Superbug killer: New nanotech destroys bacteria and fungal cells

Researchers have developed a new superbug-destroying coating that could be used on wound dressings and implants to prevent and treat potentially deadly bacterial and fungal infections.

The material is one of the thinnest antimicrobial coatings developed to date and is effective against a broad range of drug-resistant bacteria and fungal cells, while leaving human cells unharmed.

The new coating from a team led by RMIT University is based on an ultra-thin 2D material that until now has mainly been of interest for next-generation electronics.

Studies on black phosphorus (BP) have indicated it has some antibacterial and antifungal properties, but the material has never been methodically examined for potential clinical use.

The new research, published in the American Chemical Society's journal Applied Materials & Interfaces, reveals that BP is effective at killing microbes when spread in nanothin layers on surfaces like titanium and cotton, used to make implants and wound dressings.

Broad-spectrum solvent-free layered black phosphorus as a rapid action antimicrobial, ACS Applied Materials & Interfaces, DOI: 10.1021/acsami.1c01739.

https://phys.org/news/2021-04-superbug-killer-nanotech-bacteria-fun...

Wildfires launch microbes into the air. How big of a health risk is that?

Now that they know bacteria and fungi can survive in wildfire smoke, a small group of researchers is trying to figure out the implications

https://www.sciencenews.org/article/wildfire-smoke-microbes-air-hea...

Water and quantum magnets share critical physics

In physics, things exist in phases, such as solid, liquid and gas states. When something crosses from one phase to another, we talk about a phase transition—like water boiling into steam, turning from liquid to gas.

Water boils at 100 degrees C, and its density changes dramatically, making a discontinuous jump from liquid to gas. However, if we turn up the pressure, the boiling point of water also increases, until a pressure of 221 atmospheres where it boils at 374 degrees C. Here, something strange happens: the liquid and gas merge into a single phase. Above this "critical point," there is no longer a phase transition at all, and so by controlling its pressure, water can be steered from liquid to gas without ever crossing one.

Is there a quantum version of a water-like phase transition? The current directions in quantum magnetism and spintronics require highly spin-anisotropic interactions to produce the physics of topological phases and protected qubits, but these interactions also favor discontinuous quantum phase transitions.

Previous studies have focused on smooth, continuous phase transitions in quantum magnetic materials. Now researchers have studied a discontinuous phase transition to observe the first ever critical point in a quantum magnet, similar to that of water. The work is now published in Nature.

part 2

The scientists used a quantum antiferromagnet, known in the field as SCBO (from its chemical composition: SrCu₂(BO₃)₂). Quantum antiferromagnets are especially useful for understanding how the quantum aspects of a material's structure affect its overall properties—for example, how the spins of its electrons interact to give its magnetic properties. SCBO is also a "frustrated" magnet, meaning that its electron spins can't stabilize in some orderly structure, and instead they adopt some uniquely quantum fluctuating states.

In a complex experiment, the researchers controlled both the pressure and the magnetic field applied to milligram pieces of SCBO. "This allowed us to look all around the discontinuous quantum phase transition and that way we found critical-point physics in a pure spin system.

Researchers 

performed high-precision measurements of the specific heat of SCBO, which showed its readiness to absorb energy. For example, water absorbs only small amounts of energy at -10 degrees C, but at 0 degrees C and 100 degrees C, it can take up huge amounts as every molecule is driven across the transitions from ice to liquid and liquid to gas. Just like water, the pressure-temperature relationship of SCBO forms a phase diagram showing a discontinuous transition line separating two quantum magnetic phases, with the line ending at a critical point.

Now, when a magnetic field is applied, the problem becomes richer than water. Neither magnetic phase is strongly affected by a small field, so the line becomes a wall of discontinuities in a three-dimensional phase diagram—but then one of the phases becomes unstable and the field helps push it towards a third phase."

A quantum magnetic analogue to the critical point of water, Nature (2021). DOI: 10.1038/s41586-021-03411-8

https://phys.org/news/2021-04-quantum-magnets-critical-physics.html...

Social wasps lose face recognition abilities in isolation

Just as humans are challenged from the social isolation caused by the coronavirus pandemic, a new study finds that a solitary lifestyle has profound effects on the brains of a social insect: paper wasps.

Paper wasps (Polistes fuscatus) recognize the brightly colored faces of other paper wasps, an ability they lose when reared in isolation. The wasps' ability to remember faces is similar to primates and humans, but unlike other social insects.

The study revealed that when adult wasps are housed in solitude, visual areas of their brains—especially those involved with identifying nuanced color patterns and shapes—are smaller and less developed than their peers who lived with other wasps.

Christopher M. Jernigan et al. Age and social experience induced plasticity across brain regions of the paper wasp Polistes fuscatus, Biology Letters (2021). DOI: 10.1098/rsbl.2021.0073

https://phys.org/news/2021-04-social-wasps-recognition-abilities-is...

Power of light and oxygen clears Alzheimer's disease protein in live mice

A small, light-activated molecule recently tested in mice represents a new approach to eliminating clumps of amyloid protein found in the brains of Alzheimer's disease patients. If perfected in humans, the technique could be used as an alternative approach to immunotherapy and used to treat other diseases caused by similar amyloids.

Researchers injected the molecule directly into the brains of live mice with Alzheimer's disease and then used a specialized probe to shine light into their brains for 30 minutes each day for one week. Chemical analysis of the mouse brain tissue showed that the treatment significantly reduced amyloid protein. Results from additional experiments using human brain samples donated by Alzheimer's disease patients supported the possibility of future use in humans.

The importance of this study is developing the technique to target the amyloid protein to enhance clearance of it by the immune system.

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The small molecule that the research team developed is known as a photo-oxygenation catalyst. It appears to treat Alzheimer's disease via a two-step process.

First, the catalyst destabilizes the amyloid plaques. Oxygenation, or adding oxygen atoms, can make a molecule unstable by changing the chemical bonds holding it together. Laundry detergents or other cleaners known as oxygen bleach use a similar chemical principle.

The catalyst is designed to target the folded structure of amyloid and likely works by cross-linking specific portions called histidine residues. The catalyst is inert until it is activated with near-infrared light, so in the future, researchers imagine that the catalyst could be delivered throughout the body by injection into the bloodstream and targeted to specific areas using light.

