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97 Evolution News Articles
for April 2018
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4-30-18 New genetic details may help roses come up smelling like, well, roses
‘Old Blush’ genes hold secrets to biochemistry of scent and long-lived blooms. There’s new hope for making modern roses smell sweeter than the florist paper they’re wrapped in. By decoding the genetics of an heirloom variety, a fragrant pink China rose called “Old Blush,” an international team of researchers has uncovered some new targets to tweak. That roster of genes plus an analysis of scent revealed at least 22 previously uncharacterized biochemical steps the plants can use to make terpene compounds, which help give roses their perfume, researchers report April 30 in Nature Genetics. Modern roses have had a crazy history of blending genes from eight to 20 species, so decoding the DNA hodgepodge has been difficult. Rose breeders have opted for “showy plants,” says molecular geneticist Mohammed Bendahmane of École Normale Supérieure in Lyon, France. In the process, fragrances dwindled, and efforts to build them back in have not been fabulous. The new paper focused on Rosa chinensis, one of the major contributors to modern hybrids, now mixed with European and Middle Eastern lineages of roses. The study’s new details clarify that some of the rose’s genes work in opposition to one other, with some turning on to brew a scent component while others shut down manufacture of anthocyanin pigments needed for rosy petals. Knowing this could help modern rose breeders resolve a trade-off that has sacrificed scent for color.

4-30-18 Women who eat more pasta tend to get menopause earlier
Eating more white pasta and rice has been linked to reaching menopause a year or so earlier than average, while eating oily fish is linked to later menopause. A study of more than 900 women in the UK has found that eating more white pasta and rice is linked to getting menopause earlier, while a diet rich in oily fish is linked to later menopause. However, it is not possible to tell if these diets directly affect the onset of menopause, or if they merely reflect some other, hidden factor. Janet Cade, at the University of Leeds, UK, and colleagues analysed data from 900 women who experienced menopause between the ages of 40 and 65. They found that the average age of menopause was 51, but that certain foods were associated with when menopause begun. Women who ate an additional daily portion of refined white pasta or rice tended to reach menopause around one-and-a-half years earlier than average, while an extra daily serving of oily fish was associated with a delay of more than three years. Diets high in fresh legumes – such as peas and beans – were linked with women reaching the menopause around a year later. Higher intake of vitamin B6 and zinc were also associated with later menopause. “The age at which menopause begins can have serious health implications for some women,” says Cade. Women who go through menopause early can have an increased risk of osteoporosis and heart disease, while those who do so later can be more likely to develop breast, womb and ovarian cancers.

4-30-18 How some resistant bacteria can even eat antibiotics as food
Hundreds of resistant bacteria are able to actively feed on antibiotics. Now we know how - and we may be able to use it to remove antibiotics from our water. Some bacteria are capable of not just resisting antibiotics, but actively feeding on them too. Now researchers have figured out how they do this. Ten years ago, Gautam Dantas at Washington University in St Louis and his colleagues discovered that some bacteria could eat antibiotics by accident. As part of an experiment, they were growing soil bacteria in the presence of penicillin, expecting that this would stop the bacteria from growing. “But we saw exceptional growth on antibiotics,” says Dantas, whose team found that some strains were around 50 times above the threshold at which bacteria are normally classed as antibiotic-resistant, and that they were feeding on the penicillin. Many other types of soil bacteria have been found to do the same since. To find out how they do it, Dantas and his colleagues grew four of these strains under various lab conditions. They focussed on genes that became active when the bacteria were exposed to penicillin, and individually deleted one gene at a time to see what effect this had. This revealed that the bacteria are able to thrive on penicillin using a cocktail of different enzymes – proteins that catalyse chemical reactions.

4-30-18 A fossil may rewrite the story of how plants first lived on land
A plant fossil that lay unnoticed for a century is unexpectedly large for something so old, and it could upend our ideas about the evolution of land plants. A plant fossil that gathered dust in a museum drawer for a century is the oldest fossil of large plants ever found. The find suggests we need to rethink the plant family tree. It has been estimated that land plants first emerged 515 million years ago but actual fossils are rare and not quite so old. Many botanists assume that the first land plants grew like mosses, and more complex plants like shrubs and trees evolved later. However, the new find adds to growing evidence that this picture may be back-to-front. Mosses and their relatives might be more “evolved” than we thought. It all comes down to reproduction. Like most animals, land plants can reproduce sexually, but the details can seem strange to our eyes. A plant embryo first grows into an organism called a “sporophyte”, which has a full complement of chromosomes. The sporophyte can then give rise to a distinct organism called a “gametophyte”, with just half the chromosome set. It’s this organism that produces the egg and sperm cells that fuse to form a new embryo. This life cycle plays out differently in different land plants.

4-29-18 How music lessons help kids learn
Evidence has been building that music lessons boost students' cognitive skills, helping them excel at a wide range of academic subjects. While many studies point in that direction, others are more cautionary, suggesting smarter, more motivated kids may simply choose to take up an instrument. New research from the Netherlands won't end the debate, but it provides solid evidence that instruction in rhythm, melody, and harmony truly has a positive effect on developing brains. Researchers followed 147 Dutch schoolchildren — half of whom took supplemental music-education classes along with their regular curriculum — for over two years, beginning at age 6. "Children who received music lessons showed improved language-based reasoning, and the ability to plan, organize, and complete tasks, as well as improved academic achievement," lead author Artur Jaschke of VU University of Amsterdam said in announcing the findings. "This suggests that the cognitive skills developed during music lessons can influence children's cognitive abilities in completely unrelated subjects, leading to overall improved academic performance."

4-29-18 New genetic sleuthing tools helped track down the Golden State Killer suspect
Mining genealogy databases to find crime suspects raises privacy concerns. Using DNA to find a killer sounds easy: Upload some DNA to a database, get a match and — bingo — suspect found. But it took new genetic sleuthing tools to track down the man suspected of being the Golden State Killer. Investigators have confirmed they used a public genealogy database, GEDmatch, to connect crime scene evidence to distant relatives of Joseph James DeAngelo. The 72-year-old former police officer, arrested April 24 at his home in Sacramento, is suspected in a string of about 50 rapes and 12 murders committed between 1974 and May 1986. The news prompted a flurry of concerns about privacy and ethics — there’s no telling how many people in the public database are being subjected to what amounts to a “genetic stop and frisk,” says Alondra Nelson, a sociologist at Columbia University. But others say they doubt police are actively trolling genealogy websites for suspects. Too many resources are required to do this sort of work, says Sara Katsanis, a genetics policy scholar at Duke University’s Initiative for Science & Society. “I don’t think this is going to become commonplace.”

4-27-18 Serial killer suspect identified using DNA family tree website
A serial killer active in California decades ago may finally have been identified using genetic sequences the suspect’s distant relatives gave to a website. Could this dampen the current enthusiasm for DNA-based family trees? A Californian serial killer may have been identified by genetic samples that his distant relatives gave to a genealogy website. While most people would be happy to help track down a serial killer, there are concerns this could be just the beginning of police using commercial genetics services to investigate other, less serious crimes. Currently, major DNA ancestry companies – such as 23AndMe – say they generally resist police inquiries, unless they have a court order. However, customers often choose to broaden their search for long-lost branches of their family tree by uploading their raw DNA data into a free site called GEDmatch. According to The Mercury News, investigators in California used GEDmatch to help identify the suspect they believe to be the so-called Golden State Killer. This serial killer is thought to have committed more than 50 rapes and 12 murders across California in the 1970s and 80s. This week, investigators arrested Joseph James DeAngelo, a 72-year-old former policeman, and he has been charged with eight counts of murder. They tracked him down by comparing samples taken from a crime scene decades ago with genetic profiles of individuals on the GEDmatch database.

4-27-18 Golfer Jack Nicklaus says stem cell therapy cured his back pain
An experimental stem cell therapy has allowed Jack Nicklaus to return to golf after a lifetime of back pain, and he plans to try it again for his hurt shoulder. Retired pro-golfer Jack Nicklaus has spoken for the first time about how an experimental stem cell therapy has enabled him to play golf again after years of debilitating back pain. Speaking at the Unite to Cure conference on 27 April in Vatican City, Nicklaus – also known as the Golden Bear – told how he had suffered from back pain since he was a child, which was unsuccessfully treated with cortisol injections. Then two years ago, when he was 76, he met doctor Eckhard Alt at the birthday party of American healthcare philanthropist Denny Sanford. It was a serendipitous meeting; Alt had pioneered an experimental stem cell treatment in his clinic in Munich, Germany. “I decided to give stem cells a go,” said Nicklaus, who went on to become one of the first patients. He had to travel to Germany for the treatment because it is not approved in the US, where stem cell therapy is highly regulated. By the time he underwent the treatment in March 2016, Nicklaus’ back pain was so bad he had trouble standing. “I could not hit a golf ball without hurting. I could not stand up for more than 10 minutes,” he said. During the treatment developed by Alt, the source of the pain is first diagnosed using ultrasound. Liposuction is then used to take a sample of fat tissue from the abdomen or buttocks and is then processed to leave a solution rich in fat-derived stem cells. These are of the same lineage of cells that can produce cartilage or bone, says David Pearce, Executive VP of research at Sanford Health in Sioux Falls, South Dakota.

4-26-18 Could a tax on chocolate make us healthy? Let’s not be too hasty
Doctors are calling for an expansion of sugar taxes to include sweets and cakes, but we don’t yet know whether higher prices will lead to improved health. Earlier this month, the UK brought in a new tax on sugary drinks, following a few other countries, including France, Mexico and Finland. As a result, a can of Coke, for instance, now costs 8 pence more, although many brands, such as Ribena, Irn-Bru and Lucozade, have replaced some of their sugar with sweeteners, to a chorus of internet outrage. But the official crusade against the white stuff isn’t stopping there. Now, a group of doctors says we need to start taxing sweet foods, like chocolate, confectionary, cakes and biscuits. The team used data on the shopping habits of more than 30,000 British households to study what happens when the prices of sweet snacks and sugary drinks rise. In both cases, a price hike of 10 per cent reduces purchases by around 7 per cent. Because snacks contribute twice as much sugar to our diets as drinks do, a tax on the former should lead to a bigger fall in consumption, argue Richard Smith of the London School of Hygiene and Tropical Medicine and his colleagues. Yet it is not clear that taxing sugar will achieve our true goal – controlling our ever-expanding waistlines. Almost two-thirds of UK adults are now overweight or obese, with figures being similar in most Western countries. But we don’t actually know why. Too much sugar in our diets isn’t the only possible cause of this widespread weight gain – other causes might be excess of fat, processed food, overall calories and our sedentary lives. We might be focusing on the wrong thing by singling out one particular food group for taxes and bans. Perhaps we would do better to put more effort into teaching children to cook, encouraging more sport participation or changing our cities to help people get around by cycling and walking. No one knows.

4-26-18 Huge haul of ‘depression genes’ shows it’s a complex condition
An analysis of more than 135,000 people with depression has pinpointed 44 genetic variants that are linked to the condition, 30 of which have never been identified before. An analysis of more than 135,000 people with depression has pinpointed 44 genetic variants that are linked to the condition, 30 of which have never been identified before. Depression affects around 14 per cent of people worldwide, but only around half of patients respond well to existing treatments. To better understand how genes may play a role in depression, the Psychiatric Genomics Consortium – an international team involving more than 200 researchers – compared data from more than 135,000 people with depression with nearly 345,000 people who don’t have the condition. The analysis identified 44 variants that are associated with an elevated likelihood of having depression, some of which are also linked to other psychiatric conditions like schizophrenia. “The new genetic variants discovered have the potential to revitalise depression treatment by opening up avenues for the discovery of new and improved therapies,” says Gerome Breen, at King’s College London, who worked on the analysis. However, it is unclear how some of these genes affect depression, and finding a single treatment that can target all these variants is unlikely. Work published earlier this year suggests that a variety of mental health conditions, including depression, involve changes in brain cell function. In particular, inflammation seems to play a role in depression, prompting interest in whether anti-inflammatory drugs may help treat it.

4-26-18 The evolution of eyebrows
It’s a question that has long puzzled scientists: Why are human eyebrows so expressive? Hominins that lived 200,000 to 600,000 years ago boasted a prominent brow ridge, which gave their face a permanently intimidating look and may also have served a structural purpose, as it allowed their skulls to withstand the force of chewing on the tough materials they ate. But modern humans evolved to have a long, smooth forehead with notably agile eyebrows. In a new study, researchers at the University of York in England have offered up a new theory for that evolutionary change. They believe early humans developed more expressive eyebrows out of necessity—that as the species developed increasingly sophisticated forms of communication, social interaction became more vital to their survival. Whereas the thick brow of their ancestors signaled only dominance, eyebrows allowed them to convey a broad range of emotions, from trust to sympathy, friendliness to anger. “We traded dominance or aggression for a wider palette of expression,” lead author Paul O’Higgins tells TheGuardian.com. “As the face became smaller and the forehead flattened, the muscles in the face could move the eyebrows up and down and we could express all these subtler feelings.”

4-26-18 Anthropologists in Peru have unearthed the largest known child sacrifice
550 years ago, the Chimu people may have killed 140 children to appease their gods. A hellishly unprecedented scene — what anthropologists suspect is the largest known child sacrifice — has been unearthed on a bluff overlooking Peru’s northern shoreline. Around 550 years ago, members of the Chimú empire ritually killed and buried at least 140 children, ages 5 to 14, and 200 young llamas, says a team led by Gabriel Prieto of the National University of Trujillo in Peru and John Verano of Tulane University in New Orleans. “There are no other examples of child sacrifices anywhere in the world that compare to the magnitude of this Chimú event,” Verano says. The discovery was announced April 26 by National Geographic in Washington, D.C. Except for a few incomplete skeletons, excavated children and llamas displayed cuts on their breast bones and dislocated ribs indicating that their chests had been sliced open. Three adults buried nearby on the bluff, including two women with violent head wounds, may have participated in the sacrifice. Radiocarbon dating, mainly of ropes left around the llamas’ necks, puts the event at around 1450, shortly before the Inca conquered the Chimú in 1470.

4-26-18 A finger’s point about migration
A roughly 90,000-year-old finger bone found in Saudi Arabia’s Nefud Desert adds to mounting evidence that early human migration out of Africa was considerably more complicated than previously thought. The remains are the earliest Homo sapiens fossil discovered on the Arabian Peninsula, and the oldest outside Africa and the Levant. Until relatively recently, most scientists believed that modern humans first left Africa in a single migration some 60,000 years ago. But along with other recent finds—including 80,000-year-old human teeth in China and tools dating back 65,000 years in Australia—the finger bone suggests our ancestors actually left the continent much earlier, in several different routes. “There’s a growing picture that this old model of single-rate expansion is inaccurate,” lead author Huw Groucutt, from the University of Oxford, tells The Washington Post. “The picture is changing.”

4-26-18 Want to build a dragon? Science is here for you
However, bringing the ingredients together without harming the dragon could get explosive. No fantasy world is complete without a fire-breathing dragon. SpaceX founder Elon Musk even wants to make a cyborg version a reality, or so he tweeted April 25. But if someone was going to make a dragon happen, how would it get its flame? Nature, it seems, has all the parts a dragon needs to set the world on fire, no flamethrower required. The creature just needs a few chemicals, some microbes — and maybe tips from a tiny desert fish. Fire has three basic needs: something to ignite the blaze, fuel to keep it burning and oxygen, which interacts with the fuel as it burns. That last ingredient is the easiest to find. Oxygen makes up 21 percent of Earth’s atmosphere. The bigger challenges are sparking and fueling the flame. All it takes to strike a spark is flint and steel, notes Frank van Breukelen, a biologist at the University of Nevada, Las Vegas. If a dragon had an organ like a bird’s gizzard, it could store swallowed rocks. In birds, those rocks help get around a lack of teeth, allowing them to break down tough foods. Inside a dragon, swallowed flint might rub against some steel, sparking a flame. “Maybe what you have is sort of scales that are flintlike and click together,” van Breukelen says. If the spark was close enough to a very sensitive fuel, that might be enough to ignite it. But some chemicals don’t need that initial spark. Pyrophoric molecules burst into flame the instant they contact air. Consider the element iridium, says Raychelle Burks, a chemist at St. Edwards University in Austin, Texas. It burns different colors when it becomes part of various molecules. One of them burns a warm orange or red. Another burns a violet-blue.

