The puzzle of the galaxy with no dark matter

A team of scientists, led by the researcher at the IAC and the University of La Laguna (ULL) Sebastién Comerón, has found that the galaxy NGC 1277 does not contain dark matter.This is the first time that a massive galaxy (it has a mass several times that of the Milky Way) does not show evidence for this invisible component of the universe. "This result does not fit in with the currently accepted cosmological models, which include dark matter" explains Comerón.

In the current standard model cosmology massive galaxies contain substantial quantities of dark matter, a type of matter which does not interact in the same way as normal matter; the only evidence for its existence is the strong gravitational pull which it exerts on the stars and the gas nearby, and this interacton is observable.

NGC 1277 is considered a prototype "relic galaxy" which means a galaxy which has had no interactions with its neighbours. Galaxies of this type are very rare, and they are considered the remnants of giant galaxies which formed in the early days of the universe.

"The importance of relic galaxies in helping us to understand how the first galaxies formed was the reason we decided to observe NGC 1277 with an integral field spectrograph" explains Comerón. "From the spectra we made kinematic maps which enabled us to work out the distribution of mass within the galaxy out to a radius of some 20,000 light years" he adds.

The team discovered that the mass distribution in NGC 1277 was just the distribution of the stars, and from this they inferred that within the radius observed there cannot be more than 5% of dark matter, although the observations are consistent with the complete absence of this component.

However, present cosmological models predict that a galaxy with the mass of NGC 1277 should have at least 10 % of their mass in the form of dark matter, with a maximum of 70 % in this form. "This discrepancy between the observations and what we would expect is a puzzle, and maybe even a challenge for the standard model" notes Ignacio Trujillo, a researcher at the IAC and the ULL, who participated in the study.

The article suggests two possible explanations for the lack of dark matter in NGC 1277. "One is that the gravitational interaction with the surrounding medium within the galaxy cluster in which this galaxy is situated has stripped out the dark matter" comments Anna Ferré-Mateu, a researcher at the IAC and the ULL who also participated in the study. "The other is that the dark matter was driven out of the system when the galaxy formed by the merging of protogalactic fragments, which gave rise to the relic galaxy."

For the authors of the study neither of these explanations is fully satisfactory "so the puzzle of how a massive galaxy can form without dark matter remains a puzzle" insists Comerón. In order to continue researching the mystery the team plans to make new observations with the WEAVE instrument on the William Herschel Telescope (WHT) at the Roque de los Muchachos Observatory, in the Canary Island of La Palma.

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Early humans were weapon woodwork experts, study finds

A 300,000-year-old hunting weapon has shone a new light on early humans as woodworking masters, according to a new study.

State-of-the-art analysis of a double-pointed wooden throwing stick, found in Schöningen in Germany three decades ago, shows it was scraped, seasoned and sanded before being used to kill animals. The research indicates early humans' woodworking techniques were more developed and sophisticated than previously understood.

The findings, published today (Wednesday, 19 July) in PLOS ONE, also suggest the creation of lightweight weapons may have enabled group hunts of medium and small animals. The use of throwing sticks as hunting aids could have involved the entire community, including children.

Dr Annemieke Milks, of the University of Reading's Department of Archaeology, led the research. She said: "Discoveries of wooden tools have revolutionised our understanding of early human behaviours. Amazingly these early humans demonstrated an ability to plan well in advance, a strong knowledge of the properties of wood, and many sophisticated woodworking skills that we still use today.

"These lightweight throwing sticks may have been easier to launch than heavier spears, indicating the potential for the whole community to take part. Such tools could have been used by children while learning to throw and hunt."

Co-author Dirk Leder said: "The Schöningen humans used a spruce branch to make this aerodynamic and ergonomic tool. The woodworking involved multiple steps including cutting and stripping off the bark, carving it into an aerodynamic shape, scraping away more of the surface, seasoning the wood to avoid cracking and warping, and sanding it for easier handling."

High-impact weapon

Found in 1994, the 77cm-long stick is one of several different tools discovered in Schöningen, which includes throwing spears, thrusting spears and a second similarly sized throwing stick.

The double-pointed throwing stick -- analysed to an exceptionally high level of detail for this new study -- was most likely used by early humans to hunt medium-sized game like red and roe deer, and possibly fast-small prey including hare and birds that were otherwise difficult to catch. The throwing sticks would have been thrown rotationally -- similar to a boomerang -- rather than overhead like a modern-day javelin and may have enabled early humans to throw as far as 30 metres. Although lightweight, the high velocities at which such weapons can be launched could have resulted in deadly high-energy impacts.

The fine surface, carefully shaped points and polish from handling suggest this was a piece of personal kit with repeated use, rather than a quickly made tool that was carelessly discarded.

Principal investigator Thomas Terberger said: "The systematic analysis of the wooden finds of the Schöningen site financed by German Research Foundation provides valuable new insights and further exciting information on these early wooden weapons can be expected soon."

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Life on Earth didn't arise as described in textbooks

No, oxygen didn't catalyze the swift blossoming of Earth's first multicellular organisms. The result defies a 70-year-old assumption about what caused an explosion of oceanic fauna hundreds of millions of years ago.

Between 685 and 800 million years ago, multicellular organisms began to appear in all of Earth's oceans during what's known as the Avalon explosion, a forerunner era of the more famed Cambrian explosion. During this era, sea sponges and other bizarre multicellular organisms replaced small single-celled amoeba, algae and bacteria, which until then, had had run of the planet for more than 2 billion years.

Up until now, it was believed that increased oxygen levels triggered the evolutionary arrival of more advanced marine organisms. This is being disproved by University of Copenhagen researchers working together with colleagues from Woods Hole Oceanographic Institute, the University of Southern Denmark and Lund University, among others.

