Agriculture: Less productive yet more stable pastures

Climate change will have a considerable influence on the biodiversity and productivity of meadows and pastures. However, according to the results of the large-scale climate and land use experiment, GCEF, which has been conducted at the Helmholtz Centre for Environmental Research (UFZ) for 10 years, the extent of these changes depends on the land use. Grassland optimised for high yield responds much more sensitively to periods of drought than less intensively used meadows and pastures. According to an article recently published in Global Change Biology, this can certainly have economic consequences for the farmers affected.

Grassland is one of the most important and most widespread ecosystems on earth. Such open landscapes with grasses and herbs not only cover more than one quarter of the entire land surface but also store at least one third of the terrestrial carbon, are crucial for food production, and can be extremely species-rich in a relatively small area. But what is the future of these habitats? The study provides new insights into this question.

It has long been clear that two environmental changes are threatening the world's grasslands. Particularly in Europe, grasslands are now fertilised much more heavily, mowed more frequently, and grazed more intensively. In addition, farmers often sow only a handful of grass varieties that promise a particularly high yield. This intensification of land use is fundamentally changing the species composition and functionality of meadows and pastures. The same applies to climate change. For Germany, climate change will result in a shift in the seasonal distribution of precipitation as well as an increase in hydrological extremes (e.g. heavy rainfall and droughts), among other things. It is considered the second largest threat for these ecosystems.

When both changes come together, they can reinforce each other. However, nobody yet knows exactly what will happen. Most experiments on this topic have so far focussed on either the climate or land use. "What makes our study unique is that we investigated the interaction of both factors," explains Dr Lotte Korell, biologist at the UFZ and first author of the publication.

This was made possible by the large-scale and long-term experiment of the UFZ in Bad Lauchstädt near Halle, the Global Change Experimental Facility (GCEF). It consists of 50 plots, each measuring 16 × 24 m; these are used with varying degrees of land use intensity. Temperatures and precipitation levels can also be manipulated with the help of mobile roof systems. For example, some plots receive 10% more precipitation in spring and autumn and 20% less in summer than the untreated control plots. This roughly corresponds to the conditions that climate models project for central Germany.

An eight-year data series from this experiment has now been compiled for the new study. The researchers analysed the biodiversity and productivity of the plants on the differently used plots between 2015 and 2022. "This period includes three of the driest years this region has experienced since beginning of records," recalls Korell. These droughts apparently had a much stronger effect on the plants than the experimentally simulated climate change.

However, in both cases, the trend pointed in the same direction: species-rich grassland that is only rarely mown or sparsely grazed withstood the heat and drought much better than the intensively used high-performance meadows. "Among other factors, this is probably related to the diversity of species," says Korell. This varied greatly depending on the land use of the grasslands.

A diverse mixture of more than 50 native grasses and herbs grew on the less intensively used meadows and pastures of the GCEF. However, on the intensively used grassland, the UFZ team had sown only the five grass varieties recommended to farmers by the Saxony-Anhalt State Institute for Agriculture and Horticulture for drier sites at the start of the experiment. These included varieties of meadow grass (Dactylis glomerata) and perennial ryegrass (Lolium perenne).

Because such grasses are bred for maximum yield and were also heavily fertilised -- as is common in agricultural practice -- the intensive meadows were initially much more productive than the more diverse grasslands. However, they were able to make use of this advantage only in favourable climatic conditions and were not able to withstand the drought as well as the plants in the low-intensity meadows and pastures. In times of drought, the grasses in the intensively used meadows increasingly died back and were replaced by other species such as chickweed (Stellaria media), shepherd's purse (Capsella bursa-pastoris), dandelion (Taraxacum officinale), and small-flowered cranesbill (Geranium pusillum). "These are mostly short-lived species that survive as seeds," explains Dr Harald Auge, also a biologist at the UFZ and senior author of the study. When the more competitive plants succumb to drought, these species take the opportunity to invade their habitats: they either migrate from the low-intensity grassland or germinate from the seed stock in the soil.

