Jun 22, 2023

Exoplanet may reveal secrets about the edge of habitability

How close can a rocky planet be to a star, and still sustain water and life? A recently discovered exoplanet may be key to solving that mystery.

"Super-Earth" LP 890-9c (also named SPECULOOS-2c) is providing important insights about conditions at the inner edge of a star's habitable zone and why Earth and Venus developed so differently, according to new research led by Lisa Kaltenegger, associate professor of astronomy at Cornell University.

Her team found LP 890-9c, which orbits close to the inner edge of its solar system's habitable zone, would look vastly different depending on whether it still had warm oceans, a steam atmosphere, or if it had lost its water -- assuming it once had oceans like Earth's.

"Looking at this planet will tell us what's happening on this inner edge of the habitable zone -- how long a rocky planet can maintain habitability when it starts to get hot," Kaltenegger said. "It will teach us something fundamental about how rocky planets evolve with increasing starlight, and about what will one day happen to us and Earth."

Kaltenegger is the lead author of "Hot Earth or Young Venus? A Nearby Transiting Rocky Planet Mystery," published in Monthly Notices of the Royal Astronomical Society: Letters.

LP 890-9c is one of two super-Earths orbiting a red dwarf star located 100 light years from Earth, researchers announced last year. They said liquid water or an atmosphere rich in water vapor was possible on LP 890-9c, which is about 40% larger than Earth and circles the small, cool star in 8.5 days.

Those criteria suggested it to be one of the best targets for JWST to study among the known, potentially habitable terrestrial planets, in addition to the TRAPPIST-1 system.

The team's models are the first to detail differences in the chemical signatures generated by rocky planets near the habitable zone's interior boundary, based on variables including the planet's size, mass, chemical makeup, surface temperature and pressure, atmospheric height and cloud cover. The calculations were key to estimating how much time JWST would need to confirm the basic composition of an atmosphere -- if there is one.

The models span several scenarios thought to reflect stages of rocky planets' evolution, ranging from a "hot Earth" where life might still be possible, to a desolate Venus featuring a carbon dioxide atmosphere. In between are phases Earth is expected to experience as the sun grows brighter and hotter with age, causing the oceans to gradually evaporate and fill the atmosphere with steam before boiling off entirely.

How long those processes might take is unknown, and the astronomers say LP 890-9c provides a rare opportunity to explore that evolution.

"This planet is the first target where we can test these different scenarios," Kaltenegger said. "If it's still a hotter Earth -- hot, but with liquid water and conditions for life -- then the timeline is slower than we thought. If we see that it's already a full-blown Venus, then the water gets lost fast."

It's possible that LP 890-9c has no atmosphere and hosts no life, or that it resembles a Venus with thick clouds that would block light from reflecting and thus yield little information. Deeper investigation promises to provide valuable clues, Kaltenegger said.

Read more at Science Daily

Focus on function helps identify the changes that made us human

Humans split away from our closest animal relatives, chimpanzees, and formed our own branch on the evolutionary tree about seven million years ago. In the time since -- brief, from an evolutionary perspective -- our ancestors evolved the traits that make us human, including a much bigger brain than chimpanzees and bodies that are better suited to walking on two feet. These physical differences are underpinned by subtle changes at the level of our DNA. However, it can be hard to tell which of the many small genetic differences between us and chimps have been significant to our evolution.

New research from Whitehead Institute Member Jonathan Weissman; University of California, San Francisco Assistant Professor Alex Pollen; Weissman lab postdoc Richard She; Pollen lab graduate student Tyler Fair; and colleagues uses cutting edge tools developed in the Weissman lab to narrow in on the key differences in how humans and chimps rely on certain genes. Their findings, published in the journal Cell on June 20th, may provide unique clues into how humans and chimps have evolved, including how humans became able to grow comparatively large brains.

Studying function rather than genetic code

Only a handful of genes are fundamentally different between humans and chimps; the rest of the two species' genes are typically nearly identical. Differences between the species often come down to when and how cells use those nearly identical genes. However, only some of the many differences in gene use between the two species underlie big changes in physical traits. The researchers developed an approach to narrow in on these impactful differences.

Their approach, using stem cells derived from human and chimp skin samples, relies on a tool called CRISPR interference (CRISPRi) that Weissman's lab developed. CRISPRi uses a modified version of the CRISPR/Cas9 gene editing system to effectively turn off individual genes. The researchers used CRISPRi to turn off each gene one at a time in a group of human stem cells and a group of chimp stem cells. Then they looked to see whether or not the cells multiplied at their normal rate. If the cells stopped multiplying as quickly or stopped altogether, then the gene that had been turned off was considered essential: a gene that the cells need to be active-producing a protein product-in order to thrive. The researchers looked for instances in which a gene was essential in one species but not the other as a way of exploring if and how there were fundamental differences in the basic ways that human and chimp cells function.

By looking for differences in how cells function with particular genes disabled, rather than looking at differences in the DNA sequence or expression of genes, the approach ignores differences that do not appear to impact cells. If a difference in gene use between species has a large, measurable effect at the level of the cell, this likely reflects a meaningful difference between the species at a larger physical scale, and so the genes identified in this way are likely to be relevant to the distinguishing features that have emerged over human and chimp evolution.

"The problem with looking at expression changes or changes in DNA sequences is that there are many of them and their functional importance is unclear," says Weissman, who is also a professor of biology at the Massachusetts Institute of Technology and an Investigator with the Howard Hughes Medical Institute. "This approach looks at changes in how genes interact to perform key biological processes, and what we see by doing that is that, even on the short timescale of human evolution, there has been fundamental rewiring of cells."

After the CRISPRi experiments were completed, She compiled a list of the genes that appeared to be essential in one species but not the other. Then he looked for patterns. Many of the 75 genes identified by the experiments clustered together in the same pathways, meaning the clusters were involved in the same biological processes. This is what the researchers hoped to see. Individual small changes in gene use may not have much of an effect, but when those changes accumulate in the same biological pathway or process, collectively they can cause a substantive change in the species. When the researchers' approach identified genes that cluster in the same processes, this suggested to them that their approach had worked and that the genes were likely involved in human and chimp evolution.

"Isolating the genetic changes that made us human has been compared to searching for needles in a haystack because there are millions of genetic differences, and most are likely to have negligible effects on traits," Pollen says. "However, we know that there are lots of small effect mutations that in aggregate may account for many species differences. This new approach allows us to study these aggregate effects, enabling us to weigh the impact of the haystack on cellular functions."

Researchers think bigger brains may rely on genes regulating how quickly cells divide

One cluster on the list stood out to the researchers: a group of genes essential to chimps, but not to humans, that help to control the cell cycle, which regulates when and how cells decide to divide. Cell cycle regulation has long been hypothesized to play a role in the evolution of humans' large brains. The hypothesis goes like this: Neural progenitors are the cells that will become neurons and other brain cells. Before becoming mature brain cells, neural progenitors divide multiple times to make more of themselves. The more divisions that the neural progenitors undergo, the more cells the brain will ultimately contain -- and so, the bigger it will be. Researchers think that something changed during human evolution to allow neural progenitors to spend less time in a non-dividing phase of the cell cycle and transition more quickly towards division. This simple difference would lead to additional divisions, each of which could essentially double the final number of brain cells.

Consistent with the popular hypothesis that human neural progenitors may undergo more divisions, resulting in a larger brain, the researchers found that several genes that help cells to transition more quickly through the cell cycle are essential in chimp neural progenitor cells but not in human cells. When chimp neural progenitor cells lose these genes, they linger in a non-dividing phase, but when human cells lose them, they keep cycling and dividing. These findings suggest that human neural progenitors may be better able to withstand stresses -- such as the loss of cell cycle genes -- that would limit the number of divisions the cells undergo, enabling humans to produce enough cells to build a larger brain.

"This hypothesis has been around for a long time, and I think our study is among the first to show that there is in fact a species difference in how the cell cycle is regulated in neural progenitors," She says. "We had no idea going in which genes our approach would highlight, and it was really exciting when we saw that one of our strongest findings matched and expanded on this existing hypothesis."

More subjects lead to more robust results

Research comparing chimps to humans often uses samples from only one or two individuals from each species, but this study used samples from six humans and six chimps. By making sure that the patterns they observed were consistent across multiple individuals of each species, the researchers could avoid mistaking the naturally occurring genetic variation between individuals as representative of the whole species. This allowed them to be confident that the differences they identified were truly differences between species.

The researchers also compared their findings for chimps and humans to orangutans, which split from the other species earlier in our shared evolutionary history. This allowed them to figure out where on the evolutionary tree a change in gene use most likely occurred. If a gene is essential in both chimps and orangutans, then it was likely essential in the shared ancestor of all three species; it's more likely for a particular difference to have evolved once, in a common ancestor, than to have evolved independently multiple times. If the same gene is no longer essential in humans, then its role most likely shifted after humans split from chimps. Using this system, the researchers showed that the changes in cell cycle regulation occurred during human evolution, consistent with the proposal that they contributed to the expansion of the brain in humans.

Read more at Science Daily

AI reveals hidden traits about our planet's flora to help save species

In a world-first, scientists from UNSW and Botanic Gardens of Sydney, have trained AI to unlock data from millions of plant specimens kept in herbaria around the world, to study and combat the impacts of climate change on flora.

