From polar bears to groundwater, nature is riddled with 'forever chemicals'

They didn't exist a century ago but today PFAS "forever chemicals" contaminate the environment from groundwater to Antarctic snow to turtle eggs, and concern over their possible toxicity is growing.

Lawsuits and regulations targeting per- and polyfluoroalkyl substances (PFAS) are multiplying, with France becoming the latest jurisdiction to consider tough new curbs on these long-life substances.

On Thursday, a French legislator will introduce a bill to address what he calls the health "emergency" posed by exposure to PFAS in the environment.

Widely used in everyday items, highly durable, and very slow to break down, PFAS have been detected in water, air, fish and soil in the remotest corners of the globe.

No ecosystem has escaped this contamination. 

These molecules—the best known of which gave birth to non-stick Teflon—were developed after World War II to give packaging, paints and coatings exceptional resistance to water or heat.

This very quality turned out to be a particular problem for oceans. Being persistent compounds—which do not degrade and are mobile—they end up in the marine environment, which always ultimately is the receptacle for contamination.

A study published in January by the American Chemical Society, a nonprofit scientific organisation, said that PFAS had ben detected in the Arctic Ocean at a depth of 3,000 feet (914 metres).

IFREMER recently examined the diets of two fish—sea bass and sole—in the Seine estuary of France and discovered PFAS riddled throughout the food chain.

From the tiny zooplankton eaten by shellfish, which are consumed by smaller fish and ultimately larger predators, PFAS lurked at every step along the way.

A 2022 study in Australia established the transmission of PFAS from female turtles to their unborn offspring, while other research found traces in polar bear livers and birds, seals and other animals.

A wealth of scientific research has demonstrated the pervasive reach of PFAS in nature, but possible harms to people and the planet have been harder to definitively establish.

More than 20 years ago, a study in the US concluded that once inside the body PFAS may be able to reach the brain of vertebrates and affect the nervous system.

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Studies have since shown that exposure to some PFAS—there are at least 4,000 chemical compounds in the family—may be linked to serious health effects in humans and animals.
The European Union is considering a blanket Europe-wide ban on PFAS from as early as 2026 while New Zealand will outlaw their use in cosmetic products by 2027.

In April, a US court approved a litigation settlement in which the conglomerate 3M agreed to pay billions to test for and filter out PFAS in public water supply.

In February, US regulators said materials containing PFAS would no longer be used to package microwave popcorn or other greasy foods.
Establishing the possible long-term harms of PFAS exposure is difficult when considering such a kaleidoscope of chemicals, many of which are industry secrets.
Those known to scientists are "only the tip of the iceberg".
Examining the full spectrum of chemicals is critical to better understanding their impact on nature.
A wild organism is never exposed to a single PFAS, but to a cocktail of PFAS.

Source: AFP and other news agencies

Why do we need a leap second? A physicist explains what is messing with the Earth's rotation
Meltwater from the polar ice caps, combined with the shifting spin of Earth's core, is messing with the Earth's rotation to the point that we might need to adjust for a "negative leap second."

The effects of climate change can be seen everywhere, in the global refugee crisis, an even worse allergy season and, now, even in the very concept of time.

Scientists have recently pinpointed how meltwater from the polar ice caps is throwing off Earth's rotation to the point that those who really care about precision timekeeping might have to implement a "negative leap second."

Does that mean our days will suddenly be 25 hours long? No, but even a change of one second is significant in a world that is built on digital systems, like GPS, that rely on precise timekeeping to operate correctly.

The core, the crust, oceans, climate change, glacial isostatic adjustment –– all of these factors [are] contributing to a change in the Earth's rate of rotation at a measurable pace, something that would accumulate a second per year or something like that.

There are two primary methods of timekeeping. Universal Coordinated Time (UTC), also known as astronomical time because it's based on Earth's rotation and position among the stars, has long been used as the global standard for clocks and timekeeping. It's what time zones are based on and what most people think of as "time."

However, Earth's rotation is not exactly a steady drumbeat. It's actually always changing as the sun, moon and Earth's gravitational forces, as well as Earth's tides and even the rotation of its core, play off one another.

To account for this, timekeepers—requiring a more exacting standard—started using atomic time, or International Atomic Time, to come up with the exact speed that our clocks tick. This measure varies so little that it might as well be static. In 1958, the international time keeping community agreed to synchronize both UTC and TAI. However, in 1972, scientists noticed that Earth's rotation was starting to slow ever so slightly, effectively making the days slightly longer. As a result, atomic and astronomical time began to diverge slowly but steadily. To keep them in sync—an increasing necessity as more and more digital systems, like GPS satellites, require even more exacting levels of precision—the "leap second" was created.

there are several factors responsible for the declining pace of Earth's rotation, including what is called tidal locking.

The moon pulls on Earth, Earth pulls on the moon and over time the effect of that is for the Earth to slow down in a minuscule—like one part in 10 billion—but non negligible way.

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Glacial melt that has been taking place since the Ice Age and, more recently, polar ice melt stemming from manmade climate change have also contributed to the Earth's slowing rotation.

In both cases, the meltwater disperses, creating a mass of water around the equator, while, at the same time, the land previously trapped under ice at the poles springs back up.

Those two forces together make it more difficult for the Earth to rotate, meaning the UTC day is technically longer. This phenomenon has been observed for decades.

"As the glaciers melt and as Earth slowly springs back and as mass that was once at the poles gets redistributed to the equators—because liquid spreads more easily, liquid responds to being spun—the rotation rate of the Earth slows down.

However, more recently scientists have discovered that Earth is not slowing down anymore. In fact, it's starting to speed up ever so slightly. Leap seconds were added almost every year between 1972 and 1999 to adjust for Earth's slowing rotation. But there have only been four added in the last 23 years, and the last time a leap second was added was in 2016.

What scientists have found is that although climate change is "applying the brakes", the liquid part of Earth's core is also slowing down, affecting how fast the surface of the planet spins.

"The core of the Earth, the liquid part, rotates too, and it sometimes just experiences random changes, random fluctuations.

Right now, the core of the Earth in the last few decades has randomly slowed down and by a complicated series of interactions between the liquid part of the core and the mantle and the crust, or the solid part of the Earth, the crust is spinning faster. This random change in the core's rotation, specifically a slowing down in the rate of rotation, translates into a speeding up of the Earth's surface rotating, which would have the effect of shortening days.

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In a few years, it could result in implementing a negative leap second to keep atomic and astronomical time in sync, although the impacts of polar ice melt could end up delaying our need to shift the clocks from 2026 to 2029.

Would adjusting the clocks by a second make that much of a difference? It could impact global systems in a major way.

Although our computer infrastructure is equipped to handle positive leap seconds, essentially none of our networks or web services are equipped for negative leap seconds.

They don't know how to go from 12:00:03 to 12:00:02. This is essentially on par with the Y2K bug where you had to reprogram everything to allow for four-digit years.

Similar to Y2K,  it likely wouldn't actually end up causing catastrophe. Although it could impact the precision timekeeping community and atomic time, the alternative to letting "a couple of seconds float" is "reprogramming the internet." In that case, a little lost time might not be a bad thing.

