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Duke Research - August 2011

August 30, 2011

We've Moved ... Again!

Please stay and enjoy the posts about Duke University's research community below, but if you want to see the newer stuff, you should go here: http://sites.duke.edu/dukeresearch

The packaging has changed, but the blog is the same. We’ll be covering the people and events that capture the excitement and energy of Duke’s research environment; interesting findings, fascinating seminars, super-luminary guest speakers, amazing students. The blog is written by a team of professional journalists and curious students -- an ideal mix, we think! 

Way-Back Issues: 

We began this blog on the Google Blogger service in 2007, where it ran until May 2010. You can see that amazing collection of posts here: http://dukeresearch.blogspot.com/

Posted by klb25. 0 comments

Tags: science communication and education

Hurricane Katrina, Mary Edna Fraser.

August 26, 2011

Rushing to shore

By Ashley Yeager

Seeing the satellite images of Hurricane Irene reminded me of a piece of art I'd seen a few weeks ago. It was a stunning wax-fabric batik of Hurricane Katrina by Mary Edna Fraser.

Flipping to a print of it in Global Climate Change: A Primer, I read about a few cities that were swallowed by the sea.

Edingsville, S.C., in 1893. Broadwater, Va. in 1941.

But Diamond City, N.C., may have the best story.

After being pummeled by three successive hurricanes in the late 1800s, citizens tore down their houses, packed them on sailboats and navigated them across Back Sound to Harkers Island, where they rebuilt them.

Today, in the U.S., 53 percent of the population lives on the 19 percent of land area near the coast, according to the Primer's authors, geologist Orrin Pilkey and his son, Keith.

Imagine 165 million people tearing down their homes and moving them inland.

Posted by ay37. 0 comments

Tags: environment/sustainability

Z-prime boson

August 24, 2011

Z-prime search may hurdle Higgs hunt

By Ashley Yeager

If you're bummed about humanity's biggest accelerator not producing a Higgs particle yet, maybe the latest effort to find a Z-prime will make you feel better.

The new results can't claim a discovery of this sub-atomic particle, a gauge boson. But Duke physicist Ashutosh Kotwal says his team is narrowing in on this less press-frenzied particle, which, if discovered, means our understanding of particle physics would need a few revisions.

Physicists have been looking for Z-prime just as they have the Higgs, by slamming fast-moving particles into each other at the Large Hadron Collider, or LHC, in Europe.

Scientists are interested in predicted particles like Z-prime because they could fix holes in the current model, the Standard Model, that explains particle physics.

One of the biggest holes of the model is its inability to explain the origin of mass. The Higgs boson is supposed to correct this, but there are other problems, such as why neutrinos oscillate, why there is more matter than antimatter in the universe or where dark matter and dark energy originate.

Discovering new particles, like the Z-prime, could answer these questions, Kotwal says.

In April, scientists using Fermi Lab's Tevatron accelerator in Illinois reported possible signs of a Z-prime particle and with it, new forces of nature, but the physics community was cautious to claim discovery.

A few months later, Kotwal's team published data from LHC that did not find a Z-prime, despite working in similar energy levels as the U.S.-based accelerator.

Now, LHC is "far and away" more sensitive than the Tevatron, and by Christmas, the European collider will have produced four times more data in a range of energies and masses where Z-prime could be, Kotwal says. His team's latest LHC data has been submitted to the journal Physical Review Letters.

Kotwal adds that Z-prime particles also appear to behave similarly to gravitons, the hypothetical particles that could provide a quantum explanation for gravity. Any progress made in narrowing the mass and energy range where Z-primes sit will bring physicists closer to finding gravitons and possibly unifying the four fundamental forces of nature.

Of course, LHC has much more data to collect, and while hopes for a Higgs have been pushed back to the end of 2012, a Z-prime particle could pop into the data early next year, Kotwal says.

Posted by ay37. 2 comments

Tags: physics, research

Mohamed Noor

August 10, 2011

Managing On the Shoulders of Giants

Biologist Mohamed Noor recently shared some of his scientific wisdom and management philosophy with Duke's "Faith and Leadership" online magazine.

The magazine, a production of our Divinity School's leadership education program, thought it might be interesting to get a glimpse of teamwork and exploring difficult problems from the scientific perspective. Indeed it was.

