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Cheating Death: The Immortal Life Cycle of Turritopsis

Cheating Death: The Immortal Life Cycle of Turritopsis | Amazing Science | Scoop.it

While colonial animals can have their immortality, solitary individuals are doomed to die. Hydrozoan cnidarians usually have a complex life cycle, wherein a colonial stage leads to the sexually mature, solitary, adult stage. Eggs and sperm from solitary, sexual, adult medusa (jellyfish) develop into an embryo and planula larva, and they then form the colonial polyp stage. Medusae are formed asexually from polyps. These medusae have a limited lifespan and die shortly after releasing their gametes.

 

The hydrozoan Turritopsis nutricula has evolved a remarkable variation on this theme, and in so doing appears to have achieved immortality. The solitary medusa of this species can revert to its polyp stage after becoming sexually mature (Bavestrello et al., 1992; Piraino et al., 1996). In the laboratory, 100% of these medusae regularly undergo this change. Thus, it is possible that organismic death does not occur in this species!

 

How does Turritopsis accomplish this feat? It can do this because it can alter the differentiated state of a cell, transforming it into another cell type. Such a phenomenon is called transdifferentiation, and it is usually seen only when parts of an organ regenerate. However, it appears to occur normally in theTurritopsis life cycle (Figure 2). In this transdifferentiation process, the medusa is transformed into the stolons and polyps of a hydroid colony. First, the umbrella everts and the tentacles and mesoglea (the middle layer) are resorbed. The everted medusa attach to the substrate by the end that had been at the opposite end of the umbrella, and spawning occurs shortly thereafter. The cnidarian then secretes a perisarc (stolon covering) and stolons. Two days after the stolons are first seen, polyps differentiate. These polyps feed on zooplankton and soon are budding off new medusae.

 

The cells that accomplish the building of a new stolon are probably those of the exumbrella (the upper portion of the jellyfish dome). Transformation into stolons only occurs in fragments that contain tissues of the exumbrella and the ring canals, and the exumbrella tissue is the only tissue of the medusa that can transdifferentiate into the perisarc-secreting epidermal tissue of the stolons (Piraino et al., 1996). (The endoderm of the ring canals probably becomes the endoderm of the stolon and polyps.) It is not known whether the sensory cells, myoepithelial cells, and cnidocytes are derived from the exumbrella or the endodermal component.

 

Turritopsis nutricula is the first case in which a metazoan is capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage. Thus, it appears that it has cheated death and is a potentially immortal, solitary metazoan.

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Unlimited, at-home coronavirus testing for your organization | Amazing Science | Scoop.it

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NASA Has Selected Two Missions to Study ‘Lost Habitable’ World of Venus

NASA Has Selected Two Missions to Study ‘Lost Habitable’ World of Venus | Amazing Science | Scoop.it
NASA has selected two new missions to Venus, Earth’s nearest planetary neighbor.

 

Part of NASA’s Discovery Program, the missions aim to understand how Venus became an inferno-like world when it has so many other characteristics similar to ours – and may have been the first habitable world in the solar system, complete with an ocean and Earth-like climate.

 

These investigations are the final selections from four mission concepts NASA picked in February 2020 as part of the agency’s Discovery 2019 competition. Following a competitive, peer-review process, the two missions were chosen based on their potential scientific value and the feasibility of their development plans. The project teams will now work to finalize their requirements, designs, and development plans.

 

NASA is awarding approximately $500 million per mission for development. Each is expected to launch in the 2028-2030 timeframe.

 

The selected missions are:

 

DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging)

DAVINCI+ will measure the composition of Venus’ atmosphere to understand how it formed and evolved, as well as determine whether the planet ever had an ocean. The mission consists of a descent sphere that will plunge through the planet’s thick atmosphere, making precise measurements of noble gases and other elements to understand why Venus’ atmosphere is a runaway hothouse compared the Earth’s.

 

In addition, DAVINCI+ will return the first high resolution pictures of the unique geological features on Venus known as “tesserae,” which may be comparable to Earth’s continents, suggesting that Venus has plate tectonics. This would be the first U.S.-led mission to Venus’ atmosphere since 1978, and the results from DAVINCI+ could reshape our understanding of terrestrial planet formation in our solar system and beyond. James Garvin of Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator. Goddard provides project management.

 

VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy)

VERITAS will map Venus’ surface to determine the planet’s geologic history and understand why it developed so differently than Earth. Orbiting Venus with a synthetic aperture radar, VERITAS will chart surface elevations over nearly the entire planet to create 3D reconstructions of topography and confirm whether processes such as plate tectonics and volcanism are still active on Venus.

 

VERITAS also will map infrared emissions from Venus’ surface to map its rock type, which is largely unknown, and determine whether active volcanoes are releasing water vapor into the atmosphere. Suzanne Smrekar of NASA’s Jet Propulsion Laboratory in Southern California, is the principal investigator. JPL provides project management. The German Aerospace Center will provide the infrared mapper with the Italian Space Agency and France’s Centre National d'Etudes Spatiales contributing to the radar and other parts of the mission.

 

“We’re revving up our planetary science program with intense exploration of a world that NASA hasn’t visited in over 30 years,” said Thomas Zurbuchen, NASA’s associate administrator for science. “Using cutting-edge technologies that NASA has developed and refined over many years of missions and technology programs, we’re ushering in a new decade of Venus to understand how an Earth-like planet can become a hothouse. Our goals are profound. It is not just understanding the evolution of planets and habitability in our own solar system, but extending beyond these boundaries to exoplanets, an exciting and emerging area of research for NASA.”

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Physicists Measure Neutron Lifetime with Unprecedented Precision

Physicists Measure Neutron Lifetime with Unprecedented Precision | Amazing Science | Scoop.it

Physicists have performed an improved measurement of the free neutron lifetime using the UCNτ apparatus at the Los Alamos Neutron Science Center. Their results, published in the journal Physical Review Letters, represent a more than two-fold improvement over previous measurements.

 

Gonzalez et al. report an improved measurement of the free neutron lifetime. “This work sets a new gold-standard for a measurement that has fundamental importance to such questions as the relative abundances of the elements created in the early Universe,” said Dr. David Baxter, chair of the Department of Physics at Indiana University Bloomington.

“The process by which a neutron decays into a proton — with an emission of a light electron and an almost massless neutrino — is one of the most fascinating processes known to physicists,” added Dr. Daniel Salvat, also from the Department of Physics at Indiana University Bloomington.

“The effort to measure this value very precisely is significant because understanding the precise lifetime of the neutron can shed light on how the Universe developed — as well as allow physicists to discover flaws in our model of the subatomic Universe that we know exist but nobody has yet been able to find.”

The UCNτ experiment captures neutrons, whose temperatures are lowered to nearly absolute zero, inside a ‘bathtub’ lined with about 4,000 magnets. After waiting 30 to 90 min, the physicists count the surviving neutrons in the tub as they’re levitated against gravity by the force of the magnets.

The unique design of the UCNτ trap allows neutrons to remain stored for more than 11 days, a significantly longer time than earlier designs, minimizing the need for systematic corrections that could skew the results of the lifetime measurements. Over two years, the authors counted 38 million neutrons captured using this method. Their experiment gave a value for the free neutron lifetime of 877.75 seconds.

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Uncovering the secrets of ultra-low frequency gravitational waves

Uncovering the secrets of ultra-low frequency gravitational waves | Amazing Science | Scoop.it

New methods of detecting ultra-low frequency gravitational waves can be combined with other, less sensitive measurements to deliver fresh insights into the early development of our universe, according to researchers at the University of Birmingham. Gravitational waves -- ripples in the fabric of Einstein's spacetime -- that cross the universe at the speed of light have all sorts of wavelengths, or frequencies. Scientists have not yet managed to detect gravitational waves at extremely low 'nanohertz' frequencies, but new approaches currently being explored are expected to confirm the first low frequency signals quite soon.

