People of different nationalities appear to vary in their use of hand gestures, according to a study that seems to reinforce the idea that Italians, in particular, “talk with their hands”.

and her colleague , both at Lund University in Sweden, asked 12 people from Sweden and 12 from Italy to describe a clip from the children’s TV show Pingu to a friend who hadn’t seen it, while examining their gestures.

“Italians do gesture more,” says Graziano on a video call, gesturing emphatically herself, which she puts down to her upbringing in Naples, Italy. In the study, the Italians made an average of 22 gestures per 100 words, compared with the Swedes’ 11.

But more interesting was the difference in the function of the gestures, says Graziano. The Swedes mostly used “representational gestures” to illustrate the events and actions of the story, for example mimicking a rolling pin when describing baking.

The Italians made these motions as well, but also had more “pragmatic gestures” that comment on the story or introduce new information, such as a hand movement to indicate a new character.

This suggests that the two cultures think differently about the way a narrative is produced, says Graziano. Gestures can reflect what cultures deem important about the content and purpose of a story, she says.

Free newsletter

Sign up to The Daily

Sign up to newsletter

at Stanford University in California says that exactly why these results occurred is unclear, but they suggest that “cultural conventions of understanding and explaining brief episodes are driving the gestures”. Tversky wants to see further research in larger groups of people with a more diverse mix of nationalities.

Graziano hopes to now study the gestures used in different types of discourse, and with different relationships between the speakers, to shed more light on how various cultures use gestures to communicate and tell a story.

The relationships between plants and the fungi that colonise their roots are responsible for locking away a huge amount of carbon underground – maybe equivalent to more than one-third of global emissions from fossil fuels.

Almost all land plants on Earth have a symbiotic relationship with fungi that live in the soil around their roots, trading the carbon they draw from the air for nutrients like nitrogen and phosphorus.

These mycorrhizal fungi store the carbon they get from their plant partners in their tissues and the surrounding soil, thus keeping it out of the atmosphere. But despite the interest in nature-based solutions to climate change, mycorrhizal fungi have been largely overlooked, says at the University of Cape Town, South Africa. So, she and her colleagues set out to calculate just how much carbon plants might be transferring to these fungi.

By scouring data from dozens of scientific studies on the relationships between plants and fungi, the researchers estimated that between 3 and 13 per cent of the carbon dioxide_��that plants pull out of the atmosphere ends up in the fungal tissue.

The team then used global data on which plants live where, how productive they are and which fungi they are associated with to estimate that about 13.1 gigatonnes of CO₂ is transferred to fungi each year – equivalent to around 36 per cent of annual emissions from fossil fuels around the world.

What isn’t clear is how long that carbon stays locked up underground, says Hawkins. While some will remain there even after the fungi die, bound to soil particles or reused by other plants, some will be released back into the atmosphere. And since most of the data was based on snapshots of fungal activity at a certain place and time – there was almost no data from Africa, for example – there are big gaps that add a great deal of uncertainty to the estimates.

at the University of British Columbia in Canada says the work highlights fungi’s important role in the carbon cycle. “This is the first time someone has come up with numbers for how much carbon we’re talking about globally,” she says.

But at the University of Amsterdam in the Netherlands points out that by focusing only on mycorrhizal fungi, the research is missing part of the picture. Saprotrophic fungi – the kind that feast upon dead organic material – make up a much larger portion of the fungal population and play a huge role in the carbon cycle by releasing CO₂ through decomposition. “They really determine how much carbon is returned to the atmosphere,” she says.

Hawkins hopes that an improved understanding of the relationship between plants and fungi will help us to better plan nature-based climate solutions like forest restoration. “There are a lot of failed projects, where trees were planted at vast expense but then died,” she says. “Knowing more about which trees grow best with which fungal partners can help these projects succeed.”

Fertilisers derived from recycled human urine and faeces are just as safe and effective as conventional ones, according to tests on cabbage plants. Using human waste in this way could help alleviate the fertiliser shortage that is contributing to rising food prices – if people can be convinced to use them.

Nitrogen-based fertilisers are manufactured in an energy-intensive process using natural gas as a raw material. Human waste can be a good source of plant nutrients like nitrogen and phosphorus, but can also carry disease-causing pathogens and parasites, so needs to be carefully treated to make it safe. It is still used – sometimes untreated – as a fertiliser in some low-income countries, but has been largely abandoned in high-income nations.

at Agroscope in Zurich, Switzerland, and her colleagues compared cabbages grown using organic fertiliser derived from vinasse, a by-product of ethanol production, with fertilisers made from treated human urine and faeces.

The yield for cabbages grown with nitrified urine fertilisers (NUFs) was comparable to those grown with vinasse. Cabbages grown with faecal compost, or compost and NUFs together, had lower yields, but this fertiliser may increase soil carbon content in the long term, the study found.

The researchers also tested for more than 300 chemicals in the faecal compost, including pharmaceuticals, flame retardants and insect repellents. Just 6.5 per cent of these were detected, all at very low concentrations. Of the 11 pharmaceuticals detected in the compost, just two were found in the edible parts of the cabbage: the painkiller ibuprofen and the anticonvulsant and mood-stabilising drug carbamazepine. But the concentration of the latter was so low you would need to eat half a million cabbages to get a single dose.

“The products derived from recycling human urine and feces are viable and safe nitrogen fertilizers for cabbage cultivation,” Häfner said in a statement. “They gave similar yields as a conventional fertilizer product, and did not show any risk regarding transmission of pathogens or pharmaceuticals.”

The researchers estimate that, if correctly prepared and quality controlled, up to 25 per cent of conventional synthetic mineral fertilisers in Germany could be replaced by ones recycled from human urine and faeces. In some places, that trend is already under way. One of the NUFs they tested, called Aurin, has already been approved for agricultural use in Austria, Switzerland and Liechtenstein.

at ETH Zurich obtained similar results in yield and safety when . But getting people to use them can take some convincing. The Zulu farmers he worked with, like those from many cultures, have strong social taboos around human waste. However, long discussions about the process of making such fertiliser and a field trip to where this happens helped them overcome those. “Farmers are very practical people once they see that something works,” he says, although the farmers pointed out they might have a harder time convincing their customers.

If people can be convinced to overcome their squeamishness, fertilisers from recycled human excreta might make a serious dent in the fertiliser shortage. There are billions of people in the world and that is a lot of available nitrogen, says Wilde.