Second, the destabilized amyloid is then removed by microglia, immune cells of the brain that clear away damaged cells and debris outside healthy cells.

Photo-oxygenation by a biocompatible catalyst reduces amyloid-β levels in Alzheimer's disease model, Brain (2021). DOI: 10.1093/brain/awab058

https://medicalxpress.com/news/2021-04-power-oxygen-alzheimer-disea...

Climate change makes Indian monsoon stronger, more erratic: study

Climate change is making India's monsoon stronger and more chaotic, scientists said recently, warning of potential severe consequences for food, farming and the economy affecting nearly a fifth of the world's population.

A new analysis comparing more than 30 climate models from around the world predicts more extremely wet rainy seasons, which sweep in from the sea from roughly June to September each year.

Researchers at the Potsdam-Institute for Climate Impact Research (PIK) found strong evidence that every degree Celsius of warming would likely increase monsoon rainfall by about five percent.

The study not only confirmed trends seen in previous research, but found "global warming is increasing monsoon rainfall in India even more than previously thought.

This raises the possibility that key crops—including rice—could be swamped during crucial growing stages.

Moreover, the monsoon is likely to become more erratic as warming increases, according to the study, published in the journal Earth System Dynamics.

Anja Katzenberger, Jacob Schewe, Julia Pongratz, Anders Levermann: Robust increase of Indian monsoon rainfall and its variability under future warming in CMIP-6 models. Earth System Dynamics. DOI: 10.5194/esd-2020-80.

https://phys.org/news/2021-04-climate-indian-monsoon-seasons-chaoti...

3D-printed material to replace ivory for restoration of artifacts

For centuries, ivory was often used to make art objects. But to protect elephant populations, the ivory trade was banned internationally in 1989. To restore ivory parts of old art objects, one must therefore resort to substitute materials—such as bones, shells or plastic. However, there has not been a really satisfactory solution so far.

Researchers have now developed a high-tech substitute:  the novel material "Digory" consists of synthetic resin and calcium phosphate particles. It is processed in a hot, liquid state and hardened in the 3D printer with UV rays, exactly in the desired shape. It can then be polished and color-matched to create a deceptively authentic-looking ivory substitute.

 With the new material "Digory," not only is a better, more beautiful and easier to work with substitute for ivory available than before, the 3D technology also makes it possible to reproduce the finest details automatically. Instead of painstakingly carving them out of ivory substitute material, objects can now be printed in a matter of hours.

Thaddäa Rath et al. Developing an ivory-like material for stereolithography-based additive manufacturing, Applied Materials Today (2021). DOI: 10.1016/j.apmt.2021.101016

https://phys.org/news/2021-04-3d-printed-material-ivory-artifacts.h...

Microplastics rain from the sky

The atmosphere is laden with tiny plastic fragments. Researchers modelled the air above the western United States and found that it contains almost 1,000 tonnes of microplastic. Most — 84% — comes from roads, much of it from car tyres that constantly produce microplastics as they wear down. And 11% blows in from the ocean — which has so much plastic in it that most continents receive more from the marine environment than they put in.

https://www.pnas.org/content/118/16/e2020719118

Plastic Is Falling From the Sky. But Where’s It Coming From?

plastic rain is the new acid rain. But where is it all coming from?

New modeling published yesterday in the Proceedings of the National Academy of Sciences shows that 84 percent of airborne microplastics in the American West actually comes from the roads outside of major cities. Another 11 percent could be blowing all the way in from the ocean. (The researchers who built the model reckon that microplastic particles stay airborne for nearly a week, and that’s more than enough time for them to cross continents and oceans.)

Microplastics—particles smaller than 5 millimeters—come from a number of sources. Plastic bags and bottles released into the environment break down into smaller and smaller bits. Your washing machine is another major source: When you launder synthetic clothing, tiny microfibers slough off and get flushed to a wastewater treatment plant. That facility filters out some of the microfibers, trapping them in “sludge,” the treated human waste that’s then applied to agricultural fields as fertilizer. That loads the soil with microplastic. A wastewater plant will then flush the remaining microfibers out to sea in the treated water. This has been happening for decades, and because plastics disintegrate but don’t ever really disappear, the amount in the ocean has been skyrocketing.

In fact, this new research shows there may now be more microplastic blowing out of the ocean at any given time than there is going into it. Put another way: So much has accumulated in the ocean that the land may now be a net importer of microplastic from the sea. These microplastics aren’t just washing ashore and accumulating on beaches. When waves crash and winds scour the ocean, they launch seawater droplets into the air. These obviously contain salt, but also organic matter and microplastics. Then the water evaporates, and you're left just with the aerosols or tiny floating bits of particulate matter.  last year, a group of researchers demonstrated this phenomenon with microplastics, showing that they turn up in sea breezes.

https://www.wired.com/story/plastic-is-falling-from-the-sky/?utm_so...

Starving tuberculosis of sugars may be a new way to fight it

Tuberculosis is a devastating disease that claims over 1.5 million lives each year. The increase in TB cases that are resistant to the current antibiotics means that novel drugs to kill Mycobacterium tuberculosis (Mtb) are urgently needed. Researchers now have successfully discovered how Mycobacterium tuberculosis uses an essential sugar called trehalose, which provides a platform to design new and improved TB drugs and diagnostic agents.

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Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb) is the leading cause of death from a single infectious agent world-wide claiming over 1.5 million lives each year.

Mycobacterium tuberculosis (Mtb) is a very unique pathogen and is able to survive in the human body for decades. One way that Mtb survives is by 'eating' scarce energy sources for nutrition, whilst at the same time the human host attempts to limit the food that is available.

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However, we need a better understanding of Mtb's intracellular diet because inhibiting the pathways that allow Mtb to access and use essential food sources could be good targets for the development of new anti-tubercular agents.

One source of energy that Mtb uses is a sugar that is found in its own cell wall, called trehalose. It appears that Mtb has evolved a unique strategy to recycle and reuse this sugar to ensure that it does not waste any potential energy sources, which are in short supply.

The transport protein, which is responsible for the uptake of trehalose, called LpqY, is essential for Mtb to establish infection. If the LpqY protein is deleted and no longer able to function then Mtb can no longer supply itself with trehalose and becomes less pathogenic.

