheetah Flex-Foot leg prostheses conferred him an advantage over other runners.
Barred from competition, then exonerated
The decision was based in large part on a German study commissioned by the IAAF. However, data presented in April 2008 by a team that included Kram and Grabowski to the Court of Arbitration for Sport in Lausanne, Switzerland — an international group set up to settle disputes in sports — showed Pistorius gained no physiological advantage from the Cheetah prostheses over competitors. The team’s evidence and testimony played a key role in overturning the decision, allowing Pistorius to compete in able-bodied events.
The Blade Runner good to go
“The methodology of the German study that involved measuring Oscar’s oxygen consumption while running was flawed,” said Kram, who has been measuring the oxygen consumption of runners since 1983. “When we had a chance to properly measure Oscar we found that while he is quite economical in oxygen consumption compared to your average Joe, his values are well within what would be expected for a high-caliber athlete.”
At the arbitration hearings in Switzerland, Kram also argued that if a prosthetic device provides a mechanical advantage, it would very likely provide an energetic or physiological advantage. “Since there is no energetic advantage, it infers that the prostheses do not provide a mechanical advantage either,” said Kram.
Another chance
Although Pistorius subsequently failed to make the 2008 Olympic team, he was selected by South Africa’s Olympic Committee last week to run in both the individual 400 meters and a leg of the 4×400 meter relay in the 2012 Olympic Games in London, which begin on July 27. “I was delighted that Oscar was selected,” said Kram. “I was sure he’d be named to the 4×400 meter relay, but being named to the 400-meter individual event was a surprise.”
Since 2008, the research team involving CU-Boulder has continued its studies. In a 2010 study led by Grabowski, researchers used force-measuring treadmills to analyze the biomechanics of unilateral amputees — those with one amputated leg — over a wide range of running speeds. The team found the force produced by the prosthetic, carbon fiber leg was 9 percent less than that of the unaffected leg. “Applying force to the ground is crucial in sprinting events,” said Grabowski.
“We inferred that running-specific prostheses impair force generation and likely limit top sprinting speed,” said Grabowski, who received her doctorate under Kram in 2008 and recently returned to CU-Boulder as a research faculty member after doing postdoctoral work at the Massachusetts Institute of Technology. Other authors on the 2010 paper included Kram, Craig McGowan of the University of Idaho, William McDermott of the Orthopedic Specialty Hospital in Murray, Utah, and Hugh Herr of MIT.
In a 2012 paper by the same group and led by McGowan, the leg stiffness of Paralympic sprinters with both unilateral and bilateral leg amputations was compared to non-amputee sprinters across a range of speeds. The team found leg stiffness remained constant or increased with speed in non-amputees but decreased in sprinting amputees.
“During running, the leg behaves much like a spring, and the stiffness of the leg greatly influences the overall mechanics of the runner,” said Grabowski. “The study indicates that the prosthetic device limits the ability of a sprinter to change their leg stiffness during running.” In the future, she said, researchers may be able to design a prosthetic device with “adaptive stiffness” that would more accurately emulate the mechanics of a biological ankle during sprinting.
Research fueled by veterans needs
Grabowski, whose work is funded by the Veterans Administration, is particularly interested in designing better prosthetic ankle devices for military veterans or those on active duty who have undergone amputations. In collaboration with the Denver Department of Veterans Affairs, Grabowski is beginning a research effort to further develop battery-powered ankle-foot prostheses for walking and running. Such prostheses have the potential to restore mobility to users similar to the mobility they had prior to amputation, she said.
The research team is interested in locating potential test subjects in the Denver-Boulder area with leg amputations to participate in lab studies. “CU-Boulder is actively pursuing research that aims to improve the lives of amputees, particularly veterans and current military personnel,” she said. Potential study candidates can contact Grabowski at Alena.Grabowski@colorado.edu.
Research in Kram’s Locomotion Laboratory on the CU-Boulder campus goes far beyond athletics. Collaborating faculty and students are targeting the energetic costs of walking, including uphill and downhill walking in older adults; the energetics of passive cycling to treat and prevent obesity and heart disease; and studies on animal locomotion, including kangaroos, tortoises and elephants.
