How did birds emerge from a lineage of large dinosaurs whose clawed feet were planted firmly on the ground? Size really matters, according to a team of scientists that traced the incredibly fast shrinkage along 50 million years of ancient avian evolution.
The findings, published in the journal Science, show how the continuous miniaturization of this dinosaur lineage allowed for a whole host of physical changes that made powered flight possible.
Paleontologists have long known that birds evolved from dinosaurs known as theropods, a group that included the formidable Tyrannosaurus rex. But there’s been considerable argument over whether the branch of theropods leading to birds really was quickly shrinking until the earliest birds emerged roughly 160 million years ago.
Previous analyses may not have been reliable because they focused on fast-evolving branches of the theropod family tree, or because they only looked at the evolution of a few traits, the study authors said.
So the...Read more
It was a dumbfounding discovery. Using Hubble telescope data, a scientist spotted a "lensing" galaxy that was enormous, extremely distant and acting as a magnifying glass to another ancient galaxy behind it.
Kim-Vy Tran was sure she'd flubbed.
The Texas ARead more
As international medical providers warned Friday that the Ebola virus threatened to rage "out of control" in West Africa, a top U.S. health official said that proper medical care and infrastructure could greatly reduce Ebola's lethality.
On Friday, Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said that the species of the current Ebola virus outbreak was very closely related to the so-called Zaire strain -- the most virulent of the five known strains.
While there is currently no vaccine for the disease -- and there is unlikely to be one for at least a year -- Fauci said proper medical care could reduce the rate of death.
"You could have a strain that’s real virulent, like the Zaire strain and in conditions in which individuals don’t go to a healthcare center, don’t get intravenous replacement of fluids, don’t get anti-inflammatories to bring their fever down, don’t get supportive care, and don’t get antibiotics for secondary bacterial infections,...Read more
With Emory University Hospital in Atlanta planning to receive and treat two U.S. citizens who are sick with the Ebola virus, some Americans have expressed fear that a deadly outbreak -- which has killed at least 729 people in West Africa -- could spread in the United States.
If you're one of them, you can calm down. Health officials say there is virtually no danger to the public. Here’s what you need to know about the deadly virus:
What’s the likelihood of a major Ebola outbreak happening in the U.S.?
Remote, according to officials from the Centers for Disease Control and Prevention. If an Ebola patient were to be identified here, American health systems would quickly identify, isolate and treat the person, along with anyone who may have come into contact with him or her.
The CDC and the World Health Organization say it’s very unlikely that American travelers to West Africa could contract the disease, since they would have to come in direct contact with an infected person’s blood,...Read more
As U.S. health providers prepared for the arrival of two Americans infected with the deadly Ebola virus, international health officials warned Friday that the outbreak in Africa was oustripping their ability to control it.
The medical evacuation from Liberia to Atlanta of two stricken American citizens will occur by the end of the weekend, according to the Christian aid organization Samaritan’s Purse.
“Dr. Kent Brantly, a doctor working for Samaritan's Purse, and Nancy Writebol, a missionary with SIM, are currently in serious condition. The two Americans who contracted Ebola in Liberia remain in the country today but medical evacuation efforts are underway and should be completed by early next week,” read a prepared statement Friday from Samaritan’s Purse.
Emory University Hospital in Atlanta confirmed Thursday that there were plans to transfer “a patient” with Ebola virus to its special containment unit within several days. The isolation units were built in cooperation with the U.S....Read more
Researchers have created see-through mice and rats using a new technique for so-called tissue clearing.
In a paper published Thursday in the journal Cell, a California Institute of Technology professor and her colleagues said they had turned a dead mouse transparent in a week's time, while a rat specimen took two weeks to treat.
The technique, which can also be used to create transparent organs for study, builds on previous tissue clearing processes that have revolutionized anatomical research.
While scientists have attempted to create see-through organ and tissue samples since the 1800s, researchers have relied primarily on the sectioning of samples - slicing organs into extremely thin cross sections and examining these pieces in succession.
"That's been useful but it's also been slow and tedious," said senior study author Viviana Gradinaru, an assistant professor of biology and biological engineering at Caltech.
Recent advancements in tissue clearing have enabled researchers to study...Read more
The Food & Drug Administration on Thursday announced it would step up its regulation of a class of lab tests that have been key in ushering in an era of personalized medicine -- a step the agency has long considered against strong opposition by small labs.
