Potential threat to heart health from extreme weather

An analysis in nearly 2.3 million Europeans has found detrimental associations between cold weather and deaths from heart disease, particularly in poor neighbourhoods. The late-breaking research is presented at ESC Congress 2022.1 Hot weather was linked with excess deaths from heart disease and stroke in patients with heart conditions.

Study author Professor Stefan Agewall of the University of Oslo, Norway said: "Climate change is leading to a rise in the average global temperature but also extreme cold in some regions. More than 70,000 excess deaths occurred across Europe during the summer of 2003 due to intense heatwaves.2 Cold weather also accounts for excess deaths and hospital admissions.3,4 Previously studies on the cardiovascular effects of heat and cold mainly used aggregated data, such as daily deaths in a city. The EXHAUSTION project used individual data, enabling us to identify vulnerable subgroups for protective interventions, thereby increasing resilience for future weather events."

The analysis included 2.28 million adults from five cohort studies conducted in Italy, Germany, the UK, Norway, and Sweden between 1994 and 2010. The average age ranged from 49.7 years to 71.7 years and the proportion of women ranged from 36.0% to 54.5%. Participants with and without cardiovascular disease at baseline were included. Data on mortality and new-onset disease were collected through death and disease registries and follow up surveys. Daily average air temperatures at participants' home addresses were collected from local weather stations or estimated using modelling of temperature data from weather stations

The relationships between temperature and cardiovascular conditions and death were analysed for all participants and in subgroups with particular characteristics. A time-stratified case-crossover study design was used where for each participant, the researchers compared the temperature on the day of the week an adverse event occurred (e.g. Monday) with the temperature on the same day of the week without an adverse event (e.g. all remaining Mondays) within the same month. Using within-participant comparisons between days in the same month eliminated the potential confounding effects of participant characteristics and time trends.

The analysis found increased risks of death from cardiovascular disease overall and ischaemic heart disease in particular, as well as an elevated risk of new-onset ischaemic heart disease, associated with cold weather. With an approximately 10°C temperature drop, from 5°C to -5°C, there was a 19% greater risk of death from cardiovascular disease (relative risk [RR] 1.19; 95% confidence interval [CI] 1.04-1.36) and a 22% elevated likelihood of death from ischaemic heart disease (RR 1.22; 95% CI 1.07-1.38). There was a 4% higher risk of new-onset ischaemic heart disease associated with an approximately 11°C temperature drop, from 2°C to -9°C (RR 1.04; 95% CI: 1.01-1.08).

Professor Agewall said: "The relationships between cold temperatures and deaths were more pronounced in men and people living in neighbourhoods with a low socioeconomic status. The links between cold and new-onset ischaemic heart disease were stronger among women and people older than 65 years."

Heat was not related to detrimental effects in the overall study population. However, temperature rises from 15°C to 24°C were associated with 25% (RR 1.25; 95% CI 1.12-1.39) and 30% (RR 1.30; 95% CI 1.10-1.53) elevated risks of death from cardiovascular disease and stroke, respectively, in people with heart disease at baseline.

Professor Agewall said: "Clinicians can use this information to provide tailored advice to those most at risk of adverse health outcomes during hot and cold days. Patients with heart conditions should stay hydrated in hot weather and adhere to advice from their cardiologist on medication use. We can all check the news for extreme heat and cold alerts and follow safety tips from local authorities."

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A historical perspective on glacial retreat

Glaciers are melting rapidly -- and since the 2000s, scientists have been recording and researching changes in their volume more and more precisely. In contrast, hardly anything is known about how glaciers changed during the 20th century. Although there are a handful of studies that reconstruct the surface topography of individual glaciers in the late 19th and early 20th centuries, these partially show large discrepancies with existing models when it comes to estimating the corresponding glacier volume.

In a study that has just been published in the scientific journal The Cryosphere, a team of researchers from ETH Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL have reconstructed the topography of all Swiss glaciers in 1931. Based on these reconstructions and comparisons with data from the 2000s, the researchers conclude that the glacier volume halved between 1931 and 2016.

Old data -- new insights

For their reconstruction, the glaciologists turned to what is known as stereophotogrammetry, a technique that can be used to determine the nature, shape and position of any object on the basis of image pairs. This technique has long been in use in Switzerland: from the First World War until the end of the 1940s, engineers from the Swiss National Survey -- today swisstopo -- surveyed large swathes of the Swiss Alps from some 7,000 locations using phototheodolites (a combination of a camera and an angle measuring device).

The resulting glass plate images, which swisstopo has digitised and enriched with metadata from field books, are now available to the public through the TerrA image archive. The researchers used the material from this image archive, which covers about 86 percent of the glacierised area of Switzerland. They analysed around 21,700 photographs taken between 1916 and 1947. "Based on these photos, we determined the glacier surface topography. If we know the surface topography of a glacier at two different points in time, we can calculate the difference in ice volume," explains lead author Erik Schytt Mannerfelt of ETH Zurich and WSL. Since the images were taken in different years, the researchers decided to use the mean year 1931 as a reference and reconstructed the surface topography of all glaciers for that year.

Not all glaciers are under observation

To date, the picture of glacier changes during the last century has been largely based on a combination of long-term glacier observations, measurements performed in the field and aerial photographs taken after 1960. From this information, glaciologists reconstructed the mass balance of individual glaciers -- that is, the difference between mass gain and mass loss.

One way to determine a glacier's mass balance is through on-site measurements. But only a few Swiss glaciers -- the Claridenfirn, for example -- have been the subject of regular measurements. This means that long time series stretching over several decades are very rare. In addition, older mass balance series can accumulate errors from earlier, inaccurate or uncertain measurements, which can lead to large distortions.

Not all glaciers are equally affected

The study further shows that not all glaciers are losing mass at the same rate. The extent to which they have decreased in volume depends primarily on three factors: first, the altitude at which a glacier is located; second, how flat the glacier snout is; and third, the amount of debris on the glacier.

So have the glaciers just been receding every year? No. While the climate in the 20th century was generally unfavourable for glaciers, in the 1920s and 1980s there was sporadic glacier mass growth, with individual glaciers advancing. "While there may have been growth over short-term periods, it's important to keep the big picture in mind. Our comparison between the years 1931 and 2016 clearly shows that there was significant glacial retreat during this period," says Daniel Farinotti, Professor of Glaciology at ETH Zurich and WSL, and co-author of the study. What's more, the total glacier volume is decreasing at an ever faster rate, as confirmed by the glacier monitoring network GLAMOS, which is managed by ETH Zurich. By way of comparison, while glaciers lost half their volume between 1931 and 2016, they lost a further 12 percent between 2016 and 2021 -- i.e. in just six years.

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Good sleepers have lower risk of heart disease and stroke

Nine in ten people do not get a good night's sleep, according to research presented at ESC Congress 2022.1 The study found that suboptimal sleep was associated with a higher likelihood of heart disease and stroke. The authors estimated that seven in ten of these cardiovascular conditions could be prevented if everyone was a good sleeper.

"The low prevalence of good sleepers was expected given our busy, 24/7 lives," said study author Dr. Aboubakari Nambiema of INSERM (the French National Institute of Health and Medical Research), Paris, France. "The importance of sleep quality and quantity for heart health should be taught early in life when healthy behaviours become established. Minimising night-time noise and stress at work can both help improve sleep."

Previous studies on sleep and heart disease have generally focused on one sleep habit, such as sleep duration or sleep apnoea, where breathing stops and starts while sleeping. In addition, prior studies have often assessed sleep at baseline only. The current study used a healthy sleep score combining five sleep habits. The researchers investigated the association between the baseline sleep score, and changes over time in the sleep score, and incident cardiovascular disease.

This study included 7,200 participants of the Paris Prospective Study III (PPP3), an observational community-based prospective cohort. Men and women aged 50 to 75 years and free of cardiovascular disease were recruited in a preventive medical centre between 2008 and 2011. The average age was 59.7 years and 62% were men. Participants underwent a physical examination and completed questionnaires on lifestyle, personal and family medical history, and medical conditions.

Questionnaires were used to collect information on five sleep habits at baseline and two follow up visits. Each factor was given 1 point if optimal and 0 if not. A healthy sleep score ranging from 0 to 5 was calculated, with 0 or 1 considered poor and 5 considered optimal. Those with an optimal score reported sleeping 7 to 8 hours per night, never or rarely having insomnia, no frequent excessive daytime sleepiness, no sleep apnoea, and an early chronotype (being a morning person). The researchers checked for incident coronary heart disease and stroke every two years for a total of 10 years.

