12-31-18 A skin test after a traumatic event may identify those at risk of PTSD
Only some people who go through a traumatic event get post-traumatic stress disorder (PTSD), but for those who do, the condition can be devastating. A quick skin test could help spot those most at risk so they can be given support earlier. People with PTSD can get nightmares and flashbacks after a traumatic event. Rebecca Hinrichs at Emory University in Georgia and her colleagues suspected that people’s reactions soon after the event might shed light on their risk of developing the condition. To find out, the researchers interviewed 144 people who attended a hospital emergency department after a traumatic experience like being in a car crash. While questioning each person for 5 minutes about their experience, the team placed electrodes on the palm of their hand to monitor their sweat level, which is commonly used to measure how alert someone is to a threat. People who sweated the most during the interview were more likely to be diagnosed with PTSD six months later. However, the test wasn’t perfect: it was good for ruling out people who wouldn’t develop the condition, but it wrongly classed some people as being likely to develop PTSD who didn’t, says Hinrichs. She says that isn’t too much of a problem because the kinds of talking therapy that would be recommended would help people deal with their experience regardless. But Roger Pitman at Harvard Medical School says wrongly telling people they are at risk of PTSD could have downsides. “We don’t know if the harm that would be done by alarming these people is equal to the benefit from treatment.” This test is a useful first step, but we need more accurate measures, says Pitman.
12-30-18 7 things health experts said were good for you in 2018
- Organic foods may reduce cancer risk.
- Holding hands can reduce physical pain.
- Saunas could be as beneficial for your heart as moderate exercise.
- Full-fat dairy may help protect against heart disease and stroke.
- To-do lists could help you sleep.
- Leg exercises: appear to be crucial for brain health.
- Turmeric could help improve memory and ease depression among those with age-related mental decline.
12-30-18 7 things health experts said were bad for you in 2018
- Ibuprofen could contribute to male infertility when taken in large doses on a regular basis.
- Grilled food may increase the risk for high blood pressure.
- Ties constrict blood flow to the brain.
- Disinfectants could make children overweight by altering their gut bacteria.
- Bottled water almost always contains microplastics.
- Staying up late could reduce your lifespan.
- Following sports makes you miserable.
12-30-18 The 5 biggest scientific breakthroughs of 2018
From cloned monkeys to the birth of a planet.
- Cloning monkeys: More than 20 years after researchers cloned Dolly the sheep, scientists in China cloned two monkeys — the first time the technique had been used on primates.
- Was there life on Mars? NASA scientists discovered the strongest evidence yet that microbial life might once have thrived on Mars.
- Helping paraplegics walk: Three people paralyzed from the waist down are walking again after having electrodes implanted in their spines.
- Treating muscular dystrophy: Scientists corrected the mutations behind a form of muscular dystrophy in dogs, raising hopes that the same can be done in humans.
- Witnessing the birth of a planet: Astronomers this year captured the first-ever image of a new planet being formed.
12-30-18 How ancient DNA may rewrite prehistory in India
New research using ancient DNA is rewriting prehistory in India - and shows that its civilisation is the result of multiple ancient migrations, writes Tony Joseph. Who are the Indians? And where did they come from? In the last few years, the debate over these questions has become more and more heated. Hindu right-wingers believe the source of Indian civilisation are people who called themselves Aryans - a nomadic tribe of horse-riding, cattle-rearing warriors and herders who composed Hinduism's oldest religious texts, the Vedas. The Aryans, they argue, originated from India and then spread across large parts of Asia and Europe, helping set up the family of Indo-European languages that Europeans and Indians still speak today. As it happens, many 19th Century European ethnographers and, of course, most famously, Adolf Hitler, also considered Aryans the master race who had conquered Europe, although the German leader considered them to be of Nordic lineage. When scholars use the term Aryan, it refers to a group of people who spoke Indo-European languages and called themselves Aryans. And that is how I have used it in this article. It does not refer to a race, as Hitler used it or as some in the Hindu right wing use it. Many Indian scholars have questioned the "out of India" thesis, arguing that these Indo-European language speakers - or Aryans - were possibly just one of many streams of prehistoric migrants who arrived in India after the decline of an earlier civilisation. This was the Harappan (or Indus Valley) civilisation, which thrived in what is now north-western India and Pakistan around the same time as the Egyptians and Mesopotamians. However, Hindu right-wingers believe the Harappan civilisation was also an Aryan or Vedic civilisation. Tensions between the two groups backing these opposing theories have only increased in the last few years, especially since the Hindu nationalist Bharatiya Janata Party (BJP) came to power in India in 2014. Into this long-running dispute has now stepped the relatively new discipline of population genetics, which has started using ancient DNA to figure out when people moved where.
12-26-18 Rich people give more to charity when you make them feel powerful.
APPEALING to wealthy people’s sense of personal power rather than their community spirit seems to encourage them to give more money to charity. Psychologists already knew that rich people value their individual ability to control events more than lower-income earners do, says Ashley Whillans at Harvard University. Appealing to this independent mindset encouraged wealthy people to donate more money to a charity aimed at ending poverty, found Whillans and her colleagues. That work was published in 2017. The team has now tested whether fundraising appeals framed in this way increased the generosity of wealthy graduates of an Ivy League business school in the US, whose average starting salaries were in excess of $100,000 per year. The researchers sent letters to more than 12,000 alumni asking them to donate to the school. The letters started with one of two sets of words to appeal for their support: “Sometimes, one person needs to come forward and take individual action” or “Sometimes, one community needs to come forward and support a common goal”. Among the 4 per cent who donated, those who received the message that focused on individual action gave an average of $432. In contrast, those who got the more community-minded appeal contributed $270 on average (PLoS One, doi.org/cx4m). “We think that giving high-income earners a sense of control makes them want to give more,” says Whillans.
12-25-18 Lost ‘Darwinia’ islands could be origin of species in the Galapagos
MILLIONS of years before the Galapagos Islands existed, there was another archipelago in the same stretch of water off the west coast of South America. And it seems those long-vanished lands probably shaped the evolution of some of the unusual Galapagos wildlife that later inspired Charles Darwin’s theory of evolution. Today’s archipelago probably owes its existence to a nearby geological phenomenon, a plume of unusually hot rock rising from deep in Earth’s interior. When the plume meets the crust beneath the Pacific Ocean, it triggers intense volcanic activity, which forms underwater mountains that can grow tall enough to rise above sea level and become islands. The parts of the Galapagos that lie near the plume today are about 3 million years old. But geologists think the plume is much older, and has been forming volcanic islands for much of the past 20 million years. These have since been dragged to the east and northeast of the Galapagos by drifting tectonic plates. During this process, almost all of the island-volcanoes became inactive and sank below the water, where their remains can be found. For the first time, researchers have worked out how big these lost lands were. Felipe Orellana-Rovirosa and Mark Richards at the University of California, Berkeley, used data on the rate at which they sink to work out how much land was above the waves at various points over the past 20 million years. They say that there is likely to have been a Galapagos-like archipelago off the west coast of South America for most of this time. Their work suggests that 16.5 million years ago, the land area of the archipelago was 22,500 square kilometres, more than twice that of the current chain. Some of the lost islands had peaks that may have risen as much as 500 metres above sea level. The findings were presented at a conference of the American Geophysical Union in Washington DC.
12-24-18 Pompeii horse found still wearing harness
The remains of a horse still in its harness have been discovered at a villa outside the walls of Pompeii, in what archaeologists are hailing as a find of "rare importance". The horse was saddled up and ready to go, possibly to help rescue Pompeians fleeing the AD79 eruption of Mount Vesuvius that buried the town in ashes. It was found with the remains of other horses at the Villa of the Mysteries. The villa belonged to a Roman general or high-ranking military magistrate. Mount Vesuvius buried Pompeii and other nearby towns under millions of tonnes of volcanic debris. Archaeologists at the luxurious Villa of Mysteries (Villa dei Misteri) overlooking the sea have already found wine presses, ovens and extraordinary frescoes. The latest discovery came during an excavation of a stable at the villa to the north of Pompeii, according to Massimo Osanna, the director of Pompeii's archaeological park. The apparently well-groomed horse, along with a saddle and a harness with fragments of wooden and bronze trimmings, was found alongside two other horses. The horses had all come to a "fierce and terrible end", Mr Osanna said, suffocated by ashes or by the boiling vapours from Vesuvius's ash cloud.
12-23-18 The art of stimming
My son stims — he performs repetitive motions in order to generate sensory inputs that he experiences as fun, aesthetically pleasing, soothing, exciting, or otherwise necessary. The word comes from the clinical term, "self-stimulatory behavior," but there's no need to be that clinical about it. His stimming is beautiful. To get him to stop stimming would require intensive coercion that, even if successful, would likely result in irreparable psychological harm. Meanwhile, for over 50 years, therapists who practice something called "applied behavioral analysis" (ABA), an approach that has generated a massively well-funded industry, have tried to eradicate these types of behaviors in autistic children. In the past, therapists used cattle prods or other methods of causing pain in order to coerce compliance. Some schools still use electric shocks, but, today, most ABA therapists have switched to withholding rewards in order to eliminate stimming and other behaviors deemed barriers to inclusion. An autistic child, such therapists say, must have quiet hands and be "table ready." Friendly coercion is still coercion. Meanwhile, my son stims. My son has been stimming since his first year of life, although we have only recently begun using that language to describe it. He has Down syndrome, but in the last few years, it's become clear that he is also autistic. The two conditions co-occur fairly commonly. As an infant, he would rock back and forth on his hands and knees in his crib. As he aged, he learned to do the same rocking motion on beds, couches, or the floor, while listening to music, especially when tired. When he's not stimming with his whole body, he likes to shake something repeatedly, usually with his left hand. I remember a succession of toys: a firefly, a rat puppet, and then a series of stuffed white tigers that had to be replaced as their tails ripped off. At some point he found his true muse in plastic Mardi Gras beads. Today he is highly particular about his beads, weighing them experimentally with little practice shakes before selecting one string that he will use until it breaks. He moves through his world accompanied by the soft click of beads as they dance.
12-21-18 Americans are sleeping less than they were 13 years ago
Technology use and stress could be contributing to the short-sleep trend. Nearly one-third of American adults sleep less than six hours each night, a broad new survey shows. Among nearly 400,000 respondents to the annual National Health Interview Survey, 32.9 percent reported this short sleep in 2017 — up from 28.6 percent in 2004 when researchers began noticing a slight drop in sleep time. That’s a 15 percent increase representing “more than 9 million people, which is about the population of New York City,” says coauthor Connor Sheehan, a sociologist at Arizona State University in Tempe. Analysis of the annual survey results — accounting for the U.S. population’s age distribution as well as respondents' marital status, income, employment and lifestyle — suggests people have been sleeping significantly less from 2013 onward, especially black adults, the researchers report online November 17 in Sleep. In 2017, 40.9 percent of black Americans were likely to report short sleep, as were 30.9 percent of whites and 32.9 percent of Hispanics, the researchers calculate. Americans were more likely in 2017 to report sleeping less than six hours a night than in 2004, but the trend increased most among black and Hispanic people than among white respondents. (Webmaster's comment: Black and Hispanic people are being threatened by whites all the time. It's no wonder they get less sleep!)
12-21-18 Gel made from birch bark reduces skin scarring from cuts and burns
A naturally-occurring chemical in birch bark helps skin wounds mend faster with less scarring, a clinical trial has found. The bark of birch trees has long been known for its healing properties. This inspired German pharmaceutical company Birken AG – now owned by Amryt Pharma – to develop and test whether a gel made from birch bark extract might help treat wounds. The company previously showed that the gel sped up the wound healing process in patients who had patches of skin cut out for surgical graft procedures. Now, Quentin Frew at the St. Andrews Centre for Plastic Surgery and Burns in the UK and his colleagues have shown that the gel is also useful for treating burns, in a study funded by the pharmaceutical company. The researchers recruited 57 patients with superficial burn wounds caused by fire, scalding or touching hot objects. In each case, they applied the birch bark gel to one half of the wound and a standard burn gel to the other half at least once every two days until healing was complete. In 86 per cent of patients, the wound area treated with the birch bark gel healed faster than the area treated with the standard gel, with an average reduction in closure time of about one day. After 12 months, the texture, pigmentation and redness of the birch bark-treated areas were also rated as being closer in appearance to healthy skin. The main ingredient in birch bark – a chemical called betulin – appears to speed up the healing process by encouraging skin cells to grow and migrate across the wound, says Frew. “Anything that heals the skin quicker reduces the risk of long-term scarring,” he says.
12-21-18 Hominin v monkey deathmatch ended in a draw when they fell down a hole
Was it a fight to the death? Little Foot, an ancient hominin who lived in what is now South Africa 3.67 million years ago, may have died in a battle for food with a large male baboon-like monkey after falling down a hole. Little Foot is an extraordinary find. As New Scientist revealed earlier this month, she may belong to a distinct species of hominin – Australopithecus prometheus – that was named in 1948 on the basis of other fossils. Judging by Little Foot’s features, including her flat face, A. prometheus could have been an ancestor to a group of heavily built hominins called Paranthropus which lived alongside early members of our human genus. Her skeleton was found in Sterkfontein Cave to the northwest of Johannesburg. It is more than 90 per cent complete, and excavating her fragile bones took 14 years. But as the excavators worked away in the cave, they realised that Little Foot wasn’t alone. Beneath her pelvis, Ronald Clarke at the University of the Witwatersrand in South Africa and colleagues found a skull belonging to an extinct baboon-like monkey species called Parapapio broomi. Then, beneath Little Foot’s right arm they found a Parapapio shinbone. And intermingled with the bones in Little Foot’s spine were two Parapapio vertebrae. Finally, next to Little Foot’s left thigh bone was a Parapapio arm bone. It’s likely that all of the bones belonged to the same individual: a male that was at least as large, if not larger, than a modern male baboon. Clarke’s team say that raises an interesting idea — that the two fought before falling their death.
12-21-18 Pterosaurs may have been covered in fur and primitive feathers
Scientists find structures similar to hair and plumes on the flying reptiles. Think of pterosaurs, the flying reptiles that were distant cousins to the dinosaurs, and you may imagine a fearsome, leathery, winged creature. But new fossil evidence suggests at least some pterosaurs were soft and fluffy, covered in a diverse array of fibrous structures including possible precursors of feathers, scientists report online December 17 in Nature Ecology & Evolution. The discovery adds to a growing body of evidence that featherlike structures may have been more common during the time of the dinosaurs than once thought. Researchers led by paleontologist Zixiao Yang of Nanjing University in China identified four types of filaments called pycnofibers on two fossil pterosaur specimens, both dated to around 165 million to 160 million years ago. One of the pycnofiber types was a single, smooth, filament that covered the bodies of both animals and may have kept them warm, like fur. The other three types, however, all showed branching structures extending out from a central filament — a key feature of feathers, the researchers say.
12-20-18 Dream on: My year pursuing the third state of being
Dreaming can bring extraordinary ideas – if you can remember them. The 3rd article of our 12 Days of Culture explores the weird world of hypnagogic dreaming. “They called it REM sleep for years,” Ursula Le Guin wrote, in her novel The Lathe of Heaven. “It’s a hell of a lot more than that, though. It’s a third state of being.” Dreaming represents a state in between consciousness and unconsciousness, and this year I’ve been trying to get on top of what we know about this universal and mysterious experience. I went to a dream conference in Arizona, and spent the night in a dream lab in Swansea, UK. There I learned about research providing evidence, for the first time, that explains the purpose of dreaming. But while scientists are learning more about the function of dreams and of sleep, I’ve been particularly drawn to the mysterious border state between wakefulness and slumber. Sleep scientists call this transient period the hypnagogic state, a highly creative state that has been actively pursued by artists and scientists over the years. Two hundred years ago, Mary Shelley published Frankenstein, a masterpiece written when she was only 19. The book’s impact is still being felt: when gene-edited children were born in China in November many commentators reached for the Frankenstein comparison. But how did Shelley conceive her idea? She had absorbed huge amounts of modern science from discussions with her husband, Percy Shelley, and their friend George Gordon (Lord) Byron, when they were living in a villa on the shore of Lake Geneva, Switzerland. They spoke, among other things, of the origins of life and the feasibility of reanimating a corpse with electricity. Mary’s mind was buzzing with these ideas, and one night the trio decided to each write a horror story. As Mary fell asleep, the idea for Frankenstein came to her in what she called a “waking dream”.
12-20-18 Starchy food may reduce autoimmune reactions in people with lupus
Starchy food may ease autoimmune reactions for people with lupus. Experiments with mice show that certain gut bacteria exacerbate the disease, but consuming starch can halt their growth. Lupus is a disease where a person’s immune system attacks their own body. Suspecting the condition could be affected by gut bacteria, Martin Kriegel at Yale University and his colleagues gave antibiotics to mice with lupus to deplete the bacteria in their gut. The results was that these mice then had less severe autoimmune responses and were twice as likely to survive than those that hadn’t had antibiotics. The team found that the unhealthy mice had elevated levels of lactobacillus, hinting it may be involved with lupus. The bacteria also spread to their intestines, livers and spleens, which doesn’t happen in healthy mice. This may explain why lupus involves systemic immune responses in many organs in addition to the gut, says Kriegel. “Lactobacillus is an unexpected candidate,” he says. It’s found in healthy people and is often promoted as good bacteria in probiotics, but here it’s acting differently, he says. Resistant starch, a dietary fiber found in beans and potatoes, can influence the bacteria in our guts. Kriegel wanted to know if it would play a role in lupus too, so the team fed resistant starch to mice with lupus for seven months. The result was that there was less growth of lactobacillus in their intestines, fewer bacteria escaped to other body parts, and overall their conditions improved. “It remains to be shown if a starch diet can benefit human patients,” Kriegel says. “But this would be the long-term goal.”
12-20-18 There may be a link between erectile dysfunction and type 2 diabetes
A study of thousands of men links type 2 diabetes with erectile dysfunction. The research opens up the possibility that living a healthier lifestyle could help reduce the risk of erectile dysfunction, as it does with type 2 diabetes. A team from the University of Oxford and the University of Exeter analysed genetic data from 6000 men. They looked at the complex correlations between diabetes and other aspects of the body, and found that having a genetic predisposition to type 2 diabetes was associated with erectile dysfunction. It is too soon to say if this is a causal relationship. Very few clinical trials have found that improved glucose control leads to problems of erectile dysfunction, which limits the conclusions that can be drawn about whether treatment of diabetes is likely to have an impact on erectile dysfunction risk. “Erectile dysfunction affects at least one in five men over 60, yet up until now little has been known about its cause,” says Anna Murray at the University of Exeter, who co-lead the study. The results “may mean that if people can reduce their risk of diabetes through healthier lifestyles, they may also avoid developing erectile dysfunction,” she says. The study is published in the American Journal of Human Genetics.
