Jun 3, 2023

Eventually everything will evaporate, not only black holes

New theoretical research by Michael Wondrak, Walter van Suijlekom and Heino Falcke of Radboud University has shown that Stephen Hawking was right about black holes, although not completely. Due to Hawking radiation, black holes will eventually evaporate, but the event horizon is not as crucial as had been believed. Gravity and the curvature of spacetime cause this radiation too. This means that all large objects in the universe, like the remnants of stars, will eventually evaporate.

Using a clever combination of quantum physics and Einstein's theory of gravity, Stephen Hawking argued that the spontaneous creation and annihilation of pairs of particles must occur near the event horizon (the point beyond which there is no escape from the gravitational force of a black hole). A particle and its anti-particle are created very briefly from the quantum field, after which they immediately annihilate. But sometimes a particle falls into the black hole, and then the other particle can escape: Hawking radiation. According to Hawking, this would eventually result in the evaporation of black holes.

Spiral

In this new study the researchers at Radboud University revisited this process and investigated whether or not the presence of an event horizon is indeed crucial. They combined techniques from physics, astronomy and mathematics to examine what happens if such pairs of particles are created in the surroundings of black holes. The study showed that new particles can also be created far beyond this horizon. Michael Wondrak: 'We demonstrate that, in addition to the well-known Hawking radiation, there is also a new form of radiation.'

Everything evaporates

Van Suijlekom: 'We show that far beyond a black hole the curvature of spacetime plays a big role in creating radiation. The particles are already separated there by the tidal forces of the gravitational field.' Whereas it was previously thought that no radiation was possible without the event horizon, this study shows that this horizon is not necessary.

Falcke: 'That means that objects without an event horizon, such as the remnants of dead stars and other large objects in the universe, also have this sort of radiation. And, after a very long period, that would lead to everything in the universe eventually evaporating, just like black holes. This changes not only our understanding of Hawking radiation but also our view of the universe and its future.'

Read more at Science Daily

Mysterious dashes revealed in Milky Way's center

An international team of astrophysicists has discovered something wholly new, hidden in the center of the Milky Way galaxy.

In the early 1980s, Northwestern University's Farhad Yusef-Zadeh discovered gigantic, one-dimensional filaments dangling vertically near Sagittarius A*, our galaxy's central supermassive black hole. Now, Yusef-Zadeh and his collaborators have discovered a new population of filaments -- but these threads are much shorter and lie horizontally or radially, spreading out like spokes on a wheel from the black hole.

Although the two populations of filaments share several similarities, Yusef-Zadeh assumes they have different origins. While the vertical filaments sweep through the galaxy, towering up to 150 light-years high, the horizontal filaments look more like the dots and dashes of Morse code, punctuating only one side of Sagittarius A*.

The study will be published on Friday (June 2) in The Astrophysical Journal Letters.

"It was a surprise to suddenly find a new population of structures that seem to be pointing in the direction of the black hole," Yusef-Zadeh said. "I was actually stunned when I saw these. We had to do a lot of work to establish that we weren't fooling ourselves. And we found that these filaments are not random but appear to be tied to the outflow of our black hole. By studying them, we could learn more about the black hole's spin and accretion disk orientation. It is satisfying when one finds order in a middle of a chaotic field of the nucleus of our galaxy."

An expert in radio astronomy, Yusef-Zadeh is a professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences and member of CIERA.

Decades in the making

The new discovery may come as a surprise, but Yusef-Zadeh is no stranger to uncovering mysteries at the center of our galaxy, located 25,000 light-years from Earth. The latest study builds on four decades of his research. After first discovering the vertical filaments in 1984 with Mark Morris and Don Chance, Yusef-Zadeh along with Ian Heywood and their collaborators later uncovered two gigantic radio-emitting bubbles near Sagittarius A*. Then, in a series of publications in 2022, Yusef-Zadeh (in collaborations with Heywood, Richard Arent and Mark Wardle) revealed nearly 1,000 vertical filaments, which appeared in pairs and clusters, often stacked equally spaced or side by side like strings on a harp.

Yusef-Zadeh credits the flood of new discoveries to enhanced radio astronomy technology, particularly the South African Radio Astronomy Observatory's (SARAO) MeerKAT telescope. To pinpoint the filaments, Yusef-Zadeh's team used a technique to remove the background and smooth the noise from MeerKAT images in order to isolate the filaments from surrounding structures.

"The new MeerKAT observations have been a game changer," he said. "The advancement of technology and dedicated observing time have given us new information. It's really a technical achievement from radio astronomers."

Horizontal vs. vertical

After studying the vertical filaments for decades, Yusef-Zadeh was shocked to uncover their horizontal counterparts, which he estimates are about 6 million years old. "We have always been thinking about vertical filaments and their origin," he said. "I'm used to them being vertical. I never considered there might be others along the plane."

While both populations comprise one-dimensional filaments that can be viewed with radio waves and appear to be tied to activities in the galactic center, the similarities end there.

The vertical filaments are perpendicular to the galactic plane; the horizontal filaments are parallel to the plane but point radially toward the center of the galaxy where the black hole lies. The vertical filaments are magnetic and relativistic; the horizontal filaments appear to emit thermal radiation. The vertical filaments encompass particles moving at speeds near the speed of light; the horizontal filaments appear to accelerate thermal material in a molecular cloud. There are several hundred vertical filaments and just a few hundred horizontal filaments. And the vertical filaments, which measure up to 150 light-years high, far surpass the size of the horizontal filaments, which measure just 5 to 10 light-years in length. The vertical filaments also adorn space around the nucleus of the galaxy; the horizontal filaments appear to spread out to only one side, pointing toward the black hole.

"One of the most important implications of radial outflow that we have detected is the orientation of the accretion disk and the jet-driven outflow from Sagittarius A* along the galactic plane," Yusef-Zadeh said.

'Our work is never complete'

The new discovery is filled with unknowns, and Yusef-Zadeh's work to unravel its mysteries has just begun. For now, he can only consider a plausible explanation about the new population's mechanisms and origins.

"We think they must have originated with some kind of outflow from an activity that happened a few million years ago," Yusef-Zadeh said. "It seems to be the result of an interaction of that outflowing material with objects near it. Our work is never complete. We always need to make new observations and continually challenge our ideas and tighten up our analysis."

Read more at Science Daily

Genomes of 233 primate species sequenced

Researchers from 24 countries have analyzed the genomes of 809 individuals from 233 primate species, generating the most complete catalog of genomic information about our closest relatives to date. The project, which consists of a series of studies in which researchers from the German Primate Center -- Leibniz Institute for Primate Research (DPZ) were also involved, provides new insights into the evolution of primates, including humans, and their diversity. In baboons, for example, hybridization and gene flow between different species occurred in the past and is still ongoing in several regions of their range. This makes baboons a good model for the evolution of early human lineages within and outside Africa. In addition, using a specially designed AI algorithm, the genomic data enable new insights into the genetic causes of human diseases (Science, Special Issue).

Primates show great genetic diversity that varies between species and geographic regions. "Studying this diversity is crucial also for understanding human evolution, the causes of human diseases, and for preserving our closest relatives," says Christian Roos, a scientist in the Primate Genetics Laboratory at the German Primate Center and one of the authors. Led by researchers from Universitat Pompeu Fabra, Spain, Baylor College of Medicine, USA, and Illumina Inc, USA, the genomes of 809 individuals from 233 primate species have been sequenced. This covers nearly half of the extant primate species and increases the number of available primate genomes fourfold.

New insights into primate evolution and the uniqueness of humans

The comparative analyses provide fundamental information on the genetic diversity and evolutionary history of primates and important insights into what distinguishes humans from other primates. The genomic data have halved the number of genomic variants thought to occur exclusively in humans. "This makes it easier to look for mutations that we do not share with other primates and that could therefore be the basis for the traits that make us human," says Dietmar Zinner, a scientist in the Cognitive Ethology Laboratory at the German Primate Center and also one of the authors. One of the studies looks more closely at baboon evolution and finds that there have been several, previously unknown episodes of hybridization and gene flow between baboon species. "We found that baboons from western Tanzania are the first nonhuman primates to have received input from three genetic lineages," said Liye Zhang, a doctoral student at the German Primate Center and one of the lead authors of the baboon study. "These results suggest that the genetic structure of the baboon population and its history of genetic exchange between species is more complex than previously thought and show that baboons make a good model for similar processes in the evolution of early human lineages in and outside Africa," says Dietmar Zinner.

Species conservation with the help of genome data

High genetic diversity enables species to better adapt to changing environmental conditions and pathogens. Especially in small populations, there is a risk of inbreeding and thus a reduction in genetic diversity. Already, 63 percent of all primate species are threatened with extinction, and the analysis of genetic diversity provides information which species most urgently need to be protected, at least from a genetic point of view. "We found particularly low genetic diversity in the golden snub-nosed monkey of China and the aye-aye in Madagascar," says Christian Roos.

Read more at Science Daily

Jun 2, 2023

Astrophysicists confirm the faintest galaxy ever seen in the early universe

After the Big Bang, the universe expanded and cooled sufficiently for hydrogen atoms to form. In the absence of light from the first stars and galaxies, the universe entered a period known as the cosmic dark ages.

The first stars and galaxies appeared several hundred million years later and began burning away the hydrogen fog left over from the Big Bang, rendering the universe transparent, like it is today.

Researchers led by astrophysicists from UCLA confirmed the existence of a distant, faint galaxy typical of those whose light burned through the hydrogen atoms; the finding should help them understand how the cosmic dark ages ended.