"Herbarium collections are amazing time capsules of plant specimens," says lead author on the study, Associate Professor Will Cornwell. "Each year over 8000 specimens are added to the National Herbarium of New South Wales alone, so it's not possible to go through things manually anymore."

Using a new machine learning algorithm to process over 3000 leaf samples, the team discovered that contrary to frequently observed interspecies patterns, leaf size doesn't increase in warmer climates within a single species.

Published in the American Journal of Botany, this research not only reveals that factors other than climate have a strong effect on leaf size within a plant species, but demonstrates how AI can be used to transform static specimen collections and to quickly and effectively document climate change effects.

Herbarium collections move to the digital world

Herbaria are scientific libraries of plant specimens that have existed since at least the 16th century.

"Historically, a valuable scientific effort was to go out, collect plants, and then keep them in a herbarium. Every record has a time and a place and a collector and a putative species ID," says A/Prof. Cornwell, a researcher at the School of BEES and a member of UNSW Data Science Hub.

A couple of years ago, to help facilitate scientific collaboration, there was a movement to transfer these collections online.

"The herbarium collections were locked in small boxes in particular places, but the world is very digital now. So to get the information about all of the incredible specimens to the scientists who are now scattered across the world, there was an effort to scan the specimens to produce high resolution digital copies of them."

The largest herbarium imaging project was undertaken at the Botanic Gardens of Sydney when over 1 million plant specimens at the National Herbarium of New South Wales were transformed into high-resolution digital images.

"The digitisation project took over two years and shortly after completion, one of the researchers -- Dr Jason Bragg -- contacted me from the Botanic Gardens of Sydney. He wanted to see how we could incorporate machine learning with some of these high-resolution digital images of the Herbarium specimens."

"I was excited to work with A/Prof. Cornwell in developing models to detect leaves in the plant images, and to then use those big datasets to study relationships between leaf size and climate," says Dr Bragg.

"Computer vision" measures leaf sizes

Together with Dr Bragg at the Botanic Gardens of Sydney and UNSW Honours student Brendan Wilde, A/Prof. Cornwell created an algorithm that could be automated to detect and measure the size of leaves of scanned herbarium samples for two plant genera -- Syzygium (generally known as lillipillies, brush cherries or satinas) and Ficus (a genus of about 850 species of woody trees, shrubs and vines).

"This is a type of AI is called a convolutional neural network, also known as Computer Vision," says A/Prof. Cornwell. The process essentially teaches the AI to see and identify the components of a plant in the same way a human would.

"We had to build a training data set to teach the computer, this is a leaf, this is a stem, this is a flower," says A/Prof. Cornwell. "So we basically taught the computer to locate the leaves and then measure the size of them.

"Measuring the size of leaves is not novel, because lots of people have done this. But the speed with which these specimens can be processed and their individual characteristics can be logged is a new development."

A break in frequently observed patterns

A general rule of thumb in the botanical world is that in wetter climates, like tropical rainforests, the leaves of plants are bigger compared to drier climates, such as deserts.

"And that's a very consistent pattern that we see in leaves between species all across the globe," says A/Prof. Cornwell. "The first test we did was to see if we could reconstruct that relationship from the machine learned data, which we could. But the second question was, because we now have so much more data than we had before, do we see the same thing within species?"

The machine learning algorithm was developed, validated, and applied to analyse the relationship between leaf size and climate within and among species for Syzygium and Ficus plants.

The results from this test were surprising -- the team discovered that while this pattern can be seen between different plant species, the same correlation isn't seen within a single species across the globe, likely because a different process, known as gene flow, is operating within species. That process weakens plant adaptation on a local scale and could be preventing the leaf size-climate relationship from developing within species.

Using AI to predict future climate change responses

The machine learning approach used here to detect and measure leaves, though not pixel perfect, provided levels of accuracy suitable for examining links between leaf traits and climate.

"But because the world is changing quite fast, and there is so much data, these kinds of machine learning methods can be used to effectively document climate change effects," says A/Prof. Cornwell.

Read more at Science Daily

New research reveals the impact of different species and their traits on human wellbeing

New research has revealed for the first time that well-functioning ecosystems are crucial to human health and wellbeing, with human-biodiversity interactions delivering wellbeing gains equating to substantial healthcare cost-savings, when scaled-up across populations.

The University of Kent-led study, which is part of the European Research Council-funded project 'Relating Subjective Wellbeing to Biodiversity' (RELATE), set out to understand which components of nature and biodiversity played a particular role in human wellbeing.

The team, which was led by Kent's Professor Zoe Davies, analysed the effects of species' traits, based on people's feedback following a series of workshops, to identify those that generate different types of wellbeing e.g., physical, emotional, cognitive, social, spiritual, and 'global', the latter being akin to 'whole-person health'.

The team found that, in general, the vast majority of species and traits are beneficial to human wellbeing. They also discovered that each species may support multiple traits, potentially with different impacts. For example, the colours of brambles (black, pink, red) are linked to multiple positive physical, emotional and social wellbeing types, but their prickly texture generated negative emotional wellbeing. The numerous traits from across an ecological community can elicit a multitude of wellbeing responses, illustrating the true complexity of how people relate to biodiversity.

Professor Davies, a biodiversity conservationist at Kent's Durrell Institute of Conservation and Ecology (DICE), said: 'While we know that spending time in natural environments can improve our health and wellbeing, we still need to know more about which species, or traits of species (such as colours, sounds, smells, textures and behaviours), deliver these benefits -- and how people's relationships with biodiversity are both contextually and culturally specific. Understanding how people experience biodiversity is therefore key to successfully managing biodiversity to facilitate human wellbeing.'

Study co-author, Professor Martin Dallimer, from the School of Earth and Environment, University of Leeds, said: 'For the first time, through analysing people's own words and reflections, we are able to explicitly link that feeling of wellbeing with species and their traits. How people respond to biodiversity is hugely varied and if we want people's wellbeing to benefit from spending time in nature, then it is essential to make sure we are maintaining and restoring high quality biodiverse spaces for wildlife and for people. Our aim is that these findings really drive home how important biodiversity is in underpinning wellbeing benefits, particularly to healthcare and public sectors who include 'spending time in nature' as an element of mental health and wellbeing.'

Read more at Science Daily

Jun 21, 2023

Navigating underground with cosmic-ray muons

Superfast, subatomic-sized particles called muons have been used to wirelessly navigate underground in a reportedly world first. By using muon-detecting ground stations synchronized with an underground muon-detecting receiver, researchers at the University of Tokyo were able to calculate the receiver's position in the basement of a six-story building. As GPS cannot penetrate rock or water, this new technology could be used in future search and rescue efforts, to monitor undersea volcanoes, and guide autonomous vehicles underground and underwater.

GPS, the global positioning system, is a well-established navigation tool and offers an extensive list of positive applications, from safer air travel to real-time location mapping. However, it has some limitations. GPS signals are weaker at higher latitudes and can be jammed or spoofed (where a counterfeit signal replaces an authentic one). Signals can also be reflected off surfaces like walls, interfered with by trees, and can't pass through buildings, rock or water.

By comparison, muons have been making headlines in recent years for their abilityto help us look deep inside volcanoes, peek through pyramids and see inside cyclones. Muons fall constantly and frequently around the world (about 10,000 per square meter per minute) and can't be tampered with. "Cosmic-ray muons fall equally across the Earth and always travel at the same speed regardless of what matter they traverse, penetrating even kilometers of rock," explained Professor Hiroyuki Tanaka from Muographix at the University of Tokyo. "Now, by using muons, we have developed a new kind of GPS, which we have called the muometric positioning system (muPS), which works underground, indoors and underwater."

MuPS was initially created to help detect seafloor changes caused by underwater volcanoes or tectonic movement. It uses four muon-detecting reference stations aboveground to provide coordinates for a muon-detecting receiver underground. Early iterations of this technology required the receiver to be connected to a ground station by a wire, greatly restricting movement. However, this latest research uses high-precision quartz clocks to synchronize the ground stations with the receiver. The four parameters provided by the reference stations plus the synchronized clocks used to measure the muons' "time-of-flight" enables the receiver's coordinates to be determined. This new system is called the muometric wireless navigation system (MuWNS).

To test the navigation ability of MuWNS, reference detectors were placed on the sixth floor of a building while a "navigatee" took a receiver detector to the basement floor. They slowly walked up and down the corridors of the basement while holding the receiver. Rather than navigating in real time, measurements were taken and used to calculate their route and confirm the path they had taken.

"The current accuracy of MuWNS is between 2 meters and 25 meters, with a range of up to 100 meters, depending on the depth and speed of the person walking. This is as good as, if not better than, single-point GPS positioning aboveground in urban areas," said Tanaka. "But it is still far from a practical level. People need one-meter accuracy, and the key to this is the time synchronization."

Improving this system to enable real-time, meter-accurate navigation hinges on time and money. Ideally the team wants to use chip-scale atomic clocks (CSAC): "CSACs are already commercially available and are two orders of magnitude better than the quartz clocks we currently use. However, they are too expensive for us to use now. But, I foresee that they will become much cheaper as the global demand for CSAC for cellphones increases," said Tanaka.

