Scientists solve enigma of why Lake Geneva emits large quantities of CO₂

OCT. 30, 2024, by U. of Lausanne

https://phys.org/news/2024-10-scientists-enigma-lake-geneva-emits.html

Climatology of observations and simulations.

(A to C) Climatology of surface (averaged on 0- to 10-m depth) daily observations (Obs.) and models outputs when CP is enabled (i.e., the reference model, Mod. CP) or muted (Mod. noCP). DOY, Day of Year. The continuous colored line represents the daily average from 1981 to 2021; the dotted lines are the SD. The colored bar above represents seasons (sequentially winter-spring-summer-fall) (A) DIC, (B) pH, and (C) Pco2. The gray line represents Pco2 at equilibrium with the atmosphere. The vertical dotted lines indicate DOY 50, 180, and 300, for which 

the vertical Pco2 profiles are exemplified in (D to F). Vertical profiles (daily average ± SD for 1981–2021) over the first 50 m of observed and simulated Pco2 with enabled or muted CP at (D) DOY 50, (E) DOY 180, and (F) DOY 300. 

Color codes are the same for (A) to (C). 

Credit: Science Advances (2024). DOI: 10.1126/sciadv.ado5924

Like most lakes in the world, Lake Geneva is an emitter of greenhouse gases, particularly carbon dioxide (CO2). Annually, it produces as much CO2 as the automobile transport of the city of Lausanne (≃ 150,000 inhabitants). This phenomenon—the production of CO2 by lakes—has been known for years. There is, however, widespread debate as to the mechanisms at work.

Traditional scientific theories suggest that lake CO2 emissions are primarily due to the influx of organic matter from surrounding soils. This material, originating from the decomposition of plant and animal residues, is carried into the lake by rainfall, where it is broken down by microorganisms, leading to the release of CO2. This process is known as respiration.

While this theory accounts for the behavior of some lakes, it doesn't apply to Lake Geneva, which receives very little organic matter from its shores. In theory, its annual carbon balance should be neutral, with winter CO2 production (from organic matter decomposition and water mixing) balanced by summer CO2 absorption (due to algae photosynthesis). So why does Lake Geneva still emit large amounts of CO2?

A team of UNIL scientists has just deciphered the mechanisms involved. Most of the emissions actually come from the natural erosion of rocks in the lake's upstream basin. When rainwater hits the rocks, it releases bicarbonate and calcium ions, which then find their way into the lake. In summer, under the effect of heat and the growth of algae—which change the pH of the water and act as a catalyst—the ions form microparticles of limestone. This is known as calcite precipitation.

This chemical reaction releases CO2, giving the lake its milky blue-green appearance in the warm season. Algae continue to absorb CO2, but this is not enough to compensate for the massive production resulting from rock erosion. The additional emissions are therefore the result of a geological process, not just a biological one, as previously thought.

This discovery was published in Science Advances.

"Our results not only explain the carbon cycle in Lake Geneva, they also reveal a universal process that applies to several of the world's great lakes," explains Marie-Elodie Perga, professor of limnology at UNIL's Faculty of Geosciences and Environment and co-author of the study.

"This issue had been nagging at me since my thesis," she explains. "Using a scientific infrastructure that is unique in the world—the LéXPLORE platform—we were able to observe, model and equate these processes on a very fine scale, providing the missing piece to traditional carbon cycle modeling."

Laid out on Lake Geneva, the floating laboratory made it possible to monitor various parameters linked to the carbon cycle, continuously and at high frequency.

In addition to the purely scientific interest of this discovery, this new data is central to the fight against global warming.

"Assessments are carried out every year to identify the emitters (sources) and storages (sinks) of carbon on our planet," explains Perga. "It's very important to have in-depth knowledge of how CO2 is naturally transported, stored and transformed between continents, water and the atmosphere. Only a global vision will enable us to take effective action to combat global warming."

The LéXPLORE platform

LéXPLORE is a 10 m x 10 m scientific research platform located on Lake Geneva in Switzerland, almost 600 m from the shore. It is equipped with high-tech instrumentation (109 sensors) and provides continuous measurements, day and night, in all weather conditions.

LéXPLORE brings together five institutions (EPFL, EAWAG, INRAE, UNIL, UNIGE) conducting cutting-edge, multidisciplinary research on the lake and its atmosphere. It is also used as a training and teaching facility, and as a popularization tool for the general public.

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Tunic found in one of the Royal Tombs at Vergina identified as Alexander the Great's

Oct. 30, 2024 **report**, by B. Yirka , Phys.org

https://phys.org/news/2024-10-tunic-royal-tombs-vergina-alexander.html

Credit: Unsplash/CC0 Public Domain

An international team of archaeologists, led by Antonis Bartsiokas with Democritus University of Thrace, in Greece, has uncovered evidence that a tunic found in one of the Royal Tombs at Vergina once belonged to Alexander the Great.

In his paper published in the Journal of Field Archaeology, Bartsiokas outlines the evidence surrounding the purple and white tunic and also claims that he and his team have definitively identified the remains of three of the people entombed at the famous burial site.

Prior research has suggested that several members of Alexander the Great's family were laid to rest in the Royal Tombs at Vergina—the gravesite of the famous Macedonian king is not known, though it is most certainly not the Royal Tombs at Vergina. Such findings have made the site in Greece famous. In this new effort, Bartsiokas and colleagues took a new look at three of the tombs at the site, which have been informally named Tomb I, II and III.

Using a variety of testing techniques and historical reference works, the researchers found what they describe as evidence that the remains in Tomb I belong to Philip II, Alexander's father. Those in Tomb II belong to Alexander's half-brother Philip III, and the remains in Tomb II are those of Alexander IV, Alexander's son, who died while still in his teens.

