Apr 22, 2023

Could this copycat black hole be a new type of star?

It looks like a black hole and bends light like a black hole, but it could actually be a new type of star.

Though the mysterious object is a hypothetical mathematical construction, new simulations by Johns Hopkins researchers suggest there could be other celestial bodies in space hiding from even the best telescopes on Earth. The findings are set to publish in Physical Review D.

"We were very surprised," said Pierre Heidmann, a Johns Hopkins University physicist who led the study. "The object looks identical to a black hole, but there's light coming out from its dark spot."

The detection of gravitational waves in 2015 rocked the world of astrophysics because it confirmed the existence of black holes. Inspired by those findings, the Johns Hopkins team set out to explore the possibility of other objects that could produce similar gravitational effects but that could be passing as black holes when observed with ultraprecise sensors on Earth, said co-author and Johns Hopkins physicist Ibrahima Bah.

"How would you tell when you don't have a black hole? We don't have a good way to test that," Bah said. "Studying hypothetical objects like topological solitons will help us figure that out as well."

The new simulations realistically depict an object the Johns Hopkins team calls a topological soliton. The simulations show an object looking like a blurry photo of a black hole from afar but like something else entirely up close.

The object is hypothetical at this stage. But the fact that the team could construct it using mathematical equations and show what it looks like with simulations suggests there could be other types of celestial bodies in space hiding from even the best telescopes on Earth.

The findings show how the topological soliton distorts space exactly as a black hole does -- but behaves unlike a black hole as it scrambles and releases weak light rays that would not escape the strong gravitational force of a true hole.

"Light is strongly bent, but instead of being absorbed like it would in a black hole, it scatters in funky motions until at one point it comes back to you in a chaotic manner," Heidmann said. "You don't see a dark spot. You see a lot of blur, which means light is orbiting like crazy around this weird object."

A black hole's gravitational field is so intense that light can orbit around it at a certain distance from its center, in the same way that Earth orbits the sun. This distance determines the edge of the hole's "shadow," so that any incoming light will fatally hit the region that scientists call the "event horizon." There, nothing can escape -- not even light.

The Hopkins team simulated several scenarios using pictures of outer space as if they had been captured with a camera, placing a black hole and the topological soliton in front of the lens. The results produced distorted pictures because of the gravitational effects of the massive bodies.

"These are the first simulations of astrophysically relevant string theory objects, since we can actually characterize the differences between a topological soliton and a black hole as if an observer was seeing them in the sky," Heidmann said.

Motivated by various results from string theory, Bah and Heidmann discovered ways to construct topological solitons using Einstein's theory of general relativity in 2021. While the solitons are not predictions of new objects, they serve as the best models of what new quantum gravity objects could look like compared to black holes.

Scientists have previously created models of boson stars, gravastars, and other hypothetical objects that could exert similar gravitational effects with exotic forms of matter. But the new research accounts for pillar theories of the inner workings of the universe that other models don't. It uses string theory that reconciles quantum mechanics and Einstein's theory of gravity, the researchers said.

"It's the start of a wonderful research program," Bah said. "We hope in the future to be able to genuinely propose new types of ultracompact stars consisting of new kinds of matter from quantum gravity."

Read more at Science Daily

Ridgecrest faults increasingly sensitive to solid Earth tides before earthquakes

Faults in the Ridgecrest, California area were very sensitive to solid earth tidal stresses in the year and a half before the July 2019 Ridgecrest earthquake sequence, researchers reported at the Seismological Society of America (SSA)'s 2023 Annual Meeting.

"The signal of tidal modulation becomes extremely strong" after 2018, said Eric Beauce of Lamont-Doherty Earth Observatory, who noted that the signal was identified with seismicity that occurred around the faults that broke in the 2019 magnitude 7.1 earthquake.

The link does not mean that tidal stresses -- which are very small compared to other tectonic stresses -- triggered the earthquake, however.

"We don't know if something started to happen in the fault zone, something that is an indicator of the upcoming earthquake," Beauce said. "Maybe that process changed the properties of the crust in a way that made the crust be more sensitive to tidal stresses."

Pulled by the same gravitational forces of sun and moon that create ocean tides, the solid earth also deforms in the same periodic way. People can't feel the changes, but the ground deforms between 10 to 20 centimeters a day.

These solid tides "induce very, very small stress changes in the crust," Beauce explains, "which can induce stress changes in all the faults within the crust."

Although researchers have known about these tiny stress changes for more than a century, it has been difficult to extract their signal from the seismic record, and to determine whether they modulate seismicity.

In the past ten years, however, better earthquake detection and analysis techniques have made it possible to search through earthquake catalogs to find the signal of tidal stresses, Beauce said.

He and his colleagues built a rich, high-resolution earthquake catalog, using machine learning algorithms along with other techniques, for the past decade of microseismicity in the Ridgecrest area. (Microseismicity usually refers to earthquakes of magnitude 2.0 or smaller).

They found that "there is suggestive evidence that peak seismicity happens when tidal stresses are maximum," Beauce said, "but this modulation is weak, and because it is weak, it is only suggested."

Other researchers looking at the 2004 Indian Ocean and 2011 Tohoku megathrust earthquakes have detected an increase in modulation of seismicity connected to tidal stresses, decades before the earthquakes, said Beauce. And some scientists have been able to generate similar results in lab-created earthquake experiments.

Read more at Science Daily

Apr 21, 2023

Chicken breeding in Japan dates back to fourth century BCE

Conclusive evidence of chicken breeding in the Yayoi period of Japan has been discovered from the Karako-Kagi site.

The chicken is one of the most common domesticated animals, with a current estimated population of over 33 billion individuals. They are reared for their meat and eggs, and may be kept as pets.

The chicken is believed to have been domesticated in Southeast Asia about 3500 years ago, following which they were carried to all corners of the world. The exact date of introduction of chicken breeding to Japan is under debate, as there are no historical records and archeological evidence is inconclusive.

Professor Masaki Eda at the Hokkaido University Museum led a team to uncover the earliest conclusive evidence of chicken breeding in Japan. The findings, which show chickens were bred in the Karako-Kagi site, a settlement from the Yayoi period [5th century BCE to around 2nd century BCE], were published in the journal Frontiers in Earth Sciences.

"Chickens and their wild relatives belong to a family of birds called Phasianids, which includes pheasants, turkeys and quail," explains Eda. "Bones of juvenile phasianids recovered from archeological sites could not indisputably be identified as belonging to chickens or to similarly sized wild pheasants. Identification of juveniles is important, as it would indicate that breeding of chickens took place."

The Karako-Kagi site, in what is now Tawaramoto Town, Nara Prefecture, is considered to be a settlement that played the role of a leader of the Kinki region during the Yayoi period. There are multiple archeological digs in the area; one such dig, at the 58th research point, yielded ten phasianid bones, four of which belonged to juvenile birds.

The team used a technique called Zooarchaeology by Mass Spectrometry (ZooMS) to analyze the collagen in two of the juvenile phasianid bones. Previous work by Eda had shown that domestic chicken and Japanese wild pheasants had different ZooMS fingerprints; ZooMS revealed that both the two bones belonged to chickens. The collagen from one of the bones was also carbon dated to 381-204 BCE, corresponding to the middle Yayoi period.

"Ten of the eleven previously-discovered bones of adult chickens from this period have all belonged to males; hence, it was thought chicken breeding could not have occurred on the Japanese archipelago," Eda elaborated. "By identifying bones from juvenile chickens, we provide clear evidence that breeding did occur in that time period -- which is also the earliest time chickens could have been introduced to Japan. In addition, Karako-Kagi is considered an important trade hub of the Yayoi period, so there is a possibility that this status is a factor in chicken breeding during the period."

Read more at Science Daily

Grambank shows the diversity of the world's languages

Linguists have long been interested in language variation. What are common or universal patterns across languages? What limits the possible variation between them? Grambank, the world's largest and most comprehensive database of language structure, enables researchers to answer some of these questions.

Grambank was constructed in an international collaboration between the Max Planck institutes in Leipzig and Nijmegen, the Australian National University, the University of Auckland, Harvard University, Yale University, the University of Turku, Kiel University, Uppsala University, SOAS, the Endangered Languages Documentation Programme, and over a hundred scholars from around the world. Grambank's coverage spans 215 different language families and 101 isolates from all inhabited continents. "The design of the feature questionnaire initially required numerous revisions in order to encompass many of the diverse solutions that languages have evolved to code grammatical properties," says Hedvig Skirgård, who coordinated much of the coding and is the lead author of the study.

Limits on variation

The team settled on 195 grammatical properties, ranging from word order to whether or not a language has gendered pronouns. For instance, many languages have separate pronouns for 'he' and 'she', but some also have male and female versions of 'I' or 'you'. The possible 'design space' would be enormous if grammatical properties were to vary freely. Limits on variation could be related to cognitive principles rooted in memory or learning, rendering some grammatical structures more likely than others. Limits could also be related to historical 'accidents', such as descent from a common language or contact with other languages.

The researchers discovered much greater flexibility in the combination of grammatical features than many theorists have assumed. "Languages are free to vary considerably in quantifiable ways, but not without limits," explains Stephen Levinson, Director emeritus of the Max Planck Institute for Psycholinguistics in Nijmegen and one of the founders of the Grambank project. "A sign of the extraordinary diversity of the 2400 languages in our sample is that only five of them occupy the same location in design space (share the same grammatical properties)."