Read more at Science Daily

Scientists unearth 20 million years of 'hot spot' magmatism under Cocos plate

Ten years ago, Samer Naif made an unexpected discovery in Earth's mantle: a narrow pocket, proposed to be filled with magma, hidden some 60 kilometers beneath the seafloor of the Cocos Plate.

Mantle melts are buoyant and typically float toward the surface -- think underwater volcanoes that erupt to form strings of islands. But Naif's imaging instead showed a clear slice of semi-molten rock: low-degree partial melts, still sandwiched at the base of the plate some 37 miles beneath the ocean floor.

Then, the observation provided an explanation for how tectonic plates can gradually slide, lubricated by partial melting. The study also "raised several questions about why magma is stored in a thin channel -- and where the magma originated from," says Naif, an assistant professor in the School of Earth and Atmospheric Sciences at Georgia Institute of Technology.

Fellow researchers went on to share competing interpretations for the cause of the channel -- including studies that argued against magma being needed to explain the observation.

So Naif went straight to the source.

"I basically went on a multiyear hunt, akin to a Sherlock Holmes detective story, looking for clues of mantle magmas that we first observed in the 2013 Nature study," he says. "This involved piecing together evidence from several independent sources, including geophysical, geochemical, and geological (direct seafloor sampling) data."

Now, the results of that search are detailed in a new Science Advances article, "Episodic intraplate magmatism fed by a long-lived melt channel of distal plume origin," authored by Naif and researchers from the U.S. Geological Survey at Woods Hole Coastal and Marine Science Center, Northern Arizona University, Lamont-Doherty Earth Observatory of Columbia University, the Department of Geology and Geophysics at Woods Hole Oceanographic Institution, and GNS Science of Lower Hutt, New Zealand.

Zeroing in

A relatively young oceanic plate -- some 23 million years old -- the Cocos Plate traces down the western coast of Central America, veering west to the Pacific Plate, then north to meet the North American Plate off the Pacific coast of Mexico.

Sliding between these two plates caused the devastating 1985 Mexico City earthquake and the 2017 Chiapas earthquake, while similar subduction between the Cocos and Caribbean plates resulted in the 1992 Nicaragua tsunami and earthquake, and the 2001 El Salvador earthquakes.

Scientists study the edges of these oceanic plates to understand the history and formation of volcanic chains -- and to help researchers and agencies better prepare for future earthquakes and volcanic activity.

It's in this active area that Naif and fellow researchers recently set out to document a series of magmatic intrusions just beneath the seafloor, in the same area that the team first detected the channel of magma back in 2013.

Plumbing the depths

For the new study, the team combined geophysical, geochemical, and seafloor drilling results with seismic reflection data, a technique used to image layers of sediments and rocks below the surface. "It helps us to see the geology where we cannot see it with our own eyes," Naif explains.

First, the researchers observed an abundance of widespread intraplate magmatism. "Volcanism where it is not expected," Naif says, "basically away from plate boundaries: subduction zones and mid-ocean ridges."

Think Hawaii, where "a mantle plume of hot, rising material melts during its ascent, and then forms the Hawaii volcanic chain in the middle of the Pacific Ocean," just as with the Cocos Plate, where the team imaged the volcanism fed by magma at the lithosphere-asthenosphere boundary -- the base of the sliding tectonic plates.

"Below it is the convecting mantle," Naif adds. "The tectonic plates are moving around on Earth's surface because they are sliding on the asthenosphere below them."

The researchers also found that this channel below the lithosphere is regionally extensive -- over 100,000 square kilometers -- and is a "long-lived feature that originated from the Galápagos Plume," a mantle plume that formed the volcanic Galápagos islands, supplying melt for a series of volcanic events across the past 20 million years, and persisting today.

Importantly, the new study also suggests that these plume-fed melt channels may be widespread and long-lived sources for intraplate magmatism itself -- as well as for mantle metasomatism, which happens when Earth's mantle reacts with fluids to form a suite of minerals from the original rocks.

Connecting the (hot spot) dots

"This confirms that magma was there in the past -- and some of it leaked through the mantle and erupted near the seafloor," Naif says, "in the form of sill intrusions and seamounts: basically volcanoes located on the seafloor."

The work also provides compelling supporting evidence that magma could still be stored in the channel. "More surprising is that the erupted magma has a chemical fingerprint that links its source to the Galápagos mantle plume."

"We learned that the magma channel has been around for at least 20 million years, and on occasion some of that magma leaks to the seafloor where it erupts volcanically," Naif adds.

The team's identified source of the magma, the Galápagos Plume, "is more than 1,000 kilometers away from where we detected this volcanism. It is not clear how magma can stay around in the mantle for such a long time, only to leak out episodically."

Plume hunters wanted

The evidence that the team compiled is "really quite subtle and requires a detailed and careful study of a suite of seafloor observations to connect the dots," Naif says. "Basically, the signs of such volcanism, while they are quite clear here, also require high resolution data and several different types of data to be able to detect such subtle seafloor features."

So, "if we can see such subtle clues of volcanism here," Naif explains, "it means a similar, careful analysis of high resolution data in other parts of the seafloor may lead to similar discoveries of volcanism elsewhere, caused by other mantle plumes."

"There are numerous mantle plumes dotted across the planet. There are also numerous seamounts -- at least 100,000 of them! -- covering the seafloor, and it is anyone's guess how many of them formed in the middle of the tectonic plates because of magma sourced from distant mantle plumes that leaked to the surface."

Read more at Science Daily

Face of Anglo-Saxon teen VIP revealed with new evidence about her life

The face of a 16-year-old woman buried near Cambridge (UK) in the 7th century with an incredibly rare gold and garnet cross (the 'Trumpington Cross') has been reconstructed following analysis of her skull. The striking image is going on public display for the first time on 21st June,* with new scientific evidence showing that she moved to England from Central Europe as a young girl, leading to an intriguing change in her diet.

Forensic artist Hew Morrison created the likeness using measurements of the woman's skull and tissue depth data for Caucasian females. Without DNA analysis, Morrison could not be sure of her precise eye and hair colour, but the image offers a strong indication of her appearance shortly before she died.

Hew Morrison said: "It was interesting to see her face developing. Her left eye was slightly lower, about half a centimetre, than her right eye. This would have been quite noticeable in life."

New "you are what you eat" isotopic analysis of the young woman's bones and teeth conducted by bioarchaeologists Dr Sam Leggett and Dr Alice Rose, and archaeologist Dr Emma Brownlee, during PhD research at the University of Cambridge also reveals that she moved to England from somewhere near the Alps, perhaps southern Germany, sometime after she turned 7 years old.

Leggett and Rose also found that once the girl had arrived in England, the proportion of protein in her diet decreased by a small but significant amount. This change occurred close to the end of her young life, showing that the period between her migration and burial near Cambridge was tragically short.

Dr Leggett, now at the University of Edinburgh, said: "She was quite a young girl when she moved, likely from part of southern Germany, close to the Alps, to a very flat part of England. She was probably quite unwell and she travelled a long way to somewhere completely unfamiliar -- even the food was different. It must have been scary."

Previous analysis indicated that the young woman had suffered from illness but her cause of death remains unknown. She was buried in a remarkable way -- lying on a carved wooden bed wearing the cross, gold pins (also on display) and fine clothing.

Hers is one of only 18 bed burials ever uncovered in the UK. Her ornate cross, combining gold and garnets (third quarter of the 7th century), is one of only five of its kind ever found in Britain and identifies her as one of England's earliest converts to Christianity and as a member of the aristocracy if not royalty. The best known example of such a cross was found in the coffin of St Cuthbert.

In 597 AD, the pope dispatched St Augustine to England on a mission to convert the pagan Anglo-Saxon kings, a process which continued for many decades.

Dr Leggett said: "She must have known that she was important and she had to carry that on her shoulders. Her isotopic results match those of two other women who were similarly buried on beds in this period in Cambridgeshire.

"So it seems that she was part of an elite group of women who probably travelled from mainland Europe, most likely Germany, in the 7th century, but they remain a bit of a mystery. Were they political brides or perhaps brides of Christ? The fact that her diet changed once she arrived in England suggests that her lifestyle may have changed quite significantly."

Dr Sam Lucy, a specialist in Anglo-Saxon burial from Newnham College, Cambridge, who published the Anglo-Saxon excavations at Trumpington**, said:

"These are intriguing findings, and it is wonderful to see this collaborative research adding to our knowledge of this period. Combining the new isotopic results with Emma Brownlee's research into European bed burials really does seem to suggest the movement of a small group of young elite women from a mountainous area in continental Europe to the Cambridge region in the third quarter of the seventh century.

"Southern Germany is a distinct possibility owing to the bed burial tradition known there. Given the increasingly certain association between bed burial, such cross-shaped jewellery, and early Anglo-Saxon Christianity, it is possible that their movement related to pan-European networks of elite women who were heavily involved in the early Church."

Dr Jody Joy, the exhibition's co-curator, said: "The story of this young woman goes to the very heart of what our exhibition is all about -- new research making visible the lives of people at pivotal moments of Cambridgeshire's history. MAA holds one of Britain's most important collections of Early Medieval archaeology and the Trumpington bed burial is so important. It looks like it still has much more to teach us."

