Loon stratospheric balloons confirm wind data from Aeolus

ESA's novel Aeolus satellite reliably measures wind speed also in higher air layers and thus in a region of the atmosphere where other direct global wind measurements are relatively sparse. This is the result of a study for which data from the satellite were compared with wind observations from stratospheric balloons. Stratospheric balloons would provide highly accurate data on the horizontal wind speed and are therefore also suitable for the validation of future satellite missions. Future wind satellites should increase the vertical resolution to better resolve gravity waves in the tropics, writes the team of researchers from the Leibniz Institute for Tropospheric Research (TROPOS), the European Space Agency (ESA), the European Centre for Medium-Range Weather Forecasts (ECMWF), the University of Hamburg and the Google company Loon. The study has now been published in the Quarterly Journal of the Royal Meteorological Society.

The quality of numerical weather prediction models and thus of weather forecasts depends heavily on the available data. In recent decades, a global observation system has therefore been built up which also includes wind profiles from weather balloons, aircraft data or wind profiler radar systems. However, most of this data comes from the densely populated northern hemisphere. In the southern hemisphere, over the oceans and especially in the tropics, the network of direct measurements is still relatively sparse.

The launch of the European Space Agency's (ESA) first wind satellite Aeolus on 22 August 2018 was therefore a major step towards global wind measurements. This novel satellite has a powerful laser on board, the Atmospheric Laser Doppler Instrument (ALADIN). ALADIN is the first Doppler wind lidar in space to provide profiles of horizontal wind speed from the Earth's surface or from the top of thick clouds up to a height of about 30 km on a global scale. To do this, the satellite emits short ultraviolet laser pulses as it orbits the Earth. A small part of these light pulses is scattered back to the satellite by air molecules, aerosols and clouds and collected and processed in the detector there. For one circumnavigation of the globe Aeolus takes 90 minutes, within a week the satellite collects wind data around the entire globe. This data is assimilated by weather forecasting centres around the world to improve their forecasts. Since there have been no comparable satellite missions so far, the data are checked particularly critically and compared with other wind measurements.

A study recently published used data from 229 stratospheric balloons of the Loon project between July 2019 and December 2020 from tropical Latin America, Atlantic Ocean, Africa and Indian Ocean for comparison. Loon was a commercial project that had provided remote regions with internet access via helium balloons in the stratosphere. The balloons, which were about 12 metres in diameter, acted as floating mobile phone stations at altitudes of 16 to 20 kilometres above the ground. For maintaining the network, the balloons had to automatically correct the wind direction by changing the altitude. This created an extensive data set on wind speeds in these atmospheric layers, which partially fills the gap in wind data at this altitude in the global observation system. The Loon project was discontinued in 2021 for economic reasons, but a highly interesting data set remains for atmospheric research.

"Our analysis confirms that the Aeolus satellite provides almost bias-free wind measurements in the upper troposphere and lower stratosphere. In contrast, the current ECWMF weather model systematically underestimates the wind speed there by about 1 metre per second, which could be demonstrated by the Aeolus and Loon data. These results are important to better understand dynamical processes in the upper troposphere and lower stratosphere and to further improve the weather models," emphasises Dr. Sebastian Bley from TROPOS, who worked for the study at ESA in Frascati, Italy. Another recommendation of the researchers is to carry out more vertical measurements to be able to provide more wind information in the atmospheric layers. This could further improve the accuracy of upcoming wind satellites. In addition to wind speed, Aeolus also provides information about aerosols and clouds, but only via a portion of the backscattered light. "We hope that future wind missions will also be able to measure depolarisation, the rotation of light when it is reflected. That would be a milestone because the satellite could then also provide more information about aerosols," explains Bley.

Aeolus was developed as an explorer mission with an expected lifetime of 3 years to demonstrate the technology of a Doppler wind lidar in space. However, expectations have been exceeded and Aeolus has now been providing valuable data for over 4 years. The wind data are now used in the weather forecasts of several weather services throughout Europe, such as the German Weather Service (DWD), and have been convincing due to their positive influence on the quality of weather forecasts. The way forward for the follow-on mission Aeolus-2 has been recently decided in the ESA ministerial and will be jointly developed by ESA and EUMETSAT.

In September, researchers from the USA had integrated Aeolus data into the hurricane model (HWRF) of the US weather and oceanography agency NOAA on a trial basis in order to better predict tropical storms. Their conclusion is that the use of Aeolus wind data is most effective where there are no reconnaissance flights into the hurricanes and could therefore have the greatest positive impact on tropical cyclone forecasting in the Pacific and Indian Oceans.

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Palau's Rock Islands harbor heat-resistant corals

Ocean warming is driving an increase in the frequency and severity of marine heatwaves, causing untold damage to coral reefs. Tropical corals, which live in symbiosis with tiny single celled algae, are sensitive to high temperatures, and exhibit a stress response called bleaching when the ocean gets too hot. In the last 4 decades, marine heatwaves have caused widespread bleaching, and killed millions of corals. Because of this, a global search is underway for reefs that can withstand the heat stress, survive future warming, and act as sources of heat-tolerant coral larvae to replenish affected areas both naturally and through restoration.

Now, scientists studying reefs in Palau, an archipelago in the western tropical Pacific, have identified genetic subgroups of a common coral species that exhibit remarkable tolerance to the extreme heat associated with marine heatwaves. Further, the scientists found evidence that larvae from these corals are traveling from their birthing grounds deep in Palau's lagoons, to the outer reef, where they survive and grow, and maintain their heat tolerance.

Understanding both the underlying mechanisms that facilitate heat tolerance of these corals, as well as the dispersal capabilities of their larvae will go a long way toward enhancing coral reef conservation and restoration efforts in the 21st century ocean, according to scientists at the Woods Hole Oceanographic Institution (WHOI) who led the research.

In Palau's main lagoon, a network of very ancient, fossilized reefs has been uplifted to form a series of mountains known as the Rock Islands. These formations slow water flow in and around them, creating localized environments in which the water temperatures are consistently higher than other areas of Palau's reefs.

Scientists sampled the keystone coral species Porites lobata (lobe coral) across Palau, including the Rock Islands. They took skeletal biopsies and examined the cores for stress bands, which are telltale signs of bleaching, a stress response corals have to high temperatures. They found corals from the Rock Islands bleached less during the intense 1998 heatwave than corals from other areas of the reef, indicating enhanced thermal tolerance.

Scientists then investigated the genetics of the corals and discovered four distinct lineages within the same species. Within the warmer Rock Islands, certain lineages, designated as "LB" and "RD" lineages, were much more common. The scientists were able to match the genetics of each coral with its own bleaching history and found that fewer individuals from the "LB" and "RD" lineages bleached during 1998, indicating enhanced thermal tolerance.

Remarkably, the scientists found the LB lineage was not restricted to the Rock Islands. They found some LB colonies also living on the cooler outer reefs. An examination of the bleaching histories of these colonies again revealed fewer stress bands, indicating that they maintained the thermal tolerance characteristic of their relatives in the Rock Islands.

"This suggests that the Rock Islands provide naturally tolerant larvae to neighboring areas," the scientists write in the paper titled "Palau's warmest reefs harbor thermally tolerant corals that thrive across different habitats," published in Communications Biology, a journal published by Nature. "Finding and protecting such sources of thermally-tolerant corals is key to reef survival under 21st century climate change."

"As oceans worldwide continue to warm, corals derived from extreme habitats will be at a competitive advantage and may enable the survival of otherwise vulnerable reefs," the authors continue. "Identifying and safeguarding natural breeding grounds of environmentally tolerant corals that can thrive under future climate conditions will be fundamental to the persistence of coral reef ecosystems worldwide in the coming decades."

"We found that some of Palau's reefs with the highest temperatures have corals that are more tolerant than one would expect," said the paper's lead author Hanny Rivera, a graduate of the MIT-WHOI Joint Program. Rivera, who conducted this work as part of her Ph.D. and postdoctoral research, is currently an associate director of business development at Ginko Bioworks. "In addition, they are genetically distinct from the same corals found in other parts of Palau, which suggests that there has been natural selection for hardier corals in these regions.."

Paper co-author Michael Fox added that the study is particularly exciting because it combines coral genetics with historical records of bleaching preserved in their skeletons to shed light on how corals from extreme habitats with high temperature tolerance can be dispersed across a reefscape. "This integrated perspective is essential for improving projections of coral communities in a warming ocean," said Fox, who was a postdoctoral scholar at WHOI during the research for this paper. He currently is an assistant research professor in the Red Sea Research Center at King Abdullah University of Science and Technology in Thuwal, Saudi Arabia.

The Palau research is directly related to the Super Reefs initiative WHOI launched with The Nature Conservancy and Stanford University to locate coral communities that can withstand marine heat waves, and work with local communities and governments to protect them.

"This work is the scientific basis for the Super Reefs initiative," said paper co-author Anne Cohen, a scientist at WHOI and Rivera's advisor on the study. "The Palau research demonstrates that Super Reefs exist and also provides actionable science knowledge that can be used to support their protection."