In the paper, "Structural basis of trehalose recognition by the mycobacterial LpqY-SugABC transporter," published in the Journal of Biological Chemistry, researchers from the School of Life Sciences at the University of Warwick, have unraveled the molecular basis of how Mtb uses and transports trehalose, a process which is specific to Mtb and does not occur in humans.

The team used X-ray crystallography to determine the 3-dimensional structure of LpqY and analyzed how this important transport protein is able to bind and recognize trehalose. They then went on to use a number of experimental techniques which showed that LpqY is highly specific for trehalose, is also able to recognize sugars that are similar to trehalose with small modifications and map key recognition features.

 Christopher M. Furze et al. Structural basis of trehalose recognition by the mycobacterial LpqY-SugABC transporter, Journal of Biological Chemistry (2021). DOI: 10.1016/j.jbc.2021.100307

https://phys.org/news/2021-04-starving-tuberculosis-sugars.html?utm...

Ants shrink their brains for motherhood — but can enlarge them when egg-laying ends

How the humble woodchip is cleaning up water worldwide

Australian pineapple, Danish trout, and Midwestern U.S. corn farmers are not often lumped together under the same agricultural umbrella. But they and many others who raise crops and animals face a common problem: excess nitrogen in drainage water. Whether it flows out to the Great Barrier Reef or the Gulf of Mexico, the nutrient contributes to harmful algal blooms that starve fish and other organisms of oxygen.

But there's a simple solution that significantly reduces the amount of nitrogen in drainage water, regardless of the production system or location: denitrifying bioreactors.

Denitrifying bioreactors come in many shapes and sizes, but in their simplest form, they're trenches filled with wood chips. Water from fields or aquaculture facilities flows through the trench, where bacteria living in wood chip crevices turn nitrate into a harmless gas that escapes into the air.

After gathering all the data, the message is bioreactors work.

, "Effectiveness of denitrifying bioreactors on water pollutant reduction from agricultural areas," is published in Transactions of the ASABE [DOI: 10.13031/trans.14011].

https://www.eurekalert.org/pub_releases/2021-04/uoic-hth041521.php

Coronavirus variants

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What is Artificial Intelligence?

Is a calorie always a calorie? Not when it comes to almonds,  researchers find

Researchers have found that a calorie labelled is not the same as a calorie digested and absorbed when the food source is almonds.

The findings, published in the journal Mayo Clinic Proceedings, should help alleviate concerns that almonds contribute to weight gain, which persist despite the widely recognized benefits of nuts as a plant-based source of protein, vitamins and minerals.

Nuts have generally been thought of as healthy the last two decades, but the messaging around nuts has often come with a disclaimer that they are high in fat and energy. We still see that caveat in the media and on the internet today, and it has been part of many clinical guidelines, although that is changing.

Other researchers have shown that there is a bioaccessibility issue with nuts – that a calorie labelled may not be a calorie absorbed. This study quantifies that effect with almonds in a relevant population.

The researchers found that after digestion, about 20 per cent of calories derived largely from fat in almonds remained unabsorbed, which they observed in stool samples. That translated to about two per cent less energy absorbed from the diet overall among study participants.

A person eating the same amount of almonds in a daily diet of 2,000 to 3,000 calories would absorb 40 to 60 calories less than would be predicted by Atwater factors, on which many food labels are based. That could result in weight loss up to 2.9 kilograms, or 6.3 pounds, over a year, assuming no compensation in the form of increased intake or decreased energy expenditure.

Participants in the study did not gain weight, which is consistent with the majority of high-quality trials that measure nut consumption and weight gain – some of which show an association with weight loss.

The researchers used a randomized crossover trial to study 22 women and men with high cholesterol who underwent a series of three, month-long dietary interventions separated by a week-long washout period.

All study participants consumed an NCEP Step-2 diet (low in saturated fat and cholesterol, part of the U.S. National Cholesterol Education Program). The three dietary interventions were full-dose almonds (75 grams per day or three quarters of a cup); half-dose almonds plus half-dose muffins; and full-dose muffins as a study control. The nutritional makeup of the muffins matched the almonds in amount of protein, fibre and fats.

One unique aspect of this study is that it assessed people with high cholesterol, who are at greater risk for cardiovascular disease.

https://researchnews.cc/news/6171/Is-a-calorie-always-a-calorie--No...

what happens when you turn off a light in a room made completely out of mirrors!

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00869-2/fulltext

Corona is an airborne disease: evidence

Sweat sensor could alert doctors, patients to looming COVID cytokine storm

Early in the COVID-19 pandemic, doctors recognized that patients who developed a "cytokine storm"—a surge of pro-inflammatory immune proteins—were often the sickest and at highest risk of dying. But a cytokine storm can also occur in other illnesses, such as influenza. Today, scientists report preliminary results on a sweat sensor that acts as an early warning system for an impending cytokine storm, which could help doctors more effectively treat patients.

COVID Sweat Sensor Catches Your Immune System Before It Goes Berserk

Abstract Title [American Chemical Society (ACS)].: SWEATSENSER DX an enabling technology for on demand profiling of cytokines on passively expressed eccrine sweat

https://medicalxpress.com/news/2021-04-sensor-doctors-patients-loom...

New understanding of the deleterious immune response in rheumatoid arthritis

Researchers have made a breakthrough in understanding the role played by high-risk immune genes associated with the development of rheumatoid arthritis (RA).

J.J. Lim el al., "The shared susceptibility epitope of HLA-DR4 binds citrullinated self-antigens and the TCR," Science Immunology (2021). immunology.sciencemag.org/look … 6/sciimmunol.abe0896

https://medicalxpress.com/news/2021-04-deleterious-immune-response-...

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Fit matters most when double masking to protect yourself from COVID-19

A study published today in JAMA Internal Medicine shows that wearing two face coverings can nearly double the effectiveness of filtering out SARS-CoV-2-sized particles, preventing them from reaching the wearer's nose and mouth and causing COVID-19. The reason for the enhanced filtration isn't so much adding layers of cloth, but eliminating any gaps or poor-fitting areas of a mask.

The medical procedure masks are designed to have very good filtration potential based on their material, but the way they fit our faces isn't perfect.

According to their findings, the baseline fitted filtration efficiency (FFE) of a mask differs person to person, due to each person's unique face and mask fit. But generally, a procedure mask without altering the fit, is about 40-60% effective at keeping COVID-19-sized particles out. A cloth mask is about 40% effective.

