The Protein Helping To Explain Foot-and-mouth’s Infectiousness (Biology)

Scientists have conducted a ‘molecular dissection’ of a part of the virus that causes foot-and-mouth disease, to try and understand why the pathogen is so infectious.

Top image: Pixabay

Foot-and-mouth disease is a highly contagious infection of cloven-hoofed animals which affects agricultural production and herd fertility. Global economic losses due to the disease have been estimated at between $6.5 billion and $22.5 billion each year, with the world’s poorest farmers hardest hit.  

A team of scientists from the Leeds and the University of Ilorin, in Nigeria, has investigated the significance of the unusual way the virus’s genome – or genetic blueprint – codes for the manufacture of a protein called 3B.  The protein is involved in the replication of the virus. 

Researchers have known for some time that the virus’ genetic blueprint contains three separate codes or instructions for the manufacture of 3B. Each code produces a similar but not identical copy of 3B. Up to now, scientists have not been able to explain the significance of having three different forms of the protein. 

In a paper, “Functional advantages of triplication of the 3B coding region of the FMDV genome“, published in The Federation of American Societies for Experimental Biology Journal, the Leeds researchers reveal the results of a series of laboratory experiments which has demonstrated that having multiple forms of 3B gives the virus a competitive advantage, increasing its chances of survival.  

Dr Oluwapelumi Adeyemi, formerly a researcher at Leeds and now with the University of Ilorin and one of the paper’s lead authors, said: “Our experiments have shown that having three forms of 3B gives the virus an advantage and that probably plays a role in why the virus is so successful in infecting its hosts. 

“It is not as straightforward as saying because there are three forms of 3B – it is going to be three times as competitive. There is a more nuanced interplay going on which needs further investigation.” 

The paper describes how the scientists manipulated the genetic code, creating viral fragments with one form of 3B, two different forms of 3B and all three forms of 3B. Each was then measured to see how well they replicated.  

They found there was a competitive advantage – greater replication – in those samples that had more than one copy of 3B. 

Dr Joe Ward, post-doctoral researcher at Leeds’ School of Molecular and Cellular Biology and the Astbury Centre for Structural Molecular Biology, and second co-lead author of the study, added: “The results of the data analysis were clear in that having multiple copies of the 3B protein gives the virus a competitive advantage. In terms of future research, the focus will be on why is that the case, and how the virus uses these multiple copies to its advantage.

“If we can begin to answer that question, then there is a real possibility we will identify interventions that could control this virus.”

The study involved using harmless viral fragments and replicons, fragments of RNA molecules, the chemical that make up the virus’s genetic code. 

The study was funded by the Biotechnology and Biological Sciences Research Council and the Global Challenges Research Fund.

References: Adeyemi, OO, Ward, JC, Snowden, JS, Herod, MR, Rowlands, DJ, Stonehouse, NJ. Functional advantages of triplication of the 3B coding region of the FMDV genome. The FASEB Journal. 2020; 00: 1– 14. https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202001473RR https://doi.org/10.1096/fj.202001473RR

Provided by University of Leeds

Can Dogs Smell COVID? Here’s What The Science Says (Neuroscience)

Canines seem to detect coronavirus infections with remarkable accuracy, but researchers say large-scale studies are needed before the approach is scaled up.

Asher is an eccentric, Storm likes sunbathing and Maple loves to use her brain. All three could play a part in controlling the COVID-19 pandemic, but they are not scientists or politicians. They are dogs.

Research groups around the world are testing whether dogs can detect COVID-19 by smell.Credit: Fatemeh Bahrami/Anadolu Agency/Getty

And they are not alone. Around the world, canines are being trained to detect the whiff of COVID-19 infections. Dog trainers are claiming extraordinary results — in some cases, they say that dogs can detect the virus with almost perfect accuracy. Scientists involved with the efforts suggest that canines could help to control the pandemic because they can screen hundreds of people an hour in busy places such as airports or sports stadiums, and are cheaper to run than conventional testing methods such as the RNA-amplification technique PCR.

But most of these findings have not yet been peer reviewed or published, making it hard for the wider scientific community to evaluate the claims. Researchers working on more conventional viral tests say that initial results from dog groups are intriguing and show promise. But some question whether the process can be scaled up to a level that would allow the animals to make a meaningful impact.

On 3 November, groups working with the animals met in an online workshop called International K9 Team to share preliminary results from experiments and to improve how their research is coordinated.

“No one is saying they can replace a PCR machine, but they could be very promising,” says veterinary neurologist Holger Volk at the University of Veterinary Medicine Hanover in Germany, who is leading an effort to train and study COVID-sniffing dogs and did not speak at the event.

Sense of wonder

Humans have taken advantage of canines’ superior sense of smell for decades. Dogs’ noses bear 300 million scent receptors, compared with humans’ 5 million or 6 million. That enables them to detect tiny concentrations of odour that people can’t. Sniffer dogs are already a familiar sight in airports, where they detect firearms, explosives and drugs. Scientists have also trained dogs to detect some cancers and malaria, but the animals are not routinely used for this purpose. Researchers don’t know for sure what the dogs are smelling, but many suspect that these illnesses cause the human body to let off a distinct pattern of volatile organic compounds (VOCs). These molecules readily evaporate to create scent that dogs can pick up. Previous work with non-COVID viruses has suggested that viral infections might also cause the body to do this.

Many sniffer-dog scientists turned their attention to COVID-19 early in the pandemic. They have trained their canines to smell samples, most often of sweat, in sterile containers, and to sit or paw the floor when they detect signs of infection. Trials at airports in the United Arab Emirates, Finland and Lebanon are using dogs to detect COVID-19 in sweat samples from passengers; these are then checked against conventional tests. According to data presented at the K9 meeting, dogs in Finland and Lebanon have identified cases days before conventional tests picked up the virus, suggesting that they can spot infection before symptoms start.

