Teamwork makes light shine ever brighter

If you’re looking for one technique to maximize photon output from plasmons, stop. It takes two to wrangle. Rice University physicists came across a phenomenon that boosts the light from a nanoscale device more than 1,000 times greater than they anticipated. When looking at light coming from a plasmonic junction, a microscopic gap between two gold nanowires, there are conditions in which applying optical or electrical energy individually prompted only a modest amount of light emission. Applying both together, however, caused a burst of light that far exceeded the output under either individual stimulus. 

**

Finger tap-operated virtual realities

Study shows stronger brain activity after writing on paper than on tablet or smartphone

Unique, complex information in analog methods likely gives brain more details to trigger memory.

A study of Japanese university students and recent graduates has revealed that writing on physical paper can lead to more brain activity when remembering the information an hour later. Researchers say that the unique, complex, spatial and tactile information associated with writing by hand on physical paper is likely what leads to improved memory.

"Actually, paper is more advanced and useful compared to electronic documents because paper contains more one-of-a-kind information for stronger memory recall.

Contrary to the popular belief that digital tools increase efficiency, volunteers who used paper completed the note-taking task about 25% faster than those who used digital tablets or smartphones.

Keita Umejima, Takuya Ibaraki, Takahiro Yamazaki, and Kuniyoshi L. Sakai. 19 March 2021. Paper Notebooks vs. Mobile Devices: Brain Activation Differences During Memory Retrieval. Frontiers in Behavioral Neuroscience. DOI: 10.3389/fnbeh.2021.634158

Sakai lab: https://www.sakai-lab.jp/english/

Graduate School of Arts and Sciences: https://www.c.u-tokyo.ac.jp/eng_site/

https://eurekalert.org/pub_releases/2021-03/uot-sss031821.php

World's smallest origami bird shows potential of nanoscale machines

Carbon pawprint: is man's best friend the planet's enemy?

Is your adorable puppy as bad for the planet as a gas-guzzling SUV?

While the precise carbon pawprint of our pets is the source of scientific debate, one thing is becoming increasingly clear: lovable, they may be, cats and dogs have an impact on the planet.

No doubt, they bring a lot of good to people, both working animals and companion animals. But they mostly eat meat. 

However, some argue that because most pet foods are based on secondary products from the human food industry, especially the ingredients that are animal-based, the environmental costs of those ingredients are not the same as those being consumed by humans.

Yet in some countries meat is reared specifically for animal consumption. As with humans—animal carbon footprints "depend on where you live in the world".

But scientists can agree on at least one thing: a large dog, logically, eats more than a small cat and therefore has a bigger environmental impact. It si not possible to make a dog fully vegetarian.

So what can the environmentally conscious animal lovers out there do to mitigate the damage caused by their furry friends?

Experts suggest considering other species of animals to have as pets, such as hamsters or birds. But if you don't want to have an ecological pawprint, don't have a pet at all. Let them live in wilderness using natural resources and  bound by natural laws.

But one environmental impact from outdoor cats  can't be avoided. A massacre all around your home: dead birds, shrews, lizards...

One solution for animals and the planet would be to cut down or diversify the protein in their diet.

Several dried food producers already use insects in their kibble, although there is still debate over the environmental merits of various animal foods and their production.

https://phys.org/news/2017-08-truth-cats-dogs-environmental-impact....

https://phys.org/news/2021-03-carbon-pawprint-friend-planet-enemy.h...

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Microscope that detects individual viruses could power rapid diagno...

A fast, low-cost technique to see and count viruses or proteins from a sample in real time, without any chemicals or dyes, could underpin a new class of devices for rapid diagnostics and viral load monitoring, including HIV and the virus that causes COVID-19. Researchers at the University of Illinois Urbana-Champaign described the technique, called Photonic Resonator Interferometric Scattering Microscopy, or PRISM, in the journal Nature Communications. 

Researchers have developed a new form of microscopy that amplifies the interaction between light and biological materials. One can use it for very rapid and sensitive forms of diagnostic testing, and also as a very powerful tool for understanding biological processes at the scale of individual items, like counting individual proteins or recording individual protein interactions.

**

The new crisis in cosmology:

Scientists Just Demonstrated How These 'Spiders' Might Form on Mars

We may not have detected life on Mars, but we have found 'spiders'... of a sort.

They're called araneiforms: dark, spider-like systems of branching, fractal troughs found only in the southern polar regions of the red planet. There's nothing like them on Earth, or any other planet in the Solar System.

That makes it tricky to understand what creates them, but scientists have just obtained the first physical evidence that supports the most popular model, known as Kieffer's hypothesis. According to this idea, the spider-like forms are shaped by the direct sublimation of frozen carbon dioxide (CO₂).

"This research presents the first set of empirical evidence for a surface process that is thought to modify the polar landscape on Mars

https://www.nature.com/articles/s41598-021-82763-7

https://www.sciencealert.com/there-are-spiders-on-mars-like-nothing...

The Sensitivity of Human Fingertips Is Greater Than We Ever Imagined

Skin – the largest organ in the human body – envelops us from head to toe, letting us touch, feel, and interact with the outside world. But there's one part of that organ even more attuned to touch than any other.

A new study has revealed just how receptive the sensory neurons in our fingers are: As it turns out, we can detect touch on the minuscule scale of a single fingerprint ridge.

Sensory neurons attached to receptors are dotted just underneath the skin's surface, allowing us to detect touch, vibration, pressure, pain, and lots more. Our hands alone contain tens of thousands of these neurons, each one with receptors on a small surface area of the skin, called a receptive field.

To map these fields, the researchers strapped down the arms of 12 healthy people and glued their fingernails to plastic holders to really make sure they couldn't move. A machine then wheeled tiny, 0.4 millimeter-wide cones around 7 mm apart across their skin (you can see what that looks like below) and the team recorded each neuron's response using an electrode in the participants' arms.

Specifically, they were mapping the more sensitive zones – known as subfields – within these receptive fields.

By calculating the sensory neuron detection areas and mapping them onto the fingerprint, the team found that the detection area's width was equivalent to the width of one fingerprint ridge.

These subfields also didn't move when the machine wheeled the dots faster or slower, or changed directions, suggesting that these sensitive areas are anchored to the fingerprint ridges themselves.