4-26-18 Gross alert: you can get a urinary tract infection from your dog
Just like us, dogs carry many kinds of bacteria – and sometimes, this can spread from a pooch to their owner’s urinary tract, causing painful infections. A word of warning to dog owners: your pooch is a possible source of urinary tract infections (UTIs). UTIs occur when bacteria infect the bladder, urethra or kidneys. They can be very painful, but are usually treatable with antibiotics. About half of all women experience UTIs at some point in their lives, and men can get them too. Most of the time, they are caused by bacteria from a person’s own faeces – usually Escherichia coli. Peter Damborg and colleagues at the University of Copenhagen, Denmark investigated whether pets could also be a source of UTIs. They screened 119 people who were treated for UTIs at Hvidovre Hospital, Copenhagen. Nineteen of those patients lived with pets: six cats and 15 dogs in total. The team asked the pet owners to sample their pet’s faeces with a cotton swab. Genetic analysis of these revealed that two dogs had E. coli bacteria in their stools that were indistinguishable from those that caused their owner’s infections. To find out whether the owners had caught the bacteria from their dogs, or if the dogs in fact might have caught it from their humans, the team asked two of the owners to send more faecal samples 10 months later. Comparing the human and dog samples, the team found that one person didn’t have any sign of their UTI-causing strain in their faeces, but their dog did. This suggests that this dog persistently carries this strain, and was most likely the source of its owner’s infection – although that can’t be proven definitively.

4-25-18 Blood cell and bacteria stuck together to deliver cancer drugs
A red blood cell stuck to a swimming E. coli bacterium can be steered using magnetism and induced to release drugs on demand – perhaps avoiding side effects. A curious hybrid of a red blood cell and an E. coli bacterium could make an ideal transporter for carrying drugs inside the body. Drug treatments often have side effects by causing changes elsewhere in the body, prompting researchers to hunt for clever ways to package drugs and target them more precisely to where they are needed. A previous effort used sperm to carry drugs towards mini tumours in a dish. Cells of E. coli bacteria are also strong swimmers, with a spinning tail that acts like a propeller. However, these cells are small and don’t have much room for cargo. Red blood cells, meanwhile, are big and spacious, but can’t propel themselves. Metin Sitti and colleagues at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany decided to combine the two. They loaded mouse red blood cells with a cancer drug and magnetic nanoparticles, then chemically stuck them onto E. coli bacteria that had been engineered not to cause disease. These hybrid swimmers reached speeds of around 10 micrometres per second, and were easily steered using magnetic fields. The transporter was able to squeeze through tiny channels only 3 micrometres wide, which shows that they can get to anywhere in the circulatory system, says Sitti.

4-25-18 Why growing human brain tissue in a dish is an ethical minefield
The increasing ability to create mini human brains in labs or integrate human cells into animal brains is rightly provoking worries about their use, says Alex Pearlman. The ability of neuroscientists to create, grow and use human brain tissue in the lab is moving fast. So fast in fact that the journal Nature this week published a commentary signed by 17 neuroscientists, biologists and ethicists calling for an ethical framework for this endeavour. The authors outline the three variants of such brain tissue: organoids, known as 3D “mini-brains” or “brain balls”, which are structures grown in the lab from pluripotent stem cells; ex vivo brain tissues, which are those removed from humans and kept alive; and chimeras, or human-animal hybrids, in which human cells are transplanted into the brains of animals. The authors make clear that despite the fact that none of these currently has human capabilities such as feeling pleasure, pain or distress, the possibility is becoming less remote. Organoids have proven incredibly valuable to research investigating how diseases like Alzheimer’s and Zika work within the human brain. They are also, by all accounts, astonishing – the mini-brains can respond to external stimulus, such as a light being shone on them. Meanwhile, chimeras are possibly the most controversial human brain surrogate. Deep ethical concerns about them have been growing recently. In 2017 an investigation by Stat News found that tiny human brain pieces had been implanted into rats and mice, raising the hackles of bioethicists who worried that it could be possible for human-like brain tissue to mature in rodents. According to the call for ethical discussions in Nature, it turned out that such mice “performed better at certain tasks involving learning”.

4-25-18 In China, coffee shop habits show cultural differences tied to farming
Even among longtime city folk, legacy of rice versus wheat agriculture affects behavior. Deeply ingrained cultural differences in everyday behavior between natives of northern and southern China bubble up while sipping coffee in Starbucks and other cafés. How close people sit and whether they dodge or move chairs blocking aisles reveals whether their cultural roots go back to rice farming in southern China or wheat farming in northern China, researchers report April 25 in Science Advances. As many as 9,000 years of neighboring families working together to cultivate rice paddies in southern China has encouraged a lasting focus on others over self, even among that region’s city folk today, say psychologist Thomas Talhelm and colleagues. Social interdependence remains a cultural value of the region, the investigators note. That dynamic plays out in coffee shops. Middle-class city dwellers in southern China who have never farmed rice often sit with others and show deference by walking around chairs blocking aisles, Talhelm’s group says. In northern cities, people more often sit alone and move offending chairs out of the way. A long history of more individualistic wheat and millet farming in the north has promoted a focus on self over others, the scientists propose.

4-25-18 Swedish archaeologists reveal 5th Century massacre at Sandby borg
Swedish archaeologists have found evidence of a 5th century massacre on the south-eastern island of Oland. In a paper published in the journal Antiquity, the team writes about the 1,500 year old attack at Sandby borg. Dozens of corpses have been found in the walled fort, their bodies left to rot where they fell. All of the victims were killed with "brutal force", team leader Helena Victor said. Some victims were found inside houses, others in the streets. The archaeologists discovered decapitated bodies, blunt force trauma wounds to victims' heads, and even one person who seemed to have fallen into a fireplace in his final moments. Even the corpse of a newborn was found among the dead, suggesting nobody was spared, the authors say. The perpetrators of the massacre are not known, but it took place during a turbulent period of intense migration, when the Western Roman empire was collapsing and the Huns invading. The Baltic island of Oland was never under Roman rule. Local authorities asked staff at the Kalmar Lans Museum to examine the area after treasure hunters found items at the site. The first dig lasted only three days, but after the discovery of the walls of houses the team quickly found human remains. Ms Victor says the bodies in the houses raised alarm bells, as historically corpses were usually cremated - and certainly were not left in people's homes. "You don't find people lying around in houses," Ms Victor told the BBC. "[People] don't do it today, and didn't do it then."

4-25-18 Footprints prove humans hunted giant sloths during the Ice Age
Once-hidden prints, visible only in certain conditions, detail a dramatic chase. People tracking giant sloths thousands of years ago in what is now New Mexico left footprints that confirm humans once hunted the giant creatures, researchers report April 25 in Science Advances. Giant ground sloths, which vanished at the end of the last Ice Age around 10,000 years ago, could weigh more than an elephant. With their lethal claws and muscle, the herbivores would have been formidable prey, says David Bustos, a biologist with the National Park Service at White Sands National Monument in New Mexico. In April 2017, researchers stumbled across more than 100 tracks in White Sands. These “ghost tracks” had previously remained hidden because they can be seen only under the right moisture conditions — too little or too much water in the soil, and the outlines of the prints were invisible. Tests of sediment showed the sloth and human prints were made at the same time. An analysis of the tracks also suggested the two species were interacting with one another.

4-25-18 Origin of our species: Why humans were once so much more diverse
The idea that all humans evolved from a small population in East Africa turns out to be wrong. Our beginnings were far stranger and more colourful. IMAGINE visiting a tourist attraction in any major world city. There are people from all over – a Nigerian family, a Chinese couple, a German school party, and more. They all look very different from one another, which isn’t surprising given that their ancestors have lived in far-flung parts of the world for generations. Yet, everyone alive today can trace their origins back to Africa, so there must have been a time when such physical differences didn’t exist, right? Actually, no. In fact, if you were to travel back to the very beginnings of our species and select a random group of humans, they would look unlike anyone living today in Africa or elsewhere. What’s more, they would show extraordinary physical variation – greatly exceeding that in modern human populations. Far from becoming more diverse as we have adapted to life in different parts of the planet, Homo sapiens is more homogeneous today than our ancestors were. This is a real puzzle. It simply doesn’t fit with the long-held idea that we arose from a single population in a corner of East Africa. In fact, mounting evidence from fossils, archaeological remains and genetic analysis points in a new direction. Now researchers, including myself, are trying to work out what it all means: why our African forebears were so physically different from each other, and how our species lost the huge variety it once had.

4-25-18 How an Amazonian people convey their entire language by drumbeat
The Bora people can encode complex messages into drumbeats that mimic human speech, and even include a “ringtone” to announce the start of a message. An indigenous Amazon tribe can swap messages over 20 kilometres or more, simply by beating out rhythms on pairs of drums. It turns out the rhythms of the drumming mimic the entirety of their spoken language. The Bora people live in parts of Peru and Colombia. They use drums called manguaré. A pair of drums, each a cylinder about two metres long, sits on a wooden support. The drummer stands between the drums and beats each with a rubber-covered mallet in each hand. Each drum has a slit along its length, with a larger hole at each end. It can produce notes of two different pitches, depending which side of the slit the drummer bangs. Because one drum is bigger than the other, they have different pitches, giving four musical “notes” from each pair of drums. Julien Meyer of the University of Grenoble Alpes in France and his colleagues studied 169 messages sent by five expert drummers, in order to figure out how the messages convey information. “Speech is reduced to rhythm combined with two pitch levels,” says Meyer. They found that the different notes only play a minor role translating Bora language into “drum”. Instead, the key element is the rhythm of the drumming, which closely matches that of spoken Bora language. “In manguaré messages, the number of beats equals the number of syllables,” says Meyer. The lengths of the subtle pauses between beats were related to equal spaces in Bora spoken words. What’s more, certain beats identify nouns and others verbs.

4-25-18 Ancient Swedish massacre hints at chaos after the fall of Rome
The inhabitants of Sandby borg in southern Sweden were violently killed 1500 years ago, just decades after the collapse of the Western Roman Empire. An ancient Swedish fort is beginning to relinquish a dark secret it has held for 1500 years – that its walls bore witness to a brutal massacre. Although it’s unclear exactly what motivated the apparently merciless attack, it was probably linked to the chaos that swept across northern Europe following the collapse of the Western Roman Empire. Sandby borg on the island of Oland was an impressive ringfort in the late 5th century. Its walls stood 5 metres tall and enclosed a 5000-square-metre area that contained about 50 dwellings. Archaeological work began in 2010, but the ringfort is so rich in ancient finds that to date only about 6 per cent of the site has been excavated. Those excavations are revealing an extraordinary picture of violence and disorder. The remains of at least 26 individuals of all ages – including a baby and a young child – have been unearthed in the ringfort’s houses and streets. Many show signs of violent injury. They were seemingly slaughtered by invaders and left where they fell. “We anticipate that more bodies will be found,” says Ludvig Papmehl-Dufay at Kalmar County Museum, Sweden. “We’ve estimated that a fully inhabited fort of this size would have housed some 150-250 people. The total death toll may well be around those figures.” Papmehl-Dufay and his colleagues have also discovered valuables scattered around the site, including exquisite gold and silver artefacts and the remains of livestock. This suggests that the attackers weren’t opportunistic plunderers and may have had other motivations for their actions.

4-25-18 Clues to an Iron Age massacre lie in what the assailants left behind
No defensive wounds, valuables untouched, livestock left to starve point to a power struggle. Club-wielding assailants struck the Scandinavian settlement with devastating violence, slaughtering at least 26 people and leaving the bodies where they fell. There, the bodies lay for 1,500 years until recovered recently by archaeologists analyzing clues about the Iron Age massacre. It’s unclear why the seaside ringfort of Sandby borg, on the Baltic Sea island of land, was targeted at a time of political turmoil following the Roman Empire’s fall in Western Europe. Adults, teenagers and children died suddenly and brutally — their skeletons showing bones fractured by clubs, but no defensive wounds, say archaeologist Clara Alfsdotter of Bohuslns Museum in Udevalla, Sweden, and her colleagues. When the slaughter was over, the attackers left the sheep and other animals to starve and the valuables untouched, the scientists report in the April Antiquity. No one came back to bury the dead. That’s somewhat unusual: At most other excavated battlefield and massacre sites in Europe, bodies have been found in mass graves (SN: 1/23/16, p. 7). However, 67 farming villagers slaughtered around 7,200 years ago at Austria’s Asparn-Schletz site were also left in place. Circumstances surrounding the attacks on Asparn-Schletz and Sandby borg are poorly understood, making it difficult to compare the two events, says anthropologist Bruno Boulestin of the University of Bordeaux in France, who did not participate in the excavation.

4-24-18 Genetically modified plant may boost supply of a powerful malaria drug
Researchers tripled the amount of artemisinin naturally produced by sweet wormwood. Genetic modifications to a plant that makes artemisinin, a key compound used in malaria drugs, more than tripled the amount of the ingredient naturally produced in leaves. Previous attempts to genetically engineer Artemisia annua to increase the yield of artemisinin had failed. So Kexuan Tang, a plant scientist at Shanghai Jiao Tong University, and colleagues determined A. annua’s entire genetic instruction book and identified three genes crucial to artemisinin production. Genetic modifications to increase the activity of these genes boosted the artemisinin level in leaves from 0.1–1 percent of their dry weight to 3.2 percent, the researchers report April 24 in Molecular Plant. Malaria kills about 440,000 people worldwide every year. The scientists hope to save lives by increasing and stabilizing the global supply of artemisinin, which has been in shortage due to unstable supply, Tang says. Seeds of these modified plants have been shipped to Madagascar, which grows the most A. annua in Africa, as part of a field trial. “This is a milestone paper for artemisinin,” says Akhil Vaidya, an immunologist at Drexel University in Philadelphia who was not involved in the research. Artemisinin was discovered by Chinese chemist Youyou Tu in 1972, as she was investigating thousands of traditional Chinese remedies. The discovery, which has saved millions of lives, earned her the 2015 Nobel Prize in medicine (SN Online: 10/5/15)

4-24-18 GM plant tech boosts malaria drug yield
Scientists have modified a plant's genetic sequence to make it produce high levels of a key malaria drug, potentially helping meet the large global demand. The team identified genes involved in making artemisinin, altering their activity to produce three times more of the drug than "normal" plants make. The plant-based production of the drug sometimes fails to meet demand. The shrubs don't produce enough of the chemical in their leaves. The work appears in the journal Molecular Plant. "Nearly half of the world's population is at risk of malaria," said co-author Kexuan Tang of Shanghai Jiao Tong University. "Our strategy for the large-scale production of artemisinin will meet the increasing demand for this medicinal compound and help address this global health problem." The team produced a high quality draft of the Artemisia annua plant's genome and used this information, along with data on how genes are expressed, to engineer plants that produced high levels of artemisinin. The World Health Organization (WHO) says malaria affected about 216 million people in 91 countries in 2016, and caused an estimated 445,000 deaths worldwide that year alone. "Artemisia annua remains the sole source of the World Health Organization recommended treatment for malaria, which continues to be a devastating disease in the developing world," said Prof Ian Graham from the University of York, who was not involved with the study.