Riad Sarkis, a surgeon and researcher at Saint Joseph University in Beirut, is part of a French–Lebanese project that has trained 18 dogs. Sarkis used the best two performers for the airport trial in Lebanon. The dogs screened 1,680 passengers and found 158 COVID-19 cases that were confirmed by PCR tests. The animals correctly identified negative results with 100% accuracy, and correctly detected 92% of positive cases, according to unpublished results. “This is very accurate, feasible, cheap and reproducible,” says Sarkis, who has been approached about using the dogs in schools, banks and prisons, and is working with a shopping mall to offer COVID-19 testing using the animals.

Low-income countries with limited lab space could particularly benefit from the approach, says Isabella Eckerle, a virologist at the University Hospitals of Geneva in Switzerland.

Sample sizes

But there is just one published journal article on dogs’ efficacy at sniffing out COVID-19, by Volk’s group; he describes it as a pilot study1. The researchers trained eight dogs on samples taken from the mouths and windpipes of seven people hospitalized with COVID-19 and seven uninfected people. The dogs identified 83% of positive cases and 96% of negative ones.

The false positive and negative rates of the standard PCR lab test vary depending on the brand of test used and the timing of the test. A systematic review published as a preprint2 on medRxiv found the false-negative rate of RT-PCR tests to be 2–33% if the same sample is tested repeated times.Up to 4% of UK PCR test results could be false positives, according to government documents.

Critics say the German dog study used samples from too few patients. The dogs could be learning to identify the specific scent of the samples rather than of COVID-19, says Cynthia Otto, who leads the Penn Vet Working Dog Centre at the University of Pennsylvania in Philadelphia and is also working with COVID-19 sniffer dogs.

In her work, which is also unpublished, she has found that the dogs can tell the difference between samples of either urine or sweat from people with COVID-19 and those from people without the disease. She is working with chemists to understand which VOCs the dogs are picking up; a paper describing this is under review. “The dogs can do it. The challenge is the ignorance that we have as humans as to what can confuse the dogs,” she says. And in an effort to gather a large data set, her team is collecting sweat samples from 1,000 T-shirts worn overnight by people who have tested positive and negative for COVID-19.

A group in France, led by veterinary scientist Dominique Grandjean at the National Veterinary School of Alfort near Paris, posted its work3 on the preprint server bioRxiv in June. The researchers, who included Sarkis, trained 8 dogs to detect COVID-19 in 198 sweat samples, around half of which were from people with the disease. When these were hidden in a row of negative samples, the dogs identified the positive samples 83–100% of the time. The paper does not say how well the dogs identified negative test results. The research is now under review at a journal, but Grandjean says the process has not been easy. “To publish papers on detection dogs is very difficult because most reviewers do not know anything about working dogs,” he says.

The data in that study look promising, says Fyodor Urnov, a gene-editing scientist who is working on COVID testing at the University of California, Berkeley. But he would like to see larger data sets on how well dogs identify positive and negative samples. He also notes that there is variation in how well individual dogs perform. In Grandjean’s study, for example, 2 dogs identified 68 out of 68 positive samples, whereas one missed 10 out of 57 cases.

Groups need to boost their sample sizes before the wider scientific community can evaluate how useful the dogs might be, agrees James Logan, an infectious-disease researcher at the London School of Hygiene & Tropical Medicine who is training and studying COVID-19 dogs, including Storm, Maple and Asher. “It’s important not to go out too early with grand claims and small data sets,” he says.

References: Holger Volk, James Logan et al., “Can dogs smell COVID? Here’s what the science says”, Nature 587, 530-531 (2020). doi: https://doi.org/10.1038/d41586-020-03149-9

Provided by Nature

3 Questions: Using Fabric to “Listen” To Space Dust (Planetary Science)

Fabric samples are headed to the International Space Station for resiliency testing; possible applications include cosmic dust detectors or spacesuit smart skins.

Earlier this month a team of MIT researchers sent samples of various high-tech fabrics, some with embedded sensors or electronics, to the International Space Station. The samples (unpowered for now) will be exposed to the space environment for a year in order to determine a baseline for how well these materials survive the harsh environment of low Earth orbit.

A team of MIT researchers has sent a panel of passive smart fabric samples to the International Space Station for a year to help determine how well these fabrics survive low Earth orbit.
Credits: Image: JAXA/Space and edited by MIT News

The hope is that this work could lead to thermal blankets for spacecraft, that could act as sensitive detectors for impacting micrometeoroids and space debris. Ultimately, another goal is new smart fabrics that allow astronauts to feel touch right through their pressurized suits.

Three members of MIT’s multidisciplinary team, graduate students Juliana Cherston of the Media Lab, Yuchen Sun of the Department of Chemistry, and Wei Yan of the Research Laboratory of Electronics and the Department of Materials Science and Engineering, discussed the experiment’s ambitious aims with MIT News.

Q:​ Can you describe the fabric samples that you sent to the International Space Station, and what kinds of information you are hoping to get from them after their exposure in space?

Cherston: The white color of the International Space Station is actually a protective fabric material called Beta cloth, which is a Teflon-impregnated fiberglass designed to shield spacecraft and spacesuits from the harsh elements of low Earth orbit. For decades, these fabrics have remained electrically passive, despite offering large-area real estate on the exterior of space assets.

We imagine turning this spacecraft skin into an enormous space debris and micrometeoroid impact sensor. The samples that we worked with JAXA, the Japanese space agency, and Space BD to send to the International Space Station incorporate materials like charge-sensitive synthetic fur — an early concept — and vibration-sensitive fiber sensors — our project’s focus — into space-resilient fabrics. The resulting fabric may be useful for detecting cosmic dust of scientific interest, and for damage detection on spacecraft. 

It’s easy to assume that since we’re already sending these materials to space, the technology must be very mature. In reality, we are leveraging the space environment  to complement our important ground-testing efforts. All of these fabric sensors will remain unpowered for this first in-space test, and the quilt of samples occupies a total area of 10 by 10 centimeters on the exterior walls of the station.

Our focus is on baselining their resiliency to the space environment. In one year, these samples will return to Earth for postflight analysis. We’ll be able to measure any erosion from atomic oxygen, discoloration from UV radiation, and any changes to fiber sensor performance after one year of thermal cycling. There is some chance that we will also find hints of micron-scale micrometeoroids. We’re also already preparing for an electrically powered deployment currently scheduled for late 2021 or early 2022 (recently awarded to the project by the ISS National Lab). At that point we’ll apply an additional protective coating to the fibers and actually operate them in space.