In the exhibition, the 'Trumpington Cross' will be displayed together with the delicate gold and garnet pins connected by a gold chain, which were found near the teenager's neck. These pins probably secured a long veil to an outer garment of fine linen. The pins would have caught the light as she moved.The burial bed's decorativeheadboard will also be exhibited.

* The image and artefacts from the mysterious woman's burial -- discovered in 2012 by the Cambridge Archaeological Unit at Trumpington Meadows on Cambridge's southern limits -- including her famous cross will be unveiled in a major new exhibition at Cambridge's Museum of Archaeology and Anthropology (MAA). 'Beneath Our Feet: Archaeology of the Cambridge Region' will run from 21st June to 14th April 2024.

Read more at Science Daily

Regular napping linked to larger brain volume

Daytime napping may help to preserve brain health by slowing the rate at which our brains shrink as we age, suggests a new study led by researchers at UCL and the University of the Republic in Uruguay.

The study, published in the journal Sleep Health, analysed data from people aged 40 to 69 and found a causal link between habitual napping and larger total brain volume -- a marker of good brain health linked to a lower risk of dementia and other diseases.

Senior author Dr Victoria Garfield (MRC Unit for Lifelong Health & Ageing at UCL) said: "Our findings suggest that, for some people, short daytime naps may be a part of the puzzle that could help preserve the health of the brain as we get older."

Previous research has shown that napping has cognitive benefits, with people who have had a short nap performing better in cognitive tests in the hours afterwards than counterparts who did not nap.

The new study aimed to establish if there was a causal relationship between daytime napping and brain health.

Using a technique called Mendelian randomisation, they looked at 97 snippets of DNA thought to determine people's likelihood of habitual napping. They compared measures of brain health and cognition of people who are more genetically "programmed" to nap with counterparts who did not have these genetic variants, using data from 378,932 people from the UK Biobank study, and found that, overall, people predetermined to nap had a larger total brain volume.

The research team estimated that the average difference in brain volume between people programmed to be habitual nappers and those who were not was equivalent to 2.6 to 6.5 years of ageing.

But the researchers did not find a difference in how well those programmed to be habitual nappers performed on three other measures of brain health and cognitive function -- hippocampal volume, reaction time and visual processing.

Lead author and PhD candidate Valentina Paz (University of the Republic (Uruguay) and MRC Unit for Lifelong Health & Ageing at UCL) said: "This is the first study to attempt to untangle the causal relationship between habitual daytime napping and cognitive and structural brain outcomes. By looking at genes set at birth, Mendelian randomisation avoids confounding factors occurring throughout life that may influence associations between napping and health outcomes. Our study points to a causal link between habitual napping and larger total brain volume."

Dr Garfield added: "I hope studies such as this one showing the health benefits of short naps can help to reduce any stigma that still exists around daytime napping."

The genetic variants influencing our likelihood to nap were identified in an earlier study looking at data from 452,633 UK Biobank participants. The study, led by Dr Hassan Dashti (Harvard University and Massachusetts General Hospital), also an author on the new study, identified the variants on the basis of self-reported napping, and this was supported by objective measurements of physical activity recorded by a wrist-worn accelerometer.

In the new study, researchers analysed health and cognition outcomes for people with these genetic variants as well as several different subsets of these variants, adjusted to avoid potential bias, for instance avoiding variants linked to excessive daytime sleepiness.

Genetic data and magnetic resonance imaging (MRI) scans of the brain were available for 35,080 individuals drawn from the larger UK Biobank sample.

In terms of study limitations, the authors noted that all of the participants were of white European ancestry, so the findings might not be immediately generalisable to other ethnicities.

While the researchers did not have information on nap duration, earlier studies suggest that naps of 30 minutes or less provide the best short-term cognitive benefits, and napping earlier in the day is less likely to disrupt night-time sleep.

Previous research looking at the UK and the Netherlands found that nearly a third of adults aged 65 or over had a regular nap.

Read more at Science Daily

Jun 20, 2023

Scientists report 'benchmarks' for extreme space weather

High-energy 'relativistic' electrons -- so-called "killer" electrons -- are a major source of radiation damage to satellites and so understanding their patterns of activity is crucial. Bursts of charged particles and magnetic fields from the Sun can tear open the Earth's magnetic field, giving rise to geomagnetic storms. During these events the number of killer electrons in the outer radiation belt can increase by orders of magnitude and become a significant space weather hazard.

Dr Nigel Meredith of BAS led an international team who analysed 20 years of data from a US GPS satellite to determine the 1 in 10, 1 in 50, and 1 in 100-year event levels. A 1 in 100-year event is an event of a size that will be equalled or exceeded on average once every 100 years.

Satellite operators, manufacturers, insurers, and governments need to prepare and mitigate against the risks posed by these electrons. Society is increasingly reliant on satellites for a variety of applications including communication, navigation, Earth observation and defence. As of April 2022, there were 5,465 operational satellites in Earth orbit, and most are exposed to energetic electrons for at least some of their orbit. In 2021, the overall global space economy generated revenues of $386 billion, an increase of four percent compared to the previous year.

Dr Nigel Meredith, space weather scientist and lead author of the study says:

"The 1 in 100 year event levels reported in this study are important for industry and government. They serve as benchmarks against which to compare other extreme space weather events and to assess the potential impact of an extreme event."

These findings are vitally important to the satellite industry as engineers and operators require realistic estimates of the largest electron fluxes encountered in GPS orbit to prepare for the impacts of these extreme events and to improve the resilience of future satellites. The findings are essential for satellite insurers to help them ensure satellite operators are doing all they can to reduce risk and to evaluate realistic disaster scenarios

The difference between the 1 in 10 year and 1 in 100-year event varies depending on the energy of the electrons and the distance from Earth. These differences are largest at the highest energies furthest from the planet, varying between a factor of 3 and 10 for some of the highest electron energies over 35,000 km from the Earth's surface. Such substantial increases could pose a significant additional risk to satellites operating in this region.

Like weather on our planet, space weather can vary greatly over minutes, days, seasons and the 11-year solar cycle. The researchers found that the majority of these killer electron events occurred during the solar cycle's declining phases -- seen twice during the 20-year period they studied -- but the largest event was elsewhere, showing that extreme events can happen at any time.

Read more at Science Daily

New method traces ancestry of hybrid plants and animals

If you've ever kept a garden, you're probably familiar with hybrids, from disease-resistant tomatoes to Stargazer lilies.

Hybrids -- common in agriculture as well as in nature -- have chromosomes from two or more parent species. In some cases, including strawberries, goldfish and several other species, these disparate parental chromosomes become doubled, a condition known as allopolyploidy.

In "Transposon signatures of allopolyploid subgenome evolution," a recent article published in the journal Nature Communications, Binghamton University Assistant Professor of Biological Sciences Adam Session and Daniel S. Rokhsar, a professor of genetics, evolution and development at the University of California, Berkeley, outline a way to trace these genomes back to the polypoid hybrid's parent species.

Unlike previous methods, which use comparison with related non-hybrid species to decipher polypoid ancestry, the authors' method allows them to discover distinct ancestries by looking at genomic patterns in the hybrid itself.

"Each ancestral genome carries a unique set of repetitive elements," Session explained. "So if we find sets of chromosomes in a polypoid that carry different repetitive elements, that proves hybrid ancestry and allows us to figure out which chromosomes were inherited together coming from the various progenitor species."

In the article, they apply the method to some well-studied cases of polyploid hybrids, such as tobacco, cotton and cyprinid fish, such as goldish and carp. They also use it to tease out the disputed ancestries of other hybrids, including false flax and strawberries.

"In many cases, the ancestors of living polyploids are not known. Using our method, we can figure out the ancestral origin of different chromosomes just by studying the polyploid genome itself, and divide the chromosomes into sets, or 'sub-genomes,' derived from its various ancestors," he said. "In addition to identifying the subgenomes, we can also tell you the order in which they were put together."

Polyploidization -- the duplication of genomes in a hybrid that stabilizes its ancestry -- is much more common in plants than animals, since plants can better tolerate multiple copies of their genomes, Session explained. The process of polyploidization is more involved with animal species, although it does happen in some fish and amphibians. In the case of goldfish, the authors prove for the first time that they share the same duplicated gene sequences as common carp, and thus a common hybrid ancestor.

Polyploidy is unknown in mammals, although hybridization is still possible. Take mules, for instance, which are a hybrid between horses and donkeys: Male mules are effectively sterile, although female mules can mate with either parent species. But without genomic duplication, the distinctive hybrid type cannot be stably propagated.

A tetraploid such as cotton has four copies of each chromosome, two from each of two ancestors, while hexaploids -- such as false flax -- have six chromosomes derived from three parent species. With eight copies of each chromosome, an octoploid such as strawberry ultimately has four ancestral species.

Polyploids have complex biology that is still being deciphered, and figuring out the sub-genome structure of their genomes is a step forward. Over millions of years, the genes contributed by each of the parental species evolve in their new polyploid context. Some redundant genes are lost or inactivated; others can develop new functions or novel interactions with their counterparts in the other sub-genomes. The new work argues that the order in which parental species are added to the emerging polyploid mix in a higher polyploid like strawberry can have profound impact on how these evolutionary processes occur. Sorting out the impact of these duplicated on the evolving polyploid is an ongoing challenge, the authors said.

