1-22-21 The COVID-19 pandemic made U.S. college students’ mental health even worse
Almost half of the students surveyed experienced high levels of emotional distress and worry. The ongoing coronavirus pandemic has caused the mental health of U.S. college students to plummet, a new study shows. Students most at risk of mental health challenges stemming from the pandemic include women, Asians, students under age 25, those in poor health, those who knew somebody with COVID-19 and lower-income students, researchers report January 7 in PLOS ONE. Even before the emergence of the novel coronavirus, U.S. college students struggled with depression, anxiety and other mental health disorders at higher rates than the general population. Many college students are grappling with a new social environment, struggling to figure out their careers and worrying about finances, says Matthew Browning, an environmental psychologist at Clemson University in South Carolina. To assess how the pandemic is impacting student mental health, Browning and colleagues surveyed more than 2,500 students from seven public universities across the United States last spring when the pandemic was ramping up. Study participants ranked statements about their emotional state, preoccupation with COVID-19, stress and time use. Based on total scores, researchers classified the students as having experienced high, moderate or low levels of emotional distress and worry. The researchers note that they did not use standardized screening tools for disorders such as anxiety and depression, but instead zoomed in on mental health stressors arising directly from the pandemic (SN: 3/29/20). About 85 percent of the students surveyed experienced high to moderate levels of distress, Browning’s team found — about 45 percent were highly impacted and about 40 percent were moderately impacted. Those who reported low levels of distress were more likely to be white and spend two or more hours outdoors.
1-22-21 Extroverts have more success training their dogs than introverts
Dogs with certain kinds of behavioural problems are more likely to show improvement during training if their owners are extroverts and open-minded. After comparing human personalities and the success of behavioural training, scientists have found that introversion, close-mindedness and even conscientiousness are linked to fewer changes in some types of undesirable dog behaviour, including aggression and fearfulness. The information could help veterinarians identify dog-owner pairs that might need more help during training, says Lauren Powell at the University of Pennsylvania School of Veterinary Medicine, who co-led the study. Over a six-month period, Powell and her colleagues followed 131 dogs and their owners attending training sessions with a University of Pennsylvania veterinarian, who performed an initial behaviour assessment of each dog. The dogs had various issues, such as aggression towards people or dogs, chasing cars or animals, general fearfulness, separation anxiety, excessive barking and fear of being touched. Owners underwent personality testing and provided information about their dogs through a global canine research database called C-BARQ. The researchers also used a survey to evaluate how attached each dog and owner were to one another. The most important factor affecting success was how bad the dog’s behaviour was to start with, Powell says. Those with the worst behaviour improved the most over six months – possibly because they had so much to gain from the training. Confirming previous studies, the group also noted that younger dogs improved more than older dogs, and that the stronger the pair’s attachment, the more successful the training was. However, their research also revealed that human personality plays a role in corrective training for some kinds of unwanted behaviour.
1-22-21 Strange fossil is the first to show an ammonite without its shell
Ammonites are among the most common marine fossils from the age of the dinosaurs, but no one has found one like this before. It shows one of the swimming marine molluscs without its distinctive spiral shell – offering a rare opportunity to study ammonite internal anatomy. On a first look, Christian Klug at the University of Zurich, Switzerland, and his colleagues struggled to make sense of the fossil. “I wasn’t very sure what was what,” he says. Although the researchers could instantly recognise the shield-shaped structure on the left as part of a Subplanites ammonite jaw, the rest was a jumbled mess. As a result, photos of the 150-million-year-old fossil from southern Germany languished on Klug’s computer for years. Eventually, one of his colleagues tried photographing the specimen under ultraviolet light to highlight some of its subtler features. Through comparison with the soft internal structures of nautilus, a still-living relative of ammonites, it became clearer that the fossil preserved almost the entire body of an ammonite shorn of its shell. “I recognised the oesophagus, then the stomach,” says Klug. “Next, I saw the coprolite [fossilised faeces] in its intestine, so that was clear as well. Then I identified the gills and last came the reproductive organs.” How the ammonite lost its shell is a mystery. A likely scenario is that it was a meal that got away. “A predator might have pulled the yummy soft parts out of the shell and then dropped it [by mistake] in a place where they could preserve,” says Klug. This could explain why the ammonite is missing its tentacles. Ammonites floated in open water, and predators seem to have found it easiest to attack by nibbling a hole in the rear of the shell and then yanking the animal out. The tentacles might have been ripped off in the process.
1-21-21 Low-carb diets seem to involve more calories than low-fat diets
People who follow a low-carb diet consume more calories on average than those who follow a low-fat diet, according to a new study, although both diets can result in similar levels of total weight loss. “There [are] benefits for both of these diets,” says Kevin Hall at the National Institute of Diabetes and Digestive and Kidney Diseases in Maryland. “It’s a lot more complicated than a lot of the diet gurus and folks would have you believe.” Hall and his colleagues studied 20 volunteers who were admitted to a clinic for the duration of the study. Ten were put on a plant-based, low-fat diet for two weeks and the other 10 were placed on an animal-based, ketogenic, low-carb diet. After two weeks on one diet, the participants were swapped to the other diet for a further two weeks. Participants were free to eat as much as they wanted from whichever diet they were on, and Hall and his team monitored their calorie intake as well as their weight, body fat and insulin levels after meals. On both diets, volunteers lost between 1 and 2 kilograms, on average, but people on the low-fat diet consumed fewer calories and lost body fat at a higher rate than people who followed the low-carb diet. However, those on the low-carb diet experienced less variability in blood sugar and insulin levels after meals. “It’s a mixed bag,” says Hall. “If you think that large swings in glucose and insulin are potentially harmful, then the ketogenic diet came out the winner,” he says. “But there are benefits to the low-fat diet – they lost a greater percentage of their weight coming from body fat.” “Maybe studies like this can help us distinguish between what diets are better targeted to different people,” says Hall. “If you think your insulin surges are particularly harmful, then the ketogenic diet might be for you. If you’re worried about triglyceride [a constituent of fat] levels in your blood going up too high after meals, then clearly the low-fat diet was better.”
1-21-21 How covid-19 could become as mild as a common cold
POLICY-MAKERS are scrabbling to contain the spread of the coronavirus, as more highly transmissible variants travel around the world. Yet the evolution of SARS-CoV-2 in this way comes as no surprise to virologists. In fact, it is probably just one step on a much longer evolutionary trajectory. In time, virologists predict, the virus will become more benign, following an evolutionary pathway previously taken by four other human coronaviruses that today cause nothing more than the “common cold”. How could this happen, and how will our actions play a part? Coronaviruses tend to evolve slowly compared with other RNA viruses because they proofread their genetic material as they replicate, so can filter out mutations. What’s more, SARS-CoV-2 isn’t currently under much pressure to change, says virologist Ralph Baric at the University of North Carolina at Chapel Hill. It is successfully colonising a new species – with an open banquet of hosts – and variants that spread faster are outcompeting others. But evolutionary pressures are starting to kick in. As the virus encounters increasing resistance from antibodies among people who have been infected or vaccinated, new mutations become more likely to take hold. Indeed, some experts suggest that the new variants we currently see arose inside the bodies of people with long-lasting infections. Lab studies back up this idea. “Some of these variants emerged in vitro when the virus was cultured for several days in the presence of convalescent plasma,” says Manuela Sironi, an evolutionary virologist at the Scientific Institute IRCCS Eugenio Medea in Italy. We don’t know exactly what mutations might increase the speed at which the virus can spread. SARS-CoV-2 has four main structural proteins, including the spike protein that sticks out from its surface and helps it attach to cells in the body, as well as non-structural proteins that hijack the machinery inside host cells.
1-21-21 The oldest known abrading tool was used around 350,000 years ago
Using a grinding or rubbing stone represented an early shift in stone-tool making. A round stone excavated at Israel’s Tabun Cave in the 1960s represents the oldest known grinding or rubbing tool, say researchers who scrutinized the 350,000-year-old find. The specimen marks a technological turn to manipulating objects with wide, flat stone surfaces, say Ron Shimelmitz, an archaeologist at the University of Haifa in Israel, and his colleagues. Up to that time, stone implements had featured thin points or sharp edges. Microscopic wear and polish on a worn section of the Tabun stone resulted from it having been ground or rubbed against relatively soft material, such as animal hides or plants, the scientists conclude in the January Journal of Human Evolution. Similar stones bearing signs of abrasion date to no more than around 200,000 years ago. Specific ways in which the Tabun stone was used remain a mystery. By around 50,000 years ago, though, human groups were using grinding stones to prepare plants and other foods, Shimelmitz says. The team compared microscopic damage on the Tabun stone to that produced in experiments with nine similar stones collected near the cave site. Archaeology students forcefully ran each of the nine stones back-and-forth for 20 minutes over different surfaces: hard basalt rock, wood of medium hardness or a soft deer hide. Those applied to deer hide displayed much in common with the business end of the ancient stone tool, including a wavy surface and clusters of shallow grooves. It’s unclear which evolutionary relatives of Homo sapiens — whose origins go back about 300,000 years (SN: 6/7/17) —made the Tabun tool, Shimelmitz says. Other innovations around the same time included regular fire use (SN: 4/2/12).
1-20-21 Genomic medicine is deeply biased towards white people
Lack of diversity in genome studies means that treatments derived from them are leaving people of colour behind. Changing that isn’t only about justice – it could also lead to new therapies that would otherwise go undiscovered. IF YOUR doctor suspects you might have type 2 diabetes, they will want to know your average blood sugar level, which typically means taking a glycated haemoglobin test. This method of diagnosis is recommended by the World Health Organization and used pretty much everywhere. The problem, as Deepti Gurdasani discovered in 2019, is that the test may not work for everyone. Gurdasani and her colleagues found that a gene variant present in almost a quarter of people with sub-Saharan African ancestry alters the levels of glycated haemoglobin in their blood independent of blood sugar. This suggests they will be more likely to be falsely diagnosed with diabetes, she says. Gurdasani’s discovery is just the latest in a growing list of medical injustices resulting from the fact that the vast majority of people who have had their DNA sequenced are of European descent. Again and again, people from under-represented backgrounds find that drugs and diagnostics based on research that makes connections between DNA and disease don’t work for them. The dearth of diversity in these studies also means that people in overlooked populations are more likely to get inaccurate results from tests that look at an individual’s genetic risk of developing a condition, excluding them from the much-vaunted promise of personalised medicine. All of which explains why researchers like Gurdasani, a geneticist at Queen Mary, University of London, are sequencing the DNA of thousands of people from under-represented populations around the world. This isn’t just about justice: increasing the diversity of genetic studies could also uncover novel genetic variants associated with disease, providing targets for treatments that would otherwise go undiscovered. “There’s this treasure trove of human genetic variation that could lead to a new understanding of human biology,” says Keolu Fox, an anthropologist and genome scientist at the University of California, San Diego. The challenge now is to make sure that in the rush to harness it, geneticists don’t exploit the very people they seek to include.
