Category: English

Source: The Conversation – UK – By Stephen Brusatte, Chancellor’s Fellow in Vertebrate Palaeontology, University of Edinburgh

The following is an edited extract from The Story of Birds: A New History From Their Dinosaur Origins To the Present

I will never forget my first dinosaur wing. I was a college student, on my first international expedition, preparing to venture into the mountains of Tibet in search of Jurassic dinosaurs.

Our team assembled in Beijing, and as we rushed through the galleries and storehouses of the Institute of Vertebrate Paleontology and Paleoanthropology, I stole a fleeting glance, from across the room. A skeleton of the little carnivore Microraptor, its long arms unfurled, adorned with feathers forming a broad sheet. The wings sparkled in the low light; I was mesmerised. And then we were hustled along.

Nearly a decade later, I got to spend quality time with a dinosaur wing. My friend Junchang Lü, one of China’s leading dinosaur hunters, had gotten word that a farmer in Liaoning had stumbled upon something remarkable while harvesting his crops. It was a fossil coelurosaur (a variety of two-legged dinosaurs that includes modern birds), said to be swathed in many types of feathers. A few grainy photos confirmed those details, but little more.

A museum in the city of Jinzhou had procured the specimen and invited Junchang to study it. Because I had analysed many coelurosaurs for my PhD thesis, Junchang asked for my help. We met one cold November morning at Beijing’s central railway station and boarded an eastbound train. We didn’t know what would be waiting for us when we disembarked.

Two black SUVs, as it turned out. Junchang and I were whisked inside, and we sped through the streets of Jinzhou like we were in a presidential motorcade. When we arrived at the museum, we were led through a dim hallway and into a side room, where a big slab of gray rock balanced on a table. Everyone paused. A strange tension filled the air. After a few whispered words of Mandarin, Junchang turned to me and motioned us forward.

In front of us was a dinosaur skeleton the size of a large dog. It was obviously a dinosaur, as it had the reinforced pelvis, with extra connections between the backbone and hips, that all dinosaurs inherited from their Triassic ancestors.

Beyond that, I could tell it was a dromaeosaurid – a member of the same “raptor” group as Ostrom’s Deinonychus, Jurassic Park’s Velociraptor, and the Microraptor I’d seen years earlier in Beijing – because it had the signature sickle claws on its toes. And there were indeed feathers all over its body, which a couple of decades earlier would have seemed outlandish, but by now was no surprise to us.

What was astonishing, though, were its arms. Quite simply, the arms were wings. And the individual feathers composing the wings were preserved in sublime condition. We could clearly see a line of ten fan-shaped feathers attaching to the hand, each one longer than the humerus bone of the upper arm. Making a continuous series with them, another 20 feathers followed behind, affixed to the ulna, the bow-shaped long bone of the forearm that forms the wrist where it meets the hand, and the elbow joint at its back end.

Partially covering all of these feathers, close to where they attached to the arm bones, was a blanket of about 30 additional quills. These overlain feathers were smaller than the ones attaching to the hand and forearm, so they formed a dense covering close to the arm bones, but did not extend all the way across the wing.

This was the wing of a bird. Its overall construction was exactly that of a sparrow or an eagle. If I had just seen this wing and not the raptor dinosaur it was connected to, I would probably think that it belonged to some large bird.

The feathers attached to the hand are the primaries. They are the longest and narrowest of the wing feathers, can rotate individually relative to each other, and form much of the front and side of the wing when it is unfolded. The feathers attached to the ulna are the secondaries. They are more crowded together than the primaries, and therefore make a more coherent sheet, which forms much of the back edge of the wing.

The secondaries often join to the bone via ligaments, which attach to a series of bumps along the ulna called quill knobs. And finally, the feathers that covered the primaries and secondaries are the coverts. They help protect the primaries and secondaries, and give the wing extra integrity.

We named this winged raptor Zhenyuanlong: Mr. Zhenyuan’s dragon, in honour of the museum director who secured it from the farmer. Because its wing so closely matches that of a modern bird, and because today’s birds use their wings to fly, you would probably assume that Zhenyuanlong was soaring over the Cretaceous volcanoes of China.

But it didn’t. It couldn’t. It was not capable of doing that special thing that birds can do: actively flap its wings to generate enough of those two key aerial forces: lift to get airborne and thrust to move forward through the air. This is what is called powered flight, as opposed to passive aerial manoeuvres
such as gliding.

Zhenyuanlong’s body was too big, and its wings too small in proportion: if it tried to flap it wouldn’t have been able to stay airborne. That’s not a guess; it’s the laws of physics. There is a well-known relationship between body size and wing size in birds today that are capable of powered flight. They can have approximately 2.5 grams of body weight for every square centimetre of wing area and, at least theoretically, be able to support their body in the air. Any more weight, and flapping doesn’t work.

Zhenyuanlong was nowhere close to this cutoff; it would have needed to lose about half its weight in order for its wings to work as flappers. Other aspects of its skeleton corroborate this: its arms are quite short, and it lacks the large breastbone (sternum) that anchors the bulging flight muscles of today’s birds. Maybe Zhenyuanlong could have glided a short distance, but that would have been the extent of its aerial adventures.

