16 | New Scientist | 27 July 2019Climate changeSecrets of how vital
drugs harm hearingSOME life-saving antibiotics that
kill a broad range of bacteria can
also cause hearing loss, and we
may now know why.
Known as aminoglycosides,
these drugs are useful for treating
infections in newborns, which
can prove fatal within one or two
days, too soon for tests to reveal
the microbe responsible.
To better understand why this
class of antibiotics is linked withSmart skin for
sensitive robotsAN ARTIFICIAL skin that senses
temperature and pressure can
send signals 1000 times faster
than the human nervous system.
Benjamin Tee at the National
University of Singapore and his
colleagues created the rubber
and plastic skin, which has tiny
sensors that can detect pressure,
bending and temperature.
When the skin presses against
something, the sensors transmit
electrical pulses back to one
receiver. Each sensor has a unique
pulse to make it identifiable,
meaning multiple signals can
be combined through the one
receiver, speeding up delivery.
Unlike in most electronic
systems, all of the sensors are
connected together using one
wire, meaning that measurements
from across the skin arrive at the
same time. Human skin sensors
send signals at a maximumBionics^ AntibioticsPUMPING huge amounts of ocean
water onto the West Antarctic ice
sheet could stop it collapsing and
raising sea levels so much that they
would threaten cities like New York.
But researchers who explored the
idea admit the intervention would
require an unprecedented effort
in one of the harshest places on
the planet. It would cost hundreds
of billions of dollars and could
devastate ecosystems there.
Five years ago, studies suggested
that the West Antarctic ice sheet
had begun an unstoppable collapse.
While the process would take
centuries, it would raise sea levels
enough to hit major coastal cities.
So Anders Levermann of the
Potsdam Institute in Germany and
his colleagues simulated the idea
of pumping ocean water onto the
sheet, adding it either in liquid formor as snow. They say stabilising
the collapse would require at least
7400 gigatonnes of the stuff
over 10 years (Science Advances,
doi.org/c8jg). Levermann says he
is against global geoengineering
such as giant sunshades, but this
idea is different and more surgical.
Even if we agreed to do it, there
are big obstacles. About 145GW
of wind farm capacity would be
needed to power pumps, 12 times
that installed in Europe last year.
New turbine materials would be
needed to cope with the cold and the
area would become an “industrial
compound”, says Levermann.
Clive Hamilton at Charles Sturt
University in Australia says: “The
conditions under which such a
scheme could be implemented are
beyond anything feasible. It’s not
going to happen.” Adam VaughanDrastic geoengineering
could help stem rising seas
hearing loss, Peter Steyger at
Creighton University in Nebraska
and his colleagues tested the
effects of one such drug,
gentamicin, on hearing in mice.
They found that infection and
inflammation left ion channels in
sensory hair cells (pictured) more
permeable to gentamicin, leading
to more of it being taken up by the
sensitive cells in the cochlea of the
inner ear. This amplified the toxic
effects of the drug on the cells.
Steyger and his team found
that one particular protein, called
TRPV1, facilitated gentamicin’s
entry into hair cells in the
presence of inflammation or
an immune response. Mice
bred without working TRPV
were protected from hearing
loss caused by gentamicin
(Science Advances, doi.org/c8jn).
Steyger hopes new techniques
that can identify microbes
more rapidly will mean doctors
may soon be less reliant on
broad-spectrum antibiotics
to treat newborns. RPSfrequency of less than 1kHz,
or 1000 times per second. In
contrast, Tee’s sensors send back
signals at 9Mhz, or 9 million
times per second.
The team designed different
types of sensors to better mirror
human touch. One responded to
quick, dynamic changes, another
to static forces, producing signals
that increased in frequency as
the force on it increased. A third
type sensed temperatures.
Tee and his colleagues then put
the skin onto a prosthetic hand
that grasped a hot cup of coffee
and found that all three types
of sensations were recorded
(Science Robotics, doi.org/c8jq).
“[This] has the potential to
greatly simplify and make it
possible for robots to have whole-
body skin, just like humans,” says
Tee. Another possible use of the
skin could be to cover prosthetic
limbs. This might one day help
people use them better, and
restore sensation to those who
have lost it. Ruby Prosser ScullyMA
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ROME/SPLNews In brief