Plastic Was Found Inside More Than 50% of Plaques From Clogged Arteries

With microplastics previously found coursing through people's bloodstream, the researchers were reasonably concerned about heart health. Lab-based studies suggest microplastics can trigger inflammation and oxidative stress in heart cells, and impair heart function, alter heart rate, and cause scarring of the heart in animals such as mice.

"Observational data from occupational-exposure studies [also] suggest an increased risk of cardiovascular disease among persons who are exposed to plastics-related pollution, including polyvinyl chloride, than that seen in the general population," Marfella and colleagues write.
In the study, patients with microplastics in their excised plaques were 4.5 times as likely to have experienced a stroke, non-fatal heart attack or died from any cause after 34 months than people who had no detectable microplastics in the plaques that surgeons had removed.

The amount of microplastics, and even smaller particles called nanoplastics, was measured using a technique called pyrolysis–gas chromatography–mass spectrometry, and their presence confirmed using another method, stable isotopes analysis, which can distinguish between the carbon of human tissues and that of plastics made from petrochemicals.

Microplastics were also visible under powerful microscopes: The researchers observed plastic fragments with jagged edges inside immune cells called macrophages, and within the fatty plaques. Examining the tissue samples, the team also found higher levels of inflammatory markers in patients with microplastics in their plaques.
Part 2

Bear in mind, however, that an observational study like this can't definitively conclude that microplastics are causing the downstream heart effects; only that there is an association. The study did not consider other risk factors for cardiovascular disease, such as smoking, physical inactivity, and air pollution.
"Although we do not know what other exposures may have contributed to the adverse outcomes among patients in this study, the finding of microplastics and nanoplastics in plaque tissue is itself a breakthrough discovery that raises a series of urgent questions," such as how to reduce exposure, explained pediatrician, public health physician and epidemiologist Philip J. Landrigan, of Boston College, in an accompanying editorial.

Plastic production has exploded in the past two decades, only a fraction of which has been recycled, and yet rates of cardiovascular disease have been falling in some parts of the world, so more research is needed to understand the link between the two.

https://www.nejm.org/doi/10.1056/NEJMoa2309822

Part 3

**

Study debunks link between moderate drinking and longer life

Probably everyone has heard the conventional wisdom that a glass of wine a day is good for you—or you've heard some variation of it. The problem is that it's based on flawed scientific research, according to a new report in the Journal of Studies on Alcohol and Drugs.

Over the years, many studies have suggested that moderate drinkers enjoy longer lives with lower risks of heart disease and other chronic ills than abstainers do. That spurred the widespread belief that alcohol, in moderation, can be a health tonic. However, not all studies have painted such a rosy picture—and the new analysis sheds light on why.

In a nutshell, studies linking moderate drinking to health benefits suffer from fundamental design flaws, said lead researcher Tim Stockwell, Ph.D., a scientist with the Canadian Institute for Substance Use Research at the University of Victoria.

The major issue: Those studies have generally focused on older adults and failed to account for people's lifetime drinking habits. So moderate drinkers were compared with "abstainer" and "occasional drinker" groups that included some older adults who had quit or cut down on drinking because they'd developed any number of health conditions.

That makes people who continue to drink look much healthier by comparison, And in this case, the researchers noted, looks are deceiving.

Part 1

For the analysis,  researchers identified 107 published studies that followed people over time and looked at the relationship between drinking habits and longevity. When the researchers combined all the data, it looked like light to moderate drinkers (that is, those who drank between one drink per week and two per day) had a 14% lower risk of dying during the study period compared with abstainers.

Things changed, however, when the investigators did a deeper dive. There were a handful of "higher quality" studies that included people who were relatively young at the outset (younger than 55, on average) and that made sure former and occasional drinkers were not considered "abstainers." In those studies, moderate drinking was not linked to a longer life.

Instead, it was the "lower quality" studies (older participants, no distinction between former drinkers and lifelong abstainers) that did link moderate drinking to greater longevity.

"If you look at the weakest studies," the researchers said, "that's where you see health benefits."

Part 2

The notion that moderate drinking leads to a longer, healthier life goes back decades. As an example, the scientists pointed to the "French paradox"—the idea, popularized in the 1990s, that red wine helps explain why the French enjoy relatively low rates of heart disease, despite a rich, fatty diet. That view of alcohol as an elixir still seems to be "ingrained" in the public imagination, Stockwell noted.

In reality, they said, moderate drinking likely does not extend people's lives—and, in fact, carries some potential health hazards, including increased risks of certain cancers. That's why no major health organization has ever established a risk-free level of alcohol consumption.

"There is simply no completely 'safe' level of drinking," the researchers confirm.

Stockwell, T., et al. Why do only some cohort studies find health benefits from low volume alcohol use? A systematic review and meta-analysis of study characteristics that may bias mortality risk estimates. Journal of Studies on Alcohol and Drugs (2024). DOI: 10.15288/jsad.23-00283. www.jsad.com/doi/10.15288/jsad.23-00283

New study confirms mammal-to-mammal avian flu spread

A new study provides evidence that a spillover of avian influenza from birds to dairy cattle across several U.S. states has now led to mammal-to-mammal transmission—between cows and from cows to cats and a raccoon.

This is one of the first times that we are seeing evidence of efficient and sustained mammalian-to-mammalian transmission of highly pathogenic avian influenza H5N1.

Whole genome sequencing of the virus did not reveal any mutations in the virus that would lead to enhanced transmissibility of H5N1 in humans, although the data clearly shows mammal-to-mammal transmission, which is concerning as the virus may adapt in mammals.

So far, 11 human cases have been reported in the U.S., with the first dating back to April 2022, each with mild symptoms: four were linked to cattle farms and seven have been linked to poultry farms, including an outbreak of four cases reported in the last few weeks.

Part1

These recent patients fell ill with the same strain identified in the study as circulating in dairy cows, leading the researchers to suspect that the virus likely originated from dairy farms in the same county.

While the virus does have the ability to infect and replicate in people, the efficiency of those infections is low.

How epigenetics influence memory formation

When we form a new memory, the brain undergoes physical and functional changes known collectively as a "memory trace." A memory trace represents the specific patterns of activity and structural modifications of neurons that occur when a memory is formed and later recalled.

But how does the brain "decide" which neurons will be involved in a memory trace? Studies have suggested that the inherent excitability of neurons plays a role, but the currently accepted view of learning has neglected to look inside the command center of the neuron itself, its nucleus. In the nucleus, there seems to be another dimension altogether that has gone unexplored: epigenetics.