By studying the chemical composition of ancient rock samples from an Omani mountain range, the researchers have been able to "measure" oxygen concentrations in the world's oceans from when these multicellular organisms appeared. Defying expectations, the result shows that Earth's oxygen concentrations had not increased. Indeed, levels remained 5-10 times lower than today, which is roughly how much oxygen there is at twice the height of Mount Everest.

"Our measurements provide a good picture of what average oxygen concentrations were in the world's oceans at the time. And it's apparent to us that there was no major increase in the amount of oxygen when more advanced fauna began to evolve and dominate Earth. In fact, there was somewhat of a slight decrease," says Associate Professor Christian J. Bjerrum, who has been quantifying the conditions surrounding the origin of life for the past 20 years.

Revises our understanding of life's origins

The new result puts to rest a 70-year research story that advances the centrality of higher oxygen concentrations in the development of more advanced life on our planet.

"The fact that we now know, with a high degree of certainty, that oxygen didn't control the development of life on Earth provides us with an entirely new story about how life arose and what factors controlled this success," says the researcher, adding:

"Specifically, it means that we need to rethink a lot of the things that we believed to be true from our childhood learning. And textbooks need to be revised and rewritten."

There remains much that the researchers don't know, as well as and a plethora of controversy. Therefore, Bjerrum hopes that the new result can spur other researchers around the world to reconsider their previous results and data in a new light.

"There are many research sections around the world, including in the United States and China, that have done lots of research on this topic, whose earlier results may shed important new details if interpreted on the basis that oxygen didn't drive the development of life," says the researcher.

Absence of oxygen may have aided development

So, if not extra oxygen, what triggered the era's explosion of life? Perhaps the exact opposite, explains the researcher:

"It's interesting that the explosion of multicellular organisms occurs at a time with low concentrations of atmospheric and oceanic oxygen. That indicates that organisms benefited from lower levels of oxygen and were able to develop in peace, as the water chemistry protected their stem cells naturally," says Christian J. Bjerrum.

According to the researcher, the same phenomenon has been studied in cancer research, in the stem cells of humans and other animals. Here, colleagues at Lund University observed that low oxygen levels are crucial for keeping stem cells under control until an organism decides that the cell ought to develop into a specific type of cell, such as a muscle cell.

"We know that animals and humans must be able to maintain low concentrations of oxygen in order to control their stem cells, and in so doing, develop slowly and sustainably. With too much oxygen, the cells will develop, and in the worst case, mutate wildly and perish. It is far from inconceivable that this mechanism applied back then," concludes Christian J. Bjerrum.

Fossils from Oman

In the new study, the researchers analysed rock samples from, among other places, the Oman Mountains in northern Oman. While quite high and very dry today, the mountains were on the seabed during the Avalon explosion's rapid blossoming of organism diversity.

The researchers have had their findings confirmed in fossils from three different mountain ranges around the world: the Oman Mountains (Oman), Mackenzie Mountains (NW Canada) and the Yangtze Gorges area of South China.

Over time, clay and sand from land are washed into the sea, where they settle into layers on the seabed. By going down through these layers and examining their chemical composition, researchers can get a picture of ocean chemistry at a particular geologic time.

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Unlocking the power of molecular crystals: A possible solution to nuclear waste

In a world increasingly concerned about the environmental and geopolitical implications of fossil fuel usage, nuclear energy has resurfaced as a subject of great interest. Its ability to generate electricity at scale without greenhouse gas emissions holds promise as a sustainable clean energy source that could bridge society's transition away from fossil fuels to a net-zero future. However, nuclear power generation does produce radioactive waste. The safe management of nuclear waste remains a crucial challenge that must be addressed to gain public confidence in this transformative power solution.

Now, a team of University of Houston researchers has come up with an innovative solution for nuclear waste management: molecular crystals based on cyclotetrabenzil hydrazones. These crystals, which are based on a groundbreaking discovery made by the team in 2015, are capable of capturing iodine -- one of the most common radioactive fission products -- in aqueous and organic solutions, and on the interface between the two.

"This last point is particularly salient because iodine capture on interfaces could prevent the iodine from reaching and damaging the specialized paint coatings used in nuclear reactors and waste containment vessels," said Ognjen Miljanic, professor of chemistry and corresponding author of the paper detailing the breakthrough in Cell Reports Physical Science.

These crystals exhibit an astonishing iodine uptake capacity, rivaling that of porous metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), which were previously deemed the pinnacle of iodine capture materials.

Alexandra Robles, the first author of the study and a former doctoral student who based her dissertation on this research, was working with the crystals in Miljanic's lab when she made the discovery. Her interest in finding a solution for nuclear waste led Robles to investigate using crystals to capture iodine.

"She ended up capturing iodine on the interface between the organic and water layers, which is an understudied phenomenon," said Miljanic, who added that this exceptional feature provides a crucial advantage. "When the material is deposited between the organic and aqueous layer, it essentially stops the transfer of iodine from one layer to another."

Not only does this process preserve integrity of reactor coatings and enhance containment, but the captured iodine could also then be moved from one area to another. "The idea here is that you capture it at a place where it's difficult to manage, and then you release it at a place where it's easy to manage," Miljanic said.

The other benefit of this catch-and-release technology is that the crystals can be reused. "If the pollutant just sticks to the regent, the whole thing has to be thrown away," he said. "And that increases waste and economic loss."

Of course, all of these great potentials still need to be tested in practical applications, which has Miljanic thinking of the next steps.

Molecules, Crystals and Octopuses, Oh My!

Miljanic's team creates these tiny organic molecules containing only carbon, hydrogen and oxygen atoms using commercially available chemicals.