"We report that the sensitivity of the subfield arrangement for both neuron types on average corresponds to a spatial period of ~0.4 mm and provide evidence that a subfield's spatial selectivity arises because its associated receptor organ measures mechanical events limited to a single papillary ridge," the researchers write in their new paper.

https://www.jneurosci.org/content/early/2021/03/08/JNEUROSCI.1716-2...

https://www.sciencealert.com/our-fingertips-have-a-secret-weapon-th...

To produce more food, scientists look to get more mileage out of plant enzymes

Enzymes play essential roles in the cells of every living thing, from bacteria, to plants to people. Some do their jobs a few times and fizzle out. Others can repeat a task hundreds of thousands of times before they quit.

Organisms put a lot of energy into replacing worn out enzymes, energy they could put into other processes. In plants grown for food, fuel, fiber or other purposes, longer lasting enzymes could translate into increased yields.

 Andrew D. Hanson el al., "The number of catalytic cycles in an enzyme's lifetime and why it matters to metabolic engineering," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2023348118

https://phys.org/news/2021-03-food-scientists-mileage-enzymes.html?...

**

Five myths about the Big Bang

The whole universe was packed together in an infinitely small point, then it exploded, and the entire mass that made up the universe was sent out into space.

No, this is not how it happened.

The Big Bang theory is that about 14 billion years ago the universe was in a state that was much warmer and much denser, and that it expanded. That's it, it's not much more than that. 

Since then space has continued to expand and has become colder.

Based on the theory, scientists have gained a clearer overview of the history of the universe, such as when elementary particles were formed and when atoms, stars and galaxies formed.

If you take the entire observable universe and rewind all the way back, everything fit into a very, very small area. An explosion where the mass explodes in all directions is not an accurate picture of the Big Bang.

The universe itself expands, space itself expands.

So it isn't the galaxies that are moving apart, but space that's expanding.

We can think of it as a ball of dough with raisins. The dough represents space and the raisins are the galaxies. Set the dough to rise, and the raisins will end up further apart, without actually having moved. At the same time, it's true that galaxies also move due to mutual gravitational attraction—that's an additional effect.

A few galaxies are blue-shifting, meaning they're moving towards us. This applies to some nearby galaxies. But over large distances, this effect is eclipsed by Hubble-Lemaître's law, which states how fast galaxies are moving away in proportion to distance. In fact, the distance increases faster than light between points that are extremely far apart.

The universe doesn't expand into anything. Scientists don't believe that the universe has an edge.

That which we call the observable universe is a bubble surrounding us that is 93 billion light-years in diameter. The more distant something is that we look at, the farther back in time we're seeing. We can't observe or measure anything farther away than the distance light has managed to travel towards us since the Big Bang.

Since the universe has been expanding, the observable universe is counterintuitively larger than 14 billion light-years.

But scientists calculate that the universe outside our bubble is much, much larger than that, perhaps infinite.

The universe can be "flat," it appears. That would mean that two light rays would remain parallel and never meet. If you tried to travel to the end of the universe, you would never reach it. The universe goes on infinitely.

If the universe has positive curvature, it could in theory be finite. But then it would be like a kind of strange sphere. If you traveled to the "end" you would end up in the same place you started, no matter which direction you took. It's a bit like being able to travel around the world and ending up back where you started.

In either case, the universe can expand without having to expand into anything.

An infinite universe that's getting bigger is still infinite. A "spherical universe" has no edge.

Myths about big bang - part 1 

Big bang myths - part 2

The big band didn't have  a center.  

If we imagine the Big Bang as an explosion, it's easy to think that it exploded outwards, from a center. That's how explosions work.

But that wasn't the case with the Big Bang. Almost all galaxies are moving away from us, in all directions. It seems like the Earth was the center of the beginning of the universe. But it wasn't.

All other observers would see the same thing from their home galaxy.

The universe is expanding everywhere at the same time. The Big Bang didn't happen in any particular place.

It happened everywhere.

It's true that our entire observable universe was gathered incredibly tightly together in very little space at the beginning of the Big Bang.

But how can the universe be infinite, and at the same time have been so small?

You might read that the universe was smaller than an atom at first and then the size of a football. But that analogy insinuates that space had boundaries in the beginning, and an edge.

There's nothing that says that the universe wasn't already infinite at the Big Bang.

The whole observable universe comes from a tiny little area that you can call a point. But the point next to it has also expanded, and the next point as well. It's just that it's so far away from us that we can't observe it.

Maybe you've heard that the universe began as a singularity. Or that it was infinitely small, hot and so on. That might be true, but a lot of physicists don't think it's a correct understanding.

Singularities are an expression for mathematics that breaks down and can't be described with ordinary physics.

"The universe today is a little bigger than it was yesterday. And it's even a little bigger still than it was a million years ago. The Big Bang theory involves extrapolating this back in time. Then you need a theory for that: and that's the general theory of relativity."

"If I extrapolate all the way back, the universe gets smaller and smaller, it gets denser and denser, and warmer and warmer. Finally you get to a point where it's really small, really hot and dense. That's actually the Big Bang theory: that the universe started in such a condition. That's where you really have to stop.

If you run the general relativity theory all the way back you reach a point of infinitely high density and heat, where the size is zero.

"That's pure mathematical extrapolation beyond what the theory actually allows.

You then come to a point where the energy density and temperatures are so high that we no longer have physical theories to describe them.

https://phys.org/news/2021-03-myths-big.html?utm_source=nwletter&am...

Evidence of new physics at CERN? Why we're cautiously optimistic ab...

When CERN's gargantuan accelerator, the Large Hadron Collider (LHC), fired up ten years ago, hopes abounded that new particles would soon be discovered that could help us unravel physics' deepest mysteries. Dark matter, microscopic black holes and hidden dimensions were just some of the possibilities. But aside from the spectacular discovery of the Higgs boson, the project has failed to yield any clues as to what might lie beyond the standard model of particle physics, our current best theory of the micro-cosmos.

Researchers reveal how a cell mixes its mitochondria before it divides

In a landmark study, a team led by researchers at the Perelman School of Medicine at the University of Pennsylvania has discovered and filmed the molecular details of how a cell, just before it divides in two, shuffles important internal components called mitochondria to distribute them evenly to its two daughter cells. The finding, published in Nature, is principally a feat of basic cell biology, but this line of research may one day help scientists understand a host of mitochondrial and cell division-related diseases, from cancer to Alzheimers and Parkinsons.

