Astronomers capture red supergiant’s death throes

Artistic illustrations of a red supergiant exploding.
Credit: W.M. Keck Observatory/Adam Makarenko.

For the first time ever, astronomers have imaged in real time the dramatic end to a red supergiant’s life — watching the massive star’s rapid self-destruction and final death throes before collapsing into a type II supernova.

Led by researchers at Northwestern University and the University of California, Berkeley (UC Berkeley), the team observed the red supergiant during its last 130 days leading up to its deadly detonation.

The discovery defies previous ideas of how red supergiant stars evolve right before exploding. Earlier observations showed that red supergiants were relatively quiescent before their deaths — with no evidence of violent eruptions or luminous emissions. The new observations, however, detected bright radiation from a red supergiant in the final year before exploding. This suggests at least some of these stars must undergo significant changes in their internal structure, which then result in the tumultuous ejection of gas moments before they collapse.

“This is a breakthrough in our understanding of what massive stars do moments before they die,” said Wynn Jacobson-Galán, the study’s lead author. “Direct detection of pre-supernova activity in a red supergiant star has never been observed before in an ordinary type II supernova. For the first time, we watched a red supergiant star explode.”

Animal vaccines with self-spreading viruses

How a self-spreading vaccine could work in a bat population. Bats directly injected with a self-spreading vaccine passively spread the lab-modified viral vaccine to other bats they encounter over time (T1->T2->T3…) gradually building up population-wide immunity.  In this example bats are used, but any mammal species that lives in groups could theoretically be targeted to rapidly vaccinate whole populations.

Credit: Derek Caetano-Anolles

Vaccines for animals based on viruses that spread on their own are being developed in Europe and the U.S

Since the first lab-modified virus capable of replication was generated in 1974, an evidence-based consensus has emerged that many changes introduced into viral genomes are likely to prove unstable if released into the environment. On this basis, many virologists would question the release of genetically modified viruses that retain the capacity to spread between individual vertebrate hosts. Researchers from Germany, South Africa, the United Kingdom and the United States now point out in a policy piece that despite these concerns, self-spreading vaccines for animals are being researched in Europe and the US. They are intended to limit the spread of animal diseases or disease spillover to humans.

The Largest Suite of Cosmic Simulations for AI Training

The CAMELS project (Cosmology and Astrophysics with MachinE Learning Simulations) combines over 4,000 cosmological simulations, millions of galaxies, and 350 terabytes of data to decipher secrets of the universe.

Totaling 4,233 universe simulations, millions of galaxies and 350 terabytes of data, a new release from the CAMELS project is a treasure trove for cosmologists. CAMELS — which stands for Cosmology and Astrophysics with MachinE Learning Simulations — aims to use those simulations to train artificial intelligence models to decipher the universe’s properties.

Scientists are already using the data, which is free to download, to power new research, says project co-leader Francisco Villaescusa-Navarro, a research scientist with the Simons Foundation’s CMB (Cosmic Microwave Background) Analysis and Simulation group.

Villaescusa-Navarro leads the project with associate research scientists at the Flatiron Institute’s Center for Computational Astrophysics (CCA) Shy Genel and Daniel Anglés-Alcázar, who is also a UConn Associate Professor of Physics.

“Machine learning is revolutionizing many areas of science, but it requires a huge amount of data to exploit,” says Anglés-Alcázar. “The CAMELS public data release, with thousands of simulated universes covering a broad range of plausible physics, will provide the galaxy formation and cosmology communities with a unique opportunity to explore the potential of new machine-learning algorithms to solve a variety of problems.”

New year's mission to start new phase of exoplanet research

Source: University of Birmingham

A mission to one of the coldest and most remote places on earth will enable a new phase in the search for distant planetary systems.

University of Birmingham PhD researcher Georgina Dransfield has travelled to the Franco-Italian Concordia Research Station in Antarctica, to oversee the installation of a new state-of-the-art camera at the ASTEP (Antarctic Search for Transiting ExoPlanets) telescope.

The new instrument will enable scientists to see a much wider range of planets orbiting suns outside the Solar system, broadening our search for planets capable of hosting life.

The ASTEP telescope detects signals from distant planetary systems using the ‘transit’ method, measuring the slight dips in brightness that occur when a planet passes between Earth and its host star.

Purchased with support from the Science and Technology Facilities Council and from the European Research Council, the telescope’s new camera is sensitive to the reddest wavelengths in the spectrum. This means it can spot the smallest stars in our galaxy, which are colder, fainter and therefore redder.

