18 | New Scientist | 25 January 2020Animal behaviourBricks grown from
bacteria can multiplyLIVING concrete made from
bacteria could one day help to
reduce the environmental impact
of the construction industry.
Wil Srubar at the University of
Colorado, Boulder, and his team
used Synechococcus bacteria to
create building blocks in a variety
of shapes (one is pictured below).
The team combined the bacteria
with gelatin, sand and nutrients in
a liquid mixture, then placed thisPregnancy loss
can lead to PTSDONE in six women who have
an early miscarriage or ectopic
pregnancy have symptoms of
post-traumatic stress disorder
nine months later. As people can
experience PTSD symptoms for
months, it is important they are
able to get psychological support
should they need it, say the
researchers behind the work.
It is estimated that women
have more miscarriages than live
births over their lifetime. But the
psychological effects are often
“brushed under the carpet”, says
Jessica Farren, an obstetrician
and gynaecologist at St Mary’s
Hospital in London.
Women often don’t tell their
friends, family and colleagues
that they are pregnant until after
their 12-week scan. If that scan
reveals a miscarriage, they may
feel unable to tell people, so miss
out on support, says Farren.Mental health BiotechnologyRETURNING a thrown ball is one
of the most quintessential dog
behaviours. But research suggests
that it may predate dogs, as some
wolf pups seem to enjoy the game.
The first observations of wolf
pups fetching balls for people
happened unexpectedly, says
Christina Hansen Wheat at
Stockholm University in Sweden.
Her team studies the behavioural
changes involved in domestication
by looking at dogs and wolves. The
team hand-reared wolf pups from
three litters once they were 10 days
old. When they were 8 weeks old,
the pups were put through a series
of behavioural tests.
One of these involved having
an unfamiliar person toss a tennis
ball across the room to see how
much it captured the pup’s
attention. Almost all of the pupsfrom the 2014 and 2015 litters
flatly ignored the ball. One gave
it a passing glance.
The next year, one pup shocked
the scientists by not only chasing
down the ball and snatching it up,
but bringing it back to the person
when coaxed.
Hansen Wheat was watching
from another room. “I literally got
goosebumps,” she says, adding that
dogs’ ability to interpret socially
communicative behaviour from
people – like following a person’s
cues to bring a ball back – has been
considered a consequence of the
domestication process.
In the end, three wolves from the
2016 litter fetched the balls, and
one did it on all three trials of the
test. Others played with the ball
but wouldn’t return it (iScience,
doi.org/djkv). Jake BuehlerHowl’s that! We’ve seen
wolf pups fetching balls
in a mould. With heat and
sunlight, the bacteria produced
calcium carbonate crystals around
the sand particles, in a process
similar to how seashells form.
When cooled, the gelatin
solidified the mixture into a gel.
The team then dehydrated the
gel to toughen it, with the entire
process taking several hours.
The researchers liken the
material to concrete – a mix of
gravel, sand and cement. But its
mechanical properties are closer
to mortar, a weaker material
usually made with cement
and sand, says Srubar.
An advantage of using bacteria
to create the concrete is that if it
isn’t dehydrated entirely, it can
still grow. With additional sand
and nutrient solution, a growing
brick can be split to create two
bricks (Matter, doi.org/ggh2k9).
The process has the potential to
make energy intensive concrete
production less environmentally
damaging because of its reliance
on photosynthesis. Donna LuShe and her team asked
737 women who experienced
a miscarriage during the first
12 weeks of pregnancy or an
ectopic pregnancy – in which
the embryo attaches outside the
uterus, causing pregnancy loss –
to complete questionnaires
designed to diagnose anxiety,
depression and PTSD. The
questionnaires were sent one
month after pregnancy loss,
and then again three and
nine months after the losses.
Nine months after a pregnancy
loss, 18 per cent of women met the
criteria for a PTSD diagnosis, 17 per
cent reported anxiety and 6 per
cent of women had symptoms of
moderate to severe depression
(American Journal of Obstetrics
and Gynecology, doi.org/djkz).
At the moment, the National
Health Service in England
doesn’t routinely offer
psychological support and
counselling to everyone who
experiences pregnancy loss,
says Farren. Jessica HamzelouKL
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