Languages show much greater similarity to those with a common ancestor than those they are in contact with. "Genealogy generally trumps geography," says Russell Gray, Director of the Department of Linguistic and Cultural Evolution and senior author of the study. "Nevertheless, if processes of linguistic evolution and diversification were run again from the beginning, there would still be some resemblance to what we now have. The constraints of human cognition mean that, while there is a great deal of historical contingency in the organisation of grammatical structures, there are regular patterns as well."

Diversity under threat

"The extraordinary diversity of languages is one of humanity's greatest cultural endowments," concludes Levinson. "This endowment is under threat, especially in some areas such as Northern Australia, and parts of South and Northern America. Without sustained efforts to document and revitalise endangered languages, our linguistic window into human history, cognition and culture will be seriously fragmented."

Read more at Science Daily

Greenhouse gas release from permafrost is influenced by mineral binding processes

About a quarter of the organic carbon contained in ice-rich Arctic permafrost is more difficult for microorganisms to utilize. The reason for this is a strong binding of the organic material originating from dead plant remains to mineral soil particles. That is the result of a study conducted by a research group led by Professor Dr Janet Rethemeyer and Dr Jannik Martens at the University of Cologne's Institute of Geology and Mineralogy. Accurate predictions of the release of greenhouse gases from permafrost deposits are therefore more complex than previously assumed.

The results of the joint project, which was funded by the German Federal Ministry of Education and Research (BMBF), are published in the article 'Stabilization of mineral-associated organic carbon in Pleistocene permafrost' in the journal Nature Communications.

The Arctic is warming dramatically fast compared to other parts of the world. Much of it is covered by permafrost and contains large amounts of carbon, almost twice as much as the atmosphere. This carbon comes from plants that have grown over thousands of years, decomposed in the soil and then become 'frozen'. Due to strongly rising temperatures in the Arctic, this gigantic freezer is thawing fast. The old carbon stored in it can now be degraded by microorganisms, releasing carbon dioxide and methane into the atmosphere. These greenhouse gases accelerate global warming. The warmer it gets, the more greenhouse gases are in turn released from the permafrost, causing temperatures to rise further and frozen soils and sediments to thaw even faster. "There is a feedback of carbon in permafrost with climate, the strength of which depends largely on those factors that influence microbial degradation," said Janet Rethemeyer.

In the joint research project, scientists from the Institute of Zoology at the University of Cologne, the University of Tübingen, the Technical University of Munich and the Alfred-Wegener-Institute in Potsdam studied long permafrost cores from the Siberian Arctic. The cores come from very ice-rich, fine-grained sediments -- similar to loess in our latitudes -- that were deposited in large areas of Siberia and Alaska during the last ice age. The cores, up to 12 metres long, comprise sediments deposited over a period of up to 55,000 years.

The analyses of the permafrost cores show that a significant part (25-35 %) of the carbon is associated with the mineral particles and thus more difficult to access for microorganisms. "Predictions of interactions between thawing permafrost and climate are very complicated because the microbial degradability of the organic material in the sediments has varied greatly over the last 55,000 years. This is due to the different climatic conditions during this long period of deposition," Janet Rethemeyer explained. Warmer and wetter conditions resulted in poorer binding of carbon to the mineral particles, while a colder and drier climate led to stronger binding, primarily to iron oxides. Stronger binding to iron oxides means that the decomposition rates of old plant material are lower, as Professor Dr. Michael Bonkowski from the Institute of Zoology, Department of Terrestrial Ecology at the University of Cologne has shown in laboratory experiments.

Read more at Science Daily

Elephant seals drift off to sleep while diving far below the ocean surface

For the first time, scientists have recorded brain activity in a free-ranging, wild marine mammal, revealing the sleep habits of elephant seals during the months they spend at sea.

The new findings, published April 20 in Science, show that while elephant seals may spend 10 hours a day sleeping on the beach during the breeding season, they average just 2 hours of sleep per day when they are at sea on months-long foraging trips. They sleep for about 10 minutes at a time during deep, 30-minute dives, often spiraling downward while fast asleep, and sometimes lying motionless on the seafloor.

First author Jessica Kendall-Bar led the study as a UC Santa Cruz graduate student working with Daniel Costa and Terrie Williams, both professors of ecology and evolutionary biology at UCSC.

"For years, one of the central questions about elephant seals has been when do they sleep," said Costa, who directs UCSC's Institute of Marine Sciences. Costa's lab has led the UCSC elephant seal research program at Año Nuevo Reserve for over 25 years, using increasingly sophisticated tags to track the movements and diving behavior of the seals during their foraging migrations, when they head out into the North Pacific Ocean for as long as 8 months.

"The dive records show that they are constantly diving, so we thought they must be sleeping during what we call drift dives, when they stop swimming and slowly sink, but we really didn't know," Costa said. "Now we're finally able to say they're definitely sleeping during those dives, and we also found that they're not sleeping very much overall compared to other mammals."

In fact, during their months at sea, elephant seals rival the record for the least sleep among all mammals, currently held by African elephants, which appear to sleep just two hours per day based on their movement patterns.

"Elephant seals are unusual in that they switch between getting a lot of sleep when they're on land, over 10 hours a day, and two hours or less when they're at sea," said Kendall-Bar, who is currently a postdoctoral fellow at UC San Diego's Scripps Institution of Oceanography.

Elephant seals are most vulnerable to predators such as sharks and killer whales when they are at the surface in the open ocean, so they only spend a minute or two breathing at the surface in between dives.

"They're able to hold their breath for a long time, so they can go into a deep slumber on these dives deep below the surface where it's safe," Kendall-Bar said.

Kendall-Bar developed a system that can reliably record brain activity (as an electroencephalogram or EEG) in wild elephant seals during their normal diving behavior at sea. With a neoprene headcap to secure the EEG sensors and a small data logger to record the signals, the system can be recovered when the animals return to the beach at Año Nuevo.

"We used the same sensors you'd use for a human sleep study at a sleep clinic and a removable, flexible adhesive to attach the headcap so that water couldn't get in and disrupt the signals," Kendall-Bar said.

In addition to the EEG system, the seals carried time-depth recorders, accelerometers, and other instruments that allowed the researchers to track the seals' movements along with the corresponding brain activity. The recordings show diving seals going into the deep sleep stage known as slow-wave sleep while maintaining a controlled glide downward, then transitioning into rapid-eye-movement (REM) sleep, when sleep paralysis causes them to turn upside down and drift downwards in a "sleep spiral."

"They go into slow-wave sleep and maintain their body posture for several minutes before they transition into REM sleep, when they lose postural control and turn upside down," Kendall-Bar said.

At the depths at which this happens, the seals are usually negatively buoyant and continue to fall passively in a corkscrew spiral "like a falling leaf," Williams said. In shallower waters over the continental shelf, elephant seals sometimes sleep while resting on the seafloor.

"It doesn't seem possible that they would truly go into paralytic REM sleep during a dive, but it tells us something about the decision-making processes of these seals to see where in the water column they feel safe enough to go to sleep," said Williams, who directs the Comparative Neurophysiology Lab at UCSC.

In developing the new EEG instrument, Kendall-Bar first deployed it on elephant seals housed temporarily in the marine mammal facilities at UCSC's Long Marine Laboratory. The next step was to deploy it on animals in the elephant seal colony at Año Nuevo Reserve north of Santa Cruz, where researchers could observe the animals on the beach.

"I spent a lot of time watching sleeping seals," Kendall-Bar said. "Our team monitored instrumented seals to make sure they were able to reintegrate with the colony and were behaving naturally."

Some of those seals took short excursions into the water, but to observe diving behavior the researchers used a translocation procedure developed by Costa's lab. Juvenile female elephant seals outfitted with the EEG sensors and trackers were transported from Año Nuevo to Monterey and released on a beach at the southern end of Monterey Bay. Over the next few days, the animals would swim back to Año Nuevo across the deep Monterey Canyon, where their dive behavior is very similar to that seen during much longer foraging trips in the open ocean.

With data on brain activity and dive behavior from 13 juvenile female elephant seals, including a total of 104 sleep dives, Kendall-Bar developed a highly accurate algorithm for identifying periods of sleep based on the dive data alone. This enabled her to estimate sleep quotas for 334 adult seals using dive data recorded over several months during their foraging trips.

"Because of the dataset that Dan Costa has curated over 25 years of working with elephant seals at Año Nuevo, I was able to extrapolate our results to over 300 animals and get a population-level look at sleep behavior," said Kendall-Bar, who now plans to use similar methods to study brain activity in other species of seals and sea lions and in human freedivers.

Williams called Kendall-Bar's work on the project a tour de force. "It's an amazing feat to pull this off," she said. "She developed an EEG system to work on an animal that's diving several hundred meters in the ocean. Then she uses the data to create data-driven animations so we can really visualize what the animal is doing as it dives through the water column."

The results may be helpful for conservation efforts by revealing a "sleepscape" of preferred resting areas, Williams said. "Normally, we're concerned about protecting the areas where animals go to feed, but perhaps the places where they sleep are as important as any other critical habitat," she said.

Read more at Science Daily

Apr 20, 2023

Metal-poor stars are more life-friendly

Stars that contain comparatively large amounts of heavy elements provide less favourable conditions for the emergence of complex life than metal-poor stars, as scientists from the Max Planck Institutes for Solar System Research and for Chemistry as well as from the University of Göttingen have now found. The team showed how the metallicity of a star is connected to the ability of its planets to surround themselves with a protective ozone layer. Crucial to this is the intensity of the ultraviolet light that the star emits into space, in different wavelength ranges. The study provides scientists searching the sky with space telescopes for habitable star systems with important clues as to where this endeavour could be particularly promising. It also suggests a startling conclusion: as the universe ages, it becomes increasingly unfriendly to the emergence of complex life on new planets.