4-23-18 Complex life started a billion years earlier than we thought
Earth’s air suddenly got a lot more oxygen around 1.6 billion years ago and that could have triggered the evolution of large multicellular organisms. The first large, multicellular organisms seem to have appeared on Earth a billion years earlier than we thought – and their evolution may have been driven by a surge in oxygen. Until recently, the prevailing wisdom was that life made the leap from simple microscopic cells to large, complex organisms about 600 million years ago. This is when blob-like creatures called the Ediacarans appeared. They were thought to be the earliest beings to vaguely resemble today’s plants and animals. However, Chinese researchers overturned this idea in 2016 when they reported 1.6-billion-year-old fossils that looked remarkably like primitive seaweed. They were found in mudstone in the Gaoyuzhuang rock formation in China’s Yanliao basin. Their finely preserved structures revealed closely packed cells, arranged in elongated shapes up to 30 centimetres long and 8 centimetres wide. The fossils ignited vigorous debate. Some experts believed they were the first true plant-like organisms, but others said they were just colonies of bacterial cells. Many also questioned why complex life would have emerged at this time in Earth’s history. The Mesoproterozoic era, which began 1.6 billion years ago, has been labelled “boring” because it was apparently so uneventful. Now, Zhu Xiangkun at the Chinese Academy of Geological Sciences and his colleagues believe they can make sense of the find. Their research suggests that the Mesoproterozoic era was more action-packed than thought, because of a previously unknown shift in oxygen levels.

4-23-18 Worst mass extinctions may have been caused by rising mountains
A pair of mass extinctions struck in quick succession just before the dinosaur era, and the birth of a mountain range in South Africa may have been partly to blame. The birth of a mountain range in what is now South Africa may have helped to drive one of the most severe mass extinctions in Earth’s history. The Permian extinction struck about 252 million years ago. It’s traditionally thought to have wiped out at least 80 per cent of species in the sea and on land. Massive volcanic eruptions are thought to have played a major role. But in the last five years we have realised that another mass extinction happened not long before, roughly 260 million years ago at the end of the Capitanian period. Between 75 and 80 percent of all land animals vanished. It is still poorly understood, but the Capitanian extinction on land seems to have been far worse than the land die-off during the Permian extinction, says Spencer Lucas at the New Mexico Museum of Natural History. “The ecological severity of the extinction of the end-Capitanian dwarfs what happens at the end of the Permian,” he says. “I think what we’re going to find out, and this is my best hunch, is that the really important extinction was the end-Capitanian.” In other words, the Permian extinction may have been mostly in the sea, with most of the land extinctions happening during the earlier Capitanian event. The Capitanian event may also have ushered in the Permian disaster. It may have left ecosystems depleted, so life was still vulnerable when the volcanoes began erupting 6 million years later – helping to explain why the Permian extinction was so severe. The trouble is, nobody knows what caused the Capitanian extinction.

4-23-18 Informed wisdom trumps rigid rules when it comes to medical evidence
Systematic reviews emphasize process at the expense of thoughtful interpretation. Everybody agrees that medical treatments should be based on sound evidence. Hardly anybody agrees on what sort of evidence counts as sound. Sure, some people say the “gold standard” of medical evidence is the randomized controlled clinical trial. But such trials have their flaws, and translating their findings into sound real-world advice isn’t so straightforward. Besides, the best evidence rarely resides within any single study. Sound decisions come from considering the evidentiary database as a whole. That’s why meta-analyses are also a popular candidate for best evidence. And in principle, meta-analyses make sense. By aggregating many studies and subjecting them to sophisticated statistical analysis, a meta-analysis can identify beneficial effects (or potential dangers) that escape detection in small studies. But those statistical techniques are justified only if all the studies done on the subject can be obtained and if they all use essential similar methods on sufficiently similar populations. Those criteria are seldom met. So it is usually not wise to accept a meta-analysis as the final word. Still, meta-analysis is often a part of what some people consider to be the best way of evaluating medical evidence: the systematic review.

4-20-18 Scientists discover mechanism behind motor neurone disease
Scientists say they have made a breakthrough in understanding the cause of both motor neurone disease and a rare form of dementia. They have discovered what causes a protein called FUS to stay in a jelly-like state, killing off brain cells. The researchers, from Cambridge and Toronto, said they were cautiously optimistic their findings could one day to lead to improved treatments. The study is published in the journal Cell. Motor neurone disease (MND), also known as ALS, is a progressive and terminal disease that damages the function of nerves and muscles, resulting in severe damage to the brain and spinal cord. It affects up to 5,000 adults in the UK at any one time. Frontotemporal dementia is a form of dementia that causes changes in personality and behaviour, and language difficulties. Both conditions are caused by the death of brain cells and this study shows that a similar mechanism is involved in each. The researchers looked at a protein called FUS which is vital for nerve cells to work properly. It is able to change state between oily droplets and more solid jellies and in both diseases it can become trapped in its jellied form. Synapses - the point where two nerve cells meet - are highly active and need to produce a lot of new proteins in order for messages to be passed from one cell to the next. FUS grabs the instructions for those proteins as it becomes a jelly and releases them as it becomes an oil. In motor neurone disease, the FUS protein can be mutated and more prone to becoming stuck in a jellied form. In frontotemporal dementia, the problem is with other enzymes which help FUS change state, and they tip the balance towards the jelly.

4-20-18 Grandchildren of migrants more likely to get anxiety problems
People who migrate are at heightened risk of anxiety disorders, and these mental health problems may linger and get more severe through subsequent generations. Moving to a new country is a stressful experience, putting migrants at increased risk of anxiety disorders. But they aren’t the only ones who suffer: their children and grandchildren also experience more anxiety and higher rates of suicide than the general population. This might be down to the discrimination experienced by ethnic minorities, or to chemical markers of stress inherited through the generations. That’s what Baptiste Pignon at Public Assistance Hospitals of Paris and his colleagues have found after combing through health surveys collected from 38,694 people living in France. These included questions that screened for conditions like panic disorder, social anxiety disorder, generalised anxiety disorder and post-traumatic stress disorder (PTSD), as well as any history of suicide attempts. Pignon and his team compared the results of migrants with those from the native population. They also singled out responses from second and third-generation migrants: people whose parents and grandparents would be defined as migrants. After accounting for sex, age, income and education levels, Pignon’s team found that first, second and third-generation migrants were all more likely than the native population to experience anxiety disorders. Surprisingly, third-generation migrants have the highest rate of anxiety disorders, although it is unclear why. “The risk increased across the three migrant generations for social anxiety disorder and generalised anxiety disorder,” the team reports in its paper. Across the generations, migrants with anxiety disorders were also more likely to have psychotic disorders, bipolar disorder and addictive disorders, and had a higher rate of suicide attempts, compared with members of the native population with anxiety disorders.

4-20-18 Global cancer scheme lets people share data across the world
The Universal Cancer Databank will let anyone with cancer share their medical and genetic data with researchers globally, with the aim of speeding up new treatments. People with cancer will soon be able to donate their medical information to a global database aimed at discovering new treatments. Tessa Jowell, former UK Labour minister, who has a rare brain cancer, today became the first person to sign up to the database, called the Universal Cancer Databank. “It is my hope that through my cancer journey and sharing of my data, we will be able to develop better treatments for cancer and speed up the discovery of new ones,” said Jowell at the launch of the initiative in London. “Together, with hope, we can achieve greater survival for cancer patients across the world.” When the database becomes fully functional later this year, any individual with cancer will have access to a document – the “Universal Patient Consent Form” – that will allow them to make their medical and genetic data freely accessible to all cancer researchers. Ultimately, it is hoped that as many people as possible will donate their data, although the focus will initially be on people with rare cancers. The first project to utilise the database is a brain cancer clinical trial called GBM Agile, which will begin at the end of the year. The trial can be adapted as new information enters the database.

4-20-18 Antibiotic-resistant bacteria cross oceans hidden in cargo ships
Several types of dangerous bacteria, carrying genes that our antibiotics cannot fight, are travelling the world hidden in ships' ballast tanks. Cargo ships are spreading antibiotic-resistant bacteria around the world by carrying dangerous pathogens in their ballast tanks and expelling them near harbours. When researchers analysed the tanks of nine cargo ships originating from various countries, they discovered 44 species of potentially harmful bacteria in the sediment that accumulates within the tanks. DNA sequencing revealed ten antibiotic resistance genes within the samples. These genes can make bacteria resistant to medical interventions, meaning humans are more likely to die from them. In 2017, more than 50,000 commercial ships crossed the world’s oceans. When these ships pull into harbours to shift cargo, they expel or take on water into ballast tanks to provide stability. If this water contains antibiotic-resistant bacteria, these bacteria can travel around the world in weeks. Some of the bacteria identified in the study were already dead, suggesting that not all survive the journey from one country to the next. Baoyi Lv, an ocean engineer at Shanghai Maritime University in China, who led the study, points out that most of the harmful bacteria were so-called opportunistic pathogens, which are not dangerous to otherwise healthy humans.

4-19-18 Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past
The first draft of the true history of humanity has just been written and “it is thrilling in its clarity and scope,” said Peter Forbes in TheGuardian.com. Geneticist David Reich is a leader in the study of ancient DNA, and his new book synthesizes the findings with which he and others in the field have been upending prior conventional wisdom. Reich’s lab at Harvard Medical School was the source of the 2010 finding that all non-Africans have Neanderthal DNA in their genome, the first in a flurry of findings indicating that humans of about 50,000 years ago shared the planet and interbred with various other hominins. Further, our ancestors did not simply migrate out of Africa in a triumphant, ever-expanding tide. Instead, populations shifted one way, then the other, erasing almost every modern claim, outside of Africa, of a tie to a territory’s original settlers. “Reality, it turns out, is more complex and interesting than scientists ever imagined,” said Razib Khan in NationalReview.com. After explaining how geneticists learned in just the past decade to isolate and decode DNA in ancient human or hominin remains, Reich discusses what this new Rosetta stone has revealed. Consider Europe, which at the end of the last ice age was dominated by dark-skinned, blue-eyed hunter-gatherers who were then displaced about 10,000 years ago by migrant farmers from the Middle East, who also spread south into the Asian subcontinent. Some 5,000 years later, another wave arrived from the Russian steppe, linking Europeans genetically to Native Americans. In short, “we should stop obsessing with our individual ancestries,” said Bryan Appleyard in The Sunday Times (U.K.) “All humans are a hopeless genetic stew.”

4-19-18 Larger spleens may help ‘sea nomads’ stay underwater longer
DNA tests reveal the genetic underpinnings of this adaptation in the ethnic Bajau divers. In turquoise waters off the Indonesian coast, evolutionary geneticist Melissa Ilardo watched as the diver, wearing handmade, wooden goggles, spotted a giant clam meters below and darted down to retrieve it. The diver was one of the Bajau people of Southeast Asia, known for holding their breath for long periods while spearing fish and gathering other seafood. During a typical day, these “sea nomads” spend up to five hours in total underwater. And Ilardo had heard that some can hold their breath for as long as 13 minutes during a dive. Their comfort with breath-hold diving may be due to having unusually large spleens, which provides a bigger supply of oxygenated red blood cells, Ilardo and colleagues report online April 19 in Cell. “Many Bajau children learn to swim before they learn to walk,” says Ilardo, who did the research while at the University of Copenhagen. Certain seal species have larger spleens, and Ilardo wondered if the same was true for the Bajau. When a mammal holds its breath and dives, the body responds by slowing the heart rate, constricting blood vessels in the extremities and contracting the spleen to release stored oxygenated red blood cells.

4-19-18 Bajau people 'evolved bigger spleens' for free-diving
In a striking example of natural selection, the Bajau people of South-East Asia have developed bigger spleens for diving, a study shows. The Bajau are traditionally nomadic and seafaring, and survive by collecting shellfish from the sea floor. Scientists studying the effect of this lifestyle on their biology found their spleens were larger than those of related people from the region. The bigger spleen makes more oxygen available in their blood for diving. The researchers have published their results in the academic journal Cell. Located close to the stomach, the fist-sized spleen removes old cells from the blood and acts as a biological "scuba tank" during long dives. The Bajau people live across the southern Philippines, Indonesia and Malaysia and, according to rough estimates, number about one million people. "For possibly thousands of years, [they] have been living on house boats, travelling from place to place in the waters of South-East Asia and visiting land only occasionally. So everything they need, they get from the sea," first author Melissa Ilardo, from the University of Copenhagen, told the BBC's Inside Science programme. They are known for an extraordinary ability to hold their breath. "When they're diving in the traditional way, they dive repeatedly for about eight hours a day, spending about 60% of their time underwater. So this could be anything from 30 seconds to several minutes, but they're diving to depths of over 70m," said Dr Ilardo. Astonishingly, these deep dives are performed only with a wooden mask or goggles and a weight belt. Dr Ilardo explained that the spleen was an obvious candidate for studying potential adaptations to this aquatic lifestyle. (Webmaster's comment: Those with bigger spleens survive longer and breed more. It's that simple!)

4-19-18 Cutting calories for longevity
Eating less may help people live longer, reports CNN.com. Scientists at Louisiana State University tested the effects of calorie restriction on 53 healthy men and women between 21 and 50 years old. For two years, one-third of the volunteers ate their normal diet, while the rest cut their caloric intake by 15 percent. Unsurprisingly, those who consumed fewer calories lost weight—about 20 pounds on average. But they also saw another benefit: Their metabolic rate, which governs the amount of energy the body requires to sustain normal daily functions, slowed by about 10 percent during sleep. “It’s important because every time we generate energy in the body, we generate byproducts,” explains lead author Leanne Redman. These so-called free radicals accumulate and cause damage to cells and organs; this damage has been linked to diabetes, cancer, Alzheimer’s, and other age-related diseases. Previous studies have shown that reducing calories can extend life in rodents and other animals, but there has been little research to see if the same is true in humans. Redman now wants to examine the effects of reducing calorie intake over a much longer period.

4-19-18 The perils of a wealth shock
Suffering a major financial loss could lead to an early death, a new study suggests. Researchers at Northwestern University analyzed the financial history and health records of nearly 9,000 Americans between ages 51 and 61, from 1994 to 2014. During that period, about 25 percent of the subjects experienced a negative “wealth shock,” measured as a minimum 75 percent drop in their net worth over a two-year period. The median net-worth decrease was just over $100,000. The researchers found that the people who lost their nest egg were 50 percent more likely to die than their peers during the study period, and had the same risk of premature death as those who were poor or in debt. “This is something millions of people go through,” lead researcher Lindsay Pool tells Time.com. “It’s not really a rare event.” Pool and her team say a sudden reversal of fortune can lead to depression, high blood pressure, anxiety, and other health issues. People in financial turmoil may also have trouble affording their prescriptions and medical care.

4-19-18 Ancient footprints provide migration clue
Archaeologists have unearthed, on an island off Canada, what they believe are the oldest footprints in North America, boosting the theory that ancient humans first explored the continent by walking along the Pacific coast. Discovered beneath the dense forest and thick bogs of British Columbia’s Calvert Island, the 29 prints date back 13,000 years, to the end of the last ice age. The size of the tracks suggests they were left by two adults and a child, walking barefoot on the beach, reports The New York Times. They face inland, which may indicate that the small group was coming ashore after arriving on the island by boat. It is widely believed that humans first migrated to North America via a land bridge between Asia and Alaska. But because Canada was at the time covered by two giant ice sheets, it is unclear how these early settlers moved south. While some archaeologists believe they traveled through an “ice-free corridor” between the two sheets, the Calvert Island footprints suggest that other people ventured into the continent by hugging the Pacific coastline. “This line of research is really in its infancy,” says lead author Duncan McLaren, assistant professor of anthropology at the University of Victoria and the Hakai Institute in British Columbia. He and his team are now trying to locate the settlements where these coastal explorers lived.

4-19-18 Doctors who prescribe homeopathy ignore other medical guidelines
Family doctors who offer homeopathy - not recommended by the NHS - are also more likely to practice other bad habits such as the overuse of antibiotics. Doctors who prescribe homeopathy tend to flout a range of best practice guidelines. Primary care services that offer the alternative medicine to their patients are more likely to practice bad habits such as the overuse of antibiotics, according to a study of prescribing data. The UK’s National Health Service has been cutting down on use of alternative medicines for several years, with several bodies saying there is no good evidence to show that it works. Last year NHS England recommended doctors no longer prescribe any homeopathic or herbal remedies, although some GPs continue to do so. The British Homeopathic Association is taking NHS England to court to try to overturn its decision, with a judicial review set for 1 May. Defenders of homeopathy often claim that as these remedies tend to be relatively cheap, they avoid the use of more expensive conventional medicines. The latest study looked at all the 7618 primary care practices in England with data available on a website called Open Prescribing, which analyses use of medicines within the NHS. It was developed by Ben Goldacre of the University of Oxford and colleagues. Goldacre’s team found that 644 practices had issued one or more homeopathy prescriptions in a six-month period ending in 2017; these had slightly worse composite scores obtained by judging them on 70 standards of good practice in prescribing. The findings may reflect a lack of respect for evidence-based practice, says Goldacre.