1-20-21 As the coronavirus mutates, we will need to adjust our approach to it
JUST one month ago, the world was already struggling to contain the spread of the coronavirus. Now the challenge has become even harder. The emergence of new variants with different properties has changed the rules of engagement. That the coronavirus should evolve isn’t surprising – this is what viruses do. Scientists have been sequencing the genome of the SARS-CoV-2 virus since it began spreading out of Wuhan in China, recording the mutations that naturally accumulate as more and more people become infected and pass it on. This virus evolves mercifully slowly. Until recently, the genetic changes we saw were of little consequence to us, but that has begun to change. Now the virus has picked up mutations that allow it to spread more easily and, in some cases, that could help it evade our immune system (see “How worried should we be about the new coronavirus variants?”). A faster-spreading virus leads to more infections, as has been seen in the UK and several other countries, and thus, inevitably, to more deaths. An “escape mutant” virus that can evade our immune response, meanwhile, has the potential to reinfect those who have already had covid-19. Such a variant might even lead to the need for tweaks to vaccines or new treatments (see “Can coronavirus variants reinfect people and evade the vaccines?”). The news of these new variants has coincided closely with the widespread and very welcome roll-out of vaccines against covid-19. These vaccines offer us a way out of the pandemic, but we already knew it would be a long road to vaccinating almost the entire adult population of the globe. The recent evolution of the virus shows us just how long and complicated that road could be. As we try to work out how best to counter these variants, and what tweaks may need to be made to our vaccines, there is really only one thing we know for certain: the only way to stop the virus from evolving is to stop it from spreading.
1-20-21 How worried should we be about the new coronavirus variants?
THE rise and spread of new variants of the coronavirus are seen as ushering in a dangerous new phase of the covid-19 pandemic. But from the virus’s perspective, nothing has changed. It is just doing what comes naturally to viruses: evolving. It is now well-established that SARS-CoV-2 is a coronavirus with a large and unusually stable RNA genome, but that doesn’t mean it doesn’t change at all. Unlike most other RNA viruses, which are among the most mutation-prone biological entities in the world, SARS-CoV-2’s genome changes very slowly. This is largely because it has a proofreading function that is efficient at eliminating errors during replication, a major source of the genetic variation that we call evolution. “There’s not masses of evolution occurring, this is a very slow-evolving virus,” says David Robertson at the MRC-University of Glasgow Centre for Virus Research in the UK. A project called Nextstrain, based at the Fred Hutchinson Cancer Research Center in Seattle, compiles all published viral genome sequences and plots them on a family tree. This shows the original virus, called Wuhan-Hu-1, diverging steadily as it spread around the world. The virus’s average mutation rate remains low and steady at about two mutations per lineage per month, but over time this has given rise to thousands of different lineages. For example, there are more than 4000 different versions of the spike protein that the virus uses to break into host cells and which is the target of most vaccines. Intriguingly, most of the mutations seem to be induced by the human immune system rather than by RNA replication errors. One arm of our innate immune system is a generalised antiviral weapon that introduces random errors into viral genomes in a bid to neutralise them. It doesn’t always succeed.
1-20-21 Why vaccinating everyone on the planet may still not wipe out covid-19
VACCINE roll-out in a growing number of countries should eventually allow life to return to normal, but it is unlikely that we will be able to eradicate the coronavirus that causes covid-19 altogether. “I don’t see that these vaccines will be eliminating SARS-CoV-2 any time in the coming years,” says Kingston Mills at Trinity College Dublin. Despite the many variants, the coronavirus mutates less than many other viruses. “It does not seem to be as mutable a virus as influenza,” says Mills. That means we shouldn’t need to update vaccines every year, although occasional tweaks might be required. Despite this, wiping out the virus will be really hard even if we manage to vaccinate most people. To stop a disease spreading, infected individuals must pass it on to less than one other person on average. Early in the pandemic, infected people were infecting around three others on average, leading to estimates that two out of three people, or 67 per cent, need to be immune to halt transmission. This is what we mean by herd immunity. Some people now think 70 to 90 per cent of the population may have to be immune to achieve this, especially with more transmissible variants. This could be hard to do. Some covid-19 vaccines don’t reach this level of effectiveness when it comes to preventing disease. What is more, it isn’t yet clear to what extent any of the vaccines prevent transmissible infections, as opposed to merely preventing symptoms, although this is still being investigated. A few vaccines, such as the one for whooping cough, prevent symptoms, but don’t block transmission, says Mills. This means that viruses – or bacteria in the case of whooping cough – can circulate largely undetected, popping up only when they spread to unvaccinated people and cause disease.
1-20-21 China and the US clash over mission to find source of the coronavirus
THE World Health Organization’s scientific mission to explore the origins of the coronavirus has only been under way for a few days, but has already been the subject of clashes between the US and China over the investigation’s access to people and evidence. The first of the 13 scientists arrived in Wuhan on 14 January, after visa issues delayed an original 5 January start date. Led by Peter Ben Embarek at the WHO, the team is currently in quarantine for 14 days in a hotel and talking with Chinese officials, including those at the Chinese Centre for Disease Control. Members of the mission have said they are having daily covid-19 tests and are being “treated very well”. The polite language contrasts with the verbal sparring between the US and Chinese governments in recent days. The US state department claimed last weekend that it had reason to believe several staff at the Wuhan Institute of Virology, which has been the subject of debunked claims it was the source of the SARS-CoV-2 virus, had covid-19-like symptoms in autumn 2019. The US government later called on China to give the WHO team access to samples from the Huanan wildlife market that might have had a role in the outbreak of the virus, as well as to allow interviews with caregivers, former patients and lab workers in Wuhan. China issued a rebuke on Monday, with Reuters reporting that Sun Yang of the China National Health Commission told the board of the WHO: “The virus origin studies are of a scientific nature. It needs coordination, cooperation. We must stop any political pressure.” Such interventions from the US won’t assist the scientific mission, says David Heymann at the London School of Hygiene & Tropical Medicine. “I don’t think that’s helpful at all. They [the WHO team] are the ones that should be making the decisions, and China is a sovereign country.”
1-20-21 Parental burnout is on the rise, says psychologist Moira Mikolajczak
Stress levels of burned-out parents can be higher than those of people in extreme pain, according to research by Moira Mikolajczak. She tells New Scientist why the pandemic has brought new urgency to her work. “A STATE of vital exhaustion.” This is a surprisingly poetic description of burnout by the World Health Organization. Burnout – severe exhaustion caused by uncontrolled chronic stress – is increasingly becoming the focus of health research. It was originally identified as a work-related phenomenon, but now a form that affects parents is coming under the spotlight. Any parent can relate to the fatigue associated with looking after a child. But for some parents, that tiredness can tip into harmful exhaustion, leaving them physically unwell and damaging their relationships with their children and partners. Moïra Mikolajczak at the Catholic University of Louvain (UCL) in Belgium has been at the forefront of research into parental burnout. Over the past five years, she and her colleagues have found that it isn’t something that just affects parents of ill children – it can affect any parent, although it is more likely to affect highly educated people who are perfectionists and put too much pressure on themselves. Since Mikolajczak began studying the phenomenon, the field has expanded. A consortium of researchers she launched a few years ago to investigate parental burnout now has 90 members. The advent of covid-19 lockdowns, which have led to many parents juggling childcare with homeworking, has made the research more relevant and the need to understand this condition more urgent, says Mikolajczak. She tells New Scientist which factors can tip parents over the edge and how all parents can help protect themselves from extreme exhaustion.
1-20-21 Water may be even more crucial to life than we thought
WATER is essential for life as we know it, but why? A new analysis may rewrite the idea that it is solely the medium in which the reactions that drive life occur, instead viewing it as an active participant. The findings offer clues to the role that water played in the beginning of life on Earth, suggesting it may have “selected” the chemicals that now form the basis of life. “While the importance of water in life is well known and appreciated, the involvement of water as the most reactive chemical participant in today’s biochemistry was not well appreciated,” says Moran Frenkel-Pinter at the Georgia Institute of Technology in Atlanta. Water is often viewed as the background in which all the other chemicals, such as DNA and protein, are dissolved – in other words, the stage on which the real business of life happens. To show how active water really is, Frenkel-Pinter and her colleagues turned to a database of biochemical reactions. Out of 6500 known reactions, around 40 per cent of them either made a molecule of water or destroyed one. That is a conservative estimate, says team member Loren Dean Williams, also at the Georgia Institute of Technology, because the precise mechanisms of many reactions aren’t known and may depend on water in subtle ways. The team also looked at the molecules produced during the life cycle of a well-studied bacterium called Escherichia coli. More than 99 per cent of these are water molecules, the team estimates. Each time an E. coli divides to form two new cells, every water molecule it contains is either transformed or drives a chemical reaction 3.7 times on average (Journal of Molecular Evolution, doi.org/fq3f). “I do think there is this tendency to view water as a background actor,” says Lena Vincent at the University of Wisconsin-Madison. The study “confirmed something that we already appreciated and suspected, but didn’t fully grasp the extent of”, she says.
1-19-21 Covid-19 news: One in 10 people in the UK had antibodies in December
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. Estimated one in 10 people in the UK had covid-19 antibodies in December. About one in 10 people in private households across the UK are estimated to have had antibodies against the coronavirus in their blood in December 2020, according to the latest results from an infection survey by the Office for National Statistics (ONS). The detection of antibodies in the blood is an indication of a previous infection, but doesn’t indicate exactly when that infection took place. In England, about one in eight people – equivalent to 5.4 million people – would have been expected to test positive for antibodies during the same period. This is an increase from about one in 11 people the previous month. Equivalent estimates for Wales, Scotland and Northern Ireland put the figures for December at one in 10, one in 11 and one in 13 people who would have been expected to test positive for coronavirus antibodies, respectively, although these estimates are based on smaller numbers of positive antibody tests. Deaths in care homes in England have reached their highest level since mid-May, according to the most recent figures reported to the Care Quality Commission. About 1260 deaths involving covid-19 were reported in care homes in England in the week up to 8 January, up from 824 the previous week. US president Donald Trump rescinded coronavirus-related travel bans on non-US citizens travelling to the US from Brazil and much of Europe, effective from 26 January. President-elect Joe Biden plans to reimpose the restrictions once in office, according to a spokesperson. Germany will extend its nationwide lockdown until 14 February, with most shops and schools to remain shut. People aged 40 and above in Israel can now get a covid-19 vaccine, its health ministry announced.