Perhaps most intriguing about the work, however, is the purple and white tunic found along with the remains in Tomb II—a tunic is a fitted jacket similar to that worn by Captain Picard of "Star Trek: The Next Generation." By testing via gas chromatography and Fourier-transform infrared spectroscopy, the researchers determined that the tunic was made of cotton and had been dyed using a purple color that was only allowed for the elite.

They note also that the tunic was featured in a frieze in Tomb II by a hunter identified as Alexander. Also, the tunic was found near a scepter, oak wreath and diadem, all made of gold, which are believed to have a possible link with ancient Persia, and by extension, to Alexander.

The research team was not able to explain why the tunic and other gold materials associated with Alexander the Great were left in the tomb, though they suspect it might have had something to do with Philip III being crowned king when Alexander died.

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Plans to cool the Earth by blocking sunlight are gaining momentum, but critical voices risk being excluded

OCT. 30, 2024, by A. Van Wijngaarden, A. Hindes and C. Colomer, The Conversation

https://phys.org/news/2024-10-cool-earth-blocking-sunlight-gaining.html

The 1991 eruption of Mount Pinatubo in the Philippines blocked so much sunlight the world temporarily cooled by a few tenths of a degree. Solar geoengineering works on a similar principle. 

Credit: Dave Harlow / USGS

Solar geoengineering research is advancing fast, after a recent flurry of funding announcements. Yet these technologies are still speculative and have many critics, and we worry their concerns won't be heard. If geoengineering is essentially allowed to self-regulate, with no effective global governance, future research could easily take us down a dangerous path.

Solar geoengineering refers to proposals to reduce global warming by reflecting a portion of sunlight back into space before it reaches the Earth's surface. In its best-known form, this means using high-flying aircraft to inject tiny reflective particles into the upper atmosphere.

This so-called "stratospheric aerosol injection" hasn't actually happened yet, beyond a few very small experiments with balloons. Yet for a long time, such ideas remained fringe and too controversial to even consider—and for some academics they still are.

The academic discussion was highly polarized from the start. Opponents, mainly governance scholars and social scientists, stood firmly entrenched against assumed proponents, mainly natural scientists and engineers. Both sides had their champions, arguments, assumptions, key publications and meetings, generally working on the topic without proper engagement with the other side.

This polarization is still visible in publishing today. Take, for example, articles on The Conversation. Critics focus on potential negatives such as altered rainfall patterns, the infringement of human rights, or even a catastrophic "termination shock". Advocates highlight potential benefits such as reducing extreme heat and preserving ice caps, while others suggest we may soon be forced to try it.

The authors of these articles are all academic experts. Yet they come from different disciplines and use different arguments.

A public and private funding boom

Though the two camps have not resolved their arguments, geoengineering research funding is suddenly booming. There are major philanthropic pledges of US$50 million (£38 million) and US$30 million from the Simons and Quadrature Climate foundations, which are vying for the title of biggest donor with the £10.5 million and £56.8 million of the UK government's UKRI and Advanced Research and Innovation Agency programs.

Other key organizations speaking about the need for more research include the European Commission, the US government and the World Climate Research Program. This comes on top of the shock of controversial private enterprises pushing for solar geoengineering, most notoriously the US-based start-up Make Sunsets.

Support is certainly not unanimous. Many prominent scholars have signed up to a call for a moratorium, for instance. And at a recent UN Environment Assembly session in Kenya, many climate-vulnerable nations mobilized against calls for further research into what they see as a highly risky technology that would enable big emitters to carry on emitting.

However, many powerful interests are seemingly in favor of more research, while the 1.5°C global warming target is moving ever further out of sight. In the near future, we can therefore expect further research, perhaps including small-scale outdoor experiments.

As Ph.D. students working on geoengineering, situated somewhere between both camps, we have found this polarization deeply unproductive and difficult to deal with. Our own research sometimes feels like wandering through a minefield of opinions and perspectives. Yet we can also see the valuable concerns and hopes of both sides.

That's why we believe that upcoming research projects must factor in the concerns of opponents, and not represent only supporters of geoengineering or those who have not been explicitly against it. Excluding critical voices would directly impact the scientific process, for one thing.

But this exclusion is especially worrying as there are currently no governance structures for solar geoengineering. If efforts to develop such governance only involve supportive researchers, they could lack the critical capacity to prevent risks or undesired effects. Disasters in the financial sector and the chemical industry warn us of the perils of self-regulation without critical voices.

Learn from the critics

There are other critiques that ought to be factored into any major research project. They include concerns that simply researching the technology will create a slippery slope towards it being deployed, or worries that geoengineering ignores the social and political dynamics behind climate change and addresses only its outcomes. There are also major governance concerns over issues such as the role of the military (could geoengineering be deployed for security reasons in contested regions like the Arctic?), or the concentration of research at influential institutions in the US and Europe.

Over time, geoengineering researchers have become more aware of such arguments and some are explicitly trying to include them in their work. The American Geophysical Union has recently published an ethical framework for geoengineering, which should provide valuable guidance for any research project. But without active dialogue with critical scholars, their arguments will likely only echo faintly in the pro-research space.

In practice, more engagement between the two camps would come with many difficulties. For advocates, it can be tempting to avoid such debates and exclude those who disagree with the very foundations on which their research is built. On the flip side, some scholars who have already explicitly argued against the continuation of solar geoengineering research would nevertheless have to participate in it.

The practical implications will therefore need to be carefully worked out. However, a more productive dialogue might still shape a future that can be acceptable to all sides.

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Smell loss is linked to more than 100 diseases in new study

OCT. 29, 2024, by E. Perez, U. of California, Irvine

https://medicalxpress.com/news/2024-10-loss-linked-diseases.html

Credit: Pixabay/CC0 Public Domain

Researchers from the Charlie Dunlop School of Biological Sciences, in collaboration with The Oxford Research Centre in the Humanities, reveal a powerful link between olfactory loss and inflammation in a staggering 139 medical conditions. This research—led by professor emeritus Michael Leon, and researchers Cynthia Woo and Emily Troscianko—emphasizes a little-known but potentially life-altering connection: the role our sense of smell plays in maintaining our physical and mental health.

