9-30-21 Coming off antidepressants risks relapse – but so does staying on them
People who stop taking antidepressants because they feel they no longer need them could trigger a relapse into depression, a study has shown. The findings may be taken by some as reason to continue taking such medicines indefinitely – but in fact the picture is more complex. In many high-income countries, the number of people taking antidepressants are at record levels, with an estimated one in 10 people using antidepressants in England. The medicines can cause side effects such as loss of sex drive and sleeping problems, and can be hard to stop taking. Some say that doctors are too willing to prescribe these drugs to people who might be better helped by psychological therapies or by changing their life circumstances, but people who feel they benefit from the medicines sometimes see such sentiments as “pill shaming”. The question has become mired in ideological debates over whether modern psychiatry has become overly focused on pharmaceuticals. There is also confusion over how the drugs work. Most antidepressants are a class of drug called selective serotonin reuptake inhibitors (SSRIs). For a long time, it was thought that people experiencing depression have low levels of the brain signalling chemical serotonin, which SSRIs restore. If that were so, it would make sense that some people would need antidepressants for life. But it now seems that this “chemical imbalance” theory of depression is wrong – and we still don’t know the real biological explanation for depression, or how SSRIs alleviate it in some cases. The latest study doesn’t answer that question, but it should provide some insights for people who are weighing their options when it comes to these medicines. It looked at 478 people in the UK on an antidepressant who were considering stopping taking the pills. About half were chosen at random to continue, while the rest were given placebo tablets instead of their usual pills.
9-30-21 First map of proteins in tumour cells pinpoints cancer therapy targets
The first ever map of how proteins interact in cancer highlights previously overlooked mutations that could be targeted for therapy. Trey Ideker at University of California, San Diego, and his colleagues devised a map which looked at how several dozen common cancer proteins interact in breast cancer and in head and neck cancer. “Cancer genes do not act alone,” says Ideker. “It’s just like the parts of any machine – they each affect each other.” Protein interaction maps involve cataloguing all the various ways proteins interact with each other in a biological system. In this case, the team picked 61 commonly mutated proteins in the two cancers and determined how they each interacted with each other and with the hundreds of other proteins in cancer tumours. “We are looking for communities of proteins that are under pressure to mutate during cancer,” says Ideker. For head and neck cancer, the team found 771 protein interactions involving around 650 proteins – and 84 per cent of the interactions had never been reported before. If these interactions are critical for tumour growth, future oncology drugs that target and disrupt them could slow the growth of cancers. Meanwhile, looking at the data overall, the team discovered a mutation to the protein collagen that had been overlooked by previous research. “This is the big advance of the study,” says Ideker. “There’s been anecdotes of finding cancer mutations this way before, but no one has systematically shown this.” Ideker hopes the method will be used in other cancers and that others will join in the quest to map even more protein interactions in cancer. Not only will this help find new drugs, he says, but it will also help scientists find new cancer biomarkers – which will help doctors devise more personalised treatments.
9-30-21 A blood test may help predict recovery from traumatic brain injury
High levels of a key blood protein point to brain shrinkage and damage to message-sending axons. Elevated blood levels of a specific protein may help scientists predict who has a better chance of bouncing back from a traumatic brain injury. The protein, called neurofilament light or NfL for short, lends structural support to axons, the tendrils that send messages between brain cells. Levels of NfL peak on average at 10 times the typical level 20 days after injury and stay above normal a year later, researchers report September 29 in Science Translational Medicine. The higher the peak NfL blood concentrations after injury, the tougher the recovery for people with TBI six and 12 months later, shows the study of 197 people treated at eight trauma centers across Europe for moderate to severe TBI. Brain scans of 146 participants revealed that their peak NfL concentrations predicted the extent of brain shrinkage after six months, and axon damage at six and 12 months after injury, neurologist Neil Graham of Imperial College London and his colleagues found. These researchers also had a unique opportunity to check that the blood biomarker, which gives indirect clues about the brain injury, actually measured what was happening in the brain. In 18 of the participants that needed brain surgery, researchers sampled the fluid surrounding injured neurons. NfL concentrations there correlated with NfL concentrations in the blood. “The work shows that a new ultrasensitive blood test can be used to accurately diagnose traumatic brain injury,” says Graham. “This blood test can predict quite precisely who’s going to make a good recovery and who’s going to have more difficulties.” Study participants were adults and mostly male, so more work needs to be done to determine if these findings apply to women, children and people with mild TBI.
9-30-21 A volcano-induced rainy period made Earth’s climate dinosaur-friendly
New evidence links ancient eruptions to climate changes that let dinos start a climb to dominance. The biggest beasts to walk the Earth had humble beginnings. The first dinosaurs were cat-sized, lurking in the shadows, just waiting for their moment. That moment came when four major pulses of volcanic activity changed the climate in a geologic blink of an eye, causing a 2-million-year-long rainy spell that coincided with dinos rising to dominance, a new study suggests. Clues found in sediments buried deep beneath an ancient lake basin in China link the volcanic eruptions with climate swings and environmental changes that created a globe-spanning hot and humid oasis in the middle of the hot and dry Triassic Period, researchers report in the Oct. 5 Proceedings of the National Academy of Sciences. During this geologically brief rainy period 234 million to 232 million years ago, called the Carnian Pluvial Episode, dinosaurs started evolving into the hulking and diverse creatures that would dominate the landscape for the next 166 million years. Previous research has noted the jump in global temperatures, humidity and rainfall during this time period, as well as a changeover in land and sea life. But these studies lacked detail on what caused these changes, says Jason Hilton, a paleobotanist at the University of Birmingham in England. So Hilton and his colleagues turned to a several-hundred-meter-long core of lake-bottom sediments drawn from the Jiyuan Basin for answers. The core contained four distinct layers of sediments that included volcanic ash that the team dated to between 234 million and 232 million years ago, matching the timing of the Carnian Pluvial Episode. Within those layers, the team also found mercury, a proxy for volcanic eruptions. “Mercury entered the lake from a mix of atmospheric pollution, volcanic ash and also being washed in from surrounding land that had elevated levels of mercury from volcanism,” Hilton says.
9-29-21 Gwen Adshead interview: Why ordinary people commit heinous crimes
Three decades spent working as a psychotherapist with the most violent offenders has convinced Gwen Adshead that they aren't the monsters we portray them as. HOW do people come to commit violent and life-threatening acts? Some think such people are innately bad, calling them “monsters” or “evil”. It is a view that William Shakespeare encapsulated in The Tempest when Prospero says of Caliban that he is “a born devil, on whose nature nurture can never stick”. But Gwen Adshead doesn’t accept that view. She has spent her career working as a psychotherapist with offenders in prisons and secure psychiatric hospitals, including Broadmoor Hospital, where some of the UK’s most notorious criminals are detained. Rather than seeing violent offenders as being innately evil, she thinks of her patients as survivors of a disaster – where they are the disaster and she is the first responder. Adshead has published many academic papers and books on criminal mental health. Now, in collaboration with the dramatist Eileen Horne, she has written her first book for a popular audience. It consists of a mosaic of case studies drawn from the many people she has treated over the years. In it, Adshead debunks myths about violent offenders, argues for compassion over condemnation and says that with good mental health care, recovery is possible. Rowan Hooper: You called your book The Devil You Know. Are you saying that we are all capable of evil deeds? Gwen Adshead: That’s very much where we’re coming from. I became interested in this while working as a therapist and listening to what people who’d done terrible things had to say. These offenders were familiar to me. They were not the “monsters” that I’d read about in the newspaper. They often seemed to be people who were sad and disorganised, and frightened as much as frightening. It is my very firm conviction that we all have the capacity to get into states of mind that we might call evil. It’s better that we understand those aspects of ourselves. In fact, the more we know about our own inner devils, the better able we are to act in ways that might help people and help ourselves. (Webmasters Comment: I don't agree! Exterminate them!)
9-29-21 Secrets of a long and healthy life reside in your gut microbiome
How long you live and how well you age rests on many factors beyond your control, but the discovery that gut microbes play a key role means what you eat can make a difference. WHY do we age? As youngsters, we seem invincible. We climb trees, frolic in the dirt and blithely share alarming quantities of mucus. At college, we can thrive on a diet of ramen and beer, party all night and still sit an exam the next day. But in our 30s, we start to wind down. It becomes harder to maintain muscle tone and avoid illness. Our joints start to ache and our memory begins to dim. And it is mostly downhill from there. People have long attempted to stop or reverse this process. But fountains of youth and secrets of immortality remain firmly in the realms of fiction. Our bodies wear out, even if we no longer do the back-breaking physical labour our ancestors did. And the world seems determined to grind us down with a plethora of disease-causing microbes. To help fend off these pathogens, our bodies recruit other microbes, vast numbers of which reside in our intestines, where we feed them in exchange for their services. But, as we age, this gut microbiota becomes less effective at fighting diseases too. This raises an intriguing possibility. Perhaps the secret of longevity lies not in the body itself, but in our gut microbes. We still have much to learn about this complex assemblage of bacteria, viruses, fungi and archaea, yet it turns out that people who achieve a healthy old age often have a distinctive gut flora. What’s more, we are finding ways to manipulate this world inside us. As strange as it seems, there is gathering evidence that we can increase our lifespan by changing our gut microbes. Even before you were born, your gut microbiome – the collection of genes that comprise the microbiota – was developing. The uterus was assumed to be a sterile environment, but recent research suggests it contains bacteria and fungi, which are ingested by the growing fetus. At birth, a baby is gifted more gut microbes if it passes through the birth canal. Other early colonisers come from the environment and especially the diet. In another surprising discovery, researchers have found that breast milk also contains a microbiome of its own.
9-29-21 Scientists have finally worked out the effects of consuming red wine
Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more. There is science that changes the world, and there is science that just makes the world a better place. Feedback would put a recent paper in PLoS One, “The power of Dionysus—Effects of red wine on consciousness in a naturalistic setting”, in this second category. Rui Miguel Costa and his colleagues at the Institute of Applied Psychology in Lisbon got participants either singly, in a duo or as a group of six to consume two glasses of Quinta da Lapa Reserva Syrah 2018, “a silky full-bodied red wine from the Lisbon region with 14° of alcohol”, in a Lisbon wine bar. They were then asked to fill in a questionnaire probing changes in their state of consciousness. Apologies to the sun-deprived for whom the word “Lisbon” may have appeared one or three too many times in that paragraph. We make no such apology for reporting the study’s results in detail. “Red wine increased pleasure and arousal, decreased the awareness of time, slowed the subjective passage of time, increased the attentional focus on the present moment, decreased body awareness, slowed thought speed, turned imagination more vivid, and made the environment become more fascinating,” the researchers found. “Red wine increased insightfulness and originality of thoughts, increased sensations of oneness with the environment, spiritual feelings, all-encompassing love, and profound peace. All changes in consciousness occurred regardless of volunteers drinking alone, in dyad or in group.” “Does that mean red wine mystically gives you the effects of being drunk?” a colleague asks, possibly sardonically. We aren’t sure, as we are on deadline, and we have been doing what it takes to increase our attentional focus on the present moment.
9-29-21 The stem cell revolution isn't what you think it is
AT THE turn of the 21st century, stem cells – the master builders of the body – took hold of our collective imagination. We began to dream of their marvellous healing powers. The era of “regenerative medicine” seemed to be dawning. Soon, we would be using stem cells to repair and replace damaged hearts, joints, spinal cords, kidneys, livers, windpipes, eyes and more. You name it, stem cells would fix it. More than 20 years have passed and we are still waiting. Despite the great promise of stem cell research and the hard work of scientists worldwide, the dream of regenerative medicine remains just that – a dream. If this sounds surprising, perhaps it is because you have heard about stem cell clinics offering treatments directly to consumers for all kinds of conditions: AIDS, Alzheimer’s, arthritis and even covid-19. However, these are unproven therapies. Rigorous clinical trials haven’t generally established their effectiveness, and there are still safety concerns. Yet business is booming for those selling unproven stem cell treatments, with a global turnover of an estimated $2.4 billion annually. In their hands, stem cells become snake oil, and stem cell research a pseudoscience. So far, there is only one tried-and-true stem cell therapy available: bone marrow transplantation and its variants, all of which involve the use of blood stem cells to restore someone’s blood-making capacities. Pioneered in the 1950s by researchers like Don Thomas (who won a Nobel prize for his efforts), this method has been routinely used since the 1980s to treat conditions like leukaemia. Over 1.5 million blood stem cell transplants have been performed globally, with most recipients seeing significant benefits in the length and quality of their lives. Bone marrow transplantation is certainly a form of regenerative medicine. However, it was developed long before stem cell fever took hold. The dream of regenerative medicine hinges on stem cells working other wonders. Over the years, hundreds of thousands of scientific articles have explored this possibility, but without much success.
6 9-29-21 Should you get a covid vaccine booster shot if you're offered one?
OVER the next few months, about 30 million fully vaccinated people in the UK will be invited to have a third dose of a covid-19 vaccine. The surprise decision to run such a large booster campaign – everyone over 50 is included – was made off the back of multiple lines of evidence, none of them definitive. So what is the rationale behind it? And if you are offered a booster, should you take it? The UK isn’t the only country looking to roll out third doses for a large portion of the population. Last week, the US Centers for Disease Control and Prevention endorsed the use of booster shots for people aged 65 and over, and for those with underlying health conditions or in jobs with a high risk of exposure to the virus. The UK government’s decision was based on advice from the Joint Committee on Vaccination and Immunisation (JCVI), which says the move is “precautionary”. The JCVI itself was largely guided by an ongoing clinical trial called COV-Boost, based at the University Hospital Southampton NHS Foundation Trust, UK. In June, COV-Boost recruited 2833 people aged 30 and over who were already double vaccinated with either the Pfizer/BioNTech or Oxford/AstraZeneca vaccines. They all received a third dose of one of seven covid-19 vaccines – Pfizer/BioNTech, Oxford/AstraZeneca, Moderna, Novavax, Valneva, Janssen and Curevac – or a control, a vaccine against meningitis. Half of the recruits were over 70 and a “decent number” of those were over 80, says chief investigator Saul Faust. Half had received Pfizer/BioNTech for their first two doses and half Oxford/AstraZeneca. Over the next four weeks, the volunteers kept a record of any side effects and on day 28 came in for a blood test to measure their antibody levels, T-cell responses and also a “killing assay” to see how potent their blood was at neutralising the virus. According to Faust, some of the vaccines produced “several-fold” increases in antibody levels and also improved T-cell responses, suggesting that they significantly strengthen protection against the virus. The vaccines were well tolerated in the small number of people in the trial.
