Saturn’s largest moon, Titan, also will fall under Webb’s powerful gaze. Titan is unique because it is the only moon in our solar system with a substantial atmosphere. In fact, it’s bigger than the planet Mercury. The atmospheric pressure on Titan is about 50% greater than on Earth. Like Earth, that atmosphere is mostly nitrogen, but Titan also has vaporous hydrocarbons like methane. Titan also is much colder than Earth, with a surface temperature around minus 290° Fahrenheit (minus 180° Celsius).
Within Titan’s atmosphere, chemical reactions are constantly churning its composition. Molecules are broken up into their constituents like carbon, hydrogen, oxygen and nitrogen. Those atoms form new molecules, which percolate through the air and settle at whichever pole is currently experiencing winter.
“Titan’s atmosphere is like a big chemistry lab,” said Conor Nixon of NASA’s Goddard Space Flight Center, Greenbelt, Maryland, a principal investigator on the program. Nixon and his colleagues will use Webb’s Near-Infrared Spectrograph (NIRSpec) and Mid Infrared Imager (MIRI) to study these molecules in much greater detail than Cassini’s instruments allowed.
Titan also is the only object in our solar system besides Earth with liquid seas and lakes on its surface. While Earth has a water cycle in which water evaporates, falls as rain, and flows down rivers to the ocean, Titan experiences a similar cycle with methane. On Titan, methane rain carves river beds through rock-hard water ice before flowing into tar-edged seas. Cassini and its Huygens probe from the European Space Agency, which landed on Titan in 2004, made remarkable discoveries about this Saturnian moon. Webb will study Titan’s seasonal climate cycles to compare them to astronomers’ models.
“Titan has clouds and weather that we can see changing in real time. Its chemistry is very different from Earth’s, but it’s still organic, carbon-based chemistry,” said Stefanie Milam of NASA Goddard, a co-investigator on the program.
While Webb’s mission lifetime after launch is designed to be at least 5-1/2 years, it could potentially last 10 years or more. As a result, it could watch Saturn go from northern summer through the autumnal equinox and back to southern spring. That would nearly “complete the circle” begun when Cassini arrived during southern summer.
“We will genuinely have covered an entire Saturnian year. That would be quite an eye-opening experience,” said Fletcher.
The James Webb Space Telescope will be the world's premier space science observatory when it launches in 2021. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
The success of the HPV vaccination offers hope of one day eradicating cervical cancer, say scientists who carried out a major review of evidence. Vaccination against the human papilloma virus, which causes most cervical cancers, began over a decade ago.
A Lancet review of 65 studies covering 60 million people showed a fall in HPV cases and in pre-cancerous growths. Over decades, this should translate into a significant fall, and possible eradication, of the cancer they said. Jo's Cervical Cancer Trust said the data should boost faith in the jab.
HPV is the name for a common group of viruses; there are more than 100 types of HPV
Many women will be infected with HPV over the course of their lifetime, with no ill effect
Most cervical cancers are caused by infection from a high-risk HPV
Others cause conditions including genital warts and cancers of the head and neck
The vaccine, given as two injections to girls aged 12 and 13, protects against four types of HPV - 16 and 18, which are linked to more than 70% of cervical cancers - and six and 11, which cause about 90% of genital warts
Girls who miss the HPV jab at school can still get it for free on the NHS up to the age of 25
It is also available privately, costing around £150 per dose
Boys aged 12-13 will also be offered the jab from September this year
The vaccine does not protect against all the types of HPV that can cause cervical cancer, so women still need to go for regular screening
There are 3,200 cases of cervical cancer and 850 deaths from the disease each year.
'Real-world' evidence
The review covered studies in 14 high-income countries, including the UK. They looked at HPV rates, plus cases of genital warts and pre-cancerous cells in the cervix called CIN.
It found that when rates were compared before vaccination started and eight years after:
Cases of HPV 16 and 18 were down 83% in girls aged 15-19 - 66% in women 20-24
Genital warts cases fell 67% in girls 15-19 - 54% in women 20-24
Pre-cancerous growths were down by 51% in girls 15-19 - 31% in women 20-24
It also showed people who were not vaccinated benefited. Cases of genital warts in boys aged 15-19 fell by almost 50%, and also significantly in women over 30.
The laws of physics are not time-reversal invariant. Here's how we know.
No matter when, where, or what you are in the Universe, you experience time in only one direction: forwards. In our everyday experiences, clocks never run backwards; scrambled eggs never uncook and unscramble themselves; shattered glass never spontaneously reassembles itself. But if you were to look at the laws of physics that govern the way the Universe works — from Newton's laws of motion down to the quantum physics of subatomic particles — you'd find something peculiar and unexpected: the rules are exactly the same whether time runs forwards or backwards.
This corresponds to a certain symmetry of nature: T-symmetry, or time-reversal invariance. Our everyday experience indicates to us, quite strongly, that the laws of physics must violate this symmetry, but for decades, we couldn't demonstrate it. But a few years ago, we experimentally proved the laws of physics are different depending on which direction time runs. Here's how we know.
There are two very, very good (but indirect) reasons to believe that T-symmetry must be broken at some deep, fundamental level. The first is a proven theorem known as the CPT theorem. If you have a quantum field theory that obeys the rules of relativity — i.e., is Lorentz invariant — that theory must exhibit CPT-symmetry.
There are three symmetries that are both discrete and fundamental in the context of the Standard Model of particle physics:
C-symmetry, which demands that you replace all particles with their antiparticles,
P-symmetry, which demands that you replace all particles with their mirror-image reflections, and
T-symmetry, which demands that you run the laws of physics backwards in time instead of forwards.
