Heaviest element yet detected in an exoplanet atmosphere

Using the European Southern Observatory's Very Large Telescope (ESO's VLT), astronomers have discovered the heaviest element ever found in an exoplanet atmosphere -- barium. They were surprised to discover barium at high altitudes in the atmospheres of the ultra-hot gas giants WASP-76 b and WASP-121 b -- two exoplanets, planets which orbit stars outside our Solar System. This unexpected discovery raises questions about what these exotic atmospheres may be like.

"The puzzling and counterintuitive part is: why is there such a heavy element in the upper layers of the atmosphere of these planets?" says Tomás Azevedo Silva, a PhD student at the University of Porto and the Instituto de Astrofísica e Ciências do Espaço (IA) in Portugal who led the study published today in Astronomy & Astrophysics.

WASP-76 b and WASP-121 b are no ordinary exoplanets. Both are known as ultra-hot Jupiters as they are comparable in size to Jupiter whilst having extremely high surface temperatures soaring above 1000°C. This is due to their close proximity to their host stars, which also means an orbit around each star takes only one to two days. This gives these planets rather exotic features; in WASP-76 b, for example, astronomers suspect it rains iron.

But even so, the scientists were surprised to find barium, which is 2.5 times heavier than iron, in the upper atmospheres of WASP-76 b and WASP-121 b. "Given the high gravity of the planets, we would expect heavy elements like barium to quickly fall into the lower layers of the atmosphere," explains co-author Olivier Demangeon, a researcher also from the University of Porto and IA.

"This was in a way an 'accidental' discovery," says Azevedo Silva. "We were not expecting or looking for barium in particular and had to cross-check that this was actually coming from the planet since it had never been seen in any exoplanet before."

The fact that barium was detected in the atmospheres of both of these ultra-hot Jupiters suggests that this category of planets might be even stranger than previously thought. Although we do occasionally see barium in our own skies, as the brilliant green colour in fireworks, the question for scientists is what natural process could cause this heavy element to be at such high altitudes in these exoplanets. "At the moment, we are not sure what the mechanisms are," explains Demangeon.

In the study of exoplanet atmospheres ultra-hot Jupiters are extremely useful. As Demangeon explains: "Being gaseous and hot, their atmospheres are very extended and are thus easier to observe and study than those of smaller or cooler planets."

Determining the composition of an exoplanet's atmosphere requires very specialised equipment. The team used the ESPRESSO instrument on ESO's VLT in Chile to analyse starlight that had been filtered through the atmospheres of WASP-76 b and WASP-121 b. This made it possible to clearly detect several elements in them, including barium.

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Study of over 5 million people's DNA reveals genetic links to height

The study, published today (12 October) in Nature, is the largest ever genome-wide association study, using the DNA of over 5 million people from 281 contributing studies. It plugs a sizeable gap in our understanding of how our genetic differences account for differences in height. Over 1 million of the study's participants are of non-European -- African, East Asian, Hispanic or South Asian -- ancestry.

The 12,111 variants, which cluster around parts of the genome associated with skeletal growth, provide a powerful genetic predictor for height. The variants identified explain 40% of the variation in height for people of European ancestry, and around 10-20% for those of non-European ancestry.

Adult height is mostly determined by the information encoded in our DNA -- children from tall parents tend to be taller and those from short parents are shorter, but these estimates aren't perfect. Growth from a small baby into an adult, and the role genetics play in this, have traditionally been a complex and poorly understood area of human biology. Previously, the largest genome-wide association study looking at height used a sample size of up to 700,000 individuals, the current sample is about seven times more than previous studies.

The unprecedented scale of the research provides new levels of detail and biological insight as to why people are tall or short, with heritability being linked to various specific genomic regions. The findings show that genetic variants associated with height are concentrated in regions covering just over 20% of the genome.

The study's findings could help doctors to identify people who are not able to reach their genetically predicted height, which may then aid in the diagnosis of hidden diseases or conditions that may be stunting their growth or impacting their health. The research also provides a valuable blueprint on how it could be possible to use genome-wide studies to identify a disease's biology and subsequently its hereditary components.

Greater genomic diversity needed

While this study has a large number of participants from non-European ancestries compared to previous studies, the researchers emphasise the need for more diversity in genomic research.

Most of the genetic data available is from people of European ancestry, so genome-wide studies don't capture the wide range of ancestral diversity across the globe. Increasing the size of genome-wide studies in non-European ancestry populations is essential to achieve the same level of saturation and close the gap in prediction accuracy in different populations.

Dr Eirini Marouli, co-first author of the study and Senior Lecturer in Computational Biology at Queen Mary University of London, said:

"We have accomplished a feat in studying the DNA of over 5 million people that was broadly considered impossible until recently.

"Genomic studies are revolutionary and might hold the key to solving many global health challenges -- their potential is tremendously exciting. If we can get a clear picture of a trait such as height at a genomic level, we may then have the model to better diagnose and treat gene-influenced conditions like heart disease or schizophrenia, for example.

"If we can map specific parts of the genome to certain traits, it opens the door to widespread targeted, personalised treatments further down the line that could benefit people everywhere."

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Red alert: Massive stars sound warning they are about to go supernova

Astronomers from Liverpool John Moores University and the University of Montpellier have devised an 'early warning' system to sound the alert when a massive star is about to end its life in a supernova explosion. The work was published in Monthly Notices of the Royal Astronomical Society.

In this new study, researchers determined that massive stars (typically between 8 and 20 solar masses) in the last phase of their lives, the so-called 'red supergiant' phase, will suddenly become around a hundred times fainter in visible light in the last few months before they die. This dimming is caused by a sudden accumulation of material around the star, which obscures its light.

Until now, it was not known how long it took the star to accrete this material. Now, for the first time, researchers have simulated how red supergiants might look when they are embedded within these pre-explosion 'cocoons'.

Old telescope archives show that images do exist of stars that went on to explode around a year after the image was taken. The stars appear as normal in these images, meaning they cannot yet have built up the theoretical circumstellar cocoon. This suggests that the cocoon is assembled in less than a year, which is considered to be extremely fast.

Benjamin Davies from Liverpool John Moores University, and lead author of the paper, says "The dense material almost completely obscures the star, making it 100 times fainter in the visible part of the spectrum. This means that, the day before the star explodes, you likely wouldn't be able to see it was there." He adds, "Until now, we've only been able to get detailed observations of supernovae hours after they've already happened. With this early-warning system we can get ready to observe them real-time, to point the world's best telescopes at the precursor stars, and watch them getting literally ripped apart in front of our eyes."

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Dinosaur 'mummies' might not be as unusual as we think

A process of desiccation and deflation explains why dinosaur "mummies" aren't as exceptional as we might expect, according to a study published October 12, 2022 in the open-access journal PLOS ONE by Stephanie Drumheller of the University of Tennessee-Knoxville and colleagues.

The term "mummy" is often used to describe dinosaur fossils with fossilized skin, which are relatively rare. It is commonly suggested that such fossils only form under exceptional circumstances and that a carcass must be shielded from scavenging and decomposition by rapid burial and/or desiccation in order for skin to become fossilized. In this study, Drumheller and colleagues combine fossil evidence with observations on modern animal carcasses to propose a new explanation for how such "mummies" might form.

The researchers examined a fossil of a dinosaur called Edmontosaurus from North Dakota which preserves large patches of desiccated and seemingly deflated skin on the limbs and tail. They identified bite marks from carnivores upon the dinosaur's skin. These are the first examples of unhealed carnivore damage on fossil dinosaur skin, and furthermore, this is evidence that the dinosaur carcass was not protected from scavengers, yet it became a mummy nonetheless.

Modern animal carcasses are known to be often emptied out as scavengers and decomposers target internal tissues, leaving behind skin and bone. The authors propose that damage to this dinosaur's skin from this incomplete scavenging would have exposed its insides and allowed a similar process to occur, after which the skin and bones became slowly desiccated and buried.

This process, which the authors call "desiccation and deflation," is common with modern carcasses and explains how dinosaur mummies might form under relatively ordinary circumstances. The authors stress that there are likely numerous pathways by which a dinosaur mummy might develop. Understanding these mechanisms will guide how paleontologists collect and interpret such rare and informative fossils.

Clint Boyd, Senior Paleontologist at the North Dakota Geological Survey, adds: "Not only has Dakota taught us that durable soft tissues like skin can be preserved on partially scavenged carcasses, but these soft tissues can also provide a unique source of information about the other animals that interacted with a carcass after death."

From Science Daily

Smelling in VR environment possible with new gaming technology

An odor machine, so-called olfactometer, makes it possible to smell in VR environments. First up is a "wine tasting game" where the user smells wine in a virtual wine cellar and gets points if the guess on aromas in each wine is correct. The new technology that can be printed on 3D printers has been developed in collaboration between Stockholm University and Malmö University. The research, funded by the Marianne and Marcus Wallenberg Foundation, was recently published in the International Journal of Human -- Computer Studies.