9-29-21 Vitamin A treatment trial for Covid loss of smell
Vitamin A nasal drops might be able to treat the loss or altered sense of smell in some people who have had Covid, UK researchers say. The University of East Anglia is conducting a 12-week trial. Only some of the volunteer patients will receive the treatment but all will be asked to sniff powerful odours such as rotten eggs and roses. And brain scans will check if the vitamin has repaired injured olfactory pathways or "smell nerves". Loss or altered sense of smell is a common symptom of Covid, although many other viruses, such as flu, can also cause it. And while most people naturally regain it within a couple of weeks, many have been left with continuing smell disorders. Lina Alnadi, 29, from London, developed parosmia after Covid, which means the odour of many common things has changed for her. Tap water, for example, smells horrendous, the odour you or I might get from a swamp or sewer. The herb coriander has the whiff of deodorant. And eggs - one of Lina's favourite foods - smell like burnt rubber. "You take your sense of smell for granted," she says. "Losing it was devastating. It affected my diet dramatically. "There were lots of foods I just couldn't face eating. It was really upsetting." Simple things such as showering or brushing her teeth are also unpleasant because of her skewed sense of smell. But the situation has improved gradually and Lina has found a few life hacks that help. "Adding lemon or chilli to foods can make them smell better," she says. "I also experimented and made lists of safe foods that would not make me want to vomit. "I had to be creative about it to make sure I was eating enough of the right things to stay well." Lead researcher Prof Carl Philpott, from UEA's Norwich Medical School and James Paget University Hospitals NHS Trust, said: "We want to find out whether there is an increase in the size and activity of damaged smell pathways in patients' brains when they are treated with vitamin-A nasal drops. "We will look for changes in the size of the olfactory bulb - an area above the nose where the smell nerves join together and connect to the brain. "We will also look at activity in areas of the brain linked to recognising smells."
9-29-21 All identical twins may share a common set of chemical markers on their DNA
Testing for the marks could reveal if someone was conceived as an identical twin. Identical siblings are used to sharing a lot with their twin, including their DNA. But new research suggests all identical twins share a common signature of twinhood, not in their DNA, but on it. This signature is part of the epigenome, chemical markers that dot many spots along DNA and influence the activity of genes without altering their sequence. Identical twins everywhere largely share a specific set of these marks that persists from birth to adulthood, researchers report September 28 in Nature Communications. These shared epigenetic tags could be used to identify people who were conceived as identical twins but lost their sibling in the womb or were separated at birth. “This paper is absolutely fascinating,” says Nancy Segal, a developmental psychologist at California State University, Fullerton who has researched twins but wasn’t involved in the study. The research sets the groundwork for scientists to better understand “what might cause a fertilized egg to split and form monozygotic [identical] twins,” she says. Despite humans’ age-old fascination with identical twins, the biological process that generates them, known as monozygotic twinning, “is an enigma,” says Jenny van Dongen, an epigeneticist at Vrije Universiteit Amsterdam. Researchers know that identical twins form after a fertilized egg, called a zygote, somehow splits into two embryos during development. But why this cleavage happens remains unknown, van Dongen says. For the most part, identical twins don’t run in families, and they occur at roughly the same rate worldwide — about 3 to 4 per 1,000 births. With no clear genetic or environmental cause, the prevailing hypothesis is that identical twins arise at random, she says. Early development, for twins and non-twins alike, happens amid a flurry of epigenetic changes that turn many genes on or off as an embryo takes shape. Some of these changes may account for slight differences between identical twins (SN: 7/17/12). So to better understand what makes a zygote split to form identical twins, “it makes sense to look at epigenetics,” van Dongen says.
9-29-21 'Hell heron' dinosaur is new species found on Isle of Wight
Two new species of dinosaur that may have once roamed what is now the Isle of Wight in the UK 125 million years ago are thought to have been 9 metres long – about the same length as a Stegosaurus – with skulls like crocodiles. One has been described as a “hell heron”, with scientists likening its hunting style to a fearsome version of the modern-day bird. A haul of bones was discovered on the beach near Brighstone on the isle over a period of several years, and researchers now say they relate to two new species of spinosaurid, a group of predatory theropod dinosaurs closely related to the giant Spinosaurus. In all, more than 50 bones from the site have been uncovered from rocks that form part of the Wessex Formation, laid down more than 125 million years ago during the Early Cretaceous period. Neil J. Gostling at the University of Southampton, UK, who supervised the project, said: “This work has brought together universities, the Dinosaur Isle museum and the public to reveal these amazing dinosaurs and the incredibly diverse ecology of the south coast of England 125 million years ago.” The only spinosaurid skeleton previously unearthed in the UK belonged to Baryonyx, which was initially discovered in 1983 in a quarry in Surrey. Most other finds since have been restricted to isolated teeth and single bones. Analysis of the Isle of Wight bones suggested they belonged to previously unknown species of dinosaurs. Team member Chris Barker, also at the University of Southampton, said: “We found the skulls to differ not only from Baryonyx, but also one another, suggesting the UK housed a greater diversity of spinosaurids than previously thought.” The first specimen has been named Ceratosuchops inferodios, which translates as the “horned, crocodile-faced hell heron”.
9-29-21 New species of dinosaur unearthed by Isle of Wight fossil hunters
The discovery of two new species of dinosaur, which likely roamed the south of England 125 million years ago, has shed new light on the predators. Palaeontologists have described one of the carnivorous reptiles as a "hell heron", comparing its hunting style to a fearsome version of the bird. The remains of the three-toed dinosaurs were found on an Isle of Wight beach. They belonged to the spinosaurid group and are thought to have been 9m (29ft) in length with 1m-long (3ft) skulls. The collection of about 50 bones took several years to unearth. The first specimen - named Ceratosuchops inferodios - has been labelled a "horned crocodile-faced hell heron". With low horns and bumps around the brow region, the name also refers to the predator's heron-like hunting style. The second has been called Riparovenator milnerae, which translates as "Milner's riverbank hunter", in honour of British palaeontologist Angela Milner, who died recently. Fossil collectors initially found parts of two skulls before a team from the island's Dinosaur Isle Museum uncovered a large section of a tail. It comes after the last spinosaurid skeleton, which belonged to Baryonyx, was discovered in a quarry in Surrey in 1983. Only single bones and isolated teeth had been found since. PhD student Chris Barker, author of the University of Southampton study, said: "We found the skulls to differ not only from Baryonyx, but also from one another, suggesting the UK housed a greater diversity of spinosaurids than previously thought." Co-author Darren Naish, an expert in British theropod dinosaurs, said: "We've known for a couple of decades now that Baryonyx-like dinosaurs awaited discovery on the Isle of Wight, but finding the remains of two such animals in close succession was a huge surprise." The study also suggested how spinosaurids might have first evolved in Europe, before dispersing into Asia, Africa and South America.
9-28-21 DNA markers reveal if you shared a womb with twin that didn't survive
About one in eight people had a twin embryo that didn’t survive to term, and in future there may be a simple cheek swab test that can reveal if you are in this group. Jenny van Dongen at VU Amsterdam in the Netherlands and her colleagues have found that identical twins carry a characteristic pattern of alterations to their DNA, known as epigenetic changes, that isn’t seen in people who didn’t have twin embryos. These variations happen in early pregnancy and last into adulthood. Epigenetic changes are chemical modifications of DNA that help keep genes turned on or off. In early pregnancy, embryos undergo swathes of such alterations to programme different cells to become the various parts of the body. Van Dongen wondered if this process would work differently in multiple pregnancies. About one in 100 births globally are of twins, but studies have suggested that 12 per cent of people could have had a twin embryo at some point during pregnancy that didn’t survive. Although this may be referred to as vanishing twin syndrome, there can be visible remains. The researchers looked at four existing epigenetic studies of twins from the UK, Australia, the Netherlands and Finland that had taken either blood samples or cheek swabs to get DNA samples. They found 834 areas of DNA where the epigenetic pattern was different in identical twins compared with single births. Identical twins form when a very early embryo splits into two because the cells fail to adhere to each other, and some of the epigenetic changes found in this study affected genes involved in cell adhesion. “We may have identified a mechanism that causes cells to split,” says van Dongen. “It’s also possible that these changes arise after the cells separate.” With further development, it should be possible to create a genetic test to identify if you once had a twin embryo, says van Dongen. Any companies wishing to commercialise the research need to improve its accuracy, as, for instance, if someone had an identical twin embryo at some point during pregnancy, the current test would be positive only 70 per cent of the time, says van Dongen. What’s more, any test based on this work wouldn’t pick up people who had a non-identical twin embryo.
9-28-21 What it's like to be a nine-year-old in a vaccine clinical trial
In Charlottesville, Virginia, fraternal twins Evan and Lizzy are enrolled in Pfizer's vaccine trial for children between ages five and 11. The BBC follows them as they go to their second appointment where they receive a placebo or the vaccine. Their father, John, explains that though the family is very comfortable with the safety of the vaccine, consent from the children was the priority.
9-28-21 Australian researchers uncover fossil of new eagle species
Scientists in Australia say they uncovered a fossil of a previously unknown species of eagle that lived in the country about 25 million years ago. Dozens of bone fragments were uncovered by a dry lake in 2016 by researchers from Flinders University in Adelaide. A new study says the skeletal remains were of the Archaehierax sylvestris, or ancient hawk of the forest. Scientists believe the ancient raptor species survived by swooping on prey, including birds, possums and koalas. They say the eagle had adapted to hunting and flying within forests, with short robust wings, long legs and a wide foot-span. The discovery was made at an archaeological site in Lake Pinpa, a dried salt lake in the desert in south Australia. The area has been a rich site for palaeontologists uncovering fossils, but even then the remains of predators like hawks and eagles are hard to come by. Associate Professor Trevor Worthy said it was "rare to find even one bone from a fossil eagle" due to their small numbers at the time. "To have most of the skeleton is pretty exciting, especially considering how old it is," he said in a press release. The find dates from the Oligocene period, when the local climate would have been a rainforest rather than dry outback. Researchers described the 63 bones they found as an "exceptional partial skeleton" in a study published in the Historical Biology journal on Monday. Ellen Mather, an author of the study, said the Archaehierax sylvestris had unique features not seen in modern hawks and eagles. Researchers say the species had a foot span of almost six inches (15cm), allowing it to ambush and feast on prey like marsupials, ducks and flamingos.
9-27-21 Parasite evolution is making it harder to detect and treat malaria
Cheap rapid tests for malaria have helped drive down the prevalence of the disease in many parts of Africa. But just 15 years or so after their introduction, “stealthy” malaria parasites have evolved that can no longer be detected by the standard rapid tests. “This is a major threat to malaria control,” says Jane Cunningham at the World Health Organization Global Malaria Programme in Geneva. In many African countries, only people whose rapid test results are positive get treated. But in Eritrea around 2016, health workers noticed that many children who appeared to be really sick with malaria were testing negative. When medics looked at blood samples under a microscope, they could see many of the children were indeed infected. “It was a crisis situation,” says Cunningham. “They thought there was something wrong with the test.” Instead, her team found that up to 80 per cent of the malaria parasites in the area have mutations that mean they no longer produce the two proteins – called pfhrp2 and pfhrp3 – detected by the rapid tests. “Continued use of these rapid tests is selecting for [parasites without the two marker proteins] to proliferate,” says Cunningham. Her team then did a survey in neighbouring Ethiopia. “We didn’t find as high a prevalence as in Eritrea, but we found really concerning levels,” she says. Evolution is often a trade-off, with mutations that provide an advantage in one way being a disadvantage in another. But the parasites seem to thrive without the pfhrp proteins, whose function isn’t known. Areas with the mutant malaria parasite are switching to tests that detect another protein, but these tests aren’t yet as reliable – they are less heat stable, for instance. Switching to microscope detection isn’t an option in most places as it requires expensive equipment and skilled technicians.
9-27-21 Pfizer starts study of oral drug for preventing COVID-19
Pfizer has started testing an oral antiviral pill aimed at preventing COVID-19 infections, the pharmaceutical company announced Monday. The drug, PF-07321332, is designed to block the main enzyme the coronavirus needs to multiply, Pfizer said. PF-07321332 will be co-administered with a small dose of ritonavir, an antiviral that is used in combination with other medications to treat HIV. "If successful, we believe this therapy could help stop the virus early — before it has had a chance to replicate extensively — potentially preventing symptomatic disease in those who have been exposed and inhibiting the onset of infection in others," Mikael Dolsten, Pfizer's chief scientific officer and president of worldwide research, development, and medical, said in a statement. This antiviral could not only help treat people who will not get vaccinated against COVID-19, but would also be beneficial in countries where they expect it will take several years to get all residents fully vaccinated, Axios notes.
9-27-21 Mystery of ancient burrows older than earliest animals has been solved
The mystery of how animal burrows in Western Australia could be 400 million years older than the earliest animals in the fossil record has finally been solved. A new analysis suggests they were made far more recently than previously thought. These holes were thought to be 1.2 billion years old. “That’s twice as old as any known animal in the fossil record,” says Stefan Bengtson at the Swedish Museum of Natural History. He and his colleagues have re-analysed the 1.7-billion-year-old rocks of West Mount Barren on the coast of Western Australia in which the holes were dug. The burrows are about 15 to 20 millimeters wide and 15 centimetres deep and were first analysed 20 years ago. The researchers at the time determined that the rocks had hardened 1.2 billion years ago. And so the holes either had to have been made beforehand or by animals millions of years later that would have been able to penetrate the hard quartzite rock – which is essentially impossible to do. But Bengtson and his team discovered that the quartzite particles showed evidence of so much weathering that for about five to 10 million years, the rocks would have been easy to burrow into. The weathering had caused the rocks to turn into crumbly sandstone. “It’s not very common, but it happens, especially in hot and humid climate,” says Bengtson. By comparing the samples to other rocks and fossils in the area, and uranium-lead dating the minerals found in the burrows, the team estimated the holes were made 40 to 50 million years ago. The team found that the sandstone had subsequently hardened due to the arid conditions of the region, giving the impression that the burrows had been made much earlier than they actually were. The team is unsure what specific animals dug the holes, as burrows look different depending on the sediment they are made in. But Bengtson says they were most likely crustaceans.
