Some of Europe's earliest modern humans visited the Nerja Cave, which is open to the public. Image credit: Ana Vanesa Garcia Naranjo/Shutterstock.com

The Nerja Cave has been in use for over 40 millennia. Image credit: VLADJ55/Shutterstock.com

Based on these findings, the authors conclude that “Nerja Cave is the Palaeolithic Art cave in Europe where the greatest number of phases of distinct prehistoric visits to internal areas have been recorded.” Along with this discovery comes new insights regarding the various ancient human cultures to have conjured up a flame within the cave.

For instance, the oldest residues identified by the researchers coincide with the Aurignacian industry, which is associated with the earliest modern humans in Europe. It’s also possible that some of this soot was left by the torches of Neanderthals, thus providing new insights into our extinct cousins’ mastery of fire.

Further analyses revealed that a particular type of pine was used for the fires that lit the cave throughout prehistory, despite the availability of other wood sources in the nearby environment. This suggests that subsequent waves of human occupants all identified this particular tree as the best source of fuel for their torches.

Zooming in on a single stalagmite, the researchers detected soot from 64 separate incursions spanning the latter part of the Stone Age and the Copper Age, between 8,003 and 3,299 years ago. Based on their calculations, the authors say that the cave was visited once every 35 years throughout the Neolithic period.

While Nerja Cave continues to guard its many ancient secrets, these findings do at least help to tease out some of the details regarding the chronology of its use, as multiple generations of human visitors scrambled inside the cavern to create and observe art by the light of their pinewood torches. 

Describing the ambiance inside the cave during these visits, study author María Ángeles Medina-Alcaide explained that “the prehistoric paintings were viewed in the flickering light of the flames, which could give the figures a certain sense of movement and warmth.”

The study was published in the journal Scientific Reports.

Source

The results of a world-first clinical trial have shown promise for a new genetic therapy in reducing the amount of harmful proteins that build up in the brain of Alzheimer’s (AZ) patients, offering a tentative hope that the condition could be slowed or even reversed.

Using a the therapy on a small number of patients, researchers managed to halve the concentration of tau protein in their brains, which is thought to be implicated in the cognitive decline seen in people with AZ. 

Alzheimer’s disease is infamous in the research community as a contender for the most challenging disease to understand. Hampered by animal models that may not accurately represent it and numerous dead-end hypotheses that show promise in theory but fail in practise, research has continuously resulted in disappointment when it comes to creating a viable AZ treatment. 

Our best understanding of the underlying cause of AZ relies on two main mechanisms: the build-up of harmful tau tangles; and amyloid protein plaques. Both are proteins that go awry as they form, misfolding and joining together to stop brain cells from communicating with each other, and even causing neuron death. 

This research focused on tau. Tau is an insoluble protein that is encoded by the gene microtubule-associated protein tau (MAPT) and forms tangles in the brain of AZ patients, making it a prime target for therapies.  

The new approach, with the incredibly catchy name BIIB080 (/IONIS-MAPTRx), targets MAPT with a “gene-silencing” oligonucleotide (a short bit of DNA or RNA) that prevents the gene from creating more tau. 

As a Phase 1b trial, the clinical trials were designed to see if the drug is safe for humans and well-tolerated, not to see if it is effective at treating the disease – that comes later. The researchers tested it on 46 patients with an average age of 66, with some given the drug via injection into the spinal cord, while others got a placebo. 

All patients in the group completed the course and only minor side-effects were noted, indicating the treatment is safe. Upon completion of the trial, the researchers discovered a tau reduction of over 50 percent in the central nervous system of the group that received the highest dose after 24 weeks, suggesting the drug had a significant biological effect. 

The researchers now need to push towards further clinical trials over a longer period of time to evaluate if this effect actually impacts AZ symptoms. It is typically at the next stage that AZ drugs tend to fail, as translating these successes into symptom reduction is a difficult task – but this is one of the first promising results from such a therapy in a long time. 

“We will need further research to understand the extent to which the drug can slow progression of physical symptoms of disease and evaluate the drug in older and larger groups of people and in more diverse populations,” said Dr Catherine Mummery, lead author of the study, in a statement. 

“But the results are a significant step forward in demonstrating that we can successfully target tau with a gene silencing drug to slow – or possibly even reverse – Alzheimer’s disease, and other diseases caused by tau accumulation in the future.” 

The research was published in the journal CNS Neuroscience and Therapeutics. 

Source

Have you ever wondered how the Vikings managed to navigate from Scandinavia to America a millennium before the invention of GPS systems? The routes they took often crossed through near-polar regions that were subject to dense fog, rain, and clouded skies that obscured the Sun and stars, making it extremely difficult to find their bearings using these celestial markers. Well, an answer that has become popular in recent years is that they may have used a special crystal to find their way. But was this really the case?

Anyone who is familiar with the History Channel’s hit show Vikings will remember the scene where Ragnar Lothbrok explains to his brother a secret means of navigating the seas in cloudy conditions. He then procedures to produce a translucent crystal that he uses to enhance the Sun’s rays. This scene has popularized an idea that has been hotly debated among historians and scholars for decades and which has become a commonly held belief – the Vikings navigated the seas using Iceland spar. 

The Iceland spar, sometimes referred to as a sunstone, is a clear form of calcite (calcium carbonate, CaCO3) that is found in parts of Iceland and Scandinavia. The crystal exhibits a special property known as double refraction, or birefringence, which means it splits polarized light into two rays with different refraction indices and velocities. The result is that anything viewed through the crystal is doubled. Today, Iceland spar and similar crystals have various uses in precision optical instruments and LCD screens; Iceland spar was also an important mineral in World War II where it was used in the sighting equipment of bombardiers and gunners.

For navigation, so the idea goes, mariners such as the Vikings could use the crystals as natural Polaroid filters. When light enters the atmosphere, it is scattered and polarized. If you hold a crystal like a piece of Iceland spar towards the sky and rotate it, it is argued, the light passing through the crystal brightens and dims in relation to the polarized light in the atmosphere that centers on the Sun. The crystal’s double refraction is at its brightest when it is correctly aligned, thus indicating where the Sun is, even in cloudy conditions. If two readings are taken at different points in the sky, a navigator can identify the Sun’s direction and use that to calculate geographic north. 

It's a fascinating method of navigation that, some believe, is referenced in ancient Nordic sagas that mention mysterious “sunstones” that were used to find the Sun and set a ship's course. It was only in the late 1960s that the link to Iceland spar was made by a Danish archaeologist called Thorkild Ramskou. But do we have any solid evidence that the Vikings used this method and, moreover, does it even work? 

This is where things get cloudy. The current answer among researchers is a distinct “maybe” at best. The first challenge is that, to date, no sunstone has actually been found on a Viking ship or at a burial site. In 2013, French researchers from the University of Rennes say they found a chunk of Iceland spar on a British ship that sunk in the English Channel in 1592. Although the team did test it and speculated that it could have been used as a backup form of navigation to accompany imprecise compasses, there is no evidence that this was the case. Moreover, the find relates to a shipwreck that occurred centuries after the Vikings supposedly used this technique. 