1-19-21 Stunning fossil suggests dinosaurs lured mates with smell and vision
A reconstruction of the only fossilised dinosaur cloaca in existence may help illuminate how the prehistoric animals mated. The cloaca is an all-purpose opening on the body of many animals – including lizards, turtles and birds – that is used for mating, laying eggs, urinating and defecating. In 2016, Jakob Vinther at the University of Bristol, UK, and his colleagues were assessing evidence of camouflage in the well-preserved skin of a metre-long horn-billed dinosaur called Psittacosaurus. They noticed that the animal also seemed to have a surprisingly intact cloaca. Vinther and his colleagues took the fossil, flattened by years of compacting, and turned it from a 2D pancake into a 3D digital model. The team then tried to compare the Psittacosaurus’s cloaca against those of other animals. Most birds, which evolved from dinosaurs, don’t have a penis and reproduce using “cloacal kissing”, im which cloacas touch. Vinther believes that Psittacosaurus didn’t do this. Its cloaca had two flaps of skin covering most of the cloacal vent, which gives it an appearance more like that of a crocodile’s cloaca rather than a bird’s. Male crocodiles have a penis that emerges from the cloaca and Vinther’s team suspects that Psittacosaurus did too. Vinther reckons the Psittacosaurus’s skin flaps could have hidden musk glands producing sexually attractive scents. The conclusions mirror those reached by another team that analysed the same Psittacosaurus fossil and posted their findings to a preprint server last year. The new analysis also shows that the cloaca contains large amounts of the pigment melanin. Vinther initially thought that the melanin was to protect against microbial infection. But the melanin is in the outer skin, rather than inside the body, “so it’s probably to make the cloaca stand out”, he says. Such visual signalling is unusual, says Vinther, who hypothesises that Psittacosaurus could have lured mates a little like a dog does, through a combination of vision and sniffing around the tail region.
1-15-21 We must start publishing ethnicity data for covid-19 vaccinations
The race to vaccinate as many people as possible against covid-19 is under way, but unless we track who receives the vaccine we won’t be able to ensure the benefits are spread equitably. Publishing ethnicity and other demographic data must become a priority. This will be vital for countries to ensure that those hit hardest by the pandemic don’t miss out on receiving life-saving vaccines. Detangling data to reveal patterns that may exist among subgroups of a population can be a powerful tool to address inequality. After all, you can’t fix a problem if you don’t know it’s there. Globally, breaking down covid-19 cases based on widely recorded demographic factors, such as age and sex, has been enormously helpful for our understanding of the disease. Knowing that the risk of severe disease rises with age, for instance, has helped inform government interventions. Countries in which information on race and ethnicity for cases was published early on during the pandemic, including the US, the UK and Norway, were among the first to reveal worrying trends of people from racial and ethnic minority groups being at increased risk from covid-19. Similar patterns have since been seen in other nations that have looked for them, such as Australia and Brazil. Collecting and publicising this kind of data can help drive governments to take action. Data published in the UK in April, which revealed that people from Black, Asian and minority ethnic (BAME) backgrounds were over-represented among critically ill covid-19 patients, prompted the UK government to launch an inquiry into the issue and led Public Health England to start recording covid-19 cases and deaths by ethnicity. In June, the UK government announced £4.3 million in funding for new research aiming to “explain and mitigate” the disparity. Many other European countries have traditionally shied away from breaking down data by race or ethnicity, due to concerns over discrimination and privacy. But in September last year, the European Union committed to investigating the obstacles to collecting such data across member states by the end of 2021.
1-15-21 Dinosaur found in Argentina may be largest land animal ever
Fossils of a gigantic dinosaur are emerging from the ground in Argentina after 98 million years – and the creature may be the largest land animal that scientists have ever found. The ancient bones are from a titanosaur. At one point, this group of long-necked “sauropod” dinosaurs lived across the world. Some of the last titanosaurs lived in South America, where they evolved into giants including Patagotitan, which is sometimes claimed to be the largest land animal ever to exist. The fossils unearthed by the team, which was led by researchers at Argentina’s National Scientific and Technical Research Council, belong to an animal “considered one of the largest sauropods ever found, probably exceeding Patagotitan in size”, according to the peer-reviewed paper. The team declined to comment on the discovery for this story. “It is one of the most complete colossal titanosaurs of that age, which considerably helps to understand the group’s evolution,” says Aline Ghilardi at the Federal University of Rio Grande do Norte in Brazil, who studies titanosaur parasites and wasn’t involved in this study. Excavations in the province of Neuquén in Argentina are ongoing. So far, the team has unearthed 24 vertebrae, as well as some pelvis bones. Some of the bones have been excavated, while others have only been detected. According to the paper, the researchers aren’t sure which species the bones might belong to. However, they state that there are “clear differences” between these bones and those of previously unearthed dinosaurs in the region, including Patagotitan. This suggests that the fossils could be evidence of an unknown titanosaur. Ghilardi is cautious about the claim that the dinosaur might be larger than Patagotitan, noting that several recent discoveries have been called the largest titanosaur ever found only for the statements to be revised after further analysis. “But it is undoubtedly a huge animal, among the largest ever discovered,” she says, adding that she is excited to see if ongoing excavations unearth more bones to improve the accuracy of body size estimates.
1-15-21 Could delaying a second vaccine dose lead to more dangerous coronavirus strains?
Some experts worry the strategy could spur the virus to evolve in harmful ways. Spiking COVID-19 cases, slow vaccine rollout and the emergence of more transmissible coronavirus variants in some countries have sparked debate among scientists over the best way to protect people with recently authorized vaccines. One idea involves delaying when people receive the second of two required vaccine doses, so that more people can receive the doses that are currently available. That’s happening in the United Kingdom, where researchers have raised concerns about a new coronavirus variant that appears to be more contagious than other versions. Officials there are opting to extend the time between each vaccine dose from three or four weeks to up to three months (SN: 12/22/20). In the United States, on the other hand, officials strongly recommend that states stick to the regimen that the U.S. Food and Drug Administration authorized in December — two shots spaced three weeks apart for Pfizer-BioNTech’s vaccine and four weeks apart for Moderna’s. On January 12, the Trump administration announced it was no longer holding back second shots of COVID-19 vaccines, several days after President-elect Joe Biden suggested he would release all the shots. While that may speed protection for more Americans, it also raises the possibility that people might not get their second doses on time, if manufacturing problems arise. The possibility that second doses could be delayed has some experts concerned because it might lead to millions of people walking around with only partial immunity to the coronavirus, a condition that could be ripe for harmful mutations of the virus to arise. Delaying the second shot is a gamble, says Ramón Lorenzo-Redondo, a virologist at Northwestern University Feinberg School of Medicine in Chicago, particularly without a lot of evidence suggesting how well one dose works. Officials “shouldn’t gamble [their] best tools” to fight the pandemic, he says. “We don’t want to fuel [potential viral evolution] by doing suboptimal immunization of the population.”
1-14-21 Indonesia: Archaeologists find world's oldest animal cave painting
Archaeologists have discovered the world's oldest known animal cave painting in Indonesia - a wild pig - believed to be drawn 45,500 years ago. Painted using dark red ochre pigment, the life-sized picture of the Sulawesi warty pig appears to be part of a narrative scene. The picture was found in the Leang Tedongnge cave in a remote valley on the island of Sulawesi. It provides the earliest evidence of human settlement of the region. "The people who made it were fully modern, they were just like us, they had all of the capacity and the tools to do any painting that they liked," said Maxime Aubert, the co-author of the report published in Science Advances journal. A dating specialist, Mr Aubert had identified a calcite deposit that had formed on top of the painting, and used Uranium-series isotope dating to determine that the deposit was 45,500 years old. This makes the artwork at least that old. "But it could be much older because the dating that we're using only dates the calcite on top of it," he added. The report says that the painting, which measures 136cm by 54cm (53in by 21in), depicts a pig with horn-like facial warts characteristic of adult males of the species. There are two hand prints above the back of the pig, which also appears to be facing two other pigs that are only partially preserved. Co-author Adam Brumm said: "The pig appears to be observing a fight or social interaction between two other warty pigs." To make the hand prints, the artists would have had to place their hands on a surface before spitting pigment over it, the researchers said. The team hopes to be able to extract DNA samples from the residual saliva as well. The painting may be the world's oldest art depicting a figure, but it is not the oldest human-produced art. In South Africa, a hashtag-like doodle created 73,000 years ago is believed to be the oldest known drawing.
1-14-21 One of the oldest known cave paintings has been found in Indonesia
Pig art on the island of Sulawesi dates to at least 45,500 years ago. Inside a cave on the Indonesian island of Sulawesi, scientists have found one of the oldest known artistic depictions of a real-world object or organism. It’s a painting of a warty pig, an animal still found on Sulawesi, that was rendered on the cave’s back wall at least 45,500 years ago, researchers report January 13 in Science Advances. The discovery adds to evidence that “the first modern human cave art traditions did not emerge in Ice Age Europe, as long supposed, but perhaps earlier in Asia or even in Africa, where our species evolved,” says study author Adam Brumm, an archaeologist at Griffith University in Brisbane, Australia. At least two, and possibly three, other partially preserved pig paintings appear on the cave wall near the newly dated figure. All of the painted pigs in the Sulawesi cave appear to be confronting each other in a scene of some sort, says archaeologist Iain Davidson of the University of New England in Armidale, Australia. Similarly positioned, painted animals dating to roughly 30,000 years ago or more appear in scenes in France’s Chauvet Cave, says Davidson, who did not participate in the new study. On the ceiling of a small chamber in another Sulawesi cave, the researchers found a large pig painting — like the others, executed in red or dark red and purple mineral pigments — that dates to between 32,000 and 73,400 years ago. At least two other poorly preserved paintings of unidentified animals are located on the chamber’s ceiling and wall. The team considers it likely that Homo sapiens, rather than a closely related species such as Homo floresiensis (SN: 6/8/16), painted on the Sulawesi cave walls. Like a painted hunting scene from at least 43,900 years ago previously found in a separate Sulawesi cave (SN: 12/11/19), minimum age estimates for the pig paintings are based on measures of radioactive uranium’s decay in cauliflower-like mineral growths that formed in thin layers over and underneath parts of the depictions.
1-13-21 World’s oldest painting of animals discovered in an Indonesian cave
Stunning cave paintings discovered in Indonesia include what might be the oldest known depictions of animals on the planet, dating back at least 45,000 years. The paintings of three pigs, alongside several hand stencils, were discovered in the limestone cave of Leang Tedongnge on the Indonesian island of Sulawesi. Even local people were unaware of the cave sites’ existence until their discovery in 2017 by Adam Brumm at Griffith University, Australia, and his team. “I was struck dumb,” says Brumm. “It’s one of the most spectacular and well-preserved figurative animal paintings known from the whole region and it just immediately blew me away.” Sulawesi is known to contain some of the world’s oldest cave art, but the new paintings may predate all other examples so far discovered on the island. Brumm and his colleagues used a technique called uranium-series dating to analyse a mineral formation that overlapped part of the image, and that must have formed after the cave art was produced. The mineral formation is at least 45,500 years old, suggesting the artwork itself could be much older. “It adds to the evidence that the first modern human cave art traditions did not arise in ice age Europe, as long assumed, but at an earlier point in the human journey,” says Brumm. Each of the three pigs is more than a metre long. The images were all painted using a red ochre pigment. They appear to be Sulawesi warty pigs (Sus celebensis), a short-legged wild boar that is endemic to the island and is characterised by its distinctive facial warts. “This species was of great importance to early hunter-gatherers in Sulawesi,” says Brumm. These pigs appear in younger cave art across the region, and archaeological digs show that they were the most commonly hunted game species on Sulawesi for thousands of years. “The frequent portrayal of these wild pigs in art offers hints at a long-term human interest in the behavioural ecology of this local species, and perhaps its spiritual values in the hunting culture,” says Brumm.
