A carbon-lite atmosphere could be a sign of water and life on other terrestrial planets

In the search for extraterrestrial life, MIT scientists say a planet’s carbon-lite atmosphere, relative to its neighbors, could be a sure and detectable signal of habitability.
Image Credit: Scientific Frontline stock image.

Scientists at MIT, the University of Birmingham, and elsewhere say that astronomers’ best chance of finding liquid water, and even life on other planets, is to look for the absence, rather than the presence, of a chemical feature in their atmospheres.

The researchers propose that if a terrestrial planet has substantially less carbon dioxide in its atmosphere compared to other planets in the same system, it could be a sign of liquid water — and possibly life — on that planet’s surface.

What’s more, this new signature is within the sights of NASA’s James Webb Space Telescope (JWST). While scientists have proposed other signs of habitability, those features are challenging if not impossible to measure with current technologies. The team says this new signature, of relatively depleted carbon dioxide, is the only sign of habitability that is detectable now.

“The Holy Grail in exoplanet science is to look for habitable worlds, and the presence of life, but all the features that have been talked about so far have been beyond the reach of the newest observatories,” says Julien de Wit, assistant professor of planetary sciences at MIT. “Now we have a way to find out if there’s liquid water on another planet. And it’s something we can get to in the next few years.”

The team’s findings appear today in Nature Astronomy. De Wit co-led the study with Amaury Triaud of the University of Birmingham in the UK. Their MIT co-authors include Benjamin Rackham, Prajwal Niraula, Ana Glidden Oliver Jagoutz, Matej Peč, Janusz Petkowski, and Sara Seager, along with Frieder Klein at the Woods Hole Oceanographic Institution (WHOI), Martin Turbet of Ècole Polytechnique in France, and Franck Selsis of the Laboratoire d’astrophysique de Bordeaux.

Electronic “soil” enhances crop growth

Alexandra Sandéhn, PhD student, one of the lead authors, and Eleni Stavrinidou, Associate Professor, and supervisor of the study, connect the eSoil to a low power source for stimulating plant growth.
Photo Credit: Thor Balkhed

Barley seedlings grow on average 50% more when their root system is stimulated electrically through a new cultivation substrate. In a study published in the journal PNAS, researchers from Linköping University have developed an electrically conductive “soil” for soilless cultivation, known as hydroponics.

Alexandra Sandéhn, PhD student, one of the lead authors, and Eleni Stavrinidou, Associate Professor, and supervisor of the study, connect the eSoil to a low power source for stimulating plant growth. Thor Balkhed

“The world population is increasing, and we also have climate change. So, it’s clear that we won’t be able to cover the food demands of the planet with only the already existing agricultural methods. But with hydroponics we can grow food also in urban environments in very controlled settings,” says Eleni Stavrinidou, associate professor at the Laboratory of Organic Electronics at Linköping University, and leader of the Electronic Plants group.

Her research group has now developed an electrically conductive cultivation substrate tailored to hydroponic cultivation which they call eSoil. The Linköping University researchers have shown that barley seedlings grown in the conductive “soil” grew up to 50% more in 15 days when their roots were stimulated electrically.

Brain cell discovery sparks hope for fertility treatments

Photo Credit: Yoshihisa Uenoyama, Graduate School of Bioagricultural Sciences, Nagoya University

Researchers at Nagoya University’s Graduate School of Bioagricultural Sciences and the National Institute of Physiological Sciences in Japan have demonstrated how a specific type of neuron in the brain affects the release of hormones that control ovarian function, such as follicular development and ovulation in females. These findings, published in the journal Scientific Reports, could help researchers understand and treat reproductive disorders in both animals and humans.  

Kisspeptin neurons in the brain regulate the release of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary follicle-stimulating hormone/luteinizing hormone (LH). This process is important for reproduction, as pituitary hormones stimulate the ovaries to perform their reproductive functions. Examples include follicular development and ovulation in all mammals, including humans.   

There are two main areas of the brain involved in the process: the arcuate nucleus (ARC), in which kisspeptin neurons maintain the regular rhythmic (pulsatile) secretion of GnRH/LH that maintains normal follicular development and sex steroid production; and the anteroventral periventricular nucleus (AVPV), in which kisspeptin neurons trigger a surge of GnRH/LH that leads to ovulation.  