Then there’s the challenge of whether or not this method of navigation is actually reliable. 

In 2016, a team of scientists set out to test this hypothesis. They simulated the conditions Viking explorers would have experienced on the seas and tested three types of crystal – calcite, cordierite, and tourmaline. They found that, in clear skies, all three crystals performed well. In slightly cloudy conditions, cordierite and tourmaline were better than calcite (only the purest calcite could compete with them), but in conditions where polarization was really low, calcite did better than the rest. All three crystals, however, were ineffective in overly cloudy and foggy conditions.  

Further tests are needed to assess this tool as a reliable means of navigation, but, as Stephen Harding pointed out in The Conversation “if the method does not work under cloudy conditions using the kind of imperfect crystals the Vikings would likely have had, then the theory is probably wrong. And on clear days it would have been easier just to use calibrated sundials”.

This does not mean the Vikings did not use sunstones to navigate the seas, but it seems the case for this particular method remains inconclusive. Besides, there's a good chance everything we thought we knew about Vikings is wrong. 

Source

Researchers have discovered a gene that they believe could be driving anxiety symptoms, potentially opening up a new therapeutic avenue. When the team modified the gene, they managed to reduce anxiety levels in animal models, suggesting the gene could be closely tied to the complex condition. 

Anxiety disorders are a set of complex conditions involving interactions between genetics and the environment, with trauma playing a critical role in their onset in many cases. Approximately one in four adults will be diagnosed with an anxiety disorder in their lifetime, but treatment remains extremely limited. 

Anti-anxiety medications exist, but they are limited in efficacy and less than half of the people that take them will achieve remission. This is largely due to how poorly scientists currently understand the brain circuitry that leads to these events, making understanding them the number one priority in combatting anxiety.  

To this end, researchers from the Universities of Bristol and Exeter looked to identify the underlying mechanisms behind anxiety symptoms by inducing stress in animal models and analyzing molecular events that may underpin them. They focused on a group of small molecules called microRNAs (miRNAs), which are also found in humans and bind to messenger RNA (mRNA) to stop them from producing proteins. Such miRNAs have been found to control proteins integral to processes in the amygdala, which regulates our emotions and has been implicated in anxiety disorders. 

Mice were subjected to stress and then immediately after the researchers took samples from their amygdalae for analysis. These were then compared to a control group to identify any differences during stressful events compared to standard brain activity. 

Immediately after stress, the team found a miRNA molecule called miR483-5p was increased, which they then demonstrated subsequently suppressed a gene called Pgap2. This gene is thought to drive anxiety-linked behaviors and miR483-5p acts as a stopper on this gene, regulating the amygdala’s stress response. Together, the team believes this pathway could be directly involved in anxiety symptoms. 

The team now want to further explore this pathway as a potential anxiety treatment option, hoping to fill a much-needed gap in treatment. 

“miRNAs are strategically poised to control complex neuropsychiatric conditions such as anxiety. But the molecular and cellular mechanisms they use to regulate stress resilience and susceptibility were until now, largely unknown. The miR483-5p/Pgap2 pathway we identified in this study, activation of which exerts anxiety-reducing effects, offers a huge potential for the development of anti-anxiety therapies for complex psychiatric conditions in humans,” said Dr Valentina Mosienko, one of the study’s lead authors, in a statement. 

The research is published in Nature Communications. 

Source

The question of why some galaxies have quasars at their core, and most do not, has finally been largely answered. The explanation indicates that in the far distant future, the Milky Way may host a quasar, with big implications for its development.

The discovery of immensely bright objects in the distant universe caused great consternation in the late 1950s and early 60s. Dubbed quasi-stellar objects, subsequently shortened to quasars, it quickly became clear that these enigmas were only around the size of the Solar System, yet could shine with the light of a trillion stars.

Eventually, astronomers concluded quasars gain their power from gas falling into supermassive black holes. However, most galaxies have supermassive black holes and only a few host quasars. The question of what causes the difference has now been answered in a new paper.

A team sought the answer by looking not at the quasars themselves, but the outer reaches of 48 relatively nearby host galaxies, which were compared to more than 100 non-quasar counterparts. They found distinctive distortions to the shape of two-thirds of the quasar galaxies, indicating they had recently experienced a close encounter, or full merger, with a massive counterpart.

The interactions with neighboring galaxies drive at least 0.2 solar masses of gas a year, which would otherwise orbit the supermassive black hole at a safe distance, into the maw for at least a million years, turning the quasars on. The phenomenon is temporary. Not only do the galaxies eventually run out of gas, but the energy released by the quasar drives more distant gas out of the galaxy entirely, ending star formation until restarted by some more modest neighborly interaction.

There are no known quasars within 600 million light-years of Earth, which once led them to be considered a phenomenon of the early universe that has now ceased. Certainly, it was easier for quasars to ignite when galaxies were young and most of their gas had yet to turn to stars. Nevertheless, quasars can still occur today under the right conditions, and one such case could be coming to our cosmic doorstep.

“Quasars are one of the most extreme phenomena in the universe, and what we see is likely to represent the future of our own Milky Way galaxy when it collides with the Andromeda galaxy in about five billion years,” study author Professor Clive Tadhunter of the University of Sheffield said in a statement.

Galactic mergers are common – the Milky Way has been through many on its path to becoming the giant it is today – but not all create quasars. Tadhunter and co-authors found similar outer reach distortions in a fifth of the non-quasar galaxies in their study, although they suspect many of these once had quasars that have since quenched.

Distinguishing what makes some, but not all, mergers quasar-forming may take some time. Nevertheless, the pattern the authors observed is too strong to be a coincidence.

One of the authors’ findings went against expectations. It had been thought quasars only ignite around the peak of galaxy mergers, and would be seen later once the shrouding gas and dust clears. However, the paper reports the majority of disturbed galaxies with quasars in their sample were still “in the pre-coalescence phase”, indicating enough gas is funneled to the center to cause ignition quite early in the process.

Moreover, the authors write; “We further emphasize that, while our results present strong evidence that galaxy interactions are the dominant trigger for type 2 quasars in the local universe, it is unlikely that they are the sole trigger.” Internal processes must account for the other cases and might be a bigger factor for more distant quasars.

The study is open access in the Monthly Notices of the Royal Astronomical Society

Source

More pandemics are coming, and the UK is woefully underprepared: that’s the stark warning from top scientists as the world continues to feel the impact of COVID-19. We’ve always known that it was not a one-off event, but there is a fear that lessons are not being learned and that the next pandemic could be even more devastating as a result.

Writing in The Independent, Professor Teresa Lambe – who helped develop the Oxford-AstraZeneca COVID-19 vaccine – warned that we are “sitting ducks” until more emphasis is placed on pandemic preparedness: “Building the infrastructure, investing in people and modifying policy to enable adequate pandemic preparedness is an insurance policy well worth the investment.”

