Hubble snaps close-up of celebrity comet NEOWISE

 NASA Hubble Space Telescope images of comet NEOWISE, taken on Aug. 8, zero in on the visitor's coma, the gossamer shell of gas and dust that surrounds its nucleus as it is heated by the Sun. This is the first time Hubble has photographed a comet of this brightness at such resolution after this close of a pass by the Sun.

The comet photos were taken after NEOWISE skimmed closest to the Sun on July 3, 2020, at a distance of 27 million miles (43 million kilometers). Other comets often break apart due to thermal and gravitational stresses at such close encounters, but Hubble's view shows that apparently NEOWISE's solid nucleus stayed intact.

"Hubble has far better resolution than we can get with any other telescope of this comet," said lead researcher Qicheng Zhang of Caltech in Pasadena, California. "That resolution is very key for seeing details very close to the nucleus. It lets us see changes in the dust right after it's stripped from that nucleus due to solar heat, sampling dust as close to the original properties of the comet as possible."

The heart of the comet, its icy nucleus, is too small to be seen by Hubble. The ball of ice may be no more than 3 miles (4.8 kilometers) across. Instead, the Hubble image captures a portion of the vast cloud of gas and dust enveloping the nucleus, which measures about 11,000 miles (18,000 kilometers) across in this photo. Hubble resolves a pair of jets from the nucleus shooting out in opposite directions. They emerge from the nucleus as cones of dust and gas, and then are curved into broader fan-like structures by the rotation of the nucleus. Jets are the result of ice sublimating beneath the surface with the resulting dust/gas being squeezed out at high velocity.

The Hubble photos may help reveal the color of the comet's dust and how those colors change as the comet moves away from the Sun. This, in turn, may explain how solar heat affects the composition and structure of that dust in the comet's coma. The ultimate goal here would be to learn the original properties of the dust to learn more about the conditions of the early solar system in which it formed.

Comet NEOWISE is considered the brightest comet visible from the Northern Hemisphere since 1997's Hale-Bopp. It's headed beyond the outer solar system, now traveling at a whopping 144,000 miles per hour. It will not return to the Sun for another nearly 7,000 years.

Researchers are currently delving more into the data to see what they're able to confirm.

NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission first discovered its namesake comet in March 2020. As the comet made its way closer to the Sun, searing heat melted its ices, unleashing dust and gas that leaves the signature tails. Throughout the summer, ground-based sky watchers in the Northern Hemisphere were able to catch a view of the traveler moving across the sky.

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Genomic analysis reveals many animal species may be vulnerable to SARS-CoV-2 infection

 Humans are not the only species facing a potential threat from SARS-CoV-2, the novel coronavirus that causes COVID-19, according to a new study from the University of California, Davis.

An international team of scientists used genomic analysis to compare the main cellular receptor for the virus in humans -- angiotensin converting enzyme-2, or ACE2 -- in 410 different species of vertebrates, including birds, fish, amphibians, reptiles and mammals.

ACE2 is normally found on many different types of cells and tissues, including epithelial cells in the nose, mouth and lungs. In humans, 25 amino acids of the ACE2 protein are important for the virus to bind and gain entry into cells.

The researchers used these 25 amino acid sequences of the ACE2 protein, and modeling of its predicted protein structure together with the SARS-CoV-2 spike protein, to evaluate how many of these amino acids are found in the ACE2 protein of the different species.

"Animals with all 25 amino acid residues matching the human protein are predicted to be at the highest risk for contracting SARS-CoV-2 via ACE2," said Joana Damas, first author for the paper and a postdoctoral research associate at UC Davis. "The risk is predicted to decrease the more the species' ACE2 binding residues differ from humans."

About 40 percent of the species potentially susceptible to SARS-CoV-2 are classified as "threatened" by the International Union for Conservation of Nature and may be especially vulnerable to human-to-animal transmission. The study was published Aug. 21 in the Proceedings of the National Academy of Sciences.

"The data provide an important starting point for identifying vulnerable and threatened animal populations at risk of SARS-CoV-2 infection," said Harris Lewin, lead author for the study and a distinguished professor of evolution and ecology at UC Davis. "We hope it inspires practices that protect both animal and human health during the pandemic."

Endangered species predicted to be at risk

Several critically endangered primate species, such as the Western lowland gorilla, Sumatran orangutan and Northern white-cheeked gibbon, are predicted to be at very high risk of infection by SARS-CoV-2 via their ACE2 receptor.

Other animals flagged as high risk include marine mammals such as gray whales and bottlenose dolphins, as well as Chinese hamsters.

Domestic animals such as cats, cattle and sheep were found to have a medium risk, and dogs, horses and pigs were found to have low risk for ACE2 binding. How this relates to infection and disease risk needs to be determined by future studies, but for those species that have known infectivity data, the correlation is high.

In documented cases of SARS-COV-2 infection in mink, cats, dogs, hamsters, lions and tigers, the virus may be using ACE2 receptors or they may use receptors other than ACE2 to gain access to host cells. Lower propensity for binding could translate to lower propensity for infection, or lower ability for the infection to spread in an animal or between animals once established.

Because of the potential for animals to contract the novel coronavirus from humans, and vice versa, institutions including the National Zoo and the San Diego Zoo, which both contributed genomic material to the study, have strengthened programs to protect both animals and humans.

"Zoonotic diseases and how to prevent human to animal transmission is not a new challenge to zoos and animal care professionals," said co-author Klaus-Peter Koepfli, senior research scientist at Smithsonian-Mason School of Conservation and former conservation biologist with the Smithsonian Conservation Biology Institute's Center for Species Survival and Center for Conservation Genomics. "This new information allows us to focus our efforts and plan accordingly to keep animals and humans safe."

The authors urge caution against overinterpreting the predicted animal risks based on the computational results, noting the actual risks can only be confirmed with additional experimental data. The list of animals can be found here.

Research has shown that the immediate ancestor of SARS-CoV-2 likely originated in a species of bat. Bats were found to be at very low risk of contracting the novel coronavirus via their ACE2 receptor, which is consistent with actual experimental data.

Whether bats directly transmitted the novel coronavirus directly to humans, or whether it went through an intermediate host, is not yet known, but the study supports the idea that one or more intermediate hosts was involved. The data allow researchers to zero in on which species might have served as an intermediate host in the wild, assisting efforts to control a future outbreak of SARS-CoV-2 infection in human and animal populations.

Additional authors on the study include: Marco Corbo, UC Davis Genome Center; Graham M. Hughes and Emma C. Teeling, University College Dublin, Ireland; Kathleen C. Keough and Katherine S. Pollard, UC San Francisco; Corrie A. Painter, Nicole S. Persky, Diane P. Genereux, Ross Swofford, Kerstin Lindblad-Toh and Elinor K. Karlsson, Broad Institute of MIT and Harvard, Cambridge, Massachussetts; Michael Hiller, Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany; Andreas R. Pfenning, Carnegie Mellon University, Pittsburgh; Huabin Zhao, Wuhan University, Wuhan, China; Oliver A. Ryder, San Diego Zoo Institute for Conservation Research, Escondido, and UC San Diego; Martin T. Nweeia, Harvard School of Dental Medicine, Boston, and Smithsonian Institution, Washington D.C.

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Cliff collapse reveals 313-million-year-old fossil footprints in Grand Canyon National Park

 Paleontological research has confirmed a series of recently discovered fossils tracks are the oldest recorded tracks of their kind to date within Grand Canyon National Park. In 2016, Norwegian geology professor, Allan Krill, was hiking with his students when he made a surprising discovery. Lying next to the trail, in plain view of the many hikers, was a boulder containing conspicuous fossil footprints. Krill was intrigued, and he sent a photo to his colleague, Stephen Rowland, a paleontologist at the University of Nevada Las Vegas.

The trailside tracks have turned out to be even more significant than Krill first imagined. "These are by far the oldest vertebrate tracks in Grand Canyon, which is known for its abundant fossil tracks" says Rowland. "More significantly," he added, "they are among the oldest tracks on Earth of shelled-egg-laying animals, such as reptiles, and the earliest evidence of vertebrate animals walking in sand dunes."

The track-bearing boulder fell from a nearby cliff-exposure of the Manakacha Formation. The presence of a detailed geologic map of the strata along the Bright Angel Trail, together with previous studies of the age of the Manakacha Formation, allowed the researchers to pin down the age of the tracks quite precisely to 313 +/- 0. 5 million years.

The newly discovered tracks record the passage of two separate animals on the slope of a sand dune. Of interest to the research team is the distinct arrangement of footprints. The researchers' reconstruction of this animal's footfall sequence reveals a distinctive gait called a lateral-sequence walk, in which the legs on one side of the animal move in succession, the rear leg followed by the foreleg, alternating with the movement of the two legs on the opposite side. "Living species of tetrapods―dogs and cats, for example―routinely use a lateral-sequence gait when they walk slowly," says Rowland. "The Bright Angel Trail tracks document the use of this gait very early in the history of vertebrate animals. We previously had no information about that." Also revealed by the trackways is the earliest-known utilization of sand dunes by vertebrate animals.

From Science Daily

Spinning black hole powers jet by magnetic flux

 Black holes are at the center of almost all galaxies that have been studied so far. They have an unimaginably large mass and therefore attract matter, gas and even light. But they can also emit matter in the form of plasma jets -- a kind of plasma beam that is ejected from the centre of the galaxy with tremendous energy. A plasma jet can extend several hundred thousand light years far into space.