“It is easier to detect smaller planets orbiting these small stars, so we have a good chance of being able to detect planets of a similar size and temperature to the Earth, thanks to this new camera,” explained Georgina.

The camera also has a ‘blue’ channel, so can see in two colors at once. This will enable astronomers to distinguish planetary signals from parasitic signals produced by other astrophysical phenomena, enabling new planets to be confirmed more rapidly and efficiently.

Ocean plastic is creating new communities of life on the high seas

Anika Albrecht of Ocean Voyages Institute collecting plastic.
Photo credit: Ocean Voyages Institute

Coastal plants and animals have found a new way to survive in the open ocean—by colonizing plastic pollution. A commentary published in Nature Communications reported coastal species growing on trash hundreds of miles out to sea in the North Pacific Subtropical Gyre, more commonly known as the “Great Pacific Garbage Patch.”

The authors, including two oceanographers from the University of Hawaiʻi at Mānoa School of Ocean and Earth Science and Technology (SOEST), call these communities neopelagic. “Neo” means new, and “pelagic” refers to the open ocean, as opposed to the coast.

For marine scientists, the very existence of this “new open ocean” community is a paradigm shift. Plastic is providing new habitat in the open ocean. And somehow, coastal rafters are finding food.

Now, scientists have to wrestle with how these coastal rafters could shake up the environment. The open ocean has plenty of its own native species, which also colonize floating debris. The arrival of new coastal neighbors could disrupt ocean ecosystems that have remained undisturbed for millennia. Vast colonies of coastal species floating in the open ocean for years at a time could act as a new reservoir, giving coastal rafters more opportunities to invade new coastlines.

Neuromuscular junction, how’s that function?

Illustration of a neuromuscular junction. Credit: Wikimedia Commons

The neuromuscular junction—where nerves and muscle fibers meet—is an essential synapse for muscle contraction and movement. Improper function of these junctions can lead to the development of progressive neuromuscular diseases, some of which have no effective treatment (like Lou Gehrig’s disease). Now, NIBIB-funded researchers have found a way to model the human neuromuscular junction by growing these synapses in a lab, which could accelerate novel treatments for neuromuscular diseases.

“Traditionally, studies of the neuromuscular junction rely on small animal models, but the human synapse has key differences, ultimately limiting the utility of animal studies,” said David Rampulla, Ph.D., director of the division of Discovery Science & Technology at NIBIB. “Here, the study authors have developed a method to evaluate the neuromuscular junction using human 3D tissue models, which enables a more accurate representation of human disease.”

The neuromuscular junction is essentially comprised of two different types of cells: skeletal muscle cells and a type of nerve cell called motor neurons. Motor neurons are covered with ion channels, which open in response to electrical signals from the brain. Once these ion channels are open, a series of cascading reactions allows the signal to reach the skeletal muscle cells, which ultimately results in muscle contraction. Therefore, in order to generate a 3D model of the human neuromuscular junction, the researchers had to acquire and grow both these types of cells. They accomplished this by either using a muscle biopsy from a donor, from which muscle cells were isolated and neuron cells were genetically derived, or by using human stem cells which were genetically modified to make both cell types.

Scientists develop a novel strategy for sustainable post-lithium-ion batteries

Scientists astounded by performance of sustainable batteries with far-reaching implications for e-vehicles and devices.

Researchers at Bristol have developed high-performance sodium and potassium ion batteries using sustainably sourced cellulose.

Scientists at the Bristol Composites Institute have developed a novel controllable unidirectional ice-templating strategy which can tailor the electrochemical performances of next-generation post-lithium-ion batteries with sustainability and large-scale availability. The paper is published in the journal Advanced Functional Materials.

There is a rapidly increasing demand for sustainable, ethical and low-cost energy-storage. This is due in part to the drive towards developing battery-powered transport systems – mostly replacing petrol and diesel-based engines with electric vehicles – but also for hand-held devices such as mobile phones. Currently these technologies largely rely on lithium-ion batteries.

Batteries have two electrodes and a separator, with what is called an electrolyte between them which carries the charge. There are several problems associated with using lithium for these batteries, including build-up of the metal inside the devices which can lead to short circuits and overheating.

Alternatives to lithium, such as sodium and potassium batteries have not historically performed as well in terms of their rate performance and the ability to use them lots of times. This inferior performance is due to the larger sizes of sodium and potassium ions, and their ability to move through the porous carbon electrodes in the batteries.

Another issue associated with these batteries is they cannot be easily disposed of at end-of-life, as they use materials that are not sustainable. The cost of the materials is also a factor and there is a need to provide cheaper sources of stored energy.