Former chief scientific advisor to the UK government Sir David King was unequivocal in his view. He told The Independent, “We’re in the same position as we were in 2020. Nothing has changed... if anything it has got worse.”

Immunologist and geneticist Sir John Bell echoed these sentiments in a separate opinion piece. “Experiencing one pandemic does not reduce the threat of the next or mean that it couldn’t happen this year or next,” he wrote. “One thing is clear – despite everything we have learned, we are not ready for the next pandemic and have even seen cuts in our health security infrastructure.”

Recent polling suggests that these worries have filtered down to the British public too, with a YouGov survey finding that most Brits don’t feel the government is taking the threat of future pandemics seriously.

COVID-19 was the worst pandemic in living memory. As well as the devastating loss of life across the globe – particularly before the development of vaccines and more targeted treatment approaches – there are millions of people with long COVID, the full ramifications of which are yet to be unpicked. Beyond the health impacts of the virus itself, the broader societal effects of infection control measures like lockdowns, and the stress of living through such a turbulent time, will continue to be researched and debated.

But COVID-19 was not the first pandemic humanity has ever seen, and it certainly won’t be the last. The 1918 flu pandemic devastated a world emerging from the grip of warfare, and similar H1N1 strains of the influenza virus caused further (albeit less catastrophic) pandemics in 1977 and 2009. Under the right circumstances, animal diseases like Marburg virus disease and avian flu can “spill over” and spread throughout human populations. Even a The Last Of Us-style fungal pandemic is not beyond the realms of possibility.

Because of this ever-present risk, experts argue, humanity should learn lessons from COVID-19 and seek to avoid history repeating itself.

“What can we learn from COVID-19 and its early spread? How do early policy responses compare in different countries? And what were the reasons for the collective failure to fast-track access to life-saving technologies for the most vulnerable populations during this crisis?” asks Sir John Bell.

“We need to consider the worst-case pandemic scenarios and stimulate sustained political focus and investment from governments, global health organisations and industry into pandemic preparedness.”

It would be all too easy, he writes, to think of COVID-19 as over and done with – at least for those not still directly living with its ill effects. But in doing so, we risk a potentially avoidable catastrophe the next time around.

“The next pandemic could be even more devastating than the last. We must be in a constant state of readiness for the next big health crisis – if we do not act now, we will not be forgiven.” 

Source

More than 200 years ago, mysterious stone balls began to be unearthed in the UK. These oddly geometric stones date back to the Neolithic period, approximately 5,000 years ago. With the majority appearing in Aberdeen, Scotland, the now 500-strong collection has been found in Ireland, England, and even Norway.

Made from various types of stone including sandstone and granite, with one even being coated in a black fish-based paste, the balls in the collection all share remarkable similarities despite their relative geographical spread.

While their uniform size measures around 70 millimeters (2.75 inches) in diameter, with the exception of a larger collection measuring 114 millimeters (4.5 inches), the balls all display varying degrees of workmanship.

They all feature between three and 160 projectile knobs or disks, with six being the most common. Some of them feature distinctly decorative engravings of circles and swirls, while others are left blank. It’s believed the stones will have taken several years to carve, with some of the more intricate pieces even taking multiple generations.

One of the most intricate, well preserved, and well-known pieces is the Towie ball.

The Towie ball

Measuring approximately 73 millimeters (2.87 inches) and weighing 500 grams (17.6 ounces), the Towie ball gets its name from its place of discovery on the slopes of Glaschul Hill, Towie, Scotland.

Donated to the then-named National Museum of Antiquities of Scotland in 1860 on behalf of farmer James Kesson, the ball features four prominent disks, three of which are intricately carved and the fourth blank.

While the fourth blank disk has led many to believe the engravings on the ball are unfinished, there are theories surrounding the use of the Towie stone that suggest this was intentional and meant to be used as the ball’s base.

Rock art in Achnabreck, roughly 200 miles from Towie, features a cup in which a ball with the Towie ball’s properties fits. The engravings around the cup are thought to be part of a prehistoric sundial or lunisolar calendar, whereby pouring water or oil over the ball fills the rivets in the rock and reflects the sun and moon’s light.

The exact use of the Towie ball and all the other stones in the collection, however, is still widely speculated.

The Towie stone is now held at the National Museums Scotland, where they have created a 3D virtual model that enables viewers to see intricate details of the ball from anywhere in the world. The model is so detailed, in fact, that it has enabled researchers to notice intricate carvings that were not spotted under real-world observation. 

Artist's rendition of the Towie ball. Image credit: Unknown author via Wikimedia Commons (public domain)

Theories surrounding their use

As with the Towie ball, there are theories around the entire collection being a form of timekeeping for the people of the Neolithic. Acting as the equivalent of a modern wristwatch, their polished appearance may have been used as a form of portable spherical sundial.

Some theories also point to the religious beliefs that farming communities held at the time, focusing on times of the year like winter and summer solstice. This again points to their use as lunisolar and tidal calendars that may have helped communities detect seasonal changes.

The symbols engraved on some of the stones may have also related to the religious and ceremonial uses for the balls. With highly intricate and time-consuming construction, it’s thought the pieces would be considered very valuable and precious, and may have been used specifically for religious or spiritual ceremonial practices.

Similarly, the value these items held could have meant they were used as a status symbol, owned by the most wealthy and powerful members of the community.

There are, however, many theories that point to a more practical use of the stones. Some believe they may have been used as weighing scales for transactional purposes, which would explain their abundance.

Some suggest they may have been used in a form of ancient throwing game, or even shot from a sling as a form of blunt-force weaponry, although there’s no physical evidence on the stones that show the expected wear and tear these activities would undoubtably have.

Any assumptions of the use of these unusual stones will always be tentative, as the communities using them hadn’t yet learnt to write, meaning there’s no written record. The remarkably good conditions of all the stones in the collection, however, shows they were once cherished by their communities. 

Source

Magna’s new rearview mirror cleverly integrates a driver-monitoring system

An octopus’s stripes can act as a unique ID

Men ages 20 to 40 are the primary group diagnosed with testicular cancer. While highly treatable, early detection can affect outcomes.

"The majority of testicular cancers are actually painless," says Timothy Lyon, M.D., a Mayo Clinic urologist and oncologist. "Men should not be reassured if they're not having pain. If something feels abnormal, it still needs to be evaluated."

Start with monthly self-examinations to make sure there are no abnormal ridges, bumps or masses on either testicle. Risk factors include if a testicle did not fully descend at birth, or if there is family history or a previous personal history of testicular cancer.

"We are able to cure almost all men affected with testicular cancer, no matter what stage of disease they present with," Dr. Lyon says.

Treatment starts by removing the affected testicle, and may require chemotherapy, radiation or additional surgery.

Many patients ask whether they can still have children after testicular cancer.

