142 Evolution News Articles
for October 2018
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Nature cares only that you reproduce and raise the kids.
After you've done that, get out of the way.
10-31-18 Parkinson’s disease may start in the appendix and travel to the brain
Parkinson’s disease may start in the appendix, not the brain. People are less likely to get the condition if they had their appendix out decades previously. And a toxic compound found in the brains of people with this disease has now been spotted in the appendix. Parkinson’s, a degenerative condition involving tremors and stiffness, has long been thought to stem from the death of brain cells, caused by build up of a protein called synuclein that normally plays a role in nerve signalling. In people with Parkinson’s, synuclein is found in clumps that kill off nerve cells in parts of the brain controlling movement. When synuclein starts to aggregate in one place, the clumping spreads along nerves in a chain reaction. Evidence has been growing that this process may begin in nerves of the gut. For instance, if clumped synuclein is injected into the gut of mice, the toxic aggregates spread to their brains. Some previous studies have singled out the appendix as a key player in the onset of Parkinson’s. But research exploring whether having your appendix out protects against Parkinson’s has given contradictory results. The operation seems to be linked with a short-term slightly increased risk of the condition, but a lower risk over the longer term. So Viviane Labrie of the Van Andel Research Institute in Michigan, tackled the question with the largest and longest study to date, looking at the healthcare records of 1.6 million Swedish people over 52 years. Those who’d had their appendix out as young adults had nearly a 20 per cent lower chance of developing Parkinson’s in later life.
11-31-18 Neanderthals may have breastfed their young for more than two years
Neanderthal children were exclusively breastfed for nine months and fully weaned after the age of two, according to clues found in their teeth. Our Neanderthal relatives roamed Eurasia for thousands of years before going extinct about 40,000 years ago. To understand more about Neanderthal family life, Tanya Smith at Griffith University in Brisbane, Australia, and her colleagues studied two 250,000-year-old Neanderthal teeth found in the Rhone Valley in France. One tooth was a first molar that most likely formed soon after birth. The other tooth, which belonged to a second individual, was a second molar that probably developed around three years of age. The first molar showed high levels of barium – a sign of milk ingestion – in tooth layers from before nine months of age. Moderate levels were then seen up to about two-and-a-half years of age, before they sharply dropped off. The second molar had no elevated barium, suggesting that nursing had ceased by the age of three. Together, the findings suggest that Neanderthal mothers probably started introducing solids to their infants after nine months of exclusive breastfeeding, and then fully weaned them at around two-and-a-half, says Smith. This is similar to nursing patterns in modern humans living in hunter-gatherer communities. A study of 113 traditional societies found that on average, infants were introduced to solids after 5 months and fully weaned at 29 months.
10-31-18 Birds have their dinosaur ancestors to thank for their colourful eggs
From chocolate brown to brick red, emerald green to turquoise blue, bird eggs come in an astonishing variety of colours. And it all began with one dinosaur alive tens of millions of years ago, according to a new analysis that concludes colourful eggs evolved just once. Many living animals lay eggs, but only birds lay colourful ones. As such, biologists used to assume that colourful eggs are a bird innovation. But in 2015, Jasmina Wiemann, now at Yale University, and her colleagues discovered pigment molecules in 66-million-year-old dinosaur eggs. The eggs were blueish-green and were probably laid by some type of oviraptor, a bipedal dinosaur that’s a close relative of modern day birds. Now, the team has examined more dinosaur eggs. They have found evidence that seven more dinosaurs produced colourful eggs – again mostly blue-green. All seven dinosaurs belong to the Eumaniraptorans, a dinosaur group that includes giants like the 10-metre-long Therizinosaurus, as well as all birds. The team also looked for evidence of colourful eggs in a few dinosaurs that don’t belong to this group, but without success. They concluded that long-necked sauropods and duck-billed hadrosaurs probably laid plain white eggs, similar in colour to those of living turtles and crocodiles. This indicates that colourful eggs evolved just once, right at the base of the Eumaniraptoran dinosaurs, says research team member Mark Norell at the American Museum of Natural History, New York.
10-31-18 World's longest DNA sequence decoded
A team of UK scientists have claimed the record for decoding the world's longest DNA sequence. The scientists produced a DNA read that is about 10,000 times longer than normal, and twice as large as a previous record holder, from Australia. This research has kick-started an Ashes-style competition to sequence an entire chromosome in a single read. The new holder of the trophy for world's longest DNA read is a team led by Matt Loose at Nottingham University. The advance is a technological one - this is about reading the DNA rather than the discovery of a particularly large genome. The DNA used for the long read came from a human. But the scientists hope the work will make it quicker and easier to sequence genetic information because, currently, DNA has to be chopped up into smaller pieces and then reassembled during the process of sequencing. Dr Loose's group also recently produced the most complete human genome sequence using a palm-sized "nanopore" sequencing machine. These potentially offer lower cost and faster processing for DNA sequencing. He told me: "There has been a competition running to see who can get the longest sequence. I think it is still friendly." Dr Loose went on to say: "Australia led for a while, but then we had a read just short of a million. People were then competing to beat the record, in particular to be the first person to get a million-base-pair read. "The friendly completion launched an Ashes style trophy that is supposed to travel around the world as people get the longest read." An Australian team from the Kinghorn Centre for Clinical Genomics was first to pass the million-base milestone.
10-31-18 The appendix is implicated in Parkinson’s disease
Having an appendectomy lowered the risk of developing the neurodegenerative disease. The appendix, a once-dismissed organ now known to play a role in the immune system, may contribute to a person’s chances of developing Parkinson’s disease. An analysis of data from nearly 1.7 million Swedes found that those who’d had their appendix removed had a lower overall risk of Parkinson’s disease. Also, samples of appendix tissue from healthy individuals revealed protein clumps similar to those found in the brains of Parkinson’s patients, researchers report online October 31 in Science Translational Medicine. Together, the findings suggest that the appendix may play a role in the early events of Parkinson’s disease, Viviane Labrie, a neuroscientist at the Van Andel Research Institute in Grand Rapids, Mich., said at a news conference on October 30. Parkinson’s, which affects more than 10 million people worldwide, is a neurodegenerative disease that leads to difficulty with movement, coordination and balance. It’s unknown what causes Parkinson’s, but one hallmark of the disease is the death of nerve cells, or neurons, in a brain region called the substantia nigra that helps control movement. Lewy bodies, which are mostly made of clumped bits of the protein alpha-synuclein (SN: 1/12/2013, p. 13), also build up in those neurons but the connection between the cells’ death and the Lewy bodies isn’t clear yet.
10-31-18 Stimulating the spinal cord helps 3 more paralyzed people walk
Independent groups of scientists have now made similar progress using the therapy. Paralysis is becoming less permanent — at least for some. There’s now more evidence that stimulating the spinal cord can restore voluntary movement in paralyzed patients who haven’t recovered after other treatments. After five months of training coupled with targeted stimulation of nerve cells in the spinal cord, three people who had a severe spinal cord injury regained the ability to walk with varying degrees of support, researchers report online October 30 in Nature. Stimulating nerve cells, or neurons, in the spinal cord with electric jolts works by amplifing signals coming from the lower extremities, helping the brain and legs of paralyzed people to communicate better. But after undergoing the therapy, two of the patients were even able to walk on crutches without the electrical stimulation. That suggests that the treatment may have helped strengthen neural connections between the brain and spinal cord that were not functional or barely working post-injury. Such a level of recovery is “extremely exciting,” says Chet Moritz, a neuroscientist at the University of Washington in Seattle who wasn’t involved in the work. All three patients were paralyzed from an injury at least four years earlier, but hadn’t regained movement after extensive rehabilitation, despite having some neural connections remaining at the injury site. The finding comes on the heels of two other major studies published in September, one in the New England Journal of Medicine and one in Nature Medicine, showing similar gains in patients who had a form of paralysis where those connections were totally nonfunctional (SN: 8/27/18, p. 15).
10-31-18 The truth behind ASMR and the craze for videos causing ‘head orgasms’
Many people experience "ASMR", a relaxing sensation often triggered by gentle, whispering videos. We are finally working out what it is and that it can be good for you. A FEW years ago, I sat down in my home office and clicked through to a YouTube video. In it, a woman slowly folded towels on a table, while talking in a gentle whisper. Almost immediately, a warm, fuzzy tingle started around the nape of my neck, spreading across my shoulders and back. Within a minute, I was in a state of utter relaxation. The sensation lasted long after I stopped watching. I have experienced this calming tingle since I was a child, when my mother would stroke my back at bedtime. But I never mentioned it – it just seemed weird. Then a few years ago, I read an article about an internet subculture devoted to the “brain tingles” elicited by videos of people folding towels or The Joy of Painting – a TV show in which the host Bob Ross would produce an oil painting and quietly explain how he did it. Just reading the descriptions of these videos was enough to set off the sensation. Watching someone fold towels may seem tedious, but that clip has had more than 1,900,000 views. Clearly, I’m not alone. That got me wondering what was happening in my brain to elicit these feelings. Do they serve a purpose? And how many other people share my ability to easily find a state of blissful relaxation? The phenomenon first came to people’s attention in 2007, in an online forum thread titled “weird sensation feels good”. Many names were suggested, notably “attention-induced head orgasm” – a misnomer because the feeling is not as sudden or short-lived as an orgasm, and is distinct from sexual arousal.
10-31-18 There’s no evidence that screen time makes surgeons bad at their job
Surgical students are less capable than their forebears, due to spending too much time with screens and not enough with physical materials. These claims, from Imperial College London’s professor of surgical education Roger Kneebone, were widely reported this week. But it’s not clear that this is really the case. According to Kneebone, today’s students lack the manual dexterity that’s important for sewing, cutting and stitching. He argues that this is because, instead of taking part in creative subjects that involve working with their hands during their education, “a lot of things are reduced to swiping on a two-dimensional flat screen”. There hasn’t been much research yet into the effects of smartphones on hand skill, but one 2012 study found no statistically significant change in digital dexterity, and a significant improvement in reaction time, among frequent smartphone users. If anything, says Pete Etchells, a psychologist at Bath Spa University, UK, the use of digital technology – rather than smartphones specifically – seems to be linked with a higher level of surgical skill. One 2007 study, for example, found that young surgeons who played a lot of video games made fewer errors in surgery and worked faster than those who didn’t. A randomised, controlled trial in 2012 found that surgery simulators were less effective at training surgeons than just letting them play on games consoles. These were small studies that only found small effects, warns Etchells, but they don’t paint a picture of digital technology damaging the core skills of surgery.
10-31-18 Don’t teach kids – I’ve shown their hive mind can learn on its own
Educationalist Sugata Mitra's pioneering experiments suggest teaching facts doesn't work in the internet age – fostering creativity and collaboration is the key. IN 1999, an inquisitive physicist named Sugata Mitra installed a computer in a slum in New Delhi, India, and then walked away. Local children congregated and began trying to use the unfamiliar device. When Mitra returned a few days later, they had already taught themselves to surf the internet. Mitra is now a professor of educational technology at Newcastle University in the UK. In the decades since the “hole in the wall” experiment, he has found that groups of children aged 8 to 12, left alone with the internet, can teach themselves even technical subjects such as evolutionary biology to a level several years ahead of their school age. In 2013, he won a $1 million TED prize to help his work. The learning I’m talking about appears spontaneously in response to a query, which may be posed by an adult, or by the children themselves. I need the internet to be available on large, publicly visible screens in a safe space. I need to have mixed groups of children – boys and girls of different ages together, not each child on a different computer. Then I need to remove all supervision. We have got to keep the adults away. Everybody says, who taught them? How clever they are! But this doesn’t have anything to do with cleverness or teaching. It has to do with a hive-like mind with a common desire.
10-31-18 Eggs evolved color and speckles only once — during the age of dinosaurs
Analysis of pigmentation in the eggs of modern birds and nonavian dinosaurs suggests similarities. The colorful, speckled eggs of modern birds are an innovation inherited from their nonavian dinosaur ancestors. A new analysis of the pigmentation in modern and fossilized eggshells suggests that eggs evolved to be colorful only once — in modern birds’ dinosaur ancestors, a team of vertebrate paleontologists report online October 31 in Nature. Color patterns found in the eggshells of theropod dinosaurs, a lineage that includes Tyrannosaurus rex and smaller winged dinosaurs such as Microraptor, were very similar to those of modern birds, says Jasmina Wiemann, of Yale University. Scientists once thought only birds produced colorful eggshells, says coauthor Mark Norell of the American Museum of Natural History in New York City. But a growing body of literature suggests that many traits once thought to be unique to birds — feathers, flight, brain organization and adaptive metabolisms needed for flight — evolved long before modern birds did (SN: 4/14/18, p. 9; SN: 5/26/18, p. 8; SN Online: 10/19/18). “It’s kind of blurring the line between what’s a bird and what’s a [nonavian] dinosaur,” Norell says. Bird eggs get their color from two pigments: a red-brown pigment called protoporphyrin, which creates speckles and is found only in an eggshell’s soft, outer cuticle layer; and a blue-green pigment called biliverdin, found in the deeper, crunchier part of the shell. In 2015, Wiemann and her colleagues reported that fossilized eggshells of Heyuannia huangi, a short-beaked, crested dinosaur that lived about 70 million years ago, contained traces of both pigments (SN: 6/27/15, p. 14).
10-30-18 Scotland’s BSE case is a reminder that many more may be out there
Mad cow disease is down but not out. A case of bovine spongiform encephalopathy (BSE), the cattle infection that causes the lethal human brain disease vCJD, was confirmed on 18 October in the UK. The cow had died unexpectedly on a farm in Aberdeenshire, Scotland, so was tested under routine surveillance procedures. “The BSE case is a very unwelcome development of course, but not a complete surprise. The positive angle to this story is that our surveillance system is working,” says Mark Woolhouse at the University of Edinburgh. That cow, its offspring and any cattle of the same age on the farm have since been destroyed, meaning the “prion” – the misshapen protein that causes BSE – has been contained. But the case, 10 years after the last mad cow in Scotland, is a reminder of how BSE can lurk undetected, even when the cattle feed that spreads it is controlled to prevent prion contamination, and countries are actively on the lookout for fresh cases. The case itself is not surprising: a mathematical analysis in 2016 found that BSE could linger on in British cattle until 2025, with a few cases a year despite feed controls. Overall the BSE picture is actually looking good in the UK, where the disease began. However, many of the UK animals that have tested positive for BSE in recent years were infected by prions that arise spontaneously among cattle, rather than the prions that cause vCJD. The latest case was the second kind: it was what is now called “classical” BSE, which has so far killed more than 220 people worldwide. There have only been 76 classical BSE cases detected in the European Union since 2010.
10-30-18 How researchers flinging salmon inadvertently spurred tree growth
20 years of hurling dead fish into an Alaskan forest altered the local nutrient balance. How much salmon would scientists sling if scientists could sling salmon? For one research team, the question isn’t hypothetical, and the answer is … tons. During 20 years of monitoring salmon populations in one southwest Alaskan stream, ecologists have found and flung a total 267,620 kilograms of dead fish into the forest. Those rotting carcasses leeched enough nutrients to speed up tree growth, researchers report October 23 in Ecology. Some of the fish had died of old age, while many were torn apart by brown bears or gulls, says ecologist Thomas Quinn. He’s been counting salmon, both dead and alive, in Hansen Creek every year since 1997 with a rotating cast of students from the University of Washington in Seattle. For each dead fish, students catalogued the cause of death, then chucked the carcasses to one bank of the river to avoid double-counting. That toss is something of an art. The researchers use a gaff, a long pole with a hook on one end. The ideal motion is like a checked swing in baseball, when a batter starts to swing but instead lets the ball pass, Quinn says. If all goes well, the salmon carcass launches off the gaff in a graceful arc and lands far enough away that it won’t be washed back into the stream.
10-30-18 Neanderthals may have powered their bigger bodies by breathing deeper
The Neanderthal rib cage was subtly different in shape from our own – and that could help explain how the heavily built ancient humans grabbed enough oxygen from the air to survive. We now know a huge amount about Neanderthals – we’ve even gained some insights into their sex lives – but there are still gaps in our understanding. The precise shape of the Neanderthal chest (or thorax) is one of those gaps, says Asier Gómez-Olivencia at the University of the Basque Country, Spain. “Ribs and vertebrae are fragile and have a limited fossil record,” he says. But there is one Neanderthal specimen that does have most of its spine and rib cage preserved – a 60,000-year-old skeleton that belonged to an adult male. It is named “Kebara 2” and it was found in Israel in the 1980s. Gómez-Olivencia and his colleagues have now generated an accurate 3D reconstruction of the Neanderthal rib cage using Kebara 2 as a guide. We know that Neanderthals had bodies that were stockier than ours, which suggests that they burned more energy than we do. “Heavier bodies require a higher caloric intake and a higher oxygen consumption,” says Gómez-Olivencia. This has led researchers to assume Neanderthals had a bigger chest than we do, to hold larger lungs. But Kebara 2’s rib cage was the same size as ours. “This was one of the big surprises of the study,” says Gómez-Olivencia. The Neanderthal rib cage was, however, subtly different in shape. When viewed from the front, it is wider at the bottom than a typical modern human rib cage.
10-30-18 Chocolate: Origins of delicacy pushed back in time
Chocolate has been a delicacy for much longer than previously thought. Botanical evidence shows the plant from which chocolate is made was first grown for food more than 5,000 years ago in the Amazon rainforest. Chemical residues found on ancient pottery suggest cocoa was used as a food, drink or medicine by indigenous people living in what is now Ecuador. Until now it was thought that chocolate originated much later and in Central rather than South America. "The plant was first used at least 1,500 years earlier than we had previous evidence for," said Prof Michael Blake of the department of Anthropology at the University of British Columbia in Vancouver, a co-researcher on the study. "And that previous evidence was found in Mexico and Central America." Researchers analysed pottery vessels from the Santa Ana (La Florida) archaeological site in the highlands of Ecuador, which was occupied between 5,300 and 2,100 years ago. A number of crops have been documented there, including corn, sweet potatoes and the cacao tree Theobroma cacao. Traces of chemicals and DNA from the plant were found on pottery, suggesting the ground seeds of the cocoa pod were being mixed into a concoction and drunk. Co-researcher, Dr Sonia Zarrillo of the University of Calgary said grains of starch on the pot appeared to be "unique" to the cacao tree. The study corroborates DNA data pointing to the tree's origin in the upper Amazon region of northwest South America, which is where the domestic crop also originated. "It's another gift of the people of Amazonia to the world," said Prof Blake. "It highlights the importance of protecting this habitat." It is thought that seedlings or seeds of the cocoa tree were carried north into Mexico and Central America, perhaps along sea routes.
10-29-18 Ancient South Americans tasted chocolate 1,500 years before anyone else
Archaeological finds are the earliest evidence for cacao use in the world. Ancient South Americans domesticated and consumed cacao, the plant from which chocolate is made, long before other people did, a new study finds. Artifacts with traces of cacao suggest that an Amazonian culture located in what’s now Ecuador developed a wide-ranging taste for cacao products between 5,450 and 5,300 years ago, researchers report online October 29 in Nature Ecology & Evolution. Societies in southern Mexico and Central America, such as the Olmec and Maya, didn’t start concocting their better known and more intensively studied chocolatey drinks for roughly another 1,500 years. “This is not only the earliest archaeological evidence so far reported for cacao use in the Americas, but also the only archaeological evidence for cacao use in South America,” says study coauthor and anthropological archaeologist Michael Blake of the University of British Columbia in Vancouver. For more than a decade, reports of heightened genetic diversity among present-day domesticated cacao plants in South America’s upper Amazon region — near where the artifacts were found — have suggested that domesticated cacao (Theobroma cacao) originated there. Differences in the genetic makeup of related populations of organisms accumulate gradually, so populations displaying the most DNA diversity are presumed to have evolved first. The new study confirms that genetic scenario for cacao for the first time at an archaeological site.
10-29-18 People in the Pacific Northwest smoked tobacco long before Europeans showed up
Unearthed pipes reveal the earliest record of nicotine use in the region. Ancient pipes and pipe fragments found at five archaeological sites along the Snake and Columbia rivers in Washington contain evidence of tobacco use, new research shows. The finds suggest that indigenous people there smoked tobacco-filled pipes long before Europeans brought the plant west. Chemical traces of nicotine, tobacco’s key ingredient, on the artifacts date to around 1,200 years ago. That’s roughly 600 years before European fur traders were thought to have first introduced domesticated tobacco to Native Americans in the Pacific Northwest, researchers report online October 29 in the Proceedings of the National Academy of Sciences. Cultivated tobacco seeds from roughly 3,500 years ago have been found at archaeological sites in the southern United States, and evidence of the plant’s domestication in South America stretches back almost 8,000 years. But this is the earliest “biomolecular evidence of tobacco use anywhere in the Northwest,” says Shannon Tushingham, an anthropologist at Washington State University in Pullman. Tushingham and her colleagues used modern pipes to burn wild plants most likely smoked by early indigenous people. Those plants included bearberry, which is thought to have been widely smoked at the time, and some wild tobacco species, such as Nicotiana quadrivalvis, N. attenuata and N. obtusifolia. Using chemical signatures identified in those experiments, the team was surprised to find no traces of bearberry on the artifacts. But the scientists did detect measurable traces of nicotine, which could not be identified to the species level, in eight of 12 pipes and pipe fragments.
10-29-18 Crickets rapidly evolve new mating call to evade their parasites
In what could be a case of remarkably fast animal evolution, the crickets of Hawaii have begun to purr. The discovery is the latest twist in a decades-long battle between crickets and a parasitic fly that is attracted by their songs. Male crickets usually sing to attract a mate, but this makes the Pacific field crickets (Teleogryllus oceanicus) on Hawaii easy targets for a parasite. This fly (Ormia ochracea) tracks down crickets by their songs, and deposits its maggots on them. These then burrow inside their host, killing it. This strong incentive to stop singing meant that by around 1999, crickets on one Hawaiian island – Kaua’i – were evolving to stay silent. This was thanks to a mutation that gave males unusually flat wings, which stop them from producing a sound. By 2003, silent males made up about 90 per cent of the population – one of the fastest cases of evolution that has ever happened in the wild. Similar silencing has been detected on other Hawaiian islands. Researchers discovered, for example, in 2014 that crickets on the island of O’ahu have also evolved flat wings, but via a different genetic mutation. “It’s a really cool rapid convergent evolution story,” says Robin Tinghitella at the University of Denver in Colorado. But now, some crickets seem to be regaining their voice, and singing in new ways to escape detection by the flies. Studying crickets on the island of Moloka’i, Tinghitella and her colleagues have discovered males exhibiting what she describes as a “cat-like purr”. Analysing these crickets in the lab, the team found females are attracted by this call. But from what we know about the parasitic flies, the pitch of the call is probably too low for them to hear.
