Water, water everywhere. Another pass of Saturn’s moon Enceladus, made by the Cassini spacecraft last November, shows at least 30 geysers blasting water from the moon’s south pole. That’s 20 more than were previously known at that location. In addition, the most detailed infrared map of one of the south pole’s fissures, where jets emanate, indicates that the surface temperature there might be as high as 200 kelvins (-73º Celsius), or about 20 kelvins warmer than previously estimated [Discovery News]. Cassini drew to within about 1,000 miles of Enceladus to measure this geological feature, which is a fracture–one of the moon’s so-called “tiger stripes”–about a quarter-mile deep officially called Baghdad Sulcus.
While 200 kelvins is still a frigid temperature for we humans, research team member John Spencer said it could make a big difference on Enceladus. “The huge amount of heat pouring out of the tiger stripe fractures may be enough to melt the ice underground,” Spencer said. ”Results like this make Enceladus one of the most exciting places we’ve found in the solar system” [Wired.com].
Bad Astronomy: Enceladus Is Erupting!
80beats: Cassini Probe Finds “Ingredients For Life” on Saturn’s Moon Enceladus
80beats: Antifreeze Might Allow For Oceans—And Life—On Enceladus
80beats: Does Enceladus, Saturn’s Geyser-Spouting Moon, Have Liquid Oceans?
80beats: New Evidence of Hospitable Conditions for Life on Saturn’s Moons
80beats: Geysers From Saturn’s Moon May Indicate Liquid Lakes, and a Chance for Life
80beats: Cassini Spacecraft Snaps Pictures of Saturn’s Geyser-Spouting Moon
In summer 2008, DISCOVER set sail for the Great Pacific Garbage Patch, that Texas-sized soup of tiny plastic bits that might now be an intractable mess in the middle of the ocean. With appearances in newspapers, magazines, and even “Good Morning America,” the Pacific patch became the newest target for environmental hand-wringing, and raised questions over whether it would even be possible to clean up. However, the ocean currents that cause the Pacific gyre don’t just happen in the North Pacific. Scientists at the Sea Education Association just finished a two-decade-long study of the North Atlantic and found similarly sad results.
The team dragged nets half-in and half-out of the water to take a trash census. The researchers carried out 6,100 tows in areas of the Caribbean and the North Atlantic — off the coast of the U.S. More than half of these expeditions revealed floating pieces of plastic on the water surface [BBC News]. Like the Pacific gyre, the Atlantic one—located mostly between 22 and 38 degrees north latitude—contains a dizzying number of small plastic pieces that used to be bags, bottles, and other consumer products. Lead researcher Kara Lavendar Law says it’s difficult to compare the two, but researchers in both places collected more than 1,000 pieces during a single tow of a net [The New York Times].
An Italian court in Milan has just convicted three Google executives of criminal charges. The court found them liable for an online video that they did not appear in, film, or have any role in posting, and which the company promptly removed when complaints about it were raised. The Italian court, however, still held them responsible for the video and sentenced them to suspended six-month sentences. Experts say the case sets a dangerous precedent, and could dramatically restrict online content in Italy.
Thousands of people post videos each hour on YouTube and Google Video, and various court cases have questioned whether Google, which owns YouTube, is liable for every video that infringes on someone’s copyright or is deemed offensive to its viewers. Google has argued that it’s only liable if offensive material stays up on its site despite complaints against it, and says that if the company takes complained-about videos down, it has no legal liability–like the rules it faces under U.S. law. Italy apparently disagrees.
The case pertains to a video that was posted to Google Video in 2006 showing four youths in Turin bullying a 17-year old who suffers either from Down Syndrome or autism (reports vary). The video received 12,000 views before the Italian police brought it to Google’s notice. The company immediately took it down, and Google then helped the cops find the person who uploaded it, resulting in the identification (and school expulsion) of the four bullies. But the Google executives, who include David Drummond, Google’s senior vice president and chief legal officer, and George Reyes, Google’s former chief financial officer, were charged and convicted for criminal defamation and a failure to protect the privacy of the bullied teen.
Dinosaurs and explosives—science stories don’t get much cooler than this.
Researchers in Utah have excavated two complete and two partial skulls of a dino called Abydosaurus mcintoshi, a 105-million-year-old sauropod, which the scientists think might have descended from the brachiosaurus family. “It is amazing. You can hold the skull in your hands and look into the eyes of something that lived a very long time ago” [USA Today], says paleontologist Brooks Britt, co-author of the study that appeared in the journal Naturwissenschaften.
Click through the photo gallery for more pictures from the dig, and for the whole story.
Image: Brigham Young University
Forgetting an umbrella or the location of a parking spot may be annoying, but scientists have suggested that for healthy brains to function well, they need to forget. By forgetting, scientists say, the brain makes space for new memories. In an intriguing breakthrough, researchers from the United States and China have identified the protein responsible for forgetting in fruit flies. By tweaking a protein called Rac, researchers were able to speed up and slow down the erasure of painful memories [New Scientist]. The findings were published in the journal Cell.
Scientists have been unable to pinpoint why people forget. Some have suggested that new memories are ephemeral and vanish over time, while others thought that interference caused earlier short-term memories to be overridden as new information comes in [Science Daily]. While both of these notions seem to suggest that forgetting is a passive mechanism, the new study suggests that forgetting is far more active, and that Rac works to inhibit the formation of more long-term memories.
