5-31-19 Sea creature uses stem cells to regrow entire body from a tiny piece
Marine animals called sea squirts can regenerate their entire bodies from nothing but a tiny fragment of a blood vessel. Their secret is a special population of stem cells floating in their blood. The finding could help us understand how such regenerative abilities evolved. In the long run, it could also help doctors regenerate damaged or lost tissues or even limbs in our own bodies. Sea squirts are oval or cylindrical animals a few centimetres across. They belong to a larger group of animals called the chordates, most of which are backboned vertebrates, such as fish, birds and humans. That means sea squirts are our closest living non-backboned invertebrate relatives. In 2007, researchers found that one sea squirt, Botrylloides leachii, can regrow its body from a fragment of a blood vessel. “But no one had done any in-depth studies showing which cells give rise to the new body that is being made,” says Susannah Kassmer at the University of California, Santa Barbara. She and her colleagues studied the cells in separated fragments of blood vessels as they regenerated, and found a population of cells that expressed genes known to be involved in this process. Destroying the cells halted regeneration, while adding just one restarted it. Kassmer calls the cells “Primordial Blasts”. They are stem cells, meaning they can grow into a variety of different tissues. It isn’t yet clear if they are pluripotent, meaning they can form any kind of cell, but Kassmer says it is likely that at least some of them are. Many more primitive invertebrates, such as certain jellyfish and flatworms, can regenerate their bodies from fragments. But vertebrates cannot: at most, they can regrow a lost limb, as some salamanders do.
5-31-19 Cave debris may be the oldest known example of people eating starch
Charred material found in South Africa suggests humans digested starch long before farming. Small fire pits in a South African cave have yielded what researchers regard as the oldest known examples of a key dish in ancient humans’ daily menu. No, not dessert. Think roasted plant starches. Charred plant remains found in Klasies River Cave date to as early as around 120,000 years ago, and as late as roughly 65,000 years ago, say archaeologist Cynthia Larbey of the University of Cambridge in England and her colleagues. The organic fragments contain starch granules, but can’t be linked to any known starchy plant species, the team reports in the June Journal of Human Evolution. Based on plants that would have been locally available, Stone Age people likely cooked tubers and roots in the cave, the scientists say. Compared with raw starchy plants, their cooked counterparts would have provided an especially efficient source of glucose, and thus energy, to people. Human fossils previously found in the coastal cave, located at Africa’s southern tip, also date to around 120,000 years ago. Ancient starch eating at Klasies River Cave supports the possibility that Homo sapiens evolved genetic upgrades to help with digesting hard-to-break-down starch long before people started farming starchy crops in Africa around 10,000 years ago. Scientists have determined that people today carry more copies of starch-digestion genes than did Stone Age populations, such as Neandertals and Denisovans.
5-31-19 Fossils reveal saber-toothed cats may have pierced rivals’ skulls
The curved canine of one ancient cat fits precisely into a hole left in the skull of another. Saber-toothed cats may sometimes have wielded their formidable canine teeth as deadly weapons to puncture the skulls of rival cats. It was already suspected that Smilodon cats used their huge canines to take down prey, perhaps by ripping out the prey’s throat (SN: 3/30/19, p. 20). But some researchers argued that the daggerlike teeth, which could grow up to 28 centimeters long in the largest species, were too thin and fragile to puncture bone without breaking. But a new analysis of two skulls from Smilodon populator, a saber-toothed cat species that prowled what is now South America, contests that idea, says a team of Argentinian researchers led by Nicolás Chimento. Large puncture holes in the top of the fossil skulls match the size and shape of canines of saber-toothed cats, the researchers report online in the May Comptes Rendus Palevol. Similar injuries are sometimes seen in the skulls of living cats, such as leopards, jaguars and cheetahs, the authors write. “Smilodon canines were strong enough to penetrate bone and were formidable hunting weapons,” says Chimento, a paleontologist at the Bernardino Rivadavia Argentine Natural Science Museum in Buenos Aires. The skull wounds were probably made during tussles while “fighting for territoriality, access to females or food.”
5-31-19 GM fungus rapidly kills 99% of malaria mosquitoes, study suggests
A fungus - genetically enhanced to produce spider toxin - can rapidly kill huge numbers of the mosquitoes that spread malaria, a study suggests. Trials, which took place in Burkina Faso, showed mosquito populations collapsed by 99% within 45 days. The researchers say their aim is not to make the insects extinct but to help stop the spread of malaria. The disease, which is spread when female mosquitoes drink blood, kills more than 400,000 people per year. Worldwide, there are about 219 million cases of malaria each year. Conducting the study, researchers at the University of Maryland in the US - and the IRSS research institute in Burkina Faso - first identified a fungus called Metarhizium pingshaense, which naturally infects the Anopheles mosquitoes that spread malaria. The next stage was to enhance the fungus. "They're very malleable, you can genetically engineer them very easily," Prof Raymond St Leger, from the University of Maryland, told BBC News. They turned to a toxin found in the venom of a species of funnel-web spider in Australia. The genetic instructions for making the toxin were added to the fungus's own genetic code so it would start making the toxin once it was inside a mosquito. "A spider uses its fangs to pierce the skin of insects and inject toxins, we replaced the fangs of spider with Metarhizium," Prof St Leger explained. Laboratory tests showed the genetically modified fungus could kill quicker, and that it took fewer fungal spores to do the job. The next step was to test the fungus in as close to real-world conditions as possible. A 6,500-sq-ft fake village - complete with plants, huts, water sources and food for the mosquitoes - was set up in Burkina Faso. It was surrounded by a double layer of mosquito netting to prevent anything escaping.
5-30-19 A fungus weaponized with a spider toxin can kill malaria mosquitoes
In field trials, genetically engineered Metarhizium pingshaense reduced numbers of the insects. A fungus engineered to produce a spider toxin could help take down insecticide-resistant mosquitoes that can spread malaria. In a netted, outdoor experiment in Burkina Faso, the genetically engineered fungus wiped out mosquito populations within two generations, researchers report in the May 31 Science. If the result holds up in a real-world situation, the modified fungus may one day become a tool for controlling mosquitoes that can transmit the deadly disease. In 2017, an estimated 219 million people in 87 countries were infected with malaria, and 435,000 died, according to the World Health Organization. Africa carried most of the malaria burden, with 92 percent of cases and 93 percent of deaths occurring on the continent that year. The fungus Metarhizium pingshaense, long known to infect and kill mosquitoes, was made even deadlier to the insects by the addition of a gene that produces a spider bite toxin called Hybrid. Researchers engineered the fungus to make Hybrid in the presence of the mosquito version of blood, called hemolymph. “We’re just bypassing the spider fangs and getting the fungus to do the same job,” says study coauthor Raymond St. Leger, an entomologist at the University of Maryland in College Park. In laboratory trials in 2011, engineered fungi related to M. pingshaense infected and killed mosquitoes and their malaria parasites (SN Online: 2/25/11). (The fungi don’t harm people, other insects or animals.) “That’s all well and good, but what happens in the lab doesn’t necessarily translate into field conditions,” says study coauthor Brian
5-30-19 Measles record means US could lose eradication status
The number of US measles patients has reached a record high and may cause the nation to lose its "measles elimination status", US health officials say. Sixty new cases were reported in the past week, bringing this year's total to 971 cases in 26 US states - the highest since 1994. The disease was declared effectively eliminated from the US in 2000. Recent outbreaks have been attributed to foreign travellers spreading it to those lacking vaccinations in the US. The US Centers for Disease Control and Prevention (CDC) said in a statement on Thursday: "If these outbreaks continue through summer and fall, the United States may lose its measles elimination status. "That loss would be a huge blow for the nation and erase the hard work done by all levels of public health. "The measles elimination goal, first announced in 1963 and accomplished in 2000, was a monumental task." The statement added that previously between three and four million Americans were diagnosed with the sometimes-fatal illness each year, leading to an estimated 400-500 deaths and 48,000 hospitalisations. Earlier this year, Anthony Fauci of the National Institute of Allergy and Infectious Diseases testified to lawmakers that more must be done to prevent the spread of the disease. "I consider it an irony that you have one of the most contagious viruses known to man juxtaposed against one of the most effective vaccines they have," he said. "Yet we don't do and have not done what could be done - namely eliminate, eradicate the virus." This year's tally of 971 means the US has already broken the 1994 record - 963 infections - in only the first five months of 2019.
5-30-19 A type of African mole rat is immune to the pain caused by wasabi
If you hate wasabi-flavoured snacks, you are not alone. All things in the animal kingdom, down to worms and flies, naturally avoid allyl isothiocyanate (AITC), the compound responsible for wasabi’s pungent taste. But now researchers have discovered the first species immune to the burning pain caused by exposure to AITC, raising the prospect of new pain relief in humans and boosting our knowledge of evolution. The highveld mole rat (Cryptomys hottentotus pretoriae), which lives in the east of South Africa, proved completely insensitive to AITC when it was injected in its paw. The reason appears to be the similarity of AITC to the sting of the aggressive Natal droptail ant, which often live in the rats’ burrows. An international team concludes that over millions of years, the rat has developed a particularly high expression for a gene that blocked the channel through which it would feel pain from AITC. That immunity gives the highvelds an advantage over other African mole rat species, allowing them to survive in areas others would not enter because of their sensitivity to the ant’s sting. “Evolution over millions of years works like a blind watchmaker, of how to fix the problem,” says Gary Lewin of the Max Delbrück Center for Molecular Medicine, Germany. When his team used drugs to block the ‘short circuit’ protecting the rats from feeling the burn from AITC, they did react to the pain. The understanding of the genetic mechanism for turning off pain perception could help people in future too. “This could help develop a therapy to shut down pain in humans,” says Lewin. The rats are related to the ugly but exceptional naked mole-rat, which for years has been known to be immune to the pain caused by acid.
5-30-19 Africa’s first herders spread pastoralism by mating with foragers
Crossbreeding, not just cultural influences, led hunter-gatherers to adopt livestock practices. Ancient sheep, goat and cattle herders made Africa their home by hooking up with the continent’s native hunter-gatherers, a study suggests. DNA analysis shows that African herders and foragers mated with each other in two phases, says a team led by archaeologist Mary Prendergast of Saint Louis University in Madrid. After entering northeastern Africa from the Middle East around 8,000 years ago, herders swapped DNA with native foragers between roughly 6,000 and 5,000 years ago. Herders possessing some forager heritage then trekked about halfway down the continent and mated with eastern African foragers around 4,000 years ago, the scientists report online May 30 in Science. Present-day herders, such as the Dinka in South Sudan, still live in eastern Africa. But how pastoralism spread into the region has been a mystery. In particular, it has been difficult to tell whether ancient African hunter-gatherers mated with early herders or simply adopted their livestock practices. The new study supports an emerging view from ancient DNA studies that human cultural evolution has often featured mating across groups with different traditions and lifestyles. Prendergast and her colleagues analyzed tooth and bone DNA from 41 individuals whose remains were previously found at herding and foraging sites in Kenya and Tanzania with ages ranging between about 4,000 and 100 years old.
5-30-19 Vaping the sweetener sucralose may produce toxic chemicals
The synthetic sweetener’s breakdown produces harmful organochlorines and increases amounts of toxic aldehydes. Lacing e-cigarette liquid with sucralose is probably not a sweet idea. Vaping the synthetic sweetener may generate harmful chemicals, researchers report May 13 in Chemical Research in Toxicology. “I would strongly advise that users should not use liquids with sucralose in them,” says Sven Jordt, a toxicologist at Duke University School of Medicine who was not involved with the study. Many e-cigarette users, especially teenagers (SN: 12/22/18, p. 28), are drawn to sweet and fruity flavored e-liquids. But because of lax labeling rules, it’s not clear which e-cigarettes include sucralose and how much they contain. The popular Juul brand does not contain sucralose, Jordt says. Manufacturers also sell concentrated sucralose solutions for users who mix their own e-juice. Sucralose, sold under the brand name Splenda for use in food and drink, is hundreds of times sweeter than table sugar and is generally considered safe for food. But little is known about its toxicity when inhaled. “Those evaluations are for eating, and it turns out the lung and the stomach are not the same target organ,” says study coauthor David Peyton, a chemist at Portland State University. Familiar with the chemistry of sucralose, Peyton and his team had a hunch that the compound might break down when heated by the metal coils inside e-cigarettes. To test the idea, they mixed up e-liquids and vaporized them using commercial devices in the lab. A pump drew air through the e-cig, and the scientists captured the puffs of vapor for analysis. Adding sucralose to a mix of typical e-liquid solvents, propylene glycol and glycerol, amplified the production of lung-irritating compounds called aldehydes by a factor of three to 10. Some of these compounds, including acetaldehyde and acrolein, are known to be toxic. The amount of aldehydes a user inhales would depend on factors including how concentrated the sucralose is and how hot the coil gets, Peyton says.
5-30-19 Damaged sense of smell fixed in mice by squirting stem cells up nose
Mice without a sense of smell have had the ability restored using stem cells delivered through the nose. The approach could pave the way for therapies that work in humans. One in eight adults in the US has problems with olfaction as a consequence of ageing, infection, physical trauma or a genetic disorder. Most issues with smell are permanent, and there are few treatments, says Bradley Goldstein at the University of Miami. While some studies have had success restoring smell in rodents using viral gene therapy, this is tailored for specific conditions. A stem cell-based approach could deal with a much broader set of olfactory problems. Goldstein says that many of the smell disorders that people develop through life appear to arise from problems in the tissue lining the nasal cavity, the olfactory epithelium. “It seems like some failures might be in repairing damage,” Goldstein says. “So we were really interested to know if there was a way to replace or restore those damaged cells that could be beneficial.” First, they genetically modified mice so that the neurons in their noses that are needed to sense smells – olfactory sensory neurons – didn’t have any of the hair-like structures that normally pick up odours. Then Goldstein and his team squirted droplets of so-called basal cells, which are responsible for the replacement of these neurons when they are old or damaged, into the rodents’ noses. These stem cells successfully created mature, working olfactory sensory neurons in the nasal cavity, which then connected to the olfactory bulb in the brain. When they tested the mice, they found those that were genetically modified with the faulty smelling neurons showed an inability to detect a bad smell. However, those with the genetic modification that had then had the stem cell treatment reacted to the smell in the way a regular mouse would.
5-29-19 The evolution of Archaeopteryx is stranger than anyone imagined
Winged Jurassic dinosaur Archaeopteryx was more than just an early ancestor of birds – fossils reveal it was an evolutionary wonder akin to Darwin's finches. ARCHAEOPTERYX has been an icon of palaeontology for over 150 years. Its discovery, a few years after the publication of On the Origin of Species, couldn’t have been better timed. Charles Darwin’s theory predicted that the fossil record should be full of transitional forms, as one species gradually evolved into another. Yet these missing links were, well, missing. Then, the strange birdlike dinosaur was unearthed – and instantly became a poster child for evolution. After all this time, you might think there is little left to discover about the “first bird”. In fact, much of its story has yet to be told. Only this February it emerged that the original fossil – a feather – was not what it seemed. And in recent years, we have found other contenders for the title of first bird. Nevertheless, new insights into the origins and lifestyle of Archaeopteryx reveal it to be a real trailblazer, making an epic journey over sea before settling on remote islands – a trip that shaped its evolution in a way that certainly would have intrigued Darwin. The first Archaeopteryx skeleton was found in Germany in 1861, close to – and shortly after – the feather. It was about the size of a crow, and headless. Only with the discovery of a second skeleton, a decade later, did it become clear that instead of a birdlike beak, Archaeopteryx had a snout filled with teeth. Eleven specimens have been found in total, although one vanished mysteriously in 1991 after the death of its owner. Those that remain reveal an animal that lived about 150 million years ago in what is now western Europe.
5-29-19 What makes a good smell? Inside a multibillion dollar aromatic mystery
Perfume prospectors travelling the world, AI researchers and neuroscientists are discovering the secrets of our least understood sense. I QUITOS is a hard place to get to. Nestled deep in the Peruvian Amazon, the city can only be reached by air or water – no roads connect it to the rest of the world. But for Stéphane Piquart, that remoteness is part of the appeal. An odour prospector for the French fragrance company Behave, Piquart went to Iquitos to search for new aromas. In particular, he was looking for a fragrant plant root that the local Shipibo people use in a love and friendship potion. The root, which the Shipibo call piri-piri, has a remarkable fruity-leathery scent that Piquart has now brought to perfumery. Visiting isolated places in search of new smells shows just how keen perfumers are on striking olfactory gold. That is driven by the sheer might of the fragrance industry. Always big business, it is now huge, with annual sales of $70 billion worldwide for not just perfumes but everything from soap and shampoo to candles and air fresheners. That is a lot of money to spend on nice smells. But what makes us like the ones we do? Smell is the least understood of our major senses, making this surprisingly tricky to answer. Neuroscientists, psychologists and even AI researchers are beginning to unpick the mysteries of how we perceive scent, while at the same time, fragrance researchers are devising new ways to tickle our olfactory neurons. The first clear lesson in what makes a good scent is that different cultures have different ideas about which smells are pleasant. “In Europe, people love anise,” says Christophe Laudamiel, a master perfumer based in New York and Berlin. “In America, I wouldn’t think of putting it in a fragrance.” Similarly, North Americans find the smell of the wintergreen plant highly pleasant, at least partly because it is a prominent ingredient in root beer. Europeans, in contrast, find it unpleasantly reminiscent of liniment, the stuff you might rub on aching limbs.Personal experience plays a key role in judgements of odour pleasantness. Unlike the other major senses, the nerve impulses involved in smell connect directly to the limbic system, the primitive parts of the brain responsible for memory and emotion. As a result, we judge the pleasantness of odours by the emotional memories they evoke. “A simple example is the scent of clove,” says Charles Sell, a chemist now retired from Givaudan, the world’s largest fragrance company. “I love it, because when I was a child, my mother used to make apple pie and put cloves in. But clove oil is also used in dentistry, so someone who has had a traumatic dental experience when there was clove oil will not like clove.”
5-29-19 Brain scans reveal magic mushroom drug enhances mindfulness meditation
Meditation and psychedelic drugs are both being investigated as potential treatments for improving mental health, but what happens when the two are combined? To find out, scientists invited a group of meditators to take psilocybin, the active component of magic mushrooms. Their self-reported experiences – and brain scans – hint that such a combined approach leads to stronger effects. Mindfulness meditation, a set of techniques designed to increase people’s attentiveness and acceptance of the present moment, is thought to have some beneficial effects on health, including possibly protecting against depression and anxiety. Psychotherapy accompanied by psychedelics are also being investigated as a possible treatment for depression and for anxiety in people with terminal illness. The mental states induced by meditation and psychedelics share some similarities, like altered perception of time and self-awareness, and previous neuroimaging studies have revealed some overlap in the patterns of brain activity they stimulate. But the effects of combining the two has never been studied with brain imaging before. A group of 38 healthy volunteers took part in a five-day mindfulness retreat in Switzerland, and had their brains scanned before and afterwards. They meditated for 10 hours a day, and Those who took psilocybin reported greater feelings of “boundlessness” – a loss of ego boundaries associated with feelings of bliss, serenity and oneness. The brain scans showed that these boundless feelings were linked to disruption of the default mode network, a set of brain regions that normally work together and may contribute to our sense of self. In the psilocybin group, and particularly in those who reported the strongest subjective effects, these regions were not as synchronous after the retreat.
5-29-19 How getting more daylight can improve your mental and physical health
Spending less time outside and more time in dim artificial light is disrupting our body clocks and undermining our health. The good news? A little daylight goes a long way. MORTEN HALMØ PETERSEN used to live in a windowless basement flat in Copenhagen. If he didn’t get out in the daytime, he would lose track of time and start becoming irritated and depressed. “When you are living in a basement with only artificial light, it becomes very clear that something is lacking,” he says. “It’s an emotional, physical and mental thing all combined.” You can say that again. Our lifestyles have rapidly changed our relationship with light. Prior to the invention of gas lighting at the turn of the 19th century, the only artificial light we could rely on was from flickering firelight, candles or whale-oil lamps. People also spent many more of their waking hours outside. Today, the average Westerner spends 90 per cent of their life indoors. That means we are getting less light during the day and being exposed to more light at night. This pattern is increasingly being linked to disrupted sleep and circadian rhythms – 24-hour fluctuations in our biology and behaviour – with consequences for our physical and mental health. Meanwhile, getting too little sunlight is contributing to vitamin D deficiency and may be undermining our immune and cardiovascular systems as well. Our changed relationship with the sun is profoundly affecting our biology. That’s why people like Petersen are being recruited by researchers to help investigate how much damage we do by shying away from the light, and just how much light we need. The good news is researchers are finding that even small increases in your exposure to bright light during the day have a wide range of benefits, from improving sleep and mood to speeding recovery from serious illness.
5-29-19 Working night shifts may not raise your breast cancer risk after all
Night shifts do not increase the risk of breast cancer, a ten-year study of more than 100,000 UK women suggests. Disrupted circadian rhythms have been linked to a number of disorders, and in 2007 the World Health Organization declared shift work to be a “probable carcinogen”. One theory is that artificial lighting means that night workers produce less of the of the night-hormone melatonin, which increases oestrogen production, which can affect the growth of breast tumours. But an analysis of data from 102,869 women suggests this many not be the case. “We found no overall link between women having done night shift work in the last ten years and their risk of breast cancer,” says Michael Jones, at the Institute of Cancer Research in London. Of the women studied, 2059 went on to develop invasive breast cancer. The team did observe a link between breast cancer incidence and the average number of night hours worked per week. However, they say this could be a “chance finding”, and that it is not supported by previous evidence. The WHO’s International Agency for Research on Cancer is set to review the evidence on night shift work and cancer later this year.