10-28-18 Creams remove skin sun spots with minimal pain and may prevent cancer
Brown spots on skin caused by sun exposure can be removed using medicated creams, a process that may help prevent future cancers. Actinic keratoses – also known as sun spots – are brown or pink scaly marks caused by UV rays. In the past, it’s been possible to have sun spots removed by freezing them off with liquid nitrogen, but the pain associated with this procedure meant that only one or two could be taken off at a time. But a range of creams are now enabling people to remove dozens of sun spots at one time from their faces, forearms or elsewhere, with minimal pain. The most effective of these – a cream based on aminolevulinic acid – can remove 80 per cent of a person’s sun spots in one go, according to a recent study led by Janne Räsänen at the University of Tampere in Finland. After aminolevulinic acid is applied to the skin, it is rapidly absorbed by sun spots and reacts to form a chemical called protoporphyrin IX. Patients must keep the cream on for two hours while sitting in sunlight, which triggers protoporphyrin IX to release molecules called reactive oxygen species. These cause the cells in the sun spots to die and ultimately fall off. The treatment is normally applied once and it works quickly, says Stephen Shumack at the University of Sydney in Australia. “You look like you’ve had a bad sunburn for the first few days, then the skin gets scabby and crusted over and the sun spots peel off within a week,” he says. “The skin looks a lot better afterwards – it becomes very smooth,” says Shumack.
10-28-18 Huddling for warmth gives animals a more efficient gut microbiome
Winter is coming, for the northern hemisphere at least. While many of us dig out our blankets and fleeced socks, some animals go searching for each other. Many small mammals huddle together to keep warm when the temperature drops. It now turns out that this huddling behaviour changes the composition of bacteria in the animals’ guts – and it does so in a way that slows down their metabolism and helps them preserve energy. Huddling is a strategy many animals deploy to maintain body temperature in cold weather. The benefit of such behaviour is obvious: nestling in a group reduces the body area exposed to the cold air, and thus reduces heat loss. But Dehua Wang at the Chinese Academy of Sciences in Beijing and his colleagues suspected huddling might have additional benefits at a deeper level – particularly since some studies have found that animals in a huddle have surprisingly similar gut bacteria profiles. This finding suggested to Wang that huddling might influence an animal’s gut microbiome profile, so he decided to investigate. Wang’s team put voles in a room at a chilly 4 C. They placed some of the voles in a single cage so they could huddle together for warmth, while others were housed individually. After the voles had endured the chilly temperatures for three weeks Wang and his colleagues extracted gut bacteria from the huddling and isolated voles. They used antibiotics to sterilise the guts of another 12 voles kept at room temperature, and then seeded 6 of them with ‘huddling’ vole gut bacteria and the other 6 with ‘isolated’ vole gut bacteria. They found those with huddling vole bacteria in their guts consumed 15 per cent less food – and had a 20 per cent lower resting metabolic rate – than those with isolated vole bacteria in their guts. This suggests huddling encourages changes to the vole gut flora that then slow down the hosts’ metabolism. A slower metabolism will help them conserve energy through cold spells when finding food might be challenging.
10-26-18 What the approval of the new flu drug Xofluza means for you
A new single-dose treatment gives doctors a novel way to fight influenza infections. There’s a new flu drug on the shelf, the first in 20 years to get a thumbs-up from the U.S. Food and Drug Administration. On October 24, the agency approved the use of the new antiviral drug, called baloxavir marboxil and sold under the brand name Xofluza. The drug, already available in Japan, works differently to kill the influenza virus from the other main class of flu antivirals, which includes the drug Tamiflu. Antiviral drugs can help alleviate symptoms and shorten the flu’s duration, although flu vaccination remains the best way to prevent illness and death caused by the virus. “Prevention is better than treatment in all things and that’s absolutely true for flu,” says infectious disease physician Andrew Pavia of the University of Utah School of Medicine in Salt Lake City. “So the first message is: Get your flu shot.” Many people aren’t getting that message: The U.S. Centers for Disease Control and Prevention reports October 25 that less than 40 percent of adults got a flu shot last year, the lowest amount in at least eight seasons. The 2017–2018 season in the United States was particularly deadly; about 80,000 people died of flu or related complications (SN Online: 9/27/18). The recent bad flu season highlights the importance of having ways to treat the flu, in addition to preventing it. The approval of the new drug is “kind of a big deal in terms of our overall arsenal against flu,” Pavia says.
10-26-18 Fewer kids vaccinated
The percentage of American children ages 2 and under who haven’t received any vaccinations has quadrupled over the past 17 years, a worrying sign of the “anti-vax” movement’s success. In 2017, 1.3 percent of kids born in 2015 had received none of the recommended vaccines, according to a new report by the Centers for Disease Control and Prevention, up from 0.9 percent for those born in 2011. In 2001, only 0.3 percent of children ages 19 to 35 months were totally unvaccinated. The agency notes “that most children are still routinely vaccinated” and that immunization rates haven’t changed nationally. But if kids born in 2016 were vaccinated at the same rate as those born the previous year, that means there are now some 100,000 children nationwide who aren’t inoculated against preventable diseases such as measles, whooping cough, and hepatitis B. “This is something we’re definitely concerned about,” Amanda Cohn, the CDC’s senior adviser for vaccines, tells The Washington Post.
10-26-18 A mysterious polio-like disease
The Centers for Disease Control and Prevention is warning the public about a surge of cases of a rare and mysterious polio-like disease that mostly affects children and can result in paralysis. The agency said last week that it had confirmed 62 cases of acute flaccid myelitis (AFM) across 22 states since the start of the year, reports CBSNews.com. More than 90 percent of those were in children, with the average sufferer being 4 years old. Another 65 possible cases are under investigation. Health officials have been closely monitoring the disease since 2014. Every year since then, normally in late summer, there has been a spike in cases—a pattern that has left researchers baffled. Scientists are still uncertain how AFM, which affects the nervous system, is transmitted. Symptoms include weakened muscles and reflexes, and in some cases paralysis; one child with the disorder died in 2017. Nancy Messonnier, a top official at the CDC, emphasized that the disease was still extremely rare. But she said the agency wanted to raise awareness of the condition and encourage parents to seek immediate medical care if their kids showed any weakness or loss of muscle tone in their limbs.
10-26-18 Supplements’ hidden perils
Hundreds of dietary supplements sold in the U.S. contain unapproved and potentially dangerous ingredients. That’s the conclusion of a new analysis of the Food and Drug Administration’s “tainted products” database, reports CNN.com. Researchers from the California Department of Public Health found that from 2007 to 2016, the FDA recorded 776 dietary supplements containing unlisted ingredients that were either unsafe or unstudied. Nearly 46 percent of the tainted supplements were for sexual performance, 41 percent for weight loss, and 12 percent for muscle building. The hidden ingredients included sibutramine, which is banned in the U.S. because of cardiovascular risks, and anabolic steroids, which when taken in excess can cause mental health problems and liver and heart disease. Yet in most cases, the FDA didn’t order product recalls—only 360 of the tainted products were taken off the shelves. Because dietary supplements are classified as foods, not drugs, they aren’t subject to the same rigorous premarket testing as pharmaceuticals. With the supplement industry now worth $35 billion, the study authors say it is “essential to further address this significant public health issue.”
10-26-18 Human beings are hardwired for tribalism
“Human beings are hardwired for tribalism. We compulsively (and unconsciously) divide the social landscape into in-groups and out-groups; selectively process information that affirms the virtues of the former and the vices of the latter; and allow our self-esteem to rise and fall with the status of our team. Most Americans do not develop an intellectual attachment to some abstract philosophy of government and then join the party whose platform best represents their theory of the state. Rather, the average voter is born into a variety of social groups (a religion, a ‘race,’ a class, etc.), and then joins whichever party appears to best represent her people.”
10-26-18 A mouse with two moms—and no dad
Scientists in China have bred healthy mice with two mothers and no father, a gene-editing breakthrough that carries both promise and significant ethical concerns. The researchers wanted to find out why some species of reptiles, amphibians, and fish can reproduce without genetic input from a male but mammals cannot. The barrier for mammals is a phenomenon known as imprinting, in which for about 100 genes, only the copy that comes from the mother or the father is switched on. Offspring that don’t receive genetic information from both a mom and a dad can experience severe developmental abnormalities. To work around this, the Chinese team took embryonic stem cells from a female mouse and deleted maternal imprinting from some of the genes using the DNA editing technology CRISPR. The edited cells then were injected into the egg of another female, reports NationalGeographic.com. In total, the team created 210 embryos, 29 of which developed into live mice. Some went on to have their own babies—confirming they were healthy. The researchers also created 12 mice with two genetic fathers; all died within 48 hours of birth. This technology isn’t ready for human use, but the study authors say it might one day be possible to create babies from same-sex parents. “We’re going to have to really think hard, as a society, about what our threshold should be for doing this kind of research,” says Sonia Suter, a bioethics expert at George Washington University.
10-26-18 Sunshine seems to protect babies from eczema – but we don’t know why
Babies who spend more time in the sun are less likely to develop eczema, but it may not be because it boosts their vitamin D levels as previously thought. Eczema is an allergic skin condition that is becoming increasingly common in children. No one knows why, but some experts think it’s because babies are spending less time outdoors and getting less vitamin D from sunlight. This is based on studies showing that people who live closer to the equator – where the sun is stronger – have higher vitamin D levels and lower rates of eczema. Debbie Palmer at the Telethon Kids Institute in Western Australia and her colleagues wondered if giving babies vitamin D supplements would stop them from developing eczema. They recruited 195 newborns whose parents or siblings had allergies and gave them vitamin D drops or a placebo every day for their first 6 months of life. They also fitted the babies with devices to measure how much ultraviolet light they received from the sun each day. To their surprise, the vitamin D supplements had no effect. But the babies who had greater sun exposure were significantly less likely to develop eczema. The findings suggest that sunlight does protect against eczema but not via the assumed vitamin D mechanism, says Palmer. It may activate other anti-inflammatory molecules in the skin like nitric oxide or urocanic acid, but further research is needed to confirm this, she says. Eczema rates may be going up because parents have become increasingly careful about keeping their children out of the sun, says Palmer. “We’ve had this very strong sun-safe message so parents are keeping their babies wrapped up and under prams with dark covers,” she says. “That’s great for preventing skin cancer but we might have gone too far.”
10-25-18 To get a deeper tan, don’t sunbathe every day
A master regulator of gene activity sets skin cells to make melanin every 48 hours. Sunbathing — if you must do it — should be limited to every other day, a new study suggests. You’ll get darker and prevent some skin damage. That’s because skin makes the protective pigment melanin only every 48 hours, researchers report October 25 in Molecular Cell. Daily sunbathing can disrupt the pigment’s production and leave skin vulnerable to damage from ultraviolet light. A protein called MITF coordinates skin-darkening melanin production with other skin protection mechanisms in response to UV light, molecular geneticist Carmit Levy of Tel Aviv University and her colleagues discovered. The team shone UV-B light on mice every 24, 48 or 72 hours for 60 days. Mice exposed to UV-B radiation on the 48-hour schedule developed darker skin and had less DNA damage than mice in the other groups. Mouse and human skin cells grown in lab dishes that were exposed to UV light every other day also made more melanin than cells that were irradiated daily. Other experiments with skin cells in dishes suggest that within minutes of UV exposure, MITF turns on genes involved in skin cell survival. Those genes make proteins engaged in inflammation, DNA repair and recruitment of immune cells to the skin. Only later does MITF give the OK for melanin production to begin. Hitting cells with daily UV interrupts melanin production, leaving skin without its protective shield, the researchers found.
10-25-18 Crashing waves may have spurred the evolution of backbones
Our backbones helped us and other vertebrate animals conquer the oceans, and move onto land and into skies. Until now, the early history of the group have been a bit of a mystery, but a new analysis suggests vertebrate animals evolved in shallow waters. All vertebrates have backbones or spinal columns. They are thought to have begun to diversify around 480 million years ago, splitting into groups that would become jawless fish (like lampreys), cartilaginous fish (including sharks), and a lineage that includes bony fish (such as salmon). It’s this last group that ultimately gave rise to amphibians, reptiles, birds and mammals. However, our understanding of this diversification event is hampered by the fact that most of our well-preserved fish fossils are only 360 million years old or younger. Now Lauren Sallan at the University of Pennsylvania, and colleagues, have brought together records of nearly 3000 early fish fossils from before this time into a single database. Comparing the features of these fossils and what kinds of environments they were preserved in reveals new clues about exactly where they diversified. “We found that all vertebrates, from the first jawless forms to sharks and bony fishes, originated in very restricted shallow waters hugging the coast line,” says Sallan. This is a bit of a surprise – big evolutionary steps are usually associated with biodiversity hotspots, such as coral reefs. But the data suggests that the evolutionary events that helped fill the seas with fishes occurred in shallow, salt-water environments like tidal areas and lagoons. Those environments may have encouraged the evolution of vertebrates because their bones helped them withstand swirling or crashing waves in shallow water environments, suggests Sallan.
10-25-18 The first vertebrates on Earth arose in shallow coastal waters
A new study answers an enduring question about where our earliest backboned ancestors lived. The cradle of vertebrate evolution was limited to a zone of shallow coastal waters, no more than 60 meters deep. In those waters, fish — the first vertebrates — appeared roughly 480 million years ago, a study finds. For nearly 100 million years, those creatures rarely strayed from that habitat, where they diversified into a dizzying array of new forms, scientists report in the Oct. 26 Science. The study resolves a long-standing mystery about where our earliest backboned ancestors arose. Scientists have long debated whether the animals appeared first in the shallows or the deep, or in fresh or salty water. “The main problem is that the fossil record [of vertebrates] is absolutely terrible for the first 50 million to 100 million years of their existence,” says paleobiologist Lauren Sallan of the University of Pennsylvania. “And when [there are] fossils, they’re in tiny pieces. It’s hard to tell what exactly’s going on.” So Sallan and her colleagues amassed 2,827 fossils of jawed and jawless fishes that lived between 480 million and 360 million years ago. To that database, the team added information on the environments that the creatures lived in — such as shallow coastal water, freshwater or the deeper ocean — based on both the geology of the rocks the fossils were found in and the invertebrate fossils also found in the rocks.
10-25-18 Splosh! How the dinosaur-killing asteroid made Chicxulub crater
It is hard to imagine billions of tonnes of rock suddenly start to splosh about like a liquid - but that is what happened when an asteroid struck the Earth 66 million years ago. Scientists have now put together a detailed picture of the minutes following the giant impact. This, remember, is the colossal event that wiped out the dinosaurs. The analysis of rocks drilled in 2016 from the leftover crater show they underwent a process of fluidisation. The pulverised material literally began to behave as if it were a substance like water. Models had predicted what should happen when a 12km-wide stony object from space punched the ground. Initially, a near-instantaneous bowl would have been created some 30km deep and up to 100km wide. Then, instabilities would have seen the sides collapse inwards and the base of the hole rebound skyward, briefly reaching higher than the Himalayas. When everything had settled down, a crater roughly 200km wide and 1km deep would remain. This is the feature that is now buried under sediments in the Gulf of Mexico, close to the port of Chicxulub. The impact description - scientists call it the dynamic collapse model of crater formation - is only possible if the hammered rocks can, for a short period, lose their strength and flow in a frictionless way. And it is the evidence for this fluidisation process that researchers now report after studying the rocks they drilled from something called the "peak ring" - essentially, a circle of hills in the centre of the remnant Chicxulub depression. "What we found in the drill core is that the rock got fragmented. It was smashed to tiny little pieces that initially are millimetre sized; and that basically causes this fluid-like behaviour that produces in the end the flat crater floor, which characterises Chicxulub and all such large impact structures, including those we also see on the Moon," explains Prof Ulrich Riller, from the University of Hamburg, Germany.
10-25-18 Huge online Trolley Problem survey reveals people’s cultural bias
A SELF-DRIVING car is travelling along a two-lane road when its brakes fail. Should it stay in lane and hit a pregnant woman, a doctor and a criminal on a pedestrian crossing, or swerve and hit a barrier, killing the family of four in the vehicle? This derivative of the classic Trolley Problem is the kind of scenario that makes up the Moral Machine experiment, an ethics survey of millions of people from 233 countries and territories around the world. Participants were asked to consider different scenarios in which those who might be saved could be, say, fit or fat, young or old, pets, criminals or those with high-status jobs. In all, 40 million decisions were collected. Overall, people preferred to spare humans over animals and younger over older people, and tried to save the most lives. The characters that people opted to save least were dogs, followed by criminals and then cats (Nature, DOI: 10.1038/s41586-018-0637-6). Edmond Awad at the Massachusetts Institute of Technology and his colleagues think these findings can inform policy-makers and the experts they may rely on as they devise regulations for driverless cars. “This is one way to deliver what the public wants,” he says. The team found that people in regional clusters made similar decisions. In an Eastern cluster, which included Islamic countries and eastern Asian nations that belong to the Confucianist cultural group, there was less of a preference to spare the young over the old, or to spare those with high status. Decisions to save humans ahead of cats and dogs were less pronounced in a Southern cluster, which included Central and South America, and countries with French influence. The preference there was to spare women and fit people.
10-25-18 Skin tans the most when spending every other day out of the sun
Skin tans most when you spend every other day out of the sun, according to a new study. This has the added effect of reducing DNA damage and premature ageing. Sunlight contains ultraviolet (UV) rays that can damage DNA and lead to premature ageing and skin cancer. To protect against this, our skin produces melanin, a dark pigment that acts like a natural sunscreen. The pigment starts to form within hours of sunlight exposure and gives the skin a tanned look. Carmit Levy at Tel Aviv University in Israel and her colleagues measured how much melanin mice produced when they were exposed to UV light every day, every second day, or every third day. They assumed that melanin production would be highest in the mice exposed to the most frequent UV periods. “Similarly, you’d think that someone who went to the beach every day would tan more than someone who went every second day,” says Levy. However, to their surprise, they found that the mice that tanned the most were those exposed to UV light every second day. The extra pigmentation they produced meant their skin also suffered the least DNA damage. The researchers then repeated the experiment using human skin samples and found the same pattern. Together, the findings suggest that skin cells need 48 hours between sun exposure periods to build up their maximum defences, says Levy. “It’s like your muscles – you need to give them time between gym sessions to let them recover,” she says. Her team is now trying to work out the evolutionary reason behind the two-day melanin cycle. “It’s strange because ancient humans would have been exposed to sun most days, so we don’t know why it takes 48 hours to work,” she says.
10-24-18 Liverwort plants contain a painkiller similar to the one in marijuana
The THC-like substance may have medical benefits minus the same kind of high. A chemical compound found in liverworts may provide the pain and inflammation relief of pot’s THC but without the same kind of high. Both the molecule, called perrotetinene, and tetrahydrocannabinol, or THC — the mind-altering substance found in marijuana — have similar molecular structures, a new study finds. And lab tests with human brain cells and in mice revealed that, like THC, perrotetinene easily attaches to the brain’s cannabinoid receptors, or molecular docking stations, dampening the effects of pain signals, researchers report October 24 in Science Advances. “Nobody really notices [liverworts] because they're so small,” says Douglas Kinghorn, a phytochemist at Ohio State University in Columbus. “Sometimes you find important medicinal compounds in plants from unexpected sources.” A group of Japanese scientists in 1994 discovered perrotetinene in liverworts, but the new study is the strongest evidence yet that the compound is a psychoactive cannabinoid. Previously, cannabis was the only plant known to produce such cannabinoids. So far, only three species of liverwort in the Radula genus — found in Japan, Costa Rica, New Zealand and Tasmania— are known to produce the compound. Because the plants make so little of the substance, researchers have struggled to study its effects, until now.
10-24-18 Why some people may be more susceptible to deadly C. difficile infections
In mice, disturbances in the mix of gut microbes set the stage for the pathogen to flourish. An intestinal pathogen that causes severe and sometimes life-threatening diarrhea is an opportunist that grows like gangbusters under the right conditions. Now, scientists may have discovered the opportunity that Clostridioides difficile waits for. In mice, a disruption of the mix of microbes in the gut sets the stage for C. difficile infections. Such upsets allow the pathogen to flourish partly by giving it more of the amino acid proline to eat, researchers report October 24 in Science Translational Medicine. The U.S. Centers for Disease Control and Prevention estimated in 2015 that more than 148 in 1,000 people develop C. difficile (previously known as Clostridium difficile) infections. Such infections usually happen after people have taken antibiotics, which can throw off the usual mix of gut microbes. Gastroenterologist Purna Kashyap of the Mayo Clinic in Rochester, Minn., and colleagues conducted experiments transplanting feces from people with normal or disturbed gut microbes into mice. Mice that got transplants from people with normal gut microbiomes were able to fight off or control C. difficile infections better than mice that got transplants from people with disturbed mixes. Altered microbe mixes led to an increase in certain amino acids in the gut, particularly proline, the researchers found. C. difficile can use proline as its main food source, giving it a competitive advantage over microbes that don’t consume the amino acid as readily. Mice fed a proline-deficient mouse chow had much less C. difficile bacteria in their intestines as mice on a normal diet, the team found.
10-24-18 Messing with fruit flies’ gut bacteria turns them into speed walkers
The result suggests that microbes in the gut may affect how the brain controls movement. Researchers have found a new link between gut and brain. By signaling to nerve cells in the brain, certain microbes in the gut slow a fruit fly’s walking pace, scientists report. Fruit flies missing those microbes — and that signal — turn into hyperactive speed walkers. With the normal suite of gut microbes, Drosophila melanogaster fruit flies on foot cover an average of about 2.4 millimeters a second. But fruit flies without any gut microbes zip along at about 3.5 millimeters a second, Catherine Schretter, a biologist at Caltech, and her colleagues report October 24 in Nature. These flies with missing microbes also take shorter breaks and are more active during the day. “Our work suggests that microbes assist in maintaining a certain level of locomotion,” Schretter says. An enzyme made by Lactobacillus brevis bacteria normally serves as the brakes, the researchers found. When researchers supplied the enzyme, called xylose isomerase, to flies lacking bacteria, the flies began walking at a slower, more normal pace. Xylose isomerase acts on a sugar that’s thought to influence nerve cells in fruit flies’ brains that control walking. For still mysterious reasons, the bacterial influence on walking speed occurred only in female fruit flies, not males. Studying that difference will be “a very interesting potential direction for this work,” Schretter says.