 Recent findings on doubling of face masks, shows that when a cloth mask is placed over a surgical mask, the FFE improved by about 20%, and improved even more with a snug-fitting, sleeve-type mask, such as a gaiter. When layered over procedure masks, cloth masks improve fit by eliminating gaps and holding the procedure mask closer to the face, consistently covering the nose and mouth. When a procedure mask is worn over a cloth mask, FFE improved by 16%.

 recent findings on doubling of face masks, shows that when a cloth mask is placed over a surgical mask, the FFE improved by about 20%, and improved even more with a snug-fitting, sleeve-type mask, such as a gaiter. When layered over procedure masks, cloth masks improve fit by eliminating gaps and holding the procedure mask closer to the face, consistently covering the nose and mouth. When a procedure mask is worn over a cloth mask, FFE improved by 16%.

It was found that wearing two loosely fitted masks will not give you the filtration benefit that one, snug-fitting procedure mask will.

JAMA Internal Medicine (2021). DOI: 10.1001/jamainternmed.2021.2033

https://medicalxpress.com/news/2021-04-masking-covid-.html?utm_sour...

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Streams and rivers emit more carbon dioxide at night than day

Streams and rivers emit large amounts of carbon dioxide into the atmosphere, but a new study published in Nature Geoscience led by researchers at the universities in Umeå and Lausanne shows that the flux may be greater than previously thought.

Current estimates of carbon dioxide emissions from running water are based on manual samples, where a person goes to the river, takes a sample and analyzes the content of carbon dioxide in the water. But by doing this, we had previously assumed that concentrations are stable over time. In the last decade, there has been a revolution in sensor technology and now we can measure water parameters continuously in the water and know how variable are over time.

In the current study, an international research team led by Lluis Gomez-Gener at the École polytechnique fédérale de Lausanne, Gerard Rocher-Ros and Ryan Sponseller at Umeå University has used the power of sensors to measure carbon dioxide in rivers and streams at a high-resolution. They found that carbon dioxide emissions during the night were greater than during the day.

These results are of great importance for our understanding of the role of rivers and streams in the global carbon cycle, as previous estimates, based on manual samples during the day, underestimated the actual flux.

Lluís Gómez-Gener et al. Global carbon dioxide efflux from rivers enhanced by high nocturnal emissions, Nature Geoscience (2021). DOI: 10.1038/s41561-021-00722-3

https://phys.org/news/2021-04-streams-rivers-emit-carbon-dioxide.ht...

New hydrogel can repair tears in human tissue

Scientists have developed an injectable gel that can attach to various kinds of soft internal tissues and repair tears resulting from an accident or trauma.

Researchers create light waves that can penetrate even opaque materials

Why is sugar not transparent? Because light that penetrates a piece of sugar is scattered, altered and deflected in a highly complicated way. However, as a research team from TU Wien (Vienna) and Utrecht University (Netherlands) has now been able to show, there is a class of very special light waves for which this does not apply: for any specific disordered medium—such as the sugar cube you may just have put in your coffee—tailor-made light beams can be constructed that are practically not changed by this medium, but only attenuated. The light beam penetrates the medium, and a light pattern arrives on the other side that has the same shape as if the medium were not there at all.

This idea of "scattering-invariant modes of light" can also be used to specifically examine the interior of objects. The results have now been published in the journal Nature Photonics.

This method of finding light patterns that penetrate an object largely undisturbed could  be used for imaging procedures. "In hospitals, X-rays are used to look inside the body—they have a shorter wavelength and can therefore penetrate our skin. But the way a light wave penetrates an object depends not only on the wavelength, but also on the waveform.

Pritam Pai et al. Scattering invariant modes of light in complex media, Nature Photonics (2021). DOI: 10.1038/s41566-021-00789-9

https://phys.org/news/2021-04-penetrate-opaque-materials.html?utm_s...

Earth's biggest mass extinction took ten times longer on land than in the water

Our planet's worst mass extinction event happened 252 million years ago when massive volcanic eruptions caused catastrophic climate change. The vast majority of animal species went extinct, and when the dust settled, the planet entered the early days of the Age of Dinosaurs. Scientists are still learning about the patterns of which animals went extinct and which ones survived, and why. In a new study in PNAS, researchers found that while extinctions happened rapidly in the oceans, life on land underwent a longer, more drawn-out period of extinctions.

Pia A. Viglietti el al., "Evidence from South Africa for a protracted end-Permian extinction on land," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2017045118

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Part of why scientists had looked to the marine extinctions for clues as to what happened on land is that there's a more complete fossil record of life underwater. If you want to become a fossil, dying by water, where your body will rapidly get covered by sediment, is a good way to make that happen. As a result, paleontologists have known for a while that 252 million years ago a mass extinction hit at the end of the Permian period, and within 100,000 years, more than 85% of the species living in the ocean went extinct. And while that seems like a long time to us, that's very quick in geologic time. The marine version of the end-Permian extinction took up 100,000 years out of the entire 3,800,000,000 years that life has existed—the equivalent to 14 minutes out of a whole year.

https://phys.org/news/2021-04-earth-biggest-mass-extinction-ten.htm...

Researchers find snake venom complexity is driven by prey diet

Diversity in diet plays a role in the complexity of venom in pit vipers such as rattlesnakes, copperheads and cottonmouths. Right?NO!

Now scientists found that the number of prey species a snake ate did not drive venom complexity. Rather, it was how far apart the prey species were from each other evolutionarily. It's not just diet that drives the variation in venom across snakes. It's the breadth of diet.

If a snake eats 20 different species of mammals, its venom will not be very complex. But if it eats a centipede, a frog, a bird and a mammal, it's going to have a highly complex venom because each component of that venom is affecting something different in one of the different animals the snake is feeding upon."

The journal Proceedings of the National Academy of Sciences published the findings in a paper titled "Phylogenetically diverse diets favor more complex venoms in North American pit vipers."

The research could lead to better anti-venoms and serve as a dietary database for other snake researchers.

 Matthew L. Holding el al., "Phylogenetically diverse diets favor more complex venoms in North American pitvipers," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2015579118

https://phys.org/news/2021-04-snake-venom-complexity-driven-prey.ht...

Study reveals the workings of nature's own earthquake blocker

A new study finds a naturally occurring "earthquake gate" that decides which earthquakes are allowed to grow into magnitude 8 or greater.