Inside every cell of a given living organism, the genetic material encoded by the DNA is the same, yet the various cell types that make up the body, like skin cells, kidney cells, or nerve cells each express a different set of genes. Epigenetics is the mechanism of how cells control such gene activity without changing the DNA sequence.

Now, scientists  have explored whether epigenetics might affect the likelihood of neurons to be selected for memory formation. Their research on mice, published in Science, shows that the epigenetic state of a neuron is key to its role in memory encoding.

The researchers  wondered if epigenetic factors could influence the "mnemonic" function of a neuron. A neuron can be epigenetically open when the DNA inside its nucleus is unraveled or relaxed; and closed when the DNA is compact and tight.

They found that it is the open ones that are more likely to be recruited into the "memory trace," the sparse set of neurons in the brain that shows electrical activity when learning something new. Indeed, the neurons that were in a more open chromatin state were also the ones demonstrating higher electrical activity.

The 

scientists then used a virus to deliver epigenetic enzymes to artificially induce openness of the neurons. They found that the corresponding mice learned much better. When the scientists used the opposite approach to close the neurons' DNA, the mice's ability to learn was canceled.

The findings open up new ways to understand learning that encompass the neuron's nucleus, and may even lead one day to medication for improving learning.

Giulia Santoni et al, Chromatin plasticity predetermines neuronal eligibility for memory trace formation, Science (2024). DOI: 10.1126/science.adg9982. www.science.org/doi/10.1126/science.adg9982

Fecal matter transplant helps half of patients with GI cancers overcome immunotherapy resistance

Findings from a small, proof-of-concept clinical trial have suggested that fecal microbiota transplants (FMTs) can boost the effectiveness of immunotherapy in a range of gastrointestinal cancers.

In the study, published July 25 in the journal Cell Host & Microbe, six of 13 patients who had previously shown resistance to immune checkpoint inhibitors benefited from receiving FMTs from donors who had previously responded to treatment. The investigators also identified specific strains of bacteria associated with better or worse responses to FMT and immune checkpoint drugs.

This research highlights the complex interplay between beneficial and detrimental bacteria within the gut microbiota in determining treatment outcomes.

Immune checkpoint inhibitors have revolutionized cancer treatment, but many patients never respond or develop resistance after an initial response. The researchers decided to study FMT in patients receiving immune checkpoint inhibitors because emerging evidence suggests that the gut microbiota plays a crucial role in modulating the immune system and can significantly impact the efficacy of these therapies.

Part 1

This study is the first to show the potential benefits of this treatment in clinical settings beyond melanoma.

The trial included patients with metastatic solid-tumor cancers who were resistant to the anti-PD-1 drug nivolumab. Four had gastric cancer, five had esophageal cancer, and four had hepatocellular carcinoma.

The six FMT donors, who also had gastric cancer, esophageal cancer, or hepatocellular carcinoma, had had a complete or partial response for at least six months after treatment with nivolumab or pembrolizumab. The FMTs were given via colonoscopy after the recipients had received antibiotics to tamp down their own microbiotas.
One of the most surprising results was from a hepatocellular carcinoma patient who initially showed no response to the first FMT and continued to experience cancer progression. However, after switching the donor for the second FMT, the patient exhibited remarkable tumor shrinkage.
The investigators then took a closer look at which bacteria were most likely to affect whether patients benefited from FMT combined with checkpoint inhibitors. In doing so, they identified a novel bacterial strain that helped to improve FMT efficacy, Prevotella merdae Immunoactis.

They also identified two strains that had a detrimental impact on FMT efficacy, Lactobacillus salivarius and Bacteroides plebeius.

They plan to continue studying these and other strains with the goal of developing better ways to boost immunotherapy effectiveness by altering the gut microbiota.
By examining the complex interactions within the microbiome, the researchers hope to identify optimal microbial communities that can be used to enhance cancer treatment outcomes.
This comprehensive approach will help us understand how the microbial ecosystem as a whole contributes to therapeutic success.
Fecal microbiota transplantation improves anti-PD-1 inhibitor efficacy in refractory unresectable or metastatic solid cancers refractory to anti-PD-1 inhibitor, Cell Host & Microbe (2024). DOI: 10.1016/j.chom.2024.06.010. www.cell.com/cell-host-microbe … 1931-3128(24)00228-2

Fears over viral infection during pregnancy
The 2015-2016 outbreak of the Zika virus caused thousands of birth defects among Brazilians infected during pregnancy; now the country is facing the same fears with the Oropouche virus. Brazil’s health ministry has reported four cases of microcephaly — a type of reduced brain development — in newborns of infected mothers and one fetal death that might be associated with the virus. Oropouche is transmitted by Culicoides paraensis, a tiny midge found across the Americas. Cases of Oropouche fever have surged in Brazil since late 2022. The cases are worrisome and a sign to be alert.

https://www.science.org/content/article/virus-spreading-in-latin-am...

Stolen bacterial genes defeat fungus

Microscopic freshwater animals, just half a millimetre long, have perfected the trick of stealing genes from bacteria, allowing them to fight off infections and survive for millions of years without sex. These unusual creatures, bdelloid rotifers, are all females and 10% of their genes come from foreign organisms. Asexual reproduction should leave them vulnerable to pathogens but some of the ‘borrowed genes’ code for bacterial enzymes known as synthetases, w... — helping the rotifers to defeat fungal infections.

https://www.nature.com/articles/s41467-024-49919-1?utm_source=Live+...

Hungry fungi clean up contamination

A growing number of biotech companies are investing in fungal treatments that break down environmental contaminants — from.... Fungi tend to be better than bacteria at tackling large, complex chemicals like the hydrocarbons in many plastics, although this sometimes requires combining different strains of fungi to perform different steps of the process. They can be applied directly to contaminated soil or water, as well as used to break down plastic-based garbage like carpets or mattresses.

https://www.nature.com/articles/s41587-024-02315-y.epdf?sharing_tok...

Scientists figure out why there are so many colorful birds in the tropics and how these colours spread over time

The color palette of the birds you see out your window depends on where you live. If you're far from the Equator, most birds tend to have drab colors, but the closer you are to the tropics, you'll probably see more and more colorful feathers.

Scientists have long been puzzled about why there are more brilliantly-colored birds in the tropics than in other places, and they've also wondered how those brightly-colored birds got there in the first place: that is, if those colorful feathers evolved in the tropics, or if tropical birds have colorful ancestors that came to the region from somewhere else.