12-20-18 More plants survived the world’s greatest mass extinction than thought
Fossils in a Jordanian desert reveal plant lineages that didn’t perish in the Great Dying. Some ancient plants were survivors. A collection of roughly 255-million-year-old fossils suggests that three major plant groups existed earlier than previously thought, and made it through a mass extinction that wiped out more than 90 percent of Earth’s marine species and roughly 70 percent of land vertebrates. The fossils, described in the Dec. 21 Science, push back the earliest records of these plant groups by about 5 million years. “But it's not just any 5 million years — it's those 5 million years that span the Permian-Triassic boundary,” says study coauthor Benjamin Bomfleur, a paleobotanist at the University of Münster in Germany. The find adds to the growing list of land plants that survived the catastrophe known as the Great Dying, the world’s greatest mass extinction, which occurred about 252 million years ago at the end of the Permian Period. Bomfleur and his colleagues found the new fossils in desert rock outcroppings near the Dead Sea in Jordan. Paleontologists have been searching those rock formations for decades. “Every time we go, we find new fossils,” he says. At the time these fossils formed, the area had a tropical climate but with prolonged dry periods. Those conditions aren’t good for forming fossils. But surprisingly, these fossils are exceptionally well preserved, Bomfleur says. He and his colleagues were able to wash the rocks with an acid to extract waxy plant cuticles embedded within. The cuticle preserves a mold of microscopic features on the surfaces of fronds or leaves, and those details helped the scientists identify the plant species more accurately.
12-20-18 The battle over new nerve cells in adult brains intensifies
New methods are needed to settle the debate. ust a generation ago, common wisdom held that once a person reaches adulthood, the brain stops producing new nerve cells. Scientists countered that depressing prospect 20 years ago with signs that a grown-up brain can in fact replenish itself. The implications were huge: Maybe that process would offer a way to fight disorders such as depression and Alzheimer’s disease. This year, though, several pieces of contradictory evidence surfaced and a heated debate once again flared up. Today, we still don’t know whether the fully grown brain churns out new nerve cells. This year’s opening shot came March 7 in a controversial report in Nature. Contradicting several landmark findings that had convinced the scientific community that adults can make new nerve cells, researchers described an utter lack of dividing nerve cells, or neurons, in adult postmortem brain tissue (SN Online: 3/8/18). A return volley came a month later, when a different research group described loads of newborn neurons in postmortem brains, in an April 5 paper in Cell Stem Cell (SN: 5/12/18, p. 10). Scientific whiplash ensued when a third group found no new neurons in postmortem brains, describing the results in the July Cerebral Cortex. Still more neuroscientists jumped into the fray with commentaries and perspective articles. This ping-ponging over the rejuvenating powers of the brain is the most recent iteration of a question that still hasn’t been answered. The first encouraging news about brain cells came in 1998 when scientists looked at the brains of people who had been treated with a compound that marks DNA in newly born neurons. The compound turned up in cells in the adult hippocampus, a brain structure important for learning and memory. Those results, along with a 2013 study that used a different tagging method, suggested that the brain can pump out neurons throughout life.
12-19-18 The more pets you meet as a baby, the lower your risk of allergies
Pets really do seem to prevent allergies: the more cats or dogs you live with as an infant, the lower your chance of developing asthma, hay fever or eczema. Some studies have found that having a pet early in life protects from allergies later in childhood. Bill Hesselmar at the University of Gothenburg, Sweden, and colleagues wondered if having more than one pet would increase the benefit. They looked at data from two previous studies. The larger of the two included data from 1029 children aged seven to eight. The incidence of allergies was 49 per cent in children who had spent their first 12 months of life in a home with no pets. This fell to 43 per cent in children who as babies had lived with one pet, and 24 per cent for children who had lived with three pets. Two of the children had lived with five pets – neither of them had allergies. The second study tracked 249 children from birth. After eight or nine years, the rate of allergies was 48 per cent for children who had had no exposure to pets in their first year, 35 per cent for children with exposure to one pet and 21 per cent for children who had lived with two or more pets. This shows that there is a dose-dependent relationship: more exposure to pets means more protection. That could explain why some previous studies did not find a link. “A dog or a cat that is seldom inside the house, or seldom in close contact with the child, may not be protective,” says Hesselmar. It also rules out the possibility that the link can be explained by selection bias: the result of families with allergies choosing not to have a pet. Previous studies have found that children who grow up on a farm with livestock have a lower risk of allergies. Hesselmar thinks having multiple pets is like living on a “mini-farm”, with lots of exposure to allergens.
12-19-18 Mice lack stem cells in the heart needed for self-repair
The same may be true for people. There’s some bad news for people who have suffered heart attacks: Healing may not come from within. Researchers have debated for years whether hearts have their own stem cells. If they existed, those cells could produce new heart muscle cells and might help the organ repair itself after injury. Now that debate may finally be over. After following the fate of dividing cells in the hearts of mice, researchers have concluded that there are no heart stem cells. Instead, heart attacks and other injuries to the organ signal immune cells and scar-forming cells called fibroblasts to divide and attempt to close the wound, the team reports online December 7 in the Proceedings of the National Academy of Sciences. Human hearts probably also lack stem cells, evidence suggests. “This study is fairly definitive that there is not a population of stem cells within the heart that gives rise to new muscle,” says Deepak Srivastava, a cardiologist and developmental biologist at the Gladstone Institutes in San Francisco who was not involved in the study. Other researchers agree the study seems to settle the matter. “It can certainly seem like this is a letdown,” says Ronald Vagnozzi, a cardiac cell biologist at Cincinnati Children’s Hospital. On the bright side, “this paper is a rich resource of information” that may help scientists better understand what happens in the heart during development and after a heart attack, he says. That knowledge may help researchers limit heart attack damage.
12-19-18 DNA from 6000-year-old chewing gum reveals how an ancient woman lived
She dined on duck, eels and hazel nuts, before settling down to a spot of tool-making, using birch bark pitch as a glue for sticking stone blades to wooden handles. The dark-haired, dark-skinned woman chewed the pitch for a while to make it more pliable, then for some reason spat out a wad without using it. Six thousand years later archaeologists have extracted DNA from the discarded lump to shed light on the woman’s diet, appearance, and ancestry. They have named her Lola, as it was found on the island of Lolland, part of modern-day Denmark. “It’s amazing – I know what she’s been eating, what colour her eyes were, what colour her hair was,” says Søren Sørensen at the Museum Lolland-Falster, which is running the excavation. “It’s like standing face to face with a stone age person.” Analysis of DNA from ancient human remains such as bones and teeth has been growing in recent years, but this work is among the first to analyse prehistoric “chewing gum”. Birch pitch, made by heating the tree’s bark until it forms a black tar, was used by many ancient people as glue, for instance to stick arrow heads to their shafts or knife blades to their handles. Small lumps of pitch have been recovered from several prehistoric sites across Europe, often with clear tooth marks. Chewing the goo would have made it more pliable. But it also has antiseptic properties so people may have chewed it to help heal mouth wounds, or even for the same reasons we chew gum today – out of hunger or boredom. Some of the indentations are made by the small teeth of children. “Once you see kids’ teeth imprints you think it’s no different to today when kids go around spitting out chewing gum,” says Natalia Kashuba of the University of Oslo. “I want to believe that it’s also recreational, but there’s no way to know.”
12-19-18 E-cigarettes caught fire among teens
U.S. Food and Drug Administration set new limits on sales. On November 15, Scott Gottlieb, commissioner of the U.S. Food and Drug Administration, announced new sales restrictions on certain e-cigarette flavors preferred by teens. The move was a response to a worrying rise in vaping among adolescents in the last year. “E-cigs have become an almost ubiquitous and dangerous trend among teens,” he warned, calling it an “epidemic” in a September speech. His claim is no exaggeration. In 2018, 20.8 percent of high schoolers surveyed said they had used e-cigarettes at least once in the last 30 days, up from 11.7 percent in 2017. That is a 78 percent jump in e-cig use, based on data from the National Youth Tobacco Survey (SN Online: 11/16/18). On December 17, the 2018 Monitoring the Future survey, a national substance use questionnaire of 8th, 10th and 12th graders, reported similar increases in the New England Journal of Medicine. That spike may be due to use of the top-selling e-cigarette brand, Juul. One of a new class of e-cigarettes called pod-mods, a Juul vaporizes a prefilled pod of flavored liquid that contains a higher concentration of nicotine than other e-cigs. The palm-sized device resembles a USB flash drive and can be used discreetly, as it doesn’t produce much vapor. A survey of 437 California high school students found that teens are more likely to become regular users of Juuls than of other e-cigs (SN Online: 10/23/18). Teens already have their own term for vaping: juuling. A person who inhales all of the nicotine in a 5 percent nicotine Juul pod (a 3 percent version is also available) takes in about the same amount as a smoker would get from 26 to 40 cigarettes, says toxicologist Gideon St. Helen of the University of California, San Francisco.
12-19-18 Exercise may lower high blood pressure as much as medication
Exercise could be just as effective in lowering high blood pressure as prescribed medication. Researchers pooled data from nearly 400 trials and found that for people with high blood pressure, activity such as walking, swimming and simple weight training seemed to be just as good as most drugs used to treat it. However, the team warns people should not stop taking their medication until further studies are carried out. Huseyin Naci at the London School of Economics and his colleagues analysed data from 194 trials looking at the impact of drugs on lowering high blood pressure, and 197 trials testing the impact of structured exercise. The trials involved a total of nearly 40,000 people, but none of them directly compared exercise against medication. The team found that blood pressure was lower in people treated with drugs than in those following structured exercise programmes. But when the analysis was restricted to just those with high blood pressure, exercise seemed to be just as effective as medication. A combination of endurance exercise, such as cycling and walking, and dynamic resistance training, such as weight training, was found to be particularly effective in reducing blood pressure. “We don’t think, on the basis of our study, that patients should stop taking their antihypertensive medications,” says Naci. It’s one thing to recommend that physicians start prescribing exercise to their patients, but we also need to ensure that the patients that have been referred to exercise interventions can adhere to them and so really derive benefit, he says.
12-19-18 The sugar that makes up DNA could be made in space
Lab experiments simulating the iciness and radiation in a star nursery created deoxyribose. Parts of DNA can form in space. For the first time, scientists have made 2-deoxyribose, the sugar that makes up the backbone of DNA, under cosmic conditions in the lab by blasting ice with radiation. The result, reported December 18 in Nature Communications, suggests that there are several ways for prebiotic chemistry to take place in space, and supports the idea that the stuff of life could have been delivered to Earth from elsewhere. “It tells us that this process happens everywhere, at least in our galaxy,” says astrochemist Michel Nuevo of NASA’s Ames Research Center in Moffett Field, Calif. Nuevo and his colleagues cooled ices of frozen water and methanol to about –260° Celsius inside a vacuum chamber and blasted the ice with ultraviolet light, mimicking the conditions found in interstellar clouds. Warming the irradiated ices simulated what happens when a young star is born. After analyzing the ice’s contents, the team identified 2-deoxyribose, as well as several other kinds of sugars made in similar experiments in the past (SN: 4/30/16, p. 18). Experiments that had made ribose, the sugar of RNA, suggested that the sugars could be built up from reactions involving the simple molecule formaldehyde, which has been found in comets (SN Online: 10/23/14). But those reactions always lead to sugars with more oxygen molecules than deoxyribose has, Nuevo says. “The fact that we made deoxyribose points to another kind of mechanism.” Nuevo and his colleagues also found simple deoxy sugars in meteorite samples, but not deoxyribose. That could suggest that, although deoxyribose can form in ices that predate stars, the sugar is not stable in the rocks that ultimately form planets.
12-19-18 The very first dinosaurs probably evolved in South America
Dinosaurs were southerners. The famous group dominated the world for tens of millions of years and left behind fossils on every major landmass, which has led to some confusion over where the very first dinosaurs were born. Two new studies pile on the evidence that the earliest dinosaurs lived in South America or one of the other southern continents. When the first dinosaurs appeared, roughly 240 or 250 million years ago, Earth’s continents were united in the supercontinent Pangaea. In principle dinosaurs could have arisen in any corner of Pangaea. However, given that many of the earliest dinosaur fossils have been unearthed in South America, Africa and other regions that formed southern Pangaea, palaeontologists have begun to suspect that this region was the cradle of dinosaur evolution. Last year, though, a high-profile study suggested an alternative. A team of British palaeontologists led by Matthew Baron at the University of Cambridge argued for the most radical overhaul of the dinosaur evolutionary tree in 130 years. In their new tree, some of the fossils that lie closest to the base of the dinosaur group come from Europe – such as one called Saltopus that was found in Scotland. The team said this might suggest the dinosaur cradle was in northern Pangaea. Now, a team led by Júlio Marsola at the University of Sao Paulo, Brazil, has looked at the subject in more detail. They examined six dinosaur evolutionary trees published over the last 20 years – including the radically different one published last year. Then they looked at the geographical distribution of the species near the base of the dinosaur family in each tree. Almost without exception, the evolutionary trees suggest dinosaurs came from southern Pangaea.
12-18-18 2019 Preview: Experimental vaccine could let coeliacs eat gluten
Bread and pasta may be back on the menu for people with coeliac disease participating in a clinical trial next year. Coeliac disease makes you unable to eat foods containing gluten without experiencing an immune reaction that damages your gut and can cause vomiting, diarrhoea and fatigue. A vaccine called Nexvax2 could change that. It contains synthetic fragments of gluten that can be recognised by the immune system, but don’t trigger a full immune reaction when introduced in gradually increasing doses. This teaches a person’s immune system to see gluten as harmless. The vaccine has performed well in five small clinical studies. In one of these, eight people with coeliac disease given the vaccine were each able to eat nine gluten-containing cookies over three days without feeling sick or showing signs of inflammation in blood tests. A larger trial of the vaccine in 146 people with coeliac disease is now under way and due to finish at the end of 2019. Half of the participants will be injected with progressively stronger doses of the vaccine twice a week, for 16 weeks. The other half will get placebo injections instead. The efficacy of the vaccine will be assessed by giving all participants a smoothie to drink containing as much gluten as in two pieces of bread. Each person’s symptoms and inflammatory blood markers will then be monitored. Based on the results of earlier trials, Ken Truitt at ImmusanT, the US company developing the vaccine, is optimistic it will work. It could change the lives of the 1 per cent of people who have coeliac disease and currently have to remain vigilant for all sources of gluten, like wheat, barley and rye, he says.
12-18-18 2019 Preview: Teeth will reveal our species’ deep evolutionary past
Next year, we will start to learn what a host of ancient animal and early human remains really are, thanks to new techniques for identifying even fragmentary pieces. Over the past decade, DNA analysis has overturned our ideas of human evolution. It has revealed that humans interbred with Neanderthals, and unveiled a hitherto-unknown group called Denisovans. But it has limits. The DNA in remains doesn’t survive long when conditions are hot or wet, so we won’t get much from the tropics. Even in ideal conditions, DNA breaks down. The oldest DNA yet recovered comes from a horse that lived 700,000 years ago. However, proteins can survive longer. One example is the collagen in bone, which can now be used to roughly identify organisms. The method is fast and cheap. Another technique is more precise. Enamel in teeth also contains proteins, which can reveal an animal’s species. In September this year, Enrico Cappellini at the Natural History Museum of Denmark used the method on remains of extinct rhinos and figured out how the species were related. This proof of concept was huge, because teeth are the most frequently preserved body part. The technique should shed light on human evolution. “We have all these exciting fossils coming out of Africa, but we have no DNA to go along with them,” says Samantha Brown at the Max Planck Institute for the Science of Human History in Germany. Newly discovered species like Homo naledi and Australopithecus sediba cause confusion because we can’t tell where they fit in our family tree. “Enamel could be useful for putting together those trees,” she says.
12-18-18 2019 Preview: People will receive transfusions of artificial blood
Blood transfusions save lives, but supply doesn’t always meet demand, which can lead to fatal consequences. Soon, we will be able to end that problem by making blood in the lab on demand, with no donors required. Transfusions depend on armies of donors and complex networks for collecting and storing donated blood. Some countries are unable to build the infrastructure required to do this. Even in developed nations, hospitals can run short of supplies for people belonging to particular blood groups. Such problems would be solved if we had a way to make effective artificial blood. One such type of lab-made blood will be tested in people for the first time in 2019. Blood has a lot of functions, but the most crucial is bringing oxygen to the tissues of the body. This job is done by red blood cells, which are packed with an oxygen-binding protein called haemoglobin. There have been several attempts to make artificial haemoglobin or to use animal versions of the protein, but these have hit problems, prompting researchers to try another angle: producing whole red blood cells instead. In the body, these cells are made by a kind of stem cell that normally lives in bone marrow. To make new red blood cells in the lab, Allison Blair at the University of Bristol, UK, and her colleagues have extracted some of these stem cells and nurtured them so they multiply and start to produce functioning red blood cells. Next year, 10 healthy volunteers will be injected with just a teaspoon each of fluid containing these cells. The cells will be labelled with a mildly radioactive tracer, to see how long they survive in the body compared with ordinary cells. In a further advance, to cut out the need for a continual supply of stem cell donors, another team has developed a way to make these stem cells live forever in the lab. “That gives you almost a limitless supply,” says Blair.
12-18-18 2019 Preview: DNA testing will lead to a decline in genetic disorders
A marked fall in the number of babies born with inherited illnesses is possible, as a pre-pregnancy DNA test is used more widely. The test checks whether prospective parents carry genes that, if both pass a copy to their child, will cause disease, known as a recessive condition. The test is usually only offered to people who know that recessive disorders such as cystic fibrosis run in their family. But most carriers of these genes don’t have any such warning, says Alison Archibald at Victorian Clinical Genetics Services in Australia. In 2019, the country will start a trial, offering free tests to 10,000 couples regardless of family history, screening for 500 illnesses. If it leads to fewer babies born with these diseases, it may be offered nationwide. Since 2017, the American College of Obstetricians and Gynecologists has also recommended that all couples planning families have carrier tests for two of the most common recessive conditions: cystic fibrosis and spinal muscular atrophy. In a study of 12,000 people in Australia, Archibald’s team found that one in 20 people carried genes for cystic fibrosis or spinal muscular atrophy. Of these, one in 40 had a partner who was also a carrier, giving them a one in four chance of having an affected child. Screening on a national scale could see rates of genetic conditions fall sharply. Couples who test positive may choose to undergo IVF, allowing them to select embryos that are free of the condition. Couples are also increasingly opting for early fetal screening in pregnancy. Since 2011, an early-pregnancy blood test for Down’s syndrome and other chromosomal disorders has been done by an estimated 10 million women worldwide.
