97 Evolution News Articles
for September 2018
Click on the links below to get the full story from its source
9-30-18 Why are so many parents afraid of having a kid with Down syndrome?
The stigma against the condition is far more dangerous than the disorder itself. son Aaron, aged nine, has Down syndrome. If you look at photos of our family, his disability might not be readily apparent. He wears glasses, and he likes to pull his baseball cap down low over his forehead, which makes the characteristic almond shape of his eyes difficult to see. At first glance, Aaron might look like any other nine-year-old — and that seems fitting because much of his life revolves around the activities of a typical boy his age: sports, playing with pets, going to school, watching cartoons. As a parent of a child with Down syndrome, I was alarmed when I first heard about the high rates of abortion of fetuses prenatally diagnosed with the condition in the U.S. These rates range from 67 percent to 90 percent and above. But after a bit of reflection, this reaction of alarm might not make a lot of sense. Though my wife and I chose to bring Aaron into our family after his prenatal diagnosis, some might think that the opposite choice made by others would not affect Aaron or our family. Why should someone like me care about whether others choose to abort a fetus with Down syndrome? Isn't it just a personal decision? I haven't been able to shake my sense of alarm, but now I understand it better. My worry about the choices of other prospective parents is a protective impulse. What are the motivations behind the choice to abort, I wonder. There is reason to believe that these choices are often influenced by bias against people with Down syndrome. And if people are biased against those with Down syndrome, then such attitudes directly threaten the wellbeing of my son.
9-28-18 The dangers of a daily aspirin
In a study that upends decades of medical advice, Australian scientists have found that taking an aspirin a day does not reduce older people’s risk of heart disease or cancer—and in fact can cause them serious harm. For four and a half years, researchers observed more than 19,000 adults in Australia and the U.S. with no history of heart disease, stroke, or dementia and with a median age of 74, reports ABCNews.com. Half were given 100 mg of aspirin a day, while the other half received a placebo. At the end of the study, those who had been taking the drug were just as likely to suffer from heart disease and stroke—and faced a higher risk of dangerous internal bleeding in the stomach, brain, and elsewhere. The aspirin-takers actually had slightly higher rates of mortality over that period, in large part because of deaths from cancer—though researchers cautioned that further study was needed to assess any possible link between aspirin and cancer. They also emphasized that their results didn’t counter previous findings that aspirin is beneficial for those who have already suffered from heart disease or stroke. “Millions of healthy older people around the world who are taking low-dose aspirin without a medical reason may be doing so unnecessarily,” says lead author John McNeil, from Monash University in Melbourne. “These findings will help inform prescribing doctors.”
9-28-18 Time to ban infant walkers?
So many young children are injured while using infant walkers that these products should be banned in the U.S., say the authors of a new study. Researchers found that between 1990 and 2014, more than 230,000 children under the age of 15 months were treated in emergency rooms for injuries related to walkers, an average of 9,000 a year. Almost three-quarters of the incidents, reports CBSNews.com, were caused by children in walkers falling downstairs; other injuries occurred because the walker gave a child access to something that otherwise would have been out of reach, such as a hot appliance. More than 90 percent of the accidents led to head or neck injuries. Improvements in safety standards have helped: The number of injuries fell nearly 23 percent in the four years after federally mandated safety rules were introduced in 2010; in 2014, about 2,000 children were injured by the devices. The American Academy of Pediatrics has long called for walkers to be banned in the U.S., as they are in Canada. “There are no advantages to using walkers,” says senior author Gary Smith, of the Nationwide Children’s Hospital in Columbus, Ohio. “Parents should be told not to use them.”
9-28-18 Disinfectants and obesity
Surface cleaners and other household disinfectants could be making children overweight by altering the bacteria in their gut. Researchers in Canada found that infants who lived in households where antimicrobial disinfectants were used every week were twice as likely—at ages 3 to 4 months—to have higher levels of lachnospiraceae gut bacteria, which are very efficient at breaking down food and help the human body extract more energy. By age 3, those children were more likely to be overweight or obese than kids whose households hadn’t used disinfectants as regularly. High levels of lachnospiraceae have been linked in animal studies to increased levels of body fat and insulin resistance. The study also found that children living in households that used eco-friendly cleaning products were less likely to be overweight, though that may have been because those kids had healthier lifestyles and diets overall. Senior researcher Anita Kozyrskyj says further research is needed, but urges people to “take it easy” when cleaning with disinfectants. “Our observations were at the high end [of cleanliness],” she tells USA Today, “with people who were cleaning more than weekly, up to daily.”
9-28-18 Curbing drinking with ridicule
The best way to persuade middle-aged people to cut down on their drinking isn’t to warn them about the health implications—it’s to tell them they’re embarrassing themselves. That’s the conclusion of a new study that looked at responses about alcohol consumption from 13 previous scientific papers, reports CNN.com. The impact of alcohol on health was described as “a minor concern or not considered at all” by people ages 30 to 65 who were included in those papers. Most of them felt that their drinking wasn’t a problem so long as they could still meet their day-to-day responsibilities, and that their behavior remained socially acceptable. For them, signs that they had overdone it included slurred speech, vomiting, and an unsteady gait. “We knew very little about the decision-making processes that go into the alcohol consumption of middle-age drinkers,” says lead researcher Emma Muhlack. The results from this review, she adds, may help health authorities create more effective anti-drinking ad campaigns.
9-28-18 Five million Americans living with Alzheimer’s disease
Five million Americans were living with Alzheimer’s disease and related dementias in 2014, representing about 1.6 percent of the U.S. population. That number is projected to grow to 13.9 million, nearly 3.3 percent of the population, by 2060.
9-28-18 A furry ice-age wolf pup
Canada’s Klondike region, famed for its gold, now has two other treasures to boast about: the stunningly preserved remains of an ice-age wolf pup and caribou calf. The animals—whose skin, fur, and muscle tissue are completely intact—were unearthed from the melting permafrost by gold miners two years ago, and were unveiled by scientists last week. The wolf pup’s body is complete; the caribou calf is missing its hind legs and tail. They have been radiocarbon-dated to 50,000 years old—the limit for that type of age analysis. But they are likely much older: The bodies were found at the site of an 80,000-year-old ash bed. Thought to be some of the oldest mammal tissue in the world, they are so well preserved that it should be possible to determine the animals’ diet, health, age, genetics, and cause of death. “We’re so used to just working with bone,” Grant Zazula, a paleontologist who joined the excavation, tells LiveScience.com. “To have animals with flesh and skin and hair, it really brings the ancient world to life.”
9-28-18 Does more than 2 hours of screen time really harm children’s brains?
A study says that children do better academically if they limit screen time, but that doesn’t necessarily mean it is time to ban their phones. It seems intuitive that children’s schoolwork will dip if they spend too much time gazing at their phones instead of getting to bed on time or getting some exercise. And that’s broadly what a Canadian study published this week has found. But is it the final word, and should parents be panicked into pulling the plug on their kids? Researchers in Canada analysed lifestyle data from questionnaires taken by 4520 American children aged 8 to 11. The children also performed a variety of standard cognition tests. Jeremy Walsh of the Children’s Hospital of Eastern Ontario Research Institute in Ottowa, Canada and his colleagues evaluated how well the children met various Canadian government guidelines. These suggest limiting screen time to 2 hours a day, sleeping for 9 to 11 hours a night and spending at least an hour being physically active. More than a third, 1655 children, met the guideline for limiting screen time, and their average performance in the cognitive tests was 4.5 per cent higher than that of the 1330 children who met none of the guidelines. The gain was even higher, at 5.15 per cent, for those meeting both the screen-time and sleep recommendations. So, armed with these new results, should parents be clamping down on screen use? Walsh himself says the results are provisional. “All these results need to be tempered by the fact it was only a snapshot of children at one point in time,” he says. The US study is running for a further 10 years, and so will enable Walsh and others to track whether the children change their behaviour over time.
9-28-18 Every man in Spain was wiped out 4500 years ago by hostile invaders
When a new group of people arrived on the Iberian peninsula 4500 years ago, local males stopped passing on their genes – suggesting they were supplanted or killed. A genetic analysis has revealed that, about 4500 years ago, part of southern Europe was conquered from the east. In what is now Spain and Portugal, the local male line vanished almost overnight, and males from outside became the only ones to leave descendants. David Reich of Harvard Medical School in Boston, Massachusetts presented the results on Saturday at New Scientist Live in London, UK. Reich and his colleagues have spent the last few years reading the DNA of people who lived in Europe and Asia several thousand years ago, to track past migrations. Archaeology had already revealed that modern humans first entered Europe about 45,000 years ago – at which point the Neanderthals that had been living there for tens of thousands of years vanished. The first modern humans in Europe were hunter-gatherers. About 9000 years ago a second wave of modern humans arrived from the region around modern Israel and Jordan. These were farmers and at first they lived alongside the hunter-gatherers, with the two cultures remaining separate. Hunter-gatherers could simply move to a new area if a disagreement with a neighbouring group arose. But because the farmers settled down in specific places and invested time and effort in the land, disputes could escalate. By 7000 years ago there is evidence of massacres. Then beginning around 5000 years ago another group of people entered Europe. It’s this group that Reich’s team focused on.
9-27-18 The CDC says 80,000 people died from the flu last year
That makes the 2017–2018 flu season one of the deadliest in the United States. In the past year, the flu killed an estimated 80,000 Americans — the country’s highest death toll from flu and related complications in more than a decade, according to the U.S. Centers for Disease Control and Prevention. The 2017–2018 flu season has been classified as one of “high severity” (SN: 7/7/18, p. 16), with some 900,000 people hospitalized with flu symptoms — the highest hospitalization rate since the 2005–2006 season. A record 180 children died, as of August. Only the 2009 flu pandemic had more child deaths, with 358. The high total death toll was “not surprising,” CDC spokesperson Kristen Nordlund says, given that the main virus circulating “was influenza A H3N2, and we know that virus tends to be severe for young children and the elderly.” U.S. health officials are now gearing up for a new flu season. “It is not possible to predict what this flu season will be like,” Nordlund says.
9-27-18 In China, a deadly strain of bird flu now easily infects ducks
A vaccine that protects chickens from the virus works in ducks, too. Some ducks in China now carry a deadly strain of bird flu. Highly pathogenic versions of H7N9 — a bird flu strain that’s proven particularly deadly to people — and H7N2 viruses have turned up in ducks in the Fujian province. These viruses replicate easily in the ducks and can kill them, researchers report September 27 in Cell Host & Microbe. The discovery is worrisome because the virus made the jump to ducks just ahead of efforts to eliminate H7N9 by vaccinating chickens. Since H7N9 began sickening people in 2013, a total of 1,625 people have contracted the bird flu strain and 623 have died. Most of those infected had been in contact with chickens (SN Online: 3/11/15). Initially the virus killed about a third of people who caught it. But in 2016, the virus mutated to become even deadlier in both poultry and people, killing about half of people it infected. A vaccine against the virus protects chickens, and consequently people, the new study found. No human cases of H7N9 have been reported since October 2017. But ducks weren’t vaccinated because the original H7N9 virus didn’t infect them easily. Now, they should be to prevent the deadlier virus strains from spreading to other poultry, wild birds and to people, the researchers write.
9-27-18 Laser mapping shows the surprising complexity of the Maya civilization
Ancient Guatemalan cities were larger and more interconnected than thought. A laser-shooting eye in the sky has revealed the previously unappreciated size and complexity of ancient Maya civilization, both before and during its presumed heyday, scientists say. Maya people in what’s now northern Guatemala built surprisingly extensive defensive structures and roads as part of political systems featuring interconnected cities, starting at least several hundred years before the rise of Classic Maya society, an international team reports in the Sept. 28 Science. Classic Maya sites date to between around 250 and 900. Aerial laser maps of northern Guatemala obtained in 2016 and map-guided ground surveys and excavations in 2017 compel a reevaluation of traditional assumptions about the ancient Maya, the team concludes. A long-standing idea that Classic Maya civilization, which covered parts of southern Mexico and much of Central America, once contained relatively small city-states ruled by warring kings has drawn increasing skepticism over the last decade (SN Online: 4/17/18). Laser technology shot down that scenario by gazing through forests and vegetation at 10 Maya sites — as well as in two areas with signs of Maya-era activity but no named sites — dating from a couple hundred years before the start of the Classic period to near its end. “Every Maya city was bigger and more populated than we previously thought,” says archaeologist Francisco Estrada-Belli of Tulane University in New Orleans. Estrada-Belli led the investigation along with archaeologists Marcello Canuto, also at Tulane, and Thomas Garrison of Ithaca College in New York.
9-27-18 Monkeypox has reached the UK – here’s what you need to know
Three people in the UK have caught the tropical disease, a relative of smallpox, the first time there have been cases in this country. But the smallpox vaccine provides immunity. I’ve heard of Ebola and Zika, but what is monkeypox? Monkeypox is caused by a virus that is a relative of smallpox. It causes fever, headaches, and a rash that turns into blisters like those of chickenpox. It is usually just a mild illness lasting a few weeks, but can sometimes be deadly. As the name suggests, it was first identified in monkeys, and is mainly confined to West and Central Africa. How serious is the disease there? In Africa, there are occasional reports of people catching it from eating bushmeat such as squirrels and rodents, and it can sometimes pass between humans too. It has a reported death rate of between 1 and 10 per cent, with children being most likely to die. Why is it in the news? Three people in the UK have been diagnosed with monkeypox since the start of September, and are now being cared for in hospital by tropical disease specialists. The condition has not been recorded in this country before. How worried should I be? Don’t panic. The disease does not pass very easily between people. Transmission between humans occurs through contact with bodily fluids or getting close enough to breathe in large airborne droplets. It is not surprising that a healthcare worker got infected, but such droplets generally cannot travel more than a metre or so, according to the US Centers for Disease Control and Prevention, so there’s little risk to the public.
9-26-18 Survey raises worries about how screen time affects kids’ brains
U.S. kids, ages 8 to 11, averaged 3.6 hours a day playing on their digital devices. Nearly two out of three U.S. kids spend more than two hours a day looking at screens, a new analysis of activity levels finds. And those children perform worse on memory, language and thinking tests than kids who spend less time in front of a device, the study of over 4,500 8- to 11-year-olds shows. The finding, published online September 26 in Lancet Child & Adolescent Health, bolsters concerns that heavy use of smartphones, tablets or televisions can hurt growing minds. But because the study captures a single snapshot in time, it’s still not known whether too much screen time can actually harm brain development, experts caution. Researchers used data gleaned from child and parent surveys on daily screen time, exercise and sleep, collected as part of a larger effort called the Adolescent Brain Cognitive Development Study. Cognitive abilities were also tested in that bigger study. As a benchmark for the new study, the researchers used expert guidelines set in 2016 that recommend no more than two hours of recreational screen time a day, an hour of exercise and between nine and 11 hours of nighttime sleep. Overall, the results are concerning, says study coauthor Jeremy Walsh, an exercise physiologist who at the time of the study was at the Children’s Hospital of Eastern Ontario Research Institute in Ottawa, Canada. Only 5 percent of the children met all three guidelines on screen time, exercise and sleep, the survey revealed. Twenty-nine percent of the children didn’t meet any of the guidelines, meaning that “they’re getting less than nine hours of sleep, they’re on their screens for longer than two hours and they’re not being physically active,” Walsh says. “This raises a flag.”