Yan: The fabric samples contain thermally drawn “acoustic” fibers developed with ISN funding that are capable of converting mechanical vibration energy into electric energy (via the piezoelectric effect). When micrometeoroids or space debris hit the fabric, the fabric vibrates, and the “acoustic” fiber generates an electrical signal. Thermally drawn multimaterial fibers have been developed by our research group at MIT for more than 20 years; what makes these acoustic fibers special is their exquisite sensitivity to mechanical vibrations. The fabric has been shown in ground facilities to detect and measure impact regardless of where the space dust impacted the surface of the fabric.

Q: What is the ultimate goal of the project? What kinds of uses do you foresee for advanced fabrics in the space environment?

Cherston: I am particularly keen to demonstrate that instrumentation useful for fundamental scientific inquiry can be incorporated directly into the fabric skin of persistent spacecraft, which to date is unused and very precious real estate. In particular, I am beginning to evaluate whether these skins are sensitive enough to detect cosmic dust produced in million-year-old supernova explosions tens or hundreds of light-years away from Earth. Just last year, an isotopic signature for this type of interstellar dust was discovered in fresh Antarctic snow, so we believe that some of this dust is still whizzing around the solar system, holding clues about the dynamics of supernova explosions. In-situ characterization of their distribution and kinematics is currently my most ambitious scientific goal.

More generally, I’d love to see advanced fibers and fabrics tackle other questions of fundamental physical interest in space, maybe by leveraging optical fibers or radiation sensitive materials to create large aperture sensors.

Some students in my group have also developed a conceptual prototype in which sensory data on the exterior skin of a pressurized spacesuit armband is mapped to haptic actuators on the wearer’s biological skin. Using this system, astronauts will be able to feel texture and touch right through their spacesuits! This direct experience of a new environment is very central to humanity’s drive to explore.

An impact-sensitive skin can also be used for damage detection on persistent space craft. In practice, the fabric’s ability to localize damage from space debris and micrometeoroids is how we will really sell the concept to aerospace engineers.

Yan: Although the space age began 63 years ago when Soviet Union’s Sputnik 1 was launched into an elliptical low Earth orbit, many unanswered questions remain regarding the effect of the space environment on humans, as well as the safety of astronauts as they operate in the space environment. While our project’s main focus has been on augmenting fabrics used on the exterior of spacecraft, I also envision that future spacesuits will be electrically active and highly multifunctional.

Textiles buried within the suit will be able monitor the health condition of astronauts in real time by interrogating physiological signals over large areas. Fabrics may also serve as  localized heating and cooling systems, radiation dosimeters, and efficient communications infrastructure (via fabric optics and acoustics). They may harvest solar energy as well as small amounts of energy from vibration, and store this energy in fiber batteries or supercapacitors, which would allow the system to be self-powered. Fabrics might even serve as part of an exoskeleton that assists astronauts in maneuvering on planetary bodies and in microgravity.One broad vision at play is to pack an enormous amount of function into space resilient textiles, creating an analogue of “Moore’s law” for space fabrics.

​​​Q: What got you interested in this subject, and what has this experience been like for you in getting the materials ready to be sent into space?

Yan: Space is definitely a new frontier for our research, while lots of terrestrial applications have been envisioned in ambient conditions and even under water. From low Earth orbit to planetary bodies, space is a unique environment with atomic oxygen, radiation, high speed impactors, and extreme temperature cycling. How will the fibers and fabrics perform there and what changes will be induced in the fiber materials? How should electronic fabrics be designed in order to meet demands of aerospace applications? There are so many scientific and technological questions.

Sun: Our group [with professor of chemistry Keith Nelson] strives to push the limits of what is experimentally achievable for impact testing, and we are always excited by a new challenge. Recently, we have been venturing into the area of high-speed mechanics, testing novel materials spanning polymers, thin films, and nanoarchitected materials using a laser accelerator facility designed by our lab to impinge tiny particles on target surfaces at speeds exceeding 1 kilometer per second.

When the idea emerged to test a material capable of detecting impact signatures in low Earth orbit and beyond, there was immediate interest on our side since it is fundamentally different from our previous research focus. These experiments are certainly more difficult and complex than what we are used to, with many more active parts to maintain. I think we were all quite pleasantly surprised when our preliminary impact experiments were successful and encouraging.

Cherston: While space launches are exciting, in reality some of our most convincing data to date has come from impact testing on the ground. Initially, it was not at all obvious that a fabric sensor with sparsely integrated sensing elements could actually detect such small and fast particles. There were a really great few minutes at our first serious impact testing campaign during which Yuchen gradually increased the number of particles accelerated onto our sensor, while holding all other aspects of the experiment constant. The growing signal was a smoking gun indication that we were seeing a true impact signature. 

On a personal level, I’m really fascinated by the idea of leveraging very unconventional technology like fabric for questions of scientific significance. And I think the idea of feeling right through a pressurized spacesuit is delightful!

References: Juliana Cherston, David Veysset, Yuchen Sun, Hajime Yano, Keith A. Nelson, Shobha Murari, Joseph A. Paradiso, “Large-area electronic skins in space: vision and preflight characterization for first aerospace piezoelectric E-textile”, Proceedings Volume 11379, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2020; 113791Q (2020) https://resenv.media.mit.edu/pubs/papers/SpaceSkin_Submitted.pdf https://doi.org/10.1117/12.2557942

Provided by MIT

Catch Monday Morning’s Subtle Lunar Eclipse (Planetary Science)

A penumbral lunar eclipse in the early morning hours of November 30th marks the start of the last eclipse season for 2020.

Howling at the Moon Sunday night? Sunday night into Monday morning November 30th features not only the penultimate Full Moon for 2020, but the final lunar eclipse of the year, with a penumbral eclipse of the Moon.

