A polariton filter turns ordinary laser light into quantum light

An international team of researchers led out of Macquarie University has demonstrated a new approach for converting ordinary laser light into genuine quantum light.

Their approach uses nanometre-thick films made of gallium arsenide, which is a semiconductor material widely used in solar cells. They sandwich the thin films between two mirrors to manipulate the incoming photons.

The photons interact with electron-hole pairs in the semiconductor, forming new chimeric particles called polaritons that carry properties from both the photons and the electron-hole pairs. The polaritons decay after a few picoseconds, and the photons they release exhibit distinct quantum signatures.

The teams’ research was published overnight in the journal Nature Materials.

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Trees remember heatwaves

An Aussie eucalypt can ‘remember’ past exposure to extreme heat, which makes the tree and its offspring better able to cope with future heatwaves, according to new research from Macquarie University.

This finding could have important implications for restoring ecosystems and climate-proofing forestry, as the number of hot days and heatwaves increase due to climate change.

“Unlike animals, which can bury deeper into the soil or flee to cooler locations, plants are stuck in one spot and so must be able to withstand extreme conditions in situ,” says Dr Rachael Gallagher, senior author of the paper published in the journal Functional Ecology.

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The Milky Way is warped

The first accurate 3D map of our galaxy reveals its true shape: warped and twisted.

Astronomers from Macquarie University and the Chinese Academy of Sciences have used 1339 ‘standard’ stars to map the real shape of our home galaxy in a paper published in Nature Astronomy today.

They found the Milky Way’s disc of stars becomes increasingly ‘warped’ and twisted the further away the stars are from the galaxy’s centre.

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Cane toads: what they do in the shadows

Cane toads are picking up some shady habits, according to a new study co-authored by a Macquarie University researcher.

Toads in Western Australia have been spotted awake and active during the day in deeply shaded habitats, despite the species usually being nocturnal in Australia and other parts of the world.

However nearby cane toad populations at more exposed sites remained only active at night.

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Promiscuous females and their role in evolution

Males have to make less of an effort to mate with promiscuous female fruit flies, making the quality and quantity of their semen all the more important in the competition to fertilise the females’ eggs.

This also leads to male flies repeatedly mating with the same female, according to a paper published last week in Nature Communications, by researchers from Macquarie University, the University of Oxford and the University of East Anglia, who looked into the eyes of thousands of fruit flies.

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The quest for the missing proteins in rice

Researchers have identified over 5,700 new proteins in rice and are calling for a global effort to find the remaining missing proteins, in a new study co-authored by Macquarie University.

The international team of scientists from Australia, Iran and Japan say there’s an estimated 35,000 proteins encoded by the rice genome, and yet we still don’t have experimental evidence for 82 per cent of them.

This is important because rice is the major food source for more than half the world’s population, and in order for it to grow in warmer climates and with less water we will need to better understand rice at the molecular level. Continue reading The quest for the missing proteins in rice

The shape of a perfect storm: saving lives by predicting firestorms

Correction: an earlier version stated the tool is being formally trialed by the NSW Rural Fire Service. It is currently in use, but formal trials ended in 2016.

Firestorms are a nightmare for emergency services and anyone in their path. They occur when a bushfire meets a ‘perfect storm’ of environmental conditions and creates a thunderstorm.

Dr Rachel Badlan and Associate Professor Jason Sharples are part of a team of experts from UNSW Canberra and ACT Emergency Services that has found the shape of a fire is an important factor in whether it will turn into a firestorm.

Fires that form expansive areas of active flame, rather than spreading as a relatively thin fire-front, are more likely to produce higher smoke plumes and turn into firestorms, the researchers found.

This finding is being used to underpin further development of a predictive model for firestorms. The model was trialed in the 2015 and 2016 fire seasons by the ACT Emergency Services Agency and the NSW Rural Fire Service, and now forms part of the national dialogue around extreme bushfire development.  

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Slipped discs: robot shows it’s not all bending and twisting

High res photos available below.  

Video of Dhara and the bending robot available here

Some slipped disc injuries might be caused by movements other than the commonly blamed bending and twisting, according to new research by South Australian engineers.

It’s a finding that will lead to a better understanding of the motions that put people at greatest risk of a slipped disc and help develop more robust guidelines for safe lifting.

Continue reading Slipped discs: robot shows it’s not all bending and twisting

Indonesian and Australian scientists test new TB vaccine targets

Better vaccines are needed for the global fight against tuberculosis (TB). The Global Fund reports an estimated nine million new cases globally per year of TB, which is second only to AIDS as the world’s most deadly infectious disease.

Indonesia had more than 320,000 reported cases in 2014 according to the World Health Organization, while Australia’s reported cases were just over 1,000. But the rise of drug-resistant TB poses a threat to all countries.

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Can sunshine help prevent pneumonia?

The possibility of a link between vitamin D deficiency and pneumonia is being investigated in two studies by Indonesian and Australian scientists in Indonesia.

They’re tracking the incidence and severity in early childhood of respiratory tract infections, including the common cold, asthma, pneumonia, and bronchiolitis, in hospitals and the community, in the hope of providing more information for treatment and management for respiratory diseases.

A post-delivery mother with a midwife, after cord blood has been collected
A mother and her newborn with a midwife, after cord blood has been collected. Credit: Mr Noor Qodri H

Pneumonia is the number one killer of children under five in the country, and around six million young Indonesians suffer from it each year, according to a 2008 study. This collaboration is going to update those 2008 figures, and hopefully lower them – while trying to find the causes of it and other respiratory tract infections. Continue reading Can sunshine help prevent pneumonia?