Author Archives: Danny

Cellular Crowdsourcing Controls Genes

Cells move and divide, tissues develop, and organs form all as part of a highly orchestrated dance to achieve life. But how does a cell know whether it should stay where it is or move to a different location? How does a cell transform itself to become a skin cell or a fat cell or a blood cell?

The answer, at least in part, appears to be: crowdsourcing. A recent study by GW researcher Weiqun Peng finds that, in the case of developing fat and muscle cells, one type of protein can steer the regulation of thousands of genes by recruiting other molecules to help.

In most cells, the tiny nucleus contains full copies of every gene in a genome. In humans, for instance, almost every cell in the body contains each of our species’ 20,000 or so genes. Controlling gene expression—that is, whether a gene is on or off—is vital; the identity of each cell depends on the combination of genes that are turned on and off as the cell develops. Genes that are over- or under-expressed can result in stunted growth or development, or diseases such as cancer and diabetes.

It’s a sophisticated control system, with many different factors and signals regulating when and where genes are expressed. Similar to crowdsourcing, the outcome often depends on the factors that are found at a specific place and time.
Continue reading

Finding a Needle in a Cosmic Haystack

A new way to pinpoint the locations of distant exploding stars may open a cache of celestial fireworks for deeper study, broadening scientists’ understanding of the most violent eruptions in the universe.

In research published last month, scientists said that for the first time they have zeroed in on the visible-light remains of a dying star based solely on a large swath of sky provided by a NASA satellite, after it detected a telltale burst of invisible gamma rays.

The study, appearing in the Oct. 20 edition of Astrophysical Journal Letters, was led by the California Institute of Technology and included GW physics professor Alessandra Corsi among an international team of researchers.

Gamma-ray bursts are generated in rare occasions during the fiery collapse of massive, spinning stars, likely marking the formation of a black hole. Pinpointing the location of a burst using only visible light, the researchers said, is akin to finding a needle in a cosmic haystack.


(Video by NASA’s Goddard Space Flight Center)

Spotting gamma-ray bursts involves using data from a space observatory, in this case NASA’s Fermi Gamma-ray Space Telescope. While Fermi’s Gamma-ray Burst Monitor detects more than 200 of these each year, homing in on the location usually requires additional telescopes that search for light in various wavelengths, such as X-rays, radio waves and visible light, after the gamma rays are detected.

But access to high-powered telescopes for follow-up is costly and difficult to get, Dr. Corsi, said, often making such wide-ranging hunts impractical. A big stretch of sky can produce a glut of candidate light sources to check out—in the case of the new study, around 24,000.
Continue reading

Study: To Determine Link Between Humans and Neanderthals, Keep Digging

The skull of a Neanderthal that was found on Gibraltar in the 1800s.
(Photo by AquilaGib, via Wikimedia Commons.)


It’s a gap between teeth that will need much more than braces to fix: A new study of ancient teeth finds that none of the species suspected of being the ancestral link between modern humans and Neanderthals quite fits the bill.

The study, published online Monday in the Proceedings of the National Academy of Sciences, also suggests that the two species may have diverged hundreds of thousands of years earlier than previously thought.

“The last common ancestor of Neanderthals and modern humans may have been located in Africa around 1 million years ago,” said lead researcher Aida Gómez-Robles, a postdoctoral scientist at GW’s Center for the Advanced Study of Hominid Paleobiology. “If those fossils are found, they will be the ones that can give us a clearer answer to this problem.”

That may mean finding new species or simply better-preserved fossils. African populations dating back 1 million years—which were not included in the study due to the scarcity of dental fossils, Dr. Gómez-Robles said—are “the most promising source of candidates,” the researchers wrote.
Continue reading

Past Month Nets $13M in Federal Research Grants

In a banner, month-long stretch for the university, GW researchers have been awarded more than $13 million in grant funding from federal agencies.

The eight awards announced between late August and late September, each more than $1 million, will fund research projects that range from studying autoworkers’ risk of developing renal disease and kidney cancer; to changes in the brain between the fetal and postnatal periods; to building a partnership with Lahore College Women’s University, in Pakistan, that will support collaborative education and research on gender and development issues.

GW Vice President for Research Leo Chalupa told GW Today he has not seen anything like this streak during his four years at the university. “I think what it really shows, more than anything else, is the fact that we have faculty who are able to be competitive in a very, very challenging climate,” Dr. Chalupa said. “At a time when almost nine out of 10 applications get turned down, it is really remarkable.”

For brief descriptions of the eight awards, read the complete coverage in GW Today.

Looking for Bugs in All the Right Places

The bacteria E. coli was one of three found in the ear of Dr. Crandall’s chocolate lab, Mousse. But the vet’s tests gave no details on the strain (not all E. coli is bad), and only genus-level info on the other two. (Courtesy Janice Haney Carr, Centers for Disease Control and Prevention)

As humble beginnings go, it doesn’t get much more humble than an infection in a dog’s ear.
 
Keith Crandall, director of GW’s Computational Biology Institute, had taken his Labrador retriever to a veterinarian to have the bug evicted but was disappointed by the options: lob an antibiotic grenade and hope it does the job, or for $150 and a week’s time have a lab identify the pathogen and a more targeted fix.
 