 

The main method uses radio telescopes to detect gravitational waves using pulsars -- exotic, dead stars, that send out pulses of radio waves with extraordinary regularity. Researchers at the NANOGrav collaboration, for example, use pulsars to time to exquisite precision the rotation periods of a network, or array, of millisecond pulsars -- astronomers' best approximation of a network of perfect clocks -- spread throughout our galaxy. These can be used to measure the fractional changes caused by gravitational waves as they spread through the universe.

 

The question of what is producing these signals, however, has yet to be determined. Scientists in the University of Birmingham's Institute for Gravitational Wave Astronomy, argue that it will be extremely difficult to settle on an answer using only data from pulsar timing arrays (PTAs).

 

Instead, in a letter published today (18 October 2021) in Nature Astronomy, they suggest that combining this new data with observations made by other projects such as the European Space Agency's Gaia mission, will help the different signals still lingering from the earliest periods of our universe to be disentangled and interpreted.

The main theory for ultra-low frequency gravitational waves is that they are caused by a population of the supermassive black holes at the centre of merging galaxies. As galaxies merge, their central black holes pair up, forming binaries and generating gravitational waves. In this case, a detection of gravitational waves by PTA would offer exciting new ways to study the astrophysics of the assembly and growth of galaxies.

 

But there are other possibilities too. Nanohertz gravitational waves could tell the story of our infant universe, well before galaxies and black holes form. In fact, it has been suggested that extremely low frequency gravitational wave signals could instead be generated shortly after the big bang by other processes; for example if the Universe underwent what physicists refer to as a phase transition at the correct temperature.

 

Lead author, Dr Christopher Moore, said: "The first tentative hints of a gravitational wave signal using pulsar timing arrays might recently have been seen by NANOGrav and we expect the next few years to be a golden age for this type of science. The variety of explanations for these signals is exciting, but also a maze. We need a way to tell the different possible sources apart from each other. Currently, this is extremely difficult to do with pulsar timing array data alone."

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Neuroscientists roll out first comprehensive atlas of brain cells

Neuroscientists roll out first comprehensive atlas of brain cells | Amazing Science | Scoop.it

Researchers funded by the federal BRAIN Initiative have mapped all the cell types — more than a hundred — in the motor cortex of the brain.

 

The 17 studies, appearing online Oct. 6, 2021 in the journal Nature, are the result of five years of work by a huge consortium of researchers supported by the National Institutes of Health's Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative to identify the myriad of different cell types in one portion of the brain. It is the first step in a long-term project to generate an atlas of the entire brain to help understand how the neural networks in our head control our body and mind and how they are disrupted in cases of mental and physical problems.

 

"If you think of the brain as an extremely complex machine, how could we understand it without first breaking it down and knowing the parts?" asked cellular neuroscientist Helen Bateup, a University of California, Berkeley, associate professor of molecular and cell biology and co-author of the flagship paper that synthesizes the results of the other papers. "The first page of any manual of how the brain works should read: Here are all the cellular components, this is how many of them there are, here is where they are located and who they connect to."

 

Individual researchers have previously identified dozens of cell types based on their shape, size, electrical properties and which genes are expressed in them. The new studies identify about five times more cell types, though many are subtypes of well-known cell types. For example, cells that release specific neurotransmitters, like gamma-aminobutyric acid (GABA) or glutamate, each have more than a dozen subtypes distinguishable from one another by their gene expression and electrical firing patterns.

 

While the current papers address only the motor cortex, the BRAIN Initiative Cell Census Network (BICCN) -- created in 2017 -- endeavors to map all the different cell types throughout the brain, which consists of more than 160 billion individual cells, both neurons and support cells called glia. The BRAIN Initiative was launched in 2013 by then-President Barack Obama. "Once we have all those parts defined, we can then go up a level and start to understand how those parts work together, how they form a functional circuit, how that ultimately gives rise to perceptions and behavior and much more complex things," Bateup said.

 

Together with former UC Berkeley professor John Ngai, Bateup and UC Berkeley colleague Dirk Hockemeyer have already used CRISPR-Cas9 to create mice in which a specific cell type is labeled with a fluorescent marker, allowing them to track the connections these cells make throughout the brain. For the flagship journal paper, the Berkeley team created two strains of "knock-in" reporter mice that provided novel tools for illuminating the connections of the newly identified cell types, she said.

 

"One of our many limitations in developing effective therapies for human brain disorders is that we just don't know enough about which cells and connections are being affected by a particular disease and therefore can't pinpoint with precision what and where we need to target," said Ngai, who led UC Berkeley's Brain Initiative efforts before being tapped last year to direct the entire national initiative. "Detailed information about the types of cells that make up the brain and their properties will ultimately enable the development of new therapies for neurologic and neuropsychiatric diseases." Ngai is one of 13 corresponding authors of the flagship paper, which has more than 250 co-authors in all.

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Massive Tsunami From Dinosaur-Killing Chicxulub Asteroid Carved ‘Megaripples’ Into the Ocean Floor

Massive Tsunami From Dinosaur-Killing Chicxulub Asteroid Carved ‘Megaripples’ Into the Ocean Floor | Amazing Science | Scoop.it

The asteroid that killed off all non-avian dinosaurs made quite the splash when it hit the Yucatan Peninsula some 66 million years ago, generating a tsunami of epic proportions. Seafloor scars from this gigantic wave have been spotted in seismic data taken in Louisiana, offering new insights into this catastrophic event. Reaching over 50 feet tall, they're now the largest known ripples on Earth.

 

The megatsunami produced by the Chicxulub impact left a lasting mark on the seafloor, according to new research published in Earth and Planetary Science Letters and led by geophysicist Gary Kinsland from the University of Louisiana at Lafayette. The analysis suggests the wave caused the formation of “megaripples” along the bottom. These megaripples are now buried deep underground, but their existence is further confirmation of the power unleashed by the asteroid on that fateful Late Cretaceous day.

 

That the 6-mile-wide (10-kilometer) asteroid was able to carve the seafloor to such a degree is hardly a surprise. The kinetic energy generated by the impact was roughly 100 million megatons, which is akin to 10 billion Hiroshima-scale bombs going off at the same time. The collision triggered an impact winter that wiped out all non-avian dinosaurs and over 75% of all species on Earth. A simulation from 2018 found that the tsunami reached a maximum height of nearly 5,000 feet (1,500 meters).

 

The Chicxulub impact occurred in the shallow waters of the Yucatan Peninsula in what is now Mexico, resulting in a global-scale megatsunami (North and South America weren’t connected yet, so this big splash was literally felt around the world). Empirical evidence of the megatsunami is sorely lacking, but research presented in 2019 suggests debris—and even fish—from the impact site were blown thousands of miles away onto what is now southwestern North Dakota. Accordingly, the new paper describing the megaripples deepens our understanding of this cataclysmic event and further proves that a gigantic tsunami was generated by the asteroid impact.

 
 

The seismic data used in the study was provided by Devon Energy. The Oklahoma-based energy company wasn’t looking for evidence of the Chicxulub tsunami but rather evidence of oil and gas in central Louisiana. Seismic images are acquired by sending shockwaves into the ground, and the resulting reflections provide a picture of sediments and other features deep beneath the surface. This part of Louisiana was submerged during the Late Cretaceous owing to higher sea levels at the time, so Kinsland thought it might be a good idea to see if evidence of the megatsunami appeared in the seismic data provided by Devon Energy.

 

And indeed it was. The new paper documents a series of large-scale megaripples located nearly 5,000 feet (1,500 meters) beneath the surface. The studied layer dates back to the time of the impact, marking the “first time such buried, geologically old, tsunami megaripples have been imaged,” according to the study.

The ripples are separated by distances averaging nearly 2,000 feet (600 meters) and have an average height of 52.5 feet (16 meters), “making them the largest ripples documented on Earth,” as the scientists write in their study. Kinsland and his colleagues say the orientation of the megaripples are consistent with having originated at the site of the asteroid impact. These features formed at depths reaching around 200 feet (60 meters), as the gigantic waves from the tsunami surged northward.

