Astronomers conduct first search for forming planets with new space telescope

Planets form in disks of dust and gas called protoplanetary disks that whirl around a central protostar during its final assembly.

Although several dozens of such disks have been imaged, just two planets have been caught in the act of forming so far. Now, astronomers are aiming the powerful instruments aboard the James Webb Space Telescope at protoplanetary disks to try to find early clues about the ways in which planets form, and how these planets influence their natal disk.

A trio of studies led by the University of Michigan, University of Arizona and University of Victoria combined JWST's images with prior observations made by the Hubble Space Telescope and the Atacama Large Millimeter Array, or ALMA, in Chile. Based on the ancillary observations, the team used JWST to observe protoplanetary disks HL Tau, SAO 206462 and MWC 758 in hopes of detecting any planets that might be forming.

In the papers, published in The Astronomical Journal, the researchers pieced together previously unseen interactions between the planet-forming disk and the envelope of gas and dust surrounding the young stars at the center of the protoplanetary disks.

To catch a planet

The U-M study, led by U-M astronomer Gabriele Cugno, aimed JWST at a disk surrounding a protostar called SAO 206462. There, the researchers potentially found a planet candidate in the act of forming in a protoplanetary disk -- but it wasn't the planet they expected to find.

"Several simulations suggest that the planet should be within the disk, massive, large, hot, and bright. But we didn't find it. This means that either the planet is much colder than we think, or it may be obscured by some material that prevents us from seeing it," said Cugno, also a co-author on all three papers. "What we have found is a different planet candidate, but we cannot tell with 100% certainty whether it's a planet or a faint background star or galaxy contaminating our image. Future observations will help us understand exactly what we are looking at."

Astronomers have observed the disk in the past, notably with the Hubble Space Telescope, the Subaru Telescope, the Very Large Telescope and ALMA. These observations show a disk composed of two strong spirals, which are likely launched by a forming planet. The planet the U-M team expected to find is a type called a gas giant, planets composed mainly of hydrogen and helium, similar to Jupiter in our own solar system.

"The problem is, whatever we're trying to detect is hundreds of thousands, if not millions of times fainter than the star," Cugno said. "That's like trying to detect a little light bulb next to a lighthouse."

To peer more closely into the disk, the team used an instrument on JWST called NIRCam. NIRCam detects infrared light, and the astronomers used the instrument employing a technique called angular differential imaging. This technique can be used to detect both the thermal radiation of the planet, as the team has done to detect the planet candidate, and specific emission lines associated with material falling onto the planet and hitting its surface with high velocity.

"When material falls onto the planet, it shocks at the surface and gives off an emission line at specific wavelengths," Cugno said. "We use a set of narrow-band filters to try to detect this accretion. This has been done before from the ground at optical wavelengths, but this is the first time it's been done in the infrared with JWST."

Imaging the 'raw material' of planets

The University of Victoria paper, led by astronomy student Camryn Mullin, describes images of the disk surrounding the young star HL Tau.

"HL Tau is the youngest system in our survey, and still surrounded by a dense inflow of dust and gas falling onto the disk," said Mullin, a co-author of all three studies. "We were amazed by the level of detail with which we could see this surrounding material with JWST, but unfortunately, it obscures any signals from potential planets. "

HL Tau's disk is known for having several solar-system scale rings and gaps which could harbor planets.

"While there is a ton of evidence for ongoing planet formation, HL Tau is too young with too much intervening dust to see the planets directly," said Jarron Leisenring, the principal investigator of the observing campaign searching for forming planets and astronomer at the University of Arizona Steward Observatory. "We have already begun looking at other young systems with known planets to help form a more complete picture."

However, to the team's surprise, JWST revealed unexpected details of a different feature: the proto-stellar envelope, which is essentially a dense inflow of dust and gas surrounding the young star that is just beginning to coalesce, according to Leisenring. Under the influence of gravity, material from the interstellar medium falls inward onto the star and the disk, where it serves as the raw material for planets and their precursors.

The UArizona study, led by Kevin Wagner, a NASA Hubble/Sagan Fellow at UArizona Steward Observatory, examined the protoplanetary disk of MWC 758. Similar to SAO 206462, previous observations by the UArizona-led team revealed spiral arms forming in the disk, hinting at a massive planet orbiting its host star.

While no new planets were detected in the disk during the most recent observations, the sensitivity is groundbreaking, the researchers say, as it allows them to place the most stringent constraints yet on the suspected planets. For one, the results rule out the existence of additional planets in the outer regions of the MWC 758, consistent with a single giant planet driving the spiral arms.

"The lack of planets detected in all three systems tells us that the planets causing the gaps and spiral arms either are too close to their host stars or too faint to be seen with JWST," said Wagner, a co-author of all three studies. "If the latter is true, it tells us that they're of relatively low mass, low temperature, enshrouded in dust, or some combination of the three -- as is likely the case in MWC 758."

The search for forming planets continues

Catching planets in the act of forming is important because astronomers can glean information not only about the formation process, but how chemical elements get distributed throughout a planetary system.

"Only about 15 percent of stars like the sun have planets like Jupiter. It's really important to understand how they form and evolve, and to refine our theories," said U-M Michael Meyer, U-M astronomer and coauthor of all three studies. "Some astronomers think that these gas giant planets regulate the delivery of water to rocky planets forming in the inner parts of the disks."

Knowing how these disks are shaped by gas giants will help astronomers ultimately understand the properties and evolution of protoplanetary disks that later give rise to rocky, Earth-like planets, said Meyer.

"Basically in every disk we have observed with high enough resolution and sensitivity, we have seen large structures like gaps, rings and, in the case of SAO 206462, spirals," Cugno said. "Most if not all of these structures can be explained by forming planets interacting with the disk material, but other explanations that do not involve the presence of giant planets exist.

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Land under water: What causes extreme flooding?