"We hope that the new technical possibilities will lead to scents having a more important role in game development, says Jonas Olofsson, professor of psychology and leader of the research project at Stockholm University.

In the past, computer games have focused mostly on what we can see -- moving images on screens. Other senses have not been present. But an interdisciplinary research group at Stockholm University and Malmö University has now constructed a scent machine that can be controlled by a gaming computer. In the game, the participant moves in a virtual wine cellar, picking up virtual wine glasses containing different types of wine, guessing the aromas. The small scent machine is attached to the VR system's controller, and when the player lifts the glass, it releases a scent.

"The possibility to move on from a passive to a more active sense of smell in the game world paves the way for the development of completely new smell-based game mechanics based on the players' movements and judgments," says Simon Niedenthal, interaction and game researcher at Malmö University.

The olfactometer consists of four different valves each connected to a channel. In the middle there is a fan sucking the air into a tube. With the help of the computer, the player can control the four channels so that they open to different degrees and provide different mixtures of scent. Scent blends that can mimic the complexity of a real wine glass. The game has different levels of difficulty with increasing levels of complexity.

"In the same way that a normal computer game becomes more difficult the better the player becomes; the scent game can also challenge players who already have a sensitive nose. This means that the scent machine can even be used to train wine tasters or perfumers," says Jonas Olofsson.

All code, blueprints and instructions for the machine are openly available online, as is code for the virtual wine tasting game. The research group, Sensory Cognitive Interaction Laboratory, which is located at the Department of Psychology, Stockholm University, now hopes that scented computer games can become useful for other purposes.

"For those who, for example, lost their sense of smell after COVID-19 or for other reasons, the new technology can mean an opportunity to regain their sense of smell with the help of game-based training," says Jonas Olofsson, research team leader.

Smell training is a method recommended by doctors for those who lose their sense of smell after colds and other viruses, but according to Jonas Olofsson, many people stop training because it becomes too boring.

"I hope that the fact that drawings and code are openly available as "open source" will lead to an opportunity for game companies to start creating new, commercial products for scent training using the new technology," says Jonas Olofsson.

According to Simon Niedenthal, "open source" leads to promoting accessibility, reproducibility and comparison of results in research. It also contributes to creating a cohesive research and design community within the game development field.

"But it also means that the costs of the equipment are greatly reduced, which makes it available to more people. To us that is important," says Simon Niedenthal.

"We believe in open science, that research results should be made available to the public and that other researchers should be able to repeat our results. With the help of our research, others can build scent machines and explore new ways of using scents in games," says Jonas Olofsson.

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A new species of deep-sea fish discovered in the Atacama Trench

A new small blue snailfish is changing our understanding of the world's deepest fishes.

In 2018, an international team of scientists studied the Atacama Trench, an expansive trench that runs along the west coast of South America as a deep underwater valley that mirrors the Andes Mountains. The team, including Newcastle University scientists, deployed free-falling landers to sample the sparse deep-sea creatures around cameras and traps with bait. Two lander systems from Newcastle University recorded three types of hadal snailfish and one of them was not like the others.

The small blue fish, seen from about 6,000 to 7,600 m deep, doesn't look like other hadal snailfish. With large eyes and striking colour, it resembles other species of snailfishes that are found living in much shallower waters. The team used a 3D x-ray technique called microcomputed tomography (micro-CT) and DNA barcoding to see where the new species fit within the snailfish family.

To the team's surprise, the new species appears to be a separate coloniser of the Atacama Trench. The new species belongs is a member of the genus Paraliparis. Species in this genus are particularly abundant in the Southern Ocean of the Antarctic and are rarely found deeper than 2,000 m. Significantly, this is the first time this genus has been found living in the hadal zone.

The team named the new species Paraliparis selti, meaning blue in the Kunza language of the indigenous peoples of the Atacama Desert. The description is published in the journal Marine Biodiversity.

Study lead author, Dr Thom Linley, a visiting researcher at Newcastle University said: "I find this family of fishes absolutely fascinating. They are not at all what we expect from a deep-sea fish and I love to show people that the world's deepest fishes are actually pretty cute.

"For me to get a camera down to where these animals live, it's made of inches thick stainless steel and sapphire glass. It then films these delicate and beautiful animals perfectly adapted to this extreme environment. With engineering-built force we can only clumsily visit these animals for a short time.

"We have been wondering for some time just what makes this type of fish so good at living deep. Maybe it was a series of lucky accidents, a chance fluke, that happened in one lineage. Finding this new species tells us that it's bigger than that. Lightning struck twice and there is something special about this Family.

"Paraliparis selti provides a fantastic opportunity to explore what allows fish to live so deep. If we only had a single lineage to study, we could never be sure which traits were just part of that lineage and which are the deep-sea secret sauce."

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Dust plumes observed being 'pushed' into interstellar space by intense starlight

The results, made using infrared images of the binary star system WR140 taken over 16 years, are reported in the journal Nature.

In a complementary study of WR140, published in Nature Astronomy, NASA's James Webb Space Telescope (JWST) was able to see much deeper to snap an image of not just a single accelerating dust plume, but almost 20 of them, nested inside each other like a giant set of onion skins.

WR140 is comprised of a huge Wolf-Rayet star and an even bigger blue supergiant star, gravitationally bound in an eight-year orbit. This binary star, in the Cygnus constellation, has been monitored for two decades with one of the world's largest optical telescopes at the Keck Observatory in Hawaii.

WR140 episodically puffs out plumes of dust stretching thousands of times the distance from the Earth to the Sun. These dust plumes, produced every eight years, give astronomers a unique opportunity to observe how starlight can affect matter.

It's known that light carries momentum, exerting a push on matter known as radiation pressure. Astronomers often witness the outcome of this phenomenon in the form of matter coasting at high speed around the cosmos, but it's been a difficult process to catch in the act. Direct recording of acceleration due to forces other than gravity is rarely witnessed, and never in a stellar environment like this.

"It's hard to see starlight causing acceleration because the force fades with distance, and other forces quickly take over," said Yinuo Han from Cambridge's Institute of Astronomy, first author of the Nature paper. "To witness acceleration at the level that it becomes measurable, the material needs to be reasonably close to the star or the source of the radiation pressure needs to be extra strong. WR140 is a binary star whose ferocious radiation field supercharges these effects, placing them within reach of our high-precision data."

All stars generate stellar winds, but those from Wolf-Rayet stars can be more like a stellar hurricane. Elements such as carbon in the wind condense out as soot, which remains hot enough to glow bright in the infrared. Like smoke in the wind, this gives telescopes something that can be observed.

The team used an imaging technology known as interferometry which was able to act like a zoom lens for the 10-metre Keck telescope mirror, enabling the researchers to recover sufficiently sharp images of WR140 for the study.

Han and his team found that the dust does not stream out from the star with the wind in a hazy ball. Instead, the dust forms where the winds from the two stars collide, on the surface of a cone-shaped shock front between them.

Because the orbiting binary star is in constant motion, the shock front also rotates. The sooty plume gets wrapped into a spiral, in the same way that droplets form a spiral in a garden sprinkler.

The researchers found that WR140 has other tricks up its sleeve. The two stars are not on circular but rather elliptical orbits, and dust production turns on and off as the binary nears and departs the point of closest approach. By modelling these effects into the three-dimensional geometry of the dust plume, the astronomers were able to measure to location of dust features in three-dimensional space.

"Like clockwork, this star puffs out sculpted smoke rings every eight years, with all this wonderful physics written then inflated in the wind like a banner for us to read," said co-author Professor Peter Tuthill from the University of Sydney. "Eight years later as the binary returns in its orbit, another appears the same as the one before, streaming out into space inside the bubble of the previous one, like a set of giant nested Russian dolls."

Because the dust produced by this Wolf-Rayet is so predictable and expands to such large distances, it offered the astronomers a unique laboratory to examine the acceleration zone.

"In the absence of external forces, each dust spiral should expand at a constant speed," said Han, who is also a co-author on the JWST paper. "We were puzzled at first because we could not get our model to fit the observations, until we finally realised that we were seeing something new. The data did not fit because the expansion speed wasn't constant, but rather that it was accelerating. We'd caught that for the first time on camera."

"In one sense, we always knew this must be the reason for the outflow, but I never dreamed we'd be able to see the physics at work like this," said Tuthill. "When I look at the data now, I see WR140's plume unfurling a like giant sail made of dust. When it catches the photon wind streaming from the star, like a yacht catching a gust, it makes a sudden leap forward."

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Toward a fully edible sensor showing if frozen food has previously thawed

When you're standing in the frozen food aisle, it's nearly impossible to know whether that Salisbury steak has thawed and refrozen -- a process with potentially harmful consequences. So, researchers reporting in ACS Sensors have designed a food-grade device from edible materials, including table salt, red cabbage and beeswax, that lets you know. The proof-of-concept sensor provides a color readout when it's warmed above a specific temperature, which is tunable from -58 F to 32 F.

