This week’s papers from Boston labs
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Puffy planet could float on water
Astronomers call it HAT-P-1b, but maybe we should call it Puff Daddy. A new study has spotted the puffiest planet anywhere, orbiting a star in another solar system.
The discovery, reported this week in the Astrophysical Journal, is the first discovery from an ongoing hunt by a set of six telescopes around the world. The broad survey is searching the sky for so-called transiting exoplanets—planets outside our solar system that reveal themselves by passing in front of the star they orbit, obstructing its light. This is the only way that researchers can get an accurate reading of the planet’s mass and size.
The new study, led Gaspar Bakos at the Harvard-Smithsonian Center for Astrophysics, found that HAT-P-1b is a third larger in diameter than Jupiter, our solar system’s largest planet. But it’s only half of Jupiter’s mass, resulting in a density close to that of cork.
Researchers had found only one planet nearly as puffy as HAT-P-1b before, and thought it would be unique. But now with two of them—out of only 11 transiting exoplanets found so far—they may not be so rare after all, Bakos and colleagues say. Mason Inman
Brain tumors use stem cell strategy to grow
A gene regulator that spurs the growth of brain stem cells during early life also drives the later development of some deadly brain tumors, according to a new study by local researchers.
Many tumors contain a small population of rapidly growing cells, which scientists believe makes tumors cancerous. These so-called tumor stem cells, first isolated only about 10 years ago, are thought to be genetically mutated versions of normal stem cells that form healthy new tissue. But how the cancer stem cells come about and how they might be related to normal stem cells are not well understood. Learning more about the molecular mechanisms of these cells could reveal new ways of killing tumors at their root or stopping them from growing.
In their study of tumor stem cells from human gliomas, a type of brain cancer, researchers in the labs of Charles Stiles and David Rowitch at the Dana-Farber Cancer Institute found that the normal neuronal stem cells and the cancer stem cells both had a growth-promoting protein called Olig2, which boosted cell division in both types of cells.
Further, they showed that Olig2 was required for tumor growth. Turning off the gene in a mouse model of glioma prevented the animals from developing cancer.
Because Olig2 is found mainly in the central nervous system and not in normal adult brain cells, it could provide a specific drug target for treating brain cancers that would spare other tissues and normal neurons.
The work appears in Neuron. Pat McCaffrey
Afternoon naps may protect your heart
Hitting the couch after lunch for a quick siesta may not seem like a wise career move for busy professionals, but new data suggests that it could save your life.
After studying more than 20,000 healthy Greek adults, researchers from the Harvard School of Public Health and Athens Medical School report that people who took regular afternoon naps (at least three times per week for 30 minutes each) had a more than 30 percent lower risk of dying from heart disease. Less frequent napping reduced deaths by 12 percent.
Previous epidemiological studies on napping and heart disease mortality have reached conflicting conclusions. To try to address some of the shortcomings of these other studies, the investigators took into account confounding factors like diet, exercise, and body weight, and limited their study to healthy people in a country where napping is common.
The results could explain why societies where people nap frequently (Mediterranean and some Latin American countries) have overall lower death rates from coronary heart disease. The researchers speculate that afternoon snoozing may act as a stress reducer.
The study appeared in the Archives of Internal Medicine. Pat McCaffrey