Real-time wearable human emotion recognition technology developed

A groundbreaking technology that can recognize human emotions in real time has been developed by Professor Jiyun Kim and his research team in the Department of Material Science and Engineering at UNIST. This innovative technology is poised to revolutionize various industries, including next-generation wearable systems that provide services based on emotions.

Understanding and accurately extracting emotional information has long been a challenge due to the abstract and ambiguous nature of human affects such as emotions, moods, and feelings.

To address this, the research team has developed a multi-modal human emotion recognition system that combines verbal and non-verbal expression data to efficiently utilize comprehensive emotional information.

At the core of this system is the personalized skin-integrated facial interface (PSiFI) system, which is self-powered, facile, stretchable, and transparent.

It features a first-of-its-kind bidirectional triboelectric strain and vibration sensor that enables the simultaneous sensing and integration of verbal and non-verbal expression data.

The system is fully integrated with a data processing circuit for wireless data transfer, enabling real-time emotion recognition.

Utilizing machine learning algorithms, the developed technology demonstrates accurate and real-time human emotion recognition tasks, even when individuals are wearing masks.

The system has also been successfully applied in a digital concierge application within a virtual reality (VR) environment.

The technology is based on the phenomenon of "friction charging," where objects separate into positive and negative charges upon friction.

Notably, the system is self-generating, requiring no external power source or complex measuring devices for data recognition.

Professor Kim commented, "Based on these technologies, we have developed a skin-integrated face interface (PSiFI) system that can be customized for individuals." The team utilized a semi-curing technique to manufacture a transparent conductor for the friction charging electrodes.

Additionally, a personalized mask was created using a multi-angle shooting technique, combining flexibility, elasticity, and transparency.

The research team successfully integrated the detection of facial muscle deformation and vocal cord vibrations, enabling real-time emotion recognition.

The system's capabilities were demonstrated in a virtual reality "digital concierge" application, where customized services based on users' emotions were provided.

Jin Pyo Lee, the first author of the study, stated, "With this developed system, it is possible to implement real-time emotion recognition with just a few learning steps and without complex measurement equipment. This opens up possibilities for portable emotion recognition devices and next-generation emotion-based digital platform services in the future."

The research team conducted real-time emotion recognition experiments, collecting multimodal data such as facial muscle deformation and voice.

The system exhibited high emotional recognition accuracy with minimal training.

Its wireless and customizable nature ensures wearability and convenience.

Furthermore, the team applied the system to VR environments, utilizing it as a "digital concierge" for various settings, including smart homes, private movie theaters, and smart offices.

The system's ability to identify individual emotions in different situations enables the provision of personalized recommendations for music, movies, and books.

Professor Kim emphasized, "For effective interaction between humans and machines, human-machine interface (HMI) devices must be capable of collecting diverse data types and handling complex integrated information. This study exemplifies the potential of using emotions, which are complex forms of human information, in next-generation wearable systems."

Read more at Science Daily

Brightest and fastest-growing: Astronomers identify record-breaking quasar

Using the European Southern Observatory's (ESO) Very Large Telescope (VLT), astronomers have characterised a bright quasar, finding it to be not only the brightest of its kind, but also the most luminous object ever observed. Quasars are the bright cores of distant galaxies and they are powered by supermassive black holes. The black hole in this record-breaking quasar is growing in mass by the equivalent of one Sun per day, making it the fastest-growing black hole to date.

The black holes powering quasars collect matter from their surroundings in a process so energetic that it emits vast amounts of light.

So much so that quasars are some of the brightest objects in our sky, meaning even distant ones are visible from Earth.

As a general rule, the most luminous quasars indicate the fastest-growing supermassive black holes.

"We have discovered the fastest-growing black hole known to date. It has a mass of 17 billion Suns, and eats just over a Sun per day. This makes it the most luminous object in the known Universe," says Christian Wolf, an astronomer at the Australian National University (ANU) and lead author of the study published today in Nature Astronomy. The quasar, called J0529-4351, is so far away from Earth that its light took over 12 billion years to reach us.

The matter being pulled in toward this black hole, in the form of a disc, emits so much energy that J0529-4351 is over 500 trillion times more luminous than the Sun.

"All this light comes from a hot accretion disc that measures seven light-years in diameter -- this must be the largest accretion disc in the Universe," says ANU PhD student and co-author Samuel Lai.