Mitochondria are tiny oxygen reactors that are crucial for energy production in cells. It was found in the study that a protein called actin, which is known to assemble into filaments that play a variety of structural roles in cells, also has the important task of ensuring an even distribution of mitochondria prior to cell division. Thanks to this system, the two new cells formed by the division will end up with approximately the same mass and quality of these critical energy producers.

Mitochondria, which can number from a handful to tens of thousands per cell, depending on the cell type, are probably especially important to mix evenly. They are critical for the health of a cell, and contain their own small DNA genomes—new mitochondria can’t be produced in a cell except by the splitting of mitochondria inherited from the mother cell.

https://www.pennmedicine.org/news/news-releases/2021/march/penn-med...

https://researchnews.cc/news/5797/Penn-Medicine-researchers-reveal-...

Ten years later, here’s what Fukushima’s damaged reactors look like today

Why you can't compare Covid-19 vaccines

All meat that has been smoked, salted, cured, dried or canned is considered processed.

Corona waste kills animals throughout the entire world

Biologists started a quest to determine how often and where interactions between corona waste and animals occur. They collected observations from Brazil to Malaysia and from social media to local newspapers and international news websites.

A fox in the United Kingdom, birds in Canada, hedgehogs, seagulls, crabs, and bats - it transpired that all sorts of animals, everywhere, become entangled in face masks.

They found reports about apes chewing on face masks, and about a penguin with a face mask in its stomach. Pets too, especially dogs, were found to swallow face masks. Animals become weakened due to becoming entangled or starve due to the plastic in their stomach. The diversity of animals influenced by corona waste is considerable. "Vertebrates and invertebrates on land, in freshwater, and in seawater become entangled or trapped in corona waste.

 animals use the waste as nest material. For example, coots in Dutch canals use face masks and gloves as nest material. And the packaging from paper handkerchiefs is found in nests too. As such, we even see the symptoms of COVID-19 in animal structures.

https://www.covidlitter.com/

https://eurekalert.org/pub_releases/2021-03/nbc-cwk032421.php

Cells can walk a microscopic tightrope, researchers discover

By offering cells a microscopic “tightrope,” Johns Hopkins University and Virginia Tech scientists have discovered a new and surprising form of cellular movement.

Normally when cells crawling in an organism come in contact with another one another, they reverse and move randomly away from the other cell. But when nanofiber “tightropes” coated with proteins were suspended in a three-dimensional medium for cells to explore, cells either walked past each other to avoid a collision or formed a train moving together along the length of the nanofiber.

The option of walking the line made the typically erratically moving cells much more systemic and predictable, the team found. This new understanding of cellular movement helps explain why some drugs work differently in tests within petri dishes than they do in humans or animals.

The findings just published in the Proceedings of the National Academy of Sciences.

“A cocktail of mechanical engineering, cell biology, physics, and computational modeling reveals cell behaviors not known before

Neuroscientists Detect Confused 'Zombie' Cells in The Human Brain After Death

You'd think once a human is dead, the body would be done doing things; without blood circulation and air, the inner systems would be fast depleted. But due to a weird quirk of biology there are such things as the living dead - living cells, at least, within a done and dusted body.

Some cells within human brains actually increase their activity after we die. These 'zombie' cells ramp up their gene expression and valiantly continue trying to do their vital tasks, as if someone forgot to tell them they're now redundant.

Neurologists recently  watched as these cells stubbornly sprouted new tentacles and busied themselves with chores for hours after death.

Most studies assume that everything in the brain stops when the heart stops beating, but this is not so.

While most gene activity remained stable for the 24 hours,  neuronal cells and their gene activity rapidly depleted. Most remarkably though, glial cells increased gene expression and processes after death. 

While surprising at first, this actually makes a lot of sense, given glial cells, such as waste-eating microglia and astrocytes, are called into action when things go wrong. And dying is about as 'wrong' as living things can go.

That glial cells enlarge after death isn't too surprising given that they are inflammatory and their job is to clean things up after brain injuries like oxygen deprivation or stroke. The scientists then demonstrated the RNA expressed by genes doesn't itself change within 24 hours post death, so any changes in its amount must indeed be due to the continuation of biological processes.

After 24 hours, however, these cells also succumbed and were no longer distinguishable from the degrading tissue that surrounded them.

https://www.nature.com/articles/s41598-021-85801-6

https://www.sciencealert.com/confused-zombie-cells-spring-to-action...

Earth is the only planet known to maintain life. Find out the origins of our home planet and some of the key ingredients that help make this blue speck in space a unique global ecosystem.

Cheap Wine Really Does Taste Better if You Increase The Price Tag

In 2002, one of the most prestigious restaurants in New York City served four Wall Street workers its most expensive bottle of wine: a US$2,000 Mouton Rothschild from 1989.

After it was decanted, the host of the group, a self-reported wine connoisseur, twirled his glass, took a sip and began praising the wine for its purity. Blissfully ignorant, the group had accidentally been given the cheapest bottle of wine on the menu, a Pinot noir valued at just US$18.

This story might sound like a flight of fancy, but growing research on the psychology and neuroscience of wine-tasting suggests mistakes like this are made all the time, although true wine experts often know better.

One of the first studies to explicitly manipulate the price of wine in a realistic tasting session has found a cheap glass becomes far more pleasant when participants are told it has a higher price. 

The experiment was conducted during a public event at the University of Basel in Switzerland. To entertain visitors, the psychology department kindly contributed a wine tasting session.

The event drew 140 participants throughout the day and consisted of a 15-minute session of wine tasting. For each tasting, participants were given their own table and told not to communicate with others also involved in the event - that way their views of the wine wouldn't be influenced.

Six small glasses of wine were then placed on each table, and visitors were told to taste each and every glass in a specific sequence fully randomized for every individual. After each sip, participants were instructed to clear their palates with a swish of water and rate the wine for pleasantness and intensity.

Half the glasses held three different wines without any price information. The remaining glasses contained three different wines of low, medium, and high price with the retail tag clear to see.

In each case, one, two or none of these price-tagged wines had been labeled deceptively. If they were mislabeled, the retail price displayed was either four times higher, or four times lower than the real cost.

When the price of the wine was hidden, researchers found no difference in pleasantness ratings, no matter the actual price.

On the other hand, when the price of wine was mislabeled and deceptively up-priced, pleasantness ratings also increased. For instance, when a low-cost wine was tagged to appear higher in price and exceeded that of the mid-priced wine, participants tended to enjoy the low-cost one more.

"Thus, in wine may lay the truth, but its subjective experience may also lie in the price," the authors conclude. 