Sometimes, the "gate" stops earthquakes in the magnitude 7 range, while ones that pass through the gate grow to magnitude 8 or greater, releasing over 32 times as much energy as a magnitude 7.

Researchers learned about this gate while studying New Zealand's Alpine Fault, which they determined has about a 75 percent chance of producing a damaging earthquake within the next 50 years. The modeling also suggests this next earthquake has an 82 percent chance of rupturing through the gate and being magnitude 8 or greater. These insights are now published in the journal Nature Geoscience.

Jamie D. Howarth et al, Spatiotemporal clustering of great earthquakes on a transform fault controlled by geometry, Nature Geoscience (2021). DOI: 10.1038/s41561-021-00721-4

Researchers' work combined two approaches to studying earthquakes: evidence of past earthquakes collected by geologists and computer simulations run by geophysicists. Only by using both jointly were the researchers able to get new insight into the expected behavior of future earthquakes on the Alpine Fault.

https://phys.org/news/2021-04-reveals-nature-earthquake-blocker.htm...

Scientists crack 'the Brazil-nut' puzzle, how do the largest nuts rise to the top?

Scientists have for the first time captured the complex dynamics of particle movement in granular materials, helping to explain why mixed nuts often see the larger Brazil nuts gather at the top. The findings could have vital impact on industries struggling with the phenomenon, such as pharmaceuticals and mining.

Many people will have the experience of dipping their hands into a bag of mixed nuts only to find the Brazil nuts at the top. This effect can also be readily observed with cereal boxes, with the larger items rising to the top. Colloquially, this phenomenon of particles segregating by their size is known as the 'Brazil-nut effect' and also has huge implications for industries where uneven mixing can critically degrade product quality.

Now, for the first time, scientists at The University of Manchester have used time-resolved 3D imaging to show how the Brazil nuts rise upwards through a pile of nuts. The work shows the importance of particle shape in the de-mixing process.

A common difficulty with examining granular materials is following what happens to particles on the inside of the pile, which cannot easily be seen. This new research published in the journal Scientific Reports makes a key breakthrough in our understanding by utilizing advanced imaging techniques at the new National Research Facility for Lab-based X-ray Computed Tomography (NXCT)

Brazil nut mystery - part 2

The team captured the unique imaging experiment on video showing the temporal evolution of the nut mixture in 3D. Peanuts are seen to percolate downwards whilst three larger Brazil nuts are seen to rise upwards. The first Brazil nut reaches the top 10% of the bed height after 70 shear cycles, with the other two Brazil nuts reaching this height after 150 shear cycles. The remaining Brazil nuts appear trapped towards the bottom and do not rise upwards.

Critically, the orientation of the Brazil nut is key to its upward movement. It 's found that the Brazil nuts initially start horizontal but do not start to rise until they have first rotated sufficiently towards the vertical axis. Upon reaching the surface, they then return to a flat orientation.

This study highlights the important role of particle shape and orientation in segregation. Further, this ability to track the motion in 3D will pave the way for new experimental studies of segregating mixtures and will open the door to even more realistic simulations and powerful predictive models. This will allow us to better design industrial equipment to minimize size segregation thus leading to more uniform mixtures. This is critical to many industries, for instance ensuring an even distribution of active ingredients in medicinal tablets, but also in food processing, mining and construction.

Scientific Reports (2021). DOI: 10.1038/s41598-021-87280-1

https://phys.org/news/2021-04-scientists-brazil-nut-puzzle-largest-...

Study finds humans are directly influencing wind and weather over N...

A new study led by scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science provides evidence that humans are influencing wind and weather patterns across the eastern United States and western Europe by releasing CO2 and other pollutants into Earth's atmosphere.

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Ocean currents modulate oxygen content at the equator

Due to global warming, not only the temperatures in the atmosphere and in the ocean are rising, but also winds and ocean currents as well as the oxygen distribution in the ocean are changing. For example, the oxygen content in the ocean has decreased globally by about 2% in the last 60 years, particularly strong in the tropical oceans. However, these regions are characterized by a complex system of ocean currents. At the equator, one of the strongest currents, the Equatorial Undercurrent (EUC), transports water masses eastwards across the Atlantic. The water transport by the EUC is more than 60 times larger than that of the Amazon river.

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When stars get too close to each other, they cast out interstellar ...

In October 2017, humanity caught its first-ever glimpse of an interstellar object—a visitor from beyond our solar system—passing nearby the sun. We named it "Oumuamua, and its unusual properties fascinated and confounded astronomers. Less than two years later, amateur astronomer Gennady Borisov found a second interstellar object: a comet-like body that began to disintegrate as it passed within 2 AU of the sun (1 AU equals the distance from Earth to the sun). Where do these interstellar objects come from? How common are they? With a sample size of just two, it's difficult to make any generalizations just yet. On the other hand, given what we know about star formation, we can begin to make some inferences about the likely origins of these objects, and what we are likely to see of them in the future.

Russian scientists discover a new gene regulation mechanism

A team of scientists from Russia studied the role of double-stranded fragments of the maturing RNA and showed that the interaction between distant parts of the RNA can regulate gene expression. The research was published in Nature Communications.

At school, we learn that DNA is double-stranded and RNA is single-stranded, but that is not entirely true. Scientists have encountered many cases of RNA forming a double-stranded (a.k.a. secondary) structure that plays an important role in the functioning of RNA molecules. These structures are involved in the regulation of gene expression, where the double-stranded regions typically carry specific functions and, if lost, may cause severe disorders. A double-stranded structure is created by sticky complementary regions. For the strands to stick to each other, U and G should appear opposite A and C, respectively. The majority of the sticking regions are located close to one another, but the role of those located far apart has not been well understood.

Scientists from the Skoltech Center for Life Sciences (CLS) led by professor Dmitri Pervouchine and their colleagues from Russian and international laboratories used molecular and bioinformatics techniques to analyze the structure and roles of complementary RNA regions spaced far apart but capable of forming secondary structures. It transpired that the secondary structure plays an important role in the maturation of information-carrying RNA molecules and particularly in splicing, a process in which non-coding regions are cut out, and the coding regions are stitched together. The team showed that the RNA secondary structures can regulate splicing and thus contribute strongly to gene regulation.

"This paper culminates years of research on the RNA secondary structure and its role in the regulation of gene expression. We have published an extensive computation-based catalog of potentially important RNA structures, but the experimental research in this direction is just starting", professor Pervouchine comments.

