In this illustration, glycans (dark blue) coat the SARS-CoV-2 spike protein (light blue), which is anchored in the viral envelope (colorful bilayer on bottom). Credit: Adapted from ACS Central Science 2020, DOI: 10.1021/acscentsci.0c01056
As the COVID-19 pandemic rages on, researchers are working overtime to develop vaccines and therapies to thwart SARS-CoV-2, the virus responsible for the disease Many efforts focus on the coronavirus spike protein, which binds the angiotensin-converting enzyme 2 (ACE2) on human cells to allow viral entry. Now, researchers reporting in ACS Central Science have uncovered an active role for glycans — sugar molecules that can decorate proteins — in this process, suggesting targets for vaccines and therapies.
Before the SARS-CoV-2 spike protein can interact with ACE2 on a human cell, it changes shape to expose its receptor binding domain (RBD), the part of the protein that interacts with ACE2. Like many viral proteins, the SARS-CoV-2 spike protein has a thick coat of glycans on its surface. These glycans, which are attached at specific sites, help shield the viral proteins from the host immune system. Rommie Amaro and colleagues at University of California San Diego, Maynooth University (Ireland) and the University of Texas at Austin wondered whether certain glycans in the SARS-CoV-2 spike protein might also be active players in the process leading to infection.
To find out, the researchers used structural and glycomic data to build molecular dynamics simulations of the SARS-CoV-2 spike protein embedded in the viral membrane. The computer models, which presented a detailed snapshot of every atom in the spike glycoprotein, revealed that N-glycans linked to the spike protein at certain sites (N165 and N234) helped stabilize the shape change that exposes the RBD, which could help promote infection. The simulations also identified regions of the spike protein that weren’t coated by glycans and thus could be vulnerable to antibodies, especially after the shape change. In laboratory experiments using biolayer interferometry, the team showed that mutating the spike protein so that it no longer had glycans at N165 and N234 reduced binding to ACE2. These results lay the foundation for new strategies to fight the pandemic threat, the researchers say.
Reference: 23 September 2020, ACS Central Science.
The authors acknowledge funding from the National Institutes of Health, the National Science Foundation, the Research Corporation for Science Advancement, UC San Diego Moores Cancer Center, the Irish Research Council, and the Visible Molecular Cell Consortium.
If we can harness it, quantum technology promises fantastic new possibilities. But first, scientists need to coax quantum systems to stay yoked for longer than a few millionths of a second.
A team of scientists at the University of Chicago’s Pritzker School of Molecular Engineering announced the discovery of a simple modification that allows quantum systems to stay operational—or “coherent”—10,000 times longer than before. Though the scientists tested their technique on a particular class of quantum systems called solid-state qubits, they think it should be applicable to many other kinds of quantum systems and could thus revolutionize quantum communication, computing and sensing.
The study was published Aug. 13 in Science.
“This breakthrough lays the groundwork for exciting new avenues of research in quantum science,” said study lead author David Awschalom, the Liew Family Professor in Molecular Engineering, senior scientist at Argonne National Laboratory and director of the Chicago Quantum Exchange. “The broad applicability of this discovery, coupled with a remarkably simple implementation, allows this robust coherence to impact many aspects of quantum engineering. It enables new research opportunities previously thought impractical.”
Down at the level of atoms, the world operates according to the rules of quantum mechanics—very different from what we see around us in our daily lives. These different rules could translate into technology like virtually unhackable networks or extremely powerful computers; the U.S. Department of Energy released a blueprint for the future quantum internet in an event at UChicago on July 23. But fundamental engineering challenges remain: Quantum states need an extremely quiet, stable space to operate, as they are easily disturbed by background noise coming from vibrations, temperature changes or stray electromagnetic fields.
Thus, scientists try to find ways to keep the system coherent as long as possible. One common approach is physically isolating the system from the noisy surroundings, but this can be unwieldy and complex. Another technique involves making all of the materials as pure as possible, which can be costly. The scientists at UChicago took a different tack.