Cohen noted that there are other coral reefs, not just in Palau, where coral communities have not bleached as severely as scientists predicted based on the levels of thermal stress. "When we find the coral communities that are heat-tolerant or bleaching-resistant, and we protect them from other stresses that can kill them -- like dynamiting, overfishing, or coastal development -- they will produce millions of larvae that will travel on the currents, outside of their places of origin as we see on Palau, and they will repopulate reefs that have been devastated by heatwaves," she said. "Nature is amazing. Our job with the Super Reefs initiative is to protect these thermally resilient reefs and let nature do the rest."

Rivera added she is in awe of the immense appreciation, respect, and stewardship that the Palauan people have for their environment.

"They have been one of the pioneering countries in promoting marine conservation and ecological protection. It is wonderful to know that these special reefs are in such good hands," Rivera said. "It is my greatest hope that our research will further support the Palauan people in their efforts to maintain a healthy marine ecosystem."

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Men may not 'perceive' domestic tasks as needing doing in the same way as women, philosophers argue

Philosophers seeking to answer questions around inequality in household labour and the invisibility of women's work in the home have proposed a new theory -- that men and women are trained by society to see different possibilities for action in the same domestic environment.

They say a view called "affordance theory" -- that we experience objects and situations as having actions implicitly attached -- underwrites the age-old gender disparity when it comes to the myriad mundane tasks of daily home maintenance.

For example, women may look at a surface and see an implied action -- 'to be wiped' -- whereas men may just observe a crumb-covered countertop.

The philosophers believe these deep-seated gender divides in domestic perception can be altered through societal interventions such as extended paternal leave, which will encourage men to build up mental associations for household tasks.

Writing in the journal Philosophy and Phenomenological Research, they argue that available data -- particularly data gathered during the pandemic -- suggest two questions require explanation.

One is "disparity": despite economic and cultural gains, why do women continue to shoulder the vast majority of housework and childcare? The other is "invisibility": why do so many men believe domestic work to be more equally distributed than in fact it is?

"Many point to the performance of traditional gender roles, along with various economic factors such as women taking flexible work for childcare reasons," said Dr Tom McClelland, from Cambridge University's Department of History and Philosophy of Science.

"Yet the fact that stark inequalities in domestic tasks persisted during the pandemic, when most couples were trapped inside, and that many men continued to be oblivious of this imbalance, means this is not the full story."

McClelland and co-author Prof Paulina Sliwa argue that unequal divisions of labour in the home -- and the inability of men to identify said labour -- is best explained through the psychological notion of "affordances": the idea that we perceive things as inviting or "affording" particular actions.

"This is not just looking at the shape and size of a tree and then surmising you can climb it, but actually seeing a particular tree as climbable, or seeing a cup as drink-from-able," said Sliwa, recently of Cambridge's philosophy faculty and now at the University of Vienna.

"Neuroscience has shown that perceiving an affordance can trigger neural processes preparing you for physical action. This can range from a slight urge to overwhelming compulsion, but it often takes mental effort not to act on an affordance."

There are dramatic differences in "affordance perception" between individuals. One person sees a tree as climbable where another does not. Objects offer a vast array of affordances -- one could see a spatula as an egg-frying tool or a rhythmic instrument -- and a spectrum of sensitivity towards them.

"If we apply affordance perception to the domestic environment and assume it is gendered, it goes a long way to answering both questions of disparity and invisibility," said McClelland.

According to the philosophers, when a woman enters a kitchen she is more likely to perceive the "affordances" for particular domestic tasks -- she sees the dishes as 'to be washed' or a fridge as 'to be stocked'.

A man may simply observe dishes in a sink, or a half-empty fridge, but without perceiving the affordance or experiencing the corresponding mental "tug." Over time, these little differences add up to significant disparities in who does what.

"Affordances pull on your attention," said Sliwa. "Tasks may irritate the perceiver until done, or distract them from other plans. If resisted, it can create a felt tension."

"This puts women in a catch-22 situation: either inequality of labour or inequality of cognitive load."

This gender-based split in affordance perception could have a number of root causes, say philosophers. Social cues encourage actions in certain environments, often given by adults when we are very young children. Our visual systems update based on what we encounter most frequently.

"Social norms shape the affordances we perceive, so it would be surprising if gender norms do not do the same," said McClelland.

"Some skills are explicitly gendered, such cleaning or grooming, and girls are expected to do more domestic chores than boys. This trains their ways of seeing the domestic environment, to see a counter as 'to be wiped'."

The "gendered affordance perception hypothesis" is not about absolving men say Sliwa and McClelland. Despite a deficit in affordance perception in the home, a man can easily notice what needs doing by thinking rather than seeing. Nor should sensitivity to domestic affordances in women be equated with natural affinity for housework.

"We can change how we perceive the world through continued conscious effort and habit cultivation," said McClelland. "Men should be encouraged to resist gendered norms by improving their sensitivity to domestic task affordances.

"A man might adopt a resolution to sweep for crumbs every time he waits for the kettle to boil, for example. Not only would this help them to do the tasks they don't see, it would gradually retrain their perception so they start to see the affordance in the future."

Collective efforts to change social norms require policy-level interventions, argue the philosophers. For example, shared parental leave gives fathers the opportunity to become more sensitive to caring-task affordances.

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Shedding light on the origin of complex life forms

How did the complex organisms on Earth arise? This is one of the big open questions in biology. A collaboration between the working groups of Christa Schleper at the University of Vienna and Martin Pilhofer at ETH Zurich has come a step closer to the answer. The researchers succeeded in cultivating a special archaeon and characterizing it more precisely using microscopic methods. This member of the Asgard archaea exhibits unique cellular characteristics and may represent an evolutionary "missing link" to more complex life forms such as animals and plants. The study was recently published in the journal Nature.

All life forms on earth are divided into three major domains: eukaryotes, bacteria and archaea. Eukaryotes include the groups of animals, plants and fungi. Their cells are usually much larger and, at first glance, more complex than the cells of bacteria and archaea. The genetic material of eukaryotes, for example, is packaged in a cell nucleus and the cells also have a large number of other compartments. Cell shape and transport within the eukaryotic cell are also based on an extensive cytoskeleton. But how did the evolutionary leap to such complex eukaryotic cells come about?

Most current models assume that archaea and bacteria played a central role in the evolution of eukaryotes. A eukaryotic primordial cell is believed to have evolved from a close symbiosis between archaea and bacteria about two billion years ago. In 2015, genomic studies of deep-sea environmental samples discovered the group of the so-called "Asgard archaea," which in the tree of life represent the closest relatives of eukaryotes. The first images of Asgard cells were published in 2020 from enrichment cultures by a Japanese group.

Asgard archaea cultivated from marine sediments

Christa Schleper's working group at the University of Vienna has now succeeded for the first time in cultivating a representative of this group in higher concentrations. It comes from marine sediments on the coast of Piran, Slovenia, but is also an inhabitant of Vienna, for example in the bank sediments of the Danube. Because of its growth to high cell densities, this representative can be studied particularly well. "It was very tricky and laborious to obtain this extremely sensitive organism in a stable culture in the laboratory," reports Thiago Rodrigues-Oliveira, postdoc in the Archaea working group at the University of Vienna and one of the first authors of the study.

Asgard archaea have a complex cell shape with an extensive cytoskeleton

The remarkable success of the Viennese group to cultivate a highly enriched Asgard representative finally allowed a more detailed examination of the cells by microscopy. The ETH researchers in Martin Pilhofer's group used a modern cryo-electron microscope to take pictures of shock-frozen cells. "This method enables a three-dimensional insight into the internal cellular structures," explains Pilhofer. "The cells consist of round cell bodies with thin, sometimes very long cell extensions. These tentacle-like structures sometimes even seem to connect different cell bodies with each other," says Florian Wollweber, who spent months tracking down the cells under the microscope. The cells also contain an extensive network of actin filaments thought to be unique to eukaryotic cells. This suggests that extensive cytoskeletal structures arose in archaea before the appearance of the first eukaryotes and fuels evolutionary theories around this important and spectacular event in the history of life.

Future insights through the new model organism

"Our new organism, called Lokiarchaeum ossiferum, has great potential to provide further groundbreaking insights into the early evolution of eukaryotes," comments microbiologist Christa Schleper. "It has taken six long years to obtain a stable and highly enriched culture, but now we can use this experience to perform many biochemical studies and to cultivate other Asgard archaea as well." In addition, the scientists can now use the new imaging methods developed at ETH to investigate, for example, the close interactions between Asgard archaea and their bacterial partners. Basic cell biological processes such as cell division can also be studied in the future in order to shed light on the evolutionary origin of these mechanisms in eukaryotes.

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ESPRESSO and CARMENES discover two potentially habitable exo-Earths around a star near the sun

An international scientific team led by researchers at the Instituto de Astrofísica de Canarias (IAC) has discovered the presence of two planets with Earth-like masses in orbit around the star GJ 1002, a red dwarf not far from the Solar System. Both planets are in the habitability zone of the star.

"Nature seems bent on showing us that Earth-like planets are very common. With these two we now know 7 in planetary systems quite near to the Sun," explains Alejandro Suárez Mascareño, an IAC researcher, who is the first author of the study accepted for publication in Astronomy & Astrophysics.