Each crystal is a ring-shaped structure with eight linear piece emanating from it, which has led the research team to nickname it "The Octopus."

"They are quite easy to make and can be produced at a large scale from relatively inexpensive materials without any special protective atmosphere," said Miljanic.

He estimated that he can currently produce these crystals at the cost of about $1 per gram in an academic lab. In an industrial setting, Miljanic believes the cost would drop significantly.

These hungry little crystals are very versatile and can capture more than iodine. Miljanic and his team have used some of them to capture carbon dioxide, which would be another great step toward a cleaner, more sustainable world. In addition, "The Octopus" molecules are closely related to those found in materials used to make lithium-ion batteries, which opens the door to other energy opportunities.

"This is a type of simple molecule that can do all sorts of different things depending on how we integrate it with the rest of any given system," Miljanic said. "So, we're pursuing all those applications as well."

He is excited by the multitude of potential offered by the crystals and looking forward to exploring practical applications. His next goal is to find a partner who will help the scientists explore different commercial aspects.

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VERA unveils surroundings of rapidly growing black holes

An international team of astronomers used the state-of-the-art capability of VERA, a Japanese network of radio telescopes operated by NAOJ, to uncover valuable clues about how rapidly growing "young" supermassive black holes form, grow, and possibly evolve into more powerful quasars.

It is now widely accepted that nearly every active galaxy harbors a supermassive black hole at its core, with masses ranging from millions to billions of times that of the Sun. The growth history by which these black holes have gained such huge masses, however, remains an open question.

Led by Mieko Takamura, a graduate student at the University of Tokyo, an international team focused on a distinct category of active galaxies known as Narrow-line Seyfert 1 (NLS1) galaxies. These galaxies are suspected to contain relatively small yet rapidly growing massive black holes, thus offering a potential opportunity to study an early evolutionary stage of these cosmic monsters. To gain a deeper understanding of the immediate surroundings of these peculiar black holes, the team observed the cores of six nearby active NLS1 galaxies using VERA -- a radio telescope network with an eyesight over 100,000 times more powerful than the human eye. In particular, the team leveraged the newly enhanced ultra-wideband recording capability of VERA, enabling them to detect faint "polarized" radio waves emanating from the core of these galaxies with unprecedented precision.

A portion of radio waves emitted near supermassive black holes is known to exhibit polarization. As this polarized emission propagates through the magnetized gas surrounding the black hole, the plane of polarization gradually rotates, causing an effect known as Faraday rotation. The extent of this rotation (at a given wavelength) is proportional to the gas density and the strength of the magnetic field within the propagating medium. Therefore, polarization and Faraday rotation provide valuable insights into the immediate environment surrounding a central black hole.

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Gene mutation may explain why some don't get sick from COVID-19

People who contract COVID-19 but never develop symptoms -- the so-called super dodgers -- may have a genetic ace up their sleeve. They're more than twice as likely as those who become symptomatic to carry a specific gene variation that helps them obliterate the virus, according to a new study led by UC San Francisco researchers. 

The paper, published July, 19, 2023 in Nature, offers the first evidence that there is a genetic basis for asymptomatic SARS-CoV-2. The research helps to solve the mystery of why some people can be infected without ever getting sick from COVID-19. 

The secret lies with the human leukocyte antigen (HLA), or protein markers that signal the immune system. A mutation in one of the genes coding for HLA appears to help virus-killing T cells identify SARS-CoV-2 and launch a lighting attack. The T cells of some people who carry this variant can identify the novel coronavirus, even if they have never encountered it before, thanks to its resemblance to the seasonal cold viruses they already know. The discovery points to new targets for drugs and vaccines.

"If you have an army that's able to recognize the enemy early, that's a huge advantage," explained the study's lead researcher, Jill Hollenbach, PhD, MPH, professor of neurology, as well as epidemiology and biostatistics, and a member of the Weill Institute for Neurosciences at UCSF. "It's like having soldiers that are prepared for battle and already know what to look for, and that these are the bad guys." 

The mutation -- HLA-B*15:01 -- is quite common, carried by about 10% of the study's population. It doesn't prevent the virus from infecting cells but, rather, prevents people from developing any symptoms. That includes a runny nose or even a barely noticeable sore throat. 

UCSF researchers found that 20% of people in the study who remained asymptomatic after infection carried at least one copy of the HLA-B*15:01 variant, compared to 9% of those who reported symptoms. Those who carried two copies of the variant were far more likely -- more than eight times -- to avoid feeling sick.

Leveraging a national marrow donor database

Researchers suspected early on that HLA was involved, and fortunately a national registry existed that contained the data they were looking for. The National Marrow Donor Program/Be The Match, the largest registry of HLA-typed volunteer donors in the U.S., matches donors with people who need bone marrow transplants.

But they still needed to know how the donors fared against COVID-19. So, they turned to a mobile app developed at UCSF, called the COVID-19 Citizen Science Study. They recruited nearly 30,000 people who were also in the bone marrow registry and tracked through the first year of the pandemic. At that time, vaccines were not yet available, and many people were undergoing routine COVID testing for work or whenever they were potentially exposed.

"We did not set out to study genetics, but we were thrilled to see this result come from our multidisciplinary collaboration with Dr. Hollenbach and the National Marrow Donor Program," said Mark Pletcher, MD, MPH, a professor of epidemiology and biostatistics at UCSF.

The primary study group was limited to those who self-identified as white because the final set of study respondents did not have enough people in it from other ethnic and racial groups to analyze.

Researchers identified 1,428 unvaccinated donors who tested positive between February 2020 and the end of April 2021, before the vaccines were widely available and when it still took many days to get back test results.