1-13-21 To improve our response to crises like covid-19 we must think smarter
“It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity…” We are just a couple of weeks into 2021 and yet that famous opening from Charles Dickens’s A Tale of Two Cities has never rung truer. On the one hand, we are seeing the roll-out of effective vaccines against a disease that little more than a year ago was unknown to science – a stunning tribute to human wisdom, and to the power of a belief in science. On the other hand, we have the incredible scenes of an enraged mob rampaging through the US Capitol, the fulcrum of what until recently was considered one of the most secure democracies on Earth. Will wisdom or rage set our trajectory for the coming months and years? It is perhaps too early to say, but what is clear is that the covid-19 vaccines give us grounds for hope that some form of normality will return in 2021, despite all the questions still swirling around how exactly that can best be achieved (see “Is the UK right to delay the second dose of the covid-19 vaccines?”). What is equally clear, however, is that if and when covid-19 is contained, business as usual isn’t an option. The pandemic has ruthlessly exposed the divisions, inequalities and structural weaknesses of societies around the world, not least in established Western liberal democracies such as the US and UK. Meanwhile, global problems such as climate change haven’t gone away – 2020, we now know, was the joint hottest year on record (see “Climate change: 2020 was the joint hottest year on record”). To see how best to move on, we would perhaps be wise to ask ourselves how we got here. Human development researcher Robert J. Sternberg makes the case that at least part of the problem lies in our faulty conceptions of what it means to be smart. Prioritising and rewarding a very limited idea of intelligence has exacerbated social, economic and racial inequalities, while fostering a “me first” culture that leaves us ill-equipped for the collaborative problem-solving we need if we are to survive and thrive as a species.
1-13-21 CRISPR gene-editing urgently needs an off-switch – now we have one
Making changes to genes with CRISPR has the potential to cure diseases and feed the world, if we can learn to control it. Now it looks like viruses hold the solution. THERE is a technology that could tackle some of life’s most pressing problems, from disease to malnutrition. It could fix medical conditions such as cystic fibrosis and sickle cell anaemia simply by changing a bit of genetic code. It could eliminate malaria by making male mosquitoes infertile. It could wipe out pests that destroy crops. And it could modify other organisms to increase their usefulness, helping to create foods that are tastier and more nutritious. This is the promise of CRISPR, a biochemical tool at the forefront of a gene-editing revolution. Produced naturally by bacteria, CRISPR has gained rock-star status among scientists in the decade since its extraordinary potential was first recognised, and it is already starting to live up to the promise. But behind all the excitement lurk some dark questions. What if the editing goes wrong? What if it has undesired effects? What if we can’t stop it? Without a means to keep CRISPR on target and halt it in its tracks when needed, gene editing could have disastrous consequences – both for human health and for the planet. What we need is an off-switch, one that can be used at will. Researchers around the world have spent years trying to find one, largely by investigating various biochemical solutions. However, it turns out that the answer may be right under our noses. In an evolutionary face-off between CRISPR-producing bacteria and the viruses that infect them, nature has already designed anti-CRISPR. The challenge now is to harness this evolved off-switch to our own ends and usher in the golden age that gene editing promises. Viruses, such as the one that causes covid-19, don’t just pose a threat to humans – they attack all living organisms, including bacteria. In the ancient bacteria-virus rivalry, CRISPR is one of the weapons bacteria have evolved to combat bacteriophages, the name given to viruses that infect them (see “Evolutionary arms race”).
1-13-21 We’ve got intelligence all wrong – and that’s endangering our future
A narrow focus on IQ to determine success is depriving us of key decision-making smarts, as our faltering response to problems such as covid-19 and climate change shows. IMAGINE a world in which admission to the top universities – to Oxford or Cambridge, or to Harvard or Yale – were limited to people who were very tall. Very soon, tall people would conclude that it is the natural order of things for the taller to succeed and the shorter to fail. This is the world we live in. Not with taller and smaller people (although taller people often are at an advantage). But there is one measure by which, in many places, we tend to decide who has access to the best opportunities and a seat at the top decision-making tables: what we call intelligence. After all, someone blessed with intelligence has, by definition, what it takes – don’t they? We have things exactly the wrong way round. The lesson of research by myself and many others over decades is that, through historical accident, we have developed a conception of intelligence that is narrow, questionably scientific, self-serving and ultimately self-defeating. We see the consequences in the faltering response of many nations to the covid-19 pandemic, and a host of other problems such as climate change, increasing income disparities and air and water pollution. In many spheres, our ways of thinking about and nurturing intelligence haven’t brokered intelligent solutions to real-world problems. We need a better way. Fortunately, at least the starting point for this is clear. By returning to a more scientifically grounded idea of intelligence, who can have it and how we set about cultivating it in ourselves and others, we can begin to reboot our decision-making smarts and reshape our world for the better. Our conception of intelligence has come both a long way and not very far in the past century or so. Historically, intelligence has been defined simply as an ability to adapt to the environment. People who are intelligent can learn, reason, solve problems and make decisions that fit their real-life circumstances.
1-13-21 You can boost a vaccine's effect with good moods and good friends
THE UK’s race to vaccinate 13.9 million people in high-priority groups against covid-19 by 15 February is a Herculean undertaking. “Unprecedented” may have become an overused word in the pandemic, but the size and speed of the vaccine roll-out warrants it, though it may still be months before many people receive a covid-19 vaccine. The numbers tell the story. Figures released on 11 January showed that nearly 2.3 million people in the UK have had a first dose of one of the three vaccines approved by the UK regulator. On that same day, the UK government said it aims to be vaccinating at least 2 million people a week in England by the end of this month. To reach the mid-February UK target that prime minister Boris Johnson announced on 4 January, 300,000 doses need to be given a day, roughly the rate doses were administered weekly at the end of December and start of January. “This is the biggest vaccine programme ever that the UK has had to roll out. It’s definitely new territory,” says Doug Brown at the British Society for Immunology. The biggest previous vaccination effort in the UK, for the flu, normally sees around 9 million people a year vaccinated. That happens over five months starting in September, with 60,000 doses a day on average, peaking at about 150,000 a day in late October. And there are key differences between flu vaccines and covid-19 ones, says Nilay Shah at Imperial College London. The big one is that flu vaccine manufacturers, and the regulators who then do quality control on the batches of vaccines after they are made, have about five months to build up huge stocks before they are used. By contrast, covid-19 vaccine makers are still in the start-up phase. Mass production of the active ingredients inside the vaccines has been under way for months, but companies don’t start putting doses into vials until closer to regulatory approval.
1-13-21 Lying makes us mimic the body language of the people we are talking to
When telling a lie, people may imitate the body language of the person they are lying to without realising they are doing it. The discovery might eventually lead to a new form of lie detection test. “Liars often deliberately change their behaviour into a way they think truth-tellers behave, but this particular copycat behaviour is something they wouldn’t even try to manipulate because they don’t realise they’re doing it,” says Sophie van der Zee at Erasmus University Rotterdam in the Netherlands. “And that could make it an interesting cue for detecting deceit.” Van der Zee and her colleagues asked about 50 university students to solve a supposedly simple wooden puzzle within 5 minutes. In reality, the puzzle was far too hard to solve in the time available. Van der Zee “hid” the puzzle solutions in the room where the students could find them, which encouraged the students to cheat. She then asked the students not to tell her supervisor that she had “accidentally” left the solutions in the room because she feared professional consequences. Van der Zee and her colleagues then recorded interviews as each student told another student about the puzzle challenge – which, if they were complying with van der Zee’s request, involved lying about how they solved the puzzle. Using a wireless accelerometer (a WiTilt), van der Zee’s team recorded the head, chest and wrist movements of the students – both the ones talking about the puzzle and the ones listening. They found that when a student was telling the truth, their body movements differed from those of the person asking questions. But when they were lying, the movements of the two speakers tended to align. This may be because lying requires so much concentration, says van der Zee, so speakers might subconsciously slip into mimicking their listener’s subtlest body movements because copying requires less thinking than coming up with their own body language. This way of coping with “cognitive overload” isn’t obvious to the naked eye, but was detectable with the accelerometers.
1-13-21 Newborn megalodon sharks were larger than most adult humans
Fossilized backbone suggests that the ancient predators were about 2 meters long at birth. “Baby shark” has taken on a whole new meaning. Newborn megalodon sharks were supersized fish larger than most adult humans, a new study suggests. An analysis of the growth rates of the ancient ocean predators, which lived between about 23 million and 2.5 million years ago, estimates that the sharks started life at about 2 meters long, researchers report January 11 in Historical Biology. Otodus megalodon is right up there with Tyrannosaurus rex in the pantheon of scary extinct predators, but little is actually known about the shark’s biology (SN: 8/10/18). Its skeleton was made of difficult-to-fossilize cartilage, so what scientists do know mostly comes from fossilized teeth. For example, paleobiologist Kenshu Shimada of DePaul University in Chicago and colleagues previously used megalodon teeth, as well as those of other ancient and modern sharks, to estimate a total adult body length for the fish of at least 14 meters (SN: 10/5/20). In the new study, Shimada and colleagues had an extra, rare piece of evidence: megalodon vertebrae. Although shark skeletons are made of cartilage, the animals’ backbones can become hardened and strengthened by deposits of calcium salts, which can then be fossilized. These vertebrae also preserve annual growth bands, like the rings of a tree, showing how the fish grew. The researchers used an imaging technique called micro-computed tomography to study three well-preserved vertebrae from one shark. Those images revealed 46 growth bands, suggesting that this shark lived to the ripe old age of 46. The creature is estimated to have been about 9 meters long at its death, and the size of the bands hints that the animal grew at a rate of about 16 centimeters each year. That means that the shark would have been about 2 meters long at birth — large enough for even a newborn to be a fearsome foe in the seas, the scientists conclude.
1-13-21 Is the UK right to delay the second dose of the covid-19 vaccines?