The newly discovered planets orbit the star GJ 1002, which is at a distance of less than 16 light years from the Solar System. Both of them have masses similar to that of the Earth, and they are in the habitability zone of their star. GJ 1002b, the inner of the two, takes little more than 10 days to complete an orbit around the star, while GJ 1002c needs a little over 21 days. "GJ 1002 is a red dwarf star, with barely one eighth the mass of the Sun. It is quite a cool, faint star. This means that its habitability zone is very close to the star," explains Vera María Passegger, a co-author of the article and an IAC researcher.

The proximity of the star to our Solar System implies that the two planets, especially GJ 1002c, are excellent candidates for the characterization of their atmospheres based either on their reflected light, or on their thermal emission. "The future ANDES spectrograph for the ELT telescope at ESO in which the IAC is participating, could study the presence of oxygen in the atmosphere of GJ 1002c," notes Jonay I. González Hernández, an IAC researcher who is a co-author of the article. In addition, both planets satisfy the characteristics needed for them to be objectives for the future LIFE mission, which is presently in a study phase.

The discovery was made during a collaboration between the consortia of the two instruments ESPRESSO and CARMENES. GJ 1002 was observed by CARMENES between 2017 and 2019, and by ESPRESSO between 2019 and 2021. "Because of its low temperature the visible light from GJ 1002 is too faint to measure its variations in velocity with the majority of spectrographs," says Ignasi Ribas, researcher at the Institute of Space Sciences (ICE-CSIC) and director of the Institut d'Estudis Espacials de Catalunya (IEEC). CARMENES has a sensitivity over a wide range of near infrared wavelengths which is superior to those of other spectrographs aimed at detecting variations in the velocities of stars, and this allowed it to study GJ 1002, from the 3.5m telescope at Calar Alto observatory.

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New cause of melting Antarctic ice shelves

Researchers have discovered a process that can contribute to the melting of ice shelves in the Antarctic.

An international team of scientists found that adjacent ice shelves play a role in causing instability in others downstream.

The study, led by the University of East Anglia in the UK, also identified that a small ocean gyre -- a system of circulating ocean currents -- next to the Thwaites Ice Shelf can impact the amount of glacial-meltwater flowing beneath it. When that gyre is weaker, more warm water can access the areas beneath the ice shelf, causing it to melt.

The Thwaites Ice Shelf is one of the biggest ice shelves in West Antarctica and buttresses the eastern side of the Thwaites Glacier, which has been retreating rapidly over the last 20 years and is the largest contributor to global sea-level rise among Antarctic glaciers.

Using a unique dataset collected by sensors installed beneath the Thwaites Ice Shelf -- which has also thinned and weakened significantly in recent decades -- the researchers observed that the shallow layers of the ocean underneath it warmed considerably during the period from January 2020 to March 2021.

Most of this warming was driven by waters with a high volume of glacial meltwater originating from the Pine Island Ice Shelf, further east, flowing into the area beneath the Thwaites Ice Shelf.

The glacial meltwater mixes with saltwater when the ocean melts the base of ice shelves and can form a buoyant layer of water that is warmer than the surrounding waters. This lighter, relatively fresher and warmer water brings heat that melts the base of the Thwaites Ice Shelf.

Lead author Dr Tiago Dotto, of the Centre for Ocean and Atmospheric Sciences at UEA, said: "We have identified another process that could impact the stability of ice shelves, revealing the importance of local ocean circulation and sea-ice.

"Circumpolar Deep Water, a warm variety of Antarctic waters, is a key player in melting the base of ice shelves. However, in this study, we show that a great amount of heat at shallow layers beneath one ice shelf can be provided by waters originating from other melting ice shelves nearby.

"Therefore, what happens to one ice shelf, can impact the adjacent ice shelf, and so on.

This process is important for regions of high ice shelf melting such as the Amundsen Sea because one ice shelf sits next to the other, and the export of heat from one ice shelf can reach the next one through the ocean circulation."

Dr Dotto added: "These atmosphere-sea-ice-ocean interactions are important because they can prolong warm periods beneath ice shelves by allowing warm and meltwater-enriched water to enter adjacent ice-shelf cavities.

"Gyres potentially existing in other regions around Antarctica may also cause a greater number of ice shelves to be prone to intense basal melting associated with prolonged warm conditions, and as a result further contribute to global sea-level rise."

In January 2020 colleagues from the US drilled holes in the ice and installed sensors monitoring temperature, salinity and ocean current beneath the Thwaites Ice Shelf.

For more than a year these sensors sent, via satellite, the data used to identify the ocean variations, for example how the temperature and meltwater content varied. From these observations, the researchers suspected that the excess of heat could not have originated locally at the Thwaites Ice Shelf because they did not see strong melting at the sites where the sensors were installed.

By combining the information with computer simulations to identify the origin of this heat, they found that the water that leaves the Pine Island Ice Shelf can access the areas beneath Thwaites Ice Shelf.

The mechanism that explains how these waters access the Thwaites Ice Shelf was identified by using model simulations and data collected by tags attached to seals. They both showed that a gyre near the Thwaites Ice Shelf weakens in winter, which allows more heat to reach shallow areas beneath the ice shelf.

Satellite images also showed that the Southern Hemisphere summer season of 2020/2021 was unusual because it had a high concentration of sea ice in regions near the Thwaites Ice Shelf.

Drawing on the simulations and previous research, the team hypothesised that the gyre was even weaker, so the excess of meltwater from adjacent ice shelves could not be moved away from that region by the currents and instead entered the Thwaites Ice Shelf.

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Climate impacts are increasing; textbooks aren't keeping pace

A new study from North Carolina State University finds that biology textbooks have done a poor job of incorporating material related to climate change. For example, the study found that most textbooks published in the 2010s included less information about climate change than they did in the previous decade -- despite significant advances in our understanding of how climate change is influencing ecosystems and the environment.

"In short, we found biology textbooks are failing to share adequate information about climate change, which is a generation-defining topic in the life sciences," says Jennifer Landin, corresponding author of the study and an associate professor of biological sciences at NC State. "These books are the baseline texts for helping students understand the science of life on Earth, yet they are providing very little information about a phenomenon that is having a profound impact on habitats, ecosystems, agriculture -- almost every aspect of life on Earth."

For the study, researchers analyzed coverage of climate change in 57 college biology textbooks published between 1970 and 2019. The researchers found that climate coverage has varied substantially over those five decades.

Prior to 1990, textbooks had a median of fewer than 10 sentences addressing climate change. In the 1990s, the median length of climate content was 30 sentences. The median length of climate content rose to 52 sentences in the 2000s, which is not surprising given the amount of emerging research into climate change and its impacts. However, the researchers found that the amount of climate coverage in textbooks actually declined in the 2010s -- dropping to a median of 45 sentences.

In addition to length, the nature of the content has also changed substantially over time. For example, sentences dedicated to actionable solutions to climate change peaked in the 1990s at more than 15% of the climate content. However, in more recent decades, actionable solutions make up only about 3% of the climate content.

"One of the most troubling findings was that textbooks are devoting substantially less space to addressing climate solutions now than they did in the 1990s -- even as they focus more on the effects of climate change," Landin says. "That suggests to students that nothing can be done, which is both wildly misleading and contributes to a sense of fatalism regarding climate change."

In addition, the position of climate change sections keeps moving further back in the books, from the last 15% of the overall text in the 1970s to the last 2.5% of the text in the 2010s.

"This is important because most instructors present textbook content in order, which means topics at the end of the book are often skipped," Landin says.

"However, it's not all bad news," Landin adds. "Textbooks in the 2000s and 2010s began including a wider variety of climate-relevant information, such as how climate is affecting species distributions, which can help students understand the various impacts of climate change.

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Heart health tip for older adults in 2023: Step it up a bit

The evidence-based health benefits of walking continue to accumulate, according to ongoing research by a University of Massachusetts Amherst physical activity epidemiologist, who leads an international consortium known as the Steps for Health Collaborative.

Findings from the latest study led by Amanda Paluch, assistant professor of kinesiology in the School of Public Health and Health Sciences, show that older adults who walked between 6,000 and 9,000 steps per day had a 40-50% reduced risk of a cardiovascular event, such as a heart attack or stroke, compared to those who walked 2,000 steps per day.

"We found for adults over 60, there was a strikingly lower risk of a cardiovascular event or disease over an average follow-up of six years," says Paluch, whose team's research was published this week in the journal Circulation. "When accumulating more steps per day, there was a progressively lower risk."

Earlier this year, research by Paluch and the Steps for Health Collaborative showed that more movement, even below the highly touted but unscientific "10,000 steps per day," was associated with longevity benefits. The meta-analysis of 15 studies involving nearly 50,000 people from four continents found that walking between 6,000 and 8,000 steps per day was linked with a lower risk of death from all causes among older adults.

Following those findings, Paluch and team wanted to tackle the less-charted territory of steps per day and cardiovascular disease. The results were similar, in terms of the most beneficial range of steps.

While there appears to be a continual additional benefit for those who walk more than 6,000 steps, Paluch says, encouraging the least-active older adults to take more steps is perhaps the most important public health message.

"The people who are the least active have the most to gain," she says. "For those who are at 2,000 or 3,000 steps a day, doing a little bit more can mean a lot for their heart health. If you're at 6,000 steps, getting to 7,000 and then to 8,000 also is beneficial, it's just a smaller, incremental improvement."