5-29-19 Should you give your data to a period tracker or smart breast pump?
Health tech firms believe that women are a lucrative and untapped market, but are these products worth the privacy costs? WOMEN’S health is going digital. The past few years have seen an upsurge in female health technology products and services. But as the industry takes off, some are concerned that the promise of personalised care comes at the expense of women’s privacy. These products run the gamut of reproductive health, including contraception, fertility and pregnancy. Among the apps and devices are period trackers, breast pumps and pelvic trainers. Ida Tin, CEO of menstruation-tracking app Clue, coined the term “femtech” to describe what she saw as a proliferation in products and start-ups “created around solving needs that women have because of our biology”, she says. In 2012, femtech companies attracted $57 million in funding. That figure swelled to $392 million in 2018 and major tech firms have got involved. Apple introduced period tracking to iPhones in 2015, and Fitbit added female health tracking to its watches in May last year, as did Garmin this April. Tens of millions of women use period-tracking apps such as Clue, Glow, Ovia and Flo. Clue now has 11 million active monthly users, says Tin. These apps allow women to track intimate details, including menstruation, sexual activity, cervical mucus, moods and pains. They can be used to monitor the fertile window for those trying to conceive, or to prevent pregnancy, as in the case of Natural Cycles, an app approved by the US Food and Drug Administration (FDA) as a form of contraceptive. The app has been criticised for resulting in unwanted pregnancies, but research shows it is more effective than condoms under typical use.
5-29-19 Family to be deported from Australia because son has cystic fibrosis
An Irish family who have been living in Australia for a decade are calling for help to avoid deportation after their Australian-born son, who has cystic fibrosis, was deemed to be a burden on taxpayers. More than 100,000 people have signed a petition calling on home affairs minister Peter Dutton to intervene and grant the Hyde family residency, after their appeal for permanent residency was denied due to the financial cost of their son’s cystic fibrosis on the healthcare system. Anthony and Christine Hyde moved to regional Victoria on working holiday visas in 2009 and received an offer to apply for permanent residency in 2015, just weeks before baby Darragh was due. Children born to non-residents aren’t automatically given citizenship in Australia. They must instead apply along with the parents’ immigration application and undergo a medical assessment. Because of the likelihood of a lung transplant or medication, immigration officers deemed Darragh a burden to the country and denied the family’s application for permanent residency. An appeal to overturn the decision failed, and the family are now hoping for a last-minute intervention from Dutton before their visa runs out on 18 June. Cystic fibrosis is a genetic condition that affects around one in every 2500 births in Australia. It progressively damages the lungs and digestive system and can eventually be fatal. Until recently, children like Darragh only had access to drugs that slowed the disease. But the Australian government has recently subsidised ivacaftor (sold under the brand name Kalydeco), an expensive new medication that treats the underlying cause of the disease rather than just the symptoms. Without government funding, ivacaftor would cost families around AU$300,000 each year. With the government funding it costs at most AU$40 per prescription.
5-29-19 DNA coated with silica could store masses of data in a single gram
DNA has emerged as a tantalising way to store digital information in recent years, but it comes with a significant problem: the molecule is so fragile that individual DNA strands rapidly degrade. A new technique to boost its survivability could see the molecules used to archive our data. DNA has been floated as a reliable medium for large data storage, partly because it has a theoretical storage capacity of about 4.55 million terabytes per gram. Unfortunately, the fragile molecule deteriorates unless it is stored under cool and dry conditions. “Then you have the mass and the size of the chamber in which you put the DNA,” says Robert Grass at ETH Zurich, Switzerland – so, in practice, it isn’t really possible to build facilities that store huge amounts of data in just a few grams. Grass and his colleagues worked in partnership with Microsoft to develop a DNA storage method that makes the molecule more robust. The method involves polymer-coated particles that help bind strands of DNA together and increase their storage density. The bound DNA strands are then coated with a protective layer of silica that limits environmental damage. The researchers compared the longevity of unprotected DNA with their coated version by encoding samples of each with data – using the DNA’s genetic code in place of digital 0s and 1s – before subjecting them to 70°C temperatures and 50 per cent relative humidity. Within a week, more than 98 per cent of the unprotected DNA was no longer readable. The encapsulated DNA was still readable after two weeks (Advanced Functional Materials, doi.org/c6dg). The team estimates that encapsulated DNA has a half-life of up to 90 years, if stored at 20°C.
5-28-19 No one can be truly anonymous ever again thanks to genetic sequencing
A battle between billionaires over the control of country club tennis courts six years ago could shape the future of genetic privacy. That is what a rapt audience attending a conference at Harvard Law School was told on 17 May. We had gathered there to discuss the ethical and legal considerations of the rapid spread of technologies that collect, analyse and alter DNA. Canadian businessman Harold Peerenboom and Marvel CEO Ike Perlmutter have been feuding for years, sparked by a disagreement over the management of recreation areas in their Florida neighbourhood, and fuelled by a subsequent campaign of defamatory mail anonymously sent to their local community. Peerenboom suspected Perlmutter of sending the hate mail. To find out if this was the case, Peerenboom worked with his lawyers to get a sample of Perlmutter’s DNA from a water bottle he used during a deposition. A similar approach was used to gather evidence against the suspected Golden State Killer last year, after police pinpointed a man by using a genealogy website. In 2013, a judge ruled that Perlmutter had a reasonable right to assume his genetic information on the lip of a water bottle wouldn’t be surreptitiously swiped, and that doing so deprived him of his “rights of ownership, possession, control, and privacy”, according to the case documents. The Perlmutter case changed the conventional wisdom that genetics isn’t property, Jessica Roberts of the University of Houston in Texas told me at the meeting. It sets a precedent that could rein in police investigations. It could also protect prominent people from a new kind of snooping. “It’s only a matter of time before we will see genetic paparazzi publishing genetic information on tabloid pages,” says Liza Vertinsky at Emory University in Georgia. “Lawsuits will follow.” Madonna has been known to hire cleaning crews to wipe down hotel rooms she has stayed in, for fear of just this scenario. But Vertinsky says it isn’t just celebrities who may be targeted, so could presidential candidates. Vertinsky wonders how the public would respond to hearing that a candidate has genes linked to risk-taking or schizophrenia, even though having a gene for a condition doesn’t necessarily mean you will develop it. Should voters base their opinions on the possible future health of candidates? She believes it won’t be long before courts have to rule on breaches of privacy like this.
5-28-19 One number can help explain why measles is so contagious
A disease’s R0 is the average number of people a person can infect in an unvaccinated population. Two ongoing outbreaks have dominated headlines in the past few months. Since the beginning of the year, measles has sickened at least 940 people in 26 U.S. states as of May 24. In Congo, Ebola has racked up 1,920 cases and killed 1,281 people since August 2018. Those numbers are scary, but another number, or rather a range, illustrates the potential of these diseases to do damage. It’s called the basic reproduction number, or R0 (pronounced “R naught”), a ratio that describes the contagiousness or transmissibility of an infectious disease. If one person is infected in an unvaccinated population, R0 gives an estimate of how many people would get sick from that individual, on average. Researchers can use R0 to estimate things like the size of an outbreak, the infectiousness of an emerging disease or the effectiveness of tactics against a hypothetical bioterrorism threat. Every infection event or outbreak has an R0. Three main variables go into calculating the ratio: how long people stay contagious (in days, for example), how often they come into contact with others on a daily basis and the probability of infecting someone else. Those factors are in turn influenced by things like the local environment, the average age of those infected, population density, public health resources and even the political climate. Within epidemics, R0 can vary from country to country and from one transmission route to another — for diseases that have more than one transmission route. That’s why when scientists talk about the R0 for a given disease more generally, they’re usually talking about a range. The basic reproduction number, R0, of an infectious disease is the number of people on average that would catch the pathogen from one infected person in a population without any immunity against the disease. Each dot in this graphic represents a person who would catch the disease from an infected individual. R0 is usually expressed as a range because the factors that go into this ratio vary depending on the time and place of an outbreak.
5-28-19 A 50-million-year-old fossil captures a swimming school of fish
This snapshot in time reveals that fish may have coordinated their motion long ago. Fossilized fish captured mid-swim offer a rare glimpse into extinct animal behavior — and suggest that swimming in schools developed at least 50 million years ago. A limestone shale slab from the Eocene Epoch reveals that extinct, thimble-sized fish called Erismatopterus levatus may have coordinated their motion similar to how fish in groups move today, researchers report May 29 in Proceedings of the Royal Society B. The fossil captures a mass of 259 fish apparently swimming in the same direction. It’s unclear what killed the fish. But a suddenly collapsing sand dune, for example, could have buried them in place in a flash, knocking just a few askew in the process, the researchers suggest. Analysis of the fish's positions and orientations suggests they followed the same rules of “attraction” and “repulsion” that govern fish shoals today: The fish are repelled from their nearest neighbors to avoid collisions, but stick with the group by tracking with farther away fishes. Because collective behavior is seen in so many animals, including the flocking of birds or swarming of insects, scientists believed such behavior evolved long ago. But there has been scant evidence in extinct species, says Nobuaki Mizumoto, a behavioral ecologist at Arizona State University in Tempe. (Webmaster's comment: Schooling is a survival behavior, and fish had millions of years to develope it, so of course they did.)
5-28-19 Breast cancer spreads through the body in just two or three waves
Most people who die from cancer are killed by cells that have spread through their body, but we know relatively little about how they spread. Now a team has genetically sequenced the secondary tumours of 10 women who died from breast cancer, and found that there are usually just two or three waves of migration from the original tumour. Carlos Caldas of the Cancer Research UK Cambridge Institute and his colleagues genetically sequenced samples from an average of 19 secondary growths per person. Some of the women, however, had hundreds of secondary tumours. Because all the tumour cells in a person’s body descend from a single cell with cancerous mutations, they were able to draw a “family tree” for each woman, showing how the tumour cells were related, and revealing how long ago they split from each other. “The number of mutations is effectively a clock,” says Caldas. The patterns of mutation suggested that the maximum number of spreading events any woman had was three, while the lowest was one. “There was a very limited number of these founding events, which must have been a burst of cells into the circulation,” says Caldas. The finding will help us to “know our enemy”, he says. Other teams are developing ways of catching and removing cancer cells as they spread through the blood.
5-28-19 How bacteria nearly killed by antibiotics can recover — and gain resistance
A protein that pumps toxic chemicals from the microbes allows some of them to resurge. Mostly dead bacteria can sometimes be resurrected as antibiotic-resistant cells. A protein that pumps toxic chemicals out of E. coli bacterial cells can buy time for even nearly dead microbes to become antibiotic resistant. The protein, known as the AcrAB-TolC multidrug efflux pump, doesn’t work well enough to defeat antibiotics on its own. But it can move enough antibiotic molecules out of bacterial cells to allow production of real resistance proteins, researchers report in the May 24 Science. Bacteria often swap DNA, including some antibiotic-resistance genes. Scientists have known for decades that antibiotic-resistance genes are often carried on small circles of DNA called plasmids. Two bacteria that come in contact with each other can pass these plasmids from antibiotic-resistant cells to sensitive ones. But that was thought to happen when antibiotics aren’t around to kill sensitive cells. Common wisdom holds that treating bacteria with antibiotics should stop bacteria in the act of swapping antibiotic-resistance genes, says Kim Lewis, a microbiologist at Northeastern University in Boston not involved in the study. At least, “yesterday, that’s what I would have told you,” he says. “Today, having read that paper, I have to change my views.” Bacterial geneticist Christian Lesterlin of CNRS-INSERM at the University of Lyon in France and colleagues wanted to know more about how bacteria pass antibiotic resistance to one another. The researchers genetically engineered E. coli to make fluorescent proteins that allowed the team to watch under the microscope in real time as bacteria swapped plasmids and made antibiotic-resistance proteins. (Webmaster's comment: Just like in Humans, it looks like dead cells pass on immunity.)
5-28-19 Millions 'lack access' to parks and green spaces
Millions of people in Great Britain do not have access to a nearby park or green space, a study suggests. The Green Space Index by Fields in Trust found that more than 2.5 million people lived more than a 10-minute walk from the nearest area. The charity has calculated that the average amount of green space per person is less than half of a six-yard-box on a football pitch. A growing body of research links parks and green spaces to wellbeing. "We actually found that 2.6 milion people did not live within a 10-minute walk of a green space," explained Field in Trust policy and insight manager Alison McCann. "In Great Britain, there is no statutory protection for green spaces," she told BBC News. "At the moment, we protect about 6% of our parks and green spaces, so we are calling for the Green Space Index to be used as an early warning system as we should be doing more to protect what we have got because of the multiple benefits they bring." Studies have shown that parks and urban green spaces deliver health and wellbeing benefits. Researchers have calculated that outdoor exercise delivered an estimated £2.2bn of health benefits to adults in England each year. The scientists calculated that more than eight million people each week took at least 30 minutes of "green exercise". In another study, carried out by a team from the European Centre for Environment and Human Health at the University of Exeter reported that living in an urban area with green spaces has a long-lasting positive impact on people's mental well-being. Ms McCann explained that research carried out by Fields in Trust found that parks delivered an estimated £34.2bn of health and wellbeing benefits each year. "If you use parks regularly, you are reaping some huge rewards," she said. "But the Index is showing that us that not everyone has that close access, to parks, so they are potentially missing out on those benefits."
5-28-19 How socialist health care saves lives
Two years ago, I wrote about the American health-care system's diligent efforts to kill a Texas man named Matthew Stewart through five-figure bills and strangling red tape. He has an autoimmune liver disease, which nearly resulted in his death. He was saved by a hospital he later discovered was out-of-network. Thanks to a loophole in ObamaCare regulations, that meant he faced bills of nearly $70,000 he couldn't pay. And because he couldn't get insured properly on the ObamaCare exchanges, he faced the dire prospect of being uninsured with a life-threatening illness. Well, I've got good news: Matthew escaped from Texas by the skin of his teeth and has moved to New York, where he gets reasonably good care. Why are things better in New York? Good old Big Government, in the form of Medicaid. It's an excellent demonstration of how socialist health care saves lives. It turns out that sick people do better when they can get the care they need for free at the point of access. Unfortunately, it's also a demonstration of the limitations of non-universal health care. To stay covered, Matthew has to stay in near-poverty. Just a few years ago, Matthew was a healthy young grad student, an avid hiker, happily married to a teacher and living in his own house. After he developed liver disease and nearly died in 2016, he could no longer work and had to drop out of school. But he still had to scale a mountain of bureaucracy to keep getting the treatments he needed to live — in particular, the quarterly surgical procedures necessary to stay ahead of the disease. With his mountain of debt, bankruptcy was the only way out, but merciless means tests in the process meant he had to wait months for his income — calculated on a rolling average — to decline enough to qualify after withdrawing from school. Then, because Texas didn't accept the ObamaCare Medicaid expansion, even if he could qualify for disability and get a small benefit he still couldn't get on Medicaid in that state, because his wife made too much money.
5-27-19 Even dim candlelight before bed is bright enough to disrupt sleep
You may have heard that bright lighting in the evenings can disrupt your sleep. But it turns out some of us are more sensitive to this effect than others. A new study suggests people’s threshold for their body clock hormones being disturbed by late-night light can vary by more than fifty-fold. “For some people, a dim reading light might as well be daylight, and for others it might as well be darkness,” says Sean Cain at Monash University in Melbourne. Our bodies experience many biochemical fluctuations over the day, with a key regulator being a hormone called melatonin. This naturally starts rising in the evening, which promotes sleepiness, but the surge can be delayed by artificial lights, especially the blue-enhanced illumination from phones, computers and TVs. Some believe we can improve our sleep patterns and health by lowering light exposure in the evening and boosting it during the day. Most previous studies into the effects of light levels on melatonin have studied groups of people, averaging out their reactions. But Cain’s team looked at the individual responses to evening light among 55 men and women. The volunteers had to keep a strict sleep schedule for up to eight weeks based on their preferred bedtime. One night a week, they came into the lab and were exposed to a certain light level – from dim to bright, in a random order – starting four hours before bedtime, and their melatonin levels were measured. People had markedly different responses. In the most sensitive person, a very dim light level of 6 lux, equivalent to a few candles, was enough to halve their melatonin levels – which previous work suggests would delay sleep onset by 30 to 60 minutes depending on the person.
5-24-19 An emergency in rural America
In Oklahoma a hospital is losing a fight to survive, says journalist Eli Saslow in The Washington Post. It’s the story of hospitals across America—and the struggling counties that rely on them. The hospital had already transferred out most of its patients and lost half its staff when the CEO called a meeting to take inventory of what was left. Employees crammed into Tina Steele’s office at Fairfax Community Hospital, where the air-conditioning was no longer working and the computer software had just been shut off for nonpayment. “I want to start with good news,” Steele said, and she told them a food bank would make deliveries to the hospital and Dollar General would donate office supplies. “So how desperate are we?” one employee asked. “How much money do we have in the bank?” “Somewhere around $12,000,” Steele said. “And how long will that last us?” “Under normal circumstances?” Steele asked. She looked down at a chart on her desk and ran calculations in her head. “Probably a few hours,” she said. “Maybe a day at most.” The staff had been fending off closure hour by hour for the past several months, ever since debt for the 15-bed hospital surpassed $1 million and its outside ownership group entered into bankruptcy, beginning a crisis in Fairfax that is becoming familiar across much of rural America. More than 100 of the country’s remote hospitals have gone broke and then closed in the past decade, turning some of the most impoverished parts of the United States into what experts now call “health-hazard zones,” and Fairfax was on the verge of becoming the latest. The emergency room was down to its final four tanks of oxygen. The nursing staff was out of basic supplies such as snakebite antivenin and strep tests. Hospital employees had not received paychecks for the past 11 weeks and counting. A technician had gone $100,000 into debt after having an emergency preterm birth, because none of the hospital’s employees had benefits or insurance. The only reason the hospital had been able to stay open at all was that about 30 employees continued showing up to work without pay, increasing their hours to fill empty shifts and essentially donating time to the hospital, understanding what was at stake. There was no other hospital within 30 miles of two-lane roads and prairie in sprawling Osage County, which meant Fairfax Community was the only lifeline in a part of the country that increasingly needed rescuing. “If we aren’t open, where do these people go?” asked a physician’s assistant, thinking about the dozens of patients he treated each month in the ER, including some in critical condition after drug overdoses, falls from horses, oil field disasters, or car crashes. “They’ll go to the cemetery,” another employee said. “If we’re not here, these people don’t have time. They’ll die along with this hospital.” “We have no supplies,” Steele said. “We have nothing. How much longer can we provide quality care?”
5-24-19 Drug prices: Get ready for sticker shock from TV ads
A change could be coming to all those prescription drug commercials you see on TV, said Glenn Thrush and Katie Thomas in The New York Times. A new proposal last week by the Trump administration would require drugmakers “to include the price of prescription drugs in television advertisements if the cost exceeds $35 per month.” The 10 most commonly advertised drugs have list prices ranging from $488 to $16,938 per month, so the rule would cover most drug ads. The drug industry could challenge the proposal. It has argued that the rule “could violate the companies’ First Amendment rights” and that most patients with insurance pay far less for their prescriptions. But the administration is betting that patients’ sticker shock at seeing sky-high prices on television ads “could prompt drug companies to lower their costs out of fear consumers would reject their products.” Anything that spurs competition is a good thing, said Ge Bai in The Wall Street Journal, and seeing the list price makes it easier for consumers to comparison shop. As with cars, even if almost no one pays the list price, disclosing it creates a benchmark for comparing prices. I co-authored a study that found that “disclosing prices in advertisements reduced consumer interest in expensive drugs by 43 percent.” That’s a lot of lost customers if drugmakers don’t voluntarily lower the list prices. “Consumers deserve to see what’s behind an estimated $4 billion per year in slick ad-making,” said the San Francisco Chronicle in an editorial. “The happy TV couple walking along a beach” won’t be so appealing when consumers see that the arthritis pills promoted on TV cost $5,000. And if pharmaceutical companies are shamed by their high prices, guess what? “They can lower them.”
5-24-19 Statins could slow ravages of MS
People suffering from multiple sclerosis may be able to slow its progression by taking statins. Researchers at University College London examined 140 people with secondary progressive MS, a stage of the disease in which the patient’s condition steadily worsens. Over two years, MRI scans showed that those given a high (80 mg) daily dose of simvastatin—a widely distributed statin used to treat high cholesterol—experienced 43 percent less brain volume reduction than those on a placebo. The disability levels of the simvastatin takers also progressed more slowly, and they recorded improved scores on a questionnaire about how MS affected their daily life. “Although this study cannot provide a final answer as to what exactly is the reason for the success of statins in progressive MS, it directs future researchers toward certain pathways,” lead author Arman Eshaghi tells ScienceDaily.com. Separately, researchers have found that statins may also reduce the risk for glaucoma. In a 15-year study involving 136,782 people, those who regularly took statins for five or more years had a 21 percent lower risk of developing the eye condition.