The CPT theorem tells us that the combination of all three symmetries must always be preserved. In other words, a spinning particle moving forwards in time must obey the same rules as its antiparticle spinning in the opposite direction moving backwards in time. If C-symmetry is violated, then PT-symmetry must also be violated by an equal amount to keep the combination conserved.
As CP-symmetry violation has already been observed (dating back to 1964), we know that T-symmetry must be violated as well.
The second reason is that we live in a Universe where there's more matter than antimatter, but the laws of physics we know are completely symmetric between matter and antimatter.
It's true that there must necessarily be additional physics to what we've observed to explain this asymmetry, but there are significant restrictions on the types of new physics that can cause it. They were elucidated by Andrei Sakharov in 1967, who noted:
The Universe must be in an out-of-equilibrium state.
Both C-symmetry and CP-symmetry must be violated.
And baryon number-violating interactions must occur.
Even if we hadn't observed CP-violating interactions directly, we'd have known that they must occur in order to create a Universe that's consistent with what we observe. And therefore, since again T-violation is necessarily implied by CP-violation, T-symmetry cannot always hold true.
Researchers from the University of Turku have discovered a new route that transports subcutaneously administered antibodies into lymph nodes in just a few seconds. The discovery enables targeted therapies for the immune system.
Many of the immune defence reactions are launched in the lymph nodes. For instance, small, foreign molecules that pass through the skin are directed through lymphatic vessels to the draining lymph node where they are presented to white blood cells. However, the reticular conduits inside the lymph node are so small that large molecules cannot be transported through the system. Therefore, it has been thought that subcutaneously administered antibodies pass through the lymphatic vessels straight into the blood circulation bypassing the lymph nodes entirely.
Researchers from the University of Turku, Finland, have discovered in an experimental model that a new mechanism allows the antibodies to enter the lymph node directly. Doctoral Candidates Laura Kähäri and Ruth Fair-Mäkelä as well as Docent Kaisa Auvinen from the research group of Professor Marko Salmi discovered that antibodies pass through lymphatic endothelial cells covering the surface of the lymph node via a previously unknown mechanism.
It was a surprise to discover subcutaneously administered antibodies in the parenchyma of the draining lymph node. The delivery of the antibody was extremely efficient. It was transported from the skin into the lymph node in just a few seconds. When using a small dose, the antibody was found only in the draining lymph node in addition to the site of administration, and nowhere else in the body, says Kähäri.
It's exciting that the antibodies are delivered in an intact form to the targeted draining lymph node. By using this new delivery route, we can activate or inhibit inflammation locally, adds Fair-Mäkelä.
In a paper released today in Science Advances, Australian researchers describe the first observation of a native ferroelectric metal: a native metal with bistable and electrically switchable spontaneous polarization states--the hallmark of ferroelectricity.
The study found coexistence of native metallicity and ferroelectricity in bulk crystalline tungsten ditelluride (WTe2) at room temperature. A van-der-Waals material that is both metallic and ferroelectric in its bulk crystalline form at room temperature has potential for nano-electronics applications.
The use of electric propulsion for raising satellites into geostationary orbit can result in significant solar cell degradation according to a new study. The extended journey results in greater exposure to the damaging effects of space weather. Understanding the size of this risk is essential for commercial operators to take steps to mitigate the effects and protect their assets.
The new research by British Antarctic Survey, University of Cambridge, and DH Consultancy – published this month in the journal Space Weather – is being presented at the Royal Astronomical Society’s National Astronomy Meeting today (1 July 2019). The new study concludes that after a radiation storm, maximum solar cell output power could be reduced by up to 8% by the time satellites reach their target destination using electric orbit raising. This is equivalent to the level of damage that would be expected after spending around 15 years at geostationary orbit.
During a radiation storm, charged particles released by the Sun become trapped within Earth’s magnetic field, forming the Van Allen radiation belts which encircle Earth, and collisions with these charged particles causes damage to the solar cells. This degradation is up to 8% of output power in a worst-case scenario, but even in a quiet environment, the study predicts a 1-3% reduction in output.
A method of weighing the quantities of matter in galaxy clusters—the largest objects in our universe—has shown a balance between the amounts of hot gas, stars and other materials.
The results are the first to use observational data to measure this balance, which was theorized 20 years ago, and will yield fresh insight into the relationship between ordinary matter that emits light and dark matter, and about how our universe is expanding. Galaxy clusters are the largest objects in the universe, each composed of around 1,000 massive galaxies. They contain vast amounts of dark matter, along with hot gas and cooler "ordinary matter," such as stars and cooler gas.
In a new study, published in Nature Communications, an international team led by astrophysicists from the University of Michigan in the US and the University of Birmingham in the UK used data from the Local Cluster Substructure Survey (LoCuSS) to measure the connections between the three main mass components that comprise galaxy clusters—dark matter, hot gas, and stars.
Members of the research team had spent 12 years gathering data, which span a factor of 10 million in wavelength, using the Chandra and XMM-Newton satellites, the ROSAT All-sky survey, Subaru telescope, United Kingdom Infrared Telescope (UKIRT), Mayall Telescope, the Sunyaev Zeldovich Array, and the Planck satellite.
Using sophisticated statistical models and algorithms built by Dr. Arya Farahi during his doctoral studies at the University of Michigan the team was able to conclude that the sum of gas and stars across the clusters that they studied is a nearly fixed fraction of the dark matter mass. This means that as stars form, the amount of hot gas available will decrease proportionally
"This validates the predictions of the prevailing cold dark matter theory. Everything is consistent with our current understanding of the universe," said Dr. Farahi, currently a McWilliams Postdoctoral Fellow in the Department of Physics at Carnegie Mellon University.