The Moon vs. the shadow of the Earth during Monday morning’s eclipse. Adapted from NASA/GSFC/F. Espenak graphic

The eclipse is a subtle penumbral eclipse, the fourth and final of four such eclipses in 2020 and the final lunar eclipse for the decade. The Moon won’t turn blood-red like during a total lunar eclipse: at most, expect a fine tea-colored shading to drape to Moon, with perhaps a ragged discoloration on the northwestern limb of the Moon near mid-eclipse.

The eclipse is visible in its entirety from North America, while South America sees the eclipse in progress at sunrise/moonset, and eastern Asia and Australia sees the eclipse underway at sunset/moonrise. Hawaii gets the very best view, with the eclipsed Moon very near the zenith.

Times for the eclipse are:

-The Moon starts to enter the penumbral shadow of the Earth (P1) at 7:32 Universal Time (UT)/2:32 AM Eastern Standard Time (EST) on Monday, November 30th.

-Mid-eclipse occurs at 9:44 UT/4:44 AM EST.

-The Moon exits the Earth’s penumbral shadow (P4) at 11:53 UT/6:53 AM EST.

The visibility footprint for Monday’s eclipse. Credit: NASA/GSFC/Fred Espenak

The entire eclipse lasts 4 hours and 21 minutes… but the best time to take a look and see perhaps a light shading on the Moon is around mid-eclipse, when the Moon is 83% immersed in the penumbra of the Earth. The Moon juuuuust misses the inner dark umbra of the Earth’s shadow by less than 10’ arcminutes.

This eclipse also marks the start of the final eclipse season for 2020. If the orbit of the Moon was aligned with the ecliptic flight of the Earth around the Sun, we would see an eclipse every 29.5 day synodic period: one lunar and one solar eclipse at Full and New Moon, respectively. Since the orbit of the Moon is tilted just over five degrees relative to the ecliptic, we have to wait until the intersection nodes are lined up for an eclipse season to occur, something that happens roughly twice a year. This also means that eclipses occur in lunar-solar pairs. In the case of the upcoming eclipse season, Monday’s penumbral lunar eclipse is followed by a total solar eclipse spanning the southern tip of South America on December 14th.

Tales of the Saros

What’s more, lunar and solar eclipses are members of larger 18 year, 11 day and 8 hour-long period known as a saros. This works out because 223 synodic lunations (the period of time it takes the Moon to return to like phase, i.e. Full-to-full or New-to-New) very nearly equals a saros. This also means that successive eclipses with very similar circumstances occur one saros apart, with the visibility path shifted 120 degrees in longitude westward. Several saroses—both lunar and solar—are in play on any given year. In the case of Monday’s penumbral, this eclipse is member 58 of 73 eclipses in lunar saros series 116, which started in 933 AD on March 11th, and runs all the way out to 2291. Saros 116 also produced its last total lunar eclipse on July 11th, 1786 and is now on its way out the door, with a final shallow penumbral eclipse occurring on May 14, 2291.

Why do penumbrals occur? Why doesn’t the Earth cast one distinct, sharp shadow out into space? This dual shadow has to do with the nature of light, and the fact that the Sun isn’t a point source: it’s actually visually very nearly the apparent size of of the Moon as seen from the Earth, as witnessed during a total solar eclipse. You see this secondary shadow effect daily, in places like a room lit only from a window off to one side: once you know to look for them, penumbral shadows are literally everywhere.

Here’s another way to think of it: when you’re witnessing a partial solar eclipse, you’re also in the penumbral shadow of the Moon. Likewise, standing on the nearside of the Moon on Monday morning and looking back at the Earth (with proper eye protection, of course), you would see a partial solar eclipse.

Monday’s eclipse… as seen from the Moon. Credit: Stellarium

Turn’s out, a newcomer will indeed be on the Moon, assuming it lands successfully: China’s Chang’e 5 sample return mission, set to land at Mon Rümker in the Oceanus Procellarum region this weekend. There’s no word if the team is planning on imaging the partial solar eclipse (or even has to capability to do so) but this possible view from the surface of the Moon would be a first.

Here’s a fun naked eye observation to carry out during a penumbral eclipse: take a close at the Full Moon right near mid- ‘penumbralarity…’ would you notice something was afoot, if you didn’t know better? Can you spy the ragged edge of the umbra, trying in vain to gobble up the Moon? Perhaps a lux or color meter (common on many smartphones these days) might sense the slight difference in brightness and tint during a penumbral eclipse.

A more straight-forward way to ‘see’ the eclipse is to simply image the Moon before, during and after the eclipse, using the exact same camera and settings… does the mid-eclipse photo look noticeably different to you?

Fear not: the total lunar eclipse drought is almost over. While 2021 features only four eclipses (the minimum that occur on a calendar year, which must be 2 lunar and 2 solar) we do indeed have a total lunar eclipse on May 26th, favoring the Pacific Rim region.

If skies are clear, be sure to set your alarm for the ‘penultimate penumbral eclipse,” of 2020.

This article is republished here from universe today under common creative licenses.

A Hint Of New Physics In Polarized Radiation From the Early Universe (Astronomy)

Using Planck data from the cosmic microwave background radiation, an international team of researchers has observed a hint of new physics. The team developed a new method to measure the polarization angle of the ancient light by calibrating it with dust emission from our own Milky Way. While the signal is not detected with enough precision to draw definite conclusions, it may suggest that dark matter or dark energy causes a violation of the so-called “parity symmetry.”

Figure: As the light of the cosmic microwave background emitted 13.8 billion years ago (left image) travels through the Universe until observed on Earth (right image), the direction in which the electromagnetic wave oscillates (orange line) is rotated by an angle β. The rotation could be caused by dark matter or dark energy interacting with the light of the cosmic microwave background, which changes the patterns of polarization (black lines inside the images). The red and blue regions in the images show hot and cold regions of the cosmic microwave background, respectively. (Credit: Y. Minami / KEK)

The laws of physics governing the Universe are thought not to change when flipped around in a mirror. For example, electromagnetism works the same regardless of whether you are in the original system, or in a mirrored system in which all spatial coordinates have been flipped. If this symmetry, called “parity,” is violated, it may hold the key to understanding the elusive nature of dark matter and dark energy, which occupy 25 and 70 percent of the energy budget of the Universe today, respectively. While both dark, these two components have opposite effects on the evolution of the Universe: dark matter attracts, while dark energy causes the Universe to expand ever faster.