In the search for habitable or even inhabited planets orbiting distant stars, researchers have in the past years increasingly focused on the gas envelopes of these worlds. Do observational data show evidence of an atmosphere? Does it perhaps even contain gases such as oxygen or methane, which on Earth are produced almost exclusively as metabolic products of lifeforms? In the next years, such observations will be pushed to new limits: Nasa's James Webb Telescope will make it possible to not only characterize the atmospheres of large gas giants like Super-Neptunes, but also to analyze for the first time the much fainter spectrographic signals from rocky planet atmospheres.

With the help of numerical simulations, the current study, which was published in Nature Communications today, now turns to the ozone content of exoplanet atmospheres. As on Earth, this compound of three oxygen atoms can protect the planet's surface (and life forms residing on it) from cell-damaging ultraviolet (UV) radiation. A protective layer of ozone is thus an important prerequisite for the emergence of complex life. "We wanted to understand what properties a star must have in order for its planets to form a protective ozone layer," Anna Shapiro, scientist at the Max Planck Institute for Solar System Research and first author of the current study, explains the basic idea.

As often in science, this idea was triggered by an earlier finding. Three years ago, researchers led by the Max Planck Institute for Solar System Research had compared the Sun's brightness variations with those of hundreds of Sun-like stars. The result: the intensity of the visible light from many of these stars fluctuates much more strongly than in the case of the Sun. "We saw huge peaks in intensity," says Alexander Shapiro, who was involved in both the analyses from three years ago and the current study. "It is therefore quite possible, that the Sun, too, is capable of such spikes in intensity. In that case, also the intensity of the ultraviolet light would increase dramatically," he adds. "So naturally we wondered, what this would mean for life on Earth and what the situation is like in other star systems," says Sami Solanki, director at the Max Planck Institute for Solar System Research and co-author of both studies.

Dual role of UV radiation

At the surface of about half of all stars around which exoplanets have been shown to orbit, temperatures range from about 5,000 to about 6,000 degrees Celsius. In their calculations, the researchers therefore turned to this subgroup. With a surface temperature of approximately 5500 degrees Celsius, the Sun is also one of them. "In the Earth's atmospheric chemistry, ultraviolet radiation from the Sun plays a dual role," explains Anna Shapiro, whose past research interest focused on the influence of solar radiation on Earth's atmosphere. In reactions with individual oxygen atoms and oxygen molecules, ozone can both be created and destroyed. While long-wave UV-B radiation destroys ozone, short-wave UV-C radiation helps create protective ozone in the middle atmosphere. "It was therefore reasonable to assume that ultraviolet light may have a similarly complex influence on exoplanet atmospheres as well," the astronomer adds. The precise wavelengths are crucial.

The researchers therefore calculated exactly which wavelengths make up the ultraviolet light emitted by the stars. For the first time, they also considered the influence of metallicity. This property describes the ratio of hydrogen to heavier elements (simplistically and somewhat misleadingly called "metals" by astrophysicists) in the building material of the star. In the case of the Sun, there are more than 31000 hydrogen atoms for every iron atom. The study also considered stars with lower and higher iron content.

Simulated interactions of UV radiation with gases

In a second step, the team investigated how the calculated UV radiation would affect the atmospheres of planets orbiting at a life-friendly distance around these stars. Life-friendly distances are those that allow moderate temperatures -- neither too hot nor too cold for liquid water -- at the planet's surface. For such worlds, the team simulated on the computer exactly which processes the parent star's characteristic UV light sets in motion in the planet's atmosphere.

To compute the composition of planetary atmospheres the researchers used a chemistry-climate model that simulates the processes that control oxygen, ozone, and many other gases, and their interactions with ultraviolet light from stars, at very high spectral resolution. This model allowed the investigation of a wide variety of conditions on exoplanets and comparison with the history of the Earth's atmosphere in the last half billion years. During this period the high atmospheric oxygen content and the ozone layer were established that allowed the evolution of life on land on our planet. "It is feasible that the history of the Earth and its atmosphere holds clues about the evolution of life that may also apply to exoplanets" says Jos Lelieveld, Managing Director of the Max Planck Institute for Chemistry, who was involved in the study.

Promising candidates


The results of the simulations were surprising for the scientists. Overall, metal-poor stars emit more UV radiation than their metal-rich counterparts. But the ratio of ozone-generating UV-C radiation to ozone-destroying UV-B radiation also depends critically on metallicity: in metal-poor stars, UV-C radiation predominates, allowing a dense ozone layer to form. For metal-rich stars, with their predominant UV-B radiation, this protective envelope is much more sparse. "Contrary to expectations, metal-poor stars should thus provide more favourable conditions for the emergence of life," Anna Shapiro concludes. This finding could be helpful for future space missions such as Esa's Plato mission, which will comb through a vast array of stars for signs of habitable exoplanets. With 26 telescopes on board, the eponymous probe will be launched into space in 2026 and will focus its attention primarily on Earth-like planets orbiting Sun-like stars at life-friendly distances. The mission's data centre is currently being set up at the Max Planck Institute for Solar System Research. "Our current study gives us valuable clues as to which stars Plato should pay special attention to," says Laurent Gizon, Managing Director at the Institute and co-author of the current study.

Read more at Science Daily

Long-distance quantum teleportation enabled by multiplexed quantum memories

Quantum teleportation is a technique allowing the transfer of quantum information between two distant quantum objects, a sender and a receiver, using a phenomenon called quantum entanglement as a resource. The unique feature of this process is that the actual information is not transferred by sending quantum bits (qubits) through a communication channel connecting the two parties; instead, the information is destroyed at one location and appears at the other one without physically travelling between the two. This surprising property is enabled by quantum entanglement, accompanied by the transmission of classical bits.

There is a deep interest in quantum teleportation nowadays within the field of quantum communications and quantum networks because it would allow the transfer of quantum bits between network nodes over very long distances, using previously shared entanglement. This would help the integration of quantum technologies into current telecommunication networks and extend the ultra-secure communications enabled by these systems to very long distances. In addition, quantum teleportation permits the transfer of quantum information between different kinds of quantum systems, e.g. between light and matter or between different kinds of quantum nodes.

Quantum teleportation was theoretically proposed in the early 90s and experimental demonstrations were carried out by several groups around the world. While the scientific community has gained extensive experience on how to perform these experiments, there is still an open question on how to teleport information in a practical way, allowing reliable and fast quantum communication over an extended network. It seems clear that such an infrastructure should be compatible with the current telecommunications network. In addition, the protocol of quantum teleportation requires a final operation to be applied on the teleported qubit, conditioned on the result of the teleportation measurement (transmitted by classical bits), in order to transfer the information faithfully and at a higher rate, a feature called active feed-forward. This means that the receiver requires a device known as a quantum memory that can store the qubit without degrading it until the final operation can be implemented. Finally, this quantum memory should be able to operate in a multiplexed fashion to maximize the speed of teleporting information when the sender and the receiver are far away. To date, no implementation had incorporated these three requirements in the same demonstration.

In a recent study published in Nature Communications, ICFO researchers Dario Lago-Rivera, Jelena V. Rakonjac, Samuele Grandi, led by ICREA Prof. at ICFO Hugues de Riedmatten have reported achieving long distance teleportation of quantum information from a photon to a solid-state qubit, a photon stored in a multiplexed quantum memory. The technique involved the use of an active feed-forward scheme, which, together with the multimodality of the memory, has allowed maximization of the teleportation rate. The proposed architecture was compatible with the telecommunications channels, and thus enabling future integration and scalability for long-distance quantum communication.

How to achieve quantum teleportation

The team built two experimental setups, that in the jargon of the community are usually called Alice and Bob. The two setups were connected by a 1km optical fiber spun up in a spool, to emulate a physical distance between the parties.

Three photons were involved in the experiment. In the first setup, Alice, the team used a special crystal to create two entangled photons: the first photon at 606 nm, called signal photon, and the second photon called idler photon, compatible with the telecommunications infrastructure. Once created, "we kept the first 606 nm photon at Alice and stored it in a multiplexed solid-state quantum memory, holding it in the memory for future processing. At the same time, we took the telecom photon created at Alice and sent it through the 1km of optical fiber to reach the second experimental setup, called Bob," Dario Lago recalls.

In this second setup, Bob, the scientists had another crystal where they created a third photon, where they had encoded the quantum bit they wanted to teleport. Once the third photon was created, the second photon had arrived to Bob from Alice, and this is where the core of the teleportation experiment takes place.

Teleporting information over 1km

The second and third photons interfered with each other through what is known as a Bell State measurement (BSM). The effect of this measurement was to mix the state of the second and third photon. Thanks to the fact that the first and second photons were entangled to begin with, i.e. their joint state was highly correlated, the result of the BSM was that of transferring the information encoded in the third photon to the first one, stored by Alice in the quantum memory, 1 km away. As Dario Lago and Jelena Rakonjac mention, "we are capable of transferring information between two photons that were never in contact before, but connected through a third photon that was indeed entangled with the first. The uniqueness of this experiment lies in the fact that we employed a multiplexed quantum memory capable of storing the first photon for long enough such that by the time Alice found out that the interaction had happened, we were still able to process the teleported information as the protocol requires."