When this intense radiation is emitted, the black hole remains hidden because the light rays near it are strongly bent leading to the appearance of a shadow. This was recently reported by researchers of the Event Horizon Telescope (EHT) collaboration for the massive black hole in the giant ellipse galaxy M87.

In quasar 3C279 -- also a black hole -- the EHT team found another phenomenon: At a distance of more than a thousand times the shadow of the black hole, the core of a plasma jet suddenly lit up. How the energy for this jet could get there as if through an invisible chimney was not yet known.

Extremely flickering gamma radiation detected

This quasar has now been observed with the NASA space telescope Fermi-LAT by the astrophysicist Amit Shukla, who until 2018 did research at Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany. He now is working at the Indian Institute of Technology in Indore. Shukla discovered that the core of the jet, which was found in the millimeter wavelength range, also emits high-energy gamma radiation, but with an extremely flickering brightness. This brightness can double within a few minutes, as reported in the journal Nature Communications.

The special pattern of the sequence of brightness changes is characteristic of a universal process called magnetic reconnection, which occurs in many astrophysical objects with strong magnetic fields. Solar activity also has to do with the dynamics of magnetic fields and reconnection. This was recently demonstrated by observing "campfires" in the solar atmosphere with the "Solar Orbiter" mission of the European Space Agency ESA.

Invisibly stored energy is suddenly released

But back to the quasar 3C279: "I saw how the analysis of the data revealed the special pattern of magnetic reconnection in the light curve. It felt as if I had suddenly deciphered a hieroglyph in the black hole alphabet," says Amit Shukla happily.

During reconnection, energy that is initially stored invisibly in the magnetic field is suddenly released in numerous "mini-jets." In these jets, particles are accelerated, which then produce the observed gamma radiation. Magnetic reconnection would explain how the energy reaches the jet's core from the black hole and where it ultimately comes from.

Read more at Science Daily

Unveiling rogue planets with NASA's Roman Space Telescope

 New simulations show that NASA's Nancy Grace Roman Space Telescope will be able to reveal myriad rogue planets -- freely floating bodies that drift through our galaxy untethered to a star. Studying these island worlds will help us understand more about how planetary systems form, evolve, and break apart.

Astronomers discovered planets beyond our solar system, known as exoplanets, in the 1990s. We quickly went from knowing of only our own planetary system to realizing that planets likely outnumber the hundreds of billions of stars in our galaxy. Now, a team of scientists is finding ways to improve our understanding of planet demographics by searching for rogue worlds.

"As our view of the universe has expanded, we've realized that our solar system may be unusual," said Samson Johnson, a graduate student at Ohio State University in Columbus who led the research effort. "Roman will help us learn more about how we fit in the cosmic scheme of things by studying rogue planets."

The findings, published in the Astronomical Journal, center on the Roman Space Telescope's ability to locate and characterize isolated planets. Astronomers have only tentatively discovered a few of these nomad worlds so far because they are so difficult to detect.

Finding galactic nomads

Roman will find rogue planets by conducting a large microlensing survey. Gravitational lensing is an observational effect that occurs because the presence of mass warps the fabric of space-time. The effect is extreme around very massive objects, like black holes and entire galaxies. Even solitary planets cause a detectable degree of warping, called microlensing.

If a rogue planet aligns closely with a more distant star from our vantage point, the star's light will bend as it travels through the curved space-time around the planet. The result is that the planet acts like a natural magnifying glass, amplifying light from the background star. Astronomers see the effect as a spike in the star's brightness as the star and planet come into alignment. Measuring how the spike changes over time reveals clues to the rogue planet's mass.

"The microlensing signal from a rogue planet only lasts between a few hours and a couple of days and then is gone forever," said co-author Matthew Penny, an assistant professor of physics and astronomy at Louisiana State University in Baton Rouge. "This makes them difficult to observe from Earth, even with multiple telescopes. Roman is a game-changer for rogue planet searches."

Microlensing offers the best way to systematically search for rogue planets -- especially those with low masses. They don't shine like stars and are often very cool objects, emitting too little heat for infrared telescopes to see. These vagabond worlds are essentially invisible, but Roman will discover them indirectly thanks to their gravitational effects on the light of more distant stars.

Lessons from cosmic castaways

Johnson and co-authors showed that Roman will be able to detect rogue planets with masses as small as Mars. Studying these planets will help narrow down competing models of planetary formation.

The planet-building process can be chaotic, since smaller objects collide with one another and sometimes stick together to form larger bodies. It's similar to using a piece of playdough to pick up other pieces. But occasionally collisions and close encounters can be so violent that they fling a planet out of the gravitational grip of its parent star. Unless it manages to drag a moon along with it, the newly orphaned world is doomed to wander the galaxy alone.

Rogue planets may also form in isolation from clouds of gas and dust, similar to how stars grow. A small cloud of gas and dust could collapse to form a central planet instead of a star, with moons instead of planets surrounding it.

Roman will test planetary formation and evolution models that predict different numbers of these isolated worlds. Determining the abundance and masses of rogue planets will offer insight into the physics that drives their formation. The research team found that the mission will provide a rogue planet count that is at least 10 times more precise than current estimates, which range from tens of billions to trillions in our galaxy. These estimates mainly come from observations by ground-based telescopes.

Since Roman will observe above the atmosphere, nearly a million miles away from Earth in the direction opposite the Sun, it will yield far superior microlensing results. In addition to providing a sharper view, Roman's perspective will allow it to stare at the same patch of sky continuously for months at a time. Johnson and his colleagues showed that Roman's microlensing survey will detect hundreds of rogue planets, even though it will search only a relatively narrow strip of the galaxy.

Part of the study involved determining how to analyze the mission's future data to obtain a more accurate census. Scientists will be able to extrapolate from Roman's rogue planet count to estimate how common these objects are throughout the entire galaxy.

"The universe could be teeming with rogue planets and we wouldn't even know it," said Scott Gaudi, a professor of astronomy at Ohio State University and a co-author of the paper. "We would never find out without undertaking a thorough, space-based microlensing survey like Roman is going to do."

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When learning on your own is not enough

 It is no secret that people underlie social influences. For example, at the lunch counter of a new company, when we are unsure which dish would taste good, we monitor other peoples' choices to obtain some guidance for our own menu selection. This phenomenon, which is referred to as social influence, was demonstrated experimentally starting in the 1950s by social psychologist Solomon Asch.

In the new study, researchers from the University Medical Center Hamburg-Eppendorf (UKE) in Germany placed groups of five volunteers in the same computer-based decision-making experiment, where each of them was presented with two abstract symbols. Their objective was to find out which symbol would lead to more monetary rewards in the long run. In each round of the experiment, every person first made a choice between the two symbols, and then they observed which symbols the other four people had selected; next, every person could decide to stick with their initial choice or switch to the alternative symbol. Finally, a monetary outcome, either a win or a loss, was delivered to every one according to their second decision. "This way, we enable real-time interactions among the volunteers, which greatly enhances ecological validity, " says study leader Lei Zhang, then at the UKE and now a postdoctoral researcher at the University of Vienna.

In fact, which symbol was related to more reward was always changing. At the beginning of the experiment, one of the two symbols returned monetary rewards in 70% of the time, and after a few rounds, it provided rewards in only 30% of the time. These changes took place multiple times throughout the experiment. "This so-called reversal learning paradigm will create uncertainty for volunteers so that they will always need to learn and relearn to gain more outcomes. In particular, when the reversal just happened, some people in the group may pick it faster than the others, and if so, the others could combine this social information into their own decision-making processes, " explains Jan Gläscher, who leads a research group on valuation and social decision-making at the UKE.

Expectedly, the volunteers switched more often when they were confronted with opposing choices from the others, but interestingly, the second choice (after considering social information) reflected the reward structure better than the first choice. How to explain this finding? The researchers used sophisticated models to quantify volunteers' behavior, and they unveiled separate computational strategies for direct learning and social learning. "At the beginning of each round, the volunteers were combining their own direct learning experience and social learning experience to guide their choice," Zhang says, "whereby direct learning follows a simple reinforcement learning algorithm, and social learning is instantiated by tracking the others' reward history."

Within each group, the researchers scanned one of the volunteers' brain using functional magnetic resonance imaging, which allowed them to measure when and where the brain carries out both direct learning and social learning, and to characterize whether the two types of learning actually are associated with different neural signatures. The brain scans showed that direct learning is represented in the area called the ventromedial prefrontal cortex, whereas social learning is represented in the area called the anterior cingulate cortex. These two areas also interact with an area in the middle of the brain called the striatum, "which computes both reward prediction error and social prediction error, quantifying trial-and-error learning to inform behavior" says Gläscher. "These indicate an integrated brain network supporting social influence in human decision-making."

These findings suggest that two unique types of learning signals are computed in distinct but interacting regions in the human brain, and represent separate computational strategies for decision-making in social contexts. "Direct learning is efficient in stable situations," explains Gläscher, "and when situations are changing and uncertain, social learning may play an important role together with direct learning to adapt to novel situations, such as deciding on the lunch menu at a new company."

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The most sensitive instrument in the search for life beyond Earth

 The question of whether life exists beyond the Earth is one of humanity's most fundamental questions. Future NASA missions, for example, aim to examine the ice moons of Jupiter and Saturn, which may potentially shelter life in the liquid oceans underneath the thick layer of ice, on the ground. Proving traces of life beyond the Earth is extremely challenging, however. Highly sensitive instruments which take measurements on the ground with the greatest possible degree of autonomy and with high precision -- millions of kilometers from the Earth and thus without direct support from humankind -- are required.