Sexual selection

What we see in Zhenyuanlong is part of a wider trend. Many coelurosaurs had wings of quill feathers, but their wings were too small to power their bodies through the air. If you look at trends in feather evolution across the family tree of dinosaurs, the first species with wings were oviraptorosaurs like Caudipteryx and Big Mama, animals the size of sheep with wings no bigger than a dinner plate.

There is provocative evidence from fossil quill impressions on the ulna bones of even more primitive coelurosaurs that wings might have even first evolved in horse-
size dinosaurs. Those wings would likely have been about the size of laptop screens. There’s no way any of these dinosaurs could fly with such wings – at least in an active, flapping way.

This leads to a startling realisation: dinosaur wings did not evolve for flight. Like feathers themselves, wings evolved for another reason, and were later repurposed as airfoils. It’s a conundrum. Why else would such a large and complicated structure as a wing develop in the first place?

Looking at the too-tiny-to-flap wings of Zhenyuanlong got me thinking about a famous quote from Charles Darwin. “The sight of a … peacock’s tail, whenever I gaze at it, makes me sick!” he wrote to his botanist friend Asa Gray in April 1860, less than six months after he published On the Origin of Species.

Although Darwin was notoriously prone to stomach pains and other ailments, this particular ache was metaphorical. In the flamboyant train of the peacock – built
from huge feathers longer than the bird’s body – Darwin saw an outrageous structure whose origins he could not comprehend. It wasn’t used for flying, even though it was made of big feathers. It wasn’t helpful in finding food or escaping predators.

Try as he might, he could not envision it evolving through natural selection, the mechanism for change over time that he had just articulated in his new book, in which variations that confer advantages are favoured through survival of the fittest.

Perhaps, Darwin surmised, beautiful feathers and other gaudy structures develop not because they help their bearers survive the perils of droughts and predators, but because they promote reproduction. He called this theory “sexual selection”, to distinguish it from natural selection.

In 1871, in The Descent of Man, and Selection in Relation to Sex, Darwin explained how sexually selected traits like fanciful crests, feathers and colour patterns improve an individual’s ability to acquire mates, by making them either more attractive to potential partners or better able to compete with rivals in the mating game through displays of dominance and intimidation.

Might sexual selection explain why some coelurosaurs turned their simple fuzzy feathers into wings made of quills. It’s hard to prove definitively, but I think several lines of evidence support the case.

First is the fact that many modern birds like peacocks use their feathers – and even embellish them into comically large billboard-like structures – to attract mates and intimidate rivals. Second is the fact that sexual selection was operating in some of the first true birds flying overhead of their ground-bound coelurosaur cousins.

A primitive bird from China, called Confuciusornis, is known from hundreds of fossils, half of which have ridiculously long ribbon feathers streaming off their tails, and half of which don’t. These feathers are too skinny to provide any lift or thrust during flight, they’re seen in only half the population, and, crucially, they’re not present in those individuals that have medullary bone, the unique tissue that female birds use to mine calcium to shell their eggs.

Clearly these tawdry ribbon feathers are the stuff of males, and their only plausible use could be in display. Sexual selection, therefore, was happening in birds from the very beginning of powered flight, so it’s likely it was
shaping their coelurosaur ancestors too. The most convincing evidence, however, comes from the coelurosaur fossils themselves.

Dinosaurs in colour

Many of the dinosaur books I read as a child in the late 1980s and 1990s would include a defeatist statement: we’ll never know what colours dinosaurs were. Those books were wrong.

In the late 2000s a tall, bearded Danish PhD student named Jakob Vinther was looking at fossils under high-powered scanning electron microscopes and noticed a peculiar detail. Many of them – including dinosaur feathers – preserved
a variety of small, bubble-like structures. They looked exactly like the melanosomes of modern-day animals. These are the little vessels that hold pigment, the chemicals that confer colour. We know that sausage-shaped melanosomes impart a black hue, meatball-shaped ones a rusty red, and so on.

By measuring the size and shape of the fossil melanosomes, and comparing them to melanosomes in today’s animals, Jakob could predict the colours of dinosaur feathers. It was an astounding revelation.

Before long, Jakob and his colleagues showed that coelurosaurs boasted a brilliant array of plumage. Some feathers were black, others white, gray, or ginger. One little winged coelurosaur called Anchiornis was decked out in a fancy coat, as if going to a Jurassic cocktail party. Its face was speckled black and red, a ginger mohawk erupted from its head and neck, and its wing feathers were white across most of their lengths but black at their tips, which when the various primaries and secondaries and coverts were layered together, produced a wing of alternating white and black stripes, like the hide of a zebra.

Later Jakob got me in on the action, and trained one of my undergraduates, Angus Croudace, in deciphering the colours of another coelurosaur, a raptor called
Wulong, which had a drab grey body but black wings that sparkled in the sun with the iridescent sheen of a crow.

Such excessive flaunting of colour and texture could have served only one purpose: display. These coelurosaur ancestors and cousins of birds were under the spell of sexual selection, and some of the feathers forming the first dinosaur wings –
which were useless as flapping airfoils – were being used as ornaments.

Wings, therefore, might have first evolved in dinosaurs as advertising billboards sticking off of the arms. That was probably what many of these winged coelurosaurs, like Zhenyuanlong, were using their wings for.

Lift off

Then the billboards took on a new function, and became airfoils. It would have been pure happenstance. Remember that these coelurosaurs were getting smaller over time, and that there is also a tendency for display structures to become ever more fanciful in order to stay ahead in the mating race.