10-24-18 Ancient Clovis people may have taken tool cues from earlier Americans
Newly discovered Texas spearpoints could shed light on the first inhabitants of North America. Stone spearpoints from roughly 15,000 years ago suggest that descendants of some of the earliest American settlers went on to create the Clovis culture. Excavations at a site in Central Texas yielded about 100,000 stone artifacts, including 12 spearpoints, that date to between 15,500 and 13,500 years ago. The shapes of those spearpoints show a progression from stemmed points to a short triangular blade, meaning that the artifacts may have been precursors to long, triangular Clovis points, researchers report October 24 in Science Advances. By about 13,500 years ago, Clovis people had settled various sites across North America. For years, scientists thought that these people were the first inhabitants of the continent. But researchers have found a growing number of pre-Clovis human sites in the Americas (SN: 8/4/18, p. 7). In 2011, initial pre-Clovis finds were unearthed at the Buttermilk Creek Complex, part of the larger Debra L. Friedkin archaeological site and the same place where the newly discovered artifacts come from. But none of those finds could be linked to later Clovis points also from the site. In the new study, the researchers show that 11 of the 12 new spearpoints had been chipped into leaf shapes that taper into slightly narrower stems. The exception is a short, triangular spearpoint with a flat base that dates to between 14,000 and 13,500 years ago.
10-24-18 Dinosaur fossil may be a whole new species of the first birds
A new species of Archaeopteryx, the famous “first bird”, has been identified. The discovery supports the idea that Archaeopteryx really is a transitional species between dinosaurs and their bird descendants, and not an evolutionary dead end as has been suggested. Archaeopteryx was first recognised as a species in the 1860s. It was immediately seized on as evidence for Darwin’s theory of evolution, because it appeared to be a bird with dinosaur-like traits. It had wings and feathers, but teeth instead of a beak. The obvious implication was that Archaeopteryx was a transitional fossil, showing how birds evolved from dinosaur ancestors. It was about the size of a raven and may have had black feathers. It’s been suggested that it only flew in short bursts like a pheasant, and hunted at night. However, over the last decade its position in the evolutionary tree of birds has been called into question, following the discovery of similar dino-birds in China. A 2011 study built a family tree and concluded that Archaeopteryx was a dinosaur, not a bird. Martin Kundrát at the University of Pavol Jozef Šafárik in Slovakia and his colleagues have now studied a hitherto-unexamined Archaeopteryx fossil. It was found in the early 1990s, apparently in a quarry near Daiting, Germany, and ended up with a private collector. For years it remained unknown and was nicknamed “the Phantom”, until in 2009 palaeontologist Raimund Albersdörfer bought it. It is now on long-term loan to the Bavarian State Collection of Paleontology and Geology in Munich.
10-24-18 Memory special: Is your memory normal?
Why do some people remember what they did years ago, whereas others have no clue, but never forget a face or are trivia masters? Here's how to make sense of it. How much we remember of events we have experienced seems to fall on a spectrum. At one extreme, some individuals are unable to form these kinds of memories at all. “People with severely deficient autobiographical memory syndrome would report an awareness of the fact they were at the dinner, but they don’t have a feeling of re-experiencing it. It’s more of a factual memory,” says neuropsychologist Brian Levine of the Rotman Research Institute in Toronto. At the opposite end of the spectrum are those with “higher superior autobiographical memories”, who can recall in precise detail events from decades ago. The best-known case is that of a woman called Jill Price, who can recall most days of her life from the age of 11. The majority of us fall somewhere in between. Strong autobiographical memory skills are linked to the ability to form vivid visual memories of experiences, and probably to a strong sense of your own self-awareness. Known as “mind pops”, these involuntary recalls happen to all of us, on average about 20 times a day, although there is a lot of variation between individuals. “It’s a basic characteristic of autobiographical memory,” says Dorthe Berntsen of Aarhus University in Denmark, who studies this phenomenon. Once they pop into your head, they soon disappear. “They’re like dreams – if you don’t write them down, you forget all about them,” Berntsen says. We tend to experience more of these spontaneous memories as we age and retrieve fewer memories consciously, perhaps because we find it harder to inhibit thoughts as we get older. Berntsen’s work shows that they tend not to spring up when we are focused on a task, but are more likely to appear in dull moments. She thinks that, far from being an unwanted distraction, they are an important component of daily functioning.
10-24-18 Memory special: Do we even know what memory is for?
Remembering the past is useful, but the real purposes of memory may be quite different – from planning for the future to learning to communicate. AT FIRST, it seems obvious. Memory is about the past. It is your personal database of things you have experienced. In fact, this repository has a purpose that goes way beyond merely recalling information. Some of the best evidence of this came from studies of people with brain damage or amnesia. One iconic case was of a patient known as KC in the early 1980s. After a motorcycle accident, he was left with an impaired episodic memory: he could remember facts, but not personal experiences. The weird thing was, it also stopped him doing something else entirely. “By studying patients who have an impaired ability to recall the past, we find that they are also impaired at imagining the future,” says Eleanor Maguire at University College London. We now know there is a strong link between being able to remember past events and being able to plan for the future. Imaging studies, for example, show that similar patterns of brain activity underlie both. The key seems to be the ability to generate images of scenes in the mind’s eye. “If you think about it, recalling the past, imagining the future, and even spatial navigation, typically involve us constructing scene imagery,” says Maguire. It could be that being able to picture the past enabled us to imagine the future, and therefore plan – one of the complex cognitive feats that stands humans apart from many other species. If we can’t recall past events and preferences, our ability to make sound decisions crumbles too. This is because during the decision-making process, the brain uses previous choices and existing knowledge to assess options and imagine how they might turn out.
10-24-18 Memory special: What happens to memories over time?
Memories fade, but that's no accident. Forgetting is a useful trick of the mind, and even when memories are lost, they aren't always forgotten. MEMORIES fade quickly, as we all know too well. “All things being equal, it’s harder to remember things from a long time ago compared to more recent events,” says neuroscientist Marc Howard of Boston University. But forgetting doesn’t just happen by accident. Evidence suggests that it is largely down to active processes in the brain. In the hippocampus, for instance, which plays an important role in memory, new cells are formed throughout life. It takes energy to do this, yet these cells seem to overwrite established memories and induce forgetting. Why should the brain invest energy in dismantling its own memories? The issue isn’t storage space: given the number of cells and connections in the brain, there is reason to think we could remember much more than we do. According to Blake Richards at the University of Toronto, Canada, the goal of memory isn’t to store information indefinitely, but to optimise decision-making in the future (see “Do we even know what memory is for?”). And it seems that forgetting most of our experiences actually helps us learn important lessons. Each memory is thought to be stored in an interconnected network of brain cells. To retrieve a memory, you need some part of its content: for example, to recall who came to your last birthday party, you might start by picturing where the party took place.
10-24-18 Memory special: How can two people recall an event so differently?
We each have a personal memory style determined by the brain, so next time you argue with someone about what really happened, remember that you may both be right. IT IS the day after a blazing row and you are determined to clear the air. But the more you talk about the argument with your partner, the more you struggle to hide your incredulity. How can their recollection be so, well, wrong? It’s as if you are reading from different scripts. In some ways, you are. To understand how people can experience the same event but recall it so differently, we need to forget our assumptions about how memories work, says Signy Sheldon at McGill University in Canada. We tend to think of memories as information stored in the filing cabinet of the brain for future use. In fact, they are only built when we retrieve them. All the information you were bombarded with during that argument – what was said, the scene, your feelings and reactions – was just sitting there gathering dust. It wasn’t until you called the event to mind the next day that you created a mental representation of what happened. And of all the details you could have picked out, you can bet you didn’t focus on the same ones as your sparring partner. One reason for this is very basic. “We are now understanding that there are strong individual differences in how people remember,” says Sheldon. What’s more, these differences are etched in our brains. Hints at what is going on come from people who have aphantasia, the inability to form mental images in the mind’s eye. Unsurprisingly, such people’s memories also lack a visual component, even though they can recall facts. Sheldon and her colleagues wondered whether this might help in understanding the different ways other people remember things.
10-24-18 Memory special: Can you trust your memories?
Psychologist Elizabeth Loftus exposed false memories in historic sex abuse cases. Now there are new reasons not to trust your memories, she says. NO ONE has done more than Elizabeth Loftus to expose the fallibility of human memory. In the 1990s, amid growing panic over claims of satanic child sex abuse rings, the psychologist showed how easy it is for people to develop false memories of events that never happened. All it took was repeatedly being asked to imagine them. At the time, this was a common psychotherapy technique to recover supposedly repressed memories. Over the past three decades, Loftus, from the University of California, Irvine, has become well known for her work as an expert witness in legal cases. Her ongoing research on the fallibility of eyewitness testimony has taken on fresh importance in an era of fake news, the Me Too movement and digital image manipulation. I had already been looking at how reliable eyewitness testimony was, to see if people’s memories of the details of an event could be distorted. Like if the guy running away had curly hair, not straight hair. But in the 1990s, when there was an explosion of highly improbable satanic child abuse claims, it looked like people were developing whole memories for things that didn’t happen. We came up with the idea of trying to make people remember an event that never happened – being lost in a shopping mall when they were young. We told people we were doing studies of childhood memory, and we talked to their parents to get some stories. Then we would interview adults and present them with three true events from their childhood, and a completely made-up experience about how they got lost in a shopping mall, frightened, crying, and were ultimately rescued by an elderly person and reunited with the family. After they’d had about three interviews, we found that about a quarter of these adults fell prey to the suggestion and developed a partial or complete memory of being lost.
10-24-18 Memory special: Can you supercharge your memory?
Want to remember whatever you like with no effort? Superhuman enhancements in the form of memory prostheses and implants are just around the corner. SUPERHUMAN memory has a special appeal. Who could resist the idea of remembering everything they wanted to, without trying? Learning would be made easy, exams a breeze and you would never forget where you left your keys. Oh and memory-related disorders like Alzheimer’s would have met their match. So it is of little surprise that scientists have turned their attention to ways of enhancing human memory using techniques that stimulate, supplement or even mimic parts of the brain. The immediate goal is to treat memory disorders, but the idea of a memory prosthesis for everyday life is gaining ground. “We’re at the point now where on the one hand it’s very exciting, but on the other it’s controversial because we are not only treating disorders, we’re trying to enhance mental functions,” says Michal Kucewicz at the Mayo Clinic in Minnesota. One approach is deep brain stimulation (DBS), which involves zapping an affected brain area with an implanted electrode. This is already used in the treatment of Parkinson’s disease and epilepsy, among other conditions. Implanting electrodes in brain regions responsible for memory, such as the hippocampus, seems to offer a short-term memory boost too. And small studies have even suggested that DBS might reverse some of the damage seen in certain people with Alzheimer’s disease, halting the shrinking of the hippocampus and potentially encouraging it to grow bigger.
10-24-18 Memory special: What happens to your memories while you sleep?
As you slumber, the brain is a whir of activity sorting and storing your memories. How does it know which to choose, and how can you game the system? THERE is an old wives’ tale that putting your revision notes under your pillow the night before an exam will make you remember more. That might be stretching the truth, but there could be something in it – you really do learn in your sleep. You don’t need sleep to create a memory. “But sleep plays a critical role in determining what happens to these newly formed memories,” says Bob Stickgold at Harvard Medical School. Sleep determines what goes into long-term storage. It can also select which parts of a memory to retain. And it links new memories with established networks of remembrances. It discovers patterns and rules, says Stickgold, “and it’s doing this every night, all night long.” One of the biggest unanswered questions is how the sleeping brain knows which memories to strengthen, and which to ignore. “We don’t know either the algorithms the brain uses to make these decisions, or how they are implemented,” says Stickgold. What we do know is that sleep is special. “During slow-wave sleep, there is this release, a kind of beautiful set of interactions between different brain areas, that is specialised, and it looks different than what we see during awake periods,” says Anna Schapiro, also at Harvard Medical School. There is conversation between regions key to memory, including the hippocampus, where recent memories are stored, and the cortex, where long-term memories end up. This chatter might be allowing the cortex to pull out and save important information from new memories.
10-24-18 Why memories are an illusion and forgetting is good for you
Rather than a filing cabinet in the mind, it turns out memory is an exquisite illusion that shapes our sense of self. Here's how to understand yours better. WHEN considering what makes us who we are, it is easy to think our memories are the answer. Aside from the physical traces of the passing of time on your body, your recollections are perhaps the only thing that links the you sitting here today to the many yous from every previous day of your existence. Without them, your relationships would mean nothing, not to mention your knowledge, tastes, and your many adventures. It might be no exaggeration to say your memories are the essence of you. With this in mind, it is not surprising that much of the burgeoning field of neuroscience has turned its efforts to understanding what makes a memory and how to keep hold of it. Perhaps the most intriguing idea to come from recent discoveries is a reimagining of the dark side of memory – forgetting. As cherished memories fade or when we fail to remember an important task it is easy to feel that memory is failing us. But what the latest findings show is that simply thinking of memory as either accurate or fallible is a mistake. Instead, our memories are malleable, and for good reason. Rather than existing in the filing cabinet of the brain, we conjure memories from scratch with our own style (see “How can two people recall an event so differently?”). As we sleep, the brain meticulously crafts them into the most useful versions (see “What happens to your memories while you sleep?”). Technology too, affects how we remember and might even create whole new recollections (see “Is technology making your memory worse?”). As for forgetting, as infuriating as it can be, we’d be lost without it. Because memory, it turns out, is an illusion – one we create every time we recall the past and that is exquisitely designed to help you live your life.
10-24-18 Memory special: Can you choose what to forget?
If you want to forget an embarrassing encounter, you may just need to try. Forgetting isn't a passive process – so here's how to choose which memories you lose. WE ALL have memories we would rather forget – and it is possible, if you try hard enough. It is easy to think of memories as something you can actively strengthen, whereas forgetting is a passive process. But we have started to discover it can be intentional too. Perhaps the easiest way to forget something is simply to try to suppress a memory. Jeremy Manning at Dartmouth College, New Hampshire, has found that just telling people to “push thoughts out of their head” is enough to make them forget lists of words they have learned to associate with particular cues. “We don’t know how, but people seem to know how to do it.” This seems especially paradoxical because we also know that rehearsing memories helps to strengthen them. Suppression has been linked to decreased activity in the hippocampus, so we may be unknowingly reducing our hippocampal activity by focusing on the present, says Justin Hulbert at Bard College, New York. This won’t work for everyone. Post-traumatic stress disorder (PTSD) involves intrusive memories that keep coming back – often suddenly and unexpectedly. Studies have found that people with this condition are less able to suppress memories, even those unrelated to traumatic incidents. But other approaches for forgetting might help, including what are known as cognitive vaccines: interventions that can “inoculate” the brain against the onset of PTSD symptoms if administered soon after trauma.
10-24-18 Two unborn babies' spines repaired in womb in UK surgery first
Two unborn babies have had their spines repaired by surgeons - weeks before they were born. The operations - which are the first ever of their kind in the UK - were carried out by a team of 30 doctors at University College Hospital in London. The babies had spina bifida, a condition when the spinal cord fails to develop properly and has a gap in it. It is usually treated after birth, but the earlier it is repaired the better for long-term health and mobility. During the 90-minute surgery carried out this summer, doctors cut an opening in the womb and then stitched together the baby's gap in the spine. The procedure is risky and can cause premature labour, but researchers are exploring less invasive keyhole methods. "We put the mum on some drugs that help relax them, but there is still a risk," said UCL Professor Anne David, who has worked on bringing the surgery to the UK for three years. Mums and babies are recovering well, the hospital said. Mothers previously had to go abroad to the US, Belgium or Switzerland for the operation. "It's fantastic," said Prof David. "Women now don't have to travel out of the UK. They can have their family with them. There are less expenses. So all good things."
10-24-18 Tools discarded 6,000 years ago found near Muir of Ord
A harpoon or spear along with axes made by hunter-gatherers in the Highlands 6,000 years ago have been found. The tools made from red deer antlers were uncovered at a Mesolithic site at Tarradale near Muir of Ord. The harpoon may have been used in hunts of seals and wildfowl on the mudflats of what is today the Beauly Firth. Archaeologists believe the items were thrown away when a settlement in the area was abandoned, possibly as sea levels rose. The archaeological finds were made by Tarradale Through Time: Community Engagement with Archaeology in the Highlands. It is a major multi-period archaeology project based at Tarradale and funded by the Heritage Lottery Fund and Historic Environment Scotland. The three-year project started in 2017, the same year the tools were found during excavations of a raised beach, an area of land about 9m (29ft) above the present coastline of the firth. Those involved in the project have described the Mesolithic finds as "highly significant". They said the antler axes - called T-axes because of their distinctive shape - were "very rare finds" and only a handful been found in Scotland previously. Last year's excavation also uncovered a large shell midden, a place where the hunter-gatherers threw the uneaten remains of shellfish. Mesolithic finds have been made elsewhere in the Highlands in recent years. They have included the remains of hazelnuts eaten by some of Skye's earliest inhabitants. Hazelnuts were a favourite snack of Mesolithic hunter-gatherers, according to archaeologists at the University of the Highlands and Islands (UHI). The shells found in 2015 at an excavation above Staffin Bay were believed to be 8,000-years-old.
10-24-18 Bird-like lungs may have helped dinosaurs rule the world
When dinosaurs dominated Earth, they somehow coped with low oxygen levels. Now a new finding suggests they may have thrived thanks to bird-like lungs. Many dinosaurs were swift and active animals, which is puzzling given that Earth’s atmosphere contained less oxygen than it does today when dinosaurs ruled. They may have thrived in the challenging conditions due to their efficient bird-like lungs, according to a new study. “Birds and mammals are highly active and evolved a way of living that requires a lot of oxygen, so their lungs are complicated,” says Robert Brocklehurst at the University of Manchester, UK. “Lizards and snakes have simpler lungs – they don’t need to get a lot of oxygen out of the air because they’re not doing anything with it.” He and his colleagues compared dinosaur lungs both to those of living crocodilians – which shared a common ancestor with dinosaurs – and to those of birds, which are modern-day descendants of dinosaurs. They removed the lungs of an alligator and an ostrich, and found that the skeletal support structures surrounding the lungs were dramatically different. The alligator’s lung cavity is smooth, which Brocklehurst says may allow the lungs and some other internal organs to glide as they move to pump air in and out while the animal swims. The ostrich lung cavity, in contrast, is furrowed. Rows of vertebrae and ribs jut into it, leaving deep grooves in the surface of the lungs. “The ribs are very much embedded in the lung tissue and that gives it a lot of structural support,” says Brocklehurst. With that much physical support, the walls of the lungs don’t have to be as thick, he says, which means the soft tissue of the blood-gas barrier can be thinner. As a result, birds can extract more oxygen from the air they breathe and transfer it into their blood.
10-24-18 Weird rocks in Australia are a missing piece of the Grand Canyon
Some rocks in Tasmania, Australia, look out of place. Now an analysis suggests they were once part of the rocks that form the Grand Canyon in the US. THE Grand Canyon in Arizona has a bizarre Antipodean link. A chunk of the rock sequence that has been sliced through to form this natural wonder of the world now sits thousands of kilometres away in Tasmania, Australia. To peer into the Grand Canyon is to behold, in its rock layers, a record of Earth’s distant past. The oldest layers at the bottom date back more than 1.5 billion years. It is some of the most ancient layers in the sequence that interest Jack Mulder, a geologist at Australia’s Monash University. He thinks these rocks – which are between about 1.1 and 1.2 billion years old – look just like similarly ancient rocks in Tasmania. The Tasmanian rocks in question have always seemed a bit out of place, he says. “They didn’t look a lot like similarly aged rocks nearby.” Mulder and his colleagues have now found that the rocks contain minerals with the same “geochemical fingerprint” as those in the Grand Canyon (Geology, doi.org/cv24). “We concluded that although it’s now on the opposite side of the planet, Tasmania must have been attached to the western United States,” he says. Beyond extending the Grand Canyon’s reach across the Pacific and into the southern hemisphere, uniting the Tasmanian rocks with those in North America helps to solve an ancient geological jigsaw puzzle. About a billion years ago, all of Earth’s continental plates formed a single supercontinent called Rodinia. But working out exactly how today’s continents would once have fitted together to form Rodinia is no simple task given how long ago it existed. The Tasmanian discovery provides a clue because it is clear evidence that North America and Australia were linked together at the time.
10-23-18 Six children dead in virus outbreak at US health centre
A viral outbreak at a New Jersey long-term medical care centre has killed six children and left a dozen more infected. State officials confirmed a total of 18 cases of adenovirus among paediatric patients at the Wanaque Center for Nursing and Rehabilitation on Tuesday. Adenoviruses typically cause "mild illness" but the children affected are "medically fragile", officials say. The state investigation is ongoing. The centre is now closed to new patients. The children involved have "severely compromised immune systems" rendering them more susceptible to the virus, the health department said. "The combination of a worse strain of adenovirus together with a fragile population has led to a more severe outbreak," it added. The health facility in Haskell is privately owned. The centre did not immediately respond to a request for comment from the BBC. According to a Department of Health release, state officials began investigating on Sunday and continued on Tuesday. On Sunday, an inspection team found "minor handwashing deficiencies" at the centre, which also provides short- and long-term adult nursing and rehabilitation services. It is still unclear how and when exactly the outbreak began. Local news site NewJersey.com reported that a letter had been sent to parents of patients about an outbreak on 18 Oct, but officials did not confirm any details about the virus until Tuesday. The state health department is "continuing to work closely with the facility on infection control issues". Children in the centre's paediatric ward are seriously ill - many are disabled, in comas, or cannot walk or speak, the North Jersey Record reported.
10-23-18 New clues to unravelling link between pregnancy and breast cancer risk
Women are less likely to get breast cancer if they give birth before the age of 30. Now we know the effect kicks in specifically after 33 weeks of pregnancy. We’ve known for some time that a woman’s risk of breast cancer is reduced by both the number of children she has and at what age she gives birth to them – although exactly why is a mystery. A new study of the populations of Denmark and Norway offers clues. It suggests that the duration of pregnancy may be key, with a woman’s relative risk of breast cancer dropping sharply between 33 and 34 weeks of pregnancy. Mads Melbye at the Statens Serum Institute in Denmark and his colleagues used national registries on childbirth and cancer that included 2.3 million Danish women and 1.6 million Norwegian women. They looked at long-term effects, tracking the cases of breast cancer 10 years or more after pregnancy. The researchers found that women who had pregnancies lasting 33 weeks or less saw a reduction in their breast cancer risk of 2.4 per cent on average. However, if their pregnancy lasted 34 weeks or more, their relative risk was reduced by 13.6 per cent on average. If a woman’s second pregnancy reached this 34-week point her risk was reduced by 16.9 per cent, and if it was her third pregnancy, her relative risk of breast cancer after a pregnancy that reached 34 weeks was reduced by 37.7 per cent. Melbye and his team found that the link between reduced cancer risk and a pregnancy that reaches 34 weeks occurred whether or not the pregnancy resulted in a live or a stillbirth. Though breastfeeding has been shown to reduce cancer risk following pregnancy, this new finding suggests it is not the only thing at work.