The meta-analysis of eight studies involved more than 20,000 people from the U.S. and 42 other countries. For younger adults, no link between steps per day and cardiovascular risk was detected.

"This is because cardiovascular disease is a disease of aging and often doesn't come to fruition until we're at older ages," says Paluch, whose project was supported by the Centers for Disease Control and Prevention (CDC). "You're not going to see many people develop cardiovascular disease after six years of follow-up in young to middle adulthood."

Future research involving younger adults and steps per day would focus on the precursors of cardiovascular disease, including high blood pressure, obesity and type 2 diabetes. "Those conditions develop in younger adults and are important for early prevention," Paluch says.

Four of the eight studies the researchers analyzed included data about walking intensity, or how fast the steps were taken. "We're interpreting these results with caution, but we did not find any striking association with walking intensity," she says. "There was no additional benefit with how fast you're walking, beyond the total number of steps that you accumulated."

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Common food dye can trigger inflammatory bowel diseases, animal study suggests

Long-term consumption of Allura Red food dye can be a potential trigger of inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis, says McMaster University's Waliul Khan. Researchers using experimental animal models of IBD found that continual exposure to Allura Red AC harms gut health and promotes inflammation.

The dye directly disrupts gut barrier function and increases the production of serotonin, a hormone/neurotransmitter found in the gut, which subsequently alters gut microbiota composition leading to increased susceptibility to colitis.

Khan said Allura Red (also called FD&C Red 40 and Food Red 17), is a common ingredient in candies, soft drinks, dairy products and some cereals. The dye is used to add colour and texture to foodstuffs, often to attract children.

The use of synthetic food dyes such as Allura Red has increased significantly over the last several decades, but there has been little earlier study of these dyes' effects on gut health. Khan and his team published their findings in Nature Communications. Yun Han (Eric) Kwon, who recently completed PhD in Khan's laboratory, is first author.

"This study demonstrates significant harmful effects of Allura Red on gut health and identifies gut serotonin as a critical factor mediating these effects. These findings have important implication in the prevention and management of gut inflammation," said Khan, the study's senior author, a professor of the Department of Pathology and Molecular Medicine and a principal investigator of Farncombe Family Digestive Health Research Institute.

"What we have found is striking and alarming, as this common synthetic food dye is a possible dietary trigger for IBDs. This research is a significant advance in alerting the public on the potential harms of food dyes that we consume daily," he said.

"The literature suggests that the consumption of Allura Red also affects certain allergies, immune disorders and behavioural problems in children, such as attention deficit hyperactivity disorder."

Khan said that IBDs are serious chronic inflammatory conditions of the human bowel that affect millions of people worldwide. While their exact causes are still not fully understood, studies have shown that dysregulated immune responses, genetic factors, gut microbiota imbalances, and environmental factors can trigger these conditions.

In recent years there has been significant progress in identifying susceptibility genes and understanding the role of the immune system and host microbiota in the pathogenesis of IBDs. However, similar advances in defining environmental risk factors have lagged, he said.

Khan said that environmental triggers for IBDs include the typical Western diet, which includes processed fats, red and processed meats, sugar and a lack of fibre. He added that the Western diet and processed food also includes large amounts of various additives and dyes.

He added that the study suggests a link between a commonly used food dye and IBDs and warrants further exploration between food dyes and IBDs at experimental, epidemiological and clinical levels.

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Early forests did not significantly change the atmospheric CO2

Scientists have discovered that the atmosphere contained far less CO2 than previously thought when forests emerged on our planet, the new study has important implications for understanding how land plants affect the climate.

The research has been led by the University of Copenhagen in collaboration with the University of Nottingham and alters 30 years of previous understanding. The study is published in Nature Communications.

Earth's continents were colonized by tall trees and forests about 385 million years ago. Before then, shallow shrub-like plants with vascular tissue, stems, shallow roots, and no flowers had invaded the land. Textbooks tell us that the atmosphere at that time had far higher CO2 levels than today and that an intense greenhouse effect led to a much warmer climate. The emergence of forests was previously thought to promote CO2 removal from the atmosphere, driving the Earth into a long cool period with ice cover at the poles.

Reconstructing atmospheric CO2 levels in the geological past is difficult and has previously relied on proxies that also depend on parameters that had to be assumed. Climate scientists agree that CO2 plays a crucial role in shaping Earth's climate both today and in the past. Therefore, a grand challenge for Earth scientist is to understand what has controlled the abundance CO2 in the atmosphere.

"We calibrated a mechanistic model for the gas-exchange between plant leaves and the ambient air to the oldest lineage of vascular land plants, namely clubmosses. With this approach, we could calculate the CO2 level in the air solely from observations made on the plant material," tells associate professor Tais W. Dahl from the Globe institute at University of Copenhagen, who led the study in collaboration with an international team of researchers from Germany, Saudi Arabia, UK, and USA.

The new method builds on three observations that can be made both in living plants and fossil plant tissue, including the ratio of two stable carbon isotopes and the size and density of stomata (pore openings) through which CO2 is taken up by the plant. The researchers calibrated the method in living clubmosses and found that this approach can accurately reproduce ambient CO2 levels in the greenhouse.

"The newly calibrated method to study CO2 levels from the geological record is superior to previous approaches that produce estimates with unbound error bars simply because they depend on parameters that cannot be independently constrained in the geological record," says Barry Lomax Professor at University of Nottingham and a co-author on the study.

The research team applied the method to some of the oldest vascular plant fossils that lived before and after trees evolved on our planet and discovered that the ratio of the two stable carbon isotopes, carbon-13 and carbon-12, is very similar to that of modern plants. Further, the stomata density and size were also very similar to that observed in their living descendants. These observations kickstarted a more thorough investigation of the early CO2 record.

Dahl and colleagues collected data from 66 fossils of three distinct species of club mosses found in 9 different localities worldwide 410 to 380 million years in age. In all cases, the atmospheric CO2 levels were only 30-70% higher (~525 -- 715 ppm) than today (~415 ppm). This is far lower than previously thought (2000-8000 ppm). Ppm stands for parts-per-million and is the unit used to measure carbon dioxide concentrations in air.

The team utilized a paleoclimate model to show that Earth was a temperate planet with mean tropical surface air temperatures of 24.1-24.6°C.

"We used a fully coupled atmosphere-ocean model to find that Earth had ice-covered poles when forests emerged. Yet, land plants could thrive in the tropical, subtropical and temperate zones," explains Georg Feulner from the Potsdam Institute for Climate in Germany, who co-authored the study.

The new study suggest that trees actually play an insignificant role on atmospheric CO2 levels over longer time scales because early trees had deeper root systems and produced more developed soils that are associated with lower nutrient loss. With more efficient nutrient recycling in soils, trees actually have a smaller weathering demand than the shallow shrub-like vegetation that came before them. This idea goes against previous thinking that trees with deeper root system promoted CO2 removal through enhanced chemical weathering and dissolution of silicate rocks.

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Cracking the mystery behind a deadly brain cancer

The brain cancer, glioblastoma, is a fierce and formidable opponent. Its millions of victims include Senator John McCain, President Biden's son, Beau, and famed film critic Gene Siskel, to name just a few. Most patients succumb within two years and few make it past five, a statistic that hasn't improved in decades due to lack of effective treatment options.

"The aggressiveness of glioblastoma is notorious," says Cold Spring Harbor Laboratory (CSHL) Professor Alea Mills. "The norm is to do surgery, treat with harsh drugs, and just hope for the best." But now, Mills and her colleagues have discovered in this deadly cancer a vulnerability, known as BRD8, that may finally lead to new treatment options and better patient outcomes.

The CSHL team recently solved a decades-old mystery surrounding glioblastoma's aggressiveness by linking the BRD8 protein to another protein, named P53. A staple in the body's natural cancer defenses, P53 prevents cells from overgrowing and turning into tumors. Almost all cancers depend on P53 becoming mutated and thus disabled. But weirdly, in the majority of glioblastoma cases, P53 is unscathed. "So why does this cancer act like P53 is broken?" asked CSHL postdoctoral fellow Xueqin Sun. This critical question led Mills' team to discover that BRD8 had gone rogue in glioblastoma, crippling P53 in a completely new way.

BRD8 shuts down access to genes in chromosomes. If a gene is wound up tightly, it cannot be used -- it's as if it were "asleep." Mills and her team revealed that BRD8 was inappropriately active in glioblastoma, keeping many of P53's critical anticancer defenses at rest. When the researchers inactivated BRD8 via genome editing, P53's "arsenal" suddenly woke up and began blocking tumor growth.

"It's like BRD8 is saying 'NO ENTRY' to P53's tumor-preventing power, but when we hit BRD8 in the right way -- go in there almost like a scalpel, but molecularly -- the tumor is annihilated," Mills explains. She and her team implanted tumor cells from glioblastoma patients into mice and watched the tumors grow in the brain. When BRD8 was inactivated, P53 was unlocked -- the tumors stopped growing and the mice lived longer.

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The other paleo diet: Rare discovery of dinosaur remains preserved with its last meal

Microraptor was an opportunistic predator, feeding on fish, birds, lizards -- and now small mammals. The discovery of a rare fossil reveals the creature was a generalist carnivore in the ancient ecosystem of dinosaurs.