A new study, including researchers from the Institute of Particle and Nuclear Studies (IPNS) at the High Energy Accelerator Research Organization (KEK), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) of the University of Tokyo, and the Max Planck Institute for Astrophysics (MPA), reports on a tantalizing hint of new physics—with 99.2 percent confidence level —which violates parity symmetry. Their findings were published in the journal Physical Review Letters on November 23, 2020; the paper was selected as the “Editors’ Suggestion,” judged by editors of the journal to be important, interesting, and well written.

The hint to a violation of parity symmetry was found in the cosmic microwave background radiation, the remnant light of the Big Bang. The key is the polarized light of the cosmic microwave background. Light is a propagating electromagnetic wave. When it consists of waves oscillating in a preferred direction, physicists call it “polarized.” The polarization arises when the light is scattered. Sunlight, for instance, consists of waves with all possible oscillating directions; thus, it is not polarized. The light of a rainbow, meanwhile, is polarized because the sunlight is scattered by water droplets in the atmosphere. Similarly, the light of the cosmic microwave background initially became polarized when scattered by electrons 400,000 years after the Big Bang. As this light traveled through the Universe for 13.8 billion years, the interaction of the cosmic microwave background with dark matter or dark energy could cause the plane of polarization to rotate by an angle β (Figure).

“If dark matter or dark energy interact with the light of the cosmic microwave background in a way that violates parity symmetry, we can find its signature in the polarization data,” points out Yuto Minami, a postdoctoral fellow at IPNS, KEK.

To measure the rotation angle β, the scientists needed polarization-sensitive detectors, such as those onboard the Planck satellite of the European Space Agency (ESA). And they needed to know how the polarization-sensitive detectors are oriented relative to the sky. If this information was not known with sufficient precision, the measured polarization plane would appear to be rotated artificially, creating a false signal. In the past, uncertainties over the artificial rotation introduced by the detectors themselves limited the measurement accuracy of the cosmic polarization angle β.

“We developed a new method to determine the artificial rotation using the polarized light emitted by dust in our Milky Way,” said Minami. “With this method, we have achieved a precision that is twice that of the previous work, and are finally able to measure β.” The distance traveled by the light from dust within the Milky Way is much shorter than that of the cosmic microwave background. This means that the dust emission is not affected by dark matter or dark energy, i.e. β is present only in the light of the cosmic microwave background, while the artificial rotation affects both. The difference in the measured polarization angle between both sources of light can thus be used to measure β.

The research team applied the new method to measure β from the polarization data taken by the Planck satellite. They found a hint for violation of parity symmetry with 99.2 percent confidence level. To claim a discovery of new physics, much greater statistical significance, or a confidence level of 99.99995 percent, is required. Eiichiro Komatsu, director at the MPA and Principal Investigator at the Kavli IPMU, said: “It is clear that we have not found definitive evidence for new physics yet; higher statistical significance is needed to confirm this signal. But we are excited because our new method finally allowed us to make this ‘impossible’ measurement, which may point to new physics.”

To confirm this signal, the new method can be applied to any of the existing— and future—experiments measuring polarization of the cosmic microwave background, such as Simons Array and LiteBIRD, in which both KEK and the Kavli IPMU are involved.

References: Yuto Minami, Eiichiro Komatsu, “New extraction of the cosmic birefringence from the Planck 2018 polarization data”, Phys. Rev. Lett. 125, 221301 – Published 23 November 2020. https://link.aps.org/doi/10.1103/PhysRevLett.125.221301 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.221301

Provided by KAVLI IMPU

Research Suggests Our Galaxy’s Brightest Gamma-ray Binary System May be Powered By A Magnetar Star (Astronomy)

A team of researchers led by members of the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) has analyzed previously collected data to infer the true nature of a compact object—found to be a rotating magnetar, a type of neutron star with an extremely strong magnetic field—orbiting within LS 5039, the brightest gamma-ray binary system in the Galaxy.

An impression of the gamma-ray binary system LS 5039. A neutron star (left) and its massive, companion star (right). The research team suggests that the neutron star at the heart of LS 5039 has an ultra-strong magnetic field, and is arguably a magnetar. The field accelerates high-energy particles inside the bow-shaped region, thereby emitting gamma-rays that characterize the gamma-ray binary system. (Credit: Kavli IPMU)

Including former graduate student Hiroki Yoneda, Senior Scientist Kazuo Makishima and Principal Investigator Tadayuki Takahashi at the Kavli IMPU, the team also suggest that the particle acceleration process known to occur within LS 5039 is caused by interactions between the dense stellar winds of its primary massive star, and ultra-strong magnetic fields of the rotating magnetar.

Gamma-ray binaries are a system of massive, high-energy stars and compact stars. They were discovered only recently, in 2004, when observations of very-high-energy gamma-rays in the teraelectronvolt (TeV) band from large enough regions of the sky became possible. When viewed with visible light, gamma-ray binaries appear as bright bluish-white stars, and are indistinguishable from any other binary system hosting a massive star. However, when observed with X-rays and gamma-rays, their properties are dramatically different from those of other binaries. In these energy bands, ordinary binary systems are completely invisible, but gamma-ray binaries produce intense non-thermal emission, and their intensity appears to increase and decrease according to their orbital periods of several days to several years.

Once the gamma-ray binaries were established as a new astrophysical class, it was quickly recognized that an extremely efficient acceleration mechanism should operate in them. While the acceleration of TeV particles requires tens of years in supernova remnants, which are renowned cosmic accelerators, gamma-ray binaries boost electron energy beyond 1 TeV in just tens of seconds. Gamma-ray binaries can thus be considered one of the most efficient particle accelerators in the Universe.

In addition, some gamma-ray binaries are known to emit strong gamma-rays with energies of several megaelectron volts (MeV). Gamma-rays in this band are currently difficult to observe; they were detected from only around 30 celestial bodies in the whole sky. But the fact that such binaries emit strong radiation even in this energy band greatly adds to the mystery surrounding them, and indicates an extremely effective particle acceleration process going on within them.