A reason for right- or left-handedness
Researchers examined rare genetic variants from a database of more than 350,000 individuals’ genetic data to hunt for clues for what influences handedness in humans. Their findings implicate tubulins — proteins that build cells’ internal skeletons.

The results, published on 2 April in Nature Communications1, were obtained specifically at protein-coding parts of the DNA, and add to previous studies that linked genetic variations with handedness .
During the embryonic stage of human development, the left and right brain hemispheres get wired differently, which in part determines innate behaviours, such as where we lean when we hug someone, on which side of our mouth we tend to chew our food and, most prominently, which hand is our dominant one. This turns out to be the left hand for around 10% of the human population.

Because most people have a clear preference for one hand over the other, finding genes linked to handedness can provide clues for the genetic basis of the brain’s left–right asymmetry.
Previous studies looking at genome-wide data from UK Biobank2 found 48 common genetic variants associated with left-handedness, which were mostly in non-coding regions of the DNA. These included sections that could control the expression of genes related to tubulins. These proteins assemble into long, tube-like filaments called microtubules, which control the shapes and movements of cells.
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But Clyde Francks, a geneticist and neuroscientist at the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands, and his team looked for genetic variants in protein-coding sequences. Their analysis of 313,271 right-handed and 38,043 left-handed individuals’ genetic data, from the UK Biobank, uncovered variants in a tubulin gene, dubbed TUBB4B, which were 2.7 times more common in left-handed people than in right-handers.

Microtubules could influence handedness because they form cilia — hair-like protrusions in cell membranes — which can direct fluid flows in an asymmetric way during development.

In spite of affecting only a small proportion of the people in this considerable data set, rare variants “can give clues to developmental mechanisms of brain asymmetry in everyone”, these findings pave the way for future work to determine how microtubules, which themselves have a molecular ‘handedness’, can give an “asymmetric twist” to early brain development.

https://www.nature.com/articles/s41467-024-46277-w?utm_source=Live+...

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Cancer-busting vaccines are coming: here's how they work

Scientists identify rare gene variants which confer up to 6-fold increase in risk of obesity

A study led by Medical Research Council (MRC) researchers has identified genetic variants in two genes that have some of the largest impacts on obesity risk discovered to date.

The discovery of rare variants in the genes BSN and APBA1 are some of the first obesity-related genes identified for which the increased risk of obesity is not observed until adulthood.

The researchers used UK Biobank and other data to perform whole exome sequencing of body mass index (BMI) in over 500,000 individuals.

They found that genetic variants in the gene BSN, also known as Bassoon, can raise the risk of obesity as much as six times and was also associated with an increased risk of non-alcoholic fatty liver disease and of type 2 diabetes.

The Bassoon gene variants were found to affect 1 in 6,500 adults.

Previous research has identified several obesity-associated gene variants conferring large effects from childhood, acting through the leptin-melanocortin pathway in the brain, which plays a key role in appetite regulation.

However, while both BSN and APBA1 encode proteins found in the brain, they are not currently known to be involved in the leptin-melanocortin pathway. In addition, unlike the obesity genes previously identified, variants in BSN and APBA1 are not associated with childhood obesity. 

This has led the researchers to think that they may have uncovered a new biological mechanism for obesity, different to those we already know for previously identified obesity gene variants.

Based on published research and laboratory studies they report in this paper, which indicate that BSN and APBA1 play a role in the transmission of signals between brain cells, the researchers suggest that age-related neurodegeneration could be affecting appetite control.

For this study, the researchers worked closely with AstraZeneca to replicate their findings in existing cohorts using genetic data from individuals from Pakistan and Mexico. This is important as the researchers can now apply their findings beyond individuals of European ancestry.

If the researchers can better understand the neural biology of obesity, it could present more potential drug targets to treat obesity in the future.

Protein-truncating variants in BSN are associated with severe adult-onset obesity, type 2 diabetes and fatty liver disease, Nature Genetics (2024). DOI: 10.1038/s41588-024-01694-x

Automated bioacoustics: Researchers are listening in on insects to better gauge environmental health

Recent research evaluates how well machine learning can identify different insect species by their sound, from malaria-carrying mosquitoes and grain-hungry weevils to crop-pollinating bees and sap-sucking cicadas.

Listening in on the insect world gives us a way to monitor how populations of insects are shifting, and so can tell us about the overall health of the environment. The study,  published  in the Journal of Applied Ecology, suggests that machine and deep learning are becoming the gold standards for automated bioacoustics modeling, and that ecologists and machine-learning experts can fruitfully work together to develop the technology's full potential.

Insects rule the world. Some are disease vectors and pests, while others pollinate nutritious crops and cycle nutrients. They're the foundation of ecosystems around the world, being food for animals ranging from birds and fishes to bears and humans. Everywhere we look, there are insects, but it's difficult to get a sense of how their populations are changing.

Indeed, in the age of chemical pesticides, climate change and other environmental stressors, insect populations are changing drastically. Some species—like the pollinators that are annually responsible for ecosystem services estimated at well over $200 billion worldwide—seem to be crashing, while others, like mosquitoes that can carry malaria, dengue and other diseases, seem to be surging. Yet it can be difficult to get an accurate picture how insect populations are shifting.

Many traditional methods of sampling insect populations involve sending entomologists out into the field to collect and identify individual species, and while these methods can yield reliable results, it's also time and resource intensive and often lethal to the insects that get caught. This is where AI comes into the picture.

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With their experience, scientists can tell the difference.  Since many, but not all, insects emit sound, we should be able train AI models to identify them by the unique sounds they make.

In fact, such training is already happening.

Most of the models need huge sets of data to train on, and while they are getting better at working with smaller data sets, they remain data-intensive tools. Furthermore, not all insects emit sounds—such as aphids. And very noisy contexts, like an urban environment, can easily confuse sound-based monitoring efforts.

Automated bioacoustics is a key tool in a multifaceted toolkit that we can use to effectively monitor these important organisms all over the world.

 From buzzes to bytes: A systematic review of automated bioacoustics models used to detect, classify, and monitor insects, Journal of Applied Ecology (2024). DOI: 10.1111/1365-2664.14630. besjournals.onlinelibrary.wile … 1111/1365-2664.14630

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 How 'forever chemicals' affect health

Invisible, omnipresent "forever chemicals" have been linked to a wide range of serious effects on human health, prompting growing calls for them to be banned.

While there is firm evidence that at least one of the more than 4,000 human-made chemicals called PFAS causes cancer, researchers are still attempting to fully understand their broader impact on health.

Here is what we know so far.

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that were first developed in the 1940s to withstand intense heat and repel water and grease. They have since been used in a vast range of household and industrial products including food packaging, make-up, stain-proof fabric, non-stick pots and pans and foam used to fight fires. Because PFAS take an extremely long time to break down—earning them the nickname "forever chemicals"—over the years they have seeped into the soil and groundwater, getting into our food chain and drinking water in the process. These chemicals have now been detected virtually everywhere on Earth, from the top of Mount Everest to inside human blood and brains.

The two most researched PFAS compounds have already been banned or restricted in many countries, though they remain detectable throughout the environment.

Perfluorooctanoic acid (PFOA), which was once used to make the non-stick cookware coating Teflon, was in December classified as "carcinogenic to humans" by the International Agency for Research on Cancer (IARC).