IN A bid to vaccinate as many people as fast as possible, the UK is taking an unorthodox strategy against covid-19. The country is eking out its vaccine supply by making most people wait three months to get their second dose of the two-shot regimen. Both vaccines currently being used in the UK were intended to be given over much shorter timescales. Changing a medicine’s dosing schedule so dramatically is unprecedented, and some experts have branded it a dangerous gamble, putting lives at risk. But what does the evidence say? The UK announced its approach on 30 December as it was battling a huge surge in covid-19 cases, partly driven by a new, more transmissible variant of the virus. This was the same day that the vaccine developed by the University of Oxford and AstraZeneca was approved, and it was immediately put on a timescale of up to 12 weeks between doses. The UK government also announced that the interval between doses of the vaccine developed by firms Pfizer and BioNTech would be stretched to the same duration. By then, more than 600,000 people had already been given their first injection since the immunisation drive began on 8 December. Many scientists were shocked by the move because it deviates from the dosing schedules intended in the vaccine trials: three weeks for the Pfizer/BioNTech vaccine and four weeks for the one from Oxford/AstraZeneca. “A trial tells you that something works, so why would you change that?” says Stephen Griffin at the University of Leeds, UK. The approach makes most sense for the Oxford/AstraZeneca vaccine because its trial results hint that it works better with a longer wait between the doses. Some people in the trials ended up getting their second shot up to 12 weeks after the first, and the vaccine’s effectiveness at preventing symptoms was 65 per cent in this group, compared with 53 per cent in the rest.
1-12-21 UK government won’t say if it has ethnicity data for covid-19 shots
The body responsible for health in England has not revealed whether it is recording the ethnicity of people vaccinated against covid-19, despite calls from scientists for the release of more data on the ongoing roll-out of covid-19 vaccines. While it may still be too early to make conclusions from such figures, collecting and publishing them as vaccines are being rolled out could help monitor vaccine uptake across different communities and inform efforts to ensure equitable access, says Naveed Sattar at the University of Glasgow, UK. In particular, there have been reports in the UK of increased vaccine hesitancy among people from Black, Asian and minority ethnic (BAME) backgrounds, who have also been found to be at an increased risk from covid-19. “Currently, the only publicly available data published is on the dashboard,” the Department of Health and Social Care, the UK government department that oversees health in England, said in an email to New Scientist. These figures include the number of people vaccinated so far, but there is limited information available about the demographics of those who have had a shot. A UK-wide survey by the Royal Society for Public Health last year found that only 57 per cent of respondents from BAME groups said they were likely to accept a covid-19 vaccine, compared with 76 per cent for the general population and 79 per cent for white respondents. “There’s a greater susceptibility to severe disease in these [BAME] groups and therefore there’s an even greater need to make sure that they get vaccinated,” says Sattar. “If there’s early-warning signals that there’s less uptake [among BAME groups], then that really means that something needs to be done.” Members of Independent SAGE – an independent group of scientists publishing advice on covid-19 for the UK government – have also called for the government to publish more data on its covid-19 vaccination roll-out. In addition to monitoring the numbers of people getting vaccinated, it is also important to gather other demographic information, such as age, ethnicity and deprivation, said Christina Pagel at University College London, during an Independent SAGE briefing on 8 January.
1-12-21 Covid vaccine differences? Pfizer v Oxford v Moderna
The three Covid-19 vaccines are from Pfizer-BioNTech, the University of Oxford and Astra-Zeneca and Moderna. The Pfizer, Oxford and Moderna vaccines each require two doses and you are not fully vaccinated until a week after your second shot. But there are many differences between them. BBC health correspondent Laura Foster looks at how much immunity they give, how they prevent infection and which one is better.
1-11-21 CRISPR gene editing used to store data in DNA inside living cells
DNA inside living bacterial cells has been edited with CRISPR technology to encode and store information. This could be a step towards developing a new medium for long-term data storage. Life’s genetic information is stored in DNA, but there is growing interest in using DNA as a storage medium for other kinds of data. To do this, information is often encoded using the four DNA bases – adenine (A), cytosine (C), thymine (T) and guanine (G). The corresponding DNA sequence can then be chemically synthesised in a laboratory, and even stored within everyday objects. Harris Wang at Columbia University in New York and his team took this one step further, using a form of CRISPR gene editing to insert specific DNA sequences that encode binary data – the 1s and 0s that computers use to store data – into bacterial cells. By assigning different arrangements of these DNA sequences to different letters of the English alphabet, the researchers were able to encode the 12-byte text message “hello world!” into DNA inside E. coli cells. Wang and his team were subsequently able to decode the message by extracting and sequencing the bacterial DNA. “This field is progressing exponentially and this paper is a great example,” says George Church at the University of Harvard, who wasn’t involved with the work. Wang thinks DNA inside living cells could be a more stable medium for long-term storage in unpredictable conditions. Whereas DNA kept outside cells can be degraded, bacteria have the ability to adapt to changing surroundings and can survive under harsh conditions. “What you’re offering by putting it inside the cell is that the DNA is protected by the cell and the machinery that the cell has to protect its DNA,” says Wang. “This can be very interesting for long-term storage,” says Thomas Heinis at Imperial College London. But as bacteria adapt and change, their DNA changes too – and these changes could affect the encoded information, says Heinis. “There are many sources of errors, one major source being mutations in the DNA during cell replication,” he says.
1-11-21 The UK may struggle to hit its covid-19 vaccine target – here's why
The UK’s race to vaccinate 13.9 million people in high-priority groups against covid-19 by 15 February is a Herculean undertaking. “Unprecedented” may have become an overused word in the pandemic, but the size and speed of the vaccine roll-out warrants it, though it may still be months before many people receive a covid-19 vaccine. The numbers tell the story. As of 7 January, nearly 1.5 million people in the UK had been given a first dose of one of the three vaccines approved by the UK regulator. To reach the mid-February target that prime minister Boris Johnson announced on 4 January, 300,000 doses need to be administered every day. That is roughly the rate at which doses were being given each week at the end of December and start of January. “This is the biggest vaccine programme ever that the UK has had to roll out. It’s definitely new territory,” says Doug Brown at the British Society for Immunology. On 11 January, the UK government began publishing daily updates on the number of people given their first of two vaccine doses. There is no historical precedent for vaccinating people at this rate in the UK. The biggest annual programme, the flu vaccine, normally sees around 9 million people a year vaccinated. But that happens over a five-month period starting in September, averaging 60,000 doses a day and peaking at about 150,000 in late October. And there are key differences between flu vaccines and covid-19 ones, says Nilay Shah at Imperial College London. The big one is that flu vaccine manufacturers, and the regulators who have to undertake quality control on the vaccines, have about five months to “go flat out” and build up huge stocks before they are administered. By contrast, covid-19 manufacturers are still very much in the start-up phase. Although the first step, bulk drug substance manufacturing, has been under way for months, companies wouldn’t have started the next “fill and finish” step of putting doses into vials until closer to regulatory approval.
1-11-21 Megalodon sharks grew 2 metres long in the uterus by eating eggs
Ancient megalodon sharks may have been at least 2 metres long at birth – and they might have grown so large by eating unhatched eggs in the uterus. Kenshu Shimada at DePaul University in Chicago and his colleagues examined an Otodus megalodon fossil that was recovered in the 1860s from 15-million-year-old rock and is now housed at the Royal Belgian Institute of Natural Sciences. Studying the shark’s vertebrae, allowed them to estimate its body size at various stages in its life. “Megalodon’s size at birth was about 2 metres in total, which indicates that it must have given live birth like all present-day lamniform sharks do,” says Shimada. Similar to how a tree trunk has annual growth rings, the shark vertebrae has growth bands. By counting these, Shimada and his team suggest that this megalodon specimen died at 46 years old. Previous studies into O. megalodon have relied on evidence from its teeth to estimate body size. This is because teeth are often the only part of a shark to fossilise, as its skeleton is made of cartilage and not bone. Studying rare vertebral remains is critical to learning more about ancient sharks, says Jack Cooper at Swansea University, UK. The large birth size of O. megalodon suggests that the young sharks, like many present-day sharks, ate unhatched eggs in the uterus to survive – a phenomenon called intrauterine cannibalism. “The consequence is that only a few pups will survive and develop, but each of them can become large in body size at birth which gives [them] an advantage as already large predators,” says Shimada. While the new research has provided information on the growth pattern between birth and middle age, we still know little about megalodon growth later in life.
1-10-21 Coronavirus: Virus provides leaps in scientific understanding
In January 2020, two scientists published the entire genetic code of a coronavirus that was soon to wreak havoc around the world. It marked the start of a year of intense and rapid scientific endeavour, to work out how we might fight the virus. Eddie Holmes had the genetic blueprint for the coronavirus in his possession for exactly 52 minutes before he put it online. Prof Holmes is based at the University of Sydney, where he works on the emergence of infectious disease - an area of research that was suddenly thrust into the spotlight at the beginning of 2020. He has worked closely, for several years, with Prof Yong-Zhen Zhang, who was at the Chinese Centre for Disease Control in Beijing. Prof Zhang sequenced the genome of the virus that closed down the world. He collected samples taken from some of the first patients in Wuhan Central Hospital, where a cluster of mysterious pneumonia cases had emerged. Many of those patients had a link to a seafood and wildlife market in Wuhan. When he examined the code, Prof Zhang immediately saw that this was a coronavirus. It looked very similar to Sars - the respiratory disease that caused a deadly outbreak in Asia in 2002. "That was on 5 January," recalls Prof Holmes. "And we just thought,oh no. It's Sars back again." But this code - this virus - was different. It was new. Prof Zhang and Prof Holmes quickly submitted a paper describing what they had seen and, as the week wore on, a buzz of public health speculation about what the novel virus might be started on social media. "I didn't sleep," Prof Holmes tells me. "It was weighing on my conscience." In Sydney, it was early on 11 January when Prof Holmes phoned his colleague in China and asked his permission to publish the sequence. "Zhang was on a plane, strapped into his seat," Prof Holmes recalled. "He told me he needed to think about it - there was some pressure not to release too much information about the outbreak.
1-8-21 A new polio vaccine joins the fight to vanquish the paralyzing disease
The modified vaccine seeks to end outbreaks in the Middle East and Africa. After decades of work and mass vaccination campaigns that have spared millions of children from paralysis, the world is close to wiping out polio. But a small number of outbreaks that have simmered in areas of low vaccination remain. And some happened after weakened virus in the oral polio vaccine, over time, moved around a community and regained the ability to cause disease. No other vaccines made with weakened live viruses have caused outbreaks of disease. To stamp out vaccine-derived polio outbreaks, the World Health Organization has granted emergency use for a new polio vaccine. The oral vaccine got the go-ahead on November 13. “We are very, very enthusiastically looking forward to using this new vaccine,” says medical epidemiologist Chima Ohuabunwo of Morehouse School of Medicine in Atlanta, who has worked on polio eradication in Africa for more than two decades. Along with continuing the crucial work of improving vaccination coverage in places where it is low, the new vaccine will “hopefully … take us to the finishing line of polio eradication.” Eight years after the WHO’s 1980 declaration that the world was free of smallpox, the Global Polio Eradication Initiative launched to tackle polio. The disease was a promising candidate for eradication. An effective, easily administered and cheap vaccine was available. And poliovirus, which naturally infects only humans, doesn’t hang around in other animals in between outbreaks. Most people who become infected with poliovirus don’t feel sick, while some have flu-like symptoms. But about one in 200 become paralyzed for life. Although not a routine threat in the United States since the early 1950s (SN: 9/12/19), polio has continued to harm people, especially children, around the world.