10-23-18 Bone hormone released during exercise may lead to new memory-loss drug
Age-related memory loss might be reversed by boosting the effects of a hormone released by bones during exercise. Busy feet, better memory. A hormone released by bone during exercise improves memory storage and retrieval in aged mice – and a new study into the way it operates has identified a protein that could form the basis of a treatment for age-related memory loss. As we get older, the gearwheels that keep our body functioning – such as hormone secretion and cell regeneration – turn at a slower rate. For instance, a bone-building hormone called osteocalcin is produced at a reduced level as we age. In their previous research, Eric Kandel and his colleagues at Columbia University in New York found osteocalcin also plays an important role in cognition — mice with osteocalcin deficiency showed symptoms of memory loss. They have also tied this memory loss to the activity of a gene called RbAp48, the activity of which increases in mice injected with osteocalcin. Now Kandel’s team has explored further. They injected 16-month-old mice — an equivalent of 70 in human years — with osteocalcin. Within 48 hours, the team found the mice had a 15 per cent increase in the expression of RbAp48 in their brains. What’s more, old mice given the injection appeared to have fewer problems with memory than old mice that had not received the hormone jab.
10-23-18 Teens use Juul e-cigarettes much more often than other vaping products
Such devices are more popular with youth than other e-cigs or cigarettes, a study finds. Teens who try the latest, sleekest iteration of electronic cigarettes may be more likely to become regular users, compared with those who try other e-cigarettes or regular cigarettes, a new study suggests. These pod-mod e-cigarettes, which resemble a USB drive, come with a prefilled pod of flavored liquid that contains a higher concentration of nicotine than other e-cigarettes. And the devices are small and don’t produce much vapor, making them easy to conceal. Researchers asked 437 California high school students about their use of a particular pod-mod e-cigarette called Juul as well as other e-cigarettes or traditional cigarettes. About 16 percent, or 68 respondents, said they had tried “Juuling,” a term teens use for vaping with this product. Close to 60 percent of that group said they’d used the product in the last 30 days, according to a study published online October 19 in JAMA Network Open. That’s in contrast to the use reported by 133 teens who had tried other e-cigarettes or the 106 who had tried cigarettes: 30 percent reported vaping in the last 30 days and 28 percent said they had smoked in the last month. If supported by other work, the study’s findings “may mean that pod-based electronic cigarettes offer an even greater risk of nicotine dependence than other nicotine [and] tobacco products in this vulnerable population,” says psychologist Thomas Eissenberg of Virginia Commonwealth University in Richmond, who coauthored a commentary accompanying the study. Nicotine exposure leads to addiction and harms teens’ developing brains (SN for Students: 8/19/15).
10-23-18 Tiny supercomputers could be made from the skeleton inside your cells
Building a computer out of the skeletons that hold our cells together could make them smaller and far more energy efficient. Building computers out of the skeleton that holds our cells together instead of silicon could make them smaller and more energy efficient than the power-hungry machines we rely on today. To encourage the development of such computers, Andrew Adamatsky at the University of the West of England in Bristol, UK, and his colleagues have produced a theoretical foundation for computing with cytoskeletons — the protein-based scaffolds that give cells their shape and help them move. Cytoskeletons are made up of several different structures, including 25 nanometre-wide tubules made from a protein called tubulin and 6 nanometre-wide filaments made from a protein called actin. These structures regularly distribute information in the form of patterns of atoms, electrons and ions. By forcing these patterns to combine in various ways, it is possible to perform very basic computations – essentially producing the basic units of digital computers called logic gates. Adamatsky has pulled all of this together into an overall theory for the first time. “I fused the ideas in an attempt to develop a coherent theory of computing,” he says. He and his colleagues argue that cytoskeleton devices would have an advantage over ones made from DNA, another form of biological calculator that some researchers think could supercharge computing. DNA is good at storage but less good at processing signals, he says. Tubulin and actin are also less complex than DNA, which makes them easier materials to work with.
10-23-18 Shipwreck found in Black Sea is 'world's oldest intact'
A Greek merchant ship dating back more than 2,400 years has been found lying on its side off the Bulgarian coast. The 23m (75ft) wreck, found in the Black Sea by an Anglo-Bulgarian team, is being hailed as officially the world's oldest known intact shipwreck. The researchers were stunned to find the merchant vessel closely resembled in design a ship that decorated ancient Greek wine vases. The rudder, rowing benches and even the contents of its hold remain intact. "It's like another world," Helen Farr from the expedition told the BBC. "It's when the ROV [remote operated vehicle] drops down through the water column and you see this ship appear in the light at the bottom so perfectly preserved it feels like you step back in time." The reason the trading vessel, dating back to around 400 BC, has remained in such good condition for so long is that the water is anoxic, or free of oxygen. Lying more than 2,000m below the surface, it is also beyond the reach of modern divers. "It's preserved, it's safe," she added. "It's not deteriorating and it's unlikely to attract hunters." The vessel was one of many tracking between the Mediterranean and Greek colonies on the Black Sea coast. It was discovered more than 80km off the Bulgarian city of Burgas. The team used two underwater robotic explorers to map out a 3-D image of the ship and they took a sample to carbon-date its age. The vessel is similar in style to that depicted by the so-called Siren Painter on the Siren Vase in the British Museum. Dating back to around 480 BC, the vase shows Odysseus strapped to the mast as his ship sails past three mythical sea nymphs whose tune was thought to drive sailors to their deaths.
10-22-18 Hot baths could improve depression as much as physical exercise
Taking a hot bath twice a week may help relieve mild depression. It may work by resetting circadian rhythms, which are often disrupted in people with depression. Long soaks in a hot bath could help with depression. A small study has found that afternoon baths just twice a week produce a moderate but persistent lift to mood. The size of the benefit was similar to that seen with physical exercise, which is a recommended therapy for mild or moderate depression. The method could work because raising body temperature in the afternoon helps restore the normal circadian rhythm of temperature, which is often disturbed in people with depression. The baths also improved people’s sleep patterns. Depression is one of the most common mental-health issues and is usually treated with antidepressants and talking therapy. However, the medication may cause side effects, and a course of talking therapy can be expensive, sometimes with long waiting lists in the UK National Health Service, for instance. The root cause of depression is unclear. The dominant view is that there is not enough of a brain-signalling molecule called serotonin, because antidepressants seem to boost levels of this compound. Another suspect is disturbed circadian rhythm, the physical and biochemical changes that happen to our bodies over the day. Your body temperature would normally rise in the morning, peak in the afternoon, then dip back down when you sleep, following a wave-like curve with a difference of about a 1°C between day and night. But if you have depression, the cycle may be flatter, erratic or delayed by a few hours causing the peak to occur later in the day.m and improve mood.
10-22-18 Plants engineered to always be on alert don’t grow well
Scientists bred a weed to lack proteins that help stem production of insect-repelling chemicals. A tiny weed that slithers up through sidewalk cracks is helping scientists understand the sacrifices that plants make to protect themselves from pests. Most plants combat insects and other herbivores by sending out bitter chemicals through their leaves. Now by studying thale cress (Arabidopsis thaliana), a commonly found member of the mustard family, researchers found that energy spent pumping protective chemicals through a plant’s veins diminishes its ability to grow and successfully reproduce. “When plants use those resources for defense — in this case, defense against insects — there is a major trade-off,” says Gregg Howe, a plant biologist at Michigan State University in East Lansing. He and his colleagues report their findings online October 22 in the Proceedings of the National Academy of Sciences. All plants have a bundle of what are known as JAZ genes. Those genes provide the instructions to make JAZ proteins, which help plants control the use of the defensive chemicals. Over a decade, the team disrupted the activity of 10 of the 13 JAZ genes found in Arabidopsis plants to hinder production of those proteins. As a result, the engineered plants were nearly permanently in defensive mode, which ultimately made them shorter, weaker and with fewer viable seeds than their normal counterparts, the scientists found. Brown and withered leaves also revealed that the engineered plants were starved of carbon, meaning they weren’t getting enough food. Maintaining such a defensive strategy consumes energy that the plant could otherwise use for growth or reproduction, the researchers speculate.
10-22-18 An eye disorder may have given Leonardo da Vinci an artistic edge
A neuroscientist offers evidence that the artist had exotropia, in which one eye turns outward. If Leonardo da Vinci had a good eye doctor, he might not have become such a great artist. At least that’s what an analysis of paintings and sculptures believed to be modeled after da Vinci suggests. Visual neuroscientist Christopher Tyler of the City University of London examined six pieces of art, including Salvator Mundi and Vitruvian Man. Five of the pieces depict an eye misalignment consistent with a disorder called exotropia that can interfere with three-dimensional vision, Tyler reports online October 18 in JAMA Ophthalmology. Exotropia, in which one eye turns slightly outward, is one of several eye disorders collectively called strabismus. Today, strabismus, which affects 4 percent of people in the United States, is treated with special glasses, eye patches or surgery. Tyler calculated the differences in eye alignment using the same sorts of measurements that an optometrist does when tailoring a pair of glasses. Most of the portraits showed the eyes misaligned, but Vitruvian Man by da Vinci himself did not. As a result, da Vinci may have had intermittent exotropia, present only some of the time and perhaps controllable, Tyler suspects. “The person [with intermittent exotropia] can align their eyes and see in 3-D, but if they’re inattentive or tired, the eye may droop,” he says.
10-22-18 T. rex pulverized bones with an incredible amount of force
A strong bite and powerful teeth let the dinosaur get at nutritious marrow and salts. Tyrannosaurus rex had a special way of crunching bones. A lethal combination of a powerful bite, strong teeth and repeated crunching allowed these giant predators to pulverize the bones of their prey, researchers reported October 20 at the Society for Vertebrate Paleontology’s annual meeting. Bones have a nutritious inner cavity containing marrow and phosphate salts. But to access those goodies, most bone crushers have to be able to clamp their jaws together to crunch through the dense outer protective layer of bone. Some carnivorous mammals, like spotted hyenas and gray wolves, can do this. But bone-crushing is unknown among living reptiles because their upper and lower teeth don’t fit together, or occlude, in a way that allows them to clamp. Instead, most modern reptilian predators just swallow the bones whole to get at the nutrients. Tyrannosaurs, including T. rex, didn’t have mammallike occluding teeth either, but fossil evidence suggests that the dinosaurs somehow pulverized the bones of their prey. To figure out how, anatomist Paul Gignac of Oklahoma State University in Tulsa and vertebrate paleontologist Gregory Erickson of Florida State University in Tallahassee examined fossil evidence of the creatures’ dining behavior. The duo also investigated the bite forces of the only living dinosaurs, birds, as well as crocodiles, dinosaurs’ closest living relatives. Extrapolating from that evidence, the researchers estimated T. rex’s bite force and the amount of pressure the dinos’ teeth could exert at their tips.
10-21-18 How to make organ transplants last
New approaches try to train the body to welcome the replacement parts. Trent Jackson’s life changed abruptly in early 2015. The computer engineer thought he had the flu. His then-wife, Donna Sylvia, thought differently. His skin was turning a dark golden yellow, almost brown, “like he was getting some kind of weird tan,” she says. On Wednesday, January 28, Sylvia and Jackson’s brother Todd finally persuaded Jackson to see a doctor. Sylvia’s suspicions were confirmed: Jackson’s liver had failed. His kidneys shut down, too. Doctors rushed him by air ambulance from Columbia, Md., to Johns Hopkins Hospital in Baltimore. There, he scored 39 on a 40-point scale that gauges how likely a person in liver failure is to die without a liver transplant in the next three months. People in his condition are often considered too sick for surgery, Jackson says. But on February 15, he got a new liver. “I guess they decided that other than being mostly dead, I was pretty healthy.” Jackson, 53, got a second chance, but his ordeal hasn’t ended. He takes three drugs every day to keep his immune system from attacking the donor organ. (Transplant recipients often take daunting drug regimens, but many are able to gradually reduce the amount of medication.) Over the long haul, the drugs leave people vulnerable to infections, kidney damage, cancer and type 2 diabetes. Jackson hasn’t experienced the most dire side effects. But tacrolimus, an immunosuppressive drug, makes his hands shake, and a steroid he takes caused cataracts, for which he needed surgery last year.
10-20-18 DNA differences are linked to having same-sex sexual partners
The specific genes involved in mate choice aren’t yet known. For some people, choosing a same-sex partner may be in their DNA. In a large study of more than 490,000 men and women in the United States, United Kingdom and Sweden, researchers discovered four genetic variants that occur more often in people who indicated on questionnaires that they had had same-sex sexual partners. Andrea Ganna, a geneticist at the Broad Institute of MIT and Harvard reported the results October 19 at the annual meeting of the American Society of Human Genetics. Two of the variants were specific to men’s sexual partner choice. The other two influence sex partner choice for both men and women. Collectively, the DNA differences explained only 8 to 12 percent of the heritability of having same-sex partners. “There is no gay gene,” Ganna said, “but rather non-heterosexuality is influenced by many tiny-effect genetic factors.” The new study is an advance over previous attempts to find “gay genes,” says J. Michael Bailey, a psychologist at Northwestern University in Evanston, Ill., who was not involved in the new work. The study’s size is its main advantage, Bailey says. “It’s huge. Huge.”
10-20-18 Why green space is good for kids' brains
New research suggests that time spent in nature can help children's memory retention. Several recent studies have found children tend to fare better academically if they have ample access to the natural world. But the reasons for this remains hazy. Do they get more exercise? Breathe cleaner air? Recent British research reveals one likely advantage such kids enjoy. It finds they score higher on a standard test of Spatial Working Memory — the ability to retain visual information long enough to process it and make use of it to solve problems. For a child, this may mean developing an innate sense of whether they have taken the proper path through a wooded area. But the benefits are far broader: Spatial Working Memory has been linked to mathematical ability too. The research team, led by psychologist Eirini Flouri of University College London, used data on 4,758 11-year-olds living in urban areas in England. The amount of green space in their neighborhoods was estimated using data derived from satellite images. The kids all completed a standard test in which they were asked to search for blue tokens on a computer screen by clicking on boxes of various colors. The task gets more difficult as more boxes are added. Participants are instructed not to return to a box where a token has already been found, which forces them to remember which boxes have already been searched. After taking into account various factors that could influence their ability, the researchers found "children living in greener neighborhoods have better working memory." This remained true even after adjusting for parental education and participation in sports. "This is a substantively important finding," they write in the British Journal of Educational Psychology. "Exposure to green space may have specific cognitive benefits for children."
10-19-18 New therapies pack a triple-drug punch to treat cystic fibrosis
The approach, still in clinical trials, might one day provide relief to many with the disease. For years, scientists have struggled to find a therapy that works for most cystic fibrosis sufferers. Now, two new triple-drug approaches, still undergoing testing, are offering hope. Cystic fibrosis is caused by mutations in a gene called CFTR. These mutations mean the body either makes defective versions of a protein, also called CFTR, or none of the protein at all. The new therapies work to partly fix underlying problems with one type of defective protein. Two triple-drug approaches, taken for four weeks, each significantly improved the lung function of people with the most common cystic fibrosis–causing mutation. About 90 percent of people with the disease have this mutation. Plus, the drugs were safe, with tolerable side effects, researchers report online October 18 in two studies in the New England Journal of Medicine. With continued testing and approval, a triple-drug combination could potentially provide an effective treatment for the first time for the vast majority of cystic fibrosis patients. The triple-drug approach produced “a really robust improvement in pulmonary function,” says Hartmut Grasemann, a pediatrician at the Hospital for Sick Children in Toronto who was not part of the research. And it “works for almost all patients with cystic fibrosis, which is quite amazing.”
10-19-18 The dangers of a Southern diet
A new study has identified a possible reason why African-Americans are more likely to suffer from high blood pressure than white Americans: the Southern diet. Researchers at the University of Alabama examined health data from nearly 7,000 men and women, ages 45 and over, from across the U.S. Over the 9-year study, 46 percent of black participants developed hypertension, compared with 33 percent of white participants, a disparity roughly in line with previous research. Scientists found that those who ate a Southern-style diet—one heavy in fried foods, dairy, soda, bread, and processed and organ meats—were about 13 percent more likely to have the condition than those who ate another diet. Black participants were much more likely to eat a Southern diet. George Howard, who led the study, notes that African-Americans’ life expectancy is about four years shorter than white Americans’. Hypertension—which can cause heart attacks, stroke, and kidney failure—is a big contributor to that disparity. Figuring out why so many African-Americans have this condition, Howard tells NPR.org, “is sort of the holy grail of research.”
10-19-18 Neanderthals’ genetic gift
Ancient hookups between our ancestors and Neanderthals may have given modern humans the ability to fight off potentially deadly infections. Homo sapiens and Homo neanderthalensis (right) interbred during two periods, some 100,000 and 50,000 years ago, and today most Europeans and Asians have about 2 percent Neanderthal DNA. Researchers examined 152 of the genes we inherited from Neanderthals and found that they interact with flu and hepatitis viruses—indicating that they may help fight those infections. When humans began migrating out of Africa and into Eurasia, they encountered Neanderthals, who had been living in the region for hundreds of thousands of years. Neanderthals’ immune systems had adapted to Eurasian diseases—protections they likely passed on to humans through interbreeding. “One of the things that population geneticists have wondered about is why we have maintained these stretches of Neanderthal DNA in our own genomes,” study leader David Enard of the University of Arizona, tells ScienceDaily.com. “This study suggests that one of the roles of those genes was to provide us with some protection against pathogens as we moved into new environments.”
10-19-18 In a first, scientists spot what may be lungs in an ancient bird fossil
But some paleontologists aren’t convinced the preserved structures are respiratory organs. Fossilized lungs found preserved along with an ancient bird may breathe new life into studies of early avian respiration. If confirmed as lungs, the find marks the first time that researchers have spotted the respiratory organs in a bird fossil. Scientists have previously described four fossils of Archaeorhynchus spathula, an early beaked and feathered bird that lived about 120 million years ago. But unlike those discoveries, a newly described fifth specimen contains significant traces of plumage, and, even more startling, the probable remnants of a pair of lungs, researchers say. Vertebrate paleontologist Jingmai O’Connor and colleagues reported the findings October 18 at the Society for Vertebrate Paleontology’s annual meeting. The results were also published online October 18 in the Proceedings of the National Academy of Sciences. About the size of a thrush, Archaeorhynchus was among the earliest ornithuromorphs, the lineage that led to modern birds. It was probably an herbivore, as all known fossils of the creature contain preserved gastroliths, or gizzard stones which some animals use to help grind food, in the belly. The new fossil was found in northeastern China and is part of the Jehol Biota. That wealth of well-preserved fossils dates to between 133 million and 120 million years ago and includes numerous feathered dinosaurs as well as birds.
10-19-18 50 years ago, the safety of artificial sweeteners was fiercely debated
Excerpt from the October 26, 1968, issue of Science News Americans consume 8,000 tons of artificial sweeteners every year …confident that the chemical sweeteners are safe. Manufacturers insist that they are; the sugar industry … insists they are not.… [B]oth camps swamped FDA with detailed evidence pro and con. — Science News, October 26, 1968. Update: Let’s not sugarcoat it: The debate isn’t over. Fifty years ago, the Food and Drug Administration said there was no evidence of health hazards from cyclamates, one type of sweetener. Since then, various sweeteners have become ubiquitous in sodas, reduced-calorie yogurts and more. A 2014 study in mice and humans revealed that saccharin may alter the gut microbiome, mucking with the body’s ability to use glucose (SN: 10/18/14, p. 6). Another study suggested that artificial sweeteners in diet sodas might encourage overeating by interfering with how the brain keeps tabs on calories (SN: 7/14/12, p. 14). These studies hint that artificial sweeteners may actually promote diabetes and obesity — the exact opposite of what’s intended.
10-19-18 A14 road workers find woolly mammoth bones
Road workers building a new bypass have unearthed the Ice Age remains of a woolly mammoth and a woolly rhino. The team, working on improvements to the A14 between Cambridge and Huntingdon, discovered a number of bones while digging near Fenstanton. Experts believe the remains, found in what was once an ancient river, could be at least 130,000 years old. Palaeontologist Dean Lomax said discoveries like this were "exciting" and "quite uncommon". Highways England confirmed the prehistoric bones will be sent to specialists in London for further analysis. A spokesman they were "the latest in a series of fantastic finds" from the team working on the A14. So far, they have also unearthed prehistoric henges, Iron Age settlements, Roman kilns, three Anglo-Saxon villages and a medieval hamlet. Mr Lomax, who is a visiting scientist at The University of Manchester, said it was "exciting" the bones were discovered during roadworks. "What I would really like to know is how much of each animal has been found," he said. "Woolly mammoth and woolly rhino were once a common part of the wildlife here in the UK but recent discoveries like this are quite uncommon. "It would be interesting to know whether this is a one-off discovery or whether more individuals are preserved in the same area." (Webmaster's comment: The evidence of evolution is everywhere except in the mind of the religious ignorant.)
10-19-18 Jurassic-era piranha is world's earliest flesh-eating fish
Scientists have unearthed the fossilised remains of a piranha-like species that they say is the earliest known example of a flesh-eating fish. This bony creature, found in South Germany, lived about 150 million years ago and had the distinctive sharp teeth of modern-day piranhas. These Jurassic marauders used their razor teeth to tear chunks of flesh and fins off other fish. Other fish were found nearby which had been attacked by the ancient piranhas. "We have other fish from the same locality with chunks missing from their fins," said Dr David Bellwood of James Cook University, Australia, who is one of the authors of the study. "Feed on a fish and it is dead; nibble its fins and you have food for the future." The researchers analysed the jaws and found long pointed teeth on the exterior of a bone forming the roof of the mouth. They also found triangular teeth with serrated edges on bones that lie along the side of the lower-jaw. The international team of scientists concluded that the pattern and shape of the teeth, jaw morphology and mechanics suggested a mouth well-equipped to slice flesh or fins. "We were stunned that this fish had piranha-like teeth," says Martina Kölbl-Ebert, of Jura-Museum Eichstätt, who led the study. "It comes from a group of fishes (the pycnodontids) that are famous for their crushing teeth. It is like finding a sheep with a snarl like a wolf. But what was even more remarkable is that it was from the Jurassic. "Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time. Sharks have been able to bite out chunks of flesh but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later."