Dr. Graham Smith of the School of Physics and Astronomy at the University of Birmingham and Principal Investigator of LoCuSS, says: "A certain amount of material within the universe collapses to form galaxy clusters. "But once they are formed, these clusters are 'closed boxes.' The hot gas has either formed stars, or still remains as gas, but the overall quantity remains constant."
"This research is powered by more than a decade of telescope investments," adds Professor August E. Evrard, of the University of Michigan. "Using this high quality data, we were able to characterize 41 nearby galaxy clusters and find a special relationship, specifically anti-correlated behavior between the mass in stars and the mass in hot gas. This is significant because these two measurements together give us the best indication of the total system mass."
Fast radio bursts (FRBs) are among the most enigmatic and powerful events in the cosmos. Around 80 of these events—intensely bright millisecond-long bursts of radio waves coming from beyond our galaxy—have been witnessed so far, but their causes remain unknown.
In a rare feat, researchers at Caltech's Owens Valley Radio Observatory (OVRO) have now caught a new burst, called FRB 190523, and, together with the W. M. Keck Observatory in Hawaii, have pinpointed its origins to a galaxy 7.9 billion light-years away. Identifying the galaxies from which these radio bursts erupt is a critical step toward solving the mystery of what triggers them. A paper about the discovery appears online July 2, 2019 in Nature.
Before this new discovery, only one other burst, called FRB 121102, had been localized to a host galaxy. FRB 121102 was reported in 2014 and then later, in 2017, was pinpointed to a galaxy lying 3 billion light-years away. Recently, a second localized FRB was announced on June 27, 2019. Called FRB 180924, this burst was discovered by a team using the Australian Square Kilometer Array Pathfinder and traced to a galaxy about 4 billion light-years away.
FRB 121102 was easiest to find because it continues to burst every few weeks. Most FRBs, however—including the Australian and OVRO finds—just go off once, making the job of finding their host galaxies harder. "Finding the locations of the one-off FRBs is challenging because it requires a radio telescope that can both discover these extremely short events and locate them with the resolving power of a mile-wide radio dish," says Vikram Ravi, a new assistant professor of astronomy at Caltech who works with the radio telescopes at OVRO, which is situated east of the Sierra Nevada mountains in California.
Another genetically edited baby is due, but the world may never learn of its birth if the Chinese government decides to keep it a secret.
The Second International Summit on Human Genome Editing, held in Hong Kong last November, was meant to debate the pros and cons of genetically engineering humans. Instead, the proceedings were turned upside down by the revelation that He Jiankui, a Chinese biophysicist, had already done it. He’d gone ahead and edited the DNA of twin girls with the powerful gene modification tool called CRISPR.
Then the Chinese scientist sprang a further surprise on the shocked gene-editing experts. A second Chinese woman, he said, was pregnant with yet another CRISPR baby. An early pregnancy test had confirmed it. That third CRISPR baby is now due to be born at any moment—if he or she hasn’t come crying into the world already.
Seven months have passed since the Hong Kong summit, but because the pregnancy was already under way by then, it is now at term, according to William Hurlbut, a Stanford University physician and ethicist who was in regular communication with He starting in 2017 and is familiar with the time line of events. Hurlbut knows the day the third baby was conceived but won’t make it public, because of the risk the information could identify the parents and child. “What I can say is that a normal birth is 38 to 42 weeks, and it’s pretty close to the center of that,” Hurlbut told MIT Technology Review.
Now the guessing game among CRISPR watchers is whether China’s government will ever acknowledge the third CRISPR baby. Rosario Isasi, a bioethicist at the University of Miami, says she has encouraged science leaders there to “make a statement and do damage control.”
But the government may not want more attention, and experts in China are reluctant to discuss He’s experiment on social-media networks such as WeChat, which are monitored. “The government is extremely aware of any transgressions. They have the Tiananmen anniversary, they have the Hong Kong protests, and they have the CRISPR babies,” says Isasi.
Every type of atom in the universe has a unique fingerprint: It only absorbs or emits light at the particular energies that match the allowed orbits of its electrons. That fingerprint enables scientists to identify an atom wherever it is found. A hydrogen atom in outer space absorbs light at the same energies as one on Earth.
While physicists have learned how electric and magnetic fields can manipulate this fingerprint, the number of features that make it up usually remains constant. In work published July 3, 2019, in the journal Nature, University of Chicago researchers challenged this paradigm by shaking electrons with lasers to create "doppelgänger" features at new energies—a breakthrough that lets scientists create hybrid particles which are part-atom and part-light, with a wide variety of new behaviors.
The research is part of a greater effort in Assoc. Prof. Jonathan Simon's lab to break down the walls between matter and light, in order to investigate their fundamental properties. In addition to learning about how materials behave at the quantum level, this work could one day help create more powerful computers or virtually "unhackable" quantum communications.
One step along the way to making matter out of light is to make individual packets of light, called photons, interact with each other like matter does. Normally photons zip along at the speed of light and don't react to each other at all. "In order to make photons collide with one another, we use atoms as a go-between," said postdoctoral researcher Logan Clark, who led the research. "But we were running into a problem because the photons only interact with atoms whose electronic orbitals are at very particular energies. So we asked: What if we could make copies of the orbitals at whatever energies we wanted?"
Clark had already developed techniques to manipulate quantum matter by shaking it —called Floquet engineering—as part of his Ph.D. project. The right sort of shaking naturally produces copies of quantum states at multiple energies along the way. "We had always viewed the copies as a side effect rather than the goal," he said, "but this time, we shook our electrons with the specific intent of making the copies."
Gravitational-wave astronomy is shedding new light on some of the most enigmatic issues in contemporary physics, ranging from black holes to the formation of the Universe.
The grand challenges of contemporary fundamental physics—dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem—all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harboring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions.
The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields.
The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature.
The purpose of this collaborative work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'.