Of these, 136 individuals remained asymptomatic for at least two weeks before and after testing positive. Only one of the HLA variants -- HLA-B*15:01 -- had a strong association with asymptomatic COVID-19 infection, and this was reproduced in two independent cohorts. Risk factors for severe COVID-19, like being older, overweight and having chronic diseases like diabetes did not appear to play a role in who remained asymptomatic.   

"We are proud to partner on research that has the potential to leverage a long-term public investment in building the national registry to help cure diseases and improve our ability to avoid future pandemics," said Martin Maiers, vice president of research at the National Marrow Donor Program/Be The Match.

To figure out how HLA-B15 managed to quash the virus, Hollenbach's team collaborated with researchers from La Trobe University in Australia. They homed in on the concept of T-cell memory, which is how the immune system remembers previous infections. 

The researchers looked at T cells from people who carried HLA-B15 but had never been exposed to the SARS-CoV-2 virus, and found these cells still responded to a part of the novel coronavirus called the NQK-Q8 peptide. They concluded that exposure to some seasonal coronaviruses, which have a very similar peptide, called NQK-A8, enabled T cells in these individuals to quickly recognize SARS-CoV-2 and mount a faster, more effective immune response.

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'Mind controlling' parasitic worms are missing genes found in every other animal

In a world full of bizarre animals, hairworms are some of the strangest: parasitic worms that manipulate the behavior of their hosts in what's sometimes called "mind control." A new study in the journal Current Biology reveals another strange trait shared by different hairworm species: they're missing about 30% of the genes that researchers expected them to have. What's more, the missing genes are responsible for the development of cilia, the hair-like structures present in at least some of the cells of every other animal known.

Hairworms are found all over the world, and they look like skinny strands of spaghetti, a couple inches long. Their simple bodies hint at their parasitic lifestyle -- they have no excretory, respiratory, or circulatory systems, and they spend almost their entire lives inside the bodies of other animals. "One of the coolest things, maybe the thing that they are most known for, is that they can affect the behavior of their hosts and make them do things that they wouldn't do otherwise," says Tauana Cunha, a postdoctoral researcher at Chicago's Field Museum and lead author of the study done in collaboration with Harvard University and the University of Copenhagen.

There are a few hundred species of freshwater hairworms. Their eggs hatch in water, and the hairworm larvae get eaten by tiny water-dwelling predators like mayfly larvae, which in turn get eaten by bigger, land-dwelling predators like crickets. After growing into adulthood inside of their new hosts' bodies, the hairworms manipulate the hosts' behavior, causing them to jump into water. There, the worms swim out of their hosts' butts and seek out mates, knotting themselves together, to begin the cycle anew. (There are also five species of hairworms that live in marine environments and parasitize water-dwelling creatures like lobsters, but it's not clear if those ones also have host manipulation capabilities -- there's no pressure for the worms to get back to the water, since the hosts already live there.)

As strange as hairworms' behavior is, Cunha's research interest in the animals has more to do with their DNA. "We set out to sequence their genomes, because nothing like them has ever been sequenced before at that level," she says of the study conducted with her co-authors Bruno de Medeiros, Arianna Lord, Martin Sørensen, and Gonzalo Giribet. "The goal was to produce those genomes and eventually use them to understand the evolutionary relationships between hairworms and other kinds of animals."

She and her colleagues took DNA samples from two hairworm species -- one freshwater and one saltwater -- and sequenced them. But when they compared the hairworms' genetic codes to those of other animals, they found something striking.

"What we found, which was very surprising, was that both hairworm genomes were missing about 30% of a set of genes that are expected to be present across basically all groups of animals," says Cunha.

Results like that often make scientists wonder if they've made a mistake. But there was a connection between the missing genes in the two worm species. "The large majority of the missing genes were exactly the same between the two species. This was just implausible by chance," says Cunha.

By looking at what functions these missing genes are responsible for in other animal groups, Cunha and colleagues showed that they give the instructions for producing cilia. "Cilia are organelles, small structures at the cellular level, that are basically present across all animals and even more broadly, in protists and some plants and fungi. So they're present across a large diversity of life on Earth," says Cunha. They're present in many of the cells in the human body: for instance, the tails of sperm cells are cilia, and cells in the retinas of our eyes have cilia too.

Previously, scientists had found that hairworms seemed to be missing cilia where they'd normally be found. Hairworm sperm, for example, do not have tails. But while no one had ever seen a ciliated cell from a hairworm, that wasn't considered definitive proof that they didn't have them. It's hard to prove something with negative evidence. "Without the genomes, this would require looking at all cells in all life stages in all species," says Bruno de Medeiros, Curator of Pollinating Insects at the Field Museum and co-author of the paper.

"Based on previous observations, it didn't seem like hairworms had any cilia, but we didn't really know for sure," says Cunha. "Now with the genomes, we saw that they actually lack the genes that produce cilia in other animals -- they don't have the machinery to make cilia in the first place."

What's more, the fact that both the freshwater and marine hairworm species had lost the genes for cilia indicates that this evolutionary change happened in the deep past to the two species' common ancestor. "It is likely that the loss happened early on in the evolution of the group, and they just have been carrying on like that," says Cunha.

The finding opens the door to several new questions. It's not clear how the lack of cilia have affected hairworms, or if the hairworms' parasitic behavior could be related to the missing cilia. "There are plenty of other parasitic organisms that aren't missing these specific genes, so we cannot say that the genes are missing because of their parasitic lifestyle," says Cunha. "But parasitic organisms in general are often missing lots of genes. It's hypothesized that because parasites are not using certain structures and instead rely on their hosts, they end up losing those structures."

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Unusual fossil shows rare evidence of a mammal attacking a dinosaur

Canadian and Chinese scientists have described an unusual fossil from around 125 million years ago that shows a dramatic moment in time when a carnivorous mammal attacked a larger plant-eating dinosaur.