4-19-18 A hole in an ancient cow’s skull could have been surgery practice
People may have been testing surgical techniques before operating on humans. Ancient surgeons may have practiced dangerous skull-opening procedures on cows before operating on people. A previously excavated cow skull from a roughly 5,400- to 5,000-year-old settlement in France contains a surgically created hole on the right side, a new study finds. No signs of bone healing, which start several days after an injury, appear around the opening. One or more people may have rehearsed surgical techniques on a dead cow, or may have tried unsuccessfully to save a sick cow’s life in what would be the oldest known case of veterinary surgery, researchers conclude online April 19 in Scientific Reports. Evidence of skull surgery on humans, whether for medical or ritual reasons, goes back about 11,000 years (SN: 5/28/16, p. 12). Ancient surgeons needed to know how and where to scrape away bone without harming brain tissue and blood vessels. So practicing bone removal on cows or other animals is plausible. The ancient cow’s skull opening, shaped almost in a square and framed by scrape marks, resembles two instances of human skull surgery from around the same time in France, say biological anthropologists Fernando Ramirez Rozzi of CNRS in Montrouge, France, and Alain Froment of IRD-Museum of Man in Paris. Microscopic and X-ray analyses found no fractures or splintered bone that would have resulted from goring by another cow’s horn. No damage typical of someone having struck the cow’s head with a club or other weapon appeared, either.

4-18-18 More education is what makes people live longer, not more money
As countries get richer, their citizens live longer. We’ve long thought that rising wealth was responsible for this, but it turns out education is the cause. When countries develop economically, people live longer lives. Development experts have long believed this is because having more money expands lifespan, but a massive new study suggests that education may play a bigger role. The finding has huge implications for public health spending. Back in 1975, economists plotted rising life expectancies against countries’ wealth, and concluded that wealth itself increases longevity. It seemed self-evident: everything people need to be healthy – from food to medical care – costs money. But soon it emerged that the data didn’t always fit that theory. Economic upturns didn’t always mean longer lives. In addition, for reasons that weren’t clear, a given gain in gross domestic product (GDP) caused increasingly higher gains in life expectancy over time, as though it was becoming cheaper to add years of life. Moreover, in the 1980s researchers found gains in literacy were associated with greater increases in life expectancy than gains in wealth were. Finally, the more educated people in any country tend to live longer than their less educated compatriots. But such people also tend to be wealthier, so it has been difficult to untangle which factor is increasing lifespan. They found that, just as in 1975, wealth correlated with longevity. But the correlation between longevity and years of schooling was closer, with a direct relationship that did not change over time, the way wealth does.

4-18-18 Mavericks are belittling statins – here’s why they’re wrong
Drugs designed to cut the risk of heart disease are being talked down amid a worrying lack of use by people who could benefit from them, says Anthony Warner. A WORRYING snapshot of flagging statin use has emerged. These controversial cholesterol-busting drugs are not being taken in many cases in which they could cut the risk of cardiovascular disease, the world’s biggest killer. Recent figures for England and the US show that many people who could benefit from the medicines are not getting them. At the same time, a highly vocal group, which includes a number of campaigning medics and self-styled researchers, are decrying the wider use of these drugs. Some of these critics have alternative diets and supplements to promote. They argue that statins are over prescribed, and that their side effects can outweigh the benefits. Although one in three people globally die from cardiovascular disease, in many nations efforts to cut the toll have helped. This is mainly thanks to increased knowledge of risk factors, especially smoking, high blood pressure and high blood cholesterol. Key among the innovations are statins, which have saved many lives since their introduction in 1987. These drugs partially inhibit enzymes that make cholesterol in the body, reducing levels of low-density lipoprotein (LDL, the so-called bad cholesterol). Which brings us to another anti-statin point of view. Some of the critics suggest that LDL cholesterol is not the villain it has been made out to be, and that its relationship to cardiovascular disease is overstated; this goes against a lot of evidence.

4-18-18 Bioengineered freckle turns darker when it detects cancer
An implant of genetically engineered skin cells has been designed to grow darker in colour when it detects early breast, prostate and colon cancers. A fake beauty spot could one day warn you of cancer. The implant, made of genetically engineered cells, has been designed to detect developing breast, prostate and colon cancers when they are only a few millimetres in size. Martin Fussenegger of the Swiss Federal Institute of Technology in Zurich and his colleagues made this implant by genetically altering human skin cells so that they would become darker in colour when exposed to rising calcium levels. A rise in calcium in the blood is often the first sign of a tumour, because nearly all breast, prostate and colon cancers release substances that break down bones, releasing calcium. The team programmed these skin cells to respond to rising calcium by producing the skin pigment melanin. They then put these cells into microscopic capsules and implanted these into the skin of mice that had been injected with breast or colon cancer cells. Within a few weeks, the implants had grown darker in all eight mice whose tumours raised their calcium levels. The implants did not change colour in mice injected with a different kind of cancer for comparison. If used for people, the capsules would probably need replacing every six months to a year, says Fussenegger. And if a black spot appears, it wouldn’t necessarily mean a person had cancer – raised calcium levels can also be caused by kidney problems and other conditions.

4-18-18 Keeping livers 'alive' boosts transplant success, trial finds
Keeping donated livers "alive" with a machine prior to transplants boosts the chances of a successful operation, a landmark trial has found. Usually livers are kept in ice prior before the surgery, but many become damaged and unusable as a result. For this study, scientists put them in a perfusion machine, pumping the organs with blood, nutrients and medicines. More of these "warm" livers went on to be transplanted and showed less damage than the "cold" ones, the trial found. Scientists said the study could help to reduce the significant proportion of people who die waiting for a new liver and potentially "transform" how organ transplants are carried out. The randomised controlled trial involved 222 liver transplants in seven European centres. It compared liver transplants where the organs were first preserved in an ice box with those kept "alive" outside the body using a so-called normothermic perfusion machine. Out of the 220 transplants scientists analysed, the study found there was 50% less tissue damage in the "warm" livers - a key marker of how likely the organ is to survive as well as the transplant patient themselves. Scientists were also able to successfully transplant more of the warm livers than cold ones. Just 16 out of 137 warm livers needed to be discarded compared with 32 out of 133 cold ones, meaning 222 transplants were able to go ahead. All but two were analysed by the team. Prof Peter Friend, one of the authors of the study in the journal Nature and one of the inventors of the machine, said currently about a third of donated livers could not be used for transplantation due to a range of factors.

4-18-18 Why touch can be such a creepy sensation in VR
Pairing tactile feedback with visual cues can keep the experience immersive, not jarring. There’s a fine line between immersive and unnerving when it comes to touch sensation in virtual reality. More realistic tactile feedback in VR can ruin a user’s feeling of immersion, researchers report online April 18 in Science Robotics. The finding suggests that the “uncanny valley” — a term that describes how humanoid robots that look almost but not quite human are creepier than their more cartoonish counterparts — also applies to virtual touch (SN Online: 11/22/13). Experiment participants wearing VR headsets and gripping a controller in each hand embodied a virtual avatar holding the two ends of a stick. At first, users felt no touch sensation. Then, the hand controllers gave equally strong vibrations every half-second. Finally, the vibrations were finely tuned to create the illusion that the virtual stick was being touched in different spots. For instance, stronger vibrations in the right controller gave the impression that the stick was nudged on that side. Compared with scenarios in which users received either no touch or even buzzing sensations, participants reported feeling far less immersed in the virtual environment when they received the realistic, localized touch. This result demonstrates the existence of a tactile uncanny valley, says study coauthor Mar Gonzalez-Franco, a human-computer interaction researcher at Microsoft Research in Redmond, Washington.

4-18-18 Getting just 6 hours of sleep is linked to mental health issues
You might think you can get by on 5 or 6 hours’ sleep a night, but people who get less than 7 hours are more likely to have mood or mental health problems. You might think you can get by on 5 or 6 hours’ sleep a night, but people who get less than 7 hours are more likely to have mood or mental health problems. A severe lack of sleep has been linked to mood disorders, depression, anxiety and Alzheimer’s disease. But much less is known about the effects of skimping on a little sleep each night, missing the recommended amount by an hour or so. According to the US National Sleep Foundation, most adults should get 7 to 9 hours of sleep a night, while 6 hours may be okay for some people. Anything under 5 hours is deemed insufficient. To find out the effect of low-level sleep loss on mental health, Kelly Sullivan and Collins Ordiah at Georgia Southern University analysed data from a telephone survey of over 20,000 people in the US. Respondents were asked about their sleep habits as well as their mood over the past 30 days. Around a quarter of participants said they got 6 hours of sleep or less, and these people were around 70 per cent more likely to report signs of mental health problems compared to those who got the recommended amount of sleep. Compared with people who slept between 7 and 9 hours a night, people who got less than 5 hours were three to four times more likely to say they experienced depression, nervousness, restlessness or feeling hopeless in the last month.

4-18-18 New blood pressure guidelines could do more harm than good
Millions of healthy people have been recast as “sick” under new blood pressure rules, which could trigger unnecessary anxiety and medication use. Last year, millions of people were reclassified overnight as having high blood pressure. The new limits, set by the American Heart Association and the American College of Cardiology, were intended to alert people to any rising blood pressure at an earlier stage, helping them to get on top of the problem sooner. However, the decision ignores the potential harms of slapping people with disease labels, according to an analysis published by Australian public-health experts on Monday. They estimate that up to 80 per cent of newly diagnosed individuals will end up worse off. These 80 per cent have less than a 10 per cent chance of having a heart attack or stroke in the next decade because they won’t have any other big risk factors besides elevated blood pressure. Nevertheless, it will still be a blow to be moved to the new category, with safe limits lowered from a blood pressure of 140/90 to 130/80 mmHg. Research has shown that being diagnosed with this condition can cause significant psychological distress. The disease label could also lead to unnecessary treatment. Although the new guidelines recommend lifestyle changes such as eating less salt, drinking less alcohol and exercising more for this relatively low-risk group, many will seek the reassurance of medication, which can have side effects like dizziness and nausea. Moreover, in countries like the US, being diagnosed with a medical condition like high blood pressure can affect insurance coverage and increase premiums.

4-17-18 This ancient Maya city may have helped the Snake King dynasty spread
Lidar maps and hieroglyphics suggest La Corona wasn’t so isolated after all. New insights into an ancient Maya kingdom are coming from a remote outpost in the Guatemalan jungle. Aerial laser maps, excavations and stone-slab hieroglyphics indicate that La Corona, a largely rural settlement, became a key part of a far-ranging Classic-era Maya kingdom that incorporated sites from southern Mexico to Central America, researchers reported on April 15 at the annual meeting of the Society for American Archaeology. Classic Maya civilization lasted from around 250 to 900. A dynasty of Kaanul rulers, also called Snake Kings, expanded their domain from their home city of Calakmul in Mexico by using La Corona as a relay center for precious stones and other goods from Kaanul-controlled sites farther south, said archaeologist Marcello Canuto. “Our work supports the idea that the ancient Maya formed interconnected political systems, not largely separate city-states as traditionally thought,” said Canuto, of Tulane University in New Orleans, who codirects the La Corona excavation.

4-17-18 A new plastic film glows to flag food contaminated with dangerous microbes
Adding the patch to meal packaging could help keep people from getting sick. Pathogen detectors built into plastic patches could someday spare you food poisoning. Carlos Filipe, a chemical engineer at McMaster University in Hamilton, Canada, and colleagues have developed a new kind of flexible film that’s coated in molecules that glow when they touch E. coli cells. This type of sensor also glows in the presence of molecules secreted by E. coli, so the material doesn’t have to be in direct contact with bacterial cells to flag food contamination. Sensors about the size of postage stamps fluoresced brightly when tested on tainted meat and apple juice, but not when the sensors touched unspoiled samples, the researchers report online April 6 in ACS Nano. Next, the scientists plan to make films that glow in the presence of other bacteria, such as Salmonella, says study coauthor Tohid Didar, a mechanical engineer at McMaster. Food packaging equipped with such microbe monitors could help curb the spread of foodborne illness, which kills about 420,000 people worldwide each year, according to the World Health Organization.

4-16-18 Catching malaria makes you smell more attractive to mosquitoes
Mosquitoes are particularly attracted to the sweat of people who have malaria, suggesting the parasite that causes it may change a person’s body odour. The tiny mosquito-borne parasites that cause malaria may also change the body odour of those they infect, making people more attractive to mosquitoes that spread it. It is well-known that some people seem to attract more mosquito bites than others. Past research has suggested that the chemicals found in body odour – which may be influenced by your genes or hormones – play a role in how attractive you are. Ailie Robinson at the London School of Hygiene and Tropical Medicine and her colleagues sought to find out which chemicals might be to blame. The team collected socks worn by Kenyan children, some of whom were infected with the parasite that causes malaria. In a test, they found that mosquitoes seemed to be more attracted to the socks worn by children with the parasite. When they later ran the experiment again, the mosquitoes were less attracted to these children’s socks once they had been treated for malaria, and no longer carried the parasite. This suggests that people with malaria are particularly attractive to mosquitoes. It’s possible that the malaria parasite has evolved a way to make us change our body odour, to attract more mosquitoes and help spread the parasite to others.

4-16-18 Dogs lived and died with humans 10,000 years ago in the Americas
Buried remains of the oldest known New World canines came from two sites in Illinois. A trio of dogs buried at two ancient human sites in Illinois lived around 10,000 years ago, making them the oldest known domesticated canines in the Americas. Radiocarbon dating of the dogs’ bones shows they were 1,500 years older than thought, zooarchaeologist Angela Perri said April 13 at the annual meeting of the Society for American Archaeology. The previous age estimate was based on a radiocarbon analysis of burned wood found in one of the animals’ graves. Until now, nearly 9,300-year-old remains of dogs eaten by humans at a Texas site were the oldest physical evidence of American canines. Ancient dogs at the Midwestern locations also represent the oldest known burials of individual dogs in the world, said Perri, of Durham University in England. A dog buried at Germany’s Bonn-Oberkassel site around 14,000 years ago was included in a two-person grave. Placement of the Americas dogs in their own graves indicates that these animals were held in high regard by ancient people. An absence of stone tool incisions on the three ancient dogs’ skeletons indicates that they were not killed by people, but died of natural causes before being buried, Perri said.

4-13-18 This is how norovirus invades the body
The pathogen targets a rare type of gut cell, a study in mice finds. How a nasty, contagious stomach virus lays claim to the digestive system just got a little less mysterious. In mice, norovirus infects rare cells in the lining of the gut called tuft cells. Like beacons in a dark sea, these cells glowed with evidence of a norovirus infection in fluorescent microscopy images, researchers report in the April 13 Science. If norovirus also targets tuft cells in humans, “maybe that’s the cell type we need to be treating,” says study coauthor Craig Wilen, a physician scientist at the Washington University School of Medicine in St. Louis. Worldwide, norovirus causes about 1 in 5 cases of acute gastroenteritis, an illness of vomiting and diarrhea accompanied by rapid dehydration. More than 200,000 people die annually from the virus, nearly all in developing countries. Norovirus even popped up at the 2018 Winter Olympics in Pyeongchang, South Korea, reportedly infecting around 275 people including a few competing athletes.