If rivers overflow their banks, the consequences can be devastating -- just like the catastrophic floods in North Rhine-Westphalia and Rhineland-Palatinate of 2021 showed. In order to limit flood damage and optimise flood risk assessment, we need to better understand what factors can lead to extreme forms of flooding and to what extent. Using methods of explainable machine learning, researchers at the Helmholtz Centre for Environmental Research (UFZ) have shown that floods are more extreme when several factors are involved in their development. The research was published in Science Advances.

There are several factors that play an important role in the development of floods: air temperature, soil moisture, snow depth, and the daily precipitation in the days before a flood. In order to better understand how individual factors contribute to flooding, UFZ researchers examined more than 3,500 river basins worldwide and analysed flood events between 1981 and 2020 for each of them. The result: precipitation was the sole determining factor in only around 25% of the almost 125,000 flood events. Soil moisture was the decisive factor in just over 10% of cases, and snow melt and air temperature were the sole factors in only around 3% of cases. In contrast, 51.6% of cases were caused by at least two factors. At around 23%, the combination of precipitation and soil moisture occurs most frequently.

However, when analysing the data, the UFZ researchers discovered that three -- or even all four -- factors can be jointly responsible for a flood event. For example, temperature, soil moisture, and snow depth were decisive factors in around 5,000 floods whilst all four factors were decisive in around 1,000 flood events. And not only that: "We also showed that flood events become more extreme when more factors are involved," says Dr Jakob Zscheischler, Head of the UFZ Department "Compound Environmental Risks" and senior author of the article. In the case of one-year floods, 51.6% can be attributed to several factors; in the case of five- and ten-year floods, 70.1% and 71.3% respectively can be attributed to several factors. The more extreme a flood is, the more driving factors there are and the more likely they are to interact in the event generation. This correlation often also applies to individual river basins and is referred to as flood complexity.

According to the researchers, river basins in the northern regions of Europe and America as well as in the Alpine region have a low flood complexity. This is because snow melt is the dominant factor for most floods regardless of the flood magnitude. The same applies to the Amazon basin, where the high soil moisture resulting from the rainy season is often a major cause of floods of varying severity. In Germany, the Havel and the Zusam, a tributary of the Danube in Bavaria, are river basins that have a low flood complexity. Regions with river basins that have a high flood complexity primarily include eastern Brazil, the Andes, eastern Australia, the Rocky Mountains up to the US west coast, and the western and central European plains. In Germany, this includes the Moselle and the upper reaches of the Elbe. "River basins in these regions generally have several flooding mechanisms," says Jakob Zscheischler. For example, river basins in the European plains can be affected by flooding caused by the combination of heavy precipitation, active snow melt, and high soil moisture.

However, the complexity of flood processes in a river basin also depends on the climate and land surface conditions in the respective river basin. This is because every river basin has its own special features. Among other things, the researchers looked at the climate moisture index, the soil texture, the forest cover, the size of the river basin, and the river gradient. "In drier regions, the mechanisms that lead to flooding tend to be more heterogeneous. For moderate floods, just a few days of heavy rainfall is usually enough. For extreme floods, it needs to rain longer on already moist soils," says lead author Dr Shijie Jiang, who now works at the Max Planck Institute for Biogeochemistry in Jena.

The scientists used explainable machine learning for the analysis. "First, we use the potential flood drivers air temperature, soil moisture, and snow depth as well as the weekly precipitation -- each day is considered as an individual driving factor -- to predict the run-off magnitude and thus the size of the flood," explains Zscheischler. The researchers then quantified which variables and combinations of variables contributed to the run-off of a particular flood and to which extent. This approach is referred to as explainable machine learning because it uncovers the predictive relationship between flood drivers and run-off during a flood in the trained model. "With this new methodology, we can quantify how many driving factors and combinations thereof are relevant for the occurrence and intensity of floods," adds Jiang.

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Researchers turn back the clock on cancer cells to offer new treatment paradigm

St. Jude Children's Research Hospital scientists reversed an aggressive cancer, reverting malignant cells towards a more normal state. Rhabdoid tumors are an aggressive cancer which is missing a key tumor suppressor protein. Findings showed that with the missing tumor suppressor, deleting or degrading the quality control protein DCAF5 reversed the cancer cell state. These results suggest a new approach to curing cancer -- returning cancerous cells to an earlier, more normal state rather than killing cancer cells with toxic therapies -- may be possible. The results were published today in Nature.

"Rather than making a toxic event that kills rhabdoid cancer, we were able to reverse the cancer state by returning the cells toward normal," said senior author Charles W.M. Roberts, MD, PhD, Executive Vice President and St. Jude Comprehensive Cancer Center director. "This approach would be ideal, especially if this paradigm could also be applied to other cancers."

"We found a dependency which actually reverses the cancer state," said first author Sandi Radko-Juettner, PhD, a former St. Jude Graduate School of Biomedical Sciences student, now a Research Program Manager for the Hematological Malignancies Program at St. Jude. "Standard cancer therapies work by causing toxicities that also damage healthy cells in the body. Here, it appears that we're instead fixing the problem caused by the loss of a tumor suppressor in this rhabdoid cancer."

Drugging the un-targetable

In many cancers, there is no easily druggable target. Often, these cancers are caused by a missing tumor suppressor protein, so there is nothing to target directly as the protein is missing. Loss of tumor suppressors is much more common than a protein gaining the ability to drive cancer. Consequently, finding a way to intervene therapeutically in these tumors is a high priority. The researchers were looking for a way to treat an aggressive set of cancers caused by the loss of the tumor suppressor protein SMARCB1 when they found a new approach to treatment.

The St. Jude group found a little-studied protein, DCAF5, was essential to rhabdoid tumors missing SMARCB1. Initially, they identified DCAF5 as a target, using the Dependency Map (DepMap) portal, a database of cancer cell lines and the genes critical for their growth. DCAF5 was a top dependency in rhabdoid tumors. After the initial finding, the scientists genetically deleted or chemically degraded DCAF5. The cancer cells reverted to a non-cancerous state, persisting even in a long-term mouse model.

"We saw a spectacular response," Roberts said. "The tumors melted away."