Researchers from the Yokohama National University have teleported quantum information securely within the confines of a diamond. The study has big implications for quantum information technology - the future of how sensitive information is shared and stored. The work was published on June 28, 2019 in Communications Physics.
"Quantum teleportation permits the transfer of quantum information into an otherwise inaccessible space," said Hideo Kosaka, a professor of engineering at Yokohama National University and an author on the study. "It also permits the transfer of information into a quantum memory without revealing or destroying the stored quantum information."
The inaccessible space, in this case, consisted of carbon atoms in diamond. Made of linked, yet individually contained, carbon atoms, a diamond holds the perfect ingredients for quantum teleportation.
A carbon atom holds six protons and six neutrons in its nucleus, surrounded by six spinning electrons. As the atoms bond into a diamond, they form a notoriously strong lattice. Diamonds can have complex defects, though, when a nitrogen atom exists in one of two adjacent vacancies where carbon atoms should be. This defect is called a nitrogen-vacancy center.
Surrounded by carbon atoms, the nucleus structure of the nitrogen atom creates what Kosaka calls a nanomagnet. To manipulate an electron and a carbon isotope in the vacancy, Kosaka and the team attached a wire about a quarter the width of a human hair to the surface of a diamond. They applied a microwave and a radio wave to the wire to build an oscillating magnetic field around the diamond. They shaped the microwave to create the optimal, controlled conditions for the transfer of quantum information within the diamond.
Kosaka then used the nitrogen nanomagnet to anchor an electron. Using the microwave and radio waves, Kosaka forced the electron spin to entangle with a carbon nuclear spin - the angular momentum of the electron and the nucleus of a carbon atom. The electron spin breaks down under a magnetic field created by the nanomagnet, allowing it to become susceptible to entanglement.
Once the two pieces are entangled, meaning their physical characteristics are so intertwined they cannot be described individually, a photon which holds quantum information is applied and the electron absorbs the photon. The absorption allows the polarization state of the photon to be transferred into the carbon, which is mediated by the entangled electron, demonstrating a teleportation of information at the quantum level.
A team of researchers has isolated a new giant virus from hot spring water in Japan. Named medusavirus, the virus infects a species of amoeba called Acanthamoeba castellanii and can turn its host into a stone-like cyst.
Recent discoveries of new large DNA viruses reveal high diversity in their morphologies, genetic repertoires, and replication strategies. Scientists now report the novel features of a so-called medusavirus, a large DNA virus newly isolated from hot spring water in Japan.
Medusavirus, with a diameter of 260 nm, shows a T=277 icosahedral capsid with unique spherical-headed spikes on its surface. It has a 381-kb genome encoding 461 putative proteins, 86 of which have their closest homologs in Acanthamoeba, whereas 279 (61%) are orphan genes.
The virus lacks the genes encoding DNA topoisomerase II and RNA polymerase, showing that DNA replication takes place in the host nucleus, whereas the progeny virions are assembled in the cytoplasm. Furthermore, the medusavirus genome harbors genes for all five types of histones (H1, H2A, H2B, H3, and H4) and one DNA polymerase, which phylogenetically places the medusavirus at the root of the eukaryotic clades. The host amoeba itself encodes many medusavirus homologs, including the major capsid protein. This strongly suggests that amoebae are indeed the most likely natural hosts of medusaviruses, and that lateral gene transfer has taken place repeatedly and bidirectionally between the virus and its host since the early stage of their coevolution.
Medusaviruses reflect the traces of direct evolutionary interactions between the virus and their eukaryotic hosts, which may be caused by sharing the DNA replication compartments and by evolutionary long lasting virus-host relationships.
“A squid lens is infinitely more elegant than our eye,” says Alison Sweeney, associate professor of physics and astronomy at the University of Pennsylvania. “The resolution of their eyes is approaching that of humans, their retinas are much more sensitive than ours are to light, and if you dig into the nitty-gritty of how nature figured it out, I’m forever blown away at the level of nuance to get it to work.”
Sweeney studies the evolution of novel materials in nature like wood, muscles, bones, and more. She looks at these things as materials, much like an engineer, and tries to figure out how they came to be. She’s looking at squid eyes due to their large numbers, or as she put it, “if you were a Martian who swooped down and scooped up exactly one animal off of Earth, you are more likely than not to get something transparent and bioluminescent that came from 400 meters in the ocean, because that’s where 99% of the space is.”
Mid-ocean squid live in a world very different than our own. Unlike visually stimulating forests, cities, or reefs that other creatures live in, the world 400 meters below the surface of the ocean is gloomy and featureless. There’s nothing around for miles, and it’s about as bright at noon as a night with a full moon. But “if you’re a squid that’s been evolving for 400 million years to live at that depth,” says Sweeney, “you can see great.”
Squid lenses are filled with S-crystallin protein, which were thought to just float in solution. But squid have a trick up their sleeve. In order to get around the sphere-shaped lens problem, squid have evolved to put denser proteins at the center of the lens and less dense proteins at the edges, producing a crisp image every time.
“It’s really sort of a neat trick to find a way to put proteins together in a whole bunch of different densities, such that none of them are going to require any energy to maintain that structure,” says Sweeney.
To see the structure of the squid’s special S-crystallin proteins, the team shot an X-ray through the lens—and they discovered something fascinating. “What we saw was: A squid lens genuinely self-assembles into this really cool, higher order complex optical structure,” says Sweeney. Imagine you want to build a LEGO castle, she says, and that you “had a bunch of little bricks, put it into a bag, and shake the bag, the castle will just come out again. That’s essentially what the squid lens proteins do.”