9-27-21 Children with more books at home have less mental decline when older
Children who grow up in homes filled with books tend to have less cognitive decline when they reach old age, even when taking factors such as wealth and education into account. The finding suggests that early cognitive enrichment has long-lasting protective effects on the brain. Previous studies have found that children with large home libraries are more likely to do well at school and in their later careers. Ella Cohn-Schwartz at Ben-Gurion University of the Negev in Israel and her colleagues wondered whether the benefits of early book exposure extend into old age. They analysed data from more than 8000 men and women aged 65 and older without Alzheimer’s disease in 16 European countries, who had taken memory tests in 2011 and 2013 as part of the Survey of Health, Ageing and Retirement in Europe. The tests included trying to memorise lists of words and naming as many animals as possible in 1 minute. Participants were asked to recall roughly how many books their family homes contained when they were children: no books, one shelf (about 25 books), one bookcase (about 100 books), two bookcases or more. Those who grew up with larger book collections performed better in all memory tests. They also showed slower cognitive decline, with a smaller dip in their test scores between 2011 and 2013. This may be because their early book exposure encouraged them to read more, which in turn boosted their “cognitive reserve”, says Cohn-Schwartz. Intellectually stimulating activities like reading are known to create extra connections in the brain that buffer it against degenerative processes like those seen in Alzheimer’s disease. “It’s highly likely they built that buffer in the early stages of their childhood that has lasted them the distance,” says Ralph Martins at Edith Cowan University in Perth, Australia.
9-27-21 Covid-19 news: Antibodies remain in breast milk months after infection
The latest coronavirus news updated every day including coronavirus cases, the latest news, features and interviews from New Scientist and essential information about the covid-19 pandemic. Neutralising antibodies in breast milk may protect infants from covid-19 infection. Breastfeeding women who have had a covid-19 secrete neutralising antibodies against the virus into their breast milk for up to 10 months after infection, according to research presented at a conference. Rebecca Powell at Mount Sinai Hospital in New York and her colleagues analysed breast milk samples from 75 women who had recovered from a covid-19 infection. They found that 88 per cent of the samples contained antibodies against the SARS-CoV-2 virus, and in most cases they were capable of neutralising the virus. The findings, presented at the Global Breastfeeding and Lactation Symposium on 21 September, suggest that breastfeeding could help to protect babies from getting infected with covid-19. This is known to be the case for other respiratory diseases such as influenza and pertussis. While young children are at lower risk from severe covid-19 than adults, around one in 10 infants below the age of one require hospital care if they are infected. Antibodies extracted from breast milk could also be used as a therapy for adults with covid-19, Powell told The Guardian.The covid-19 pandemic has led to the biggest fall in life expectancy in western Europe since the second world war, researchers have found. The study, published in the International Journal of Epidemiology, included data from 29 countries, 22 of which saw a drop in life expectancy that was greater than half a year in 2020. The effects were larger for men than women in most countries. Men in the US saw the biggest fall, with 2.2 years taken off their life expectancy in 2020 compared with 2019. Australian authorities have announced plans to lift restrictions gradually in Sydney, which has been in lockdown since June. Restaurants, retail stores and gyms can begin to reopen on 11 October, but only people who are fully vaccinated will be allowed to resume shopping, eating out, and some other activities. Around 60 per cent of people aged 16 and over are currently fully vaccinated in the state of New South Wales.
9-27-21 50 years ago, scientists found a link between aspirin use and pregnancy complications
Excerpt from the October 2, 1971 issue of Science News Although aspirin has triggered defects in rat and mice fetuses, the evidence suggesting aspirin taken by women during pregnancy can harm their offspring has been circumstantial at best. Now, however … [evidence shows] that aspirin can dramatically arrest the growth of human embryo cells. Scientists are still sorting out how aspirin and other nonsteroidal anti-inflammatory drugs, collectively known as NSAIDs, affect pregnancy at every stage. Taking NSAIDs during the first trimester is known to increase the risk of miscarriage (SN: 11/5/11, p. 14). In 2020, the U.S. Food and Drug Administration warned that people who are 20 weeks or more into a pregnancy should avoid using NSAIDs altogether because the drugs can cause rare but serious kidney problems as well as heart problems for fetuses. However, exceptions can be made for pregnant people at risk of preeclampsia (SN: 7/13/91, p. 22), clotting and preterm delivery. In such cases, the FDA recommends that doctors prescribe the lowest effective dose of aspirin.
9-27-21 This is the oldest fossil evidence of spider moms taking care of their young
A 99-million-year-old spider trapped in amber sheds light on ancient arachnid parenting Long before Tyrannosaurus rex walked the Earth, sap engulfed a spider guarding her egg sac. Her corpse, preserved alongside her offspring in amber for 99 million years, is the oldest physical evidence for maternal care in spiders, says Paul Selden, an invertebrate paleontologist at the University of Kansas in Lawrence. This fossil is one of four showing that some ancient spiders guarded their egg sacs and may even have raised their young, Seldon and his colleagues report September 15 in Proceedings of the Royal Society B. Maternal care, such as guarding eggs, is common among modern spiders. Some species even go so far as nursing their young (SN: 10/29/18) or serving themselves up as their children’s first meal (SN: 4/21/15). Because maternal care is so widespread, researchers suspected that spiders developed this behavior long before the Cretaceous Period, which began around 145 million years ago. But this “is the first time we’ve seen evidence for this behavior in fossils,” says Selden. The female spider and her unborn offspring belong to a now-extinct family of spiders called Lagonomegopidae, distinguished by their large, reflective eyes. She and her kin would probably have hunted in trees at night. Along with guarding her eggs, the female spider may have stuck around after her eggs hatched. Three of the chunks of amber contain dozens of week-old spiders. Spiders are usually solitary creatures, so the presence of multiple spiderlings side-by-side suggests that they didn’t disperse after birth, choosing instead to stay alongside their mother. How long these spiders stuck around mom remains unclear. While the study “unequivocally” shows that these spiders were guarding their egg sacs during the mid-Cretaceous, “future researchers need to keep their eyes open for females with larger and older offspring,” says Linda Rayor, an entomologist at Cornell University who studies maternal care in spiders.
9-26-21 Pfizer CEO expects to submit children's COVID-19 vaccine data to FDA in days
Pfizer CEO Albert Bourla said Sunday that the company is planning to submit the data it compiled from COVID-19 vaccine trials for children between the ages of 5 and 11 to the Food and Drug Administration quite soon. "It's a question of days, not weeks," he told ABC News' George Stephanopoulos on Sunday's edition of This Week. Last week, Pfizer revealed that the vaccine it developed in tandem with BioNTech was safe and effective within the age group even with a smaller dose than the one that's been approved for ages 12 and up. Once the FDA can review that information, the vaccine will be on track to become available for younger children, which will likely go a long way toward solidifying pandemic-related education policies throughout the U.S.
9-23-21 DNA offers a new look at how Polynesia was settled
Voyagers migrated to islands sprinkled across a large area of the Pacific within about 500 years. Polynesian voyagers settled islands across a vast expanse of the Pacific Ocean within about 500 years, leaving a genetic trail of the routes that the travelers took, scientists say. Comparisons of present-day Polynesians’ DNA indicate that sea journeys launched from Samoa in western Polynesia headed south and then east, reaching Rarotonga in the Cook Islands by around the year 830. From the mid-1100s to the mid-1300s, people who had traveled farther east to a string of small islands called the Tuamotus fanned out to settle Rapa Nui, also known as Easter Island, and several other islands separated by thousands of kilometers on Polynesia’s eastern edge. On each of those islands, the Tuamotu travelers built massive stone statues like the ones Easter Island is famed for. That’s the scenario sketched out in a new study in the Sept. 23 Nature by Stanford University computational biologist Alexander Ioannidis, population geneticist Andrés Moreno-Estrada of the National Laboratory of Genomics for Biodiversity in Irapuato, Mexico, and their colleagues. The new analysis generally aligns with archaeological estimates of human migrations across eastern Polynesia from roughly 900 to 1250. And the study offers an unprecedented look at settlement pathways that zigged and zagged over a distance of more than 5,000 kilometers, the researchers say. “The colonization of eastern Polynesia was a remarkable event in which a vast area, some one-third of the planet, became inhabited by humans in … a relatively short period of time,” says archaeologist Carl Lipo of Binghamton University in New York, who wasn’t involved in the new research. Improved radiocarbon dating techniques applied to remains of short-lived plant species unearthed at archaeological sites are also producing a chronology of Polynesian colonization close to that proposed in the genetic study, Lipo says.
9-22-21 Psychonauts 2 review: A fun yet sensitive take on mental health
THESE days, film and TV are full of revivals: continuations of a much-loved story decades later that are a chance to revisit favourite characters when they are older and perhaps wiser. In recent years, I have enjoyed returning to the worlds of Jurassic Park, Twin Peaks and Veronica Mars to name just a few. Of course, there is always the chance that revivals go wrong – the most recent season of The X-Files probably should have remained buried in an FBI vault somewhere. It’s this risk that had me holding my breath before beginning Psychonauts 2, a sequel to one of my favourite video games of all time. The original Psychonauts, a cult classic, came out more than 15 years ago, a gap almost unheard of in an industry that tends to release yearly sequels. Barring a brief virtual-reality spin-off in 2017, I wasn’t expecting to see another instalment. Thankfully, I needn’t have worried about this revival. The new game’s story picks up just three days after the end of the first one, which saw a young boy called Raz attend a summer camp for individuals with psychic abilities run by the Psychonauts, a kind of psychic spy agency. Here, he learned to dive into people’s minds and help them come to terms with their deepest fears. In Psychonauts 2, Raz becomes an intern for the organisation. The structure of the game is much the same – exploring weird and wonderful mindscapes – but its approach to mental health has grown in sophistication. “We’re not here to change people’s minds, not here to fix people,” one of the Psychonauts tells Raz early in the game. “We’re here to help people fight their own demons.” The entire game sparkles with wit and creativity, without shying away from serious issues. For example, one level involves Raz helping someone with a fear of judgement. This manifests in his mind as a bizarre version of The Great British Bake Off, in which Raz has to prepare a variety of anthropomorphic ingredients (which are all very cute and extremely enthusiastic about being cooked) before presenting the results to a panel of judges.
9-22-21 Story of epic human voyages across Polynesia revealed by genetics
A genetic study has helped shine a light on how the Polynesian islands of the central and southern Pacific – some of which are thousands of kilometres apart – were populated over the past thousand years. Alexander Ioannidis at Stanford University in California and his colleagues analysed the DNA of 430 people of Polynesian descent to map their genetic ancestry. Polynesia is made up of around 1000 islands that span one-third of the world. It includes New Zealand, Hawaii, Easter Island (Rapa Nui) and Samoa. People from Asia are believed to have reached Samoa, thought to be the first island in Polynesia to be inhabited, about 3000 years ago. These people – probably using double-hulled canoes – went on to populate several other islands in the Pacific. “We’ve had a general idea of how the islands of Polynesia were populated,” says Ioannidis. “But this is the first study to give us a far more detailed picture.” The researchers first had to figure out the order in which the islands were discovered. They did this by taking advantage of a genetic phenomenon called the founder effect, in which there is reduced genetic variation within a population if there are few initial members. This can happen when a small number of people settle on an island. If a small subset of that population then goes on to settle on another island, a second founder effect occurs, reducing genetic diversity again in a subtle but detectable way – and so on. By comparing the total genetic diversity in the DNA of the study’s participants across the islands, the team was able to tell which populations came from where first. The first migration across the ocean was from Samoa to the Cook Islands – a voyage of 1550 kilometres – around AD 830, according to the researchers. The team then determined clearer dates for the migrations by comparing specific DNA sequences in the genomes of the study’s participants. If two Polynesian people on different islands have specific identical parts in their DNA, it means they share an ancestor.
9-22-21 A third of the world's food goes to waste – here's how to stop the rot
Food waste isn't just morally objectionable; it also produces vast amounts of greenhouse gases. But this is one food fight we can win, with simple actions at home and new tech in industry. DeI OFTEN feel guilty in the kitchen. The problem isn’t my cooking; I live in France and pride myself on my culinary skills. The cause of my guilt is the amount of food I keep throwing away. A pile of leftover pasta, the uneaten salmon from my daughter’s plate, some expired tofu discovered at the back of the fridge – in it all goes. It sits there in a heap on top of the plastic packaging in which most of the food came wrapped. It might be a modest heap in my kitchen bin, but, worldwide, food waste is a problem of supersized proportions. About a third of all produce is lost or wasted, most of it thrown into landfill. As that food rots, it produces vast amounts of greenhouse gases. If food waste were a country, its carbon footprint would almost match that of the US. You might say that instead of cooking our food, we are cooking the planet. No wonder that scientists, campaigners – and plenty of ordinary folk like me – are deeply worried. I decided to turn to science and ask what we really know about how to make sure less food is squandered. It was eye-opening, to say the least. I have changed the way I shop and eat. My preferences on the way food is packaged have been transformed. I also learned that the food industry is at the beginning of some sweeping technological shifts, which could see food waste become not a problem, but an opportunity. For most of human history, sustenance has been hard won and not something we would have dreamed of wasting. I grew up in communist Poland. I remember the food shortages people experienced back then and how my mother cried when mice once got into our stock of sugar. Millions of people still live in food poverty. But those in richer parts of the world now have the dubious luxury of being able to waste food.