5-24-19 Using ‘phages’ to halt infections
Doctors have used a genetically engineered virus to save the life of a British teenager suffering from an infection that wouldn’t respond to antibiotics—offering new hope in the fight against drug-resistant bacteria. Isabelle Holdaway, now 17, was given a 1 percent chance of surviving a respiratory infection that had returned even after a double lung transplant. In a last-chance effort, her doctors teamed up with Graham Hatfull at the University of Pittsburgh to see if “phage” therapy—the use of a bacteria-killing virus to attack infections—might work. Unlike antibiotics, phages have to be carefully selected to match every strain of bacteria. Hatfull and his colleagues identified a phage that could neutralize the infection, then removed one of its genes to make it more efficient. Holdaway’s infection was brought under control six weeks after she started phage treatment. While she isn’t fully cured—she still receives daily infusions of the viral cocktail—her symptoms have been significantly reduced. Doctors hope the success will lead to more clinical trials for phage treatments.
5-24-19 A surprising link to Parkinson’s
People who have their appendix taken out are three times more likely to develop Parkinson’s disease, a new study suggests. Previous research has found alpha-synuclein, a protein that often forms in clumps in the brains of Parkinson’s sufferers, in the appendix. But studies exploring whether an appendectomy increases or decreases Parkinson’s risk have been inconsistent. To explore the link, researchers at Case Western Reserve University looked at data for 62.2 million patients, reports The Daily Telegraph (U.K.). They found that of the nearly 500,000 people who’d had appendectomies, 0.92 percent went on to get Parkinson’s—compared with only 0.29 percent of those who hadn’t had the procedure. The researchers say one possible explanation is that alpha-synuclein is released into the body during an appendectomy, and makes its way up to the brain. However, other studies have found weaker associations—and a Swedish study last year found that people who’d had their appendix removed in their youth had a lower chance of getting Parkinson’s.
5-24-19 Battling Ebola and fear
The second-largest Ebola outbreak in history is threatening to spiral out of control in rural Congo because of mistrust of the government and foreigners. The outbreak—which has so far killed more than 1,200 people—began last summer shortly before an election in an opposition stronghold that had suffered government violence. When voting was suspended over fears that the deadly hemorrhagic disease could spread at polling places, locals assumed Ebola was part of a government plot. Suspicions further intensified because United Nations vaccination teams travel with a military escort, which makes them look like an arm of the regime. Ebola is highly contagious and can be spread by dead bodies, but families are chasing away burial teams. “The new protocol is that we just abandon the body,” said burial worker Philemon Kalondero. “They will learn their lesson when they get sick.”
5-24-19 Being bilingual is great. But it may not boost some brain functions
Knowing a second language didn’t come with better attention control, a study of U.S. kids finds. Advantages of speaking a second language are obvious: easier logistics when traveling, wider access to great literature and, of course, more people to talk with. Some studies have also pointed to the idea that polyglots have stronger executive functioning skills, brain abilities such as switching between tasks and ignoring distractions. But a large study of bilingual children in the U.S. finds scant evidence of those extra bilingual brain benefits. Bilingual children performed no better in tests measuring such thinking skills than children who knew just one language, researchers report May 20 in Nature Human Behaviour. To look for a relationship between bilingualism and executive function, researchers relied on a survey of U.S. adolescents called the ABCD study. From data collected at 21 research sites across the country, researchers identified 4,524 kids ages 9 and 10. Of these children, 1,740 spoke English and a second language (mostly Spanish, though 40 second languages were represented). On three tests that measured executive function, such as the ability to ignore distractions or quickly switch between tasks with different rules, the bilingual children performed similarly to children who spoke only English, the researchers found. “We really looked,” says study coauthor Anthony Dick, a developmental cognitive neuroscientist at Florida International University in Miami said. “We didn’t find anything.”
5-24-19 Organic matter from space preserved in 3.3-billion-year-old rocks
A thin layer of 3.3 billion-year-old rock contains unexpected treasure: organic matter that was carried to Earth by meteorites when the planet was still young. The find supports the idea that organic, meaning carbon-based, chemicals from space supplied some of the raw materials for the first life on Earth. It could also complicate the search for life on other planets. “This is the very first time that we have found actual evidence for extraterrestrial carbon in terrestrial rocks,” says Frances Westall of the CNRS Centre for Molecular Biophysics in Orle´ans, France. Scientists have long known that carbon-based chemicals can be found in space. In particular, molecules like amino acids and nucleotides that are used by life have been found in meteorites. As a result, many suspect meteorites carried these essential building blocks of life to the primeval Earth. Westall and her colleagues studied a slab of rock from the Josefsdal Chert in eastern South Africa, which contained many layers laid down over time. “There was this one layer with this outstanding signature,” says Westall. “It’s very similar to organic matter in meteorites.” Further analyses revealed that the layer contained minerals called spinels that are known to form in meteorite impacts. The team suspects the carbon-based matter was thrown into the air as a fine dust after the meteorite hit. The dust then fell to earth and was buried under volcanic ash. This preserved the extraterrestrial carbon in one discrete layer: in other circumstances it would have mixed with living matter, rendering it undetectable. Similar samples may be rare, Westall says, but not impossible to find. Meteorites hit the Earth regularly from its birth 4.5 billion years ago until about 3 billion years ago. “The organic matter from the carbon-rich meteorites must have been raining down at quite a high rate,” says Westall. The carbon could have been used by the first life. We do not know when life formed, but there are fossil microbes from 3.4-3.5 billion years ago.
5-23-19 Robots conduct daily health inspections of schoolchildren in China
Please stand in front of Walklake for your examination. This health checking robot takes just 3 seconds to diagnose a variety of ailments in children, including conjunctivitis, and hand, foot and mouth disease. Over 2000 preschools in China, with children aged between 2 and 6, are using Walklake every morning to check the health status of their students. Walklake has a boxy body and smiling cartoony face. Before children enter the classrooms, they stand in front of the robot for a quick checkup by showing it their eyes, throats and hands. The robot has an infrared thermometer on its forehead, as well as cameras on its eyes, mouth and chest. Its system is trained to scan for disease symptoms, such as fever, hand blisters, throat sores and red eyes. If it detects something abnormal, the robot will alert teachers or school nurses who then manually check the child again and decide if they should be sent home. Since 2016 the Chinese government has recommended all preschools should conduct a morning heath examination on students to reduce the transmission of disease. However, normally this is done by a person. Robots can help streamline the process. After scanning all students, Walklake aggregates the health data and sends the principal an illness report of the entire school. “It’s allowing for better health monitoring, especially in places that have large populations but not enough skilled health professionals,” says Karen Panetta at Tufts University in Massachusetts. She suggests if the robot becomes more prevalent, health officials can use its data to pinpoint the spread of diseases, and thus implement proactive interventions.
5-23-19 Sweaty, vinegary and sweet odors mingle to make dark chocolate’s smell
Researchers reconstructed the aroma in the lab. Scientists have sniffed out the chemicals that give some dark chocolates their smell. The compounds that mingle to make the candy’s aroma include pleasant-smelling ones such as vanillin, which gives vanilla its smell, and flowery linalool. But other molecules produce smoky or vinegary odors and even one that smells like sweat, researchers report online May 8 in the Journal of Agricultural and Food Chemistry. “These single odorants usually never have the typical smell of the food itself,” says Michael Granvogl, a food chemist at the University of Hohenheim in Stuttgart, Germany. Instead, in any given food, the scent depends on which molecules are present and at what level, he says. Granvogl and his colleague Carolin Seyfried of the Technical University of Munich picked two particularly aromatic chocolate bars having at least 90 percent cocoa content from a grocery store. The pair crushed up each of the treats and extracted their volatile compounds, those that vaporize easily and can waft up to our noses to be smelled. Of the roughly 70 aroma-producing volatile chemicals detected, between 28 and 30 occurred in each bar at high enough levels for humans to smell. By combining these compounds at roughly the same concentrations as in the original chocolate bars, the scientists re-created each bar’s aroma. A panel of more than 20 people with trained noses sniffed the concoctions and found that they smelled similar to the real deal. The study is the first to reconstruct dark chocolate’s smell from odor compounds measured using state-of-the-art techniques, the researchers say.
5-23-19 The average animal will be 10 per cent smaller in the next century
The world’s animals are collectively shrinking, as humans drive big beasts such as elephants and tigers extinct, with far-reaching consequences for ecosystems. Previous studies have shown bigger animals are at a greater risk of extinction and there is evidence humans have helped wiped out megafauna in the past, including woolly mammoths. Now an assessment of the next 100 years has found that habitat destruction, poaching and other human pressures will cause mammals and birds to experience “substantial ecological downsizing”. Researchers ran a thousand scenarios on the future of the 15,500 species on the Red List of endangered species. Each species was assigned a probability of extinction by 2119. Critically endangered ones such as the black rhinoceros were given a 99 per cent likelihood of disappearing, while vulnerable ones such as leopards had a 10 per cent probability. The results showed the loss of big species would see the average body mass of animals drop around 9 per cent from today, to 64.1 grams in 2119. “It’s due to the loss of these big charismatic species like elephants and tigers, and you’re left with songbirds and rodents,” says Rob Cooke of the University of Southampton, who led the research. There will also be a shift to insect-eating species with shorter lifespans, and ones that can thrive in a variety of habitats. The real change is likely to be worse, says Richard Twitchett of the Natural History Museum, because we know from the fossil record that even the survivors of past extinctions are likely to be smaller.
5-23-19 'Unique' Iron Age shield discovered in Leicester
A 2,300-year-old Iron Age shield has been revealed by archaeologists. Found during a dig near Leicester in 2015 and dated to between 395 and 255BC, the shield was made of painted bark, backed by wooden spars. Analysis showed it had been badly damaged, probably by spears and edged weapons, before being left in a pit. Experts said the shield gave an "unparalleled" insight into prehistoric technology. The shield, which measured 670 x 370mm (26ins x 15ins), was found on the Everards Meadows by University of Leicester Archaeological Services (ULAS) archaeologists. The bark used was from either alder, willow, poplar, hazel or spindle and the stiffening spars were made of apple, pear, quince or hawthorn. The shield had a rim of split hazel rod and a boss, to protect the hand, woven from a willow core. Mike Bamforth, from the University of York, used CT scanning and 3D printing to help reveal its secrets. He said: "This truly astonishing and unparalleled artefact has given us an insight into prehistoric technology that we could never have guessed at. "Being part of the team working to tease apart the complex secrets of the shield's construction has been incredibly interesting and rewarding." Archaeologists said such shields might have been common in the Iron Age but their organic materials meant they rarely survived. A reconstruction showed that while it was not as strong as solid wooden ones, the shield could stop blows effectively and had the advantage of being extremely light. The British Museum, which will store the shield, described it as a "absolutely phenomenal object"
5-22-19 How antibiotic resistance is driven by pharmaceutical pollution
Factories in India making cheap antibiotics for the world are dumping their waste, with grim consequences for people living nearby – and global health too. THE Medak district, to the north-west of Hyderabad in southern India, was once a pristine landscape. People came to bathe in the cool, refreshing lakes and streams. These days the air is foul. With every breath, chemicals irritate your lungs and, after a while, you feel nauseous. The colour of the water doesn’t help: it ranges from bright orange to deep brown, and is often covered in a thick layer of white foam. The reason for this blight is not well hidden. Behind high walls and barbed wire fences, factories churn out cheap drugs for the global market. Tall chimneys belch black smoke and tankers trundle along dirt tracks under cover of darkness to dump toxic chemical waste. “It’s like a slow poison,” says Batte Shankar, the head of one village we visited. “When you Europeans are taking these antibiotics to heal, it is good for you. But we are suffering.” However, when we came to the region to investigate the environmental situation and its consequences for the health of the people who live there, we were also aware of something even more insidious. The foetid lakes and streams contain extraordinarily high concentrations of antibiotics, creating reservoirs of the drug-resistant pathogens that kill hundreds of thousands of people every year. Some suspect these places might even be incubating new superbugs that could rapidly spread around the world. Now the challenge is to figure out whether people in this part of India are being harmed by antibiotic pollution, and the extent to which global health is in the firing line. It is also part of a last-ditch attempt to convince the authorities in India and elsewhere to take the problem seriously before it is too late.
5-22-19 Deaths from strokes in England have halved in just a decade
Over the course of a decade, the mortality of strokes has halved in England. Stroke occurs when the blood supply to part of the brain is cut off. The rate of people dying from this condition decreased by 55 per cent between 2001 and 2010. The analysis looked at data from almost 800,000 adults in England who were admitted to hospital with acute stroke or who died from a stroke during that period. In men, overall death rates dropped from 140 per 100,000 people in 2001, to 74 per 100,000 people in 2010. In women, they decreased from 128 per 100,000 to 72 per 100,000. In 2001, 42 per cent of men and 44 per cent of women who experienced a stroke did not survive beyond 30 days, the study found. By 2010, this figure was 26 per cent in men and 29 per cent in women. While the overall number of strokes dropped by around 20 per cent over the decade, there was a rise of 2 per cent every year among people aged 35 to 54 years old. “The increase in stroke event rates in young adults is a concern,” the University of Oxford team said. “This suggests that stroke prevention needs to be strengthened to reduce the occurrence of stroke in people younger than 55 years.”
5-22-19 Faulty cellular antennae may cause a heart valve disorder
The discovery could help researchers understand how mitral valve prolapse develops. Cells with faulty antennae that can’t get their signals straight may be behind a common heart valve disorder. Newborn mice engineered to develop a flawed heart valve had stunted primary cilia in cells that help to form the valve during development, researchers report online May 22 in Science Translational Medicine. The heart valve disorder, called mitral valve prolapse, “is characterized by significant abnormalities in the composition and organization” of valve tissue, says Joy Lincoln, a heart valve researcher at Nationwide Children’s Hospital in Columbus, Ohio. Those abnormalities compromise the valve’s structure and function. The new work hints that primary cilia play a role in this improper development, she says. The condition, which affects about 2 percent of the U.S. population, causes the valve separating two heart chambers — the left atrium and the left ventricle — to not seal properly. Normally, when the left ventricle pumps oxygenated blood to the body, the valve closes tightly so blood doesn’t backtrack into the atrium. But with mitral valve prolapse, parts of the valve bulge into the atrium, which can let blood through. A leaky valve can produce a heart murmur, a “click” sound a doctor can hear with a stethoscope. Some people with the condition don’t experience any symptoms, while others may have rapid heartbeats or discomfort in their chest. If there is a lot of leaking blood, the heart may develop an infection, blood clots may form and raise a person’s risk of stroke or heart attack, or a person’s heart may eventually fail. The only way to fix the valve is with surgery.
5-22-19 Specially created animal 'cancer avatars' could personalise treatments
Cancer is often said to be not one disease, but many. Each person’s tumour has a different set of mutations, so while a certain treatment might see off one person’s breast cancer, for instance, it may fail at treating someone else’s. The hard part is knowing which treatment will be the best for a specific tumour. Now doctors are starting to determine the best options by testing different drugs on specially created animals that have been given replicas of a patient’s cancer – known as “cancer avatars”. One option could be to generate Drosophila fruit flies with the same genetic mutations as a person’s cancer. These flies are small and live only for a short time, meaning researchers can generate large numbers of them in multiple rows of test tubes. Robotic equipment can then be used to screen hundreds of drug combinations on the flies. This approach was used to guide treatment for a man who had terminal colon cancer. He died after about three years but this was probably longer than he would have lived otherwise, says Ross Cagan of the Icahn School of Medicine at Mount Sinai in New York. Before making the fruit fly avatars, the man’s cancer had already spread round his body and developed resistance to several drugs. Genetic sequencing revealed the tumour had at least nine cancerous mutations. The team genetically engineered a strain of flies that had all these mutations in their gut cells – and then bred over 300,000 of them. They then developed a robotic system to feed the flies and test different medicines on them. In this way, they screened 121 existing medicines – including both cancer drugs or treatments for other conditions – either singly or in combinations of up to three.
5-22-19 Gut microbes may determine whether infants develop food allergies
Young immune systems are sensitive to food allergens if they don’t have the right gut bacteria, a study in mice suggests. Sung-Wook Hong of the Institute for Basic Science in South Korea and his colleagues have been investigating the effects of the microbiome on allergies and the immune system. They wondered why mice raised in a sterile environment without any gut microbes suddenly produce high levels of a type of antibody when they are weaned onto solid food. These immunoglobulin E (IgE) antibodies form the arm of our immune system that mediates allergic responses to certain chemicals. When IgE antibodies detect allergens, they trigger the release of inflammatory chemicals that lead to the symptoms of allergies. To understand why IgE spikes in microbe-free mice during weaning, the team fed young mice either a normal diet or one formulated with just the necessary amino acids, vitamins and glucose – nothing that could provoke the immune system. They found that the mice on the normal diet spontaneously developed an immune response, while the ones on the antigen-free diet did not. This suggests that the lack of a healthy gut microbiome is linked to a food-triggered immune response in mice, says Hong. However, when the team delayed introducing normal solid food until the microbe-free mice were adults, they found that they produced less IgE antibodies. The team found that a special type of immune cell, called T follicular helper cells, were involved in the IgE response seen in the mice. This kind of T cell is mostly generated early in life. This finding helps explain why allergies are more common in children than adults, says Hong.
5-22-19 The parenting myth: How kids are raised matters less than you think
DNA is more important to a child’s personality, exam results and future income than the way they are brought up – but that’s good news, says geneticist Robert Plomin. IT IS an age-old question: are we shaped more by nature or nurture? Robert Plomin, a geneticist at King’s College London, has spent his career teasing apart the contributions of DNA and environmental factors to countless human traits, from body weight to personality and academic success. Environment is undoubtedly a key influence on almost every aspect of our lives. But Plomin argues that genetics plays a more important and measurable role, even to the extent that our parenting and schooling don’t matter that much. We caught up with him to discuss his sometimes controversial views. Give us an example showing how little influence parenting has on the way children turn out. Take our propensity to be overweight. If zero means parents have no influence and one means total influence, when two siblings grow up together, their body mass index has a correlation of about 0.4. It’s easy to see how people attribute that mainly to nurture, because parents provide both siblings with the same food. But it turns out that isn’t true, and obesity runs in families for reasons of genetics. A killer piece of data is that the correlation for weight is 0 between adoptive siblings who grow up in the same family but don’t share genes. Even more striking is that if you were adopted at birth away from your sibling, you correlate just as much as if you had been reared together in the same family. Is this true for intelligence and personality too? Definitely for cognitive abilities. There aren’t as many studies on personality, but we know that identical twins reared apart are as similar in personality as identical twins reared together. I’ve studied identical twins who have grown up apart, and I find it amazing how they are so similar in things like the way they laugh or talk. What do these findings mean for who we are, and who we become? Twin and adoption studies have shown us that about half the differences between people in any trait you want to name is due to DNA differences, and half isn’t. But whatever the environment is, it makes two kids in the same family as different as those in two different families. The effects of the environment are random. The implications of these findings are enormous because it means inherited differences are the major systematic [non-random] force in making us who we are.
5-22-19 Writing about your life can help your self-esteem
Studies show that noting down a chapter of your life can improve your sense of self. n truth, so much of what happens to us in life is random — we are pawns at the mercy of Lady Luck. To take ownership of our experiences and exert a feeling of control over our future, we tell stories about ourselves that weave meaning and continuity into our personal identity. Writing in the 1950s, the psychologist Erik Erikson put it this way: To be adult means among other things to see one's own life in continuous perspective, both in retrospect and in prospect … to selectively reconstruct his past in such a way that, step for step, it seems to have planned him, or better, he seems to have planned it. Alongside your chosen values and goals in life, and your personality traits — how sociable you are, how much of a worrier and so on — your life story as you tell it makes up the final part of what in 2015 the personality psychologist Dan P. McAdams at Northwestern University in Illinois called the "personological trinity." Of course, some of us tell these stories more explicitly than others — one person's narrative identity might be a barely formed story at the edge of their consciousness, whereas another person might literally write out their past and future in a diary or memoir. Intriguingly, there's some evidence that prompting people to reflect on and tell their life stories — a process called "life review therapy" — could be psychologically beneficial. However, most of this work has been on older adults and people with pre-existing problems such as depression or chronic physical illnesses. It remains to be established through careful experimentation whether prompting otherwise healthy people to reflect on their lives will have any immediate benefits.
5-22-19 The truth about lie detectors: They don't work and never have
Polygraph machines remain in use despite being widely discredited, and there are much better alternatives for seeking the truth. THE Jeremy Kyle Show, which has been broadcast in the UK since 2005, was axed by ITV last week. It featured people with troubled relationships arguing in front of a live audience, often spiced up with the addition of a lie detector test. In an episode filmed recently, but never broadcast, a guest failed such a test designed to find out if he had cheated on his fiancée. He was later found dead. Lie detector tests aren’t exactly rare on TV. We can thank Kyle’s US predecessor Jerry Springer for cementing their popularity, and they endure on shows like Love Island, another ITV programme. But their reach goes wider. In Ukraine, evidence from lie detector tests, also known as polygraphs, is admissible in court, while in the US they are used as part of the recruitment process to government jobs. All this is rather worrying as lie detectors don’t live up to their name. They have long been discredited, while other methods of finding the truth are gaining ground. “It’s good that the show has ended,” says George Maschke, an anti-polygraph campaigner based in the Netherlands. He says the programme contributed to the public mistakenly believing that lie detectors work or have any scientific basis. ITV didn’t respond to questions about its use of lie detectors. Polygraph machines measure a person’s pulse, blood pressure and breathing while they answer a series of control questions, like what they ate for breakfast or their age. Then the person is asked a more pertinent question, such as: “Did you cheat on your partner?” If their vital signs leap, they are judged to be lying.