This processing that Dario and Jelena mention was the active feed-forward technique mentioned earlier. Depending on the outcome of the BSM, a phase-shift was applied to the first photon after storage in the memory. In this way, the same state would always be encoded in the first photon. Without this, half of the teleportation events would have to be discarded. Moreover, the multimodality of the quantum memory allowed them to increase the teleportation rate beyond the limits imposed by the 1 km separation between them without degrading the quality of the teleported qubit. Overall, this resulted in a teleportation rate three times higher than for a single-mode quantum memory, only limited by the speed of the classical hardware.

Scalability and Integration

The experiment carried out by this group in 2021, where they achieved for the first time entanglement of two multimode quantum memories separated by 10 meters and heralded by a photon at the telecommunication wavelength, has been the precursor of this experiment.

As Hugues de Riedmatten emphasizes, "Quantum teleportation will be crucial for enabling high-quality long-distance communication for the future quantum internet. Our goal is to implement quantum teleportation in more and more complex networks, with previously distributed entanglement. The solid-state and multiplexed nature of our quantum nodes as well as their compatibility with the telecom network make them a promising approach to deploy the technology over long distance in the installed fiber network."

Read more at Science Daily

Scientists identify 2022 sea urchin killer

The search for the 2022 killer that decimated the long-spined sea urchin population in the Caribbean and along Florida's east coast is over. A team of researchers organized by Mya Breitbart, Distinguished University Professor at the University of South Florida's College of Marine Science, identified a single-celled organism called a ciliate as the cause of a massive die-off event to a marine animal vital to coral reef health.

Their findings were reported in Science Advances.

"We're beyond thrilled to get to the bottom of the 2022 mystery and a bit stunned we did it so quickly," said Breitbart, senior author on the Science Advances study and an expert in marine genomics. "We had a great team in place and the tools needed to do the ocean science equivalent of a forensic investigation."

Ciliates are microscopic organisms covered in hair-like structures called cilia that help them move and eat. They are found almost anywhere there is water and most are not disease-causing agents. However, this specific species of ciliate -- called a scuticociliate -- has been implicated in die-offs of other marine species, such as sharks, in the past.

Examining urchins collected from 23 sites in the Caribbean, the research team used a series of techniques to confirm the source of the die-off event.

After identifying the ciliate in every affected urchin specimen using genomic techniques, the team grew ciliates in the lab and performed infection experiments at the USF College of Marine Science. When the pathogen was introduced to otherwise healthy urchins in an aquarium tank, the urchins died within a few days -- replicating what was taking place in the ocean and confirming the ciliate as the disease source.

"We're excited to share this information with everyone, from reef managers to additional scientists so we can explore it further and try to stop its spread," Breitbart said.

The long-spined sea urchins inhabit shallow tropical waters and feed on algae that would otherwise destroy a reef. They began to lose their spines within days of contracting an unknown disease and died in droves starting in January 2022.

A similar die-off event took place in the early 1980s, which wiped out 98 percent of the long-spined sea urchin population. The culprit of that die-off remains a mystery.

Breitbart first got the call about the unfolding die-off at the end of March 2022. She immediately assembled a team consisting of Ian Hewson, lead author on the publication and a marine ecologist at Cornell University; Christina Kellogg, a microbiologist from the U.S. Geological Survey in St. Petersburg, Fla. who has worked extensively on coral reef diseases; and USF graduate student Isabella Ritchie.

"At the time, we didn't know if this die-off was caused by pollution, stress, something else -- we just didn't know," said Hewson, an expert in diseases that cause mass die-offs of sea stars, who flew from New York to the Caribbean Islands to observe the situation.

Even with the source of the mysterious die-off uncovered, questions still remain. For example:
 

  • Is this ciliate new to the area, or was it there prior to the die-off?
  • If it has been there, what environmental conditions favored its growth and why did it infect the urchins?
  • Can it affect other species of urchins?


"One theory we have is that the ciliate grew well under high-productivity conditions that were observed in the Caribbean when the die-off first started," Kellogg said. "We're also curious about the fact that there is some overlap in some geographic areas where this die-off occurred and where corals are declining from stony coral tissue loss disease."

Read more at Science Daily

Fossils reveal the long-term relationship between feathered dinosaurs and feather-feeding beetles

New fossils in amber have revealed that beetles fed on the feathers of dinosaurs about 105 million years ago, showing a symbiotic relationship of one-sided or mutual benefit, according to an article published in Proceedings of the National Academy of Sciences today.

The main amber fragments studied, from the Spanish locality of San Just (Teruel), contain larval moults of small beetle larvae tightly surrounded by portions of downy feathers. The feathers belonged to an unknown theropod dinosaur, either avian (a term referring to "birds" in wide sense) or non-avian, as both types of theropods lived during the Early Cretaceous and shared often indistinguishable feather types. However, the studied feathers did not belong to modern birds since the group appeared about 30 million years later in the fossil record, during the Late Cretaceous.

When looking at modern ecosystems, we see how ticks infest cattle, frogs capture insects with acrobatic tongues, or some barnacles grow on the skin of whales. These are just a few of the diverse and complex ecological relationships between vertebrates and arthropods, which have coexisted for more than 500 million years. The way that these two groups have interacted throughout deep time is thought to have critically shaped their evolutionary history, leading to coevolution. Nevertheless, evidence of arthropod-vertebrate relationships is extremely rare in the fossil record.

The larval moults preserved in the amber were identified as related to modern skin beetles, or dermestids. Dermestid beetles are infamous pests of stored products or dried museum collections, feeding on organic materials that are hard for other organisms to decay such as natural fibres. However, dermestids also play a key role in the recycling of organic matter in the natural environment, commonly inhabiting nests of birds and mammals, where feathers, hair, or skin accumulate.

"In our samples, some of the feather portions and other remains -- including minute fossil faeces, or coprolites -- are in intimate contact with the moults attributed to dermestid beetles and show occasional damage and/or signs of decay. This is hard evidence that the fossil beetles almost certainly fed on the feathers and that these were detached from its host," explains Dr Enrique Peñalver, from the Geological and Mining Institute of Spain of the Spanish National Research Council (CN IGME-CSIC) and lead author of the study.

"The beetle larvae lived -- feeding, defecating, moulting -- in accumulated feathers on or close to a resin-producing tree, probably in a nest setting. A flow of resin serendipitously captured that association and preserved it for millions of years."

"Three additional amber pieces each containing an isolated beetle moult of a different maturity stage but assigned to the same species were also studied, allowing a better understanding of these minute insects than what is usually possible in palaeontology," says Dr David Peris, from the Botanical Institute of Barcelona (CSIC-Barcelona City Council) and co-author of the study. The most impressive, complete specimen was found in the amber deposit of Rábago/El Soplao in the northern Spain, roughly of the same age as San Just.

Read more at Science Daily

Apr 19, 2023

How did Earth get its water?

Our planet's water could have originated from interactions between the hydrogen-rich atmospheres and magma oceans of the planetary embryos that comprised Earth's formative years, according to new work from Carnegie Science's Anat Shahar and UCLA's Edward Young and Hilke Schlichting. Their findings, which could explain the origins of Earth's signature features, are published in Nature.

For decades, what researchers knew about planet formation was based primarily on our own Solar System. Although there are some active debates about the formation of gas giants like Jupiter and Saturn, it is widely agreed upon that Earth and the other rocky planets accreted from the disk of dust and gas that surrounded our Sun in its youth.

As increasingly larger objects crashed into each other, the baby planetesimals that eventually formed Earth grew both larger and hotter, melting into a vast magma ocean due to the heat of collisions and radioactive elements. Over time, as the planet cooled, the densest material sank inward, separating Earth into three distinct layers -- the metallic core, and the rocky, silicate mantle and crust.

However, the explosion of exoplanet research over the past decade informed a new approach to modeling the Earth's embryonic state.

"Exoplanet discoveries have given us a much greater appreciation of how common it is for just-formed planets to be surrounded by atmospheres that are rich in molecular hydrogen, H2, during their first several million years of growth," Shahar explained. "Eventually these hydrogen envelopes dissipate, but they leave their fingerprints on the young planet's composition."

Using this information, the researchers developed new models for Earth's formation and evolution to see if our home planet's distinct chemical traits could be replicated.

Using a newly developed model, the Carnegie and UCLA researchers were able to demonstrate that early in Earth's existence, interactions between the magma ocean and a molecular hydrogen proto-atmosphere could have given rise to some of Earth's signature features, such as its abundance of water and its overall oxidized state.

The researchers used mathematical modeling to explore the exchange of materials between molecular hydrogen atmospheres and magma oceans by looking at 25 different compounds and 18 different types of reactions -- complex enough to yield valuable data about Earth's possible formative history, but simple enough to interpret fully.

Interactions between the magma ocean and the atmosphere in their simulated baby Earth resulted in the movement of large masses of hydrogen into the metallic core, the oxidation of the mantle, and the production of large quantities of water.

Even if all of the rocky material that collided to form the growing planet was completely dry, these interactions between the molecular hydrogen atmosphere and the magma ocean would generate copious amounts of water, the researchers revealed. Other water sources are possible, they say, but not necessary to explain Earth's current state.

"This is just one possible explanation for our planet's evolution, but one that would establish an important link between Earth's formation history and the most common exoplanets that have been discovered orbiting distant stars, which are called Super-Earths and sub-Neptunes," Shahar concluded.