9-22-21 Everyday aches: Why it’s time to take minor ailments more seriously
There’s a lot that can go slightly wrong with the human body and most of the time science can’t explain why. But even our unremarkable illnesses deserve closer inspection. FOR a few months last year, I broke the habit of a lifetime and started keeping a diary. I hadn’t taken a sudden interest in recording my innermost thoughts, I was conducting a scientific-experiment-cum-book-project. I called it my “Mustn’t Grumble” diary; every evening, I noted down all of my minor health woes from that day. Keeping a record confirmed what I had suspected – that I’m constantly slightly ill. Highlights included a cold, a twitchy eyelid that drove me nuts for three days and a terrifying loss of taste and smell. There was also the tedious matter of my chronically sore shoulder and athlete’s foot. All in all, I battled dozens of minor ailments. I hesitate to extrapolate my findings to claim that everyone is a bit ill all the time, but I have yet to come across somebody who isn’t. Think about it: when was the last time you enjoyed a day when there was absolutely nothing wrong with you? And yet there is no formal scientific definition of a minor ailment, and medical understanding of such conditions is often surprisingly rudimentary. This should be a big issue, because about three-quarters of family doctor appointments in the UK are for conditions that rarely require medical intervention, such as back pain, dermatitis, indigestion, coughs and sprains. In the US, about 25 million people a year visit their doctor with common colds. Even so, the coronavirus pandemic has dragged us back into a world where someone with a sniffle or high temperature can be gravely ill or even dead in a week. It is time for a major re-evaluation of minor ailments. Obviously, there are occasions when we are properly ill – forced to retreat to our beds or make a doctor’s appointment. I’m not talking about that level of illness. I’m referring to the mild, irritating ailments and aches and pains that niggle us on a daily basis: headaches, coughs and sneezes, backache, cuts and bruises, zits, hay fever, heartburn, nosebleeds, constipation, insect bites and the rest. There is a lot that can go slightly wrong. All told, my research into the subject covers more than 100 minor ailments.
9-22-21 Changing how drugs are approved in England mustn't endanger safety
LAST month, plans were announced to change the way new medicines are assessed by the National Institute for Health and Care Excellence (NICE). This body decides which medicines can be used in the National Health Services in England and Wales. While some proposals are clearly welcome, like getting firms to put submissions to NICE in plain English, others require caution, like accepting less rigorously conducted trials as supporting evidence. NICE says the changes are designed to speed up the introduction of new medicines and support innovation by pharmaceutical companies. It also wants to encourage drug companies to
9-23-21 'This is a dream find': Scientists' 'bombshell' discovery in the 'peopling' of America
Astonishingly old" human footprints preserved in the ground across New Mexico's White Sands National Park have been determined to date back about 23,000 years to the Ice Age, a finding which, if certified, "would rejuvenate the scientific debate about how humans first spread across the Americas," The New York Times reports. "I think this is probably the biggest discovery about the peopling of America in a hundred years," said Ciprian Ardelean, an archaeologist at Autonomous University of Zacatecas in Mexico who was not involved in the discovery. "I don't know what gods they prayed to, but this is a dream find." For years, many archaeologists have maintained that humans "spread across North and South America only at the end of the last ice age," writes the Times. And starting in the 1970s, some researchers began to go back even further for humanity's presence in North America — some 26,000 years. But of the fossils and ancient finds they pointed to to support such a hypothesis, "none of them are unequivocal," said archaeologist Ben Potter; layers of sediment, perhaps, may have made a find appear older than it really is. The footprints, however, are far more definitive pieces of evidence that suggest humans journeyed across the Americas "when massive glaciers covered much of their path," writes the Times. "What is fascinating about the study of footprints is that they present snapshots in time," said Dr. Mathew Stewart, a zooarchaeologist not involved in the study. "This is a bombshell," added Ruth Gruhn, another archaeologist, of the study. "On the face of it, it's very hard to disprove." On that note, Dr. Potter said he would still like to see some stronger data; if it is true, however, he notes the discovery would have "some profound implications." Read more at The New York Times.
9-24-21 Dinosaurs: 'Bizarre' fossil is Africa's first ankylosaur
"Think of a coffee table. Short, broad, covered in spikes and walking towards you. That's an ankylosaur!" Dr Susie Maidment is describing a fabulous new fossil in her possession. All she has is a section of rib with prongs attached. But even from just this, the palaeontologist can tell it's a novel species of armoured dinosaur and the oldest ankylosaur ever found. What's more, it's come out of Africa, from Morocco, where these creatures have never been unearthed before. That's exciting enough but there's also something very strange about this ancient specimen. The spikes are fused directly to the bone, and this is a big puzzle, says Dr Maidment, who's affiliated to London's Natural History Museum (NHM). Ordinarily, you would expect rib bones to be covered by muscle, and then by skin, and for the armour - made of a protein called keratin, like your fingernails - to be sitting on top of that. But for the spikes to be connected straight through to the bone is just odd. For one thing, you'd think this would restrict the extension of the muscles and make it difficult for the animal to move. "Honestly, it's bizarre," Dr Maidment told BBC News. "We don't see this in any other extant (still living) or extinct vertebrate anywhere. It's a totally unprecedented morphology in the history of life on Earth." Dr Maidment's team were so taken aback by the fossil, they wondered for a while whether it might actually be a fake, or not an ankylosaur at all; perhaps it was some monster fish never previously identified. But with detailed scanning and further investigations, it's been possible to rule out both alternatives. Most of us are probably more familiar with stegosaurs. They were the armoured dinosaurs that had a row of imposing plates down their spine. You'll see a magnificent specimen, nicknamed Sophie, if you visit the NHM. Ankylosaurs were their evolutionary cousins. And very successful they were, too. They lived right through the Cretaceous, right up to the moment the asteroid struck 66 million years ago to wipe out 75% of all plant and animal species on the planet. When precisely the ankylosaurs first emerged, however, is still being studied, which makes this newly reported specimen extra special. It dates to the Middle Jurassic Period, around 168 million years ago.
9-24-21 Footprints in New Mexico are oldest evidence of humans in the Americas
Humans reached the Americas at least 7,000 years earlier than previously thought, according to new findings. The topic of when the continent was first settled from Asia has been controversial for decades. Many researchers are sceptical of evidence for humans in the North American interior much earlier than 16,000 years ago. Now, a team working in New Mexico has found scores of human footprints dated to between 23,000 and 21,000 years old. The discovery could transform views about when the continent was settled. It suggests there could have been great migrations that we know nothing about. And it raises the possibility that these earlier populations could have gone extinct. The footprints were formed in soft mud on the margins of a shallow lake which now forms part of Alkali Flat in White Sands. The research has been published in the journal Science. A team from the US Geological Survey carried out radiocarbon dating on seeds found in sediment layers above and below where the footprints were found. This gave the researchers remarkably precise dates for the impressions themselves. Based on their sizes, scientists think the tracks were made mainly by teenagers and younger children travelling back and forth - along with the occasional adult. They offer a fascinating window into what life was like for these early occupants of what is now the South West US. The scientists don't know for sure what the teenagers were doing, but it is possible they were helping the adults with a type of hunting custom seen in later Native American cultures. This was known as the buffalo jump and involved driving animals over a shallow cliff edge. The animals "all had to be processed in a short period of time," explained Dr Sally Reynolds, co-author from Bournemouth University. "You'd have to start fires, you'd have to start rendering the fat." The teenagers could have been helping out by collecting firewood, water or other essentials. The age of the discovery is key, because there have been countless claims of early human settlement in the Americas. But virtually all are disputed in some way.
9-24-21 How our ape ancestors suddenly lost their tails 25 million years ago
Around 25 million years ago, our ancestors lost their tails. Now geneticists may have found the exact mutation that prevents apes like us growing tails – and if they are right, this loss happened suddenly rather than tails gradually shrinking. “You lose the tail in one fell swoop,” says Itai Yanai at NYU Langone Health in New York. His colleague Bo Xia says he used to wonder as a child why people didn’t have tails like other animals. “This question was in my head when I was a little kid,” he says. “I was asking, ‘Where is my tail?’.” More recently, Xia’s coccyx – a small bit of bone at the base of the spine that is a vestige of mammalian tails – was injured in a car accident. “It was really painful,” he says. “It kept reminding me about the tail part of our body.” That led Xia to investigate the genetic basis of tail loss. Any mutations involved in tail loss should be present in apes but not monkeys. He and his colleagues compared ape and monkey versions of 31 genes involved in tail development. They found nothing in the protein-coding regions, so they looked in the bits of junk DNA found inside genes. If you think of proteins as flat-pack furniture, the genetic instruction booklets for making them come with lots of pages of gibberish that have to be removed before the instructions work. These extra bits, called introns, are cut from the mRNA copies of genes before proteins are made. What Xia found is that in the ancestor of apes, in a tail gene called TBXT, an Alu element landed smack bang in the middle of an intron. Alu elements are genetic parasites that copy and paste themselves all over the genome. “We have 1 million Alu elements littering our genome,” says Yanai. Normally, an Alu in an intron would make no difference – it would get edited out with the intron. But in this case, there is another Alu element nearby, but it is in inverse order. Because the two sequences are complementary, Xia realised, they bind together, forming a loop in the mRNA.
9-24-21 ‘Ghost tracks’ suggest people came to the Americas earlier than once thought
If confirmed, newly described footprints could help rewrite textbooks. Footprints left behind by prehistoric people may be some of the strongest evidence yet that humans arrived in the Americas earlier than previously thought. Over 60 “ghost tracks” — so-called because they pop up and disappear across the landscape — show that people romped through what’s now New Mexico 23,000 to 21,000 years ago, geoscientist Matthew Bennett and colleagues report in the Sept. 24 Science. If true, the fossil findings would be definitive proof that humans were in North America during the height of the last ice age, which peaked around 21,500 years ago. When people first arrived in the Americas is highly contested. Scientists have historically thought that humans traveled across the Bering land bridge that connected Asia to North America around 13,000 years ago, after the massive Laurentide Ice Sheet that once blanketed much of North America had started retreating into the Arctic (SN: 6/26/18). But a slew of more recent discoveries from across North and South America — including roughly 30,000-year-old animal bones from a Mexican cave (SN: 6/9/21) and stone tools from Texas (SN: 7/11/18) — suggest that humans may have arrived far earlier. At White Sands National Park in New Mexico, Bennett, of Bournemouth University in Poole, England, and colleagues used several methods to calculate the ages of the newly described tracks, including radiocarbon dating of aquatic plants embedded in and between the footprints. “One of the beautiful things about footprints is that, unlike stone tools or bones, they can’t be moved up or down the stratigraphy,” he says. “They’re fixed, and they’re very precise.” But some archaeologists aren’t yet convinced of the footprints’ ages. Loren Davis, an anthropologist at Oregon State University in Corvallis, says that he would like to see the researchers use other validation techniques to check the dates before “breaking out the champagne.”
9-22-21 Dinosaurs may have waggled their tails to help walk more efficiently
When bipedal dinosaurs walked, they probably strode with a swagger, swishing their tails up and down for the same reason humans swing their arms when they walk. Traditionally, dinosaur tails have been seen as a counterbalance for the weight of a dinosaur’s head. But John Hutchinson and Peter Bishop at the Royal Veterinary College in London say the tail probably played a more active role in a dinosaur’s gait. With every step, the tail would swing up and down to regulate the dinosaur’s angular momentum and increase its walking efficiency. This comes from a computer simulation of Coelophysis bauri, a bipedal dinosaur that lived between about 220 to 195 million years ago. Hutchinson and Bishop and their colleagues designed the simulation as part of an ongoing research project aimed at better understanding the locomotion of early dinosaurs. To build an accurate biomechanical model of a long-extinct species, the team first turned to modern birds called tinamou (for instance a species called Eudromia elegans), which are small birds that prefer running to flying. By grafting a virtual model of a tinamou’s musculature onto a computerised version of its skeleton, the simulation was able to accurately replicate the tinamou’s gait. Hutchinson and Bishop then applied the simulation to the muscular and skeletal structure of C. bauri. The simulation didn’t perform exactly as expected. “Looking closely,” says Hutchinson, “we realised the tail was doing some rather funny stuff.” Instead of statically extending backward as expected, the tail was an active participant in locomotion. With every step, it would bob up and down twice and swing left and right once, matching the head and leg movements. To understand the role the tail was playing, the team deleted the tail from their computer model. When this happened, they found that the rest of the dinosaur’s muscles had to work 18 per cent harder to maintain a consistent running speed, suggesting that the tail’s movements made for more efficient steps. “By understanding how real, living animals work, we can make better inferences about how extinct ones worked,” says Hutchinson.
9-22-21 Covid: Immune therapy from llamas shows promise
A Covid therapy derived from a llama named Fifi has shown "significant potential" in early trials. It is a treatment made of "nanobodies", small, simpler versions of antibodies, which llamas and camels produce naturally in response to infection. Once the therapy has been tested in humans, scientists say, it could be given as a simple nasal spray - to treat and even prevent early infection. Prof James Naismith described nanobodies as "fantastically exciting". Prof Naismith, who is one of the lead researchers and director of the Rosalind Franklin Institute in Oxfordshire, explained that coronavirus-infected rodents treated with the new nanobody nasal spray fully recovered within six days. The treatment has, so far, been tested only in those lab animals, but Public Health England said it was among the "most effective SARS-CoV-2 neutralising agents" it had ever tested. This apparent covid-fighting potency comes from the strength with which nanobodies bind to the virus. Just like our own antibodies, virus-specific nanobodies latch on to and bind to viruses and bacteria that invade our bodies. This binding essentially tags an invading virus with an immune "red flag", to allow the rest of the body's immune armoury to target it for destruction. The nanobodies that these researchers produced - with the help of a llama's immune system - bind particularly tightly. "That's where we had some help from Fifi the 'Franklin [Institute] llama'," explained Prof Naismith. By vaccinating Fifi with a tiny, non-infectious piece of the viral protein, the scientists stimulated her immune system to make the special molecules. The scientists then carefully picked out and purified the most potent nanobodies in a sample of Fifi's blood; those that matched the viral protein most closely, like the key that best fits a specific lock. The team was then able to grow large quantities of the specially selected, most potent molecules.
9-22-21 Why only some people may get COVID-19 booster shots at first
Experts want more data before making the jabs more widespread. In the United States, it’s looking like booster shots of Pfizer-BioNTech’s COVID-19 vaccine won’t be widely available to the general public starting this week. A panel of expert advisers to the U.S. Food and Drug Administration unanimously recommended September 17 that boosters next be allowed for only certain groups: people 65 years and older, individuals at high risk of severe COVID-19 and those with jobs that put them at high risk of exposure. That’s more limited in scope than what the Biden administration proposed in August. Officials had announced plans to offer a third dose of Pfizer-BioNTech’s vaccine to the general public at least six months after vaccination starting September 20, pending an OK from the FDA. Since officials unveiled that plan, it’s been widely debated. Some researchers — including Pfizer scientists — argue that because the vaccine’s protection against infections is waning, that could foreshadow a possible dip in protection against severe disease too. So the time to bolster everyone’s protection with a third dose is now, these researchers say. But others disagree, contending that it’s more important to focus on getting doses to unvaccinated people first, and that many younger, healthy vaccinated people remain well-protected against severe disease and death after just two doses. Third doses are already authorized for moderately to severely immunocompromised people who may not develop good protection from the initial shots (SN: 7/23/21). The case for another dose was obvious for that group, says Mark Slifka, a viral immunologist at Oregon Health & Science University in Portland who wasn’t involved with the FDA panel. The data were “clear as day that the third dose was important” and could help boost the levels of protective antibodies in some patients.