Astronomers enlisted the combined multi-wavelength capabilities of NASA's Hubble and Spitzer space telescopes to assemble for the first time a "fingerprint" of the chemical composition of exoplanet GJ 3470 b's atmosphere, and found it to be mostly hydrogen and helium, and surprisingly, largely lacking heavier elements.
This artist's illustration shows the theoretical internal structure of the exoplanet GJ 3470 b. It is unlike any planet found in the our own solar system. Weighing in at 12.6 Earth masses the planet is more massive than Earth but less massive than Neptune. Unlike Neptune, which is 3 billion miles from the Sun, GJ 3470 b may have formed very close to its red dwarf star as a dry, rocky object. It then gravitationally pulled in hydrogen and helium gas from a circumstellar disk to build up a thick atmosphere. The disk dissipated many billions of years ago, and the planet stopped growing. The bottom illustration shows the disk as the system may have looked long ago. Observation by NASA's Hubble and Spitzer space telescopes have chemically analyzed the composition of GJ 3470 b's very clear and deep atmosphere, yielding clues to the planet's origin. Many planets of this mass exist in our galaxy.
By inventorying the contents of GJ 3470 b's atmosphere, astronomers are able to uncover clues about the planet's nature and origin. "This is a big discovery from the planet formation perspective. The planet orbits very close to the star and is far less massive than Jupiter—318 times Earth's mass—but has managed to accrete the primordial hydrogen/helium atmosphere that is largely "unpolluted" by heavier elements," said Björn Benneke of the University of Montreal, Canada. "We don't have anything like this in the solar system, and that's what makes it striking."
Astronomers enlisted the combined multi-wavelength capabilities NASA's Hubble and Spitzer space telescopes to do a first-of-a-kind study of GJ 3470 b's atmosphere. This was accomplished by measuring the absorption of starlight as the planet passed in front of its star (transit) and the loss of reflected light from the planet as it passed behind the star (eclipse). All totaled, the space telescopes observed 12 transits and 20 eclipses. The science of analyzing chemical fingerprints based on light is called "spectroscopy." "For the first time we have a spectroscopic signature of such a world," said Benneke. But he is at a loss for classification: Should it be called a "super-Earth" or "sub-Neptune?" Or perhaps something else? Fortuitously, the atmosphere of GJ 3470 b turned out to be mostly clear, with only thin hazes, enabling the scientists to probe deep into the atmosphere. "We expected an atmosphere strongly enriched in heavier elements like oxygen and carbon which are forming abundant water vapor and methane gas, similar to what we see on Neptune", said Benneke. "Instead, we found an atmosphere that is so poor in heavy elements that its composition resembles the hydrogen/helium rich composition of the Sun."
Other exoplanets called "hot Jupiters" are thought to form far from their stars, and over time migrate much closer. But this planet seems to have formed just where it is today, says Benneke. The most plausible explanation, according to Benneke, is that GJ 3470 b was born precariously close to its red dwarf star, which is about half the mass of our Sun. He hypothesizes that essentially it started out as a dry rock, and rapidly accreted hydrogen from a primordial disk of gas when its star was very young. The disk is called a "protoplanetary disk." "We're seeing an object that was able to accrete hydrogen from the protoplanetary disk, but didn’t runaway to become a hot Jupiter," said Benneke. "This is an intriguing regime."
NASA's upcoming James Webb Space Telescope will be able to probe even deeper into GJ 3470 b's atmosphere thanks to the Webb's unprecedented sensitivity in the infrared. The new results have already spawned large interest by American and Canadian teams developing the instruments on Webb. They will observe the transits and eclipses of GJ 3470 b at light wavelengths where the atmospheric hazes become increasingly transparent.
Scientists on the DZero collaboration at the U.S. Department of Energy’s Fermilab have discovered a new particle—the latest member to be added to the exotic species of particle known as tetraquarks.
Quarks are point-like particles that typically come in packages of two or three, the most familiar of which are the proton and neutron (each is made of three quarks). There are six types, or “flavors,” of quark to choose from: up, down, strange, charm, bottom and top. Each of these also has an antimatter counterpart.
Over the last 60 years, scientists have observed hundreds of combinations of quark duos and trios. In 2003 scientists on the Belle experiment in Japan reported the first evidence of quarks hanging out as a foursome, forming a tetraquark. Since then physicists have glimpsed a handful of different tetraquark candidates, including now the recent discovery by DZero—the first observed to contain four different quark flavors.
DZero is one of two experiments at Fermilab’s Tevatron collider. Although the Tevatron was retired in 2011, the experiments continue to analyze billions of previously recorded events from its collisions. As is the case with many discoveries, the tetraquark observation came as a surprise when DZero scientists first saw hints in July 2015 of the new particle, called X(5568), named for its mass—5568 megaelectronvolts. “At first, we didn’t believe it was a new particle,” says DZero co-spokesperson Dmitri Denisov. “Only after we performed multiple cross-checks did we start to believe that the signal we saw could not be explained by backgrounds or known processes, but was evidence of a new particle.”
And the X(5568) is not just any new tetraquark. While all other observed tetraquarks contain at least two of the same flavor, X(5568) has four different flavors: up, down, strange and bottom. “The next question will be to understand how the four quarks are put together,” says DZero co-spokesperson Paul Grannis. “They could all be scrunched together in one tight ball, or they might be one pair of tightly bound quarks that revolves at some distance from the other pair.”
Four-quark states are rare, and although there’s nothing in nature that forbids the formation of a tetraquark, scientists don’t understand them nearly as well as they do two- and three-quark states.
This latest discovery comes on the heels of the first observation of a pentaquark—a five-quark particle—announced last year by the LHCb experiment at the Large Hadron Collider. Scientists will sharpen their picture of the quark quartet by making measurements of properties such as the ways X(5568) decays or how much it spins on its axis. Like investigations of the tetraquarks that came before it, the studies of the X(5568) will provide another window into the workings of the strong force that holds these particles together. And perhaps the emerging tetraquark species will become an established class in the future, showing themselves to be as numerous as their two- and three-quark siblings.
