Science & Technology


"Resurrection plants" might lead to drought-tolerant crops

Jill Farrant, a professor of molecular and cell biology at the University of Cape Town, hopes that unlocking the genetic codes of drought-tolerant plants could help farmers toiling in increasingly hot and dry conditions
As the race to adapt to climate change quickens, a South African scientist is leading global research into developing crops that mimic the extraordinary survival skills of "resurrection plants".

Jill Farrant, a professor of molecular and cell biology at the University of Cape Town, hopes that unlocking the genetic codes of drought-tolerant plants could help farmers toiling in increasingly hot and dry conditions.

With more than 130 known varieties in the world, resurrection plants are a unique group of flora that can survive extreme water shortages for years.

During a drought, the plant acts like a seed, becoming so dry it appears dead.

But when the skies finally open and the rain pours down, the shrivelled plant bursts "back to life", turning green and robust in just a few hours.

Solar Flares

VW and the Paris climate summit: Crass crony corporate capitalistic capitulation

© Unknown
Winston Churchill famously defined an appeaser as someone who feeds a crocodile, hoping it will eat him last. In the debate about global warming, business, especially large corporations, is the largest sector of appeasers and some, like Volkswagen, are now, rightfully, paying the price.

Churchill was talking about Neville Chamberlain's appeasement with Adolf Hitler. In a classic example of the claim that fact is stranger than fiction, it was Adolf Hitler who sketched the design for the first Volkswagen (Figure1).


Study shows Europeans developed ability to tolerate milk thousands of years later

© Getty Images
Without a key mutation, the enzyme that enables us to digest lactose becomes deactivated after weaning.
The ability for adult Europeans to drink milk was inherited from Russian herders just 4,000 years ago, a genetic study has shown.

The findings come from the largest ancient DNA study of its kind published in the journal Nature.

"Everyone assumed it came to Europe with the first farmers," co-author Dr Bastien Llamas, from the Australian Centre for Ancient DNA at the University of Adelaide, said.

"But you actually had a 4,500-year period when European farmers could not actually drink milk."

The study of DNA from 230 Eurasians who lived between 6500 BC and 300 BC showed that Russian herders from the Great Steppes brought the enzymes for lactose tolerance into Europe.

"Suddenly 4,000 years ago there's a revolution when the Steppe herders brought the enzymes they needed," Dr Llamas said.

Earlier this year, Dr Llamas and colleagues found Europeans descended from three groups: Stone-Age hunter-gatherers, farmers that migrated from Anatolia (modern-day Turkey), and nomadic herders that migrated west from the Great Steppe in Russia.

For this study, the researchers analysed patterns in the genomes of these groups to look at how human traits had changed since the advent of agriculture in Europe around 8,500 years ago.

One of the most surprising findings related to the emergence of the genetic mutation that enables humans to drink raw milk.

This mutation enables the enzyme lactase, which digests lactose in milk, to remain active long after weaning occurs.

Most people had assumed the mutation, which is widespread in Europe today, would have been introduced by the Anatolian farmers, who had been keeping animals such as cows since around 6500 BC.

However, Dr Llamas and colleagues found the mutation did not enter the European population until 4,000 years later, when the Russian herders arrived.


NASA's tensegrity robot planned for planetary exploration

Image: NASA
Despite all the predictions from futurologists over the years on how robots would look and work, NASA's newest bot aimed at exploring distant worlds proves them all wrong. It's not a humanoid or a mechanical animal from science fiction, but resembles a geometric structure and was actually inspired by a baby toy.

NASA has unveiled the Super Ball robot, the space agency's newest tool for space exploration specifically designed for landing safely on distant planets with unstudied terrains and landscapes, always a challenge for spacecraft and exploration vehicles.

The creation, designed by engineers from NASA's Innovative Advanced Concepts Program, resembles a baby toy made of wire and rods that is indestructible, and as such scientists believe it can handle strong impacts like those caused by landing on a planet's surface. The idea came to NASA's developers when they first saw the toy falling — it was absorbing impact of landing on the ground surprisingly well — and they decided that this physical principle, known as tensegrity, is perfect for space robotics.

Comment: see a tensegrity demonstration [link]

  • Super Ball Bot for Planetary Exploration [link]
  • Report: Planetary Landing and Exploration [link]


Mars to get planetary ring when Phobos breaks apart

© NASA/JPL/University of Arizona
Phobos, the larger of Mars' two moons.
Mars is destined to get a spectacular new planetary ring system to rival that of Saturn, but don't hold your breath because it will not be for another 30 million years or so, according to scientists.

The findings, published in the journal Nature Geoscience, are based on a new study to determine the fate destined to befall the diminutive Martian moon Phobos.

"We found that Phobos is too weak to withstand tidal stresses from Mars and we expect it to break apart in a few tens of millions of years and form a ring around Mars," the study's lead author Dr Benjamin Black of the University of California said.

Only the giant planets of the outer solar system have rings at the moment.

Phobos — the larger of the two moons circling Mars — orbits just 6,000 kilometres above the surface of the red planet, closer than any other moon in the solar system.

"Over time Phobos is creeping inwards towards Mars at a couple of centimetres per year," Dr Black said.

"We wanted to figure out whether Phobos crashes into Mars or breaks apart to form a ring, so we needed to know how strong it was — is it going to be able to stand the increasing tidal stresses that are going to be pulling this little moon apart, or will it eventually succumb to these forces?"

Dr Black and co-author Tushar Mittal found that Phobos will be pulled apart by the red planet's gravitational tidal forces in about 20 to 40 million years' time.

