E6
KLMNO
URBAN JUNGLE
The changing natural world at our doorsteps
Flying with a single wing
W
rry the tre
In late April, the ground becomes littered with samaras, the winged seeds of maple trees. With the right wind, the single-winged “whirlybirds” can carry the tree’s embryos more than a mile.
As illustrated at right, the leading edge of the seed’s wing creates a horizontal
his creat
tornado-like vortex above the wing surface. This creates a low-pressure area that
sucks the wing upward. The mechanism was first described in
scientists led by Da
the leading edge of the see above the win
Watch a slow-motion video of the phenomenon at ht
avid Lentink at Wageningen University in the Nether tion video of the phenomenon at http://bit.ly/cKb60b.
agenin
.ly cKb60b
Seed Leading
Lead edge
Direction of
sama
ara
ra’s spin
as first described in 2009 by a team of niversity in the Netherlands.
Silver maple samara . . .
a . . .
Seed Wing
. . . in flight . . in fl
Air vortex Wing
TUESDAY, APRIL 27, 2010
Devil maple samara
Devil maple samara
ed by the devil maple samara. With a wing about ee inches long, the tiny flier weighs less than two nickels do. A propeller spins the flyer around at 10 to 16
revolutions per second. In flight, the
The RoboSeed Nano, left
inspired by the devil maple s three inches long, the tiny flier w nickels do. A propeller spins the fly
FROM ROBOSEED.COM
FROM ROBOSEED.COM
, the RoboSeed is much more
stable and easier to control than are stable and easier to control than are micro-helicopters.
Evan Ulrich has been developing th
after he began graduate studies a
Aerospace E
FROM DAVID LENTINK
Two revolutions of a twirling maple samara, illuminated by a strobe light.
Watch a video detailing the dev
ht
.ly/bLq5y3
SOURCES: Evan Ulrich; David Lentink, “Leading-edge vortices elevate lift of autorotating plant seeds,” Science, 2009
es
PATTERSON CLARK/TH
tment. g the aircraft since 2006, a year
after he began graduate studies at University of Maryland’s
Aerospace Engineering Departm
Watch a video detailing the development of the aircraft at
http://bit.ly/bLq5y3.
PATTERSON CLARK/THE WASHINGTON POST
clarkp@washpost.com
, left, is a micro-aircraft
QUESTIONS IN CANCER TREATMENT
New research hints at changes in care
“A trial like this is unprecedent-
Bloomberg News
The American Association for Cancer Research held its annual meeting April 17-21 in Washing- ton. Thousands of participants were able to consider more than 6,000 papers and short talks, and several hundred longer presenta- tions. Some highlights follow.
Matching drug with tumor
JOEL RICHARDSON FOR THE WASHINGTON POST
Rebounding from breast cancer
Basketball is not just a game
for Lynn Grodzki, above, and her teammates; it is a metaphor for — and a pathway to — survival. As participants in Healing With Basketball, a free monthly clinic for breast cancer survivors, these women build strength, flexibility, confidence and social support vi- tal to their recovery. “Research shows that continu-
ous, vigorous exercise can reduce breast cancer recurrence by up
to 50 percent; however, only two- thirds of survivors engage in the recommended amount of physi- cal activity,” says Grodzki, a psy- chotherapist and founder of the program. “We really do this to give survivors a supportive and fun environment to get active.” Each clinic begins with goal-
setting and challenge-sharing, and ends with a flurry of hugs and “great jobs.” In between, the women are subject to the chal-
lenging drills of personal trainer Andrew Weiss. A pilot program under evalua- tion for wider use, Healing With Basketball is run by George Washington University’s cancer institute. With support from the Eaglebank Foundation and the GWU Women’s Athletic Depart- ment, the clinics are offered free to Washington area breast can- cer survivors. For more information, go to
www.gwumc.edu/gwci/healing withbasketball.html. —Anna Miller
Lung cancer patients given drugs such as Tarceva and Nexa- var fare better when their tumors are first tested for certain genetic traits and then matched with the corresponding treatment, a study found. The drugs, called targeted ther- apies because they home in on specific biological pathways in- volved in tumor growth, were studied by researchers at the Uni- versity of Texas M.D. Anderson Cancer Center in Houston. Most treatment decisions now are based on cancer type, said tho- racic oncologist Edward Kim, the study’s lead author. That is likely to change as more studies show the benefit of tailoring treatment to the individual, said Anil Potti, an associate professor of medi- cine at Duke University.
