Archive for March, 2009

Humans Cared for "Special-Needs" Kids 500,000 Years Ago, Say Researchers

By Rachel Cernansky | March 31, 2009 3:43 pm

skull.jpgThe oldest known fossil of a human child with a skull deformity has been discovered, suggesting that early humans did not kill or abandon their abnormal offspring, as has been commonly assumed. A research team reconstructed the 530,000-year-old skull, the first pieces of which were unearthed in Spain in 2001, and determined that the child likely suffered from craniosynostosis, a debilitating genetic disorder in which some pieces of the skull fuse too quickly, causing pressure to build in the brain [Wired] and interfering with brain development. The severity of the deformity is not clear, but researchers say the child probably had learning difficulties and other mental health issues, and certainly would have required extra care.

The child belonged to the species Homo heidelbergensis, who lived in Europe 800,000 years ago and may have been the direct ancestors of Neanderthals. Humans are thought to be unique in the way they care for sick individuals. Researchers call it conspecific care, but most laypeople would probably call it compassion. Other primates don’t display similar behavior, so we know humans evolved the ability at some point, even if scientists can’t quite pinpoint when. The work could mean that humans as far back as half a million years ago had differentiated from our primate ancestors [Wired].

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CATEGORIZED UNDER: Human Origins, Mind & Brain

Six Volunteers, Living in a Tin Can, Will Simulate a Trip to Mars

By Eliza Strickland | March 31, 2009 1:48 pm

Mars isolation experimentToday four Russians, a German and a Frenchman walked into a mocked-up spacecraft and swung the metal hatch shut behind them. If all goes as planned, that hatch won’t open again for 105 days. The six men have volunteered to spend more than three months in isolation to simulate the experience of a manned flight to Mars. The crew will subsist on freeze-dried space rations and will clean themselves with wet wipes; they’ll also go without smoking, alcohol, TV, and internet. Their only link to the outside world will be communications sessions with the mission control and an internal e-mail system. Communications with the mission controllers will have 20-minute delays to imitate a real flight [AP].

This project is a warm up for a much more ambitious experiment, scheduled for December, which will see another group of volunteers spending over 500 days in the same conditions. With current technology it is estimated that a return trip to Mars would take at least 18 months [Telegraph].

The current experiment won’t simulate some of the most daunting obstacles to interplanetary travel, like increased radiation exposure and the physical effects of prolonged weightlessness. Instead, it will focus on the psychological impact of isolation from the outside world and close proximity to just a few people. “Working in such conditions requires that a person be able to check himself, evaluate his condition in relation to the crew and in relation to mission control and be able to correct himself,” said Boris V. Marukov, the experiment’s director and a former crew member on the International Space Station. “He will be a psychotherapist for himself” [The New York Times].

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CATEGORIZED UNDER: Space

Is Baby Fat a Warning Sign? New Research Links Infants' Weight Gain to Obesity

By Eliza Strickland | March 31, 2009 10:05 am

baby measurementThe rate at which infants gain weight in the first six months of their lives is linked to those babies’ risk of becoming obese by age three, a new study has found. Researchers determined that sudden weight gain in early infancy was more important than how much a baby weighed at birth, the weight of the infant’s parents, or the number of pounds put on by the mother during pregnancy. “The perception has been that a chubby baby and a baby that grows fast early in life is healthier and all the baby fat will disappear,” said the paper’s lead author, Dr. Elsie Taveras…. “But [that] is not the case” [Chicago Tribune].

While the researchers note that early childhood obesity does not necessarily lead to obesity later in life, they say it does raise the risks. Obesity rates among U.S. children have doubled in the last 20 years, and almost a third of American children are either overweight or obese. The epidemic of obesity is linked to a host of health problems such as higher risks for heart disease, diabetes and cancer [Reuters].

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CATEGORIZED UNDER: Health & Medicine

Strife on the Space Station: Russians Can't Use the American Toilet

By Eliza Strickland | March 31, 2009 8:41 am

Padalka Russian cosmonautBureaucratic rules regarding who can use what equipment aboard the International Space Station are causing some hard feelings among the crew members, according to Russian cosmonaut Gennady Padalka, who gave an interview to Russia’s Novaya Gazeta newspaper before he blasted off towards the space station on Thursday. Padalka complained that regulations will prevent him from using his American colleagues’ exercise bike to stay fit in space. Worse than that, [officials] also ruled that American and Russian crew members should use their own “national toilets”, with Russian crew banned from using the luxurious American astro-loo [The Guardian].