9-26-18 Paralysis need not mean paralysis for life
Despite prevailing medical wisdom saying it shouldn't work, implants have allowed paralysed people to walk again. We need to pin down the science to help others. SOME might call it a miracle, but it relies on technology. At two separate clinics, three people paralysed from the waist down have walked again, thanks to an electrical stimulation implant, combined with intensive exercise and rehabilitation (see “Three people with paralysis can walk again with nerve-boosting implant”). Yet it is true that prevailing medical wisdom says this should be impossible. Because these people’s injuries had ruptured the spinal cord, contact between the brain and the nerves operating the leg muscles was thought to be entirely severed. Controversially, the researchers who restored mobility believe that some weak connections survived. By tuning the electrical device, they say it was possible to reinforce those weak signals to the point where the leg muscles began to respond again to signals from the brain. The resulting steps are halting and awkward. But they are steps, and with them comes hope that other people can benefit. Paralysis perhaps need not mean paralysis for life. If we can pin down the science, and work out how to identify similarly surviving spinal connections – a challenge in itself – we might help many more people with similar life-changing injuries.
9-26-18 Fat and proud: Why body-positive activists say obesity can be healthy
Growing calls for "fat acceptance" fly in the face of accepted medical advice, but studies show you can be overweight and healthy. WOMEN’S glossy magazines often get flak for promoting unhealthy beauty ideals, but usually it is because their models are so thin. Not so for this month’s UK issue of Cosmopolitan, which features the plus-sized model Tess Holliday resplendent in green satin underwear. Holliday’s success in modelling, despite her UK size-26 figure, epitomises the burgeoning “body-positive” movement, which says that people’s weight is their own business and that no one should dislike the way they look. “If I saw a body like mine on this magazine when I was a young girl, it would have changed my life,” Holliday said when she posted the cover on Instagram. Yet there may be downsides to this idea of “fat acceptance”, as it is sometimes called. Doctors want to warn people about the physical risks of being overweight – not only for the sake of their personal health, but also because of the wider impact on medical budgets. So does fat acceptance mean we face a clash between people’s health and their happiness? And if so, which should take priority? This is an issue that goes beyond one magazine cover, as almost all countries are seeing rising numbers of their citizens classed as overweight. Obesity is the top public health problem facing most Western nations. We have long known that being significantly overweight comes with certain health risks, such as a higher rate of heart attacks. More recently, we have found that just being moderately overweight makes people more prone to developing diabetes, which can lead to complications such as foot amputations and blindness.
9-26-18 We thought the Incas couldn’t write. These knots change everything
A lost language encoded in intricate cords is finally revealing its secrets – and it could upend what we know about Incan history and culture. THE Incas left no doubt that theirs was a sophisticated, technologically savvy civilisation. At its height in the 15th century, it was the largest empire in the Americas, extending almost 5000 kilometres from modern-day Ecuador to Chile. These were the people who built Machu Picchu, a royal estate perched in the clouds, and an extensive network of paved roads complete with suspension bridges crafted from woven grass. But the paradox of the Incas is that despite all this sophistication they never learned to write. Or did they? The Incas may not have bequeathed any written records, but they did have colourful knotted cords. Each of these devices was called a khipu (pronounced key-poo). We know these intricate cords to be an abacus-like system for recording numbers. However, there have also been teasing hints that they might encode long-lost stories, myths and songs too. In a century of study, no one has managed to make these knots talk. But recent breakthroughs have begun to unpick this tangled mystery of the Andes, revealing the first signs of phonetic symbolism within the strands. Now two anthropologists are closing in on the Inca equivalent of the Rosetta stone. That could finally crack the code and transform our understanding of a civilisation whose history has so far been told only through the eyes of the Europeans who sought to eviscerate it.
9-26-18 Neanderthals had dexterous hands that could have held tools like a pen
Our extinct Neanderthal cousins had big bulky hands that look clumsy, but their bones reveal that they could hold objects in the same way we hold pens. Neanderthals could hold objects between finger and thumb, just like we would hold a pen, because their hands were more nimble than anyone thought. The finding helps explain the many skilful tasks Neanderthals have been shown to have performed, like making tools, painting on cave walls, carving patterns into bird bones and threading sea shells onto string to make jewellery. These activities were hard to explain if they were clumsy. Neanderthal hand bones were much chunkier than ours, implying a lack of fine control. Previous studies of the bones mostly suggested Neanderthals could not perform a “precision grip” with finger and thumb, and instead had to use a “power grip” using their whole fist – the way small children sometimes hold crayons. To find out how they used their hands, Katerina Harvati of the University of Tübingen in Germany and her colleagues studied “entheses”: the points on the bones where muscles were attached. Each enthesis is a raised area of bone. “To the touch it feels like a smooth bump on the surface of the bone,” says Harvati. Her team has developed a 3D scanning method that accurately measures their surface area. A precision grip uses a different set of muscles to a power grip, and those muscles that get used more develop larger entheses. Harvati’s team previously showed this by studying modern humans who had worked different jobs.
9-26-18 A new vaccine raises hopes of someday curbing the tuberculosis epidemic
Two doses cut the disease rate in half for people with a latent TB infection. A new tuberculosis vaccine shows promise in preventing the bacteria from causing disease in people who are infected, but aren’t sick. If approved, it could help control the spread of a disease considered one of the world’s top killers, responsible for 1.6 million deaths in 2017, according to the World Health Organization. In a clinical trial, the new vaccine halved the number of people who developed active TB from latent infections of Mycobacterium tuberculosis, compared with those who received a placebo. Of 1,623 participants treated with two doses of the vaccine and followed for just over two years, 10 went on to develop tuberculosis, an incidence of 0.3 cases per 100 people per year. That’s compared with 22 participants out of 1,660 who received two placebo shots, or 0.6 cases per 100 people per year. The results were reported online September 25 in the New England Journal of Medicine, a day before the United Nations General Assembly’s first high-level meeting on ending tuberculosis. “The results are extremely encouraging,” says Richard Chaisson, an infectious disease physician and director of the Johns Hopkins Center for Tuberculosis Research, who was not involved in the research. “This is the first study of new tuberculosis vaccines that has had such dramatic results.”
9-26-18 Mediterranean diet 'may help prevent depression'
Eating a Mediterranean diet may help prevent depression, research suggests. But an expert in metabolic medicine says more rigorous, targeted trials are needed to confirm evidence of the potential link. The findings, in Molecular Psychiatry, come from a review of 41 studies published within the last eight years. A plant-based diet of fruit, veg, grains, fish, nuts and olive oil - but not too much meat or dairy - appeared to have benefits in terms of mood. Experts say trials are now needed to test the theory and to learn whether depression can be treated with diet. Dr Camille Lasalle, who carried out the analysis with colleagues at University College London, said the evidence so far pointed to the idea that the foods we eat can make a difference in lowering our risk of depression, even though there is no solid clinical proof yet. Explaining the link between mood and food is tricky. There are lots of other factors that may be involved. 1. Being depressed can cause loss of appetite, and someone who is feeling low might not look after themselves so well. 2. Happy people may be more likely to lead healthier lifestyles (not drinking too much alcohol - a known mood depressant). 3. It might be that eating bad foods - lots of sugar and highly processed foods - increases the risk of depression, meaning eliminating these from your diet is important. Without tightly controlled trials, it is unclear how big an impact following a Mediterranean diet might have.
9-26-18 Emily Balskus uses chemical logic to study the microbiome
Scientists know a lot about which microbes live in the human gut, but not what they do. Chemist Emily Balskus of Harvard University is out to expose the crimes and misdemeanors of microbes living in the human gut. She’s shown, for example, how a common gut bacterium interferes with a heart failure treatment: The microbe breaks down the medication before the drug can do its job. Balskus, 38, originally imagined a career making complex molecules in the lab. “She can do chemistry that very few people in the world can do,” says synthetic chemist Eric Jacobsen, her Ph.D. adviser at Harvard. But she became intrigued by how microorganisms make molecules with such ease, when synthesizing those molecules can be so challenging. As a postdoctoral fellow at Harvard Medical School, Balskus attended a seminar on the human microbiome — the catchall term for the trillions of invisible beings that live in and on us. She was hooked. “I just thought it was fascinating,” she says. “We have all these microbes living in us from the time we are born. They’re such an intricate part of our bodies. They’re interacting with us, yet we know so little about them.” A growing body of evidence links several illnesses to changes in the body’s microbial communities. While many researchers are out cataloging what these microbial residents are, Balskus is taking a different approach. Rather than focusing on the whodunit, she is interested in the howdunit. “We really don’t understand … how they are exerting their influence,” Balskus says of the body’s microbes. “It’s a major obstacle and it’s what makes this work so exciting.”
9-26-18 Ibrahim Cissé unlocks cells’ secrets using physics
His movies are reshaping views of how genes are turned on. Ibrahim Cissé expected to join his father’s law firm one day. “There were no scientists where I grew up in Niger,” says the MIT biophysicist. “I certainly didn’t know [science] was a profession one could do.” But Cissé’s parents had a telling clue about their young son’s eventual career path: a door sign he made that read “Laboratoire de Cissé.” Cissé learned about experiments in books, but his school in Niger’s capital city of Niamey didn’t have a lab. So, when he was about 10 or 11, he converted a storage room in his family’s house into an experimentation space. Behind that handmade sign, he tore apart electronics, rewired them, built new things with the parts and dreamed about becoming an astronaut on the space shuttle. “People knew that anything that went into my lab was fair game for me to break apart,” he says. At 17, Cissé moved to North Carolina to learn English. Later, on registration day at North Carolina Central University in Durham, a historically black college, a physics professor quizzed him about math and science and suggested Cissé major in physics. Then came the magic words: “We have a grant from NASA.” Recalling his cosmic childhood dreams, Cissé became a physics major. Cissé, now 35, is “everything you could want in a young scientist,” says Anthony Hyman, a biologist at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany, who follows his work. “He’s dynamic, enthusiastic and interested.” These days, Cissé, a newly minted American citizen, is breaking paradigms instead of electronics. He and colleagues are making movies using super-resolution microscopes to learn how genes are turned on.
9-26-18 Lisa Manning describes the physics of how cells move
Seeing cells as ‘living materials’ provides a new way to understand their behavior. Think of tissues as mosh pits of cells. The cells may not be able to crowd surf, but they can jam. Specifically, cells can undergo a jamming transition, a physical role change that was previously known to occur only among foams, sand and other nonliving materials. It’s one of the ways that physicist Lisa Manning has shown how cells get physical with each other — for good and bad. Manning, age 38, describes cells’ behavior in terms of the mechanical forces they exert on one another. Her approach has led to a new understanding of a whole host of biological processes that involve cells on the move, including embryonic development, wound healing and even asthma and cancer. “Forces at the cellular scale are important for properties of tissues,” says physicist Jean Carlson of the University of California, Santa Barbara who was Manning’s graduate adviser. “Lisa has been a real leader in thinking that way.” Manning first blended physics and biology in high school. She was encouraged by her physics teacher in Park Hills, Ky., Sister Mary Ethel Parrott, to try building a biochemical fuel cell, which produces energy from a microbial community. Manning created a mathematical model to figure out the sweet spot: the right amount of sugar to keep the microbes fed and the system running smoothly. “That feeling of discovery is incredibly addictive,” Manning says. She also realized she could describe important aspects of a complex system using a fairly simple mathematical model.
9-26-18 Jenny Tung wants to know how social stresses mess with genes
Being low on the pecking order often means poorer health — but why? Jenny Tung is skeptical when she hears that her older sister, Wenny, compares Jenny’s science to their father’s golf. He played so much because he found it “a big, fat, hairy challenge,” Wenny said, proposing that Jenny, too, is drawn to challenges by their difficulty. Jenny Tung protests. Yet she doesn’t deny that her research tackles a big, hairy question: Why does a tough social life go along with worsening health, even a greater risk of death? Tung, 36, combines evolutionary anthropology and genomics at Duke University to answer this “why,” from the tiniest details of what social adversity does to DNA to the vast evolutionary forces that shape connections between genes and social life. Social scientists have long observed that people of high social status tend to live longer than those on society’s bottom rung — by a decade or more in some studies. But basic questions remain: Why does a low-status life undermine health and how is biology involved? Maybe wealthier people take better care of themselves, paying for the best health care or finding safer jobs. Or healthier humans might find it easier to become wealthier and more successful. Monkeys, however, haven’t evolved health care or what a human would call a job. The animals offer Tung the chance to see more clearly how social hierarchies affect DNA, and thus health.
9-26-18 Female flies evolved serrated genitals that get in the way during sex
Spotted-wing drosophila have evolved a special organ for laying their eggs in fruit, but it makes it difficult for males to hold on when they mate. If female flies choose to lay their eggs in an unusual location there can be surprising knock-on effects for the shape of male fly genitals. Spotted-wing drosophila (Drosophila suzukii), originally from Asia but now found in Europe and North America, are a major pest. While most fruit flies lay their eggs on decaying fruits, females of this species deposit theirs inside unblemished fruits including strawberries, grapes and plums. To pierce the tougher skin of ripening fruit, the females have evolved a modified version of the egg-laying organ – the “ovipositor” – which is longer than those of related species and serrated like a saw. But the females’ large ovipositors are a bit of an obstacle for males during sex. Aya Takahashi and colleagues at Tokyo Metropolitan University, Japan, investigated by examining the mating positions and genital anatomy of D. suzukii and a closely related sister species, D. subpulchrella. They encouraged pairs to copulate and then flash-froze them with dry ice. Male fruit flies generally use various sharply pointed genital structures to hold on to their partners during mating. But because of the length of the ovipositor in spotted-wing drosophila, the males’ genitalia can only grasp its tip. So males have had to develop other ways to stabilise themselves while mating, probably using other genital structures. Takahashi and colleagues found that they have longer, thicker bristles on their anal plates, which come into contact with the ovipositor during copulation.
9-25-18 Quiz: Test your knowledge of evolution
Even spelling the word, evolution, can be tricky when you're seven, but Sophia tells me confidently that evolution "basically means engineering". And Jack says that sharks are lighter underneath so that "when the sun is on the sea, you can't really see the sharks". He's talking about the fact that sharks have evolved a form of camouflage that helps them sneak up on their prey. At the opening of the new Milner Centre for Evolution at the University of Bath, school children are learning about evolution through the help of cuddly sharks of all shapes and sizes, fruit flies and even a tame owl. Their comments reveal a budding interest and knowledge of evolution - at even a tender age. How much do you know about evolution? Test your knowledge here. Evolution is based on well-accepted scientific principles, yet there are many misconceptions. Test your knowledge of evolution here.