At baseline, 10% of participants had an optimal sleep score and 8% had a poor score. During a median follow up of eight years, 274 participants developed coronary heart disease or stroke. The researchers analysed the association between sleep scores and cardiovascular events after adjusting for age, sex, alcohol consumption, occupation, smoking, body mass index, physical activity, cholesterol level, diabetes, and family history of heart attack, stroke or sudden cardiac death. They found that the risk of coronary heart disease and stroke decreased by 22% for every 1 point rise in the sleep score at baseline. More specifically, compared to those with a score of 0 or 1, participants with a score of 5 had a 75% lower risk of heart disease or stroke.

The researchers estimated the proportion of cardiovascular events that could be prevented with healthier sleep. They found that if all participants had an optimal sleep score, 72% of new cases of coronary heart disease and stroke might be avoided each year.

Over two follow ups, almost half of participants (48%) changed their sleep score: in 25% it decreased whereas in 23% it improved. When the researchers examined the association between the change in score and cardiovascular events, they found that a 1 point increment over time was associated with a 7% reduction in the risk of coronary heart disease or stroke.

Dr. Nambiema said: "Our study illustrates the potential for sleeping well to preserve heart health and suggests that improving sleep is linked with lower risks of coronary heart disease and stroke. We also found that the vast majority of people have sleep difficulties. Given that cardiovascular disease is the top cause of death worldwide, greater awareness is needed on the importance of good sleep for maintaining a healthy heart."

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What makes the human brain different? Study reveals clues

What makes the human brain distinct from that of all other animals -- including even our closest primate relatives? In an analysis of cell types in the prefrontal cortex of four primate species, Yale researchers identified species-specific -- particularly human-specific -- features, they report Aug. 25 in the journal Science.

And they found that what makes us human may also makes us susceptible to neuropsychiatric diseases.

For the study, the researchers looked specifically at the dorsolateral prefrontal cortex (dlPFC), a brain region that is unique to primates and essential for higher-order cognition. Using a single cell RNA-sequencing technique, they profiled expression levels of genes in hundreds of thousands of cells collected from the dlPFC of adult humans, chimpanzees, macaque, and marmoset monkeys.

"Today, we view the dorsolateral prefrontal cortex as the core component of human identity, but still we don't know what makes this unique in humans and distinguishes us from other primate species." said Nenad Sestan, the Harvey and Kate Cushing Professor of Neuroscience at Yale, professor of comparative medicine, of genetics. and of psychiatry, and the lead senior author of the paper. "Now we have more clues."

To answer this, the researchers first asked whether there are there any cell types uniquely present in humans or other analyzed non-human primate species. After grouping cells with similar expression profiles they revealed 109 shared primate cell types but also five that were not common to all species. These included a type of microglia, or brain-specific immune cell, that was present only in humans and a second type shared by only humans and chimpanzees.

The human-specific microglia type exists throughout development and adulthood, the researchers found, suggesting the cells play a role in maintenance of the brain upkeep rather than combatting disease.

"We humans live in a very different environment with a unique lifestyle compared to other primate species; and glia cells, including microglia, are very sensitive to these differences," Sestan said. "The type of microglia found in the human brain might represent an immune response to the environment."

An analysis of gene expression in the microglia revealed another human-specific surprise -- the presence of the gene FOXP2. This discovery raised great interest because variants of FOXP2 have been linked to verbal dyspraxia, a condition in which patients have difficulty producing language or speech. Other studies have also shown that FOXP2 is associated with other neuropsychiatric diseases, such as autism, schizophrenia, and epilepsy.

Sestan and colleagues found that this gene exhibits primate-specific expression in a subset of excitatory neurons and human-specific expression in microglia.

"FOXP2 has intrigued many scientists for decades, but still we had no idea of what makes it unique in humans versus other primate species," said Shaojie Ma, a postdoctoral associate in Sestan's lab and co-lead author. We are extremely excited about the FOXP2 findings because they open new directions in the study of language and diseases."

Read more at Science Daily

NASA's Webb detects carbon dioxide in exoplanet atmosphere

NASA's James Webb Space Telescope has captured the first clear evidence for carbon dioxide in the atmosphere of a planet outside the solar system. This observation of a gas giant planet orbiting a Sun-like star 700 light-years away provides important insights into the composition and formation of the planet. The finding, accepted for publication in Nature, offers evidence that in the future Webb may be able to detect and measure carbon dioxide in the thinner atmospheres of smaller rocky planets.

WASP-39 b is a hot gas giant with a mass roughly one-quarter that of Jupiter (about the same as Saturn) and a diameter 1.3 times greater than Jupiter. Its extreme puffiness is related in part to its high temperature (about 1,600 degrees Fahrenheit or 900 degrees Celsius). Unlike the cooler, more compact gas giants in our solar system, WASP-39 b orbits very close to its star -- only about one-eighth the distance between the Sun and Mercury -- completing one circuit in just over four Earth-days. The planet's discovery, reported in 2011, was made based on ground-based detections of the subtle, periodic dimming of light from its host star as the planet transits, or passes in front of the star.

Previous observations from other telescopes, including NASA's Hubble and Spitzer space telescopes, revealed the presence of water vapor, sodium, and potassium in the planet's atmosphere. Webb's unmatched infrared sensitivity has now confirmed the presence of carbon dioxide on this planet as well.

Filtered Starlight

Transiting planets like WASP-39 b, whose orbits we observe edge-on rather than from above, can provide researchers with ideal opportunities to probe planetary atmospheres.

During a transit, some of the starlight is eclipsed by the planet completely (causing the overall dimming) and some is transmitted through the planet's atmosphere.

Because different gases absorb different combinations of colors, researchers can analyze small differences in brightness of the transmitted light across a spectrum of wavelengths to determine exactly what an atmosphere is made of. With its combination of inflated atmosphere and frequent transits, WASP-39 b is an ideal target for transmission spectroscopy.

First Clear Detection of Carbon Dioxide

The research team used Webb's Near-Infrared Spectrograph (NIRSpec) for its observations of WASP-39b. In the resulting spectrum of the exoplanet's atmosphere, a small hill between 4.1 and 4.6 microns presents the first clear, detailed evidence for carbon dioxide ever detected in a planet outside the solar system.

"As soon as the data appeared on my screen, the whopping carbon dioxide feature grabbed me," said Zafar Rustamkulov, a graduate student at Johns Hopkins University and member of the JWST Transiting Exoplanet Community Early Release Science team, which undertook this investigation. "It was a special moment, crossing an important threshold in exoplanet sciences."

No observatory has ever measured such subtle differences in brightness of so many individual colors across the 3 to 5.5-micron range in an exoplanet transmission spectrum before. Access to this part of the spectrum is crucial for measuring abundances of gases like water and methane, as well as carbon dioxide, which are thought to exist in many different types of exoplanets.

"Detecting such a clear signal of carbon dioxide on WASP-39 b bodes well for the detection of atmospheres on smaller, terrestrial-sized planets," said Natalie Batalha of the University of California at Santa Cruz, who leads the team.

Understanding the composition of a planet's atmosphere is important because it tells us something about the origin of the planet and how it evolved. "Carbon dioxide molecules are sensitive tracers of the story of planet formation," said Mike Line of Arizona State University, another member of this research team. "By measuring this carbon dioxide feature, we can determine how much solid versus how much gaseous material was used to form this gas giant planet. In the coming decade, JWST will make this measurement for a variety of planets, providing insight into the details of how planets form and the uniqueness of our own solar system."

Early Release Science

This NIRSpec prism observation of WASP-39 b is just one part of a larger investigation that includes observations of the planet using multiple Webb instruments, as well as observations of two other transiting planets. The investigation, which is part of the Early Release Science program, was designed to provide the exoplanet research community with robust Webb data as soon as possible.

"The goal is to analyze the Early Release Science observations quickly and develop open-source tools for the science community to use," explained Vivien Parmentier, a co-investigator from Oxford University. "This enables contributions from all over the world and ensures that the best possible science will come out of the coming decades of observations."

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30-million-year-old amphibious beaver fossil is oldest ever found

A new analysis of a beaver anklebone fossil found in Montana suggests the evolution of semi-aquatic beavers may have occurred at least 7 million years earlier than previously thought, and happened in North America rather than Eurasia.

In the study, Ohio State University evolutionary biologist Jonathan Calede describes the find as the oldest known amphibious beaver in the world and the oldest amphibious rodent in North America. He named the newly discovered species Microtheriomys articulaquaticus.

Calede's findings resulted from comparing measurements of the new species' anklebone to about 340 other rodent specimens to categorize how it moved around in its environment -- which indicated this animal was a swimmer. The Montana-based bone was determined to be 30 million years old -- the oldest previously identified semi-aquatic beaver lived in France 23 million years ago.

Beavers and other rodents can tell us a lot about mammalian evolution, said Calede, an assistant professor of evolution, ecology and organismal biology at Ohio State's Marion campus.