1-8-21 Origins of human music linked to our ancestors’ daredevil behaviour
Our primate ancestors might have become “protomusical” to advertise their ability to perform death-defying leaps from tree to tree. Why humans make and appreciate music is an evolutionary mystery. “Music is a hugely important part of our lives and often involves powerful emotions,” says Edward Hagen at Washington State University. But he says we still don’t fully understand why it has this hold over us. David Schruth at the University of Washington and his colleagues have a new explanation. They say the roots of human music can be traced back to the branches of trees more than 50 million years ago, when the first primates appeared. Fossil evidence suggests that those early primates moved around the forest canopy by leaping from branch to branch, a perilous way to travel that relies on extremely good coordination and muscular control. Schruth and his colleagues argue that early primates sought out sexual partners that were skilled acrobats, and singing would have helped them choose. Put simply, a primate that calls in an elaborate, musical way is advertising that it has fine control over its vocal cord muscles. Schruth’s team say that this might have convinced other primates that the caller also had fine control over its limbs. To test the idea, the team assessed the musicality – for instance, the tone and the rhythm – of 800 acoustic calls by 60 living primate species, and examined data on how often the species leap and swing from branches. The team found that the species that leap and swing the most tend to have more complicated calls, dubbing these as “protomusical”. Schruth says music doesn’t lend itself well to a single, clear definition, which has a huge impact on how researchers explore its roots. “Whoever defines the phenomena gets to tell the origin story,” he says.
1-8-21 Climate change: 2020 was the joint hottest year on record
Last year was the joint hottest globally and by far the warmest year recorded in Europe, making the years from 2015 onwards the warmest six on record. Global average temperatures tied with 2016 at 0.6°C above the long-term average – despite the absence of an El Niño event, a climate phenomenon that has a warming effect. There was an El Niño in 2016. Europe, by contrast, demolished records by a wide margin, at 1.6°C above the long-term average. This compared with 2019’s 1.2°C above the average – itself record-breaking at the time. Norway and Sweden both had their hottest years on record. Although the figures today from European Earth observation programme Copernicus place 2020 as joint hottest globally, aggregated data from other major temperature data sets including those of US agencies NASA and NOAA, and the UK Met Office – expected next Thursday – may yet relegate it to the second or third warmest. Copernicus’s 2020 figures show a clear north-south split, with below-average temperatures in the southern hemisphere and above-average ones in the northern hemisphere. Siberia and other parts of the Arctic were exceptionally warm, at 3-6°C above average in some regions. “The year 2020 was extreme for the Arctic, even compared to the past 20 years,” said the US National Snow and Ice Data Center in a statement on Tuesday. That led Arctic sea ice to shrink to its second-lowest extent on record in September 2020. Figures published this week by Mark Parrington at Copernicus also show that, while media attention focused on exceptional blazes in the US and Australia, globally wildfires were at one of their lowest levels in two decades due to below-average fires in Africa. Separately, the UK Met Office today said it expects carbon dioxide levels in the atmosphere this year to pass the milestone of being 50 per cent higher than before the industrial revolution, reaching 417 parts per million between April and June, when seasonal CO2 levels peak.
1-8-21 Climate change: 2020 in a dead heat for world's warmest year
New data from EU satellites shows that 2020 is in a statistical dead heat with 2016 as the world's warmest year. The Copernicus Climate Change Service says that last year was around 1.25C above the long-term average. The scientists say that unprecedented levels of heat in the Arctic and Siberia were key factors in driving up the overall temperature. The past 12 months also saw a new record for Europe, around 0.4C warmer than 2019. Last December, the World Meteorological Organization predicted that 2020 would be one of the three warmest years on record. This new, more complete report from Copernicus says that last year is right at the top of the list. The Copernicus data comes from a constellation of Sentinel satellites that monitor the Earth from orbit, as well as measurements taken at ground level. Temperature data from the system shows that 2020 was 1.25C warmer than the average from 1850-1900, a time often described as the "pre-industrial" period. One key factor driving up the temperatures was the heating experienced in the Arctic and Siberia. In some locations there, temperatures for the year as a whole were 6C above the long-term average. This exceptional warming led to a very active wildfire season. Fires in the Arctic Circle released a record amount of CO2, according to the study, up over a third from 2019. The Copernicus service concludes that while 2020 was very marginally cooler than 2016, the two years are statistically on a par as the differences between the figures for the two years are smaller than the typical differences found in other temperature databases for the same period. More data on 2020's temperature will be released in the next week or so from other agencies, including Nasa and the UK Met Office. The scientists say that the closeness between the years is all the more remarkable considering the impacts of the El Niño/La Niña weather cycle.
1-8-21 Groundwater that supports world food chain may become too salty to use
Groundwater basins that provide water for much of the world’s food production are in danger of becoming too salty for plants and animals. This risk will remain even if care is taken not to deplete them further. A groundwater basin is a large geological structure in which vast quantities of freshwater are stored in volumes of buried, permeable rocks called aquifers. Often the basin is in an “open” state, which means water is constantly flushed through it. But if the water level falls too low, the basin can become “closed”, which means water cannot leave the aquifers via rivers or underground flows. Once a basin is closed, salt leaching into the groundwater will never be flushed out of the aquifer again, so it accumulates. Irrigation may cause both the closure of a basin and worsen the resulting problems. As groundwater is pumped up for agriculture, part of it will evaporate and leave behind salt deposits. These are eventually washed into the aquifer again, making it more saline from the top down. Hydrologists Graham Fogg and Rich Pauloo at the University of California, Davis call this process ABCSAL, which stands for Anthropogenic Basin Closure and groundwater Salinisation. They have just conducted a detailed study of the important Tulare Lake basin in the southern Central Valley of California, where just over 12,000 irrigated square kilometres of land produce more than $23 billion in crops annually. They conclude that the first stage of salinisation is already happening there. Shallow groundwater may deteriorate over decades, says Fogg. The quality of deeper reserves may only become a problem after two or three centuries. Yet he notes that this could come sooner than the current estimates of the expected exhaustion of a basin.
1-7-21 Electric cars' best ever year is a tipping point for green transport
Fossil fuel-powered cars aren’t yet consigned to the scrapheap, but they are fast travelling down a one-way road towards it. The pandemic triggered dire new car sales in the UK, which fell by 29 per cent back to levels seen in 1992, figures published yesterday show. Yet sales of new, fully electric cars bucked the trend, rocketing by almost 186 per cent to more than 108,000. That may seem like a drop in the traffic jam when you consider more than 900,000 petrol ones were sold over the same period, but just look at the rate of change. In the UK, more electric cars were sold last year than in the previous decade. Motorists, like progressive leaders and car makers, have woken up to the fact that petrol and diesel cars are on the way out, destined to follow incandescent lightbulbs into history. It isn’t just the UK: the boom is happening across Europe. In Norway, long a pioneer of carrots and sticks to wean people off petrol and diesel, electric models overtook fossil fuels ones for the first time in 2020. These tipping points matter. Transport has eclipsed energy to become the biggest carbon emitter in the UK, along with many other countries. We need this electric boom if we are to stand any chance of avoiding climate change’s most devastating effects. Toxic traffic also harms and kills us in the short term: witness the inquest last month that found air pollution played a role in a 9 year-old girl’s death. Why now? Some of it is down to specific policies in individual countries. The UK’s numbers were turbocharged by the government allowing firms to pay no company car tax from April 2020 to April 2021, compared with the 20 to 37 per cent charged on petrol and diesel cars. Most of the plug-in cars sold last year were company cars. It is also about growing choice. More new electrified models are due in the UK this year than new petrol or diesel ones, though that does include plug-in hybrid electric vehicles, which run a short distance on battery before a combustion engine kicks in. Strikingly, the UK’s best-selling car last December wasn’t a Volkswagen Golf or a Ford Fiesta, but the electric Tesla Model 3, which starts at £40,490.
1-7-21 Severe allergic reactions to COVID-19 vaccines are extremely rare, CDC says
Vaccine sites should still be prepared for the dangerous but treatable reaction. Out of the first 1.9 million doses of Pfizer’s COVID-19 vaccine administered in the United States, there were 21 reported cases of severe allergic reactions to the vaccine, the Centers for Disease Control and Prevention said January 6. The rate of anaphylaxis seen so far — 11.1 cases per 1 million vaccine doses — is higher than for the flu vaccine, which is 1.3 cases per 1 million doses, Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, said in a Jan. 6 news briefing. But the reactions to COVID-19 vaccines are “still exceedingly rare,” she said. “These are safe and effective vaccines. We have good data to show that,” Messonnier said. The country’s surveillance systems for vaccine side effects are “incredibly robust,” she said, and “the only thing that we that have seen is these severe allergic reactions.” Still, sites that administer COVID-19 vaccines need to be able to recognize the signs of anaphylaxis — which, if it occurs, would most likely happen shortly after vaccination — and be prepared to treat it, CDC officials said. And people who have a history of anaphylaxis as a result of any cause should be observed for 30 minutes after receiving a COVID-19 vaccine. Anaphylaxis, which can be life-threatening, requires emergency treatment with epinephrine. The United Kingdom, which began immunizing its population against COVID-19 with the Pfizer vaccine December 8, was the first country to report cases of the severe allergic reaction following vaccinations (SN: 12/11/20). The CDC reported on the 21 cases in the United States, which cover vaccinations given from December 14 to 23, in a Morbidity and Mortality Weekly Report study published online January 6. These first vaccinations were only with Pfizer’s vaccine. Officials don’t yet know what is causing the allergic reaction after immunization with the vaccine.
1-7-21 UK consultation launched over gene edited food
The UK government has launched a public consultation on using gene editing to modify livestock and food crops. Gene editing alters the DNA of organisms and, until now, its use had been tightly restricted under EU law. Environment Secretary George Eustice said the approach could be used to develop crops that are more resistant to disease and extreme weather. He said it could also lead to the production of healthier food, but some are opposed to the technology. Critics say it creates entirely new organisms, and maintain that stringent regulation is vital. Gene editing involves making precise changes to the DNA of one particular species and many scientists regard it as distinct from genetic modification (GM), where DNA from one type of organism is introduced to another. However, in 2018, the European Court of Justice ruled that it did, in fact, count as genetic engineering. And, in the EU, both technologies are currently under strict regulation. Speaking at the Oxford Farming Conference, Mr Eustice said the UK no longer had to "slavishly follow" European law, which was "notoriously restrictive and politicised". The Environment Secretary said the technology mimicked the natural breeding process, speeding up what farmers have done for centuries by picking the strongest and healthiest animals or plants to breed from. Mr Eustice said that gene editing raised far fewer ethical or biological concerns than other forms of genetic engineering. He said the organisms created by gene editing could have been created naturally and so "respected the laws of nature". Many scientists have welcomed the consultation. Denis Murphy, professor of biotechnology at the University of South Wales said it would be broadly supported by UK farmers and crop scientists. He explained: "Genome editing is already used in medicine and has immense potential for tackling major agricultural challenges related to food security, climate change, and sustainability."
