Glow in the visible range detected for the first time in the Martian night

An international team led by scientists from the University of Liège has observed, for the first time in the visible range, a glow on the night side of the planet Mars. These new observations provide a better understanding of the dynamics of the upper atmosphere of the Red Planet and its variations throughout the year.

A scientific team led by researchers from the Laboratory for Planetary and Atmospheric Physics (LPAP) at the University of Liège (BE) has just observed, for the first time, lights in the night sky over Mars using the UVIS-NOMAD instrument on board the Trace Gas Orbiter (TGO) satellite of the European Space Agency (ESA). This instrument is part of the NOMAD spectrometer suite developed at the Royal Institute for Space Aeronomy in Uccle, and tested and calibrated at the Liège Space Centre. It was inserted into circular Martian orbit at an altitude of 400 km in 2008.

Initially designed to map the ozone layer surrounding the planet in the ultraviolet, UVIS-NOMAD covers a spectral range extending from the near ultraviolet to red. For this purpose, the instrument is usually oriented towards the centre of the planet and observes sunlight reflected by the planetary surface and atmosphere. Based on a proposal from our laboratory, the instrument was oriented towards the limb of the planet in order to observe its atmosphere from the edge," explains Jean-Claude Gérard, planetologist at ULiège. Back in 2020, we were already able to detect the presence of a green emission between 40 and 150 km in altitude, present during the Martian day. This was due to the dissociation of the CO2 molecule, the main constituent of the atmosphere, by ultraviolet solar radiation."

A long journey for oxygen atoms

The TGO satellite, when observing the atmosphere at night, has just detected a new emission between 40 and 70 km altitude. This emission is due to the recombination of oxygen atoms created in the summer atmosphere and carried by the winds towards the high winter latitudes," explains Lauriane Soret, a researcher at LPAP. There, the atoms recombine on contact with CO2 to reform an O2 molecule in an excited state that relaxes and emits light in the visible range." This light emission is concentrated in the polar regions to the north and south, where the oxygen atoms converge in the downward branch of the gigantic trajectory from the opposite hemisphere. The intensity of the emission is high, in the visible range. This process seems to be reversed every half Martian year*, and the luminosity then changes hemisphere. A similar emission was analysed on Venus by the same team using images from the Venus Express satellite. On Venus, the atoms travel from the sunlit side to the dark side where they emit the same glow as on Mars.

ULiège researchers at the forefront

LPAP researchers played a key role in these observations. After highlighting the presence of a layer of green light surrounding the planet on the day side, they identified the night-time emission. The study will be continued during the TGO mission and will provide us with valuable information about the dynamics of the Martian upper atmosphere and its variations over the course of the Martian year," continues Lauriane Soret. We have noticed that another ultraviolet emission due to the nitric oxide (NO) molecule is also observed by UVIS in the same regions. Comparing the two emissions will enable us to refine the diagnosis and identify the processes involved.

The NO molecule also emits light when oxygen and nitrogen atoms recombine. As with the radiation from the O2 molecule, the atoms are formed in sunlight, transported by the winds to the other hemisphere and recombine during the downward motion in the polar regions.

These new observations are unexpected and interesting for future journeys to the Red Planet," enthuses Jean-Claude Gérard. The intensity of the night glow in the polar regions is such that simple and relatively inexpensive instruments in Martian orbit could map and monitor atmospheric flows. A future ESA mission could carry a camera for global imaging. In addition, the emission is sufficiently intense to be observable during the polar night by future astronauts in orbit or from the Martian ground'.

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Greenland's glacier retreat rate has doubled over past two decades

Greenland's thousands of peripheral glaciers have entered a new and widespread state of rapid retreat, a Northwestern University and University of Copenhagen study has found.

To piece together the magnitude of glacier retreat, the research team combined satellite images with historical aerial photographs of Greenland's coastline, which is dotted with thousands of glaciers that are separate from the island's massive central ice sheet. With these one-of-a-kind data, the researchers documented changes in the lengths of more than 1,000 of the country's glaciers over the past 130 years.

Although glaciers in Greenland have experienced retreat throughout the last century, the rate of their retreat has rapidly accelerated over the last two decades. According to the multiyear collaborative effort between the United States and Denmark, the rate of glacial retreat during the 21st century is twice as fast as retreat during the 20th century. And, despite the range of climates and topographical characteristics across Greenland, the findings are ubiquitous, even among Earth's northernmost glaciers.

The findings underscore the region's sensitivity to rising temperatures due to human-caused climate change.

The study will be published on Thursday (Nov. 9) in the journal Nature Climate Change.

"Our study places the recent retreat of peripheral glaciers across Greenland's diverse climate zones into a century-long perspective and suggests that their rate of retreat in the 21st century is largely unprecedented on a century timescale," said Laura Larocca, the study's first author. "The only major possible exception are glaciers in northeast Greenland, where it looks like recent increases in snowfall might be slowing retreat."

The study finds that climate change explains the accelerated glacier retreat and that glaciers across Greenland respond quickly to changing temperatures. This highlights the importance of slowing global warming.

"Our activities over the next couple decades will greatly affect these glaciers. Every bit of temperature increase really matters," Larocca said.

"This work is based on vast analyses of satellite imagery and digitization of thousands of historical aerial photographs -- some taken during early mapping expeditions of Greenland from open-cockpit airplanes," said Northwestern's Yarrow Axford, a senior author on the study. "Those old photos extend the dataset back prior to the satellite era, when widespread observations of the cryosphere are rare. It's quite extraordinary that we can now provide long-term records for hundreds of glaciers, finally giving us an opportunity to document Greenland-wide glacier response to climate change over more than a century."

Axford is the William Deering Professor of Geological Sciences at Northwestern's Weinberg College of Arts and Sciences. When the research began, Larocca was a Ph.D. candidate in Axford's laboratory. Now, Larocca is a NOAA Climate & Global Change Postdoctoral Fellow hosted at Northern Arizona University. She will join Arizona State University's School of Ocean Futures as an assistant professor in January 2024.

While climate change's effects on Greenland are well studied, most researchers focus on the Greenland Ice Sheet, which covers roughly 80% of the country. But fluctuations in Greenland's peripheral glaciers -- the smaller ice masses distinct from the ice sheet that dot the country's coastline -- are widely undocumented, in part due to a lack of observational data.

Prior to the launch of Earth-observing satellites in the 1970s, researchers did not have a full understanding of how temperature changes affected Greenland's glaciers. Widespread and detailed observational records simply did not exist -- or so researchers thought. A breakthrough came about 15 years ago when long-forgotten aerial photographs of Greenland's coastline were rediscovered in a castle outside Copenhagen. Now housed within the Danish National Archives, the images enabled study senior author Anders Bjørk, an assistant professor at the University of Copenhagen, to begin constructing the glaciers' history.

"Starting in the 1930s, Danish pilots clad in polar bear-fur suits set out on aerial mapping campaigns of Greenland and ended up collecting over 200,000 photos of the island's coastline," Larocca said. "They also unintentionally captured the state of Greenland's peripheral glaciers."

In previous studies, Bjørk and his collaborators digitized and analyzed photos to study 361 glaciers in the southeast, northwest and northeast regions of Greenland. In the new study, Larocca, Axford and their team added records for 821 more glaciers in the south, north and west regions and extended Bjørk's records to present day.

As a part of this effort, the team digitized thousands of paper-copy aerial photographs taken from open-cockpit planes and collected imagery from multiple satellites. The researchers also removed terrain distortion and used geo-referencing techniques to place the photos at the correct locations on Earth.

"There really aren't any automated processes to digitize all these photos," said Larocca, who began the project in 2018. "A project like this takes a lot of people and a lot of manual labor to scan and digitize all these analog air photos. Then, we had to do a lot of preprocessing work before making our measurements."

Larocca, Axford and their team also extended records further back in time by leveraging clues hidden within the landscape. When glaciers grow larger and then retreat, they leave behind a terminal moraine (sediment transported and deposited by a glacier, often in the form of a long ridge). Locating these moraines enabled the researchers to map older glacier extents before pilots took their first flyover photos in the early 1930s.

Using the late 20th-century imagery as a baseline, Larocca, Axford and their team also calculated the percentage of length that glaciers have lost over the past 20 years. They found that, on average, glaciers in south Greenland lost 18% of their lengths, while glaciers in other regions lost between 5-10% of their lengths over the past 20 years.

As global temperatures increase, it has become more imperative than ever to better understand how these melting glaciers will affect rising sea levels and reliable sources of fresh water.

Read more at Science Daily

Found at last: Bizarre, egg-laying mammal finally rediscovered after 60 years

More than sixty years after it was last recorded, an expedition team has rediscovered an iconic, egg-laying mammal in one of the most unexplored regions of the world. Attenborough's long-beaked echidna, named after famed broadcaster Sir David Attenborough, was captured for the first time in photos and video footage using remote trail cameras set up in the Cyclops Mountains of Indonesia's Papua Province.