The World Health Organization agency said there is "sufficient evidence" that PFOA gave animals cancer during experiments, as well as "limited evidence" of renal cell and testicular cancer in humans.

Perfluorooctane sulfonic acid  (PFOS)—once the key ingredient in the Scotchgard fabric protector—was meanwhile ruled "possibly carcinogenic to humans".

There was limited proof of cancer in animals but "inadequate evidence regarding cancer in humans", the IARC said.

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More broadly, observational studies have suggested that exposure to PFAS chemicals is associated with an increased rate of cancer, obesity, thyroid, liver and kidney disease, higher cholesterol, low birth weight, infertility and even a lower response to vaccines.

But such observational research cannot prove that the chemicals directly cause these health problems.

And the level of risk can vary greatly depending on the level of PFAS people are exposed to—almost everyone on Earth is believed to have at least a little PFAS in their bodies.

According to the IARC, most at risk for serious PFAS exposure are people who directly work with the chemicals while making products.

Exactly what level of PFAS exposure is hazardous to health has been a matter of debate.

Previously, guidelines in numerous countries ruled that having less than 100 nanogrammes of PFAS per liter of tap water was enough to protect health.

Last year, a media investigation found PFAS levels over 100 nanogrammes per liter at 2,100 sites across Europe and the UK.

The level soared over 10,000 nanogrammes at 300 of the sites, according to the investigation carried out by 16 newsrooms.

Further complicating the ability of research to comprehend the health effects of PFAS is that new compounds are still being developed.

As manufacturers phase out compounds identified as potentially hazardous, they sometimes simply replace it with another member of the PFAS family that has been studied less, researchers have warned.

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Environmentalists and health experts across the world have been increasingly sounding the alarm about forever chemicals.

On Thursday, French MP Nicolas Thierry will introduce a bill that—if passed—would ban non-essential PFAS in France from 2025.

The European Union is also considering a Europe-wide ban on PFAS from as early as 2026.

What can you do?

For people at home, it is nearly impossible to avoid consuming miniscule amounts of PFAS.

But experts recommend reducing contact with non-stick cookware and grease-proof food packaging such as fast food wrappers.

Drinking filtered or bottled water and storing leftovers in glass—not plastic—containers could also help.

Source: AFP and other news agencies

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The omnipresence of PFAS—and what we can do about them

Per- and poly-fluoroalkyl substances (PFAS)—also known as "forever chemicals"—are everywhere. Created in the 1940s, these synthetic compounds are an unseen ingredient in many items that we use in our daily lives, like cleaning products, food packaging, nonstick cookware, cosmetics, personal care items like dental floss, water-repellent clothing, as well as stain-resistant carpets and upholstery. Since the 1970s, they have also been used in firefighting foams and by the military.

Food is another potential source. Unfortunately, PFAS are also present in biosolids which are used as agricultural fertilizer, creating a pathway from contaminated soil to produce in the grocery store.

Because of their longevity and resistance to disintegration—a characteristic born of their carbon-fluorine chemical bonds—PFAS can last thousands of years. These "attributes also make them very resistant to degradation in our treatment systems.

The most common method of destroying PFAS is incineration, but some studies indicate that this fails to eliminate all the chemicals, and instead releases the remaining pollution into the air.

In water treatment systems, the main methods for destroying PFAS are reverse osmosis, activated carbon, and ion-exchange resins—but these technologies are costly. Other methods include supercritical water oxidation, plasma reactors, and most recently, sodium hydroxide (lye) and dimethyl sulfoxide, chemicals used in soap and as a medication for bladder pain syndrome, respectively.

But when items containing PFAS inevitably reach landfills, the compounds leach into the environment. And every day, people flush PFA-laden products—like shampoo, cleaning liquids, even some toilet papers—down the drain.

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If they're not removed in our wastewater treatment plants, [PFAS] get into our rivers, streams, and groundwater, which are commonly used for drinking water production. Around 50% of our rivers and streams contain measurable PFAS concentrations.
According to a 2020 study published in Science by the Environmental Working Group, an estimated 200 million Americans are served by water systems that contain PFAS. And it's not just public systems—a 2023 study by the U.S. Geological Survey found that approximately 20% of private wells are contaminated.

These compounds are now so ubiquitous, that an estimated 98% of the U.S. population has detectable concentrations in their blood. That's concerning, since studies have shown that exposure to some PFAS may be linked to harmful health effects, both in animals and humans.
We know today that even very low concentrations can impact the reproductive system, [have] developmental effects, increase risk of certain cancers, reduce immune response, as well as increase cholesterol levels.
The Environmental Protection Agency also links the compounds to thyroid disorders, obesity, and asthma.
Individuals who may have had high exposure to PFAS—in firefighting or chemical manufacturing industries, for example—should consider blood testing
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we still know very little about the health impacts of PFAS, especially on a population level. While these compounds have been around for some time, there is insufficient research to answer many questions that have emerged over decades.

But some action is being taken. Last year, the EPA proposed the first federal limits on forever chemicals in drinking water. And in February 2024, the agency proposed that nine PFAS be categorized as hazardous to human health—a designation only applied to substances that are toxic or cause cancer, genetic mutation, or embryo malformation.

"The main reason for the step that the EPA is taking is that there's increasing evidence that there are toxic effects on a variety of levels.
The proposal would classify the chemicals as "hazardous constituents" under the Resource Conservation and Recovery Act, making it easier for the agency to clean up contaminated sites—and to allocate funds to treat affected drinking water.

But these nine compounds are only the tip of the iceberg.

"Researchers estimated there are more than 12,000 individual PFAS compounds, and unfortunately for most of them, we have basically no understanding about toxicity, and we don't really know a lot about their occurrence in the environment.
A small study published in Environment International showed that cholestyramine—a cholesterol-lowering drug—could help scrub toxic forever chemicals from the blood of people who have been highly exposed. But the most efficient way to reduce contamination is preventatively.
by regulating PFAS production and cleaning up the environment—especially waterways—and ensuring that our drinking water facilities are equipped to remove these compounds.

"The issue at this point is really that we don't know what levels are concerning or lead to health effects, and which don't.
That's something that only the future will tell."
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experts recommend a variety of actions to minimize exposure to PFAS:

Avoid using nonstick cookware.
Limit use of food packaging, such as grease-resistant takeout containers.
Filter your water at the tap, with pitchers that are certified for PFAS.
Avoid wearing water-resistant textiles.
Seek out PFAS-free retailers' products—including menstrual products and large items like carpets or furniture.

Janne Julie Møller et al, Substantial decrease of PFAS with anion exchange resin treatment – A clinical cross-over trial, Environment International (2024). DOI: 10.1016/j.envint.2024.108497

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Ancient Egyptian Mummies Are Riddled With Malaria, Worms, And Lice

The inhabitants of ancient Egypt were infested with parasites, many of which caused anemia and other debilitating conditions. According to a new meta-analysis of prior research on Egyptian mummies, around two-thirds suffered from worms of various kinds, while 22 percent had malaria and 40 percent had headlice.