An international research team led by UCLA astrophysicists has confirmed the existence of the faintest galaxy ever seen in the early universe. The galaxy, called JD1, is one of the most distant identified to date, and it is typical of the kinds of galaxies that burned through the fog of hydrogen atoms left over from the Big Bang, letting light shine through the universe and shaping it into what exists today.

The discovery was made using NASA's James Webb Space Telescope, and the findings are published in the journal Nature.

The first billion years of the universe's life were a crucial period in its evolution. After the Big Bang, approximately 13.8 billion years ago, the universe expanded and cooled sufficiently for hydrogen atoms to form. Hydrogen atoms absorb ultraviolet photons from young stars; however, until the birth of the first stars and galaxies, the universe became dark and entered a period known as the cosmic dark ages. The appearance of the first stars and galaxies a few hundred million years later bathed the universe in energetic ultraviolet light which began burning, or ionizing, the hydrogen fog. That, in turn, enabled photons to travel through space, rendering the universe transparent.

Determining the types of galaxies that dominated that era -- dubbed the Epoch of Reionization -- is a major goal in astronomy today, but until the development of the Webb telescope, scientists lacked the sensitive infrared instruments required to study the first generation of galaxies.

"Most of the galaxies found with JWST so far are bright galaxies that are rare and not thought to be particularly representative of the young galaxies that populated the early universe," said Guido Roberts-Borsani, a UCLA postdoctoral researcher and the study's first author. "As such, while important, they are not thought to be the main agents that burned through all of that hydrogen fog.

"Ultra-faint galaxies such as JD1, on the other hand, are far more numerous, which is why we believe they are more representative of the galaxies that conducted the reionization process, allowing ultraviolet light to travel unimpeded through space and time."

JD1 is so dim and so far away that it is challenging to study without a powerful telescope -- and a helping hand from nature. JD1 is located behind a large cluster of nearby galaxies, called Abell 2744, whose combined gravitational strength bends and amplifies the light from JD1, making it appear larger and 13 times brighter than it otherwise would. The effect, known as gravitational lensing, is similar to how a magnifying glass distorts and amplifies light within its field of view; without gravitational lensing, JD1 would likely have been missed.

The researchers used the Webb Telescope's near-infrared spectrograph instrument, NIRSpec, to obtain an infrared light spectrum of the galaxy, allowing them to determine its precise age and its distance from Earth, as well as the number of stars and amount of dust and heavy elements that it formed in its relatively short lifetime.

The combination of the galaxy's gravitational magnification and new images from another one of the Webb Telescope's near-infrared instruments, NIRCam, also made it possible for the team to study the galaxy's structure in unprecedented detail and resolution, revealing three main elongated clumps of dust and gas that are forming stars. The team used the new data to trace JD1's light back to its original source and shape, revealing a compact galaxy just a fraction of the size of older galaxies like the Milky Way, which is 13.6 billion years old.

Because light takes time to travel to Earth, JD1 is seen as it was approximately 13.3 billion years ago, when the universe was only about 4% of its present age.

Read more at Science Daily

Multiple species of semi-aquatic dinosaur may have roamed pre-historic Britain

Palaeontologists at the University of Southampton (UK) studying a British dinosaur tooth have concluded that several distinct groups of spinosaurs -- dinosaurs with fearsome crocodile-like skulls -- inhabited southern England over 100 million years ago.

The team, from the University's EvoPalaeoLab, carried out a series of tests on the 140 million year old tooth, discovered in the early 20th century, in a thick, complicated rock structure named the Wealden Supergroup. The Wealden lies across south-eastern England and was formed around 140-125 million years ago.

The scientists conducted statistical analysis on the tooth, which is stored at the Hastings Museum and Art Gallery in East Sussex. They meticulously compared its characteristics with other species in the spinosaur 'family' of dinosaurs to which it belongs. Their findings, published in the journal PeerJ, confirm the tooth doesn't match that of any identified spinosaur species.

Project supervisor, Dr Neil Gostling explains: "While we can't formally identify a new species from one tooth, we can say this spinosaur tooth doesn't match any of the existing species we know about. Given how many individual teeth exist in collections, this could be just the tip of the iceberg and it's quite possible that Britain may have once teemed with a diverse range of these semi-aquatic, fish-eating dinosaurs."

The Wealden is famous for its spinosaur fossils. Baryonyx -- discovered in Surrey in 1983 -- is one of the world's most significant spinosaur specimens, since it was the first to reveal the true appearance of this crocodile-headed group. Less impressive spinosaur remains -- isolated teeth -- are common throughout the Wealden, and have often been identified as belonging to Baryonyx. However, some experts have long suspected that this is incorrect.

"We used a variety of techniques to identify this specimen, in order to test whether isolated spinosaur teeth could be referred to Baryonyx," said lead author Chris Barker, whose PhD focuses on the spinosaurs of southern Britain. "The tooth did not group with Baryonyx in any of our data runs. It must belong to a different type of spinosaur."

The results show that distinct and distantly related spinosaur types lived in the region during Early Cretaceous times. This backs up research by the EvoPalaeoLab team, who argued in previous studies that the spinosaurs of southern England are more diverse than previously thought.

In 2021, they named the 'Hell Heron' Ceratosuchops from the Isle of Wight, and in 2022 announced the discovery of what might be Europe's largest ever land predator, a giant known only as the 'White Rock' spinosaur. These several spinosaurs did not all live at the same time, but inhabited the region over the course of more than 15 million years.

"Museums themselves are places to make exciting discoveries as our understanding of specimens changes from the time they were deposited," said Dr Neil Gostling. "What this work highlights is the importance of keeping collections alive, and developing our understanding of them. Curators are essential to help us navigate the cupboards and displays, helping us to unpick the often-incomplete records -- either never fully recorded, or lost to time. The diversity of palaeoenvironments is not always hidden in rocks, it is often waiting in a museum, its importance waiting to be rediscovered!"

Read more at Science Daily

Record 19.31% efficiency with organic solar cells

Researchers from The Hong Kong Polytechnic University (PolyU) have achieved a breakthrough power-conversion efficiency (PCE) of 19.31% with organic solar cells (OSCs), also known as polymer solar cells. This remarkable binary OSC efficiency will help enhance applications of these advanced solar energy devices.

The PCE (Power-conversion efficiency), a measure of the power generated from a given solar irradiation, is considered a significant benchmark for the performance of photovoltaics (PVs), or solar panels, in power generation. The improved efficiency of over 19% that was achieved by the PolyU researchers constitutes a record for binary OSCs, which have one donor and one acceptor in the photo-active layer.

Led by Prof. LI Gang, Chair Professor of Energy Conversion Technology and Sir Sze-Yen Chung Endowed Professor in Renewable Energy at PolyU, the research team invented a novel OSC morphology-regulating technique by using 1,3,5-trichlorobenzene as a crystallisation regulator. This new technique boosts OSC efficiency and stability.

The team developed a non-monotonic intermediated state manipulation (ISM) strategy to manipulate the bulk-heterojunction (BHJ) OSC morphology, which simultaneously optimises crystallisation dynamics and energy loss of non-fullerene OSCs. Unlike the strategy of using traditional solvent additives, which is based on excessive molecular aggregation in films, the ISM strategy promotes the formation of more ordered molecular stacking and favourable molecular aggregation. As a result, the PCE was considerably increased and the undesirable non-radiative recombination loss was reduced. Notably, non-radiative recombination lowers the light generation efficiency and increases the heat loss.

The research team's findings are described in the study "19.3% Binary Organic Solar Cell and Low Non-Radiative Recombination Enabled by Non-Monotonic Intermediate State Transition" published in Nature Communications . The conversion of solar energy to electricity is an essential technology for achieving a sustainable environment. Although OSCs are promising devices that harness solar energy cost-effectively, their efficiency must be improved if they are to be used widely in practical applications.

Non-fullerene acceptors based organic solar cells represent the frontier of research in the field of organic photovoltaics due to both the materials and morphology manipulation innovations. Nevertheless, non-radiative recombination loss suppress and performance boosting are in the centre of organic cell research.

Prof. Li said, "Challenges in research came from the existing additive-based benchmark morphology control methods, which suffer from non-radiative recombination loss, thus lowering the open-circuit voltage due to excessive aggregation." The research team took about two years to devise a non-monotonic ISM strategy for increasing the OSC efficiency and lowering the non-radiative recombination loss. The publication of the study promises to galvanise OSC research.

Prof. Li said, "The new finding will make OSC research an exciting field, and this will likely create tremendous opportunities in applications like portable electronics and building-integrated PVs." The new door will open when low cost single-junction OSCs can achieve a PCE of over 20%, along with more stable performance and other unique advantages such as flexibility, transparency, stretchability, low weight and tuneable colour.

Prof. Li has been recognised as a Highly Cited Researcher 9 years in a row since 2014, which testifies to his significant impact on global research. His pioneering contributions to research on polymer solar cells since 2005 have brought sustainable influence on printable solar energy development with global recognition.

Underpinning the research on OPV field, Prof LI's study titled, "High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends," was published on Nature Materials in 2005. This represented OPV's first generation research breakthrough which has fuelled solar technology from this frontier study.

In 2010, Prof LI's study titled "For the Bright Future -- Bulk Heterojunction Polymer Solar Cells with Power Conversion Efficiency of 7.4%" was published on Advanced Materials.

Prof. Li said, "The latest study shows a record low non-radiative recombination loss of 0.168 eV in a binary OSC with a PCE of over 19%. This is a very encouraging result for the long-standing research on OSCs that I have conducted over the past two decades. We have already achieved better OSC efficiency, and this will subsequently help accelerate the applications of solar energy."