For more information on the CU-Boulder Locomotion Laboratory visit http://www.colorado.edu/intphys/research/locomotion.html. For more information on CU’s integrative physiology department visithttp://www.colorado.edu/intphys/.
CU team helps find the “God” particle
Jul 5th
Multinational team searching for answers about dark matter, dark energy, gravity and the fundamental laws of physics.
An international team including University of Colorado Boulder researchers has found the first direct evidence for a new particle that likely is the long sought-after Higgs boson, believed to endow the universe with mass.
Comprised of thousands of scientists, students and support staff working at the European Organization for Nuclear Research, or CERN, the team has been conducting experiments at a facility known as the Large Hadron Collider, a $10 billion, 17-mile underground loop below the Swiss-French border in Geneva that is the world’s most powerful atom smasher. Scientists have been using the LHC to attempt to recreate conditions immediately following the Big Bang by smashing protons together, searching for answers about dark matter, dark energy, gravity and the fundamental laws of physics.
Higgs boson particle thought to give other particles their mass
A huge target of the LHC effort has involved looking for evidence of the elusive Higgs boson, a theoretical elementary particle that has been predicted by physicists. Thought to give other elementary particles their mass, the Higgs boson is the only particle predicted by the Standard Model of particle physics — a scientific theory of how the universe works at the simplest level — that has not been directly detected.
The CERN team is reporting evidence today of an anomalous “bump” in a particular search region of the energy spectrum targeted by the scientists that has a mass of about 125 billion electronic volts, or 125 GeV, said CU-Boulder physics Professor John Cumalat. The research team designed their searches around the theoretical expectations for the decay of the Standard Model Higgs boson particle, he said.
“What we have found is incontrovertible evidence for a new particle at around 125 GeV,” Cumalat said. “To prove it is the Standard Model Higgs particle we will need to carefully measure the new particle’s properties, but with more data these properties can be determined.”
Inside the Large Hadron Collider
The CU-Boulder high-energy physics team, which includes 15 faculty and students, is involved with the Compact Muon Solenoid, or CMS, one of two massive particle detectors in the LHC and which weighs more than 12,500 tons. The CU team helped design and build the CMS forward pixel detectors — the “eyes” of the device — that help researchers measure the direction and momentum of subatomic particles following collisions, providing clues to their origin and structure.
CU-Boulder Professor William Ford said there were strong hints of the existence of the Higgs boson particle during the CMS particle collisions in 2011. “Now, with the new data looking so similar, it’s hard not to be a believer,” he said. The CERN team hopes to accumulate about four times as much data as they have now on the Higgs boson search project by the end of the year, according to Ford.
“God particle” would being mass and order to the universe
While the Higgs boson was nicknamed “The God Particle” by physicist and Nobel laureate Leon Lederman because its existence would bring mass and order to the universe — a nickname that has been seized on by the media — it is a term physicists do not particularly care for because of its connotations, said Cumalat.
The existence of the Higgs boson theory is crucial to helping to explain the underpinnings of the universe by confirming the Standard Model of physics that explains why fundamental particles — the building blocks of the universe — have mass. Mass is a trait that combines with gravity to give an object weight. Without Higgs boson, there could be no galaxies, stars, planets or people, say researchers.
“It is a very exciting time to be in particle physics and to be involved in an experiment unlocking the meaning of mass,” said CU-Boulder doctoral student Brian Drell.
In addition to Cumalat, Ford and Drell, there are 12 other CU-Boulder people involved in the project: faculty members Uriel Nauenberg, Jim Smith, and Steve Wagner; postdoctoral researchers Alessandro Gaz, Eduardo Luiggi, Keith Ulmer, and Shilei Zang; graduate students Bernadette Heyburn, Andrew Johnson and Troy Mulholland; and technical staff members Eric Erdos and Douglas Johnson.
Sixteen years in the making, the $3.8 billion LHC project involves an estimated 10,000 people and staff from 60 countries, including more than 1,700 scientists, engineers, students and technicians from 94 American universities and laboratories supported by the U.S. Department of Energy’s Office of Science and the National Science Foundation. The United States is providing about $530 million, primarily for the LHC detectors.
