Topography of Gale Crater. Colour coding in this image of Gale Crater on Mars represents differences in elevation. The vertical difference from a low point inside the landing ellipse for NASA's Mars Science Laboratory (yellow dot) to a high point on the mountain inside the crater (red dot) is 5 km.
| Issue no. 41, 2011
Published: Nov 25, 2011
| New NASA rover to scout for life's habitats on Mars|
| Climate sensitivity to CO2 probed|
| Alzheimer's damage reversed by deep brain stimulation|
| Bionic contact lens 'to project emails before eyes'|
| Long-lasting all-weather night-vision material unveiled|
| 'Pre-social network' finds you friends in your hang-outs |
|New NASA rover to scout for life's habitats on Mars
|A nuclear-powered rover as big as a compact car is set to begin a
nine-month journey to Mars this weekend to learn if the planet is or
ever was suitable for life. The launch of NASA's Mars Science
Laboratory, nicknamed Curiosity, is set for 1502 GMT on Saturday from
Cape Canaveral Air Force Station.
The mission is the first since NASA's 1970s-era Viking program to
directly tackle the age-old question of whether there is life in the
universe beyond Earth. The consensus of scientists after experiments by
the twin Viking landers was that life did not exist on Mars. Two decades
later, NASA embarked on a new strategy to find signs of past water on
Mars, realising the question of life could not be examined without a
better understanding of the planet's environment.
Without a large enough moon to stabilise its tilt, Mars has undergone
dramatic climate changes over the eons as its spin axis wobbled closer
or farther from the sun. The history of what happened on Mars during
those times is chemically locked in its rocks, including whether liquid
water and other ingredients believed necessary for life existed on the
planet's surface, and if so, for how long.
In 2004, the rovers Spirit and Opportunity landed on opposite sides of
Mars' equator to tackle the question of water. Both rovers found signs
that water mingled with rocks during Mars' past. The new rover Curiosity
shifts the hunt to other elements key to life, particularly organics.
The spacecraft, which is designed to last two years, is outfitted with
10 tools to analyse the Gale Crater on Mars. The site is a 154km wide
basin that has a layered mountain of deposits stretching 5km above its
floor. Scientists do not know how the mound formed but suspect it is the
eroded remains of sediment that once completely filled the crater.
Nov 24, 2011
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|Climate sensitivity to CO2 probed
|Global temperatures could be less sensitive to changing atmospheric
carbon dioxide (CO2) levels than previously thought, a study led by
Oregon State University, US, suggests.
Previous climate models have used meteorological measurements from the
last 150 years to estimate the climate's sensitivity to rising CO2. From
these models, scientists find it difficult to narrow their projections
down to a single figure with any certainty, and instead project a range
of temperatures that they expect, given a doubling of atmospheric CO2
from pre-industrial levels. The new analysis, which incorporates
palaeoclimate data into existing models, attempts to project future
temperatures with a little more certainty.
By looking at surface temperatures during the last Ice Age - 21,000
years ago - when humans were having no impact on global temperatures,
the team showed that this period was not as cold as previous estimates
suggest. By incorporating this newly discovered 'climate insensitivity'
into their models, the international team was able to reduce their
uncertainty in future climate projections.
The new models predict that given a doubling in CO2 levels from
pre-industrial levels, the Earth's surface temperatures will rise by 1.7
to 2.6 degrees C. That is a much tighter range than suggested by the
Intergovernmental Panel on Climate Change (IPCC)'s 2007 report, which
suggested a rise of between 2 to 4.5 degrees C. The expected average
surface temperatures is reduced to just over 2 degrees C, from 3.
The results do not mean threat from human-induced climate change should
be treated any less seriously. But to induce large-scale warming of the
planet, leading to widespread catastrophic consequences, we would have
to increase CO2 more than we are going to do in the near future,
according to the researchers.
| BBC News / Science
Nov 25, 2011
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|Alzheimer's damage reversed by deep brain stimulation
|Brain shrinkage in people with Alzheimer's disease can be reversed in
some cases - by jolting the degenerating tissue with electrical
impulses, reducing the cognitive decline associated with the disease.
In Alzheimer's disease it is known that the brain shrinks, particularly
the hippocampus. What's more, brain scans show that the temporal lobe,
which contains the hippocampus, and another region called the posterior
cingulate use less glucose than normal, suggesting they have shut down.
Both regions play an important role in memory. To try to reverse these
degenerative effects, researchers at Toronto Western Hospital in
Ontario, Canada turned to deep brain stimulation - sending electrical
impulses to the brain via implanted electrodes.