Seeing the plasma edge of fusion experiments in new ways with artificial intelligence

Visualized are two-dimensional pressure fluctuations within a larger three-dimensional magnetically confined fusion plasma simulation. With recent advances in machine-learning techniques, these types of partial observations provide new ways to test reduced turbulence models in both theory and experiment.
Credit: Plasma Science and Fusion Center.

To make fusion energy a viable resource for the world’s energy grid, researchers need to understand the turbulent motion of plasmas: a mix of ions and electrons swirling around in reactor vessels. The plasma particles, following magnetic field lines in toroidal chambers known as tokamaks, must be confined long enough for fusion devices to produce significant gains in net energy, a challenge when the hot edge of the plasma (over 1 million degrees Celsius) is just centimeters away from the much cooler solid walls of the vessel.

Abhilash Mathews, a PhD candidate in the Department of Nuclear Science and Engineering working at MIT’s Plasma Science and Fusion Center (PSFC), believes this plasma edge to be a particularly rich source of unanswered questions. A turbulent boundary, it is central to understanding plasma confinement, fueling, and the potentially damaging heat fluxes that can strike material surfaces — factors that impact fusion reactor designs.

To better understand edge conditions, scientists focus on modeling turbulence at this boundary using numerical simulations that will help predict the plasma's behavior. However, “first principles” simulations of this region are among the most challenging and time-consuming computations in fusion research. Progress could be accelerated if researchers could develop “reduced” computer models that run much faster, but with quantified levels of accuracy.

Urban gardens are a dependable food source for pollinators through the year

A nectar-rich garden in Westbury Park (Bristol).
Credit: Nick Tew

Gardens in cities provide a long and continuous supply of energy-rich nectar from March to October, scientists at the University of Bristol have found.

Despite huge garden-to-garden variation in both the quantity and timing of nectar production, pollinators are guaranteed a reliable food supply if they visit multiple gardens. This contrasts with previous studies on farmland, where pollinators are exposed to boom-and-bust cycles of nectar production with clear seasonal gaps.

This means the actions of many independent gardeners result in the emergent property of a stable and diverse provision of food for city pollinators.

PhD student Nick Tew from the School of Biological Sciences said: “We measured the amount of nectar produced by flowers in 59 residential gardens in Bristol. We found that individual gardens vary in both how much food they provide and when they provide it during the year. However, because flying pollinators like bees can visit many different gardens, they are likely to be able to find food in residential neighborhoods whenever they need it.

“We knew that gardens were important habitats for pollinators, providing 85% of nectar sugar in urban landscapes and a great diversity of flowering plants. However, we did not know how nectar production varied between individual gardens or through the months of the year. It is particularly important to understand garden-to-garden variation to advise how best to collectively manage our gardens for pollinators.”

The variation between gardens was extreme, ranging from 2g to 1.7kg of nectar sugar through the year and this was not determined by the size of the garden but rather by how people chose to manage their gardens.

Superbug MRSA arose in hedgehogs long before clinical use of antibiotics

Scientists have found evidence that a type of the antibiotic resistant superbug MRSA arose in nature long before the use of antibiotics in humans and livestock, which has traditionally been blamed for its emergence.

Staphylococcus aureus first developed resistance to the antibiotic methicillin around 200 years ago, according to a large international collaboration including the University of Cambridge, the Wellcome Sanger Institute, Denmark’s Serum Statens Institut, University of Oxford and the Royal Botanic Gardens, Kew, which has traced the genetic history of the bacteria.

They were investigating the surprising discovery - from hedgehog surveys from Denmark and Sweden - that up to 60% of hedgehogs carry a type of MRSA called mecC-MRSA. The new study also found high levels of MRSA in swabs taken from hedgehogs across their range in Europe and New Zealand.

The researchers believe that antibiotic resistance evolved in Staphylococcus aureus as an adaptation to having to exist side-by-side on the skin of hedgehogs with the fungus Trichophyton erinacei, which produces its own antibiotics.

The resulting methicillin-resistant Staphylococcus aureus is better known as the superbug MRSA. The discovery of this centuries-old antibiotic resistance predates antibiotic overuse in medical and agricultural settings.

'Using sequencing technology we have traced the genes that give mecC-MRSA its antibiotic resistance all the way back to their first appearance, and found they were around in the nineteenth century,' said Dr Ewan Harrison, a researcher at the Wellcome Sanger Institute and University of Cambridge and a senior author of the study.