2019-06-01_New_Scientist

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1 June 2019 | New Scientist | 17

Social networks

Drones Ecology

Women less likely
to receive CPR

An analysis of more than
5700 cardiac arrests in the
Netherlands has found that
only 68 per cent of women
received a resuscitation
attempt from a bystander,
compared with 73 per cent
of men (European Heart
Journal, doi.org/c55n). This
may be because symptoms
more commonly reported
by women than men – such
as fainting, fatigue and
vomiting – are less obvious
than chest pain.

Chimps’ ingenuity
earns them a treat

Chimpanzees in West Africa
have learned how to get
hold of tortoise meat. The
apes, in Gabon, were seen
bashing the soft underside
of the shells against tree
trunks to crack them open
and get to the animals’
flesh (Scientific Reports,
doi.org/c56k).

Keeping cool
with wood

A material made by
treating wood with
hydrogen peroxide
could keep houses cool.
It reflects visible light
and only absorbs very
low levels of near-infrared
light, so would transmit
barely any heat from the
sun indoors (Science,
doi.org/c57x).

How to burst your
social media bubble

AS EUROPEAN parliamentary
elections neared last week,
Facebook was again awash with
misinformation. In response,
it barred dozens of suspicious
pages and groups.
But new accounts can pop up
very quickly, so another approach
is to try to prevent misinformation
from reverberating in so-called
echo chambers. These segregated
groups lack the range of opinions
that can help counter fake news.

A SHAPE-SHIFTING drone is ready
for almost any environment, with
the ability to transform itself into
a car on command.
Called FSTAR, it can navigate a
range of surfaces and environments,
making it potentially useful for
search and rescue. With a wheel
and a propeller on each of its four
legs, it is about 35 centimetres long.
During operation, a person uses
a controller to steer the drone.
When flying, its legs are parallel
to the ground. When it lands and
receives the command to turn into
a car, its legs lower so that its
wheels can touch the ground.
FSTAR’s wheels are slanted,

which offers an advantage over
vertical wheels. “They are more
stable, especially on smooth
surfaces, so you can drive at
a higher speed,” says David
Zarrouk at Ben-Gurion University
of the Negev in Israel, one of the
drone’s creators.
FSTAR can drive at up to
2.6 metres per second and reach
15 metres per second when flying.
In tests, it could crawl over rubble,
lower itself to squeeze under small
gaps or fly over bigger obstacles.
Work on the drone was presented
at the International Conference
on Robotics and Automation in
Montreal, Canada. Yvaine Ye

A new analysis has found a few
simple tweaks to combat this.
Kazutoshi Sasahara at Indiana
University and his colleagues have
shown that the structure of social
networks makes echo chambers
inevitable – especially the ability
to unfollow or unfriend whoever
you like. This means it is easy to
cut off views you disagree with.
They also found that when
social networks recommend that
users follow friends of friends –
people who are likely to share
similar views – echo chambers
form more than twice as quickly.
Sasahara and his colleagues

Downsized future
for life on Earth

ANIMALS, collectively speaking,
are getting smaller, as humans
drive big beasts such as elephants
to extinction, with far-reaching
consequences for ecosystems.
Previous studies have shown
that bigger animals are at a greater
risk of dying out. Now a model of
the next 100 years predicts that
habitat destruction, poaching and
other pressures will cause an
overall decline in body size.
Researchers led by Rob Cooke
at the University of Southampton,
UK, modelled the future of 15,
endangered species. Critically
endangered ones such as the black
rhinoceros were given a 99 per
cent likelihood of disappearing,
while vulnerable ones had a 10 per
cent chance. The results showed
the loss of big species would see
the average body mass of animals
drop around 9 per cent from today,
to 64.1 grams in 2119 (Nature
Communications, doi.org/c56x).
This matters, and not just
because we care about charismatic
megafauna – tigers and so on. Big
species can be vital for ecosystems,
such as herbivores keeping grass
productive. They also perform
roles that help us, like scavenging.
For example, where vultures have
declined, disease has risen.
Adam Vaughan

suggest that social networks could
try to prevent echo chambers by
making it harder for people to
sever connections with those
with different opinions. Users
should be encouraged to “snooze”
an account rather than stop
following it entirely or be alerted
when they are about to unfollow
their last source of a particular
type of information.
Similarly, the researchers say
social networks should avoid
recommending new connections
that are likely to reinforce
opinions too strongly (arxiv.org/
abs/1905.03919). Douglas Heaven

Transformer flies, drives and


squeezes past obstacles


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Really brief


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