5-22-19 Some plants use hairy roots and acid to access nutrients in rock
Fine hairs and chemicals that dissolve rocky substrates are crucial in regions with little soil. No soil? No problem. Some herbaceous shrubs living on rocky mountains in Brazil use roots equipped with fine hairs and acids to dissolve rocks and extract the key nutrient phosphorus. The discovery, published in the May Functional Ecology, helps explain how a variety of plants can survive in impoverished environments. “While most people tend to view nutrient-poor environments as less diverse, they are actually very diverse because plants use diverse ways to get nutrients,” says coauthor Patricia de Britto Costa, a plant ecologist at the University of Campinas in Brazil. She and other colleagues in Brazil and Australia investigated how shallow-soil regions called campos rupestres in Portuguese, or rocky grasslands, can sustain more than an estimated 5,000 plant species — 15 percent of Brazil’s vascular plant diversity — despite occupying less than 1 percent of the country’s land area. What soil there is in these regions is poor, with nearly undetectable levels of the nutrients that plants need. And some plants manage to survive on rocky patches with no soil. Researchers used chisels and hammers to dig up the plants. “We found the roots growing into the rocks,” at least 10 centimeters deep, says coauthor Anna Abrahão, a plant ecologist now at the University of Hohenheim in Stuttgart, Germany. “The roots go deeper, and we always lose some of them.”
5-21-19 DNA from mummy's tomb reveals ancient Egyptian origins of watermelon
Did ancient Egyptian children compete to see who could spit seeds the furthest as they ate watermelons? It seems likely, because thanks to some DNA detective work we now know for sure that the ancient Egyptians ate domesticated watermelons with sweet, red flesh. The wild watermelons found in parts of Africa are nothing like the domesticated varieties. They are small, round and have white flesh with a very bitter taste due to compounds called cucurbitacins. There’s long been debate about when and where they were domesticated, with some suggesting it took place in south Africa or west Africa. However, pictures on the walls of at least three ancient Egyptian tombs depict what look like watermelons – including one that looks strikingly like modern varieties (pictured below). And in the 19th century, watermelon leaves were found placed on a mummy in a tomb dating back around 3500 years. When botanist Susanne Renner at the University of Munich, Germany, learned about these leaves, she realised their DNA might reveal what the ancient melons were like. She also discovered that some of the leaves had been sent to the famed botanist Joseph Hooker, then head of Kew Gardens in London. “It was my love of the old literature,” she says. Mark Nesbitt at Kew gave Renner’s team a tiny sample of one leaf. He had trouble opening the display case containing the leaves, she says, as it had not been opened since the leaves were first placed in it in 1876. The ancient DNA was then sequenced by Renner’s colleague Guillaume Chomicki, now at the University of Oxford. The team were only able to get a partial genome sequence, but it includes two crucial genes that reveal what these melons were like. “We were so lucky,” says Renner.
5-21-19 Finding common ground can reduce parents’ hesitation about vaccines
Changing the doctor’s office conversation could stem the spread of disease. About six years ago, Emily Adams, a mother of two in Lakewood, Colo., briefly counted herself among the vaccine hesitant. Her family had changed insurance plans, and while her older daughter was up-to-date on shots, her infant son fell behind. “We were no longer on schedule, just because of life,” she says. Adams remembers mentioning her son’s situation to a friend, who suggested Adams hold off longer. The friend recommended some books discounting the science behind vaccines. Adams began reading, which led to about six months of feeling unsure about continuing to immunize her son. In the end, Adams did not find the books convincing. She credits her sister, a molecular biology doctoral student at the time, with helping her sort through her concerns. Today, both of Adams’ children are fully vaccinated. Adams eventually found other parents like her — “crunchy,” she says — with shared views on the environment, homemade baby food, cloth diapers and a belief in vaccination. She also became involved with Colorado Parents for Vaccinated Communities, which advocates for pro-vaccine policies. Adams has had conversations about vaccines with some doubting friends, who have “seemed really open when I’ve said things gently.” She’s even changed a few minds. The circumstances that led to Adams’ hesitancy illustrate the cracks in the country’s foundation of infectious disease prevention, cracks that are creating vulnerable communities. And vaccine hesitancy, defined as the delay in acceptance or the refusal of vaccines despite their availability, is a growing problem.
5-21-19 Measles erases the immune system’s memory
Beyond the rash, the infection makes it harder for the body to remember and attack other invaders. The most iconic thing about measles is the rash — red, livid splotches that make infection painfully visible. But that rash, and even the fever, coughing and watery, sore eyes, are all distractions from the virus’s real harm — an all-out attack on the immune system. Measles silently wipes clean the immune system’s memory of past infections. In this way, the virus can cast a long and dangerous shadow for months, or even years, scientists are finding. The resulting “immune amnesia” leaves people vulnerable to other viruses and bacteria that cause pneumonia, ear infections and diarrhea. Those aftereffects make measles “the furthest thing from benign,” says infectious disease epidemiologist and pathologist Michael Mina of Harvard University. “It really puts you at increased susceptibility for everything else.” And that has big consequences, recent studies show. Details about which immune cells are most at risk and how long the immune system seems to suffer — gleaned from studies of lab animals, human tissue and children before and after they had measles — have created a more complete picture of how the virus mounts its sneak attack. This new view may help explain a larger-than-expected umbrella of safety created by measles vaccination. “Wherever you introduce measles vaccination, you always reduce childhood mortality. Always,” says virologist Rik de Swart of Erasmus University Medical Center in the Netherlands. The shot prevents deaths, and more than just those caused by measles. By shielding the immune system against one virus’s attack, the vaccine may create a kind of protective halo that keeps other pathogens at bay, some researchers suspect.
5-21-19 How the battle against measles varies around the world
Conflict, inequality and skepticism limit global vaccine coverage. The World Health Organization’s goal was lofty but achievable: eliminate measles from five of the world’s six regions by 2020. But recent outbreaks — even in places where elimination had been achieved — are making that goal a distant dream. In the first four months of 2019, 179 countries reported 168,193 cases of measles. That’s almost 117,000 more cases reported during the same period last year. Actual numbers are probably much higher; the WHO estimates that only 1 in 10 cases are reported. With this uptick, none of the regions will meet the 2020 goal, says pediatrician Ann Lindstrand, vaccine lead for immunization systems at the WHO in Geneva. Even after a country attains elimination — defined as the absence of the continuous transmission of measles for a year or more — maintenance programs must be relentless, says Robert Linkins, a global measles expert at the U.S. Centers for Disease Control and Prevention in Atlanta. “Kids are born every day needing vaccines.… You have to keep up.” The Americas is learning this lesson the hard way. In 2016, the region became the first to eliminate measles after its 35 countries immunized 95 percent or more of their populations (SN Online: 9/27/16). That’s the point at which herd immunity can keep safe those who aren’t immunized (often for health reasons or because they are too young). But across the region, vaccination rates have since dipped, and outbreaks in Brazil and Venezuela have cost the region its elimination status, according to a May 10 report in Science. Reasons for recent failures vary across the world. Political instability, conflict and poverty can lead to shortages of vaccines (which must be refrigerated) and clinic closings.
5-21-19 Signs of red pigment were spotted in a fossil for the first time
The 3-million-year-old mouse was reddish-brown on its back and sides. The 3-million-year-old mouse wore red. For the first time, chemical traces of red pigment have been detected in a fossil, scientists say. Using a technique called X-ray spectroscopy, researchers led by paleontologist Phillip Manning at the University of Manchester in England searched the fossil for a chemical signature associated with pheomelanin, the pigment responsible for reddish-brown fur or feathers. The team had already worked out which unique combination of chemical components stand for pheomelanin and for eumelanin, a dark brown or black pigment, by mapping out where trace metals such as zinc and copper bonded to organic molecules in the pigments of modern bird feathers. Pheomelanin, they determined, occurs where zinc binds to organic sulfur molecules. Mapping where both zinc and sulfur molecules occurred on the mouse’s body revealed that the ancient field mouse had reddish-brown fur on its back and sides, the team reports online May 21 in Nature Communications. Pheomelanin is difficult to preserve, though scientists previously have found hints of the red color in ancient critters. Microstructures identified in some exceptionally well-preserved fossils may be pigment-bearing pods called melanosomes; the shapes of the pods in modern animals are linked to the types of pigment they contain (SN: 11/26/16, p. 24). For example, sausage-shaped melanosomes contain eumelanin, while meatball-shaped melanosomes hold pheomelanin. And an armored dinosaur that lived 110 million years ago may have had some red on it: Scientists detected benzothiazole in its fossil, a by-product of pheomelanin that can form when the pigment breaks down (SN Online: 8/3/17).
5-20-19 DNA database opts a million people out from police searches
A major DNA database that has been pivotal in solving US cold crime cases has blocked law enforcement access to the profiles of a million people, in a setback for investigators and a victory for campaigners. GEDMatch, which allows people to trace their relatives by uploading DNA results from consumer genetics services such as 23andMe, helped police catch a Californian serial killer last year, decades after the murders. But the site changed its terms and conditions on Saturday to opt out its million users from searches by law enforcement, in what genealogy geneticists called a “stunning reversal” of its position. Officers have used a combination of matching genetic samples from the site with traditional genealogy techniques to build family trees and find suspects in cold cases. Around 50 such cases have been solved using GEDMatch, according to Christi Guerrini of Baylor College of Medicine. Members will now have to actively opt in for police to use their data, which several people on social media said they would do to help solve crimes. The move came after site made an exemption allowing Utah police to use the service for a violent assault. Previously, law enforcement agencies were only permitted to search the site for murder or sexual assault cases. Curtis Rogers, one of the site’s founders, said: “The Utah case in which a 71-year old woman was beaten and left for dead and which some people felt was an exception to our vicious crime clause, made us rethink our terms of service policy. The opt-in for law enforcement use is one result of this thinking.” The change was welcomed by genetic genealogists. Judy Russell, who blogs as The Legal Geneaologist, said the change “leaves the entire field on firmer ethical ground.” (Webmaster's comment: But lets violent criminals get away with it. Let's use DNA to put violent criminals away for good!)
5-20-19 Sabre-toothed cats bit rivals in the head and punctured their skulls
Sabre-toothed cats may have used their fearsome canine teeth to bite their rivals in the head, puncturing their skulls and probably killing them. This seems to be the best explanation for two separate sabre-toothed cat skulls sporting tooth-shaped holes. The long-toothed cats roamed the world for over 40 million years before the last ones vanished 11,000 years ago. Although the canine teeth are dramatic, some palaeontologists think they were largely for show. They are so long and narrow, the argument goes, they must have been fragile and would have broken if used to bite into bone. “Others even suggested that they were useless for hunting and only served for exhibiting to females,” says Federico Agnolin of the Bernardino Rivadavia Natural Sciences Argentine Museum in Buenos Aires. Agnolin and his colleagues studied two skulls of Smilodon populator, one of the best known species, discovered at separate sites in Argentina. Both skulls have holes, shaped like pointy ovals, near where the forehead meets the nose. It looks like the wounds were inflicted by the famous teeth. “The shape and the size of the holes are identical,” says Agnolin. To confirm this, the team took a third sabre-toothed cat skull and inserted its canines into the holes on each of the other skills. “The canines of the specimen entered perfectly through the holes, matching the shape and size,” says Agnolin. The team says the best explanation for each skull is that the wounds were inflicted by another sabre-toothed cat during a fight. In both cases, this was probably fatal, says Agnolin. It is conceivable that the cats were actually kicked in the head by hoofed prey, but he says that would make different-shaped holes.
5-20-19 Some baby dinosaurs crawled before learning to walk on two legs
It takes a few months of crawling until babies can stand up on their own and this might be true for some dinosaurs too. A fossil analysis has found a dinosaur that may have walked on all fours as a child and then shifted to two legs once it grew up. Humans are probably the only animals today that transition from moving on all fours to two feet only during their lifetime, says Andrew Cuff at the Royal Veterinary College in Hertfordshire. “Finding another example, especially in an extinct and very different group like dinosaurs, is exciting,” he says. Mussaurus patagonicus lived about 200 million years ago in present day Argentina. An adult M. patagonicus had a long neck and tail, and could reach 1 tonne in body weight. However, a newly hatched M. patagonicus was as tiny as a newborn chick, weighing only about 60 grams. To see whether the animal’s body posture changed with its size, Cuff and his colleagues used M. patagonicus fossils to reconstruct 3D models of the dinosaur at three life stages: hatchling, one-year-old juvenile, and adult. One feature that determines whether an animal can walk primarily on two feet is its centre of gravity. The point has to be above its two hindlegs rather than further forward. The team found as a hatchling, M. patagonicus’s centre of gravity was located in the middle of its back, in front of the legs, meaning hatchlings had to stand on all fours in order to remain balanced. As M. patagonicus became bigger its centre of gravity gradually shifted towards the rear, with its tail playing a large role. An adult M. patagonicus’s centre of gravity was very close to its hips above its legs, and could therefore walk bipedally.
5-20-19 This early sauropod went from walking on four legs to two as it grew
Center of mass shifts led to a rare change in walking style for a long-necked dinosaur relative. Most long-necked sauropods lumbered on four legs all their lives to support their titanic bulk. But an early relative of such behemoths as Brachiosaurus made the unusual transition from walking on four legs to two as it grew, a new study shows. Diminutive at hatching, Mussaurus patagonicus (which means “mouse lizard”) began life walking on all fours. But by the time the 200-million-year-old plant eater reached its 6-meter-long adult size, it roamed what’s now Argentina on two legs. The changing length of M. patagonicus’s arm bones relative to its body and its inward facing-palms as an adult had hinted at the transition. But for the first time, computer simulations based on a rich fossil record show how a shift in the creature’s center of gravity as it grew enabled a change to bipedal walking, researchers report May 20 in Scientific Reports. Researchers took CT scans of fossil bones from six individual M. patagonicus — covering different stages of the species’ development, from 60-gram hatchlings the size of baby chickens to 1.5 metric ton adults the size of rhinoceroses. The researchers added virtual flesh to digitized bones to create 3-D models that allowed them to estimate both the weight and center of gravity of M. patagonicus at many different stages of its life. Reconstructions of the hatchlings showed that the creature’s center of mass was so far forward that the dinosaurs could move around only by walking on all four legs, says Andrew Cuff, a paleontologist of the Structure and Motion Laboratory of the Royal Veterinary College in Hatfield, England.
5-19-19 How your DNA could solve a murder
Genetic information from ancestry databases is being used to solve murders and identify bodies. Is this the end of DNA privacy? In the year since the arrest of the man believed to be the notorious Golden State Killer, the world of criminal investigation has been radically transformed. Using an unconventional technique that relies on DNA submitted to online genealogy sites, investigators have solved dozens of violent crimes, in many cases decades after they hit dead ends. Experts believe the technique could be used to revive investigations into a vast number of cases that have gone cold across the country, including at least 100,000 unsolved major violent crimes and 40,000 unidentified bodies. Many have called it a revolutionary new technology. But credit for this method largely belongs to a number of mostly female, mostly retired family-history lovers who tried for years to convince law enforcement officials that their techniques could be used for more than locating the biological parents of adoptees. One was Diane Harman Hoog, 78, director of education at DNA Adoption, who realized in 2013 that she could apply the techniques she was using to identify two bodies she had read about in a Seattle newspaper. "This is too complicated," she said she was told when she reached out to a detective. Four years later, Margaret Press, 72, a retired computer programmer and skilled family-tree builder in California, tried to help her local sheriff with a similar case. No one would return her calls. Fast-forward to April 25, 2018, the day that a gaggle of California prosecutors announced that an "innovative DNA technology" had been used in the Golden State Killer case. The innovator was Barbara Rae-Venter, a genetic genealogist who had uploaded crime scene DNA to GEDmatch.com, a low-key genealogical research site run out of a little yellow house in Florida. Rae-Venter, 70, and her team soon found a suspect by using the genetic and family-tree data provided by his cousins. And that was how a former police officer, Joseph DeAngelo, came to be charged with 26 counts of murder and kidnapping in connection with scores of rapes and killings that were committed across California in the 1970s and '80s. In interview after interview, Paul Holes, a determined investigator who had spent decades chasing false leads, rejoiced in his decision to involve Rae-Venter. "Barbara really braved the pass," said CeCe Moore, a genetic genealogist who was also among the first to see the potential in the technique. Within a few weeks of the announcement, she began working with Parabon, a forensic-consulting firm.
5-19-19 How allergens in pollen help plants do more than make you sneeze
Clouds of the grains may be easy to hate, but they’re crucial for plant health. “Are plants trying to kill us?” allergy sufferers often ask Deborah Devis. A plant molecular geneticist at the University of Adelaide’s Waite campus in Australia, Devis should know the answer better than most. She is chugging through the last few months of a Ph.D. that involves predicting how grasses use pollen proteins that make people sneeze, wheeze and weep for days on end. What’s known so far about what allergens do for pollens shed by grasses, trees and even mosses has nothing to do with revenge against a primate likely to attack them with mowers and other sharp tools, she says. Instead, plants are just trying to live like the rest of us. “In most cases,” she says, “the allergen proteins are absolutely essential.” To understand why, a refresher on some basics of plant sex is helpful. A pollen grain’s stripped-down mission is to carry male sex cells to female parts of flowers. It’s a chancy and dangerous job. But evolution has honed formidable chemistry that protects the grains’ travels and fertilization itself. For instance, the outer coat of a pollen grain contains the outstandingly tough sporopollenin, which can last thousands of years, says Hannah Banks of Kew Gardens in London. Just to clean debris off the coat, researchers routinely boil pollen in a mixture of sulfuric and acetic acid.
5-18-19 Scientists have finally worked out what screaming sounds like
What’s in a scream? The vocalisations people identify as screams share certain sound qualities – a kind of acoustic DNA that tells a listener’s ear that what they’re hearing is a scream, even if it isn’t. “Evolutionarily, screams likely originally functioned to startle attacking predators. Research on screams has the potential to help us understand the evolution of emotional communication,” says Jay Schwartz at Emory University. He and his colleagues asked 181 volunteers to listen to 75 vocal sounds that included laughter, crying, moans, groans, and yells from acted sources – like television or movies – and more natural sources, such as a YouTube video of a child opening a present and screaming in delight. The listeners indicated whether or not each sound was something they considered a scream. “We did not provide any type of definition for a scream because we were trying to get at what is it in people’s minds that distinguishes a scream from other types of vocalisations,” says Schwartz, who presented his work at a meeting of the Acoustical Society of America on 14 May. When they analysed the sound files, they found that the ones categorised as screams had acoustic similarities. People were more likely to consider a sound a scream if it was higher in pitch, and had a varied change in pitch, first moving up and then down at the end. For example, 100 per cent of the participants agreed that this sound was a scream. Sounds that maintained a more steady pitch were less likely to be perceived as a scream. Only 58 per cent of listeners thought this was a scream.
5-17-19 Key parts of a fruit fly’s genetic makeup have finally been decoded
Jumping genes in chromosomes may ensure DNA gets where it needs to go when cells divide. Some of the most important chapters in fruit flies’ genetic instruction book have finally been decoded. For the first time, researchers have deciphered, or sequenced, the genetic makeup of all of a multicellular organism’s centromeres — and discovered stretches of DNA that may be key in divvying up chromosomes. Errors in doing that job can lead to cancer, birth defects or death. The team reported the achievement May 14 in PLOS Biology. Centromeres, which give most chromosomes their characteristic X shape, help move chromosomes in dividing cells. “The chromosome is a bus, and our DNA and genes are the passengers. The centromere is the bus driver,” says Beth Sullivan, a geneticist and centromere biologist at Duke University School of Medicine not involved in the study. “It’s what moves the chromosome, after the DNA has been copied, into new daughter cells.” Until now, scientists have known very little about these genetic bus drivers. Some centromeres from corn, horses, yeast and other fungi — and one human one that drives the Y chromosome — have been characterized. But mostly what scientists knew about centromeres is that they are incredibly long stretches of repetitive DNA. Although scientists reported in 2000 that they’d finished reading the entire Drosophila melanogaster instruction book, or genome, in truth, researchers had skipped over the flies’ centromeres and other repetitive DNA. (The human genome is also not really complete; human centromeres, except for that of the Y chromosome, are still mysteries.)
5-17-19 Compulsory vaccines are needed to keep measles under control in the UK
The UK should consider introducing compulsory measles vaccinations before children start school, according to a team of researchers in Italy. Their analysis of international measles data suggests that current vaccination policies are not enough to keep the virus under control. The team looked at vaccination trends in multiple countries, including the UK, US, Australia, and Ireland. They concluded that, in order to keep the percentage of the population susceptible to catching measles under 7.5 per cent by 2050 – the level at which measles is regarded as eliminated – further action is needed. Either far more people need to be vaccinated, or a schools policy should be brought in, say the team. In their analysis, they found that an estimated 3.7 per cent of the UK population across all ages was susceptible to measles in 2018. Without any change to vaccination policies, this is expected to increase to more than 5.5 per cent by 2050. But compulsory vaccination at school entry, in addition to current routine immunisation programs, would enable the UK, Ireland and US to reach stable herd immunity levels in the coming decades, says team member Stefano Merler, of the Fondazione Bruno Kessler in Trento. There were 966 measles cases in England last year, up from 259 in 2017. Anti-vaccination groups may be behind a number of parents choosing not to vaccinate their children with the combined measles, mumps and rubella vaccine (MMR). “Vaccine rejection is a serious and growing public health time-bomb,” says Simon Stevens, of NHS England. Social media firms should have a zero-tolerance approach towards dangerous and inaccurate stories, he says.