Keeping food cold while it's transported and stored is essential to retaining its flavor and quality, reducing the risk of food poisoning and minimizing waste. While researchers have developed devices that alert manufacturers when cold items are exposed to unwanted temperatures, they only indicate changes above freezing. To create a sensor for frozen products, one solution could be to use materials with electrical properties that are altered upon melting. It would also be ideal if such changes could produce a signal, such as a visible color change. In addition, an edible electronic device, which uses only food and consumable components, would be the safest way to monitor food. So, Ivan Ilic, Mario Caironi and colleagues set out to develop the first fully edible, self-powered temperature sensor with a visible color indicator for use with frozen products.

The researchers started by building a device that generated an electrical current as it defrosted, connecting magnesium and gold electrodes through an electrolyte solution held in a plastic container. They tested the device with solutions of frozen edible electrolytes, including table salt and calcium-containing salts, and naturally electrolyte-rich foods, including a grape, melon and apple. As the solutions defrosted, they conducted current between -58 F and 32 F, which the researchers say could be fine-tuned, based on the amount and identity of the salt. Next, this device was connected to a color-changing system, containing tin and gold electrodes and red cabbage juice, that produced an irreversible shift from reddish purple to blue when current was applied.

In the final step, the team put all of the parts together in a block of beeswax that held the temperature-activated and indicator solutions in separate chambers, and demonstrated that the self-powered device could be used for frozen food monitoring. The researchers say that their proof-of-concept sensor paves the way for edible materials to be used in inexpensive, safe technologies that alert customers to a frozen product's storage history.

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The entire planet's ecosystems classified

A global cross-disciplinary team of scientists led by UNSW Sydney researchers has developed the first comprehensive classification of the world's ecosystems across land, rivers and wetlands, and seas. The ecosystem typology will enable more coordinated and effective biodiversity conservation, critical for human wellbeing.

The extensive collaboration includes the International Union for Conservation of Nature (IUCN), which comprises about 1400 member organisations, including countries; the IUCN Commission on Ecosystem Management; the PLuS Alliance -- Arizona State University, King's College London and UNSW Sydney; and more than 100 specialist ecosystem scientists around the world.

The study, published today in Nature, explores the science that underpins the typology, as well as how it can help achieve objectives in global policy that flow to individual countries. With UNSW's support, IUCN launched the first public version of the typology in 2020 and, since then, the researchers have refined and updated it.

The research team was led by Professor David Keith with Professor Richard Kingsford from UNSW's Centre for Ecosystem Science, and Professor Emily Nicholson from Deakin University.

"For the first time, we have a common platform that identifies, defines and describes the full suite of the whole planet's ecosystems," said Professor Keith.

"It may seem rather odd that we haven't had this before, but historically scientists have forged advances by working somewhat separately in marine, freshwater and terrestrial ecosystems. This is the first time that all of this detailed knowledge has been brought together into a single framework taking advantage of common theory across the disciplines."

The typology allows us to understand broad global patterns, including the transformation of ecosystems by people. Ten per cent of ecosystems are artificially created and maintained by humans but occupy more than 30 per cent of the Earth's land surface -- what is left is home to 94 per cent of threatened species on the IUCN Red List.

At a policy level, this is the first time we've had this kind of overview, Professor Kingsford said.

"It's very hard to see the big picture on a jigsaw puzzle until you have all the pieces in place -- and that's what we now have. We have a much more substantial foundation to move ahead with a new era of ecosystem conservation and management policy."

At a more general level, the overview allows policymakers and industry to plan their initiatives in full context. For governments and non-government organisations (NGOs) working in a range of countries, the overview can inform decisions about how ecosystem protection and restoration efforts can achieve maximum conservation benefit, and where development infrastructure is best placed to minimise impact.

"Efforts on biodiversity conservation have largely centered at the species level, because it's seen to be more tangible," said Professor Keith. "But a broader focus on both ecosystems and species is more likely to succeed in conserving all plants and animals, as well as the essential services that nature provides people."

Globally, countries coordinate their efforts under the umbrella of the United Nations Convention on Biological Diversity (CBD), which is coming up for renewal at the end of 2022. Delegates from 193 countries will meet in December at the 15th Conference of Parties in Montreal, Canada, to agree on the post-2020 agenda for CBD. Preparations for that meeting indicate a stronger emphasis on ecosystem conservation and management in the coming decades.

"The global ecosystem typology will make it possible to account for ongoing ecosystem change, identify threatened ecosystem types, and plan better preventative action and restoration under a renewed agenda for the CBD," said Professor Nicholson.

This typology marks a breakthrough for sustainable management of the world's ecosystems, said Dr Angela Andrade, Chair of IUCN's Commission on Ecosystem Management and one of the authors.

"It will enable real progress on United Nations Sustainable Development Goals and Environmental Accounting, and should help place ecosystems at the forefront of the United Nations' post-2020 agenda for conserving biological diversity."

To make that a reality, we need a full set of high quality maps for all major ecosystem types, Professor Keith said.

"We are already well down that path, but we need help to surmount the considerable challenges by exploiting recent advances in computer and satellite technology, along with global networks of citizen scientists."

The ecosystem typology

Ecosystems provide homes and vital life support for all plants and animals, and supply essential ecosystem services that sustain business, culture and human wellbeing. Those services -- such as provision of clean air and water, carbon sequestration, reduced risks of disasters and outdoor recreational opportunities that sustain mental health -- are sometimes regarded as free, but ecosystem degradation incurs costs for tapping alternative resources, disaster relief and reconstruction, and to health budgets.

All of the world's ecosystems show hallmarks of human influence, and many are under acute risks of collapse, with consequences for habitats of species, genetic diversity, ecosystem services, sustainable development and human wellbeing.

The global ecosystem typology describes the diversity of tropical forests, big rivers, coral reefs and other ecosystems that have typically been the focus of public attention. But it also includes little-known ecosystems of deep ocean trenches, seamounts, lakes beneath the ice sheets and microscopic ecosystems within rocks.

"We don't think often about what's in the deep oceans, for example," said Professor Keith. "There's a tremendous variety of life down there and it's organised into a number of different ecosystems. And those ecosystems are beginning to feel the impact of human expansion.

"The deep trenches in the ocean are filling up with microplastics, and we're starting to look at mining volcanic vents for minerals. We need to make decisions about those kinds of environments, just as we do about coral reefs and rainforests."

A hierarchical structure

The new typology has a hierarchical structure with six levels. The top level divides the planet into major realms, including terrestrial, freshwater, marine and subterranean ecosystems. The second and third levels include 25 biomes and 110 ecosystem functional groups, based on the ecological processes that shape different ecosystems and the functions that their key components perform. These functional groups will frame blueprints for sustainable ecosystem management.

The lower levels of the hierarchy are based on finer ecosystem features and enable the integration of existing national classifications. These national ecosystem classifications and maps benefit from detailed scientific observations and considerable investment over many years. They are critical to conservation because many countries have built their environmental governance and regulations around them, as well as their protected area networks. For the first time, a globally agreed typology enables these many different systems to be reconciled across national borders, while supporting their ongoing use in each country.

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Human brain cells in a dish learn to play Pong in real time

Human and mouse neurons in a dish learned to play the video game Pong, researchers report October 12 in the journal Neuron. The experiments are evidence that even brain cells in a dish can exhibit inherent intelligence, modifying their behavior over time.

"From worms to flies to humans, neurons are the starting block for generalized intelligence," says first author Brett Kagan (@ANeuroExplorer), chief scientific officer at Cortical Labs in Melbourne, Australia. "So, the question was, can we interact with neurons in a way to harness that inherent intelligence?"

To start, the researchers connected the neurons to a computer in such a way where the neurons received feedback on whether their in-game paddle was hitting the ball. They monitored the neuron's activity and responses to this feedback using electric probes that recorded "spikes" on a grid.

The spikes got stronger the more a neuron moved its paddle and hit the ball. When neurons missed, their playstyle was critiqued by a software program created by Cortical Labs. This demonstrated that the neurons could adapt activity to a changing environment, in a goal-oriented way, in real time.

"We chose Pong due to its simplicity and familiarity, but, also, it was one of the first games used in machine learning, so we wanted to recognize that," says Kagan, who worked with collaborators from 10 other institutions on the project.

"An unpredictable stimulus was applied to the cells, and the system as a whole would reorganize its activity to better play the game and to minimize having a random response," he says. "You can also think that just playing the game, hitting the ball and getting predictable stimulation, is inherently creating more predictable environments."

The theory behind this learning is rooted in the free-energy principle. Simply put, the brain adapts to its environment by changing either its world view or its actions to better fit the world around it.

Pong wasn't the only game the research team tested. "You know when the Google Chrome browser crashes and you get that dinosaur that you can make jump over obstacles (Project Bolan). We've done that and we've seen some nice preliminary results, but we still have more work to do building new environments for custom purposes," says Kagan.

Future directions of this work have potential in disease modeling, drug discoveries, and expanding the current understanding of how the brain works and how intelligence arises.