Finding the last meal of any fossil animal is rare. When McGill University Professor Hans Larsson saw a complete mammal foot inside the rib cage of the small, feathered dinosaur, his jaw dropped. Of the many hundreds of carnivorous dinosaur skeletons, only 20 cases preserve their last meals. This new find makes 21.

"At first, I couldn't believe it. There was a tiny rodent-like mammal foot about a centimeter long perfectly preserved inside a Microraptor skeleton. These finds are the only solid evidence we have about the food consumption of these long extinct animals -- and they are exceptionally rare," says Larsson, who came across the fossil while visiting museum collections in China.

Microraptor was not a picky eater

Fully feathered with wings on both its arms and legs, this dinosaur is closely linked to the origin of birds. Microraptor was about the size of a crow and one of the smallest dinosaurs. The first specimen was discovered in deposits in Liaoning, China, in the early 2000s.

"We already know of Microraptor specimens preserved with parts of fish, a bird, and a lizard in their bellies. This new find adds a small mammal to their diet, suggesting these dinosaurs were opportunistic and not picky eaters," says Larsson who is a Professor of Biology at the Redpath Museum of McGill University.

"Knowing they were not specialized to any particular food is a big deal," he adds. According to the team of researchers, this could be the first evidence of a generalist carnivore in dinosaur ecosystems. Generalist predators are important stabilizers in today's ecosystems, like foxes and crows, because they can feed among several species that may have differing population abundances.

"Knowing that Microraptor was a generalist carnivore puts a new perspective on how ancient ecosystems may have worked and a possible insight into the success of these small, feathered dinosaurs," says Larsson.

From Science Daily

Exquisite views of distant galaxies

For decades, the Hubble Space Telescope and ground-based telescopes have provided us with spectacular images of galaxies. This all changed when the James Webb Space Telescope (JWST) launched in December 2021 and successfully completed commissioning during the first half of 2022. For astronomers, the universe, as we had seen it, is now revealed in a new way never imagined by the telescope's Near-Infrared Camera(NIRCam) instrument.

The NIRCam is Webb's primary imager that covers the infrared wavelength range from 0.6 to 5 microns. NIRCam detects light from the earliest stars and galaxies in the process of formation, the population of stars in nearby galaxies, as well as young stars in the Milky Way and Kuiper Belt objects.

The Prime Extragalactic Areas for Reionization and Lensing Science, or PEARLS, project is the subject of a recent study published in Astronomical Journal by a team of researchers, including Arizona State University School of Earth and Space Exploration Regents Professor Rogier Windhorst, Research Scientist Rolf Jansen, Associate Research Scientist Seth Cohen, Research Assistant Jake Summers and Graduate Associate Rosalia O'Brien, along with the contribution of many other researchers.

For researchers, the PEARLS program's images of the earliest galaxies show the amount of gravitational lensing of objects in the background of massive clusters of galaxies, allowing the team to see some of these very distant objects. In one of these relatively deep fields, the team has worked with stunning multicolor images to identify interacting galaxies with active nuclei.

Windhorst and his team's data show evidence for giant black holes in their center where you can see the accretion disc -- the stuff falling into the black hole, shining very brightly in the galaxy center. Plus, lots of galactic stars show up like drops on your car's windshields -- like you're driving through intergalactic space. This colorful field is straight up from the ecliptic plane, the plane in which the Earth and the moon, and all the other planets, orbit around the sun.

"For over two decades, I've worked with a large international team of scientists to prepare our Webb science program," Windhorst said. "Webb's images are truly phenomenal, really beyond my wildest dreams. They allow us to measure the number density of galaxies shining to very faint infrared limits and the total amount of light they produce. This light is much dimmer than the very dark infrared sky measured between those galaxies."

The first thing the team can see in these new images is that many galaxies that were next to or truly invisible to Hubble are bright in the images taken by Webb. These galaxies are so far away that the light emitted by stars has been stretched.

The team focused on the North Ecliptic Pole time domain field with the Webb telescope -- easily viewed due to its location in the sky. Windhorst and the team plan to observe it four times.

The first observations, consisting of two overlapping tiles, produced an image that shows objects as faint as the brightness of 10 fireflies at the distance of the moon (with the moon not there). The ultimate limit for Webb is one or two fireflies. The faintest reddest objects visible in the image are distant galaxies that go back to the first few hundred million years after the Big Bang.

For most of Jansen's career, he's worked with cameras on the ground and in space, where you have a single instrument with a single camera that produces one image. Now scientists have an instrument that has not just one detector or one image coming out of it, but 10 simultaneously. For every exposure NIRCam takes, it gives 10 of these images. That's a massive amount of data, and the sheer volume can be overwhelming.

To process that data and channel it through the analysis software of collaborators around the globe, Summers has been instrumental.

"The JWST images far exceed what we expected from my simulations prior to the first science observations," Summers said. "Analyzing these JWST images, I was most surprised by their exquisite resolution."

Jansen's primary interest is to figure out how galaxies like our own Milky Way came to be. And the way to do that is by looking far back in time at how galaxies came together, seeing how they evolved, effectively, and so tracing the path from the Big Bang to people like us.

"I was blown away by the first PEARLS images," Jansen said. "Little did I know, when I selected this field near the North Ecliptic Pole, that it would yield such a treasure trove of distant galaxies, and that we would get direct clues about the processes by which galaxies assemble and grow -- I can see streams, tails, shells and halos of stars in their outskirts, the leftovers of their building blocks."

Third-year astrophysics graduate student O'Brien designed algorithms to measure faint light between the galaxies and stars that first catch our eye.

"The diffuse light that I measured in between stars and galaxies has cosmological significance, encoding the history of the universe," O'Brien said. "I feel fortunate to start my career right now -- JWST data is like nothing we have ever seen, and I'm excited about the opportunities and challenges it offers."

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Ecology: More than the sum of its parts

Global warming, as a component of climate change, is probably one of the best-known risks to the ecological balance of ecosystems and global biodiversity. However, ecosystems worldwide are also exposed to many other human-induced global change factors (GCFs) -- with the number and intensity of simultaneously acting factors increasing. Examples include phenomena such as light pollution, i.e. the brightening of the night sky caused by artificial light sources, or the accumulation of pesticides, such as fungicides, in the environment.

"We have a pretty clear picture of how some of these factors individually can affect parts of an ecosystem, such as a plant community. In fact, their individual impacts on a community can be quite different and even opposite," explains Benedikt Speißer, first author of the recent study and doctoral student in the laboratory of Mark van Kleunen in the Department of Biology at the University of Konstanz. What happens when an ecosystem is exposed to several of these factors simultaneously has been less well studied, although this is likely the case in most natural ecosystems.

Experiments under controlled conditions

To address this lack of knowledge, the ecologists led by Mark van Kleunen investigated how simultaneously acting GCFs affect the composition and productivity of plant communities and what role the sheer number of factors plays in this. For this purpose, they created small artificial ecological communities -- generally known as mesocosms -- consisting of nine different grasses and forbs native to Central Europe, where the selected species are widespread and often co-occur. Under controlled conditions, the researchers subsequently exposed these mesocosms to different numbers -- 0, 1, 2, 4, or 6 -- of GCFs for a duration of several weeks.

"For our experiments, we selected GCFs that do indeed often act simultaneously on an ecosystem, but differ greatly in their respective chemical and physical natures," explains van Kleunen. Besides the GCFs already mentioned -- climate warming, light pollution and fungicide accumulation -- microplastic pollution, eutrophication, which is the accumulation of nutrients in an ecosystem, and soil salinization were additional factors studied.

Quantity not quality

The researchers found that as the number of GCFs acting simultaneously increases, so does biomass production in the plant communities. "The more GCFs, the higher the probability to include a highly influential factor, such as eutrophication. In these cases, one could expect higher productivity due to the high availability of nutrients," Speißer explains. However, the researchers' analyses showed that interactions between other factors can also contribute to this effect.

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Do polar bear paws hold the secret to better tire traction?

Traction is important. Humans have been continually interested in discovering how to better move across wet or frozen surfaces safely -- whether to improve shoes for walking on sidewalks or tires to maneuver the roadways. But what makes it possible for some arctic animals to walk and run across the ice so effortlessly and gracefully without slipping and falling? Three researchers from The University of Akron (UA) took a deep dive into the paws of polar bears to find out. Their research was published in the November issue of the Journal of the Royal Society Interface.

Why polar bears?

The project team included Ali Dhinojwala, the H.A. Morton Professor of Polymer Science in the School of Polymer Science and Polymer Engineering, Nathaniel Orndorf, a 2022 Ph.D. graduate who is now employed as a senior material scientist at Bridgestone Americas, and Austin Garner, a 2021 Ph.D. graduate who is now an assistant professor of biology at Syracuse University. The project began during the height of the pandemic when things were on lockdown.

"We had an ongoing project for many years focused on ice; we were looking at the friction of materials and we were interested in this topic because we are in Akron and our national partners need to develop tires with a strong grip on the road in ice and snow conditions," said Dhinojwala. "Nate had an interest in how nature has adapted to this solution for snow. The example that came to his mind was polar bears -- and the research began from there."