10-18-18 Your brain is like 100 billion mini-computers all working together
Recording the electrical activity of the fine branches of human neurons has revealed that our brain cells are much more sophisticated than those of other animals. Each of our brain cells could work like a mini-computer, according to the first recording of electrical activity in human cells at a super-fine level of detail. The study has revealed a key structural difference between human and mouse neurons that could help explain our superior powers of intelligence. Brain cells, or neurons, communicate by firing electrical impulses down their length, which researchers can detect and measure by putting microscopic electrodes inside them. Most such studies have been done on rodent neurons kept alive in a dish, where the cells can live for several hours. But Mark Harnett at the Massachusetts Institute of Technology in Cambridge wanted to see how human neurons compared with those of mice, so he used live tissue obtained from surgeons who were removing small chunks of brain from people with epilepsy. While people have recorded signals from inside human neurons before, it has always been inside the main “trunk” of their tree-like structure. Harnett’s team used thinner electrodes to record activity inside the fine branches, known as dendrites, at the end of the trunk. Each neuron may have about 50 dendrites, and each dendrite has hundreds of synapses, or connection points with other neurons. It’s signals running across these synapses and into the dendrite that make it more or less likely that the dendrite itself will fire an electrical signal along its length. Compared with mice, the dendrites of human neurons turn out to have fewer ion channels, molecules studded in the cell’s outer membrane that let electricity flow along the dendrite.
10-18-18 Your genes affect which university you go to but that’s no surprise
A study has found links between a person's genes and university. But intelligence and other complex traits are shaped by both genetics and environment.
- I’ve heard there is a gene that gets you into Oxford – can it really be true? Hardly. A large study of 3000 pairs of UK twins has found that, like intelligence, your chance of getting into a good university is partly heritable.
- What does “university quality” mean? The team used existing university league tables as a measure of quality, although sceptics might argue this doesn’t take account of the possibility that different institutions could suit different people for reasons other than their academic prestige – or even that plenty of intelligent people choose not to go to university at all.
- So could a genetic test tell you which university your child could get in to? Fortunately not. The same team also looked at the DNA of a different 3000 people and could only identify up to 5 per cent of the genes that seemed to be linked to universities.
- Do we know how much of a person’s intelligence is determined by their genes? Previous research has suggested between 50 and 80 per cent of the variation in people’s IQ is inherited. As intelligence affects school exam results and they in turn influence which university you go to, it’s unsurprising that genes may be linked to university destination too.
- So is it case closed? Not necessarily. Intelligence genes might influence your university through other mechanisms than exam results, for instance by affecting how impressive an application form you write and how well you do at interview.
- Isn’t the whole concept of IQ falling into disrepute anyway? Not really. Certainly there is a shameful history of people using IQ tests to justify racist and sexist attitudes without taking societal inequalities into account. But that doesn’t mean the tests themselves are flawed.
- So our fate is determined at birth after all? Not at all. If half the variation in intelligence – or university destination – comes down to our genes, the rest must be down to our surroundings.
- So intelligence, like all complex behavioural traits, comes from an interplay of genetic and social factors? Go to the top of the class.
10-18-18 Pregnancy changes how hundreds of genes work in a woman’s body
Genes that alter their expression during healthy pregnancies have been identified for the first time, potentially helping us to predict at-risk pregnancies. It’s no secret that women’s bodies go through radical changes during pregnancy, but we’re finally starting to understand what happens at the gene level. Alicia Smith at Emory University in the US and her colleagues took blood samples from 63 women early and late in pregnancy to see if they could detect any changes in their gene expression. Of the 16,000 genes they looked at, they found that 439 altered their activity between the first and third trimester of pregnancy. Many of these changes occurred in genes involved in the immune and circulatory systems, both of which are known to undergo major transformations during pregnancy. For instance, the researchers observed increased expression of several genes from the alpha-defensin family, which help to fight disease-causing bacteria, fungi and viruses. This is probably to protect the fetus from microbes like listeria that can cause spontaneous abortion and pre-term birth, says Smith. Changes were also seen in genes that protect the fetus from the mother’s own immune system. “Your immune system is designed to identify foreign cells and fight them, which makes carrying a fetus very complicated,” says Smith. “That’s why pregnancy is associated with a number of immune changes that stop your body from rejecting the foreign fetus.”
10-17-18 Fasting power: Can going without food really make you healthier?
Fasting diets are getting ever more popular, amid promises of weight loss and better health, but does the science stand up? We put the latest one to the test AS I unpack my rations for the next five days, I start to question what I have signed up to. For years I have heard the hype about fasting diets and what they promise: smaller thighs, a clearer head, a lower risk of cancer, heart disease and diabetes and the promise of a generally longer, healthier life. But then there is the hunger. Hunger makes me angry, and tired, and generally not a very nice person. So I have always given fasting diets a miss: the 5:2 diet where you fast for two days a week and eat normally the others; the 16:8 where you eat within an 8 hour window, and fast for 16; the alternate day fasting. You name it, it seems someone has tried it. Then I heard about one of the latest trends, the fasting mimicking diet. If the marketing materials are to be believed, it is the holy grail: all the health benefits of fasting without the hunger. The company behind it has even become the first to be granted a patent for boosting human healthspan before the onset of disease. So can I really have my cake and eat it? I decided to give it a go – and try to get to the truth about fasting. We have known for decades that restricting calories can have beneficial effects – if not in humans, then in animals. Many studies have found that organisms from single-celled yeasts to rodents age more slowly and live longer when their calorie intake falls to 40 per cent of that consumed by a group of animals eating normally. Constant calorie restriction has never really caught on in people, however, not least because the results didn’t bear out in primates. Besides, people find it difficult to restrict their diet in this way for long enough to find out if it extends their lives.
10-17-18 Why plans to achieve zero suicides might actually be counterproductive
Health bodies and politicians are aiming for zero suicides, but doctors are warning this ambitious goal is simply unrealistic. “ZERO suicide” is the phrase of the moment in mental health. Thanks to a programme in Detroit that managed to push rates of suicide to zero within a few years, the approach has spread to health bodies all over the world. Last week, the UK government appointed England’s first minister for suicide prevention, on the back of a “zero suicide ambition” for patients in the care of the National Health Service announced in January. Reducing the number of suicides is clearly a desirable goal. Yet some doctors view the zero suicide movement with alarm, fearing that such a challenging goal may actually be counterproductive. Some of the earliest successes in suicide prevention simply involved changes that made it more difficult for people to take their own lives. Proponents point to the unintended benefit seen in the UK in the 1960s when the gas supply to people’s homes gradually became less poisonous. At the time, deliberate gas inhalation accounted for about half of UK suicides. By the end of the 1960s, the total suicide rate had dropped by a third. More recently, deaths seem to have been avoided by a change in UK law to restrict pack sizes of the painkiller paracetamol, also known as acetaminophen. From 1998, the tablets could only be sold in small quantities. Ten years later, deaths from paracetamol poisonings had halved. Effects like these show that suicidal thoughts can sometimes be transient, says Keith Hawton at the University of Oxford. “If you can keep people safe until those thoughts diminish, you can save lives.”
10-17-18 Dandelion seeds create a bizarre whirlpool in the air to fly
When you’re essentially a little ball of floof, flying is hard. Hairlike filaments help spawn the swirling vortex and create drag. To ride the wind, dandelion seeds stir up a weird type of whirlpool in the air directly above them. The newly discovered way of moving through the air, described October 17 in Nature, resolves a long-standing question about how the seeds stay aloft. Dandelion seed flight is not unlike the flight of Mary Poppins: Utterly charming, yet inexplicable when it comes to physics — until now. When a gust of wind plucks a seed from the plant’s fuzzy head, a fluffy structure called the pappus keeps the seed aloft before it ultimately falls to the ground. The structure, which extends from the seed, is made up of tiny hairlike filaments, making it mostly empty space. “It’s a weird structure,” says coauthor Naomi Nakayama, a biophysicist at the University of Edinburgh. “Nobody really knew how it could fly.” So Nakayama and her colleagues dug into the weeds. High-speed video and mathematical simulations revealed that the pappus filaments act together like a uniform sheet or a parachute and create drag — a force that counters gravity. Air also flows around the pappus and gets sucked into the area just above it. This air forms a swirling bubble that the researchers call a separated vortex ring, which adds to the drag.
10-17-18 The water system that helped Angkor rise may have also brought its fall
Monsoon floods and decades of drought were too much for the infrastructure to bear. At the medieval city of Angkor, flooding after decades of scant rainfall triggered a devastating breakdown of the largest water system in the preindustrial world, new evidence suggests. Intense monsoon rains bracketed by decades of drought in the 1400s set off a chain reaction of failures in Angkor’s interconnected water network, computer simulations indicate. The climate-induced crumbling of the system — used for irrigation, drinking water and flood control — hastened Angkor’s demise, scientists conclude online October 17 in Science Advances. “Angkor’s critical [water] infrastructure acted to accelerate the impact of climatic disruption,” says study coauthor and geoscientist Dan Penny of the University of Sydney. Complex infrastructure systems, from Angkor’s water network to modern electrical grids, consist of many interacting parts. Troubles in one part of a system can lead to the failure of other components.
10-17-18 World’s oldest fossils might turn out to just be ancient rocks
In 2016, researchers unveiled 3.7-billion-year-old fossils – a reassessment suggests the ‘fossils’ are actually physical scars left when the rocks were deformed. The oldest fossils in the world might not be anything of the kind. Instead they may simply be deformed rocks, reopening the question of when life began to leave its mark in the fossil record. However, even if the fossils are not real, other evidence still suggests that life began early in Earth’s history. For decades, palaeontologists have been on the hunt for ever-older fossils. The oldest accepted fossils are those from Strelley Pool in the Pilbara region of western Australia. They are stromatolites: preserved mats of microorganisms sandwiched between layers of sediment. The fossils are 3.4 billion years old. But some research teams claim to have found older fossils. In 2016 Allen Nutman at the University of Wollongong in Australia and his colleagues made one of the most prominent claims. They described stromatolites from rocks in Greenland that are 3.7 billion years old. Most rocks that old have at some point been carried deep into the Earth, where heat and pressure destroy fossils. But Nutman’s team found a patch of rocks that appears to have passed through this “metamorphism” relatively unharmed: it seemed to still partially preserve fossils.
10-17-18 These ancient mounds may not be the earliest fossils on Earth after all
A new look at 3.7-billion-year-old structures suggests tectonics, not life, formed them. Tiny mounds touted as the earliest fossilized evidence of life on Earth may just be twisted rock. Found in 3.7-billion-year-old rocks in Greenland, the mounds strongly resemble cone-shaped microbial mats called stromatolites, researchers reported in 2016. But a new analysis of the shape, internal layers and chemistry of the structures suggests that the mounds weren’t shaped by microbes but by tectonic activity. The new work, led by astrobiologist Abigail Allwood of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., was published online October 17 in Nature. The further back in time you go, the more devilishly difficult it is to identify signs of life. Allwood herself is familiar with the skepticism that comes with making such a big claim: In 2006, she and colleagues suggested that 3.45-billion-year-old rock features found in Australia’s Strelley Pool Chert were stromatolites. Though that claim was met with skepticism initially, a growing body of research has ultimately supported it. Then, in a 2016 paper in Nature, geologist Allen Nutman of the University of Wollongong in Australia and colleagues reported finding a series of reddish mounds within a group of ancient Greenland rocks known as the Isua supracrustal belt. Most of the belt has been twisted over time by tectonic forces. But Nutman and colleagues discovered the mounds within a portion of the belt that appears relatively unaltered, and the team presented numerous lines of evidence suggesting the structures were actually stromatolites (SN: 10/1/16, p. 7). If true, the discovery would push back the date of the earliest fossilized evidence of life by some 250 million years.
10-17-18 Human placenta stem cells help people recover from hip surgery
The placenta is usually discarded after childbirth but it's a source of mesenchymal stem cells – and they help people regain muscle strength after hip surgery. STEM cells taken from placentas have healing properties that can help people recover from having their hip joint replaced. Placentas are normally thrown away after childbirth, but now Israeli company Pluristem has taken discarded placentas and developed a batch of mesenchymal stem cells from them. These cells have the potential to turn into different kinds of tissue and release chemicals that promote healing. To see how the cells affect muscle repair, Tobias Winkler of Charité – Berlin University of Medicine in Germany and his colleagues tested two different doses of the cells in 20 people having hip replacements. During the operation, surgeons have to cut into muscle tissue around the joint, which can leave people limping for several months, particularly if it isn’t their first hip replacement. Six months after surgery, people who got a dose of cells had stronger hip muscles than those in the placebo group, as measured by an exercise machine (Journal of Cachexia, Sarcopenia and Muscle, doi.org/cvsw). All of the people in the experiment – even those in the placebo group – were limp-free by the time they were tested at six months, probably because everyone was having their first hip surgery, says Winkler. The improvements seen in strength suggest that the cells would reduce limping in people having second or third joint replacements, where the muscle starts off in worse condition, says Winkler.
10-17-18 Male birds can be good singers or good looking, but not both
The prettier the bird, the worse it sings. A study of over 500 species has revealed that birds evolve to attract mates in one of two ways, and don’t combine them. The call of a male peacock is no pleasure to listen to, but its splendid tail means it doesn’t matter. Now an analysis of more than 500 species shows that this is a common trade-off in the bird world: the best lookers aren’t the most talented singers, while the best vocalists aren’t as easy on the eye. Sexual selection is an evolutionary process that shapes traits that animals use to attract mates, and birds are well known to resort to elaborate songs and flashy feathers in the name of reproduction. To investigate which species use which traits, Christopher Cooney at the University of Oxford and his colleagues collected the songs of 518 species, and compared these with their feather colours. In particular, they looked at how much feathers differed between the males and females of each species – a sign that sexual selection has influenced their plumage. They found that birds in which one sex has more showy plumage than the other tend to have less interesting, more monotonous songs. In species in which the males and females more closely resemble each other, the males sing longer songs over a larger range of musical notes.
10-16-18 A mysterious polio-like disease has sickened as many as 127 people in the U.S.
There is no cure for acute flaccid myelitis, and the CDC can’t figure out what’s causing it. U.S. health officials are investigating an outbreak of a mysterious, polio-like disease that causes weakness in one or more limbs. The rare disease — acute flaccid myelitis, or AFM — has sickened 62 people, mostly children, in 22 states so far this year and is suspected in 65 more cases, the U.S. Centers for Disease Control and Prevention announced October 16. Starting with an outbreak of 120 cases that brought the disease to national attention in 2014, close to 400 cases have been confirmed in the United States. So far, the CDC has been unable to figure out what’s causing the outbreaks. “This is a mystery,” Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases in Atlanta, said during a news briefing. “We haven’t solved it yet.” Although the disease is frightening, fewer than one in a million people in the United States get AFM every year, based on CDC data collected since 2014. “Parents need to know that acute flaccid myelitis is very rare, even with the increase in cases that we’re seeing now,” she said. Even so, the CDC recommends that patients who develop sudden weakness in their arms or legs seek immediate medical care.
- What is acute flaccid myelitis? The disease targets the spinal cord, leading to arm or leg weakness and loss of muscle tone.
- What causes AFM? The CDC is investigating viruses and environmental toxins as possible causes, but has yet to find a single agent responsible for the peaks in cases this year and in 2014 and 2016, when 149 cases were confirmed.
- Is there a treatment for AFM? There is no cure or specific medical treatment for AFM.
- Are there factors that increase the risk of AFM? That still isn’t known.
10-16-18 To unravel autism’s mysteries, one neuroscientist looks at the developing brain
Understanding how the disorder arises could lead to new interventions. As the number of children diagnosed with autism spectrum disorder increases, so too has research on the complex and poorly understood disorder. With powerful genetic tools, advanced brain-imaging methods and large groups of children to study, the field is poised to make big contributions in understanding — and potentially treating — autism. Neuroscientist Kevin Pelphrey, who is formerly of George Washington University in Washington, D.C., but has recently moved to the University of Virginia in Charlottesville, studies autism’s beginnings. He described some of his findings about the link between brain development and the disorder on October 15 at a meeting of the Council for the Advancement of Science Writing. Here are some of the key points Pelphrey made on how autism may get its start in the developing brain, how the disorder is different between boys and girls, and how large, long-term studies of children with autism might yield clues about the condition.
- What causes autism spectrum disorder? For most cases, no one knows. There’s likely no single cause — environmental and genetic risk factors work in combination.
- When does the disorder begin? On average, kids are diagnosed with autism around the age of 4, though symptoms can appear by around age 2. But Pelphrey says the disorder starts long before then, as the brain is built in utero (SN: 4/29/17, p. 10).
- How close are scientists to an autism biomarker? Biological signatures, or biomarkers, of autism might enable both earlier detection and a way to see if interventions to treat the disorder are working. In 2017, researchers found signatures of autism in the brains of 6-month-old babies who would go on to be diagnosed with the disorder at age 2.
- Why do more boys get autism diagnoses than girls? Researchers don’t yet know for sure. Scientists recently began studying the differences between boys and girls, in the hopes of explaining why an estimated four boys are diagnosed with autism for every girl diagnosed.
- What’s the future of autism research? Autism is an idiosyncratic disorder, one that’s likely a bit different for each person. As such, making progress toward understanding common pathways will require large numbers of subjects and many types of measurements.
10-16-18 Nicotine exposure in male mice may trigger ADHD in their offspring
Mice are more active and have attention problems if their fathers had nicotine in their diet, perhaps because the chemical triggers epigenetic changes in sperm. Nicotine exposure has negative effects that echo down the generations – in mice, at least. Male mice exposed to nicotine had offspring with signs of a mouse version of attention deficit hyperactivity disorder (ADHD). Previous studies have emphasised that women risk the health of their children by smoking during pregnancy. It has been linked to their children’s risk of developing depression, asthma and polycystic ovary syndrome. There has been less focus on the effects of paternal cigarette use on the health of children, so Pradeep Bhide at Florida State University and his colleagues decided to investigate. They added nicotine to the water supply given to 12 male mice and, after 12 weeks, mated the males with females that had never been exposed to nicotine. None of the resulting offspring were ever directly exposed to nicotine. The team found these offspring were 30 to 50 per cent more active than expected. They also made at least 50 per cent more mistakes than mice usually do when trying to escape from a maze they had been familiarised with. Moreover, sons, but not daughters, of nicotine-exposed fathers spent less time exploring new objects — an indicator of attention deficiency.
10-16-18 Lab-grown oesophagus implanted in mice
Scientists in London have grown a bio-engineered oesophagus which was successfully implanted into mice. The work, published in Nature Communications, was led by scientists at UCL Great Ormond Street Institute of Child Health (ICH), Great Ormond Street Hospital (GOSH) and the Francis Crick Institute. The team hopes the research could eventually lead to clinical trials of lab-grown food pipes for children born with part of their oesophagus damaged or missing. The oesophagus is a complex, multi-layered organ, made up of multiple tissue types, which acts as a pipe carrying food and liquid from the mouth to the stomach. The team used a rat oesophagus, which was stripped of its cells, leaving behind a collagen scaffold. They seeded it with early-stage muscle and connective tissue from mice and humans, and other early rat cells which went on to form the lining on the inside of the organ. The use of stem cells from different species enabled researchers to differentiate between the origin of each tissue type which developed. The 2cm sections of oesophagus were implanted into the abdomen of mice. Dr Paola Bonfanti, co-author and group leader at the Francis Crick Institute and UCL Great Ormond Street Hospital Institute of Child Health (ICH), said: "We were amazed to see that our engineered tissue had both the structure and function of a healthy oesophagus, and hooked up with nearby blood vessels within a week of transplantation." The sections of oesophagus were capable of muscle contraction, which is needed to move food down to the stomach. Around one in 3,000 babies is born with abnormalities of the oesophagus, usually involving a gap between the upper and lower section, or where it does not connect with the stomach.
10-16-18 People who have a good sense of smell are also good navigators
Scientists have connected both skills to the same areas in the brain. We may truly be led by our noses. A sense of smell and a sense of navigation are linked in our brains, scientists propose. Neuroscientist Louisa Dahmani and colleagues asked 57 young people to navigate through a virtual town on a computer screen before being tested on how well they could get from one spot to another. The same young people’s smelling abilities were also scrutinized. After a sniff of one of 40 odor-infused felt-tip pens, participants were shown four words on a screen and asked to choose the one that matched the smell. On these two seemingly different tasks, the superior smellers and the superior navigators turned out to be one and the same, the team found. Scientists linked both skills to certain spots in the brain: The left orbitofrontal cortex and the right hippocampus were both bigger in the better smellers and better navigators. While the orbitofrontal cortex has been tied to smelling, the hippocampus is known to be involved in both smelling and navigation. A separate group of 9 people who had damaged orbitofrontal cortices had more trouble with navigation and smell identification, the researchers report October 16 in Nature Communications. Dahmani, who’s now at Harvard University, did the work while she was at McGill University in Montreal. A sense of smell may have evolved to help people find their way around, an idea called the olfactory spatial hypothesis. More specific aspects of smell, such as how good people are at detecting faint whiffs, could also be tied to navigation, the researchers suggest.
10-16-18 An ancient child’s ‘vampire burial’ included steps to prevent resurrection
The 10-year-old’s skeleton had a stone placed in the mouth. Excavations in an ancient Roman cemetery turned poignantly eerie last summer. In one grave lay a roughly 10-year-old child, possibly the victim of malaria, with a stone inserted in his or her mouth. That practice was part of a funeral ritual intended to prevent the youngster from rising zombielike and spreading disease to the living, researchers say. Such "vampire burials" indicate signs of a belief among people of the time that the dead could come back to life. The discovery of this vampire burial occurred at the Cemetery of the Babies, a mid-fifth century site in central Italy. Classical archaeologist David Pickel of Stanford University led the excavation. The results, announced in an Oct. 11 statement, will be presented in January at the Archaeological Institute of America’s annual meeting in San Diego. A malaria outbreak in the region killed many babies and young children around the time of the child’s burial. Of more than 50 previously excavated graves at the cemetery, the oldest remains were those of a 3-year-old child. Bones of several kids buried there have yielded DNA of malaria parasites. Several other vampire burials have been found previously, including a 16th century Venetian woman buried with a brick in her mouth and a man from third or fourth century England whose tongue had been cut out and replaced with a stone.
10-16-18 Alien life could spread between solar systems on interstellar rocks
Researchers have calculated that living organisms may be able to hitch a ride aboard interstellar rocks to spread not only between planets, but across the galaxy. Life finds a way – perhaps even across the stars. It may be possible for organisms to travel all over the galaxy by hitching a ride on a fast-moving rock in a phenomenon called galactic panspermia. In this way, just a few inhabited worlds could spread life throughout the Milky Way. In October 2017, astronomers spotted the first interstellar object we have ever seen come through our solar system, called ‘Oumuamua. That was the first concrete proof that rocks can be tossed out of orbit from distant stellar systems and make it intact to our solar system. Of course, it is not enough for a space rock to travel between the stars. In order to transfer life, it must also be captured by the sun’s gravity and eventually smash into a planet. Now, Idan Ginsburg, Manasvi Lingam and Avi Loeb at Harvard University have calculated just how often these banished rocks might be captured into a new stellar system, and how likely any life stuck on such interstellar projectiles would be to survive. “It’s like billiards,” says Ginsburg. “You hit the cue ball and it hits the other balls, and beside just transferring momentum it also spreads life, and then life spreads across the whole table, which is the galaxy.” The researchers found that up to 100 million life-bearing objects with a radius of 200 kilometres – about half the size of Saturn’s moon Enceladus – could have been captured in stellar systems around the Milky Way. Even about 1000 Earth-sized objects could have been captured in this way, they say. (Webmaster's comment: So if this has been going on for the last 8-12 billion years where are the results?)