Padalka said strict regulations that prevent the sharing of everything from food to toilets hurts the crew’s morale and makes working in space still more complicated. But he added that the crew will rise above the pettiness. “Cosmonauts are above the ongoing squabble, no matter what officials decide,” said Padalka, a veteran of two space missions, according to the newspaper. “We are grown-up, well-educated and good-mannered people and can use our own brains to create normal relationship. It’s politicians and bureaucrats who can’t reach agreement, not us, cosmonauts and astronauts” [AP].

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CATEGORIZED UNDER: Space

Finally, a Predator to Control the Notorious Cane Toad: Meat Ants?

By Rachel Cernansky | March 30, 2009 6:06 pm

canetoad.jpgResearchers in Australia think they have found a solution to the country’s toxic cane toad problem: make Australian meat ants eat them. Cane toads—which can grow up to 8 inches (20 centimeters) in length—were imported from South America to Queensland [in northeast Australia] in 1935 in a failed attempt to control beetles on sugarcane plantations. Trouble was, the toads couldn’t jump high enough to eat the beetles, which live on top of cane stalks [AP]. Since their introduction… cane toads have spread through most of tropical Australia, eating and poisoning native animals [New Scientist]. No one has been able to get their population growth under control, and past suggestions to do so by introducing exotic diseases have only raised concerns about causing as much harm as the toads have themselves.

But a research team led by ecologist Rick Shine found that cane toads are more vulnerable to being eaten by Australia’s predatory meat ants than are native frogs, which may allow the ants to be used as a “safe” biocontrol agent that would not interfere with native frog species. Shine said the team plans to try ways of encouraging meat ants to build colonies near toad breeding ponds. One way would be to plant trees the ants favour [The Australian]. He is hopeful the strategy will work because unlike native frogs, cane toads are active during the day, when meat ants roam about scavenging for food. Toads also tend to breed in ponds that are out in the open sun, which results in their young emerging onto bare, baked mud areas, a habitat where meat ants like to forage [Sydney Morning Herald]. The toad is also more vulnerable because it lays its eggs in the dry season when water is low and there’s little protective vegetation at the pond’s edge [The Australian].

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CATEGORIZED UNDER: Environment, Living World

Gorging on Omega-3 Shrimp Gives Birds Extra Endurance

By Eliza Strickland | March 30, 2009 5:13 pm

quailA migrating bird has found a quick and effective way to boost its endurance for a grueling task, according to a new study, and it’s a tactic that would make human marathon runners jealous–provided they like seafood.

Like all migrating birds, the tiny sandpiper instinctively heads to warmer climates for the winter. The [1,900-mile] trek from the birds’ summer home in the Canadian Arctic to the South American coast includes 3 days of nonstop flight over open water. The journey is so arduous it can kill younger or weaker members of the flock [ScienceNOW Daily News]. Sandpipers prepare for the flight in a number of ways: Autumn’s shorter days and cooler weather trigger hormonal changes in the birds, causing their stomachs to stretch to hold more food. The birds also start flying more, as if exercising for their upcoming ordeal.

But the final, and arguably most important step seems to be a stop at the Bay of Fundy, where sandpipers spend two weeks gorging on mud shrimp, which have some of the highest levels of omega-3 fatty acids of any marine animal. Researchers say the feast drastically increases the birds’ endurance by making their muscles use oxygen more efficiently. These omega-3 fatty acids are the same fats shown to reduce the risk of cardiovascular disease and lower blood pressure in humans [CBC]. 

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CATEGORIZED UNDER: Living World
MORE ABOUT: birds, migration, nutrition

Scientists Film HIV Jumping From Cell to Cell for the First Time

By Eliza Strickland | March 30, 2009 3:36 pm

HIV transmissionFor the first time, researchers have filmed the HIV virus spreading from one cell to the next, and they say the process by which it moves to an uninfected cell may provide a new target for future vaccines or treatments. The videos show how an infected immune system T-cell hooks up with an uninfected cell, and passes a packet of viral particles through a structure called a virological synapse.