The lab would be “growing up the bacteria and looking at it under a microscope,” Dr. Crandall said. “That’s a hundred-year-old technology, Jack. I was thinking, ‘Well I can do that cheaper, better, faster.’”
Continue reading

Seeing Through the Blaze

In 1985, Philadelphia police dropped explosives on a house filled with members of the extremist African-American MOVE organization after years of conflict between the two groups. A resulting fire, which destroyed 61 homes and killed 11 people, five of them children, was allowed to burn for more than an hour despite firefighters standing by.

Jason Osder’s new film has been screening at some of the nation’s top festivals. (Photo by Jessica McConnell Burt)

Media and Public Affairs professor, and Philadelphia native, Jason Osder researched this catastrophe for nearly a decade for his new documentary, Let the Fire Burn. The film is coming to theaters this fall after winning praise at some of the most prestigious festivals in the country. At the Tribeca Film Festival, in April, the film earned two awards—“Best Editing in a Documentary Feature” and a special jury mention in the “Best New Documentary Director” category—and at AFI Docs, in June, it was selected as one of the “Best of the Fest.”

Professor Osder talked with GW Magazine’s Caitlin Carroll about the film.

Why did you decide to make the film using only archival materials—no interviews or narration?
I never wanted to interview everyone who had anything to say about this. I wanted to find a handful of people who were really participants. I was doing fairly well with that up until I brought the editor on, and when we looked at all the materials we realized that the interviews had certain liabilities and the archival materials had certain strengths. We saw a creative opportunity and we thought the result would really keep you in the moment—the past in present tense.

If it worked, it would be something special. And if it didn’t work it would sort of fall on its face. It wouldn’t really be a film.
Continue reading

The Light Stuff: One-inch thrusters built for small-scale, inexpensive satellites

NASA’s diminutive PhoneSat 1.0 sits beside a coffee mug. Future models in the nanosatellite program could be propelled by thrusters designed at GW. (NASA/Ames)

Tiny thrusters built by GW researchers soon may be making their maiden voyage to space, propelling pint-sized satellites for NASA, if tests go well this summer.

“Hopefully this will lead to the next level of funding that will end up with a flight,” said mechanical and aerospace engineering professor Michael Keidar of a planned demonstration later this month at NASA’s Ames Research Center, in California.

The thrusters would be for a future generation of NASA’s diminutive PhoneSats—four-inch cubes, weighing about two pounds, that each run on one, off-the-shelf Google smartphone. The project is aimed at testing the capacity for building spacecraft from powerful but inexpensive, everyday components, which could be used to conduct space science at a fraction of the cost of full-size satellites.

The first launch of NASA’s $3,500-PhoneSats took place in April, during which the trio of nanosatellites transmitted back data, including photographs, and became the lowest-cost satellites ever flown in space, according to NASA.
Continue reading

A New Target in the Fight Against TB

A scanning electron micrograph of Mycobacterium tuberculosis, the bacteria that causes tuberculosis. (Image by National Institute of Allergy and Infectious Diseases)

Researchers have identified a potential new route for attacking tuberculosis that may hold promise against drug-resistant strains of the disease and even dormant TB infections.

In a new study, led by GW chemistry professor Cynthia Dowd, researchers designed and tested molecules that work like a chemical Trojan Horse, sneaking past the defenses of TB-causing bacterial cells and, once inside, blocking functions essential for survival.

The study appears in the July 1 edition of the medicinal chemistry journal MedChemComm.

“TB remains a huge threat to global public health,” Dr. Dowd said. “… New therapeutics are essential for combating drug-resistance and staying one step ahead of the bug, so to speak. Our work seeks to validate a drug target that is not used by current drugs.”
Continue reading

Researchers Unwind the Evolution of Throwing

(Photo by Flickr user Becka Spence)

(Photo by Flickr user Becka Spence)

Modern man may have perfected the fastball, but it was our ancestors from nearly 2 million years ago who likely were the first to throw it, according to a new study.

The ability to throw objects with speed and accuracy requires a constellation of anatomical features that evolved over time and first came together around 2 million years ago in the early human species Homo erectus, researchers report this week in the journal Nature. The timing, they write, coincides with archaeological evidence of early hunting activity.

The study is the first to trace the origins of powerful throwing and to propose a link to the dawn of hunting, a development that sparked a seismic shift in human history, said lead researcher Neil Roach, a postdoctoral scientist at GW’s Center for the Advanced Study of Hominid Paleobiology.
Continue reading

Greening a Ubiquitous Gray

For thousands of years producing cement has meant producing carbon dioxide. Stuart Licht believes it’s time to let in the sun.

By Rachel Kaufman

It’s an essential part of the glue that builds cities and much of the space between them. But the process of creating cement, a chief ingredient in concrete, generates nearly as much of the greenhouse gas carbon dioxide as it does cement.

Chemistry professor Stuart Licht thinks he can cut that rate—to zero.

He’s developed a solar-powered process that recently was awarded a four-year, $1.7 million grant from the National Science Foundation. Now Dr. Licht and an interdisciplinary team of GW scientists are refining the proof-of-concept.

It may take years, but if perfected and commercialized, Dr. Licht’s “solar cement” could go a long way toward greening an industry that he says accounts for around 5 percent of the world’s manmade CO2.

See the story in the Spring 2013 issue of GW Research magazine.

Dr. Licht has already applied the process to the CO2-free production of iron, bleach, and other materials. The effort is part of a broader vision for what he has called a “renewable chemical economy”—one that produces commodities through sustainable processes, shedding fossil fuel-intensive ones.

“Rising carbon dioxide levels, and the associated climate consequences, provide one of the most daunting challenges of our time,” said Dr. Licht.
Continue reading