Seven light-years is about 15,000 times the distance from the Sun to the orbit of Neptune.

And, remarkably, this record-breaking quasar was hiding in plain sight.

"It is a surprise that it has remained unknown until today, when we already know about a million less impressive quasars. It has literally been staring us in the face until now," says co-author Christopher Onken, an astronomer at ANU.

He added that this object showed up in images from the ESO Schmidt Southern Sky Survey dating back to 1980, but it was not recognised as a quasar until decades later.

Finding quasars requires precise observational data from large areas of the sky.

The resulting datasets are so large, researchers often use machine-learning models to analyse them and tell quasars apart from other celestial objects.

However, these models are trained on existing data, which limits the potential candidates to objects similar to those already known.

If a new quasar is more luminous than any other previously observed, the programme might reject it and classify it instead as a star not too distant from Earth.

An automated analysis of data from the European Space Agency's Gaia satellite passed over J0529-4351 for being too bright to be a quasar, suggesting it to be a star instead.

The researchers identified it as a distant quasar last year using observations from the ANU 2.3-metre telescope at the Siding Spring Observatory in Australia.

Discovering that it was the most luminous quasar ever observed, however, required a larger telescope and measurements from a more precise instrument.

The X-shooter spectrograph on ESO's VLT in the Chilean Atacama Desert provided the crucial data.

The fastest-growing black hole ever observed will also be a perfect target for the GRAVITY+ upgrade on ESO's VLT Interferometer (VLTI), which is designed to accurately measure the mass of black holes, including those far away from Earth.

Additionally, ESO's Extremely Large Telescope (ELT), a 39-metre telescope under construction in the Chilean Atacama Desert, will make identifying and characterising such elusive objects even more feasible.

Read more at Science Daily

Cooler, wetter parts of Pacific Northwest likely to see more fires, new simulations predict

Forests in the coolest, wettest parts of the western Pacific Northwest are likely to see the biggest increases in burn probability, fire size and number of blazes as the climate continues to get warmer and drier, according to new modeling led by an Oregon State University scientist.

Understanding how fire regimes may change under future climate scenarios is critical for developing adaptation strategies, said the study's lead author, Alex Dye.

Findings were published today in JGR Biogeosciences.

Dye, a faculty research associate in the OSU College of Forestry, and collaborators with the U.S. Forest Service conducted novel, comprehensive wildfire simulations for more than 23 million acres of forest land west of the Cascade Range crest in Oregon and Washington.

The simulations showed that by the 30-year period beginning in 2035, Washington's North Cascades region, the Olympic Mountains, the Puget Lowlands and the western Oregon Cascades could see at least twice as much fire activity as was observed during the prior 30 years, Dye said.

To a lesser degree, that trend holds for the western Washington Cascades and the Oregon Coast Range, he added.

Forests in all of the affected areas are linchpins of multiple socio-ecological systems in the Northwest, Dye said, meaning more fire will likely put pressure on everything from drinking water sources and timber resources to biodiversity and carbon stocks.

"The moist, highly productive forests of the Northwest don't get fire as often as other parts of the West, like California or eastern Oregon," Dye said.

"But fire does naturally occur in the PNW 'Westside' as we call it -- the fire regimes are actually quite complex in this region. It can be challenging to assess fire probability in an environment where there isn't a lot of empirical information about the fire history to build models."

The comparative infrequency of fire also means it's easy for the general public to think of the Westside as not a high-risk area, and it also means the region is generally not a focal point of studies such as the one he just completed, Dye said.

But recent big blazes such as those that occurred in the Northwest around Labor Day 2020 showed what can happen when severe fire strikes Westside areas.

"And what if fires like that were to start happening more frequently in the near future?" Dye said.

"What if that once every 200 years became once every 50 years, or once every 25 years as climate change brings hotter and drier conditions to the region?"

Climate is just one factor influencing wildfire, he noted, but it is an important one.

He sees the findings as a crucial planning tool to help the Northwest prepare for a rapid acceleration of fire over the next few decades.

"Describing the possibilities of how, when and where climate change could affect fire regimes helps bracket everyone's expectations," he said.