9-24-18 Evolution-defying DNA makes mosquitoes infertile by changing their sex
Malaria could be eliminated by a CRISPR 'gene drive' that wipes out the mosquitoes that spread it, transforming the lives of hundreds of millions of people for the better. Countless millions of lives might be saved, and the lives of hundreds of millions transformed for the better, by the first working gene drive. The gene drive completely wiped out all the mosquitoes in small cages in less than a dozen generations. “There were no progeny, not a single one,” says Andrea Crisanti of Imperial College London, whose team’s gene drive is based on the CRISPR gene-editing method . “It goes to extinction.” There are 200 million cases of malaria each year and half a million deaths – mostly among children. Those who survive often have lasting physical or mental impairments. Recurring bouts of malaria can also trap families in a cycle of illness and poverty. “Beyond the human suffering, the economic costs are staggering,” billionaire Bill Gates, whose charitable foundation is helping fund the work, wrote earlier this year. “Used responsibly, gene editing holds the potential to save millions of lives and empower millions of people to lift themselves out of poverty. It would be a tragedy to pass up the opportunity.” Gene drives are pieces of “parasitic” DNA that geneticists insert into one of an organism’s chromosomes. Because chromosomes generally come in pairs, only one of which is passed from a parent to its offspring, usually an extra piece of DNA would only be inherited by half an animal’s progeny. But gene drives “copy and paste” themselves so that they are present in both chromosomes in a pair, meaning they get passed on to all offspring and that the drive spreads throughout a population.
9-24-18 In lab tests, this gene drive wiped out a population of mosquitoes
Success with the genetic engineering tool raises hopes of eliminating the malaria carrier. A new gene drive may push a species of malaria-carrying mosquito to extinction. In a small-scale laboratory study, the genetic engineering tool caused Anopheles gambiae mosquitoes to stop producing offspring in eight to 12 generations, researchers report September 24 in Nature Biotechnology. If the finding holds up in larger studies, the gene drive could be the first capable of wiping out a disease-carrying mosquito species. “This is a great day,” says James Bull, an evolutionary biologist at the University of Texas at Austin who was not involved in the study. “Here we are with a technology that could radically change public health for the whole world.” Gene drives use the molecular scissors known as CRISPR/Cas9 to copy and paste themselves into an organism’s DNA at precise locations. They’re designed to break the rules of inheritance, quickly spreading a genetic tweak to all offspring. The new gene drive disrupts a mosquito gene called doublesex. Female mosquitoes that inherit two copies of the disrupted gene develop like males and are unable to bite or lay eggs. Males and females that inherit only one copy of the disrupted gene develop normally and are fertile.
9-25-18 Gene editing wipes out mosquitoes in the lab
Researchers have used gene editing to completely eliminate populations of mosquitoes in the lab. The team tested their technique on the mosquito Anopheles gambiae, which transmits malaria. They altered part of a gene called doublesex, which determines whether an individual mosquito develops as a male or as a female. This allowed the Imperial College London scientists to block reproduction in the female mosquitoes. They want to see if the technology could one day be used to control mosquito populations in the wild. Writing in the journal Nature Biotechnology, Prof Andrea Crisanti and colleagues report that caged populations of Anopheles gambiae collapsed within 7-11 generations. Dr Crisanti said: "2016 marked the first time in over two decades that malaria cases did not fall year-on-year despite huge efforts and resources, suggesting we need more tools in the fight." The approach falls within a category of genetic engineering known as a gene drive. It describes technologies that spread a gene or particular suites of genes through a population. The researchers used the gene editing technique known as Crispr to modify a part of the doublesex gene that is responsible for female development. Males who carried the modified gene showed no changes, and neither did female mosquitoes with one copy of the modified gene. However, female insects with two copies of the altered gene showed both male and female characteristics, did not bite and did not lay eggs.
9-21-18 Smoking and dementia
Researchers have discovered yet another reason for smokers to quit cigarettes: a reduced risk of developing dementia. For the study, scientists in South Korea regularly examined 46,140 men, all age 60 or older, over an average period of eight years. During that time, 1,644 of the subjects were diagnosed with Alzheimer’s or another type of dementia. After controlling for several factors, the researchers found that the less the men smoked, the less likely they were to develop the disease. Compared with continuous smokers, those who’d quit for up to four years had a 13 percent lower risk—a gap that grew to 14 percent for those who quit for four or more years, and to 19 percent for those who didn’t smoke at all. “Smoking cessation was clearly linked with a reduced dementia risk in the long term,” senior author Sang Min Park, from Seoul National University, tells FoxNews.com. Scientists say that smokers may face a heightened chance of developing dementia because the toxins in cigarettes can damage blood vessels, which in turn restricts blood flow—killing off brain cells used for memory, thinking, and reasoning.
9-21-18 Warning over probiotics
A new study suggests that the much-vaunted health benefits of probiotics may in fact be negligible, and that in some cases the supplements could even be harmful. People ingest these live bacteria and yeasts—usually taken as supplements or in foods such as yogurt or kefir—in the belief that they can top up the “good” bacteria in their gut, reports LiveScience.com. Having a well-cultured “microbiome” has been linked with several health benefits, including reduced heart disease risk and improvements in mental health. But in one of the first studies to sample bacterial mix in the gut, rather than in excrement, researchers in Israel found that most people’s guts were in fact resistant to probiotics. In a separate study, the same team discovered that taking the supplement while on antibiotics could potentially exacerbate metabolic issues such as diabetes and obesity. Because antibiotics can kill off the natural mix of bacteria in the gut, the microbes from probiotic supplements can rapidly take over, delaying the return of the natural gut biome. Co-author Eran Elinav, from Israel’s Weizmann Institute of Science, says the findings call into doubt “the current dogma that probiotics are harmless and benefit everyone.”
9-21-18 Could full-fat dairy be good for you?
Health experts have long warned people away from full-fat dairy products because they contain high levels of saturated fat, which is thought to raise levels of LDL—or “bad” cholesterol. But a major new study has concluded that in moderation, whole milk and full-fat yogurt and cheese could in fact help protect against heart disease and stroke. Researchers examined data from more than 130,000 people across 21 countries over nine years and found that participants who ate two or more daily servings of full-fat dairy had a 22 percent lower risk of heart disease, a 34 percent lower risk of stroke, and a 23 percent lower risk of dying from cardiovascular disease. (A serving was 8 oz of milk or yogurt, or a half-ounce slice of cheese.) Butter consumption wasn’t linked to similar benefits—though that may have been because most of the study’s subjects ate little of it. Study co-author Mahshid Dehghan, of McMaster University in Hamilton, Ontario, says that while full-fat dairy is high in saturated fat, it contains many other nutrients that are important for a healthy diet, such as calcium, magnesium, and vitamin K. “We should not focus on a single nutrient,” she tells Time.com. But Dehghan adds that people should not massively ramp up their consumption of full-fat dairy products, because those foods are high in calories. “The message of the study,” she says, “is moderation.”
9-21-18 The way hunter-gatherers share food shows how cooperation evolved
As the Hadza move between camps, group rules trump individual selfishness or generosity. East African Hadza hunter-gatherers are neither generous nor stingy. But the groups they live in are. That pattern highlights a flexible and underappreciated form of cooperation that may have helped humans go from mobile bands to industrialized states, researchers say. Some camps share food more than others, but Hadza circulate among all camps rather than clustering in the most cooperative ones. Hadza individuals adjust their willingness to share food to the accepted standards, or social norms, of whatever temporary camp they live in, researchers report online September 20 in Current Biology. Social norms develop in poorly understood ways. But factors such as the presence of prolific hunters probably encourage sharing in Hadza camps, says a team led by psychologists Coren Apicella and Kristopher Smith of the University of Pennsylvania. In groups with such norms, cooperators interact only with cooperators and don’t get taken advantage of by those who contribute no food, the researchers say. Group-driven sharing among the Hadza challenges traditional theories of how cooperation evolved. Many researchers have assumed that individuals are consistently generous or selfish. In that case, cooperators seek out other cooperators, but have to guard against being exploited by sneaky, selfish hangers-on. Hunter-gatherers such as the Hadza represent the lifestyles of ancient people better than anyone else today does. Apicella’s findings raise the possibility that cooperation increasingly flourished as hunter-gatherer camps with more cooperative norms survived longer than camps with less cooperative norms, Henrich suggests.
9-21-18 Kidney stones grow and dissolve much like geological crystals
The minerals grow in layers interspersed with areas where the stone has dissolved. It took a close look at crystal formation in Yellowstone’s hot springs to understand stones much closer to home. Growth and dissolution patterns found in rocks there mirror what’s going on with stones in our kidneys, says Bruce Fouke, a geobiologist at the University of Illinois at Urbana-Champaign, contradicting the medical dogma that kidney stones don’t dissolve. Fouke, who usually travels to hot springs and coral reefs for his research on minerals and crystals, had never seen a stone that “doesn’t grow and dissolve, grow and dissolve.” He teamed up with an interdisciplinary research group for “a good, geological look at a kidney stone.” Kidney stones are usually composed of calcium and oxalate, which is found in nuts, rhubarb, beets and other foods. Shining ultraviolet light on thin sections of the stones revealed colorful mineral strata and collections of what look like gems. “You actually go from thin layers to these great, big — I know it’s weird to use this word — beautiful crystals,” Fouke says. The array of hues comes from organic materials — microbes, kidney cells and the chemicals they produce — trapped within the mineral layers, the team explains September 13 in Scientific Reports. Bursts of shape and color map the history of the stone. Bigger crystals dissolve and leave voids that are then filled by new crystals. Fouke suspects that, like the microbes in Yellowstone’s hot springs, kidney microbes may jump-start crystal growth.
9-21-18 Zapping your guts with electricity can help relieve constipation
Passing a gentle electric current through the abdomen encourages bowel movements in people with chronic constipation, a clinical trial has found. Constipation is an uncomfortable and often painful condition that affects up to 15 per cent of the population. Eating fibre, exercising and taking laxatives can help, but some people find that nothing works. Judith Moore at Monash University in Melbourne, Australia, and her colleagues recently tested a new constipation treatment designed to increase bowel motions by stimulating nerves in the gut. They asked 33 women aged 18 to 75 with chronic constipation to use an electrical stimulation device at home for one hour a day for 6 weeks. The device works by sending two medium-frequency electric currents diagonally through the torso via two electrodes stuck to the abdomen and two to the back. As the currents cross internally, they interfere with each other and generate a low-frequency electric current that is optimal for stimulating nerve cells in the gut. Half the participants were assigned to the active treatment and half to a sham treatment, in which the electric currents were directed in parallel so that they were unable to cross over and create the therapeutic current. By the end of the 6 weeks, 58 per cent of participants in the active electrical stimulation group were able to pass more than two spontaneous bowel movements per week, compared to 18 per cent in the sham group. The active intervention group also reported less dependence on laxatives and improved quality of life. These benefits persisted for at least 3 months after they stopped using the device.
9-21-18 50 years ago, a flu pandemic spurred vaccine research
Excerpt from the September 21, 1968 issue of Science News. Flu comes in many kinds, and the current vaccine … has little effect against a newcomer that has afflicted at least 400,000 persons in Hong Kong. The Asian city was the source of the 1957 epidemic in the United States. Fears that it may provide a springboard for another one have caused the Public Health Service to ask eight pharmaceutical companies to begin production of a specialized vaccine.— Science News, September 21, 1968 The 1968 Hong Kong flu pandemic killed about a million people worldwide. A vaccine became available only after the pandemic had peaked. Even today, flu vaccine development is tricky because the three types of influenza virus that infect people are moving targets that change, or mutate, often. But scientists are getting closer to making universal flu vaccines that would protect against many flu strains over multiple seasons. Some candidates target parts of the influenza virus that are less prone to mutate. Others compile all seemingly possible mutations of a particular flu variety into one vaccine (SN: 10/28/17, p. 18).
9-20-18 Can science build a better burger?
There’s more than one way to cook up tomorrow’s meat. This isn’t as extreme as if the federal government had decided to regulate time travel. But it’s almost as surprising. The U.S. Food and Drug Administration is taking the first step toward rules for growing nutritious, delicious, juicy meat in labs, not farms. The notion of growing, say, just the beef instead of the whole cow has been floating around since at least the 1890s. This sci-fi fantasy got a bit more real at a 2013 televised tasting of a lab-grown hamburger, though the patty cost about as much as a Rolls-Royce. In July, the movement passed a new milestone: In a packed auditorium in suburban Maryland, the FDA convened the first public hearing (the U.S. Department of Agriculture is jumping in too) to discuss federal regulation of food grown from cells — no hooves or fins or feathers in sight. What to call such fare is a point of contention. Enthusiasts suggest “clean meat” or “cultured meat.” But calling this stuff “meat” doesn’t sit well with traditional farmers. “They’re hijacking our brand,” Montana rancher Maggie Nutter testified on behalf of the United States Cattlemen’s Association. Meat is harvested from a real animal. Period. (Yet the cells to start a meat-growing culture come from a real animal too.) Whatever it’s called, cultured meat is one of two high-science endeavors to get animals, at least in the traditional sense, out of agriculture.
9-20-18 Earliest known animal was a half-billion-year-old underwater blob
The weird ‘Ediacaran’ fossils have stumped scientists for decades - now fat molecules found inside some of them confirm they are the most ancient animals we know. A strange soft-bodied sea creature that lived over half a billion years ago may have been the first animal species on Earth, fossil evidence suggests. The first large complex organisms – known as the Ediacarans – appear in the fossil record about 570 million years ago, just before the Cambrian explosion of modern animal life. Their alien body shapes have created confusion over whether they were primitive animals, other complex lifeforms like lichen or giant amoebas, or failed experiments of evolution. Now, Jochen Brocks at Australian National University and his colleagues have found fat molecules in 558 million-year-old fossils of Dickinsonia – a type of Ediacaran – that confirms it was an early animal. The researchers collected the fossils from sandstone cliffs in a remote area of the White Sea region of Russia. The cholesterol-like molecules preserved in them are found in almost all of today’s animals, but have low abundance in other lifeforms like bacteria, lichen and amoebas. “It tells us this creature in fact was our earliest ancestor,” says Brocks. Dickinsonia fossils were first discovered in South Australia in 1946. They appear oval-shaped with rib-like segments and can exceed a metre in length. The types of rocks they are found in and their lack of preserved skeletons suggest they were soft-bodied marine creatures, but little is known about which modern animals they are most closely related to. “They look worm-like, but this may be a superficial resemblance,” says Brocks.