"Look at the diversity of life around us today, and you see gliding rodents like flying squirrels, rodents that hop like the kangaroo rat, aquatic species like muskrats, and burrowing animals like pocket gophers. There is an incredible diversity of shapes and ecologies. When that diversity arose is an important question," Calede said. "Rodents are the most diverse group of mammals on Earth, and about 4 in 10 species of mammals are rodents. If we want to understand how we get incredible biodiversity, rodents are a great system to study."

The research is published online today (Aug. 24, 2022) in the journal Royal Society Open Science.

The scientists, including Calede, who found the bones and teeth of the new beaver species in western Montana knew they came from beavers right away because of their recognizable teeth. But the discovery of an anklebone, about 10 millimeters long, opened up the possibility of learning much more about the animal's life. The astragalus bone in beavers is the equivalent to the talus in humans, located where the shin meets the top of the foot.

Calede took 15 measurements of the anklebone fossil and compared it to measurements -- over 5,100 in all -- of similar bones from 343 specimens of rodent species living today that burrow, glide, jump and swim as well as ancient beaver relatives.

Running computational analyses of the data in multiple ways, he arrived at a new hypothesis for the evolution of amphibious beavers, proposing that they started to swim as a result of exaptation -- the co-opting of an existing anatomy -- leading, in this case, to a new lifestyle.

"In this case, the adaptations to burrowing were co-opted to transition to a semi-aquatic locomotion," he said. "The ancestor of all beavers that have ever existed was most likely a burrower, and the semi-aquatic behavior of modern beavers evolved from a burrowing ecology. Beavers went from digging burrows to swimming in water.

"It's not necessarily surprising because movement through dirt or water requires similar adaptations in skeletons and muscles."

Fossils of fish and frogs and the nature of the rocks where Microtheriomys articulaquaticus fossils were found suggested it had been an aquatic environment, providing additional evidence to support the hypothesis, Calede said.

Fossils are usually dated based on their location between layers of rocks whose age is determined by the detection of the radioactive decay of elements left behind by volcanic activity. But in this case, Calede was able to age the specimen at a precise 29.92 million years old because of its location within, rather than above or below, a layer of ashes.

"The oldest semi-aquatic beaver we knew of in North America before this was 17 or 18 million years old," he said. "And the oldest aquatic beaver in the world, before this one, was from France and is about 23 million years old.

"I'm not claiming this new species is necessarily the oldest aquatic beaver ever, because there are other animals that we know, from their teeth, that are related to this species I described."

Microtheriomys articulaquaticus did not have the flat tail that helps beavers swim today. It likely ate plants instead of wood and was comparably small -- weighing less than 2 pounds. The modern adult beaver, weighing 50 pounds or so, is the second-largest living rodent after the capybara from South America.

Calede's analysis of beaver body size over the past 34 million years suggests beaver evolution adheres to what is known as Cope's Rule, which posits that organisms in evolving lineages increase in size over time. A giant beaver the size of a black bear lived in North America as recently as about 12,000 years ago. Like all but the two beaver species living today, Castor canadensis and Castor fiber, the giant beaver is extinct.

"It looks like when you follow Cope's Rule, it's not good for you -- it sets you on a bad path in terms of species diversity," Calede said. "We used to have dozens of species of beavers in the fossil record. Today we have one North American beaver and one Eurasian beaver. We've gone from a group that is super diverse and doing so well to one that is obviously not so diverse anymore."

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Social media experiment reveals potential to 'inoculate' millions of users against misinformation

Short animations giving viewers a taste of the tactics behind misinformation can help to "inoculate" people against harmful content on social media when deployed in YouTube's advert slot, according to a major online experiment led by the University of Cambridge.

Working with Jigsaw (https://jigsaw.google.com/), a unit within Google dedicated to tackling threats to open societies, a team of psychologists from the universities of Cambridge and Bristol created 90-second clips designed to familiarise users with manipulation techniques such as scapegoating and deliberate incoherence.

This "pre-bunking" strategy pre-emptively exposes people to tropes at the root of malicious propaganda, so they can better identify online falsehoods regardless of subject matter.

Researchers behind the Inoculation Science project (https://inoculation.science/) compare it to a vaccine: by giving people a "micro-dose" of misinformation in advance, it helps prevent them falling for it in future -- an idea based on what social psychologist's call "inoculation theory."

The findings, published in Science Advances, come from seven experiments involving a total of almost 30,000 participants -- including the first "real world field study" of inoculation theory on a social media platform -- and show a single viewing of a film clip increases awareness of misinformation.

The videos introduce concepts from the "misinformation playbook," illustrated with relatable examples from film and TV such as Family Guy or, in the case of false dichotomies, Star Wars ("Only a Sith deals in absolutes").

"YouTube has well over 2 billion active users worldwide. Our videos could easily be embedded within the ad space on YouTube to prebunk misinformation," said study co-author Prof Sander van der Linden, Head of the Social Decision-Making Lab (SDML) at Cambridge, which led the work.

"Our research provides the necessary proof of concept that the principle of psychological inoculation can readily be scaled across hundreds of millions of users worldwide."

Lead author Dr Jon Roozenbeek from Cambridge's SDML describes the team's videos as "source agnostic," avoiding biases people have about where information is from, and how it chimes -- or not -- with what they already believe.

"Our interventions make no claims about what is true or a fact, which is often disputed. They are effective for anyone who does not appreciate being manipulated," he said.

"The inoculation effect was consistent across liberals and conservatives. It worked for people with different levels of education, and different personality types. This is the basis of a general inoculation against misinformation."

Google -- YouTube's parent company -- is already harnessing the findings. At the end of August, Jigsaw will roll out a prebunking campaign across several platforms in Poland, Slovakia, and the Czech Republic to get ahead of emerging disinformation relating to Ukrainian refugees. The campaign is designed to build resilience to harmful anti-refugee narratives, in partnership with local NGOs, fact checkers, academics, and disinformation experts.

"Harmful misinformation takes many forms, but the manipulative tactics and narratives are often repeated and can therefore be predicted," said Beth Goldberg, co-author and Head of Research and Development for Google's Jigsaw unit.

"Teaching people about techniques like ad-hominem attacks that set out to manipulate them can help build resilience to believing and spreading misinformation in the future.

"We've shown that video ads as a delivery method of prebunking messages can be used to reach millions of people, potentially before harmful narratives take hold," Goldberg said.

The team argue that pre-bunking may be more effective at fighting the misinformation deluge than fact-checking each untruth after it spreads -- the classic 'debunk' -- which is impossible to do at scale, and can entrench conspiracy theories by feeling like personal attacks to those who believe them.

"Propaganda, lies and misdirections are nearly always created from the same playbook," said co-author Prof Stephan Lewandowsky from the University of Bristol. "We developed the videos by analysing the rhetoric of demagogues, who deal in scapegoating and false dichotomies."

"Fact-checkers can only rebut a fraction of the falsehoods circulating online. We need to teach people to recognise the misinformation playbook, so they understand when they are being misled."

Six initial controlled experiments featured 6,464 participants, with the sixth experiment conducted a year after the first five to ensure earlier findings could be replicated.

Data collection for each participant was comprehensive, from basic information -- gender, age, education, political leanings -- to levels of numeracy, conspiratorial thinking, news and social media checking, "bullshit receptivity," and a personality inventory, among other "variables."

Factoring all this in, the team found that inoculation videos improved people's ability to spot misinformation, and boosted their confidence in being able to do so again. The clips also improve the quality of "sharing decisions": whether or not to spread damaging content.

Two of the animations were then tested "in the wild" as part of a vast experiment on YouTube, with clips positioned in the pre-video advert slot that provides an option to skip after five seconds.

Google Jigsaw exposed around 5.4 million US YouTubers to an inoculation video, with almost a million watching for at least 30 seconds. The platform then gave a random 30% of users that watched a voluntary test question within 24 hours of their initial viewing.

The clips aimed to inoculate against misinformation tactics of hyper-emotive language and use of false dichotomies, and the questions -- based on fictional posts -- tested for detection of these tropes. YouTube also gave a "control" group of users who had not viewed a video the same test question. In total, 22,632 users answered a question.

Despite the intense "noise" and distractions on YouTube, ability to recognise manipulation techniques at the heart of misinformation increased by 5% on average.

Google say the unprecedented nature of the experiment means there is no direct data comparison available. However, increases in brand awareness from advertising on YouTube -- known as "brand lift" -- are typically limited to 1% in surveys of under 45,000 users.

"Users participated in tests around 18 hours on average after watching the videos, so the inoculation appears to have stuck," said van der Linden.

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Fossils of giant sea lizard that ruled the oceans 66 million years ago discovered

Researchers have discovered a huge new mosasaur from Morocco, named Thalassotitan atrox, which filled the apex predator niche. With massive jaws and teeth like those of killer whales, Thalassotitan hunted other marine reptiles -- plesiosaurs, sea turtles, and other mosasaurs.