4-14-18 A high IQ may protect men from a cause of psychological stress
Men with higher intelligence scores seem less likely to develop psychological problems due to inflammation – but a high IQ doesn’t protect women in the same way. There’s more to intelligence than smarts – a high IQ seems to protect the brain from some of the effects of inflammation, including signs of depression. But the effect is only seen in men – perhaps due to hormonal differences. Inflammation – a heightened state of immune activity – has increasingly been linked to mental health in recent years. Studies have found that people with depression or schizophrenia seem to have higher levels of inflammatory proteins in their bodies, and anti-inflammatory drugs are currently being trialled for both conditions. But not everyone with high inflammation goes on to develop a mental health disorder. Eirini Flouri, at University College London, wondered whether intelligence may be one factor that helps protect some people from the effects of inflammation. Flouri and her colleagues analysed data from more than 9,600 people in the UK, aged between 18 and 97. Each person had answered surveys about their mental health, including whether they were in psychological distress. High distress scores indicate that a person is more likely to develop depression, says Flouri. The volunteers also provided blood samples, which were used to measure levels of inflammation. Each person also completed a battery of cognitive tests, which measured reasoning, memory and problem solving, among other things, to give an IQ score.

4-13-18 Tales of rampant suicide among Custer’s soldiers may be overblown
Few men killed themselves during the Battle of the Little Bighorn, skeletal data suggest. Historical accounts of the 1876 Battle of the Little Bighorn report that many of Gen. George Custer’s 7th Cavalry soldiers shot themselves to avoid being killed by Native American warriors after the crushing defeat. But a preliminary skeletal analysis, presented April 12 at the Society for American Archaeology annual meeting, suggests suicides were relatively rare among Custer’s overwhelmed forces. “No doubt suicides happened among Custer’s men, but perhaps not on the grand scale previously suggested,” said bioarchaeologist Genevieve Mielke of the University of Montana in Missoula. Just over 1 percent of the U.S. Army at that time, 268 soldiers, died in the battle in Montana. Mielke reviewed 30 written battle accounts taken from Native American fighters and army soldiers in nearby regiments, and found that 14 described instances of Custer’s men killing themselves with revolvers. Yet data on skeletal injuries of 31 of Custer’s soldiers indicate only three committed suicide by firing a gun into their head, Mielke reported. In contrast, 22 soldiers had skeletal damage consistent with dismemberment, scalping or other mutilations.

4-12-18 How to raise confident children
We shouldn’t have to clarify that it’s legal to let kids play without adult supervision, said Lenore Skenazy. But Utah just became the first state in the nation to pass a “free-range parenting” law, which says parents can’t be arrested for letting well-cared-for children go to the park by themselves, bike to school, or briefly stay at home alone. It seems crazy, but such arrests have occurred with increasing frequency. These days, people believe that unsupervised kids “are automatically in danger”—even though the crime rate is much lower now than when today’s adults were growing up. One explanation is a 24/7 news media that thrives on fear and bad news, making rare tragedies seem commonplace. But the biggest factor is “the illusion of control” parents have gotten from technology. Before smartphones, parents accepted that when kids went out the door, they were on their own and out of touch. Now, anytime you aren’t monitoring their every move, “you are making a conscious decision to opt out of your role as omniscient protector.” That creates fear and guilt. To make your children safe, make them “street smart”: Teach them how to cross the road safely and how to respond to creepy strangers. A child can’t grow up inside a cocoon.

4-12-18 The weekly alcohol limit still carries a risk of early death
An analysis of nearly 600,000 people found those drinking around five glasses of wine or pints of beer a week were at an increased risk of early death. An analysis of nearly 600,000 people found those drinking more than 100g of alcohol every week – around five 175ml glasses of wine or pints of beer – were at an increased risk of early death. The study analysed 599,912 current drinkers in 19 countries, none of whom had a known history of cardiovascular disease, and found an increase in all causes of death when more than 100g of alcohol was consumed every week. According to the analysis, a 40-year-old who regularly drinks between 200g and 350g of alcohol per week – about 10 to 18 glasses of wine or pints of beer – has a lower life expectancy of around one to two years. The findings support recently lowered guidelines in the UK, which recommend that both men and women should not drink more than 14 units or 112g of pure alcohol in a week. This equates to around six pints of 4 per cent strength beer or six 175ml glasses of 13 per cent wine. The study did find that the alcohol consumption is linked to a lower risk of non-fatal heart attacks, but that this is outweighed by the increased risk of other serious and potentially fatal cardiovascular diseases

4-12-18 Freezing the ‘hunger nerve’
Diets often fail as long-term solutions for many people trying to lose weight. But new research suggests that freezing the so-called hunger nerve could suppress hunger and be an effective new treatment for those struggling with obesity. When the stomach is empty, a branch of the vagus nerve called the posterior vagal trunk kicks into action, sending hunger signals to the brain. Guided by CT scan images, researchers used a probe to freeze this nerve in 10 obese women and men, with the aim of dampening its signal. “We’re not trying to eliminate this biological response, only reduce the strength of this signal to the brain,” the study’s lead author, David Prologo, tells ScienceDaily?.com. The preliminary results of the study suggest the nerve-freezing procedure may do just that. None of the subjects experienced side effects, but all of them reported feeling more satisfied and less hungry 90 days later. They also slimmed down. On average, the subjects lost 3.6 percent of their body weight and experienced a 13.9 percent drop in their body mass index (BMI). The researchers say their findings must be confirmed with larger, long-term studies.

4-12-18 Grilling causes inflammation
Regularly eating grilled, broiled, or roasted meat, chicken, or fish may increase the risk for high blood pressure, a new study shows. Harvard researchers came to this conclusion after analyzing the diet and cooking methods of more than 86,000 women and 17,000 men who were followed for up to 16 years. They found those who ate foods cooked by high heat more than 15 times a month were 17 percent more likely to develop high blood pressure than those who ate them less frequently. The people who preferred their meats well-done were also 15 percent more likely to become hypertensive, reports Reuters.com. “The chemicals produced by cooking meats at high temperatures induce oxidative stress, inflammation, and insulin resistance in animal studies, and these pathways may also lead to an elevated risk of developing high blood pressure,” says the study’s lead researcher, Gang Liu. Lowering the heat could help reduce these health risks. The researchers advise cutting back on barbecued burgers and fillets and opting for stewed, steamed, and poached meats and vegetables more often.

4-12-18 Why some cancers are 'born to be bad'
A groundbreaking study has uncovered why some patients' cancers are more deadly than others, despite appearing identical. Francis Crick Institute scientists developed a way of analysing a cancer's history to predict its future. The study on kidney cancer patients showed some tumours were "born to be bad" while others never became aggressive and may not need treating. Cancer Research UK says the study could help patients get the best care. "We don't really have tools to differentiate between those that need treatment and those that can be observed," said researcher and cancer doctor Samra Turajlic. One cancer could kill quickly while a patient with a seemingly identical cancer could live for decades after treatment. It means uncertainty for both the patient and the doctor. The work, published in three papers in the journal Cell, analysed kidney cancers in 100 patients. The team at the Crick performed a sophisticated feat of genetics to work out the cancer's history. It works like a paternity or ancestry test on steroids. As cancers grow and evolve, they become more mutated and, eventually, different parts of the tumour start to mutate in different ways. Researchers take dozens of samples from different parts of the same tumour and then work out how closely related they are. It allows scientists to piece together the evolutionary history of the whole tumour. "That also tells us where the tumour might be heading as well," said Dr Turajlic.

4-12-18 Discovery of a new organ?
A vast network of fluid-filled channels that surrounds muscle and lines the digestive, respiratory, and urinary tracts may be a previously undetected human organ, known as the interstitium, say scientists at New York University Langone School of Medicine. The researchers believe that this newly found structure, which appears to be an “open, fluid-filled highway,” serves as an internal shock absorber for other organs and also plays a major role in the immune system. Interstitial fluid is the source of lymph, which dispatches white blood cells to fight infections. The interstitium could help explain how cancer cells spread throughout the body. “Once they get in, it’s like they’re on a water slide,” the study’s co-author, Neil Theise, tells NewScientist.com. “We have a new window on the mechanism of tumor spread.” The interstitium holds about 20 percent of all the fluid in the human body, but it has evaded detection until now since tissue samples are typically dehydrated before being examined under a microscope. More research is needed to understand its role and determine whether it is indeed a distinct organ. Either way, Theise says, this discovery may lead to “a significant reassessment of anatomy affecting every organ of the body.”

4-12-18 Ancient Amazon settlements
Long before the arrival of Europeans, up to a million people thrived in large, complex villages buried deep within the Amazon rain forest. A team of archaeologists found 81 ancient settlements in the Upper Tapajós Basin, along Brazil’s border with Bolivia, NationalGeographic.com reports. The settlements, which are roughly 500 to 750 years old, challenge long-standing views of the Amazon as pristine wilderness. “There is a common misconception that the Amazon is an untouched landscape, home to scattered, nomadic communities,” says study author Jonas Gregorio de Souza. “This is not the case. We have found that some populations away from the major rivers are much larger than previously thought, and these people had an impact on the environment which we can still find today.” Satellite images reveal dozens of geoglyphs, or geometric-shaped trenches carved into the landscape. Ground surveys revealed abandoned stone tools, broken ceramics, buried trash, and terra preta—a type of charcoal-enriched, fertile soil made by ancient Amazonian civilizations.

4-12-18 Sweet potatoes might have arrived in Polynesia long before humans
Genetic evidence suggests the tubers were in the South Pacific more than 100,000 years ago. Sweet potatoes were domesticated thousands of years ago in the Americas. So 18th century European explorers were surprised to find Polynesians had been growing the crop for centuries. Anthropologists have since hypothesized that Polynesian seafarers had brought the tuber back from expeditions to South America — a journey of over 7,500 kilometers. New genetic evidence instead suggests that wild precursors to sweet potatoes reached Polynesia at least 100,000 years ago — long before humans inhabited the South Pacific islands, researchers report April 12 in Current Biology. If true, it could also challenge the idea that Polynesian seafarers reached the Americas around the 12th century. For the new study, the researchers analyzed the DNA of 199 specimens taken from sweet potatoes (Ipomoea batatas) and 36 species of its wild relatives. The goal, says plant geneticist Tom Carruthers of the University of Oxford, was to “gain insight into the origins of the sweet potato — when it arose, where it arose and how it arose.” Carruthers and his colleagues confirmed previous research that the sweet potato’s closest relative is the flowering Ipomoea trifida, which is similar to a morning glory. The genetic analysis shows that sweet potatoes originated from I. trifida at least 800,000 years ago, and then later interbred with I. trifida. It also shows that a specimen preserved from Captain James Cook’s 1769 expedition to the South Pacific is genetically different from South American sweet potatoes.

4-12-18 A virtual reality hand feels real after a zap to your brain
Will we ever be able to truly feel like we’re inhabiting a virtual world? A brain stimulation twist on the classic rubber hand illusion suggests we can. Will we ever be able to truly feel like we’re inhabiting a virtual world? A virtual reality twist on the classic rubber hand illusion suggests we can – and all it takes is a bit of magnetic brain stimulation. Around 20 years ago, psychologists in Pennsylvania discovered that they could convince people that a rubber hand was their own. They placed it on a table in front of a volunteer, and stroked it while simultaneously also stroking the person’s actual hand. The experiment inspired further “bodily illusion” experiments that mess with our sense of self in strange ways, giving us the feeling of “embodiment” – ownership of a body part that is not really one’s own. Now these illusions are going high-tech, and neuroscientists have managed to create embodiment using non-invasive brain stimulation, without actually touching a volunteer. “We wanted to know how much these illusions were based on the fact that you have to stimulate the body,” says Michela Bassolino, at the Swiss Federal Institute of Technology. Rather than stimulate a person’s hand by touching it, Bassolino and her colleagues used transcranial magnetic stimulation instead. Using a magnetic coil, they zapped magnetic pulses at each volunteer’s motor cortex – the part of the brain responsible for body movements. They did this while each volunteer was wearing a virtual reality headset, and zapped each person so that their hands twitched in time with the virtual hands they were watching.

4-12-18 Secrets of the sea bed: Hunt for Stone Age site in North Sea
British and Belgian scientists are exploring the sea bed off Norfolk hoping to find evidence that Stone Age people lived there when it was still dry land. In recent years, some trawler crews and researchers have found prehistoric animal bones and basic stone tools in North Sea sediment. The team on the Belgian ship RV Belgica aims to map the Brown Bank area, a sand ridge about 30km (19 miles) long. Mesolithic people are thought to have lived there in about 10,000-5,000BC. "We suspect that the bank is on the edge of a large prehistoric lake, where you would expect settlements," said Prof Vince Gaffney, an archaeologist at the University of Bradford. Despite the prehistoric finds from the North Sea bed, so far no Mesolithic settlement has been found in that vast area, which flooded after 6,000BC as the Ice Age glaciers retreated. Eventually the British Isles were cut off from the continent. When the coast of continental Europe reached as far north as Norway, at the end of the Ice Age, the sea level was about 120m (394ft) lower than today. "Areas under the North Sea now would have been the best to live in during the Mesolithic [period] - prime real estate, because the coastlines then had fish, birds, fresh water. But it is now terra incognita," Prof Gaffney said.

4-11-18 Ovarian cancer vaccine improves women’s survival rates
A personalised cancer vaccine that trains the immune system to attack tumours has had encouraging results in women with ovarian cancer. A personalised cancer vaccine that trains the immune system to attack tumours has had encouraging results in women with ovarian cancer. Ovarian cancer is one of the most common types of cancer in women – around 7,300 women in the UK are diagnosed with it each year. The disease often isn’t recognised until it has already spread, and even after successful treatment, there is a high risk of the cancer returning. Only half of women diagnosed with ovarian cancer survive for five years or more. Cancer vaccines have been showing promise in clinical trials, but few worldwide have made it into the clinic for routine use. Many of these vaccines are designed to train immune cells to recognise particular molecules that are often present in cancer cells, but this can fail because tumours vary between different people. To get around this problem, Lana Kandalaft from the University of Lausanne, Switzerland and her team have created personalised vaccines that are tailored to each individual tumour. To do this, they take samples from a woman’s tumour and kill the cells with acid, which exposes molecules that are normally hidden. These dead cells are then mixed with immune cells from the woman’s blood, and grown in the lab for a few days before being injected back into her.

4-11-18 Struggle to get up in the morning? You’re at risk of early death
A six-year study of nearly half a million people in the UK has found that people who were night owls were 10 per cent more likely to die during that time period. People who prefer to stay up late seem to have a greater risk of dying. A six-year study of nearly half a million people in the UK has found that people who were night owls were 10 per cent more likely to die during that time period. Kristen Knutson, of Northwestern University in Chicago, and her colleagues found that people who stayed up late had higher rates of diabetes, mental health disorders, and neurological conditions. They were also more likely to experience psychological stress, use drugs or alcohol, and not get enough exercise or sleep. The problem may be that people who are night owls have a body clock that fails to match their external environment, says Knutson. “They shouldn’t be forced to get up for an 8am shift. Make work shifts match people’s chronotypes – some people may be better suited to night shifts.” Knutson suggests people who struggle to get up early could help shift their body clocks by ensuring they are exposed to light early in the morning, but not at night. Having a strict bedtime and not leaving tasks until late in the day may help too, she says.

4-11-18 Making babies: How to create human embryos with no egg or sperm
Artificial wombs and embryos made from skin cells – remarkable new techniques could revolutionise reproductive biology and help bring an end to infertility. YUE SHAO wasn’t trying to create an embryo. But, a few years ago, working in a lab at the University of Michigan, he witnessed something mind-boggling. The cells he was working with seemed to assemble themselves into what looked just like an early-stage human. “We were looking for something else,” says Shao, a bioengineer now at the Massachusetts Institute of Technology – but “serendipity hit”. The idea that scientists could create the first steps towards human life is astonishing, but Shao’s discovery wasn’t the first. A year before he published his results in 2017, research by a team in Japan led to the birth of live mouse pups using eggs the team made from adult skin cells. Discoveries like these are bringing us closer to solving some of the most intractable problems in reproductive biology and medicine. By recreating these first days of development in the lab, researchers are breaking open the black box of early pregnancy, a poorly understood and fragile time at which most miscarriages happen and fertility treatments fail. Now 40 years after the birth of the first test-tube baby, the potential of these breakthroughs is heralding a new biological revolution, one that forces us to rethink what it means to reproduce and make a baby. And there’s a lot to consider. Imagine being able to conceive a child from someone’s skin cells, for instance – with or without their consent. Given the ability to make a human artificially, we need to decide whether we want to.