Read more at Science Daily

Why do some people live to be 100? Intestinal bacteria may hold the answer

We are pursuing the dream of eternal life. We fast to stay healthy. And each year, we spend billions of kroner on treatment to make sure we stay alive. But some people turn 100 years old all by themselves. Why is that?

Researchers from the Novo Nordisk Foundation Center for Protein Research at the University of Copenhagen have set out to find the answer.

Studying 176 healthy Japanese centenarians, the researchers learned that the combination of intestinal bacteria and bacterial viruses of these people is quite unique.

"We are always eager to find out why some people live extremely long lives. Previous research has shown that the intestinal bacteria of old Japanese citizens produce brand new molecules that make them resistant to pathogenic -- that is, disease-promoting -- microorganisms. And if their intestines are better protected against infection, well, then that is probably one of the things that cause them to live longer than others," says Postdoc Joachim Johansen, who is first author of the new study.

Among other things, the new study shows that specific viruses in the intestines can have a beneficial effect on the intestinal flora and thus on our health.

"Our intestines contain billions of viruses living of and inside bacteria, and they could not care less about human cells; instead, they infect the bacterial cells. And seeing as there are hundreds of different types of bacteria in our intestines, there are also lots of bacterial viruses," says Associate Professor Simon Rasmussen, last author of the new study.

Joachim Johansen adds that aside from the important, new, protective bacterial viruses, the researchers also found that the intestinal flora of the Japanese centenarians is extremely interesting.

"We found great biological diversity in both bacteria and bacterial viruses in the centenarians. High microbial diversity is usually associated with a healthy gut microbiome. And we expect people with a healthy gut microbiome to be better protected against aging related diseases," says Joachim Johansen.

Once we know what the intestinal flora of centenarians looks like, we can get closer to understanding how we can increase the life expectancy of other people. Using an algorithm designed by the researchers, they managed to map the intestinal bacteria and bacterial viruses of the centenarians.

"We want to understand the dynamics of the intestinal flora. How do the different kinds of bacteria and viruses interact? How can we engineer a microbiome that can help us live healthy, long lives? Are some bacteria better than others? Using the algorithm, we are able to describe the balance between viruses and bacteria," says Simon Rasmussen.

And if the researchers are able to understand the connection between viruses and bacteria in the Japanese centenarians, they may be able to tell what the optimal balance of viruses and bacteria looks like.

Optimising intestinal bacteria

More specifically, the new knowledge on intestinal bacteria may help us understand how we should optimise the bacteria found in the human body to protect it against disease.

"We have learned that if a virus pays a bacterium a visit, it may actually strengthen the bacterium. The viruses we found in the healthy Japanese centenarians contained extra genes that could boost the bacteria. We learned that they were able to boost the transformation of specific molecules in the intestines, which might serve to stabilise the intestinal flora and counteract inflammation," says Joachim Johansen, and Simon Rasmussen adds:

"If you discover bacteria and viruses that have a positive effect on the human intestinal flora, the obvious next step is to find out whether only some or all of us have them. If we are able to get these bacteria and their viruses to move in with the people who do not have them, more people could benefit from them."

Even though this requires more research, the new insight is significant, because we are able to modify the intestinal flora.

Read more at Science Daily

Jun 1, 2023

NIRISS instrument on Webb maps an ultra-hot Jupiter's atmosphere

There's an intriguing exoplanet out there -- 400 light-years out there -- that is so tantalising that astronomers have been studying it since its discovery in 2009. One orbit for WASP-18 b around its star that is slightly larger than our Sun takes just 23 hours. There is nothing like it in our Solar System. A new study led by Université de Montréal Ph.D. student Louis-Philippe Coulombe about this exoplanet, an ultra-hot gas giant 10 times more massive than Jupiter, based on new data from the Canadian NIRISS instrument on the James Webb Space Telescope (JWST) holds many surprises!

Mapping an exoplanet

An international team of astronomers have identified water vapor in the atmosphere of the exoplanet WASP-18 b and made a temperature map of the planet as it slipped behind, and reappeared from, its star. This event is known as a secondary eclipse. Scientists can read the combined light from the star and planet, then refine the measurements from just the star as the planet moves behind it.

The same side, known as the dayside, of WASP-18 b always faces its star, just as the same side of the Moon always faces Earth. This is called tidal locking. The temperature, or brightness, map of the exoplanet shows a huge change in temperature -- up to 1,000 degrees -- from the hottest point facing the star to the terminator, where day and night sides of the tidally-locked planet meet in permanent twilight.

''JWST is giving us the sensitivity to make much more detailed maps of hot giant planets like WASP-18 b than ever before. This is the first time a planet has been mapped with JWST, and it's really exciting to see that some of what our models predicted, such as a sharp drop in temperature away from the point on the planet directly facing the star, is actually seen in the data!'' said Megan Mansfield, a Sagan Fellow at the University of Arizona, and one of the authors of the paper describing the results.

The team mapped temperature gradients across the day side of the planet. Given how much cooler the planet is at the terminator, there is likely something hindering winds from efficiently redistributing heat to the night side. But what is affecting the winds is still a mystery.

''The brightness map of WASP-18 b shows a lack of east-west winds that is best matched by models with atmospheric drag. One possible explanation is that this planet has a strong magnetic field, which would be an exciting discovery!'' said co-author Ryan Challener, of the University of Michigan.

One interpretation of the eclipse map is that magnetic effects force the winds to blow from the planet's equator up over the North pole and down over the South pole, instead of East-West, as we would otherwise expect.

Researchers recorded temperature changes at different elevations of the gas giant planet's layers of atmosphere. They saw temperatures increase with elevation, varying by hundreds of degrees.

Signs of water vapor

The spectrum of the planet's atmosphere clearly shows multiple small but precisely measured water features, present despite the extreme temperatures of almost 2,700 degrees Celsius. It is so hot that it would tear most water molecules apart, so still seeing its presence speaks to Webb's extraordinary sensitivity to detect remaining water. The amounts recorded in WASP-18 b's atmosphere indicate water vapor is present at various elevations

''It was a great feeling to look at WASP-18 b's JWST spectrum for the first time and see the subtle but precisely measured signature of water,'' said Louis-Philippe Coulombe, a Ph.D. student at the Université de Montréal, member of the Trottier Institute for Research on Exoplanets (iREx) and lead author of the WASP-18 b paper. ''Using this kind of measurements, we will be able to detect such molecules for a wide range of planets in the years to come!'', added Björn Benneke, UdeM Professor, iREx member and co-author of this paper. Benneke is Coulombe's Ph.D. advisor as well and has been leading worldwide efforts to study WASP-18 b since 2016.

The work of the NIRISS instrument and early career scientists

The team of astronomers observed WASP-18 b for about six hours using one of Webb's instruments, the Near-Infrared Imager and Slitless Spectrograph (NIRISS), contributed by the Canadian Space Agency and several partners including the Université de Montréal and iREx.

''Because the water features in this spectrum are so subtle, they were difficult to identify in previous observations. That made it really exciting to finally see water features with these JWST observations,'' said Anjali Piette, a postdoctoral fellow at the Carnegie Institution for Science and one of the authors of the new research.

The WASP-18 b observations were collected as part of the Transiting Exoplanet Community Early Release Science Program led by Natalie Batalha, an astronomer at the University of California, Santa Cruz, who helped coordinate the new research and the more than one hundred researchers in the team. Much of this ground-breaking work is being done by early career scientists like Coulombe, Challener, Piette, and Mansfield.

Proximity, both to its star and to us, helped make WASP-18 b such an intriguing target for these scientists, as did its large mass. WASP-18 b is one of the most massive worlds whose atmospheres we can investigate. Astronomers are striving to understand how such planets form and come to be where they are in their systems. This, too, has some early answers from Webb.

Read more at Science Daily

Ground beneath Thwaites Glacier mapped

The ground beneath Antarctica's most vulnerable glacier has been mapped for the first time, helping scientists to better understand how it is being affected by climate change. Analysis of the geology below the Thwaites Glacier in West Antarctica shows there is less sedimentary rock than expected -- a finding that could affect how the ice slides and melts in the coming decades.

"Sediments allow faster flow, like sliding on mud," says Dr Tom Jordan, a geophysicist with the British Antarctic Survey (BAS), who led the study. "Now we have a map of where the slippery sediments are, we can better predict how the glacier will behave in future as it retreats."

The distribution of sedimentary rocks beneath the Thwaites glacier is included in a new map of the geology of the region produced by the BAS researchers and published in the journal Science Advances. The findings are important because the glacier, which is the size of Great Britain or the US state of Florida, is one of the fastest changing ice-ocean systems in Antarctica.

The Thwaites glacier's grounding zone -- the point where it meets the seafloor -- has retreated 14 km since the late 1990s. Much of the ice sheet is below sea level and susceptible to rapid, irreversible ice loss that could raise global sea-level by over half a metre within centuries.

The new analysis is based on airborne surveys using aircraft equipped with radar which can see through the ice to the rocks below, as well as sensors which can map minute variations in gravity and magnetism hundreds to thousands of metres below the ground and seabed on which the glacier rests.

The researchers then use these multiple data sources to compile a 3D picture of features, including the type and extent of different rocks.

Jordan says: "The integrated nature of the airborne surveys was one of the keys to this research. Each sensor on the aircraft provided an important but incomplete part of the picture, but by bringing them all together we could provide the detailed map of the underlying geology."

In doing so, the study effectively turns back the geological clock to examine what happened when New Zealand was ripped away from Antarctica about 100 million years ago -- long before the Thwaites glacier was formed.

Because the base of Thwaites Glacier lies far below sea level, researchers had expected that thick sediments would have been deposited there over the subsequent millions of years Similar analysis has been done on some other Antarctic glaciers, showing that these other systems were predominantly underlain by thick sediments.