At the end of the Cretaceous period, 66 million years ago, sea monsters really existed. While dinosaurs flourished on land, the seas were ruled by the mosasaurs, giant marine reptiles.

Mosasaurs weren't dinosaurs, but enormous marine lizards growing up to 12 metres (40 feet) in length. They were distant relatives of modern iguanas and monitor lizards.

Mosasaurs looked like a Komodo dragon with flippers instead of legs, and a shark-like tail fin. Mosasaurs became larger and more specialised in the last 25 million years of the Cretaceous, taking niches once filled by marine reptiles like plesiosaurs and ichthyosaurs. Some evolved to eat small prey like fish and squid. Others crushed ammonites and clams. The new mosasaur, named Thalassotitan atrox, evolved to prey on all the other marine reptiles.

The remains of the new species were dug up in Morocco, about an hour outside Casablanca. Here, near the end of the Cretaceous, the Atlantic flooded northern Africa. Nutrient rich waters upwelling from the depths fed blooms of plankton. Those fed small fish, feeding larger fish, which fed mosasaurs and plesiosaurs -- and so on, with these marine reptiles becoming food for the giant, carnivorous Thalassotitan.

Thalassotitan, had an enormous skull measuring 1.4 metres (5 feet long), and grew to nearly 30 feet (9 metres) long, the size of a killer whale. While most mosasaurs had long jaws and slender teeth for catching fish, Thalassotitan had a short, wide muzzle and massive, conical teeth like those of an orca. These let it seize and rip apart huge prey. These adaptations suggest Thalassotitan was an apex predator, sitting at the top of the food chain. The giant mosasaur occupied the same ecological niche as today's killer whales and great white sharks.

Thalassotitan's teeth are often broken and worn, however eating fish wouldn't have produced this sort of tooth wear. Instead, this suggests that the giant mosasaur attacked other marine reptiles, chipping, breaking, and grinding its teeth as it bit into their bones and tore them apart. Some teeth are so heavily damaged they have been almost ground down to the root.

Fossilised remains of prey

Remarkably, possible remains of Thalassotitan's victims have been discovered. Fossils from the same beds show damage from acids, with teeth and bone eaten away. Fossils with this peculiar damage include large predatory fish, a sea turtle, a half-meter long plesiosaur head, and jaws and skulls of at least three different mosasaur species. They would have been digested in Thalassotitan's stomach before it spat out their bones.

"It's circumstantial evidence," said Dr Nick Longrich, Senior Lecturer from the Milner Centre for Evolution at the University of Bath and lead author on the study, published in Cretaceous Research.

"We can't say for certain which species of animal ate all these other mosasaurs. But we have the bones of marine reptiles killed and eaten by a large predator.

"And in the same location, we find Thalassotitan, a species that fits the profile of the killer -- it's a mosasaur specialised to prey on other marine reptiles. That's probably not a coincidence."

Thalassotitan was a threat to everything in the oceans -- including other Thalassotitan. The huge mosasaurs bear injuries sustained in violent combat with other mosasaurs, with injuries to their face and jaws sustained in fights. Other mosasaurs show similar injuries, but in Thalassotitan these wounds were exceptionally common, suggesting frequent, intense fights over feeding grounds or mates.

"Thalassotitan was an amazing, terrifying animal," said Dr Nick Longrich, who led the study. "Imagine a Komodo Dragon crossed with a great white shark crossed with a T. rex crossed with a killer whale."

The new mosasaur lived in the final million years of the Age of Dinosaurs, a contemporary of animals like T. rex and Triceratops. Along with recent discoveries of mosasaurs from Morocco, it suggests that mosasaurs weren't in decline before the asteroid impact that drove the Cretaceous mass extinction. Instead, they flourished.

Professor Nour-Eddine Jalil, a co-author on the paper from the Museum of Natural History in Paris, said: "The phosphate fossils of Morocco offer an unparalleled window on the paleobiodiversity at the end of Cretaceous.

"They tell us how life was rich and diversified just before the end of the 'dinosaur era', where animals had to specialise to have a place in their ecosystems. Thalassotitan completes the picture by taking on the role of the megapredator at the top of the food chain."

Read more at Science Daily

An extrasolar world covered in water?

An international team of researchers led by Charles Cadieux, a Ph.D. student at the Université de Montréal and member of the Institute for Research on Exoplanets (iREx), has announced the discovery of TOI-1452 b, an exoplanet orbiting one of two small stars in a binary system located in the Draco constellation about 100 light-years from Earth.

The exoplanet is slightly greater in size and mass than Earth and is located at a distance from its star where its temperature would be neither too hot nor too cold for liquid water to exist on its surface. The astronomers believe it could be an "ocean planet," a planet completely covered by a thick layer of water, similar to some of Jupiter's and Saturn's moons.

In an article published today in The Astronomical Journal, Cadieux and his team describe the observations that elucidated the nature and characteristics of this unique exoplanet.

"I'm extremely proud of this discovery because it shows the high calibre of our researchers and instrumentation," said René Doyon, Université de Montréal Professor and Director of iREx and of the Observatoire du Mont-Mégantic (OMM). "It is thanks to the OMM, a special instrument designed in our labs called SPIRou, and an innovative analytic method developed by our research team that we were able to detect this one-of-a-kind exoplanet."

It was NASA's space telescope TESS, which surveys the entire sky in search of planetary systems close to our own, that put the researchers on the trail of this exoplanet. Based on the TESS signal, which showed a slight decrease in brightness every 11 days, astronomers predicted a planet about 70% larger than Earth.

Charles Cadieux belongs to a group of astronomers that does ground follow-up observations of candidates identified by TESS in order to confirm their planet type and characteristics. He uses PESTO, a camera installed on the OMM's telescope that was developed by Université de Montréal Professor David Lafrenière and his Ph.D. student François-René Lachapelle.

"The OMM played a crucial role in confirming the nature of this signal and estimating the planet's radius," explained Cadieux. "This was no routine check. We had to make sure the signal detected by TESS was really caused by an exoplanet circling TOI-1452, the largest of the two stars in that binary system."

The host star TOI-1452 is much smaller than our Sun and is one of two stars of similar size in the binary system. The two stars orbit each other and are separated by such a small distance -- 97 astronomical units, or about two and a half times the distance between the Sun and Pluto -- that the TESS telescope sees them as a single point of light. But PESTO's resolution is high enough to distinguish the two objects, and the images showed that the exoplanet does orbit TOI-1452, which was confirmed through subsequent observations by a Japanese team.

Ingenuity at work

To determine the planet's mass, the researchers then observed the system with SPIRou, an instrument installed on the Canada-France-Hawaii Telescope in Hawai'i. Designed in large part in Canada, SPIRou is ideal for studying low-mass stars such as TOI-1452 because it operates in the infrared spectrum, where these stars are brightest. Even then, it took more than 50 hours of observation to estimate the planet's mass, which is believed to be nearly five times that of Earth.

Researchers Étienne Artigau and Neil Cook, also with iREx at the Université de Montréal, played a key role in analysing the data. They developed a powerful analytic method capable of detecting the planet in the data collected with SPIRou. "The LBL method [for line-by-line] allows us to clean the data obtained with SPIRou of many parasite signals and to reveal the weak signature of planets such as the one discovered by our team," explained Artigau.

The team also includes Quebec researchers Farbod Jahandar and Thomas Vandal, two Ph.D. students at the Université de Montréal. Jahandar analysed the host star's composition, which is useful for constraining the planet's internal structure, while Vandal was involved in analysing the data collected with SPIRou.

A watery world

The exoplanet TOI-1452 b is probably rocky like Earth, but its radius, mass, and density suggest a world very different from our own. Earth is essentially a very dry planet; even though we sometimes call it the Blue Planet because about 70% of its surface is covered by ocean, water actually only makes up a negligible fraction of its mass -- less than 1%.

Water may be much more abundant on some exoplanets. In recent years, astronomers have identified and determined the radius and mass of many exoplanets with a size between that of Earth and Neptune (about 3.8 times larger than Earth). Some of these planets have a density that can only be explained if a large fraction of their mass is made up of lighter materials than those that make up the internal structure of the Earth such as water. These hypothetical worlds have been dubbed "ocean planets."

"TOI-1452 b is one of the best candidates for an ocean planet that we have found to date," said Cadieux. "Its radius and mass suggest a much lower density than what one would expect for a planet that is basically made up of metal and rock, like Earth."

The University of Toronto's Mykhaylo Plotnykov and Diana Valencia are specialists in exoplanet interior modeling. Their analysis of TOI-1452 b shows that water may make up as much as 30% of its mass, a proportion similar to that of some natural satellites in our Solar System, such as Jupiter's moons Ganymede and Callisto, and Saturn's moons Titan and Enceladus.