"Many men, particularly those with early stage testicular cancer are able to preserve their fertility and not have any change in their likelihood of being able to father a child," Dr. Lyon says. "But, of course, every situation is different."

©2023 Mayo Clinic News Network. Visit newsnetwork.mayoclinic.org. Distributed by Tribune Content Agency, LLC.

Source

Owlstone Medical is developing a non-invasive, easy-to-use breath test that can be taken in primary care settings for the diagnosis of advanced non-alcoholic steatohepatitis (NASH)—a leading global cause of chronic liver disease. The technology is also being adapted to detect cancer.

In a new study, published recently in the Journal of Clinical and Translational Hepatology, a set of volatile organic compounds (VOCs) are identified that can determine patients with liver disease and separate them based on severity.

Exhaled breath contains more than 1,000 VOCs as well as microscopic aerosol particles, originating from the lungs and airways. According to Owlstone Medical, Breath Biopsy provides a new way to access these rich sources of biological information by collecting and analyzing breath samples.

The published paper is part of Owlstone Medical's PAN-study, carried out with Cambridge University Hospitals NHS Foundation Trust (CUH).

Samples were collected from 46 CUH patients with advanced liver disease and compared with 42 healthy patients to identify VOCs that differ significantly between the groups, and which appear to be driven by impairment of liver function. From this, a model with strong correlation to disease severity was generated that holds great promise for liver disease detection and monitoring.

Following further trials and development, it is hoped the breath test will be available in the next few years to help diagnose liver disease.

Around one in four adults develop non-alcoholic fatty liver disease (NAFLD) in their lifetimes, with approximately 20% of those progressing to NASH. Having a liver biopsy has long been the gold standard to test for liver disease, however it is costly, invasive, and can have serious complications, making it unsuitable for broad use in screening for disease.

The ultimate aim of creating non-invasive breath tests is to support early detection and precision medicine of diseases including cancer, asthma, chronic obstructive pulmonary disease (COPD) and liver disease.

Professor Rebecca Fitzgerald is one of the authors of the paper and Director of the Early Cancer Institute at the University of Cambridge.

She said, "We have been very pleased to work with Owlstone Medical to deliver this important trial—simple tests such as a breath test, which are easy and convenient for patients, could transform the way we diagnose disease, including cancer."

Billy Boyle is one of the original co-founders of Owlstone Inc, founded in 2004 as a spin-out from the Department of Engineering at the University of Cambridge. Owlstone Medical was spun out from Owlstone Inc in 2016 to develop and commercialize FAIMS in medical applications.

Billy began to focus on the medical applications of FAIMS technology after his wife Kate was diagnosed and later died of colon cancer as a result of a late diagnosis.

Commenting on the results of the study, he said, "Previously we demonstrated the potential of limonene as a biomarker for liver disease severity, however liver disease is complex, and comprehensive evaluation of liver function is not possible from a single biomarker.

"Now, following this additional excellent work by our internal team and external collaborators, we are pleased to be able to report this expanded set of VOCs, many of which are of exogenous origin and so may be suitable for development into Exogenous Volatile Organic Compound (EVOC) probes."

Source

Jean-Marie Robine is not impressed by your centenarian grandma. Sure, she’s sprightly for her age, but how unusual is making it to 100, really? Robine is a demographer and longevity researcher, and in his home country of France alone there are 30,000 centenarians; 30 times more than there were half a century ago. Add up all the centenarians worldwide and you get to 570,000—an entire Baltimore’s worth of extremely long-lived humans. Having a birthday cake with 100 candles is nice, but nowadays it’s nothing special.

To really pique Robine’s interest we need to up the longevity stakes a little. He is an expert in supercentenarians: people who live to 110 or even longer. In the 1990s Robine helped validate the age of the oldest person who ever lived. Born in 1875, Jeanne Calment lived through 20 French presidents before dying in 1997 at the age of 122, five months, and 15 days. Since then Robine has become a collector of the super long-lived, helping run one of the largest and most-detailed databases of extremely old people.

For Robine, each supercentenarian is a crucial datapoint in the quest to answer a big question: Is there an upper limit to the human lifespan? “There are still many things we don’t know. And we hate that,” says Robine. But there is an even more fundamental question that undercuts the whole field of longevity research. What if—in our quest to push the limits of human lifespan—we’re looking for answers in all the wrong places?

If you’ve ever read an interview with a supercentenarian, there is one question that will inevitably come up: What’s the secret? Well, take your pick. The secret is kindness. Not having children. Connecting with nature. Avoiding men. Or, being married. Smoking 30 cigarettes a day. Not smoking 30 cigarettes a day. Drinking whisky. Abstaining from alcohol altogether. We mine the lives of the super-old for hints on how we should live our own.

But this is the wrong way to approach the question, says Robine. His style is to step back, take a look at how many supercentenarians there have been, and figure out when they lived and died. The limits of human longevity won’t be found by looking at individuals, he believes, but by examining super-long-lived people collectively. It’s a statistical puzzle: to crack it, you need to know exactly how many people died at age 111, 112, 113, and so on, to work out the likelihood that a supercentenarian won’t make it to their next birthday.

In 1825, the British mathematician Benjamin Gompertz published one of the first attempts to calculate the limits of human longevity following this approach. Armed with birth and death records from Carlisle and Northampton, Gompertz calculated how someone’s risk of dying changed as they got older. Gompertz found that after a person hit their late twenties, their risk of dying in the subsequent year kept going up, year after year. But at age 92 something curious happened. Their annual chance of death leveled off at 25 percent per year. This finding was odd. It suggested to Gompertz that there was no upper limit to human aging. Theoretically, he mused, there was nothing in his data suggesting that humans couldn’t live for many, many, centuries—just like the lives of the patriarchs in the Bible.

But statistics is a cruel science, and Gompertz knew that too. According to his data, the risk of dying at age 92 was so high that you would need an unthinkably large number of humans to reach that age before you found just one person who lived to 192. Three trillion humans, to be precise—30 times more than have ever been born. And yet Gompertz found himself hampered by his dataset. So few humans made it past the age of 90 that it was hard for him to really know what mortality rates were like at very advanced ages. Did his results point toward some insurmountable limit to human lifespan, or just a temporary cap that could be lifted with advancements in medicine?

Modern demographers have picked up where Gompertz left off, sometimes with surprising results. In 2016 Jan Vijg and his colleagues at the Albert Einstein College of Medicine in New York concluded that mortality rates past the age of 100 start to rise rapidly, putting a cap on human lifespan of around 125 years. Two years later another group of demographers, this time led by Elisabetta Barbi at Sapienza University in Rome, came to the opposite conclusion. She argued that human death rates increase exponentially up until age 80, at which point they decelerate and then level-off after age 105. Barbi’s research raised the tantalizing prospect that there is no upper limit to human lifespan at all, just like Gompertz wondered.