But the aircraft data suggests that only about a fifth of the ground below the glacier is sedimentary rock. These lie in a series of basins between 80 and 200 km long and about 30 km wide.

The rest is made up of other types of geological bodies, including granite peaks and other hard rocks. The scientists think that these sedimentary basins were once much larger, but they have been ground down to the bedrock by movement of the glacier.

It's not yet clear how this new knowledge of the subglacial geology will affect estimates of ice flow and loss from Thwaites and other glaciers. The study does show that the geological landscape has a direct control on the basal shear stress, which influences how fast ice can flow into the ocean. Members of the research team will now carry out more detailed studies of these processes. Modellers may also be able to use the new data to make more reliable projections of future ice loss.

Jordan says: "We hope that by showing the detailed geology, and how it correlates with the basal friction, future models of glacial retreat will have lower uncertainty, as the controls of the basal processes will be better understood."

He adds: "No single scientific study could ever match she scale and challenge of climate change. But it is the incremental building of all the individual scientific studies like this that allows us to understand and tackle that challenge."

Read more at Science Daily

Quarter-ton marsupial roamed long distances across Australia's arid interior

One of Australia's first long-distance walkers has been described after Flinders University palaeontologists used advanced 3D scans and other technology to take a new look at the partial remains of a 3.5 million year old marsupial from central Australia.

They have named a new genus of diprotodontid Ambulator, meaning walker or wanderer, because the locomotory adaptations of the legs and feet of this quarter-tonne animal would have made it well suited to roam long distances in search of food and water when compared to earlier relatives.

Researchers say the skeleton of Ambulator keanei, found on the Australian Wildlife Conservancy's Kalamurina Station in northern South Australia by Flinders University researchers in 2017, belongs to a species in the family Diprotodontidae, a group of four-legged herbivores that were the largest marsupials to ever exist.

"Diprotodontids are distantly related to wombats -- the same distance as kangaroos are to possums -- so unfortunately there is nothing quite like them today. As a result, palaeontologists have had a hard time reconstructing their biology," says Jacob van Zoelen, a PhD candidate at the Flinders University Palaeontology Laboratory.

The largest species, Diprotodon optatum, grew to the size of a car, weighing up to 2.7 tonnes. Diprotodontids were an integral part of Australian ecosystems until the last species became extinct about 40,000 years ago.

During the period when Ambulator keanei was alive (the Pliocene), there was an increase in grasslands and open habitat as Australia became drier. Diprotodontids likely had to travel much greater distances to obtain enough food and water to keep them going.

"We don't often think of walking as a special skill but when you're big any movement can be energetically costly so efficiency is key," says Mr van Zoelen.

"Most large herbivores today such as elephants and rhinoceroses are digitigrade, meaning they walk on the tips of their toes with their heel not touching the ground.

"Diprotodontids are what we call plantigrade, meaning their heel-bone (calcaneus) contacts the ground when they walk, similar to what humans do. This stance helps distribute weight when walking but uses more energy for other activities such as running."

Diprotodontids display extreme plantigrady in their hands as well, by modifying a bone of the wrist, the pisiform, into a secondary heel, Mr van Zoelen explains.

This 'heeled hand' made early reconstructions of these animals look bizarre and awkward, he says.

"Development of the wrist and ankle for weight-bearing meant that the digits became essentially functionless and likely did not make contact with the ground while walking. This may be why no finger or toe impressions are observed in the trackways of diprotodontids.

"So, diprotodontids such as Ambulator may have evolved this morphology to traverse great distances more efficiently. This morphology also allowed for greater weight to be supported, allowing diprotodontids to get very big indeed.

"Eventually, this led to the evolution of the giant and relatively well-known Diprotodon."

Most studies on the group have focused on the skull, as associated skeletons are rare in the fossil record. As such, the newly described skeleton is of great importance and is even more special as it is the first to be found with associated soft tissue structures.

Using 3D-scanning technology, the Flinders team was able to compare the partial skeleton with other diprotodontid material from collections all over the world.

Read more at Science Daily

First X-ray of a single atom

A team of scientists from Ohio University, Argonne National Laboratory, the University of Illinois-Chicago, and others, led by Ohio University Professor of Physics, and Argonne National Laboratory scientist, Saw Wai Hla, have taken the world's first X-ray SIGNAL (or SIGNATURE) of just one atom. This groundbreaking achievement was funded by the U.S. Department of Energy, Office of Basic Energy Sciences and could revolutionize the way scientists detect the materials.

Since its discovery by Roentgen in 1895, X-rays have been used everywhere, from medical examinations to security screenings in airports. Even Curiosity, NASA's Mars rover, is equipped with an X-ray device to examine the materials composition of the rocks in Mars. An important usage of X-rays in science is to identify the type of materials in a sample. Over the years, the quantity of materials in a sample required for X-ray detection has been greatly reduced thanks to the development of synchrotron X-rays sources and new instruments. To date, the smallest amount one can X-ray a sample is in attogram, that is about 10,000 atoms or more. This is due to the X-ray signal produced by an atom being extremely weak so that the conventional X-ray detectors cannot be used to detect it. According to Hla, it is a long-standing dream of scientists to X-ray just one atom, which is now being realized by the research team led by him.

"Atoms can be routinely imaged with scanning probe microscopes, but without X-rays one cannot tell what they are made of. We can now detect exactly the type of a particular atom, one atom-at-a-time, and can simultaneously measure its chemical state," explained Hla, who is also the director of the Nanoscale and Quantum Phenomena Institute at Ohio University. "Once we are able to do that, we can trace the materials down to ultimate limit of just one atom. This will have a great impact on environmental and medical sciences and maybe even find a cure that can have a huge impact for humankind. This discovery will transform the world."

Their paper, published in the scientific journal Nature on May 31, 2023, and gracing the cover of the print version of the scientific journal on June 1, 2023, details how Hla and several other physicists and chemists, including Ph.D. students at OHIO, used a purpose-built synchrotron X-ray instrument at the XTIP beamline of Advanced Photon Source and the Center for Nanoscale Materials at Argonne National Laboratory.

For demonstration, the team chose an iron atom and a terbium atom, both inserted in respective molecular hosts. To detect X-ray signal of one atom, the research team supplemented conventional detectors in X-rays with a specialized detector made of a sharp metal tip positioned at extreme proximity to the sample to collect X-ray excited electrons -- a technique known as synchrotron X-ray scanning tunneling microscopy or SX-STM. X-ray spectroscopy in SX-STM is triggered by photoabsorption of core level electrons, which constitutes elemental fingerprints and is effective in identifying the elemental type of the materials directly.

According to Hla, the spectrums are like fingerprints, each one being unique and able to detect exactly what it is.

"The technique used, and concept proven in this study, broke new ground in X-ray science and nanoscale studies," said Tolulope Michael Ajayi, who is the first author of the paper and doing this work as part of his Ph.D. thesis. "More so, using X-rays to detect and characterize individual atoms could revolutionize research and give birth to new technologies in areas such as quantum information and the detection of trace elements in environmental and medical research, to name a few. This achievement also opens the road for advanced materials science instrumentation."

For the last 12 years, Hla has been involved in the development of an SX-STM instrument and its measurement methods together with Volker Rose, a scientist at the Advanced Photon Source at Argonne National Laboratory.

"I have been able to successfully supervise four OHIO graduate students for their Ph.D. theses related to SX-STM method development over a 12-year period. We have come a long way to achieve the detection of a single atom X-ray signature," Hla said.

Hla's study is focused on nano and quantum sciences with a particular emphasis on understanding materials' chemical and physical properties at the fundamental level -- on an individual atom basis. In addition to achieving X-ray signature of one atom, the team's key goal was to use this technique to investigate the environmental effect on a single rare-earth atom.

"We have detected the chemical states of individual atoms as well," Hla explained. "By comparing the chemical states of an iron atom and a terbium atom inside respective molecular hosts, we find that the terbium atom, a rare-earth metal, is rather isolated and does not change its chemical state while the iron atom strongly interacts with its surrounding."

Many rare-earth materials are used in everyday devices, such as cell phones, computers and televisions, to name a few, and are extremely important in creating and advancing technology. Through this discovery, scientists can now identify not only the type of element but its chemical state as well, which will allow them to better manipulate the atoms inside different materials hosts to meet the ever-changing needs in various fields. Moreover, they have also developed a new method called "X-ray excited resonance tunneling or X-ERT" that allows them to detect how orbitals of a single molecule orient on a material surface using synchrotron X-rays.

"This achievement connects synchrotron X-rays with quantum tunneling process to detect X-ray signature of an individual atom and opens many exciting research directions including the research on quantum and spin (magnetic) properties of just one atom using synchrotron X-rays," Hla said.

Read more at Science Daily

May 31, 2023

One-third of galaxy's most common planets could be in habitable zone

Our familiar, warm, yellow sun is a relative rarity in the Milky Way. By far the most common stars are considerably smaller and cooler, sporting just half the mass of our sun at most. Billions of planets orbit these common dwarf stars in our galaxy.

To capture enough warmth to be habitable, these planets would need to huddle very close to their small stars, which leaves them susceptible to extreme tidal forces.

In a new analysis based on the latest telescope data, University of Florida astronomers have discovered that two-thirds of the planets around these ubiquitous small stars could be roasted by these tidal extremes, sterilizing them. But that leaves one-third of the planets -- hundreds of millions across the galaxy -- that could be in a goldilocks orbit close enough, and gentle enough, to hold onto liquid water and possibly harbor life.