"The two animals are locked in mortal combat, intimately intertwined, and it's among the first evidence to show actual predatory behaviour by a mammal on a dinosaur," explains Dr. Jordan Mallon, palaeobiologist with the Canadian Museum of Nature and co-author on the study published today in the journal Scientific Reports.

The fossil's presence challenges the view that dinosaurs had few threats from their mammal contemporaries during the Cretaceous, when dinosaurs were the dominant animals. The rare fossil is now in the collections of the Weihai Ziguang Shi Yan School Museum in China's Shandong Province.

The dinosaur in the well-preserved fossil is identified as a species of Psittacosaurus, which is about the size of a large dog. Plant-eating psittacosaurs are among the earliest known horned dinosaurs and lived in Asia during the Early Cretaceous, from around 125 to 105 million years ago. The mammal in the fossil pair is a badger-like animal, called Repenomamus robustus. Although not large by dinosaur standards, it was among the largest mammals during the Cretaceous, at a time when mammals had not yet come to dominate the Earth.

Prior to this discovery, palaeontologists knew that Repenomamus preyed on dinosaurs including Psittacosaurus because of fossilized baby bones of the herbivore found in the mammal's stomach.

"The co-existence of these two animals is not new, but what's new to science through this amazing fossil is the predatory behaviour it shows," says Mallon.

The fossil was collected in China's Liaoning Province in 2012, and both skeletons are nearly complete. Their completeness is due to the fact that they come from an area known as the Liujitun fossil beds, which have been dubbed "China's Dinosaur Pompeii."

The name refers to the many fossils of dinosaurs, small mammals, lizards and amphibians in the area, animals that were buried suddenly en masse by mudslides and debris following one or more volcanic eruptions. The existence of volcanic material in the rock matrix of the study's fossil was confirmed following analysis by Canadian Museum of Nature mineralogist Dr. Aaron Lussier.

The Psittacosaurus-Repenomamus fossil was in the care of study co-author Dr. Gang Han in China, who brought it to the attention of Canadian Museum of Nature palaeobiologist Xiao-Chun Wu. Dr. Wu has worked with researchers in China for decades and knew it was special when he saw it.

A close examination of the fossil pair shows that the Psittacosaurus is lying prone, with its hindlimbs folded on either side of its body. The body of the Repenomamus coils to the right and sits atop its prey, with the mammalgripping the jaw of the larger dinosaur. The mammal is also biting into some of the ribs, and the back foot of Repenomamus is gripping onto the dino's hind leg. "The weight of the evidence suggests that an active attack was underway," says Dr. Mallon.

Mallon, Wu and colleagues ruled out the possibility that the mammal was simply scavenging a dead dinosaur. The bones of the dinosaur have no tooth marks, for example, suggesting it was not being scavenged, but rather was being preyed upon. And it's unlikely the two animals would have become so entangled if the dinosaur had been dead before the mammal came upon it. The position of the Repenomamus over top of the Psittacosaurus suggests it was also the aggressor.

Analogies of smaller animals attacking larger prey are known in the modern world. Mallon and Wu note that some lone wolverines are known to hunt larger animals, including caribou and domestic sheep. And on the African savanna, wild dogs, jackals and hyenas will attack prey that are still alive, with the prey collapsing, often in a state of shock.

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Astronomers discover striking evidence of 'unusual' stellar evolution

Astronomers have found evidence that some stars boast unexpectedly strong surface magnetic fields, a discovery that challenges current models of how they evolve.

In stars like our sun, surface magnetism is linked to stellar spin, a process similar to the inner workings of a hand-cranked flashlight. Strong magnetic fields are seen in the hearts of magnetic sunspot regions, and cause a variety of space weather phenomena. Until now, low-mass stars -- celestial bodies of lower mass than our sun that can rotate either very rapidly or relatively slowly -- were thought to exhibit very low levels of magnetic activity, an assumption which has primed them as ideal host stars for potentially habitable planets.

In a new study, published today in The Astrophysical Journal Letters, researchers from The Ohio State University argue that a new internal mechanism called core-envelope decoupling -- when the surface and core of the star start out spinning at the same rate, then drift apart -- might be responsible for enhancing magnetic fields on cool stars, a process which could intensify their radiation for billions of years and impact the habitability of their nearby exoplanets.

The research was made possible due to a technique that Lyra Cao, lead author of the study and a graduate student in astronomy at Ohio State, and co-author Marc Pinsonneault, a professor of astronomy at Ohio State, developed earlier this year to make and characterize starspot and magnetic field measurements.

Although low-mass stars are the most common stars in the Milky Way and are often hosts to exoplanets, scientists know comparatively little about them, said Cao.

For decades, it was assumed that the physical processes of lower mass stars followed those of solar-type stars. Because stars gradually lose their angular momentum as they spin down, astronomers can use stellar spins as a device to understand the nature of a star's physical processes, and how they interact with their companions and their surroundings. However, there are times where the stellar rotation clock appears to stop in place, Cao said.

Using public data from the Sloan Digital Sky Survey to study a sample of 136 stars in M44, a star crib also known as Praesepe, or the Beehive cluster, the team found that the magnetic fields of the low-mass stars in the region appeared much stronger than current models could explain.

While previous research revealed that the Beehive cluster is home to many stars that defy current theories of rotational evolution, one of Cao's team's most exciting discoveries was determining that these stars' magnetic fields may be just as unusual -- far stronger than predicted by current models.

"To see a link between the magnetic enhancement and rotational anomalies was incredibly exciting," said Cao. "It indicates that there might be some interesting physics at play here." The team also hypothesized that the process of syncing up a star's core and the envelope might induce a magnetism found in these stars that would have a starkly different origin from the kind seen on the sun.

