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Chemistry’s Sumerlin named 2010-2012 Alfred P. Sloan Research Fellow

Brent Sumerlin, associate professor of Chemistry in SMU’s Dedman College, has been named a 2010-2012 Alfred P. Sloan Research Fellow. This exceptionally competitive award will provide Sumerlin a grant of $50,000 over two years to support his research, some of which could lead to the use of nano-scale polymer particles to automatically deliver insulin to diabetics.

Click here for a video of Sumerlin and graduate student Jennifer Cambre talking about Sumerlin’s research.

The Sloan Research Fellowships are designed to stimulate fundamental research by early-career scientists and scholars of outstanding promise. These two-year fellowships are awarded yearly to 118 researchers in recognition of distinguished performance and unique potential to make substantial contributions to their field.

The fellowship places Sumerlin in the company of some of the most distinguished scientists in the country. Thirty-eight Sloan fellows have been awarded the Nobel Prize in their respective fields since the fellowships were established in 1955.

Click to read the full story

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Culture, Society & Family Economics & Statistics Health & Medicine

Human running speed of 35-40 mph may be biologically possible

2009_Evans_Amber%2Csmall.jpg

Jamaican sprinter Usain Bolt‘s record-setting performances have unleashed a wave of interest in the ultimate limits to human running speed. A new study published Jan. 21 in the Journal of Applied Physiology offers intriguing insights into the biology and perhaps even the future of human running speed.

The newly published evidence identifies the critical variable imposing the biological limit to running speed, and offers an enticing view of how the biological limits might be pushed back beyond the nearly 28 miles per hour speeds achieved by Bolt to speeds of perhaps 35 or even 40 miles per hour.

The new paper, “The biological limits to running speed are imposed from the ground up,” was authored by Peter Weyand of Southern Methodist University; Rosalind Sandell and Danille Prime, both formerly of Rice University; and Matthew Bundle of the University of Wyoming.

“The prevailing view that speed is limited by the force with which the limbs can strike the running surface is an eminently reasonable one,” said Weyand, associate professor of applied physiology and biomechanics at SMU in Dallas.

“If one considers that elite sprinters can apply peak forces of 800 to 1,000 pounds with a single limb during each sprinting step, it’s easy to believe that runners are probably operating at or near the force limits of their muscles and limbs,” he said. “However, our new data clearly show that this is not the case. Despite how large the running forces can be, we found that the limbs are capable of applying much greater ground forces than those present during top-speed forward running.”

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SMU sprinter Ebony Cuington. Photo: SMU Athletics

In contrast to a force limit, what the researchers found was that the critical biological limit is imposed by time — specifically, the very brief periods of time available to apply force to the ground while sprinting.

In elite sprinters, foot-ground contact times are less than one-tenth of one second, and peak ground forces occur within less than one-twentieth of one second of the first instant of foot-ground contact.

The researchers took advantage of several experimental tools to arrive at the new conclusions. They used a high-speed treadmill capable of attaining speeds greater than 40 miles per hour and of acquiring precise measurements of the forces applied to the surface with each footfall. They also had subjects’ perform at high speeds in different gaits. In addition to completing traditional top-speed forward running tests, subjects hopped on one leg and ran backward to their fastest possible speeds on the treadmill.

The unconventional tests were strategically selected to test the prevailing beliefs about mechanical factors that limit human running speeds — specifically, the idea that the speed limit is imposed by how forcefully a runner’s limbs can strike the ground.

However, the researchers found that the ground forces applied while hopping on one leg at top speed exceeded those applied during top-speed forward running by 30 percent or more, and that the forces generated by the active muscles within the limb were roughly 1.5 to 2 times greater in the one-legged hopping gait.

The time limit conclusion was supported by the agreement of the minimum foot-ground contact times observed during top-speed backward and forward running. Although top backward vs. forward speeds were substantially slower, as expected, the minimum periods of foot-ground contact at top backward and forward speeds were essentially identical.

According to Matthew Bundle, an assistant professor of biomechanics at the University of Wyoming, “The very close agreement in the briefest periods of foot-ground contact at top speed in these two very different gaits points to a biological limit on how quickly the active muscle fibers can generate the forces necessary to get the runner back up off the ground during each step.”

The researchers said the new work shows that running speed limits are set by the contractile speed limits of the muscle fibers themselves, with fiber contractile speeds setting the limit on how quickly the runner’s limb can apply force to the running surface.

The established relationship between ground forces and speed allowed the researchers to calculate how much additional speed the hopping forces would provide if they were utilized during running.

“Our simple projections indicate that muscle contractile speeds that would allow for maximal or near-maximal forces would permit running speeds of 35 to 40 miles per hour and conceivably faster,” Bundle said.