Penalty kick shootouts are not a goalkeeper’s favorite way to settle a soccer match. Alone in the net, goalies must face off against a string of kickers and try to anticipate which way the ball will come hurtling toward the goal. Psychologists have long recognized that shots happen too fast for goalies to react after the ball leaves the kicker's foot — they just have to dive and hope for the best. But now, a new study suggests they do so in predictable ways that clever shooters could use against them.
The study, published Thursday in the journal Current Biology, looked at every shootout in every World Cup and Euro Cup tournament between 1976 and 2012. They found that goalkeepers suffered from a widespread misconception known as the "gambler’s fallacy": the more often one thing happens, the more you anticipate its opposite to occur, even though the likelihood of either remains the same.
For goalkeepers in a shootout, this meant the more times kickers booted the ball to one side of the...Read more
It’s official: The Mars 2020 rover’s instruments have been chosen, and they include a super-laser and stereo vision!
This successor to NASA’s Mars rover Curiosity may have the same skeleton as its predecessor, but its suite of scientific tools will take its exploration to the next step: looking for bio-signatures – actual signs of past life.
The Mars 2020 rover builds on the successes of Curiosity, known formally as the Mars Science Laboratory, which landed in Gale Crater in 2012. The high-tech robotic geologist chewed up and digested it in a chemical analyzer, discovering that the Red Planet once hosted habitats that were friendly to living things.
The new rover would build on those discoveries, looking to see whether there are any direct signs of life. It would also gather and cache valuable samples for another future spacecraft to pick up.
“How do we find bio-signatures? That’s not so easy. It’s difficult here on this planet,” Michael Meyer, lead scientist for NASA’s Mars...Read more
Dozens of the nation’s leading conservation scientists on Thursday expressed strong concern over a U.S. Fish and Wildlife Service official’s order to override a recommendation by federal biologists that wolverines deserve threatened species status.
In letters to the agency and the Interior Department, the scientists urged the agency to uphold the recommendation that protection for the 300 wolverines in the continental United States is warranted because climate change is shrinking remaining alpine habitat and spring snowpack for building sheltered dens to raise their kits.
USFWS Director Dan Ashe is expected to make a final determination on the matter Monday.
A letter sent on behalf of the Society for Conservation Biology and the American Society of Mammology said that the order to quash the recommendation “demonstrates a serious flaw in the FWS’ listing determination process.”
Shaye Wolf, climate science director of the Center for Biological Diversity and one of 56 scientists who...Read more
There’s a saying going around that sitting is the new smoking. It’s a bit snarky and perhaps a none-too-subtle dig at those of us who spend a lot of time on our rear ends for work and pleasure. But Dr. James Levine, who is credited with it, is dead serious. In fact, he says, sitting could be worse than smoking.
What to do about it? “Get Up!” is the title of Levine’s new book, a jovial tale of how he came to the scientific conclusion that our chairs are killing us and what can be done to stop the threat.
We lose two hours of life for every hour we sit, writes Levine, director of the Mayo Clinic-Arizona State University Obesity Solutions Initiative and inventor of the treadmill desk. Sitting all day is not natural and to blame for all kinds of ailments, including obesity, he says.
“We have created for ourselves a modern way of living that clashes with the way we’re meant to be,” he writes.
So the obvious answer is to move more, by, for example, taking walks after meals, something Levine...Read more
As they reached adulthood, female mice who were exposed in utero and just after birth to the pesticide DDT showed metabolic changes that put them at greater risk for obesity and type-2 diabetes, a new study says.
The metabolic abnormalities seen in the exposed female mice were dramatically exacerbated when they were fed a high-fat diet for 12 weeks in adulthood. Compared with unexposed mice who also ate a high-fat diet, females exposed to DDT around the time of their birth were more likely to develop high cholesterol, insulin insensitivity, glucose intolerance and metabolic problems that could lead to liver disease.
The study, published Wednesday in the journal PLoS One, helps explain a consistent finding from epidemiological studies: In large populations, exposure to DDT and other persistent organic pollutants, or POPs, is linked to increased rates of type-2 diabetes, obesity and worrisome cholesterol.
Such studies could not establish a cause-and-effect relationship between pesticide...Read more