This shift in species composition is not particularly welcomed by farmers, especially because most of the new arrivals have a lower fodder quality than the grasses originally sown. The common ragwort (Senecio vulgaris), which was frequently represented among the immigrating species in the experiment, is in fact poisonous. All of this reduces the productivity of the land.

Farmers have long been aware of this kind of degradation of high-performance grassland by immigrating species. They therefore expect to have to plough up and reseed their land every few years. "However, climate change may accelerate this need and lead to additional costs," says Korell. Perhaps everything will go well for a few years and it will rain enough. However, it is also possible that several dry summers will follow one another. Climate change is making conditions even more unpredictable.

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Brain size riddle solved as humans exceed evolution trend

The largest animals do not have proportionally bigger brains -- with humans bucking this trend -- a new study published in Nature Ecology and Evolution has revealed.

Researchers at the University of Reading and Durham University collected an enormous dataset of brain and body sizes from around 1,500 species to clarify centuries of controversy surrounding brain size evolution.

Bigger brains relative to body size are linked to intelligence, sociality, and behavioural complexity -- with humans having evolved exceptionally large brains.

The new research, published today (Monday, 8 July), reveals the largest animals do not have proportionally bigger brains, challenging long-held beliefs about brain evolution.

Professor Chris Venditti, lead author of the study from the University of Reading, said: "For more than a century, scientists have assumed that this relationship was linear -- meaning that brain size gets proportionally bigger, the larger an animal is. We now know this is not true. The relationship between brain and body size is a curve, essentially meaning very large animals have smaller brains than expected."

Professor Rob Barton, co-author of the study from Durham University, said: "Our results help resolve the puzzling complexity in the brain-body mass relationship. Our model has a simplicity that means previously elaborate explanations are no longer necessary -- relative brain size can be studied using a single underlying model."

Beyond the ordinary

The research reveals a simple association between brain and body size across all mammals which allowed the researchers to identify the rule-breakers -- species which challenge the norm.

Among these outliers includes our own species, Homo sapiens, which has evolved more than 20 times faster than all other mammal species, resulting in the massive brains that characterise humanity today.

But humans are not the only species to buck this trend.

All groups of mammals demonstrated rapid bursts of change -- both towards smaller and larger brain sizes.

For example, bats very rapidly reduced their brain size when they first arose, but then showed very slow rates of change in relative brain size, suggesting there may be evolutionary constraints related to the demands of flight.

There are three groups of animals that showed the most pronounced rapid change in brain size: primates, rodents, and carnivores.

In these three groups, there is a tendency for relative brain size to increase in time (the "Marsh-Lartet rule"). This is not a trend universal across all mammals, as previously believed.

Read more at Science Daily

Chimpanzees gesture back and forth quickly like in human conversations

When people are having a conversation, they rapidly take turns speaking and sometimes even interrupt. Now, researchers who have collected the largest ever dataset of chimpanzee "conversations" have found that they communicate back and forth using gestures following the same rapid-fire pattern. The findings are reported on July 22 in the journal Current Biology.

"While human languages are incredibly diverse, a hallmark we all share is that our conversations are structured with fast-paced turns of just 200 milliseconds on average," said Catherine Hobaiter  at the University of St Andrews, UK. "But it was an open question whether this was uniquely human, or if other animals share this structure."

"We found that the timing of chimpanzee gesture and human conversational turn-taking is similar and very fast, which suggests that similar evolutionary mechanisms are driving these social, communicative interactions," says Gal Badihi, the study's first author.

The researchers knew that human conversations follow a similar pattern across people living in places and cultures all over the world. They wanted to know if the same communicative structure also exists in chimpanzees even though they communicate through gestures rather than through speech. To find out, they collected data on chimpanzee "conversations" across five wild communities in East Africa.

Altogether, they collected data on more than 8,500 gestures for 252 individuals. They measured the timing of turn-taking and conversational patterns. They found that 14% of communicative interactions included an exchange of gestures between two interacting individuals. Most of the exchanges included a two-part exchange, but some included up to seven parts.