This project was part of the interdisciplinary, multi-institution AEThER project, initiated and led by Shahar, which seeks to reveal the chemical makeup of the Milky Way galaxy's most common planets -- Super-Earths and sub-Neptunes -- and to develop a framework for detecting signatures of life on distant worlds. Funded by the Alfred P. Sloan Foundation, this effort was developed to understand how the formation and evolution of these planets shape their atmospheres. This could -- in turn -- enable scientists to differentiate true biosignatures, which could only be produced by the presence of life, from atmospheric molecules of non-biological origin.

Read more at Science Daily

Learning about what happens to ecology, evolution, and biodiversity in times of mass extinction

In times of environmental upheaval, how do communities of organisms respond? When entire species are wiped out, do surviving species move in and take over, or do new species immigrate to fill the gaps?

These are questions that Sarah Brisson, Ph.D. student in UConn's Department of Earth Sciences, set out to study. This research is published in the Proceedings of the Royal Society B.

Brisson studies a mass extinction event that happened in the Late Devonian period, around 370 million years ago, with the goal of understanding how ecosystems and the communities of organisms within them respond. For this study, Brisson focused on small, shelled, ocean-dwelling creatures called brachiopods by studying fossils collected from the Appalachian Basin in New York and Pennsylvania.

"The name 'mass extinction events' captures people's attention. These are times of major changes in the environment, and how those changes impact the organisms is relevant to understanding our current environment and environmental changes," says Brisson.

In the Late Devonian, the Appalachian Basin was a shallow sea that formed in the wake of the growing mountains. Brisson says the seafloor was likely covered with brachiopods, which were abundant in the sample set. In the water, fish were also becoming more abundant, and on land, a great greening was happening, with new plants evolving for the first time in Earth's history.

"The Devonian world was very different; there were no flowering plants for millions of years. We're just setting the stage to move into the Mesozoic -- the dinosaur era -- where we have big ferns and large, woody trees," Brisson says.

In studying these ecosystem dynamics, Brisson looks at Earth as a system, with niche changes just one aspect of the entire structure.

"A niche space is an environment where an organism lives, in this case, the level of substrate disturbance and where along the depth profile the organisms most comfortable with," says Brisson.

Two concepts to consider are niche conservatism and niche evolution. Brisson explains that with niche conservatism, organisms remain in place and retain their characteristics, whereas with niche evolution organisms change and evolve in some way into preferring the new environmental parameters through time.

"In biology, there's a lot of talk about niche dynamics, and whether we see niche evolution or niche conservatism and there are not as many researchers studying this in deep time," says Brisson.

After painstakingly identifying around 20,000 brachiopod fossils and analyzing their preferences across the depth gradient, Brisson assembled a dataset and used non-metric multi-dimensional scaling (nMDS) to see where different species were grouped across the stratigraphic range over time to interpret how the organisms responded before and after the mass extinction event. Brisson says the results were a bit of a surprise.

"I saw a lot of turnover where some species went extinct, but some species survived and remained in place, and their niches are conserved. Some scientists argue this isn't the case in a large-scale extinction event and I didn't expect that niche conservatism would be shown here."

In extinction events like this one, where an estimated 35% of marine species went extinct, Brisson explains it is expected that the opening of so many niches would encourage nearby surviving species to move in to occupy the newly free space, and the results did show this happening to some extent.

"As a rule, however, we're seeing niche conservatism in this region. In cases where you might see niche evolution in the rock record, there may have been different pressures on the organisms. I think leaving that question open is important because there are many different selective pressures and not all selective pressures can be applied to every situation."

The factors that drove the extinction pulses in the Late Devonian are still debated, says Brisson. Some work, including co-author and UConn graduate Jaleigh Pier's '18 (CLAS) research, indicated a global cooling event took place. Other evidence shows widespread anoxia which could have resulted from an influx of nutrients, much like we see today with dead zones forming in offshore marine and aquatic environments.

"Part of the reason why I love the Devonian is that there are mass extinction events that have been studied so thoroughly, especially the Mesozoic mass extinction event, but there's less certainty surrounding the Late Devonian. As you're moving back through time, it's harder to be certain because some of the proxies used in the Mesozoic don't apply to the Devonian. It's a neat and dynamic time to study."

This work represents just one chapter of Brisson's dissertation, and future analyses will look at the data further, including stable isotope analysis to understand how nitrogen may have impacted this region. Peering this far into the past may shed light on the accelerating species extinctions of today.

Read more at Science Daily

A once-stable glacier in Greenland is now rapidly disappearing

As climate change causes ocean temperatures to rise, one of Greenland's previously most stable glaciers is now retreating at an unprecedented rate, according to a new study.

Led by researchers at The Ohio State University, a team found that between 2018 and 2021, Steenstrup Glacier in Greenland has retreated about 5 miles, thinned about 20%, doubled in the amount of ice it discharges into the ocean, and quadrupled in velocity. According to the study, such a rapid change is so extraordinary among Greenland ice formations that it now places Steenstrup in the top 10% of glaciers that contribute to the entire region's total ice discharge.

The study was published today in Nature Communications.

The Steenstrup Glacier is part of The Greenland Ice Sheet, a body of ice that covers nearly 80% of the world's largest island, which is also the single largest contributor to global sea rise from the cryosphere, the portion of Earth's ecosystem that includes all of its frozen water. While the region plays a crucial part in balancing the global climate system, the area is steadily shrinking as it sheds hundreds of billions of tons of ice each year because of global warming.

Over the past few decades, much of this loss has been attributed to accelerated ice discharge from tidewater glaciers, glaciers that make contact with the ocean. Many glaciologists believe that this recent uptick in ice discharge can be explained by the intrusion of warming waters that are being swept from the Atlantic into Greenlandic fjords -- critical oceanic gateways that can impact the stability of local glaciers and the health of polar ecosystems.

The research team aimed to test that theory by examining a glacier in the southeastern region of Greenland called K.I.V Steenstrups Nordre Bræ, an entity more colloquially known as the Steenstrup Glacier.

"Up until 2016, there was nothing to suggest Steenstrup was in any way interesting," said Thomas Chudley, lead author of the study, who completed this work as a research associate at the Byrd Polar and Climate Research Center. Chudley is now a Leverhulme research fellow at Durham University in the UK.

"There were plenty of other glaciers in Greenland that had retreated dramatically since the 1990s and increased their contribution to sea level rise, but this really wasn't one of them."

As far as scientists knew, Steenstrup had not only been stable for decades but was generally insensitive to the rising temperatures that had destabilized so many other regional glaciers, likely because of its isolated position in shallow waters.

It wasn't until Chudley and his colleagues compiled observational and modeling data from previous remote sensing analyses on the glacier that the team realized Steenstrup was likely experiencing melt due to anomalies in deeper Atlantic water.

"Our current working hypothesis is that ocean temperatures have forced this retreat," Chudley said. "The fact that the glacier's velocity has quadrupled in just a few years opens up new questions about how fast large ice masses can really respond to climate change."

In recent years, glaciologists have been able to use satellite data to estimate the potential volume of glacial ice stored at the poles and how it might affect current sea levels. For instance, if the Greenland Ice Sheet were to melt, Earth's sea levels could rise by nearly 25 feet. In contrast, if the ice sheet in Antarctica were to fall apart, it's possible that oceans would rise by nearly 200 feet, Chudley said.

While Greenland and Antarctica would take centuries to collapse completely, the global cryosphere has the potential to cause sea levels to rise about six feet this century if the West Antarctic Ice Sheet undergoes collapse.

As around 10% of the planet's population lives in low-lying coastal zones, Chudley said that any significant rise in sea level can cause increased risk to low-lying islands and coastal communities from storm surges and tropical cyclones.

In the United States, sea level rise poses a particular risk to coastal cities in places like Florida or Louisiana, Chudley said. But that doesn't necessarily mean it's too late to stop such a future from happening. If climate policies evolve rapidly, humans might have a chance at halting the worst of sea level rise, Chudley said.

Overall, Steenstrup's unique behavior reveals that even long-term stable glaciers are susceptible to sudden and rapid retreat as warmer waters begin to intrude and influence new environments.

While the research says continued scientific observation of the Steenstrup Glacier should be a priority, it concludes other similar glaciers also deserve attention because of their potential to retreat due to warming waters.

Understanding more about these interactions could provide key insight into how glaciers thrive in other locations around the world and even become an indicator of how these environments might change in the future.

"What's happening in Greenland right now is kind of the canary in the coal mine of what might happen in West Antarctica over the next few centuries," Chudley said. "So it would be great to be able to get into the fjord with real on-the-ground observations and see how and why Steenstrup has changed."

Read more at Science Daily

Study links 'stuck' stem cells to hair turning gray

Certain stem cells have a unique ability to move between growth compartments in hair follicles, but get stuck as people age and so lose their ability to mature and maintain hair color, a new study shows.

Led by researchers from NYU Grossman School of Medicine, the new work focused on cells in the skin of mice and also found in humans called melanocyte stem cells, or McSCs. Hair color is controlled by whether nonfunctional but continually multiplying pools of McSCs within hair follicles get the signal to become mature cells that make the protein pigments responsible for color.

Publishing in the journal Nature online April 19, the new study showed that McSCs are remarkably plastic. This means that during normal hair growth, such cells continually move back and forth on the maturity axis as they transit between compartments of the developing hair follicle. It is inside these compartments where McSCs are exposed to different levels of maturity-influencing protein signals.

Specifically, the research team found that McSCs transform between their most primitive stem cell state and the next stage of their maturation, the transit-amplifying state, and depending on their location.