5-17-19 Vaccines may help bats fight white nose syndrome
Oral inoculation would spread from bat to bat through nuzzles. Oral vaccines could give wild bats a better chance at surviving white nose syndrome, the fungal disease that has ravaged bat colonies in North America. In lab tests conducted on captured little brown bats, vaccination led to fewer infected bats developing lesions and more of the bats surviving, researchers report May 1 Scientific Reports. White nose syndrome, caused by the fungus Pseudogymnoascus destructans, has killed around 7 million bats in the United States since 2006. In some regions, the disease cut some bat colonies by 75 percent. The white fuzz grows across bats’ skin when the animals hibernate, eventually making them wake up, fly around and waste energy needed to survive winter (SN Online: 1/29/16). “It’s just devastating to some bat populations,” says veterinarian Elizabeth Falendysz at the U.S. Geological Survey National Wildlife Health Center in Madison, Wisc. Falendysz and colleagues made two vaccines against the fungus by implanting raccoon poxviruses with DNA instructions for making one of two fungal proteins, in order to trick the bats’ immune system into recognizing and fighting the fungus. (Vaccines that helped in rabies eradication efforts and in fighting plague in prairie dogs rely on the same mechanism.) Wild little brown bats (Myotis lucifugus) were vaccinated before being exposed to the fungus. Of 10 bats given a combination of both vaccines, only one developed lesions within the experiment’s 100-day hibernation period. Because little brown bats don’t do well in captivity, the team struggled with dwindling sample sizes, so it was hard to compare these numbers to other individual treatments. But 14 of the other 23 bats, or 61 percent, that didn’t get this vaccine combo developed lesions.
5-17-19 Cannabis plant evolved super high (on the Tibetan Plateau)
Cannabis may have had high origins. Where the plant comes from has been a bit of a mystery, but analysis of ancient pollen now suggests it evolved some 3 kilometres above sea level on the Tibetan Plateau. Intriguingly, this site is only a few hundred kilometres from a cave that researchers recently announced was once home to our ancient Denisovan cousins. Humans began exploiting cannabis deep in prehistory. Its seeds are a good source of protein and fatty acids, while fibres from its stems can be spun into yarn and made into textiles. Its flowers, meanwhile, are a source of cannabinoids which have been used as a drug for at least 2700 years. To find out where the plant evolved, John McPartland at the University of Vermont and his colleagues searched through scientific studies to pick out archaeological and geological sites across Asia where cannabis pollen has been found. Identifying cannabis pollen isn’t easy because it looks identical to the pollen of a closely related plant called the common hop, which happens to be used for flavouring beer. But McPartland and his colleagues believe it is possible to work out which species the pollen belongs to by considering the other pollen present at an archaeological site. This is because cannabis lives on open grassy steppes, so its pollen usually occurs with the pollen of steppe plants. The common hop, however, grows mostly in woodlands, so its pollen typically occurs with tree pollen. When McPartland and his colleagues applied this rationale, they discovered that the earliest occurrence of cannabis pollen in the geological and archaeological record is in northern China and southern Russia. From the distribution of the pollen, the team concluded that cannabis probably emerged on the Tibetan Plateau in the vicinity of Qinghai Lake, which is about 3200 metres above sea level.
5-16-19 Does eating ultraprocessed food affect weight gain? It’s complicated
A new diet study is highly controlled, but still has conflicting results. Nutrition advice can be confusing. Studies that bolster the health benefits of a food or nutrient seem inevitably to be followed by other work undercutting the good news. One reason for the muddle is that nutrition studies sometimes depend on people’s self-reporting of past meals. And because people may forget or even lie about what they’ve been consuming, that data can be flawed, creating conflicting reports about what’s healthy and what’s not, research has shown. But even if people had a photographic memory of all of their meals, that alone wouldn’t provide enough information. How bodies react to and process food can vary widely from person to person and be dependent on genes, the microbes that live inside the gut, a person’s current health, what the food contains or even how it was made (SN: 1/9/16, p. 8). “The problem is that nutrition research is rocket science,” says David Ludwig, a pediatric endocrinologist at Boston Children’s Hospital. “There are potentially thousands of different nutrients and factors in food that could influence our biology or our senses as we eat. Those can interact in unpredictable and complicated ways.” Given the complexity that comes with researching diet, one approach is to study people in a controlled environment, so that researchers know exactly what the participants are eating. A study that tied eating highly processed foods to weight gain, published online May 16 in Cell Metabolism, did just that. Here’s what the researchers learned — and what they still can’t answer.
5-16-19 Psychedelic parenting: The sad new trend of microdosing moms
Are mind-altering drugs a parenting godsend or a dangerous crutch? Parents who struggle to cope with the daily grind of raising kids are turning to mind-altering, illegal drugs. According to a recent report from The Guardian, a small but growing number of child-rearers in the U.S. and U.K. are now "microdosing": taking teensy amounts of psychedelic substances — mostly ground up, home-grown magic mushrooms or LSD — to help ease the drudgery of parenting. As one shroom-consuming mom put it: "You don't feel high, just … better." Moms and dads may be new to microdosing, but the trend has been bubbling for years in Silicon Valley. The tech set claim that taking 10 to 20 micrograms of LSD every few days (a trip-inducing dose is around 100 micrograms) makes them more creative and focused. Parents say it makes them feel more engaged and patient with their kids. In principle, I'm not against parents adding feel-good molecules to their armory of coping mechanisms. I, for one, rarely turn down an invitation to a moms' happy hour. But self-medicating, however minimally, with under-researched chemicals could be dangerous in ways we might not yet realize. My larger concern is that microdosing is just the latest manifestation of parents pursuing that impossible goal of having it all. The science behind mircodosing is currently limited and wobbly at best. One study published in February followed 98 microdosers who were already using drugs classed as psychedelics, which includes LSD and psilocybin, the active ingredient in magic mushrooms. While all participants anticipated the benefits of microdosing to be "large and wide-ranging," most experienced only some positive changes, such as increased focus and reduced stress and depression. There was no bump in creativity or life satisfaction. And, six weeks in, the study actually found a small increase in neuroticism. Clearly, we need more quality studies on mircrodosing, and to approach this potential Pandora's box of "happy" chemicals with extreme caution. Luckily, researchers at Imperial College London are looking into this, conducting the world's first placebo-controlled study of the microdosing and its effects.
5-16-19 Centre for Cancer Drug Discovery to focus on anti-evolution treatments
All treatments for cancer should be designed to prevent tumours evolving resistance, because drug-resistant tumours are what kill most people, says Paul Workman, head of the Institute of Cancer Research (ICR) in the UK. To make this happen, the ICR is setting up a £78 million Centre for Cancer Drug Discovery in London that will bring together researchers from different disciplines to focus on creating anti-evolution treatments. “We are hugely excited about it,” Workman told a press briefing at the Science Media Centre. “The biggest challenge in cancer is drug resistance.” Cancers develop when genetic mutations destroy the mechanisms in cells that normally limit growth. As tumours grow, these cells continue to mutate and become more diverse. When someone with cancer is given a drug, it may be very effective at first, killing most of the cells in the tumour. But if just a few cells out of the billions in a tumour have a mutation that makes them resistant to that drug, they will survive and keep growing. This is natural selection – exactly the same process that drives the evolution of plants, animals, bacteria and viruses. “Cancers evolve very rapidly over a short space of time to become resistant, leading to the vast majority of cancer deaths,” says Workman. Thanks to new technologies such as single-cell genome sequencing, we can now study this process in action. But cancer researchers and doctors haven’t yet put this understanding at the heart of all they do. “We need a culture shift in how we develop drugs,” says Olivia Rossanese, who will be head of biology in the new centre.
5-16-19 Artificial life form given 'synthetic DNA'
UK scientists have created an artificial version of the stomach bug E. coli that is based on an entirely synthetic form of DNA. At the same time, Syn61 as they are calling it, has had its genetic code significantly redesigned. It's been done in a manner that will pave the way for designer bacteria that could manufacture new catalysts, drugs, proteins and materials. Other scientists working in synthetic biology have hailed the development. Genetic engineer Prof George Church, from Harvard University, US, has hailed the work as "a major breakthough". Dr Tom Ellis, a reader in synthetic biology at Imperial College London called it super-impressive. Syn61's 4 million genetic letters make this the largest entire genome to be synthesised from scratch. They were ordered in short segments from a laboratory supplies company, before being assembled into half-million-letter lengths in yeast cells by natural cellular machinery. At this point, the genome engineers' job became a bit like a railway engineer's maintenance programme - replacing the E. coli genome piecewise - section by section - rather than all at once. "The bacterial chromosome is so big," team leader Jason Chin told the BBC, "we needed an approach that would let us see what had gone wrong if there had been any mistakes along the way." So it was only after each half-million-letter segment had been tested in partially synthetic bacteria that the eight segments were brought together in Syn61. The approach is more cautious than that used by bio-entrepreneur, Craig Venter, whose microbial replicant based on the tiny organism Mycoplasma genitaliumwas presented to the world in 2010. That was a milestone, Tom Ellis recalls, but consumed the efforts over many years of an entire institute, set up, run and named by Venter. The new work was conducted by a small team at Cambridge's world-famous Laboratory for Molecular Biology, and could readily be scaled up to bigger genomes in any well equipped lab, according to Dr Chin. In the event, the team found only four mistakes out of the entire four million synthesised genetic letters, and they were easily corrected.
5-16-19 The quest for better snakebite treatments gets a funding boost
A multimillion-pound programme has been launched to improve treatment for snakebites, which are thought to kill up to 138,000 people each year. Treatments for snakebites can be expensive or ineffective, a problem that disproportionately affects people living in the world’s poorest places. Current methods for making antivenom involve using antibodies extracted from horses – a process that hasn’t changed since the 19th century and carries a high risk of contamination and adverse reactions in patients. Of those who survive venomous bites each year, 400,000 people develop life-changing injuries, including amputations. To tackle this, the Wellcome Trust has announced £80 million in funding for a new research programme on snakebite treatments. The programme aims to make antivenoms better, safer and cheaper. “Snakebite is – or should be – a treatable condition. With access to the right antivenom there is a high chance of survival. While people will always be bitten by venomous snakes, there is no reason so many should die,” says Mike Turner, of the Wellcome Trust. The World Health Organization is expected to publish a strategy next week for halving the number of deaths and disabilities from snakebites by 2030.
5-15-19 Does population genetics have a racism problem, even today?
Efforts to group us by our genes are arbitrary and encourage the subtle return of race within mainstream science, argues Angela Saini. THE end of the second world war was meant to have spelled the death of race science. Until the 1930s, it had been relatively acceptable for biologists and anthropologists to believe in innate differences between races. Many assumed that certain groups were superior to others. It was only after the war and the Holocaust that the world finally turned its back on this dangerous field of research. People thought about race differently following the war. Anthropologists showed that most of what we think of as racial difference is in fact cultural and linguistic difference. Geneticists, starting with Richard Lewontin in 1972, have shown that more than 90 per cent of the genetic variation we see between humans lies within the racial categories we use. Being of the same race doesn’t necessarily make two people more genetically similar to each other than either of them would be to someone of another race. Race is today described as a social construct, its study confined to the social sciences so we can understand the effects of historical and modern-day discrimination. The handful of scientists who have continued to insist publicly on the existence of biological races have often been on the margins of respectability. There was William Shockley, the Nobel prize-winning physicist at Stanford University in California who wanted black women in the US to be voluntarily sterilised. Then there was Arthur Jensen, a psychologist at the University of California, Berkeley, who claimed that black people had innately lower intelligence levels than white people. We think of Jensen and Shockley as exceptions. We assume that race has been purged from science. But has it?
5-16-19 Peasants in medieval England ate a diet of meat stew and cheese
Medieval peasants mainly ate stews of meat and vegetables, along with dairy products such as cheese, according to a study of old cooking pots. Researchers analysed food residues from the remains of cooking pots found at the small medieval village of West Cotton in Northamptonshire. The pottery covers a period of around 500 years during the Middle Ages. By identifying the lipids, fats, oils and natural waxes on the ceramics, the team found that stews of mutton and beef with vegetables such as cabbage and leek were a mainstay of the medieval peasant diet. However, dairy products such as cheese also played an important role. “All too often in history, the detail of the everyday life of ordinary people is unknown,” says Julie Dunne, at the University of Bristol, UK. “Much is known of the medieval dietary practices of the nobility and ecclesiastical institutions, but less about what foods the medieval peasantry consumed.” Dunne and her colleagues also examined a range of historical documents for their study, finding that medieval peasants ate meat, fish, dairy products, fruit and vegetables. The team say that, prior to this study, there was little direct evidence that this was the case.
5-15-19 Hearing device picks out right voice from a crowd by reading your mind
Sometimes it is hard to make out what people are saying in a noisy crowded environment. A device that reads your mind to work out which voices to amplify may be able to help. The experimental device can separate two or three different voices of equal loudness in real time. It can then work out which voice someone is trying to listen to from their brainwaves and amplify that voice. The device, created by Nima Mesgarani at Columbia University in New York, is a step towards creating smart hearing aids that solve the classic cocktail party problem — how to separate voices in a crowd. First, Mesgarani’s team worked on a system that could separate the voices of two or three people speaking into a single microphone at the same loudness. Several big companies like Google and Amazon have developed similar AI-based ways of doing this to improve voice assistants like Alexa. But these systems separate voices after people have finished speaking, Mesgarani says. His system works in real time, as people are speaking. Next, the team played recordings of people telling stories to three people who were in hospital with electrodes placed into their brains to monitor epileptic seizures. In 2012, Mesgarani showed that the brainwaves in a certain part of the auditory cortex can reveal which of several voices a person is focusing on. By monitoring the brainwaves of the three volunteers, the hearing device could tell which voice people were listening to and selectively amplify just that voice. When the volunteers were asked to switch attention to a different voice, the device could detect the shift and respond.
5-15-19 Did we split from Neanderthals 400,000 years earlier than we thought?
An analysis of fossil teeth suggests that the shared ancestor of modern humans and our Neanderthal cousins may have lived more than 800,000 years ago. Previous studies have used DNA to calculate how long ago these two types of humans split from each other, estimating this to have taken place around 400,000 years ago. But fossils from the cave site of Sima de los Huesos, in Spain, don’t fit with this estimate. The hominin remains discovered there are thought to be those of early Neanderthals, but dating indicates they are around 430,000 years old, which hints that the most recent common ancestor of Neanderthals and modern humans must have lived before this time. To estimate how much earlier this ancestor may have lived, Aida Gómez-Robles of University College London analysed the shape of these fossilised teeth and the teeth of seven other types of hominin, including Australopithecus afarensis and Paranthropus robustus, and compared how they have changed over time. Because these chewing teeth appear to evolve steadily in hominin species, Gómez-Robles could use modelling to estimate when different branches of the human family tree must have had to split from each other to lead to the different kinds of fossil teeth. The only way the teeth found at Sima de los Huesos would have had time to evolve particular features would have been for Neanderthals and early humans to have diverged at least 800,000 years ago, she says. If Gómez-Robles is right, it would suggest that Homo heidelbergensis, an ancient human that lived 700,000 to 300,000 years ago, could be ruled out as a possible common ancestor with the Neanderthals.
5-15-19 Fossil teeth push the human-Neandertal split back to about 1 million years ago
A new study estimates the age of these hominids’ last common ancestor. People and Neandertals separated from a common ancestor more than 800,000 years ago — much earlier than many researchers had thought. That conclusion, published online May 15 in Science Advances, stems from an analysis of early fossilized Neandertal teeth found at a Spanish site called Sima de los Huesos. During hominid evolution, tooth crowns changed in size and shape at a steady rate, says Aida Gómez-Robles, a paleoanthropologist at University College London. The Neandertal teeth, which date to around 430,000 years ago, could have evolved their distinctive shapes at a pace typical of other hominids only if Neandertals originated between 800,000 and 1.2 million years ago, she finds. Neandertals existed after around 1 million years ago, “there wasn’t enough time for Neandertal teeth to change at the rate [teeth] do in other parts of the human family tree” in order to end up looking like the Spanish finds, says palaeoanthropologist Bernard Wood of George Washington University in Washington, D.C. Many researchers have presumed that a species dubbed Homo heidelbergensis, thought to have inhabited Africa and Europe, originated around 700,000 years ago and gave rise to an ancestor of both Neandertals and Homo sapiens by roughly 400,000 years ago. Genetic evidence that Sima de los Huesos fossils came from Neandertals raised suspicions that a common ancestor with H. sapiens existed well before that (SN Online: 3/14/16). Recent Neandertal DNA studies place that common ancestor at between 550,000 and 765,000 years old. But those results rest on contested estimates of how fast and how consistently genetic changes accumulated over time.
5-14-19 Free-floating DNA to reveal the health of river and lake ecosystems
The mix of DNA floating in rivers and lakes will finally be used to monitor the state of aquatic ecosystems, after years of tests to show that the technique works. Conventionally, aquatic life is monitored by capturing organisms, either by using nets or scraping under boulders, for examination. These techniques are time-consuming, can harm species and require skilled ecologists. Monitoring fish typically involves using electricity to stun them, which can sometimes prove fatal. But these techniques could be replaced by simply taking a water sample and analysing the DNA in it. This environmental DNA (eDNA) comes from the cells, waste and blood of organisms. Thanks to advances in cheap, fast genetic sequencing and in our ability to identify which species the DNA comes from, England’s Environment Agency plans to start using eDNA to monitor fish next year. “eDNA is no longer a concept,” says Kerry Walsh at the Environment Agency. The agency has a responsibility to monitor the health of rivers and lakes, and the number of species living in these environments can indicate this. The agency began exploring the use of eDNA seven years ago in a bid to make efficiency savings, and now its proof of concept tests suggest that eDNA can be more accurate than established techniques. In a recent study at Lake Windermere in Cumbria, eDNA analysis identified DNA from 14 of the 16 species of fish that have ever been recorded there. This is about three times as many species as are usually detected using conventional measures, and included pike and eel. “Some fish become aware of nets and stay away. Whereas with eDNA it’s in the water, it’s mixed. Fish are great because they are slimy and releasing eDNA all the time,” says Walsh.
5-14-19 NHS hospital to trial genetic analysis for blood pressure patients
A hundred people undergoing treatment at a UK hospital are to get their DNA analysed in a pioneering trial. Around 85,000 people with rare disorders in the UK have already had their genomes sequenced through the National Health Service as part of the 100,000 Genomes Project. Now, University College Hospital in London plans to invite around 100 people attending its blood pressure clinic to undergo genetic analysis. The trial aims to test how useful such analysis might be in a busy, hospital environment, says Reecha Sofat of University College London. The data may also inform future drug development. Sofat says that, currently, she can rarely tell her hypertension patients why they have high blood pressure, but genomics might one day change this. More than 500 individual genetic variants have previously been pinpointed as contributing to high blood pressure. A big part of the trial will be seeing whether it makes any difference to know what combination of these variants someone has. If a person is told they have a high genetic risk for hypertension, for instance, will they be better at taking their medicine? It is also hoped that the programme could help clinicians provide more tailored treatment. Although the trial is small, the team wants to see if the approach could scale up to work in a hospital that sees more than a million patients a year. One important benefit of doing genetic testing in a hospital in an ethnically diverse city such as London is that it could start to address the fact that population-wide genetic studies have largely involved people who are white and of European descent.
5-14-19 Peacock spiders’ superblack spots reflect just 0.5 percent of light
New images reveal microscopic structures that manipulate light to create the dark patches. Male peacock spiders know how to put on a show for potential mates, with dancing and a bit of optical trickery. Microscopic bumps on the arachnids’ exoskeletons make velvety black areas look darker than a typical black by manipulating light. This architecture reflects less than 0.5 percent of light, researchers report May 15 in the Proceedings of the Royal Society B. The ultradark spots, found near vivid colors on the spiders’ abdomens, create an “optical illusion that the colors are so bright … they're practically glowing,” says Harvard University evolutionary biologist Dakota McCoy. Male peacock spiders swing and shake their brilliantly colored abdomens during elaborate mating displays. Pigments produce the red and yellow hues, but blues and purples come from light interacting with hairlike scales (SN: 09/17/16, p. 32). Black areas on the spiders contain pigment, too. But scanning electron microscopy also revealed a landscape of tiny bumps in superblack patches on Maratus speciosus and M. karrie peacock spiders. In contrast, all-black, closely related Cylistella spiders have a smooth texture. Scanning electron microscope images show bumps, which manipulate incoming light, in superblack patches on the abdomens of two species of peacock spiders. While Maratus speciosus (left) has only bumps, M. karrie (middle) also sports spiky scales that limit reflection by scattering and absorbing light. A Cylistella spider (right) has a smoother surface, which results in an ordinary black appearance.