4-11-18 Your boss is probably to blame for meetings starting late
Half of all meetings start late – and your boss is probably to blame. A study found that meetings delayed just 10 minutes are likely to be less productive. Once meetings are delayed by 10 minutes or more, they’re likely to be significantly less effective – and it’s probably your boss who’s to blame. According to Joseph Allen, at the University of Nebraska Omaha, somewhere between 40 and 50 per cent of all meetings start late. “People hate it, but we seem destined to experience it about half the time,” says Allen. To investigate the effect this tardiness has on the meetings themselves, Allen and his colleagues put together a survey that asks questions about the last meeting someone attended. This survey was completed by 252 online volunteers who held jobs in a range of industries, including sales, retail, media, construction, IT and data entry. They found that 49 per cent of the meetings began on time, with 37 per cent starting 5 minutes late, and 14 per cent beginning 10 minutes late. Public sector jobs had the highest rate of late meetings, with 56 per cent failing to start on time, compared to 48 per cent in private companies. After a late start time, respondents were less likely to report that they had found the meeting satisfactory. But lateness only seemed to impact the effectiveness of a meeting once the delay reached around 10 minutes. Allen thinks this is because we get more upset when a meeting is later than usual. “Rather than get angry every time someone is late, we get angry when someone is egregiously late,” he says.

4-11-18 Quack cures: Why emotional support ducks may be a waste of time
We are increasingly seeking therapy in the companionship of ducks, dolphins and dogs. Anthrozoologist John Bradshaw says we are barking up the wrong tree. Daniel is framed in silhouette as he gazes out at the passing clouds through an aeroplane window. The picture went viral on social media in October 2016. It probably helped that Daniel is a duck, or more specifically, an emotional support duck. His owner says he helps her cope with post-traumatic stress disorder. In the US, an animal can often board a flight as long as a doctor has signed a letter stating it helps its owner deal with a medical condition. Delta Air Lines carried 250,000 such animals in 2017 – up 150 per cent on 2015. Most are dogs, but the increasingly exotic menagerie includes pigs, hamsters and peacocks. A recent rise in media reports about emotional support animals has brought me to John Bradshaw. He studies anthrozoology, or the ways in which humans and animals interact, at the University of Bristol, UK. I have come to find out if animals really can help people with mental illness, and if so, how? He shows me into a cosy attic study in his home, its shelves filled by books with titles including What It’s Like to Be a Dog and Feng Shui for Cats. Alongside them sit copies of Bradshaw’s own works Dog Sense and Cat Sense, which have together sold more than 400,000 copies. Here, Bradshaw tells me that there is almost no evidence for the claims made about animals and mental health, not just for emotional support animals, but virtually all forms of animal therapy – and even pets.

4-11-18 Species with big sex differences are more likely to die out
When sexual selection leads to extreme differences between sexes like the peacock's tail, it makes species more likely go extinct. The peacock’s tail may dazzle females, but can such extreme ornaments reduce males’ chances of surviving to such an extent that the whole species is far more likely to die out? Yes, says the most comprehensive study yet done. It was Darwin who realised that sexual selection by females can lead to the evolution of extreme traits in males– from colourful plumage to extravagant dances and displays – that reduce their overall fitness. Biologists have been arguing about how this affects the long-term survival of species ever since. Some think that species with extreme sex differences become more vulnerable to extinction, because extravagant male displays require lots of resources and make it harder to evade predators. The counter argument is that because it is harder for such males to survive, only those with the best genes get to pass them on, and that sexual selection can therefore speed up adaptation and make species more resilient. So who’s right? It’s a tricky question to answer by looking at living species, because they obviously haven’t gone extinct. So Gene Hunt at the Smithsonian Institution and his colleagues instead turned to the fossil record. They looked at 93 species of tiny crustaceans called ostracods, or seed shrimp, that lived around between 84 and 66 million years ago.

4-11-18 Colorful moth wings date back to the dinosaur era
New fossils reveal the structure of the ancient insects’ light-scattering scales. Tiny light-scattering structures that give today’s butterflies and moths their brilliant hues date back to the days of the dinosaurs. Fossilized mothlike insects from the Jurassic Period bear textured scales on their forewings that could display iridescent colors, researchers report April 11 in Science Advances. The fossils are the earliest known examples of insects displaying structural color — that is, color produced by light bending around microscopic structures, rather than light being absorbed and reflected as with a pigment or a dye. Structural color is common in bird feathers and butterfly wings today, but finding such features in the fossil record can be tricky. Scientists know very little about what the scales of ancient butterflies and moths looked like because that level of detail is preserved in very few fossils, says Conrad Labandeira, a paleoentomologist at the Smithsonian Institution in Washington, D.C., who wasn’t part of the work. For the study, paleobiologist Bo Wang and his colleagues spent three years examining more than 500 fossilized specimens from now-extinct lepidopterans. Most weren’t preserved well enough to still have scale remnants, says Wang, of the Chinese Academy of Sciences in Nanjing. But six Jurassic-era fossils did, the oldest of which was nearly 200 million years old. The researchers examined the microscale wing structures of these specimens under a scanning electron microscope, then used a computer program to figure out what color the wings would have appeared.

4-11-18 How ancient DNA is transforming our view of the past
Prof David Reich of Harvard Medical School is one of the leading lights in the field of ancient DNA. His team's work has cast a new perspective on human history, reconstructing the epic migrations and genetic exchanges that shaped the people of different regions worldwide. Here he explains how this revolution in our understanding unfolded. If it seems as if there has been an avalanche of recent headlines revealing insights into the travails of our ancient ancestors, you'd be right. From the fate of the people who built Stonehenge to the surprising physical appearance of Cheddar Man, a 10,000-year-old Briton, the deluge of information has been overwhelming. But this step change in the understanding of our past has been building for years now. It's been driven by new techniques and technological advancements in the study of ancient DNA - genetic information retrieved from the skeletal remains of our long-dead kin. At the forefront of this revolution is David Reich of Harvard Medical School in Boston Massachusetts. I met Prof Reich recently at the BBC while he was in the UK to talk about his book Who We Are and How We Got Here, which draws together the most recent scientific results in this field of study. The Harvard professor, who is 43, was recently highlighted by the journal Nature as one of 10 people who mattered in all of science for his role in transforming the field of ancient DNA from "niche pursuit to industrial process". Reich was raised in Washington DC, by parents who were distinguished in their own fields. His mother Tova is a novelist and his father Walter is a professor of psychiatry who also served as the first director of the United States Holocaust Memorial Museum.

4-11-18 The Nile river is at least 30 million years old
Sediment deposits reveal when the longest river in the world started flowing from Ethiopia to the Mediterranean. THE source of the Nile river remained a mystery to Europeans for thousands of years. Now another puzzle has finally been solved: the source of the river in deep time. The Nile had become a major river by around 31 million years ago, reports the first team of geologists to put a firm date on its origin. “The Nile’s the longest river in the world, and being able to figure out when it started is, for me, really exciting,” says Yani Najman at Lancaster University, UK, who led the team. Rivers carry sediment from their source down to the sea. So comparing the minerals in a river’s sediment deposits with the rocks found upstream reveals where its waters started out from in the past. The Nile’s story has remained elusive because its most ancient deposits are buried beneath thousands of metres of Nile delta sediment, says Najman. Only oil companies have drilled to such depths in the area and they don’t like to share their findings. But after years of negotiation, BP Egypt provided samples from delta sediments dated to about 31 million years ago. These contain minerals matching those in rocks in the Ethiopian Highlands – the place where one major branch of the river, the Blue Nile, gets going (Earth and Planetary Science Letters, doi.org/cm7r). That means the Nile was already flowing all the way from Ethiopia to the Mediterranean at least 31 million years ago. That is much older than some previous estimates. Studying the Nile’s origin is also revealing the geological history of the entire region. The findings mean the Ethiopian Highlands must have been uplifted around this time, too. “If you’re going to study rivers, you should look at them in their entirety,” says geomorphologist Martin Williams at the University of Adelaide in Australia. And that, he adds, is what Najman and her team did.

4-10-18 We can read memories by analysing brain gene activity
Memories have unique genetic signatures that reveal what they are. The finding could lead to ways to read and alter memories in people with PTSD or phobias. Memories have a unique genetic signature in the brain – a code that has only just been discovered and unlocked. The findings, in mice, suggest we may be able to read people’s memories by examining the patterns in their brains, and even one day alter or repair them to treat psychiatric disorders or memory loss. The brain seems to store memories in new connections between neurons. To do this, the neurons need to make new proteins – a process that is thought to be controlled by hundreds of genes. While investigating how this works, Ami Citri at the Hebrew University in Jerusalem and his colleagues discovered that particular experiences – be it an electric shock or a hit of cocaine – elicit different changes in gene activity in the brains of mice. These mice were given a variety of positive or negative experiences, such as electric shocks to their feet, a sugar treat, a dose of a chemical that makes them feel ill or cocaine. An hour later, they were euthanised and the team looked at which genes were being expressed in seven areas of the brain that are involved in memory, including the hippocampus and amygdala. Citri was surprised to find that all of the mice given cocaine, for example, showed the same general pattern of gene activity. The patterns were so clear that the team could guess what experience a mouse had been through with over 90 per cent accuracy just by analysing the levels of activity of different genes in their brains (eLife, doi.org/cm6w). While each experience had its own pattern, the signatures of the more positive experiences were relatively similar to each other, as were the negative ones, suggesting that bad memories and good memories are recorded differently.

4-10-18 Our eyesight is sharpest at twilight – and now we may know why
We see best at dawn and dusk, and this could be because our brain activity changes at these times, making it easier to distinguish signals from background noise. OUR sight is sharpest at dawn and dusk – and now we may know why. It is not a result of changes within our eyes, but of how the brain processes visual signals. The brain has continual background activity. But this lessens in the visual centres around sunrise and sunset, which may improve our perception of visual information in the low light levels at these times. “You are sensitising your brain,” says Christian Kell of Goethe University in Germany. “A weak signal coming in will have a higher signal-to-noise ratio.” Our eyes adapt to dim light in several ways, such as by the pupils dilating to let in more light rays. But irrespective of light levels, our eyesight gets better around the times of dawn and dusk. This has even been seen in people who lived for long periods in underground bunkers, cut off from natural light. To find out why, Kell’s team asked 14 men to spot when dim crosshairs flashed up on a screen at six different times of day. They also had their brains scanned, both as they did the task and while they rested. There were two noticeable peaks in their performance on the visual test: at 8.00 am and 8.00 pm, roughly corresponding to the time of sunrise and sunset (Nature Communications, DOI: 10.1038/s41467-018-03660-8). At these times, there was also a fall in background activity in three brain areas that process information from the eyes, ears and sense of touch. “We see a sensitisation of all the sensory areas of the brain,” says Kell. He thinks that is because people are more reliant on their vision and other senses in dim light. “Pre-industrial tribes are very active during dawn and dusk, which means they are also in danger from animals then,” says Kell. This could explain why we evolved to have sharper senses at these times.

4-10-18 Should you bank your baby’s umbilical cord blood? Here’s a guide for thinking through the issue.
There are a lot of factors to consider when deciding whether to bank your newborn’s umbilical cord blood. With the promise and pitfalls of umbilical cord blood samples in mind, how should parents decide whether to put their baby’s blood on ice, either for their own family’s future use or as a donation for the greater good? It’s a tricky calculation, one that changes based on a family’s risk threshold, dreams for the future and, of course, money. Instead of floundering about aimlessly, let’s start with the professionals. In 2015, the American College of Obstetricians and Gynecologists put out an opinion that, at this point, the science doesn’t support routine cord banking. As such, cord banking shouldn’t interfere with normal obstetric or neonatal care, including the timing of cord clamping. “The routine storage of umbilical cord blood as ‘biologic insurance’ against future disease is not recommended,” the authors of that opinion write. The American Academy of Pediatrics largely agrees. In a 2017 policy statement published in Pediatrics, the authors note that there is an “unquestionable need to study the use of cord blood banking,” but at this point, the uses are still limited. Medical professionals should acquaint themselves with the issues surrounding cord blood banking. (A 2008 survey suggested that only 18 percent of physicians felt confident discussing the pros and cons of public and private cord blood donation.) “Parents, not infrequently, are getting variable advice,” says pediatrician William Shearer of Baylor College of Medicine and Texas Children’s Hospital, who coauthored the AAP policy statement.

4-10-18 50 years on, vaccines have eliminated measles from the Americas
Excerpt from the April 13, 1968 issue of Science News. Mexico takes vaccine to hinterland: The campaign to eradicate measles in Mexico is going into the hinterland areas. Mobile brigades will use live virus vaccine produced in laboratories of the Republic’s Department of Health. Measles kills 10,000 Mexican children a year. — Science News, April 13, 1968. Update: The last measles case to originate in Mexico occurred in 1995. In 2016, the Pan American Health Organization declared that the Americas were measles-free, largely because of far-reaching vaccination campaigns. That year, 98 percent of Mexicans and 92 percent of Americans received at least one dose of vaccine, the World Health Organization and UNICEF estimate. Eliminating infections doesn’t mean a virus can’t be reintroduced. International travelers can bring measles in from other places. A 2017 outbreak in Minnesota saw 79 cases confirmed, many in a community with low vaccination rates, though the outbreak’s source was never identified.

4-10-18 More than half your body is not human
More than half of your body is not human, say scientists. Human cells make up only 43% of the body's total cell count. The rest are microscopic colonists. Understanding this hidden half of ourselves - our microbiome - is rapidly transforming understanding of diseases from allergy to Parkinson's. The field is even asking questions of what it means to be "human" and is leading to new innovative treatments as a result. "They are essential to your health," says Prof Ruth Ley, the director of the department of microbiome science at the Max Planck Institute, "your body isn't just you". No matter how well you wash, nearly every nook and cranny of your body is covered in microscopic creatures. This includes bacteria, viruses, fungi and archaea (organisms originally misclassified as bacteria). The greatest concentration of this microscopic life is in the dark murky depths of our oxygen-deprived bowels. Prof Rob Knight, from University of California San Diego, told the BBC: "You're more microbe than you are human." Originally it was thought our cells were outnumbered 10 to one. "That's been refined much closer to one-to-one, so the current estimate is you're about 43% human if you're counting up all the cells," he says. But genetically we're even more outgunned. The human genome - the full set of genetic instructions for a human being - is made up of 20,000 instructions called genes. But add all the genes in our microbiome together and the figure comes out between two and 20 million microbial genes. Prof Sarkis Mazmanian, a microbiologist from Caltech, argues: "We don't have just one genome, the genes of our microbiome present essentially a second genome which augment the activity of our own. "What makes us human is, in my opinion, the combination of our own DNA, plus the DNA of our gut microbes."

4-10-18 This material uses energy from ambient light to kill hospital superbugs
In lab tests, the quantum dot polymer nearly eliminated two drug-resistant strains of bacteria. A new material that harnesses the power of ambient light to produce bacteria-killing molecules could help stem the spread of hospital infections, including those with drug-resistant bacteria. About 1 in 10 patients worldwide get an infection while receiving treatment at a hospital or other health care facility, according to the World Health Organization. “Contaminated hospital surfaces play a key role in spreading those infections,” said Ethel Koranteng, a chemist at University College London on April 5 at the Materials Research Society spring meeting. Koranteng and colleagues developed a material to make hospital surfaces self-disinfecting. Naturally antimicrobial metals such as copper and steel are difficult to sculpt around uneven surfaces. But the new polymer-based material could be fashioned into a flexible film that covers computer keyboards, or molded into rigid, plasticlike casings that enclose phone handles, bedrails and other surfaces especially prone to contamination. Unlike other polymer-based antimicrobial coatings that rely on a spritz of water to release bug-killing particles, the new material is activated by overhead lighting (SN: 2/3/7, p. 75).