“With this approach, we don’t try to eliminate noise in the surroundings; instead, we “trick” the system into thinking it doesn’t experience the noise,” said postdoctoral researcher Kevin Miao, the first author of the paper.
In tandem with the usual electromagnetic pulses used to control quantum systems, the team applied an additional continuous alternating magnetic field. By precisely tuning this field, the scientists could rapidly rotate the electron spins and allow the system to “tune out” the rest of the noise.
“To get a sense of the principle, it’s like sitting on a merry-go-round with people yelling all around you,” Miao explained. “When the ride is still, you can hear them perfectly, but if you’re rapidly spinning, the noise blurs into a background.”
This small change allowed the system to stay coherent up to 22 milliseconds, four orders of magnitude higher than without the modification—and far longer than any previously reported electron spin system. (For comparison, a blink of an eye takes about 350 milliseconds). The system is able to almost completely tune out some forms of temperature fluctuations, physical vibrations, and electromagnetic noise, all of which usually destroy quantum coherence.
The simple fix could unlock discoveries in virtually every area of quantum technology, the scientists said.
“This approach creates a pathway to scalability,” said Awschalom. “It should make storing quantum information in electron spin practical. Extended storage times will enable more complex operations in quantum computers and allow quantum information transmitted from spin-based devices to travel longer distances in networks.”
Though their tests were run in a solid-state quantum system using silicon carbide, the scientists believe the technique should have similar effects in other types of quantum systems, such as superconducting quantum bits and molecular quantum systems. This level of versatility is unusual for such an engineering breakthrough.
“There are a lot of candidates for quantum technology that were pushed aside because they couldn’t maintain quantum coherence for long periods of time,” Miao said. “Those could be re-evaluated now that we have this way to massively improve coherence.
“The best part is, it’s incredibly easy to do,” he added. “The science behind it is intricate, but the logistics of adding an alternating magnetic field are very straightforward.”
K. C. Miao et al, “Universal coherence protection in a solid-state qubit,” Science, Aug. 13, 2020. DOI: 10.1126/science.abc5186
Scientists discover way to make quantum states last 10,000 times longer (2020, August 13)
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Researchers have discovered an ancient relative of dinosaurs, a 4-inch reptile that lived 237 million years ago.
Known as Kongonaphon kely, the ancient reptile was a “tiny bug slayer” and lived in modern-day Madagascar, according to a study published in the journal Proceedings of the National Academy of Sciences. The fossil was first discovered in 1998 by a team of researchers from all over the world, including from the American Museum of Natural History.
“There’s a general perception of dinosaurs as being giants,” said the study’s lead author, Christian Kammerer, in a statement. “But this new animal is very close to the divergence of dinosaurs and pterosaurs, and it’s shockingly small.”
Life restoration of Kongonaphon kely, a newly described reptile near the ancestry of dinosaurs and pterosaurs, shown to scale with human hands. The fossils of Kongonaphon were found in Triassic (~237 million years ago) rocks in southwestern Madagascar and demonstrate the existence of remarkably small animals along the dinosaurian stem. (Credit: Frank Ippolito, American Museum of Natural History)
With the pointy, albeit worn, teeth, it’s likely that Kongonaphon fed on a diet of insects, the researchers stated. They also looked at a part of the reptile’s thigh bone to conclude that it was a full-grown creature and not a baby.
John Flynn, who helped discover the fossil in the late 1990s, said he was surprised at the diminutive size of Kongonaphon, but also how unique the discovery was.
“This fossil site in southwestern Madagascar from a poorly known time interval globally has produced some amazing fossils, and this tiny specimen was jumbled in among the hundreds we’ve collected from the site over the years,” Flynn added in the statement.
“It took some time before we could focus on these bones, but once we did, it was clear we had something unique and worth a closer look,” Flynn continued. “This is a great case for why field discoveries – combined with modern technology to analyze the fossils recovered – is still so important.”
Body size comparison between the newly discovered Kongonaphon kely (left) and one of the earliest dinosaurs, Herrerasaurus. (Credit: Phylopic.org by Scott Hartman (CC BY 3.0) Frank Ippolito, AMNH)
Project co-leader and study co-author Lovasoa Ranivoharimanana said the find shows how increasingly important Madagascar has become to archaeologists over the years, given the number of ancient fossils found on the African island.
