Study shedding new light on Earth's global carbon cycle could help assess liveability of other planets

Research has uncovered important new insights into the evolution of oxygen, carbon, and other vital elements over the entire history of Earth – and it could help assess which other planets can develop life, ranging from plants to animals and humans.

The study, published today in Nature Geoscience and led by a researcher at the University of Bristol, reveals for the first time how the build up of carbon-rich rocks has accelerated oxygen production and its release into the atmosphere.

Until now the exact nature of how the atmosphere became oxygen-rich has long eluded scientists and generated conflicting explanations.

As carbon dioxide is steadily emitted by volcanoes, it ends up entering the ocean and forming rocks like limestone.

As global stocks of these rocks build up they can then release their carbon during tectonic processes, including mountain building and metamorphism.

Using this knowledge, the scientists built a unique sophisticated computer model to more accurately chart key changes in the carbon, nutrient and oxygen cycles deep into Earth’s history, over 4 billion years of the planet’s lifetime.

Lead author and biogeochemist Dr Lewis Alcott, Lecturer in Earth Sciences at the University of Bristol, said: “This breakthrough is important and exciting because it may help us understand how planets, other than Earth, have the potential to support intelligent, oxygen-breathing life.

“Previously we didn’t have a clear idea of why oxygen rose from very low concentrations to present-day concentrations, as computer models haven’t previously been able to accurately simulate all the possible feedbacks together. This has puzzled scientists for decades and created different theories.”

The discovery indicates that older planets, originating billions of years ago like Earth, may have better prospects to accumulate enough carbon-rich deposits in their crust, which could facilitate rapid recycling of carbon and nutrients for life.

The findings showed this gradual carbon enrichment of the crust results in ever-increasing recycling rates of carbon and various minerals, including the nutrients needed for photosynthesis, the process green plants use sunlight to absorb nutrients from carbon dioxide and water.

This cycle therefore steadily speeds up oxygen production over the passage of Earth’s history.

The research, which started whilst Dr Alcott was a Hutchinson Postdoctoral Fellow at Yale University in the United States, paves the way for future work to further unravel the complex interrelationships between planetary temperature, oxygen, and nutrients.

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Juno spacecraft measures oxygen production on Jupiter's moon, Europa

NASA's Juno spacecraft has directly measured charged oxygen and hydrogen molecules from the atmosphere of one of Jupiter's largest moons, Europa. According to a new study co-authored by SwRI scientists and led by Princeton University, these observations provide key constraints on the potential oxygenation of its subsurface ocean.

"These findings have direct implications on the potential habitability of Europa," said Juno Principal Investigator Dr. Scott Bolton of SwRI, a co-author of the study.

"This study provides the first direct in-situ measurement of water components existing in Europa's atmosphere, giving us a narrow range that could support habitability."

In 2022, Juno completed a flyby of Europa, coming as close as 352 kilometers to the moon.

The SwRI-developed Jovian Auroral Distributions Experiment (JADE) instrument aboard Juno detected significant amounts of charged molecular oxygen and hydrogen lost from the atmosphere.

"For the first time, we've been able to definitively detect hydrogen and oxygen with in-situ measurements and further confirm that Europa's atmosphere is made primarily of hydrogen and oxygen molecules," said SwRI Staff Scientist and co-author Dr. Robert Ebert.

The source of these molecules is thought to be water ice on Europa's surface.

Jupiter's rampant radiation breaks H2O's molecular bonds, leaving behind oxygen and hydrogen.

The heavier oxygen molecules remain more constrained to the surface, or near-surface atmosphere, while the lighter-weight hydrogen predominately escapes into the atmosphere and beyond.

Oxygen produced in the ice is either lost from the atmosphere and/or sequestered in the surface.

Oxygen retained in Europa's ice may work its way to its subsurface ocean as a possible source of metabolic energy.

"Europa's ice shell absorbs radiation, protecting the ocean underneath. This absorption also produces oxygen within the ice, so in a way, the ice shell acts as Europa's lung, providing a potential oxygen source for the ocean." said Princeton University Research Scholar Dr. Jamey Szalay, the study's lead author.

"We put narrow constraints on the total oxygen production at Europa currently at around 12 kg per second. Before Juno, previous estimates ranged from a few kg per second to over 1,000 kg per second. The findings unambiguously demonstrate oxygen is continuously produced in the surface, just a good bit lower than we expected."

"We designed JADE to measure the charged particles that create Jupiter's auroras," said SwRI Staff Scientist and co-author Dr. Frederic Allegrini.

"Flybys of Europa were not part of the primary Juno mission. JADE was designed to work in a high-radiation environment but not necessarily Europa's environment, which is constantly bombarded with high levels of radiation. Nonetheless, the instrument performed beautifully."

The new measurements contribute to a greater understanding of Europa and its environment, open the door for newer, more precise models.

The study's new estimation of how much oxygen is produced within Europa's surface, for instance, could inform future research related to its subsurface ocean and potential habitability.

As these observations provide the first charged particle composition measurements within Europa's vicinity, they provide an important new window into the moons' complex interaction with its environment.

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Is oxygen the cosmic key to alien technology?

In the quest to understand the potential for life beyond Earth, researchers are widening their search to encompass not only biological markers, but also technological ones. While astrobiologists have long recognized the importance of oxygen for life as we know it, oxygen could also be a key to unlocking advanced technology on a planetary scale.

In a new study published in Nature Astronomy, Adam Frank, the Helen F. and Fred H. Gowen Professor of Physics and Astronomy at the University of Rochester and the author of The Little Book of Aliens (Harper, 2023), and Amedeo Balbi, an associate professor of astronomy and astrophysics at the University of Roma Tor Vergata, Italy, outline the links between atmospheric oxygen and the potential rise of advanced technology on distant planets.

"We are ready to find signatures of life on alien worlds," Frank says.

"But how do the conditions on a planet tell us about the possibilities for intelligent, technology-producing life?"

"In our paper, we explore whether any atmospheric composition would be compatible with the presence of advanced technology," Balbi says.

"We found that the atmospheric requirements may be quite stringent."

Igniting cosmic technospheres

Frank and Balbi posit that, beyond its necessity for respiration and metabolism in multicellular organisms, oxygen is crucial to developing fire -- and fire is a hallmark of a technological civilization.

They delve into the concept of "technospheres," expansive realms of advanced technology that emit telltale signs -- called "technosignatures" -- of extraterrestrial intelligence.

On Earth, the development of technology demanded easy access to open-air combustion -- the process at the heart of fire, in which something is burned by combining a fuel and an oxidant, usually oxygen.

Whether it's cooking, forging metals for structures, crafting materials for homes, or harnessing energy through burning fuels, combustion has been the driving force behind industrial societies.

Tracing back through Earth's history, the researchers found that the controlled use of fire and the subsequent metallurgical advancements were only possible when oxygen levels in the atmosphere reached or exceeded 18 percent.

This means that only planets with significant oxygen concentrations will be capable of developing advanced technospheres, and, therefore, leaving detectable technosignatures.

The oxygen bottleneck

The levels of oxygen required to biologically sustain complex life and intelligence are not as high as the levels necessary for technology, so while a species might be able to emerge in a world without oxygen, it will not be able to become a technological species, according to the researchers.

"You might be able to get biology -- you might even be able to get intelligent creatures -- in a world that doesn't have oxygen," Frank says, "but without a ready source of fire, you're never going to develop higher technology because higher technology requires fuel and melting."

Enter the "oxygen bottleneck," a term coined by the researchers to describe the critical threshold that separates worlds capable of fostering technological civilizations from those that fall short.

That is, oxygen levels are a bottleneck that impedes the emergence of advanced technology.

"The presence of high degrees of oxygen in the atmosphere is like a bottleneck you have to get through in order to have a technological species," Frank says.

"You can have everything else work out, but if you don't have oxygen in the atmosphere, you're not going to have a technological species."