4-10-18 Ancient sea reptile was one of the largest animals ever
. Sea reptiles the size of whales swam off the English coast while dinosaurs walked the land, according to a new fossil discovery. The jaw bone, found on a Somerset beach, is giving clues to the ''last of the giants'' that roamed the oceans 205 million years ago. The one-metre-long bone came from the mouth of a huge predatory ichthyosaur. The creature would have been one of the largest ever known, behind only blue whales and dinosaurs, say scientists. The ancient jawbone was found near the village of Lilstock by fossil collector Paul de la Salle. He first thought it was a piece of rock but after seeing a distinctive ''groove and bone structure'' realised it might be part of an ichthyosaur. Dean Lomax, a world leading expert on ichthyosaurs from the University of Manchester, compared the bone with other specimens. ''It was a giant piece of mandible from an ichthyosaur,'' the palaeontologist told BBC News. ''We were mind blown to think that a sea creature the size of a blue whale was swimming off the English coast about 200 million years ago.''

4-10-18 Man in hospital after eating world's hottest chilli
A man who ate the world's hottest chilli pepper in a chilli-eating contest ended up in hospital after experiencing "thunderclap" headaches. The 34-year-old man had eaten one Carolina Reaper chilli in the contest in New York State. The "crushingly painful" headaches came on in the next few days. His experience has been published in the BMJ Case Reports as it is the first case to be associated with eating chilli peppers. The doctor who reviewed his case has warned anyone eating hot chilli peppers to seek medical attention immediately if they experience sudden onset headaches. "Thunderclap" headaches are caused by the sudden tightening of the vessels that supply blood to the brain, a condition known as reversible cerebral vasoconstriction syndrome (RCSV). Immediately after eating at the contest, the man experienced dry heaves. Severe neck pain developed over the next few days along with debilitating severe headaches, lasting just a few seconds at a time. The pain was so bad he went to the emergency room and was tested for various neurological conditions, but the results were negative. A CT scan showed that several arteries in his brain had constricted, leading doctors to diagnose him with RCVS.

4-9-18 World’s hottest pepper may have triggered this man’s severe headaches
Known as the Carolina Reaper, the chili can constrict arteries in the brain. Hot peppers aren’t just a pain in the mouth — they may be a pain in the head, too. After eating the hottest known pepper in the world, a man suffered from splitting headaches that drove him to the hospital emergency room, and into case-study history. His is the first known instance of reversible cerebral vasoconstriction syndrome — a temporary narrowing of arteries in the brain — to be tied to eating a hot pepper, researchers report April 9 in British Medical Journal Case Reports. Such narrowed arteries can lead to severe pain called “thunderclap headaches” and are often associated with pregnancy complications or illicit drug use. During a hot-pepper-eating contest, the man ate a chili dubbed the Carolina Reaper, named by Guinness World Records as the hottest pepper in the world. The Carolina Reaper is over 200 times as spicy as a jalapeño. About a minute later, he reported experiencing splitting headaches that came and went over two days before he sought treatment. Initial tests failed to find anything out of the ordinary. But a CT scan of blood vessels in the man’s brain showed severely narrowed arteries. After treatment, including hydration and pain medication, the headaches stopped. When the researchers imaged his brain five weeks later, the arteries had returned to their normal size.

4-9-18 Infections during pregnancy affect a child’s brain function
Contracting infections like flu during pregnancy seems to lead to changes in a child’s brain that affects their cognitive abilities. Studies that followed the health of pregnant women and their babies suggest that inflammation caused by infections like flu can lead to changes in the child’s brain, and that these may affect their cognitive abilities later on. The findings make it all the more important that pregnant women try to avoid infections, such as by getting vaccinated against flu and practising basic hygiene measures like hand-washing, says Bradley Peterson of the Children’s Hospital Los Angeles. Some microbes can directly infect a fetus during pregnancy, and cause developmental problems – Zika virus, for example, appears to be able to infect brain cells in the womb. But there’s some evidence that maternal infections might also affect fetuses indirectly, by putting the woman into a state of heightened immune system activity. For instance, there is evidence that there is a higher rate of schizophrenia among people who were born soon after the 1957 global flu epidemic. Some studies suggest flu may raise the likelihood of having a child who has schizophrenia from around 1 per cent up to as much as 7 per cent, and infections have also been linked to autism, attention-deficit hyperactivity disorder and depression. But these studies are not conclusive and there has been debate about whether infections in pregnant women really do affect the brains of their children.

4-9-18 One bad night’s sleep may increase levels of Alzheimer’s protein
A bad night’s sleep may lead to a protein linked to Alzheimer’s building up in the brain, but whether this raises the risk of the condition is unclear. Just one night of bad sleep may lead to more of a protein linked to Alzheimer’s disease building up in the brain. People with Alzheimer’s disease tend to have sticky clumps of beta-amyloid protein in their brains, although the role these plaques play in the condition is unclear. It’s possible this protein helps cause the condition, or instead that the protein forms plaques in the brain in response to the disease. Now researchers have found that one night of poor sleep has a detectable effect on the levels of beta-amyloid in the brain. Ehsan Shokri-Kojori, at the National Institutes of Health in Maryland, and his team discovered this by using a radioactive tracer to measure beta-amyloid in the brains of 20 volunteers over the course of two nights. For one of the nights, the participants were allowed a restful period of sleep, but they were deprived sleep on the other night. When scans were used to track the tracer, the team found that when sleep was restricted to only around five hours, beta-amyloid increased in two regions of the brain that are known to be vulnerable to damage in Alzheimer’s disease. These regions were the hippocampus, which is important for memory, and the thalamus, which helps relay signals in the brain and regulates sleep and consciousness. Sleep is thought to be important for clearing out waste from the brain, which may explain why people had more beta-amyloid in their brains after a bad night’s sleep.

4-9-18 Ancient finger bone may reveal humanity’s path out of Africa
A single bone found in the Saudi Arabian desert is at least 85,000 years old, and may shed light on the route early humans took out of Africa. A small finger bone found in the Saudi Arabian desert may rewrite a key part of the human story: how our species emerged from Africa and spread around the world. The bone is one of the oldest pieces of evidence of modern humans living outside Africa. Its discoverers argue that we must now reconsider our theories about when and how modern humans began spreading from our African birthplace. Huw Groucutt of the University of Oxford in the UK and his colleagues found the finger bone at a site called Al Wusta in what is now the Nefud Desert. It is the second bone in from the fingertip, but it’s not clear which finger. The team recognised the bone as human on sight, and later confirmed this by comparing it to finger bones of other humans, extinct hominins like Neanderthals, and other primates such as gorillas. They were able to date the bone directly, using precise techniques that rely on the decay of radioactive uranium. The team estimates the bone is at least 85,000 years old. For years, many archaeologists have believed that our species only left Africa around 70,000 years ago, and from there spread rapidly into Asia and Europe, and ultimately the Americas. However, that story has looked increasingly shaky due to a series of finds in the Levant: the area east of the Mediterranean that includes countries like Israel and Syria. It seems humans lived in this area over 100,000 years ago.

4-9-18 Finger fossil puts people in Arabia at least 86,000 years ago.
A desert discovery builds the case for humans’ early departure from Africa. A single human finger bone from at least 86,000 years ago points to Arabia as a key destination for Stone Age excursions out of Africa that allowed people to rapidly spread across Asia. Excavations at Al Wusta, a site in Saudi Arabia’s Nefud desert, produced this diminutive discovery. It’s the oldest known Homo sapiens fossil outside of Africa and the narrow strip of the Middle East that joins Africa with Asia, based on dating of the bone itself, says a team led by archaeologists Huw Groucutt and Michael Petraglia. This new find strengthens the idea that early human dispersals out of Africa began well before the traditional estimated departure time of 60,000 years ago and extended deep into Arabia, the scientists report April 9 in Nature Ecology & Evolution. “Although long considered to be far from the main stage of human evolution, Arabia was a stepping stone from Africa into Asia,” says Petraglia, of the Max Planck Institute for the Science of Human History in Jena, Germany. Don’t be misled by the vast deserts that dominate the Arabian Peninsula today. Geologic evidence indicates that Al Wusta lay within a well-watered, human-friendly area between around 95,000 and 86,000 years ago, the estimated age range for the human finger fossil, Groucutt and Petraglia’s team says. Dating relied on measures of the decay of a radioactive form of uranium in the human fossil and a nearby hippo tooth. Those results were combined with a measure of exposure to natural doses of radiation in the tooth. Another technique estimated the time since the finger bone and adjacent finds were buried by sediment.

4-9-18 Finger bone points to early human exodus
New research suggests that modern humans were living in Saudi Arabia about 85,000 years ago. A recently discovered finger bone believed to be Homo sapiens was dated using radio isotope techniques. This adds to mounting evidence from Israel, China and Australia, of a widespread dispersal beyond Africa as early as 180,000 years ago. Previously, it was theorised that Homo sapiens did not live continuously outside Africa until 60,000 years ago. The study is published in Nature Ecology and Evolution. Previous digs in the Arabian interior have uncovered tools which could have been used by early Homo sapiens. But skeletal evidence of their presence has been lacking. Researchers working at the Al Wusta site in Saudi Arabia came across a single intermediate phalanx (the middle of the three bones that make up a finger) in a preserved lake bed. No other remains of its owner were found. "It's normal," explained Dr Huw Groucutt, the study's lead author. "Almost all humans and animals that ever lived will disappear without trace. "We got very lucky. Generally if you found one piece of an individual you wouldn't be able to tell. But it turns out that bone is quite distinct," the University of Oxford researcher added. The team used CT scanning to build a 3D model of the bone, and compared it to other human and Neanderthal remains from this time period. It was found to most closely resemble Homo sapiens, as Neanderthal bones are shorter and squatter. Other material from the site was dated using two separate dating techniques.

4-9-18 Delusions of skin infestation may not be so rare
Researchers calculate the U.S. prevalence of ‘delusional infestation’. Delusional infestation: A deep conviction that one’s skin is contaminated with insects or other objects despite a lack of medical evidence. She was certain her skin was infested: Insects were jumping off; fibers were poking out. Fearful her condition could spread to others, the 50-year-old patient told doctors at the Mayo Clinic in Rochester, Minn., that she was avoiding contact with her children and friends. The patient had delusional infestation, explains Mayo Clinic dermatologist Mark Davis. Sufferers have an unshaking belief that pathogens or inanimate objects pollute their skin despite no medical evidence. Davis and colleagues report online April 4 in JAMA Dermatology that the disorder is not as rare as previously assumed. In the first population-based study of the disorder’s prevalence, the researchers identified 35 cases from 1976 to 2010 reported in Minnesota’s Olmsted County. Based on the findings, the authors estimate 27 out of every 100,000 people in the United States have delusional infestation. Due to the county’s lack of diversity — the population of about 150,000 is predominantly white — the researchers used only the nationwide white population to estimate prevalence, so the result may not be representative of other populations.

4-8-18 Fossils sparked Charles Darwin’s imagination
A new book recounts how discovering extinct species influenced his theory of evolution. Charles Darwin famously derived his theory of evolution from observations he made of species and their geographic distributions during his five-year voyage around the world on the H.M.S. Beagle. But in the introduction of On the Origin of Species, the naturalist also cites another influence: the thousands of fossils that he collected on that trip. Darwin’s Fossils is paleobiologist Adrian Lister’s account of that little-appreciated foundation of evolutionary theory. While sailors on board the Beagle charted the coastal waters of South America (the actual purpose of the expedition), Darwin explored the shore and rambled inland on excursions that sometimes lasted weeks. The fossils he unearthed — some relatively fresh, others millions of years old — have tremendous significance in the history of science, Lister contends. Many of the species Darwin discovered in the fossils were previously unknown to science, including several giant ground sloths, compact car–sized relatives of armadillos called glyptodonts (SN Online: 2/22/16) and ancient kin of horses and elephants. Because many of those animals were apparently extinct — but just as apparently related to species still living in the region — Darwin concluded the fossils were strong evidence for the “transmutation,” or evolution, of species. This evidence was all the more convincing to him, Lister suggests, because he had unearthed the fossils himself. He saw firsthand the fossils’ geologic context, which enabled him to more easily infer how species had changed through time.

4-6-18 Old people can produce as many new brain cells as teenagers
The discovery that healthy, older adults produce just as many new neurons as young people could provide clues to how to keep our brains sharper for longer. Old age may have its downsides, but losing the ability to grow new brain cells isn’t one: healthy people in their seventies seem to produce just as many new neurons as teenagers. The discovery overturns a decades-old theory about how our brains age and could provide clues as to how we can keep our minds sharper for longer. In mammals, most brain cells are created at or soon after birth and are not renewed. Recently, it was discovered that the human hippocampus, associated with learning and memory, produces new neurons throughout life. However, it was thought that this ability, called neurogenesis, severely declines after middle-age. To investigate, Maura Boldrini at Columbia University in New York, and colleagues removed the hippocampus from 28 people, aged between 14 and 79, soon after their death. They analysed the number of new neurons, the number of glial cells, which support neurons, as well as molecular markers that are expressed when brain cells form new connections or migrate around the brain – a sign of neuroplasticity. They found similar numbers of new neurons throughout the hippocampus, as well as comparable numbers of glial cells, regardless of the age of the person the sample had come from. The team estimates that each person was producing about 700 new neurons per day when they died.

4-5-18 Human brains make new nerve cells — and lots of them — well into old age
Previous studies have suggested neurogenesis tapers off or stops altogether. Your brain might make new nerve cells well into old age. Healthy people in their 70s have just as many young nerve cells, or neurons, in a memory-related part of the brain as do teenagers and young adults, researchers report in the April 5 Cell Stem Cell. The discovery suggests that the hippocampus keeps generating new neurons throughout a person’s life. The finding contradicts a study published in March, which suggested that neurogenesis in the hippocampus stops in childhood (SN Online: 3/8/18). But the new research fits with a larger pile of evidence showing that adult human brains can, to some extent, make new neurons. While those studies indicate that the process tapers off over time, the new study proposes almost no decline at all. Understanding how healthy brains change over time is important for researchers untangling the ways that conditions like depression, stress and memory loss affect older brains.

4-5-18 Brain-boosting beets
Beets may have a protective effect on the brain that could help ward off Alzheimer’s disease, new research suggests. Scientists at the University of South Florida found that betanin, the compound that gives the root vegetable its rich red color, could help prevent pro tein pieces called beta-amyloid from forming harmful plaque in the brain—a hallmark of the neurodegenerative disease. This plaque usually occurs when beta-amyloid binds to metals in the brain such as iron and copper; these metals cause the protein to form clumps that can trigger inflammation and oxidation, which destroys nerve cells. In a series of experiments, the researchers found that when beta-amyloid bound to copper was exposed to betanin, oxidation dropped by up to 90 percent. “This is just a first step,” co-author Li-June Ming tells the New York Daily News. “But we hope our findings will encourage other scientists to look for structures similar to betanin, [which] could be used to synthesize drugs that could make life a bit easier for those who suffer from this disease.”

4-5-18 This ancient lizard may have watched the world through four eyes.
A fossil of the monitor lizard’s skull reveals two holes for the photosensory structures. About 50 million years ago, a monitor lizard in what is now Wyoming perceived the world through four eyes. Saniwa ensidens is the only known jawed vertebrate to have had two eyelike photosensory structures at the top of the head, in addition to the organs we commonly think of as eyes, researchers report April 2 in Current Biology. The structures are called the pineal and parapineal organs. Among animals alive today, only the jawless fish called a lamprey has both structures. But many modern reptiles have a so-called third eye, the pineal organ. The researchers examined fossils collected 150 years ago by Yale University students. Scans of the fossils using a technique called X-ray computed tomography revealed spaces in the skull for both the third and fourth eye. What the ancient lizard did with these organs isn’t known, but some modern vertebrates use the amplified photosensitivity they glean from the pineal glands to navigate. S. ensidens may have been able to perceive polarized light and use the angle of the sun like a compass, as some modern lizards do. Or it may have navigated using Earth’s magnetic field, much like some amphibians and migratory birds

4-5-18 Video: How can a single pill treat HIV?
Formulating treatments containing three drugs against HIV in one single tablet has helped turn HIV into a manageable condition.