1-7-21 Plague may have caused die-offs of ancient Siberians
Bacterium DNA was found in two skeletons dating to roughly 4,000 years ago. Ancient people brought the plague to Siberia by about 4,400 years ago, which may have led to collapses in the population there, a new genetic analysis suggests. That preliminary finding raises the possibility that plague-induced die offs influenced the genetic structure of northeast Asians who trekked to North America starting perhaps 5,500 years ago. If the result holds up, it, along with other newly uncovered insights into human population dynamics in the region, would unveil a more complex ancestry among those ancient travelers than has usually been assumed. A team led by evolutionary geneticists Gülsah Merve Kilinç and Anders Götherström, both of Stockholm University, extracted DNA from the remains of 40 human skeletons previously excavated in parts of eastern Siberia. Among those samples, DNA from Yersinia pestis, the bacterium that causes plague, was found in two ancient Siberians, the researchers report January 6 in Science Advances. One person lived around 4,400 years ago. The other dated to roughly 3,800 years ago. It’s unclear how the plague bacterium first reached Siberia or whether it caused widespread infections and death, Götherström says. But he and his colleagues found that genetic diversity in their ancient samples of human DNA declined sharply from around 4,700 to 4,400 years ago, possibly the result of population collapse. The new data coincide with evidence reported in June 2020 in Cell of Y. pestis DNA in two ancient individuals from eastern Siberia’s Lake Baikal region, dating to around 4,500 years ago. The plague may well have reached Siberia by roughly 4,500 years ago, at a time when Y. pestis infected people inhabiting other parts of Eurasia (SN: 10/22/15), says evolutionary geneticist Hendrik Poinar of McMaster University in Hamilton, Canada who did not participate in the new study.
1-6-21 Covid-19’s many unknowns are what make it so tricky to beat
IN THE UK, back in July, covid-19 cases had dropped so much that politicians spurred people to dine out to boost the economy. Citizens were told that restrictions on daily life would be over “in time for Christmas”. That didn’t happen. Instead, as the northern summer ended, infections climbed, and kept on climbing despite complicated systems of protection levels and tiers, as did the number of people in hospitals. With hospitalisations now perilously high, nearly all parts of the UK are back under strict lockdown conditions. Of course, the UK isn’t the only nation struggling with second or even third waves. Many countries that felt they were on top of the virus are now struggling to keep it suppressed. Vaccines should provide an escape route – new variants and any other surprises allowing. But as we have said many times on these pages, there are still hard yards ahead. So why is this virus proving so difficult to deal with? Jonathan R. Goodman argues that it is because this virus is a riddle, on multiple levels. We can’t tell, by looking at someone, if they have it. We can’t tell, even with someone’s medical chart in our hands, how sick they will get from it. We are getting better at treating people who become seriously ill, but we can still only guess who will die, and why. And the greatest riddle is what we should do about it all. Other diseases kill more of the people who are infected: MERS killed 33 per cent of those who caught the virus, SARS 10 per cent. Those sorts of death rates prompted unequivocal action from governments. But with this coronavirus, we are looking at a death rate of about 1 per cent. That opens the door to politicians and commentators getting wrapped up in cost-benefit analyses, agonising over impacts to economies and healthcare when contrasted against this relatively low death rate. What should be clear now is that the time for underestimating the coronavirus is over. The sooner we can get people vaccinated, and stop this virus running around populations with unknown outcomes, the better. Until then, life cannot return to normal.
1-6-21 Five reasons the covid-19 pandemic has been such a nightmare
Humans have faced pandemics before, but some unusual features of covid-19 and modern society have conspired to create the perfect storm this time. WAS “unprecedented” the most overused word of 2020? There is no doubt that covid-19 has had an extraordinary range of consequences, from turning toilet paper into a treasured commodity and making handshakes taboo to closing schools and putting whole countries in lockdown. But humans have always had to face diseases. Is this one really so different from the others? As vaccines come into use and we start to see light at the end of the tunnel, it is worth considering this question. There is no doubt that governments, institutions and individuals have made mistakes when trying to deal with covid-19. But perhaps we can be forgiven for some of those failings, because over the past year it has become clear that this disease has unusual attributes. These, combined with certain features of the modern world, may have created the perfect pandemic storm. Whether in our judgements about lockdown and personal risk or in questions about where the virus came from and is going, we really have faced some unprecedented challenges. In January 2020, as news emerged that a lockdown had been imposed in Wuhan, China, in an attempt to stop the spread of a new disease, few citizens of other countries could have imagined that their lives would soon be similarly restricted. Quarantine has long been used as a weapon against infectious diseases, from the English village of Eyam’s response to plague in 1665 to action taken in West Africa to curb Ebola outbreaks in the 21st century. However, a year ago, the idea that democratically elected governments would forcibly curtail the freedoms of whole nations seemed unthinkable to many. A key difference between covid-19 and past outbreaks of infectious diseases is its relatively low mortality rate. No country shuts down its economy when faced with seasonal flu – which is responsible for as many as half a million deaths worldwide every year – but where do you draw the line? SARS-CoV-2, the virus responsible for the covid-19 pandemic, certainly kills a higher percentage of people who contract it than flu does. Most estimates suggest a mortality rate of about 1 in 100 people, although it has been difficult to pin down, with estimates ranging from 0.5 to 3.5 per cent. Covid-19 is definitely far less deadly than Ebola, though, which without medical intervention kills more than 80 per cent of people who get it. As a result, policymakers haven’t always known how to act.
1-6-21 Two children with cancer may have acquired tumour cells before birth
Two children with lung cancer in Japan acquired the tumour cells from their mothers during or shortly before birth – an incredibly rare way of developing the disease. Chitose Ogawa at the National Cancer Center Hospital in Tokyo and her colleagues made the discovery while sequencing the DNA of the children’s tumours for a prospective clinical trial. The first boy was diagnosed with lung cancer at 23 months old, while the second boy was 6 years old when he developed chest pain, leading doctors to discover a tumour in his left lung. Both mothers turned out to have cervical cancer: the mother of the first boy was diagnosed three months after the birth and the mother of the second boy was diagnosed following delivery. Analysis showed the boys’ tumours had genetic mutations that matched those in the cancers of their mothers. It also showed that the DNA of the tumour cells from the boys lacked the Y chromosome found in most male cells. The cells also tested positive for strains of human papillomavirus – which is known to trigger cervical cancer. Some cancer cells probably escaped into amniotic fluid during late gestation, or were transmitted to the children during their birth, says Paul Ekert at the Children’s Cancer Institute in Sydney, who wasn’t involved in the research. Both children were born vaginally, and it is possible that they inhaled tumour cells. Such instances of mother-to-infant transmission of cancer are astonishingly rare. Approximately one in 1000 live births involves a mother who has cancer, and transmission is estimated to occur in one infant for every 500,000 mothers with cancer. Most child cancer specialists might see it once in a lifetime, says Ekert, an expert in paediatric oncology. “Ordinarily, it would be mitigated against because of the immune surveillance for contaminating cells from another individual – even if that individual is related,” he says.
1-6-21 CRISPR doubles lifespan of mice with rapid ageing disease progeria
CRISPR gene editing has been used to more than double the lifespan of mice engineered to have the premature ageing disease progeria, also greatly improving their health. The results far surpassed expectations. Progeria affects many different organs in the body, and the team behind the work didn’t expect that correcting the mutation in a relatively low proportion of cells – 10 to 60 per cent – would have such a big effect. “We were quite amazed,” says David Liu at Harvard University. Hutchinson-Gilford progeria syndrome is a rare condition caused when a mutation, which probably took place in the testes or ovaries of a child’s parents, results in a single DNA letter change in one of the two copies of the gene for the lamin A protein. This leads to the production of an abnormal protein called progerin that interferes with cell division and causes many symptoms of premature ageing. The average lifespan of children with progeria is 14 years. Conventional gene therapy, which involves adding genes, cannot help. People with progeria still have one healthy copy of the lamin A gene – the problem is the mutant progerin protein. The standard form of CRISPR gene editing, which involves cutting DNA with the Cas9 protein, can be used to disable the mutant gene. The trouble is that it often disables the healthy copy too, as well as causing other unwanted changes. Liu’s team has been modifying the Cas9 protein so instead of cutting DNA, it changes one DNA letter to another, a process known as base editing. He and his colleagues have now used a CRISPR base editor to correct the single-letter change that causes almost all cases of progeria, first in skin cells taken from a person with progeria and then in mice with a human version of the lamin A gene.
1-6-21 New coronavirus variants: What are they and how worried should we be?
Since the start of the pandemic, there have been concerns that the coronavirus could evolve to become more dangerous. Now, hospitals in the UK are at risk of being overwhelmed by surging numbers of covid-19 cases and there is growing evidence that this is partly due to a new variant of the virus that spreads more readily. This variant has already reached many other countries. Hospitals in South Africa are also being overrun, due to a resurgence of covid-19 being blamed on another variant of SARS-CoV-2, the virus responsible. It isn’t yet clear how much faster this variant, called B.1.351, spreads. Yet initial studies of the variant from the UK, known as B.1.1.7, estimate that it is around 40 to 74 per cent more transmissible. This may be because people infected with it shed more of the virus. In response to these initial studies and high UK transmission rates, England and Scotland this week joined Wales and Northern Ireland in another period of strict lockdown, during which most schools and universities will use remote learning. “No matter how the virus changes, it needs us to be close enough to each other and to have interactions to let it jump between us,” says Emma Hodcroft at the University of Basel in Switzerland. “If we don’t give the virus those opportunities, it simply can’t spread no matter what variant it is.” Neither new variant appears any deadlier. But there is concern that current vaccines could be less effective against B.1.351. The new variants were discovered by sequencing the entire genome of the virus, which is around 30,000 RNA letters long. Researchers around the world routinely sequence samples to track the spread of the coronavirus and see how it is evolving. Such efforts have found there are already tens of thousands of “mutant” viruses that differ from each other by at least one mutation. This is unsurprising as viruses constantly mutate.