Beyond sheer enjoyment, this study is the first to assess the perceived intensity of blind tastings in a real world setting, and it suggests that most wine drinkers are able to determine something different about more expensive wine - they just don't enjoy that difference as much.

part 1

In 2008, researchers used functional MRI to scan participants while they tasted wines that were deceptively labeled. When the price of a wine was increased, participants reportedly enjoyed the flavor more, while intensity ratings remained the same. 

In 2017, follow-up research was able to confirm these results. Scanning the brains of those tasting wines, researchers found increasing the price of the product once again improved subjective reports of flavor without changing its perceived intensity.

What's more, this deceptive pricing increased activity in the medial orbitofrontal cortex of the brain, which is thought to encode for experienced pleasantness. 

"The reward and motivation system is activated more significantly with higher prices and apparently increases the taste experience in this way," said behavioral economist Bernd Weber from the University of Bonn in Germany in 2017. 

Such studies have allowed us to better understand how marketing might influence our brains and our perceptions of pleasantness, but few experiments have replicated these effects in a real-world setting. Previous fMRI studies fed wine to participants through plastic tubes, which means the color and smell were not taken into account, just the price and taste.

This has helped narrow down confounding factors, but it also misses out on several of the ways experts normally judge wine.

The current study is more realistic, measuring both pleasantness and intensity "to get a more comprehensive understanding of the influence of price...."

Unlike previous studies, the authors found decreasing the price of an expensive wine by four fold did not change the overall wine ratings for its pleasantness among laypeople. Only when the price was deceptively increased, did the average person seem to prefer the wine more.

https://www.sciencedirect.com/science/article/abs/pii/S095032932100...

https://www.sciencealert.com/psychologists-find-cheap-wine-tastes-b...

Multiple factors explain the covering behaviour in the green sea urchin, Strongylocentrotus droebachiensis

Although numerous species of sea urchins often cover themselves with small rocks, shells and algal fragments, the function of this covering behaviour is poorly understood. Diving observations showed that the degree to which the sea urchin Strongylocentrotus droebachiensis covers itself in the field decreases with size. We performed laboratory experiments to examine how the sea urchin's covering behaviour is affected by the presence of predators, sea urchin size, wave surge, contact with moving algae blades and sunlight. The presence of two common sea urchin predators did not influence the degree to which sea urchins covered themselves. Covering responses of sea urchins that were exposed to a strong wave surge and sweeping algal blades were significantly greater than those of individuals that were maintained under still water conditions. The degree to which sea urchins covered themselves in the laboratory also tended to decrease with increasing size. Juveniles showed stronger covering responses than adults, possibly because they are more vulnerable to dislodgement and predation. We found that UV light stimulated a covering response, whereas UV-filtered sunlight and darkness did not, although the response to UV light was much weaker than that to waves and algal movement. Our observations suggest that the covering behaviour of S. droebachiensis has evolved as an adaptation to protect it from mechanical injuries associated with abrasion and dislodgement, and to a lesser extent as a defence against UV radiation. The covering behaviour may reduce the sea urchin's ability to move and this would limit its ability to forage and to flee from predators. In this case, the covering behaviour may have evolved as a trade-off between locomotion and limiting environmental stresses.

https://www.sciencedirect.com/science/article/abs/pii/S000334720700....

Image source: Back to sea society blog

Lawyers used sheepskin as anti-fraud device for hundreds of years to stop fraudsters

Medieval and early modern lawyers chose to write on sheepskin parchment because it helped prevent fraud, new analysis suggests.

Experts have identified the species of animals used for British legal documents dating from the 13th to 20th century, and have discovered they were almost always written on sheepskin, rather than goatskin or calfskin vellum.

This may have been because the structure of sheepskin made attempts to remove or modify text obvious.

Sheep deposit fat in-between the various layers of their skin. During parchment manufacture, the skin is submerged in lime, which draws out the fat leaving voids between the layers. Attempts to scrape off the ink would result in these layers detaching—known as delamination—leaving a visible blemish highlighting any attempts to change any writing.

Sheepskin has a very high fat content, accounting for as much as 30 to 50 percent, compared to 3 to 10 percent in goatskin and just 2 to 3 percent in cattle. Consequently, the potential for scraping to detach these layers is considerably greater in sheepskin than those of other animals.

The continuing use of sheepskin over goat or calfskin in later centuries was likely influenced by their greater availability and lower cost.

 Scratching the surface: the use of sheepskin parchment to deter textual erasure in early modern legal deeds, Doherty et al. Heritage Science 2021, DOI: 10.1186/s40494-021-00503-6

https://phys.org/news/2021-03-lawyers-sheepskin-anti-fraud-device-h...

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Frequent consumption of meals prepared away from home associated with an increased risk of death

Dining out is a popular activity worldwide, but there has been little research into its association with health outcomes. Investigators looked at the association between eating out and risk of death and concluded that eating out very frequently is significantly associated with an increased risk of all-cause death, which warrants further investigation. Their results appear in the Journal of the Academy of Nutrition and Dietetics.

Although some restaurants provide high-quality foods, the dietary quality for meals away from home, especially from fast-food chains, is usually lower compared with meals cooked at home. Evidence has shown that meals away from home tend to be higher in energy density, fat, and sodium, but lower in fruits, vegetables, whole grains, and protective nutrients such as dietary fiber and antioxidants.

Emerging, although still limited, evidence suggests that eating out frequently is associated with increased risk of chronic diseases, such as obesity and diabetes and biomarkers of other chronic diseases. This new research shows  that frequent consumption of meals prepared away from home is significantly associated with increased risk of all-cause mortality.

 "Association Between Frequency of Eating Away-From-Home Meals and Risk of All-Cause and Cause-Specific Mortality," Journal of the Academy of Nutrition and Dietetics (2021). DOI: 10.1016/j.jand.2021.01.012

https://medicalxpress.com/news/2021-03-frequent-consumption-meals-h...

Engineers make filters from tree branches to purify drinking water

The interiors of nonflowering trees such as pine and ginkgo contain sapwood lined with straw-like conduits known as xylem, which draw water up through a tree's trunk and branches. Xylem conduits are interconnected via thin membranes that act as natural sieves, filtering out bubbles from water and sap.

Engineers have been investigating sapwood's natural filtering ability, and have previously fabricated simple filters from peeled cross-sections of sapwood branches, demonstrating that the low-tech design effectively filters bacteria.