In the famous Valley of the Kings, for instance, four out of 16 mummies tested for Plasmodium falciparum – the microbe responsible for a deadly form of malaria – were positive. One of these was Tutankhamun, who was found to be infected by two different strains though probably died from falling from his chariot rather than as a result of malaria.

According to study author Piers D. Mitchell from the University of Cambridge, 49 of the 221 Egyptian mummies analyzed for malaria tested positive.  “As such, we would expect malaria to have had a major impact upon child deaths and debilitating anemia in all ancient populations along the Nile.”

Indeed, 92 percent of malaria-infected mummies display porous bones and other signs of anemia, which is characterized by a reduced number of red blood cells or depleted hemoglobin levels. “Such a disease burden must have had major consequences upon the physical stamina and productivity of a large proportion of the workforce,” writes Mitchell.

Other parasites detected in ancient Egyptian mummies include the mind-altering pathogen toxoplasmosis, which has been linked to schizophrenia and, bizarrely, an increased likelihood of dying in a car crash. “As toxoplasmosis can be caught by humans when they are in close contact with cats, it is possible that the disease occurred due to the role of cats as cult animals which were often mummified and used as religious offerings in ancient Egypt,” explains the author.

Mitchell also estimates that around 10 percent of mummies are positive for visceral leishmaniasis, which has also been linked to anemia and is fatal in around 95 percent of untreated cases. Stomach worms such as fish tapeworm have also been detected in two mummies and were probably caught by eating undercooked fish from the Nile.

Another type of worm known as trichinosis was identified in the chest muscles of the mummy of an individual called Nakht, who has been identified as a weaver from the royal funerary chapel at Thebes. Typically contracted by eating undercooked pork, this nasty little nematode encysts inside muscle tissue and can cause death if it enters the heart.

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Nakht was also found to be riddled with worms that infect both the blood vessels and the urinary tract. Like 65 percent of other mummies, he suffered from schistosomiasis, an acute parasitic illness caused by worms known as blood flukes.

Another mummy housed at the Manchester Museum even had worms in its brain, while 40 percent of 218 mummies analyzed for headlice turned out to be positive.
Explaining this high prevalence of microscopic nasties, Mitchell suspects that “the River Nile acted as a conduit for tropical water-born parasites that would not normally be found in arid regions.” Malaria-carrying mosquitoes and other harmful pathogens could therefore have flourished in ancient Egypt despite low levels of rainfall.

However, as well as bringing death, the Nile may also have helped to fertilize agricultural fields by depositing sediment during annual floods. As a result, farmers didn’t have to fertilize their crops with human poop, which may explain why ancient Egyptian mummies show very low rates of whipworm and roundworm, both of which were common throughout the Middle East and Mediterranean.

https://www.sciencedirect.com/science/article/abs/pii/S0065308X2300...

mRNA shows promise beyond vaccines
A therapy that extends mRNA technology beyond vaccines has shown early success in treating a rare genetic disease, propionic acidaemia, that prevents people from processing certain nutrients. The treatment — made by US pharma company Moderna, and known as mRNA-3927 — gives those treated a working copy of the instructions needed to make an enzyme that is missing in people with the disease. In a small clinical trial, half of the participants receiving the therapy saw their risk of life-threatening episodes decrease by 70-80%. But the drug also produced side effects and required frequent infusions.

https://www.nature.com/articles/d41586-024-00954-4?utm_source=Live+...

Four in five bird species cannot tolerate intense human pressures, data show

Currently 14% of the world's 11,000 bird species are threatened with extinction. A new study assessed the populations of bird species across a spectrum of landscapes from pristine habitats to human-dominated environments.

Threatened species, and species with declining populations, are less tolerant to breeding in human-dominated habitats. For example, the Fern Wren, a species occurring only in tropical forests of northeastern Australia, is endangered, has a declining population and a very low tolerance to any human pressure, say the researchers. However, not all species are as sensitive to living alongside humans. Some species can tolerate even the most intense human pressures on all continents. Common Swifts are an example of such species that can be found breeding in urban areas all around the world.
Following the UN's Kunming–Montreal Global Biodiversity Framework, goals have been set to protect 30% of the Earth's land for conservation, but not much of that percentage will be pristine habitat.
This new study enables us to identify species that are particularly sensitive to human activity and need more protected habitats to thrive, for example the Great Snipe in Europe, the Nkulengu Rail in Africa and the Hume's Lark in Asia. Conservation action to protect or restore habitat can then be targeted towards the species and locations that need it most.
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Europe and North America had higher proportions of human-tolerant bird species than Latin America and Africa did. Europe has a long history of environmental impacts spanning millennia, which, according to the researchers, may have resulted in historical disappearances of sensitive species and also in a long time frame for the remaining species to adapt to the gradually changing landscapes.

The researchers quantified tolerance to breeding in human-dominated environments for 6,000 bird species. The data on birds originated from citizen science observations from the eBird project from 2013–2021. The data on the extent of human impact was the Human Footprint Index that summarizes the combined pressures of built environments, human population density, night-time lights, agriculture and roads.

Emma‐Liina Marjakangas et al, Bird species' tolerance to human pressures and associations with population change, Global Ecology and Biogeography (2024). DOI: 10.1111/geb.13816

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Bird flu has infected a person after spreading to cows

A strain of avian influenza that has likely sickened and killed millions of birds around the globe has popped up in an unexpected species: Cows.

On April 1, the U.S. Department of Agriculture confirmed that cattle on a farm in New Mexico had tested positive for a strain of bird flu called H5N1. The news followed a March 25 announcement that officials had detected the virus on two dairy farms in Kansas and two Texas farms. The virus was also detected in a Michigan herd that had recently received cows from Texas, the USDA reported on March 29. Five additional herds in Texas have tested positive, and an outbreak in Idaho is presumed to have been caused by H5N1.

A person exposed to cattle on one of those Texas farms has tested positive too, becoming only the second person in the United States ever documented to be infected with H5N1, the U.S. Centers for Disease Control and Prevention reported April 1. The individual is being treated with an antiviral drug for a single symptom, eye redness. It’s unclear how the cows were infected, although consuming wild bird excrement is a possibility. The person was probably infected while in close contact with the cows. Most people fall ill with H5N1 only after close contact with infected animals, typically poultry, and these infections can be mild to deadly. Right now, the CDC considers H5N1’s risk to people to be low. But milk from infected cows should be thrown out before reaching our food supply, the USDA says. Pasteurization would also kill the virus, so it should not spread through the country’s milk, the agency said.

https://www.cdc.gov/media/releases/2024/p0401-avian-flu.html

A new study has linked microplastics to heart attacks and strokes. Here’s what we know 

The results have renewed concerns about plastics’ potential effects on human health

Tiny flecks of plastic inside in the arteries may ramp up the risks of cardiovascular disease.

An analysis of artery-clogging plaques in 257 patients found that the presence of these microplastics was associated with a roughly quadr..., researchers report March 7 in the New England Journal of Medicine. 

The extent of that enhanced risk is “stunning,” say the researchers. Because  “very, very, very few things have that much of a risk.”

The study has gained attention worldwide and renewed concerns about the effects of plastics on human health. It’s also one of a growing number of reports that have found microscopic particles of plastic inside our bodies’ tissues, including the lungs, liver and blood.

