Influenza & Flu Vaccines -- Science Behind The News

Every flu season, Americans battle coughs, fevers and body aches. The flu is a respiratory illness caused by a virus, a pathogen that causes disease in the human body. To understand how the flu is caught, spread and treated, Duke University's Katia Koelle explains the biology of a virus and how it is transmitted.

Credit: NBC Learn and the National Science Foundation

Epiphytic Fern Hymenophyllum jamesonii

Hymenophyllum jamesonii, an epiphytic fern of neotropical rain forests, has berry-like clusters of sporangia where reproductive spores are produced.

Eric Schuettpelz, a postdoctoral fellow in biology at the time, and Kathleen Pryer, an associate professor at Duke University, integrated genomic data from 400 living fern species with information from the fossil record to construct a time-calibrated family tree for ferns.

Schuettpelz and Pryer received support from the National Science Foundation. To learn more, see the Duke news story Ferns Took to the Tress and Thrived.

(Date of Image: 2008)

Credit: Courtesy Eric Schuettpelz, Duke University

It's Wildflower Season on Mountain Peaks, But Alpine Plants May Soon Miss the Date

Study conducted over 38 years shows one species' timing has shifted by 13 days

July brings a riot of color--a rainbow-hued carpet of wildflowers--to the high peaks of the Rockies.

In these mountain environments, however, plants have a narrow window of opportunity to set their buds.

Now, in a changing climate, that hurry-up-and-flower date is moving ever earlier on the calendar. How quickly can plants respond?

The alpine growing season in places like the Rockies doesn't begin until snows melt, sometimes as late as June. Snows may fall again by October.

In such habitats, snow covers the ground for eight to nine months of the year--or used to. In recent decades, climate change has warmed the planet and caused snows to melt earlier.

In response, plants and animals at high altitudes become active much sooner. In the case of plants, is it because their populations are evolving or because their flowering time is flexible?

A paper published this week in the journal Proceedings of the Royal Society of London - Biological Series reports that climate change has significantly affected Drummond's rockcress (Boechera stricta), an alpine plant native to the Rocky Mountains.

Using a unique combination of long-term data on the timing of flowering and snowmelt, and an experimental genetics approach, ecologists Jill Anderson of Duke University, David Inouye and Amy McKinney of the University of Maryland and Colorado's Rocky Mountain Biological Laboratory and colleagues found that Drummond's rockcress flowered 13 days earlier in 2011 than in 1973.

Other co-authors of the paper are Robert Colautti of the University of British Columbia and Thomas Mitchell-Olds of Duke University.

The change results from a combination of earlier flowering by individual plants and gradual genetic changes in the population of wildflowers.

"More than 38 years of data on flowering time gives us important insights into how this wildflower--and other species--is responding to climate change," said Inouye.

If climate change continues at the same rate, Drummond's rockcress should bloom a month sooner by 2100 than it does now.  Do the plants have the flexibility to change flowering time that much?

"Global climate change imposes severe new stresses on organisms," said Anderson. "Species that cannot evolve fast enough risk extinction."

Faced with a new but uncertain threat, remaining flexible makes the most sense, said Saran Twombly, program director in NSF's Division of Environmental Biology, which funded the research. "So it is with the plant species studied here. Flexibility in response to rising temperatures will contribute directly to its success."

Plants have evolved to bloom in response to certain climate conditions. Those conditions--timing of snowmelt, growing season temperature, and light levels--have always signaled the beginning of the growing season.

Temperatures may increase into the foreseeable future, scientists believe, but climate change is unlikely to affect environmental variables such as light.

That results in a decoupling of previously reliable--and linked--cues, potentially disrupting the reproductive biology of many species that rely on multiple signals to bloom.

At the end of each summer, the seeds of Drummond's rockcress fall just beneath the mother plant. So the species has a limited ability to migrate to higher elevations to escape increasing temperatures.

Drummond's rockcress will need to adjust to climate change not by moving to cooler environs, but by finding a way to thrive right where it lives.

How will it succeed? Inouye says it will happen through a long-term combination of changing responses by individual plants and evolutionary changes by the population of wildflowers.

The only hope--at least for the Drummond's rockcress--may be as an earlier and earlier early-bloomer.

-- Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov

Relationship Between Social Status and Wound-Healing in Wild Baboons

Findings show it's best to be "top baboon"

Turns out it's not bad being top dog, or in this case, top baboon.

Results of a study by University of Notre Dame biologist Beth Archie and colleagues from Princeton University and Duke University finds that male baboons that have a high rank within their society recover more quickly from injuries, and are less likely to become ill than other males.