Removing quality control to reverse cancer

Normally, SMARCB1 is an essential component of a larger chromatin-regulating complex of proteins called the SWI/SNF complex. Unexpectedly, the study found that in the absence of SMARCB1, DCAF5 recognizes SWI/SNF as abnormal and destroys the complex. When DCAF5 degrades them, the researchers showed that SWI/SNF re-forms and maintains its ability to open chromatin and regulate gene expression. While the SWI/SNF activity level in the absence of SMARCB1 was to a lesser extent than usual, it was nonetheless sufficient to reverse the cancer state fully.

"DCAF5 is doing a quality control check to ensure that these chromatin machines are built well," Roberts said. "Think of a factory assembling a machine. You need quality checks to examine and find faults and to pull it off the line if it doesn't meet standards. DCAF5 is doing such quality assessments for the assembly of SWI/SNF complexes, telling the cell to get rid of complexes if SMARCB1 is absent."

"The mutation of SMARCB1 shuts off gene programs that prevent cancer. By targeting DCAF5, we're turning those gene programs back on," Radko-Juettner said. "We're reversing the cancer state because the cell is becoming more 'normal' when these complexes aren't targeted for destruction by DCAF5."

Future therapeutic opportunities to reverse cancer

"From a therapeutic perspective, our results are fascinating," Radko-Juettner said. "DCAF5 is part of a larger family of DCAF proteins that have been shown to be drug targetable. We showed that when DCAF5 is absent, mice had no discernable health effects, so we could potentially target DCAF5. This can kill the cancer cells but shouldn't affect healthy cells. Targeting DCAF5 thus has the potential to avoid the off-target toxicity of radiation or chemotherapy, making it a promising therapeutic avenue to pursue."

Beyond DCAF5, the findings could have implications for other cancers driven by the loss of a tumor suppressor.

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Scientists extract genetic secrets from 4,000-year-old teeth to illuminate the impact of changing human diets over the centuries

Researchers at Trinity College Dublin have recovered remarkably preserved microbiomes from two teeth dating back 4,000 years, found in an Irish limestone cave. Genetic analyses of these microbiomes reveal major changes in the oral microenvironment from the Bronze Age to today. The teeth both belonged to the same male individual and also provided a snapshot of his oral health.

The study, carried out in collaboration with archaeologists from the Atlantic Technological University and University of Edinburgh, was published today in journal Molecular Biology and Evolution. The authors identified several bacteria linked to gum disease and provided the first high-quality ancient genome of Streptococcus mutans, the major culprit behind tooth decay.

While S. mutans is very common in modern mouths, it is exceptionally rare in the ancient genomic record. One reason for this may be the acid-producing nature of the species. This acid decays the tooth, but also destroys DNA and stops plaque from fossilising. While most ancient oral microbiomes are retrieved from fossilised plaque, this study targeted the tooth directly.

Another reason for the scarcity of S. mutans in ancient mouths may be the lack of favorable habitats for this sugar-loving species. An uptick of dental cavities is seen in the archaeological record after the adoption of cereal agriculture thousands of years ago, but a far more dramatic increase has occurred only in the past few hundred years when sugary foods were introduced to the masses.

The sampled teeth were part of a larger skeletal assemblage excavated from Killuragh Cave, County Limerick, by the late Peter Woodman of University College Cork. While other teeth in the cave showed advanced dental decay, no cavities were visible on the sampled teeth. However, one tooth produced an unprecedented amount of S. mutans DNA, a sign of an extreme imbalance in the oral microbial community.

"We were very surprised to see such a large abundance of S. mutans in this 4,000-year-old tooth," said Dr Lara Cassidy, an assistant professor in Trinity's School of Genetics and Microbiology, and senior author of the study. "It is a remarkably rare find and suggests this man was at a high risk of developing cavities right before his death."

The researchers also found that other streptococcal species were virtually absent from the tooth. This indicates the natural balance of the oral biofilm had been upset -- mutans had outcompeted the other streptococci leading to the pre-disease state.

The team also found evidence to support the "disappearing microbiome" hypothesis, which proposes modern microbiomes are less diverse than those of our ancestors. This is cause for concern, as biodiversity loss can impact human health. The two Bronze Age teeth produced highly divergent strains of Tannerella forsythia, a bacteria implicated in gum disease.

"These strains from a single ancient mouth were more genetically different from one another than any pair of modern strains in our dataset, despite the modern samples deriving from Europe, Japan and the USA," explained Iseult Jackson, a PhD candidate at Trinity, and first author of the study. "This represents a major loss in diversity and one that we need to understand better."

Very few full genomes from oral bacteria have been recovered prior to the Medieval era. By characterising prehistoric diversity, the authors were able to reveal dramatic changes in the oral microenvironment that have happened since.

Dr Cassidy added: "Over the last 750 years, a single lineage of T. forsythia has become dominant worldwide. This is the tell-tale sign of natural selection, where one strain rises rapidly in frequency due to some genetic advantage it holds over the others. T. forsythia strains from the industrial era onwards contain many new genes that help the bacteria colonise the mouth and cause disease.

"S. mutans has also undergone recent lineage expansions and changes in gene content related to pathogenicity. These coincide with humanity's mass consumption of sugar, although we did find that modern S. mutans populations have remained more diverse, with deep splits in the S. mutans evolutionary tree pre-dating the Killuragh genome."

The scientists believe this is driven by differences in the evolutionary mechanisms that shape genome diversity in these species.

"S. mutans is very adept at swapping genetic material between strains," said Dr Cassidy. "This means an advantageous innovation can be spread across S. mutans lineages like a new piece of tech. This ability to easily share innovations may explain why this species retains many diverse lineages without one becoming dominant and replacing all the others."

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Sleeping supermassive black holes awakened briefly by shredded stars

A new investigation into an obscure class of galaxies known as Compact Symmetric Objects, or CSOs, has revealed that these objects are not entirely what they seem. CSOs are active galaxies that host supermassive black holes at their cores. Out of these monstrous black holes spring two jets traveling in opposite directions at nearly the speed of light. But in comparison to other galaxies that boast fierce jets, these jets do not extend out to great distances -- they are much more compact. For many decades, astronomers suspected that CSOs were simply young and that their jets would eventually travel out to greater distances.