Alongside the echidna's rediscovery, the expedition -- a partnership between the University of Oxford, Indonesian NGO Yayasan Pelayanan Papua Nenda (YAPPENDA), Cenderawasih University (UNCEN), Papua BBKSDA, and the National Research and Innovation Agency of Indonesia (BRIN), Re:Wild -- made many other remarkable finds. These included Mayr's honeyeater, a bird lost to science since 2008; an entirely new genus of tree-dwelling shrimp; countless new species of insects; and a previously unknown cave system. This was despite the difficulties posed by extremely inhospitable terrain, including venomous animals, blood-sucking leeches, malaria, earthquakes, and exhausting heat.

One of the world's most unusual mammals finally caught on film

Recorded by science only once in 1961, Attenborough's long-beaked echidna is a monotreme: an evolutionarily distinct group of egg-laying mammals that includes the platypus. This echidna species is so special because it is one of only five remaining species of monotremes, the sole guardians of this remarkable branch of the tree of life. Echidnas are notoriously difficult to find since they are nocturnal, live in burrows, and tend to be very shy. Attenborough's long-beaked echidna has never been recorded anywhere outside the Cyclops Mountains, and is currently classified as Critically Endangered on the IUCN Red List of Threatened Species

To give themselves the best chance of finding one, the team deployed over 80 trail cameras, making multiple ascents of the mountains, and climbing more than 11,000 meters (more than the height of Everest) in the process. For almost the entire four weeks that the team spent in the forest, the cameras recorded no sign of the echidna. On the last day, with the last images on the final memory card, the team obtained their shots of the elusive mammal -- the first ever photographs of Attenborough's echidna. The identification of the species was later confirmed by Professor Kristofer Helgen, mammalogist and chief scientist and director of the Australian Museum Research Institute (AMRI).

Dr James Kempton, a biologist from the University of Oxford who conceived of and led the expedition, said: 'Attenborough's long-beaked echidna has the spines of a hedgehog, the snout of an anteater, and the feet of a mole. Because of its hybrid appearance, it shares its name with a creature of Greek mythology that is half human, half serpent. The reason it appears so unlike other mammals is because it is a member of the monotremes -- an egg-laying group that separated from the rest of the mammal tree-of-life about 200 million years ago.'

'The discovery is the result of a lot of hard work and over three and a half years of planning,' he added. 'A key reason why we succeeded is because, with the help of YAPPENDA, we have spent years building a relationship with the community of Yongsu Sapari, a village on the north coast of the Cyclops Mountains. The trust between us was the bedrock of our success because they shared with us the knowledge to navigate these treacherous mountains, and even allowed us to research on lands that have never before felt the tread of human feet.'

A treasure trove of discoveries

Alongside searching for the echidna, the expedition carried out the first comprehensive assessment of invertebrate, reptile, amphibian, and mammal life in the Cyclops Mountains. With the support of local guides in the expedition team, the scientists were able to create makeshift labs in the heart of the jungle with benches and desks made from forest branches and vines.

By combining scientific techniques with the Papuan team members' experience and knowledge of the forest, the team made a wealth of new discoveries. These included several dozens of insect species completely new to science and the rediscovery of Mayr's honeyeater (Ptiloprora mayri), a bird lost to science since 2008 and named after famed evolutionary biologist Ernst Mayr.

An extraordinary finding was an entirely new genus of ground and tree-dwelling shrimp. 'We were quite shocked to discover this shrimp in the heart of the forest, because it is a remarkable departure from the typical seaside habitat for these animals,' said Dr Leonidas-Romanos Davranoglou (a Leverhulme Trust Postdoctoral Fellow at the Oxford University Museum of Natural History), lead entomologist for the expedition. 'We believe that the high level of rainfall in the Cyclops Mountains means the humidity is great enough for these creatures to live entirely on land.'

The team also revealed a treasure trove of underground species, including blind spiders, blind harvestman, and a whip scorpion, all new to science, in a previously unexplored cave system. This astonishing discovery was made on one of the sacred peaks above Yongsu Sapari where the team had been given special permission to do research. People rarely tread here, and the striking cave system was chanced upon when one team member fell through a moss-covered entrance.

'A beautiful but dangerous land'

Extremely challenging and, at times, life-threatening conditions were at the background of these discoveries. During one of the trips to the cave system, a sudden earthquake forced the team to evacuate. Dr Davranoglou broke his arm in two places, one member contracted malaria, and another had a leech attached to his eye for a day and a half before it was finally removed at a hospital. Throughout the expedition, members were beset by biting mosquitoes and ticks, and faced constant danger from venomous snakes and spiders. Making any progress through the jungle was a slow and exhausting process, with the team sometimes having to cut paths where no humans had ever been before.

'Though some might describe the Cyclops as a "Green Hell," I think the landscape is magical, at once enchanting and dangerous, like something out of a Tolkien book' said Dr Kempton. 'In this environment, the camaraderie between the expedition members was fantastic, with everyone helping to keep up morale. In the evening, we exchanged stories around the fire, all the while surrounded by the hoots and peeps of frogs.'

An enduring legacy

Rediscovering the echidna is only the beginning of the expedition's mission. Attenborough's long-beaked echidna is the flagship animal of the Cyclops Mountains and a symbol of its extraordinary biodiversity. The team hope that its rediscovery will help bring attention to the conservation needs of the Cyclops, and Indonesian New Guinea more generally, and they are committed to supporting long-term monitoring of the echidna. Key to this work is NGO YAPPENDA, whose mission is to protect the natural environment of Indonesian New Guinea through empowerment of Indigenous Papuans. As part of the expedition team, members of YAPPENDA helped train six students from UNCEN in biodiversity surveys and camera trapping during the expedition.

Dr Davranoglou said: 'Tropical rainforests are among the most important and most threatened terrestrial ecosystems. It is our duty to support our colleagues on the frontline through exchanging knowledge, skills, and equipment.'

With the team having only sorted a fraction of the material collected on the expedition, they expect that the coming months will yield even more new species. The intention is to name many of these after the Papuan members of the expedition.

Besides animal specimens, the team also collected over 75 kg of rock samples for geological analysis, which was led by the expedition's chief geologist, Max Webb, from Royal Holloway University, London. These could help answer many questions about how and when the Cyclops Mountains originally formed. The mountains are believed to have formed when an island arc in the Pacific Ocean collided with the New Guinea mainland about 10 million years ago. Combined with the biological findings, this geological work will help the team understand how the extraordinary biodiversity of the Cyclops came to be.

Read more at Science Daily

Machine learning gives users 'superhuman' ability to open and control tools in virtual reality

Researchers have developed a virtual reality application where a range of 3D modelling tools can be opened and controlled using just the movement of a user's hand.

The researchers, from the University of Cambridge, used machine learning to develop 'HotGestures' -- analogous to the hot keys used in many desktop applications.

HotGestures give users the ability to build figures and shapes in virtual reality without ever having to interact with a menu, helping them stay focused on a task without breaking their train of thought.

The idea of being able to open and control tools in virtual reality has been a movie trope for decades, but the researchers say that this is the first time such a 'superhuman' ability has been made possible. The results are reported in the journal IEEE Transactions on Visualization and Computer Graphics.

Virtual reality (VR) and related applications have been touted as game-changers for years, but outside of gaming, their promise has not fully materialised. "Users gain some qualities when using VR, but very few people want to use it for an extended period of time," said Professor Per Ola Kristensson from Cambridge's Department of Engineering, who led the research. "Beyond the visual fatigue and ergonomic issues, VR isn't really offering anything you can't get in the real world."

Most users of desktop software will be familiar with the concept of hot keys -- command shortcuts such as ctrl-c to copy and ctrl-v to paste. While these shortcuts omit the need to open a menu to find the right tool or command, they rely on the user having the correct command memorised.

"We wanted to take the concept of hot keys and turn it into something more meaningful for virtual reality -- something that wouldn't rely on the user having a shortcut in their head already," said Kristensson, who is also co-Director of the Centre for Human-Inspired Artificial Intelligence.

Instead of hot keys, Kristensson and his colleagues developed 'HotGestures', where users perform a gesture with their hand to open and control the tool they need in 3D virtual reality environments.

For example, performing a cutting motion opens the scissor tool, and the spray motion opens the spray can tool. There is no need for the user to open a menu to find the tool they need, or to remember a specific shortcut. Users can seamlessly switch between different tools by performing different gestures during a task, without having to pause their work to browse a menu or to press a button on a controller or keyboard.

"We all communicate using our hands in the real world, so it made sense to extend this form of communication to the virtual world," said Kristensson.

For the study, the researchers built a neural network gesture recognition system that can recognise gestures by performing predictions on an incoming hand joint data stream. The system was built to recognise ten different gestures associated with building 3D models: pen, cube, cylinder, sphere, palette, spray, cut, scale, duplicate and delete.

The team carried out two small studies where participants used HotGestures, menu commands or a combination. The gesture-based technique provided fast and effective shortcuts for tool selection and usage. Participants found HotGestures to be distinctive, fast, and easy to use while also complementing conventional menu-based interaction. The researchers designed the system so that there were no false activations -- the gesture-based system was able to correctly recognise what was a command and what was normal hand movement. Overall, the gesture-based system was faster than a menu-based system.

"There is no VR system currently available that can do this," said Kristensson. "If using VR is just like using a keyboard and a mouse, then what's the point of using it? It needs to give you almost superhuman powers that you can't get elsewhere."

The researchers have made the source code and dataset publicly available so that designers of VR applications can incorporate it into their products.