9-21-21 We can now bioengineer catnip instead of extracting it from plants
The key ingredient in catnip, called nepetalactone, can now be brewed in genetically engineered yeast. The chemical is a highly effective insect repellent, but catnip plants (Nepeta cataria) don’t contain enough of it to make production from these commercially viable. Insect repellents can help prevent serious diseases such as malaria, as well as nuisance bites. DEET is the most widely used mosquito repellent worldwide and is often still the most effective. However, some mosquito populations are evolving resistance to DEET, so alternatives are needed. Many studies have shown that nepetalactone is an effective insect repellent, with some even finding it more effective than DEET. Yet while catnip in various forms has long been used as a repellent, mass production of a cheap version isn’t feasible using the plant. Instead, Vincent Martin and his colleagues at Concordia University in Canada added eight extra genes to a strain of yeast, including some key enzymes from catnip, to create a chemical pathway for nepetalactone production. “We still need to do some work to boost levels,” says Martin. “I don’t believe it will be a huge hurdle.” The main obstacle is that the process also produces a substance toxic to the yeast. However, other groups engineering yeasts to produce various chemicals have had the same problem, and have solved it, Martin says. The researchers are now in discussion with companies about getting the investment needed to develop the yeast further and commercialise the process. They will also need to look at whether nepetalactone acts as a cat attractant as well as an insect repellent. “If you are walking around with this molecule on you, will there be no mosquitoes, but all the neighbourhood cats chasing you around? To be honest, I don’t know,” says Martin. “That’s certainly something we’re going to have to investigate.”
9-20-21 Stroke rehab should be offered for months longer than it currently is
People who have experienced a stroke may benefit from being treated with physiotherapy for much longer than is typically the case, to take best advantage of a critical window for rehabilitation exercises. Strokes involve damage to brain tissue caused by a blood clot or a burst blood vessel, which can leave people unable to use an arm or leg, for instance. People generally do recover some function as time passes, especially with physiotherapy. This is thought to be because the brain forms new neural pathways to replace the ones lost, an example of a rewiring process called neuroplasticity. To investigate the benefits of physio, Elissa Newport at Georgetown University Medical Center in Washington DC and her colleagues studied the effects of giving an extra 20 hours of treatment, on top of usual rehab, to 72 people who had a stroke that affected an arm. Each participant was randomly assigned to receive up to 3 hours of physiotherapy a day, either in the first month after the stroke, between months two and three, after six months or not at all. After one year, people who got the extra therapy between months two and three improved the most, by nearly seven points on a commonly used 57-point scale for rating physical ability, compared with usual care. That could mean the difference between being able to dress independently and not, says Newport. People who got the extra therapy in the first month improved by about five points, and people who got it after six months showed no significant benefit. The difference between treatment in the first month and from months two to three wasn’t statistically significant. But the fact that benefits were seen during the third month contradicts the prevailing belief that for post-stroke rehab, “the earlier the better”, says Newport. In the US, most stroke survivors get rehab only for the first four weeks, while in the UK it tends to last up to six weeks.
9-17-21 Woman who first gained sense of smell at age 24 finds it disturbing
A woman who was born without the brain regions required for smell has mysteriously started smelling things for the first time in her twenties and finds it highly unpleasant. The woman was diagnosed with congenital anosmia – the inability to smell – when she was 13. Brain imaging revealed she was missing the olfactory bulbs in her forebrain that detect odour information from the nose and transmit it to other parts of the brain involved in smell perception. Then, when she was 24, she had an unexpected smell awakening. She suddenly began noticing scents like lavender, garlic and manure, with a new smell experience occurring every few weeks. The woman reported feeling disturbed by her new sense, and the fact that she disliked almost all the new smells she encountered increased her anxiety. On one occasion, she felt so overwhelmed she fainted. A group of smell specialists at the University of Dresden Medical School in Germany conducted tests to try to understand how she had learned to smell. They presented her with 32 scents and found she could smell half of them. She could detect orange, mint, smoke, turpentine, ginger and lilac, for example, but not coconut, banana, leather, liquorice or cocoa. “It’s not like she only smells food-related things or bad odours, it’s all over the place,” says Thomas Hummel at the University of Dresden Medical School, one of her specialists. Next, they monitored her brain activity when she sniffed rotten egg gas and rose perfume using electroencephalography (EEG). This confirmed that her brain was responding to the odours. But brain imaging showed she still had no olfactory bulbs, leaving her medical team puzzled. A 2019 study by researchers at the Weizmann Institute of Science in Israel described five women who could smell normally despite having no olfactory bulbs, suggesting the brain can find alternative ways to smell in rare cases. “But the scientific community has been kind of silent on this because no one can explain how,” says Hummel.
9-17-21 By taking on poliovirus, Marguerite Vogt transformed the study of all viruses
When nobody else wanted the job, Marguerite Vogt stepped in. Working from early morning until late at night in a small, isolated basement laboratory at the California Institute of Technology, Vogt painstakingly handled test tubes and petri dishes under a fume hood: incubating, pipetting, centrifuging, incubating again. She was trying to grow a dangerous pathogen: poliovirus. It was 1952 and polio was one of the most feared diseases in America, paralyzing more than 15,000 people, mostly children, each year. Parents wouldn’t let their children play outside, and quarantines were instituted in neighborhoods with polio cases. Scientists were desperate for information about the virus, but many were hesitant to work with the infectious agent. “Everybody was afraid to go to that little lab in the basement,” says Martin Haas, professor of biology and oncology at the University of California, San Diego, and a personal friend and collaborator of Vogt’s for over three decades. Vogt, a brand-new research associate in the laboratory of Renato Dulbecco, took on the task of attempting to grow and isolate the virus on a layer of monkey kidney cells. The method was called a plaque assay for the distinctive round plaques that form when a single virus particle kills all the cells around it. Vogt didn’t tell her parents, both acclaimed scientists in Germany, that she was working with the virus. She later remarked that her father would have been very angry had he known of her poliovirus work, Haas says. After a year of persistence, Vogt succeeded (and remained virus-free). In 1954, she and Dulbecco published the method for purifying and counting poliovirus particles. It was immediately used by other scientists to study variants of poliovirus, and by microbiologist Albert Sabin to identify and isolate strains of weakened poliovirus to make the oral polio vaccine used in mass vaccination campaigns around the world.
9-17-21 Stone Age people used bone scrapers to make leather and pelts
At least 90,000 years ago, humans probably employed the tools to fashion clothes from animal skins. Discoveries in a Moroccan cave have provided a rare look at how Stone Age people may have turned animal skins into clothing. Bone tools, including hide scrapers and stone-tool sharpeners, were unearthed in Morocco’s Contrebandiers cave, say archaeologist Emily Hallett and colleagues. Dating of sediment, burned stones and animal teeth excavated there shows that the tools are around 90,000 to 120,000 years old, the scientists report September 16 in iScience. “Prior to major successful dispersals out of Africa and into Eurasia, Homo sapiens [were] making tools for various specialized functions, and those behaviors would have aided them [in] new environments,” says Hallett, of the Max Planck Institute for the Science of Human History in Jena, Germany. Different types of bone tools from around the time of the Moroccan finds have been unearthed at a handful of other African sites, though uses for many of those items remain unclear. Researchers have largely focused on an explosion of African bone tool styles that appeared around 44,000 years ago, after human expansions into Eurasia. Of 62 bone implements from the cave, seven were hide scrapers. These tools were crafted from pieces of antelope or wild cattle ribs that were split in half lengthwise and worked into a flat, spatula-like shape. Short, deep grooves and polish on these items resulted from scraping animal hides, the researchers say. The team unearthed the tools along with skinned animals’ bones. Patterns of stone-tool incisions on limb and jaw bones of sand foxes, golden jackals and wildcats resulted from detaching skin at the paws and pulling it over the head in one piece, providing evidence for the way the bone hide scrapers were used, the scientists say.
9-17-21 Fossil tracks may reveal an ancient elephant nursery
Preserved footprints of newborn pachyderms are roughly the size of drink coaster. Fossilized footprints found on a beach in southern Spain betray what may have been a nursery for an extinct species of elephant. The track-rich coastal site, which scientists have dubbed the Matalascañas Trampled Surface, is typically covered by 1½ meters of sand, says Clive Finlayson, an evolutionary biologist at the Gibraltar National Museum. But storm surges in the spring of 2020 washed away much of that sand and exposed the preserved footprints of ancient elephants, cattle, deer, pigs, wolves, water birds and even Neandertals, Finlayson and colleagues report September 16 in Scientific Reports. The sandy-clay sediments hosting this trove of tracks were probably laid down about 106,000 years ago, previous studies suggest. Among the newly uncovered tracks are the first-of-their-kind footprints of newborn straight-tusked elephants (Palaeoloxodon antiquus), an extinct species that probably died out during the last ice age (SN: 6/13/17). The teeny tracks — which measure 9.6 centimeters across, about the size of a drink coaster — suggest that the petite, possibly 2-month-old pachyderms stood about 66 centimeters tall at their shoulders and weighed around 70 kilograms, slightly heftier than a Newfoundland dog. Based on previous finds elsewhere of actual bones, adult straight-tusked elephants may have weighed 5.5 metric tons for females and a whopping 13 tons for males. The mix of elephant tracks at the site suggests that family groups including newborns, juveniles and adult females frequented the area and possibly used it as a nursery, the researchers say. Other fossils found at the site, including those preserving traces of ancient roots, hint that the area was rich in vegetation and speckled with lakes and ponds.
9-16-21 Prehistoric elephant nursery probably made easy prey for Neanderthals
More than 100,000 years ago, elephants raised their newborns among the dunes of the ancient Spanish coast. Fossil footprints suggest at least 14 calves, belonging to the extinct straight-tusked elephant (Palaeoloxodon antiquus), were part of a prehistoric nursery – and that they were hunted by Neanderthals. Carlos Neto de Carvalho at the Naturtejo UNESCO Global Geopark in Portugal and his colleagues identified the tracks on a broad fossil surface called the Matalascañas Trampled Surface (MTS) in Huelva, Spain, that contains the footsteps of antelope, birds, wolves and even Neanderthals. The researchers identified 34 sets of footprints attributed to the straight-tusked elephants, the local elephant species during the time the tracks were made – about 100,000 years ago, according to geological analysis of the rocks. Most of the footprints were left by infants that weighed between 70 and 200 kilograms. The tracks of adult elephants are rarer at the MTS site, but, based on track size, the researchers hypothesise that there are footprints of three adult females there. The footprint records match ecological observations of modern elephants, says de Carvalho, in which youngsters stay near to adult females with larger adult males rarely being present. “We describe elephant nursery and reproductive ecology in the fossil record for the first time,” he says. At the time the straight-tusked elephants roamed around what is now Huelva, the MTS was a pond that acted as a water source between coastal sand dunes. The water and nearby vegetation probably made a comfortable nursery for the young calves. But the secluded beach spot wasn’t free from predators. Footprints of Neanderthals have been discovered in the same track layers and researchers have even found stone tools made by the prehistoric people. While signs of interactions between people and pachyderms at the site have yet to appear, the team suggests that Neanderthals were drawn to the prospective hunting ground by the abundance of elephant calves. “A newly born elephant could be easy prey and just a delicious item in the Neanderthal menu,” says de Carvalho.
9-16-21 Having HPV while pregnant linked to increased risk of premature birth
Pregnant women infected with the human papillomavirus (HPV), which causes cervical cancer, are nearly four times more likely to give birth prematurely. The finding suggests that as more teenagers are vaccinated against HPV, there will be fewer premature births, says Helen Trottier at the University of Montreal in Canada. Premature babies are born smaller and are more prone to infections and numerous other health problems. HPV is a sexually transmitted virus that is shrugged off naturally by most people, but it can linger and cause cervical cancer, as well as anal and throat cancers and genital warts. Most high-income countries started offering HPV vaccination to teenagers about a decade ago. Rates of genital warts have started falling, although any effect on cervical cancer rates is taking longer to show up, as it takes many years to develop. Trottier wondered what the effects of the virus would be on pregnant women. Her team tested nearly 900 women for HPV in their vaginal fluid in the first and last three months of pregnancy. About 42 per cent tested positive at the start, and two-thirds of these still had the virus by the end. Those who had HPV throughout their pregnancy were 3.7 times more likely to either spontaneously go into early labour, or need to be induced to give birth early due to complications, compared with those who tested negative at the start. “We were surprised to see how strong was the association,” says Trottier. If the virus is directly causing the premature labour, the mechanism is unclear. HPV doesn’t cause inflammation, one known cause of premature births, but it could damage cells of the cervix, making them more vulnerable to bacterial infections that do cause inflammation, says Trottier.
9-16-21 Fossils and ancient DNA paint a vibrant picture of human origins
A century of science has begun to explain how and where Homo sapiens and our kin evolved. In The Descent of Man, published in 1871, Charles Darwin hypothesized that our ancestors came from Africa. He pointed out that among all animals, the African apes — gorillas and chimpanzees — were the most similar to humans. But he had little fossil evidence. The few known human fossils had been found in Europe, and those that trickled in over the next 50 years came from Europe and from Asia. Had Darwin picked the wrong continent? Finally, in 1924, a fortuitous find supported Darwin’s speculation. Among the debris at a limestone quarry in South Africa, miners recovered the fossilized skull of a toddler. Based on the child’s blend of humanlike and apelike features, an anatomist determined that the fossil was what was then popularly known as a “missing link.” It was the most apelike fossil yet found of a hominid — that is, a member of the family Hominidae, which includes modern humans and all our close, extinct relatives. That fossil wasn’t enough to confirm Africa as our homeland. Since that discovery, paleoanthropologists have amassed many thousands of fossils, and the evidence over and over again has pointed to Africa as our place of origin. Genetic studies reinforce that story. African apes are indeed our closest living relatives, with chimpanzees more closely related to us than to gorillas. In fact, many scientists now include great apes in the hominid family, using the narrower term “hominin” to refer to humans and our extinct cousins. In a field with a reputation for bitter feuds and rivalries, the notion of humankind’s African origins unifies human evolution researchers. “I think everybody agrees and understands that Africa was very pivotal in the evolution of our species,” says Charles Musiba, a paleoanthropologist at the University of Colorado Denver.