UF astronomy professor Sarah Ballard and doctoral student Sheila Sagear published their findings the week of May 29 in the Proceedings of the National Academy of Sciences. Ballard and Sagear have long studied exoplanets, those worlds that orbit stars other than the sun.

"I think this result is really important for the next decade of exoplanet research, because eyes are shifting toward this population of stars," Sagear said. "These stars are excellent targets to look for small planets in an orbit where it's conceivable that water might be liquid and therefore the planet might be habitable."

Sagear and Ballard measured the eccentricity of a sample of more than 150 planets around these M dwarf stars, which are about the size of Jupiter. The more oval shaped an orbit, the more eccentric it is. If a planet orbits close enough to its star, at about the distance that Mercury orbits the sun, an eccentric orbit can subject it to a process known as tidal heating. As the planet is stretched and deformed by changing gravitational forces on its irregular orbit, friction heats it up. At the extreme end, this could bake the planet, removing all chance for liquid water.

"It's only for these small stars that the zone of habitability is close enough for these tidal forces to be relevant," Ballard said.

Data came from NASA's Kepler telescope, which captures information about exoplanets as they move in front of their host stars. To measure the planets' orbits, Ballard and Sagear focused especially on how long the planets took to move across the face of the stars. Their study also relied on new data from the Gaia telescope, which measured the distance to billions of stars in the galaxy.

"The distance is really the key piece of information we were missing before that allows us to do this analysis now," Sagear said.

Sagear and Ballard found that stars with multiple planets were the most likely to have the kind of circular orbits that allow them to retain liquid water. Stars with only one planet were the most likely to see tidal extremes that would sterilize the surface.

Read more at Science Daily

107-million-year-old pterosaur bones: Oldest in Australia

A team of researchers have confirmed that 107-million-year-old pterosaur bones discovered more than 30 years ago are the oldest of their kind ever found in Australia, providing a rare glimpse into the life of these powerful, flying reptiles that lived among the dinosaurs.

Published in the journal Historical Biology and completed in collaboration with Museums Victoria, the research analysed a partial pelvis bone and a small wing bone discovered by a team led by Museums Victoria Research Institute's Senior Curator of Vertebrate Palaeontology Dr Tom Rich and Professor Pat Vickers-Rich at Dinosaur Cove in Victoria, Australia in the late 1980s.

The team found the bones belonged to two different pterosaur individuals. The partial pelvis bone belonged to a pterosaur with a wingspan exceeding two metres, and the small wing bone belonged to a juvenile pterosaur -- the first ever reported in Australia.

Lead researcher and PhD student Adele Pentland, from Curtin's School of Earth and Planetary Sciences, said pterosaurs -- which were close cousins of the dinosaurs -- were winged reptiles that soared through the skies during the Mesozoic Era.

"During the Cretaceous Period (145-66 million years ago), Australia was further south than it is today, and the state of Victoria was within the polar circle -- covered in darkness for weeks on end during the winter. Despite these seasonally harsh conditions, it is clear that pterosaurs found a way to survive and thrive," Ms Pentland said.

"Pterosaurs are rare worldwide, and only a few remains have been discovered at what were high palaeolatitude locations, such as Victoria, so these bones give us a better idea as to where pterosaurs lived and how big they were.

"By analysing these bones, we have also been able to confirm the existence of the first ever Australian juvenile pterosaur, which resided in the Victorian forests around 107 million years ago."

Ms Pentland said that although the bones provide important insights about pterosaurs, little is known about whether they bred in these harsh polar conditions.

"It will only be a matter of time until we are able to determine whether pterosaurs migrated north during the harsh winters to breed, or whether they adapted to polar conditions. Finding the answer to this question will help researchers better understand these mysterious flying reptiles," Ms Pentland said.

Dr Tom Rich, from Museums Victoria Research Institute, said it was wonderful to see the fruits of research coming out of the hard work of Dinosaur Cove which was completed decades ago.

"These two fossils were the outcome of a labour-intensive effort by more than 100 volunteers over a decade," Dr Rich said.

"That effort involved excavating more than 60 metres of tunnel where the two fossils were found in a seaside cliff at Dinosaur Cove."

Read more at Science Daily

New catalyst lowers cost for producing environmentally sustainable hydrogen from water

A plentiful supply of clean energy is lurking in plain sight. It is the hydrogen we can extract from water (H2O) using renewable energy. Scientists are seeking low-cost methods for producing clean hydrogen from water to replace fossil fuels, as part of the quest to combat climate change.

Hydrogen can power vehicles while emitting nothing but water. Hydrogen is also an important chemical for many industrial processes, most notably in steel making and ammonia production. Using cleaner hydrogen is highly desirable in those industries.

A multi-institutional team led by the U.S. Department of Energy's (DOE) Argonne National Laboratory has developed a low-cost catalyst for a process that yields clean hydrogen from water. Other contributors include DOE's Sandia National Laboratories and Lawrence Berkeley National Laboratory, as well as Giner Inc.

"A process called electrolysis produces hydrogen and oxygen from water and has been around for more than a century," said Di-Jia Liu, senior chemist at Argonne. He also holds a joint appointment in the Pritzker School of Molecular Engineering at the University of Chicago.

Proton exchange membrane (PEM) electrolyzers represent a new generation of technology for this process. They can split water into hydrogen and oxygen with higher efficiency at near room temperature. The reduced energy demand makes them an ideal choice for producing clean hydrogen by using renewable but intermittent sources, such as solar and wind.

This electrolyzer runs with separate catalysts for each of its electrodes (cathode and anode). The cathode catalyst yields hydrogen, while the anode catalyst forms oxygen. A problem is that the anode catalyst uses iridium, which has a current market price of around $5,000 per ounce. The lack of supply and high cost of iridium pose a major barrier for widespread adoption of PEM electrolyzers.

The main ingredient in the new catalyst is cobalt, which is substantially cheaper than iridium. "We sought to develop a low-cost anode catalyst in a PEM electrolyzer that generates hydrogen at high throughput while consuming minimal energy," Liu said. "By using the cobalt-based catalyst prepared by our method, one could remove the main bottleneck of cost to producing clean hydrogen in an electrolyzer."

Giner Inc., a leading research and development company working toward commercialization of electrolyzers and fuel cells, evaluated the new catalyst using its PEM electrolyzer test stations under industrial operating conditions. The performance and durability far exceeded that of competitors' catalysts.

Important to further advancing the catalyst performance is understanding the reaction mechanism at the atomic scale under electrolyzer operating conditions. The team deciphered critical structural changes that occur in the catalyst under operating conditions by using X-ray analyses at the Advanced Photon Source (APS) at Argonne. They also identified key catalyst features using electron microscopy at Sandia Labs and at Argonne's Center for Nanoscale Materials (CNM). The APS and CNM are both DOE Office of Science user facilities.

"We imaged the atomic structure on the surface of the new catalyst at various stages of preparation," said Jianguo Wen, an Argonne materials scientist.

In addition, computational modeling at Berkeley Lab revealed important insights into the catalyst's durability under reaction conditions.

The team's achievement is a step forward in DOE's Hydrogen Energy Earthshot initiative, which mimics the U.S. space program's "Moon Shot" of the 1960s. Its ambitious goal is to lower the cost for green hydrogen production to one dollar per kilogram in a decade. Production of green hydrogen at that cost could reshape the nation's economy. Applications include the electric grid, manufacturing, transportation and residential and commercial heating.

"More generally, our results establish a promising path forward in replacing catalysts made from expensive precious metals with elements that are much less expensive and more abundant," Liu noted.

Read more at Science Daily

Plants can distinguish when touch starts and stops, study suggests

Even without nerves, plants can sense when something touches them and when it lets go, a Washington State University-led study has found.

In a set of experiments, individual plant cells responded to the touch of a very fine glass rod by sending slow waves of calcium signals to other plant cells, and when that pressure was released, they sent much more rapid waves. While scientists have known that plants can respond to touch, this study shows that plant cells send different signals when touch is initiated and ended.

"It is quite surprising how finely sensitive plants cells are -- that they can discriminate when something is touching them. They sense the pressure, and when it is released, they sense the drop in pressure," said Michael Knoblauch, WSU biological sciences professor and senior author of the study in the journal Nature Plants. "It's surprising that plants can do this in a very different way than animals, without nerve cells and at a really fine level."

Knoblauch and his colleagues conducted a set of 84 experiments on 12 plants using thale cress and tobacco plants that had been specially bred to include calcium sensors, a relatively new technology. After placing pieces of these plants under a microscope, they applied a slight touch to individual plant cells with a micro-cantilever, essentially a tiny glass rod about the size of a human hair. They saw many complex responses depending on the force and duration of the touch, but the difference between the touch and its removal was clear.

Within 30 seconds of the applied touch to a cell, the researchers saw slow waves of calcium ions, called cytosolic calcium, travelling from that cell through the adjacent plant cells, lasting about three to five minutes. Removal of the touch showed an almost instant set of more rapid waves that dissipated within a minute.

The authors believe these waves are likely due to the change in pressure inside the cell. Unlike animal cells with permeable membranes, plant cells also have strong cellular walls that cannot be easily breached, so just a light touch will temporarily increase pressure in a plant cell.

The researchers tested the pressure theory mechanically by inserting a tiny glass capillary pressure probe into a plant cell. Increasing and decreasing pressure inside the cell resulted in similar calcium waves elicited by the start and stop of a touch.

"Humans and animals sense touch through sensory cells. The mechanism in plants appears to be via this increase or decrease of the internal cell pressure," said Knoblauch. "And it doesn't matter which cell it is. We humans may need nerve cells, but in plants, any cell on the surface can do this."

