New Scientist - USA (2020-03-28)

28 March 2020 | New Scientist | 19

Genetic modification

Marine biology Medical technology

An electric ride

really is better

Electric cars now have a

smaller climate change

impact than their fossil

fuel counterparts in

almost every part of

the world, according

to researchers who say

the vehicles are the best

environmental choice even

where power grids haven’t

gone fully renewable

(Nature Sustainability,

DOI: 10.1038/s41893-

020-0488-7).

Interstellar visitor

may be cracking up

The interstellar comet

2I/Borisov is starting to

brighten, suggesting it

may be breaking apart as

it makes its way out of our

solar system. Outbursts

from the comet in early

March have more than

doubled its brightness,

suggesting it is emitting

material after being

heated by the sun.

Random walks

take maths prize

Mathematicians Hillel

Furstenberg and Gregory

Margulis have jointly won

the 2020 Abel prize, worth

7.5 million Norwegian

kroner (£540,000). They

both invented techniques

that use a “random walk”

approach to study various

mathematical objects.

Brain cells turned

into cyborg tissue

NERVE cells in living animals

have been genetically modified

to produce conducting polymers

on their surfaces, giving them

new electrical properties.

The work, which could enable

us to electrically control specific

groups of cells, may lead to new

treatments for epilepsy and

better ways of connecting

prosthetic limbs to nerves,

says Zhenan Bao at Stanford

University in California.

FISH are burdened with lots more

parasitic worms than 40 years ago.

Anisakis worms infect marine

fish, squid and marine mammals,

and can be in fish used for sushi.

Chelsea Wood at the University

of Washington in Seattle and

her team analysed changes in

abundance between 1978 and

2015, looking at the average

number of these parasites per fish

from 123 studies spanning 215

species. They found a 283-fold

increase over that time (Global

Change Biology, doi.org/dp6r).

These worms start life in the

intestines of marine mammals,

which excrete them. They can then

infect fish, small crustaceans or krill.

Humans can ingest these worms

by eating infected fish that is raw,

smoked or improperly frozen. They

can’t survive in us, yet can cause

vomiting and diarrhoea. But Wood

says we needn’t be overly worried,

as the seafood processing industry

and sushi chefs are skilled at

spotting and removing the worms.

The reason for the increased

abundance of the parasites isn’t

clear, but Wood says that it may be

linked to a rise in marine mammal

numbers from the 1970s onwards.

Warming seas may also increase

Anisakis reproduction, she says.

Donna Lu

At present, electrical implants,

such as those used for treating

Parkinson’s disease, often use

metal electrodes pushed into the

brain. One of the disadvantages is

that there is no way to use these to

control the activity of particular

types of neuron.

Bao and her team genetically

modified specific cell types to

make an enzyme on their surface

that joins small molecules, known

as monomers, to make a chain.

The resulting polymer can be an

electrical conductor or insulator,

depending on the molecules used.

The team did this first with

Ultrasound can

check our brains

ULTRASOUND head scans could be

used to quickly diagnose strokes.

Ultrasound produces pictures

of a body’s insides by transmitting

and recording the echoes of

sound waves. It is most commonly

used to monitor fetuses during

pregnancy. Now, Lluís Guasch

at Imperial College London and

his colleagues have developed

a version that produces images

of our brains.

Until now, ultrasound wasn’t

used to scan the brain because the

resulting picture was distorted by

the skull. But the new technique

overcomes this by pairing the

recordings with an algorithm that

takes account of any interference

produced by the skull (npj Digital

Medicine, doi.org/dp6x).

This method could be easily

employed outside the hospital

setting as the equipment is

relatively small and inexpensive.

This could be useful for treating

stroke. People who have a stroke

must be diagnosed quickly so the

right treatment can be given to

avoid further damage.

Typically, this is only possible

with brain imaging, using MRI

or CT scans. Both of these can

only be done in hospital, which

usually means a delay.

Jason Arunn Murugesu

animal and human cells in a dish,

then with miniature human

brain-like structures in the lab and

finally in living nematode worms,

which were soaked in monomers.

The researchers showed that

targeted nerve cells become

coated in a polymer of choice, and

that this alters the behaviour of

the cells as expected. For instance,

targeting the neurons that control

movement in nematode worms

made them less likely to move

forward, or more likely to make

sharp turns, depending on the

type of polymer (Science,

doi.org/dp64). Michael Le Page

Fish parasite numbers have

soared in recent decades

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Really brief

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