ed,” Potti said. “It shows that get- ting biopsies and treating pa- tients based on those biopsies is feasible in lung cancer today. It’s a huge advance in lung cancer re- search and in the whole concept of personalized medicine.” In the study, patients who had been treated with chemotherapy in the past underwent another bi- opsy. Tumor samples were tested for cancer biomarkers, including mutations to a gene called KRAS and to EGFR, or epidermal growth factor receptor, a protein that causes cancer cells to grow and divide. Patients were placed into five
marker groups. A first subset was assigned to one of four drugs without regard to their biomark- ers. Patients in a second wave were assigned to drugs based on their particular tumor biomark- ers, taking into consideration how people in the first group with sim- ilar biomarkers were faring. Overall disease control — de-
fined as “non-progression” of the cancer — among all participants was 46 percent after eight weeks, Kim said. However, about 71 per- cent of patients with mutations involving EGFR who were given Tarceva, which is designed to in- hibit EGFR, had disease control at eight weeks. Among those with KRAS gene mutations, 61 percent had non-progression of their can- cer when given Nexavar, Kim said.
Supplements succeed
Calcium doesn’t just build strong bones; it may also fight cancer.
Researchers at the Ponce School of Medicine in Puerto Rico reported that women who took calcium had a 40 percent lower risk of getting breast cancer, while those getting multivitamins showed a 30 percent reduction. The data contradict results of a
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2008 trial that showed no reduc- tion in cancer risk from vitamin supplements. The scientists at- tributed the calcium benefit seen in the study to its effect on what they called DNA repair capacity, the biological process by which cells patch up damaged DNA that otherwise may cause cancer. The report suggests women may boost their cellular defenses with die- tary changes and long-term use of supplements, they said. “Now we can monitor breast cancer risk using DNA repair ca- pacity,” said Manuel Bayona, a professor of biostatistics and epi- demiology and an author of the paper. A good analogy, Bayona said, is the management of heart disease. Just as doctors track patients’ cholesterol and modify it with changes in diet or drugs, they might use blood tests to monitor the DNA repair ability of women at elevated risk for breast cancer and tweak it using dietary supple- ments. The study included 744 women: 278 with breast cancer and 466 healthy controls. They were given a questionnaire that included sev- eral questions about their current and past intake of particular vita- mins and minerals. The research- ers also took blood samples to measure DNA repair capacity.
Monitoring breast density
Increases in breast density in a
year’s time may signal a higher risk of breast cancer in post- menopausal women taking estro- gen and progestin, according to a study. The authors urged doctors to monitor such changes. The study found that 20 per- cent of 475 women taking the hor- mone treatments had more than a 19 percent rise in breast density. That increase translated into 3.6 times as many cases of cancer, ac- cording to the study data. While the study noted that breast density has long been “one of the strongest predictors of risk,” this trial is among the first to show how short-term changes can affect a woman’s susceptibil- ity to the disease. “The findings suggest post-menopausal women taking hormones who experience a significant increase in breast density should reconsider their decision to take hormones,” said Rowan Chlebowski, a co-author of the study. The results also in- dicate that “there is not enough focus on breast density in gener- al.”
Chlebowski and his co-authors
worked with the Women’s Health Initiative, a National Institutes of Health program focused on post- menopausal women.
ALCOHOLISM RUINS LIVES...
...and not just the alcoholic’s. If you or someone you know needs help, here’s an option: The National Institute on Alcohol Abuse and Alcoholism conducts research studies into alcohol and its effects. Qualified subjects who participate in research will receive in-patient treatment at no charge. For information, please call
301-496-1993
Deaf or hard of hearing?
Use your state relay service to call.
National Institutes of Health Dept. of Health & Human Services
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