Posts tagged students
CU research propels “Blade Runner” to Olympics
Jul 11th
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 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.”
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.
Coming to CU: High-tech hallucinogenic "Swarm Wall"
Jun 4th
A monthlong summer exhibit at the University of Colorado Boulder Art Museum will feature a dynamic new media composition based on innovative robotics technology.
Called “Swarm Wall,” the large-scale interactive piece displays changing fields of color, light and sound that are driven by a distributed form of artificial intelligence.
As many as 70 intelligent “nodes” behind the piece create a swarming effect when they detect movement and communicate it with one another. The nodes exhibit swarm behavior because each performs actions solely based on its own plan and the actions of its immediate neighbors.
The 42-by-12-foot installation is the first product from a new art and technology research group on campus. The group was launched by faculty members Michael Theodore of the College of Music, who received a $44,000 grant from CU’s Innovative Seed Grant Program last year to support the collaboration, and Nikolaus Correll of the computer science department.
Also involved in the Swarm Wall is Ken Sugawara, a visiting computer science professor from Tohuku Gakuin University in Japan who is an expert in animal flocking behavior, the inspiration behind the patterns the wall displays.
The seed grant, which Correll and Theodore say already has helped them attract additional funding, was the first step toward establishing an active lab where students, faculty and professional researchers from various disciplines collaborate on cutting-edge applications of artificial intelligence.
“We’re now calling it the ‘if’ lab because we want to see what happens if artists put engineers in front of tough problems,” said Correll, who is providing space for the growing group within his own robotics laboratory in the Engineering Center at CU-Boulder.
“We want to assemble some basic, inexpensive tools that students can use to explore and to develop new applications of robotics,” Correll said.
Scattered around the lab last week were a collection of small custom circuit boards, electronic panels, items resembling ping pong balls and various other components that are being used to assemble robotic devices.
An assembly of circuit boards connected with bright orange cables also was mounted on a partition in the lab in preparation for the installation of Swarm Wall. Small mechanical arms or flippers waved back and forth as the “brains” behind the Swarm Wall were tested. Sometimes the movement was synchronized, while other times a ripple effect would occur in response to some stimuli.
“Artistic exploration can help computer scientists and engineers to ask questions they wouldn’t have otherwise asked,” said Theodore, who also serves as director of the ATLAS Center for Media, Arts and Performance.
“The difference between arts and science is very diffuse; both want to discover new things,” Theodore said. “The cool thing about art is that we can explore systems that are not of interest to classical funding agencies, but might be so after maturing in a lab like the ‘if’ lab.”
Swarm Wall is one of four pieces in “Michael Theodore: Field Theory,” an exhibition of kinetic sculpture, sound, lighting and works on paper, running June 15 through July 14 at the CU Art Museum. The exhibition is free and open to the public. An opening reception will be held on June 15, from 6 to 8 p.m. For additional information, visitors may call the CU Art Museum at 303-492-8300 or go to http://cuartmuseum.colorado.edu.