So while coelurosaurs like Zhenyuanlong were too big to fly with their small wings, you can imagine that if their bodies got a bit smaller, and their wings a bit bigger in order to look more attractive to mates or scary to rivals, a tipping point would be reached.

By the laws of physics, the billboards would now be broad enough, relative to the smaller size of the body, that if the coelurosaur moved them around, they could produce a little lift, a little thrust, and that dinosaur could start flickering about in the air.

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These first attempts at flight would have been awkward, and the billboard wings might have initially been used more as brakes or stabilisers, to help in leaping and turning. But now, a threshold had been crossed, and Darwin’s classic natural selection could start fine-tuning these flapping dinosaurs into ever-better aerialists.

It’s a story that makes intuitive sense. A nice, orderly progression from winged coelurosaurs to flying birds. But like many things in nature, the reality was probably much more complicated – and much more interesting.

The more feathered dinosaurs we find, the more we realise that not all coelurosaurs had the same types of wings. Some, like Zhenyuanlong, look similar to today’s birds, with wings on the arms made from layers of primaries, secondaries and coverts. But then there’s Microraptor – the little dromaeosaurid that hypnotised me as a college student in Beijing – which not only had wings on its arms but also on its legs, and its tail too.

In fact, such hind limb wings are present in many other feathered coelurosaurs, which is odd, because although various birds today have feathers on their legs, none has anything approaching a broad, sheetlike wing. And weirdest of all is tiny
Yi qi, a fluffy coelurosaur that would fit in the palm of your hand, which had feathers on its body but a wing made of something else entirely: skin, which stretched between its fingers and a strange rod-like bone in its wrist. It was a dinosaur that looked like a bat.

Some of these weirdly winged dinosaurs could surely glide, and a few probably were capable of powered flight. Microraptor is the prime example. My colleagues and I have done the calculations, and the wings of Microraptor were more than big enough to support its crow-size body in the air. On top of that, its feathers show many harbingers of flapping flight in modern birds.

Microraptor’s wing feathers are asymmetrical, with a much narrower leading vane in front of the shaft and a wider trailing vane. This is a telltale aerodynamic signal: It allows the overlapping feathers to form the cambered shape that a wing needs in order to function as an airfoil that can generate lift, the same way an airplane wing is curved at the top.

One stunning Microraptor fossil shows its wing feathers in mid-molt, and like flying birds today, it lost old feathers and grew new ones in a sequential pattern rather than all at once, probably so it could maintain enough of an airfoil to fly and not have to stay grounded for days at a time while it replenished its plumage. And finally, perhaps most convincing of all, scientists have built physical models of Microraptor, put them into wind tunnels, and observed how the wings are able to generate lift to keep the model airborne.

These various dinosaur wing shapes are indicative of distinct ways of gliding and flying, which, to me, implies multiple independent origins of flight among dinosaurs. We can understand it with an analogy to human aeronautics. A hot air balloon and a Boeing 737 can both get airborne, but they do so in much different ways, and look nothing alike.

No single engineer turned a hot air balloon into a Boeing 737; instead, they developed separately as different people, at different times, tinkered with ways to get into the air. But, those engineers had a common understanding of flight mechanics and properties like lift and thrust, so they built their flying machines out of the same general knowledge base.

Evolution seems to have done something similar with dinosaurs. There was a zone on the family tree of small coelurosaurs whose ancestors had already developed feathers for insulation, and elaborated them into wings for display.

Here and there, sexual selection and natural selection could make little tweaks to this common blueprint – a small decrease in body weight here, a slightly bigger advertising billboard wing there – and different coelurosaurs would be able to get
airborne. Each followed its own idiosyncratic route into the skies, some probably soaring upward from the ground and others parachuting downward from the trees, but they all emerged out of this frenzy of experimentation.

If you were back in the Jurassic or Cretaceous, trying to avoid the footfalls of a
Brontosaurus or the crushing bite of a T.rex, the skies would have been aflutter with a prehistoric aviary of gliding and flapping dinosaurs. It’s hard to know exactly how many coelurosaurs independently invented flight – it might have been just a few groups, it might have been dozens.

Some were probably short-lived; others might have persisted for millions of years, particularly those raptors with arm and leg wings. All bar one, however, met the same ultimate fate: extinction. That one survivor was the group that led to modern birds, which actively flap their arm wings made of primaries, secondaries and coverts.

It would be like if the entire history of human aeronautics – every hang glider, weather balloon, prop plane, crop duster, helicopter, rocket, jumbo jet – was wiped away, except for, say, space shuttles.

Copyright © 2026 by Stephen (Steve) Brusatte. Published by Mariner Books, an imprint of HarperCollins Publishers. No derivatives permitted. Reprinted with permission. The US edition publishes on April 28, while the UK edition publishes on June 11 and is available for pre-order.

To read an interview with Professor Steve Brusatte about the book, click here.

Stephen Brusatte publishes books with HarperCollins and Picador. He receives funding from the Swedish Research Council, European Research Council, National Geographic, and Leverhulme Trust.

– ref. The story of birds: a new history from their dinosaur origins – extract of Steve Brusatte’s new book – https://theconversation.com/the-story-of-birds-a-new-history-from-their-dinosaur-origins-extract-of-steve-brusattes-new-book-281562

Source: The Conversation – UK – By Samina Akhtar, PhD candidate in Population and Public Health and a Fogarty Fellow, Aga Khan University

For decades, one of the most prominent public health messages has been that smoking kills. But another everyday habit, far less dramatic and far more socially acceptable, may also be damaging our health: prolonged sitting.