Overall, the data reveal a similar timing to human conversation, with short pauses between a gesture and a gestural response at about 120 milliseconds. Behavioral responses to gestures were slower. "The similarities to human conversations reinforce the description of these interactions as true gestural exchanges, in which the gestures produced in response are contingent on those in the previous turn," the researchers write.

"We did see a little variation among different chimp communities, which again matches what we see in people where there are slight cultural variations in conversation pace: some cultures have slower or faster talkers," Badihi says.

"Fascinatingly, they seem to share both our universal timing, and subtle cultural differences," says Hobaiter. "In humans, it is the Danish who are 'slower' responders, and in Eastern chimpanzees that's the Sonso community in Uganda."

This correspondence between human and chimpanzee face-to-face communication points to shared underlying rules in communication, the researchers say. They note that these structures could trace back to shared ancestral mechanisms. It's also possible that chimpanzees and humans arrived at similar strategies to enhance coordinated interactions and manage competition for communicative "space." The findings suggest that human communication may not be as unique as one might think.

"It shows that other social species don't need language to engage in close-range communicative exchanges with quick response time," Badihi says. "Human conversations may share similar evolutionary history or trajectories to the communication systems of other species suggesting that this type of communication is not unique to humans but more widespread in social animals."

In future studies, the researchers say they want to explore why chimpanzees have these conversations to begin with. They think chimpanzees often rely on gestures to ask something of one another.

Read more at Science Daily

New dawn for space storm alerts could help shield Earth's tech

Space storms could soon be forecasted with greater accuracy than ever before thanks to a big leap forward in our understanding of exactly when a violent solar eruption may hit Earth.

Scientists say it is now possible to predict the precise speed a coronal mass ejection (CME) is travelling at and when it will smash into our planet -- even before it has fully erupted from the Sun.

CMEs are bursts of gas and magnetic fields spewed into space from the solar atmosphere.

They can cause geomagnetic storms that have the potential to wreak havoc with terrestrial technology in Earth's orbit and on its surface, which is why experts across the globe are striving to improve space weather forecasts.

Advancements such as this one could make a huge difference in helping to protect infrastructure that is vital to our everyday lives, according to researchers at Aberystwyth University, who will present their findings today at the Royal Astronomical Society's National Astronomy Meeting in Hull.

They made their discovery after studying specific areas on the Sun called 'Active Regions', which have strong magnetic fields where CMEs are born. The researchers monitored how these areas changed in the periods before, during and after an eruption.

A vital aspect which they looked at was the "critical height" of the Active Regions, which is the height at which the magnetic field becomes unstable and can lead to a CME.

"By measuring how the strength of the magnetic field decreases with height, we can determine this critical height," said lead researcher Harshita Gandhi, a solar physicist at Aberystwyth University.

"This data can then be used along with a geometric model which is used to track the true speed of CMEs in three dimensions, rather than just two, which is essential for precise predictions."

She added: "Our findings reveal a strong relationship between the critical height at CME onset and the true CME speed.

"This insight allows us to predict the CME's speed and, consequently, its arrival time on Earth, even before the CME has fully erupted."

When these CMEs hit the Earth they can trigger a geomagnetic storm which is capable of producing stunning aurorae, often referred to in the northern hemisphere as the Northern Lights.

But the storms also have the potential to disrupt vital systems we rely on daily, including satellites, power grids, and communication networks, which is why scientists worldwide are working hard to improve our ability to better predict when CMEs will hit Earth.

This requires knowing a more accurate speed of the CME shortly after it erupts from the Sun to better provide advance warnings of when it will reach our planet.

Accurate speed predictions enable better estimates of when a CME will reach Earth, providing crucial advance warnings.

"Understanding and using the critical height in our forecasts improves our ability to warn about incoming CMEs, helping to protect the technology that our modern lives depend on," Gandhi said.

"Our research not only enhances our understanding of the Sun's explosive behaviour but also significantly improves our ability to forecast space weather events.

Read more at Science Daily

Chemists design novel method for generating sustainable fuel

Chemists have been working to synthesize high-value materials from waste molecules for years. Now, an international collaboration of scientists is exploring ways to use electricity to streamline the process.