In a study published in the journal Nature Ecology and Evolution, scientists built a database of 9,409 birds to explore the spread of color across the globe.

They found that iridescent, colorful feathers originated 415 times across the bird tree of life, and in most cases, arose outside of the tropics– and that the ancestor of all modern birds likely had iridescent feathers, too.

There are two main ways that color is produced in animals: pigments and structures. Cells produce pigments like melanin, which is responsible for black and brown coloration. Meanwhile, structural color comes from the way light bounces off different arrangements of cell structures. Iridescence, the rainbow shimmer that changes depending how light hits an object, is an example of structural colour.

Tropical birds get their colors from a combination of brilliant pigments and structural color.

Researchers  combed through photographs, videos, and even scientific illustrations of 9,409 species of birds— the vast majority of the 10,000-ish living bird species known to science. The researchers kept track of which species have iridescent feathers, and where those birds are found.

The scientists then combined their data on bird coloration and distribution with a pre-existing family tree, based on DNA, showing how all the known bird species are related to each other. They fed the information to a modeling system to extrapolate the origins and spread of iridescence.

Given how modern species are related to each other and where they're found, and overall patterns of how species form and how traits like colors change over time, the modeling software determined the most likely explanation for the bird colors we see today: colorful birds from outside the tropics often came to the region millions of years ago, and then branched out into more and more different species. The model also revealed a surprise about the ancestor of all modern birds.

Part 1

Birds are a specialized group of dinosaurs— the earliest known bird, Archaeopteryx, lived 140 million years ago. A sub-group of birds called Neornithes evolved 80 million years ago, and this group became the only birds (and dinosaurs) to survive the mass extinction 66 million years ago.
All modern birds are members of Neornithes.The model produced by researchers now suggests that the common ancestor of all Neornithes, 80 million years ago, had iridescent feathers that still glitter across the bird family tree.
Researchers found fossil evidence of iridescent birds and other feathered dinosaurs before, by examining fossil feathers and the preserved pigment-producing structures in those feathers. So we know that iridescent feathers existed back in the Cretaceous—those fossils help support the idea from this new model that the ancestor of all modern birds was iridescent too.
The discovery that the first Neornithes was likely iridescent could have important implications for paleontology.

Transitions between colour mechanisms affect speciation dynamics and range distributions of birds, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02487-5

Part 2

Ice 0: Researchers discover a new mechanism for ice formation

Ice is far more complicated than most of us realize, with over 20 different varieties known to science, forming under various combinations of pressure and temperature. The kind we use to chill our drinks is known as ice I, and it's one of the few forms of ice that exist naturally on Earth.

Researchers have recently discovered another type of ice: ice 0, an unusual form of ice that can seed the formation of ice crystals in supercooled water.

The formation of ice near the surface of liquid water can start from tiny crystal precursors with a structure similar to a rare type of ice, known as ice 0.

In a study published in Nature Communications, researchers showed that these ice 0-like structures can cause a water droplet to freeze near its surface rather than at its core. This discovery resolves a longstanding puzzle and could help redefine our understanding of how ice forms.

Crystallization of ice, known as ice nucleation, usually happens heterogeneously, or in other words, at a solid surface. This is normally expected to happen at the surface of the water's container, where liquid meets solid.

However, this new research shows that ice crystallization can also occur just below the water's surface, where it meets the air. Here, the ice nucleates around small precursors with the same characteristic ring-shaped structure as ice 0.

Simulations have shown that a water droplet is more likely to crystallize near the free surface under isothermal conditions. This resolves a longstanding debate about whether crystallization occurs more readily on the surface or internally.

Ice 0 precursors have a structure very similar to supercooled water, allowing water molecules to crystallize more readily from it, without needing to directly form themselves into the structure of regular ice.

The tiny ice 0 precursors are formed spontaneously, as a result of negative pressure effects caused by the surface tension of water. Once crystallization begins from these precursors, structures similar to ice 0 quickly rearrange themselves into the more familiar ice I.

Surface-induced water crystallization driven by precursors formed in negative pressure regions, Nature Communications (2024). DOI: 10.1038/s41467-024-50188-1

New aerospace and building materials could repair themselves thanks to fungi and bacteria

Researchers are using biological matter to create unique new materials that can adapt to their environment and repair themselves.

Researchers are developing what they call "living materials," for use in the aerospace and transportation sectors. These living materials are, precisely as they sound, literally alive. They contain microorganisms such as fungi and bacteria, which give them the capacity to sustain their integrity and self-healing.

The goal is to make engineered structures that can behave like living organisms, able to sense and adapt to mechanical stresses.

The material they are developing is a composite that combines living fungi cells and wood. It consists of a hydrogel and mycelium, a root-like structure of a fungus that normally lives underground.

They chose to work with fungi because fungus is a really robust organism, it is tolerant to harsh conditions and is relatively easy to cultivate. 

Moreover, fungal cells have a great ability to connect. Mycelium can grow a vast sensing network that allows it to send signals throughout the organism. That means the scientists can distribute only a few cells throughout the material, and these cells will reconnect and form a sensing network.

Biological materials could help to improve the performance and durability of critical structures used in areas like aerospace and transportation.

These materials are very lightweight and more sustainable than currently used materials. 

Sources: 

• AM-IMATE
• ARCHISKIN
• EU research and innovation for chemicals and advanced materials

Scientists control bacterial mutations to preserve antibiotic effectiveness

Scientists have discovered a way to control mutation rates in bacteria, paving the way for new strategies to combat antibiotic resistance.

Antibiotics are given to kill bad bacteria; however, with just one mutation a bacteria can evolve to become resistant to that antibiotic, making common infections potentially fatal.

The new research, published recently in the journal PLOS Biology, used high-performance computing to simulate more than 8,000 years of bacterial evolution, allowing scientists to predict mechanisms that control mutation rates.

They then made more than 15,000 cultures of E. coli in lab conditions to test their predictions—that's so many that if you lined up all of the bacteria in this study, they would stretch 860,000 km, or wrap around the Earth more than 20 times.

The tests revealed that bacteria living in a lowly populated community are more prone to developing antibiotic resistance due to a naturally occurring DNA-damaging chemical, peroxide. In crowded environments, where cells are more densely packed, bacteria work collectively to detoxify peroxide, reducing the likelihood of mutations that lead to antibiotic resistance.

The finding could help develop "anti-evolution drugs" to preserve antibiotic effectiveness by limiting the mutation rates in bacteria.