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Sahelanthropus, the oldest representative of humanity, was indeed bipedal...but that's not all!

The acquisition of bipedalism is considered to be a decisive step in human evolution. Nevertheless, there is no consensus on its modalities and age, notably due to the lack of fossil remains. A research team, involving researchers from the CNRS, the University of Poitiers1 and their Chadian partners, examined three limb bones from the oldest human representative currently identified, Sahelanthropus tchadensis. Published in Nature on August 24, 2022, this study reinforces the idea of bipedalism being acquired very early in our history, at a time still associated with the ability to move on four limbs in trees.

At 7 million years old, Sahelanthropus tchadensis is considered the oldest representative species of humanity. Its description dates back to 2001 when the Franco-Chadian Paleoanthropological Mission (MPFT) discovered the remains of several individuals at Toros-Menalla in the Djurab Desert (Chad), including a very well-preserved cranium. This cranium, and in particular the orientation and anterior position of the occipital foramen where the vertebral column is inserted, indicates a mode of locomotion on two legs, suggesting that it was capable of bipedalism2.

In addition to the cranium, nicknamed Toumaï, and fragments of jaws and teeth that have already been published, the locality of Toros-Menalla 266 (TM 266) yielded two ulnae (forearm bone) and a femur (thigh bone). These bones were also attributed to Sahelanthropus because no other large primate was found at the site; however, it is impossible to know if they belong to the same individual as the cranium. Palaeontologists from the University of Poitiers, the CNRS, the University of N'Djamena and the National Centre of Research for Development (CNRD, Chad) published their complete analysis in Nature on August 24, 2022.

The femur and ulnae were subjected to a battery of measurements and analyses, concerning both their external morphology, and their internal structures using microtomography imaging: biometric measurements, geometric morphometrics, biomechanical indicators, etc. These data were compared to those of a relatively large sample of extant and fossil apes: chimpanzees, gorillas, orangutans, Miocene apes, and members of the human group (Orrorin, Ardipithecus, australopithecines, ancient Homo, Homo sapiens).

The structure of the femur indicates that Sahelanthropus was usually bipedal on the ground, but probably also in trees. According to results from the ulnae, this bipedalism coexisted in arboreal environments with a form of quadrupedalism, that is arboreal clambering enabled by firm hand grips, clearly differing from that of gorillas and chimpanzees who lean on the back of their phalanges.

The conclusions of this study, including the identification of habitual bipedalism, are based on the observation and comparison of more than twenty characteristics of the femur and ulnae. They are, by far, the most parsimonious interpretation of the combination of these traits. All these data reinforce the concept of a very early bipedal locomotion in human history, even if at this stage other modes of locomotion were also practiced.

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Saturn V was loud but didn't melt concrete

The Saturn V carried man to the moon and remains the most powerful rocket to successfully launch to orbit. It captures the imagination -- but sometimes, it might capture a bit too much imagination. Abundant internet claims about the acoustic power of the rocket suggest that it melted concrete and lit grass on fire over a mile away.

Such ideas are undeniably false. In The Journal of the Acoustical Society of America, published on behalf of the Acoustical Society of America by AIP Publishing, researchers from Brigham Young University used a physics-based model to estimate the acoustic levels of the Saturn V. They obtained a value of 203 decibels, which matched the very limited data from the 1960s.

To put that number into perspective, commercial jet engines range from around 120 to 160 decibels.

"Decibels are logarithmic, so every 10 decibels is an order of magnitude increase," said author Kent L. Gee, of BYU. "One hundred and seventy decibels would be equivalent to 10 aircraft engines. Two hundred would be 10,000 engines!"

While the Saturn V was extremely loud, that kind of power is nowhere near enough to melt concrete or start grass fires. If reports about these phenomena are true, they likely stem from radiative heating via the plume or debris.

Some of the misunderstanding comes from confusing sound power with sound pressure. The former is like the wattage from a light bulb. The latter is like the brightness from the same bulb: It depends on how far away you're standing. Mistakes in calculations, changes to the decibel reference system, and the propagation of misinformation have also led to compounding errors.

"The Saturn V has taken on this sort of legendary, apocryphal status," said Gee. "We felt that, as part of the JASA special issue on Education in Acoustics, it was an opportunity to correct misinformation about this vehicle."

NASA's Space Launch System (SLS) Artemis 1 launch is scheduled for the fall of this year, when it will send humans back to the moon and surpass the Saturn V in terms of power and noise. The researchers have used their framework to predict SLS's sound levels, and they plan to make acoustical measurements at its launch to help to further refine predictions.

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Sleepless and selfish: Lack of sleep makes us less generous

Humans help each other -- it's one of the foundations of civilized society. But a new study by scientists at the University of California, Berkeley, reveals that a lack of sleep blunts this fundamental human attribute, with real-world consequences.

Lack of sleep is known to be associated with an increased risk of cardiovascular disease, depression, diabetes, hypertension and overall mortality. However, these new discoveries show that a lack of sleep also impairs our basic social conscience, making us withdraw our desire and willingness to help other people.

In one portion of the new study, the scientists showed that charitable giving in the week after the beginning of Daylight Saving Time, when residents of most states "spring forward" and lose one hour of their day, dropped by 10% -- a decrease not seen in states that do not change their clocks or when states return to standard time in the fall.

The study, led by UC Berkeley research scientist Eti Ben Simon and Matthew Walker, a UC Berkeley professor of psychology, adds to a growing body of evidence demonstrating that inadequate sleep not only harms the mental and physical well-being of an individual, but also compromises the bonds between individuals -- and even the altruistic sentiment of an entire nation.

"Over the past 20 years, we have discovered a very intimate link between our sleep health and our mental health. Indeed, we've not been able to discover a single major psychiatric condition in which sleep is normal," Walker said. "But this new work demonstrates that a lack of sleep not only damages the health of an individual, but degrades social interactions between individuals and, furthermore, degrades the very fabric of human society itself. How we operate as a social species -- and we are a social species -- seems profoundly dependent on how much sleep we are getting."

"We're starting to see more and more studies, including this one, where the effects of sleep loss don't just stop at the individual, but propagate to those around us," said Ben Simon. "If you're not getting enough sleep, it doesn't just hurt your own well-being, it hurts the well-being of your entire social circle, including strangers."

Ben Simon, Walker and colleagues Raphael Vallat and Aubrey Rossi will publish their results August 23 in the open access journal PLOS Biology. Walker is the director of the Center for Human Sleep Science. He and Ben Simon are members of the Helen Wills Neuroscience Institute at UC Berkeley.

Sleeplessness dampens theory of mind network

The new report describes three separate studies that assessed the impact of sleep loss on people's willingness to help others. In the first study, the scientists placed 24 healthy volunteers in a functional magnetic resonance imager (fMRI) to scan their brains after eight hours of sleep and after a night of no sleep. They found that areas of the brain that form the theory of mind network, which is engaged when people empathize with others or try to understand other people's wants and needs, were less active after a sleepless night.

"When we think about other people, this network engages and allows us to comprehend what other person's needs are: What are they thinking about? Are they in pain? Do they need help?" Ben Simon said. "However, this network was markedly impaired when individuals were sleep deprived. It's as though these parts of the brain fail to respond when we are trying to interact with other people after not getting enough sleep."

In a second study, they tracked more than 100 people online over three or four nights. During this time, the researchers measured the quality of their sleep -- how long they slept, how many times they woke up -- and then assessed their desire to help others, such as holding an elevator door open for someone else, volunteering or helping an injured stranger on the street.

"Here, we found that a decrease in the quality of someone's sleep from one night to the next predicted a significant decrease in the desire to help other people from one subsequent day to the next," Ben Simon said. "Those with poor sleep the night prior were the ones that reported being less willing and keen to help others the following day."

The third part of the study involved mining a database of 3 million charitable donations in the United States between 2001 and 2016. Did the number of donations change after the transition to Daylight Saving Time and the potential loss of an hour of sleep? They found a 10% drop in donations. This same dent in compassionate gift-giving was not seen in regions of the country that did not change their clocks.

"Even a very modest 'dose' of sleep deprivation -- here, just the loss of one single hour of sleep opportunity linked to daylight saving time -- has a very measurable and very real impact on people's generosity and, therefore, how we function as a connected society," Walker said. "When people lose one hour of sleep, there's a clear hit on our innate human kindness and our motivation to help other people in need."

An earlier study by Walker and Ben Simon showed that sleep deprivation forced people to socially withdraw and become more socially isolated. A lack of sleep also increased their feelings of loneliness. Worse still, when those sleep-deprived individuals interacted with other people, they spread their loneliness to those other individuals, almost like a virus, Walker said.