Around 10 gamma-ray binaries have been found in the Galaxy thus far—compared to more than 300 X-ray binaries that are known to exist. Why gamma-ray binaries are so rare is unknown, and, indeed, what the true nature of their acceleration mechanism is, has been a mystery—until now.

Through previous studies, it was already clear that a gamma-ray binary is generally made of a massive primary star that weighs 20-30 times the mass of the Sun, and a companion star that must be a compact star, but it was not clear, in many cases, whether the compact star is a black hole or a neutron star. The research team started their attempt by figuring out which is generally the case.

One of the most direct pieces of evidence for the presence of a neutron star is the detection of periodic fast pulsations, which are related to the neutron star rotation. Detection of such pulsation from a gamma-ray binary almost undoubtedly discards the black hole scenario.

In this project, the team focused on LS 5039, which was discovered in 2005, and still keep its position as the brightest gamma-ray binary in the X-rays and gamma-ray range. Indeed, this gamma-ray binary was thought to contain a neutron star because of its stable X-ray and TeV gamma-ray radiation. However, until now, attempts to detect such pulses had been conducted with radio waves and soft X-rays—and because radio waves and soft X-rays are affected by the primary star’s stellar winds, detection of such periodical pulses had not been successful.

This time, for the first time, the team focused on the hard X-ray band (>10 keV) and observation data from LS 5039 gathered by the hard X-ray detector (HXD) on board the space-based telescopes Suzaku (between September 9 and 15, 2007) and NuSTAR (between September 1 and 5, 2016)—indeed, the six-day Suzaku observation period was the longest yet using hard X-rays.

Both observations, while separated by nine years, provided evidence of a neutron star at the core of LS 5039: the periodic signal from Suzaku with a period of about 9 seconds. The probability that this signal arises from statistical fluctuations is only 0.1 percent. NuSTAR also showed a very similar pulse signal, though the pulse significance was lower—the NuSTAR data, for instance, was only tentative. By combining these results, it was also inferred that the spin period is increasing by 0.001 s every year.

Based on the derived spin period and the rate of its increase, the team ruled out the rotation-powered and accretion-powered scenarios, and found that the magnetic energy of the neutron star is the sole energy source that can power LS 5039. The required magnetic field reaches 1011 T, which is 3 orders of magnitude higher than those of typical neutron stars. This value is found among so-called magnetars, a subclass of neutron stars which have such an extremely strong magnetic field. The pulse period of 9 seconds is typical of magnetars, and this strong magnetic field prevents the stellar wind of the primary star from being captured by a neutron star, which can explain why LS 5039 does not exhibit properties similar to X-ray pulsars (X-ray pulsars usually occur in X-ray binary systems, where the stellar winds are captured by its companion star).

Interestingly, the 30 magnetars that have been found so far have all been found as isolated stars, so their existence in gamma-ray binaries was not considered a mainstream idea. Besides this new hypothesis, the team suggests a source that powers the non-thermal emission inside LS 5039—they propose that the emission is caused by an interaction between the magnetar’s magnetic fields and dense stellar winds. Indeed, their calculations suggest that gamma-rays with energies of several megaelectronvolts, which has been unclear, can be strongly emitted if they are produced in a region of an extremely strong magnetic field, close to a magnetar.

These results potentially settle the mystery as to the nature of the compact object within LS 5039, and the underlying mechanism powering the binary system. However, further observations and refining of their research is needed to shed new light on their findings.

References: Hiroki Yoneda, Kazuo Makishima, Teruaki Enoto, Dmitry Khangulyan, Takahiro Matsumoto, Tadayuki Takahashi, “Sign of hard X-ray pulsation from the gamma-ray binary system LS 5039”, Phys. Rev. Lett. 125, 111103 – Published 8 September 2020. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.111103

Provided by KAVLI IMPU

Scientists Claim Controversial Results Of Comets Observations Are Consistent (Planetary Science)

Astrophysicists from Far Eastern Federal University (FEFU) joined the international research team for explaining the difference in the results of observation of the comet 41P/ Tuttle – Giacobini – Kresak. Researchers believe that data obtained by three independent teams are complementary and its complex analysis helps to unravel the mystery of dust chemical composition of comet 41P and other conundrums of the Universe. A related article appears in Astronomy & Astrophysics.

Image of 41P/T-G-K obtained with the 70-cm AZT-8 telescope on observation station Lisnyky of the Astronomical Observatory of Taras Shevchenko National University of Kyiv (Ukraine) of 25 April 2017. ©FEFU press office

The activity of comets is more complex than it appeared to be, one of the research outcomes says. The chemical composition of a cometary coma (gas-dusty environment of the nucleus) is able to change very rapidly, literally during the day. That is because of the Sun affects the nucleus of a comet approaching.

Researchers all over the Globe try to get data on the chemical composition of comets via analyses of the light refracted by its dust particles. However, the information about the color spectrum of comets differs every time, depending on different observation epochs and different phase angles (angle Earth-comet-Sun).

The present research paper postulates the controversial data sets obtained due to different sets of photometric filters and areas (apertures) of research are steady.

“At least three groups of researchers who observed comet 41P in 2017 came up with different results. The comet color ranged from red to blue. We have explained in detail why this happened”, Anton Kochergin says”, one of the authors of the study, a young scientist at FEFU. “Usually, the final color is normalized by taking into account the different bandwidths of the photometric filters applied. However, in many studies, the color of celestial bodies is interpreted independently of a particular set of photometric filters. We show that this is not valid for all cases. The reason the comet color differs is exactly sets of various photometric filters. In addition, the choice of the size of the calculation area, i.e. aperture, is of great importance. This is a certain radius around the cometary coma in the pictures from observatories, which scientists define as an area of research. Having decided on the aperture, they analyze only the signal inside this field”.

The choice of the aperture determines which processes and results are included in the analysis. For example, a gas from a diatomic carbon molecule (C2): there are parent molecules (called CHON particles in the literature), which become a source of C2 upon photodissociation. This dissociation occurs at a certain distance from the comet’s nucleus, which in turn depends on the comet’s distance from the Sun. With the right aperture chosen, one can exclude most of the signals that C2 molecules give focusing on analyses of the dust component of the coma.