Targeting extraterrestrial hotspots

The research, which addresses a previously unexplored facet in the cosmic pursuit of intelligent life, underscores the need to prioritize planets with high oxygen levels when searching for extraterrestrial technosignatures.

"Targeting planets with high oxygen levels should be prioritized because the presence or absence of high oxygen levels in exoplanet atmospheres could be a major clue in finding potential technosignatures," Frank says.

"The implications of discovering intelligent, technological life on another planet would be huge," adds Balbi.

"Therefore, we need to be extremely cautious in interpreting possible detections. Our study suggests that we should be skeptical of potential technosignatures from a planet with insufficient atmospheric oxygen."

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Window to the past: New microfossils suggest earlier rise in complex life

Microfossils from Western Australia may capture a jump in the complexity of life that coincided with the rise of oxygen in Earth's atmosphere and oceans, according to an international team of scientists.

The findings, published in the journal Geobiology, provide a rare window into the Great Oxidation Event, a time roughly 2.4 billion years ago when the oxygen concentration increased on Earth, fundamentally changing the planet's surface. The event is thought to have triggered a mass extinction and opened the door for the development of more complex life, but little direct evidence had existed in the fossil record before the discovery of the new microfossils, the scientists said.

"What we show is the first direct evidence linking the changing environment during the Great Oxidation Event with an increase in the complexity of life," said corresponding author Erica Barlow, an affiliate research professor in the Department of Geosciences at Penn State. "This is something that's been hypothesized, but there's just such little fossil record that we haven't been able to test it."

When compared to modern organisms, the microfossils more closely resembled a type of algae than simpler prokaryotic life -- organisms like bacteria, for example -- that existed prior to the Great Oxidation Event, the scientists said. Algae, along with all other plants and animals, are eukaryotes, more complex life whose cells have a membrane-bound nucleus.

More work is required to determine if the microfossils were left behind by eukaryotic organisms, but the possibility would have significant implications, the scientists said. It would push back the known eukaryotic microfossil record by 750 million years.

"The microfossils have a remarkable similarity to a modern family called Volvocaceae," Barlow said. "This hints at the fossil being possibly an early eukaryotic fossil. That's a big claim, and something that needs more work, but it raises an exciting question that the community can build on and test."

Barlow discovered the rock containing the fossils while conducting her undergraduate research at the University of New South Wales (USNW) in Australia, and she conducted the current work as part of her doctoral work at UNSW and then while a postdoctoral researcher at Penn State.

"These specific fossils are remarkably well preserved, which allowed for the combined study of their morphology, composition, and complexity," said Christopher House, professor of geosciences at Penn State and a co-author of the study. "The results provide a great window into a changing biosphere billions of years ago."

The scientists analyzed the chemical makeup and carbon isotopic composition of the microfossils and determined the carbon was created by living organisms, confirming that the structures were indeed biologic fossils. They also uncovered insights into the habitat, reproduction and metabolism of the microorganisms.

Barlow compared the samples to microfossils from before the Great Oxidation Event and could not find comparable organisms. The microfossils she found were larger and featured more complex cellular arrangements, she said.

"The record seems to reveal a burst of life -- there's an increase in diversity and complexity of this fossilized life that we are finding," Barlow said.

Compared to modern organisms, Barlow said, the microfossils have explicit similarities with algal colonies, including in the shape, size and distribution of both the colony and individual cells and membranes around both cell and colony.

"They have a remarkable similarity and so, by that way of comparison, we could say these fossils were relatively complex," Barlow said. "There is nothing like them in the fossil record, and yet, they have quite striking similarities to modern algae."

The findings have implications for both how long it took complex life to form on early Earth -- the earliest, uncontroversial evidence of life is 3.5 billion years old -- and what the search for life elsewhere in the solar system may reveal, the scientists said.

"I think finding a fossil that is this relatively large and complex, relatively early on in the history of life on Earth, kind of makes you question -- if we do find life elsewhere, it might not just be bacterial prokaryotic life," Barlow said. "Maybe there's a chance there could be something more complex preserved -- even if it's still microscopic, it could be something of a slightly higher order."

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Beaver activity in the Arctic increases emission of methane greenhouse gas

The climate-driven advance of beavers into the Arctic tundra is causing the release of more methane -- a greenhouse gas -- into the atmosphere.

Beavers, as everyone knows, like to make dams. Those dams cause flooding, which inundates vegetation and turns Arctic streams and creeks into a series of ponds. Those beaver ponds and surrounding inundated vegetation can be devoid of oxygen and rich with organic sediment, which releases methane as the material decays.

Methane is also released when organics-rich permafrost thaws as the result of heat carried by the spreading water.

A study linking Arctic beavers to an increase in the release of methane was published in July in Environmental Research Letters.

The lead author is Jason Clark, a former postdoctoral fellow at the University of Alaska Fairbanks Geophysical Institute. Research Professor Ken Tape, also of the Geophysical Institute, was Clark's adviser and is a co-author. Other co-authors include Benjamin Jones, a research assistant professor at the UAF Institute of Northern Engineering; and researchers from the National Park Service and NASA's Jet Propulsion Laboratory.

Tape has done extensive research about the northward migration of beavers and their resultant impact on the Arctic environment.

"What we found is that there are lots of methane hotspots right next to ponds and they start to diminish as you go away from the pond," he said.

The new study is the first to link large numbers of new beaver ponds to methane emissions at the landscape scale. It suggests that beaver engineering in the Arctic will at least initially increase methane release.

"We say 'initially' because that's the data we have," Tape said. "What the longer-term implications are, we don't know."

As a greenhouse gas, methane is 25 times more potent than carbon dioxide at trapping heat in Earth's atmosphere.

It accounts for about 20 percent of global greenhouse gas emissions, according to the U.S. Environmental Protection Agency. The agency says human activities have more than doubled atmospheric methane concentrations in the past two centuries.

The new research focused on 166 square miles of the lower Noatak River basin in Northwest Alaska. Data was obtained by airborne hyperspectral imaging through NASA's Arctic-Boreal Vulnerability Experiment program. That program and the National Science Foundation funded the research.

Hyperspectral cameras image an area in hundreds of wavelengths across the electromagnetic spectrum, including many not visible to the human eye. That differs from other cameras, which typically only image in the primary colors of red, green and blue.

The researchers compared the location of methane hot spots to the locations of 118 beaver ponds and to a number of nearby unaffected stream reaches and lakes. They analyzed the area up to approximately 200 feet from the perimeter of each water body and found a "significantly greater" number of methane hot spots around beaver ponds.

"We have these datasets that largely overlap, in space and mostly in time," Tape said. "It's kind of a simple design relying on a new tool."

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Exploring light neutron-rich nuclei: First observation of oxygen-28

The study of physical systems under extreme conditions offers valuable insights into their organization and structure. In nuclear physics, neutron-rich isotopes, especially the light ones with neutron-to-proton ratio significantly different from that of stable nuclei, provide stringent tests of modern nuclear structure theories. These isotopes exist as very short-lived resonances, decaying through spontaneous neutron emission.

Now, in a new study published in available in Nature, an international collaboration of researchers led by Yosuke Kondo, an Assistant Professor at the Department of Physics at Tokyo Institute of Technology, reports the first observation of two such isotopes -- oxygen-28 (28O) and oxygen-27 (27O) -- through their decay into oxygen-24 with four and three neutrons, respectively. The nucleus 28O, which consists of 8 protons and 20 neutrons (N), is of significant interest as it is expected to be one of the few 'doubly magic' nuclei in the standard shell-model picture of nuclear structure.

The study's success was enabled by the capabilities of the RIKEN RI Beam Factory, which could produce intense beams of unstable nuclei coupled to an active target of thick liquid hydrogen and multi-neutron detection arrays. Proton-induced nucleon knockout reactions from a high-energy 29F beam generated the neutron-unbound isotopes 27O and 28O. The researchers observed these isotopes and studied their properties by directly detecting their decay products.