Everyday transitions from one state of matter to another—such as freezing, melting or evaporation—start with a process called "nucleation," in which tiny clusters of atoms or molecules (called "nuclei") begin to coalesce. Nucleation plays a critical role in circumstances as diverse as the formation of clouds and the onset of neurodegenerative disease.
A UCLA-led team has gained a never-before-seen view of nucleation—capturing how the atoms rearrange at 4-D atomic resolution (that is, in three dimensions of space and across time). The findings, published in the journal Nature, differ from predictions based on the classical theory of nucleation that has long appeared in textbooks.
"This is truly a groundbreaking experiment—we not only locate and identify individual atoms with high precision, but also monitor their motion in 4-D for the first time," said senior author Jianwei "John" Miao, a UCLA professor of physics and astronomy, who is the deputy director of the STROBE National Science Foundation Science and Technology Center and a member of the California NanoSystems Institute at UCLA.
Research by the team, which includes collaborators from Lawrence Berkeley National Laboratory, University of Colorado at Boulder, University of Buffalo and the University of Nevada, Reno, builds upon a powerful imaging technique previously developed by Miao's research group. That method, called "atomic electron tomography," uses a state-of-the-art electron microscope located at Berkeley Lab's Molecular Foundry, which images a sample using electrons. The sample is rotated, and in much the same way a CAT scan generates a three-dimensional X-ray of the human body, atomic electron tomography creates stunning 3-D images of atoms within a material.
NASA announced plans to send a flying rotorcraft to Saturn’s moon Titan to study its surface and atmosphere for signs of past and possibly present forms of microbial life. Why rove when you can fly?
Named Dragonfly, the spacecraft, which is set to launch in 2026 and reach its target in 2034, will function like a large drone, flying to numerous sites, where its science instruments will analyze surface composition, atmospheric properties, and subsurface oceans and lakes to search for chemical evidence of life in both the present and distant past, and determine how far pre-biotic chemistry has evolved. The mission is a project of NASA’s New Frontiers program, which explores solar system locations deemed scientifically interesting.
Rich in organic compounds that make up the building blocks of life, Titan is considered by many scientists to be an analogue of early Earth. Its atmosphere is composed mostly of nitrogen, much like Earth’s is, and contains clouds from which methane rain falls. Weather on Titan has shaped surface properties, creating sand dunes composed of organic materials. Some organics are produced in clouds and fall to the surface as snow.
Titan has three conditions that make it potentially habitable for microbial life. These are the complex organic compounds formed by weather and surface processes, water, and energy, all of which make the moon a perfect laboratory to provide scientists with important insights as to how life began on Earth.
Jigang Wang patiently explained his latest discovery in quantum control that could lead to superfast computing based on quantum mechanics: He mentioned light-induced superconductivity without energy gap. He brought up forbidden supercurrent quantum beats. And he mentioned terahertz-speed symmetry breaking.
Then he backed up and clarified all that. After all, the quantum world of matter and energy at terahertz and nanometer scales — trillions of cycles per second and billionths of meters — is still a mystery to most of us.
“I like to study quantum control of superconductivity exceeding the gigahertz, or billions of cycles per second, bottleneck in current state-of-the-art quantum computation applications,” said Wang, a professor of physics and astronomy at Iowa State University whose research has been supported by the Army Research Office. “We’re using terahertz light as a control knob to accelerate supercurrents.”
Superconductivity is the movement of electricity through certain materials without resistance. It typically occurs at very, very cold temperatures. Think -400 Fahrenheit for “high-temperature” superconductors.
Terahertz light is light at very, very high frequencies. Think trillions of cycles per second. It’s essentially extremely strong and powerful microwave bursts firing at very short time frames. Wang and a team of researchers demonstrated such light can be used to control some of the essential quantum properties of superconducting states, including macroscopic supercurrent flowing, broken symmetry and accessing certain very high-frequency quantum oscillations thought to be forbidden by symmetry. It all sounds esoteric and strange. But it could have very practical applications.
“Light-induced supercurrents chart a path forward for electromagnetic design of emergent materials properties and collective coherent oscillations for quantum engineering applications,” Wang and several co-authors wrote in a research paper just published online by the journal Nature Photonics.
Scientists led by the USF College of Marine Science used NASA satellite observations to discover the largest bloom of macroalgae in the world called the Great Atlantic Sargassum Belt (GASB), as reported in Science.
They confirmed that the belt of brown macroalgae called Sargassum forms its shape in response to ocean currents, based on numerical simulations. It can grow so large that it blankets the surface of the tropical Atlantic Ocean from the west coast of Africa to the Gulf of Mexico. This happened last year when more than 20 million tons of it—heavier than 200 fully loaded aircraft carriers—floated in surface waters and some of which wreaked havoc on shorelines lining the tropical Atlantic, Caribbean Sea, Gulf of Mexico, and east coast of Florida.
The team also used environmental and field data to suggest that the belt forms seasonally in response to two key nutrient inputs: one human-derived, and one natural. In the spring and summer, Amazon River discharge adds nutrients to the ocean, and such discharged nutrients may have increased in recent years due to increased deforestation and fertilizer use. In the winter, upwelling off the West African coast delivers nutrients from deep waters to the ocean surface where the Sargassum grows.
"The evidence for nutrient enrichment is preliminary and based on limited field data and other environmental data, and we need more research to confirm this hypothesis," said Dr. Chuanmin Hu of the USF College of Marine Science, who led the study and has studied Sargassum using satellites since 2006. "On the other hand, based on the last 20 years of data, I can say that the belt is very likely to be a new normal," said Hu.