By understanding the environmental conditions that influence mutation rates, we can develop strategies to safeguard antibiotic effectiveness. This new study shows that bacterial mutation rates are not fixed and can be manipulated by altering their surroundings, which is vital on our journey to combat antibiotic resistance.

Peroxide, a chemical found in many environments, is key to this process. When E. coli populations become denser, they work together to lower peroxide levels, protecting their DNA from damage and reducing mutation rates. The study showed that genetically modified E. coli that is unable to break down peroxide had the same mutation rates, no matter the population size. However, when helper cells that could break down peroxide were added, the mutation rate in these genetically modified E. coli decreased.

Rowan Green et al, Collective peroxide detoxification determines microbial mutation rate plasticity in E. coli, PLOS Biology (2024). DOI: 10.1371/journal.pbio.3002711

Komodo Dragon Teeth Have Iron Caps For Sharpness, Scientists Discover

As if komodo dragons weren't amazing enough, these giant lizards literally have teeth of iron.

A new study of these formidable predators' chompers has revealed concentrated deposits of iron along the serrated tearing edges and the tips of their teeth, helping to keep them razor-sharp for tearing the flesh from the prey they devour.

Although many vertebrates have iron enhancements in their teeth, komodo dragons (Varanus komodoensis) and other similar species with serrated teeth, called ziphodonts, represent the most striking examples found to date.
In fact, so much iron is concentrated along the sharp edges of komodo teeth that they are tinted orange.

Never before has iron been found so localized along the cutting edge of a vertebrate tooth. This suggests that a stronger cutting edge confers a competitive advantage, and may yield insights into how some of the fiercest dinosaurs devoured their food.

https://www.nature.com/articles/s41559-024-02477-7

Biologists discover human-infecting parasite produces sterile soldiers like ants and termites

Neuroscientists discover brain circuitry of placebo effect for pain relief

Signs of Ancient Life on Mars?

NASA’s Perseverance rover has made very compelling observations in a Martian rock that, with further study, could prove that life was present on Mars in the distant past – but how can we determine that from a rock, and what do we need to do to confirm it? Morgan Cable, a scientist on the Perseverance team, takes a closer look.

Trees reveal climate surprise: Microbes living in bark remove methane from the atmosphere

Tree bark surfaces play an important role in removing methane gas from the atmosphere, according to a study published 24 July in Nature.

While trees have long been known to benefit the climate by removing carbon dioxide from the atmosphere, this new research reveals a surprising additional climate benefit. Microbes hidden within tree bark can absorb methane—a powerful greenhouse gas—from the atmosphere.

An international team of researchers has shown for the first time that microbes living in bark or in the wood itself are removing atmospheric methane on a scale equal to or above that of soil. They calculate that this newly discovered process makes trees 10% more beneficial for climate overall than previously thought.

Methane is responsible for around 30% of global warming since pre-industrial times and emissions are currently rising faster than at any point since records began in the 1980s.

Although most methane is removed by processes in the atmosphere, soils are full of bacteria that absorb the gas and break it down for use as energy. Soil had been thought of as the only terrestrial sink for methane, but researchers now show that trees may be as important, perhaps more so.

Vincent Gauci, Global atmospheric methane uptake by upland tree woody surfaces, Nature (2024). DOI: 10.1038/s41586-024-07592-w. www.nature.com/articles/s41586-024-07592-w

New study links brain microstructure to gender differences in mental health

A team of neuroscientists and behavioral specialists has found differences between male and female brain structure in areas associated with decision-making, memory processing and handling emotions.

In their study, published in the Proceedings of the National Academy of Sciences, the group compared more than 1,000 brain scans to better understand why men and women are more prone to different kinds of brain illness.

Prior research has shown that male babies are three times as likely to be diagnosed with autism as they grow older than are female babies—they are also twice as likely to be diagnosed with ADHD. On the other hand, female babies are almost twice as likely to be diagnosed with anxiety or mood disorders later in life than are boys.

Mental health specialists have wondered for many years why there are differences, and many suspect that it is due to physical brain differences between the genders. The research team thinks they may have found evidence for such differences.

To spot possible gender differences in the brain, the researchers focused their attention on subcortical gray matter regions that prior researchers have associated with mental health, including the amygdala and the thalamus. They then analyzed MRI scans of 1,065 male and female brains, looking for differences in brain microstructure, such as the way cells are concentrated, their arrangement or even their physical characteristics.

The research team found what they describe as "large, sex-related differences in microstructures." They noted that such changes were still apparent after adjusting for age and the relative size of the brains under study. They also found diffusion metrics in the amygdala and thalamus that they believe could be associated with mental disorders such as anxiety, ADHD, social skills issues and depression.

They suggest that further study of diffusion MRI imagery could provide more insight into gender-based brain disorders.

Richard Watts et al, Sex and mental health are related to subcortical brain microstructure, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2403212121. www.pnas.org/doi/full/10.1073/pnas.2403212121

NASA streams first 4K video from aircraft to space station and back

A team at NASA's Glenn Research Center in Cleveland has streamed 4K video footage from an aircraft to the International Space Station and back for the first time using optical (laser) communications. The feat was part of a series of tests on new technology that could provide live video coverage of astronauts on the moon during the Artemis missions.

Historically, NASA has relied on radio waves to send information to and from space. Laser communications use infrared light to transmit 10 to 100 times more data faster than radio frequency systems.

Working with the Air Force Research Laboratory and NASA's Small Business Innovation Research program, Glenn engineers temporarily installed a portable laser terminal on the belly of a Pilatus PC-12 aircraft. They then flew over Lake Erie, sending data from the aircraft to an optical ground station in Cleveland. From there, it was sent over an Earth-based network to NASA's White Sands Test Facility in Las Cruces, New Mexico, where scientists used infrared light signals to send the data.

The signals traveled 22,000 miles away from Earth to NASA's Laser Communications Relay Demonstration (LCRD), an orbiting experimental platform. The LCRD then relayed the signals to the ILLUMA-T (Integrated LCRD LEO User Modem and Amplifier Terminal) payload mounted on the orbiting laboratory, which then sent data back to Earth. During the experiments, High-Rate Delay Tolerant Networking (HDTN), a new system developed at Glenn, helped the signal penetrate cloud coverage more effectively.

After each flight test, the team continuously improved the functionality of their technology.