Now they have advanced the technology and shown that it works in real-world situations. They have fabricated new xylem filters that can filter out pathogens such as E. coli and rotavirus in lab tests, and have shown that the filter can remove bacteria from contaminated spring, tap, and groundwater. They also developed simple techniques to extend the filters' shelf-life, enabling the woody disks to purify water after being stored in a dry form for at least two years.

The researchers took their techniques to India, where they made xylem filters from native trees and tested the filters with local users. Based on their feedback, the team developed a prototype of a simple filtration system, fitted with replaceable xylem filters that purified water at a rate of one liter per hour.

Their results, published today in Nature Communications, show that xylem filters have potential for use in community settings to remove bacteria and viruses from contaminated drinking water.

Krithika Ramchander, Megha Hegde, Anish Paul Antony, Luda Wang, Kendra Leith, Amy Smith, Rohit Karnik. Engineering and characterization of gymnosperm sapwood toward enabling the design of water filtration devices. Nature Communications, 2021; 12 (1) DOI: 10.1038/s41467-021-22055-w

https://techxplore.com/news/2021-03-filters-tree-purify.html?utm_so...

Scientists find evidence that novel coronavirus infects the mouth's cells

An international team of scientists has found evidence that SARS-CoV-2, the virus that causes COVID-19, infects cells in the mouth. While it's well known that the upper airways and lungs are primary sites of SARS-CoV-2 infection, there are clues the virus can infect cells in other parts of the body, such as the digestive system, blood vessels, kidneys and, as this new study shows, the mouth. The potential of the virus to infect multiple areas of the body might help explain the wide-ranging symptoms experienced by COVID-19 patients, including oral symptoms such as taste loss, dry mouth and blistering. Moreover, the findings point to the possibility that the mouth plays a role in transmitting SARS-CoV-2 to the lungs or digestive system via saliva laden with virus from infected oral cells. A better understanding of the mouth's involvement could inform strategies to reduce viral transmission within and outside the body.

In salivary gland tissue from one of the people who had died, as well as from a living person with acute COVID-19, the scientists detected specific sequences of viral RNA that indicated cells were actively making new copies of the virus—further bolstering the evidence for infection.

Once the team had found evidence of oral tissue infection, they wondered whether those tissues could be a source of the virus in saliva. This appeared to be the case. In people with mild or asymptomatic COVID-19, cells shed from the mouth into saliva were found to contain SARS-CoV-2 RNA, as well as RNA for the entry proteins.

To determine if virus in saliva is infectious, the researchers exposed saliva from eight people with asymptomatic COVID-19 to healthy cells grown in a dish. Saliva from two of the volunteers led to infection of the healthy cells, raising the possibility that even people without symptoms might transmit infectious SARS-CoV-2 to others through saliva.

the study's findings suggest that the mouth, via infected oral cells, plays a bigger role in SARS-CoV-2 infection than previously thought.

Nature Medicine (2021). DOI: 10.1038/s41591-021-01296-8

https://medicalxpress.com/news/2021-03-scientists-evidence-coronavi...

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Researchers develop 15-minute test to assess immune response

Researchers from Critical Analytics for Manufacturing Personalized-Medicine (CAMP) have developed a new label-free immune profiling assay that profiles the rapidly changing host immune response in case of infection, in a departure from existing methods that focus on detecting the pathogens themselves, which can often be at low levels within a host. This novel technology presents a host of advantages over current methods, being both much faster, more sensitive and accurate.

In many cases, the main culprit behind disease manifestation, severity of infection, and patient mortality is an overly aggressive host immune response.

For instance, the Spanish Flu pandemic of 1918 resulted in a disproportionately high number of deaths among otherwise healthy young adults. This has been attributed to the now well-studied phenomenon of cytokine storms, which precipitate the rapid release of immune cells and inflammatory molecules and are brought on by a hyper-aggressive host immune response. In a more recent example, cases of severe COVID-19 infection often result in death via sepsis and a dysregulated immune response, while current risk stratification methods based on age and comorbidity remain a significant challenge and can be inaccurate. Moreover, current COVID-19 testing does not prognose the severity of the immune response and can thus lead to inefficient deployment of resources in healthcare settings.

In cases of acute infection, the status of a patient's immune response can often be volatile and may change within minutes. Hence, there exists a pressing need for assays that are able to rapidly and accurately inform on the state of the immune system. This is particularly vital in early triage among patients with acute infection and prediction of subsequent deterioration of disease. In turn, this will better empower medical personnel to make more accurate initial assessments and deliver the appropriate medical response. This can ensure timely intervention in the emergency department (ED) and prevent admission to the intensive care unit (ICU).

The new assay developed by SMART researchers focuses on profiling the rapidly changing host inflammatory response, which in a hyper-aggressive state, can lead to sepsis and death. A 15-minute label-free immune profiling assay from 20 µL of unprocessed blood using unconventional L and inverse-L shaped pillars of DLD microfluidic technology was developed, functioning as a sensitive and quantitative assay of immune cell biophysical signatures in relation to real-time activation levels of WBCs. As WBCs are activated by various internal or external triggers, the assay can sensitively measure both the extent and direction of these changes, which in turn reflect a patient's current immune response state. As such, the new assay developed by SMART researchers is able to accurately and quickly assess patients' immune response states by profiling immune cell size, deformability, distribution, and cell counts.

Significantly, the new assay provides considerable advantages over existing methods of profiling the immune system and its activity. These include measuring leukocyte gene expression, cell-surface biochemical markers, and blood serum cytokine profile.

Kerwin Kwek Zeming et al. Label‐Free Biophysical Markers from Whole Blood Microfluidic Immune Profiling Reveal Severe Immune Response Signatures, Small (2021). DOI: 10.1002/smll.202006123

https://phys.org/news/2021-03-minute-immune-response.html?utm_sourc...

Scientist discovers a new type of 'bi-molecule' with applications for quantum sensors

Researchers found a new type of bi-molecule formed from two nitric oxide (NO) molecules, both in their ground state and in the Rydberg electronic state.

This new type of bi-molecule is the result of the union of two molecules of nitric oxide (NO) whose structure is arranged in such a way that the NO and NO⁺ ion are located in opposite poles. The electron orbits around both, acting like a "glue" that binds the bi-molecule. In addition, its size corresponds to between 200 and 1,000 times that of NO, and its lifetime is long enough to enable its observation and experimental control, as these fragile systems are easily manipulated by means of very weak electric fields.