12-18-18 Toys are us: How childhood objects may have shaped human history
Tantalising evidence hints that key human innovations including the wheel and weaving were the outcome of, quite literally, child's play. FEW origin stories are as perplexing as the invention of the wheel. Thomas Edison famously claimed that genius is 1 per cent inspiration and 99 per cent perspiration – for our ancestors, it was the 99 per cent that posed a problem. Even after they realised they could move objects with a rolling motion, they needed to refine their engineering skills enough to build a wheel that actually worked. “Making a full-scale wheel takes a lot of physical resources, it takes a lot of time, it takes a lot of skill,” says Felix Riede, an archaeologist at Aarhus University in Denmark. But how could any prehistoric inventor have afforded to pour so much blood, sweat and tears into experimentation when there were mouths to feed? Inspired by his young son, Riede has come up with a surprising solution. He thinks that the skills required for technological innovation were honed through play. While the adults went about the serious work of ensuring the group’s survival, youngsters naturally experimented with the objects around them. If Riede is right, some of humanity’s most important inventions – including the wheel, weaving and projectile weapons – have their roots in children’s toys. The idea that toys shaped humanity builds on a growing understanding of just how important play has been to the evolution of our brains. Analyses of remains such as teeth from ancient hominins show that our species, Homo sapiens, enjoys an unusually long childhood. An extended infancy gives more time for imaginative play, which has been shown to train many important cognitive skills, including counterfactual thinking – the ability to ask “what if…” – and the capacity to envisage different scenarios. According to April Nowell at the University of Victoria in Canada, this might explain why we are the only species with such a rich symbolic and artistic culture.
12-18-18 Cheers! Saying thanks is good for you and those around you
The fad of privately recording your gratitude in a journal was all the rage, but it turns out if you actually pass on your thanks to others, the benefits are multiplied. WITHOUT meaning to sound ungrateful, it really is the comedown after the festive cheer: the dreaded thank-you notes. Perhaps you agonise over how to make each sound genuine. Maybe you put off the chore for so long you end up not bothering, or simply feel they are an outdated waste of time. Then there is the skill of mustering the convincing faux-thanks for unwanted gifts. If writing thank-you letters is a task you readily dismiss, you aren’t alone. It turns out we express our gratitude more rarely than you might assume. But, however you feel about those festive notes, it is time to knuckle down. Because saying thanks could be the best gift you can give, to yourself and others. The benefits of gratitude have long been championed in religious and philosophical thinking. In recent years, the science has been catching up: it shows that people who feel most grateful generally get a psychological boost as a result. They also have greater life satisfaction, fewer visits to the doctor and better sleep. This has led to gratitude becoming part of our cultural zeitgeist, inspiring a proliferation of gratitude journals, in which you record things you are thankful for, and meditation practices in which you focus thoughts on them. It has also led to renewed interest in the neuroscience and psychology of gratitude (see “The grateful brain”). However, the benefits of actually expressing this gratitude have received less attention. Now evidence is stacking up that shows turning our inner gratitude into action can make our lives even better.
12-18-18 How busting some moves on the dance floor is good for your brain
Whether you do the robot, shake your tail feather or go full ballroom, dancing has benefits that go way beyond having a good time. NOT all of us have what it takes to be a dancing queen. But whether you are a politician with two left feet or a Strictly Come Dancing wannabe, if you like to dance you are in luck. Ballet, ballroom or breakdancing, it doesn’t matter: getting into the groove does wonders for you. And it’s not just the joy of moving to music. Dancing is good for the brain too. It can change the way you think and even keep your mind sharp as you age. “People are born to move. They are born to move rhythmically,” says dance psychologist Peter Lovatt at the University of Hertfordshire, UK. Admittedly, we are not all blessed with the same degree of talent for it, but dancing is ingrained in human nature. People across almost all cultures have done it for as long as we know. Indeed, a sense of rhythm seems to be innate. Telltale brain activity in newborn babies reveals that even they can spot when a drummer skips a beat. Humans are not the only species with rhythm. The list is not long, but other groovers include elephants, sea lions and bonobos. One thing most of them have in common is a complex social life, leading to the idea that a sense of rhythm might have evolved as part of a group’s need to coordinate its actions. Indeed, studies reveal that when people move in synchrony they experience a stronger sense of community and are more altruistic towards one another. Likewise, children who dance together turn out to be more cooperative in subsequent games. What’s more, when professional dancers watch clips of dancing their brainwaves begin to synchronise. “Moving together in rhythm supports social bonding,” says Lovatt. “It increases prosocial behaviour.”
12-18-18 Why do wombats poo cubes and turkeys spirals? One woman is finding out
Engineer Patricia Yang won an IgNobel prize for flushing out a universal law of animal urination. Next up? Discovering why wombat stools come out as cubes. FOR Patricia Yang, bodies are a series of tubes fine-tuned to pump the gory and the gross: blood, urine and faeces. A mechanical engineer at the Georgia Institute of Technology, she studies the fluid dynamics of what goes round inside living bodies, and what comes out of them. She has won an Ig Nobel prize, which celebrates unusual science that makes people laugh, and it is well deserved. Yang does the dirty work of handling faeces-filled wombat intestines, gathering pig’s blood from slaughterhouses and designing makeshift elephant urethras – all for the sake of science. And she can’t get enough of it. I’m an engineer. I study blood, I study pee and I study poop. When I tell people that, they have a hard time linking engineering with biology, but I don’t see a distinction between the two. Animals use engineering to survive. Body fluids work for us, carrying nutrition or waste or oxygen. These fluids have a purpose, and I want to know how they work. I’ve liked animals since I was really young. When I started my PhD, my adviser was potty training his kid and had been doing a lot of waiting around for his son to pee. He had to do the same thing with his dog. He wanted to know what urination was like at the extremes – for the smallest animals and the largest. He asked me how long it would take for an elephant to pee. I said, “I’ll study anything as long as I can spend time at the zoo.”
12-18-18 The mysterious demise of Europe’s massive cave bears
Once more common than brown bears, cave bears didn't survive the last ice age. Could their sad end be down to their diet, or just to being bears of very little brain? IF YOU go down underground today, look out for a big surprise. If you go into a cave, anyway, be sure to adjust your eyes. For many caves, in Europe at least, contain the remains of a curious beast. It’s not an olm or a bat that’s deceased – it’s a cave bear. Cave bears died out at least 24,000 years ago, but they were once very common. In fact, they left so many bones that during the first world war, they were used to provide phosphates for fertilisers and bombs. Plenty of skulls and skeletons still remain in caves across a swathe of Eurasia, from Spain to south-central Russia, and this treasure trove has allowed palaeontologists to piece together the bear’s story. We know, for example, that males could reach a whopping 1000 kilograms – up to four times the weight of females. Footprints, claw marks and fur imprints reveal that, in winter, some settled on terraces and entered a deep sleep known as torpor, waking periodically to drink from water sources inside their caves before returning to their resting places. We even know that Neanderthals hunted cave bears, ambushing them as they awoke in the spring. But one mystery remains. Why did they go extinct? Cave bears evolved around 1.5 million years ago from a common ancestor with brown bears and polar bears – in fact, their DNA lives on in modern brown bears, revealing that the two species must have interbred. They lived during the Pleistocene, a time when Earth’s climate endured a series of fluctuations, including relatively rapid changes – within 1000 years – from hot and dry to cold and wet. One such ice age occurred around the time cave bears died out. Could this have played a role in their demise? Danielle Schreve at Royal Holloway, University of London, notes that it would have put significant ecological stress on large animals. Nevertheless, some of the bear’s competitors – including brown bears, wolves and lions – managed to survive, hinting that they possessed something cave bears lacked.
12-17-18 Stem cells implanted into the brain stop epilepsy seizures in rats
For people with severe epilepsy, no medication is effective – but a radical approach of implanting stem cells into the brain could stop seizures at their source. The technique, which has so far shown promise in rats, would involve taking some of a patient’s own skin cells and turning them into embryonic-like stem cells in the lab. These can then be directed to become a kind of brain cell that damps down seizures. Epilepsy arises when there is an imbalance between two different kinds of nerve cell in the brain; excitatory ones, which cause other cells to fire, and inhibitory ones, which block firing. Seizures result when excitation swamps inhibition. For some people with epilepsy, the surge of excitation starts in one part of the brain, called the hippocampus, before spreading elsewhere. So Ashok Shetty at Texas A&M University and his colleagues tried boosting inhibition at that site to see what would happen. First, Shetty’s team injected 38 rats with a chemical that triggers a long seizure. The resulting brain damage causes the animals to have spontaneous seizures, starting from the hippocampus, over the next few months. A week after the initial damage, the team implanted inhibitory brain cells in the hippocampi of about half the rats. Five months later, those given implanted cells had 70 per cent fewer seizures than those without implants. To check it was really the inhibitory cells working, five implanted animals were given cells that were genetically modified to stop firing when the animal was dosed with a drug. When under the drug’s influence, these mice had about the same number of seizures as mice that hadn’t had any cells implanted. Dissections also showed that the implanted cells survived in the hippocampus.
12-17-18 Tumor ‘organoids’ may speed cancer treatment
A new method can quickly test hundreds of drugs on mini tumors grown from patients’ own cells. Collecting cancer cells from patients and growing them into 3-D mini tumors could make it possible to quickly screen large numbers of potential drugs for ultra-rare cancers. Preliminary success with a new high-speed, high-volume approach is already guiding treatment decisions for some patients with recurring hard-to-treat cancers. “Believe it or not, for some rare cancers there is no standard of care,” UCLA cancer biologist Alice Soragni said December 12 at a joint meeting of the American Society for Cell Biology and the European Molecular Biology Organization. “What if we could go back and tell the doctor, ‘Hey this combination of therapies worked really well for this specific patient?’” In one case, Soragni and her colleagues tested 430 compounds on mini tumors grown from cells from a boy with a rare bone cancer. Eight of the compounds caused 75 percent cell death in the mini tumors — and those included cancer drugs not typically considered for his type of cancer, the team reported at the meeting. While the boy is still responding well to standard chemotherapy, the approach could point to new treatments for patients running out of options. “If a candidate drug shows exciting activity and is [U.S. Food and Drug Administration] approved, then we would absolutely consider it,” says Noah Federman, who directs UCLA’s Pediatric Bone and Soft Tissue Sarcoma Program.
12-17-18 News of the first gene-edited babies ignited a firestorm
Chinese researchers used CRISPR/Cas9 to alter a gene to block HIV infection. A Chinese scientist surprised the world in late November by claiming he had created the first gene-edited babies, who at the time of the announcement were a few weeks old. Scientists and ethicists quickly responded with outrage. In an interview with the Associated Press and in a video posted November 25, Jiankui He announced that twin girls with a gene altered to reduce the risk of contracting HIV “came crying into this world as healthy as any other babies.” Many researchers and ethicists say implanting gene-edited embryos to create babies is premature and exposes the children to unnecessary health risks. Critics also fear the creation of “designer babies,” children edited to enhance their intelligence, athleticism or other traits. Facing his peers on November 28 in Hong Kong at the second International Summit on Human Genome Editing, He explained his research. He also revealed that another woman participating in a gene-editing trial is in the early stages of pregnancy (SN Online: 11/28/18). He said his group used the gene-editing tool CRISPR/Cas9 to disable the CCR5 gene in the fertilized eggs that produced the babies, “Lulu” and “Nana” (not their real names). CCR5 encodes a protein that allows the most common version of the HIV virus to enter cells. Some people naturally have versions of the gene that help protect against HIV infection. The girls’ parents were one of seven couples recruited from an HIV patient group to take part in what was called an HIV vaccine development project. The twins’ father has HIV; their mother does not.
12-17-18 Crime solvers embraced genetic genealogy
The Golden State killer case was just the beginning. Every week, Ellen Greytak checks DNA profiles in a genealogy database. She’s not searching for long-lost relatives. She’s out to find family members of unknown assailants in rape and murder cases. Greytak is director of bioinformatics at Parabon NanoLabs in Reston, Va. Since May, the company has used genetic genealogy, a forensic technique for tracking down suspects through their family trees, to help close more than a dozen cases nationwide. In 2018, criminal investigators in the United States embraced the tool, solving decades-old cold cases and some fresh crimes. But this new type of DNA-based detective work has raised questions about genetic privacy and police procedures. More than 12 million Americans have jumped on the consumer genetic testing bandwagon, sending spit samples to companies like 23andMe or AncestryDNA to learn about health risks and to explore family origins (SN: 6/23/18, p. 26). People who’ve had their DNA tested and want to find relatives tested by a different company can upload their results to a public database called GEDMatch. Now GEDMatch is being used to locate rape and murder suspects. In April, Sacramento police arrested Joseph James DeAngelo as a suspect in the Golden State Killer case (SN Online: 4/29/18). DeAngelo, a former police officer, is accused of committing about 50 rapes and 12 murders from 1974 to 1986.
12-17-18 Drinking studies muddied the waters around the safety of alcohol use
Meta-analyses advocate consuming little to no alcohol. For people who enjoy an occasional cocktail, 2018 was a sobering year. Headlines delivered the news with stone-cold certainty: Alcohol — in any amount — is bad for your health. “The safest level of drinking is none,” a group of scientists concluded. That finding, along with another one reported this year, seemed to contradict the reassuring notion that an occasional drink might be good for you (SN: 9/5/15, p. 10). But the two studies were met with a flurry of criticism. While drinking in excess is undoubtedly unhealthy, a finding confirmed by this year’s research, the studies and the headlines focused on the risks of a single drink per day. And that’s a risk the analyses weren’t designed to address. “These studies clearly show that alcohol is a huge health problem,” says Stanford University epidemiologist John Ioannidis, who was not involved in the studies. “But the emphasis was placed on no amount of alcohol being safe, and that’s wrong.” Both studies were meta-analyses. They combined data from numerous observational studies that tracked what large numbers of people drank over time and compared rates of disease or death in those populations. For the first study, a team from the University of Cambridge combined 83 studies that looked for links between drinking and the risk of death or cardiovascular disease in nearly 600,000 people in 19 countries. People who had more than about seven drinks per week (one drink is 12 ounces of beer, five ounces of wine or 1.5 ounces of distilled spirits) had a lower life expectancy and a higher risk of stroke, heart failure, fatal aneurysm and other problems than lighter drinkers. The more booze imbibed, the greater the risk of earlier death, the team reported in the April 14 Lancet.
12-17-18 Zapping the spinal cord helped paralyzed people learn to move again
Combination of electricity and intense rehab helped patients who had been immobile for years. The spinal cord can make a comeback. Intensive rehabilitation paired with electric stimulation of the spinal cord allowed six paralyzed people to walk or take steps years after their injuries, three small studies published this year showed. “There’s a capacity here of human spinal circuitry to be able to regain significant motor control and function,” says Susan Harkema, a neuroengineer at the University of Louisville in Kentucky who led one of the studies, published in September in the New England Journal of Medicine. “That’s really exciting and really important.” Nearly 1.5 million people in the United States have some degree of paralysis from a spinal cord injury. For many of these people, rehabilitation focuses on learning to live with their newly limited mobility. In all three studies, patients were implanted with a small device that zaps the spinal cord. Over months of training sessions, the stimulators sent electrical signals to the patients’ spinal cord. At the same time, researchers guided the participants through physical therapy routines. Eventually, some patients could take a few steps with no support, though most needed crutches, walkers or aid from harnesses that held them up.
12-17-18 Human smarts got a surprisingly early start
Our ancestors’ ingenuity enabled long-distance treks and artistic endeavors. Archaeological discoveries reported this year broadened the scope of what scientists know about Stone Age ingenuity. These finds move the roots of innovative behavior ever closer to the origins of the human genus, Homo. Example No. 1 came from Kenya’s Olorgesailie Basin, where fickle rainfall apparently led to a wave of ancient tool and trading advances (SN: 4/14/18, p. 8). Frequent climate swings in East Africa probably stimulated the creation of new types of stone tools and the formation of trading networks by about 320,000 years ago, said a team led by paleoanthropologist Rick Potts of the Smithsonian Institution in Washington, D.C. Soil analyses point to shifts from dry to rainy conditions every few years or Potts has argued since the 1990s that humans and our direct ancestors evolved to deal with frequent environmental shifts, making human evolution a story of “survival of the versatile.” That’s still a controversial idea, but the Olorgesailie finds support Potts’ scenario. No Homo fossils have been found at the Kenyan location, leaving the toolmakers’ evolutionary ID unknown. But the timing is right for the Olorgesailie folk to have been Homo sapiens (SN: 12/23/17, p. 24). If they were, Olorgesailie groups heralded later Stone Age artistic innovations by humans elsewhere. A crosshatched design on a rock found in South Africa was made by humans around 73,000 years ago, making it the oldest known drawing, another team reported this year (SN: 10/13/18, p. 6).
12-17-18 Our primate ancestors may have originated in Europe or North America
Our distant primate ancestors are thought to have arisen in Asia, but new evidence challenges this assumption, suggesting primates may instead have evolved in Europe or North America. Primates include all lemurs, monkeys, apes and humans. The oldest confirmed primate fossils are about 56 million years old, so were formed 10 million years after the extinction that wiped out all dinosaurs except birds. This time is called the Palaeocene-Eocene Thermal Maximum because the average global temperature rose by 5°C or more in a few thousand years. Many ocean species died out, but life on land flourished. Primates emerged, as did the first hoofed mammals. The established story has been that primates appeared at this time in Asia, says anthropologist Paul Morse. This is based on the discovery in China of several fossils of primitive primates that resemble miniature monkeys or bushbabies. These include Archicebus achilles as well as Teilhardina asiatica, which is thought to be one of the earliest primates. But other Teilhardina species have been found elsewhere, and seem to be just as old. These include Teilhardina belgica in Europe and Teilhardina brandti and several other species in North America. To better understand early primates, Morse – while working at the Florida Museum of Natural History – and his colleagues collected 163 new T. brandti fossils from the Bighorn Basin in Wyoming, and compared them with other Teilhardina species (Journal of Human Evolution, doi.?org/cxx9). “What we found, once we had evaluated the variation within T. brandti, was that it closely resembled the animal from China [T. asiatica],” he says. “T. belgica also has some of these characteristics. They’re all about on par with one another in their primitiveness.” That means T. asiatica cannot be reliably distinguished from either Europe’s T. belgica or North America’s T. brandti. If we can’t determine which fossil is the most primitive, we also can’t tell where primates evolved. Morse emphasises that he isn’t claiming North America is their cradle, rather than Asia, but that the question remains open.