Source: NASA

Part 2

Blood thinner stops cobra venom
A common blood thinner can fight the toxins in cobra venom, potentially preventing limb amputations caused by snakebites. Using the genetic editing tool CRISPR, researchers found that eliminating certain sugars on the outside of human cells allowed the cells to resist cobra toxins. In experiments with mice, a class of drugs known as heparinoids soaked up the toxin and shrank venom-induced wounds by 94%. The drugs worked against several cobra species’ venoms, but not against viper venoms.

https://www.science.org/doi/10.1126/scitranslmed.adk4802?utm_source...

A passive, renewable, more efficient way to extract water from the atmosphere

Freshwater scarcity affects  billions of people in the world, primarily in arid and remote regions, as well as islands and coastal areas without freshwater sources. Climate change and population growth are only making the problem worse, and existing methods require an energy input, usually electrical.

Renewable energy can fix this and is required for these regions for drinking water and irrigation, using water extracted from the atmosphere.

It is estimated the atmosphere holds about 13 trillion tons of water, six times the freshwater in the globe's rivers; global warming allows the air to hold more water vapor, by a theoretical 7% per degree Celsius of warming.

Now engineers and scientists  have created a system that uses  solar energy to extract as much as 3 liters (0.8 gallons) of water per square meter per day from air, in a purely passive way, requiring no maintenance or human operators. The study is published in the journal Nature Communications.

Existing solar-driven atmospheric water extraction (SAWE) systems typically rely on absorbing water vapor from the air. When the absorbing material reaches saturation, the system is sealed and exposed to sunlight, which begins the release of the captured water. They are an improvement over passive atmospheric water technologies such as fog and dew collection, and more available in other geographies and sites with climate constraints.

To design a passive, efficient, easily scalable and minimal-labor system, the group used a structure of multiple vertical microchannels, called mass transport bridges. The tubes, sitting in a container, are filled with a liquid salt solution that acts as a liquid absorber; they used lithium chloride.

Depending on the temperature distribution, the ambient temperature region, exposed to the environment, continuously captures atmospheric water and stores it in a container. When the system receives sunlight, the absorber converts the light into heat and generates concentrated water vapor in the high-temperature region.

The water vapor condenses on the chamber wall, producing freshwater. More captured water from the absorber's container moves uninterrupted to the high-temperature region.

At the same time, the concentrated liquid in the high-temperature region is transported back to the ambient temperature region via diffusion—the movement of molecules from a region of high concentration to low concentration—and by convection—the movement of the hotter, lower density solution through the colder, denser regions—enabling continuous capture of water vapor as long as sunlight is available.

Kaijie Yang et al, A solar-driven atmospheric water extractor for off-grid freshwater generation and irrigation, Nature Communications (2024). DOI: 10.1038/s41467-024-50715-0

Virus that causes COVID-19 is widespread in wildlife

SARS-CoV-2, the virus responsible for COVID-19, is widespread among wildlife species, according to  new research published July 29, 2024 in Nature Communications. The virus was detected in six common backyard species, and antibodies indicating prior exposure to the virus were found in five species, with rates of exposure ranging from 40 to 60% depending on the species.

Genetic tracking in wild animals confirmed both the presence of SARS-CoV-2 and the existence of unique viral mutations with lineages closely matching variants circulating in humans at the time, further supporting human-to-animal transmission, the study found.

The highest exposure to SARS CoV-2 was found in animals near hiking trails and high-traffic public areas, suggesting the virus passed from humans to wildlife, according to scientists.

The findings highlight the identification of novel mutations in SARS-CoV-2 in wildlife and the need for broad surveillance, researchers say. These mutations could be more harmful and transmissible, creating challenges for vaccine development.

The scientists stressed, however, that they found no evidence of the virus being transmitted from animals to humans, and people should not fear typical interactions with wildlife.

Widespread exposure to SARS-CoV-2 in wildlife communities, Nature Communications (2024). DOI: 10.1038/s41467-024-49891-w

Losing a loved one may speed up aging, study finds

Losing someone close, like a family member, can make you age faster, says a new study.

The study found that people who lost a parent, partner, sibling, or child, showed signs of older biological age compared to those who hadn't experienced such losses. The research was published in JAMA Network Open.

Biological aging is the gradual decline in how well your cells, tissues, and organs function, leading to a higher risk of chronic diseases. Scientists measure this type of aging using DNA markers known as epigenetic clocks.

The study suggests that the impact of loss on aging can be seen long before middle age and may contribute to health differences among racial and ethnic groups.

The study also confirmed that people who experienced two or more losses had older biological ages according to several epigenetic clocks. Experiencing two or more losses in adulthood was more strongly linked to biological aging than one loss and significantly more so than no losses.

Losing a parent or sibling early in life can be very traumatic, often leading to mental health issues, cognitive problems, higher risks of heart disease, and a greater chance of dying earlier. Losing a close family member at any age poses health risks, and repeated losses can increase the risks of heart disease, mortality, and dementia; and impacts may persist or become apparent long after the event.

Familial Loss of a Loved One and Biological Aging, JAMA Network Open (2024).

 https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2821615

Origins of matter in the early universe

The early universe was 250,000 times hotter than the core of our sun. That's far too hot to form the protons and neutrons that make up everyday matter. Scientists recreate the conditions of the early universe in particle accelerators by smashing atoms together at nearly the speed of light.

Measuring the resulting shower of particles allows scientists to understand how matter formed. The particles that scientists measure can form in various ways: from the original soup of quarks and gluons or from later reactions.

These later reactions began 0.000001 seconds after the Big Bang, when the composite particles made of quarks began to interact with each other.

A new calculation determined that as much as 70% of some measured particles are from these later reactions, not from reactions similar to those of the early universe. The research is published in the journal Physics Letters B.

This finding improves scientific understanding of the origins of matter. It helps identify how much of the matter around us formed in the first few fractions of a second after the Big Bang, versus how much matter formed from later reactions as the universe expanded.

This result implies large amounts of the matter around us formed later than expected. To understand the results of collider experiments, scientists must discount the particles formed in the later reactions.

Only those formed in the subatomic soup reveal the early conditions of the universe. This new calculation shows that the number of measured particles formed in reactions is much higher than expected.

Joseph Dominicus Lap et al, Hadronic J/ψ regeneration in Pb+Pb collisions, Physics Letters B (2023). DOI: 10.1016/j.physletb.2023.138246

Don't close your borders: Countries need to cooperate on migration as climate crisis worsens

Humanity must rethink migration as the climate crisis drives rapid global changes, researchers say.

With significant migration expected—and border policies hardening—the researchers say the "time is ripe to highlight the benefits of collaboration between nations and regions."