1-6-21 Coronavirus variants and mutations: The science explained
The rapid spread of coronavirus variants has put the world on alert and triggered a new lockdown in the UK. What are these variants and why are they causing concern? All viruses naturally mutate over time, and Sars-CoV-2 is no exception. Since the virus was first identified a year ago, thousands of mutations have arisen. The vast majority of mutations are "passengers" and will have little impact, says Dr Lucy van Dorp, an expert in the evolution of pathogens at University College London. "They don't change the behaviour of the virus, they are just carried along." But every once in a while, a virus strikes lucky by mutating in a way that helps it survive and reproduce. "Viruses carrying these mutations can then increase in frequency due to natural selection, given the right epidemiological settings," Dr van Dorp says. This is what seems to be happening with the variant that has spread across the UK, known as 202012/01, and a similar, but different variant, recently identified in South Africa (501.V2). There is no evidence so far that either causes more severe disease, but the worry is that health systems will be overwhelmed by a rapid rise in cases. In a rapid risk assessment of these "variants of concern", the European Centre for Disease Prevention and Control said they place increased pressure on health systems. "Although there is no information that infections with these strains are more severe, due to increased transmissibility, the impact of Covid-19 disease in terms of hospitalisations and deaths is assessed as high, particularly for those in older age groups or with co-morbidities," the EU agency said. The variants have different origins but share a mutation in a gene that encodes the spike protein, which the virus uses to latch on to and enter human cells. Scientists think this could be why they appear more infectious. "The UK and South African virus variants have changes in the spike gene consistent with the possibility that they are more infectious," says Prof Lawrence Young at the University of Warwick.
1-6-21 What does smell loss reveal about covid-19, and how long will it last?
A WEEK or so after Jackie Dishner lost both her sense of taste and smell, her diagnosis was confirmed – she had covid-19. Dishner, an artist living in Phoenix, Arizona, knew that anosmia was a possible symptom of the disease, but she never imagined that after six months, most smells would still elude her, except perhaps the whiff of a particularly strong cup of coffee. She would also occasionally detect phantom odours. Studies reveal that between 40 and 85 per cent of people with covid-19 experience the loss of their olfactory senses, making it one of the most consistent indicators of infection. Perhaps more importantly, anosmia often shows up days before more concerning, and sometimes life-threatening, respiratory issues. We are now building a picture of why the virus causes smell loss, how this symptom could be used for better diagnosis, and how likely people are to get their sense of smell back. “Unfortunately, if you can’t smell at the year mark, you probably won’t get your sense of smell back” Certainly, other viruses, including those behind flu and the common cold, can diminish our sense of smell. But this tends to be because the airways are blocked by mucus, preventing air from reaching the olfactory receptors in the nose. The sense of taste is also affected because much of what we perceive as flavour comes from odour molecules in food. The issue then clears up, along with the other symptoms. The smell loss due to SARS-CoV-2, the virus that causes covid-19, is very different. “You don’t really see the same kind of nasal congestion with covid-19. Which raises questions: what molecular mechanisms might be leading to this smell loss, what does it mean and what does it tell us about this virus?” says Michael Xydakis, an ear, nose and throat surgeon with the US Air Force who studies anosmia.
1-6-21 Low-carb diets: An easy way to lose weight or recipe for heart attack?
More people are cutting carbs and filling up on fat and protein to lose weight or get healthier – despite warnings about this boosting cholesterol. New Scientist investigates the true risks of low-carb life. COUNTLESS fad diets come and go, but these days there is one we never stop hearing about. Whether you call it low-carbing, Atkins, keto or paleo, the principle is the same: cutting down on starchy food and filling up on fat and protein. Low-carbohydrate diets are increasingly being endorsed by obesity and diabetes specialists, and a growing number of trials show that the approach helps people lose weight at least as much as traditional low-fat, low-calorie regimes. More and more people are eating this way, not to lose weight, but because they see it as healthier. Yet many doctors warn that low-carbing is dangerous. They point to large-scale population studies linking low-carb diets to increased risk of heart attack, stroke and premature death. The puzzling thing is, those warnings don’t seem to square with findings from clinical trials, generally a better kind of medical evidence than population studies. Several have now shown that low-carb diets generally don’t raise the levels of “bad cholesterol”, long seen as a major risk factor for heart attack and stroke. Even in people who do see a rise, other markers of heart health usually improve. It is so confusing that some wonder if we have got the causes of heart disease all wrong. “This has led me to question whether I believe in the cholesterol hypothesis at all,” says Eric Westman, an obesity specialist at Duke University in North Carolina. As rising rates of obesity and diabetes threaten public health, the questions around the safety of low-carb diets are becoming increasingly urgent. So, is ditching carbs a safe way to lose weight and stay healthy – or a recipe for heart attack?
1-6-21 How schools can reduce excessive discipline of Black students
Keeping Black children in school requires changes to systems and mind-sets. Anne Gregory remembers the child’s fondness for the Dewey decimal system. He would write down a combination of numbers and letters on a scrap of paper and hunt down the desired book in the library. Details were his thing. He once wrote several pages outlining the sequence of moves needed to beat a video game, she says. But at the elementary school where Gregory worked as a counselor, educators saw a different child. A troublemaker. One teacher told Gregory that the boy frequently wandered about mid-lesson. So the teacher moved his desk to the far corner of the room, and sometimes sent him to the principal’s office. Outside the principal’s door, the boy joined a queue of almost all Black boys. But Black and Latino students together made up just over half of the school’s student population. Gregory brought up her concerns with the principal. Why was that little boy always in trouble? Why did that line of supposed troublemakers skew Black and male? This was the mid-1990s, a time when educators and researchers knew Black students, on average, scored lower on standardized tests than white students. This “achievement gap” was, by then, a cause for concern. But how educators treated Black children was rarely part of the discussions. The principal told Gregory that her concerns, while potentially valid, were “too hot” to tackle. “I could just see how much the school structure itself was squelching this African-American boy’s potential and all his strengths,” Gregory says. “That, accompanied with the silence around this at his school, demonstrated to me the absolute urgency, the need, to point this out.” Gregory, now a psychologist at Rutgers University in Piscataway, N.J., has devoted her career to pointing out the problem. In the January 2010 Educational Researcher, she and colleagues used the term “discipline gap” to characterize what she’d observed: Black students, particularly boys, were punished more frequently and severely than their white peers — despite a lack of evidence that the Black kids were committing more offenses. Those punishments ranged from teachers sending students to the principal’s office to expulsion. Black students’ disproportionate removal from school may well underlie the achievement gap, Gregory and others contend.
1-6-21 Is digging a tunnel under Stonehenge good or bad for archaeology?
A PUBLIC row has broken out among archaeologists over the UK government’s decision to allow the building of a road tunnel close to Stonehenge, a protected prehistoric monument in Wiltshire. The tunnel is intended to replace a congested road that disrupts the landscape around the site, but some argue that the plans will cause irreparable damage to archaeological deposits. While digging near ancient history may seem like an obviously bad idea, the case isn’t clear-cut. Stonehenge is a ring of standing stones surrounded by an earth bank and ditch that was probably erected between 3000 and 2000 BC. It has long been protected by British law, and it was listed as a World Heritage Site by UNESCO in 1986, meaning it is protected by international treaty. UNESCO forbids any sort of damage to the sites it protects, but Stonehenge has a problem. A major road, the A303, was built long before the 1986 listing and runs right past the monument, spoiling the uninterrupted landscape in which Stonehenge was originally situated. “It’s just appalling,” says Mike Pitts, an archaeologist and author of Digging Up Britain. The UK government’s solution is essentially a form of corrective surgery, replacing the road with a 3.3-kilometre tunnel under the World Heritage Site. It was approved by UK transport secretary Grant Shapps on 12 November 2020 against the recommendation of planning officials. Like any kind of surgery, some damage is inevitable, which is why the plan takes precautions. Before the tunnel is dug, a consortium of archaeologists led by heritage company Wessex Archaeology in Meopham, UK, will conduct detailed surveys, sampling and excavations along the route, with the aim of ensuring that no significant sites or artefacts are destroyed. The team has already carried out surveys as part of the route’s approval process.
1-5-21 Fossilised nest shows some dinosaurs sat on their eggs like birds do
A fossilised oviraptor found on top of a clutch of eggs confirms that at least some dinosaurs sat on or near their eggs to keep them warm, as birds do. The eggs contain late-stage embryos that developed at temperatures of up to 38°C. There is already strong evidence that some dinosaurs brooded eggs like birds do. Several fossils of adult oviraptors – bird-like dinosaurs that were around 2 metres long, including their tails – have been found on or near clutches of eggs. Yet not all researchers are convinced. Many think even small dinosaurs may have been too heavy to sit atop their eggs without damaging them. Some argue that the oviraptors found on nests died while laying eggs rather than during brooding or while remaining close to guard the eggs. Now a team led by Xing Xu at the Chinese Academy of Sciences in Beijing has described and analysed a fossil found near Ganzhou in China. It consists of the partial remains of an adult oviraptor on top of at least 24 eggs, many of which have embryos inside. Eggs with embryos have been found before, but not in association with an adult, says team member Michael Pittman at the University of Hong Kong. “This is the first time that we have everything in one specimen.” The fact that the embryos are at a late stage shows the adult wasn’t laying eggs at the time it died. What’s more, the team also looked at the ratios of oxygen-18 to oxygen-16 isotopes in the carbonates in the eggshells and embryo bones. These ratios reflect the temperature at the time the carbonates formed. For two eggs, the isotopic analysis suggests that the embryos developed at around body temperature – between 36°C and 38°C. This shows the eggs were being brooded, not just guarded, says Pittman. For the third egg analysed, which was further from the body of the adult, the developmental temperature would have been between 30°C and 32°C. The phenomenon of some eggs developing at a lower temperature is seen in some modern birds too, says Pittman.
1-4-21 Home baking frenzy inspires tissue scaffold for growing human muscle
All that pandemic baking has produced more than just delicious bread. It also inspired a team of tissue engineers to try using bread as a scaffold for growing cells – and after some experimentation, they succeeded with Irish soda bread. One potential use for the bread scaffold could be for growing meat in factories for food. “It seemed like a fitting project for these times,” says Andrew Pelling at the University of Ottawa in Canada. Many groups around the world are working on ways of growing living tissues and organs outside the body for treating all kinds of disorders. For instance, in China, five children born with an underdeveloped ear have been given a replacement grown from their own cells. A common method for this is to “seed” a scaffold with cells. Such scaffolds are typically made from the protein collagen, which is a supportive material found in our bodies. But collagen scaffolds are expensive, as well as problematic because they usually come from animals or cadavers. Pelling and his team have been experimenting with several plant-based alternatives. In 2016, they grew human ears using apples as a scaffold. These were carved into the shape of ears and all the living cells were removed, leaving a cellulose scaffold that was seeded with human cells. Now, Pelling and his colleagues have used bread as a scaffold. They baked it, removed small portions, sterilised them by soaking in alcohol and then seeded them with various cells. The first attempts resulted in a soggy mess, as did all the efforts with gluten-free recipes. Irish soda bread turned out to work the best, though the team did have to reinforce its structure by treating it chemically to create more cross-links between the bread’s fibres. The researchers found that several cell types, including skin, muscle and bone cells, are able to infiltrate the soda bread scaffolds and proliferate. “We now have another very accessible type of biomaterial,” says Pelling. “It’s remarkable to me how human and animal cells have this capacity to grow in really odd, artificial environments.”