"We concluded that Phobos would break apart between 2.4 and about 1.1 Mars radii, somewhere between 8,500 kilometres down to around 4,000 kilometres or so," Dr Black said.


A question of scale? From nanocrystals to earthquakes, solid materials share similar failure characteristics, study finds

© University of Illinois
When solid materials such as nanocrystals, bulk metallic glasses, rocks, or granular materials are slowly deformed by compression or shear, they slip intermittently with slip-avalanches similar to earthquakes.
Apparently, size doesn't always matter. An extensive study by an interdisciplinary research group suggests that the deformation properties of nanocrystals are not much different from those of the Earth's crust.

"When solid materials such as nanocrystals, bulk metallic glasses, rocks, or granular materials are slowly deformed by compression or shear, they slip intermittently with slip-avalanches similar to earthquakes," explained Karin Dahmen, a professor of physics at the University of Illinois at Urbana-Champaign. "Typically these systems are studied separately. But we found that the scaling behavior of their slip statistics agree across a surprisingly wide range of different length scales and material structures."

"Identifying agreement in aspects of the slip statistics is important, because it enables us to transfer results from one scale to another, from one material to another, from one stress to another, or from one strain rate to another," stated Shivesh Pathak, a physics undergraduate at Illinois, and a co-author of the paper, "Universal Quake Statistics: From Compressed Nanocrystals to Earthquakes," appearing in Scientific Reports. "The study shows how to identify and explain commonalities in the deformation mechanisms of different materials on different scales.

"The results provide new tools and methods to use the slip statistics to predict future materials deformation," added Michael LeBlanc, a physics graduate student and co-author of the paper. "They also clarify which system parameters significantly affect the deformation behavior on long length scales. We expect the results to be useful for applications in materials testing, failure prediction, and hazard prevention."


Bird brain? Pigeons make good pathologists, study finds

© Richard Levenson / University of California Davis
Researchers at the University of California Davis and University of Iowa have trained pigeons to analyze tumor tissue.
Pigeons can tell the difference between healthy tissue and a tumor, and they might be able to sit in for humans doing some of the more boring chores in a pathology lab, researchers said Wednesday.

They're especially eagle-eyed when it comes to diagnosing breast cancer, it seems, the researchers report in the Public Library of Science journal PLoS ONE.

They flunk out on reading mammograms, however, so don't look for the birds to be replacing human specialists any time soon, the teams at the University of Iowa and the University of California Davis said.


"Rat vision" may give humans best sight of all

© kovtuan / Fotolia
Rodents are somewhat preoccupied with detecting and avoiding predators, and their visual systems reflect this: their eyes are on each side of their head, scanning different fields of view, and stereo vision is poor.
Humans have the best of all possible visual worlds because our full stereo vision combines with primitive visual pathways to quickly spot danger, a study led by the University of Sydney has discovered.

The surprising finding published today in Current Biology shows that in humans and other primates, information from the eyes is not only sent to the visual cortex for the complex processing that allows stereoscopic vision, but also could feed directly into deep brain circuits for attention and emotion.

"The brain cells that we identified suggest that human and other primates retain a visual pathway that traces back to the primitive systems of vertebrates like fish and frogs," said University of Sydney's Professor Paul Martin from the Sydney Medical School, who led the team that made the discovery.


Marine animals use new form of secret light communication

© Yakir Gagnon/QBI
This image shows a mantis shrimp in a defensive position, on its back with its legs, head and heavily armored tail closed over. The red color indicates areas of reflected circular polarizing light.
Researchers from the Queensland Brain Institute at The University of Queensland have uncovered a new form of secret light communication used by marine animals.

The findings may have applications in satellite remote sensing, biomedical imaging, cancer detection, and computer data storage.

Dr Yakir Gagnon, Professor Justin Marshall and colleagues previously showed that mantis shrimp (Gonodactylaceus falcatus) can reflect and detect circular polarising light, an ability extremely rare in nature. Until now, no-one has known what they use it for.

The new study shows the shrimp use circular polarisation as a means to covertly advertise their presence to aggressive competitors.


Ghostly and beautiful: "Planetary nebulae" get more meaningful physical presence

© ESA/Hubble & NASA, ESO, Ivan Bojicic, David Frew, Quentin Parker
A collage showing 22 individual planetary nebulae artistically arranged in approximate order of physical size. The scale bar represents 4 light years. Each nebula's size is calculated from the authors' new distance scale, which is applicable to all nebulae across all shapes, sizes and brightnesses. The very largest planetary nebula currently known is nearly 20 light years in diameter, and would cover the entire image at this scale.
A way of estimating more accurate distances to the thousands of so-called planetary nebulae dispersed across our Galaxy has been announced by a team of three astronomers based at the University of Hong Kong: Dr David Frew, Prof Quentin Parker and Dr Ivan Bojicic. The scientists publish their results in Monthly Notices of the Royal Astronomical Society.

Despite their name, planetary nebulae have nothing to do with planets. They were described as such by early astronomers whose telescopes showed them as glowing disc-like objects.

We now know that planetary nebulae are actually the final stage of activity of stars like our Sun. When they reach the end of their lives, these stars eject most of their atmosphere into space, leaving behind a hot dense core. Light from this core causes the expanding cloud of gas to glow in different colours as it slowly grows, fading away over tens of thousands of years.

There are thousands of planetary nebulae in our Galaxy alone, and they provide targets for professional and amateur astronomers alike, with the latter often taking spectacular images of these beautiful objects. But despite intense study, scientists have struggled to measure one of their key properties -- their distance.