By promoting the benefits of migration, especially in an era of aging populations, global leaders could ensure a better future for people and societies.

The paper, titled "Anticipating the global redistribution of people and property" and published in the journal One Earth, comes from an international team of climate and social scientists. 

Millions of people are projected to be displaced by sea-level rise in the next decades, and 2 billion could be exposed to extreme heat beyond their experience by the end of the century.

Ignoring or downplaying the inevitable global redistribution of people would lead to geo-political instability, and a polarized and fractured world.

"Instead, the international community must come together to rethink mobility and cultural integration to ensure a benign transition to this new world."

So far, most migration with significant climate dimensions has happened within countries, with people leaving areas affected by long-term decline in agricultural productivity or escaping conditions such as coastal erosion or extreme events.

While some large nations have different climate zones that can accommodate this, small countries do not.

The paper also warns that a "skewed distribution of wealth and associated power" makes it difficult for people to move, both within and between states.

Global warming exacerbates existing inequalities, making habitability a major political challenge of this century.

"Concrete cooperation is now needed to match migrant flows with demand for labor, to the benefit of the Global South and the developed world alike.

The paper says major reform of the food system, supported by movement of workers, could increase production while conserving nature.

Migration can therefore be a win–win for people and the climate, but leaders must make a positive case for economic benefits and effective integration. "Playing up the social costs of migration appeals to national identity motivations, but fails to overcome problems from aging populations.

Instead, leaders should focus on the economic and social benefits of new populations and effective integration, which benefits newcomers and original inhabitants alike.

"Every corner of the world needs to anticipate the coming climate crisis and promote the safe and beneficial movement of people as conditions change.

It is the question of survival and you can't stop people from moving when their very existence is under threat. 

Marten Scheffer et al, Anticipating the global redistribution of people and property, One Earth (2024). DOI: 10.1016/j.oneear.2024.06.008

You 

Why the solar corona is so much hotter than sun's surface

In a new study published in The Astrophysical Journal,  researchers explore critical aspects of a phenomenon called kinetic Alfvén waves (KAWs) to provide fresh insights into an age-old heliophysics mystery.

They examined the potentially pivotal role of KAWs in heating the solar corona, moving science one step closer to solving the puzzle of why the corona is many times hotter than the surface of the sun itself.

For decades, Alfvén waves have been proven to be the best candidates for transporting energy from one place to another. 

This paper utilizes a novel approach to model energetic particles in space plasmas, as observed by satellites like Viking and Freja, to answer how the electromagnetic energy of the waves, interacting with particles, transforms into heat during the damping process as the waves move through space.

The corona, or solar atmosphere, is an enigmatic region surrounding our home star that extends far beyond the visible disk of the sun, stretching some 8 million kilometers above the sun's surface. Yet, the corona is also characterized by extraordinarily high temperatures, a mystery that has captivated astrophysicists for nearly seventy years.

This new work  offers important insights into the critical problem of how energy in a magnetic field is transformed to heat a plasma comprising charged particles like protons and electrons.

Kinetic Alfvén waves—abundant throughout the plasma universe—are oscillations of the ions and magnetic field as they move through the solar plasma. The waves are formed by motions in the photosphere, the sun's outer shell that radiates visible light.

Part 1

The researchers focused on the heating and energy exchange facilitated by KAWs. The reason for the great interest in these waves lies in their ability to transport energy. Observational data from numerous spacecraft and theoretical investigations have consistently demonstrated that KAWs dissipate and contribute to solar coronal heating during their propagation in space.
Because of these unique properties, the waves provide a critical mechanism for transferring energy, important to understanding the energy exchange between electromagnetic fields and plasma particles.
KAWs operate on small kinetic scales and are capable of supporting parallel electric and magnetic field fluctuations, enabling an energy transfer between the wave field and plasma particles through a phenomenon called Landau interactions.
The present work utilized and explores the Landau damping mechanism, which occurs when particles moving parallel to a wave have velocities comparable to the wave's phase velocity.
Landau damping is an exponential decrease as a function of time of particular waves in plasma. "When particles interact with the wave, they receive/lose energy—a term called 'resonant condition.
Part 2

This can result in the wave either delivering its energy to the particles or gaining energy from them, causing the particles to either damp or grow.
This new research work finds that KAWs rapidly dissipate, completely transferring their energy to plasma particles in the form of heating. This energy transfer accelerates the particles over longer spatial distances, significantly impacting the dynamics of the plasma.
The analytical insights gleaned from this study will find practical application in understanding phenomena within the solar atmosphere, particularly shedding light on the significant role played by non-thermal particles in the heating processes.

 Syed Ayaz et al, Solar Coronal Heating by Kinetic Alfvén Waves, The Astrophysical Journal (2024). DOI: 10.3847/1538-4357/ad5bdc

Part 3

**

 Chimpanzees  are capable of speech

Axel G. Ekström et al, Chimpanzee utterances refute purported missing links for novel vocalizations and syllabic speech, Scientific Reports (2024). DOI: 10.1038/s41598-024-67005-w

How to cope with increasingly hot summers

• Use an electric fan, a particularly effective method in humid climates like Quebec's. But remember: using a fan can be counter-productive in very low humidity or above 40° C temperatures.
• Sponge yourself regularly with cool water.
• Soak your feet in cold water.
• Stay socially connected (especially important for seniors and the socially isolated).
• Set your air conditioner to 25° C instead of 20° C to build up your tolerance to higher temperatures (and reduce energy consumption).

Confirmed link between maternal asthma and child allergies

For the first time, researchers  have confirmed maternal asthma increases risks of child allergies.

In a systematic review of more than 20,000 sources, the researchers discovered children whose mothers have asthma are 76% more likely to have the condition themselves.

The review is the first time anyone has brought together the data on how severity and control of asthma during pregnancy affects allergy and asthma outcomes in children. It also found that better asthma control during pregnancy reduces the risk in children.

They found found maternal asthma is associated with an increased risk of wheeze (59%), food allergy (32%), eczema (17%) and hay fever (18%),

The findings are published in the BJOG: An International Journal of Obstetrics & Gynaecology.

Associations between maternal asthma and risks of progeny asthma were similar when the exposure was maternal asthma during the index pregnancy or as a history of asthma, consistent with the chronic nature of asthma.

Uncontrolled and more severe maternal asthma during the index pregnancy were also associated with increased risk of progeny asthma.