Now, reporting in three different papers in The Astrophysical Journal, a Caltech-led team of researchers has concluded that CSOs are not young but rather lead relatively short lives.

"These CSOs are not young," explains Anthony (Tony) Readhead, the Robinson Professor of Astronomy, Emeritus, who led the investigation. "You wouldn't call a 12-year-old dog young even though it has lived a shorter life than an adult human. These objects are a distinct species all of their own that live and die out in thousands of years rather than the millions of years that are common in galaxies with bigger jets."

In the new studies, the team reviewed literature and past observations of more than 3,000 CSO candidates, verifying 64 as real and identifying an additional 15 CSOs. All these objects had been previously observed by the National Radio Astronomy Observatory's Very Long Baseline Array (VLBA), funded by the National Science Foundation (NSF), and some had been observed by other high-resolution radio telescopes. "The VLBA observations are the most detailed in astronomy, providing images with details equivalent to measuring the width of a human hair at a distance of 100 miles," Readhead says.

The team's analysis concludes that CSOs expel jets for 5,000 years or less and then die out. "The CSO jets are very energetic jets but they seem to shut off," says Vikram Ravi, assistant professor of astronomy at Caltech and a co-author of one of the studies. "The jets stop flowing from the source."

As for what is fueling the short-lived jets, the scientists believe the cause is a tidal disruption event (TDE), which occurs when a single star wanders too close to a supermassive black hole and is devoured.

"We think that a single star gets ripped apart, and then all that energy is channeled into jets along the axis the black hole is spinning around," Readhead says. "The giant black hole starts out invisible to us, and then when it consumes a star, boom! The black hole has fuel, and we can see it."

Readhead first suspected that CSOs might be fueled by TDEs back in the 1990s, but he says the idea went largely unnoticed by the scientific community. "The hypothesis was all but forgotten because years went by before observational evidence began to mount for TDEs," he says. At the time of his original hypothesis, only three CSOs had been found.

Fast forward to 2020. Readhead, who had paused his studies of CSOs to delve into different problems in radio astronomy, decided it was time to revisit the topic. He gathered some of his colleagues together on Zoom, and they decided to comb through literature and weed out objects that had been misclassified as CSOs. Over the next two years, the team investigated more than 3,000 CSO candidates, narrowing the group down to only dozens that had the criteria to be real CSOs.

Ultimately, a picture began to emerge of CSOs as an entirely distinct family with jets that die out much sooner than their gigantic brethren, such as those of the extremely powerful Cygnus A, a galaxy that shoots out extremely powerful jets that glow brightly at radio wavelengths. These jets stretch to distances of about 230,000 light-years in each direction and last tens of millions of years. In contrast, the CSO jets extend to about 1,500 light-years at most and die out by about 5,000 years.

According to the astronomers, the CSO jets likely form when a supermassive black hole snacks on not just any star, but a substantial one.

"The TDEs we've previously seen only lasted for a few years," Ravi says. "We think that the remarkable TDEs powering CSOs last far longer because the disrupted stars are very large in size, very massive, or both."

By analyzing the varied collection of CSO radio images, the researchers say they can trace how the objects age over time, almost like looking at a photo album of a CSO's life to observe how its jets evolve. The younger CSOs have shorter jets that are closer to the black holes, while the older objects have jets that extend further out from their black hole. Though most of the jets die out, the scientists estimate that one in 100 will go onto to become long-lived like those of Cygnus A. In those rare cases, the galaxies are likely merging with other galaxies, a turbulent process that provides a large quantity of fuel.

If the discoveries of Readhead and his team are confirmed with additional observations, the CSOs will provide a whole new avenue for studying how massive stars at the centers of galaxies interact with supermassive black holes.

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New roadmap to prevent pandemics centers on protecting biodiversity

An international team of 25 scientists has proposed a roadmap for how to prevent the next pandemic by conserving natural areas and promoting biodiversity, thereby providing animals with enough food, safe havens and distance to limit contact and the transfer of pathogens to humans.

Pandemics begin when disease-harboring animals, such as bats, come in close proximity with people, livestock or other animals and pass on new pathogens.

Viruses such as SARS-CoV-2, SARS-CoV-1, Nipah, Hendra and possibly Ebola have all fatally spilled over from bats to humans, sometimes through an intermediate host.

"The world is focused on how can we detect and then contain a novel pathogen once it is circulating in humans, rather than how can we prevent that pathogen from entering the human population in the first place," said Raina Plowright, professor in the Department of Public and Ecosystem Health at Cornell University, and first author of the paper, "Ecological Countermeasures to Prevent Pathogen Spillover and Subsequent Pandemics," published in Nature Communications.

The pandemic-prevention strategy is based on insights from a pair of 2022 papers that serve as a case study applicable to all animals that potentially carry zoonotic diseases.

Those papers -- about how bats can spread fatal Hendra virus to horses and people -- explained that when bats lose their natural habitats and winter food sources, their large populations splinter and they migrate in small groups to agricultural and urban areas.

They also become stressed, partly due to inadequate food sources, and they shed more virus in their urine.

The virus falls to the ground where grazing horses become infected; horses in turn can then infect people.

But when natural habitats can provide adequate food, especially in fallow winter months, the bats return to these habitats, aggregate in large numbers, and stop shedding virus.

The roadmap uses this and other case studies to explain the mechanisms linking environmental change and spillover of pathogens from animals to humans, and identifies ecological interventions to disrupt these links and policy frameworks to implement them.

Ecological interventions begin by protecting the places where animals eat.

"We need to make sure there's always an abundant supply of food available at all times of year, especially when animals are in stressful life history stages like reproduction and migration," Plowright said.

Next, it's important to protect where animals may roost or aggregate, as tens of thousands of bats can roost in canopies and caves, so when these areas are disturbed, these populations can splinter, move and shed more virus.