"Particularly important among our findings are new insights into the possibility of shifts towards more frequent and large fires, especially those greater than 40,000 hectares as well as shifts toward more fires burning at the beginning of fall when extreme weather has the potential to increase fire spread."

Forty thousand hectares is just under 99,000 acres.

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Baleen whales evolved a unique larynx to communicate but cannot escape human noise

Baleen whales are the largest animals to have ever roamed our planet and as top predators play a vital role in marine ecosystems. To communicate across vast distances and find each other, baleen whales depend critically on the production of sounds that travels far in murky and dark oceans.

However, since whale songs were first discovered more than 50 years ago, it remained unknown how baleen whales produce their complex vocalizations -- until now.

A new study in the journal Nature reports that baleen whales evolved unique structures in their larynx that enable their low-frequency vocalizations, but also limit their communication range.

The study was led by voice scientists Professor Coen Elemans, at the Department of Biology, University of Southern Denmark and Professor Tecumseh Fitch at the Department of Behavioral and Cognitive Biology, University of Vienna in Austria.

"The toothed and baleen whales evolved from land mammals that had a larynx serving two functions: protecting the airways and sound production. However, their transition to aquatic life placed new and strict demands on the larynx to prevent choking underwater," says Tecumseh Fitch.

The study shows that baleen whales nevertheless can still produce sound with their larynx, but they have evolved novel structures to do so, that only exists in baleen whales. First, the tiny cartilages in the human larynx -- called the arytenoids -- that change the position of our vocal folds, have changed dramatically in whales.

"The arytenoids changed into large, long cylinders fused at the base to form a large U-shaped rigid structure that extends nearly the full length of the larynx," Elemans says.

"This is probably to keep a rigid open airway when they have to move huge amounts of air in and out during explosive surface breathing," states Fitch.

"We found that this U-shaped structure pushes against a big fatty cushion on the inside of the larynx. When the whales push air from their lungs past this cushion, it starts to vibrate and this generates very low frequency underwater sounds," says Elemans.

Trying to work on the biology and particularly physiology of whales is very challenging.

"Even though humans hunted whales close to the brink of extinction, they made very little effort in trying to learn about their physiology," says Magnus Wahlberg, whale expert at University of Southern Denmark and co-author on the study.

"Strandings are unique and rare opportunities to learn about these amazing animals, but even then, it is very hard to study physiology, because the tissue decays so fast. Whales are known to explode on the beach," adds Wahlberg.

Thanks to Danish and Scottish Marine Mammal Stranding Networks, the researchers could quickly extract the larynx of a sei, minke and humpback whale for close investigation in the lab.

"Our experiments showed for the first time how the whales make their very low frequency vocalizations," says Elemans.

To understand how muscle activity could change the calls, the researchers built a computational model of the entire whale larynx.

"Our model includes accurate 3D shapes of the larynx and its muscles, which made it possible to simulate, for example, how the frequency is controlled through muscle modulation," say Qian Xue and Xudong Zheng, professors at the Mechanical Engineering Department at Rochester Institute of Technology, USA, co-authors on the study.

"Our model accurately predicted the results of our experiments, but we could also calculate acoustic features we could not measure in the lab, such as the frequency range," says Weili Jiang, postdoc at Rochester Institute of Technology, USA, co-author on the study.

The models predicted the natural vocalizations of the whales very well.

However, these newly discovered anatomical features that allowed whales to successfully communicate in the vast oceans also poses unsurmountable physiological limits for many baleen whales.

Combining experiments and models, the researchers provide the first evidence that baleen whales are physiologically incapable of escaping anthropogenic noise, because it masks their voices, and thus limits their communication range.

"Regrettably, the frequency range and maximum communication depth of 100 meters we predict, overlaps completely with the dominant frequency range and depth of human-made noise caused by shipping traffic," Elemans says.

"The first acoustic recordings of humpback whale song by Roger and Katy Payne in 1970 resonated with humanity profoundly, started the flourishing field of marine bioacoustics, and sparked global interest in marine conservation efforts." says Coen Elemans.

"These recordings were so politically important then that they are aboard the Voyager space missions," he continues.

The Payne's made people aware how quiet the seas were before humans started the widespread use of propeller ships and continuously running shipboard generators. Those were the seas whales evolved in.

Read more at Science Daily

Giant new snake species identified in the Amazon

A team of scientists on location with a film crew in the remote Amazon has uncovered a previously undocumented species of giant anaconda.