An international group of researchers under the leadership of Andreas Riedo and Niels Ligterink at the University of Bern have now developed ORIGIN, a mass spectrometer which can detect and identify the smallest amounts of such traces of life. They describe the instrument in a recently published article in the specialist journal Nature Scientific Reports. Niels Ligterink from the Center for Space and Habitability (CSH) is the lead author of the international study, and co-author Andreas Riedo from the Physics Institute at the University of Bern developed the instrument in the laboratories of the space research and planetary sciences divison of the Physics Institute. Various international space agencies, particularly NASA, have already expressed interest in testing ORIGIN for future missions.

New instrument required

Since the first Mars mission "Viking" in the 1970s, humanity has been searching for traces of life on Mars using highly specialized instruments which are installed on landing platforms and rovers. In its early years, Mars was Earth-like, had a dense atmosphere and even liquid water. However, as Niels Ligterink explains, Mars lost its protective atmosphere over the course of time: "As a result of this, the surface of Mars is subjected to high solar and cosmic radiation which makes life on the surface impossible." NASA's "Curiosity" rover is currently examining Mars in detail but with no concrete indications of traces of life to date.

Since the discovery by the Cassini and Galileo missions of the global oceans beneath kilometers of ice layers on Jupiter's moon Europa and Saturn's moon Enceladus, these two bodies have increasingly become the focus of the search for extraterrestrial life for researchers. According to current knowledge, the oceans have all of the properties which are not only needed for the occurrence of life, but also which provide environments in which life can exist in the long term. NASA therefore plans to land a mission on Jupiter's moon Europa around 2030 and take measurements on the ground. The goal: Identification of life. Co-author Prof. Dr. Peter Wurz from the Physics Institute at the University of Bern says: "Concepts which were specially developed for Mars cannot be simply applied to other bodies in our solar systembecause they are very different. New instruments with higher sensitivity and simpler and more robust analysis systems must be designed and used."

Unprecedented measurement sensitivity for proof of life in space

ORIGIN is one such new instrument which outperforms previous space instruments many terms over in terms of its measurement sensitivty. Various international space agencies have expressed great interest in the instrument for future missions. Andreas Riedo says: "NASA has invited us to particpaite and test our instrument in the Arctic. The Artic is the optimal test environment in the context of the EUROPA LANDER mission, which should start in 2025, which will allow us to demonstrate the performance of ORIGIN."

Amino acids are key components of life as we know it on Earth. Contemporaneous proof of certain amino acids on extraterrestrial surfaces, such as those of Europa, allow conclusions to be drawn about possible life. The measurement principle developed by the Bern-based researchers is simple. Niels Ligterink explains: "Laser pulses are directed at the surface to be examined. In the process, small amounts of material are detached, the chemical composition of which is analyzed by ORIGIN in a second step." Andreas Riedo adds: "The compelling aspect of our technology is that no complicated sample preparation techniques, which could potentially affect the result, are required. This was one of the biggest problems on Mars until now," says Riedo. The amino acids which have been analyzed with ORIGIN to date have a specific chemical fingerprint which allows them to be directly identified. Niels Ligterink: "To be honest, we didn't expect that our first measurements would already be able to identify amino acids."

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A quantum thermometer to measure the coldest temperatures in the universe

 Physicists from Trinity College Dublin have proposed a thermometer based on quantum entanglement that can accurately measure temperatures a billion times colder than those in outer space.

These ultra-cold temperatures arise in clouds of atoms, known as Fermi gases, which are created by scientists to study how matter behaves in extreme quantum states.

The work was led by the QuSys team at Trinity with postdoctoral fellows, Dr Mark Mitchison, Dr Giacomo Guarnieri and Professor John Goold, in collaboration with Professor Steve Campbell (UCD) and Dr Thomas Fogarty and Professor Thomas Busch working at OIST, Okinawa, Japan.

Discussing the proposal, Professor Goold, head of Trinity's QuSys group, explains what an ultra-cold gas is. He said:

"The standard way in which a physicist thinks about a gas is to use a theory known as statistical mechanics. This theory was invented by giants of physics such as Maxwell and Boltzmann in the 19th century. These guys revived an old idea from the Greek philosophers that macroscopic phenomena, such as pressure and temperature, could be understood in terms of the microscopic motion of atoms. We need to remember that at the time, the idea that matter was made of atoms was revolutionary."

"At the dawn of the 20th century, another theory came to fruition. This is quantum mechanics and it may be the most important and accurate theory we have in physics. A famous prediction of quantum mechanics is that single atoms acquire wave-like features, which means that below a critical temperature they can combine with other atoms into a single macroscopic wave with exotic properties. This prediction led to a century-long experimental quest to reach the critical temperature. Success was finally achieved in the 90s with the creation of the first ultra-cold gases, cooled with lasers (Nobel Prize 1997) and trapped with strong magnetic fields -- a feat which won the Nobel Prize in 2001."

"Ultra-cold gases like these are now routinely created in labs worldwide and they have many uses, ranging from testing fundamental physics theories to detecting gravitational waves. But their temperatures are mind-bogglingly low at nanokelvin and below! Just to give you an idea, one kelvin is -271.15 degrees Celsius. These gases are a billion times colder than that -- the coldest places in the universe and they are created right here on Earth."

So what exactly is a Fermi gas?

"All particles in the universe, including atoms, come in one of two types called 'bosons' and 'fermions'. A Fermi gas comprises fermions, named after the physicist Enrico Fermi. At very low temperatures, bosons and fermions behave completely differently. While bosons like to clump together, fermions do the opposite. They are the ultimate social distancers! This property actually makes their temperature tricky to measure."

Dr Mark Mitchison, the first author of the paper, explains:

"Traditionally, the temperature of an ultra-cold gas is inferred from its density: at lower temperatures the atoms do not have enough energy to spread far apart, making the gas denser. But fermions always keep far apart, even at ultra-low temperatures, so at some point the density of a Fermi gas tells you nothing about temperature."

"Instead, we proposed using a different kind of atom as a probe. Let's say that you have an ultra-cold gas made of lithium atoms. You now take a different atom, say potassium, and dunk it into the gas. Collisions with the surrounding atoms change the state of your potassium probe and this allows you to infer temperature. Technically speaking, our proposal involves creating a quantum superposition: a weird state where the probe atom simultaneously does and doesn't interact with the gas. We showed that this superposition changes over time in a way that is very sensitive to temperature."

Dr Giacomo Guarnieri gives the following analogy:

"A thermometer is just a system whose physical properties change with temperature in a predictable way. For example, you can take the temperature of your body by measuring the expansion of mercury in a glass tube. Our thermometer works in an analogous way, but instead of mercury we measure the state of single atoms that are entangled (or correlated) with a quantum gas."

Professor Steve Campbell, UCD, remarks:

"This isn't just a far-flung idea -- what we are proposing here can actually be implemented using technology available in modern atomic physics labs. That such fundamental physics can be tested is really amazing. Among the various emerging quantum technologies, quantum sensors like our thermometer are likely to make the most immediate impact, so it is a timely work and it was highlighted by the editors of Physical Review Letters for that reason."

Professor Goold adds:

"In fact one of the reasons that this paper was highlighted was precisely because we performed calculations and numerical simulations with a particular focus on an experiment that was performed in Austria and published a few years ago in Science. Here the Fermi gas is a dilute gas of trapped Lithium atoms which were in contact with Potassium impurities. The experimentalists are able to control the quantum state with radio frequency pulses and measure out information on the gas. These are operations that are routinely used in other quantum technologies."

"The timescales that are accessible are simply amazing and would be unprecedented in traditional condensed matter physics experiments. We are excited that our idea to use these impurities as a quantum thermometer with exquisite precision could be implemented and tested with existing technology."

Read more at Science Daily

Defiance and low trust in medical doctors related to vaccine scepticism

 The results of a study conducted by scientists at the University of Turku, Åbo Akademi University, and University of Bristol, show that people who tend to react negatively to rules and recommendations have lower trust in medical doctors and a more negative attitude towards vaccines, or reject vaccines for themselves or their children.

"The vaccine recommendations given by authorities or the social pressure in society to get vaccinated may cause defiance in people who tend to react negatively when they feel that they are forced to do something or that someone is trying to persuade them," says Anna Soveri, Academy Research Fellow at the University of Turku, Finland.

Because of the defiance, people may act contrary to what is expected of them.

"In this case, defiance can lead to scepticism towards medical doctors and negative attitudes towards vaccines, or even vaccine refusal," says Soveri.

Use of Alternative Medicine Quite Common

The study also showed that defiance and low trust in doctors are related to a higher likelihood to use complementary and alternative medicine (CAM). CAM refers to treatments and substances that are not included in evidence-based medicine, meaning treatments and substances for which the efficacy has not been clearly demonstrated through established scientific methods.

In the study, 770 parents of young children were presented with a list of CAM products, from which they were asked to select the ones they had used during the past 12 months to treat an illness or to maintain good health. Almost 40 per cent of the parents reported using one or more CAM products.

"To use complementary and alternative medicine may be a way for people to feel like they are free to make decisions in matters that concern their own health," says Soveri.

High Trust towards Doctors

Half of the parents reported that they had taken the flu vaccine during the preceding season. Approximately 75 per cent of the parents had accepted the childhood vaccines for their children without hesitation, but approximately seven per cent had refused to take a vaccine for their child at least once.

However, most parents expressed high or relatively high trust in doctors.

"For example, nine out of ten parents partly or completely trusted the doctors' ability to make correct diagnoses and that doctors have their patients' best interest in mind when making health-related decisions," tells Soveri.