12-17-18 Stunning fossils show pterosaurs had primitive feathers like dinosaurs
Two spectacular fossils found in China show that the flying reptiles known as pterosaurs had primitive feathers to help keep them warm, just like many dinosaurs. The finding suggests that feathers evolved far earlier than we thought. The wings of pterosaurs were made of skin, muscles and fibre, so they had no need of flight feathers. The feathers they had are small and tufty. “They are almost certainly just for insulation,” says Mike Benton at the University of Bristol, UK, a member of the team that discovered one of the fossils about two years ago. The second specimen was found several years ago but its importance is only now being appreciated. Fossils found as long ago as the 1840s revealed that pterosaurs had fur on their head and bodies. Palaeontologists came up with the term “pycnofibres” to describe it, to distinguish it from the hair of mammals and the feathers of birds. In the recently discovered fossils, these pycnofibres are exceptionally well preserved. Much of the head, body and limbs of these pterosaurs were covered by hair-like filaments, just we have long thought was the case. But the team also found three distinct types of branched filaments. “If your dermal fluff branches, that’s a feather,” says Benton. One type, found on the neck, branches at the end in a brush-like manner. The second type, found on the head, has side branches. And the third, found on the wing membranes, branches from the base and resembles down. They are remarkably similar to the feathers found on many dinosaurs. “If all I had was a photo of the fluffy stuff on these fossils, and I didn’t know they were attached to a pterosaur, I would probably think they were the feathers of a feathered raptor dinosaur,” says palaeontologist Steve Brusatte of the University of Edinburgh in the UK, who wasn’t involved in the study. “I think it’s now case closed, pterosaurs had feathers.”
12-17-18 Pterosaurs: Fur flies over feathery fossils
Two exceptionally well preserved fossils give a new picture of the pterosaurs, the flying reptiles that lived at the time of the dinosaurs. Scientists believe the creatures may have had feathers, and looked something like brown bats with fuzzy wings. The surprise discovery suggests feathers evolved not in birds, nor dinosaurs, but in more distant times. Pterosaurs were the closest relatives of dinosaurs, sharing a common ancestor about 250 million years ago. "We would suggest - tentatively - that it would be worth considering that feathers originated much earlier than we thought," Prof Mike Benton, from the University of Bristol, told BBC News. Hailing from China, the 160-million-year-old fossils are of two different pterosaurs, one of which is newly discovered. In depth analysis shows that as well as fur - which has been suggested before - the flying reptiles had feathers like some dinosaurs, including the theropods. "If I just saw these fluffy bits on their own, I would swear they were from a theropod dinosaur," said Dr Steve Brusatte of the University of Edinburgh, who was not part of the study. "This means feathers were not a bird innovation, not even a dinosaur innovation, but evolved first in a much more distant ancestor. "The age of dinosaurs was full of all sorts of strange feathery creatures!" The researchers found that the pterosaurs had four different kinds of covering, including fuzzy, fur over most of their body; and, on parts of the head and wings, three types of fibres similar to modern feathers. The fluff and feathers are likely to have been important in heat regulation and aerodynamics. "These structures on the pterosaur make it look a bit like a fruit bat, or something like that, a fuzzy hairy creature," said Prof Benton, who worked on the discovery with colleagues in China. "They fly with great out-stretched bony wings that carry a substantial membrane, a bit like a bat."
12-17-18 Hastings dinosaur footprints exposed by cliff erosion
Dozens of well-preserved dinosaur footprints from at least 100 million years ago have been uncovered in East Sussex. At least seven different species were identified by University of Cambridge researchers during the past four winters following coastal erosion along the cliffs near Hastings. They range in size from less than 2cm to more than 60cm across, and are so well-preserved that even the skin, scales and claws are easily visible. There are more than 85 markings, all of which date from the early Cretaceous period. The species include Iguanodon and Ankylosaurus, a type of stegosaurus, possible examples from the sauropod group, and meat-eating theropods. Hastings has long been a site of special interest for fossil hunters with items ranging from fragments of dinosaur bones to complete fish being previously uncovered, but footprints are less common. The footprints are the first to have been discovered in 25 years, with earlier findings being far less varied and detailed. The results are reported in the journal Palaeogeography, Palaeoclimatology, Palaeoecology, authored by Anthony Shillito and Dr Neil Davies. "Whole body fossils of dinosaurs are incredibly rare. "A collection of footprints like this helps you fill in some of the gaps and infer things about which dinosaurs were living in the same place at the same time," Mr Shillito said. He added that the "incredible detail" clearly showed "the texture of the skin and scales, as well as four-toed claw marks". The area where the footprints were found was likely near a water source, and in addition to the footprints, a number of fossilised plants and invertebrates were also found.
12-16-18 Sometimes a failure to replicate a study isn’t a failure at all
A recent study on ego depletion can’t confirm an old one. Who is right? Probably everyone. As anyone who has ever tried a diet knows, exerting willpower can be exhausting. After a whole day spent carefully avoiding the snack machine and attempting to take mindful joy in plain baked chicken and celery sticks, the siren call of cookies after dinner may be just too much to bear. This idea — that exercising self-control gets harder the more you have to do it — is called ego depletion, and it’s one of the most well-known concepts in social psychology. There are popular books on it. Most of us have probably have personal experience with it. But what if a huge study of thousands of people found no evidence for ego depletion? What if some cultures actually show reverse ego depletion — where exerting willpower actually makes exerting more willpower easier? What if I told you that ego depletion does exist — but only if you believe it does? Do these recent studies mean that one of the most well-established phenomena in social psychology is headed for the dusty shelf of discredited theories? Does it mean that everything you thought you knew about willpower was wrong? Not at all. Ego depletion may still exist. It just may be limited to particular contexts and conditions, such as an ill-fated attempt at a crash diet. Social psychology is not trying to troll you. But it does have to contend with a giant source of variability that other fields don’t. Gravity exists whether or not it had a happy childhood. An element has specific properties, and those properties don’t change because the element in question had a bad day.
12-15-18 The great electromagnetic resistance
Electromagnetic hypersensitivity isn't recognized as a medical disorder, but many insist their symptoms are indicative of the way technology is harming all of us. ne fall day in the early 1990s, in the basement of an old Staten Island home, 8-year-old Ashley Portman was electrocuted. A combination of factors were to blame: the faulty wiring of an old house, the curiosity of a child left to her own devices, the intrigue of endless rooms, and the lure of unfamiliar odds and ends belonging to a distant family friend. Portman had gone exploring. In the basement, she found a treadmill, and for fun, she began to walk in step. The machine faced a high bar top, upon which a small television set was perched. When she turned the knob, the screen filled with the gray fuzz of television snow, so she reached to adjust the metal rabbit ears. She managed to scream before her body went as rigid as a pole. Her hands burned, and she could not release her grasp on the antennae. Decades later, the memory of the electrocution is like swimming through a dream. It remains unlike anything she's ever felt — "an indescribable, invasive pain." Portman suspects she would have died, if not for some inexplicable force — "a higher power" — that intervened, knocking the television set from the bar top. As the television fell, the plug was pulled from the socket, and the electrical connection cut. She collapsed onto the floor. For hours that night, as she lay in a guest bed on the top floor of the house, she says she felt waves of electrical energy starting at the top of her head and running down through her legs. Two and a half decades later, she believes that her childhood electrocution caused a condition that plagues her to this day. Portman's collaborator today is Elizabeth Kelley, who has been on a two-decade mission to build awareness of issues surrounding the wireless technology revolution — and to "get the facts" about the health, environmental, and constitutional consequences of the multibillion-dollar telecom industry. A former federal government public policy analyst, Kelley is now the executive director of the nonprofit Electromagnetic Safety Alliance and manages an international appeal brought by 244 scientists from 41 countries "urgently calling" for the international community to "address the global public health concerns related to exposure to cellphones, power lines, electrical appliances, wireless devices, wireless utility meters, and wireless infrastructure."
12-14-18 Cloning monkeys
More than 20 years after researchers cloned Dolly the sheep, scientists in China cloned two monkeys—the first time the technique had been used on primates. The researchers transferred DNA taken from fetal monkey cells into eggs that had had their own DNA removed, stimulated the eggs to develop into embryos, and implanted them in female surrogates. The process yielded female identical-twin long-tailed macaques. Producing large groups of genetically identical monkeys could revolutionize research on disease. But some experts fear the technique could be used for humans—concerns the Chinese researchers dismissed. “We’re not going to do it,” said Mu-ming Poo.
12-14-18 Organic foods may reduce cancer risk
Organic foods may reduce cancer risk. For almost five years, researchers in France regularly asked nearly 70,000 volunteers how often they ate organic fruit, vegetables, meat, and other products. During that period, the quarter of participants who ate the most organic foods were 25 percent less likely to get cancer than the quarter who ate the least, even after accounting for age, income, and other risk factors. Lead author Julia Baudry suspects the disparity is because organic foods have lower levels of pesticides, which can mimic hormones in the body and increase cancer risk. Promoting organic food consumption, she says, could be a “promising preventive strategy against cancer.”
12-14-18 Holding hands can reduce physical pain
Holding hands can reduce physical pain. In a University of Colorado Boulder study, 22 women were subjected to mild pain; first when their male partner was holding their hand, and then when he was not. The women reported that holding hands reduced the intensity of their pain by an average of 34 percent. Brain scans taken during the experiment showed that when the couple linked hands, their brain waves became synchronized—and that this “coupling” effect was even greater when the women were in pain. Lead author Pavel Goldstein says the research “illustrates the power and importance of human touch.”
12-14-18 Saunas could be as beneficial for your heart
Saunas could be as beneficial for your heart as moderate exercise. In a study in Finland, 102 middle-aged adults with at least one heart disease risk factor—such as high blood pressure or obesity—had a 30-minute sauna session. Afterward, their blood pressure was lower, their heart rate was higher, and their arteries had gained elasticity. Heat exposure can widen blood vessels and improve blood flow, and sweating has a natural diuretic effect, lowering blood pressure. “Sauna use is recommended,” says co-author Tanjaniina Laukkanen, “and it seems that more is beneficial.”
12-14-18 Full-fat dairy may help protect against heart disease and stroke
Full-fat dairy may help protect against heart disease and stroke. Researchers examined data from more than 130,000 people across 21 countries over nine years. Participants who ate two or more daily servings of full-fat dairy—a serving was 8 ounces of milk or yogurt or a half-ounce of cheese—had a 22 percent lower risk of heart disease, a 34 percent lower risk of stroke, and a 23 percent lower risk of dying from cardiovascular disease. Study author Mahshid Dehghan says that while full-fat dairy is high in saturated fat, it contains other important nutrients, including calcium and vitamin K.
12-14-18 To-do lists could help you sleep
To-do lists could help you sleep. A Baylor University study divided nearly 60 volunteers into two groups before a strictly enforced bedtime: half were asked to write a list of things they needed to do over the next few days, and the other half listed tasks they’d already completed. Brain scans taken as they slept found that the to-do-list writers dozed off nine minutes faster on average—an effect similar to that of some pharmaceutical sleeping aids. “Throughout the day, we have all these things cycling through our head,” says lead author Michael Scullin. Writing “helps us hit the Pause button.”
12-14-18 Leg exercises appear to be crucial for brain health
Leg exercises appear to be crucial for brain health. Researchers immobilized the hind legs of mice for 28 days, then examined the subventricular zone in their brains, where neural stem cells produce new neurons. They found that the number of neural stem cells—which help the brain renew itself—had plummeted by 70 percent. Declines in oxygen levels associated with reduced physical activity had also altered the rodents’ metabolism. The research suggests that leg movement sends signals to the brain that trigger new cell growth.
12-14-18 Turmeric could help improve memory
Turmeric could help improve memory and ease depression among those with age-related mental decline. Researchers recruited 40 volunteers, ages 50 to 90, all with memory complaints but none with dementia. Half took curcumin, an active compound of the Indian spice turmeric, twice a day for 18 months, while the other half received a placebo. Those taking curcumin saw a 28 percent improvement in memory function, chalked up better mood scores, and had less plaque buildup in the brain. Study leader Gary Small says curcumin may reduce brain inflammation, which has been linked to Alzheimer’s and depression.
12-14-18 Breathing in moon dust could release toxins in astronauts’ lungs
The surface of the moon is dusty – and nasty. The Apollo astronauts quickly learned that the sharp grains of moon dust could tear spacesuits and irritate their lungs, but now it seems the lunar surface is even worse for human health than we thought. By studying lunar dust samples brought back by astronauts, we discovered that they contain certain minerals that are known to quickly react with human cells and generate toxic hydroxyl radicals. These hydroxyl radicals have previously been linked to lung cancers. To estimate how many radicals would be produced in humans after exposure to lunar dust, Donald Hendrix at Stony Brook University and his colleagues soaked olivine and augite, two iron-based compounds found on the moon, in a liquid that simulates human lung fluid. After 15 minutes the two rocks had released about nine times more hydroxyl radicals per litre of fluid than quartz, a highly toxic, silicon-based compound. “The fine metallic iron is extremely hazardous to human health,” says Hendrix. He suggests these minerals can easily enter human system and produce large quantities of radicals. Because of the limited supply of lunar dust, the study used similar rocks found on Earth, which contain less reactive minerals, he says. So, the damage from real lunar dust may be more severe. (Webmaster's comment: Another good reason not to live there!)
12-13-18 Big data reveals hints of how, when and where mental disorders start
New genetic complexities emerge for schizophrenia, bipolar disorder and autism. Psychiatric disorders’ many complexities have stymied scientists looking for clear genetic culprits. But a new giant dataset holds clues to how, when and where these brain disorders begin. Called PsychENCODE, the project’s first large data release has revealed intricate insights into the behavior of genes and the stretches of genetic material between them in both healthy brains and those from people with schizophrenia, bipolar disorder or autism spectrum disorder. The results, split among 10 studies published online December 13 in Science, Science Advances and Science Translational Medicine, offer some of the most detailed looks yet at the links between these genetic elements and brain health. “It’s all connected, and now we have the tools to unravel those connections,” says geneticist Thomas Lehner of the National Institute of Mental Health in Bethesda, Md., who oversaw the project but wasn’t involved in the research. Earlier studies have pinpointed certain genes and other stretches of the genome — the genetic material that makes up cells’ instruction books — as being involved in schizophrenia, bipolar disorder and autism spectrum disorder. The new collection of work goes further, both confirming and clarifying some of these roles.
12-13-18 Corn domestication took some unexpected twists and turns
Farmers in Mexico and South American tamed maize over thousands of years, a DNA study finds. Corn eaten around the world today originated via a surprisingly long and complex process that started in what’s now southern Mexico around 9,000 years ago, a new study finds. People brought a forerunner of present-day corn plants, also known as maize, to South America from Mexico more than 6,500 years ago. Those plants still contained many genes from maize’s wild ancestor, teosinte, say archaeologist and evolutionary ecologist Logan Kistler of the Smithsonian Institution in Washington, D.C., and his colleagues. Farmers in Mexico and the southwestern Amazon, in parts of what’s now Bolivia and Brazil, continued to tame the partly domesticated plant over several thousand years, the international team reports in the Dec. 14 Science. These results, based on a reconstruction of maize’s genetic history, challenge a longstanding idea that farmers in southern Mexico molded teosinte into fully domesticated maize relatively quickly around 9,000 years ago before the crop spread elsewhere. “We’ve shown that parts of the process were taking place thousands of kilometers [from Mexico] and thousands of years after the whole thing started,” Kistler said in a December 11 news conference.
12-13-18 Childhood hormone treatments may have spread Alzheimer’s proteins
Growth hormones given to children decades ago appear to have spread proteins linked to Alzheimer’s disease. The finding adds to evidence that Alzheimer’s proteins can be transmitted between people. Between 1958 and 1985, approximately 30,000 children around the world received injections of human growth hormone extracted from dead bodies to treat genetic disorders and growth deficiencies. Three years ago, while examining the brains of eight people who had received such injections and later died of the rare brain disorder Creutzfeld-Jakob disease (CJD), John Collinge at University College London and his colleagues noticed they all had beta-amyloid proteins in their brains. Beta-amyloid is known to accumulate and form sticky plaques in the brains of people with Alzheimer’s disease. These eight people didn’t have this condition, as they all died from CJD at a young age, but Collinge says that had they lived, it’s possible that they would have gone on to develop it. “That led us to hypothesise that the reason they got this [amyloid] is because those growth hormone batches that were prepared many years ago with human tissue were contaminated with this protein,” says Collinge. Before synthetic alternatives were available, human growth hormone was extracted from the pituitary glands of cadavers. “Another suggestion was maybe it’s the growth hormone itself that stimulates the amyloid beta pathology, and not any contaminant,” he says. To investigate, Collinge and his team used samples of the human growth hormone that were given to these eight people, which had been archived by a health body in the UK.
12-13-18 Here’s a rare way that an Alzheimer’s protein can spread
When injected, amyloid-beta from vials of growth hormone built up in mice brains. An Alzheimer’s protein found in contaminated vials of human growth hormone can spread in the brains of mice. That finding, published online December 13 in Nature, adds heft to the idea that, in very rare cases, amyloid-beta can travel from one person’s brain to another’s. Decades ago, over a thousand young people in the United Kingdom received injections of growth hormone derived from cadavers’ brains as treatment for growth deficiencies. Four of these people died with unusually high levels of A-beta in their brains, a sign of Alzheimer’s disease (SN: 10/17/15, p. 12). The results hinted that A-beta may have been delivered along with the growth hormone. Now researchers have confirmed not only that A-beta was in some of those old vials, but also that it can spark A-beta accumulation in mice’s brains. Neurologist John Collinge of University College London and colleagues found that brain injections of the contaminated growth hormone led to clumps of A-beta in the brains of mice genetically engineered to produce the protein, while brain injections with synthetic growth hormone did not. Amyloid-beta (brown) accumulated inside brain blood vessels (No. 1) and formed plaques in the cerebellum (No. 2) in the brains of mice injected with growth hormone that came from cadavers. The results suggest that A-beta can “seed” the protein in people’s brains, under the right circumstances. Still, that doesn’t mean that Alzheimer’s disease is transmissible in day-to-day life.
12-13-18 We’ve been using CRISPR for years – now we know how it really works
A storm of criticism met the claimed creation of the first genome-edited children in China last month. One reason is that the twin girls have unpredicted new mutations whose effects are unknown. But it now appears there’s a really easy way to ensure the CRISPR genome editing technique makes far more precise, predictable mutations. DThe term “CRISPR genome editing” is really a bit of a misnomer. The method is most commonly used to disable genes by cutting the DNA in a specific site. When the cell repairs the cut, it typically adds or removes one or more DNA letters. But Paola Scaffidi of the Francis Crick Institute in London suspected that these mutations might not be as random as they appear. To find out, her team induced mutations in 1500 target sites in human cells growing in a dish. They found a stunningly simple pattern. “We started with machine learning but we did not need it,” Scaffidi says. It appears the sequence of the RNA that guides the CRISPR Cas9 protein to its target is crucial. If the fourth DNA letter from the end is a G, the resulting mutation is indeed relatively random. But if it’s an A, T or C the outcome is more predictable. If it’s a T, for instance, in 9 out of 10 cells a single extra T will be inserted at the target site. If the findings are confirmed, it means the thousands of biologists around the world using CRISPR for research can make it far more precise and powerful simply by altering the guide RNAs they use. It also greatly boosts the prospects for using CRISPR to treat all kinds of disorders by correcting disease-causing mutations inside the body.