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Scientists investigate the evolution of animal developmental mechanisms, show how some of Earth's earliest animals evolved

Lacking bones, brains, and even a complete gut, the body plans of simple animals like sea anemones appear to have little in common with humans and their vertebrate kin. Nevertheless, new research from Investigator Matt Gibson, Ph.D., at the Stowers Institute for Medical Research shows that appearances can be deceiving, and that a common genetic toolkit can be deployed in different ways to drive embryological development to produce very different adult body plans.

It is well established that sea anemones, corals, and their jellyfish relatives shared a common ancestor with humans that plied the Earth's ancient oceans over 600 million years ago. A new study from the Gibson Lab, published in Current Biology on June 13, 2023, illuminates the genetic basis for body plan development in the starlet sea anemone, Nematostella vectensis. This new knowledge paints a vivid picture of how some of the earliest animals on earth progressed from egg to embryo to adult.

"Studying the developmental genetics of Nematostella is sort of like taking a time machine into the very distant past," said Gibson. "Our work allows us to ask what life looked like long ago -- hundreds of millions of years before the dinosaurs. How did ancient animals develop from egg to adult, and to what extent have the genetic mechanisms that guide embryonic development endured across millennia?"

Most contemporary animals, from insects to vertebrates, develop by forming a head-to-tail series of segments that assume distinct identities depending on their position. Within a given segment, there is a further axis of polarity that informs cells whether they are at the front or back of the segment. Collectively, this is referred to as segment polarization.

Shuonan He, Ph.D., a former predoctoral researcher from the Gibson Lab, uncovered genes involved during development of the sea anemone, Nematostella vectensis, that guide the formation of segments and others that direct segment polarity programs strikingly similar to organisms higher up the evolutionary tree of life, including humans.

"The significance is that the genetic instructions underlying the construction of extremely different animal body plans, for example, a sea anemone and a human, are incredibly similar," said Gibson. "The genetic logic is largely the same."

This new study builds upon a 2018 study published in Science from the Gibson Lab that showed that sea anemones have an internal bilateral symmetry early in development with eight radial segments. The study demonstrated that Hox genes -- master development genes that are crucial for human development -- act to delineate boundaries between segments and likely had an ancient role in segment construction.

The team's latest finding explores how segments form and what accounts for differences in their identities. Using spatial transcriptomics, or the differences in gene expression between segments, the team discovered hundreds of new segment-specific genes. These include two crucial genes that encode transcription factors that govern segment polarization under the control of Hox genes and are required for the proper placement of sea anemone muscles.

The astonishing diversity of organisms on Earth can be compared to the assembly of Legos. "Whether you construct a dinosaur, a sea anemone, or a human, many of the core genetic building blocks are largely the same despite drastically different animal forms," said Gibson.

This is the first time that scientists have evidence of a molecular basis for segment polarization in a pre-bilaterian animal. While extensively studied in bilateral species like fruit flies and humans, the idea that cnidarian animals possess segmentation was unexpected. Now, the team has evidence that these segments are also polarized.

"This provides further evidence that investigating a broad diversity of animals can have direct implications for understanding general principles, including those which apply to human biology," said Gibson. "Going one step further, by understanding the logic of sea anemone development and comparing it to what we see in vertebrates, we can also extrapolate back in time to understand how animals likely developed hundreds of millions of years ago."

Read more at Science Daily

Clean, sustainable fuels made 'from thin air' and plastic waste

Researchers have demonstrated how carbon dioxide can be captured from industrial processes -- or even directly from the air -- and transformed into clean, sustainable fuels using just the energy from the Sun.

The researchers, from the University of Cambridge, developed a solar-powered reactor that converts captured CO2 and plastic waste into sustainable fuels and other valuable chemical products. In tests, CO2 was converted into syngas, a key building block for sustainable liquid fuels, and plastic bottles were converted into glycolic acid, which is widely used in the cosmetics industry.

Unlike earlier tests of their solar fuels technology however, the team took CO2 from real-world sources -- such as industrial exhaust or the air itself. The researchers were able to capture and concentrate the CO2 and convert it into sustainable fuel.

Although improvements are needed before this technology can be used at an industrial scale, the results, reported in the journal Joule, represent another important step toward the production of clean fuels to power the economy, without the need for environmentally destructive oil and gas extraction.

For several years, Professor Erwin Reisner's research group, based in the Yusuf Hamied Department of Chemistry, has been developing sustainable, net-zero carbon fuels inspired by photosynthesis -- the process by which plants convert sunlight into food -- using artificial leaves. These artificial leaves convert CO2 and water into fuels using just the power of the sun.

To date, their solar-driven experiments have used pure, concentrated CO2 from a cylinder, but for the technology to be of practical use, it needs to be able to actively capture CO2 from industrial processes, or directly from the air. However, since CO2 is just one of many types of molecules in the air we breathe, making this technology selective enough to convert highly diluted CO2 is a huge technical challenge.

"We're not just interested in decarbonisation, but de-fossilisation -- we need to completely eliminate fossil fuels in order to create a truly circular economy," said Reisner. "In the medium term, this technology could help reduce carbon emissions by capturing them from industry and turning them into something useful, but ultimately, we need to cut fossil fuels out of the equation entirely and capture CO2 from the air."

The researchers took their inspiration from carbon capture and storage (CCS), where CO2 is captured and then pumped and stored underground.

"CCS is a technology that's popular with the fossil fuel industry as a way to reduce carbon emissions while continuing oil and gas exploration," said Reisner. "But if instead of carbon capture and storage, we had carbon capture and utilisation, we could make something useful from CO2 instead of burying it underground, with unknown long-term consequences, and eliminate the use of fossil fuels."

The researchers adapted their solar-driven technology so that it works with flue gas or directly from the air, converting CO2 and plastics into fuel and chemicals using only the power of the sun.

By bubbling air through the system containing an alkaline solution, the CO2 selectively gets trapped, and the other gases present in air, such as nitrogen and oxygen, harmlessly bubble out. This bubbling process allows the researchers to concentrate the CO2 from air in solution, making it easier to work with.

The integrated system contains a photocathode and an anode. The system has two compartments: on one side is captured CO2 solution that gets converted into syngas, a simple fuel. On the other plastics are converted into useful chemicals using only sunlight.

"The plastic component is an important trick to this system," said co-first author Dr Motiar Rahaman. "Capturing and using CO2 from the air makes the chemistry more difficult. But, if we add plastic waste to the system, the plastic donates electrons to the CO2. The plastic breaks down to glycolic acid, which is widely used in the cosmetics industry, and the CO2 is converted into syngas, which is a simple fuel."

"This solar-powered system takes two harmful waste products -- plastic and carbon emissions -- and converts them into something truly useful," said co-first author Dr Sayan Kar.

"Instead of storing CO2 underground, like in CCS, we can capture it from the air and make clean fuel from it," said Rahaman. "This way, we can cut out the fossil fuel industry from the process of fuel production, which can hopefully help us avoid climate destruction."

"The fact that we can effectively take CO2 from air and make something useful from it is special," said Kar. "It's satisfying to see that we can actually do it using only sunlight."

Read more at Science Daily

Jun 19, 2023

Researchers demystify the unusual origin of the Geminids meteor shower

The Geminids meteoroids light up the sky as they race past Earth each winter, producing one of the most intense meteor showers in our night sky.

Mysteries surrounding the origin of this meteoroid stream have long fascinated scientists because, while most meteor showers are created when a comet emits a tail of ice and dust, the Geminids stem from an asteroid -- a chunk of rock that normally does not produce a tail. Until recently, the Geminids had only been studied from Earth.

Now, Princeton researchers used observations from NASA's Parker Solar Probe mission to deduce that it was likely a violent, catastrophic event -- such as a high-speed collision with another body or a gaseous explosion -- that created the Geminids. The findings, which were published in the Planetary Science Journal on June 15, narrow down hypotheses about this asteroid's composition and history that would explain its unconventional behavior.

"Asteroids are like little time capsules for the formation of our solar system," said Jamey Szalay, research scholar at the Princeton University space physics laboratory and co-author on the paper. "They were formed when our solar system was formed, and understanding their composition gives us another piece of the story."

An unusual asteroid

Unlike most known meteor showers that come from comets, which are made of ice and dust, the Geminids stream seems to originate from an asteroid -- a chunk of rock and metal -- called 3200 Phaethon.

"Most meteoroid streams are formed via a cometary mechanism, it's unusual that this one seems to be from an asteroid," said Wolf Cukier, undergraduate class of 2024 at Princeton and lead author on the paper.

"Additionally, the stream is orbiting slightly outside of its parent body when it's closest to the sun, which isn't obvious to explain just by looking at it," he added, referring to a recent study with Parker Solar Probe images of the Geminids led by Karl Battams of the Naval Research Laboratory.

When a comet travels close to the Sun it gets hotter, causing the ice on the surface to release a tail of gas, which in turn drags with it little pieces of ice and dust. This material continues to trail behind the comet as it stays within the Sun's gravitational pull. Over time, this repeated process fills the orbit of the parent body with material to form a meteoroid stream.

