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Mailing freeze-dried mouse sperm on a postcard

Have you ever worried about a fragile parcel breaking in the post? Scientists stress about this all the time – sometimes because they don’t want to break precious bottles of mouse sperm, sent between institutions for research.

A happy new year card in japanese, with freeze-dried mouse sperm attached in plastic packets.
A Happy New Year card with freeze-dried mouse sperm attached. Credit: Daiyu Ito, University of Yamanashi

Now, Japanese scientists have come up with a comical but handy way to transport sperm – by freeze-drying it on a plastic sheet and attaching it to a postcard.

“The postcard strategy was easier and cheaper compared to any other method,” says Daiyu Ito of the University of Yamanashi in Japan. “We think the sperm never expected that the day would come when they would be in the mailbox.”

Freeze-dried mammalian sperm had previously been sent to the International Space Station to study the effect of radiation on baby mice, but it was sent in small glass bottles – if they broke, the sperm couldn’t be used. This was a problem (apparently, large volumes of the stuff are needed for research).

So the team went searching for a new preservation method. They ended up putting freeze-dried mouse sperm on a plastic sheet in weighing paper and attaching this to a card.

The scientists sent the postcard more than 200 kilometres, and one scientist even attached some sperm as a gift to a Happy New Year card. The sperm was then able to produce baby mice.

The ability to easily and inexpensively send sperm across the world, the team says, will be vital to future scientific research.

The research is published in iScience.

The hipsters were right: craft beer is different

Beer snobs rejoice – science has found that craft beer is distinctly different to mass-produced beer.

A new study published in Scientific Reports has used mass spectrometry to suss out the proteins found in 23 different styles and brands of beer.

“Craft beer was strikingly different to beer from multinational breweries,” says the University of Queensland’s (UQ) Ben Schulz, co-author of the paper.

Two men hold up glasses of beer.
Dr Ben Schulz and Ed Kerr enjoy a well-earned beer. Credit: Ho Vu

“Our initial assumption was that there would be a difference between different styles of beers, such as lagers, pale ales, IPAs and stouts, but the results proved otherwise.”

Proteins are what give beer its sensory properties, from flavours to aromas to mouthfeel.

“The ‘beer proteome’ – or the full set of proteins in a beer – is critical in controlling these factors, and is dependent on the ingredients, the yeast used for fermentation, and the overall beer-making process,” explains Schulz.

First author Edward Kerr from UQ concludes: “We’re excited about using these techniques to understand and improve the beer-making process for non-barley gluten-free beers and with different types of yeast.”

Hidden exoplanets uncovered

Astronomers have spied several new exoplanets around a nearby star, L 98-59, just 35 light years from Earth. They include a rocky world with half the mass of Venus, as well as an ocean world that may be 30% composed of water, and the first hints of a planet in the habitable ‘Goldilocks’ zone.

Artist's impression of a planet on the left with a star on the right on a black starry background
This artist’s impression shows L 98-59b, one of the planets in the L 98-59 system 35 light-years away. Credit: ESO/M. Kornmesser

“The planet in the habitable zone may have an atmosphere that could protect and support life,” says María Rosa Zapatero Osorio from the Centre for Astrobiology in Madrid, Spain, and co-author of the study published in Astronomy & Astrophysics.

These planets were first discovered with NASA’s TESS satellite, and then followed up by instruments in ground-based observatories – the ESPRESSO spectrograph on the Very Large Telescope and the HARPS instrument on the La Silla 3.6-metre telescope, both run by the European Southern Observatory in Chile.

Co-author Olivier Demangeon says: “We, as a society, have been chasing terrestrial planets since the birth of astronomy and now we are finally getting closer and closer to the detection of a terrestrial planet in the habitable zone of its star, of which we could study the atmosphere.”

Why don’t poisonous frogs and birds harm themselves?

A team of US researchers has discovered that animals can produce ‘toxin sponges’ that absorb their own poison and prevent them from hurting themselves.

Many animals use toxins to protect themselves. These toxins can induce paralysis or cardiac arrest in predators by interfering with key proteins that control electrical impulses in neurons, muscles and the heart.

A yellow frog on dirt
The golden poison frog, Phyllobates terribilis. Credit: Chris Wellner, Smithsonian’s National Zoo

But some animals, such as New Guinea’s poisonous pitohui birds and several frog species in Colombia, don’t produce the toxins themselves. Instead, they get them from insects they eat, and then store the toxins for long periods.

Researchers have long wondered how these birds and frogs protect themselves, as previous studies haven’t suggested they have resistance mechanisms. This new study in the Journal of General Physiology has found that these species may have ‘sponge’ proteins to mop up the toxins.

“These sequestration strategies might not only offer a general means of toxin protection, but could also act in pathways involved in safely transporting and concentrating toxins in key defensive organs such as the skin,” says Daniel L Minor, Jr, co-author from the University of California, San Francisco.

“Understanding these pathways may lead to the discovery of antidotes against various toxic agents.”

Quantum crystal could detect dark matter

A tiny 2D crystal might help us finally sense dark matter, according to physicists from the National Institute of Standards and Technology (NIST) in the US.

Two physicists in a lab wearing sunglasses, working with lasers.
NIST physicists John Bollinger (left) and Matt Affolter adjust the laser and optics array used to trap and probe beryllium ions in the large magnetic chamber (white pillar at left). Credit: Jacobson/NIST

As described in a paper in Science, the team confined 150 electrically charged atoms in a magnetic field so that they arranged into a 2D crystal. The team then linked or ‘entangled’ the atoms, so they could measure how the crystal as a whole vibrated (how the 2D surface moves up and down) just by monitoring the changes in the collective spin, an inherent property of all particles.

This could help us find the mysterious substance of dark matter.

“We know 85% of the matter in the universe is made of dark matter, but to date we do not know what dark matter is made of,” says NIST theorist Ana Maria Rey.

One leading theory is that dark matter is composed of subatomic particles that interact only weakly with regular matter.

“Ion crystals could detect certain types of dark matter — examples are axions and hidden photons — that interact with normal matter through a weak electric field,” explains senior author John Bollinger.

The dark matter could cause NIST’s crystal to vibrate, which can be spotted by physicists measuring the spin.

The team hopes to increase the number of ions in the crystal to 100,000 and make a 3D crystal, improving its sensitivity thirtyfold.

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