Andrea J. Roff et al, Maternal asthma during pregnancy and risks of allergy and asthma in progeny: A systematic review and meta‐analysis, BJOG: An International Journal of Obstetrics & Gynaecology (2024). DOI: 10.1111/1471-0528.17900

Blocking One Protein Extends Lifespan in Mice by Up to 25%

A protein called interleukin 11 (IL-11) appears to play a crucial role in aging, with scientists extending the lifespans of mice by up to 25 percent simply by blocking the molecule's effects.

Researchers  used genetic engineering to turn off IL-11 production in a sample of mice, while injecting other mice with an anti-IL-11 drug.

Deaths from cancer and tumorous growths were reduced in both groups, while health conditions related to the effects of aging – including chronic inflammation and poor metabolism – were also less common.

The treated mice had fewer cancers, and were free from the usual signs of aging and frailty, but researchers also saw reduced muscle wasting and improvement in muscle strength. In other words, the old mice receiving anti-IL-11 were healthier.

Interleukin 11 has been of interest to scientists studying the aging process for several years. We know that it builds up in the body as we get older, and it's linked to increasing levels of inflammation, scar tissue, and overall frailty.

https://www.nature.com/articles/s41586-024-07701-9

First, keep your head back with your ears submerged to keep your airways open. Resist the urge to panic, try to relax and breathe normally. Gently move your hands paddling them as this will aid in keeping afloat. Don't fret if your legs sink, everyone's buoyancy is different. Finally, spread your arms and legs as this really helps maintain your stability in the water.

More women are ending pregnancies on their own, a new study suggests. Some resort to unsafe methods

A growing number of women said they've tried to end their pregnancies on their own by doing things like taking herbs, drinking alcohol or even hitting themselves in the belly, a new study suggests.

Researchers surveyed reproductive-age women in the U.S. before and after the Supreme Court overturned Roe v. Wade in June 2022. The proportion who reported trying to end pregnancies by themselves rose from 2.4% to 3.3%.

A lot of people are taking things into their own hands.

Study authors acknowledged that the increase is small. But the data suggests that it could number in the hundreds of thousands of women.

Researchers surveyed about 7,000 women six months before the Supreme Court decision, and then another group of 7,100 a year after the decision. They asked whether participants had ever taken or done something on their own to end a pregnancy. Those who said yes were asked follow-up questions about their experiences.

The data show that making abortion more difficult to access is not going to mean that people want or need an abortion less frequently.

Women gave various reasons for handling their own abortions, such as wanting an extra measure of privacy, being concerned about the cost of clinic procedures and preferring to try to end their pregnancies by themselves first.

They reported using a range of methods. Some took medications—including emergency contraception and the abortion pills misoprostol and mifepristone obtained outside the medical system and without a prescription. Others drank alcohol or used drugs. Some resorted to potentially harmful physical methods such as hitting themselves in the abdomen, lifting heavy things or inserting objects into their bodies.

Some respondents said they suffered complications like bleeding and pain and had to seek medical care afterward. Some said they later had an abortion at a clinic. Some said their pregnancies ended after their attempts or from a later miscarriage, while others said they wound up continuing their pregnancies when the method didn't work.

Respondents may be under-reporting their abortions because researchers are asking them about "a sensitive and potentially criminalized behaviour."

 The study's findings confirm the statement : If you make it hard to get (an abortion) in a formal setting, people will just do it informally.

Lauren Ralph et al, Self-Managed Abortion Attempts Before vs After Changes in Federal Abortion Protections in the US, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.24310

Study finds working from home stifles innovation

Remote and hybrid working may be great for employees' work-life balance, but it may be stifling innovation, according to new research.

The study found that staff who worked in a hybrid model were less likely to come up with innovative ideas than colleagues who always worked in the office. And staff working from home tended to produce lower quality innovative ideas than those who always worked in the office. 

Innovation in the workplace can occur through random, spontaneous 'watercooler' conversations between employees. However, these 'productive accidents' are less likely to occur when employees work from home. This  research work has found that innovation is suffering as a result.

Michael Gibbs et al, Employee innovation during office work, work from home and hybrid work, Scientific Reports (2024). DOI: 10.1038/s41598-024-67122-6

Scientists 'Mind Controlled' Mice Remotely 

At the mere flick of a magnetic field, mice engineered with nanoparticle-activated 'switches' inside their brains were driven to feed, socialize, and act like clucky new mothers in an experiment designed to test an innovative research tool.

While 'mind control' animal experiments are far from new, they have generally relied on cumbersome electrodes tethering the subject to an external system, which not only requires invasive surgery but also sets limits on how freely the test subject can move about.
In what is claimed to be a breakthrough in neurology, researchershave developed a method for targeting pathways in the brain using a combination of genetics, nanoparticles, and magnetic fields.

They call the technology Nano-MIND, an acronym for Magnetogenetic Interface for NeuroDynamics. And while mind-control is a coarse but relatively accurate way of describing it, the system in its current form is intended to provide researchers with a means of remotely activating neural circuits for a range of research applications.

This is the world's first technology to freely control specific brain regions using magnetic fields. Magnetic stimulation is an emerging field of research in neurology, where washing the brain with pulses of electromagnetism broadly massages whole regions into subtly changing their behavior. 

To target specific circuits, the researchers took a leaf out of another field of research called optogenetics, which genetically engineers mechanisms into cells that can be readily activated by a light source. In this case, the team integrated ion channels into targeted populations of brain cells in mice. Instead of delivering light through a localized fiber, as in optogenetics, the ion channels could be switched on magnetically with a twist of a tiny actuator. All that's required is a surrounding field that's strong enough to pull at the nanoparticle.

https://www.nature.com/articles/s41565-024-01694-2

43% of cocoa products exceed lead safety levels, study finds

When our friends, relatives and colleagues come from the US they bring lots of chocolates  and we consume them very fondly. But this new information is alarming ....

A new study  found a disquieting percentage of cocoa products in the U.S. contain heavy metals that exceed guidelines, including higher concentrations in organic products.

The study, "A Multi-Year Heavy Metal Analysis of 72 Dark Chocolate and Cocoa Pr... was published on July 31, 2024 in Frontiers in Nutrition.

Researchers analyzed 72 consumer cocoa products, including dark chocolate, every other year over an eight year period for contamination with lead, cadmium, and arsenic, heavy metals that pose a significant health hazard in sufficient amounts.

We all love chocolate but it's important to indulge with moderation, as with other foods that contain heavy metals, including large fish like tuna and unwashed brown rice. While it's not practical to avoid heavy metals in your food entirely, you must be cautious of what you are eating and how much.