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Expansion of wind and solar power implementations too slow to stop climate change

Expansion of wind and solar power implementations too slow to stop climate change | Amazing Science | Scoop.it

The production of renewable energy is increasing every year. But after analyzing the growth rates of wind and solar power in 60 countries, researchers at Chalmers University of Technology and Lund University in Sweden and Central European University in Vienna, Austria, conclude that virtually no country is moving sufficiently fast enough to avoid global warming of 1.5°C or even 2°C.

 

"This is the first time that the maximum growth rate in individual countries has been accurately measured, and it shows the enormous scale of the challenge of replacing traditional energy sources with renewables, as well as the need to explore diverse technologies and scenarios," says Jessica Jewell, Associate Professor of Energy Transitions at Chalmers University of Technology. The Intergovernmental Panel on Climate Change (IPCC) has identified energy scenarios compatible with keeping global warming under 1.5°C or 2°C. Most of these scenarios envision very rapid growth of renewable electricity: on average about 1.4 percent of total global electricity supply per year for both wind and solar power, and more than 3 percent in more ambitious solar power scenarios. But the researchers' new findings show that achieving such rapid growth has so far only been possible for a few countries.

 

Measuring and predicting the growth of new technologies like renewable energy is difficult, as they do not grow linearly. Instead, the growth usually follows a so-called S-curve—at first it accelerates exponentially, then stabilizes to linear growth for a while, and in the end slows down as the market becomes saturated. "We came up with a new method—to use mathematical models to measure the slope of the S-curve, that is, the maximum growth rate achieved at its steepest point. It is an entirely novel way to look at the growth of new technologies," says Jessica Jewell.

 

When analyzing the 60 largest countries, the researchers found that the maximum growth rate for onshore wind power is on average 0.8 percent of the total electricity supply per year, and 0.6 percent on average for solar—much lower than in the IPCC recommended scenarios. Sustained growth faster than 2 percent per year for wind and 1.5 percent for solar has only occurred in smaller countries such as Portugal, Ireland and Chile. "It is likely that faster growth is easier to achieve in smaller more homogenous countries, rather than in large diverse systems," says Jessica Jewell.

 

"Among larger countries, only Germany has so far been able to sustain growth of onshore wind power comparable with median climate stabilization scenarios. In other words, to stay on track for climate targets, the whole world should build wind power as fast as Germany built recently. That is highly unlikely to happen.

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Researchers observe translation symmetry breaking in twisted bilayer graphene

Researchers observe translation symmetry breaking in twisted bilayer graphene | Amazing Science | Scoop.it
Magic-angle twisted bilayer graphene is a material made of two sheets of graphene placed on top of each other, with one sheet twisted at precisely 1.05 degrees with respect to the other. This material has been found to be a very promising platform for studying different phases of matter, as it combines metallic, superconducting, magnetic and insulating phases in a single crystal.

 

Magic-angle twisted bilayer graphene is known to support flat energy bands with topological properties that can be accessed under specific conditions. Recent studies have found that strong interactions can isolate these topological bands, allowing the system to support so-called Chern insulator ground states. In Chern insulator ground states, the bulk of the material is insulating, yet electrons can propagate along the edges without dissipating heat.

 

Researchers at Harvard University, Massachusetts Institute of Technology (MIT) and National Institute for Materials Science in Japan have recently carried out a study aimed at investigating Chern insulator ground states in twisted bilayer graphene. Their paper, published in Nature Physics, provides evidence of the existence of a sequence of incompressible states with unpredicted Chern numbers in this fascinating material.

 

"While the Chern insulators reported to date follow a simple sequence corresponding to spin-valley symmetry breaking, our paper reports numerous new Chern insulators in which electron-electron interactions break the translation symmetry of the lattice," Andrew Pierce, one of the researchers who carried out the study, told Phys.org.

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Two-dimensional supersolid quantum gas produced in the laboratory for the first time

Two-dimensional supersolid quantum gas produced in the laboratory for the first time | Amazing Science | Scoop.it
Quantum matter can be solid and fluid at the same time—a situation known as supersolidity. Researchers led by Francesca Ferlaino have now created for the first time this fascinating property along two dimensions. They now report in the journal Nature on the realization of supersolidity along two axes of an ultracold quantum gas. The experiment offers many possibilities for further investigation of this exotic state of matter.

 

Quantum gases are very well suited for investigating the microscopic consequences of interactions in matter. Today, scientists can precisely control individual particles in extremely cooled gas clouds in the laboratory, revealing phenomena that cannot be observed in the every-day world. For example, the individual atoms in a Bose-Einstein condensate are completely delocalized. This means that the same atom exists at each point within the condensate at any given time.

 

Two years ago, the research group led by Francesca Ferlaino from the Department of Experimental Physics at the University of Innsbruck and the Institute of Quantum Optics and Quantum Information at the Austrian Academy of Sciences in Innsbruck managed for the first time to generate supersolid states in ultracold quantum gases of magnetic atoms. The magnetic interaction causes the atoms to self-organize into droplets and arrange themselves in a regular pattern.

 

"Normally, you would think that each atom would be found in a specific droplet, with no way to get between them," says Matthew Norcia of Francesca Ferlaino's team. "However, in the supersolid state, each particle is delocalized across all the droplets, existing simultaneously in each droplet. So basically, you have a system with a series of high-density regions (the droplets) that all share the same delocalized atoms." This bizarre formation enables effects such as frictionless flow despite the presence of spatial order (superfluidity).

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Global warming associated heatwaves could have severe negative impacts on global marine wild life and fish stocks

Global warming associated heatwaves could have severe negative impacts on global marine wild life and fish stocks | Amazing Science | Scoop.it
Extremely hot years will wipe out hundreds of thousands of tonnes of fish available for catch in a country's waters in this century, on top of projected decreases to fish stocks from long-term climate change, a new UBC study projects.

 

Researchers from the UBC Institute for the Oceans and Fisheries (IOF) used a complex model incorporating extreme annual ocean temperatures in Exclusive Economic Zones, where the majority of global fish catches occur, into climate-related projections for fish, fisheries and their dependent human communities.

 

Modeling a worst-case scenario where no action is taken to mitigate greenhouse gas emissions they projected a six percent drop in the amount of potential catches per year and 77 percent of exploited species are projected to decrease in biomass, or the amount of fish by weight in a given area, due to extremely hot years. These decreases are on top of those projected due to long-term decadal-scale climate change.

 

  • In Pacific Canada, Sockeye salmon catches are projected to decrease by 26 percent on average during a high temperature event between 2000 and 2050, an annual loss of 260 to 520 tons of fish. With losses due to climate change, when a temperature extreme occurs in the 2050s, the total decrease in annual catch would be more than 50 percent or 530 to 1060 tons of fish.
  • Peruvian anchoveta catches are projected to decline by 34 percent during an extreme high temperature event between 2000 and 2050, or more than 900,000 tons per year. With climate change, a temperature extreme is projected to cost Peruvian anchoveta fisheries more than 1.5 million tons of their potential catch.
  • Overall, a high temperature extreme event is projected to cause a 25 percent drop in annual revenue for Peruvian anchoveta fisheries, or a loss of around US$600 million
  • Nearly three million jobs in the Indonesian fisheries-related sector are projected to be lost when a high temperature extreme occurs in their waters between 2000 and 2050.
  • Some stocks are projected to increase due to these extreme events, and climate change, but not enough to mitigate the losses
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Cracking open strong field quantum electrodynamics with the world's most powerful lasers

Cracking open strong field quantum electrodynamics with the world's most powerful lasers | Amazing Science | Scoop.it

Lasers probe some of nature's most jealously guarded secrets. A newly published theoretical and computer modeling study suggests that the world's most powerful lasers might finally crack the elusive physics behind some of the most extreme phenomena in the universe—gamma ray bursts, pulsar magnetospheres, and more.

The international research team behind the study includes researchers from Lawrence Berkeley National Laboratory (Berkeley Lab) and France's Alternative Energies and Atomic Energy Commission (CEA-LIDYL). They report their findings in the prestigious journal Physical Review Letters.