In their study, recently published in Nature Catalysis, researchers demonstrated that carbon dioxide, a greenhouse gas, can be converted into a type of liquid fuel called methanol in a highly efficient manner.

This process happened by taking cobalt phthalocyanine (CoPc) molecules and spreading them evenly on carbon nanotubes, graphene-like tubes that have unique electrical properties. On their surface was an electrolyte solution, which, by running an electrical current through it, allowed CoPc molecules to take electrons and use them to turn carbon dioxide into methanol.

Using a special method based on in-situ spectroscopy to visualize the chemical reaction, researchers for the first time saw those molecules convert themselves into either methanol or carbon monoxide, which is not the desired product. They found that which path the reaction takes is decided by the environment where the carbon dioxide molecule reacts.

Tuning this environment by controlling how the CoPc catalyst was distributed on the carbon nanotube surface allowed carbon dioxide to be as much as eight times more likely to produce methanol, a discovery that could increase the efficiency of other catalytic processes and have a widespread impact on other fields, said Robert Baker, co-author of the study and a professor in chemistry and biochemistry at The Ohio State University.

"When you take carbon dioxide and convert it to another product, there are many different molecules you can make," he said. "Methanol is definitely one of the most desirable because it has such a high energy density and can be used directly as an alternative fuel."

While transforming waste molecules into useful products isn't a new phenomenon, until now, researchers have often been unable to watch how the reaction actually takes place, a crucial insight into being able to optimize and improve the process.

"We might empirically optimize how something works, but we don't really have an understanding of what makes it work, or what makes one catalyst work better than another catalyst," said Baker, who specializes in surface chemistry, the study of how chemical reactions change when they occur on the face of different objects. "These are very difficult things to answer."

But with the help of special techniques and computer modeling, the team has come significantly closer to grasping the complex process. In this study, researchers used a new type of vibrational spectroscopy, which allowed them to see how molecules behave on the surface, said Quansong Zhu, the lead author of the study and former Ohio State Presidential Scholar whose challenging measurements were vital to the discovery.

"We could tell by their vibrational signatures that it was the same molecule sitting in two different reaction environments," said Zhu. "We were able to correlate that one of those reaction environments was responsible for producing methanol, which is valuable liquid fuel."

According to the study, deeper analysis also found these molecules were directly interacting with supercharged particles called cations that enhanced the process of methanol formation.

More research is needed to learn more about what else these cations enable, but such a finding is key to achieving a more efficient way to create methanol, said Baker.

"We're seeing systems that are very important and learning things about them that have been wondered about for a long time," said Baker. "Understanding the unique chemistry that happens at a molecular level is really important to enabling these applications."

Besides being a low-cost fuel for vehicles like planes, cars and shipping boats, methanol produced from renewable electricity could also be utilized for heating and power generation, and to advance future chemical discoveries.

"There's a lot of exciting things that can come next based on what we've learned here, and some of that we're already starting to do together," said Baker. "The work is ongoing."

Read more at Science Daily

Study shows promise for a universal influenza vaccine

New research led by Oregon Health & Science University reveals a promising approach to developing a universal influenza vaccine -- a so-called "one and done" vaccine that confers lifetime immunity against an evolving virus.

The study, published today in the journal Nature Communications, tested an OHSU-developed vaccine platform against the virus considered most likely to trigger the next pandemic.

Researchers reported the vaccine generated a robust immune response in nonhuman primates that were exposed to the avian H5N1 influenza virus. But the vaccine wasn't based on the contemporary H5N1 virus; instead, the primates were inoculated against the influenza virus of 1918 that killed millions of people worldwide.

"It's exciting because in most cases, this kind of basic science research advances the science very gradually; in 20 years, it might become something," said senior author Jonah Sacha, Ph.D., professor and chief of the Division of Pathobiology at OHSU's Oregon National Primate Research Center. "This could actually become a vaccine in five years or less."

Researchers reported that six of 11 nonhuman primates inoculated against the virus that circulated a century ago -- the 1918 flu -- survived exposure to one of the deadliest viruses in the world today, H5N1. In contrast, a control group of six unvaccinated primates exposed to the H5N1 virus succumbed to the disease.

