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Issue no. 37, 2008
Published: Nov 21, 2008 |
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 NASA tests 'deep space Internet' | | How a camera can 'steal' your keys | | Light opens up a world of sound for the deaf | | Invention: Diamond dialysis implant | | Belgian levitation technique floats water with noise | | US firm unveils plans for mini nuclear reactors | | France dominates Europe's digital library | | Rational or random? Model shows how people send emails |
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| NASA tests 'deep space Internet' |
The US space agency NASA has successfully conducted a first test of a
deep space communications network modelled on the internet. Jet
Propulsion Laboratory engineers used software called Disruption-Tolerant
Networking, or DTN, to transmit dozens of space images to and from a
NASA spacecraft some 32.4m kilometres from Earth.
NASA said the software protocol, which must be able to withstand delays,
disruptions and disconnections in space, was designed in partnership
with Vint Cerf, vice president at Google. DTN sends information using a
method that differs from the normal TCP/IP communication suite, which
Cerf co-designed. Unlike TCP/IP, DTN does not assume a continuous
end-to-end connection, NASA said, noting that glitches can happen when a
spacecraft moves behind a planet, or when solar storms and long
communication delays occur.
NASA said that if a destination path cannot be found, data packets are
not discarded but kept by each network node until it can communicate
safely with another node. Eventually the information is delivered to the
end user. A test of DTN software loaded on board the International Space
Station will begin next summer. NASA said that an 'Interplanetary
Internet' could enable many new types of space missions including
complex flights involving multiple spacecraft and ensure reliable
communications for astronauts on the moon. |
| Google news / AFP / EJC
Nov 19, 2008 |
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| How a camera can 'steal' your keys |
Scientists at the University of California have developed a software
algorithm that automatically creates a physical key based solely on a
picture of one, regardless of angle or distance. The project, called
Sneakey, was meant to warn people about the dangers of haphazardly
placing keys in the open or posting images of them online.
To demonstrate their work the researchers set up a camera with a zoom
lens 60 metres away. Using those photos, they created a working key 80%
on their first try. Within three attempts they opened every lock. Three
attempts could take less than five minutes. The replication process is
very easy. Once the researchers have the image it takes the software
roughly 30 seconds to decode the ridges and grooves on the key. If the
angle is off or the lighting is tricky it takes the computer take a
little longer. The longest part of the process, about one whole minute,
is cutting the key.
Keys, as the researchers demonstrated, are actually fairly easy to
decode. A majority of keys marketed to consumers are basically just four
to six different numbers. Each number corresponds to a ridge or valley
in the key. When inserted into a lock, the ridges and valleys lines up a
series of small pins that lets the lock turn. |
| MSNBC / Discovery.com
Nov 19, 2008 |
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| Light opens up a world of sound for the deaf |
Infrared light can stimulate neurons in the inner ear as precisely as
sound waves, a discovery that could lead to better cochlear implants for
deaf people.
A healthy inner ear uses hair cells that respond to sound to stimulate
neurons that send signals to the brain. But hair cells can be destroyed
by disease or injury, or can contain defects at birth, leading to
deafness. Cochlear implants can directly stimulate neurons and the
hearing provided by today's implants is good enough to enable deaf
children to develop speech skills. However, implant users still find it
tough to appreciate music, communicate in a noisy environment and
understand tonal languages like Mandarin. That is because the implants
use only 20 or so electrodes, a small number compared to the 3000-odd
hair cells in a healthy ear.
Researchers at Northwestern University in Chicago shone infrared light
directly onto the neurons in the inner ear of deaf guinea pigs. At the
same time, the researchers recorded electrical activity in the inferior
colliculus, producing a set of frequency 'maps'. These maps are a good
indication of the quality of sound information sent to the brain.
Electrical stimulation of the inner ear by a cochlear implant produces
blurred maps, but the light stimulation produced maps that were as sharp
as those produced by sound in hearing guinea pigs, according to the
researchers. |
| New Scientist
Nov 20, 2008 |
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| Invention: Diamond dialysis implant |
Kidney failure currently affects around 400,000 people in the US and
countless others around the world. And even for people who can access
it, plugging into a dialysis machine is a far from an ideal solution. As
well as forcing people to structure their lives around the process,
dialysis is not as efficient as a real kidney at removing toxic
chemicals from the blood, while leaving important biomolecules
untouched. A new kind of filter could avoid those problems, though, and
be small enough to implant inside the body.
Existing dialysis filters have particular problems screening out
medium-sized proteins such as ?2-microglobulin, which is produced by the
immune system and toxic if it builds up. The problem is that larger
proteins block the filters designed to deal with those mid-size
compounds. Now William Fissell at the Cleveland Clinic in Ohio and
colleagues at the University of Michigan have developed a filter made
from a series of diamond layers drilled with successively smaller
microscopic holes.
Each layer only allows molecules below a certain size to pass through.
And an electric field keeps away larger proteins that would otherwise
clog its pores. This makes the filter more effective at removing toxic
molecules from the blood stream than conventional membranes. Moreover,
the diamond device is small enough to be implanted into the body and
works at ordinary blood pressures. |
| New Scientist
Nov 19, 2008 |
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| Belgian levitation technique floats water with noise |
Some musical shake, rattle and roll has led physicists at the University
of Ličge, Belgium, to develop a new kind of levitation. It only works
for tiny drops of liquid, but could provide a new way to handle
biological or forensic samples without contaminating them.