Many people now spend up to ten hours a day seated at desks, in meetings or in front of screens. It may feel harmless, even unavoidable, but growing evidence suggests that too much sitting is linked to serious health risks, including cardiovascular disease, type 2 diabetes and early death.

People are often told to protect their health by exercising more and eating better. That advice matters, but it misses something important. Even those who meet recommended exercise targets may still face increased health risks if they spend most of the day sitting down.

This is because sedentary behaviour and physical inactivity are not the same thing. Physical inactivity means not doing enough moderate or vigorous exercise. Public health guidelines recommend at least 150 minutes of moderate activity a week, such as brisk walking or cycling, or 75 minutes of vigorous activity, such as running. Sedentary behaviour, by contrast, refers to long periods of sitting or reclining with very low energy expenditure, whether at a desk, in front of the television or during a long commute.

A person can therefore be physically active and still highly sedentary. Someone might go for a run before work, then remain seated for most of the next eight hours. The exercise helps, but it does not erase the effects of prolonged sitting on the body.

When the body stays still for long periods, a series of changes begins to take place. Skeletal muscle activity drops, making it harder for the body to absorb glucose from the blood. Over time, this contributes to insulin resistance, a major pathway to type 2 diabetes. Fat metabolism also slows down.

Blood flow becomes less efficient, reducing the delivery of oxygen and nutrients to tissues. This can impair vascular function and, over time, contribute to raised blood pressure.

Together, these metabolic and circulatory changes increase the risk of cardiometabolic problems, including high blood sugar, unhealthy cholesterol levels and the accumulation of abdominal fat.

Prolonged sitting also affects the musculoskeletal system. Poor posture and limited movement place strain on the neck, shoulders and lower back, helping to explain the aches and pains so common among office workers.

The effects are not only physical. Long periods of inactivity can reduce alertness, concentration and energy levels. Employees who sit for extended periods often report feeling more sluggish and less productive.

Globally, physical inactivity is estimated to contribute to around four to five million deaths each year. Much of the public health response has focused on encouraging people to exercise more, but reducing sedentary time is increasingly recognised as an important goal in its own right.

Since most adults spend a large share of their waking hours at work, the workplace is one of the most important settings for tackling the problem. Offices, universities and hospitals are not just places of productivity. They are also environments in which daily habits are shaped and reinforced.

Reducing sitting time does not require a gym membership or a dramatic office overhaul. Small, regular interruptions to sitting can make a meaningful difference.

Research suggests that standing up or moving for just two to five minutes every 30 to 60 minutes can improve glucose metabolism and reduce cardiometabolic risk.

Some organisations are already trying to build this into the working day. Walking meetings, prompts to stand or stretch and short movement breaks between tasks can all help people spend less time sitting.

Workplace design matters too. Height-adjustable desks allow employees to alternate between sitting and standing, while accessible staircases and walking routes can encourage more movement throughout the day.

A study of offices in the UK found that these kinds of measures can reduce daily sitting time by around one to one and a half hours. Employees also reported improvements in energy, focus and musculoskeletal comfort.

The message is straightforward: regular exercise is essential, but it does not fully offset the risks of sitting for too long. If smoking forced us to rethink the environments in which we worked and socialised, prolonged sitting should force us to rethink the structure of the working day itself. A short walk at lunch, standing during a phone call or simply getting up between meetings may sound like trivial adjustments. They are not. For modern workers, protecting health is not only about moving more before or after work. It is also about sitting less while work is happening.

Samina Akhtar has received funding from the Health Research Institute, National Institutes of Health, Islamabad, Pakistan. She is also a sub-recipient of a grant from the Fogarty International Center of the National Institutes of Health (USA) supporting her PhD research.

– ref. What sitting all day does to the body – https://theconversation.com/what-sitting-all-day-does-to-the-body-277444

Source: The Conversation – UK – By Ed Hutchinson, Professor, MRC-University of Glasgow Centre for Virus Research, University of Glasgow

The world is full of animal viruses, and we’re pretty sure that one of them will cause the next pandemic. To prevent pandemics, we need to predict which of the vast number of animal viruses are most likely to infect humans. A new study, published in Nature, sets out an elegant and powerful way for scientists to sift through the enormous diversity of animal viruses without risking being infected by them in the process.

In this study, a team of researchers in the UK used cutting-edge lab techniques to track down a previously obscure virus infecting bats in Kenya. Here’s what they did, and how they may have helped us to get ahead of the next pandemic.

Fortunately, most animal viruses will never cause pandemics because when they try to infect human cells, they fail at the first step.

To infect a cell, the first thing a virus has to do is to bind to an “entry receptor”. This is a specific molecule on the cell’s surface that the virus attaches to so it can enter the cell.

When a virus infects a new host species, it has a problem. The cells will be coated with different molecules from the ones the virus is used to, and often the virus has nothing to grab hold of. Viruses are adept at all the stages of cellular breaking and entering, but none of them matters if they can’t even get hold of the door handle.

If we could predict which viruses could use the entry receptors found on human cells, we would know which viruses we needed to take special care around to reduce the risk of pandemics. However, for most viruses, we don’t know what their entry receptors are, let alone if human cells carry them.