9-20-18 Cholesterol traces suggest these mysterious fossils were animals, not fungi
These alienlike organisms lived more than 541 million years ago. Cholesterol clinched it: A group of strange Precambrian fossils are among the oldest known animals in the rock record. Organic molecules preserved with fossils of the genus Dickinsonia confirm that the creatures were animals rather than fungi or lichen, a study in the Sept. 21 Science says. Researchers led by paleontologist Ilya Bobrovskiy of Australian National University in Canberra analyzed levels of steroids in the fossils, which date to between 571 million and 541 million years ago. The team found an abundance of cholesterol that points firmly to the animal kingdom. The finding “gets rid of the more outlandish hypotheses about what these objects were,” says MIT geobiologist Roger Summons, who cowrote a related commentary in the same issue of Science. “You can’t argue with chemistry.” Dickinsonia are part of the enigmatic Ediacara biota, the collective name for a burst of strange, alienlike life forms that flourished during the Precambrian Eon. Ediacarans, originally named for Australia’s Ediacara Hills, where they were first discovered, are now found in Precambrian-aged rocks around the globe.
9-20-18 Earliest animal fossils are identified
Scientists have identified the earliest known animal in the geological record. It's a 558-million-year-old oval-shaped creature that may have borne a superficial resemblance to a segmented jellyfish. Researchers found specimens of the creature, known as Dickinsonia, that were so well preserved they still contained molecules of cholesterol. This fat is a hallmark of animal life, the team reports in the journal Science. Dickinsonia belongs to a group of life forms known as the Ediacaran biota. They were the first complex multi-cellular organisms to appear on Earth. But they have been extremely difficult to classify, and their position on the tree of life has been one of the greatest mysteries in palaeontology. Different teams of scientists have variously classified them as lichens, fungi, protozoans, evolutionary dead-ends and even as an intermediate stage between plants and animals. The new analysis of a specimen found in north-west Russia places Dickinsonia firmly within the animal kingdom."The fossil fat molecules that we've found prove that animals were large and abundant 558 million years ago, millions of years earlier than previously thought," said co-author Jochen Brocks, an associate professor at the Australian National University (ANU) in Canberra. "Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Ediacaran Biota were," he explained, adding: "The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the Holy Grail of palaeontology." The Ediacaran biota appeared around 600 million years ago, and flourished for tens of millions of years before the event called the Cambrian explosion. This massive diversification of life occurred around 541 million years ago; it's when most of the major animal groups appear in the fossil record. The Ediacaran species largely disappear when the Cambrian explosion happens. As such, they straddle an ancient age when the Earth was dominated by bacteria and a later age of dominance by animals.
9-19-18 Humans have skeletal stem cells that help bones and cartilage grow
The newfound cells could one day be used to repair joints and treat osteoporosis. Repairing bones and cartilage may get easier thanks to newly discovered human skeletal stem cells. Scientists found the stem cells, which give rise to bones, cartilage and the spongy bone that harbors bone marrow, in fetal bones, adult bones and fat, researchers report online September 20 in Cell. The researchers also reprogrammed adult cells into skeletal stem cells. A ready supply of such cells could one day help doctors repair or replace joint cartilage, heal broken bones more quickly, build up bone in osteoporosis patients and even grow new bone and cartilage for reconstructive surgeries. Those applications are still far in the future, says Clifford Tabin, a developmental geneticist at Harvard Medical School who was not involved in the study. “The current study is an extremely important advance,” he says, “but there is work to be done before [skeletal stem cells] can contribute to changing the landscape of orthopedic medicine.” Other stem cells collected from fat and cartilage can be coaxed into making bone or cartilage under special circumstances (SN: 3/19/16, p. 23), but those cells are not the dedicated skeletal cells discovered in the new study, says coauthor Michael Longaker, a plastic surgeon at Stanford University School of Medicine.
9-19-18 Over-the-hill cells may cause trouble in the aging brain
Killing senescent cells in the noggins of mice prevented memory loss. Cells past their prime may have a role in dementia. Culling these cells protected the brains of mice that were otherwise destined for brain decline, a new study finds. Senescent cells, which accumulate with age, are still alive but in a state of suspended animation — they stop doing their jobs and they stop dividing. Getting rid of these cells in the body extends the life spans of mice and improves their heart and kidney health, scientists have found (SN: 3/5/16, p. 8). The new research, published online September 19 in Nature, suggests that senescent cells also make mischief in the aging brain. Molecular biologist Darren Baker of the Mayo Clinic in Rochester, Minn., and colleagues studied mice with mutations that led nerve cells in their brains to accumulate a toxic form of the protein tau. Damaging globs of this protein, called neurofibrillary tangles, are a hallmark of Alzheimer’s disease and other dementias. In some of these mice, Baker and colleagues also engineered in a genetic trick — a “kill switch” that destroys cells as soon as they become senescent. In mutated mice with this switch, tau didn’t accumulate as fast. What’s more, these mice were better able to recognize new smells and objects than mice with more senescent cells in their brains. An anticancer drug called navitoclax that targets senescent cells also had protective effects in these mutated mice’s brains.
9-19-18 Killing ‘zombie’ brain cells can prevent memory loss in mice
Dysfunctional, or 'senescent', brain cells can drive brain degeneration – and killing them saved mice from further damage and memory loss. Wiping out zombie-like brain cells that are worn out but won’t kill themselves could provide a new way to prevent or treat Alzheimer’s disease and other types of dementia. That’s the conclusion of experiments in mice showing that if these ‘senescent’ cells are eradicated as they develop through life, the brain is protected against further degeneration. “We show that senescent cells promote neurodegeneration and cognitive loss,” says Darren Baker of the Mayo Clinic in Rochester, Minnesota, and head of the team. “Preventing these cells from accumulating attenuates disease.” Baker studied mice genetically engineered so that their brains degenerate unusually early in life by becoming clogged with damaging clumps of fibres called tau tangles. His team discovered that by the time the mice were a year old, they had also over-accumulated senescent cells. Compared with healthy control mice, they had a dozen times as many senescent cells in the brain’s memory centre – the hippocampus – and twice as many in the cortex, the “thinking” hub of the brain. To find out if senescent cells also drive the tau-related brain degeneration, the researchers crossed the tau tangle-prone mice with mice whose senescent cells could be selectively destroyed as they emerged throughout life by treating the mice with a drug called AP. Destroying the senescent cells halted brain degeneration in the tau tangle-prone mice, and prevented their usual loss of memory and cognitive ability.
9-19-18 Milk alternatives: Which are good for both you and the planet?
Milks made from peas, nuts and more are taking supermarket shelves by storm. Here's what you should be drinking if you care about your health and the environment. MOVE over cows, there’s a new milk in town. There are many, actually. The old alternatives – soy, rice and coconut milk – are now joined on grocery shelves by alt-milks made from almonds, cashews, macadamia nuts, oats, peas, flax, hemp – the list goes on and on. You can even buy milk made from potatoes or bananas. Since 2012, non-dairy milk sales in the US have risen 61 per cent, according to market research by Mintel. There is a similar trend in the UK, with plant-milk sales up a third since 2015. More than half of that is almond milk, with soy and coconut milks making up another quarter of the market. As you might expect for the latest food trend, these milks are mostly bought by millennials, or adults younger than 35. Manufacturers appeal to that generation’s values by positioning the products as a healthy alternative, both for the body and the planet. But is that really true? Nutritionally, it depends on which milk replacement you consider. In general, they are made by grinding up plants and soaking them in water, then adding emulsifiers and stabilisers to thicken the liquid and keep it from separating, but they have a lot of variety (see “What’s in a name?“). In terms of protein, soy milk is quite like cow’s milk, and it contains similar omega-3 fatty acids that are important for heart health. Almond and cashew milks have less than half the calories found in cow’s milk, but are lower in protein. Coconut and hemp milk have a rich texture owing to their high fat content and they also include a small amount of dietary fibre not found in cow’s milk. Oat and rice milks are higher in carbohydrates than both cow’s milk and other plant-based alternatives.
9-19-18 Smart pills can transmit data to your doctors, but what about privacy?
9-19-18 The mystery of the dinosaur with crocodile jaws, bear claws and a sail
No one knows why dinosaurs never conquered the seas. But giant semi-aquatic predator Spinosaurus is revealing some teasing hints. HAVE you heard the one about the blind men and the elephant? One man feels its tail and thinks the animal is like a sturdy rope. Another touches its tusk and says, no, an elephant is like a spear, and so on. The moral of this ancient parable is that we shouldn’t assume too much from personal experience. But there is a more literal message that no scientist should ignore: unfamiliar animals with strange features are hard to understand if you can’t see the living, breathing beast. Over the past few years, palaeontologists have been working on their own version of the parable, with one of the most fearsome animals ever at the heart of it. Look at the jaws of Spinosaurus and you might conclude it was like a crocodile. Examine its gigantic claws and it is like a bear. Its broad, flat toe bones are like those of a wading bird. What could the life of a creature with such apparently conflicting features have been like? “It’s almost like working on an extraterrestrial,” says Nizar Ibrahim at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, who is excavating the bones of one of the most complete specimens we have found. Making sense of this fantastic beast would pay dividends, because Spinosaurus might explain one of the biggest mysteries of dinosaur evolution. Everyone agrees that Spinosaurus was a giant. We don’t have a complete skeleton, but estimates suggest it was about 15 metres long, making it the largest carnivorous dinosaur yet found.
9-19-18 Daily low-dose aspirin is not a panacea for the elderly.
In fact, taking aspirin regularly may harm healthy older people A daily dose of aspirin? Not a good idea if you’re a healthy elderly adult. A trio of papers based on a large-scale clinical trial finds that the drug doesn’t help to stave off heart attacks, strokes, dementia or physical disability. In fact, those in their golden years who took a low dose of aspirin daily were more likely to suffer serious internal bleeding than those who took a placebo. The researchers even observed more deaths among those on aspirin, although that result wasn’t statistically significant. The clinical trial, called ASPREE or Aspirin in Reducing Events in the Elderly, included more than 19,000 adults. About half of those adults were randomly assigned to take 100 milligrams of aspirin per day and the other half a placebo pill for around five years. The papers, published online in the New England Journal of Medicine on September 16, “once again remind us that aspirin is not a benign drug,” says cardiologist Jeffrey Berger of New York University School of Medicine who was not part of the research. “There’s a lot of misunderstanding of the original data in support of aspirin,” he says. The notion that everyone in older age should take aspirin to prevent a first heart attack or stroke, Berger says, “is not born out from the evidence to date.” Yet a 2015 study found that nearly half of 2,039 U.S. adults ages 45 to 75 who didn’t report a history of cardiovascular disease were regularly taking aspirin.
9-18-18 The whiff of sandalwood makes the human head sprout more hair.
Your scalp can "smell" things - and when it detects synthetic sandalwood, the rate of hair growth increases. There are all sorts of potential treatments for hair loss, including pills, injections, and even the suggestion of plucking the hairs that remain. Now comes a new idea: the odour of synthetic sandalwood may promote hair growth. The nose is the obvious place to look for the olfactory receptors that detect odours, but researchers now know that similar receptors are found in many parts of the body. This includes the skin around hair follicles, where cells produce an olfactory receptor called OR2AT4 that plays a role in various physiological responses, such as fixing a cut. Ralf Paus at the University of Manchester, UK, and his colleagues say there is already good evidence that forming a new hair uses a similar set of molecular tools as forming a patch of new skin after a wound. This made them wonder whether activating OR2AT4 could promote hair growth. To test the idea, the team used samples of human scalp donated by volunteers who had undergone facelift procedures, and immersed them in synthetic sandalwood odorant for six days. They chose the synthetic sandalwood scent because it is an odour molecule particularly likely to bind to the OR2AT4 receptor. The researchers found a 25 to 30 per cent increase in the secretion of a growth hormone in the scalp. In other words, the hormone plays a key role in promoting hair growth.
9-18-18 Smart plants can teach us a thing or two
The Revolutionary Genius of Plants challenges the brain-centered view of intelligence. More than 200 years ago, French botanist René Desfontaines instructed a student to monitor the behavior of Mimosa pudica plants as he drove them around Paris in a carriage. Mimosa pudica quickly closes its leaves when touched — presumably as a defense mechanism. Desfontaines was interested in the plants’ response to the continuous vibrations of the ride. Initially, the leaves closed, but after a time, they reopened, despite the shaking. “The plants are getting used to it,” the student wrote in his notebook. Stefano Mancuso recounts this tale in The Revolutionary Genius of Plants and reports on a modern follow-up: a repeat of the experiment (without the carriage) demonstrating that plants can indeed learn that an external provocation is harmless and remember what they’ve learned for weeks. Learning is impossible without memory, and both are hallmarks of intelligence, argues Mancuso, who leads the International Laboratory of Plant Neurobiology at the University of Florence in Italy. But our animal-centric view of neuroscience makes us loathe to employ terms like “memory” and “intelligence” when talking about organisms without a brain. With infectious passion, Mancuso sets out to convince us that the plant way of doing things not only deserves our respect, but also may help us solve greater societal woes. The M. pudica story sets the stage for an eye-opening philosophical argument that makes the book worth a close read — you will never look at plants, or animals, the same way again. To overcome the human bias toward brain-centered intelligence, Mancuso writes, one must consider that, unlike animals, plants can’t move.
9-18-18 Artificial genes show life does not have to be based on DNA
Two modified versions of DNA add different “letters” to life’s genetic code but still work just as well as the original. Life need not be based on DNA. So say researchers who have created two new versions of the iconic molecule, which retain its double helix shape but are thinner or chunkier than the original. “This is changing the rules of the game that every schoolchild learns,” says Steven Benner of the Foundation for Applied Molecular Evolution in Alachua, Florida. It implies that extraterrestrial life might be based on alternative genetic molecules. DNA carries our genes, which tell our bodies how to grow and are passed from parent to child. The structure of DNA was described in 1953 by James Watson and Francis Crick – with crucial help from Rosalind Franklin. Watson and Crick realised that DNA is made up of two long chain-like molecules twisted around each other. The two chains are attached to each other via pairs of bases, one base on each chain. There are four types of base, and they only pair up in specific ways: adenine with thymine, and guanine with cytosine. The information in our genes is contained in the order of the bases. Benner and his colleagues made several alternative DNAs, in which they swapped out some of the standard bases for various combinations of eight similar molecules. Doing so made some of the resulting DNA-like molecules physically “skinnier” than standard DNA, while others were “fatter”. Nevertheless they all performed DNA’s crucial function: if two bases paired incorrectly, the misplaced one was swiftly ejected and replaced with the correct one. This is how DNA ensures our genes don’t become garbled, and the modified DNA did it just as well. “I was quite surprised,” says Benner.