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Black hole spews out material years after shredding star

In October 2018, a small star was ripped to shreds when it wandered too close to a black hole in a galaxy located 665 million light years away from Earth. Though it may sound thrilling, the event did not come as a surprise to astronomers who occasionally witness these violent incidents while scanning the night sky.

But nearly three years after the massacre, the same black hole is lighting up the skies again -- and it hasn't swallowed anything new, scientists say.

"This caught us completely by surprise -- no one has ever seen anything like this before," says Yvette Cendes, a research associate at the Center for Astrophysics | Harvard & Smithsonian (CfA) and lead author of a new study analyzing the phenomenon.

The team concludes that the black hole is now ejecting material traveling at half of the speed of light, but are unsure why the outflow was delayed by several years. The results, described this week in the Astrophysical Journal, may help scientists better understand black holes' feeding behavior, which Cendes likens to "burping" after a meal.

The team spotted the unusual outburst while revisiting tidal disruption events (TDEs) -- when encroaching stars are spaghettified by black holes -- that occurred over the last several years.

Radio data from the Very Large Array (VLA) in New Mexico showed that the black hole had mysteriously reanimated in June 2021. Cendes and the team rushed to examine the event more closely.

"We applied for Director's Discretionary Time on multiple telescopes, which is when you find something so unexpected, you can't wait for the normal cycle of telescope proposals to observe it," Cendes explains. "All the applications were immediately accepted."

The team collected observations of the TDE, dubbed AT2018hyz, in multiple wavelengths of light using the VLA, the ALMA Observatory in Chile, MeerKAT in South Africa, the Australian Telescope Compact Array in Australia, and the Chandra X-Ray Observatory and the Neil Gehrels Swift Observatory in space.

Radio observations of the TDE proved the most striking.

"We have been studying TDEs with radio telescopes for more than a decade, and we sometimes find they shine in radio waves as they spew out material while the star is first being consumed by the black hole," says Edo Berger, professor of astronomy at Harvard University and the CfA, and co-author on the new study. "But in AT2018hyz there was radio silence for the first three years, and now it's dramatically lit up to become one of the most radio luminous TDEs ever observed."

Sebastian Gomez, a postdoctoral fellow at the Space Telescope Science Institute and co-author on the new paper, says that AT2018hyz was "unremarkable" in 2018 when he first studied it using visible light telescopes, including the 1.2-m telescope at the Fred Lawrence Whipple Observatory in Arizona.

Gomez, who was working on his doctoral dissertation with Berger at the time, used theoretical models to calculate that the star torn apart by the black hole was only one tenth the mass of our Sun.

"We monitored AT2018hyz in visible light for several months until it faded away, and then set it out of our minds," Gomez says.

TDEs are well-known for emitting light when they occur. As a star nears a black hole, gravitational forces begin to stretch, or spaghettify, the star. Eventually, the elongated material spirals around the black hole and heats up, creating a flash that astronomers can spot from millions of light years away.

Some spaghettified material occasionally gets flung out back into space. Astronomers liken it to black holes being messy eaters -- not everything they try to consume makes it into their mouths.

But the emission, known as an outflow, normally develops quickly after a TDE occurs -- not years later. "It's as if this black hole has started abruptly burping out a bunch of material from the star it ate years ago," Cendes explains.

In this case, the burps are resounding.

The outflow of material is traveling as fast as 50 percent the speed of light. For comparison, most TDEs have an outflow that travels at 10 percent the speed of light, Cendes says.

"This is the first time that we have witnessed such a long delay between the feeding and the outflow," Berger says. "The next step is to explore whether this actually happens more regularly and we have simply not been looking at TDEs late enough in their evolution."

Read more at Science Daily

Black hole discovered firing jets at neighboring galaxy

With the help of citizen scientists, a team of astronomers has discovered a unique black hole spewing a fiery jet at another galaxy. The black hole is hosted by a galaxy around one billion light years away from Earth named RAD12. The work was published today in Monthly Notices of the Royal Astronomical Society (Letters).

Galaxies are typically divided into two major classes based on their morphology: spirals and ellipticals. Spirals have optically-blue looking spiral arms with an abundance of cold gas and dust. In spiral galaxies, new stars form at an average rate of one Sun-like star per year. In contrast elliptical galaxies appear yellowish and lack distinct features such as spiral arms.

Star formation in elliptical galaxies is very scarce; it is still a mystery to astronomers as to why the elliptical galaxies we see today have not been forming new stars for billions of years. Evidence suggests that supermassive or 'monster' black holes are responsible. These 'monster' black holes spew gigantic jets made of electrons moving at very high speeds at other galaxies, depleting the fuel required for future star formation: cold gas and dust.

The unique nature of RAD12 had been observed in 2013 using optical data from the Sloan Digitised Sky Survey (SDSS) and radio data from the Very Large Array (FIRST survey). However, follow-up observation with the Giant Meterwave Radio Telescope (GMRT) in India was required to confirm its truly exotic nature: The black hole in RAD12 appears to be ejecting the jet only towards a neighbouring galaxy, named RAD12-B. In all cases, jets are ejected in pairs, moving in opposite directions at relativistic speeds. Why only one jet is seen coming from RAD12 remains a puzzle to astronomers.

A conical stem of young plasma is seen being ejected from the centre and reaches far beyond the visible stars of RAD12. The GMRT observations revealed that the fainter and older plasma extends far beyond the central conical stem and flares out like the cap of a mushroom (seen in red in the tricolour image). The whole structure is 440 thousand light years long, which is much larger than the host galaxy itself.

RAD12 is unlike anything known so far; this is the first time a jet has been observed to collide with a large galaxy like RAD12-B. Astronomers are now one step closer to understanding the impact of such interactions on elliptical galaxies, which may leave them with little cold gas for future star formation.

Read more at Science Daily

NASA confirms DART mission impact changed asteroid's motion in space

Analysis of data obtained over the past two weeks by NASA's Double Asteroid Redirection Test (DART) investigation team shows the spacecraft's kinetic impact with its target asteroid, Dimorphos, successfully altered the asteroid's orbit. This marks humanity's first time purposely changing the motion of a celestial object and the first full-scale demonstration of asteroid deflection technology.

"All of us have a responsibility to protect our home planet. After all, it's the only one we have," said NASA Administrator Bill Nelson. "This mission shows that NASA is trying to be ready for whatever the universe throws at us. NASA has proven we are serious as a defender of the planet. This is a watershed moment for planetary defense and all of humanity, demonstrating commitment from NASA's exceptional team and partners from around the world."

Prior to DART's impact, it took Dimorphos 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos. Since DART's intentional collision with Dimorphos on Sept. 26, astronomers have been using telescopes on Earth to measure how much that time has changed. Now, the investigation team has confirmed the spacecraft's impact altered Dimorphos' orbit around Didymos by 32 minutes, shortening the 11 hour and 55-minute orbit to 11 hours and 23 minutes. This measurement has a margin of uncertainty of approximately plus or minus 2 minutes.

Before its encounter, NASA had defined a minimum successful orbit period change of Dimorphos as change of 73 seconds or more. This early data show DART surpassed this minimum benchmark by more than 25 times.

"This result is one important step toward understanding the full effect of DART's impact with its target asteroid" said Lori Glaze, director of NASA's Planetary Science Division at NASA Headquarters in Washington. "As new data come in each day, astronomers will be able to better assess whether, and how, a mission like DART could be used in the future to help protect Earth from a collision with an asteroid if we ever discover one headed our way."

The investigation team is still acquiring data with ground-based observatories around the world -- as well as with radar facilities at NASA Jet Propulsion Laboratory's Goldstone planetary radar in California and the National Science Foundation's Green Bank Observatory in West Virginia. They are updating the period measurement with frequent observations to improve its precision.

Focus now is shifting toward measuring the efficiency of momentum transfer from DART's roughly 14,000-mile (22,530-kilometer) per hour collision with its target. This includes further analysis of the "ejecta" -- the many tons of asteroidal rock displaced and launched into space by the impact. The recoil from this blast of debris substantially enhanced DART's push against Dimorphos -- a little like a jet of air streaming out of a balloon sends the balloon in the opposite direction.

To successfully understand the effect of the recoil from the ejecta, more information on of the asteroid's physical properties, such as the characteristics of its surface, and how strong or weak it is, is needed. These issues are still being investigated.

"DART has given us some fascinating data about both asteroid properties and the effectiveness of a kinetic impactor as a planetary defense technology," said Nancy Chabot, the DART coordination lead from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. "The DART team is continuing to work on this rich dataset to fully understand this first planetary defense test of asteroid deflection."

For this analysis, astronomers will continue to study imagery of Dimorphos from DART's terminal approach and from the Light Italian CubeSat for Imaging of Asteroids (LICIACube), provided by the Italian Space Agency, to approximate the asteroid's mass and shape. Roughly four years from now, the European Space Agency's Hera project is also planned to conduct detailed surveys of both Dimorphos and Didymos, with a particular focus on the crater left by DART's collision and a precise measurement of Dimorphos' mass.

