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Image of GFAJ-1 grown on arsenic.
(NASA)
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Issue no. 39, 2010
Published: Dec 03, 2010 |
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 NASA discovers life built with toxic chemical | | Lighting up chips gives computers a brain boost | | Africa 'can feed itself in a generation' | | Tongue clicks to control wheelchairs | | nanotube breakthrough heralds next-gen microchips | | Fly eyes inspire ultimate camera |
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| NASA discovers life built with toxic chemical |
NASA-funded astrobiology research has changed the fundamental knowledge
about what comprises all known life on Earth. Researchers conducting
tests in the harsh environment of Mono Lake in California have
discovered the first known microorganism on Earth able to thrive and
reproduce using the toxic chemical arsenic. The microorganism
substitutes arsenic for phosphorus in its cell components. This finding
of an alternative biochemistry makeup will alter biology textbooks and
expand the scope of the search for life beyond Earth.
Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur are the six
basic building blocks of all known forms of life on Earth. Phosphorus is
part of the chemical backbone of DNA and RNA, the structures that carry
genetic instructions for life, and is considered an essential element
for all living cells. Phosphorus is a central component of the
energy-carrying molecule in all cells (adenosine triphosphate) and also
the phospholipids that form all cell membranes. Arsenic, which is
chemically similar to phosphorus, is poisonous for most life on Earth.
Arsenic disrupts metabolic pathways because chemically it behaves
similarly to phosphate.
The microbe, strain GFAJ-1, is a member of a common group of bacteria,
the Gammaproteobacteria. In the laboratory, the researchers successfully
grew microbes from the lake on a diet that was very lean on phosphorus,
but included generous helpings of arsenic. When researchers removed the
phosphorus and replaced it with arsenic the microbes continued to grow.
Subsequent analyses indicated that the arsenic was being used to produce
the building blocks of new GFAJ-1 cells. |
| NASA / Science Express
Dec 02, 2010 |
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| Lighting up chips gives computers a brain boost |
The computer giant IBM has unveiled a new type of computer chip that
integrates both electrical and optical nano-devices on the same piece of
silicon. This could soon make it possible for supercomputers to perform
one million trillion calculations - or an exaflop - in a single second.
Such supercomputers would not only be a thousand times faster than
today's most powerful petaflop machines, but for the first time would
have the same processing power as the human brain.
One of the main challenges in making super-fast computers lies in the
ability to quickly transmit large amounts of data between chips. But
while optical fibres are much better at doing this than copper wires,
components that convert electrical data into photons tend to only exist
in separate off-chip devices. This means that data still has to flow
through wires to reach them, which creates a bottleneck.
But over the last four years IBM has developed a range of tiny photonic
switches, waveguides, detectors and modulators, all of which are made
out of silicon. And now for the first time these have been integrated
into chips, so that the same silicon that makes up the electrical
circuitry and transistors of the chip is also used to convey and convert
photons, and channel them off the chip through thousands of waveguides,
each just 500 nanometres wide. |
| New Scientist
Dec 01, 2010 |
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| Africa 'can feed itself in a generation' |
A new book claims Africa could feed itself within a generation, and
become a major agricultural exporter. The book, The New Harvest, by
Harvard University professor Calestous Juma, calls on African leaders to
make agricultural expansion central to all decision-making.
Global food production has rocketed in recent decades but has stagnated
in many parts of Africa, despite the continent having 'abundant' arable
land and labour, says Juma. He estimates that while food production has
grown globally by 145% over the past 40 years, African food production
has fallen by 10% since 1960, which he attributes to low investment.
While 70% of Africans may be engaged in farming, those who are
undernourished on the continent has risen by 100 million to 250 million
since 1990, he estimates.
Juma's blueprint calls for the expansion of basic infrastructure,
including new road, irrigation and energy schemes. Farms should be
mechanised, storage and processing facilities built, while biotechnology
and GM crops should be used where they can bring benefits. But what was
needed above all else was the political will at the highest level.