"We're finding evidence that there's a different kind of dynamo mechanism driving the magnetism of these stars," said Cao. "This work shows that stellar physics can have surprising implications for other fields."

According to the study, these findings have important implications for our understanding of astrophysics, particularly on the hunt for life on other planets. "Stars experiencing this enhanced magnetism are likely going to be battering their planets with high-energy radiation," Cao said. "This effect is predicted to last for billions of years on some stars, so it's important to understand what it might do to our ideas of habitability."

But these findings shouldn't put a damper on the search for extraplanetary existence. With further research, the team's discovery could help provide more insight into where to look for planetary systems capable of hosting life. But here on Earth, Cao believes her team's discoveries might lead to better simulations and theoretical models of stellar evolution.

"The next thing to do is verify that enhanced magnetism happens on a much larger scale," said Cao. "If we can understand what's going on in the interiors of these stars as they experience shear-enhanced magnetism, it's going to lead the science in a new direction."

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New fossil flying reptile 'Elvis' takes flight

A new 145-million-year-old pterosaur (extinct flying reptiles that lived alongside the dinosaurs) was named today by a team of British, American and German researchers. The animal was nicknamed 'Elvis' when the fossil was first unearthed in Bavaria, Germany because of the giant pompadour-like bony crest on its skull.

Now the animal has been given a formal scientific name of Petrodactyle wellnhoferi. The name translates as 'Wellnhofer's stone-finger' honouring legendary German palaeontologist Peter Wellnhofer who spent his career working on German pterosaurs. Petrodactyle is a member of a group of pterosaurs called the ctenochasmatids that were mostly small filter feeders. Petrodactyle is a very complete skeleton with nearly every bone preserved and in remarkable detail.

Many pterosaurs are known with bony crests which they used primarily as sexual signals to other members of the species, but Pterodactyle has by far the largest crest even seen in a ctenochasmatid. Dr David Hone of Queen Mary University of London was the lead author on the study said, "Big though this crest is, we know that these pterosaurs had skin-like extensions attached to it, so in life Petrodactyle would have had an even larger crest."

The details of the specimen are especially clear under UV light which helps show the difference between the bones and the rock in which they are embedded, which under natural light are a very similar colour. René Lauer of the Lauer Foundation, an author on the study said, "The use of UV Induced Fluorescence digital photography provided the ability to discern fine structures small bones and provided additional information regarding the structures of the bony crest which aided in the interpretations and conclusions of this unique new species."

Petrodactyle was unusually large too. It has a wingspan of around 2 meters, but it was still an older 'teenager' by pterosaur standards and would have been even larger as a fully mature animal. Even so, it is one of the largest pterosaurs known from the Late Jurassic period. Bruce Lauer of the Lauer Foundation, an author on the study said "The specimen was located in a quarry which is producing scientifically important fossils that provide additional insights into Late Jurassic Pterosaurs. This research is a great example of the benefits of cooperation between amateur collectors, commercial fossil dealers, our Foundation and research scientists to advance science."

Like other ctenochasmatids, Petrodactyle was at home on the shore of shallow seas but might have ventured into estuaries or to lakes. It's long jaw with many small teeth would have been good for grabbing at small fish, shrimp and other aquatic prey. However, unlike most other ctenochasmatids, it had an expansion at the back of the skull to attach large jaw muscles and give it a stronger bite than many of its contemporaries. Frederik Spindler of the Dinosaurier Museum in Germany, an author on the study said, "It is amazing to document an increasingly wide range of adaptations. Pterosaurs were a fundamental part of the Jurassic ecology."

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What causes mudslides and floods after wildfires? Hint: It's not what scientists thought

In 2020, one of the largest wildfires in Los Angeles County raged across the San Gabriel Mountains, scorching more than 115,000 acres, damaging or destroying over 150 structures and raining ash and smoke down on pandemic-weary Angelenos.

But even after exhausted firefighters had finally snuffed out the flames, the Bobcat Fire -- like other so-called "mega-fires" that have become more common due to climate change -- carried the potential to wreak more havoc in its wake. As rainstorms deluge burnt areas, flooding, mudslides and debris flow can compound the fire's damage.

Understanding how water accumulates and monitoring the movement of runoff and streamflow in burn areas helps authorities predict when and where these post-wildfire events might occur so they can provide affected residents with early warning of flash flooding and debris movement.

A slippery slope

Common knowledge has long held that loss of vegetation during a fire leaves soil vulnerable to erosion because the plant roots that hold the soil in place wither and die. Scientists, however, have long held a different view, that as leaves burn, their waxy coating forms an organic, oily substance on the soil's surface. This waxy coating creates a water-repellant layer at or near the surface. Scientists believed this layer prevented the ground from absorbing water, resulting in rapid water runoff akin to a Slip 'N Slide that carries mud and debris.

New research published in Nature Communications has called that scientific theory into question.

A watershed finding

Images of the 2020 Bobcat Fire area indicate soil burn severity and the locations the researchers studied. (Image Source: a- USDA Forest Service; b- A.J. West; d- Pléiades ©CNES, Distribution AIRBUSDS, sourced via SkyWatch Space Applications Inc., and USGS 3D Elevation Program.)

Scientists at the USC Dornsife College of Letters, Arts and Science, in collaboration with researchers from the University of Michigan, the U.S. Geological Survey and Rutgers University, monitored two wet seasons following the Bobcat Fire, from December 2020 to March 2022. The team concluded that water was, in fact, being absorbed by the burnt ground that contained this waxy coating.

Specifically, the team studied three watersheds -- areas of land that drain rainfall and snowmelt into streams and rivers -- in Southern California's San Gabriel Mountains. Two of the watersheds burned during the 2020 Bobcat Fire and the other was mainly untouched.