Johns Hopkins APL built and operated the DART spacecraft and manages the DART mission for NASA's Planetary Defense Coordination Office as a project of the agency's Planetary Missions Program Office. Telescopic facilities contributing to the observations used by the DART team to determine this result include: Goldstone, Green Bank Observatory, Swope Telescope at the Las Campanas Observatory in Chile, the Danish Telescope at the La Silla Observatory in Chile, and the Las Cumbres Observatory global telescope network facilities in Chile and in South Africa.

Read more at Science Daily

Learning about the first animals on Earth from life at the poles

The amazing survival strategies of polar marine creatures might help to explain how the first animals on Earth could have evolved earlier than the oldest fossils suggest according to new research. These first, simple and now extinct, animals might have lived through some of the most extreme, cold and icy periods the world has ever seen. The study is published in the journal Global Change Biology, published this week (12 October 2022).

The fossil record places the earliest animal life on Earth at 572-602 million years ago, just as the world came out of a huge ice age, whilst molecular studies suggest an earlier origin, up to 850 million years ago. If correct, this means that animals must have survived during a time influenced by multiple global ice ages, when the whole or large parts of the planet were encased in ice (snowball and slushball Earths), far bigger than any seen since. If animal life did arise before, or during, these extreme glacial periods it would have faced conditions like modern marine habitats found in Antarctica and the Arctic today, and required similar survival strategies.

Over millions of years, the expansion and contraction of the ice sheets during cold and warm periods has driven the evolution of Antarctica's thousands of unique animals and plant species. The same could be true for the evolution of animal life on Earth. Whilst to humans the polar regions seem like the most hostile environments to life, they are the perfect place to study the past and the potential for life in the universe beyond our planet, such as on icy moons like Europa.

Marine biologist and lead author, Dr Huw Griffiths of British Antarctic Survey (BAS), says:

"This work highlights how some animals in the polar regions are incredibly adapted to life in and around the ice, and how much they can teach us about the evolution and survival of life in the past or even on other planets.

"Whether it is animals living upside down on the underside of ice instead of the seafloor, sponges living hundreds of kilometres under thick floating ice shelves, organisms that are adapted to live in seawater colder than ?2°C, or whole communities existing in the darkness on food sources that don't require sunlight, Antarctic and Arctic life thrives in conditions that would kill humans and most other animals. But these cold and icy conditions help to drive ocean circulation, carry oxygen into the ocean depths and make these places more suitable for life."

Floating ice covers more than 19 million km2 of the seas around Antarctica and 15 million km2 of the Arctic Ocean during winter. Under possibly the most extreme snowball Earth, lasting 50 to 60 million years during the Cryogenian period (720 to 635?million years ago), the whole world (510 million km²) is believed to have been entombed in ice around a kilometre thick, but there is some evidence that this ice was thin enough at the equator to allow marine algae to survive.

"The fact that there is this huge difference in the timing of the dawn of animal life between the known fossil record and molecular clocks means that there are huge uncertainties about how and where animals evolved" says co-author Dr Emily Mitchell, palaeontologist and ecologist at the University of Cambridge. "But if animals did evolve before or during these global ice ages, they would have to contend with extreme environmental pressures, but ones that may have helped to force life to become more complex to survive."

"Just like in Antarctica during the Last Glacial Maximum (33-14 thousand years ago), the huge amounts of advancing ice would have bulldozed the shallows, making them inhospitable to life, destroying fossil evidence and forcing creatures into the deep sea. This makes the chances of finding fossils from these times less likely and sheltered areas and the deep sea the safest places for life to evolve."

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Professors call for more research into climate-change related threats to civilization

An opinion piece published today in the Proceedings of the National Academy of Sciences, a peer-reviewed journal of the National Academy of Sciences, urgently calls for more research into the specific pathways by which civilization could potentially collapse due to climate change.

"Scientists have warned that climate change threatens the habitability of large regions of the Earth and even civilization itself, but surprisingly little research exists about how collapse could happen and what can be done to prevent it," says Dr. Daniel Steel of the School of Population and Public Health at the University of British Columbia.

"A better understanding of the risks of collapse is essential for climate ethics and policy."

In the article, Dr. Steel and his colleagues, Dr. C. Tyler DesRoches with Arizona State University's School of Sustainability and Dr. Kian Mintz-Woo from University College Cork, define civilization collapse as the loss of societal capacity to maintain essential governance functions, especially maintaining security, the rule of law, and the provision of basic necessities such as food and water.

The co-authors consider three civilization collapse scenarios:

1.     localized collapse of specific, vulnerable locations;
2.     the collapse of some urban and national areas while the remaining ones experience detrimental climate-related effects such as food and water scarcity;
3.     global collapse where urban areas around the world are abandoned, nations are no more, and global population falls.

It is not only the direct effects of climate change -- such as drought, flooding, and extreme heat -- that could create collapse risks, but also less-studied mechanisms.

As Dr. Steel and his co-authors explain, climate change may also have indirect effects on systems like trade and international cooperation, which might in turn lead to political conflict, dysfunction, and war. The authors also state that these effects may lessen civilizations' adaptability which would leave them vulnerable to other shocks, like pandemics.

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After stroke in an infant's brain, right side of brain compensates for loss of language in left side

A clinical study conducted by researchers at Georgetown University Medical Center found that, for children who had a major stroke to the left hemisphere of their brain within days of their birth, the infant's brain was 'plastic' enough for the right hemisphere to acquire the language abilities ordinarily handled by the left side while also maintaining its own language abilities as well.

The left hemisphere of the brain is normally responsible for sentence processing (understanding words and sentences as we listen to speech). The right hemisphere of the brain is normally responsible for processing the emotion of the voice -- is it happy or sad, angry or calm. This study sought to answer the question "what happens when one of the hemispheres is injured at birth?"

The findings appear in PNAS the week of October 10, 2022.

The participants in this study developed normally during pregnancy. But around birth they had a significant stroke, one that would have debilitating outcomes in adults. In infants, a stroke is much rarer but does happen in roughly one out of every four thousand births.

The researchers studied perinatal arterial ischemic stroke, a type of brain injury occurring around the time of birth in which blood flow is cut off to a part of the brain by a blood clot. The same type of stroke occurs much more commonly in adults. Previous studies of brain injury in infants have included several types of brain injury, but the focus in this study on a specific type of injury enabled the authors to find more consistent effects than in previous work.

"Our most important conclusion is that plasticity in the brain, specifically the ability to reorganize language to the opposite side of the brain, is definitely possible early in life," says Elissa Newport, Ph.D., director of the Center for Brain Plasticity and Recovery at Georgetown Medical Center, professor in the departments of Neurology and Rehabilitation Medicine and first author of this study. "However, this early plasticity for language is restricted to one brain region. The brain is not able to reorganize injured functions just anywhere as more dramatic reorganization is not possible even in early life. This gives us great insights into the regions we might be able to focus on for potential breakthroughs in developing techniques for recovery in adults as well."

The investigators recruited people from across the United States who all had medium to large strokes to the cortex region of their left hemisphere around the time of birth. To assess long-term outcomes in their language abilities, participants were given language tests at 9 to 26 years of age and were compared to their close-in-age healthy siblings. They were also scanned in an MRI to reveal which brain areas were involved in sentence comprehension.

The participants and their healthy siblings all completed the language tasks almost perfectly. The major difference was that the stroke participants processed sentences on the right side of the brain while their siblings processed sentences on the left side. The stroke participants showed a very consistent pattern of language activation in the right hemisphere, regardless of the extent or location of damage from the stroke to the left hemisphere. Only one of the 15 participants, who had the smallest stroke, did not show clear right hemisphere dominant activation.

"It is also notable that many years after their strokes our participants are all such highly functioning adults. Some are honor students and others are working toward or have gotten their master's degrees," says Newport. "Their achievements are remarkable, especially since some of their parents had been told when they were born that their strokes would produce life-long impairments."

Read more at Science Daily

Unprecedented levels of insects damaging plants

Insects today are causing unprecedented levels of damage to plants, even as insect numbers decline, according to new research led by University of Wyoming scientists.

The first-of-its-kind study compares insect herbivore damage of modern-era plants with that of fossilized leaves from as far back as the Late Cretaceous period, nearly 67 million years ago. The findings appear in the  journal Proceedings of the National Academy of Sciences.

"Our work bridges the gap between those who use fossils to study plant-insect interactions over deep time and those who study such interactions in a modern context with fresh leaf material," says the lead researcher, UW Ph.D. graduate Lauren Azevedo-Schmidt, now a postdoctoral research associate at the University of Maine. "The difference in insect damage between the modern era and the fossilized record is striking."

Azevedo-Schmidt conducted the research along with UW Department of Botany and Department of Geology and Geophysics Professor Ellen Currano, and Assistant Professor Emily Meineke of the University of California-Davis.

The study examined fossilized leaves with insect feeding damage from the Late Cretaceous through the Pleistocene era, a little over 2 million years ago, and compared them with leaves collected by Azevedo-Schmidt from three modern forests. The detailed research looked at different types of damage caused by insects, finding marked increases in all recent damage compared to the fossil record.