The project was very interdisciplinary, combining approaches and techniques from both biological and materials research. Orndorf and Dhinojwala are polymer scientists who integrate biology into their research, while Garner is an animal biologist who integrates materials science into his research.

The idea was to look at the paw pads of polar bears. Reviewing older literature, the team discovered that previous work studied the microstructures (papillae, the little bumps on the pad of the foot) of polar bear paws and asserted that the papillae were adaptations for improved traction on snow. The previous studies did not include other species of bear so Garner helped identify two species closely related to the polar bear (the brown bear and American black bear) and one distantly related (the sun bear) to include in the study.

"The quietness of the lab during COVID gave me the opportunity to connect with a variety of scientists and environmentalists across the country," said Orndorf. "I reached out to museums, taxidermists and many others to collect and view actual samples and replicas of bear paw pads."

Orndorf and Garner then prepared the paw pad samples from the bears and imaged them using a scanning electron microscope. The team also created 3D printouts of the structures to vary diameter and height of features. They were then tested in snow in the lab to see how they reacted to the conditions.

What the team discovered was that all bears (except sun bears) have papillae on their paw pads, but that the papillae on polar bears were taller -- up to 1.5 times. And, that the taller papillae of polar bears help to increase traction on snow relative to shorter ones. Even though polar bears have smaller paw pads compared to the other species (likely because of greater fur coverage for heat conservation), the taller papillae of polar bears compensate for their smaller paw pads, giving them a 30-50% increase in frictional shear stress.

"Papillae are not unique to polar bears. Previous work [in that area] made the implicit assumption that papillae themselves are adaptations for enhanced traction on snow without studying the paw pads of other bears. It was fascinating for us to discover that the other North American bears have them as well and that the physical characteristics of the papillae are what matters for traction on snow," said Garner.

Impact on traction

Now that the research has been published, other scientists and manufacturers can look at its application to their specific projects.

"If you look at snow tires you will see that they do have some deeper treads, but this research could also show various ways to design them that could have a larger impact," said Dhinojwala.

But the interest isn't just for tire manufacturers. "Individuals who do high altitude climbing are interested in this research, companies that specialize in the delivery of goods in bad weather would love to have better grip, etc." he added.

The same experiments could also be performed on animals such as dogs, wolves, foxes and mountain goats to determine if specific snow/ice induced surface roughness profiles are present in different animals, [TE1] or if nature has evolved different surface roughness profiles in order to increase traction on ice and snow, and which profile has the best performance.

Building on past research

This isn't the first research conducted in the area of traction or grip at UA. As part of the Biomimicry Research Center (BRIC) at The University of Akron, and in collaboration with faculty members in the BRIC program, Dhinojwala and his team have examined gecko adhesion, spider silk, mussel adhesion, and structural colors inspired by birds and other organisms. His research is supported by National Science Foundation, Air Force Office of Scientific Research and Industries.

His team is continuing to look at ice -- how ice formation takes place, ice adhesion, etc. Research that is very helpful for the automotive and aircraft industries. His students have just begun working with NASA on a grant funded project in this area.

"It's exciting to give our students such interesting research projects to be part of," said Dhinojwala. "They are an asset to our team, and many go on to continue to be excellent research partners after they leave UA."

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Serotonin 2C receptor associated with obesity and maladaptive behavior

A collaborative study involving Baylor College of Medicine, the University of Cambridge and the University of Exeter Medical School reveals a new gene associated with obesity and maladaptive behavior. The evidence shows that rare mutations in the gene for the serotonin 2C receptor play a role in the development of obesity and dysfunctional behaviors in humans and animal models. The findings, published in the journal Nature Medicine, have both diagnostic and therapeutic implications.

"Serotonin is a chemical produced in the brain that acts as a neurotransmitter, that is, it relays messages from one part of the brain to another. Serotonin communicates the message by binding to brain cells carrying serotonin receptors. These brain cells are involved in a variety of functions, including mood, appetite and some social behaviors, among others," said co-corresponding author Dr. Yong Xu, professor of pediatrics- nutrition and molecular and cellular biology at Baylor.

In the current study, the Xu lab and the lab of Dr. I. Sadaf Farooqi at the University of Cambridge, collaborated to investigate the role of one of the serotonin receptors, namely serotonin 2C receptor, in weight regulation and behavior. By combining the individual expertise of each lab -- basic and genetic animal studies in the Xu lab and human genetics in the Farooqi lab -- the team was able to make the case that serotonin 2C receptor is an important regulator of body weight and certain behaviors.

The project started with the finding that some children diagnosed with severe obesity carried rare mutations or variants of the serotonin 2C receptor gene. The researchers identified 13 different variants associated with obesity in 19 unrelated people. Further characterization of the variants revealed that 11 of them cause loss-of-function of the receptor.

"People who carried loss-of-function variants had hyperphagia, or an extreme appetite, some degree of maladaptive behavior and emotional lability, which refers to rapid, often exaggerated changes in mood including strong emotions such as uncontrollable laughing or crying or heightened irritability or temper," Xu said.

The researchers found that animal models carrying one of the human loss-of-function mutations also became obese, which confirmed the team's suspicion that loss-of-function mutations of the serotonin 2C receptor gene were involved in obesity.

"This is an important discovery from the diagnostic point of view," Xu said. "We suggest that the serotonin 2C receptor gene should be included in diagnostic gene panels for severe childhood-onset obesity."

In addition, the team identified a mechanism by which such mutations can lead to obesity. "We found that the serotonin 2C receptor is required to maintain normal firing activity of POMC neurons in the hypothalamus," Xu said. "When the receptor has a loss-of-function mutation, the firing activity of POMC neurons is impaired and as a result the animals overeat and become obese. A normal firing activity of these neurons is required to suppress overeating."

The researchers also worked with a mouse model to explore the connection between the loss-of-function mutations and behavior.

"We confirmed that having the mutation led to decreased sociability and increased aggression in mice," Xu said. "Before these findings, there was little evidence that the serotonin 2C receptor was required to maintain normal behavior and to prevent aggression. We are interested in investigating the mechanism."

At the translational level, the findings suggest that patients who develop obesity because of a loss-of-function mutation of this gene, might benefit from compounds that can bypass the deficit in the mutated receptor, such as setmelanotide, by acting directly on downstream pathways. Further studies need to be implemented to test this approach.

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Ancient asteroid grains provide insight into the evolution of our solar system

The UK's national synchrotron facility, Diamond Light Source, was used by a large, international collaboration to study grains collected from a near-Earth asteroid to further our understanding of the evolution of our solar system.

Researchers from the University of Leicester brought a fragment of the Ryugu asteroid to Diamond's Nanoprobe beamline I14 where a special technique called X-ray Absorption Near Edge Spectroscopy (XANES) was used to map out the chemical states of the elements within the asteroid material, to examine its composition in fine detail. The team also studied the asteroid grains using an electron microscope at Diamond's electron Physical Science Imaging Centre (ePSIC).

Julia Parker is the Principal Beamline Scientist for I14 at Diamond. She said: "The X-ray Nanoprobe allows scientists to examine the chemical structure of their samples at micron to nano lengthscales, which is complemented by the nano to atomic resolution of the imaging at ePSIC. It's very exciting to be able to contribute to the understanding of these unique samples, and to work with the team at Leicester to demonstrate how the techniques at the beamline, and correlatively at ePSIC, can benefit future sample return missions."

The data collected at Diamond contributed to a wider study of the space weathering signatures on the asteroid. The pristine asteroid samples enabled the collaborators to explore how space weathering can alter the physical and chemical composition of the surface of carbonaceous asteroids like Ryugu.

The researchers discovered that the surface of Ryugu is dehydrated and that it is likely that space weathering is responsible. The findings of the study, published today in Nature Astronomy, have led the authors to conclude that asteroids that appear dry on the surface may be water-rich, potentially requiring revision of our understanding of the abundances of asteroid types and the formation history of the asteroid belt.

Ryugu is a near-Earth asteroid, around 900 metres in diameter, first discovered in 1999 within the asteroid belt between Mars and Jupiter. It is named after the undersea palace of the Dragon God in Japanese mythology. In 2014, the Japanese state space agency JAXA launched Hayabusa2, an asteroid sample-return mission, to rendezvous with the Ryugu asteroid and collect material samples from its surface and sub-surface. The spacecraft returned to Earth in 2020, releasing a capsule containing precious fragments of the asteroid. These small samples were distributed to labs around the world for scientific study, including the University of Leicester's School of Physics & Astronomy and Space Park where John Bridges, one of the authors on the paper, is a Professor of Planetary Science.

John said: "This unique mission to gather samples from the most primitive, carbonaceous, building blocks of the Solar System needs the world's most detailed microscopy, and thats why JAXA and the Fine Grained Mineralogy team wanted us to analyse samples at Diamond's X-ray nanoprobe beamline. We helped reveal the nature of space weathering on this asteroid with micrometeorite impacts and the solar wind creating dehydrated serpentine minerals, and an associated reduction from oxidised Fe3+ to more reduced Fe2+.