"We want this to be a standard way of interacting with VR," said Kristensson. "We've had the tired old metaphor of the filing cabinet for decades. We need new ways of interacting with technology, and we think this is a step in that direction. When done right, VR can be like magic."

Read more at Science Daily

New dates for landslides reveal past Seattle fault earthquakes

New maps of more than 1,000 deep-seated landslides in the Puget Lowlands of Washington State provide evidence of the last major earthquake along the Seattle Fault about 1,100 years ago -- and may also hold traces of older earthquakes along the fault.

Clusters of landslides offer a potential record of earthquakes, if researchers can determine when the landslides occurred. The new study published in the Bulletin of the Seismological Society of America combines information about the location of these Puget Lowlands landslides along with new dates obtained from measuring the surface roughness of the landslides.

The combination of data helped Erich Herzig of the University of Washington and colleagues uncover strong evidence of the last known major Seattle Fault earthquake, thought to be a magnitude 7 to 7.5 event. (A recent study suggested that there may have even been a double earthquake at the time in the region.)

The researchers compared their new landslide map to ground motions generated by different Seattle Fault earthquake scenarios. The scenario that best matches the landslide clusters, they found, is one that produces the strongest shaking in a west to east band from west Seattle to Mercer Island and the bluffs bordering Puget Sound.

"While other studies have refined our understanding of the overall strength or timing of the 1,100-year-old Seattle Fault earthquake, to our knowledge, this is the first study that has attempted to characterize the locations of strong shaking," Herzig said.

Herzig and colleagues also uncovered other landslide clusters at 4600-4200 years ago, 4000-3800 years ago, 2800 to 2600 years ago, and 2200 to 2000 years ago that could be signs of older Seattle Fault earthquakes.

They began by mapping more than 1,000 deep-seated landslides across the Puget Lowlands -- deep-seated refers to landslides where the slide plane lays below the roots of the trees -- using a technique called airborne lidar.

"Airborne lidar is a technology where a plane mounted with lasers is used to measure the shape of the land surface in detail, even through vegetation," Herzig explained. "In the past few years this technology has been able to produce maps at one meter resolution or better, which is essential for measuring roughness as we do in the paper."

Measuring the roughness of a landslide surface is a relatively new technique used by scientists to estimate the age of a landslide, he noted. The general idea is that ground surfaces roughen after the mass movement of rocks and soil, so that landslide deposits are the roughest right after the landslide occurs and become smoother over time. By modeling this age-roughness relationship, with information from landslides dated by other means such as carbon dating, researchers can estimate when a particular landslide took place.

For the landslides in the BSSA study, Herzig and colleagues calculated roughness by measuring variations in the land surface in a 15-meter-wide circle. Carbon dating of wood at some landslides provided data for calibrating the landslide ages.

The researchers uncovered spatial patterns in the landslides that correlate with the ground motions predicted by models of Seattle Fault earthquakes. They also noted that the timing of landslides in the Puget Lowland fits better with a model of a pulse of landslides at the time of the last major Seattle Fault earthquake, rather than a model of landslides happening steadily through time.

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Yeast with an over half synthetic genome is created in the lab

Researchers have combined over seven synthetic chromosomes that were made in the lab into a single yeast cell, resulting in a strain with more than 50% synthetic DNA that survives and replicates similarly to wild yeast strains. The team present the half-synthetic yeast November 8 in the journal Cell as part of a collection of papers across Cell, Molecular Cell,and Cell Genomics that showcase the Synthetic Yeast Genome Project (Sc2.0), a global consortium working to develop the first synthetic eukaryote genome from scratch. The team has now synthesized and debugged all sixteen yeast chromosomes.

"Our motivation is to understand the first principles of genome fundamentals by building synthetic genomes," says co-author and synthetic biologist Patrick Yizhi Cai of the University of Manchester, who is also senior author of two other papers in the collection. "The team has now re-written the operating system of the budding yeast, which opens up a new era of engineering biology -- moving from tinkering a handful of genes to de novo design and construction of entire genomes."

Though bacterial and viral genomes have been synthesized previously, this would be the first synthetic eukaryote genome, which introduces the complication of multiple chromosomes. The synthetic yeast is also a "designer" genome that differs substantially from the natural Saccharomyces cerevisiae (brewer's or baker's yeast) genome on which it is based.

"We decided that it was important to produce something that was very heavily modified from nature's design," says senior author and Sc2.0 leader Jef Boeke, a synthetic biologist at NYU Langone Health. "Our overarching aim was to build a yeast that can teach us new biology."

To this end, the researchers removed chunks of non-coding DNA and repetitive elements that could be considered "junk," added new snippets of DNA to help them more easily distinguish between synthesized and native genes, and introduced a built-in diversity generator called "SCRaMbLE" that shuffles the order of genes within and between chromosomes.

To increase genome stability, the team also removed many of the genes that encode transfer RNA (tRNA) and relocated them to an entirely new "neochromosome" consisting only of tRNA genes. "The tRNA neochromosome is the world's first completely de novo synthetic chromosome," says Cai. "Nothing like this exists in nature."

Since the yeast genome is organized into sixteen chromosomes, the researchers began by assembling each chromosome independently to create sixteen partially synthetic yeast strains that each contained 15 natural chromosomes and one synthetic chromosome. The next challenge was to begin combining these synthetic chromosomes into a single yeast cell.

To do this, Boeke's team started by using a method reminiscent of Mendel's peas: essentially, the researchers interbred different partially synthetic yeast strains and then searched amongst their progeny for individuals carrying both synthetic chromosomes. Though effective, this method is very slow, but the team gradually consolidated all previously synthesized chromosomes -- six full chromosomes and one chromosome arm -- into a single cell. The resulting yeast strain was more than 31% synthetic, had normal morphology, and showed only slight growth defects compared to wild-type yeast.

To more efficiently transfer specific chromosomes between yeast strains, the researchers developed a new method called chromosome substitution that is discussed in another paper in the new collection. As a proof of concept, they used chromosome substitution to transfer a newly synthesized chromosome (chromosome IV, the largest of all the synthetic chromosomes), resulting in a yeast cell with 7.5 synthetic chromosomes that is more than 50% synthetic.

When the synthetic chromosomes were consolidated into a single yeast strain, the team detected several genetic defects or "bugs" that were invisible in yeast strains that only carried one synthetic chromosome. "We knew in principle that this might happen -- that we might have a huge number of things that had tiny little effects and that, when you put them all together, it might result in death by a thousand cuts," says Boeke.

Some of these bugs were simply due to the additive impact of having many tiny defects within the genome, while others involved genetic interactions between genes on the different synthetic chromosomes. The researchers were able to map and fix several of these bugs and increase the synthetic yeast's fitness by using a method based on CRISPR/Cas9.

"We've now shown that we can consolidate essentially half of the genome with good fitness, which suggests that this is not going to be a big problem," says Boeke. "And from debugging, we learn new twists on the rules of life."

The next step will be to integrate the remaining synthetic chromosomes. "Now we're just this far from the finish line of having all 16 chromosomes in a single cell," says Boeke. "I like to call this the end of the beginning, not the beginning of the end, because that's when we're really going to be able to start shuffling that deck and producing yeast that can do things that we've never seen before."

Read more at Science Daily

Any activity is better for your heart than sitting -- even sleeping

The study, supported by the British Heart Foundation (BHF) and published in the European Heart Journal, is the first to assess how different movement patterns throughout the 24-hour day are linked to heart health. It is the first evidence to emerge from the international Prospective Physical Activity, Sitting and Sleep (ProPASS) consortium.

Cardiovascular disease, which refers to all diseases of the heart and circulation, is the number one cause of mortality globally. In 2021, it was responsible for one in three deaths (20.5m), with coronary heart disease alone the single biggest killer. Since 1997, the number of people living with cardiovascular disease across the world has doubled and is projected to rise further.

In this study, researchers at UCL analysed data from six studies, encompassing 15,246 people from five countries, to see how movement behaviour across the day is associated with heart health, as measured by six common indicators*. Each participant used a wearable device on their thigh to measure their activity throughout the 24-hour day and had their heart health measured.

The researchers identified a hierarchy of behaviours that make up a typical 24-hour day, with time spent doing moderate-vigorous activity providing the most benefit to heart health, followed by light activity, standing and sleeping compared with the adverse impact of sedentary behaviour.

The team modelled what would happen if an individual changed various amounts of one behaviour for another each day for a week, in order to estimate the effect on heart health for each scenario. When replacing sedentary behaviour, as little as five minutes of moderate-vigorous activity had a noticeable effect on heart health.

For a 54-year-old woman with an average BMI of 26.5, for example, a 30-minute change translated into a 0.64 decrease in BMI, which is a difference of 2.4%. Replacing 30 minutes of daily sitting or lying time with moderate or vigorous exercise could also translate into a 2.5 cm (2.7%) decrease in waist circumference or a 1.33 mmol/mol (3.6%) decrease in glycated haemoglobin.

Dr Jo Blodgett, first author of the study from UCL Surgery & Interventional Science and the Institute of Sport, Exercise & Health, said: "The big takeaway from our research is that while small changes to how you move can have a positive effect on heart health, intensity of movement matters. The most beneficial change we observed was replacing sitting with moderate to vigorous activity -- which could be a run, a brisk walk, or stair climbing -- basically any activity that raises your heart rate and makes you breathe faster, even for a minute or two."