“Discovery of this tiny relative of dinosaurs and pterosaurs emphasizes the importance of Madagascar’s fossil record for improving knowledge of vertebrate history during times that are poorly known in other places,” said Ranivoharimanana, professor and director of the vertebrate paleontology laboratory at the University of Antananarivo in Madagascar.
It’s believed that Kongonaphon may have belonged to Ornithodira, a group that includes dinosaurs and birds, but more research is needed to get a better understanding on their evolution.
“Recent discoveries like Kongonaphon have given us a much better understanding of the early evolution of ornithodirans,” Kammerer explained. “Analyzing changes in body size throughout archosaur evolution, we found compelling evidence that it decreased sharply early in the history of the dinosaur-pterosaur lineage.”
Experts continue to learn more about the early days of the dinosaurs. A study published last month found that some dinosaurs who faced scarce resources resorted to scavenging and possibly cannibalism.
A study published in March suggested dinosaurs traveled significantly shorter distances and had drastically different migration behavior than initially believed.
By combing through 30 years of earthquake data, the scientists discovered these new structures deep inside the Earth.
June 12, 2020
In wonderful, unexpected ways, Earth still manages to surprise scientists. A team of researchers from the University of Maryland in the U.S. has discovered a large structure made up of thick material near the Earth’s core.
That’s roughly 3,000 kilometers (1,864 miles) beneath your feet. The team used a machine-learning algorithm to probe this mysterious phenomenon occurring deep within our Earth.
Their findings were published in Science on Friday.
One of these big anomalies is located far below the Marquesas Islands in the Pacific Ocean, and has never been detected before. Another one of them is far beneath the Hawaiian Islands, also in the Pacific, and this one is much larger than was previously believed.
The team, led by Doyeon Kim, a seismologist and postdoctoral fellow at the University of Maryland, used seismograms from hundreds of different earthquakes between 1990 and 2018 and put them into a machine learning algorithm called Sequencer.
“This study is very special because, for the first time, we get to systematically look at such a large dataset that actually covers more or less the entire Pacific basin,” Kim said in a call to Vice.
After running thousands of seismograms through Sequencer, Kim and his team discovered that the strongest post cursor signals were found beneath the Marquesas and Hawai’i’s islands. This proves that there exist two “mega-ULVZs” zones that span around 1,000 kilometers (621 miles) or more.
Mega-ULVZs are huge structures that are made up of exotic materials that date back to the times before Earth had a Moon. “This is very interesting because this might indicate that mega-ULVZs are special and may host primitive geochemical signatures that have been relatively unmixed since early Earth history,” Kim explained.
The team plans on continuing its research deep beneath the Earth’s surface to develop a method of peering into Earth and find out what else is down there. The hope is to also look at what lies beneath the Atlantic Ocean.
“We’re hoping that Sequencer will be able to basically let us use all of these diverse datasets and bring them together to look for these lower mantle structures systematically,” Kim concluded. “That is our vision going forward, to answer more questions about the lower mantle in general.”
The similarities between this distant planet – named KOI-456.04 – and Earth are numerous, and researchers hope it could mean that the conditions there might be right for life. The observation was made by the Max Planck Institute for Solar System Research in Göttingen, Germany.
The Max Planck Society describes the star and its planet as a “mirror image” of the Earth and the Sun. They’re around 3,000 light-years away from Earth; roughly 17,636,000,000,000,000 miles away.
So far, scientists around the world have managed to spot over 4,000 exoplanets – that is, planets that exist outside of the solar system – the Max Planck Society said.
Scientists are usually interested to find planets that are similar to Earth, because this gives rise to the possibility that life might exist there.
To start with, KOI-456.04 orbits a star that is similar to the Sun. For one thing, this star – called Kepler-160 – actually emits plenty of visible light, which is something that most exoplanets’ stars don’t do.