Web: https://www.skoltech.ru/en.

https://www.eurekalert.org/pub_releases/2021-04/sios-rsd041921.php

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Flushing a public toilet? Don't linger, because aerosolized droplets do

Flushing a toilet can generate large quantities of microbe-containing aerosols depending on the design, water pressure or flushing power of the toilet. A variety of pathogens are usually found in stagnant water as well as in urine, feces and vomit. When dispersed widely through aerosolization, these pathogens can cause Ebola, norovirus that results in violent food poisoning, as well as COVID-19 caused by SARS-CoV-2.

Respiratory droplets are the most prominent source of transmission for COVID-19, however, alternative routes may exist given the discovery of small numbers of viable viruses in urine and stool samples. Public restrooms are especially cause for concern for transmitting COVID-19 because they are relatively confined, experience heavy foot traffic and may not have adequate ventilation.

A team of scientists put physics of fluids to the test to investigate droplets generated from flushing a toilet and a urinal in a public rest room under normal ventilation conditions. To measure the droplets, they used a particle counter placed at various heights of the toilet and urinal to capture the size and number of droplets generated upon flushing.

Results of the study, published in the journal Physics of Fluids, demonstrate how public restrooms could serve as hotbeds for airborne disease transmission, especially if they do not have adequate ventilation or if toilets do not have a lid or cover. 

The droplets were detected at heights of up to 5 feet for 20 seconds or longer after initiating the flush. Researchers detected a smaller number of droplets in the air when the toilet was flushed with a closed lid, although not by much, suggesting that aerosolized droplets escaped through small gaps between the cover and the seat.

Jesse H. Schreck et al, Aerosol generation in public restrooms, Physics of Fluids (2021). DOI: 10.1063/5.0040310

Using a public restroom? Mask up!

https://phys.org/news/2021-04-flushing-toilet-dont-linger-aerosoliz...

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Omega-3 supplements do double duty in protecting against stress

A high daily dose of an omega-3 supplement may help slow the effects of aging by suppressing damage and boosting protection at the cellular level during and after a stressful event, new research suggests.

Researchers found that daily supplements that contained 2.5 grams of omega-3 polyunsaturated fatty acids, the highest dose tested, were the best at helping the body resist the damaging effects of stress.

Compared to the placebo group, participants taking omega-3 supplements produced less of the stress hormone cortisol and lower levels of a pro-inflammatory protein during a stressful event in the lab. And while levels of protective compounds sharply declined in the placebo group after the stressor, there were no such decreases detected in people taking omega-3s.

The supplements contributed to what the researchers call stress resilience: reduction of harm during stress and, after acute stress, sustained anti-inflammatory activity and protection of cell components that shrink as a consequence of aging.

Annelise A. Madison et al. Omega-3 supplementation and stress reactivity of cellular aging biomarkers: an ancillary substudy of a randomized, controlled trial in midlife adults, Molecular Psychiatry (2021). DOI: 10.1038/s41380-021-01077-2

https://medicalxpress.com/news/2021-04-omega-supplements-duty-stres...

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Orbital debris threatens satellites: Time to act

Should Facebook and Twitter review your posts before they're published?

The day is coming when your posts to social media may travel through checkpoints before the messages go public.

All of your posts to Facebook, Twitter, and other social platforms may be instantly examined by an artificial intelligence filter that roots out hate speech and misinformation. Some posts that have been flagged by artificial intelligence may then be reviewed by a human supervisor.

social media filters are needed because the platforms have grown and scaled faster than they can be regulated—with the result that social channels are now being accused of enabling hate speech and misinformation that contributes to violence.

comprehensive regulations will include heavy government fines for platforms that enable hate speech and misinformation. Such penalties will create additional incentives to invest in the necessary content moderation and technology.

https://techxplore.com/news/2021-04-facebook-twitter-theyre-publish...

New process makes 'biodegradable' plastics truly compostable

Biodegradable plastics have been advertised as one solution to the plastic pollution problem bedeviling the world, but today's "compostable" plastic bags, utensils and cup lids don't break down during typical composting and contaminate other recyclable plastics, creating headaches for recyclers. Most compostable plastics, made primarily of the polyester known as polylactic acid, or PLA, end up in landfills and last as long as forever plastics.

Scientists have now invented a way to make these compostable plastics break down more easily, with just heat and water, within a few weeks, solving a problem that has flummoxed the plastics industry and environmentalists.

The new process involves embedding polyester-eating enzymes in the plastic as it's made. These enzymes are protected by a simple polymer wrapping that prevents the enzyme from untangling and becoming useless. When exposed to heat and water, the enzyme shrugs off its polymer shroud and starts chomping the plastic polymer into its building blocks—in the case of PLA, reducing it to lactic acid, which can feed the soil microbes in compost. The polymer wrapping also degrades.

The process eliminates microplastics, a byproduct of many chemical degradation processes and a pollutant in its own right.

Near-complete depolymerization of polyesters with nano-dispersed enzymes, Nature (2021). DOI: 10.1038/s41586-021-03408-3

https://phys.org/news/2021-04-biodegradable-plastics-compostable.ht...

Lifelong burden of high stress hormones in female baboons shortens life expectancy

Female baboons may not have bills to pay or deadlines to meet, but their lives are extremely challenging. They face food and water scarcity and must be constantly attuned to predators, illnesses and parasites, all while raising infants and maintaining their social status.

A new study appearing April 21 in Science Advances shows that female baboons with high life-long levels of glucocorticoids, the hormones involved in the 'fight or flight' response, have a greater risk of dying than those with lower levels.

Glucocorticoids are a group of hormones that help prepare the body for a challenge. While these hormones have many functions in the body, persistently high levels of glucocorticoids in the bloodstream can be a marker of stress.

Females with higher levels of glucocorticoids in their feces, either due to more frequent exposure to different types of challenges, or more intense stress responses, tended to die younger.

 F.A. Campos at University of Texas at San Antonio in San Antonio, TX el al., "Glucocorticoid exposure predicts survival in female baboons," Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abf6759

https://phys.org/news/2021-04-lifelong-burden-higher-stress-hormone...

Microplastics affect global nutrient cycle and oxygen levels in the...