5-14-19 US jury awards $2bn damages in Roundup weedkiller cancer claim
A jury in California has awarded more than $2bn (£1.5bn) to a couple who said the weedkiller Roundup was responsible for their cancer. It is the third time that the German pharmaceutical group Bayer has been ordered to pay damages over its glyphosate-based herbicide. The jury ruled the company had acted negligently, failing to warn of the risks associated with the product. Bayer denied the allegations. It insists that Roundup is safe to use. The company acquired the product last year as part of a $66bn takeover of US rival Monsanto. On Monday, a jury in Oakland, California, said Bayer was liable for plaintiffs Alva and Alberta Pilliod contracting non-Hodgkin's lymphoma. Lawyers for the couple, who are in their 70s, described the damages award as "historic". "The jury saw for themselves internal company documents demonstrating that, from day one, Monsanto has never had any interest in finding out whether Roundup is safe," said their counsel, Brent Wisner. The jury awarded each of them $1bn in punitive damages as well as a total of $55m in compensatory damages. In a statement, Bayer said it was disappointed with the verdict and would appeal. It called the jury's decision "excessive and unjustifiable" adding that both Alva and Alberta Pilliod had histories of illnesses that were known risk factors for non-Hodgkin's lymphoma. The company insists that decades of studies have shown glyphosate and Roundup to be safe for human use. Glyphosate was developed by Monsanto in the US in the 1970s and has become one of the most widely used ingredients in weed killers worldwide. But Bayer now faces more than 13,400 US lawsuits over Roundup's alleged cancer risk. In March, a jury in San Francisco awarded $80m to another Californian man after finding that Roundup had caused his cancer. Last August, another Californian man was awarded $289m after a jury also found Roundup caused his cancer. (Webmaster's comment: It's about time, but millions of lives too late!)
5-14-19 Shining a UV light on a special glue can repair heart wounds
Here comes a glue that can mend a broken heart. A new material can repair cuts in pig hearts without using any stitches, and it can be absorbed by the body over time. Hongwei Ouyang at Zhejiang University in China and his colleagues used polymers and water to create a glue that mimics the composition of the viscous gel of proteins that help with wound repair in animals. Once activated by UV light, the glue reacts with proteins in biological tissues to form tight chemical bonds, sticking to tissue surface tightly and sealing the wound. The team tested the technique in four pigs. They punctured a hole in the left ventricle of each heart using a needle. Then the glue was applied to the wounds followed by a dose of UV light. In less than 30 seconds, the bleeding stopped. After two weeks, the team dissected the pigs and found no leaks between the gel and their heart tissue, and very little inflammation at the wounds, says Ouyang. “No current existing clinical products can stop operative heart bleeding so quick and efficiently,” says Ouyang. The bonds are strong enough to withstand blood pressure twice the normal levels, meaning it won’t burst when the heart contracts and pumps out blood. To test the gel’s biodegradability, the team injected the gel into rats underneath their skin. Only about 20 per cent of the glue remained after eight weeks and no adverse reaction was observed.
5-14-19 Tweaking one gene with CRISPR switched the way a snail shell spirals
The first gene-edited snails confirm which gene is responsible for how a shell swirls. A genetic spin doctor sets snail shells to swirl clockwise, new research confirms. And the twist in this story comes at the beginning — when snail embryos are just single cells. Though most pond snails (Lymnaea stagnalis) have shells that coil clockwise, a few have taken a left turn, curling counterclockwise. Researchers had strong evidence that a mutation in a gene called Lsdia1 caused the counterrevolution, but there was a possibility that the similar Lsdia2 gene might be involved. The two genes are 89.4 percent identical, so teasing out which was responsible was tricky. Working at the Tokyo University of Science, chemist and biologist Reiko Kuroda and colleague Masanori Abe snipped Lsdia1 with the gene editor CRISPR/Cas9. The snip made a mutation in the gene that could be passed on to future generations. Snails that inherited two edited copies of the gene developed left-coiling, or sinistral, shells, say the researchers, who have relocated to the Chubu University in Kasugai, Japan. The accomplishment — reported May 14 in Development — marks the first time researchers have been able to make heritable changes in snail genes, says evolutionary geneticist Angus Davison of the University of Nottingham in England. Teams led by Davison and Kuroda had previously published evidence independently that Lsdia1 is responsible for the twist, but the new paper provides the definitive proof, Davison says. In the new study, Kuroda and Abe also found that Lsdia1 causes the cells’ internal scaffolding — the cytoskeleton — to skew to the left or right very early on, when snail embryos are just single cells. Finding that early twist solves a long-running mystery: When does asymmetry start?
5-13-19 Bacteria could identify month-old suspicious stains at crime scenes
Stains at crime scenes can sometimes be hard to identify, but the unique combination of bacteria they contain may help. Large splatters of blood at a crime scene can be self-evident, but investigators sometimes need to work out if tiny stains are significant. “If you see something that looks like a trace, you want to know if it’s important,” says Natasha Arora, of the Zurich Institute of Forensic Medicine in Switzerland. Luminol spray can reveal blood spots, but it isn’t a definitive test, as it can cross-react with other substances, including faeces and household bleach. Now Arora and her colleagues have found that the microbes in small traces of body fluids can persist in a room for at least thirty days. This could lead to new ways to tell if crime scene stains are blood, faeces, or vaginal fluid, for instance, says Arora. Previous work has shown that different parts of the body have distinctive communities of bacteria, viruses and fungi. So Arora’s team swabbed different body fluids, to see if their microbial mix would still be distinguishable after being exposed to air for a month. “If you go to a crime scene and you find traces, they’re not generally completely fresh,” says Arora. The team took multiple samples of blood, menstrual blood, semen, vaginal fluid, saliva, and skin, and placed the swabs on a high shelf in a frequently used room in their lab. To identify the bacteria present, they analysed the genetical material of the swabs at the beginning and end of the month.
5-10-19 Scientology ship quarantined
A cruise ship belonging to the Church of Scientology is under quarantine in Curaçao this week after a crew member was diagnosed with measles. The Freewinds ship was turned back from St. Lucia when the outbreak was identified, and Curaçao officials this week began assessing the health of the more than 300 people on board. The ship is used as a floating religious retreat for top members of the church. Actress Leah Remini, a former Scientologist, tweeted that the outbreak is embarrassing for the sect because the ship “is where they reach one of the highest levels of Scientology & are supposed to be impervious to ‘Wog Illness.’” “Wog” is what church members call a non-Scientologist.
5-10-19 Doctors’ dirty coats
Most patients prefer their doctor to wear a traditional white coat, a garment seen as a reassuring symbol of medical know-how. But new research has found that health-care workers’ attire is often contaminated with dangerous bacteria and other pathogens, reports The New York Times. A review of previous studies found that up to 16 percent of doctors’ coats tested positive for MRSA, and up to 42 percent for Gram-negative rods—types of antibiotic-resistant bacteria that can cause skin and blood infections, sepsis, pneumonia, and other health issues. And it isn’t only coats that pose a risk. The researchers found that stethoscopes, phones, and digital tablets can also be contaminated with dangerous bacteria. A previous study of orthopedic surgeons found a 45 percent match between the species of bacteria on their ties and those in their patients’ wounds. Better hygiene could reduce the germ loads. Studies have found that most American physicians wash their coats less than once a week; up to 17 percent go more than a month.
5-10-19 A poisonous trend among kids
Record numbers of young people in the U.S. are trying to kill themselves with poison, new research has found. Suicide attempts of this kind have more than doubled among people under 19 in the past decade, and tripled among girls and women ages 10 to 24. While the suicide rate across all age groups and genders in the U.S. is increasing, the sharp rise in poison-related suicide attempts by young people has left researchers baffled. “There’s something very alarming happening here,” co-author Henry Spiller, from the Central Ohio Poison Center, tells The Washington Post. After analyzing 19 years of nationwide data, the researchers found that suicide-by-poison attempts remained essentially flat among children ages 10 to 15 until 2010, and then skyrocketed from 2011 to 2018—increasing 141 percent overall. The substances used were typically household drugs such as Tylenol, antihistamines, and ADHD medication. Spiller says there is no obvious explanation for the sudden increase, but suspects the spread of smartphones among youngsters—and the access it gives them to information on suicide—may be a factor.
5-10-19 New type of dementia discovered
Scientists have identified a new form of dementia that has long been misdiagnosed as Alzheimer’s—a confusion that may have hampered efforts to find treatments for that disease. The researchers say that, based on autopsy studies, about 20 to 50 percent of people ages 80 and over have brain changes associated with the newfound neurodegenerative condition, called LATE. Scientists believe that about 20 percent of older people diagnosed with Alzheimer’s would be better classified as having LATE, reports The Times (U.K.), and that another 30 percent may have both diseases. While Alzheimer’s and LATE have similar symptoms—including memory loss and cognitive decline—the conditions are caused by different misbehaving brain proteins, and LATE progresses much more slowly. That “might help explain why so many past Alzheimer’s drugs have failed in clinical trials,” says lead author Peter Nelson from the University of Kentucky. Scientists have long wondered about the existence of another Alzheimer’s-like disease, after discovering through autopsies that many people who die in advanced age have dementia symptoms but don’t have two hallmarks of Alzheimer’s—the protein amyloid beta, which forms plaques between nerve cells in the brain, and tau, which grows tangles inside brain cells. There are currently no tests to identify LATE. Still, the discovery of the disease could help refine research aimed at early identification and treatment of neurodegenerative conditions.
5-10-19 Turning brain waves into speech
In a potentially major breakthrough for people who have lost their ability to speak through conditions such as Parkinson’s, scientists have developed a device that can instantaneously decode brain activity into synthetic speech. Most speech synthesizers require the user to spell out words letter by letter using eye or facial movements, a drawn-out and exhausting process. For this new technique, scientists at the University of California, San Francisco monitored electrodes implanted in the brains of five people being treated for epilepsy who were capable of speaking. They had the volunteers read out hundreds of sentences, so that the electrodes could identify which electrical signals the brain sent out to move the person’s lips, tongue, voice box, and jaw. They then translated these movements into speech sounds, creating a “virtual vocal tract” that could be controlled directly by the brain. Up to 69 percent of the words spoken by the computer were correctly identified by people who transcribed the virtual voice, reports CNBC.com. Senior author Edward Chang says that with further refinement “we should be able to build a device that is clinically viable in patients with speech loss.”
5-10-19 Every country worldwide is now using the most effective polio vaccine
Mongolia and Zimbabwe have added the inactivated polio vaccine to their routine immunisation programmes. They were the last two countries in the world not to use this form of the vaccine. Polio is a contagious viral infection that mainly affects young children and can lead to paralysis or death. It has been largely contained throughout Europe, the Americas, Southeast Asia and the Western Pacific, and cases have fallen from 350,000 in 1988 to just 33 reported cases in 2018, according to the World Health Organisation. That decrease has predominantly been due to the oral polio vaccine, which contains a weakened form of the virus that triggers the immune system to create antibodies to fight off the disease. This form of the vaccine is effective but in rare cases it can mutate and cause vaccine-derived poliovirus. The inactivated polio vaccine (IPV) creates antibodies that can better enter the central nervous system and provide more protection, but must be administered through injection by a trained health worker. Three countries have large outbreaks of wild poliovirus – Afghanistan, Pakistan and Nigeria – though Nigeria hasn’t reported any cases due to wild poliovirus in 2019 yet. Afghanistan has had 7 cases of wild poliovirus this year and Pakistan has had 11. In both countries, resistance to the vaccine is fierce and has resulted in outbreaks of violence and attacks that have led to the deaths of health workers administering it. Pakistan’s health minister Zafar Mirza said in a statement that pockets of under-immunised children are allowing the virus to survive, but it could be possible to end transmission of the disease by the end of the year.
5-9-19 A quarter of people who meditate experience negative mental states
A quarter of regular meditators say they have experienced negative mental states as a result of meditation, including anxiety and fear. Marco Schlosser at University College London and colleagues surveyed 1232 people who had meditated at least once a week for at least two months. The volunteers were asked if they had ever felt any “particularly unpleasant experiences”, including anxiety, fear or disturbed emotions, that they attributed to their meditation practice. Just over 25 per cent reported that they had. They were not asked about the severity of their experiences or whether they occurred specifically during a meditation session. People who had previously attended a meditation retreat and those who had higher levels of repetitive negative thinking were more likely to report unpleasant meditation-associated experiences, while women and religious respondents were less likely. The participants were also asked about the types of meditation they practised. The survey found that those who only engaged in deconstructive types of meditation, such as Vipassana and Zen Buddhist meditation, were more likely to report negative mental states than those who only practised other types, such as mindfulness. Deconstructive meditation involves contemplating the nature of conscious experience and emotional patterns. The team did not study the triggers for these unpleasant experiences, but Schlosser says a possible explanation may be that deconstructive meditation practices encourage meditators to reflect on the impermanent nature of thoughts and feelings. “If one notices this impermanence, one might have a sense of or get a fear of annihilation,” says Schlosser.
5-9-19 Some deep-sea fish have evolved souped-up colour night vision
Fish living in the deep ocean have evolved highly-sensitive eyes that can see a range of colour hues in the near-darkness. “It’s a big surprise,” says Zuzana Musilova at the University of Basel in Switzerland. “They have more sensitive eyes and can see way better than humans in lower light.” Musilova and her colleagues collected DNA from 26 species of fish that live more than 200 metres below sea-level. Analysing this DNA, the team found that six species carried additional genes for rod opsin – the light-sensitive protein that enables the retina’s rod cells to detect light. Vertebrate animals use rod opsin to detect light in dim environments, but most species – including humans – only have one rod opsin gene. However, adult silver spiny fins (Diretmus argenteus) – a flat fish that lives at depths down to 2,000 meters— has 38 of them. The team translated these genes into proteins in a dish and shone lights of different wavelengths onto them, to see how they’d respond. They found that that these opsins detect a wide range of colours, and are especially sensitive to green and blue light. “We believe they can detect more shades of blue and green than us,” Musilova says. Musilova says having highly sensitive eyes may be useful for detecting the glowing bioluminescence emitted by many deep-sea creatures. These bioluminescent lights are mostly blue and green in colour. Being able to tell colours apart could help fish distinguish whether a flash comes a predator or prey, Musilova says.
5-9-19 Ancient South American populations dipped due to an erratic climate
Hunter-gatherers declined when weather patterns became unpredictable 8,600 years ago. Ancient South American populations declined sharply as rainfall became increasingly unpredictable starting around 8,600 years ago, researchers say. But hunter-gatherer groups from the Andes and the Amazon to the continent’s southern tip bounced back quickly once rain returned to a relatively stable pattern about 6,000 years ago, report archaeologists Philip Riris and Manuel Arroyo-Kalin, both of University College London. During that roughly 2,600-year intervening period, bouts of unusually wet or dry conditions that disrupted local food sources occurred frequently, every five years or so on average, the scientists report online May 9 in Scientific Reports. Foragers would have been unable to predict whether extreme rainfall or drought was next up, or precisely when those conditions would hit. Previously, average rainfall patterns had included an abnormally wet or dry year only every 16 to 20 years, Riris and Arroyo-Kalin estimate from rainfall records gleaned from ancient sediments and other sources. To estimate population changes from around 12,000 to 2,000 years ago, the researchers analyzed 5,450 radiocarbon dates from nearly 1,400 South American archaeological sites. Statistical estimates of when substantial population ups and downs took place, based on changes over time in numbers of archaeological sites, could not assess absolute numbers of people living in South America at various times. Climate records compared to ancient population patterns were divided into 100-year stretches. The greatest rainfall fluctuations and largest human population declines were seen in northern, tropical parts of South America.
5-9-19 I gave away half my liver in exchange for a new kidney for my mother
“It was heart-breaking for me to see what my mom was going through – dialysis was getting to be really painful for her,” says Aliana Deveza, in Santa Cruz, California. “I had to help.” Deveza’s mother was on the waiting list for a kidney transplant. Like some others in this situation, Deveza wanted to donate one of her own kidneys – but she was turned down because she might develop the same health problems as her mother in later life. So Deveza came up with a different plan. In 2017 she instigated the world’s first paired exchange of different organs between living donors, swapping half her liver for someone else’s kidney. A case study of the organ swap has now been published, and the surgeons who were involved are calling for more exchanges like this. “You can imagine the enormous impact for mixed organ extended chains,” says John Roberts, a surgeon at University of California, San Francisco. Most organ transplants come from people who have died, but there are never enough organs for those who need them. As most people can get by with just one of their kidneys, people with kidney failure are increasingly receiving donated organs from relatives or friends. If someone wants to donate but their immune system is incompatible, doctors may be able to find pairs of would-be donors who can each give a kidney to the other’s relative. Sometimes there can be long chains of such transfers, usually started by someone happy to donate their kidney to a stranger. When Deveza was looking into such chains, she came across research describing the idea of trading a kidney with the only other organ generally taken from a living donor – the liver. People can donate up to 60 per cent of this organ. The liver is one of the few organs that can regenerate, so the donor eventually regrows a full-sized liver, as does the recipient.
5-9-19 A gut bacteria transplant may not help you lose weight
Getting intestinal microbes from a lean person didn’t help obese people drop pounds. Changing your gut microbes may not help you lose belly fat. In a preliminary study, obese people got either capsules containing gut microbes from a lean person or placebo pills. Microbes from the lean donor took hold in the guts of the obese recipients. But early results suggest that the bacteria didn’t change the volunteers’ weight or levels of a hormone that helps signal fullness, gastroenterologist Jessica Allegretti reported May 8 at a news conference. People with obesity often have different types of gut microbes than lean people do. And previous studies with lab animals and anecdotal evidence from people have suggested that transfers of intestinal bacteria and other microbes — collectively known as the gut microbiome — from a donor to a recipient may lead to weight loss or gain, depending on whether the donor was lean or obese. So the researchers reasoned that giving obese people gut microbes from a lean person, known as a fecal or intestinal microbiome transplant, might help overweight people control appetite and shed pounds. In the study, 11 obese people swallowed 30 capsules containing gut microbes from the same lean donor. Another 11 obese people got identical-looking capsules that contained no gut bacteria. At four weeks and again at eight weeks after the initial dose, the volunteers downed 12 additional capsules. Twelve weeks after the experiment’s start, the researchers measured changes in the people’s gut microbe mix, their weight, levels of a protein called GLP-1 and bile acid production.
5-9-19 50 years ago, scientists tried to transplant part of a human eye
Excerpt from the May 10, 1969, issue of Science News. After an attempted cornea transplant failed, ophthalmologists in Houston, Tex., tried a more daring experiment to restore the vision of 54-year-old John Madden…. They transplanted an entire eye from a donor who had died of a brain tumor.… [Later, the doctor who did the surgery] announced that only the front part of the donor’s eye had been transplanted; the back portion of Madden’s eye, including the optic nerve and part of the retina, had been preserved. — Science News, May 10, 1969. That partial eye transplant didn’t work, but researchers have made strides in restoring sight to people with some eye diseases, including an inherited form of blindness called Leber congenital amaurosis (SN: 5/30/15, p. 22). Nearly 185,000 corneas — the clear outer layer of tissue that covers the front of the eye — are transplanted worldwide each year, according to a 2016 survey in JAMA Ophthalmology. Yet, no one has successfully transplanted a whole human eye. Attempts in animals have had mixed success. In 2015, reconstructive surgeon Kia Washington of the University of Pittsburgh and colleagues transplanted part of a face, including an eye, from one rat to another. The eye survived. Then in 2018, Washington, now at the University of Colorado School of Medicine in Denver, and colleagues confirmed that, in two of four rats with transplanted eyes, blood flowed normally to the retinas. The rats could not see from the transplanted eyes because surgeons had cut the rodents’ optic nerves, which carry information from the eye to the brain. Eye transplants may help wounded soldiers and other people who need facial reconstruction or transplants. More work is needed on how to regrow optical nerves to restore vision.
5-8-19 Kentucky teen who sued over vaccine gets chickenpox
A US teenager who took legal action against his school after he was banned for refusing the chickenpox vaccination now has the virus, his lawyer says. Jerome Kunkel, 18, made headlines last month after he unsuccessfully sued his Kentucky school for barring unimmunised students amid an outbreak. His lawyer, Christopher Weist, told US media that the teen's symptoms developed last week. The student had opposed the vaccine on religious grounds. His lawsuit argued the vaccine is "immoral, illegal and sinful" and that his rights had been violated. The ban from his school, Our Lady of the Sacred Heart/Assumption Academy in Walton, came during an outbreak that sickened at least 32 pupils. Mr Weist told NBC News his young client did not regret his decision to remain unvaccinated. "These are deeply held religious beliefs, they're sincerely held beliefs," Mr Wiest said. "From their perspective, they always recognised they were running the risk of getting it, and they were OK with it." The Northern Kentucky Health Department excluded unvaccinated students from classes and extracurricular activities from 14 March. A Kentucky judge sided with the health department in April, saying the 18-year-old did not have a right to play sports. The teenager's father, Bill Kunkel, said the vaccines were derived from aborted foetuses, which went against his family's religious beliefs. Some viruses used to make vaccines are grown with cells descended from matter that was sourced from two human foetuses electively aborted in the 1960s. But no new human cells have been used since then to produce vaccines, according to health authorities and drug manufacturers. (Webmaster's comment: The height of human stupidity knows no bounds!)
5-8-19 Are heat-not-burn tobacco products a safer alternative to cigarettes?
