Issue no. 17, 2011 Published: May 13, 2011 |
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Sound test could identify 'locked-in' patients |
New isotope found for climatological dating |
'Vertical street' collects rainwater |
Translucent curtains soak up sound |
Flexible phone made from electronic paper created |
Computers sing to a better tune |
Telepresence robots go airborne |
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| Sound test could identify 'locked-in' patients |
While some people with serious brain damage are totally unaware of their
surroundings, others are in a 'minimally conscious' state (MCS). These
patients have some level of awareness but may be unable express it to
those around them because of the injuries to their brain. The discovery
of a signalling pathway in the brain that is different in the two
conditions could open the way to an easy and objective way of telling
whether a particular patient has any remaining consciousness.
At present, making these assessments is time-consuming and subjective,
and misdiagnoses are common. But now researchers from the University of
Liège in Belgium think they have discovered a new way of telling these
patients apart. They played irregular sounds to eight people previously
diagnosed as being in a vegetative state, 13 people in a minimally
conscious state and a healthy control group.
When the team compared how the three groups responded to the sounds,
they found that the brains of healthy and MCS patients generated a much
longer signal than patients in a vegetative state. The analysis pointed
to a specific feedback mechanism between the temporal cortex and the
frontal cortex. Both healthy and MCS subjects were able to send signals
between these brain areas in both directions. In vegetative state
patients, signals could pass from the auditory area to the frontal
cortex, but not in the opposite direction.
The team believe the loss of this so-called 'top-down' process is what
causes unconsciousness in brain-damaged patients, and that it can
therefore be used to identify MCS patients. If further research backs up
these findings, EEG could be used at the bedside of severely
brain-damaged patients to diagnose their state of consciousness. |
| New Scientist / Science
May 12, 2011 |
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| New isotope found for climatological dating |
Radioactive dating is used to determine everything from the age of
dinosaur fossils to Native American arrowheads. A new technique recently
developed at the US Department of Energy's Argonne National Laboratory
may give researchers another tool for radioactive dating that could be
of particular use in studying the history of climate change.
Argonne researchers created a special 'atom trap' to isolate and study
argon-39, an exceptionally rare isotope of a noble gas that occurs
naturally in small quantities in the atmosphere. Most atmospheric argon
is argon-40, which means it contains 18 protons and 22 neutrons.
However, occasionally an incoming high-energy proton from outer space
collides with the nucleus of an argon-40 atom to kick out one neutron
and create an unstable, radioactive isotope. This process happens so
infrequently that radioactive argon-39 is present in the atmosphere in
only extremely minute quantities.
The advantage of using argon-39 for radioactive dating lies in its
unique half-life, which is approximately 270 years. Scientists studying
the dynamics of groundwater or ocean currents on the timescale of 100 to
1,000 years might find argon-39 dating to be a particularly useful tool
in their analysis, according to the researchers.
To isolate argon-39 atoms from argon gas the team built a device called
an atom trap. The atom trap uses six laser beams to form a 'cage' that
catches only argon-39 while letting through all atoms of argon-40 or any
other isotopes present in the sample. Once trapped, an argon-39 atom
appears as a bright dot on a sensitive video camera. |
| R&D Magazine
May 12, 2011 |
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| 'Vertical street' collects rainwater |
The world's first 'vertical street' will soon be built in Melbourne,
Australia. Every sixth floor of the 35-storey building will have gardens
capable of growing trees up to 10 metres tall and the entire building
will be boasting the very latest in green technology.
While roof gardens and landscaped balconies have been constructed in the
past, architect Robert Caulfield says this is the first time that five
high-rise communal gardens have been attempted in the same building. To
achieve this feat, purpose-built planter boxes allowing tree roots to
grow in the confined 120-square-metre gardens, and structural supports
that hold the weight of the soil and trees will be used. Heat-reflective
glass and solar-powered lighting will also be incorporated.
Since the site is a mere 360 square metres, the building's external
walls - more than 8000 square metres - will be used to catch rainwater.
Triangular balconies and a jagged façade are used to reduce the sideways
movement of the wind, minimising the water escaping from the side. The
catchment will feed into the building's water supply to be used for
garden watering and toilet flushing.
The heating and cooling systems are also designed around the gardens. A
cooling system installed in each garden will pump water to six floors,
three above and three below. The short pipe minimises heating or cooling
loss. The building, which will house shops, offices and 154 apartments,
will be completed by 2014. |
| New Scientist
May 12, 2011 |
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| Translucent curtains soak up sound |
Researchers in Switzerland have developed a new kind of lightweight
curtain that can absorb sound waves while still letting light through.