The effects of the steadily increasing amount of plastic in the ocean are complex and not yet fully understood. Scientists at GEOMAR Helmholtz Centre for Ocean Research Kiel have now shown for the first time that the uptake of microplastics by zooplankton can have significant effects on the marine ecosystem even at low concentrations. The study, published in the international journal Nature Communications, further indicates that the resulting changes may be responsible for a loss of oxygen in the ocean beyond that caused by global warming.

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Climate 'tipping points' need not be the end of the world

The disastrous consequences of climate "tipping points" could be averted if global warming was reversed quickly enough, new research suggests.

Flying a helicopter on Mars

NASA Extracts Breathable Oxygen From Thin Martian Air

: NASA has logged another extraterrestrial first on its latest mission to Mars: converting carbon dioxide from the Martian atmosphere into pure, breathable oxygen, the U.S. space agency said on Wednesday.

The unprecedented extraction of oxygen, literally out of thin air on Mars, was achieved Tuesday by an experimental device aboard Perseverance, a six-wheeled science rover that landed on the Red Planet February 18 after a seven-month journey from Earth.

In its first activation, the toaster-sized instrument dubbed MOXIE, short for Mars Oxygen In-Situ Resource Utilisation Experiment, produced about 5 grams of oxygen, equivalent to roughly 10 minutes’ worth of breathing for an astronaut, NASA said.

The instrument works through electrolysis, which uses extreme heat to separate oxygen atoms from molecules of carbon dioxide, which accounts for about 95% of the atmosphere on Mars.

The remaining 5% of Mars’ atmosphere, which is only about 1% as dense Earth’s, consists primarily of molecular nitrogen and argon. Oxygen exists on Mars in negligible trace amounts.

Although the initial output was modest, the feat marked the first experimental extraction of a natural resources from the environment of another planet for direct use by humans.

https://www.reuters.com/article/space-exploration-mars-oxygen/nasa-...

https://science.thewire.in/spaceflight/nasa-extracts-breathable-oxy...

Part 3

The solution is clear: fossil fuels must be kept in the ground. 

Leaders, not industry, hold the power and have the moral responsibility to take bold  actions to address this crisis. We call on world leaders to work together in a spirit of  international cooperation to: 

• End new expansion of oil, gas and coal production in line with the best available science as outlined by the Intergovernmental Panel on Climate Change and United Nations Environment Program; 
• Phase out existing production of oil, gas and coal in a manner that is fair and equitable, taking into account the responsibilities of countries for climate change and their respective dependency on fossil fuels, and capacity to  transition; 
• Invest in a transformational plan to ensure 100% access to renewable energy globally, support dependent economies to diversify away from fossil fuels, and enable people and communities across the globe to flourish  through a global just transition. 

Fossil fuels are the greatest contributor to climate change. Allowing the  continued expansion of this industry is unconscionable. The fossil fuel system  is global and requires a global solution – a solution the Leaders’ Climate Summit  must work towards. And the first step is to keep fossil fuels in the ground. 

https://fossilfueltreaty.org/nobel-letter

Part 2

The burning of fossil fuels is responsible for almost 80% of carbon dioxide  emissions since the industrial revolution. In addition to being the leading source of  emissions, there are local pollution, environmental and health costs associated with  extracting, refining, transporting and burning fossil fuels. These costs are often paid  by Indigenous peoples and marginalized communities. Egregious industry practices  have led to human rights violations and a fossil fuel system that has left billions of  people across the globe without sufficient energy to lead lives of dignity. 

For both people and the planet, continued support must be given to tackling climate  change through the United Nations Framework Convention on Climate Change and  its Paris Agreement. Failure to meet the Paris Agreement’s temperature limit of  1.5°C risks pushing the world towards catastrophic global warming. 

Yet, the Paris Agreement has no mention of oil, gas or coal. Meanwhile, the  fossil fuel industry continues to plan new projects. Banks continue to fund new  projects. According to the most recent United Nations Environment Programme  report, 120% more coal, oil, and gas will be produced by 2030 than is consistent  with limiting warming to 1.5°C. Efforts to meet the Paris Agreement and to reduce  demand for fossil fuels will be undermined if supply continues to grow.

A statement of the Nobel Laureates on the occasion of World Leaders meet on climate. 27 Nobel Chemists and 22 Nobel Physicists are signatories of this letter demanding "Keep the Fossil Fuels in the Ground" .

Part 1

Nobel Laureates’ Statement to Climate Summit World Leaders: Keep  Fossil Fuels in the Ground 

As Nobel Laureates from peace, literature, medicine, physics, chemistry  and economic sciences, and like so many people around the globe, we are  seized by the great moral issue of our time: the climate crisis and  commensurate destruction of nature. 

Climate change is threatening hundreds of millions of lives, livelihoods across every  continent and is putting thousands of species at risk. The burning of fossil fuels – coal, oil, and gas – is by far the major contributor to climate change. 

We write today, on the eve of Earth Day 2021 and the Leaders’ Climate  Summit, hosted by President Biden, to urge you to act now to avoid a  climate catastrophe by stopping the expansion of oil, gas and coal. 

We welcome President Biden and the US government’s acknowledgement in the  Executive Order that “Together, we must listen to science and meet the moment.”  Indeed, meeting the moment requires responses to the climate crisis that will  define legacies. Qualifications for being on the right side of history are clear. 

For far too long, governments have lagged, shockingly, behind what  science demands and what a growing and powerful people-powered  movement knows: urgent action is needed to end the expansions of fossil  fuel production; phase out current production; and invest in renewable  energy.

Scientists glimpse signs of a puzzling state of matter in a superconductor

Unconventional superconductors contain a number of exotic phases of matter that are thought to play a role, for better or worse, in their ability to conduct electricity with 100% efficiency at much higher temperatures than scientists had thought possible—although still far short of the temperatures that would allow their wide deployment in perfectly efficient power lines, maglev trains and so on.

Now scientists have glimpsed the signature of one of those phases, known as pair-density waves or PDW, and confirmed that it's intertwined with another phase known as charge density wave (CDW) stripes—wavelike patterns of higher and lower electron density in the material.

Observing and understanding PDW and its correlations with other phases may be essential for understanding how superconductivity emerges in these materials, allowing electrons to pair up and travel with no resistance.