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A healthy lifestyle for cardiovascular health also promotes good eye health

 In a new study, investigators found that ideal cardiovascular health, which is indicative of a healthy lifestyle, was associated with lower odds for ocular diseases especially diabetic retinopathy. These findings appearing in the American Journal of Medicine, published by Elsevier, suggest that interventions to prevent cardiovascular diseases may also hold promise in preventing ocular diseases.

Globally, about 2.2 billion people suffer from ocular diseases leading to vision impairment or blindness. Approximately half of these cases could have been prevented. The leading causes of vision impairment or blindness are age-related macular degeneration, diabetic retinopathy, cataract, and glaucoma.

"Earlier studies have observed associations between eye diseases and individual lifestyle factors such as smoking, obesity, or hypertension," explained lead investigator Duke Appiah, PhD, MPH, Department of Public Health, Texas Tech University Health Sciences Center, Lubbock, TX, USA. "It is known that these metrics of ideal cardiovascular health do not work alone and may interact additively to result in diseases. However, prior to our research, no other studies have comprehensively evaluated the association of all of the metrics of ideal cardiovascular health with ocular diseases."

Most ocular diseases show few symptoms at early stages and many people may not seek medical care despite readily available treatments. A recent online nationwide survey consisting of all racial and ethnic groups in the United States conducted by the Wilmer Eye Institute at Johns Hopkins University School of Medicine showed that 88 percent of the 2,044 respondents considered good vision to be vital to overall health with 47 percent of them rating losing their vision as the worst disease that could ever happen to them. Alarmingly, 25 percent did not have any knowledge about ocular diseases and their risk factors.

This research shows that following healthy lifestyle and behavior habits can all contribute to good cardiovascular health as assessed by adherence to the American Heart Association's prescription for health metric known as Life's Simple Seven (LS7). LS7 is based on the status of seven cardiovascular disease risk factors: not smoking, regular physical activity, healthy diet, maintaining normal weight, and controlling cholesterol, blood pressure, and blood glucose levels.

Practicing these healthy lifestyles together was found to be associated with lower odds for age-related macular degeneration, diabetic retinopathy, cataract, and glaucoma. Individuals with optimal cardiovascular health had 97 percent lower odds for diabetic retinopathy compared to individuals with inadequate cardiovascular health.

Investigators evaluated data from 6,118 adults aged 40 or more years old who took part in the 2005-2008 National Health and Nutrition Examination Survey. The average age of participants was 57 years old, 53 percent of whom were women. A one unit increase in LS7 scores was associated with reduced odds for age-related macular degeneration, diabetic retinopathy, and glaucoma.

"Overall, we believe that primary prevention and early detection approaches of ocular diseases are important, considering that over half of all deaths from ocular diseases and cardiovascular diseases are known to be preventable," commented co-investigators Noah De La Cruz, MPH, and Obadeh Shabaneh, MPH, both from the Department of Public Health, Texas Tech University Health Sciences Center, Lubbock, TX, USA.

Since there is a significant overlap of the risk factors for ocular diseases and cardiovascular disease, the investigators recommended that screening for ocular diseases be incorporated into existing clinical and population-based screenings for cardiovascular diseases.

Read more at Science Daily

Bird skull evolution slowed after the extinction of the dinosaurs

 From emus to woodpeckers, modern birds show remarkable diversity in skull shape and size, often hypothesized to be the result of a sudden hastening of evolution following the mass extinction that killed their non-avian dinosaur cousins at the end of the Cretaceous 66 million years ago. But this is not the case according to a study by Ryan Nicholas Felice at University College London, publishing August 18, 2020 in the open-access journal PLOS Biology. In the most detailed study yet of bird skull morphology, Felice and an international team of researchers show that the rate of evolution actually slowed in birds compared to non-avian dinosaurs.

The researchers used high-dimensional 3D geometric morphometrics to map the shape of 354 living and 37 extinct avian and non-avian dinosaurs in unprecedented detail and performed phylogenetic analyses to test for a shift in the pace of evolution after the origin of birds. They found that all regions of the skull evolved more rapidly in non-avian dinosaurs than in birds, but certain regions showed rapid pulses of evolution in particular lineages.

For example, in non-avian dinosaurs, rapid evolutionary changes in the jaw joint were associated with changes in diet, while accelerated evolution of the roof of the skull occurred in lineages that sported bony ornaments such as horns or crests. In birds, the most rapidly evolving part of the skull was the beak, which the authors attribute to adaptation to different food sources and feeding strategies.

The authors say that overall slower pace of evolution in birds compared to non-avian dinosaurs calls into question a long-standing hypothesis that the diversity seen in modern birds resulted from rapid evolution as part of an adaptive radiation following the end-Cretaceous extinction event.

 From Science Daily

Termite-fishing chimpanzees provide clues to the evolution of technology

 Researchers, who remotely videotaped a generation of wild chimpanzees learning to use tools, gain insights into how technology came to define human culture.

Using the now-ubiquitous humanmade technology of motion-activated cameras, researchers who remotely watched 25 immature chimpanzees grow up have documented how humankind's closest relatives living in the Congo Basin acquire their unique tool skills for harvesting termites, a favorite nutrient-rich element of the chimpanzee diet.

Unlike chimpanzees in East and West Africa, who use a single tool to extract termites, chimpanzees in Central Africa's Congo Basin use tool sets -- puncturing sticks or perforating twigs plus fishing probes -- to harvest the insects from underground nests or towering earthen mounds scattered across lowland forests. Arguably, chimpanzees living in this region have the most sophisticated arsenal of tool-using skills documented in the animal kingdom. Not only do they use specialized tool sets to harvest termites, ants, and honey, but they customize the implements with different modifications to improve their efficiency.

Trying to untangle how chimpanzees in the Congo Basin acquire these complex tool tasks, University of Miami biological anthropologist Stephanie Musgrave screened thousands of hours of video that recorded visits to termite nests, including those by forest elephants, leopards, and gorillas, in the Republic of Congo's Goualougo Triangle. Her reward was identifying more than 660 hours of periodic visits by 25 young chimpanzees belonging to a notoriously elusive subspecies of chimpanzee (Pan troglodytes troglodytes). Recorded over 15 years, this footage captured the development of their tool-using skills from birth until maturity.

Now, in the first study assessing when Central African chimpanzees learn to use and make their unique termite-extracting tool sets, Musgrave and fellow researchers with the Goualougo Triangle Ape Project provide novel insights into how chimpanzee cultures persist over generations -- and perhaps how technology came to be a defining aspect of human evolution.

"Chimpanzees have the most complex tool behaviors of any animals outside of humans, so studying how their youngsters become proficient at these tasks can help us better understand how early humans might have acquired complex technological skills," said Musgrave, an assistant professor in the Department of Anthropology and lead author of the study published in the American Journal of Physical Anthropology.

"Examining the development of these perishable tool kits is of particular interest because our ancestors likely also used perishable tools -- made of plants rather than stone -- but these tools are not preserved in the archeological record," she added.

For their study, Musgrave and her co-authors -- Elizabeth Lonsdorf, David Morgan, and Crickette Sanz -- conducted the first, direct comparison of tool skill acquisition between two populations of chimpanzees, those at Goualougo and those more than 1,300 miles to the east, in Gombe, Tanzania.

Lonsdorf, a professor of psychology at Franklin & Marshall College, studies chimpanzees at Gombe, the oldest field study of wild chimpanzees established by renowned primatologist Jane Goodall 60 years ago. Morgan, of Chicago's Lincoln Park Zoo, and Sanz, of Washington University in St. Louis, co-founded the Goualougo Triangle Ape Project -- the longest-running behavioral study of wild Central African chimpanzees. And, in partnership with the Wildlife Conservation Society, they have studied this population of chimpanzees for more than 20 years. They also pioneered the use of remote video technology to study wild chimpanzee behavior.

For their current study, the research team adapted the methods developed at Gombe for studying the acquisition of tool skills. And, they found notable differences in the timing and sequence in which the chimpanzees in these two populations acquired their termite-gathering skills -- differences that could relate to the challenges of using and making multiple tools at Goualougo.

While infants at both Goualougo and Gombe begin trying to use tools within their first two years, the Gombe youngsters learn to make their tools before or at the same time they become proficient at using them. In contrast, the Goualougo youngsters learn to termite fish before acquiring their tool-making skills. In early life, they typically use tools that have been discarded or transferred to them by other, older chimpanzees.

Unlike the Gombe chimpanzees, who use varied materials, the Goualougo chimpanzees also carefully select the materials for their tools, almost always from just a few species of plants. And they modify them to improve their efficiency.

"They have a mental template of the right tool for the job, and there's no mistaking the different tool types," Musgrave said. "Puncturing tools are made from a species of tree that's very durable and resistant, while fishing probes are made from smooth, pliable stems of vegetation. In contrast to Gombe, the chimpanzees at Goualougo fray these probes with their teeth to manufacture a paint-brush-like tip, which makes the tool 10 times more efficient at capturing termites."

After learning to make their own tools, Musgrave discovered, the Goualougo chimpanzees begin to employ them sequentially -- using a perforating twig plus a fishing probe to harvest the termites that inhabit the above-ground nests and a puncturing stick plus a fishing probe to extract them from the much-harder-to-pierce underground nests. The latter task is so arduous that the researchers predicted it would be the last mastered and just by a few chimpanzees. They were right.

"I've observed chimpanzees make hundreds of attempts to puncture into a subterranean termite nest," Musgrave said. "Not only does the skill require immense strength but also technical competencies that may continue to develop in adolescence."