Human-driven extinction of birds much greater than previously known

The dodo was endemic to the island of Mauritius. It could not fly and was exterminated by man during the 17th century.
Image Credit: German Rojas

On many of the world's islands, bird species began to become extinct with the arrival of humans. In a new study involving researchers from the University of Gothenburg and Uppsala University, it is estimated that humans have contributed to the extinction of around 1,400 bird species – twice as high as previously thought.

Because the lightweight bones of birds break down quickly, few fossils are formed. In the past, when scientists had to rely on observations and fossils, it was estimated that 640 species of birds had become extinct during the lifetime of modern humans, 90 percent of them on islands inhabited by humans. Classic examples are the dodo on Mauritius and the great auk in the North Atlantic, which, like penguins, could not fly.

However, by using statistical modeling, scientists now dare to estimate that around 1,400 bird species have become extinct.

“This is twice as many species as those that have left fossils as evidence of their existence. “Virtually all of these species were wiped out directly or indirectly due to human activity,” says Søren Faurby, a researcher in Zoology at the University of Gothenburg and co-author of the study published in Nature Communications.

The Evolutionary Timeline of Diminished Boric Acid and Urea Transportation in Aquaporin 10

Aquaporin (Aqp) 10 water channels in humans allow the free passage of water, glycerol, urea, and boric acid across cells. However, Aqp10.2b in pufferfishes allows only the passage of water and glycerol and not urea and boric acid. Researchers from the Tokyo Institute of Technology sought to understand the evolutionary timeline that resulted in the variable substrate selection mechanisms among Aqp10s. Their results indicate that Aqp10.2 in ray-finned fishes may have reduced or lost urea and boric acid permeabilities through evolution.

Aquaporins (Aqps) are proteins that form water channels in the membranes of living cells, including those of bacteria, fungi, animals, and plants. These channels facilitate water transportation across cells more rapidly than diffusion through the membrane phospholipid bilayer.

Aqp10 belongs to the aquaglyceroporin subfamily of water channels. These proteins facilitate many of our body's physiological processes, including gut function, liver and fat cell metabolism, and skin elasticity. Water and solutes, such as glycerol, urea, and boric acid, get transported through human Aqp10 depending on concentration gradients across the membrane.

Sarcopterygians, which include coelacanths, lungfish, and tetrapods (such as amphibians, reptiles, birds, and mammals), are known to have a single gene that codes for Aqp10. In contrast, actinopterygians, such as ray-finned fishes, have paralogs, or near-identical copies, of the aqp10 gene, such as aqp10.1 and aqp10.2. Interestingly, the ray-finned Japanese pufferfish has paralog called aqp10.2b that shows permeability to water and glycerol but not to urea and boric acid.

Western Cascades landscapes in Oregon historically burned more often than previously thought

Students, tribal members and others visit the study site.
Photo Credit: Sarah Altemus Pope of the Southern Willamette Forest Collaborative.

Forests on the west slope of Oregon’s Cascade Range experienced fire much more often between 1500 and 1895 than had been previously thought, according to new research by scientists at Oregon State University.

The findings provide important insight, the authors say, into how landscapes might adapt to climate change and future fire regimes.

James Johnston of the OSU College of Forestry led the study, which was published in Ecosphere.

“Wildland fire is a fundamental forest ecosystem process,” he said. “With temperatures rising and more and more area burning, we need to know as much as we can about the long-term variability in fire.”

Johnson and collaborators at Oregon State, the University of Oregon and the U.S. Forest Service gathered tree ring data at 16 sites in the southern part of the Willamette National Forest, in the general vicinity of Oakridge.

Trees form scars after cambial cells are killed by wildfire heat, he said. These scars are partially or completely covered by new tissue as a tree grows, and tree rings tell the story of when the fire exposure occurred.

Risk of young-onset dementia could be reduced through targeting health and lifestyle factors

Researchers have identified a wide range of risk factors for young-onset dementia. The findings challenge the notion that genetics are the sole cause of the condition, laying the groundwork for new prevention strategies.

The largescale study identified 15 risk factors, which are similar to those for late-onset dementia. For the first time, they indicate that it may be possible to reduce the risk of young-onset dementia by targeting health and lifestyle factors.

Relatively little research has been done on young-onset dementia, though globally there are around 370,000 new cases of young-onset dementia each year.