Plastic is everywhere and enters our body through multiple routes 

When plastic toys, pipes, food containers and other objects inevitably break down over time, they can shed infinitesimal particles into our environment. Scientists have already documented how broadly these plastic smithereens have scattered.

Particles speckle even extreme locations, from the depths of the ocean to nearly the peak of Mount Everest.  Microplastics, which are smaller than 5 millimeters (about the size of a peppercorn) and nanoplastics, which are roughly one five-thousandth that size, can get into our water, accumulate in soil and waft along whispers of wind.

These specks of plastic pollution can travel into our bodies via food and drink, the air we breathe and even directly through the skin. And our exposure to microplastics will only go up, say experts.

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Scientists examined plaque samples from patients who had undergone surgery to clean out their carotid arteries, blood vessels in the neck that carry blood to the brain. They found that more than half of patients had evidence of at least one type of plastic.

These patients’ plaques all contained polyethylene, a ubiquitous material used in everything from cling wrap to cutting boards. And in 12 percent of the patients, scientists also found polyvinyl chloride, or PVC. 

Of 150 people with evidence of these plastics, 30 died or experienced a nonfatal stroke or heart attack within roughly the next three years. That’s compared to eight out of 107 people whose plaques appeared to be plastic-free, the team reports.

It’s too early to say whether microplastics in the arteries can cause heart attacks

It’s possible that plastics inside the arteries drive inflammation, further kindling cardiovascular disease. Plaques embedded with plastic, for instance, tended to contain more inflammatory molecules than plastic-free plaques, the research  team found.

The researchers did not prove that microplastics are harmful, scientists say. They simply exposed a link between plastics in plaques and poor outcomes in patients.

The plaque study offers yet another reason why it’s probably a good idea to reduce plastic use 

R. Marfella et al. Microplastics and nanoplastics in atheromas and cardiovascular events. The New England Journal of Medicine. Published online March 7, 2024. doi: 10.1056/NEJMoa2309822.

M. A. Garcia et al. Quantitation and identification of microplastics accumulation in hu... Toxicological Sciences. Published online February 17, 2024. doi:10.1093/toxsci/kfae021.

Part 2

Huge star explosion to appear in sky in once-in-a-lifetime event

Sometime between now and September, a massive explosion 3,000 light years from Earth will flare up in the night sky, giving amateur astronomers a once-in-a-lifetime chance to witness this space oddity.

The binary star system in the constellation Corona Borealis—"northern crown"—is normally too dim to see with the naked eye.

But every 80 years or so, exchanges between its two stars, which are locked in a deadly embrace, spark a runaway nuclear explosion.

The light from the blast travels through the cosmos and makes it appear as if a new star—as bright as the North Star, according to NASA—has suddenly just popped up in our night sky for a few days.

It will be at least the third time that humans have witnessed this event, which was first discovered by Irish polymath John Birmingham in 1866, then reappeared in 1946.

There are only around 10 recurring novas in the Milky Way and surrounding galaxies. Normal novas explode "maybe every 100,000 years". But recurrent novas repeat their outbursts on a human timeline because of a peculiar relationship between their two stars.

The other is a white dwarf, a later stage in the death of a star, after all the atmosphere has blown away and only the incredibly dense core remains.

Their size disparity is so huge that it takes T Coronae Borealis's white dwarf 227 days to orbit its red giant. 

The two are so close that matter being ejected by the red giant collects near the surface of the white dwarf.

Once the mass roughly of Earth has built up on the white dwarf—which takes around 80 years—it heats up enough to kickstart a runaway thermonuclear reaction. This ends up in a "big explosion and within a few seconds the temperature goes up 100-200 million degrees Celsius". 

But you do not need  advanced technology to witness this rare event—whenever it may happen. You simply have to go out and look in the direction of the Corona Borealis .... and you can see it with your own naked eyes!

This particular star explosion is unique for its brief yet intense display, completing its cycle in merely a week. 

Source: AFP and other news agencies

Differences between nova and supernova explosions

The cosmos is a stage for some of the most spectacular and powerful events known to science. Among these, nova and supernova explosions stand out for their brilliance and the fundamental roles they play in the universe’s lifecycle.

Despite the similarity in their names, novae and supernovae differ vastly in their origins, mechanisms, and consequences. This article demystifies these cosmic phenomena, highlighting their distinct characteristics.

What is a nova?

As discussed above, a nova occurs in a binary star system, where a white dwarf and a companion star orbit closely. The white dwarf, a dense remnant of a star that has exhausted its nuclear fuel, pulls material — primarily hydrogen — from its companion.

This material accumulates on the white dwarf’s surface, eventually igniting in a thermonuclear explosion. The explosion causes the white dwarf to brighten significantly, but it does not result in the star’s destruction. Instead, the process may repeat if the white dwarf continues to accrete material.

What is a supernova?

In contrast, a supernova is a cataclysmic event marking the death of a star. Supernovae can occur in one of two primary ways:

Core-Collapse Supernova: This type happens at the end of a massive star’s life cycle. When the star’s core runs out of nuclear fuel, it can no longer support the outer layers against gravity. The core collapses, resulting in a massive explosion that obliterates the star.

Type Ia Supernova: This type involves a binary system where a white dwarf accretes material from a companion star, similar to a nova. However, in this case, the white dwarf reaches a critical mass (Chandrasekhar limit), leading to a runaway nuclear reaction that completely destroys the white dwarf.

Key differences between novae and supernovae

Scale and Energy

The most striking difference lies in their scale and the energy released. Supernovae are among the universe’s most energetic events, outshining entire galaxies and releasing vast amounts of energy. Novae, while still bright and powerful, are far less energetic and only cause a temporary increase in brightness.

Frequency and Visibility

Supernovae are relatively rare events, occurring about once every 50 years in a galaxy the size of the Milky Way. Novae, on the other hand, are more common, with several occurring in our galaxy each year. Despite their rarity, supernovae can often be seen from greater distances due to their immense brightness.

Enigmatic white dwarfs

Central to the spectacle of T Coronae Borealis is the white dwarf, a stellar remnant that offers profound insights into the life cycles of stars.

White dwarfs are the end products of stars that originally had masses up to eight times that of the Sun but ended their lives in a relatively peaceful manner, without exploding as supernovae.

These stellar cores are fascinating for several reasons:

• Density and Composition: Despite their diminutive size, white dwarfs are incredibly dense. Their mass is comparable to that of the Sun, but they have a volume similar to Earth’s. This high density arises because the matter within them is in a degenerate state, where electrons are packed closely together.
• Cooling Process: After their formation, white dwarfs embark on a long cooling process. They start out extremely hot but gradually radiate away their heat over billions of years, eventually fading into black dwarfs — theoretical objects that have not yet been observed because the universe is not old enough.
• Limiting Mass: The Chandrasekhar limit, approximately 1.4 times the mass of the Sun, defines the maximum mass a white dwarf can have. Beyond this limit, the star would collapse under its own gravity to form a neutron star or a black hole.

Window into cosmic evolution

In summary, the study of T Coronae Borealis and white dwarfs opens a window into the complex processes governing stellar evolution.