10-16-18 Explore the history of blood from vampires to the ‘Menstrual Man’
Nine Pints offers engaging and insightful stories about the life-giving substance. The title of journalist Rose George’s new book, Nine Pints, quantifies how much blood George has flowing through her body. Her supply takes a temporary dip in the book’s opening chapter, when she donates about a pint (a story that continues on to recap the amazing accomplishment that is blood banking). This act of generosity is an appropriate kickoff to the bounty of knowledge and insight that George shares about blood as she mines its cultural and scientific history. Blood, George notes, is revered, feared and mysterious — the stuff of legend. Chief among the legends are vampires, which, naturally, make an appearance in the book. But in George’s hands, ancient tales of purported blood sucking lead readers to modern-day experiments examining whether blood can truly bring youth and health when transferred to the old or sick (SN: 12/27/14, p. 21). George’s bright writing and companionable tone, along with a healthy dose of skepticism, make her a welcome guide to the past and the future of this giver and taker of life. Like blood circulating through the body, the book winds its way around the world, exploring myths, facts and scientific discoveries about blood. The cast of characters includes Welsh leech handlers; HIV patients and clinic staff in South Africa; the British physiologist Janet Vaughan, who was instrumental in establishing blood transfusion stations during World War II; and Arunachalam Muruganantham, the “Menstrual Man” who devised a low-cost method to produce sanitary pads in India in the 2000s.
10-16-18 Electric chewing gum zaps your tongue to create a virtual flavour hit
An 'unlimited chewing gum' uses an electric charge to trick you into experiencing flavours – and they don’t fade in the way chewing gum flavour usually does. Chewing gum that zaps your tongue with electricity keeps the flavour going forever. The pain-free device is called “unlimited electric gum”. It uses the piezoelectric effect – a phenomenon where some materials produce electric charge when squeezed. When the “gum” is chewed, it produces a small current, which tricks the tongue into experiencing different tastes. It currently produces a salty or bitter taste. But the hope is to extend that, since other research has shown that, by varying the pattern and strength of electric charge, it is possible to induce all five of the basic tastes our mouths pick up: bitter, salty, sour, sweet and umami. At an event in Japan earlier this year, 80 people tried the gum. Almost everyone reported experiencing salty or bitter tastes. Some said chewing it was a bit like chewing niboshi, which are small dried infant sardines used in snacks and seasonings in Japan. The gum consists of a piezoelectric element and electrodes, wrapped in a thin plastic film. It’s a couple of centimetres wide, like a standard stick of gum. Unlike real chewing gum, the electric version will continue to stimulate the taste buds for as long as it is chewed – and it won’t break down into a sticky glob. (Webmaster's comment: Sounds completely unappetizing to me.)
10-16-18 The 'ugly duckling' fossil from the deep
The mosasaurs recently took a star turn in the Jurassic World movie, showing off the Hollywood version of their fearsome jaws. Now an "ugly duckling" from 85 million years ago is shedding new light on the giant marine reptiles that lived at the time of Tyrannosaurus rex. Scientists have long puzzled over how the diminutive fossil fitted into the family tree. They now think it was still developing the distinctive long snout of its clan. Takuya Konishi, a biology professor at the University of Cincinnati, took a second look at a small fossil unearthed more than 25 years ago in a rock formation in Kansas. He found a protruding snout - the telltale sign of a Tylosaurus, a type of mosasaur that grew up to 13m in length. "The degree of snout development was nowhere near that of an adult," he said. "It was the ugly duckling that hadn't yet become the graceful swan." Mosasaurs gave birth to free-swimming live young. The newborns might have had a different diet until they were fully grown, said Prof Konishi. "It was hunting in a very different way from adults and adolescents. Maybe it was just going for smaller-size fish - a foot long at most."
10-15-18 Earliest ever animal fossil is a 660-million-year-old sponge
Chemical evidence locked in rocks and oil suggests that the first animals were alive 100 million years earlier than we thought from fossils. Sponges were probably one of the earliest animal groups to evolve – but researchers have had trouble working out exactly when in geological time they appeared. Now, an analysis of ancient rocks and oils has turned up traces of steroids made by early sponges that indicate they may have been populating the ancient seafloor at least 120 million years earlier than we thought. “If animals first appeared in a predominantly bacterial or microbial world, they would need to harness microbes and live symbiotically with them,” says Gordon Love at the University of California, Riverside. That may be why sponges produce a vast array of sterols – steroids with anti-bacterial properties that could let them harbour microbes without harm. The earliest sponges belong to a class called demosponges, which transform sterols into a compound called sterane that can be fossilised. Love and his team went hunting for these ‘molecular fossils’ in rock and oil samples from Oman, Siberia and India that date to between 660 and 635 million years old. They found an abundance of a sterane called 26-methylstigmastane, or 26-mes, that as far as we know is only produced by demosponges. Love and his colleagues used high-pressure hydrogen to break down organic polymers that bind this compound to the rocks it was embedded within, while preserving the molecular structure.
10-15-18 Wheat flour to be fortified with folic acid in the UK
Folic acid helps prevent birth defects but is most effective taken around the time of conception. Adding it to wheat could benefit unplanned pregnancies. Flour in the UK is to be fortified with folic acid in a move to help reduce brain and spine birth defects, reports suggest. Medics have long called for the move, saying that it could reduce the incidence of conditions caused by abnormal development of the neural tube. Pregnant women, and those trying to conceive, are urged by health officials to take a daily supplement of 400 micrograms of folic acid, at least until the 12th week of pregnancy. But many women do not take the supplements – especially if a pregnancy is unplanned. A possible solution to this is fortifying wheat flour with folic acid, so that the nutrient – also known as vitamin B9 – is available in bread. Most flour in the US and Canada has been fortified since the 1990s. When fortification first began in Canada, neural tube defects – which include spina bifada and anencephaly – halved. Flour is also fortified in Australia. On 14 October, The Guardian reported that UK ministers have now backed a plan to fortify flour in the UK. Clare Livingstone, of the Royal College of Midwives, welcomed the news, saying that folic acid is most effective when taken right at the start of pregnancy. “Many pregnancies are not planned, meaning many women will not have taken folic acid around the time of conception and very early in their pregnancy,” she says. The sooner the government introduces fortification, the sooner fewer babies will be born with neural tube defects, says Livingstone.
10-13-18 South Africa's ancient lost city of Kweneng rediscovered by lasers
Archaeologists using laser technology have rediscovered an ancient city outside South Africa's commercial capital of Johannesburg. The settlement, which dates back to the 15th Century, was home to up to 10,000 people from the Tswana ethnic group. Their descendants are now fighting to have the city of Kweneng recognised as their homeland.
10-13-18 The history of loneliness
This Western problem may have a solution if we look to the past. "God, but life is loneliness," declared the writer Sylvia Plath in her private journals. Despite all the grins and smiles we exchange, she says, despite all the opiates we take: "When at last you find someone to whom you feel you can pour out your soul, you stop in shock at the words you utter — they are so rusty, so ugly, so meaningless and feeble from being kept in the small cramped dark inside you so long." By the 21st century, loneliness has become ubiquitous. Commentators call it "an epidemic," a condition akin to "leprosy," and a "silent plague" of civilization. This year, the U.K. went so far as to appoint a Minister for Loneliness. Yet loneliness is not a universal condition; nor is it a purely visceral, internal experience. It is less a single emotion and more a complex cluster of feelings, composed of anger, grief, fear, anxiety, sadness, and shame. It also has social and political dimensions, shifting through time according to ideas about the self, God, and the natural world. Loneliness, in other words, has a history. The term "loneliness" first crops up in English around 1800. Before then, the closest word was "oneliness," simply the state of being alone. As with solitude — from the Latin "solus" which meant "alone" — "oneliness" was not colored by any suggestion of emotional lack. Solitude or oneliness was not unhealthy or undesirable, but rather a necessary space for reflection with God, or with one's deepest thoughts. Since God was always nearby, a person was never truly alone. Skip forward a century or two, however, and the use of "loneliness" — burdened with associations of emptiness and the absence of social connection — had well and truly surpassed oneliness. What happened?
10-12-18 Sleep-deprived teenagers
Teenagers who don’t get enough sleep are more likely to engage in risky and even suicidal behavior, according to a new study. Researchers examined surveys completed by 68,000 high school students between 2007 and 2015. They found that, compared with teenagers who got the recommended minimum of eight hours of sleep a night or more, students who slept less than six hours were roughly twice as likely to drink alcohol, smoke, use drugs, or engage in risky sexual behavior. They were also three times more likely to engage in self-harm and consider or attempt suicide. Those who slept six to seven hours a night were also more likely to engage in unsafe behaviors than those who hit the eight-hour mark; overall, more than 70 percent of the students weren’t getting the recommended eight to 10 hours. Lead author Matthew Weaver, from the Brigham and Women’s Hospital in Boston, tells Reuters.com it’s possible that sleep deprivation may cause changes in the brain that lead to “more impulsive and emotionally driven decisions.”
10-12-18 Hundreds of dietary supplements are tainted with potentially harmful drugs
Fewer than half of these products were recalled by their makers. From 2007 to 2016, the U.S. Food and Drug Administration flagged nearly 800 over-the-counter dietary supplements as tainted with potentially harmful pharmaceutical drugs, a study shows. Fewer than half of those products were recalled by their makers, scientists found. Researchers analyzed the FDA’s public database of tainted supplements, identifying both the type of contaminating ingredients they contained and how the products were marketed. Most of these supplements, which are allowed to contain only dietary ingredients, included drugs such as steroids, the active ingredient in Viagra and a weight loss drug banned from the U.S. market eight years ago. The products had been marketed primarily for sexual enhancement, weight loss or muscle building, scientists report online October 12 in JAMA Network Open. More than half of American adults have reported taking dietary supplements, such as vitamins, minerals and other specialty products. More than 85,000 supplements are estimated to be available in the United States, and the FDA says it cannot test all of them. These supplements aren’t subject to the same regulations, testing and approval process that are required for pharmaceutical drugs. But if the FDA identifies tainted supplements after they’re on the market, the agency can issue public warnings or suggest the company voluntarily remove the product.
10-12-18 Genealogy databases could reveal the identity of most Americans
Keeping your DNA private is getting harder. Protecting the anonymity of publicly available genetic data, including DNA donated to research projects, may be impossible. About 60 percent of people of European descent who search genetic genealogy databases will find a match with a relative who is a third cousin or closer, a new study finds. The result suggests that with a database of about 3 million people, police or anyone else with access to DNA data can figure out the identity of virtually any American of European descent, Yaniv Erlich and colleagues report online October 11 in Science. Erlich, the chief science officer of the consumer genetic testing company MyHeritage, and colleagues examined his company’s database and that of the public genealogy site GEDMatch, each containing data from about 1.2 million people. Using DNA matches to relatives, along with family tree information and some basic demographic data, scientists estimate that they could narrow the identity of an anonymous DNA owner to just one or two people. Recent cases identifying suspects in violent crimes through DNA searches of GEDMatch, such as the Golden State Killer case (SN Online: 4/29/18), have raised privacy concerns (SN Online: 6/7/18). And the same process used to find rape and murder suspects can also identify people who have donated anonymous DNA for genetic and medical research studies, the scientists say.
10-12-18 Mayan structures unearthed
Archaeologists have uncovered tens of thousands of ancient Mayan structures in Guatemala, using a groundbreaking new laser-mapping technology. The researchers flew over 830 square miles of dense forest in a plane equipped with a lidar device, which rained millions of light pulses on the canopy to reveal the contours of the ground beneath. The survey revealed an astonishing 61,480 Mayan structures, many of them never seen before. There were large houses and temples; 60 miles of causeways, roads, and canals; even defensive fortifications, such as moats, which suggest the Maya came under attack from other Central American peoples. The discoveries provide a unique snapshot of the Maya, who lived in the region from about 1000 B.C. to 1500 A.D., and should help scientists understand more about their population size, agricultural techniques, and conflicts. After analyzing the scans, the researchers explored the jungle at ground level to verify some of their findings. “We were all humbled,” lead author Marcello Canuto, from Tulane University in New Orleans, tells The Washington Post. “All of us saw things we had walked over, and we realized, ‘Oh wow, we totally missed that.’”
10-12-18 T. rex may have used its long feet for stealthy surprise attacks
Carnivorous dinosaurs generated seismic waves with every footfall – but because of the shape of their feet they may have masked their presence approaching prey. Tyrannosaurus rex was so large and heavy that it’s easy to assume that the ground shook as it approached. But, paradoxically, it might have used those tremors to its advantage: the shape of its feet suggests the seismic waves from each footfall remained similar in intensity as it approached its prey, acting as a weird form of camouflage. Heavy animals produced earthquake-like seismic waves with every footfall. We know that other animals detect those seismic signals: elephants listen and respond to the seismic waves generated by foot stomps and low-frequency vocalisations. Large dinosaurs must have produced seismic waves too. Ernesto Blanco at the University of the Republic, Uruguay, and his colleagues decided to explore how they might have been harnessed. They analysed a total of 64 fossilised footprints left by several large dinosaurs including herbivores, omnivores, and carnivorous theropods – a group that includes T. rex. The researchers says that theropods typically had elongated feet with a length-to-width ratio of 2, while omnivorous and herbivorous dinosaurs had feet with a length-to-width ratio closer to 1. Blanco and his colleagues simulated the pattern of seismic waves generated when the dinosaur feet hit the ground. They found the waves produced by theropod feet were weakest in the walking direction: in other words, theropods had a foot shape that would have allowed them to sneak up on their prey while ‘seismically’ masking their presence.
10-12-18 A huge new dinosaur
Paleontologists in South Africa have discovered the fossilized remains of a gigantic new species of dinosaur related to the brontosaurus. Ledumahadi mafube was an early type of sauropodomorph, a group of long-necked, long-tailed dinosaurs that lived about 200 million years ago in the early Jurassic period. Weighing 26,000 pounds—about as much as two adult African elephants—and standing 13 feet high at the hips, it was the largest land animal on the planet at the time. Researchers believe that Ledumahadi mafube, whose name means “a giant thunderclap at dawn” in the Sesotho language, walked on all fours in a cat-like crouch. That posture was very different from its later, straight-limbed relatives’, meaning the dinosaur was effectively an evolutionary experiment. Some of its fossilized bones were found in 1990, but the paleontologist who excavated them was interested in mammals, not dinosaurs, so they went unstudied for years. “It’s amazing,” study co-author Jonah Choiniere, from the University of the Witswatersrand in Johannesburg, tells NationalGeographic.com. “Sometimes stuff can sit on your shelf, and you pass by it every day, but you don’t look at it in detail.”
10-12-18 C-section births surge to 'alarming' rates worldwide - study
Doctors' use of Caesarean section to deliver babies has nearly doubled in 15 years to reach "alarming" proportions in some countries, a study says. Rates surged from about 16 million births (12%) in 2000 to an estimated 29.7 million (21%) in 2015, the report in the medical journal The Lancet said. The nation with the highest rate for using the surgery to assist childbirth is the Dominican Republic with 58.1%. Doctors say in many cases the use of the medical procedure is unjustified. Until recently, the World Health Organization (WHO) suggested that Caesarean section - or C-section - rates of more than 15% were excessive. The study analysed data from 169 countries using statistics from 2015 - the most recent year for which the information is available. It says there is an over-reliance on Caesarean section procedures - when surgery is used to help with a difficult birth - in more than half of the world's nations. Researchers reported a rate of more than 50% in the Dominican Republic, Brazil, Egypt and Turkey, though Brazil implemented a policy in 2015 to reduce the number of Caesarean sections performed by doctors. They also found huge disparities in the use of the technique between rich and poor nations. In some circumstances, particularly in sub-Saharan Africa, the surgery is unavailable when it is genuinely required. Use in 2015 was up to 10 times more frequent in the Latin America and Caribbean region, at 44% of births, than in the west and central Africa region, where it was used in just 4% of cases. The study urges healthcare professionals, women and their families to only choose a Caesarean when it is needed for medical reasons - and for more education and training to be offered to dispel some of the concerns surrounding childbirth. (Webmaster's comment: 1/3 of births in the US are C-section. We are de-evolving our ability to have children in the normal way.)
10-12-18 Rice 'safely conserved' in Philippines gene bank
Scientists say that more than 100 thousand varieties of rice have been safeguarded for the future. Samples in the world's largest rice gene bank in the Philippines are being used to help farmers develop rice crops that can survive drought and flooding. The International Rice Research Institute (IRRI) gene bank has secured permanent funding from the Crop Trust. It is part of international efforts to store seeds in gene banks to protect food supplies in a warming world. "These seeds are miracles - we believe that in this natural diversity of rice you have almost any trait that you would want to look for," said Marie Haga, executive director of the international non-profit organisation, the Crop Trust. She said rice is relatively easy to store, and should survive preservation for hundreds of years at low temperatures. The rice contains the genetic diversity that can be used to breed new rice crops capable of withstanding pests and disease as well as flooding and drought. One recent advance from IRRI, which is based in Los Banos, Philippines, is a strain of rice that can survive areas hit by flooding. Ruaraidh Sackville-Hamilton, an evolutionary biologist who manages the IRRI genebank, said the work to conserve rice has a proven track record in bringing benefits to the world. "With this collection safely conserved, we can continue to use it to develop improved rice varieties that farmers can use to respond to the challenges in rice production, and to adapt to the changing tastes and preferences of consumers everywhere," he said.
10-12-18 We can harness algae with magnets to deliver drugs inside our bodies
If we attach tiny magnets to fast-swimming algae, we can load them up with drugs and steer them deep into the human body to deliver targeted medical therapies. Algae aren’t just scum on the top of a lake: some of the microbes can swim surprisingly fast – outpacing even the micromachines designed to one day deliver drugs inside the human body. Now comes evidence that the alga could be harnessed relatively easily for such speedy drug delivery. Metin Sitti at the Max Planck Institute for Intelligent Systems in Germany and his colleagues figured out a way to yoke an alga like an ox and then steer it through the body using magnetic fields as the reins. They started by attaching spherical magnets just one micrometre across to a single freshwater alga. Then they could control the alga’s direction as it swam along by applying a magnetic field, which pulled the tiny magnets in whatever direction they want the alga to go. “It’s a cyborg-like system,” says Sitti. The idea is to load the algae up with medication and then steer them through the body to diseased tissue for a targeted response, rather than simply drugging the whole surrounding area or the entire body, which can have unpleasant side effects. The algae can swim over 100 micrometres per second, much faster than many other microswimmers that have been proposed for drug delivery. Sitti and his team found that the algae can swim in the fluid within Fallopian tubes, and also in both plasma and blood. What’s more, they are biocompatible with human cells.
10-12-18 Police can now use millions more people’s DNA to find criminals
Consumer genetic databases are becoming powerful tools for identifying criminals, and a new technique could link you to forensic data held by US police. Policing power may be about to get much stronger, thanks to another advance in genetic analysis. A new technique can link the patchy, limited DNA information held in forensic databases to the rich DNA libraries held by family tree-building websites, raising further questions about genetic privacy. Earlier this year, an ancestry database used by people looking to trace their family history was used to identify the suspected Golden State Killer, a serial killer active in California decades ago. Since his arrest in April, genealogy databases – which allow consumers to upload their DNA sequences – have been used to crack several other cold cases. These stores of DNA data meant for consumers were needed because forensic databases hold only limited information. Now a new technique could link the two, further expanding police use of DNA data. The US national DNA database used by police and the FBI – called CODIS – doesn’t store whole DNA sequence data. Instead, it focusses on up to 20 specific stretches of repetitive DNA code. These regions vary between individuals, so can help identify people. But consumer genetic databases store different data instead – single-letter variations in DNA across hundreds of thousands of sites in the human genome. With more data points, you can more accurately pin down a person’s relationship to others.
10-12-18 Mice eat too much food if their great grandmother did the same
When mice are given a high-fat diet their great grandchildren are more likely to put on weight – and they show a greater than expected taste for alcohol. When a female mouse is fed a high-fat diet her children, grandchildren and great grandchildren have a greater risk of obesity and addiction — because of changes to the brain reward system. Diet can mess with the brain. Animal studies have shown that the offspring of mothers consuming a high-fat diet have a less sensitive reward system: they need to consume more food or pleasure-enhancing drugs to feel full or satisfied. Therefore, these individuals are more likely to become obese and addicted to drugs. Daria Peleg-Raibstein at the Swiss Federal Institute of Technology and her colleagues were interested in the effect of a high-fat diet on the second and third generation — grandchildren and great grandchildren. The team fed female mice with a high-fat diet for nine weeks: three weeks before they mated, and another six weeks through the subsequent pregnancy and lactation period. These mice did not become obese during the nine-week period. All offspring were offered a normal diet. Then, the males were mated with healthy females that had been born to “normal diet” mothers to produce a second generation of offspring. Finally, males from this second generation were mated with females from “normal diet” families to produce a third generation. The team found that the second- and third-generation mice had a 7 per cent greater body weight than expected for the diet they had been offered. They also had a greater than anticipated preference for drinking alcohol.
10-11-18 Gene editing creates mice with two biological dads for the first time
The rodents survived only a few days after birth. For the first time, researchers have created mice with two dads. No female contributed to the rodents’ genetic makeup. This unusual reproduction took place in a lab where researchers gathered fathers’ stem cells, and used them to produce embryos that were implanted into surrogate mothers. The technique required scientists to edit the animals’ genes in order for the mice to mature enough to be born. Even so, mouse pups with only fathers died a few days after birth, researchers report October 11 in Cell Stem Cell. By contrast, previous research and this study have shown that some gene-edited mice with only mothers can survive to adulthood and have offspring of their own. The researchers did the experiments to learn why mammals can reproduce only sexually — requiring two parents of the opposite sex — while other vertebrates, including turkeys, snakes and sharks, can sometimes reproduce with only one parent, says study coauthor Qi Zhou of the Chinese Academy of Sciences in Beijing. Females of those species can sometimes cause an unfertilized egg to produce offspring, a process called parthenogenesis. Researchers have previously made zebrafish with only an individual father’s DNA. But no one before now has reported achieving male-only reproduction, or androgenesis, with mammals.