It's important to build up experience in studying samples returned from asteroids, as in the Hayabusa2 mission, because soon there will be new samples from other asteroid types, the Moon and within the next 10 years Mars, returned to Earth. The UK community will be able to perform some of the critical analyses due to our facilities at Diamond and the electron microscopes at ePSIC."

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Alien planet found spiraling to its doom around an aging star

For the first time, astronomers have spotted an exoplanet whose orbit is decaying around an evolved, or older, host star. The stricken world appears destined to spiral closer and closer to its maturing star until collision and ultimate obliteration.

The discovery offers new insights into the long-winded process of planetary orbital decay by providing the first look at a system at this late stage of evolution.

Death-by-star is a fate thought to await many worlds and could be the Earth's ultimate adios billions of years from now as our Sun grows older.

"We've previously detected evidence for exoplanets inspiraling toward their stars, but we have never before seen such a planet around an evolved star," says Shreyas Vissapragada, a 51 Pegasi b Fellow at the Center for Astrophysics | Harvard & Smithsonian and lead author of a new study describing the results. "Theory predicts that evolved stars are very effective at sapping energy from their planets' orbits, and now we can test those theories with observations."

The findings were published Monday in The Astrophysical Journal Letters.

The ill-fated exoplanet is designated Kepler-1658b. As its name indicates, astronomers discovered the exoplanet with the Kepler space telescope, a pioneering planet-hunting mission that launched in 2009. Oddly enough, the world was the very first new exoplanet candidate Kepler ever observed. Yet it took nearly a decade to confirm the planet's existence, at which time the object entered Kepler's catalogue officially as the 1658th entry.

Kepler-1658b is a so-called hot Jupiter, the nickname given to exoplanets on par with Jupiter's mass and size but in scorchingly ultra-close orbits about their host stars. For Kepler-1658b, that distance is merely an eighth of the space between our Sun and its tightest orbiting planet, Mercury. For hot Jupiters and other planets like Kepler-1658b that are already very close to their stars, orbital decay looks certain to culminate in destruction.

Measuring the orbital decay of exoplanets has challenged researchers because the process is very slow and gradual. In the case of Kepler-1658b, according to the new study, its orbital period is decreasing at the miniscule rate of about 131 milliseconds (thousandths of a second) per year, with a shorter orbit indicating the planet has moved closer to its star.

Detecting this decline required multiple years of careful observation. The watch started with Kepler and then was picked up by the Palomar Observatory's Hale Telescope in Southern California and finally the Transiting Exoplanet Survey Telescope, or TESS, which launched in 2018. All three instruments captured transits, the term for when an exoplanet crosses the face of its star and causes a very slight dimming of the star's brightness. Over the past 13 years, the interval between Kepler-1658b's transits has slightly but steadily decreased.

The root cause of the orbital decay experienced by Kepler-1658b is tides -- the same phenomenon responsible for the daily rise and fall in Earth's oceans. Tides are generated by gravitational interactions between two orbiting bodies, such as between our world and the Moon or Kepler-1658b and its star. The bodies' gravities distort each other's shapes, and as the bodies respond to these changes, energy is released. Depending on the distances between, sizes, and rotation rates of the bodies involved, these tidal interactions can result in bodies pushing each other away -- the case for the Earth and the slowly outward-spiraling Moon -- or inward, as with Kepler-1658b toward its star.

There is still a lot researchers do not understand about these dynamics, particularly in star-planet scenarios. Accordingly, further study of the Kepler-1658 system should prove instructive.

The star has evolved to the point in its stellar life cycle where it has started to expand, just as our Sun is expected to, and has entered into what astronomers call a subgiant phase. The internal structure of evolved stars should more readily lead to dissipation of tidal energy taken from hosted planets' orbits compared to unevolved stars like our Sun. This accelerates the orbital decay process, making it easier to study on human timescales.

The results further help in explaining an intrinsic oddity about Kepler-1658b, which appears brighter and hotter than expected. The tidal interactions shrinking the planet's orbit may also be cranking out extra energy within the planet itself, the team says.

Vissapragada points to a similar situation with Jupiter's moon Io, the most volcanic body in the Solar System. The gravitational push-and-pull from Jupiter on Io melts the planet's innards. This molten rock then erupts out onto the moon's famously infernal, pizza-like surface of yellow sulfurous deposits and fresh red lava.

Stacking additional observations of Kepler-1658b should shed more light on celestial body interactions. And, with TESS slated to keep scrutinizing thousands of nearby stars, Vissapragada and colleagues expect the telescope to uncover numerous other instances of exoplanets circling down the drains of their host stars.

"Now that we have evidence of inspiraling of a planet around an evolved star, we can really start to refine our models of tidal physics," Vissapragada says. "The Kepler-1658 system can serve as a celestial laboratory in this way for years to come, and with any luck, there will soon be many more of these labs."

Vissapragada, who recently joined the Center for Astrophysics a few months ago and is now being mentored by Mercedes López-Morales, looks forward to the science of exoplanets continuing to dramatically advance.

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Fossil CSI: Giant extinct marine reptile graveyard was likely ancient birthing grounds

Today's marine giants -- such as blue and humpback whales -- routinely make massive migrations across the ocean to breed and give birth in waters where predators are scarce, with many congregating year after year along the same stretches of coastline. Now, new research from a team of scientists -- including researchers with the Smithsonian Institution, Vanderbilt University, the Natural History Museum of Utah, the University of Utah, University of Nevada, Reno, University of Edinburgh, University of Texas at Austin, Vrije Universiteit Brussels and University of Oxford -- suggests that nearly 200 million years before giant whales evolved, school bus-sized marine reptiles called ichthyosaurs may have been making similar migrations to breed and give birth together in relative safety.

The findings, published today in the journal Current Biology, examine a rich fossil bed in the renowned Berlin-Ichthyosaur State Park (BISP) in Nevada's Humboldt-Toiyabe National Forest, where many 50-foot-long ichthyosaurs (Shonisaurus popularis)lay petrified in stone. Led by Neil Kelley, Vanderbilt University scientist and former Smithsonian's National Museum of Natural History Peter Buck postdoctoral fellow, and co-authored by the museum's curator of fossil marine mammals Nicholas Pyenson, the study offers a plausible explanation as to how at least 37 of these marine reptiles came to meet their ends in the same locality -- a question that has vexed paleontologists for more than half a century.

"We present evidence that these ichthyosaurs died here in large numbers because they were migrating to this area to give birth for many generations across hundreds of thousands of years," Pyenson said. "That means this type of behavior we observe today in whales has been around for more than 200 million years."

Over the years, some paleontologists have proposed that BISP's ichthyosaurs -- predators resembling oversized chunky dolphins that have been adopted as Nevada's state fossil -- died in a mass stranding event such as those that sometimes afflicts modern whales, or that the creatures were poisoned by toxins from a nearby harmful algal bloom. The problem is that these hypotheses lack strong lines of scientific evidence to support them.

To try to solve this prehistoric mystery, the team combined newer paleontological techniques such as 3D scanning and geochemistry with traditional paleontological perseverance by poring over archival materials, photographs, maps, field notes and drawer after drawer of museum collections for shreds of evidence that could be reanalyzed.

Although most well-studied paleontological sites excavate fossils so they can be more closely studied by scientists at research institutions, the main attraction for visitors to the Nevada State Park-run BISP is a barn-like building that houses what researchers call Quarry 2, an array of ichthyosaurs that have been left embedded in the rock for the public to see and appreciate. Quarry 2 has partial skeletons from an estimated seven individual ichthyosaurs that all appear to have died around the same time.

"When I first visited the site in 2014, my first thought was that the best way to study it would be to create a full-color, high-resolution 3D model," Kelley said. "A 3D model would allow us to study the way these large fossils were arranged in relation to one another without losing the ability to go bone by bone."

To do this, Kelley, Pyenson and the research team collaborated with Jon Blundell, a member of the Smithsonian Digitization Program Office's 3D Program team, and Holly Little, a long-time collaborator with Pyenson and the 3D Program's team and currently the informatics manager in the museum's Department of Paleobiology. While Pyenson and Kelley were physically measuring bones and studying the site using traditional paleontological techniques, Little and Blundell used digital cameras and a spherical laser scanner to take hundreds of photographs and millions of point measurements that were then stitched together using specialized software to create a 3D model of the fossil bed.

To further home in on what might have befallen these extinct marine reptiles, the team collected tiny samples of the rock surrounding the fossils and performed a series of geochemical tests to look for signs of environmental disturbance.

One test measured mercury, which often accompanies large-scale volcanic activity, and found no significantly increased levels. Other tests examined different types of carbon and determined that there was no evidence of sudden increases in organic matter in the marine sediments that would result in a dearth of oxygen in the surrounding waters (though, like whales, the ichthyosaurs breathed air).

These geochemical tests revealed no signs that these ichthyosaurs perished because of some cataclysm that would have seriously disturbed the ecosystem in which they died. Kelley, Pyenson and other colleagues on the research team continued to look beyond Quarry 2 to the surrounding geology and all the fossils that had previously been excavated from the area.

The geologic evidence indicates that when the ichthyosaurs died, their bones eventually sank to the bottom of the sea, rather than along a shoreline shallow enough to suggest stranding, ruling out another hypothesis. Even more telling, though the area's limestone was chockfull of large adult Shonisaurus specimens, other marine vertebrates were scarce. The bulk of the other fossils at BISP come from small invertebrates such as clams and ammonites (spiral-shelled relatives of today's squid).