Finding the door handle

In this new study, the researchers set out on a hunt for viruses that could bind to human entry receptors. They chose the alphacoronavirus family. This group of viruses includes two common cold viruses, so clearly some of them can infect humans. They also include many viruses that infect other animals, particularly bats.

Alphacoronaviruses are distant cousins of the betacoronaviruses and hence of SARS-CoV-2, which famously jumped from bats to humans to cause the COVID pandemic. Could an alphacoronavirus do something similar?

The entry receptors of almost all alphacoronaviruses, like those of the vast majority of viruses, are not known. What we do have is the virus’s genome sequences. From these, the team identified the genes of the spike proteins. If you picture a virus, such as SARS-CoV-2, the spike proteins are the bits that stick out from the surface of the virus. Their job is to bind to entry receptors.

Not unreasonably, the scientists wanted to study viral receptor binding without spending any time in the presence of potentially dangerous pathogens. They did this by creating particles called “pseudotyped viruses”: dummy virus particles that carry the spike proteins of a real virus on their surface.

Pseudotyped viruses can bind to cells but cannot replicate. As a result, they are entirely safe to work with.

As expected, pseudotypes of the two common cold viruses grabbed firmly on to human cells. Comfortingly, most of the other alphacoronaviruses could not. But there was one exception. The coronavirus KY43, a rather obscure virus previously identified in heart-nosed bats in Kenya, bound very well to a protein found on human cells.

How worried should we be about KY43? Related viruses are found in bats around the world, but, fortunately, most of them are not very good at binding to the human version of their entry receptor. The ones that can bind to human proteins are found in a relatively small region of east Africa, and people living in the part of Kenya where the virus was first identified don’t seem to show any evidence of infection.

This is reassuring, though not surprising. There are multiple steps needed for a virus to break into a human cell, after all, and binding was just the first of them. But this work marks KY43 as a virus to keep an eye on.

More generally, this paper is a powerful proof of concept for how we could carry out pre-pandemic risk assessment. Screens like this can be safely applied to any virus that we have a genome sequence for. More broadly, it should be possible to design similar screens for many of the other things a virus needs to do in order to pose a threat to humans.

The world is overflowing with animal viruses, most of which will never hurt us. But some of them could. Work like this will help us spot the ones we need to take more care of.

Ed Hutchinson receives funding from the UK Medical Research Council and the Wellcome Trust. He is a board member of the European Scientific Working group on Influenza and chairs the virus division of the Microbiology Society.

– ref. Scientists have found a safer way to hunt for the next pandemic virus – https://theconversation.com/scientists-have-found-a-safer-way-to-hunt-for-the-next-pandemic-virus-281287

Source: The Conversation – UK – By Adam Brentnall, Reader in Biostatistics, Queen Mary University of London

Over the past decade, millions of men without symptoms of prostate cancer have voluntarily undergone a prostate-specific antigen (PSA) test in the UK to find out if they might have prostate cancer.

While research has shown that PSA screening in men aged 50-69 years can reduce cancer deaths, many countries hesitate to recommend or implement formal prostate cancer screening programmes that would offer PSA testing systematically and fairly to all men. The hesitation stems from concern about overdiagnosis and overtreatment.

But our latest research shows that prostate cancer overdiagnosis from PSA screening is mainly a risk for men over the age of 70.

Prostate cancer overdiagnosis occurs when a person is diagnosed with prostate cancer through PSA testing – even though that cancer would not otherwise have been diagnosed within the patient’s lifetime. So had the person not been tested, they might never have known they had prostate cancer.

Overdiagnosis from PSA testing occurs for two main reasons.

The first reason is because PSA tests might identify a cancer that is so slow growing it would never cause problems – even if the man lives to be 100 years old.

The second reason is because a PSA test is able to find prostate cancer a decade or more before it would cause symptoms. Some patients may die from other causes in that time. Had they not been screened, they might have died without ever knowing they had prostate cancer.

Prostate cancer overdiagnosis is a concern because of what follows diagnosis. Subsequent treatment, such as surgery, may lead to harm – including loss of ability to maintain an erection and urinary incontinence.

Had the cancer not been found through screening, the man would not have been treated and would have avoided the side-effects of treatment. Overdiagnosis affects quality of life – and results in costs both to patients and to the healthcare system.

To help men make an informed choice, our research looked at how risk of overdiagnosis changes with age at screening. We found that the risk of prostate cancer overdiagnosis from a PSA test is low in otherwise healthy men in their 50s and early 60s. But this risk sharply increases in men screened from age 70 onward.

First, we looked at long-term data from a large UK trial of more than 400,000 men to examine, over a 15-year period, what proportion of men developed prostate cancer – and whether that proportion differed between those who were screened and those who weren’t.

We found that, on average across all age groups, 12% of prostate cancers were so slow-growing that they would not have caused symptoms or been picked up by a doctor within 15 years of a PSA test. We also found that 88% of prostate cancers detected by PSA tests would, if not treated earlier, cause symptoms and be diagnosed within 15 years – provided the patient lived long enough and did not die of other causes.

We then used national data on men’s deaths in England to understand how many men die from causes other than prostate cancer after a PSA test. Risk of death from other causes within 15 years of a PSA test increases from 10% aged 50, to 49% aged 70 and 89% if aged 80. This steep rise in risk of death drives increased overdiagnosis with old age, because, naturally, the older you are the more likely you are to die from other causes.