The study appears in Frontiers in Molecular Neuroscience.

Olfactory dysfunction, often dismissed as a minor inconvenience, may actually be an early sign of various neurological and bodily diseases, as indicated by this research.

"The data are particularly interesting because we had previously found that olfactory enrichment can improve the memory of older adults by 226%," said Leon. "We now know that pleasant scents can decrease inflammation, potentially pointing to the mechanism by which such scents can improve brain health."

This finding, he added, could hold key implications for mitigating symptoms and possibly even reducing the onset of certain diseases through therapeutic olfactory stimulation.

The study delves into the methodical tracking of 139 medical conditions associated with both olfactory loss and heightened inflammation, uncovering insights into a shared pathway linking these factors. Olfactory loss, which often precedes conditions such as Alzheimer's and Parkinson's diseases, may serve as an early indicator of disease onset, allowing for more proactive therapeutic approaches.

"It was difficult to track down the studies for so many medical conditions," said Leon, reflecting on the complexity of linking olfactory loss to such a wide array of disorders. The challenge, he added, underscores the importance of these findings in framing olfactory health as integral to overall well-being.

By showing how olfactory enrichment can mitigate inflammation, this research has laid a foundation for future studies aiming to explore the therapeutic use of scent to address a broader range of medical conditions.

"It will be interesting to see if we can ameliorate the symptoms of other medical conditions with olfactory enrichment," said Leon.

Together with Woo, Leon is now working on a device to deliver olfactory therapy, which could hold promise as a novel, non-invasive way to improve health outcomes.

As science continues to uncover the profound impacts of our senses on health, this research underscores a critical need for further study into olfactory therapies.

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Adaptability of trees persists after millions of years of climate change, finds study

OCT. 14, 2024, by Uppsala U.

https://phys.org/news/2024-10-trees-persists-millions-years-climate.html

Credit: Unsplash/CC0 Public Domain

Seven of the most common forest trees in Europe have been shown to be able to shelter their genetic diversity from major shifts in environmental conditions. This is despite their ranges having shrunk and the number of trees having fallen sharply during ice age cycles. These are the findings of a study by a European consortium including Uppsala University, published in Nature Communications.

"From a biodiversity perspective, this is very positive because these trees are keystone species on which many other species depend," says Pascal Milesi, Associate Professor of Plant Ecology and Evolution at Uppsala University and first author of the study.

The researchers aimed to investigate how the genetic diversity of tree species was affected by the ice age cycles. Trees have lived through warm and cold periods. During the last ice age, about 10,000 years ago, the range of trees was greatly reduced. Scientists therefore thought that genetic diversity would be low. However, it turned out to be just the opposite—the species had high genetic diversity and were thus resilient to the drastic changes in their habitat.

"We believe the reason for this high genetic diversity is related to the way these tree species survived through the ice ages and to the fact that tree pollen can travel thousands of kilometers, bringing together trees that grow far apart. This is a welcome sign. The evolutionary processes that were at play in the past may also be useful to cope with today's rapid climate change," Milesi says.

Together with scientists from 22 European research institutes, he studied seven species of forest trees common in Europe, collecting needles and leaves from around 3,500 trees in 164 different populations across Europe. Their DNA was then extracted and analyzed.

"Contrary to what was long thought, the ice age cycles had little impact on the genetic diversity of these seven key species. This is mainly explained by a combination of unique characteristics, namely long generation time and the ability of their pollen to spread thousands of kilometers," says Milesi.

In Sweden, the study focused on Norway spruce, Scots pine and silver birch, which together make up most of the Swedish forest and are important for other life forms. They also account for most of the timber in Swedish forestry, which means they are significant for the economy and society.

"Due to the sixth mass extinction event and the ongoing biodiversity crisis, people can easily get the feeling that it is too late and be ready to give up. This study sends a positive signal about our forest and provides important information to help manage forest biodiversity in the face of climate change," Milesi concludes.

The species studied were Fagus sylvatica (European beech), Pinus pinaster (Maritime pine), Quercus petraea (Sessile oak), Betula pendula (Silver birch), Pinus sylvestris (Scots pine), Picea abies (Norway spruce) and Populus nigra (Black poplar).

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Ecologists suggest animal alcohol consumption more common than thought

OCT. 30, 2024, by Cell Press

https://phys.org/news/2024-10-alcohol-consumption-human-animals-rare.html

A spider monkey feedings on fruits of spondia mombin. 

Credit: Nicholas Chapoy

Anecdotes abound of wildlife behaving "drunk" after eating fermented fruits, but despite this, nonhuman consumption of ethanol has been assumed to be rare and accidental. Ecologists challenge this assumption in a review published October 30 in Trends in Ecology & Evolution. They argue that since ethanol is naturally present in nearly every ecosystem, it is likely consumed on a regular basis by most fruit- and nectar-eating animals.

"We're moving away from this anthropocentric view that ethanol is just something that humans use," says behavioral ecologist and senior author Kimberley Hockings of the University of Exeter. "It's much more abundant in the natural world than we previously thought, and most animals that eat sugary fruits are going to be exposed to some level of ethanol."

Ethanol first became abundant around 100 million years ago, when flowering plants began producing sugary nectar and fruits that yeast could ferment. Now, it's present naturally in nearly every ecosystem, though concentrations are higher, and production occurs year-round in lower-latitude and humid tropical environments compared to temperate regions.

Most of the time, naturally fermented fruits only reach 1–2% alcohol by volume (ABV), but concentrations as high as 10.2% ABV have been found in over-ripe palm fruit in Panama.