Professor Bryan Fry from The University of Queensland led a team which captured and studied several specimens of the newly named northern green anaconda (Eunectes akayima), located in the Bameno region of Baihuaeri Waorani Territory in the Ecuadorian Amazon.

"Our team received a rare invitation from the Waorani people to explore the region and collect samples from a population of anacondas, rumoured to be the largest in existence," Professor Fry said.

"The indigenous hunters took us into the jungle on a 10-day expedition to search for these snakes, which they consider sacred.

"We paddled canoes down the river system and were lucky enough to find several anacondas lurking in the shallows, lying in wait for prey.

"The size of these magnificent creatures was incredible -- one female anaconda we encountered measured an astounding 6.3 metres long.

"There are anecdotal reports from the Waorani people of other anacondas in the area measuring more than 7.5 metres long and weighing around 500 kilograms."

Professor Fry said the northern green anaconda species diverged from the southern green anaconda almost 10 million years ago, and they differ genetically by 5.5 per cent.

"It's quite significant -- to put it in perspective, humans differ from chimpanzees by only about 2 per cent," he said.

"This discovery is the highlight of my career."

The new anaconda species was found while filming with National Geographic for their upcoming Disney+ series Pole to Pole with Will Smith, on which Professor Fry, a National Geographic Explorer, was the expedition's scientific leader.

"Our journey into the heart of the Amazon, facilitated by the invitation of Waorani Chief Penti Baihua, was a true cross-cultural endeavour," he said.

"The importance of our Waorani collaborators is recognised with them being co-authors on the paper."

The scientists also set out to compare the genetics of the green anaconda with specimens collected elsewhere by world-leading anaconda expert Dr Jesus Rivas from New Mexico Highlands University, and use them as an indicator species for ecosystem health.

Professor Fry said the Amazon continues to face alarming ecological threats.

"Deforestation of the Amazon basin from agricultural expansion has resulted in an estimated 20-31 per cent habitat loss, which may impact up to 40 per cent of its forests by 2050," he said.

"Another increasing problem is habitat degradation from land fragmentation, led by industrialised agriculture and heavy metal pollution associated with spills from oil extraction activities.

"Forest fires, drought and climate change are also notable threats.

"These rare anacondas, and the other species that share this remote ecosystem, face significant challenges."

Professor Fry said his next research project would focus on heavy metal pollution in the Amazon.

"It's not only these gigantic snakes that are facing environmental threats, but almost all living things in the region," he said.

"The discovery of a new species of anaconda is exciting, but it is critical to highlight the urgent need to further research these threatened species and ecosystems.

Read moer at Science Daily

Black hole at center of the Milky Way resembles a football

The supermassive black hole in the center of the Milky Way is spinning so quickly it is warping the spacetime surrounding it into a shape that can look like a football, according to a new study using data from NASA's Chandra X-ray Observatory and the U.S. National Science Foundation's Karl G. Jansky Very Large Array (VLA). That football shape suggests the black hole is spinning at a substantial speed, which researchers estimated to be about 60% of its potential limit.

The work, led by Penn State Berks Professor of Physics Ruth Daly, was published in the Monthly Notices of the Royal Astronomical Society.

Astronomers call this giant black hole Sagittarius A* (Sgr A*). It is located about 26,000 light-years away from Earth in the center of the galaxy. To determine how quickly Sgr A* is spinning -- one of its fundamental properties, along with mass -- the researchers applied a method that uses X-ray and radio data to assess how material is flowing towards and away from the black hole. The method was developed and published by Daly in 2019 in The Astrophysical Journal.

"Our work may help settle the question of how fast our galaxy's supermassive black hole is spinning," Daly said. "Our results indicate that Sgr A* is spinning very rapidly, which is interesting and has far-reaching implications."

The team found the angular velocity -- the number of revolutions per second -- of Sgr A*'s spin is about 60% of the maximum possible value, a limit set because material cannot travel faster than the speed of light.

Past estimations of Sgr A*'s speed have been made with different techniques and by other astronomers, with results ranging from no rotation at all to spinning at almost the maximum rate.

"This work, however, shows that this could change if the amount of material in the vicinity of Sgr A* increases," Daly said.