Taking these findings together, we projected that there was a 16% chance that the average English man diagnosed with prostate cancer at age 50 from a PSA test would not otherwise have been clinically diagnosed within 15 years. This doubled to 32% for men diagnosed aged 70, and jumped to 58% for men diagnosed at age 80 years.

Essentially, as men age, they are more likely to die from other natural causes before prostate cancer would be detected. For men older than 70 years at screening, screening offers very little, if any, benefit, but carries a high risk of unnecessary harm from overdiagnosis.

It’s also worth noting that health is more than a number based on age. Overdiagnosis risk will be lower for men who are in generally in good health and follow a healthy lifestyle.

It’s important to point out as well that healthcare is evolving. Our findings are based on data from prostate cancer screening done in the UK between 2001 and 2007. Today, doctors use magnetic resonance imaging (MRI) for targeted prostate cancer biopsy in those with an elevated PSA test. This is expected to lower overdiagnosis compared with our estimates by filtering out slower-growing cancers. More significantly, the use of MRI substantially reduces the risk of overtreatment, so the harms of overdiagnosis are smaller than they were 15 years ago.

Two new trials are also evaluating whether such innovations can improve the benefits of screening without increasing the harms.

In the meantime, men without symptoms of prostate cancer who are concerned about their risk have to decide for themselves whether to request a PSA test. For now, our recommendation, as statisticians, is to consider your age before making a decision. But if you do have symptoms, regardless of your age, you should definitely see your GP.

Adam Brentnall receives funding outside this work from Prostate Cancer UK, NIHR, Breast Cancer Research Foundation, MRC, Cancer Research UK. He is a co-applicant on the TRANSFORM trial, and member of the UK National Screening Committee Research and Methodology Group, but this work is independent and not supported by or associated with either role.

Peter Sasieni is a lead investigator on the IMProVE trial, which is investigating whether prostate cancer screening can be improved by combining PSA testing with MRI scanning.

Rhian Gabe receives funding outside this work from Prostate Cancer UK, NIHR, Cancer Research UK and Yorkshire Cancer Research. She is a co-lead on the TRANSFORM trial but this work is independent and not supported by this role.

– ref. Prostate cancer overdiagnosis risk sharply rises after age 70 – new research – https://theconversation.com/prostate-cancer-overdiagnosis-risk-sharply-rises-after-age-70-new-research-281166

Source: The Conversation – UK – By Simon Kolstoe, Associate Professor of Bioethics, University of Portsmouth

The chief executive of the UK Biobank, one of the world’s largest biomedical databases, recently wrote to over 500,000 participants telling them that some of their data had been made available for sale online through a Chinese website. This wasn’t a data breach or hack, but rather researchers who had legitimately accessed the data trying to sell it.

Although it was stated that participants could not be identified, and there was no sign that the data had actually been bought by anyone, the fact that someone could even try to sell parts of the dataset is extremely concerning. Unfortunately, the failure was unlikely to be in the protection set up by the biobank itself, but rather in the honesty of the researchers accessing the data.

This raises the wider question of whether data – any data – can ever really be protected. Many databases, including the UK Biobank, operate secure research environments where restrictions are put on those accessing the information. This can be through secure computer portals or platforms (as used by the UK Biobank), or limiting researchers to only downloading the results of their analyses rather than the raw data itself.

But the problem is that once data exists, there is always a chance that it can be leaked through either accident or dishonesty. Legal restrictions, such as data protection laws, can give power to police or governments to try to stop this happening, or to subsequently prosecute. But in a world of international computer networks, and very different national views on privacy, even laws can only do so much. For instance, it has been claimed that data has been exposed accidentally from the UK Biobank 198 times before.

If this isn’t bad enough, the increasing availability of sophisticated AI tools means that even anonymised data can be de-anonymised. This is because AI tools are able to find complex patterns or links in data that no human would ever be able to discover.

So what is the answer? Do we revert to using pen, paper and filing cabinets, or do we need to keep evolving the way we think about our data and its security?

Harms v benefits

Possibly the main fear that people have with their data being made widely available is becoming the victim of fraud, bribery or perhaps a commercial organisation using it to make large profits or using it in other ways that we would not approve of. But the possibility of this depends on the type of data.

For instance, there are very clear reasons to keep data on personal finances, telephone records, or many other details about our personal lives confidential. However, when considering health data, including the types held in biobanks, does the potential for significant societal benefits change the way we think about risks and harms?

Medical confidentiality is considered a human right, certainly in Europe and the UK. This is because of the possibility of coercing or manipulating people if you have inside knowledge about their health. Doing this for nefarious gain is clearly wrong and must remain illegal.

Giving health data access to insurers or employers is less clear cut. While we all accept that their business practices mean that they do need to know a certain amount of information about us, many people feel uncomfortable with the idea of giving companies all of our healthcare information. This is where data protection laws come in that limit what and how commercial organisations use our data, albeit such laws require ongoing scrutiny as they are not always as effective as we may like.

However, looking beyond the individual, the real value of health data is at a group level. Humans are complex both biologically and psychologically, meaning that researchers need to look across a lot of people before patterns start to emerge. So how can this be balanced with personal privacy?

