62324031
submission
sciencehabit writes:
It probably won’t come as a surprise that smoking a joint now and then will leave you feeling pretty good, man. But smoking a lot of marijuana over a long time might do just the opposite. Scientists have found that the brains of pot abusers react less strongly to the chemical dopamine, which is responsible for creating feelings of pleasure and reward. Their blunted dopamine responses could leave heavy marijuana users living in a fog—and not the good kind.
62270595
submission
sciencehabit writes:
Publishing is one of the most ballyhooed metrics of scientific careers, and every researcher hates to have a gap in that part of his or her CV. Here’s some consolation: A new study finds that very few scientists—fewer than 1%—manage to publish a paper every year. But these 150,608 scientists dominate the research journals, having their names on 41% of all papers. Among the most highly cited work, this elite group can be found among the co-authors of 87% of papers. Students, meanwhile, may spend years on research that yields only one or a few papers. “[I]n these cases, the research system may be exploiting the work of millions of young scientists,” the authors conclude.
62125249
submission
sciencehabit writes:
That metal ball that makes your hair stand on end at science museums may have a powerful new use. Scientists have found a way to combine these Van de Graaff generators with a common laboratory instrument to detect drugs, explosives, and other illicit materials on the human body. In the laboratory, scientists had a volunteer touch a Van de Graaff generator for 2 seconds to charge his body to 400,000 volts. This ionized compounds on the surface of his body. The person then pointed their charged finger toward the inlet of a mass spectrometer, and ions from their body entered the machine. In various tests, the machine correctly identified explosives, flammable solvents, cocaine, and acetaminophen on the skin.
62017955
submission
sciencehabit writes:
For decades, physicists have sought the sources of the most energetic subatomic particles in the universe—cosmic rays that strike the atmosphere with as much energy as well-thrown baseballs. Now, a team working with the Telescope Array, a collection of 507 particle detectors covering 700 square kilometers of desert in Utah, has observed a broad "hotspot" in the sky in which such cosmic rays seem to originate. Although not definitive, the observation suggests the cosmic rays emanate from a distinct source near our galaxy and not from sources spread all over the universe.
61986015
submission
sciencehabit writes:
Fossils unearthed at a construction project in South Carolina belong to a bird with the largest wingspan ever known, according to a new study. The animal measured 6.4 meters from wingtip to wingtip, about the length of a 10-passenger limousine and approaching twice the size of the wandering albatross, today’s wingspan record-holder. Like modern-day albatrosses, the newly described species would have been a soaring champ.
61974337
submission
sciencehabit writes:
When ground water saturates a river basin, the risk for flooding goes up. So does the strength of Earth’s gravity in that region, ever so slightly, because of the extra mass of the underground water. By using tiny variations in gravity detected from space, researchers report online today in Nature Geoscience that they can identify basins that are primed for flooding if additional rains come—sometimes with several months' warning.
61817745
submission
sciencehabit writes:
How much do we hate being alone with our own thoughts? Enough to give ourselves an electric shock. In a new study, researchers recruited hundreds of people and made them sit in an empty room and just think for about 15 minutes. About half of the volunteers hated the experience. In a separate experiment, 67% of men and 25% of women chose to push a button and shock themselves rather than just sit there quietly and think. One of the study authors suggests that the results may be due to boredom and the trouble that we have controlling our thoughts. “I think [our] mind is built to engage in the world,” he says. “So when we don’t give it anything to focus on, it’s kind of hard to know what to do.”
61814737
submission
sciencehabit writes:
A trove of fossilized footprints found in Alaska’s Denali National Park were left by hadrosaurs, commonly known as duck-billed dinosaurs. About 84% of the tracks were made by adult and near-adult hadrosaurs and 13% by young presumed to be less than 1 year old. A mere 3% of the tracks represent juvenile hadrosaurs, a rarity that strongly suggests the young of this species experienced a rapid growth spurt and therefore spent only a short time at this vulnerable size, the researchers report online this week in Geology. The presence of juveniles in the herd also strongly hints that these creatures spent their entire lives in the Arctic.
61814179
submission
sciencehabit writes:
Axinaea flowers offer a sugar-packed reward to visiting birds: the bellows organ, a bulbous, brightly colored appendage high in sugar and citric acid, which is attached to the plant’s male reproductive organ, or stamen. But as soon as the bird’s beak clamps down, the bellows organ forces air from its spongy tissues into a pollen chamber inside the stamen. The pollen explodes outwards, dusting the unwitting bird’s beak or forehead. When the bird flitted to another tree, it passes on the flower’s pollen to the receptive female organs of other flowers. This is the first case of a flowering plant offering up a food reward on a reproductive organ, the researchers report online today in Current Biology.
61781533
submission
sciencehabit writes:
A “superathlete” gene that helps Sherpas and other Tibetans breathe easy at high altitudes was inherited from an ancient species of human. That’s the conclusion of a new study, which finds that the gene variant came from people known as Denisovans, who went extinct soon after they mated with the ancestors of Europeans and Asians about 40,000 years ago. This is the first time a version of a gene acquired from interbreeding with another type of human has been shown to help modern humans adapt to their environment.
61779559
submission
sciencehabit writes:
The bladed, quill-like feathers of modern birds are essential for flight, and over millions of years they have become highly specialized for this purpose. But this may not be the reason they first evolved, say researchers studying an unusually complete fossil of the world’s first bird, Archaeopteryx. Instead, the team believes birds first grew these feathers for other purposes, such as insulation or mating display. The discovery raises the intriguing prospect that flight may have developed multiple times in the ancestors of birds.
61752347
submission
sciencehabit writes:
Watch a kangaroo in the Australian outback, and you’ll notice something strange—when they walk, they have five “legs.” As they graze on grasses and shrubs, they place their tails on the ground in time with their front legs, forming a tripodlike arrangement that supports their body while they bring their hind legs forward. Now, a study has shown that kangaroo tails are much more than just a passive crutch; they also play an active role in powering the animals’ unique, five-limbed walk. Evolutionarily, adding tails to their gait may have freed up kangaroos to reduce the size and weight of their forelimbs. That could have made the species’ famous bounding hops more efficient, helping them reach speeds of up to 60 kilometers per hour.
61752273
submission
sciencehabit writes:
In North America, they’re called Bigfoot or Sasquatch. In the Himalayan foothills, they’re known as yeti or abominable snowmen. And Russians call them Almasty. But in the scientific laboratory, these elusive, hairy, humanoid creatures are nothing more than bears, horses, and dogs. That’s the conclusion of a new study—the first peer-reviewed, genetic survey of biological samples claimed to be from the shadowy beasts.
61734643
submission
sciencehabit writes:
Thanks to a decade of programs geared toward giving people access to the necessary technology, by 2013 some 85% of Americans were surfing the World Wide Web. But how effectively are they using it? A new survey suggests that the digital divide has been replaced by a gap in digital readiness. It found that nearly 30% of Americans either aren’t digitally literate or don’t trust the Internet. That subgroup tended to be less educated, poorer, and older than the average American.
61695009
submission
sciencehabit writes:
Few scientists have ever seen the rare tufted ground squirrel (Rheithrosciurus macrotis), which hides in the hilly forests of Borneo, but it is an odd beast. It’s twice the size of most tree squirrels, and it reputedly has a taste for blood. Now, motion-controlled cameras have revealed another curious fact. The 35-centimeter-long rodent has the bushiest tail of any mammal compared with its body size.