The findings underscore how the developmental trajectory of life skills can vary considerably depending on the task and across chimpanzee populations, which have unique local cultures. In the study, the researchers note that the variation in tool traditions between sites could be linked to differences in the role of social input from other chimpanzees.

"In previous research, we documented that mother chimpanzees at Goualougo play a more active and helpful role when compared to mothers at Gombe," Musgrave said. "At Goualougo, mothers are more likely to transfer tools to their offspring. This enhanced assistance could be instrumental in the acquisition of skills over the longer time period."

Figuring out how tool traditions are passed on and how this differs within and between species, Musgrave said, could help humans understand the emergence of cumulative culture during our own evolution.

Read more at Science Daily

Tiny asteroid buzzes by Earth -- the closest flyby on record

 Near Earth Asteroids, or NEAs, pass by our home planet all the time. But an SUV-size asteroid set the record this past weekend for coming closer to Earth than any other known NEA: It passed 1,830 miles (2,950 kilometers) above the southern Indian Ocean on Sunday, Aug. 16 at 12:08 a.m. EDT (Saturday, Aug. 15 at 9:08 p.m. PDT).

At roughly 10 to 20 feet (3 to 6 meters) across, asteroid 2020 QG is very small by asteroid standards: If it had actually been on an impact trajectory, it would likely have become a fireball as it broke up in Earth's atmosphere, which happens several times a year.

By some estimates, there are hundreds of millions of small asteroids the size of 2020 QG, but they are extremely hard to discover until they get very close to Earth. The vast majority of NEAs pass by safely at much greater distances -- usually much farther away than the Moon.

"It's really cool to see a small asteroid come by this close, because we can see the Earth's gravity dramatically bend its trajectory," said Paul Chodas, director of the Center for Near-Earth Object Studies (CNEOS) at NASA's Jet Propulsion Laboratory in Southern California. "Our calculations show that this asteroid got turned by 45 degrees or so as it swung by our planet."

Zipping along at almost 8 miles per second (12.3 kilometers per second) -- a little slower than average, Chodas noted -- 2020 QG was first recorded as just a long streak in a wide-field camera image taken by the Zwicky Transient Facility. The image was taken six hours after the closest point of approach as the asteroid was heading away from Earth. A sky-scanning survey telescope funded by the National Science Foundation and NASA, the Zwicky Transient Facility is based at Caltech's Palomar Observatory in San Diego County. NASA's Near-Earth Object Observations Program funds data processing for NEO detections.

Asteroid 2020 QG enters the record books as the closest known nonimpacting asteroid; many very small asteroids impact our planet every year, but only a few have actually been detected in space a few hours before impacting Earth. On average, an asteroid the size of 2020 QG passes this closely only a few times a year.

In 2005, Congress assigned NASA the goal of finding 90% of the near-Earth asteroids that are about 460 feet (140 meters) or larger in size. These larger asteroids pose a much greater threat if they were to impact, and they can be detected much farther away from Earth, because their rate of motion across the sky is typically much smaller at that distance.

"It's quite an accomplishment to find these tiny close-in asteroids in the first place, because they pass by so fast," Chodas said. "There's typically only a short window of a couple of days before or after close approach when this small of an asteroid is close enough to Earth to be bright enough but not so close that it moves too fast in the sky to be detected by a telescope."

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Exploding stars may have caused mass extinction on Earth, study shows

 

 

 

 

 Imagine reading by the light of an exploded star, brighter than a full moon -- it might be fun to think about, but this scene is the prelude to a disaster when the radiation devastates life as we know it. Killer cosmic rays from nearby supernovae could be the culprit behind at least one mass extinction event, researchers said, and finding certain radioactive isotopes in Earth's rock record could confirm this scenario.

A new study led by University of Illinois, Urbana-Champaign astronomy and physics professor Brian Fields explores the possibility that astronomical events were responsible for an extinction event 359 million years ago, at the boundary between the Devonian and Carboniferous periods.

The paper is published in the Proceedings of the National Academy of Sciences.

The team concentrated on the Devonian-Carboniferous boundary because those rocks contain hundreds of thousands of generations of plant spores that appear to be sunburnt by ultraviolet light -- evidence of a long-lasting ozone-depletion event.

"Earth-based catastrophes such as large-scale volcanism and global warming can destroy the ozone layer, too, but evidence for those is inconclusive for the time interval in question," Fields said. "Instead, we propose that one or more supernova explosions, about 65 light-years away from Earth, could have been responsible for the protracted loss of ozone."

"To put this into perspective, one of the closest supernova threats today is from the star Betelgeuse, which is over 600 light-years away and well outside of the kill distance of 25 light-years," said graduate student and study co-author Adrienne Ertel.

The team explored other astrophysical causes for ozone depletion, such as meteorite impacts, solar eruptions and gamma-ray bursts. "But these events end quickly and are unlikely to cause the long-lasting ozone depletion that happened at the end of the Devonian period," said graduate student and study co-author Jesse Miller.

A supernova, on the other hand, delivers a one-two punch, the researchers said. The explosion immediately bathes Earth with damaging UV, X-rays and gamma rays. Later, the blast of supernova debris slams into the solar system, subjecting the planet to long-lived irradiation from cosmic rays accelerated by the supernova. The damage to Earth and its ozone layer can last for up to 100,000 years.

However, fossil evidence indicates a 300,000-year decline in biodiversity leading up to the Devonian-Carboniferous mass extinction, suggesting the possibility of multiple catastrophes, maybe even multiple supernovae explosions. "This is entirely possible," Miller said. "Massive stars usually occur in clusters with other massive stars, and other supernovae are likely to occur soon after the first explosion."

The team said the key to proving that a supernova occurred would be to find the radioactive isotopes plutonium-244 and samarium-146 in the rocks and fossils deposited at the time of extinction. "Neither of these isotopes occurs naturally on Earth today, and the only way they can get here is via cosmic explosions," said undergraduate student and co-author Zhenghai Liu.

The radioactive species born in the supernova are like green bananas, Fields said. "When you see green bananas in Illinois, you know they are fresh, and you know they did not grow here. Like bananas, Pu-244 and Sm-146 decay over time. So if we find these radioisotopes on Earth today, we know they are fresh and not from here -- the green bananas of the isotope world -- and thus the smoking guns of a nearby supernova."

Researchers have yet to search for Pu-244 or Sm-146 in rocks from the Devonian-Carboniferous boundary. Fields' team said its study aims to define the patterns of evidence in the geological record that would point to supernova explosions.

"The overarching message of our study is that life on Earth does not exist in isolation," Fields said. "We are citizens of a larger cosmos, and the cosmos intervenes in our lives -- often imperceptibly, but sometimes ferociously."

 

Read more at Science Daily

Cool new worlds found in our cosmic backyard

 How complete is our census of the Sun's closest neighbors? Astronomers using NSF's NOIRLab facilities and a team of data-sleuthing volunteers participating in Backyard Worlds: Planet 9, a citizen science project, have discovered roughly 100 cool worlds near the Sun -- objects more massive than planets but lighter than stars, known as brown dwarfs. Several of these newly discovered worlds are among the very coolest known, with a few approaching the temperature of Earth -- cool enough to harbor water clouds.

Discovering and characterizing astronomical objects near the Sun is fundamental to our understanding of our place in, and the history of, the Universe. Yet astronomers are still unearthing new residents of the Solar neighborhood. A remarkable breakthrough was announced today, with the discovery of roughly 100 cool brown dwarfs near the Sun.The new Backyard Worlds discoveries bridge a previously empty gap in the range of low-temperature brown dwarfs, identifying a long-sought missing link within the brown dwarf population.

"These cool worlds offer the opportunity for new insights into the formation and atmospheres of planets beyond the Solar System," said Aaron Meisner from the National Science Foundation's NOIRLab and the lead author of the research paper. "This collection of cool brown dwarfs also allows us to accurately estimate the number of free-floating worlds roaming interstellar space near the Sun."

This major advancement was made possible with archival data from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (KPNO) and the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), which were made available through the Community Science and Data Center (CSDC), all programs of NSF's NOIRLab. Large survey data sets were then made available to the Backyard Worlds volunteers using NOIRLab's Astro Data Lab science platform. The results, to be published in TheAstrophysical Journal, demonstrate the rapidly growing role of survey and archival data research in astronomy today.

Brown dwarfs lie somewhere between the most massive planets and the smallest stars. Lacking the mass needed to sustain nuclear reactions in their core, brown dwarfs resemble cooling embers. Their low mass, low temperature and lack of internal nuclear reactions make them extremely faint -- and therefore extremely difficult to detect. Because of this, when searching for the very coolest brown dwarfs, astronomers can only hope to detect such objects relatively close to the Sun.

To help find our Sun's coldest and nearest neighbors, the astronomers of the Backyard Worlds project turned to a worldwide network of more than 100,000 citizen scientists. These volunteers diligently inspect trillions of pixels of telescope images to identify the subtle movements of brown dwarfs and planets. Despite the abilities of machine learning and supercomputers, there's no substitute for the human eye when it comes to scouring telescope images for moving objects.

The keen eyes of the Backyard Worlds volunteers have already discovered more than 1,500 cold worlds near to the Sun, and today's paper presents roughly 100 of the coldest in that sample. According to Meisner, this is a record for any citizen science program by a factor of about 20, and 20 citizen scientists are listed as co-authors of the study. A handful of these cool worlds -- which are among the very coldest brown dwarfs known -- approach the temperature of Earth. NASA's Spitzer Space Telescope provided the brown dwarf temperature estimates.