This article had great visual aids explaining the recent increase in sargassum blooms for the tropical Atlantic Ocean. After reading it one can take a way that the increase use of fertilizers has intensified and increased eutrophication of our coastal watersheds.
The team will now be testing primates, before potentially moving on to humans. Testing primates will help the research as humans and primates share closer similarities to that of humans and mice.
Hopeful, the researchers are looking to be granted approval for a human clinical trial by the Food and Drug Administration. If all works out, could start as early as mid-2020.
As Gendelman positively stated, "We are at the cusp of a scientific revolution in human genomes that can change the course, quality of life, and longevity of life."
Elimination of HIV-1 requires clearance and removal of integrated proviral DNA from infected cells and tissues. Here, sequential long-acting slow-effective release antiviral therapy (LASER ART) and CRISPR-Cas9 demonstrate viral clearance in latent infectious reservoirs in HIV-1 infected humanized mice. HIV-1 subgenomic DNA fragments, spanning the long terminal repeats and the Gag gene, are excised in vivo, resulting in elimination of integrated proviral DNA; virus is not detected in blood, lymphoid tissue, bone marrow and brain by nested and digital-droplet PCR as well as RNAscope tests. No CRISPR-Cas9 mediated off-target effects are detected. Adoptive transfer of human immunocytes from dual treated, virus-free animals to uninfected humanized mice fails to produce infectious progeny virus. In contrast, HIV-1 is readily detected following sole LASER ART or CRISPR-Cas9 treatment.
These data provide proof-of-concept that permanent viral elimination is possible.
Long ago, during the European Renaissance, Leonardo da Vinci wrote that we humans “know more about the movement of celestial bodies than about the soil underfoot.” Five hundred years and innumerable technological and scientific advances later, his sentiment still holds true. But that could soon change. A new study in Nature Communications details how an improved method for studying microbes in the soil will help scientists understand both fine-grained details and large-scale cycles of the environment.
Long ago, during the European Renaissance, Leonardo da Vinci wrote that we humans “know more about the movement of celestial bodies than about the soil underfoot.” Five hundred years and innumerable technological and scientific advances later, his sentiment still holds true. But that could soon change.
In a report published in Nature Communications, a team of scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) detailed the first-ever successful use of a technique called BONCAT to isolate active microbes present in a sample of soil – an achievement that could enable a tidal wave of new research.
“Soils are probably the most diverse microbial communities on the planet,” said Estelle Couradeau, first author of the study. “In every gram of soil, there are billions of cells from tens of thousands of species that, all together, perform important Earth nutrient cycles. They are the backbone of terrestrial ecosystems, and healthy soil microbiomes are key to sustainable agriculture. We now have the tools to see who these species are, but we don’t yet know how they do what they do. This proof-of-concept study shows that BONCAT is an effective tool that we could use to link active microbes to environmental processes.”
For the past two years, Couradeau, her co-authors, and many other researchers from around the U.S. have been collaborating in a Berkeley Lab-led scientific focus area called ENIGMA (for Ecosystems and Networks Integrated with Genes and Molecular Assemblies) in order to dig deeper into the inner-workings of soil microbiomes. ENIGMA’s projects are a high priority for biologists and energy and Earth scientists not only because they help fill gaps in our knowledge of how the environment functions, but also because these fundamental insights could help applied scientists more effectively harness microbiomes to improve drought-resistance in crops, remove contaminants from the environment, and sustainably produce fuels and other bioproducts.
Charles Paradis, now a post-doctoral researcher at Los Alamos National Laboratory, holds a soil core sample taken from the Oak Ridge Field Research Site in Tennessee. The BONCAT+FACS optimization testing reported in the current study used samples such as this one. (Credit: Lance E. King/Y-12 National Security Complex) However, because most soil microbes won’t grow in cultures in a laboratory, and because of their truly mind-boggling abundance in their natural habitats, investigating which microbial species do what is incredibly difficult. “There are many barriers to measuring microbial activities and interactions,” said Trent Northen, lead author and director of biotechnology for ENIGMA. “For example, soil microbiomes that remove waste from underground water reservoirs are found hundreds of feet below the surface. And in some ecosystems, up to 95% of the microbes are inactive at any given time.”
Because direct observation is off the table, microbiologists typically collect environmental samples and rely on indirect approaches such as DNA sequencing to characterize the communities. However, most of the commonly used techniques fail to differentiate active microbes from those that are dormant or from the plethora of free-floating bits of DNA found in soil and sediment.
BONCAT, short for Bioorthogonal Non-Canonical Amino Acid Tagging, was invented by Caltech geneticists in 2006 as a way to isolate newly made proteins in cells. In 2014, Rex Malmstrom, Danielle Goudeau, and others at the U.S. Department of Energy (DOE) Joint Genome Institute(JGI), a DOE Office of Science user facility managed by Berkeley Lab, collaborated with Victoria Orphan’s lab at Caltech to adapt BONCAT into a tool that could identify active, symbiotic clusters of dozens to hundreds of marine microbes within ocean sediment. After further refining their approach, called BONCAT Fluorescent Activated Cell Sorting (BONCAT+FACS), they were able to detect individual active microbes.
As the name suggests, BONCAT+FACS allows scientists to sort single-cell organisms based on the presence or absence of fluorescent tagging molecules, which bind to a modified version of the amino acid methionine. When fluid containing the modified methionine is introduced to a sample of microbes, only those that are creating new proteins – the hallmark of activity – will incorporate the modified methionine into cells. In addition to being far more streamlined and reliable than previous methods of microbial identification, the entire process takes just a few hours – meaning it can tag active cells even if they are not replicating.