The researchers found that as hair ages, sheds, and then repeatedly grows back, increasing numbers of McSCs get stuck in the stem cell compartment called the hair follicle bulge. There, they remain, do not mature into the transit-amplifying state, and do not travel back to their original location in the germ compartment, where WNT proteins would have prodded them to regenerate into pigment cells.

"Our study adds to our basic understanding of how melanocyte stem cells work to color hair," said study lead investigator Qi Sun, PhD, a postdoctoral fellow at NYU Langone Health. "The newfound mechanisms raise the possibility that the same fixed-positioning of melanocyte stem cells may exist in humans. If so, it presents a potential pathway for reversing or preventing the graying of human hair by helping jammed cells to move again between developing hair follicle compartments."

Researchers say McSC plasticity is not present in other self-regenerating stem cells, such as those making up the hair follicle itself, which are known to move in only one direction along an established timeline as they mature. For example, transit-amplifying hair follicle cells never revert to their original stem cell state. This helps explain in part why hair can keep growing even while its pigmentation fails, says Sun.

Earlier work by the same research team at NYU showed that WNT signaling was needed to stimulate the McSCs to mature and produce pigment. That study had also shown that McSCs were many trillions of times less exposed to WNT signaling in the hair follicle bulge than in the hair germ compartment, which is situated directly below the bulge.

In the latest experiments in mice whose hair was physically aged by plucking and forced regrowth, the number of hair follicles with McSCs lodged in the follicle bulge increased from 15% before plucking to nearly half after forced aging. These cells remained incapable of regenerating or maturing into pigment-producing melanocytes.

The stuck McSCs, the researchers found, ceased their regenerative behavior as they were no longer exposed to much WNT signaling and hence their ability to produce pigment in new hair follicles, which continued to grow.

By contrast, other McSCs that continued to move back and forth between the follicle bulge and hair germ retained their ability to regenerate as McSCs, mature into melanocytes, and produce pigment over the entire study period of two years.

"It is the loss of chameleon-like function in melanocyte stem cells that may be responsible for graying and loss of hair color," said study senior investigator Mayumi Ito, PhD, a professor in the Ronald O. Perelman Department of Dermatology and the Department of Cell Biology at NYU Langone Health.

"These findings suggest that melanocyte stem cell motility and reversible differentiation are key to keeping hair healthy and colored," said Ito, who is also a professor in the Department of Cell Biology at NYU Langone.

Ito says the team has plans to investigate means of restoring motility of McSCs or of physically moving them back to their germ compartment, where they can produce pigment.

For the study, researchers used recent 3D-intravital-imaging and scRNA-seq techniques to track cells in almost real time as they aged and moved within each hair follicle.

Read more at Science Daily

Apr 18, 2023

Playing hide and seek with planets

An international team of astronomers announced the first exoplanet discovered through a combined approach of direct imaging and precision measurements of a star's motion on the sky. This new method promises to improve the efficiency of exoplanet searches, paving the way for the discovery of an Earth twin.

To discover exoplanets, planets which orbit stars other than the Sun, by imaging astronomers have up until now used "blind surveys": stars are selected for imaging consider factors such as age and distance but are otherwise unbiased. However, blind surveys find planets very infrequently. Knowing where to look would help increase detection rates.

An international research team led by Subaru Telescope, the University of Tokyo, the University of Texas-San Antonio, and the Astrobiology Center of Japan, searched for hints of unknown planets in the data from the European Space Agency's Gaia mission and its predecessor, Hipparcos. The team identified a star, HIP 99770 located 133 light-years away in the constellation Cygnus, whose motion suggests that an unseen planet is gravitationally pulling on it. Direct imaging observations with the Subaru Telescope detected the planet, HIP 99770 b.

The newly discovered planet is 14-16 times more massive than Jupiter. Its orbit is just over 3 times further from its star than Jupiter is from the Sun. The planet is 10 times hotter than Jupiter, with signs of water and carbon monoxide in its atmosphere.

A decade from now, astronomers hope to image a potentially-habitable planet with a size and temperature like the Earth using observatories like the Thirty Meter Telescope (TMT). Compared with HIP 99770 b, this Earth twin will be smaller and closer to its star, traits that will make it harder to detect. But with precise motion measurements, researchers will know where to look in this game of planetary hide and seek.

From Science Daily

Teasing strange matter from the ordinary

In a unique analysis of experimental data, nuclear physicists have made the first-ever observations of how lambda particles, so-called "strange matter," are produced by a specific process called semi-inclusive deep inelastic scattering (SIDIS). What's more, these data hint that the building blocks of protons, quarks and gluons, are capable of marching through the atomic nucleus in pairs called diquarks, at least part of the time. These results come from an experiment conducted at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility.

It's a result that has been decades in the making. The dataset was originally collected in 2004. Lamiaa El Fassi, now an associate professor of physics at Mississippi State University and principal investigator of the work, first analyzed these data during her thesis project to earn her graduate degree on a different topic.

Nearly a decade after completing her initial research with these data, El Fassi revisited the dataset and led her group through a careful analysis to yield these unprecedented measurements. The dataset comes from experiments in Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF), a DOE user facility. In the experiment, nuclear physicists tracked what happened when electrons from CEBAF scatter off the target nucleus and probe the confined quarks inside protons and neutrons. The results were recently published in Physical Review Letters.

"These studies help build a story, analogous to a motion picture, of how the struck quark turns into hadrons. In a new paper, we report first-ever observations of such a study for the lambda baryon in the forward and backward fragmentation regions," El Fassi said.

In like a lambda, out like a pion

Like the more familiar protons and neutrons, each lambda is made up of three quarks.

Unlike protons and neutrons, which only contain a mixture of up and down quarks, lambdas contain one up quark, one down quark and one strange quark. Physicists have dubbed matter that contains strange quarks "strange matter."

In this work, El Fassi and her colleagues studied how these particles of strange matter form from collisions of ordinary matter. To do so, they shot CEBAF's electron beam at different targets, including carbon, iron, and lead. When a high-energy electron from CEBAF reaches one of these targets, it breaks apart a proton or neutron inside one of the target's nuclei.

"Because the proton or neutron is totally broken apart, there is little doubt that the electron interacts with the quark inside," El Fassi said.

After the electron interacts with a quark or quarks via an exchanged virtual photon, the "struck" quark(s) begins moving as a free particle in the medium, typically joining up with other quark(s) it encounters to form a new composite particle as they propagate through the nucleus. And some of the time, this composite particle will be a lambda.

But the lambda is short-lived -- after formation, it will swiftly decay into two other particles: a pion and either a proton or neutron. To measure different properties of these briefly created lambda particles, physicists must detect its two daughter particles, as well as the beam electron that scattered off the target nucleus.

The experiment that collected this data, EG2, used the CEBAF Large Acceptance Spectrometer (CLAS) detector in Jefferson Lab's Experimental Hall B. These recently published results, "First Measurement of ? Electroproduction off Nuclei in the Current and Target Fragmentation Regions," are part of the CLAS collaboration, which involves almost 200 physicists worldwide.

SIDIS

This work is the first to measure the lambda using this process, which is known as semi-inclusive deep inelastic scattering, in the forward and backward fragmentation regions. It's more difficult to use this method to study lambda particles, because the particle decays so quickly, it can't be measured directly.

"This class of measurement has only been performed on protons before, and on lighter, more stable particles," said coauthor William Brooks, professor of physics at Federico Santa María Technical University and co-spokesperson of the EG2 experiment.

The analysis was so challenging, it took several years for El Fassi and her group to re-analyze the data and extract these results. It was her thesis advisor, Kawtar Hafidi, who encouraged her to pursue the investigation of the lambda from these datasets.

"I would like to commend Lamiaa's hard work and perseverance in dedicating years of her career working on this," said Hafidi, associate laboratory director for physical sciences and engineering at Argonne National Lab and co-spokesperson of the EG2 experiment. "Without her, this work would not have seen fruition."

"It hasn't been easy," El Fassi said. "It's a long and time-consuming process, but it was worth the effort. When you spend so many years working on something, it feels good to see it published."

El Fassi began this lambda analysis when she herself was a postdoc, a couple of years prior to becoming an assistant professor at Mississippi State University. Along the way, several of her own postdocs at Mississippi State have helped extract these results, including coauthor Taya Chetry.

"I'm very happy and motivated to see this work being published," said Chetry, who is now a postdoctoral researcher at Florida International University.

Two for one

A notable finding from this intensive analysis changes the way physicists understand how lambdas form in the wake of particle collisions.

In similar studies that have used semi-inclusive deep inelastic scattering to study other particles, the particles of interest usually form after a single quark was "struck" by the virtual photon exchanged between the electron beam and the target nucleus. But the signal left by lambda in the CLAS detector suggests a more packaged deal.

The authors' analysis showed that when forming a lambda, the virtual photonhas been absorbed part of the time by a pair of quarks, known as a diquark, instead of just one. After being "struck," this diquark went on to find a strange quark and forms a lambda.

"This quark pairing suggests a different mechanism of production and interaction than the case of the single quark interaction," Hafidi said.

A better understanding of how different particles form helps physicists in their effort to decipher the strong interaction, the fundamental force that holds these quark-containing particles together. The dynamics of this interaction are very complicated, and so is the theory used to describe it: quantum chromodynamics (QCD).

Comparing measurements to models of QCD's predictions allows physicists to test this theory. Because the diquark finding differs from the model's current predictions, it suggests something about the model is off.

"There is an unknown ingredient that we don't understand. This is extremely surprising, since the existing theory can describe essentially all other observations, but not this one," Brooks said. "That means there is something new to learn, and at the moment, we have no clue what it could be."