Brown dwarfs are expected to cool as they age, passing from near-stellar temperatures down to planetary temperatures and below, fading all the while and eventually winking out. The new discoveries attest to this picture by uncovering elusive examples of brown dwarfs approaching Earth-temperature.

"This paper is evidence that the solar neighborhood is still uncharted territory and citizen scientists are excellent astronomical cartographers," said co-author Jackie Faherty of the American Museum of Natural History. "Mapping the coldest brown dwarfs down to the lowest masses gives us key insights into the low-mass star formation process while providing a target list for detailed studies of the atmospheres of Jupiter analogs."

Citizen scientist, Astro Data Lab user, and paper co-author Jim Walla added, "It's awesome to know that our discoveries are now counted among the Sun's neighbors and will be targets of further research."

Alongside the dedicated efforts of the Backyard Worlds volunteers, NOIRLab's Astro Data Lab was instrumental in this research. The technical burden of downloading billion-object astronomical catalogs is typically insurmountable for individual investigators -- including most professional astronomers. "AstroData Lab's open and accessible web portal allowed Backyard Worlds citizen scientists to easily query massive catalogs for brown dwarf candidates," explained NOIRLab astronomer Stephanie Juneau, who helped introduce the citizen scientists to Astro Data Lab. Astro Data Lab also enables convenient matching between data sets from NOIRLab telescopes and external facilities, such as NASA's WISE satellite, that jointly contributed to these brown dwarf discoveries.

In addition to Astro Data Lab's making data accessible to the Backyard Worlds collaboration, archival observations by telescopes at two other NOIRLab Programs -- CTIO and KPNO -- were also key to this discovery. "Wide-area imaging from NOIRLab's Mayall and Blanco telescopes was also critical," explained Aaron Meisner. "To select only the very coldest brown dwarfs, we inspected deep images from a variety of sensitive astronomical surveys."

"It's great to see such thrilling results from NOIRLab's efforts to broaden participation in astronomy research," said Chris Davis of the National Science Foundation, the US agency that supports operations at the Kitt Peak and Cerro Tololo observatories and at CSDC. "By making archival data from NSF's Mayall and Blanco telescopes publicly available and easily accessible through CSDC, folks with a fascination for astronomy can make a real contribution to science and to our understanding of the Universe."

The approach of the Backyard Worlds project -- searching for rare objects in large data sets -- is also one of the goals for the upcoming Vera C. Rubin Observatory. Currently under construction on Cerro Pachón in the Chilean Andes, Rubin Observatory will image the visible sky from the southern hemisphere every three nights over ten years, providing a vast amount of data that will enable new ways of doing astrophysical research.

Read more at Science Daily

Smartphones can tell when you're drunk by analyzing your walk

 Your smartphone can tell when you've had too much to drink by detecting changes in the way you walk, according to a new study published in the Journal of Studies on Alcohol and Drugs.

Having real-time information about alcohol intoxication could be important for helping people reduce alcohol consumption, preventing drinking and driving or alerting a sponsor for someone in treatment, according to lead researcher Brian Suffoletto, M.D., who was with the University of Pittsburgh School of Medicine when the research was conducted and is now with Stanford University School of Medicine's Department of Emergency Medicine.

"We have powerful sensors we carry around with us wherever we go," Suffoletto says. "We need to learn how to use them to best serve public health."

But for Suffoletto, this research is much more than academic. "I lost a close friend to a drinking and driving crash in college," he says. "And as an emergency physician, I have taken care of scores of adults with injuries related to acute alcohol intoxication. Because of this, I have dedicated the past 10 years to testing digital interventions to prevent deaths and injury related to excessive alcohol consumption."

For the study, Suffoletto and colleagues recruited 22 adults ages 21 to 43. Volunteers came to a lab and received a mixed drink with enough vodka to produce a breath alcohol concentration of .20 percent. They had one hour to finish the alcohol.

Then hourly for seven hours, participants had their breath alcohol concentration analyzed and performed a walking task. For this task, researchers placed a smartphone on each participant's lower back, secured with an elastic belt. Participants walked a straight line for 10 steps, turned around, and walked back 10 steps.

The smartphones measured acceleration and mediolateral (side to side), vertical (up and down) and anteroposterior (forward and backward) movements while the participants walked.

About 90 percent of the time, the researchers were able to use changes in gait to identify when participants' breath alcohol concentration exceeded .08 percent, the legal limit for driving in the United States.

"This controlled lab study shows that our phones can be useful to identify 'signatures' of functional impairments related to alcohol," Suffoletto says.

Although placing the smartphone on the lower back does not reflect how people carry their cell phones in real life, the research group plans to conduct additional research while people carry phones in their hands and in their pockets.

And although it was a small investigation, the researchers write that this is a "proof-of-concept study" that "provides a foundation for future research on using smartphones to remotely detect alcohol-related impairments."

"In 5 years, I would like to imagine a world in which if people go out with friends and drink at risky levels," Suffoletto says, "they get an alert at the first sign of impairment and are sent strategies to help them stop drinking and protect them from high-risk events like driving, interpersonal violence and unprotected sexual encounters."

Read more at Science Daily

Flexible and protected

 In the fight against the coronavirus, SARS-CoV-2 researchers from multiple research institutions in Germany have combined their resources to study the spike protein on the surface of the virus. With its spikes, the virus binds to human cells and infects them. The study gave surprising insights into the spike protein, including an unexpected freedom of movement and a protective coat to hide it from antibodies. The results are published in Science.

At the start of a COVID-19 infection, the coronavirus SARS-CoV-2 docks onto human cells using the spike-like proteins on its surface. The spike protein is at the centre of vaccine development because it triggers an immune response in humans. A group of German scientists, including members of the European Molecular Biology Laboratory (EMBL) in Heidelberg, the Max Planck Institute of Biophysics, the Paul-Ehrlich-Institut, and Goethe University Frankfurt have focused on the surface structure of the virus to gain insights they can use for the development of vaccines and of effective therapeutics to treat infected patients.

The team combined cryo-electron tomography, subtomogram averaging, and molecular dynamics simulations to analyse the molecular structure of the spike protein in its natural environment, on intact virions, and with near-atomic resolution. Using EMBL's state-of-the-art cryo-electron microscopy imaging facility, 266 cryotomograms of about 1000 different viruses were generated, each carrying an average of 40 spikes on its surface. Subtomogram averaging and image processing, combined with molecular dynamics simulations, finally provided the important and novel structural information on these spikes.

The results were surprising: the data showed that the globular portion of the spike protein, which contains the receptor-binding region and the machinery required for fusion with the target cell, is connected to a flexible stalk. "The upper spherical part of the spike has a structure that is well reproduced by recombinant proteins used for vaccine development," explains Martin Beck, EMBL group leader and a director of the Max Planck Institute (MPI) of Biophysics. "However, our findings about the stalk, which fixes the globular part of the spike protein to the virus surface, were new."

"The stalk was expected to be quite rigid," adds Gerhard Hummer, from the MPI of Biophysics and the Institute of Biophysics at Goethe University Frankfurt. "But in our computer models and in the actual images, we discovered that the stalks are extremely flexible." By combining molecular dynamics simulations and cryo-electron tomography, the team identified the three joints -- hip, knee and ankle -- that give the stalk its flexibility.

Read more at Science Daily

Why doesn't Ebola cause disease in bats, as it does in people?

 A new study by researchers from The University of Texas Medical Branch at Galveston uncovered new information on why the Ebola virus can live within bats without causing them harm, while the same virus wreaks deadly havoc to people. This study is now available in Cell Reports.

The Ebola virus causes a devastating, often fatal, infectious disease in people. Within the past decade, Ebola has caused two large and difficult to control outbreaks, one of which recently ended in the Democratic Republic of the Congo.

When a virus brings serious disease to people, it means that humans are not good hosts for the virus. Viruses depend on a living host for their survival and have natural reservoirs -- a hosting animal species in which a virus naturally lives and reproduces without causing disease. Bats are likely a natural reservoir for the Ebola virus, but little is known about how the virus evolves in bats.

Like most other RNA viruses, Ebola's molecules are structured in a way that makes them more prone to genomic errors and mutations than other types of viruses. Because of this, Ebola and similar viruses have a remarkable ability to adapt to and replicate in new environments.

In the study, the research team, led by Alex Bukreyev, a UTMB virologist in the departments of pathology and microbiology and immunology, working with the team of Raul Andino, University of California, San Francisco, investigated how the Ebola virus adapts to both bat and human cells. They assessed changes in mutation rates and the structure of Ebola virus populations repeatedly in both bat and human cell lines using an ultra-deep genetic sequencing.

"We identified a number of meaningful differences in how the Ebola virus evolves when placed in a human cell line relative to a bat cell line," Bukreyev said. "For instance, the RNA editing enzyme called ADAR within bat cells play a greater role in the replication and evolution of the Ebola virus than do such enzymes in human cells. We found that the envelope protein of Ebola virus undergoes a drastic increase in certain mutations within bat cells, but this was not found in human cells. This study identifies a novel mechanism by which Ebola virus is likely to evolve in bats."

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Ocean microbes could interact with pollution to influence climate

 Oceans cover almost three-quarters of the globe, yet little is known about how gases and aerosols made by ocean microbes affect weather and climate, or how human-produced pollution could influence this process. Now, scientists report they've used an "ocean-in-a-lab" to show that air pollution can change the makeup of gases and aerosols that sea spray releases into the atmosphere and, in turn, potentially alter weather patterns.

The researchers will present their results today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo.