"Looking at the big picture, we're starting to see that a lack of sleep results in a quite asocial and, from a helping perspective, anti-social individual, which has manifold consequences to how we live together as a social species," he said. "A lack of sleep makes people less empathetic, less generous, more socially withdrawn, and it's infectious -- there is contagion of loneliness."

"The realization that the quantity and quality of sleep affects an entire society, caused by an impairment in prosocial behavior, may provide insights into our societal state of affairs in the present day," Walker added.

This finding also offers a novel approach to improving these specific aspects of our society.

"Promoting sleep, rather than shaming people for sleeping enough, could very palpably help shape the social bonds we all experience every day," Ben Simon said.

"Sleep, it turns out, is an incredible lubricant to prosocial, connected, empathic, kind and generous human behavior. In these divisive times, if there was ever a need for a strong, prosocial lubricant to enable the very best version of ourselves within society, now seems to be it," said Walker, author of the international bestseller, Why We Sleep. "Sleep may be a wonderful ingredient that enables the alacrity of helping between human beings."

"Sleep is essential for all aspects of our physical, mental and emotional lives," Ben Simon said. "When sleep is undervalued in society, not only do we get sleep-deprived doctors, nurses and students, but we also suffer from unkind and less empathic interactions on a daily basis."

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A prehistoric climate feedback loop

Against the backdrop of a rapidly warming planet, the need to better understand the nature and long-term impact of positive climatic feedback loops -- processes that accelerate the effects of warming -- becomes critically important.

One way to assess the role and impact of climatic feedback processes is to use modeling studies to look into the likely future based on what we know now. Climate projection models, for instance, are the tools behind the 1.5° C global warming threshold adopted by the Intergovernmental Panel on Climate Change.

Alternatively, you can look into the past to see what happened at a time when the Earth was up to 1-1.5°C warmer than today. That is what UC Santa Barbara's Syee Weldeab did in a paper published in the Proceedings of the National Academy of Sciences. The professor of paleoclimatology found feedback processes that have concerning implications for our modern, ongoing warming.

To get a paleoclimate perspective on global warming, Weldeab and his colleagues went back some 128,000 to 125,000 years ago to the peak Eemian warm episode. Oceans were up to 1-1.5°C warmer than during the Holocene (our current geological epoch). The authors examined marine sediment from the tropical Atlantic and found exceptionally strong warming of the intermediate water column during a brief interval within the peak Eemian warm episode.

"Remarkably, a substantially diminished Greenland Ice Sheet was capable of producing enough meltwater to perturb the density-driven circulation of the Atlantic Ocean," Weldeab said. "This contributed significantly to the large warming of the intermediate waters we reconstructed."

Typically, warm, salty water travels north from the tropics along the surface of the ocean and cools as it reaches northern mid and high latitudes. At this point, the now colder, denser water drops to the deep sea and travels back down toward the tropics. This interplay of density differences results in the currents that we're familiar with today.

"What happens when you put a large amount of fresh water into the North Atlantic is basically it disturbs ocean circulation and reduces the advection of cold water into the intermediate depth of the tropical Atlantic, and as a result warms the waters at this depth," he said.

While previous studies have discussed the disruption that meltwater caused to currents and temperatures at intermediate depths, the new paper reveals that this warming was "larger than previously thought."

"We show a hitherto undocumented and remarkably large warming of water at intermediate depths, exhibiting a temperature increase of 6.7°C from the average background value," Weldeab said.

This exceptionally strong warming has serious consequences. As the warm water impinges on marine sediment that contains abundant methane hydrates -- a mixture of frozen water and methane. These deposits are not far below the surface of the seafloor.

Weldeab explained that at high pressure and low temperatures, the introduction of unusually warm water heats the seafloor sediment, and the ice-encapsulated gases begin to dissolve, releasing methane. Weldeab and colleagues used carbon isotopes (13C/12C) in the shells of microorganisms to uncover the fingerprint of methane release and methane oxidation across the water column.

"This is one of several amplifying climatic feedback processes where a warming climate caused accelerated ice sheet melting," he said. "The meltwater weakened the ocean circulation and, as a consequence, the waters at intermediate depth warmed significantly, leading to destabilization of shallow subsurface methane hydrates and release of methane, a potent greenhouse gas."

It is not known for sure whether this feedback cycle will play out in the current round of global warming, though anthropogenic activity has created a higher rate of warming than the one that occurred in the Eemian period. These findings, according to the researchers, "document and connects a sequence of climatic events and climatic feedback processes associated with and triggered by the penultimate peak climate warming that can serve as a paleo-analogue for modern ongoing warming."

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Study of ancient skulls sheds light on human interbreeding with Neanderthals

Research has established that there are traces of Neandertal DNA in the genome of modern humans. Now an exploratory study that assessed the facial structure of prehistoric skulls is offering new insights, and supports the hypothesis that much of this interbreeding took place in the Near East -- the region ranging from North Africa to Iraq.

"Ancient DNA caused a revolution in how we think about human evolution," says Steven Churchill, co-author of the study and a professor of evolutionary anthropology at Duke University. "We often think of evolution as branches on a tree, and researchers have spent a lot of time trying to trace back the path that led to us, Homo sapiens. But we're now beginning to understand that it isn't a tree -- it's more like a series of streams that converge and diverge at multiple points."

"Our work here gives us a deeper understanding of where those streams came together," says Ann Ross, corresponding author of the study and a professor of biological sciences at North Carolina State University.

"The picture is really complicated," Churchill says. "We know there was interbreeding. Modern Asian populations seem to have more Neandertal DNA than modern European populations, which is weird -- because Neandertals lived in what is now Europe. That has suggested that Neandertals interbred with what are now modern humans as our prehistoric ancestors left Africa, but before spreading to Asia. Our goal with this study was to see what additional light we could shed on this by assessing the facial structure of prehistoric humans and Neandertals."

"By evaluating facial morphology, we can trace how populations moved and interacted over time," Ross explains. "And the evidence shows us that the Near East was an important crossroads, both geographically and in the context of human evolution."

For this study, the researchers collected data on craniofacial morphology from the published literature. This ultimately resulted in a data set including 13 Neandertals, 233 prehistoric Homo sapiens, and 83 modern humans.

The researchers focused on standard craniofacial measurements, which are reproducible, and used those measurements to assess the size and shape of key facial structures. This then allowed the researchers to do an in-depth analysis to determine whether a given human population was likely to have interbred with Neandertal populations, as well as the extent of that likely interbreeding.

"Neandertals had big faces," Churchill says. "But size alone doesn't establish any genetic link between a human population and Neandertal populations. Our work here involved a more robust analysis of the facial structures."

The researchers also accounted for environmental variables that are associated with changes in human facial characteristics, to determine the likelihood that connections they established between Neandertal and human populations were the result of interbreeding rather than other factors.

"We found that the facial characteristics we focused on were not strongly influenced by climate, which made it easier to identify likely genetic influences," Ross says. "We also found that facial shape was a more useful variable for tracking the influence of Neandertal interbreeding in human populations over time. Neandertals were just bigger than humans. Over time, the size of human faces became smaller, generations after they had bred with Neandertals. But the actual shape of some facial features retained evidence of interbreeding with Neandertals."

"This was an exploratory study," Churchill says. "And, honestly, I wasn't sure this approach would actually work -- we have a relatively small sample size, and we didn't have as much data on facial structures as we would have liked. But, ultimately, the results we got are really compelling.

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People with similar faces likely have similar DNA

A collection of photos of genetically unrelated lookalikes, along with DNA analysis, revealed that strong facial similarity is associated with shared genetic variants. The work appears August 23rd in the journal Cell Reports.

"Our study provides a rare insight into human likeness by showing that people with extreme lookalike faces share common genotypes, whereas they are discordant at the epigenome and microbiome levels," says senior author Manel Esteller of the Josep Carreras Leukaemia Research Institute in Barcelona, Spain. "Genomics clusters them together, and the rest sets them apart."

The number of people identified online as virtual twins or doubles who are genetically unrelated has increased due to the expansion of the World Wide Web and the possibility of exchanging pictures of humans across the planet. In the new study, Esteller and his team set out to characterize, on a molecular level, random human beings that objectively share facial features.

To do so, they recruited human doubles from the photographic work of François Brunelle, a Canadian artist who has been obtaining worldwide pictures of lookalikes since 1999. They obtained headshot pictures of 32 lookalike couples. The researchers determined an objective measure of likeness for the pairs using three different facial recognition algorithms.

In addition, the participants completed a comprehensive biometric and lifestyle questionnaire and provided saliva DNA for multiomics analysis. "This unique set of samples has allowed us to study how genomics, epigenomics, and microbiomics can contribute to human resemblance," Esteller says.