"Our results demonstrate that plants in the modern era are experiencing unprecedented levels of insect damage, despite widespread insect declines," wrote the scientists, who suggest that the disparity can be explained by human activity.

More research is necessary to determine the precise causes of increased insect damage to plants, but the scientists say a warming climate, urbanization and introduction of invasive species likely have had a major impact.

"We hypothesize that humans have influenced (insect) damage frequencies and diversities within modern forests, with the most human impact occurring after the Industrial Revolution," the researchers wrote. "Consistent with this hypothesis, herbarium specimens from the early 2000s were 23 percent more likely to have insect damage than specimens collected in the early 1900s, a pattern that has been linked to climate warming."

Read more at Science Daily

Scientists hit their creative peak early in their careers

A new study provides the best evidence to date that scientists overall are most innovative and creative early in their careers.

Findings showed that, on one important measure, the impact of biomedical scientists' published work drops by between one-half to two-thirds over the course of their careers.

"That's a huge decline in impact," said Bruce Weinberg, co-author of the study and professor of economics at The Ohio State University.

"We found that as they get older, the work of biomedical scientists was just not as innovative and impactful."

But the reasons behind this trend of declining innovativeness make the findings more nuanced and show why it is still important to support scientists later in their careers, Weinberg said.

The study was published online Oct. 7, 2022 in the Journal of Human Resources.

Researchers have been studying the relationship between age or experience with innovativeness for nearly 150 years, but no consensus has emerged. Findings, in fact, have been "all over the map," Weinberg said.

"For a topic that so many people with so many approaches have studied for so long, it is pretty remarkable that we still don't have a conclusive answer."

One advantage of this study is that the authors had a huge dataset to work with -- 5.6 million biomedical science articles published over a 30-year period, from 1980 to 2009, and compiled by MEDLINE. These data include detailed information on the authors.

This new study measured the innovativeness of the articles by biomedical scientists using a standard method -- the number of times other scientists mention (or "cite") a study in their own work. The more times a study is cited, the more important it is thought to be.

With detailed information on the authors of each paper, the researchers in this study were able to compare how often scientists' work was cited early in their careers compared to later in their careers.

As they analyzed the data, Weinberg and his colleagues made a discovery that was a key to understanding how innovation changes over a career.

They found that scientists who were the least innovative early in their careers tended to drop out of the field and quit publishing new research. It was the most productive, the most important young scholars who were continuing to produce research 20 or 30 years later.

"Early in their careers, scientists show a wide range of innovativeness. But over time, we see selective attrition of the people who are less innovative," Weinberg said.

"So when you look at all biomedical scientists as a group, it doesn't look like innovation is declining over time. But the fact that the least innovative researchers are dropping out when they are relatively young disguises the fact that, for any one person, innovativeness tends to decline over their career."

Results showed that for the average researcher, a scientific article they published late in their career was cited one-half to two-thirds less often than an article published early in their careers.

But it wasn't just citation counts that suggest researchers were less innovative later in their career.

"We constructed additional metrics that captured the breadth of an article's impact based on the range of fields that cite it, whether the article is employing the best and latest ideas, citing the best and latest research, and whether the article is drawing from multiple disciplines," said Huifeng Yu, a co-author, who worked on the study as a PhD student at the University at Albany, SUNY.

"These other metrics also lead to the same conclusion about declining innovativeness."

The findings showing selective attrition among less-innovative scientists can help explain why previous studies have had such conflicting results, Weinberg said.

Studies using Nobel Laureates and other eminent researchers, for whom attrition is relatively small, tend to find earlier peak ages for innovation. In contrast, studies using broader cross-sections of scientists don't normally find an early peak in creativity, because they don't account for the attrition.

Weinberg noted that attrition in the scientific community may not relate only to innovativeness. Scientists who are women or from underrepresented minorities may not have had the opportunities they needed to succeed, although this study can't quantify that effect.

"Those scientists who succeeded probably did so through a combination of talent, luck, personal background and prior training," he said.

The findings suggest that organizations that fund scientists have to maintain a delicate balance between supporting youth and experience.

"Young scientists tend to be at their peak of creativity, but there is also a big mix with some being much more innovative than others. You may not be supporting the very best researchers," said Gerald Marschke, a co-author of the study and associate professor of economics at the University at Albany,

"With older, more experienced scientists, you are getting the ones who have stood the test of time, but who on average are not at their best anymore."

Read more at Science Daily

Impact that killed the dinosaurs triggered 'mega-earthquake' that lasted weeks to months

66 million years ago, a 10-kilometer asteroid hit Earth, triggering the extinction of the dinosaurs. New evidence suggests that the Chicxulub impact also triggered an earthquake so massive that it shook the planet for weeks to months after the collision. The amount of energy released in this "mega-earthquake" is estimated at 1023 joules, which is about 50,000 times more energy than was released in the magnitude 9.1 Sumatra earthquake in 2004.

Hermann Bermúdez will present evidence of this "mega-earthquake" at the upcoming GSA Connects meeting in Denver this Sunday, 9 October. Earlier this year, with support from a GSA Graduate Student Research Grant, Bermúdez visited outcrops of the infamous Cretaceous-Paleogene (K-Pg) mass extinction event boundary in Texas, Alabama, and Mississippi to collect data, supplementing his previous work in Colombia and Mexico documenting evidence of the catastrophic impact.

In 2014, while doing fieldwork on Colombia's Gorgonilla Island, Bermúdez found spherule deposits -- layers of sediment filled with small glass beads (as large as 1.1 mm) and shards known as 'tektites' and 'microtektites' that were ejected into the atmosphere during an asteroid impact. These glass beads formed when the heat and pressure of the impact melted and scattered the crust of the Earth, ejecting small, melted blobs up into the atmosphere, to then fall back to the surface as glass under the influence of gravity.

The rocks exposed on the coast of Gorgonilla Island tell a story from the bottom of the ocean -- roughly 2 km down. There, about 3,000-km southwest from the site of the impact, sand, mud, and small ocean creatures were accumulating on the ocean floor when the asteroid hit. Layers of mud and sandstone as far as 10-15 meters below the sea floor experienced soft-sediment deformation that is preserved in the outcrops today, which Bermúdez attributes to the shaking from the impact. Faults and deformation due to shaking continue up through the spherule-rich layer that was deposited post-impact, indicating that the shaking must have continued for the weeks and months it took for these finer-grained deposits to reach the ocean floor. Just above those spherule deposits, preserved fern spores signal the first recovery of plant-life after the impact.

Bermúdez explains, "The section I discovered on Gorgonilla Island is a fantastic place to study the K-Pg boundary, because it is one of the best-preserved and it was located deep in the ocean, so it was not affected by tsunamis."

Evidence of deformation from the mega-earthquake is also preserved in Mexico and the United States. At the El Papalote exposure in Mexico, Bermúdez observed evidence of liquefaction -- when strong shaking causes water-saturated sediments to flow like a liquid. In Mississippi, Alabama, and Texas, Bermúdez documented faults and cracks likely associated with the mega-quake. He also documents tsunami deposits at several outcrops, left by an enormous wave that was part of the cascading catastrophes resulting from the asteroid collision.

Bermúdez will deliver a talk about evidence for the mega-earthquake at the GSA Connects meeting in Denver on Sunday, 9 October. He will also present a poster about his observations of tsunami deposits and earthquake-related deformation on Monday, 10 October, which will be available in English, Spanish, Italian, French, and Chinese. In discussing his research, he emphasized the important role collaboration has played in visiting and studying so many outcrops that tell the story of this extreme event in Earth's history.

Read more at Science Daily

Why the Salton Sea is turning into toxic dust

The Salton Sea, California's most polluted inland lake, has lost a third of its water in the last 25 years. New research has determined a decline in Colorado River flow is the reason for that shrinking.

As the lake dries up, the concentration of salt and chemicals in the remaining water has increased dramatically, causing a mass die-off of fish and birds, including endangered species. The dry lakebed, coated in the salty, toxic water, becomes dust that causes respiratory problems for nearby residents.

"It is an environmental catastrophe," said Juan S. Acero Triana, UCR hydrologist and lead author of a new study focused on understanding water movement on and below Earth's surface near the Salton Sea, a research field called hydrology. The study was funded by the National Science Foundation's Innovation at the Nexus of Food, Energy and Water Systems, or INFEWS, program.

There have been a variety of hypotheses about why the water levels are steadily declining. Some blame climate change and heat for drying up the lake. Others suspect that agriculture could be to blame. As irrigation systems get more efficient and crops are modified to use less water, it means less water getting into the Salton Sea. However, the researchers say these are not the biggest causes of the sea's decline.

"There is less water coming from the Colorado River into the Sea, and that is driving the problem," said Hoori Ajami, UCR hydrologist, study co-author and principal investigator. This finding, and the methods used to obtain it, are now published in the journal Water Resources Research.

The researchers considered all major processes impacting the water balance of an endorheic lake like the Salton Sea, where water flows in but not out to any tributaries. Endorheic lakes worldwide have been shrinking in recent decades at what the researchers call an "alarming" rate due to the combined effects of global warming and diversion of water for agricultural and industrial purposes.