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Economics & Statistics Health & Medicine Researcher news SMU In The News

Appendicitis linked to flu-like virus outbreaks

askexpert.jpgThe research of SMU faculty Thomas B. Fomby and Wayne A. Woodward has been published in the January issue of the journal Archives of Surgery. Fomby is a professor and chairman of the Department of Economics and Woodward is a professor in the Department of Statistical Science.

The research described in the article “Association of Viral Infection and Appendicitis” looks at the relationship between appendicitis and seasonal viral infections. The scientists reviewed 36 years of hospital discharge data and concluded there is a relationship to a flu-like virus.

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The appendix is a fingerlike pouch attached to the large intestine in the lower right area of the abdomen. IMAGE: NDDIC

Fomby and Woodward collaborated with researchers from UT Southwestern Medical Center in Dallas and the VA Medical Center in Gainesville, Florida.

Articles about the results of the research have been widely published on many science and research news sites, including Daily Mail Online, USA Today, Business Week, Science Daily, Physorg.com, Health News Digest, BioScience Technology, Newswise and many others.

EXCERPT:

Appendicitis may be triggered by a viral infection

By JENNY HOPE
Daily Mail Online
A viral infection could explain why appendicitis appears more common in certain years and during the summer.

A flu-like virus could be the hidden cause of appendicitis, scientists claim.

Although one in ten of us will experience the condition — in which the appendix becomes dangerously inflamed — doctors have always been baffled by what triggers it.

A viral cause would fit in with another of the researchers’ findings — that appendicitis appears to be more common in certain years and during the summer.

The illness occurs when the appendix, a worm-like cul-de-sac connected to the colon on the right side of the body, becomes inflamed.

A perforated appendix that has swollen and burst is life-threatening because the abdomen is filled with infected material. In fact, appendicitis is the most common reason for emergency surgery.

In the latest study, researchers examined American hospital admissions for appendicitis, influenza and gastric viral infections over 36 years.

Their analysis showed appendicitis peaked in the years 1977, 1981, 1984, 1987, 1994 and 1998.

That clustering pattern suggested outbreaks were typical of viral infections.

Seasonal trends were also uncovered, showing a slight increase in the number of appendicitis cases over the summer months.

Read the full story.

Related links:
Appendicitis
Thomas B. Fomby home page
Wayne A. Woodward home page
Science Daily: Appendicitis May Be Related to Viral Infections
Archives of Surgery: Association of Viral Infection and Appendicitis

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Health & Medicine Researcher news Technology

Researchers: Pistorius’ artificial limbs give him clear, major advantage

The artificial lower limbs of double-amputee Olympic hopeful Oscar Pistorius give him a clear and major advantage over his competition, taking 10 seconds or more off what his 400-meter race time would be if his prosthesis behaved like intact limbs.

That’s the conclusion — released to the public for the first time — of human performance experts Peter Weyand of Southern Methodist University and Matthew Bundle of the University of Wyoming.

The Weyand-Bundle conclusion is part of a written Point-Counterpoint style debate published Nov. 19 online in the “Journal of Applied Physiology.” Weyand and Bundle were the first two authors of the study publishing the test results acquired as part of the legal appeal process undertaken after the governing body of Track and Field — the International Association of Athletics Federations (IAAF) — banned Pistorius from able-bodied track competitions, including the Olympics.

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SMU’s Peter Weyand and Oscar Pistorius during testing. Marquee photo and inside photos: By Jeff Fitlow/Rice University

In banning Pistorius, the IAAF had concluded on the basis of other data that Pistorius’ J-shaped, artificial lower limbs, called “Cheetahs” by the manufacturer, gave him a competitive advantage over able-bodied competitors. But the ban subsequently was overturned on appeal to the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland.

The case has been considered groundbreaking for the eligibility of disabled athletes and the regulation of prosthetic technology in sport. Pistorius hopes to qualify for the 2012 Olympics.

The newly released conclusion from Weyand and Bundle analyzes the scientific evidence and quantifies the competitive advantage provided by Pistorius’ “Cheetah” limbs.

Weyand says: “Pistorius’ sprinting mechanics are anomalous, advantageous and directly attributable to how much lighter and springier his artificial limbs are. The blades enhance sprint running speeds by 15-30 percent.”

Below the knee, Pistorius’ limbs weigh less than half as much as the limbs of an able-bodied male sprinter.

Bundle notes that most of the 15-30 percent speed advantage enjoyed by Pistorius is explained by how quickly the lightweight blades allow him to reposition his limbs: “Even in comparison to those male sprinters with the most extreme adaptations for speed in recorded human history, Oscar Pistorius has limb repositioning times that are literally off the charts. Usain Bolt is considered somewhat freakish because he outruns his opponents by 2-4 percent. At top speed, Oscar Pistorius repositions his limbs 15 percent more rapidly than six of the most recent world record holders in the 100 meter dash, including Usain Bolt.”