They found that both 27O and 28O exist as narrow low-lying resonances and compared their decay energies to the results of sophisticated theoretical models -- a large-scale shell model calculation and a newly developed statistical approach -- based on effective field theories of quantum chromodynamics. Most theoretical approaches predicted higher energies for both isotopes. "Specifically, the statistical coupled-cluster calculations suggested that the energies of 27O and 28O can provide valuable constraints for the interactions considered in such ab initio approaches," points out Dr. Kondo.

"The researchers also investigated the cross-section for the production of 28O from the 29F beam, finding it to be consistent with 28O not exhibiting a closed N = 20 shell structure. "This result suggests that the 'island of inversion,' whereby the energy gap between neutron orbitals weakens or vanishes, extends beyond the fluorine isotopes 28F and 29F into the oxygen isotopes," explains Dr. Kondo.

The present findings enhance our understanding of nuclear structure by offering new insights, especially for extremely neutron-rich nuclei. In addition, the detailed investigation of multi-neutron correlations and the study of other exotic systems now become possible with the multi-neutron-decay spectroscopy technique utilized here.

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Life on Earth didn't arise as described in textbooks

No, oxygen didn't catalyze the swift blossoming of Earth's first multicellular organisms. The result defies a 70-year-old assumption about what caused an explosion of oceanic fauna hundreds of millions of years ago.

Between 685 and 800 million years ago, multicellular organisms began to appear in all of Earth's oceans during what's known as the Avalon explosion, a forerunner era of the more famed Cambrian explosion. During this era, sea sponges and other bizarre multicellular organisms replaced small single-celled amoeba, algae and bacteria, which until then, had had run of the planet for more than 2 billion years.

Up until now, it was believed that increased oxygen levels triggered the evolutionary arrival of more advanced marine organisms. This is being disproved by University of Copenhagen researchers working together with colleagues from Woods Hole Oceanographic Institute, the University of Southern Denmark and Lund University, among others.

By studying the chemical composition of ancient rock samples from an Omani mountain range, the researchers have been able to "measure" oxygen concentrations in the world's oceans from when these multicellular organisms appeared. Defying expectations, the result shows that Earth's oxygen concentrations had not increased. Indeed, levels remained 5-10 times lower than today, which is roughly how much oxygen there is at twice the height of Mount Everest.

"Our measurements provide a good picture of what average oxygen concentrations were in the world's oceans at the time. And it's apparent to us that there was no major increase in the amount of oxygen when more advanced fauna began to evolve and dominate Earth. In fact, there was somewhat of a slight decrease," says Associate Professor Christian J. Bjerrum, who has been quantifying the conditions surrounding the origin of life for the past 20 years.

Revises our understanding of life's origins

The new result puts to rest a 70-year research story that advances the centrality of higher oxygen concentrations in the development of more advanced life on our planet.

"The fact that we now know, with a high degree of certainty, that oxygen didn't control the development of life on Earth provides us with an entirely new story about how life arose and what factors controlled this success," says the researcher, adding:

"Specifically, it means that we need to rethink a lot of the things that we believed to be true from our childhood learning. And textbooks need to be revised and rewritten."

There remains much that the researchers don't know, as well as and a plethora of controversy. Therefore, Bjerrum hopes that the new result can spur other researchers around the world to reconsider their previous results and data in a new light.

"There are many research sections around the world, including in the United States and China, that have done lots of research on this topic, whose earlier results may shed important new details if interpreted on the basis that oxygen didn't drive the development of life," says the researcher.

Absence of oxygen may have aided development

So, if not extra oxygen, what triggered the era's explosion of life? Perhaps the exact opposite, explains the researcher:

"It's interesting that the explosion of multicellular organisms occurs at a time with low concentrations of atmospheric and oceanic oxygen. That indicates that organisms benefited from lower levels of oxygen and were able to develop in peace, as the water chemistry protected their stem cells naturally," says Christian J. Bjerrum.

According to the researcher, the same phenomenon has been studied in cancer research, in the stem cells of humans and other animals. Here, colleagues at Lund University observed that low oxygen levels are crucial for keeping stem cells under control until an organism decides that the cell ought to develop into a specific type of cell, such as a muscle cell.

"We know that animals and humans must be able to maintain low concentrations of oxygen in order to control their stem cells, and in so doing, develop slowly and sustainably. With too much oxygen, the cells will develop, and in the worst case, mutate wildly and perish. It is far from inconceivable that this mechanism applied back then," concludes Christian J. Bjerrum.

Fossils from Oman

In the new study, the researchers analysed rock samples from, among other places, the Oman Mountains in northern Oman. While quite high and very dry today, the mountains were on the seabed during the Avalon explosion's rapid blossoming of organism diversity.

The researchers have had their findings confirmed in fossils from three different mountain ranges around the world: the Oman Mountains (Oman), Mackenzie Mountains (NW Canada) and the Yangtze Gorges area of South China.

Over time, clay and sand from land are washed into the sea, where they settle into layers on the seabed. By going down through these layers and examining their chemical composition, researchers can get a picture of ocean chemistry at a particular geologic time.

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Remains of an extinct world of organisms discovered

Newly discovered biomarker signatures point to a whole range of previously unknown organisms that dominated complex life on Earth about a billion years ago. They differed from complex eukaryotic life as we know it, such as animals, plants and algae in their cell structure and likely metabolism, which was adapted to a world that had far less oxygen in the atmosphere than today. An international team of researchers, including GFZ geochemist Christian Hallmann, now reports on this breakthrough for the field of evolutionary geobiology in the journal Nature.

The previously unknown "protosteroids" were shown to be surprisingly abundant throughout Earth´s Middle Ages. The primordial molecules were produced at an earlier stage of eukaryotic complexity -- extending the current record of fossil steroids beyond 800 and up to 1,600 million years ago. Eukaryotes is the term for a kingdom of life including all animals, plants and algae and set apart from bacteria by having a complex cell structure that includes a nucleus, as well as a more complex molecular machinery. "The highlight of this finding is not just the extension of the current molecular record of eukaryotes," Hallmann says: "Given that the last common ancestor of all modern eukaryotes, including us humans, was likely capable of producing 'regular' modern sterols, chances are high that the eukaryotes responsible for these rare signatures belonged to the stem of the phylogenetic tree."

Unprecedented glimpse of a lost world

This "stem" represents the common ancestral lineage that was a precursor to all still living branches of eukaryotes. Its representatives are long extinct, yet details of their nature may shed more light on the conditions surrounding the evolution of complex life. Although more research is needed to evaluate what percentage of protosteroids may have had a rare bacterial source, the discovery of these new molecules not only reconciles the geological record of traditional fossils with that of fossil lipid molecules, but yields a rare and unprecedented glimpse of a lost world of ancient life. The competitive demise of stem group eukaryotes, marked by the first appearance of modern fossil steroids some 800 Million years ago, may reflect one of the most incisive events in the evolution of increasingly complex life.

"Almost all eukaryotes biosynthesise steroids, such as cholesterol that is produced by humans and most other animals" adds Benjamin Nettersheim from the University of Bremen, first author of the study -- "due to potentially adverse health effects of elevated cholesterol levels in humans, cholesterol doesn't have the best reputation from a medical perspective. However, these lipid molecules are integral parts of eukaryotic cell membranes where they aid in a variety of physiological functions. By searching for fossilised steroids in ancient rocks, we can trace the evolution of increasingly complex life."

What the Nobel laureate thaught impossible...

Nobel laureate Konrad Bloch had already speculated about such a biomarker in an essay almost 30 years ago. Bloch suggested that short-lived intermediates in the modern biosynthesis of steroids may not always have been intermediates. He believed that lipid biosynthesis evolved in parallel with changing environmental conditions throughout Earth history. In contrast to Bloch, who did not believe that these ancient intermediates could ever be found, Nettersheim started searching for protosteroids in ancient rocks that were deposited at a time when those intermediates could actually have been the final product.