Animals already harbored genes that could degrade ethanol before yeasts began producing it, but there is evidence that evolution fine-tuned this ability for mammals and birds that consume fruit and nectar. In particular, primates and treeshrews have adapted to efficiently metabolize ethanol.

A capuchin eating fruits. 

Credit: Julia Casorso

"From an ecological perspective, it is not advantageous to be inebriated as you're climbing around in the trees or surrounded by predators at night—that's a recipe for not having your genes passed on," says molecular ecologist and senior author Matthew Carrigan of the College of Central Florida.

"It's the opposite of humans who want to get intoxicated but don't really want the calories—from the non-human perspective, the animals want the calories but not the inebriation."

It's unclear whether animals intentionally consume ethanol for ethanol's sake, and more research is needed to understand its impact on animal physiology and evolution. However, the researchers say that ethanol consumption could carry several benefits for wild animals.

First and foremost, it's a source of calories, and the odorous compounds produced during fermentation could guide animals to food sources, though the researchers say it's unlikely that animals can detect ethanol itself.

Ethanol could also have medicinal benefits: fruit flies intentionally lay their eggs in substances containing ethanol, which protects their eggs from parasites, and fruit fly larvae increase their ethanol intake when they become parasitized by wasps.

"On the cognitive side, ideas have been put forward that ethanol can trigger the endorphin and dopamine system, which leads to feelings of relaxation that could have benefits in terms of sociality," says behavioral ecologist and first author Anna Bowland of the University of Exeter. "To test that, we'd really need to know if ethanol is producing a physiological response in the wild."

There are a lot of unanswered questions regarding the significance of ethanol consumption to wild animals. In their future research, the team plans to investigate the behavioral and social implications of ethanol consumption in primates and to more deeply examine the enzymes involved in alcohol metabolism.

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Science News: Astronomers observe black hole that may have formed gently

 Astronomers observe black hole that may have formed gently

Black holes have previously been spotted orbiting with one

other star or one other black hole in what are called binary systems.

By Reuters, October 29, 2024

https://www.jpost.com/science/space/article-826674

Artist's impression shows a triple star system called V404 Cygni with a black hole and two ordinary stars. (photo credit: Jorge Lugo/Handout via REUTERS)

The conventional wisdom among astronomers is that black holes - those exceptionally dense objects with gravity so powerful that not even light can escape - form in the violent explosion, called a supernova, of a massive dying star. But some, it turns out, may be born in a gentler fashion.

Researchers have identified a black hole that appears to have come into being through the collapse of the core of a large star in its death throes, but without the usual blast. It was observed gravitationally bound to two ordinary stars.

Black holes have previously been spotted orbiting with one other star or one other black hole in what are called binary systems. But this is the first known instance of a triple system with a black hole and two stars.

This system is located about 7,800 light-years from Earth in the constellation Cygnus. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).

Artist’s view of a massive black hole mergers in a cluster, possibly like GW190521, a gravitational wave observation by LIGO/Virgo. (credit: Wikimedia Commons)

This black hole, called V404 Cygni, has been extensively studied since being confirmed in 1992. It previously was believed to be orbiting with only one other star, but data from the European Space Agency's Gaia space observatory showed it instead has two companions.

The researchers said the black hole, with an estimated mass nine times greater than our sun, is in the process of eating one of its companions, a star about seven-tenths as massive as the sun. That star orbits the black hole every 6-1/2 days at a distance only about one-seventh of that separating Earth and the sun.

The black hole appears to be siphoning material off this star, which had puffed up in what is called a red giant phase as part of its natural aging process.

Detecting black holes

The researchers detected another star about 1.2 times as massive as the sun gravitationally bound to these two but rather far away, orbiting them every 70,000 years at a distance 3,500 times greater than that separating Earth and the sun.

The reason the researchers suspect a gentle birthing process for the black hole is simple. The triple system would have broken apart, they said, if the star that became a black hole had exploded.

A black hole is thought to form when a large star exhausts the nuclear fuel at its core and collapses inward due to its own gravitational pull, triggering an immense explosion that blows off its outer layers into space. The resultant crushed core forms the black hole.

But some astronomers have proposed another path to black hole formation called "direct collapse" in which the star caves in after expending all its fuel but does not explode.

"We call these events a 'failed supernova.' Basically, the gravitational collapse just acts too quickly for the supernova to be able to trigger and you get an implosion instead - which sounds super dramatic and awesome but it's 'gentle' in the sense that you don't expel any matter," said Massachusetts Institute of Technology astronomer Kevin Burdge, lead author of the study published in the journal Nature.

The researchers estimated that the members of this triple system first formed about 4 billion years ago as ordinary stars.

"The triple system could not have survived if the black hole was born with a natal kick, so this discovery tells us that at least some black holes form without a kick - implying a quiet implosion rather than an explosive supernova," added Caltech astronomer and study co-author Kareem El-Badry.

This system will not have three members forever, considering that the black hole is consuming its closer neighbor. That suggests that some known binary systems with a black hole and an ordinary star originally may have formed as a triple system, only to have the black hole gobble up one of its partners.

"People have actually predicted that black hole binaries might form mostly through triple evolution, but there was never any direct evidence until now," El-Badry said

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Have we found all the major Maya cities? Not even close, new research suggests

Oct. 28, 2024, by Antiquity

https://phys.org/news/2024-10-major-maya-cities.html

Ancient buildings and landscape modifications—including public plazas, agricultural terraces, and field walls—blanket uplands. 

Archaeologists have analyzed lidar data from a completely unstudied corner of the Maya world in Campeche, Mexico, revealing 6,674 undiscovered Maya structures, including pyramids like those at the famous sites of Chichén Itzá or Tikal.