In the aftermath of the IAAF eligibility controversy, both Weyand and Bundle agreed that the initial ban was not scientifically supported and that the May 2008 ruling of the CAS to overturn the ban was sound on the basis of the incomplete evidence considered.
Pistorius’ case was successfully presented by the law firm Dewey & LeBoeuf of New York.
“We are pleased to finally be able to go public with conclusions that the publishing process has required us to keep confidential until now. We recognized that the blades provide a major advantage as soon as we analyzed the critical data more than a year and a half ago,” said Weyand and Bundle in a statement.
Speaking for both investigators, Weyand said: “We admire the unique athletic achievements of Oscar Pistorius and are grateful for his willingness to share these important results for the general benefit of athletes and athletics.”
A different interpretation of the Pistorius data appeared as part of the written Point-Counterpoint style debate in the “Journal of Applied Physiology.”
Weyand and Bundle based their conclusions on data indicating:
Pistorius’ lightweight blades allow him to reposition his limbs 15.7 percent more rapidly than five of the most recent former world-record holders in the 100-meter dash.
The springy, lightweight blades allow Pistorius to attain the same sprinting speeds while applying 20 percent less ground force than intact-limb runners.
The springy blades reduce the muscle forces Pistorius requires for sprinting to less than half of intact-limb levels.
Peter Weyand is an associate professor of applied physiology and biomechanics in SMU’s Annette Caldwell Simmons School of Education & Human Development.
Matthew Bundle is an assistant professor of biomechanics in the College of Health Sciences at the University of Wyoming.
Read news coverage of this story.
Related links:
JAP: Point-Counterpoint “Artificial limbs do/do not make artificial running speeds possible” target=blank
JAP Study: The fastest runner on artificial legs: Different limbs, similar function?
Science Daily: Oscar Pistorius, amputee sprinter runs differently
New York Times: An amputee advantage?
Times: Oscar Pistorius to make run at London 2012
Study revives Olympic prospects for amputee sprinter
T.O. Sports: Blade runner beats the ban and his ‘Cheetahs’ are no longer ‘cheating’
AFP: ‘Bladerunner’ Pistorius wins appeal against Olympic ban
IAAF: Pistorius is eligible for IAAF competition
New York Times: Amputee ineligible for Olympic events
TIME Magazine: How Fast Can Humans Go?
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Health & Medicine Researcher news

Christian Science Monitor: Usain Bolt and limits of human speed

The Christian Science Monitor asked human locomotion expert Peter Weyand to weigh in on the subject of how fast human beings might ultimately be able to run. Weyand’s analysis was published as an opinion essay in the newspaper’s Sept. 4 online version.

Earlier Weyand was interviewed by the online magazine Matador Sports for the piece “Calculating the Human Speed Limit,” which published Aug. 21, 2009; and by Britain’s Daily Express, which published “How Fast Can a Bolt of Lightning Travel?” in its July 26, 2009 edition. Weyand was also quoted by the blog SBS.com.au in a story July 22, 2009.

Weyand, a physiologist and biomechanist, is an SMU associate professor of applied physiology and biomechanics in the Annette Caldwell Simmons School of Education & Human Development. He recently lead a team of experts in biomechanics and physiology that conducted experiments on Oscar Pistorius. The South African bilateral amputee track athlete, Pistorius has made world headlines trying to qualify for races against runners with intact limbs, including the Olympics.

Excerpt:

By Peter Weyand
For The Christian Science Monitor
DALLAS — How fast might human beings ultimately run?

Usain Bolt’s recent assault on the track and field record book — running 9.58 in the 100m and reaching a top speed of nearly 28 mph — has raised this question at a crucial crossroads for organized athletics. While specific predictions by modern science are not precise, the general influence of scientific advancement is poised to overwhelm human performance and organized athletics as we have known them.

Although we can readily quantify the forces acting on the body and predict the motion they produce using classical Newtonian mechanics, we still have an incomplete understanding of the process of force production within the body, and how the body’s internal forces eventually translate into motion.

Conceivably, the secret to blazing running speeds might be explained by either of two abilities: repositioning the limbs quickly through the air, or hitting the ground forcefully with each step. Contrary to intuition, fast runners achieve their greater speeds, not by repositioning their legs any more rapidly, but rather by hitting the ground with greater force and quickness than slower runners do.

How hard and how quickly do elite sprinters hit the ground? Once up to speed, an athlete like Usain Bolt will hit the ground with a force equivalent to roughly 1,000 pounds, and do so within five 100ths of a second of the first instant of foot-ground contact.

Read the full essay.

Related links:
Peter Weyand
Annette Caldwell Simmons School of Education & Human Development