The rise of vaping has seen tobacco firms revisit an old cigarette alternative, but the health benefits are far from clear. FIRST there were smokers. Then there were vapers. Now there is a tribe of nicotine users so new that they don’t have a name yet. Maybe we’ll call them heaters or smoulders. But if the tobacco industry gets its way, they will become a familiar sight. The new tribe are converts to what are called heated tobacco products (HTPs) or heat-not-burn (HNB) devices. Instead of incinerating tobacco they warm it up, releasing an aerosol of nicotine and other compounds that the user inhales. They have been described as a hybrid of a cigarette and a vape (see “New hotness”). These devices have been on sale for years, but tobacco firms have begun a major PR offensive in the belief that the time is right to win over more consumers. “They’re very busy all over the world. It’s a massive campaign,” says Anna Gilmore of the Tobacco Control Research Group at the University of Bath, UK. Take Philip Morris International (PMI), which makes the leading product on the global market, IQOS (I Quit Ordinary Smoking). Last week, the US Food and Drug Administration (FDA) approved it for sale. PMI says the device, which is already available in 41 other countries and territories, is used by 10.4 million people, the vast majority of them ex-smokers. The company also recently launched a campaign encouraging people to switch from cigarettes. If efforts like these succeed, we can expect a rerun of the health debates that have raged over the e-cigarettes used by vapers. Are HTPs safer than smoking? Do they encourage people to quit, or to start? What are the long-term risks? The answers matter because the tobacco industry is aiming HTPs at smokers, who might otherwise quit or shift to vaping.
5-8-19 Zombieland: The vast world of hidden microbes miles beneath your feet
No matter how deep we dig, life has always found a way to survive. The remarkable story of these impossible microbes can teach us about how life evolved. “THE first ten million years were the worst,” said Marvin, “and the second ten million years, they were the worst too. The third ten million years I didn’t enjoy at all. After that I went into a bit of a decline.” Poor old Marvin the Paranoid Android, left to wait for eternity in a car park at the Restaurant at the End of the Universe. But if the ordeal of this Douglas Adams character seems trying, consider the real-life fate of microorganisms discovered buried in sediment under the South Pacific in 2010. They had been there for around 100 million years. And they were still alive – barely. Their metabolisms had slowed to a crawl and they were using what little energy they had just to stay in the game. But alive they were. “They’re definitely breathing!” says Steven D’Hondt at the University of Rhode Island, who discovered them. The presence of ancient, zombie microbes entombed deep under Earth’s surface may seem surprising, but D’Hondt and his crew would have been more surprised not to find them. Wherever we drill into the planet, we find life. And while some is zombie-like, most is not. Life underground is rich, dynamic and deeply strange. What it teaches us has important implications for our concept of life itself, not just here on Earth, but on other planets too. For centuries, nobody thought that Earth’s crust was anything other than inanimate rock. The first hint to the contrary came in 1926, when US geologists extracted water from oil wells nearly 600 metres down and discovered bacteria swimming inside. If true, this would have been a remarkable discovery. Instead, it was widely dismissed as contamination.
5-8-19 Birds introduced to Hawaii have evolved rapidly in just decades
Non-native birds are replacing Hawaii’s endemic species, adapting to new environments at a blistering pace of evolution. In the Hawaiian Islands, most native fruit-eating birds have gone extinct and been replaced by introduced counterparts. On the island of O’ahu, seed dispersal through fruit consumption is now mostly carried out by non-native species. Jason Gleditsch, of the University of Illinois at Urbana-Champaign, and his colleagues have been studying how these changes have affected the island. They have found that, despite the loss of native fruit-eaters, O’ahu still has complex, functioning ecosystems – possibly thanks to rapid evolution of non-native birds to fill the niches vacated by the lost endemic species. To see whether the introduced birds have been evolving on O’ahu, Gleditsch and his colleague Jinelle Sperry compared four non-native songbird species on the island with museum specimens collected from their native range relatives. They measured the birds’ bills, tails, legs and wings – body parts that are all used for foraging.They discovered that, since living on the island, these birds have undergone substantial physical changes of up to 13 per cent in some measurements over a remarkably brief period. Compared to native range specimens, two species had significantly shorter legs, and most species had larger, thicker bills, shorter wings, and longer tails. The four species studied were introduced to O’ahu only 50 to 90 years ago. “Evolution is typically thought to occur over millennia,” says Gleditsch. “We’re talking about ten to twenty generations at most.” But statistical analysis suggests that the birds’ evolution is likely only partially shaped by adapting to life on the island. There’s evidence that “founder effects” may also have been at work – an evolutionary phenomenon in which the genetic mix of a small starting population can prompt a species to evolve changes that aren’t necessarily useful or adaptive. (Webmaster's comment: When an animal makes new children every year, and last years children are making more new children, evolution can be very rapid.)
5-8-19 Thousands of people in Finland to receive genetic health predictions
Thousands of people in Finland will soon find out their genetic risk of developing common conditions such as type 2 diabetes, in a national bid to encourage healthy lifestyle changes. Many countries are beginning to dabble with using genetic data to predict citizens’ chances of developing common diseases, but Finland is an international leader, forging ahead with one of the largest ever trials of this kind. This has involved sequencing the genomes of around 3,400 volunteers and analysing these in search of hundreds of gene variants that are linked to greater-than-average risk of developing a common disorder. In particular, the trial is identifying people at genetic risk of heart disease, type 2 diabetes, and venous thromboembolism – blood clots that start in a vein. “We selected these three diseases because they are both preventable and actionable,” says Heidi Marjonen of the National Institute for Health and Welfare in Helsinki. The trial combines each person’s genetic data with information about their general health to predict those at risk. The results are due to be issued soon, in the form of “polygenic risk scores” – percentages that indicate a person’s individual risk compared to the population average. Polygenic risk scores have been under the spotlight in the UK recently, after health minister Matt Hancock announced that genetic tests had revealed he had a fractionally higher risk of prostate cancer than most men. The Finnish volunteers will receive their results via a secure web portal. Their reports will include a section that individuals can print out and share with their doctor, if they have concerns over the findings. Marjonen and her team hope the risk scores will help improve prevention, diagnosis and treatment. The risk of developing type 2 diabetes, for example, can be reduced by adopting a healthier diet and being more active.
5-8-19 Scientists dunked test tubes in hot springs to recreate life’s origins
Nearly 4 billion years after the life first arose on Earth, researchers have been trying to recreate the first steps towards life in steamy, bubbling pools in New Zealand. One of the big questions in understanding the origins of life is how smaller molecules like nucleotides, fatty acids, or amino acids first formed long, polymer chains like RNA, lipids, and proteins. Life as we know it uses RNA and DNA as its genetic material, while proteins look after and catalyse these and other processes, all encapsulated within the lipid membranes that surround each living cell. Previous lab experiments by David Deamer of the University of California, Santa Cruz, and his colleagues have demonstrated that basic, cell-like structures – called protocells – can form in hot-spring like conditions, with temperatures of 80 to 90 centigrade and repeated cycles of drying and dehydration. These conditions can bring simple molecules together and encourage them to form the long polymer chains essential for life. If lipid molecules are present too, this simulated environment can cause these polymers to become encapsulated inside fatty membranes that are similar to those seen on the outside of all cells today. But it wasn’t known if these laboratory findings could really happen in real-world conditions. To find out, Deamer’s colleague Bruce Damer travelled to Hell’s Gate near the town of Rotorua in New Zealand. This active geothermal area with acidic hot springs is “like a chemistry experiment that nature is carrying out,” says Damer. He placed glass vials containing a “prebiotic soup” into a near-boiling pool. This soup contained fatty acids and glyceride, another component of lipids. The mix also included two components of the building blocks of RNA, which is widely believed to have been life’s original genetic material, before DNA was adopted.
5-7-19 A tiny mystery dinosaur from New Mexico is officially T. rex’s cousin
It took decades to ID the 92-million-year-old tyrannosaur, newly named Suskityrannus hazelae. More than 20 years ago, paleontologists unearthed two partial skeletons of a mysterious dinosaur species in New Mexico. This creature, which lived about 92 million years ago, bore some resemblance to giant tyrannosaurs that reigned from about 80 million to 66 million years ago. One was even found with what could have been a partly digested lizard skull. But the dino was so tiny — only about a meter tall at the hip — it left scientists to wonder where it fit in. “There was enough of a skeleton to be super intriguing, but not enough to nail it down,” says Sterling Nesbitt, a paleontologist at Virginia Tech in Blacksburg who dug up one of the fossils. At the time, paleontologists didn’t have many other carnivores in the dinosaur’s size range to provide a point of comparison, Nesbitt says. Now, remnants of tyrannosaurs from Asia and North America have fleshed out the Tyrannosaurus rex’s family tree and allowed researchers to pin the new dinosaur as one of its kin. Analyses of the newly identified dinosaur, named Suskityrannus hazelae, reveal that this small tyrannosaur boasted some of the signature skeletal features of its megapredator relatives, researchers report online May 6 in Nature Ecology and Evolution. This discovery helps illuminate how tiny hunters that emerged over 100 million years ago gave rise to such enormous, bone-crunching tyrannosaurs like T. rex (SN: 3/16/19, p. 11).
5-7-19 British bluebells 'have advantage over Spanish bluebells'
Fears that the British bluebell could go extinct are unfounded, say scientists. The introduced Spanish variety has lower fertility and is unlikely to wipe out the native plant, according to genetic tests. The Spanish bluebell's escape into the wild has raised concerns that the two plants could mix, leading to the loss of one of the spectacles of spring. The violet-blue flowers appear in April and May, carpeting the woodland floor. It turns out that the British bluebell has a genetic advantage. "The greater fertility of the native British bluebell coupled with the huge numbers of individuals that exist in the wild means that it's got considerable resilience against any threat from these introduced plants," said Prof Pete Hollingsworth, director of science at the Royal Botanic Garden Edinburgh (RBGE). The British bluebell is one of the nation's best-loved plants, with 50% of the world's population found in the UK. The native bluebell, Hyacinthoides non-scripta, also goes by the name common bluebell, wood bell, fairy flower and wild hyacinth. Millions of bulbs can be found in just one ancient woodland, giving rise to carpets of flowers in April and May. The Spanish bluebell, Hyacinthoides hispanica, was introduced into the UK by the Victorians as a garden plant and can be found today alongside the native bluebell in woodlands as well as on road verges and in gardens.
5-7-19 Small tyrannosaur 'was cousin of T. rex'
Scientists have described a diminutive new tyrannosaur from New Mexico, US. Called Suskityrannus hazelae, the dino would have stood about 1m tall at the hip and was perhaps no more than 3m in length - not much longer than just the skull of fearsome T. rex. "Suski" lived earlier in time, however - 92 million years ago, compared with 80–66 million years ago for the biggest members of the tyrannosaur dynasty. It should, though, provide some fresh evolutionary insights, researchers say. "The discovery of Suskityrannus is a rare instance where we find a key new species from a poorly known period of Earth history, and the discovery shows what tyrannosaurs were like before they became the formidable predators like Tyrannosaurus rex that have captured the imaginations of so many people," said Alan Turner from Stony Brook University. The description of Suski appears in the journal Nature Ecology and Evolution. Virginia Tech's Sterling Nesbitt, the lead author on the paper, found a number of the key bones as a 16-year-old high school student in 1998, while participating on a dig expedition in New Mexico's Zuni Basin. Understanding those bones has been a major part of his palaeontology career ever since. "Suskityrannus gives us a glimpse into the evolution of tyrannosaurs just before they take over the planet," he said. Co-author Steven Brusatte from the University of Edinburgh, UK, added: "Suskityrannus is a key link between the enormous bone-crunching dinosaurs like T. rex and the smaller species they evolved from. "The new species shows that tyrannosaurs developed many of their signature features like a muscular skull, broad mouth, and a shock-absorbing foot when they were still small, maybe as adaptations for living in the shadows."
5-6-19 Astronauts may have vision problems because of liquid in their brains
Going to space changes your brain. Astronauts who have spent months in microgravity have more liquid in their brains, which may affect their vision even after they get back home. On Earth, gravity pulls all your bodily fluids down towards your feet. In space, that’s not the case. “As soon as you enter microgravity, bodily fluids flow to the upper part of the body,” says Angelique Van Ombergen at the University of Antwerp in Belgium. “That’s why when you see pictures of astronauts on the space station they look like they have a puffy head.” Van Ombergen and her colleagues scanned the brains of 11 Russian cosmonauts before and after going to space to determine the effects of microgravity on the brain’s ventricles – chambers that hold cerebrospinal fluid. They found that when the cosmonauts returned home, the volume of their ventricles had increased by an average of more than 11 per cent to accommodate the extra fluid flowing into their heads in microgravity. Even about seven months later, the ventricles were more than 6 per cent bigger than before the cosmonauts launched. It is not yet clear what effects this might have on brain function. The team found a correlation between the volume of one of the four ventricles and loss of visual acuity, but it was not strong enough to be certain the inflated ventricle was actually causing the changes in vision that are a common complaint for astronauts.
5-6-19 Traces of five drugs found on 1000-year-old South American ritual kit
A 1000-year-old collection of drug paraphernalia found in a rock shelter in Bolivia features traces of five psychoactive chemicals, including cocaine and components of ayahuasca. This is the largest number of psychoactive compounds detected in a single archaeological find in South America, the researchers say. The plants they come from aren’t native to the highland area where they were found, so they may have been brought there by trading networks or travelling shamans. The artefacts were found among the rubble inside a structure that may have served as a funerary enclosure in the Lípez highlands of south-western Bolivia. They include a 28-centimetre-long leather bag, a pair of wooden snuffing tablets, a snuffing tube, a pair of llama-bone spatulas, a textile headband, fragments of dried plant stems and a pouch made from three fox snouts stitched together. The snuffing tube and tablets feature ornate carvings of human-like figures. Radiocarbon dating puts the date of the bag at AD 905 to 1170, roughly coinciding with the collapse of the Tiwanaku state, a once-powerful Andean civilisation that endured for around five centuries. Drugs are thought to have played an important role in Tiwanaku culture, possibly in healing ceremonies and religious rituals believed to enable contact with the dead. Melanie Miller at the University of Otago, New Zealand, and her colleagues used mass spectrometry to analyse samples from the pouch and plant stems. They detected five psychoactive compounds: cocaine, benzoylecgonine (BZE), bufotenine, harmine and dimethyltryptamine (DMT).
5-6-19 An ancient pouch reveals the hallucinogen stash of an Andes shaman
The find had traces of mind-altering chemicals, including some used to make ayahuasaca. A leather bag stuffed with ritual items, found high in the Andes Mountains, has yielded rare clues to South American shamans’ hallucinatory visions around 1,000 years ago. One artifact in the radiocarbon-dated bag, a pouch stitched out of three fox snouts, contains chemical traces of five mind-altering substances obtained from at least three plants, say bioarchaeologist Melanie Miller of the University of Otago in Dunedin, New Zealand and her colleagues. Chemical residues include two primary ingredients of ayahuasca, a vision-inducing concoction still used by ritual specialists in native South American communities, the scientists report online the week of May 6 in the Proceedings of the National Academy of Sciences. Cocaine residue suggests that the fox pouch also held coca leaves. The researchers found the ancient ritual bundle in a Bolivian rock-shelter called Cueva del Chileno. Along with the fox pouch, the leather bag contained two carved wooden tablets used for snorting, or snuffing, powdered substances, a carved snuffing tube, a pair of llama-bone spatulas, a woven band thought to be a headband and two dried plant fragments tied to wool and fiber strings. Objects in the bag show influences of an ancient Andean society called Tiwanaku (SN Online: 8/24/15), the researchers say. As in many ancient Andean and Amazonian cultures, Tiwanaku shamans entered altered mental and physical states to communicate with revered ancestors and supernatural beings.
5-6-19 We've found the medium-sized tyrannosaurs that came before T. rex
We now have a better idea of what T. rex’s ancestors may have been like. Two fossils have been found of a new tyrannosaur species, dubbed Suskityrannus hazelae, that lived around 90 million years ago, before the tyrannosaurs evolved into giants like T. rex. The fossils show that tyrannosaurs developed many of their characteristic features such as a muscular skull, broad mouth and a shock-absorbing foot when they were still small. “Suskityrannus gives us a glimpse into the evolution of tyrannosaurs just before they take over the planet,” says palaeontologist Sterling Nesbitt at Virginia Tech. T. rex, one of the biggest predators ever to walk the earth, is probably the most famous of all dinosaurs. What many people don’t realise, says Nesbitt, is that the reign of the giant tyrannosaurs like T. rex was surprisingly short – they only evolved around 15 million years before the dinosaurs were wiped out. Palaeontologists have found very early, small tyrannosaurs that lived up to 150 million years before the giants appeared. But what happened right before the giants evolved has been a bit of a mystery, because of a gap in the fossil record. S. hazelae fills in this gap. The first, very incomplete skeleton was found in New Mexico in 1997. A second, more complete fossil was found by Nesbitt in 1998 while he was still at high school. Nesbitt and colleagues have now finally published a paper describing the find. The team estimates that this second individual was 1 metre high at the hip, 3 metres long and weighed 20 to 40 kilograms when alive. The bones show it was still a juvenile when it died, so the species may have grown a bit bigger but definitely not as large as a giant like T. rex.
5-5-19 How technology helps our memories
When I was a student, in the distant past when most computers were still huge mainframes, I had a friend whose Ph.D. advisor insisted that he carry out a long and difficult atomic theory calculation by hand. This led to page after page of pencil scratches, full of mistakes, so my friend finally gave in to his frustration. He snuck into the computer lab one night and wrote a short code to perform the calculation. Then he laboriously copied the output by hand, and gave it to his professor. Perfect, his advisor said — this shows you are a real physicist. The professor was never any the wiser about what had happened. While I've lost touch with my friend, I know many others who've gone on to forge successful careers in science without mastering the pencil-and-paper heroics of past generations. It's common to frame discussions of societal transitions by focusing on the new skills that become essential. But instead of looking at what we're learning, perhaps we should consider the opposite: What becomes safe to forget? In 2018, Science magazine asked dozens of young scientists what schools should be teaching the next generation. Many said that we should reduce the time spent on memorizing facts, and give more space for more creative pursuits. As the internet grows ever more powerful and comprehensive, why bother to remember and retain information? If students can access the world's knowledge on a smartphone, why should they be required to carry so much of it around in their heads? Civilizations evolve through strategic forgetting of what were once considered vital life skills. After the agrarian revolution of the Neolithic era, a farm worker could afford to let go of much woodland lore, skills for animal tracking, and other knowledge vital for hunting and gathering. In subsequent millennia, when societies industrialized, reading and writing became vital, while the knowledge of plowing and harvesting could fall by the wayside.
5-3-19 Toxins in e-cigarettes
Some of the most popular e-cigarette products used by millions of Americans every day may be contaminated with bacterial and fungal toxins that can cause lung disease. Researchers at Harvard looked at 75 e-cigarette cartridges and e-liquid products that were on sale in 2013 and found that 23 percent contained traces of endotoxin, a microbial agent found in bacteria, and 81 percent had traces of glucan, a toxic substance common in fungi. Both toxins have been linked to health issues such as asthma, inflammation, and reduced lung function. Overall, cartridges contained 3.2 times higher concentrations of glucan than the liquid products. The source of the contamination isn’t clear, but the researchers speculate that the cotton wicks in single-use cartridges may be responsible, because endotoxin and glucan are known contaminants of cotton fibers. “[These findings] add to the growing concerns that we have about the safety of e-cigarettes,” lead author David Christiani tells NBCNews.com. “People should not assume that e-cigarettes are safe.”
5-3-19 DR Congo Ebola deaths pass 1,000
. The death toll from the Ebola epidemic in the Democratic Republic of Congo has passed 1,000, the health ministry says. DRC's Ebola outbreak began in August and is the second deadliest in history. World Health Organization deputy director Dr Michael Ryan said mistrust and violence was harming efforts to tackle the disease as it spread through the east of the country. There have been 119 documented attacks on medical centres and staff since January, Dr Ryan said. WHO staff anticipated "continued intense transmission", he added, in a briefing to reporters in Geneva. Health workers have plenty of vaccines - more than 100,000 people have already been given the treatment. But continuing violence in the east of the country where militias are present, as well as mistrust of doctors, was hindering their programme, Dr Ryan said. "We still face major issues of community acceptance and trust," he said. The DRC is also suffering from an outbreak of measles which has killed more than 1,000 people, with 50,000 cases reported. WHO staff have confirmed measles in 14 of the country's 26 provinces, in both rural and urban areas. Ebola is still contained within two provinces in the DRC but it is becoming harder to monitor the spread of the virus because of violence. The WHO said the risk of a global spread is low, but it was very likely cases would spread into neighbouring countries. Most Ebola outbreaks are over quickly and affect small numbers of people. Only once before has an outbreak been still growing more than eight months after it began - that was the epidemic in West Africa between 2013 and 2016, which killed 11,310 people.
5-3-19 Genetic variants may put some athletes at higher risk of sudden death
A cluster of unexplained deaths of US athletes while exercising could be down to several genes that affect the ability of red blood cells to carry oxygen. The findings could be turned into a test to see if some people are at greater risk of collapsing on the sports field, says Lorena Madrigal at the University of South Florida. The sudden death of young athletes is very rare, and is sometimes caused by a unsuspected heart problem, but being a carrier of the gene variant that causes sickle cell anaemia may also be a factor. Sickle cell anaemia is a genetic disorder that involves having abnormal haemoglobin, the molecule that carries oxygen in red blood cells. Under some conditions, such as physical exertion, these red blood cells can warp into a crescent shape and block blood vessels, causing pain and breathing difficulties. The disorder is more common in people who have African, Mediterranean and South Asian ancestry, probably because it gives protection from malaria. It was thought that health problems only occur when a person has two copies of sickle cell gene variants, and that carriers – who have only one copy– had no issues. But some suspect that sickle cell carriers have a higher risk of sudden death during exercise. There have been 23 known cases of this happening to African-American athletes who were carriers, according to a registry of such cases going back 31 years, although we don’t know if this gene was responsible. Madrigal has been researching whether particular sickle cell carriers may be more susceptible to sudden collapse during exercise. She and her colleagues genetically tested 29 African-American college football players who are sickle cell carriers, and asked them about their health.