If mortality rates really do plateau at a certain age, then extreme longevity is just a numbers game, Robine says. Say you had 10 people reach the age of 110, and the risk of any of them dying each subsequent year had plateaued at 50 percent. You’d expect five of them to reach the age of 111, two or three to reach 112, one or two of them to reach 113, just one to reach 114, and no one to make it to 115. To have a good shot of someone reaching 115, you need to double the number of people making it to age 110, and so on. In other words, the upper limit on lifespan is just a factor of how many people survived the previous year. But these numbers all hinge on exactly what and where the mortality plateau is. The problem is, the data available for calculating this isn’t very good.

The best global dataset on death is the Human Mortality Database, but it lumps everyone aged above 110 into one group. Then there’s the International Database on Longevity (IDL), a dataset that includes people living and dead who reached the age of 105 and beyond, which Robine helped set up in 2010. At its peak the IDL had data from 15 countries, but tightening data privacy regulations mean that more recent data coverage is patchy. Some countries have since partially withdrawn what they included.

Japan, for instance, has more centenarians per capita than anywhere in the world, but in 2007 its Ministry of Health, Labor, and Welfare reduced the amount of publicly-available data on its centenarians—meaning one of the richest sources of super-long-lived people is no longer producing useful information. And in countries that produce good data, the process of validating and tracking down birth records that can date back to the early 19th century is still laborious and frustrating. To validate Jeanne Calment’s age, Robine quizzed the supercentenarian about her early life, checking her answers against church records, censuses, and death certificates. Even so, the IDL contains records on just under 19,000 individuals, living and dead, from 13 countries. But for Robine, it’s vital to collect even more.

Robine’s friend Jay Olshansky, an epidemiologist at the University of Illinois at Chicago, has a different take on the matter. “Whether mortality rates plateau or whether they continue to rise is probably completely irrelevant,” says Olshansky. The sheer fact that it’s hard to generate reliable death rates past the age of 110 tells us everything we need to know about the upper limit on human longevity, he says—the fact there are so few supercentenarians tells us we’ve already reached the upper limit to human longevity. As the only person ever to live longer than 120, Jeanne Calment is simply a statistical outlier, Olshansky says. Other people might break her record by a few years, but it doesn’t mean that human lifespans are heading up, and up, and up.

In fact, Olshansky thinks that our obsession with ultra-long-lived humans is the wrong approach. “Studying these extremely long-lived people is like studying Usain Bolt when it comes to running and saying, ‘Yeah, we can all run that fast,’” he says. “To hold them up as what’s possible for everyone is naive.” On the contrary, Olshansky says that the quest for longevity in the developed world is mostly already over. We already live exceptionally long lives, he points out. In 1990 Olshansky wrote a paper arguing that eliminating all forms of cancer—which was responsible for 22 percent of US deaths at the time—would only add three years to the average US life expectancy. Once you get to a certain age, if one thing doesn’t kill you, then there’s something else around the corner that will.

Olshansky argues we should shift our attention to helping people live healthier lives, rather than simply focusing on overall lifespan. That’s a view shared by Juulia Jylhävä, a principal researcher at Karolinska Institutet in Sweden and a data scientist at MedEngine, a medical data science company based in Finland. “We should surely be more focused on healthspan and how to maintain not only health, but also functional abilities,” says Jylhävä.

Healthspan—years lived in good health—might be the unsexy cousin of longevity research, but figuring out ways for people to live healthier lives could have a much greater impact than extending lifespan by a few years. A big part of extending healthy lives is pinpointing when people start to decline in health, and what the early indicators of that decline might be. One way is by looking at frailty—a measure that usually takes into account factors like social isolation, mobility, and health conditions to produce an overall frailty score. In England, the National Health Service automatically calculates frailty scores for everyone aged 65 and over, with the aim to help people live independently for longer and avoid two major causes of hospital admissions for older people: falls and adverse responses to medication.

But Jylhävä’s research suggests that frailty indicators might be useful much earlier in life, too. She found that increased frailty scores were associated with higher mortality risks in old age, but that this association was particularly pronounced at age 50, where a jump in frailty score indicated a relatively large increase in mortality risk. Jylhävä says this is a sign that assessing frailty at age 65 is too late. Rather than looking to the ultra-old for the key to healthy aging, we should actually be looking at when and why younger people start the decline into ill health.

Of course, the lives of supercentenarians provide us some hints about what it takes to live a very long life. We know, for instance, that there are genetic drivers of longevity in both animals and humans. Earlier this year, a French nun named Lucille Randon died at the age of 118 and 340 days. Robine is looking at her genealogy to find out whether she—like Jeanne Calment—also had ancestors who lived exceptionally long lives. Find families of long-lived people, and more life-extending genes might reveal themselves. But even people with exceptionally good genes who make it all the way to 110 or more are still extreme statistical outliers. As the baby boomers reach their centenary around the middle of the 21st century, and the number of people in old age swells, we can expect the number of very old people in the developed world to shoot up. But such a trend is far from a guarantee that anyone will surpass Jeanne Calment’s 122 years.

Perhaps that’s the real secret of the supercentenarians—how much of their lifespan is really beyond our control. Even if more of us are blessed with good genes, healthy lifestyles, and excellent medical care, it doesn’t mean we should expect longevity records to come crashing down. Robine looks a lot younger than his 71 years, and he often gets asked what his secret is. “I know the secret because Jeanne Calment told me it,” he usually responds. But the truth is that Calment—unlike other supercentenarians—never shared her longevity tips with Robine. She had no secret at all.

The Quest for Longevity Is Already Over

(May require free registration to view)

Mysteries of the poisonous amphibians

Link between herpesviruses and giant viruses no longer missing

Has the “Tully monster” mystery finally been solved after 75 years?

Japanese lander appears to fail just before touchdown on the Moon [Updated]

Slowly and unsurely, humanity is weaning itself off coal. That's good because coal is the most carbon-intensive fossil fuel and a major driver of human-induced climate change.

But it's not good enough. According to a new study, humans are quitting coal too slowly to meet targets set under the Paris Agreement, the international treaty on climate change that aims to address global warming by curbing carbon dioxide emissions.

The goal of the Paris Agreement is to limit the rise in global average temperature to "well below 2 °C above pre-industrial levels," and to "pursue efforts" to keep the increase under 1.5 degrees.

Phasing out coal is a great way to do that since humans currently release about 15 billion tons of CO2 into the atmosphere every year, with coal accounting for about 40 percent of those emissions. Once it's up there, CO2 can linger for centuries, trapping solar heat and altering climates worldwide.

As part of their commitments under the Paris Agreement, many countries have plans to phase out coal, or at least use less of it. That's progress, and it's a giant leap from the state of international climate negotiations before the Paris Agreement was adopted in 2015.

Nonetheless, researchers say, we're moving in the right direction at the wrong speed.

At our current pace of phasing out coal, the authors of the new study report, we're on track to blow past the Paris Agreement's 2-degree limit for the maximum amount of global warming. Without big changes, they warn, we're headed for 2.5 or 3 degrees of warming.

This is not the first time researchers have come up with that prediction.