But because asteroids like 3200 Phaethon are made of rock and metal, they are not typically affected by the Sun's heat the way comets are, leaving scientists to wonder what causes the formation of 3200 Phaethon's stream across the night sky.

"What's really weird is that we know that 3200 Phaethon is an asteroid, but as it flies by the Sun, it seems to have some kind of temperature-driven activity," Szalay said. "Most asteroids don't do that."

Some researchers have suggested that 3200 Phaethon may actually be a comet that lost all of its snow, leaving only a rocky core resembling an asteroid. But the new Parker Solar Probe data show that although some of 3200 Phaethon's activity is related to temperature, the creation of the Geminids stream was likely not caused by a cometary mechanism, but by something much more catastrophic.

Opening the time capsule

To learn about the origin of the Geminids stream, Cukier and Szalay used the new Parker Solar Probe data to model three possible formation scenarios, then compared these models to existing models created from Earth-based observations.

"There are what's called the 'basic' model of formation of a meteoroid stream, and the 'violent' creation model," Cukier said. "It's called 'basic' because it's the most straight-forward thing to model, but really these processes are both violent, just different degrees of violence."

These different models reflect the chain of events that would transpire according to the laws of physics based on different scenarios. For example, Cukier used the basic model to simulate all of the chunks of material releasing from the asteroid with zero relative velocity -- or with no speed or direction relative to 3200 Phaethon -- to see what the resulting orbit would look like and compare it to the orbit shown by the Parker Solar Probe probe data.

He then used the violent creation model to simulate the material releasing from the asteroid with a relative velocity of up to one kilometer per hour, as if the pieces were knocked loose by a sudden, violent event.

He also simulated the cometary model -- the mechanism behind the formation of most meteoroid streams. The resulting simulated orbit matched the least with the way the Geminids orbit actually appears according to the Parker Solar Probe data, so they ruled out this scenario.

In comparing the simulated orbits from each of the models, the team found that the violent models were most consistent with the Parker Solar Probe data, meaning it's likely that a sudden, violent event -- such as a high-speed collision with another body or a gaseous explosion, among other possibilities -- created the Geminids stream.

The research builds on the work of Szalay and several colleagues of the Parker Solar Probe mission, built and assembled at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, to assemble a picture of the structure and behavior of the large cloud of dust that swirls through the innermost solar system.

They took advantage of Parker's flight path -- an orbit that swings it just millions of miles from the Sun, closer than any spacecraft in history -- to get the best direct look at the dusty cloud of grains shed from passing comets and asteroids.

Although the probe doesn't measure dust particles directly, it can track dust grains in a clever way: as dust grains pelt the spacecraft along its path, the high-velocity impacts create plasma clouds. These impact clouds produce unique signals in electric potential that are picked up by several sensors on the probe's FIELDS instrument, which is designed to measure the electric and magnetic fields near the Sun.

"The first-of-its-kind data our spacecraft is gathering now will be analyzed for decades to come," said Nour Raouafi, Parker Solar Probe project scientist at APL. "And it's exciting to see scientists of all levels and skills digging into it to shed light on the Sun, the solar system and the universe beyond."

Reaching for the stars

Cukier said his passion for learning about outer space combined with departmental support are what motivated him to pursue this project.

After taking a hands-on lab class offered by the Princeton space physics laboratory -- where he gained practical experience building space instruments, like those currently sampling the Sun's environment aboard Parker Solar Probe -- and serving as treasurer for the undergraduate astronomy club, he decided he wanted to pursue extracurricular research.

He was met with enthusiasm when he reached out to scientists in the Princeton Space Physics group. "Everyone is very supportive of undergraduate research, especially in astrophysics, because it's really part of the departmental culture," he said.

"It's always wonderful when our students like Wolf can contribute so strongly to this sort of space research," said David McComas, head of the Space Physics group and vice president for the Princeton Plasma Physics Laboratory (PPPL). "Many of us have been in awe of the Geminids meteor displays for years and it is awesome to finally have the data and research to show how they likely formed."

Cukier said that he's been drawn to watching the sky since he was a kid. "Planetary science is surprisingly accessible," he said. "For the Geminids, for instance, anyone can go outside on December 14 this year at night and look up. It's visible from Princeton, and some of the meteors are really bright. I'd highly recommend seeing it."

Read more at Science Daily

New dinosaur discovered: Ankylosaurs may have been far more diverse than originally thought

A new armoured dinosaur, known as an ankylosaur, has been described and named for Prof Paul Barrett of the Natural History Museum.

Vectipelta barretti was discovered in the Wessex formation on the Isle of Wight and represents the first armoured dinosaur from the dinosaur Isle to be described in 142 years.

Lead author Stuart Pond explained the importance of this find, 'This is an important specimen because it sheds light on ankylosaur diversity within the Wessex formation and Early Cretaceous England.

'For virtually 142 years, all ankylosaur remains from the Isle of Wight have been assigned to Polacanthus foxii, a famous dinosaur from the island, now all of those finds need to be revisited because we've described this new species.'

The new species differs from Polacanthus foxii, previously the only known ankylosaur from the Isle of Wight, in several key characteristics. The fossilized remains show differences in the neck and back vertebrae, a very different structure to the pelvis and more blade-like spiked armour.

The researchers used phylogenetic analysis to work out the relationships between different ankylosaurs and discovered that they are not actually very closely related. In fact, Vectipelta was found to be most closely related to some Chinese ankylosaurs, suggesting dinosaurs moved freely from Asia to Europe in the Early Cretaceous.

Vectipelta barretti would have been roaming the earth during the Early Cretaceous, a time for which fossil remains are rare worldwide. This has led some to suggest that a mass extinction occurred at the end of the Jurassic, which makes the understanding of dinosaur diversity at this time crucial to understanding if such an event occurred and how life recovered. With rocks from this time mostly absent in North America, the Wessex Formation and the Isle of Wight are hugely important areas in answering these questions.

At the time the Isle of Wight would have had a climate similar to that of the Mediterranean and was a flood plain covered by a large meandering river system. Floods would have washed organic material such as plants, logs and even dinosaur bodies together and, as waters receded, this organic matter would have been isolated in ponds on the floodplain that eventually dried out and were buried in the clay soil, preserving this organic material as the fossils we find today.

On naming the new dinosaur for Prof Paul Barrett of the Natural History Museum, senior author Dr Susannah Maidment said, 'Myself and some of the other authors on this study have been mentored or supervised by Paul for most of our careers, and it was notable to us that Paul hadn't had a dinosaur named after him yet. He's hugely influential in in vertebrate palaeontology, and he's a world-leading authority on dinosaurs.

'We really wanted to thank him for his support and mentorship, so we decided to name a, slow-moving, spikey organism after him.'

Prof Paul Barrett has worked at the Natural History Museum, London for 20 years and in that time has published an impressive 220 scientific papers. He has also supervised 31 PhD students and mentored many others, encouraging a whole new generation of palaeontologists.

Of the honour Prof Barrett said, 'I'm flattered and absolutely delighted to have been recognised in this way, not least as the first paper I ever wrote was also on an armoured dinosaur in the NHM collections. I'm sure that any physical resemblance is purely accidental.'

The team are optimistic that more species will be discovered in the area in the future. Dr Maidment concluded, 'We have new iguanodontians that we are lining up, to be prepped and to be studied. I think we have at least two new taxa in the collections. With regards to ankylosaurs, they are somewhat rarer, so I think we need to keep our eyes peeled.'

Read more at Science Daily

Fossil study sheds light on famous spirals found in nature

Leaf arrangements in the earliest plants differ from most modern plants, overturning a long-held theory regarding the origins of a famous mathematical pattern found in nature, research shows.

The findings indicate that the arrangement of leaves into distinctive spirals, that are common in nature today, were not common in the most ancient land plants that first populated the earth's surface.

Instead, the ancient plants were found to have another type of spiral. This negates a long held theory about the evolution of plant leaf spirals, indicating that they evolved down two separate evolutionary paths.

Whether it is the vast swirl of a hurricane or the intricate spirals of the DNA double-helix, spirals are common in nature and most can be described by the famous mathematical series the Fibonacci sequence.

Named after the Italian mathematician, Leonardo Fibonacci, this sequence forms the basis of many of nature's most efficient and stunning patterns.

Spirals are common in plants, with Fibonacci spirals making up over 90% of the spirals. Sunflower heads, pinecones, pineapples and succulent houseplants all include these distinctive spirals in their flower petals, leaves or seeds.

Why Fibonacci spirals, also known as nature's secret code, are so common in plants has perplexed scientists for centuries, but their evolutionary origin has been largely overlooked.

Based on their widespread distribution it has long been assumed that Fibonacci spirals were an ancient feature that evolved in the earliest land plants and became highly conserved in plants.

However, an international team led by the University of Edinburgh has overthrown this theory with the discovery of non-Fibonacci spirals in a 407-million-year old plant fossil.

Using digital reconstruction techniques the researchers produced the first 3D models of leafy shoots in the fossil clubmoss Asteroxylon mackiei -- a member of the earliest group of leafy plants.

The exceptionally preserved fossil was found in the famous fossil site the Rhynie chert, a Scottish sedimentary deposit near the Aberdeenshire village of Rhynie.