"For the longest time, our sample of the Maya civilization was a couple of hundred square kilometers total," says lead author Luke Auld-Thomas from Northern Arizona University. "That sample was hard won by archaeologists who painstakingly walked over every square meter, hacking away at the vegetation with machetes, to see if they were standing on a pile of rocks that might have been someone's home 1,500 years ago."

In the modern day, however, lidar technology allows scientists to scan large swaths of land from the comfort of an office, uncovering anomalies in the landscape that often prove to be pyramids, family houses and other Maya infrastructure.

There is a downside, though. Lidar survey is expensive, and granting organizations don't want to sink money into studying areas that are totally unknown and potentially devoid of Maya history. That's why one part of Campeche was still a blank spot on archaeologists' maps—until Auld-Thomas got an idea.

"Scientists in ecology, forestry and civil engineering have been using lidar surveys to study some of these areas for totally separate purposes," says Auld-Thomas. "So what if a lidar survey of this area already existed?"

As it turns out, it did. In 2013, a consortium focused on measuring and monitoring carbon in Mexico's forests had commissioned a very thorough lidar survey. Auld-Thomas, along with researchers at Tulane University, Mexico's Instituto Nacional de Antropología e Historia, and the University of Houston's National Center for Airborne Laser Mapping analyzed this lidar data to explore 50 square miles of Campeche, Mexico, that had never been examined by archaeologists before. Their results are now published in the journal Antiquity.

They discovered a dense, diverse array of totally unstudied Maya settlements dotted throughout the region, including an entire city. These findings might just settle a heated archaeological debate that's raged since the advent of lidar.

"Our analysis not only revealed a picture of a region that was dense with settlements, but it also revealed a lot of variability," Auld-Thomas states. "We didn't just find rural areas and smaller settlements. We also found a large city with pyramids right next to the area's only highway, near a town where people have been actively farming among the ruins for years.

"The government never knew about it; the scientific community never knew about it. That really puts an exclamation point behind the statement that, no, we have not found everything, and yes, there's a lot more to be discovered."

Future research will focus on fieldwork at the newly discovered sites, and could be instrumental in solving modern problems facing urban development.

"The ancient world is full of examples of cities that are completely different than the cities we have today," concludes Auld-Thomas. "There were cities that were sprawling agricultural patchworks and hyper-dense; there were cities that were highly egalitarian and extremely unequal.

"Given the environmental and social challenges we're facing from rapid population growth, it can only help to study ancient cities and expand our view of what urban living can look like. Having a larger sample of the human career, a longer record of the accumulated residue of people's lives, could give us the latitude to imagine better and more sustainable ways of being urban now and in the future."

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Dinosaurs thrived after ice, not fire, says a new study of ancient volcanism

Oct. 28, 2024, by Columbia Climate School

https://phys.org/news/2024-10-dinosaurs-ice-ancient-volcanism.html

Deposits in Morocco associated with the Triassic-Jurassic mass extinction, 201.6 million years ago. 

Red sediments in many locations around the world contain Triassic-era fossils. 

The white band on top of them is where the sediments were altered by massive volcanism, as evidenced by the gray/black basalt layers topping the assemblage.

 Credit: Paul Olsen/Lamont-Doherty Earth Observatory

201.6 million years ago, one of the Earth's five great mass extinctions took place, when three-quarters of all living species suddenly disappeared. The wipeout coincided with massive volcanic eruptions that split apart Pangaea, a giant continent then comprising almost all the planet's land. Millions of cubic miles of lava erupted over some 600,000 years, separating what are now the Americas, Europe and North Africa.

It marked the end of the Triassic period and the beginning of the Jurassic, the period when dinosaurs arose to take the place of Triassic creatures and dominate the planet.

The exact mechanisms of the End Triassic Extinction have long been debated, but most prominent: Carbon dioxide surfaced by the eruptions built up over many millennia, raising temperatures to unsustainable levels for many creatures, and acidifying the oceans.

But a new study says the opposite: cold, not warmth, was the main culprit. The study presents evidence that instead of stretching over hundreds of thousands of years, the first pulses of lava that ended the Triassic were stupendous events lasting less than a century each. The study was published in the journal Proceedings of the National Academy of Sciences.

In this condensed time frame, sunlight-reflecting sulfate particles were spewed into the atmosphere, cooling the planet and freezing many of its inhabitants. Gradually rising temperatures in an environment that was hot to begin with—atmospheric carbon dioxide in the late Triassic was already three times today's level—may have finished the job later on, but it was volcanic winters that did the most damage, say the researchers.

"Carbon dioxide and sulfates act not just in opposite ways, but opposite time frames," said lead author Dennis Kent of the Columbia Climate School's Lamont-Doherty Earth Observatory. "It takes a long time for carbon dioxide to build up and heat things, but the effect of sulfates is pretty much instant. It brings us into the realm of what humans can grasp. These events happened in the span of a lifetime."

The Triassic-Jurassic extinction has long been thought tied to the eruption of the so-called Central Atlantic Magmatic Province, or CAMP. In a groundbreaking 2013 study, Kent and colleagues provided perhaps the most definitive link. Kent, who studies paleomagnetism, identified a consistent polarity reversal in sediments just below the initial CAMP eruptions, which showed they all happened at the same time across what are now widespread parts of the world.

Colleagues then used radioactive isotopes to date the start of volcanism to 201,564,000 years ago, give or take a few tens of thousands of years. Scientists were unable to say how big the initial eruptions were, but it was assumed by many that the massive CAMP deposits must have taken many millennia to build up.

In the new study, Kent and colleagues correlated data from CAMP deposits in the mountains of Morocco, along Nova Scotia's Bay of Fundy, and New Jersey's Newark Basin. Their key evidence: the alignments of magnetic particles in the rocks that recorded the past drifting of Earth's magnetic pole at the time of the eruptions.