Also, cave dwelling bats may not have other caves to move to, in which case they stay put, become more stressed and likely shed more virus.

Protecting lands that act as buffers between people and wildlife is also key.

"There are trillions of microbes in nature, but we rarely actually get sick, because there are many, many barriers between us and new pathogens," Plowright said.

Lastly, for communities who come in contact with animals, it's important to ensure people have the protection that they need to avoid pathogen exposure, Plowright said.

The study's authors emphasize the need for an international agency or panel that can assess and synthesize data on pandemic prevention, preparedness and response and collect metrics on intactness of landscapes, ecological integrity and biodiversity.

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Beethoven's genes reveal low predisposition for beat synchronization

Ludwig van Beethoven, one of the most celebrated musicians in human history, has a rather low genetic predisposition for beat synchronization, according to a Current Biologystudy co-authored by Vanderbilt University Medical Center (VUMC) and theMax Planck Institutes for Empirical Aesthetics in Frankfurt am Main, Germany, and for Psycholinguistics in Nijmegen, the Netherlands.

The question of to what extent are exceptional human achievements influenced by genetic factors dates back to the early days of human genetics but seems to be easier to address today as modern molecular methods make it possible to analyze DNA of individuals throughout history.

An international team of researchers analyzed Beethoven's DNA to investigate his genetic musical predisposition, an ability closely related to musicality, by using sequences from a 2023 study in which the composer's genetic material was extracted from strands of his hair.

"For Beethoven, we used his recently sequenced DNA to calculate a polygenic score as an indicator for his genetic predisposition for beat synchronization," said Tara Henechowicz, B.Mus.Hons, M.A., a current PhD Candidate at the University of Toronto, recent visiting graduate student with the Vanderbilt Human Genetics Program, and the paper's second author.

"Interestingly, Beethoven, one of the most celebrated musicians in history, had an unremarkable polygenic score for general musicality compared to population samples from the Karolinska Institute in Sweden and Vanderbilt's BioVU Repository," she said.

The authors noted that it would be wrong to conclude from Beethoven's low polygenic score that his musical abilities were unexceptional.

"Our aim was to use this as an example of the challenges of making genetic predictions for an individual who lived over 200 years ago," Henechowicz said.

"The mismatch between the DNA-based prediction and Beethoven's musical genius provides a valuable teaching moment, because it demonstrates that DNA tests cannot give us a definitive answer about whether a given child will end up being musically gifted."

Henechowicz said the study does not discount that DNA contributes to people's musical skills, noting that prior studies have found an average heritability, which is the proportion of individual differences explained by all genetic factors, of 42% for musicality.

"In the current era of 'big data' such as Vanderbilt's BioVU repository, we have had the opportunity to look in fine detail at large groups of people to uncover the genetic underpinnings of traits such as rhythm ability or being musically active. The current study and other recent work also suggest that environment plays a key role in musical ability and engagement as well," said co-author Reyna Gordon, PhD, associate professor of Otolaryngology at VUMC and graduate co-advisor to Henechowicz.

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Persian plateau unveiled as crucial hub for early human migration out of Africa

A new study combining genetic, palaeoecological, and archaeological evidence has unveiled the Persian Plateau as a pivotal geographic location serving as a hub for Homo sapiens during the early stages of their migration out of Africa.

This revelation sheds new light on the complex journey of human populations, challenging previous understandings of our species' expansion into Eurasia.

The study, published in Nature Communications, highlights a crucial period between approximately 70,000 to 45,000 years ago when human populations did not uniformly spread across Eurasia, leaving a gap in our understanding of their whereabouts during this time frame.

Key findings from the research include:

• The Persian plateau as a hub for early human settlement: Using a novel genetic approach combined with palaeoecological modelling, the study revealed the Persian Plateau as the region where from population waves that settled all of Eurasia originated.
• This region emerged as a suitable habitat capable of supporting a larger population compared with other areas in West Asia.
• Genetic resemblance in ancient and modern populations: The genetic component identified in populations from the Persian Plateau underlines its long-lasting differentiation in the area, compatible with the hub nature of the region, and is ancestral to the genetic components already known to have inhabited the Plateau.
• Such a genetic signature was detected thanks to a new approach that disentangles 40,000 years of admixture and other confounding events. This genetic connection underscores the Plateau's significance as a pivotal location for early human settlement and subsequent migrations.

Study co-author Professor Michael Petraglia, Director of Griffith University's Australian Research Centre for Human Evolution, provided a much clearer picture of these early human movements.

"Our multidisciplinary study provides a more coherent view of the ancient past, offering insights into the critical period between the Out of Africa expansion and the differentiation of Eurasian populations," Professor Petraglia said.

"The Persian Plateau emerges as a key region, underlining the need for further archaeological explorations."

First author Leonardo Vallini of the University of Padova, Italy, said: "The discovery elucidates a 20,000 year long portion of the history of Homo sapiens outside of Africa, a timeframe during which we interacted with Neanderthal populations, and sheds light on the relationships between various Eurasian populations, providing crucial clues for understanding the demographic history of our species across Europe, East Asia, and Oceania."

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Tiniest 'starquake' ever detected

An orange dwarf star has yielded the tiniest 'starquakes' ever recorded, measured by an international team of scientists.

Named Epsilon Indi, the star is the smallest and coolest dwarf star yet observed with solar-like oscillations -- "starquakes" like those shown by the Sun.

These oscillations provide indirect glimpses of stellar interiors -- just as earthquakes tell us about Earth's interior -- and so are important sources of information about the makeup of the star.

The measurements were taken by an international team, led by the Institute of Astrophysics and Space Sciences in Portugal, and including researchers from the University of Birmingham.

The study is published in Astronomy and Astrophysics Letters.

The quakes were detected using a technique dubbed asteroseismology, which measures oscillations in stars.

Using the ESPRESSO spectrograph, mounted at the European Southern Observatory's (ESO) Very Large Telescope (VLT), the team was able to record the oscillations with unprecedented precision.