This type of bi-molecule enables researchers to implement and study chemical reactions at low temperatures from a quantum perspective and facilitates the investigation of intermolecular interactions at large distances, since they coexist at low temperatures.

Rosario González-Férez et al. Ultralong-Range Rydberg Bimolecules, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.043401

https://phys.org/news/2021-03-scientist-bi-molecule-applications-qu...

New Way of Identification of a Place and Tracking

Meet the zeptosecond, the shortest unit of time ever measured

Scientists have measured the shortest unit of time ever: the time it takes a light particle to cross a hydrogen molecule. 

That time, for the record, is 247 zeptoseconds. A zeptosecond is a trillionth of a billionth of a second, or a decimal point followed by 20 zeroes and a 1. Previously, researchers had dipped into the realm of zeptoseconds; in 2016, researchers reporting in the journal Nature Physics used lasers to measure time in increments down to 850 zeptoseconds. This accuracy is a huge leap from the 1999 Nobel Prize-winning work that first measured time in femtoseconds, which are millionths of a billionths of seconds. 

It takes femtoseconds for chemical bonds to break and form, but it takes zeptoseconds for light to travel across a single hydrogen molecule (H2).

https://www.space.com/zeptosecond-shortest-time-unit-measured.html

A technique to track Earth’s subtle movements with orbiting radars is heating up

Scientists Created an Artificial Early Embryo From Human Skin Cells

We all know how human reproduction works: sperm meets egg, fertilized egg kicks off its journey, transforms into a human embryo, then becomes a fetus and ultimately a baby.

But what if boy meets girl isn’t the only way?

Last week, two studies in Nature torpedoed the classic narrative of the beginning of life. Two independent teams coaxed ordinary skin cells into a living cluster that resembled a fertilized human egg—and the very first stages of a developing human embryo.

To be clear, the teams did not engineer an artificial embryo that could develop into a viable baby. Rather, they replicated what happens during the first four days after an egg has been fertilized; it develops into a ball of cells called a blastocyst, the first station towards a full-formed baby.

Though they didn’t get beyond the blastocyst stage, both models are by far the most complete replicas of an early human embryo to date. They don’t just contain cells that grow into a baby, but also all of the supporting structures. Within just 10 days inside a Jello-like incubator, the reverse-engineered cells showed traits astonishingly similar to their natural counterparts. For example, the artificial embryos generated cells that form the placenta, which is critical for a viable embryo that could, in theory, develop further or even until birth.

It’s the first complete model of the human early embryo. 

These studies offer a new window into the first days of pregnancy, and may provide insight into previously inexplicable infertility or pregnancy loss without experimenting on human embryos.

Yet the sophistication of these cells is raising concerns. For now, because the artificial embryos differ from natural ones in several ways, scientists don’t expect them to have the ability to grow into complete embryos. As the technologies further refine, however, it may become possible to grow artificial human embryos for longer periods, putting the technology on a collision course with debates about the beginning of life.

The first 14 days of building a human are a mystery.

Scientists know that during a pregnancy, a fertilized egg develops into a blastocyst around day four, and it then implants around day eight. Around this time, something “magical” happens within the blastocyst, such that it churns out cells that eventually develop into the placenta, and others that give rise to a fetus.

The problem? This initial stage is incredibly hard to study. Thus far, scientists have relied on discarded human embryos in the lab—often from IVF outcasts—which can be grown to 13 days according to ethics guidelines

https://singularityhub.com/2021/03/23/scientists-created-an-artific...

How teeth sense the cold

For people with sensitive teeth, eating cold foods is hell. It's a unique kind of pain. It's just excruciating. an international team of scientists have figured out how teeth sense the cold and pinpointed the molecular and cellular players involved. In both mice and humans, tooth cells called odontoblasts contain cold-sensitive proteins that detect temperature drops, the team reports March 26, 2021, in the journal Science Advances. Signals from these cells can ultimately trigger a jolt of pain to the brain.

The work offers an explanation for how one age-old home remedy eases toothaches. The main ingredient in clove oil, which has been used for centuries in dentistry, contains a chemical that blocks the "cold sensor"protein.

Developing drugs that target this sensor even more specifically could potentially eliminate tooth sensitivity to cold. Once you have a molecule to target, there is a possibility of treatment.

 L. Bernal el al., "Odontoblast TRPC5 channels signal cold pain in teeth," Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abf5567

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Teeth decay when films of bacteria and acid eat away at the enamel, the hard, whitish covering of teeth. As enamel erodes, pits called cavities form. Roughly 2.4 billion people—about a third of the world's population—have untreated cavities in permanent teeth, which can cause intense pain, including extreme cold sensitivity.

https://medicalxpress.com/news/2021-03-teeth-cold.html?utm_source=n...

The cell signal of death

Scientists have revealed molecular mechanisms involved in eliminating unwanted cells in the body. A nuclear protein fragment released into the cytoplasm activates a plasma membrane protein to display a lipid on the cell surface, signaling other cells to get rid of it. The findings were published in the journal Molecular Cell.

Every day, 10 billion cells die and are engulfed by blood cells called phagocytes. If this didn't happen, dead cells would burst, triggering an auto-immune reaction. It is important to understand how dead cells are eliminated as part of our body's maintenance.

Scientists already know that dead cells display an 'eat me' signal on their surface that is recognized by phagocytes. During this process, lipids are flipped between the inner and outer parts of the cell membrane via a variety of proteins called scramblases, mostly using a protein called Xkr4. It was found that found that a nuclear protein fragment activates Xkr4 to display the 'eat me' signal to phagocytes.

Specifically, the scientists found that cell death signals lead to an enzyme cutting a nuclear protein called XRCC4. A fragment of XRCC4 leaves the nucleus, activating Xkr4, which forms a dimer: the linking of identical pieces into configurations. Both XRCC4 binding and dimer formation are necessary for Xkr4 to ultimately transfer lipids on the cell surface to alert phagocytes.

Xkr4 is only one of the scrambling proteins. Others are activated much faster during cell death. 

Masahiro Maruoka et al, Caspase cleavage releases a nuclear protein fragment that stimulates phospholipid scrambling at the plasma membrane, Molecular Cell (2021). DOI: 10.1016/j.molcel.2021.02.025

https://phys.org/news/2021-03-cell-death.html?utm_source=nwletter&a...

Direct observations confirm that humans are throwing Earth's energy budget off balance

Earth is on a budget—an energy budget. Our planet is constantly trying to balance the flow of energy in and out of Earth's system. But human activities are throwing that off balance, causing our planet to warm in response.