10-11-18 We are a step closer to making babies with same-sex genetic parents
We are getting better at creating mice with same-sex parents but we are still nowhere near the point at which this could be attempted in people. We are a small step closer to the day when two women or two men could have biological children of their own, thanks to improved methods for creating mice with same-sex parents. But the work also shows that there is an enormous amount still to do before this could be attempted in humans. “It is never too much to emphasise the risks, and the importance of safety, before any human experiment is involved,” says Wei Li at the Chinese Academy of Sciences in Beijing. “But we think our work does take it closer.” The greatest obstacle to creating babies from parents of the same sex is a phenomenon called imprinting. In mammals, certain genes are switched off in the sperm genome, by adding epigenetic markers to the DNA. These markers don’t change the underlying DNA sequence, but they ensure the gene is not expressed. Different genes are turned off in eggs. This is the result of a battle between the sexes, with males trying to boost the growth of their offspring at the expense of females, and females fighting back. Imprinting means that if you somehow combine the genomes of two females, or two males, in an egg and kickstart development, the resulting embryo will die. But in 2004 a team in Japan managed to create Kaguya the mouse – the first ever mammal with two mothers. They achieved this deleting a piece of DNA in one of the genomes to mimic the effect of imprinting – but 500 attempts produced just two mice that survived to adulthood.
10-11-18 See these dazzling images of a growing mouse embryo
A new microscope lets scientists peek into the mysterious process of mammalian development. A new microscope is giving researchers an unprecedented view of how mammals are built, cell by cell. Light sheet microscopes use ultrathin laser beams to illuminate sections of a specimen while cameras record those lit-up sections. Previous iterations of the device have captured detailed portraits of living zebra fish and fruit fly embryos as they develop. Kate McDole, a developmental biologist at Howard Hughes Medical Institute’s Janelia Research Campus in Ashburn, Va., and colleagues used a new-and-improved version to monitor the development of a larger, more complex organism: the mouse. Algorithms in the microscope tracked six-day-old mouse embryos in real time over roughly two days, keeping the device focused on the cell clusters as they grew. A suite of computer programs used the data — about a million images per embryo — to map the life history of each embryo’s every cell, the team reports October 11 in Cell. The result: dazzling views of mouse organs taking shape. As an embryo rapidly expands in size, the gut starts to form when part of the embryo collapses into a craterlike hole. And a structure that eventually forms the brain and spinal cord, called a neural tube, appears like a comet shooting across the night sky. Researchers also captured the first beats of heart cells.
10-11-18 Same-sex mice have babies
Baby mice have been made with two mums and no dad, say researchers at the Chinese Academy of Sciences. It took a substantial feat of genetic engineering to break the rules of reproduction. The scientists said the "bimaternal" (two mammas) animals were healthy and went on to have pups of their own. But there was bad news on the all-male front. Mice with double-dads were attempted, but died within days of being born. The researchers were trying to answer fundamental questions about why we have sex. Mammals, including us, can make babies only through sexual reproduction - aka you need an egg from mum and a sperm from dad. But the rest of the natural world doesn't play by the same rules; some female fish, reptiles, amphibians and birds can go it alone. Welcome to the bizarre world of virgin births known officially as parthenogenesis. The aim of the Chinese researchers was to work out which rules of reproduction they needed to break to make baby mice from same-sex parents. That in turn helps understand why the rules are so important. "It's an interesting paper... they're trying to work out what you would have to do to turn us into turkeys," said Prof Robin Lovell-Badge at the Francis Crick Institute. It was easier with double mums. The researchers took an egg from one mouse and a special type of cell - a haploid embryonic stem cell - from another. Both contained only half the required genetic instructions or DNA, but just bringing them together wasn't enough. The researchers had to use a technology called gene editing to delete three sets of genetic instructions to make them compatible (more on that later). The double-dad approach was slightly more complicated. It took a sperm, a male haploid embryonic stem cell, an egg that had all of its own genetic information removed and the deletion of seven genes to make it all work.
10-11-18 Humongous fungus is older than Christianity and weighs 400 tonnes
A gigantic fungus that lives under the ground in a Michigan forest is even larger than initially estimated and may have been around for at least 2500 years. A huge underground fungus that is one of the largest living organisms on the planet has turned out to be both bigger and older than thought. It may have been quietly spreading through the soil of Michigan since the end of the last ice age. James B. Anderson of the University of Toronto in Canada and his colleagues discovered the enormous Armillaria gallica fungus in the late 1980s, while studying fungi that were killing red pines on a Michigan plantation. “We found one genetic individual occupying this site,” says Anderson. It spanned at least 0.37 square kilometres. At the time they estimated it was at least 1500 years old and weighed at least 100,000 kilograms. They published their findings in 1992. At the time the fungus was a serious contender for the largest living organism, but bigger fungi have since been found. An individual of A. ostoyae in the Malheur National Forest in Oregon spans 9.6 square kilometres. Confusingly, the Michigan and the Oregon fungi are both informally called “the humongous fungus”. Anderson and his colleagues have now revisited the fungus, which had been left to its own devices since the early 1990s. They collected 245 samples, far more than before, allowing them to get a better sense of its borders. It turns out the fungus weighs at least 400,000 kg, four times larger than the initial estimate. The fungus grew from a single individual, so its greater size implies it is also older than thought. “We’re now saying 2500 years based on our estimates of growth rate, and that’s a lower bound,” says Anderson.
10-11-18 75-million-year old ocean microbes live forever on almost zero energy
There is so little food in the mud at the bottom of the Pacific Ocean that individual microbes living there use just 0.00000000001 Joules of energy each year. Deep below the surface of the South Pacific Ocean, buried beneath 70 metres of seafloor sediment, there are microbes that may be about 75 million years old. These organisms are among the oldest known life forms on the planet, yet exactly how they manage to maintain their near-immortality has remained a mystery. James Bradley, a geobiologist at the University of Southern California, and his colleagues think they have solved the puzzle: to stay alive, the microbes stay mostly dead. They burn next to no energy. Researchers already knew that the microbes must have extremely low metabolisms, but it was unclear exactly how much food they have to burn to keep on going. “We haven’t been able to determine in a quantitative way whether they’ve been growing since they’ve been buried, or whether or not they’re lying dormant,” Bradley says. By producing a model that took into account factors such as the density of microbes in the sediment and the density of food in that sediment, Bradley and his team calculated the energy requirement of the microbes. “[It] is equivalent to the energy that is released by burning just two per cent of their carbon biomass per year,” he says. In absolute terms that’s 0.00000000001 (10-11) joules per year – Bradley says a human uses one hundred quintillion (1020) times more energy per year.
10-10-18 Traces of mystery ancient humans found lurking in our genomes
Prehistoric humans were sexual adventurers, mating with Neanderthals and Denisovans, but DNA studies reveal dalliances with populations we never knew existed. WE LEARN about our ancestors in many ways. Bones tell us what they looked like. Teeth reveal their diet. Tools, pots, art and other artefacts hold stories about their culture. Then, a decade ago, the first ancient genome was sequenced, opening a whole new window on our past – one that promised more intimate insights. The breakthrough famously revealed that Neanderthals got very cosy with humans. Since then, geneticists have been probing more and more fossils for evidence of past cross-species dalliances. The studies haven’t disappointed. But in an intriguing twist, they have started to kick up something unexpected: hidden inside genomes are signs of ancestors that we never knew existed. Geneticists call them “ghosts”. We have no physical record of these ancient hominins – no bones, no tools, no archaeological remains whatsoever. Yet the genetic code that they left within fossils of other hominins, and in living humans too, is offering profound and unprecedented insights into how our species came to be, and what the world was like at the time. The idea that each of our cells might contain fragments of genetic code from extinct species has been around for well over a decade. Then, in 2008, Svante Pääbo and his team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, pulled off the master stroke of teasing DNA out of millennia-old Neanderthal bones in quantities great enough to sequence. This provided an obvious way to find out if Homo sapiens had bred with Neanderthals (Homo neanderthalensis): you could simply look within the genomes of living people for DNA sequences with distinctly Neanderthal patterns of mutations. These comparative studies revealed that early humans had indeed mated with Neanderthals, and not just once. Current estimates are that the genomes of everyone except Africans are between 2 and 4 per cent Neanderthal.
10-10-18 You can recognise around 5000 faces, from family to celebrities
For much of human evolution our ancestors may have encountered only a few hundred people in their lives – but we can each recall about 5000 distinct faces. You can probably recall more faces than you might think. Most people can remember about 5000, according to a new study. “It’s surprising, in that it seems to be overkill,” says Rob Jenkins at the University of York in the UK. He points out that some people argue humans lived in groups of around 150 people for most of hominin evolutionary history, so it might make sense for us to recall about this number of faces. “It turns out that whatever mental equipment we have to solve that task seems to also do this for many thousands of faces.” He and his team asked 25 people to spend an hour writing down the people they knew personally for whom they could form a clear mental image of their face, including friends and family, people at school or work, neighbours, and people they might know from local shops or who take the same bus or train. On average, participants listed 40 people in the first 5 minutes and slowed to 21 people in the final 5 minutes. Based on this rate, Jenkins and his team calculated how many people each participant would have listed with unlimited time – on average it was 549 people. Then, they tested recognition of famous faces by showing the participants images of 3441 public figures from film, business, politics, sports and so on. Each participant saw two different pictures of each public figure on two separate days. If they said they recognised the celebrity in both pictures, that person was considered part of their ‘facial vocabulary’.
10-10-18 50 years ago, a 550-year-old seed sprouted
Since then, much older seeds have proved resilient. A seed of the South America herb achira (Canna sp.), taken from an ancient Indian necklace, has germinated, and the young plant is growing well.… Carbon-14 dating of bones at the site sets the seeds’ age at about 550 years.… The plant from the old seed appeared to have a disturbed gravity orientation, but is still growing fairly normally. — Science News, October 12, 1968. Scientists continue to test plants’ staying power, growing plants from older and older seeds. A roughly 1,300-year-old lotus seed (SN: 8/31/02, p. 132) and then a 2,000-year-old date palm seed (SN: 7/5/08, p. 13) broke the record for world’s oldest viable seeds. Then in 2012, Russian scientists grew a plant from tissue frozen in Siberian permafrost more than 30,000 years ago (SN: 4/7/12, p. 15). These successes give hope to seed bank programs that keep plant species in cold storage for future generations.
10-9-18 Nearly 2 million U.S. adult nonsmokers vape
A study highlights concerns that e-cigs, marketed as a way to stop smoking, may be addictive. Nearly 2 million U.S. adults who have never consistently smoked traditional cigarettes use e-cigarettes, according to results from a national survey. Of these sole e-cig users, about 60 percent are young adults, aged 18 to 24, researchers report online October 9 in Annals of Internal Medicine. E-cigarette companies have marketed the devices — which heat and vaporize liquids that typically contain nicotine — as a way to help adults quit smoking. But some public health officials worry that e-cigarettes could become a means to nicotine addiction, rather than an end. This concern is especially true for adolescents and young adults, whose developing brains are vulnerable to nicotine exposure, which can cause addiction and other harms (SN Online: 8/19/15). E-cigarettes also can pose a variety of other health risks (SN: 3/5/16, p. 16). Researchers analyzed 2016 data from the U.S. Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System. Among 261,541 nonsmokers, defined as having less than 100 cigarettes in a lifetime, 1.4 percent reported vaping. That corresponds to about 1.9 million sole e-cigarette users when extrapolated to the U.S. adult population in 2016. About 1.2 million of those users were young adults. The work “highlights the potential need to regulate sales and marketing of e-cigarettes to protect vulnerable populations, including young persons who have never smoked combustible cigarettes,” the researchers say. (Webmaster's comment: Nicotine is very, very addictive. That's why it's so hard to quit smoking! I stop smoking 18 years ago but I still want to.)
10-9-18 These light-loving bacteria may survive surprisingly deep underground
Some cyanobacteria may consume hydrogen to grow without sunlight. Deep below Earth's surface, life finds a way. Traces of cyanobacteria have been found more than 600 meters underground in a rocky outcrop in Spain, suggesting the microbes can survive without sunlight. Instead of photosynthesizing like others of their kind, these light-starved microorganisms may create energy using hydrogen, researchers report October 1 in the Proceedings of the National Academy of Sciences. Scientists initially were drilling for other types of bacteria deep below ground, says study coauthor Fernando Puente-Sánchez, a geomicrobiologist at the National Center for Biotechnology in Madrid. When the team discovered the cyanobacteria, it was “unexpected, counterintuitive,” he says. Cyanobacteria helped create the air we breathe today, first belching oxygen into the atmosphere over 3.2 billion years ago (SN Online: 9/8/15). Since the microbes’ metabolism typically depends on photosynthesis, they’re usually found where they have access to the sun’s rays. The researchers identified the cyanobacteria using a fluorescent dye that attaches to the microbes’ RNA. Because this fragile genetic material quickly degrades after the organism dies, scientists realized that the cyanobacteria must currently thrive in underground microbial communities despite the lack of sunlight. Puente-Sánchez and his team also ran tests to ensure their samples weren’t contaminated by drilling fluid, lab equipment or even microbes that live in and on the researchers themselves. (Webmaster's comment: Evolution is the most powerful force in the universe!)
10-9-18 Ancient ‘living fossil’ fish has scales that act as adaptable armour
The coelacanth fish has scales that can change their internal structure if they are pierced by a predator to stop cracks spreading. The coelacanth fish is a living fossil, its appearance little changed in hundreds of millions of years. A new analysis of its scaly armour may reveal how it has stuck around for so long. “Nature seems to generate combinations of properties that we have great difficulty with. I’m interested in how strong a material is and also how tough,” says Robert Ritchie at Lawrence Berkeley National Laboratory in California. “That combination is incompatible in synthetic materials, but nature does it with ease.” He and his colleagues examined scales from a coelacanth that had been preserved at the Scripps Institution of Oceanography for 45 years – they couldn’t use a sample from a living or recently deceased fish because coelacanths are endangered. When they CT scanned the scales, they found a surprisingly complex inner structure. On top is a tough mineral layer, and beneath there are bundles of collagen – the stuff that gives your skin its resilience – in a twisted structure similar to a spiral staircase. When pressure is applied to the scales, as it would be when a predator bites a coelacanth, the energy is absorbed by the collagen bundles. These bundles respond by untangling and rotating in order to withstand more pressure. “It’s like a smart material where the components of the structure are moving under load,” says Ritchie. The team also found that there are fibres between these bundles that play a role in stopping any cracks in the outer mineral layer from spreading. To see how they work, the team used a shark tooth attached to a mechanical arm to apply pressure to the coelacanth scale.
10-8-18 One-off genetic test could detect heart attack risk
People born at increased risk of heart attack could be identified by a one off-genetic test, a study has found. The Genomic Risk Score (GRS) test would only cost £40, cheap enough for population-wide screening, say the researchers. It could help to explain why people with apparently no conventional risk factors, such as high cholesterol, can still go on to have a heart attack. Experts say more work is needed to explore the screening idea. GRS can be measured at any age because people's DNA does not change, so, in theory, children could be tested. The test looks for patterns of risky genes rather than a single inherited gene. In the study, researchers looked at blood samples, but they say the test could be done with a simple mouth swab. They devised the GRS after analysing the genomic data from 500,000 people aged between 40 and 69, held in the UK Biobank, including 22,000 who had coronary heart disease. Lead author Dr Michael Inouye, of the Baker Heart and Diabetes Institute and University of Cambridge, said while roughly half of coronary heart disease (CHD) is down to genetics or is inherited, the other half is lifestyle or environmental. "We have been missing a genetic component in risk screenings... we've just been really in the dark about the genetic half." Participants with a GRS in the top 20% were more than four times more likely to develop coronary heart disease than those with scores in the bottom 20%. CHD is the leading cause of death worldwide and is responsible for more than 66,000 deaths in the UK each year.
10-8-18 How your brain is like a film editor
The hippocampus may slice our continuous existence into ‘scenes’ suitable for storing memories. The brain’s hippocampi may be the film editors of our lives, slicing our continuous experiences into discrete cuts that can be stored away as memories. That’s the idea raised by a new study that analyzed brain scan data from people watching films such as “Forrest Gump.” “Research like this helps us identify ‘What is an event, from the point of view of the brain?’ ” says memory psychologist Gabriel Radvansky of the University of Notre Dame in Indiana. Many laboratory tests of memory involve taking in discrete, dull lists of information. “So much research is done with these little bits and pieces — words, pictures, things like that,” Radvansky says. But those dry tidbits aren’t what the human brain usually handles. “The mind is built to deal with complex events.” As a closer approximation to real life, researchers used brain imaging data collected earlier as part of a larger project: While undergoing a functional MRI, 15 people watched “Forrest Gump,” and 253 people watched Alfred Hitchcock’s television drama “Bang! You’re Dead.” A separate group of 16 observers watched each of the productions and pressed buttons to indicate when they thought one event ended and another began. With the data in hand, cognitive neuroscientists Aya Ben-Yakov and Rik Henson, both of the University of Cambridge, aligned participants’ brain activity with the transition points marked by the 16 observers. A brain structure called the hippocampus, known to be important for memory and navigation, seemed particularly active at these junctures, the team reports October 8 in the Journal of Neuroscience. When the researchers looked at hippocampus behavior over the entire shows, the brain structure was most active when the observers had indicated a shift from one event to another.
10-8-18 Naysayers rise to the top because we naturally treat them as leaders
Openly negative and critical people are often elected leaders, perhaps because we perceive their disregard for social niceties as a sign of power and independence. Negative, critical people often ascend to positions of leadership because their disregard for social niceties makes them seem powerful, research suggests. Eileen Chou at the University of Virginia explored people’s attitudes towards “naysayers” – those who express negative, critical views, and “cheerleaders” – those who express positive, supportive views. Across 11 experiments, she found that naysayers were considered more powerful and suitable for leadership roles than cheerleaders. In one experiment, students were asked to read positive and negative restaurant reviews. They rated the author of the negative review as appearing more powerful, independent and able to express their real opinions about the restaurant. In another experiment, students were placed in groups and asked to review an artwork. Each group contained two actors, one with critical views and the other with appreciative views. The students rated the critical actor as appearing more dominant and in control, and were more likely to elect them as leader of their group. A third experiment asked online volunteers to read real quotes from past US presidential candidates. Without knowing who said them, the participants rated negative quotes like “these are very difficult times and challenges for America” as signalling greater power and leadership potential. Despite these leadership endorsements, the participants rated naysayers as being less likeable than cheerleaders. But this appeared to be offset by their respect for the naysayers’ courage to go against the grain.
10-8-18 Swallowing a vibrating capsule could help relieve constipation
Capsules that are programmed to vibrate when they reach the large intestine have been shown to stimulate bowel contractions and relieve chronic constipation. Blocked up? Capsules that vibrate in the gut can help encourage bowel motions, a clinical trial has found. Constipation is one of the most common gastrointestinal disorders, affecting up to 15 per cent of the population. The usual advice to eat fibre, exercise and take laxatives sometimes doesn’t work, leading to chronic pain and discomfort. To address this problem, Israeli company Vibrant has developed capsules that vibrate in the large intestine to stimulate contractions and move digestive products along. The capsules – which are the size of typical fish oil capsules – contain electronic mechanisms that can be programmed to vibrate at different frequencies. Satish Rao at Augusta University in the US and his colleagues recently tested the capsules in two clinical trials involving 245 people with chronic constipation. The participants were instructed to swallow five capsules per week for 8 weeks, taking each one before they went to bed at night. Half were given capsules that were programmed to vibrate when they reached the large intestine, and half were given identical non-vibrating placebos. The capsules were set to vibrate for one or two 2.5 hour periods during the 24 hours after they were ingested. They were usually excreted after 1 or 2 days. Participants who took the vibrating capsules had twice as many bowel movements per week as those in the placebo group. These tended to occur shortly after the vibration periods.
10-5-18 How should we control the power to genetically eliminate a species?
The power to re-engineer or eliminate wild species using a “gene drive” needs to be brought under international governance, say Simon Terry and Stephanie Howard. Thanks to a form of genetic engineering technology known as a gene drive, it is now possible to modify or even eliminate a wild species in its natural habitat, bypassing the laws of inheritance that have governed nature for millennia. The power to deliver “extinction to order” is potentially immense – as is the political challenge. The technology works by driving a gene throughout a population, meaning the plants or animals containing the drives could impact ecosystems that cross not just country borders, but entire continents. And so far, there is no such thing as a safe gene drive or a reliable way to rein one in after release. This potential for far-reaching effects has triggered a “constitutional moment”, a point when we are forced to confront fundamental questions. When is it acceptable to eliminate or re-engineer a wild species? Who decides and how? A number of authorative bodies, including the US National Academy of Sciences, have called for international governance of the technology. In a recent study, the Sustainability Council of New Zealand, where we work, suggested that countries proposing a gene-drive trial or release must first gain the consent of each country that could be affected, a process we call “collective consent”. This requirement is based on the principle at the core of the international biosafety protocol established through the United Nations. It says that countries importing living, genetically modified organisms have the right to prior, informed consent.
10-5-18 People in Chile are currently evolving the ability to digest goat milk
Most Europeans have a genetic mutation that allows adults to digest milk, but it is less common elsewhere. Now it is spreading through Chile, and we don't know why. A group of people living in Chile are evolving the ability to digest milk as adults, as most Europeans did thousands of years ago. The finding shows evolution is still changing us even now. It also questions our ideas about why milk digestion evolved. Nicolás Montalva of the Universidad Mayor in Santiago, Chile and his colleagues have studied the people living in Chile’s Coquimbo region, between the famously dry Atacama desert and country’s central valleys. It is dry so arable farming is hard. To survive, the people have become “agropastoralists”. In winter they grow food on small plots. But they also keep goats and make cheese from their milk, which they sell in summer. The people drink a lot of goat’s milk – which is surprising because native Americans cannot digest milk properly. Like all mammals, humans have an enzyme called lactase that breaks down the lactose sugar in milk. This enzyme normally gets turned off once a baby is weaned. But within the last 10,000 years some populations – particularly in northern Europe – have acquired mutations that keep the lactase active, allowing adults to digest milk. This is called lactase persistence. Many non-Europeans lack these mutations and suffer symptoms like diarrhoea and flatulence if they drink milk. Because the Americas were first settled over 15,000 years ago by Asian people, native Americans could not digest lactose.