He believes there is great scope to expand crops traditionally grown in
Africa, such as millet, sorghum, cassava or yams. He sees areas where
farmers will need to adapt to tackle a changing climate - cereal farmers
may switch into livestock, he says, while others may chose more radical
options. He also envisages genetic modification playing a growing role
in African agriculture, with GM cotton and GM maize, which are already
being grown on the continent, just the start of things to come. |
| BBC News
Dec 02, 2010 |
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| Tongue clicks to control wheelchairs |
Tongue clicking could soon help paralysed people steer their
wheelchairs. The key is an in-ear device that listens out for clicks and
tuts and translates the sounds into commands for a wheelchair.
Mouth interfaces that interact with wheelchairs are already quite common
for severely disabled people. One retainer-like device that fits within
the roof of the mouth houses buttons that can be pressed with the
tongue. Besides issues of hygiene, these devices make it difficult for
the user to eat or speak, if they are able to, while using it.
Monitoring tongue movements through the ear avoids these problems.
The new device, a simple microphone that resembles an earbud for
listening to music, picks up low-frequency sounds made by four sorts of
tongue click, chosen because each has a distinct local acoustic
signature that the system won't easily confuse with other sounds. The
microphone sends the information to a signal processor which categorises
the clicks and passes the information to the wheelchair, where each
click type moves the chair in a distinct direction.
The developers of the device from the University of Bristol, UK, have so
far used the interface to navigate a virtual wheelchair through a maze.
They have also used it to control the reaching and grasping movements of
a robotic arm. The four tongue clicks can be mastered in a couple of
hours, say the researchers., who are looking at whether the number of
commands can be increased by using a microphone in each ear, to get
clearer signal. |
| New Scientist
Dec 01, 2010 |
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| nanotube breakthrough heralds next-gen microchips |
Researchers from Cambridge University have developed a technique for
crafting integrated circuits which transmit current through carbon
nanotubes, potentially reducing the size and improving the density of
microchips. Using carbon nanotubes to transmit current allowed the
researchers to eliminate the need for conventional copper wiring.
Chipmakers could increase electrical current densities by as much as
five times, the researchers said, allowing for smaller and more powerful
microprocessors. The researchers devised a method which arranges carbon
atoms at a far greater density, allowing the nanotubes to conduct
sufficient electricity for an integrated circuit. The researchers plan
to release further details on the processor later this month at an IEEE
conference in San Francisco.
Nanotechnology has long been viewed as key to the development of smaller
and more powerful computing devices. Researchers believe that nanotech
circuitry will allow chipmakers to go beyond the physical limits of
conventional silicon fabrication methods. Nanotubes have also been
considered for use in storage, networking and display hardware. |
| VNUnet UK
Dec 02, 2010 |
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| Fly eyes inspire ultimate camera |
Before you swat that annoying fly, consider this: Its eyes inspired the
invention of a camera with a 360-degree view on the world and the
ability to reproduce images in 3-D. The applications are seemingly
limitless, ranging from enhanced robot navigation and surveillance to
3-D movies and immersive realities for video gamers, according to its
inventors at Ecole Polytechnique Federale de Lausanne in Switzerland.
The researchers say the technology overcomes two main problems of
traditional cameras: the fact that they observe only a fraction of the
scene in a specific direction and the camera's traditional lack of
depth. Taking a cue from the common housefly's eyes, which are composed
of thousands of spherical photoreceptors, the researchers packed more
than 100 cameras similar to those used in mobile phones onto an
orange-sized metallic sphere. The result is a camera that sees
information located all around it. At the same time, special algorithms
calculate the distance to the objects it sees, enabling the creation of
an accurate 3D reconstruction.
This contrasts with traditional 3-D images, which generally start with
2-D images made with two lenses that are then overlaid to generate a 3-D
effect when seen with special glasses. Newer technology is making 3-D
imagery possible with single-lens, point-and-shoot cameras such as the
Sony WX5 and TX9. But the 360-degree camera that sees in 3-D is likely
to change the entire field of image acquisition, with a huge range of
potential applications, according to the researchers. |
| MSNBC
Dec 01, 2010 |
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