Given that some soil microbes are notoriously slow-growing, many scientists were immediately interested in applying BONCAT+FACS to terrestrial soils. After three months of experimentation and optimization, the team of ENIGMA and JGI researchers devised a protocol that works smoothly and, most importantly, gives very reproducible results. “BONCAT+FACS is a powerful tool that provides a more refined method to determine which microbes are active in a community at any particular time,” said Malmstrom, who is also an author of the current study. “It also opens the door for us to experiment, to assess which cells are active under condition A and which cells become active or inactive when switched to condition B.”
Galaxy clusters are some of the most massive structures in the cosmos, but despite being millions of lightyears across, they can still be hard to spot. Researchers at Lancaster University have turned to artificial intelligence for assistance, developing "Deep-CEE" (Deep Learning for Galaxy Cluster Extraction and Evaluation), a novel deep learning technique to speed up the process of finding them. Matthew Chan, a Ph.D. student at Lancaster University, is presenting this work at the Royal Astronomical Society's National Astronomy meeting on 4 July at 3:45pm in the Machine Learning in Astrophysics session.
Most galaxies in the universe live in low-density environments known as "the field", or in small groups, like the one that contains our Milky Way and Andromeda. Galaxy clusters are rarer, but they represent the most extreme environments that galaxies can live in and studying them can help us better understand dark matter and dark energy.
During 1950s the pioneer of galaxy cluster-finding, astronomer George Abell, spent many years searching for galaxy clusters by eye, using a magnifying lens and photographic plates to locate them. Abell manually analysed around 2,000 photographic plates, looking for visual signatures the of galaxy clusters, and detailing the astronomical coordinates of the dense regions of galaxies. His work resulted in the 'Abell catalogue' of galaxy clusters found in the northern hemisphere.
Deep-CEE builds on Abell's approach for identifying galaxy clusters but replaces the astronomer with an AI model that has been trained to "look" at colour images and identify galaxy clusters. It is a state-of-the-art model based on neural networks, which are designed to mimic the way a human brain learns to recognise objects by activating specific neurons when visualizing distinctive patterns and colours.
Chan trained the AI by repeatedly showing it examples of known, labelled, objects in images until the algorithm is able to learn to associate objects on its own. Then ran a pilot study to test the algorithm's ability to identify and classify galaxy clusters in images that contain many other astronomical objects.
Even if we study them at school, oxidation numbers have so far eluded any rigorous quantum mechanical definition. A new SISSA study, published in Nature Physics, provides such a definition, based on the theory of topological quantum numbers, honored with the 2016 Nobel prize in Physics. This result paves the way to an accurate, yet tractable, numerical simulation of a broad class of materials that are important in energy-related technologies and planetary sciences.
Every undergraduate student in the natural sciences learns how to associate an integer oxidation number to a chemical species participating in a reaction. Unfortunately, the very concept of oxidation state has thus far eluded a rigorous quantum mechanical definition, so that no method was known until now to compute oxidation numbers from the fundamental laws of nature, let alone demonstrate that their use in the simulation of charge transport does not spoil the quality of numerical simulations. At the same time, the evaluation of electric currents in ionic conductors, which is required to model their transport properties, is presently based on a cumbersome quantum-mechanical approach that severely limits the feasibility of large-scale computer simulations. Scientists have lately noticed that a simplified model where each atom carries a charge equal to its oxidation number may give results in surprising good agreement with rigorous but much more expensive approaches.
By combining the new topological definition of oxidation number with the so-called "gauge invariance" of transport coefficients, recently discovered at SISSA, Federico Grasselli and Stefano Baroni proved that what was considered a mere coincidence stands in fact on solid theoretical grounds, and that the simple integer-charge model captures the electrical transport properties of ionic conductors without any approximations.
Besides solving a fundamental conundrum in condensed matter physics, this result, achieved within the framework of the European MAX Centre of Excellence for supercomputing applications, also represents a breakthrough for applications, enabling computationally feasible quantum simulations of charge transport in ionic systems of paramount importance in energy-related technologies, in the automotive and telecommunications sectors, as well as in planetary sciences. Such applications range from the ionic mixtures adopted in electrolytic cells and heat exchangers in power plants, to solid-state-electrolyte batteries for electric cars and electronic devices, and even to the conducting exotic phases of water occurring in the interior of icy giants, which are supposed to be related to the origin of the magnetic fields in these planets.
Cell death is a highly organized fundamental activity that is equally complex in regulation as cell division and differentiation. In the physiologic contexts of embryonic development and tissue renewal, or as a pathologic response to cell injury and infectious pathogens, cell deaths are orchestrated for multiple purposes that benefit the organism. These include maintenance of epithelial barrier function, destruction of microbes, adaptive immune responses, recycling of biologic macromolecules, intracellular signaling, and preservation of genomic integrity. The majority of mammalian cell deaths have morphologic and biochemical features of apoptosis, a self-inflicted death program encoded in the genetic material of all cells. Necrosis, on the other hand, an alternative mechanism of cell death, occurs in the aftermath of extreme cellular insults and could be viewed as a failure of cellular homeostasis. Recently, a programmed pathway of necrosis, referred to as necroptosis, has also been identified. Although cells contain their own death apparatus, cell death in multicellular organisms is exquisitely sensitive to the consent of neighboring cells.
As one might have expected, the internal cell death machinery is tightly interwoven with other essential cell pathways. Investigations of cell death have also fostered our understanding of living cells; for example, the recognition that cellular remodeling shares some pathways with apoptotic cell death.
Necrosis is an uncontrolled form of cell death that occurs in response to ischemia and other injuries. In necrosis the plasma membrane is disrupted allowing the cell contents to enter the extracellular space where they induce the influx of neutrophils, macrophages, and other elements of an acute inflammatory response.
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