Due to a complex set of processes, this pole is offset from the planet's unchanging axis of rotation—true north—and to boot, changes position by a few tenths of a degree each year. (The reason that compasses do not point exactly north.)

Because of this phenomenon, magnetic particles in lavas that were emplaced within a few decades of each other will all point in the same direction, while ones emplaced, say, thousands of years later will point 20 or 30 degrees in a different direction.

What the researchers found was five successive initial CAMP lava pulses spread over about 40,000 years—each with the magnetic particles aligned in a single direction, indicating the lava pulse had emerged in less than 100 years, before drift of the magnetic pole could manifest itself.

They say that these huge eruptions released so many sulfates so quickly that the sun was largely blocked out, causing temperatures to plunge. Unlike carbon dioxide, which hangs around for centuries, volcanic sulfate aerosols tend to rain out of the atmosphere within years, so the resulting cold spells don't last very long. But due to the rapidity and size of the eruptions, these volcanic winters were devastating.

The researchers compared the CAMP series to sulfates from the 1783 eruption of Iceland's Laki volcano, which caused widespread crop failures; just the initial CAMP pulses were hundreds of times greater, they say.

In sediments just below the CAMP layers lie Triassic-era fossils: large terrestrial and semiaquatic relatives of crocodiles, strange tree lizards, giant, flat-headed amphibians, and many tropical plants. Then they disappear with the CAMP eruptions.

Small feathered dinosaurs had been around for tens of millions of years before this, and survived, eventually to thrive and get much larger, along with turtles, true lizards, and mammals, possibly because they were small and could survive in burrows.

"The magnitude of the environmental effects are related to how concentrated the events are," said study co-author Paul Olsen, a paleontologist at Lamont-Doherty.

"Small events spread out over [tens of thousands of years] produce much less of an effect than the same total volume of volcanism concentrated in less than a century. The overarching implication being that the CAMP lavas represent extraordinarily concentrated events."

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Ancient graves reveal distinct burial practices of Neanderthals and early humans in the Levant

Oct. 28, 2024 **feature**, by S. Oster , Phys.org

https://phys.org/news/2024-10-ancient-graves-reveal-distinct-burial.html

Early Homo sapiens burial examples including a double burial from Qafzeh Cave (#9-10) 

[A], an adult with a boar jaw (green) at Skhul 5 

[B], and an adolescent with deer antler (red) at Qafzeh 11 [C]. 

Credit: Been and Barzilai 2024. Prof. Bernard Vandermeersch.

A study published in L'Anthropologie by Professor Ella Been from Ono Academic College and Dr. Omry Barzilai from the University of Haifa sheds new light on the burial practices of Homo sapiens and Neanderthals in the Levant region during the Middle Paleolithic (MP).

The research, which examined a total of 17 Neanderthal and 15 Homo sapiens burials from various archaeological sites, revealed both similarities and differences in how these two species treated their dead, including differences in burial location, body posture and specific grave goods.

The MP in Western Asia, specifically the Levant, is of particular interest in the study of human evolution due to the co-existence of two hominin species at this time. While Homo sapiens arrived in the region between 170,000 and 90,000 years ago and re-entered the region 55,000 years ago from Africa, Neanderthals came into the Levant from Europe around 120,000 to 55,000 years ago.

During this time, both species suddenly began burying their dead, something neither species had done before. This suggests that burials were first innovated in the Levant before spreading or being autonomously innovated elsewhere.

The two species are easily distinguishable based on their biology and morphology, with nearly every bone in the body being unique to either species. However, their material culture, mobility and settlement patterns are nearly indistinguishable. Despite this, it was hypothesized that the two species may have had different burial practices.

It was a Neanderthal burial which inspired the current study, says Prof. Been, "A few years ago, my colleague Dr. Omry Barzilai and I published an article about the Neanderthals from Ein Qashish (EQ3). Initially, we were uncertain whether EQ3, which was found in an open-air site, was a burial.

"This uncertainty sparked our interest in Neanderthal burial practices, particularly in the Levant. Our current research has led us to the conclusion that EQ3 was indeed a deliberate burial. Additionally, we believe that examining burial practices might provide insight into the similarities and differences between H. sapiens and Neanderthals."

The study commenced by examining a number of sites in which Homo sapiens and Neanderthal skeletal remains were recovered. These included five Neanderthal sites; Teshik Tash, Shanidar, Dederiyeh, Amud, Tabun, and Kebara caves, and two Homo sapiens sites; Skhul Cave and Qafzeh Cave.

Based on the results of around 37 total confirmed burials, it was found that both Homo sapiens and Neanderthals buried their dead regardless of sex or age. However, Neanderthal infant burials were more common than Homo sapiens infants. Similarly, both species would sometimes include grave goods in the form of animal remains, including goat horns, deer antlers, mandibles and maxilla.

Despite these differences, the researchers also observed differences, indicating that not all aspects of H. sapiens and Neanderthal material culture were similar in the Levant as previously hypothesized.

Prof. Been elaborates on some of the differences observed, "In the Levant during MI6-MI3, we are not aware of H. sapiens burials within caves. All of their burials are in cave entrances or in rock shelters. Neanderthals, on the other hand, bury their dead inside the caves (except for EQ3, which was buried in an open-air site)."

Additionally, Homo sapiens burials were very uniform, usually laid out in a flexed (fetal-like) posture. This contrasts with the Neanderthal burials, which were more varied and included individuals buried in flexed, extended (straight), and semi-flexed positions while lying on their left, back, or right.

Furthermore, Neanderthals were more likely to include rocks in their burials, including placing a body between two large rocks as a form of positional marker or placing modified limestone pieces underneath the dead's heads as a sort of headrest.

Similarly, some aspects of burial were practiced by Homo sapiens but not by Neanderthals, such as having burials associated with ocher and marine shells, which were completely absent in Neanderthal contexts.