But how to find such molecules in ancient rocks? "We employed a combination of techniques to first convert various modern steroids to their fossilised equivalent; otherwise we wouldn't have even known what to look for," says Jochen Brocks, professor at the Australian National University who shares the first-authorship of the new study with Nettersheim. Scientists had overlooked these molecules for decades because they do not conform to typical molecular search images. "Once we knew our target, we discovered that dozens of other rocks, taken from billion-year-old waterways across the world, were oozing with similar fossil molecules."

The oldest samples with the biomarker are from the Barney Creek Formation in Australia and are 1.64 billion years old. The rock record of the next 800 Million years only yields fossil molecules of primordial eukaryotes before molecular signatures of modern eukaryotes first appear in the Tonian period. According to Nettersheim "the Tonian Transformation emerges as one of the most profound ecological turning points in our planet's history." Hallmann adds that "both primordial stem groups and modern eukaryotic representatives such as red algae may have lived side by side for many hundreds of millions of years." During this time, however, the Earth's atmosphere became increasingly enriched with oxygen -- a metabolic product of cyanobacteria and of the first eukaryotic algae that would have been toxic to many other organisms. Later, global "Snowball Earth" glaciations occurred and the protosterol communities largely died out. The last common ancestor of all living eukaryotes may have lived 1.2 to 1.8 billion years ago. Its descendants were likely better able to survive heat and cold as well as UV radiation and displaced their primordial relatives.

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Humans need Earth-like ecosystem for deep-space living

Can humans endure long-term living in deep space? The answer is a lukewarm maybe, according to a new theory describing the complexity of maintaining gravity and oxygen, obtaining water, developing agriculture and handling waste far from Earth.

Dubbed the Pancosmorio theory -- a word coined to mean "all world limit" -- it was described in a paper published in Frontiers in Astronomy and Space Sciences.

"For humans to sustain themselves and all of their technology, infrastructure and society in space, they need a self-restoring, Earth-like, natural ecosystem to back them up," said co-author Morgan Irons, a doctoral student conducting research with Johannes Lehmann, professor in the School of Integrative Plant Science at Cornell University. Her work focuses on soil organic carbon persistence under Earth's gravity and varying gravity conditions. "Without these kinds of systems, the mission fails."

The first key is gravity, which Earth life needs to function properly, said co-author Lee Irons, Morgan Irons' father and executive director of the Norfolk Institute, a group that aims to solve problems of human resilience on Earth and in space.

"Gravity induces a gradient in the fluid pressure within the body of the living thing to which the autonomic functions of the life form are attuned," he said. "An example of gravity imbalance would be the negative affect on the eyesight of humans in Earth orbit, where they don't experience the weight necessary to induce the pressure gradient."

Morgan Irons said that it would be unwise to spend billions of dollars to set up a space settlement only to see it fail, because even with all other systems in place, you need gravity.

Humans and all Earth life have evolved within the context of 1G of gravity. "Our bodies, our natural ecosystems, all the energy movement and the way we utilize energy is all fundamentally based upon 1G of gravity being present," she said. "There is just no other place in space where there is 1G of gravity; that just doesn't exist anywhere else in our solar system. That's one of the first problems we must solve."

Oxygen is another key factor. Earth's ecosystem generates oxygen for humans and other life forms. If a technologically advanced primary and a back-up system failed to provide oxygen for the moon base, for example, it would mean instant doom for the astronauts. "A reserve exists everywhere in Earth's nature," Lee Irons said. "Think of the hundreds of thousands of species of plants that generate oxygen. That's the kind of system reserve we need to replicate to be truly sustainable."

Such an ecological system of an outpost would need an enormous amount energy from the sun. The more distant planets and moons from the sun in our own solar system get decreased amounts of energy.

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Does ice in the Universe contain the molecules making up the building blocks of life in planetary systems?

The James Webb Space Telescope -- the most precise telescope ever built -- was decisive in discovering the frozen forms of a long series of molecules, such as carbon dioxide, ammonia, methane, methanol and even more complex molecules, frozen out as ices on the surface of small dust grains.

The dust grains grow in size when being a part of the discs of gas and dust forming around young stars. This means that the researchers could study many of the molecules going into the forming of new exoplanets.

Researchers at the Niels Bohr Institute, University of Copenhagen, combined the discoveries from JWST with data from Atacama Large Millimeter Array (ALMA), making observations in other wavelengths than JWST and researchers from Aarhus University contributed with the necessary investigations in the laboratory.

"With the application of observations, e.g. from ALMA, it is possible for us to directly observe the dust grains themselves, and it is also possible to see the same molecules as in the gas observed in the ice" Lars Kristensen, associate Professor at the Niels Bohr Institute (NBI), explains.

"Using the combined data set gives us a unique insight into the complex interactions between gas, ice and dust in areas where stars and planets form" according to Jes Jørgensen, Professor at NBI.

"This way we can map the location of the molecules in the area both before and after they have been frozen out onto the dust grains and we can follow their path from the cold molecular cloud to the emerging planetary systems around young stars."

The content of ice in the molecular cloud was a decisive discovery

The ices were detected and measured by studying how starlight from beyond the molecular cloud was absorbed by icy molecules at specific infrared wavelengths visible to Webb.

This process leaves behind chemical fingerprints known as absorption spectra which can be compared with laboratory data to identify which ices are present in the molecular cloud.

In this study, the team targeted ices buried in a particularly cold, dense and difficult to investigate region of the Chamaeleon I molecular cloud, a region approximately 600 light-years from Earth which is currently in the process of forming dozens of young stars.

Along with star forming comes planet forming and the perspective for the researchers in the IceAge collaboration is basically to identify the role the ice plays in gathering the molecules necessary to form life.

"This study confirms that interstellar grains of dust are catalysts for the forming of complex molecules in the very diffuse gas in these clouds, something we see in the lab as well," Sergio Ioppolo explains, associate professor at Aarhus University, contributing with some of the experiments in the lab that were compared with the observations.

The sensitivity of JWST was an absolutely necessary precondition for the discovery

"We simply couldn't have observed these ices without Webb," elaborated Klaus Pontoppidan, JWST project scientist at the Space Telescope Science Institute, Baltimore, USA, who was involved in this research.

"The ices show up as dips against a continuum of background starlight. In regions that are this cold and dense, much of the light from the background star is blocked and Webb's exquisite sensitivity was necessary to detect the starlight and therefore identify the ices in the molecular cloud."

The IceAge team has already planned more observations with both Webb and other telescopes.

"These observations together with further laboratory studies will tell us which mixture of ices -- and therefore which elements -- can eventually be delivered to the surfaces of terrestrial exoplanets or incorporated into the atmospheres of giant gas or ice planets.

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Seawater split to produce 'green' hydrogen

Researchers have successfully split seawater without pre-treatment to produce green hydrogen.

The international team was led by the University of Adelaide's Professor Shizhang Qiao and Associate Professor Yao Zheng from the School of Chemical Engineering.

"We have split natural seawater into oxygen and hydrogen with nearly 100 per cent efficiency, to produce green hydrogen by electrolysis, using a non-precious and cheap catalyst in a commercial electrolyser," said Professor Qiao.

A typical non-precious catalyst is cobalt oxide with chromium oxide on its surface.

"We used seawater as a feedstock without the need for any pre-treatment processes like reverse osmosis desolation, purification, or alkalisation," said Associate Professor Zheng.

"The performance of a commercial electrolyser with our catalysts running in seawater is close to the performance of platinum/iridium catalysts running in a feedstock of highly purified deionised water.

The team published their research in the journal Nature Energy.

"Current electrolysers are operated with highly purified water electrolyte. Increased demand for hydrogen to partially or totally replace energy generated by fossil fuels will significantly increase scarcity of increasingly limited freshwater resources," said Associate Professor Zheng.