The research team was led by CEA's Henri Vincenti, who proposed the main physical concept. Jean-Luc Vay and Andrew Myers, of Berkeley Lab's Accelerator Technology and Applied Physics (ATAP) Division and Computational Research Division, respectively, led development of the simulation code used for the research. (Vincenti previously worked at Berkeley Lab as a Marie Curie Research Fellow and remains an ATAP affiliate and frequent collaborator.) The theoretical and numerical work was led by Luca Fedeli from Vincenti's team at CEA.

The team's modeling study shows that petawatt (PW)-class lasers—juiced to even higher intensities via light-matter interactions—might provide a key to unlock the mysteries of the strong-field (SF) regime of quantum electrodynamics (QED). A petawatt is 1 times ten to the fifteenth power (that is, followed by 15 zeroes), or a quadrillion watts. The output of today's most powerful lasers is measured in petawatts.

"This is a powerful demonstration of how advanced simulation of complex systems can enable new paths for discovery science by integrating multiple physics processes—in this case, the laser interaction with a target and subsequent production of particles in a second target," said ATAP Division Director Cameron Geddes.

While QED is a cornerstone of modern physics that has withstood the rigor of experiment over many decades, probing SF-QED requires electromagnetic fields of an intensity many orders of magnitude beyond those normally available on Earth.

Researchers have tried side routes to SF-QED, such as using powerful particle beams from accelerators to observe particle interactions with the strong fields that are naturally present in some aligned crystals.

For a more direct approach, the highest electromagnetic fields available in a laboratory are delivered by PW-class lasers. A 10-PW laser (the world's most powerful at this time), focused down to a few microns, can reach intensities close to 1023 watts per square centimeter. The associated electric field values can be as high as 1014 volts per meter. Yet studying SF-QED requires even higher field amplitudes than that—orders of magnitude beyond what can be achieved with those lasers.

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Deep Learning in the Cosmos: Machine Learning (ML) Applications for Astronomy and Cosmology

Deep Learning in the Cosmos: Machine Learning (ML) Applications for Astronomy and Cosmology | Amazing Science | Scoop.it

Deep learning has helped advance the state-of-the-art in multiple fields over the last decade, with scientific research as no exception.

 

The Kepler instrument is a space-based telescope designed to study and planets outside our solar system, aka exoplanets. The first exoplanet orbiting a star like our own was described by Didier Queloz and Michel Mayor in 1995, landing the pair the 2019 Nobel Prize in Physics. More than a decade later when Kepler was launched in 2009, the total number of known exoplanets was less than 400. The now-dormant telescope began operation in 2009, discovering more than 1,000 new exoplanets before a reaction wheel, a component used for precision pointing, failed in 2013.

 

This brought the primary phase of the mission to an end.

Some clever engineering changes allowed the telescope to begin a second period of data acquisition, termed K2. The data from K2 were noisier and limited to 80 days of continuous observation or less. These limitations pose challenges in identifying promising planetary candidates among the thousands of putative planetary signals, a task that had been previously handled nicely by a convolutional neural network (AstroNet) working with the data from Kepler’s primary data collection phase. Researchers at the University of Texas, Austin decided to try the same approach and derived AstroNet-K2 from the architecture of AstroNet to sort K2 planetary signals.

 

After training, AstroNet-K2 had a 98% accuracy rate in identifying confirmed exoplanets in the test set, with low false positives. The authors deemed this performance to be sufficient for use as an analysis tool rather than full automation, requiring human follow-up.

 

From the paper:

While the performance of our network is not quite at the level
required to generate fully automatic and uniform
planet candidate catalogs, it serves as a proof of
concept. — 
(Dattilo et al. 2019)

AstroNet-K2 receives this blog post’s coveted “Best Value” award for achieving a significant scientific bang-for-your-buck. Unlike the other two projects on this list that are more conceptual demonstrations, this project resulted in actual scientific progress, adding two new confirmed entries to the catalog of known exoplanets: EPIC 246151543 b and EPIC 246078672 b.

 

In addition to the intrinsic challenges of the K2 data, the signals for the planets were further confounded by Mars transiting the observiation window and by 5 days of missing data associated with a safe mode event. This is a pretty good example of effective machine learning in action: the authors took an existing conv-net with a proven track record and modified it to perform well on the given data, adding a couple new discoveries from a difficult observation run without re-inventing the wheel.

 

Worth noting is that the study’s lead author, Anne Dattilo, was an undergraduate at the time the work was completed. That’s a pretty good outcome for an undergraduate research project. The use of open-source software and building on previously developed architectures underlines the fact that deep learning is in a advanced readiness phase. The technology is not fully mature to the point of ubiquity, but the tools are all there on the shelf ready to be applied.

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Scientists predict that CoVid is here to stay — at least for a generation

Scientists predict that CoVid is here to stay — at least for a generation | Amazing Science | Scoop.it
A Nature survey shows many scientists expect the virus that causes COVID-19 to become endemic, but it could pose less danger over time.

 

Nature asked more than 100 immunologists, infectious-disease researchers and virologists working on the coronavirus whether it could be eradicated. Almost 90% of respondents think that the coronavirus will become endemic — meaning that it will continue to circulate in pockets of the global population for years to come (see 'Endemic future').

 

“Eradicating this virus right now from the world is a lot like trying to plan the construction of a stepping-stone pathway to the Moon. It’s unrealistic,” says Michael Osterholm, an epidemiologist at the University of Minnesota in Minneapolis. But failure to eradicate the virus does not mean that death, illness or social isolation will continue on the scales seen so far. The future will depend heavily on the type of immunity people acquire through infection or vaccination and how the virus evolves. Influenza and the four human coronaviruses that cause common colds are also endemic: but a combination of annual vaccines and acquired immunity means that societies tolerate the seasonal deaths and illnesses they bring without requiring lockdowns, masks and social distancing.

 

More than one-third of the respondents to Nature’s survey thought that it would be possible to eliminate SARS-CoV-2 from some regions while it continued to circulate in others. In zero-COVID regions there would be a continual risk of disease outbreaks, but they could be quenched quickly by herd immunity if most people had been vaccinated. “I guess COVID will be eliminated from some countries, but with a continuing (and maybe seasonal) risk of reintroduction from places where vaccine coverage and public-health measures have not been good enough,” says Christopher Dye, an epidemiologist at the University of Oxford, UK.

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Global warming effects: Newsom declares renewed statewide drought emergency

Global warming effects: Newsom declares renewed statewide drought emergency | Amazing Science | Scoop.it

Gov. of California Gavin Newsom today declared a drought emergency for the entire state of California, as conservation efforts continue to fall far short of state targets. Newsom also authorized California’s water regulators to ban wasteful water use, such as spraying down public sidewalks, and directed his Office of Emergency Services to fund drinking water as needed. But he stopped short of issuing any statewide conservation mandates. 

 

“As the western U.S. faces a potential third year of drought, it’s critical that Californians across the state redouble our efforts to save water in every way possible,” Newsom said in a statement. 

Today’s announcement extends drought emergencies, already declared in 50 counties, to the eight remaining counties where conditions had thus far not been deemed severe enough: Los Angeles, Orange, Riverside, San Bernardino, San Diego, Imperial, San Francisco and Ventura. 

 

The emergency declarations are aimed at easing responses to the deepening drought — such as emergency bottled water purchases or construction to bolster water supplies — by reducing environmental and other regulations. Under the proclamation, local water suppliers must begin preparing for the possibility of a dry year ahead.  

 

“We think we’ll be able to manage through this year,” said David Pettijohn, director of water resources at the Los Angeles Department of Water and Power. “Next year is the issue. And we don’t know what the water year is going to look like. Nobody can predict the weather.”

 

But California’s water watchers say that without a conservation mandate, California is losing time, and water. “We know mandates are more effective than voluntary calls,” said Heather Cooley, director of research at the Pacific Institute, a global water think tank. “It takes time to ramp up, and because of the delay in asking Californians to save water this spring, we are further behind than we should be.” 