Interestingly, the researchers also noted a burial outburst during this time. Not only did burials suddenly appear, but they occurred at a very high rate in an equally condensed region, especially compared to later burials during the MP in Africa and Europe, of which there are only three in all of Africa and 27, albeit very spatially and temporarily separated for Neanderthals in all of Europe.

An increase in population density may partly explain this sudden boom in burials. Due to the increased humidity and, thus, a greater number of flora and fauna in the Saharo-Arabian desert around this time, Homo sapiens were attracted to the region from East Africa.

At the same time, melting glaciers in the Taurus and Balkan mountains opened up pathways to the south, enabling Neanderthals to enter the Levant. There, the two populations met, likely increasing population densities in the area and thus increasing demographic pressure and the presence of burials.

This trend of increased burials continued in the region until they suddenly stopped around 50,000 years ago; according to Prof. Been, "The most striking thing is that in later periods, humans in the Levant did not continue the practice of burials. After the Neanderthals went extinct around 50,000 years ago, cave burials ceased until the Late Paleolithic, around 15,000 years ago, during the Natufian culture, a semi-sedentary hunter-gatherer society."

The study by Professor Been and Dr. Barzilai not only sheds light on the burial practices of Homo sapiens and Neanderthals in the Levant during the MP but also raises intriguing questions about the cultural evolution of these two species.

"Burials are a significant part of culture, and we know that both Neanderthals and Homo sapiens had some form of culture. It's puzzling why both populations suddenly started burying their dead, rather than it being due to demographic pressure."

To better understand the differences and nuances in both Homo sapiens and Neanderthal culture and burials, Prof. Been will continue her research, at present, by styling a Neanderthal burial. She says, "I am currently studying Amud 7—a baby Neanderthal from Amud cave in Israel."

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One Gram of Salt Is The Difference For Millions of Heart Attacks

27 Oct. 2024, By D. NIELD

https://www.sciencealert.com/one-gram-of-salt-is-the-difference-for-millions-of-heart-attacks

(Jason Tuinstra/Unsplash)


We know consuming too much salt raises blood pressure, which in turn can lead to cardiovascular problems. A 2022 study has quantified this relationship as a public health message in clear, stark terms.

Looking at health data on adults in China, the study authors estimate that a reduction of just 1 gram in daily salt intake would be enough to prevent 9 million cases of stroke and heart attack between now and 2030.

With 4 million of those cases likely to be fatal, such a simple measure could save a lot of lives.

In China, average daily salt consumption sits at 11 grams, way above the 5 grams recommended by the World Health Organization (WHO). The researchers pulled together the latest stats on population size, salt consumption, blood pressure and disease rates.

"Previous estimations of the health impact of reducing salt intake in China used either obsolete or otherwise unreliable data sources and did not account for the more prolonged effect of salt reduction on blood pressure over several years," write the researchers in their published paper.

Consuming too much salt raises blood pressure, which in turn can lead to cardiovascular problems. (Prostock-studio/Canva)



The team looked at two other scenarios besides the single gram drop: a reduction of 3.2 grams per day (a 30 percent drop from the average) by 2025, and reducing salt intake to the recommended 5 grams per day by 2030.

If those targets are hit, up to twice as many deaths related to cardiovascular disease could be prevented, due to the estimated reduction in systolic blood pressure.

However, the researchers emphasize that the reduction would have to be consistent over several years. Education programs run in Chinese schools suggest most of the population wouldn't find it too difficult to hit that 1 gram per day target.

"Other trials, on low-sodium high-potassium salt substitutes, health education to home cooks and restaurant interventions are ongoing or have recently been completed, some of which have already shown promising results," write the researchers.

Potassium-enriched salt can look and taste like regular salt. (PixelsEffect/Canva)



Cardiovascular disease accounts for a massive 40 percent of deaths in China, with urbanization – and the associated increase in eating processed and takeaway foods – thought to be one of the main contributing factors.

While the authors of this study only looked at a potential reduction in cases of cardiovascular disease, they suggest that lowering salt intake would have multiple other benefits too. Too much salt has also been linked to certain types of cancers and various kidney problems, for example.

The Chinese government has launched a Healthy China 2030 campaign to try to hit its target of a daily salt intake of just 5 grams. That won't be easy with a population of 1.4 billion people, but the numbers produced in this study are compelling.

"A salt reduction programme that is workable, coherent, sustainable and targeting current and upcoming major dietary sources of salt in China is urgently needed," write the researchers.

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McDonald's Contamination Outbreak Spreads to 13 States as Cases Mount

28 October 2024, By AFP

https://www.sciencealert.com/mcdonalds-contamination-outbreak-spreads-to-13-states-as-cases-mount

(Ted Horowitz Photography/Getty Images)



A severe outbreak of E. coli linked to McDonald's Quarter Pounder burgers has expanded to 75 reported cases, mainly in the western United States, authorities said Friday.

The number of hospitalizations has risen to 22, though no additional deaths have been reported beyond that of an elderly patient in Colorado, according to the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC).

One child and one adult developed hemolytic uremic syndrome, a serious condition that damages blood vessels in the kidneys.

Investigators have yet to confirm a specific ingredient as the contamination source, though they are assessing whether slivered onions or beef patties could be the origin.

While the investigation is underway, Taylor Farms, which supplies the slivered onions to affected locations, has issued a voluntary recall of its yellow onions.

McDonald's restaurants in the 13 impacted states have temporarily pulled Quarter Pounders from their menus, though other items, including other beef burgers, remain available.

Shares of the fast-food giant dropped more than two percent in early afternoon trading.

Meanwhile, the law firms Ron Simon & Associates and Meyers & Flowers have filed lawsuits on behalf of two separate consumers from Colorado and Nebraska who fell ill after consuming the burgers.