CU researchers plotting the "Map of Life
May 22nd
Effort could be a key to preserving rare species
A research team involving Yale University and the University of Colorado Boulder has developed a first public demonstration version of its “Map of Life,” an ambitious Web-based endeavor designed to show the distribution of all living plants and animals on the planet.
The demonstration version allows anyone with an Internet connection to map the known global distribution of almost 25,000 species of terrestrial vertebrate animals, including mammals, birds, amphibians, reptiles and North American freshwater fish. The database, which continues to expand, already contains hundreds of millions of records on the abundance and distribution of the planet’s diverse flora and fauna.
“We are taking 200 years of different types of knowledge coming from different sources, all documenting the locations of species around the world and compiling them in a way that will greatly enhance our knowledge of biodiversity,” said CU-Boulder Associate Professor Robert Guralnick of the ecology and evolutionary biology department, part of the Map of Life research team. “Such information could be used by any organization that needs to make informed decisions regarding land management, health, conservation and climate change.”
The initial version of the map tool being released today is intended to introduce it to the broader public, according to the researchers. It allows users to see several levels of detail for a given species — at its broadest, the type of environment it lives in, and at its finest, specific locations where the species’ presence has been documented. One function allows users to click a point on the map and generate a list of vertebrate species in the surrounding area. More functions will be added over time, according to the team.
The bryozoa fish are found in the Connecticut River
“It is the where and the when of a species,” said Walter Jetz, associate professor of ecology and evolutionary biology at Yale and the project lead. “It puts at your fingertips the geographic diversity of life. Ultimately, the hope is for this literally to include hundreds of thousands of animal and plant species and show how much or indeed how little we know of their whereabouts.”
A paper by Jetz, Guralnick and Jana McPherson of the Calgary Zoological Society describing the evolving Map of Life technology tool appeared in a recent issue of the journal Trends in Ecology and Evolution.
By highlighting the known abundance and distribution of species, the researchers hope to identify and fill knowledge gaps and also offer a tool for detecting change over time. They expect the map tool will prove useful for professional scientists, wildlife and land managers, conservation organizations and the general public.
The team is using information gleaned from a wide variety of sources, including field guides, museum collections and wildlife checklists that involved scientists, conservation organizations and “citizen scientists.” The project’s success will depend on participation by other scientists and informed amateurs, and subsequent versions of the mapping tool will offer mechanisms for users to supply new or missing information about the distribution and abundance of particular species.
Snow Leopards of Tibet are nearly extinct
Jetz called the Map of Life “an infrastructure, something to help us all collaborate, improve, share and understand the still extremely limited geographic knowledge about biodiversity.” The team continues to work on several other tasks and challenges, including who will be contributing data and how information supplied by the contributors will be verified and curated.
“A small but powerful next step is to provide a means for anyone, anywhere on the globe to use their mobile devices to instantly pull up animal and plant distributions and even get a realistic assessment on the odds of encountering a particular species of wildlife,” said Guralnick, who also is the curator of invertebrate zoology at the University of Colorado Museum of Natural History.
Guralnick said the Map of Life project is following in the footsteps of other knowledge repositories like the GenBank project, a National Institutes of Health-funded effort with a public database of more than 135 million gene sequences from more than 300,000 organisms that allows users to explore genes and genomes using bioinformatics tools. In the biodiversity arena, the Global Biodiversity Information Facility in Copenhagen has developed an important resource that provides access to more than 300 million records of plant and animal occurrences, which is one of the distributional databases being used by the Map of Life team.
The National Science Foundation has provided initial support for the Map of Life project. Other supporters are the Encyclopedia of Life; the International Union for the Conservation of Nature; and the Senckenberg Research Institute and Natural History Museum, and the Biodiversity and Climate Research Center, both in Germany.
The public demonstration version of Map of Life can be found at http://www.mappinglife.org/ and more information about the project is available at http://www.mappinglife.org/about.
