Children are often fussy eaters, and most parents would say that trying to convince them that a given food is good for them won't help convince them to eat it. As it turns out, "won't help" might be overstating things. When told that a food serves some purpose other than tasting good, kids will rate it as less tasty and eat less of it.
Two Chicago-area researchers, Michal Maimaran and Ayelet Fishbach, phrase their research in terms of what they call "food instrumentality"—the idea that a given type of food is good for achieving a goal. Carrots are good for your vision, spinach makes you strong, and so on. The researchers suspect that this idea interacts with a quirk in the reasoning of young children: they tend to think of things as only serving a single purpose. If carrots are good for your vision, the reasoning goes, they're not likely to be good for your tastebuds at the same time.
Over a series of experiments with children three to five years old, the authors tested foods that were given various purposes: makes you strong, helps you read, or helps you count. In each case, the same foods were offered to a set of control children without any message. By a variety of measures, a positive message about the food undermined the cause: the children rated it as less tasty, planned on consuming less, and actually did consume less when they were given the chance to eat it.
The discovery of so many exoplanets in recent years has raised many new questions, forcing us to reexamine some of our ideas. Scientists had extrapolated models of stellar system evolution from our own Solar System, assuming that others look very similar to our own. But extrapolation can only get us so far. Scientists never expected to find so many “hot Jupiters”—gas giants larger than Jupiter and orbiting very close to their star.
We’re also having a hard time understanding the inner workings of exoplanets and stars with much greater mass than Earth. Scientists have managed to test some materials under extreme pressures and found that our conventional ideas about a material’s behavior may not apply. Certain exotic quantum mechanical models could apply in such extreme cases, but until recently, scientists have not been able to test those models’ predictions.
The difficulty, of course, is that actually visiting the cores of gas giants to test our understandings is wildly impractical. The next best thing, then, is to recreate these massive pressures on Earth and study their effects on materials. As impossible a task as it may seem, scientists at the National Ignition Facility (NIF) used its enormous lasers to do exactly that.
Today, NASA announced that it's issuing a Request for Information that seeks parties, either academic or commercial, who are willing to set up a communications relay orbiting Mars. Should the agency like the information it gets, it could extend its current fee-for-service approach well beyond Earth's orbit.
Because of weight and power restrictions, the hardware that we've landed on Mars can't carry high-bandwidth communication devices that can reach Earth (it does, however, carry lower-bandwidth hardware that can establish a direct connection). Instead, missions like the Mars Reconnaissance Orbiter, which has its own science instruments, also carry communications hardware that lets them receive high volumes of data from the planet's surface and quickly send it back to Earth.
MRO is the most recent hardware that serves this purpose, but it's already nearly a decade old; Odyssey, its fellow relay, is even older. Fortunately, the MAVEN mission, which arrives this year, will also have relay capabilities, as will the ESA's ExoMars orbiter, which should arrive in 2016.
With all the attention given to every nuance of climate data, areas of research that would have never attracted much public interest sometimes find themselves in the spotlight. So it is with the process of measuring sea ice cover. People pay careful attention because it appears to be a leading indicator of climate change. In the Arctic, where the warming has been most intense, sea ice is retreating rapidly, with record lows having been set every few years over the past decades.
But at the other pole, Antarctic sea ice has been steadily expanding, creating a bit of a conundrum for scientists. They've come up with a variety of explanations for why the two poles might be behaving differently but, in the mean time, people have latched on to the difference to question our understanding of climate change.
Now, a paper has come out questioning whether the difference between the poles is as dramatic as it seemed. The reason for the potential difference? Measuring sea ice is remarkably hard.
Large galaxies such as the Milky Way appear to have been built by repeated mergers of smaller ones, but not every small galaxy has ended up being swallowed completely by a large one. The Milky Way is orbited by dozens of dwarf galaxies, some of which have been disrupted and stripped of stars, while others may have slipped into orbit largely intact. Similar dwarf galaxies orbit our nearby neighbors, including Andromeda.
Based on what we know about these mergers and computer modeling of galaxy formation and growth, the collection of dwarfs should be an unruly lot, having approached the galaxy they orbit from directions that are essentially random. Yet the dwarfs orbiting the Milky Way largely inhabit a single plane, orbiting in a manner analogous to moons around a giant planet.
It's easy to dismiss that as a fluke of chance, but that became a bit harder to do as evidence built over the past several years that most of Andromeda's dwarf galaxies were also organized into a single plane. Stranger still, that plane's edge is oriented toward the Milky Way. Now, a French-Australian team of astronomers has figured out a way to search existing data for the presence of planes farther out from the Milky Way, finding that Andromeda's setup is actually quite common.
Polls relating to publicly controversial scientific issues often trigger a great wailing and gnashing of teeth from science advocates. When large proportions of a population seem poorly informed about evolution, climate change, or genetically modified foods, the usual response is to bemoan the state of science literacy. It can seem obvious that many people don’t understand the science of evolution, for example—or the scientific method, generally—and that opinions would change if only we could educate them.
Research has shown, unfortunately, it's not that simple. Ars has previously covered Yale Professor Dan Kahan’s research into what he calls “cultural cognition,” and the idea goes like this: public opinion on these topics is fundamentally tied to cultural identities rather than assessment of scientific evidence. In other words, rather than evaluate the science, people form opinions based on what they think people with a similar background believe.
That shouldn’t come as a shock, especially given the well-known political or religious divides apparent for climate change and evolution.
As part of its normal life cycle, HIV inserts a copy of itself into the genome of every cell it infects. Most of these copies go on to cause an active infection, pumping out new copies of the virus. A few of them, however, go quiet and can persist even during aggressive antiviral treatments. These infected cells act as a reservoir for the virus, reestablishing an active infection if antiviral therapies are ever stopped. Eliminating this viral reservoir has proven extremely difficult.
Now, researchers are reporting on some of the first tests of a technique that targets the copies of the virus that are lurking in cells with a quiescent infection. Using a system that bacteria utilize to disable viruses, they've shown that it's possible to precisely edit out key HIV DNA sequences, essentially inactivating any copies of the virus. And if placed in cells prior to exposure to HIV, the same system effectively blocks infection.
Bacteria don't have an immune system, but that doesn't mean they have no defenses against viruses. When infected, the bacteria can make special RNAs that match the DNA sequences of the virus. These RNAs then guide a protein called Cas9 to the viral DNA, which the protein then cuts. The cut inactivates the virus, protecting the bacteria. The whole system (called CRISPR/Cas) is incredibly flexible; given the right RNA, it can be turned loose on pretty much any DNA sequence. Researchers have shown that it can be used to cut the DNA of living human cells, effectively editing their contents.
There’s no need to ask what the appeal of Arches National Park is—it’s in the name. The gorgeous sandstone arches there seem almost impossible. How and why should the relentlessly erosive wind carve such a fantastic structure? The arches seem too vulnerable, too artificial.
And arches aren’t the only trick that sandstone has up its sleeve. Bizarre, mushroom-shaped pillars seem even more absurd, as if they were carefully placed by an incredibly patient and even more incredibly strong Zen garden enthusiast. In some places, networks of sandstone pillars even hold up ledges like a miniature Moria.
We know plenty about how this erosion takes place, and some details about why some sections of the rock erode faster than others, but the primary cause of these shapes has eluded geologists. A new study led by Jiri Bruthans of Charles University in Prague has revealed a surprisingly simple explanation.