Noor was only too happy to share. In addition to offering a seminar series called "Graduate School 101", he's currently working on a book aimed at helping graduate students figure out how to establish themselves as leaders and managers when they become faculty. He spends a lot of time thinking deeply about how and why we train scholars the way that we do and often blogs about it

Noor's thoughts on exploration. Noor's management philosophy.

 

 

Posted by klb25. 0 comments

Tags: behavior/psychology, biology, faculty, students

sea urchin larva

August 9, 2011

Baby sea urchins aren’t all the same

Guest post by Viviane Callier, Duke biology

Sea urchin embryos have a lot more variation in the genes that regulate their early development than scientists thought, a new study shows.

Because getting early development “right” is fundamental, researchers believed that organisms that deviate from the typical pattern could not survive into adulthood. They also thought there was a strong constraint on the amount of genetic variation that could exist in the genes that regulate early development.

But David Garfield, a recent graduate from biologist Greg Wray’s lab, has shown that sea urchin embryos show variable patterns of gene expression even in the earliest stages of life.  Given that this early genetic variation should be harmful to a developing sea urchin, it was a mystery why the variation was not eliminated by natural selection.

The answer, Garfield says, may lie in the nature of interactions between early developmental genes. These genes do not act in isolation. They interact, forming a network of genes that regulate each other.

Garfield’s study is the first to link a gene’s place in a developmental gene network to the consequences of variation in that gene.

To study the networks, Garfield examined the correlations between the expression of genes and that of their downstream targets.  He also studied how genetic variation was related to variation in the shapes of larval sea urchin skeletons.  

He found that in early sea urchin development, gene interactions are typically switch-like. Genes are either turned on or off.  This switch-like behavior might prevent a lot of the variation from being expressed, unless it crossed a very specific on/off genomic threshold.

These interactions, however, are in direct contrast to the interactions of genes in the mid- to late-developmental stages. In these later stages, genes respond linearly to the amount of variation, so the differences will appear in the sea urchins’ skeletons, and affect their ability to survive in the wild. 

Posted by ay37. 0 comments

Tags: biology, genetics/genomics, research, students

runners on a hill

August 1, 2011

Running from math

By Ashley Yeager

. . . 158 . . . 159 . . . 160.

In the first minute of my morning run, my feet strike the ground 160 times, 80 times each foot.

Yes, I count. But not for the whole run. I cheat and do the math.

It's pretty astounding to calculate that in a short, 30-minute jog through Duke Forest, each foot hits the dirt 2,400 times.

While that's not much that compared to the pounding American marathoner Ryan Hall or former Duke runner Bo Waggoner give their feet (and shoes), thinking about the thousands of impacts made me curious about the science that could reduce the stress on my soles.

Unfortunately, "there's a lot we don't know about how our feet strike the ground when we run," Waggoner says.

He researched the topic for his senior thesis and found that while many scientists had done experiments to test the impacts of running, few had tried to model them.

The experiments show that, even on hard surfaces, runners without shoes who hit the ground with their forefoot made smaller collision forces with the ground than shoe-clad runners landing on their heels.

But, the tests can't measure the internal impacts between bones at the ankle or knee.

"And, there are a lot of simple, unanswered questions about what physics goes on when our foot hits the ground and pushes back off, like where the force is going and coming from and why," Waggoner says.

In other words, scientists don’t really know how, mechanically, a foot strike in running actually occurs.

footstrikeDrawing of the tendons and muscles of the foot. Image courtesy of Runner's World.

To take strides in that direction, Waggoner turned human feet, ankles and legs into rods and springs. He simulated impacts between the rods and springs and a network of dots representing the ground.

Surprisingly, the "very basic" model began to show that impact forces were higher when hitting the ground with the heel. Hitting with the front of the foot created less stress.

With better models, which are "still an if at this point," scientists may learn where the stress and forces are going during different foot strike patterns and how and why runners get overuse injuries, Waggoner says.

The simulations could also alter shoe design. When Waggoner put mock shoes on his simulated feet, the sneakers with more padding at the front made less impact with the ground during a forefoot strike. Most real running shoes have more padding in the heel.

I know my shoes do, or they did, so I think the models are telling me to stay on my toes.

 

Posted by ay37. 0 comments

Tags: physics, research

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