4-4-18 How medicine got too good for its own good
We’re detecting problems too early and convincing healthy people they’re sick – it’s time to rethink medical diagnosis, says physician H. Gilbert Welch. IN THE 1970s, H. Gilbert Welch drove an ambulance as a college job in Boulder, Colorado, often blaring out Elton John’s Someone Saved My Life Tonight. Wanting to save lives led him to study medicine, but he came to realise that saving lives wasn’t as clear cut as he thought. Sometimes, he found, it can be better to do nothing. Welch became a physician and academic researcher, and he has spent the last 25 years warning of the dangers of overzealous medicine. He worries that doctors are detecting problems too early, convincing healthy people they are sick, and treating them too aggressively. His latest research, published in December in the Journal of the American Medical Association, is a case in point. He has found that in US hospital regions with high rates of CT scans – which are typically ordered to check the lungs and abdomen – many more kidneys are removed. So what is going on? When doctors look at the images, they can see the kidneys too, and often stumble on innocuous cancers, says Welch. “It’s leading some people to be treated for disease that was never going to bother them.” And at significant risk: 1 in 50 of those who underwent the surgery died within a month. A professor at the Dartmouth Geisel School of Medicine who only stopped practising medicine five years ago, Welch has written three books highlighting unnecessary medical care, as well as dozens of journal articles and call-to-arms pieces in newspapers such as The New York Times. He travels the globe to speak to fellow doctors and researchers. With biomedical companies designing ever more tests, such as breath-tests for cancer, the problem seems poised to worsen. “It’s a very frothy industry right now,” says Welch.

4-4-18 Biology’s moonshot: The mission to decode the DNA of all life
A new plan to sequence all Earth's animals and plants could lead to medical and material advances that dwarf even what the Human Genome Project has achieved. Murphy is a “hunter-gatherer” – a biologist charged with cataloguing Earth’s rich array of plants and animals. For decades, he has plunged into the farthest-flung corners of the globe to find and collect new species. “It’s not for everyone,” he says. “People can end up with broken bones or malaria or puff up with insect bites, and the days are long and tough.” Indeed, the dangers can be life threatening. In 2001, Murphy’s friend and fellow collector Joe Slowinski died after being bitten by a venomous snake he had caught in Myanmar. Despite the risks, hunter-gatherers will soon be in high demand as an audacious scheme gets under way. This biological “moonshot”, known as the Earth BioGenome Project, is scheduled to launch in June. Its mission is to sequence the genomes of all known species of flora and fauna on Earth. Nature’s recipe books could hold clues to making far superior medicines, materials, biofuels and crops, unravelling our evolutionary past and help us to be better custodians of our planet. The first challenge, however, will be collecting specimens from the wild. Then comes the sequencing itself, which will require Herculean amounts of human labour and computing power. Can it be done? The Human Genome Project seemed equally far-fetched when it was proposed in the late 1980s. “There were many people who told us, ‘This is a waste of money, it’s way too costly’,” says David Haussler at the University of California, Santa Cruz. It cost $2.7 billion – or about $4.8 billion at today’s prices – and took over a decade to complete, but the treasure trove of information it unlocked has wildly exceeded expectations. Not only did it give birth to the personalised medicine revolution, it also propelled advances in diverse fields including forensics, archaeology and bioinformatics. Not to mention, every $1 of public money invested has since generated $141 in economic activity. “It’s paid for itself many times over,” says Haussler.

4-4-18 Miniature human brains with their own blood vessels grown in lab
Mini brains with a blood supply have been made in the lab for the first time. They may lead to a better understanding of the brain, and new injury treatments. Miniature human brains with their own blood vessels have been grown in the lab for the first time. The achievement could enable researchers to grow bigger organoids to better help us study and understand how the brain works. Organoids are small, 3D clumps of tissue that behave more naturally in the lab than traditional, flat cell cultures. Researchers use human brain organoids to explore how parts of our brain develop, but these seldom reach more than 2 millimetres in width because they have to be fed from the outside by a liquid containing growth factors and nutrients. If the organoids get too big, the centre dies, because not enough nutrients can reach them through diffusion, says Ben Waldau of the University of California at Davis. To overcome this, Waldau and his colleagues have created human mini-brains that are infiltrated with human blood vessels. Both the brain and the blood vessel tissue was grown from cells taken from the dura tissue that lines the brain, donated by a person undergoing a routine operation. By exposing cells to different chemical cocktails in the lab, the team encouraged some to become brain organoids, and others to become blood vessel cells. After a month, Waldau coated the brain organoids with a gel containing blood vessel cells. A month later, blood vessels had grown into the centre of the organoids. The next step is to see if this will enable brain organoids to grow bigger. The work could ultimately lead to ways to treat brain injuries, but this is still a long way off, says Waldau.

4-4-18 Newly discovered human organ may help explain how cancer spreads
A NEWLY discovered network of fluid-filled channels in the human body may be a previously unknown organ, and it seems to help transport cancer cells around the body. This discovery was made by chance from routine endoscopies, which involve inserting a thin camera into the gastrointestinal tract. Newer approaches enable doctors to get a microscopic look at the tissue inside a person’s gut, with some surprising results. One team using this technique to look at the bile duct had expected to find that it is surrounded by a hard, dense wall of tissue. But instead, they saw weird, unexplained patterns. They took their findings to Neil Theise, a pathologist at New York University School of Medicine. When Theise looked under the skin of his own nose with an endomicroscopy device, he saw a similar result. Further investigation of other organs suggested that these patterns are made by a type of fluid moving through channels that are everywhere in the body. Theise believes that every tissue in the body may be surrounded by a network of these channels, which essentially form an organ. The team estimates that the channels contain around a fifth of the total fluid volume of the human body. “We think they act as shock absorbers,” says Theise. This organ was probably never seen before because standard approaches for imaging human tissue cause the channels to drain, and the collagen fibres that give the network its structure to collapse. This would have made the channels appear like a hard wall of dense protective tissue, instead of a fluid-filled cushion.

4-4-18 Eye implant improves vision in people with age-related blindness
A patch of cells implanted at the back of the eye has stabilised and in some cases improved the vision of four people with dry age-related macular degeneration. A patch implanted at the back of the eye has improved or stabilised sight in four people with severe age-related macular degeneration. The treatment enabled one 69-year-old woman to read 24 letters on a standard eye chart, when she could previously manage only seven. The patch is made of eye cells made from human embryonic stem cells, and it has been designed for treating the “dry” form of macular degeneration, which accounts for 90 per cent of all cases, and affects 1.7 million people in the US. Similar patches and treatments have already been tested against the “wet” form – in which blood vessels invade and destroy the retinal pigment epithelial cells that nourish and support the photoreceptor cells that capture light. The “dry” form is caused by natural deposits on the retina that gradually kill retinal pigment epithelial cells. To treat it, Amir Kashani of the University of Southern California in Los Angeles and his colleagues made and transplanted a wafer-thin slither of polymer 6 by 4 millimetres in size that had been coated with healthy retinal pigment epithelial cells. Each of the four people had one eye treated, and one eye left untreated as a control. Over the course of the year-long trial, the patch appeared to stabilise the disease in all four treated eyes, while the untreated eyes continued to deteriorate. “A few patients also demonstrated some signs of improving visual function in the retina overlying the implant,” says Kashani. The team is now planning a larger trial in people who have earlier stages of the disease.

4-4-18 A new coronavirus is killing pigs in China
An unknown killer preying on pigs in China has been identified as a new kind of coronavirus. And like the deadly SARS virus, this one also got its start in bats. In late 2016, pigs mysteriously started having intense diarrhea and vomiting on farms in China’s southeastern Guangdong province. By May 2017, the disease had killed 24,693 piglets. Tests failed to pin the outbreak, which has since waned, on common pig viruses. By analyzing samples from sick piglets, researchers pieced together the genetic blueprint of the virus causing swine acute diarrhea syndrome, or SADS. It shares 95 percent of its genetic code with another coronavirus, HKU2, detected in cave-dwelling horseshoe bats in 2016. Evidence suggests these two coronaviruses share a common ancestor and that SADS jumped from bats to pigs, researchers report April 4 in Nature. No farm workers tested positive for SADS, so the disease doesn’t appear to infect humans. But the first documented human cases of SARS, or severe acute respiratory syndrome, emerged 100 kilometers from the pig farms hit by SADS. The study adds to evidence that keeping an eye on bat viruses could reduce future viral outbreaks — in pigs and humans.

4-4-18 When deciding whether to bank your baby’s umbilical cord blood, consider these caveats
Umbilical cord cells have exciting potential, but the promise may not be as advertised. Umbilical cords tie mother and baby together, if only for a brief spell. But the stuff inside these cords has the potential to be useful well after birth. Cells in umbilical cord blood are already being used to treat certain diseases, including leukemia and rare forms of anemia. But for all the excitement about umbilical cord cells, in many ways, this research is still in its infancy. Parents who are optimistic about that research future and want to save these cells have two options in the United States: Public not-for-profit cord banks and private cord banks. Here, about 30 public banks rely on donations from mothers, who don’t have to pay for the donation. After delivery, blood from the umbilical cord and placenta is collected, checked for quality, entered into a registry and then put in a deep freeze. And like the blood that’s collected in blood drives, these cells become available to anyone who might need them — not just the family that donated them. There is currently no shortage of willing donors. I was willing, but I wasn’t able to find a participating hospital and cord blood bank that could take my samples after my daughters’ births. “Public banks are not a moneymaking endeavor,” says Joanne Kurtzberg of Duke University, who helps run a public cord bank in North Carolina. As such, these banks have limited resources and can’t afford to take, test and store every possible sample. Kurtzberg estimates it costs public banks between $3,000 and $5,000 to collect a single unit.

4-3-18 Dinosaur tracks on Skye 'globally important'
New light has been shed on a little understood period of dinosaur evolution after giant prehistoric footprints were discovered on the Isle of Skye. Researchers, including some from Edinburgh University, have been analysing dozens of the footprints, left about 170 million years ago. They found that the tracks belonged to sauropods and therapods from the Middle Jurassic period. The discovery has been described as being "globally important". Few fossil sites have been found around the world from the Middle Jurassic period. The footprints, left in a muddy, shallow lagoon, are helping the researchers build a more accurate picture of an important period in dinosaur evolution. Most of the prints were made by long-necked sauropods - which stood up to 2m (6.5ft) tall - and by theropods, which were the older cousins of Tyrannosaurus Rex. Researchers measured, photographed and analysed about 50 footprints in a tidal area at Brothers' Point - Rubha nam Brathairean - a headland on Skye's Trotternish peninsula. The footprints were difficult to study owing to tidal conditions, the impact of weathering and changes to the landscape but the scientists identified two trackways in addition to many isolated footprints. Analysis of the clearest prints enabled scientists to ascribe them to sauropods and theropods. The study, carried out by the University of Edinburgh, Staffin Museum, and the Chinese Academy of Sciences, was published in the Scottish Journal of Geology.

4-2-18 Ardi walked the walk 4.4 million years ago
The pelvis of Ardipithecus shows the hominid could both walk upright and climb trees. A famous 4.4-million-year-old member of the human evolutionary family was hip enough to evolve an upright gait without losing any tree-climbing prowess. The pelvis from a partial Ardipithecus ramidus skeleton nicknamed Ardi (SN: 1/16/10, p. 22) bears evidence of an efficient, humanlike walk combined with plenty of hip power for apelike climbing, says a team led by biological anthropologists Elaine Kozma and Herman Pontzer of City University of New York. Although researchers have often assumed that the evolution of walking in hominids required at least a partial sacrifice of climbing abilities, Ardi avoided that trade-off, the scientists report the week of April 2 in the Proceedings of the National Academy of Sciences. “Ardi evolved a solution to an upright stance, with powerful hips for climbing that could fully extend while walking, that we don’t see in apes or humans today,” says Pontzer, who is also affiliated with CUNY’s Hunter College. Ardi’s hip arrangement doesn’t appear in two later fossil hominids, including the famous partial skeleton known as Lucy, a 3.2-million-year-old Australopithecus afarensis.

4-2-18 Estonia to give genetic testing and advice to 100,000 residents
Estonia is to become the first nation to give state-sponsored genetic advice on health and disease risks, and plans to extend the scheme to all its residents. The Estonian government plans to provide free DNA-based lifestyle advice for 100,000 of its 1.3 million residents. It will be the first nation to provide a state-sponsored personal genetic information service – but some have warned that this might cause unnecessary worry for those who find out they have an elevated risk for certain diseases. The goal of the initiative is to prevent or minimise future illnesses by giving forewarning to people whose genes put them at extra risk of conditions like cardiovascular disease and adult-onset diabetes. Given early warning, such people could then choose to adopt healthier lifestyles, and take preventative measures such as statin drugs, to reduce their risk of developing these conditions in the future. Each participant’s DNA will be analysed for more than 600,000 DNA variants that have been linked to common diseases. As well as heart disease and diabetes, the analysis will also screen for BRCA mutations linked to breast and ovarian cancer, and DNA variants associated with high cholesterol. The analysis will also look for more than 100,000 other variants that have been associated with rare diseases or adverse reactions to 28 common medicines, including warfarin, codeine, and some commonly prescribed antidepressents. The team behind the initiative hope to add other elements to the analysis in future.

4-2-18 How Amsterdam is reducing child obesity
Childhood obesity rates are rising in many parts of the world - but in Amsterdam they are falling. The city's healthy-weight programme has seen a 12% drop in overweight and obese children. "Go!" shouts the instructor. Tyrell van der Wees throws himself forward to do sit-ups, then jumps up and runs to the end of the gym and back again. He is breathing fast, his heart pumping. The nine-year-old is smiling, working hard and having fun. He is also part of Amsterdam's efforts to improve the health of its children. At the back of the gym Tyrell's mother, Janice, is sitting with other parents watching the fitness class. "He's really happy. He is doing something to improve his health. He knows the consequences and he is trying to do something about it," she says. A year ago Tyrell's school told Janice he was overweight. Children in Amsterdam are now regularly weighed and tested for agility and balance. Tyrell was referred to a child health nurse, Kristel de Lijster. She offered them a package of help including dietary advice, joining a gym class and a volunteer to make home visits - all for free. In a health centre in south-east Amsterdam, Kristel de Lijster explains how she helps families such as Tyrell's. "The most important thing is not to communicate in a standard way, because everybody already knows eating sugar and eating fast food is unhealthy," she says. "You really want to communicate the message on the level the parent and the child understands. "So, when the child is overweight it is more important for them to tell you what they think is going wrong."

4-2-18 DNA from another mystery human ancestor lingers in some people
Some modern Yoruba people in West Africa carry DNA that suggests an ancient species of hominin lingered longer than we thought. People in West Africa carry mysterious genes that may belong to another species of hominin. The finding hints that primitive hominins lingered in Africa until fairly recently. Our species repeatedly interbred with other hominins, in particular the Neanderthals and a less well-known species called the Denisovans. This happened after some members of our species first left our African homeland, probably within the last 100,000 years. As a result, all non-African people carry some Neanderthal DNA, and some Asian people also have Denisovan DNA. What about people whose ancestors never left Africa? They might also carry DNA from other species, but it is harder to spot because we do not have DNA from any extinct African hominins to compare: the hotter and wetter climate there tends to destroy any preserved DNA. To get around this problem, Arun Durvasula and Sriram Sankararaman at the University of California, Los Angeles devised a statistical method to identify out-of-place DNA in the human genome, without the need for the genome of the hominin from which it came. The model was able to correctly identify the known Neanderthal DNA in human genomes. They applied it to 50 Yoruba people from West Africa, who had had their DNA sequenced for the 1000 Genomes Project. On average, 8 per cent of their genome was from an archaic population. The mystery DNA was not Neanderthal, and nor did it match modern Pygmies who might plausibly have interbred with the Yoruba.

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