The researchers pointed out that although time spent doing vigorous activity was the quickest way to improve heart health, there are ways to benefit for people of all abilities -- it's just that the lower the intensity of the activity, the longer the time is required to start having a tangible benefit. Using a standing desk for a few hours a day instead of a sitting desk, for example, is a change over a relatively large amount of time but is also one that could be integrated into a working routine fairly easily as it does not require any time commitment.

Those who are least active were also found to gain the greatest benefit from changing from sedentary behaviours to more active ones.

Professor Emmanuel Stamatakis, joint senior author of the study from the Charles Perkins Centre and Faculty of Medicine and Health at the University of Sydney, said: "A key novelty of the ProPASS consortium is the use of wearable devices that better differentiate between types of physical activity and posture, allowing us to estimate the health effects of even subtle variations with greater precision."

Though the findings cannot infer causality between movement behaviours and cardiovascular outcomes, they contribute to a growing body of evidence linking moderate to vigorous physical activity over 24 hours with improved body fat metrics. Further long-term studies will be crucial to better understanding the associations between movement and cardiovascular outcomes.

Professor Mark Hamer, joint senior author of the study from UCL Surgery & Interventional Science and the Institute of Sport, Exercise & Health, said: "Though it may come as no surprise that becoming more active is beneficial for heart health, what's new in this study is considering a range of behaviours across the whole 24-hour day. This approach will allow us to ultimately provide personalised recommendations to get people more active in ways that are appropriate for them."

James Leiper, Associate Medical Director at the British Heart Foundation, said: "We already know that exercise can have real benefits for your cardiovascular health and this encouraging research shows that small adjustments to your daily routine could lower your chances of having a heart attack or stroke. This study shows that replacing even a few minutes of sitting with a few minutes of moderate activity can improve your BMI, cholesterol, waist size, and have many more physical benefits.

"Getting active isn't always easy, and it's important to make changes that you can stick to in the long-term and that you enjoy -- anything that gets your heart rate up can help. Incorporating 'activity snacks' such as walking while taking phone calls, or setting an alarm to get up and do some star jumps every hour is a great way to start building activity into your day, to get you in the habit of living a healthy, active lifestyle."

Read more at Science Daily

Cracking the code: Genome sequencing reveals why songbirds are larger in colder climates

Scientists have unlocked the genetic basis underlying the remarkable variation in body size observed in song sparrows, one of North America's most familiar and beloved songbirds. This discovery also provides insights into this species' capacity to adapt to the challenges of climate change.

The study, published today in Nature Communications, used genomic sequencing to successfully pinpoint eight genetic variants, or DNA mutations, largely responsible for the nearly threefold difference in body size observed across the song sparrow range from Mexico to Alaska. For instance, song sparrows that live year-round in the Aleutian Islands can be up to three times larger than their counterparts in the coastal marshes of California.

Katherine Carbeck, the study's first author and a PhD candidate in the faculty of forestry, University of British Columbia, explains that body size varies predictably in many species that inhabit vastly different climatic conditions, aligning with "Bergmann's rule" which states that organisms in cooler climates tend to be larger as an adaptation to regulate body temperature.

"The existence of 'locally adapted' populations implies that natural selection has shaped the genetic makeup of song sparrow populations across their range, enabling individuals to survive and reproduce in drastically different climatic conditions," said Carbeck. "However, the genetic mechanisms underlying Bergmann's rule have remained elusive until now."

Whole-genome sequencing cracks the code

Carbeck and colleagues from the Cornell Lab of Ornithology, University of Alaska and Ouachita Baptist University used the power of whole-genome sequencing to decode the entire song sparrow genome and unlock its secrets.

They combed through genetic samples from the two largest song sparrow subspecies that live year-round in the Aleutian Islands, as well as two smaller subspecies: one that breeds in Alaska but migrates to warmer sites in winter, and one that lives year-round on the B.C. coast, where the Pacific Ocean maintains comparatively mild winter weather.

Their comparison of the larger and smaller-bodied subspecies revealed several candidate genes associated with body mass. By characterizing these candidates, they identified eight specific genetic variants closely linked to body mass -- aligning with Bergmann's rule.

Genetic diversity helps life adapt to climate change

The researchers suggest that revealing a genetic basis for Bergmann's rule helps us to understand how evolution, natural selection and climate have interacted throughout a species' history.

"Our results highlight the potential role habitat conservation plays in enabling the continued exchange of genes between populations -- which is important in the face of ongoing change," said Carbeck.

Dr. Jen Walsh, a study co-author and research associate at the Cornell Lab of Ornithology, added: "From a genomic perspective, identifying a small number of candidate genes with an apparently large impact on variation in body size is really interesting. The magnificent range of phenotypic diversity seen in song sparrows suggest they offer exciting opportunities to identify genes underlying a host of well-known and generally accepted eco-geographic rules."

Dr. Peter Arcese, a co-author and a professor in UBC's department of forest and conservation sciences, said the findings suggest a resilient future for these birds.

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'Biodiversity time machine' provides insights into a century of loss

Scientists have run the first proof of concept of their DNA 'time machine' to shed light on a century of environmental change in a freshwater lake -- including warming temperatures and pollution, leading to the potentially irreversible loss of biodiversity.

Their approach, which uses AI applied to DNA-based biodiversity, climate variables and pollution, could help regulators to protect the planet's existing biodiversity levels, or even improve them.

Researchers from the University of Birmingham, in collaboration with Goethe University in Frankfurt, used sediment from the bottom of a lake in Denmark to reconstruct a 100-year-old library of biodiversity, chemical pollution, and climate change levels. This lake has a history of well-documented shifts in water quality, making it a perfect natural experiment for testing the biodiversity time machine.

Publishing their findings today (7 Nov) in eLife, the experts reveal that the sediment holds a continuous record of biological and environmental signals that have changed over time -- from (semi)pristine environments at the start of the industrial revolution to the present.

The team used environmental DNA -- genetic material left behind by plants, animals, and bacteria -- to build a picture of the entire freshwater community. Assisted by AI, they analysed the information, in conjunction with climate and pollution data, to identify what could explain the historic loss of species that lived in the lake.

Principal investigator Luisa Orsini, Professor of Evolutionary Systems Biology and Environmental Omics at the University of Birmingham and Fellow of the Alan Turing Institute, explained: "We took a sediment core from the bottom of the lake and used biological data within that sediment like a time machine -- looking back in time to build a detailed picture of biodiversity over the last century at yearly resolution. By analysing biological data with climate change data and pollution levels we can identify the factors having the biggest impact on biodiversity.

"Protecting every species without impacting human production is unrealistic, but using AI we can prioritise the conservation of species that deliver ecosystem services. At the same time, we can identify the top pollutants, guiding regulation of chemical compounds with the most adverse effect. These actions can help us not only to preserve the biodiversity we have today, but potentially to improve biodiversity recovery. Biodiversity sustains many ecosystem services that we all benefit from. Protecting biodiversity mean protecting these services."

The researchers found that pollutants such as insecticides and fungicides, alongside increases in minimum temperature (a 1.2-1.5-degree increase) caused the most damage to biodiversity levels.

However, the DNA present in the sediment also showed that over the last 20 years the lake had begun to recover. Water quality improved as agricultural land use declined in the area surrounding the lake. Yet, whereas the overall biodiversity increased, the communities were not the same as in the (semi)pristine phase. This is concerning as different species can deliver different ecosystem services, and therefore their inability to return to a particular site can prevent the reinstatement of specific services.

Niamh Eastwood, lead author and PhD student at the University of Birmingham said: "The biodiversity loss caused by this pollution and the warming water temperature is potentially irreversible. The species found in the lake 100 years ago that have been lost will not all be able to return. It is not possible to restore the lake to its original pristine state, even though the lake is recovering. This research shows that if we fail to protect biodiversity, much of it could be lost forever."

Dr Jiarui Zhou, co-lead author and Assistant Professor in Environmental Bioinformatics at the University of Birmingham, said: "Learning from the past, our holistic models can help us to predict the likely loss of biodiversity under a 'business as usual' and other pollution scenarios. We have demonstrated the value of AI-based approaches for understanding historic drivers of biodiversity loss. As new data becomes available, more sophisticated AI models can be used to further improve our predictions of the causes of biodiversity loss."

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Making gluten-free, sorghum-based beers easier to brew and enjoy

Though beer is a popular drink worldwide, it's usually made from barley, which leaves those with a gluten allergy or intolerance unable to enjoy the frothy beverage. Sorghum, a naturally gluten-free grain, could be an alternative, but complex preparation steps have hampered its widespread adoption by brewers. Now, researchers reporting the molecular basis behind sorghum brewing in ACS' Journal of Proteome Research have uncovered an enzyme that could improve the future of sorghum-based beers.