Lead author Tiago Campante, of the Institute of Astrophysics and Space Sciences at the University of Porto, said: "The extreme precision level of these observations is an outstanding technological achievement. Importantly, this detection conclusively shows that precise asteroseismology is possible down to cool dwarfs with surface temperatures as low as 4200 degrees Celsius, about 1000 degrees cooler than the Sun's surface, effectively opening up a new domain in observational astrophysics."

Orange dwarf stars have recently become a focus in the search for habitable planets and extraterrestrial life.

Professor Bill Chaplin, Head of the School of Physics & Astronomy at Birmingham, and a member of the team, said: "The mismatch between the predicted and observed sizes of these stars has implications for finding planets around them. If we use the most successful planet-finding technique -- the so-called transit method -- we get the size of the planet relative to the size of the star; if we don't size-up the star correctly, the same will be true of any small planet we have found." The detection of oscillations will help to understand and minimise these discrepancies, and improve the theoretical models of stars.

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Climate change will see Australia's soil emit CO2 and add to global warming

New Curtin University research has shown the warming climate will turn Australia's soil into a net emitter of carbon dioxide (CO2), unless action is taken.

Soil helps to keep the planet cool by absorbing carbon, however as the climate gets warmer its ability to retain carbon decreases -- and in some instances can start to release some carbon back into the air.

A global research team -- led by Professor Raphael Viscarra Rossel from Curtin's School of Molecular and Life Sciences -- predicted the changes in the amount of carbon in Australia's soil between now and the year 2100.

To do so, the team ran simulations using three different paths for society: an eco-focused 'sustainable' scenario, a 'middle-of-the-road' scenario and another which predicted a continued reliance on 'fossil-fuelled development'.

It found Australian soil will be a net emitter and could account for 8.3 per cent of Australia's total current emissions under the 'sustainable' scenario and more than 14 per cent by 2045 under the 'middle-of-the-road' and 'fossil-fuelled' scenarios.

By 2100, soil emissions under both scenarios are predicted to account for an even higher proportion of total emissions, but the predictions are more uncertain.

While some areas with arable farmland could continue to store carbon, the study found it would not be enough to offset the amounts of carbon lost from the soil in areas which are more sensitive to warmer weather, such as coastal regions and Australia's vast rangelands.

Australian soil holds an estimated 28 gigatons of carbon, 70 per cent of which is stored in these rangelands.

"Unless farming methods are further improved so farmland soils can continue to store carbon, any gains and benefit will likely decrease by 2045 and worsen in time, if the Earth continues to warm at its current rate," Professor Viscarra Rossel said.

"This means Australia's soil could release even more carbon into the air instead of storing it, which will in turn make climate change worse.

"If emissions continue at the current rate, the Earth's temperature is expected to reach 2 degrees above pre-industrial temperatures sometime this century, which is predicted to have dire consequences and

potentially catastrophic impacts for the planet."

Professor Viscarra Rossel said more sustainable pathways and improved management and conservation of soils were essential for Australia to meet its emissions reduction goals.

"Ensuring Australia's rangeland soils can maintain their carbon stocks is imperative: capturing and storing additional carbon will require interdisciplinary science, innovation, cultural awareness and effective policies" Professor Viscarra Rossel said.

"It will be challenging, given the rangelands' drier and more variable climate, its relatively sparse vegetation and other factors such as bushfires -- however, only a slight change over such large areas will make a positive difference.

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Stem cell model offers first glimpse of early human embryonic development

It's one of life's most defining moments -- that crucial step in embryonic development, when an indistinct ball of cells rearranges itself into the orderly three-layered structure that sets the stage for all to come. Known as gastrulation, this crucial process unfolds in the third week of human development. "Gastrulation is the origin of our own individualization, the emergence of our axis," says Rockefeller's Ali Brivanlou. "It is the first moment that separates our heads from our behinds."

Observing the molecular underpinnings of this pivotal event would go a long way toward helping scientists prevent miscarriages and developmental disorders. But studying human gastrulation has proven both technologically difficult and ethically complicated, and thus current approaches have had limited success in expanding our understanding of early human development. Now Brivanlou and colleagues have demonstrated how a stem cell model system known as a blastoid can allow the study of the nuances of human gastrulation in the presence of pre-implantation extra-embryonic cell types. Their study, published in Stem Cell Reports, describes the scientific and clinical potential of this new platform.

"Gastrulation was a tremendous black box. We had never seen ourselves at that stage," Brivanlou says. "This moves us closer to understanding how we begin."

A better blastocyst

Prior to implantation, an embryo is a ball of about 250 cells organized as a blastocyst. This elusive ball of cells was difficult to study directly, so scientists developed blastoids -- stem-cell-based blastocyst models. Blastoids can be cloned, experimentally manipulated, and programmed, allowing scientists to study identical blastoids over and over again.

The question was whether blastoids could gastrulate in vitro. Unlike a blastocyst in vivo, which rolls around in the uterus until it attaches to maternal tissue, blastoids were good at modeling the ball of cells from which life emerges, but it remained unclear whether this in vitro model could model later stages of human development. That is, until Brivanlou developed a platform to allow blastoids to attach in vitro, and thereby progress toward gastrulation.

"We were then able to see epiblast symmetry breaking, marked by BRA expression, for the first time with the high molecular resolution," says Riccardo De Santis, a research associate in the Brivanlou lab and lead author on the study. "This allowed us to start asking more detailed questions about the earliest moments of life."

With this unprecedented clarity, the team directly observed two key moments in gastrulation: the first epiblast symmetry-breaking event and the emergence of the molecular markers of the primitive streak and mesoderm upon in vitro attachment.

The primitive streak is a structure that marks the beginning of gastrulation and lays the foundation for the three primary layers of the embryo. One of those layers, the mesoderm, forms during gastrulation and gives rise to muscles, bones, and the circulatory system. The team discovered that, as early as seven days after attachment, they were already able to use molecular markers to detect the earliest signature of a nascent primitive streak and mesodermal cells.