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Natural Infection Versus Vaccination: Differences in COVID Antibody Responses Emerge

Natural Infection Versus Vaccination: Differences in COVID Antibody Responses Emerge | Amazing Science | Scoop.it

Hope for a future without fear of COVID-19 comes down to circulating antibodies and memory B cells. Unlike circulating antibodies, which peak soon after vaccination or infection only to fade a few months later, memory B cells can stick around to prevent severe disease for decades. And they evolve over time, learning to produce successively more potent "memory antibodies" that are better at neutralizing the virus and more capable of adapting to variants. Vaccination produces greater amounts of circulating antibodies than natural infection. But a new study suggests that not all memory B cells are created equal. While vaccination gives rise to memory B cells that evolve over a few weeks, natural infection births memory B cells that continue to evolve over several months, producing highly potent antibodies adept at eliminating even viral variants.  The findings highlight an advantage bestowed by natural infection rather than vaccination, but the authors caution that the benefits of stronger memory B cells do not outweigh the risk of disability and death from COVID-19. "While a natural infection may induce maturation of antibodies with broader activity than a vaccine does—a natural infection can also kill you," says Michel C. Nussenzweig, the Zanvil A. Cohn and Ralph M. Steinman professor and head of Rockefeller's Laboratory of Molecular Immunology. "A vaccine won't do that and, in fact, protects against the risk of serious illness or death from infection."

 

Your body on COVID-19

When any virus enters the body, immune cells immediately churn out hordes of circulating antibodies. Foot soldiers of the immune system, these antibodies burn bright but decay at variable rates depending on the vaccine or infection—they may protect us for months or years but then dwindle in number, allowing possible reinfection. The immune system has a backup plan: an elite cadre of memory B cells that outlive circulating antibodies to produce so-called memory antibodies that provide long-term protection. Studies suggest that memory B cells for smallpox last at least 60 years after vaccination; those for Spanish flu, nearly a century. And while memory B cells don't necessarily block reinfection, they can prevent severe disease. Recent studies have suggested that within five months of receiving a vaccine or recovering from a natural infection, some of us no longer retain sufficient circulating antibodies to keep the novel coronavirus at bay, but our memory B cells stand vigilant. Until now, however, scientists did not know whether the vaccines could be expected to provide the sort of robust memory B cell response seen after natural infection.

 

The convalescent advantage

Nussenzweig and colleagues resolved to tease out any differences in memory B cell evolution by comparing blood samples from convalescent COVID-19 patients to those from mRNA-vaccinated individuals who had never suffered natural infection. Vaccination and natural infection elicited similar numbers of memory B cells. Memory B cells rapidly evolved between the first and second dose of the Pfizer and Moderna vaccines, producing increasingly potent memory antibodies. But after two months, progress stalled. The memory B cells were present in large numbers and expressed potent antibodies, but the antibodies were not getting any stronger. Also, although some of these antibodies were able to neutralize Delta and other variants, there was no overall improvement in breadth. With convalescent patients, on the other hand, memory B cells continued to evolve and improve up to one year after infection. More potent and more broadly neutralizing memory antibodies were coming out with every memory B cell update.

 

To boost or not to boost

There are several potential reasons that memory B cells produced by natural infection might be expected to outperform those produced by mRNA vaccines, the researchers say. It is possible that the body responds differently to viruses that enter through the respiratory tract than those that are injected into our upper arms. Or perhaps an intact virus goads the immune system in a way that the lone spike protein represented by the vaccines simply cannot. Then again, maybe it's that the virus persists in the naturally infected for weeks, giving the body more time to mount a robust response. The vaccine, on the other hand, is flushed out of the body mere days after triggering the desired immune response. Regardless of the cause, the implications are clear. We can expect memory B cells to undergo limited volleys of evolution in response to mRNA vaccines, a finding that may have significant implications for the design and rollout of booster shots. A booster with the currently available mRNA vaccine would be expected to engage memory cells to produce circulating antibodies that are strongly protective against the original virus and somewhat less so against the variants, Nussenzweig says. "When to administer the booster depends on the object of boosting," he says. "If the goal is to prevent infection, then boosting will need to be done after 6 to 18 months depending on the immune status of the individual. If the goal is to prevent serious disease boosting may not be necessary for years."

 

See findings published in Nature (October 7, 2021):

https://doi.org/10.1038/s41586-021-04060-7


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Experiments reveal formation of a new state of matter

Experiments reveal formation of a new state of matter | Amazing Science | Scoop.it

The central principle of superconductivity is that electrons form pairs. But can they also condense into foursomes? Recent findings have suggested they can, and a physicist at KTH Royal Institute of Technology today published the first experimental evidence of this quadrupling effect and the mechanism by which this state of matter occurs.

Reporting today in Nature Physics, Professor Egor Babaev and collaborators presented evidence of fermion quadrupling in a series of experimental measurements on the iron-based material, Ba1−xKxFe2As2. The results follow nearly 20 years after Babaev first predicted this kind of phenomenon, and eight years after he published a paper predicting that it could occur in the material.  

The pairing of electrons enables the quantum state of superconductivity, a zero-resistance state of conductivity which is used in MRI scanners and quantum computing. It occurs within a material as a result of two electrons bonding rather than repelling each other, as they would in a vacuum. The phenomenon was first described in a theory by, Leon Cooper, John Bardeen and John Schrieffer, whose work was awarded the Nobel Prize in 1972.

So-called Cooper pairs are basically “opposites that attract”. Normally two electrons, which are negatively-charged subatomic particles, would strongly repel each other. But at low temperatures in a crystal they become loosely bound in pairs, giving rise to a robust long-range order. Currents of electron pairs no longer scatter from defects and obstacles and a conductor can lose all electrical resistance, becoming a new state of matter: a superconductor. 

Only in recent years has the theoretical idea of four-fermion condensates become broadly accepted. 

For a fermion quadrupling state to occur there has to be something that prevents condensation of pairs and prevents their flow without resistance, while allowing condensation of four-electron composites, Babaev says.

The Bardeen-Cooper-Schrieffer theory didn’t allow for such behavior, so when Babaev’s experimental collaborator at Technische Universtät Dresden, Vadim Grinenko, found in 2018 the first signs of a fermion quadrupling condensate, it challenged years of prevalent scientific agreement.

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XENON1T: Have we detected already detected dark energy? Cambridge scientists say it’s a possibility

XENON1T: Have we detected already detected dark energy? Cambridge scientists say it’s a possibility | Amazing Science | Scoop.it

Dark energy, the mysterious force that causes the universe to accelerate, may have been responsible for unexpected results from the XENON1T experiment, deep below Italy's Apennine Mountains.

 

A new study, led by researchers at the University of Cambridge and reported in the journal Physical Review D, suggests that some unexplained results from the XENON1T experiment in Italy may have been caused by dark energy, and not the dark matter the experiment was designed to detect. They constructed a physical model to help explain the results, which may have originated from dark energy particles produced in a region of the Sun with strong magnetic fields, although future experiments will be required to confirm this explanation. The researchers say their study could be an important step toward the direct detection of dark energy.

 

Everything our eyes can see in the skies and in our everyday world -- from tiny moons to massive galaxies, from ants to blue whales -- makes up less than five percent of the universe. The rest is dark. About 27% is dark matter -- the invisible force holding galaxies and the cosmic web together -- while 68% is dark energy, which causes the universe to expand at an accelerated rate. "Despite both components being invisible, we know a lot more about dark matter, since its existence was suggested as early as the 1920s, while dark energy wasn't discovered until 1998," said Dr Sunny Vagnozzi from Cambridge's Kavli Institute for Cosmology, the paper's first author. "Large-scale experiments like XENON1T have been designed to directly detect dark matter, by searching for signs of dark matter 'hitting' ordinary matter, but dark energy is even more elusive."

 

To detect dark energy, scientists generally look for gravitational interactions: the way gravity pulls objects around. And on the largest scales, the gravitational effect of dark energy is repulsive, pulling things away from each other and making the Universe's expansion accelerate. About a year ago, the XENON1T experiment reported an unexpected signal, or excess, over the expected background. "These sorts of excesses are often flukes, but once in a while they can also lead to fundamental discoveries," said Dr Luca Visinelli, a researcher at Frascati National Laboratories in Italy, a co-author of the study. "We explored a model in which this signal could be attributable to dark energy, rather than the dark matter the experiment was originally devised to detect."