Traditionally, beer brewers start with barley grains, which they malt, mash, boil and ferment to create the bubbly beverage. Barley contains gluten -- a group of proteins found in several cereal grains. Sorghum, on the other hand, lacks these proteins and behaves differently than barley during brewing. For example, strong molecular bonds make it difficult to release starches from the grains during the mash stage. And fewer enzymes are present in sorghum wort -- the liquid extracted from the mashing process -- to transform the starches into simple sugars, such as glucose, which ferments into alcohol. Even when brewers adjust the reaction conditions during these steps, the resulting beverages are still less alcoholic than barley-based beers. To help bring the alcohol content up to expected standards, Edward Kerr, Glen Fox and Benjamin Schulz investigated the molecular processes that occur during sorghum brewing and found ways to improve the final product.

The team brewed both barley and sorghum beverages, taking them through malting, mashing and fermentation steps at varying temperatures and lengths of time. At the malting stage, the samples were analyzed via mass spectrometry proteomics, which revealed the presence of many of the same enzymes in barley malt and sorghum malt; those enzymes included amylases that break down starches into maltose. After the malts were steeped with water, the resulting sorghum wort contained less maltose than barley wort, but considerably more glucose. The team attributed these differences to the enzyme compositions: Sorghum wort contains fewer amylase enzymes than barley wort but more α‑glucosidase, an enzyme that breaks down starches into glucose instead. By optimizing brewing parameters to favor the activity of α‑glucosidase, the researchers say that brewers could create sorghum wort with higher concentrations of fermentable glucose, resulting in sorghum-based beers with higher alcohol content and better overall quality.

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Why a surprising discovery, warming seas and the demise of the 'Meg' may spell trouble for more and more sharks

Some unexpected shark strandings and subsequent surprises following autopsies have, ironically, taken marine biologists millions of years back in time as they look to the future with concern. Adding chapters to an evolutionary tale involving the infamous megalodon shark (the "Meg"), they think their work suggests there are more warm-blooded sharks out there than previously believed, and -- based on the Meg's demise -- these species may be at great risk from warming seas.

Some of the most famous sharks, like the white shark or the extinct megalodon, are unusual in being among the mere ~1% of shark species to be considered warm-blooded or "regional endotherms."

It had always been thought warmer muscles help fish be powerful and athletic, with regional endothermy only seen in apex predators like the great white or giant tuna. But there has also been some debate about when regional endothermy evolved, and whether extinct species like the megalodon was warm bodied.

In a new study led by Trinity College Dublin, researchers have found that a relatively ancient (but still-living) shark species -- the smalltooth sand tiger, thought to have diverged from the Meg at least 20 million years ago -- has anatomic features suggesting it is a regional endotherm. Coming hot on the fins of a similar shock that slow-moving, filter-feeding basking sharks are also regional endotherms, the researchers now believe there are more warm-blooded sharks than science thought, and that warm bloodedness evolved quite a long time ago.

Dr Nicholas Payne from Trinity's School of Natural Sciences was senior author of the study, published this week in Biology Letters. He said:

"We think this is an important finding, because if sand tiger sharks have regional endothermy then it's likely there are several other sharks out there that are also warm-bodied.

"We used to think regional endothermy was confined to apex predators like the great white and extinct megalodon, but now we have evidence that deep water 'bottom dwelling' sand tigers, and plankton-eating basking sharks also are warm bodied. This raises plenty of new questions as to why regional endothermy evolved, but it might also have important conservation implications."

The research team (including scientists from University of Pretoria, ZSL, University of Zurich, Swansea University, Smithsonian Tropical Research Institute and University College Dublin College of Agriculture Food Science and Veterinary Medicine) undertook dissections of dead smalltooth sand tiger sharks that washed up in Ireland and the UK in making their discoveries.

Dr Haley Dolton, also from Trinity, was lead author of the study. She said:

"Our understanding of science continually grows and it's becoming clear that whenever regional endothermy evolved in the past it has been retained in a growing number of shark species with very different life styles. When we first realised that the smalltooth tigers have traits associated with regional endotherms I thought 'here we go again!', but the next time we see it in another species I might be a little less shocked.

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Mystery resolved: Black hole feeding and feedback at the center of an active galaxy

An international research team led by Takuma Izumi, an assistant professor at the National Astronomical Observatory of Japan, has observed in high resolution (approximately 1 light year) the active galactic nucleus of the Circinus Galaxy -- one of the closest major galaxies to the Milky Way. The observation was made possible by the Atacama Large Millimeter/Submillimeter Array (ALMA) astronomical observatory in Chile.

This breakthrough marks the world's first quantitative measurement at this scale of gas flows and their structures of a nearby supermassive black hole in all phase gases, including plasma, atomic, and molecular. Such high resolution allowed the team to team to capture the accretion flow heading towards the supermassive black hole, revealing that this accretion flow is generated by a physical mechanism known as 'gravitational instability.' Furthermore, the team also found that a significant portion of this accretion flow does not contribute to the growth of the black hole. Instead, most of the gas is expelled from the vicinity of the black hole as atomic or molecular outflows, and returns to the gas disk to participate again into an accretion flow towards the black hole, much like how water gets recycled in a water fountain. These findings represent a crucial advancement towards a greater understanding of the growth mechanisms of supermassive black holes.

These observation results were published in Science on November 2, 2023.

'Supermassive black holes,' with masses exceeding a million times that of the Sun, exist at the centers of many galaxies. But astronomers have long pondered the mechanisms responsible their formation. One proposed mechanism, as outlined in previous research, suggests that gas accretes onto the black hole as it gravitates towards the center of the host galaxy.

As gas approaches the supermassive black holes, the intense gravitational pull of the black hole causes the gas to accelerate. The resulting increase in friction between gas particles leads to the gas heating up to temperatures as high as several million degrees and results in the emission of brilliant light. Known as an active galactic nucleus (AGN), the brightness can at times surpass the combined light of all the stars in the galaxy. Interestingly, a portion of the gas that falls towards the black hole (accretion flow) is thought to be blown away by the immense energy of this active galactic nucleus, leading to outflows.

Previous theoretical and observational studies have provided detailed insights into gas accretion mechanisms from the 100,000 light-years scale down to a scale of a few hundred light-years at the center. However, gas accretion occurs a few dozen light-years from the galactic center. This limited spacial scale has hindered further understanding of the accretion process. For instance, to comprehend quantitatively the growth of black holes, it is necessary to measure the accretion flow rate (how much gas is flowing in) and to determine the amounts and types of gases (plasma, atomic gas, molecular gas) that are expelled as outflows at that small scale. Unfortunately, observational understanding has not progressed significantly until now.

"Observations of multiphase gases can provide a more comprehensive and thorough understanding of the distribution and dynamics of matter around a black hole and our observation marks the highest resolution ever achieved for multiphase gas observations in an active galactic nucleus," points out Izumi.

Izumi and his colleagues initially captured, for the first time, the accretion flow heading towards the supermassive black hole within the high-density gas disk that extends over several light-years from the galactic center. Identifying this accretion flow had long been a challenge due to the small scale of the region and the complex motions of gas near the galactic center. However, the research team pinpointed the location where the foreground molecular gas was absorbing the light from the active galactic nucleus shining brightly in the background. Detailed analysis revealed that this absorbing material is moving away from Earth. As the absorbing material consistently resides between the active galactic nucleus and Earth, this indicates that the team has successfully captured the accretion flow heading toward the active galactic nucleus.

The study also elucidated the physical mechanism responsible for inducing this gas accretion. The observed gas disk exhibited a gravitational force so substantial that it could not be sustained by the pressure calculated from the gas disk's motion. When this situation occurs, the gas disk collapses under its own weight, forming complex structures and losing its ability to maintain stable motion at the galactic center. Consequently, the gas rapidly falls towards the central black hole, A phenomenon known as "gravitational instability" at the heart of the galaxy.

Furthermore, the study advanced quantitative understanding of gas flows around the active galactic nucleus. By considering the density of the observed gas and the velocity of the accretion flow, the researchers were able to calculate the rate at which gas is supplied to the black hole. Surprisingly, this rate was found to be 30 times greater than what is needed to sustain the active galactic nucleus. In other words, the majority of the accretion flow at the 1-light-year scale around the galactic center was not contributing to the growth of the black hole.

So, where did this surplus gas go? High-sensitivity observations of all phase gases with ALMA detected outflows from the active galactic nucleus. Quantitative analysis revealed that the majority of the gas flowing towards the black hole was expelled as atomic or molecular outflows. However, due to their slow velocities, they couldn't escape the gravitational pull of the black hole and eventually returned to the gas disk. There, they were recycled into an accretion flow toward the black hole, completing a fascinating gas recycling process at the galactic center.

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Africa's dangerous air pollution levels are a global problem, says new research

A new report in Nature Geoscience has brought to light the challenge of air pollution levels in Africa and why international action is needed to combat it.

Over the last 50 years African nations have suffered from rapidly deteriorating air quality, making their cities some of the most polluted in the world. Particulate matter concentration levels are now five to ten levels greater than that recommended by the World Health Organisation, with the situation predicted to worsen as populations grow and industrialization accelerates.

However, far too little has been done to try and combat the dangerous air quality with just 0.01% of global air pollution funding currently spent in Africa.

The new perspective piece from the University of Birmingham, the University of Cambridge, Imperial College London, South Eastern Kenya University and the African Centre for Clean Air, published today (7 Nov) in Nature Geoscience, argues that tackling this issue requires collective efforts from African countries, regionally tailored solutions, and global collaboration.