The group inserted electrodes into the brains of six people who had been
diagnosed with Alzheimer's at least a year earlier. They placed the
electrodes next to the fornix - a bundle of neurons that carries signals
to and from the hippocampus - and left them there, delivering tiny
pulses of electricity 130 times per second. Follow-up tests a year later
showed that the reduced use of glucose by the temporal lobe and
posterior cingulate had been reversed in all six people.
While they saw hippocampal shrinking in four of the volunteers, the
region grew in the remaining two participants. Tests showed that these
two individuals appeared to have better than expected cognitive
function, although the other four volunteers did not. Though the team
are not sure exactly how the treatment works, their recent work in mice
suggests that the electrical stimulation might drive the birth of new
neurons in the brain. Deep brain stimulation in mice also triggers the
production of proteins that encourage neurons to form new connections.
| New Scientist / Annals of Neurology
Nov 23, 2011
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|Bionic contact lens 'to project emails before eyes'
|A new generation of contact lenses that project images in front of the
eyes is a step closer after successful animal trials, say scientists.
The technology could allow wearers to read floating texts and emails or
augment their sight with computer-generated images, Terminator-style.
Early tests show the device is safe and feasible, says the University of
Washington in Seattle. But there are still wrinkles to iron out, like
finding a good power source. Currently, their crude prototype device can
only work if it is within centimetres of the wireless battery. And its
microcircuitry is only enough for one light-emitting diode.
The researchers envisage hundreds more pixels could be embedded in the
flexible lens to produce complex holographic images. For example,
drivers could wear them to see journey directions or their vehicle's
speed projected onto the windscreen. Similarly, the lenses could take
the virtual world of video gaming to a new level. They could also
provide up-to-date medical information like blood sugar levels by
linking to biosensors in the wearer's body.
Building the end product was a challenge because materials used to make
conventional contact lenses are delicate. Manufacturing electrical
circuits, however, involves inorganic materials, scorching temperatures
and toxic chemicals. Researchers built the circuits from layers of metal
only a few nanometres thick and constructed ultra-thin LEDs.
| BBC News / Journal of Micromechanics and Microengineering
Nov 22, 2011
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|Long-lasting all-weather night-vision material unveiled
|Scientists at University of Georgia claim to have invented a material
that releases over two weeks of night-vision light after just one
minute's exposure to the sun. The team says the near-infrared emitting
substance could offer the military 'secret' illumination at nighttime.
The all-weather material could also revolutionise diagnostic medicine.
The material combines the well-known near infrared-light emitter
trivalent chromium ion with zinc gallogermanates - a complex oxide
compound. The chromium ions normally release all of their near
infrared-light in the space of a few milliseconds after being exposed to
'excitation light', such as sunlight. However, the zinc and
gallogermanates create a 'labyrinth of traps' for the energy causing it
to be released over an extended period of up to 360-hours.
The scientists tested this material in a variety of conditions and found
it could be rapidly and repeatedly charged even if the day was cloudy,
overcast or rainy. The team said the phosphorescent substance did not
need to be exposed to direct sunlight. It took on a charge in shadows,
underwater or even submerged in a corrosive bleach solution. Fluorescent
lights also activated the process.
| BBC News / Nature Materials
Nov 21, 2011
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|'Pre-social network' finds you friends in your hang-outs
|Imagine a 'pre-social' network - a bit like the 'pre-crime' unit that
figured in Minority Report. Such a network would predict where users
will go, how long they will stay and who they are likely to meet there.
It may sound Orwellian, but researchers believe it could spawn a novel
form of social network - one which tells its users where and when people
with similar interests or habits are likely to congregate.
The system, named Jyotish after the Sanskrit term for Hindu astrology,
was developed at Boeing's research centre at the University of Illinois
in Urbana-Champaign. Boeing needs it to predict the movements of work
crews in its huge aircraft factories, but the system's developers reckon
it can do a lot more.
Jyotish draws up maps of people's movements by monitoring the
connections their smartphones make to Wi-Fi and Bluetooth networks,
which have ranges of 100 and 10 metres respectively - small enough to
pin down users' locations and thus who they meet. The team tested this
by giving 79 volunteers Android smartphones whose Wi-Fi and Bluetooth
modems were made trackable. This detailed log of users' movements and
habits can be used to create a mobile version of Facebook that allows
people in the same area to create a 'hang-out event'.
'Indeed, this version of Facebook could even recommend that people
create a hang-out event because they are likely to be in the same
location in the future,' according to one of the developers.
| New Scientist / Pervasive and Mobile Computing
Nov 24, 2011
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