"More and more countries are promising that they will phase out coal from their energy systems, which is positive," says study co-author and environmental scientist Aleh Cherp from Lund University in Sweden.

"But unfortunately, their commitments are not strong enough," he adds. "If we are to have a realistic chance of meeting the 2-degree target, the phasing out of coal needs to happen faster, and countries that rely on other fossil fuels need to increase their transition rate."

To reach that conclusion, the researchers analyzed plans from 72 countries that have pledged to phase out coal by 2050.

The good news is it's still possible to avoid 2 degrees of warming. But only in the best-case scenarios, the researchers say, in which both China and India begin phasing out coal in five years.

Even then, they add, we would only stay below 2 degrees of warming if China and India adopt ambitious plans, at least matching the pace of the UK's reductions so far and exceeding the cuts Germany has pledged to make.

Under other scenarios, which the researchers call more realistic, Earth is on track for global warming of 2.5 to 3 degrees.

Dozens of countries have fallen behind on their Paris Agreement pledges, with a 2021 report finding Gambia is the only country currently on track.

Climate change is already wreaking havoc well before 2 degrees of warming, but scientists widely predict even worse consequences as we approach and pass that line.

This much warming is unprecedented in human history, but Earth has seen comparable warm periods long ago, offering us some clues about what to expect.

The loss of Antarctica's ice sheet could raise sea levels by 20 meters, for example, while people worldwide face incessant disasters ranging from heatwaves and megadroughts to superstorms and glacial floods, along with lower food security and higher risk of pathogenic disease.

Despite the rapid growth of renewable energy, and the increasing taboo of coal-fired power plants, coal is proving a difficult habit to kick.

Coal use is gradually declining in many countries, and after a 3.1 percent drop in 2020, global coal consumption increased by 1.2 percent in 2022, according to the International Energy Agency, pushing the world's yearly coal use beyond 8 billion metric tons for the first time.

Global CO2 emissions are also still increasing, rebounding from a pandemic-related low in 2020 to new highs in 2021 and 2022. CO2 emissions from coal rose 1.6 percent in 2022, according to the IEA, and coal remains the primary culprit behind rising CO2 emissions overall.

"The countries' commitments are not sufficient, not even among the most ambitious countries. In addition, Russia's invasion of Ukraine risks jeopardizing several of the countries' commitments", says Jessica Jewell, an environmental scientist at the Chalmers University of Technology.

Countries have long resisted quitting coal for economic reasons, since it's a cheap energy source. As climate change increasingly makes clear, however, coal is much costlier than it seems.

Reducing CO2 emissions will save lives and save money, and research has shown it will create jobs. Replacing coal may not be easy, but it is dramatically cheaper than the alternative.

The study was published in IOPscience.

Source

These character trait differences might have clinical implications for the doctor-patient relationship, suggest the researchers.

The selection and training of doctors may accentuate personality characteristics that differ from their patients, say the researchers, adding that in turn, these differences may create a mismatch between how doctors deliver information and how patients receive it.

The available body of research on doctors' personalities is dominated by convenience samples, low sample sizes and response rates; and limited by a focus on specific types of doctors, medical schools, or geographic areas, point out the researchers.

To avoid these issues, the researchers drew on two nationally representative Australian surveys, in which respondents were asked to assess their own personality traits.

The Household, Income and Labour Dynamics in Australia (HILDA) survey of 25,358 members of the general public aged 20-85 included 18,705 patients, 1,261 highly educated people, and 5,814 professional caregivers.

The Medicine in Australia: Balancing Employment and Life (MABEL) survey of 19,351 doctors included 5,844 general practitioners, 1,776 patient-oriented specialists, and 3,245 "technique-oriented" specialists.

The researchers wanted to find out whether there were personality trait differences between doctors and all the other groups, and whether there might be equivalent differences between the two groups of medical specialists.

They focused on the "big 5" personality traits of conscientiousness, agreeableness, extroversion, neuroticism, and openness as well as locus of control—belief in personal agency (internal) rather than external forces, such as fate, a higher power, or powerful others (external).

Agreeableness encapsulates empathy, kindness, cooperation, and warmth; conscientiousness includes the descriptors orderly, systematic, efficient, careful, and organized; extroverts are talkative, confident, loud, bold and lively; neurotics describe themselves as envious, moody, touchy, jealous, temperamental and fretful; while the descriptors philosophical, creative, intellectual, complex, and imaginative apply to openness.

Not unexpectedly, doctors were more agreeable and extroverted than all the other groups, but they were also more neurotic. And both doctors and caring professionals were more agreeable than patients. But doctors were significantly more agreeable than caring professionals.

Somewhat unexpectedly, doctors more strongly believed themselves subject to external forces beyond their control than the general public.

Although significant, this difference was relatively small, and there were no significant differences between doctors and patients, caring professionals, or the highly educated, caution the researchers.

Finally, differences among doctors across medical specialties were, overall, smaller than those between doctors and patients and the public, with family doctors (GPs) standing out for their higher level of agreeableness.

Women doctors seemed to differ more strongly from the other groups relative to men, the survey responses suggested. This was particularly noticeable for neuroticism, with women doctors scoring significantly higher on this trait than female members of the general public.

The researchers acknowledge certain limitations to their findings. Although based on well-known and validated instruments, the scales used to assess personality traits were self-rated. And the "big 5" descriptors differed slightly between the two surveys.

Nevertheless, the researchers suggest that these personality differences might have implications for the doctor-patient relationship and ultimately the success of treatment.

"For example, being more conscientious has implications for treatment adherence, as conscientious doctors may overestimate their patients' ability to follow recommendations. Higher doctor neuroticism, which is related to stress, could lead doctors to see stress as a normal part of life, and thus, underestimate the impact of [it] on patient well-being," they write.

"Doctor agreeableness and conscientiousness increase patient satisfaction with care, but could potentially lead doctors to view patients—in contrast to themselves—as more confrontational and less conscientious than patients actually are, causing an asymmetry in doctor and patient judgements of one another, which could impact outcomes," the researchers add.

"By taking into account these differences, doctors can better calibrate their judgments of patients and gain insight into factors that influence their patient interactions," they suggest.

A range of different personalities is also likely to be better for clinical team performance, they add, "The lack of personality difference we found between doctor specialties suggests that adding more doctors to a team will not increase diversity of personality-base perspectives. However, the differences found between doctors and those in other caring professions suggest that including non-doctor caring professionals in clinical teams will increase personality diversity, and thus, team performance."

Source

Researchers from the University of Houston, Texas A&M, and the Polytechnic of Milano set out to address the question at the heart of the matter: "Does knowledge work near deadlines incur higher sympathetic load than knowledge work away from deadlines?" Sympathetic activation is the state of physiological arousal that indicates how much people are "on the tips of their toes," and often leads to stress. This is why its intensity and duration should be kept in check, according to the researchers.

The first-of-its-kind study published in the Proceedings of the ACM Human Factors in Computing, was led by Ioannis Pavlidis, professor of computer science and director of the Affective and Data Computing Laboratory at UH.