9-15-21 We should isolate when we have flu, not just covid-19
SEVERAL years ago, when I was working at a hospital in health research, I caught one of the bugs that were invariably transmitted around the building. I decided against commuting in, but I wasn’t so unwell that I couldn’t work from home. My manager informed me, however, that the hospital had a policy: if you are too ill to come to work, you are too ill to work from home. While the reasoning for this rule is sound, its effects may have been dangerous: to avoid taking a sick day and falling behind on work, many people would have gone to their office, risking transmission. Many companies now have policies against going into workplaces when ill, but it has taken a global pandemic to highlight what should be a basic ethical norm: an individual should be responsible for reducing the risk of passing on the pathogens they catch. One of the lessons of the covid-19 pandemic is that public health is everyone’s responsibility – or it should be. People feel a lot of pressure to work regardless of how they feel. A 2021 report from the Chartered Institute of Personnel and Development found, for example, that 75 per cent of surveyed UK employees reported presenteeism – continuing to work when sick or injured – in the workplace over the preceding 12 months. Presenteeism has a long history, but it seems that not even a global pandemic can stop it. Laws in the UK and the US explicitly prohibit intentionally or recklessly infecting another person with diseases, including covid-19 and sexually transmitted infections. And yet many people continue to work and expose themselves to others when sick, without legal consequences. Should these countries consider prosecuting a majority of working adults for breaking the law? Or decide that this behaviour isn’t obviously reckless? Neither, of course, is palatable.
9-15-21 The microbial gunk that hardens on teeth is revealing our deep past
Plaque fossilises while we are still alive. Now, dental calculus is giving up the secrets of our ancient ancestors, from what they ate to how they interacted and evolved. IT IS the only part of your body that fossilises while you’re still alive,” says Tina Warinner at the Max Planck Institute for the Science of Human History in Jena, Germany. To see what she is describing, stand in front of a mirror and examine the rear surfaces of your lower front teeth. Depending on your dental hygiene, you will probably see a thin, yellowish-brown line where the enamel meets the gum. This is plaque, a living layer of microbes that grows on the surface of teeth – or, more accurately, on the surface of older layers of plaque. If it isn’t brushed or scraped off, plaque hardens as minerals dissolved in saliva precipitate out into it, killing the microbes and petrifying them into a stony substance called dental calculus or tartar. To you and me, this rock-hard excrescence might seem rather repulsive, but it has become a chewy topic of research among archaeologists. Where it was once considered mere gobshite to be scraped off and discarded, it is now recognised as a time capsule extraordinaire. “Dental calculus is a treasure trove of information,” says Katerina Guschanski at Uppsala University in Sweden. Over the past 20 years, it has revealed some surprising and often quirky details of the lives of our ancestors. But recent research is far more ambitious. “We spent a number of years trying to understand dental calculus and how to use it to really get at some deeper evolutionary questions,” says Warinner. That is now paying off, and dental calculus is throwing light on big questions about where humans came from and where we are going. Warinner isn’t exaggerating when she says plaque “fossilises” – the process is exactly like permineralisation, when minerals in groundwater penetrate a dead organism and precipitate out, turning it into a fossil. Unlike underground fossilisation, however, dental calculus forms very rapidly: plaque can be fully calcified in just two weeks. The speed at which it fossilises means it captures vast amounts of biological detail over a lifetime. The principal component is entombed denizens of the oral microbiome, the huge and diverse assemblage of bacteria, archaea and fungi that live in and around your mouth. They account for about 90 per cent of calculus by volume, says Guschanski. But it also traps other things, including bits of food, pathogens, an individual’s own DNA and environmental debris such as dust and smoke particles. In fact, anything that finds its way into your mouth can end up being trapped in calculus. People’s drug histories have been probed via dental calculus. It has even been proposed as a way of telling whether someone has had covid-19.
9-15-21 Scientists in Egypt identify fossil of prehistoric 4-legged whale
A fossil discovered 13 years ago in Egypt's Western Desert has been identified as a prehistoric whale believed to have roamed 43 million years ago that had four legs and could live both on land and sea. Paleontologist Hesham Sallam, a professor at Mansoura University in Egypt, told The Associated Press earlier this week that environmentalists stumbled upon the fossil in an area that during prehistoric times was underwater. Researchers didn't start examining the fossil until 2017, and they published their findings for the first time last month in the journal Proceedings of the Royal Society B. The fossil whale has been named Phiomicetus Anubis, after the ancient Egyptian god of death, and had an elongated skull and snout. "We chose the name Anubis because it had a strong and deadly bite," Sallam told AP. "It could kill any creature it crossed paths with."
9-15-21 Saudi Arabia camel carvings dated to prehistoric era
A series of camel sculptures carved into rock faces in Saudi Arabia are likely to be the oldest large-scale animal reliefs in the world, a study says. When the carvings were first discovered in 2018, researchers estimated they were created about 2,000 years ago. This was based on their similarity to reliefs at Jordan's famous ancient city of Petra. But a fresh study puts the camels at between 7,000-8,000 old. Precisely ageing rock sculptures is a challenge for researchers. Unlike cave paintings, say, there is often no organic matter to sample. Rock art of this size is also rare in the region. The researchers, who published their findings in the Journal of Archaeological Science, assessed erosion patterns, analysed tool marks, and tested animal bones found at the site to determine a new date for the sculptures' creation. Their age makes them even older than such ancient landmarks as Stonehenge (5,000 years old) or the Pyramids at Giza (4,500 years old). They even predate the domestication of camels, a catalyst for economic development in the region. At the time of their creation, Saudi Arabia looked very different, with plains of grass dotted with lakes rather than the deserts of today. It is not clear why the camel sculptures were created, but the researchers have suggested that they could have provided a meeting point for nomadic tribes. They also noted the difficulty of making such works thousands of years ago. Many of the reliefs are high above the ground, meaning their carvers would have had to build scaffolding to create them.
9-15-21 Asteroid that wiped out dinosaurs shaped fortunes of snakes
Snakes owe their success in part to the asteroid strike that wiped out the dinosaurs, according to a new study. The impact caused devastation, with most animals and plants dying out. But scientists say a handful of surviving snake species were able to thrive in a post-apocalyptic world by hiding underground and going long periods without food. The resilient reptiles then spread out across the globe, evolving into the 3,000 or more species known today. The dinosaurs famously died out when an asteroid hit the Earth 66 million years ago, triggering earthquakes, tsunamis and wildfires, followed by a decade of darkness when ash clouds blocked out the Sun. An estimated 76% of plants and animals disappeared. But snakes, like some mammals, birds, frogs and fishes, managed to cling on to life. "In this environment of the collapse of food chains, snakes are able to survive and thrive, and they are able to colonise new continents and interact with their environment in new ways," said lead researcher Dr Catherine Klein, who carried out the research at the University of Bath. "It's likely that without this asteroid impact, they wouldn't be where they are today." At the time the asteroid slammed into Mexico, snakes were much like the ones we are familiar with today: legless with stretchy jaws for swallowing prey. With food in short supply, their ability to manage without food for up to a year and to hunt in the gloom following the catastrophe was likely instrumental in their survival. The handful of snake species that prevailed were mainly those that lived underground or on the forest floor, and in freshwater. With little competition from other animals, they had a blank canvas to branch out along different evolutionary paths and across the world, colonising Asia for the first time. Over the course of time, snakes become bigger and more widespread, exploiting new habitats, and new prey. New groups appeared, including giant sea snakes up to 10 metres long.
9-14-21 Piles of animal dung reveal the location of an ancient Arabian oasis
Fossilised piles of faeces, called middens, have revealed that a desert valley in Yemen was once a tropical oasis, which may have lasted in the dry region because of human land management practices. Today, Wadi Sana is a dry, rocky desert. We knew that between 11,000 and 5000 years ago, the Arabian peninsula and Sahara desert were wetter than they are now, and some lake-bed deposits suggested that grasslands and trees may have grown elsewhere in the interior of the peninsula. To find out more, Sarah Ivory at Pennsylvania State University and her colleagues turned to the petrified faeces of rock hyraxes (Procavia capensis). These small herbivorous mammals are native to parts of Africa and the Arabian peninsula and, despite their rabbit-like appearance, are kin to elephants and sea cows. Hyraxes live in colonies, defecating and urinating in a communal latrine. Many generations of them may inhabit the same location, and the layers of their concentrated waste material petrify in the dry air, creating a time capsule of local habitats because pollen and plant material are preserved in the faeces. Some hyrax middens date back 50,000 years. “Few other archives of information about past environments exist in dry places,” says Ivory. The researchers collected 24 middens in Wadi Sana, using a chemical dating process on 17 of them. The team also extracted fossilised pollen from 14 of these and classified it using a microscope. The pollen record shows that between 6000 and 4700 years ago, Wadi Sana was home to abundant tropical woodlands totally unlike anything there today. The region harboured frankincense and olive trees, as well as buttontrees (Terminalia), which today mostly grow along the foggy coastline. Elsewhere in the region, ecosystems were drying out and turning to desert as the monsoons weakened. But Wadi Sana was something of an oasis, partially thanks to the buttontrees that draw moisture from the air and pump it into the ground, but also because of the humans that moved there.
9-14-21 Sharon Peacock interview: How we track down new coronavirus variants
Last December, the UK shocked the world with the announcement of a new variant of the SARS-CoV-2 coronavirus that seemed to spread faster than the original virus. That discovery was made possible by the COVID-19 Genomics UK Consortium, which had been sequencing viral samples to monitor the evolution of the virus. COG-UK, as it is known, is led by Sharon Peacock, who spoke to New Scientist about her research. What were you working on before the pandemic kicked off? I was working in Thailand in disease research until 2009. When I came back to the UK, it was clear to me that genome sequencing of bacteria and viruses was on the cusp of being accessible to scientists in general. So I invested in understanding sequencing and how to apply it. My first study was looking at how sequencing performed in an MRSA [superbug] outbreak on a paediatric intensive care unit. At what point did you start thinking about sequencing the coronavirus? I was having conversations about the need for sequencing in early March 2020. People knew the virus would change because that’s what happens. By about 15 March, 20 of us got together and said, how would we set up a national sequencing capability? And the answer was to throw a net over everybody who could do it and say, come and help us. So the public health agencies, Wellcome Sanger Institute and 16 sequencing hubs around the country did. We didn’t waste any time. Did everyone agree that sequencing Some people thought the virus wouldn’t change enough to make it useful. The virus changes quite slowly, there’s limited genetic diversity compared to some other pathogens. But we continued anyway. And when October 2020 came and [significant] variants started to emerge, that meant that we were in a very strong position compared to some countries that had to really scale up quite quickly.
9-13-21 Rare genetic variants play important role in people who live to be 100
A close look at the DNA of centenarians – people aged over 100 years old – has identified rare genetic variants that might help explain their longevity. “Rare variants in ageing pathways affect human lifespan and constitute a part of the genetic architecture of human longevity,” says Zhengdong Zhang at Albert Einstein College of Medicine in New York. “There is an interplay between common and rare variants. Together they affect longevity, and I think that’s also true for any complex human trait.” Zhang and his team compared the genetic profiles of 515 centenarians and 496 non-centenarians – who were aged between 70 and 95. The researchers wondered whether the centenarians might owe their longevity in part to an absence of rare genetic variants known to increase the risk of disease. But they found that these “pathogenic rare variants” were as likely to be carried by centenarians as non-centenarians. On the flip side, some rare versions of genes known to have a beneficial effect on health were more likely to be carried by centenarians than non-centenarians. For instance, the researchers found the centenarians carried rare beneficial variants in something called Wnt signalling – which has a known role in the onset of cancer. This knowledge could be used to develop anti-ageing drugs that can target ageing mechanisms in general rather than treating individual age-related conditions to extend human lifespans, says Zhang. “This paper is intriguing due to the considerable [sample size] … These investigations are in essence challenging because large numbers are required to find statistically significant signals,” says Morten Scheibye-Knudsen at the University of Copenhagen in Denmark. “These exciting findings highlight the importance of human genetics in longevity research.”
9-13-21 A new company is trying to bring back the woolly mammoth. Expect 'tons of trouble' along the way.
A new company announced Monday that it's aiming to genetically resurrect the woolly mammoth, an oft-talked about endeavor that some scientists think could help fight climate change. The goal is to turn frozen tundra in Siberia back into grasslands, which can serve as effective carbon sinks. But Colossal's plan will undoubtedly raise many questions about the ethics of bringing back the ancient giants from the dead. "There's tons of trouble everyone is going to encounter along the way," Beth Shapiro, a paleogeneticist at the University of California, Santa Cruz, told The New York Times. Some of the main concerns have to do with the fact that mammoths have been extinct for thousands of years. Therefore, scientists may not know enough about their behavior, which means the animals — if Colossal or some other entity is ever indeed successful at bringing them back, which is far from a given — could suffer. For example, at the beginning at least, the mammoths wouldn't have mothers, Heather Bushman, a philosopher at the London School of Economics, pointed out. And if the species was "anything like elephants," they would have had "extraordinarily strong infant-mother bonds that last for a very long time," she told the Times. That leaves Bushman wondering who will look after the mammoths once they're on the ground. Read more at The New York Times.