The site contains evidence of some of the planet's earliest ecosystems -- when land plants first evolved and gradually started to cover the earth's rocky surface making it habitable.

The findings revealed that leaves and reproductive structures in Asteroxylon mackiei, were most commonly arranged in non-Fibonacci spirals that are rare in plants today.

This transforms scientists understanding of Fibonacci spirals in land plants. It indicates that non-Fibonacci spirals were common in ancient clubmosses and that the evolution of leaf spirals diverged into two separate paths.

The leaves of ancient clubmosses had an entirely distinct evolutionary history to the other major groups of plants today such as ferns, conifers and flowering plants.

The team created the 3D model of Asteroxylon mackiei, which has been extinct for over 400 million years, by working with digital artist Matt Humpage, using digital rendering and 3D printing.

The research, published in the journal Science, was funded by UK Research and Innovation (UKRI), The Royal Society and the German Research Foundation.

The study also involved researchers from, University College Cork, Ireland, University Münster, Germany and Northern Rogue Studios, UK.

Dr Sandy Hetherington, an evolutionary palaeobiologist and the project's lead at the University of Edinburgh, said:

"Our model of Asteroxylon mackiei lets us examine leaf arrangement in 3D for the first time. The technology to 3D print a 407-million-year old plant fossils and hold it in your hand is really incredible.

"Our findings give a new perspective on the evolution of Fibonacci spirals in plants."

Holly-Anne Turner, who worked on the project as an undergraduate student at the University of Edinburgh and is first author of the study, said:

"The clubmoss Asteroxylon mackiei is one of the earliest examples of a plant with leaves in the fossil record.

Read more at Science Daily

First hominin muscle reconstruction shows 3.2 million-year-old 'Lucy' could stand as erect as we can

A Cambridge University researcher has digitally reconstructed the missing soft tissue of an early human ancestor -- or hominin -- for the first time, revealing a capability to stand as erect as we do today.

Dr Ashleigh Wiseman has 3D-modelled the leg and pelvis muscles of the hominin Australopithecus afarensis using scans of 'Lucy': the famous fossil specimen discovered in Ethiopia in the mid-1970s.

Australopithecus afarensis was an early human species that lived in East Africa over three million years ago. Shorter than us, with an ape-like face and smaller brain, but able to walk on two legs, it adapted to both tree and savannah dwelling -- helping the species survive for almost a million years.

Named for the Beatles classic 'Lucy in the Sky with Diamonds', Lucy is one of the most complete examples to be unearthed of any type of Australopithecus -- with 40% of her skeleton recovered.

Wiseman was able to use recently published open source data on the Lucy fossil to create a digital model of the 3.2 million-year-old hominin's lower body muscle structure. The study is published in the journal Royal Society Open Science.

The research recreated 36 muscles in each leg, most of which were much larger in Lucy and occupied greater space in the legs compared to modern humans.

For example, major muscles in Lucy's calves and thighs were over twice the size of those in modern humans, as we have a much higher fat to muscle ratio. Muscles made up 74% of the total mass in Lucy's thigh, compared to just 50% in humans.

Paleoanthropologists agree that Lucy was bipedal, but disagree on how she walked. Some have argued that she moved in a crouching waddle, similar to chimpanzees -- our common ancestor -- when they walk on two legs. Others believe that her movement was closer to our own upright bipedalism.

Research in the last 20 years have seen a consensus begin to emerge for fully erect walking, and Wiseman's work adds further weight to this. Lucy's knee extensor muscles, and the leverage they would allow, confirm an ability to straighten the knee joints as much as a healthy person can today.

"Lucy's ability to walk upright can only be known by reconstructing the path and space that a muscle occupies within the body," said Wiseman, from Cambridge University's McDonald Institute for Archaeological Research.

"We are now the only animal that can stand upright with straight knees. Lucy's muscles suggest that she was as proficient at bipedalism as we are, while possibly also being at home in the trees. Lucy likely walked and moved in a way that we do not see in any living species today," Wiseman said.

"Australopithecus afarensis would have roamed areas of open wooded grassland as well as more dense forests in East Africa around 3 to 4 million years ago. These reconstructions of Lucy's muscles suggest that she would have been able to exploit both habitats effectively."

Lucy was a young adult, who stood at just over one metre tall and probably weighed around 28kg. Lucy's brain would have been roughly a third of the size of ours.

To recreate the muscles of this hominin, Wiseman started with some living humans. Using MRI and CT scans of the muscle and bone structures of a modern woman and man, she was able to map the "muscle paths" and build a digital musculoskeletal model.

Wiseman then used existing virtual models of Lucy's skeleton to "rearticulate" the joints -- that is, put the skeleton back together. This work defined the axis from which each joint was able to move and rotate, replicating how they moved during life.

Finally, muscles were layered on top, based on pathways from modern human muscle maps, as well as what little "muscle scarring" was discernible (the traces of muscle connection detectable on the fossilised bones). "Without open access science, this research would not have been possible," said Wiseman.

Read more at Science Daily

Jun 18, 2023

A scorching-hot exoplanet scrutinized by astronomers

An international team led by Stefan Pelletier, a Ph.D. student at Université de Montréal's Trottier Institute for Research on Exoplanets announced today having made a detailed study of the extremely hot giant exoplanet WASP-76 b.

Using the MAROON-X instrument on the Gemini-North Telescope, the team was able to identify and measure the abundance of 11 chemical elements in the atmosphere of the planet.

Those include rock-forming elements whose abundances are not even known for giant planets in the Solar System such as Jupiter or Saturn. The team's study is published in the journal Nature.

"Truly rare are the times when an exoplanet hundreds of light years away can teach us something that would otherwise likely be impossible to know about our own Solar System," said Pelletier. "This is the case with this study."

A big, hot, strange world

WASP-76 b is a strange world. It reaches extreme temperatures because it is very close to its parent star, a massive star 634 light-years away in the constellation of Pisces: approximately 12 times closer than Mercury is to the Sun. With a mass similar to that of Jupiter, but almost six times bigger by volume, it is quite "puffy."

Since its discovery by the Wide Angle Search for Planets (WASP) program in 2013, many teams have studied it and identified various elements in its atmosphere. Notably, in a study also published in Nature in March 2020, a team found an iron signature and hypothesised that there could be iron rain on the planet.

Aware of these studies, Pelletier became motivated to obtain new, independent observations of WASP-76 b using the MAROON-X high-resolution optical spectrograph on the Gemini-North 8-metre Telescope in Hawai'i, part of the International Gemini Observatory, operated by NSF's NOIRLab.

"We recognized that the powerful new MAROON-X spectrograph would enable us to study the chemical composition of WASP-76 b with a level of detail unprecedented for any giant planet," says UdeM astronomy professor Björn Benneke, co-author of the study and Stefan Pelletier's PhD research supervisor.

A composition similar to the Sun's

Within the Sun, the abundances of almost all elements in the periodic table are known with great accuracy. In the giant planets in our Solar System, however, that's true for only a handful of elements, whose compositions remain poorly constrained. And this has hampered understanding of the mechanisms governing the formation of these planets.

As it is so close to its star, WASP-76 b has a temperature well above 2000°C. At these degrees, many elements that would normally form rocks here on Earth (like magnesium and iron) are vaporised and present in gaseous form in the upper atmosphere. Studying this peculiar planet enables unprecedented insight into the presence and abundance of rock-forming elements in giant planets, since in colder giant planets like Jupiter these elements are lower in the atmosphere and impossible to detect.

The abundance of many elements measured by Pelletier and his team in the exoplanet's atmosphere -- such as manganese, chromium, magnesium, vanadium, barium and calcium -- matches those of its host star as well as of our own Sun very closely.

These abundances are not random: they are the direct product of the Big Bang, followed by billions of years of stellar nucleosynthesis, so scientists measure roughly the same composition in all stars. It is, however, different from the composition of rocky planets like Earth, which are formed in a more complex manner.

The results of this new study indicate that giant planets could maintain an overall composition that reflects that of the protoplanetary disc from which they formed.

Depletion of other elements very interesting

However, other elements were depleted in the planet compared to the star -- a result Pelletier found particularly interesting.

"These elements that appear to be missing in WASP-76 b's atmosphere are precisely those that require higher temperatures to vaporise, like titanium and aluminium, " he said. "Meanwhile, the ones that matched our predictions, like manganese, vanadium, or calcium, all vaporise at slightly lower temperatures."

The discovery team's interpretation is that the observed composition of the upper atmospheres of giant planets can be extremely sensitive to temperature. Depending on an element's temperature of condensation, it will be in gas form and present in the upper part of the atmosphere, or condense into liquid form where it will sink to deeper layers. When in gas form, it plays an important role in absorbing light and can be seen in astronomers' observations. When condensed, it cannot be detected by astronomers and becomes completely absent from their observations.

"If confirmed, this finding would mean that two giant exoplanets that have slightly different temperatures from one another could have very different atmospheres, " said Pelletier. "Kind of like two pots of water, one at -1°C that is frozen, and one that is at +1°C that is liquid. For example, calcium is observed on WASP-76 b, but it may not be on a slightly colder planet."