Seawater is an almost infinite resource and is considered a natural feedstock electrolyte. This is more practical for regions with long coastlines and abundant sunlight. However, it isn't practical for regions where seawater is scarce.

Seawater electrolysis is still in early development compared with pure water electrolysis because of electrode side reactions, and corrosion arising from the complexities of using seawater.

"It is always necessary to treat impure water to a level of water purity for conventional electrolysers including desalination and deionisation, which increases the operation and maintenance cost of the processes," said Associate Professor Zheng.

"Our work provides a solution to directly utilise seawater without pre-treatment systems and alkali addition, which shows similar performance as that of existing metal-based mature pure water electrolyser."

The team will work on scaling up the system by using a larger electrolyser so that it can be used in commercial processes such as hydrogen generation for fuel cells and ammonia synthesis.

Researchers have successfully split seawater without pre-treatment to produce green hydrogen.

The international team was led by the University of Adelaide's Professor Shizhang Qiao and Associate Professor Yao Zheng from the School of Chemical Engineering.

"We have split natural seawater into oxygen and hydrogen with nearly 100 per cent efficiency, to produce green hydrogen by electrolysis, using a non-precious and cheap catalyst in a commercial electrolyser," said Professor Qiao.

A typical non-precious catalyst is cobalt oxide with chromium oxide on its surface.

"We used seawater as a feedstock without the need for any pre-treatment processes like reverse osmosis desolation, purification, or alkalisation," said Associate Professor Zheng.

"The performance of a commercial electrolyser with our catalysts running in seawater is close to the performance of platinum/iridium catalysts running in a feedstock of highly purified deionised water.

The team published their research in the journal Nature Energy.

"Current electrolysers are operated with highly purified water electrolyte. Increased demand for hydrogen to partially or totally replace energy generated by fossil fuels will significantly increase scarcity of increasingly limited freshwater resources," said Associate Professor Zheng.

Seawater is an almost infinite resource and is considered a natural feedstock electrolyte. This is more practical for regions with long coastlines and abundant sunlight. However, it isn't practical for regions where seawater is scarce.

Seawater electrolysis is still in early development compared with pure water electrolysis because of electrode side reactions, and corrosion arising from the complexities of using seawater.

"It is always necessary to treat impure water to a level of water purity for conventional electrolysers including desalination and deionisation, which increases the operation and maintenance cost of the processes," said Associate Professor Zheng.

"Our work provides a solution to directly utilise seawater without pre-treatment systems and alkali addition, which shows similar performance as that of existing metal-based mature pure water electrolyser."

Read more at Science Daily

Geobiologists shine new light on Earth's first known mass extinction event 550 million years ago

A new study by Virginia Tech geobiologists traces the cause of the first known mass extinction of animals to decreased global oxygen availability, leading to the loss of a majority of animals present near the end of the Ediacaran Period some 550 million years ago.

The research spearheaded by Scott Evans, a postdoctoral researcher in the Department of Geosciences, part of the Virginia Tech College of Science, shows this earliest mass extinction of about 80 percent of animals across this interval. "This included the loss of many different types of animals, however those whose body plans and behaviors indicate that they relied on significant amounts of oxygen seem to have been hit particularly hard," Evans said. "This suggests that the extinction event was environmentally controlled, as are all other mass extinctions in the geologic record."

Evans' work was published Nov. 7 in the Proceedings of the National Academy of Sciences, a peer-reviewed journal of the National Academy of Sciences. The study was co-authored by Shuhai Xiao, also a professor in the Department of Geosciences, and several researchers led by Mary Droser from the University of California Riverside's Department of Earth and Planetary Sciences, where Evans earned his master's degree and Ph.D.

"Environmental changes, such as global warming and deoxygenation events, can lead to massive extinction of animals and profound disruption and reorganization of the ecosystem," said Xiao, who is an affiliated member of the Global Change Center, part of the Virginia Tech Fralin Life Sciences Institute. "This has been demonstrated repeatedly in the study of Earth history, including this work on the first extinction documented in the fossil record. This study thus informs us about the long-term impact of current environmental changes on the biosphere."

What exactly caused the drop in global oxygen? That's still up for debate. "The short answer to how this happened is we don't really know," Evans said. "It could be any number and combination of volcanic eruptions, tectonic plate motion, an asteroid impact, etc., but what we see is that the animals that go extinct seem to be responding to decreased global oxygen availability."

The study by Evans and Xiao is timelier than one would think. In an unconnected study, Virginia Tech scientists recently found that anoxia, the loss of oxygen availability, is affecting the world's fresh waters. The cause? The warming of waters brought on by climate change and excess pollutant runoff from land use. Warming waters diminish fresh water's capacity to hold oxygen, while the breakdown of nutrients in runoff by freshwater microbes gobbles up oxygen.

"Our study shows that, as with all other mass extinctions in Earth's past, this new, first mass extinction of animals was caused by major climate change -- another in a long list of cautionary tales demonstrating the dangers of our current climate crisis for animal life," said Evans, who is an Agouron Institute Geobiology fellow.

Some perspective: The Ediacaran Period spanned roughly 96 million years, bookended on either side by the end of Cryogenian Period -- 635 million years ago -- and the beginning of the Cambrian Period -- 539 million years ago. The extinction event comes just before a significant break in the geologic record, from the Proterozoic Eon to the Phanerozoic Eon.

There are five known mass extinctions that stand out in the history of animals, the "Big Five," according to Xiao, including the Ordovician-Silurian Extinction (440 million years ago), the late Devonian Extinction (370 million years ago), the Permian-Triassic Extinction (250 million years ago), the Triassic-Jurassic Extinction (200 million years ago), and the Cretaceous-Paleogene Extinction (65 million years ago).

"Mass extinctions are well recognized as significant steps in the evolutionary trajectory of life on this planet," Evans and team wrote in the study. Whatever the instigating cause of the mass extinction, the result was multiple major shifts in environmental conditions. "Particularly, we find support for decreased global oxygen availability as the mechanism responsible for this extinction. This suggests that abiotic controls have had significant impacts on diversity patterns throughout the more than 570 million-year history of animals on this planet," the authors wrote.

Fossil imprints in rock tell researchers how the creatures that perished in this extinction event would have looked. And they looked, in Evans' words, "weird."

"These organisms occur so early in the evolutionary history of animals that in many cases they appear to be experimenting with different ways to build large, sometimes mobile, multicellular bodies," Evans said. "There are lots of ways to recreate how they look, but the take-home is that before this extinction the fossils we find don't often fit nicely into the ways we classify animals today. Essentially, this extinction may have helped pave the way for the evolution of animals as we know them."

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Ceramics that breathe oxygen at lower temperatures help us breathe cleaner air

Although much of the discourse on reducing vehicle emissions centres on electric vehicles (EV), their sales remain low -- with EV vehicles accounting for a mere 1% of car purchases in Japan in 2021. Meanwhile, the European Union is expected to pass stricter emission standards in the near future. This makes improving the performance and functionality of exhaust gas purification catalysts in petrol or diesel-powered vehicles a critical component in the push towards carbon neutrality.

Nearly all petrol or diesel cars are equipped with catalytic converters that remove harmful hydrocarbons, carbon monoxide and nitrogen oxide and convert them into safer gases such as nitrogen, carbon dioxide and water vapor. The toxic gases flow through a honeycomb structure, coated with exhaust gas purifying catalysts.

Ceramics with an oxygen storage capacity (OSC) play a crucial role in the purification process. They help remove noxious gases and prevent the precious metals in catalytic converters from coarsening, which degrades their purification capabilities.

To improve their potential, however, a lower operating temperature is required. But scientists have struggled to achieve this since reducing the temperature to less than 500 ºC results in slower ion diffusion.

Now, a research group at Tohoku University's Graduate School of Engineering has developed a Cerium-Zirconium-based (Ce-Zr) oxide with excellent OSC at 400 ºC by controlling its crystal structure. The OSC at 400 ºC was higher than conventional materials by a factor of 13.5, even without precious metal catalysts.