9-18-18 A third of us would go one-way to Mars – but it may shrink your brain
New Scientist Asks the Public has revealed that 40 per cent of men want to go to Mars, but new evidence suggests the lengthy trip may be bad for your brain. Many people would consider going on a one-way mission to Mars, according to the 2018 New Scientist Asks the Public survey. But new evidence suggests that the lengthy trip may be bad for the part of your brain involved in forming memories. The survey, carried out in August by Sapio Research on a representative sample of 2026 UK adults, found that 50 per cent of men and 30 per cent of women would be happy to go on a return trip to Mars. As for a one-way trip, 40 per cent of men said they would definitely or probably want to go, compared with 20 per cent of women. This is despite the known physical risks that the six-month journey to Mars would involve. Aside from space-flight accidents, high exposure to radiation from cosmic rays could lead to DNA damage and cancer. And there may be other unanticipated dangers. A NASA study presented at the recent Federation of European Neuroscience Societies conference in Berlin, Germany, suggests that a two-year mission with just a handful of crewmates could damage the brain. The study involved 16 volunteers doing 30-day stints in a simulated Mars base with only three other people for company in their pod. By the end of the study, the participants showed slight shrinking of a brain area called the hippocampus, made up of sausage-shaped structures that are essential for forming new memories. The study found that one end of the volunteers’ left hippocampus – known as the head end – shrank by about 3 per cent on average.
9-17-18 A recount of human genes ups the number to at least 46,831
The new estimate is based on a broader definition of just what a gene is. Figuring out how many genes are in the human genetic instruction manual, or genome, isn’t as easy as scientists once thought. The very definition of a gene has changed since the completion of the Human Genome Project more than 15 years ago. Genes used to be defined as stretches of DNA that contain instructions that are copied into RNA and then turned into proteins. Researchers still don’t entirely agree on how many of these protein-coding genes there are. Estimates range from 19,901 to a new count of 21,306 published August 20 in BMC Biology. But in the last decade, researchers have learned that not all genes produce proteins. Many scientists have expanded the definition of a gene to include ones that make RNAs that, instead of being turned into proteins, have other functions in the cell. Numbers of RNA-producing genes (also called noncoding genes) are even more up in the air than protein-coding genes, says Steven Salzberg, a biostatistician at Johns Hopkins University who headed the new count. His team has already found more of these RNA genes — 25,525, including 18,484 long noncoding RNA, or lncRNA genes (SN: 12/17/11, p. 22) — than protein-coding ones, and his count doesn’t include microRNAs and other recently discovered small RNAs. Even without the small RNAs, Salzberg’s new total of human genes comes to at least 46,831. Other scientists have debated the estimate, and Salzberg says, “I will not be surprised if 10 years from now, we still don’t have an agreed-upon number.”
9-17-18 Egyptian archaeologists find sphinx at Aswan temple
Egyptian archaeologists have discovered a statue of a sphinx while draining water from the pharaonic temple of Kom Ombo near the southern city of Aswan. The antiquities ministry said the statue of the mythical beast, which measures about 28cm (11in) wide and 38cm tall, was made of sandstone. It probably dates back to the Greco-Macedonian Ptolemaic dynasty, which ruled Egypt from 305BC until 30BC. Two sandstone reliefs of King Ptolemy V were also recently found at the temple. After the coronation of Ptolemy V, who ruled from 210BC until 180BC, priests at the sacred city of Memphis issued the famous Rosetta Stone, which listed his noble deeds. Many centuries later, the stone helped experts learn to read ancient Egyptian hieroglyphs. The temple of Kom Ombo, where the sphinx was found, was built during the reign of his son, Ptolemy VI. It hosted the twin gods Sobek and Haroeris. The head of Aswan's antiquities department, Abdul Moneim Saeed, said experts would carry out further studies of the statue to find out more about its purpose. The sphinx represented royal power in ancient Egypt, combining the physical strength of a lion with the worldly might of a king. The Great Sphinx by the pyramids of Giza is the largest and most famous. Standing 20m (65ft) tall and 57m long, it is believed to have been carved from an outcrop of limestone during the reign of Khafra, a king of the Fourth Dynasty who ruled from 2558BC to 2532BC.
9-16-18 'Aspirin-a-day risky in old age' - major study
Elderly people in good health should not take an aspirin a day, according to a major study in the US and Australia. There are proven benefits of the drug for people after a heart attack or stroke. But the trial found no benefit for healthy people over the age of 70, and the pills increased the risk of potentially fatal internal bleeding. Experts described the results as very important and cautioned against self-medicating with aspirin. People are prescribed aspirin after a heart attack or stroke because the drug thins the blood and reduces the chances of a repeat attack. Some completely healthy people also choose to take aspirin to reduce their risk and there is continuing research into whether the drug can be used to cut the risk of cancer. However, most research on the benefits of aspirin is performed on people in middle age and there is mounting evidence the dangers increase as we get older. The study was of 19,114 people in the US and Australia in good health, with no history of heart problems and over the age of 70. Half were given a daily low-dose aspirin for five years. Three reports in the New England Journal of Medicine showed the pills did not reduce their risk of heart problems or have any other benefits. They did increase the number of major stomach bleeds. Prof John McNeil, from Monash University, said: "It means millions of healthy older people around the world who are taking low dose aspirin without a medical reason, may be doing so unnecessarily, because the study showed no overall benefit to offset the risk of bleeding. "These findings will help inform prescribing doctors who have long been uncertain about whether to recommend aspirin to healthy patients."
9-16-18 How drugs affect our agency
Do drugs help or hinder the human experience? From medication to recreational and spiritual substances, drugs offer us respite from pain, open opportunities for mental exploration, and escape from — or into — altered psychological states. They are our most widely available formal and informal implements for tweaking our mental condition. Consider the cold beer after a hard day at work, the joint before putting the needle on the record, the midday espresso, the proverbial cigarette break, Adderall during finals week, or painkillers to alleviate undiagnosed or chronic pain. Not to mention antidepressants to counter a sense of meaninglessness, and benzodiazepines because everything causes anxiety. In short, drugs offer our most common path to a sense of psychological health. With a modicum of knowledge, millions of people modify their minds through chemistry every day. Considering the limited resources of time, support networks, money, and patience, accepting the positivism of drugs seems more efficient and more feasible than psychodynamic therapy. This shift implies an expectation that there are quick and easy chemical levers into a wide range of mental states. Drugs are favored tools to foster our values and amplify or attenuate our gregariousness and productivity. They serve as release valves for labor and social relations. Socially acceptable drugs such as nicotine, caffeine, and alcohol are thus embedded into common social practices in public spaces; they are aids to efficiency in coffee-shop work culture and sociability in bars. Accordingly, these practices coincide with the modern structure of the working week: In the morning we become alert, and in the evening we relax. In effect, some drugs are made highly accessible as a form of self-medication for the common self-diagnosed emotional states of stress, boredom, restlessness, anxiety, discomfort, and so on.
9-15-18 'World's oldest brewery' found in cave in Israel, say researchers
Researchers say they have found the world's oldest brewery, with residue of 13,000-year-old beer, in a prehistoric cave near Haifa in Israel. The discovery was made while they were studying a burial site for semi-nomadic hunter-gatherers. Brewing beer was thought to go back 5,000 years, but the latest discovery may turn beer history on its head. The findings also suggest beer was not necessarily a side product of making bread as previously thought. The researchers say they cannot tell which came first, and in October's issue of the Journal of Archaeological Science: Reports, they suggest the beer was brewed for ritual feasts to honour the dead. "This accounts for the oldest record of man-made alcohol in the world," Li Liu, a Stanford University professor who led the research team, told Stanford News. Ms Liu said they were looking for clues into what plant foods the Natufian people - who lived between the Paleolithic and Neolithic periods - were eating, and during the search they discovered the traces of a wheat-and-barley-based alcohol. The traces analysed were found in stone mortars - up to 60cm (24in) deep - carved into the cave floor, used for storing, pounding and cooking different species of plants, including oats, legumes and bast fibres, such as flax. The ancient brew, which was more porridge or gruel-like, is thought to have looked quite unlike what we know as beer today. The research team has managed to recreate the ancient brew to compare it with the residue they found. This involved first germinating the grain to produce malt, then heating the mash and fermenting it with wild yeast, the study said. The ancient booze was fermented but probably weaker than modern beer.
9-14-18 A muscular dystrophy fix?
Scientists have used gene editing to correct the mutations behind a form of muscular dystrophy in dogs—a major breakthrough that raises hopes the same procedure could be used to cure the disease in humans. The most common fatal genetic condition in children, Duchenne muscular dystrophy, is caused by a genetic mutation that prevents the body from producing dystrophin, a protein essential for strong muscle fibers. If the gene is mutated, muscles—including the heart and diaphragm—waste away, reports The Guardian (U.K.). For this study, researchers used the gene-editing technology CRISPR to restore dystrophin production in four dogs. Within weeks of receiving the injection-administered treatment, the dogs had significantly improved levels of dystrophin: a 92 percent correction in the heart and a 58 percent change in the diaphragm. The researchers estimate that as little as 15 percent improvement could dramatically help people with Duchenne. They are now planning more extensive studies on dogs. “If everything were to continue smoothly,” says lead researcher Eric Olson, from the University of Texas Southwestern Medical Center, “we might be able to anticipate moving into a human trial in a few years.”
9-14-18 Mummified ice age wolf pup and caribou found in northern Canada
The rare remains of an ice-age wolf pup and a caribou will offer insights about life in Canada's far north more than 50,000 years ago, scientists say. The creatures were discovered with intact hair, skin, and muscle tissue. They were found in 2016 by miners near Dawson City in Yukon, and handed over to palaeontologists for research and analysis. They are among the oldest mummified mammal soft tissue in the world, palaeontologist Grant Zazula said. The wolf pup is estimated to have been about eight weeks old when it died. "It's beautiful, the fur, it's got the cute little paws and tail and the curled upper lip showing its teeth. It's spectacular," Mr Zazula told the Canadian Press news agency on Thursday. The caribou remains include the torso, head, and front limbs. Both specimens are currently on display in Dawson City and will eventually be sent to the Canadian Conservation Institute near Ottawa. They are expected to help scientists understand how they lived in the environment they inhabited. Other creatures who roamed the region from that era, such as the woolly mammoth and even a species of camel, are extinct. But distant descendants of both the wolf pup and caribou can still be found wandering the Yukon.
9-14-18 Heart-tugging tales of crowdfunded cancer ‘cures’ fuel quack medicine
Media stories about people with cancer seeking controversial cures are unwittingly bolstering unscientific and potentially harmful treatments, says Michael Marshall. Crowdfunding campaigns to help people with cancer pay for expensive and ineffective alternative treatments are becoming more common. These often set six-figure targets in order to meet the fees charged for controversial therapies. Newspaper headlines are almost guaranteed and fuel the flow of money to the clinics involved. The BMJ this week reports concerns over this, based on information I gathered working for the charity Good Thinking. By sifting fundraising sites like JustGiving and GoFundMe to identify appeals from people in the UK who sought funding for unproven or disproven treatments, I was able to find more than 400 such appeals in the past three years. Those 400 have raised £7 million, the vast bulk of which pays for treatments abroad. Although the treatments in question, which include extreme diets and alkaline therapy, aren’t backed by scientific evidence, people who are desperate and vulnerable are often tempted by remarkable testimonials. They may link the high costs with a greater chance of successful treatment, encouraging friends and family to join the fundraising effort and help spread the word. For those of us who see such stories emerge in the media, and who care about following good scientific evidence, the natural reaction is to try to protect people from the potential damage caused by ineffective treatments, whether that is physical, emotional or financial. Unfortunately, any attempt to question the value of an intervention – however considerately and compassionately couched – is destined to fail. People view these therapies as beacons of hope, and their supporters don’t want to consider that their efforts to help may actually cause harm.
9-13-18 Brain features may reveal if placebo pills could treat chronic pain
Structural changes in the organ predicted who responded to sugar pills as treatment. Certain brain and personality characteristics may help predict whether a sugar pill can provide relief to someone suffering from chronic pain. In a small study, patients with persistent back pain who responded to a placebo treatment benefitted from up to a 33 percent reduction in their pain intensity. These people had distinctive features in their brains and certain personality traits, researchers report online September 12 in Nature Communications. About 20 percent of U.S. adults, or about 50 million people, had chronic pain in 2016, according to new data released September 13 by the U.S. Centers for Disease Control and Prevention. Chronic pain was defined as feeling pain on most days, if not every day, over the previous six months. Being able to identify people who respond to a placebo might mean doctors could give these individuals the option of a pain reliever that’s cheap, free of side effects and — unlike opioids, which are often prescribed to treat persistent pain — not addictive. “We need to seriously think about placebo as a treatment option, especially in chronic pain patients,” says neuroscientist and study coauthor A. Vania Apkarian of Northwestern University Feinberg School of Medicine in Chicago.
9-13-18 BPA-free plastics seem to disrupt sperm and egg development in mice
We are starting to replace harmful BPA in plastic bottles and food containers, but alternative chemicals might be just as bad. Many plastic bottles are sold as “BPA-free” – meaning they don’t contain bisphenol A, an ingredient known to disrupt reproduction in mice. But now it seems that the additives used in place of BPA are potentially just as harmful. The discovery could mean that the replacements, such as bisphenol S (BPS), might potentially affect people if they leach out into food or drink. There’s no evidence yet that this happens. But the new results from mice suggest that if there is a risk, it may match that posed by BPA itself. “Several of these bisphenols induce changes in the germline similar to those we reported previously for BPA,” says Patricia Hunt of Washington State University in Pullman, who helped draw attention to the BPA problem 20 years ago. Hunt’s latest discovery emerged in the same way as her BPA findings. As before, she noticed that mice kept in certain plastic cages began to show reproductive problems, such as abnormal eggs and low sperm counts. As with BPA, she found the inner surfaces to which mice were exposed were contaminated, this time with BPS that had leached out from the plastic. Hunt investigated the problem in greater detail by exposing female mice fetuses to tiny amounts of a selection of BPA replacements at the point where their eggs are developing. She also exposed male mice to the chemicals just after birth, when they begin developing sperm.
9-13-18 Bandages laser-bonded to your skin may fix wounds better than stitches
Most flesh wounds are repaired with sutures, but they cause extra damage to the skin. A bandage made of silk and gold, sealed with laser light, could solve that. Wound repair is usually about fighting fire with fire – using sutures and staples that pull the skin together but that add more damage to the surrounding tissue in the process. But the job can be done without that additional damage using a silk and gold bandage sealed with a laser. What’s more, the approach may lower the risk of infection. Kaushal Rege at Arizona State University and his colleagues developed a type of bandage that seals together wounds as effectively as sutures, but does not involve puncturing the skin. It is made of silk, which is dissolved and mixed with gold nanorods and then dried out into a thin strip. When a laser is shone on the bandage, the gold converts the light into heat. The heat causes structural changes in the molecules of the silk and in the collagen of the tissue it’s applied to, and they intertwine like Velcro, bonding the silk to the tissue. The researchers tested the silk sealant on bits of pig intestine filled with saline solution and found that the incisions closed up with lasers and the new bandage withstood seven times more fluid pressure before bursting than those closed with sutures. This makes bandage-patched wounds about as strong as the intact intestine. The new bandage also stopped bacteria from leaking between the inside and outside of the intestine. They also tested the bandages on small incisions made in the skin of live mice. After two days of healing, the laser-sealed skin had less inflammation and was stronger than skin that was sutured or glued back together.