The finding is somewhat surprising, given that top-ranked males also experience high stress, which should suppress immune responses.

Archie, Jeanne Altman of Princeton and Susan Alberts of Duke examined health records from the Amboseli Baboon Research Project in Kenya. They published their results in this week's issue of the journal Proceedings of the National Academy of Sciences.

The scientists also found that social status is a better predictor of wound-healing than age.

"The power of this study is in identifying the biological mechanisms that may confer health benefits to high-ranking members of society," says George Gilchrist, program director in the National Science Foundation's (NSF) Directorate for Biological Sciences, which co-funded the research with NSF's Directorate for Social, Behavioral & Economic Sciences.

"We know that humans have such benefits, but it took meticulous long-term research on baboon society to tease out the specific mechanisms," says Gilchrist. "The question remains of causation: is one a society leader because of stronger immune function or vice versa?"

Although research on health and disease in animals in laboratory settings has been extensive, this study is one of the most comprehensive conducted on animals in a natural setting, the scientists say.

The researchers examined 27 years of data on naturally-occurring illnesses and injuries in wild male baboons. They investigated how differences in age, physical condition, stress, reproductive effort and testosterone levels contribute to status-related differences in immune function.

Previous research found that high testosterone levels and intense reproductive efforts can suppress immune function and are highest among high-ranking males.

However, Archie and colleagues found that high-ranking males were less likely to become ill and recovered faster from injuries and illnesses than low-ranking males.

The authors suggest that chronic stress, old age and poor physical condition associated with low rank may suppress immune function in low-ranking males.

"The complex interplay among social context, physiology and immune system-mediated health costs and benefits illustrates the power of interdisciplinary research," says Carolyn Ehardt, program director in NSF's biological anthropology program.

"This research begins to tease apart the trade-offs in both high- and low-status in primates--including ourselves--which may lead to a new understanding of the effects of social status on death and disease."

 -NSF-

World’s best measurement of W boson mass points to Higgs mass and tests Standard Model

The world’s most precise measurement of the mass of the W boson, one of nature’s elementary particles, has been achieved by scientists from the CDF and DZero collaborations at the Department of Energy’s Fermi National Accelerator Laboratory. The new measurement is an important, independent constraint of the mass of the theorized Higgs boson. It also provides a rigorous test of the Standard Model that serves as the blueprint for our world, detailing the properties of the building blocks of matter and how they interact.

The Higgs boson is the last undiscovered component of the Standard Model and theorized to give all other particles their masses. Scientists employ two techniques to find the hiding place of the Higgs particle: the direct production of Higgs particles and precision measurements of other particles and forces that could be influenced by the existence of a Higgs particles. The new measurement of the W boson mass falls into the precision category.

The CDF collaboration measured the W boson mass to be 80387 +/- 19 MeV/c2. The DZero collaboration measured the particle’s mass to be 80375 +-23 MeV/c2. The two measurements combined along with the addition of previous data from the earliest operation of the Tevatron produces a measurement of 80387 +- 17 MeV/c2, which has a precision of 0.02 percent.

These ultra-precise, rigorous measurements took up to five years for the collaborations to complete independently. The collaborations measured the particle’s mass in six different ways, which all match and combine for a result that is twice as precise as the previous measurement. The results were presented at seminars at Fermilab over the past two weeks by physicists Ashutosh Kotwal from Duke University and Jan Stark from the Laboratoire de Physique Subatomique et de Cosmologie in Grenoble, France.

“This measurement illustrates the great contributions that the Tevatron has made and continues to make with further analysis of its accumulated data,” said Fermilab Director Pier Oddone. “The precision of the measurement is unprecedented and allows rigorous tests of our underlying theory of how the universe works.”

The new W mass measurement and the latest precision determination of the mass of the top quark from Fermilab triangulate the location of the Higgs particle and restrict its mass to less than 152 GeV/c2 .This is in agreement with the latest direct searches at the LHC, which constrain the Higgs mass to less than 127 GeV/c2, and direct-search limits from the Tevatron, which point to a Higgs mass of less than 156 GeV/c2, before the update of their results expected for next week.

“The Tevatron has expanded the way we view particle physics,” said CDF co-spokesperson and Fermilab physicist Rob Roser. “Tevatron experiments discovered the top quark, made precision measurements of the W boson mass, observed B_s mixing and set many limits on potential new physics theories.”

The new measurement comes at a pivotal time, just days before physicists from the Tevatron and the Large Hadron Collider at CERN will present their latest direct-search results in the hunt for the Higgs at the annual conference on Electroweak Interactions and Unified Theories known as Rencontres de Moriond in Italy. The CDF and DZero experiments plan to present their latest results on Wednesday, March 7.