As a black hole rotates, it pulls "spacetime" -- the combination of time and the three dimensions of space -- and nearby matter. The gravitational pull also squashes the spacetime, altering its shape depending on how it's observed. Spacetime appears circular if the black hole is viewed from the top. From the side, however, the spacetime is shaped like a football. The faster the spin, the flatter the football.

The spin can also serve as an energy source, Daly said, if matter -- such as gas or the remnants of a star that wanders too close -- exists in the vicinity of the black hole. As the black hole spins, matter can escape in the form of narrow jets called collimated outflows. However, Sgr A* currently has limited nearby matter, so the black hole has been relatively quiet, with weakly collimated outflows, in recent millennia.

"A spinning black hole is like a rocket on the launch pad," said Biny Sebastian, a co-author from the University of Manitoba in Winnipeg, Canada. "Once material gets close enough, it's like someone has fueled the rocket and hit the 'launch' button."

This means that in the future, if the properties of the matter and the magnetic field strength close to the black hole change, part of the enormous energy of the black hole's spin could drive more powerful outflows. This source material could come from gas or from the remnants of a star torn apart by the black hole's gravity if that star wanders too close to Sgr A*.

"Jets powered and collimated by a galaxy's spinning central black hole can profoundly affect the gas supply for an entire galaxy, which affects how quickly and even whether stars can form," said co-author Megan Donahue from Michigan State University. "The 'Fermi bubbles' seen in X-rays and gamma rays around our Milky Way's black hole show the black hole was probably active in the past. Measuring the spin of our black hole is an important test of this scenario."

Fermi bubbles refer to structures that emit gamma rays above and below the black hole that researchers have theorized resulted from prior massive outflows.

The researchers used the outflow method to determine the spin of Sgr A*. Daly's approach incorporates consideration of the relationship between the spin of the black hole and its mass, the properties of the matter near the black hole and the outflow properties. The collimated outflow produces the radio waves, while the disk of gas surrounding the black hole emits X-rays. The researchers combined observational data from Chandra and the VLA with an independent estimate of the black hole's mass from other telescopes to inform the outflow method and determine the black hole's spin.

"We have a special view of Sgr A* because it is the nearest supermassive black hole to us," said co-author Anan Lu from McGill University in Montreal, Canada. "Although it's quiet right now, our work shows that in the future it will give an incredibly powerful kick to surrounding matter. That might happen in a thousand or a million years, or it could happen in our lifetimes."

Read more at Science Daily

Decline in microbial genetic richness in the western Arctic Ocean

The Arctic region is experiencing climate change at a much faster rate than the rest of the world. Melting ice sheets, runoff from thawing permafrost and other factors are rapidly changing the composition of the Arctic Ocean's water. And that change is being experienced all the way down to the microbial level.

In a Concordia-led study published in the journal ISME Communications, researchers analyzed archival samples of bacteria and archaea populations taken from the Beaufort Sea, bordering northwest Canada and Alaska.

The samples were collected between 2004 and 2012, a period that included two years -- 2007 and 2012 -- in which the sea ice coverage was historically low.

The researchers looked at samples taken from three levels of water: the summer mixed layer, the upper Arctic water below it and the Pacific-origin water at the deepest level.

The study examined the microbes' genetic composition using bioinformatics and statistical analysis across the nine-year time span.

Using this data, the researchers were able to see how changing environmental conditions were influencing the organisms' structure and function.

The researchers found subtle but statistically significant changes in the communities they studied.

"We observed a general overall loss in diversity of species across all the different water masses," says David Walsh, a professor in the Department of Biology and the paper's corresponding author.

"We also saw changes in the composition of the microbial community, meaning there were different species after the 2007 sea ice minimum than before."

However, the periods of population richness decline changed between the ocean's layers of water.

Sudden decline in the fresher summer mixed water level, between 3-9 meters deep, was observed in 2005-2007.

The upper Arctic water, between 16-78 metres, saw declines in 2010-2012, while the deeper Pacific water layer, between 49-154 meters, experienced a two-step decline -- once between 2005-2007 and again between 2010-2012.

Small beginnings

The researchers are taking care not to overemphasize the results of their findings, saying the changes, while significant, remain slight.

But with the summer Arctic ice cover shrinking steadily year over year, the data does hint at possible trends that may be visible in upcoming population studies in more recent years.