Francis Pope, Professor of Atmospheric Science at the University of Birmingham and one of the co-authors, said: "The burning of biomass fuel for cooking, heating, and lighting, the crude oil exploitation and coal mining industries, and old vehicles being shipped in from Europe are all causes for the poor air quality in African nations. This dangerous air can cause complex and sometimes deadly health issues for those breathing it in. If this wasn't enough of a reason to tackle this issue, air pollution in Africa is not just a problem for people living on the continent, but for the wider world, limiting the ability to meet global climate targets and combat the climate emergency."

Multiple efforts have been made over the years to tackle air pollution, such as the signing of C40 Clean Air Declaration by ten major African cities. Initiatives to monitor air-pollution levels and collect much needed data have also begun to gather momentum.

But there is still much to be done. The researchers argue that regional and international efforts must be coordinated to achieve real change and leverage existing knowledge on controlling and cutting air pollution.

They call for urgent collaboration on:

• Continuous air monitoring via a network of sensors in order to build a detailed picture of air pollution variations and track progress.
• Investment in clean energy such as solar, hydropower and wind to meet Africa's energy demand which is expected to double by 2040.
• Improved solid waste management to prevent dumping and burning of waste and improve reuse, recycling, and recovery rates.
• Investment in environmentally friendly technology to ensure African countries can grow economically whilst avoiding dirty and obsolete technology from the Global North.
• Infrastructure improvements to curb emissions from the transport sector, improving public transport provision and adopting higher emission standards for fuel and imported vehicles.

Co-author of the article, Dr Gabriel Okello, from the Institute for Sustainability Leadership at the University of Cambridge and the African Centre for Clean Air, said: "Air pollution is complex and multifaceted with different sources and patterns within society. Addressing it requires more ambitious, collaborative, and participatory approaches centred on involvement of stakeholders in policy, academia, business, communities to co-design and co-produce context-specific interventions. This should be catalysed by increased investment in interventions that are addressing air pollution. Africa has the opportunity to leverage the growing political will and tap into the young population to accelerate action towards the five broad suggestions in our paper."

Dr Andriannah Mbandi, from South Eastern Kenya University and co-author of the article, said: "The burden of air pollution unjustly rests on poorer populations, and women and children, as they most likely face higher exposure to pollutants and most probably experience more impacts. Thus, clean air actions will go some ways in redressing some of these inequalities in Africa, in addition to the benefits to health and the environment."

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Read more at Science Daily

Epigenetic changes are paramount in cancer progression

The path a cell takes from healthy to metastatic cancer is mostly driven by epigenetic changes, according to a new computational study. Dr. Eduard Porta, group leader of the Cancer Immunogenomics group at the Josep Carreras Leukaemia Research Institute, participated in the new analysis that has been recently published in the journal Nature.

Every cell makes its own proteins by accessing the genetic information on its genes. Changes in this information, called mutations, may ruin the function of the affected proteins. In oncology, this is regarded as the genetics of cancer. The last decades, however, have seen the rise of a new field: the epigenetics of cancer.

Epigenetic modifications do not change the information but transiently modifies the cell's ability to read some of its own genes and produce the associated proteins instead. There is a vast epigenetic programme controlling in such way the general working of the cell and, when altered, it may put it at the starting line of malignant transformation. Is there a way to track these changes and understand the epigenetics of cancer transition?

An international team of researchers has started to unlocked this long-awaited milestone. In a tour de force, they analysed 1.7 million cells from 225 samples from primary and metastatic origin, from 205 patients of 11 different cancer types. For each cell, the team obtained the full transcriptome, exome and epigenome. This covers virtually all gene mutations, gene accessibility and its consequences. Using vast computational power, they could deduce the whole functional status of each analysed cell and link it to its particular cancer type.

The results of the work, published in the scientific journal Nature, demonstrate that many regions in the DNA are differentially activated or inactivated in a cancer-specific manner, creating a signature for each tumour. These differences are relevant for cancer progression and many correspond to already identified hallmarks of cancer, the steps a cell must undergo to become malignant. Dr. Eduard Porta, group leader at the Josep Carreras Leukaemia Research Institute (IJC-CERCA), is part of the team and contributed with his experience in the analysis of large amounts of biological data.

Epigenetic changes at the DNA level stand out as an underlying cause of cancer, according to the new publication. Particularly, the accessibility of enhancer regions, a kind of master regulator acting upon many genes at once. Taken together, the results converges into a short list of genes that can be used as markers for good or poor prognosis, valuable information for the clinical management of patients.

Read more at Science Daily

Studies of geologic faulting on icy moons aid exploration of extraterrestrial watery worlds

On the surface of many of the icy moons in our solar system, scientists have documented strike-slip faults, those that occur when fault walls move past one another sideways, as is the case at the San Andreas fault in California. Two recently published studies led by University of Hawai'i at Manoa earth and space scientists document and reveal the mechanisms behind these geologic features on the largest moon of Saturn, Titan, and Jupiter's largest moon, Ganymede.

"We are interested in studying shear deformation on icy moons because that type of faulting can facilitate the exchange of surface and subsurface materials through shear heating processes, potentially creating environments conducive for the emergence of life," said Liliane Burkhard, lead author of the studies and research affiliate at the Hawai'i Institute of Geophysics and Planetology in the UH Manoa School of Ocean and Earth Science and Technology.

When an icy moon moves around its parent planet, the gravity of the planet can cause tidal flexing of the surface of the moon, which can drive geologic activity such as strike-slip faulting. Tidal stresses vary as the moon changes distance from its planet because the moon's orbit can be elliptical rather than circular.

Titan, a frozen ocean world

The extremely cold temperatures on the surface of Titan mean that water ice acts as rock that can crack, fault, and deform. Evidence from the Cassini spacecraft suggests that tens of miles below the frozen surface, there is a liquid water ocean. Further, Titan is the only moon in our solar system with a dense atmosphere, which, uniquely, supports an Earth-like hydrological cycle of methane clouds, rain, and liquid flowing across the surface to fill lakes and seas, placing it among a handful of worlds that could potentially contain habitable environments.

The NASA Dragonfly mission will launch in 2027, with a planned arrival on Titan in 2034. The novel rotorcraft lander will conduct several flights on the surface, exploring a variety of locations to search for the building blocks and signs of life.

In their investigation of the Selk crater area on Titan, the designated initial landing site for the Dragonfly mission, Burkhard and her co-author explored the potential for shear deformations and strike-slip faulting. To do this, they calculated the stress that would be exerted on Titan's surface due to tidal forces as the moon orbits Saturn and tested the possibility of faulting by examining various characteristics of the frozen ground.

"While our prior research indicated that certain areas on Titan might currently undergo deformation due to tidal stresses, the Selk crater area would need to host very high pore fluid pressures and a low crustal coefficient of friction for shear failure, which seems improbable," said Burkhard. "Consequently, it's safe to infer that Dragonfly won't be landing in a strike-slip ditch!"

Ganymede, a moon with a checkered past

In a second publication, Burkhard and her co-authors investigated the geologic history of Ganymede, Jupiter's largest moon, in the area of Nippur/Philus Sulci by examining high-resolution data available for this region and conducting a tidal stress investigation of Ganymede's past.

Ganymede has documented strike-slip faults on the surface, but its current orbit is too circular, as opposed to elliptical, to cause any tidal stress deformation.

The researchers found that several crosscutting bands of light terrain in the Nippur/Philus Sulci site show varying degrees of tectonic deformation, and the chronology of tectonic activity implied by mapped crosscutting relationships revealed three eras of distinct geologic activity: ancient, intermediate and youngest.

"I investigated strike-slip faulting features in intermediate-aged terrain, and they correspond in slip direction to the predictions from modeling stresses of a higher past eccentricity. Ganymede could have undergone a period where its orbit was much more elliptical than it is today," said Burkhard.

Other shear features found in younger geologic units in the same region do not align in slip direction with typical first-order shear indicators.

"This suggests that these features might have formed through another process and not necessarily due to higher tidal stresses," Burkhard added. "So, Ganymede has had a tidal 'mid-life crisis', but its youngest 'crisis' remains enigmatic."

The recent studies along with space exploration missions create a positive feedback of knowledge.

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Fossils tell tale of last primate to inhabit North America before humans

The story of Ekgmowechashala, the final primate to inhabit North America before Homo sapiens or Clovis people, reads like a spaghetti western: A grizzled and mysterious loner, against the odds, ekes out an existence on the American Plains.

Except this tale unfolded about 30 million years ago, just after the Eocene-Oligocene transition during which North America saw great cooling and drying, making the continent less hospitable to warmth-loving primates.

Today, paleontologists from the University of Kansas and the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing have published evidence in the Journal of Human Evolution shedding light on the long-standing saga of Ekgmowechashala, based on fossil teeth and jaws found in both Nebraska and China.

To do so, the researchers first had to reconstruct its family tree, a job helped by the discovery of an even more ancient Chinese "sister taxon" of Ekgmowechashala the team has named Palaeohodites (or "ancient wanderer"). The Chinese fossil discovery resolves the mystery of Ekgmowechashala's presence in North America, showing it was an immigrant rather than the product of local evolution.