Dr. Kochergin emphasized that the opposite data about the color of the comet, collected by different groups using different sets of photometric filters, only benefits the researchers. It is impossible to give a thorough description of the color (the color is directly related to the chemical composition of the dust of a cometary coma), and the chemical composition after just one observation. It is necessary to observe and determine the characteristics in dynamics. The more measurements made, the more accurate the conclusions are.

“In practice, this allows us to probe into the microphysical properties of cometary dust, and the processes run in a cometary coma. With such information, we will shed light on the evolutionary processes of the Solar system. Many scientific groups around the world are working inside this fundamental area”, explains Anton Kochergin.

Scientists were able to model the results of color measurements of comet 41P, receives almost simultaneously via different photometric filters in different locations. Although the blue color was gained in one case and the red in the other, the researchers found that both results were consistent with the actual behavior of cometary dust particles in coma 41P. One can copy these results via simulating light scattering by dust particles of the pyroxene mineral. Pyroxene is a silicate material that is part of the lunar soil and was also delivered from the asteroid Itokawa and discovered in the comet 81P / Wild 2. Pyroxenes are a part of cometary matter and are well studied in laboratories.

Researchers to further cooperate in observing celestial bodies from different Earth locations. The routine helps to catch up with the object under investigation in case of adverse weather conditions at the location of one of the observatories. This also brings additional data in the case of different sets of filters applied by different teams. In the observation schedule of the international collaborators, all comets and asteroids their gear is capable of tracing.

The present results became possible due to the collaboration of scientists from Astronomical Observatory, Taras Shevchenko National University of Kyiv, Humanitas College, Kyung Hee University (South Korea), Space Science Institute (USA), Astronomical Institute of the Slovak Academy of Sciences, Main Astronomical Observatory of National Academy of Sciences, School of Natural Sciences, Far Eastern Federal University, Ussuriysk Observatory of the Institute of Applied Astronomy of the Russian Academy of Sciences.

Previously, FEFU astrophysicists teamed up with Russian and foreign colleagues to observe the ATLAS comet, which disintegrated when approaching the Sun. They brought up a conclusion that carbon found in the nucleus of the comet would help to determine the age of comets in the Solar system.

References: Igor Lukyanyk, Evgenij Zubko, Gorden Videen, Oleksandra Ivanova and Anton Kochergin, “Resolving color differences of comet 41P/Tuttle-Giacobini-Kresak”, A&A 642, L5 (2020). https://www.aanda.org/articles/aa/abs/2020/10/aa38893-20/aa38893-20.html

Provided by Far Eastern Federal University

Would Moving to a New City or Country Make You Happier? (Psychology)

New research examines geographical effects on people’s happiness.

A long-standing debate in the field of psychology has been whether moving to a new location makes people happier. One school of thought says yes. In fact, it may be exactly the type of “fresh start” people need to re-calibrate their happiness. Another suggests that while a move might provide us with a temporary lift in mood, it is most common for our happiness to return to its baseline, pre-move level.

©Pixlr

A new analysis provided in this year’s World Happiness Report adds context to this unsettled debate.

The authors of the report, led by a team of researchers at the Center for Sustainable Development at Columbia University, conducted an analysis dating back to 2018 in which they compared happiness levels among people who were natives of a given country versus immigrants/foreigners. The idea was to assess whether non-natives’ levels of happiness corresponded more closely to that of their home country or their adopted country.

Interestingly, they found that people who move to a new country shed their old country’s level of happiness and adopt their new country’s level: “We split the responses between the locally and foreign-born populations in each country, and found the happiness rankings to be essentially the same for the two groups, although with some footprint effect after migration, and some tendency for migrants to move to happier countries, so that among the 20 happiest countries in that report, the average happiness for the locally born was about 0.2 points higher than for the foreign-born.”

In other words, moving to a happier country could plausibly make you happier. By the same token, moving to a less happy country could reduce your level of happiness. And there’s nothing to suggest that the same pattern of results wouldn’t apply to cities as well. (Speaking of cities, the researchers found Helsinki, Finland; Aarhus, Denmark; and Wellington, New Zealand to be the happiest cities in the world, and Washington, Dallas, and Houston to be the three happiest cities in the United States.)

Three other insights are worth noting from the report:

1. The gap between the happiest and least happy countries is enormous. To measure worldwide happiness, the scientists used the following question: “Please imagine a ladder, with steps numbered from 0 at the bottom to 10 at the top. The top of the ladder represents the best possible life for you and the bottom of the ladder represents the worst possible life for you. On which step of the ladder would you say you personally feel you stand at this time?”

The gap between the happiest and least happy countries is massive. The top 10 happiest countries (Finland, Denmark, Switzerland, Iceland, Norway, the Netherlands, Sweden, New Zealand, Austria, and Luxembourg) scored an average of 7.5 on the life satisfaction question above. The bottom 10 (Afghanistan, South Sudan, Zimbabwe, Rwanda, Central African Republic, Tanzania, Botswana, Yemen, Malawi, and India) averaged 3.3.

Anyone who has experience with psychological scales will attest to the magnitude of this difference. A one- or two-point difference would be impressive here. The fact that there is a four-point difference between the top and bottom countries is simply staggering.

2. Smaller countries are getting happier; larger countries are not. Practically speaking, there are two ways to quantify worldwide happiness. One is to weight each country’s happiness to the proportion of the worldwide population it represents. Another is to treat each country as equal to all the others. Think of it as the House and Senate versions of the happiness equation.

When you compare these two perspectives over time, the proportioned data shows a decrease in worldwide happiness from 2014 to 2019, while the unproportioned data shows a modest increase.

This means one thing: Happiness levels are improving in smaller countries and worsening in larger ones. And even when you remove the largest five countries (China, India, the United States, Indonesia, and Brazil) from the analysis to avoid possible outlier effects, the trend remains.

3. Urbanites are happier than country folk, or at least they were prior to coronavirusThink back to a time before cities were ravaged by Covid-19: Were city-dwellers happier than country-folk? The answer is a resounding yes. The scientists calculated the happiness average for the worldwide urban population to be 5.48, compared to 5.07 for the worldwide rural population. The differences were largest in East Asia and Sub-Saharan Africa, followed by South Asia, Southern Europe, and Latin America and the Caribbean.