Sacha said he believes the platform "absolutely" could be useful against other mutating viruses, including SARS-CoV-2.

"It's a very viable approach," he said. "For viruses of pandemic potential, it's critical to have something like this. We set out to test influenza, but we don't know what's going to come next."

A senior co-author from the University of Pittsburgh concurred.

"Should a deadly virus such as H5N1 infect a human and ignite a pandemic, we need to quickly validate and deploy a new vaccine," said co-corresponding author Douglas Reed, Ph.D., associate professor of immunology at the University of Pittsburgh Center for Vaccine Research.

Finding a stationary target

This approach harnesses a vaccine platform previously developed by scientists at OHSU to fight HIV and tuberculosis, and in fact is already being used in a clinical trial against HIV.

The method involves inserting small pieces of target pathogens into the common herpes virus cytomegalovirus, or CMV, which infects most people in their lifetimes and typically produces mild or no symptoms. The virus acts as a vector specifically designed to induce an immune response from the body's own T cells.

This approach differs from common vaccines -- including the existing flu vaccines -- which are designed to induce an antibody response that targets the most recent evolution of the virus, distinguished by the arrangement of proteins covering the exterior surface.

"The problem with influenza is that it's not just one virus," Sacha said. "Like the SARS-CoV-2 virus, it's always evolving the next variant and we're always left to chase where the virus was, not where it's going to be."

The spike proteins on the virus exterior surface evolve to elude antibodies. In the case of flu, vaccines are updated regularly using a best estimate of the next evolution of the virus. Sometimes it's accurate, sometimes less so.

In contrast, a specific type of T cell in the lungs, known as effector memory T cell, targets the internal structural proteins of the virus, rather than its continually mutating outer envelope. This internal structure doesn't change much over time -- presenting a stationary target for T cells to search out and destroy any cells infected by an old or newly evolved influenza virus.

Success with a century-old template

To test their T cell theory, researchers designed a CMV-based vaccine using the 1918 influenza virus as a template. Working within a highly secure biosafety level 3 laboratory at the University of Pittsburgh, they exposed the vaccinated nonhuman primates to small particle aerosols containing the avian H5N1 influenza virus -- an especially severe virus that is currently circulating among dairy cows in the United States.

Remarkably, six of the 11 vaccinated primates survived the exposure, despite the century-long period of virus evolution.

"It worked because the interior protein of the virus was so well preserved," Sacha said. "So much so, that even after almost 100 years of evolution, the virus can't change those critically important parts of itself."

The study raises the potential for developing a protective vaccine against H5N1 in people.

"Inhalation of aerosolized H5N1 influenza virus causes a cascade of events that can trigger respiratory failure," said co-senior author Simon Barratt-Boyes, Ph.D., professor of infectious diseases, microbiology and immunology at Pitt. "The immunity induced by the vaccine was sufficient to limit virus infection and lung damage, protecting the monkeys from this very serious infection."

By synthesizing more up-to-date virus templates, the new study suggests CMV vaccines may be able to generate an effective, long-lasting immune response against a wide suite of new variants.

"I think it means within five to 10 years, a one-and-done shot for influenza is realistic," Sacha said.

The same CMV platform developed by OHSU researchers has advanced to a clinical trial to protect against HIV, and a recent publication by those scientists suggests it may even be useful targeting specific cancer cells. The HIV clinical trial is being led by Vir Biotechnology, which licensed the vaccine platform from OHSU.

Sacha sees the development as the latest in the rapid advance of medical research to treat or prevent disease.

"It's a massive sea change within our lifetimes," Sacha said. "There is no question we are on the cusp of the next generation of how we address infectious disease."

Read more at Science Daily

New snake discovery rewrites history, points to North America's role in snake evolution

A new species of fossil snake unearthed in Wyoming is rewriting our understanding of snake evolution. The discovery, based on four remarkably well-preserved specimens found curled together in a burrow, reveals a new species named Hibernophis breithaupti. This snake lived in North America 34 million years ago and sheds light on the origin and diversification of boas and pythons.