12-13-18 Some people have slightly squashed heads thanks to Neanderthal DNA
People with two Neanderthal genes have heads that are flatter on top and more elongated – like those of Neanderthals themselves. The effect is too small to be seen with the naked eye, but shows up on brain scans. The modern versions of the genes seem to make certain parts of the brain work more effectively. Neanderthals were not the direct ancestors of our own species, but our distant cousins. They were already living in Europe by the time our ancestors arrived, about 40,000 years ago, and there seems to have been interbreeding, as most Europeans have some Neanderthal genes lurking in their DNA – between 1 and 2 per cent of the total. Simon Fisher of the Max Planck Institute for Psycholinguistics in the Netherlands wondered if these genes would have any effect on head shape, as both Neanderthal skulls – and those of our last common ancestors with Neanderthals – are less ball-shaped than the skulls of people living today. “It’s one of the most distinctive anatomical differences,” says Fisher.
12-13-18 50 years ago, armadillos hinted that DNA wasn’t destiny
Excerpt from the November 30, 1968, issue of Science News. Armadillos come in fours, quadruplet offspring from a single egg, and are endowed with identical genes. Yet, the quadruplets are often not identical, a fact that calls into question the assumption that genes encased in the nucleus of the cell are the sole determinants of heredity. — Science News, November 30, 1968. What comes naturally to the nine-banded armadillo, the species that baffled scientists 50 years ago, is rare in other mammals. Polyembryony, producing many offspring from a single fertilized egg, does result in genetically identical armadillo pups. But scientists now know that other factors also stir the developmental pot. For example, epigenetic marks, the chemical tags that control a gene’s activity level, can make identicals look very different. Though genetically fascinating, armadillos never topped rodents as research subjects?—?possibly due to their fresh insect diet and long time between litters. Scientists do use the tanklike creatures to study leprosy, a disease the animals can pick up and pass on to humans (SN: 5/21/11, p. 9).
12-13-18 Bizarre fossil that baffled us for years is early starfish ancestor
A mysterious group of ancient animals may have been the ancestors of starfish, according to a study of newly discovered fossils. “It’s the first time that soft parts have been found in this group of fossils,” says Bertrand Lefebvre of Claude Bernard University Lyon 1 in France. “It was the only clue to put an end to a very old debate.” Stylophorans are a group of early complex animals. They appeared in the Cambrian period, which began 541 million years and saw the first explosive flowering of animal diversity, and disappeared during the Carboniferous, which ended 299 million years ago. Each fossil looks a little like an arrow, if the arrowhead was disproportionately large compared to the shaft. They do not fit neatly into any existing group of animals, so the question has been where they fit into the tree of life. One interpretation is that the “shaft” is a tail, in which case they looked a bit like tadpoles. That would suggest they were closely related to backboned animals like fish and humans. This idea has been defended for many years by the British palaeontologist Richard Jefferies. However, the fossils also look a bit like echinoderms, the group that includes starfish. In that interpretation, the shaft is not a tail but a feeding arm. The difficulty with this is that stylophorans only had one arm, whereas starfish typically have five. Some have also argued that they were hemichordates, a group of worm-like creatures closely related to echinoderms.
12-12-18 First direct evidence that later school day really does help teenagers
Pushing back high school start times not only improves the quality of students’ sleep, it also boosts attendance and academic performance, according to a study of US school attenders. The study is the first to show this objectively – using wrist-worn activity monitors to measure sleep duration – rather than by relying on self-reported information on sleeping habits. Teenagers naturally prefer late nights and lie-ins due to body clock shifts that occur during puberty. However, this preference does not align with the early start times of most schools. “You’re basically chopping off the last chunk of sleep they need,” says Horacio de la Iglesia at the University of Washington. To address this problem, schools in Seattle decided to delay their start time from 7:50 to 8:45am from mid-2016 onwards. De la Iglesia and his colleagues decided to measure the impact by studying students before and after the change. To make the comparison as objective as possible they compared students taking a tenth-grade biology class in 2016 with their younger peers taking the same class in 2017. There were 94 students in the 2016 group and 84 in the 2017 group. According to activity monitors worn on their wrists, the students in 2016 and 2017 went to bed at around the same time. But because they were able to sleep in later, the 2017 students snoozed for an extra 34 minutes per day on average. This extra sleep was correlated with greater daytime alertness and 5 per cent higher second-semester grades on average. This may be because sleep plays a key role in learning and laying down memories, says de la Iglesia. At one of the schools, class attendance also improved. Students in 2017 were late on two fewer days and had two fewer absences per year on average than the students in 2016.
12-12-18 Babies born in opioid withdrawal have unusually small heads
A new study suggests the drugs may impair brain growth. Babies born dependent on opioids have smaller heads than babies not exposed to the drugs in the womb. The finding, published online December 10 in Pediatrics, raises concerns that the drugs are impairing brain growth during development. And it highlights questions about the safest approach to managing opioid addiction during pregnancy, researchers say. Pregnant women who use opioids — or the drugs methadone or buprenorphine, opioids taken to treat addiction — pass the drugs through the bloodstream to babies. Infants can become dependent on the drugs in the womb, and experience withdrawal symptoms after birth. The disorder, marked by excessive crying, tremors or difficulty sleeping or feeding, is called neonatal abstinence syndrome, or NAS (SN: 6/10/17, p. 16). In the new study, researchers compared the head sizes of close to 860 babies born from 2014 to 2016, half with NAS and half from mothers who had not taken opioids while pregnant. Newborns with NAS had a head circumference nearly 1 centimeter smaller, on average, than babies not exposed to the drugs, the team found. And of the NAS babies, 30 percent had especially small heads. That was true for only 12 percent of babies without the condition. A smaller head is a possible sign of a smaller brain. The new work suggests that for those NAS babies who later have learning and behavioral problems, a contributing factor may be the effect of opioids on brain growth and development, says neonatologist Jonathan Davis.
12-12-18 The disorientated ape: Why clever people can be terrible navigators
The human sense of direction is extraordinarily variable. Now we know why some people are so good at getting lost. IT IS autumn in New York City and a monarch butterfly is setting off on a 4000-kilometre journey to a fir tree on a mountainside in central Mexico, where it will spend the winter. It is autumn in New York City and you come out of a café, set off for your hotel just a few blocks away, take a wrong turn and get utterly lost. Perhaps it is unfair to compare the navigational skills of a human to those of the legendary monarch butterfly but, however you look at it, our sense of direction isn’t up there with the greats. Despite our stunning cognitive abilities, we can be dunces when it comes to finding our way around, and some of us are very good at getting lost indeed. Why we are so bad at navigating has been a mystery for centuries, but now, at last, we have some answers. For a start, the mechanisms of the brain’s GPS are being laid bare. We are also discovering why some people have a better sense of direction than others. The latest findings even address the stereotype of men as better navigators than women. They also show how we can all become better navigators. Although we will never match a monarch butterfly, there are ways we can help ourselves make it back to that hotel. First things first: your sense of direction is not, of course, an actual single sense. What we are talking about here is your ability to get to a destination as quickly and efficiently as possible, without getting lost. To do this, you need to know where you are in relation to landmarks. You must also be able to update your position if you turn a corner, or decide to take a shortcut, say.
12-12-18 Hybrid rice engineered with CRISPR can clone its seeds
The research raises hopes of making bigger crop yields more affordable After more than 20 years of theorizing about it, scientists have tweaked a hybrid variety of rice so that some of the plants produce cloned seeds. No plant sex necessary. The feat, described December 12 in Nature, is encouraging for efforts to feed an increasingly crowded world. Crossing two good varieties of grain can make one fabulous one, combining the best versions of genes to give crops desirable traits such as higher yields. But such hybrid grain marvels often don’t pass along those coveted genetic qualities to all seeds during reproduction. So farmers who want consistently higher yields have to pay for new hybrid seeds every year. This new lab version of hybrid rice would preserve those qualities through self-cloning, says study coauthor Venkatesan Sundaresan, a plant geneticist at the University of California, Davis. Though 400 kinds of plants, including some blackberries and citruses, have developed self-cloning seeds naturally, re-creating those pathways in crop plants has “been harder than anyone expected,” Sundaresan says. He and his colleagues got the idea for the new research while studying “how a fertilized egg becomes a zygote, this magical cell that regenerates an entire organism,” as Sundaresan puts it. The researchers discovered that modifying two sets of genes caused the japonica rice hybrid called Kitaake to clone its own seeds. First the team found that in a fertilized plant egg, only the male version of a gene called BABY BOOM1 found in sperm triggered the development of a seed embryo. So the scientists inserted a genetic starter switch, called a promoter, that let the female version of the same gene do the same job. No male would be necessary to trigger an embryo’s development.
12-12-18 Australia’s ‘marsupial lion’ was a meat-ripping, tree-climbing terror
The most detailed reconstruction yet of Australia’s extinct “marsupial lion” shows it was unlike any animal living today, shredding its prey like a Tasmanian devil, biting like a lion, and climbing like a koala. The first partial remains of the fearsome predator – which went extinct about 45,000 years ago – were discovered in Victoria in the 1850s. British naturalist Richard Owen named it Thylacoleo carnifex – meaning “meat-cutting marsupial lion” – based on its large blade-like teeth and cat-like skull. Other remains of T. carnifex were found in the 1960s and 70s, but it was only in 2002 that the first complete skeleton was discovered in a cave beneath the Nullarbor Plain in Western Australia. In 2005, another two mostly complete skeletons were found in a cave in Naracoorte, South Australia. Since then, Rod Wells at Flinders University and his colleagues have carefully studied the skeletons to better understand the mysterious creature. Their reconstruction shows that T. carnifex would have measured over a metre long and over half a metre tall while standing on all four feet, with a weight of about 100 kilograms. “It was probably the size of a big pig,” says Wells. Like other marsupials, it carried its young in a pouch. Comparisons with living Australian marsupials suggest that T. carnifex was most similar in appearance to the Tasmanian devil, but would have been about 10 times bigger. It had the same stiff back and strong, rigid tail that Tasmanian devils use for balance while tearing apart prey with their paws and teeth, says Wells.
12-12-18 'Planet of the chickens': How the bird took over the world
A study of chicken bones dug up at London archaeological sites shows how the bird we know today has altered beyond recognition from its ancestors. With around 23 billion chickens on the planet at any one time, the bird is a symbol of the way we are shaping the environment, say scientists. Evolution usually takes place over a timescale of millions of years, but the chicken has changed much more rapidly. The rise of the supermarket chicken mirrors the decline in wild birds. "The sheer number of chickens is an order of magnitude higher than any other bird species that's alive today," said Dr Carys Bennett, a geologist at the University of Leicester, who led the study. "You could say we are living in the planet of the chickens." 65.8 billion - the number of chickens slaughtered in 2014, compared to 1.5 billion pigs and 0.3 billion cattle. The researchers used the archaeological record to look at how chickens have changed over the years - and say they are a symbol of this geological era. We are entering the Anthropocene, the period during which human activity has been the dominant influence on climate and the environment. "Human activities have altered the Earth's landscapes, the oceans, atmosphere and land surface," said Dr Bennett. "As the most numerous terrestrial vertebrate species on the planet, with a biology shaped by humans, modern chickens are a symbol of our changed biosphere." She said when future generations examine rocks from our time, they will probably see "tin cans, glass bottles, and bits of material that were once plastic, and amongst that will be bones of chickens". Domesticated animals now make up the majority of animal species on land, shaping the natural world.
12-12-18 When humans are wiped from Earth, the chicken bones will remain
When humans have vanished from the planet, one of the most enduring marks of our impact on Earth will be the sudden appearance in the fossil record of copious chicken bones. Geologists have proposed that the age of humans constitutes a new epoch in Earth’s history, known as the Anthropocene. The explosion in chicken farming and the rapid changes in the form of chickens due to selective breeding make them an ideal sign of our time. “We think they are a really important symbol and potential future fossil of this age, and man’s impact on the planet,” says Carys Bennett at the University of Leicester, UK. The 20th century saw an explosion in the numbers of domesticated chickens all over the world. The current population is now 21.4 billion – more than any other land vertebrate and an order of magnitude greater than any other bird. Over 60 billion are slaughtered every year – a rate of carcass accumulation that is unprecedented in the natural world. The modern broiler chicken – the variety farmed for meat – is now unrecognisable from its wild ancestor, the red jungle fowl. Though chickens were domesticated around 8000 years ago, they have undergone especially marked changes since intensive farming took off in the middle of the 20th century. Today’s chickens grow to become four or five times as heavy as birds from 1957. The leg bone of a juvenile broiler is triple the width and double the length of a red jungle fowl equivalent. The timing of these changes in chickens coincides with other proposed signs of the Anthropocene, such as plastics, fertilisers, fossil fuels and radioactive deposits from nuclear weapons.
12-12-18 Many babies are crummy sleepers, confirming what millions of parents already know
I love to hate the phrase “sleep like a baby.” It’s a beautiful example of a saying that’s based on the exact opposite of what it’s intended to convey. Babies (many of them, anyway) are rotten sleepers. During my last pregnancy, I wondered if I might luck out with a good sleeper. Or at least an average sleeper. But my third little sweetie didn’t deliver. At nearly 8 months, he (and I) still wake up several times a night. That’s a drag, but not a surprising or big one. This time around, I had very low expectations. A recent survey of 388 Canadian mothers supports those rock-bottom expectations. It found that many babies don’t sleep through the night. At 6 months of age, 43 percent of infants were sleeping an uninterrupted 8 hours during the night. That means that 57 percent of these babies — more than half — were not. When researchers relaxed their “overnight” definition to mean 6 hours of blissful slumber, 62.4 percent of babies hit the mark; 37.6 percent did not. That’s 1 in 3 babies not sleeping 6 hours at a go — a large chunk of the infant population. The researchers found some differences among the sleepers and nonsleepers. Breastfed babies were much less likely to sleep in long, solid blocks than formula-fed babies. And baby boys seemed to be slightly worse sleepers than baby girls, with fewer sleeping 6 hours or more at a stretch at age 6 months. The results raise a question: Are all of those night wakings bad for the baby or the mother? Follow-up tests didn’t find any ill effects, the researchers report. Sleepers and nonsleepers performed similarly on mental and physical tests. And moms of sleepers and nonsleepers scored similarly on mood tests.
12-12-18 Monkeys chill out just from seeing their friends being groomed
Monkeys become more relaxed if they simply watch one monkey grooming another. “If you walk down a street and see someone being nice to someone else, it gives you a warm feeling inside,” says Stuart Semple of the University of Roehampton in London, UK. It seems monkeys experience the same thing. With his student Juliette Berthier, Semple studied 20 female Barbary macaques living in a semi-free ranging group in a Safari park-like environment in a UK forest. When a macaque saw another being groomed, the observer started performing fewer “self-directed” behaviours such as scratching and yawning. These behaviours are thought to be signs of anxiety, so it seems the observer macaques became less anxious after seeing another macaque being groomed. “Merely watching grooming is in itself relaxing for monkeys,” says Semple. The observer macaques also became more likely to participate in grooming themselves, either as groomer or groomee. Furthermore, they displayed more friendly behaviours in general, such as cuddling other macaques or feeding with them. The phenomenon is similar to “emotional contagion”: humans become more cheerful if we meet someone cheerful, even online, and some parrots start playing when they hear other parrots making playful sounds. But in this case the effect lasted longer, in some cases 30 minutes. The finding may help explain the phenomenon of “ASMR” (autonomous sensory meridian response). Some people experience a pleasant, calming tingle when watching videos of other people whispering or performing actions like tapping their fingers on surfaces.
12-12-18 Acne study reveals genes for hair follicles are partly to blame
A large genetic study of people with acne could pave the way for new treatments. The study looked at the DNA of 27,000 people, including over 5000 with severe acne, and identified genetic differences that were more common in people with the condition. It found that many of these genetic variants influenced the formation of hair follicles, making it a significant but previously unknown risk factor in developing acne. There have been few advances in acne treatment for decades, says Jonathan Barker at the National Institute for Health Research, UK, who led the study. He hopes that using the new genetic information could lead to much more effective drugs and treatment for the condition. Acne is a common skin condition affecting 80 per cent of people aged 11-30, causing spots, oily skin and sometimes skin that is hot or painful to touch. In severe cases it can cause significant discomfort and distress and can lead to permanent scarring. The most effective current treatment for acne is isotretinoin, but the team said this has significant side effects including muscle aches and dry skin as well as birth defects if taken by pregnant women.
12-12-18 ‘Little Foot’ skeleton analysis reignites debate over the hominid’s species
Researchers disagree over resurrecting a defunct species name. A nearly complete hominid skeleton known as Little Foot has finally been largely freed from the stony shell in which it was discovered in a South African cave more than 20 years ago. And in the first formal analyses of the fossils, researchers say the 3.67-million-year-old Little Foot belonged to its own species. In four papers posted online at bioRxiv.org between November 29 and December 5, paleoanthropologist Ronald Clarke of the University of the Witwatersrand in Johannesburg and colleagues assign Little Foot to a previously proposed species, Australopithecus prometheus, that has failed to gain traction among many researchers. Clarke has held that controversial view for more than a decade (SN: 5/2/15, p. 8). He found the first of Little Foot’s remains in a storage box of fossils from a site called Sterkfontein in 1994. Excavations of the rest of the skeleton began in 1997. Many other researchers, however, regard Little Foot as an early member of a hominid species called Australopithecus africanus. Anthropologist Raymond Dart first identified A. africanus in 1924 from an ancient youngster’s skull called the Taung Child. Hundreds of A. africanus fossils have since been found in South African caves, including Sterkfontein. One of those caves, Makapansgat, produced a partial braincase that Dart assigned to A. prometheus in 1948. But Dart dropped that label after 1955, assigning the braincase and another Makapansgat fossil to A. africanus.
12-12-18 Coral likes to make its ocean home in places with noisy neighbours
Corals seem to appreciate noisy neighbours. Free floating coral larvae are more likely to settle on a surface – where they then begin growing into a stony reef – if the water is alive with the rumbling noise of a healthy fish population. The finding could be useful for efforts to restore damaged reefs to health. Tiny coral larvae drift with the ocean currents, looking for a place to settle down by sensing multiple environmental cues including light, temperature and the chemicals released by other marine organisms. Previous research suggests that coral larvae may also be picky about the sound condition underwater. To investigate further, Amy Apprill at the Woods Hole Oceanographic Institution in Massachusetts and her colleagues collected 990 mustard hill coral larvae (Porites astreoides) and placed equal numbers of them in 18 sealed boxes filled with filtered seawater. Nine of the boxes were transparent and the other nine were blackened to prevent light exposure. The team placed the boxes in the Caribbean: six on a healthy, fish-abundant reef, another six on a less robust reef and the last six at a barren site. All three sites have similar light exposure but differ significantly in the level and quality of sound. An environment with a healthy population of large fish and coral has louder low frequency sounds, such as deep grunting and chirping noises. In contrast, the barren site lacks these and is much quieter overall, save for the high-frequency sounds from snapping shrimp.