 

At the time, the most popular explanation for the excess were axions -- hypothetical, extremely light particles -- produced in the Sun. However, this explanation does not stand up to observations, since the amount of axions that would be required to explain the XENON1T signal would drastically alter the evolution of stars much heavier than the Sun, in conflict with what we observe.

We are far from fully understanding what dark energy is, but most physical models for dark energy would lead to the existence of a so-called fifth force. There are four fundamental forces in the universe, and anything that can't be explained by one of these forces is sometimes referred to as the result of an unknown fifth force.

 

However, we know that Einstein's theory of gravity works extremely well in the local universe. Therefore, any fifth force associated to dark energy is unwanted and must be 'hidden' or 'screened' when it comes to small scales, and can only operate on the largest scales where Einstein's theory of gravity fails to explain the acceleration of the Universe. To hide the fifth force, many models for dark energy are equipped with so-called screening mechanisms, which dynamically hide the fifth force.

 

Vagnozzi and his co-authors constructed a physical model, which used a type of screening mechanism known as chameleon screening, to show that dark energy particles produced in the Sun's strong magnetic fields could explain the XENON1T excess. "Our chameleon screening shuts down the production of dark energy particles in very dense objects, avoiding the problems faced by solar axions," said Vagnozzi. "It also allows us to decouple what happens in the local very dense Universe from what happens on the largest scales, where the density is extremely low."

 

The researchers used their model to show what would happen in the detector if the dark energy was produced in a particular region of the Sun, called the tachocline, where the magnetic fields are particularly strong. "It was really surprising that this excess could in principle have been caused by dark energy rather than dark matter," said Vagnozzi. "When things click together like that, it's really special."

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Researchers successfully build four-legged sw

Researchers successfully build four-legged sw | Amazing Science | Scoop.it

As a robotics engineer, Yasemin Ozkan-Aydin, assistant professor of electrical engineering at the University of Notre Dame, gets her inspiration from biological systems. The collective behaviors of ants, honeybees and birds to solve problems and overcome obstacles is something researchers have developed in aerial and underwater robotics. Developing small-scale swarm robots with the capability to traverse complex terrain, however, comes with a unique set of challenges.

 

In research published in Science Robotics, Ozkan-Aydin presents how she was able to build multi-legged robots capable of maneuvering in challenging environments and accomplishing difficult tasks collectively, mimicking their natural-world counterparts. “Legged robots can navigate challenging environments such as rough terrain and tight spaces, and the use of limbs offers effective body support, enables rapid maneuverability and facilitates obstacle crossing,” Ozkan-Aydin said. “However, legged robots face unique mobility challenges in terrestrial environments, which results in reduced locomotor performance.”

 

For the study, Ozkan-Aydin said, she hypothesized that a physical connection between individual robots could enhance the mobility of a terrestrial legged collective system. Individual robots performed simple or small tasks such as moving over a smooth surface or carrying a light object, but if the task was beyond the capability of the single unit, the robots physically connected to each other to form a larger multi-legged system and collectively overcome issues.

 

“When ants collect or transport objects, if one comes upon an obstacle, the group works collectively to overcome that obstacle. If there’s a gap in the path, for example, they will form a bridge so the other ants can travel across — and that is the inspiration for this study,” she said. “Through robotics we’re able to gain a better understanding of the dynamics and collective behaviors of these biological systems and explore how we might be able to use this kind of technology in the future.”

 

Using a 3D printer, Ozkan-Aydin built four-legged robots measuring 15 to 20 centimeters, or roughly 6 to 8 inches, in length. Each was equipped with a lithium polymer battery, microcontroller and three sensors — a light sensor at the front and two magnetic touch sensors at the front and back, allowing the robots to connect to one another. Four flexible legs reduced the need for additional sensors and parts and gave the robots a level of mechanical intelligence, which helped when interacting with rough or uneven terrain.

 

“You don’t need additional sensors to detect obstacles because the flexibility in the legs helps the robot to move right past them,” said Ozkan-Aydin. “They can test for gaps in a path, building a bridge with their bodies; move objects individually; or connect to move objects collectively in different types of environments, not dissimilar to ants.”

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No Longer Science Fiction: Photosynthesizing Algae Can Produce Oxygen in Brain Blood Vessels of Tadpoles

No Longer Science Fiction: Photosynthesizing Algae Can Produce Oxygen in Brain Blood Vessels of Tadpoles | Amazing Science | Scoop.it

Leading a double life in water and on land, frogs have many breathing techniques – through the gills, lungs, and skin – over the course of their lifetime. Now German scientists have developed another method that allows tadpoles to “breathe” by introducing algae into their bloodstream to supply oxygen. The method developed, presented October 13 in the journal iScience, provided enough oxygen to effectively rescue neurons in the brains of oxygen-deprived tadpoles.

“The algae actually produced so much oxygen that they could bring the nerve cells back to life, if you will,” says senior author Hans Straka of Ludwig-Maximilians-University Munich. “For many people, it sounds like science fiction, but after all, it’s just the right combination of biological schemes and biological principles.”

Straka was studying oxygen consumption in tadpole brains of African clawed frogs (Xenopus laevis) when a lunch conversation with a botanist sparked an idea to combine plant physiology with neuroscience: harnessing the power of photosynthesis to supply nerve cells with oxygen. The idea didn’t seem far-fetched. In nature, algae live harmoniously in sponges, corals, and anemones, providing them with oxygen and even nutrients. Why not in vertebrates like frogs? To explore the possibility, the team injected green algae (Chlamydomonas renhardtii) or cyanobacteria (Synechocystis) into tadpoles’ hearts. With each heartbeat, the algae inched through blood vessels and eventually reached the brain, turning the translucent tadpole bright green. Shining light on these tadpoles prompted both algae species to pump out oxygen to nearby cells.

After distributing algae to the brain, the researchers isolated the tadpole’s head and placed it in an oxygen bubble bath with essential nutrients that would preserve the functioning of the cells, allowing the team to monitor neural activity and oxygen levels. As the researchers depleted oxygen from the bath, the nerves ceased firing and fell silent. However, illuminating the tadpole head restarted the neural activity within 15 to 20 minutes, which is about two times faster than replenishing the bath with oxygen without the algae. The revived nerves also performed as well or even better than before oxygen depletion, showing that the researchers’ method was quick and efficient.

“We succeeded in showing the proof of principle experiment with this method. It was amazingly reliable and robust, and in my eyes, a beautiful approach,” says Straka. “Working in principle doesn’t really mean that you could apply it at the end, but it’s the first step in order to initiate other studies.”

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Breakthrough proof-of-concept clears the path for sophisticated quantum AI

Breakthrough proof-of-concept clears the path for sophisticated quantum AI | Amazing Science | Scoop.it

Convolutional neural networks running on quantum computers have generated significant buzz for their potential to analyze quantum data better than classical computers can. While a fundamental solvability problem known as "barren plateaus" has limited the application of these neural networks for large data sets, new research overcomes that Achilles heel with a rigorous proof that guarantees scalability.

"The way you construct a quantum neural network can lead to a barren plateau—or not," said Marco Cerezo, co-author of the paper titled "Absence of Barren Plateaus in Quantum Convolutional Neural Networks," published today by a Los Alamos National Laboratory team in Physical Review X.

 

Cerezo is a physicist specializing in quantum computingquantum machine learning, and quantum information at Los Alamos. "We proved the absence of barren plateaus for a special type of quantum neural network. Our work provides trainability guarantees for this architecture, meaning that one can generically train its parameters." As an artificial intelligence (AI) methodology, quantum convolutional neural networks are inspired by the visual cortex. As such, they involve a series of convolutional layers, or filters, interleaved with pooling layers that reduce the dimension of the data while keeping important features of a data set. These neural networks can be used to solve a range of problems, from image recognition to materials discovery. Overcoming barren plateaus is key to extracting the full potential of quantum computers in AI applications and demonstrating their superiority over classical computers.