Previous research has shown that when a pest like a caterpillar bites a plant leaf, it can initiate the plant's defensive responses such as the release of chemicals that make leaves less tasty or even toxic to the pest. An earlier study also revealed that brushing a plant triggers calcium waves that activate different genes.

The current study was able to differentiate the calcium waves between touch and letting go, but how exactly the plant's genes respond to those signals remains to be seen. With new technologies like the calcium sensors used in this study, scientists can start to untangle that mystery, Knoblauch said.

"In future studies, we have to trigger the signal in a different way than has been done before to know what signal, if touch or letting go, triggers downstream events," he said.

Read more at Science Daily

May 30, 2023

Astronomers discover last three planets Kepler telescope observed before going dark

More than 5,000 planets are confirmed to exist beyond our solar system. Over half were discovered by NASA's Kepler Space Telescope, a resilient observatory that far outlasted its original planned mission. Over nine and a half years, the spacecraft trailed the Earth, scanning the skies for periodic dips in starlight that could signal the presence of a planet crossing in front of its star.

In its last days, the telescope kept recording the brightness of stars as it was running out of fuel. On Oct. 30, 2018, its fuel tanks depleted, the spacecraft was officially retired.

Now, astronomers at MIT and the University of Wisconsin at Madison, with the help of citizen scientists, have discovered what may be the last planets that Kepler gazed upon before going dark.

The team combed through the telescope's last week of high-quality data and spotted three stars, in the same part of the sky, that appeared to dim briefly. The scientists determined that two of the stars each host a planet, while the third hosts a planet "candidate" that has yet to be verified.

The two validated planets are K2-416 b, a planet that is about 2.6 times the size of the Earth and that orbits its star about every 13 days, and K2-417 b, a slightly larger planet that is just over three times Earth's size and that circles its star every 6.5 days. For their size and proximity to their stars, both planets are considered "hot mini-Neptunes ." They are located about 400 light years from Earth.

The planet candidate is EPIC 246251988 b -- the largest of the three worlds at almost four times the size of the Earth. This Neptune-sized candidate orbits its star in around 10 days, and is slightly farther away, 1,200 light years from Earth.

"We have found what are probably the last planets ever discovered by Kepler, in data taken while the spacecraft was literally running on fumes," says Andrew Vanderburg, assistant professor of physics in MIT's Kavli Institute for Astrophysics and Space Research. "The planets themselves are not particularly unusual, but their atypical discovery and historical importance makes them interesting."

The team has published their discovery today in the journal Monthly Notices of the Royal Astronomical Society. Vanderburg's co-authors are lead author Elyse Incha, at the University of Wisconsin at Madison, and amateur astronomers Tom Jacobs and Daryll LaCourse, along with scientists at NASA, the Center for Astrophysics of Harvard and the Smithsonian, and the University of North Carolina at Chapel Hill.

Data squeeze


In 2009, NASA launched the Kepler telescope into space, where it followed the Earth's orbit and continuously monitored millions of stars in a patch of the northern sky. Over four years, the telescope recorded the brightness of over 150,000 stars, which astronomers used to discover thousands of possible planets beyond our solar system.

Kepler kept observing beyond its original three-and-a-half-year mission, until May 2013, when the second of four reaction wheels failed. The wheels served as the spacecraft's gyroscopes, helping to keep the telescope pointed at a particular point in the sky. Kepler's observations were put on pause while scientists searched for a fix.

One year later, Kepler restarted as "K2," a reworked mission that used the sun's wind to balance the unsteady spacecraftin a way that kept the telescope relatively stable for a few months at a time -- a period called a campaign. K2 went on for another four years, observing over half a million more stars before the spacecraft finally ran out of fuel during its 19th campaign. The data from this last campaign comprised only a week of high-quality observations and another 10 days of noisier measurements as the spacecraft rapidly lost fuel.

"We were curious to see whether we could get anything useful out of this short dataset," Vanderburg says. "We tried to see what last information we could squeeze out of it."

By eye

Vanderburg and Incha presented the challenge to the Visual Survey Group, a team of amateur and professional astronomers who hunt for exoplanets in satellite data. They search by eye through thousands of recorded light curves of each star, looking for characteristic dips in brightness that signal a "transit," or the possible crossing of a planet in front of its star.

The citizen scientists are especially suited to combing through short datasets such as K2's very last campaign.

"They can distinguish transits from other wacky things like a glitch in the instrument," Vanderburg says. "That's helpful especially when your data quality begins to suffer, like it did in K2's last bit of data."

The astronomers spent a few days efficiently looking through the light curves that Kepler recorded from about 33,000 stars. The team worked with only a week's worth of high-quality data from the telescope before it began to lose fuel and focus. Even in this short window of data, the team was able to spot a single transit in three different stars.

Incha and Vanderburg then looked at the telescope's very last, lower-quality observations, taken in its last 11 days of operation, to see if they could spot any additional transits in the same three stars -- evidence that a planet was periodically circling its star.

During this 11-day period, as the spacecraft was losing fuel, its thrusters fired more erratically, causing the telescope's view to drift. In their analysis, the team focused on the region of each star's light curves between thruster activity, to see if they could spot any additional transits in these less data-noisy moments.

This search revealed a second transit for K2-416 b and K2-417 b, validating that they each host a planet. The team also detected a similar dip in brightness for K2-417 b in data taken of the same star by NASA's Transiting Exoplanet Survey Satellite (TESS), a mission that is led and operated by MIT. Data from TESS helped to confirm the planet candidate around this star.

"Those two are pretty much, without a doubt, planets," Incha says. "We also followed up with ground-based observations to rule out all kinds of false positive scenarios for them, including background star interference, and close-in stellar binaries."

"These are the last chronologically observed planets by Kepler, but every bit of the telescope's data is incredibly useful," Incha says. "We want to make sure none of that data goes to waste, because there are still a lot of discoveries to be made."

Read more at Science Daily

Early toilets reveal dysentery in Old Testament Jerusalem

A new analysis of ancient faeces taken from two Jerusalem latrines dating back to the biblical Kingdom of Judah has uncovered traces of a single-celled microorganism Giardia duodenalis -- a common cause of debilitating diarrhoea in humans.

A research team led by the University of Cambridge say it is the oldest example we have of this diarrhoea-causing parasite infecting humans anywhere on the planet. The study is published in the journal Parasitology.

"The fact that these parasites were present in sediment from two Iron Age Jerusalem cesspits suggests that dysentery was endemic in the Kingdom of Judah," said study lead author Dr Piers Mitchell from Cambridge's Department of Archaeology.

"Dysentery is a term that describes intestinal infectious diseases caused by parasites and bacteria that trigger diarrhoea, abdominal cramps, fever and dehydration. It can be fatal, particularly for young children."

"Dysentery is spread by faeces contaminating drinking water or food, and we suspected it could have been a big problem in early cities of the ancient Near East due to over-crowding, heat and flies, and limited water available in the summer," said Mitchell.

The faecal samples came from the sediment underneath toilets found in two building complexes excavated to the south of the Old City, which date back to the 7th century BCE when Jerusalem was a capital of Judah.

During this time, Judah was a vassal state under the control of the Assyrian Empire, which at its height stretched from the Levant to the Persian Gulf, incorporating much of modern-day Iran and Iraq. Jerusalem would have been a flourishing political and religious hub estimated to have had between 8,000 and 25,000 residents.

Both toilets had carved stone seats almost identical in design: a shallow curved surface for sitting, with a large central hole for defecation and an adjacent hole at the front for male urination. "Toilets with cesspits from this time are relatively rare and were usually made only for the elite," said Mitchell.

One was from a lavishly decorated estate at Armon ha-Natziv, surrounded by an ornamental garden. The site, excavated in 2019, probably dates from the days of King Manasseh, a client king for the Assyrians who ruled for fifty years in the mid-7th century.

The site of the other toilet, known as the House of Ahiel, was a domestic building made up of seven rooms, housing an upper-class family at the time. Date of construction is hard to pin down, with some placing it around the 8th century BCE.

However, its destruction is safely dated to 586 BCE, when Babylonian ruler Nebuchadnezzar II brutally sacked Jerusalem for a second time after its citizens refused to pay their agreed tribute, bringing to an end the Kingdom of Judah.

Ancient medical texts from Mesopotamia during the first and second millennium BCE describe diarrhoea affecting the populations of what is now the Near and Middle East. One example reads: "If a person eats bread and drinks beer and subsequently his stomach is colicky, he has cramps and has a flowing of the bowels, setu has gotten him."

The cuneiform word often used in these texts to describe diarrhoea was sà si-sá. Some texts also included recommended incantations for reciting to increase the chances of recovery.

"These early written sources do not provide causes of diarrhoea, but they encourage us to apply modern techniques to investigate which pathogens might have been involved," said Mitchell. "We know for sure that Giardia was one of those infections responsible."

The team investigated the two-and-a-half-thousand year-old decomposed biblical period faeces by applying a bio-molecular technique called "ELISA," in which antibodies bind onto the proteins uniquely produced by particular species of single-celled organisms.

"Unlike the eggs of other intestinal parasites, the protozoa that cause dysentery are fragile and extremely hard to detect in ancient samples through microscopes without using antibodies," said co-author and Cambridge PhD candidate Tianyi Wang.

The researchers tested for Entamoeba, Giardia and Cryptosporidium: three parasitic microorganisms that are among the most common causes of diarrhoea in humans, and behind outbreaks of dysentery. Tests for Entamoeba and Cryptosporidium were negative, but those for Giardia were repeatedly positive.

Previous research has dated traces of the Entamoeba parasite, which also causes dysentery, as far back as Neolithic Greece over 4,000 years ago. Previous work has also shown that users of ancient Judean toilets were infected by other intestinal parasites including whipworm, tapeworm and pinworm.