9-9-21 Tooth decay has been a problem for primates for 54 million years
We are likely to develop dental cavities over time because sugars in our carbohydrate-rich diet support oral bacteria that release demineralising acids. Now there is evidence that the problem goes back to the early days of primate evolution. Microsyops latidens, a prehistoric primate that lived during the Early Eocene about 54 million years ago, also had to deal with cavities. “I was going through the [fossil] sample and I kept noticing these holes in their teeth and I wondered what they were,” says Keegan Selig at the University of Toronto Scarborough in Canada. “It was surprising even to see cavities in these critters, and then to see just how frequent they were was very surprising. We didn’t expect that they would be so common compared to living primates.” Selig and his colleague Mary Silcox, also at the University of Toronto Scarborough, examined the fossilised teeth of 1030 individuals collected from the southern Bighorn basin in Wyoming. They found that 7.48 per cent of individuals had cavities, a higher frequency than seen in most current living primates with the exception of some capuchins and tamarins. The M. latidens teeth are the oldest known evidence of dental cavities in any mammal, according to Selig and Silcox. M. latidens probably had a taste for high-sugar foods such as fruit, which could have led to these cavities if they were eating a lot of them. “These critters obviously didn’t have dental floss or toothbrushes, so you’d expect the cavities to kind of form everywhere, but the cavities only formed on the main chewing surface of the tooth, which is surprising. We don’t really know why,” says Selig. The fossils came from slightly different levels in the ancient rock sequence and so provide evidence of the M. latidens population over an extended period, perhaps over thousands of years. At certain levels in the sequence, the incidence of cavities was even higher; at one level, 17 per cent of individuals were affected. This fluctuation could be explained by changes in diet, say the researchers.
9-9-21 Infants may laugh like some apes in their first months of life
As babies age, their laughter starts to sound more like that of human adults. Babies may laugh like some apes a few months after birth before transitioning to chuckling more like human adults, a new study finds. Laughter links humans to great apes, our evolutionary kin (SN: 6/4/09). Human adults tend to laugh while exhaling (SN: 6/10/15), but chimpanzees and bonobos mainly laugh in two ways. One is like panting, with sound produced on both in and out breaths, and the other has outbursts occurring on exhales, like human adults. Less is known about how human babies laugh. So Mariska Kret, a cognitive psychologist at Leiden University in the Netherlands, and colleagues scoured the internet for videos with laughing 3- to 18-month-olds, and asked 15 speech sound specialists and thousands of novices to judge the babies’ laughs. After evaluating dozens of short audio clips, experts and nonexperts alike found that younger infants laughed during inhalation and exhalation, while older infants laughed more on the exhale. That finding suggests that infants’ laughter becomes less apelike with age, the researchers report in the September Biology Letters. Humans start to laugh around 3 months of age, but early on, “it hasn’t reached its full potential,” Kret says. Both babies’ maturing vocal tracts and their social interactions may influence the development of the sounds, the researchers say. A second trial in the new study with different audio clips and a new group of 100 novices also found that older infants seemed to laugh mainly on exhales. And participants of both trials reported that the more adultlike laughs were more pleasing to hear and contagious. That second finding suggests that the shift in laughter as infants age may partly happen due to unconscious affirmations from the babies’ parents, Kret says. Laughs during exhalation are clearer and louder than during inhalation, she says, sending a stronger signal during interactions that may be better for bonding.
9-9-21 Blood test could reveal who is most likely to get severe covid-19
A simple blood test could help predict which people with covid-19 are likely to get severely ill and need to go on a ventilator. The test measures levels of antibodies in the blood that are directed against molecules released by dead blood cells, including their own DNA. The test may also prove helpful in infected people before they reach the stage of needing hospital treatment, says Ana Rodriguez at NYU Langone in New York. It is likely to be less accurate in that group, but it could indicate who needs closer monitoring, she says. People who get severely ill from covid-19 tend to deteriorate at least a week or more after symptoms begin, when virus levels are falling, suggesting it is something about the person’s reaction to the infection that causes their problems, rather than the virus itself. Rodriguez’s team looked at blood tests done on 115 people admitted to hospital with covid-19 in 2020. About half of these people became severely ill and needed oxygen support, while the rest recovered quickly. Those with high levels of antibodies directed against DNA or a fatty molecule from cell membranes called phosphatidylserine had about a 90 per cent chance of deteriorating. But the test only identified about a quarter of people who got worse. “It won’t mean we catch everybody but if you have this, it looks very bad,” says Rodriguez. It is unclear if the antibodies detected by the test are involved in the person’s deterioration, or if they are innocent bystanders. The DNA and phosphatidylserine seem to come from red blood cells that have burst open, as well as immune cells called neutrophils that release their DNA as they die in a bid to trap bacteria. It is possible that the antibodies may bind to the DNA, contributing to the formation of multiple tiny blood clots, which is often seen in severe covid-19 and causes strokes and kidney damage. Doctors currently make covid-19 treatment decisions based on people’s clinical signs, such as their blood oxygen levels, and their age and other risk factors.
9-8-21 What we know so far about booster shots and the covid-19 vaccines
AS A growing body of data suggests that vaccine-induced protection from covid-19 declines over time, many nations are gearing up to roll out a booster programme. Israel has already begun, while the US, France and Germany have all announced plans to begin rolling out third doses. Some other countries, including the UK, are holding back, with results from a key trial of third shots expected imminently. The Joint Committee on Vaccination and Immunisation, which advises UK health departments, has been mulling over booster shots for some time. In June, it issued interim advice that any potential booster scheme should be offered in two stages from September, starting with care home residents, front-line healthcare and social care workers, people aged over 70 and adults who are clinically extremely vulnerable or immunosuppressed. But this is largely yet to materialise: all that has been announced so far is a limited programme of third shots for people who have severely weakened immune systems. There has been speculation since early in the development of the coronavirus vaccines that booster doses would be needed, perhaps to combat newer variants. But time is also a factor. For many diseases, the strength of the immune response – stemming from either natural infections or vaccines – wanes over time periods ranging from months to years. Several studies have shown that, as expected, antibody levels fall gradually in the months after coronavirus vaccination. Antibodies aren’t the whole story, as the memory cells that make antibodies and other immune cells called T-cells can persist in various sites in the body, ready to spring into action if needed, but it is much harder to detect these in people via tests. However, we can measure how well vaccines are working in practice at stopping people from getting ill. Studies of covid-19 vaccination have given varying estimates of this. Recent Israeli data caused concern when it showed a person’s protection from infection could be as low as 40 per cent roughly six months after the nation’s vaccination programme began, although protection against severe disease seemed to be holding up, at 91 per cent.
9-8-21 mRNA cancer therapy now in human trials after shrinking mouse tumours
A cancer treatment that uses messenger RNA to launch an immune attack on cancer cells can completely shrink tumours in mice and is now being tested in people. Messenger RNAs – or mRNAs – are molecules that instruct cells to make proteins. They have risen to fame with the roll out of mRNA covid-19 vaccines. BioNTech, the German company that developed Pfizer’s mRNA covid-19 vaccine, is now testing whether mRNAs can be used to treat cancer by stimulating cells to produce tumour-fighting proteins. The company made a mixture of four mRNAs that instruct cells to produce four proteins called cytokines that are naturally released by immune cells to attack cancer cells. When they injected these mRNAs directly into melanomas in 20 mice, immune cells within the tumours began producing large amounts of the desired cytokines. This produced an immune response that caused the skin tumours to completely disappear in all but one of the mice in less than 40 days. In another experiment, mice that had melanomas as well as lung tumours were treated with the mRNA mixture. The mRNAs were only injected into the melanomas, but they also suppressed the growth of the lung tumours. This may be because the immune cells activated by the mRNAs were able migrate to the distant tumours, says Timothy Wagenaar at Sanofi, a pharmaceutical company that is partnering with BioNTech to develop the treatment. The mice didn’t display any side effects and didn’t lose weight during the treatment. Following these promising results, BioNTech and Sanofi are now testing the safety of the mRNA mixture in 231 people with advanced melanoma, breast cancer and other solid tumours. They presented preliminary results of the first 17 patients at the Society for Immunotherapy of Cancer annual meeting in November 2020, showing they had no serious side effects. Future trials will test how well the therapy works.
9-8-21 5 fruit and veg, 8 hours’ sleep: Should we trust daily health targets?
Many of us aim for “recommended dailies” such as 10,000 steps, 2000 calories or 2 minutes of tooth brushing. But where do these figures come from and are they supported by evidence? FOR as long as I can remember, certain numbers have inhabited my head: Five fruit and veg a day, 8 hours of sleep, 2000 calories, 2 minutes of tooth brushing, eight glasses of water, 10,000 steps. For want of a better term, these are the “recommended dailies”: numbers that are etched onto our brains as the ones we should live by. But for all their influence, it is unclear whether sticking dutifully to them actually makes a difference to our health. So I decided to get to the bottom of things, attempting to live my own life by the numbers (see “Living the dream”, page 41) while also digging into some critical questions about them: who came up with these figures in the first place? How solid is the scientific basis for these magic numbers? More to the point, is sticking to them really worth the effort? Keeping your teeth clean isn’t just a way to avoid the dentist’s drill (and bill) – the bacteria that cause gum disease have also been linked to an increased risk of developing Alzheimer’s. People with gum disease also have a two to three times greater risk of having a stroke or heart attack, and while a causal link hasn’t been shown, there are suggestions that gum disease increases markers of inflammation in the blood. The benefit of brushing is that as it removes thin films of plaque bacteria from the teeth, it breaks up bacterial communities, disrupting the opportunity for social evolution. This essentially stops them evolving into super bacteria that are experts at causing decay. Where the “rule” about brushing for 2 minutes, twice a day comes from isn’t clear (Public Health England is unsure of its origins, despite the recommendation appearing on National Health Service sites), and there is conflicting evidence on how much, and how often, is actually needed.
9-8-21 Recommended daily health targets can save us from ourselves
LIVING to a ripe old age owes a fair amount to luck, but if science can tell us anything about health, it is that our judgement matters, too. The way we live our lives and the way we treat our bodies can make a huge difference to our chances of having a long and healthy life. This is the basic message encoded in the generic health targets that we all carry in our heads: five pieces of fruit or veg a day, 8 hours of sleep, 10,000 steps, 2000 calories and so on. Yet on closer inspection, many of the best-known nuggets of health advice owe more to marketing and folklore than they do to science. The 10,000 steps per day that so many people aim to take seem to have been largely plucked from nowhere. Even dentists can’t tell you why they recommend brushing specifically for 2 minutes, twice a day, as our feature on page 38 reveals. To make matters worse, even advice that stems from decades of research comes from epidemiological studies, which follow large numbers of people over many years. Translating this kind of data into one-size-fits-all advice is notoriously difficult for the simple reason that we aren’t all the same. The number of hours you need to sleep for can vary by 7 hours depending on your age, for example. Then there is the ideal number of steps, which differs depending on whether you are hiking up the side of a mountain or ambling around a shopping mall. And since science’s work is never done, even solid health advice can, and does, change. With this much complexity, it is tempting to just ditch living by numbers. Yet targets do have a part to play in health education. Even though fewer than a third of UK adults actually manage to consume five portions of fruit and vegetables a day, the average child at primary school can recite the guideline, so at least has internalised the message that eating plants is good for you.
9-7-21 A pinch of saturated fat could make tempering chocolate a breeze
Phospholipids are key to achieving a melt-in-the-mouth texture. Glossy, velvety chocolate that snaps in the fingers and melts in the mouth is the chocolatier’s dream. But crafting cocoa confections with this optimal texture is no easy feat. The endeavor, known as tempering, demands carefully warming and cooling liquid chocolate until it crystallizes into its most delectable form. Now, scientists may have found a shortcut: adding a small pinch of fatty molecules called phospholipids, researchers report August 31 in Nature Communications. With phospholipids, “you can simplify the whole tempering process, making sure you always have the right quality of the chocolate,” says food chemist Alejandro Marangoni of the University of Guelph in Canada. Curious about what occurs on a molecular level during tempering, Marangoni and colleagues focused on the ingredient that gives chocolate its texture — cocoa butter. While previous tempering research had targeted cocoa butter’s main component, triglycerides, the team set its sights on a different sweet spot: the minor components, which include free fatty acids and phospholipids. Removing these minor components from the cocoa butter and adding them back in one by one allowed the researchers to figure out each component’s role during tempering. With just a pinch of phospholipids added to the cocoa butter — achieving a weight concentration of 0.1 percent of the chocolate’s total — the mixture rapidly crystallized into the elusive, melt-in-the-mouth texture. The process required a single cooling to 20° Celsius rather than multiple heating and cooling cycles as tempering typically demands. Next, the team increased the phospholipid weight concentration in melted dark chocolate by an extra 0.1 percent, and easily produced high-quality textures again. The result suggests that phospholipids could be used to simplify chocolate tempering.
9-6-21 Men fart more when eating a plant-based diet due to good gut bacteria
Plant-based diets cause men to fart more and have larger stools, researchers have found – but that seems to be a good thing, because it means these foods are promoting healthy gut bacteria. Anecdotally, it is well-known that eating more plants – including fruit, vegetables, grains and legumes – creates bulkier stools and increases flatulence. However, few studies have measured these changes or related them to changes in gut bacteria. Claudia Barber at the Liver and Digestive Diseases Networking Biomedical Research Centre in Barcelona, Spain, and her colleagues compared the effects of a Mediterranean-style diet mostly comprised of plants with a Western-style diet containing fewer fruit and vegetables on the guts of 18 healthy men aged between 18 and 38. Each participant was randomly assigned to follow one of the diets for two weeks, then after a break, they switched to the other diet for two weeks. The men did a similar number of poos per day on the two diets, but each one was about double the size while they were on the plant diet. The men collected and weighed their own stools using digital scales and found they produced about 200 grams per day on the plant diet, compared with 100 grams on the Western diet. This is because eating plants promotes certain types of bacteria in our guts that make food for themselves by fermenting plant fibre, says Rosemary Stanton at the University of New South Wales in Sydney, Australia. The added stool weight is made up of the spent bodies of these extra bacteria plus water and a small amount of undigested plant fibre, she says. Some of the specific fibre-fermenting bacteria that became more abundant in the men’s guts while they were on the plant diet included Agathobaculumand anaerostipes and Agathobaculum butyriciproducens, an analysis of their waste showed.