Hibernophis breithaupti has unique anatomical features, in part because the specimens are articulated -- meaning they were found all in one piece with the bones still arranged in the proper order -- which is unusual for fossil snakes.

Researchers believe it may be an early member of Booidea, a group that includes modern boas and pythons.

Modern boas are widespread in the Americas, but their early evolution is not well understood.These new and very complete fossils add important new information, in particular, on the evolution of small, burrowing boas known as rubber boas.

Traditionally, there has been much debate on the evolution of small burrowing boas.

Hibernophis breithaupti shows that northern and more central parts of North America might have been a key hub for their development.

The discovery of these snakes curled together also hints at the oldest potential evidence for a behavior familiar to us today -- hibernation in groups.

"Modern garter snakes are famous for gathering by the thousands to hibernate together in dens and burrows," says Michael Caldwell, a U of A paleontologist who co-led the research along with his former graduate student Jasmine Croghan, and collaborators from Australia and Brazil. "They do this to conserve heat through the effect created by the ball of hibernating animals. It's fascinating to see possible evidence of such social behavior or hibernation dating back 34 million years."

From Science Daily

Exoplanet-hunting telescope to begin search for another Earth in 2026

Europe's next big space mission -- a telescope that will hunt for Earth-like rocky planets outside of our solar system -- is on course to launch at the end of 2026.

PLATO, or PLAnetary Transits and Oscillations of stars, is being built to find nearby potentially habitable worlds around Sun-like stars that we can examine in detail.

The space telescope will blast into orbit on Europe's new rocket, Ariane-6, which made its maiden flight last week after being developed at a cost of €4billion (£3.4billion).

Dr David Brown, of the University of Warwick, is giving an update on the mission at the Royal Astronomical Society's National Astronomy Meeting at the University of Hull this week.

"PLATO's goal is to search for exoplanets around stars similar to the Sun and at orbital periods long enough for them to be in the habitable zone," he said.

"One of the main mission objectives is to find another Earth-Sun equivalent pair, but it is also designed to carefully and precisely characterise the exoplanets that it finds (i.e. work out their masses, radii, and bulk density)."

PLATO isn't just an exoplanet hunter, however. It is also a stellar science mission.

As well as searching for exoplanets it will study the stars using a range of techniques including asteroseismology (measuring the vibrations and oscillations of stars) to work out their masses, radii, and ages.

Unlike most space telescopes, PLATO has multiple cameras -- including a UK-named one called ArthurEddington, after the famous astronomer and physicist who won the Royal Astronomical Society's Gold Medal in 1924.

It has 24 'Normal' cameras (N-CAMs) and 2 'Fast' cameras (F-CAMs). The N-CAMs are arranged into four groups of six cameras, with the cameras in each group pointing in the same direction but the groups slightly offset.

This gives PLATO a very large field of view, improved scientific performance, redundancy against failures, and a built-in way to identify 'false positive' signals that might mimic an exoplanet transit, Dr Brown explained.

"The planned observing strategy is to stare at two patches of sky, one in the North and one in the South, for two years each," he added.

"The Southern patch of sky has been chosen, while the Northern patch won't be confirmed for another few years."

Several of the spacecraft's components have finished their manufacturing programmes and are close to completing their calibration tests. This includes the UK-provided Front-End Electronics (FEE) for the N-CAMs.

Built by the Mullard Space Science Laboratory of University College London, these operate the cameras, digitise the images, and transfer them to the onboard data processing.

Ten of the final cameras have been built and tested and the first of these was mounted onto the optical bench -- the surface which keeps all cameras pointed in the right direction -- earlier this year.

Read more at Science Daily

New humidity-driven membrane to remove carbon dioxide from the air

A new ambient-energy-driven membrane that pumps carbon dioxide out of the air has been developed by Newcastle University researchers.

Direct air capture was identified as one of the 'Seven chemical separations to change the world'. This is because although carbon dioxide is the main contributor to climate change (we release ~40 billion tons into the atmosphere every year), separating carbon dioxide from air is very challenging due to its dilute concentration (~0.04%).