To find out, they'll need even more measurements.

Data for EG2 were collected with 5.014 GeV (billion electron-volt) electron beams in the CEBAF's 6 GeV era. Future experiments will use electron beams from the updated CEBAF, which now extend up to 11 GeV for Experimental Hall B, as well as an updated CLAS detector known as CLAS12, to continue studying the formation of a variety of particles, including lambdas, with higher-energy electrons.

The upcoming Electron-Ion Collider (EIC) at DOE's Brookhaven National Laboratory will also provide a new opportunity to continue studying this strange matter and quark pairing structure of the nucleon with greater precision.

"These results lay the groundwork for upcoming studies at the upcoming CLAS12 and the planned EIC experiments, where one can investigate the diquark scattering in greater detail," Chetry said.

Read more at Science Daily

The surprising science behind long-distance bird migration

A team of scientists led by researchers at the University of Massachusetts Amherst has recently made a surprising discovery, with the help of a wind tunnel and a flock of birds. Songbirds, many of which make twice-yearly, non-stop flights of more than 1,000 miles to get from breeding range to wintering range, fuel themselves by burning lots of fat and a surprising amount of the protein making up lean body mass, including muscle, early in the flight. This flips the conventional wisdom on its head, which had assumed that migrating birds only ramped up protein consumption at the very end of their journeys, because they would need to use every ounce of muscle for wing-flapping, not fuel. The results appeared recently in the Proceedings of the National Academy of Sciences.

"Birds are amazing animals," says Cory Elowe, the paper's lead author and a postdoctoral researcher in biology at UMass Amherst, where he received his Ph.D. "They are extreme endurance athletes; a bird that weighs half an ounce can fly, non-stop, flapping for 100 hours at a time, from Canada to South America. How is this possible? How do they fuel their flight?"

For a very long time, biologists assumed that birds fueled such feats of endurance by burning fat reserves. And indeed, fat is an important part of migratory birds' secret mix. "The birds in our tests burned fat at a consistent rate throughout their flights," says Elowe. "But we also found that they burn protein at an extremely high rate very early in their flights, and that the rate at which they burn protein tapers off as the duration of the flight increases."

"This is a new insight," says Alexander Gerson, associate professor of biology at UMass Amherst and the paper's senior author. "No one has been able to measure protein burn to this extent in birds before."

"We knew that birds burned protein, but not at this rate, and not so early in their flights," continues Gerson. "What's more, these small songbirds can burn 20% of their muscle mass and then build it all back in a matter of days."

To make this breakthrough, Elowe had help from the bird banding operators at Long Point Bird Observatory, in Ontario, along the northern shore of Lake Erie. Every fall, millions of birds gather near the observatory on their journey to their wintering grounds -- including the blackpoll warbler, a small songbird that travels thousands of miles during its migration. After capturing 20 blackpolls and 44 yellow-rumped warblers -- a shorter distance migrant -- using mist nets, Elowe and his colleagues then transported the birds to the Advanced Facility for Avian Research at Western University, which has a specialized wind tunnel built specifically for observing birds in flight.

Elowe measured the birds' fat and lean body mass pre-flight, then, when the sun set, let the birds free in the wind tunnel. Because the birds naturally migrate at night, Elowe and his colleagues would then stay awake -- at one point, for 28 hours -- watching for when a bird would decide to rest. At that point, the researchers would collect the bird and again measure its fat and lean body mass content, comparing them with the pre-flight measurements.

"One of the biggest surprises was that every bird still had plenty of fat left when it chose to end its flight," says Elowe. "But their muscles were emaciated. Protein, not fat, seems to be a limiting factor in determining how far birds can fly."

The researchers still don't quite know why the birds are burning such vast stores of protein so early in their journeys, but the possible answers open up a wide range of future research avenues.

"How exactly is it possible to burn up your muscles and internal organs, and then rebuild them as quickly as these birds do," wonders Gerson. "What insights into the evolution of metabolism might these birds yield?"

Read more at Science Daily

Swimming secrets of prehistoric reptiles unlocked by new study

Some of the most extraordinary body transformations in evolution have occurred in animals that adapted to life in water from land-living ancestors, such as modern whales, turtles and seals. During the Mesozoic, from 252 to 66 million years ago, while the dinosaurs stomped about on land, many groups of reptiles took to the seas, such as the iconic ichthyosaurs, plesiosaurs, crocodiles and mosasaurs.

In a new paper, published in the journal Palaeontology, a Bristol team of palaeobiologists used state-of-the-art statistical methods to perform a large-scale quantitative study, the first of its kind, on the locomotion of Mesozoic marine reptiles.

The researchers collected measurements from 125 fossilised skeletons, and used these to explore changes in swimming styles within lineages and through time, discovering that there was no explosive radiation at the beginning of the Mesozoic, but a gradual diversification of locomotory modes, which peaked in the Cretaceous period.

Lead author Dr Susana Gutarra of Bristol's School of Earth Sciences said: "Changes in anatomy in land-to-sea transitions are intimately linked to the evolution of swimming. For example, sea lions' flippers have relatively short forearm and large hands, very different from the walking legs of their ancestors. The rich fossil record of Mesozoic marine reptiles provided great opportunity to study these transitions at a large scale."

Co-author Beatrice Heighton, said: "We included measurements from living aquatic animals, such as otters, seals and turtles, of which we know their swimming behaviour. This is very important to provide a functional reference for the ancient species, with unknown swimming modes."

In the aftermath of the end-Permian extinction, about 250 million years ago, various groups of reptiles became aquatic hunters, populating the early Mesozoic seas.

Co-author Dr Tom Stubbs said: "After this devastating event, there was a gradual diversification of locomotory modes, which contrasts with the rapid radiation described previously for feeding strategies. This is fascinating because it suggests a 'head-first' pattern of evolution in certain lineages."

This paper sheds light into the swimming of specific groups. Dr Ben Moon explained: "Ichthyosaurs were highly specialised for aquatic locomotion from very early in their evolution. This includes their close relatives, the hupehsuchians, which had a morphology unlike any other known aquatic tetrapod. Further, we see overlap between mosasaurs and ichthyosaurs, which is indicative that mosasaurs evolved a swimming mode by oscillating flukes, different from the eel-like body undulation suggested in the past.

"In contrast, we don't find evidence of convergence between ichthyosaurs and metriorhynchids (the highly aquatic crocodyliform thalattosuchians). This group retained quite primitive-looking hindlimbs, which seems incompatible with swimming by fluke oscillation."

This study also delves into the evolution of size, a feature related to locomotion, animal physiology and ocean productivity. Professor Mike Benton said: "We know that transition to life in water is usually accompanied by an increase in body mass, as seen in cetaceans, and one of our previous studies shows that large sizes benefit aquatic animals in reducing the mass-specific costs of drag. Thus, it was essential to explore this trait in the wider ensemble of Mesozoic marine reptiles."

Dr Gutarra added: "Body size follows a similar trend to the diversification of locomotory modes, and the widest spread of body size also occurred in the Cretaceous, confirming a strong connection between the two. The rate of increase and the maximum limits to body size seems to vary a lot between groups. This is a fascinating observation. We need to explore further what factors influence and limit the increase in body mass in each group."

Read more at Science Daily

Apr 17, 2023

New exoplanet discovered

An international research team led by UTSA Associate Professor of Astrophysics Thayne Currie has made a breakthrough in accelerating the search for new planets.

In a paper slated for publication April 14 in Science, Currie reports the first exoplanet jointly discovered through direct imaging and precision astrometry, a new indirect method that identifies a planet by measuring the position of the star it orbits. Data from the Subaru Telescope in Hawai`i and space telescopes from the European Space Agency (ESA) were integral to the team's discovery.

An exoplanet -- also called an extrasolar planet -- is a planet outside a solar system that orbits another star. With direct imaging, astronomers can see an exoplanet's light in a telescope and study its atmosphere. However, only about 20 have been directly imaged over the past 15 years.

By contrast, indirect planet detection methods determine a planet's existence through its effect on the star it orbits. This approach can provide detailed measurements of the planet's mass and orbit.

Combining direct and indirect methods to examine a planet's position provides a more complete understanding of an exoplanet, Current says.

"Indirect planet detection methods are responsible for most exoplanet discoveries thus far. Using one of these methods, precision astrometry, told us where to look to try to image planets. And, as we found out, we can now see planets a lot easier," said Currie.

The newly discovered exoplanet, called HIP 99770 b, is about 14 to 16 times the mass of Jupiter and orbits a star that is nearly twice as massive as the Sun. The planetary system also shares similarities with the outer regions of our solar system. HIP 99770 b receives about as much light as Jupiter, our solar system's most massive planet, receives from the Sun. Its host star is surrounded by icy debris left over from planet formation, similar to our solar system's Kuiper belt, the ring of icy objects observed around the Sun.

Currie and team used the Hipparcos-Gaia Catalogue of Accelerations to advance their discovery of HIP 99770 b. The catalogue consists of data from ESA's Gaia mission and Hipparcos, Gaia's predecessor, providing a 25-year record of accurate star positions and motions. It revealed that the star HIP 99770 is likely being accelerated by the gravitational pull of an unseen planet.

The team then used the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument, which is permanently installed at the focus of the Subaru Telescope in Hawai`i, to image and confirm the existence of HIP 99770 b.