The researchers found that post-wildfire, a significant portion of the water flow in all three watersheds came from water that had been absorbed in the ground.

Joshua West, professor of Earth sciences who led the study at USC Dornsife, said it was no surprise that the flow of water and debris in the burned area's stream was four to 10 times greater than the flow in the unburnt area's stream. What he didn't expect was that stormwater had permeated the ground in both of the burnt watersheds.

This finding contradicted scientists' previous beliefs that little water would be absorbed in the burnt watershed due to the presence of waxy soils.

In the unburnt watershed, however, the researchers found that trees absorbed the water as anticipated, preventing it from reaching streams.

West and PhD candidate Abra Atwood surmised that, in keeping with the popular notion, increased water in rivers originated from the burnt areas because burned trees and vegetation could not retain water in their roots as they normally would, but not from the inability of the soil to absorb water.

The research team's finding that the water-repellant layer does not prevent water from being absorbed into the soil strengthened their hypothesis that the water in streams comes from both rainfall and groundwater, leading to increased flooding in burnt areas versus unburnt.

Water build-up poses enduring threat

Identifying areas that are at high-risk for debris flow and mudslides and accurately predicting the amount of debris flow following rainfall in burn areas depends on understanding how water infiltrates the soil in different areas and how it contributes to the flow of streams.

Also, the dynamics of water flow and how water accumulates below the surface can significantly impact how quickly landscapes recover after a wildfire. This recovery affects the stability of hill slopes and helps buffer forests against severe drought.

On the flip side, water accumulation can contribute to landslides for up to four years after a fire as pressure builds up in the soil.

"The underground water accumulation suggests that the potential for landslides extends far beyond the two years following the fire, posing an enduring problem," West said. "The abundance of water stored in areas affected by the Bobcat Fire, for example, could serve as a harbinger of future flooding concerns in the years to come."

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New study shows anti-inflammatory drugs as a promising target for Alzheimer's disease

A recent study from the lab of the University of Kentucky's Sanders-Brown Center on Aging Director Linda Van Eldik, Ph.D., has been published in PLOS ONE. The work centers around the idea that various anti-inflammatory drugs could be effective treatments for Alzheimer's disease (AD). This study focused on a protein known as p38. Many labs have been working with this protein as a potential target for drug development to treat Alzheimer's disease and other conditions with neuroinflammatory dysfunction.

Van Eldik and her team used genetic techniques to stop the production of p38 in the major immune cell type within the brain, the microglia. They tested the effects of this in an early-stage mouse model of AD to determine whether it would alter the trajectory of amyloid plaque formation, a major component of AD pathology. While the plaques themselves were not affected, the amount of microglia in proximity to these plaques was decreased, suggesting that suppression of microglial p38 may affect their interactions with aspects of AD pathology.

Some classes of anti-inflammatory drugs include p38 inhibitors, which are currently under clinical development and have shown encouraging results during recent human clinical trials. However, it is still not clear when during the disease process these p38 inhibitors should be administered and whether long-term suppression of p38 is harmful. The findings reported by the Van Eldik lab indicate that early inhibition of p38 may be able to alter interactions between brain immune cells and AD pathology, and they suggest that long-term suppression of p38 does not cause noticeable adverse effects.

From Science Daily

Stellar cradles and graves seen in farthest galaxy ever

New observations using the Atacama Large Millimeter/submillimeter Array (ALMA) have distinguished the sites of star formation and a possible site of star death from the surrounding nebula in a galaxy 13.2 billion light-years away. This is the farthest that such structures have been observed.

A team led by Yoichi Tamura, an astronomer at Nagoya University, attempted high-resolution observations of MACS0416_Y1, located 13.2 billion light-years away in the constellation Eridanus. Previous observations of this galaxy by the same team had detected radio waves emitted by both oxygen and dust, two components of interstellar nebulae. Detailed observations of the distribution of dust and oxygen can provide clues about how stars are born and die within nebulae, but the observations had lacked the resolution needed to see the structure of the nebulae.

This time the team observed with ALMA for 28 hours, zooming in on MACS0416_Y1. The results showed that the dust signal regions and oxygen emission regions are intricately intertwined, avoiding each other, suggesting the process where newly formed stars within the nebulae ionize the surrounding gas.

Furthermore, the team found a massive cavity spanning approximately 1,000 light-years in the dust dominated regions. When many new, massive and short-lived stars are born together, the resulting successive supernova explosions create enormous "superbubbles" in the nebulae. The discovered cavity may indeed be such a superbubble.

Takuya Hashimoto from the University of Tsukuba describes the observation performance as follows: "It corresponds to capturing the extremely weak light emitted by two fireflies located 3 centimeters apart on the summit of Mount Fuji as seen from Tokyo, and being able to distinguish between those two fireflies."

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Form and function of island and mainland plants

Oceanic islands provide useful models for ecology, biogeography and evolutionary research. Many ground-breaking findings -- including Darwin's theory of evolution -- have emerged from the study of species on islands and their interplay with their living and non-living environment. Now, an international research team led by the University of Göttingen has investigated the flora of the Canary Island of Tenerife. The results were surprising: the island's plant-life exhibits a remarkable diversity of forms. But the plants differ little from mainland plants in functional terms. However, unlike the flora of the mainland, the flora of Tenerife is dominated by slow-growing, woody shrubs with a "low-risk" life strategy. The results were published in Nature.