10-4-18 City size and structure may influence influenza epidemics
New research could lead to more accurate predictions about flu seasons. A city itself influences the contours of its flu season – whether flu cases rise to a wintertime peak or plateau from fall to spring, new research suggests. Flu cases generally peak in winter in certain areas of the United States because the air is drier. That dryness helps the flu virus survive longer once sneezed out of a sick person, for example, allowing the virus to potentially infect more people. But after analyzing data on flu cases reported from 2002 to 2008 in 603 U.S. cities, researchers have found that a city’s size and structure also play a role in shaping local flu epidemics. Larger cities with higher levels of crowding were associated with a steady accumulation of cases throughout a flu season. Smaller cities with less crowding tended to have a flu season with a more intense surge in winter, researchers report in the Oct. 5 Science. “Understanding how the size and structure of cities impacts disease spread may help us to predict and control epidemics,” study coauthor and population biologist Benjamin Dalziel of Oregon State University in Corvallis, Ore., said October 2 at a news conference. As the United States enters into its next flu season, memories of the previous one, which was especially severe, remain freshly in mind (SN: 7/7/18, p. 16). The U.S. Centers for Disease Control and Prevention just announced that the 2017–18 season killed 80,000 people (SN Online: 9/27/18).
10-4-18 Anti-smoking ads traumatized me for life
Maybe we shouldn't be showing these terrifying ads to children. Like many people my age, I grew up on a diet of television that was definitely far scarier than I should have been watching at age, oh, 11. Are You Afraid of the Dark? Goosebumps. Courage the Cowardly Dog. But the most terrifying things on TV, by far, were the anti-smoking ads in between shows. Imagine the withered lungs of a smoker gasping on your television. Or what happens to blood when tobacco is inhaled. Or a more metaphorical horror — like a fish hook looped through a cheek, or a small demonic man yanking at a mouth. Whatever approach the ad took, it was bound to be deeply and weirdly and uniquely horrifying, and I could never jump to the remote to turn it off in time. There is ample evidence that scaring the daylight out of children and preteens (and adults) in this manner works. For one, I've never tried a cigarette. For another, the medical journal The Lancet discovered that a 2013 ad by the CDC might have ultimately caused some 100,000 Americans to give up smoking permanently. But setting aside the public good that comes from discouraging tobacco use, anti-smoking ads are all kinds of messed up. Sometime around 1997, when Rachael Leigh Cook famously destroyed a kitchen in the nightmare fodder that was "This is Your Brain on Drugs," a particularly effective aesthetic for public health announcements took off. Anti-smoking advertisements began to take cues from horror films, using unnatural or murky lighting, distorted sounds, and jarring or disgusting images to make a lasting impression, particularly on young viewers. Being one once myself, I can attest that whenever such an advert would come on after a cereal or Lego commercial, you couldn't help but stop, pay attention to the TV, and, disoriented, wonder, what is this…? (Webmaster's comment: Let's not expose our children to the ugly truth. Let a few of them die instead!)
10-4-18 Faecal swaps could help stop heart transplants from being rejected
Giving mice a faecal transplant made them more tolerant of a subsequent heart transplant, hinting the gut may be key to avoiding organ rejection. The key to organ transplants might lie in an unexpected place – the gut. Giving mice a faecal transplant made them more tolerant of a subsequent heart transplant. The explanation could be that bacteria in the bowel help regulate the immune system and stop it from launching an attack against the unfamiliar transplanted tissue. Finding the mechanism could lead to new medicines to stop organ rejection, says Jonathan Bromberg at the University of Maryland. “It’s a way to turn down the volume knob on the immune system.” Organ transplants are given to people who have failing organs such as their heart, kidney or liver. Recipients have to take powerful medicines to stop their immune systems from rejecting the organ, but even so, after several years the organ is often slightly scarred and inflamed, because of low-level immune attack. Previous work has suggested that people whose transplanted organs get rejected tend to have certain bacteria in their gut. But though bacteria causing the rejection is one explanation, so is the reverse – that rejection encourages growth of the bacteria. To find out which, Bromberg’s team gave some mice a transplant of bacteria-loaded faeces from pregnant animals, as the immune system is known to be naturally suppressed during pregnancy, so it doesn’t react against the fetus. Other groups got a faecal transplant from either non-pregnant mice, or ones with colitis, a disease where the gut is inflamed.
10-4-18 Tree rings reveal plague hit medieval Europe’s construction industry
Dating timber used to build European houses between AD 1250 and 1699 reveals that building activity fell during the Black Death and the Thirty Years’ War. Medieval plague and the Thirty Years’ War fought in 17th century Europe both had devastating effects on building and development on the continent. That’s the conclusion of a massive new analysis of the timber used in historical European buildings, dated using tree ring methods. Wood from archaeological sites is routinely collected, analysed and dated using dendrochronology, or tree-ring dating. Researchers scoured through earlier studies to compile data on nearly 50,000 such pieces of wood used for constructing buildings from 1250 to 1699. All of the wood came from Central and Western Europe, mostly the German and French speaking parts of the former Holy Roman Empire. Compiling the dates of all this wood allowed the researchers to establish a broader history of development over the 450-year period and compare it to the record of major historical events during that time. “The felling dates are basically a new and not hitherto used historical source material for studying demographic, social and economic history,” says Fredrik Charpentier Ljungqvist, an historian from Stockholm University in Sweden, adding that this method can also fill in some of the gaps during periods when written evidence is limited. The tree ring dates show building activity dropped off sharply during a period known as the Late Medieval Crisis in the 14th and 15th centuries, and again during the Thirty Years’ War that was fought between 1618 and 1648.
10-3-18 Speeding up evolution to create useful proteins wins the chemistry Nobel
A trio of researchers pioneered techniques that led to useful drugs and biofuels. Techniques that put natural evolution on fast-forward to build new proteins in the lab have earned three scientists this year’s Nobel Prize in chemistry. Frances Arnold of Caltech won for her method of creating customized enzymes for biofuels, environmentally friendly detergents and other products. She becomes the fifth woman to win the Nobel Prize in chemistry since it was first awarded in 1901. Gregory Winter of the University of Cambridge and George Smith of the University of Missouri in Columbia were recognized for their development and use of a technique called phage display. This molecule-manufacturing process can generate biomolecules for new drugs. The trio will share the 9-million-Swedish-kronor prize (about $1 million), with Arnold getting half and Winter and Smith splitting the other half. “Wow, well-deserved!” says Paul Dalby, a biochemical engineer at University College London. “Protein engineering as a field is absolutely founded upon their work.” In the 1990s, Arnold wanted to make an enzyme that would break down a milk protein called casein in an organic liquid, rather than in water. Instead of trying to manually sculpt the chemical building blocks of that enzyme, subtilisin E, to give it the right properties, she opted for a more hands-off approach.
10-3-18 A 90,000-year-old bone knife hints special tools appeared early in Africa
Archaeologists found the implement in a coastal cave in Morocco. Africa’s Stone Age was also a Bone Age. Ancient Africans took bone tools to a new level around 90,000 years ago by making pointed knives out of animals’ ribs, scientists say. Before then, bone tools served as simpler, general-purpose cutting devices. Members of northern Africa’s Aterian culture, which originated roughly 145,000 years ago, started crafting sharp-tipped bone knives as fish and other seafood increasingly became dietary staples, researchers suggest online October 3 in PLOS ONE. The new find supports the view that strategic planning for survival and associated changes in toolmaking emerged much earlier in human evolution than has traditionally been assumed. Excavations inside Dar es-Soltan 1 cave, near Morocco’s Atlantic coast, uncovered the bone knife in 2012, says a team led by geoarchaeologist Abdeljalil Bouzouggar of the National Institute of Archaeological and Heritage Sciences in Rabat, Morocco, and biological anthropologist Silvia Bello of the Natural History Museum in London. The knife’s base and its broken-off tip were embedded in sediment that dates to about 90,000 years ago.
10-3-18 Chemistry Nobel Prize awarded for harnessing evolution to help humans
he chemistry Nobel Prize goes to Frances Arnold, George Smith, and Gregory Winter for controlling evolution to create proteins that solve chemical problems. The Nobel Prize in chemistry has been awarded to three scientists who have harnessed the power of evolution to develop biological molecules with useful applications. Frances Arnold, based at the California Institute of Technology in the US, developed a way to direct the evolution of enzymes to make them much more effective at catalysing chemical reactions. Her work has found applications in brain imaging, biofuels, pharmaceuticals and the chemical industry. She has been awarded half of the prize money, and is the fifth woman to win a chemistry Nobel. The other half is split between George Smith at the University of Missouri and Gregory Winter at the MRC Laboratory of Molecular Biology, UK. This pair developed ways to develop therapeutic antibodies, which are now used to treat autoimmune diseases, anthrax and cancer. “This has formed the basis for a pharmaceutical revolution,” said Nobel committee member Sara Snogerup Linse while announcing the prize. All three have applied the principles of Darwin in test tubes, said committee chair Claes Gustafsson. Their work is an extension of selective breeding, which has been practised by humans for millennia. Enzymes are proteins made in cells which catalyse chemical reactions, making them work much faster. They have evolved over millions of years, but in 1993, Arnold worked out that you could direct their evolution and make the process happen much faster.
10-3-18 Speeding up the evolution of proteins wins the chemistry Nobel
The work of the three new laureates is used in everything from drugs to biofuels. Frances Arnold of Caltech, George Smith of the University of Missouri in Columbia and Gregory Winter of the University of Cambridge have won the Nobel Prize in chemistry for speeding up evolution to make proteins with new and useful properties. Such proteins are suitable for a variety of uses, ranging from new drugs to biofuels. The new laureates were announced October 3 at the Royal Swedish Academy of Sciences in Stockholm. Thanks to Arnold’s work on evolving new enzymes from old ones in a test tube, “you can now use enzymes to speed up any process you want,” Nobel committee member Sara Snogerup Linse said during the announcement ceremony. Instead of test tubes, Smith and Winter used viruses called bacteriophages. The researchers put instructions for building proteins into the viruses, commonly called phage, and let the phage mutate to make new versions of the proteins. Those proteins are then incorporated into the outer capsule of the phage, earning the name phage display. Winter’s research, in particular, produces human antibodies for treating a variety of diseases. Antibodies made from bacteriophages can bind more efficiently to their targets than even ones produced during immunization, allowing doctors to give lower doses, Snogerup Linse said. The trio will share the 9-million-kronor prize (about $1 million). Arnold, who is the fifth woman to win the chemistry prize, will claim half of it for her work. Smith and Winter will split the other half. The laureates will collect a medal and their shares of the monetary prize at a ceremony in Stockholm in December.
10-3-18 Idly tapping your fingers can make you think time has slowed down
Moving a body part in time to a rhythm alters your perception of time, causing it to either stretch or contract – providing new clues about which parts of the brain control our body clocks. When you move your body in time to a rhythm, your perception of time stretches and contracts. The finding might help us pin down which parts of the brain control our internal clocks. “Distortions of perceived time are coupled to the timing of your actions, which are dictated by an internal rhythm,” says Alice Tomassini at the Italian Institute of Technology in Ferrara. She and her colleagues asked 16 participants to listen to four rhythmical beats, each one second apart, and then tap out four additional beats with their finger to keep the rhythm going. The participants were seated in a dark room at a desk on which there was a yellow LED light. Before the tapping test, the participants were taught to familiarise themselves with the way the yellow light would occasionally flash twice, with a 150-millisecond gap between the two flashes. During the test, the yellow light flashed twice after a participant’s third finger tap but before the fourth. The gap between flashes varied from between 70 and 300 milliseconds, and participants were then asked to judge each time whether the gap between the flashes was longer or shorter than the 150 millisecond interval they had become familiar with. There was an additional factor at play: sometimes the yellow light flashed twice just after a participant had made their third finger tap, sometimes just as they were preparing to make their fourth finger tap, and sometimes roughly halfway through the time interval between the two finger taps.
10-3-18 T. rex evolved into a monster predator by dumbing down its brain
The very first tyrannosaurs were relatively small dinosaurs – and the skull of one of them seems to have contained a brain with a more complex shape than that of the enormous T. rex. Tyrannosaurus rex has a reputation for being one of the biggest and fiercest dinosaurs ever to have lived. But it probably wasn’t the brightest: it had a simpler brain than an earlier, smaller tyrannosaur. The change could be a consequence of growing so large. Fossils suggest that T. rex could reach 12 metres in length and between 8 and 14 tonnes in weight. It belonged to a family of dinosaurs called the tyrannosaurs – but not all of them were large. For example, Dilong paradoxus – which lived 50 million years before T. rex evolved – was only 1.6 metres long and about knee-high to a human. Martin Kundrát at Pavol Jozef Safarik University in Slovakia, and his colleagues, want to know what happened to tyrannosaur brains as the dinosaurs evolved from small predators to beasts the size of T. rex. In their search for clues they looked inside the skull of a 125-million-year-old Dilong fossil found in Liaoning, northern China to work out the size and shape of its brain. Then they did the same for a 67-million-year-old T. rex fossil – a famous specimen nicknamed ‘Sue’. The team found a shift in brain shape as tyrannosaurs evolved and enlarged — from an S-shaped arrangement in Dilong to what Kundrát describes as a “simpler”, more linear shape in T. rex.
10-2-18 Nobody can agree about antidepressants. Here’s what you need to know
For some they are lifesavers, for others ineffective and even addictive. Our special report looks at why even experts disagree on what good antidepressants do. “IT WAS a year of very bad things,” says Suzy Barber, who lives in London. In 2006, her brother took his own life and a close friend died from cancer. Barber lost her job as a journalist and her freelance work gradually dwindled. With not enough to occupy her, she dwelt on tiny problems. “Everything seemed so monumental,” she says. Barber became mired in despair and self-loathing. “You can’t motivate yourself to do anything, so you’re unproductive. That manifests in you hating yourself more. You feel like you’re constantly teetering on the edge of a massive drop.” Eventually, Barber accepted her doctor’s advice and started on antidepressants. Within six weeks, she was on the road to recovery. Counselling helped, but “the pills kicked in”, she says. “Maybe they saved my life.” Global antidepressant use is soaring. Stories such as Barber’s make a compelling case that the drugs can be helpful. Yet it seems barely a month goes by without them being dismissed in the media as “happy pills” that get people “hooked” or turn them into zombies. Experts, meanwhile, disagree over whether the drugs genuinely have the biochemical effects claimed for them and debate rages about side effects, withdrawal symptoms and the possibility of addiction. So what should we believe – and who, if anyone, should be taking these pills? Depression is often seen as a modern malaise, but it has always been with us, just under different names: melancholia, nervous breakdown or sometimes just “nerves”.
10-1-18 Discovery of how to prod a patient’s immune system to fight cancer wins a Nobel
Two scientists share the prize for identifying proteins that act as brakes on tumor-fighting T cells. Stopping cancer by removing brakes on the immune system has earned James P. Allison of the University of Texas MD Anderson Cancer Center in Houston and Tasuku Honjo of Kyoto University in Japan the Nobel Prize in physiology or medicine. “Allison’s and Honjo’s discoveries have added a new pillar in cancer therapy,” Nobel committee member Klas Kärre said in an Oct. 1 news conference announcing the prize. “It’s a new principle.” Other therapies, such as surgery, radiation and chemotherapy, target tumor cells themselves. The two laureates’ strategy was to persuade the patient’s own immune system to go after the cancer (SN: 7/11/15, p. 14). “The seminal discoveries by the two laureates constitutes a paradigmatic shift and a landmark in the fight against cancer,” Kärre said. The newly minted laureates will equally share the prize of 9 million kronor, equivalent to just over $1 million. Both men have made substantial contributions to basic research in immunology beyond their work in cancer, says Norman “Ned” Sharpless, director of the National Cancer Institute in Bethesda, Md. The Nobel Assembly at the Karolinska Institute in Stockholm chose to honor the men’s achievement in cancer immunotherapy, but they “also deserve lifetime achievement awards for their contributions to science,” Sharpless says.
10-1-18 Gene editing can speed up plant domestication
The CRISPR technique quickly tamed ‘unruly’ ground cherries. Gene editing can speed up plant domestication, taming wild vines, bushes and grasses and turning them into new crops. Editing just two genes in ground cherries (Physalis pruinosa) produced plants that yielded more and bigger fruit, researchers report October 1 in Nature Plants. Those edits mimic changes that occurred in tomato plants during domestication, bringing the sweet tomato relative a step closer toward becoming a major berry crop, says study coauthor Zachary Lippman, a plant biologist at Cold Spring Harbor Laboratory in New York. Ground cherries and their close relatives Cape gooseberries or golden berries (Physalis peruviana L.) are grown in many parts of the world, but have traits — such as dropping their fruit on the ground — that make them unattractive for large-scale agriculture. “This is a really unruly plant with great potential,” says Harry Klee, a plant geneticist at the University of Florida in Gainesville. The new work serves as a how-to manual for others interested in rapidly domesticating new crops, he says.
10-1-18 Cancer immune therapy recognised with Nobel Prize for medicine
The Nobel Prize in physiology or medicine has been awarded to James Allison and Tasuku Honjo for discovering how cancer can be treated by targeting the immune system. The Nobel Prize in physiology or medicine has been awarded to scientists who discovered how cancer can be treated by targeting the immune system. Cancer cells feature mutations that mean they can be recognised by our immune systems as foreign. But immune reactions against cancer are usually very weak. James Allison and Tasuku Honjo, working separately, discovered proteins that act as a brake on the immune system. They later found that that releasing these brakes would allow the immune system to attack cancer cells. Many drugs known as checkpoint inhibitors have since been developed based on this principle. Immunotherapy is seen as one of the most promising frontiers in cancer research. Honjo was inspired to work on cancer as a trainee doctor in the 1960s when a classmate died from gastric cancer. “My dream became to cure cancer,” he told New Scientist in 2016. Honjo discovered the protein PD-1 in 1992, and found that disabling it made the immune system become hyperactive in mice. “The immune system needs brakes and accelerators, and PD-1 was clearly a brake,” he said. Later, he found that cancer cells often produce another protein that interacts with PD-1. This interaction allows cancer cells to suppress the immune reaction against themselves. But if mice were engineered to lack PD-1, tumours wouldn’t grow. Honjo initially had enormous difficulty convincing the pharmaceutical industry to follow up on his findings. Now, PD-1 inhibitors such as nivolumab and pembrolizumab have been found to shrink tumours far more effectively than chemo- and radiotherapy with much milder side effects.
10-1-18 Cancer immunotherapy wins the 2018 medicine Nobel Prize
Two researchers are honored for therapies that unleash immune systems brakes against cancer. James P. Allison of MD Anderson Cancer Center in Houston and Tasuku Honjo of Kyoto University in Japan have won the Nobel Prize in physiology or medicine for advances in harnessing the immune system to fight cancer. All previous types of cancer therapy were directed at the tumor cell, but Allison’s and Honjo’s approach was to remove brakes that keep the immune system in check, unleashing it against tumor cells. These “checkpoint inhibitor” therapies have greatly increased survival of cancer patients and may produce even greater results when combined with traditional therapies. The researchers will equally share the prize of 9 million kronor, equivalent to just over $1 million.
10-1-18 Smuggling a CRISPR gene editor into staph bacteria can kill the pathogen
The technique takes advantage of the way the microbes naturally swap genes to become more harmful. Bits of DNA that make bacteria dangerous can be co-opted to bring the microbes down instead. Stretches of DNA called pathogenicity islands can jump between bacteria strains, introducing new toxin-producing genes that usually make a strain more harmful. Scientists have now modified pathogenicity islands by replacing the toxin-producing genes with genes that, in mice, disabled or killed Staphylococcus aureus bacteria. If the approach works for humans, it could offer an alternative to traditional antibiotics that could one day be used against deadly drug-resistant Staphylococcus strains, researchers report September 24 in Nature Biotechnology. Pathogenicity islands are already primed for such inside jobs: The stretches of DNA naturally get bundled into small parcels that can easily enter bacteria to deliver new genes. Researchers turned those parcels into Trojan horses of sorts, replacing the toxin-producing genes with sequences of the gene-editing tool CRISPR/Cas9, which snips DNA in specific places. In one version, the Cas9 cuts the staph DNA, killing the bacteria. In another, a modified version of CRISPR/Cas9 doesn’t make any cuts; instead, the Cas9 latches onto a gene that controls how dangerous staph bacteria are to make them less effective at causing infection.
10-1-18 Fluke experiment hints deep brain stimulation really treats depression
People with depression treated with deep brain stimulation suffered unexpected relapses when the batteries went flat, hinting the treatment isn’t just a placebo. It was an unwelcome shock for four people in Germany, when they suddenly had depression relapses. The condition had been kept at bay for four years by deep brain stimulation (DBS), a form of therapy whereby parts of their brains continuously receive electrical stimulation from deeply implanted electrodes. All four experienced sudden and unexpected relapses, but recovered within around 12 hours when it was discovered that the batteries operating their implants had gone flat. The results counter suspicions that the benefits for DBS for depression are simply placebo effects. One other person — who had been using DBS for two and a half years — also relapsed after deciding he didn’t need it anymore and deliberately switched the system off. He rapidly recovered after reactivating it. “These cases deliver a very strong message against it being a placebo effect,” says Thomas Schlaepfer, who has treated these and several other people at the Freiburg University Medical Center in Germany. Although DBS has been used widely and with great success to treat thousands of people with Parkinson’s disease, doubts have surfaced about its effectiveness for severe depression. Two trials in 2015 delivered disappointing results, for example. “There has been a large stigma to using DBS for depression, that it is largely a placebo effect,” says Albert Fenoy, who also treats depression with DBS at the University of Texas in Houston. “Showing a quick relapse to depression after turning off the stimulation that previously improved their mood is great proof this is not due to a placebo effect.”
10-1-18 Domesticating tomatoes took millennia – we can now redo it in 3 years
With CRISPR gene editing technology we can now rapidly domesticate wild plants to create tasty and healthy food. It took at least 3000 years to domesticate the tomato. Now two separate teams in Brazil and China have done it all over again in less than three years – only better in some ways, as the redomesticated tomatoes are more nutritious than the ones we eat now. This approach, which relies on the revolutionary CRISPR genome editing technique, could not only improve existing crops, it could also be used to turn thousands of wild plants into far more useful and appealing crops. In fact, a third team in the US has already begun to do this with a relative of the tomato called the groundcherry. This fast-track domestication could help make the world’s food supply healthier and far more resilient to climate change and diseases, such as the rust fungus devastating wheat crops. “This could transform what we eat,” says Jorg Kudla at the University of Munster in Germany, a member of the Brazilian team. “There are 50,000 edible plants in the world, but 90 per cent of our energy comes from just 15 crops.” “We can now mimic the known domestication course of major crops like rice, maize, sorghum or others,” says Caixia Gao of the Chinese Academy of Sciences in Beijing. “Then we might try to domesticate plants that never been domesticated.” Wild tomatoes, which are native to the Andes region in South America, produce pea-sized fruits. Over many generations, peoples such as the Aztecs and Incans transformed the plant by picking mutants with desirable traits such as larger fruit.