“It is a very exciting time to analyze data at particle colliders,” said Gregorio Bernardi, DZero co-spokesperson and physicist at the Laboratoire de Physique Nucléaire et de Hautes Energies in Paris. “The next few months will confirm if the Standard Model is correct, or if there are other particles and forces yet to be discovered.”

The existence of the world we live in depends on the W boson mass being heavy rather than massless as the Standard Model predicts. The W boson is a carrier of the electroweak nuclear force that is responsible for such fundamental process as the production of energy in the sun.

“The W mass is a very distinctive feature of the universe we live in, and requires an explanation,” said Giovanni Punzi, CDF co-spokesperson and physicist from the University of Pisa. “Its precise value is perhaps the most striking evidence for something “out there” still to be found, be it the Higgs or some variation of it.”

“The measurement of the W boson mass will be one of the great scientific legacies of the Tevatron particle collider,” added DZero co-spokesperson and Fermilab scientist Dmitri Denisov.

Mine-Hunting Software Helping Doctors to Identify Rare Cells in Human Cancer

By Grace Jean, Office of Naval Research Public Affairs

ARLINGTON, Va. (NNS) -- Medical researchers are demonstrating that Office of Naval Research (ONR)-funded software developed for finding and recognizing undersea mines can help doctors identify and classify cancer-related cells.

"The results are spectacular," said Dr. Larry Carin, professor at Duke University and developer of the technology. "This could be a game changer for medical research."

The problem that physicians encounter in analyzing images of human cells is surprisingly similar to the Navy's challenge of finding undersea mines.

When examining tissue samples, doctors must sift through hundreds of microscopic images containing millions of cells. To pinpoint specific cells of interest, they use an automated image analysis software toolkit called FARSIGHT, or Fluorescence Association Rules for Quantitative Insight. Funded by the National Institutes of Health (NIH) and the Defense Advanced Research Projects Agency, FARSIGHT identifies cells based upon a subset of examples initially labeled by a physician. But the resulting classifications can be erroneous because the computer applies tags based on the small sampling.

By adding ONR's active learning software algorithms, the identification of cells is more accurate and FARSIGHT's performance more consistent, researchers said. The enhanced toolkit also requires physicians to label fewer cell samples because the algorithm automatically selects the best set of examples to teach the software.

"This is not a typical Navy transition," said Carin. "But it is a transition to a very important medical tool used literally at hospitals around the world. There is a real chance this may save lives in the future."

A medical team at the University of Pennsylvania is applying the ONR algorithms, embedded into FARSIGHT, to examine tumors from kidney cancer patients. Focusing on endothelial cells that form the blood vessels that supply the tumors with oxygen and nutrients, the research could one day improve drug treatments for different types of kidney cancer, also known as renal cell carcinoma.

"With the computer program having learned to pick out an endothelial cell, we have now automated this process, and it seems to be highly accurate," said Dr. William Lee, an associate professor of medicine, hematology and oncology at the university who is leading the research effort. "We can begin to study the endothelial cells of human cancer-something that is not being done because it's so difficult and time-consuming to do."

It usually takes days, even weeks, for a pathologist to manually pick out all the endothelial cells in 100 images. The enhanced FARSIGHT toolkit can accomplish the same feat in a few hours with human accuracy.

"This is an important NIH-funded clinical study that we're supporting with FARSIGHT, and Dr. Carin's active learning system has been a great success," said Dr. Badri Roysam, an electrical and computer engineering professor at the University of Houston and program investigator for FARSIGHT.

ONR's active learning software was originally developed to allow robotic mine-hunting systems to behave more like humans when they are uncertain about how to classify an object. Using information theory, the software asks a human to provide labels for those items. This feature is valuable in mine warfare, where identifying unknown objects beneath the ocean has been accomplished traditionally by sending in divers.

"This is dangerous and is exactly what we're trying to eliminate," said Dr. Jason Stack, the program officer at ONR who funded Carin's research. "Developing unmanned systems that are not only autonomous but can also continuously learn from the warfighters employing them is core to our strategy. It speeds up mine countermeasures and helps get the man out of the minefield."

ONR provides the science and technology necessary to maintain the Navy and Marine Corps' technological advantage. Through its affiliates, ONR is a leader in science and technology with engagement in 50 states, 70 countries, 1,035 institutions of higher learning and 914 industry partners. ONR employs approximately 1,400 people, comprising uniformed, civilian and contract personnel, with additional employees at the Naval Research Lab in Washington, D.C.