9-13-18 Gluten may be making you tired and depressed according to a new study
Gluten might not cause gut problems in people who don’t have coeliac disease, but a study of 14 people suggests it may occasionally cause fatigue or depression. Some people say they don’t feel good after eating gluten – but perhaps that’s because of its effects on mental health rather than on the gut. Gluten is a protein in wheat that causes coeliac disease – a serious autoimmune condition – in about 1 per cent of people. A further 12 per cent of people say they experience bloating, cramps, tiredness, depression and other symptoms after they eat gluten-rich foods like bread and pasta. But researchers can’t agree whether this “non-coeliac gluten sensitivity” is a real condition or not. Several studies have seemingly debunked it by showing that sufferers report the same gluten sensitivity symptoms even if they eat an inactive substance they think is gluten. Others have found that certain carbohydrates in wheat called fructans are probably more to blame for gut symptoms. However, even if gluten doesn’t cause gut troubles, it may trigger other non-digestive symptoms in some people, says Jessica Biesiekierski at La Trobe University in Australia. Biesiekierski and her colleagues recently tested the effects of gluten on gastrointestinal and psychiatric symptoms in 14 people with self-reported gluten sensitivity. In one experiment, the participants were asked to eat a special form of yoghurt on separate days two weeks apart. On one of the days the yoghurt contained gluten, on the other day it was gluten-free.
9-13-18 Elephant birds: Who killed the largest birds that ever lived?
Prehistoric humans are under suspicion of wiping out the largest birds that ever lived after fossilised bones were discovered with telltale cut marks. According to scientists, it's evidence that the elephant birds of Madagascar were hunted and butchered for food. The remains have been dated to about 10,000 years ago. Until now, the first settlers were thought to have arrived on the island about 2,500 to 4,000 years ago. "This does push back the date of human arrival by 6,000 years, at least," says Dr James Hansford, a scientist at Zoological Society London, UK. As well as raising questions about human history, the discovery suggests a "radically different extinction theory" is required to understand the loss of the island's unique fauna. Rather than wiping out the animals in a short time, humans seem to have lived alongside the birds for thousands of years, before they went extinct around 1,000 years ago. "Humans seem to have coexisted with elephant birds and other now-extinct species for over 9,000 years, apparently with limited negative impact on biodiversity for most of this period, which offers new insights for conservation today," says Dr Hansford.
9-12-18 We may have reached Madagascar 6000 years earlier than once thought
Cut marks on giant bird bones suggest humans reached Madagascar 10,000 years ago and may have coexisted with the island’s now extinct megafauna for millennia. Humans may have first sailed to Madagascar more than 10,000 years ago – 6000 years earlier than previously thought. Archaeologists has been grappling with the question of when humans settled on Madagascar for years, because they have limited evidence to work with. Previous findings of animal bones and tools suggested humans might have been present on the island by 4000 years ago, although the evidence is disputed. James Hansford at the Zoological Society of London and his colleagues have now found evidence of an earlier human presence. On 10,000-year-old bones of extinct elephant birds — once the world’s largest bird — the researchers found cut marks left by human butchers. Nearly a decade ago, researchers recovered the elephant bird bones near the Christmas River in southern Madagascar. Carbon dating indicated they were more than 10,000 years old. Although no tools or other human-made products were discovered at the site, Hanford and his colleagues have now realised that the bones carry scratch marks that look like impacts from stone blades. Hansford compared the cut marks with previously identified tool marks on animal bones and modern butchery marks, and concluded that they were made by humans. “Tool use on fresh bones leaves unmistakable patterns,” Hansford says. “No natural erosion process could have made these marks.”
9-12-18 Butchered bird bones put humans in Madagascar 10,500 years ago
Cut marks on the remains of an ancient elephant bird pushes the timeline back 6,000 years. Humans made their mark on Madagascar around 6,000 years earlier than previously thought, scientists say. Those early migrants hunted massive, flightless birds once native to the island off southeast Africa, leaving butchery marks on the bird bones that enabled the new timeline. Cuts and fractures on three previously unearthed leg and foot bones from one of Madagascar’s extinct elephant birds resulted from the animal being killed and cut up with stone tools at least 10,500 years ago, say vertebrate paleontologist James Hansford of the Zoological Society of London and colleagues. Until now, the oldest evidence of humans on Madagascar consisted of stone tools dating to roughly 4,000 years ago. Two other island sites, dating to about 6,300 years ago and 1,100 years ago, have also produced elephant bird leg and foot bones with butchery marks that showed up on closer inspection, Hansford’s group reports online September 12 in Science Advances. Elephant birds stood about 3 to 4 meters tall and weighed around 500 kilograms, roughly the same as three full-sized refrigerators.
9-12-18 It’s an outrage that Turkey is ditching Darwin from science textbooks
Evolution is being dropped from school biology texts in Turkey. In Hungary, academic freedoms are increasingly threatened. Time to worry, says Rachael Jolley. As Turkish children go back to school, they will see significant changes to biology lessons that risk limiting their understanding of the world. In Hungary, academic freedoms are also under attack. Both changes are down to the rise of authoritarian politics and they put science education and research independence in danger. In Turkey, information about natural selection and Charles Darwin‘s theory of evolution is being removed from secondary-school biology texts for 15-year-olds as part of an ongoing move away from a secular schooling system. Announced last year, the changes are taking effect this month after an onslaught of criticism about the teaching of evolution by Turkish preachers led by Islamic creationist Adnan Oktar, who hosts his own television show. Oktar, who also runs a “Science Research Foundation”, has backed thousands of court cases against Turkish secularists, as a recent report Turkey’s Unnatural Selection in Index on Censorship magazine detailed. Pressure to change the curriculum seems to have ramped up after the failed coup in Turkey in 2016. According to figures from the Turkish Ministry of National Education, the number of religious schools in the country has risen tenfold in the past 10 years, and many children have no other options when it comes to attending a local school.
9-12-18 Is your microbiome making you sick?
Our gut bacteria can play a role in everything from sleep to IBS and how we deal with stress, and we are finally working out how to use them to improve our health. In the last 10 years, interest in the microbiome – the vast colonies of bacteria and other organisms living in our digestive system – has intensified, including its possible role in gut complaints such as irritable bowel syndrome. Studies have shown that the faecal microbiota of people with IBS differs significantly from those of people who don’t have it. Some suggest that a course of antibiotics raises the risk of developing a functional gut disorder like IBS – another hint that an imbalance in gut bacteria might be involved. Some scientists now believe that this imbalance or “dysbiosis” seen in IBS affects the immune and nervous systems, driving people’s symptoms and the way the brain perceives them. An unhealthy microbiome might even play a role in the fact that people with IBS are more prone to certain psychological problems such as stress, which in turn seems to further exacerbate their IBS symptoms. A recent study that transplanted the microbiota of humans with IBS into mice found that the mice showed not only physical symptoms associated with IBS, such as faster transit of food through the gut and an altered immune response, but behavioural ones too, such as anxiety.
9-12-18 The surprising foods that are messing with your gut
We're finally starting to understand which foods are causing tummy troubles for so many, and the culprits challenge everything we thought we knew about healthy eating. SOUTH Beach, paleo, vegan, juice cleanse… and FODMAPs. Short for fermentable oligosaccharides, disaccharides, monosaccharides and polyols, the name FODMAPs certainly doesn’t have instant appeal, but a diet focused on avoiding these substances is catching on with the public and the medical profession alike. The low-FODMAP diet is based not on celebrities’ waistlines or detox bunkum, but on the premise that a healthy gut leads to a happy life. So popular is it proving that there are now claims the diet could alleviate everything from indigestion to chronic fatigue. Over the past few years, we have become much more clued up about the extensive influence of the gut in health and disease, and the impact our lifestyle choices can have on what some researchers like to call our “second brain”. Gluten, a protein found in grains such as wheat, barley and rye, has taken much of the blame, with a growing number of people claiming that they have some sort of gluten intolerance. Global sales of gluten-free food rose 12.6 per cent in 2016, and specialist supermarket aisles now heave with gluten-free products, even though the idea that people can be gluten-sensitive even if they don’t have the autoimmune disorder coeliac disease has been largely debunked. Now the gut health tide is turning once again, and it appears that gut problems linked to certain foods like bread might be real for many. What’s more, the secret to dealing with these problems could fly in the face of established healthy eating advice.
9-12-18 Can a low-carb diet really help shed weight and reverse diabetes?
UK politician Tom Watson has hailed a low-carb diet for his massive weight loss and "reversal" of type 2 diabetes, and now he wants to help tackle the country's obesity crisis. UK politician Tom Watson left a lot of people scratching their heads today when he revealed he has lost 45 kilograms and “reversed” his type 2 diabetes on a low-carb diet. Although it was coupled with an exercise regime, this is not supposed to be a healthy way to eat. What’s going on? Watson’s impressive achievement cuts to the heart of the biggest controversy in nutrition science today. Mainstream medicine says diets should be low in fat and high in starchy carbohydrates such as bread, potatoes and pasta. People should especially shun saturated fat, from red meat and dairy, because this is said to raise cholesterol and so the risk of heart disease. This is the advice from the UK’s National Health Service and in most western countries. According to this orthodoxy, weight depends on the balance between calories in and calories out. If you want to lose weight you have no option but to double down on avoiding fat because it has over twice the calories per gram as the other two main food groups, carbs and protein. If people have a low-fat and low-calorie diet they do lose weight – and if they had type 2 diabetes to start with, their blood sugar levels may well return to normal. But medicine’s dirty secret is that this is not the only method.
9-12-18 A new antibiotic uses sneaky tactics to kill drug-resistant superbugs
The drug will need to go through more testing before it’s used in humans. A new molecule can kill deadly strains of common bacteria, such as Escherichia coli and Klebsiella pneumonia, that are resistant to most existing antibiotics. The drug works differently from currently available antibiotics, potentially making it harder for bacteria to develop resistance, researchers report September 12 in Nature. Most antibiotics kill bacteria by weakening their cell wall or by preventing the production of certain proteins. But bacteria have, over time, evolved ways to circumvent these drugs. And as antibiotics are used frequently in both hospitals and agriculture, resistant bacterial strains are becoming more common. Infections with multidrug-resistant microbes are particularly worrisome, because they can turn usually easy-to-treat illnesses like strep throat or urinary tract infections into deadly ordeals. The newly developed drug uses a different tactic. It inhibits a key enzyme in the cell membrane that helps the bacteria secrete proteins. “We're hitting a new target,” says study coauthor Peter Smith, an infectious disease researcher at Genentech, a biotech company based in South San Francisco, Calif. That means that strategies that bacteria use to evade existing antibiotics won’t work here, giving the molecule an edge.
9-12-18 New breast cancer gene tests will mean hard choices for many women
We are starting to learn more about how gene variants influence the risk of getting breast cancer, but deciding how to use the results raises ethical dilemmas. Imagine being told by a doctor that you have a high risk of breast cancer and that the only way to greatly reduce that risk is to have a double mastectomy. This is the awful choice some women are faced with, most famously Angelina Jolie. But what’s even worse is not to have this choice at all. At present genetic tests can only identify a tiny fraction of the women at high risk, but there’s now a way to identify far more. Deciding what to do about the results, though, will be even harder. The first gene variants linked to breast cancer were identified by studying families with a history of the disease. These families typically had mutations in genes called BRCA1 and BRCA2. These genes code for proteins that help prevent cancer by repairing DNA damage. If either protein is disabled, the risk of breast and ovarian cancers rises greatly. But not all BRCA mutations disable the proteins. Some are completely harmless. The hard part is telling which is which. Most gene variants are rare, and if only a few people in the world have a particular mutation, even studying all of those people would not be enough to tell you what it actually does. So far doctors have studied around 7000 mutations in the BRCA1 gene, yet most are classified as “variants of uncertain significance”.
9-12-18 An antioxidant might lead to new therapies for bone arthritis
An antioxidant commonly sold as a food supplement has been found to limit joint damage in mice with osteoarthritis, and may lead to new treatments for people. An antioxidant food supplement widely used to treat conditions including paracetamol poisoning has shown promise in helping mice with osteoarthritis, the most common joint disorder in the world. The only existing treatments are painkillers and drugs that reduce inflammation, but nothing halts or reverses the condition. When researchers added N-acetyl cysteine, or NAC, to the drinking water they gave to mice with osteoarthritis, it reduced the level of joint damage to that seen in healthy, control mice. The main effect of the NAC was to stifle damage to cartilage tissue in joints, which is caused by a natural process in cells called oxidative stress. Rik Lories of the Catholic University of Leuven in Belgium, and his colleagues screened gene activity in cartilage samples from people and mice with osteoarthritis. They discovered depleted levels of a protein called ANP32A. Further gene-profiling experiments in diseased and healthy joint cartilage cells revealed that ANP32A drives production of a natural enzyme which halts oxidative stress. This suggests oxidative stress in cartilage cells is a key cause of osteoarthritis – and that a therapy to neutralise the problem could treat the condition. Lories and his team decided to find out using NAC – an antioxidant which neutralises oxidative stress. When the researchers bred mice unable to make ANP32A, the animals developed severe osteoarthritis. But treating them with NAC healed their joints, reducing cartilage damage to levels seen in healthy control animals.
9-12-18 Why creating a chemical brain will be how we understand consciousness
Unorthodox chemist Lee Cronin is leading a radical quest to use chemistry to explain consciousness and create artificial life. WHEN Lee Cronin was 9 he was given a Sinclair ZX81 computer and a chemistry set. Unlike most children, Cronin imagined how great it would be if the two things could be combined to make a programmable chemical computer. Now 45 and the Regius Chair of Chemistry at the University of Glasgow, Cronin leads a research team of more than 50 people, but his childhood obsessions remain. He is constructing chemical brains, and has ambitions to create artificial life – using a radical new approach. How far have you got? In my lab I’m creating a physical model of the world in which you have simple rocks and simple organic molecules and then develop a way of getting from there to genetics. I want to understand what the difference is between stuff that is just complicated to make, such as an arrangement of molecules, and stuff that requires information to make, such as basic cellular machinery. We’re looking for molecules that have high molecular weight, that are abundant and that require more information to make them than just a random mess. If we start to see such molecules forming, what does it mean? It can’t be alive according to standard definitions of life, and it’s happening through random chemistry, but if the selected molecules direct the creation of the next, increasingly complex molecules… isn’t that like life? I don’t have proof that this can happen yet, but my guess is that all matter wants to be Darwinian, and we’ll get a selfish molecule that will try to convert all the other molecules to be it.