"It's surprising that we don't know more about the central role of ocean microbes in controlling climate," says Kimberly Prather, Ph.D., the project's principal investigator. "They have the potential to influence atmospheric composition, cloud formation and weather. Humans can alter these natural processes in two ways: by changing the microbial community structure in the ocean, and by producing air pollutants that react with compounds that the microorganisms produce."

Through natural biological processes, ocean microbes -- including bacteria, phytoplankton and viruses -- produce compounds that enter the atmosphere as gases or aerosols (tiny water droplets or particles in air that form when waves crash). In addition, the microorganisms themselves can be ejected from the ocean in the form of aerosolized droplets. Some of these particles can seed clouds, absorb or reflect sunlight, or otherwise influence atmospheric conditions and weather.

"There's a standard belief that one way the ocean can regulate the temperature of the planet is through emission of gases and particles," says Prather, who is at the Scripps Institution of Oceanography at the University of California San Diego. "Some scientists refer to the ocean as the 'planetary thermostat.'"

Prather and colleagues wondered how humans might influence this thermostat. But first, they needed to learn how ocean microbes affect climate without humans. To find out, the researchers built a 108-foot-long wave channel and filled it with 3,400 gallons of seawater. They caused a phytoplankton bloom -- an overgrowth of microscopic algae that occurs naturally in oceans -- under certain conditions -- in this ocean-in-a-lab. They continuously monitored the gases and aerosols produced in the air above the water, measuring things such as aerosol size, composition, shape, enzymatic activity and pH. They also studied how natural changes in the microbial community, for example, introducing certain species of bacteria and phytoplankton, affected the cloud-forming potential of the aerosols. "The short answer is that the biology had very little effect on sea spray aerosol composition," Prather says. "Altering natural biological processes in seawater resulted in a very small change in the ability of the primary particles to form cloud droplets."

In contrast, adding a small amount of an atmospheric oxidant (hydroxyl radical, which can be generated naturally and can be enhanced in polluted atmospheres) caused an immediate shift in the composition and cloud-forming potential of marine aerosols. According to Prather, the oxidant reacted with microbe-produced gases in the air, transforming them into compounds that changed the composition of the primary sea spray aerosol and formed new types of particles. Although the researchers don't know yet how other individual pollutants affect sea spray aerosols, Prather says that it's important to study the complete gas phase mixture of pollutants to mimic and understand real-world chemical reactions.

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Cosmic gas cloud blinks in sync with circling black hole

 Scientists have detected a mysterious gamma-ray heartbeat coming from a cosmic gas cloud. The inconspicuous cloud in the constellation Aquila is beating with the rhythm of a neighbouring precessing black hole, indicating a connection between the two objects, as the team led by DESY Humboldt Fellow Jian Li and ICREA Professor Diego F. Torres from the Institute of Space Sciences (IEEC-CSIC) reports in the journal Nature Astronomy. Just how the black hole powers the cloud's gamma-ray heartbeat over a distance of about 100 light years remains enigmatic.

The research team, comprising scientists from Germany, Spain, China and the U.S., rigorously analysed more than ten years of data from the US space administration NASA's Fermi gamma-ray space telescope, looking at a so-called micro quasar. The system catalogued as SS 433 is located some 15,000 lightyears away in the Milky Way and consists of a giant star with about 30 times the mass of our sun and a black hole with about 10 to 20 solar masses. The two objects are orbiting each other with a period of 13 days, while the black hole sucks matter from the giant star.

"This material accumulates in an accretion disc before falling into the black hole, like water in the whirl above the drain of a bath tub," explains Li. "However, a part of that matter does not fall down the drain but shoots out at high speed in two narrow jets in opposite directions above and below the rotating accretion disk." This setting is known from active galaxies called quasars with monstrous black holes with millions of solar masses at their centres that shoot jets tens of thousands of lightyears into the cosmos. As SS 433 looks like a scaled-down version of these quasars, it has been dubbed a micro quasar.

The high-speed particles and the ultra-strong magnetic fields in the jet produce X-rays and gamma rays. "The accretion disc does not lie exactly in the plane of the orbit of the two objects. It precesses, or sways, like a spinning top that has been set up slanted on a table," says Torres. "As a consequence, the two jets spiral into the surrounding space, rather than just forming a straight line."

The precession of the black hole's jets has a period of about 162 days. Meticulous analysis revealed a gamma-ray signal with the same period from a position located relatively far from the micro quasar's jets, which has been labelled as Fermi J1913+0515 by the scientists. It is located at the position of an unremarkable gas enhancement. The consistent periods indicate the gas cloud's emission is powered by the micro quasar.

"Finding such an unambiguous connection via timing, about 100 light years away from the micro quasar, not even along the direction of the jets is as unexpected as amazing," says Li. "But how the black hole can power the gas cloud's heartbeat is unclear to us." Direct periodic illumination by the jet seems unlikely. An alternative that the team explored is based on the impact of fast protons (the nuclei of hydrogen atoms) produced at the ends of the jets or near the black hole, and injected into the cloud, where these subatomic particles hit the gas and produce gamma rays. Protons could also be part of an outflow of fast particles from the edge of the accretion disc. Whenever this outflow strikes the gas cloud, it lights up in gamma rays, which would explain its strange heartbeat. "Energetically, the outflow from the disc could be as powerful as that of the jets and is believed to precess in solidarity with the rest of the system," explains Torres.

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Widespread electric vehicle adoption would save billions of dollars, thousands of lives

 Northwestern University researchers have combined climate modeling with public health data to evaluate the impact of electric vehicles (EVs) on U.S. lives and the economy.

A new study found that if EVs replaced 25% of combustion-engine cars currently on the road, the United States would save approximately $17 billion annually by avoiding damages from climate change and air pollution. In more aggressive scenarios -- replacing 75% of cars with EVs and increasing renewable energy generation -- savings could reach as much as $70 billion annually.

"Vehicle electrification in the United States could prevent hundreds to thousands of premature deaths annually while reducing carbon emissions by hundreds of millions of tons," said Daniel Peters, who led the study. "This highlights the potential of co-beneficial solutions to climate change that not only curb greenhouse gas emissions but also reduce the health burden of harmful air pollution."

"From an engineering and technological standpoint, people have been developing solutions to climate change for years," added Northwestern's Daniel Horton, senior author of the study. "But we need to rigorously assess these solutions. This study presents a nuanced look at EVs and energy generation and found that EV adoption not only reduces greenhouse gases but saves lives."

The study was published online last week (August 13) in the journal GeoHealth.

During this research, Peters was an undergraduate researcher in Horton's laboratory at Northwestern. He now works for the Environmental Defense Fund. Horton is an assistant professor of Earth and planetary sciences in Northwestern's Weinberg College of Arts and Sciences.

To conduct the study, Horton, Peters and their team looked at vehicle fleet and emissions data from 2014. If 25% of U.S. drivers adopted EVs in 2014 -- and the power required to charge their batteries came from 2014's energy generation infrastructure -- then 250 million tons of carbon dioxide (CO2) emissions would have been mitigated. Although the impact of carbon emissions on the climate is well documented, combustion engines also produce other harmful pollutants, such as particulate matter and the precursors to ground-level ozone. Such pollutants can trigger a variety of health problems, including asthma, emphysema, chronic bronchitis and ultimately premature death.

After leaving tailpipes and smokestacks, pollutants interact with their environment, including background chemistry and meteorology.

"A good example is to look at nitrogen oxides (NOx), a group of chemicals produced by fossil-fuel combustion," Peters explained. "NOx itself is damaging to respiratory health, but when it's exposed to sunlight and volatile organic compounds in the atmosphere, ozone and particulate matter can form."

To account for these interactions, the researchers used a chemistry-climate model developed at the Geophysical Fluid Dynamics Laboratory. Jordan Schnell, a postdoctoral fellow in Horton's lab, performed the model experiments that simultaneously simulate the atmosphere's weather and chemistry, including how emissions from combustion engines and power generation sources interact with each other and other emissions sources in their environments.

With this model, the researchers simulated air pollutant changes across the lower 48 states, based on different levels of EV adoption and renewable energy generation. Then, they combined this information with publicly available county health data from the U.S. Environmental Protection Agency (EPA). This combination enabled the research team to assess health consequences from the air quality changes caused by each electrification scenario.

The research team assigned dollar values to the avoided climate and health damages that could be brought about by EV adoption by applying the social cost of carbon and value of statistical life metrics to their emission change results. These commonly used policy tools attach a price tag to long-term health, environmental and agricultural damages.

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Survival of the fit-ish

 It can be hard to dispute the common adage 'survival of the fittest'. After all, "most of the genes in the genome are there because they're doing something good," says Sarah Zanders, PhD, assistant investigator at the Stowers Institute for Medical Research. But, she says, "others are just there because they've figured out a way to be there."

The conventional understanding of evolution is that genes encoding a beneficial function are the most frequently transmitted, which ensures that the fittest organisms -- the ones that have traits most favorable for their environment -- survive. Less known is the fact that there exist parasitic gene elements within an organism that are doing just the opposite.

"The way one could think of it is that the genome is like a society," explains Zanders. "Within that society, there are individuals who derive their living from doing good things and making valuable contributions. But there are others who don't contribute in beneficial ways and are actually harmful to society," explains Zanders.

The Zanders Lab studies parasitic genes in Schizosaccharomyces pombe, a species of fission yeast sometimes found in the popular fermented tea drink kombucha. Because of its simplicity and fast generation times, S. pombe is a highly tractable system for studying parasitic gene elements, particularly a class known as meiotic drivers. Instead of conferring a benefit to their host, meiotic drivers confer distinct disadvantages to their host, in order to bias their own perpetuation. One method of doing so, employed by the wtf meiotic drive genes, is through selective poisoning of cells in meiosis.