They say it is ideal for soaking up noise in offices, conference rooms
or other places where natural light is needed.
The material for the curtains was designed using a computer model
developed by researchers at Empa, the Swiss Federal Laboratories for
Materials Science and Technology. The model was used to predict the
acoustic behaviour of a variety of curtains, with properties such as a
curtain's size, porosity and mass per unit area altered to maximize
sound absorption over a wide range of frequencies. Textile designer
Annette Douglas then used the model to build an actual material -
weaving together four or five different modified polyester yarns in such
a way as to maintain the absorption characteristics while also ensuring
fire resistance and light transmittance.
The material was then put to the test inside Empa's reverberation
chamber. With the curtain positioned 15 cm from a wall, the researchers
found it could absorb up to five times as much sound as typical
lightweight curtains. At low frequencies of about 200 Hz, it absorbed no
more than about a fifth of the incident sound energy. However, at
frequencies above 500 Hz (human ears having a maximum sensitivity
between about 3000-4000 Hz) the material absorbed around three-quarters
of the incident sound energy. |
| Physics World
May 10, 2011 |
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| Flexible phone made from electronic paper created |
A prototype flexible smartphone made of electronic paper has been
created by Canadian researchers. The PaperPhone can do all the things
bulkier smartphones can do such as make and take calls, send messages,
play music or display e-books. The gadget triggers different functions
and features when bent, folded and flexed at its corners or sides.
The device emerged from a collaboration between researchers at the Human
Media Lab at Queen's University, Canada and Arizona State University's
Motivational Environments Research group. The millimetres thick
prototype is built from the same e-ink technology found in Amazon's
Kindle e-book reader and this is bonded to flex sensors and a
touchscreen that interprets drawings and text written on it.
The prototype was created in order to investigate how easy it is for
people to use bending and flexing to control such a device. The early
version is connected to a laptop to interpret and record the ways test
subjects flexed it. |
| BBC News
May 06, 2011 |
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| Computers sing to a better tune |
In recent years, voice synthesis for converting text to spoken word has
improved considerably but combining that technology with auto-tuning
capability allows computers to 'sing'.
Software, such as Vocaloid, can successfully create lead vocals and
harmony parts from an input of lyrics and musical score. Careful
tweaking of the 'frequency curve' can make the vocals sound almost
natural by adding tremolo, vibrato and note overshoot. It is the
tweaking of the frequency curve that is critical to success but this
process is labour intensive and prone to human error.
Researchers at the University of Tokyo have turned to evolution to
devise a novel algorithm that compares the frequency curves from real
human performances and uses them to home in on a more realistic curve to
apply to the synthetic song. The team has simplified the optimisation
process for creating vocal frequency curves and have developed a
frequency model that can emulate human expression in a synthetic vocal.
Production of the first generation involves making eight individual
curves with random parameters and feeding them into Vocaloid. The second
step is for the music producer to listen to the effect of each curve on
their synthetic vocal and to move slider bars in the software interface
to reflect how well each curve works. In the third stage, the best
curves are used as the 'parents' to create a new generation of curves.
Finally, the second generation curves undergo crossover and random
mutation and the process repeated from step 2. Eventually, the fittest
frequency curves will emerge that endow the synthetic vocal with the
most realistic characteristics of human singing. |
| PhysOrg / International Journal of Knowledge Engineering and Soft Data Paradigms
May 06, 2011 |
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| Telepresence robots go airborne |
Picture the scene: your boss phones to say he is working from home. A
calm descends over the office. Workers lean back in their chairs. Feet
go up on desks. Suddenly, a super-sized video feed of your boss,
projected onto to the front of a helium-filled balloon equipped with a
loudspeaker, floats silently into the room and starts issuing orders
from above your head. Not such a good day.
This blimp-based boss, which brings to mind the all-seeing Big Brother
of George Orwell's 1984, is the creation of researchers at Sony Computer
Science Laboratories in Tokyo. The project is part of a wider movement
aimed at making 'telepresence' possible. Imagine a medical specialist
who can't make it to a regional hospital, but needs to consult with a
patient there. Or an academic expert who wants to deliver a lecture
remotely. Telepresence researchers are working on technology that can
get a representation of these people into the room. To put it another
way: telepresence lets you be in two places at the same time.
The project is still an early stage. The team have built a blimp and
shown that it can be operated remotely. Now they have to do user studies
- experiments that examine what it's like to interact with the device. |
| New Scientist
May 12, 2011 |
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