5-2-19 An AI used art to control monkeys’ brain cells
Such tailored regulation of neural activity could lead to new types of neuroscience experiments. New artwork created by artificial intelligence does weird things to the primate brain. When shown to macaques, AI-generated images purposefully caused nerve cells in the monkeys’ brains to fire more than pictures of real-world objects. The AI could also design patterns that activated specific neurons while suppressing others, researchers report in the May 3 Science. This unprecedented control over neural activity using images may lead to new kinds of neuroscience experiments or treatments for mental disorders. The AI’s ability to play the primate brain like a fiddle also offers insight into how closely AIs can emulate brain function. The AI responsible for the new mind-bending images is an artificial neural network — a computer model composed of virtual neurons — modeled after the ventral stream. This is a neural pathway in the brain involved in vision (SN Online: 8/12/09). The AI learned to “see” by studying a library of about 1.3 million labeled images. Researchers then instructed the AI to design pictures that would affect specific ventral stream neurons in the brain. Viewing any image triggers some kind of neural activity in a brain. But neuroscientist Kohitij Kar of MIT and colleagues wanted to see whether the AI’s deliberately designed images could induce specific neural responses of the team’s choosing. The researchers showed these images to three macaques fitted with neuron-monitoring microelectrodes. In one experiment, the AI aimed to create patterns that would activate neurons at a specific site in the ventral stream as much as possible, regardless of how it affected other neurons. In 40 of the 59 neural sites tested, AI-made pictures caused neurons to fire more than any image of a real-world object, such as a bear, a car or a face. The AI’s images generally caused neurons to fire 39 percent more than their maximum response to real-world images. Even when the monkeys were shown patterns previously designed by researchers specifically to trigger ventral stream neurons, the AI designs made these neurons fire at higher rates. (Webmaster's comment: In an old Sfy-fi book "The War Against The Rull", the aliens use patterns of lines to control men's minds. Today we can elicit a specific verbal response from people by asking seemingly unrelated verbal questions. Animal and human minds seem to be able to be programmed by external stimuli which makes perfect sense given how the mind works.)
5-2-19 A dinosaur’s running gait may reveal insights into the history of bird flight
A robot and ostriches with fake wings model Caudipteryx’s flapping stride. An early winged dinosaur couldn’t fly, but it could run. Now, with assists from a robotic dino and young ostriches wearing artificial wings, a study suggests that the dinosaur’s running gait caused its wings to flap, in what may have been an evolutionary precursor to flight. Caudipteryx was a peacock-sized dinosaur with feathered and winglike forelimbs that lived about 125 million years ago. Running at speeds of about 2.5 to 5.8 meters per second sent vibrations through its body, causing its wings to flap vigorously, scientists report online May 2 in PLOS Computational Biology. If true, the results suggest that some dinosaurs had to run before they could fly — adding a new wrinkle to a long-standing debate over whether the earliest fliers were flappers or gliders. Some researchers have suggested that the delicate, thin shafts in the feathers of primitive birds such as Archaeopteryx, which lived about 150 million years ago, wouldn’t have stood up to rigorous flapping, and so those animals probably glided between trees (SN: 6/5/10, p. 12). Other researchers analyzing the wing length, light bodies and powerful hind limbs of early winged dinosaurs such as Microraptor, which lived about 120 million years ago, suggest that these early fliers could have launched themselves into the air rather than needing to gently glide (SN: 10/26/16, p. 9). And a recent study of the wings of Archaeopteryx found that, feathers aside, its arm bones were strong enough to withstand short bursts of active, flapping flight (SN: 4/14/18, p. 9).
5-2-19 Two molecules could give us finer control over CRISPR gene editing
Molecules that act like off switches for CRISPR may one day be used as a drug to make gene editing therapies safer. The power of CRISPR gene editing to easily change DNA could lead to new treatments for cancers, viral infections, and genetic conditions. But as well as making desirable changes, CRISPR can also make unwanted mutations in DNA, a possible health risk. “Precision control lies at the heart of powerful technologies,” says Amit Choudhary of Harvard University, who has been looking for compounds that can help us more finely control CRISPR. He and his colleagues say they have now identified two promising molecules with the potential to stop the CRISPR-Cas9 enzyme from working within minutes. To find these, they analysed thousands of molecules, looking for those that could interfere with the enzyme’s ability to bind to DNA – a key requirement for being able to identify and alter genes. The CRISPR system uses Cas9, an enzyme from bacteria, to bind to DNA and then make a cut in the DNA sequence. The most commonly used version of the CRISPR technique uses a Cas9 enzyme that is constantly switched on, which may raise the risk of it binding other DNA sequences and causing unwanted edits. But the two molecules identified by Choudhary and his colleagues interfere with the enzyme’s ability to recognise and bind to DNA. Choudhary says these should allow scientists to stop the gene-editing process within minutes, thereby reducing the risks of off-target mutations. Larger anti-CRISPR proteins have previously been developed, but Choudhary says smaller inhibitors are likely to act faster and without prompting an immune response. When the team tested these molecules in mammalian cell and human plasma, they found that they were non-toxic and didn’t appear to disrupt the activity of essential genes.
5-2-19 Ebola outbreak in the DRC hits record number of cases in a single day
The number of Ebola cases in the Democratic Republic of Congo is rising faster, reaching a high of 27 confirmed cases in one day, according to the country’s health ministry. That surpasses the last record, set a few weeks ago, of 20 cases in one day. The latest figures from the World Health Organisation (WHO) bring the total confirmed cases to 1400, including 891 deaths, most of which are among women and children. The uptick in cases may not be caused by the disease spreading more quickly, but could be a sign of doctors in the region being able to more accurately count cases in towns that were previously off-limits due to sectarian violence. “The increase in the number of new cases in the Democratic Republic of Congo remains deeply concerning,” WHO said in the report. “With often difficult to access settings, disruptions by incidents of sporadic violence by armed militias, and limited healthcare resources, this outbreak is taking place in one of the most challenging circumstances ever confronted by WHO.” The outbreak began in August 2018 and healthcare workers have faced difficulty containing it due to lack of health infrastructure, mistrust in health workers among affected communities, and violent attacks in the region. A total of 33 healthcare workers have also died, including WHO epidemiologist Richard Mouzoko, who was killed when armed militia members attacked a clinic in Butembo on 19 April. Conflict has been constant in the region for decades, with some 70 militia groups vying for control over mining in the area. As the outbreak has continued, health workers and clinics have been specifically targeted with violence. Two clinics were firebombed in late February, and Doctors Without Borders temporarily pulled their workers out of the area to keep them safe.
5-2-19 Huge mega-rafts carried dinosaur-era animals on round-the-world trips
Huge floating logs carried communities of animals on round-the-world trips during the dinosaur era. The mega-rafts gave marine animals a way to travel without passing through deadly low-oxygen zones. We have long known of preserved logs up to 14 metres long from the Jurassic period 200 to 145 million years ago. The logs are covered in crinoids, an animal related to starfish that has a central body with many long feathery arms. The logs also carry oysters. Initial studies in the 1960s suggested that these logs were floating rafts that the crinoids had colonised. However, many palaeontologists believed that the logs could not have stayed afloat and that the crinoids must have colonised the wood after it sank to the bottom of the oceans. Now, Aaron Hunter at the University of Cambridge and his colleagues have shown that the logs really could float, probably for years. Hunter had the idea after fishing for crinoids and realising how light they are. Even fully grown adults are “like feathers”, he says. Instead, the key question was how quickly the wood took on water, which would weigh it down and cause it to rot. Using mathematical models of the flow of water into wood, the team calculated that a log over 10 metres long would stay afloat for at least two years. If the bark was fairly water-resistant, and was colonised by oysters that provided an additional barrier, such a log could float for 20 years or more. In that time, the crinoids could easily be carried halfway around the planet. The team also found that the crinoids clustered towards one end and the bottom of the log. This could indicate that the log was moving through the water. “The crinoids would have chosen an area of least resistance at the back,” says Hunter.
5-1-19 The psychology of magic and how it plays with our minds
We need to think our brain doesn't lie to get us through the day, but as a new London exhibition called Smoke and Mirrors shows, magic relies on the fact that it does. ACCORDING to John Nevil Maskelyne, “a bad conjurer will make a good medium any day”. He meant that, as a stage magician in 19th-century London, he had to produce successful effects night after night, while rivals who claimed their illusions were powered by the spirit world could simply blame a bad set on “unhelpful spirits”, or even on the audience’s own scepticism. A gaffe-ridden performance in the UK by one set of spiritualists, the US Davenport Brothers, drove Maskelyne to invent his own act. With his friend, the cabinet maker George Alfred Cooke, he created an “anti-spiritualist” entertainment, at once replicating and debunking the spiritualist movement’s stock-in-trade effects. Matthew Tompkins teases out the historical implications of Maskelyne’s story in The Spectacle of Illusion: Magic, the paranormal and the complicity of the mind (Thames & Hudson). It is a lavishly illustrated history to accompany Smoke and Mirrors, a new and intriguing exhibition at the Wellcome Collection in London. Both book and exhibition bring the story up to date, for the curious truth is, spiritualism stubbornly refused to die. Historical accident was partly responsible. In 1895, Guglielmo Marconi sent long-wave radio signals over a distance of a couple of kilometres, and, for decades after, hardly a year passed in which some researcher didn’t announce a new type of invisible ray. The world turned out to have aspects hidden from unaided human perception. Was it so unreasonable of people to speculate about what, or who, might lurk in those hidden corners of reality? Were they so gullible, reeling as they were from the mass killings of the first world war, to populate these invisible realms with their dead?
5-1-19 Hormone therapy may improve some symptoms of autism
Hormonal therapies have been found to help communication skills and social interactions in children and men with autism. When the US Food and Drug Administration recently asked people with autism and their caregivers what drugs they would find most useful, the top result was overwhelmingly something that would help with communication and socialisation behaviours, says Paulo Fontoura of the pharmaceutical firm Roche. Some people with autism take ADHD medication for help with attention, or anti-psychotics for help with aggression, but there are no drugs available to help with things like social difficulties. Now two separate studies have tested approaches that target the body’s system for regulating vasopressin, a hormone known to affect social interactions. In the first study, 30 autistic children aged 6 to 12 were given a nasal spray to use daily for 4 weeks. Around half were given a placebo spray, while the others got one containing vasopressin. The children’s social abilities were assessed at the start and end of this period by getting their parents or guardians to answer a standard questionnaire. Doctors also rated the children’s social skills using a standard assessment scale and the children took tests that measured their ability to interpret the emotions of other people based on their facial expressions – a skill often diminished in people with autism. The children who received vasopressin showed a greater improvement in their social abilities after 4 weeks than those who received the placebo, as rated by both doctors and parents. They also improved at recognising the emotional states of faces. The team found that those who naturally had higher concentrations of vasopressin in their blood before the study showed more of an improvement than the others.
5-1-19 Eczema-associated bacteria may be kept in check by a different microbe
Having a diverse mix of bacteria on your skin may help fight off eczema. The finding suggests that microbiome transplants could be a way to treat the skin condition. Eczema, or atopic dermatitis, affects up to 20 per cent of children and around 3 per cent of adults. Previous research has found that people with eczema have a higher abundance of Staphylococcus aureus, a common bacterium found on the skin. Their immune systems also have lower concentrations of certain cells that help build up the skin’s barriers, which allows S. aureus to spread. To figure out why this happens, Richard Gallo at the University of California, San Diego, and his colleagues studied human skin cells from people with and without eczema, and colonised S. aureus bacteria on the skin of mice. In the human cells, they found that S. aureus used a process called quorum sensing, in which the bacterial cells communicate to release damaging toxins and enzymes that help them break the skin’s barrier for the colony to take a stronger hold. At the same time, they found that other bacteria in the Staphylococcus family fought off these toxins by secreting proteins that blocked quorum sensing – essentially stopping messages from passing between the colony of S. aureus. When Gallo and his team isolated a part of these blocker bacteria and put it on the mice whose skin had been inflamed by S. aureus, it protected the skin from further flare-ups. “This shows how bacterial diversity on the skin actually can play a role on inhibiting the skin inflammation caused by Staphylococcus aureus,” says Roxana Daneshjou at Stanford University. “Understanding how the interaction between S. aureus and the skin barrier worsens atopic dermatitis may provide the rationale for future therapeutic intervention.”
5-1-19 Major discovery suggests Denisovans lived in Tibet 160,000 years ago
The first Denisovan remains discovered outside Siberia suggest our extinct cousins lived at extreme altitude in Tibet long before our species made it there. THE first fossil of our cousins the Denisovans ever to be discovered outside Siberia has been identified in Tibet. It hints that fossils from these extinct humans are more widespread than we thought, and may help settle a long-running debate about our origins. Denisovans were discovered in 2010, when the DNA from an ancient bone fragment found in Denisova cave in Siberia was sequenced. Since then, a few other fossil fragments have been uncovered in the cave, and genetic analysis has discovered that many people in China and South-East Asia carry a little Denisovan DNA. This reveals that our ancestors must once have lived alongside and interbred with our cousins. Studies like these also found that people in Tibet carry a specific Denisovan gene that allows red blood cells to cope with low oxygen levels, helping people to live at high altitude. Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, wondered if any human remains previously found in Tibet might really be Denisovan. He and his colleagues examined a jawbone discovered in 1980 in Baishiya Karst cave, in Tibet’s Jiangla river valley. They found that the shape of the jaw and large size of the teeth are different to those of modern humans. Radioisotope dating suggested that the fossil is 160,000 years old at least, which is tens of thousands of years before our own species is thought to have reached the Tibetan Plateau. No DNA could be extracted from the fossil, but analysing collagen protein in its teeth confirmed the jawbone came from a Denisovan, because modern humans and our other extinct cousins the Neanderthals have different genes for collagen (Nature, DOI: 10.1038/s41586-019-1139-x).
5-1-19 A jawbone shows Denisovans lived on the Tibetan Plateau long before humans
All previously known fossils from the mysterious hominids come from a Siberian cave. Denisovans reached what’s now called “the roof of the world” at least 160,000 years ago. Found in a Tibetan Plateau cave, a partial lower jawbone represents a Denisovan who is the oldest known hominid to reach the region’s cloud-scraping heights, researchers report online May 1 in Nature. The fossil suggests that these perplexing, extinct members of the human lineage weathered the plateau’s frigid, thin air long before humans did. Many researchers have assumed that, as far as hominids go, only Homo sapiens settled in that high-altitude, low-oxygen environment, probably no earlier than 40,000 years ago (SN: 12/22/18, p. 6). “It blows my mind that Denisovans lived on the Tibetan Plateau,” paleoanthropologist and study coauthor Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said at an April 29 news conference. Until now, Denisovans were known only from a handful of fossils unearthed in Siberia’s Denisova Cave, and from ancient DNA extracted from one of those bones. Researchers regard Denisovans, who inhabited Denisova Cave from around 300,000 to 50,000 years ago (SN: 3/2/19, p. 11), as close relatives of Neandertals and possibly a distinct Homo species. The jaw’s microscopic protein structure and anatomy peg it as a Denisovan, geoarchaeologist Fahu Chen of the Chinese Academy of Sciences in Beijing and his colleagues report. However, the team wasn’t able to extract any Denisovan DNA from the fossil. Rocky material attached to the bottom of the jaw enabled the calculation of its minimum age.
5-1-19 Denisovans: Primitive humans lived at high altitudes
Scientists have found evidence that an ancient species of human called Denisovans lived at high altitudes in Tibet. The ability to survive in such extreme environments had previously been associated only with our species - Homo sapiens. The ancient ancestor seems to have passed on a gene that helps modern people cope at high elevations. Details of the study are published in the journal Nature. The Denisovans were a mysterious human species living in Asia before modern humans like us expanded across the world tens of thousands of years ago. Until recently, the only fossils came from a few fragments of bone and teeth from a single site in Siberia - Denisova Cave. But DNA had shown that they were a distinct branch of the human family. Now, scientists have identified the first Denisovan fossil from another site. It's a mandible (lower jawbone) discovered in 1980 at Baishiya Karst Cave, 3,280m up on the Tibetan Plateau. A technique called uranium-series dating was used on carbonate deposits on the bone. This yielded a date of 160,000 years ago for the mandible. Co-author Jean Jacques Hublin, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said finding evidence of an ancient - or archaic - species of human living at such high elevations was a surprise. "When we deal with 'archaic hominins' - Neanderthals, Denisovans, early forms of Homo sapiens - it's clear that these hominins were limited in their capabilities to dwell in extreme environments. "If you look at the situation in Europe, we have a lot of Neanderthal sites and people have been studying these sites for a century-and-a-half now. "The highest sites we have are at 2,000m altitude. There are not many, and they are clearly sites where these Neanderthals used to go in summer, probably for special hunts. But otherwise, we don't have these types of sites. "Of the Denisovans on the Tibetan Plateau, he said: "It's a plateau... and there are obviously enough resources for people to live there and not just come occasionally."
5-1-19 The origins of language discovered in music, mime and mimicry
IN THE beginning was the word, and the word was… what? At least since biblical times, we have puzzled over the origins of language. It is, after all, one of the few traits that distinguishes humans from all other animals. Even among the hundreds of other primate species, not one has a communication system that comes close to it in its flexibility and infinite range of expression. Without language, our greatest achievements – including almost everything you see around you – would have been impossible. Unfortunately, this chapter of our story is written in invisible ink. The archaeological record can only offer circumstantial evidence of language until writing began just a few thousand years ago. This has led some to argue that the search for language’s origins is pointless. In 1866, the Paris Linguistics Society even banned discussions of the subject – a prejudice that continued among scientists for nearly 100 years. Fortunately, modern evolutionary theorists are less easily deterred. In work that combines findings from archaeology, anthropology, cognitive science and linguistics, we are finally beginning to track down when and why we found our voice. The idea that is emerging could solve not just one, but two enduring mysteries about human evolution. Let us first consider the timing. Given the dearth of hard evidence, some researchers have claimed that language arrived rapidly 40,000 years ago, when there was a creative explosion of cave paintings and symbolic culture, demonstrating the abstract thinking that language requires. This explanation was never wholly convincing, however. Humans had already migrated and dispersed into separate groups by this point, so it would have required a simultaneous cognitive shift in all the populations across the globe. Sure enough, accumulating evidence about the evolution of key anatomical changes that made us capable of speech leaves little doubt that language must have far deeper roots.
5-1-19 Prehistoric predator fossils found in an underwater cave in Mexico
Fossils of extinct bears and wolves from the end of the last glacial period have been discovered in an underwater cave in Mexico’s Yucatán peninsula. The finds could help us better understand how large prehistoric animals moved around the Americas. With the help of professional divers, Blaine Schubert at East Tennessee State University and his colleagues found the trove of fossils in a cave whose floor is 55 metres below sea level. The site, called Hoyo Negro, would have been dry before melting glaciers filled it with water, helping to preserve the bones there. The divers brought up intact skulls and other bones from two extinct animals. They found fossils from seven individuals of the Arctotherium wingei, a smaller cousin of the giant short-faced bears that lived in South America during the Pleistocene and are thought to be the largest bears ever. Using well-preserved collagen from the roots of a tooth, Schubert and his team dated one bear’s bones to about 11,000 years ago. The team also found fossils of a wolf-like animal called Protocyon troglodytes. “Typically as a palaeontologist, if I’m going on a caving trip looking for ice age animals, I’m lucky to find a tooth,” says Schubert. Hoyo Negro was at the intersection of three passageways through the caves, creating a natural trap where many animals met their death. “This pit had a lot of animal remains. The divers didn’t have to do any digging. These animals were just laying on the surface, and some have been there for 30,000 years.” The fossil record in Central America for this time is quite sparse, so this cache is helping to fill in gaps in our understanding of how these animals migrated throughout the Americas. Before this expedition, it was thought that the bear and wolf-like animal were only present in South America during this period.
5-1-19 Huge whales may have evolved millions of years earlier than we thought
Many species of whale may have become giants much earlier than previously thought. It was believed that the 15 species of baleen whales rapidly jumped in size about 2.5 million years ago, from typically around 5-6 metres to 10-15 metres or as much as 30 metres in the case of blue whales. One dominant explanation was that a sudden shift in the climate changed the food available to them. This meant that there were patches of ocean that were very dense in food, so whales had to eat large amounts at each spot, before travelling long distances to the next one. Now, a new analysis has found that whales could have ballooned in size as far back as 10 million years ago, and gradually rather than suddenly. Felix Marx of Monash University in Australia and his colleagues reached the conclusion after dating a “truly titanic” 26-metre-long blue whale fossil found in Italy and those of several other whales in the Peruvian desert. They compared the dates and sizes with existing fossils. The huge blue whale appears to be about 1.2-1.5 million years old. To get to such a big size by then, whales would have needed a long lead-in time to evolve, says Marx. The implication is that gigantic whales have been shaping the oceans for much longer than we thought. As well as consuming a huge amount of marine life, their sheer size means their travels play a key role in moving nutrients around by mixing water from different depths. “There is a lot more to learn about how gigantic whales have shaped the evolution of the ocean ecosystem,” says Marx.