Meiosis is the process of cell division through which sexually-reproducing organisms form gametes -- such as egg and sperm cells in humans, or spores in yeast -- to propagate the next generation. Normally, this process results in gametes that inherit one of two copies of each chromosome carried by the parent cell, and each copy is transmitted to gametes at an equal rate. Meiotic drivers, however, short-circuit this law of Mendelian segregation.

"Usually all the alleles -- or variants of a particular gene -- get a fair chance, and natural selection can pick the best ones," explains Zanders. "But alleles that are meiotic drivers select themselves even if they're not the best option. And they're never the best option."

In a paper published online August 13, 2020, in eLife, members of the Zanders lab explain how it could be possible that meiotic drivers persist in the population, even as they kill off many would-be hosts. It turns out that S. pombe can employ variants of other genes to help suppress the negative effect of meiotic drivers, albeit at a cost to fitness.

Usually, to propagate laboratory strains of S. pombe, they are inbred. "When you outcross two isolates that are almost identical, they produce almost no progeny," explains first author María Angélica Bravo Núñez, PhD, who was involved in the identification of the wtf genes, and who did this work in the Zanders Lab as a predoctoral researcher at the Graduate School of the Stowers Institute. "This suggested there might be some type of competition at play." Bravo Núñez and colleagues used this reasoning to seek out genes that could be in conflict in similar, but non-identical, genomes of S. pombe. The central experimental design of the current work involved outcrossing of S. pombe isolates that are over 99% identical.

"Outcrossing can have many advantages," says Bravo Núñez, such as providing a normal allele of a gene to rescue the effect of a mutant allele. "But the meiotic drive genes that we study actually exert their deleterious effect in the heterozygous scenario, where the alleles of a gene are not the same."

One illuminating experiment they did was to compare outcomes of inbred and outcrossed S. pombe isolates in a genetic background containing a mutation in rec12, which is a gene that promotes proper chromosome segregation.

"Rec12 usually promotes fertility," says Bravo Núñez. "When we removed rec12 function, the numbers of viable spores decreased, but only in the inbred scenario. The relative numbers of viable spores didn't really decrease in the outcrossed scenario." Moreover, of the viable spores, they found that survival was biased towards atypical gamete products, resulting from mis-segregation and unequal crossover of paired chromosomes. In other words, surviving spores contained the maximal number of meiotic drivers, sometimes due to inheriting an extra chromosome. This finding was surprising because extra chromosomes are usually considered very harmful. In humans, for instance, extra or missing chromosomes can lead to inviable gametes, severe birth defects, or infertility.

"When you have heterozygosity of wtf genes, making a mutation in the rec12 gene is relatively good for the organism, because that's just what has to happen in order to not kill all the progeny," says Bravo Núñez.

"We think of rec12 as this gene that's really important for fertility," explains Zanders. "But the situation is totally different when there is outcrossing. Having rec12 doesn't actually help at all, because the yeast is better off making gametes that do not result from proper chromosome segregation. This is just one example of the power of meiotic drivers to change the landscape of meiosis. Fundamentally, what is 'good' for the organism has changed."

"Having that extra chromosome is not good, and the yeast colonies look unusual, small, and irregular. But after they continue to grow for a while, the cells lose that extra chromosome and then they can thrive as haploids. So, this step is actually just temporary," says Bravo Núñez.

Precisely because meiotic drivers exert their influence in a heterozygous scenario, they are easy to miss. "There are many flavors of meiotic drive. Some forms of meiotic drive are hard to measure experimentally because the bias is so subtle," says Zanders. "We're not the first to study meiotic drivers in depth. We just have a better model system now, so we can make more progress faster."

"Drive systems tend to be repetitive, and you can usually find them in various copies in genomes," says Bravo Núñez. "They have, in many cases, already been found in other systems, such as fungi, mice, and fruit flies, but are not yet fully characterized." The study of meiotic drivers in S. pombe "will hopefully guide future research to understand other drive systems."

"Humans certainly have meiotic drive genes. Whether or not they have meiotic drive genes of the gamete-killing type is unclear," says Zanders. "Meiotic drive has likely affected the evolution of human centromeres, which are regions of chromosomes that are very important for proper chromosome segregation. Certain chromosome fusions exhibit meiotic drive in humans, as do sequences that are involved in DNA recombination. We're going to continue focusing on these and other parasitic gene elements, their strategies, and their effects."

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Social connection is the strongest protective factor for depression

 Researchers from Massachusetts General Hospital (MGH) have identified a set of modifiable factors from a field of over 100 that could represent valuable targets for preventing depression in adults. In a study published in The American Journal of Psychiatry, the team named social connection as the strongest protective factor for depression, and suggested that reducing sedentary activities such as TV watching and daytime napping could also help lower the risk of depression.

"Depression is the leading cause of disability worldwide, but until now researchers have focused on only a handful of risk and protective factors, often in just one or two domains," says Karmel Choi, PhD, investigator in the Department of Psychiatry and the Harvard T.H. Chan School of Public Health, and lead author of the paper. "Our study provides the most comprehensive picture to date of modifiable factors that could impact depression risk."

To that end, researchers took a two-stage approach. The first stage drew on a database of over 100,000 participants in the UK Biobank -- a world-renowned cohort study of adults -- to systematically scan a wide range of modifiable factors that might be associated with the risk of developing depression, including social interaction, media use, sleep patterns, diet, physical activity, and environmental exposures. This method, known as an exposure-wide association scan (ExWAS), is analogous to genome-wide association studies (GWAS) that have been widely used to identify genetic risk factors for disease. The second stage took the strongest modifiable candidates from ExWAS and applied a technique called Mendelian randomization (MR) to investigate which factors may have a causal relationship to depression risk. MR is a statistical method that treats genetic variation between people as a kind of natural experiment to determine whether an association is likely to reflect causation rather than just correlation.

This two-stage approach allowed the MGH researchers to narrow the field to a smaller set of promising and potentially causal targets for depression. "Far and away the most prominent of these factors was frequency of confiding in others, but also visits with family and friends, all of which highlighted the important protective effect of social connection and social cohesion," points out Jordan Smoller, MD, ScD associate chief for research in the MGH Department of Psychiatry, and senior author of the study. "These factors are more relevant now than ever at a time of social distancing and separation from friends and family." The protective effects of social connection were present even for individuals who were at higher risk for depression as a result of genetic vulnerability or early life trauma.

On the other hand, factors associated with depression risk included time spent watching TV, though the authors note that additional research is needed to determine if that risk was due to media exposure per se or whether time in front of the TV was a proxy for being sedentary. Perhaps more surprising, the tendency for daytime napping and regular use of multivitamins appeared to be associated with depression risk, though more research is needed to determine how these might contribute.

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Inexpensive, accessible device provides visual proof that masks block droplets

 

  Duke physician Eric Westman was one of the first champions of masking as a means to curtail the spread of coronavirus, working with a local non-profit to provide free masks to at-risk and under-served populations in the greater Durham community.

But he needed to know whether the virus-blocking claims mask suppliers made were true, to assure he wasn't providing ineffective masks that spread viruses along with false security. So he turned to colleagues in the Duke Department of Physics: Could someone test various masks for him?

Martin Fischer, Ph.D., a chemist and physicist, stepped up. As director of the Advanced Light Imaging and Spectroscopy facility, he normally focuses on exploring new optical contrast mechanisms for molecular imaging, but for this task, he MacGyvered a relatively inexpensive apparatus from common lab materials that can easily be purchased online. The setup consisted of a box, a laser, a lens, and a cell phone camera.

In a proof-of-concept study appearing online Aug. 7 in the journal Science Advances, Fischer, Westman and colleagues report that the simple, low-cost technique provided visual proof that face masks are effective in reducing droplet emissions during normal wear.

"We confirmed that when people speak, small droplets get expelled, so disease can be spread by talking, without coughing or sneezing," Fischer said. "We could also see that some face coverings performed much better than others in blocking expelled particles."

Notably, the researchers report, the best face coverings were N95 masks without valves -- the hospital-grade coverings that are used by front-line health care workers. Surgical or polypropylene masks also performed well.

But hand-made cotton face coverings provided good coverage, eliminating a substantial amount of the spray from normal speech.

On the other hand, bandanas and neck fleeces such as balaclavas didn't block the droplets much at all.

"This was just a demonstration -- more work is required to investigate variations in masks, speakers, and how people wear them -- but it demonstrates that this sort of test could easily be conducted by businesses and others that are providing masks to their employees or patrons," Fischer said.

"Wearing a mask is a simple and easy way to reduce the spread of COVID-19," Westman said. "About half of infections are from people who don't show symptoms, and often don't know they're infected. They can unknowingly spread the virus when the cough, sneeze and just talk.

"If everyone wore a mask, we could stop up to 99% of these droplets before they reach someone else," Westman said. "In the absence of a vaccine or antiviral medicine, it's the one proven way to protect others as well as yourself."

Westman and Fischer said it's important that businesses supplying masks to the public and employees have good information about the products they're providing to assure the best protection possible.

"We wanted to develop a simple, low-cost method that we could share with others in the community to encourage the testing of materials, masks prototypes and fittings," Fischer said. "The parts for the test apparatus are accessible and easy to assemble, and we've shown that they can provide helpful information about the effectiveness of masking."

Westman said he put the information immediately to use: "We were trying to make a decision on what type of face covering to purchase in volume, and little information was available on these new materials that were being used."

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