"This project focuses on a very distinctive fossil primate known to paleontologists since the 1960s," said lead author Kathleen Rust, a doctoral candidate in paleontology at KU's Biodiversity Institute and Natural History Museum. "Due to its unique morphology and its representation only by dental remains, its place on the mammalian evolutionary tree has been a subject of contention and debate. There's been a prevailing consensus leaning towards its classification as a primate. But the timing and appearance of this primate in the North American fossil record are quite unusual. It appears suddenly in the fossil record of the Great Plains more than 4 million years after the extinction of all other North American primates, which occurred around 34 million years ago."

In the 1990s, Rust's doctoral adviser and co-author Chris Beard, KU Foundation Distinguished Professor and senior curator of vertebrate paleontology, collected fossils from the Nadu Formation in the Baise Basin in Guangxi, China, that closely resembled the Ekgmowechashala material known from North America. By that time, Ekgmowechashala was notoriously enigmatic among North American paleontologists.

"When we were working there, we had absolutely no idea that we would find an animal that was closely related to this bizarre primate from North America, but literally as soon as I picked up the jaw and saw it, I thought, 'Wow, this is it,'" Beard said. "It's not like it took a long time, and we had to undertake all kinds of detailed analysis -- we knew what it was. Here in KU's collection, we have some critical fossils, including what is still by far the best upper molar of Ekgmowechashala known from North America. That upper molar is so distinctive and looks quite similar to the one from China that we found that it kind of seals the deal."

Beard left it to Rust to conduct the morphological analysis that tied Ekgmowechashala and its cousin Palaeohodites from China in a phylogenetic tree to establish their evolutionary relationships.

In the course of the work, Rust was able to draw conclusions about how Ekgmowechashala came to be discovered in Nebraska, millions of years after its fellow primates died out in the continent's fossil record.

"We collected a substantial amount of morphological data to create an evolutionary tree using a phylogenetic reconstruction software and algorithm," Rust said. "This evolutionary tree suggests a close evolutionary relationship between North American Ekgmowechashala and Palaeohodites from China, which Chris and his colleagues discovered in the 1990s. The results from our analysis unequivocally supports this hypothesis."

The KU researchers said their discovery is not only exciting in terms of discovering a new primate species from late Eocene China -- but also in settling the origin story of Ekgmowechashala. Based on their investigation, Ekgmowechashala did not descend from an older North American primate that somehow survived the cooler and drier conditions that caused other North American primates to go extinct. Rather, its ancestors crossed over the Beringian region millions of years later, anticipating the route followed by the first Native Americans much later in time.

"Our analysis dispels the idea that Ekgmowechashala is a relic or survivor of earlier primates in North America," Rust said. "Instead, it was an immigrant species that evolved in Asia and migrated to North America during a surprisingly cool period, most likely via Beringia."

Species like Ekgmowechashala that show up suddenly in the fossil record long after their relatives have died off are referred to as "Lazarus taxa" after the biblical figure who was raised from the dead.

"The 'Lazarus effect' in paleontology is when we find evidence in the fossil record of animals apparently going extinct -- only to reappear after a long hiatus, seemingly out of nowhere," Beard said. "This is the grand pattern of evolution that we see in the fossil record of North American primates. The first primates came to North America about 56 million years ago at the beginning of the Eocene, and they flourished on this continent for more than 20 million years. But they went extinct when climate became cooler and drier near the Eocene-Oligocene boundary, about 34 million years ago. Several million years later Ekgmowechashala shows up like a drifting gunslinger in a Western movie, only to be a flash in the pan as far as the long trajectory of evolution is concerned. After Ekgmowechashala is gone for more than 25 million years, Clovis people come to North America, marking the third chapter of primates on this continent. Like Ekgmowechashala, humans in North America are a prime example of the Lazarus effect."

Rust and Beard were joined in the work by co-authors Xijun Ni of the Chinese Academy of Sciences, Beijing, and Kristen Tietjen, scientific illustrator with the KU Biodiversity Institute and Natural History Museum.

According to Rust, the tale of Ekgmowechashala is worth people's attention because it happened in an era of profound environmental and climatic changes, much like our own that's driven by human activity.

"It's crucial to comprehend how past biota reacted to such shifts," she said. "In such situations, organisms typically either adapt by retreating to more hospitable regions with available resources or face extinction. Around 34 million years ago, all of the primates in North America couldn't adapt and survive. North America lacked the necessary conditions for survival. This underscores the significance of accessible resources for our non-human primate relatives during times of drastic climatic change."

The study is also a part of a larger story that represents the earliest chapters of our own evolutionary journey that ultimately led to our own species, Rust said.

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Long-distance weaponry identified at the 31,000-year-old archaeological site of Maisières-Canal

The hunter-gatherers who settled on the banks of the Haine, a river in southern Belgium, 31,000 years ago were already using spearthrowers to hunt their game. This is the finding of a new study conducted at TraceoLab at the University of Liège. The material found at the archaeological site of Maisières-Canal permits establishing the use of this hunting technique 10,000 years earlier than the oldest currently known preserved spearthrowers. This discovery, published in the journal Nature Scientific Reports, is prompting archaeologists to reconsider the age of this important technological innovation.

The spearthrower is a weapon designed for throwing darts, which are large projectiles resembling arrows that generally measure over two metres long. Spearthrowers can propel darts over a distance of up to eighty metres. The invention of long-range hunting weapons has had significant consequences for human evolution, as it changed hunting practices and the dynamics between humans and their prey, as well as the diet and social organisation of prehistoric hunter-gatherer groups. The date of invention and spread of these weapons has therefore long been the subject of lively debate within the scientific community.

"Until now, the early weapons have been infamously hard to detect at archaeological sites because they were made of organic components that preserve rarely, explains Justin Coppe, researcher at TraceoLab. Stone points that armed ancient projectiles and that are much more frequently encountered at archaeological excavations have been difficult to connect to particular weapons reliably." Most recently published claims for early use of spearthrowers and bows in Europe and Africa have relied exclusively on projectile point size to link them to these weapon systems. However, ethnographic reviews and experimental testing have cast serious doubt on this line of reasoning by showing that arrow, dart, and spear tips can be highly variable in size, with overlapping ranges.

The innovative approach developed by the archaeologists at TraceoLab combines ballistic analysis and fracture mechanics to gain a better understanding of the traces preserved on the flint points. "We carried out a large-scale experiment in which we fired replicas of Palaeolithic projectiles using different weapons such as spears, bows and spearthrowers," explains Noora Taipale, FNRS research fellow at TraceoLab. By carefully examining the fractures on these stone points, we were able to understand how each weapon affected the fracturing of the points when they impacted the target." Each weapon left distinct marks on the stone points, enabling archaeologists to match these marks to archaeological finds. In a way, it's like identifying a gun from the marks the barrel leaves on a bullet, a practice known from forensic science.

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450-million-year-old organism finds new life in Softbotics

Researchers in the Department of Mechanical Engineering at Carnegie Mellon University, in collaboration with paleontologists from Spain and Poland, used fossil evidence to engineer a soft robotic replica of pleurocystitid, a marine organism that existed nearly 450 million years ago and is believed to be one of the first echinoderms capable of movement using a muscular stem.

Published today in The Proceedings of the National Academy of Science (PNAS), the research seeks to broaden modern perspective of animal design and movement by introducing a new a field of study -- Paleobionics -- aimed at using Softbotics, robotics with flexible electronics and soft materials, to understand the biomechanical factors that drove evolution using extinct organisms.

"Softbotics is another approach to inform science using soft materials to construct flexible robot limbs and appendages. Many fundamental principles of biology and nature can only fully be explained if we look back at the evolutionary timeline of how animals evolved. We are building robot analogues to study how locomotion has changed," said Carmel Majidi, lead author and Professor of Mechanical Engineering at Carnegie Mellon University.

With humans' time on earth representing only 0.007% of the planet's history, the modern-day animal kingdom that influences understanding of evolution and inspires today's mechanical systems is only a fraction of all creatures that have existed through history.

Using fossil evidence to guide their design and a combination of 3D printed elements and polymers to mimic the flexible columnar structure of the moving appendage, the team demonstrated that pleurocystitids were likely able to move over the sea bottom by means of a muscular stem that pushed the animal forward. Despite the absence of a current day analogue (echinoderms have since evolved to include modern day starfish and sea urchins), pleurocystitids have been of interest to paleontologists due to their pivotal role in echinoderm evolution.

The team determined that wide sweeping movements were likely the most effective motion and that increasing the length of the stem significantly increased the animals' speed without forcing it to exert more energy.

"Researchers in the bio-inspired robotics community need to pick and choose important features worth adopting from organisms," explained Richard Desatnik, PhD candidate and co-first author.

"Essentially, we have to decide on good locomotion strategies to get our robots moving. For example, would a starfish robot really need to use 5 limbs for locomotion or can we find a better strategy?" added Zach Patterson, CMU alumnus and co-first author.

Now that the team has demonstrated that they can use Softbotics to engineer extinct organisms, they hope to explore other animals, like the first organism that could travel from sea to land -- something that can't be studied in the same way using conventional robot hardware.