To understand the reasons for the Salton Sea's decline, the researchers used a hydrologic model that accounted for all processes in the surrounding areas that impact the lake's water balance, including climate, soil types, land slope, and plant growth.

Geographically the model included data not only about the Sea itself, but also from the surrounding watershed, streams entering the lake, and the land area that drains into those streams.

Data for the model was hard to come by as this is a transboundary basin on the US-Mexico border between California and Baja California Norte, and stakeholders may have been reluctant to share data that could alter previously earned water rights. However, using publicly available data and data mining techniques, UCR researchers were able to simulate long-term water balance dynamics and identify reduced Colorado River flows as the main cause of the Salton Sea shrinking.

"It's not entirely clear, however, whether the decline in Colorado River water is more due to global warming drying out the river, or reductions in allocation levels to California, or both," Acero Triana said.

Despite that lingering ambiguity, the researchers say the study should send a message to water management agencies and lawmakers that the Salton Sea watershed should be considered part of the Colorado River basin.

Read more at Science Daily

Positive childhood experiences of blue spaces linked to better adult well-being

New research based on data from 18 countries concludes that adults with better mental health are more likely to report having spent time playing in and around coastal and inland waters, such as rivers and lakes (also known collectively as blue spaces) as children. The finding was replicated in each of the countries studied.

Mounting evidence shows that spending time in and around green spaces such as parks and woodlands in adulthood is associated with stress reduction and better mental health. However, we know far less about the benefits of blue spaces, or the role childhood contact has in these relationships in later life.

Data came from the BlueHealth International Survey (BIS), a cross-sectional survey co-ordinated by the University of Exeter's European Centre for Environment and Human Health. The current analysis used data from over 15,000 people across 14 European Countries and 4 other non-European countries/regions (Hong Kong, Canada, Australia and California).

Respondents were asked to recall their blue space experiences between the ages of 0-16 years including how local they were, how often they visited them, and how comfortable their parents/guardians were with them playing in these settings, as well as more recent contact with green and blue spaces over the last four weeks, and mental health over the last two weeks.

The research, published in the Journal of Environmental Psychology, found that individuals who recalled more childhood blue space experiences tended to place greater intrinsic value on natural settings in general, and to visit them more often as adults -- each of which, in turn, were associated with better mental wellbeing in adulthood.

Valeria Vitale, Lead author and PhD Candidate at Sapienza University of Rome, said: "In the context of an increasingly technological and industrialized world, it's important to understand how childhood nature experiences relate to wellbeing in later life.

"Our findings suggest that building familiarity and confidence in and around blue spaces during childhood may stimulate an inherent joy of nature and encourage people to seek out recreational nature experiences, with beneficial consequences for adult mental health."

Dr Leanne Martin, Co-author and Postdoctoral Research Associate at the University of Exeter's European Centre for Environment and Human Health, said: "Water settings can be dangerous for children, and parents are right to be cautious. This research suggests though that supporting children to feel comfortable in these settings and developing skills such as swimming at an early age can have previously unrecognised life-long benefits."

Dr Mathew White, Co-author and Senior Scientist at the University of Vienna, said: "The current study is adding to our growing awareness of the need for urban planners and local bodies responsible for managing our green and blue spaces to provide safe, accessible access to natural settings for the healthy mental and physical development of our children.

"If our findings are supported by longitudinal research that tracks people's exposures over the entire life-course, it would suggest that further work, policies and initiatives encouraging more blue space experiences during childhood may be a viable way to support the mental health of future generations."

Read more at Science Daily

Turning the spotlight on cells in tissues so RNA can tell their story

A new advance overcomes present limitations in spatial transcriptomics with a DNA nanotechnology-driven method called 'Light-Seq.' Light-Seq allows researchers to 'geotag' the full repertoire of RNA sequences with unique DNA barcodes exclusive to a few cells of interest. These target cells are selected using light under a microscope via a fast and effective photocrosslinking process, and their RNAs made available to next-generation sequencing with the help of a new DNA nanotechnology-driven technique. This entire process can then be repeated for different cell populations in the same sample.

Under the microscope, researchers often observe different cell types organizing themselves in peculiar patterns within tissues, or sometimes a rare cell type that stands out by occupying a unique position, exhibiting an unusual shape, or expressing a specific biomarker molecule. To determine the deeper meaning of their observations, they have developed approaches to also access cells' gene expression patterns (transcriptomes) by analyzing the gene-derived RNA molecules present within them, which they can match with cells' shapes, spatial positions, and molecular biomarkers.

However, these "spatial transcriptomics" approaches still only capture a fraction of a cell's total RNA molecules, and cannot deliver the depth and quality of analysis provided by single-cell sequencing methods, which were developed to investigate the transcriptomes of individual cells isolated from tissues or biofluids via next-generation sequencing (NGS) techniques. Nor do they allow researchers to only home in on specific cells based on their location in a tissue, which would greatly facilitate the pursuit of disjointed cell populations, or rare, difficult-to-isolate cells like rare brain cells with unique functions, or immune cells that invade tumors. In addition, because the original tissue environment is disrupted, many spatial transcriptomics and all single-cell sequencing methods prevent researchers from revisiting their samples to perform follow-up analysis, and they are costly because they require specialized instruments or reagents.

A new advance made at the Wyss Institute for Biologically Inspired Engineering at Harvard University now overcomes these limitations with a DNA nanotechnology-driven method called "Light-Seq." Light-Seq allows researchers to "geotag" the full repertoire of RNA sequences with unique DNA barcodes exclusive to a few cells of interest. These target cells are selected using light under a microscope via a fast and effective photocrosslinking process.

With the help of a new DNA nanotechnology, the barcoded RNA sequences are then translated into coherent DNA strands, which can then be collected from the tissue sample and identified using NGS. The Light-Seq process can be repeated with different barcodes for different cell populations within the same sample, which is left intact for follow-up analysis. With a performance comparable to single-cell sequencing methods, it significantly broadens the depth and scope of investigations possible on a tissue sample. The method is published in Nature Methods[BB1] .

"Light-Seq's unique combination of features fills an unmet need: the ability to perform imaging-informed, spatially prescribed, deep-sequencing analysis of hard, if not impossible-to-isolate cell populations or rare cell types in preserved tissues, with one-to-one correspondence of their highly refined gene expression state with spatial, morphological, and potentially disease-relevant features," said Peng Yin, Ph.D., one of four corresponding authors and a Core Faculty member at the Wyss Institute, where his group developed Light-Seq. "It thus has potential to fast-forward the biological discovery process in various biomedical research areas." Yin is also a Professor of Systems Biology at Harvard Medical School (HMS).

From barcoding in situ to sequencing ex situ

The Light-Seq project was spearheaded by Jocelyn (Josie) Kishi, Ph.D., Sinem Saka, Ph.D., and Ninning Liu, Ph.D. in Yin's group at the Wyss, and Emma West, Ph.D. in Constance Cepko's lab at HMS. Previously, Kishi and Saka had developed SABER-FISH as a spatial transcriptomics method for imaging gene expression directly in intact tissues (in situ). "With SABER-FISH, we still were orders of magnitude away from capturing cells' complete gene expression programs, with many thousands of different RNA molecules per cell. RNA molecules are just too densely packed to be captured in their entirety using present imaging techniques," said co-first and co-corresponding author Kishi. "Light-Seq solves this problem by combining high-resolution barcode labeling with full-transcriptome sequencing via NGS, giving us the best of both worlds and additional key advantages." At the time of the study, Kishi was a Wyss Technology Development Fellow on Yin's team, and is now pursuing a path toward commercializing Light-Seq together with some of her co-authors.

"To specifically sequence the cells in custom-selected locations of intact tissue samples, we developed a new approach for photocrosslinking DNA barcodes to copies of RNA molecules, and a DNA nanotechnology-powered procedure that makes them and their attached RNA sequences readable by NGS," said co-first author Liu, a Postdoctoral Fellow in Yin's group who previously co-developed a parallelized DNA barcoding platform for a super-resolution imaging method called "Action-PAINT" that also became one of the core components of Light-Seq.

First, DNA primers "base-pair" with RNA molecules in cells, and are extended to create copies of the RNA sequences called complementary DNA sequences (cDNAs). Then, DNA barcode strands containing an ultrafast photocrosslinker nucleotide are in turn base-paired to the cDNAs in the cells. These become permanently linked together when a target cell is lit up under the microscope through a stencil-like optical device that keeps other, non-target cells in the microscopic field in the dark and thus spares them from the photocrosslinking reaction. After washing the barcoded DNA sequences out of cells that were not permanently linked in situ, the procedure can be repeated with different barcodes and light patterns to label more regions of interest.