Per an institutionally approved ethical protocol, 10 consenting researchers were monitored as they worked at the office in the two days leading to a critical deadline, and two other days without an impeding deadline. Miniature cameras were placed at the researchers' university office to unobtrusively record their facial physiology and expressions, as well as their movements throughout the working day. The participants' sympathetic activation was measured every second through quantification of their imaged perinasal perspiration levels.

Applying advanced data modeling on hundreds of hours of data recordings, the team found that researchers experience high sympathetic activation while working, which speaks to the challenging nature of the research profession. Surprisingly, this high sympathetic activation remains about the same with or without deadlines.

"Research is tough every day," said Pavlidis. "Using a metaphor, if you are under heavy rain all the time, if one day the rain is a little heavier, it would not make much difference to you because you are already wet to the bone. This is what our models show with respect to the effect of deadlines on researchers."

The only factors found to exacerbate sympathetic activation were extensive smartphone use and prolific reading/writing. The first factor is a manifestation of the gadget-based addiction trends that have altered human behaviors across the board. The second factor is integral to research work, and thus unavoidable.

Thankfully, however, researchers appear to auto-regulate increases in their sympathetic activation by instinctively adjusting the frequency of physical breaks. It was observed that on average, researchers take one physical break every two hours. From this baseline, data analysis showed that for every 50% increase in sympathetic activation, the break frequency nearly doubles, revealing the limits of cognitive work under increasing stress.

"Our naturalistic study not only brings fresh insights into researchers' behaviors but also challenges some prevailing views about deadlines", Pavlidis said. "With the recent advances in affective computing, I expect such naturalistic studies to proliferate across domains, challenging misconceptions we hold about a lot of things," added Pavlidis.

The study is published in the Extended Abstracts of the 2023 CHI Conference on Human Factors in Computing Systems.

Source

Despite Iran’s longstanding reputation for sustainable water management, the country currently faces mounting water-related challenges caused by population growth, industrial development, urban sprawl, lifestyle changes, climate change, territorial conflicts, poor management, and insufficient public participation. Since past and present water-related challenges share similar origins and patterns, addressing the past is imperative. After gathering, contextualizing, verifying, clustering, coding, and corroborating sources, we conducted a historical study to examine the relationship between water and Iranians from prehistoric times to the Islamic Golden Age (1219 AD). According to the findings, in prehistoric Iran, drought, flooding, river course changes, and the absence of a central government severely impacted water development. Despite doubts about the qanat’s origin, archaeological investigations indicate in the proto-historical period, qanat systems existed in Iran and the Arabian Peninsula. In 550 BC, the Achaemenids initiated a fundamental transformation in Iran’s water history by building dams, qanats, and water canals under a centralized administration. After a slump during the Seleucids (312–63 BC) and the Parthians (247 BC–224 AD), Iranians practiced water governance reborn under the Sassanids (224–651 AD). The Sassanids, like the Achaemenids, formed a powerful statement of unity, cooperation, and support among people for implementing their major water-related plans after enhancing institutions, laws, and communications. Chaotic Iran, however, endured severe water-related weaknesses in the Late Sassanids. Throughout the Islamic Golden Age, Iranians successfully traded water knowledge with other nations. As seen today in Iran, the Iranians have been unable to thrive on their resources since the Mongol invasion due to weak water governance, political tensions, and poor public support. The water sectors face more severe challenges when ancient water systems are ignored, applied without enhancement, or blindly adopted from other nations. Therefore, before current problems worsen, it is essential to integrate traditional and modern water cultures, technology, and management techniques.

If interested, please read the full paper at the source page.

Source

The US plans to build a successor to its unique USS Jimmy Carter spy submarine, bringing updated capabilities necessary for seabed warfare operations as tensions mount with China across various maritime theaters.

This month, Naval News reported that the US Navy would procure a one-off spy variant of the Virginia-class nuclear attack submarine, designated Modified Virginia, Subsea and Seabed Warfare (Mod VA SSW). 

The source notes that preliminary work by the Electric Boat shipyard in Groton, Connecticut, has begun with one Mod VA SSW to be procured in the US Navy’s 2024 budget at an estimated cost of US$5.1 billion.

While many details of the Mod VA SSW are classified, Naval News reports that the submarine can be expected to carry specialist uncrewed underwater vehicles (UUV), remote-operated vehicles and special operations submarines.

Asia Times has noted some of these assets, including the Orca Extra Large Unmanned Undersea Vehicle (XLUUV) and the MK11 SEAL Delivery Vehicle (SDV).

The Orca XLUUV can be deployed for surveillance and offensive seabed warfare operations such as minelaying, anti-submarine and special operations.

The MK 11 SDV can also stealthily transport SEAL teams to destroy China’s military installations in remote South China Sea islands, infiltrate enemy naval bases and sink hostile warships at port, or deploy SEAL teams in remote islands to perform surveillance or direct long-range precision fire from US and allied naval and air assets.

As with the USS Jimmy Carter, the Mod VA SSW may also be able to cut and tap undersea fiber optic communications cables.

Olga Khazan notes in a 2013 article for The Atlantic that the most accessible points for submarine cable tapping operations are at “regeneration points,” where signals are amplified and pushed further down the line. 

Khazan notes that fiber optic cables can be tapped more easily at these spots as they are laid out individually rather than being bundled together.

Undersea cables would be vulnerable to attack in any US-China conflict. Photo: US Navy / Joshua Knolla

Khazan writes that “intercept probes” could be deployed by agents at cable landing stations. These tiny devices capture light sent through the cables, copy it and turn it into data without disrupting Internet traffic. 

She also mentions that slightly bending the cables can allow enough light to leak out for data extraction, with the resulting disruption so indiscernible that it doesn’t register the cables are being tapped.

Bryan Clark notes in a 2015 report for the Center for Strategic and Budgetary Assessments that the expansion of undersea infrastructure including energy pipelines, undersea communication cables and civilian hydroacoustic sensors has made it imperative to take new forms of encroachment into account when planning for undersea warfare.

Clark writes these could include accidental detection by non-military sensors, protection of vital undersea infrastructure and opportunities to inflict damage on enemy undersea infrastructure during a conflict.

Seabed warfare presents unique operational challenges. In a December article last year, Naval Technology claimed that no country is currently well-equipped or prepared for the challenges of modern seabed warfare.

Naval Technology notes that seabed warfare has an element of plausible deniability, adding a hybrid dimension to offensive seabed warfare operations.

An attack against undersea internet cables can have devastating consequences. Bryan Clark notes in a 2016 article for the Bulletin of Atomic Scientists that the loss of communications caused by severed undersea internet cables can have disastrous consequences for time-sensitive diplomatic or military communications, cause massive financial losses as money transfers are disrupted and cripple other crucial systems as data is re-routed to other cables.