 H. Huang et al. Two-Dimensional Superconducting Fluctuations Associated with Charge-Density-Wave Stripes in La1.87Sr0.13Cu0.99Fe0.01O4, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.167001

https://phys.org/news/2021-04-scientists-glimpse-puzzling-state-sup...

Toxic masculinity: Y chromosome contributes to a shorter lifespan in male flies

Males may have shorter lifespans than females due to repetitive sections of the Y chromosome that create toxic effects as males get older. These new findings appear in a study published April 22 in PLOS Genetics.

In humans and other species with XY sex chromosomes, females often live longer than males. One possible explanation for this disparity may be repetitive sequences within the genome. While both males and females carry these repeat sequences, scientists have suspected that the large number of repeats on the Y chromosome may create a "toxic y effect" that shortens males' lives.

To test this idea, researchers studied male fruit flies from the species Drosophila miranda, which have about twice as much repetitive DNA as females and a shorter lifespan. They showed that when the DNA is in its tightly packed form inside the cells of young male flies, the repeat sections are turned off. But as the flies age, the DNA assumes a looser form that can activate the repeat sections, resulting in toxic side effects.

The new study demonstrates that Y chromosomes that are rich in repeats are a genomic liability for males. The findings also support a more general link between repeat DNA and aging, which currently, is poorly understood. Previous studies in fruit flies have shown that when repeat sections become active, they impair memory, shorten the lifespan and cause DNA damage. This damage likely contributes to aging's physiological effects, but more research will be needed to uncover the mechanisms underlying repeat DNA's toxic effects.

Nguyen AH, Bachtrog D (2021) Toxic Y chromosome: Increased repeat expression and age-associated heterochromatin loss in male Drosophila with a young Y chromosome. PLoS Genet 17(4): e1009438. doi.org/10.1371/journal.pgen.1009438

https://phys.org/news/2021-04-toxic-masculinity-chromosome-contribu...

New material could better protect soldiers, athletes and motorists

Soldiers, athletes, and motorists could lead safer lives thanks to a new process that could lead to more efficient and re-useable protection from shock and impact, explosion, and vibration, according to a new study.

Pressurized insertion of aqueous solutions into water-repellent nanoporous materials, such as zeolites and metal-organic frame works, could help to create high-performance energy absorbing systems.

An international research team experimented with hydrothermally stable zeolitic imidazolate frameworks (ZIFs) with a 'hydrophobic' cage-like molecular structure—finding that such systems are remarkably effective energy absorbers at realistic, high-rate loading conditions, and this phenomenon is associated with the water clustering and mobility in nanocages.

High-rate nanofluidic energy absorption in porous zeolitic frameworks, Nature Materials (2021). DOI: 10.1038/s41563-021-00977-6

https://phys.org/news/2021-04-material-soldiers-athletes-motorists....

Eliminating resistant bacteria with nanoparticles

Novel nanoparticles developed by researchers  detect multi-resistant bacteria hiding in body cells and kill them. The scientists' goal is to develop an antibacterial agent that is effective where conventional antibiotics remain ineffective.

In the arms race "mankind against bacteria," bacteria are currently ahead of us. Our former miracle weapons, antibiotics, are failing more and more frequently when germs use tricky maneuvers to protect themselves from the effects of these drugs. Some species even retreat into the inside of human cells, where they remain "invisible" to the immune system. These particularly dreaded pathogens include multi-resistant staphylococci (MRSA), which can cause life-threatening diseases such as sepsis or pneumonia.

In order to track down the germs in their hideouts and eliminate them, a team of researchers  is now developing nanoparticles that use a completely different mode of action from conventional antibiotics: While antibiotics have difficulty in penetrating human cells, these nanoparticles can penetrate the membrane of affected cells. Once there, they can fight the bacteria.

They used cerium oxide, a material with antibacterial and anti-inflammatory properties in its nanoparticle form. The researchers combined the cerium oxide with a bioactive ceramic material known as bioglass and synthesized nanoparticle hybrids from the two materials.

In cell culture and using electron microscopy, they investigated the interactions between the hybrid nanoparticles, human cells and bacteria. When the scientists treated cells infected with bacteria with the nanoparticles, the bacteria inside the cells began to dissolve. However, if the researchers specifically blocked the uptake of the hybrid particles into the cells, the antibacterial effect was gone.

The particles' exact mode of action is not yet fully understood. It has been shown that other metals also have antimicrobial effects. However, cerium is less toxic to human cells than, for instance, silver. Scientists currently assume that the nanoparticles affect the cell membrane of the bacteria, creating reactive oxygen species that lead to the destruction of the germs. Since the cell membrane of human cells is structured differently than that of bacteria, our cells are not affected by this process.

The researchers think that resistance is less likely to develop against a mechanism of this kind. 

Martin T. Matter et al. Inorganic nanohybrids combat antibiotic-resistant bacteria hiding within human macrophages, Nanoscale (2021). DOI: 10.1039/d0nr08285f

https://phys.org/news/2021-04-resistant-bacteria-nanoparticles.html...

A novel optical physics method to measure the expansion of the univ...

Quasars are extraordinarily distant celestial objects that throw off a massive amount of light, and astrophysicists use them to probe cosmological theories.

Plastic: What we eat and breathe

Take a deep breath, drink a glass of water, eat a snack. If you do any of these things, it's likely that you are also inhaling and ingesting tiny particles of plastic, as much as a credit card's weight each week. Plastic pollution is everywhere, including in our bodies.

The industry also peddled the myth that recycling is the solution, even though it has long known that this is not economically viable. Today, we pay for recycling infrastructure and dutifully sort our waste into bins, even though only 10% of all plastic is recycled.

Individuals don't start pollution. The industry does. We must demand that they stop it.

https://phys.org/news/2021-04-plastic.html?utm_source=nwletter&...

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20% of groundwater wells around the world at risk of running dry, study says

If groundwater levels continue to decline as they have over the last several decades, new research suggests approximately one-fifth of groundwater wells around the world will be at risk of running dry.

Groundwater wells are the main source of water for roughly half the globe's population, but over the last half-century, many of the planet's major aquifers have suffered from mismanagement, growing human pressures and prolonged droughts.

The latest analysis, published Thursday in the journal Science, suggests millions of wells could run dry if aquifers continue to be depleted and regional water tables keep declining.

https://science.sciencemag.org/content/372/6540/418

https://www.upi.com/Science_News/2021/04/22/groundwater-wells-globa...