Part3

Scientists discover speed of visual perception ranges widely in humans

Using a blink-and-you'll-miss-it experiment, researchers from Trinity College Dublin have discovered that individuals differ widely in the rate at which they perceive visual signals. Some people perceive a rapidly changing visual cue at frequencies that others cannot, which means some access more visual information per timeframe than others.

This discovery suggests some people have an innate advantage in certain settings where response time is crucial, such as in ball sports, or in competitive gaming.

The rate with which we perceive the world is known as our "temporal resolution," and in many ways it is similar to the refresh rate of a computer monitor.

The researchers found that there is considerable variation among people in their temporal resolution, meaning some people effectively see more "images per second" than others.

To quantify this, the scientists used the "critical flicker fusion threshold," a measure for the maximum frequency at which an individual can perceive a flickering light source.

If the light source flickers above a person's threshold, they will not be able to see that it is flickering, and instead see the light as steady. Some participants in the experiment indicated they saw the light as completely still when it was in fact flashing about 35 times per second, while others were still able to perceive the flashing at rates of over 60 times per second.

The researchers  also measured temporal resolution on multiple occasions in the same participants and found that even though there is significant variation among individuals, the trait appears to be quite stable over time 'within' individuals.

Part 1

Though our visual temporal resolution is quite stable from day to day in general, a post-hoc analysis did suggest that there may be slightly more variation over time within females than within males.

We don't yet know how this variation in visual temporal resolution might affect our day-to-day lives, but scientists think that individual differences in perception speed might become apparent in high-speed situations where one might need to locate or track fast-moving objects, such as in ball sports, or in situations where visual scenes change rapidly, such as in competitive gaming, or escaping a speeding vehicle.
This suggests that some people may have an advantage over others before they have even picked up a racquet and hit a tennis ball, or grabbed a controller and jumped into some fantasy world online.
What is really interesting about this project is how a zoologist, a geneticist and a psychologist can all find different angles to this work. For me as a zoologist the consequences of variation in visual perception likely has profound implications for how predators and prey interact, with various arms-races existing for investment in brain processing power and clever strategies to exploit weaknesses in one's enemy.
Because we only have access to our own subjective experience, we might naively expect that everyone else perceives the world in the same way we do. Examples like color blindness show that isn't always true, but there are many less well known ways that perception can vary too.

"This study characterizes one such difference—in the 'frame rate' of our visual systems. Some people really do seem to see the world faster than others."

Now if I can read 80 research papers per day, and can write 50 reviews and articles per day, or can answer 10 tough questions per day, remember, there is nothing wrong with you. 

Our worlds are just different from each other! :)

PLoS ONE (2024). DOI: 10.1371/journal.pone.0298007

Exploring how oxytocin interacts with testosterone while humans play a game modeling intergroup conflict

Over the past decades, numerous studies have investigated the neural and cognitive processes underpinning intergroup conflict, as this could help to explain what fuels belligerent behavior, political clashes, and wars. While these works gathered some interesting findings, much about these processes remains poorly understood until now.

Researchers  recently carried out a study specifically exploring how the hormones oxytocin and testosterone modulate people's behavior during an experimental game modeling intergroup conflict.

Their findings, published in Communications Psychology, suggest that oxytocin interacts with men's testosterone reactivity to modulate parochial altruism (i.e., behavior that benefits the group one belongs to, while negatively impacting competing groups).

Individuals regularly carry out actions which are costly to themselves, but advance the interests of their own group, often even at the expense of rival groups.

We see examples of such behavior all the time, including sports rivalries (playing injured), political partisanship (voting along party lines), and in extreme cases ethnic, religious, or national conflicts.

"Evolutionary theories, going back to Darwin, suggest that such acts of parochial altruism—the favoring of one's ingroup—emerged during human ancestry because they provided an advantage for group survival."

The researchers set out to study how individuals make decisions in a controlled laboratory setting modeling intergroup conflict, as this could shed light on the dynamics driving behaviors commonly observed outside laboratory settings.

Past social psychology research consistently found that people's social regard (i.e., their willingness to trust others, empathize with them and behave altruistically) is greatly influenced by their belonging to specific groups. Nonetheless, the biological underpinnings of these group-driven behaviors are yet to be clearly elucidated.

Part 1

Previous research,  suggested independent roles of oxytocin and testosterone—hormones that are associated with intergroup relations and cooperation-aggression—in shaping behaviour during intergroup conflict.

How the two hormones interact, had yet to be tested. These hormones exert contrasting effects on various social behaviors, leading us to hypothesize that their combined influence might hold the key to understanding intergroup dynamics. This study filled that gap.

The primary objective of the recent work  by researchers was to better understand how the interaction between oxytocin and testosterone influences behavior in the context of intergroup conflict. While many past studies focusing on this topic only included male participants, the researchers decided to also include female participants, as this would allow them to discover any sex differences that may exist.
To model intergroup conflict in an experimental setting, the researchers used an adaptation of the game commonly referred to as "chicken." This game has often been portrayed in popular media, including in the movies "Rebel without a Cause," "Footloose" and "Grease," and is also used in political science to describe elements of conflict between nations, such as the nuclear brinkmanship of the Cuban Missile crisis.
Part 2

The classic version of the game of 'chicken' pits two drivers against each other on a collision course.

To carry out their experiments, Israel, Cherki and their colleagues used a laboratory-based adaptation of the chicken game, known as the "intergroup chicken game." This version of the game has the same underlying rules, but with players divided into groups that are pitted against each other.

The researchers' experiment was double-blind and included a placebo condition. They recruited 204 participants and divided them into groups of eight or 12, each of which contained an equal number of males and females.

These groups of participants completed 30 rounds of the intergroup chicken game and at the beginning of each experimental session, participants were asked to self-administer either a placebo gas or oxytocin. Notably, neither the participants nor the experimenters were aware of what was being inhaled, which eliminated biases and prevented prior knowledge of what was administered during each trial from impacting the results.

One of the most notable observations of this study was that the interaction between oxytocin and testosterone greatly influenced the behavior of male participants. Contrarily, the interplay between these two hormones did not appear to impact the behavior of female participants.

Researchers observed that under placebo conditions, elevations in testosterone levels corresponded to heightened aggression towards outgroups. However, the administration of internasal oxytocin cancelled out this association, suggesting a regulatory role for oxytocin in moderating testosterone-induced aggression within intergroup dynamics.

Overall, the recent findings gathered by this team of researchers suggest that there could be notable sex differences in the dynamics underlying parochial altruism in intergroup conflict. In fact, they showed no substantial link between testosterone reactivity and outgroup aggression in females.

This underscores the importance of considering sex-specific effects when examining the neurobiological underpinnings of social behaviour.

 Boaz R. Cherki et al, Intranasal oxytocin interacts with testosterone reactivity to modulate parochial altruism, Communications Psychology (2024). DOI: 10.1038/s44271-024-00066-9

Part 3

**

A physicist uses X-rays to rescue old music recordings

Researchers are developing a technique that uses the special synchrotron X-ray light from the Swiss Light Source SLS to non-destructively digitize recordings from high-value historic audio tapes—including treasures from the Montreux Jazz Festival archive, such as a rare recording of the King of the Blues, B.B. King.