 

Until now, Cerezo said, researchers in quantum machine learning analyzed how to mitigate the effects of barren plateaus, but they lacked a theoretical basis for avoiding it altogether. The Los Alamos work shows how some quantum neural networks are, in fact, immune to barren plateaus. "With this guarantee in hand, researchers will now be able to sift through quantum-computer data about quantum systems and use that information for studying material properties or discovering new materials, among other applications," said Patrick Coles, a quantum physicist at Los Alamos and a coauthor of the paper.

 

Many more applications for quantum AI algorithms will emerge, Coles thinks, as researchers use near-term quantum computers more frequently and generate more and more data—all machine learning programs are data-hungry.

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Researchers announce photon-phonon breakthrough

Researchers announce photon-phonon breakthrough | Amazing Science | Scoop.it
New research by a City College of New York team has uncovered a novel way to combine two different states of matter. For one of the first times, topological photons—light—has been combined with lattice vibrations, also known as phonons, to manipulate their propagation in a robust and controllable way. 

 

The study utilized topological photonics, an emergent direction in photonics which leverages fundamental ideas of the mathematical field of topology about conserved quantities—topological invariants—that remain constant when altering parts of a geometric object under continuous deformations. One of the simplest examples of such invariants is number of holes, which, for instance, makes donut and mug equivalent from the topological point of view.

 

The topological properties endow photons with helicity, when photons spin as they propagate, leading to unique and unexpected characteristics, such as robustness to defects and unidirectional propagation along interfaces between topologically distinct materials. Thanks to interactions with vibrations in crystals, these helical photons can then be used to channel infrared light along with vibrations. 

 

The implications of this work are broad, in particular allowing researchers to advance Raman spectroscopy, which is used to determine vibrational modes of molecules. The research also holds promise for vibrational spectroscopy—also known as infrared spectroscopy—which measures the interaction of infrared radiation with matter through absorption, emission, or reflection. This can then be utilized to study and identify and characterize chemical substances.

 

"We coupled helical photons with lattice vibrations in hexagonal boron nitride, creating a new hybrid matter referred to as phonon-polaritons," said Alexander Khanikaev, lead author and physicist with affiliation in CCNY's Grove School of Engineering. "It is half light and half vibrations. Since infrared light and lattice vibrations are associated with heat, we created new channels for propagation of light and heat together. Typically, lattice vibrations are very hard to control, and guiding them around defects and sharp corners was impossible before."

 

The new methodology can also implement directional radiative heat transfer, a form of energy transfer during which heat is dissipated through electromagnetic waves. 

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Novel approach using AI to study with unprecedented resolution the phase behaviors of superionic water found on ice giants

Novel approach using AI to study with unprecedented resolution the phase behaviors of superionic water found on ice giants | Amazing Science | Scoop.it

LLNL scientists have developed a new approach using machine learning to study with unprecedented resolution the phase behaviors of superionic water found in ice giants.

 

The interiors of Uranus and Neptune each contain about 50,000 times the amount of water in Earth’s oceans, and a form of water known as superionic water is believed to be stable at depths greater than approximately one-third of the radius of these ice giants.

 

Superionic water is a phase of H2O where hydrogen atoms become liquid-like while oxygen atoms remain solid-like on a crystalline lattice. Although superionic water was proposed over three decades ago, its optical properties and oxygen lattices were only accurately measured recently in experiments by LLNL’s Marius Millot and Federica Coppari, and many properties of this hot “black ice” are still uncharted.

 

Buried deep within the core of planets, much of the water in the universe may be superionic. Understanding its thermodynamic and transport properties is crucial for planetary science but difficult to probe experimentally or theoretically. Under the pressures and temperatures found in ice-giant planets, most of this water was predicted by First-Principles Molecular Dynamics (FPMD) simulations to be in a superionic phase. However, such quantum-mechanical simulations have traditionally been limited to short simulation times (10s of picoseconds) and small system size (100s of atoms), leading to significant uncertainty in the location of phase boundaries such as the melting line.  

 

In experiments on superionic water, sample preparation is extremely challenging: hydrogen positions cannot be determined and temperature measurements in dynamical compression experiments are not straightforward. Often the experiments benefit from the guidance provided by quantum molecular dynamic simulations both during the design stage and for the interpretation of the results. 

 

In the most recent research, the team made a leap forward in its ability to treat large system sizes and long-time scales by making use of machine learning techniques to learn the atomic interactions from quantum mechanical calculations. They then used that machine-learned potential to drive the molecular dynamics and enable the use of advanced free energy sampling methods to accurately determine the phase boundaries.

“We use machine learning and free energy methods to overcome the limitations of quantum mechanical simulations, and characterize hydrogen diffusion, superionic transitions, and phase behaviors of water at extreme conditions,” said LLNL physicist Sebastien Hamel, a co-author of a paper appearing in Nature Physics.

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New Covid-19 Drug Might Cut Chance of Hospitalizations and Deaths by Half

New Covid-19 Drug Might Cut Chance of Hospitalizations and Deaths by Half | Amazing Science | Scoop.it
If authorized, the drug could be the first specialized oral drug that can prevent the worst of covid-19.

 

A pill that can effectively prevent the worst outcomes of covid-19 may finally be on the way. Just recently, pharmaceutical companies Merck and Ridgeback Biotherapeutics (FL) announced the preliminary results of a large trial testing out their experimental antiviral drug, called molnupiravir. The drug reportedly reduced the odds of later hospitalization or death by about 50% in high-risk individuals with mild to moderate illness—results so dramatically positive that the trial was stopped early. The companies now plan to seek an emergency use authorization for the drug, though the findings have yet to be vetted by outside scientists.

 

Molnupiravir is said to work by interfering with a virus’s ability to replicate inside a host’s cells, hopefully limiting viral load and enabling the immune system to clear the infection faster, without progressing to more severe illness. The drug had been in development prior to the pandemic as a potential treatment for the flu and other viral diseases. The Phase 3 randomized, double-blinded, and controlled trial of molnupiravir, called MOVe-OUT, was intended to involve around 1,500 unvaccinated patients who initially had mild to moderate covid-19 symptoms but were at higher risk of severe illness due to their preexisting health. As is commonplace, though, researchers conducted an interim analysis of the trial when only 775 patients had been treated. About 14% of those on placebo went on to become hospitalized or die within 30 days, compared to around 7% of those who took molnupiravir, No deaths at all were reported in the treatment group, compared to eight who died in the placebo group.

 

Clinical trials can be stopped early by an independent board of outside scientists because the treatment looks so unlikely to work that it would be unethical to continue. But they can also be stopped because the treatment appears so much better than standard care that it wouldn’t be right to keep enrolling participants to a control or placebo group. And that’s what the independent board agreed was the case here. The companies say that more than 90% of the trial had already been recruited by the time it was formally ended, though, so there will likely be more data to sift through.

 
 

“With the virus continuing to circulate widely, and because therapeutic options currently available are infused and/or require access to a healthcare facility, antiviral treatments that can be taken at home to keep people with COVID-19 out of the hospital are critically needed,” said Wendy Holman, CEO of Ridgeback Biotherapeutics, in a statement announcing the results.

 

Though molnupiravir has shown promise as a covid-19 treatment for some time now, there has been some controversy and failure surrounding it as well. Last year, federal official and eventual whistleblower Rick Bright alleged that the Trump administration retaliated against him for several decisions, including the reluctance by him and others to issue additional funding to the original founders of the drug at Emory University and later Ridgeback for their development of the drug, prior to and during the pandemic. Bright argued that the drug, while promising, was already getting enough resources, and he expressed concern that extra funding would subvert the normal process of research and development. He also noted that some animal studies had suggested that similar drugs could cause harmful mutations that could be passed onto to children.

 

In April 2021, Merck and Ridgeback Biotherapeutics also stopped one part of their MOVe-OUT trial, after it was determined that not enough evidence supported the use of molnupiravir for already hospitalized patients. In fairness, this has been a common pattern for many antivirals tested out during the pandemic and is at least partially due to the fact that severe illness from covid-19 tends to be caused by a destructive immune response, not the infection itself by that point. Moreover, studies of molnupiravir don’t seem to have found evidence of the harmful side effects Bright was concerned about, at least so far. Drugs suspected of causing mutagenic side effects have been approved in the past, usually with caveats against their use by currently pregnant or planning to be pregnant people.

