Category Archives: Nature

Researchers put pristine Antarctic peninsula at risk

Men and women wanted for hazardous duty. Small wages. Bitter cold. Long months of complete darkness. Compensations include off-road driving, penguin spotting and no-hassle waste disposal.

That could be a job advertisement for station staff at Fildes Peninsula Antarctic research stations. It’s not as noble as the apocryphal advertisement for explorer Ernest Shackleton’s expedition in the early twentieth century, which promised honour and recognition, but then some of the site’s modern occupants deserve neither, according to a report released last month by Germany’s Federal Environment Agency.

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Predictable evolution trumps randomness of mutations

Although mutations, the driver of evolution, occur at random, a study of the bacterium Escherichia coli reveals that nature often finds the same solution to the same problem again and again.

Over time, random mutations enable organisms to adapt and diversify, often when geographically separated groups of the same species grow better suited to their local environment and less like members of the other group.

But that’s not the only way that genetic diversity can arise. Researchers have reported cases of cichlid fish, palm trees and finches adapting to different ecological niches and splitting into different species despite living in the same place1–3. In 2008, evolutionary biologist Michael Doebeli of the University of British Columbia (UBC) in Vancouver and colleagues reported that E. coli bacteria can also diversify while sharing a test tube4.

In that study, they fed easy-to-digest glucose and a harder-to-stomach acetate to homogeneous populations of the bacteria, and let the bacteria chomp away. E. coli can switch between the two foods, but the team found that in each test tube two groups emerged, specialized in consuming either glucose or acetate. What they did not know was which genetic path each group took to achieve its specialisation.

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Scientific American also picked up the story [html]

European ministers back research-buddy plan

Europe’s leading scientific institutions could work with less-developed regions to create a new type of research centre, suggests a proposal backed by science ministers last week.

Under the ‘teaming’ proposal, the partners would put forward joint business plans to bid for European Union (EU) start-up funds as part of Horizon 2020, the EU research funding programme for 2014–20, which will replace the current Seventh Framework Programme (FP7) after it expires next year. Ministers gave their backing for the general structure of Horizon 2020 last June.

The less-developed host region would be expected to stump up long-term funding for the centres using either local money or other EU funds, and to enact administrative reforms if needed. The advising institution would provide management and networking expertise.

The EU Council approved its draft of the proposal on 11 December, but before the plan can go to a final vote at the European Parliament in 2013, the European Commission, Parliament and Council must all agree or ‘reconcile’ a draft blueprint.

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Ice may lurk in shadows beyond Moon’s poles

Water ice on the moon may be more widespread  than previously thought. Permanent shadows have been spotted far from the lunar poles, expanding the number of sites that would be good candidates for exploration by robotic rovers — or even for the locations of lunar bases.

Researchers have known for decades that the Moon’s poles host craters with lofty rims that shield their floors from sunlight, so searches for shadowed areas harbouring water ice have focused on the poles. But over the past few months, researchers have built a catalogue of permanently shadowed regions elsewhere on the Moon.

The team developed software called LunarShader to simulate lighting conditions on the Moon throughout its solar cycles. They fed in two topographical models — one from the Japanese spacecraft Kaguya, and one from NASA’s Lunar Reconnaissance Orbiter (LRO). The software identified about 100 craters that should contain permanent shadows, located as many as 58 degrees of latitude from the pole in both hemispheres, reported team member Joshua Cahill, a space scientist at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland, at the European Planetary Science Congress in Madrid this week. The result is being prepared for publication in Icarus, he said.

The findings are significant because they open “a much larger area where permanent manned stations could be established”, says Bruce Cutright, a hydrogeologist at the University of Texas at Austin. Water ice on the Moon exists in such low concentrations that any mission that seeks to study it, or to use it as a resource, will need a detailed map of its distribution.

Ice under ground

Cahill and his colleagues also took the candidate craters’ temperature using the LRO’s Diviner Lunar Radiometer instrument, to determine which sites are most likely to contain ice. The craters are only half the temperature of their better-lit surroundings, but they still reach an average of 175 kelvin — hot enough to boil water in the moon’s thin atmosphere — so any water ice must be insulated beneath the surface.

“While not as cold as the permanently shadowed regions near the poles, these non-polar areas offer a unique environment that may harbour volatiles,” says Emerson Speyerer, an engineer at Arizona State University in Tempe, who is part of another team that has identified persistent shadows at the lunar poles. That team is now characterizing other potential permanently shadowed regions using LRO data. They made a preliminary report at the March Lunar and Planetary Science Conference in The Woodlands, Texas.

Radar instruments on orbiting spacecraft allow some study of the ice, but close-up observations are needed to confirm any findings, says Speyerer. Some technological ingenuity will be required to allow the solar-powered rovers to operate in the shadowy depths of the craters. “A prospecting rover would be able to examine these features with the lower half of the rover in shadow, while the upper half and solar panel would remain illuminated,” says Speyerer.

Cahill’s group has also used LunarShader to identify which parts of the permanently shadowed regions would be most accessible to a rover. To explore the deepest craters, Cahill imagines rovers or landers with solar panels on a mast up to ten metres high, acting like a ‘solar snorkel’.

First published by Nature News [html] [pdf]