9-12-18 Iran’s Pompeii: Astounding story of a massacre buried for millennia
The ancient town of Hasanlu was under savage attack when a chance event meant every detail was frozen in time. Finally the story can be told, and the assailants unmasked. THE Iron Age citadel of Hasanlu was grand, with paved streets and palatial homes that rose two, sometimes three, storeys high around columned courtyards. Its people were rich, and lived off fertile lands generously irrigated by Iran’s Lake Urmia. Then they were massacred. The town was destroyed just before 800 BC in a brutal assault. Now, finally, the remarkable story of Hasanlu is being pieced together from artefacts gathered half a century ago. These are revealing a unique snapshot of history. Here, as in the ancient Roman city of Pompeii, time stopped short – only instead of capturing a natural disaster, Hasanlu captures the reality of Iron Age warfare in all its brutal detail. Yet, while everyone knows about Pompeii, few have heard of Hasanlu. That is set to change. In 1956, a young American archaeologist called Robert Dyson travelled to Iran, seeking a site where he could study the origins of sedentary life and farming. He singled out a mound, about 500 metres in diameter and 25 metres high, that stood in a valley at the south end of Lake Urmia. Previous digs had revealed it to be entirely artificial, the result of millennia of dust, dirt and debris building up around a succession of settlements that had occupied the spot starting in 5000 or 6000 BC. It was known locally as Hasanlu.
9-12-18 World’s first drawing is a red crayon doodle made 73,000 years ago
Early humans made red ochre crayon to draw lines on small rock 73,000 years ago. It was probably part of a larger artwork. FROM a cursory glance, the lines on this small, brown stone could be mistaken for a natural formation. In fact, it is the first known drawing ever made by human hands. “This is the beginnings of cultural modernity and sophisticated behaviour,” says Colin Renfrew at the University of Cambridge, who was not involved in its discovery. “You would be astonished if you found another animal species producing something like that. It’s the origins of humankind.” Laboratory analysis shows that the dark red lines, forming a rough, cross-hatched pattern, must have been drawn with a chunk of soft, coloured stone called ochre, possibly one whittled into a simple crayon. Attempts to recreate the pattern using the same materials show that the lines were no careless scrawls but took deliberate effort. “You have to use a lot of pressure and control or it doesn’t leave enough ochre,” says Christopher Henshilwood at the University of the Witwatersrand in Johannesburg, South Africa. Henshilwood and his colleagues dug up the drawing in a South African cave from layers of earth dated to about 73,000 years ago. This makes it nearly twice as old as any previously found Stone Age drawings or paintings by our own species – although it was recently discovered that Neanderthals were painting caves in Spain 64,000 years ago.
9-12-18 This South African cave stone may bear the world’s oldest drawing
The 73,000-year-old line design could have had special meaning for its makers, researchers say. A red, crosshatched design adorning a rock from a South African cave may take the prize as the oldest known drawing. Ancient humans sketched the line pattern around 73,000 years ago by running a chunk of pigment across a smoothed section of stone in Blombos Cave, scientists say. Until now, the earliest drawings dated to roughly 40,000 years ago on cave walls in Europe and Indonesia. The discovery “helps round out the argument that Homo sapiens [at Blombos Cave] behaved essentially like us before 70,000 years ago,” says archaeologist Christopher Henshilwood of the University of Bergen in Norway. His team noticed the ancient drawing while examining thousands of stone fragments and tools excavated in 2011 from cave sediment. Other finds have included 100,000- to 70,000-year-old pigment chunks engraved with crosshatched and line designs (SN Online: 6/12/09), 100,000-year-old abalone shells containing remnants of a pigment-infused paint (SN: 11/19/11, p. 16) and shell beads from around the same time. The faded pattern consists of six upward-oriented lines crossed at an angle by three slightly curved lines, the researchers report online September 12 in Nature. Microscopic and chemical analyses showed that the lines were composed of a reddish, earthy pigment known as ocher.
9-12-18 'Oldest known drawing' found on tiny rock in South Africa
Scientists say they have discovered humanity's oldest known drawing on a small fragment of rock in South Africa. The drawing is about 73,000 years old, and shows cross-hatch lines sketched onto stone with red ochre pigment. Scientists discovered the small fragment of the drawing - which some say looks a bit like a hashtag - in Blombos Cave on the southern coast. The find is "a prime indicator of modern cognition" in our species, the report says. While scientists have found older engravings around the world, research published on Wednesday in the journal Nature says the lines on this stone mark the first abstract drawing. The article says the ancient artist used an "ochre crayon" to etch it onto the stone. Humanity has used ochre, a clay earth pigment, for at least 285,000 years. The drawing was "probably more complex" in its entirety, archaeologist Christopher Henshilwood told Reuters. "The abrupt termination of all lines on the fragment edges indicates that the pattern originally extended over a larger surface," he said.
9-12-18 You should soothe babies who wake at night – it speeds sleep training
Parents may be told to let babies “cry it out” if they wake at night – but comforting very young infants who wake helps them develop a better night-time routine. When an ear-piercing cry shatters a peaceful night, go ahead and pick the baby up. Comforting an infant under three-months of age can help reduce their tendency to wake up at night as they grow older. Beyond the three-month mark, though, parents’ interventions may have little impact on a baby’s sleeping habits. It takes time for babies to learn to sleep through the night. To better understand parents’ role in the process, Sabrina Voltaire at Pennsylvania State University in University Park, and her colleagues, followed 107 families with newborns for nine months. Each family recorded the baby’s night waking frequency daily for one week before the child was three months, six months and nine months old. Researchers also installed cameras in families’ bedrooms for one night during the reporting week to observe parents’ interventions when babies woke up and cried. Voltaire found the babies whose parents responded promptly to their night wakings before they turned three months old experienced a faster decline in their tendency to wake at night. But after the first three months, babies showed a similar pace of sleep development whether or not parents intervened when they woke. The findings contradict the popular “cry it out” approach – letting babies cry until they fall back to sleep. Many parenting books recommend this method under the assumption that prompt intervention when a baby cries at night may encourage infants to keep waking up. “Such an assumption could not be substantiated in this study,” Voltaire and her colleagues write.
9-11-18 Volcanic eruption may have helped drive real-life hobbits extinct
The diminutive Homo floresiensis died out about 50,000 years ago just as a volcano exploded – but are the two connected or was extinction down to other factors?. About 50,000 years ago on the Indonesian island of Flores, all the large animals disappeared at once. The losses included dwarf elephants, carnivorous birds – and a species of diminutive hominin known as the “hobbit”, or Homo floresiensis. It’s not clear why. A volcano erupted, and the climate was shifting. But there is also tentative evidence that there was a new threat on the island: modern humans. Hobbits were first described in 2004, after bones were found in the Liang Bua cave on Flores. They stood 1 metre tall and had brains the size of grapefruit. Initially it seemed that the hobbits had survived until as recently as 13,000 years ago – suggesting they lived alongside modern humans for tens of thousands of years. However, in 2016 researchers led by Thomas Sutikna of the University of Wollongong, Australia reassessed the dating evidence. They found the youngest traces of the hobbits’ existence are actually 50,000 years old, implying that’s when they disappeared. Now Sutikna and his colleagues have dated other material from Liang Bua, revealing how the local ecosystem was changing. They examined over 300,000 animal remains and 10,000 stone tool fragments, found in sediments laid down over 190,000 years. “This is a huge dataset,” says research team member Matthew Tocheri of Lakehead University in Ontario, Canada. Before 50,000 years ago, Flores was dominated by dwarf elephants (Stegodon florensis insularis) the size of a large cow. “There’s no doubt that this is the largest animal alive on Flores during this time,” says Tocheri.
9-10-18 Genetic studies intend to help people with autism, not wipe them out
There are fears genetics research into autism will lead to eugenics and eradication of the condition. That must never come to pass, says Simon Baron-Cohen. Genetics plays a large role in causing autism, so knowing more about which genes influence it could allow a better understanding of the condition. It is a rapidly unfolding area of research, but there is a problem. As director of the University of Cambridge’s Autism Research Centre, I am increasingly aware that more and more autistic people don’t want to take part in genetics studies. It seems to be happening because of a fear that the agenda is eugenics – find the genes to identify potentially autistic babies in pregnancy, and terminate such pregnancies. These fears are understandable if we look at how this has happened in the case of Down’s syndrome. Some people also worry that genetics research will lead to genetic engineering to “normalise” autistic people. Again, I would be horrified at this application of science, because it doesn’t respect that people with autism are neurologically different, and like any other kinds of diversity (such as hair, skin or eye colour, handedness, or sexual orientation) should be accepted for who they are. My colleagues and I are opposed to any form of eugenics. The worry though is that if people equate autism genetics with a eugenics agenda, valuable progress on autism genetics could be slowed down. Today, autism is known to be strongly genetic, with heritability estimated at between 60 and 90 per cent. Autism is not 100 per cent genetic – if one identical twin has autism their co-twin doesn’t always have it. The obvious conclusion is that a genetic predisposition interacts with environmental factors.
9-10-18 We’ve cracked the brain’s emotion code and it may help depression
Eavesdropping on someone’s mood in real time is a major first step towards permanent brain implants to both detect and treat depression. Patterns of electrical brain activity have been used for the first time to tell when people are sad, happy or depressed. It’s a first step towards treating people with depression or anxiety with devices which would constantly monitor their mood using brain signals. Ultimately, the aim is to programme the devices so they actually help people overcome potentially dangerous negative emotions in real time by activating other, more uplifting networks in the brain. Already, brain implants are helping people who are “locked-in” or paralysed communicate with caregivers and friends through computer interfaces. And by implanting and activating electrodes in specific regions of people’s brains – a process called deep brain stimulation, or DBS – researchers have helped to ease a range of conditions including depression, bipolar disorder, Tourette’s syndrome and obsessive compulsive disorder. There are even advances towards “mind-reading” – deciphering memories and internal thoughts by monitoring the brain’s electrical activity. Now it’s possible to capture mood too. “We’ve discovered how mood variations can be decoded from neural signals in the human brain,” says lead researcher on the project, Maryam Shanechi of the University of Southern California in Los Angeles. “It’s a significant step towards creating new therapies that use brain stimulation to treat debilitating mood and anxiety disorders in millions of patients who don’t respond to current treatments.” In the US alone, the 2016 National Survey on Drug Use and Health revealed that 16.2 million adults experienced depressive episodes the previous year – almost 7 per cent of the US population – but a third didn’t respond to treatment.
9-10-18 How obesity may harm memory and learning
In obese mice, rogue immune cells chomp nerve cell connections. Obesity can affect brainpower, and a study in mice may help explain how. In the brains of obese mice, rogue immune cells chomp nerve cell connections that are important for learning and memory, scientists report September 10 in the Journal of Neuroscience. Drugs that stop this synapse destruction may ultimately prove useful for protecting the brain against the immune cell assault. Like people, mice that eat lots of fat quickly pack on pounds. After 12 weeks of a high-fat diet, mice weighed almost 40 percent more than mice fed standard chow. These obese mice showed signs of diminished brainpower, neuroscientist Elizabeth Gould of Princeton University and colleagues found. Obese mice were worse at escaping mazes and remembering an object’s location than mice of a normal weight. On nerve cells, microscopic knobs called dendritic spines receive signals. Compared with normal-sized mice, obese mice had fewer dendritic spines in several parts of the mice’s hippocampi, brain structures important for learning and memory. The dendritic spine destruction comes from immune cells called microglia, the results suggest. In obese mice, higher numbers of active microglia lurked among these sparser nerve cell connections compared with mice of normal weights. When the researchers interfered with microglia in obese mice, dendritic spines were protected and the mice’s performance on thinking tests improved.
9-9-18 How we define life is changing
If we make it in a lab, is it still alive? What is life? For much of the 20th century, this question did not particularly concern biologists. Life is a term for poets, not scientists, argued the synthetic biologist Andrew Ellington in 2008, who began his career studying how life began. Despite Ellington's reservations, the related fields of origins-of-life research and astrobiology have renewed focus on the meaning of life. To recognize the different form that life might have taken four billion years ago, or the shape it could take on other planets, researchers need to understand what, in essence, makes something alive. Life, however, is a moving target, as philosophers have long observed. Aristotle distinguished "life" as a concept from "the living" — the collection of existing beings that make up our world, such as the neighbor's dog, my cousin, and the bacteria growing in your sink. To know life, we must study the living; but "the living" is always changing across time and space. In trying to define life, we must consider the life we know and the life we don't know. As the origins-of-life researcher Pier Luigi Luisi at Roma Tre University puts it, there is life-as-it-is-now, life-as-it-could-be, and life-as-it-once-was. These categories point to a dilemma that medieval mystical philosophers addressed. Life, they noticed, is always more than the living, making it, paradoxically, permanently inaccessible to the living. Because of this gap between actual life and potential life, many definitions of life focus on its capacity to change and evolve rather than trying to pin down fixed characteristics. In the early 1990s while advising NASA on the possibilities of life on other planets, the biologist Gerald Joyce, now at the Salk Institute for Biological Studies in California, helped to come up with one of the most widely used definitions of life. It's known as the chemical Darwinian definition: "Life is a self-sustained chemical system capable of undergoing Darwinian evolution." In 2009, after decades of work, Joyce's group published a paper in which they described an RNA molecule that could catalyze its own synthesis reaction to make more copies of itself. This chemical system met Joyce's definition of life. But nobody wanted to claim that it was alive. The problem was, it hadn't done anything new or exciting yet. A New York Times article put it this way: "Someday their genome may surprise their creator with a word — a trick or a new move in the game of almost life — that he has not anticipated. 'If it would happen, if it would do it for me, I would be happy,' Dr. Joyce said, adding, 'I won't say it out loud, but it's alive.'"
9-8-18 How empathy can lead to cruelty
Can you be bad for another person's good?. Imagine that someone you care about is procrastinating in advance of a vital exam. If he fails the test, he will not be able to go to university, an eventuality of major consequence in his life. If positive encouragement doesn't work, you might reverse strategy, making your friend feel so bad, so worried, so scared, that the only strategy left is that he starts studying like mad. Sometimes, the only way to help someone seems to be a cruel or nasty approach — a strategy that may leave the "helper" feeling guilty and wrong. Now, research from my team at the Liverpool Hope University in the U.K. sheds light on how the process works. We typically equate positive emotions with positive consequences, and there's research to back that up. Numerous studies of interpersonal emotion regulation — how one person can change or influence the emotions of another — emphasize the value of increasing positive emotions and decreasing negative ones. Other studies show that making someone feel badly can be useful: Anger is helpful when confronting a cheater, and hurting another's feelings can give them an edge in a game. Now, my team has documented the routine use of cruelty for altruistic reasons. To validate the phenomenon, we hypothesized the need for three conditions: The motivation to worsen someone's mood needs to be altruistic; the negative emotion inflicted on the other person should help them achieve a specific goal; and the person inflicting the pain must feel empathy for the recipient.