"The key to our success was introducing a tiny amount of transition metals, such as iron, to the Ce-Zr-based oxides," said Professor Hitoshi Takamura, leader of the research group.

The 'transition metal doping' had two notable effects in the oxides. It accelerated the oxygen diffusion by easing the formation of oxygen vacancies and promoted cation ordering.

"Cation ordering tidies up the crystal structure and makes oxygen readily released," explained Takamura.

The iron doping reduced the cation-ordering temperature, which in turn enabled a larger surface area for the Ce-Zr-based oxides. This enhanced their durability and ability to purify toxic gases.

In the future, Takamura and his group hope to test the material by loading it with palladium on honeycomb supports.

Read more at Science Daily

Back to the future of photosynthesis

The central biocatalyst in photosynthesis, Rubisco, is the most abundant enzyme on earth. By reconstructing billion-year-old enzymes, a team of Max Planck researchers has deciphered one of the key adaptations of early photosynthesis. Their results not only provide insights into the evolution of modern photosynthesis but also offer new impulses for improving it.

Present day life fully depends on photosynthetic organisms like plants and algae that capture and convert CO2. At the heart of these processes lies an enzyme called Rubisco that captures more than 400 billion tons CO2 annually. Organisms alive today make staggering amounts of it: the mass of Rubisco on our planet outweighs that of all humans. In order to assume such a dominant role in the global carbon cycle, Rubisco had to adapt constantly to changing environmental conditions.

Using a combination of computational and synthetic approaches, a team from the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany, in collaboration with the University of Singapore has now successfully resurrected and studied billion-year-old enzymes in the lab. In this process, which they describe as "molecular paleontology," the researchers found that instead of direct mutations in the active center, an entirely new component prepared photosynthesis to adapt to rising oxygen levels.

Rubisco's early confusion

Rubisco is ancient: it emerged approximately four billion years ago in primordial metabolism prior to the presence of oxygen on earth. However, with the invention of oxygen-producing photosynthesis and rise of oxygen in the atmosphere, the enzyme started catalyzing an undesired reaction, in which it mistakes O2 for CO2 and produces metabolites that are toxic to the cell. This confused substrate scope still scars Rubiscos to date and limits photosynthetic efficiency. Even though Rubiscos that evolved in oxygen-containing environments became more specific for CO2 over time, none of them could get completely rid of the oxygen capturing reaction.

The molecular determinants of increased CO2 specificity in Rubisco remain largely unknown. However, they are of great interest to researchers aiming to improve photosynthesis. Interestingly, those Rubiscos that show increased CO2 specificity recruited a novel protein component of unknown function. This component was suspected to be involved in increasing CO2 specificity, however, the true reason for its emergence remained difficult to determine because it already evolved billions of years ago.

Studying evolution by resurrecting ancient proteins in the lab

To understand this key event in the evolution of more specific Rubiscos, collaborators at the Max Planck Institute for Terrestrial Microbiology in Marburg and Nanyang Technological University in Singapore used a statistical algorithm to recreate forms of Rubiscos that existed billions of years ago, before oxygen levels began to rise. The team led by Max Planck researchers Tobias Erb and Georg Hochberg resurrected these ancient proteins in the lab to study their properties. In particular, the scientists wondered whether Rubisco's new component had anything to do with the evolution of higher specificity.

The answer was surprising, as doctoral researcher Luca Schulz explains: "We expected the new component to somehow directly exclude oxygen from Rubisco catalytic center. That is not what happened. Instead, this new subunit seems to act as a modulator for evolution: recruitment of the subunit changed the effect that subsequent mutations had on Rubisco's catalytic subunit. Previously inconsequential mutations suddenly had a huge effect on specificity when this new component was present. It seems that having this new subunit completely changed Rubisco's evolutionary potential."

An enzyme's addiction to its new subunit

This function as an "evolutionary modulator" also explains another mysterious aspect of the new protein component: Rubiscos that incorporated it are completely dependent on it, even though other forms of Rubisco can function perfectly well without. The same modulating effect explains why: When bound to this small protein component, Rubisco become tolerant to mutations that would otherwise be catastrophically detrimental. With the accumulation of such mutations, Rubisco effectively became addicted to its new subunit.

Altogether, the findings finally explain the reason why Rubisco kept this new protein component around ever since it encountered it. Max Planck Research Group Leader Georg Hochberg explains: "The fact that this connection was not understood until now highlights the importance of evolutionary analysis for understanding the biochemistry that drives life around us. The history of biomolecules like Rubisco can teach us so much about why they are the way they are today. And there are still so many biochemical phenomena whose evolutionary history we really have no idea about. So it's a very exciting time to be an evolutionary biochemist: almost the entire molecular history of the cell is still waiting to be discovered."

Read more at Science Daily

MOXIE experiment reliably produces oxygen on Mars

On the red and dusty surface of Mars, nearly 100 million miles from Earth, an instrument the size of a lunchbox is proving it can reliably do the work of a small tree.

The MIT-led Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE, has been successfully making oxygen from the Red Planet's carbon-dioxide-rich atmosphere since February 2021, when it touched down on the Martian surface as part of NASA's Perseverance rover mission.

In a study published in the journal Science Advances, researchers report that, by the end of 2021, MOXIE was able to produce oxygen on seven experimental runs, in a variety of atmospheric conditions, including during the day and night, and through different Martian seasons. In each run, the instrument reached its target of producing six grams of oxygen per hour -- about the rate of a modest tree on Earth.

Researchers envision that a scaled-up version of MOXIE could be sent to Mars ahead of a human mission, to continuously produce oxygen at the rate of several hundred trees. At that capacity, the system should generate enough oxygen to both sustain humans once they arrive, and fuel a rocket for returning astronauts back to Earth.

So far, MOXIE's steady output is a promising first step toward that goal.

"We have learned a tremendous amount that will inform future systems at a larger scale," says Michael Hecht, principal investigator of the MOXIE mission at MIT's Haystack Observatory.

MOXIE's oxygen production on Mars also represents the first demonstration of "in-situ resource utilization," which is the idea of harvesting and using a planet's materials (in this case, carbon dioxide on Mars) to make resources (such as oxygen) that would otherwise have to be transported from Earth.

"This is the first demonstration of actually using resources on the surface of another planetary body, and transforming them chemically into something that would be useful for a human mission," says MOXIE deputy principal investigator Jeffrey Hoffman, a professor of the practice in MIT's Department of Aeronautics and Astronautics. "It's historic in that sense."

Hoffman and Hecht's MIT co-authors include MOXIE team members Jason SooHoo, Andrew Liu, Eric Hinterman, Maya Nasr, Shravan Hariharan, and Kyle Horn, along with collaborators from multiple institutions including NASA's Jet Propulsion Laboratory, which managed MOXIE's development, flight software, packaging, and testing prior to launch.

Seasonal air

The current version of MOXIE is small by design, in order to fit aboard the Perseverance rover, and is built to run for short periods, starting up and shutting down with each run, depending on the rover's exploration schedule and mission responsibilities. In contrast, a full-scale oxygen factory would include larger units that would ideally run continuously.

Despite the necessary compromises in MOXIE's current design, the instrument has shown it can reliably and efficiently convert Mars' atmosphere into pure oxygen. It does so by first drawing the Martian air in through a filter that cleans it of contaminants. The air is then pressurized, and sent through the Solid OXide Electrolyzer (SOXE), an instrument developed and built by OxEon Energy, that electrochemically splits the carbon dioxide-rich air into oxygen ions and carbon monoxide.

The oxygen ions are then isolated and recombined to form breathable, molecular oxygen, or O2, which MOXIE then measures for quantity and purity before releasing it harmlessly back into the air, along with carbon monoxide and other atmospheric gases.

