Even with 15 percent of their hearts removed, newborn mice possess the extraordinary ability to mend themselves, researchers report today in the journal Science. It’s the first time that mammals outside of the womb have shown the regenerative ability to repair the heart.
Only newborn mice could regenerate part of their hearts, and they lost this ability after about a week after birth. Still, the results were quite impressive: Olson’s team removed 15 percent of the heart one day after birth, and when the researchers checked up three weeks later, the whole heart was repaired in 99 percent of the mice. Until now, scientists had seen fish and amphibians regenerate heart tissue as adults, but only embryonic mammals had been spotted doing the same.
“When a person has a heart attack and heart muscle cells are lost, the heart loses pump function, causing heart failure and eventual death,” said Eric Olson, a molecular biologist at Southwestern Medical Centre in Dallas, Texas. “Now that we know that the mammalian heart indeed possesses the potential to regenerate, at least early in life, we can begin to search for drugs or genes or other things that might reawaken this potential in the adult heart of mice and eventually of humans.” [The Guardian]
First they have to understand what the newborn rodent’s bodies are up to. Initially, Olson and colleagues weren’t sure how the mice were mending themselves—with stem cells, or cells that had already become muscle cells. But the appearance of the cells gave them away, says Dr. Stephen Badylak, who wasn’t involved in the study.
From across the pond comes a ravishing collection of scientific imagery. The Wellcome Collection, a London museum, has just announced the winners of its Wellcome Image Awards.
The 21 award winners, selected from images acquired by the Wellcome Collection over the last 18 months, were chosen both for their ability to enhance scientific understanding and for their aesthetic appeal. Many use colour to better illustrate hard-to-see features. [New Scientist]
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Sandfish lizards jostle back and forth, bending their bodies into a slithery S-curve to swim through the sands of the Sahara. Like scorpions and several other native desert species, they long ago mastered the difficult art of moving through the myriad grains of a sandy expanse to escape predators or the blistering African sun. And now physicists are close to cracking their secrets.
Daniel Goldman’s team has been trying to figure out just how the sandfish lizards do it for years now; in 2009 they built a robot to simulate the creature’s slithering motion. This time, for a study in the Journal of the Royal Society Interface, the scientists tried to model the physics of an animal knocking around so many grains of sand and see how the lizards burrow with such efficiency.
The team found sine-wave-like movement allows the lizard, and their robot, to push forward in sand, but creating computer models for the experiments proved problematic. Simulating all of the tiny sand grains required a lot of money to purchase time on powerful computers. So, the team performed the same experiments using 3-millimeter-wide glass beads instead of sand. “We wanted something easy to simulate that had some predictive power. We got lucky, because it turned out [the lizard and robot] swim beautifully in the same way through larger glass beads,” Goldman said. [Wired]
If a vaccine injures a child, should the parents be allowed to sue in state court? That’s a question lawyers, vaccine makers, parents, and Congress have wrestled over for a quarter century. This week, the United States Supreme Court brought forth a ruling that keeps the status quo: No, you can’t.
The justices, voting 6-2, said a 1986 federal law preempts claims that a drugmaker should have sold a safer formulation of a vaccine. The law, designed to encourage vaccine production by limiting patient suits, channels most complaints into a company- financed no-fault system that offers limited but guaranteed payments for injuries shown to be caused by a product. [Bloomberg]
The case in question, which has been kicking around for nearly two decades, was brought by Russell and Robalee Bruesewitz on behalf of their daughter, Hannah. In 1992 she began experiencing seizures after receiving a diphtheria, pertussis and tetanus shot made by Wyeth [part of Pfizer]. At the time, her parents tried to file a claim with that government-created system.
When a special Vaccine Court within the Court of Federal Claims ruled that her injuries couldn’t be linked with the vaccine, her parents tried to move the case to Pennsylvania state court. The Third Circuit Court of Appeals eventually ruled that the claim was pre-empted by federal law, a decision upheld by the Supreme Court. [Wall Street Journal]
Around 520 million years ago, a walking cactus roamed the Earth. Its body had nine segments, each bearing a pair of armour-plated legs, covered in thorns. It was an animal, but one that looked more like the concoction of a bad fantasy artist. Jianni Liu from Northwest University in Xi’an discovered this bundle of spines and named it Diania cactiformis – the “walking cactus from Yunnan”. And she thinks that it sits at the roots of the most successful group of animals on the planet.
If Liu is right, Diania is one of the earliest relatives of the arthropods – the group that includes insects, spiders, crabs, and more. These species all share a segmented body, a hard external skeleton and jointed legs. They are life’s winners, the most diverse of all animal groups.
For plenty more about this weird ancient armored creature, check out the rest of Ed’s post at Not Exactly Rocket Science.
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The last NFL season was dominated by worries about concussions and other head injuries more than any before, but it ended on an upbeat note when Green Bay Packers quarterback Aaron Rodgers shook off two regular season concussions to win Super Bowl MVP honors. But after the bright lights go down, the long-term effects of brain injuries linger in the dark. And no one, it seems, knew that better than Dave Duerson.
Duerson played 11 seasons as a battering ram, a safety for the Chicago Bears and New York Giants. Last week he committed suicide, thrusting the worries about the long-term consequences of repeated blows to the head back into the spotlight.