For decades it was believed that HIV was mostly spread around the body through freely circulating particles, which attach themselves to a cell, take over its replication machinery and make multiple copies of themselves…. Due to this, previous efforts to create an HIV vaccine have focused on priming the immune system to recognise and attack proteins of free-circulating virus [Telegraph]. While researchers discovered cell-to-cell transmission through the virological synapse earlier this decade, researchers say the videos highlight the extreme efficiency of this transmission process.

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CATEGORIZED UNDER: Health & Medicine, Technology
MORE ABOUT: HIV & AIDS, viruses

Heightened by Halo: First-Person Video Games Are Good for Your Vision

By Eliza Strickland | March 30, 2009 10:20 am

Unreal TournamentWho says shoot-‘em-up video games are a waste of time? A new study has found that playing action video games dramatically increases the players’ ability to detect subtle shades of gray. Says lead Daphne Bavelier: “Normally, improving contrast sensitivity means getting glasses or eye surgery — somehow changing the optics of the eye…. [But when] people play action games, they’re changing the brain’s pathway responsible for visual processing. These games push the human visual system to the limits and the brain adapts to it,” Bavelier said [Reuters]. The study also found that more sedate games that don’t require precisely aimed actions, like The Sims 2, do not confer a similar benefit.

The researchers say that eye doctors could one day write prescriptions for Nintendo: The finding raises the prospect that people with amblyopia, which affects contrast perception, could be treated with games. A trial has begun to test that theory. Amblyopia, sometimes known as “lazy eye”, affects around 3 per cent of people in western populations and happens when the brain fails to correctly register signals from one eye [New Scientist]. Contrast sensitivity, which is crucial for activities such as night driving, is also one of the first elements of vision to be affected by aging.

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CATEGORIZED UNDER: Mind & Brain, Technology
MORE ABOUT: senses, video games, vision

Termite Queens Are Doin' It For Themselves

By Eliza Strickland | March 30, 2009 8:52 am

termitesWhile the Eurythmics and Aretha Franklin were singing about female empowerment in the human species, they’d probably approve of this termite queen’s activities. When it comes time for aging queens of the Japanese species Reticulitermes speratus to produce replacement queens, they don’t bother to mate with their king and instead produce their daughters asexually, in a process called parthenogenesis. Even when the queen dies, she maintains her genetic contribution to the colony. “This gives genetic momentum to the expression ‘Long live the queen'” [ScienceNOW Daily News], comments entomologist Barbara Thorne.

A termite colony starts when a king and queen pair up during an annual mating flight and settle down to start a family. At first, the couple produces worker and soldier termites that care for the nest. When the colony gets big enough, the king and queen start making alates–winged termites that leave home to find mates and start colonies of their own [ScienceNOW Daily News]. Finally, towards the end of her life, the queen has to produce several replacement queens to keep the colony going. In most species the king and queen mate to conceive these secondary queens, but that poses a problem before too long, when the king begins to mate with his daughters. This termite incest creates a next generation with reduced genetic diversity.

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CATEGORIZED UNDER: Living World

New Evidence for Ice-Spewing Volcanoes on Saturn's Moon Titan

By Eliza Strickland | March 27, 2009 5:33 pm

Titan cryovolcanoSaturn‘s moon Titan is already an object of fascination to astronomers: The moon has seasonal weather patterns, a thick atmosphere, and lakes of liquid methane on its surface, and some scientists think it’s one of the likeliest spots to find extraterrestrial life in our solar system. Now, researchers have found new evidence that the moon has cryovolcanoes, which, in the cold of the outer Solar System, would spew a slurry of ice and liquid hydrocarbons, instead of lava. “It’s as if it’s a sort of constant bubbling cauldron that occasionally explodes big time,” says Robert Nelson, a Cassini team scientist [Nature News].

The still-controversial theory regards an area of Titan called Hotei Arcus, which appears to fluctuate in brightness on timescales of several months…. The cryovolcanism idea was bolstered in 2008, when observations of Hotei Arcus by a radar instrument aboard NASA’s Cassini probe revealed structures that resembled lava flows [New Scientist]. The new findings, discussed at this week’s Lunar and Planetary Science Conference, are based on radar images taken by Cassini on recent flybys of the moon (radar is required to penetrate Titan’s thick methane atmosphere). Overlapping images were used to create a topographical map of Hotei Arcus; the map shows several lobe-like formations, more than 300 feet high, which researchers say resemble the oozing of a viscous, lava-like material.

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CATEGORIZED UNDER: Space
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