Read more at Science Daily

Researchers discover tiny galaxy with big star power using James Webb telescope

Using first-of-their-kind observations from the James Webb Space Telescope, a University of Minnesota Twin Cities-led team looked more than 13 billion years into the past to discover a unique, minuscule galaxy that generated new stars at an extremely high rate for its size. The galaxy is one of the smallest ever discovered at this distance—around 500 million years after the Big Bang—and could help astronomers learn more about galaxies that were present shortly after the Universe came into existence.

The paper is published in Science, one of the world's top peer-reviewed academic journals.

The University of Minnesota researchers were one of the first teams to study a distant galaxy using the James Webb Space Telescope, and their findings will be among the first ever published.

“This galaxy is far beyond the reach of all telescopes except the James Webb, and these first-of-their-kind observations of the distant galaxy are spectacular,” said Patrick Kelly, senior author of the paper and an assistant professor in the University of Minnesota School of Physics and Astronomy. “Here, we’re able to see most of the way back to the Big Bang, and we've never looked at galaxies when the universe was this young in this level of detail. The galaxy’s volume is roughly a millionth of the Milky Way’s, but we can see that it’s still forming the same numbers of stars each year.”

The James Webb telescope can observe a wide enough field to image an entire galaxy cluster at once. The researchers were able to find and study this new, tiny galaxy because of a phenomenon called gravitational lensing—where mass, such as that in a galaxy or galaxy cluster, bends and magnifies light. A galaxy cluster lens caused this small background galaxy to appear 20 times brighter than it would if the cluster were not magnifying its light.

The researchers then used spectroscopy to measure how far away the galaxy was, in addition to some of its physical and chemical properties. Studying galaxies that were present when the Universe was this much younger can help scientists get closer to answering a huge question in astronomy regarding how the Universe became reionized.

“The galaxies that existed when the Universe was in its infancy are very different from what we see in the nearby Universe now,” explained Hayley Williams, first author on the paper and a Ph.D. student at the Minnesota Institute for Astrophysics. “This discovery can help us learn more about the characteristics of those first galaxies, how they differ from nearby galaxies, and how the earlier galaxies formed.”

The James Webb telescope can collect about 10 times as much light as the Hubble Space Telescope and is much more sensitive at redder, longer wavelengths in the infrared spectrum. This allows scientists to access an entirely new window of data, the researchers said.

“The James Webb Space Telescope has this amazing capability to see extremely far into the universe,” Williams said. “This is one of the most exciting things about this paper. We're seeing things that previous telescopes would have ever been able to capture. It’s basically getting a snapshot of our universe in the first 500 million years of its life.”

Read more at Science Daily

Family tree of 'boring' butterflies reveals they're anything but

Walk a short distance through the Amazon Rainforest, and you might witness what look like dead leaves launch from the ground and fly off into the understory. These masters of disguise are euptychiines, one of the most diverse and least understood groups of butterflies in the American Tropics.

There are as many as 100 co-occurring euptychiine species in the rainforests of Peru and Brazil, but even the most seasoned butterfly experts have a hard time telling them apart.

"They're one of the groups that often get called 'brown, boring butterflies,'" said André Freitas, a biology professor at the State University of Campinas in Brazil. "They aren't very attractive to collectors or researchers, and even distantly related species can look very similar. The early naturalists had no way to accurately classify them."

Freitas is a co-author on a new study that adds some much-needed definition to what has remained, up until now, a black hole of butterfly diversity. The German entomologist Jacob Hübner was the first to describe the group in the early 1800s, when he lumped the few species then known into a handful genera based on similar appearance.

Using DNA, Freitas and his colleagues show there are at least 70 Euptychiina genera, containing more than 500 species. Their results also suggest there are at least 130 unnamed species in the group awaiting scientific description.

The study is the result of a project more than a decade in the making, initially conceived by Keith Willmott, director of the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History. In 2009, Willmott reached out to Freitas and other researchers who'd taken a stab at individually sorting through euptychiine butterflies piecemeal and proposed they instead combine their efforts.

Before researchers could make heads or tails of euptychiine diversity, they first needed a sense of just how many groups there were and how they were related to each other.

"The way people would typically work on this kind of problem would be to divide and conquer, but that doesn't work for euptychiines, because there are very few unifying features among species that you can use to define groups," Willmott said.

Instead, a coalition of international researchers focused on studying as many euptychiine species as they could lay their hands on. They examined more than 60,000 specimens from museums in Europe and North and South America and collected euptychiine butterflies throughout their range, from the foothills of the Andes in Ecuador to the Atlantic Forest in Southeastern Brazil.

In the process, they discovered more than 100 new species, many of which were hiding in plain sight, concealed by their close resemblance to each other.

"A recent example is a large butterfly that used to be known as Pseudodebis celia from western Ecuador, which turned out to be four separate species," Willmott said. "These are big butterflies. It's hard to imagine these kinds of species are still escaping detection."

Not all euptychiines have evolved to blend in. Several species have bright blue scales or blazing orange eyespots, which might seem like it'd make them easy to classify. But closer inspection reveals these color patterns can be deceptive as well. Results of the study's genetic analysis show, for example, that multiple, Euptychiines have transformed their wings into blue frescoes, making them appear superficially similar.

Mimicry is often the primary suspect when unrelated butterflies have a similar appearance. Predators learn to avoid species with toxic, bitter-tasting compounds, like Monarchs (Danaus plexippus). With a little false advertising, species that lack these compounds can still deter predators by copying the colors and patterns of genuinely toxic butterflies.

But according to Willmott, this likely isn't the case for euptychiines. "As far as we know, they're not unpalatable or protected against predators in any way. It looks like mimicry, but there's really no basis for it. It's a fascinating mystery that needs study."

Blue euptychiines can play further tricks on butterfly experts -- sometimes, the color is only present in some individuals of a given species.

"In most cases, the males are colorful, and the females are brown," said Marianne Espelend, a curator at the Leibniz Institute for the Analysis of Biodiversity and lead author on the study.

This mismatch has led to several cases of mistaken identity. A brown species from French Guiana described in 2012 was later determined to be the incognito female half of a well-known species discovered a century earlier. This triggered inspection of other blue species, and discovery of similar problems.

The new classification provided by this study will help researchers pin down the exact identity of familiar euptychiines and shorten the long queue of species in the group that have yet to be given a scientific name.

It also sets the stage for scientific forays into other aspects of euptychiine biology that experts are just now beginning to understand, said Freitas, reciting a litany of unknowns that can now be thoroughly investigated.

"We know that several species have scales that release scents to attract females, but we have no idea what types of chemicals are involved; the males of some species make an audible clicking sound, but we don't know how they do it; and I can count on my hand the number of times I've been able to find euptychiine caterpillars in the wild, of which we know very little."

Read more at Science Daily

Scientists achieve promising results towards restoring vision in blindness caused by cellular degeneration in the eye

A preclinical study using stem cells to produce progenitor photoreceptor cells -- light-detecting cells found in the eye -- and then transplanting these into experimental models of damaged retinas has resulted in significant vision recovery. This finding, by scientists at Duke-NUS Medical School, the Singapore Eye Research Institute and the Karolinska Institute in Sweden, marks a first step towards potentially restoring vision in eye diseases characterised by photoreceptor loss.

"Our laboratory has developed a novel method that enables the production of photoreceptor progenitor cells resembling those in human embryos," said Assistant Professor Tay Hwee Goon, first author of the study from Duke-NUS' Centre for Vision Research. "Transplantation of these cells into experimental models has yielded partial restoration of the retinal function."

The degeneration of photoreceptors in the eye is a significant cause of declining vision that can eventually lead to blindness and for which there is currently no effective treatment. Photoreceptor degeneration occurs in a variety of inherited retinal diseases, such as retinitis pigmentosa -- a rare eye disease that breaks down cells in the retina over time and eventually causes vision loss -- and age-related macular degeneration, a leading cause of vision impairment worldwide.

Asst Prof Tay and her team developed a procedure to grow human embryonic stem cells in the presence of purified laminin proteins that are involved in normal development of human retinas. In the presence of the laminins, stem cells could be directed to differentiate into photoreceptor progenitor cells responsible for converting light into signals that are sent to the brain.

When these cells were transplanted into damaged retinas, the preclinical models showed significant recovery of vision. A diagnostic test called electroretinogram also identified significant recovery in the retinas via electrical activity in the retina in response to a light stimulus. The transplanted cells established connections with surrounding retinal cells and nerves in the inner retina. They also survived and functioned for many weeks after transplantation.

Moving forward, the team hopes to refine their method to make it simpler and achieve more consistent results than earlier attempts to explore stem cell therapy for photoreceptor cell replacement.

"It is exciting to find these results, which suggest a promising route towards using stem cells to treat those forms of visual deterioration and blindness caused by the loss of photoreceptors," said Dr Helder Andre, Head of Molecular and Cellular Research from Karolinska Institute's Department of Clinical Neuroscience and a senior author of the study.

Associate Professor Enrico Petretto, Director of the Centre for Computational Biology at Duke-NUS and the study's bioinformatics analysis lead, added: "Our method may also be useful for understanding the molecular and cellular pathways that drive the progression of macular degeneration, perhaps leading to the development of other therapeutic approaches."

The next challenge for the researchers is to explore the efficacy of their method in models of photoreceptor degeneration that more closely match the human condition.

"If we get promising results in our future studies, we hope to move to clinical trials in patients," said Professor Karl Tryggvason, from Duke-NUS' Cardiovascular and Metabolic Disorders Programme, and the corresponding author of the study. "That would be an important step towards for being able to reverse damage of the retina and restore vision."

Read more at Science Daily