Veil of ignorance

The philosopher John Rawls proposed a thought experiment for considering issues of justice and society. His idea was to suggest people adopt a “veil of ignorance” by trying to forget their own personal position – including, race, gender, class, intelligence and health – when thinking about what might be best for society. So what would adopting a veil of ignorance mean when considering health data?

Aggregating health data is certainly not a new idea, and is the reason why organisations like UK Biobank exist, which to date has resulted in more than 18,000 research publications. So from the position of a veil of ignorance, the more data from the more individuals the better, as it does seem to lead to more research possibilities.

Second, research is very complex and now involves a wide range of disciplines, individuals and skills. Data from the UK Biobank has been used by 22,000 researchers in more than 60 countries. Again, from the veil of ignorance position, making data freely available to the widest range of researchers seems to be a good thing as the more people looking at it, in different ways, the higher the likelihood of discovering something useful.

Of course, safeguards do need to be in place to stop information being shared too widely, but these safeguards are becoming harder to implement as data processing software and AI is making it increasingly easy to identify individuals from otherwise “anonymous” data. Perhaps the issue is therefore focusing efforts less on controlling the availability of data, and instead increasing our focus on controlling how it is subsequently used.

This latest incident, alongside the wider context of daily cyber-attacks and leaks from other databases, seems to show that sooner or later most attempts at protecting data will fail. As a consequence, rather than trying to protect data, maybe we should start to accept that this type of data could now be considered a type of public good.

As with other public goods, the ethical obligation is to ensure how they are used. Yes, this may mean that commercial organisations, or even foreign governments, could use our data in ways we may not individually approve of, but disapproval of the actions of companies or other countries is hardly a new thing.

Political and international agreements regulate how all sorts of resources are used, and health data should now be included. Similarly, laws already exist to dictate what businesses can and can’t do with data.

It could be argued that if the potential benefits of fully open data sharing are truly enormous, and this incident among many others has shown we cannot protect such datasets, maybe we need to stop focusing on the futile task of trying to protect the data, and instead focus on working out how to ensure it is used in the right way.

Simon Kolstoe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. UK Biobank records listed for sale in China: why open data might be the answer – https://theconversation.com/uk-biobank-records-listed-for-sale-in-china-why-open-data-might-be-the-answer-281388

Source: The Conversation – UK – By Adam Taylor, Professor of Anatomy, Lancaster University

Collagen has become a staple of skincare advertising and social media wellness trends. But it is not just a buzzword.

It is the most abundant protein in the body and helps support structures throughout the body, including skin and bone.

For women, collagen loss can become especially noticeable during perimenopause and menopause. Some studies suggest that skin collagen may fall by as much as 30% in the first five years after menopause, with further losses of around 2% a year after that. On social media, this is sometimes called the “collagen cliff”, but the underlying idea is not new. Researchers have been writing about the effects of menopause on skin for decades, with papers from at least the 1940s pointing to the connection.

This sharper drop happens on top of the gradual changes that come with ageing. Collagen appears to decline over time, with some estimates suggesting a fall of around 1–1.5% a year from early adulthood.

Oestrogen helps regulate many processes in the body, including the production of collagen. In animal studies, oestrogen has been shown to increase collagen production and skin thickness. Human research has also found benefits for skin thickness, elasticity and wound healing.

This is partly because oestrogen acts on fibroblasts, the cells responsible for making collagen in the skin. When oestrogen levels fall during perimenopause and menopause, this signalling becomes weaker. The result is less collagen being produced, along with thinner skin, reduced elasticity and lower water content.

Collagen loss cannot be stopped entirely, but some factors can speed it up. One of the most important is ultraviolet radiation from the sun and tanning beds. This increases enzymes called matrix metalloproteinases, which act like the skin’s demolition crew, breaking down structural proteins such as collagen. These enzymes are found at higher levels in skin that has been damaged by the sun.

Ultraviolet radiation reduces the amount of new collagen that fibroblasts produce. People with darker skin tones tend to show less wrinkling, probably in part because higher melanin levels offer some protection against ultraviolet damage. But darker skin is not immune to photo-ageing, which means skin ageing caused by sun exposure.

Smoking appears to accelerate collagen loss. One study found that smoking reduced skin production of type I and type III collagen by 18% and 22% respectively, contributing to premature ageing of the skin.

Vitamin C is essential for collagen production. Around 100mg per day is enough for most adults, although smokers may need more. Many wellness supplements provide much larger doses, often around 1,000mg a day, but more is not necessarily better; around 2,000mg a day causes unpleasant gastrointestinal issues.

Products that claim to boost collagen are increasingly popular, but the evidence behind them is mixed. Topical collagen creams are unlikely to replace collagen lost from the skin because intact collagen molecules are too large to get through the skin barrier. They may help moisturise the outer layers of the skin, but they are unlikely to make a major difference to the skin’s own collagen levels.

Oral collagen supplements have been linked in some studies to improvements in skin hydration and elasticity. However, the scientific literature remains mixed. Reviews point to limitations in the evidence, including small study sizes, potential conflicts of interest and inconsistent findings, leading researchers to urge caution when interpreting the results. In the same way that collagen can’t be absorbed through the skin, the body has to digest it to absorb the amino acids that make collagen and there is no way to ensure the amino acids that made that collagen go to the skin or wherever you hoped it would. Hydrolysed collagen is better for absorption but there is still no guarantee that the body uses it where you want it to.