Prof Ian Metcalfe, Royal Academy of Engineering Chair in Emerging Technologies in the School of Engineering, Newcastle University, UK, and lead investigator states, "Dilute separation processes are the most challenging separations to perform for two key reasons. First, due to the low concentration, the kinetics (speed) of chemical reactions targeting the removal of the dilute component are very slow. Second, concentrating the dilute component requires a lot of energy."

These are the two challenges that the Newcastle researchers (with colleagues at the Victoria University of Wellington, New Zealand, Imperial College London, UK, Oxford University, UK, Strathclyde University, UK and UCL, UK) set out to address with their new membrane process. By using naturally occurring humidity differences as a driving force for pumping carbon dioxide out of air, the team overcame the energy challenge. The presence of water also accelerated the transport of carbon dioxide through the membrane, tackling the kinetic challenge.

The work is published in Nature Energy and Dr Greg A. Mutch, Royal Academy of Engineering Fellow in the School of Engineering, Newcastle University, UK explains, "Direct air capture will be a key component of the energy system of the future. It will be needed to capture the emissions from mobile, distributed sources of carbon dioxide that cannot easily be decarbonised in other ways."

"In our work, we demonstrate the first synthetic membrane capable of capturing carbon dioxide from air and increasing its concentration without a traditional energy input like heat or pressure. I think a helpful analogy might be a water wheel on a flour mill. Whereas a mill uses the downhill transport of water to drive milling, we use it to pump carbon dioxide out of the air."

Separation processes

Separation processes underpin most aspects of modern life. From the food we eat, to the medicines we take, and the fuels or batteries in our car, most products we use have been through several separation processes. Moreover, separation processes are important for minimising waste and the need for environmental remediation, such as direct air capture of carbon dioxide.

However, in a world moving towards a circular economy, separation processes will become even more critical. Here, direct air capture might be used to provide carbon dioxide as a feedstock for making many of the hydrocarbon products we use today, but in a carbon-neutral, or even carbon-negative, cycle.

Most importantly, alongside transitioning to renewable energy and traditional carbon capture from point sources like power plants, direct air capture is necessary for realising climate targets, such as the 1.5 °C goal set by the Paris Agreement.

The humidity-driven membrane

Dr Evangelos Papaioannou, Senior Lecturer in the School of Engineering, Newcastle University, UK explains, "In a departure from typical membrane operation, and as described in the research paper, the team tested a new carbon dioxide-permeable membrane with a variety of humidity differences applied across it. When the humidity was higher on the output side of the membrane, the membrane spontaneously pumped carbon dioxide into that output stream."

Using X-ray micro-computed tomography with collaborators at UCL and the University of Oxford, the team were able to precisely characterise the structure of the membrane. This enabled them to provide robust performance comparisons with other state-of-the-art membranes.

A key aspect of the work was modelling the processes occurring in the membrane at the molecular scale. Using density-functional-theory calculations with a collaborator affiliated to both Victoria University of Wellington and Imperial College London, the team identified 'carriers' within the membrane. The carrier uniquely transports both carbon dioxide and water but nothing else. Water is required to release carbon dioxide from the membrane, and carbon dioxide is required to release water. Because of this, the energy from a humidity difference can be used to drive carbon dioxide through the membrane from a low concentration to a higher concentration.

Read more at Science Daily

Good timing: Study unravels how our brains track time

Ever hear the old adage that time flies when you're having fun? A new study by a team of UNLV researchers suggests that there's a lot of truth to the trope.

Many people think of their brains as being intrinsically synced to the human-made clocks on their electronic devices, counting time in very specific, minute-by-minute increments. But the study, published this month in the latest issue of the peer-reviewed Cell Press journal Current Biology, showed that our brains don't work that way.

By analyzing changes in brain activity patterns, the research team found that we perceive the passage of time based on the number of experiences we have -- not some kind of internal clock. What's more, increasing speed or output during an activity appears to affect how our brains perceive time.

"We tell time in our own experience by things we do, things that happen to us," said James Hyman, a UNLV associate professor of psychology and the study's senior author. "When we're still and we're bored, time goes very slowly because we're not doing anything or nothing is happening. On the contrary, when a lot of events happen, each one of those activities is advancing our brains forward. And if this is how our brains objectively tell time, then the more that we do and the more that happens to us, the faster time goes."