12-11-18 Nearly 200 Great Barrier Reef coral species also live in the deep sea
The unexpected coral bounty means deep reefs have a richer biodiversity than thought. Nearly 200 species of Great Barrier Reef corals have found a second home in the deep ocean. That’s six times as many species as previously thought to be living in the dark, cold waters off northeastern Australia, researchers report December 11 in Proceedings of the Royal Society B. Perhaps more important than the number of species cataloged at those depths is the fact that every coral evolutionary family is represented, offering a potential boon for conservation efforts. “The deep reef is a lot more diverse and interesting than we thought,” says coauthor Paul Muir, a coral biologist at the Museum of Tropical Queensland in Townsville, Australia. “It’s a bit of a good news story, and there aren’t many of those around at the moment.” As climate change makes some ocean waters warmer, corals are experiencing more frequent severe bleaching events than they did just a few decades ago (SN: 2/3/18, p. 16). Scientists are trying to learn which species might be able to survive, and where, as ocean conditions change.
12-11-18 Here’s what was surprising about Kilauea’s 3-month-long eruption
Scientists have learned new things about how craters collapse and life rebounds under the sea. After a stunningly explosive summer, Kilauea, the world’s longest continuously erupting volcano, finally seems to have taken a break. But the scientists studying it haven’t. Reams of new data collected during an unprecedented opportunity to monitor an ongoing, accessible eruption are changing what’s known about how some volcanoes behave. “It was hugely significant,” says Jessica Larsen, a petrologist at the University of Alaska Fairbanks, and “a departure from what Kilauea had been doing for more than 35 years.” The latest eruption started in May. By the time it had ended three months later, over 825 million cubic meters of earth had collapsed at the summit. That’s the equivalent of 300,000 Olympic-sized swimming pools, Kyle Anderson, a geophysicist with the U.S. Geologic Survey in Menlo Park, Calif., said December 11 in a news conference at the annual meeting of the American Geophysical Union. As the summit crater deflated, magma gushed through underground tunnels, draining out through fissures along an area called the lower eastern rift zone at a rate of roughly 50 meters per day. That lava eventually covered 35.5 square kilometers of land, Anderson and his colleagues reported in a study published December 11 in Science. The volcano also taught scientists a thing or two.
12-11-18 Gene study unravels redheads mystery
Eight genes linked to red hair have been discovered by scientists, helping to shed light on how redheads inherit their distinctive locks. The Edinburgh University-led research has been described as the largest genetic study of hair colour to date. It had been thought red hair was controlled by a single gene, MC1R, with versions passed on from both parents. However, not everyone carrying two red-haired versions is a redhead, meaning that other genes had to be involved. The team examined DNA from almost 350,000 people who had taken part in the UK Biobank study. When they compared redheads with people with brown or black hair, scientists identified eight previously-unknown genetic differences that are associated with ginger locks. The team also looked at the functions of the genes they identified and found some of them work by controlling when MC1R is switched on or off. The researchers also uncovered differences in almost 200 genes associated with blondes and brunettes. Prof Albert Tenesa, of the university's Roslin Institute, said: "We are very pleased that this work has unravelled most of the genetic variation contributing to differences in hair colour among people." Prof Ian Jackson, of the medical research council human genetics unit at the university, said: "We were able to use the power of UK Biobank, a huge and unique genetic study of half a million people in Britain, which allowed us to find these effects." The study, published in Nature Communications, was funded by the Medical Research Council and the Biotechnology and Biological Sciences Research Council.
12-11-18 Biologists are one step closer to creating snake venom in the lab
Researchers have grown organoids that mimic the venom glands of snakes. Labs growing replicas of snakes’ venom glands may one day replace snake farms. Researchers in the Netherlands have succeeded in growing mimics of venom-producing glands from multiple species of snakes. Stem cell biologist Hans Clevers of the Hubrecht Institute in Utrecht, the Netherlands, reported the creation of these organoids on December 10 at a joint meeting of the American Society for Cell Biology and the European Molecular Biology Organization. If scientists can extract venom from the lab-grown glands, that venom might be used to create new drugs and antidotes for bites including from snakes that aren’t currently raised on farms. Up to 2.7 million people worldwide are estimated to be bitten by venomous snakes each year. Between about 81,000 to 138,000 people die as a result of the bite, and as many as roughly 400,000 may lose limbs or have other disabilities, according to the World Health Organization. Antivenoms are made using venom collected from snakes usually raised on farms. Venom is injected into other animals that make antibodies to the toxins. Purified versions of those antibodies can help a bitten person recover, but must be specific to the species of snake that made the bite. “If it’s a fairly rare or local snake, chances are there would be no antidote,” Clevers says.
12-11-18 Getting goose bumps could boost hair growth
The same nerves, muscles and hormones work together to stimulate hair follicles. Getting goose bumps doesn’t just make hairs stand on end; it may also help hair grow. Nerves and muscles that raise goose bumps also stimulate stem cells in the skin to make hair follicles and grow hair. Ya-Chieh Hsu, a stem cell researcher at Harvard University, reported the unpublished findings December 9 at the joint meeting of the American Society for Cell Biology and the European Molecular Biology Organization. Getting goose bumps when it’s cold may encourage animals’ fur to grow thicker, Hsu said. Nerves that are part of the sympathetic nervous system — which controls pupil dilation, heart rate and other automatic processes — nestle next to stem cells that will create hair follicles, Hsu and her colleagues found. Usually nerves are wrapped in a protective coating called myelin, like electrical wire sheathed in plastic. But Hsu’s group found that the nerves’ ends were naked where they meet hair follicle stem cells, like wires stripped at the tips to make contacts with electrical nodes. The nerves secrete the hormone norepinephrine. That hormone is necessary for hair growth, the researchers found. Those findings might help explain why hair loss is a side effect of drugs known as beta-blockers, which interfere with norepinephrine’s action.
12-10-18 Spray-on gel slows down the regrowth of tumours after cancer surgery
A way of destroying cancers with our own immune system is a long-held goal of medicine. Now a new twist on such immunotherapy has given promising results in mice. The treatment is a gel sprayed on to the wound left when a tumour is cut out. The targeted delivery means nearby immune cells start killing cancer cells, both at the wound and elsewhere in the body – but it doesn’t cause a potentially harmful body-wide immune reaction. Several kinds of immunotherapy have been developed into treatments in the past few years. Most give people just a few extra months of life rather than being a cure. But the immune system has many different arms, so the search continues for an approach that more effectively harnesses its power. Several ongoing trials are looking at ways to block a molecule called CD47, which is present on many tumour cells and helps them evade the immune system by giving off a “don’t eat me” signal. But antibodies against this molecule lead not only to death of tumour cells but also to destruction of red blood cells, which normally have CD47 on their surface. Zhen Gu at the University of California, Los Angeles and colleagues have found a way to make the immune reaction more targeted. They took mice with skin cancer and cut out most but not all of the tumour, as can happen when human patients have cancer surgery. Then they sprayed the wound with a gel containing antibodies against CD47, as well as a chemical that makes the tissue less acidic, a way of revving up immune cells called macrophages.
12-10-18 The most comfortable running shoes may actually increase injury risk
Highly-cushioned running shoes are meant to protect against injuries, but they may actually do the opposite by changing the way we run, research suggests. Every year, it’s estimated that at least one-third of runners get stress fractures, shin splints or muscle or joint injuries caused by repeated pounding of the pavement. Many shoe manufacturers have added extra padding to try to soften the impact on the legs, but injury rates have not decreased as a result. A new study suggests this is because the extra cushioning changes the spring-like mechanics of the legs as they run, which actually means we experience more tissue damage with every stride. Juha-Pekka Kulmala at the University of Helsinki in Finland and his colleagues studied the biomechanics of 12 healthy men aged 22 to 32 as they ran in two shoe types – a regular sneaker with 33 millimetres of cushioning under the heel and 22 millimetres under the forefoot, and a highly-cushioned “maximalist” sneaker with a 43-millimetre heel and 37-millimetre forefoot height. The participants ran at two different speeds – 10 and 15 kilometres per hour – along a 30-metre platform that measured how hard their feet hit the ground. They also wore reflective stickers that allowed video cameras to capture their motion. At both speeds, the runners landed on their feet harder when they wore the maximalist sneakers than the regular kind. The peak impact force was 6 per cent higher on average at the slower running speed and 11 per cent higher at the faster speed.
12-10-18 City living makes urban male frogs far more attractive to females
Male frogs that live in cities make more complex mating calls than their forest-dwelling cousins, and that makes them much more attractive to female frogs. As animals move into urban environments, they face different pressures from natural selection, resulting in rapid evolution of different behaviours. Previous research has found that birds, frogs and grasshoppers sing or call differently in noisy urban areas, but few studies have addressed in detail how this affects their needs to attract a mate and avoid predators and parasites. Male túngara frogs gather at night in puddles to call and attract females. The main part of their call, the “whine”, sounds like a sci-fi laser beam, but some add elements called “chucks”, which sound like very short duck quacks. However, making a more elaborate call raises the risk of attack by bats or biting midges. Wouter Halfwerk of the Free University Amsterdam and colleagues recorded males in urban and forest locations in Panama. The urban males called more often and made more complex sounds than the forest males, with more and louder chucks. These complex calls proved to be irresistible to females. When the researchers played recordings of an urban male and a forest male from two speakers, three quarters of the females approached the one playing the urban call. To explain why a different call evolved in the city, the researchers tried playing the same recorded call from a speaker in different locations. At urban sites, the calls attracted fewer female frogs, bats and midges. This suggests that in cities, the pressure to attract mates is stronger and the pressure to avoid predators and parasites is lower.
12-10-18 Amount of deep life on Earth quantified
Scientists have estimated the total amount of life on Earth that exists below ground - and it is vast. You would need a microscope to see this subterranean biosphere, however. It is made up mostly of microbes, such as bacteria and their evolutionary cousins, the archaea. Nonetheless, it represents a lot of carbon - about 15 to 23 billion tonnes of it. That is hundreds of times more carbon than is woven into all the humans on the planet. "Something like 70% of the total number of microbes on Earth are below our feet," said Karen Lloyd from the University of Tennessee at Knoxville, US. "So, this changes our perception of where we find life on Earth, from mostly on the surface in things like trees and whales and dolphins, to most of it actually being underground," she told BBC News. PROF Lloyd is part of the Deep Carbon Observatory (DCO) project, a near-decade long effort to identify how the ubiquitous element is cycled through the Earth system. The consortium is reporting its latest discoveries here at the American Geophysical Union (AGU) annual Fall Meeting in Washington DC. The mass numbers it quotes can only be a rough estimate. They are derived from multiple studies that have dug or drilled several kilometres into the crust, both on the continents and at sea. Scientists will routinely pull up rock and other sediment samples and count the number living cells in a given volume. The DCO teams have taken these inventories and used models to construct a broader picture of Earth's total biomass.
12-9-18 'Digital museum' brings millions of fossils out of the dark
The bid to create a "global digital museum" has been welcomed by scientists, who say it will enable them to study valuable specimens that are currently "hidden" in museum drawers. Museums including London's Natural History Museum and the Smithsonian in Washington DC are involved. They have set out ambitious plans to digitise millions of specimens. Digitally recording the 40 million fossils at the Smithsonian will take an estimated 50 years. But five years into the project, the team says it is "bringing dark data into the light" for crucial research. Kathy Hollis from the Smithsonian Museum of Natural History, who is leading the project there, explained: "We are trying to make our entire collection available digitally for researchers to use online from anywhere in the world. "And we're pretty sure that this is the largest fossil collection in the world. "We have over 40 million specimens in the collection - it records the entire history of life, so if it has a fossil representative, it's likely here within the collection." Items on public display in museums represent only a tiny fraction of the collections stored away in drawers. "And there are drawers here in the museum that haven't been opened for decades," said Kathy Hollis. That is problematic if scientists want to use all of those specimens - the collective evidence of millions of years of evolution on our planet - to understand how life works and changes. (Webmaster's comment: All the missing links and transitional fossels are all there. All the evidence for evolution one could ever want.)
12-8-18 The evolution of punishment
It's not always about the common good. Imagine someone gets caught cheating at a poker game. What's next? After the accusations and denials, the cheater usually suffers some form of harm — confiscated winnings, ridicule, maybe ostracism. Perhaps justifiably so: Most people think that cheaters deserve punishment. This is a familiar sentiment. Humans are quick to recognize wrongdoing and to mete out penalties in response. Sometimes, we seem to enjoy the act of retribution. Punishment takes diverse and complex forms, ranging from mocking laughter to imprisonment. Sometimes, the affronted party does the punishing; other times it's a third party. Yet it's also costly to give someone their just deserts. When an adult confiscates a child's toy for bad behavior, both are in for a rough afternoon. Which raises the question: Why do we punish in the first place? One answer is that punishment evolved to promote the greater good and prevent tragedies of the commons. This is the altruistic approach. Yes, punishment might be costly for the punisher, but (so the theory goes) it generates downstream benefits for others — stabilizing cooperation, enforcing just rules, deterring free-riders. Punishment is probably essential for maintaining and enforcing norms, laws, and customs. Yet its origins appear to trace back to a time before robust human societies, perhaps even before we had language to articulate the rules. Recent research has identified contexts where dominant chimps seem to punish freeloaders. So perhaps punishment preceded the benefits it generates. After all, punishment doesn't always promote the greater good. It's been used to oppress minorities, foster discrimination, exploit disadvantaged groups, maintain sexist and racist social norms, and keep subjugated populations in line. In experimental setups, "antisocial punishment" has been observed, in which cooperative individuals are punished by others because they contributed to a public good. Punishment can be detrimental, even in the long run. These observations suggest that altruism is, at best, only a small part of the story. Moreover, even if punishment is crucial for achieving some forms of social cooperation, it might not have originated for that reason. Instead, perhaps it came about for another reason entirely, and only later assumed a socially beneficial role. So, if not for the greater good, just how did punishment evolve?
12-7-18 The threat of genetically edited babies
“Gene editing is here,” said Marc Thiessen, and it poses “an enormous threat” to humanity. A Chinese scientist, He Jiankui, last week claimed that he used the gene-editing technique known as CRISPR to alter the DNA of two embryos to make them resistant to HIV, and then implanted these edited human beings in their mother’s womb, leading to their live birth. The scientific community has reacted to He’s work with outrage, essentially saying it’s “premature.” But the real question is “Should we be doing this at all?” Unlike gene therapy, in which doctors use CRISPR to treat individual patients suffering from genetic diseases, gene editing permanently changes the genetic code of a human being, so that the new code is passed on to future generations. This opens “a Pandora’s box,” in which scientists could produce “made-to-order babies” with superior intellect and athletic skills, tall stature, and whatever color hair, skin, and eyes the parents deemed beautiful. In a genetically modified future, the rich could pay to “lock in their privilege” by buying super-offspring pruned of imperfections, while the poor would go “unenhanced.” If science continues down this road, we will cross “a moral line from which there may be no return.” (Webmaster's comment: It's going to happen. Get used to it!)
12-7-18 Editor’s letter
The age of the designer baby isn’t here yet, but it’s getting close. Chinese researcher He Jiankui triggered outrage last week with his announcement that he’d created the world’s first genetically altered infants, having tweaked their embryos to make them resistant to HIV. (See Best Columns: The U.S.) Whether or not He’s claim of a breakthrough is true—his data hasn’t been published or peer reviewed—the vital point is that it could be. For the past decade, scientists around the world have been modifying the blueprint of human life with the genome-editing tool CRISPR. A U.S. team last year altered the DNA of embryos to replace defective genes that cause a hereditary heart condition. (Unlike He, they did not implant their experimental embryos in a woman’s womb.) This technology could eventually wipe out all hereditary diseases, including Alzheimer’s and cystic fibrosis. But you don’t have to be a science-fiction writer to see how prospective parents might use it to gift their offspring with other advantages in life. Gene editing could be used to boost IQ and athleticism. Discrimination against the short of stature and dark of skin is still rife, and so parents might choose to make their children tall and light-skinned. In a genetically modified future, society could be even more divided between the rich, who would be able to afford “perfect” designer offspring, and the unenhanced poor. The bonds between parent and child could also be irrevocably changed. When I look at my son and daughter, I get a small thrill when I spot hereditary traits: my wife’s eyes, my hair, my mother’s quiet stubbornness. Familiar imperfections are no less endearing. How will it feel to look at your child and instead recognize features you’ve ordered from the Acme Super Kid catalog: Husky-blue eyes with guaranteed 20/20 vision, Michael Jordan’s leaping ability and wingspan, Einstein’s brainpower. Would you feel the pride of a parent, or the pride of an engineer marveling at his latest creation?
12-7-18 Brain scans reveal why your brain forgets details
Our brains are much better at recalling vague pieces of information than precise details, according to two studies. One possible evolutionary explanation is that abstract ideas could be more helpful than specifics for getting through daily life. “Imagine you get bitten by a dog in the park. If you want to prevent being bitten again, it doesn’t help to just remember that this particular cute, little, white dog in this particular park has bitten you. What you want to memorise is that if you meet a free running dog in a park, it can bite,” says Maria Wimber at the University of Birmingham in the UK, who presented her teams’ findings in November at the Society for Neuroscience annual meeting in San Diego. To find out how information is prioritised when we reconstruct a memory in our brain, she and her team set up studies to determine where in the brain we store different information, and in what sequence we recall bits of memories from those different places. Wimber’s colleague Catarina Ferreira found that our brains emphasise categorical information. She asked 22 people to memorise 128 pairs of objects they were shown on a screen, consisting of a scene and an unrelated object – such as a mountain paired with a kiwi fruit. Two days later, the team showed the participants just the images of the scenes and asked them to recall the associated object, whilst having their brains MRI scanned. On average, participants could correctly recall the general category the associated object fell into 79 per cent of the time.
12-7-18 Football and children’s brains
Just a single season of football can damage the brain development of young players, a new study suggests. Researchers fitted 60 youth and high school football players with a telemetry system to measure the impacts they received to the head. The players were split into two groups—those who received a lot of knocks on the head and those who received relatively few—and were given a resting-state functional brain scan before and after the season. From those scans, the researchers found that in the high-impact group the “pruning” process in the brain—when unneeded synapses are removed to make room for new and important neural connections—had been markedly disrupted. “Pruning is an essential part of brain development,” study co-author Gowtham Krishnan Murugesan, from UT Southwestern Medical Center in Dallas, tells ScienceDaily.com. “By getting rid of the synapses that are no longer used, the brain becomes more efficient with aging.” Murugesan recommends that youth teams replace high-impact practice drills with low- or no-impact drills to reduce the number of hits kids receive.