"With the warming and freshening of the Arctic Ocean comes a decrease of nutrients that are important for photosynthesis, which produces the organic matter that serves as energy and carbon sources for the marine food web," Walsh explains.

"This shift risks strengthening what is known as the microbial loop, in which the energy and carbon that would normally go into higher trophic levels -- meaning zooplankton and then fish -- is rapidly recycled by microorganisms. This ecosystem is already dominated by microbial processes, which will only get stronger as this system continues."

"This study provides us with a baseline idea of what is happening in the Arctic," says co-author Arthi Ramachandran, PhD 23. "The Arctic is warming four times faster than the rest of the world, which makes it a fascinating ecosystem to study. The oceans are all interconnected, and the physical barriers of these oceans are becoming much less defined."

Looking into the ocean's warmer, fresher future

The researchers are now planning a metagenomic study that extends the time series to cover periods of even more intense sea ice minima.

They hope to fully sequence the organisms' genomes to further understand the microbial communities' diversity and function in the environment.

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Science fiction meets reality: New technique to overcome obstructed views

After a recent car crash, John Murray-Bruce wished he could have seen the other car coming. The crash reaffirmed the University of South Florida assistant professor of computer science and engineering's mission to create a technology that could do just that: See around obstacles and ultimately expand one's line of vision.

Using a single photograph, Murray-Bruce and his doctoral student, Robinson Czajkowski, created an algorithm that computes highly accurate, full-color three-dimensional reconstructions of areas behind obstacles -- a concept that can not only help prevent car crashes, but help law enforcement experts in hostage situations, search-and-rescue and strategic military efforts.

"We're turning ordinary surfaces into mirrors to reveal regions, objects and rooms that are outside our line of vision," Murray-Bruce said.

"We live in a 3D world, so obtaining a more complete 3D picture of a scenario can be critical in a number of situations and applications."

As published in Nature Communications, Czajkowski and Murray-Bruce's research is the first-of-its-kind to successfully reconstruct a hidden scene in 3D using an ordinary digital camera.

The algorithm works by using information from the photo of faint shadows cast on nearby surfaces to create a high-quality reconstruction of the scene.

While it is more technical for the average person, it could have broad applications.

"These shadows are all around us," Czajkowski said. "The fact we can't see them with our naked eye doesn't mean they're not there."

The idea of seeing around obstacles has been a topic of science-fiction movies and books for decades.

Murray-Bruce says this research takes significant strides in bringing that concept to life.

Prior to this work, researchers have only used ordinary cameras to create rough 2D reconstructions of small spaces.

The most successful demonstrations of 3D imaging of hidden scene all required specialized, expensive equipment.

"Our work achieves a similar result using far less," Czajkowski said.

"You don't need to spend a million dollars on equipment for this anymore."

Czajkowski and Murray-Bruce expect it will be 10 to 20 years before the technology is robust enough to be adopted by law enforcement and car manufacturers.

Right now, they plan to continue their research to further improve the technology's speed and accuracy to expand its applications in the future, including self-driving cars to improve their safety and situational awareness.

"In just over a decade since the idea of seeing around corners emerged, there has been remarkable progress and there is accelerating interest and research activity in the area," Murray-Bruce said.

"This increased activity, along with access to better, more sensitive cameras and faster computing power form the basis for my optimism on how soon this technology will become practical for a wide range of scenarios."

Read more at Science Daily

Did neanderthals use glue? Researchers find evidence that sticks

Neanderthals created stone tools held together by a multi-component adhesive, a team of scientists has discovered. Its findings, which are the earliest evidence of a complex adhesive in Europe, suggest these predecessors to modern humans had a higher level of cognition and cultural development than previously thought.

The work, reported in the journal Science Advances, included researchers from New York University, the University of Tübingen, and the National Museums in Berlin.

"These astonishingly well-preserved tools showcase a technical solution broadly similar to examples of tools made by early modern humans in Africa, but the exact recipe reflects a Neanderthal 'spin,' which is the production of grips for handheld tools," says Radu Iovita, an associate professor at New York University's Center for the Study of Human Origins.

