Tag Archives: Columbian College of Arts and Sciences

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

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

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

Redrawing the Poverty Line

For those who help the poor, a bit of math is exposing a kaleidoscopic view of poverty.

The formula composed by Dr. Foster and Dr. Alkire to help measure and alleviate poverty has also inspired art. In this painting, the formula weaves among a flock of canaries. (Art by Regina Glassman Foster)

The formula composed by Dr. Foster and Dr. Alkire to help measure and alleviate poverty has also inspired art. In this painting, the formula weaves among a flock of canaries. (Art by Regina Glassman Foster)


By Andrew Eder

On the wall of economist James Foster’s office hangs a painting of blossoming roses, connected by a stem. Woven into the dark background is a repeating string of letters and symbols—a piece of a mathematical formula.

Muted and gray, the equation would seem a strange accompaniment for the vibrant red roses. But like the roses, it hints at a brighter future.

The formula—developed by Dr. Foster, a GW professor of economics and international affairs, and Sabina Alkire of Oxford University—is redefining the meaning of poverty and, with it, reshaping our understanding of how to ease that burden. It’s used to measure “multidimensional poverty”—the concept that poverty and well-being are defined by factors such as education, health, and housing, not just income. The United Nations Development Program has made use of it, as have the governments of Mexico and Colombia, and other organizations looking to extend their definition of poverty beyond the traditional “dollar-a-day” measure.

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

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

“Education, health, sanitation, asset-building, quality of jobs—these are all dimensions of poverty,” says Dr. Foster, who is director of the Institute for International Economic Policy (IIEP) at the Elliott School of International Affairs.

That kind of data, he says, can generate a comprehensive, three-dimensional image of poverty capable of helping policy hit its mark.
Continue reading

Study: Brain Region Tied to Empathy in Humans Equally Present in Other Primates

GW biological anthropologist Chet Sherwood holds a specimen in his lab. (Photo by Jessica McConnell Burt)

GW biological anthropologist Chet Sherwood holds a specimen in his lab.
(Photo by Jessica McConnell Burt)

The part of the human brain that is linked to mankind’s unique sense of empathy also grows to the same scale in an array of other primates, according to a new study.

The findings, which came as a surprise to researchers, don’t suggest chimpanzees will be getting talk shows anytime soon. Instead the study shows that “the difference between us and great apes is incremental,” said lead researcher Amy Bauernfeind, a GW doctoral candidate. “That, in fact, we’re just seeing an expansion of an already present pattern that exists in primates.”

The study, published in the April issue of the Journal of Human Evolution, was co-led by GW anthropology professor Chet Sherwood.

In these sketches from the renowned medical text Gray's Anatomy, the left insula of a human brain is exposed (top) and shown in a cross section (bottom) of the brain, with highlights added. (Images via Wikimedia Commons) In these sketches from the renowned medical text Gray’s Anatomy, the left insula of a human brain is exposed (top) and shown in a cross section (bottom) of the brain, with highlights added. (Images via Wikimedia Commons)

The research team studied a part of the brain called the insula in 30 species of primates, from humans and gorillas to the wide-eyed slender loris.

Wedged between lobes on both sides of the brain’s main processing hub, the insula has been associated with functions that include recognition of oneself and emotions, empathy, and the processing of music and language—the kinds of cognitive advances, the authors wrote, that may have helped distinguish mankind and its social interactions.

In particular, the group was interested in measuring the volume of the whole insula as well as each of its components. For all 30 species they examined the left insula; for humans and great apes, they looked at both left and right insulae.

What the researchers expected to find, Ms. Bauernfeind said, was that the volume of the whole insula would be uniquely large among humans—and it was, but only because humans have the largest brains of the group. (For example: Despite having roughly the same body size as chimpanzees, mankind’s closest living relatives, the human brain is three times as large the chimp’s, she said.)

Once the researchers adjusted for overall brain size, a pattern emerged across the primates: as the size of the brain increased, the insulae grew slightly more than the rest of the brain. The pattern was strong enough that it could be used to predict measurements.
Continue reading

The Godmother of Rock and Roll

Sister Rosetta Tharpe performing in New York’s Café Society in 1940. (Image by Charles Peterson; courtesy Don Peterson)

Sister Rosetta Tharpe performing in New York’s Café Society in 1940.
(Image by Charles Peterson; courtesy Don Peterson via American Masters)

Before there was Bill Haley, rocking around the clock, before there was Elvis Presley, shaking his hips and tearing it up on the guitar, before there were the Beatles and their lyrics and their haircuts—before there was rock and roll, there was Sister Rosetta Tharpe.

If that name isn’t familiar to you, you’re not alone, said GW Professor of English Gayle Wald, author of the 2007 book Shout, Sister, Shout: The Untold Story of Rock-and-Roll Trailblazer Sister Rosetta Tharpe.

Ms. Tharpe, an African American gospel musician, became one of gospel music’s biggest stars and most celebrated guitarists, and inspired a diverse set of musicians who followed her. But because she enjoyed none of the privileges of white male musicians, she has remained relatively unknown to modern audiences despite the commercial success of her recordings. Now Ms. Tharpe, who died in 1973, is the subject of a documentary film based on Dr. Wald’s book that will air on PBS’s “American Masters” on Friday, Feb. 22 at 9 p.m.

“[Rosetta Tharpe] wasn’t quite marginalized, but she was kind of ironically shut out,” Dr. Wald explained. “Like a lot of early influences, she was there at the very moment rock and roll emerged.”

(Continue reading the story by Laura Donnelly-Smith at GW Today)