9-7-18 How much alcohol is safe?
In a hotly disputed finding, a major global study has concluded that there is no “safe” level of alcohol consumption, and that even the occasional drink can be harmful to your health. The Global Burden of Disease Study examined data on drinking in 195 countries between 1990 and 2016, focusing on how consumption affected risk for 23 different alcohol-related issues. The researchers found that even as little as one drink a day over a year slightly increased the incidence of health problems. A low level of alcohol use does seem to provide some protection against heart disease and diabetes, researchers acknowledged, but those benefits are outweighed by other impacts. But the study’s methods sparked widespread skepticism, reports The New York Times. The researchers weren’t able to control for possible confounding factors: People who drink may be more likely to smoke, for example. Many researchers argue that recommending zero alcohol consumption is unrealistic and unhelpful. “Claiming there is no ‘safe’ level does not seem an argument for abstention,” says David Spiegelhalter, a statistician at Cambridge University. “There is no safe level of driving, but governments do not recommend that people avoid driving.”
9-7-18 The risks of e-cigarettes
People who use e-cigarettes daily may be significantly increasing their risk of a heart attack, reports ScienceDaily.com. Scientists examined data from two national surveys with a combined 69,000 respondents. They found that compared with people who never had e-cigarettes, daily users were twice as likely to have a heart attack. That’s still an improvement on conventional cigarettes, which almost triple the risk of an attack. But more than two thirds of the e-cigarette users were also conventional smokers—and their risk was five times higher than that of nonsmokers. “Vaping” delivers a powerful dose of nicotine, which has a proven negative impact on heart health. The study did offer some good news for e-cigarette users: The risk of a heart attack starts to drop as soon as they stop, as it does for conventional cigarettes.
9-7-18 Social sciences findings shaky
The reliability of social science studies has been thrown into question, after an attempt to replicate 21 high-profile experiments yielded only 13 successful reproductions. The two-year research project centered on studies that were published between 2010 and 2015 in the highly respected journals Science and Nature. For a scientific finding to be valid, other scientists should be able to get the same result. But in many cases, the project found, researchers in the original study had a bias toward proving their theory and tended to find false positives. One example was the finding, published in 2011 and widely covered in the media, that people struggle to remember information that they think they can find online. A repeat of the experiment, however, found no such “Google effect.” Even in the successful replications of other studies, the observed effect was on average only about 75 percent as great as in the original. The journals said their publication standards had been tightened since the studies in question were published, and called for more replication projects. “You can say, ‘Oh, this is terrible, it didn’t replicate,’” Science deputy editor emeritus Barbara Jasny tells The Washington Post. “Or you could say, ‘This is the way science works. It evolves. People do more studies.’” Scientists themselves actually appear to have a good nose for flawed studies. When the researchers asked some 200 of their peers to predict which findings were suspicious, they largely guessed right.
9-6-18 Probiotics are mostly useless and can actually hurt you
Supplements of “friendly” bacteria often don’t improve our gut microbiota and can be harmful after antibiotics, according to the most in-depth study yet. Probiotics are living micro-organisms that are taken by millions of people to boost their microbiome or to restore their gut ecosystem after a dose of antibiotics. Yet questions remain about whether they actually work. To find out what really goes on in the gut when people ingest probiotics, immunologist Eran Elinav of the Weizmann Institute of Science in Israel, and colleagues, sampled the microbiome of healthy volunteers directly using endoscopies and colonoscopies. Most other microbiome research relies on faecal samples as a proxy for gut microbes. They then fed 15 of the volunteers either a commercially available probiotic supplement or a placebo. The outcome was striking. For a start, the microbes found in faeces were not representative of those that had colonised the gut. “Relying on faecal samples as an indicator of what goes on inside the gut is inaccurate and wrong” says Elinav. The research also showed that while probiotics colonised the gastrointestinal tract of some people, the gut microbiome of others just expelled them. There was no way of telling from their stool sample which category people fell into. “Some people accept probiotics in their gut, while others just pass them from one end to the other,” says Elinav. They found that the probiotic colonisation patterns were highly dependent on the individual. That tells us that the concept that everyone can benefit from a universal probiotic bought from the supermarket is empirically wrong, he says.
9-5-18 The ‘me’ illusion: How your brain conjures up your sense of self
Self-awareness isn't the pinnacle of consciousness - it's just an accidental byproduct of evolution, and a figment of our minds. LOOK into a mirror and you may see pimples, wrinkles or unruly facial hair, but beneath the superficial lies something far more interesting. Every time you lock eyes with your reflection, you know exactly who is looking back at you. The sense of self is unmistakable. It is so much a part of being human that we often fail to notice it. Yet self-awareness is one of the biggest mysteries of the mind. How did it arise and what is it for? Looking at other animals suggests we are not alone in being able to recognise ourselves in a mirror. Admittedly, it’s a short list of species that seem capable of this feat, but it hints at a possible explanation. Self-awareness may have evolved in only the brightest animals with the biggest brains. If so, it represents the peak of mental complexity – the highest form of consciousness. However, some people have started to question this idea. Now, an extraordinary finding lends weight to their scepticism: one monkey species that was previously deemed unable to recognise itself in a mirror can easily learn to do so. This isn’t simply another name to add to the echelons of the self-aware. The discovery suggests we need to fundamentally rethink our ideas about mirrors and minds. The hunt for self-awareness among non-humans has been going on for decades. In the most widely used test – the so-called face-mark test – researchers stealthily apply a spot of odourless dye to an animal’s forehead or cheek and then observe its reaction when it is in front of a mirror. The underlying premise is that those with a firm sense of self can acknowledge their reflection and attempt to scrub off the dye.
9-5-18 A huge water-powered factory helped make food for Roman sailors
A site in France is home to the biggest ancient watermill complex ever found, and the flour it milled may have been used to make ship biscuits. It was once thought that watermills only began to be used on an industrial scale in medieval times. But in 1937 a Roman complex with 16 water wheels was found in Barbegal in southern France – the largest ancient water-powered factory found anywhere in the world. Now it has been shown that the Barbegal factory probably specialised in producing flour for making ship biscuits, rather than for supplying the nearby Roman city of Arelate as previously assumed. During excavations of the site in 1937 archaeologists discovered thick limescale deposits that had built up on the wooden wheels as they churned through the water. “They have impressions of the woodwork,” says geologist Cees Passchier of the Johannes Gutenberg University in Germany. “The wood itself has rotted away.” His team’s isotopic analyses show the limescale was not deposited continuously throughout the year and suggests the mills stopped operating in late summer and autumn. This doesn’t make sense if the mills were producing flour for normal use. Flour was milled throughout the year as needed, because it does not store as well as grain. “For a major city you need a supply all year round,” says Passchier. Roman shipping was strongly seasonal, though, with few ships sailing the Mediterranean in winter because of the risk of storms. So the archaeologists on the team think the mill complex was used from winter to late summer to produce flour for the nearby ports of Arles and Fossae Marianae. There it would have been double baked to create long-lasting ship biscuits similar to the “hardtack” used in later times.
9-5-18 German skeletons hint that medieval warrior groups recruited from afar
DNA analyses of European graveyard finds are shedding new light on the Frankish Empire. Power systems transcended kinship in medieval Europe. A burial site in southern Germany contains members of a powerful warrior family who journeyed widely to find recruits to join the household and support a post-Roman kingdom, a new study suggests. Thirteen individuals interred at Niederstotzingen belonged to the Alemanni, a confederation of Germanic tribes that were conquered by and integrated into a neighboring kingdom of the Frankish people starting around 1,400 years ago, researchers say. Excavations in 1962 revealed the bodies, which the team estimates were buried from roughly 580 to 630, along with various weapons, armor, jewelry, bridle gear and the remains of three horses. DNA extracted from the German skeletons identified 11 as probably males, biomolecular archaeologist Niall O’Sullivan of Eurac Research’s Institute for Mummy Studies in Bolzano, Italy, and colleagues report online September 5 in Science Advances. Six skeletons displayed genetic ties to modern northern and eastern Europeans. All but one of those six were closely related, including a father and two of his sons. Chemical analyses of tooth enamel, which provides regional signals of early childhood diet, indicated that these individuals grew up near Niederstotzingen. Artifacts from three foreign medieval European cultures lay in the graves of four local males. Weapons and other objects typical of the Franks accompanied one man — the previously mentioned father — who may have headed the power household, the researchers suspect.
9-4-18 Your brain power varies throughout the year, peaking in autumn
Adults in temperate regions of the Northern Hemisphere perform better in cognitive tests in early autumn, and dementia symptoms peak in winter and spring. Human cognitive powers have a seasonal rhythm, and for those living in temperate regions in the northern hemisphere they are strongest in late summer and early autumn. The effect is large enough to tip some older people over the diagnostic threshold for dementia if their cognitive tests are carried out in winter or spring. Andrew Lim, a neurologist at the Sunnybrook Health Sciences Centre at the University of Toronto, and his colleagues analysed data from 3500 participants aged 60 or over. All of them had undergone tests of their thinking and concentration skills as part of independent studies – conducted in the US, Canada and France. For some participants, the researchers also looked at levels of proteins associated with Alzheimer’s disease. A previous study led by Lim had found a seasonal pattern in gene expression in the human brain. “We wanted to build on this, to see whether this was having a real effect on patients at the clinical level,” says Lim. The researchers found a strong seasonal trend in both cognitive performance and Alzheimer’s biomarkers, which was independent of confounding factors such as depression, sleep and physical activity. “We found a peak in cognitive performance near the Fall equinox, at the end of summer,” says Lim. The effect was strong enough to make a participant seem nearly five years younger, in terms of age-related cognitive decline, compared to if they were tested in winter or spring.
9-4-18 Can an online test really tell if you have a healthy heart?
Public Health England has launched an online “heart-age” test to reveal people’s risk of heart attack or stroke, but it may be overly simplistic. Health chiefs in England this week launched an online “heart-age” test, which is claimed to reveal people’s risk of a heart attack or stroke. Public Health England (PHE) says that if a person’s heart is “older” than their age, they are at increased risk and should consider diet and lifestyle changes. But critics say the test —which asks simple physical and lifestyle questions – could create unfounded alarm by basing estimates on incomplete data. PHE says that of 1.9 million who have already tried the test, 78 per cent had hearts older than their age. Just over a third had hearts five years older than themselves, and 14 per cent had hearts 10 years older. It asks for accurate measurements of blood pressure and cholesterol, for example, but if these are not available, it inserts average values for the UK population, which tend to be on the unhealthy side. A healthy adult has total blood cholesterol levels of 5 millimoles per litre of blood, for example, but the average is higher and unhealthier, at 5.7 millimoles. This “default” input could potentially mislead users by falsely inflating—or deflating—someone’s estimates of risk and heart age. A similar controversy arose after 2013 when the US American College of Cardiology launched an online algorithm by which doctors could estimate their risk of a heart attack or stroke in the coming decade.
9-4-18 Huge ‘word gap’ holding back low-income children may not exist after all
A study contests the idea that poor kids hear fewer words than kids from higher-income families. A scientific takedown of a famous finding known as the 30-million-word gap may upend popular notions of how kids learn vocabulary. Research conducted more than 20 years ago concluded that by age 4, poor children hear an average of 30 million fewer words than their well-off peers. Since then, many researchers have accepted the reported word gap as a driver of later reading and writing problems among low-income youngsters. A Providence, R.I., program inspired by the study, for example, now teaches poor parents how to talk more with their kids. But here’s the rap on the word gap: It doesn’t exist, says a team led by psychologist Douglas Sperry of Saint Mary-of-the-Woods College in Indiana. In a redo of the original study, virtually no class differences appeared in the number of words addressed to young children by a primary caregiver, Sperry and colleagues report in a study to be published in Child Development. What’s more, after including speech spoken directly to children by various caretakers as well as family members’ conversations that the youngsters could easily overhear, kids in some poor and working-class communities heard more words on average than middle-class youngsters, the scientists say. Within each of those communities, some children heard many more words than others did despite belonging to the same social class, Sperry’s team adds.
9-3-18 ‘Invisible’ Ebola transmission in the DRC may make it a bigger threat
An outbreak of Ebola in the Democratic Republic of the Congo has killed 78 people and epidemic watchers are waiting to see whether it can be controlled. The world’s epidemic watchers are holding their breath this week. The latest Ebola outbreak in the Democratic Republic of the Congo seems to be subsiding, after striking 120 people and killing 78 as of 1 September. But Tedros Ghebreyesus, head of the World Health Organization, has warned that the coming days will be critical. That is partly because the outbreak is in North Kivu province in the war-torn northeast of the DRC, where fighting by more than 50 armed groups puts many areas off limits. To stop the virus spreading, medical teams must isolate and vaccinate anyone who has had contact with an infected person, and do the same for all the people they in turn contacted. But, says the WHO, the teams can’t work much more than 30 kilometres from the epidemic’s centre in Beni. Worse, the UN’s International Organisation for Migration has found that people in the region are highly mobile, with traders and miners transiting to Uganda and Rwanda, and a million displaced by violence. Such high population mobility, plus a slow medical response, caused a local Ebola outbreak in West Africa to mushroom into an unprecedented epidemic that killed more than 11,000 in 2014. This time the response has not been slow. The outbreak was recognised on 1 August, only a week after an Ebola epidemic on the other side of the DRC had been halted. A week later teams in North Kivu were vaccinating contacts. This selective “ring vaccination” of the contacts of known cases, then their contacts, makes best use of limited vaccine stocks by containing virus spreading from known cases.
9-1-18 Struggling to multitask? Your brain might have hit full capacity
When people are trying to do several things at once their brain cells freeze up when yet another task is added to the pile. Ever felt like you’re struggling to think about too many things at once? That might be because your brain’s attention systems are full. A new brain-scanning method that shows how much energy nerve cells are using has provided more support for the idea that we only have a finite amount of attention available. The findings also help explain the bizarre “invisible gorilla” optical illusion. In this, people watching a staged video can completely fail to see a man in a gorilla suit taking a leisurely stroll through a group of actors because they’re too busy concentrating on what the actors are doing. How we pay attention to only certain aspects of the torrents of information produced by our senses is one of the many mysteries of consciousness. Nilli Lavie at University College London has proposed that our brains only have a finite amount of attention, and that when that capacity is reached, we start ignoring other things. Her group has previously found support for this idea by doing fMRI brain scans of people as they did mental tasks of increasing difficulty. Although fMRI brain scans have become a mainstay of neuroscience research, they have drawbacks. They require people to lie inside a huge machine, and the scans can’t directly measure the activity of nerve cells; instead they provide an indirect measure by showing which parts of the brain are using the most oxygen and so are likely to be at work.