Each suit seeks a minimum of $50,000 in damages, and attorney Ron Simon told AFP he plans to represent a total of 25 victims.

"When a consumer goes to McDonald's to buy a meal, they're placing an enormous amount of trust that McDonald's has done everything it can to make your food safe," said Simon.

"And here, whether it was faulty testing, faulty oversight, faulty handling, somehow poison got in that food, and trust is broken."

The CDC advised those who consumed a Quarter Pounder and developed symptoms of E. coli poisoning – such as diarrhea, bloody diarrhea, a fever over 102 degrees Fahrenheit (38.9 °C), and vomiting – to seek medical attention.

Symptoms typically begin three to four days after exposure, and most individuals recover within five to seven days without treatment. However, some cases can become severe and require hospitalization.

McDonald's said in a statement Tuesday it had taken "swift and decisive action" and that food safety was its "top priority."

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Rare fossils of extinct elephant document the earliest known instance of butchery in India

Oct. 21, 2024, by Florida Museum of Natural History

https://phys.org/news/2024-10-rare-fossils-extinct-elephant-document.html

a. Pampore elephant site.

 b. Elephant skull under excavation. 

Credit: Quaternary Science Reviews (2024). DOI: 10.1016/j.quascirev.2024.108894

During the late middle Pleistocene, between 300 and 400 thousand years ago, at least three ancient elephant relatives died near a river in the Kashmir Valley of South Asia. Not long after, they were covered in sediment and preserved along with 87 stone tools made by the ancestors of modern humans.

The remains of these elephants were first discovered in 2000 near the town of Pampore, but the identity of the fossils, cause of death and evidence of human intervention remained unknown until now.

A team of researchers including Advait Jukar, a curator of vertebrate paleontology at the Florida Museum of Natural History, published two new papers on fossils from the Pampore site. In one, researchers describe their discovery of elephant bone flakes which suggests that early humans struck the bones to extract marrow, an energy-dense fatty tissue. The findings are the earliest evidence of animal butchery in India. The research is published in the journal Quaternary Science Reviews.

The fossils themselves are also rare. In a second study published in the Journal of Vertebrate Paleontology, the researchers described the bones, which belong to an extinct genus of elephants called Palaeoloxodon, whose members were more than twice the weight of today's African elephants. Only one set of Palaeoloxodon bones for this species had been discovered previously, and the fossils from this study are by far the most complete.

To date, only one fossil hominin—the Narmada human—has ever been found on the Indian subcontinent. Its mix of features from older and more recent hominin species indicate the Indian subcontinent must have played an important role in early human dispersal. Prior to the fossil's discovery in 1982, paleontologists only had stone tool artifacts to give a rough sketch of our ancestors' presence on the subcontinent.

Scientists studied stone tools, bone flakes and rare elephant remains at a middle Pleistocene site. Their findings shed light on the evolution of giant elephants and humans alike. 

Credit: Chen Yu

"So, the question is, who are these hominins? What are they doing on the landscape and are they going after big game or not?" Jukar asked. "Now we know for sure, at least in the Kashmir Valley, these hominins are eating elephants."

The stone tools likely used for marrow extraction at the Pampore site were made with basalt, a type of rock not found in the local area. Paleontologists believe the raw materials were brought from elsewhere before being fully knapped, or shaped, at the site. Based on the method of construction, they concluded that the site and the tools were 300,000 to 400,000 years old.

Previously, the earliest evidence of butchery in India dated back less than ten thousand years.

"It might just be that people haven't looked closely enough or are sampling in the wrong place," Jukar said. "But up until now, there hasn't been any direct evidence of humans feeding on large animals in India."

Most of the Pampore site's elephant remains came from one mature male Palaeoloxodon. The inside of its skull showed abnormal bone growth that likely resulted from a chronic sinus infection.

While it was clear that early humans exploited the carcass, there was no direct evidence of hunting, such as spear points lodged in the bones. The hominins could have killed the elephant or simply found the carcass after it died of natural causes—weakened by its chronic sinus infection, the elephant could possibly have gotten stuck in the soft sediments near the Jhelum River, where paleontologists eventually found it.

The Palaeoloxodon skull is the most complete specimen of its genus found on the Indian subcontinent. Researchers identified it as belonging to the extinct elephant Palaeoloxodon turkmenicus, fossils of which have only been found on one other occasion, in 1955. This earliest fossil was of a partial skull fragment from Turkmenistan. While it looked different from other members of the genus Palaeoloxodon, there wasn't enough material to determine with certainty whether it was, in fact, a separate species.

"The problem with Palaeoloxodon is that their teeth are largely indistinguishable between species. So, if you find an isolated tooth, you really can't tell what species of Palaeoloxodon it belongs to," Jukar said. "You have to look at their skulls."

Fortunately, the Pampore specimen's hyoids—bones at the back of the throat that attach to the tongue—were still intact. Hyoids are fragile but distinctive between species, providing a special tool for taxonomizing.

Palaeoloxodon originated in Africa about a million years ago before dispersing into Eurasia. Many species in the genus are known for having an unusually large forehead unlike that of any living elephant species, with a crest that that bulges out over their nostrils. Earlier species of Palaeoloxodon from Africa, however, do not have the bulge. Meanwhile, P. turkmenicus is somewhere in between, with an expanded forehead with no crest.

"It shows this kind of intermediate stage in Palaeoloxodon evolution," Jukar said. "The specimen could help paleontologists fill in the story of how the genus migrated and evolved."

Given that hominins have been eating meat for millions of years, Jukar suspects that a lot more evidence of butchery is simply waiting to be found.

"The thing I've come to realize after many years is that you just need a lot more effort to go and find the sites, and you need to essentially survey and collect everything," he said. "Back in the day when people collected fossils, they only collected the good skulls or limb bones. They didn't collect all the shattered bone, which might be more indicative of flakes or breakage made by people."

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