Magnetic tapes have almost completely disappeared from our lives and now only enjoy a nostalgic niche existence. However, significant quantities of these analog magnetic media are still stored in the archives of sound studios, radio and TV stations, museums, and private collections worldwide. Digitizing these tapes is an ongoing challenge as well as a race against time, as the tapes degrade and eventually become unplayable. Physicists and experts in nanomagnetism, are developing a method to non-destructively digitize degraded audio tapes in the highest quality using X-ray light. To achieve this goal, they have been collaborating with the Swiss National Sound Archives, which has produced custom-made reference recordings and provided audio engineering know-how. Now, a partnership with the Montreux Jazz Digital Project will help to further develop and test the method.
The remaining members of the famous rock band Queen recently faced a big challenge. In their studio, the musicians found a tape from 1988 containing a song with the voice of their legendary singer Freddie Mercury, who died in 1991. However, the tape was badly damaged. At first, no one believed they would be able to save this special piece. With great effort, the sound engineers managed to succeed after all.
Part 1

While it is possible to painstakingly reassemble and restore such tapes, these researchers are pursuing a completely new approach. They use synchrotron radiation : With X-ray light from a synchrotron, they can reconstruct even heavily damaged tape fragments without even touching them.

Audio tapes store information in a layer of tiny magnetic particles—like little compass needles pointing either north or south. When the tape is recorded, their magnetic orientation is changed—the tape becomes magnetized, and the audio information is now physically stored in the orientation pattern. To play back this pattern, the tape is moved past a play head. As the magnetic field constantly changes through the pattern, a voltage is induced in the play head and an electrical signal is generated. This signal is amplified and converted into an acoustic signal.

With his new X-ray method, researchers do not rely on the magnetic field, but on the individual compass needles that generate this field. The magnetization states of these tiny particles, whose size is smaller than a tenth of the diameter of a human hair, can be read out almost individually using the X-ray light of the SLS and converted into a high-quality audio signal.

Since the synchrotron light can measure almost every single magnetic compass needle on the tape, it can achieve unprecedented resolution.

https://www.psi.ch/en/media/our-research/rescuing-music-with-x-rays

Part 2

Write it down, then throw it away: Research confirms a simple method for reducing anger

A research group  has discovered that writing down one's reaction to a negative incident on a piece of paper and then shredding it or throwing it away reduces feelings of anger.

This research is important because controlling anger at home and in the workplace can reduce negative consequences in our jobs and personal lives. Unfortunately, many anger management techniques proposed by specialists lack empirical research support. They can also be difficult to recall when angry.

The results of this study, published in Scientific Reports, are the culmination of years of previous research on the association between the written word and anger reduction. It builds on work showing how interactions with physical objects can control a person's mood.

Yuta Kanaya et al, Anger is eliminated with the disposal of a paper written because of provocation, Scientific Reports (2024). DOI: 10.1038/s41598-024-57916-z , doi.org/10.1038/s41598-024-57916-z

First ever measurement of qubits with ultrasensitive thermal detectors, evading Heisenberg uncertainty principle

Chasing ever-higher qubit counts in near-term quantum computers constantly demands new feats of engineering.

Among the troublesome hurdles of this scaling-up race is refining how qubits are measured. Devices called parametric amplifiers are traditionally used to do these measurements. But as the name suggests, the device amplifies weak signals picked up from the qubits to conduct the readout, which causes unwanted noise and can lead to decoherence of the qubits if not protected by additional large components. More importantly, the bulky size of the amplification chain becomes technically challenging to work around as qubit counts increase in size-limited refrigerators. Researchers have now demonstrated in a Nature Electronics paper that bolometer measurements can be accurate enough for single-shot qubit readout.
To the chagrin of many physicists, the Heisenberg uncertainty principle determines that one cannot simultaneously know a signal's position and momentum, or voltage and current, with accuracy. So it goes with qubit measurements conducted with parametric voltage-current amplifiers.

But bolometric energy sensing is a fundamentally different kind of measurement—serving as a means of evading Heisenberg's infamous rule. Since a bolometer measures power, or photon number, it is not bound to add quantum noise stemming from the Heisenberg uncertainty principle in the way that parametric amplifiers are.
Part1

Unlike amplifiers, bolometers very subtly sense microwave photons emitted from the qubit via a minimally invasive detection interface. This form factor is roughly 100 times smaller than its amplifier counterpart, making it extremely attractive as a measurement device.
In their very first experiments, they found these bolometers accurate enough for single-shot readout, free of added quantum noise, and they consume 10,000 times less power than the typical amplifiers—all in a tiny bolometer, the temperature-sensitive part of which can fit inside of a single bacterium.
Single-shot fidelity is an important metric physicists use to determine how accurately a device can detect a qubit's state in just one measurement as opposed to an average of multiple measurements. In the case of the QCD group's experiments, they were able to obtain a single-shot fidelity of 61.8% with a readout duration of roughly 14 microseconds. When correcting for the qubit's energy relaxation time, the fidelity jumps up to 92.7%.

With minor modifications, they could expect to see bolometers approaching the desired 99.9% single-shot fidelity in 200 nanoseconds. For example, they can swap the bolometer material from metal to graphene, which has a lower heat capacity and can detect very small changes in its energy quickly. And by removing other unnecessary components between the bolometer and the chip itself, they can not only make even greater improvements on the readout fidelity, but they can achieve a smaller and simpler measurement device that makes scaling-up to higher qubit counts more feasible.

András M. Gunyhó, Single-Shot Readout of a Superconducting Qubit Using a Thermal Detector, Nature Electronics (2024). DOI: 10.1038/s41928-024-01147-7

Physicists discover a novel quantum state in an elemental solid

Physicists have observed a novel quantum effect termed "hybrid topology" in a crystalline material. This finding opens up a new range of possibilities for the development of efficient materials and technologies for next-generation quantum science and engineering.

The finding, published in Nature, came when  scientists discovered that an elemental solid crystal made of arsenic (As) atoms hosts a never-before-observed form of topological quantum behaviour. They were able to explore and image this novel quantum state using a scanning tunneling microscope (STM) and photoemission spectroscopy, the latter a technique used to determine the relative energy of electrons in molecules and atoms.

This state combines, or "hybridizes," two forms of topological quantum behavior—edge states and surface states, which are two types of quantum two-dimensional electron systems. These have been observed in previous experiments, but never simultaneously in the same material where they mix to form a new state of matter.

M. Zahid Hasan, A hybrid topological quantum state in an elemental solid, Nature (2024). DOI: 10.1038/s41586-024-07203-8. www.nature.com/articles/s41586-024-07203-8

AI makes retinal imaging 100 times faster, compared to manual method

Researchers  have applied artificial intelligence (AI) to a technique that produces high-resolution images of cells in the eye. They report that with AI, imaging is 100 times faster and improves image contrast 3.5-fold. The advance, they say, will provide researchers with a better tool to evaluate age-related macular degeneration (AMD) and other retinal diseases.