12-7-18 Kids gain weight like mom
Children are more likely to pile on the pounds if their moms do the same, new research has found. Scientists at the Norwegian University of Science and Technology examined the activity levels of more than 4,400 kids and their parents over an 11-year period. They found that mothers whose exercise levels dropped as their children were growing up were more likely to have overweight teenagers. But when a mom’s weight went down, so did their children’s body mass index. No such correlation was found when fathers shed pounds. That could be because mothers still tend to be responsible for planning activities in the home and what’s eaten day to day, although the researchers note that they didn’t study these issues. “Parents have a major impact on their children’s health and lifestyle,” co-author Marit Naess tells The Daily Telegraph (U.K.). “Behaviors that lead to obesity are easily transferred from parent to child.”
12-7-18 A gut-brain link for Parkinson’s gets a closer look
The misfolded proteins may start with microbes in the digestive system. Martha Carlin married the love of her life in 1995. She and John Carlin had dated briefly in college in Kentucky, then lost touch until a chance meeting years later at a Dallas pub. They wed soon after and had two children. John worked as an entrepreneur and stay-at-home dad. In his free time, he ran marathons. Almost eight years into their marriage, the pinky finger on John’s right hand began to quiver. So did his tongue. Most disturbing for Martha was how he looked at her. For as long as she’d known him, he’d had a joy in his eyes. But then, she says, he had a stony stare, “like he was looking through me.” In November 2002, a doctor diagnosed John with Parkinson’s disease. He was 44 years old. Carlin made it her mission to understand how her seemingly fit husband had developed such a debilitating disease. “The minute we got home from the neurologist, I was on the internet looking for answers,” she recalls. She began consuming all of the medical literature she could find. With her training in accounting and corporate consulting, Carlin was used to thinking about how the many parts of large companies came together as a whole. That kind of wide-angle perspective made her skeptical that Parkinson’s, which affects half a million people in the United States, was just a malfunction in the brain. “I had an initial hunch that food and food quality was part of the issue,” she says. If something in the environment triggered Parkinson’s, as some theories suggest, it made sense to her that the disease would involve the digestive system. Every time we eat and drink, our insides encounter the outside world.
12-7-18 Two new books explore the science and history of the 1918 flu pandemic
‘Pandemic 1918’ and ‘Influenza’ chronicle the flu’s devastating history and uncertain future. The U.S.S. Leviathan set sail from Hoboken, N.J., on September 29, 1918, carrying roughly 10,000 troops and 2,000 crewmen. The ship, bound for the battlefields in France, had been at sea less than 24 hours when the first passengers fell ill. By the end of the day, 700 people had developed signs of the flu. The medical staff tried to separate the sick from the healthy, but that soon proved impossible. The poorly ventilated bunkrooms filled with the stench of illness. The floor grew slippery with blood from many nosebleeds, and the wails of the sick and dying echoed below deck. Bodies piled up and began decomposing, until finally the crew was forced to heave them into the sea. It was the stuff of nightmares. This is just one of the grisly scenes in Pandemic 1918 by historian Catharine Arnold. The book details how the movement of troops during World War I helped drive the spread of a deadly strain of influenza around the globe — from the American Midwest to Cape Town, South Africa, to New Zealand and beyond. Scientists have yet to conclusively determine where that flu originated; Arnold suggests it was on a massive military base in Étaples, France. But all agree that the pandemic that became known as the Spanish flu didn’t begin in Spain. And the disease, which ultimately killed more than 50 million people, wasn’t caused by any ordinary influenza strain. Grim eyewitness accounts chronicle the gory details of how this virus differed. Victims often bled from the nose or mouth, writhed in pain and grew delirious with fever. Their faces turned dusky blue as their lungs filled with pus. Healthy men and women in their prime were dying, sometimes within days of falling ill.
12-6-18 The uterus may play a role in memory
Rats that had their uterus removed had memory deficits. The uterus is best known for its baby-growing job. But the female organ may also have an unexpected role in memory, a study in rats suggests. The results, published online December 6 in Endocrinology, counter the idea that the nonpregnant uterus is an extraneous organ. That may have implications for the estimated 20 million women in the United States who have had hysterectomies. In the study, female rats either underwent removal of the uterus, ovaries, both organs or neither. Six weeks after surgery, researchers led by behavioral neuroscientist Heather Bimonte-Nelson of Arizona State University in Tempe began testing the rats on water mazes with platforms that were hidden just below the surface. Compared with the other groups, rats that lacked only a uterus were worse at remembering where to find the platforms as the tests turned progressively harder. The results suggest that signals that go from the uterus to the brain are somehow involved in remembering multiple bits of information at the same time. Rats lacking just a uterus had differences in their hormone levels, too, even though these rats kept their hormone-producing ovaries. Researchers have known for decades that hormones released by the ovaries can influence the brain. But finding that the uterus on its own can influence memory is a surprise, says neuroendocrinologist Victoria Luine of Hunter College of the City University of New York. Because many women have their uteruses removed but keep their ovaries, “this revelation brings up some interesting questions to explore.”
12-6-18 Here’s how geckos (almost) walk on water
High-speed video reveals the physics of how the animals move almost as fast in water as on land. Add water aerobics to the list of the agile gecko’s athletic accomplishments. In addition to sticking to smooth walls and swinging from leaves, geckos can skitter along the surface of water. By slapping the water with all four limbs to create air bubbles and exploiting the surface tension of water, the reptiles can travel at speeds close to what they can achieve on land, according to a new analysis of high-speed video footage described December 6 in Current Biology. In the world of water walkers, geckos occupy an awkward intermediate turf, says study coauthor Jasmine Nirody, a biophysicist at Rockefeller University in New York City and Oxford University. Small insects like water striders use surface tension, created by water molecules sticking together, to stay afloat. Bigger animals like basilisk lizards slap the surface of the water, creating air pockets around their feet that reduce drag and keep the lizards mostly above the water’s surface. But an animal needs to be fairly large to generate enough force to hold itself out of the water using that strategy. “Geckos fall smack-dab in the middle” size-wise, Nirody says. “They shouldn't really be able to do this at all.” And yet, when her colleague Ardian Jusufi of the Max Planck Institute for Intelligent Systems in Stuttgart, Germany, was vacationing in Singapore, he noticed small geckos skittering across the surface of puddles. Back in the lab, the team filmed eight flat-tailed house geckos (Hemidactylus platyurus) crossing a tank of water, then slowed the footage to get a closer look at the action.
12-6-18 A 5,000-year-old mass grave harbors the oldest plague bacteria ever found
An ancient woman’s teeth might help reveal how the deadly disease got its start. A long-dead Scandinavian woman has yielded bacterial DNA showing that she contracted the earliest known case of the plague in humans. DNA extracted from the woman’s teeth comes from a newly identified ancient strain of Yersinia pestis, the bacterium that causes plague, the oldest ever found. The woman’s bones, which date from 5,040 to 4,867 years ago, were found nearly 20 years ago in a mass grave at an ancient farming site in Sweden. Teeth from an adult male in the same grave contain traces of the same plague variant, say evolutionary geneticist Simon Rasmussen of the University of Copenhagen and colleagues. But plague DNA from the woman is better preserved, the team reports online December 6 in Cell. Comparisons of the newly found Y. pestis strain with other ancient and modern strains suggest that a plague epidemic emerged more than 5,000 years ago in densely populated farming communities in southeastern Europe. Then the plague spread elsewhere, including to Scandinavia, via trade routes, Rasmussen’s team concludes. That ancient epidemic apparently contributed to sharp population declines in Europe that began as early as 8,000 years ago (SN: 11/2/13, p. 12). In particular, the scientists suspect that an early form of plague developed among southeastern Europe’s Trypillia culture between 6,100 and 5,400 years ago. Trypillia settlements were the first to bring enough people into close contact to enable the evolution of a highly infectious version of Y. pestis, the team suggests.
12-6-18 Exclusive: Controversial skeleton may be a new species of early human
More than twenty years after it was first discovered, an analysis of a remarkable skeleton discovered in South Africa has finally been published – and the specimen suggests we may need to add a new species to the family tree of early human ancestors. The analysis also found evidence that the species was evolving to become better at striding on two legs, helping us to understand when our lineage first became bipedal. The specimen, nicknamed “Little Foot”, is a type of Australopithecus, the group of hominins to which the famous fossil “Lucy” belonged. Lucy’s species is called A. afarensis, but we know of several other species of these human-like primates living in Africa around 2 million years ago, including A. africanus. The findings have come out amidst a long-running controversy over who should have access to the fossil. As a result, the team that has been working on the fossil for decades have published their first papers online before peer review was complete, to ensure their work comes out before the studies of a second research group that has been granted access to the specimen. The Little Foot fossil came to light in the 1990s. Ronald Clarke of the University of the Witwatersrand in Johannesburg, South Africa was asked to go through a collection of bones from Sterkfontein Cave in South Africa. In 1994 he found that four foot bones, thought to belong to monkeys, actually resembled existing fossils belonging to the Australopithecus group. The foot bones were quite small, prompting Clarke’s now-deceased colleague Phillip Tobias to dub them “Little Foot”, in reference to the Bigfoot hominin that some believe roams North America. In 1997, Clarke and two colleagues found more of the skeleton encased in rock within the same cave.
12-6-18 Volcanic eruptions that depleted ocean oxygen may have set off the Great Dying
Asphyxiation killed off a lot of marine species 252 million years ago. A massive series of volcanic eruptions in Earth’s distant past left ocean creatures gasping for breath. Greenhouse gases emitted by the volcanoes dramatically lowered oxygen levels in the oceans, a deadly scenario that may have been the main culprit in the Great Dying, researchers report. Earth scientist Justin Penn of the University of Washington in Seattle and colleagues mapped out just how hot the oceans got at the time of the greatest mass extinction on Earth, about 252 million years ago, at the end of the Permian Period. From those climate simulations, the team investigated where the hot water led to ocean anoxia, dangerously low concentrations of dissolved oxygen. Then, the team combined those data with the oxygen requirements of modern ocean dwellers. The scientists determined that hypoxia — a lack of sufficient oxygen for species’ metabolic needs — could have been the primary culprit behind the die-off. The research, published in the Dec. 7 Science, also predicts that the effects of hypoxia would have been worst at polar latitudes, and available fossil data support that result. “Anoxia has been invoked as a primary kill mechanism for the marine extinctions for 20 years,” says Lee Kump, a geochemist at Penn State who wrote a commentary on the finding in the same issue of Science. But what’s unique about this study is the inclusion of how that anoxia affects organisms living in different ecological niches within the oceans, he says. In the Great Dying, as many as 90 percent of all marine species and 70 percent of terrestrial vertebrate species died off. Massive volcanic eruptions, discharging in pulses that began about 300,000 years before the onset of the extinction event, were almost certainly the trigger for the Great Dying (SN: 9/19/15, p. 10).
12-5-18 Bacteria could protect old paintings from pigment-eating microbes
Pigment-eating microbes play a part in degrading priceless paintings, but other microbes may help us to save them. Just like our bodies, oil paintings are home to a community of microorganisms, but few studies have attempted to describe them. To learn more about the microbes that live on paintings, Elisabetta Caselli of the University of Ferrara, Italy, and colleagues sampled tiny sections of Incoronazione della Virgine, a work completed in 1620 by the Italian painter Carlo Bononi. The canvas was hung on the ceiling of the Basilica of Santa Maria in Vado in Ferrara until an earthquake damaged the church in 2012. The researchers isolated multiple strains of Staphylococcus and Bacillus bacteria that were living on the painting, as well as thread-like fungi from four genera, including Aspergillus, Penicillium, Cladosporium, and Alternaria. They also identified pigments such as red and yellow earths and red lac that could be nutrient sources for the microorganisms. As a clinical microbiologist, Caselli has spent years researching ways to eliminate harmful microbes in hospitals. Her team has found that detergents containing spores of harmless Bacillus bacteria can counteract the growth of pathogens, so they tried the same approach to help preserve paintings. Their Bacillus treatment almost completely inhibited the growth of bacteria and fungi isolated from the painting. Further tests will be needed to make sure the treatment would not be damaging to the painting itself, Caselli says.
12-5-18 Fossil blubber shows ichthyosaurs were warm blooded reptiles
The discovery of blubber in an ichthyosaur fossil suggests these ancient marine reptiles were probably warm blooded, as has long been suspected. Icthyosaurs have a striking resemblance to modern dolphins. They evolved from land reptiles that colonised the seas 250 million years ago and thrived until around 90 million years ago, meaning they lived alongside the dinosaurs. A 180-million-year-old fossil, found in Germany, is so extraordinarily well preserved that pieces of the skin removed for analysis were still flexible. It shows that at least some ichthyosaurs had smooth, scaleless skin underlain by blubber, making them even more like dolphins than we thought. All modern sea animals with blubber either maintain a constant body temperature, like whales and seals, or keep their body well above the water temperature, like the leatherback turtle, says team member Johan Lindgren of Lund University in Sweden. “At the very minimum, it’s what you see in the leatherback turtle today,” he says. It’s also long been suspected that ichthyosaurs had dark backs and light undersides like many of the animals that live in the open ocean today. This countershading makes them harder to see when viewed from below or above. When the team looked at the skin of the fossil ichthyosaur under a microscope, they saw what appear to be the remnants of individual pigment cells. They are virtually identical to the pigment cells of modern reptiles, which have a distinctive branched structure. The variations in the distribution of these cells suggest the animal had countershading.
12-5-18 Baboons live for months after getting genetically modified pig hearts
GENETICALLY modified pig hearts have been successfully transplanted into baboons for the first time. The monkeys lived at least 90 days, suggesting the research could move onto human clinical trials. Eventually, the hope is that pig organs could help fill the gap between the need for transplants and a lack of donors. Bruno Reichart at the Walter Brendel Centre of Experimental Medicine in Germany and his team used pig hearts modified to produce human proteins and to block carbohydrates that pigs have but primates don’t, both to reduce the risk of rejection. They found that successful transplantation required blood to be pumped through the heart even when it was journeying from the pig’s chest to the baboon’s. Without that step, the first five baboons with pig hearts only survived for between a day and a month. In these animals, the left ventricle of the heart failed even after high doses of hormones were given to stimulate it. In the next group, of four animals, the team pumped a solution of glucose, hormones and red blood cells through the hearts from the time they were taken out of the pigs to their implantation in the baboons. One baboon was lost due to a technical failure, but the other three lived to 18, 27 and 40 days respectively. When the team examined the hearts after the animals had died, they found that the organs in the second group had more than doubled in weight. That may be because pigs reach adult weight faster than baboons. “The heart must grow to support a fast-growing body, and the genes are not switched off when you transplant into a baboon. The pig heart thinks it is still in the pig, and it doubles its size within a month,” says Reichart.
12-5-18 Baboons survive 6 months after getting a pig heart transplant
New transplant procedures bring scientists a step closer to using pig donors for human organs. For roughly six months, fully functioning pig hearts beat inside the chests of two Anubis baboons. Genetic modifications to the pig hearts along with a new transplant technique are credited with the longest-yet survival after such a transplant, researchers report December 5 in Nature. Previously, the longest a baboon lived after such a procedure was 57 days. Another two baboons in the study lived at least three months with pig hearts and were in good health during that time, says Bruno Reichart, a cardiac surgeon at Ludwig-Maximilians-Universität in Munich. The baboons hopped and climbed around their enclosures. Some enjoyed eating mangoes and eggs, and watching TV programs like “Tom and Jerry” and “Alvin and the Chipmunks,” he says. This work brings scientists closer to the goal of successfully transplanting life-supporting pig organs into humans, says Luhan Yang, chief scientific officer of eGenesis, a Boston company developing ways to transplant organs between different species in order to ease organ shortages (SN: 10/4/17, p. 26). “Of course, it’s still early, but we’re one step closer to the clinical application,” says Yang, who was not involved in the study. The pigs were engineered to produce a human version of two proteins — CD46, which blocks an immune response that pokes holes in foreign cells, and thrombomodulin, which prevents blood from clotting after surgery. Researchers also ensured that the pigs couldn’t make alpha-gal sugars, which coat the cells of all mammals except monkeys, apes and humans. Those sugars can provoke the immune system to attack organs transplanted from pigs into humans and other primates.
12-5-18 Why was HIV chosen as the first target for embryo gene editing?
WHEN presenting his work at the global gene-editing summit, He Jiankui noted the medical seriousness of HIV infection, saying he was proud of his efforts to use CRISPR to create infants that may be resistant to the virus. Is HIV so dangerous that it warrants such a drastic step? Certainly, the toll of HIV infection is high in some parts of the world. But advances in antiviral medicines over the past decade mean that people with HIV who have access to good healthcare now have a close-to-normal lifespan. The HIV-positive fathers who took part in the trial are reported to have had their virus under control, suggesting these men had access to such drugs. Gene editing doesn’t offer HIV-positive men their only chance to have unaffected children. Current treatments for HIV push the level of the virus down so low that a person’s partner or future offspring aren’t at risk of infection. Furthermore, the experiment used a “washing” technique to remove any HIV from the sperm before it was used for IVF, meaning that even without drug treatment, no virus could have made it into the embryos. If the aim was to protect the children from acquiring HIV as adults, a much simpler and safer medical intervention is already available to some: taking some of the antivirals used for treatment as a preventative. In certain Western cities, this “PrEP” strategy is contributing to tumbling rates of infection among gay men.
12-5-18 Gene editing is so easy to do that we couldn’t stop it if we wanted to
WE HUMANS have been shaping our own evolution for millions of years, through changes in the way we live, eat and reproduce. Until now, such adaptations have depended on the random nature of evolution, taking thousands of years. The CRISPR gene-editing method has the potential to change that, giving us the power to fully take the reins of our genetic destiny, and at speed. Last week, He Jiankui announced he had created the first gene-edited babies by using CRISPR to alter a gene in human embryos (see “The gene editing revelation that shocked the world”). This was shocking given most scientists believe making genetic changes that could be passed on to future generations is a line we aren’t ready to cross. Now that we have crossed this line so casually, it is clear that careful regulation of such technologies is required. But perhaps the greatest danger is that editing genes using CRISPR is so easy. Too much regulation may risk pushing experiments like He’s underground. He’s work is yet to be independently verified, but even if his report of gene-edited twins turns out not to be true, a second case of gene-edited babies probably isn’t far behind.