Overall, the results revealed that these individuals share similar genotypes, but differ in their DNA methylation and microbiome landscapes. Half of the lookalike pairs were clustered together by all three algorithms. Genetic analysis revealed that 9 of these 16 pairs clustered together, based on 19,277 common single-nucleotide polymorphisms.

Moreover, physical traits such as weight and height, as well as behavioral traits such as smoking and education, were correlated in lookalike pairs. Taken together, the results suggest that shared genetic variation not only relates to similar physical appearance, but may also influence common habits and behavior.

"We provided a unique insight into the molecular characteristics that potentially influence the construction of the human face," Esteller says. "We suggest that these same determinants correlate with both physical and behavioral attributes that constitute human beings."

A few study limitations include the small sample size, the use of 2D black-and-white images, and the predominance of European participants. Despite these caveats, the findings may provide a molecular basis for future applications in various fields such as biomedicine, evolution, and forensics.

"These results will have future implications in forensic medicine -- reconstructing the criminal's face from DNA -- and in genetic diagnosis -- the photo of the patient's face will already give you clues as to which genome he or she has," Esteller says. "Through collaborative efforts, the ultimate challenge would be to predict the human face structure based on the individual's multiomics landscape."

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Brains cells born together wire and fire together for life

Brain cells with the same "birthdate" are more likely to wire together into cooperative signaling circuits that carry out many functions, including the storage of memories, a new study finds.

Led by researchers from NYU Grossman School of Medicine, the new study on the brains of mice developing in the womb found that brain cells (neurons) with the same birthdate showed distinct connectivity and activity throughout the animals' adult lives, whether they were asleep or awake.

Published online August 22 in Nature Neuroscience, the findings suggest that evolution took advantage of the orderly birth of neurons -- by gestational day -- to form localized microcircuits in the hippocampus, the brain region that forms memories. Rather than attempting to create each new memory from scratch, the researchers suggest, the brain may exploit the stepwise formation of neuronal layers to establish neural templates, like "Lego pieces," that match each new experience to an existing template as it is remembered.

These rules of circuit assembly would suggest that cells born together are more likely to encode memories together, and to fail together, potentially implicating neuronal birthdate in diseases like autism and Alzheimer's, say the authors. With changes to the number of cells born at different days, the developing brain may be more vulnerable on some gestational days to viral infections, toxins, or alcohol.

"Our study's results suggest that which day a hippocampal neuron is born strongly influences both how that single cell performs, and how populations of such cells signal together throughout life," says senior study author György Buzsáki, MD, PhD, the Biggs Professor in the Department of Neuroscience and Physiology at NYU Langone Health. "This work may reshape how we study neurodevelopmental disorders, which have traditionally been looked at through a molecular or genetic, rather than a developmental, lens," says Buzsáki, also a faculty member in the Neuroscience Institute at NYU Langone."

New Understanding

The current study's innovation rests on tracking the activity of neurons of a given birthdate into adulthood. To accomplish this, the researchers relied on a technique that allowed them to transfer DNA into cells that were undergoing division into neurons in the womb. The DNA expressed markers that tagged brain cells that were born on same day, akin to a barcode. This labeling method then enabled the researchers to study these neurons in the adult animal.

Using a combination of techniques, the new study found that neurons of the same birthdate tend to "co-fire" together, characterized by synchronized swings in their positive and negative charges, allowing them to transmit electrical signals collectively. A likely reason for the co-firing, say the authors, is that neurons with the same birthdate are connected via shared neurons.

Past work had shown that activity in the hippocampus can be described in terms patterns of collective neuronal activity during waking and sleep. During sleep, for instance, when each day's memories are consolidated for long-term memory storage, hippocampal neurons engage in a cyclical burst of activity called the "sharp wave-ripple," named for the shape it takes when captured graphically by EEG, a technology that records brain activity with electrodes.

"Our results show that neurons born on the same day become part of the same cooperating assemblies, and participate in the same sharp wave-ripples and represent the same memories," says first author Roman Huszár, a graduate student in Buzsáki's lab. "These relationships, and the pre-set templates they encode, have a key implication for hippocampal function: the storage of a memory about a place or event."

Moving forward, the team plans additional experiments to identify the genes active in the same birthdate neurons in different brain regions, and to test their role in memory formation and behavior.

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Seeing universe's most massive known star

By harnessing the capabilities of the 8.1-meter Gemini South telescope in Chile, which is part of the International Gemini Observatory operated by NSF's NOIRLab, astronomers have obtained the sharpest image ever of the star R136a1, the most massive known star in the Universe. Their research, led by NOIRLab astronomer Venu M. Kalari, challenges our understanding of the most massive stars and suggests that they may not be as massive as previously thought.

Astronomers have yet to fully understand how the most massive stars -- those more than 100 times the mass of the Sun -- are formed. One particularly challenging piece of this puzzle is obtaining observations of these giants, which typically dwell in the densely populated hearts of dust-shrouded star clusters. Giant stars also live fast and die young, burning through their fuel reserves in only a few million years. In comparison, our Sun is less than halfway through its 10 billion year lifespan. The combination of densely packed stars, relatively short lifetimes, and vast astronomical distances makes distinguishing individual massive stars in clusters a daunting technical challenge.

By pushing the capabilities of the Zorro instrument on the Gemini South telescope of the International Gemini Observatory, operated by NSF's NOIRLab, astronomers have obtained the sharpest-ever image of R136a1 -- the most massive known star. This colossal star is a member of the R136 star cluster, which lies about 160,000 light-years from Earth in the center of the Tarantula Nebula in the Large Magellanic Cloud, a dwarf companion galaxy of the Milky Way.

Previous observations suggested that R136a1 had a mass somewhere between 250 to 320 times the mass of the Sun. The new Zorro observations, however, indicate that this giant star may be only 170 to 230 times the mass of the Sun. Even with this lower estimate, R136a1 still qualifies as the most massive known star.

Astronomers are able to estimate a star's mass by comparing its observed brightness and temperature with theoretical predictions. The sharper Zorro image allowed NSF's NOIRLab astronomer Venu M. Kalari and his colleagues to more accurately separated the brightness of R136a1 from its nearby stellar companions, which led to a lower estimate of its brightness and therefore its mass.

"Our results show us that the most massive star we currently know is not as massive as we had previously thought," explained Kalari, lead author of the paper announcing this result. "This suggests that the upper limit on stellar masses may also be smaller than previously thought."

This result also has implications for the origin of elements heavier than helium in the Universe. These elements are created during the cataclysmicly explosive death of stars more than 150 times the mass of the Sun in events that astronomers refer to as pair-instability supernovae. If R136a1 is less massive than previously thought, the same could be true of other massive stars and consequently pair instability supernovae may be rarer than expected.

The star cluster hosting R136a1 has previously been observed by astronomers using the NASA/ESA Hubble Space Telescope and a variety of ground-based telescopes, but none of these telescopes could obtain images sharp enough to pick out all the individual stellar members of the nearby cluster.

Gemini South's Zorro instrument was able to surpass the resolution of previous observations by using a technique known as speckle imaging, which enables ground-based telescopes to overcome much of the blurring effect of Earth's atmosphere. By taking many thousands of short-exposure images of a bright object and carefully processing the data, it is possible to cancel out almost all this blurring. This approach, as well as the use of adaptive optics, can dramatically increase the resolution of ground-based telescopes, as shown by the team's sharp new Zorro observations of R136a1.

"This result shows that given the right conditions an 8.1-meter telescope pushed to its limits can rival not only the Hubble Space Telescope when it comes to angular resolution, but also the James Webb Space Telescope," commented Ricardo Salinas, a co-author of this paper and the instrument scientist for Zorro. "This observation pushes the boundary of what is considered possible using speckle imaging."

"We began this work as an exploratory observation to see how well Zorro could observe this type of object," concluded Kalari. "While we urge caution when interpreting our results, our observations indicate that the most massive stars may not be as massive as once thought."

Zorro and its twin instrument `Alopeke are identical imagers mounted on the Gemini South and Gemini North telescopes, respectively. Their names are the Hawaiian and Spanish words for "fox" and represent the telescopes' respective locations on Maunakea in Hawai'i and on Cerro Pachón in Chile. These instruments are part of the Gemini Observatory's Visiting Instrument Program, which enables new science by accommodating innovative instruments and enabling exciting research. Steve B. Howell, current chair of the Gemini Observatory Board and senior research scientist at the NASA Ames Research Center in Mountain View, California, is the principal investigator on both instruments.

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Medieval monks were 'riddled with parasites'

A new analysis of remains from medieval Cambridge shows that local Augustinian friars were almost twice as likely as the city's general population to be infected by intestinal parasites.

This is despite most Augustinian monasteries of the period having latrine blocks and hand-washing facilities, unlike the houses of ordinary working people.