The researchers investigated how the plants of Tenerife differ in functional terms from plants from other parts of the world. They conducted extensive field research and measurements at over 500 sites using the most up-to-date methods of functional ecology. The sites were scattered all over the island at altitudes ranging from sea level to mountainous regions above 3,300 metres. The scientists recorded about 80% of Tenerife's native seed plants, and surveyed eight plant characteristics: plant size, specific wood density, leaf thickness, absolute and specific leaf area, leaf dry matter, nitrogen concentration in leaf tissue, and seed weight. They compared their data with data on more than 2,000 plant species found on the mainland.

"Our study shows, for the first time and contrary to all expectations, that species groups that evolved on the Canary Islands do not contribute to the expansion of the breadth of different traits. This means they do not lead to more functional diversity," explains the lead of the study, Professor Holger Kreft, and Göttingen University's Biodiversity, Macroecology and Biogeography research group. Previous comparisons show that species occurring on islands can differ significantly from their relatives on the mainland. A well-known example is provided by the Galapagos giant tortoise: the species is only found on the Galapagos Islands and, as a result of adaptation to its environmental conditions, is much larger than tortoises from the mainland. The research team expected similar differences between island and mainland plants, but this was not the case. "Rather, we see that most species follow the constraints of the island climate. Thus, medium-sized, woody species develop. These tend to live with the limited resources and high risks of extinction on the island. That is, they grow slowly. The high functional diversity is mainly due to the species that are widespread on the island and the nearby mainland," explains Kreft.

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Despite doubts from quantum physicists: Einstein's theory of relativity reaffirmed

One of the most basic assumptions of fundamental physics is that the different properties of mass -- weight, inertia and gravitation -- always remain the same in relation to each other. Without this equivalence, Einstein's theory of relativity would be contradicted and our current physics textbooks would have to be rewritten. Although all measurements to date confirm the equivalence principle, quantum theory postulates that there should be a violation. This inconsistency between Einstein's gravitational theory and modern quantum theory is the reason why ever more precise tests of the equivalence principle are particularly important.

A team from the Center of Applied Space Technology and Microgravity (ZARM) at University of Bremen, in collaboration with the Institute of Geodesy (IfE) at Leibniz University Hannover, has now succeeded in proving with 100 times greater accuracy that passive gravitational mass and active gravitational mass are always equivalent -- regardless of the particular composition of the respective masses.

The research was conducted within the framework of the Cluster of Excellence "QuantumFrontiers." Today, the team published their findings as a highlights article in the scientific journal Physical Review Letters.

Physical context

Inertial mass resists acceleration. For example, it causes you to be pushed backwards into your seat when the car starts. Passive gravitational mass reacts on gravity and results in our weight on Earth. Active gravitational mass refers to the force of gravitation exerted by an object, or more precisely, the size of its gravitational field. The equivalence of these properties is fundamental to general relativity. Therefore, both the equivalence of inertial and passive gravitational mass and the equivalence of passive and active gravitational mass are being tested with increasing precision.

What was the study about?

If we assume that passive and active gravitational mass are not equal -- that their ratio depends on the material -- then objects made of different materials with a different centre of mass would accelerate themselves. Since the Moon consists of an aluminium shell and an iron core, with centres of mass offset against each other, the Moon should accelerate. This hypothetical change in speed could be measured with high precision, via "Lunar Laser Ranging." This involves pointing lasers from Earth at reflectors on the Moon placed there by the Apollo missions and the Soviet Luna programme. Since then, round trip travel times of laser beams are recorded. The research team analysed "Lunar Laser Ranging" data collected over a period of 50 years, from 1970 to 2022, and investigated such mass difference effects. Since no effect was found, this means that the passive and active gravitational masses are equal to approximately 14 decimal places. This estimate is a hundred times more accurate than the best previous study, dating back to 1986.

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Our favorite vintages and their precarious mountainside homes are at risk due to climate change, environmental scientists warn

Tucked into the hillsides of Italy, Portugal, and Spain, some of the world's most famous -- and most difficult to maintain -- vineyards are heralded for their unique flavor profiles and centuries of tradition. But as extreme weather and changing socioeconomic conditions make this so-called "heroic viticulture" even more challenging, scientists worry these grapes and their cultural histories are at risk. In a Backstory publishing on July 14 in the journal iScience, researchers argue that farmers and scientists must work together to protect some of the world's most celebrated wines.

"The risk is not only losing an agricultural product or seeing a landscape change, negatively impacting the local economy," write the authors from the University of Padova. "The risk is losing entire communities' history and their cultural roots."

Vineyards are considered "heroic viticulture" sites if they have a slope steeper than 30 percent, are located on small islands or at an altitude higher than 500 meters above sea level, or if they incorporate vines grown on terraces. The name "heroic" originated from the inherent difficulty of cultivating and harvesting crops in these landscapes. Some of the most famous, centuries-old examples of heroic viticulture include the Prosecco Hills of Conegliano and Valdobbiadene and the traditional vineyards of Pantelleria Island, both of which are protected by UNESCO.

"The great effort required to manage these areas reinforces the specific human-environment connection," write the authors. "This is why they are recognized as cultural uniquenesses of primary historical and social importance, where traditional knowledge is still the determining element."

In the Backstory, the authors list soil degradation and drought as the biggest climate change-related risks to heroic viticulture. They also argue that the vineyards face several significant socioeconomic barriers.

"The last half past century has been characterized by rural exodus and a gradual abandonment of mountain landscapes," the authors write. "The new generation is unwilling to continue working under extreme conditions if economic benefits are insignificant."

In order to protect heroic viticulture sites, the authors suggest several forms of potential solutions, from strategic communications designed to unite scientists, farmers, and consumers to onsite solutions like small water storage systems integrated into the vineyard landscapes that prevent runoff and retain water for future usage. They also underline the importance of education, including "educating the new generation about the benefits of rural reality, the need to preserve cultural heritage, live in equilibrium with the environment, and to have a sustainable approach to agriculture."

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