Read more at Science Daily

4,000-year-old plague DNA found -- the oldest cases to date in Britain

Researchers at the Francis Crick Institute have identified three 4,000-year-old British cases of Yersinia pestis, the bacteria causing the plague -- the oldest evidence of the plague in Britain to date, reported in a paper published today in Nature Communications.

Working with the University of Oxford, the Levens Local History Group and the Wells and Mendip Museum, the team identified two cases of Yersinia pestis in human remains found in a mass burial in Charterhouse Warren in Somerset and one in a ring cairn monument in Levens in Cumbria.

They took small skeletal samples from 34 individuals across the two sites, screening for the presence of Yersinia pestis in teeth. This technique is performed in a specialist clean room facility where they drill into the tooth and extract dental pulp, which can trap DNA remnants of infectious diseases.

They then analysed the DNA and identified three cases of Yersinia pestis in two children estimated to be aged between 10-12 years old when they died, and one woman aged between 35-45. Radiocarbon dating was used to show it's likely the three people lived at roughly the same time.

The plague has previously been identified in several individuals from Eurasia between 5,000 and 2,500 years before present (BP), a period spanning the Late Neolithic and Bronze Age (termed LNBA), but hadn't been seen before in Britain at this point in time. The wide geographic spread suggests that this strain of the plague may have been easily transmitted.

This strain of the plague -- the LNBA lineage -- was likely brought into Central and Western Europe around 4,800 BP by humans expanding into Eurasia, and now this research suggests that it extended to Britain.

Using genome sequencing, the researchers showed that this strain of the Yersinia pestis looks very similar to the strain identified in Eurasia at the same time.

The individuals identified all lacked the yapC and ymt genes, which are seen in later strains of plague, the latter of which is known to play an important role in plague transmission via fleas. This information has previously suggested that this strain of the plague was not transmitted via fleas, unlike later plague strains such as the one that caused the Black Death.

Because pathogenic DNA -- DNA from bacteria, protozoa, or viruses which cause disease -- degrades very quickly in samples which might be incomplete or eroded, it's also possible that other individuals at these burial sites may have been infected with the same strain of plague.

The Charterhouse Warren site is rare as it doesn't match other funeral sites from the time period -- the individuals buried there appear to have died from trauma. The researchers speculate that the mass burial wasn't due to an outbreak of plague but individuals may have been infected at the time they died.

Pooja Swali, first author and PhD student at the Crick, said, "The ability to detect ancient pathogens from degraded samples, from thousands of years ago, is incredible. These genomes can inform us of the spread and evolutionary changes of pathogens in the past, and hopefully help us understand which genes may be important in the spread of infectious diseases. We see that this Yersinia pestis lineage, including genomes from this study, loses genes over time, a pattern that has emerged with later epidemics caused by the same pathogen."

Pontus Skoglund, group leader of the Ancient Genomics Laboratory at the Crick, said, "This research is a new piece of the puzzle in our understanding of the ancient genomic record of pathogens and humans, and how we co-evolved.

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Groundbreaking images of root chemicals offer new insights on plant growth

On a sunny springtime stroll through a park, it's easy to ignore the parts of plants that are hidden from view. Plant biologists see things differently. They look below the surface where plant roots are organized in elaborate systems that are critical to the organism's development. Intricately organized tree root systems, for example, can span as far underground as the tree grows high above the soil.

Applying an advanced imaging technology to plant roots, researchers at the University of California San Diego and Stanford University have developed a new understanding of essential root chemicals that are responsible for plant growth. Using a type of mass spectrometer, a study led by UC San Diego Biological Sciences Postdoctoral Scholar Tao Zhang and Assistant Professor Alexandra Dickinson produced a "roadmap" that profiles where key small molecules are distributed along stem cells of maize (corn) plant roots and how their placement factors into the plant's maturation. The findings were published in the journal Nature Communications.

"This chemical roadmap provides a resource that scientists can use to find new ways of regulating plant growth," said Dickinson, a faculty member in the Department of Cell and Developmental Biology. "Having more information about how roots grow could be useful in conservation as we think about protecting our plants in natural environments and making them more sustainable, especially in agriculture."

While working as a visiting scientist at Stanford University, Dickinson began collaborating with study co-first author Sarah Noll and Professor Richard Zare, who developed a mass spectrometry imaging system that helps surgeons distinguish between cancerous and benign tissue during tumor-removal operations.

Dickinson, Zare and Noll adapted the technology -- called "desorption electrospray ionization mass spectrometry imaging" or DESI-MSI -- to probe plant roots for the chemicals involved in growth and energy production. They initially focused on maize plants at the root tips, where stem cells play an active role in the plant's development. Their method involved cutting through the center of the root to get a clear image of the chemicals inside.

"To help understand plant roots from the biology side, we needed to find out which chemicals are there," said Zare. "Our imaging system sprays out droplets that strike different portions of the root and dissolve chemicals at that location. A mass spectrometer collects the droplet splash and tells us what those dissolved chemicals are. By systematically scanning the droplet target spot we make a spatial map of the root chemicals."

The resulting images, believed to be some of the first to reveal the transition between stem cells and mature root tissue, show the foundational role of metabolites -- molecules involved in the plant's energy production. Tricarboxylic acid (TCA) cycle metabolites became the focus of the research since they were found to be a key player in controlling root development.

Coming into the study, the researchers expected a relatively uniform distribution of chemicals. Instead, with their chemical roadmap in hand, they found that TCA metabolites are clustered in patches across the root.

"I was surprised by how many chemicals are featured in really distinct patterns," said Dickinson. "We can see that the plant is doing this on purpose -- it needs these molecules in specific regions to grow properly." The Dickinson lab showed that these TCA metabolites have predictable effects in development, not only in maize, but in another plant species as well (Arabidopsis). This is likely because TCA metabolites are highly conserved -- they are made in all plants as well as animals.

Also emerging from the new images were previously unidentified chemical compounds. Dickinson says the mystery compounds could be critical for plant growth since they also are grouped in patterns at specific locations, suggesting a prominent role in development. Dickinson and her colleagues are now investigating these compounds and comparing varieties of maize that have different levels of stress resistance for adverse threats such as severe climate conditions and drought. The new information will help them develop novel chemical and genetic strategies for improving plant growth and stress resilience.

"We're looking at different maize plants that have drought resistance to see if we've already found chemicals that are specific to that variety that we haven't seen in other varieties," said Dickinson. "We think that could be a way to find new compounds that can promote growth, especially in harsh conditions."

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May 29, 2023

The search for habitable planets expands

A University of Michigan astronomer and his team are suggesting a new way to expand the search for habitable planets that takes into account a zone not previously considered: the space between the star and what's called soot-line in planet-forming disks.

Worlds that form in this region -- a disk of dust rotating around a central star from which planets may be built -- could have surfaces rich in volatile carbon compounds quite different from Earth's. These planets would also be rich in organic carbon, but water poor, according toTed Bergin, who led the study that included geochemists, planetary scientists, astrochemists and exoplanet experts.

When we search for Earth-like planets, we are particularly interested not only in bodies that look like ours, but also in those that are formed by processes similar to ours. Current models of rocky exoplanets are built using Earth-like atmospheric conditions and bulk composition, including the molecules essential for life that form from carbon-based building blocks and water. These models also focus on zones within planet-forming disks called ice lines, regions distant enough from the disk's center star which mark where water or other key molecules transition from gas to solid phases.

Terrestrial worlds, like our planet, formed from solids. It has long been thought that Earth, which contains only approximately 0.1% water by mass, must have formed inside the water-ice line.

But that type of model may be too limited, Bergin said. To expand the search for habitable planets, Bergin and his research team suggest a new model that considers the soot line, a boundary closer to the solar system's star. Between this boundary and the star, organic compounds in solids sublimate out of the solid into gas. Considering this region would also encompass rocky planets that may have more carbon than Earth has, raising questions about what that means for habitability in these kinds of planets.

The findings by the interdisciplinary research team are published in Astrophysical Journal Letters.

"It adds a new dimension in our search for habitability. It may be a negative dimension or it may be a positive dimension," Bergin said. "It's exciting because it leads to all kinds of endless possibilities."

Just as Earth is poor in water, it is carbon poor as well, Bergin said. When forming, it likely received only 1 carbon atom per 100 available in planet-forming materials. Astronomers think the soot line explains why Earth has so little carbon. If Earth's building blocks formed inside the soot line, the temperature and solar radiation blasted the materials that would form the young planet, turning carbon-rich compounds into gas and limiting carbon in the solids that are supplied to the forming Earth.

The team's model theorizes about the formation of other planets born in between the soot line and water-ice lines.

Such a world does not appear to exist in our solar system, but our solar system is not representative of most known planetary systems around other stars, Bergin said. These other planetary systems look completely different. Their planets are closer to the sun and are much larger, ranging in size from what are called super-Earths to mini-Neptunes, he said.

"These are either big rocks or small gas giants -- that's the most common type of planetary system. So maybe, within all those other solar systems out in the Milky Way galaxy, there exists a population of bodies that we haven't recognized before that have much more carbon in their interiors. What are the consequences of that?" Bergin said. "What this means for habitability needs to be explored."

In their study, the team models what happens when a silicate-rich world with 0.1% and 1% carbon by mass and a variable water content forms in the soot line region. They found that such a planet would develop a methane-rich atmosphere through a process called outgassing. In this circumstance, organic compounds in a silicate-rich planet produce a methane-rich atmosphere.

The presence of methane provides a fertile environment for the generation of hazes through interactions with stellar photons. This is analogous to the generation of hazes from methane in Titan in our own solar system.