"Bringing a new life to something that existed nearly 500 million years ago is exciting in and of itself, but what really excites us about this breakthrough is how much we will be able to learn from it," said Phil LeDuc, co-author, and Professor of Mechanical Engineering at Carnegie Mellon University. "We aren't just looking at fossils in the ground, we are trying to better understand life through working with amazing paleontologists."

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Where is a sea star's head? Maybe just about everywhere

If you put a hat on a starfish, where would you put it? On the center of the starfish? Or on the point of an arm and, if so, which one? The question is silly, but it gets at serious questions in the fields of zoology and developmental biology that have perplexed veteran scientists and schoolchildren in introductory biology classes alike: Where is the head on a starfish? And how does their body layout relate to ours?

Now, a new Stanford study that used genetic and molecular tools to map out the body regions of starfish -- by creating a 3D atlas of their gene expression -- helps answer this longstanding mystery. The "head" of a starfish, the researchers found, is not in any one place. Instead, the headlike regions are distributed with some in the center of the sea star as well as in the center of each limb of its body.

"The answer is much more complicated than we expected," said Laurent Formery, lead author and postdoc in the labs of Christopher Lowe at the Stanford School of Humanities and Sciences and Daniel S. Rokhsar at the University of California, Berkeley. "It is just weird, and most likely the evolution of the group was even more complicated than this."

Starfish (sea stars) belong to a group of animals called echinoderms. Echinoderms and humans are closely related, yet the life cycle and anatomy of sea stars are very different from ours.

Sea stars begin life as fertilized eggs that hatch into a free-floating larva. The larvae bob in the ocean in a plankton form for weeks to months before settling to the ocean floor to perform a magic trick of sorts -- transforming from a bilateral (symmetric across the midline) body plan into an adult with a five-point star shape called a pentaradial body plan.

"This has been a zoological mystery for centuries," said Lowe, who is also a researcher at Hopkins Marine Station and senior author of the paper that published Nov. 1 in Nature. "How can you go from a bilateral body plan to a pentaradial plan, and how can you compare any part of the starfish to our own body plan?"

Mapping stars

For puzzles such as this one, researchers often conduct comparative studies to identify similar structures in related groups of animals to glean clues about the evolutionary events that prompted the trait of interest.

"The problem with starfish is there is nothing on a starfish anatomically that you can relate to a vertebrate," said Lowe. "There is just nothing there."

At least, nothing on the outside of a starfish. And that is where genetic and molecular techniques come in.

During his graduate research, Formery studied early development in sea urchins -- echinoderms, like sea stars, that also start their life as bilateral larvae before transforming into adults with fivefold symmetry. When Formery joined Lowe's lab, Formery's knowledge of echinoderm development combined with Lowe's expertise in molecular biology techniques to help tackle the mystery of sea stars' baffling body plan.

The team used a group of well-studied molecular markers (Hox genes are an example) that act as blueprints for an organism's body plan by "telling" each cell which body region it belongs to.

"If you strip away the skin of an animal and look at the genes involved in defining a head from a tail, the same genes code for these body regions across all groups of animals," said Lowe. "So we ignored the anatomy and asked: Is there a molecular axis hidden under all this weird anatomy and what is its role in a starfish forming a pentaradial body plan?"

To investigate this question, the researchers used RNA tomography, a technique that pinpoints where genes are expressed in tissue, and in situ hybridization, a technique that zeroes in on a specific RNA sequence in a cell.

"First we sectioned sea star arms into thin slices from tip to center, top to bottom, and left to right," said Formery, noting that sea stars regenerate missing limbs. "We used RNA tomography to determine which genes were expressed in each slice and then 'reassembled' the slices using computer models. This gave us a 3D map of gene expression."

"In the second method, in situ hybridization chain reaction, we stained sea star tissue and visually inspected the samples to see where a gene was expressed," said Formery. This enabled the researchers to examine anterior-posterior (head to tail) body patterning in the outermost layer of cells called the ectoderm.

"This was made possible by the recent, big, technical improvement in in situ hybridization, known as in situ hybridization chain reaction, Formery said. "This new method provides better resolution of where the gene is expressed."

The research revealed that sea stars have a headlike territory in the center of each "arm" and a tail-like region along the perimeter. In an unexpected twist, no part of the sea star ectoderm expresses a "trunk" genetic patterning program, suggesting that sea stars are mostly headlike.

Mining truly diverse biodiversity

Research is often centered on groups of animals that look like us, the researchers explained. But if we focus on the familiar, we are less likely to learn something new.

"There are 34 different animal phyla living on this planet and in over roughly 600 million years they have all come up with different solutions to the same fundamental biological problems," Lowe said. "Most animals don't have spectacular nervous systems and are out chasing prey -- they are modest animals that live in burrows in the ocean. People are generally not drawn to these animals, and yet they probably represent how much of life got started."

This study demonstrates how a comparative approach that uses genetic and molecular techniques can be used to mine biodiversity for insights into why different animals look the way they do and how their body plans evolved.

"Even in recent molecular papers there's a question mark near echinoderms on the evolutionary tree because we don't know much about them," Formery said. "It was nice to show that -- at least at the molecular level -- we have a new piece of the puzzle that can now be put on the tree."

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Predicting saltwater intrusion into groundwater using Plymouth, Mass. as test case

As the world warms and ice sheets melt, the ocean continually rises. The greater Boston area can expect to see between one and six feet of sea level rise by 2100, according to recent estimates. To find out what this rise might mean for freshwater supplies, a team of hydrogeologists from the University of Massachusetts Amherst, led by David Boutt, professor of Earth, geographic and climate sciences, partnered with the Southeastern Massachusetts Pine Barrens Alliance (SEMPBA) and 13 other grassroots environmental organizations to develop an innovative new model that can not only predict saltwater intrusion over the next 75 years, but also pinpoint the main sources of salt contamination today -- road salt and human development. The team released the results of their study in the recent report, Saltwater Intrusion Vulnerability Assessment in Plymouth, MA.

"For many years now, I've been working with citizen stakeholders in the southeastern corner of Massachusetts," says Boutt, "and in 2021, the Pine Barrens Alliance, an environmental group interested in preserving the area's unique environmental character, approached me with an idea for a project to help assess how communities along the coast could best prepare for climate change."

Boutt and his colleagues, including recent UMass graduate and research assistant Alexander Kirshen, undergraduates Rachel King and Carly Lombardo, graduate student Daniel Corkran and postdoctoral researcher Brendan Moran, jumped at the opportunity to apply their academic research to an urgent, real-world problem close to home.

Plymouth sits on top of a freshwater aquifer -- the town's sole source of water. Because Plymouth extends to the ocean's edge, it is extremely susceptible to rising sea levels. For their study, Boutt, Kirshen and colleagues peeked underground to see what was happening.

Groundwater, flowing beneath the surface of the land, and the ocean's water, which, likewise, flows subterraneanly, push against each other and reach an equilibrium state. A well sunk on the freshwater side will flow with sweet water, but one that drills down into the brackish meeting point between fresh and salt will come up briny. As the oceans rise, that sub-surface saltwater pushes farther inland, and wells that have delivered pure water for generations can suddenly turn salty.

While the theory might seem intuitive enough, actually mapping, to say nothing of predicting, the flows and interactions of both fresh and salt water is an enormously complex task.

To start, the team built a salinity database that gathered all the available data from groundwater wells and surface water, such as ponds and streams, in the Plymouth area and measured them for salinity. This gave them a baseline understanding of the current locations and likely sources of elevated water salinity.

Next, Boutt and Kirshen adopted an existing U.S. Geological Survey hydrogeological model, which only focused on the onshore half of the hydrogeology equation, by extending its reach five kilometers offshore. The model includes ponds, streams, terrestrial recharge -- or the rate and amount of precipitation that seeps down into the aquifer -- as well the various wells that draw from the aquifer and the wastewater that is returned to the aquifer via re-infiltration or septic systems.

Finally, they conducted a series of model runs that took into consideration various scenarios in terms of future precipitation, sea-level rise, groundwater usage and changes in water returned to the aquifer.

"We found that, under the high sea-level rise scenario, areas of the aquifer will increase in salinity by up to 17,000 milligrams per liter by 2100," says Kirshen, "and the mixing zone between the ocean and freshwater will migrate inland by up to 200 meters." While a few ponds might see significant rise in water elevation, by up to 1.8 meters, most ponds would not see their salinity increase from this source of salinization.

The team also learned that water returned to the aquifer by septic systems plays a major role in helping to limit saltwater intrusion. "About 66% of the water that gets pumped out of the aquifer ends up returning to it," says Kirshen.

Perhaps the biggest surprise is that the highest levels of salinity today aren't near the coast, but inland, and especially around the roads. "This surprised me," says Boutt, "and it looks like road salt is one of the main sources of elevated salinity today."

"In partnering with UMass Amherst, we were always thinking beyond the municipal boundaries of Plymouth," says SEMPBA Vice President Frank Mand. "We share an aquifer and a geological foundation with over 30 communities in our ecoregion. So, though the news for Plymouth is good, more importantly we now have a scientific foundation -- and new methods for evaluating susceptibility to saltwater intrusion -- that are transferrable to those other communities and will help inform Plymouth's and other communities' planning for years to come."

"We were not looking to science to help us recover from our mistakes," Mand adds. "We were seeking to avoid problems in the future. That, in and of itself, was a worthy goal."

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