Radiative energy enters Earth's system from the sunlight that shines on our planet. Some of this energy reflects off of Earth's surface or atmosphere back into space. The rest gets absorbed, heats the planet, and is then emitted as thermal radiative energy the same way that black asphalt gets hot and radiates heat on a sunny day. Eventually this energy also heads toward space, but some of it gets re-absorbed by clouds and greenhouse gases in the atmosphere. The absorbed energy may also be emitted back toward Earth, where it will warm the surface even more.

Adding more components that absorb radiation—like greenhouse gases—or removing those that reflect it—like aerosols—throws off Earth's energy balance, and causes more energy to be absorbed by Earth instead of escaping into space. This is called a radiative forcing, and it's the dominant way human activities are affecting the climate.

Climate modeling predicts that human activities are causing the release of greenhouse gases and aerosols that are affecting Earth's energy budget. Now, a NASA study has confirmed these predictions with direct observations for the first time: radiative forcings are increasing due to human actions, affecting the planet's energy balance and ultimately causing climate change. The paper was published online March 25, 2021, in the journal Geophysical Research Letters.

It was found that  human activities have caused the radiative forcing on Earth to increase by about 0.5 Watts per square meter from 2003 to 2018. The increase is mostly from greenhouse gases emissions from things like power generation, transport and industrial manufacturing. Reduced reflective aerosols are also contributing to the imbalance.

 Ryan J. Kramer et al. Observational evidence of increasing global radiative forcing, Geophysical Research Letters (2021). DOI: 10.1029/2020GL091585

https://phys.org/news/2021-03-humans-earth-energy.html?utm_source=n...

How microorganisms can help us get to net negative emissions

Many of the common items we use in our everyday lives—from building materials to plastics to pharmaceuticals—are manufactured from fossil fuels. To reduce our reliance on fossil fuels and reduce greenhouse gas emissions, society has increasingly tried turning to plants to make the everyday products we need. For example, corn can be turned into corn ethanol and plastics, lignocellulosic sugars can be turned into sustainable aviation fuels, and paints can be made from soy oil.

But what if plants could be removed from the picture, eliminating the need for water, fertilizer, and land? What if microbes could instead be harnessed to make fuels and other products? And what if these microbes could grow on carbon dioxide, thus simultaneously producing valuable goods while also removing a greenhouse gas from the atmosphere, all in one reactor? 

Scientists have made good progress in turning this technology into reality. A project developed by them project combines biology and electrochemistry to produce complex molecules, all powered by renewable energy. With carbon dioxide as one of the inputs, the system has potential to remove heat-trapping gases from the atmosphere, or in other words, a negative emissions technology (NET).

https://phys.org/news/2021-03-microorganisms-net-negative-emissions...

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Cooling homes without warming the planet

As global temperatures are increasing, demand for air conditioners is expected to triple by 2050. The surge will multiply what is already a major source of greenhouse gas emissions: Air conditioning is currently responsible for almost 20 percent of electricity use in buildings around the world.

Now the startup Transaera is working to curb those energy demands with a more efficient air conditioner that uses safer refrigerants to cool homes. The company believes its machine could have one-fifth the impact on the climate when compared to traditional ACs. 

The thing about air conditioning is the basic technology hasn't changed much since it was invented 100 years ago. 

That will change rapidly if Transaera's small team is successful. The company is currently a finalist in a global competition to redesign the air conditioner. The winner of the competition, named the Global Cooling Prize, will get $1 million to commercialize their machines.

At the heart of Transaera's design is a class of highly porous materials called metal organic frameworks, or MOFs, that passively pull moisture from the air as the machine works. MOFs have a lot of potential applications, but the thing that's held them back is unit economics and the inability to make them in a cost-effective way at scale. What Transaera aims to do is be the first to commercialize MOFs at scale and lead the breakthrough that brings MOFs into the public domain.

Most people think air conditioners only cool the air in a space, but they also dry the air they're cooling. Traditional machines use something called an evaporator, a cold coil to pull water out of the air through condensation. The cold coil must be made much colder than the desired temperature in the room in order to collect moisture. Pulling moisture out of the air takes up about half of the electricity used by traditional air conditioners.

Transaera's MOFs passively collect moisture as air enters the system. The machine's waste heat is then used to dry the MOF material for continuous reuse.

https://news.mit.edu/2021/transaera-air-conditioner-0326

https://phys.org/news/2021-03-cooling-homes-planet.html?utm_source=...

Molecule attacks coronavirus in a novel way

Scientists at the University of Bonn and the caesar research center have isolated a molecule that might open new avenues in the fight against SARS coronavirus 2. The active ingredient binds to the spike protein that the virus uses to dock to the cells it infects. This prevents them from entering the respective cell, at least in the case of model viruses. It appears to do this by using a different mechanism than previously known inhibitors. The researchers therefore suspect that it may also help against viral mutations. The study will be published in the journal Angewandte Chemie but is already available online.

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Differences in snake venom composition raise questions about treatment

Snakebite kills around 58,000 Indians annually, and a majority of snakebites that lead to death or disability are attributed to the 'big four' of Indian snakes—the Russell's viper (Daboia russelii), one of the deadliest snake species in the world, the spectacled cobra (Naja naja), the common krait (Bungarus caeruleus) and the saw-scaled viper (Echis carinatus). Commercial antivenom treatment for snakebite does not always prove effective, and despite the severity of the problem in India, few efforts have been made to understand why this is so.

Octopuses, like humans, sleep in two stages

When researchers filmed captive Octopus insularis octopuses sleeping in their tanks, they recorded alternating phases of “quiet sleep”, in which the creatures were pale and still, followed by short spurts of “active sleep”, in which their skin turned darker and stiffened, they moved their eyes, and muscular twitches contracted their suckers. In mammals, birds and perhaps in reptiles, this two-stage sleep pattern is thought to help consolidate memories and clear waste from the brain. Because our last common ancestor with octopuses lived more than 500 million years ago, it seems that the molluscs evolved this sleeping pattern separately, so its function remains unclear.

https://www.sciencemag.org/news/2021/03/octopuses-humans-sleep-two-...