Methodology and Findings

The findings are based on analysis of activity in the anterior cingulate cortex (ACC), a portion of the brain important for monitoring activity and tracking experiences. To do this, rodents were tasked with using their noses to respond to a prompt 200 times.

Scientists already knew that brain patterns are similar, but slightly different, each time you do a repetitive motion, so they set out to answer: Is it possible to detect whether these slight differences in brain pattern changes correspond with doing the first versus 200th motion in series? And does the amount of time it takes to complete a series of motions impact brain wave activity?

By comparing pattern changes throughout the course of the task, researchers observed that there are indeed detectable changes in brain activity that occur as one moves from the beginning to middle to end of carrying out a task. And regardless of how slowly or quickly the animals moved, the brain patterns followed the same path. The patterns were consistent when researchers applied a machine learning-based mathematical model to predict the flow of brain activity, bolstering evidence that it's experiences -- not time, or a prescribed number of minutes, as you would measure it on a clock -- that produce changes in our neurons' activity patterns.

Hyman drove home the crux of the findings by sharing an anecdote of two factory workers tasked with making 100 widgets during their shift, with one worker completing the task in 30 minutes and the other in 90 minutes.

"The length of time it took to complete the task didn't impact the brain patterns. The brain is not a clock; it acts like a counter," Hyman explained. "Our brains register a vibe, a feeling about time. ...And what that means for our workers making widgets is that you can tell the difference between making widget No. 85 and widget No. 60, but not necessarily between No. 85 and No. 88."

But exactly "how" does the brain count? Researchers discovered that as the brain progresses through a task involving a series of motions, various small groups of firing cells begin to collaborate -- essentially passing off the task to a different group of neurons every few repetitions, similar to runners passing the baton in a relay race.

"So, the cells are working together and over time randomly align to get the job done: one cell will take a few tasks and then another takes a few tasks," Hyman said. "The cells are tracking motions and, thus, chunks of activities and time over the course of the task."

And the study's findings about our brains' perception of time applies to activities-based actions other than physical motions too.

"This is the part of the brain we use for tracking something like a conversation through dinner," Hyman said. "Think of the flow of conversation and you can recall things earlier and later in the dinner. But to pick apart one sentence from the next in your memory, it's impossible. But you know you talked about one topic at the start, another topic during dessert, and another at the end."

By observing the rodents who worked quickly, scientists also concluded that keeping up a good pace helps influence time perception: "The more we do, the faster time moves. They say that time flies when you're having fun. As opposed to having fun, maybe it should be 'time flies when you're doing a lot'."

Takeaways

While there's already a wealth of information on brain processes over very short time scales of less than a second, Hyman said that the UNLV study is groundbreaking in its examination of brain patterns and perception of time over a span of just a few minutes to hours -- "which is how we live much of our life: one hour at a time. "

"This is among the first studies looking at behavioral time scales in this particular part of the brain called the ACC, which we know is so important for our behavior and our emotions," Hyman said.

The ACC is implicated in most psychiatric and neurodegenerative disorders, and is a concentration area for mood disorders, PTSD, addiction, and anxiety. ACC function is also central to various dementias including Alzheimer's disease, which is characterized by distortions in time. The ACC has long been linked to helping humans with sequencing events or tasks such as following recipes, and the research team speculates that their findings about time perception might fall within this realm.

While the findings are a breakthrough, more research is needed. Still, Hyman said, the preliminary findings posit some potentially helpful tidbits about time perception and its likely connection to memory processes for everyday citizens' daily lives. For example, researchers speculate that it could lend insights for navigating things like school assignments or even breakups.

"If we want to remember something, we may want to slow down by studying in short bouts and take time before engaging in the next activity. Give yourself quiet times to not move," Hyman said. "Conversely, if you want to move on from something quickly, get involved in an activity right away."

Hyman said there's also a huge relationship between the ACC, emotion, and cognition. Thinking of the brain as a physical entity that one can take ownership over might help us control our subjective experiences.

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