Clark elaborates on the further military consequences of such an attack, noting that an aggressor can sever multiple cables to cut off a defender’s military from its national leadership, intelligence and sensor information. 

These attacks can be highly destabilizing at the strategic nuclear level by potentially preventing a nuclear-armed opponent from controlling and monitoring its nuclear weapons and early warning systems, forcing the latter to keep its nuclear arsenal on heightened alert and increasing the chances of a pre-emptive nuclear strike.

Taiwan is at the center of these undersea warfare risks. Last November, Asia Times noted that Taiwan has 15 undersea internet cables connecting it to the outside world from three landing stations on its main island which China could attack in a conflict scenario, cutting the self-governing island’s access to external information.

Apart from Taiwan, the US Navy Fishhook Undersea Defense Line may be an inviting target for Chinese seabed warfare attacks. Asia Times noted this month that a network of hydrophones, sensors and strategically placed assets stretching from northern China running through Taiwan, the Philippines and Indonesia could monitor China’s nuclear ballistic missile submarines (SSBN), particularly if they attempted to break out into the Pacific and put the US mainland in range of their submarine-launched ballistic missiles (SLBM). 

Significantly, a Chinese seabed attack against that sensor network may be interpreted by the US as a prelude to a nuclear strike.

Crossed wires undersea could lead to nuclear war. Image: Handout

China may also be concerned about the vulnerability of its undersea communications cables. South China Morning Post (SCMP) reported in December 2021 that China built two bases to maintain undersea cables in the East and South China Seas, with the construction of the latter base in Hainan starting that year and planned to be operational by 2023.

SCMP also reported in March last year about China’s “Peace Cable” project. The undersea cable stretches for 15,000 kilometers connecting China, Europe and Africa, starting from Gwadar in Pakistan, passing through Kenya, Djibouti and Somalia, and ending in France with its second phase to expand to Singapore and South Africa.

Apart from the US, other major naval powers have developed specialized capabilities for seabed warfare. For example, Asia Times last July reported on Russia’s Belgorod submarine, which is designed to carry the Poseidon nuclear-armed underwater drone and the Losharik special mission submarine. 

Russia’s Losharik is an unarmed saboteur submarine reportedly capable of diving down to 6,000 meters and is purportedly Russia’s most silent and least detectable submarine.

It is designed to plant depth charges at inaccessible locations, conduct surveillance, tap underwater communication cables and perform submarine rescue and special operations.

Source

Microplastics can cross the blood-brain barrier and enter the brain after being ingested, a new study on mice reveals. The brains of mice fed micro- and nano-plastics (MNPs) were found to contain them just two hours after ingestion via a mechanism previously unknown to science, suggesting that the tiny plastics found almost everywhere could be even more worrying than previously thought. 

Once there, the researchers believe the MNPs could increase the risk of an array of serious diseases. “In the brain, plastic particles could increase the risk of inflammation, neurological disorders or even neurodegenerative diseases such as Alzheimer’s or Parkinson’s,” said Lukas Kenner, one of the lead researchers of the study, in a statement. 

Microplastics are everywhere. A sad reality of the use of plastics in almost every single aspect of daily life, microplastics and nanoplastics are being found in animals across the globe and have even been discovered in the human placenta, indicating that there may be nowhere left to hide from them. 

Such particles can enter the human body through drinking water from plastic bottles and food packaging, and it is estimated that 90,000 plastic particles can enter a single human drinking bottled water each year. 

Since their discovery, MNPs have become a growing health concern and have been implicated in a number of diseases. While previous research has shown how MNPs can move around the body, it was unclear whether they could gain access to the brain, with many foreign pathogens and particles failing to cross the blood-brain barrier. 

To that end, researchers used mouse models to observe how polystyrene MNPs of various sizes move throughout the body and how they could invade the brain, if at all. Taking six mice, the researchers administered the particles orally to three of them and then euthanized them two to four hours later, allowing them to take samples of the brain to test for MNPs. 

The team discovered that the smaller MNPs had crossed the blood-brain barrier and were present in the brain after just two hours. Some of the larger particles introduced into the mice didn’t make it through the barrier, indicating the particles were being aided by their tiny size – but the researchers wanted to look deeper into how exactly they were sneaking in. 

Using computer simulations, the team identified a passive transport mechanism into the brain that is helped by cholesterol molecules on the membrane surface, mapping a brand new MNP transport mechanism. 

The team now hopes their new transport model can help improve our understanding of MNPs and their implications on health for future research. 

“To minimise the potential harm of micro- and nanoplastic particles to humans and the environment, it is crucial to limit exposure and restrict their use while further research is carried out into the effects of MNPs,” Kenner explained. 

The research is published in the journal Nanomaterials. 

Source

Dark matter is a hypothetical substance that is expected to surround galaxies, outweighing regular matter five-to-one. It's invisible so the only way to see its effects is through gravity. Its existence was proposed to explain the weird rotation of galaxies and, assuming its existence, can explain a lot of what the universe is like – but its true nature has not been uncovered yet. However, a new paper argues "Einstein rings" indicate tell-tale signs that may give us a hint as to what dark matter is. 

If dark matter is indeed real, researchers strongly favor two versions. One is called WIMPs, or Weakly Interacting Massive Particles. These are particles that are tens or even hundreds of times more massive than a hydrogen atom. The other option sees dark matter made by axions. These particles are at the opposite end of the scale, being maybe 100,000 times lighter than a neutrino, a particle so light we don’t even know its mass for certain.

Attempts to find WIMPs and axions are very different but none have been fruitful yet. Researchers thought that by studying some peculiar gravitational effects, they might be able to gain some insights into one hypothetical particle over the other. And that’s where gravitational lensing comes in.

Any object with mass warps space-time. But those which are dense enough, create such a powerful warp that it can act like a lens. These massive objects can be individual stars, black holes, galaxies, or even clusters of galaxies. If another luminous object is located behind such a gravitational lens, its light gets distorted and magnified. If it creates large arcs, this is usually referred to as an Einstein ring.

This approach has been used to see objects further than any telescope would normally allow, like the most distant single-star system known. A research team led by astronomers at the University of Hong Kong wondered if would we see differences in the gravitational lenses if dark matter was made of WIMPS or axions. They suspected we would.

Quantum mechanics tells us that matter has a dual nature being both particles and waves. For something as light as axions, its wave nature becomes a dominant effect when it comes to gravitational lensing, while the opposite is true for WIMPs. The gravitational lens effect created by a dark matter made of axions is much closer to observations compared to the alternative.

In a specific case, in an image of the system HS 0810+2554, the image shows something truly peculiar. A distant quasar is quadruply lensed but it is visible in a triplet of images. Axions models can reproduce the various aspects of this system but WIMPs cannot.

“The ability of [wave dominated dark matter] to resolve lensing anomalies even in demanding cases such as HS 0810+2554, together with its success in reproducing other astrophysical observations, tilt the balance toward new physics invoking axions,” the authors conclude in the paper.

The research is published in Nature Astronomy.

Source