The research team, led by Patrick Schmidt from the University of Tübingen's Early Prehistory and Quaternary Ecology section and Ewa Dutkiewicz from the Museum of Prehistory and Early History at the National Museums in Berlin, re-examined previous finds from Le Moustier, an archaeological site in France that was discovered in the early 20th century.

The stone tools from Le Moustier -- used by Neanderthals during the Middle Palaeolithic period of the Mousterian between 120,000 and 40,000 years ago -- are kept in the collection of Berlin's Museum of Prehistory and Early History and had not previously been examined in detail.

The tools were rediscovered during an internal review of the collection and their scientific value was recognized.

"The items had been individually wrapped and untouched since the 1960s," says Dutkiewicz.

"As a result, the adhering remains of organic substances were very well preserved."

The researchers discovered traces of a mixture of ochre and bitumen on several stone tools, such as scrapers, flakes, and blades.

Ochre is a naturally occurring earth pigment; bitumen is a component of asphalt and can be produced from crude oil, but also occurs naturally in the soil.

"We were surprised that the ochre content was more than 50 percent," says Schmidt.

"This is because air-dried bitumen can be used unaltered as an adhesive, but loses its adhesive properties when such large proportions of ochre are added."

He and his team examined these materials in tensile tests -- used to determine strength -- and other measures.

"It was different when we used liquid bitumen, which is not really suitable for gluing. If 55 percent ochre is added, a malleable mass is formed," Schmidt says.

The mixture was just sticky enough for a stone tool to remain stuck in it, but without adhering to hands, making it suitable material for a handle.

In fact, a microscopic examination of the use-wear traces on these stone tools revealed that the adhesives on the tools from Le Moustier were used in this way.

"The tools showed two kinds of microscopic wear: one is the typical polish on the sharp edges that is generally caused by working other materials," explains Iovita, who conducted this analysis.

"The other is a bright polish distributed all over the presumed hand-held part, but not elsewhere, which we interpreted as the results of abrasion from the ochre due to movement of the tool within the grip."

The use of adhesives with several components, including various sticky substances such as tree resins and ochre, was previously known from early modern humans, Homo sapiens, in Africa but not from earlier Neanderthals in Europe.

Overall, the development of adhesives and their use in the manufacture of tools is considered to be some of the best material evidence of the cultural evolution and cognitive abilities of early humans.

"Compound adhesives are considered to be among the first expressions of the modern cognitive processes that are still active today," says Schmidt.

In the Le Moustier region, ochre and bitumen had to be collected from distant locations, which meant a great deal of effort, planning, and a targeted approach, the authors note.

"Taking into account the overall context of the finds, we assume that this adhesive material was made by Neanderthals," concludes Dutkiewicz.

"What our study shows is that early Homo sapiens in Africa and Neanderthals in Europe had similar thought patterns," adds Schmidt.

Read more at Science Daily

Spy-satellite images offer insights into historical ecosystem changes

A large number of historical spy-satellite photographs from the Cold War Era were declassified decades ago. This valuable remote sensing data has been utilised by scientists across a wide range of disciplines from archaeology to civil engineering. However, its use in ecology and conservation remains limited. A new study led by Dr. Catalina Munteanu from the Faculty of Environment and Natural Resources at the University of Freiburg, Germany, aims to advance the application of declassified satellite data in the fields of ecology and conservation. Leveraging recent progress in image processing and analysis, these globally available black-and-white images can offer better insights into the historical changes of ecosystems, species populations or changes in human influences on the environment dating back to the 1960s, the researchers suggest.

Historical satellite images cover nearly the entire globe across all seasons

In their study, the researchers initially evaluated the spatial, temporal, and seasonal coverage of over one million declassified images from four historical US spy-satellite programmes, showing that this data spans nearly the entire globe and is available across all seasons.

Upon reviewing how spy-satellite imagery is currently employed in ecology-related fields, the team then identified potential future applications.

Crucially, the broad spatial-temporal scale of the satellite images could enhance the understanding of ecological concepts such as shifting baselines, lag effects, and legacy effects.

This improved understanding could lead to better mapping of the historical extent and structure of ecosystems, aid in the reconstruction of past habitats and species distributions as well as offer new insights into historical human impacts on present ecosystem conditions.

Going forward, this knowledge can also be helpful for conservation planning and ecosystem restoration efforts by helping identify, for example, meaningful ecological baselines, the researchers explain.

Read more at Science Daily