The physics of the stuck Suez ship

High winds combined with ship–bank interaction effects might have sent the huge container ship Ever Given into a spin in the shallow waters of the Suez Canal, suggests hydrodynamicist Evert Lataire. The boat has been wedged fast in the essential shipping route since Tuesday. Bank effects occur in restricted navigation areas, where water displaced by a ship has nowhere to go. As a ship passes close to the side of a shallow channel, the water in the gap must speed up, causing the stern to pull into the bank and the bow to be pushed away. In the case of the Ever Given, the effect could have caused the ship to veer into the opposite bank, as shown in this VesselFinder video.

Excess blood sugar promotes clogging of arteries: study

Excess sugar in the blood, the central feature of diabetes, can react with immune proteins to cause myriad changes in the immune system, including inflammatory changes that promote atherosclerosis, according to a new study from scientists at Weill Cornell Medicine and University of Massachusetts Medical School. The study, published March 15 in the journal Immunity, advances the field of diabetes research by revealing molecular pathways through which the disorder may cause other serious health problems for patients. In principle, these newly revealed pathways could be targeted with future diabetes drugs.

Testing the Best Bomb Detectors

It's snowing plastic

The snow may be melting, but it is leaving pollution behind in the form of micro- and nano-plastics according to a McGill study that was recently published in Environmental Pollution. The pollution is largely due to the relatively soluble plastics found in antifreeze products (polyethylene glycols) that can become airborne and picked up by the snow.

The researchers used a new technique that they have developed to analyze snow samples collected in April 2019 in Montreal for both micro- and nano-sized particles of various plastics. The McGill technique is orders of magnitude more sensitive than any of the other current methods used for tracing plastic in the environment. It allows scientists to detect ultra-trace quantities of many of the most common soluble and insoluble plastics in snow, water, rainfall, and even in soil samples once they have been separated – down to the level of a picogram (or one trillionth of a gram). It is based on using nano-structured mass spectrometry and, unlike other techniques currently in use, the new technique is both recyclable and based on sustainable practices.

https://researchnews.cc/news/5835/It-s-snowing-plastic#.YF7xN68zbIU

First Report of Horizontal Gene Transfer Between Plant and Animal

Whiteflies overcome a toxin in plants they eat through the use of the plant’s own genetic protection, likely ferried from plant to insect millions of years ago by a virus.

In the first known example of horizontal gene transfer between a plant and an animal, a common pest known as the whitefly (Bemisia tabaci) acquired a gene from the one of the various plants it feeds on, researchers reported today (March 25) in Cell. The gene, BtPMaT1, protects the insects from phenolic glycosides, toxins that many plants produce to defend themselves against such pests, thus allowing the whiteflies to feast.

J. Xia et al., “Whitefly hijacks a plant detoxification gene that neutralizes plant toxins,” Cell, doi:10.1016/j.cell.2021.02.014, 2021.

Corals may need their predators' poop

Scientists Discover Deep-Sea Microbes That Are Invisible to Our Immune System

Bacteria collected from more than a mile below the surface of the Pacific Ocean may have just blown one of immunology's longest-held assumptions clean out of the water.

The bacteria are so alien to humans that our immune cells do not even register that they exist, making them completely invisible to our immune systems.

This totally contradicts one of the classic tenets of immunology – that the human immune system evolved to be able to sense every single microbe so it could catch the infectious ones.

"The idea was that the immune system is a generalist, it doesn't care if something was a threat or not, it just got rid of it. But no one had really pressure tested that assumption until now.

To test this, the researchers had to find bacteria that were unlikely to have ever had previous contact with mammalian immune systems. They chose a spot deep in the central Pacific Ocean, in the Phoenix Islands Protected Area in Kiribati, 1,650 miles (2,655 kilometers) southwest of Hawaii.

"It's not just the deep ocean, but the most deep, ancient, remote, and protected part of the ocean. It's 4,000 meters (13,100 feet) deep; there are no resident mammals; and it's on the equatorial space where there wouldn't even be any whales for there to be any whale falls. 

Once there, researchers used a remote submarine to collect marine bacteria from samples of water, sponge, sea star, and sediment, before growing them into 117 culturable species.

After identifying the features of their bacteria, the researchers introduced 50 of the strains to mouse and human immune cells. To their surprise, they found that 80 percent of the microbes, mostly belonging to the genus Moritella, escaped detection. The receptors on the mammalian bone marrow immune cells used in the study were incapable of seeing them.

To try to narrow down which features of the marine bacteria made them invisible to our immune receptors, the team also exposed the mouse and human cells to just one specific part of the bacterial cell wall, called the lipopolysaccharide (LPS). Mammalian immune systems are known to use this outermost part of the bacterial cell wall to recognize so-called gram-negative bacteria and put up a fight.

The researchers found that the mammal cells' receptors were blind to the LPS on its own, too.

"The LPS molecules looked similar to what you'd find in bacteria on land, but many of them were completely silent," Kagan said. "This is because the lipid chains on the LPS turned out to be much longer than the ones we're used to on land, but we still don't know why that means they can go undetected."

Despite their spooky ability to evade detection, the researchers said that deep-sea bacteria don't pose any risk of infecting people. 

Firstly, they haven't evolved to evade mammalian immune systems, so if there was any pathogenicity it would be accidental. The second reason it's highly unlikely is that the temperatures, pressures, and the chemical environments inside our bodies are so different to what you'd find at the bottom of the ocean. These bacteria aren't happy for more than a few minutes outside of their normal habitat.

https://immunology.sciencemag.org/content/6/57/eabe0531

https://www.sciencealert.com/scientists-discover-deep-sea-microbes-...

Study confirms evolutionary link between social structure and selfishness

Researchers revealed that less selfish behavior evolved under living conditions that forced individuals to interact more frequently with siblings. More selfishness makes you not to interact with your siblings. While the finding was verified with insect experiments,  the evolutionary principle could be applied to study any species, including humans.

In laboratory tests, researchers showed they could predictably increase or decrease rates of cannibalism in Indian meal moths by decreasing how far individuals could roam from one another, and thus increasing the likelihood of "local" interactions between sibling larvae. In habitats where caterpillars were forced to interact more often with siblings, less selfish behavior evolved within 10 generations.

In societies or cultures that live in big family groups among close relatives, for example, you might expect to see less selfish behavior, on average, than in societies or cultures where people are more isolated from their families and more likely to be surrounded by strangers because they have to move often for jobs or other reasons.

Mike Boots et al, Experimental evidence that local interactions select against selfish behaviour, Ecology Letters (2021). DOI: 10.1111/ele.13734

https://phys.org/news/2021-03-evolutionary-link-social-selfishness....

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