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Seventeen month old toddler looking at a laptop

A study in Canada found that two year olds spend an average of 2.4 hours a day looking at screens, with this increasing to 3.6 hours a day for three year olds. Credit: BSIP/UIG/Getty

Epidemiology

Children glued to screens show delays in key skills

Greater screen time at age two corresponds to poorer scores on developmental test at age three.

Children who spend much of their time staring at screens tend to score badly on tests of cognitive and emotional development. But does screen time itself hinder growth? Or are children with developmental difficulties allowed to spend more time bathing in a screen’s glow?

To answer this question, Sheri Madigan at the University of Calgary in Canada and her colleagues analysed the development and screen habits of nearly 2,500 children in Canada. The team found that, compared with those exposed to relatively low levels of screen time, children who spent more time in front of a screen at age two scored worse on a developmental test at age three, and children who racked up more screen time at age three scored worse on the test at age five.

By contrast, poorer performance on the test did not predict that a child would spend more time looking at tablets and similar devices. This suggests that extensive screen time precedes low scores on developmental tests.

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Camera-trap image of Dendrohyrax interfluvialis

Some tree hyraxes scream in the night, but the newly identified Dendrohyrax interfluvialis (above, camera-trap image) utters a complex series of squawks, rattles and barks. Credit: J. F. Oates et al./Zool. J. Linn. Soc.

Zoology

A bark in the dark reveals a hidden hyrax

Its neighbours scream, but a new species of tree hyrax — a cousin of the elephant — unleashes a rattling bark.
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Plastic detritus from snacks and meals floats in the Red Sea. Marine sampling shows that food waste accounts for nearly 90% of plastic pollution at some locales. Credit: Andrey Nekrasov/Barcroft Media/Getty

Ocean sciences

Humanity’s fast-food habit is filling the ocean with plastic

Food bags, drink bottles and similar items account for the biggest share of plastic waste near the shore.
Conceptual artwork of a pair of entangled quantum particles.

An artist’s impression of ‘entangled’ particles, which share properties even at a distance. Entangled photons can be used to help secure a multi-party video meeting. Credit: Mark Garlick/Science Photo Library

Quantum information

Quantum keys dial up tamper-proof conference calls

A new experiment efficiently distributes the highly secure keys to four parties instead of the typical two.
Farmers harvest pineapples in a field.

Workers harvest pineapples in Lingao County, China. Less than one-third of the money spent on food eaten at home reaches farmers. Credit: Yuan Chen/VCG/Getty

Economics

Poor harvest: farmers earn a pitiful fraction of the money spent on food

The bulk of consumer food spending around the world ends up in the coffers of distributors, processors and other parties beyond the farm gate.
A woman wearing a protective face mask splashes her hands in a jet of water

A pedestrian seeks relief from searing temperatures in Spain, where a high proportion of heat-related deaths have been linked to climate change. Credit: SALAS/EPA-EFE/Shutterstock

Climate change

More than one-third of heat deaths blamed on climate change

Warming resulting from human activities accounts for a high percentage of heat-related deaths, especially in southern Asia and South America.
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