To confirm their findings, the team also compared the blastoid results with data from in vitro attached human embryos and demonstrated that blastoids express the same genes in vitro that a regular embryo would at that stage in vivo, a strong demonstration of the power of blastoids as models for human embryonic development. Further highlighting the power of the lab's in vitro attached blastoid system, the team then used it to demonstrate that pathways that regulate the rise of the primitive streak and mesoderm in vivo also regulate blastoids symmetry breaking in vitro -- all with nothing but stem-cell-derived blastoid models.

Along the way, the team also demonstrated that gastrulation in vitro can begin at day 12, earlier than once thought. "This will change textbooks," Brivanlou says. "We've contributed to redefining the molecular signature and timing of the onset of gastrulation upon in vitro attachment."

Therapeutic possibilities

The results demonstrate that blastoids, when combined with the Brivanlou lab's unique attachment platform, are now capable of conveying insights into early human development that have long been inaccessible. De Santis envisions a future in which blastoid-based research leads to advancements in diagnosing and treating developmental disorders, or offers insights into potential causes of early miscarriages during gastrulation.

"Many couples can't have babies because the embryo doesn't attach properly, and many miscarriages occur in the first few weeks of pregnancy," De Santis explains. "We now have a model system that can help us understand the molecular mechanism that defines whether a pregnancy will be successful or not." In the near future, De Santis hopes to combine this method with machine learning to help predict pregnancy outcomes and the trajectories of developmental disorders by observing how model blastoids built with particular genetic makeups fare in vitro.

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Common household chemicals pose new threat to brain health, study finds

A team of researchers from the Case Western Reserve University School of Medicine has provided fresh insight into the dangers some common household chemicals pose to brain health. They suggest that chemicals found in a wide range of items, from furniture to hair products, may be linked to neurological conditions like multiple sclerosis and autism spectrum disorders.

Neurological problems impact millions of people, but only a fraction of cases can be attributed to genetics alone, indicating that unknown environmental factors are important contributors.

The new study published today in the journal Nature Neuroscience, discovered that some common home chemicals specifically affect the brain's oligodendrocytes, a specialized cell type that generates the protective insulation around nerve cells.

"Loss of oligodendrocytes underlies multiple sclerosis and other neurological diseases," said the study's principal investigator, Paul Tesar, the Dr. Donald and Ruth Weber Goodman Professor of Innovative Therapeutics and director of the Institute for Glial Sciences at the School of Medicine. "We now show that specific chemicals in consumer products can directly harm oligodendrocytes, representing a previously unrecognized risk factor for neurological disease."

On the premise that not enough thorough research has been done on the impact of chemicals on brain health, the researchers analyzed over 1,800 chemicals that may be exposed to humans. They identified chemicals that selectively damaged oligodendrocytes belong to two classes: organophosphate flame retardants and quaternary ammonium compounds. Since quaternary ammonium compounds are present in many personal-care products and disinfectants, which are being used more frequently since the COVID-19 pandemic began, humans are regularly exposed to these chemicals. And many electronics and furniture include organophosphate flame retardants.

The researchers used cellular and organoid systems in the laboratory to show that quaternary ammonium compounds cause oligodendrocytes to die, while organophosphate flame retardants prevented the maturation of oligodendrocytes.

They demonstrated how the same chemicals damage oligodendrocytes in the developing brains of mice. The researchers also linked exposure to one of the chemicals to poor neurological outcomes in children nationally.

"We found that oligodendrocytes -- but not other brain cells -- are surprisingly vulnerable to quaternary ammonium compounds and organophosphate flame retardants," said Erin Cohn, lead author and graduate student in the School of Medicine's Medical Scientist Training Program. "Understanding human exposure to these chemicals may help explain a missing link in how some neurological diseases arise."

The association between human exposure to these chemicals and effects on brain health requires further investigation, the experts warned. Future research must track the chemical levels in the brains of adults and children to determine the amount and length of exposure needed to cause or worsen disease.

"Our findings suggest that more comprehensive scrutiny of the impacts of these common household chemicals on brain health is necessary," Tesar said. "We hope our work will contribute to informed decisions regarding regulatory measures or behavioral interventions to minimize chemical exposure and protect human health."

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Quantum tornado provides gateway to understanding black holes

Scientists have for the first time created a giant quantum vortex to mimic a black hole in superfluid helium that has allowed them to see in greater detail how analogue black holes behave and interact with their surroundings.

Research led by the University of Nottingham, in collaboration with King's College London and Newcastle University, have created a novel experimental platform: a quantum tornado.

They have created a giant swirling vortex within superfluid helium that is chilled to the lowest possible temperatures.

Through the observation of minute wave dynamics on the superfluid's surface, the research team has shown that these quantum tornados mimic gravitational conditions near rotating black holes.

The research has been published today in Nature.

Lead author of the paper, Dr Patrik Svancara from the School of Mathematical Sciences at the University of Nottingham explains: "Using superfluid helium has allowed us to study tiny surface waves in greater detail and accuracy than with our previous experiments in water. As the viscosity of superfluid helium is extremely small, we were able to meticulously investigate their interaction with the superfluid tornado and compare the findings with our own theoretical projections."

The team constructed a bespoke cryogenic system capable of containing several litres of superfluid helium at temperatures lower than -271 °C. At this temperature liquid helium acquires unusual quantum properties.

These properties typically hinder the formation of giant vortices in other quantum fluids like ultracold atomic gases or quantum fluids of light, this system demonstrates how the interface of superfluid helium acts as a stabilizing force for these objects.

Dr Svancara continues: "Superfluid helium contains tiny objects called quantum vortices, which tend to spread apart from each other. In our set-up, we've managed to confine tens of thousands of these quanta in a compact object resembling a small tornado, achieving a vortex flow with record-breaking strength in the realm of quantum fluids."

Researchers uncovered intriguing parallels between the vortex flow and the gravitational influence of black holes on the surrounding spacetime.

This achievement opens new avenues for simulations of finite-temperature quantum field theories within the complex realm of curved spacetimes.