Hormone replacement therapy may offer more consistent benefits. As well as helping with other symptoms of menopause, HRT has been shown in some studies to improve skin thickness, elasticity and hydration. One study reported that women receiving HRT had a 48% increase in skin collagen content compared with untreated women, and other studies have reported similar trends. Some evidence suggests that transdermal (through-the-skin) oestrogen may also have measurable effects on skin collagen. But the overall risks and benefits of HRT always need to be considered on an individual basis.

Some dermatologists and cosmetic practitioners also use procedures designed to stimulate collagen production. Laser resurfacing treatments aim to trigger repair processes in the skin and remove damaged collagen. Newer versions of these treatments are designed to reduce side effects.

Microneedling is another commonly suggested option, although it is not risk free. Potential complications include pain, bruising, bleeding, infection, changes in skin colour, and in rare cases abnormal growths. It can also cause hyperpigmentation, which means patches of skin become darker than the surrounding area.

By the time menopause begins, collagen has usually already been declining for years. Protecting the skin from ultraviolet damage, avoiding smoking and getting enough vitamin C may help support the body’s natural collagen levels.

Menopause may speed up collagen loss, but the picture is more complex than social media slogans suggest. While collagen supplements remain popular, the science behind them is still developing. HRT has a clearer scientific basis for improving skin thickness, elasticity and hydration in some women, although it is not suitable for everyone. When it comes to collagen, the science is more helpful than the hype.

Adam Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Does menopause cause a ‘collagen cliff’? What you need to know – https://theconversation.com/does-menopause-cause-a-collagen-cliff-what-you-need-to-know-278127

Source: The Conversation – UK – By Anwen Elias, Reader in Politics, Aberystwyth University

Plaid Cymru’s electoral hopes for May’s Senedd election are high. Polls suggest the party is competing with Reform UK to emerge as the largest group in the next Welsh parliament, putting it, for the first time, within reach of leading a government in Wales.

This marks a striking shift in Plaid’s electoral fortunes. At the first election to what was then the National Assembly for Wales in 1999, the party won 28.4% of the vote. That remains its strongest performance to date in what was widely described at the time as a “quiet earthquake” in Welsh politics.

Since then, Plaid has struggled to match that breakthrough in devolved elections. From 2011 onwards it has consistently been the third-largest party in the Senedd, behind Welsh Labour – which has led every government since devolution – and the Conservatives.

Even so, the arithmetic of Welsh politics has occasionally worked in Plaid’s favour. The party entered government in coalition with Labour between 2007 and 2011, and more recently struck a co-operation agreement from 2021 to 2024. But if Plaid ends up leading a government outright after May 7, it would truly set this election apart.

Positioning itself for power

Plaid Cymru’s strategy is to present itself as a credible government-in-waiting. Its focus is less about being a party of protest and more about delivery. In other words, what it would do in office, how it would tackle Wales’s major policy challenges, and how it would represent Welsh interests at Westminster after nearly three decades of Labour dominance.

In February, the party set out its plan for its first 100 days in government. This focused on improving healthcare, raising education standards, boosting the economy and reforming government.

Alongside these priorities, its manifesto calls for further powers to be devolved to the Senedd. These include greater tax powers, justice and policing, rail services and infrastructure, and the Crown Estate, which oversees things like the sea bed and mineral rights in much of the countryside.

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Yet there has also been a noticeable change in tone on the party’s long-term constitutional aims. Our research examined how Plaid Cymru covered these issues in the 2021 Senedd election. Compared with five years ago, Welsh independence is significantly less prominent in both its current manifesto and campaign.

The timetable has softened too. There’s no longer a commitment to holding a referendum on independence in its first term of government. Instead, Plaid describes Wales as being “on a journey” to independence. It has committed to producing a policy on Welsh independence but with no referendum timeframe.

By downplaying its long-term constitutional ambitions in this way, and focusing on the more immediate policy challenges facing Wales, Plaid Cymru is approaching this Senedd election as many other pro-independence parties have done across Europe. A similar strategy helped the Scottish National Party win power in 2007 and remain in government for the next 19 years.

From polling strength to political power

Strong polling does not guarantee power, however, and Plaid faces several obstacles. Opponents continue to highlight its commitment to independence.

Support for independence among the Welsh public remains relatively low – only 26% of respondents in a recent YouGov poll agreed that Wales should be an independent country. Plaid’s challenge is to persuade sceptical voters that this isn’t the most important issue in Wales for the next four years.

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Voters in Wales face Senedd election amid confusion over who holds power over what

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The new electoral system also presents fresh uncertainties. This election will use a fully proportional model, with 96 members elected across 16 constituencies. Success will now depend on broad support across Wales. That’s a test for a party whose organisational strength has traditionally been concentrated in the north and west.

The new system is also likely to produce a more fragmented Senedd, with a wider range of parties represented. That could make post-election negotiations decisive, shaping who is able to lead a government and how stable it is.

Anwen Elias receives funding from the Economic and Social Research Council.

Elin Royles has received funding from the Economic and Social Research Council and the broader research underpinning this publication formed part of an EU Horizon2020 project

– ref. A new Welsh electoral landscape puts Plaid Cymru within reach of power – https://theconversation.com/a-new-welsh-electoral-landscape-puts-plaid-cymru-within-reach-of-power-279628