For everyone out there who’d like to hear a little less of their amorous neighbors, not to mention their kid badly playing the violin, there may be hope: Hong Kong scientists have devised a delightfully simple material made of latex and plastic that they say could one day reduce the racket at noisy places like airports. The paper appears in Applied Physics Letters.
Zhiyu Yang and colleagues devised a system of thin tiles that, when assembled into a large sheet, could cancel out noise in a huge range, including the bass frequencies that tend to breach the walls of our apartments and houses with ease. Each panel is just three millimeters thick, and less than half an inch wide, with the weighted plastic button in the middle. When sound waves hit the panel, the membrane and weighted buttons resonate at difference frequencies. “The inner part of the membrane vibrates in opposite phase to the outer region,” says Yang. That means the sound waves cancel each other out and no sound gets through [New Scientist]. Read More
It’s a big year for South Africa: Less than four months remain until the first matches of the World Cup, when much of the planet’s attention will turn to the country. But being under the spotlight of international sport makes it difficult to hide a country’s less glamorous bits, as China and Canada have found out trying to shield pollution and addiction problems from the glare of the last couple Olympiads. In June, the microscope will turn to South Africa and its ongoing AIDS crisis.
This month one of the country’s health leaders has renewed his call for blanket HIV testing and anti-retroviral drug dispersal to all patients, which he says can stop the AIDS epidemic once and for all–without having to find a vaccine against the virus or a cure for the disease.
Brian Williams’s idea isn’t new. The former World Health Organization figure, who is now one of South Africa’s top health officials, came out with a paper more than a year ago explaining his model for how effective universal testing and immediate therapy could be. But this week at the American Association for the Advancement of Science meeting in San Diego he expounded on his proposal: “The epidemic of HIV is really one of the worst plagues of human history…. I hope we can get to the starting line in one to two years and get complete coverage of patients in five years. Maybe that’s being optimistic, but we’re facing Armageddon” [The Guardian].
Sure, creatures that reproduce asexually get to avoid some of the hangups that come with sex, but the strategy brings its own problems. First and foremost, how do you prevent genetic deterioration without the fresh infusion of new genes that results from the mixing of male and female DNA? For the all-female whiptail lizard, the solution is to hedge its bets.
In a study forthcoming in Nature, researcher Peter Baumann found that each whiptail lizard egg cells contains twice the number of chromosomes you’d expect. In the fertilized egg cell of a sexually reproducing lizard species, you’d expect to see much what you see in humans—23 chromosomes from the father and 23 from the mother combining into 46. (Most human cells contain 46 chromosomes, but egg and sperm cells contain only 23, so that they can combine to give an offspring a compete, but genetically new, set of chromosomes.)
But the whiptail eggs instead begin with two identical copies of each of their mother’s chromosomes, for a total of 92. Those chromosomes then pair with their identical duplicates, and after two cell divisions, a mature egg with 46 chromosomes is produced. Since crossing-over during the cell divisions occurs only between pairs of identical chromosomes, the lizard that develops from the unfertilized egg is identical to its mother [The New York Times].
Late last year, a Belgian man in his mid-forties created a media stir when doctors announced that he had been misdiagnosed as being in a coma for 23 years. Rom Houben, the victim of a horrific car-crash in the eighties, was incorrectly diagnosed as being in a “persistently vegetative state.” But by using new diagnostic tests and brain scans that were unavailable in the eighties, scientists revealed that Houben was actually conscious.
Reports then breathlessly announced that Houben could also finally “communicate,” expressing his thoughts by having his hand supported by his therapist who reportedly helped him tap out his messages on a touch-screen computer. “I shall never forget the day when they discovered what was truly wrong with me,” Houben apparently tapped. “It was my second birth. I want to read, talk with my friends via the computer and enjoy my life now that people know I am not dead” [The Guardian].
But now one of Houben’s doctors, neuroscientist Steven Laureys, has declared the Belgian hasn’t been communicating after all.
When the story first broke, DISCOVER and other discerning publications noted that this type of communication, called “facilitated communication,” is very controversial, and has repeatedly failed under conditions of rigorous testing. [Psychology Today]. Skeptics argued that the facilitated communication therapist brought in by Houben’s family was really guiding the man’s hand and choosing which letters to press herself. Skeptics who read Houben’s messages were also amazed that someone who was in a minimally-conscious state for more than two decades was so lucid, articulate, and forgiving of the medical staff. Laureys wanted to study the case further to determine if Houben could indeed communicate.
If you can’t say it, then sing it! Experts researching patients who have lost their ability to speak after a stroke are now suggesting that they could be able to communicate with music using Melodic Intonation Therapy (MIT). Using MIT, the scientists showed that patients who were earlier communicating only in mumbles and grunts could now learn to sing out basic phrases like “I am thirsty.”
The study was conducted by Harvard Medical School neurologist Gottfried Schlaug on 12 patients whose speech was impaired by strokes, and showed that patients who were taught to essentially sing their words improved their verbal abilities and maintained the improvement for up to a month after the end of the therapy [Wall Street Journal]. Schlaug presented these findings at the meeting of the American Association for the Advancement of Science in San Diego.