Professor Silke Weinfurtner, leading the work in the Black Hole Laboratory where this experiment was developed, highlights the significance of this work: "When we first observed clear signatures of black hole physics in our initial analogue experiment back in 2017, it was a breakthrough moment for understanding some of the bizarre phenomena that are often challenging, if not impossible, to study otherwise. Now, with our more sophisticated experiment, we have taken this research to the next level, which could eventually lead us to predict how quantum fields behave in curved spacetimes around astrophysical black holes."

This groundbreaking research is funded by a £5 million grant from the Science Technology Facilities Council, distributed among teams at seven leading UK institutions, including the University of Nottingham, Newcastle University and King's College London.

The project has also been supported by both the UKRI Network grant on Quantum Simulators for Fundamental Physics and the Leverhulme Research Leaders Fellowship held by Professor Silke Weinfurtner.

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Enormous ice loss from Greenland glacier

Ground-based measuring devices and aircraft radar operated in the far northeast of Greenland show how much ice the 79° N-Glacier is losing. According to measurements conducted by the Alfred Wegener Institute, the thickness of the glacier has decreased by more than 160 metres since 1998. Warm ocean water flowing under the glacier tongue is melting the ice from below. High air temperatures cause lakes to form on the surface, whose water flows through huge channels in the ice into the ocean. One channel reached a height of 500 metres, while the ice above was only 190 metres thick, as a research team has now reported in the scientific journal The Cryosphere.

A rustic camp in northeast Greenland was one of the bases for deploying autonomous measuring devices with modern radar technology by helicopter in a part of the 79° N-Glacier that is difficult to access.

Measurement flights with the polar aircraft of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and satellite data were also incorporated into a scientific study that has now been published in the scientific journal The Cryosphere. This study examines how global warming affects the stability of a floating ice tongue.

This is of great importance for the remaining ice shelves in Greenland as well as those in Antarctica, as instability of the ice shelf usually results in an acceleration of the ice flow, which would lead to a greater sea level rise.

"Since 2016, we have been using autonomous instruments to carry out radar measurements on the 79° N-Glacier, from which we can determine melt and thinning rates," says AWI glaciologist Dr Ole Zeising, the first author of the publication.

"In addition, we used aircraft radar data from 1998, 2018 and 2021 showing changes in ice thickness. We were able to measure that the 79° N-Glacier has changed significantly in recent decades under the influence of global warming."

The study shows how the combination of a warm ocean inflow and a warming atmosphere affects the floating ice tongue of the 79° N-Glacier in northeast Greenland.

Only recently, an AWI oceanography team published a modelling study on this subject.

The unique data set of observations now presented shows that extremely high melt rates occur over a large area near the transition to the ice sheet.

In addition, large channels form on the underside of the ice from the land side, probably because the water from huge lakes drains through the glacier ice.

Both processes have led to a strong thinning of the glacier in recent decades.

Due to extreme melt rates, the ice of the floating glacier tongue has become 32 % thinner since 1998, especially from the grounding line where the ice comes into contact with the ocean.

In addition, a 500-metre-high channel has formed on the underside of the ice, which spreads towards the inland.

The researchers attribute these changes to warm ocean currents in the cavity below the floating tongue and to the runoff of surface meltwater as a result of atmospheric warming.

A surprising finding was that melt rates have decreased since 2018.

A possible cause for this is a colder ocean inflow. "The fact that this system reacts on such short time scales is astonishing for systems that are actually inert such as glaciers," says Prof Dr Angelika Humbert, who is also involved in the study.

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If faces look like demons, you could have this extraordinary condition

Imagine if every time you saw a face, it appeared distorted. Well, for those who have a very rare condition known as prosopometamorphopsia (PMO), which causes facial features to appear distorted, that is reality.

As the Dartmouth-based website about prosopometamorphopsia explains, "'Prosopo' comes from the Greek word for face 'prosopon' while 'metamorphopsia' refers to perceptual distortions.''' Specific symptoms vary from case to case and can affect the shape, size, color, and position of facial features. The duration of PMO also varies; it "can last for days, weeks, or even years."

A new Dartmouth study published in the "Clinical Pictures" section of The Lancet reports on a unique case of a patient with PMO.

The research is the first to provide accurate and photorealistic visualizations of the facial distortions experienced by an individual with PMO.

The patient, a 58-year-old male with PMO, sees faces without any distortions when they are viewed on a screen and on paper, but he sees distorted faces that appear "demonic" when viewed in-person.

Most PMO cases however, see distortions in all contexts, so his case is especially rare and presented a unique opportunity to accurately depict his distortions.

For the study, the researchers took a photograph of a person's face.

Then, they showed the patient the photograph on a computer screen while he looked at the real face of the same person.

The researchers obtained real-time feedback from the patient on how the face on the screen and the real face in front of him differed, as they modified the photograph using computer software to match the distortions perceived by the patient.

"In other studies of the condition, patients with PMO are unable to assess how accurately a visualization of their distortions represents what they see because the visualization itself also depicts a face, so the patients will perceive distortions on it too," says lead author Antônio Mello, a PhD student in the Department of Psychological and Brain Sciences at Dartmouth.

In contrast, this patient doesn't see distortions on a screen.

This means that the researchers were able to modify the face in the photograph, and the patient could accurately compare how similar his perception of the real face was to the manipulated photograph.

"Through the process, we were able to visualize the patient's real-time perception of the face distortions," says Mello.

In their research with other PMO cases, the co-authors state that some of their PMO participants have seen health professionals who wanted to help but diagnosed them with another health condition, not PMO.

"We've heard from multiple people with PMO that they have been diagnosed by psychiatrists as having schizophrenia and put on anti-psychotics, when their condition is a problem with the visual system," says senior author Brad Duchaine, a professor of psychological and brain sciences and principal investigator of the Social Perception Lab at Dartmouth.

"And it's not uncommon for people who have PMO to not tell others about their problem with face perception because they fear others will think the distortions are a sign of a psychiatric disorder," says Duchaine.

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