9-3-21 Mix-and-match antibiotic prescriptions may help lower resistance risk
Antibiotic resistance is one of the biggest threats to public health, yet a surprisingly simple tactic could help to tackle it: alternating between three different antibiotic medicines daily. The approach has so far only been tested on bacteria grown in a dish, but using this approach with commonly used antibiotics killed bacteria five times more efficiently than using one drug at a time. If trials in people give similar results, it could be used to combat antibiotic resistance by asking people to take a different drug out of three every day, says Hinrich Schulenburg at the University of Kiel in Germany. Antibiotics are seen as one of the greatest developments of modern medicine, transforming potential killers like wound infections and tuberculosis into something treatable with a course of tablets. But the potency of this group of medicines is waning, because bacteria can mutate to become resistant to their effects and new drugs are not being developed fast enough. There are global campaigns to try to husband our remaining antibiotics by reducing their use. Doctors already change to a different antibiotic if the bacteria causing an infection become resistant to the first drug used, typically after a few weeks. Schulenburg’s group wondered if a strategy of rapid switching from the outset would be helpful. The team showed in 2018 that if bacteria in a dish are treated with rapid switching between three antibiotics that work through different mechanisms, the microbes take longer to develop resistance than if the medicines are cycled over slower time-scales of a few weeks. The experiment used levels of antibiotics lower than normally given to people, to encourage resistance to develop. In the latest study they found the rapid-cycling approach was even more potent if they used three closely related antibiotics, from a class called beta-lactams. These are often used to treat Pseudomonas aeruginosa bacteria, which can cause wound infections and pneumonia.
9-3-21 How personalized brain organoids could help us demystify disorders
Clumps of brain cells made from people with Rett syndrome had abnormal electrical activity. Clumps of brain cells grown from the stem cells of two people with a neurological syndrome show signs of the disorder. The results, published August 23 in Nature Neuroscience, suggest that personalized brain organoids could be powerful tools to understand complex disorders. Researchers are eager to create brain organoids, human stem cells coaxed into becoming 3-D blobs of brain cells, because of their ability to mimic human brains in the lab (SN: 2/20/18). In the current study, researchers grew two kinds of brain organoids. One kind, grown from healthy people’s stem cells, produced complex electrical activity that echoed the brain waves a full-sized brain makes. These waves, created by the coordinated firing of many nerve cells, are part of how the brain keeps information moving (SN: 3/13/18). The researchers also grew organoids using cells from a 25-year-old woman and a 5-year-old girl with Rett syndrome, a developmental disorder marked by seizures, autism and developmental lags. Rett syndrome is thought to be caused by changes in a gene called MECP2, mutations that the lab-grown organoids carried as well. These organoids looked like those grown from healthy people, but behaved differently in some ways. Their nerve cells fired off signals that were too synchronized and less varied. Some of the brain waves these organoids produced are reminiscent of a brain having a seizure, in which a bolus of electrical activity scrambles normal brain business. With organoids carrying Rett syndrome mutations, scientists can better understand the syndrome and even begin to test possible treatments. Organoids might yield insights into other disorders, too, says coauthor Bennett Novitch, a developmental neuroscientist at the David Geffen School of Medicine at UCLA. “Work on this front is already under way in labs around the world.”
9-2-21 Rapidly evolving bits of DNA helped develop the human brain
Many of the fastest-evolving sections of the human genome are involved in brain development. These rapidly changing segments of DNA may have played key roles in the evolution of the human brain and in our cognitive abilities. Chris Walsh at Boston Children’s Hospital in Massachusetts and his colleagues studied sections of the human genome dubbed “human accelerated regions” (HARs). These stretches of DNA are virtually identical in many other mammals that have been studied, suggesting they have important functions – but they differ in humans, implying our evolution has changed them. Previous studies have identified 3171 possible HARs, but Walsh says it is unlikely that they are all important. “Probably hundreds of them are, but probably not thousands,” he says. His team set out to identify HARs that have played important roles in the evolution of our brains. The researchers placed copies of each HAR, as well as their chimpanzee equivalents, into developing brain cells from mice and humans. In each cell line, they tracked how much each gene in the genome was expressed. This allowed them to determine whether each HAR enhanced the activity of genes, compared with the equivalent sequence from a chimp. Using this and other methods, the team identified 210 HARs that significantly enhanced gene activity in the human neural cells. These HARs probably affect human brain development. The researchers then zeroed in on a gene called PPP1R17, which is expressed in some of the cells of the developing brain and regulated by several HARs, so it therefore behaves differently in humans than in other mammals. They compared the expression of PPP1R17 in the developing brains of mice, ferrets, rhesus macaques and humans. In the macaques and humans, the gene was expressed in the cerebral cortex, but it wasn’t in the mice and ferrets.
9-2-21 Stone Age humans or their relatives occasionally trekked through a green Arabia
Long-ago rains drew hominids in phases to what’s now dry desert. Arabia, known today for its desert landscape, served as a “green turnstile” for migrating Stone Age members of the human genus starting around 400,000 years ago, a new study finds. Monsoon rains periodically turned northern Arabia into a well-watered oasis, creating windows of opportunity for long-ago humans or their relatives to trek through that crossroads region from starting points in northern Africa and southwest Asia. That’s the implication of a series of five ancient lake beds of varying ages, each accompanied by distinctive stone tools, unearthed at a northern Saudi Arabian site called Khall Amayshan 4, or KAM 4. Sediments from the lake beds, which were linked to periods when the climate was wetter than today, also yielded fossils of hippos, wild cattle and other animals. Like hominids, those creatures must have migrated into the region along rain-fed lakes, wetlands and rivers, an international team reports online September 1 in Nature. Until now, the oldest stone tools in Arabia dated to at least 300,000 years ago (SN: 11/29/18). Previous finds only hinted that Stone Age Homo sapiens or other Homo species temporarily inhabited green, wetter parts of Arabia, a conclusion largely resting on discoveries at two other Saudi sites, each preserving stone tools from a single point in time (SN: 11/1/18). Aside from providing the earliest known evidence of hominids in Arabia, the new finds demonstrate for the first time that ancient Homo groups traveled there when conditions turned wet, say archaeologist Huw Groucutt of the Max Planck Institute for the Science of Human History in Jena, Germany, and colleagues. As a result, northern Arabia could have served as a key, if intermittent, passageway out of Africa for humans or close evolutionary relatives who reached South Asia by around 385,000 years ago (SN: 1/31/18), southern China between 120,000 and 80,000 years ago (SN: 10/14/15) and the Indonesian island of Sumatra between 73,000 and 63,000 years ago (SN: 8/9/17).
9-1-21 What would Earth be like if life had never existed?
Earth would be a very different place to our familiar home if life had never existed. The composition and chemistry of the atmosphere would be completely different, so this would profoundly affect the climate and the physical processes forming the land. If we were to visit such a place, we would surely find it a completely hostile and alien world on which we couldn’t survive. Although life began about 3.5 billion years ago, it largely remained single-celled and anaerobic for almost 2 billion years. When photosynthetic bacteria developed, they slowly changed the planet’s atmosphere from one comprised of mostly carbon dioxide and nitrogen with trace amounts of oxygen to a more oxygen-rich one. This oxygen assisted the development of the more complex eukaryotic cell and so the eventual rise of multicellular life. It also precipitated out iron oxides, forming all those red soils around the world. Without that oxygen, there would also be no ozone layer filtering out damaging UV radiation. With no life, the initial high levels of carbon dioxide would have remained in the atmosphere since no removal as marine carbonates could have occurred. So goodbye white cliffs of Dover in the UK and the limestone formations that make up our landscapes. Without life, Earth might be similar to Venus. There would be no oxygen, but abundant carbon dioxide, which could create a runaway greenhouse effect, evaporating the oceans. There would also probably be sulphur and nitrogen oxides in the atmosphere, resulting in sulphuric and nitric acid rain. Plate tectonics might stall without oceans, so there would be no mountain chains, just large volcanoes punching through a global crust of granite, erupting infrequently but catastrophically. The vast range of terrestrial rocks we know today, including slate, limestone, chalk and all other sedimentary rocks, would be absent.
9-1-21 Cartilage from the nose used to treat two people's knee osteoarthritis
Implants made from nose cartilage have been used to repair the knee joints of two people with severe osteoarthritis. A larger clinical trial is now planned to see if the treatment can help the millions of people with knee osteoarthritis worldwide. Knee osteoarthritis occurs when cartilage in the knee joint gradually wears away, leading to pain, stiffness and difficulty walking. It is common in the elderly, but some young people can develop it too. The only way to treat the condition is to replace the knee with an artificial joint made of metal or plastic. But these prosthetic joints can wear out too, leading to more surgery. Ivan Martin at the University of Basel in Switzerland and his colleagues wondered if another option may be to replace damaged knee cartilage with healthy cartilage taken from the nose. “The main target advantage is the effective regeneration of the cartilage, as opposed to substitution by a foreign body part,” he says. After successful experiments in mice and sheep, the researchers tried this in a 34-year-old man and a 36-year-old woman with severe knee osteoarthritis. First, they removed small amounts of cartilage from each person’s nasal septum – the structure separating the nostrils – and grew it in dishes to make thin, flat sheets. Surgeons then inserted these cartilage grafts into the man and the woman’s damaged knee joints. MRI scans showed that the nose cartilage successfully integrated into their joints. Eight months after the procedure, both reported significantly less pain, better knee function and quality of life. Both were able to avoid having traditional knee replacements. “A larger clinical test is a now a must to test efficacy, as the two cases treated can only provide anecdotal evidence,” says Martin.
9-1-21 The surprising upsides of spite and how to harness them
In an era of social media cancelling, our nasty side has never been more prominent. But the latest research suggests that, when wielded right, petty ill will can be a force for good. A MAN buys a house next door to his ex-wife and installs a 4-metre bronze statue of a hand, middle finger raised, facing her window. A prominent investor buys a company so he can fire the management he dislikes, even though he stands to lose money. People take their time at the checkout to annoy the next customer, buy gnomes for their garden to antagonise a neighbour and slow down to annoy tailgaters, even though it puts everyone in danger. Examples of spiteful behaviour, harming another at some cost to yourself, aren’t hard to find. As a psychological game where no one wins, spite is puzzling: we may wonder why it wasn’t weeded out by evolution long ago. Instead, in a competitive era of identity politics, all too often played out on social media, it seems more prevalent than ever. Yet, compared with other social behaviours like selfishness, cooperation and altruism, there has been relatively little psychological research into why we do it. With potentially far-reaching consequences for both political stability and individual mental health, it has never been more important to understand this dark side of human behaviour. For many years, most of the research into spite came from the field of behavioural economics: the study of how human decision-making differs from what you would expect from a purely rational point of view. Classical economists dreamed up the concept of Homo economicus, a person who only ever acts to maximise their own rewards. If offered a choice between something and nothing, Homo economicus would always take what is on offer. In experiments, however, this isn’t how everyone behaves. In the Ultimatum Game, created by economist Werner Güth at the University of Cologne in Germany in 1977, one volunteer is given a pot of money and asked to decide how much of it to share with another player. If the other player accepts the offer, both will keep their share of the cash. But if the other player refuses the offer, both leave empty-handed. They only play the game once.
9-1-21 The hard problem of consciousness is already beginning to dissolve
Science can solve the great mystery of consciousness – how physical matter gives rise to conscious experience – we just have to use the right approach, says neuroscientist Anil Seth. THE nature of consciousness is truly one of the great mysteries of the universe because, for each of us, consciousness is all there is. Without it, there is no world, no self, no interior and no exterior. There is nothing at all. The subjective nature of consciousness makes it difficult even to define. The closest we have to a consensus is that there is “something it is like to be conscious”. There is something it is like to be me or you, and probably something it is like to be a dolphin or a mouse. But there is – presumably – nothing it is like to be a bacterium or a toy robot. The challenge is to understand how and why this can be true. How do conscious experiences relate to the cells and molecules and atoms inside brains and bodies? Why should physical matter give rise to an inner life at all? Some people fear science may not be up to the task. They point out that you can’t precisely control or observe felt experiences. Some even question the idea that physical mechanisms can ever explain consciousness. I disagree. I believe that science is capable of explaining consciousness, but only if we stop treating it as a single big mystery requiring a humdinger solution. Instead, we must break it down into its various related properties and address each in turn. As we progressively explain why particular patterns of brain activity map to particular kinds of conscious experience, we will find that the deeper mystery of consciousness itself begins to fade away. Humans have pondered the relationship between physical matter and conscious experience for a long time. In the 1600s, René Descartes divided the universe into “mind stuff” (res cogitans) and “matter stuff” (res extensa), raising the conundrum of how the two might ever interact. His dualist perspective is now accompanied by a bewildering array of alternatives, ranging from illusionism – the proposal that consciousness doesn’t exist, at least not in the sense that we normally think of consciousness – to panpsychism, which posits that consciousness is fundamental and ubiquitous. The relatively orthodox scientific view of physicalism – the view that I find most appealing – is that consciousness is related to or emerges from physical matter. The question is how.
9-1-21 Perspective-changing experiences, good or bad, can lead to richer lives
Even people facing tough times can achieve a good life. In December, my husband, our 5-year-old daughter and I tested positive for COVID-19. Life, already off-kilter, lurched. Smell, taste, breath — were they normal? The air smelled only of cold; everything tasted vaguely of cardboard. The state mailed us a pulse oximeter to read oxygen levels from our fingers. The device beeped when those levels dipped too low — a seemingly objective measure during a subjective time. We used the device with abandon, only my husband regularly triggering the alarm. He went to bed, where he stayed for days, or maybe it was weeks. Time distilled into moments: remote school, meals, Christmas, pulse-ox, beep. We exited quarantine on January 1, the day of fresh starts. Except my once energetic 8-year-old son, who somehow never tested positive, now loafed in front of the heater for hours. My husband, his breathing still abnormal and his fatigue lingering, raged. Ever the extrovert, I absorbed their emotions as my own. My risk calculation shifted, as despair overshadowed the fear of disease. The sickness we had hid from for so long had found us anyway. Were we now immune? Should we proceed just as before? Prior to the sickness, I’d been researching pandemic fatigue, a term used to describe the boredom that can arise during a protracted crisis like the one we’re in now (SN Online: 2/15/21). “People prefer action to inaction,” social psychologist Erin Westgate of the University of Florida in Gainesville told me. For some, that compulsion toward the experiential runs deep, she and colleagues reported in 2014 in Science. When the researchers gave college students a choice between sitting idly in a quiet room or pushing a button to receive an electric shock, a startling number went for the shock. I have been seeking, and pushing, that button all my life. I’ve taught English in Japan, worked as a national park ranger and, following an unfortunate series of events, sold pineapples along a tourist highway in Hawaii in exchange for a tent over my head. Westgate’s recent work suggests that button pushing sorts often flourish in rich and aesthetic environs. I took heed. Against the dreary backdrop of being homebound in a global health crisis, I signed up for private pottery lessons, drawn viscerally to the idea of creating something from mud.