When the 50-year-old former NFL safety and successful entrepreneur shot himself in the chest, there was another purpose: so that his brain could be donated to Boston University researchers and studied to assess the life-long neurological effects of playing in the National Football League. [Wired]
According to reports, Duerson made sure to get his final message across. He texted family members on the day of his death that he wanted his brain to go to the center, and to be sure he was heard, he left behind a paper note reading “Please, see that my brain is given to the NFL’s brain bank.”
When it come to dinosaurs, names say a lot: “tyrant lizard king” sums up the towering stature and carnivorous ways of Tyrannosaurus rex, and “arm lizard” gestures toward the Brachiosaurus‘s long front legs. And the same is true for the newest discovered dinosaur species, which has been dubbed “thunder-thighs.” That’s because scientists think its muscular thighs were so strong that it used them to boot its enemies.
The official name of this new sauropod species is Brontomerus mcintoshi. The first name is Greek for “thunder-thighs,” and the species name honors the Wesleyan University physics professor and amateur paleontologist Jack McIntosh. This dino is believed to have bigger leg muscles than any other sauropod.
A team of American and British scientists discovered the dinosaur in a quarry in Utah, and published their findings in the journal Acta Palaeontologica Polonica. Fragments from two skeletons were found: one from an adult (believed to be the mother) and a juvenile. These specimens are roughly 110 million year old, and the larger one would have weighed in at six tons and measured over 45 feet long.
When you engage in a long cell phone conversation, a new study says, the phone radiation may increase the brain activity in regions nearest to the antenna. It’s the newest entry into the long-running debate about whether cell phones carry health risks, but the scientists behind the research in the Journal of the American Medical Association caution that they don’t know what this localized change in brain activity means—or even how it’s happening.
Many previous studies of cell phone safety have looked into the question of whether the phones’ radiation could cause cancer (there’s no solid evidence that it could) or looked at the effects of the heat that phones create. But Nora Volkow and colleagues investigated something else: The metabolism of the brain regions nearest to the phone—that is, how quickly they are burning energy. To do it, Volkow’s team recruited 50 people and subjected them to PET scans while an active cellphone sat next to their heads.
To blind the participants, the authors strapped two cell phones on their heads, one to each ear (the cellphone used in this work is a standard Samsung CDMA flip phone). Both were kept muted, and only one was activated by a call—the side that was activated was flipped in two different recording sessions. The calls started 20 minutes before a dose of radioactive glucose, and kept going for a half an hour afterwards to provide a long-term picture of metabolic activity. The data from one of the subjects ended up not being used because the cell company dropped the call. [Ars Technica]
As BP’s oil gushed into the Gulf of Mexico week after week last summer, we got accustomed to wildly different estimates for how quickly the oil was leaking and how much entered the gulf. Now, 10 months after the mess began, government and independent scientists have wildly different estimates for how much of the oil remains.
Oceanographer Samantha Joye, speaking at the American Association for the Advancement of Science annual conference in Washington this weekend, revealed the findings of her trips to the Gulf to study the seafloor. In December she dove to areas around the site of BP’s well blowout, finding—and photographing—layers of gunky hydrocarbons. The oil was up to inches thick in places.
“Magic microbes consumed maybe 10 percent of the total discharge, the rest of it we don’t know,” Joye said, later adding: “there’s a lot of it out there.” [AP]
To explain how so much oil got down to the seafloor, Joye’s team did an experiment when they got back to the lab. Joye put a dab of oil from the BP well into a vial of water taken from nearby in the Gulf, then watched.
After just one day, naturally occurring microbes in the water began growing on the oil. After a week, the cells formed blobs, held together by spit, that were so heavy they began sinking to the bottom of a jar. Two weeks later, large streamers of microbial slime and cells were evident. Brown dots visible inside the mix were emulsified oil. “This is the mechanism that we propose deposited oil to the [Gulf’s] bottom,” Joye said. [Science News]
In the realm of meteorology, bats, birds, and insects are usually considered “animalas non grata,” since they create unwanted noise in the Doppler radar readouts used to study storms. But now, thanks to better radar station networking and the sharing of unfiltered data, ecologists have realized that these radar systems can be used as powerful animal tracking tools.
At last week’s American Association for the Advancement of Science meeting, researchers Thomas Kunz, Winifred Frick, and Phillip Chilson explained how Dopplar data can be used by ecologists. They call their new discipline aeroecology.
This melding of meteorology and ecology started with an “Aha!” moment:
“Dr Kunz and I were meeting Dr Chilson about a year ago over breakfast and they kept talking about the ‘QPE’, and finally I asked what it is,” Dr Frick told the meeting. It stands for quantitative precipitation estimator — a numerical method to measure how much rain there is in a storm front. “I paused and said, ‘you can estimate the number of raindrops in a raincloud? Do you think we could estimate the number of bats in a bat cloud?'” To calibrate their experiment, the team took a bat into a chamber where the degree to which it reflects radio waves could be measured. “From those measurements and using radar, we’ve been able to adapt those QPE measurements to a ‘QBE’ – a quantitative bat estimator,” Dr Frick said. [BBC News]