12-5-18 Genetic disorders should be the focus of CRISPR gene editing trials
He Jiankui tried to use CRISPR to make individuals immune to HIV, but many believe the most-compelling case for gene editing before birth is to prevent genetic disorders. Most disorders caused by mutations in a single gene, such as cystic fibrosis, can already be prevented. One way of doing this is to screen IVF embryos for harmful mutations before implanting them. However, such preimplantation genetic diagnosis has limitations, particularly when you only need to inherit the mutation from one parent to develop the condition, as is the case with Huntington’s, a neurological disorder. If one parent has this condition, half the embryos will carry the gene, halving a couple’s chances of successfully having children without the condition through IVF. Some mutations, including the cancer-causing BRCA1, can affect fertility, meaning women produce fewer eggs per IVF cycle, lowering their chances of success. Embryo screening is also of little use if the aim is to prevent children inheriting more than one harmful mutation, as the chances of finding a healthy embryo in such cases is much lower. In all these cases, using gene editing to repair mutations in embryos, rather than discarding them, would increase a couple’s chances of having children. Gene editing could also help men who can’t produce sperm due to mutations in the cells that make sperm. Correcting these mutations may restore their fertility – something that has been done in mice but isn’t yet possible in people. We all have thousands of harmful mutations that make us more prone to cancer, heart attacks or dementia. In principle, everyone could live longer, healthier lives if these were repaired, but we are still a long way from being able to achieve this.
12-5-18 Gene-editing experiment widely criticised for safety and ethics issues
The scientist who led an experiment to create gene-edited babies has been criticised for acting unethically towards the couples and infants involved. THE worldwide shock over the announcement of the birth of gene-edited twins isn’t just because it may be a scientific first. The scientist who led the work, He Jiankui, has also been widely criticised for acting unethically towards the couples and the babies involved in the trial. The biggest concern is that He used a technique that hasn’t had enough safety testing. One of the main known problems with the CRISPR technique is that it can cause unintended “off-target” mutations elsewhere in the DNA that may be harmful. This fear is particularly pertinent when it comes to editing whole embryos. Unlike gene-editing treatments for cancer, for example, which alter only some cells, using CRISPR on embryos has the potential to change the DNA in every cell in the body. This includes those that will go on to produce eggs or sperm. Such “germline” editing is ethically difficult, because these artificially induced mutations – and their unknown effects on health – may be passed on to the next generation, and ultimately become part of the human gene pool. The idea that harmful mutations could start accumulating in future generations is the biggest fear for most people about gene-editing embryos. He says the two babies don’t have off-target genetic changes. But many CRISPR experts think it is too soon to say. Even if the twins seem healthy, it is possible that an undetected, random genetic change could, for instance, make them prone to cancer in later life. (Webmaster's comment: The great fear is that the Chinese will be seen as leading the way.)
12-5-18 We’ve added letters to the genetic code – and the results are amazing
The first life forms with a six-letter genetic code are already pumping out drugs and other materials that nature has never seen before. MAKING a living thing is no mean feat, what with the billions of components that need putting together. Nature manages it with one molecule: deoxyribonucleic acid, better known as DNA. It is the instruction manual for building everything from songbirds to scorpions, seahorses to schoolchildren. Yet Steven Benner is unimpressed. “When you look at DNA, what you see is imperfection,” he says. He has a point. It may be a guide to making wondrous things, but DNA uses an alphabet of only four letters. What if we could sprinkle in a few extra ones? Do that, and the variety of materials that living cells could manufacture goes through the roof. We might even use that power to meet some of our most pressing needs, not least for new medicines. Benner and a few others have been chasing the dream of expanding the genetic alphabet for decades. Finally, one of them has succeeded in creating a life form that is not only founded on entirely novel genetic letters, but is also capable of using the instructions to assemble materials that incorporate wholly unnatural building blocks. This is life, but written with a whole new alphabet. The DNA double helix is a molecular icon. Its twin strands of genetic code, curled like a spiral staircase, has an elegance befitting the recipe of life. The sturdy rails of the staircase are made of the sugar deoxyribose and phosphate molecules. The steps are collections of atoms called bases. There are four types of base in DNA, each with slight chemical differences: adenine, thymine, cytosine and guanine, also known as A, T, C and G. These are the letters of the genetic code.
12-5-18 UK DNA project hits major milestone with 100,000 genomes sequenced
The UK’s 100,000 Genomes Project has hit its target of sequencing the complete genetic blueprints of 100,000 National Health Service patients with cancers and rare diseases. Data from the genomes is set to both benefit the 85,000 patients who contributed their DNA and to assist medical research. The project has now hit 100,249 genomes sequence – more than the number of patients because every participant with cancer has three genomes sequenced. Two are taken from healthy and cancerous cells within a tumour and the third is taken from blood. Currently the project is focusing on some 17 cancers, including both common and rare forms, and around 1200 rare diseases affecting children and adults. An estimated 4000 patients with rare diseases have been told about potentially important findings from the data set. Cancer patients have received more than 11,500 reports so far, half of which could be clinically useful. “We are leading the world in genomics and this is a major milestone in our mission to provide truly personalised care to help patients live longer, healthier and happier lives,” said UK health secretary Matt Hancock. “I’m incredibly excited about the potential of this type of technology to unlock the next generation of treatments, diagnose diseases earlier and enable patients to take greater control of their own health.” There are now plans to expand the 100,000 Genomes Project over the next five years with a new target of one million whole genomes, or even five million with the assistance of research and industry partners. (Webmaster's comment: Don't worry the United States will not be leading the world in this, Trump doesn't believe in Science!)
12-5-18 There won’t be many more gene-edited babies just yet – here’s why
THE first IVF baby, Louise Brown, was born in 1978. But before she was even born, more than 5000 couples had applied to undergo the procedure. Forty years on, around 8 million children have been conceived using IVF. Can we expect a similar opening of the floodgates for gene editing, following He Jiankui’s announcement of the birth of the first two babies to have been gene edited as embryos? Certainly not right away. Gene editing of embryos has the potential to affect many generations. Such “germline” genome editing is illegal in many countries. Just about every expert worldwide agrees that it is far too soon to use the CRISPR gene-editing technique used in this trial to create edited children. “The field is going to have a massive backlash,” says Gaetan Burgio of the Australian National University. The question is, just how bad will it be? Opinion falls into two camps. Some would like to see germline gene editing banned. But there are plenty of researchers who support the idea of using it to prevent disease when the safety of such techniques has been established. “Just because the first steps into a new technology are missteps, that doesn’t mean we shouldn’t step back and think of a plausible pathway for clinical translation,” George Daley of Harvard Medical School told last week’s gene-editing summit in Hong Kong. Those who have been campaigning against germline gene editing have responded to the scandal with a push for tougher regulation. Around 100 people, including some scientists, signed a letter calling on governments and the UN to ban all “reproductive experiments with human genetic engineering”.
12-5-18 Fossil preserves 'sea monster' blubber and skin
Scientists have identified fossilised blubber from an ancient marine reptile that lived 180 million years ago. Blubber is a thick layer of fat found under the skin of modern marine mammals such as whales. Its discovery in this ancient "sea monster" - an ichthyosaur - appears to confirm the animal was warm-blooded, a rarity in reptiles. The preserved skin is smooth, like that of whales or dolphins. It had lost the scales characteristic of its ancestors. The ichthyosaur's outer layer is still somewhat flexible and retains evidence of the animal's camouflage pattern. The reptile was counter-shaded - darker on the upper side and light on the underside. This counter-balances the shading effects of natural light, making the animal more difficult to see. "Ichthyosaurs are interesting because they have many traits in common with dolphins, but are not at all closely related to those sea-dwelling mammals," said co-author Mary Schweitzer, professor of biological sciences at North Carolina State University (NCSU). Their similar appearance suggests that ichthyosaurs and whales evolved similar strategies to adapt to marine life - an example of convergent evolution. Prof Schweitzer said: "They have many features in common with living marine reptiles like sea turtles, but we know from the fossil record that they gave live birth, which is associated with warm-bloodedness." Most reptiles today are cold-blooded, meaning their body temperature is determined by the warmth of their surroundings. Blubber helps some marine animals maintain a high body temperature regardless of the ocean water temperature.
12-5-18 Rats and pigeons 'replace iconic species'
The modification of land for farming and building cities is favouring the same species everywhere, according to a new study. Animals like rats and pigeons are taking over from less common ones, which can survive only in certain habitats, say scientists. Researchers looked at 20,000 animals and plants in 81 countries. They found that species occupying a large area tend to increase in places where humans use the land. However, fauna and flora that occupies a small area is lost. "We show around the world that when humans modify habitats, these unique species are consistently lost and are replaced by species that are found everywhere, such as pigeons in cities and rats in farmland," said Dr Tim Newbold, a research fellow at University College London. Rats, mice, sparrows and pigeons are examples of species with wide ranges that do well when natural habitats are replaced with farmland and cities, he said. However, the "narrow-ranged losers" include animals and plants which may have great cultural value, such as rhinos and tigers. Co-researcher, Prof Andy Purvis of the Natural History Museum, London, compared the changes in biodiversity to what is happening on the British high street."As small, independent retailers are going out of business, large chains dominate," he said. "It makes all towns look the same, and it's less easy to tell where you are. Likewise, people are affecting nature everywhere they go, and everywhere there are localised species which are struggling to make a living." (Webmaster's comment: A perfect example of evolution at work.)
12-5-18 Ash dieback: ash woodlands 'may flourish once again'
Scientists say there is hope that some ash forests will be able to survive a devastating tree disease. Surveys around Europe reveal mortality rates from ash dieback as high as 70% in woodlands and 85% in plantations. A previous study found almost all ash trees could be wiped out. The disease has swept across Europe over the past 20 years, causing widespread damage to woodlands. In many cases the fungus will eventually kill infected plants. "Although the numbers seem grim, the percentage of trees that are still alive is encouraging from a long-term perspective," said Prof Richard Buggs, of Royal Botanic Gardens Kew and Queen Mary University of London. "If this survival is due to heritable resistance, then conservation policies targeting breeding programs or natural selection may allow ash populations to flourish once again." The researchers pulled together surveys of ash dieback across Europe, including England, Ukraine, Scandinavia and the Baltic States. They found that even in forests that had been exposed to the disease for 20 years, not all trees were lost. "Although we may witness terrible devastation of ash woodlands in Europe, our grandchildren may see viable ash populations," said the researchers. There is typically a delay of 10 years from the disease entering the country to the widespread death of ash trees. This means that in the UK, the full extent of ash dieback will not become clear until 2022.
12-5-18 First baby born thanks to womb transplant from deceased donor
A woman has given birth to a healthy baby girl after surgeons implanted a uterus in her body taken from a dead person. The birth, in Brazil, is the first reported involving a deceased donor uterus transplant. Ten previous attempts, in the US, Czech Republic and Turkey, to achieve a live birth using a uterus taken from a dead individual had all ended in failure. The recipient in the latest case was a 32-year-old woman born without a uterus due to a rare genetic disorder. The uterus was taken from a 45-year-old donor who had died from a brain haemorrhage. Surgeons spent 10 and a half hours plumbing in the organ by connecting veins, arteries, ligaments and vaginal canals. After surgery, the anonymous recipient remained in intensive care for two days before spending another six days on a specialised transplant ward. She received five immunosuppression drugs to prevent her body rejecting the new organ, as well as other treatments to combat infection and blood clotting. Once the uterus was successfully incorporated into her body, she received fertilised eggs produced by IVF. A baby girl weighing 2.55 kilos was born by caesarean section after a pregnancy lasting 35 weeks and three days. During the delivery, the transplanted uterus was removed and showed no abnormalities. Dani Ejzenberg, at Sao Paulo University, Brazil, who led the team, said: “The use of deceased donors could greatly broaden access to this treatment, and our results provide proof-of-concept for a new option for women with uterine infertility.” (Webmaster's comment: The drive to breed knows no limits!)
12-5-18 First baby born after deceased womb transplant
A healthy baby girl has been born using a womb transplanted from a dead person. The 10-hour transplant operation - and later fertility treatment - took place in São Paulo, Brazil, in 2016. The mother, 32, was born without a womb. There have been 39 womb transplants using a live donor, including mothers donating their womb to their daughter, resulting in 11 babies. But the 10 previous transplants from a dead donor have failed or resulted in miscarriage. In this case, reported in The Lancet, the womb donor was a mother of three in her mid-40s who died from bleeding on the brain. The recipient had Mayer-Rokitansky-Küster-Hauser syndrome, which affects about one in every 4,500 women and results in the vagina and uterus (womb) failing to form properly. However, her ovaries were fine. And doctors were able to remove eggs, fertilise them with the father-to-be's sperm and freeze them. The woman was given drugs that weakened her immune system to prevent her body attacking and rejecting the transplant. And about six weeks later, she started having periods. After seven months, the fertilised eggs were implanted. And, after a normal pregnancy, a 6lb (2.5kg) baby was delivered by Caesarean section on 15 December 2017. Dr Dani Ejzenberg, from Hospital das Clínicas in São Paulo, said: "The first uterus transplants from live donors were a medical milestone, creating the possibility of childbirth for many infertile women with access to suitable donors and the needed medical facilities.
12-4-18 In a first, a woman with a uterus transplanted from a deceased donor gives birth
The healthy baby girl celebrates her first birthday this month. For the first time, a woman has given birth after receiving a uterus from a deceased donor. A reported 11 women have had babies after uterus transplants from living donors. But this breakthrough, described online December 4 in the Lancet, could boost the availability of viable organs for women who want to become pregnant but lack a womb. “Everyone was waiting to see whether [a deceased donor] would work with the same success” as a living donor, says abdominal transplant surgeon Giuliano Testa. Testa, who was not involved in this case, was a member of the team at Baylor University Medical Center at Dallas that reported earlier this year the first U.S. baby born, in 2017, after a living donor uterus transplant. The first such birth worldwide occurred in Sweden in 2014. An estimated 1.5 million women worldwide suffer from infertility because their uterus is missing — from a congenital condition, for example — or the organ is abnormal or damaged. In the deceased donor case, the recipient was born without a womb due to Mayer-Rokitansky-Küster-Hauser, or MRKH, syndrome, which affects 1 in 4,500 women. The donated uterus came from a 45-year-old woman who’d had three vaginal deliveries and died of a stroke. The recipient had the transplantation surgery in Brazil in September 2016, when she was 32 years old. She menstruated for the first time 37 days later. Seven months after the surgery, doctors transferred a single embryo — created via in vitro fertilization four months before the transplantation — to the uterus. During the pregnancy, blood flowed normally through the arteries in the uterus and the umbilical cord to the fetus, the medical team reports. Doctors removed the donated uterus after the delivery.
12-3-18 We have all we need to beat the HIV epidemic – except political will
The latest figures show that preventative efforts are working, if only governments are willing to put them into action, says Deborah Gold. Newly released HIV figures for Europe and Central Asia illuminate a story of two epidemics. The European Centre for Disease Prevention and Control and the WHO Regional Office for Europe report that new diagnoses over the past 10 years have increased by 68 per cent in Eastern Europe and 121 per cent in Central Europe. There have been more than 137,000 new diagnoses across both regions in just the past year. Meanwhile in Western Europe, there has been a 20 per cent decrease in the past two years, with around 25,000 new diagnoses last year. In 2014, UNAIDS set ambitious targets to help end the global HIV epidemic, known as 90-90-90. These were that by 2020, 90 per cent of all people living with HIV would know their status, 90 per cent of those diagnosed would be in treatment and 90 per cent of those on treatment would be virally supressed. Western Europe has, on average, reached two of these three goals and is close to reaching them all. Central and Eastern Europe have yet to reach any. More starkly than ever, the figures show just how well an effective HIV response can work, and the startling impact when it does not. Let us begin by looking at what works. Combination prevention is a package of measures that work together at a population level to turn the tide. Incontrovertible evidence now shows that a person on effective HIV treatment isn’t infectious and cannot pass the virus on. There has been an increase in frequent testing for HIV by those most vulnerable to infection, meaning that the time during which someone may unknowingly pass it on is greatly reduced. This is followed by swift access to HIV medication, which means better long-term outcomes for the individual, and also means those newly diagnosed quickly become uninfectious.
12-4-18 How some sap-sucking insects fling their pee
Sharpshooters can hurl their liquid waste at an acceleration up to 20 times Earth’s gravity. Some sap-sucking insects can “make it rain,” flinging droplets of pee while feeding on plant juices. Now scientists have explained how the insects, known as sharpshooters, create these sprays using tiny catapult-like structures that propel the waste at extreme accelerations. A tree infested with sharpshooters exudes a steady pitter-patter of pee. “It’s crazy just to look at,” says engineer Saad Bhamla of Georgia Tech in Atlanta. That intriguing process — which can dampen unsuspecting passersby — got Bhamla and colleagues hooked on studying how the insects release their waste. The researchers took high-speed video of two species — the glassy-winged sharpshooter and the blue-green sharpshooter — feeding and then flinging their pee. Those videos showed that a tiny barb called a stylus at the insect’s rear end acts like a spring. Once a drop collects on this structure, the “spring” releases, and the drop flies off as if hurled from a catapult. What’s more, tiny hairs at the end of the stylus increase its flinging power, Bhamla and colleagues suggest, much like the sling at the end of certain types of catapults. As a result, the stylus launches liquid waste with a maximum acceleration 20 times that of Earth’s gravity, the scientists report in a video published online in the American Physical Society’s Gallery of Fluid Motion, as part of the APS Division of Fluid Dynamics annual meeting held November 18–20 in Atlanta.
12-3-18 Dads, not just moms, can pass along mitochondrial DNA
In rare cases, kids can inherit the energy-producing organelles from fathers, a study finds. Some dads have broken a textbook genetic rule. Fathers in three unrelated families passed mitochondria — tiny energy factories found in cells — on to their children, researchers report. Scientists have long thought that children inherited mitochondria exclusively from their mothers, since mitochondria from the father’s sperm are usually destroyed after fertilizing the egg (SN: 1/1/00, p. 5). The new research, published online November 26 in the Proceedings of the National Academy of Sciences, suggests that in rare cases dads can contribute mitochondria too. For now, the consequences of inheriting mitochondria from both parents aren’t known. Mitochondrial disease researcher Paldeep Atwal spotted the paternal signature after examining DNA from a woman who came to the Mayo Clinic in Jacksonville, Fla. DNA in a cell’s nucleus is inherited equally from both parents and contains all the genetic instructions for building a body. Mitochondria have their own DNA, too, that contains some of the genes needed for building and running the organelles. The woman’s cells weirdly contained two types of mitochondrial DNA, some from mom and some “from elsewhere,” says Atwal, who now runs a private clinic in Jacksonville. Thinking the result was a mistake, Atwal and colleagues repeated the test. “The same thing came back the second time, and that’s when we started to get a little bit suspicious,” he says.