Since the rover's landing in February 2021, MOXIE engineers have started up the instrument seven times throughout the Martian year, each time taking a few hours to warm up, then another hour to make oxygen before powering back down. Each run was scheduled for a different time of day or night, and in different seasons, to see whether MOXIE could accommodate shifts in the planet's atmospheric conditions.

"The atmosphere of Mars is far more variable than Earth," Hoffman notes. "The density of the air can vary by a factor of two through the year, and the temperature can vary by 100 degrees. One objective is to show we can run in all seasons."

So far, MOXIE has shown that it can make oxygen at almost any time of the Martian day and year.

"The only thing we have not demonstrated is running at dawn or dusk, when the temperature is changing substantially," Hecht says. "We do have an ace up our sleeve that will let us do that, and once we test that in the lab, we can reach that last milestone to show we can really run any time."

Ahead of the game

As MOXIE continues to churn out oxygen on Mars, engineers plan to push its capacity, and increase its production, particularly in the Martian spring, when atmospheric density and carbon dioxide levels are high.

"The next run coming up will be during the highest density of the year, and we just want to make as much oxygen as we can," Hecht says. "So we'll set everything as high as we dare, and let it run as long as we can."

They will also monitor the system for signs of wear and tear. As MOXIE is just one experiment among several aboard the Perseverance rover, it cannot run continuously as a full-scale system would. Instead, the instrument must start up and shut down with each run -- a thermal stress that can degrade the system over time.

If MOXIE can operate successfully despite repeatedly turning on and off, this would suggest that a full-scale system, designed to run continuously, could do so for thousands of hours.

Read more at Science Daily

The brain already benefits from moderate physical activity, study shows

Even moderate physical activity has a positive effect on the brain. DZNE researchers led by Dr. Dr. Ahmad Aziz deduce this from examinations of 2,550 participants of the Bonn "Rhineland Study." According to their findings, certain areas of the brain are larger in physically active individuals than in those who are less active. In particular, brain regions that have a relatively high oxygen demand benefit from this effect. The research results are published in Neurology®, the medical journal of the American Academy of Neurology.

Exercise keeps body and mind healthy -- but little is known about exactly how and where physical activity affects our brains. "In previous research, the brain was usually considered as a whole," says Fabienne Fox, neuroscientist and lead author of the current study. "Our goal was to take a more detailed look at the brain and find out which regions of the brain physical activity impacts most."

Extensive Data from the Rhineland study

For their research, Fox and colleagues used data from the Rhineland Study, a large-scale population-based study conducted by DZNE in the Bonn city area. Specifically, they analyzed physical activity data from 2,550 volunteers aged 30 to 94 years, as well as brain images obtained by magnetic resonance imaging (MRI). To sample physical activity, the study participants wore an accelerometer on their upper thigh for seven days. The MRI scans provided information particularly on brain volume and thickness of the cortex.

The More Active, the Greater the Effects

"We were able to show that physical activity had a noticeable effect on almost all brain regions investigated. Generally, we can say that the higher and more intense the physical activity, the larger the brain regions were, either with regard to volume or cortical thickness," Fabienne Fox summarizes the research results. "In particular, we observed this in the hippocampus, which is considered the control center of memory. Larger brain volumes provide better protection against neurodegeneration than smaller ones." However, the dimensions of the brain regions do not increase linearly with physical activity. The research team found the largest, almost sudden volume increase when comparing inactive and only moderately physically active study participants -- this was particularly evident in older individuals over the age of 70.

"In principle, this is very good news -- especially for those who are reluctant to exercise," says Ahmad Aziz, who heads the research group "Population and Clinical Neuroepidemiology" at DZNE. "Our study results indicate that even small behavioral changes, such as walking 15 minutes a day or taking the stairs instead of the elevator, may have a substantial positive effect on the brain and potentially counteract age-related loss of brain matter and the development of neurodegenerative diseases. In particular, older adults can already profit from modest increases of low intensity physical activity."

Young and somewhat athletic subjects who usually engaged in moderate to intense physical activity also had relatively high brain volumes. However, in even more active subjects, these brain regions were slightly larger. Also here it showed: the more active, the greater the effect, although at high levels of physical activity, the beneficial effects tended to level off.

Brain Regions that Benefit the Most

To characterize the brain regions that benefited most from physical activity, the research team searched databases for genes that are particularly active in these brain areas. "Mainly, these were genes that are essential for the functioning of mitochondria, the power plants of our cells," says Fabienne Fox. This means that there are particularly large numbers of mitochondria in these brain regions. Mitochondria provide our body with energy, for which they need a lot of oxygen. "Compared to other brain regions, this requires increased blood flow. This is ensured particularly well during physical activity, which could explain why these brain regions benefit from exercise," says Ahmad Aziz.

Exercise Protects

The bioinformatic analysis further showed that there is a large overlap between genes whose expression is affected by physical activity and those that are impacted by neurodegenerative diseases such as Alzheimer's, Parkinson's, or Huntington's disease. This could offer a potential explanation for why physical activity has a neuroprotective effect, the research team concludes. "With our study, we were able to characterize brain regions that benefit from physical activity to an unprecedented level of detail," says Ahmad Aziz. "We hope our results will provide important leads for further research."

Read more at Science Daily

Technology restores cell, organ function in pigs after death

Within minutes of the final heartbeat, a cascade of biochemical events triggered by a lack of blood flow, oxygen, and nutrients begins to destroy a body's cells and organs. But a team of Yale scientists has found that massive and permanent cellular failure doesn't have to happen so quickly.

Using a new technology they developed that delivers a specially designed cell-protective fluid to organs and tissues, the researchers restored blood circulation and other cellular functions in pigs a full hour after their deaths, they report in the Aug. 3 edition of the journal Nature.

The findings may help extend the health of human organs during surgery and expand availability of donor organs, the authors said.

"All cells do not die immediately, there is a more protracted series of events," said David Andrijevic, associate research scientist in neuroscience at Yale School of Medicine and co-lead author of the study. "It is a process in which you can intervene, stop, and restore some cellular function."

The research builds upon an earlier Yale-led project that restored circulation and certain cellular functions in the brain of a dead pig with technology dubbed BrainEx. Published in 2019, that study and the new one were led by the lab of Yale's Nenad Sestan, the Harvey and Kate Cushing Professor of Neuroscience and professor of comparative medicine, genetics, and psychiatry.

"If we were able to restore certain cellular functions in the dead brain, an organ known to be most susceptible to ischemia [inadequate blood supply], we hypothesized that something similar could also be achieved in other vital transplantable organs," Sestan said.

In the new study -- which involved senior author Sestan and colleagues Andrijevic, Zvonimir Vrselja, Taras Lysyy, and Shupei Zhang, all from Yale -- the researchers applied a modified version of BrainEx called OrganEx to the whole pig. The technology consists of a perfusion device similar to heart-lung machines -- which do the work of the heart and lungs during surgery -- and an experimental fluid containing compounds that can promote cellular health and suppress inflammation throughout the pig's body. Cardiac arrest was induced in anesthetized pigs, which were treated with OrganEx an hour after death.

Six hours after treatment with OrganEx, the scientists found that certain key cellular functions were active in many areas of the pigs' bodies -- including in the heart, liver, and kidneys -- and that some organ function had been restored. For instance, they found evidence of electrical activity in the heart, which retained the ability to contract.

"We were also able to restore circulation throughout the body, which amazed us," Sestan said.

Normally when the heart stops beating, organs begin to swell, collapsing blood vessels and blocking circulation, he said. Yet circulation was restored and organs in the deceased pigs that received OrganEx treatment appeared functional at the level of cells and tissue.

"Under the microscope, it was difficult to tell the difference between a healthy organ and one which had been treated with OrganEx technology after death," Vrselja said.

As in the 2019 experiment, the researchers also found that cellular activity in some areas of the brain had been restored, though no organized electrical activity that would indicate consciousness was detected during any part of the experiment.