 

Merck and Ridgeback are now planning to immediately submit the drug for emergency use authorization. Following that, the Food and Drug Administration and affiliated experts will be expected to pore over the safety and trial data and heavily discuss the drug’s potential risks and benefits. Should the drug win authorization, it may not be alone for long—several other antiviral pills for early covid-19 treatment and prevention are reaching the end of their clinical trials as well. The generic antidepressant fluvoxamine has also been shown to significantly prevent hospitalization from covid-19 in a large-scale but as yet not peer-reviewed trial.

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Bacteriophage and Antibiotic Combined to Fight Drug-Resistant Infections

Bacteriophage and Antibiotic Combined to Fight Drug-Resistant Infections | Amazing Science | Scoop.it

Researchers from the Université de Montpellier, France, and the University of Pittsburgh, have published a study (“Mycobacteriophage-antibiotic therapy promotes enhanced clearance of drug-resistant Mycobacterium abscessus”) in Disease Models & Mechanisms that describes the antibacterial effects of treating infections caused by the antibiotic-resistant bacteria M. abscessus with a bacteriophage and an antibiotic.

 

“Infection by multidrug-resistant Mycobacterium abscessus is increasingly prevalent in cystic fibrosis (CF) patients, leaving clinicians with few therapeutic options. A compassionate study showed the clinical improvement of a CF patient with a disseminated M. abscessus (GD01) infection, following injection of a phage cocktail, including phage Muddy. Broadening the use of phage therapy in patients as a potential antibacterial alternative necessitates the development of biological models to improve the reliability and successful prediction of phage therapy in the clinic,” write the investigators.

 

“Herein, we demonstrate that Muddy very efficiently lyses GD01 in vitro, an effect substantially increased with standard drugs. Remarkably, this cooperative activity was retained in an M. abscessus model of infection in CFTR-depleted zebrafish, associated with a striking increase in larval survival and reduction in pathological signs. The activity of Muddy was lost in macrophage-ablated larvae, suggesting that successful phage therapy relies on functional innate immunity.

 

“CFTR-depleted zebrafish represent a practical model to rapidly assess phage treatment efficacy against M. abscessus isolates, allowing the identification of drug combinations accompanying phage therapy and treatment prediction in patients.”

 

Previously, the Pittsburgh team had identified one bacteriophage out of 10,000, known as “Muddy,” that efficiently kills bacteria in a petri dish and could be a candidate for treating these infections in humans. However, the team wanted to find an alternative to testing their new therapy in patients.

 
Using zebrafish as a model organism

Knowing that human cystic fibrosis patients are particularly vulnerable to M. abscessus infections, Laurent Kremer, PhD, at the Université de Montpellier, and colleagues decided to test their new combination therapy on zebrafish carrying the key genetic mutation that causes cystic fibrosis in humans and mimics how our immune system responds to bacterial infections. Then the team obtained samples of an antibiotic-resistant form of M. abscessus from a cystic fibrosis patient to infect the cystic fibrosis zebrafish and test their new treatment.

 

First, they needed to find out how these cystic fibrosis zebrafish reacted to the M. abscessus infection. Monitoring the animals for 12 days, they found that the fish developed serious infections with abscesses and suffered a high death rate; only 20% survived.

Next the team tested how well the infected fish recovered when injected with Muddy, the antibacterial bacteriophage, over a period of 5 days. This time, the fish had much less severe infections, increased chances of survival (40%) and had fewer of the abscesses suffered by the fish during a severe infection.

 

Then the authors searched for an antibiotic to pair up with Muddy and found that rifabutin could treat the M. abscessus infection as effectively as the bacteriophage alone. After identifying rifabutin, Kremer and colleagues treated the infected fish for 5 days with the antibiotic and bacteriophage. With this combination treatment, the fishes’ infections were much less severe; the fishes’ survival rate reached 70% and they suffered far fewer abscesses. This is a significant improvement compared to fish treated with only the antibiotic, which had a 40% survival rate.

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Red dwarf starlight suitable to grow photosynthesizing bacteria

Red dwarf starlight suitable to grow photosynthesizing bacteria | Amazing Science | Scoop.it
Extremophiles grown under a starlight simulator suggest that exoplanets orbiting red dwarf stars may have conditions ripe for photosynthesis, say researchers.

 

Our nearest astronomical neighbor is Proxima Centauri, a tiny red dwarf star some 4.25 light-years from here. In recent years, Proxima has become the focus of huge attention. In 2016, astronomers discovered it hosted an Earth-sized exoplanet in the habitable zone where conditions should be ripe for liquid water.

Then last year, astronomers spotted an unusual radio signal that appeared to be coming from that part of sky. The most likely source of the signal is radio interference on Earth but various astronomers have discussed the possibility that it could be a technosignature from a Proxima Centauri civilization.

All this excitement masks a much more basic and obvious question, which is whether a red dwarf could host life at all, given that the light it produces is much cooler, dimmer and redder than the light that supports life on Earth.

Now we get an answer of sorts thanks to the work of Riccardo Claudi at the Astronomical Observatory of Padova in Italy and colleagues who have recreated the red dwarf light spectrum and shown that bacteria can harvest it for photosynthesis. Their work suggests that, at least as far as the spectrum of light is concerned, red dwarfs have the capability to host photosynthetic life forms. In turn, this hints at the kind of biosignature these lifeforms might present to distant observers, such as ourselves.

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Largest Real-World COVID-19 Vaccine Study Confirms Overwhelming Safety of Current Vaccines

Largest Real-World COVID-19 Vaccine Study Confirms Overwhelming Safety of Current Vaccines | Amazing Science | Scoop.it

A comparison of the medical histories of vaccinated and unvaccinated Israelis shows side effects from the Pfizer/BioNTech vaccine are rare and predominantly harmless.

 

Among 25 possible side effects explored in the study only four were more common among those that had been vaccinated than those that were not, and all remained uncommon. Meanwhile, infection raised the risk of far more serious conditions to a much greater extent. Myocarditis, inflammation of the heart muscle that can cause shortness of breath and irregular heartbeat, has been among the highest profile side effects of COVID-19 vaccination.

 

According to a new study in the New England Journal of Medicine of a substantial proportion of the Israeli population, it does occur at a higher rate among the vaccinated, but not by much. An extra 2.7 individuals in 100,000 were diagnosed with myocarditis compared to the unvaccinated population who hadn’t caught the disease. Most excess cases were among men aged 20 - 34. However, even if myocarditis was your only fear, it would still be advisable to get the vaccine anywhere COVID-19 is common. Among unvaccinated people who caught the disease the excess rate was 11 per 100,000 – four times as high.

 

The study found that easily the most common adverse event triggered by Pfizer vaccination is swelling of the lymph glands, which happens at an extra rate of 78 cases per 100,000. However, as a normal response to illness and something we will overcome many time in our lives, it's best not to risk death by virus in order to avoid. Likewise, the 16 additional cases per 100,000 of shingles (reactivation of past chickenpox virus infections) are unpleasant, but hardly life-threatening. The final and more serious side effect, appendicitis, occurs at just 5 excess cases per 100,000.

 

Meanwhile, a variety of other effects examined in the study were no more common among the vaccinated, but increased dramatically among unvaccinated people who caught COVID-19. These included kidney damage, pulmonary embolism, deep vein thrombosis and stroke with 125, 62, 43 and 14 excess cases per 100,000 respectively, along with several others. "These results show convincingly that this mRNA vaccine is very safe and that the alternative of 'natural' morbidity caused by the coronavirus puts a person at significant, higher and much more common risk of serious adverse events,” Professor Ran Balicer of the Clalit Research Institute said in a statement.

 

"To date, one of the main drivers of vaccine hesitancy has been a lack of information regarding potential side effects of the vaccine. This careful epidemiological study provides reliable information on vaccine safety, which we hope will be helpful to those who have not yet decided about vaccination,” added Harvard’s Dr Ben Reis.

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