Published in JAMA Neurology, the new research by the University of Exeter and Maastricht University followed more than 350,000 participants younger than 65 across the United Kingdom from the UK Biobank study. The team evaluated a broad array of risk factors ranging from genetic predispositions to lifestyle and environmental influences. The study revealed that lower formal education, lower socioeconomic status, genetic variation, lifestyle factors such as alcohol use disorder and social isolation, and health issues including vitamin D deficiency, depression, stroke, hearing impairment and heart disease significantly elevate risk of young-onset dementia

Blue PHOLEDs: Final color of efficient OLEDs finally viable in lighting

Jaesang Lee, Electrical Engineering PhD Student, demonstrates use of an earlier blue PHOLED innovation by University of Michigan professor Steve Forrest’s research group in 2014. Forrest’s lab introduced PHOLEDs to the world in the early 2000s and has been trying to improve the lifetime of blue PHOLEDs ever since. Now, they might finally be hardy enough to use in lighting applications. Image credit: Joseph Xu, Michigan Engineering Communications & Marketing The blue LEDs were developed in EECS Professor Stephen Forrest’s lab groups and are for use in cell phones, tablets, and other electronics. The LEDs’ lifetime has been enhanced by a factor of ten, allowing for more efficient use.
Photo Credit: Joseph Xu, Michigan Engineering Communications & Marketing

Lights could soon use the full color suite of perfectly efficient organic light-emitting diodes, or OLEDs, that last tens of thousands of hours, thanks to an innovation from physicists and engineers at the University of Michigan.

The U-M team’s new phosphorescent OLEDs, commonly referred to as PHOLEDs, can maintain 90% of the blue light intensity for 10-14 times longer than other designs that emit similar deep blue colors. That kind of lifespan could finally make blue PHOLEDs hardy enough to be commercially viable in lights that meet the Department of Energy’s 50,000-hour lifetime target. Without a stable blue PHOLED, OLED lights need to use less-efficient technology to create white light.

The lifetime of the new blue PHOLEDs currently is only long enough to use as lighting, but the same design principle could be combined with other light-emitting materials to create blue PHOLEDs hardy enough for TVs, phone screens and computer monitors. Display screens with blue PHOLEDs could potentially increase a device’s battery life by 30%.

How antibiotic-resistant bacteria can teach us to modify behavior

UCLA researchers used knowledge of biological resistance to build a framework for modifying behavior that contributes to climate change.
Photo Credit: Arndt-Peter Bergfeld

Most people want to do something about climate change, but lifestyle trade-offs and a narrowing window to enact broad changes to industrial, transportation, and consumption patterns are daunting enough to make them resist.  

Resistance has different meanings across different fields of study. But UCLA biologists who study resistance in the natural world believe insights gleaned from some of its smallest inhabitants could help identify barriers to social changes, including those required to resolve human–wildlife conflicts, and formulate specific strategies for overcoming them.

Biologists have long studied how agricultural pests become resistant to pesticides and how bacteria evolve antibiotic resistance. UCLA researchers have pinpointed several effective tactics to counter this resistance that could help humans embrace urgently needed changes, they suggest in a paper published in Evolutionary Applications. 

The team built a framework of biologically derived resistance management strategies, suggesting that the different views of resistance can help to identify friction points between humans and the natural world, and between humans and their social worlds.  

Nanoscale Analysis Provides Key Answers for Modeling Mineralization in Basalt

A methodology on resolving nanoscale processes during carbon mineralization—discovered and led by Pacific Northwest National Laboratory Post Doctoral Researcher Xiaoxu Li and Chemist Emily Nienhuis—provides insight into the previous knowledge gaps needed for accurate reservoir models.  
Composite Credit: Mike Perkins | Pacific Northwest National Laboratory

Removing carbon dioxide (CO2) from industrial emissions and from the atmosphere and then safely storing it into the Earth’s deep subsurface is becoming increasingly essential to meeting decarbonization goals and preserving a livable planet.

Pacific Northwest National Laboratory (PNNL) scientists discovered how to store supercritical CO2—carbon dioxide in its fluid state—in basalt reservoirs safely and permanently. This process is called geologic carbon sequestration, or carbon mineralization. But for the technology to be deployed commercially in the United States a Class VI well permit must first be attained.

“In order to apply for and be issued this permit, there has to be what is called a reservoir model for us to understand the fate and behavior of the injected CO2,” said PNNL Chemist Emily Nienhuis. “In other words, if we inject x amount of CO2 into a reservoir, where does it go? And how long does it take to mineralize or become rock?”