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A Blatella asahinai cockroach carrying eggs rests on a green leaf.

The Asian cockroach (Blattella asahinai) is the closest living relative of the German cockroach.Credit: Apurv Jadhav/ephotocorp via Alamy

How cockroaches took over the world

A ubiquitous cockroach species originated in South Asia but was domesticated in Europe, and spread around the world from there, suggests a genomic analysis. Researchers analysed the genomes of hundreds of German cockroaches (Blattella germanica) collected from 17 countries. They found that around 390 years ago, B. germanica began to spread east from South Asia, with the rise of European colonialism and the emergence of international trading companies such as the Dutch and British East India Companies. Around a century later, the German cockroach hitched a ride into Europe, and conquered the world from there.

Nature | 4 min read

Reference: PNAS paper

Mars lander will be warmed by americium

A European Mars mission will use a pioneering nuclear-powered device that harnesses the radioactive decay of americium to keep its components warm — a first for spacecraft. ExoMars will launch in 2028 and will include Europe’s first Mars rover, named ‘Rosalind Franklin’. The European Space Agency (ESA) had to radically rethink the mission to proceed without the involvement of Russian space agency Roscosmos, which was meant to build the lander. It will now use a new, European-designed lander and rely on NASA to fill in the rest.

Nature | 4 min read

Why some songs make us feel like dancing

The most dance-inducing rhythms are neither too predictable nor too surprising. An intermediate amount of syncopations — rhythmic patterns that occur when unexpected beats are emphasized — was the sweet spot for making 60 study participants want to dance. Brain activity measurements suggest that this ‘groove experience’ is triggered by the dorsal auditory pathway, which connects the auditory-information-processing region with movement areas.

Scientific American | 4 min read

Reference: Science Advances paper

Features & opinion

How scientists balance work and faith

“I think there is the perception sometimes that other scientists won’t take you seriously if you talk about your faith,” says sociologist Elaine Howard Ecklund, who has surveyed scientists’ attitudes to religion for the past 20 years. Many religious scientists say they struggle to be open about their faith at work, partly because of a culture of ‘assumed atheism’, says sociologist Christopher Scheitle. Five religious researchers who spoke to Nature confirmed they felt awkward having conversations about their faith at work, though their experiences differ from country to country.

Nature | 10 min read

The researchers behind DeepLabCut

Neuroscientists Mackenzie and Alexander Mathis met as graduate students, got married and — together with colleagues — created the blockbuster motion-tracking tool DeepLabCut. The tool uses a machine-learning algorithm to track a lab animal’s body parts in videos, without the use of intrusive markers. It’s been used to study behaviour in everything from fruit flies to horses — but animals that camouflage themselves create unique challenges. “There was a student who had tweeted some videos of octopus in the Red Sea — as a human, you couldn’t even see the octopus until it moved,” Mackenzie Mathis says. “That was quite amazing to see.”

Nature | 8 min read

How to organize your lab space

Lab organization can seem intimidating, or even boring — but it is neither, say Marissa Coppola and Jessica Tsai, who set up a lab to study the genomic drivers of paediatric brain tumours. They offer these tips:

• Create a planning spreadsheet with tabs for each experiment category to identify shared resources

• Design a floorplan, considering how the different lab spaces might affect each other

• Try several different set-ups for equipment and supplies to pinpoint the ideal configuration

• Maximize storage — fill blank walls with shelves and use space under counters

• Take the opportunity to visit neighbouring labs and get inspiration from how their spaces are organized

Nature | 6 min read

Infographic of the week

An infographic illustrating details of how a previously unknown type of cell in the adrenal gland boosts parental care in mice.

In oldfield mice (Peromyscus polionotus subgriseus), both mums and dads care for offspring, whereas in deer mice (Peromyscus maniculatus), mothers usually do all the work. This difference in parenting behaviour seems to arise, in part, because of a previously unknown type of hormone-producing cell in the adrenal gland of oldfield mice, which is not present in deer mice, writes neuroscientist Jessica Tollkuhn.

As well as having the expected cellular layers — the zona glomerulosa (zG), zona fasciculata (zF), zona reticularis (zR) and medulla — the adrenal glands of oldfield mice have a layer dubbed the zona inaudita (zI). This layer has high expression of the enzyme AKR1C18, which can convert the hormone progesterone to the molecule 20α-OHP. When 20α-OHP reaches the brain, it is converted to allo-diol. This molecule inhibits signalling in neurons that act through the GABAA receptor, ultimately boosting parental-care behaviours. (Nature News & Views | 9 min read, Nature paywall)

Reference: Nature paper


“The pupils were often regarded as objects for research, rather than first and foremost as children whose treatment should be firmly focused on their individual best interests alone.”

Children at a specialist school for haemophiliacs were among the 30,000 people infected with HIV or hepatitis C from blood and blood products in the United Kingdom, writes chair Brian Langstaff in the report from the public inquiry into the scandal. (The Guardian | 5 min read)

Reference: Infected Blood Inquiry report