"Planets that are born within this region, which exists in every planet-forming disk system, will release more volatile carbon from their mantles," Bergin said. "This could readily lead to the natural production of hazes. Such hazes have been observed in the atmospheres of exoplanets and have the potential to change the calculus for what we consider habitable worlds."

Haze around a planet might be a signpost that the planet has volatile carbon in its mantle. And more carbon, the backbone of life, in the mantle of a planet means that the planet has a chance to be considered habitable -- or at least deserves a second glance, Bergin said.

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Where do our limbs come from?

An international collaboration that includes scientists from the University of Colorado School of Medicine has uncovered new clues about the origin of paired appendages -- a major evolutionary step that remains unresolved and highly debated.

The researchers describe their study in an article published today in the journal Nature.

"This has become a topic that comes with bit of controversy, but it's really a very fundamental question in evolutionary biology: Where do our limbs come from?" says co-corresponding author Christian Mosimann, PhD, associate professor and Johnson Chair in the Department of Pediatrics, Section of Developmental Biology at CU School of Medicine.

That question -- where do our limbs come from? -- has been subject of debate for more than 100 years. In 1878, German scientist Carl Gegenbaur proposed that paired fins derived from a source called the gill arch, which are bony loops present in fish to support their gills. Other scientists favor the lateral fin fold hypothesis, concluding that lateral fins on the top and bottom of the fish are the source of paired fins.

"It is a highly active research topic because it's been an intellectual challenge for such a long time," Mosimann says. "Many big labs have studied the various aspects of how our limbs develop and have evolved." Among those labs are Dr. Mosimann's colleagues and co-authors, Tom Carney, PhD, and his team at the Lee Kong Chian School of Medicine at Nanyang Technological University in Singapore.

Chasing the odd cells

For Mosimann, the inquiry into where limbs come from is an offshoot of other research conducted by his laboratory on the CU Anschutz Medical Campus. In his laboratory, his team uses zebrafish as a model to understand the development from cells to organs. He and his team study how cells decide their fate, looking for explanations for how development can go awry leading to congenital anomalies, in particular cardiovascular and connective tissue diseases.

Along the way, Mosimann and his lab team observed how a peculiar cell type with features of connective tissue cells, so-called fibroblasts that share a developmental origin with the cardiovascular system, migrated into specific developing fins of the zebrafish. It turns out that these cells may support a connection between the competing theories of paired appendage evolution.

"We always knew these cells were odd," he says. "There were these fibroblast-looking cells that went into the so-called ventral fin, the fin at the belly of the developing zebrafish. Similar fibroblast cells didn't crawl into any other fin except the pectoral fin, which are the equivalent of our arms. So we kept noticing these peculiar fibroblasts, and we could never make sense of what these were for many years."

The Mosimann lab has developed several techniques to track cell fates during development in pursuit of their main topic, which is an improved understanding of how the embryonic cell layer, called the lateral plate mesoderm, contributes to diverse organs. The lateral plate mesoderm is the developmental origin of the heart, blood vessels, kidneys, connective tissue, as well as major parts of limbs.

The paired fins that form the equivalent of our arms and legs are seeded by cells from the lateral plate mesoderm, while other fins are not. Understanding how these particular fins became more limb-like has been at the core of a long-standing debate.

Developing new theories

Hannah Moran, who is pursuing her PhD in the Cell Biology, Stem Cells and Development program in the Mosimann lab, adapted a method of tracking lateral plate mesoderm cells that contribute to heart development so that researchers could track the peculiar fibroblasts related to limb development.

"My primary research project focuses on the development of the heart rather than limb development," Moran says, "but there was a genetic technique that I had adapted to map early heart cells, and so we were able to implement that into mapping where the mysterious cells of the ventral fin came from. And turns out, they are also from the lateral plate mesoderm."

This crucial discovery provides a new puzzle piece to the big picture of how we evolved our arms and legs. Increasing evidence supports a hypothesis of paired appendage evolution called the dual origin theory.

"Our data fit nicely into this combined theory, but it can also stand on its own with the lateral fin theory," says Robert Lalonde, PhD, postdoctoral fellow in the Mosimann lab. "While paired appendages arise from the lateral plate mesoderm, that does not rule out an ancient connection to unpaired, lateral fins."

By observing the mechanisms of embryonic development and comparing the anatomy of existing species, research groups like Mosimann's can develop theories on how embryonic structures may have evolved or have been modified over time.

"The embryo has features that are still ancient remnants that they have not lost yet, which provides insight into how animals have evolved," Mosimann says. "We can use the embryo to learn more about features that just persist today, allowing us to kind of travel back in time," Mosimann says. "We see that the body has a fundamental, inherent propensity to form bilateral, two-sided structures. Our study provides a molecular and genetic puzzle piece to resolve how we came to have limbs. It adds to this 100-plus year discussion, but now we have molecular insights."

International collaboration

Collaborations with colleagues in laboratories across the country and around the world are another important part of the study. Those scientists bring additional specializations and contribute data from other models, including paddlefish, African clawed frogs, and a variant of split-tail goldfish called Ranchu, to study embryonic development.

"There are labs on this on this paper that work on musculoskeletal diseases, toxicology, fibrosis. We work on cardiovascular, congenital anomalies, cardiopulmonary anomalies, limb development, all related to our interest on the lateral plate mesoderm," says Mosimann. "And then together, you get to make such fundamental discoveries. And that's where team science enables us to do something that is more than just the sum of the parts."

For all the considerable work and significance of the study, the Mosimann team recognizes that it is a key step, but not the end of the journey in the debate about paired appendages.

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Global flash droughts expected to increase in a warming climate

The rapid development of unexpected drought, called flash drought, can severely impact agricultural and ecological systems with ripple effects that extend even further. Researchers at the University of Oklahoma are assessing how our warming climate will affect the frequency of flash droughts and the risk to croplands globally.

Jordan Christian, a postdoctoral researcher, is the lead author of the study, "Global projections of flash drought show increased risk in a warming climate," published today in Nature Communications Earth and Environment.

"In this study, projected changes in flash drought frequency and cropland risk from flash drought are quantified using global climate model simulations," Christian said. "We find that flash drought occurrence is expected to increase globally among all scenarios, with the sharpest increases seen in scenarios with higher radiative forcing and greater fossil fuel usage."

Radiative forcing describes the imbalance of radiation where more radiation enters Earth's atmosphere than leaves it. Like burning fossil fuels, these activities are among the most significant contributors to climate warming. The changing climate is expected to increase severe weather events from storms, flash flooding, flash droughts and more.

"Flash drought risk over cropland is expected to increase globally, with the largest increases projected across North America and Europe," Christian said.

"CMIP6 models projected a 1.5 times increase in the annual risk of flash droughts over croplands across North America by 2100, from the 2015 baseline of a 32% yearly risk in 2015 to 49% in 2100, while Europe is expected to have the largest increase in the most extreme emissions scenario (32% to 53%), a 1.7 times increase in annual risk," he said.

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Plants remove cancer causing toxins from air

A ground-breaking study has revealed that plants can efficiently remove toxic gasoline fumes, including cancer causing compounds such as benzene, from indoor air.

The study was led by University of Technology Sydney (UTS) bioremediation researcher Associate Professor Fraser Torpy, in partnership with leading Australian plantscaping solutions company Ambius.

The researchers found that the Ambius small green wall, containing a mix of indoor plants, was highly effective at removing harmful, cancer-causing pollutants, with 97 per cent of the most toxic compounds removed from the surrounding air in just eight hours.

Poor indoor air quality is responsible for 6.7 million premature deaths globally, according to the World Health Organisation. Most people spend 90% of their time indoors at home, school or the workplace, so adopting new strategies to improve air quality is critical.

Ambius General Manager Johan Hodgson said the research presented new evidence into the critical role played by indoor plants and green walls in cleaning the air we breathe quickly and sustainably.

"We know that indoor air quality is often significantly more polluted than outdoor air, which in turn impacts mental and physical health. But the great news is this study has shown that something as simple as having plants indoors can make a huge difference," Mr Hodgson said.

Previous studies on indoor plants have shown they can remove a broad range of indoor air contaminants, however this is the first study into the ability of plants to clean up gasoline vapors, which are one of the largest sources of toxic compounds in buildings worldwide.

Offices and residential apartment buildings often connect directly to parking garages, either by doors or elevator shafts, making it difficult to avoid harmful gasoline-related compounds seeping into work and residential areas. Many buildings are also exposed to gasoline fumes from nearby roads and highways.

Breathing gasoline fumes can lead to lung irritation, headaches and nausea, and has been linked to an increased risk of cancer, asthma and other chronic diseases from longer term exposure, contributing to decreased life expectancy.

Associate Professor Torpy said the study results, based on measurements from a sealed chamber, had far exceeded their expectations when it came to removing gasoline pollutants from the air.

"This is the first time plants have been tested for their ability to remove gasoline-related compounds, and the results are astounding.

"Not only can plants remove the majority of pollutants from the air in a matter of hours, they remove the most harmful gasoline-related pollutants from the air most efficiently, for example, known carcinogen benzene is digested at a faster rate than less harmful substances, like alcohols.

"We also found that the more concentrated the toxins in the air, the faster and more effective the plants became at removing the toxins, showing that plants adapt to the conditions they're growing in," Associate Professor Torpy said.

Mr Hodgson said the findings confirmed feedback they'd received after installing plants in hundreds of office buildings across the nation.

"At Ambius, we see over and over again the effects plants have in improving health, wellbeing, productivity and office attendance for the thousands of businesses we work with. This new research proves that plants should not just be seen as 'nice to have', but rather a crucial part of every workplace wellness plan.

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