The researchers set out to recreate the way water droplets spilt on
speakers danced to the bass vibrations. They substituted a vibrating
bath of oil for the speakers and released 1-millimetre-wide droplets of
a less viscous oil on top. When the oil in the bath vibrates with the
right frequency - about 110 hertz - the droplets bounce and roll freely
on an air cushion above it. This happens because a droplet has to push
the air beneath it out of the way in order to fall. But when the bath is
vibrating at the right frequency, it creates a resonating layer of air
over its surface that is not pushed aside so easily. The droplets bob
around without touching the surface of the bath, at a height of between
150 nanometres and 1.5 centimetres.
Dealing with tiny samples usually involves the use of microfluidic chips
with minuscule engraved channels. But cleaning them is difficult and it
is not always easy to keep liquids separate until they are ready to be
mixed. The bouncing droplets offer a way around these problems. |
| New Scientist / Journal reference: New Journal of Physics
Nov 19, 2008 |
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| US firm unveils plans for mini nuclear reactors |
Nuclear power is normally associated with gigawatt-scale facilities
costing billions of dollars and run by armies of scientists and
engineers. But some have long argued that much smaller, unmanned
reactors could play a role too. Such reactors, which would have power
outputs of only a few tens of megawatts, would be particularly suitable
for people or companies in remote parts of the world.
Now, US company Hyperion Power Generation has brought the reality of
tiny nuclear reactors one step closer with its Power Module. This
nuclear reactor is not much larger than a hot-tub and could supply
thermal energy at a rate of about 70 MW. That could be converted into
about 27 MW of electricity, which would be enough to supply about 20,000
households. Unlike conventional nuclear power plants, Hyperion's reactor
uses uranium hydride, which is essentially enriched uranium metal that
has absorbed a large amount of hydrogen. As the uranium nuclei decay by
fission, they release neutrons that are slowed down by the hydrogen,
which acts as the moderator. The slow neutrons can then split further
uranium nuclei and trigger a chain reaction.
The novel feature of the reactor is that the power output is kept steady
without the need for any moving parts, flowing water, or human
intervention. If the uranium hydride gets too hot, the hydrogen is
driven out of the uranium metal and the chain reaction stops. But as the
system is sealed, the hydrogen flows back into the uranium when it has
cooled, allowing the reaction to restart. |
| PhysicsWorld
Nov 20, 2008 |
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| France dominates Europe's digital library |
France has never been shy about promoting its culture, so few were
surprised when it took a close interest in a new digital library
intended to showcase Europe's history, literature, arts and science.
But when the new site, called Europeana, began life on Thursday, more
than half of its two million items were from just one of the 27
countries in the European Union: France. So comprehensive is France's
cultural dominance over this cyberspace outpost that other countries are
having their own history written for them - in French, of course.
Europeana (http://www.europeana.eu) combines the digital resources of
museums and libraries, and the information provided includes paintings,
maps, videos and newspapers. Material is free of copyright so it can be
downloaded for blogs, research or schoolwork by anyone. Already, the
images online include the Magna Carta from Britain, the Vermeer painting
'Girl With a Pearl Earring' from the Mauritshuis Museum in The Hague and
a copy of Dante's 'Divine Comedy'. But only 1% of the content has
information about Germany, 1.4% about Spain and only 10% about Britain.
The European Commission says that if it achieves its aim of putting 10
million items onto the digital library by 2010, it will come at a price
of 350 million to 400 million euros. |
| New York Times
Nov 19, 2008 |
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| Rational or random? Model shows how people send emails |
How do people respond to e-mails? Do they act rationally, responding to
the most important first, making sure the process is efficient? Or do
they send e-mails randomly, when they are at their computers or when
they have time, without any regard to efficiency? These are questions a
team led by Luís Amaral at Northwestern University set out to answer.
After studying e-mails sent and received from more than 3,000 e-mail
accounts at a European university during a three-month period, they
created a model that shows people send e-mail randomly, but in cycles.
Amaral was inspired to create such an e-mail model after a recent paper
said that the rational model - where people respond to e-mails in the
most efficient way - was the correct model. 'I was not convinced, since
I don't do it in a rational way,' he said. But if a random model was
correct, there would be a typical interval between e-mails - which
appeared not to be the case. He wondered if it was possible for people
to send e-mail randomly but still have non-random intervals where they
did not send e-mail. The answer, it turned out, was fairly simple:
People don't send e-mails when they are sleeping.
The result was a model in which people send e-mails at random, but the
probability of them sending e-mails during a given period depended on
what that period was. If it was in the middle of the night, the
probability was near zero. If it was during the weekend, the probability
was much lower than during weekdays. The researchers say that their
model explains all the data, and that it shows that people have cycles
in which they use certain services. Predictions can be based on those
cycles to know when people are going to request a service. Even though
it is random, there are peaks in demand that do not look random. |
| PhysOrg / Proceedings of the National Academy of Sciences
Nov 19, 2008 |
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