Scientists noted many similarities between the planet and star and the Earth and the Sun. (Image: vjanes / Getty)
Kepler-160 is also very close to the Sun’s size – its radius is just 10 percent larger – and its surface temperature just 300 degrees cooler; next to nothing in astrophysical terms.
This is significant because most stars of exoplanets tend to be small and dim and mostly emit infrared radiation – belonging to the ‘red dwarf’ classification of stars.
This is a problem as far as life is concerned. Many red dwarfs are thought to emit radiation that fries any planets that get too close.
But since red dwarfs are cool and dim compared to the Sun, planets need to be relatively close in order to receive the amount of warmth that scientists think could lead to life.
Scientists are able to detect exoplanets by looking at repeated dimming of stars. (Image: Rain Ungert / Getty)
This also leads to other issues; the closer a planet is to its host star, the more likely it is to be badly affected by its gravity, resulting in rampant volcanism that would be fatal to any emerging life.
In short, an Earth-like exoplanet that is a candidate for life needs to orbit a star that’s of the right type at a very specific distance – close enough to get light and warmth and some volcanic activity, but far enough that it doesn’t get frazzled or torn apart by gravity.
Astrophysicists refer to this as the “habitable zone”, because it could mean that conditions are right for liquid water to exist, which is crucial for life as we know it to emerge.
This is why KOI-456.04 is so interesting. It fulfils these requirements, and the planet itself is rocky and relatively similar to Earth in terms of size.
Researchers think the exoplanet could recieve similar amounts of light to Earth. (Image: Universal History Archive / Getty)
Another similarity between KOI-456.04 and Earth is its orbital period – or how long its year is. Researchers put this at 378 days – just a little longer than Earth’s.
This means it’s likely that KOI-456.04 gets a similar amount of light as Earth – 93 percent similar, according to the researchers.
What’s more, KOI-456.04 is under twice the size of the Earth. For researchers this seems to be a key point, because almost all exoplanets less than twice the size of Earth that tend to have the potential for Earth-like surface temperatures usually orbit red dwarfs, rather than sun-lime stars such as Kepler-160.
Dr René Heller, led author of the new study, explained: “KOI-456.91 is relatively large compared to many other planets that are considered potentially habitable.
Space news: A new star and planet have been discovered (Image: EXPRESS)
“But it’s the combination of this less-than-double the size of the Earth planet and its solar type host star that make it so special and familiar.”
The research was conducted by a team of scientists from the Max Planck Society, the Sonneberg Observatory, the University of Göttingen, the University of California, and NASA.
Exoplanets can vary considerably in nature. Some might be small and rocky, like our own Mercury, or large gas giants, like Jupiter.
Most exoplanets tend to orbit red dwarf stars. (Image: Mark Garlick / Science Photo Library / Getty)
Incidentally, most exoplanets that are detected tend to be gas giants, according to the Max Planck Society. Typically they are like our own Neptune – large, gassy, and around four times the size of Earth.
In other words – probably not ideal conditions for life as we know it to emerge.
Scientists are able to detect planets around distant stars by looking at whether the star repeatedly dims in brightness – caused by a planet passing in front of it.
The stars speak! Understanding stars, including our own sun, has largely revolved around examining their outsides: the surfaces and surrounding atmospheres we can see. Although we can’t look inside a star, we can listen to the rumbling it makes based on pulsations and oscillations that occur in the interior. Studying the pulses, astronomers are able to decipher what’s happening in the heart of a star.
For a particular class of stars, known as delta Scuti stars, it has been difficult to nail down the rhythm. But now, thanks to NASA’s latest planet-hunting space telescope, astronomers have pulled back the insanely hot curtain on this class of stars to get a sense of what happens inside.
A new study, published in the journal Nature on Wednesday, details the rhythm of dozens of delta Scuti stars, which are about two times as massive as our sun, finding they exhibit clear, obvious rhythms. The discovery provides a new way for astronomers to understand the unusual physics occurring within the hearts of these stars, which are relatively common across the galaxy.