"There are so many large, adult skeletons from this one species at this site and almost nothing else," Pyenson said. "There are virtually no remains of things like fish or other marine reptiles for these ichthyosaursto feed on, and there are also no juvenile Shonisaurus skeletons."

The researchers' paleontological dragnet had eliminated some of the potential causes of death and started to provide intriguing clues about the type of ecosystem these marine predators were swimming in, but the evidence still did not clearly point to an alternative explanation.

The research team found a key piece of the puzzle when they discovered tiny ichthyosaur remains among new fossils collected at BISP and hiding within older museum collections. Careful comparison of the bones and teeth using micro-CT X-ray scans at Vanderbilt University revealed that these small bones were in fact embryonic and newborn Shonisaurus.

"Once it became clear that there was nothing for them to eat here, and there were large adult Shonisaurus along with embryos and newborns but no juveniles, we started to seriously consider whether this might have been a birthing ground," Kelley said.

Further analysis of the various strata in which the different clusters of ichthyosaur bones were found also revealed that the ages of the many fossil beds of BISP were separated by at least hundreds of thousands of years, if not millions.

"Finding these different spots with the same species spread across geologic time with the same demographic pattern tells us that this was a preferred habitat that these large oceangoing predators returned to for generations," Pyenson said. "This is a clear ecological signal, we argue, that this was a place that Shonisaurus used to give birth, very similar to today's whales. Now we have evidence that this sort of behavior is 230 million years old."

Kelley said the next step for this line of research is to investigate other ichthyosaur and Shonisaurus sites in North America with these new findings in mind to begin to recreate their ancient world -- perhaps by looking for other breeding sites or for places with greater diversity of other species that could have been rich feeding grounds for this extinct apex predator.

The 3D scans of the site are now available for other researchers to study and for the public to explore via the open-source Smithsonian's Voyager platform, which is developed and maintained by Blundell's team members at the Digitization Program Office. An interactive digital experience about the research team's study, including a 3D model of ichthyosaur sites analyzed, is also available on the Digitization Program Office's website.

"Our work is public," Blundell said. "We aren't just scanning sites and objects and locking them up. We create these scans to open up the collection to other researchers and members of the public who can't physically get to the Smithsonian."

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Climate change played key role in dinosaur success story

Climate change, rather than competition, played a key role in the ascendancy of dinosaurs through the Late Triassic and Early Jurassic periods.

According to new research, changes in global climate associated with the Triassic-Jurassic mass extinction -- which wiped out many large terrestrial vertebrates such as the giant armadillo-like aetosaurs -- actually benefitted the earliest dinosaurs.

In particular, sauropod-like dinosaurs, which became the giant herbivore species of the later Jurassic like Diplodocus and Brachiosaurus, were able to thrive and expand across new territories as the planet warmed up after the extinction event, 201 million years ago.

The new evidence is published in Current Biology, by an international team of palaeontologists led by the Universities of Birmingham and Bristol, in the UK, Friedrich-Alexander University Erlangen-Nu?rnberg (FAU), in Germany, and the University of São Paulo in Brazil.

The team compared computer models of prehistoric global climate conditions such as temperature and rainfall with data on the different locations of dinosaurs taken from sources such as the Paleobiology Database. They showed how the sauropods, and sauropod-like animals, with their long tails and necks and small heads, were the runaway success story of a turbulent period of evolution.

Dr Emma Dunne, now a lecturer in palaeontology at FAU, carried out the research while at the University of Birmingham. She said: "What we see in the data suggests that instead of dinosaurs being outcompeted by other large vertebrates, it was variations in climate conditions that were restricting their diversity. But once these conditions changed across the Triassic-Jurassic boundary, they were able to flourish.

"The results were somewhat surprising, because it turns out that sauropods were really fussy from the get-go: later in their evolution they continue to stay in warmer areas and avoid polar regions."

Co-author on the paper, Professor Richard Butler, at the University of Birmingham, said: "Climate change appears to have been really important in driving the evolution of early dinosaurs. What we want to do next is use the same techniques to understand the role of climate in the next 120 million years of the dinosaur story."

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Webb Space Telescope reveals previously shrouded newborn stars

Rice University astronomer Megan Reiter and colleagues took a "deep dive" into one of the first images from NASA's James Webb Space Telescope and were rewarded with the discovery of telltale signs from two dozen previously unseen young stars about 7,500 light years from Earth.

The published research in the December issue of the Monthly Notices of the Royal Astronomical Society offers a glimpse of what astronomers will find with Webb's near-infrared camera. The instrument is designed to peer through clouds of interstellar dust that have previously blocked astronomers' view of stellar nurseries, especially those that produce stars similar to Earth's sun.

Reiter, an assistant professor of physics and astronomy, and co-authors from the California Institute of Technology, the University of Arizona, Queen Mary University in London and the United Kingdom's Royal Observatory in Edinburgh, Scotland, analyzed a portion of Webb's first images of the Cosmic Cliffs, a star-forming region in a cluster of stars known as NGC 3324.

"What Webb gives us is a snapshot in time to see just how much star formation is going on in what may be a more typical corner of the universe that we haven't been able to see before," said Reiter, who led the study.

Located in the southern constellation Carina, NGC 3324 hosts several well-known regions of star formation that astronomers have studied for decades. Many details from the region have been obscured by dust in images from the Hubble Space Telescope and other observatories. Webb's infrared camera was built to see through dust in such regions and to detect jets of gas and dust that spew from the poles of very young stars.

Reiter and colleagues focused their attention on a portion of NGC 3324 where only a few young stars had previously been found. By analyzing a specific infrared wavelength, 4.7 microns, they discovered two dozen previously unknown outflows of molecular hydrogen from young stars. The outflows range in size, but many appear to come from protostars that will eventually become low-mass stars like Earth's sun.

"The findings speak both to how good the telescope is and to how much there is going on in even quiet corners of the universe," Reiter said.

Within their first 10,000 years, newborn stars gather material from the gas and dust around them. Most young stars eject a fraction of that material back into space via jets that stream out in opposite directions from their poles. Dust and gas pile up in front of the jets, which clear paths through nebular clouds like snowplows. One vital ingredient for baby stars, molecular hydrogen, gets swept up by these jets and is visible in Webb's infrared images.

"Jets like these are signposts for the most exciting part of the star formation process," said study co-author Nathan Smith of the University of Arizona. "We only see them during a brief window of time when the protostar is actively accreting."

The accretion period of early star formation has been especially difficult for astronomers to study because it is fleeting -- usually just a few thousand years in the earliest portion of a star's multimillion-year childhood.

Study co-author Jon Morse of the California Institute of Technology said jets like those discovered in the study "are only visible when you embark on that deep dive -- dissecting data from each of the different filters and analyzing each area alone.

"It's like finding buried treasure," Morse said.

Reiter said the size of the Webb telescope also played a role in the discovery.

"It's just a huge light bucket," Reiter said. "That lets us see smaller things that we might have missed with a smaller telescope. And it also gives us really good angular resolution. So we get a level of sharpness that allows us to see relatively small features, even in faraway regions."

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Light from outside our galaxy brighter than expected

Scientists analyzed new measurements showing that the light emitted by stars outside our galaxy is two to three times brighter than the light from known populations of galaxies, challenging assumptions about the number and environment of stars are in the universe. Results of the study led by researchers at Rochester Institute of Technology have been posted to ArXiv and accepted for publication in The Astrophysical Journal.

The research team analyzed hundreds of images of background light taken by the Long-Range Reconnaissance Imager (LORRI) on NASA's New Horizons mission to calculate the cosmic optical background (COB) -- the sum of light emitted by stars beyond the Milky Way over the history of the universe. If the COB brightness doesn't equal the light from galaxies we know about, it suggests there might be missing sources of optical light in the universe.

"We see more light than we should see based on the populations of galaxies that we understand to exist and how much light we estimate they should produce," said Teresa Symons '22 Ph.D. (astrophysical sciences and technology), who led the study for her dissertation and is now a postdoctoral researcher at University of California Irvine. "Determining what is producing that light could change our fundamental understanding of how the universe formed over time."

Earlier this year, an independent team of scientists reported the COB was twice as large as originally believed in Astrophysical Journal Letters. Those results were no fluke, as corroborated using a much broader set of LORRI observations in the new study by Symons, RIT Associate Professor Michael Zemcov, and researchers at the Jet Propulsion Laboratory at Caltech, UC Irvine, UC Berkeley, and Johns Hopkins University.

While an unobscured measurement of the COB is difficult to achieve from the Earth due to dust between planets, the New Horizons spacecraft is at the edge of our solar system where this foreground is minimal and provides a much clearer view for this type of study. The scientists hope that future missions and instruments can be developed to help explore the discrepancy.

"This has gotten to the point where it's an actual mystery that needs to be solved," said Zemcov, a research professor at RIT's Center for Detectors and School of Physics and Astronomy. "I hope that some of the experiments we're involved in here at RIT including CIBER-2 and SPHEREx can help us resolve the discrepancy."

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