Only 13 of the 150 countries surveyed showed the opposite trend. Which showed the biggest reversal? Lebanon, Iceland, the Netherlands, New Zealand, the United Kingdom, and Egypt. So, if you’re a rural type and you’re considering a move, perhaps one of those countries should be on your shortlist.

References: Helliwell, John F., Richard Layard, Jeffrey Sachs, and Jan-Emmanuel De Neve, eds. 2020. World Happiness Report 2020. New York: Sustainable Development Solutions Network. https://worldhappiness.report/ed/2020/#read

This article is originally written by Mark Travers, who is a psychologist and is republished here from psychology today under common creative licenses.

‘Turncoat’ Macrophages in The Tumor ‘Micro-environment’ Underlie Breast Cancer Progression (Medicine)

New research that is examining the “tumor microenvironment” reveals not only how macrophages can become extraordinary turncoats but also how they can actively support tumor growth and metastatic progression in certain forms of breast cancer.

Macrophages ©gettyimages

The tumor microenvironment—or TME—refers to the region encompassing a tumor, an area entangled with blood vessels that feed the tumor, and aided by a support cast of immune cells, signaling molecules, fibroblasts, resident host cells, lymphatics, and an array of proteins. Macrophages in the tumor microenvironment aren’t the faithful soldiers of the immune system gobbling up invaders. Instead, they’re shady traitors that aid and abet the enemy—cancer.

Tumors of all kinds actively engage with their microenvironment, a factor that strongly influences tumor progression and metastasis. A growing body of evidence suggests that triple negative breast cancer is among the forms of the disease that may benefit from research into the tumor microenvironment. This form of breast cancer lacks all of the receptors for which treatments have been developed. Receptors are proteins that stipple the surface of cells, and certain drugs target these receptors to control the disease. Common proteins on breast cancer cells include HER2, estrogen and progesterone receptors.

Medical investigators are only now developing a clearer concept of the myriad ways in which breast cancer can proliferate and resist existing therapies. Studies involving the tumor microenvironment are opening a new window of understanding.

As it turns out, macrophages in the tumor microenvironment serve multiple roles in cancer progression and have become a potential prognostic factor for breast cancer. Metabolic changes due to “cross-talk” between the tumor and its surrounding microenvironment is currently considered one of the emerging hallmarks of several types of malignancies, including breast cancer.

Dr. Valentí Gómez of University College London and a team of cancer biologists report in Science Signaling that a growth factor secreted by macrophages promotes metabolic changes in breast cancer cells. “Dysregulation of cellular metabolism constitutes one of the hallmarks of tumor progression,” Valenti and colleagues wrote. “Because of their high proliferative rate, cancer cells have a high demand for both energy—adenosine triphosphate (ATP) – and biosynthetic precursors.”

Although most normal cells derive energy by using glycolysis as a first step before turning to a more sophisticated process called oxidative phosphorylation, cancer cells rely solely on glycolysis to generate energy. Glycolysis is a primordial form of energy production and was likely the type of energy production of the planet’s earliest forms of life. It is a much less efficient process for extracting energy, but doesn’t require oxygen, which is limited in tumors, and probably is the reason that tumors rely so heavily on glycolysis, Gómez asserted.

In a series of experiments, Gómez and the London-based team, found that secretion of the cytokine TGF-β from anti-inflammatory tumor-associated macrophages reduced the abundance of succinate dehydrogenase, an enzyme that is critical for oxidative phosphorylation in breast cancer cells. The loss of this metabolic enzyme promoted an increase in glycolysis, thereby enhancing tumor growth, blood vessel growth, and immunosuppression.

Macrophages in this dynamic microenvironment frequently support tumor growth and metastatic progression.

In experiments involving mice, Gómez and colleagues found that depleting anti-inflammatory tumor-associated macrophages or blocking TGF-β suppressed these effects in the animals. The findings revealed a metabolic mechanism underlying the tumor growth-promoting roles of tumor-associated macrophages, Gómez and colleagues found.

“We found that anti-inflammatory tumor-associated macrophages promoted a metabolic state in breast cancer cells that supported various pro-tumorigenic phenotypes,” Gómez wrote.

Even anti-inflammatory tumor-associated macrophages secreted the cytokine TGF-β that, upon engagement of its receptors in breast cancer cells, suppressed the abundance of specific transcription factors while consequently decreasing the metabolic enzyme succinate dehydrogenase in tumor cells. When that happened—the decrease in succinate dehydrogenase levels—tumor cells accumulated succinate, which enhanced the stability of the transcription factor HIF1α and reprogrammed cell metabolism to a glycolytic state.

Research, like that in the Gómez lab—and beyond—is important because it sheds new light on why cancer treatments fail and the tumor itself becomes resistant to treatment.

“Pro-tumorigenic macrophages contribute to cancer progression by affecting the central glucose metabolism, angiogenesis, and immune evasion within the tumor, and their presence may partially explain the limited efficacy of antiglycolytic treatments,” Gómez explained.

New therapies are under development targeting specific constituents of the microenvironment. “A novel combined approach should be evaluated to improve the outcome of triple-negative breast cancer therapies. For example, the use of nanoparticles to deplete/re-educate the … macrophage population within the tumor presents an intriguing therapeutic possibility, given their established association with poor prognosis.”

References: Valentí Gómez, Thomas R. Eykyn, Rami Mustapha, Fabián Flores-Borja, Victoria Male, Paul R. Barber, Antonia Patsialou, Ryan Green, Fani Panagaki, Chun W. Li, Gilbert O. Fruhwirth, Susana Ros, Kevin M. Brindle, Tony Ng, “Breast cancer–associated macrophages promote tumorigenesis by suppressing succinate dehydrogenase in tumor cells, Science Signaling (2020), Vol. 13, Issue 652, eaax4585 DOI: 10.1126/scisignal.aax4585 https://stke.sciencemag.org/content/13/652/eaax4585

This article is republished here from Medical Xpress under common creative licenses.