The team was especially surprised to observe involuntary and spontaneous muscular movements in the head and neck areas when they evaluated the treated animals, which remained anesthetized through the entire six-hour experiment. These movements indicate the preservation of some motor functions, Sestan said.

The researchers stressed that additional studies are necessary to understand the apparently restored motor functions in the animals, and that rigorous ethical review from other scientists and bioethicists is required.

The experimental protocols for the latest study were approved by Yale's Institutional Animal Care and Use Committee and guided by an external advisory and ethics committee.

The OrganEx technology could eventually have several potential applications, the authors said. For instance, it could extend the life of organs in human patients and expand the availability of donor organs for transplant. It might also be able to help treat organs or tissue damaged by ischemia during heart attacks or strokes.

"There are numerous potential applications of this exciting new technology," said Stephen Latham, director of the Yale Interdisciplinary Center for Bioethics. "However, we need to maintain careful oversight of all future studies, particularly any that include perfusion of the brain."

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Martian meteorite upsets planet formation theory

A new study of an old meteorite contradicts current thinking about how rocky planets like the Earth and Mars acquire volatile elements such as hydrogen, carbon, oxygen, nitrogen and noble gases as they form. The work is published June 16 in Science.

A basic assumption about planet formation is that planets first collect these volatiles from the nebula around a young star, said Sandrine Péron, a postdoctoral scholar working with Professor Sujoy Mukhopadhyay in the Department of Earth and Planetary Sciences, University of California, Davis.

Because the planet is a ball of molten rock at this point, these elements initially dissolve into the magma ocean and then degass back into the atmosphere. Later on, chondritic meteorites crashing into the young planet deliver more volatile materials.

So scientists expect that the volatile elements in the interior of the planet should reflect the composition of the solar nebula, or a mixture of solar and meteoritic volatiles, while the volatiles in the atmosphere would come mostly from meteorites. These two sources -- solar vs. chondritic -- can be distinguished by the ratios of isotopes of noble gases, in particular krypton.

Mars is of special interest because it formed relatively quickly -- solidifying in about 4 million years after the birth of the Solar System, while the Earth took 50 to 100 million years to form.

"We can reconstruct the history of volatile delivery in the first few million years of the Solar System," Péron said.

Meteorite from Mars' interior

Some meteorites that fall to Earth come from Mars. Most come from surface rocks that have been exposed to Mars' atmosphere. The Chassigny meteorite, which fell to Earth in north-eastern France in 1815, is rare and unusual because it is thought to represent the interior of the planet.

By making extremely careful measurements of minute quantities of krypton isotopes in samples of the meteorite using a new method set up at the UC Davis Noble Gas Laboratory, the researchers could deduce the origin of elements in the rock.

"Because of their low abundance, krypton isotopes are challenging to measure," Péron said.

Surprisingly, the krypton isotopes in the meteorite correspond to those from chondritic meteorites, not the solar nebula. That means that meteorites were delivering volatile elements to the forming planet much earlier than previously thought, and in the presence of the nebula, reversing conventional thinking.

"The Martian interior composition for krypton is nearly purely chondritic, but the atmosphere is solar," Péron said. "It's very distinct."

The results show that Mars' atmosphere cannot have formed purely by outgassing from the mantle, as that would have given it a chondritic composition. The planet must have acquired atmosphere from the solar nebula, after the magma ocean cooled, to prevent substantial mixing between interior chondritic gases and atmospheric solar gases.

The new results suggest that Mars' growth was completed before the solar nebula was dissipated by radiation from the Sun. But the irradiation should also have blown off the nebular atmosphere on Mars, suggesting that atmospheric krypton must have somehow been preserved, possibly trapped underground or in polar ice caps.

"However, that would require Mars to have been cold in the immediate aftermath of its accretion," Mukhopadhyay said. "While our study clearly points to the chondritic gases in the Martian interior, it also raises some interesting questions about the origin and composition of Mars' early atmosphere."

Read more at Science Daily

Scaling new heights with new research showing how plants can grow at altitude

A new study has found that plant species are adapted to the altitude where they grow by 'sensing' the oxygen levels that surround them.

Altitude is an important part of plant ecology with at least 30% of plant species diversity contained in mountains and climate change is leading to the retreat of alpine species and some crops to higher altitudes.

Research led by scientists at the University of Nottingham has identified a mechanism through which plants can sense atmospheric oxygen levels (that decrease with altitude) that will help to understand how plants live at high altitude. The work was carried out in collaboration with scientists in Spain and Ecuador and was funded by the Leverhulme Trust. Their findings have been published today in Nature.

Researchers analysed plants growing at low and high-altitude locations. The team, working in Nottingham, Ecuador and Spain was able to identify how oxygen-sensing controls the pathway of chlorophyll synthesis, permitting plants to match the levels of a key toxic chemical to surrounding oxygen levels.

Climate change is leading to the displacement of wild species and crops (for example coffee) to higher altitudes, this research offers new insights into the underlying genetic mechanisms controlling their ability to survive at different altitudes. This new understanding of the genetic changes plants go through at altitude could lead to approaches to help plant breeders enhance the capacity of crops to grow at higher altitudes.

The research was led by Professor Michael Holdsworth from the University of Nottingham in collaboration with Professor Karina Proaño at ESPE University in Sangolquí, Ecuador and Professor Carlos Alonso Blanco from the Spanish National Centre for Biotechnology CSIC.

Professor Holdsworth commented: "Altitude is a key component of ecology with different altitudes subjecting plants to changing environments, some components of which are fixed by altitude and others that are not. For life at high altitude, it was previously considered that plants need to adapt to many variables, including high UV light and lower temperatures usually present at high altitude but this study is the first time that perception of atmospheric oxygen levels has been shown to be a key determinant of altitude adaptation in plants. "

He continues: "Exploring this novel finding allowed us to show that atmospheric oxygen level is the key determinant of altitude perception. We define the molecular pathway through which oxygen-sensing results in an adapted phenotype and we find that distinct species of flowering plants are adapted to absolute altitude through conserved oxygen-sensing control of chlorophyll synthesis and hypoxia gene expression. Showing that this mechanism works in diverse species provides a new paradigm for plant ecology."

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Past events reveal how future warming could harm cold-water corals

How will future warming of the planet impact cold-water corals? A new analysis of ancient evidence from the last major global warming event identifies food and oxygen supply as key environmental factors that influence the vitality of cold-water corals in the North Atlantic Ocean and the Mediterranean Sea. Rodrigo da Costa Portilho-Ramos of the University of Bremen, Germany, and colleagues present these findings in the open-access journal PLOS Biology on May 19th.

Much like tropical corals in shallower waters, cold-water corals serve as crucial "engineers" of deep-sea reefs and mounds that are home to rich, unique ecosystems. As climate change progresses, researchers predict, cold-water corals are likely to face harm from such factors as rising ocean temperatures, decreased food supply, lower oxygen levels, and ocean acidification. However, no extinctions of cold-water coral ecosystems have been documented in real-time, so the precise factors that may determine their fate have been unclear.

To shed new light, Portilho-Ramos and colleagues turned to ancient evidence of past climate change as captured in seafloor sediments. They analyzed sediments collected at or near six sites of cold-water coral ecosystems in the North Atlantic Ocean and the Mediterranean Sea, applying standard techniques to reconstruct ocean conditions and the abundance of the common coral species Lophelia pertusa over the last 20,000 years. This period encompasses Earth's last major global warming event.

The analysis revealed that ancient L. pertusa abundance was most strongly influenced by changes in food supply, delivered either vertically from shallower depths or by lateral water flow along the seafloor. Low oxygen concentration also appeared to be a key stressor for L. pertusa. Meanwhile, changes in ocean temperature and salinity did not appear to be significantly associated with proliferation or disappearance of L. pertusa over time.

These findings suggest that climate change-driven alterations to ocean processes that affect food and oxygen supplies may play key roles in the future health of cold-water coral ecosystems. In some cases, the data suggest, high abundance of food may compensate for low oxygen levels.

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