First detection of vanadium oxide

Another interesting finding by Pelletier's team is the detection of a molecule called vanadium oxide. This is the first time it has been unambiguously detected on an exoplanet, and is of great interest to astronomers because they know it can have a big impact on hot giant planets.

"This molecule plays a similar role to ozone in Earth's atmosphere: it is extremely efficient at heating up the upper atmosphere," explained Pelletier. "This causes the temperatures to increase as a function of altitude, instead of decreasing as is typically seen on colder planets."

One element, nickel, is clearly more abundant in the exoplanet's atmosphere than what the astronomers were expecting. Many hypotheses could explain that; one is that WASP-76 b could have accreted material from a planet similar to Mercury. In our Solar System, the small rocky planet is enriched with metals like nickel because of how it was formed.

Pelletier's team also found that the asymmetry in iron absorption between the east and west hemispheres of WASP-76 b reported in previous studies is similarly present for many other elements. This means the underlying phenomenon causing this is thus probably a global process such as a difference in temperature or clouds being present on one side of the planet but not the other, rather than being the result of condensation into liquid form as was previously suggested.

Confirming and leveraging lessons learned

Pelletier and his team are very keen to learn more about this exoplanet and other ultra-hot giant planets, in part to confirm their hypothesis about the vastly different atmospheres that could prevail on planets differing slightly in temperature.

They also hope other researchers will leverage what they learned from this giant exoplanet and apply it to better our understanding of our own Solar System planets and how they came to be.

Read more at Science Daily

We've pumped so much groundwater that we've nudged Earth's spin

By pumping water out of the ground and moving it elsewhere, humans have shifted such a large mass of water that the Earth tilted nearly 80 centimeters (31.5 inches) east between 1993 and 2010 alone, according to a new study published in Geophysical Research Letters, AGU's journal for short-format, high-impact research with implications spanning the Earth and space sciences.

Based on climate models, scientists previously estimated humans pumped 2,150 gigatons of groundwater, equivalent to more than 6 millimeters (0.24 inches) of sea level rise, from 1993 to 2010. But validating that estimate is difficult.

One approach lies with the Earth's rotational pole, which is the point around which the planet rotates. It moves during a process called polar motion, which is when the position of the Earth's rotational pole varies relative to the crust. The distribution of water on the planet affects how mass is distributed. Like adding a tiny bit of weight to a spinning top, the Earth spins a little differently as water is moved around.

"Earth's rotational pole actually changes a lot," said Ki-Weon Seo, a geophysicist at Seoul National University who led the study. "Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole."

Water's ability to change the Earth's rotation was discovered in 2016, and until now, the specific contribution of groundwater to these rotational changes was unexplored. In the new study, researchers modeled the observed changes in the drift of Earth's rotational pole and the movement of water -- first, with only ice sheets and glaciers considered, and then adding in different scenarios of groundwater redistribution.

The model only matched the observed polar drift once the researchers included 2150 gigatons of groundwater redistribution. Without it, the model was off by 78.5 centimeters (31 inches), or 4.3 centimeters (1.7 inches) of drift per year.

"I'm very glad to find the unexplained cause of the rotation pole drift," Seo said. "On the other hand, as a resident of Earth and a father, I'm concerned and surprised to see that pumping groundwater is another source of sea-level rise."

"This is a nice contribution and an important documentation for sure," said Surendra Adhikari, a research scientist at the Jet Propulsion Laboratory who was not involved in this study. Adhikari published the 2016 paper on water redistribution impacting rotational drift. "They've quantified the role of groundwater pumping on polar motion, and it's pretty significant."

The location of the groundwater matters for how much it could change polar drift; redistributing water from the midlatitudes has a larger impact on the rotational pole. During the study period, the most water was redistributed in western North America and northwestern India, both at midlatitudes.

Countries' attempts to slow groundwater depletion rates, especially in those sensitive regions, could theoretically alter the change in drift, but only if such conservation approaches are sustained for decades, Seo said.

The rotational pole normally changes by several meters within about a year, so changes due to groundwater pumping don't run the risk of shifting seasons. But on geologic time scales, polar drift can have an impact on climate, Adhikari said.

Read more at Science Daily

Engineers develop a soft, printable, metal-free electrode

Do an image search for "electronic implants," and you'll draw up a wide assortment of devices, from traditional pacemakers and cochlear implants to more futuristic brain and retinal microchips aimed at augmenting vision, treating depression, and restoring mobility.

Some implants are hard and bulky, while others are flexible and thin. But no matter their form and function, nearly all implants incorporate electrodes -- small conductive elements that attach directly to target tissues to electrically stimulate muscles and nerves.

Implantable electrodes are predominantly made from rigid metals that are electrically conductive by nature. But over time, metals can aggravate tissues, causing scarring and inflammation that in turn can degrade an implant's performance.

Now, MIT engineers have developed a metal-free, jelly-like material that is as soft and tough as biological tissue and can conduct electricity similarly to conventional metals. The material can be made into a printable ink, which the researchers patterned into flexible, rubbery electrodes. The new material, which is a type of high-performance conducting polymer hydrogel, may one day replace metals as functional, gel-based electrodes, with the look and feel of biological tissue.

"This material operates the same as metal electrodes but is made from gels that are similar to our bodies, and with similar water content," says Hyunwoo Yuk SM '16 PhD '21, co-founder of SanaHeal, a medical device startup. "It's like an artificial tissue or nerve."

"We believe that for the first time, we have a tough, robust, Jell-O-like electrode that can potentially replace metal to stimulate nerves and interface with the heart, brain, and other organs in the body," adds Xuanhe Zhao, professor of mechanical engineering and of civil and environmental engineering at MIT.

Zhao, Yuk, and others at MIT and elsewhere report their results in Nature Materials. The study's co-authors include first author and former MIT postdoc Tao Zhou, who is now an assistant professor at Penn State University, and colleagues at Jiangxi Science and Technology Normal University and Shanghai Jiao Tong University.

A true challenge

The vast majority of polymers are insulating by nature, meaning that electricity does not pass easily through them. But there exists a small and special class of polymers that can in fact pass electrons through their bulk. Some conductive polymers were first shown to exhibit high electrical conductivity in the 1970s -- work that was later awarded a Nobel Prize in Chemistry.

Recently, researchers including those in Zhao's lab have tried using conductive polymers to fabricate soft, metal-free electrodes for use in bioelectronic implants and other medical devices. These efforts have aimed to make soft yet tough, electrically conductive films and patches, primarily by mixing particles of conductive polymers, with hydrogel -- a type of soft and spongy water-rich polymer.

Researchers hoped the combination of conductive polymer and hydrogel would yield a flexible, biocompatible, and electrically conductive gel. But the materials made to date were either too weak and brittle, or they exhibited poor electrical performance.

"In gel materials, the electrical and mechanical properties always fight each other," Yuk says. "If you improve a gel's electrical properties, you have to sacrifice mechanical properties, and vice versa. But in reality, we need both: A material should be conductive, and also stretchy and robust. That was the true challenge and the reason why people could not make conductive polymers into reliable devices entirely made out of gel."

Electric spaghetti

In their new study, Yuk and his colleagues found they needed a new recipe to mix conductive polymers with hydrogels in a way that enhanced both the electrical and mechanical properties of the respective ingredients.

"People previously relied on homogenous, random mixing of the two materials," Yuk says.

Such mixtures produced gels made of randomly dispersed polymer particles. The group realized that to preserve the electrical and mechanical strengths of the conductive polymer and the hydrogel respectively, both ingredients should be mixed in a way that they slightly repel -- a state known as phase separation. In this slightly separated state, each ingredient could then link its respective polymers to form long, microscopic strands, while also mixing as a whole.

"Imagine we are making electrical and mechanical spaghetti," Zhao offers. "The electrical spaghetti is the conductive polymer, which can now transmit electricity across the material because it is continuous. And the mechanical spaghetti is the hydrogel, which can transmit mechanical forces and be tough and stretchy because it is also continuous."

The researchers then tweaked the recipe to cook the spaghettified gel into an ink, which they fed through a 3D printer, and printed onto films of pure hydrogel, in patterns similar to conventional metal electrodes.

"Because this gel is 3D-printable, we can customize geometries and shapes, which makes it easy to fabricate electrical interfaces for all kinds of organs," says first-author Zhou.

The researchers then implanted the printed, Jell-O-like electrodes onto the heart, sciatic nerve, and spinal cord of rats. The team tested the electrodes' electrical and mechanical performance in the animals for up to two months and found the devices remained stable throughout, with little inflammation or scarring to the surrounding tissues. The electrodes also were able to relay electrical pulses from the heart to an external monitor, as well as deliver small pulses to the sciatic nerve and spinal cord, which in turn stimulated motor activity in the associated muscles and limbs.

Going forward, Yuk envisions that an immediate application for the new material may be for people recovering from heart surgery.

"These patients need a few weeks of electrical support to avoid heart attack as a side effect of surgery," Yuk says. "So, doctors stitch a metallic electrode on the surface of the heart and stimulate it over weeks. We may replace those metal electrodes with our gel to minimize complications and side effects that people currently just accept."

The team is working to extend the material's lifetime and performance. Then, the gel could be used as a soft electrical interface between organs and longer-term implants, including pacemakers and deep-brain stimulators.

Read more at Science Daily