Researchers from the University of Cambridge's Department of Archaeology say the difference in parasitic infection may be down to monks manuring crops in friary gardens with their own faeces, or purchasing fertiliser containing human or pig excrement.

The study, published today in the International Journal of Paleopathology, is the first to compare parasite prevalence in people from the same medieval community who were living different lifestyles, and so might have differed in their infection risk.

The population of medieval Cambridge consisted of residents of monasteries, friaries and nunneries of various major Christian orders, along with merchants, traders, craftsmen, labourers, farmers, and staff and students at the early university.

Cambridge archaeologists investigated samples of soil taken from around the pelvises of adult remains from the former cemetery of All Saints by the Castle parish church, as well as from the grounds where the city's Augustinian Friary once stood.

Most of the parish church burials date from the 12-14th century, and those interred within were primarily of a lower socio-economic status, mainly agricultural workers.

The Augustinian friary in Cambridge was an international study house, known as a studium generale, where clergy from across Britain and Europe would come to read manuscripts. It was founded in the 1280s and lasted until 1538 before suffering the fate of most English monasteries: closed or destroyed as part of Henry VIII's break with the Roman Church.

The researchers tested 19 monks from the friary grounds and 25 locals from All Saints cemetery, and found that 11 of the friars (58%) were infected by worms, compared with just eight of the general townspeople (32%).

They say these rates are likely the minimum, and that actual numbers of infections would have been higher, but some traces of worm eggs in the pelvic sediment would have been destroyed over time by fungi and insects.

The 32% prevalence of parasites among townspeople is in line with studies of medieval burials in other European countries, suggesting this is not particularly low -- but rather the infection rates in the monastery were remarkably high.

"The friars of medieval Cambridge appear to have been riddled with parasites," said study lead author Dr Piers Mitchell from Cambridge's Department of Archaeology. "This is the first time anyone has attempted to work out how common parasites were in people following different lifestyles in the same medieval town."

Cambridge researcher Tianyi Wang, who did the microscopy to spot the parasite eggs, said: "Roundworm was the most common infection, but we found evidence for whipworm infection as well. These are both spread by poor sanitation."

Standard sanitation in medieval towns relied on the cesspit toilet: holes in the ground used for faeces and household waste. In monasteries, however, running water systems were a common feature -- including to rinse out the latrine -- although that has yet to be confirmed at the Cambridge site, which is only partly excavated.

Not all people buried in Augustinian friaries were actually clergy, as wealthy people from the town could pay to be interred there. However, the team could tell which graves belonged to friars from the remains of their clothing.

"The friars were buried wearing the belts they wore as standard clothing of the order, and we could see the metal buckles at excavation," said co-author Craig Cessford of the Cambridge Archaeological Unit.

As roundworm and whipworm are spread by poor sanitation, researchers argue that the difference in infection rates between the friars and the general population must have been due to how each group dealt with their human waste.

"One possibility is that the friars manured their vegetable gardens with human faeces, not unusual in the medieval period, and this may have led to repeated infection with the worms," said Mitchell.

Medieval records reveal how Cambridge residents may have understood parasites such as roundworm and whipworm. John Stockton, a medical practitioner in Cambridge who died in 1361, left a manuscript to Peterhouse college that included a section on De Lumbricis ('on worms').

It notes that intestinal worms are generated by excess of various kinds of phlegm: "Long round worms form from an excess of salt phlegm, short round worms from sour phlegm, while short and broad worms came from natural or sweet phlegm."

The text prescribes "bitter medicinal plants" such as aloe and wormwood, but recommends they are disguised with "honey or other sweet things" to help the medicine go down.

Another text -- Tabula medicine -- found favour with leading Cambridge doctors of the 15th century, and suggests remedies as recommended by individual Franciscan monks, such as Symon Welles, who advocated mixing a powder made from moles into a curative drink.

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Wave created by Tonga volcano eruption reached 90 meters -- nine times taller than 2011 Japan tsunami

The initial tsunami wave created by the eruption of the underwater Hunga Tonga Ha'apai volcano in Tonga in January 2022 reached 90 metres in height, around nine times taller than that from the highly destructive 2011 Japan tsunami, new research has found.

An international research team says the eruption should serve as a wake-up call for international groups looking to protect people from similar events in future, claiming that detection and monitoring systems for volcano-based tsunamis are '30 years behind' comparable tools used to detect earthquake-based events.

Dr Mohammad Heidarzadeh, Secretary-General of the International Tsunami Commission and a senior lecturer in the University of Bath's Department of Architecture & Civil Engineering, authored the research alongside colleagues based in Japan, New Zealand, the UK and Croatia.

By comparison, the largest tsunami waves due to earthquakes before the Tonga event were recorded following the Tōhoku earthquake near Japan in 2011 and the 1960 Chilean earthquake, reached 10 metres in initial height. Those were more destructive as they happened closer to land, with waves that were wider.

Dr Heidarzadeh says the Tonga tsunami should serve as a wake-up call for more preparedness and understanding of the causes and signs of tsunamis cause by volcanic eruptions. He says: "The Tongan tsunami tragically killed five people and caused large scale destruction, but its effects could have been even greater had the volcano been located closer to human communities. The volcano is located approximately 70 km from the Tongan capital Nuku'alofa -- this distance significantly minimized its destructive power.

"This was a gigantic, unique event and one that highlights that internationally we must invest in improving systems to detect volcanic tsunamis as these are currently around 30 years behind the systems we used to monitor for earthquakes. We are under-prepared for volcanic tsunamis."

The research was carried out by analysing ocean observation data recordings of atmospheric pressure changes and sea level oscillations, in combination with computer simulations validated with real-world data.

The research team found that the tsunami was unique as the waves were created not only by the water displaced by the volcano's eruption, but also by huge atmospheric pressure waves, which circled around the globe multiple times. This 'dual mechanism' created a two-part tsunami -- where initial ocean waves created by the atmospheric pressure waves were followed more than one hour later by a second surge created by the eruption's water displacement.

This combination meant tsunami warning centres did not detect the initial wave as they are programmed to detect tsunamis based on water displacements rather than atmospheric pressure waves.

The research team also found that the January event was among very few tsunamis powerful enough to travel around the globe -- it was recorded in all world's oceans and large seas from Japan and the United States' western seaboard in the North Pacific Ocean to the coasts within the Mediterranean Sea.

The paper, co-authored by colleagues from New Zealand's GNS Science, the Association for the Development of Earthquake Prediction in Japan, the University of Split in Croatia and at London's Brunel University, was published this week in Ocean Engineering.

Dr Aditya Gusman, Tsunami Modeller at the New Zealand-based geoscience service, says: "The 2018 Anak Krakatau volcano and 2022 Hunga Tonga-Hunga Ha'apai volcano eruptions clearly showed us that coastal areas surrounding volcano islands are at risk of being hit by destructive tsunamis. Although it may be preferable to have low-lying coastal areas completely clear from residential buildings, such a policy may not be practical for some places as volcanic tsunamis can be considered infrequent events."

Co-author Dr Jadranka Šepić, from the University of Split, Croatia, adds: "What is important is to have efficient warning systems, which include both real-time warnings and education on what to do in a case of a tsunami or warning -- such systems save lives. In addition, at volcanic areas, monitoring of volcanic activity should be organized, and more high-quality research into volcanic eruptions and areas at hazard is always a good idea."

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New model for predicting belief change

A new kind of predictive network model could help determine which people will change their minds about contentious scientific issues when presented with evidence-based information.

A study in Science Advances presents a framework to accurately predict if a person will change their opinion about a certain topic. The approach estimates the amount of dissonance, or mental discomfort, a person has from holding conflicting beliefs about a topic.

Santa Fe Institute Postdoctoral Fellows Jonas Dalege and Tamara van der Does built on previous efforts to model belief change by integrating both moral and social beliefs into a statistical physics framework of 20 interacting beliefs.

They then used this cognitive network model to predict how the beliefs of a group of nearly 1,000 people, who were at least somewhat skeptical about the efficacy of genetically modified foods and childhood vaccines, would change as the result of an educational intervention.

Study participants were shown a message about the scientific consensus on genetic modification and vaccines. Those who began the study with a lot of dissonance in their interwoven network of beliefs were more likely to change their beliefs after viewing the messaging, but not necessarily in accordance with the message. On the other hand, people with little dissonance showed little change following the intervention.

"For example, if you believe that scientists are inherently trustworthy, but your family and friends tell you that vaccines are unsafe, this is going to create some dissonance in your mind," van der Does says. "We found that if you were already kind of anti-GM foods or vaccines to begin with, you would just move more towards that direction when presented with new information even if that wasn't the intention of the intervention."

While still in an early stage, the research could ultimately have important implications for communicating scientific, evidence-based information to the public.

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