 Vineeta Das, Furu Zhang, Andrew Bower, et al. Revealing speckle obscured living human retinal cells with artificial intelligence assisted adaptive optics optical coherence tomography, Communications Medicine (2024). DOI: 10.1038/s43856-024-00483-1

Witness the awe-inspiring spectacle of explosive solar phenomena during the April 8 total eclipse! Expert analysis delves into solar flares, coronal mass ejections, and mesmerizing sunspots

Scientists discover first nitrogen-fixing organelle

Biology textbooks have to be re-written now. Because  they assert that only bacteria can take nitrogen from the atmosphere and convert it into a form that is usable for life. Plants that fix nitrogen, such as legumes, do so by harbouring symbiotic bacteria in root nodules. But a recent discovery upends that rule.

In two recent papers, an international team of scientists describes the first known nitrogen-fixing organelle within a eukaryotic cell. The organelle is the fourth example in history of primary endosymbiosis—the process by which a prokaryotic cell is engulfed by a eukaryotic cell and evolves beyond symbiosis into an organelle.

It's very rare that organelles arise from these types of things. 

The first time we think it happened, it gave rise to all complex life. Everything more complicated than a bacterial cell owes its existence to that event leading  to the origins of the mitochondria. A billion years ago or so, it happened again with the chloroplast, and that gave us plants.

The third known instance involves a microbe similar to a chloroplast.

The newest discovery is the first example of a nitrogen-fixing organelle, which the researchers are calling a "nitroplast".
Part 1

In a paper published in Cell in March 2024,  researchers show that the size ratio between UCYN-A (a short DNA sequence of what appeared to be from an unknown nitrogen-fixing cyanobacterium in Pacific Ocean seawater) and their algal hosts is similar across different species of the marine haptophyte algae Braarudosphaera bigelowii.

The researchers use a model to demonstrate that the growth of the host cell and UCYN-A are controlled by the exchange of nutrients. Their metabolisms are linked. This synchronization in growth rates led the researchers to call UCYN-A "organelle-like."

That's exactly what happens with organelles. If you look at the mitochondria and the chloroplast, it's the same thing: they scale with the cell.

But the scientists did not confidently call UCYN-A an organelle until confirming other lines of evidence. In the cover article of the journal Science, published recently, researchers show that UCYN-A imports proteins from its host cells.

That's one of the hallmarks of something moving from an endosymbiont to an organelle. They start throwing away pieces of DNA, and their genomes get smaller and smaller, and they start depending on the mother cell for those gene products—or the protein itself—to be transported into the cell.

These independent lines of evidence leave little doubt that UCYN-A has surpassed the role of a symbiont. And while mitochondria and chloroplasts evolved billions of years ago, the nitroplast appears to have evolved about 100 million years ago, providing scientists with a new, more recent perspective on organellogenesis.

The organelle also provides insight into ocean ecosystems. All organisms need nitrogen in a biologically usable form, and UCYN-A is globally important for its ability to fix nitrogen from the atmosphere. Researchers have found it everywhere from the tropics to the Arctic Ocean, and it fixes a significant amount of nitrogen.

 Tyler H. Coale et al, Nitrogen-fixing organelle in a marine alga, Science (2024). DOI: 10.1126/science.adk1075

Francisco M. Cornejo-Castillo et al, Metabolic trade-offs constrain the cell size ratio in a nitrogen-fixing symbiosis, Cell (2024). DOI: 10.1016/j.cell.2024.02.016

Part 2

Plant more native trees to reduce landslide risk, control erosion, say researchers

Landslides typically occur under heavy rain. With the potential for increased precipitation due to climate change and a possible return to La Niña reinforcing slopes with native trees and shrubs could be an effective, economical and sustainable solution.

Homeowners, councils and state governments looking to build houses and infrastructure on or near slopes should reconsider cutting down trees or using artificial slope reinforcement to buttress vertical terrain against landslides and slips.

They should plant native trees and shrubs instead, according to scientists. Plants provide a sustainable, natural approach to slope reinforcement, compared to artificial methods, such as steel mesh or sprayed concrete. They also create and maintain crucial habitat.

Jiale Zhu et al, An experimental study on root-reinforced soil strength via a steel root analogue in unsaturated silty soil, Acta Geotechnica (2023). DOI: 10.1007/s11440-023-01918-0

Don't depend on old Biology text books and theories for knowledge. Why Biology, all science is changing rapidly and progressing with rocket speed.

Each day I read a large amount of stories that are rewriting the old science textbooks. If you don't get updated, you remain a creature living under the big rock - very ancient, half-blind, half-mute and half-minded!

Science is not wine. It doesn't get better as it ages, it gets stale instead.

Science is like a running river, if you don't move as speedily as it does, you rot like an old log and decay!

(This ‘s my reply to a person who complained that my reports are contradicting Biology text books!)

Tiny AI-trained robots demonstrate soccer skills

How the inflamed brain becomes disconnected after a stroke

Whether reeling from a sudden stroke or buckling under the sustained assault of Alzheimer's, the brain becomes inflamed, leading to cognitive problems and even death.

Scientists have known for many years that severe inflammation can kill the brain's neurons. Now, researchers  have discovered that even subtle inflammation damages the brain.

Instead of killing neurons outright, however, relatively mild inflammation only destroys the arm-like projections, called neurites, that wire neurons together. These connections are vital for everything the brain does, including learning and memory.

The findings, published last month in Cell Reports, describe in detail a new degenerative pathway that scientists can now try to disrupt. This could help stem the damage from common neurological diseases.

There are several exciting drugs now entering clinical use that interrupt these inflammatory processes, and now we know to look at their effects on neurites.

Not too far off, this could have a big impact on helping patients.

Inflammation is the body's first line of defense when something goes wrong. It rushes blood to an injured area, bathing it with immune cells that release chemicals to kill pathogens.

Scientists wanted to know how this inflammatory process was damaging the brain. They Researchers were particularly interested in molecular aggregates, called cofilactin rods (CARs), that appear after a stroke. CARs form when two proteins, called cofilin and actin, that normally maintain neurites, break loose, forming messy clumps.

CARs are known to form in response to a chemical called superoxide, which immune cells release when the brain is inflamed.

To get a closer look at this process, the researchers stimulated inflammation in a part of the mouse brain that controls movement. They expected that neurons would die and the mice would have trouble moving.

The mice did struggle to move, but when the researchers looked at their brain tissue under a microscope, they were surprised to see that only the neurites had withered away, leaving the neurons isolated like stars in the night sky. The loss of these connections was enough to rob the mice of some of their motor coordination.

The scientists then tried reducing the amount of either superoxide or cofilin, and treated the brain with the same inflammatory substance. Under these conditions, fewer CARs formed, and the neurites survived. The mice also retained their coordination.

They had discovered a new pathway: inflammation caused immune cells to release superoxide, pulling cofilin and actin out of neurites and making CARs. Neurites died, and the disconnected brain malfunctioned.

Many neurological diseases involve inflammation, including multiple sclerosis, traumatic brain injury, and amyotrophic lateral sclerosis (ALS).

Now that scientists understand it better, they can design therapies to interrupt this inflammatory pathway. Stroke patients, for example, could be treated early on with anti-inflammatory agents to shield neurites from damage and preserve cognition.

Gökhan Uruk et al, Cofilactin rod formation mediates inflammation-induced neurite degeneration, Cell Reports (2024). DOI: 10.1016/j.celrep.2024.113914

Part 2