"To be able to integrate this barcoding workflow with NGS, we engineered a new stitching reaction that is based on DNA nanotechnology. This innovation allows us to convert our barcoded cDNAs into contiguous readout sequences. We can then extract the complete collection of barcode-bearing cDNA sequences from the sample, and analyze them with standard NGS techniques," explained Saka, one of the study's corresponding authors who is currently a Group Leader at the European Molecular Biology Laboratory in Heidelberg, Germany. "Ultimately, each barcode traces the full transcriptome readout back to the pre-selected cells in the tissue sample, which remains intact for subsequent analyses. This provides us the unique chance to revisit the exact same cells after sequencing for validation or further exploration."

Eying complex tissues and rare cells

Following the first validation of Light-Seq in cultured cells, Yin's team wanted to apply it to a complex tissue and partnered up with the group of Constance Cepko, Ph.D. at HMS. Cepko is one of the study's corresponding authors and the Bullard Professor of Genetics and Neuroscience in the Blavatnik Institute at HMS, and investigates the development of the retina as a model of the nervous system. Kishi, Saka, and Liu joined forces with West in Cepko's group to apply Light-Seq to cross-sections of the mouse retina and profile three major layers with different functions. The researchers reached a sequence coverage comparable to single-cell sequencing methods, and found that thousands of RNAs were enriched between the retina's three major layers. They also showed that after sequence extraction, the tissue samples remained intact and could be further imaged for proteins and other biomolecules.

"Taking Light-Seq to the extreme, we were able to isolate the full transcriptome of a very rare cell type, known as 'dopaminergic amacrine cells' (DACs), which is extremely hard to isolate because of its intricate connections to other cells in the retina, by retrieving merely four to eight individually barcoded cells per cross-section," said West. DACs are involved in regulating the eye's circadian rhythm by fine-tuning visual perception to different light exposures during the day-night cycle. "Light-Seq also picked up RNAs that were specifically expressed in DACs at low levels, as well as dozens of DAC-specific biomarker RNAs that, to our knowledge, had not been described before, which opens new opportunities to study this rare cell type," added West, who at the time of the study was a graduate student and then Postdoctoral Fellow with Cepko, and has now joined Kishi in her Light-Seq commercialization effort.

Opening the field of spatial transcriptomics up to NGS also adds information on the level of a single RNA species. "Our sequencing data clearly showed that Light-Seq can determine natural variations in the structure of RNAs. Going forward, we're very interested in using Light-Seq to better understand the interplay between the immune system, disease-propagating cells, and different therapeutic strategies such as gene and cell therapy," said Kishi.

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Eye-opening discovery about adult brain's ability to recover vision

A discovery about how some visually impaired adults could start to see offers a new vision of the brain's possibilities. The finding that the adult brain has the potential to partially recover from inherited blindness comes from a collaboration between researchers in the University of California, Irvine School of Biological Sciences and the School of Medicine. Their paper appears in Current Biology.

The team was examining treatment for Leber congenital amaurosis, known as LCA. The term refers to a group of inherited retinal diseases distinguished by severe visual impairment at birth. The condition, which stems from mutations in any of over two dozen genes, causes degeneration or dysfunction in the retina's photoreceptors.

Administering chemical compounds that target the retina, called synthetic retinoids, can restore a notable amount of vision in children with LCA. The UCI team wanted to find out if the treatment could make a difference for adults who have the condition.

"Frankly, we were blown away by how much the treatment rescued brain circuits involved in vision," said Sunil Gandhi, professor of neurobiology and behavior and the corresponding author. Gandhi is a fellow of UCI's Center for the Neurobiology of Learning and Memory and a member of the Center for Translational Vision Research. "Seeing involves more than intact and functioning retinae. It starts in the eye, which sends signals throughout the brain. It's in the central circuits of the brain where visual perception actually arises." Until now, scientists believed that the brain must receive those signals in childhood so that central circuits could wire themselves correctly.

Working with rodent models of LCA, the collaborators were surprised by what they found. "The central visual pathway signaling was significantly restored in adults, especially the circuits that deal with information coming from both eyes," Gandhi said. "Immediately after the treatment, the signals coming from the opposite-side eye, which is the dominant pathway in the mouse, activated two times more neurons in the brain. What was even more mind-blowing was that the signals coming from the same-side eye pathway activated five-fold more neurons in the brain after the treatment and this impressive effect was long-lasting. The restoration of visual function at the level of the brain was much greater than expected from the improvements we saw at the level of the retinae. The fact that this treatment works so well in the central visual pathway in adulthood supports a new concept, which is that there is latent potential for vision that is just waiting to be triggered."

The finding opens exciting research possibilities. "Whenever you have a discovery that breaks with your expectations about the possibility for the brain to adapt and rewire, it teaches you a broader concept," Gandhi said. "This new paradigm could aid in the development of retinoid therapies to more completely rescue the central visual pathway of adults with this condition."

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Age vs. genetics: Which is more important for determining how we age?

Amid much speculation and research about how our genetics affect the way we age, a University of California, Berkeley, study now shows that individual differences in our DNA matter less as we get older and become prone to diseases of aging, such as diabetes and cancer.

In a study of the relative effects of genetics, aging and the environment on how some 20,000 human genes are expressed, the researchers found that aging and environment are far more important than genetic variation in affecting the expression profiles of many of our genes as we get older. The level at which genes are expressed -- that is, ratcheted up or down in activity -- determines everything from our hormone levels and metabolism to the mobilization of enzymes that repair the body.

"How do your genetics -- what you got from your sperm donor and your egg donor and your evolutionary history -- influence who you are, your phenotype, such as your height, your weight, whether or not you have heart disease?" said Peter Sudmant, UC Berkeley assistant professor of integrative biology and a member of the campus's Center for Computational Biology. "There's been a huge amount of work done in human genetics to understand how genes are turned on and off by human genetic variation. Our project came about by asking, 'How is that influenced by an individual's age?' And the first result we found was that your genetics actually matter less the older you get."

In other words, while our individual genetic makeup can help predict gene expression when we are younger, it is less useful in predicting which genes are ramped up or down when we're older -- in this study, older than 55 years. Identical twins, for example, have the same set of genes, but as they age, their gene expression profiles diverge, meaning that twins can age much differently from each other.

The findings have implications for efforts to correlate diseases of aging with genetic variation in humans, Sudmant said. Such studies should perhaps focus less on genetic variants that impact gene expression when pursuing drug targets.

"Almost all human common diseases are diseases of aging: Alzheimer's, cancers, heart disease, diabetes. All of these diseases increase their prevalence with age," he said. "Massive amounts of public resources have gone into identifying genetic variants that predispose you to these diseases. What our study is showing is that, well, actually, as you get older, genes kind of matter less for your gene expression. And so, perhaps, we need to be mindful of that when we're trying to identify the causes of these diseases of aging."

Sudmant and his colleagues reported their results this week in the journal Nature Communications.

Medawar's hypothesis

The findings are in line with Medawar's hypothesis: Genes that are turned on when we are young are more constrained by evolution because they are critical to making sure we survive to reproduce, while genes expressed after we reach reproductive age are under less evolutionary pressure. So, one would expect a lot more variation in how genes are expressed later in life.

"We're all aging in different ways," Sudmant said. "While young individuals are closer together in terms of gene expression patterns, older individuals are further apart. It's like a drift through time as gene expression patterns become more and more erratic."

This study is the first to look at both aging and gene expression across such a wide variety of tissues and individuals, Sudmant said. He and his colleagues built a statistical model to assess the relative roles of genetics and aging in 27 different human tissues from nearly 1,000 individuals and found that the impact of aging varies widely -- more than twentyfold -- among tissues.

"Across all the tissues in your body, genetics matters about the same amount. It doesn't seem like it plays more of a role in one tissue or another tissue," he said. "But aging is vastly different between different tissues. In your blood, colon, arteries, esophagus, fat tissue, age plays a much stronger role than your genetics in driving your gene expression patterns."

Sudmant and colleagues also found that Medawar's hypothesis does not hold true for all tissues. Surprisingly, in five types of tissues, evolutionary important genes were expressed at higher levels in older individuals.

"From an evolutionary perspective, it is counterintuitive that these genes should be getting turned on, until you take a close look at these tissues," Sudmant said. These five tissues happen to be the ones that constantly turn over throughout our lifespan and also produce the most cancers. Every time these tissues replace themselves, they risk creating a genetic mutation that can lead to disease.

"I guess this tells us a little bit about the limits of evolution," he said. "Your blood, for instance, always has to proliferate for you to live, and so these super-conserved, very important genes have to be turned on late in life. This is problematic because it means that those genes are going to be susceptible to getting somatic mutations and getting turned on forever in a bad, cancerous way. So, it kind of gives us a little bit of a perspective on what the limitations of living are like. It puts bounds on our ability to keep living."

Sudmant noted that the study indirectly indicates the effect on aging of one's environment, which is the impact of everything other than age and genetics: the air we breathe, the water we drink, the food we eat, but also our levels of physical exercise. Environment amounts to up to a third of gene expression changes with age.

Sudmant is conducting similar analyses of the expressed genes in several other organisms -- bats and mice -- to see how they differ and whether the differences are related to these animals' different lifespans.

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