The researchers used a threshold of maximum allowable dose levels to assess the extent of heavy metal contamination in an array of chocolate products, found on grocery store shelves.

Key findings:

43% of the products studied exceeded the maximum allowable dose level for lead. 35% of the products studied exceeded the maximum allowable dose level for cadmium.

None of the products exceeded the maximum allowable dose level for arsenic. Surprisingly, organic labeled products showed higher levels of both lead and cadmium compared to non-organic products.

For the average consumer, consuming a single serving of these cocoa products may not pose significant health risks based on the median concentrations found. However, consuming multiple servings or combining consumption with other sources of heavy metals could lead to exposures that exceed the maximum allowable dose level.

Foods with high lead levels may include animal foods that can bioaccumulate heavy metals (shellfish, organ meats) and foods or herbal supplements grown in contaminated soil and/or imported from countries with less regulation.  For cadmium, the main concerns are the same with the addition of some seaweeds.

Consumers should be aware of potential cumulative exposure risks, particularly with cocoa products labeled organic, as they may have higher heavy metal concentrations. A serving size of dark chocolate is typically one ounce and has been generally suggested to have health benefits including cardiovascular health, cognitive performance, and chronic inflammation.

 Study Finds Many Cocoa Products Contaminated by Heavy Metals, Frontiers in Nutrition (2024). DOI: 10.3389/fnut.2024.1366231 , www.frontiersin.org/journals/n … 024.1366231/abstract

Incidence of heart attacks and strokes was lower after COVID-19 vaccination, finds study of 46 million adults

A new study, published recently in Nature Communications and involving nearly the whole adult population of England, has found that the incidence of heart attacks and strokes was lower after COVID-19 vaccination than before or without vaccination.

Researchers analyzed de-identified health records from 46 million adults in England between 8 December 2020 and 23 January 2022. Data scientists compared the incidence of cardiovascular diseases after vaccination with the incidence before or without vaccination, during the first two years of the vaccination program.

The study showed that the incidence of arterial thromboses, such as heart attacks and strokes, was up to 10% lower in the 13 to 24 weeks after the first dose of a COVID-19 vaccine. Following a second dose, the incidence was up to 27% lower after receiving the AstraZeneca vaccine and up to 20% lower after the Pfizer/Biotech vaccine. The incidence of common venous thrombotic events—mainly pulmonary embolism and lower limb deep venous thrombosis—followed a similar pattern.

This research further supports the large body of evidence on the effectiveness of the COVID-19 vaccination program, which has been shown to provide protection against severe COVID-19 and saved millions of lives worldwide. It did not identify new adverse cardiovascular conditions associated with COVID-19 vaccination and offers further reassurance that the benefits of vaccination outweigh the risks.

The incidence of cardiovascular disease is higher after COVID-19, especially in severe cases. This may explain why the incidence of heart attacks and strokes is lower in vaccinated people compared with unvaccinated people.

Cohort study of cardiovascular safety of different COVID-19 vaccination doses among 46 million adults in England, Nature Communications (2024). DOI: 10.1038/s41467-024-49634-x

AI predicts male infertility risk with blood test, no semen needed

According to a World Health Organization (WHO) study (2017), about half of all infertility is due to men. Semen analysis is considered essential for diagnosis of male infertility, but is not readily available at medical institutions other than those specializing in infertility treatment, and there is a high threshold for receiving it.

In a new study, researchers developed an AI model that can predict the risk of male infertility without the need for semen analysis by only measuring hormone levels in a blood test. AI creation software that requires no programming was used for the model, and the study was reported in Scientific Reports.

The AI prediction model was based on data from 3,662 patients and had an accuracy rate of approximately 74%. In particular, it was 100% correct in predicting non-obstructive azoospermia, the most severe form of male infertility.

The current study collected clinical data from 3,662 men who underwent semen and hormone testing for male infertility between 2011 and 2020. Semen volume, sperm concentration, and sperm motility were measured in the semen tests, and LH, FSH, PRL, testosterone, and E2 were measured in the hormone tests. T/E2 was also added. Total motile sperm count (semen volume X sperm concentration X sperm motility rate) was calculated from the semen test results.

Based on the reference values for semen testing in the WHO laboratory manual for the examination and processing of human semen, 6th edition (2021), a total motile sperm count of 9.408 X 10⁶ (1.4 mL X 16 X 10⁶/mL X 42%) was defined as the lower limit of normal, assigning a value of "0" if the total motility sperm count for an individual patient was above 9.408 X 10⁶ and a value of "1" when it was below. The accuracy of the AI model was approximately 74%.

A New Model for Determining Risk of Male Infertility from Serum Hormone Levels, without Semen Analysis, Scientific Reports (2024).

Next, the AI model was validated using data from 2021 and 2022 for which both semen and hormone tests were available. Using the data of 188 patients in 2021, the accuracy was about 58%, while accuracy using the data for 166 patients in 2022 was about 68%. However, non-obstructive azoospermia could be predicted with a 100% accuracy rate in both 2021 and 2022.

Who needs males? Female sharks make babies alone

 Researchers have noted the first case of "virgin birth", or reproduction without fertilization, in an endangered shark species, a scientific journal reported this week.

The findings published in Scientific Reports concern the first case of the phenomenon in the common smooth-hound shark, Mustelus mustelus, a species threatened by illegal fishing that inhabits the Mediterranean and other warm waters.

Researchers found that two female M. mustelus sharks under observation in captivity had exhibited parthenogenesis—in which a female can reproduce asexually without the need of sperm to fertilize the egg—each year since 2020.

The two 18-year-old sharks have been at the Cala Gonone Aquarium in Sardinia since 2010.

Remarkably, this finding reveals that parthenogenesis can occur annually in these sharks, alternating between two females, and conclusively excludes long-term sperm storage as a cause.

Cycling parthenogenesis, in which progeny can be born either from fertilized eggs or asexually with unfertilized eggs, occurs in over 15,000 species, yet is not fully understood.

Parthenogenesis,  is more common in invertebrates than vertebrates. Reptiles and some sharks, rays and skates are able to "modify their adaptive strategy according to the surrounding circumstances".

Although the mechanisms driving parthenogenesis remain unclear, it is suggested that male population reduction could be a pivotal factor.

Giuseppe Esposito et al, First report of recurrent parthenogenesis as an adaptive reproductive strategy in the endangered common smooth-hound shark Mustelus mustelus, Scientific Reports (2024). DOI: 10.1038/s41598-024-67804-1