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To tune into the insides of the stars, astronomers at the University of Sydney turned to NASA’s Transiting Exoplanet Survey Satellite, which has been performing an extensive survey of the cosmos since its launch in 2018. The satellite is designed to hunt for planets around other stars by dividing the sky into sectors and taking snapshots of all the blazing furnaces in its field of view. Every two minutes, TESS grabs a quick image of the sky and measures the brightness of thousands of stars to determine how that changes over time. A dip in brightness might correspond to a planet passing in front of the star.
But the research team wasn’t looking for distant planets. Instead, it used the extremely precise changes in brightness detected by TESS to look at the stars themselves.The incredibly tiny changes in brightness correspond to pulsations and oscillations in the heart of the star. Because TESS can resolve the brightness of stars so exquisitely, it creates a great data set for trying to listen to a star’s heartbeat.
The team focused in on a batch of TESS data containing a sample of 92,000 stars and, with some clever coding, was able to develop a tool to quickly sift through the huge data set. A chance finding in the TESS data led to a list of around 1,000 stars with similar rhythms. Eventually, the researchers were able to nail down the list to 57 delta Scuti stars with discernible rhythms.
The stars are all relatively close to us, in galactic terms, lying between 60 and 1,400 light-years away. For reference, the Milky Way Galaxy is over 100,000 light-years wide.
Tim Bedding, an astronomer at the University of Sydney and first author on the paper, said the new data allowed his team to “cut through the noise.”
“Previously we were finding too many jumbled up notes to understand these pulsating stars properly,” he said in a release. “It was a mess, like listening to a cat walking on a piano.” Using the TESS data, things became a lot clearer. Bedding says now it’s more like “listening to nice chords being played.”
The rhythms of many other types of stars have been discovered in the last few decades, including those of huge, red giants like Betelgeuse, which has allowed astronomers to determine what’s happening inside the blazing hot balls of gas. Although delta Scuti stars are widely distributed across the universe, previous research had failed to find a regular rhythm.
“We think this is because they rotate rapidly, which makes the patterns less regular,” said Bedding.
With a pattern of pulses now understood, future research will be able to more accurately determine the age of stars and help astronomers pick apart how galaxies and star systems might evolve.
“We are now in a position to start to probe these stars, and to use them as benchmarks to help us interpret the huge numbers of other stars in the group that present more complicated pulsation spectra,” said Bill Chaplin, an astronomer at the University of Birmingham and co-author on the study.
NASA’s TESS is still surveying the sky and sending mountains of data back to Earth each month. Bedding says it’s sometimes likened to “drinking from a fire hose,” and there are many more sectors to look through. His team will now examine other, more complex delta Scuti stars to see if they can identify patterns.
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COVID-19, the disease that has caused the coronavirus pandemic, is a respiratory illness that has symptoms that can include fatigue, a persistent cough and fevers. However, researchers in Spain believe they have discovered another symptom —lesions on feet.
According to a statement from the Spanish General Council of Official Podiatrist Colleges, the lesions are described as similar to those seen with chickenpox and can largely be seen on the feet of children and adolescents. They have also been spotted on some adults.
“It is a curious finding that began yesterday to spread in the healthcare field, among dermatologists and podiatrists, fundamentally: the same symptoms are increasingly being detected in patients with COVID -19, especially children and adolescents, although some cases have also been detected in adults,” the statement reads. “These are purple-colored lesions (very similar to those of chickenpox, measles or chilblains) that usually appear around the toes and that usually heal without leaving marks on the skin.”
(Credit: General Council of Official Colleges of Podiatrists)
The lesions have been found in Italy, France and Spain, the researchers added.
Spain is the second-most affected country in the world, with nearly 185,000 cases. Italy and France have the third and fourth-most confirmed cases at 168,941 and 147,101 cases, respectively.
The statement added a link to a research paper from the International Federation of Podiatrists, specifically citing a case of a 13-year-old boy with lesions and no other symptoms of the virus.
As such, it’s possible the lesions could be a warning sign of the virus, with the council urging its members to be “very vigilant” in detecting what could be “a sign of COVID-19 detection that can help to avoid the spread.”